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Biomedical subjects

S Kaushik

Publications and source records attributed to S Kaushik.

At least 37 records · Page 2Linked to original sources

Removal of fat from cow's milk decreases the vitamin E contents of the resulting dairy products.

The present study was undertaken to determine whether decreases in fat contents result in lower vitamin E contents. Milk samples of varying fat contents (half and half, whole milk, reduced-fat milk, low-fat milk, and nonfat milk) were obtained from a local dairy on six different occasions. alpha-Tocopherol was the major form of vitamin E (>85%); gamma-tocopherol and alpha-tocotrienol were present to a lesser extent. As the fat contents of milk products decreased from 11 to 0.3%, the vitamin E contents decreased. For example, raw milk as compared to nonfat milk had both higher (-tocopherol contents (45.5 +/- 4.6 vs. 4.5 +/- 0.5 microg/100 g; P < or = 0.0001) and higher total lipids (3.46 +/- 0.49 vs. 0.30 +/- 0.07 g/100 g; P < or = 0.0001). Vitamin E, cholesterol, and total lipids increased as cream was added back to nonfat milk during production. For every 1 mg cholesterol increase, there was an increase of approximately 4 microg of alpha-tocopherol; for every 1 g total lipids increase, the alpha-tocopherol content increased by 17 microg. These data demonstrate that removal of milk fat markedly decreases the vitamin E content of various milk products.

Animals↗

Curvularia lunata endophthalmitis with secondary keratitis.

PURPOSE: To report a case of pseudophakic endophthalmitis with secondary keratitis caused by Curvularia lunata. METHODS: A 40-year-old man presented with a fluffy mass in the anterior chamber with low-grade delayed postoperative inflammation in the right eye. RESULTS: The anterior chamber and vitreous aspirate demonstrated C. lunata. A large corneal infiltrate developed after aspiration of the mass. Treatment with systemic, topical, and intraocular antifungal agents cleared the vitreous, but the cornea perforated. CONCLUSION: Delayed low-grade infection with a fluffy mass in the anterior chamber after cataract surgery can rarely be a clinical presentation of dematiaceous fungal infection. Secondary keratitis may result after a diagnostic aspiration.

Adult↗

Acute pulmonary toxicity after low-dose amiodarone therapy.

Amiodarone-induced pulmonary toxicity is usually seen in cardiac surgical patients who have received large doses of amiodarone for ventricular arrhythmias over prolonged periods. In this report, we describe a case of amiodarone-induced pulmonary toxicity after a short course of therapy for postoperative atrial fibrillation.

Acute Disease↗

Contrast sensitivity and depth of focus with aspheric multifocal versus conventional monofocal intraocular lens.

BACKGROUND: Laboratoires Domilens, Lyon, France, has introduced a new aspheric multifocal intraocular lens (IOL), the Progress 3. The central portion, measuring 4.7 mm in diameter, has an anterior surface of progressively increasing power, such that there is a central add of +5.00 dioptres. We compared contrast sensitivity and depth of focus in patients who received the Progress 3 and in those who received a conventional monofocal IOL. METHODS: Prospective study. Forty patients with age-related cataract were randomly divided into two groups: 20 patients received the Progress 3 aspheric multifocal IOL, and 20 patients received a conventional monofocal IOL of similar design. Contrast sensitivity was measured with the Pelli-Robson letter-based chart. Depth of focus was determined by dialling a series of overcorrections over the patient's manifest refraction until the patient read 6/12 clearly. The depth of focus was defined as the range over which 6/12 or better acuity was achieved. Quality of vision was evaluated by patient questionnaire. RESULTS: Mean contrast sensitivity was significantly lower in the patients with a multifocal IOL than in those with a monofocal IOL (1.38 vs. 1.56 log units) (p < 0.001). The mean depth of focus values for the two groups were 3.10 D and 1.65 D respectively (p < 0.001). The prevalence of subjective problems was similar in the two groups. INTERPRETATION: In our opinion, aspheric multifocal IOLs should be reserved for patients who are willing to trade increased depth of focus for reduced contrast sensitivity postoperatively.

Cataract Extraction↗

Glucokinase is highly induced and glucose-6-phosphatase poorly repressed in liver of rainbow trout (Oncorhynchus mykiss) by a single meal with glucose.

The low dietary starch utilisation by rainbow trout (Oncorhynchus mykiss) may be attributed to a dysfunction of the nutritional regulation of the hepatic glucose/glucose-6-phosphate cycle. The present study was initiated to analyse the regulation of activity and gene expression of hepatic glucokinase (GK) and glucose-6-phosphatase (G6Pase) by dietary carbohydrates in this species. We found that even a single meal containing 24% of glucose is sufficient to induce the GK expression (mRNA and activity) as in mammals. In contrast, although the inhibitory effect of dietary glucose on G6Pase expression is observed at the molecular level, the G6Pase activity is not significantly inhibited by dietary glucose. Thus, in contrast to the gluconeogenic G6Pase enzyme, a rapid adaptation of the hepatic glycolytic GK enzyme to dietary glucose seems effective in rainbow trout. These results suggest that in carnivorous rainbow trout, the liver is capable to strongly regulate the utilisation of glucose but not the synthesis of glucose.

Animals↗

Cloning, tissue distribution and nutritional regulation of a Delta6-desaturase-like enzyme in rainbow trout.

This report describes the cloning, nutritional regulation and tissue distribution of a desaturase-like enzyme in rainbow trout (Oncorhynchus mykiss). The open reading frame of the trout desaturase-like cDNA encodes a 454-amino acid peptide that contains two membrane-spanning domains, three histidine-rich regions and a cytochrome b5 domain, which all align perfectly with the same domains located in other recently identified vertebrate Delta5- and Delta6-desaturases. Nutritional regulation of trout desaturase-like gene expression, as well as the tissue expression profile, are also similar to those observed in other vertebrate Delta5- and Delta6-desaturases. Finally, the sequence alignments between the predicted protein sequence of rainbow trout desaturase-like and other Delta6- and Delta5-desaturases revealed a high percentage identity with Delta6-desaturases (64-66% identity with vertebrate Delta6-desaturases). These results demonstrate for the first time the presence and nutritional modulation of a Delta6-desaturase-like cDNA in rainbow trout.

Amino Acid Sequence↗

Ontogenesis of hexokinase I and hexokinase IV (glucokinase) gene expressions in common carp (Cyprinus carpio) related to diet.

The expressions of hexokinase IV (glucokinase, GK) and hexokinase (HK)-I genes were analysed during early ontogenesis of common carp (Cyprinus carpio). Unlike HK-I gene, which was expressed during all the stages of the development, GK was only induced by the first feeding with high levels of dextrin as a source of carbohydrate. This study confirms the high capacity of common carp to use glucose even at the very early stages of development.

Animal Nutritional Physiological Phenomena↗

Intracameral amphotericin B: initial experience in severe keratomycosis.

PURPOSE: Fungal keratitis is a significant cause of ocular morbidity in India. The most commonly implicated fungi are Aspergillus spp. Patients often present with hypopyon, which usually contains fungal elements. The treatment is difficult owing to poor intraocular penetration of most available antifungal agents. This study evaluated the results of intracameral injection of amphotericin B in natamycin resistant cases of severe keratomycosis. METHODS: Three patients of culture proven Aspergillus flavus corneal ulcer with hypopyon not responding to topical natamycin 5%, amphotericin B 0.15%, and oral itraconazole were administered intracameral amphotericin B. The first case received 7.5 microg in 0.1 mL followed by two subsequent injections of 10 microg in 0.1 mL each, the second case received two injections of 10 microg in 0.1 mL, and the third patient received a single dose of 10 microg in 0.1 mL. Culture of the aqueous sample also grew A. flavus in all three cases. RESULTS: All three cases responded favorably, with the ulcer and hypopyon clearing completely. There was no clinical evidence of corneal or lenticular toxicity in any patient. CONCLUSIONS: Intracameral amphotericin B may be a useful modality in the treatment of severe keratomycosis not responding to topical natamycin. It ensures adequate drug delivery into the anterior chamber and may be especially useful to avoid surgical intervention in the acute stage of the disease.

Adult↗

Effect of a subanesthetic dose of intravenous ketamine and/or local anesthetic infiltration on hemodynamic responses to skull-pin placement: a prospective, placebo-controlled, randomized, double-blind study.

Insertion of cranial pins for stabilization of the head can result in a marked hypertensive response, which may adversely affect cerebral hemodynamics. The efficacy of a subanesthetic dose of intravenous ketamine (0.5 mg/kg) and/or lidocaine infiltration (1%) at pin fixation sites before pinning was studied in a prospective, double-blind, placebo-controlled, randomized trial of 40 patients. The subjects were divided into four groups of 10. Patients belonging to the placebo and lidocaine groups received intravenous normal saline (NS), followed by local infiltration with NS at pin insertion sites in the placebo group and 1% lidocaine in the lidocaine group. Patients belonging to the ketamine and ketamine-lidocaine groups received intravenous ketamine followed by local infiltration with NS in the ketamine group, and lidocaine infiltration in the ketamine-lidocaine group. Heart rate (HR) and invasive mean blood pressure (MBP) were recorded before intravenous medication and then at various time intervals until 15 minutes after pin fixation. Intergroup comparison of MBP and HR by 2-way analysis of variance revealed a significant difference between the groups and various time points (P < .05). Post hoc analysis revealed maximum increase in MBP each hour in the placebo group. Mean blood pressure response in the ketamine group was similar to the placebo group. Significant attenuation of MBP and HR was observed in the lidocaine and ketamine-lidocaine groups (P < .05). A minimal increase in HR was observed in the lidocaine-ketamine group. The current study demonstrates maximum attenuation of hemodynamic responses when a subanesthetic dose of intravenous ketamine (0.5 mg/kg) is administered with 1% lidocaine infiltration.

Adolescent↗

Abdominal thrombotic and ischemic manifestations of the antiphospholipid antibody syndrome: CT findings in 42 patients.

PURPOSE: To determine the abdominal computed tomographic (CT) findings in patients with antiphospholipid antibody syndrome (APS). MATERIALS AND METHODS: Retrospective review of medical records from two university medical centers from 1994 through 1997 revealed 215 patients who had a hypercoagulable state attributed to primary or secondary APS. Abdominal CT findings in these patients were reviewed for evidence of large-vessel occlusion or visceral ischemia. RESULTS: In 42 (19.5%) of 215 patients with APS (age range, 32-65 years; mean age, 42 years), abdominal thromboses or ischemic events were detected at CT. Twenty-two (52%) had major vascular thromboses, including those in the inferior vena cava (n = 10), portal and superior mesenteric veins (n = 7), splenic vein (n = 4), and aorta (n = 1). Thirty-six (86%) patients had abdominal visceral ischemia resulting in renal infarction (n = 22), bowel ischemia (n = 13), splenic infarction (n = 6), pancreatitis (n = 3), hepatic infarction (n = 1), and/or hepatic dysfunction with portal hypertension (n = 1). In some patients, more than one abdominal organ and/or vessel was involved. CONCLUSION: Patients who have circulating antiphospholipid antibodies are at risk for major abdominal vascular thromboses and organ infarction. Radiologists must be familiar with this syndrome; they may be the first physicians to suggest the diagnosis on the basis of findings of unusual or recurrent sites of thrombosis, especially in young patients.

Abdomen↗

Nutritional regulation and tissue specificity of gene expression for proteins involved in hepatic glucose metabolism in rainbow trout (Oncorhynchus mykiss).

Rainbow trout (Oncorhynchus mykiss) are known to use dietary carbohydrates poorly. One of the hypotheses to explain the poor utilisation of dietary glucose by these fish is a dysfunction in nutritional regulation of hepatic glucose metabolism. In this study, we obtained partial clones of rainbow trout cDNAs coding for a glucose transporter (Glut2), and for the enzymes 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (6PF-2K/F-2,6BPase), fructose-1,6-bisphosphatase (FBPase) and pyruvate kinase (PK). Their deduced amino acid sequences were highly similar to those of mammals (up to 80% similarity). In a study of nutritional regulation, the Glut2 gene was highly expressed in the liver irrespective of the nutritional status of the trout, in agreement with the role of this transporter in the input (during refeeding) and output (during fasting) of glucose from the liver. Moreover, whereas PK and FBPase gene expression was high irrespective of the nutritional status, levels of hepatic 6PF-2K/F-2,6BPase mRNA were higher in fish fed with carbohydrates than in fish deprived of food. The high levels of hepatic PK, Glut2 and 6PF-2K/F-2,6BPase gene expression observed in this study suggest a high potential for tissue carbohydrate utilisation in rainbow trout. The persistence of a high level of FBPase gene expression suggests an absence of regulation of the gluconeogenic pathway by dietary carbohydrates.

Amino Acid Sequence↗

Hepatic phosphoenolpyruvate carboxykinase gene expression is not repressed by dietary carbohydrates in rainbow trout (Oncorhynchus mykiss).

Phosphoenolpyruvate carboxykinase (PEPCK) is a rate-limiting enzyme in hepatic gluconeogenesis and therefore plays a central role in glucose homeostasis. The aim of this study was to analyse the nutritional regulation of PEPCK gene expression in rainbow trout (Oncorhynchus mykiss), which are known to use dietary carbohydrates poorly. A full-length hepatic PEPCK cDNA (2637 base pairs with one open reading frame putatively encoding a 635-residue protein) was cloned and found to be highly homologous to mammalian PEPCKs. The presence of a putative peptide signal specific to a mitochondrial-type PEPCK in the deduced amino acid sequence suggests that this PEPCK gene codes for a mitochondrial form. In gluconeogenic tissues such as liver, kidney and intestine, this PEPCK gene was expressed at high levels and, in the liver we found no regulation of PEPCK gene expression by dietary carbohydrates. These results suggest that the first step of the hepatic gluconeogenic pathway in rainbow trout is functional and highly active irrespective of the dietary carbohydrate supply.

Amino Acid Sequence↗

Effect of chondrocalcinosis on the MR imaging of knee menisci.

OBJECTIVE: Our goal was to determine the influence of chondrocalcinosis on MR imaging in the detection of meniscal tears. MATERIALS AND METHODS: A retrospective review was performed of knee MR imaging and arthroscopy records from two university hospitals between 1996 and 1998. Seventy individuals had radiographic evidence of chondrocalcinosis and underwent knee MR imaging. Thirty-seven of these individuals had undergone arthroscopy for further evaluation of their symptoms. MR imaging sensitivity and specificity in the detection of medial and lateral meniscal tears were calculated in these 37 patients who had radiographic evidence of chondrocalcinosis and in a control group of 34 patients who underwent MR imaging and arthroscopy but did not have knee chondrocalcinosis. RESULTS: In the chondrocalcinosis group, MR imaging sensitivity, specificity, and accuracy for meniscal tear were 78%, 71%, and 78%, respectively, for the lateral meniscus, and 89%, 72%, and 81% for the medial meniscus. The control group showed sensitivity, specificity, and accuracy of 93%, 100%, and 97%, respectively, for the lateral meniscus and 100% in all cases for the medial meniscus. The MR imaging detection of meniscal tears in both the lateral and medial compartments combined is significantly poorer in the presence of chondrocalcinosis (p < 0.005). CONCLUSION: MR imaging sensitivity and specificity for detection of meniscal tear is decreased in the presence of meniscal chondrocalcinosis. Chondrocalcinosis appeared as a high-signal-intensity region on T1-weighted, intermediate-weighted, and inversion recovery sequences. The high signal of chondrocalcinosis on inversion recovery sequence is an interesting observation that to our knowledge has not been previously reported. Radiographic correlation with the MR imaging examination can help prevent overdiagnosing meniscal tears.

Adult↗