Melatonin integrates multidimensional regulation of Na+/K+-ATPase in ionocytes and promotes stress and ease response in hypoxia-induced air-breathing fish: lessons from integrative approach.

As circadian regulator, melatonin is involved in many physiological processes including ionosmotic regulation in fishes. Na+/K+-ATPase (NKA), an ubiquitous Na+/K+ transporter in ionocyte epithelia that drives electrochemical Na+ gradients and systemic osmotic integration, is a target of stress in fish. However, it is not certain how melatonin regulates NKA functions in ionocyte epithelia and how it modulates the adaptive response such as stress and ease response in fish particularly in hypoxia condition. We, thus, examined the short-term in vivo action of melatonin on the dynamics of NKA regulation in branchial, renal and intestinal ionocytes of hypoxia-induced air-breathing fish (Anabas testudineus Bloch). Interestingly, we found a rise in plasma melatonin in fish when kept for 30 min of forced submergence in water and that indicates a role for melatonin in hypoxia tolerance. A fall in blood [Na+ , K+] occurred in these hypoxic fish which later showed a recovery after melatonin treatment. Similarly, melatonin favored the fall in NKA activity in branchial and renal epithelia of hypoxic fish, though it remarkably stimulated its activities in non-stressed fish. Likewise, melatonin that produced differential pattern of mRNA expression in nkaα1-subunit isoforms (nkaα1a, nkaα1b and nkaα1c) and melatonin receptor isoforms (mtnr1a, mtnr1bb, mtnr1bb x1x2 ) in the tested ionocyte epithelia, showed reversed expression in hypoxic fish. In addition, the rise in NKAα-protein abundance in branchial and renal epithelia of melatonin-treated hypoxic fish indicated a recovery action of melatonin. A higher NKAα-immunoreactivity was found in the immunohistochemical and immunofluorescent images of branchial ionocytes and renal proximal and distal ionocytes of hypoxic fish treated with melatonin. Furthermore, an activation of PKA and PKG-dependent phosphorylation was found in branchial epithelia of hypoxic fish. The generated integrative parabola model showed that melatonin has a maximum targeted action on NKA function in the renal epithelia, suggesting its lead role in the integration of ionosmotic balance during the recovery or ease response. Over all, the data indicate a multidimensional and preferential action of melatonin on NKA regulation in fish ionocytes that integrate the recovery action against hypoxia, thus pointing to a major role for melatonin in stress and ease response in this fish.

Zymosan-induced immune challenge modifies the stress response of hypoxic air-breathing fish (Anabas testudineus Bloch): Evidence for reversed patterns of cortisol and thyroid hormone interaction, differential ion transporter functions and non-specific immune response.

Fishes have evolved physiological mechanisms to exhibit stress response, where hormonal signals interact with an array of ion transporters and regulate homeostasis. As major ion transport regulators in fish, cortisol and thyroid hormones have been shown to interact and fine-tune the stress response. Likewise, in fishes many interactions have been identified between stress and immune components, but the physiological basis of such interaction has not yet delineated particularly in air-breathing fish. We, therefore, investigated the responses of thyroid hormones and cortisol, ion transporter functions and non-specific immune response of an obligate air-breathing fish Anabas testudineus Bloch to zymosan treatment or hypoxia stress or both, to understand how immune challenge modifies the pattern of stress response in this fish. Induction of experimental peritonitis in these fish by zymosan treatment (200ngg-1) for 24h produced rise in respiratory burst and lysozomal activities in head kidney phagocytes. In contrast, hypoxia stress for 30min in immune-challenged fish reversed these non-specific responses of head kidney phagocytes. The decline in plasma cortisol in zymosan-treated fish and its further suppression by hypoxia stress indicate that immune challenge suppresses the cortisol-driven stress response of this fish. Likewise, the decline in plasma T3 and T4 after zymosan-treatment and the rise in plasma T4 after hypoxia stress in immune-challenged fish indicate a critical role for thyroid hormone in immune-stress response due to its differential sensitivity to both immune and stress challenges. Further, analysis of the activity pattern of ion-dependent ATPases viz. Na+/K+-ATPase, H+/K+-ATPase and Na+/NH4+-ATPase indicates a functional interaction of ion transport system with the immune response as evident in its differential and spatial modifications after hypoxia stress in immune-challenged fish. The immune-challenge that produced differential pattern of mRNA expression of Na+/K+-ATPase α-subunit isoforms; nkaα1a, nkaα1b and nkaα1c and the shift in nkaα1a and nkaα1b isoforms expression after hypoxia stress in immune-challenged fish, presents transcriptomic evidence for a modified Na+/K+ ion transporter system in these fish. Collectively, our data thus provide evidence for an interactive immune-stress response in an air-breathing fish, where the patterns of cortisol-thyroid hormone interaction, the ion transporter functions and the non-specific immune responses are reversed by hypoxia stress in immune-challenged fish.

Neuroprotective effect of a triterpenoid saponin isolated from Momordica cymbalaria Fenzl in diabetic peripheral neuropathy.

OBJECTIVES: To investigate the neuroprotective potential of a saponin isolated from the roots of Momordica cymbalaria against peripheral neuropathy in streptozotocin-induced diabetic rats. MATERIALS AND METHODS: A steroidal saponin (SMC) was isolated from M. cymbalaria Fenzl and purified by preparative high-performance liquid chromatography. Diabetes was induced in male Wister rats by injecting streptozotocin 45 mg/kg. Diabetic rats were divided into six groups for neuroprotective effect--three each for preventive and curative groups. Neuropathic analgesia was assessed by tail-flick and hot-plate methods. Dorsal root ganglion (DRG) neurons and sciatic nerves were isolated, and histopathological analysis was performed. Antioxidant activity (superoxide dismutase, catalase, and inhibition of lipid peroxidation) of the saponin was also carried out on the isolated DRG neurons and sciatic nerves to assess total oxidative stress. RESULTS: In both preventive and curative protocols, rats administered with SMC showed significant decrease in tail immersion latency time and increase in pain sensitivity when compared to diabetic control group. There was improvement in the myelination and degenerative changes of the nerve fiber in both the groups, and an obvious delay in the progression of neuropathy was evident. SMC treatment showed significant decrease in superoxide dismutase, catalase activity, and lipid peroxidation in the nerves. CONCLUSIONS: The steroidal saponin of M. cymbalaria (SMC) possesses potential neuroprotective effect in diabetic peripheral neuropathy with respect to neuropathic analgesia, improvement in neuronal degenerative changes, and significant antioxidant activity.

Newer antibacterials in therapy and clinical trials.

In order to deal with the rising problem of antibiotic resistance, newer antibacterials are being discovered and added to existing pool. Since the year 2000, however, only four new classes of antibacterials have been discovered. These include the oxazolidinones, glycolipopeptides, glycolipodepepsipeptide and pleuromutilins. Newer drugs were added to existing classes of antibiotics, such as streptogramins, quinolones, beta-lactam antibiotics, and macrolide-, tetracycline- and trimethoprim-related drugs. Most of the antibacterials are directed against resistant S. aureus infections, with very few against resistant gram-negative infections. The following article reviews the antibacterials approved by the FDA after the year 2000 as well as some of those in clinical trials. Data was obtained through a literature search via Pubmed and google as well as a detailed search of our library database.

Not just skin deep: a case report of multiple endocrine neoplasia type 1.

Multiple endrocrine neoplasia (MEN) type 1 is characterized by mainly a triad of pancreatic, pituitary and parathyroid involvement. This is a case report of a 41-year-old male in whom recognition of collagenoma and gingival papule led to the identification of MEN type 1. Often the recognition of such dermatological manifestations help in the presymptomatic diagnosis of complex syndromes.

Determinants of rapid progression to immunodeficiency syndrome among people infected with Human Immunodeficiency Virus, Kerala, India.

CONTEXT: Human Immunodeficiency Virus (HIV) infection progresses in almost all infected persons to Acquired Immunodeficiency Syndrome (AIDS). The aim of the study was to find out the determinants of rapid progression of immunodeficiency among people infected with HIV in Thiruvananthapuram district of Kerala, India. SETTINGS AND DESIGN: The study design used was case control. The setting of the study was antiretroviral treatment (ART) centre of Government Medical College and the self-help group of HIV patients located at Thiruvananthapuram, Kerala. MATERIALS AND METHODS: Cases were people having any one or more of the AIDS defining clinical conditions within 3 years from the diagnosis of HIV infection. Controls were people diagnosed as having HIV at least 3 years ago and with no AIDS-defining clinical conditions till the date of the study. Sample size was 149 with a control case ratio of 1.5:1. STATISTICAL ANALYSIS USED: Mean (standard deviation) and proportions were used to describe the data. Chi-square test and t test were done to test the hypotheses. Binary logistic technique was used to find out the predictors of the outcome. RESULTS: A regression (Binary Logistic) model was used to predict the progression. Fungal infection of nail [adjusted Odds Ratio (OR), 6.4 (1.4, 28.9)] and oral candidiasis [adjusted OR, 2.6 (1.1, 6.4)] were the clinical conditions significantly associated with rapid progression. The significant social factors included non-exposure to professional counseling [adjusted OR, 7.1 (2.0, 24.5)] and the feeling of being stigmatized - felt as preoccupation with thoughts that they are gossiped about and the increase in visitors to "check them out" [adjusted OR, 26.1 (4.9, 138.4)]. The protective nutritional factors in the model were frequent consumption of legumes [adjusted OR, 0.12 (0.04, 0.36)], eggs [adjusted OR, 0.29 (0.09, 0.93)], and plenty of oral fluids [adjusted OR, 0.18 (0.07, 0.47)]. CONCLUSIONS: An approach incorporating the clinical, social, and nutritional factors may retard the progression of HIV infection.

Aqua-{6,6'-dimeth-oxy-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato}(4-hydroxy-benzoato)manganese(III).

The title compound, [Mn(C(18)H(18)N(2)O(4))(C(7)H(5)O(3))(H(2)O)], was synthesized by a template reaction of ethane-1,2-diamine and 3-methoxy-salicylaldehyde in presence of manganese(II) 4-hydroxy-benzoate. The Jahn-Teller-distorted manganese(III) centre has an octa-hedral geometry. Extensive O-H⋯O hydrogen-bonding inter-actions generate a two-dimensional sheet structure parallel to (103).

Hypohydrotic ectodermal dysplasia.

Hypohydrotic ectodermal Dysplasia (Christ-Siemens Touraine syndrome) is a rare genetic disorder that affect several ectodermal structures. The condition is usually inherited as X-linked recessive trait, in which gene is carried by females and manifested in males. The manifestations may vary in individuals and usually involves skin, hair, nail, sweat and sebaceous glands. Hypohydrotic Ectodermal Dysplasia with classical features in two siblings is reported here.

Dietary interventions for multiple sclerosis.

BACKGROUND: Clinical and experimental data suggest that certain dietary regimens, particularly those including polyunsaturated fatty acids (PUFAs) and vitamins might improve outcomes in people with multiple sclerosis (MS). Diets and dietary supplements are much used by people with MS in the belief that they might improve disease outcomes. OBJECTIVES: We performed a Cochrane review of all randomised trials of dietary regimens for MS with the aim of answering MS consumers' questions regarding the efficacy and safety of these interventions. SEARCH STRATEGY: We searched the Cochrane MS Group trial register (February 2006), Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Library, Issue 1, 2006, MEDLINE (PubMed) (1966 to March 2006), EMBASE (1974 to March 2006) and the bibliographies of papers found. SELECTION CRITERIA: All randomised controlled trials comparing a specific dietary intervention, diet plan or dietary supplementation, with no dietary modification or placebo, were eligible. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected articles, assessed trial quality and extracted data. Trial quality was poor, particularly as regards descriptions of randomisation, blinding and adverse event reporting. Some studies had large numbers of drop-outs; dropouts were never included in the analyses. MAIN RESULTS: PUFAs did not have a significant effect on disease progression, measured as worsening of Disability Status Scale. Omega-6 fatty acids (11-23 g/day linoleic acid) had no benefit in 75 relapsing remitting (RR) MS patients (progression at two years: relative risk (RR)=0.78, 95% CI [0.45 to 1.36]) or in 69 chronic progressive (CP) MS patients (RR=1.67, 95% CI [0.75 to 3.72]. Linoleic acid (2.9-3.4 g/day) had no benefit in CPMS (progression at two years: RR=0.78, 95% CI [0.43 to 1.42]). Slight decreases in relapse rate and relapse severity were associated with omega-6 fatty acids in some small studies, however these findings are limited by the limited validity of the endpoints.Omega-3 fatty acids had no benefit on progression at 12 months in 14 RRMS patients or at 24 months in 292 RRMS patients (RR=0.15, 95% CI [0.01 to 3.11], p= 0.22 at 12 months, and 0.82 95% CI [0.65 to 1.03], p=0.08, at 24 months). The low frequency of reported adverse events suggests no major toxicity associated with PUFA administration. No studies on vitamin supplementation and allergen-free diets were analysed as none met the eligibility criteria. AUTHORS' CONCLUSIONS: PUFAs seem to have no major effect on the main clinical outcome in MS (disease progression), and does not substantially affect the risk of clinical relapses over 2 years. However, the data available are insufficient to assess any potential benefit or harm from PUFA supplementation. Evidence bearing on the possible benefits and risks of vitamin supplementation and antioxidant supplements in MS is lacking. More research is required to assess the effectiveness of diets interventions in MS.

Testosterone replacement therapy in male late onset hypogonadism: available pharmacological strategies.

During the last few years, the general aging of the population and the growing knowledge about male hormonal changes in older age have lead the scientific community to focus on the clinical aspects of secondary hypogonadism in aging males. This syndrome is well defined by the term late-onset hypogonadism (LOH). Although the pathophysiology and the diagnostic aspects have been studied and defined and various preparations are available, the debate on androgen supplementation therapy is still ongoing. As the spectrum of effects of endogenous testosterone is essentially based on its metabolism to dihydrotestosterone and estradiol, testosterone is the treatment of choice for male hypogonadism. The aim of the therapy is to establish a physiological concentration of serum testosterone in order to correct the androgen deficiency, relieve its symptoms and prevent long-term sequelae. All of the available products, despite their varying pharmacodynamic and pharmacokinetic profiles, are able to reach this goal. Here we examine the indications for therapy, the characteristics of the different routes of administration and how to monitor therapy in order to make the treatment safe and effective.

A low molecular weight enterotoxic hemolysin from clinical Enterobacter cloacae.

Seven of 50 Enterobacter cloacae strains from clinical isolates produced small turbid zones of hemolysis in horse and sheep blood agar plates, and the culture supernatants were also positive for hemolytic activity. The hemolysin was partially purified from the culture supernatant of E. cloacae by ultrafiltration (PM-10 membrane) and extraction with acetone. Semipurified hemolysin was stable to heating (100 degrees C, 30 min) and was soluble in organic solvents (acetone, ethanol, and methanol). The toxin showed no loss of biological activity after treatment with trypsin and was stable to acid treatment at pH 2.0 but not at a pH greater than 7.0. In the rat intestinal loop assay, the hemolysin caused hemorrhagic fluid accumulation and severe histological alterations. These findings indicate that this hemolysin may be a putative virulence factor in E. cloacae infections.

Spontaneous chromosome loss and colcemid resistance in lymphocytes from patients with myotonic dystrophy type 1.

Myotonic Dystrophy type 1 (DM1) is one of the many inherited human diseases whose molecular defect is the expansion of a trinucleotide DNA sequence. DM1 shares with fragile X syndrome (FMR1), another "unstable triplet syndrome", several molecular features not present in the remaining triplet diseases. As FMR1 is also characterised by chromosome instability at the site of the expanded triplet, lymphocytes from DM1 patients and healthy donors were cultured for micronucleus (MN) analysis, in order to verify if DM1 is also prone to chromosome instability. A FISH analysis was also carried out to detect the presence of centromeric sequences in the observed MN. The data indicate that DM1 patients present a percentage of centromere-positive MN significantly higher than controls, suggesting that chromosome loss is the main mechanism underlying the origin of the increased spontaneous instability. To further assess the proneness to instability of cells of DM1 patients, cultures from patients and controls were treated in vitro with growing concentrations of two different mutagens: colcemid, a "pure" aneugen compound whose target is tubulin, and mytomicin C, a strong clastogen. The results show that the patient group is significantly less sensitive to colcemid. These data, together with FISH analysis, suggest the presence, in DM1 patients, of an already damaged tubulin, which becomes no more sensitive to the effect of colcemid and which could be the main defect underlying the aneugenic effects in DM1.

Diethylsulphate and methylnitrosourea affect different targets in Chinese hamster fibroblasts: possible mechanisms of aneuploidy induction by these agents.

It has been shown that the ethylating agent diethylsulphate (DES) induces centromere-containing micronuclei with kinetics suggesting that molecules other than DNA could be targets. In quiescent Chinese hamster fibroblasts CHEF/18, O6-alkylated bases inhibit ribosomal protein S6 kinase (S6K1), the terminal member of a kinase cascade responsible for an increased rate of protein synthesis, but not extracellular signal-activated kinases (ERK1/2) or terminal kinases of a second cascade which activates transcription. The inhibition correlates with the appearance of abnormal metaphases at the following mitosis, suggesting that alkylation of the nucleotide pool and inhibition of S6K1 could be one of the mechanisms leading to chromosome loss by alkylating agents. To clarify the role of protein kinases in chromosome loss induced by alkylating agents, we have studied the effects of DES and methylnitrosourea (MNU) on S6K1 and ERK1/2 activation by growth factors. The alkylating agents were studied in a battery of Chinese hamster fibroblasts (CHEF/18, CHO and ClB) with normal and mutated p53 to control for DNA damage-induced activation of p53, which could indirectly inhibit protein kinases. The role of repair in induction of micronuclei was studied in mismatch repair-proficient CHO and repair-deficient ClB cells. Our results indicate that DES induced micronuclei in a mismatch repair-independent manner, within 8 h of treatment, in agreement with a role for S6K1 inhibition in micronucleus formation. MNU induced centromere-containing micronuclei only in CHO cells, one cell cycle after treatment, without any detectable influences on either kinase cascade, suggesting a role for mismatch repair in chromosome loss.

Dual-colour FISH analysis to characterize a marker chromosome in cytochrome P450 2B1 recombinant V79 Chinese hamster cells.

Recombinant V79 Chinese hamster cell lines have been constructed for the expression of useful functions, e.g. cytochromes P450, in order to study metabolism-dependent toxicity. Recombinant cell lines are derived as single clones upon gene transfer and selection from the parental V79 cell line. It is of fundamental importance for a reliable application of the recombinant cell lines to show that the original biological characteristics of the parental line are maintained. As part of these efforts, fluorescence in situ hybridization with Chinese hamster chromosome-specific DNA libraries was performed in order to identify the origin of the chromosomes from which a marker chromosome present in the recombinant cell line V79MZr2B1 was derived, which could not be identified by standard cytogenetic techniques.

Comparison between plasma concentrations of testosterone, nitric oxide and endothelin 1-2 in penile and brachial venous blood: preliminary results in men with psychogenic impotence.

In the present study venous plasma concentrations of testosterone (T), nitric oxide (NO) and endothelin 1-2 (ET1-2) in the flaccid penis and brachial blood were measured in men with psychogenic impotence. T and NO were significantly lower in the penile venous blood, while ET1-2 showed no statistical difference. These data support the hypothesis of testosterone dependence of penile nitric oxide synthesis (NOS).

Intrachromosomal telomeric repeats and stabilization of truncated chromosomes in V79 Chinese hamster cells.

(TTAGGG)n sequences have been localized on the chromosomes of the Chinese hamster V79 cell line. A correlation between telomeric-like repeats and chromosome breakage has been found. Moreover, the analysis of the truncated chromosomes, typical of this cell line, has suggested that intrachromosomal (TTAGGG)n DNA may be important in the stabilization of the new telomeres.

Fragile sites at the centromere of Chinese hamster chromosomes: a possible mechanism of chromosome loss.

On the basis of our previous observations showing that fragile sites (FS) mapped essentially in the centromeric regions of Chinese hamster chromosomes, we consider the possibility that the presence of FS at the centromere might be a source of chromosome loss. In this model a centromeric FS causes a centromeric break giving rise to two chromosome arms which could be lost or maintained with different consequences on the ploidy of daughter cells. To test this hypothesis, Chinese hamster cells have been treated both with N-methyl-N-nitrosourea (MNU), a mutagenic agent which also induces aneuploidy, and vinblastin (VBL), a pure aneugen, used as a control compound, which is supposed not to interact with DNA. The results show that MNU induces the formation of translocated and/or truncated chromosomes, on the contrary VBL is not able to induce chromosome rearrangements. The sites most involved in MNU-induced breaks are the centromeric regions of chromosomes where FS are also present. These breaks cause essentially the loss of one chromosome arm, so that the resulting cells are numerically diploid but presenting partial monosomies. The implications of these results are discussed.