Synergistic effect of ayurvedic pearl preparation on enhancing effectiveness of antibiotics

Studies were carried out with ayurvedic preparations derived from pearl, which include preparations bhasma and pishti. The synergistic effect to reduce the dose of antibiotic was tested against E. coli the test bacterium with ampicillin antibiotic by bore well and disks diffusion methods. It was observed that pearl preparations do not show any antibacterial activity but when used at 200 microg/ml concentration with antibiotics, then even at sub-lethal dose, the antibiotic has effectively shown the results with reduced contact time. The protocol was also tested with the other bacteria like, Pseudomonas aeruginosa. Vibrio cholarae, Salmonella typhi, and Staphylococcus aureus and has shown similar results. The pearl bhasma synergistic effect was also tested with other antibiotics such as erythromycin, kanamycin, and ampicillin.     

Microbial synthesis of semiconductor CdS nanoparticles,their characterization,and their use in the fabrication of an ideal diode

Cadmium sulfide nanoparticles were synthesized intracellularly by a Schizosaccharomyces pombe strain when challenged with 1 mM cadmium in solution. The nanoparticles, a known semiconducting material, exhibited an absorbance maximum at 305 nm. X-ray scattering data showed that the nanoparticles had a Wurtzite (Cd(16)S(20))-type hexagonal lattice structure and most of the nanoparicles were in the size range of 1-1.5 nm. The nanoparticles were used in the fabrication of a heterojunction with poly (p-phenylenevinylene). The diode exhibited approximately 75 mA/cm(2) current at 10 V when forward biased and the breakdown occurred at approximately 15 V in the reverse biased mode. These characteristics are considered ideal for a diode.     

Fatal <Emphasis Type="Italic">Talaromyces marneffei</Emphasis> Infection in a Patient with Autoimmune Hepatitis

Talaromyces marneffei, previously known as Penicillium marneffei, is the most important pathogenic thermally dimorphic fungus causing systemic mycosis in Southeast Asia. Traditionally, T. marneffei infection in human was mainly associated with acquired immunodeficiency syndrome caused by HIV infection. In recent years, there has been an increasing number of T. marneffei infections reported in non-HIV-infected patients with other immunocompromised conditions, including autoantibodies against interferon-gamma, systemic lupus erythematosis, solid organ transplantation, Job’s syndrome, hematological malignancies, and use of novel targeted therapies. In this article, we describe the first case of fatal T. marneffei infection in a patient with underlying autoimmune hepatitis, presented as fever without localizing features. The diagnosis of talaromycosis was confirmed with the identification of the fungi isolated from the blood culture specimen by conventional methods and using matrix-assisted laser desorption–ionization time-of-flight mass spectrometer. This case shows the importance of a high index of suspicion, particularly for such a highly fatal but potentially treatable fungal infection.     

Peroxidase, an alternate pathway to cytochrome P-450 for xenobiotic metabolism in skin: partial purification and properties of the enzyme from neonatal rat skin

Peroxidase activity was partially purified from neonatal (3 to 6 days old) rat skin. The membrane-bound peroxidase activity was extracted with 0.5 M calcium chloride and was monitored spectrophotometrically at 470 nm with 2-methoxyphenol (guaiacol) and hydrogen peroxide as substrates. Subcellular distribution studies indicated the activity to be highest and comparable in nuclei and mitochondria, lowest in microsomes, and absent in cytosol. The peroxidase activity was partially purified by affinity chromatography on concanavalin A-sepharose 4B and by gel filtration using Bio-Gel P-150. Purification factors from these two steps were about 25 and 4, respectively. Peroxidase extraction in the presence of 2 mM N-ethylmaleimide increased activity about twofold. The combination of 2 mM N-ethylmaleimide and 10% (w/v) glycerol was found to be optimal for preservation of activity. Peroxidase activity increased linearly with increases in protein concentration, time, and guaiacol concentration. Activity was inhibited approximately 75% by 0.1 mM potassium cyanide or 0.05 mM sodium azide. Pyrogallol, hydroquinone, p-cresol, catechol, benzidine, 3,3'-dimethoxybenzidine, tetramethylbenzidine and p-phenylenediamine also acted as substrates for the rat cutaneous peroxidase.     

Intermediary carbon metabolism in Frankia

Frankia isolate NPI 0136010 was able to use only propionate and acetate as sole carbon sources and was unable to use hexoses, pentoses, disaccharides, and trisaccharides. Cell free extracts were surveyed for key enzymes of intermediary carbon metabolism. Enzymes of the Embden-Meyerhof-Parnas (EMP) pathway, the tricarboxylic acid (TCA) cycle and glyoxylate shunt were detected while enzymes of the pentose phosphate (PP) and Entner-Doudoroff (ED) pathways were absent. Malic enzyme was present allowing for the conversion of malate to pyruvate and gluconeogenesis. Radiorespirometric analysis confirmed the operation of the TCA cycle and established the methylmalonyl pathway as the route of propionate metabolism. The uptake of propionate was active and mediated by sulfhydryl groups.     

Antimicrobial properties of cumin

Fungal (Aspergillus and Penicillium spp.) and yeast (Saccharomyces and Candida spp.) cultures were more sensitive to cumin volatile oil and cuminaldehyde than bacteria. Among Gram-negative bacteria, Escherichia coli was the most sensitive to the volatile oil while Pseudomonas aeruginosa was the most resistant. Staphylococcus aureus had an MIC almost double that of all other Gram-positive species tested, while the fungi had MIC values 10 to 20 times lower than those of the bacteria.The authors are with the Food & Fermentation Technology Division, University Department of Chemical Technology, Matunga, Bombay-400019, India     

Drosophila GABAergic systems II. Mutational analysis of chromosomal segment 64AB,a region containing the glutamic acid decarboxylase gene

The Drosophila melanogaster Gad gene maps to region 64A3-5 of chromosome 3L and encodes glutamic acid decarboxylase (GAD), the rate-limiting enzyme for the synthesis of the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Because this neurotransmitter has been implicated in developmental functions, we have begun to study the role of GABA synthesis during Drosophila embryogenesis. We show that Gad mRNA is expressed in a widespread pattern within the embryonic nervous system. Similarly, GAD-immunoreactive protein is present during embryogenesis. These results prompted us to screen for embryonic lethal mutations that affect GAD activity. The chromosomal region to which Gad maps, however, has not been subjected to an extensive mutational analysis, even though it contains several genes encoding important neurobiological, developmental, or cellular functions. Therefore, we have initially generated both chromosomal rearangements and point mutations that map to the Drosophila 64AB interval. Altogether, a total of 33 rearrangements and putative point mutations were identified within region 64A3-5 to 64B12. Genetic complementation analysis suggests that this cytogenetic interval contains a minimum of 19 essential genes. Within our collection of lethal mutations are several chromosomal rearrangements, two of which are in the vicinity of the Gad locus. One of these rearrangements, Df(3L)C175, is a small deletion that removes the Gad locus and at least two essential genes; the second, T(2;3)F10, is a reciprocal translocation involving the second and third chromosomes with a break within region 64A3-5. Both of these rearrangements are associated with embryonic lethality and decreased GAD enzymatic activity.     

Pulmonary histopathology induced by respiratory syncytial virus (RSV) challenge of formalin-inactivated RSV-immunized BALB/c mice is abrogated by depletion of CD4+ T cells.

In previous studies, it was observed that children immunized with a formalin-inactivated respiratory syncytial virus vaccine (FI-RSV) developed severe pulmonary disease with greater frequency during subsequent natural RSV infection than did controls. During earlier efforts to develop an animal model of this phenomenon, enhanced pulmonary histopathology was observed after intranasal RSV challenge of FI-RSV-immunized cotton rats. Progress in understanding the immunologic basis for these observations has been hampered by the lack of reagents useful in manipulating the immune response of the cotton rat. This problem prompted us to reinvestigate the characteristics of immunity to RSV in the mouse. In the present studies, extensive pulmonary histopathology was observed in FI-RSV-immunized or RSV-infected BALB/c mice upon RSV challenge, and studies to determine the relative contributions of CD4+ or CD8+ T cells to this process were undertaken. Mice previously immunized with FI-RSV or infected with RSV were depleted of CD4+, CD8+, or both T-cell subsets immediately prior to RSV challenge, and the magnitude of inflammatory cell infiltration around bronchioles and pulmonary blood vessels and into alveolar spaces was quantified. The magnitude of infiltration at each anatomic site in previously FI-RSV-immunized or RSV-infected, nondepleted animals was similar, indicating that this is not a relevant model for enhanced disease. However, the effect of T-cell subset depletion on pulmonary histopathology following RSV challenge was very different between the two groups. Depletion of CD4+ T cells completely abrogated pulmonary histopathology in FI-RSV-immunized mice, whereas it had a much smaller effect on mice previously infected with RSV. FI-RSV-immunized or RSV-infected animals depleted of CD8+ T cells had only a modest reduction of pulmonary histopathology. In addition, RSV infection induced high levels of major histocompatibility complex class I-restricted cytotoxic T-cell activity, whereas FI-RSV immunization induced a low level. These data indicate that immunization with FI-RSV induces a cellular immune response different from that induced by RSV infection, which likely played a role in enhanced disease observed in infants and children.