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Ganzera M, Yayla Y, Khan IA. Analysis of the marker compounds of Rhodiola rosea L. (golden root) by reversed phase high performance liquid chromatography. Chem Pharm Bull (Tokyo) 2001; 49:465-7. [PMID: 11310675 DOI: 10.1248/cpb.49.465] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An HPLC method permitting the first simultaneous detection of 5 marker compounds (salidroside, rosarin, rosavin, rosin, rosiridin) of R. rosea was developed. A separation was achieved within 27 min by using C-18 column material, a phosphate buffer/acetonitrile gradient system and at a separation temperature of 60 degrees C. All five compounds could be detected at concentrations as low as 0.62 microg/ml and were clearly assignable in R. rosea plant material and commercial products. Therefore, this quantitative and qualitative applicability of the method offers efficient and reliable means for the evaluation of R. rosea and products thereof.
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102
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Muhammad I, Khan IA, Fischer NH, Fronczek FR. Two stereoisomeric pentacyclic oxindole alkaloids from Uncaria tomentosa: uncarine C and uncarine E. Acta Crystallogr C 2001; 57:480-2. [PMID: 11313600 DOI: 10.1107/s0108270101000932] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2000] [Accepted: 01/11/2001] [Indexed: 11/10/2022] Open
Abstract
The chloroform solvate of uncarine C (pteropodine), (1'S,3R,4'aS,5'aS,10'aS)-1,2,5',5'a,7',8',10',10'a-octahydro-1'-methyl-2-oxospiro[3H-indole-3,6'(4'aH)-[1H]pyrano[3,4-f]indolizine]-4'-carboxylic acid methyl ester, C(21)H(24)N(2)O(4).CHCl(3), has an absolute configuration with the spiro C atom in the R configuration. Its epimer at the spiro C atom, uncarine E (isopteropodine), (1'S,3S,4'aS,5'aS,10'aS)-1,2,5',5'a,7',8',10',10'a-octahydro-1'-methyl-2-oxospiro[3H-indole-3,6'(4'aH)-[1H]pyrano[3,4-f]indolizine]-4'-carboxylic acid methyl ester, C(21)H(24)N(2)O(4), has Z' = 3, with no solvent. Both form intermolecular hydrogen bonds involving only the oxindole, with N.O distances in the range 2.759 (4)-2.894 (5) A.
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103
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Akram M, Khan IA. Isolated pulmonic valve endocarditis caused by group B streprococcus (Streptococcus agalactiae)--a case report and literature review. Angiology 2001; 52:211-5. [PMID: 11269786 DOI: 10.1177/000331970105200309] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The pulmonic valve is the least commonly involved valve in infective endocarditis. Pulmonic valve endocarditis is usually associated with tricuspid valve endocarditis, and isolated pulmonic valve endocarditis is exceedingly rare. The predisposing factors for developing pulmonic valve endocarditis include a congenitally anomalous pulmonic valve, intravenous drug abuse, and the presence of indwelling intravenous or flow-directed pulmonary artery catheters. More cases of group B streptococcus endocarditis are being reported. The risk factors for group B streptococcus endocarditis include diabetes mellitus, cancer, alcoholism, malnutrition, immunocompromised status, intravenous drug abuse, postpartum and postabortion states, and underlying valvular disease. The vegetations of this type of endocarditis are usually large and have a higher tendency to result in embolism. The presentation of group B streptococcus endocarditis is usually acute and may result in rapid valve destruction if not treated promptly. A case of isolated pulmonic valve endocarditis caused by group B streptococcus, Streptococcus agalactiae, is presented that was diagnosed with multiplane transesophageal echocardiography in a 40-year old, alcoholic, malnourished man, who was successfully treated with intravenous penicillin G. The literature on the isolated pulmonic valve endocarditis caused by group B streptococcus is reviewed.
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104
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Khan IA. Management of hypertension: do we know all the questions? J PAK MED ASSOC 2001; 51:103-5. [PMID: 11381820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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105
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Khan IA, Thomas P. Disruption of neuroendocrine control of luteinizing hormone secretion by aroclor 1254 involves inhibition of hypothalamic tryptophan hydroxylase activity. Biol Reprod 2001; 64:955-64. [PMID: 11207213 DOI: 10.1095/biolreprod64.3.955] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Mechanisms governing the effect of polychlorinated biphenyl (PCB) toxicity on hypothalamic serotonergic function and the neuroendocrine system controlling LH secretion were investigated in Atlantic croaker (Micropogonias unulatus) exposed to the PCB mixture Aroclor 1254 (1 microg x g body weight(-1) x day(-1)) in the diet for 30 days. PCB treatment caused a decrease in hypothalamic 5-hydroxytryptamine (5-HT) concentrations and significant inhibition of hypothalamic tryptophan hydroxylase (TPH), the rate-limiting enzyme in 5-HT synthesis, but did not alter the activity of monoamine oxidase, the catabolic enzyme. Further, PCB treatment caused significant decreases in GnRH content in the preoptic-anterior hypothalamic area. Significant decreases in pituitary GnRH receptor concentrations and the LH response to the GnRH analogue (GnRHa) were also observed in PCB-exposed fish, possibly as a consequence of a decline in GnRH release. The possible association between impaired serotonergic and neuroendocrine functions after PCB treatment was explored using serotonergic drugs. Treatment of croaker with p-chlorophenylalanine, an irreversible TPH inhibitor, mimicked the effects of PCB on the GnRH system and the LH response to GnRHa. Bypassing the TPH-dependent hydroxylation step with the administration of 5-hydroxytryptophan restored 5-HT to control levels and prevented the deleterious effects of PCB on the neuroendocrine parameters. Moreover, slow-release GnRH implants prevented the PCB-induced decline in GnRH receptors and restored the LH response to GnRHa, suggesting that GnRH therapy can reverse PCB-induced disruption of LH secretion. These results demonstrate that TPH is one of the targets of PCB neurotoxicity and indicate that a decrease in 5-HT availability in PCB-exposed croaker results in disruption of the stimulatory 5-HT/GnRH pathway controlling LH secretion.
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106
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Bedir E, Khan IA. A new cyclolanostanol arabinoside from the rhizome of Cimicifuga racemosa. DIE PHARMAZIE 2001; 56:268-9. [PMID: 11265599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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107
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Huggett DB, Khan IA, Allgood JC, Block DS, Schlenk D. Organochlorine pesticides and metals in select botanical dietary supplements. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2001; 66:150-155. [PMID: 11116308 DOI: 10.1007/s0012800218] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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108
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109
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Pugh N, Khan IA, Moraes RM, Pasco DS. Podophyllotoxin lignans enhance IL-1beta but suppress TNF-alpha mRNA expression in LPS-treated monocytes. Immunopharmacol Immunotoxicol 2001; 23:83-95. [PMID: 11322652 DOI: 10.1081/iph-100102570] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
There exists a growing body of research which indicates that antimitotics such as taxol and colchicine influence cytokine gene expression. In the present study we examined the effect of podophyllotoxin and six analogs on nuclear factor kappa B (NF-kappa B) activation, and on interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) mRNA expression in human THP-1 monocytes. All compounds were inactive between 0.001microM and 10microM when tested alone. However, podophyllotoxin (0.1 microM) enhanced LPS-induced NF-kappa B activation and IL-1beta mRNA expression between 2 and 3-fold. In contrast, LPS-induced TNF-alpha mRNA expression was decreased between 3 and 6-fold. Comparable results were also observed with the three analogs acetylpodophyllotoxin, 4'-demethylpodophyllotoxin and alpha-peltatin. The remaining three analogs (podophyllotoxin-4-O-glucoside, beta-peltatin-beta-D-glucopyransoide and 1,2,3,4-dehydrodesoxypodophyllotoxin) were inactive. Clearly certain structural features such as the presence of a glycosidic group or ring aromatization results in loss of biological activity. Interestingly, the analogs that were inactive in our assays have also been previously shown to lack affinity for tubulin binding. These results suggest that during the initial hours of exposure to podophyllotoxin or specific analogs these compounds do not act as independent stimulants of human monocyte activation, but can selectively enhance or suppress LPS-induced cytokine gene expression.
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110
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Canel C, Dayan FE, Ganzera M, Khan IA, Rimando A, Burandt CL, Moraes RM. High yield of podophyllotoxin from leaves of Podophyllum peltatum by in situ conversion of podophyllotoxin 4- O-beta-D-glucopyranoside. PLANTA MEDICA 2001; 67:97-99. [PMID: 11270736 DOI: 10.1055/s-2001-10636] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Rehydration of powdered tissues of Podophyllum peltatum L. prior to extraction with an organic solvent allows endogenous beta-glucosidases to hydrolyze lignan 4-O-beta-D-glucosides in situ and increase the yield of podophyllotoxin. Aqueous extraction of rhizomes and leaves of P. peltatum yielded 4- to 10-fold greater quantities of podophyllotoxin than the traditional ethanolic extraction. Most significantly, leaves were shown to contain over 52 mg of podophyllotoxin per g of dry weight (5.2%), exceeding levels previously reported from any source. These results point to the use of leaves harvested from cultivated P. peltatum as an attractive alternative to the destructive collection of natural populations.
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111
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Khan IA. Single oral loading dose of propafenone for pharmacological cardioversion of recent-onset atrial fibrillation. J Am Coll Cardiol 2001; 37:542-7. [PMID: 11216976 DOI: 10.1016/s0735-1097(00)01116-5] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The efficacy and safety of the single dose oral loading regimen of propafenone for pharmacological cardioversion of recent-onset atrial fibrillation (AFib) was evaluated by analyzing the trials on the subject identified through a comprehensive literature search. Most of the trials used a single dose of 600 mg for oral loading. The success rates ranged from 56% to 83%, depending on the duration of AFib and follow-up after drug administration. The conversion time ranged from 110 +/- 59 to 287 +/- 352 min, depending on the duration of observation after drug administration. The single dose oral loading regimen of propafenone was significantly more efficacious than placebo in the first 8 h after administration but not at 24 h. Compared with the intravenous regimen, the oral regimen resulted in fewer conversions in the first 2 h, but both regimens were equally efficacious afterward. The oral propafenone regimen was as efficacious as the single dose oral loading regimen of flecainide but was superior to those of quinidine and amiodarone. The adverse effects reported were transient arrhythmia, reversible QRS-complex widening, transient hypotension and mild noncardiac side effects. The transient arrhythmias were chiefly at the time of conversion and included appearance of atrial flutter, bradycardia, pauses and junctional rhythm. No life-threatening proarrhythmic adverse effects were reported. The single oral loading dose of propafenone appears to be highly effective for conversion of recent-onset AFib, with a relatively rapid effect within 2 to 3 h and freedom from serious adverse effects.
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112
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Khan IA, Irfan SM. Cholestasis with hepatic fibrosis secondary to sarcoidosis--a case report. J PAK MED ASSOC 2001; 51:89-92. [PMID: 11321881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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113
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Khan IA, Murphy PM, Casciotti L, Schwartzman JD, Collins J, Gao JL, Yeaman GR. Mice lacking the chemokine receptor CCR1 show increased susceptibility to Toxoplasma gondii infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1930-7. [PMID: 11160241 DOI: 10.4049/jimmunol.166.3.1930] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chemokines are critical for the recruitment of effector immune cells to sites of infection. Mice lacking the chemokine receptor CCR1 have defects in neutrophil trafficking and proliferation. In the present study, we tested the susceptibility of CCR1 knockout mice to infection with the obligate intracellular protozoan parasite Toxoplasma gondii. In comparison with parental wild-type mice, CCR1(-/-) mice exhibited dramatically increased mortality to T. gondii in association with an increased tissue parasite load. No differences were observed in Ag-specific T cell proliferation or in cytokine responses between mutant and wild-type mice. However, the influx of PMNs to the peripheral blood and to the liver were reduced in CCR1(-/-) mice during early infection. Our results suggest that CCR1-dependent migration of neutrophils to the blood and tissues may have a significant impact in controlling parasite replication.
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MESH Headings
- Animals
- Chemokines, CC/metabolism
- Down-Regulation/genetics
- Down-Regulation/immunology
- Female
- Genetic Predisposition to Disease
- Hepatocytes/parasitology
- Hepatocytes/pathology
- Humans
- Immune Tolerance/genetics
- Immunity, Cellular/genetics
- Leukocyte Count
- Liver/parasitology
- Liver/pathology
- Mice
- Mice, Knockout
- Necrosis
- Neutrophils/pathology
- Nitric Oxide/physiology
- Organ Specificity/genetics
- Organ Specificity/immunology
- Receptors, CCR1
- Receptors, Chemokine/deficiency
- Receptors, Chemokine/genetics
- Toxoplasma/immunology
- Toxoplasmosis, Animal/genetics
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/mortality
- Toxoplasmosis, Animal/parasitology
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114
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Wattanasuwan N, Khan IA, Mehta NJ, Arora P, Singh N, Vasavada BC, Sacchi TJ. Acute ventricular rate control in atrial fibrillation: IV combination of diltiazem and digoxin vs. IV diltiazem alone. Chest 2001; 119:502-6. [PMID: 11171729 DOI: 10.1378/chest.119.2.502] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
OBJECTIVE To analyze the efficacy of an IV combination of diltiazem and digoxin vs IV diltiazem alone for acute ventricular rate control in patients with atrial fibrillation. DESIGN Prospective, randomized, open-label study. PATIENTS AND METHODS Fifty-two patients with atrial fibrillation and uncontrolled ventricular rates were randomized to receive either an IV combination of diltiazem and digoxin or IV diltiazem alone and were observed for 12 h. The successful rate control was defined as a ventricular rate < 100 beats per minute (bpm) persisting for 1 h or conversion to sinus rhythm. The loss of rate control was defined as an increase in the ventricular rate to > 100 bpm persistently for > 30 min or rebound to atrial fibrillation. RESULTS In both treatment arms (n = 26 each), all patients achieved successful and comparable ventricular rate control at 12 h. The mean (+/- SD) time taken to achieve successful rate control was shorter in the combination arm (15 +/- 16 vs. 22 +/- 22 min). Six patients in the combination arm and 11 in the diltiazem-alone arm experienced episodes of loss of rate control. This loss in the combination arm was less than that in the diltiazem-alone arm (14 vs 39 episodes; p = 0.05). The loss of rate control per patient in the combination arm was also less than that in the diltiazem-alone arm (2.0 +/- 1.0 vs. 3.5 +/- 1.9 episodes per patient; p = 0.04). CONCLUSIONS This study demonstrates that in patients with atrial fibrillation who have a rapid ventricular response, the IV combination of diltiazem and digoxin results in a more efficacious ventricular rate control with fewer fluctuations than that achieved by therapy with IV diltiazem alone.
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115
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Khan IA. Ebstein's anomaly of the tricuspid valve with associated mitral valve prolapse. Tex Heart Inst J 2001; 28:72. [PMID: 11330750 PMCID: PMC101139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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116
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Bedir E, Toyang NJ, Khan IA, Walker LA, Clark AM. A new dammarane-type triterpene glycoside from Polyscias fulva. JOURNAL OF NATURAL PRODUCTS 2001; 64:95-7. [PMID: 11170676 DOI: 10.1021/np0003589] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new dammarane-type triterpene glycoside, polysciasoside A (1), and three known compounds have been isolated from the leaves of Polyscias fulva. The structure of the new compound was established as 12-oxo-3beta,16beta,20(S)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside.
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117
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Khan IA. Twelve-lead electrocardiogram of torsades de pointes. Tex Heart Inst J 2001; 28:69. [PMID: 11330748 PMCID: PMC101137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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118
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Gowda RM, Khan IA, Sacchi TJ, Vasavada BC. Scleroderma pericardial disease presented with a large pericardial effusion--a case report. Angiology 2001; 52:59-62. [PMID: 11205932 DOI: 10.1177/000331970105200108] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Scleroderma pericardial disease is usually silent and benign. The incidence of pericardial involvement in scleroderma is about 50% according to autopsy results, but symptomatic pericarditis manifests in about 16% of patients with diffuse scleroderma and in about 30% of patients with limited scleroderma. The clinically evident pericardial effusion is rare in scleroderma, although it can be detected in about 41% of patients with echocardiography. In majority of the patients, the pericardial effusion is small and not associated with symptoms. The pericardial effusion manifests usually after the manifestation of the other clinical and serologic features of scleroderma. A case of scleroderma is reported that presented with a large pericardial effusion, which antedated the other clinical and serologic features of scleroderma. The pericardial involvement in scleroderma is reviewed.
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119
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Siddiqui MA, Holmberg MJ, Khan IA. Spontaneous echo contrast in left atrial appendage during sinus rhythm. Tex Heart Inst J 2001; 28:322-3. [PMID: 11777163 PMCID: PMC101214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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120
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Bedir E, Calis I, Piacente S, Pizza C, Khan IA. A new flavonol glycoside from the aerial parts of Astragalus vulneraria. Chem Pharm Bull (Tokyo) 2000; 48:1994-5. [PMID: 11145157 DOI: 10.1248/cpb.48.1994] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new flavonol glycoside, isorhamnetin 3-O-beta-D-apiofuranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-galactopyranoside, and the known diglycoside, isorhamnetin 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside were isolated from the aerial parts of Astragalus vulneraria. Characterization of the two compounds was done by spectroscopic methods (1D and 2D NMR, and FAB-MS).
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121
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Abstract
The styryl alpha-pyrones, d-kawain (1) and d-methysticin (2) are two of the major kavalactone constituents of the anxiolvtic herb Piper methysticum, commonly known as kava. The use of fungal models to mimic the mammalian metabolism of 1 resulted in the production of 4'-hydroxykawain (1a) from the culture broth of Cunninghamella elegans (ATCC 9245), the same metabolite identified in rat urine. The fungus Torulopsis petrophilum (ATCC 20225) biotransformed 2 to 3'-hydroxy-4'-methoxykawain (2c) which is analogous, but not identical, to a known rat metabolite of methysticin.
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122
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Bedir E, Khan IA. New steroidal glycosides from the fruits of Tribulus terrestris. JOURNAL OF NATURAL PRODUCTS 2000; 63:1699-1701. [PMID: 11141122 DOI: 10.1021/np000353b] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three new steroidal saponins (1-3) were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic methods (IR, HRESIMS, 1D- and 2D-NMR) as 26-O-beta-D-glucopyranosyl-(25S)-5beta-furost-20(22)-en-3bet a, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl- (1-->4)]-beta-D-glucopyranoside (1), 26-O-beta-D-glucopyranosyl-(25S)-5beta-furost-20(22)-en-3bet a, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1 -->4)]-beta-D-galactopyranoside (2), and 25(S)-5beta-spirostan-3beta-ol-3-O-alpha-L-rhamnopyranosyl-( 1-->2)-[b eta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (3). Compound 3 showed cytotoxicity against a human malignant melanoma cell line (SK-MEL).
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123
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Khan IA, Shaw IS. Pseudo myocardial infarction and pseudo ventricular hypertrophy ECG patterns in Wolff-Parkinson-White syndrome. Am J Emerg Med 2000; 18:802-6. [PMID: 11103732 DOI: 10.1053/ajem.2000.18024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In Wolff-Parkinson-White (WPW) syndrome, the ventricles are pre-excited through an accessory conduction pathway, bundle of Kent, which directly connects atria with ventricles bypassing the atrioventricular node. The altered sequence of ventricular activation secondary to presence of the bundle of Kent may cause pseudo myocardial infarction and pseudo ventricular hypertrophy patterns on electrocardiogram. The morphology of these pseudo electrocardiographic patterns depends on the anatomical location of the bundle of Kent around the circumference of the atrioventricular ring. Electrocardiograms of the WPW syndrome displaying morphology of different pseudo patterns are presented and the mechanisms causing pseudo patterns are reviewed.
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124
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Khan IA, Shaw IS. Pseudo ventricular hypertrophy and pseudo myocardial infarction in Wolff-Parkinson-White syndrome. Am J Emerg Med 2000; 18:807-9. [PMID: 11103733 DOI: 10.1053/ajem.2000.18049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In Wolff-Parkinson-White syndrome, the sequence of ventricular activation is altered and depending on the anatomic site of the accessory conduction pathway may result in pseudo ventricular hypertrophy and pseudo myocardial infarction patterns on electrocardiogram. The right-sided accessory pathway may direct the depolarization vector towards left amplifying R-wave amplitude in left-sided limb-leads simulating left ventricular hypertrophy. The left-sided accessory pathways may give rise to prominent R-waves in right precordial leads simulating right ventricular hypertrophy. The right lateral accessory pathways may simulate anterior infarction because of prominent Q-waves in right precordial leads. The left lateral accessory pathways directing depolarization vector towards right may cause Q-waves in lateral limb-leads simulating high lateral myocardial infarction. In posteroseptal accessory pathway, the ventricular depolarization vector is directed superiorily giving rise to prominent Q-waves in inferior limb leads simulating inferior myocardial infarction. Therefore, ventricular hypertrophy and myocardial infarction should not be diagnosed from the electrocardiograms of Wolff-Parkinson-White syndrome.
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125
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Moretto M, Casciotti L, Durell B, Khan IA. Lack of CD4(+) T cells does not affect induction of CD8(+) T-cell immunity against Encephalitozoon cuniculi infection. Infect Immun 2000; 68:6223-32. [PMID: 11035729 PMCID: PMC97703 DOI: 10.1128/iai.68.11.6223-6232.2000] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cell-mediated immunity has been reported to play an important role in defense against Encephalitozoon cuniculi infection. Previous studies from our laboratory have underlined the importance of cytotoxic CD8(+) T lymphocytes (CTL) in survival of mice infected with E. cuniculi. In the present study, immune response against E. cuniculi infection in CD4(+) T-cell-deficient mice was evaluated. Similar to resistant wild-type animals, CD4(-/-) mice were able to resolve E. cuniculi infection even at a very high challenge dose (5 x 10(7) spores/mouse). Tissues from infected CD4(-/-) mice did not exhibit higher parasite loads in comparison to the parental wild-type mice. Conversely, at day 21 postinfection, susceptible CD8(-/-) mice had 10(14) times more parasites in the liver compared to control wild-type mice. Induction of the CD8(+) T-cell response in CD4(-/-) mice against E. cuniculi infection was studied. Interestingly, a normal antigen-specific CD8(+) T-cell response to E. cuniculi infection was observed in CD4(-/-) mice (precursor proliferation frequency, 1/2.5 x 10(4) versus 1/10(4) in wild-type controls). Lack of CD4(+) T cells did not alter the magnitude of the antigen-specific CTL response (precursor CTL frequency; 1/1.4 x 10(4) in CD4(-/-) mice versus 1/3 x 10(4) in control mice). Adoptive transfer of immune CD8(+) T cells from both CD4(-/-) and wild-type animals prevented the mortality in CD8(-/-) mice. E. cuniculi infection thus offers an example of an intracellular parasitic infection where CD8(+) T-cell immunity can be induced in the absence of CD4(+) T cells.
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