Rational modification of a lead molecule: Improving the antifungal activity of indole - triazole - amino acid conjugates.

The modification of a molecule that was identified as highly efficacious in the previous studies could considerably improve the biological activity of the resulting compounds. While targeting lanosterol 14-α demethylase, the molecular modelling studies convinced that the extension of the phenyl ring of compound 1 deep into the hydrophobic pocket of the enzyme may increase the enzyme - ligand interactions and hence improve the anti-fungal profile of the molecules. As a result, the newly designed compounds 2 were synthesized and screened for their anti-microbial properties and these compounds were found to exhibit considerably better activity than the previous molecule 1. Some of the compounds in this series exhibited MIC90 16 µg mL-1 and 32 µg mL-1 against Candida albicans and Aspergillus niger, respectively as against 312 µg mL-1 for compound 1.

In Vitro Evaluation and Statistical Optimization of Antimicrobial Activity of Prunus cerasoides Stem Bark.

Nature is a generous source of compounds with the potential for prevention of infections. Antimicrobial screening of aqueous extract from bark of wild Himalayan cherry (Prunus cerasoides) was carried out against various pathogenic microorganisms with inhibition zone ranging from 19 to 24 mm. An optimization strategy, which included classical method and statistical method (RSM), was applied to optimize the effect of process variables. Fifteen percent plant material extracted at 40 °C for 60 min and at its natural pH (4.5) exhibited best antimicrobial activity with an average zone of inhibition ranging from 19 to 29 mm. Statistical optimization using RSM further enhanced the activity by 1.09-1.24 folds. Minimum inhibitory concentration of the aqueous extract against different microorganism ranged from 1 to 10 mg/ml. The aqueous extract was found to be reasonably thermostable at boiling temperature for 1 h. Viable cell count (VCC) studies of the extract showed it to be bactericidal in nature. Further, the aqueous extract was found to be neither cytotoxic nor mutagenic, when evaluated by MTT assay and Ames mutagenicity test. The results suggest that the aqueous extract of P. cerasoides could be a potential source to obtain new antimicrobials and effective herbal medicines to combat the problem of ever emerging microbial resistance.

Antibiofilm potential of flavonoids extracted from Moringa oleifera seed coat against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans.

AIMS: The increased microbial drug resistance due to biofilms and the side effects associated with the use of conventional drugs is still a major concern in the medical fraternity. This work evaluates the antibiofilm potential of flavonoids extracted from Moringa oleifera seed coat (SC) in search for green and effective alternatives for overcoming menace of biofilms. METHODS AND RESULTS: The study evaluated the minimum inhibitory concentration (MIC) of flavonoids against respective test organisms, inhibition of initial cell attachment as well as disruption of preformed biofilms and metabolic activity of treated biofilms. Mutagenicity and cytotoxicity as well as characterization of the active component were also carried out. Although Pseudomonas aeruginosa showed the lowest MIC of 0.05 mg ml(-1), the action of flavonoids and gentamicin on initial cell attachment revealed a comparable effect against bacterial biofilms, i.e. Staphylococcus aureus and Pseudomonas aeruginosa with approx. 80% inhibition compared to Candida albicans. Disruption of the preformed biofilms revealed that susceptibility of P. aeruginosa began as early as 4 h of exposure to flavonoids with 88% growth inhibition at the end of 24-h incubation. Encouragingly, t-test analysis on the effect of the extract and the standard antibiotic against each organism indicated no significant variance at P < 0.05. A drastic low metabolic activity exhibited by the treated biofilms as compared to the untreated ones was further supportive of the antibiofilm potential of seed coat flavonoids. CONCLUSION: The bioactive component from M. oleifera seed coat has exhibited antibiofilm potential against the test organisms belonging to Gram positive, Gram negative and yeast. SIGNIFICANCE AND IMPACT OF THE STUDY: Antibiofilm potential and biosafety of plant-based flavonoids from M. oleifera seed coat reveal a prospective active principle that could be of use in biofilm-associated menace.

Reversal of inhibition of putative dopaminergic neurons of the ventral tegmental area: interaction of GABA(B) and D2 receptors.

Neurons of the ventral tegmental area (VTA) are critical in the rewarding and reinforcing properties of drugs of abuse. Desensitization of VTA neurons to moderate extracellular concentrations of dopamine (DA) is dependent on protein kinase C (PKC) and intracellular calcium levels. This desensitization is called DA inhibition reversal, as it requires concurrent activation of D2 and D1-like receptors; activation of D2 receptors alone does not result in desensitization. Activation of other G-protein-linked receptors can substitute for D1 activation. Like D2 receptors, GABA(B) receptors in the VTA are coupled to G-protein-linked potassium channels. In the present study, we examined interactions between a GABA(B) agonist, baclofen, and dopamine agonists, dopamine and quinpirole, to determine whether there was some interaction in the processes of desensitization of GABA(B) and D2 responses. Long-duration administration of baclofen alone produced reversal of the baclofen-induced inhibition indicative of desensitization, and this desensitization persisted for at least 60 min after baclofen washout. Desensitization to baclofen was dependent on PKC. Dopamine inhibition was reduced for 30 min after baclofen-induced desensitization and conversely, the magnitude of baclofen inhibition was reduced for 30 min by long-duration application of dopamine, but not quinpirole. These results indicate that D2 and GABA(B) receptors share some PKC-dependent mechanisms of receptor desensitization.

Changes in biochemical constituents of paddy straw during degradation by white rot fungi and its impact on in vitro digestibility.

AIMS: To improve the digestibility of paddy straw to be used as animal feed by means of selective delignification using white rot fungi. METHODS AND RESULTS: Solid state fermentation of paddy straw was carried out with some white rot fungi for 60 days. Different biochemical analyses, e.g. total organic matter (TOM) loss, hemicellulose loss, cellulose loss, lignin loss and in vitro digestibility, were carried out along with laccase, xylanase and carboxymethyl cellulase activity. The results were compared with that of a widely studied fungus Phanerochaete chrysosporium, which degraded 464 g kg(-1) TOM and enhanced the in vitro digestibility from 185 to 254 g kg(-1) after 60 days of incubation. Straw inoculated with Phlebia brevispora possessed maximum crude protein. CONCLUSIONS: All the tested white rot fungi efficiently degraded the lignin and enhanced the in vitro digestibility of paddy straw. Phlebia brevispora, Phlebia radiata and P. chrysosporium enhanced the in vitro digestibility almost to similar levels, while the loss in TOM was much lesser in P. brevispora and P. radiata when compared to P. chrysosporium. SIGNIFICANCE AND IMPACT OF THE STUDY: The study reflects the potential of P. brevispora and P. radiata as suitable choices for practical use in terms of availability of organic matter with higher protein value, selective ligninolysis and better digestibility.

Acute renal failure associated with nonfulminant acute viral hepatitis A.

Hepatitis A runs a benign course in children, but may have atypical presentations in adults. Very rarely acute renal failure complicates nonfulminant hepatitis A. We report a patient with nonfulminant acute viral hepatitis A with multiorgan involvement. Patient had biopsy proven acute interstitial nephritis, acute pancreatitis, acute myocarditis and required hemodialysis for 6 weeks.

Biodecolourisation of some industrial dyes by white-rot fungi.

Eight white-rot fungal strains were screened for biodecolourisation of eight dyes commercially employed in various industries. Decolourisation of Poly R 478 was used as a standard to ascertain the dye-decolourisation potential of various fungi. All the fungi tested significantly decolourised Poly R 478 on solid agar medium. When tested in a nitrogen-limited broth medium, Dichomitus squalens, Irpex flavus, Phlebia spp. and Polyporus sanguineus were better industrial dye decolourisers than Phanerochaete chrysosporium.

Biodecolourization of azo and triphenylmethane dyes by Dichomitus squalens and Phlebia spp.

Nine white-rot fungal strains were screened for biodecolourization of brilliant green, cresol red, crystal violet, congo red and orange II. Dichomitus squalens, Phlebia fascicularia and P. floridensis decolourized all of the dyes on solid agar medium and possessed better decolourization ability than Phanerochaete chrysosporium when tested in nitrogen-limited broth medium.

Comparison of two assay procedures for lignin peroxidase.

The most widely accepted assay for detecting lignin peroxidase, based on the oxidation of veratryl alcohol to veratraldehyde, suffers from some drawbacks. At 310 nm, the wavelength at which the assay is performed, some other materials like lignins, quinonic compounds and aromatics also exhibit strong absorbance thus interfering with the estimation when present in the media. The present study reports the lignin peroxidase production by some white rot fungi under different nutritional conditions. The veratryl alcohol oxidation assay procedure for lignin peroxidase has been compared with another method based on the oxidation of the dye azure B involving absorbance measurements in the visible range. The latter method proved to be much more advantageous over the veratryl alcohol oxidation method, in media supplemented with malt extract, lignin preparations and agricultural residues. The enzyme production by veratryl alcohol assay could be detected only in mineral salts broth. By the azure B assay the enzyme activity was detected in all the media tested. The supplements gave varied response in different media. Veratryl alcohol enhanced the enzyme production in malt extract broth and mineral salts malt extract broth. Among the lignin preparations Indulin AT increased the lignin peroxidase titres from 2 to 20 fold in different fungi. Similarly, wheat straw supplemented in mineral salts broth and malt extract broth, separately, strongly stimulated the lignin peroxidase production. The above studies revealed that azure B assay may act as a substitute or equivalent method.

Effects of various media and supplements on laccase production by some white rot fungi.

White rot fungi produce three main extracellular enzymes involved in ligninolysis; laccase, lignin peroxidase and manganese peroxidase. Though all white rot fungi do not produce all three enzymes, laccase occupies an important place in ligninolysis. The present paper reports its production by some white rot fungi; Daedalea flavida, Phlebia brevispora, Phlebia radiata and Polyporus sanguineus under different nutritional conditions. Of the various basal media tested, mineral salts malt extract broth proved to be the best medium for laccase production. Sugarcane bagasse proved to be the best laccase inducer among the various supplements added to different media.

Cytological features of chondroblastoma: a case report with review of the literature.

Chondroblastoma is an uncommon benign tumor of bone with a characteristic epiphyseal location. This report documents the cytological features on fine-needle aspiration biopsy (FNAB) of a chondroblastoma which appeared as a lytic lesion, predominantly in the metaphysis of the medial condyle of right femur in a 20-year-old male. Smears characteristically revealed hyper- to hypocellular lobules comprising small round to polyhedral cells (chondroblasts) embedded in an abundant myxoid stroma. The cytological diagnosis of chondroblastoma was confirmed on histopathology. The radiological appearance and differential diagnosis in this case is discussed.

Effects of Helicobacter pylori eradication on the natural history of lymphocytic gastritis.

BACKGROUND: Lymphocytic gastritis is characterised by an accumulation of lymphocytes in the surface epithelium of the stomach. Lymphocytic gastritis has been linked to coeliac disease and Helicobacter pylori infection. AIMS: To determine whether H pylori eradication leads to resolution of the lymphocytic infiltrate and clinical improvement in patients with lymphocytic gastritis, and to determine their HLA status. METHODS: The Leeds Dyspepsia Questionnaire (LDQ) was administered to 13 patients with lymphocytic gastritis. H pylori serology, (13)C urea breath test (UBT), and upper gastrointestinal endoscopy with sampling of the duodenum, antrum, and corpus were done in all cases and the HLA status was determined. Eleven patients had at least one positive test for H pylori. Patients with lymphocytic gastritis and H pylori infection were treated with a one week course of omeprazole, clarithromycin, and metronidazole. Gastric and duodenal intraepithelial lymphocyte (IEL) counts were performed, along with histological assessment of gastric and duodenal biopsies before and after H pylori eradication. RESULTS: Two months after treatment there was a significant reduction in gastric IEL counts in both antrum and corpus. There was no significant change in duodenal IEL counts before and after eradication. According to the Sydney grading there was significant improvement in corpus inflammation after eradication. The patients histologically H pylori positive before treatment became H pylori negative. Dyspepsia scores also improved significantly after treatment. CONCLUSIONS: H pylori eradication treatment in patients with lymphocytic gastritis causes significant improvement in the gastric IEL infiltrate, corpus inflammation, and dyspeptic symptoms. H pylori serology is frequently positive when histology and UBT are negative. Lymphocytic gastritis may represent a specific immune response to H pylori infection.

Lymphocytic venulitis: an unusual association with microscopic colitis.

A 79 year old man presented with occult gastrointestinal bleeds and anaemia for two years. He had received 40 units of blood over a period of one year, following which he had a subtotal colectomy as no definite cause of the bleeding was apparent. Macroscopically the colon appeared unremarkable. Light microscopy showed prominent lymphocytic venulitis in the proximal portion, gradually merging into lymphocytic and collagenous colitis distally.

Antimicrobial activity of spices.

Spices have been shown to possess medicinal value, in particular, antimicrobial activity. This study compares the sensitivity of some human pathogenic bacteria and yeasts to various spice extracts and commonly employed chemotherapeutic substances. Of the different spices tested only garlic and clove were found to possess antimicrobial activity. The bactericidal effect of garlic extract was apparent within 1 h of incubation and 93% killing of Staphylococcus epidermidis and Salmonella typhi was achieved within 3 h. Yeasts were totally killed in 1 h by garlic extract but in 5 h with clove. Some bacteria showing resistance to certain antibiotics were sensitive to extracts of both garlic and clove. Greater anti-candidal activity was shown by garlic than by nystatin. Spices might have a great potential to be used as antimicrobial agents.

p53 but not bcl-2 is expressed by most cholangiocarcinomas: a study of 28 cases.

AIMS: To examine the frequency and pattern of expression of p53 and bcl-2 in archival material from patients with cholangiocarcinomas and to evaluate their respective roles in its pathogenesis, diagnosis and prognosis. METHODS AND RESULTS: Twenty-eight surgical cases of cholangiocarcinomas diagnosed at St James's University Hospital and 16 control cases were immunostained with monoclonal antibodies to p53 and bcl-2 using streptavidin-biotin complex method. Pressure cooker was used for antigen retrieval. Of the cholangiocarcinomas, 85.7% (24/28) overexpressed p53. The intensity of staining in these cases varied from 1+ in 2, 2+ in 10 and 3+ in 12 cases. None of the 28 tumours expressed bcl-2. The well differentiated nature of the tumour made assessment of dysplasia difficult, however, where present it did not express p53 or bcl-2. The bile duct epithelium adjacent to the tumour and in the control cases did not show any significant nuclear staining for either antigen. CONCLUSIONS: Overexpression of p53 appears to play an important role as a late event in the pathogenesis of cholangiocarcinomas, while we found no evidence of bcl-2 overexpression. The expression of p53 in 86% of the invasive tumours, as compared to its lack in the adjacent normal bile duct epithelium, makes it potentially useful in the diagnostic histopathology of these cases.

The pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence of duodenal pathology.

AIM: To determine whether the pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence or absence of duodenal pathology. METHODS: 50 cases (M:F, 26:24; median age 57 years) diagnosed as lymphocytic gastritis between 1986 and 1998 with concurrent duodenal (D2) biopsies were identified from a computer search of the pathology records and validated by counting gastric intraepithelial lymphocytes. Gastric and duodenal intraepithelial lymphocyte counts were performed on haematoxylin and eosin (H&E) and anti-CD3 stained sections. D2 biopsies were assessed for villous atrophy and chronic inflammatory cell infiltration by subjective grading, and gastritis was classified and graded according to the updated Sydney system. A case was designated corpus predominant when the corpus chronic inflammation grade exceeded that of the antrum. If it was less, then the case was antrum predominant, and if they were equal it was diffuse (pan-) gastritis. The ratio between the corpus and antral intraepithelial lymphocyte count in individual patients was calculated. RESULTS: Of 50 cases of lymphocytic gastritis, 21 were classified as corpus predominant. With one exception (a case of mild villous atrophy), all were accompanied by normal duodenal morphology. Cases with a corpus predominant gastritis had median duodenal intraepithelial lymphocyte counts of 19 (H&E) and 14.1 (CD3), whereas 29 subjects with an antrum predominant or diffuse gastritis had median counts of 39.9 (H&E) and 37.9 (CD3). Fifteen of these 29 cases (52%) showed villous atrophy; all were graded as moderate or severe. Patients with any degree of villous atrophy had a mean corpus/antrum intraepithelial lymphocyte ratio (H&E) of 0.59 (representing antral predominance), while those with normal duodenal morphology had a ratio of 2.39 (p < 0.0001). CONCLUSIONS: The pattern of involvement of gastric mucosa in lymphocytic gastritis is closely related to the associated duodenal pathology. Those with the corpus predominant form are unlikely to have duodenal pathology, while those with an antral predominant or diffuse form should have distal duodenal biopsies taken to exclude villous atrophy.

Menopausal changes in the myometrium: an investigation using a GnRH agonist model.

Thirty-four premenopausal women were randomized to receive 3.75 mg of leuprorelin acetate depot or placebo for 8 weeks before hysterectomy. Postoperatively, the myometrium was examined by two independent pathologists and the pathologic features were graded. Computer analysis was used to assess myometrial cellularity and arterial wall structure (on hematoxylin and eosin-stained sections) and vascularity (on sections immunostained for Factor VIII-related antigen). The cellularity of the gonadotrophin-releasing hormone agonist-treated myometrium was higher than the controls with less stromal edema. Focal myometrial hyalinization was present in a minority of cases, all in the gonadotrophin-releasing hormone agonist-treated cases. The arteries in the gonadotrophin-releasing hormone agonist-treated uteri underwent atrophy of the tunica media and had significantly more perivascular fibrosis. The number of vessels per 100 myocytes also was decreased. Hypoestrinism secondary to leuprorelin treatment leads to myocyte atrophy, decreased stromal edema, atrophy of the arcuate arteries, and decreased myometrial vascularity.

Immunohistochemical expression of inhibin/activin subunits in epithelial and granulosa cell tumours of the ovary.

Dimeric inhibin-A has been shown recently by a sensitive two-site ELISA assay to be a useful tumour marker in granulosa cell tumours of the ovary. It is also elevated in some patients with malignant epithelial ovarian tumours. To identify the precise subunits of inhibin expressed in ovarian tumours, three monoclonal antibodies, R1, E4, and INPRO (against the alpha C-, beta A-, and pro-alpha-subunits, respectively), were evaluated by immunohistochemistry on a panel of six granulosa cell and nine epithelial tumours. All granulosa cell tumours stained positively with E4 and R1, suggesting expression of dimeric inhibin-A; in two patients where serum levels were measured pre-operatively, they were elevated. The tumours also reacted weakly with INPRO, suggesting the presence of precursor forms of the alpha-subunit. Eight malignant epithelial ovarian tumours expressed the beta A-subunit only, as recognized by E4, while one tumour expressed both alpha- and beta A-subunits, which correlated with an elevated serum inhibin-A level. Thus, while granulosa cell tumours express inhibin, the majority of epithelial tumours probably express activin, a result which needs to be confirmed by serum measurements.

Complete sequences of the neuraminidase genes of swine influenza viruses (H1N1) associated with the respiratory disease in pigs.

The complete nucleotide sequences of neuraminidase (NA) of two swine influenza viruses (H1N1) are presented. A/Sw/Quebec/5393/91 (SwQc91) virus, associated with the chronic respiratory disease and A/Sw/ Quebec/192/81 (SwQc81) virus, associated with the acute respiratory disease, were used. The deduced amino acid sequences of NA of SwQc91 and SwQc81 viruses showed a high degree (>95%) of similarity. The NA gene of both viruses was a single open reading frame of 1459 nucleotides coding for 469 aa with a 5' noncoding region of 21 nucleotides and a 3' noncoding region of 28 nucleotides. The comparison of two sequences showed that there were 23 differences recorded for SwQc91 strain, of which 5, 6, and 12 differences were recorded in the hydrophobic, stalk and head regions, respectively. A potential antigenic determinant changed from Ala to Thr at position 453 and there was a new potential glycosylation site present at position 88 for SwQc91 strain whereas it was absent at position 50 when compared with SwQc81 strain. Estimates of genetic distance and phylogenic tree analysis showed that SwQc91 and SwQc81 viruses were closely related with each other and with the American strain, A/Sw/Wisconsin/4754/94. However, the swine viruses represented a distinct group that was considerably divergent from the group of human viruses.

Merkel cell carcinoma of the skin.

Primary neuroendocrine carcinoma of the skin or Merkel cell carcinoma is an aggressive primary neoplasm. It is commonly seen in the elderly, on the head, neck and extremities, where it can mimic a benign or less malignant skin tumour. Pathological examination shows a generally dense growth of small dark cells, with immunohistochemical evidence of neuroendocrine differentiation. The microscopic appearance is very similar to metastatic oat cell carcinoma from the lung and this must be excluded by clinical means and appropriate imaging studies. In this study we present 13 new cases of Merkel cell carcinoma (the largest published series in the UK) and summarize 214 cases from the literature in which the survival data are given. In our series, 5 of 13 patients died from spread of the Merkel cell carcinoma. From this and other studies, it appears that early diagnosis and wide local excision may be the only way to prolong survival. No other adjuvant therapy has proved effective.