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The intestine is a highly metabolic tissue, but the metabolic programs that influence intestinal crypt proliferation, differentiation, and regeneration are still emerging. Here, we investigate how mitochondrial sirtuin 4 (SIRT4) affects intestinal homeostasis. Intestinal SIRT4 loss promotes cell proliferation in the intestine following ionizing radiation (IR). SIRT4 functions as a tumor suppressor in a mouse model of intestinal cancer, and SIRT4 loss drives dysregulated glutamine and nucleotide metabolism in intestinal adenomas. Intestinal organoids lacking SIRT4 display increased proliferation after IR stress, along with increased glutamine uptake and a shift toward de novo nucleotide biosynthesis over salvage pathways. Inhibition of de novo nucleotide biosynthesis diminishes the growth advantage of SIRT4-deficient organoids after IR stress. This work establishes SIRT4 as a modulator of intestinal metabolism and homeostasis in the setting of DNA-damaging stress., Competing Interests: Declaration of interests M.C.H. received research funding from Agilent Technologies and Roche Pharmaceuticals. M.C.H. serves on the scientific advisory boards of Alixia, Minovia, and MitoQ and is on the editorial boards of Cell Metabolism and Molecular Cell. S.V. served as a Cell Reports editor between 2018 and 2021 and is currently the lead editor for Cell Press Multi-Journal Submission. She carried out the work reported in this paper before joining Cell Press. She was not given access to information related to the peer review of this paper, nor did she participate in the decision-making process. K.M.H. received research funding from Novartis and TUO Therapeutics., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Delivery of antineoplastic regimens in the pediatric setting is facilitated by a paper roadmap. Paper roadmaps are the key safety tool required for safe ordering. Electronic medical record systems offer technological solutions for ordering antineoplastic regimens, however, do not offer a solution that integrates paper roadmaps digitally., Methods: A multidisciplinary project team implemented real-time clinician scanning of paper roadmaps into the electronic medical record., Results: The rate of missing roadmaps decreased from an average of 1.6 to 0.8 per week. Pharmacists gained 3 h of productivity daily. Providers spend an average of 35-45 s and a total of seven clicks each time a roadmap is scanned. Overall, the clinical systems analyst spent less than 1 h of total build time., Conclusion: Implementing roadmap scanning decreased the rate of missing roadmaps, increased pharmacist productivity, and required a nominal amount of analyst and provider time. In addition, this solution allows for concurrent viewing of the roadmap files from any connected computer, facilitating an easier co-signature process for providers, pharmacists, and nurses., Practice Implications: These results suggest that implementing real-time scanning of roadmaps can improve oncology care efficiency while maintaining the same safety rigor that paper roadmaps offer.

Ulcerative colitis (UC) is a complex, multifactorial disease driven by a dysregulated immune response against host commensal microbes. Despite rapid advances in our understanding of host genomics and transcriptomics, the metabolic changes in UC remain poorly understood. We thus sought to investigate distinguishing metabolic features of the UC colon (14 controls and 19 patients). Metabolomics analyses revealed inflammation state as the primary driver of metabolic variation rather than diagnosis, with multiple metabolites differentially regulated between inflamed and uninflamed tissues. Specifically, inflamed tissues were characterized by reduced levels of nicotinamide adenine dinucleotide (NAD+) and enhanced levels of nicotinamide (NAM) and adenosine diphosphate ribose (ADPr). The NAD+/NAM ratio, which was reduced in inflamed patients, served as an effective classifier for inflammation in UC. Mitochondria were also structurally altered in UC, with UC patient colonocytes displaying reduced mitochondrial density and number. Together, these findings suggest a link between mitochondrial dysfunction, inflammation, and NAD+ metabolism in UC., Competing Interests: The authors have declared that no competing interests exist.

Upon nutrient stimulation, pre-adipocytes undergo differentiation to transform into mature adipocytes capable of storing nutrients as fat. We profiled cellular metabolite consumption to identify early metabolic drivers of adipocyte differentiation. We find that adipocyte differentiation raises the uptake and consumption of numerous amino acids. In particular, branched-chain amino acid (BCAA) catabolism precedes and promotes peroxisome proliferator-activated receptor gamma (PPARγ), a key regulator of adipogenesis. In early adipogenesis, the mitochondrial sirtuin SIRT4 elevates BCAA catabolism through the activation of methylcrotonyl-coenzyme A (CoA) carboxylase (MCCC). MCCC supports leucine oxidation by catalyzing the carboxylation of 3-methylcrotonyl-CoA to 3-methylglutaconyl-CoA. Sirtuin 4 (SIRT4) expression is decreased in adipose tissue of numerous diabetic mouse models, and its expression is most correlated with BCAA enzymes, suggesting a potential role for SIRT4 in adipose pathology through the alteration of BCAA metabolism. In summary, this work provides a temporal analysis of adipocyte differentiation and uncovers early metabolic events that stimulate transcriptional reprogramming., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Growing appreciation of the diversity of post-translational modifications (PTMs) in the mitochondria necessitates reevaluation of the roles these modifications play in both health and disease. Compared to the cytosol and nucleus, the mitochondrial proteome is highly acylated, and remodeling of the mitochondrial "acylome" is a key adaptive mechanism that regulates fundamental aspects of mitochondrial biology. It is clear that we need to understand the underlying chemistry that regulates mitochondrial acylation, as well as how chemical properties of the acyl chain impact biological functions. Here, we dissect the sources of PTMs in the mitochondria, review major mitochondrial pathways that control levels of PTMs, and highlight how sirtuin enzymes respond to the bioenergetic state of the cell via NAD + availability to regulate mitochondrial biology. By providing a framework connecting the chemistry of these modifications, their biochemical consequences, and the pathways that regulate the levels of acyl PTMs, we will gain a deeper understanding of the physiological significance of mitochondrial acylation and its role in mitochondrial adaptation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To report a large number of highly active patients who underwent arthroscopic Bankart repair at our institution over the last decade., Methods: A retrospective analysis of patients who underwent primary and revision arthroscopic Bankart repairs using bioabsorbable anchors was performed. Outcome measures included recurrence of dislocation, American Shoulder and Elbow Scores (ASES), Rowe, visual analog scale (VAS), return to sports, and satisfaction scores., Results: A total of 94 shoulders met the inclusion criteria. The recurrence rate was 6/94 (6.4%) at a mean follow-up of 5 years (range, 3 to 8.3). The mean postoperative scores were as follows: ASES = 91.5/100; Rowe = 84.3/100; VAS = 0.8/10; satisfaction = 8.8/10. In those who attempted to return to sports, 82.5% were able to return to the same level of competition. Statistical analyses revealed a significant increase in risk of recurrence among high school and recreational athletes. No recurrences were observed among professional or college-level athletes. No significant difference in recurrence rates was observed in regards to age, time to surgery, type of athlete (collision v limited contact), repair of SLAP lesion, number of anchors, or revision surgery., Conclusions: Although several repair techniques exist for traumatic anterior shoulder instability, arthroscopic repair remains a viable option even in a highly active patient population. This study uniquely identified high school and recreational athletes at higher risk for recurrence. This is perhaps due to inferior shoulder development and technique as well as to limited access to postoperative physical therapy., Level of Evidence: Level IV, therapeutic case series., (Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Training to excellence in the conduct of surgical procedures has many similarities to the acquisition and mastery of technical skills in elite-level music and sports. By using coaching techniques and strategies gleaned from analysis of professional music ensembles and athletic training, surgical educators can set conditions that increase the success rate of training to elite performance. This article describes techniques and strategies used in both music and athletic coaching, and it discusses how they can be applied and integrated into surgical simulation and education., (Published by Elsevier Inc.)

Background: The overhead-throwing athlete is a unique patient, requiring an elite, precise functional ability. Superior labral tears are quite common, and the percentage of athletes who return to play after superior labrum anterior-posterior (SLAP) repair has been variable. A tear of the infraspinatus caused by either internal impingement or tension overload may compromise this return., Hypothesis: The rate of return to a level of play similar to or greater than the preinjury level after repair of combined SLAP and infraspinatus injuries will be lower than in previous reports of SLAP repair alone., Study Design: Case series; Level of evidence, 4., Methods: In the current study, we examined a series of overhead-throwing athletes with diagnoses of both a SLAP tear and a significant (>50%) tear of the infraspinatus tendon who underwent surgical repair of both injuries. We identified 17 high-level baseball players younger than 25 years who underwent simultaneous arthroscopic repairs of a SLAP tear with a standard suture anchor technique and of an infraspinatus tear with either a free polydioxanone (PDS) suture or suture anchor between 2005 and 2008. The postoperative records of all patients were reviewed to determine their ability to return to play and their postoperative level of performance. All patients were then contacted to determine their Kerlan-Jobe Orthopaedic Clinic Overhead Athlete Shoulder and Elbow score and their current sport participation level., Results: All 17 patients in the series attempted to return to their prior sport after completion of postoperative rehabilitation. Only 6 patients (35%) were able to return to the same or a superior preinjury level of performance. Five of the remaining 11 patients returned to play at a lower level, either playing the same position or else forced to switch to another position of play because of a decline in throwing velocity. Six patients were unable to return to play. No complications or reoperations occurred in any of the patients following surgery., Conclusion: A significant (>50%) tear of the infraspinatus in combination with glenohumeral internal rotation deficit (GIRD) and SLAP tears in the throwing athlete results in a guarded prognosis in return to play at the same level. While the rates of return to play in overhead-throwing athletes with an isolated SLAP tear have historically been encouraging, the prognosis for an athlete with both a SLAP and infraspinatus tear is more guarded. These patients are not likely to return to their preinjury level of play.

Dendritic polymers have a wide range of potential applications; however, the extensive synthesis and limited availability of bulk quantities of dendrimers restrict their use. Core-based hyperbranched polymers (CBHPs) are, therefore, an attractive alternative to dendrimers for many applications. The selectivity of core-based hyperbranched poly(ethyleneimine), as a host for phenol blue and 2-hydroxy Nile red guests, was investigated using absorption and fluorescence spectroscopies. Research results are compared to those for its dendritic counterpart, poly(propyleneimine). Phenol blue is known to associate near the core in both the CBHPs and dendrimers investigated. The interfering agent, 2-hydroxy Nile red, has also been shown to associate with these polymers; however, this interaction occurs in the outermost branches. In this work, it was found that phenol blue was sequestered in both the CBHPs and dendrimers in the presence of interfering agent, and this association appeared to be the same as that of the polymers with phenol blue alone. Although the presence of 2-hydroxy Nile red did affect the association of phenol blue, there was still considerable association even when 2-hydroxy Nile red was in 10-fold excess. The association of phenol blue with both the CBHPs and dendrimers was stable and robust; however, the association of 2-hydroxy Nile red was relatively weak and unstable.

Randomly hyperbranched polymers containing a core region are a relatively new subclass of materials. In comparison to dendrimeric polymers, there are many similarities, including their proposed applications. Because the core-based hyperbranched polymers can be prepared in a one-pot synthesis, they are an attractive alternative to the dendrimers, which require a laborious multistep process. This research is centered around the comparison of core-based, randomly hyperbranched poly(ethyleneimine) with the dendrimeric poly(propyleneimine) to better understand their host-guest properties. Two sizes of each polymer class were examined, and studies were carried out using the solvatochromic reporter molecule phenol blue. Absorbance and fluorescence measurements (emission and anisotropy) were utilized to determine the location of the fluorophore within the polymer. Results indicate that the phenol blue does associate with both the hyperbranched poly(ethyleneimine) and the dendrmeric poly(propyleneimine), although the association is not the same for the two polymer classes. The loading capacity of both polymer classes was also determined.

With unique 3-D architecture, the application of core-based hyperbranched polyethyleneimine (CHPEI), as a capillary coating in capillary electrophoresis, is demonstrated by manipulation of the electroosmotic mobility (EOF). CHPEI coatings (CHPEI5, M(w) approximately 5000 and CHPEI25, M(w) approximately 25,000) were physically adsorbed onto the inner surface of bare fused-silica capillary (BFS) via electrostatic interaction of the oppositely charged molecules by rinsing the capillaries with different CHPEI aqueous solutions. The EOF values of the coated capillaries were measured over the pH range of 4.0-9.0. At higher pH (pH >6) the coated capillary surface possesses excess negative charges, which causes the reversal of the EOF. The magnitudes of the EOF obtained from the coated capillaries were three-fold lower than that of BFS capillary. Desirable reproducibility of the EOF with % RSD (n = 5) < or = 2 was obtained. Effect of ionic strength, stability of the coating (% RSD = 0.3) and the dependence of the EOF on pH (% RSD = 0.5) were also investigated. The CHPEI-coated capillaries were successfully utilized to separate phenolic compounds, B vitamins, as well as basic drugs and related compounds with reasonable analysis time (< 20 min) and acceptable migration-time repeatability (< 0.7% RSD for intra-capillary and < 2% RSD for inter-capillary).

This work illustrates the remarkable ability of amine-terminated PAMAM dendrimers to entrap multiple guest molecules. While previous encapsulation studies with dendritic polymers demonstrated multi-dye uptake, the dendrimers required extensive synthetic modification. This study utilizes unmodified PAMAM dendrimers to encapsulate multiple phenol blue molecules. Quantitative data on the uptake capacity and robustness of association is presented.

Photodynamic therapy (PDT) involves the use of photochemical reactions mediated through the interaction of photosensitizing agents, light and oxygen. PDT, while now commonly used in physician ophthalmology and oncology, is uncommonly used for the veterinary ophthalmic patient. It is an emerging new therapy in veterinary ophthalmology for the treatment of periocular tumors. This article reviews the basic principles of PDT to provide the veterinary ophthalmologic community with a succinct reference for this emerging treatment modality in our field.

Pyrogallol[4]arenes form stable hydrogen-bonded nanocapsules that have unique properties that may make them suitable for diverse applications, such as catalysts and molecular transporters. Little is known about the behavior of the interior of these new materials in solution, and by using the solvent-dependent properties of 1-(9-anthryl)-3-(4-dimethylaniline) propane (ADMA), the inner phase properties of the hexamers are investigated. Steady-state and dynamic spectrofluorometric results are in agreement, are consistent with solid-state studies, and indicate that the majority of ADMA is sequestered in an extended conformation with the crystallization solvent. The conformational flexibility of ADMA is attributed to lower capsule occupancies ( approximately 50%, i.e., 1 molecule per 2 capsules, one occupied and one empty) relative to our previous study with pyrene butyric acid (occupancy of 150%, i.e., 1.5 molecules per capsule) in which the probe was restricted within a nanocapsule. The nature of the encapsulated ADMA complexes are found to change with time, as there is either fluorophore leaching from the capsule or endo-exo-capsule solvent exchange. However, the choice of crystallizing solvent (ethyl acetate or acetonitrile) and PgC(n) alkyl tail (C(6) or C(10)) does not influence experimental outcomes. These research findings give a better understanding of the encapsulation versatility of these unique supramolecular assemblies and the protective nanopockets that can exist for guest molecules.

Photolysis of the uranyl(VI) Schiff base complex UO2(tBu4-salphen)(THF) (1a) with cobaltocene in THF affords [Cp2Co][UO2(tBu4-salphen)(OH)] (2) in high yield while irradiation in toluene yields no reaction. Electronic emission spectra of 1a reveal a large Stokes' shift in toluene similar to that observed in the free ligand, while in THF the structural rearrangement responsible for this shift is blocked. Instead, the ligand-centered excited state is redirected to the uranyl(VI) center by way of energy transfer, thus generating 2 from the intramolecular activation of a coordinated THF molecule.

Selectivity of amine-terminated poly(amidoamine) (PAMAM-AT) dendrimers as host molecules for phenol blue and Nile red guests was investigated using absorption and fluorescence spectroscopies. Phenol blue has been known to associate near the core in the PAMAM-AT dendrimers. Nile red has also been shown to associate with this dendrimer family; however, this occurs in the outermost branches. Concentration ratios and generational dependencies were investigated. It was found that phenol blue was sequestered in the PAMAM-AT dendrimers in the presence of the interfering Nile red, and this association appeared to be the same as that of PAMAM-AT with phenol blue alone. As the concentration of Nile red increased relative to the concentration of phenol blue, the desired association of phenol blue became increasingly hindered. While the presence of Nile red did affect association, phenol blue still had considerable association even when Nile red was in ten-fold excess. The association of phenol blue with PAMAM-AT was stable and robust; however, Nile red's association was relatively weak and unstable.

Despite recent strides in the synthesis of elaborate nanometer-scale molecular hosts, the internal structure of these self-assembled cages remains ill characterized. We used fluorescent probe molecules, pyrene butyric acid (PBA), as guests in C-hexylpyrogallol[4]arene capsules to relay information about the chemical environment on the interior of the assemblies. Spectroscopic and single-crystal x-ray diffraction studies show that, in both solution and the solid state, the host can encapsulate two PBA guests and keep them well separated through specific interactions with the capsule walls.

The micellar liquid chromatographic (MLC) separations of polycyclic aromatic hydrocarbons (PAHs) were optimized for three micellar systems, cetyltrimethylammonium chloride (CTAC), dodecyltrimethylammonium chloride (DTAC), and sodium dodecylsulfate (SDS), with 1-pentanol as the only organic additive. A difference in the separation was observed between CTAC and SDS/DTAC. Under each optimized separation conditions, CTAC-modified mobile phase provides the least desirable separation, which is attributed to its longer carbon tail (C16 vs. C12). In addition to 1-pentanol, the main organic additive, a second organic additive (3% 1-propanol) in the micelle-modified mobile phase was found to enhance the resolution of PAH chromatographic peaks. However, the extent of the enhancement varies for the different micellar systems, with the greatest resolution improvement seen for CTAC, and little effect for shorter-tail SDS and DTAC. This study shows the potential use of second organic additive (1-propanol), to the main nonpolar additive (1-pentanol), in facilitating the MLC separation of larger nonpolar compounds.

The cyclin-dependent kinase inhibitors p27Kip1 and p21WAF1/Cip1 play important roles in cell-cycle regulation. Although alterations of these genes have been linked to tumorigenesis of several human carcinomas, their involvement in head and neck squamous tumorigenesis is rarely investigated. To determine the role of these genes in the evolution of squamous carcinoma of the head and neck we evaluated their protein expression by immunohistochemistry in non-dysplastic squamous epithelium, premalignant lesions and oral squamous carcinomas. The p53 gene and Ki-67 expressions were correlated with traditional clinicopathologic variables. Our study shows that in histologically non-dysplastic squamous epithelium, p27 expression was noted mainly in superficial differentiated cells, whereas p21, p53 and Ki-67 staining was observed in basal and suprabasal cells. In dysplasia, divergent expression between p27 and p21 was observed: p27 precipitously decreased and p21, p53, and Ki-67 increased with histologic progression. In squamous carcinomas, p27 was mainly expressed in well differentiated tumor cell nests, while the expressions of p21, p53, and Ki-67 were variable in the poorly differentiated tumor areas. A significant inverse relationship between p27 expression and those of p21, p53, and Ki-67 was observed, but no significant association between any of these markers and clinicopathologic factors was noted in this cohort. Our study indicates that: i) down-regulation of p27 and up-regulation of p21 are associated with early progression of HNSC, ii) p21 expression correlates positively with proliferation while p27 correlates positively with cell differentiation and iii) concurrent p27 and p21 expression analysis may allow for better assessment of HNSC progression.

Heart disease is the primary cause of on-duty deaths in firefighters, but little is known about their lipid profile. We evaluated the lipid profile in relation to other cardiovascular disease risk factors in 321 firefighters at a baseline examination. Prospective comparisons were performed for 285 firefighters, who were enrolled in a statewide medical surveillance program, and had complete follow-up data for 4 years. The average cholesterol level in firefighters declined from 224 mg/dL at baseline (1996-1997) to 214 mg/dL at the follow-up examination (P < 0.0001). Conversely, both obesity (body mass index > or = 30; 34% versus 40%, P = 0.008) and triglycerides (> or = 200 mg/dL; 27% versus 35%, P = 0.047) increased over time. The proportion of firefighters taking lipid-lowering medications increased from 3% at baseline to 12% at follow-up (P < 0.0001). Cholesterol levels declined significantly, and treatment rates for elevated cholesterol increased over time. Despite repeated examinations, a considerable number of firefighters had persistently elevated cholesterol, and only a minority were receiving adequate treatment.

The first use of pyridinium chloride (PC), as a selective fluorescence quenching agent of alternant polycyclic aromatic hydrocarbons (PAHs), under HPLC separation conditions is reported. PC was found to be superior to nitromethane, the only reported PAH selective quencher used in HPLC. The mobile phase addition of 0.03 M PC greatly simplifies the observed fluorescence-detected chromatograms for complex PAH mixtures, facilitating PAH identification. Stern-Volmer quenching constants (K(sv)) for PAHs were calculated from the chromatograms obtained under isocratic and gradient conditions and found to be similar. The K(sv) values were shown to be useful in establishing peak purity.

We evaluated the association between hypertension and changes in employment status in 334 hazardous materials firefighters. Firefighters were categorized by blood pressure (BP) at baseline (1996 or 1997) and subsequent follow-up examinations (1997, 1998, and 1999). They were followed up for a maximum of 4 years for possible adverse outcomes (death, placement on "injured-on-duty" status, termination of duty, resignation, retirement, or incident cardiovascular disease). In several analytic models, we found that firefighters with stage II hypertension (BP > or = 160/100 mm Hg) were consistently 2 to 3 times more likely to experience an adverse outcome compared with those with normal BP. Cox proportional-hazards regression was used to adjust for age, body mass index, smoking, cholesterol, and antihypertensive medication. In these models, the hazard ratio for stage II hypertension was 3.2 (95% confidence interval [CI], 1.50 to 7.04, P = 0.003) and for untreated stage II hypertension, it was 4.6 (95% CI, 2.08 to 10.11, P = 0.0002). Firefighters with a BP > or = 160/100 mm Hg should receive further evaluation and demonstrate improved BP control before being determined fit for duty.

While it is generally accepted that water hardness affects copper toxicity, the major ions that contribute to water hardness (calcium [Ca] and magnesium [Mg]) may affect copper toxicity differently. This is important because the Ca:Mg ratio in standard laboratory-reconstituted waters often differs from the ratio in natural surface waters. Copper toxicity was assessed for five different aquatic species: rainbow trout (RBT), fathead minnow (FHM), Ceriodaphnia dubia, Daphnia magna, and an amphipod (Gammarus sp.) under different Ca:Mg ratios (4:0, 3:1, 1:1, 1:3, and 1:4 mass basis) at a common hardness (180 mg/L as CaCO3) and alkalinity (120 mg/L as CaCO3). Copper toxicity increased at lower Ca:Mg ratios for RBT but increased at higher Ca:Mg ratios for D. magna. Fathead minnows (<24 h old) were more sensitive to copper in 1:1 Ca:Mg waters compared to 3:1 Ca:Mg waters. The toxicity of copper did not vary under different Ca:Mg ratios for Gammarus sp., C. dubia, and 28-d-old FHM. The effect of Ca:Mg ratios on copper toxicity changed for D. magna in softer water (90 mg/L as CaCO3) compared with hard water studies.

The physical and chemical properties of PPI dendrimers' interior were investigated using the fluorescent, solvatochromic probe phenol blue. In aqueous solutions of each generation studied, two discrete dye populations were clearly observed. PPI dendrimers were shown to form a tight, nonpolar association with the vast majority of available dye, within the dendrimer interior, near the core. In the steady-state fluorescence emission spectra, a microenvironment of decreasing polarity in increasingly larger-generation PPI dendrimers (up to G3) was seen for the associated probe. Each of the remaining larger-generation dendrimers provided a microenvironment of essentially equal polarity. Fluorescence anisotropy values for phenol blue in the PPI dendrimers demonstrated the dye's sensitivity to the changing molecular volumes of the dendrimer generations. Model compounds that mimicked PPI's surface groups and branching moieties were used to better define the associated dye's location. The mimics further confirmed that phenol blue was associated inside the dendrimer, where it did not interact with the dendrimer surface groups. The comparison of amine-terminated PPI and PAMAM dendrimers clearly demonstrated the effects of their structural differences and the ability of phenol blue to have sensed those differences, including the initiator core length, branching unit length, and branching unit chemical composition.

The ability of pyridinium chloride (PC) to selectively quench alternant as opposed to nonaltemant polycyclic aromatic hydrocarbons (PAHs) in organized media is examined. PC was previously shown to be a selective quenching agent of alternant PAHs in neat polar solvents. Carboxylate-terminated poly(amido) amine (PAMAM-CT) dendrimers and anionic surfactants--sodium dodecanoate (SD), sodium octanoate (SO), and sodium dodecylsulfate (SDS)--were chosen as the solubilizing media for this study. Selective quenching of alternant PAHs is observed in the presence of the SDS and SO micelles. However, the extent of PAH quenching in SO is significantly reduced compared to PAHs dissolved in either water or SDS micelles. In the case of the smaller generation 4.5 (G4.5) PAMAM-CT dendrimers, PC was prevented from quenching both alternant and nonalternant PAHs to any appreciable extent. The dendrimer is able to "protect" the PAHs from the PC quencher that resides at the dendrimer surface. Both, SD and G5.5 PAMAM-CT precipitated out of solution with the addition of PC. Differences between traditional micelles and "unimolecular micelle" dendrimers were also examined. These studies further confirm that the PAHs did not reside in the "analogous" palisade region of the dendrimers as they do in micelles. The PAHs must reside in the outermost branches of the dendrimer, but sufficiently far enough away from the charged surface groups, where PC associated, to prevent fluorescence quenching. This work further illustrates the differences between "unimolecular micelle" dendrimers and traditional micelles.

Pyridinium chloride (PC) is examined as a selective, fluorescence quenching agent for alternant as opposed to nonalternant polycyclic aromatic hydrocarbons (PAHs) in two polar solvents - water and acetonitrile. Nine alternant and 13 nonalternant PAHs were dissolved in water and acetonitrile and a total of 0.2 M of pyridinium chloride was added. The resulting change in fluorescence intensity was observed and reported as the Stern-Volmer quenching constant. Results show that PC is a selective quencher in both polar solvents. It selectively quenches the fluorescence emission intensity of alternant PAHs while leaving the nonalternant PAH fluorescence emission virtually unchanged. These results agree with the selective quenching behavior seen for PC surfactant analogs, cetylpyridinium chloride (CPC) and dodecylpyridinium chloride (DDPC). Furthermore, these results illustrate that the presence of a surfactant or micelle is not a requirement for selective quenching. The selective quencher PC is applicable to situations where a surfactant is not desirable or soluble.

Genomic imprinting is an inherited epigenetic phenomenon that results in parental-origin-specific gene expression in somatic cells. Relaxation or loss of this feature in certain genes has been demonstrated in several pediatric and adult neoplasms, suggesting an association with tumorigenesis. We analysed 64 primary untreated head and neck squamous carcinoma for the loss of imprinting in the IGF2 and H19 genes to determine the implications of this alteration in the development and progression of these tumors. Forty-nine (77%) of the 64 tumors were informative for imprinting analyses of these genes. IGF2 and H19 were imprinted in all normal squamous epithelium examined. Twelve (37.5%) of 32 tumors informative for H19 and 11 (40.7%) of 27 tumors informative for IGF2 manifested loss of imprinting. Ten tumors were informative for both genes, of which four maintained the constitutional imprinting and six showed loss of imprinting at either H19 or IGF2. These data suggest that loss of imprinting at the IGF2 and H19 loci play a role in the oncogenesis of head and neck carcinoma.

Cyclin D1, p16, and Rb genes play a critical role in the regulation of the G1-S transition of the cell cycle and are frequently altered in several neoplastic entities. Analysis of the protein products of these genes by molecular and immunohistochemical methods provides information on their functional status and allows for the phenotypic evaluation of tumor cells. We performed Western blotting and immunohistochemical analysis on tissues from 35 primary oral and laryngeal squamous carcinoma specimens with previous molecular analysis of the p16 gene and correlated the results with relevant clinicopathologic factors. Our study shows significant concordance between Western blotting and immunostaining results for cyclin D1 (P = .01), p16 proteins (P = .01), and Rb (P = .04). Heterogeneous staining of tumor cells and the positivity of non-neoplastic host elements for Rb by immunohistochemistry contributed to the discrepancy noted in some tumors by Western blotting. Significant reciprocal relationship between p16 and Rb proteins was observed (P < .001); in most tumors, absence of p16 (89%) and detectable Rb (94%) proteins were found. Two tumors had negative cyclin D1 expression, and one third overexpressed this protein. There was a lack of correlation between cyclin D1 overexpression and the clinicopathologic factors studied. Our results indicate that the absence of p16 in most of these tumors may constitute an early tumorigenic event and that the loss of the Rb function plays a minor role in HNSC.

Background: The Mammography Quality Standards Act (MQSA) became effective October 1, 1994, and requires all mammography facilities to meet quality standards as promulgated by the Food and Drug Administration (FDA). The FDA undertook an assessment of the MQSA federal certification requirements on the availability of mammography facilities., Methods: A survey of states on mammography facility closures between October 1, 1993, and October 1, 1994, was conducted. MapInfo software was used to link zip codes to demographic databases. The characteristics of closed facilities were compared to certified facilities as of December 15, 1994., Results: A total of 369 facilities (3.5%) had closed. This closure rate was comparable to previous years' rates (2.5-10%). As of December 15, 1994, 10,142 certified facilities were operating. Relative to their distribution in the United States, closures in rural areas were proportional, but there were more facility closures in the minority areas and in poverty areas. However, the relative distributions of facilities to these areas' populations were unchanged., Conclusions: Impact on facility availability has been minimal., (Copyright 1998 American Health Foundation and Academic Press.)

Dyes of several classes were investigated as candidates for use in a multiplex, four-decay fluorescence detection scheme for DNA sequencing. The dyes include nitrobenzofuran dyes, rhodamine dyes, fluorescein dyes, cyanine dyes, Nile Red, and BODIPY dyes. Based on the results of fluorescence spectral and lifetime studies, an initial set of four dyes was selected for further study: NBD-aminohexanoic acid (NBD-HA, r = 1.1 ns), tetramethyl-rhodamine, methyl ester (r = 2.2 ns), rhodamine green (r = 4.3 ns), and BODIPY 505/515 (r = 5.9 ns). Limits of lifetime detection of the four dyes were investigated, and lifetime resolution was demonstrated for mixtures of the free dyes in batch solution. Lifetime of dye-labeled DNA primers also were determined in batch solution and detected on-the-fly in capillary electrophoresis (CE). Conjugation of the dyes to DNA improved the resolution of their individual lifetimes in mixtures in batch measurements. When attached to the primer, tetramethyl-rhodamine exhibited biexponential decay with a dominant lifetime of 3.8 ns, making it unsuitable for four-decay sequencing. Contact with the CE gel lengthened the lifetime of NBD-HA-labeled primer from 1.3 to 2.1 ns but did not affect the lifetimes of the other dyes. Lifetime detectability of labeled primers at individual points along an electrophoretic peak in the attomole range.

Five catching methods were compared in terms of their effect on the proportion of battery hens which had bones broken when they were removed from battery cages. In addition the effect of tier, lighting intensity during lay and lighting intensity during handling on the prevalence of fractures at catching and on old fractures which occurred during lay was evaluated. Catching and removing hens by one leg from the cages resulted in 11 to 14 per cent of the birds acquiring a broken bone, whereas catching and removing each bird by two legs resulted in 5 per cent of the birds acquiring a freshly broken bone. Removing more than one bird at a time from the cage tended to cause more skeletal damage than removing them individually, and incorporating a wooden breast support slide over the feed trough had no effect on the prevalence of broken bones. Catching birds in the top tier of a three-tiered battery unit was more difficult than for the middle or bottom tiers. When the light intensity at catching was the same as that during lay birds were more difficult to catch than when the light intensity was changed, but the effects were insufficient to affect the prevalence of damage to the skeleton.

Five trials were conducted in which six methods of picking end of lay hens from battery cages were compared with three people performing the picking. Pulling the birds over a breast support slide, which created a smooth surface over the feeding trough, did not affect the prevalence of broken bones. In one trial, picking birds by one leg resulted in about three times more fractured bones than picking by two legs. This effect, however, was not evident in three other trials, suggesting that the advantage from two leg picking would only exist with some pickers or some flocks. Pulling more than one bird at a time by one leg through the cage entrance was associated with more skeletal damage than pulling birds individually by two legs. Picking the birds by one leg was easier to perform than picking by two legs.

Analysis of data in terms of the sum of two rectangular hyperbolas is frequently required in solute uptake studies. Four methods for such analysis have been compared. Three are based on least-squares fitting whereas the fourth (partition method I) is an extension of a single hyperbola fitting procedure based on non-parametric statistics. The four methods were tested using data sets which had been generated with two primary types of random, normal error in the dependent variable: one of constant error variance and the other of constant coefficient of variation. The methods were tested on further data sets which were obtained by incorporating single 10% bias errors at different positions in the original two sets. Partition method I consistently gave good estimates for the four parameters defining the double hyperbola and was highly insensitive to the bias errors. The least-squares procedures performed well under conditions satisfying the least-squares assumptions regarding error distribution, but frequently gave poor estimates when these assumptions did not hold. Our conclusion is that in view of the errors inherent in many solute uptake experiments it would usually be preferable to analyse data by a method such as partition method I rather than to rely on a least-squares procedure.