Antibacterial properties of the skin mucus of the freshwater fishes, Rita rita and Channa punctatus.

OBJECTIVES: The skin mucus of Rita rita and Channa punctatus was investigated to explore the possibilities of its antibacterial properties. MATERIALS AND METHODS: Skin mucus was extracted in acidic solvents (0.1% trifluoroacetic acid and 3% acetic acid) and in triple distilled water (aqueous medium). The antibacterial activity of the mucus extracts was analyzed, using disc diffusion method, against five strains of bacteria--the Gram-positive Staphylococcus aureus and Micrococcus luteus; and the Gram negative Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi. RESULTS: In both Rita rita and Channa punctatus, the skin mucus extracted in acidic solvents as well as in aqueous medium show antibacterial activity against Staphylococcus aureus and Micrococcus luteus. Nevertheless, the activity is higher in acidic solvents than that in aqueous medium. The acidic mucus extracts of Rita rita, show antibacterial activity against Salmonella typhi as well. CONCLUSIONS: The results suggest that fish skin mucus have bactericidal properties and thus play important role in the protection of fish against the invasion of pathogens. Fish skin mucus could thus be regarded as a potential source of novel antibacterial components.

Disease Severity Assessment and Short-Term Outcome in Patients with Myasthenia Gravis.

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disorder with a chronic fluctuating course. The outcome measures encapsulate disease severity, functional impact at diagnosis, and objective evaluation of clinical benefit from therapeutic interventions. AIMS AND OBJECTIVE: To assess the disease severity, correlation between various outcome measures, and to evaluate the short-term outcome at 3 months and 6 months in a cohort of MG patients. MATERIALS AND METHODS: Quantitative myasthenia gravis (QMG) score, myasthenia gravis composite (MGC) score, and myasthenia gravis quality of life-15 (MG-QoL-15) score were applied to 54 patients at first visit, 3 months and 6 months follow-up. RESULTS: Mean quality of life-15 (QoL-15) score at base line was 15.241. Mean QMG and MGC scores at baseline were 14.63 ± 8.37 and 15.87 ± 9.14, respectively. QMG score showed a strong positive correlation with both MGC and MG-QoL-15 scores. QMG and MGC scores showed a moderate correlation with acetylcholine receptor antibody (AChR Ab) titers. Mean QMG at follow-up was 9.95 ± 5.49 at 3 months and 6.74 ± 4.74 at 6 months. Mean MGC at follow-up was 10.75 ± 5.58 at 3 months and 6.51 ± 4.36 at 6 months. CONCLUSION: The combination of physician-evaluated and patient-reported outcome measures provided a more discerning picture of patient status and response to treatment. Incorporating MG outcome measures into clinical practice would aid in modulating therapies.

Regulation of protein synthesis in the first trimester human placenta by 17 beta-oestradiol and progesterone.

Addition of 17 beta-oestradiol or progesterone to first trimester human placental explants in vitro resulted in the stimulation of protein synthesis, as seen by autofluorographic analysis of placental tissue and medium proteins. An increase in the incorporation of [35S]methionine into trichloroacetic acid-precipitable proteins was seen, following the addition of 17 beta-oestradiol. Use of aromatase inhibitor to block the synthesis of 17 beta-oestradiol inhibited the protein synthesis and while addition of cyclohexamide blocked both basal- and 17 beta-oestradiol-induced protein synthesis, actinomycin-D blocked only 17 beta-oestradiol induced protein synthesis. Double labelling of placental proteins in the presence and absence of 17 beta-oestradiol also indicated that there is a significant stimulation of protein synthesis by 17 beta-oestradiol. Based on these results it is suggested that oestradiol has a role in regulation of placental protein synthesis.

Significance of lymphocytic sister chromatid exchange frequencies in ovarian cancer patients.

Very few studies report the analysis of sister chromatid exchanges in ovarian cancer patients. We tested the null hypothesis that SCE frequency increases with the advancing stages of ovarian cancer and follows a Poisson distribution. As controls we examined age- and sex-matched healthy volunteers who had no such past history. An increased average SCE frequency was observed in ovarian cancer patients (6.34 +/- 0.09) vis-à-vis controls (4.47 +/- 0.12). Further, the data also suggested a stage-wise increase in the SCE frequency.

A rapid silver staining and destaining technique for the nucleolus organizer region.

Silver staining of nucleolar organizing regions (NOR) is common, but a standard protocol is lacking. A modification of a rapid silver nitrate staining technique for NORs is presented here. Advantages of the modified technique include reliability, speed, cost and the fact that it can be carried out in the light.

Evidence of mitochondrial dysfunction and impaired ROS detoxifying machinery in Fanconi anemia cells.

Fanconi Anemia (FA) is a rare genetic disorder associated with a bone-marrow failure, cancer predisposition and hypersensitivity to DNA crosslinking agents. Majority of the 15 FA genes and encoded proteins characterized so far are integrated into DNA repair pathways, however, other important functions cannot be excluded. FA cells are sensitive to oxidants, and accumulation of oxidized proteins has been characterized for several FA subgroups. Clinical phenotypes of both FA and other closely related diseases suggest altered functions of mitochondria, organelles responsible for cellular energetic metabolism, and also serving as an important producer and the most susceptible target from reactive oxidative species (ROS). In this study, we have shown that elevated level of mitochondrial ROS in FA cells is in parallel with the decrease of mitochondrial membrane potential, the decrease of ATP production, impaired oxygen uptake and pathological changes in the morphology of mitochondria. This is accompanied by inactivation of enzymes that are essential for the energy production (F1F0ATPase and cytochrome C oxidase) and detoxification of ROS (superoxide dismutase, SOD1). In turn, overexpression of SOD1 could rescue oxygen consumption rate in FA-deficient cells. Importantly, the depletion of mitochondria improved survival rate of mitomycin C treated FA cells suggesting that hypersensitivity of FA cells to chemotherapeutic drugs could be in part due to the mitochondria-mediated oxidative stress. On the basis of our results, we propose that deficiency in FA genes lead to disabling mitochondrial ROS-scavenging machinery further affecting mitochondrial functions and suppressing cell respiration.

Glycoproteins in the buccal epithelium of a carp, Cirrhinus mrigala (Pisces, Cyprinidae): a histochemical profile.

Glycoproteins (GPs) were visualized histochemically in the secretory cells - the mucous goblet cells (the type A and the type B), the rodlet cells and the epithelial cells in different regions of the buccal cavity of Cirrhinus mrigala. The type A mucous goblet cells, the type B mucous goblet cells, the rodlet cells and the epithelial cells elaborate GPs with oxidizable vicinal diols and GPs with sialic acid residue without O-acyl substitution. The type A mucous goblet cells, in addition, contain moderate amounts of GPs with O-sulphate esters. The type B mucous goblet cells, in contrast, contain high concentrations of GPs with O-sulphate esters. The rodlet cells secrete small amounts of GPs with oxidizable vicinal diols. The analysis of the results elucidates interesting differences in the composition and concentration of GPs in the mucus elaborated by the secretory cells indicating the potential importance of the glycoproteins in the buccal cavity. These GPs could be considered to represent a mechanism for modulation of the composition of the protective mucus layer correlated to specific functions.

Histochemical analysis of glycoproteins in the secretory cells in the epidermis of the head skin of Indian Major Carp, Labeo rohita.

A series of histochemical procedures were employed to localise and characterise glycoprotein (GP) classes produced by the epithelial cells, the type A and the type B mucous goblet cells (MGCs) and the club cells in the epidermis of Labeo rohita. The epithelial cells secreted GPs with oxidizable vicinal diols and GPs with sialic acid residues without O-acyl substitution in low concentrations. The type A MGCs and the type B MGCs, in contrast, produced these GPs in high concentrations. Further, these MGCs produced GPs with O-sulphate esters as well. GPs with O-sulphate esters were produced in high concentration by the type A MGCs and in low concentration by the type B MGCs. The club cells produced GPs with oxidizable vicinal diols in trace amounts. Production of more than one type of GPs suggested a basis for functional discrimination in their role in the mucous secretions at the skin surface. This is considered an adaptation to environment inhabited by the fish and is discussed in relation to their role in lubrication, protection and inhibition of the invasion and proliferation of pathogenic micro-organisms.

Response of the chromatophores in relation to the healing of skin wounds in an Indian Major Carp, Labeo rohita (Hamilton).

Chromatophores show significant changes during healing of skin wounds in Labeo rohita (Common Name--Rohu). Wound area can be divided into regions I, II and III. After infliction of wound, skin colour becomes significantly dark by 2h that is gradually restored by 2d. In regions II and III at 5 min, epidermal melanophores appear with beaded dendrites. In these regions at 2h and in region I at 6h, epidermal melanophores appear small, rounded or irregular shaped having dendritic processes with aggregated melanosomes. Subsequently, melanophores appear having elongated dendrites with dispersed or aggregated melanosomes. At 24h, clusters of pigmented bodies appear in regions I and II. These bodies increase up to 2d, and then diminish gradually and disappear by 8d. Changes in dermal melanophores in region II at 5 min indicate the onset of degeneration. Degenerating melanophores increase up to 12h, then gradually decline, and disappear by 4d. Simultaneously, stellate melanophore reappear, gradually increase and appear like control by 8d. Dermal melanophores in region III at different intervals appear stellate. In region I stellate dermal melanophores appear at 4d. Stellate melanophores in all regions show different distribution of dispersed or aggregated melanosomes. With the appearance of dermal melanophores, highly refractive, crystalline structures, possibly the refractive platelets of the iridophores, are visualized around them. At subsequent intervals, these are frequently observed. This study provides interesting insights in injury induced changes in chromatophores in fish. The findings could be considered useful in perception of intriguing features in the development of pigment research in future.

Surface ultrastructure of gill arches and gill rakers in relation to feeding of an Indian major carp, Cirrhinus mrigala.

The surface ultrastructure of the gill arches and the gill rakers of an herbivorous fish, Cirrhinus mrigala was investigated by scanning electron microscopy. These structures show significant adaptive modifications associated with the food and feeding ecology of the fish. Closely lying short gill rakers and narrow inter-raker channels on the gill arches are associated to filter and retain food particles. Prominent epithelial protuberances on the gill rakers and the gill arches enable the taste buds, located at their summit, to project well above the surface of the epithelium. This could increase the efficiency of the taste buds in selective sorting of palatable food. Surface specializations of the postlingual organ are recognized adaptive modifications for selecting, trapping or holding food particles. Prominent molariform teeth born on the lower pharyngeal jaw, and the chewing pad opposite it, are associated to work together as an efficient pharyngeal mill. Mucous goblet cells are considered to elaborate mucus secretions to trap, glue and lubricate food particles for their smooth transport for swallowing.

Identification of actin as an estradiol 17-beta-stimulated protein in the human placenta.

Addition of estradiol 17-beta to first trimester human placental minces resulted in an increased synthesis of a protein of apparent molecular weight 45 kDa. The specific involvement of estrogen in the stimulation of this protein was established by demonstrating a reduction in the level of this protein by the addition of CGS 16949 A, an inhibitor of aromatase, a key enzyme in the biosynthesis of estradiol 17-beta and ICI 182,780, an estrogen receptor antagonist. The protein was purified to homogeneity and N-terminal sequencing of two of the internal peptides obtained by enzymatic digestion of the protein, as well as the absence of a free N-terminal indicated that it could be actin. This was confirmed by Western blotting using commercially available actin antiserum. The role of estradiol 17-beta in the stimulation of actin synthesis in human placenta was also established by monitoring the quantitative inhibition of DNase I by actin.