Measurement of the

The cross section of the ^{13}C(α,n)^{16}O reaction is needed for nuclear astrophysics and applications to a precision of 10% or better, yet inconsistencies among 50 years of experimental studies currently lead to an uncertainty of ≈15%. Using a state-of-the-art neutron detection array, we have performed a high resolution differential cross section study covering a broad energy range. These measurements result in a dramatic improvement in the extrapolation of the cross section to stellar energies potentially reducing the uncertainty to ≈5% and resolving long standing discrepancies in higher energy data.

Circulating macrophages as the mechanistic link between mosaic loss of Y-chromosome and cardiac disease.

BACKGROUND: Genetics evidences have long linked mosaic loss of Y-chromosome (mLOY) in peripheral leukocytes with a wide range of male age-associated diseases. However, a lack of cellular and molecular mechanistic explanations for this link has limited further investigation into the relationship between mLOY and male age-related disease. Excitingly, Sano et al. have provided the first piece of evidence directly linking mLOY to cardiac fibrosis through mLOY enriched profibrotic transforming growth factor ß1 (TGF-ß1) regulons in hematopoietic macrophages along with suppressed interleukin-1ß (IL-1ß) proinflammatory regulons. The results of this novel finding can be extrapolated to other disease related to mLOY, such as cancer, cardiac disease, and age-related macular degeneration. RESULTS: Sano et al. used a CRISPR-Cas9 gRNAs gene editing induced Y-chromosome ablation mouse model to assess results of a UK biobank prospective analysis implicating the Y-chromosome in male age-related disease. Using this in vivo model, Sano et al. showed that hematopoietic mLOY accelerated cardiac fibrosis and heart failure in male mice through profibrotic pathways. This process was linked to monocyte-macrophage differentiation during hematopoietic development. Mice confirmed to have mLOY in leukocytes, by loss of Y-chromosome genes Kdm5d, Uty, Eif2s3y, and Ddx3y, at similar percentages to the human population were shown to have accelerated rates of interstitial and perivascular fibrosis and abnormal echocardiograms. These mice also recovered poorly from the transverse aortic constriction (TAC) model of heart failure and developed left ventricular dysfunction at higher rates. This was attributed to aberrant proliferation of cardiac MEF-SK4 + fibroblasts promoted by mLOY macrophages enriched in profibrotic regulons and lacking in proinflammatory regulons. These pro-fibrotic macrophages localized to heart and eventually resulted in cardiac fibrosis via enhanced TGF-ß1 and suppressed IL-1ß signaling. Furthermore, treatment of mLOY mice with TGFß1 neutralizing antibody was able to improve their cardiac function. This study by Sano et al. was able to provide a causative link between the known association between mLOY and male cardiac disease morbidity and mortality for the first time, and thereby provide a new target for improving human health. CONCLUSIONS: Using a CRISPR-Cas9 induced Y-chromosome ablation mouse model, Sano et al. has proven mosaic loss of Y-chromosome in peripheral myeloid cells to have a causative effect on male mobility and mortality due to male age-related cardiac disease. They traced the mechanism of this effect to hyper-expression of the profibrotic TGF-ß1 and reduced pro-inflammatory IL-1ß signaling, attenuation of which could provide another potential strategy in improving outcomes against age-related diseases in men.

Clinical validation of an adapted Eleveld Model for high-dose propofol treatments for depression.

Repeated administration of high doses of propofol to patients with treatment-resistant depression (TRD) has been shown to produce antidepressant effects in small clinical trials. These effects can be elicited when the patient's EEG burst-suppression ratio (BSR) is maintained at 70-90% for 15 min in repeated treatments. This deep anesthesia domain lies beyond the range of current propofol pharmacokinetic/pharmacodynamic (PK/PD) models. In this study, we adapt the Eleveld model for use at deep anesthesia levels with a BSR endpoint, with the goal of aiding the estimation of the dosage of propofol needed to achieve 70-90% BSR for 15 min. We test the ability of the adapted model to predict BSR for these treatments. Twenty participants underwent 6-9 treatments of high doses of propofol (5-9 of which were included in this analysis) for a total of 115 treatments. To adapt the Eleveld model for this endpoint, we optimized the model parameters Ke0, γ and Ce50. These parameters were then used in the adapted model to estimate second-by-second BSR for each treatment. Estimated BSR was compared with observed BSR for each treatment of each participant. Median absolute performance error (MdAPE) between the estimated and observed BSR (25th-75th percentile) was 6.63 (3.79-12.96) % points and 8.51 (4.32-16.74) % between the estimated and observed treatment duration. This predictive performance is statistically significantly better at predicting BSR compared with the standard Eleveld model at deep anesthesia levels. Our adapted Eleveld model provides a useful tool to aid dosing propofol for high-dose anesthetic treatments for depression.

Cardiac-Specific Expression of Cre Recombinase Leads to Age-Related Cardiac Dysfunction Associated with Tumor-like Growth of Atrial Cardiomyocyte and Ventricular Fibrosis and Ferroptosis.

Transgenic expression of Cre recombinase driven by a specific promoter is normally used to conditionally knockout a gene in a tissue- or cell-type-specific manner. In αMHC-Cre transgenic mouse model, expression of Cre recombinase is controlled by the myocardial-specific α-myosin heavy chain (αMHC) promoter, which is commonly used to edit myocardial-specific genes. Toxic effects of Cre expression have been reported, including intro-chromosome rearrangements, micronuclei formation and other forms of DNA damage, and cardiomyopathy was observed in cardiac-specific Cre transgenic mice. However, mechanisms associated with Cardiotoxicity of Cre remain poorly understood. In our study, our data unveiled that αMHC-Cre mice developed arrhythmias and died after six months progressively, and none of them survived more than one year. Histopathological examination showed that αMHC-Cre mice had aberrant proliferation of tumor-like tissue in the atrial chamber extended from and vacuolation of ventricular myocytes. Furthermore, the αMHC-Cre mice developed severe cardiac interstitial and perivascular fibrosis, accompanied by significant increase of expression levels of MMP-2 and MMP-9 in the cardiac atrium and ventricular. Moreover, cardiac-specific expression of Cre led to disintegration of the intercalated disc, along with altered proteins expression of the disc and calcium-handling abnormality. Comprehensively, we identified that the ferroptosis signaling pathway is involved in heart failure caused by cardiac-specific expression of Cre, on which oxidative stress results in cytoplasmic vacuole accumulation of lipid peroxidation on the myocardial cell membrane. Taken together, these results revealed that cardiac-specific expression of Cre recombinase can lead to atrial mesenchymal tumor-like growth in the mice, which causes cardiac dysfunction, including cardiac fibrosis, reduction of the intercalated disc and cardiomyocytes ferroptosis at the age older than six months in mice. Our study suggests that αMHC-Cre mouse models are effective in young mice, but not in old mice. Researchers need to be particularly careful when using αMHC-Cre mouse model to interpret those phenotypic impacts of gene responses. As the Cre-associated cardiac pathology matched mostly to that of the patients, the model could also be employed for investigating age-related cardiac dysfunction.

The Prognostic Significance of FKBP1A and Its Related Immune Infiltration in Liver Hepatocellular Carcinoma.

Liver hepatocellular carcinoma (LIHC) remains a global health challenge with poor prognosis and high mortality. FKBP1A was first discovered as a receptor for the immunosuppressant drug FK506 in immune cells and is critical for various tumors and cancers. However, the relationships between FKBP1A expression, cellular distribution, tumor immunity, and prognosis in LIHC remain unclear. Here, we investigated the expression level of FKBP1A and its prognostic value in LIHC via multiple datasets including ONCOMINE, TIMER, GEPIA, UALCAN, HCCDB, Kaplan-Meier plotter, LinkedOmics, and STRING. Human liver tissue microarray was employed to analyze the characteristics of FKBP1A protein including the expression level and pathological alteration in cellular distribution. FKBP1A expression was significantly higher in LIHC and correlated with tumor stage, grade and metastasis. The expression level of the FKBP1A protein was also increased in LIHC patients along with its accumulation in endoplasmic reticulum (ER). High FKBP1A expression was correlated with a poor survival rate in LIHC patients. The analysis of gene co-expression and the regulatory pathway network suggested that FKBP1A is mainly involved in protein synthesis, metabolism and the immune-related pathway. FKBP1A expression had a significantly positive association with the infiltration of hematopoietic immune cells including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells. Moreover, M2 macrophage infiltration was especially associated with a poor survival prognosis in LIHC. Furthermore, FKBP1A expression was significantly positively correlated with the expression of markers of M2 macrophages and immune checkpoint proteins such as PD-L1, CTLA-4, LAG3 and HAVCR2. Our study demonstrated that FKBP1A could be a potential prognostic target involved in tumor immune cell infiltration in LIHC.

Mosaic loss of chromosome Y in peripheral blood cells is associated with age-related macular degeneration in men.

BACKGROUND: Age-related macular degeneration (AMD) is the leading cause of severe vision loss in patients over 55 years old in the industrialized world. In the past 20 years, approximately 288 million patents have been affected by this disease. Despite this high prevalence, the molecular mechanism for AMD remains unclear, and there remains no effective treatment for this disease. The mosaic loss of Y chromosome (mLOY) has been identified as a common phenomenon in multiple age-related disease (i.e., oncogenesis and cardiovascular disease) has recently been identified by genome-wide analysis to be linked to AMD as well. As the Y chromosome mainly possesses three genomic functions, sister chromatin cohesion, cell cycle mitosis, and apoptotic signaling, here we characterize the Y chromosome euchromatic genes and non-chromosome AMD genes in relevance to cellular proliferation and apoptotic signaling of leukocytes. RESULTS: Using STRING, a publically available database of all protein-protein interaction, Grassmann et al. found the genes on the Y chromosome is mainly believed to take part in three major cellular genomic functions- sister chromatin cohesion, cell cycle mitosis, and apoptotic signaling. Based on data from the Ensembl Genome database, we focus on our discussion on coding genes found in the euchromatins but not the PAR1 and PAR2 regions of the Y chromosomes. All 14 known euchromatic genes on the Y chromosome short arm and all 31 known euchromatic genes on the Y chromosome long arm (Yq) are directly or indirectly involved in the cell cycle (meiosis and mitosis) and proliferation. We sorted non-Y chromosome AMD associated genes into these three categories to identify signaling pathways that may compound with cellular dysregulation due to mLOY. Of the genes associated with AMD, complement pathway genes such as C2, C9 and CFH/ARMD4 are associated with proliferation, receptor-mediated endocytosis genes such as APOE, DAB2 and others associated with apoptotic signaling. Because nucleated cells found in peripheral circulation are mainly composed of leukocytes with reduced expression of CD99, a protein essential for leukocytes adhesion, translocation, and function, mLOY in these cells likely affect retinal degeneration through altered immunological surveillance. In fact, there is precedence that circulating macrophage can stabilize and modify the cardiac rhythm and contractility post ischemic damage. Therefore, the most likely mechanism through which peripheral mLOY affects AMD development in men is through the role affected leukocytes play in retinal proliferation and apoptosis. CONCLUSIONS: mLOY in peripheral blood is newly discovered in AMD by Grassmann et al. as it is a common phenomenon in oncogenesis and cardiac dysfunction. Here the recent data conclude the possible mechanism for the newly identified link between mLOY and AMD, and provide support that mLOY in circulating macrophage-monocyte of affected male patients promotes AMD by targeting the retina and causing macular degeneration.

A Protocol for Immunohistochemistry and RNA In-situ Distribution within Early Drosophila Embryo.

Calcium induced calcium release signaling (CICR) plays a critical role in many biological processes. Every cellular activity from cell proliferation and apoptosis, development and ageing, to neuronal synaptic plasticity and regeneration have been associated with Ryanodine receptors (RyRs). Despite the importance of calcium signaling, the exact mechanism of its function in early development is unclear. As an organism with a short gestational period, the embryos of Drosophila melanogaster are prime study subjects for investigating the distribution and localization of CICR associated proteins and their regulators during development. However, because of their lipid-rich embryos and chitin-rich chorion, their utility is limited by the difficulty of mounting embryos on glass surfaces. In this work, we introduce a practical protocol that significantly enhances the attachment of Drosophila embryo onto slides and detail methods for successful histochemistry, immunohistochemistry, and in-situ hybridization. The chrome alum gelatin slide-coating method and embryo pre-embedding method dramatically increases the yield in studying Drosophila embryo protein and RNA expression. To demonstrate this approach, we studied DmFKBP12/Calstabin, a well-known regulator of RyR during early embryonic development of Drosophila melanogaster. We identified DmFKBP12 in as early as the syncytial blastoderm stage and report the dynamic expression pattern of DmFKBP12 during development: initially as an evenly distributed protein in the syncytial blastoderm, then preliminarily localizing to the basement layer of the cortex during cellular blastoderm, before distributing in the primitive neuronal and digestion architecture during the three-gem layer phase in early gastrulation. This distribution may explain the critical role RyR plays in the vital organ systems that originate in from these layers: the suboesophageal and supraesophageal ganglion, ventral nervous system, and musculoskeletal system.

Nonalcoholic fatty liver disease experiences accumulation of hepatic liquid crystal associated with increasing lipophagy.

BACKGROUND: In the past 30 years, incidences of non-alcoholic fatty liver disease (NAFLD) has risen by 30%. However, there is still no clear mechanism or accurate method of anticipating liver failure. Here we reveal the phase transitions of liquid crystalline qualities in hepatic lipid droplets (HLDs) as a novel method of anticipating prognosis. METHODS: NAFLD was induced by feeding C57BL/6J mice on a high-fat (HiF) diet. These NAFLD livers were then evaluated under polarized microscopy, X-ray diffraction and small-angle scattering, lipid component chromatography analysis and protein expression analysis. Optically active HLDs from mouse model and patient samples were both then confirmed to have liquid crystal characteristics. Liver MAP1LC3A expression was then evaluated to determine the role of autophagy in liquid crystal HLD (LC-HLD) formation. RESULTS: Unlike the normal diet cohort, HiF diet mice developed NAFLD livers containing HLDs exhibiting Maltese cross birefringence, phase transition, and fluidity signature to liquid crystals. These LC-HLDs transitioned to anisotropic crystal at 0 °C and remain crystalline. Temperature increase to 42 °C causes both liquid crystal and crystal HLDs to convert to isotropic droplet form. These isotropic HLDs successfully transition to anisotropic LC with fast temperature decrease and anisotropic crystal with slow temperature decrease. These findings were duplicated in patient liver. Patient LC-HLDs with no inner optical activity were discovered, hinting at lipid saturation as the mechanism through which HLD acquire LC characteristics. Downregulation of MAP1LC3A in conjunction with increased LC-HLD also implicated autophagy in NAFLD LC-HLD formation. CONCLUSIONS: Increasing concentrations of amphiphilic lipids in HLDs favors organization into alternating hydrophilic and hydrophobic layers, which present as LC-HLDs. Thus, evaluating the extent of liquid crystallization with phase transition in HLDs of NAFLD patients may reveal disease severity and predict impending liver damage.

Physical exercise: bulking up neurogenesis in human adults.

Whether neurogenesis occurs in the adult human brain has been a long-debated topic fueled by conflicting data both for and against neurogenesis in the mature brain. Recent reports from two independent teams may have indubitably proven that adult, hippocampal neurogenesis persists throughout the human lifespan. Llorens-Martín et al. found that thousands of immature, neurogenesis related, doublecortin-positive (DCX+) labelled neurons can be detected in the human dentate gyrus (DG) up to the eighth decade of life. While the presence of these DCX+ neurons decrease with age, they are significantly decrease in patient with Alzheimer's disease. Another group have also found mammalian embryonic Hopx+ precursors to persist beyond the early development stage as quiescent Hopx+ radial glial-like neural progenitors during early postnatal period, then as Hopx+ adult dentate neural progenitors. Together, the findings from these two groups suggest that unlike the previously thought, neurogenesis and neuroplasticity can occur well into adulthood in some capacity, at least in the hippocampus. These recent findings that neurogenesis can occur beyond development have brought into questions whether physical exercise can be shown to promote neurogenesis and brain health, as it has been shown to promote the function of other organ systems. Some data has already shown physical exercise to induce adult hippocampal neurogenesis (AHN) as demonstrated by restoration of cognitive functions, improvement of synaptic plasticity, and enhancement of angiogenesis. A large-scale meta-analysis has also demonstrated that 45-60 min of moderate-intensity physical exercise to dramatically improve cognitive functions in human subjects over the age of 50. Given these convergent developments in our understanding of neurogenesis and exercise induced improvement in cognitive function, we speculate that hippocampal neurogenesis can be promoted by physical exercise and discuss the current molecular evidence supporting the likely molecular pathways involved.

Characterization of tubular liquid crystal structure in embryonic stem cell derived embryoid bodies.

BACKGROUND: Massive liquid crystal droplets have been found during embryonic development in more than twenty different tissues and organs, including the liver, brain and kidney. Liquid crystal deposits have also been identified in multiple human pathologies, including vascular disease, liver dysfunction, age-related macular degeneration, and other chronic illnesses. Despite the involvement of liquid crystals in such a large number of human processes, this phenomenon is poorly understood and there are no in vitro systems to further examine the function of liquid crystals in biology. RESULTS: We report the presence of tubular birefringent structures in embryoid bodies (EBs) differentiated in culture. These birefringent tubular structures initiate at the EB surface and penetrated the cortex at a variety of depths. Under crossed polarized light, these tubules are seen as a collection of birefringent Maltese crosses and tubules with birefringent walls and a non-birefringent lumen. The fluidity of these birefringent structures under pressure application led to elongation and widening, which was partially recoverable with pressure release. These birefringent structures also displayed heat triggered phase transition from liquid crystal to isotropic status that is partially recoverable with return to ambient temperature. These pressure and temperature triggered changes confirm the birefringent structures as liquid crystals. The first report of liquid crystal so early in development. CONCLUSION: The structure of the liquid crystal tubule network we observed distributed throughout the differentiated embryoid bodies may function as a transportation network for nutrients and metabolic waste during EB growth, and act as a precursor to the vascular system. This observation not only reveals the involvement of liquid crystals earlier than previously known, but also provides a method for studying liquid crystals in vitro.

Inflammatory papillomatous hyperplasia and epidermal necrosis in a transgenic rat for HIV-1.

BACKGROUND: Skin lesions commonly affect AIDS patients. The pathogenesis of certain dermatologic disorders primarily associated to HIV-1 is unclear, and better forms of therapy for these conditions need to be discovered. Transgenic animal models represent a novel approach for the study of these disorders and for the quest of more effective forms of treatment. OBJECTIVE: Characterize this HIV-1 transgenic rat as a model to study skin diseases related to HIV/AIDS. METHODS: A transgenic rat was developed, using an HIV-1 construct with deleted gag and pol genes. Morphological and genotypical evaluations were followed by cytokine profile characterization of the lesions. RESULTS: We report the characterization of a colony of HIV-1 transgenic rats that developed skin lesions in a frequency of 22.5%. Cutaneous expression of functional HIV-1 transgenes correlated precisely with the severity of the phenotype. In early stages, rats manifested localized areas of xerosis and dispersed papulosquamous lesions. These hyperplastic manifestations were observed in conjunction with an increased epidermal expression of tat protein and a Th1/Th2 profile of cytokines. As the lesions progressed, they formed inflammatory plaques that subsequently ulcerated. Histologically, these lesions displayed a profound lymphocytic infiltrate, epidermal necrosis, and a marked increase of both Th1 and Th2 derived cytokines. Moreover, the presence of circulating IgG antibodies against HIV-1 gp120 was detected. CONCLUSION: This animal model as other HIV-1 transgenic mice described in the past, is not able to fully explain the myriad of skin findings that can occur in HIV-infected humans; however, it represents a potential animal model system for the study of immune-mediated inflammatory skin diseases.

Characterization of an anti-lymphocyte function-associated antigen-1 antibody in a simian immunodeficiency virus-pig-tailed macaque (Macaca nemestrina) model.

The simian immunodeficiency virus (SIV)/pig-tailed macaque (Macaca nemestrina) model of acquired immune deficiency syndrome (AIDS) is a powerful system in which to study cell adhesion molecules and retroviral pathogenesis in vivo. Preliminary experiments were conducted to examine the role of lymphocyte function-associated antigen 1 (LFA-1) in early SIV infection in vivo by using an LFA-1 monoclonal antibody (MHM.23) specific to human LFA-1. In vitro studies revealed that at concentrations of > or = 20 microg/ml, MHM.23 blocked LFA-1-mediated adhesion and T-cell activation (>90%) of pig-tailed macaque peripheral blood mononuclear cells (PBMCs). In addition, SIVmac239 infection of macaque cells was inhibited in a dose-dependant manner by MHM.23. Administration of MHM.23 to pig-tailed macaques inhibited LFA-1-ICAM-1-mediated activity in vivo and maintained binding on macaque cells for < or = 4 d. Our in vitro studies indicated that at an MHM.23 concentration of 20 microg/ml, macaque PBMCs were completely saturated. Our in vivo studies determined that 5 mg/kg MHM.23 intravenously every 24 h was required to maintain saturating levels and inhibit LFA-1-ICAM-1 function in pig-tailed macaques.

A novel HIV-1 transgenic rat model of childhood HIV-1-associated nephropathy.

BACKGROUND: A characteristic finding of human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is the presence of heavy proteinuria, focal or global glomerulosclerosis, and microcystic tubular dilatation leading to renal enlargement, and rapid progression to end-stage renal disease (ESRD). METHODS: We have recently developed the first HIV-1 transgenic rat model that carry a noninfectious HIV-1 DNA construct lacking 3.1 kb of sequence overlapping the gag and pol sequences, and develop many of the clinical lesions seen in HIV-infected patients, including HIVAN. To gain further insight into the pathogenesis of childhood HIVAN, we followed the clinical and renal pathologic outcome of 165 HIV-1 transgenic (HIV-Tg) rats and their respective control littermates for a period of 18 months. RESULTS: HIV-1 Tg rats progressively developed proteinuria and renal histologic lesions similar to those seen in children with HIVAN, leading to chronic renal failure. By in situ hybridization, HIV-1 genes were detected in glomerular and tubular epithelial cells and infiltrating mononuclear cells, which also expressed the HIV-1 envelop protein gp120. The development of HIVAN was associated with the accumulation of basic fibroblast growth factor (bFGF) in the kidney. CONCLUSION: These data support the notion that HIV-1 plays a direct role in the pathogenesis of HIVAN, by affecting the function and growth of renal epithelial cells, inducing the recruitment of mononuclear cells, and accumulating bFGF in the kidney, even in the absence of viral replication. These rats may provide an excellent model system to study the pathogenesis of childhood HIVAN.

The association of MHC genes with autism.

Several immune abnormalities have been noted in autistic subjects. These associations have been extended to the Major Histocompatibility Complex (MHC), a section of DNA remarkable for the number of encoded proteins with immunological functions. The strongest MHC association identified thus far is for the null allele of C4B in the class III region. The complex allelic composition of C4 as determined by immunoelectrophoresis is discussed. Low levels of C4 resulting from the null allele may be important in disease pathogenesis especially since C4 has been identified in developing brain neurons. The DNA region just telomeric to C4 has several genes including tumor necrosis factor which encode proteins with immunological functions. These proteins may act in concert with C4 in disease contribution and the genes should be more closely examined.

Incidence of P-glycoprotein overexpression and multidrug resistance (MDR) reversal in adult soft tissue sarcoma.

Multidrug resistance (MDR) is a widespread problem in the treatment of neoplastic diseases and may limit the effectiveness of treatment of adult soft tissue sarcomas (STS). We examined the levels of expression of the MDR marker P-glycoprotein (Pgp) in fresh, surgical material and matched paraffin-embedded tissue using MRK-16 and JSB-1 monoclonal antibodies. Using fresh tumour material in short-term culture an assessment of doxorubicin sensitivity (MTT assay) and MDR modulation using PSC-833 in daunorubicin (DNR) accumulation experiments (FACS analysis) was carried out. 44 patients were studied at various disease stages with a mean follow-up duration of 487 days (range: 45-1095 days). Immunocytochemistry and immunohistochemistry showed 62% and 58%, respectively, of STS samples were positive for Pgp. Patients showing negative Pgp expression had a median survival of 544 days versus 431 days for Pgp-positive patients (P=0.311), with disease-free survival medians of 508 and 355 days, respectively (P=0.203). In vitro doxorubicin sensitivity was not informative in this respect and there was no apparent relationship between this and Pgp expression. Eleven out of 29 samples evaluated for MDR modulation showed enhanced tumour cell DNR accumulation. However, the effects of PSC-833 on drug accumulation in clinical material were modest compared with those seen for MDR cell lines, with a maximum of only 20% enhancement. Moreover, there was no relationship between the extent of PSC-833 effects on accumulation and the levels of Pgp seen in the STS samples. Nevertheless, we show evidence that a proportion of cases of STS express moderate to high levels of Pgp. There may be a role for MDR modulating agents in association with doxorubicin in the treatment of these tumours, either in the adjuvant setting or at first relapse.

Extra-articular synovial chondromatosis of the temporomandibular joint: pitfalls in diagnosis.

Synovial chondromatosis is a benign disease that only rarely affects the temporomandibular joint. When it does, disease is usually confined to the joint space itself but can occasionally extend beyond the joint capsule into the parotid gland, temporal bone, or cranium. The local clinical behavior, radiographic appearance, and histopathologic features can combine to create the appearance of a malignant lesion. We report a case of synovial chondromatosis that affected the temporomandibular joint and presented as an external auditory canal mass. The lesion was thought to be a chondrosarcoma prior to the definitive resection. Pitfalls in the diagnosis and management of synovial chondromatosis are discussed.

Phase I study of oral JM216 given twice daily.

JM216 [bis-acetato-ammine-dichloro-cyclohexylamine-platinum(IV)] is an oral platinum complex that is currently in phase II trials in ovarian cancer and lung cancer on a daily-times-5 schedule. This trial examined an alternative schedule of two doses given 12 h apart, which may be better tolerated by patients. A total of 19 patients were given 50 cycles of treatment at doses ranging from 150 to 350 mg/m2 b.i.d. The study was stopped before the MTD was reached due to non-linear pharmacokinetics. Toxicity was similar to that encountered in previous phase I studies, with nausea, vomiting and diarrhoea being seen at all dose levels, although this was generally mild and short-lived, and grade 3 and 4 myelosuppression being seen at dose levels ranging from 250 to 350 mg/m2. There was no nephro-, oto-, or neurotoxicity, but one patient had an allergic reaction at 300 mg/m2 on the fifth and sixth cycles. No response was seen, but two patients with mesothelioma had stable disease and received six cycles. There was considerable interpatient variability in plasma pharmacokinetics at all dose levels. There was no relationship between dose and AUC (dose 1 and dose 2) or Cmax after dose 1. In a limited number of patients the first dose was given in the morning rather than in the evening, apparently resulting in lower AUC, Cmax and Tmax values at the 250-mg/m2 dose level, but this was not seen in one patient at 300 mg/m2. This study confirms that the pharmacokinetics of JM216 is non-linear and highly variable due to saturable absorption and that the daily times 5 schedule is the optimal schedule for further phase II trials.

Influence of membrane anchoring and cytoplasmic domains on the fusogenic activity of vesicular stomatitis virus glycoprotein G.

Chimeric proteins in which the transmembrane anchoring sequence (TM) or both the TM and the cytoplasmic tail (CT) of vesicular stomatitis virus glycoprotein G were replaced with corresponding domains of viral or cellular integral membrane proteins were used to examine the influence of these domains on acidic-pH-induced membrane fusion by G protein. The TM and CT of G were also replaced with the lipid anchor glycosylphosphatidylinositol. Hybrids containing foreign TM or TM and CT sequences were fusogenic at acidic pH but glycosylphosphatidylinositol-anchored G was nonfusogenic at acidic pH. The results suggest that the fusogenic activity of G protein requires membrane anchoring by a hydrophobic peptide sequence and the specific amino acid sequence of the TM has no influence on fusogenic activity.

Intracellular metabolism of the orally active platinum drug JM216: influence of glutathione levels.

JM216 (bis-acetato ammine dichloro cyclohexylamine Pt IV) is an oral platinum complex presently undergoing phase II clinical trials. Previous studies have identified some of its biotransformation products in clinical materials. This study evaluated the nature of JM216 biotransformation products intracellularly in two different human ovarian carcinoma cell lines, one relatively sensitive to platinum agents (CH1: JM216 4 h IC50 of 5.8 microM) and the other relatively resistant (SKOV3: JM216 4 h IC50 of 60.7 microM). Metabolic profiles were also evaluated at different growth status and in cells pretreated with buthionine sulphoximine (BSO), an agent known to decrease intracellular glutathione levels. Results showed that JM216 enters the cells and that the nature and percentage of biotransformation products was dependent upon glutathione levels. Furthermore, results support the view that the previously reported peak A biotransformation product contains a glutathione adduct. In exponentially growing SKOV3 cells which contain higher glutathione levels than CH1, (82.5 vs 37.8 nmol mg-1 protein), peak A represented 89% of total platinum 4 h after JM216 exposure compared with only 24% in CH1. Moreover, 60-70% depletion of glutathione achieved by 24 h pretreatment of cells with BSO resulted in a significant decrease in peak A in both cell lines and increased the cytotoxicity of JM216 in both CH1 and SKOV3 by approximately 2-fold. Following a 4 h exposure of exponentially growing SKOV3 cells to JM216, only peak A (89%) and JM216 (11%) could be detected whereas in CH1 cells, peak A (24%), JM216 (73%) and JM118 [cis-ammine dichloro (cyclohexylamine) platinum II] (3%) were detected. However, in CH1 cells at confluence, where glutathione is lower (8 nmol mg-1 protein) four metabolites (plus JM216 itself) were detected following exposure to 50 microM JM216; peak A, JM118, JM383 (bis-acetato ammine (cyclohexylamine) dihydroxy platinum IV) and an unidentified metabolite (D), also observed in patient's plasma ultrafiltrate. In confluent SKOV3 cells exposed to 50 microM JM216, peak A, JM216 and JM118 were detected. A further unidentified metabolite observed in patients receiving JM216 (metabolite F) was not formed inside these tumour cells. Overall, these data suggest that glutathione conjugation represents a major deactivation pathway for JM216.