Nicotinamidase (Nic) is a key zinc-dependent enzyme in NAD metabolism that catalyzes the hydrolysis of nicotinamide to give nicotinic acid. A multi-scale computational approach has been used to investigate the catalytic mechanism, substrate binding and roles of active site residues of Nic from Streptococcus pneumoniae (SpNic). In particular, density functional theory (DFT), molecular dynamics (MD) and ONIOM quantum mechanics/molecular mechanics (QM/MM) methods have been employed. The overall mechanism occurs in two stages: (i) formation of a thioester enzyme-intermediate (IC2) and (ii) hydrolysis of the thioester bond to give the products. The polar protein environment has a significant effect in stabilizing reaction intermediates and in particular transition states. As a result, both stages effectively occur in one step with Stage 1, formation of IC2, being rate limiting barrier with a cost of 53.5 kJ·mol −1 with respect to the reactant complex, RC. The effects of dispersion interactions on the overall mechanism were also considered but were generally calculated to have less significant effects with the overall mechanism being unchanged. In addition, the active site lysyl (Lys103) is concluded to likely play a role in stabilizing the thiolate of Cys136 during the reaction.

Objective: To evaluate the clinical success, technical success and complications related to Endoscopic ultrasound (EUS) guided Pancreatic pseudocyst (PPC) drainage. Methods: This retrospective study was conducted on the patients with symptomatic PPC who presented over a period of three years, between January 2015 and September 2018, at Endoscopic Suite of Surgical Unit 4, Civil Hospital, Karachi. Record was analyzed for demographic data, indications for the procedure, complications and success related to EUS guided drainage. Statistical analyses were performed using the SPSS Version 22. Results: Total number of patients was 71. Mean age was 37.20 ± 17.27 years with a range of 6 to 68 years. Complications occurred in 12 (8.52%) patients, including stent migration (5/12), bleeding (4/12), infection (1/12), intra-abdominal abscess (1/12) and perforation (1/12). Technical success was achieved in 100% and clinical success in 97.1%. There was no procedure-related mortality. Conclusion: Pancreatic pseudocyst (PPC) is a known complication of acute as well as chronic pancreatitis which can have dreaded and appalling effects. In this part of the world with limited and scarce resources, EUS guided drainage of PPC is most feasible and rational with minimal complications, thus making it a front runner procedure. doi: https://doi.org/10.12669/pjms.36.4.1442 How to cite this:Kazim E, Taj MA, Zulfikar I, Azeem J. Endoscopic Ultrasound Guided Pancreatic Pseudocyst drainage experience at a tertiary care unit. Pak J Med Sci. 2020;36(4):---------. doi: https://doi.org/10.12669/pjms.36.4.1442 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Aim: To determine the frequency of in hospital mortality and to compare this frequency of mortality with CRP/Albumin ration in patients with surgical abdomen and/or chest trauma. Study Design: Cross-sectional study Place and Duration of Study: Surgical Unit IV, Civil Hospital Karachi from 26th June 2019 to 25th December 2019. Methodology: One hundred and thirty one patients with abdominal and/or chest surgical trauma were enrolled within 24 hours of trauma. Serum CRP level and serum albumin level were done through hospital hematology laboratory and CRP/albumin ration was calculated and relation with in hospital mortality was found. Results: The mean age of patients was 34.24±15.5 years with 74 male and 57 females. Mean height was 167.5±13.9 cm, mean weight was 62.6±8.6 kg and mean BMI was22.4±5.3kg/m2. Mean CRP was 14.3±9.6 mg/dl, mean albumin was 3.76±0.98 g/dl and mean CRP/Albumin ratio was 3.74±2.3.In CRP/Albumin cluster there were 32.1% patients in 0.01-2 cluster, 43.5% in 2.01-4 cluster and 32.1% in 4.01-9 cluster. 12.2% patients were expired among them there were 7.1% expiry rate in 0.01-2 cluster, 10.6% in 2.01-4 cluster and 19% patients expired in 4.01-9. Increased CRP/Albumin cluster was associated with increased mortality rate. Conclusion: An elevated CRP/Albumin ratio in traumatized patient was associated with an increased risk of mortality. Keywords: Surgical trauma, Prognostic marker, CRP/albumin ratio

Aim: To explore the perceptions, limitations and recommendations for hybrid teaching. Methodology: This is a cross sectional study, conducted in the academic session of 2021 among the students of Dow medical college including third years through final years. Convenient sampling is used. The questionnaire was created on Google and forms were emailed to the students. Likert scale is applied to record the responses. Results: Total of 102 students of both genders filled the questionnaire. Students were mostly from third year, fourth year and final year. Most of the students had no previous experience of e- learning. 36.3% students agreed that hybrid teaching is better than face to face or online sessions alone. 31.4% were of the opinion that hybrid teaching covers the strong points of both face to face and online teaching. Conclusion: Covid-19 makes classroom medical education difficult but blended or hybrid teaching and learning would seem to be the perfect solution to overcome the challenges. Keywords: Hybrid teaching, distance learning, Covid 19

Spigelian hernia is rare and generally difficult to diagnose because of its location and vague non-specific symptoms. A Spigelian hernia occurs through the Spigelian fascia, which is composed of the aponeurotic layer between rectus muscle medially and semilunar line laterally. Nearly all Spigelian hernias occur at or below the arcuate line. The absence of posterior rectus fascia may contribute to an inherent weakness in this area. These are often interparietal, with the hernia sac dissecting posterior to the external oblique aponeurosis. Patient often present with localized pain in the area without a bulge because the hernia lies beneath the intact external oblique aponeurosis and they are easily overlooked by obesity. Ultrasound or CT scan of the abdomen can be useful to establish the diagnosis. Spigelian hernias should always be surgically repaired in view of the high frequency of incarceration.