401
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Mehta M, Bagga A, Pande P, Bajaj G, Srivastava RN. Behavior problems in nephrotic syndrome. Indian Pediatr 1995; 32:1281-6. [PMID: 8772885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To evaluate the adaptive competences and behavioral problems in children with nephrotic syndrome, and whether their mothers also showed features of psychosocial stress. DESIGN Prospective case-control study. SETTING Pediatric Out-Patient Department. SUBJECTS Seventy consecutive patients of nephrotic syndrome, between the ages of 4 to 14 years, and their mothers constituted cases. The control group, matched for age, sex and socioeconomic status comprised of 46 children and their mothers. The mother's description of the child's behavior, on the Child Behavior Checklist (CBCL), was obtained to assess behavioral problems and social competences. The level of anxiety in the mother was assessed using the PGI Health Questionnaire N2. RESULTS Children with nephrotic syndrome showed features of depressed, hyperactive or aggressive behavior. Somatic complaints, social withdrawal and poor school performance were also observed. These problems did not interfere with compliance to treatment and only 7 patients required psychological interventions. Boys with nephrotic syndrome had more hyperactive and aggressive behavior as compared to girls. The scores on the CBCL were well correlated with the anxiety scores of the mother. CONCLUSIONS These observations suggest the presence of minor behavior problems in a significant proportion of children with nephrotic syndrome. The severity of these problems may be related to the attitude of the mother towards the child's illness.
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402
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Sharan P, Mehta M, Choudhry VP. Coping and adaptation in parents of children suffering from acute lymphoblastic leukemia. Indian J Pediatr 1995; 62:737-41. [PMID: 10829953 DOI: 10.1007/bf02825131] [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: 11/29/2022]
Abstract
The coping and adaptation of 30 parents of children suffering from A.L.L. (during first remission), was studied with the Thematic Apperception Test (TAT--Indian modification). Emotional distress was evident in the stories of 83%, only 37% maintained an expectation of a positive outcome. Parents' psychiatric morbidity was found to be associated with the gender of the parent, employment status, and on the TAT--with the expectation of an unfavourable outcome, feelings of lack of self efficacy and emotional distress. Particularly depression. A significant association between the presence of psychiatric disturbance in the children and the parents was also found.
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403
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Sahakian BJ, Elliott R, Low N, Mehta M, Clark RT, Pozniak AL. Neuropsychological deficits in tests of executive function in asymptomatic and symptomatic HIV-1 seropositive men. Psychol Med 1995; 25:1233-1246. [PMID: 8637953 DOI: 10.1017/s0033291700033201] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
There has been much debate about the exact nature and time of onset of the cognitive impairments associated with infection by the human immunodeficiency virus type 1 (HIV-1). Studies to date have not reached consistent conclusions. The present study comprised 22 asymptomatic and 18 symptomatic HIV-1 seropositive men, whose only risk factor for contraction of the virus was sexual intercourse, and 18 seronegative controls matched for age and IQ. Subjects were given computerized neuropsychological tests from the CANTAB battery, which assessed visuospatial memory, attention and executive function. Both the asymptomatic and the symptomatic HIV-1 seropositive subjects showed a selective pattern of deficits relative to the controls. In addition, the seropositive subjects were subtly but significantly impaired on tests of executive function but unimpaired on certain tests of visual memory. This finding supports an hypothesis that frontostriatal dysfunction occurs in HIV-1 infected individuals prior even to the expression of clinical symptoms.
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404
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Schiller J, Larson M, Larson M, Pharo L, Mehta M, Storer B. 1106 Amifostine (A), cisplatin (C), Vinblastine (V): A highly active regimen for non small cell lung cancer (NSCLC). Eur J Cancer 1995. [DOI: 10.1016/0959-8049(95)96352-e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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405
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Mehta M, Schiller JH. Prognosis with asymptomatic pulmonary nodules. JAMA 1995; 274:358. [PMID: 7609270 DOI: 10.1001/jama.274.4.358b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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406
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Abstract
The coping and adaptation of 39 children (6-12 years) to Acute Lymphoblastic Leukemia was studied during the first remission with a projective technique--Children's Apperception Test (CAT-S). Seventy seven percent of the children gave adequate responses. Among these, disease awareness was present in 96%, expectation of a favourable outcome was held by 70%, though 61% evidenced emotional distress. Children's psychiatric morbidity was found to be associated with non-response to CAT-S, to anxiety related themes, and negatively with ability to maintain an expectation of a positive outcome.
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407
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Mehta M, Wolff G, Young ML, Mas MS, Escobar A, Gelband H. Usefulness of endothelin-1 as a predictor of response to head-up tilt-table testing in children with syncope. Am J Cardiol 1995; 76:86-8. [PMID: 7793414 DOI: 10.1016/s0002-9149(99)80810-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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408
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Zhou HH, Norman P, DeLima LG, Mehta M, Bass D. The minimum alveolar concentration of isoflurane in patients undergoing bilateral tubal ligation in the postpartum period. Anesthesiology 1995; 82:1364-8. [PMID: 7793650 DOI: 10.1097/00000542-199506000-00007] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND The minimum alveolar concentration (MAC) of volatile anesthetics is decreased during pregnancy, but MAC in the early postpartum period has not been reported. The aim of this study was to determine the MAC of isoflurane and to evaluate the relation between MAC and serum progesterone and beta-endorphin in patients after delivery. METHODS Eight patients undergoing elective bilateral tubal ligation during general anesthesia in the early postpartum period (< 12 h postpartum) and eight patients undergoing this procedure in the late postpartum period (12-25 h postpartum) were studied. Eight patients undergoing bilateral tubal ligation more than 6 weeks after delivery served as control subjects. Anesthesia was induced with propofol and maintained with isoflurane in oxygen to a steady end-tidal concentration of 0.8-1.0 vol% for 10 min. Reaction to a standardized electric stimulation applied to the forearm was graded as positive (gross or delayed movement) or negative. By using the bracketing technique, the concentration of isoflurane was increased or decreased by 0.1 vol%, depending on the positive or negative responses. RESULTS The MAC (mean +/- SD) in patients in the early postpartum period was significantly less (0.75 +/- 0.17 vol%) than that in control subjects (1.04 +/- 0.12 vol%; P < 0.01) and that in patients in the late postpartum period (0.95 +/- 0.2 vol%; P < 0.05). The difference in MAC values between late postpartum and control was not significant (P > 0.05). There was an inverse correlation between progesterone concentration postpartum and time after delivery (r = -0.527; P = 0.036), but P = 0.744). There was no correlation between plasma progesterone or beta-endorphin and MAC by multiple regression (r = 0.166; P = 0.950). CONCLUSIONS Isoflurane MAC remains 28% less than normal within the 1st 12 h postpartum and then returns to normal 12-25 h after delivery.
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409
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Kumar CM, Mehta M. Ankylosing spondylitis: lateral approach to spinal anaesthesia for lower limb surgery. Can J Anaesth 1995; 42:73-6. [PMID: 7889588 DOI: 10.1007/bf03010575] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We describe three patients with long-standing ankyolsing spondylitis (AS) who underwent lower limb joint surgery under spinal anaesthesia. At preoperative assessment, it was considered that intubation of the trachea was likely to be difficult or impossible and previous general anaesthesia was associated with increased morbidity. Midline approach spinal anaesthesia failed but the lateral approach was successful. Spinal anaesthesia was induced using a 24 gauge Sprotte (Pajunk) needle with 3.5 ml heavy bupivacaine 0.5% at the L3-4 interspace with the patients in the sitting position. This resulted in adequate sensory blockade for the surgical procedure. None of the patients required airway interventions but equipment and aids to secure airway were available.
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410
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Dutta EK, Tripathi BM, Lal R, Mehta M. Family response to paranoid and non-paranoid schizophrenic patients. Int J Rehabil Res 1995; 18:60-3. [PMID: 7797322 DOI: 10.1097/00004356-199501000-00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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411
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412
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Singh I, Mehta M, Singh J, Yadav J. Nasal mucus clearance in chronic smokers. THE INDIAN JOURNAL OF CHEST DISEASES & ALLIED SCIENCES 1994; 36:133-6. [PMID: 7737700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Smokers were observed to have grossly prolonged nasal mucus clearance. It was also inferred that the persons smoking bidi/unfiltered cigarettes had significant depression of ciliary activity. The clearance was prolonged as the number of cigarettes smoked and the duration of smoking increased. It was greater among those who gave a history of nasal exhalation of inhaled smoke. Nasal mucociliary clearance measurement is easy to measure and can be a useful index in evaluating the effect of smoking on the ciliary activity of the mucosa of the respiratory tract.
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413
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Mehta M. Student learning. Indian J Pediatr 1994; 61:121-5. [PMID: 7927608 DOI: 10.1007/bf02843599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This paper reviews important practical aspects of student learning. Some student learn by memorizing important parts of the text by dividing the content into bits and pieces. In this approach, the surface approach, they may not be able to derive full meaning of the content. The other method used by the students is deep approach, wherein a student tries to understand the meaning of the materials. In medical education, it is important for the student to relate contents of study material to other ideas, and to map-put subject areas. In the present context, a medical student also needs to become an autonomous learner, for which a student needs to develop certain skills. Teachers have a significant role in providing opportunities to the students to learn actively and meaningfully. Learning outcome is related to characteristics of the student, the teachers, the institution, the learning styles and processing of the learned subject.
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414
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Rangraj MS, Mehta M, Zale G, Maffucci L, Herz B. Laparoscopic gastrojejunostomy: a case presentation. JOURNAL OF LAPAROENDOSCOPIC SURGERY 1994; 4:81-7. [PMID: 8173119 DOI: 10.1089/lps.1994.4.81] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Laparoscopic gastrojejunostomy is demonstrated as an alternative to open gastric bypass procedures. We performed the operative procedure safely and with reasonable anesthesia time, using stapling devices. It is hoped that further patient benefit will be obtained from this laparoscopic procedure in the future.
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415
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Larson DA, Bova F, Eisert D, Kline R, Loeffler J, Lutz W, Mehta M, Palta J, Schewe K, Schultz C. Current radiosurgery practice: results of an ASTRO survey. Task Force on Stereotactic Radiosurgery, American Society for Therapeutic Radiology and Oncology. Int J Radiat Oncol Biol Phys 1994; 28:523-6. [PMID: 8276670 DOI: 10.1016/0360-3016(94)90080-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE Although there is increasing interest in radiosurgery, little quantitative data regarding current patterns of radiosurgery practice are available. We developed a radiosurgery questionnaire to obtain information on radiosurgery practice. METHODS AND MATERIALS We distributed the questionnaire to the entire membership of the American Society of Therapeutic Radiology and Oncology in early 1993. Responses were obtained from 74 facilities that practice radiosurgery, corresponding to over 6000 treatments carried out since 1983 by 135 radiation oncologists and 130 physicists. RESULTS Most respondents were found to work within a multidisciplinary team, consisting of the following specialists (average hours devoted per patient on day of treatment in parentheses): radiation oncologist (3.8), neurosurgeon (3.2), physicist (6.1), radiologist (0.7), nurse (2.7), other (3.0). On average, neurosurgeons and nurses who perform Gamma Knife radiosurgery devote significantly more time-per-patient on the day of treatment than their peers who perform linac radiosurgery. On average, less experienced radiation oncologists and physicists (< or = 24 months experience, or < or = 50 patients treated) devote significantly more time-per-patient on the day of treatment than their more experienced peers. Although there are many more linac radiosurgery facilities than Gamma Knife facilities, on average the number of patients treated per month per facility is significantly larger at the latter. On average, follow-up responsibilities are nearly equally shared by radiation oncologists and neurosurgeons, except at Gamma Knife facilities, where neurosurgeons assume a larger percentage of follow-up responsibility. The percentages of patients treated at linac facilities for metastases or primary CNS malignancy are larger than the corresponding percentages at Gamma Knife facilities; the opposite is true for arteriovenous malformation, acoustic neuroma, and meningioma. CONCLUSION Current radiosurgery practice usually involves a team approach, with participation of specialists from radiation oncology, neurosurgery, physics, radiology, and nursing. The average number of M.D. and Ph.D. hours required per treatment on the day of radiosurgery is high.
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416
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Abstract
Mechanical back pain is a common disability often associated with the facet joint syndrome. Treatment is based on early, adequate pain relief with simple techniques of regional analgesia. In a few cases this is not enough and more sophisticated methods, such as radiofrequency denervation, cryo-analgesia and possibly intrathecal midazolam, are necessary. However, the main thrust of our approach is to treat the underlying structural disorder with strengthening of the back muscles and correction of postural abnormalities responsible for the mechanical back pain. Our report is based on an analysis of 83 patients who failed to respond to long periods of rest, suitable analgesic and allied drugs and other non-invasive measures. There had been no overriding indication for major surgery. A large number of these patients have been improved by our methods, but further work is in progress to extend the proportion of satisfactory results.
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417
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Jain Y, Choudhry VP, Arya LS, Mehta M. Neuropsychological abnormalities following CNS prophylaxis in children with acute lymphatic leukemia. Indian J Pediatr 1993; 60:675-81. [PMID: 8157338 DOI: 10.1007/bf02821732] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The pattern and prevalence of neuropsychological abnormalities in children receiving combination CNS prophylaxis (2000 rads cranial irradiation and intrathecal methotrexate) during therapy for acute lymphoblastic leukemia (ALL) were studied. Thirty five children (25 boys) in the age group 5-15 years (mean 9.3) with no evidence of CNS leukemia were included and 20 age matched normal siblings served as controls. Neuropsychological parameters of general intelligence (Malin's modification of WISC test); attention and concentration (colour cancellation test); memory (modified PGI memory test) and visuomotor perception (Bender Gestalt test) were evaluated at least 6 months after CNS prophylaxis. Six (17.1%) patients had mean intelligence quotients (IQ) less than 85, while all controls had IQ > 85 (p < 0.05). The mean IQ of the patient population (93.4 +/- 11.9) was significantly lower than the control group (107 +/- 8.4) (p < 0.001). Scores on the colour cancellation test were lower in the patients as compared to controls (148.7 +/- 27.7 versus 184.9 +/- 23.9; p < 0.01). The mean memory quotient in the patient population was also lower than in controls (74.5 +/- 12 versus 93.6 +/- 9.2; p < 0.001). Scores on the Bender-Gestalt test did not show a significant difference. The presence of significant neuropsychological abnormalities in patients of ALL indicates the need for modification of the schedule of CNS prophylaxis. A comprehensive psychometric evaluation at regular intervals is essential for longterm rehabilitation.
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418
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Qian M, Swagler AR, Mehta M, Vishwanathan C, Gallo JM. Pharmacokinetic Evaluation of anti-HIV Drug Interactions: Effect of Zidovudine on 2′-3′-Dideoxyinosine Kinetics in Monkeys. Antivir Chem Chemother 1993. [DOI: 10.1177/095632029300400304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The current investigation was conducted to determine if zidovudine (AZT) altered the pharmacokinetics of dideoxyinosine (ddl) in non-hurnan primates, an appropriate animal model for AZT and ddl pharmacokinetics in human. Each of nine animals received 20 mg kg−1of ddl intravenously in the absence and presence of two different dosage regimens of AZT. For each combination regimen, AZT was administered as a combined i.v. bolus-constant rate infusion regimen for 30 min that produced AZT plasma concentrations of about 4 μg ml−1in six animals (low dose group) and 11 μg ml−1in three others (high dose group). Serial blood samples were collected, and pharmacokinetic parameters for ddl were calculated based on plasma ddl concentrations measured by HPLC techniques.The pharmacokinetics of ddl given alone in the first phase of the low ( n = 6) and high ( n = 6) dose AZT groups, resulted in a mean elimination half-life 1.54 and 1.9h, a mean total clearance of 0.62 and 0.731 h−1kg−1, and a mean steady state volume of distribution of 1.02 and 0.891 kg−1, respectively. Following combined ddl and AZT administrations, in both the low and high dose AZT groups, plasma concentration-time profiles of ddl were similar for each monkey, and no statistical differences were observed in the pharmacokinetic parameters compared to those obtained when ddl was given alone. The fact that AZT does not alter the pharmacokinetics of ddl at the range of AZT dose studied provides a basis for rational dosage design for combined ddl and AZT treatments in HIV infection.
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419
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Petereit D, Mehta M, Turski P, Levin A, Strother C, Mistretta C, Mackie R, Gehring M, Kubsad S, Kinsella T. Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database. Int J Radiat Oncol Biol Phys 1993; 25:309-13. [PMID: 8420879 DOI: 10.1016/0360-3016(93)90353-w] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography and compared with stereotactic angiography. The goals were to establish the feasibility of magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquantify flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60, and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none (arteriovenous malformation obliterated). In 19 of 21 (90.5%) arteriovenous malformations, magnetic resonance angiography was equal or superior to stereotactic angiography for flow quantification and visualization of the nidus. Only 2 of 21 arteriovenous malformations were better demonstrated by stereotactic angiography than by magnetic resonance angiography (failure rate of 9.5%). The nidus size in one case was clearly underestimated by stereotactic angiography and would have resulted in a geographic miss without magnetic resonance angiography. Seven post-radiosurgery arteriovenous malformations were evaluated for follow-up with both magnetic resonance angiography and stereotactic angiography. In 6 of 7 arteriovenous malformations, magnetic resonance angiography response matched stereotactic angiography response. Correlation of flow with outcome was carried out for 14 arteriovenous malformations using magnetic resonance angiography only. Interestingly, all nine arteriovenous malformations with intermediate or slow flow demonstrated partial or complete obliteration; whereas only 3 of 5 fast flow arteriovenous malformations achieved a response with a median follow-up of 10 months. This early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery and flow parameters could be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning.(ABSTRACT TRUNCATED AT 400 WORDS)
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420
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Gallo JM, Swagler AR, Mehta M, Qian M. Pharmacokinetic evaluation of drug interactions with anti-human immunodeficiency virus drugs. VI. Effect of the calcium channel blocker nimodipine on zidovudine kinetics in monkeys. J Pharmacol Exp Ther 1993; 264:315-20. [PMID: 8423534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Coadministration of zidovudine (AZT) and nimodipine, a calcium-channel blocker, is a potential therapeutic regimen in acquired immunodeficiency syndrome patients based on the report that nimodipine can prevent human immunodeficiency virus-induced neurotoxicity in vitro. An evaluation of the pharmacokinetics of AZT and its glucuronide metabolite 3'-azido-3'-deoxy-5'-O-beta-D-glucopyranurosylthymidine (GAZT) in the presence and absence of nimodipine in monkeys was undertaken. After 20 mg/kg of AZT given i.v. in the presence and absence of nimodipine, nimodipine caused a significant reduction (41%) in the volume of distribution of AZT at steady state and a 22% decrease in total clearance. The disposition of GAZT was also influenced by nimodipine, causing a large increase in its area under the plasma concentration-time curve. Renal excretion data for AZT and GAZT, although inconclusive, suggested nimodipine caused a decrease in the renal clearance of AZT with a minimal change in the renal clearance of GAZT. The combined effects of nimodipine on the clearance of AZT and volume of distribution at steady state produced no change in its elimination half-life.
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421
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Felmingham D, Robbins M, Ghosh G, Mehta M, Leakey A, Clark S, Mumtaz G, Ridgway G, Gruneberg R. Comparative In Vitro Activity of PD 131628, the Microbiologically Active Constituent of the Prodrug CI-990 (PD 131112). Drugs 1993. [DOI: 10.2165/00003495-199300453-00045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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422
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Mehta M, Masciopinto J, Bastin K, Levin A, Chappell R, Miles J, Kinsella T. Glioblastoma treated with external beam radiotherapy and stereotactic radiosurgery boost. Int J Radiat Oncol Biol Phys 1993. [DOI: 10.1016/0360-3016(93)90670-q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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423
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Stafford RG, Mehta M, Kemppainen BW. Comparison of the partition coefficient and skin penetration of a marine algal toxin (lyngbyatoxin A). Food Chem Toxicol 1992; 30:795-801. [PMID: 1427518 DOI: 10.1016/0278-6915(92)90082-v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lyngbyatoxin A is produced by marine algae, and causes local cutaneous toxicity in swimmers. The purpose of this research was (1) to determine the partition coefficient of lyngbyatoxin A in octanol/water and (2) to use methods in vitro to measure the penetration and distribution of lyngbyatoxin A in guinea pig and human skin. Discs of excised guinea pig and human skin were mounted in diffusion chambers that exposed the epidermal surface to air and bathed the dermis with HEPES-buffered Hanks' balanced salt solution with gentamicin sulphate. The epidermal surfaces were dosed with 26 micrograms lyngbyatoxin A/cm2 dissolved in 13 microliters dimethyl sulphoxide/cm2. The diffusion chambers were incubated at 36 degrees C for varying periods (1.0-24 hr). HPLC was used to quantify lyngbyatoxin A. Skin penetration was calculated by summing the amount of lyngbyatoxin A recovered from the dermis and receptor fluid. The mean partition coefficient for lyngbyatoxin A was 1.53. Penetration of lyngbyatoxin A (expressed as a percentage of dose, n = 3) in guinea pig and human skin was 23 and 6.2 (respectively) after 1 hr of topical exposure. The amount of lyngbyatoxin A in the dermis and receptor fluid did not change significantly over time.
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424
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Kemppainen BW, Mehta M, Stafford R, Riley RT. Effect of vehicle on skin penetration and retention of a lipophilic red tide toxin (PbTx-3). Toxicon 1992; 30:931-5. [PMID: 1523686 DOI: 10.1016/0041-0101(92)90393-j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to determine the effect of carrier vehicle on the penetration of brevetoxin ([3H]PbTx-3) into skin layers and receptor fluid. Disks of guinea-pig skin were mounted on penetration chambers. Epidermal surfaces were dosed with 0.320 microgram/cm2 of PbTx-3 dissolved in 50 microliters of vehicle [water, methanol, or dimethylsulfoxide (DMSO)]. In vitro skin penetration by PbTx-3 during 24 hr of exposure was 6.2, 2.3 and 26% for water, methanol, and DMSO, respectively (expressed as % of dose applied).
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425
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Qian M, Swagler AR, Fong KL, Crysler CS, Mehta M, Gallo JM. Pharmacokinetic evaluation of drug interactions with anti-human immunodeficiency virus drugs. V. Effect of soluble CD4 on 2',3'-dideoxycytidine kinetics in monkeys. Drug Metab Dispos 1992; 20:396-401. [PMID: 1355714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
This study was conducted to determine if soluble CD4 (ST4) altered the pharmacokinetics of 2',3'-dideoxycytidine (ddC) in nonhuman primates. Each of six monkeys received 5 mg/kg of ddC iv in the absence and presence of two different iv regimens of ST4. The ST4 regimens produced steady-state plasma concentrations of 10.3 micrograms/ml (N = 3) and 22.2 micrograms/ml (N = 3) for 30 min following ddC administration. Pharmacokinetic parameters for ddC and ST4 were calculated based on plasma and urine concentrations of ddC and plasma concentrations of ST4. Following combined ddC and ST4 administration, in both the low- and high-dose ST4 groups, plasma concentration-time profile of ddC were similar for each monkey, and no statistical differences were observed in the pharmacokinetic parameters compared with those obtained when ddC was given alone. Complete urinary excretion data for ddC was obtained in 3 of the 6 animals studied. At the low ST4 dose, one animal had a reduced renal clearance of ddC, whereas at the high ST4 dose two animals recorded an increased renal clearance of ddC. ST4 plasma concentrations were comparable to in vitro concentrations of antiviral activity, with pharmacokinetic parameters similar to those reported previously. The kinetic information provides a basis for rational dosage design for combination chemotherapeutic regimens of ddC and ST4 in human immunodeficiency virus infection.
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