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Biomedical subjects

A H Shah

Publications and source records attributed to A H Shah.

At least 19 recordsLinked to original sources
PubMed2006

The role of mental rotation and memory scanning on the performance of laparoscopic skills: a study on the effect of camera rotational angle.

OBJECTIVE: The rotational angle of the laparoscopic image relative to the true horizon has an unknown influence on performance in laparoscopic procedures. This study evaluates the effect of increasing rotational angle on surgical performance. METHODS: Surgical residents (group 1) (n = 6) and attending surgeons (group 2) (n = 4) were tested on two laparoscopic skills. The tasks consisted of passing a suture through an aperture, and laparoscopic knot tying. These tasks were assessed at 15 degrees intervals between 0 degrees and 90 degrees , on three consecutive repetitions. The participant's performance was evaluated based on the time required to complete the tasks and number of errors incurred. RESULTS: There was an increasing deterioration in suturing performance as the degree of image rotation was increased. Participants showed a statistically significant 20-120% progressive increase in time to completion of the tasks (p = 0.004), with error rates increasing from 10% to 30% (p = 0.04) as the angle increased from 0 degrees to 90 degrees. Knot-tying performance similarly showed a decrease in performance that was evident in the less experienced surgeons (p = 0.02) but with no obvious effect on the advanced laparoscopic surgeons. CONCLUSIONS: When evaluated independently and as a group, both novice and experienced laparoscopic surgeons showed significant prolongation to completion of suturing tasks with increased errors as the rotational angle increased. The knot-tying task shows that experienced surgeons may be able to overcome rotational effects to some extent. This is consistent with results from cognitive neuroscience research evaluating the processing of directional information in spatial motor tasks. It appears that these tasks utilize the time-consuming processes of mental rotation and memory scanning. Optimal performance during laparoscopic procedures requires that the rotation of the camera, and thus the image, be kept to a minimum to maintain a stable horizon. New technology that corrects the rotational angle may benefit the surgeon, decrease operating time, and help to prevent adverse outcomes.

Clinical Competence↗
PubMed2004

Kohl (surma): a toxic traditional eye cosmetic study in Saudi Arabia.

The use of kohl (surma) as eyeliner is a popular practice in Saudi Arabia and people firmly believe that it is safe to use. A total of 107 kohl samples (branded and unbranded) were collected from different regions of Saudi Arabia, and analysed for the presence of lead. In addition, aluminium and antimony levels were also determined. Lead levels up to 53% were detected in some kohl preparations, and some samples were found to contain camphor and menthol. The blood analyses of regular kohl users revealed a high lead concentration and relatively low haemoglobin levels. Due to the health risk, an official public awareness campaign is suggested to encourage the use of lead-free kohl.

Aluminum↗
PubMed2002

Elastic guided waves in a layered plate with rectangular cross section.

Guided waves in a layered elastic plate of rectangular cross section (finite width and thickness) has been studied in this paper. A semianalytical finite element method in which the deformation of the cross section is modeled by two-dimensional finite elements and analytical representation of propagating waves along the length of the plate has been used. The method is applicable to arbitrary number of layers and general anisotropic material properties of each layer, and is similar to the stiffness method used earlier to study guided waves in a laminated composite plate of infinite width. Numerical results showing the effect of varying the width of the plate on the dispersion of guided waves are presented and are compared with those for an infinite plate. In addition, effect of thin anisotropic coating or interface layers on the guided waves is investigated.

Elasticity↗
PubMed2001

Omeprazole as adjuvant therapy to endoscopic combination injection sclerotherapy for treating bleeding peptic ulcer.

BACKGROUND: Therapeutic endoscopy has provided a new means of treating bleeding peptic ulcers. Additional medical therapy may enhance the therapeutic benefit. Hemostasis is highly pH dependent and is severely impaired at low pH. Proton pump inhibitors, by achieving a significantly higher inhibition of gastric acidity, may improve the therapeutic outcomes after endoscopic treatment of ulcers. PATIENT AND METHODS: We enrolled 166 patients with hemorrhage from duodenal, gastric, or stomal ulcers and signs of recent hemorrhage, as confirmed by endoscopy. Twenty-six patients had ulcers with an arterial spurt, 41 patients had active ooze, 37 had a visible vessel, and 62 patients had an adherent clot. All patients received endoscopic injection sclerotherapy using 1:10,000 adrenaline and 1% polidocanol and were randomly assigned to receive omeprazole (40 mg orally) every 12 hours for 5 days or an identical-looking placebo. The outcome measures used were recurrent bleeding, surgery, blood transfusion, and hospital stay. RESULTS: Six (7%) of 82 patients in the omeprazole group had recurrent bleeding, as compared with 18 (21%) in the placebo group (P = 0.02). Two patients in the omeprazole group and 7 patients in the placebo group needed surgery to control their bleeding (P = 0.17). One patient in the omeprazole group and 2 patients in the placebo group died (P = 0.98). Twenty-nine patients (35%) in the omeprazole group and 61 patients (73%) in the placebo group received blood transfusions (P <0.001). The average hospital stay was 4.6 +/- 1.1 days in the omeprazole group and 6.0 +/- 0.7 days in the placebo group (P <0.001). CONCLUSION: The addition of oral omeprazole to combination injection sclerotherapy decreases the rate of recurrent bleeding, reduces the need for surgery and transfusion, and shortens the hospital stay for patients with stigmata of recent hemorrhage.

Anti-Ulcer Agents↗
PubMed2001

Toxicity studies in mice of Commiphora molmol oleo-gum-resin.

Acute (24 h) and chronic (90 days) oral toxicity studies on Commiphora molmol (oleo-gum-resin) were carried out in mice. Dosages in acute study were 0.5, 1.0 and 3 g/kg, while in chronic study dosage was 100 mg/kg per day. All external morphological, biochemical and haematological changes, in addition to body and vital organ weights were recorded. There was no significant difference in mortality in acute or chronic treatment as compared to controls. At the end of the treatment, weight gain in the treated as well as control group was significant. There was a significant increase in weight of testes, caudae epididymides and seminal vesicles in C. molmol treated group. Biochemical studies revealed no differences in C. molmol treated animals, however, haematological studies revealed a significant increase in RBC and haemoglobin levels as compared to the control group. C. molmol failed to show any spermatotoxic effects.

Animals↗
PubMed2001

Effect of Saral meditation on intelligence, performance and cardiopulmonary functions.

Meditation is a mental exercise to improve mental faculty. Present attempt was to evaluate effect of Saral Meditation on development of intelligence, academic performance & cardiopulmonary functions. Results show significant improvement in development of intelligence and academic performance. There was apparent improvement in confidence and they were free from anxiety. There were also considerable changes in psychomotor ability and cardiopulmonary functions however, result was not significant.

Hemodynamics↗
PubMed2000

TGF-beta-based immunotherapy for cancer: breaching the tumor firewall.

Many malignant cells secrete transforming growth factor-beta (TGF-beta), a potent immunosuppresant, suggesting that TGF-beta production may represent a significant tumor escape mechanism from host immunosurveillance. Establishment of a leukocyte subpopulation with disrupted TGF-beta signaling in the tumor-bearing host offers a potential means for immunotherapy of cancer. Downregulation of TGF-beta secretion in tumor cells results in restoration of immunogenicity in the host, while T-cell insensitivity to TGF-beta results in accelerated differentiation and autoimmunity, elements of which may be required in order to combat self-antigen-expressing tumors in a tolerized host. The rationale, approaches, and potential pitfalls of this strategy will be discussed.

Animals↗
PubMed1999

A Salmonella virulence protein that inhibits cellular trafficking.

Salmonella enterica requires a type III secretion system, designated Spi/Ssa, to survive and proliferate within macrophages. The Spi/Ssa system is encoded within the SPI-2 pathogenicity island and appears to function intracellularly. Here, we establish that the SPI-2-encoded SpiC protein is exported by the Spi/Ssa type III secretion system into the host cell cytosol where it interferes with intracellular trafficking. In J774 macrophages, wild-type Salmonella inhibited fusion of Salmonella-containing phagosomes with lysosomes and endosomes, and interfered with trafficking of vesicles devoid of the microorganism. These inhibitory activities required living Salmonella and a functional spiC gene. Purified SpiC protein inhibited endosome-endosome fusion in vitro. A Sindbis virus expressing the SpiC protein interfered with normal trafficking of the transferrin receptor in vivo. A spiC mutant was attenuated for virulence, suggesting that the ability to interfere with intracellular trafficking is essential for Salmonella pathogenesis.

Amino Acid Sequence↗
PubMed1999

Transforming growth factor-beta in benign and malignant prostate.

BACKGROUND: The present review summarizes the cellular action of TGF-beta in benign and malignant growth of the prostate. METHODS: TGF-beta is a pleiotropic growth factor. It plays an important role in the regulation of growth and differentiation in many cells. In benign prostatic epithelia, its action is mediated through a paracrine mechanism. It inhibits proliferation and induces apoptosis in prostatic epithelia. It provides a mechanism to maintain epithelial homeostasis in the prostate. In prostatic stroma, its continual action leads to smooth muscle differentiation. This effect of TGF-beta may regulate the development of prostatic smooth muscle nodules in benign prostatic hyperplasia. RESULTS: As prostatic epithelial cells undergo malignant transformation, two major events occur regarding TGF-beta action. These include the loss of expression of functional TGF-beta receptors and overproduction of TGF-beta in malignant cells. The loss of expression of functional TGF-beta receptors provides a growth advantage to cancer cells over their benign counterparts. The overproduction of TGF-beta by cancer cells has a multitude of adverse consequences. TGF-beta can promote extracellular matrix production, induce angiogenesis, and inhibit host immune function. The biological consequence of these activities is an enhanced tumorigenicity in prostate cancer. Results of our recent studies with a rat prostate cancer model suggest that the immunosuppressive effect of TGF-beta seems to be the primary cause of tumor progression. This is because, if these cancer cells were engineered to reduce the production of TGF-beta, tumor growth was inhibited in syngeneic hosts but not in immune compromised hosts. CONCLUSIONS: Our future research should take advantage of this knowledge to devise therapeutic strategies aimed at eradicating prostate cancer.

Androgens↗
PubMed1999

Molecular basis for the enterocyte tropism exhibited by Salmonella typhimurium type 1 fimbriae.

Salmonella typhimurium exhibits a distinct tropism for mouse enterocytes that is linked to their expression of type 1 fimbriae. The distinct binding traits of Salmonella type 1 fimbriae is also reflected in their binding to selected mannosylated proteins and in their ability to promote secondary bacterial aggregation on enterocyte surfaces. The determinant of binding in Salmonella type 1 fimbriae is a 35-kDa structurally distinct fimbrial subunit, FimHS, because inactivation of fimHS abolished binding activity in the resulting mutant without any apparent effect on fimbrial expression. Surprisingly, when expressed in the absence of other fimbrial components and as a translational fusion protein with MalE, FimHS failed to demonstrate any specific binding tropism and bound equally to all cells and mannosylated proteins tested. To determine if the binding specificity of Salmonella type 1 fimbriae was determined by the fimbrial shaft that is intimately associated with FimHS, we replaced the amino-terminal half of FimHS with the corresponding sequence from Escherichia coli FimH (FimHE) that contains the receptor binding domain of FimHE. The resulting hybrid fimbriae bearing FimHES on a Salmonella fimbrial shaft exhibited binding traits that resembled that of Salmonella rather than E. coli fimbriae. Apparently, the quaternary constraints imposed by the fimbrial shaft on the adhesin determine the distinct binding traits of S. typhimurium type 1 fimbriae.

Adhesins, Bacterial↗
PubMed1999

Ascaris-induced liver abscess.

The prevalence, symptomatology, and outcome of Ascaris-induced liver abscess was studied prospectively in Kashmir, India, which is an endemic area of ascariasis, from December 1987 to December 1997. Of 510 patients with liver abscess admitted during this period, 74 had biliary ascariasis as the cause (14.51%). Of these 74 patients, 11 had intact ascaridae (live or dead) within the abscess. Six patients had a single abscess, and five had multiple abscesses. Seven patients had associated worms in the bile ducts. Ultrasonography was the main diagnostic procedure used. Ten patients were diagnosed based on clinical and ultrasound findings, and one was diagnosed during laparotomy. Most of the patients were young (age range 3-40 years) with a mean age of 17.20 years. Seven were females, and four were males. Ten patients underwent surgery; nine recovered completely, and one died postoperatively due to septicemia. Another patient died as well: a young child who presented late, was in refractory septic shock following suppurative cholangitis and liver abscess, and could not be taken for surgery. The mortality thus was 9.9%. Liver abscess following invasion of intrahepatic biliary radicles by ascaridae through the ampulla is an unusual complication of an otherwise common disease in Kashmir Valley, affecting children and young adults. The outcome depends on early diagnosis and surgical drainage of the abscess with extraction of worms from the ducts.

Adolescent↗
PubMed1998

Toxicity studies in mice of common spices, Cinnamomum zeylanicum bark and Piper longum fruits.

Acute (24 hours) and chronic (90 days) oral toxicity studies on the ethanolic extracts of common spices Cinnamomum zeylanicum Nees bark and Piper longum L. fruits were carried out in mice. Acute dosages were 0.5, 1.0 and 3 g/kg while the chronic dosage was 100 mg/kg/day. All external morphological, hematological and spermatogenic changes, in addition to body weight and vital organ weights, were recorded. The extracts of both the plants caused no significant acute or chronic mortality compared to the control during this study. During chronic treatment there was no significant change in the pre- and post treatment body weight of the test animals while the weight gain in the control group was significant. C. zeylanicum treatment caused reduction in liver weight while P. longum caused a significant increase in the weight of the lungs and spleen of the treated animals compared to the control. Hematological studies revealed a significant fall in hemoglobin level of C. zeylanicum treated animals. Both of the extracts induced a significant increase in reproductive organ weights, sperm motility, sperm count and failed to illicit any spermatotoxic effect.

Animals↗
PubMed1998

Short-course ceftriaxone therapy in spontaneous bacterial peritonitis.

Forty patients with spontaneous bacterial peritonitis, three of whom had complicating acute hepatitis syndrome, eight late-onset hepatic failure, and 29 with cirrhosis, were treated with ceftriaxone 2 g intravenously once daily for 5 days. Ascitic fluid culture was positive in 28 patients, with Escherichia coli and Klebsiella as common isolates. All the bacteria isolated were sensitive to ceftriaxone except Enterococcus faecalis, which was isolated in a cirrhotic patient. All culture-positive patients sensitive to ceftriaxone showed bacteriological cure and 26 (65%) patients showed cytological cure after 48 hours of treatment. A total of 95% were cured of their infection after 5 days of treatment. Twelve (30%) patients died during hospitalisation after documented cure of their spontaneous bacterial peritonitis (renal failure, gastrointestinal bleed and cerebral oedema were the primary causes of death). Infection-related mortality due to Pseudomonas septicaemia was seen in one cirrhotic patient.

Adolescent↗
PubMed1997

Percutaneous drainage compared with surgery for hepatic hydatid cysts.

BACKGROUND: In recent years percutaneous drainage has been used successfully to treat the hepatic hydatid cysts of echinococcal disease. We performed a controlled trial to compare the safety and efficacy of percutaneous drainage with those of surgical cystectomy, the traditional treatment. METHODS: In a prospective study, we randomly assigned 50 patients with hepatic hydatidosis to treatment with percutaneous drainage (25 patients) or cystectomy (25). Albendazole (10 mg per kilogram of body weight per day for eight weeks) was administered to the patients who underwent percutaneous drainage. Serial assessments included clinical and biochemical examinations, ultrasonography, and serologic tests of echinococcal-antibody titers. RESULTS: The mean (+/-SD) hospital stay was 4.2+/-1.5 days in the drainage group and 12.7+/-6.5 days in the surgery group (P<0.001). Over a mean follow-up period of 17 months, the mean cyst diameter decreased from 8.0+/-3.0 to 1.4+/-3.5 cm (P<0.001) after percutaneous drainage and from 9.1+/-3.0 to 0.9+/-1.8 cm (P<0.001) after surgery. The final cyst diameter did not differ significantly between the two groups (P=0.20). The cysts disappeared in 22 patients (88 percent) in the drainage group and in 18 (72 percent) in the surgery group (P=0.29). After an initial rise, the echinococcal-antibody titers fell progressively and at the last follow-up were negative (<1:160) in 19 patients (76 percent) in the drainage group and 17 (68 percent) in the surgery group (P=0.74). There were procedure-related complications in 8 patients (32 percent) in the drainage group and 21 (84 percent) in the surgery group, 17 of whom had fever postoperatively (P<0.001). CONCLUSIONS: Percutaneous drainage, combined with albendazole therapy, is an effective and safe alternative to surgery for the treatment of uncomplicated hydatid cysts of the liver and requires a shorter hospital stay.

Adolescent↗
PubMed1997

Localization of a domain in the FimH adhesin of Escherichia coli type 1 fimbriae capable of receptor recognition and use of a domain-specific antibody to confer protection against experimental urinary tract infection.

The FimH subunit of type 1-fimbriated Escherichia coli has been implicated as an important determinant of bacterial adherence and colonization of the urinary tract. Here, we sought to localize the functionally important domain(s) within the FimH molecule and to determine if antibodies against this domain would block adherence of type 1-fimbriated E. coli to the bladder mucosa in situ and in vivo in an established mouse model of cystitis. We generated translational fusion proteins of disparate regions of the FimH molecule with an affinity tag MalE, and tested each of the fusion products in vitro for functional activity. The minimum region responsible for binding mouse bladder epithelial cells and a soluble mannoprotein, horseradish peroxidase, was contained within residues 1-100 of the FimH molecule. We validated and extended these findings by demonstrating that antibodies directed at the putative binding region of FimH or at synthetic peptides corresponding to epitopes within the binding domain could specifically block type 1 fimbriae-mediated bacterial adherence to bladder epithelial cells in situ and yeast cells in vitro. Next, we compared the ability of mice passively immunized intraperitoneally with antisera raised against residues 1-25 and 253-264 of FimH or 1-13 of FimA to resist bladder colonization in vivo after intravesicular challenge with type 1-fimbriated E. coli. Only the antibody directed at the putative binding region of FimH (anti- s-FimH1-25) significantly reduced E. coli bladder infections in the experimental mouse model of urinary tract infections. Similar results were obtained when the mice were actively immunized with synthetic peptides corresponding to residues 1-25 and 253-264 of FimH or 1-13 of FimA. The mechanism of protection was attributed, at least in part, to inhibition of bacterial adherence to the bladder surface by s-FimH1-25-specific antibody molecules that had filtered through the kidneys into the urine. The level of FimH antibodies entering the bladder from the circulatory system of the immunized mice was found to be markedly enhanced upon bacterial challenge. The potential broad spectrum activity of the protective FimH antibody was indicated from its serologic cross-reactivity with various urinary tract bacterial isolates bearing type 1 fimbriae. These findings could be relevant in the design of an efficacious and broadly reactive FimH vaccine against urinary tract infections.

ATP-Binding Cassette Transporters↗
PubMed1997

Gastric antiulcer and cytoprotective effect of Commiphora molmol in rats.

The aqueous suspension of Commiphora molmol (oleo-gum resin) has been screened for its potential to protect gastric mucosa against the ulcers caused by 80% ethanol, 25% NaCl, 0.2 M NaOH, indomethacin and combined indomethacin-ethanol treatment. C. molmol pretreatment at doses of 250, 500 and 1000 mg/kg provided dose-dependent protection against the ulcerogenic effects of different necrotizing agents used. The effects caused by ethanol were further investigated. Treatment of rats with 1 ml of 80% ethanol was found to cause depletion of stomach wall mucus, reduction in the concentration of protein, nucleic acids and NP-SH groups in the stomach wall. Ethanol treatment also caused histopathological lesions including necrosis, erosion, congestion and haemorrhage of the stomach wall. Pretreatment with C. molmol offered a dose-dependent protection against all these effects. In the same manner it affected the malondialdehyde concentration altered by ethanol treatment. C. molmol also offered protection against mucosal damage caused by indomethacin and its combination with ethanol. The protective effect of C. molmol observed in the present study is attributed to its effect on mucus production, increase in nucleic acid and non-protein sulfhydryl concentration, which appears to be mediated through its free radical-scavenging, thyroid-stimulating and prostaglandin-inducing properties.

Animals↗