Downregulation of major histocompatibility complex antigens in invading glioma cells: stealth invasion of the brain

Invasion into surrounding brain tissue is a fundamental feature of gliomas and the major reason for treatment failure. The process of brain invasion in gliomas is not well understood. Differences in gene expression and/or gene products between invading and noninvading glioma cells may identify potential targets for new therapies. To look for genes associated with glioma invasion, we first employed Affymetrix microarray Genechip technology to identify genes differentially expressed in migrating glioma cells in vitro and in invading glioma cells in vivo using laser capture microdissection. We observed upregulation of a variety of genes, previously reported to be linked to glioma cell migration and invasion. Remarkably, major histocompatiblity complex (MHC) class I and II genes were significantly downregulated in migrating cells in vitro and in invading cells in vivo. Decreased MHC expression was confirmed in migrating glioma cells in vitro using RT-PCR and in invading glioma cells in vivo by immunohistochemical staining of human and murine glioblastomas for beta2 microglobulin, a marker of MHC class I protein expression. To the best of our knowledge, this report is the first to describe the downregulation of MHC class I and II antigens in migrating and invading glioma cells, in vitro and in vivo, respectively. These results suggest that the very process of tumor invasion is associated with decreased expression of MHC antigens allowing glioma cells to invade the surrounding brain in a 'stealth'-like manner.     

Immune Responses to the O-Specific Polysaccharide Antigen in Children Who Received a Killed Oral Cholera Vaccine Compared to Responses following Natural Cholera Infection in Bangladesh

Current oral cholera vaccines induce lower levels of protective efficacy and shorter durations of protection in young children than in adults. Immunity against cholera is serogroup specific, and immune responses to Vibrio cholerae lipopolysaccharide (LPS), the antigen that mediates serogroup-specific responses, are associated with protection against disease. Despite this, responses against V. cholerae O-specific polysaccharide (OSP), a key component of the LPS responsible for specificity, have not been characterized in children. Here, we report a comparison of polysaccharide antibody responses in children from a region in Bangladesh where cholera is endemic, including infants (6 to 23 months, n = 15), young children (24 to 59 months, n = 14), and older children (5 to 15 years, n = 23) who received two doses of a killed oral cholera vaccine 14 days apart. We found that infants and young children receiving the vaccine did not mount an IgG, IgA, or IgM antibody response to V. cholerae OSP or LPS, whereas older children showed significant responses. In comparison to the vaccinees, young children with wild-type V. cholerae O1 Ogawa infection did mount significant antibody responses against OSP and LPS. We also demonstrated that OSP responses correlated with age in vaccinees, but not in cholera patients, reflecting the ability of even young children with wild-type cholera to develop OSP responses. These differences might contribute to the lower efficacy of protection rendered by vaccination than by wild-type disease in young children and suggest that efforts to improve lipopolysaccharide-specific responses might be critical for achieving optimal cholera vaccine efficacy in this younger age group.     

Goat semen cryopreservation with rainbow trout seminal plasma supplemented lecithin-based extenders

The objective of this study was to determine the optimum concentrations of rainbow trout seminal plasma (RTS) supplemented extenders for goat semen quality at post-thaw and after incubation. Five sexually mature Saanen goat (Capra aegagrus hircus) were used for semen collection. Pooled semen was diluted with soybean lecithin-based extender without RTS (control) or supplemented with different concentrations of RTS (1%, 2%, 4% or 8%), at a final concentration of 150 × 10⁶ spermatozoon/ml. Sperm motility, plasma membrane functional integrity (HOST), damaged acrosome (PSA-FITC), mitochondrial activity (rhodamine123) and DNA integrity (TUNEL) were evaluated. Spermatological parameters were evaluated at post-thaw and after 6 hr incubation. RTS8 group preserved sperm motility, acrosomal integrity, plasma membrane functional integrity and mitochondrial function better than the control group (p < .05). The study demonstrated that RTS supplemented lecithin-based extenders have useful effects on goat spermatozoa. In addition, the results of the current study represented the positive effect of using 8% RTS supplemented extender.     

Chemical,Pharmacological and Computerized Molecular Analysis of Stem’s Extracts of Bauhinia scandens L. Provide Insights into the Management of Diarrheal and Microbial Infections

Bauhinia scandens L. (Family: Fabaceae) is commonly used to treat cholera, diarrhea, asthma, and diabetes disorder in integrative medicine. This study aimed to screen the presence of phytochemicals (preliminary and UPLC-QTOF–M.S. analysis) and to examine the pharmacological activities of Bauhinia scandens L. stems (MEBS) stem extracts. Besides, in silico study was also implemented to elucidate the binding affinity and drug capability of the selected phytochemicals. In vivo anti diarrheal activity was investigated in mice models. In vitro, antibacterial and antifungal properties of MEBS against several pathogenic strains were evaluated using the disc diffusion method. In addition, in silico study has been employed using Discovery studio 2020, UCFS Chimera, PyRx autodock vina, and online tools. In the anti-diarrheal investigation, MEBS showed a significant dose-dependent inhibition rate in all three methods. The antibacterial and antifungal screening showed a remarkable zone of inhibition, of the diameter 14–26 mm and 12–28 mm, by MEBS. The present study revealed that MEBS has remarkable anti-diarrheal potential and is highly effective in wide-spectrum bacterial and fungal strains. Moreover, the in silico study validated the results of biological screenings. To conclude, MEBS is presumed to be a good source in treating diarrhea, bacterial and fungal infections.     

Clinical features and prognosis with Guillain-Barr�� syndrome

Background:

Guillain-Barré syndrome (GBS) is an acute inflammatory polyneuropathy commonly characterized by rapidly progressive, symmetric weakness and areflexia.

Materials and Methods:

We retrospectively assessed the clinical manifestations, results of electrodiagnostic tests, functional status and prognosis of 36 children diagnosed with GBS.

Results:

Based on clinical and electrophysiological findings, the patients were classified as having acute inflammatory demyelinating polyradiculoneuropathy (AIDP) (n = 25), acute motor axonal neuropathy (AMAN) (n = 10) and acute motor-sensory axonal neuropathy (AMSAN) (n = 1). Twenty (55.5%) patients were males and 16 (44.5%) patients were females. The mean age of the 36 patients was 68.1 ± 45.01 months (range, 6–180 months). Five (13.8%) patients were younger than 2 years. The most common initial symptoms were limb weakness, which was documented in 34 (94.4%) patients. In our study, 18 patients (51.4%) showed albuminocytological dissociation (raised protein concentration without pleocytosis) on cerebrospinal fluid (CSF) examination. Three patients (8.3%) required mechanical ventilation therapy during hospitalization. Unfortunately, three (8.3%) patients died; one patient had AIDP and two patients had axonal involvement (one case was AMAN and another case was AMSAN). When we compared the cases of residual sequel/dead and cases of complete recovery for neural involvement type including AIDP, AMAN and AMSAN, we did not find a statistically significant difference between the groups (P > 0.05).

Conclusion:

Our findings showed that cases of GBS was not uncommon in children younger than 2 years of age, and CSF protein level might be found high in the first week of the disease in about one half of the patients, with a higher rate of morbidity and mortality in patients with axonal involvement than in those with AIDP.     

Hypoxia-inducible factor 1 and VEGF upregulate CXCR4 in glioblastoma: implications for angiogenesis and glioma cell invasion

Hypoxia and hypoxia-inducible factor-1 (HIF-1) play a critical role in glioblastoma multiforme (GBMs). CXCR4 is involved in angiogenesis and is upregulated by HIF-1alpha. CXCR4 is a chemokine receptor for stromal cell-derived factor-1 (SDF-1)alpha, also known as CXCL12. We hypothesized that CXCR4 would be upregulated by hypoxia in GBMs. First, we investigated the expression of HIF-1alpha and CXCR4 in GBMs. CXCR4 was consistently found colocalized with HIF-1alpha expression in pseudopalisading glioma cells around areas of necrosis. In addition, angiogenic tumor vessels were strongly positive for CXCR4. Next, we tested the in vitro effect of hypoxia and vascular endothelial growth factor (VEGF) on the expression of CXCR4 in glioma cell lines and in human brain microvascular endothelial cells (HBMECs). Exposure to hypoxia induced significant expression of CXCR4 and HIF-1alpha in glioma cells, whereas treatment with exogenous VEGF increased CXCR4 expression in HBMECs. We also transfected U87MG glioma cells with an HIF-1alpha construct and observed that CXCR4 was upregulated in these cells even in normoxic conditions. We then used a lentivirus-mediated shRNA expression vector directed against HIF-1alpha. When exposed to hypoxia, infected cells failed to show HIF-1alpha and CXCR4 upregulation. We performed migration assays under normoxic and hypoxic conditions in the presence or absence of AMD3100, a CXCR4 inhibitor. There was a significant increase in the migration of U87MG and LN308 glioma cells in hypoxic conditions, which was inhibited in the presence of AMD3100. These studies demonstrate the critical role played by hypoxia and CXCR4 in glioma cell migration. Based on these studies, we suggest that hypoxia regulates CXCR4 in GBMs at two levels. First, through HIF-1alpha in the pseudopalisading tumor cells themselves and, secondly, by the VEGF-stimulated angiogenic response in HBMECs. We believe this knowledge may lead to a potentially important two-pronged therapy against GBM progression using chemotherapy targeting CXCR4.