New insight on 8-anilino-1-naphthalene sulfonic acid interaction with TgFNR for hydrophobic exposure analysis.

The exposed hydrophobic patches of protein are widely detected through the binding by the fluorescent probes such as 1-anilino-8-naphthalene sulfonate (ANS), Nile Red (NR) and 1-(N-phenylamino) naphthalene, N-(1-Naphthyl) aniline (1NPN). Interestingly, at pH4, where the Toxoplasma gondii Ferredoxin-NADP(+) reductase (TgFNR) is stable, an exclusive binding and fluorescence emission was observed for ANS. To understand the underlying difference in the binding of ANS, NR and 1NPN; their effect on the protein structure was studied in detail. ANS was found to interact with TgFNR via electrostatic as well as hydrophobic interactions at pH4. NR and 1NPN did not show any such binding to TgFNR in the similar conditions, however showed strong hydrophobic interaction in the presence of NaCl or DSS (2, 2-dimethyl-2-silapentane-5-sulfonate). The subsequent structural studies suggest that ANS, NaCl and DSS induced partial unfolding of TgFNR by modulating ionic interactions of the enzyme, leading to the exposure of buried hydrophobic patches amicable for the binding by NR and 1NPN. The induced unfolding of TgFNR by ANS is unique and thus cautions to use the fluorescent dye as simple indicator to probe the exposed hydrophobic patches of the protein or its folding intermediates.

General practitioner's knowledge regarding the diagnosis and drug therapy for acute myocardial infarction.

OBJECTIVE: To assess the general practitioners (GP) knowledge regarding the diagnosis and initial drug therapy for acute myocardial infarction (AMI). METHODS: A questionnaire-based survey was conducted in randomly selected GPs of Karachi. Doctors working in community as GPs who were registered medical practitioners having a Bachelor of Medicine & Bachelor of Surgery degree were included in the study. Doctors working at tertiary care facilities or having a post graduate degree or post graduate training in a specialty other than family medicine were excluded from the study. RESULTS: A total of 186 GPs participated in our study. GPs who studied research journals were 2.33 times more likely to investigate serum cardiac troponins levels for the diagnosis of AMI compared to those who did not study research journals (P = 0.02). Twenty six percent of the GPs said that they would refer a patient with suspected AMI without treatment, while 76% said that they would consider some treatment prior to referral. Fifty eight percent of the GPs identified ST segment elevation myocardial infarction (STEMI) of < 12 hours duration as an indication of thrombolysis while 28% identified posterior wall AMI as a thrombolytic indication. CONCLUSION: GPs, although adequately aware of the presenting features of AMI, were lacking in knowledge regarding the means for confirmation of diagnosis, initial drug therapy and were less likely to carry management steps in their practice.

Clinical outcomes of sirolimus with eluting stent implantation in coronary artery disease.

OBJECTIVE: To evaluate the immediate post procedure, thirty-days, and six-months clinical outcomes of sirolimus-eluting stents (SES) implantation in patients with single and multivessel coronary artery disease (CAD). METHODS: A case series of all consecutive patients undergoing percutaneous coronary interventions (PCI) with SES implantation at Shifa International Hospital, Islamabad, were evaluated at early post-procedure, 30-days and six-months clinical follow-up for the incidence of major adverse cardiac event (MACE). This included death, nonfatal myocardial infarction (MI) and repeat revascularization. RESULTS: Out of 206 consecutive patients, 324 had SES implanted. Cumulative MACE rate was 2.93% and 6% at 30-days and six-months follow-ups respectively. Five patients developed ST-segment elevation MI (STEMI). One patient developed non-STEMI. Emergency Coronary Artery Bypass Grafting (CABG) was done in two patients. Repeat (PCI) was carried in three (1.46%) patients for acute in-stent thrombosis. Diabetes Mellitus and multivessel stenting were found to be the independent predictors for acute in-stent thrombosis (P-value < 0.02 and 0.05 respectively). CONCLUSION: SES implantation in coronary artery disease can be safe and effective MACE at one and six months follow-ups.

Synthesis and characterization of silicalite-1/carbon-graphite membranes.

Silicalite-1/carbon-graphite composite membranes have been prepared using a standard hydrothermal synthesis method and characterized by XRD, SEM, TGA, BET and permeation experiments. Single gas permeation fluxes and binary mixtures separation and selectivity data are reported for methane, ethane and propane using the composite membranes. Carbon-graphite oxidized for 4 h prior to membrane preparation had the most promising separation properties. The permeation fluxes for the binary mixtures reflect that of the single component flux ratios. At 20 degrees C the membranes show high separation selectivity toward lighter component in binary mixtures. Single gas permeances for methane and ethane were found to decrease with increasing temperatures while that of propane fluctuates.

Liaison psychiatry and depression in medical inpatients.

OBJECTIVE: To assess the frequency of depression among hospitalized patients, the socio-demographic variables associated with depression and the number of cases referred by physicians to Psychiatry. METHODS: A cross-sectional study was carried out at the Aga Khan University Hospital Karachi. An anonymous Urdu version of the WHO-developed self-reporting questionnaire (SRQ) was administered to inpatients meeting the inclusion criteria. Data was analyzed by SPSS version 13.0. RESULT: Of the 225 patients approached, 178 completed the questionnaire (men= 45.2%, women = 54.8%). The mean age of the sample was 45.2 years. Out of the total 30.5% of patients were identified as having probable depression, among which housewives were more likely to be depressed compared to others (p=0.031). Among variable comparison, there with secondary school education or below and those with psychiatric co-morbidities, showed significantly greater prevalence of depression (p=0.003) and (p=0.005) respectively. Attending physicians correctly diagnosed 7 (13%) patients and referred only 3 patients to Psychiatry over the previous month. CONCLUSION: The prevalence of depression among inpatients is comparable to that in the general population. Being a housewife, level at or below secondary school education and having a past psychiatric history are significant factors associated with depression in medical inpatients. A very small number of depressed cases were referred to a psychiatrist.