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Biomedical subjects

A Malik

Publications and source records attributed to A Malik.

At least 19 recordsLinked to original sources
PubMed2006

Endoluminal and transluminal surgery: current status and future possibilities.

The field of minimally invasive surgery has seen tremendous growth since the first laparoscopic cholecystectomy was performed in 1987. The key question is not how successful these techniques are currently, but rather where may they lead in the future? New technologies promise to usher in an era of even less invasive procedures. The terms being coined in the literature include "incisionless," "endoluminal," "transluminal," and "natural orifice" transluminal endoscopic surgery. These techniques certainly have the potential to become the next wave of minimally invasive procedures. A recent editorial in Surgical Endoscopy by Macfadyen and Cuschieri highlighted the ongoing developments in endoscopic surgery and stressed the critical importance of surgeons being involved in future applications and permutations of these techniques [1]. There are early signs of such involvement. The work of numerous investigators in the field was presented recently at the 2005 Digestive Disease Week. The American Society for Gastrointestinal Endoscopy and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), in collaboration with the American College of Surgeons, recently organized a postgraduate course in endoluminal therapy at the spring 2005 meeting held in Hollywood, Florida. The course is being offered again at the 2006 SAGES annual meeting. Similar courses are being offered at other regional and national meetings. This review attempts to highlight some of the available and evolving endoluminal therapies reviewed at that forum, including techniques for the management of gastroesophageal reflux disease, endoscopic mucosal resection, endoluminal bariatric surgery, transanal endoscopic microsurgery, and transgastric endoscopic surgery, as well as new technologies and possible future directions in luminal access surgery.

Bariatric Surgery↗
PubMed2006

Phenotypic and genetic characterization of enteropathogenic Escherichia coli (EPEC) and entero-aggregative E. coli (EAEC) from diarrhoeal and non-diarrhoeal children in Libya.

A total of 50 Escherichia coli strains isolated in a Libyan hospital (20 from children with diarrhoea and 30 from healthy children) were investigated for their pathotypes and virulence traits. Altogether nine eae-positive (enteropathogenic E. coli, EPEC) and nine aggR-positive (entero-aggregative E. coli, EAEC) strains were identified. Significantly (P=0.001) more EPEC strains were identified from diarrhoeal patients (n=8) than from healthy controls (n=1), while six EAEC strains were identified from diarrhoeal and three from healthy children. Typical (eae(+), EAF(+), bfp(+)) EPEC strains (n=6) belonged to classical EPEC serogroups O55, O114, O127 and showed localized adherence on Hela cells. EAEC strains revealed genetic heterogeneity but uniformly adhered to HeLa cultures in an entero-aggregative adherence pattern. Antibiotic resistance frequently, characterized the strains. Sixty-eight percentage of the strains were resistant against at least one antibiotic and 30% harbored a class 1 integron independently of their clinical background. This is the first report from North Africa demonstrating the significance of EPEC and EAEC.

Adhesins, Bacterial↗
PubMed2006

Fournier's gangrene and its emergency management.

Fournier's gangrene (FG) is a rare but life threatening disease. Although originally thought to be an idiopathic process, FG has been shown to have a predilection for patients with diabetes as well as long term alcohol misuse; however, it can also affect patients with non-obvious immune compromise. The nidus is usually located in the genitourinary tract, lower gastrointestinal tract, or skin. FG is a mixed infection caused by both aerobic and anaerobic bacterial flora. The development and progression of the gangrene is often fulminating and can rapidly cause multiple organ failure and death. Because of potential complications, it is important to diagnose the disease process as early as possible Although antibiotics and aggressive debridement have been broadly accepted as the standard treatment, the death rate remains high.

Anti-Bacterial Agents↗
PubMed2005

Tyrosinase inhibitory lignans from the methanol extract of the roots of Vitex negundo Linn. and their structure-activity relationship.

Phytochemical investigation of the methanol extract of Vitex negundo afforded eight lignans; negundin A 1, negundin B 2, 6-hydroxy-4-(4-hydroxy-3-methoxy)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaledehyde 3, vitrofolal E 4, (+)-lyoniresinol 5, (+)-lyoniresinol-3alpha-O-beta-d-glucoside 6, (+)-(-)-pinoresinol 7, and (+)-diasyringaresinol 8. The structures of these compounds were elucidated unambiguously by spectroscopic methods including 1D and 2D NMR analysis and also by comparing experimental data with literature data. The tyrosinase inhibitory potency of these compounds has been evaluated and attempts to justify their structure-activity relationships have been made in the present work. The compound 5 was found to be the most potent (IC(50)=3.21 microM) while other compounds demonstrated moderate to potent inhibitions. It was found that the substitution of functional group(s) at C-2 and C-3 positions and the presence of the -CH(2)OH group plays a vital role in the potency of the compounds. The compound 5 can act as a potential lead molecule to develop new drugs for the treatment of hyperpigmentation associated with the high production of melanocytes.

Inhibitory Concentration 50↗
PubMed2005

Overexpression of sorcin enhances cardiac contractility in vivo and in vitro.

Sorcin (SOR), an EF-hand Ca(2+)-binding protein, interacts with the sarcolemmal proteins Annexin VII and L-type Ca(2+)-channel and with the sarcoplasmic reticulum (SR) Ca(2+)-release channel (ryanodine-receptor, RYR), and has been implicated to influence the intracellular Ca(2+)-homeostasis. The present study aimed at investigating the effects of increased SOR expression on force development and relaxation in virus transfected rat hearts and isolated cardiomyocytes. We generated an adenovirus encoding the SOR coding DNA with a separate cassette for green fluorescent protein (GFP) both driven by the CMV-promoter to induce SOR-overexpression (Ad.SOR.GFP). As control served an adenovirus carrying an empty cassette with a separate cassette for GFP also driven by CMV-promoters (Ad.GFP). Cardiomyocytes of healthy male rats were isolated, transfected and cultured for 48 h with Ad.SOR.GFP as well as Ad.GFP as control. In addition, Ad.SOR.GFP was injected into coronary arteries via a catheter-based technique and rat hearts were transfected in vivo for 12 days. Echocardiography was performed to assess cardiac function at 7 and 12 days before the animals were sacrificed. A 1.7-fold increase of the SOR protein amount in cultured myocytes treated with Ad.SOR.GFP compared to Ad.GFP-transfected cells indicated a successful overexpression of SOR. Cell-contracting experiments using infected cardiomyocytes (transfection: 48 h; frequency: 0.5 Hz) exhibited a significantly higher peak force of contraction (FOC) in the SOR-overexpression group (n = 64) vs. control (n = 21) (6.8% +/- 0.2% vs. 4.3% +/- 0.1%). Beta-adrenergic stimulation with forskolin resulted in similar increases in FOC. Echocardiography of in vivo transfected rat hearts exhibited enhanced fractional shortening (65.9 +/- 5.5% vs. 79.3 +/- 2.5%) and decreased end-systolic diameters indicating enhanced cardiac contractility. Gross morphology was similar in both groups after 14 days of transfection. These results strengthen the notion that overexpression of SOR improves cardiac contractility independent of beta-adrenergic stimulation and may prove beneficial in the treatment of decreased cardiac output such as heart failure.

Adenoviridae↗
PubMed2005

Preoperative intravenous fluid therapy decreases postoperative nausea and pain in high risk patients.

The potential for preoperative IV rehydration to reduce postoperative nausea and vomiting (PONV) and pain in patients undergoing ambulatory surgery remains unclear, with conflicting results reported. We sought to determine whether preoperative IV rehydration with a balanced salt solution would decrease the incidence of PONV in patients at increased risk for these symptoms. Eighty ASA grade I-III patients presenting for gynecologic laparoscopy were randomized to receive large (2 mL/kg per hour fasting) or small (3 mL/kg) volume infusions of compound sodium lactate solution over 20 min preoperatively. A standardized balanced anesthetic was used. The incidence and severity of PONV and pain, and need for supplemental antiemetic and analgesic therapy, were assessed by a blinded investigator at 0.5, 1, and 4 h postoperatively, and on the first and third postoperative days. The incidence (control 87% versus large volume 59%) and severity of PONV were significantly reduced in the large volume infusion group at all time intervals. The large volume infusion group also had decreased postoperative pain scores and required less supplemental analgesia. Preoperative correction of intravascular volume deficits effectively reduces PONV and postoperative pain in high risk patients presenting for ambulatory surgery. We recommend the preoperative administration of 2 mL/kg of compound sodium lactate for every hour of fasting to patients with an increased PONV risk presenting for ambulatory surgery.

Adult↗
PubMed2004

Search for pi(0)-->nu(mu)nu(mu) decays in the LSND detector.

We observe a net beam excess of 8.7+/-6.3(stat)+/-2.4(syst) events, above 160 MeV, resulting from the charged-current reaction of nu(micro) and/or nu;(mu) on C and H in the LSND detector. No beam-related muon background is expected in this energy regime. Within an analysis framework of pi(0)-->nu(mu)nu;(mu), we set a direct upper limit for this branching ratio of Gamma(pi(0)-->nu(mu)nu;(mu))/Gamma(pi(0)-->all)<1.6 x 10(-6) at 90% confidence level.

Journal Article↗
PubMed2004

The biflavonoid, amentoflavone degrades DNA in the presence of copper ions.

Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.

Animals↗
PubMed2004

Congenital infiltrating lipomatosis of the face and neck.

Congenital infiltrating lipomatosis is a rare clinicopathologic entity characterized by infiltrating lipomatous tumors which, although of benign nature, have a tendency to recur after surgery. This has a predilection for the extremities and the trunk and is seen as overgrowth of soft tissue and bone. It rarely affects the face and neck. We describe two cases of congenital infiltrating lipomatosis of face and neck depicting the bone and soft tissue changes seen on computed tomography, along with a review of the literature on the subject.

Adult↗