Corneal ulcer due toNeocosmospora vasinfectain an immunocompetent patient

We report a case of Neocosmospora vasinfecta keratitis in a 55-year-old man. While the patient did not recall any specific trauma or eye injury, he might have sustained a trivial wound during the course of his duties as a farmer. Direct examination of corneal scrapings revealed fungus filaments. As topical treatment with natamycin and econazole and subsequent systemic ketoconazole therapy failed, a full thickness therapeutic keratoplasty was performed. Post-operative treatment with amphotericin B and clotrimazole combined with cyclosporine resulted in a complete cure. The residual corneal infiltration in the recipient cornea became clear in a week. The fungal isolate was initially identified as a Fusarium species, but later reidentified through the use of morphological characteristics and sequence analysis of the internal transcribed spacer region as N. vasinfecta. The latters is a Hypocrealean fungus not hitherto reported as a causative agent of keratomycosis.

Ocimum sanctumLinn. (Holy Basil) Ethanolic Leaf Extract Protects Against 7,12-Dimethylbenz[a]Anthracene-Induced Genotoxicity, Oxidative Stress, and Imbalance in Xenobiotic-Metabolizing Enzymes

The present study was designed to evaluate the protective effects of ethanolic Ocimum sanctum leaf extract against 7,12-dimethylbenz[a]anthracene (DMBA)-induced genotoxicity, oxidative stress, and imbalance in xenobiotic-metabolizing enzymes. Four different concentrations of ethanolic O. sanctum leaf extract (100, 200, 300, and 400 mg/kg of body weight) were administered to Wistar rats by intragastric intubation for five consecutive days followed by intraperitoneal injection of DMBA (35 mg/kg of body weight) 90 minutes after the final dose of the extract. Administration of DMBA increased bone marrow micronuclei, phase I enzymes, lipid peroxidation, and protein carbonyl formation. This was accompanied by a significant decrease in the activities of phase II detoxification enzymes and antioxidants in the liver, erythrocytes, and bone marrow. Pretreatment with ethanolic O. sanctum leaf extract at a concentration of 300 mg/kg of body weight significantly reduced micronuclei formation and phase I enzymes as well as lipid and protein oxidation with enhanced antioxidant and phase II enzyme activities. The results of the present study suggest that ethanolic O. sanctum leaf extract inhibits DMBA-induced genotoxicity and oxidative stress by modulating xenobiotic-metabolizing enzymes, reducing the extent of lipid and protein oxidation and up-regulating antioxidant defenses.

Isolation and antimicrobial susceptibility pattern of Nocardia among people with culture-proven ocular infections attending a tertiary care eye hospital in Tamilnadu, South India

AIMS

To evaluate the epidemiology, microbiological features, as well as antibiotic susceptibility patterns of Nocardiafrom cases with ocular nocardial infections seen over a period of 8 years in a tertiary eye care hospital.

METHODS

Microbiology records of 164 cases of culture-proven ocular nocardial infection diagnosed between March 1997 and February 2005 were reviewed retrospectively. The outcome data included isolation rate, predisposing factors, demography (age and sex), and category of infection, utility of conventional diagnostic methods, microbiological profile, and antibiogram-resistogram patterns.

RESULTS

A total of 164 (3.1%) Nocardiaspecies were identified among 5378 culture-proven cases. Ninety-six (58.5%) isolates were from corneal scrapings followed by vitreous biopsy (17.0%). Most (58.0%) of the cases were between 51 and 80 age groups. Male preponderance was obvious. All the 164 (100%) nocardial infections were identified by culture. Of 125 ocular specimens subjected to Gram's staining, nocaridal filaments were identified in 70 (56%) specimens. In addition to KOH mounting, modified AFB staining was also found to be helpful. Upon in vitrosusceptibility testing, 98.7 and 90.2% of nocardial isolates showed sensitivity towards amikacin and ciprofloxacin, respectively.

CONCLUSIONS

Ocular nocardiosis is relatively rare among ocular infections. Amikacin and ciprofloxacin are highly effective in treating ocular nocardiasis. Prompt and accurate microbiological diagnosis and early administration of these antibiotics may have a positive effect on the ocular outcome as well as in controlling nocardial prevalence.

Proliferation, angiogenesis and apoptosis-associated proteins are molecular targets for chemoprevention of MNNG-induced gastric carcinogenesis by ethanolic Ocimum sanctum leaf extract

INTRODUCTION

This study was designed to evaluate the chemopreventive effects of ethanolic Ocimum sanctum (OS) leaf extract on cell proliferation, apoptosis and angiogenesis during N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis.

METHODS

The rats were divided into four groups of ten each. Rats in group one were given MNNG (150 mg/kg body weight) by intragastric intubation three times, with a two-week interval between treatments. Rats in group two were administered MNNG as in group one, and in addition, they received intragastric intubation of ethanolic OS extract (300 mg/kg body weight) three times per week, starting on the day following the first exposure to MNNG. The intubation of ethanolic OS extract continued until the end of the experimental period. Rats in group three were given ethanolic OS leaf extract only. Group four served as controls. All the rats were killed after an experimental period of 26 weeks.

RESULTS

Intragastric administration of MNNG-induced well-differentiated squamous cell carcinomas that showed increased cell proliferation, and angiogenesis with evasion of apoptosis, as revealed by the upregulation of proliferating cell nuclear antigen (PCNA), glutathione S-transferase-pi (GST-pi), Bcl-2, cytokeratin (CK) and vascular endothelial growth factor (VEGF) and with downregulation of Bax, cytochrome C and caspase 3 protein expression. Administration of ethanolic OS leaf extract reduced the incidence of MNNG-induced gastric carcinomas. This was accompanied by decreased expression of PCNA, GST-pi, Bcl-2, CK and VEGF, and overexpression of Bax, cytochrome C, and caspase 3.

CONCLUSION

This study provides evidence that, in MNNG-induced gastric carcinogenesis, the key proteins involved in the proliferation, invasion, angiogenesis and apoptosis, are viable molecular targets for chemoprevention using ethanolic OS leaf extract.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: a multicentre study

PURPOSE

Methicillin resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu.

METHODS

A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates.

RESULTS

Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1%) and 39 (37.9%) were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6%) were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100%) of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin.

CONCLUSION

The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

Subtenons infection by dirofilaria repens

Zoonotic filariasis caused by Dirofilaria repens, a parasite of carnivores occurs mainly in countries surrounding Mediterranean region. The infection occurs in and around eye among animal handlers through vector transmission. We are reporting a case of human Dirofilariasis affecting subtenons region in a 63 year-old woman from Coimbatore, South India. The purpose of this article is to review the clinical course and management of ocular Dirofilariasis.

Polymer supported vanadium and molybdenum complexes as potential catalysts for the oxidation and oxidative bromination of organic substrates

The Schiff base (H2fsal-ohyba) derived from 3-formylsalicylic acid and o-hydroxybenzylamine has been covalently bonded to chloromethylated polystyrene cross-linked with 5% divinylbenzene (abbreviated as PS-H(2)fsal-ohyba, I). Treatment of [VO(acac)2] with PS-H2fsal-ohyba in dimethylformamide (DMF) gave the oxovanadium(iv) complex PS-[VO(fsal-ohyba).DMF] (1). Complex 1 can be oxidized into the dioxovanadium(v) species, PS-K[VO2(fsal-ohyba)] (2) on aerial oxidation in the presence of KOH or into the oxoperoxo species, PS-K[VO(O2)(fsal-ohyba)] (3) in the presence of H2O2 and KOH in DMF suspension. Similarly, PS-[MoO(2)(fsal-ohyba).DMF] (4) has been isolated by the reaction of [MoO2(acac)2] with PS-H2fsal-ohyba. All these complexes have been characterised by various techniques. These complexes catalyse the oxidation of styrene, ethylbenzene and phenol efficiently. Styrene gives five reaction products namely styrene oxide, benzaldehyde, 1-phenylethane-1,2-diol, benzoic acid and phenylacetaldehyde, while ethylbenzene gives benzaldehyde, phenyl acetic acid, styrene and 1-phenylethane-1,2-diol. The oxidation products of phenol are catechol and p-hydroquinone. These catalysts are also able to catalyse the oxidative bromination of salicylaldehyde to 5-bromosalicylaldehyde with ca. 80% selectively in the presence of aqueous 30% H2O2/KBr, a reaction similar to that exhibited by vanadate-dependent haloperoxidases. Their corresponding neat complexes have also been prepared and their catalytic activities have been compared.

Speciation of coagulase negative staphylococcus causing bacterial keratitis

Thirty-five coagulase negative Staphylococcus (CoNS) cultured from corneal ulcer were speciated and antibiotic sensitivity tested. S epidermidis was the commonest isolate and it was sensitive to ampicillin and vancomycin.

Acanthamoeba keratitis - a six year epidemiological review from a tertiary care eye hospital in south India

PURPOSE

This study analyses the prevalence, demography, predisposing factors and seasonal variation of Acanthamoeba keratitis.

METHODS

A retrospective review of all cases presenting with keratitis at the cornea clinic, Aravind Eye Hospital, Coimbatore, from August 1997 to July 2003, was done for screening patients with a provisional diagnosis of Acanthamoeba keratitis. Their records were further analyzed for microbiological details. Cases with culture proven Acanthamoeba keratitis were included for epidemiological analysis.

RESULTS

From a total of 4519 patients who attended cornea clinic 32 (33 eyes) patients were confirmed to be positive for Acanthamoeba keratitis. Twenty cases (62.5%) were males. Majority (18; 54.2%) of the Acanthamoeba keratitis eyes reported corneal trauma by solid objects. No peak period was observed in a year, as the number of cases was almost uniform in all months.

CONCLUSION

This study indicates the increasing prevalence of Acanthamoeba keratitis among non-contact lens users in this region during the 6-year period.

Lattice-dictated conformers in bis(pyrazolyl)pyridine-based iron(II) complexes: Mössbauer, NMR, and magnetic studies

Iron(II) complexes [FeL(2)](ClO(4))(2).CH(3)CN, [FeL(2)](BPh(4))(2).2CH(3)CN, and [FeL(2)](PF(6))(2) with an FeN(6) chromophore of the same ligand L (2,6-bis(3,5-dimethylpyrazol-1-ylmethyl)pyridine) and differing counterions have been made and their crystal and molecular structures determined. The first two crystallized in triclinic space group P(-)1, and the third, with PF(6)(-) anion in Ibca space group. The FeL(2) complex ions in all lattices have similarly distorted octahedral geometry. Variable-temperature Mössbauer spectra of [FeL(2)](ClO(4))(2).CH(3)CN and [FeL(2)](PF(6))(2) measured in the temperature range 1.7-300 K reveal temperature-dependent populations of two different spin states with increased amount of low-spin form at high temperatures, a phenomenon unlike the normal spin crossover behavior; this abnormal behavior is interpreted here as due to the presence of two different conformations. It is very interesting to note that the two different compounds have similar spectra, Mössbauer parameters, and temperature dependence. But the variable-temperature Mössbauer spectra of [FeL(2)](BPh(4))(2).2CH(3)CN in the range 20-300 K do not show the presence of such different species but exhibit a clear phase transition at approximately 200 K. This phase transition is further supported by SQUID measurements. The results of variable-temperature (1)H NMR in CD(3)CN and the solution susceptibility measurement of all complexes also support the presence of high-spin and low-spin forms in solution. Hence, the complex ion [FeL(2)](2+) exhibits a thermally driven interconversion between low-spin and a high-spin structural forms-a phenomenon observed in the solid and solution states due to ligand dynamics. This is not due to the well-known spin crossover phenomenon. These results are compared with the case of normal spin crossover seen in [FeL'(2)](ClO(4))(2) (L' = 2,6-(bis(pyrazol-1-ylmethyl)pyridine)).

Proton positions in the Mn(2+) binding site of concanavalin A as determined by single-crystal high-field ENDOR spectroscopy

High-field (95 GHz) pulsed EPR and electron-nuclear double resonance (ENDOR) techniques have been used for the first time to determine coordinates of ligand protons of a high-spin metal center in a protein single crystal. The protein concanavalin A contains a Mn(2+) ion which is coordinated to two water molecules, a histidine residue, and three carboxylates. Single crystals of concanavalin A were grown in H(2)O and in D(2)O to distinguish the exchangeable water protons from the nonexchangeable protons of the imidazole group. Distinct EPR transitions were selected by performing the ENDOR measurements at different magnetic fields within the EPR spectrum. This selection, combined with the large thermal polarization achieved at 4.5 K and a magnetic field of approximately 3.4 T allowed us to assign the ENDOR signals to their respective M(S) manifolds, thus providing the signs of the hyperfine couplings. Rotation patterns were acquired in the ac and ab crystallographic planes. Two distinct crystallographic sites were identified in each plane, and the hyperfine tensors of two of the imidazole protons and the four water protons were determined by simulations of the rotation patterns. All protons have axially symmetric hyperfine tensors and, by applying the point-dipole approximation, the positions of the various protons relative to the Mn(2+) ion were determined. Likewise, the water protons involved in H-bonding to neighboring residues were identified using the published, ultrahigh-resolution X-ray crystallographic coordinates of the protein (Deacon et al. J. Chem. Soc., Faraday Trans. 1997, 93(24), 4305-4312).

Experimental myocardial necrosis in rats: role of arjunolic acid on platelet aggregation, coagulation and antioxidant status

Arjunolic acid, a new triterpene and a potent principle from the bark of Terminalia arjuna, has been shown to provide significant cardiac protection in isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulant assays, electrocardiographic changes, serum marker enzymes, antioxidant status, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic changes such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a decrease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at an effective dosage of 15 mg/kg body wt. (pre and post treatment), when administered intraperitoneally (i.p.), effects a decrease in serum enzyme levels and the electrocardiographic changes get restored towards normalcy. Arjunolic acid treatment is also shown to prevent the decrease in the levels of superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, alpha-tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies. This study shows that the cardioprotection of arjunolic acid pre and post treatment could possibly be due to the protective effect against the damage caused by myocardial necrosis.

Elucidation of structure and location of V(IV) ions in heteropolyacid catalysts H4PVMo11O40 as studied by hyperfine sublevel correlation spectroscopy and pulsed electron nuclear double resonance at W- and X-band frequencies

Electron spin resonance, pulsed electron nuclear double resonance (ENDOR) spectroscopy at W- and X-band frequencies, and hyperfine sublevel correlation (HYSCORE) spectroscopy have been employed to determine the location of the V(IV) ions in H4PVMo11O40 heteropolyacid catalysts. In these materials the heteropolyanions have the well-known structure of the Keggin molecule. Interactions of the unpaired electrons of the paramagnetic vanadyl ions (VO(2+)) with all relevant nuclei 1H, 31P, and 51V) could be resolved. The complete analysis of the hyperfine coupling tensor for the phosphorus nucleus in the fourth coordination sphere of the V(IV) ion allowed for the first time a detailed structural analysis of the paramagnetic ions in heteropolyacids in hydrated and dehydrated catalysts. The 31P and 1H ENDOR results show that V(IV) ions are incorporated as vanadyl pentaaqua complexes [VO(H2O)5](2+) in the void space between the heteropolyanions in the hydrated heteropolyacid. For the dehydrated H4PVMo11O40 materials the distance between the V(IV) ion and the central phosphorus atom of the Keggin molecule could be determined with high accuracy on the basis of orientation-selective 31P ENDOR experiments and HYSCORE spectroscopy. The results give a first direct experimental evidence that the paramagnetic vanadium species are not incorporated at molybdenum sites into the Keggin structure of H4PVMo11O40 and also do not act as bridges between two Keggin units after calcination of the catalyst. The vanadyl species are found to be directly attached to the Keggin molecules. The VO(2+) ions are coordinated to four or three outer oxygen atoms from one PVMo11 heteropolyanion in a trigonal-pyramidal or slightly distorted square-pyramidal coordination geometry, respectively.