1276
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Hollander VP, Khan S. The ether-catalyzed dissociation rate of estradiol-receptor complex distinguishes between hormone-sensitive and resistant rat mammary tumors. JOURNAL OF STEROID BIOCHEMISTRY 1980; 12:131-4. [PMID: 6252377 DOI: 10.1016/0022-4731(80)90262-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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1277
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Khan S, Mukhtar H, Pandya KP. n-Octane and n-nonane induced alterations in xenobiotic metabolising enzyme activities and lipid peroxidation of rat liver. Toxicology 1980; 16:239-45. [PMID: 7423533 DOI: 10.1016/0300-483x(80)90120-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
After 2 and 7 days on n-octane and n-nonane administration (intraperitoneally) to female albino rats, alterations in the levels of hepatic xenobiotic metabolising enzyme activities and TBA reactants were observed. Fifty to eighty per cent reduction in the specific activities of benzo[a]pyrene hydroxylase, benzphetamine-N-demethylase, p-nitroanisole-O-demethylase and glutathione-S-transferase were observed. Cytochrome P-450 and free sulfhydryl contents of liver were also decreased significantly after 7 days treatment on n-octane and n-nonane. A 2- and 3- fold increase in liver lipid peroxidation estimated as TBA reactants was observed in the animals treated for 2 or 7 days with n-octane or n-nonane.
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1278
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Khan S, Haust MD. Variations in the aortic origin of intercostal arteries in man. Anat Rec (Hoboken) 1979; 195:545-52. [PMID: 507408 DOI: 10.1002/ar.1091950313] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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1279
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Abstract
The relationship between the activity of the cystic fibrosis serum ciliary dyskinesia factor, detected by the rabbit tracheal bioassay, and clinical status of the patient has been investigated in children, 1-24 years old, with cystic fibrosis. No significant correlation was found between the amount of serum factor activity and age, clinical status assessed by the Schwachman score, pulmonary function (vital capacity, functional residual capacity, total lung capacity, residual volume, maximum breathing capacity, maximal midinspiratory flow, and maximal midexpiratory flow) or blood gas levels (pCO2, pO2). The activity showed no significant relationship to serum galactosyltransferase activity in children with cystic fibrosis.
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1280
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Srivastava RC, Khan S, Shankar U, Pandya KP. Distribution of Fe59 in benzene and iomex treated rats. Arch Toxicol 1979; 42:43-9. [PMID: 454184 DOI: 10.1007/bf00351823] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The distribution of Fe59 in plasma and blood at various time intervals has been studied in control, benzene and iomex administered, and anemic rats. A significant difference between control and benzene, and iomex treated animals was observed in the rate of reappearance of Fe59 in blood circulation. The accumulation of Fe59 in various organs was noted at the end of 48 h. A significant increase in the radio-iron content was observed in bone marrow, spleen and liver of benzene and iomex treated rats as compared to those of control rats.
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1281
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El-Domeiri AA, Khan S. Tumours of the parotid gland: the significance of tumour size and facial nerve involvement. Clin Oncol (R Coll Radiol) 1979; 5:17-24. [PMID: 421384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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1282
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1283
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DeLap RJ, Rush MG, Zouzias D, Khan S. Isolation and preliminary characterization of the small circular DNA present in African green monkey kidney (BSC-1) cells. Plasmid 1978; 1:508-21. [PMID: 107539 DOI: 10.1016/0147-619x(78)90008-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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1284
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Khan S, Macnab RM, DeFranco AL, Koshland DE. Inversion of a behavioral response in bacterial chemotaxis: explanation at the molecular level. Proc Natl Acad Sci U S A 1978; 75:4150-4. [PMID: 360210 PMCID: PMC336069 DOI: 10.1073/pnas.75.9.4150] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Certain cheU mutants of Salmonella show inverted chemotactic behavior, being repelled by attractants and attracted by repellents. Such a dramatic change in behavioral pattern would seem at first glance to require drastic and complex alterations in the sensory processing system. In fact, the behavior can be explained by a simple shift in the level of a response regulator and the subtle effects of this shift on flagellar function. Flagella can exist in either a left-handed or a right-handed structure depending on applied torsion. Wild-type cells swim smoothly by counterclockwise rotation of a left-handed helical bundle and tumble when the motors briefly reverse to clockwise rotation (normal random motility). The cheU mutation causes a shift in response regulator level relative to the critical threshold value, resulting in extended clockwise operation so that the flagella are fully converted to the right-handed helical form. These cells therefore swim smoothly by clockwise rotation of a right-handed bundle and tumble when the motor briefly reverses to counterclockwise rotation (inverse random motility). Thus, tumbling is associated with brief reversals and not with a particular sense of rotation. A wild-type cell, with its steady-state response regulator level placing it initially in normal random motility, will swim smoothly on addition of attractant, whereas a cheU mutant with inverse random motility will tumble given the same stimulus. The phenomenon illustrates the profound behavioral consequences that can result from a single mutation in a key gene.
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1285
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Diamond EJ, Khan S, Koprak S, Hollander VP. Inhibition of ovariectomy-induced rat mammary tumor regression by a mammosomatotropic tumor. Cancer Res 1978; 38:2239-45. [PMID: 208762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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1286
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Miranda AF, Nette EG, Khan S, Brockbank K, Schonberg M. Alteration of myoblast phenotype by dimethyl sulfoxide. Proc Natl Acad Sci U S A 1978; 75:3826-30. [PMID: 278996 PMCID: PMC392880 DOI: 10.1073/pnas.75.8.3826] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Application of dimethyl sulfoxide to proliferating L8 myoblasts (an established cell line of rat skeletal muscle) for 72 hr completely prevented fusion and induction of creatine phosphokinase (EC 2.7.3.2) activity (an indicator of muscle differentiation). The growth pattern changed from the usual sheets of randomly oriented cells to flattened, whorled monolayers of elongated fibroblast-like cells. By electron microscopy, rough endoplasmic reticulum increased and extracellular material appeared that had the morphologic and staining characteristics of collagen. After 120 hr in dimethyl sulfoxide-containing medium, the cells secreted about 6 times more collagen than untreated controls. Dimethyl sulfoxide was ineffective when applied to L8 cells just prior to fusion, and effects of dimethyl sulfoxide were not readily reversible unless treated cells were subcultured at low density.
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1287
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Singhal JP, Khan S, Bansal OP. Titrimetric method for the determination of oxamyl residues in crops and soils. Analyst 1978; 103:872-5. [PMID: 686387 DOI: 10.1039/an9780300872] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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1288
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Ghose RR, Mathur YB, Upadhyay M, Morgan WD, Khan S. Treatment of hypertensive emergencies with oral labetalol. BRITISH MEDICAL JOURNAL 1978; 2:96. [PMID: 667582 PMCID: PMC1605848 DOI: 10.1136/bmj.2.6130.96] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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1289
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Khan S, Qayum A, Yusuf SM. Some pharmacological actions of nitroharmidine nitrate. JPMA. THE JOURNAL OF THE PAKISTAN MEDICAL ASSOCIATION 1978; 28:79-8. [PMID: 99531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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1290
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Abstract
The adsorption of oxamyl
under variable conditions of time, pH and exchangeable cations on
montmorillonites has been examined. Kinetic studies showed the reaction to be
first order, which indicates diffusion-controlled adsorption. All the evidence
obtained by studies of the effect of pH, adsorption isotherms, considerations
of the chemical structure of the molecule, and X-ray diffraction and infrared
spectroscopy points to a reaction mechanism for oxamyl association with acid-
and base-saturated montmorillonites which involves either protonation or
coordination of the exchangeable clay cations to the carbonyl of the amide
group.
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1291
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Diamond EJ, Giladi M, Khan S, Hollander VP. Estradiol binding in ovariectomy-responsive and -nonresponsive rat mammary carcinoma. Cancer Res 1977; 37:1852-6. [PMID: 870188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
MTW9, a transplantable mammary tumor in Wistar-Furth rats, is dependent upon high levels of serum prolactin for growth. The mammary tumor can be maintained by coimplantation with a pituitary mammosomatotropic tumor (MTW9-MtT) or by chronic perphenazine administration (MTW9-P). MTW9-MtT does not regress after ovariectomy (OVEX) alone, while, MTW9-P regresses rapidly whether or not rats are maintained on perphenazine. Cytosol estradiol binding was determined in MTW9-MtT, 47.6 +/- 3.6 (N = 9), Kd 9.9 +/- 2.0 X 10(-11) M; MTW9-P, 195.5 +/- 9.1 (n = 16), Kd 27.6 +/- 4.7 X 10(-11) M; MTW9-P after perphenazine was withdrawn, 86.0 +/- 6.0 (n = 6), Kd 9.9 +/- 1.5 X 10(-11) M. Eight S and 4 S peaks were found in cytosols from both tumors by sucrose gradient centrifugation; the peaks differ qualitatively and quantitatively. The possibility that differences in binding levels result from sites filled with endogenous estradiol was critically examined and rejected. Withdrawal of perphenazine results in reduction of estradiol binding but retention of response to OVEX. Hence, response of MTW9-P to OVEX cannot be explained by the 3- to 4-fold increase in estradiol binding over MTW9-MtT. The relationship between estradiol binding and response to OVEX is under study using both mammary tumor models.
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1292
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Warren BA, Khan S. The scanning electron microscopy of the lysis of fibrin by endothelium. BRITISH JOURNAL OF EXPERIMENTAL PATHOLOGY 1975; 56:340-8. [PMID: 1174459 PMCID: PMC2072756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The lysis of a fibrin clot by sheets of endothelium one cell thick was examined by scanning electron microscopy. The unlysed fibrin film appeared as a densely matted surface, without interstices. Commencing lysis appeared as parallel ovals in which the dense matting was altered to show many strands of fibrin criss-crossing the lytic "window" with many interstices. The wall of the lytic crater surrounding the sheets of endothelium revealed a network of fibrin strands. There was condensation of the fibrin at the edge of the hole at the external surface. The floor of the crater contained sheets of endothelium which were recognized by the shape and size of the nuclei. Flocculent masses of precipitate were present on the endothelial cells in the floor of the crater and occasionally within the lysed ovals at the edge. These may be fibrin degradation products.
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1293
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Yusuf SM, Qayum A, Qureshi KA, Khan S. Nitroharmidine nitrate on neuromuscular transmission: a preliminary report. J PAK MED ASSOC 1975; 25:33. [PMID: 814287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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1294
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Cunliffe WJ, Forster RA, Greenwood ND, Hetherington C, Holland KT, Holmes RL, Khan S, Roberts CD, Williams M, Williamson B. Tetracycline and acne vulgaris: a clinical and laboratory investigation. BRITISH MEDICAL JOURNAL 1973; 4:332-5. [PMID: 4271323 PMCID: PMC1587436 DOI: 10.1136/bmj.4.5888.332] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A satisfactory clinical response to long-term oral tetracycline treatment was associated with a mean serum tetracycline of 1.98 mug/ml. The surface lipid showed an increased triglyceride, decreased free fatty acids, and decreased cholesterol, and the amount of keratin within the pilosebaceous duct was reduced. At this dose level there was no quantitative decrease in the bacterial flora though there was a decrease in the fatty acids. We believe that the latter was due to a direct inhibition by tetracycline on extracellular lipases.
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1295
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Figueroa E, Khan S, Kim JT, Moritani Y. Caries preventive filling with resin adhesive. Sealing property of pits and fissures. JOURNAL OF OSAKA DENTAL UNIVERSITY 1970; 4:175-8. [PMID: 5287787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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