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Biomedical subjects

P Garg

Publications and source records attributed to P Garg.

At least 19 recordsLinked to original sources

Chemical and hormonal determinants of vascular calcification in vitro.

Vascular calcification is a complex process that is dependent not only on the physicochemical effects of Ca, PO(4), and pH, but also on smooth muscle factors that may be regulated by these ions as well as by 1,25-dihydroxyvitamin D(3) (calcitriol) and parathyroid hormone (PTH). These minerals and hormones were tested in a model of medial calcification in rat aorta maintained in culture for 9 days. Calcification was quantitated as incorporation of (45)Ca, alkaline phosphatase activity was measured in aortic homogenates, and osteopontin production was measured from immunoblots of culture medium. At 1.8 mM Ca (1.46 mM free), calcification occurred at or above 2.8 mM PO(4). At 3.8 mM PO(4), calcification occurred at or above 1.10 mM free [Ca]. At a constant [Ca] x [PO(4)], calcification varied directly with [Ca] and inversely with [PO(4)]. Calcification was directly related to pH between 7.19 and 7.50 but not altered by PTH or calcitriol. Alkaline phosphatase activity and osteopontin production were increased by Ca, PO(4), calcitriol, and PTH. We conclude that calcification of rat aorta in vitro requires elevation of both [Ca] and [PO(4)], and that [Ca] rather than [PO(4)] or the product of the two is the dominant determinant. The induction of alkaline phosphatase and osteopontin indicates that Ca and PO(4) have effects in addition to simple physicochemical actions. Although PTH and calcitriol did not increase calcification in vivo, they have effects on smooth muscle that could influence calcification in vivo. Calcification is enhanced by alkalinity within the range produced during hemodialysis.

Alkaline Phosphatase↗

Discrete analysis of bile acid in serum and bile with 3 alpha-hydroxysteroid dehydrogenase and diaphorase immobilized onto alkylamine glass beads.

3alpha-Hydroxysteroid dehydrogenase (3alpha-HSD) from Pseudomonas testosteronei and diaphorase (lipoyl dehydrogenase) from Clostridium spp were immobilized individually onto alkylamine glass beads through glutaraldehyde coupling. A cost-effective enzymic colorimetric method for determination of bile acid in the serum and bile was developed employing mixture of the immobilized enzymes. The method was based upon measurement of NADH generated from NAD+ during oxidation of bile acid by immobilized 3alpha-HSD with a color reagent consisting of nitrobluetetrazolium (NBT) chloride salt and immobilized diaphorase in 0.065 M sodium phosphate buffer (pH 7.0). The minimum detection limit of the method was 4.8 pmol/L in the serum and 19.5 micromol/L in bile. The per cent recovery of added bile acid in the serum and bile was 89.1 and 95.0, respectively. Within and between batch coefficients of variation (CV) for bile acid determination were <1.0% and <0.2% in the serum and <0.2% and <0.6% in bile, respectively. A good correlation for bile acid in the serum (r1= 0.95) and in bile (r2 = 0.93) was obtained by a standard chemical method (a commonly used method in India) and the present method. The mixture of immobilized 3alpha-HSD and diaphorase lost 30% of its initial activity after 4 months of regular use. The cost of bile acid determination for 100 the serum and bile samples by the present method was found to be lower than by a commercially available method (Sigma kit 450-A).

3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)↗

Outcome of pterygium surgery: analysis over 14 years.

AIM: To report the outcome of pterygium surgery performed at a tertiary eye care centre in South India. METHODS: Retrospective analysis of medical records of 920 patients (989 eyes) with primary and recurrent pterygia operated between January 1988 and December 2001. The demographic variables, surgical technique (bare sclera, primary closure, amniotic membrane transplantation (AMT), conjunctival autograft (CAG), conjunctival-limbal autograft (CLAG), or surgical adjuvants), recurrences and postoperative complications were analysed. RESULTS: A total of 496 (53.9%) were male and 69 (7.5%) had bilateral pterygia. Bare sclera technique was performed in 267 (27.0%) eyes, primary conjunctival closure in 32 (3.2%), AMG in 123 (12.4%), CAG in 429 (43.4%), and CLAG in 70 (7.1%). Adjuvant mitomycin C was used in 44 (4.4%) cases. The mean duration of follow-up was 8.9+/-17.0 and 5.9+/-8.8 months for unilateral primary and recurrent pterygia, respectively. The overall recurrence rate was 178 (18.0%). Following primary and recurrent unilateral pterygium excision respectively, recurrences were noted in 46 (19.4%) and 1 (33.3%) eyes after bare sclera technique, five (16.7%) and 0 after primary closure, 28 (26.7%) and 0 with AMG, 42 (12.2%) and five (31.3%) with CAG, and nine (17.3%) and two (40%) with CLAG. Recurrences were significantly more in males with primary (23.3 vs 10.7%, P<0.0001) and recurrent (26.7 vs 0%, P=0.034) pterygia, and in those below 40 years (25.2 vs 14.8%, P=0.003). CONCLUSION: CAG appears to be an effective modality for primary and recurrent pterygia. Males and patients below 40 years face greater risk of recurrence. Bare sclera technique has an unacceptably high recurrence. Prospective studies comparing CAG, CLAG, and AMG for primary and recurrent pterygia are needed.

Adolescent↗

The value of corneal transplantation in reducing blindness.

PURPOSE: To analyse the role of keratoplasty in reducing world blindness due to corneal diseases. METHODS: Review of published literature. We collected and analysed articles published in the English language literature related to the prevalence and causes of blindness in different parts of the world, causes of corneal blindness, and outcome of corneal transplantation for various corneal diseases. RESULTS: A total of 80% of the world's blind live in developing countries. Retinal diseases are the most important causes of blindness (40-54%) in established economy nations while cataract (44-60%) and corneal diseases (8-25%) are the most common causes of blindness in countries with less developed economies. Keratitis during childhood, trauma, and keratitis during adulthood resulting in a vascularized corneal scar and adherent leucoma are the most frequent causes of corneal blindness in developing countries. Corneal diseases are responsible for 20% of childhood blindness. Nearly 80% of all corneal blindness is avoidable. The outcome of keratoplasty for vascularized corneal scar and adherent leucoma is unsatisfactory, necessitating repeat surgery in a high proportion of these cases. Other barriers for keratoplasty in these nations are suboptimal eye banking, lack of trained human resources, and infrastructure. CONCLUSIONS: Since the developing world carries most of the load of corneal blindness and the major causes of corneal blindness are corneal scar and active keratitis, development of corneal transplantation services need a comprehensive approach encompassing medical standards in eye banking, training of cornea specialists and eye banking personnel and exposure of ophthalmologists to care of corneal transplants for better follow-up care. However, concerted efforts should be made to develop and implement prevention strategies since most corneal blindness is preventable.

Blindness↗

Divalproex sodium in the management of post-herpetic neuralgia: a randomized double-blind placebo-controlled study.

BACKGROUND: Post-herpetic neuralgia is difficult to treat. Divalproex sodium (valproic acid and sodium valproate in molar ratio 1:1) has been used successfully in the management of various painful neuropathies. AIM: To study the effectiveness and safety of divalproex sodium in the management of post-herpetic neuralgia. DESIGN: Randomized double-blind placebo-controlled trial. METHODS: We enrolled 48 consecutively attending out-patients with post-herpetic neuralgia, out of whom three were excluded (two had insufficient pain, one withdrew consent). Quantification of pain was by Short Form-McGill pain questionnaire (SF-MPQ), visual analogue scale (VAS), present pain intensity score (PPI) and 11 point Likert scale (11 PLS) at the beginning of the study, after 2 weeks, 4 weeks and at the end of the study (8 weeks). We also assessed patients' global impression of change by questionnaire at the end of the study. RESULTS: After 8 weeks treatment with 1000 mg/day divalproex sodium, there was significant reduction in pain: SF-MPQ, 20.47 +/- 2.29 to 11.90 +/- 6.52 (p < 0.0001); PPI 4.0 +/- 0.52 to 1.95 +/- 1.29 (p < 0.0001); VAS 70.17 +/- 9.21 to 31.27 +/- 29.74 (p < 0.0001) and 11 PLS 6.97 +/- 0.73 to 3.63 +/- 2.34 (p < 0.0001) in comparison to placebo (means +/- SEM). The 'global impression of change' questionnaire showed much or moderate improvement in pain in 58.2% of patients receiving divalproex vs. 14.8% of those receiving placebo. The drug was well tolerated by all patients, except one who developed severe vertigo after 10 days of treatment. DISCUSSION: Divalproex sodium provides significant pain relief in patients of post-herpetic neuralgia, with very little incidence of adverse reactions. These data provide a basis for longer trials in a larger group of patients.

Adult↗

Granulomatous inflammation in Acanthamoeba keratitis: an immunohistochemical study of five cases and review of literature.

PURPOSE: Acanthamoeba keratitis usually presents as a necrotizing stromal inflammation. We report a rare presentation of granulomatous inflammation in Acanthamoeba keratitis METHODS: Retrospective clinico-pathologic case series. RESULTS: Five corneal tissues (3 corneal buttons, 2-eviscerated contents) from patients suffering from severe Acanthamoeba keratitis not responding to anti-Acanthamoeba treatment, revealed a florid granulomotous inflammation with multinucleated giant cells in the posterior stroma and around Descemet's membrane. Phagocytosed parasites were noted within the giant cells. Vascularization of the corneal stroma was noted in two cases. Immunophenotyping revealed a predominance of T lymphocytes and macrophages. Clinically, four of five cases had shown features of limbal and scleral involvement. CONCLUSION: Granulomatous inflammation in the posterior corneal stroma, is not an uncommon finding in Acanthamoeba keratitis and could possibly be immune-mediated, contributing to persistence and progression of disease. CLINICAL RELEVANCE: Presence of granulomatous inflammation in Acanthamoeba keratitis, in most cases is associated with limbal and scleral involvement and therefore could be considered as one of the poor prognostic markers. Further studies are required to ascertain the specific clinical features and appropriate management strategies in these cases.

Acanthamoeba↗

Measurement of bile acid in serum and bile with arylamine-glass-bound 3alpha-hydroxysteroid dehydrogenase and diaphorase.

3Alpha-hydroxysteroid dehydrogenase (3-HSD) from Pseudomonas testosteroni and diaphorase (lipoyl dehydrogenase) from Clostridium spp. have been immobilized individually onto arylamine glass beads through diazotization. A cost-effective enzymic colorimetric method for determination of bile acid in serum and bile employing a mixture of these immobilized enzymes was developed. The method is based on measurement of reduced nicotinamide adenine dinucleotide generated from bile acid in serum/bile by immobilized 3alpha-HSD with a color reagent consisting of nitro blue tetrazolium chloride salt, oxidized nicotinamide adenine dinucleotide, and immobilized lipoyl dehydrogenase in 0.065 M sodium phosphate buffer, pH 7.0. Analytical recovery of added bile acid (50 and 200 micromol/L) was 95.57 and 85.46% in serum and 97.6 and 91.6% in bile, respectively. Within- and between-batch coefficients of variation (CV) for bile acid determination were <1.2 and <0.2% in serum and >0.1 and <0.1% in bile, respectively. Good correlations for bile acid in serum (r1=0.92) and in bile (r2=0.97) were obtained by use of a standard chemical method and the present method. The mixture of immobilized 3alpha-HSD dehydrogenase and lipoyl dehydrogenase lost 50% of its initial activity after 6 months of regular use. The cost of bile acid determination in 100 serum and bile samples by the present method has been compared with that of the Sigma kit method.

3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)↗

Sodium valproate for painful diabetic neuropathy: a randomized double-blind placebo-controlled study.

BACKGROUND: Various drugs are effective in the management of painful diabetic neuropathy, but none is completely satisfactory. We previously found sodium valproate to be effective and safe in a short-term study. AIM: To test the effectiveness and safety of sodium valproate in the management of painful diabetic neuropathy over 3 months. DESIGN: Randomized double-blind placebo-controlled study. METHODS: Consecutive attending patients with type 2 diabetes mellitus with painful neuropathy were asked to participate in the trial: 48 agreed. Five were excluded: three with HbA(1c) > 11, one with too low a pain level and one who withdrew consent. The remaining 43 were given either drug (group A) or placebo (group B). Each patient was assessed clinically. Quantitative assessment of pain was done by McGill Pain Questionnaire, Visual Analogue Score and Present Pain Intensity, at the beginning of the study, after 1 month and after 3 months. Motor and sensory nerve conduction velocities were measured initially and after 3 months. Liver function tests and other adverse drug-related effects were assessed periodically. RESULTS: Of the 43 patients, four dropped out: one in group A and three in group B. There was significant improvement in pain score in group A, compared to group B, at 3 months (p < 0.001). Changes in electrophysiological data were not significant. The drug was well-tolerated by all patients, except one, who had raised serum AST and ALT levels after 1 month of treatment, and whose treatment was discontinued. DISCUSSION: Sodium valproate is well-tolerated, and provides significant subjective improvement in painful diabetic neuropathy.

Adult↗

Diagnosis of herpes simplex virus-1 keratitis using Giemsa stain, immunofluorescence assay, and polymerase chain reaction assay on corneal scrapings.

AIMS: To evaluate three tests used routinely for the diagnosis of herpes simplex virus (HSV) keratitis. METHODS: Corneal scrapings from 28 patients with clinically typical dendritic corneal ulcer suggestive of HSV keratitis, and 30 patients with clinically non-viral corneal ulcers, were tested by (i) Giemsa stain for multinucleated giant cells, (ii) immunofluorescence assay (IFA) for HSV-1 antigen, and (iii) polymerase chain reaction (PCR) for HSV-1 DNA, by investigators masked to clinical diagnosis. The control subjects were also investigated by smears and cultures for bacteria, fungus, and Acanthamoeba. RESULTS: The specificity and positive predictive values of all three tests for the diagnosis of HSV keratitis were between 95-100%. The sensitivity of IFA and PCR was 78.6% and 81.2%, respectively, and the difference was not significant; however, their sensitivity and negative predictive value were significantly higher than Giemsa stain. CONCLUSIONS: While a combination of IFA and PCR constitute the choice of tests in clinically suspected cases of HSV keratitis, multinucleated giant cells in Giemsa stain can pre-empt testing by IFA and PCR in otherwise atypical cases of HSV keratitis.

Adolescent↗

A study of prevalence of health problems in asymptomatic elderly individuals in Delhi.

A survey was conducted in asymptomatic aged individuals (> or = 60 years) in The National Capital Territory of Delhi for the prevalence of major health problems like hypertension, diabetes mellitus and respiratory diseases. A total of 200 individuals (100 males and 100 females) were studied over a period of three months in 1998-99. Hypertension was defined as BP > or = 140/90 mmHg (JNC VI criteria), while diabetes mellitus was diagnosed if fasting whole blood sugar was 120 mg/dl or more (WHO criteria). Diagnosis of other health problems was based on relevant history and physical examination. Prevalence of hypertension in the study group was 32.5 per cent (more in males). Of these 18 per cent and 4.2 per cent had isolated systolic and diastolic hypertension, respectively. Prevalence of diabetes mellitus in the same population was 13.0 per cent. Both diseases were more prevalent in urban population. A high prevalence of respiratory disorders was observed (pulmonary tuberculosis 16 per cent, COPD 10 per cent, asthma 4.5 per cent). Cataract was present in 7.5 per cent while 1.5 per cent had symptoms of urinary tract infection. History of Jaundice was present in 3.5 per cent. Three per cent each had a history suggestive of IHD and TIA, respectively. Proteinuria and glycosuria was seen in 22.2 and 7.6 percent, respectively. A large percentage of the study group (34.4 per cent) had asymptomatic ECG abnormalities.

Aged↗

Correlation between chemical composition of biliary calculi and sera of stone formers.

A quantitative chemical analysis of total cholesterol, bilirubin, calcium, inorganic phosphate and iron of three types of biliary calculi (cholesterol, pigment and mixed) of 40 gall stone former was carried out and correlated to with those of there sera. A moderately positive correlation for inorganic phosphate, Ca2+ and Fe2+ content of sera and calculi of cholesterol stone patient was found. A Good positive correlation for total cholesterol, a moderately positive correlation for bilirubin and iron but no correlation for inorganic phosphate and calcium content of sera and calculi of pigment stone patient was observed. A good moderately positive correlation for iron but no correlation for total cholesterol, bilirubin, inorganic phosphate and Ca2+ content of sera and calculi of stone patient was found.

Bilirubin↗

Atypical Herpes simplex keratitis (HSK) presenting as a perforated corneal ulcer with a large infiltrate in a contact lens wearer: multinucleated giant cells in the Giemsa smear offered a clue to the diagnosis.

PURPOSE: To report a case of atypical herpes simplex keratitis initially diagnosed as bacterial keratitis, in a contact lens wearer. RESULTS: Case report of an 18-year-old woman using contact lenses who presented with pain, redness and gradual decrease in vision in the right eye. Examination revealed a paracentral large stromal infiltrate with a central 2-mm perforation. Corneal and conjunctival scrapings were collected for microbiological investigations. Corneal tissue was obtained following penetrating keratoplasty. Corneal scraping revealed no microorganisms. Giemsa stained smear showed multinucleated giant cells. Conjunctival, corneal scrapings and tissue were positive for herpes simplex virus - 1 (HSV) antigen. Corneal tissue was positive for HSV DNA by PCR. CONCLUSIONS: Atypical HSV keratitis can occur in contact lens wearers. A simple investigation like Giemsa stain may offer a clue to the diagnosis.

Acyclovir↗

Reproducibility of in vivo brain measures of 5-HT2A receptors with PET and.

The test/retest reproducibility of brain measures of 5-HT2A receptors with positron emission tomography (PET) and [18F]deuteroaltanserin was examined in a group of eight healthy human subjects. PET measures of 5-HT2A receptors were obtained under an equilibrium paradigm, with a 40-min PET acquisition starting approximately at 300 min (308+/-11 min) after bolus plus constant infusion of the radiotracer. Three brain outcome measures were obtained at equilibrium, V(3) (ratio of specific brain uptake to free parent plasma concentration of radiotracer), V(3)' (ratio of specific brain uptake to total parent plasma concentration) and RT (ratio of specific to non-displaceable brain uptakes). V(3)' and RT had high test/retest reproducibility, as measured by mean intra-subject% change for cortical brain areas of 14.1 and 11.0%, respectively. They also had high reliability, as measured by mean intra-class correlation coefficients (ICC) for cortical brain areas of 0.86 and 0.88, respectively. V(3) had low test/retest reproducibility, due to high variability in the measures of free parent tracer in plasma. This study supports the feasibility of equilibrium imaging of 5-HT2A receptors with PET and [18F]deuteroaltanserin. The equilibrium imaging method with [18F]deuteroaltanserin allows a single acquisition and blood measurement to provide an image whose pixel values equal a receptor volume of distribution. Since the single image pixel values are proportional to receptor densities, the images can be used in pixel-by-pixel statistical methods, such as SPM, to assess the distribution and density of 5-HT2A receptors in neuropsychiatric disorders.

Adult↗

Epithelial infectious crystalline keratopathy.

PURPOSE: To report 2 cases of epithelial infectious crystalline keratopathy. METHODS: Two patients (2 eyes) with significant meibomitis presented with minimal inflammation and plaque-like lesions on the corneal surface made of fine crystalline structures. Corneal scrapings of these lesions were performed for microbiological evaluation. The patients were treated with topical ciprofloxacin and artificial tears. RESULTS: Smear examination of the corneal scrapings revealed numerous bacteria and keratinized epithelial cells with no inflammatory cells. Culture showed a significant growth of Staphylococcus epidermidis and Corynebacterium species in the first case and Pseudomonas aeroginosa in the second case. The response to treatment was poor, with recurrence of the crystalline lesion. CONCLUSION: Infectious crystalline keratopathy lesions may involve the epithelium and occur on the corneal surface.

Adult↗

Bilateral infectious keratitis after laser in situ keratomileusis: a case report and review of the literature.

OBJECTIVE: To report a case of bilateral infectious keratitis after simultaneous bilateral laser in situ keratomileusis (LASIK) and to explore appropriate preventive, diagnostic, and therapeutic measures. DESIGN: Interventional case report and literature review. INTERVENTION: A 22-year-old woman had bilateral corneal infiltrates after simultaneous bilateral LASIK. The same set of instruments was used for surgery on both eyes. Corneal scrapings from the edge of the infiltrate and underneath the flap were taken for microscopic examination and inoculation on culture media. Treatment consisted of irrigation of stromal bed with amikacin sulphate (2.5%) solution along with half hourly instillation of amikacin (2.5%) and cefazolin (5%) eye drops. MAIN OUTCOME MEASURES: Causative organism and response to medical treatment. RESULTS: Culture revealed a significant growth of Mycobacterium chelonae from the corneal scrapings of both eyes. There was progressive thinning of corneal stroma in the right eye requiring cyanoacrylate tissue adhesive application. The left eye showed progressive worsening after initial response and required penetrating keratoplasty. CONCLUSIONS: The risk of bilateral sight-threatening complications must be kept in mind when contemplating bilateral simultaneous LASIK. Nontuberculous mycobacteria should be considered as an etiologic agent in cases of infectious keratitis occurring after LASIK. Microbiology work-up of a specimen collected directly from the site of lesion can help in early diagnosis and institution of appropriate therapy.

Adult↗

Comparison of [(18)F]altanserin and [(18)F]deuteroaltanserin for PET imaging of serotonin(2A) receptors in baboon brain: pharmacological studies.

The regional distribution in brain, distribution volumes, and pharmacological specificity of the PET 5-HT(2A) receptor radiotracer [(18)F]deuteroaltanserin were evaluated and compared to those of its non-deuterated derivative [(18)F]altanserin. Both radiotracers were administered to baboons by bolus plus constant infusion and PET images were acquired up to 8 h. The time-activity curves for both tracers stabilized between 4 and 6 h. The ratio of total and free parent to metabolites was not significantly different between radiotracers; nevertheless, total cortical R(T) (equilibrium ratio of specific to nondisplaceable brain uptake) was significantly higher (34-78%) for [(18)F]deuteroaltanserin than for [(18)F]altanserin. In contrast, the binding potential (Bmax/K(D)) was similar between radiotracers. [(18)F]Deuteroaltanserin cortical activity was displaced by the 5-HT(2A) receptor antagonist SR 46349B but was not altered by changes in endogenous 5-HT induced by fenfluramine. These findings suggest that [(18)F]deuteroaltanserin is essentially equivalent to [(18)F]altanserin for 5-HT(2A) receptor imaging in the baboon.

Analysis of Variance↗