Beta2-adrenergic receptor gene polymorphisms and pregnancy outcome

AIMS: The association between alleles at two loci of the polymorphic beta2-adrenergic receptor (beta2AR) gene and pregnancy outcome was determined. METHODS: In a case-control study, buccal swabs obtained from 159 mother-infant pairs after a preterm or term birth were analyzed by gene amplification and endonuclease digestion for polymorphisms at codons 16 and 27 of the beta2AR gene. RESULTS: Homozygosity for allele A at codon 16 (Arg-16) occurred in 26 (20.5%) of 127 mothers with a term birth and in none of the mothers who had a spontaneous preterm birth (p=0.002). Conversely, 24 of 32 (75.0%) mothers with a spontaneous preterm birth, as compared to 58 of 127 (45.7%) mothers with term births, were Arg-16/ allele G (Gly-16) heterozygotes (p=0.003). There was no relation between pregnancy outcome and infant genotype at codon 16 or maternal or infant genotypes at codon 27. The alleles at codon 16 and 27 were in linkage disequilibrium and the combinations of Arg-16-Gln-27 homozygosity (p=0.04) and Arg-16/Gly-16-Gln homozygous (p=0.01) were associated with a decreased and increased rate of spontaneous preterm birth, respectively. CONCLUSION: At codon 16 of the beta2-AR gene, maternal Arg-16 homozygosity protects against, and Gly-16 predisposes to spontaneous preterm birth.     

Steroid cell tumour not otherwise specified during pregnancy: a case report and diagnostic work-up for virilisation in a pregnant patient

Steroid cell tumours not otherwise specified are rare ovarian tumours, which can cause foetal and maternal virilisation. This is the first case report that describes a steroid cell tumour not otherwise specified during pregnancy. Differential diagnosis, a diagnostic work-up and treatment are discussed.     

Micellar aggregation and membrane partitioning of bile salts, fatty acids, sodium dodecyl sulfate, and sugar-conjugated fatty acids: correlation with hemolytic potency and implications for drug delivery

The co-administration of a drug with a penetration enhancer (PE) is one method by which the membrane permeability of a drug can be improved. To facilitate PE design, it is important that the molecular basis of PE toxicity and efficacy be examined, so we investigated the membrane affinity and micellar aggregation of a series of synthetic liposaccharide PEs and correlated these properties with hemolytic potency. The influence of liposaccharide alkyl chain length (nc) on the system was studied, and comparisons were made with conventional PEs such as bile salts, fatty acids, and surfactants. The liposaccharides were each synthesized in eight steps in good overall yield. Their critical micelle concentrations (CMCs) in phosphate-buffered saline ranged from 0.207 to 20.2 mM, and it was found that increasing nc by 2 afforded a 1 order of magnitude decrease in the CMC. Immobilized artificial membrane (IAM) chromatography was used to determine each PE's affinity for biological membranes, and an increase in nc caused a significant increase in the extent of membrane binding. A study of hemolytic activity revealed that liposaccharides with an nc of < or = 12 are the most likely to be biocompatible. The CMC values for all PEs showed a negative correlation with hemolytic potency; however, it was PE monomers, not micelles, that were responsible for the onset of hemolysis. The affinity of all enhancers for the IAM displayed a positive correlation with hemolytic potency, and therefore, IAM chromatography can be used to predict PE hemolytic activity. It was concluded that the biocompatibility of liposaccharides can be modulated by minor alterations in nc.     

The utility of p16INK4a and Ki-67 staining on cell blocks prepared from residual thin-layer cervicovaginal material

BACKGROUND: Cell blocks can be prepared from residual thin-layer cervicovaginal (ThinPrep) material and can be used in immunohistochemical staining assays for p16INK4a and Ki-67, which are surrogate markers related to human papillomavirus infection and cell proliferation, respectively. The objectives of the current study were 1) to investigate the feasibility and the role of cell block preparations in identifying significant neoplastic and preneoplastic lesions of the uterine cervix and 2) to assess the feasibility of using p16INK4a and Ki-67 immunohistochemical staining patterns on cell blocks to identify significant preneoplastic cervical lesions. METHODS: Cervicovaginal cytology specimens from 85 patients were analyzed. Cytologic diagnoses based on ThinPrep Papanicolaou test results were as follows: squamous cell carcinoma was diagnosed in 3 specimens, high-grade squamous intraepithelial lesions (HSIL) were diagnosed in 27 specimens, low-grade squamous intraepithelial lesions (LSIL) were diagnosed in 20 specimens, and atypical squamous cells of uncertain significance (ASCUS) were diagnosed in 11 specimens. Diagnoses of negativity for intraepithelial lesions or malignancy (NILM) were made in 24 specimens. Cell block sections were stained with hematoxylin and eosin and were immunostained with antibodies against p16INK4a protein and Ki-67 antigen. RESULTS: The cytomorphologic diagnoses made using cell block preparations were as follows: SCC in 2 specimens, HSIL in 20 specimens, LSIL in 30 specimens, NILM in 32 specimens, and no diagnosis in 1 specimen. In 62 cases (73%), the diagnoses made using cell block preparations were in agreement with the ThinPrep diagnoses. Immunostaining of cell blocks for p16INK4a and Ki-67 exhibited a statistically significant association (P < 0.05) with the presence of significant lesions on either cell block or ThinPrep analysis. CONCLUSIONS: To the authors' knowledge, p16INK4a has not been analyzed previously in ThinPrep cell blocks, and the correlation between Ki-67 expression and cell block diagnoses also has not been reported previously. The current results indicate that cell blocks prepared from residual ThinPrep material represent an additional reliable diagnostic tool in the evaluation of cervical samples. Furthermore, immunohistochemical studies may be helpful in differentiating significant preneoplastic changes from other cervical lesions, such as atrophy.     

Interferon-gamma pharmacokinetics and pharmacodynamics in patients with colorectal cancer

Purpose The study objectives were to define subcutaneous (s.c.) interferon gamma (IFN-) disposition in patients with gastrointestinal malignancies receiving 5-fluorouracil (5-FU) and leucovorin (LV) and to examine the relationship between IFN- exposures and Fas upregulation in vivo and in vitro.Methods Patients received IFN- (10, 25, 50, 75, and 100 g/m²) with LV and 5-FU, and serial samples were collected after the first dose. IFN- concentrations were measured by ELISA. A linear one-compartment model with a lag was fitted to the IFN- plasma concentration-time data. To examine the relationship between IFN- systemic exposure and biological activity in vivo, cell surface Fas upregulation was assessed in peripheral blood mononuclear cell (PBMC) subcompartments.Results The median (range) apparent IFN- clearance was 46 l/m² per hour (2.6–92 l/m² per hour). With increasing IFN- dosages, the area under the concentration-time curve (AUC₀) and C_max increased; however, significant interpatient variability was observed. IFN- AUC₀ and time above 33.3 pg/ml significantly correlated with Fas upregulation in several PBMC compartments, but dosage was significantly correlated with this pharmacodynamic marker only in CD4⁺ and CD56⁺ cells. In vitro studies in HT29 cells demonstrated that clinically relevant IFN- concentrations (1 to 10 U/ml for 6.5 h) with 5-FU/LV upregulated Fas expression 3.5-fold, similar to that in PBMC in vivo.Conclusions We characterized IFN- disposition and developed a limited sampling model for use in future pharmacokinetic studies. Our results showed that IFN- upregulates Fas in PBMC in vivo and in HT29 cells in vitro at tolerable, clinically relevant exposures and that monitoring IFN- pharmacokinetics/pharmacodynamics may be warranted in IFN- clinical use.This work was supported in part by US Public Health Service awards CA23099, CA32613 and CA23944, the Wings Cancer Foundation, and American Lebanese Syrian Associated Charities (ALSAC).     

Olanzapine versus clozapine in treatment-resistant or treatment-intolerant schizophrenia

Clozapine has been the gold standard for treatment of patients with refractory schizophrenia but is associated with serious safety liabilities. This has prompted the search for therapeutic alternatives for treatment-resistant schizophrenia. The objective of this study was to compare the efficacy and safety of olanzapine versus clozapine in schizophrenic patients who failed to respond adequately to antipsychotic medication or who experienced intolerable adverse effects associated with the medication. This 18-week, randomized, double-blind, parallel study compared treatment with either olanzapine (5-25 mg/day, n=75) or clozapine (100-500 mg/day, n=72) in patients with schizophrenia who were nonresponsive to, or intolerant of, standard acceptable antipsychotic therapy. At the 18-week endpoint, no statistically significant differences were found between olanzapine and clozapine in any efficacy measure used: Positive and Negative Syndrome Scale (PANSS) total, positive, negative, or general psychopathology or Clinical Global Impression severity (CGI-S). Response rates based on the criteria of Kane et al. [Arch. Gen. Psychiatry 45 (1988) 789] were also not significantly different between olanzapine-treated (57.9%) and clozapine-treated patients (60.8%). There were no significant differences in measurements of extrapyramidal symptoms or electrocardiography, and no clinically and statistically significant changes were seen in vital signs or laboratory measures in either group. Both treatments were well tolerated. Olanzapine demonstrated similar efficacy to clozapine in patients who had failed previous treatment because of lack of efficacy (treatment resistance) or intolerable side effects (treatment intolerance). Olanzapine therefore presents a safe alternative in the treatment of refractory schizophrenia.     

The cytotoxicity of iodinated radiocontrast agents on renal cells in vitro

A deterioration of renal function is one preoccupying complication of iodinated radiocontrast agents in clinical practice. These compounds have direct toxic effects on renal cells, which are only in part related to their physicochemical properties. The hyperosmolal monomeric ionic radiocontrast agents, like diatrizoate, have the highest toxicity, whereas renal cells are less affected by (nonionic) compounds with reduced osmolality. The toxic effects include cellular energy failure, a disruption of calcium homeostasis, a disturbance of tubular cell polarity and programmed cell death (apoptosis). The molecular mechanisms of the direct cytotoxicity are still unclear, although oxidative stress has been implicated. Radiocontrast cytotoxicity has been demonstrated in glomerular mesangial cells and in renal epithelial cells in vitro. In vivo, the direct cellular toxicity of radiocontrast agents is compounded with alterations in blood flow and/or viscosity, ultimately resulting in renal medullary hypoxia, which is a hallmark feature of the complex clinical syndrome of radiocontrast nephropathy.     

The relationship of von Willebrand factor binding to activated platelets from healthy neonates and adults

von Willebrand Factor (VWF) is important in platelet adhesion and shear-dependent platelet activation. We performed flow cytometric analyses of VWF binding to and activation of platelets from healthy neonates, children, and adults. Platelets from cord blood (n = 38; gestational age: 36-42 wk; birth weight: 2.4-5.1 kg), neonatal venous blood (n = 19; d 2-3 of life), children (n = 15; age: 1.5-16.3 y), and adults (n = 22; age: 18-55 y) were studied. Binding of VWF was assessed using an antihuman VWF polyclonal antibody and a FITC-conjugated secondary antibody. Platelet activation was determined by the expression of CD62P, CD63, CD41, CD42b, activated GPIIb/IIIa (PAC-1), procoagulant surface (as reflected by annexin V binding), and microparticle formation. Although the mean percentage of VWF-positive platelets was not significantly higher in unstimulated platelets from 2- to 3-d-old neonates, their platelets were more activated than those from adults, and there was a positive correlation of VWF binding with platelet activation (CD62P: r = 0.74, p < 0.001; annexin V: r = 0.46, p < 0.05). In adults, after in vitro activation of platelets with thrombin and ADP, VWF binding to platelets increased and correlated significantly with CD62P expression (r = 0.71, p < 0.001). VWF binding to unstimulated neonatal platelets was, however, higher than that to in vitro-stimulated platelets from adults at the same level of expression of platelet activation markers. Further studies are required to assess the mechanism and significance of VWF binding to activated platelets in the neonatal period.