Ultracold collisions of O(1D) and H2: the effects of H2 vibrational excitation on the production of vibrationally and rotationally excited OH.

A quantum dynamics study of the O((1)D) + H2(v = 0 - 2, j = 0) system has been carried out using the potential energy surfaces of Dobbyn and Knowles [Mol. Phys. 91, 1107 (1997)]. A time-independent quantum mechanical method based on hyperspherical coordinates is adopted for the dynamics calculations. Energy dependent cross section, probability, and rate coefficients are computed for the elastic, inelastic, and reactive channels over collision energies ranging from the ultracold to thermal regimes and for total angular momentum quantum number J = 0. The effect of initial vibrational excitation of the H2 molecule on vibrational and rotational populations of the OH product is investigated as a function of the collision energy. Comparison of results for vibrational levels v = 0 - 2 of H2 demonstrates that the vibrational excitation of H2 and its non-reactive relaxation pathway play a minor role in the overall collisional outcome of O((1)D) and H2. It is also found that while the state-resolved product vibrational distributions are sensitive to the initial collision energy and H2 vibrational level, the product rotational distribution depicts an inverted population that is largely insensitive to initial conditions. Rate coefficients evaluated using a J-shifting approximation show reasonable agreement with available theoretical and experimental results suggesting that the J-shifting approximation may be used to evaluate the rate coefficients for O((1)D) + H2 reaction.

Chemical reaction versus vibrational quenching in low energy collisions of vibrationally excited OH with O.

Quantum scattering calculations are reported for state-to-state vibrational relaxation and reactive scattering in O + OH(v = 2 - 3, j = 0) collisions on the electronically adiabatic ground state (2)A'' potential energy surface of the HO2 molecule. The time-independent Schrödinger equation in hyperspherical coordinates is solved to determine energy dependent probabilities and cross sections over collision energies ranging from ultracold to 0.35 eV and for total angular momentum quantum number J = 0. A J-shifting approximation is then used to compute initial state selected reactive rate coefficients in the temperature range T = 1 - 400 K. Results are found to be in reasonable agreement with available quasiclassical trajectory calculations. Results indicate that rate coefficients for O2 formation increase with increasing the OH vibrational level except at low and ultralow temperatures where OH(v = 0) exhibits a slightly different trend. It is found that vibrational relaxation of OH in v = 2 and v = 3 vibrational levels is dominated by a multi-quantum process.

An analysis of surgical complications; a tool to improve surgical outcome.

Complications in surgery are an important cause of morbidity and mortality. Complications may result in an increased length of stay in hospital, repeat surgery, additional medical treatment, legal issues and increased costs. Classification and regular audit of complications is a useful tool to improve patient safety and surgical outcome. The purpose of this study is to identify and classify surgical complications and evaluate the various contributing factors. The complications were categorized by Clavein Dindo system as Grade 1:52 (29.1%), Grade II :45 (25.1%),Grade IIIa:26 (14.5%), Grade IIIB:25 (14%), Grade IVa:5 (2.8%), Grade IVb:0 and Grade V:26 (14.5%) . The complication rate was 5.3% and mortality rate was 0.8% in total 3336 surgical procedures. There was significantly higher mortality in complications due to patient related factors 23.4% (11/47), compared to technical factors 4.2% (2/48) and other factors 15.4% (13/84) (p value = 0.024). The mortality was significantly higher in the patients who required ICU care, 54% (20/37), in class B surgical procedures 22.4% (22/98) and those who developed complications after emergency procedures were 31% (14/45). The mortality was significantly higher in the patients who required medical intervention for various medical complications 30.1% (19/63) compared to those who required surgical intervention 8.4% (5/59) or were managed conservatively 3.5% (2/57) (p value = 0.0001).

Stapled haemorrhoidectomy in the operative treatment of grade III and IV haemorrhoids.

Stapled haemorrhoidectomy (SH) is a minimally invasive intervention that uses a stapling device which avoids the need for wounds in the sensitive anal area and reduces the pain after surgery. This study was undertaken in Nepal Medical College Teaching Hospital from January 2010 to December 2012 to evaluate the efficacy of this modality of treatment among patients (32) who presented in the Surgery OPD with grade III and grade IV haemorrhoids. The results of SH were evaluated by the relief of symptoms, severity of post operative pain, and complications of SH. Twenty five (78.1%) patients had grade III and 7 (21.9%) presented with grade IV hemorrhoids. The most frequent presentation reported in our study was bleeding per rectum with perianal prolapse. Mean operating time was 40-60 minutes whereas mean hospital stay was 1.9 days. Urinary retention was the most common complication found in 12 (37.5%) patients in the immediate post operative period. SH is a safe, rapid, and convenient surgical remedy for grade III and grade IV hemorrhoids with low rate of complications, minimal postoperative pain, and shorter hospital stay.

Study on responses after splenectomy for idiopathic thrombocytopenic purpura patients, Kathmandu, Nepal.

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by accelerated destruction of platelets due to the presence of platelet (Plt) auto antibodies and impaired production of platelets. Splenectomy is still the standard salvage therapy in cases refractory to corticosteroid therapy. Retrospectively we analyzed 34 patients with ITP that underwent splenectomy in the period May 2010 to March 2012 and have been followed for at least 12 months. All patients met the diagnostic criteria for ITP. The median age at diagnosis was 26 years (range: 14-55 years). Overall response rate to splenectomy after 1 year of follow up was 94.1%, with Complete response in 32 and no response or relapse in 2 (5.8%). Sex didn't influence the outcome after splenectomy in our group of patients. Only preoperative response to steroids (P value = 0.018) and post-operative platelet count (P value = 0.013) were found to be significant statistically. Splenectomy considered as safe and effective treatment for patients with ITP who failed to respond to firs-line treatment with corticosteroids. Management of patients who do not respond or relapse after splenectomy represent an important problem for further treatment due to low response rate to other treatment options.

Choledochoduodenostomy in the management of dilated common bile duct due to choledocholithiasis.

Choledochoduodenostomy (CDD) is the operative procedure for Choledocholithiasis in the presence of a dilated common bile duct (CBD). It has been reported as a most effective treatment of CBD stones than T-tube drainage but is regarded as a obsolete therapeutic method due to fears of higher morbidity, cholangitis, "sump" syndrome etc. This study was done prospectively to assess the aforementioned issues analyzing our two years (July 2009 - June 2011) experience.CDD was performed in 31 patients (22 females and 9 males) with aged 18 - 72 years. CBD stones were the only indications in all patients with 18 (45.1%) patients had cholangitis, 8 (35.4%) had cholecystitis and 5 (19.3%) had biliary colic. Abdominal sonogram revealed dilated CBD with single or multiple calculi. The diameter of CBD varies from 14 - 29mm with stone size being ranged from 10- 26mm.Early post operative complications were seen in 4 (12.9%) patients. Only one patient had recurrent cholangitis presented lately due to intrahepatic stones.CDD is a highly effective treatment for choledocholithiasis in all age group with low morbidity and mortality provided a wide anastomosis is accomplished.

Prevalence study of H. pylori infection in dyspeptic patients coming to Nepal Medical College Teaching Hospital, Jorpati, Kathmandu.

Helicobacter pylori (H. pylori) is one of the most common human infections worldwide particularly in the developing countries. It has been established as etiology of chronic gastritis and peptic ulcer disease, gastric adenocarcinoma and mucosal associated lymphoid tissue lymphoma (MALT). During this decade, there have been some reports showing a decline in global prevalence of H. pylori infection and peptic diseases including many Asian countries. Hence to determine prevalence of Helicobacter pylori infection in dyspeptic patients, this descriptive, non-interventional study was carried out at the Endoscopy sub-unit of the Surgery Department from April 2011 to February 2012. Three hundred nineteen dyspeptic patients (Male 161 and female 152) with a mean age of 20.12 years were examined for the presence of H. pylori infection by histology staining. The prevalence of H. pylori infection was 50.47%. The most common endoscopic findings was gastritis (47.6%) followed by normal findings 57 (17.87%). A total of 8.47% of gastric Ulcer, oesophagitis 5.64% and gastric cancer 0.94% were detected. All three cases of gastric cancer were positive for H. pylori infection. Among gastritis, H. pylori was observed in 67 (44%) cases and 18 out of 57 (5.6%) of normal gastric mucosa showed H. pylori. The endoscopic findings such as gastritis, gastric ulcer, duodenal ulcer and gastro duodenal reflux are significantly associated with H. pyloric infection. The prevalence of H. pylori infection is still high in peptic diseases. H. pylori infection is significantly correlated with peptic ulcer diseases than with non-ulcer dyspepsia. Further studies are required to establish the H. pylori positive cases with that of other tests such as serological detection of anti H. pylori antibody by ELISA/ICT and culture to establish a diagnosis quickly without any invasive method and institute proper management thus reducing morbidity.

Outcome analysis of breast cancer patients treated at Nepal Medical College.

Breast carcinoma is second most common malignancy among women in Nepal and is also still a killer carcinoma in our context. We are encountering with more cases of breast cancer, may be due to increase number of cases because of life style modification or due to more diagnostic facilities available in the country. Yet we most often encounter more advanced stage of breast carcinoma. In our study we had total of 21 patients who suffered from breast carcinoma. Among those patients most were elderly with mean age of 54.33 +/- 11.25 years. Among 21 patients, 13 patients were either of locally advanced type or with advanced breast carcinoma with metastasis. In our institution these patients were offered evidence based treatment as per their requirement. Since most of these patients are unaware of self breast examination and hence presented lately. Even though they were managed properly, 1 patient had local recurrence and 4 patients later presented with distant metastasis.

Inguinal herniotomy in children: a one year survey at Nepal Medical College Teaching Hospital.

This was a prospective study done at Nepal Medical College Teaching Hospital from July 2008 to June 2009 which covers our experience in inguinal herniotomy in children. Our study included 63inguinal hernia repairs in 61 children up to the age of 15 years. Out of 61 patients 2 had bilateral inguinal hernia and 59 had unilateral. Among 59 patients with unilateral hernias, 7 patients had emergency presentation. In children with unilateral hernias, it was found that it is more common at right side and regarding complication it is more common in emergency group. There were 5 recurrences and 5 wound infection among all patients.

The incidence of thyroid carcinoma in multinodular goiter: prospective study.

Thyroid carcinoma (TC) is a relatively rare tumour, but it represents the most frequent form of cancer of the endocrine glands. Epidemiologically ascertained risk factors are ionising radiation, the presence of thyroid adenoma and multinodular goiter (MNG). Multinodularity of goiter should no longer be considered an indicator of probable benign disease. A prospective analysis was performed on patients operated for multinodular Goiter at Nepal Medical College from January 2009 to November 2011, in order to establish the incidence of carcinoma. The results of this study, demonstrate that in 13.63 % of the patients operated for goiter, the presence of a carcinoma was noticed in the definitive histopathologic examination. Such incidence percentage of MNG is in accordance with the data reported in published reports. Thus, we conclude that the risk of malignancy in MNG has not to be underestimated, and that a dominant nodule in MNG should be valued as if it were a solitary nodule in an otherwise normal gland.

Comparative study of post operative wound infection following emergency lower segment caesarean section with and without the topical use of fusidic acid.

The study was undertaken to see the infection rate of wound following emergency caesarean section with and without the use of topical fusidic acid. The study was carried out at Himal Hospital from April 2006 to Jan. 2008. A total of 70 child bearing patients who underwent emergency caesarean sections were included. All of the patients were given absorbable subcuticular stitches. Out of the 70 patients, 35 patients had topical fusidic acid immediately after subcuticular stitches followed by dry dressing. The other 35 patients had simple dressing with povidone- iodine. Six patients (17.1%) out of the 35 patients who had dressing with povidone-iodine developed wound infection at the surgical site and only 1 patient (2.8%) out of the 35 patients with fusidic acid developed wound infection. The use of fusidic acid reduced the infection rate by six times. The relation of fusidic acid to wound infection was statistically significant (p = 0.0460).