Involvement of nitric oxide pathway in the acute anticonvulsant effect of melatonin in mice

Melatonin, the major hormone produced by the pineal gland, is shown to have anticonvulsant effects. Nitric oxide (NO) is a known mediator in seizure susceptibility modulation. In the present study, the involvement of NO pathway in the anticonvulsant effect of melatonin in pentylenetetrazole (PTZ)-induced clonic seizures was investigated in mice. Acute intraperitoneal administration of melatonin (40 and 80 mg/kg) significantly increased the clonic seizure threshold induced by intravenous administration of PTZ. This effect was observed as soon as 1 min after injection and lasted for 30 min with a peak effect at 3 min after melatonin administration. Combination of per se non-effective doses of melatonin (10 and 20 mg/kg) and nitric oxide synthase (NOS) substrate L-arginine (30, 60 mg/kg) showed a significant anticonvulsant activity. This effect was reversed by NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg), implying an NO-dependent mechanism for melatonin effect. Pretreatment with L-NAME (30 mg/kg) and N(G)-nitro-L-arginine (L-NNA, 10 mg/kg) inhibited the anticonvulsant property of melatonin (40 and 80 mg/kg) and melatonin 40 mg/kg, respectively. Specific inducible NOS (iNOS) inhibitor aminoguanidine (100 and 300 mg/kg) did not affect the anticonvulsant effect of melatonin, excluding the role of iNOS in this phenomenon, while pretreatment of with 7-NI (50 mg/kg), a preferential neuronal NOS inhibitor, reversed this effect. The present data show an anticonvulsant effect for melatonin in i.v. PTZ seizure paradigm, which may be mediated via NO/L-arginine pathway by constitutively expressed NOS.     

A rare complication of forgotten ureteral stent

A 35 years old lady presented with history of something coming out of the genitalia for the last 5 days. She also had history of pain in the left lumbar region which was initially investigated but the patient did not follow-up. About 15 years ago she also underwent left ureteric reimplantation. On examination, a stick like tube was protruding out of the urethral meatus which was fixed to the underlying vesical calculus. The calculus was evident radiologically and on ultrasound. The projecting portion of the stick like tube was cut and the vesical calculus with the inner portion of the tube was removed by open procedure. On evaluation of the specimen, it was found that the vesical calculus was fixed to the plastic tube which had concretions around it. This plastic tube had been placed after the ureteric reimplantation done 15 years ago and the patient was not aware of it.     

Flexion contracture following primary total knee arthroplasty: risk factors and outcomes

Function and satisfaction after total knee arthroplasty (TKA) are partially linked to postoperative range of motion (ROM). Fixed flexion contracture is a recognized complication of TKA that reduces ROM and is a source of morbidity for patients. This study aimed to identify preoperative risk factors for developing fixed flexion contracture following TKA and to quantify the effect of fixed flexion contracture on outcomes (Oxford knee score 12-60 and patient satisfaction) at 2 years. Pre-, intra-, and postoperative data for 811 TKAs were retrospectively reviewed. At 2 years postoperatively, the incidence of fixed flexion contracture was 3.6%. Men were 2.6 times more likely than women to have fixed flexion contracture (P=.012), and patients with preimplant fixed flexion contracture were 2.3 times more likely than those without to have fixed flexion contracture (P=.028). Increasing age was associated with an increased rate of fixed flexion contracture (P=.02). Body mass index was not a risk factor (P=.968). Incidence of fixed flexion contracture for those undergoing computer navigated TKA was 3.9% compared with 3.4% for those having conventional surgery (P=.711). Patients with fixed flexion contracture had poorer outcomes with a median [interquartile range] Oxford Knee Score of 25 [15] compared with 20 [11] for those without (P=.003) and lower patient satisfaction (P=.036). These results support existing literature for incidence of fixed flexion contracture after TKA, risk factors, and outcomes, indicating that these figures can be extrapolated to a wide population. They also clarify a previously contentious point by excluding body mass index as a risk factor.     

Transplantation of solid organs procured from influenza A H1N1 infected donors

Following the influenza A H1N1 (swine flu) pandemic, there remains little evidence informing the safety of transplanting organs from donors suspected or diagnosed with H1N1. Limited guidelines from the major transplant societies leave the use of such organs at the discretion of individual transplant centres, and practice varies considerably both nationally and internationally. We present the largest published series of outcome following transplantation of organs from H1N1 positive donors and demonstrate that these organs can be transplanted safely and with good short-term outcome. We discuss our local policy for treatment of recipients with Oseltamivir.     

Why large-head metal-on-metal hip replacements are painful: the anatomical basis of psoas impingement on the femoral head-neck junction

Large-head metal-on-metal total hip replacement has a failure rate of almost 8% at five years, three times the revision rate of conventional hip replacement. Unexplained pain remains a feature of this type of arthroplasty. All designs of the femoral component of large-head metal-on-metal total hip replacements share a unique characteristic: a subtended angle of 120° defining the proportion of a sphere that the head represents. Using MRI, we measured the contact area of the iliopsoas tendon on the femoral head in sagittal reconstruction of 20 hips of patients with symptomatic femoroacetabular impingement. We also measured the articular extent of the femoral head on 40 normal hips and ten with cam-type deformities. Finally, we performed virtual hip resurfacing on normal and cam-type hips, avoiding overhang of the metal rim inferomedially. The articular surface of the femoral head has a subtended angle of 120° anteriorly and posteriorly, but only 100° medially. Virtual surgery in a normally shaped femoral head showed a 20° skirt of metal protruding medially where iliopsoas articulates. The excessive extent of the large-diameter femoral components may cause iliopsoas impingement independently of the acetabular component. This may be the cause of postoperative pain with these implants.     

Determination of natural radioactivity in building materials used in the Rawalpindi/Islamabad area by gamma-ray spectrometry and instrumental neutron activation analysis.

Samples of sand and manufactured building materials collected from the Rawalpindi/Islamabad area have been analyzed for the primordial natural radionuclides 238U, 232Th and 40K using gamma-ray spectrometry. The uranium and thorium contents have also been determined by instrumental neutron activation analysis (INAA). The specific activities of these radionuclides in the samples are compared with those of the world averages for soil. The comparison shows that, of the nine samples analyzed, only the three brick samples have higher activities than the world averages for soil. The specific activities in these materials, having a radium equivalent activity of less than 370 Bq kg-1, when evaluated for radiological effects show that all materials meet the external gamma-ray dose limitation of 1.5 mSv y-1. The gamma-spectrometric and INAA techniques complemented each other well in this study.     

Listeria monocytogenes peritonitis in a patient on peritoneal dialysis: a case report and review of the literature

Listeria monocytogenes (LM) is one of the rare microorganisms causing peritonitis in peritoneal dialysis (PD) patients. We report a sporadic case of peritonitis caused by LM in a young female PD patient with lupus receiving corticosteroid therapy, who presented with abdominal pain, cloudy PD effluent, nausea, and conjunctivitis. The effluent showed a high PD effluent white cell count and monocytosis, and gram staining showed gram-positive bacilli in single or short chains and PD effluent culture grew LM. She was treated successfully with beta lactum antibiotics. LM peritonitis should be suspected if a patient presents with gram-positive bacilli and monocytosis in dialysis effluent.     

A very rare case of single coronary artery anomaly, with left anterior descending and left circumflex arteries originating separately from proximal right coronary artery

Coronary artery anomalies are rare, with the reported prevalence of 0.2% to 1% in routine angiographic studies. Among them, presence of a single coronary artery is one of the rarest anomalies, comprising less than 3% of all coronary anomalies. In this article we report a case of single coronary artery anomaly with left anterior descending and left circumflex arteries arising separately from proximal right coronary artery, and left anterior descending artery reaching atrioventricular sulcus by passing between aortic and pulmonary artery trunci. The patient underwent off-pump coronary artery bypass grafting and is currently symptom-free.