Oral ulcer as an unusual feature of visceral leishmaniasis in an AIDS patient

Leishmaniasis, a globally prevalent parasitic disease, occurs in three forms, viz, visceral, cutaneous and mucocutaneous. It is transmitted by female Phlebotomus sandflies. Human immunodeficiency virus (HIV) infection is increasing worldwide and several reports indicate a rising trend of VL / HIV co-infection, modifying the traditional anthroponotic pattern of VL transmission. India is one of the countries having the largest burden of leishmaniasis; nevertheless, there are very few HIV / leishmania co-infection cases reported so far. We report a 35-year-old homemaker infected with the human immunodeficiency virus; she presented with an oral ulcer. The investigations carried out on her revealed that she was afflicted by visceral leishmaniasis and the oral ulceration was a part of the same. This is only the second such case from the Indian subcontinent and more significantly from a non-endemic area.

Bacillus lehensis sp. nov., an alkalitolerant bacterium isolated from soil

A Gram-positive, endospore-forming, alkalitolerant bacterial strain, designated MLB2T, was isolated from soil from Leh, India, and was subjected to a polyphasic taxonomic study. The strain exhibited phenotypic properties that included chemotaxonomic characteristics consistent with its classification in the genusBacillus. Growth was observed at pH 7.0–11.0, but not at pH 6.0. The DNA G+C content was 41.4 mol%. The highest level of 16S rRNA gene sequence similarity was withBacillus oshimensisJCM 12663T(98.8 %). However, DNA–DNA hybridization experiments indicated low levels of genomic relatedness with the type strains ofB. oshimensis(62 %),Bacillus patagoniensis(55 %),Bacillus clausii(51 %) andBacillus gibsonii(34 %), the species with which strain MLB2Tformed a coherent cluster (based on the results of the phylogenetic analysis). On the basis of the phenotypic characteristics and genotypic distinctiveness of strain MLB2T, it should be classified within a novel species ofBacillus, for which the nameBacillus lehensissp. nov. is proposed. The type strain is MLB2T(=MTCC 7633T=JCM 13820T).

Novel disulphide esters of carbothioic acid as potent, non-detergent spermicides with low toxicity to Lactobacillus and HeLa cells in vitro

BACKGROUND

The design, synthesis, characterization and evaluation of a novel series of non-detergent spermicides has led to the discovery of two unique molecules (DSE-36 and DSE-37) that were approximately 25 times more potent spermicides than nonoxynol-9 (N-9).

METHODS

Normal human spermatozoa were used to assess the spermicidal activity (Sander-Cramer Assay), the effect on sperm-membrane integrity [hypo-osmotic swelling test (HOST)], supravital staining and scanning electron microscopy (SEM) and the induction of apoptosis [fluorescein isothiocyanate (FITC) Annexin-V and JC-1 labelling using flow cytometry] by the new class of compounds. HeLa and Lactobacillus cultures were used to assess the cytotoxicity of compounds and their compatibility to normal vaginal flora, respectively.

RESULTS

Compounds DSE-36 and DSE-37 exhibited a strong spermicidal activity [minimum effective concentration (MEC) = 0.002%], which was approximately 25 times more potent than that of N-9 and Sapindus saponins (MEC = 0.05%). As compared with surfactants, DSE-36 and DSE-37 were found to be safer at MEC towards the growth and survival of Lactobacilli and HeLa cells in vitro and to have a milder effect on sperm plasma membrane. At EC(50) both induced apoptosis in sperm cells as characterized by increased labelling with Annexin-V and decreased polarization of sperm mitochondria.

CONCLUSION

Preliminary studies have revealed that in sharp contrast to the non-specific surfactant action of N-9, DSE-36 and DSE-37 have a highly potent, mechanism-based, detrimental action on human sperm. The unique ability of these non-detergent molecules to selectively kill sperm and spare Lactobacilli and HeLa cells at MEC values much lower than that required for N-9 indicates their potential as superior ingredients for formulation into microbicidal contraceptives.

Substrate activity screening: a fragment-based method for the rapid identification of nonpeptidic protease inhibitors

A new fragment-based method for the rapid development of novel and distinct classes of nonpeptidic protease inhibitors, Substrate Activity Screening (SAS), is described. This method consists of three steps: (1) a library of N-acyl aminocoumarins with diverse, low molecular weight N-acyl groups is screened to identify protease substrates using a simple fluorescence-based assay, (2) the identified N-acyl aminocoumarin substrates are optimized by rapid analogue synthesis and evaluation, and (3) the optimized substrates are converted to inhibitors by direct replacement of the aminocoumarin with known mechanism-based pharmacophores. The SAS method was successfully applied to the cysteine protease cathepsin S, which is implicated in autoimmune diseases. Multiple distinct classes of nonpeptidic substrates were identified upon screening an N-acyl aminocoumarin library. Two of the nonpeptidic substrate classes were optimized to substrates with >8000-fold improvements in cleavage efficiency for each class. Select nonpeptidic substrates were then directly converted to low molecular weight, novel aldehyde inhibitors with nanomolar affinity to cathepsin S. This study demonstrates the unique characteristics and merits of this first substrate-based method for the rapid identification and optimization of weak fragments and provides the framework for the development of completely nonpeptidic inhibitors to many different proteases.

Potential of direct agglutination test based on promastigote and amastigote antigens for serodiagnosis of post-kala-azar dermal leishmaniasis

Post-kala-azar dermal leishmaniasis (PKDL) is a dermal complication, a sequel to kala-azar. Diagnosis of PKDL presents a challenge due to the low parasite burden in the lesions. The direct agglutination test (DAT) based on promastigote and amastigote antigens of Leishmania donovani of indigenous isolates was developed to diagnose PKDL, and the results were compared with those of the rk39 strip test. The sensitivities of DAT for antileishmanial antibody detection, based on promastigote and amastigote antigens at a cutoff titer of 1:800 were 98.5% and 100%, respectively, with corresponding specificities of 96.5% and 100%. DAT could correctly detect 100% polymorphic cases and 95.4% macular PKDL cases. In comparison, the rk39 strip test was able to correctly diagnose 95.6% of polymorphic and 86.0% macular PKDL cases. DAT based on axenic amastigote antigen provided 100% sensitivity and specificity, making it particularly useful for macular PKDL cases, which are often missed by the rk39 strip test. Thus, DAT provides a simple, reliable, and inexpensive test for PKDL diagnosis with potential applicability in field conditions.

Immunodiagnosis of groundnut and watermelon bud necrosis viruses using polyclonal antiserum to recombinant nucleocapsid protein of Groundnut bud necrosis virus

In vitro gene expression strategy was used for the production of polyclonal antiserum to the nucleocapsid protein (NP) of Groundnut bud necrosis virus (GBNV). The GBNV NP gene from cowpea isolate was cloned into 6x His-tagged UA cloning vector and expressed in Escherichia coli [M15] cells. The fusion protein was detected in insoluble fraction and was purified by using Ni-NTA agarose resin. The purified 6x His-fusion protein ( approximately 32 kDa) was used for immunisation to produce a high titre polyclonal antiserum. The antiserum to the NP of GBNV at 1:4000 dilution detected successfully natural infection of GBNV and Watermelon bud necrosis virus in a wide range of cucurbitaceous, leguminous and solanaceous hosts from different locations.

Design and development of multivesicular liposomal depot delivery system for controlled systemic delivery of acyclovir sodium

The aim of the present study was to design a depot delivery system of acyclovir sodium using multivesicular liposomes (MVLs) to overcome the limitations of conventional therapies and to investigate its in vivo effectiveness for sustained delivery. MVLs of acyclovir were prepared by the reverse phase evaporation method. The loading efficiency of the MVLs (45%-82%) was found to be 3 to 6 times higher than conventional multilamellar vesicles (MLVs). The in vitro release of acyclovir from MVL formulations was found to be in a sustained manner and only 70% of drug was released in 96 hours, whereas conventional MLVs released 80% of drug in 16 hours. Following intradermal administration to Wistar rats, the MVL formulations showed effective plasma concentration for 48 hours compared with MLVs and free drug solution (12-16 hours). C(max) values of MVL formulations were significantly less (8.6-11.4 microg/mL) than MLV and free drug solution (12.5 microg/mL). The AUC(0-48) of the MVL formulations was 1.5- and 3-fold higher compared with conventional liposomes and free drug solution, respectively. Overall, formulations containing phosphatidyl glycerol as negatively charged lipid showed better results. The MVL delivery system as an intradermal depot offers the advantage of a very high loading and controlled release of acyclovir for an extended period of time. The increase in AUC and decrease in C(max) reflects that the MVL formulations could reduce the toxic complications and limitations of conventional iv and oral therapies.

Discovery of substituted isoxazolecarbaldehydes as potent spermicides, acrosin inhibitors and mild anti-fungal agents

BACKGROUND

The continued endeavour to design novel, non-detergent molecules that can be useful as topical, prophylactic contraceptives has led to the discovery of substituted isoxazolecarbaldehydes as a new class of compounds exhibiting both spermicidal and acrosin inhibitory activities simultaneously.

METHODS

Normal human semen samples were used to detect the spermicidal and acrosin inhibitory activities of the new compounds. Lactobacillus, HeLa and Candida cultures were used to determine the safety of compounds towards normal vaginal flora, their cytotoxicity and anti-fungal activity. Supravital staining and the hypo-osmotic swelling test (HOST) were used to detect the effect on sperm membrane integrity. Nonoxynol-9 (N-9) was used as a reference standard.

RESULTS

The 5- and 3-substituted isoxazolecarbaldehydes showed significant spermicidal [minimum effective concentration (MEC)=0.005-2.5%] and acrosin inhibitory (IC50=3.9-58 x 10(-4) mol/l) activities in several molecules along with weak fungicidal activity against Candida albicans. Lineweaver-Burk and Dixon plot analysis of a representative structure showed non-competitive inhibition of human acrosin enzyme, and the most potent acrosin inhibitors also considerably diminished the induction of the acrosome reaction by Ca2+ ionophore. Some compounds were found to be significantly safer than N-9 towards Lactobacillus acidophilus in vitro at their respective spermicidal MECs. In the cytotoxicity assay, the IC50 of these compounds towards the HeLa cell line was of the same order as N-9 (0.9-0.1 mmol/l); however, in contrast, the compounds exhibited only a moderate effect on sperm membrane integrity.

CONCLUSIONS

This study indicates that 5- and 3-substituted isoxazolecarbaldehydes are 'first generation' multifunctional, spermicidal molecules that hold promise for development as topical contraceptives with useful associated activities that can add considerably to their effectiveness, safety and prophylaxis.

Inhibiting angiogenesis and tumorigenesis by a synthetic molecule that blocks binding of both VEGF and PDGF to their receptors

Angiogenesis depends on vascular endothelial growth factor (VEGF) for initiation and platelet-derived growth factor (PDGF) for maintenance of blood vessels. We have designed a targeted library of compounds from which we identified a novel molecule, GFB-204, that binds PDGF and VEGF, blocks binding of PDGF and VEGF to their receptors (200-500 nM) and subsequently inhibits PDGFR and Flk-1 tyrosine phosphorylation and stimulation of the protein kinases Erk1, Erk2 and Akt and the signal transducer and activator of transcription STAT3. GFB-204 is selective for PDGF and VEGF and does not inhibit EGF, IGF-1 and FGF stimulation of Erk1/2, Akt and STAT3. GFB-204 inhibits endothelial cell migration and capillary network formation in vitro. Finally, treatment of mice with GFB-204 suppresses human tumor growth and angiogenesis. Thus, inhibition of VEGF and PDGF receptor binding with a synthetic molecule results in potent inhibition of angiogenesis and tumorigenesis.

A microcosm study on bioremediation of p-nitrophenol-contaminated soil using Arthrobacter protophormiae RKJ100

p-Nitrophenol (PNP), a toxic nitroaromatic compound, can build up in soils due to extensive usage of nitrophenolic pesticides and hence needs to be removed. Arthrobacter protophormiae RKJ100, a PNP-degrading organism, was used in this work to study factors affecting its growth, and then evaluated for its capacity to degrade PNP in soil microcosms. Molasses (10%) treated with 0.1% potassium hexacyanoferrate was found to be a suitable and cheap carbon source for inoculum preparation. Induction studies showed that PNP depletion was quicker when cells were induced by pre-exposure to PNP. The efficiency of PNP degradation in soil by strain RKJ100 was seen to be dependent on pH, temperature, initial PNP concentration and inoculum size. Microcosm studies performed with varying concentrations (1.4-210 ppm) of PNP-spiked soils showed that strain RKJ100 could effectively degrade PNP over the range 1.4-140 ppm. A cell density of 2x10(8) colony forming units/g soil was found to be suitable for PNP degradation over a temperature range of 20-40 degrees C and at a slightly alkaline pH (7.5). Our results indicate that strain RKJ100 has potential for use in in situ bioremediation of PNP-contaminated sites. This is a model study that could be used for decontamination of sites contaminated also with other compounds.

Desulphurization of dibenzothiophene and diesel oils by bacteria

AIMS

To study the desulphurization of dibenzothiophene (DBT), a recalcitrant thiophenic component of fossil fuels, by two bacteria namely Rhodococcus sp. and Arthrobacter sulfureus isolated from oil-contaminated soil/sludge in order to use them for reducing the sulphur content of diesel oil in compliance with environmental regulations.

METHODS AND RESULTS

The desulphurization pathway of DBT by the two bacteria was determined by gas chromatography (GC) and GC-mass spectrometry. Both organisms were found to produce 2-hydroxy biphenyl (2-HBP), the desulphurized product of DBT. Sulphur contents of culture supernatants of Rhodococcus sp. and A. sulfureus grown with DBT as sole sulphur source were analysed by X-ray fluorescence indicating sulphur levels of 8 and 10 ppm, respectively, as compared with 27 ppm in control. In order to study desulphurization of diesel oils obtained from an oil refinery, resting cell studies were carried out which showed a decrease of about 50% in sulphur content of the oil obtained from the hydrodesulphurization (HDS) unit of the refinery.

CONCLUSIONS

Rhodococcus sp. and A. sulfureus selectively remove sulphur from DBT to form 2-HBP. Application of these bacteria for desulphurization of diesel showed promising potential for decreasing the sulphur content of diesel oil.

SIGNIFICANCE AND IMPACT OF THE STUDY

The process of microbial desulphurization described herein can be used for significantly reducing the sulphur content of oil, particularly, after the process of HDS which would help in meeting the regulatory standards for sulphur level in diesel oil.

Multiple eccrine hidrocystomas: report of two cases treated unsuccessfully with atropine ointment

Eccrine hidrocystomas are rare, benign, cystic lesions with a lining that resembles that of the eccrine sweat gland and may be solitary or multiple. Multiple eccrine hidrocystomas occur predominantly on the face as asymptomatic, skin-colored to bluish lesions associated with a chronic course and seasonal variability. Treatment of multiple lesions on the face is challenging. Efficacy with atropine ointment is variable. Botulinum toxin and pulsed dye laser are reported to be beneficial. Two cases of multiple eccrine hidrocystomas are reported who showed no response to 1% atropine ointment.

Variability in the coat protein gene of Papaya ringspot virus isolates from multiple locations in India

The coat protein (CP) sequences of eleven Papaya ringspot virus (PRSV) isolates originating from different locations in India were determined, analysed and compared with the sequences of other isolates of PRSV. The virus isolates from India exhibited considerable heterogeneity in the CP sequences. The CP-coding region varied in size from 840-858 nucleotides, encoding protein of 280-286 amino acids. Comparative sequence analysis revealed that the PRSV isolates originating from India were divergent up to 11%. Though the PRSV isolates were differentiated in to two clusters, yet the sequence variation could not be correlated with the geographical origin of the isolates. Implication of the sequence variation in the coat protein derived transgenic resistance in papaya is discussed.

Blocking angiogenesis and tumorigenesis with GFA-116, a synthetic molecule that inhibits binding of vascular endothelial growth factor to its receptor

A small synthetic library of cyclohexapeptidomimetic calixarenes was prepared to identify disrupters of vascular endothelial growth factor (VEGF) binding to its receptor that inhibits angiogenesis. From this library, we discovered GFA-116, which potently inhibits (125)I-VEGF binding to Flk-1 in Flk-1-overexpressing NIH 3T3 cells and human prostate tumor cells with an IC(50) of 750 nM. This inhibition is highly selective for VEGF in that (125)I- platelet-derived growth factor binding to its receptor is not affected. GFA-116 inhibits VEGF-stimulated Flk-1 tyrosine phosphorylation and subsequent activation of Erk1/2 mitogen-activated protein kinases. Furthermore, epidermal growth factor, platelet-derived growth factor, and fibroblast growth factor-dependent stimulation of Erk1/2 phosphorylation are not affected at concentrations as high as 10 microM. In vitro, GFA-116 inhibits angiogenesis as measured by inhibition of migration and formation of capillary-like structures by human endothelial cells as well as suppression of microvessel outgrowth in rat aortic rings and rat cornea angiogenesis. In vivo, GFA-116 (50 mpk/day) inhibits tumor growth and angiogenesis as measured by CD31 staining of A-549 human lung tumors in nude mice. Furthermore, GFA-116 is also effective at inhibiting tumor growth and metastasis to the lung of B16-F10 melanoma cells injected into immunocompetent mice. Taken together, these results demonstrate that a synthetic molecule capable of disrupting the binding of VEGF to its receptor selectively inhibits VEGF-dependent signaling and suppresses angiogenesis and tumorigenesis.

Tretinoin peels versus glycolic acid peels in the treatment of Melasma in dark-skinned patients

BACKGROUND

Chemical peels have become a popular method for treating melasma. Although daily topical 0.05 and 0.1% tretinoin have been used for melasma, the therapy takes at least 4 to 6 months to produce clinically significant lightening. In a recent trial, 1% tretinoin peel has shown good clinical and histologic results after biweekly applications in 2.5 weeks only in the treatment of melasma.

OBJECTIVE

Because there is a paucity of studies evaluating the efficacy and safety of 1% tretinoin peel in the treatment of melasma in dark-skinned Asian population, we conducted a pilot study to evaluate the efficacy and side effects of this potentially new peeling agent versus a standard peeling agent, 70% glycolic acid, in the treatment of melasma in Indian women.

METHODS

Ten female patients of melasma, after written consent, were taken up for an open left-right comparison pilot study of 12 weeks. One percent tretinoin peel was applied on one-half of the face, whereas 70% glycolic acid was applied on the other at weekly intervals. The results were evaluated by a clinical investigator by using the modified Melasma Area and Severity Index and with photographs at baseline and 6 and 12 weeks.

RESULTS

A significant decrease in the modified Melasma Area and Severity Index from baseline to 6 weeks and then from 6 to 12 weeks was observed on both facial sides (p<0.001). Nevertheless, there was no statistically significant difference between the right and the left sides. Side effects were minimal and 1% tretinoin peel appeared to be well tolerated by the patients.

CONCLUSIONS

It was concluded from the present trial that serial 1% tretinoin peel is a well tolerated and as effective a therapy for melasma in dark-skinned individuals as a standard and well-tried chemical peel, 70% glycolic acid, although larger trials over longer periods may be necessary to substantiate such findings.

Hypoacusis in vitiligo

BACKGROUND

Vitiligo affects melanocytes in the skin. Since melanocytes are present in other organs as well, it is plausible that they may be similarly affected.

METHODS

A comparative study of audiological functions was carried out in 180 patients of vitiligo and 60 non-vitiligo controls in the age group of 5-40 years.

RESULTS

In vitiligo patients sensorineural hypoacusis of mild degree was found in 18, moderate in 13 and mild conductive hypoacusis in 3. In controls sensorineural hypoacusis of mild degree was found in only 2 cases.

CONCLUSION

The difference between the two groups was statistically significant. Vitiligo patients have a higher prevalence of sensorineural hypoacusis.

First Report of Occurrence of Papaya ring spot virus Infecting Papaya in Bangladesh

Papaya (Carica papaya L.) is an important fruit crop in Bangladesh. During surveys conducted in Dhaka and Mymensingh regions from April to June 2003, >50% of papaya plants were observed to have leaf mottling, mosaic and mild distortion, and water-soaked streaks on petioles and stem, which are typical symptoms of Papaya ring spot virus (PRSV) infection. Electron-microscopic examination of negatively stained leaf-dip preparations from 10 symptomatic samples revealed the association of flexuous virus particles that were decorated with polyclonal antibodies raised to an isolate from India (PRSV-D). The identity of PRSV associated with the papaya disease in Bangladesh was further confirmed by reverse transcription polymerase chain reaction and sequence analysis (2). By using PRSV specific primers (2), the 3'-terminal region comprising a part of the nuclear inclusion b gene, the coat protein (CP) gene, and the untranslated region were amplified and sequenced (GenBank Accession No. AY423557). The CP gene consisted of 286 amino acids and the conserved regions common to the genus Potyvirus, such as WCIEN and QMKAA, were present. Like all known PRSV sequences (1), a stretch of glutamic acid and lysine repeats (EK region) after the aphid transmission motif (DAG) also was present. Comparative CP amino acid sequence analyses revealed that the virus infecting papaya in Bangladesh, designated as PRSV-Bd, shared 89 to 92% identity with PRSV isolates from India and 88 to 93% identity with isolates from other parts of the world. To our knowledge, this is the first report of occurrence of PRSV infecting papaya in Bangladesh. References: (1) M. F. Bateson et al. J. Gen. Virol. 83:2575, 2002. (2) R. K. Jain et al. Ann Appl. Biol. 132:413, 1998.

Multicenter clinical trials on a novel polyherbal formulation in allergic rhinitis

Allergic rhinitis is the most frequently occurring immunological disorder. It affects men, women and children and represents significant cost in terms of suffering and loss of productivity. Allergy is termed as an excessive reaction to an environmental allergen. Pollen, mold, dust, mite and animal allergens that contact the nasal or eye lining cause sneezing, nasal congestion and itchy, watery, swollen, red eyes. Although a broad spectrum of therapeutic options is available, the treatment of allergic rhinitis appears to be far from satisfactory. A novel polyherbal formulation (PF; Aller-7/NR-A2) comprising seven medicinal herbal extracts was assessed in a multicenter clinical trial involving 545 patients (321 males and 224 females) aged 18-59 years for 12 weeks to evaluate its clinical efficacy in patients suffering from allergic rhinitis. A total of 171 patients participated in double-blind, randomized, placebo-controlled studies in three centers, while 374 patients were included in the open-label studies in 11 centers. The three major symptoms (sneezing, rhinorrhea and nasal congestion) of allergic rhinitis were significantly reduced. Significant improvement was also observed in absolute eosinophil count, mucociliary clearance time, peak expiratory flow rate and peak nasal flow rate. No serious adverse events that warranted cessation of treatment were observed. Minor adverse effects were noted in both the treatment and placebo groups. Thus, this study demonstrates that Aller-7/NR-A2 is well tolerated and efficacious in patients with allergic rhinitis.