Negative regulation of Lyn protein-tyrosine kinase by c-Cbl ubiquitin-protein ligase in Fc epsilon RI-mediated mast cell activation

BACKGROUND: Recent studies have demonstrated that c-Cbl functions as a ubiquitin-protein ligase toward immune receptors and non-receptor protein-tyrosine kinase Syk by facilitating their ubiquitination and subsequent targeting to proteasomes. However, it was not clear whether Src family kinase Lyn is regulated by the Cbl family of ubiquitin-protein ligases. RESULTS: Aggregation of the high affinity IgE receptor (Fc epsilon RI) induces the rapid ubiquitination of Lyn in rat basophilic leukaemia RBL-2H3 cells. Treatment of cells with a proteasome inhibitor enhances the ubiquitination of Lyn. Stimulation of Fc epsilon RI results in the association of Lyn with c-Cbl and Cbl-b, both of which then become tyrosine phosphorylated. Co-transfection study shows that both c-Cbl and Cbl-b could induce the ubiquitination of activated Lyn in COS cells. Furthermore, over-expression of membrane-anchored form of c-Cbl inhibits the Fc epsilon RI-mediated degranulation and cytokine gene production in RBL-2H3 cells by the down-regulation of the kinase activity of Lyn through the enhanced ubiquitination. CONCLUSIONS: These results demonstrate that Lyn is down-regulated by c-Cbl-mediated ubiquitination and subsequent degradation in proteasome after Fc epsilon RI stimulation in mast cells. Targeting of c-Cbl in the lipid raft results in the inhibition of Fc epsilon RI-mediated mast cell activation.     

Resistance pattern of bacteria isolated from acute respiratory tract infection (ARI) cases

Out of 350 acute respiratory tract infection (ARI) patients 110 (31.4%) were positive on culture. Among then (35.5%) yielded from upper respiratory tract infection (URI) and 64.5% yielded from lower respiratory tract infection (LRI). Predominant bacterial isolates from URI were Staph aureus (12.4%) and Strepto. pyogen (9.8%) whereas predominant agent from LRI were Strepto. pneumoniae (14.7%) and Haemophilus influenzae (8.6%). Capsular typing by polymerase chain reaction (PCR) and type specific antisera revealed that 64.7% of the isolates were type-b and rest were non-b. The most frequent resistance pattern of H. influenzae was found resistant to penicillin-ampicillin (64.7%) followed by SMX-TMP (14.7%) and tetracycline (5.9%). Among penicillin-ampicillin resistant strains, 81.8% were beta lectamase positive and 18.2% were beta lectamase negative. Among beta lectamase positive strains 66.7% were capsular type-b and 33.3% were non-b, had MICS < or = 8 microgram/ml. and < or = 4 microgram/ml. respectively. 5.9% strains of Strepto. pneumoniae was found resistant to SMX-TMP, 5.9% to penicillin-ampicillin and 2.9% to cephalexin. Common resistance pattern of Staph aureus was penicillin-ampicillin (60%), SMX-TMP (37.2%) and tetracycline-erythromycine-cephalexin (11.4%). Strepto. pyogen was found resistant to tetracycline in 12.2% cases and to SMX-TMP in 8.3% cases.     

Effect of amino acids and dipeptides on accumulation of ammonia in the medium during <Emphasis Type="Italic">in vitro</Emphasis> maturation and fertilization of porcine oocytes

Aim:  The present study was designed to investigate the effect of amino acids and their dipeptides on the accumulation of ammonia in the medium during in vitro maturation (IVM) and in vitro fertilization (IVF) of porcine oocytes.
Methods:  The IVM and IVF media were modified North Carolina State University-37 solution and modified Tyrode's albumin lactate pyruvate, respectively. Porcine oocytes were matured in IVM medium containing 75–2400 µmol ammonia. Amino acids (1.0 mmol) or their dipeptides (2.0 mmol) related to the urea cycle were added individually to the IVM and IVF media containing 300 µmol ammonia. Oocyte maturation and fertilization were assessed using acetic–orcein staining, and the accumulation of ammonia in the media was measured using the indophenol method.
Results:  Percentages of metaphase II (MII) were adversely affected ( P <  0.05) by ≥300 µmol concentrations of ammonia in the IVM medium. In the presence of 300 µmol ammonia in the IVM and IVF media, glutamic acid, l -alanyl-L-glutamine (AlaGln), l -glycyl-L-glutamine (GlyGln) and AlaGln + GlyGln showed the highest rate ( P <  0.05) of MII, monospermic fertilization, and the lowest rate ( P <  0.05) of ammonia accumulation in the media.
Conclusion:  AlaGln and GlyGln in IVM and IVF media were more stable and effective than the individual amino acids in reducing the accumulation of ammonia, and increased the rate of porcine oocyte MII and monospermic fertilization in vitro . (Reprod Med Biol 2007; 6 : 165–170)     

Congenital sideroblastic anemia treated as thalassemia major

Sideroblastic anemia is a rare cause of microcytic hypochromic anemia. In Bangladesh, most common causes of microcytic anemia are iron deficiency anemia, anemia of chronic diseases and thalassemia. Serum ferritin is usually done to differentiate them. If serum ferritin is low, the diagnosis of iron deficiency is entertained. When serum ferritin is raised but erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are normal - anemia of chronic disease is excluded. The next investigation is Hb-electrophoresis. Normal Hb-electroporesis excludes thalassemia. Then bone marrow examination with iron stain is done for the diagnosis of sideroblastic anemia. Here we report a case of a 14 year old girl presenting with intermittent leg pain and anemia. Her blood flim showed microcytic hypochromic anemia with raised serum ferritin and normal Hb-electroporesis. Initially she was labeled as a case of unusual type of thalassemia and treated with blood transfusion. Finally bone marrow examination with iron stain was done and she was diagnosed as a case of congenital sideroblastic anemia. We reviewed the literature and discussed the management as well.     

Comparative study on methotrexate and hydroxychloroquine in the treatment of rheumatoid arthritis

This study was done to see the efficacy and tolerability of methotrexate and hydroxychloroquine in the Treatment of Rheumatoid Arthritis. It was an open label controlled clinical trial, done in Mymensingh Medical college hospital. Fifty six patients were selected by random sampling method, 28 were included in methotrexate group and another 28 for hydroxychloroquine group using inclusion & exclusion criteria. Primary efficacy variables (DAS28, daily naproxen), secondary efficacy variables, and safety measurement variables studied both clinically & laboratory investigations. The data were analyzed by computer with the help of SPSS. The student's t test was used as test of significant. The mean age of the patients at diagnosis was almost identically distributed between methotrexate and hydroxychloroquine group (41.7±12.2 vs. 42.9±9.2 years, p=0.659). Disease activity at baseline was found to be almost homogeneous to each group except CRP which was observed to be significantly higher in methotrexate group than hydroxychloroquine group (p<0.001). Disease activity at 1 month of treatment reduced in the methotrexate group than those in hydroxychloroquine group (p<0.05 in each case). After 3 and 6 months of treatment, disease activity decreased significantly in both groups (p<0.001 and p<0.05 respectively). The average daily dose of NSAID (Naproxen) decreased significantly (p<0.001). Safety variables at 6 month were within normal physiological ranges and did not differ in groups (p>0.05) indicating that both methotrexate and hydroxychloroquine were effective and safe to use in rheumatoid arthritis. The difference in the incidence of adverse effects, total or individual, was almost nil.     

Nasal metastases from renal cell carcinoma are associated with Memorial Sloan-Kettering Cancer Center poor-prognosis classification

Unusual sites of metastases are recognized in patients with renal cell carcinoma (RCC). However, the prognostic implications of these sites are not well understood. We used the Memorial Sloan-Kettering Cancer Center (MSKCC) risk classification for metastatic RCC to evaluate 912 consecutive patients with RCC managed at the Singapore General Hospital between 1990 and 2009. Among these patients, 301 had metastases either at diagnosis or during the course of illness. Nasal metastases, all arising from clear cell RCC, were identified histologically in 4 patients (1.3% of those with metastasis). All 4 patients were classified as MSKCC poor prognosis by current risk criteria. Nasal metastases were significantly associated with lung and bone metastases. The frequency of nasal metastases in patients with metastatic RCC is about 1%, occurring predominantly in patients with clear cell RCC. Nasal metastases are associated with poor prognosis as estimated by the MSKCC risk classification, with attendant implications for selection of targeted therapy, and are usually associated with multi-organ dissemination, including concurrent lung and bone involvement.     

Retrograde jejunogastric intussusception (JGI) with strangulation following previous gastrojejunostomy

Jejunogastric intussusception is a rare but potentially very serious complication of gastrectomy or gastrojejunostomy. To avoid mortality early diagnosis and prompt surgical intervention is mandatory. A young man presented with epigastric pain and bilous vomiting followed by haematemesis 15 years after vagotomy & gastrojejunostomy for chronic duodenal ulcer. At presentation the patient was in shock and an emergency laparotomy was done after resuscitation. At laparotomy a retrograde type II JGI was found and managed by resection of the affected segment and partial gastrectomy and jejuno - jejunostomy with closure of the duodenal stump. Postoperative recovery was uneventful. Retrograde JGI is a rare condition and only less than 200 cases have been reported since its first report. Clinical picture of acute intestinal obstruction with suspicion about the condition in patients having a past history of gastrojejunostomy makes the elusive diagnosis definite and demands early surgery to reduce the grave consequences of the disease.