Xeroderma pigmentosum group F caused by a defect in a structure-specific DNA repair endonuclease

Rheumatoid arthritis (RA) is a chronic joint disease characterized by leukocyte invasion and synoviocyte activation followed by cartilage and bone destruction. Its etiology and pathogenesis are poorly understood. We describe a spontaneous mouse model of this syndrome, generated fortuitously by crossing a T cell receptor (TCR) transgenic line with the NOD strain. All offspring develop a joint disease highly reminiscent of RA in man. The trigger for the murine disorder is chance recognition of a NOD-derived major histocompatibility complex (MHC) class II molecule by the transgenic TCR; progression to arthritis involves CD4+ T, B, and probably myeloid cells. Thus, a joint-specific disease need not arise from response to a joint-specific antigen but can be precipitated by a breakdown in general mechanisms of self-tolerance resulting in systemic self-reactivity. We suggest that human RA develops by an analogous mechanism.     

Differential human multiple myeloma cell line responsiveness to interferon-alpha. Analysis of transcription factor activation and interleukin 6 receptor expression

Although IFN-alpha is commonly used as maintenance treatment for multiple myeloma patients, its effectiveness is varied. In this study, we have used a panel of IL-6 responsive myeloma cell lines that vary remarkably in responsiveness to IFN-alpha. Three cell lines were growth arrested by IFN-alpha; however, IFN-alpha significantly stimulated growth of the fourth cell line, KAS-6/1. Our studies have focused on elucidating the mechanism of differential IFN-alpha responsiveness. First, we have shown that IFN-alpha-stimulated growth of the KAS-6/1 cells did not result from induction of autocrine IL-6 expression. Second, analysis of Stats 1, 2, and 3 and IFN regulatory factor-1 (IRF-1) and IRF-2 activation failed to reveal differences between the IFN-alpha growth-arrested or growth-stimulated cells. Third, although IFN-alpha treatment of the IFN-alpha growth-inhibited cell lines reduced IL-6 receptor (IL-6R) expression, IFN-alpha also reduced KAS-6/1 IL-6R expression. Finally, although IFN-alpha treatment reduced IL-6R numbers on each cell line, analysis of Stat protein activation revealed that the receptors were still functional. We conclude that myeloma cell responsiveness to IFN-alpha is heterogeneous and that mechanisms of IFN-alpha-mediated growth inhibition other than IL-6R downregulation must exist in myeloma. Identification of these mechanisms may allow development of agents that are more universally effective than IFN-alpha.     

Distinction of CYP1A1 and CYP1A2 activity by selective inhibition using fluvoxamine and isosafrole

A one step competitive Enzyme-Linked Immunosorbent assay (ELISA) method was developed to detect mycobacterial antigen in cerebrospinal fluid (CSF) for the diagnosis of tuberculous meningitis and compared with a standard competitive ELISA method. Indigenously prepared soluble extract of Mycobacterium tuberculosis H37 Rv was used as antigen. The study was conducted using CSF of 230 clinically diagnosed cases of tuberculous meningit is and 208 control subjects. A cutoff value of 0.57 ng/ml by the one step ELISA and 0.5 ng/ml by the standard ELISA method were determined. The specificity of both methods were 100% and positivity was 68.26% and 70.43% respectively. A follow up study was conducted in 63 cases at various interval of time after starting anti-tubercular therapy i.e. at 3 weeks (63 cases), 6 weeks (27 cases) and > or = 4-12 months (13 cases). It was observed that antigen levels decreased gradually, but were much above the cutoff range. Indigenously prepared antigen was compared with antigen prepared in other laboratories and standard molecular weight markers using SDS PAGE (Sodium Do-decyl Sulphate Polycrylamide Gel Electrophoresis).     

Functional characteristics of ES cell-derived cardiac precursor cells identified by tissue-specific expression of the green fluorescent protein

In contrast to terminally differentiated cardiomyocytes, relatively little is known about the characteristics of mammalian cardiac cells before the initiation of spontaneous contractions (precursor cells). Functional studies on these cells have so far been impossible because murine embryos of the corresponding stage are very small, and cardiac precursor cells cannot be identified because of the lack of cross striation and spontaneous contractions. In the present study, we have used the murine embryonic stem (ES, D3 cell line) cell system for the in vitro differentiation of cardiomyocytes. To identify the cardiac precursor cells, we have generated stably transfected ES cells with a vector containing the gene of the green fluorescent protein (GFP) under control of the cardiac alpha-actin promoter. First, fluorescent areas in ES cell-derived cell aggregates (embryoid bodies [EBs]) were detected 2 d before the initiation of contractions. Since Ca2+ homeostasis plays a key role in cardiac function, we investigated how Ca2+ channels and Ca2+ release sites were built up in these GFP-labeled cardiac precursor cells and early stage cardiomyocytes. Patch clamp and Ca2+ imaging experiments proved the functional expression of the L-type Ca2+ current (ICa) starting from day 7 of EB development. On day 7, using 10 mM Ca2+ as charge carrier, ICa was expressed at very low densities 4 pA/pF. The biophysical and pharmacological properties of ICa proved similar to terminally differentiated cardiomyocytes. In cardiac precursor cells, ICa was found to be already under control of cAMP-dependent phosphorylation since intracellular infusion of the catalytic subunit of protein kinase A resulted in a 1.7-fold stimulation. The adenylyl cyclase activator forskolin was without effect. IP3-sensitive intracellular Ca2+ stores and Ca2+-ATPases are present during all stages of differentiation in both GFP-positive and GFP-negative cells. Functional ryanodine-sensitive Ca2+ stores, detected by caffeine-induced Ca2+ release, appeared in most GFP-positive cells 1-2 d after ICa. Coexpression of both ICa and ryanodine-sensitive Ca2+ stores at day 10 of development coincided with the beginning of spontaneous contractions in most EBs. Thus, the functional expression of voltage-dependent L-type Ca2+ channel (VDCC) is a hallmark of early cardiomyogenesis, whereas IP3 receptors and sarcoplasmic Ca2+-ATPases are expressed before the initiation of cardiomyogenesis. Interestingly, the functional expression of ryanodine receptors/sensitive stores is delayed as compared with VDCC.     

An adaptive control algorithm for optimization of intensity modulated radiotherapy considering uncertainties in beam profiles, patient set-up and internal organ motion

A new general beam optimization algorithm for inverse treatment planning is presented. It utilizes a new formulation of the probability to achieve complication-free tumour control. The new formulation explicitly describes the dependence of the treatment outcome on the incident fluence distribution, the patient geometry, the radiobiological properties of the patient and the fractionation schedule. In order to account for both measured and non-measured positioning uncertainties, the algorithm is based on a combination of dynamic and stochastic optimization techniques. Because of the difficulty in measuring all aspects of the intra- and interfractional variations in the patient geometry, such as internal organ displacements and deformations, these uncertainties are primarily accounted for in the treatment planning process by intensity modulation using stochastic optimization. The information about the deviations from the nominal fluence profiles and the nominal position of the patient relative to the beam that is obtained by portal imaging during treatment delivery, is used in a feedback loop to automatically adjust the profiles and the location of the patient for all subsequent treatments. Based on the treatment delivered in previous fractions, the algorithm furnishes optimal corrections for the remaining dose delivery both with regard to the fluence profile and its position relative to the patient. By dynamically refining the beam configuration from fraction to fraction, the algorithm generates an optimal sequence of treatments that very effectively reduces the influence of systematic and random set-up uncertainties to minimize and almost eliminate their overall effect on the treatment. Computer simulations have shown that the present algorithm leads to a significant increase in the probability of uncomplicated tumour control compared with the simple classical approach of adding fixed set-up margins to the internal target volume.     

Increase in plasma leptin and Lep mRNA concentrations by food intake is dependent on insulin

The difference in pregnancy rates following intrauterine insemination (IUI) for 1 vs. 2 days in the periovulatory period has been reported as either inconsequential or favoring the use of two consecutive inseminations, 24 hours apart. Our study compared the monthly fecundity and cumulative probability of pregnancy in a large group of women (n = 123) undergoing controlled ovarian hyperstimulation and 1- or 2-day inseminations with donor sperm prepared from frozen-thawed samples. All patients underwent controlled ovarian hyperstimulation employing either clomiphene citrate in 217 cycles or human menopausal gonadotropin in 185 cycles. The choice of single or double insemination was decided by the day of the week each patient received human chorionic gonadotropin for ovulation induction. Approximately 80% of all the patients underwent both single and double insemination treatments during the 2.5-year study period. Ninety-three patients received single inseminations in 180 cycles, whereas 103 patients received double inseminations in 222 cycles. Nine clinical pregnancies were achieved in the 1-day group (5% per cycle, 9.7% per patient), while 39 pregnancies occurred in the 2-day group (17.9% per cycle, 37.9% per patient). Two and five spontaneous abortions occurred in the 1- and 2-day groups, yielding take-home baby rates of 3.9% per cycle (7.5% per patient) and 15.3% per cycle (33.0% per patient), respectively. The cumulative probability of conception over 15 cycles of treatment was consistently twice as high or higher for the 2-day group. The results of this study support the use of 2-day IUI treatment cycles when using frozen-thawed donor sperm.