626
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Qazi SA, Khan S, Khan MA. Epidemiology of childhood tuberculosis in a hospital setting. J PAK MED ASSOC 1998; 48:90-3. [PMID: 9783041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Two hundred paediatric cases of tuberculosis were studied over two years. The children usually presented with fever, cough, weight loss or failure to thrive and pallor. The diagnosis was based on history, clinical examination, chest and other relevant radiographs, Mantoux test, erythrocyte sedimentation rate (ESR) and where necessary cerebrospinal, pleural and ascitic fluid examinations and lymph gland histopathology were done. The most commonly affected age group was between 2-5 years and pulmonary tuberculosis was the most frequent diagnosis followed by tuberculous adentitis.
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627
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Khan MA, Qadri SY, Tomar S, Fish D, Gururajan L, Poria MS. Induction of hepatic cytochrome P-450 by phenobarbital in semi-aquatic frog (Rana pipiens). Biochem Biophys Res Commun 1998; 244:737-44. [PMID: 9535735 DOI: 10.1006/bbrc.1998.8281] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hepatic microsomal cytochrome P450 (equivalent to rat P4502B1 isozymic form, a CYPIIB gene product) can be induced by pentobarbital (PB) in the adults of the semiaquatic frog, Rana pipiens (as in other terrestrial vertebrates), but not in adults of the aquatic frog Xenopus laevis or in bluegill sunfish (Lepomis macrochirus). The activity of PB-induced P450 (2B1) towards aldrin and pentoxyresorufin increases respectively by about 2- and 10-fold. This enzyme is not inducible during larval and postlarval stages of R. pipiens. However, cytochrome P4501A1 (CYPIA1 gene product) is inducible by beta-naphthoflavone in all these species. Both CYPIA and CYPIIB genes are expressed, as determined by the catalysis of their protein products, during larval, postlarval, and adult stages of R. pipiens. The concentration of P450 increases slightly during the postlarval stages until the adult stage, ready to migrate to land, is reached. This increase seems to be mostly due to 2B1-type cytochrome P450 as judged by a large increase in aldrin epoxidase but not of 7-ethoxyresorufin O-deethylase activity. It is hypothesized that the evolution of true terrestrialness, and not the evolution of air-breathing lungs alone, is required for the transcriptional activation of CYPIIB gene by PB.
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628
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Khan MA, Sinha S, Hayton S, Fynn S, Henderson RA, Bennett DH. A normal electrocardiogram precludes the need for left ventriculography in the assessment of coronary artery disease. HEART (BRITISH CARDIAC SOCIETY) 1998; 79:262-7. [PMID: 9602660 PMCID: PMC1728645 DOI: 10.1136/hrt.79.3.262] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To assess whether a normal electrocardiogram can identify good left ventricular function and obviate the need for routine left ventriculography in patients undergoing cardiac catheterization for suspected coronary artery disease. DESIGN A prospective study of patients undergoing cardiac catheterisation. SETTING A regional cardiac centre. PATIENTS The electrocardiograms, coronary angiograms, and left ventriculograms of 391 consecutive patients undergoing investigations for suspected coronary artery disease were entered into the study. Patients with arrhythmias and cardiac pathologies other than coronary artery disease were excluded. MAIN OUTCOME MEASURES The electrocardiogram was assessed using a 29 point QRS scoring system, and classified by two cardiologists and a trainee cardiologist as normal or abnormal. Left ventricular function was assessed by digital ventriculography. RESULTS The sensitivity, specificity, and negative predictive value of a QRS score of 0 (normal QRS complexes) for discriminating good left ventricular function (ejection fraction > or = 50%) were 92.6%, 41.5%, and 97.2%, respectively. The figures for a normal electrocardiogram as assessed by a doctor were 96.3%, 40.4%, and 98.6% for cardiologist A; 96.3%, 37.4%, and 98.4% for cardiologist B; and 94.4%, 49.6%, and 98.2% for the cardiology trainee. CONCLUSIONS If a cardiologist judges the ECG to be normal, left ventriculography is unnecessary and a formal QRS score does not improve reliability of this clinical judgment. Adopting this strategy would save 30-40,000 Pounds in consumables and 65-87 hours of catheter laboratory and staff time for a department catheterising 3000 patients with suspected coronary artery disease annually.
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629
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Khan MA, Jovanovich LV, Martin LT, Qadri SY, Podowski AA. Effects of photoisomers of cyclodiene insecticides on liver and microsomal cytochrome P450 in rats. Arch Toxicol 1998; 72:74-83. [PMID: 9456078 DOI: 10.1007/s002040050471] [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: 02/06/2023]
Abstract
Threshold dosages of the photoisomers of cyclodiene insecticides, namely photochlordane, photodieldrin, and photoheptachlor, for the induction of hepatic microsomal cytochrome P450 (P450) and liver hypertrophy in male rats were at least one-quarter of those reported for corresponding parent cyclodienes. Maximum increase in total P450 concentration (30%) and demethylases activities (100%) was always respectively one-third or one-tenth of that reported for parent cyclodienes. The P450 isozymic form induced by photoheptachlor resembled that induced by pentobarbital (P4502B1) in its substrate specificity, spectral characteristics, and electrophoretic mobility. The induction of P450 was initially followed by hepatic hypertrophy. However, higher dosages of photoisomers caused wasting and lowered both the liver weight and the activity of aniline hydroxylase while those of mirex and endrin, which also caused wasting and lowered aniline hydroxylase activity, continued causing further hepatic hypertrophy.
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630
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Kommuru TR, Khan MA, Ashraf M, Kattenacker R, Reddy IK. A simplified chromatographic method for quantitative determination of coenzyme Q10 in dog plasma. J Pharm Biomed Anal 1998; 16:1037-40. [PMID: 9547707 DOI: 10.1016/s0731-7085(97)00057-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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631
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Khan MA, Hill RP, Van Dyk J. Partial volume rat lung irradiation: an evaluation of early DNA damage. Int J Radiat Oncol Biol Phys 1998; 40:467-76. [PMID: 9457837 DOI: 10.1016/s0360-3016(97)00736-0] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE 1. To investigate early DNA damage induced in rat lung cells following single-dose, partial-volume irradiation (lung base and lung apex). 2. To determine the variation in DNA damage in different lung regions. 3. To investigate the possible mechanisms associated with early DNA damage after lung irradiation. METHODS AND MATERIALS The whole lung or the upper or lower half of the entire lung of Sprague-Dawley rats was exposed to 10 Gy 60Co gamma rays. The animals were sacrificed at various times up to 42 h after irradiation. A trypsin-digested lung cell suspension was prepared and cells that attached to slides in the initial 24-h period were then grown in the presence of culture medium with cytochalasin-B for a further 72 h. Radiation-induced DNA damage was quantified in the cells (primarily fibroblasts) from both irradiated and unirradiated lung regions by using a well-characterized micronucleus assay. RESULTS When the lungs were removed at 16-18 h after whole-lung irradiation, about 0.85 micronuclei (MN) per binucleate cell (BNC) were observed in the lung cells of the irradiated animals, compared to 0.02 MN/BNC in the lung cells of the controls. When only the lung base was irradiated, the frequency of micronuclei was 0.85 MN/BNC compared to 0.43 MN/BNC observed in cells from the irradiated lung apex. Of particular interest was the finding that the unirradiated lung apex also showed a large frequency of micronuclei (0.43 MN/BNC) after the irradiation of the lung base, whereas the unirradiated lung base showed only a marginal (approximately 2-fold) increase relative to the spontaneous frequency following irradiation of the lung apex. The changes in the frequency of micronuclei varied with the time at which the lungs were removed from the rats for early times, but had stabilized by 18 h after irradiation. Normal (unirradiated) cells grown in filtered or unfiltered conditioned media obtained from irradiated cell cultures showed an insignificant marginal increase in the number of micronuclei relative to the spontaneous frequency. Lung cells obtained from the lung base or the lung apex of healthy controls and irradiated separately in vitro showed no regional differences in the induction of micronuclei. Cells from the lungs of rats injected with superoxide dismutase, within 1 h prior to irradiation of the lung base, and processed 16-18 h after irradiation showed a reduction in the number of MN in the shielded lung apex, indicating the possible involvement of oxygen radicals. CONCLUSIONS These data indicate that cells in the lung base sustain more DNA damage than those in the lung apex when either region is irradiated; however, when the whole lung, is irradiated, the lung damage observed is similar in the two regions. Also, out-of-field effects are observed for the lung apex but not the lung base. Possible mechanisms include a clastogenic (chromosome damaging) factor produced in the plasma following irradiation and/or the production of oxygen radicals by activated lymphocytes/monocytes. The partial blocking of the DNA damage, observed in the unirradiated lung apex following irradiation of the lung base, by superoxide dismutase, suggests that oxygen radicals are involved in this out-of-field effect. These radicals are likely produced as a result of the induction of inflammatory cytokines, such as tumor necrosis factor (TNF) and interleukin-1 (IL-1) by the irradiation. The reason for the lack of an out-of-field effect in the lung base when the lung apex is irradiated is unknown, but may be due to the greater volume of lung irradiated in the lower lung field, because this is likely to affect the level of cytokines produced. Alternatively, it may reflect cytokines produced as a result of the partial liver irradiation that occurs with the lower lung field.
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632
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Khan MA, Baseer A. Magnitude of lipoprotein (a) in diabetes mellitus. J PAK MED ASSOC 1998; 48:11-3. [PMID: 9610080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
One hundred and three patients, 76 with diabetes mellitus alone (48- Non-Insulin dependent diabetes and 28 Insulin dependent diabetes) and 27 diabetics having coronary heart disease (CHD) and 27 normal control subjects were included in this study. All the 27 diabetics with CHD were Non-Insulin dependent. The patients and the controls were investigated for serum Lp (a), triglycerides, cholesterol, VLDL-C, LDL-C, HDL-C, apo A1 and apo B. The objective was to assess and compare the level of lipoproteins, especially the lipoprotein (a), in diabetic and non-diabetic subjects and to compare the level of the aforementioned parameters in diabetics with and without CHD. The Lp (a) and other lipid parameters were significantly raised (P < 0.001) except HDL-C and apo A1 that were significantly decreased (P < 0.001) both in diabetic patients with and without CHD, as compared to the control group. The diabetics with CHD showed significantly elevated (P < 0.001) Lp (a) and lipid profile, and significantly low (P < 0.001) HDL-C and apo A1 levels as compared to the patients having diabetes alone. No significant difference was observed in the levels of the above parameters when NIDDM patients were compared with IDDM group. In both NIDDM and IDDM patients significantly low (P < 0.001) HDL-C level and significantly high (P < 0.001) Lp (a) level along with the aforementioned lipid parameters was observed as compared to control group. Elevated levels of Lp (a) and lipid profile in diabetic subjects suggest their involvement in atherogenesis and subsequent development of CHD.
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633
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Khan MA, Soni M, Khan MD. Development of primary eye care as an integrated part of comprehensive health care. COMMUNITY EYE HEALTH 1998; 11:24-6. [PMID: 17492028 PMCID: PMC1706055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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634
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Khan MA, Hellawell GO, Nargund VH. Ureteric obstruction due to B-cell lymphoma. Int Urol Nephrol 1997; 29:541-2. [PMID: 9413760 DOI: 10.1007/bf02552198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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635
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Cheng HC, Khan MA, Bogdanov A, Kwong K, Weissleder R. Relative blood volume measurements by magnetic resonance imaging facilitate detection of testicular torsion. Invest Radiol 1997; 32:763-9. [PMID: 9406017 DOI: 10.1097/00004424-199712000-00007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES The authors determine the utility of relative blood volume measurements (rBV) using a blood pool marker for magnetic resonance imaging (MRI) in detection of early testicular torsion. METHODS Testicular torsion was induced in rats by counterclockwise 720 degrees rotation and fixation of the testis in the scrotum. MPEG-PL-DTPA-Gd enhanced MRI (30 mumol Gd/kg bolus injection) was performed 1 hour after torsion at 1.5 T using fat-suppressed three-dimensional fast spoiled gradient-recalled sequence for relative blood volume measurement and three-dimensional time-of-flight sequence for MR angiography (MRA). RESULTS The rBV of the torqued testes was significantly lower (13.3% +/- 13.5%) than that of testes with sham operation (97.7% +/- 5.3%; P < 0.05). Rats with testicular torsion showed larger regions of ischemia than did animals with sham operation (63.4% +/- 13.0% versus 4.0% +/- 2.8% of all pixels in testis; P < 0.01). The MRA of testicular torsion showed engorgement of the distal testicular vein as a sign of venous compression or total disappearance of the testicular vein, indicating arterial insufficiency. CONCLUSIONS The authors conclude that MPEG-PL-DTPA-Gd can be used to obtain functional (rBV), morphologic (tunica enhancement), and angiographic (venous engorgement, arterial compromise) findings that should improve the diagnosis of testicular torsion in the acute setting.
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636
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Kunta JR, Goskonda VR, Brotherton HO, Khan MA, Reddy IK. Effect of menthol and related terpenes on the percutaneous absorption of propranolol across excised hairless mouse skin. J Pharm Sci 1997; 86:1369-73. [PMID: 9423148 DOI: 10.1021/js970161+] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The potential use of terpenes/terpenoids as penetration enhancers in the transdermal delivery of propranolol hydrochloride (PL) was investigated. PL was chosen for the reasons of its extensive first-pass metabolism and short elimination half-life. The terpenes studied included L-menthol, (+)-limonene, (+/-)-linalool, and carvacrol at 1%, 5%, and 10% w/v concentrations. The diffusion of PL across excised hairless mouse skin was determined using side-by-side diffusion cells. Flux, permeability coefficient (Pm), and lag time (tL) were calculated. PL showed comparable lag times with menthol at all three concentration levels. At a 1% level of carvacrol, PL exhibited a 2.4- and 2.2-fold increase in lag time compared with 5 and 10% levels of enhancer, respectively. In the presence of limonene, PL had shown maximum lag time (between 3.0 and 3.3 h) at all three levels. In the case of linalool, the lag times for PL with 5 and 10% levels of enhancer were 7.0- and 5.2-fold less compared with 1% level. A significant (p < 0.05) concentration effect was observed only with linalool. Hydrogel-based patches were formulated with or without menthol as enhancer. Release profiles from the hydrogel formulations obeyed zero-order kinetics. The permeability of propranolol was significantly higher (p < 0.05) from the test patch than the control (no enhancer) patch across the mouse skin. The mechanism of permeation enhancement of menthol could involve its distribution preferentially into the intercellular spaces of stratum corneum and the possible reversible disruption of the intercellular lipid domain. The results suggest the potential use of menthol as effective penetration enhancer in the delivery of significant amounts of PL through skin.
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637
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Khan MA, Rahman M, Khanam PA, Kane TT, Ashraf A. Awareness of sexually transmitted disease among women and service providers in rural Bangladesh. Int J STD AIDS 1997; 8:688-96. [PMID: 9363543 DOI: 10.1258/0956462971919066] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Sexually transmitted disease (STD) in rural Bangladesh is currently a topic of great concern. To date, little information is available in the literature regarding its prevalence. It is now known, however, that the current level of STD awareness among the rural population with regard to modes of transmission and means of prevention is inadequate. In 1994, the MCH-FP Extension Project (Rural) of ICDDR, B surveyed 8674 married women of reproductive age (MWRA) in 4 rural thanas to examine their awareness of STDs. The association between socio-demographic and programmatic factors (variables which affect STD information availability) and awareness of STDs was examined by both bivariate and multivariate analyses. Seven focus group discussions were conducted among groups of government health and family planning workers and paramedics to assess their knowledge of STDs and attitudes about their prevention. Only 12% of the original group had even a basic understanding about STDs and how to protect themselves from them. Twenty-five per cent of the women surveyed had ever heard of either syphilis or gonorrhoea. Of these women, less than half could mention specific mechanisms involved in the transmission of these diseases. Seven per cent reported that syphilis and gonorrhoea are transmitted through sexual intercourse. Thirteen per cent reported that the infections are transmitted from spouses to their partners. Four per cent reported that STDs can be spread by having multiple sexual partners. The results of logistic regression analysis indicate that awareness of STDs was higher among relatively older women than among younger women. Awareness of STDs was most strongly and positively associated with the education of both the women and their husbands. Awareness of STDs was also found to be higher among women who were more socially mobile (e.g. those who frequent cinemas or mothers' clubs). The findings of focus group discussions indicate that family planning and health care service providers have a moderate level of STD awareness. Modes of transmission and means of prevention, however, were areas of weakness. It will, therefore, be necessary, whether to prevent a potential STD epidemic or to combat current STD prevalence, to implement culturally acceptable and affordable means of disseminating knowledge in rural areas of Bangladesh. Training of health care providers will be an essential first step.
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638
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Brooks AL, Bao S, Harwood PW, Wood BH, Chrisler WB, Khan MA, Gies RA, Cross FT. Induction of micronuclei in respiratory tract following radon inhalation. Int J Radiat Biol 1997; 72:485-95. [PMID: 9374428 DOI: 10.1080/095530097142988] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Male Wistar rats were exposed to radon and its progeny (0.0, 60, 262 and 564 working level months, WLM), and the frequency of micronuclei was determined in deep lung fibroblasts, and deep lung, trachea and nasal epithelial cells with slopes of 0.28, 0.67, 0.34 and 0.11 micronuclei/1000 binucleated cells/WLM respectively. Micronuclei in deep lung fibroblasts, isolated and cultured using two methods and media, demonstrated no differences in slopes. Biological damage was used as a biodosimeter to calculate the relationship between dosimetric units: alpha particle traversals or 'nuclear hits', dose in mGy and exposure in WLM. The estimated number of nuclear alpha traversals/Gy was 6.3. Radon exposure to 170 WLM resulted in the same frequency of micronuclei in deep lung epithelial cells as produced by one alpha hit/cell nucleus. Absorbed dose/unit of exposure (mGy/WLM) was estimated assuming the damage was related to absorbed dose or to changes in cell sensitivity and ranged from 1.13 to 1.34 for deep lung epithelial cells, 0.47 to 1.09 for deep lung fibroblasts, 0.34 to 0.67 for tracheal epithelial cells and 0.18 to 0.33 for nasal epithelial cells. Biological dosimetry can be used to relate exposure to damage, compare dosimetric units and validate physical dosimetry models. This approach can be applied to any inhaled material capable of producing biological damage.
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639
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Jan IA, Hazir T, Qazi A, Khan MA, Khan NA. Fulminant pseudomembranous colitis leading to total colonic stricture. J PAK MED ASSOC 1997; 47:287-8. [PMID: 9510634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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640
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van der Heijde D, Bellamy N, Calin A, Dougados M, Khan MA, van der Linden S. Preliminary core sets for endpoints in ankylosing spondylitis. Assessments in Ankylosing Spondylitis Working Group. J Rheumatol 1997; 24:2225-9. [PMID: 9375888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
An international working group was formed to select core sets to be used as endpoints in clinical trials in ankylosing spondylitis (AS). The results of the first steps of the selection of these core sets are described. The definition of the settings for which the core set will be intended are defined. The methods used to select the core sets were a combination of literature search, nominal group discussions, and plenary discussions. The following settings were defined: disease controlling antirheumatic therapy (DC-ART), symptom modifying antirheumatic drugs (SMARD)/physical therapy, and clinical record keeping. Over 110 variables used as endpoints in AS were found in the literature. The preliminary core set for DC-ART consists of physical function, pain, spinal mobility, patient global assessment, peripheral joints/entheses, x-ray spine. The selected core set for SMARD/physical therapy includes physical function, pain, spinal mobility, spinal stiffness, and patient global assessment. The core set for clinical record keeping includes all measures of the SMARD/physical therapy core set completed by peripheral joints/entheses, and acute phase reactants. Three preliminary core sets for AS have been defined. Further research will be performed to select specific measures for all domains.
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641
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Khan MA, Hussain R, Khan SH, Umar M. Open fractures caused by high velocity missiles: the outcome of treatment of 39 fractures followed for 1-3 years. J PAK MED ASSOC 1997; 47:274-8. [PMID: 9510630] [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]
Abstract
Between 1993 and 1995, thirty-three patients having 39 fractures caused by missiles fired from a high velocity rifle were reviewed retrospectively between 1 and 3 years after injury and the outcome of treatment assessed. Majority (33 out of 39) were Grade III. Union was achieved in 35 out of 39 fractures, there was deep infection and delayed union in one case each. Non-union occurred in three fractures. The fractures were stabilized using different techniques, but highest complication rate was seen with the use of the static external fixator. This was related to the severe nature of the injury as well as the inherent limitations of the external fixator. Revision of the external fixator with internal fixation after healing of the soft tissues seems to be the direction of the future.
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642
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Khan MA, Canhoto AJ, Housley PR, Creek KE, Pirisi L. Glucocorticoids stimulate growth of human papillomavirus type 16 (HPV16)-immortalized human keratinocytes and support HPV16-mediated immortalization without affecting the levels of HPV16 E6/E7 mRNA. Exp Cell Res 1997; 236:304-10. [PMID: 9344611 DOI: 10.1006/excr.1997.3729] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated the effects of the glucocorticoids hydrocortisone and dexamethasone on human papillomavirus type 16 (HPV16)-mediated human cell carcinogenesis using normal human keratinocytes (HKc) and HKc immortalized by transfection with HPV16 DNA (HKc/HPV16). Normal HKc did not require glucocorticoids for proliferation. In contrast, growth of early passage HKc/HPV16 strictly required these hormones, although glucocorticoid dependence became less stringent during in vitro progression. Glucocorticoid dependence was acquired by HKc early after immortalization with HPV16 DNA, and glucocorticoids were required for efficient HKc immortalization. However, treatment of HKc/HPV16 with hydrocortisone or dexamethasone did not increase the steady-state levels of HPV16 E6/E7 mRNA or protein. Firefly luciferase activity expressed under the control of the HPV16 upstream regulatory region and P97 promoter increased by about fourfold following dexamethasone treatment of HeLa, but only twofold in HKc/HPV16, and less than twofold in SiHa. However, all of these cell lines expressed sufficient endogenous glucocorticoid receptors to allow for a dexamethasone response of the mouse mammary tumor virus promoter. These results indicate that mechanisms other than a direct influence by glucocorticoids on HPV16 early gene expression may contribute to the striking biological effects of these steroids on HPV16-mediated human cell carcinogenesis.
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643
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Akhtar MJ, Khan MA, Ahmad I. High performance liquid chromatographic determination of folic acid and its photodegradation products in the presence of riboflavin. J Pharm Biomed Anal 1997; 16:95-9. [PMID: 9447556 DOI: 10.1016/s0731-7085(96)02028-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A high performance liquid chromatographic procedure was developed to determine folic acid and its photodegradation products, p-aminobenzoic acid, pterine-6-carboxylic acid, p-aminobenzoyl-L-glutamic acid, and pteroic acid in the presence of riboflavin. The method involves reversed phase, paired-ion chromatography on mu-BondaPak C18 column using a UV detector (254 nm), and isocratic solvent system (at ambient temperature) comprising 0.017 M monobasic potassium phosphate, tetrabutyl ammonium hydroxide solution (20%, aqueous) and methanol (870:15:250, v/v). The range of quantitation for the individual compounds was found to be: p-aminobenzoic acid, 0.01 - 1.25 x 10(-5) M; pterine-6-carboxylic acid, 0.01-2.0 x 10(-5) M; p-aminobenzoyl-L-glutamic acid, 0.02-2.0 x 10(-5) M; pteroic acid, 0.02-2.5 x 10(-5) M; folic acid, 1.0-5.0 x 10(-5) M; riboflavin, 1.0-5.0 x 10(-5) M. Linear regression analysis of the data demonstrates adequate performance of the method in terms of accuracy and precision (R. S. D. 3%). The method is specific, rapid and convenient and has been applied to photodegradation studies of folic acid in the presence and absence of riboflavin.
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644
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Butt TS, Khan A, Ahmad A, Khan MA, Parke A, Hill DR. Pasteurella multocida infectious arthritis with acute gout after a cat bite. J Rheumatol Suppl 1997; 24:1649-52. [PMID: 9263167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A 74-year-old man with chronic lymphocytic leukemia, immune purpura, and gout presented with a painful, swollen ankle after a cat bite to his leg. On aspiration of the ankle, gram negative pleomorphic rods and monosodium urate crystals were seen and Pasteurella multocida was cultured. He was treated with ampicillin/sulbactam, joint aspiration, and intraarticular steroids, with resolution of infection and return of joint function. The syndromes of Pasteurella arthritis and crystal arthropathy with septic arthritis are reviewed.
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645
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Vincent F, Nagashima M, Takenoshita S, Khan MA, Gemma A, Hagiwara K, Bennett WP. Mutation analysis of the transforming growth factor-beta type II receptor in human cell lines resistant to growth inhibition by transforming growth factor-beta. Oncogene 1997; 15:117-22. [PMID: 9233784 DOI: 10.1038/sj.onc.1201166] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The transforming growth factor-beta (TGF-beta) binds the type II TGF-beta growth factor receptor (RII) to inhibit the growth of most epithelial tissues. Most human colon and gastric cancers with microsatellite instability (MI) have frameshift mutations in polynucleotide repeats within the RII coding region; these mutations truncate the receptor protein and disable the serine/threonine kinase to produce TGF-beta resistance. To further investigate the type, frequency and tissue distribution of RII mutations, we selected 24 human cancer cell lines from various tissues which were previously reported to be resistant to the inhibitory effects of TGF-beta. We developed protocols for non-isotopic SSCP analysis of PCR products from genomic DNA samples, and we tested them for microsatellite instability. PCR-SSCP analysis followed by DNA sequencing identified deletion mutations in the exon 3 poly-adenine tract in three colon tumor cell lines: LS174T and SW48 had a single base deletion and LS411 had a two base deletion. Among the 24 previously unreported cell lines, only these three demonstrated microsatellite instability. These and other recent data indicate that RII mutations are essentially confined to colon and gastric cancers with microsatellite instability. The narrow spectrum of tissues containing RII mutations illustrates the complexity of genetic checkpoints in human carcinogenesis.
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Coursen JD, Bennett WP, Khan MA, Forrester K, Pietenpol JA, Harris CC. Differential effects of p53 mutants on the growth of human bronchial epithelial cells. Mol Carcinog 1997; 19:191-203. [PMID: 9254886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated the effects of five different p53 mutants on the growth of primary cultures of normal human bronchial epithelial (NHBE) cells. The five defective viral pZIP-Neo constructs contained the following mutations at mutational hot-spots found in human cancers: codons 143ala, 175his, 248trp, 249ser, and 273his. NHBE cells were infected with the p53 mutants, wild-type p53, or the pZIP-Neo vector control. The 143ala, 248trp, and 273his mutants, as well as wild-type p53, decreased the colony-forming efficiency and inhibited the growth of NHBE cells. The 175his mutant did not significantly change the growth rates. In NHBE cells from three donors, the 249ser mutant conferred a substantial growth advantage to the NHBE cells in a colony-forming-efficiency assay. In NHBE cells isolated from one donor, the 249ser mutant also produced a significant life span extension. These cells grew rapidly through 80 population doublings and entered an apparent "crisis" in passage 14. Karyotypic analyses of one culture at multiple passages revealed aneuploid populations with alterations of chromosomes 5, 11, and 13; quantitative DNA analysis detected aneuploidy in late passages from that culture and two other primary cultures. These data demonstrated that the codon 249ser mutation could provide a growth advantage to bronchial epithelial cells and suggest that this mutant protein can induce genomic instability.
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647
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Khan MA, Trevathan LE, Robbins JT. Quantitative Relationship Between Leaf Rust and Wheat Yield in Mississippi. PLANT DISEASE 1997; 81:769-772. [PMID: 30861890 DOI: 10.1094/pdis.1997.81.7.769] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Yield losses in wheat (Triticum aestivum) caused by leaf rust were evaluated in cultivar trials at five locations in Mississippi over a 4-year period from 1986 through 1989. Different levels of disease developed in the various trials over the 4-year period. There was no significant interaction between location and cultivar when yield data were collected from sites in the north and central areas of the state. A model derived from data for eight cultivars at two locations showed a negative linear relationship between yield and leaf rust. Total grain yield was reduced by 1% for each 1% increase in rust when the percentage flag leaf area covered by pustules was assessed visually at Feekes stage 11.1. Using this model, and rust ratings from three additional locations, predicted yields were statistically similar to recorded yields.
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Khan MA, Salahuddin I. Intranasal meningoencephalocele and the use of fibrin glue. EAR, NOSE & THROAT JOURNAL 1997; 76:464-7. [PMID: 9248140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Meningoencephaloceles are rarely seen in adults. This case report illustrates the management of a large intranasal meningoencephalocele in an adult man. Excision of this lesion resulted in a defect in the cribriform plate which was closed using tissue and fibrin glue.
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