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Chatterjee S, Sunitha TA, Velayudhan A, Khanna S. An investigation into the psychobiology of social phobia: personality domains and serotonergic function. Acta Psychiatr Scand 1997; 95:544-50. [PMID: 9242851 DOI: 10.1111/j.1600-0447.1997.tb10144.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The aim of the present study was to explore a psychobiological perspective in the aetiology of social phobia. The emphasis was on serotonergic function and personality. A total of 20 social phobics according to ICD-10 DCR criteria were assessed with the Schedule for Clinical Assessment in Neuropsychiatry and the International Personality Disorder Examination. They were compared with an age-matched normal population with regard to scores on the Fear of Negative Evaluation Scale, the Social Avoidance and Distress Scale, the Temperament and Character Inventory, and platelet 5HT2 receptor function. Other Axis-I disorders and cluster C personality disorders were frequently encountered. The social phobia group was characterized by high levels of harm avoidance, and low levels of novelty seeking, co-operativeness and self-directedness. Platelet 5HT2 receptor density did not differentiate between the groups, but was associated with severity of social phobia. An integrated psychobiological model is presented.
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Yeo TT, Khanna S, Nowinski WL. Exploring the human brain using single-unit microelectrode technique during awake stereotactic functional neurosurgery. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1997; 26:350-5. [PMID: 9285031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In neuroscience research, the use of true single-unit microelectrode technique has been confined largely to the animal neurophysiology laboratory due to the complexity of the equipment required and the fastidious, time-consuming nature of the methodology. We report here our successful clinical use of this technique in human patients with Parkinson's disease undergoing awake stereotactic movement disorder neurosurgery. The common targets in such operations are the postero-ventral portion of the globus pallidus interna in the basal ganglia (for dopa-induced dyskinesias particularly) and the ventro-intermediate nucleus of the thalamus (for tremor-predominant Parkinson's disease). Accurate and exquisite neurophysiological localisation of these small targets deep within the brain can be obtained with single-unit microelectrode technique prior to the insertion of a deep brain stimulator or definitive neurosurgical radiofrequency lesioning in the target area. This accuracy translates into better outcomes for patients and a reduced incidence of complications. The wealth of data gained from studying the abnormal behaviour of neurons within the basal ganglia and thalamus also provides us with fundamental insights into the pathophysiology behind Parkinson's disease.
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Khanna S, Ravi V, Shenoy PK, Chandramuki A, Channabasavanna SM. Cerebrospinal fluid viral antibodies in obsessive-compulsive disorder in an Indian population. Biol Psychiatry 1997; 41:883-90. [PMID: 9099415 DOI: 10.1016/s0006-3223(96)00174-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Immunoglobulin G viral antibodies for herpes simplex virus type 1, varicella zoster virus, cytomegalovirus, measles, and mumps were studied in 76 subjects with obsessive-compulsive disorder and compared with a control population. There was a significantly higher titer for herpes simplex virus type 1 antibodies. Sera: cerebrospinal fluid ratios were suggestive of intrathecal synthesis.
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255
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Mittal SR, Khanna S, Mathur D. Isolated infarctions of the right ventricle. J Electrocardiol 1997; 30:157-8. [PMID: 9141613 DOI: 10.1016/s0022-0736(97)80026-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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256
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Khanna S. Dorsal hippocampus field CA1 pyramidal cell responses to a persistent versus an acute nociceptive stimulus and their septal modulation. Neuroscience 1997; 77:713-21. [PMID: 9070747 DOI: 10.1016/s0306-4522(96)00456-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In urethane anaesthetized rats subcutaneous formalin injection in the right hind paw, a model of persistent pain, produced (i) a prolonged increase in the period of field rhythmic sinusoidal (or theta) activity, (ii) a depression of dorsal hippocampal field CA1 pyramidal cell synaptic excitability (mean peak depression of population spike amplitude being 50 +/- 6%) observed to the 60th min post injection, and (iii) a persistent decrease in extracellular activity of the majority of CA1 pyramidal cells (15/20 or 75%) with only a small percentage excited (5/20 or 25%). In contrast an intense noxious heat stimulus applied briefly to the distal end of the tail evoked a short duration increase in period of theta activation and suppression of pyramidal cell responses. With this acute stimulus the proportion of CA1 pyramidal cells excited (8/16) were similar to that suppressed (7/16). Finally, electrolytic lesions centred in the medial septal vertical limb of diagonal band of Broca (or septal region) prevented a noxious stimulus-induced theta and depression of CA1 pyramidal cell responses. Rather, in such lesioned animals noxious stimulation excited the majority CA1 complex spike cells studied (8/10). The above data are consistent with the notion that septohippocampal inputs are involved in noxious stimulus-induced CA1 pyramidal cell suppression. The formalin injection-induced selective activation of CA1 complex spike cells against a background of widespread pyramidal cell suppression might produce a "signal to noise" contributory to nociceptive processing in limbic structures. Such a processing might be involved in the affective motivational component of pain.
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257
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Channabasavanna SM, Khanna S. Therapy with amineptine, a dopamine reuptake inhibitor, in patients with major depression. Indian J Psychiatry 1997; 39:147-53. [PMID: 21584062 PMCID: PMC2967100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The original tricyclic antidepressant drugs are consistently underused in major depression because of side effects, delayed onset of action, and potential for overdose. In an open study of 6 weeks' duration, we studied the efficacy and acceptability of amineptine, a dopamine reuptake inhibitor, at fixed dose of 200 mg per day in 50 patients with major depression.Intention-to-treat analysis showed a patient response rate of 64% (95% CI 77-50) in HDRS, 62% (95% CI 75-48) in MADRS, 46% (95% CI 59-32) in ZUNG scale, 52% (95% CI 66-38) in Social Activity scale, and 26% ("95% CI 38-14) in CGI-severity of illness after 7 days treatment. Response in CGI-global improvement was 38% (95% CI 51-25), and in CGI-efficacy index 48% (95% CI 62-34) after 14 days of treatment. With continued therapy, only CGI-severity of illness showed a significant increase in response rate after 42 days. The treatment effect of amineptine was reflected in a significant and progressive improvement in all depression, social activity, and CGI rating scale scores throughout the study period. Somatic symptoms and side effects assessed by AMDP-5 showed significant improvement at each assessment.The clinically useful response in depression which occurred by the first week of treatment, favourable side effect profile, and the convenience of a fixed dose could make amineptine a suitable first line alternative for the treatment of major depression.
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Kovacik MW, Singri P, Khanna S, Gradisar IA. Medical and financial aspects of same-day bilateral total knee arthroplasties. BIOMEDICAL SCIENCES INSTRUMENTATION 1997; 33:429-34. [PMID: 9731398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
In this retrospective study, we compared forty-five patients who had undergone same-day bilateral total knee arthroplasties with 144 patients who had undergone unilateral total knee arthroplasty procedures. All procedures were performed by a single surgeon using a single prosthetic design between June 1994 to May 1996. The issues studied were the length of hospital stay, hospital charges, units of blood transfused, units of homologous blood transfused, and the rate and type of complications. This study also examined the usage and financial charges of extended care facilities and/or home health care following discharge from the hospital. Results show that, for patients suffering from symptomatic bilateral knee disease, the same-day bilateral total knee procedure is significantly less costly than staged bilateral procedures. The rate and type of complications seen in the same-day bilateral cases were not significantly different from complications seen in unilateral cases.
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Mann A, Raven P, Khanna S, Channabasavanna S. Assessing Personality Disorders for Epidemiological Research. Eur Psychiatry 1997. [DOI: 10.1016/s0924-9338(97)80489-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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260
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Lal B, Khanna S. Degradation of crude oil by Acinetobacter calcoaceticus and Alcaligenes odorans. J Appl Microbiol 1996. [DOI: 10.1111/j.1365-2672.1996.tb01926.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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261
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Lal B, Khanna S. Degradation of crude oil by Acinetobacter calcoaceticus and Alcaligenes odorans. THE JOURNAL OF APPLIED BACTERIOLOGY 1996; 81:355-62. [PMID: 8896350 DOI: 10.1111/j.1365-2672.1996.tb03519.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Two types of Indian crude oil (Bombay High and Gujarat) were tested for their biodegradability by Acinetobacter calcoaceticus and Alcaligenes odorans. Acinetobacter calcoaceticus S30 and Alc. odorans P20 degraded Bombay High crude oil by 50% and 45%, while only 29% and 37% of Gujarat crude oil (heavy crude oil) was degraded by these isolates, respectively. Acinetobacter calcoaceticus and Alc. odorans in combination degraded 58% and 40% of Bombay High and Gujarat crude oils, respectively, which were significantly higher than that of by individual cultures. Acinetobacter calcoaceticus S30 degraded more of the alkanes fraction than the aromatics fraction of both crude oils. GC fingerprinting of alkane fraction showed major degradation of heptadecane (C17), octadecane (C18), nonadecane (C19), eicosane (C20), docosane (C22), tricosane (C23) and tetracosane (C24) of crude oil, while the Alc. odorans P20 degraded alkanes and aromatics equally. The asphaltenic component increased in both types of crude oil after biodegradation . The two strains grew very well on n-alkane up to C33 as well as on pristane (branched-chain alkane) but could not grow on cycloalkanes. Acinetobacter calcoaceticus S30 could not grow on pure polycyclic aromatic hydrocarbon (PAH) compounds except naphthalene but Alc. odorans P20 could grow on anthracene, phenanthrene, dibenzothiophene, fluorene, fluoranthene, pyrene and chrysene.
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262
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Harish MG, Suresh KP, Rajan I, Reddy YC, Khanna S. Phenomenological study of late-onset schizophrenia. Indian J Psychiatry 1996; 38:231-5. [PMID: 21584136 PMCID: PMC2970876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The phenomenological presentation of late-onset schizophrenia is a topic of considerable debate. This study aims to look at the clinical presentation of late-onset schizophrenia. Charts of all subjects who received a diagnosis of schizophrenia between January 1990 and December 1993 with age of onset being 45 or more were systematically analysed using the OPCRIT checklist. Of the 89 subjects chosen for analysis, 59 satisfied the ICD-10 DCR criteria for schizophrenia and formed the sample of the study. Of them, 20 were males and 39 were females. The mean age of onset for males was 51.6±5.7 years and for females, 53.2±16.7 years. The commonest phenomenon was persecutory delusion (83%) followed by delusion of influence and hallucinations in any modality (66%each). 53% of the subjects had third person auditory hallucinations, while 42% showed negative symptoms. Delusional perception and thought echo were not found in any subject. The implications of these phenomenological findings are discussed.
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Abstract
OBJECTIVE There are reports of alprazolam-induced hypomania/mania. Here is a case report of a patient who developed hypomania during treatment with alprazolam, but not with diazepam, another benzodiazepine derivative. CLINICAL PICTURE The illness was of 2 months' duration and the patient received a diagnosis of anxious depression. Following treatment with alprazolam, the patient developed hypomania characterised by euphoria, overactivity, overtalkactivity, racing thoughts, oversocialisation, enhanced self-confidence and disturbed sleep. TREATMENT Hypomania subsided when alprazolam was withdrawn. There was no recurrence with fluoxetine or diazepam that ameliorated the primary condition. OUTCOME The patient was symptom-free on follow-up. CONCLUSIONS Alprazolam can induce hypomania/mania and, perhaps, it differs from other benzodiazepines in its mode of action. Clinicians have to be alert to the possibility of their patients developing hypomania/mania while on alprazolam.
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264
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Buller KM, Khanna S, Sibbald JR, Day TA. Central noradrenergic neurons signal via ATP to elicit vasopressin responses to haemorrhage. Neuroscience 1996; 73:637-42. [PMID: 8809784 DOI: 10.1016/0306-4522(96)00156-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
It is now clear that ATP acts as a neurotransmitter in both the peripheral and central nervous systems. In the periphery, purinergic transmission has been best studied at certain sympathetic neuroeffector junctions where ATP, co-localized with noradrenaline, is used to elicit the primary post-junctional response. More recently, several groups have raised the possibility that central catecholaminergic neurons might use ATP in a similar fashion. Accordingly, we now present findings from immediate early gene expression and electrophysiological studies which indicate that ATP, acting through P2 purinoreceptors, is used as a transmitter by caudal brainstem noradrenergic neurons, the A1 group, in their interaction with vasopressinergic neurosecretory cells. Supraoptic nucleus vasopressin cell responses to moderate haemorrhage, known to be generated by the A1 projection, were suppressed by hypothalamic application of the P2 receptor antagonist suramin. However, suramin did not alter vasopressin cell responses to osmotic challenge or severely hypotensive haemorrhage, two stimuli known to excite vasopressin cells independently of the A1 projection. These data are consistent with an identity of action between the A1 input to vasopressin cells and the activation of ATP receptors on vasopressin cells. The use of ATP as a transmitter by other catecholamine neurons in the brain awaits further confirmation, but the present findings suggest that in certain instances the therapeutic manipulation of central catecholamine neuron output might best be achieved with pharmacological agents which target purinergic rather than adrenergic transmission.
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265
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Pathak KA, Khanna R, Khanna HD, Khanna S, Gupta S, Khanna NN. Carcinoembryonic antigen: an invaluable marker for advanced breast cancer. J Postgrad Med 1996; 42:68-71. [PMID: 9715319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Serial serum Carcinoembryonic antigen (CEA) levels were measured in 150 individuals (50 patients with breast cancer, 50 benign breast diseases and 50 other controls). These levels were correlated with clinicopathological parameters and follow-up information. Serum CEA levels were independent of the primary tumor status, their histology, lymphoreticular response and the patients' characteristics as well as the age, sex and the menstrual status. However, the nodal status, number of involved nodes and the grade of the tumors had significant influence on the level of serum CEA. Breast cancer patients especially those with metastasis had significantly higher serum CEA levels as compared to the controls and those with localised disease, irrespective of the site of metastasis. These levels were lowered appreciably by the disease regression and were raised or stable during the disease progression. Receiver operating characteristic (ROC) curve showed metastasis to be more frequent in patients with pretreatment serum CEA levels above 25 ng/ml and persistent post treatment CEA levels above 15 ng/ml. Serum CEA level was found to be a valuable prognostic indicator for advanced breast cancer and serial serum CEA levels provided an average lead time of about 3.9 months before the clinical appearance of metastasis.
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266
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Mittal SR, Khanna S, Jain S. Failure of electrocardiograph to diagnose right ventricular infarction in the presence of left ventricular infero-posterior infarction. Indian Heart J 1996; 48:285-6. [PMID: 8755019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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267
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Khanna HD, Singh S, Agrawal G, Khanna R, Singh LP, Khanna R, Khanna S. Intra nuclear estrogen receptor status and its clinicopathological correlation in breast cancer patients. CANCER BIOCHEMISTRY BIOPHYSICS 1996; 15:141-9. [PMID: 8937738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Intranuclear estrogen receptor (ERn) content of breast cancer tissue is thought to be more closely related to prognosis, and response to hormone treatment, as compared to conventional cytosolic estrogen receptor (REc). ERn and ERc levels in primary breast carcinoma tissue were assayed by ER-Enzyme immuno assay (ER-EIA), and the correlation of ERn with ERc and clinico-pathological parameters were assessed. ERn concentration and positive status, with 15 fmol as the cut-off value for positivity, is related to increasing age, lesser parity, post-menopausal status and smaller tumor size. A significant correlation exists between ERn and lesser metastatic axillary nodes and the early TNM stage. ERn was found to be correlated to better tumor differentiation, absent or slight L-R response and tumor necrosis.
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268
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Sikri VK, Sikri P, Singh J, Manjri M, Khanna S. Resinifying therapy in endodontics. II--Histological and bacteriological evaluation. Indian J Dent Res 1996; 7:51-3. [PMID: 9495099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
This study was conducted on six rabbits, six rats and six human permanent teeth to evaluate histologically the effect of resin resorcinol in the periapical areas, the bacteriological aspect of the resin and the penetration of resin in the dentinal tubules. After 12 days period of observation plenty of lymphocytes and macrophages were evident along with granulomas which are suggestive of the tendency of the resin to stay longer. It was observed that the resin penetrate approximately three fourth distance inside the dentinal tubules. In the last phase the resin was found to be effective against the eight commonly found micro organisms. Though the histological results indicated that the periapical tissue would take longer time for complete repair, yet clinically the tooth functions well. Resinifying therapy is effective and economical method in root canal treatment.
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269
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Abbas S, Khanna S, Taly AB. Obsessive-compulsive disorder and rheumatic chorea: is there a connection? Psychopathology 1996; 29:193-7. [PMID: 8817740 DOI: 10.1159/000284991] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
There is increasing evidence to suggest basal ganglion involvement in the aetiopathogenesis of obsessive-compulsive disorder (OCD). Twenty subjects with rheumatic chorea were assessed for presence of OCD and evaluated on Leyton's Obsessional Inventory. Four subjects had OCD. The study group had markedly higher scores on all the scales of Leyton's Obsessional Inventory. The findings implicate that caudate dysfunction is not sufficient on its own to explain the presence of obsessive-compulsive behaviour and that additional basal ganglion regions/rostral connections also have to be involved to produce co-morbidity.
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270
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Sidhu BS, Kumra RK, Khanna S, Maini VK. Congenital diaphragmatic hernia of Bochdalek--delayed presentation. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 1995; 93:428-9, 432. [PMID: 8775925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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271
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Smith DW, Sibbald JR, Khanna S, Day TA. Rat vasopressin cell responses to simulated hemorrhage: stimulus-dependent role for A1 noradrenergic neurons. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:R1336-42. [PMID: 7771599 DOI: 10.1152/ajpregu.1995.268.5.r1336] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
c-fos expression mapping and electrophysiological recording experiments were done to clarify the role of the A1 noradrenergic cell group in the vasopressin response to hypotensive hemorrhage. In pentobarbital-anesthetized rats, moderate and severe hypotensive hemorrhages were simulated by brief occlusion of the inferior vena cava sufficient to reduce mean arterial pressure to approximately 50 or 30 mmHg, respectively. Both stimuli significantly increased the number of A1 region catecholamine cells displaying Fos-like immunoreactivity, this effect being most prominent at the level of the area postrema. Both stimuli also increased the number of supraoptic nucleus vasopressin cells displaying Fos-like immunoreactivity. Accordingly, electrophysiological studies involving separate animals confirmed that both moderate and severe caval occlusion significantly increased the firing of functionally identified vasopressin cells recorded in the supraoptic nucleus. However, although interruption of A1 region neuronal function by injection of gamma-aminobutyric acid at the level of the area postrema eliminated the increase in vasopressin cell firing elicited by moderate caval occlusion, it did not block the response to severe caval occlusion. These findings suggest that, in the rat, the vasopressin response to an acute reduction in central blood volume, such as that produced by hemorrhage, depends on the A1 projection only if the stimulus is of moderate intensity. Severe stimuli appear to involve activation of both the A1 projection and an additional vasopressin-stimulatory pathway that bypasses the A1 region.
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272
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Singh V, Jain AK, Agrawal AK, Gupta S, Khanna S, Khanna AK, Gupta JP. Clinicopathological profile of abdominal tuberculosis. THE BRITISH JOURNAL OF CLINICAL PRACTICE 1995; 49:22-4. [PMID: 7742178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The clinical and histopathological profile is presented of 145 patients with abdominal tuberculosis studied prospectively over a period of 5 years. The study highlights the role of various investigations and therapeutic response in this condition.
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273
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Jindal K, Chaudhary R, Gangwal S, Singla A, Khanna S. High-performance thin-layer chromatographic method for monitoring degradation products of rifampicin in drug excipient interaction studies. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)00730-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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274
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Subramoniam A, Khandelwal S, Dwivedi PD, Khanna S, Shanker R. Dibutyltin dilaurate induced thymic atrophy and modulation of phosphoinositide pathway of cell signalling in thymocytes of rats. Immunopharmacol Immunotoxicol 1994; 16:645-77. [PMID: 7876466 DOI: 10.3109/08923979409019744] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A marked dose dependent reduction in thymus weight and its nucleated cell counts with histological alterations was observed in rats exposed to oral dibutyltin dilaurate (DBTL) for 2 weeks at 2, 4, 8 or 16 mg/kg body weight. The incorporation of [3H]-inositol into all the three major phosphoinositides was drastically reduced in thymocytes in a dose dependent manner. Furthermore, the basal and the mitogen (Con A) stimulated [3H]-inositol phosphates generation was diminished significantly in 8 mg DBTL group. However, in vitro incubation of DBTL with thymocytes failed to evoke any change in phosphoinositide hydrolysis. Similarly, a time and dose dependent inhibition in phosphoinositide synthesis with as high as 80% by 10 microM DBTL was exhibited under in vitro conditions. A 130% and 600% enhancement of protein kinase C (PKC) activity in thymocytes was seen in 4 mg and 8 mg DBTL group, respectively. Addition of DBTL to the cell free assay system of thymocytes resulted in a concentration dependent activation of the enzyme activity. A dose dependent increase in intracellular calcium was also evident when DBTL was added to thymocytes under in vitro conditions. These results are of significance and may bear close relationship to the observed thymic atrophy by DBTL.
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275
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Saraf SK, Kumar A, Tuli SM, Khanna S. Effect of size and shape of the allogeneic bone grafts in bridging experimental ulnar gap in rabbits. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1994; 32:690-3. [PMID: 7821978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Partially decalcified allogeneic bone matrix was cut into the sizes and shapes of cylinders, bone strips and pulverized bone powder. Large osteoperiosteal gaps were created in rabbit's ulnae. A total of 14 gaps were filled with bone strips, 20 with powder, six with cylinders and two were left unbridged to serve as control. The healing of gap was assessed at intervals with a maximum follow up of 24 weeks. Clinically at 12 weeks the bone strips could not be moved separately from each other, the whole tubular bone had also united whereas gaps filled with bone powder did not diminish in size. Radiologically union occurred earlier (around 12 weeks) in bone strips as compared to cylinders (approx-18 weeks). With bone powder only a faint line of the remnants was visible. Gross examination findings of the grafted area were in concurrence with the clinical and radiological findings. Overall the gaps filled with bone strips had 100 per cent success with early osteo induction and remodelling as compared to long cylinders whereas gaps filled with bone powder had complete failure.
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