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Khan AA, Shah SW, Alam A, Butt AK, Shafqat F, Castell DO. Massively dilated esophagus in achalasia: response to pneumatic balloon dilation. Am J Gastroenterol 1999; 94:2363-6. [PMID: 10483992 DOI: 10.1111/j.1572-0241.1999.01358.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Pneumatic balloon dilation is considered by many to be the treatment of choice for achalasia of the esophagus. Patients with untreated, long standing achalasia may develop massively dilated esophagi, sometimes difficult to dilate with a pneumatic balloon and, rarely, may require esophagectomy. We present our experience with nine such patients out of 110 who underwent pneumatic dilation. METHODS Of 110 patients treated for achalasia by pneumatic balloon dilation, from January 1989 until December 1996, nine patients had massively dilated esophagi with transverse diameter >7 cm. Results of these patients are presented with pre- and postdilation symptom scores and barium esophagograms. This study was conducted at the Department of Gastroenterology, Shaikh Zayed Postgraduate Medical Institute, Lahore, Pakistan. A Microvasive Rigiflex 35 mm (Boston Scientific, Watertown, MA) pneumatic balloon was used for dilation. RESULTS Although it is often tedious to perform pneumatic dilation in massively dilated esophagus, it was possible to dilate adequately, in all nine cases without complications, with good symptomatic improvement at 12-month follow-up. CONCLUSIONS We recommend pneumatic balloon dilation in achalasia with massively dilated esophagus as a first line treatment, the failure of which requires surgical intervention.
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Khan AA, Slifer TR, Araujo FG, Remington JS. Quinupristin-dalfopristin is active against Toxoplasma gondii. Antimicrob Agents Chemother 1999; 43:2043-5. [PMID: 10428933 PMCID: PMC89411 DOI: 10.1128/aac.43.8.2043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Synercid and each of its components (quinupristin and dalfopristin) were examined for their activities against Toxoplasma gondii. In vitro, intracellular replication of tachyzoites was inhibited by synercid and each of its two components. The 50% inhibitory concentrations of synercid, quinupristin, and dalfopristin were 1.6, 2.7, and 6.3 microg/ml, respectively. Thus, synercid was markedly more active than its components. Treatment of acutely infected mice with 100 or 200 mg of synercid per kg of body weight per day administered intraperitoneally for 10 days resulted in survival of 50% (P = 0.0002) and 100% (P < 0.0001) of infected mice, respectively, whereas all control mice died by day 18. In contrast, treatment with 200 mg of either quinupristin and dalfopristin per kg per day alone resulted in only 20% survival; treatment with 50 mg of either drug per kg per day resulted only in the prolongation of time to death. These results suggest that synercid may be useful for treatment of toxoplasmosis in humans.
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Nawaz MS, Khan AA, Khan SA, Paine DD, Pothuluri JV, Cerniglia CE. Biochemical and molecular characterization of erthromycin-resistant avian Staphylococcus spp. isolated from chickens. Poult Sci 1999; 78:1191-7. [PMID: 10472846 DOI: 10.1093/ps/78.8.1191] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The epidemiology of the two common erythromycin-resistant methylase (erm) genes ermC and ermA was analyzed in 12 coagulase-negative Staphylococcus spp. and 34 coagulase-positive Staphylococcus spp. isolated from chicken. Southern hybridization indicated that only 2 of the 12 coagulase-negative Staphylococcus spp. strains contained the ermC gene on the plasmid; 1 strain of Staphylococcus xylosus harbored the ermC gene on a 2.5-kb plasmid, and 1 strain of Staphylococcus cohnii harbored the gene on a 4.0-kb plasmid. Twelve of the 34 strains of Staphylococcus aureus contained the ermC gene. Eleven of these strains had the ermC gene on a 2.5-kb plasmid, and 1 strain had the gene on a 4.0-kb plasmid. Ten of the 12 coagulase-negative Staphylococcus spp. and 22 of the 34 coagulase-positive Staphylococcus spp. harbored the ermA gene exclusively on the chromosome. Two different ermA EcoRI restriction fragment length polymorphisms (RFLP) were identified. A majority of the isolates was found to have two chromosomal inserts (8.0- and 6.2-kb EcoRI fragments) of ermA. One strain of S. aureus had different chromosomal inserts (6.4- and 5.8-kb EcoRI fragments) of ermA. Our results indicate that either the ermC or ermA gene, homologous to those described in human isolates, was present in all avian Staphylococcus spp. and that ermA was the predominant gene in coagulase-negative and coagulase-positive avian Staphylococcus spp. The size and copy numbers of the ermA gene were different from its human counterpart.
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Abstract
Nikolsky's sign is a useful clinical sign in patients with active pemphigus. It does not however, indicate the level of split in the skin, and is seldom present in partially-treated patients. The purpose of this study was two fold: (i) to document the microscopic or subclinical counterpart of clinical Nikolsky's sign; and (ii) to improve the diagnostic yield of routine histopathology in pemphigus patients in whom the lesions are infected/old and are therefore not useful for histopathology, and when intact blisters are not present; this is particularly useful for institutions in which immunofluorescence facilities are not available. Pemphigus patients were allocated to one of two groups. Group A patients (n = 23) were subjected to manual tangential pressure over the perilesional skin before a biopsy specimen was taken from that site; group B patients (n = 14) were subjected to a biopsy without the tangential pressure technique. Group C consisted of 37 healthy volunteers who were subjected to the tangential pressure technique before a biopsy. Histopathological changes of pemphigus vulgaris or foliaceus were present in 73.9% patients in group A, 28.6% in group B and none in the control group C. Tangential pressure as described below can produce microscopic changes in the epidermis which are diagnostic of pemphigus. These changes are produced at the suprabasal level in pemphigus vulgaris and intraepidermally in pemphigus foliaceus. This technique is of value in those parts of the world where immunofluorescence facilities are not readily available.
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Butt AK, Khan AA, Bedi R. Helicobacter pylori in dental plaque of Pakistanis. JOURNAL OF THE INTERNATIONAL ACADEMY OF PERIODONTOLOGY 1999; 1:78-82. [PMID: 10833287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Helicobacter pylori is now generally accepted to play a key role in acid related and neoplastic pathology of gastroduodenal diseases. Recent reports have concluded that dental plaque is not an important reservoir for Helicobacter pylori, however, these studies did not consider the ethnic background of their subjects nor the amounts of dental plaque present. The aim of this study was to explore the association of Helicobacter pylori dental plaque colonisation in 125 males and 53 females (group I) attending a dental clinic in Pakistan. A simultaneous sample of 30 healthy volunteers with good orodental hygiene consisting of 17 males and 13 females was included as a control group (group II). Six dental plaque specimens were obtained from each subject with a sickle scaler; two were inoculated into CLO test gel and the remaining four were used to prepare cytology slides stained with Giemsa's stain. CLO test was positive in all specimens from group I, while cytology for Helicobacter pylori was positive in 173 cases in this group. One hundred and forty two cases had heavy plaque deposits and all of them were positive on cytology. In group II CLO test was positive in 20 and dental plaque cytology was positive in 7 cases. In conclusion, it is important that future studies into the prevalence of Helicobacter pylori in the oral cavity should take into account the levels of oral cleanliness and the ethnic background of the subjects.
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Khan AA, Araujo FG, Brighty KE, Gootz TD, Remington JS. Anti-Toxoplasma gondii activities and structure-activity relationships of novel fluoroquinolones related to trovafloxacin. Antimicrob Agents Chemother 1999; 43:1783-7. [PMID: 10390245 PMCID: PMC89366 DOI: 10.1128/aac.43.7.1783] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eleven novel fluoroquinolones closely related to trovafloxacin were evaluated for their in vitro activity against Toxoplasma gondii, and their structure-activity relationships were examined. The 50% inhibitory concentration (IC50) of trovafloxacin against T. gondii was 2.93 microM; the IC50 of the 11 analogs ranged from 0.53 to 14. 09 microM. Six analogs had IC50s lower than that of trovafloxacin. Examination of the structure-activity relationships of the compounds revealed that addition of a -CH3 at C-5 of the 1,8-naphthyridone ring, at C-2 of the azabicyclohexane ring, or on the -NH2 at the 6 position of the azabicyclohexane ring resulted in a four- to sixfold increase in activity. Moreover, replacement of 2,4-difluorophenyl by cyclopropyl at N-1 of the 1,8-naphthyridone ring increased activity twofold, and moving the -NH2 one atom further away from the azabicyclohexane ring decreased activity. There was no difference between the naphthyridone and quinolone analogs. These results indicate that structure-activity studies of compounds related to drugs active against T. gondii may be useful in producing compounds with more potent activities against the parasite.
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Khan SA, Nawaz MS, Khan AA, Cerniglia CE. Direct in-gel hybridization of digoxigenin-labelled non-radioactive probes. Mol Cell Probes 1999; 13:233-7. [PMID: 10369749 DOI: 10.1006/mcpr.1999.0241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An improved, simple, cost-effective and non-radioactive procedure for in-gel hybridization is described for the detection of signal in dried agarose gels. Large and small digoxigenin-labelled DNA and oligonucleotide probes hybridized efficiently and specifically with the complementary DNA sequences in the gel. The signal-to-noise ratios for the gels dried at 55 degrees C at 1 atmospheric pressure were 3-3.5-fold higher than the gels dried at 25 degrees C under vacuum. The method shows an increased sensitivity over currently available non-radioactive methods for in-gel hybridization. A single copy of a gene insert could be detected by the use of this procedure.
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Khan AA, Nawaz MS, Khan SA, Cerniglia CE. Identification of Aeromonas trota (hybridization group 13) by amplification of the aerolysin gene using polymerase chain reaction. Mol Cell Probes 1999; 13:93-8. [PMID: 10208799 DOI: 10.1006/mcpr.1999.0222] [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: 11/22/2022]
Abstract
Aeromonas trota is recognized as an important enteropathogen, and its haemolysin (aerolysin) is purported to be one of the virulence factors. Rapid detection and identification of A. trota is important for early and specific diagnosis of the infectious diseases that it causes. Synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) technique to amplify a species-specific sequence of the aerA gene, which encodes the aerolysin of A. trota. A DNA fragment of 622 bp was amplified from both lysed cells and isolated DNA from A. trota. The identity of the amplified 622 bp fragment was confirmed by digestion with BamH I restriction endonuclease, which produced the predicted 557 and 65 bp fragments. The lower limit for detection of the aerA gene by PCR amplification was 10 pg of total DNA or 10-15 cells ml-1. Primer specificity for A. trota was determined by the PCR assay with cells of 55 strains of Aeromonas sppincluding all of the 14 currently recognized DNA hybridization groups. A strain of Aeromonas enteropelogenes that had been reclassified as A. trota was also PCR positive. The method described here can be used to detect aerolysin-producing A. trota (hybridization group 13) strains from environmental and clinical samples without the use of selective media or additional biochemical tests.
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Khan AA, Lambert LH, Remington JS, Araujo FG. Recombinant bactericidal/permeability-increasing protein (rBPI21) in combination with sulfadiazine is active against Toxoplasma gondii. Antimicrob Agents Chemother 1999; 43:758-62. [PMID: 10103177 PMCID: PMC89203 DOI: 10.1128/aac.43.4.758] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activity of recombinant bactericidal/permeability-increasing protein (rBPI21), alone or in combination with sulfadiazine, on the intracellular replication of Toxoplasma gondii was assessed in vitro and in mice with acute toxoplasmosis. rBPI21 markedly inhibited the intracellular growth of T. gondii in human foreskin fibroblasts (HFFs). Following 72 h of exposure, the 50% inhibitory concentration of rBPI21 for T. gondii was 2.6 micrograms/ml, whereas only slight cytotoxicity for HFF cells was observed at the concentrations tested. Subsequent mathematical analyses revealed that the combination of rBPI21 with sulfadiazine yielded slight to moderate synergistic effects against T. gondii in vitro. Infection of mice orally with C56 cysts or intraperitoneally (i.p.) with RH tachyzoites resulted in 100% mortality, whereas prolongation of the time to death or significant survival (P = 0.002) was noted for those animals treated with 5 to 20 mg of rBPI21 per kg of body weight per day. Treatment with rBPI21 in combination with sulfadiazine resulted in significant (P = 0.0001) survival of mice infected i.p. with tachyzoites but not of mice infected orally with T. gondii cysts. These results indicate that rBPI21 is active in vitro and in vivo against T. gondii and that its activity is significantly enhanced when it is used in combination with sulfadiazine. To our knowledge, this is the first report of the activity of rBPI21 against a protozoan parasite.
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Khan AA, Slifer TR, Araujo FG, Remington JS. Effect of clarithromycin and azithromycin on production of cytokines by human monocytes. Int J Antimicrob Agents 1999; 11:121-32. [PMID: 10221415 DOI: 10.1016/s0924-8579(98)00091-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We examined the in vitro effect of clarithromycin and azithromycin on cytokine production by LPS and Pansorbin stimulated human monocytes. At concentrations that are physiologically achievable, both antibiotics affected in vitro production of IL-1alpha, IL-1beta, IL-6, IL-10, GM-CSF and TNF-alpha to varying degrees. Of those individuals in whom a significant increase or decrease in cytokine production was noted, clarithromycin treatment resulted in a significant suppression of production of each cytokine in 71% and a significant increase in 29% of the individuals. Similar results were noted with azithromycin. The results with IL-6 and TNF-alpha in the clarithromycin studies were most striking. A significant decrease was noted in 60% of individuals for IL-6 and 86% for TNF-alpha. For azithromycin, the most interesting results were for IL-1alpha (decrease in 100% of individuals) and for TNF-alpha (decrease in 100% of individuals). These results show that both clarithromycin and azithromycin alter cytokine production in human monocytes and thus possess immunomodulatory activity.
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Wang RF, Khan AA, Cao WW, Cerniglia CE. Identification and sequencing of a cDNA encoding 6-phosphogluconate dehydrogenase from a fungus, Cunninghamella elegans and expression of the gene in Escherichia coli. FEMS Microbiol Lett 1998; 169:397-402. [PMID: 9868787 DOI: 10.1111/j.1574-6968.1998.tb13346.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The fungus, Cunninghamella elegans has been widely used in bioremediation and microbial models of mammalian studies in many laboratories. Using the polymerase chain reaction to randomly amplify the insert directly from the single non-blue plaques of a C. elegans cDNA library, then partly sequencing and comparing with GenBank sequences, we have identified a clone which contains C. elegans 6-phosphogluconate dehydrogenase gene. The polymerase chain reaction product was cloned into a plasmid, pGEM-T Easy vector for full insert DNA sequencing. The 6-phosphogluconate dehydrogenase gene (1458 bases) and the deduced protein sequence were determined from the insert DNA sequence. The gene was found by open reading frame analysis and confirmed by the alignment of the deduced protein sequence with other published 6-phosphogluconate dehydrogenase sequences. Several highly conserved regions were found for the 6-phosphogluconate dehydrogenase sequences. The 6-phosphogluconate dehydrogenase gene was subcloned and over-expressed in a plasmid-E. coli system (pQE30). The cell lysate of this clone has a very high 6-phosphogluconate dehydrogenase enzyme activity. Most of the recombinant protein in this system was formed as insoluble inclusion bodies, but soluble in high concentration of urea-buffer. Ni-NTA resin was used to purify the recombinant protein which showed 6-phosphogluconate dehydrogenase enzyme activity. The recombinant protein has a predicted molecular size correlating with that revealed by sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis. The C. elegans 6-phosphogluconate dehydrogenase was in a cluster with yeast' 6-phosphogluconate dehydrogenase in the phylogenetic tree. Bacterial 6-phosphogluconate dehydrogenase and higher organisms' 6-phosphogluconate dehydrogenase were found in different clusters.
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Nguyen AH, Khan AA, Chait A, Fallahnejad M. The wandering coronary stent. Case report. THE JOURNAL OF CARDIOVASCULAR SURGERY 1998; 39:807-9. [PMID: 9972904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Complications associated with coronary stent placement have decreased in recent years. One of the complications involved with this procedure is the possibility that the stent is stripped from the delivery catheter prior to deployment and is lost systemically. This paper reports a rare complication which resulted in vascular insufficiency necessitating surgical intervention.
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Butt AK, Khan AA, Alam A, Shah SW, Shafqat F, Naqvi AB. Predicting hospital mortality in cirrhotic patients: comparison of Child-Pugh and Acute Physiology, Age and Chronic Health Evaluation (APACHE III) scoring systems. Am J Gastroenterol 1998; 93:2469-75. [PMID: 9860411 DOI: 10.1111/j.1572-0241.1998.00706.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The severity of hepatic abnormalities and extent of dysfunction of other organ systems influences prognosis for cirrhosis. The Child-Pugh system has been used to classify cirrhotic patients into good, intermediate, or poor risk categories in evaluation and therapy. Disregard for cardiorespiratory, renal, electrolyte balance, and acid base status limits its predictive accuracy. We evaluated the accuracy of Acute Physiology and Chronic Health Evaluation (APACHE III) to predict short term hospital mortality in patients with liver cirrhosis. METHODS A total of 282 patients were prospectively enrolled. Child-Pugh and APACHE III scores were recorded on day 1 for each patient. RESULTS Mean age was 51.7+/-11.3 yr, with 65% men and 35% women; 57% presented with upper GI bleeding, 47% encephalopathy, 9% hepatorenal syndrome, and 7% hepatocellular carcinoma. Sixty-three patients (22%) died. Major causes of death were upper GI bleeding 38%, liver failure 21%, hepatorenal syndrome 19%, hepatocellular carcinoma 4%, and spontaneous bacterial peritonitis 6%. Child-Pugh and APACHE III scores for survivors (8.6+/-2.3 and 58.9+/-35.1) were lower than those for nonsurvivors (10.9+/-2.7 and 87.4+/-30.3) (p < 0.001). Using discriminant analysis, APACHE III correctly identified 75% of cases vs 67% of cases for Child-Pugh (p < 0.05). When information regarding ascites and prothrombin time was added to APACHE III, 81% of cases were correctly classified. CONCLUSION The APACHE III scoring system is superior to Child-Pugh for prognosticating short term survival of cirrhotic patients. Prognostic accuracy of APACHE III can be enhanced by incorporating information regarding ascites and prothrombin time prolongation.
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Araujo FG, Khan AA, Bryskier A, Remington JS. Use of ketolides in combination with other drugs to treat experimental toxoplasmosis. J Antimicrob Chemother 1998; 42:665-7. [PMID: 9848454 DOI: 10.1093/jac/42.5.665] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Because combination therapy is required to treat human toxoplasmosis, we examined combinations of the ketolides HMR 3004 and HMR 3647 with atovaquone, clindamycin or sulphadiazine in a murine model of toxoplasmosis. An oral dose of 50 mg/kg/day of HMR 3004 protected 30% of mice lethally infected with Toxoplasma gondii. The same dose protected 100% of infected mice when administered in combination with non-protective doses of atovaquone, clindamycin or sulphadiazine. Similar results were noted with 25 mg/kg/day of HMR 3647. These results demonstrate that these drug combinations are highly effective for treating toxoplasmosis in mice.
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Kendler D, Khan AA. Re: Use of cyclic etidronate and the prevention of non-vertebral fractures. BRITISH JOURNAL OF RHEUMATOLOGY 1998; 37:1253-4. [PMID: 9851285 DOI: 10.1093/rheumatology/37.11.1253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nawaz MS, Zhang D, Khan AA, Cerniglia CE. Isolation and characterization of Enterobacter cloacae capable of metabolizing asparagine. Appl Microbiol Biotechnol 1998; 50:568-72. [PMID: 9866175 DOI: 10.1007/s002530051336] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
A gram-negative, rod-shaped bacterium capable of utilizing L-asparagine as its sole source of carbon and nitrogen was isolated from soil and identified as Enterobacter cloacae. An intracellularly expressed L-asparaginase was detected and it deaminated L-asparagine to aspartic acid and ammonia. High-pressure liquid chromatography analysis of a cell-free asparaginase reaction mixture indicated that 2.8 mM L-asparagine was hydrolyzed to 2.2 and 2.8 mM aspartic acid and ammonia, respectively, within 20 min of incubation. High asparaginase activity was found in cells cultured on L-fructose, D-galactose, saccharose, or maltose, and in cells cultured on L-asparagine as the sole nitrogen source. The pH and temperature optimum of L-asparaginase was 8.5 and 37-42 degrees C, respectively. The half-life of the enzyme at 30 degrees C and 37 degrees C was 10 and 8 h, respectively.
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Khan AA, Nasr M, Araujo FG. Two 2-hydroxy-3-alkyl-1,4-naphthoquinones with in vitro and in vivo activities against Toxoplasma gondii. Antimicrob Agents Chemother 1998; 42:2284-9. [PMID: 9736550 PMCID: PMC105819 DOI: 10.1128/aac.42.9.2284] [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: 11/20/2022] Open
Abstract
Two 3-alkyl-substituted 2-hydroxy-1,4-naphthoquinones, NSC 113452 (NSC52) and NSC 113455 (NSC55), were evaluated for activity against Toxoplasma gondii in vitro and in murine models of acute toxoplasmosis. In vitro, both NSC52 and NSC55 significantly inhibited intracellular replication of T. gondii. In vivo, each compound was examined alone and in combination with other drugs currently used for treatment of human toxoplasmosis. Although none of the compounds protected mice against death when administered orally, both were significantly protective when administered intraperitoneally. In addition, a significant increase in survival was observed when suboptimal doses of each compound were used in combination with suboptimal doses of pyrimethamine or sulfadiazine. These results indicate that combinations of NSC52 or NSC55 with pyrimethamine or sulfadiazine have promising activity against T. gondii.
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Thompson PM, Moussai J, Zohoori S, Goldkorn A, Khan AA, Mega MS, Small GW, Cummings JL, Toga AW. Cortical variability and asymmetry in normal aging and Alzheimer's disease. Cereb Cortex 1998; 8:492-509. [PMID: 9758213 DOI: 10.1093/cercor/8.6.492] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The onset of Alzheimer's disease (AD) is accompanied by a complex and distributed pattern of neuroanatomic change, difficult to distinguish clinically from dynamic alterations in normal aging. Extreme variations in the sulcal patterns of the human cortex have made it difficult to identify diffuse and focal variations in cortical structure in neurodegenerative disease. We report the first comprehensive 3D statistical analysis of deep sulcal structure in vivo, in both normal aging and dementia. High-resolution 3D T1-weighted fast SPGR (spoiled GRASS) MRI volumes were acquired from 10 patients diagnosed with AD (NINCDS-ARDRA criteria; age: 71.9 +/- 10.7 years) and 10 normal subjects matched for age (72.9 +/- 5.6 years), gender, educational level and handedness. Scans were digitally transformed into Talairach stereotaxic space. To determine specific patterns of cortical variation in dementia patients, 3D average and probabilistic maps of primary deep sulci were developed for both normal and AD groups. Major sulci (including supracallosal, cingulate, marginal, parieto-occipital, anterior and posterior calcarine sulci, and Sylvian fissures) were modeled as complex systems of 3D surfaces using a multi-resolution parametric mesh approach. Variations and asymmetries in their extents, curvature, area and surface complexity were evaluated. Three-dimensional maps of anatomic variability, structural asymmetry and local atrophy indicated severe regionally selective fiber loss in AD. A midsagittal area loss of 24.5% at the corpus callosum's posterior midbody (P < 0.025) matched increases in structural variability in corresponding temporo-parietal projection areas. Confidence limits on 3D cortical variation, visualized in 3D, exhibited severe increases in AD from 2 to 4 mm at the callosum to a peak SD of 19.6 mm at the posterior left Sylvian fissure. Normal Sylvian fissure asymmetries (right higher than left; P < 0.0005), mapped for the first time in three dimensions, were accentuated in AD (P < 0.0002), and were greater in AD than in controls (P < 0.05). Severe AD-related increases in 3D variability and asymmetry may reflect disease-related disruption of the commissural system connecting bilateral temporal and parietal cortical zones, regions known to be at risk of early metabolic dysfunction, perfusion deficits and selective neuronal loss in AD.
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Shafqat F, Khan AA, Alam A, Butt K, Shah SW, Naqvi AB. Band ligation vs endoscopic sclerotherapy in esophageal varices: a prospective randomized comparison. J PAK MED ASSOC 1998; 48:192-6. [PMID: 10067020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
OBJECTIVE A prospective randomized trial was conducted to compare efficacy, safety and complications of band ligation (BL) with sclerotherapy (Scl). METHODS Patients with esophageal variceal bleeding were randomized into two study groups. BL (group A) was done in 28 patients whereas 30 patients (group B) had Scl. After initial treatment, follow-up sessions were repeated by the same method every two weeks till obliteration or reduction to grade 1. Subsequent sessions of endoscopy were done every three months, same procedure was repeated for recurrence of varices and for any episode of rebleeding. RESULTS Initial control of bleeding by Scl was achieved in 22 of 28 patients (78%) and in 23 of 24 patients (96%) with BL. Eradication of varices was significantly better achieved in BL group, with less treatment sessions required in Group A as compared with group B 2 +/- 1.2 vs 5 +/- 2.5, P < 0.001). Major complications (3% vs 16%, P < 0.05) as well as mortality (11% vs 21%, P > 0.05) was higher in group B. CONCLUSION Band ligation was more effective mode of treatment and was associated with lesser early mortality and complications as compared with sclerotherapy.
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Khan AA, Kim E, Cerniglia CE. Molecular cloning, nucleotide sequence, and expression in Escherichia coli of a hemolytic toxin (aerolysin) gene from Aeromonas trota. Appl Environ Microbiol 1998; 64:2473-8. [PMID: 9647817 PMCID: PMC106413 DOI: 10.1128/aem.64.7.2473-2478.1998] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/1998] [Accepted: 04/16/1998] [Indexed: 02/08/2023] Open
Abstract
Aeromonas trota AK2, which was derived from ATCC 49659 and produces the extracellular pore-forming hemolytic toxin aerolysin, was mutagenized with the transposon mini-Tn5Km1 to generate a hemolysin-deficient mutant, designated strain AK253. Southern blotting data indicated that an 8.7-kb NotI fragment of the genomic DNA of strain AK253 contained the kanamycin resistance gene of mini-Tn5Km1. The 8.7-kb NotI DNA fragment was cloned into the vector pGEM5Zf(-) by selecting for kanamycin resistance, and the resultant clone, pAK71, showed aerolysin activity in Escherichia coli JM109. The nucleotide sequence of the aerA gene, located on the 1.8-kb ApaI-EcoRI fragment, was determined to consist of 1,479 bp and to have an ATG initiation codon and a TAA termination codon. An in vitro coupled transcription-translation analysis of the 1.8-kb region suggested that the aerA gene codes for a 54-kDa protein, in agreement with nucleotide sequence data. The deduced amino acid sequence of the aerA gene product of A. trota exhibited 99% homology with the amino acid sequence of the aerA product of Aeromonas sobria AB3 and 57% homology with the amino acid sequences of the products of the aerA genes of Aeromonas salmonicida 17-2 and A. sobria 33.
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Raja KM, Khan AA, Hameed A, Rahman SB. Unusual clinical variants of cutaneous leishmaniasis in Pakistan. Br J Dermatol 1998; 139:111-3. [PMID: 9764160 DOI: 10.1046/j.1365-2133.1998.02325.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cutaneous leishmaniasis is endemic in the Baluchistan province of Pakistan and poses a great risk to non-immune visitors to the area. The wide spectrum of clinical variants of this common disease is at times a diagnostic challenge. A total of 1709 patients with cutaneous leishmaniasis were recorded over a 1-year period. In 37 (2%) patients the lesions were very unusual, and therefore worth reporting. These included acute paronychial, chancriform, annular, palmoplantar, zosteriform and erysipeloid forms. The zosteriform and erysipeloid forms have rarely been reported previously, but to the best of our knowledge, acute paronychial, chancriform, annular and palmoplantar lesions are being reported for the first time. The morphologically unusual lesions may be attributed to an altered host response or involvement of an atypical strain of parasite in these lesions.
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Khan AA, Shah SW, Khan MA, Alam A, Butt AK, Shafqat F. Hiatal hernia in achalasia. J PAK MED ASSOC 1998; 48:196-7. [PMID: 10067021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Barium esophagograms of 89 patients out of 110 with manometrically proven achalasia were reviewed. Only four (4.4%) patients showed association of hiatal hernia, indicative of its rare occurrence. Presence of hiatal hernia, is said to have less likelihood of associated achalasia but this association does exist as per our report and that of others.
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Khan AA, Shah SW, Alam A, Butt AK, Shafqat F, Castell DO. Pneumatic balloon dilation in achalasia: a prospective comparison of balloon distention time. Am J Gastroenterol 1998; 93:1064-7. [PMID: 9672331 DOI: 10.1111/j.1572-0241.1998.00330.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Duration of Inflation in pneumatic balloon dilatation as treatment of achalasia has been variable ranging from 15 s to 6 min. A 60 s duration appears to be most often used. We compared the efficacy of dilation of achalasia with either 6- or 60-s inflation duration using a Rigiflex dilator of 3.0 cm diameter. METHODS Eighty-one consecutive patients were prospectively studied in a randomized fashion, 41 in the 60-s group (A) and 40 patients in the 6-s group (B). Mean age of group A was 43 +/- 16.2 yr and of group B was 40 +/- 16.4 yr. Symptoms of dysphagia, chest pain, heartburn, regurgitation, and night cough were evaluated at basal (before dilation), 1- and 6-month intervals after dilation in both groups. Barium swallow was done to assess esophageal emptying 1 wk before dilation and 5 min postdilation in both groups. RESULTS Significant and sustained improvement was seen for all symptoms in both groups. In addition, the degree of improvement in symptom scores between the two groups was similar. Barium esophagram in both groups at basal and immediately postdilation showed significant improvement in barium emptying but there was no significant difference between the two groups, indicative of equal efficacy in both distention times. Two patients needed repeat dilatation in group A and one in group B, with one drop out from group A, who was lost to follow-up, and was excluded from the analysis. No perforation occurred. CONCLUSION Short duration of pneumatic balloon dilatation (6-s) is as effective as longer duration (60-s) in treatment of achalasia.
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Butt AK, Khan AA, Alam A, Ahmad S, Shah SW, Shafqat F, Naqvi AB. Hepatocellular carcinoma: analysis of 76 cases. J PAK MED ASSOC 1998; 48:197-201. [PMID: 10067022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Hepatocellular carcinoma is one of the most common malignancies world wide. We present data on 76 patients admitted to the Shaikh Zayed Hospital. Mean age was 52.2 +/- 11.3 years. Eighty six percent were males and 14% females. Eighty-six percent patients had underlying cirrhosis documented on ultrasound examination. Seventy-five percent were positive for anti HCV, 10% for HBsAg positive, 10% for both HBsAg and anti HCV and 5% cases had negative viral serology. Main clinical features were abdominal pain, weight loss, jaundice, hepatomegaly and ascites. Forty-three percent patients were Child-Pugh class A, 30% class B and 13% class C and 14% were non cirrhotic. Mean alfa fetoprotein levels were 142 +/- 155 ng/ml (range 2.7 to 1470). Diagnosis of hepatocellular carcinoma was established in 60 patients by fine needle aspiration biopsy under ultrasound guidance. Two patients died after biopsy due to uncontrollable bleeding. Fifty-four percent patients had a solitary lesion and 46% had multifocal or diffuse lesions. The average size of lesion was 7.8 x 8.1 cm. Twenty-two patients received intralesional alcohol injection. Fifty-four percent of these with a tumor size greater than 8 cm died during follow up. The major cause of death was liver failure in 8 patients and fatal bleeding occurred in 4 patients. Hepatocellular carcinoma has a high prevalence in middle aged males with a strong association with anti HCV positive cirrhosis. Patients with a tumour size greater than 8 cm have a poor response to intralesional alcohol injection.
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Khan AA, Slifer TR, Remington JS. Effect of trovafloxacin on production of cytokines by human monocytes. Antimicrob Agents Chemother 1998; 42:1713-7. [PMID: 9661009 PMCID: PMC105671 DOI: 10.1128/aac.42.7.1713] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/1997] [Accepted: 05/06/1998] [Indexed: 02/08/2023] Open
Abstract
Antibiotics have previously been shown to have immunomodulatory effects. We examined the effect of the broad-spectrum fluoroquinoline antibiotic trovafloxacin on cytokine synthesis by monocytes obtained from healthy human volunteers and stimulated with either lipopolysaccharide or gram-positive cells (heat-killed Staphylococcus aureus [Pansorbin]). Trovafloxacin levels achievable in humans suppressed in vitro synthesis of each of the cytokines analyzed, viz., interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6, IL-10, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor alpha. This effect was not due to direct effects of the drug on cellular viability; at these concentrations, trovafloxacin did not have demonstrable cytotoxicity for the monocytes, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Although similar patterns of suppression of cytokine synthesis were observed in samples obtained from the same volunteers on different days, there were significant day-to-day variations. These results reveal that trovafloxacin possesses significant immunomodulatory activity in vitro and suggest that suppression of acute-phase inflammatory responses may occur in vivo, elicited through trovafloxacin's effect on cytokine synthesis by human monocytes.
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