75 results on '"Zaman MB"'
Search Results
2. Accuracy of chest film screening by technologists in the New York early lung cancer detection program
- Author
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Flehinger, BJ, primary, Melamed, MR, additional, Heelan, RT, additional, McGinnis, CM, additional, Zaman, MB, additional, and Martini, N, additional
- Published
- 1978
- Full Text
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3. Lung cancer and exposure to tobacco smoke in the household.
- Author
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Janerich DT, Thompson WD, Varela LR, Greenwald P, Chorost S, Tucci C, Zaman MB, Melamed MR, Kiely M, and McKneally MF
- Published
- 1990
4. Rapid hydrothermal synthesis of mesoporous NiS 2 and NiSe 2 nanostructures for wastewater treatment.
- Author
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Lone MA, Shrotriya V, Lone TA, Alshahrani T, Hossain MA, Adam M, and Zaman MB
- Abstract
In the present study, single phase nickel based disulphide (NiS
2 ) and diselenide (NiSe2 ) nanostructures were prepared hydrothermally in a short time span (4 h) under subcritical temperature (160 °C). The nanostructures grow in cubic crystal phases. Average crystallite sizes and intrinsic microstrains were determined using Williamson-Hall (W-H) plot analysis. Hollow NiS2 nanospheres and bipyramidal NiSe2 nanostructures are reported that are suitable for surface related applications. Thermal gravimetric analysis (TGA) indicated high stability of the nanostructures at elevated temperatures. Optical studies indicated visible light activeness of the nanostructures exhibiting sharp band edges. The nanostructures are mesoporous in nature with NiS2 and NiSe2 having respectively a large specific surface area of 310 m2 /g and 177 m2 /g. A primarily work done to determine the electrochemical nature of the nanostructures showed the materials are pseudo-capacitive in nature with specific capacitances of 1022 F/g and 480 F/g respectively for NiS2 and NiSe2 . The photo-catalytic activity of the nanostructures was explored against a colourless pollutant; phenol. The nanostructures degraded most of the phenol (>90 %) under visible light illumination and the reusability experiments performed determined industrial value of the photocatalysts., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 Published by Elsevier Ltd.)- Published
- 2023
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5. Development of a calculated panel reactive antibody calculator for the United Arab Emirates: a proof of concept study.
- Author
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Alvares M, Anwar S, Hashmi SK, Zaman MB, Al Mahri A, Alvares C, Al Katheeri L, Purushothaman A, Ralonya ME, Sangalang MG, Jannang R, Abdulle A, Al Qubaisi A, Al Ahmed M, Khamis AH, Al Seiari M, Al Obaidli A, Al Yafei Z, and ElGhazali G
- Subjects
- Humans, Proof of Concept Study, United Arab Emirates, Canada, Antibodies, HLA Antigens, Histocompatibility Testing, Kidney Transplantation
- Abstract
Calculated panel reactive antibody (CPRA) is used to help increase sensitized patient's access to transplantation. United Arab Emirates (UAE) has a diverse resident population hence we developed a UAE-CPRA calculator based on HLA antigen frequencies of the different ethnic groups that represent the UAE population. HLA antigen frequencies at serological split antigen level for HLA-A, -B, -C, -DRB1 and -DQB1 of 1002 healthy unrelated donors were performed. We subsequently compared the performance of the UAE CPRA calculator with the Organ Procurement and Transplantation Network (OPTN) and the Canadian CPRA calculators in 110 Kidney Transplant waitlist patients from January 2016 to December 2018. Lin's concordance correlation coefficient showed a moderate agreement between the UAE and OPTN calculator (Rc = 0.949, 95% CI 0.929-0.963) and the UAE and Canadian calculators (Rc = 0.952, 95% CI 0.932-0.965). While there continued to be a moderate agreement (Rc = 0.937, UAE versus OPTN calculator) in the lower sensitized group, a poor agreement (Rc = 0.555, UAE versus OPTN calculator) was observed in the higher sensitized group. In this study, we provide a template for countries to develop their own population-specific CPRA calculator. Implementation of the CPRA algorithm based on HLA frequencies of the multi-ethnic UAE population will be more fitting to increase access to transplantation and improve transplant outcomes. Our study demonstrates that the CPRA calculators developed using the data from the western population had poor correlation in our higher sensitized patients disadvantaging them in potential organ allocations systems. We plan to further refine this calculator by using high resolution HLA typing to address the problem of a genetically diverse population., (© 2023. The Author(s).)
- Published
- 2023
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6. Clinical Findings and Radiological Evaluation of WHO-Defined Severe Pneumonia Among Hospitalized Children.
- Author
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Karim R, Afridi JK, Lala GE, Yar SR, Zaman MB, and Afridi BK
- Abstract
Background: The leading infectious cause of death in children worldwide is pneumonia. Pneumonia claimed the lives of 740,180 kids under the age of five in 2019, accounting for 14% of all fatalities and 22% of deaths in kids between the ages of 1 and 5. Children and families worldwide are affected by pneumonia, but South Asia and Africa have the highest fatality rates., Objective: This study aims to determine the clinical risk factors and radiological assessment of the World Health Organization (WHO)-defined severe pneumonia in Pakistani hospitalized children., Material and Methods: This cross-sectional study was carried out in the pediatric department of the Hayatabad Medical Complex between January 2021 and December 2021. The study included kids who had a fever, cough, and fast or difficulty breathing between the ages of 2 and 60 months. All of the included clinical pneumonia cases were acquired in the community., Results: A total of 360 clinically confirmed patients with pneumonia who presented with fever, cough, and fast or difficulty breathing were enrolled. Age ranged between 2 and 60 months, with a mean age of ±31 months. There were 168 (46.7%) males and 192 (53.3%) females. About 232 (64.4%) had radiological pneumonia, while the rest of the pneumonia cases 128 (35.5%) were without a radiological diagnosis. The most common presenting complaint was noisy breathing 119 (33%), followed by refusal of feeds 81 (22.5%), lethargy 69 (19.2%), seizure 40 (11.1%), nasal drainage 29 (8%), and abdominal pain 22 (6.1%)., Conclusion: The most specific clinical finding of radiographic pneumonia was bronchial breathing, while tachypnea was the most sensitive sign., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Karim et al.)
- Published
- 2023
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7. Change of Hemoglobin Level among Exclusively Breastfed Term and Preterm Babies up to Six Months of Age.
- Author
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Parvin S, Nasrin KN, Hossain MA, Islam MN, Khan M, Taher MA, Farzana MN, Islam N, Alam MK, Naher A, Amin SE, Zaman MB, Amin S, Begum B, Khan MI, and Ferdousi J
- Subjects
- Feeding Behavior, Female, Hemoglobins analysis, Humans, Infant, Infant, Newborn, Intensive Care Units, Neonatal, Male, Breast Feeding, Infant, Premature
- Abstract
There is progressive increase of Hb levels is observed during course of intrauterine development of fetus but high concentrations found at birth. In preterm neonate normal Hb is characteristically deviated from term neonate. Breast milk is the only natural ideal food for both term and preterm babies from birth up to 6 months. Preterm milk was found to contain significantly higher concentrations nutrients particularly iron than term milk. Preterm human milk is more suitable for the premature infant than term human milk. As Hb concentration varies in term and preterm babies in different counties in different feeding practices. The purpose of this longitudinal descriptive study is to find out the pattern of changes in the Hb level among exclusively breastfed preterm and term infants during the first six months of life. This study was carried in the Neonatal Intensive Care Unit (NICU), Mymensingh Medical College Hospital (MMCH), Mymensingh from September 2016 to February 2018. One hundred fifty (150) neonates both term and preterm were included in this study and followed up to 6 months of age. After admission informed written consent was taken from parents, thorough history taking and clinical examination were done. Data were collected in a pre-designed case record form. All the babies of Group A provided 2mg/kg iron supplementation from 6 weeks for 2 months for universal recommendation. Hb level was measured of all exclusively breast feed babies at admission after birth then next follow-up at 6 weeks, 3 months and 6 months. All information regarding history, anthropometrics measurement, Hb level was recorded in structural questionnaire. Data analysis was done by SPSS version 20.0. Male were predominant in both groups. Most of the preterm (72.0%) and term babies (65.3%) were delivered by vaginal route. Mean Hb level was found significantly higher among preterm babies than term babies after birth were 16.55g/dl and 15.98g/dl respectively. Sharp fall of Hb concentration was observed after birth up to 6 weeks in both preterm and term babies but Hb level was found significantly lower in preterm in comparison to term babies (9.27gm/dl vs. 9.58gm/dl). In term babies, even after 6 weeks fall of Hb level continued to 3 months of age followed by gradual increase up to 6 months without iron supplementation. Hb level of in preterm babies gradually increased from 6 weeks up to 6 months with universal iron supplementation. Hb level fall sharply up to 6 weeks in both exclusively breastfed term and preterm babies but even after 6 weeks term babies experienced gradual fall of Hb levels up to 3 months. Hb level increases in exclusively breast-fed term babies without iron supplementation from 3 months of age. Hb level in exclusively breastfed preterm babies increase from 6 weeks onward might be effect of universal iron supplementation.
- Published
- 2022
8. Facile Way of Making Hydrothermally Synthesized Crystalline SrSnO 3 Perovskite Nanorods Suitable for Blue LEDs and Spintronic Applications.
- Author
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Bhat AA, Zaman MB, Malik JH, Malik KA, Assadullah I, and Tomar R
- Abstract
Mn doping in SrSnO
3 perovskite material via hydrothermal process under subcritical conditions is reported for the very first time. The present article aims to carry this perovskite suitable for blue light-emitting diodes (LEDs) and spintronic applications. The influence of various Mn doping percentages on structural, morphological, compositional, optical, photoluminescent, and magnetic properties of SrSnO3 is demonstrated. The perovskite material is grown in an orthorhombic crystal structure having a space symmetry of Pnma along with point group of mmm as determined from the Rietveld refinement. Doping is an excellent way to modify the properties of wide-band-gap perovskite nanostructures. Incorporation of Mn is the result of exact substitution. Morphological studies indicate formation of rodlike structures with thickness in nanoscale dimensions (180-280 nm), and the thickness is a function of doping concentration. The higher doping concentration resulted in enhanced growth of the nanorods. Selected area electron diffraction (SAED) results showed the single-crystal nature of the nanorods. Thermogravimetric analysis (TGA) confirmed the high stability of the material at elevated temperatures. Also, the doped perovskite material is transparent in the visible light, active in the ultraviolet region having a band gap of ∼2.78 eV, and is tuned up to 2.25 eV as the Mn doping concentration reaches 10%. The transfer of excitonic energy from the host material to the dopant Mn2+ ion leads to the formation of spin-forbidden [4 T1 -6 A1 ] emission. Later on, photoluminescence study indicates an enhancement in luminescence behavior of Mn doped perovskite nanostructures. The Commission Internationale de l'éclairage (CIE) diagram drawn to find the color coordinates of the nanorods determines their suitability for blue LEDs. In addition, Mn doping results the conversion of diamagnetic SrSnO3 into a ferromagnetic material, making the nanorods suitable for spintronic applications., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)- Published
- 2021
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9. Thioglycolic acid assisted hydrothermal growth of SnS 2D nanosheets as catalysts for photodegradation of industrial dyes.
- Author
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Zaman MB, Poolla R, Khandy SA, Modi A, and Tiwari RK
- Abstract
We present our work on the rapid hydrothermal synthesis of highly crystalline 2D SnS nanostructures. An innovative idea is used in which thioglycolic acid is the sulfur precursor source. Structural studies indicate the material has grown in a single-phase orthorhombic structure. The single-phase formation of the material is also confirmed from the rietveld refinement of the experimental XRD data and by raman spectroscopic analysis. Morphological studies show the formation of 2D sheets having thickness in the nanoscale (100-150 nm) dimensions. Optical absorbance studies show the material is visible-light active exhibiting an indirect bandgap of 1.1 eV and direct band gap ∼1.7 eV. Density functional theory calculations support the experimental bandgap results. Photocatalytic activity of the nanosheets was investigated against methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) dyes employing a solar simulator as the source of photons (light source). The nanosheets were found to photodegrade 80% of MB, 77% of RhB and 60% of MO in 120 min of light illumination. Reusability and post catalytic properties affirm the durability and stability of the nanosheets, which is very important in the context of waste water treatment considering the toxic nature of the effluents from dye industries., (© 2021 IOP Publishing Ltd.)
- Published
- 2021
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10. Growth and properties of hydrothermally derived crystalline ZnSe quantum dots.
- Author
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Assadullah I, Zaman MB, Malik KA, Malik JH, Bhat AA, and Tomar R
- Subjects
- Water, X-Ray Diffraction, Zinc Compounds, Quantum Dots, Selenium Compounds
- Abstract
Chalcogenide nanostructures are the materials with diverse applications. Here, we report rapid hydrothermal synthesis of crystalline ZnSe quantum dots (QDs), avoiding the use of toxic chemicals. To the best of our knowledge, this is the first report on very rapid (5 h) hydrothermal synthesis of pristine ZnSe QDs. Elemental selenium is used as a source for selenium. Structural, morphological, compositional, and optical properties of the semiconductor were studied. Structural properties (X-ray diffraction) demonstrate that the particles have grown in a single cubic phase. Morphological studies show formation of agglomerated QDs (4 nm). The material possess stoichiometric ratio of the constituent elements that are uniformly distributed. Selected area electron diffraction (SAED) study indicated the material is polycrystalline in nature. Optical properties demonstrated that the QDs are suitable for optoelectronic devices exhibiting room temperature photoluminescence. Commission Internationale de l'Éclairage (CIE) chromaticity diagram shows the material exhibits violet emission and hence suitable for violet LEDs that have potential ability in clinical applications.
- Published
- 2021
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11. Facile and efficient 3-chlorophenol sensor development based on photolumenescent core-shell CdSe/ZnS quantum dots.
- Author
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Rahman MM, Karim MR, Alam MM, Zaman MB, Alharthi N, Alharbi H, and Asiri AM
- Abstract
Quantum dots (QDs) are semiconducting inorganic nanoparticles, tiny molecules of 2-10 nm sizes to strength the quantum confinements of electrons. The QDs are good enough to emit light onto electrons for exciting and returning to the ground state. Here, CdSe/ZnS core/shell QDs have been prepared and applied for electrochemical sensor development in this approach. Flat glassy carbon electrode (GCE) was coated with CdSe/ZnS QDs as very thin uniform layer to result of the selective and efficient sensor of 3-CP (3-chlorophenol). The significant analytical parameters were calculated from the calibration plot such as sensitivity (3.6392 µA µM
-1 cm-2 ) and detection limit (26.09 ± 1.30 pM) with CdSe/ZnS/GCE sensor probe by electrochemical approach. The calibration curve was fitted with the regression co-efficient r2 = 0.9906 in the range of 0.1 nM ∼ 0.1 mM concentration, which denoted as linear dynamic range (LDR). Besides these, it was performed the reproducibility in short response time and successfully validated the fabricated sensor for 3-CP in the real environmental and extracted samples. It is introduced as a noble route to detect the environmental phenolic contaminants using CdSe/ZnS QDs modified sensor by electrochemical method for the safety of healthcare and environmental fields at broad scales.- Published
- 2020
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12. TB Meningitis and TB Peritonitis: Abdominal Pseudocyst and VP-Shunt Link.
- Author
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Ahmed M, ElGamal EA, Ahmad A, and Zaman MB
- Abstract
TB meningitis (TBM) carries high morbidity and mortality and is a relatively common extrapulmonary TB in the third world countries. TBM as thick exudative disease manifests on MRI and CT as nodular basal leptomeningitis, hydrocephalus, basal infarcts, and tuberculomas. Hydrocephalus is treated with ventriculoperitoneal shunting (VPS). Shunt malfunction and revision are common. We report a case of multidrug-resistant TBM with spinal involvement and dissemination of the disease via VPS causing TB peritonitis (TBP). TBP presented as a large abdominal pseudocyst around the catheter tip with shunt malfunction. There was no evidence for any other site of extra-CNS disease. TBP per se is relatively less common. This is the first case reporting VPS as a means of TB spread.
- Published
- 2019
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13. Laser from Optically Pumped Quantum Dot CdSe/ZnS in a Colloidal Liquid.
- Author
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Prasad S, Ibnaouf KH, AlSalhi MS, Alameh K, Devaraj D, Hamdan A, Karim MR, Zaman MB, and Masilamani V
- Abstract
In this study, we had investigated the amplified spontaneous emission (ASE) characteristics of CdSe/ZnS quantum dot (QDs) in a colloidal liquid. A third harmonic of Nd:YAG laser (355 nm) was used to produce laser-induced fluorescence (LIF) at 605 nm with a spectral width of 0 nm [full width at half maximum (FWHM)]. When the pump power and focusing were carefully optimized, an ASE at 610 nm with a spectral width of Δλ = 8 nm (FWHM) could be obtained. The beam was directional with a divergence of 10 milli radians (mrad); but the conversion efficiency was about 0.05%.
- Published
- 2015
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14. Photoluminescence spectra of CdSe/ZnS quantum dots in solution.
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Ibnaouf KH, Prasad S, Hamdan A, Alsalhi M, Aldwayyan AS, Zaman MB, and Masilamani V
- Subjects
- Absorption, Benzene chemistry, Solutions, Solvents chemistry, Spectrum Analysis, Cadmium Compounds chemistry, Luminescence, Quantum Dots chemistry, Selenium Compounds chemistry, Sulfides chemistry, Zinc Compounds chemistry
- Abstract
The spectral properties of CdSe/ZnS core-shell quantum dots (QDs) of 3 nm size have been studied under different organic solvents, concentrations and temperatures. Our results showed that the absorption spectra of CdSe/ZnS in benzene have two humps; one around 420 nm and another at 525 nm, with a steady increase in absorption along UV region, and the absorption spectral profile under a wide range of concentrations did not change. On the other hand, the photoluminescence (PL) spectra of CdSe/ZnS in benzene showed two bands one around 375 nm and the other around 550 nm. It could be seen that the band at 375 nm is due to the interaction between the shell (ZnS) with the solvent species in high excited state, and the band at 550 nm is due to core alone (CdSe)., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2014
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15. Low-temperature approach to highly emissive copper indium sulfide colloidal nanocrystals and their bioimaging applications.
- Author
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Yu K, Ng P, Ouyang J, Zaman MB, Abulrob A, Baral TN, Fatehi D, Jakubek ZJ, Kingston D, Wu X, Liu X, Hebert C, Leek DM, and Whitfield DM
- Subjects
- Animals, Cell Line, Tumor, Cold Temperature, Colloids chemistry, Humans, Male, Mice, Mice, Nude, Molecular Imaging methods, Copper chemistry, Glioblastoma chemistry, Indium chemistry, Molecular Imaging instrumentation, Nanoparticles chemistry, Sulfides chemistry
- Abstract
We report our newly developed low-temperature synthesis of colloidal photoluminescent (PL) CuInS2 nanocrystals (NCs) and their in vitro and in vivo imaging applications. With diphenylphosphine sulphide (SDPP) as a S precursor made from elemental S and diphenylphosphine, this is a noninjection based approach in 1-dodecanethiol (DDT) with excellent synthetic reproducibility and large-scale capability. For a typical synthesis with copper iodide (CuI) as a Cu source and indium acetate (In(OAc)3) as an In source, the growth temperature was as low as 160 °C and the feed molar ratios were 1Cu-to-1In-to-4S. Amazingly, the resulting CuInS2 NCs in toluene exhibit quantum yield (QY) of ~23% with photoemission peaking at ~760 nm and full width at half maximum (FWHM) of ~140 nm. With a mean size of ~3.4 nm (measured from the vertices to the bases of the pyramids), they are pyramidal in shape with a crystal structure of tetragonal chalcopyrite. In situ (31)P NMR (monitored from 30 °C to 100 °C) and in situ absorption at 80 °C suggested that the Cu precursor should be less reactive toward SDPP than the In precursor. For our in vitro and in vivo imaging applications, CuInS2/ZnS core-shell QDs were synthesized; afterwards, dihydrolipoic acid (DHLA) or 11-mercaptoundecanoic acid (MUA) were used for ligand exchange and then bio-conjugation was performed. Two single-domain antibodies (sdAbs) were used. One was 2A3 for in vitro imaging of BxPC3 pancreatic cancer cells. The other was EG2 for in vivo imaging of a Glioblastoma U87MG brain tumour model. The bioimaging data illustrate that the CuInS2 NCs from our SDPP-based low-temperature noninjection approach are good quality.
- Published
- 2013
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16. Size reduction of CdSe/ZnS quantum dots by a peptidic amyloid supergelator.
- Author
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Zaman MB, Bardelang D, Prakesch M, Leek DM, Naubron JV, Chan G, Wu X, Ripmeester JA, Ratcliffe CI, and Yu K
- Subjects
- Circular Dichroism, Ligands, Magnetic Resonance Spectroscopy, Microscopy, Electron, Transmission, Spectrophotometry, Infrared, Spectrum Analysis, Temperature, Time Factors, Toluene chemistry, Amyloid chemistry, Cadmium Compounds chemistry, Gels chemistry, Particle Size, Peptides chemistry, Quantum Dots, Selenium Compounds chemistry, Sulfides chemistry, Zinc Compounds chemistry
- Abstract
Anchoring of a self-assembling dipeptide on the surface of core/shell CdSe/ZnS quantum dots resulted in a competition between coordination of the surface atoms of the QDs and the strong tendency for the dipeptide to self-assemble in toluene. This resulted in a mild QD etching and in a corresponding increase in the band gap of the nanocrystals whose photoluminescent emission gradually turns blue with time. The FmocLeuLeuOH dipeptide supergelator self-assembles in fibrils in which the Fmoc groups are surrounded by the pendant isobutyl side chains of the leucine residues with vibrational circular dichroism (VCD) and liquid- and solid-state NMR attributes of twist anti-parallel β-sheets., (© 2012 American Chemical Society)
- Published
- 2012
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17. C-Methyl-calix[4]resorcinarene-1,4-bis-(pyridin-3-yl)-2,3-diaza-1,3-butadiene (1/2).
- Author
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Udachin KA, Zaman MB, and Ripmeester JA
- Abstract
In the title compound, 2C(12)H(10)N(4)·C(32)H(32)O(8), the calixarene adopts a rctt conformation with dihedral angles of 138.40 (1) and 9.10 (1)° between the opposite rings. The dihedral angles between the rings of the pyridine derivative are 8.80 (1) and 9.20 (1)°. In the crystal, adjacent C-methylcalix[4]resorcinarene molecules are connected into columns parallel to [010] by O-H⋯O hydrogen bonds. O-H⋯N hydrogen bonds between the axial phenoxyl groups and bipyridine molecules link the columns into sheets parallel to (011), which are connected by O-H⋯N hydrogen bonds. Further O-H⋯N hydrogen bonds link the bipyridine and C-methylcalix[4]resorcinarene molecules, giving rise to a three-dimensional network.
- Published
- 2012
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18. Bis(guanidinium) chloranilate.
- Author
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Udachin KA, Zaman MB, and Ripmeester JA
- Abstract
The asymmetric unit of the title co-crystal, 2CH(6)N(3) (+)·C(6)Cl(2)O(4) (2-), contains one half of a chloranilate anion and one guanidinium cation, which are connected by strong N-H⋯O hydrogen bonds into a two-dimensional network.
- Published
- 2011
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19. Single-domain antibody bioconjugated near-IR quantum dots for targeted cellular imaging of pancreatic cancer.
- Author
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Zaman MB, Baral TN, Jakubek ZJ, Zhang J, Wu X, Lai E, Whitfield D, and Yu K
- Subjects
- Antigens, CD immunology, Cell Adhesion Molecules immunology, Cell Line, Tumor, GPI-Linked Proteins immunology, Humans, Microscopy, Fluorescence, Immunoconjugates, Pancreatic Neoplasms pathology, Quantum Dots, Spectroscopy, Near-Infrared methods
- Abstract
Successful targeted imaging of BxPC3 human pancreatic cancer cells is feasible with near-IR CdTeSe/CdS quantum dots (QDs) functionalized with single-domain antibody (sdAb) 2A3. For specific targeting, sdAbs are superior to conventional antibodies, especially in terms of stability, aggregation, and production cost. The bright CdTeSe/CdS QDs were synthesized to emit in the diagnostic window of 650-900 nm with a narrow emission band. 2A3 was derived from llama and is small in size of 13 kDa, but with fully-functional recognition to the target carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), a possible biomarker as a therapeutic target of pancreatic cancer. For compelling imaging, optical may be the most sensible among the various imaging modalities, regarding the sensitivity and cost. This first report on sdAb-conjugated near-IR QDs with high signal to background sensitivity for targeted cellular imaging brings insights into the development of optical molecular imaging for early stage cancer diagnosis.
- Published
- 2011
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20. Optical response of CdSe quantum dots to cesium-137 gamma-ray radiation.
- Author
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Yu K, Cui Y, Li C, Zaman MB, Wilkins R, Wu X, and Ouyang J
- Abstract
The optical response of colloidal photoluminescent (PL) semiconductor nanocrystals to 137Cs gamma radiation was investigated. The quantum dots (QDs) used were CdSe dispersed in hexane, exhibiting bandgap absorption and emission peaking at 556 nm and 563 nm, respectively. The doses of the 137Cs gamma radiations were 0.1, 1.0, 10 and 100 Gy with a dose rate of 0.805 Gy/min. Each radiation was performed on two identical samples; right after the radiation, absorption and emission measurements were performed. The change of the optical properties after the radiation was presented together with those of a control sample without radiation exposure. The prompt absorption measurements showed that there is little change with the 0.1 Gy up to 100 Gy radiations, while the prompt emission measurements showed that with the 0.1 Gy and 1 Gy radiation, there is a negligible change in the PL intensity; with the 10 Gy and 100 Gy radiation, there is a noticeable decrease in the PL intensity. Therefore, it seems that the radiation does not destroy the QDs themselves but leads to some loss of their surface passivation. Furthermore, the optical properties of the eight irradiated samples and the control sample were monitored periodically up to days. Interestingly, after the storage of days in dark, there is significant recovery in the PL intensity of the large-dose irradiated samples; such a rebound tendency provides the potential for the colloidal QDs to be novel and promising candidates in radiation dosimeter with multi-detection capability.
- Published
- 2010
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21. Premalignant and malignant cells in sputum from lung cancer patients.
- Author
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Neumann T, Meyer M, Patten FW, Johnson FL, Erozan YS, Frable WJ, Gupta PK, Zaman MB, and Nelson AC
- Subjects
- Adult, Female, Humans, Lung Neoplasms pathology, Male, Cytodiagnosis methods, Lung Neoplasms diagnosis, Precancerous Conditions diagnosis, Sputum cytology
- Abstract
Background: The objective of this study was to assess the frequency of premalignant and malignant cells in sputum from patients with lung cancer and to measure the dependence of these cells on cancer stage, histologic type, tumor size, and tumor location., Methods: This analysis included 444 patients with lung cancer. First, all patients were asked to produce sputum spontaneously; then, they underwent sputum induction. Slide preparations of the sputa were screened for the presence of abnormal cells., Results: Of all patients with lung cancer who had produced adequate specimens, 74.6% had sputum that was positive for premalignant or worse cells, whereas 48.7% had sputum that was positive for malignant cells alone. Surprisingly, the presence of premalignant or worse cells in sputum depended only moderately on disease stage (82.9% of stage IV cancers vs 65.9% of stage I cancers), tumor size (78.6% of tumors >2 cm vs 64.7% of tumors
- Published
- 2009
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22. Hepatic transplantation outcomes for carefully selected cirrhotic patients with hepatocellular carcinoma: experience at a small- to medium-volume centre.
- Author
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Qasim A, Zaman MB, Maguire D, Geoghegan J, Gibney R, Nolan N, Traynor O, Hegarty J, and McCormick PA
- Subjects
- Adult, Aged, Carcinoma, Hepatocellular complications, Carcinoma, Hepatocellular pathology, Humans, Liver Cirrhosis complications, Liver Cirrhosis pathology, Liver Neoplasms complications, Liver Neoplasms pathology, Middle Aged, Treatment Outcome, Carcinoma, Hepatocellular surgery, Liver Cirrhosis surgery, Liver Neoplasms surgery, Liver Transplantation
- Abstract
Background: Hepatic transplantation outcomes for cirrhotic patients with hepatocellular carcinoma (HCC) at a small- to medium-volume centre are not fully known due to relative novelty of patient selection criteria., Aim: To determine hepatic transplantation outcomes for HCC at a small- to medium-volume centre. Patients and methods Hepatocellular carcinoma patients were listed for transplantation according to the International Guideline and further categorized as those fulfilling or exceeding Milan or University of San Francisco (UCSF) criteria on explanted liver morphology. Outcomes including mortality, retransplantation, and tumour recurrence rate were analysed., Results: Twenty-six patients had HCC and on explanted liver morphology, Milan and UCSF criteria met 15 and 18 patients, respectively. Patients and graft survival at 3 months, 1 and 5 years were 100, 96, 84, and 88, 84, 77%, respectively. Outcomes favoured Milan criteria but did not reach statistical significance., Conclusions: Hepatic transplantation for HCC at a small-to medium-volume transplant centre had comparable survival outcomes to high-volume centres.
- Published
- 2009
- Full Text
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23. Photoluminescent quantum dot?cucurbituril nanocomposites.
- Author
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Li M, Zaman MB, Bardelang D, Wu X, Wang D, Margeson JC, Leek DM, Ripmeester JA, Ratcliffe CI, Lin Q, Yang B, and Yu K
- Abstract
The preparation of entrapped CdSe?ZnS fluorescent quantum dots (QDs) in cucurbituril (CB) polymer capsules is reported.
- Published
- 2009
- Full Text
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24. Outcome of liver transplantation in hereditary hemochromatosis.
- Author
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Dar FS, Faraj W, Zaman MB, Bartlett A, Bomford A, O'Sullivan A, O'Grady J, Heneghan M, Rela M, and Heaton ND
- Subjects
- Adult, Aged, Carcinoma, Hepatocellular therapy, Female, Fibrosis therapy, Graft Survival, Hemochromatosis genetics, Humans, Immunosuppressive Agents therapeutic use, Iron Overload, Liver Neoplasms therapy, Male, Middle Aged, Recurrence, Treatment Outcome, Hemochromatosis therapy, Liver Transplantation methods
- Abstract
Hereditary hemochromatosis (HH) is a genetic disorder of iron metabolism. It is an uncommon indication for liver transplantation (LT). It has been suggested that patients who undergo LT for cirrhosis related to HH have higher morbidity and mortality from cardiac, infectious and malignant complications. The purpose of this retrospective review was to determine whether these observations hold true in the current era. We analysed the data of 22 patients who had LT for HH from 1996 to 2007 at our center. Thirteen patients had LT for complications of end-stage liver disease, seven for hepatocellular carcinoma (HCC) and two for subacute liver failure. Cofactors promoting liver disease were identified in 15 patients. Ten patients had iron reduction with venesection before transplantation. Patient and graft survival at 1 and 5 years were 80.7%, and 74% respectively. There were seven deaths after a median follow up of 46 months either because of multiorgan failure, or caused by HCC recurrence. Bacterial infections were the commonest cause of morbidity. Patients with HH remain at a higher risk of developing HCC. Infectious complications are common. Iron reduction with preoperative venesection reduces the risk of cardiac and infection complications postoperatively. Improved survival post-LT reflects changes in selection, disease modification through venesection, and improvement in immunosuppression.
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- 2009
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25. Current indications for combined liver and kidney transplantation in adults.
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Chava SP, Singh B, Zaman MB, Rela M, and Heaton ND
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- Adult, Humans, Kidney Transplantation statistics & numerical data, Liver Transplantation statistics & numerical data, Kidney Transplantation methods, Kidney Transplantation trends, Liver Transplantation methods, Liver Transplantation trends
- Abstract
Unlabelled: A significant number of patients awaiting liver transplantation have associated renal failure. Combined Liver and Kidney Transplantation (CLKT) is increasingly offered especially since the introduction of Model for End-Stage Liver Disease (MELD). Decision to perform CLKT is straightforward when both organs suffer end-stage failure. However, the indications for CLKT are not well defined and there is controversy concerning some. We reviewed available data on PUBMED, United Network for Organ Sharing (UNOS), Organ Procurement Transplantation Network (OPTN), European Society for Organ Transplantation (ESOT) and discuss all current indications for CLKT., Conclusion: Overall long-term outcome following CLKT is acceptable. There is an urgent need to further refine our ability to identify the cases with reversible renal injury in the setting of end-stage liver disease to avoid unnecessary CLKT. Liver protects the kidney from disease recurrence and allograft loss in metabolic diseases. However, the use of liver allograft for immunological protection of kidneys in highly sensitised patients with positive cross-match and previously failed renal transplants is still experimental.
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- 2009
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26. Single-sized colloidal CdTe nanocrystals with strong bandgap photoluminescence.
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Wang R, Ouyang J, Nikolaus S, Brestaz L, Zaman MB, Wu X, Leek D, Ratcliffe CI, and Yu K
- Abstract
One brand-new colloidal ensemble of single-sized CdTe nanocrystals, exhibiting a sharp first excitonic absorption peak at 427 nm and bright bandgap photoluminescence at 427 nm with narrow full width at half maximum (FWHM) of only ca. 10 nm, was synthesized in 1-octadecene (ODE) via a non-injection one-pot approach which features high synthetic reproducibility with potential for industrial scale production.
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- 2009
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27. Unusual sculpting of dipeptide particles by ultrasound induces gelation.
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Bardelang D, Camerel F, Margeson JC, Leek DM, Schmutz M, Zaman MB, Yu K, Soldatov DV, Ziessel R, Ratcliffe CI, and Ripmeester JA
- Subjects
- Gels chemistry, Molecular Conformation, Particle Size, Solvents chemistry, Temperature, Dipeptides chemistry, Gels chemical synthesis, Ultrasonics
- Published
- 2008
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28. Neoadjuvant chemotherapy with gemcitabine-containing regimens in patients with early-stage non-small cell lung cancer.
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Detterbeck FC, Socinski MA, Gralla RJ, Edelman MJ, Jahan TM, Loesch DM, Limentani SA, Govindan R, Zaman MB, Ye Z, Monberg MJ, and Obasaju CK
- Subjects
- Adenocarcinoma diagnosis, Adenocarcinoma pathology, Adult, Aged, Aged, 80 and over, Carboplatin administration & dosage, Carcinoma, Large Cell diagnosis, Carcinoma, Large Cell pathology, Carcinoma, Non-Small-Cell Lung mortality, Carcinoma, Non-Small-Cell Lung pathology, Carcinoma, Non-Small-Cell Lung surgery, Carcinoma, Squamous Cell diagnosis, Carcinoma, Squamous Cell pathology, Cisplatin administration & dosage, Deoxycytidine administration & dosage, Drug Administration Schedule, Feasibility Studies, Female, Follow-Up Studies, Humans, Lung Neoplasms mortality, Lung Neoplasms pathology, Lung Neoplasms surgery, Male, Middle Aged, Neoadjuvant Therapy, Neoplasm Staging, Paclitaxel administration & dosage, Survival Analysis, Time Factors, Treatment Outcome, Gemcitabine, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Carcinoma, Non-Small-Cell Lung drug therapy, Deoxycytidine analogs & derivatives, Lung Neoplasms drug therapy
- Abstract
Background: Surgical resection alone remains suboptimal for patients with early-stage (I or II) non-small cell lung cancer. Two similar randomized phase II trials were conducted to define an active preoperative regimen in this disease state., Methods: In the first study, patients were randomized to receive gemcitabine 1000 mg/m2 on days 1 and 8 plus cisplatin 80 mg/m2 on day 1 (GC) or gemcitabine 1000 mg/m2 on days 1 and 8 plus carboplatin area under the curve 5.5 on day 1 (GCb). In the second trial, patients received the same regimen of GCb or gemcitabine 1000 mg/m2 on days 1 and 8 plus paclitaxel 200 mg/m2 on day 1 (GP). Cycles were repeated every 21 days for three cycles. The primary end point was pathologic complete response (pCR) rate., Results: Eighty-seven eligible patients were randomized (GC n = 12, GP n = 35, and GCb n = 40), and 71 (82%) underwent surgery after chemotherapy. The confirmed pCR rate was 2.3% (2 of 87, 95% confidence interval 0.3-8.1). Clinical response rate was 28.7%, complete resection rate was 91.5% (65 of 71 patients), and perioperative mortality rate was 2.8%. As of October 2006, median survival for all patients was 45 months (65.5% censored), with 87.2% alive at 1 year and 69.8% alive at 2 years., Discussion: Neoadjuvant chemotherapy with gemcitabine was feasible and well tolerated, and outcomes were similar to other reports of this treatment strategy. However, no regimen achieved the predefined pCR rate that would be sufficient to warrant further evaluation in the phase III setting. This trial design provides an efficient way of providing a rationale for choosing or rejecting regimens of potential value.
- Published
- 2008
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29. Lower expression of Nrf2 mRNA in older donor livers: a possible contributor to increased ischemia-reperfusion injury?
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Zaman MB, Leonard MO, Ryan EJ, Nolan NP, Hoti E, Maguire D, Mulcahy H, Traynor O, Taylor CT, Hegarty JE, Geoghegan JG, and O'Farrelly C
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- Adolescent, Adult, Aged, Biopsy, Cadaver, Cause of Death, Humans, Liver growth & development, Liver pathology, Middle Aged, Polymerase Chain Reaction, Liver physiology, NF-E2-Related Factor 2 genetics, RNA, Messenger genetics, Reperfusion Injury epidemiology, Tissue Donors
- Abstract
Background: The cellular mechanisms involved in mediating cytoprotection against ischemia-reperfusion (IR) injury are not well understood. In animal models, NF-E2-related factor-2 (Nrf2) protects against IR injury by transcriptional activation of phase II antioxidants. Here, we investigate how the expression of Nrf2 mRNA in human donor livers in the setting of liver transplantation (LT) correlates with the histological damage associated with IR injury and whether or not this influences the outcome of LT., Methods: Pairs of biopsies were acquired from 14 donor livers; the first biopsy of each pair was taken at the start of the retrieval operation, prior to the IR phase of LT and the second at the end of transplantation. RNA was extracted from snap frozen tissue and cDNA was prepared. Nrf2 mRNA expression was determined using real-time polymerase chain reaction (PCR). The modified Suzuki scoring system was used for histological grading of IR injury and relevant donor, recipient, and after LT clinical data were compiled., Results: Nrf2 expression was observed in all biopsies, both before and after IR. Some donor organs had greater expression of Nrf2 mRNA before IR injury, and these organs had lower Suzuki scores and better liver functions (ALT) after LT. Donors of livers with greater Nrf2 levels were significantly younger (40.5 yrs, range 28-53 yrs) than those with low Nrf2 levels (55.5 yrs, range 48-61 yrs), P<0.05., Conclusion: Livers from older donors have lower levels of Nrf2 perhaps exposing these organs to more IR-related damage.
- Published
- 2007
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30. Improved survival outcomes for liver transplantation.
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Qasim A, McCormick PA, Tajuddin T, Zaman MB, Traynor O, Hegarty J, and Geoghegan J
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- Adolescent, Adult, Aged, Female, Humans, Ireland epidemiology, Liver Diseases mortality, Male, Middle Aged, Prospective Studies, Survival Analysis, Time Factors, Tissue and Organ Procurement, Treatment Failure, Liver Diseases surgery, Liver Transplantation mortality, Treatment Outcome
- Abstract
Unlabelled: Liver transplantation is the treatment of choice for end stage liver disease and fulminant hepatic failure. Outcome of the procedure may be dependent on multiple factors including patient selection, donor selection, and centre experience., Aim: To determine whether the outcome for liver transplantation has improved over the time for the Irish National Liver Transplant Unit since its initial set up in 1993., Methods: All patients who underwent liver transplantation between Jan 1993 to Oct 2004 were included. Patients were sub-divided into three sequential cohorts of 90 patients each. Survival outcomes were compared between the groups., Results: 270 patients (male = 137) underwent 323 liver transplants (median age 49 yrs, range 16-68 yrs). Indications included primary biliary cirrhosis (14.1%), alcohol related liver disease (6.2%), fulminant hepatic failure (14.2%), primary sclerosing cholangitis (10.1%), chronic active hepatitis (9.5%), viral hepatitis (9.5%) and cryptogenic cirrhosis (7.1%). Most procedures (85.8%) were elective. Re-transplantation rates within the first 3 months of primary procedure were 9%, 5%, and 5% for the three chronological groups. Overall calculated 3-month, 1-year and 3 year survival rates for group 1 were 87%, 82% and 77%. For the groups 2 and 3 the figures were 86%, 81%, 77% and 89%, 89%, and 81% respectively. One- and 3-year survival rates were significantly better for group 3 compared to group 1 (p < 0.05)., Conclusions: Survival outcome has improved significantly over the past 12 years and is likely attributed to increasing experience of the transplant centre.
- Published
- 2007
31. MELD score as a prognostic model for listing acute liver failure patients for liver transplantation.
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Zaman MB, Hoti E, Qasim A, Maguire D, McCormick PA, Hegarty JE, Geoghegan JG, and Traynor O
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- Adult, Bilirubin blood, Female, Hepatic Encephalopathy classification, Hepatic Encephalopathy mortality, Hepatic Encephalopathy surgery, Humans, International Normalized Ratio, Liver Failure, Acute mortality, Liver Failure, Acute therapy, Male, Patient Selection, Prognosis, Retrospective Studies, Survival Analysis, Treatment Outcome, Liver Failure, Acute classification, Liver Failure, Acute surgery, Liver Transplantation statistics & numerical data, Waiting Lists
- Abstract
Objectives: The King's College Hospital (KCH) criteria are widely used for listing patients with acute liver failure (ALF) for liver transplantation (LT). Recent reports have suggested that the Model for End-Stage Liver Disease (MELD) score may be useful in assessing prognosis in ALF (nonparacetamol). This study compares prognostic accuracy of the two systems in patients with paracetamol (POD)-induced ALF treated in this unit., Methods: Seventy-two patients (average age 38 years; F:M ratio 2:1) admitted from 1994 to 2005 with POD-related ALF were studied. Clinical and biochemical parameters were recorded. The effect of applying a MELD score of greater than 30 as listing criteria for LT was calculated and compared with the KCH criteria. Outcomes were defined as LT, death, or full recovery., Results: Thirty-one patients (43%) recovered with medical therapy, 29 (40%) patients died, and 12 (17%) underwent LT. Sixty five percent of patients had a MELD > 30 and therefore could potentially be listed on admission; however, using KCH criteria only 24% patients were listed immediately. Sensitivity and negative predictive value of MELD was higher then KCH; however, we found KCH to have much higher specificity and positive predictive value., Conclusion: MELD has higher sensitivity and negative predictive value for POD-induced ALF than the KCH criteria. However, the high false-positive rate associated with MELD limits its clinical utility. The high negative predictive value of MELD score may allow it to be used in conjunction with KCH criteria to avoid unneeded LT in patients who will likely recover spontaneously.
- Published
- 2006
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32. A new simple synthesis of poly(thiophene-methine)s.
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Zaman MB and Perepichka DF
- Abstract
Acid-promoted polycondensation of 3,4-(ethylenedioxy)thiophene-2-carbaldehyde leads to a conjugated heavily p-doped poly(thiophene-methine), which can be dedoped leading to a low band-gap neutral polymer.
- Published
- 2005
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33. Synthesis and characterization of diverse coordination polymers. Linear and zigzag chains involving their structural transformation via intermolecular hydrogen-bonded, interpenetrating ladders polycatenane, and noninterpenetrating square grid from long, rigid N,N'-bidentate ligands: 1,4-bis[(x-pyridyl)ethynyl]benzene (x = 3 and 4).
- Author
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Zaman MB, Udachin K, Ripmeester JA, Smith MD, and zur Loye HC
- Abstract
The long, rigid ligands 1,4-bis[(3-pyridyl)ethynyl]benzene (L1) and 1,4-bis[(4-pyridyl)ethynyl]benzene (L2) were used in the synthesis of 10 new organic-inorganic coordination frameworks, each of them adopting different structural motifs. Synthesis, single-crystal X-ray structure determination, and spectroscopic and thermogravimetric analyses are presented. The reactions between M(NO3)2 x xH2O; M = Cd(II), Cu(II), and Co(II); x = 3-6 and Cu(hfac)2 x H2O [hfac = bis(hexafluoroacetylacetonato)] with L1 afforded the following one-dimensional zigzag chain structures: [Cd(C20H12N2)0.5(NO3)(CH3OH)]n (1, monoclinic, C2/c; a = 7.586(1) A, b = 23.222(1) A, c = 13.572(1) A, beta = 92.824(1), Z = 4); [{Cu(C20H12N2)(NO3)2(CH3OH)} x CH3OH]n (2, orthorhombic, P2(1)2(1)2(1); a = 8.589(1) A, b = 15.766(1) A, c = 17.501(1) A, Z = 4); [Co(C20H12N2)2(NO3)2(H2O)2] (5, triclinic, P1; a = 7.493(1) A, b = 8.948(1) A, c = 14.854(1) A, alpha = 100.427(1), beta = 97.324(1), gamma = 110.901(1), Z = 1); [Cu(C20H12N2)(hfac)2]n (4, monoclinic, C2/c, a = 18.828(1) A, b = 14.671(1) A, c = 13.427(1) A, beta = 90.447(1) degrees, Z = 4). Moreover, the minority phase compound formed from Cu(NO3)2 x 3H2O and L1 yielded a metallocyclic chain structure, [Cu(C20H12N2)(NO3)]n (3, triclinic, P; a = 8.728(1) A, b = 10.018(1) A, c = 11.893(1) A, alpha = 109.991(1), beta = 97.109(1), gamma = 115.542(1), Z = 1). In addition to the dinuclear coordination complex 5, all other polymeric structures (1-4) from L1 are composed of interpenetrating 2D and 3D cross-linked zigzag chains via hydrogen-bonding interactions. The reactions between M(NO3)2 x xH2O; M = Cd(II), Cu(II), and Co(II); x = 3-6 and Cu(hfac)2 x H2O [hfac = bis(hexafluoroacetylacetonato)] and L2 were dependent on the nature of the metal center and resulted in the formation of four different interpenetrating and noninterpenetrating compounds (6-10): [Co(C20H12N2)1.5(NO3)2]n (6, triclinic, P; a = 14.172(1) A, b = 15.795(1) A, c = 18.072(1) A, alpha = 115.380(1), beta = 101.319(1), gamma = 93.427(2), Z = 4), which consists of T-shaped building blocks assembled into three-dimensional interpenetrating polycatenated ladders; [Cd(C20H12N2)2(NO3)2]n (7, monoclinic, I2/a; a = 11.371(1) A, b = 20.311(2) A, c = 15.240(2) A, beta = 100.201(2) degrees, Z = 4), which adopts a two-dimensional noninterpenetrating square-grid motif; [Cu(C20H12N2)(hfac)2]n (8, monoclinic, I2/a; a = 11.371(1) A, b = 20.311(2) A, c = 15.240(2) A, beta = 100.201(2) degrees, Z = 4), composed of three sets of distinct one-dimensional linear chains; [Cu(C20H12N2)(EtOH)(NO3)2] [Cu(C20H12N2)1.5(NO3)2] x 2EtOH (9, triclinic, P; a = 12.248(2) A, b = 13.711(3) A, c = 18.257(4) A, alpha = 108.078(4) degrees, beta = 97.890(4) degrees, gamma = 103.139(5) degrees, Z = 2) and [Cu(C20H12N2)(MeOH)(NO3)2] [Cu(C20H12N2)1.5(NO3)2] x 2MeOH (10, triclinic, P; a = 12.136(1) A, b = 13.738(2) A, c = 17.563(3) A, alpha = 107.663(3) degrees, beta = 94.805(4) degrees, gamma = 104.021(4) degrees, Z = 2). Both 9 and 10 stack into infinite interpenetrating ladders through bundles of infinite chains and are described in our preliminary communication.
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- 2005
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34. Bis[mu-1,2-bis(2-pyridyl)ethyne-kappa(2)N:N']bis[aquadinitratocadmium(II)].
- Author
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Zaman MB, Davis MJ, Smith MD, and zur Loye HC
- Abstract
Two twisted 1,2-bis(2-pyridyl)ethyne ligands bridge two Cd(2+) centers in the C(2)-symmetric title complex, [Cd(2)(NO(3))(4)(mu-C(12)H(8)N(2))(2)(H(2)O)(2)]. The bridging ligands arch across one another creating a 'zigzag loop' molecular geometry. Two nitrate ions and a water molecule complete the irregular seven-coordinate Cd-atom environment. The dihedral angles between the equivalent pyridyl ring planes of the two independent ligands are 67.2 (1) degrees. O(water)-H.O(nitrate) hydrogen bonding creates two-dimensional layers parallel to the ab plane.
- Published
- 2003
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35. Synthesis and characterization of new linear pi-conjugated molecules containing bis(ethynylpyridine) units with a benzothiadiazole spacer.
- Author
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Akhtaruzzaman M, Tomura M, Zaman MB, Nishida J, and Yamashita Y
- Abstract
Three novel 4,7-bis(n-pyridylethynyl)-2,1,3-benzothiadiazoles (n = 2, 3, and 4) were synthesized by using the Sonogashira cross-coupling reaction of 4,7-dibromo-2,1,3-benzothiadiazole with the corresponding ethynylpyridines in the presence of a Pd(II) catalyst. The viologen analogues were also prepared by methylation of pyridyl nitrogen atoms. X-ray structure analysis of these compounds revealed the linear molecular structures with unusual columnar crystal structures. Insertion of a benzothiadiazole moiety into the acetylene-pyridine skeleton brings about a large increase in electron affinity and the bispyridyl compounds obtained here show high fluorescence quantum yields.
- Published
- 2002
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36. Organic/inorganic supramolecular channel frameworks containing a photosensitive azobenzene molecule as an included guest.
- Author
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Zaman MB, Udachin K, Akhtaruzzaman M, Yamashita Y, and Ripmeester JA
- Abstract
Two independent channel frameworks are occupied by photoactive E-azobenzene in an unprecedented one-dimensional zigzag motif and thus form virtual three-dimensional supramolecular host-guest networks.
- Published
- 2002
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37. New Cd(II)-, Co(II)-, and Cu(II)-containing coordination polymers synthesized by using the rigid ligand 1,2-bis(3-pyridyl)ethyne (3,3'-DPA).
- Author
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Zaman MB, Smith MD, Ciurtin DM, and zur Loye HC
- Abstract
Four new organic/inorganic coordination polymers, [Cd(C(10)H(8)N(2))(2)(H(2)O)(2)(NO(3))(2)](n)(1), [Co(C(10)H(8)N(2))(H(2)O)NO(3)CH(3)OH](n)(2), [Cu(C(10)H(8)N(2))(CH(3)OH)(NO(3))(2)](n) (3), and [Cu(C(10)H(8)N(2))(hfac)(2)](n)(4), were synthesized by using the rigid ligand 1,2-bis(3-pyridyl)ethyne (3,3'-DPA). Complex 1 crystallizes in space group P2/n: a = 12.462(2) A, b = 9.485(1) A, c = 13.383(2) A, beta = 96.629(2) degrees, V = 1559.6(3) A(3), Z = 4. Complex 2 crystallizes in space group Fddd: a = 9.248(4) A, b = 19.982(7) A, c = 35.093(16) A, V = 6485.0(4) A(3), Z = 8. Complex 3 crystallizes in space group I2/a: a = 18.315(2) A, b = 8.517(1) A, c = 20.494(3) A, beta = 104.042(2) degrees, V = 3101.2(7) A(3), Z = 8. Complex 4 crystallizes in space group P21/c: a = 6.576(1) A, b = 16.189(1) A, c = 11.653(1) A, beta = 91.337(1) degrees, V = 1240.3(2) A(3), Z = 2. The coordination polymers display a variety of structural architectures, ranging from sinusoidal and zigzag chains (1, 3, 4) to two-dimensional channel-type architectures (2). The effects of the orientation of the nitrogen atom in the pyridine rings on the resultant structures are discussed.
- Published
- 2002
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38. Two different one-dimensional structural motifs in the same coordination polymer: a novel interpenetration of infinite ladders by bundles of infinite chains.
- Author
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Zaman MB, Smith MD, and zur Loye HC
- Abstract
A coordination polymer with a novel structural motif consisting of stacks of infinite ladders interpenetrated by bundles of infinite chains is described; geometrical arguments are made for the requirements that can lead to such interpenetration as a function of ligand dimensions.
- Published
- 2001
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39. Crystal engineering using anilic acids and dipyridyl compounds through a new supramolecular synthon.
- Author
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Zaman MB, Tomura M, and Yamashita Y
- Abstract
The anilic acids, 2,5-dihydroxy-1,4-benzoquinone (1a), 2,5-dibromo-3,6-dihydroxy-1,4-benzoquinone (bromanilic acid; 1b), 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid; 1c), and 2,5-dicyano-3,6-dihydroxy-1,4-benzoquinone (cyananilic acid; 1d), were cocrystallized with rigid organic ligands containing two pyridine rings, 2,4-bipyridine (2a), 4,4'-bipyridine (2b), 1,2-bis(2-pyridyl)ethylene (3a), 1,2-bis(4-pyridyl)ethylene (3b), 2,2'-dipyridylacetylene (4a), 3,3'-dipyridylacetylene (4b), and 4,4'-dipyridylacetylene (4c). Fourteen complexes 5-18 were obtained as single crystals, and their crystal structures were successfully determined by X-ray analysis. All complexes except those with 2a are 1:1 and are composed of an infinite linear or zigzag tape structure, the formation of which is ascribed to intermolecular O-H...N, N(+)-H...O, or N(+)-H...O(-) hydrogen bonds or a combination of these between the anilic acids and the dipyridyl compounds. In the complexes 5 and 6, no infinite tape structure is observed although the molecular units connected by a similar hydrogen-bonding pattern are formed. For the 1:1 complexes, we have found two types of stacking arrangements, segregated stacks (7, 9, 12-15, 18) and alternated ones (8, 10, 11, 16, 17). In the complexes of 1c with the series of dipyridylacetylenes 4 (14, 15, 17), the neutral, dication, and monocaction states are formed depending on the nitrogen positions, which can be attributed to the different basicity of the pyridyl groups.
- Published
- 2001
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40. Linear hydrogen-bonded molecular tapes in the cocrystals of squaric acid with 4,4'-dipyridylacetylene and 1,2-bis(4-pyridyl)ethylene.
- Author
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Zaman MB, Tomura M, and Yamashita Y
- Abstract
The title compounds, 4,4'-(ethyne-1,2-diyl)dipyridinium bis(squarate), C(12)H(10)N(2)(2+).2C(4)HO(4)(-), and 4,4'-(ethene-1,2-diyl)dipyridinium bis(squarate), C(12)H(12)N(2)(2+).2C(4)HO(4)(-), are isomorphous and crystallize in space group P-1. The cocrystals contain linear hydrogen-bonded molecular tape structures along the [120] direction. The squarate monoanions form a ten-membered dimer linked by two intermolecular O-H.O hydrogen bonds. Each component molecule forms a segregated stack along the c axis. The bond lengths of the squarate monoanion indicate delocalization of the enolate anion.
- Published
- 2001
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41. New hydrogen-bonded donor-acceptor pairs between dipyridylacetylenes and 2,5-dichloro-3,6-dihydroxyl-1,4-benzoquinone
- Author
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Zaman MB, Tomura M, and Yamashita Y
- Abstract
[structure: see text] The crystalline donor-acceptor hydrogen-bonding complexes between 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid) and dipyridylacetylenes (DPA) [2,2'-DPA, 3,3'-DPA, and 4,4'-DPA] were prepared, and crystal structures were revealed by X-ray analysis. The structures of the complexes are formed by intermolecular hydrogen-bonding interactions and demonstrate three supramolecular architectures based on a new common supramolecular synthon, which allows the formation of a different stacking arrangement and ionicity.
- Published
- 2000
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42. Dietary beta carotene and lung cancer risk in U.S. nonsmokers.
- Author
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Mayne ST, Janerich DT, Greenwald P, Chorost S, Tucci C, Zaman MB, Melamed MR, Kiely M, and McKneally MF
- Subjects
- Adult, Aged, Aged, 80 and over, Case-Control Studies, Dose-Response Relationship, Drug, Female, Fruit, Humans, Male, Middle Aged, Multivariate Analysis, New York, Smoking adverse effects, Vegetables, Vitamin A administration & dosage, Vitamin E administration & dosage, beta Carotene, Carotenoids administration & dosage, Diet, Lung Neoplasms prevention & control
- Abstract
Background: Approximately 15% of all lung cancer deaths in the United States (about 22,350 deaths annually) may not be directly attributable to active cigarette smoking. Consumption of beta carotene, which is derived almost exclusively from intake of fruits and vegetables, has been associated with a reduced risk of lung cancer in smokers. However, studies examining this association in nonsmokers, particularly nonsmoking men, are limited., Purpose: The purpose of this study was to examine whether dietary factors including beta carotene and retinol are associated with a reduced risk for lung cancer in nonsmoking men and women., Methods: A population-based, matched case-control study of lung cancer in nonsmokers was conducted in New York State from 1982 to 1985. Dietary interviews were completed for 413 individually matched case-control pairs of subjects. To determine whether the relationship between dietary intake from specific food groups and lung cancer differed by type of interview, smoking history, sex, age, or histologic type, we examined data on the case-control pairs from each subgroup separately. The intake of beta carotene and retinol was calculated as the weighted sum of the monthly frequencies of consumption of food items containing these nutrients, where the weights correspond to the nutrient content of a typical portion of the food items., Results: Consumption of greens (P for trend < .01), fresh fruits (P for trend < .01), and cheese (P for trend < .05) was associated with a significant dose-dependent reduction in risk for lung cancer, whereas consumption of whole milk (P for trend < .01) was associated with a significant dose-dependent increase in risk. Use of vitamin E supplements was also protective (odds ratio = 0.55; 95% confidence interval [CI] = 0.35-0.85). Increased consumption of the following food groups was associated with a reduction in risk among females: vegetables (P for trend < .025), raw fruits and vegetables (P for trend < .005), and dairy products (P for trend < .025). In males, increased consumption of raw fruits and vegetables was associated with a reduced risk for lung cancer (P for trend < .005). Dietary beta carotene (OR = 0.70; 95% CI = 0.50-0.99), but not retinol (OR = 0.98; 95% CI = 0.82-1.17), was significantly associated with risk reduction., Conclusions: This is the largest study to date of dietary factors and lung cancer in nonsmokers; results suggest that dietary beta carotene, raw fruits and vegetables, and vitamin E supplements reduce the risk of lung cancer in nonsmoking men and women.
- Published
- 1994
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43. Treatment and prognosis in bronchial carcinoids involving regional lymph nodes.
- Author
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Martini N, Zaman MB, Bains MS, Burt ME, McCormack PM, Rusch VW, and Ginsberg RJ
- Subjects
- Adolescent, Adult, Aged, Bronchial Neoplasms mortality, Bronchial Neoplasms pathology, Carcinoid Tumor mortality, Carcinoid Tumor pathology, Female, Humans, Lymph Node Excision, Lymphatic Metastasis, Male, Middle Aged, Neoplasm Recurrence, Local, Prognosis, Survival Rate, Bronchial Neoplasms surgery, Carcinoid Tumor surgery
- Abstract
From 1953 to 1992, 25 patients were surgically treated for bronchial carcinoids with metastases to regional lymph nodes (N1 or N2). The tumors were located centrally, involving main or lobar bronchi in 12 patients and were peripheral in 13. Histologically, 12 of the carcinoids were classified as typical and 13 as atypical (neuroendocrine carcinoma). Pneumonectomy was performed in 11 patients, sleeve lobectomy in one, lobectomy in seven and bilobectomy in six. A formal mediastinal lymph node dissection was done in 20 patients. At final staging, 10 had N1 disease and 15 had N2. No adjuvant treatment was given to the 10 patients with N1 disease. External radiation therapy was given after the operation to 9 of 15 patients with N2 disease. The overall 5-year survival (Kaplan-Meier) was 75% (median 62 months). No difference in survival was found between patients with N1 or N2 disease. However, survival and recurrence rate differed between typical and atypical carcinoids. In typical carcinoids, the 5-year survival was 92% and, in atypical carcinoids, it was 60% (p = 0.02). We conclude that complete resection for bronchial carcinoids results in long-term survival despite the presence of regional lymph node metastases. Recurrence appears to depend more on cell type than nodal status. Postoperative radiation therapy does not appear to be beneficial.
- Published
- 1994
44. Pathologic complete response in advanced non-small-cell lung cancer following preoperative chemotherapy: implications for the design of future non-small-cell lung cancer combined modality trials.
- Author
-
Pisters KM, Kris MG, Gralla RJ, Zaman MB, Heelan RT, and Martini N
- Subjects
- Adult, Aged, Carcinoma, Non-Small-Cell Lung therapy, Cisplatin administration & dosage, Combined Modality Therapy, Female, Humans, Lung Neoplasms therapy, Male, Middle Aged, Mitomycin administration & dosage, Mitomycins administration & dosage, Survival Analysis, Treatment Outcome, Vinblastine administration & dosage, Vindesine administration & dosage, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Carcinoma, Non-Small-Cell Lung drug therapy, Lung Neoplasms drug therapy
- Abstract
Purpose: This report determines the incidence of pathologic complete response in patients with locally advanced non-small-cell lung cancer (NSCLC) treated with mitomycin, vinca alkaloid, and high-dose cisplatin (MVP) chemotherapy, and estimates the effect of MVP on survival., Patients and Methods: We have identified and reviewed the course of 21 patients with advanced NSCLC who achieved a pathologic complete response following a median of three preoperative MVP combination chemotherapy courses including vinblastine or vindesine, cisplatin (120 mg/m2), and mitomycin (n = 19)., Results: All patients had a major objective response following preoperative chemotherapy and nine (43%) had a clinical complete response. Nine patients with pathologic complete responses were among 73 entered on a preoperative chemotherapy program, yielding an incidence estimate of 12% (95% confidence interval, 6% to 22%). The median survival duration for all 21 patients has not been reached. The median follow-up duration is now 68 months (range, 17 to 109). Survival estimates are 90% at 1 year, 62% at 3 years, and 54% at 5 years. Nine patients have relapsed with initial sites of recurrence as follows: brain (n = 5), other systemic sites (n = 3), and locoregional (n = 1). One patient died in the postoperative period. Eleven patients remain disease-free and all have excellent functional status., Conclusion: We have observed pathologic complete responses in approximately 12% of advanced NSCLC patients treated with preoperative MVP chemotherapy. These pathologically determined responses were seen only in patients with major objective responses clinically. Pathologic complete response predicts excellent survival and functional level and should be considered a major end point in the evaluation of preoperative chemotherapy programs.
- Published
- 1993
- Full Text
- View/download PDF
45. Negative predictive value of pulmonary fine needle aspiration cytology.
- Author
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Zakowski MF, Gatscha RM, and Zaman MB
- Subjects
- Adult, Aged, False Negative Reactions, Female, Humans, Male, Middle Aged, Predictive Value of Tests, Retrospective Studies, Biopsy, Needle, Lung Neoplasms pathology
- Abstract
Percutaneous fine needle aspiration (FNA) for cytologic examination is an accepted and reliable technique for diagnosing neoplasia. It is less useful, however, in excluding that diagnosis. We performed a retrospective analysis of a consecutive series of pulmonary FNA specimens at Memorial Sloan-Kettering Cancer Center to determine the negative predictive value (NPV) of this technique in the setting of a large cancer hospital. Fifty-seven cases were studied. Six cases (10.5%) were initially diagnosed as negative but acellular and were not further analyzed, and another 6 were lost to follow-up; 24 cases (42.1%) were subsequently confirmed negative by tissue or clinical follow-up, and 21 of the cases (36.8%) were proven positive for malignancy by repeat aspiration, tissue diagnosis or clinical means. Of these 21 cases, 1 was misdiagnosed as negative, and review demonstrated malignant cells on the slide; 3 of the 21 cases should have been initially rejected as unsatisfactory, and 18 of the 21 contained material sufficient for a cytologic diagnosis but not representative of the lesion. On follow-up the false-negative cases showed primary adenocarcinoma, epidermoid carcinoma, lymphoma, metastatic breast carcinoma and metastatic sarcoma. Specific benign diagnoses were made on the initial cytologic preparation in three cases. No benign tumors were found. The NPV in our series was 53.3%, comparable to values in previous reports. The single largest factor contributing to false-negative diagnoses is sampling error, and we recommend repeat aspiration when no specific benign diagnosis is made. In addition, we suggest that the diagnoses of negative for malignant cells and insufficient for diagnosis or acellular be considered separate categories.
- Published
- 1992
46. Bilateral bronchoalveolar lavage in the diagnosis of opportunistic pulmonary infections.
- Author
-
Meduri GU, Stover DE, Greeno RA, Nash T, and Zaman MB
- Subjects
- Adult, Aged, Biopsy, Bronchi pathology, Bronchoalveolar Lavage Fluid microbiology, Bronchoscopy, Cytomegalovirus Infections microbiology, Cytomegalovirus Infections pathology, Female, Humans, Male, Middle Aged, Opportunistic Infections pathology, Pneumonia, Pneumocystis complications, Pneumonia, Pneumocystis microbiology, Pneumonia, Pneumocystis pathology, Pneumonia, Viral microbiology, Pneumonia, Viral pathology, Prospective Studies, Acquired Immunodeficiency Syndrome complications, Bronchoalveolar Lavage Fluid pathology, Cytomegalovirus Infections diagnosis, Opportunistic Infections diagnosis, Pneumonia, Pneumocystis diagnosis, Pneumonia, Viral diagnosis
- Abstract
To further improve the diagnostic value of bronchoscopy in the immunosuppressed population presenting with diffuse pulmonary infiltrates, we prospectively investigated the utility of bilateral bronchoalveolar lavage (BAL). We performed 62 bronchoscopies on 52 immunosuppressed patients. Of the 52 patients, 33 had pulmonary infections. The yield for Pneumocystis carinii pneumonia on bilateral BAL was 94 percent (31/33), compared to the 84 percent (51/61) previously obtained with unilateral BAL in our institution. The recovery of P carinii was unilateral in four of five patients without AIDS and in four of 26 patients with AIDS. Transbronchial biopsy gave a yield of 85 percent (11/13). In ten patients with definitive cytomegalovirus (CMV) pneumonia, recovery of CMV by combined culture and cytology was 100 percent. Of nine bronchoscopies with positive cytology for CMV, five showed cytopathologic changes in the BAL from both sides and four in the BAL from one side only. No complications were seen in the 14 patients with thrombocytopenia or the five patients receiving mechanical ventilation. Our findings indicate that bilateral BAL significantly increases the yield for recovery of P carinii (p less than 0.02) and CMV (p less than 0.001) in immunosuppressed patients.
- Published
- 1991
- Full Text
- View/download PDF
47. Pulmonary cytology.
- Author
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Zaman MB
- Subjects
- Biopsy, Needle, Bronchoscopy, Humans, Lung Diseases pathology, Lung Neoplasms pathology, Sputum cytology, Cytodiagnosis, Lung Diseases diagnosis, Lung Neoplasms diagnosis
- Abstract
Cytomorphologic criteria for the diagnosis and classification of primary pulmonary carcinomas are described and illustrated. Helpful hints for the differential diagnosis from benign entities and tumors and the cytologic limitations are stated. The fact that pulmonary cytologic interpretations must be made in the light of accurate clinical presentation is emphasized.
- Published
- 1991
48. Extrathoracic metastatic malignant thymoma. Diagnosis by aspiration cytology.
- Author
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Hoda SA, Warren GP, and Zaman MB
- Subjects
- Biopsy, Needle, Humans, Immunohistochemistry, Liver Neoplasms metabolism, Liver Neoplasms pathology, Lymphocytes pathology, Male, Middle Aged, Thymoma metabolism, Thymoma pathology, Liver Neoplasms secondary, Thymoma secondary, Thymus Neoplasms pathology
- Abstract
A fine-needle aspirate from a hepatic mass in a 65-year-old white man was examined. The patient had a history of histologically confirmed thymoma with metastases in multiple thoracic sites. The smears showed a dimorphic population of epithelial cells and lymphocytes, characteristic of thymoma. The resemblance of the cytologic pattern to the primary neoplasm and positive reactivity with various immunohistochemical agents peculiar to thymomas confirmed the diagnosis. Aspiration cytology has been described in the diagnosis of primary thymoma. To our knowledge, this is the second reported case of a cytologic diagnosis of metastatic thymoma and the first one with immunohistochemical studies.
- Published
- 1991
49. Aerosolized pentamidine: effect on diagnosis and presentation of Pneumocystis carinii pneumonia.
- Author
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Jules-Elysee KM, Stover DE, Zaman MB, Bernard EM, and White DA
- Subjects
- Aerosols, Biopsy, Bronchi pathology, Bronchoscopy, Gallium Radioisotopes, HIV Infections complications, Humans, Lung diagnostic imaging, Pentamidine administration & dosage, Pneumonia, Pneumocystis prevention & control, Radiography, Recurrence, Severity of Illness Index, Zidovudine pharmacology, Bronchoalveolar Lavage Fluid microbiology, Pentamidine pharmacology, Pneumonia, Pneumocystis diagnosis
- Abstract
Study Objective: To determine the effect of previous aerosolized pentamidine therapy on diagnosis and presentation of Pneumocystis carinii pneumonia., Design: A retrospective study., Setting: A tertiary care hospital., Patients: Fifty-two consecutive patients with P. carinii pneumonia and underlying infection with the human immunodeficiency virus (HIV) who had bronchoscopy. Twenty-one patients who were on aerosolized pentamidine therapy served as the study group. Thirty-one patients who had not received the drug served as the control group., Measurements and Main Results: The yield of bronchoalveolar lavage for P. carinii pneumonia was 62% for the study group and 100% for the control group (P less than 0.05). This lower yield was significant for the subset of patients having their first episode of P. carinii pneumonia. The yield of transbronchial biopsy was similar for both groups of patients (81% compared with 84%). The yield of bronchoscopy was not influenced by use of zidovudine. Review of lavage specimen slides suggested that there may be fewer organisms present in patients receiving aerosolized pentamidine. An atypical roentgenographic presentation of upper lobe predominant infiltrates was seen in 38% of the study patients and 7% of the control patients. In addition, pneumothoraces and cystic changes were also frequently seen in the study patients. Gallium scans, when done, were also atypical in the study group. Markers of the severity of disease, however, were similar in both groups., Conclusion: The yield of bronchoalveolar lavage for P. carinii pneumonia in HIV-infected patients is lower in patients receiving aerosolized pentamidine. Unusual roentgenographic presentations and atypical gallium scans are also found in this setting.
- Published
- 1990
- Full Text
- View/download PDF
50. Primary melanocarcinoma of the esophagus.
- Author
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McCormack PM, Nascimento AG, Bains MS, Knapper WH, and Zaman MB
- Subjects
- Aged, Esophageal Neoplasms therapy, Female, Humans, Male, Melanoma therapy, Middle Aged, Esophageal Neoplasms pathology, Melanoma pathology
- Published
- 1979
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