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Biomedical subjects

D Singh

Publications and source records attributed to D Singh.

At least 73 records · Page 4Linked to original sources
PubMed2001

Hypersensitivity reactions and the utility of oral and intravenous desensitization in patients with gynecologic malignancies.

OBJECTIVES: The aims of this study were to characterize hypersensitivity reactions to chemotherapy in patients with gynecologic malignancies and to determine the utility of oral and intravenous desensitization. METHODS: We retrospectively reviewed patients with hypersensitivity reactions identified by direct physician query and by review of charts with ICD9 code E933.1 (Adverse Effect Anti-Neoplastic). RESULTS: Thirty-two patients were identified: 27 with ovarian cancer, 4 with primary peritoneal cancer, and 1 with cervical cancer. Nine patients experienced hypersensitivity reactions during the primary regimen and 23 during chemotherapy for recurrent disease. Hypersensitivity occurred following an average of nine courses. Hypersensitivity occurred secondary to paclitaxel (10) carboplatin (16), cisplatin (4), bleomycin (1), and paclitaxel/carboplatin combination therapy (1). Patients had previously received the agent in 93.8% of carboplatin reactions, in 54.5% of paclitaxel reactions, and in all other agent reactions. Hypersensitivity reactions most commonly included flushing, dyspnea/bronchospasm, back pain, chest discomfort, pruritus, erythema, and nausea and occasionally included alterations in blood pressure or pulse rate. Reactions were successfully treated in 96.9% of patients by interrupting the infusion and administering steroids, antihistamines, benzodiazepines, nebulized beta-agonists, and/or pressors. Seventeen patients underwent desensitization, one to two agents, with 94% success. Nine of ten patients had successful iv desensitization, and 8/10 patients had successful oral desensitization. One failure on the oral regimen had previous successful iv desensitization. CONCLUSIONS: Hypersensitivity reactions to chemotherapeutic agents do not necessarily require exclusion of a compound from the treatment regimen. Intravenous and oral desensitization protocols are useful for successful and safe administration of paclitaxel and platinum compounds in patients with prior hypersensitivity reactions.

Administration, Oral↗
PubMed2001

Mixed anaerobic and aerobic testicular abscess in a neonate.

A premature baby developed a testicular abscess on day 28 of life. The pus aspirated from the abscess grew a mixture of beta hemolytic Streptococcus and a Bacteroides species. The source of this infection could not be identified. The baby improved on antibiotic therapy. This is the first reported case of a polymicrobial testicular infection involving an anaerobe in a neonate. The relevant literature is reviewed.

Bacteroides Infections↗
PubMed2001

Solid-state fermentation: a promising microbial technology for secondary metabolite production.

Solid state (substrate) fermentation (SSF) has been used successfully for the production of enzymes and secondary metabolites. These products are associated with the stationary phase of microbial growth and are produced on an industrial scale for use in agriculture and the treatment of disease. Many of these secondary metabolites are still produced by submerged liquid fermentations (SmF) even though production by this method has been shown to be less efficient than SSF. As large-scale production increases further, so do the costs and energy demands. SSF has been shown to produce a more stable product, requiring less energy, in smaller fermenters, with easier downstream processing measures. In this article we review an important area of biotechnology, since the recent evidence indicates that bacteria and fungi, growing under SSF conditions, are more than capable of supplying the growing global demand for secondary metabolites.

Anti-Bacterial Agents↗
PubMed2001

Long-term results of tibialis posterior tendon transfer for drop-foot.

Twelve patients with drop-foot secondary to sciatic or common peroneal nerve palsy treated with transfer of the tibialis posterior tendon were followed-up for a mean of 90 (24-300) months. In 10 patients the results were 'excellent' or 'good'. In 11 patients grade 4 or 5 power of dorsiflexion was achieved, although the torque, as measured with a Cybex II dynamometer, and generated by the transferred tendon, was only about 30% of the normal side. Seven patients were able to dorsiflex their foot to the neutral position and beyond. The results appeared to be better in men under 30 years of age with common peroneal palsies. A painful flatfoot acquired in adulthood does not appear to be a significant long-term complication despite the loss of a functioning tibialis posterior tendon.

Adolescent↗
PubMed2001

Experience and technique of stapled mechanical cervical esophagogastric anastomosis.

BACKGROUND: Anastomotic leak from cervical esophagogastric anastomoses is a serious problem after esophagectomy. We explored the efficacy of partial or total mechanical anastomoses accomplished with the endoscopic linear cutting and stapling device as an alternative to hand-sewn anastomotic techniques. METHODS: During a 42-month period, 93 patients undergoing either transhiatal esophagectomy or a three-incisional approach to esophagectomy underwent either hand-sewn (n = 43), partial mechanical (n = 16), or totally mechanical (n = 34) cervical esophagogastric anastomoses. The occurrence of postoperative anastomotic leak and the development of postoperative anastomotic stricturing requiring dilation therapy were analyzed between these groups using chi2. RESULTS: All patients survived esophagectomy and were available for postoperative follow-up. Anastomotic leak developed in 10 patients (23%) with hand-sewn, 1 patient (6%) with partial mechanical, and 1 patient (3%) with total mechanical anastomoses (p < 0.05). Anastomotic stricture development paralleled the occurrence of anastomotic leak rate with 25 patients (58%) with hand-sewn, 3 patients (19%) with partial mechanical, and 6 patients (18%) with total mechanical anastomoses experiencing strictures requiring dilation therapy (p < 0.05). CONCLUSIONS: These results suggest that partial or mechanical cervical esophagogastric anastomoses created with the endoscopic stapling device may be superior to hand-sewn anastomotic techniques.

Adenocarcinoma↗
PubMed2001

Lower standing systolic blood pressure as a predictor of falls in the elderly: a community-based prospective study.

OBJECTIVES: We investigated prospectively the relationships among falls, physical balance, and standing and supine blood pressure (BP) in elderly persons. BACKGROUND: Falls occur often and adversely affect the activities of daily living in the elderly; however, their relationship to BP has not been clarified thoroughly. METHODS: A total of 266 community-dwelling elderly persons age 65 years or over (123 men and 143 women, mean age of 76 years) were selected from among residents of Coop City, Bronx, New York. Balance was evaluated at baseline using computerized dynamic posturography (DPG). During a one-year follow-up, we collected information on subsequent falls on a monthly basis by postcard and telephone follow-up. RESULTS: One or more falls occurred in 60 subjects (22%) during the one-year follow-up. Women fell more frequently than men (28% vs. 16%, p < 0.03), and fallers were younger than nonfallers. Fallers (n = 60) had lower systolic BP (SBP) levels when compared with nonfallers (n = 206) (128 +/- 17 vs. 137 +/- 22 mm Hg for standing, p < 0.006; 137 +/- 16 vs. 144 +/- 22 mm Hg for lying, p < 0.02), whereas diastolic BP was not related to falls. Falls occurred 2.8 times more often in the lower BP subgroup (<140 mm Hg for standing SBP) than in the higher BP subgroup (> or =140 mm Hg, p < 0.0003), and gender-related differences were observed (p = 0.006): 3.4 times for women (p < 0.0001) versus 1.9 times for men (p = 0.30). Loss of balance, as detected by DPG, did not predict future falls and was also not associated with baseline BP levels. Multiple logistic regression analysis demonstrated that female gender (relative risk [RR] = 2.1, p = 0.02), history of falls (RR = 2.5, p = 0.008) and lower standing SBP level (RR = 0.78 for 10 mm Hg increase, p = 0.005) were independent predictors of falls during one year of follow-up. CONCLUSIONS: Lower standing SBP, even within normotensive ranges, was an independent predictor of falls in the community-dwelling elderly. Elderly women with a history of falls and with lower SBP levels should have more attention paid to the prevention of falls and related accidents.

Accidental Falls↗
PubMed2001

Decolourisation of synthetic and spentwash melanoidins using the white-rot fungus Phanerochaete chrysosporium JAG-40.

Phanerochaete chrysosporium JAG-40 was isolated from the soil samples saturated with spilled molasses collected from a sugar mill. This isolate decolourised synthetic and natural melanoidins present in spentwash in liquid fermentation; up to 80% in 6 days at 30 degrees C under aerobic conditions. A large inoculum size stimulated fungal biomass production, but this gave less decolourisation of pigment; 5% w/v (dry weight) mycelial suspension was found optimum for maximum decolourisation in melanoidin medium supplemented with glucose and peptone. Gel-filtration chromatography showed that larger molecular weight fractions of melanoidin were decolourised more rapidly than small molecular weight fractions.

Alcoholic Beverages↗
PubMed2001

Decolourisation of molasses wastewater by cells of Pseudomonas fluorescens immobilised on porous cellulose carrier.

Pseudomonas fluorescens isolated from soil samples contaminated with molasses, decolourised molasses wastewater (MWW) samples up to 76% under non-sterile conditions in four days at 30 degrees C. Immobilised cells could be reused for decolourisation activity. However, in subsequent cycles, this was found to decrease from 76% to 50% and from 50% to 24%. Decolourisation activity was regenerated from 30% to 45% by recultivating the immobilised cells in a fresh growth medium. Cellulose carrier coated with collagen was found to be most effective carrier, which produced the highest decolourisation activity of 94% in a 4-day process. This carrier could be reused with 50% of the decolourisation activity retained until the seventh day.

Cells, Immobilized↗
PubMed2001

Biotransformation of cholesterol using Lactobacillus bulgaricus in a glucose-controlled bioreactor.

A novel single-step microbial transformation process for the production of testosterone from cholestrol by Lactobacillus bulgaricus in an aerated fermenter was investigated. The metabolism of glucose possibly supplying reducing power as NADH was necessary for the reduction of androst-4-en-3,17-dione (AD) to testosterone (TS). The growth period for the accumulation of testosterone in maximal amount and the residual glucose increased in parallel with the amount of glucose supplement in growth cultures. After the glucose in the fermentation culture was completely exhausted, most of the testosterone was oxidized to AD. Addition of a larger amount of glucose could prevent oxidation of testosterone to AD. The biotransformation of cholestrol was significantly increased in the presence of cyclodextrin (CD) in the fermenting medium. The addition of 0.1% CD to the growth medium facilitated the transport of the steroid substrate through the microbial cell wall.

Androstenedione↗
PubMed2001

Typing of drug resistant isolates of Mycobacterium tuberculosis from India using the IS6110 element reveals substantive polymorphism.

We investigated IS6110 polymorphism in clinical isolates of Mycobacterium tuberculosis from patients attending the outpatient department at various hospitals in northern India. DNA fingerprinting of 126 clinical isolates of M. tuberculosis was carried out using restriction fragment length polymorphism (RFLP) associated with the IS6110 element in M. tuberculosis genomes. A substantive degree of polymorphism was evident in the MDR M. tuberculosis isolates. The number of bands in the fingerprints varied from 0 to 19. However, the lack of common bands made it difficult to cluster the majority of these isolates. We were also unable to associate drug resistance with IS6110 copy number. Specific regions of the gyrA and katG genes from a representative number of these isolates were sequenced to determine the genotype. The majority of the isolates analyzed were found to belong to Group 1, indicating that these strains were evolutionarily older. We find no evidence of the W strain, prevalent in the US, in our study. The epidemiological patterns of the various strains in India seem to be very complex, as reflected by the presence of a large number of different strains (types) within north India.

Antitubercular Agents↗
PubMed2001

Anthelmintic resistance on an organized sheep farm in India.

Monitoring anthelmintic resistance in strongyle nematodes by the faecal egg count reduction test and a commercial larval development assay on an organized sheep farm in the semi-arid area of Rajasthan revealed the emergence of resistance to benzimidazoles and rafoxanide and a potential risk of the development of levamisole/tetramisole resistance. A benzimidazole/levamisole combination, avermectins and closantel were each found to be efficacious.

Animals↗
PubMed2001

Characterization and analysis of biphalin: an opioid peptide with a palindromic sequence.

Among the many opioid peptides developed to date as nonaddictive analgesics, biphalin has exhibited extraordinary high potency and many other desirable characteristics. Biphalin is an octapeptide consisting of two monomers of a modified enkephalin, attached via a hydrazine bridge, and with the amino acids assembled in a palindromic sequence. Its structure is (Tyr-D-Ala-Gly-Phe-NH-)-2. However, this unique peptide, like any other synthetic peptide, needs strict quality control because of certain drawbacks associated with peptide synthesis. This paper discusses our approaches to characterizing and analyzing biphalin. Many techniques were used, including elemental analysis, amino acid analysis, amino acid sequence analysis (AASA), mass spectrometry (MS), 1H-NMR, 1H-correlated spectroscopy (COSY)-NMR, high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE). Electrospray ionization (ESI) mass spectrometry, which included both ESI-MS and ESI-MS/MS, was performed to confirm the full sequence because AASA results alone verified only the monomer sequence, and not the full sequence. Although the 1H-NMR results led to a preliminary assignment of many protons, the 1H COSY-NMR results allowed for unequivocal assignment of almost all protons. Peptide purity was determined using two techniques, reversed-phase HPLC and CE. The counter-ion of the peptide, trifluoroacetic acid, was determined by CE, using an indirect detection method developed previously in our laboratory. This paper illustrates successful application of nonconventional techniques to characterize and analyze a structurally modified peptide, biphalin, when standard techniques for peptide analysis are inadequate.

Chromatography, High Pressure Liquid↗
PubMed2001

Posterolateral tunnels and ponticuli in human atlas vertebrae.

The posterolateral tunnel on the superior surface of the first cervical (atlas) vertebra is of normal occurrence in monkeys and other lower animals, but its presence in the form of a tunnel-like canal, for the passage of the third part of the vertebral artery over the posterior arch of the human atlas vertebra is not reported. The aim of the present study was to detect the presence of such a canal, in addition to other types of ponticuli (little bridges) reported by earlier investigators, in macerated atlas vertebrae and routine cadaveric dissections. The posterolateral tunnel was detected in 1.14%, and the posterior and lateral ponticuli in 6.57 and 2% of vertebrae. Probably the bony roof of the posterolateral tunnel serves the purpose of additional lateral extension for the attachment of the posterior atlanto-occipital membrane in quadrupeds, where the load of the head is supported by the extensor muscles of the neck, ligaments and posterior atlanto-occipital membrane. In man, where the weight of the head is borne by the vertical loading of the superior articular process of the atlas, the roof of the tunnel has disappeared.

Adult↗
PubMed2001

Cutaneous photoprotection from ultraviolet injury by green tea polyphenols.

BACKGROUND: In animal models, extracts from green tea have been shown to be remarkably effective at reducing the severity of adverse human health effects of overexposure to ultraviolet (UV) radiation. Although sunscreens and other photoprotective measures have traditionally been used for this purpose, there is a need for additional measures and natural products are increasingly being explored for that purpose. OBJECTIVE: Our purpose was to evaluate the effect of polyphenols from green tea on parameters associated with acute UV injury. METHODS: Areas of skin of normal volunteers were treated with an extract of green tea or one of its constituents. Thirty minutes later, the treated sites were exposed to a 2 minimal erythema dose solar simulated radiation. UV-treated skin was examined clinically for UV-induced erythema, histologically for the presence of sunburn cells or Langerhans cell distributions, or biochemically for UV-induced DNA damage. RESULTS: Application of green tea extracts resulted in a dose-dependent inhibition of the erythema response evoked by UV radiation. The (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) polyphenolic fractions were most efficient at inhibiting erythema, whereas (-)-epigallocatechin (EGC) and (-)-epicatechin (EC) had little effect. On histologic examination, skin treated with green tea extracts reduced the number of sunburn cells and protected epidermal Langerhans cells from UV damage. Green tea extracts also reduced the DNA damage that formed after UV radiation. CONCLUSION: Polyphenolic extracts of green tea are effective chemopreventive agents for many of the adverse effects of sunlight on human health and may thus serve as natural alternatives for photoprotection.

Administration, Topical↗
PubMed2001

A method for evaluating the results of tendon transfers for foot drop.

A system for assessing the results of tibialis posterior tendon transfers in the treatment of foot drop secondary to nerve palsy is proposed. There are seven sections to this scoring system: pain, need for orthosis, ability to wear normal shoes, activity level, muscle power of ankle dorsiflexion, degree of active ankle dorsiflexion, and foot posture. The total score is 100. The results are classified as excellent for scores between 85 and 100, good between 70 and 84, fair between 55 and 69, and poor for scores below 55. The results of 18 patients (mean followup, 64.6 months) who had a tibialis posterior tendon transfer were assessed using this method. Four patients (22.2%) had an excellent result, seven (38.8%) had a good result, two (11.1%) had a fair result, and five (27.7%) had a poor result. The average score was 67.2, suggesting an overall fair result for this operation. In nine patients, there was correlation between the outcome when assessed with this method and with patient rating. In two patients, the outcomes were better when assessed with this method than with patient rating, whereas the reverse was true in seven other patients. Thus, this system may provide a more objective and critical evaluation of tibialis posterior transfers for foot drop.

Adolescent↗
PubMed2001

The watermelon rectum.

This is the first reported case of rectal vascular ectasia in association with gastric antral vascular ectasia (watermelon stomach). The patient, a 39-year-old woman with systemic sclerosis, reported chronic gastrointestinal blood loss and iron deficiency anemia. She had aperistalsis of the distal esophagus, decreased lower esophageal sphincter pressure leading to severe gastroesophageal reflux, and dysmotility of the small intestine. Diagnosis was made by endoscopic appearance of visible linear watermelon-like vascular stripes in the gastric antrum and rectum. Histology confirmed the vascular nature of this disorder, showing dilated and thrombosed capillaries in the lamina propria. Gastric biopsy showed associated fibromuscular hyperplasia in the lamina propria. However, the colonic biopsy showed only focal hyalinization in the lamina propria. The patient was successfully treated using endoscopic bipolar electrocautery. Watermelon stomach has previously been described in association with systemic sclerosis. Based on the histopathologic similarity between rectal vascular ectasia, gastric antral vascular ectasia, and systemic sclerosis, we suggest that the rectal vascular lesion may represent a component of the gastrointestinal manifestations of systemic sclerosis.

Adult↗