Pathogenic mechanism of an autism-associated neuroligin mutation involves altered AMPA-receptor trafficking.

Neuroligins are postsynaptic cell-adhesion molecules that bind to presynaptic neurexins. Although the general synaptic role of neuroligins is undisputed, their specific functions at a synapse remain unclear, even controversial. Moreover, many neuroligin gene mutations were associated with autism, but the pathophysiological relevance of these mutations is often unknown, and their mechanisms of action uninvestigated. Here, we examine the synaptic effects of an autism-associated neuroligin-4 substitution (called R704C), which mutates a cytoplasmic arginine residue that is conserved in all neuroligins. We show that the R704C mutation, when introduced into neuroligin-3, enhances the interaction between neuroligin-3 and AMPA receptors, increases AMPA-receptor internalization and decreases postsynaptic AMPA-receptor levels. When introduced into neuroligin-4, conversely, the R704C mutation unexpectedly elevated AMPA-receptor-mediated synaptic responses. These results suggest a general functional link between neuroligins and AMPA receptors, indicate that both neuroligin-3 and -4 act at excitatory synapses but perform surprisingly distinct functions, and demonstrate that the R704C mutation significantly impairs the normal function of neuroligin-4, thereby validating its pathogenicity.

A comparative immunological analysis of CoCl2 treated cells with in vitro hypoxic exposure.

The hypoxic preconditioning of mammalian cells has been shown to have beneficial effects against hypoxic injuries. However, very little information is available on the comparative analysis of immunological responses to hypoxic and hypoxia mimetic exposure. Therefore, in the present study, mouse peritoneal macrophages and splenocytes were subjected to hypoxia exposure (0.5 % O2) and hypoxia mimetic Cobalt chloride (CoCl2) treatment to evaluate their effect on immune response and delineate the underlying signaling mechanisms. The results obtained indicated that super oxide generation increased while TLR4 expression and cell surface markers like CD25, CD40 and CD69 were suppressed in both the treatments as compared to normoxia. Cobalt chloride treatment increased NF-κB expression, nitric oxide (NO) and iNOS expression, cytokines TNF-α and IL-6 as compared to hypoxia exposure. Our study showed that CoCl2 stabilizes HIF-1α to create hypoxia like conditions but it mainly influences the inflammatory response via NF-κB signaling pathway by skewing the production of proinflammatory molecules like TNF-α, IL-6 and NO.

Metabolic syndrome is a risk factor for development of heart failure in acute myocardial infarction.

There is a relationship between metabolic syndrome with heart failure. A case control study was designed to see the association of metabolic syndrome with heart failure. The study was conducted from August 2009 to May 2010. Hundred cases were selected as study population which was taken from Department of Cardiology Mymensingh Medical College, Mymensingh. Among them 50 were in Group A, 50 were in Group B. Group A was the patient with acute myocardial infarction (AMI) with metabolic syndrome. Group B was the patient with AMI without metabolic syndrome. It revealed that 23(46%) in Group A and 10 (20%) in Group B developed heart failure. Which is statistically significant (p<0.05). The study concluded that metabolic syndrome is significantly associated with heart failure.

Long-term survival in an un-operated single ventricle.

Single ventricle is a rare and complex congenital heart disease. Neonates with single ventricle have a high mortality. Survival into adulthood is rare without surgical intervention. A case of single ventricle with double inlet and double outlet combined with severe valvular pulmonary stenosis and mitral regurgitation (Grade II) is being reported here. A 36 years old man was admitted for bluish discoloration of lips, tongue and fingers; shortness of breath and recurrent palpitation. His ECG showed atrial fibrillation with fast ventricular rate. Chest X-Ray depicted an enlarged cardiac shadow and right sided pleural effusion. Final diagnosis was made by echocardiogram which demonstrated single ventricle with double inlet and double outlet, severe valvular pulmonary stenosis and mitral regurgitation (Grade II) with good ventricular systolic function.

Disseminated tuberculosis presenting as acute coronary syndrome.

Tuberculosis is a major public health problem in Bangladesh. Though tuberculosis is common but acute myopericarditis can rarely be caused by tuberculosis infection. A case of disseminated tuberculosis presenting with features of acute coronary syndrome is presenting here. A 26 years old man was admitted for severe central chest pain for 2 days and fever for 2 months. His ECG showed ST segment elevation in chest leads, V1 to V4 with elevated Troponin I and high ESR. Chest X-Ray depicted an enlarged cardiac shadow. Echocardiography demonstrated multiple dynamic cavitary lesions involving interventricular septum as well as anterior wall of the left ventricle within myocardium with moderate pericardial effusion with trivial mitral regurgitation. A CT scan of chest with contrast revealed multiple calcific communicating cavities within endocardium and myocardium involving interventricular septum and anterior wall of the left ventricle of heart and multiple cavitary lesions in the mid zone of left lung with bilateral mild pleural effusion. The patient made an excellent recovery on management of acute coronary syndrome and on antitubercular therapy.

A case report of right ventricular mass.

Primary Cardiac tumors are uncommon during infancy and childhood. Myxomas originating in the right ventricles are even less common in paediatric patient. Our patient baby Rani, 3 months of age presented with shortness of breath and chest indrawing. Antenatal history and delivery was uneventful. The baby was under weight and also malnourished but there was no cyanosis and clubbing. Her respiratory rate was 25/minute. On precordium examination, first heart sound (S1) was normal but pulmonary component of second heart sound (P2) was soft. There was an ejection systolic murmur (Grade-3/6) in the left upper para-sternal area. Chest X-ray revealed cardiomegaly. Echocardiogram revealed a large mass (11x10mm) in the right ventricle, dynamically obstructing the right ventricular out-flow tract and compressing the left ventricle. There was a Tricuspid regurgitation (Grade-2) and moderate pulmonary hypertension (PASP-50 mmHg).

Effect of Seabuckthorn (Hippophae rhamnoides) flavone on immune system: an in-vitro approach.

There are several reports, which suggest that the consumption of foods rich in flavonoids is associated with a lower incidence of certain degenerative diseases, including cardiovascular disease. Flavones, of Seabuckthorn (SBT) (Hippophae rhamnoides L.) fruit berry can modulate the production and level of several signaling molecules associated with immune function and inflammation in vitro, including several cytokines. We have evaluated the immunomodulatory activity of ethanolic solution of SBT flavone (FLV) in human peripheral blood mononuclear cells (PBMCs). The SBT flavone was found to stimulate production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in PBMCs. However, increased expressions of p-IkappaB, NF-kappaB, and p-p38 were found in flavone-treated human PBMCs with significantly suppressed expression of CD25 (IL-2R). There was no alteration found in the nitric oxide (NO) production in mouse macrophage cell line RAW 264.7. These observations suggest that stimulation of IL-6 and TNF-alpha secretion may contribute to the putative beneficial effects of dietary flavone against microbial infection.

Antibacterial and preliminary phytochemical and physico-chemical analysis of Eucalyptus citriodora Hk leaf.

The present communication deals with some studies on the antibacterial, physico-chemical and phytochemical parameters of different extracts of Eucalyptus citriodora leaf. The antibacterial study was performed using the agar ditch method on some clinically important bacteria, namely Pseudomonas pseudoalcaligenes, Proteus vulgaris, Citrobacter freundii, Staphylococcus subflava, Bacillus megaterium, and Enterobacter aerogenes. Physico-chemical parameters namely water, methanol, 1,4-dioxane, DMF, acetone soluble extractives, total ash, melting point, and pH were determined according to pharmacopoeial procedures. Methanol gave the maximum extract while it was minimum in water. Phytochemical parameters were screened for alkaloids, tannins, cardiac glycosides, saponins, steroids and flavonoids. Tannins and flavonoids gave positive results, while steroids and glycosides were absent. The most susceptible bacteria was C. freundii, while the most resistant was P. vulgaris.

Phoenix sylvestris Roxb pollen allergy: a 2-year randomized controlled trial and follow-up study of immunotherapy in patients with seasonal allergy in an agricultural area of West Bengal, India.

BACKGROUND: Although the efficacy of allergen immunotherapy has been demonstrated in seasonal pollen allergy, there is no report of a double-blind placebo-controlled trial with standardized pollen extract in seasonal respiratory allergy from India. In the agricultural area of eastern India, Phoenix sylvestris Roxb or date sugar palm is grown or cultivated and seasonal allergic rhinitis is common during the pollen season. OBJECTIVE: The objective of the present study was to observe the clinical and immunological changes during a 2-year double-blind placebo-controlled trial of immunotherapy with standardized P sylvestris pollen extract in respiratory patients sensitive to pollen from this wild date palm. Thirty-five subjects with typical seasonal allergic rhinitis with or without bronchial asthma were selected. A symptom-medication score (based on a questionnaire and diary) was correlated with pollen counts as recorded in a Burkard sampler. Eighteen subjects were randomized to a specific immunotherapy (SIT) group receiving regular injections containing standardized allergen extract and 17 to a placebo control group. Changes in the level of specific immunoglobulin (Ig) E, IgG1, and IgG4 were recorded at 3-month intervals. Measurement of wheal diameter, total IgE level and forced expiratory volume in 1 second (FEV1) were performed before starting and a month after finishing therapy. RESULTS: The SIT group showed decreases of 33.5% and 57% from the baseline symptom-medication scores during the first and second treatment season, respectively. This group showed significant decreases in skin-reactivity to P sylvestris pollen extract and in specific IgE levels, and significant increases in FEV,, specific IgGI (1.95-3.2 times higher) and IgG4 (21.24-30.83 times higher). There were no significant changes in total IgE levels. The control group showed no significant changes for any parameter except the development of new sensitization in 2 cases (to Saccharum officinarum pollen grain and Alternaria species spores). The rate of local adverse reactions was 0.024%. CONCLUSION: After a 2-year study, allergen immunotherapy with standardized P sylvestris pollen extract was found to be effective in seasonal respiratory allergic subjects susceptible to P sylvestris pollen with a narrow range of sensitization.

Crisaborole and its potential role in treating atopic dermatitis: overview of early clinical studies.

Atopic dermatitis (AD), a chronic, relapsing, inflammatory skin disease that is characterized by intense pruritus and eczematous lesions with up to 90% of patients presenting with mild to moderate disease. Current topical treatments for AD have not changed in over 15 years and are associated with safety concerns. In AD, overactivity of phosphodiesterase 4 (PDE4), leads to inflammation and disease exacerbation. Crisaborole Topical Ointment, 2%, is a novel, nonsteroidal, topical anti-inflammatory PDE4 inhibitor currently being investigated for the treatment of mild to moderate AD. Preliminary studies in children and adults demonstrated favorable efficacy and safety profiles. Crisaborole may represent an anti-inflammatory option that safely minimizes the symptoms and severity of AD and that can be used for both acute and long-term management.

Histochemical evaluation of catechins in PEG stressed transgenic tea plants using catechin-specific-diazotized sulfanilamide reagent.

We investigated the applicability of catechin-specific-reagent (CSR) for histochemical evaluation of catechins. The diazotized arylamine moiety in CSR reacts specifically with the A-ring of catechins to yield a golden yellow complex. This makes it highly specific for spectrophotometric quantification of catechins. Therefore, microtome cut sections of untransformed and osmotin-expressing transgenic leaves and stem of tea were stained with CSR. We found catechins in the form of golden yellow globules. The catechin globules increased in the structurally intact and highly turgid cells of osmotin expressing transgenic tea plants after stress treatment with 20% PEG; by contrast, the cells in non-transgenic plants accumulated fewer catechin globules. Spectrophotometric quantification of catechins also confirmed higher levels in transgenics compared to untransformed plants. We found elevated accumulation of catechins in stress tolerant cells of tea leaves.

Molecular characterisation of Aspergillus flavus isolates from peanut fields in India using AFLP.

Aflatoxin contamination of peanut, due to infection by Aspergillus flavus, is a major problem of rain-fed agriculture in India. In the present study, molecular characterisation of 187 Aspergillus flavus isolates, which were sampled from the peanut fields of Gujarat state in India, was performed using AFLP markers. On a pooled cluster analysis, the markers could successfully discriminate among the 'A', 'B' and 'G' group A. flavus isolates. PCoA analysis also showed equivalent results to the cluster analysis. Most of the isolates from one district could be clustered together, which indicated genetic similarity among the isolates. Further, a lot of genetic variability was observed within a district and within a group. The results of AMOVA test revealed that the variance within a population (84%) was more than that between two populations (16%). The isolates, when tested by indirect competitive ELISA, showed about 68.5% of them to be atoxigenic. Composite analysis between the aflatoxin production and AFLP data was found to be ineffective in separating the isolate types by aflatoxigenicity. Certain unique fragments, with respect to individual isolates, were also identified that may be used for development of SCAR marker to aid in rapid and precise identification of isolates.

Tavaborole topical solution, 5% for the treatment of toenail onychomycosis.

Tavaborole topical solution, 5% (tavaborole) is a novel, boron-based, antifungal pharmaceutical agent indicated for treatment of toenail onychomycosis due to the dermatophytes Trichophyton rubrum or Trichophyton mentagrophytes. In preclinical studies, tavaborole effectively penetrated through full-thickness, non-diseased cadaver fingernails, including those with up to four layers of nail polish. Limited systemic absorption was observed following topical application of tavaborole. In phase III clinical trials involving patients with distal subungual onychomycosis affecting 20-60% of a target great toenail, significantly more patients treated with tavaborole versus vehicle achieved completely clear nail with negative mycology following daily application for 48 weeks. Treatment-emergent adverse events reported by at least 1% of patients treated with tavaborole and at a greater frequency versus vehicle included ingrown toenail, exfoliation, erythema and dermatitis. Treatment discontinuations were uncommon. Results from preclinical studies and phase III clinical trials establish tavaborole as a safe and efficacious treatment for toenail onychomycosis.

Transcriptional repression of IFNß1 by ATF2 confers melanoma resistance to therapy.

The resistance of melanoma to current treatment modalities represents a major obstacle for durable therapeutic response, and thus the elucidation of mechanisms of resistance is urgently needed. The crucial functions of activating transcription factor-2 (ATF2) in the development and therapeutic resistance of melanoma have been previously reported, although the precise underlying mechanisms remain unclear. Here, we report a protein kinase C-ɛ (PKCɛ)- and ATF2-mediated mechanism that facilitates resistance by transcriptionally repressing the expression of interferon-ß1 (IFNß1) and downstream type-I IFN signaling that is otherwise induced upon exposure to chemotherapy. Treatment of early-stage melanomas expressing low levels of PKCɛ with chemotherapies relieves ATF2-mediated transcriptional repression of IFNß1, resulting in impaired S-phase progression, a senescence-like phenotype and increased cell death. This response is lost in late-stage metastatic melanomas expressing high levels of PKCɛ. Notably, nuclear ATF2 and low expression of IFNß1 in melanoma tumor samples correlates with poor patient responsiveness to biochemotherapy or neoadjuvant IFN-α2a. Conversely, cytosolic ATF2 and induction of IFNß1 coincides with therapeutic responsiveness. Collectively, we identify an IFNß1-dependent, cell-autonomous mechanism that contributes to the therapeutic resistance of melanoma via the PKCɛ-ATF2 regulatory axis.

Tissue repair response as a function of dose in thioacetamide hepatotoxicity.

The purpose of the present study was to establish a dose-response relationship for thioacetamide (TA), where tissue regeneration as well as liver injury were two simultaneous but opposing responses. Male Sprague-Dawley rats were injected intraperitioneally with a 12-fold dose range of TA, and both liver injury and tissue repair were measured. Liver injury was assessed by serum enzyme elevations. Serum alanine aminotransferase (ALT) elevation did not show any dose response over a 12-fold dose range up to 24 hr. A dramatic ALT elevation was evident after 24 hr and only for the highest dose (600 mg/kg). Tissue regeneration response was measured by 3H-thymidine (3H-T) incorporation into hepatocellular DNA and by proliferating cell nuclear antigen (PCNA) procedure during a time course (6, 12, 24, 36, 48, 72, and 96 hr). Tissue regeneration, as indicated by 3H-T incorporation, peaked at 36 hr after administration of a low dose of TA (50 mg/kg). With increasing doses, a greater but delayed stimulation of cell division was observed until a threshold was reached (300 mg/kg). Above the tissue repair threshold (600 mg/kg), because stimulated tissue repair as revealed by 3H-T incorporation in hepatonuclear DNA was significantly delayed and attenuated, injury assessed by serum enzyme elevations was remarkably accelerated, indicating unrestrained progression of injury leading to animal death. These findings suggest that, in addition to the magnitude of tissue repair response, the time at which this occurs is critical in restraining the progression of injury, thereby determining the ultimate outcome of toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Age- and gender-related differences in sensitivity to chlorpyrifos in the rat reflect developmental profiles of esterase activities.

Young rats are more sensitive than adults to a single oral dose of chlorpyrifos, an organophosphorus pesticide. A direct comparison of chlorpyrifos effects in young (postnatal day 17; PND17), adolescent (PND27), and adult (70 days) Long-Evans rats was conducted to determine quantitative and possibly qualitative differences in sensitivity in terms of behavioral changes and cholinesterase (ChE; total cholinesterase activity) inhibition at these three ages. Male and female rats were administered chlorpyrifos orally at one of two doses (PND17, 5 or 20 mg/kg; PND27, 20 or 50 mg/kg; adult, 20 or 80 mg/kg) and tested at either 3.5 or 6.5 h after dosing. Behavioral testing included observational evaluations and measurements of motor activity and was followed immediately by tissue collection for ChE determination in brain and blood. For both behavioral changes and ChE inhibition, peak effects occurred at 3.5 h in adult male and PND27 rats (both sexes) and at 6.5 h in adult female and PND17 rats (both sexes). Comparisons of the 20 mg/kg dose across ages showed generally less ChE inhibition and fewer behavioral effects with increasing age, except that the adult females were similar to the PND27 rats. The high dose used for each age group produced similar brain ChE inhibition (80-90%) and generally similar behavioral effects. Interestingly, a few end-points in the young rats were less affected than in adults at this level of ChE inhibition. The degree of ChE inhibition in the brain more closely paralleled the blood inhibition in the younger rats, compared to the adults. Carboxylesterase (CaE) and A-esterase are known to play an important role in the detoxification of organophosphates and may be partially responsible for these sensitivity differences. Liver and plasma CaE and A-esterase activities were measured in untreated male rats on PND1, 4, 7, 12, 17, and 21 and in adults of both sexes (82-92 days old). Preweanling rats had considerably less activity of both enzymes, and adult females had less liver CaE activity than males. These differences in detoxifying enzymes correlate with the age-related differences in behavioral and biochemical effects, as well as the gender differences seen in adult rats, and thus may be a major influence on the differential sensitivity to chlorpyrifos.

Disposition of inhaled mercury vapor in pregnant rats: maternal toxicity and effects on developmental outcome.

The disposition and toxicity of inhaled elemental mercury (Hg0) vapor for pregnant Long-Evans rats, and potential adverse effects on reproductive outcome were investigated. Rats were exposed to 0, 1, 2, 4, or 8 mg Hg0/m(3) for 2 h/day from gestation day (GD) 6 through GD 15. Maternal toxicity occurred primarily in rats exposed to 4 and 8 mg/m(3) and was manifested as a concentration-related decrease in body weight gain and mild nephrotoxicity. Control rats gained about 13% of their initial body weight during the 10-day exposure. Rats exposed to 4 mg/m(3) Hg0 gained about 7% less than controls, and rats exposed to 8 mg/m(3) Hg0 lost about 17% of their initial body weight during the 10-day exposure period. Maternal kidney weights were significantly increased in the 4 and 8 mg/m(3) concentration groups, and urinalysis revealed increased levels of protein and alkaline phosphatase activity in urine of all Hg0-exposed rats. Dams exposed to 8 mg/m(3) were euthanized in moribund condition on postnatal day (PND) 1. There was no histopathological evidence of toxicity in maternal lung, liver, or kidney of exposed rats at GD 6, GD 15, or PND 1. The incidence of resorptions was significantly increased, litter size and PND 1 neonatal body weights were significantly decreased only in the 8-mg/m(3) group. Total Hg concentrations in maternal tissues increased with increasing number of exposure days and concentration. In general, approximately 70% of Hg was eliminated from maternal tissues during the week following the last exposure (GD 15 to PND 1). Elimination of Hg from maternal brain and kidney was slower than in other tissues, possibly due to higher levels of metallothionein. Total Hg concentrations in fetal tissues increased with increasing number of exposure days and concentration, demonstrating that a significant amount of Hg crossed the placenta. One week after the last exposure, significant amounts of Hg were still present in brain, liver, and kidney of PND 1 neonates. Metallothionein levels in neonatal tissues were not significantly increased by exposure to 4 mg/m(3) Hg0. The total amount of Hg in neonatal brain (ng/brain) continued to increase after termination of inhalation exposure, suggesting a redistribution of Hg from the dam to neonatal brain. These data demonstrate that inhaled Hg0 vapor is distributed to all maternal and fetal tissues in a dose-dependent manner. Adverse effects of Hg on developmental outcome occurred only at a concentration that caused maternal toxicity.

Cocaine and D-amphetamine induce changes in central beta-adrenoceptor sensitivity: effects of acute and chronic drug treatment.

The effects of acute and chronic treatment with psychomotor stimulants on specific binding of [3H]dihydroalprenolol to beta-adrenoceptors in rat brain were examined. At a dose of 10 mg/kg both acute and chronic treatment with cocaine and chronic treatment with D-amphetamine (10 mg/kg) caused increased binding of [3H]dihydroalprenolol. The molecular mechanism for this enhanced binding appears to be augmentation of the density of beta-adrenoceptors in rat brain. At a lower dose (5 mg/kg), however, chronic administration of D-amphetamine caused a decrease in the density of beta-adrenoceptors in rat brain. Chronic treatment with either D-amphetamine (10 mg/kg) or cocaine induced a marked increase in the magnitude of cyclic AMP accumulation in rat brain slices elicited by norepinephrine. Acute as well as chronic administration of D-amphetamine in vivo inhibited the temperature-dependent uptake of [3H]norepinephrine in rat brain synaptosomal homogenates, but no such inhibition was observed after chronic or acute treatment with cocaine. The results suggest that psychomotor stimulants induce beta-adrenoceptor supersensitivity which may be involved in the phenomenon of reverse tolerance and possibly psychosis in humans. The development of beta-adrenoceptor supersensitivity does not appear to be mediated through alterations in norepinephrine transport at the presynaptic sites.

Role of nutrition in the survival after hepatotoxic injury.

Nutritional status is an important factor in determining susceptibility to toxic chemicals. While macro and micronutrients may affect many aspects of Stage I and Stage II of toxicity, in this paper, the influence of macronutrients as sources of energy required for cell division and tissue repair mechanisms on the outcome of hepatic injury is discussed. Male Sprague-Dawley rats maintained on normal rodent chow and 15% glucose (as a source of energy for the centrilobular hepatocytes) in drinking water for 7 days experienced an increased lethality from structurally and mechanistically different centrilobular hepatotoxicants (acetaminophen, thioacetamide, chloroform and carbon tetrachloride), while male Sprague-Dawley (S-D) rats fed rat chow containing palmitic acid (PA, 8% w/w, as a source of energy for the periportal hepatocytes) and L-carnitine (LC, 2 mg/ml, as a mitochondrial carrier for the supplemented fatty acids) in drinking water for 7 days were protected from a LD100 dose (600 mg/kg, i.p.) of thioacetamide (TA). Indices of cell division revealed that cell cycle progression in the liver played a very critical role in determining the final outcome of hepatotoxic injury. These results confirmed our hypothesis that cell division and tissue repair play a critical role in survival after life-threatening hepatotoxic injury. Any manipulation directed towards altering a prompt and exacting compensatory cell division and tissue repair responses after hepatotoxic injury would also alter the final outcome of the toxicity. These studies indicate that the source of cellular energy can decisively influence the compensatory response of the target tissue to alter the outcome of hepatotoxic injury. Since nutritional status is known to vary widely among human populations, these could contribute enormously to susceptibility of human populations to toxic chemicals.