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Patel AB, Pal R, Dewan A. Distribution profile of paraoxonase phenotypes among the Gujaratis. INDIAN JOURNAL OF HUMAN GENETICS 2011; 13:65-8. [PMID: 21957348 PMCID: PMC3168161 DOI: 10.4103/0971-6866.34709] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND: Paraoxonase (PON1) can hydrolyze organophosphate pesticides (OP) and has a key role in the susceptibility of human in OP toxicity. The human-enzyme shows polymorphism and variations in the distribution profile of its phenotypes among different ethnic groups have been observed. AIMS: To see the distribution pattern of total PON1 activity in 45 healthy attendants of poisoning cases; 121 healthy unrelated farm-labours and 59 normal subjects of trauma. MATERIALS AND METHODS: The PON1 activities from serum/plasma samples of these healthy normal individuals were estimated with/without addition of 1M NaCl in order to determine salt-stimulated and basal activity. The PON 1 phenotypes were determined on the basis of percent activation of enzyme activity. RESULTS: Tri-modal distribution of basal PON1 activity was observed among all these individuals. 52.0% of the individuals belonged to Phenotype A, 46.6% to phenotype AB while 1.4% to Phenotype B with gene frequency of allele-A and allele-B being 0.753 and 0.247 respectively in excellent agreement with Hardy-Weinberg equilibrium. CONCLUSION: Maximum number of individuals belonged to phenotype-A (low PON1 activity) showing potential vulnerability towards Op-poisoning.
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Abstract
A 10 year old girl presented with clinical signs and symptoms of the triad of niacin deficiency namely skin eruptions, ataxia, mental changes and diarrhea. Although this deficiency could be nutritional where maize is a staple diet, this patient had neutral aminoaciduria which indicated a defective transport of neutral amino acid transporter in the kidneys and intestine resulting in failure of transport of tryptophan and other neutral (ie, monoaminomonocarboxylic) alpha-amino acids in the small intestine and the renal tubules.
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Patel AB, Prabhu AS. Determinants of lead level in umbilical cord blood. Indian Pediatr 2009; 46:791-793. [PMID: 19213980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Accepted: 07/31/2008] [Indexed: 05/27/2023]
Abstract
Lead levels were measured by atomic absorption spectrophotometry in umbilical cord blood samples of 205 consecutively born neonates and venous blood in 62 of the mothers. The mean (+/- SD) cord blood lead level was 4.7 +/- 12.1 microg/dL. In the sub sample of 62 mother-baby pairs, the mean (+/- SD) cord blood lead levels were 1.6 +/- 2.5 microg/dL and 2.0 +/- 2.1 microg/dL, respectively. According to CDC risk categories, 92% babies were in Class I of which 87% had lead levels below 5 microg/dL. The mean (+/- SD) birthweight in <5 microg/dL category was 2640 +/- 445 grams as compared to 2617 +/- 408 grams in >5 microg/dL category. The mean (+/- SD) gestational ages were 39.1 +/- 2.0 weeks and 38.1 +/- 2.0 weeks, respectively in the two groups (P=0.014). On multivariate linear analysis, lower gestational age significantly correlated with higher cord blood lead level.
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Stasiw RO, Zaun JW, Patel AB, Brown HD. Microcalorimetric study of binding by lysozyme of N-acetyl glucosamine oligomers. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 2009; 5:11-7. [PMID: 4763351 DOI: 10.1111/j.1399-3011.1973.tb02313.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Gandhi CD, Meyer SA, Patel AB, Johnson DM, Post KD. Neurologic complications of inferior petrosal sinus sampling. AJNR Am J Neuroradiol 2008; 29:760-5. [PMID: 18238844 DOI: 10.3174/ajnr.a0930] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE Inferior petrosal sinus sampling (IPSS) is a useful diagnostic technique in adrenocorticotropic hormone (ACTH)-dependent hypercortisolism with normal or equivocal MR imaging. The procedure is believed to be safe, with mostly minor complications. However, there are rare, but severe, neurologic complications that need to be considered. MATERIALS AND METHODS We performed an institutional review board-approved retrospective review of our institutional IPSS experience from July 2001 to January 2007. IPSS was performed for the evaluation of Cushing disease. The end points of particular interest were the indications for IPSS and the incidence of associated complications. RESULTS During the study period of 5(1/2) years, 44 patients underwent IPSS for evaluation of Cushing disease. There were 33 women and 11 men with a mean age of 43.1 years. Because of equivocal imaging and endocrine testing, 36 of 44 patients underwent IPSS, and 8 of 44 underwent IPSS after failed transsphenoidal exploration. The only complication was injury to the brain stem that occurred after an unremarkable procedure in a 42-year-old woman. She developed clinical evidence of pontomedullary dysfunction with MR imaging consistent with brain stem infarction. The cause of this injury is unclear, but a venous variant leading to transient venous hypertension or thrombosis is suspected. CONCLUSION Neurologic injury is a rare but serious complication associated with IPSS. Despite this, if performed under a strict paradigm, IPSS is both accurate and safe and can be very useful in the management of Cushing disease.
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Gilad R, Fatterpekar GM, Johnson DM, Patel AB. Migrating subdural hematoma without subarachnoid hemorrhage in the case of a patient with a ruptured aneurysm in the intrasellar anterior communicating artery. AJNR Am J Neuroradiol 2007; 28:2014-6. [PMID: 17921232 DOI: 10.3174/ajnr.a0726] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Acute spontaneous subdural hematoma without the presence of a subarachnoid hemorrhage as a result of a ruptured aneurysm is rare. We present the case of a patient with an aneurysm of the intrasellar anterior communicating artery that caused hemorrhage solely into the subdural space. The hemorrhage then migrated down the spinal canal. Our case is unique because all these 3 rare processes occurred in a single patient. Identification of the cause of this type of hemorrhage in a timely fashion is crucial to the management of such a patient.
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Chowdhury GMI, Gupta M, Gibson KM, Patel AB, Behar KL. Altered cerebral glucose and acetate metabolism in succinic semialdehyde dehydrogenase-deficient mice: evidence for glial dysfunction and reduced glutamate/glutamine cycling. J Neurochem 2007; 103:2077-91. [PMID: 17854388 DOI: 10.1111/j.1471-4159.2007.04887.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Succinic semialdehyde dehydrogenase (SSADH) catalyzes the NADP-dependent oxidation of succinic semialdehyde to succinate, the final step of the GABA shunt pathway. SSADH deficiency in humans is associated with excessive elevation of GABA and gamma-hydroxybutyrate (GHB). Recent studies of SSADH-null mice show that elevated GABA and GHB are accompanied by reduced glutamine, a known precursor of the neurotransmitters glutamate and GABA. In this study, cerebral metabolism was investigated in urethane-anesthetized SSADH-null and wild-type 17-day-old mice by intraperitoneal infusion of [1,6-(13)C(2)]glucose or [2-(13)C]acetate for different periods. Cortical extracts were prepared and measured using high-resolution (1)H-[(13)C] NMR spectroscopy. Compared with wild-type, levels of GABA, GHB, aspartate, and alanine were significantly higher in SSADH-null cortex, whereas glutamate, glutamine, and taurine were lower. (13)C Labeling from [1,6-(13)C(2)]glucose, which is metabolized in neurons and glia, was significantly lower (expressed as mumol of (13)C incorporated per gram of brain tissue) for glutamate-(C4,C3), glutamine-C4, succinate-(C3/2), and aspartate-C3 in SSADH-null cortex, whereas Ala-C3 was higher and GABA-C2 unchanged. (13)C Labeling from [2-(13)C]acetate, a glial substrate, was lower mainly in glutamine-C4 and glutamate-(C4,C3). GHB was labeled by both substrates in SSADH-null mice consistent with GABA as precursor. Our findings indicate that SSADH deficiency is associated with major alterations in glutamate and glutamine metabolism in glia and neurons with surprisingly lesser effects on GABA synthesis.
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Wilson L, Patel AB. Renal colic during sexual intercourse: a unique presentation. ACTA ACUST UNITED AC 2006; 34:225-6. [PMID: 16477426 DOI: 10.1007/s00240-006-0039-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Accepted: 01/12/2006] [Indexed: 10/25/2022]
Abstract
The average lifetime risk of renal stones has been reported to be in the range of 5-21%, and the majority of patients have recurrent stones (Tiselius et al. in Eur Urol 40:362-371, 2001). The peak incidence is between the fourth and fifth decades, and therefore generally active and working adults are most affected. Stones are usually formed in a calyx, and become symptomatic if they move to obstruct the upper urinary tract. In the majority of cases, there is no specific action which causes stone movement from a non-obstructing to an obstructing position. We present the first ever case report in the literature of an episode of renal colic during sexual intercourse. The role of percussion therapy and postural drainage are well established following shockwave lithotripsy (SWL) to enhance passage of lower pole stone fragments (Brownlee et al. in J Urol 143:1096, 1990), and it may well be the result of similar principles of motion and body positioning which caused the patient to present in this manner.
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Patel AB, Wilson L, Rane A. Occult Leydig Cell Tumour Presenting as Bilateral Gynaecomastia. Case Report and Literature Review. ScientificWorldJournal 2005; 5:884-887. [PMID: 29861682 PMCID: PMC5936502 DOI: 10.1100/tsw.2005.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 09/30/2005] [Accepted: 10/14/2005] [Indexed: 11/17/2022] Open
Abstract
Gynaecomastia is the most common benign breast disorder in men. Among the various causes, testicular malignancies are an uncommon, life-threatening condition requiring prompt diagnosis and treatment. The case of a 28-year-old man is discussed, who presented with a 6-month history of painful bilateral gynaecomastia with no abnormality on clinical or biochemical examination. The patient's symptoms spontaneously resolved within 4 weeks. He then represented 10 years later with similar symptoms and an associated secondary hypogonadism. Ultrasound imaging revealed a clinically occult, hypoechoic mass in the left testis (Leydig cell tumour on histology). Clinical and hormonal findings normalized following surgical excision. This report underlines the importance in clinical practice of ultrasonographic evaluation of the testis, in all patients with gynaecomastia, despite unremarkable findings on physical examination.
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Patel AB, Wilson L, Blick C, Meffan P. Paraneoplastic hypercalcaemia associated with TCC of bladder. ScientificWorldJournal 2004; 4:1069-70. [PMID: 15632985 PMCID: PMC5956393 DOI: 10.1100/tsw.2004.187] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Patel AB, Renge RL. William's syndrome. Indian Pediatr 2001; 38:1427. [PMID: 11752746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Patel AB, Rothman DL, Cline GW, Behar KL. Glutamine is the major precursor for GABA synthesis in rat neocortex in vivo following acute GABA-transaminase inhibition. Brain Res 2001; 919:207-20. [PMID: 11701133 DOI: 10.1016/s0006-8993(01)03015-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objective of the present study was to assess the degree to which astrocytic glutamine provides carbon for net synthesis of GABA in the rat neocortex in vivo. Isotopic labeling of GABA and glutamate from astrocytic glutamine was followed in halothane anesthetized and ventilated rats during an intravenous infusion of [2-(13)C]glucose. A net increase in GABA was achieved by administration of the GABA-transaminase inhibitor, gabaculine to suppress catabolism of GABA and recycling of (13)C label. (13)C Percentage enrichments of GABA, glutamate and glutamine were assessed in tissue extracts using (13)C-edited (1)H nuclear magnetic resonance at 8.4 T. GABA levels increased 2.6 micromol/g at 2 h and 6.1 micromol/g at 5 h after gabaculine, whereas glutamate and glutamine decreased in toto by 5.6 micromol/g at 2 h and 3.1 micromol/g at 5 h. Selective enrichment of glutamine, glutamate, and GABA C3's over other carbon positions was observed consistent with a precursor role for astrocytic glutamine. Between 1 h (control) and 3 h (gabaculine-treated) of [2-(13)C]glucose infusion, (13)C percentage enrichment increased in glutamine C3 (from 3.2+/-0.5 to 7.0+/-0.9%), glutamate C3 (from 1.8+/-0.5 to 3.4+/-0.9%), and GABA C3 (from 2.7+/-1.6 to 4.8+/-0.4%). The measured incremental [3-(13)C]GABA concentration (0.15 micromol/g) was close to the predicted value (0.13 micromol/g) that would be expected if the increase in GABA were produced entirely from glutamine compared to glutamate (0.07 micromol/g) based on the average precursor enrichments between 1 and 3 h. We conclude that glutamine is the major source of GABA carbon in the rat neocortex produced acutely following GABA-T inhibition by gabaculine in vivo.
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Renge RL, Patel AB. Neonatal tetanus. Indian Pediatr 2001; 38:1316. [PMID: 11721078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Patel AB, Williams SV, Frumkin H, Kondawar VK, Glick H, Ganju AK. Blood lead in children and its determinants in Nagpur, India. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2001; 7:119-26. [PMID: 11373042 DOI: 10.1179/107735201800339498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
In a community-based cross-sectional study of 297 children aged 6 months to 6 years in an Indian city, the authors assessed the prevalence of elevated (> or = 10 microg/dL) blood lead (PbB) levels, their risk factors, and the lead contents in potential environmental sources. Mean PbB was 18.4 microg/dL +/- 16.5. The prevalence of elevated PbB was 67%. Anticipated risk factors for elevated PbB were living in houses painted with lead-based paint, odds ratio (OR) 6.42 (1.75, 23.6; p = 0.005), recent exposures to lead-based paint, OR 2.61 (1.07, 6.66; p = 0.03), and the use of the eye cosmetic ma," OR 2.63 (1.24, 5.56; p = 0.01). Unanticipated results were effect of upper caste as a risk factor, OR (adjusted) 1.85 (95% CI = 0.96, 3.57; p = 0.06), and the lack of effect of traffic, parental occupational exposure, or nutritional status. Analysis of various environmental sources such as paint, pencils, crayons, and clay revealed high lead levels. These results demonstrate the existence of a major environmental health problem in Indian children, with risk factors that differ from those in other countries.
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Patel AB, Srivastava S, Phadke RS. Substance P (free acid) adopts different conformation than native peptide in DMSO, water and DPPC bilayers. J Biomol Struct Dyn 2001; 19:129-38. [PMID: 11565844 DOI: 10.1080/07391102.2001.10506726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The conformation of substance P (free acid) (SPOH) has been investigated in dimethylsulfoxide (DMSO), water and dipalmitoylphosphotidylcholine (DPPC) bilayers by two-dimensional NMR and restraint molecular dynamics simulations. The observed NOE patterns for SPOH in these media are very much different from each other. Molecular modeling of the conformation of SPOH by incorporating NOEs as distance restraints shows wide differences in its conformation in three media. The main structural features for SPOH in DMSO are y-bends at Pro4 and Phe7 along with a non-specific bend around Lys3-Pro4-Gln5-Gln6, which are stabilized by Lys3CO-->Gln5NH, Gln6CO-->Phe8NH hydrogen bonding. The more flexible conformation of SPOH in water is transformed to an ordered structure after incorporation in DPPC bilayers. The conformation of SPOH in DPPC bilayers is characterized by gamma-bends at Pro4, Gln6 and Phe7, which are stabilized by hydrogen bonding between Lys3CO-->Gln5NH, Gln5CO-->Phe7NH and Gln6CO-->Phe8NH, respectively. The absence of biological activity in SPOH has been attributed to the absence of any helix like structure at the central residues and absence of any interresidue interaction with C-terminal OH group, in DPPC bilayers, a feature shown to be an important prerequisite for SP and SP agonists to bind to the NKI tachykinin receptor.
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Patel AB, Renge RL. Langherhans cell histiocytosis in monozygotic twins. Indian Pediatr 2001; 38:788-91. [PMID: 11463969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Patel AB, Renge RL. Caudal regression syndrome. Indian Pediatr 2001; 38:98. [PMID: 11175945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Patel AB, Renge RL. Hypomelanosis of Ito. Indian Pediatr 2000; 37:1386. [PMID: 11119347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Abstract
Rheumatic chorea is the sole neurologic manifestation of rheumatic fever. It is a debilitating illness lasting for weeks to months. Drugs like diazepam, haloperidol, chlorpromazine take four to six weeks for functional improvement and can cause serious side effects. The authors investigated the role of Vitamin E in reducing rheumatic chorea. A case series of patients of rheumatic chorea were administered Vitamin E in the dose 50 IU daily for fifteen days. The various clinical signs of rheumatic chorea were scored with MAIMS score (Modified Abnormal Involuntary Movement Scale score) which is used for tardive dyskinesia. No other drug for abnormal movements was used. In all the 4 patients who received vitamin E, there was remarkable change by 7th day and almost complete functional improvement by 14th day. Vitamin E is safer than the conventional drugs used for chorea in children. It was found effective in this case series. Its role needs further evaluation by a double-blind randomized controlled trial.
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Patel AB, Srivastava S, Coutinho E, Phadke RS. Replacement of phe(8) in substance P by tyr (Tyr(8)-SP) alters the conformation of the peptide in DMSO, water, and lipid bilayers. Biopolymers 1999; 50:602-12. [PMID: 10508963 DOI: 10.1002/(sici)1097-0282(199911)50:6<602::aid-bip5>3.0.co;2-n] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The conformation of [Tyr(8)]SP (Y8SP) in dimethylsulfoxide (DMSO), water, and dipalmitoyl phosphatidylcholine (DPPC) bilayers has been investigated by two-dimensional nmr and molecular dynamics simulations. Molecular modeling of the conformation of Y8SP by incorporating nuclear Overhauser effects as distance restraints shows wide differences in its conformation in the three media. In DMSO, the main structural features are gamma-bends along with a nonspecific bend around Gln(6)-Phe(7)-Tyr(8). The random coil structure seen in water is transformed into a beta-turn around the segment Gln(5)-Gln(6)-Phe(7)-Tyr(8) when Y8SP is incorporated into DPPC bilayers. The lower biological activity of Y8SP compared to the native peptide (SP) has been attributed to the absence of any helix like structure at the central residues, a feature shown to be an important prerequisite for SP and SP agonists to bind to the neurokinin 1 tachykinin receptor.
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Patel AB, Srivastava S, Phadke RS, Govil G. Arginine acts as a protective and reversal agent against glycolytic inhibitors in spermatozoa. PHYSIOLOGICAL CHEMISTRY AND PHYSICS AND MEDICAL NMR 1999; 31:29-40. [PMID: 10535103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
It is known that the amino acid arginine stimulates sperm motility and glycolytic activity. We have earlier studied its efficacy as a stimulator of glycolysis in goat spermatozoa under anaerobic conditions. Here, we have assessed the influence of arginine in reversing the impairment caused by glycolytic inhibitors, iodoacetamide and iodoacetic acid. Glycolysis has been monitored by measuring the consumption of 13C labeled glucose and the amount of 13C labeled lactate produced under different experimental conditions, using 13C NMR. It is observed that both L- and D-arginine are able to prevent and reverse the inhibitory action of glycolytic inhibitors. The reversal effect of arginine gives rise to about eight times higher metabolic activity as compared to the inhibited cells while structurally related amino acids such as nitro-arginine, homo-arginine, lysine and ornithine are ineffective. The energetics of spermatozoa as measured by 31P NMR show a reduction in ATP level in cells incubated with iodoacetamide. Treatment of these cells with both L- and D-arginine restores the ATP level. The results may have significance in the treatment of male infertility.
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Patel AB, Srivastava S, Phadke RS. Interaction of 7-hydroxy-8-(phenylazo)1,3-naphthalenedisulfonate with bovine plasma albumin. Spectroscopic studies. J Biol Chem 1999; 274:21755-62. [PMID: 10419489 DOI: 10.1074/jbc.274.31.21755] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Interaction of Orange G (OG) with bovine plasma albumin (BPA) has been investigated using NMR, UV-visible absorption, CD, and fluorescence techniques. The bound conformation of OG is a compact structure with N9-N10 bond in a non-planar syn conformation. The binding causes a decrease in the 478-nm absorption band of OG. The analysis of the binding isotherm generated from UV-visible absorption measurements gives a dissociation constant of 10 microM and stoichiometry 1:1 for BPA.OG complex. Dissociation constant is invariant in the pH range 5.0-8.0 and is approximately 20 times higher at pH 4.0 than its value at pH 7.0. Near and far UV-CD studies indicate alterations in the helical content and in the tertiary structure of the protein on complexation. The binding induces (-) and (+) CD at 335 nm and 465 nm, respectively. The binding also results into an increase in the steady state fluorescence anisotropy of OG without affecting emission maximum and quantum yield. Fluorescence data indicate that quenching of Trp fluorescence by OG is static in nature and OG selectively binds near Trp-135. Observation of similar rotational correlation time for BPA and BPA.OG complex indicates that the overall globular structure of BPA remains unaltered on binding despite certain internal rearrangement in the protein structure.
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Patel AB, Srivastava S, Phadke RS, Govil G. Identification of low-molecular-weight compounds in goat epididymis using multinuclear nuclear magnetic resonance. Anal Biochem 1999; 266:205-15. [PMID: 9888977 DOI: 10.1006/abio.1998.2888] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Multinuclear nuclear magnetic resonance (NMR) (1H, 13C, and 31P) studies have been performed on aqueous solutions of lyophilysates of cell-free extract, epididymal fluid, and intact cells from caput and cauda regions of epididymis of sacrificed goats. Identification of low-molecular-weight compounds present in different maturation phases of spermatozoa has been carried out. Several low-molecular-weight compounds have been identified by assigning 600 MHz 1H NMR spectra with the help of two-dimensional homonuclear and heteronuclear correlation spectroscopy such as double quantum filtered correlation spectroscopy and heteronuclear single quantum correlation spectroscopy. Homonuclear coupling constants have also been used to get unambiguous assignments of resonances. NMR data were compared with those of standard samples measured at same pH and with those reported in the literature. Identification of several amino acids, carbohydrates, and lipids have been made and their presence has been discussed in relation to their relevance to sperm functions. The presence of beta-alanine and hypotaurine has been reported for the first time in goat epididymis.
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Patel AB, Srivastava S, Phadke RS, Govil G. Arginine activates glycolysis of goat epididymal spermatozoa: an NMR study. Biophys J 1998; 75:1522-8. [PMID: 9726954 PMCID: PMC1299827 DOI: 10.1016/s0006-3495(98)74071-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The present study explores the mechanism underlying the action of L-arginine on the metabolic activity of spermatozoa. Goat epididymal spermatozoa were incubated with different concentrations of L-arginine to determine its effect on the utilization of glucose, fructose, and pyruvate. NMR techniques have been applied to elucidate the effect of L-arginine, L-lysine, and L-ornithine on the glycolysis of epididymal goat spermatozoa. Whereas 31P NMR has been used to estimate the change of pH in the presence of different concentrations of L-arginine, 13C NMR has been used to estimate the substrate consumption and lactate production. At optimal concentration of L-arginine, the forward metabolic rates have been found to increase by two to three times over control experiments. Arginine is not consumed in these reactions, but acts as an activator. Longitudinal relaxation time (T1) measurements indicate that the guanidino group of L-arginine plays an active role in binding to cells. The amino acid L-lysine is less effective, and L-ornithine is ineffective.
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Patel AB, Pandya AA. Effects of chronic manganese toxicity on tissue levels and urinary excretion of nicotinamide nucleotides in rats. Hum Exp Toxicol 1994; 13:307-9. [PMID: 8043310 DOI: 10.1177/096032719401300503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Male rats were exposed to manganese sulphate i.p. daily for a period of four weeks to see its effects on tissue levels and urinary excretion of total nicotinamide nucleotides (TNN). Increased levels of TNN were observed in blood and brain while the levels were found to be decreased in liver. There was a progressive increase in the excretion of TNN during the experimental period. TNN levels in blood and urine might serve as useful biological indicators of Mn toxicity.
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