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In the last few years, halogen bonds have been exploited in a variety of research areas both in the solid state and in solution. Nevertheless, several factors make formation and detection of halogen bonds in solution challenging. Moreover, to date, few chiral molecules containing electrophilic halogens as recognition sites have been reported. Recently, we described the first series of halogen-bond-driven enantioseparations performed on cellulose tris(3,5-dimethylphenylcarbamate) by high-performance liquid chromatography. Herein the performances of amylose tris(3,5-dimethylphenylcarbamate) as halogen bond acceptor were also investigated and compared with respect to cellulose tris(3,5-dimethylphenylcarbamate). With the aim to explore the effect of polysaccharide backbone on the enantioseparations, the thermodynamic parameters governing the halogen-dependent enantioseparations on both cellulose and amylose polymers were determined by a study at variable temperature and compared. Molecular dynamics were performed to model the halogen bond in polysaccharide-analyte complexes. Chiral halogenated 4,4'-bipyridines were used as test compounds (halogen bond donors). On this basis, a practical method for detection of stereoselective halogen bonds in solution was developed, which is based on the unprecedented use of high-performance liquid chromatography as technical tool with polysaccharide polymers as molecular probes (halogen bond acceptors). The analytical strategy showed higher sensitivity for the detection of weak halogen bonds., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: To provide further information on the clinical and pathological prognostic factors in triple-negative breast cancer (TNBC), for which limited and inconsistent data are available., Methods: Pathological characteristics and clinical records of 841 TNBCs diagnosed between 1994 and 2015 in four major oncologic centers from Sardinia, Italy, were reviewed. Multivariate hazard ratios (HRs) for mortality and recurrence according to various clinicopathological factors were estimated using Cox proportional hazards models., Results: After a mean follow-up of 4.3 years, 275 (33.3%) TNBC patients had a progression of the disease and 170 (20.2%) died. After allowance for study center, age at diagnosis, and various clinicopathological factors, all components of the TNM staging system were identified as significant independent prognostic factors for TNBC mortality. The HRs were 3.13, 9.65, and 29.0, for stage II, III and IV, respectively, vs stage I. Necrosis and Ki-67 > 16% were also associated with increased mortality (HR: 1.61 and 1.99, respectively). Patients with tumor histotypes other than ductal invasive/lobular carcinomas had a more favorable prognosis (HR: 0.40 vs ductal invasive carcinoma). No significant associations with mortality were found for histologic grade, tumor infiltrating lymphocytes, and lymphovascular invasion. Among lymph node positive TNBCs, lymph node ratio appeared to be a stronger predictor of mortality than pathological lymph nodes stage (HR: 0.80 for pN3 vs pN1, and 3.05 for >0.65 vs <0.21 lymph node ratio), respectively. Consistent results were observed for cancer recurrence, except for Ki-67 and necrosis that were not found to be significant predictors for recurrence., Conclusions: This uniquely large study of TNBC patients provides further evidence that, besides tumor stage at diagnosis, lymph node ratio among lymph node positive tumors is an additional relevant predictor of survival and tumor recurrence, while Ki-67 seems to be predictive of mortality, but not of recurrence.

The term Atropisomerism defines a type of enantiomerism that arises from hindered rotation around an axis that makes two rotational isomers enantiomers. Atropisomeric compounds are present in nature, being important building blocks of many biologically active compounds. Atropisomers have been extensively studied in environmental and toxicological chemistry and, in particular, separating them has become a need in specific fields as organic synthesis and pharmaceutical research. High-performance LC has been fruitfully applied in this context, and despite HPLC separation on chiral stationary phase is considered as mature technology nowadays, in the last years several advancements and applications contributed to study compounds where axial chirality is of utmost importance. Moreover, dynamic chromatography has been exploited as a versatile tool for kinetic studies of systems with slow internal motion gaining essential information on their stereodynamic behavior. On this basis, current topics and trends in liquid-phase chromatography enantioseparation of atropisomers are presented herein with specific focus on new representative applications with HPLC, covering years 2010-2016. Some examples concerning supercritical fluid chromatography applications are also reported. This review aims to provide the reader with a modern overview of the field to highlight the renewed interest toward the chemistry of molecules with atropisomeric properties. A systematic compilation of all published literature has not been attempted., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

OBJECTIVE During the last 3 decades, robotic technology has rapidly spread across several surgical fields due to the continuous evolution of its versatility, stability, dexterity, and haptic properties. Neurosurgery pioneered the development of robotics, with the aim of improving the quality of several procedures requiring a high degree of accuracy and safety. Moreover, robot-guided approaches are of special interest in pediatric patients, who often have altered anatomy and challenging relationships between the diseased and eloquent structures. Nevertheless, the use of robots has been rarely reported in children. In this work, the authors describe their experience using the ROSA device (Robotized Stereotactic Assistant) in the neurosurgical management of a pediatric population. METHODS Between 2011 and 2016, 116 children underwent ROSA-assisted procedures for a variety of diseases (epilepsy, brain tumors, intra- or extraventricular and tumor cysts, obstructive hydrocephalus, and movement and behavioral disorders). Each patient received accurate preoperative planning of optimal trajectories, intraoperative frameless registration, surgical treatment using specific instruments held by the robotic arm, and postoperative CT or MR imaging. RESULTS The authors performed 128 consecutive surgeries, including implantation of 386 electrodes for stereo-electroencephalography (36 procedures), neuroendoscopy (42 procedures), stereotactic biopsy (26 procedures), pallidotomy (12 procedures), shunt placement (6 procedures), deep brain stimulation procedures (3 procedures), and stereotactic cyst aspiration (3 procedures). For each procedure, the authors analyzed and discussed accuracy, timing, and complications. CONCLUSIONS To the best their knowledge, the authors present the largest reported series of pediatric neurosurgical cases assisted by robotic support. The ROSA system provided improved safety and feasibility of minimally invasive approaches, thus optimizing the surgical result, while minimizing postoperative morbidity.

Introduction: Intrameatal cochleovestibular neurovascular conflict is a rare condition with specific clinical and therapeutic implications. Although surgery is commonly indicated in other neurovascular conflicts, for this subset of patients there is little evidence to guide treatment decisions. Moving from a case description, we performed a review of the literature on this topic to systematically present the best available evidence to guide clinical decisions., Methods: We performed a literature review on reported cases of surgically treated intrameatal anterior inferior cerebellar artery (AICA)-cochleovestibular nerve neurovascular conflict, analyzing preoperative clinical data, surgical techniques, and outcomes. We analyzed the levels of evidence using the King's College guidelines., Discussion: We found 35 studies of neurovascular compression of the cochleovestibular nerve by AICA for 536 patients operated on to resolve their neurovascular conflict. Only 4 of these studies describe intrameatal AICA neurovascular conflicts, for 9 cases, including our own. Tinnitus was the most frequent symptom (9/9), followed by vertigo (2/9). Our case was the only one showing unilateral hearing loss. Surgery consisted of microsurgical mobilization of the AICA loop performed through a retrosigmoid craniotomy. Tinnitus and vertigo resolved after surgery in all cases, whereas hearing loss did not improve after surgery., Conclusions: Surgical treatment offers the best results for tinnitus and vertigo, but it seems to have no effect on hearing loss, not even at long-term follow-up. Microvascular decompression should be proposed to intrameatal symptomatic patients before the onset of hearing loss., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Although the halogen bond (XB) has been so far mainly studied in silico and in the solid state, its potential impact in solution is yet to be fully understood. In this study, we describe the first systematic investigation on the halogen bond in solvated environment by high-performance liquid chromatography (HPLC). Thirty three atropisomeric polyhalogenated-4,4'-bipyridines (HBipys), containing Cl, Br and I as substituents, were selected and used as potential XB donors (XBDs) on two cellulose-based chiral stationary phases (CSPs) containing potential XB acceptors (XBAs). The impact of the halogens on the enantiodiscrimination mechanism was investigated and iodine showed a pivotal role on the enantioseparation in non-polar medium. Electrostatic potentials (EPs) were computed to understand the electrostatic component of CSP-analyte interaction. Moreover, van't Hoff studies for ten HBipys were performed and the thermodynamic parameters governing the halogen-dependent enantioseparations are discussed. Finally, a molecular dynamic (MD) simulation is proposed to model halogen bond in polysaccharide-analyte complexes by inclusion of a charged extra point to represent the positive 'σ-hole' on the halogen atom. On the basis of both experimental results and theoretical data, we have profiled the halogen bond as a chemo-, regio-, site- and stereoselective interaction which can work in HPLC environment besides other known interactions based on the complementarity between selector and selectand., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective: Specific bioelectrical impedance vector analysis (spBIVA) is a recently proposed technique for the analysis of body composition. The aim of this study was to apply spBIVA to a sample of Italian and Spanish young adults and to define the new bioelectrical references for this Western Mediterranean population., Methods: A sample of 440 individuals (220 from Italy, 220 from Spain; 213 men, 227 women) aged 18-30 years was considered. Anthropometric (height, weight, relaxed upper arm, waist, and calf girths) and bioelectrical (resistance, reactance; 50 kHz, 800 μA) measurements were taken. In order to verify the need for new references, specific bioelectrical values were compared to the reference values for U.S. adults and Italian elderly by tolerance ellipses and Student's t test., Results: The mean specific bioelectrical values (resistivity, Rsp, and reactivity, Xcsp, Ohm·cm) were: Rsp (332.7 ± 41.7 Ω·cm), Xcsp (44.4 ± 6.8 Ω·cm), Zsp (335.6 ± 41.9 Ω·cm) and phase (7.6 ± 0.8°) in men; Rsp (388.6 ± 60 Ω·cm), Xcsp (43.7 ± 7.5 Ω·cm), Zsp (391.0 ± 60.3 Ω·cm) and phase (6.4 ± 0.7°) in women. Italo-Spanish bioelectrical vectors were mainly distributed (>90%) in the lower part of the tolerance ellipses for U.S. young adults, due to a shorter impedance (P < 0.001), indicative of a lower percent fat mass. Compared to Italian elders, they were mainly located in the left side (>90%), due to a higher phase (P < 0.001), indicative of higher body cell mass., Conclusions: These population and age-related differences indicate the need for new specific tolerance ellipses that can be used as references for assessing body composition in young adults from Western Mediterranean populations., (© 2015 Wiley Periodicals, Inc.)

Kaposi sarcoma is a tumour caused by human herpes virus 8, also known as Kaposi sarcoma-associated herpes virus. It usually affects the skin and oral mucosa; however, it can also sometimes affect the lungs, the liver, the stomach, the bowel, and lymph nodes. Several body sites may be affected simultaneously. The involvement of the tonsils is rare. We described an isolated localization of Kaposi's sarcoma of the right tonsil in a HIV-positive patient.

The last frontier in the chiral stationary phases (CSPs) field for chromatography enantioseparations is represented by homochiral metal-organic frameworks (MOFs), a class of organic-inorganic hybrid materials built from metal-connecting nodes and organic-bridging ligands. The modular nature of these materials allows to design focused structures by combining properly metal, organic ligands and rigid polytopic spacers. Intriguingly, chiral ligands introduce molecular chirality in the MOF-network as well as homochirality in the secondary structure of materials (such as homohelicity) producing homochiral nets in a manner mimicking biopolymers (proteins, polysaccharides) which are characterized by a definite helical sense associated with the chirality of their building blocks (amino acids or sugars). Nowadays, robust and flexible materials characterized by high porosity and surface area became available by using preparative procedures typical of the so-called reticular synthesis. This review focuses on recent developments in the synthesis and applications of homochiral MOFs as supports for chromatography enantioseparations. Indeed, despite this field is in its infancy, interesting results have been produced and a critical overview of the 12 reported applications for gas chromatography (GC) and high-performance liquid chromatography (HPLC) can orient the reader approaching the field. Mechanistic aspects are shortly discussed and a view regarding future trends in this field is provided., (Copyright © 2014 Elsevier B.V. All rights reserved.)

An investigation on the high-performance liquid chromatography enantioseparation of 12 polyhalogenated 4,4'-bipyridines on polysaccharide-based chiral stationary phases is described. The overall study was directed toward the generation of efficient separations in order to obtain pure atropisomers that will serve as ligands for building homochiral metal organic frameworks. Four coated columns--namely, Lux Cellulose-1, Lux Cellulose-2, Lux Cellulose-4, and Lux Amylose-2--and two immobilized columns--namely, Chiralpak IC and IA--were used under normal, polar organic, and reversed-phase elution modes. Moreover, Chiralcel OJ was considered under normal-phase and polar organic conditions. The effect of the chiral selector and mobile phase composition on the enantioseparation, the enantiomer elution order and the beneficial effect of nonstandard solvents were studied. The effect of water in the mobile phase on the enantioselectivity and retention was investigated and retention profiles typical of hydrophilic interaction liquid chromatography were observed. Interesting phenomena of solvent-induced enantiomer elution order reversal occurred under normal-phase mode. All the considered 4,4'-bipyridines were enantioseparated at the multimilligram level., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Purpose: The aim of this systematic review was to assess the efficacy of heparin flushing in the lock of central venous catheters., Methods: We searched MEDLINE and CINAHL databases. Eligible studies were randomized controlled trials evaluating the use of heparin versus normal saline or other solution in the flushing of central catheter among adult patients. No language restrictions were applied. Two reviewers independently screened titles and abstracts in order to identify relevant publications. The same two reviewers retrieved and evaluated full texts. Parameter estimates regarding catheter occlusion were pooled using network meta-analysis with Bayesian hierarchical modeling., Results: We identified 462 references. Eight studies were included. There was no evidence that heparin was more effective than normal saline in reducing occlusions. It was unclear whether urokinase and lepirudin were more effective than heparin in reducing occlusions. Vitamin C solution does not appear to prolong catheter patency., Conclusions: There is no evidence of a different effectiveness between heparin flushing and normal saline or other solutions in reducing catheter occlusions. Due to the little and inconclusive evidence available in this field, further studies might be necessary.

Starting from the high-performance liquid chromatography (HPLC) enantioseparation data collected by using twelve polyhalogenated 2,2'-dichloro-3-substituted-5,5'-dihalo-4,4'-bipyridines as test probes on seven polysaccharide-based chiral stationary phases (CSPs) under multimodal elution, the impact of substitution pattern, shape and electronic properties of the molecules on the separation behaviour was investigated through the evaluation of the chromatographic parameters (k, α, Rs) and molecular properties determined by means of quantum chemistry calculations. The computational/chromatographic screening furnished relevant structure-chromatographic behaviour relationships and some molecular interactions involved in the chiral discrimination process could be identified. In particular, a halogen bonding interaction (I(.)O) could reasonably explain the high enantioseparation (α=1.80, Rs=8.2) observed for the 2,2'-dichloro-3,5'-diiodo-5-bromo-4,4'-bipyridine on Lux Cellulose-1. To the best of our knowledge, this is the first report supporting the involvement of a stereoselective halogen bonding interaction in polysaccharide-based CSPs. Moreover, having at disposal a sufficient set of data, the unknown absolute configurations of the eluted enantiomers of 3-methyl-, 3-thiomethyl- and 3-diphenylphosphinoyl-2,2'-dichloro-5,5'-dibromo-4,4'-bipyridines could be deduced by chromatographic correlation with the enantiomer elution order (EEO) of the related compounds of known absolute configuration., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We employed color Doppler score as an innovative approach for the prenatal diagnosis and monitoring of a large placental chorioangioma case diagnosed at 26 weeks and the subjective semiquantitative assessment of the vascularization. The blood flow was assessed by a color Doppler score based on the intensity of the color signal with the following value ranges: (1) no flow, (2) minimal flow, (3) moderate flow, and (4) high vascular flow. Weekly examinations were programmed. Initially, a color Doppler score 3 was assigned, remaining unchanged at the following two exams and decreasing to Score 2 in the following 2 exams and to Score 1 thereafter. The ultrasonographic scan showed an increase of the mass size at the second and third exams and was followed by an arrest of the growth persisting for the rest of the pregnancy. Some hyperechogenic spots inside the mass appeared at the end. Expectant management was opted for, and the delivery was at 39, 2 weeks and maternal and fetal outcomes were favourable. The color Doppler score employed for assessment of vascularization in successive examinations proved to be an important tool for the prediction of the chorioangioma involution, and this new approach of monitoring allowed effective surveillance and successful tailored management.

Lithiation of the achiral tetrahalogenated 4,4'-bipyridine 1 with alkyllithiums was investigated. n-BuLi was found to induce either the chlorine-directed deprotolithiation reaction alone or with a concomitant halogen-lithium exchange furnishing after iodine trapping chiral 4,4'-bipyridines 2 and 6, respectively. The role of n-BuLi in the deprotolithiation process of 1 was elucidated on the basis of isolated secondary derivatives. After deprotolithiation, the lithiated species could be trapped by different electrophiles such as MeI, TMSCl, MeSSMe, R3SnCl (R = Me or n-Bu), and PPh2Cl. Moreover, 4,4'-bipyridine 2 was submitted to cross-coupling reactions (Suzuki and Sonogashira) which occurred selectively at the carbon-iodine bond. All compounds of this new family of atropisomeric 4,4'-bipyridines were separated by chiral HPLC (high-performance liquid chromatography), and the absolute configurations of obtained enantiomers were mainly assigned by XRD (X-ray diffraction) using anomalous dispersion.

Background: In a previous report, we described the in vitro and in vivo antiproliferative and proapoptotic activity of a hydroxylated biphenyl (D6), a structural analogue of curcumin, on malignant melanoma and neuroblastoma tumours. In this paper, we investigated the molecular changes induced by such a compound, underlying cell growth arrest and apoptosis in melanoma cells., Results: To shed light on the mechanisms of action of D6, we firstly demonstrated its quick cellular uptake and subsequent block of cell cycle in G2/M phase transition. A gene expression profile analysis of D6-treated melanoma cells and fibroblasts was then carried out on high density microarrays, to assess gene expression changes induced by this compound. The expression profile study evidenced both an induction of stress response pathways and a modulation of cell growth regulation mechanisms. In particular, our data suggest that the antiproliferative and proapoptotic activities of D6 in melanoma could be partially driven by up-regulation of the p53 signalling pathways as well as by down-regulation of the PI3K/Akt and NF-kB pathways. Modulation of gene expression due to D6 treatment was verified by western blot analysis for single proteins of interest, confirming the results from the gene expression profile analysis., Conclusions: Our findings contribute to the understanding of the mechanisms of action of D6, through a comprehensive description of the molecular changes induced by this compound at the gene expression level, in agreement with the previously reported anti-tumour effects on melanoma cells.

Background: In malignant melanoma (MM), overexpression of αvβ3 integrin is linked to a more metastatic phenotype. Development of anti-αvβ3 agents able to counteract melanoma progression would be helpful for disease treatment. A new selective ligand of αvβ3, RGDechi-hCit, has anti-angiogenic properties against endothelial cells in animal angiogenesis models. The aim of this study was to evaluate the in vitro effects of the RGDechi-hCit peptide on MM cell lines., Materials and Methods: Cytofluorimetric analysis characterized the cell surface expression of αvβ3 integrin on seven MM cell lines: A375, WM266-4, SK-Mel-28, Sbcl2, LB24Dagi, PR-Mel and PNP-Mel. Cell proliferation, adhesion, and migration assays were carried out using the αvβ3-antagonist RGDechi-hCit., Results: Proliferation was not significantly inhibited by RGDechi-hCit, although striking morphological changes were detected in MM cell lines highly expressing αvβ3. Conversely, assays on fibronectin-coated plates showed a significant RGDechi-hCit dose-dependent inhibitory effect on both adhesion and migration., Conclusion: The data demonstrate anti-adhesion and anti-migration, but not antiproliferative, activities of RGDechi-hCit against MM cells.

The high performance liquid chromatography (HPLC) enantioseparation of eleven atropisomeric 4,4'-bipyridines was performed in the normal and polar organic phase mode using three cellulose-based chiral stationary phases (CSPs), namely Lux Cellulose-1, Lux Cellulose-2, Lux Cellulose-4, and two amylose-based CSPs, Chiralpak AD-H and Lux Amylose-2. n-Hexane/2-propanol mixtures and pure ethanol were employed as mobile phases. The combined use of Chiralpak AD-H and Lux Cellulose-2 allowed to enantioseparate all the considered bipyridines. Ten bipyridines were enantioseparated at the multimilligram level allowing the elution sequence determination of the enantiomers as well as their future use for the preparation of homochiral metal organic frameworks (MOFs). Moreover, the performance of the CSPs regarding the same bipyridine was different and dependent on the backbone as well as on the side chain of the polymer. The impact of substitution pattern, shape and electronic properties of the molecules on the separation behavior was investigated through the evaluation of retention factors (k), separation factors (α), resolution (R(s)) and molecular properties determined using density functional theory (DFT) calculations. In this regard, the substituents at the 3,3',5,5' positions of the 4,4'-bipyridyl rings exhibited a pivotal role on the enantioseparation., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A chiral polyhalogenated 4,4'-bipyridine derivative is described allowing an easy access to a new family of chiral 4,4'-bipyridines by site-selective cross-coupling reactions. The absolute configurations of all the HPLC separated enantiomers were determined by X-ray diffraction and electronic circular dichroism coupled with time-dependent density functional theory calculations.

Objective: This study aimed to evaluate the presence of pressure-painful scalp arteries in children and adolescents with migraine., Materials and Methods: Pressure-painful points on scalp arteries were searched in 130 consecutive children (6-12 years old) and adolescents (>13 years old) affected with migraine, 89 females and 41 males, and in 40 age-matched controls., Results: In the absence of a migraine episode, we examined 76 patients: 54 (71.1%) reported one or more pressure-painful arteries and 22 reported none. Of the 40 controls, pressure-painful arteries were present in 11, with a highly significant difference (p < 0.0001). During a migraine attack, of the 54 patients examined, 43 (79.6 %) reported one or more pressure-painful arteries and 11 reported none. The arteries most frequently painful were the frontal branch and the superficial temporal artery., Conclusions: Scalp arteries are frequently painful on pressure in children and adolescents with migraine, both in the absence of and during a migraine attack. Painful arteries suggest hypersensitivity of periarterial nociceptive afferents.

Background: Sharing the common neuroectodermal origin, melanoma and neuroblastoma are tumors widely diffused among adult and children, respectively. Clinical prognosis of aggressive neuroectodermal cancers remains dismal, therefore the search for novel therapies against such tumors is warranted. Curcumin is a phytochemical compound widely studied for its antioxidant, anti-inflammatory and anti-cancer properties. Recently, we have synthesized and tested in vitro various curcumin-related compounds in order to select new anti-tumor agents displaying stronger and selective growth inhibition activity on neuroectodermal tumors., Results: In this work, we have demonstrated that the new alpha,beta-unsaturated ketone D6 was more effective in inhibiting tumor cells growth when compared to curcumin. Normal fibroblasts proliferation was not affected by this treatment. Clonogenic assay showed a significant dose-dependent reduction in both melanoma and neuroblastoma colony formation only after D6 treatment. TUNEL assay, Annexin-V staining, caspases activation and PARP cleavage unveiled the ability of D6 to cause tumor cell death by triggering apoptosis, similarly to curcumin, but with a stronger and quicker extent. These apoptotic features appear to be associated with loss of mitochondrial membrane potential and cytochrome c release. In vivo anti-tumor activity of curcumin and D6 was surveyed using sub-cutaneous melanoma and orthotopic neuroblastoma xenograft models. D6 treated mice exhibited significantly reduced tumor growth compared to both control and curcumin treated ones (Melanoma: D6 vs control: P < 0.001 and D6 vs curcumin P < 0.01; Neuroblastoma: D6 vs both control and curcumin: P < 0.001)., Conclusions: Our data indicate D6 as a good candidate to develop new therapies against neural crest-derived tumors.

The HPLC enantiomeric separation of 29 racemic bridged polycyclic compounds was examined on commercially available Chiralcel OD-H and Chiralpak OT(+) columns. The separations were evaluated under normal-phase mode (hexane containing mobile phase) for Chiralcel OD-H and under normal-phase as well as under reversed-phase mode (pure MeOH, temperature 5 degrees C) for Chiralpak OT(+). Almost all compounds were resolved either on Chiralcel OD-H or on Chiralpak OT(+), in some cases on both. The use of trifluoroacetic acid (TFA), as modifier of the hexanic mobile phase, had a beneficial effect on the enantioseparation of some polar and acidic compounds on Chiralcel OD-H. The influence of small chemical structural modifications of the analytes on the enantioseparation behavior is discussed. A structure-retention relationship has been observed on both stationary phases. This chromatographic evaluation may provide some information about the chiral recognition mechanism: in the case of Chiralcel OD-H, hydrogen bonding, pi-pi and distereoselective repulsive are supposed to be the major analyte-CSP interactions. In the case of Chiralpak OT(+), a reversed-phase enantioseparation could take place through hydrophobic interactions between the aromatic moiety of the analytes and the chiral propeller structure of the CSP. The synthesis of some unknown racemic bromobenzobicyclo[2.2.1] analytes is also described.

The case is described of a Kikuchi-Fujimoto disease, in a 22-year-old female, onset of which was characterised by rapidly evolving lateral neck lymphadenopathy. Since clinico-radiological findings suggested a lymphoproliferative disease, it was mandatory, in order to establish the diagnosis and programme a suitable treatment protocol, to collect a lymph node biopsy specimen. The histological pattern was characteristic of Kikuchi-Fujimoto disease necrotizing lymphadenitis. Bearing in mind the difficulties encountered in the diagnosis of Kikuchi-Fujimoto disease, due not only to lack of a characteristic clinical pattern but also to the generic and aspecific findings emerging from radiological evaluation, the Authors stress the important role of histological examination in establishing the nature of the disease. In their opinion, onset of a rapidly evolving lateral neck lymphadenopathy, in a young patient, in the absence of well-defined disorders possibly responsible for the condition, and in order to establish a correct diagnostic approach, should induce the ENT specialist to take into consideration the possible presence of Kikuchi-Fujimoto disease, even if this is to be considered a rare finding.

The challenge to generate all-syn architecture has prompted the synthesis of syn cyclotrimers 2 from racemic bromotrimethylstannyl polycyclic alkenes 1. The syn-selective Cu I -catalyzed cyclotrimerization process is both regio- and chemoselective., (© 2001 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.)

In the lymphadenopathy occurring in the acquired immunodeficiency syndrome (AIDS) and the AIDS related complex (ARC), consistent histologic patterns have been described with some variants thereof, such as angioimmunoblastic lymphadenopathy-like or Castleman disease-like. In four such patients we have observed two other types of nodal lesions. Three patients had lymph node biopsies showing the characteristic histologic and immunophenotypic features of histiocytic necrotizing lymphadenitis (Kikuchi's disease). These were two males, 26 and 35-year old, with bilateral axillary and cervical lymphadenopathy, respectively, and one female, 29-years old with peripheral and abdominal lymphadenopathy. One patient had proteinaceous lymphadenopathy. This was a 26-year old man with disseminated lymphadenopathy and a small monoclonal IgG/k peak in the serum. Whether these two processes are direct effects of the HIV virus on the immune system or due to intercurrent etiologic factors, has to be determined. These observations, however, indicate that the range of nodal lesions (that the pathologist may encounter) in AIDS/ARC is wider than previously reported.

The clinical and pathological features of seven cases of lymphangioma-like Kaposi's sarcoma (KS) are reported. As with the other subtypes of KS, the lymphangioma-like variant occurs more often in men aged 59-80 years. Clinically, the lesion appears intermingled with the classical forms of KS, but a "bulla-like" appearance recognized in seven of 13 cases has been considered as a clinical hallmark of this variant. Although occasional cases have shown aggressive behavior, the most frequent clinical course is slowly progressive with localized or diffuse involvement of lower limbs. The histological pattern, characterized by permeation of dermal collagen by labyrinthine vascular channels lined by a flattened endothelium, must be differentiated from spindle cell hemangioendothelioma, low-grade angiosarcoma, targetoid hemosiderotic hemangioma, and benign lymphangioendothelioma.

A primary mesenchymal spindle cell tumor with amianthoid fibers was observed in an inguinal lymph node of a 70-year-old woman. With immunohistochemical stains the cells were positive for muscle actin and negative for desmin. Transmission electron microscopy (TEM) showed intracytoplasmic bundles of microfilaments with focal densities, profiles of rough endoplasmic reticulum, and basementlike material indicative of myofibroblastic and/or smooth-muscle cell differentiation. At scanning electron microscopy (SEM) the tumor was organized into slitlike spaces containing red blood cells. Amianthoid fibers showed a strong positivity for actin at their edge with a central negative core; by TEM they appeared to be formed of 200 nm thick crystallized collagen fibers surrounded by actin microfilaments arranged in a palisading fashion. The immunohistochemical and ultrastructural findings of the proliferating myoid cells suggest a possible derivation from smooth-muscle vascular cells. Collagen fiber aggregation and actin filament dismission might be secondary to anoxia due to vascular obliteration or disruption.