The perforating branches of the P1 segment of the posterior cerebral artery

The perforating branches of the P1 segment of the posterior cerebral artery are vulnerable to injury. Because of their close proximity to the basilar artery, the vulnerability occurs especially during surgical interventions for vascular pathologies such as basilar apex aneurysms. Therefore, extensive knowledge of the microsurgical anatomy of this area is mandatory to prevent poor post-operative outcomes. We microscopically examined 28 P1 segments obtained from 14 adult fresh cadaver brains (6 silicone injected, 8 freshly examined). The P1 segments ranged between 2.8 mm and 12.2 mm (mean 6.8 mm) in length with a mean outer diameter of 1.85 mm (range 0.8–4.5 mm). All 94 thalamoperforating branches identified in 27 P1 segments (mean 3.35 branches per segment) arose from the postero-superior aspect of P1 and were the most proximally originating branch in nearly all specimens (96.4%). In addition in 28 P1s, 12 short circumflex arteries (42.8%; mean 0.42 branches per segment), 16 long circumflex arteries (57.1%; mean 0.57 branches per segment) and 10 medial posterior choroidal arteries (35.7%; mean 0.35 branches per segment) were identified and all originated from the posterior or postero-inferior surface of the P1 segment. When the P1 segment had more than one type of branch, it was the short circumflex arteries that were always more proximal in origin than the others. The medial posterior choroidal arteries were always more distal in origin. All three branches were not observed together in any of the P1 segments. The findings in this, and future, anatomical studies may help to reduce the post-surgical morbidity and mortality rates after surgery for posterior circulation aneurysms.     

Gabapentin therapy improves heart rate variability in diabetic patients with peripheral neuropathy

PurposeDiabetic cardiac neuropathy, which is characterized by reduced heart rate variability (HRV), frequently coexists with peripheral neuropathy. Gabapentin has been used for the treatment of diabetic neuropathy. We aimed to evaluate the possible effect of gabapentin treatment on autonomic function in patients with type 2 diabetes via HRV.MethodsThirty patients with type 2 diabetes mellitus and peripheral neuropathy and 28 age- and sex-matched healthy controls were consecutively registered. Each patient underwent HRV measurements, and diabetic patients were administered gabapentin. After 3 months of gabapentin therapy, HRV parameters were measured again.ResultsBaseline HRV parameters were blunted in patients with diabetes mellitus according to the controls [standard deviation of all NN intervals (SDNN, ms): 106.3±29.9 vs. 148.8±36.5, P=.001; power spectrum of the high-frequency band (HF, ms²): 133.6±98.3 to 231.4±197.6, P=.02; power spectrum of the low-frequency band (LF, ms²): 341.8±247.8 to 511.5±409.4, P=.048; LF/HF ratio: 3.3±2.4 to 2.6±1.5, P=.33]. After 3 months of treatment with gabapentin, some HRV parameters showed some improvement. SDNN (106.2±29.8 to 119.4 ± 25, P=.016) and HF (133.6±98.3 to 167.6±118.3, P=.021) increased significantly. LF/HF ratio decreased (from 3.3±2.4 to 2.3±1.9, P=.039) and LF remained unchanged (341.8±247.8 to 352.3±228.9, P=.88).ConclusionsTherapeutic doses of gabapentin not only alleviate neuropathic symptoms but also improve cardiac autonomic function in diabetic patients with peripheral neuropathy.     

Intrathecal catheterization after unintentional dural puncture during orthopedic surgery

Purpose

We investigated whether inserting an intrathecal catheter and leaving it in place for 24 h after an unintentional dural puncture in orthopedic patients reduced the incidence of post-dural puncture headache (PDPH).

Methods

The study consisted of 427 patients in whom a total of 21 unintentional dural punctures had occurred during orthopedic surgery performed between 2002 and 2006. Seven patients (phase I; evaluated retrospectively) each underwent placement of an epidural catheter at another level after dural puncture during the period January 2002 to February 2004. Fourteen patients (phase II; evaluated prospectively) received an epidural catheter through the dural tear after an unintentional dural puncture during the period February 2004–March 2006

Results

In phase I, 5 of the 7 patients experienced PDPH, and one required an epidural blood patch. In phase II, only one of the 14 patients complained of PDPH, which resolved after 48 h of medical therapy. No patient experienced paresthesia, neurologic or hemorrhagic complication, or infection.

Conclusion

Inserting an epidural catheter through the dural tear following an unintentional dural puncture and leaving it in place for 24 h significantly reduces the incidence of PDPH.     

Hospital cost analysis of management of patients with renal colic in the emergency department

Acute severe colicky pain in the flank region is termed as renal colic (RC), which is commonly diagnosed and treated in the emergency department (ED). The present study is designed to investigate the hospital costs of patients with RC admitted to the ED and factors affecting the figures. Retrospective analysis includes all patients diagnosed with RC following physical examination and X-ray, ultrasound, computed tomography together with laboratory investigations in the university-based ED between February 2007 and February 2009. The study included 574 patients eligible for the predefined criteria. Mean total hospital cost in patients admitted to the ED due to RC was calculated to be 55.77 Euro. The greatest contribution to the total cost was made by radiological investigations in the ED (40.5%) followed by treatment costs (19.7%). Size and location of the stone and stay times in the ED were the independent variables affecting the costs. The costs were higher as the stones were bigger and as they were more distal in the ureter. Renal stones were associated with the lowest hospital costs. Radiological investigations are the greatest contributors in the ED costs in patients with RC. Effective measures need to be undertaken to reduce resultant costs. Preventive measures as well as diagnostic and therapeutic procedures should be standardized in the ED in accordance with technological advances and also cost-effectiveness when appropriate.     

Assessment of the relationship between asymmetric dimethylarginine and severity of erectile dysfunction and coronary artery disease

The plasma concentration of asymmetrical dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, has been linked to endothelial dysfunction. We investigated the relation between plasma ADMA concentration and severity of erectile dysfunction (ED) and coronary artery disease (CAD). We measured plasma levels of ADMA in 92 male patients. Patients were divided into three groups: group 1 (n = 41), patients with ED and without CAD; group 2 (n = 29), patients with stable CAD; group 3 (n = 22), control group (patients without CAD or ED). Erectile function was evaluated by the erectile function domain of the international index of erectile function (IIEF-EFD) a validated 15-item self-administered questionnaire. Erectile function is specifically addressed by six questions that form the so-called erectile function domain of the questionnaire. Each question is scored 0–5. ED is defined as any value <26. Patients with CAD who have stable angina pectoris were selected after coronary angiography. ADMA was analyzed by ELISA method. Group 1 had significantly higher concentrations of plasma ADMA than groups 2 and 3 (respectively, 0.75 ± 0.40 vs. 0.50 ± 0.30, P = 0.013; 0.75 ± 0.40 vs. 0.50 ± 0.25, P = 0.021). There was negative correlation between ADMA and IIEF-EFD score in all groups (n = 92) (r = −0.322, P = 0.002). In a multiple logistic regression analysis adjusting for age, hyperlipidemia, ADMA remained independent predictor for severe ED. Odds ratio for plasma ADMA was 14.151 (1.101–181.940; P = 0.042). First of all, this study provides that ADMA concentrations are significantly higher in patients who have ED when compared to patients with CAD and controls. Second, there was a negative correlation between ADMA and severity of ED. Elevating levels of circulating ADMA is an independent risk factor for severe of ED, and ADMA may be a link between CAD and ED.     

Rosiglitazone,peroxisome proliferator receptor-gamma agonist,ameliorates gentamicin-induced nephrotoxicity in rats

Nephrotoxicity is a major complication of gentamicin (GEN), which is widely used in the treatment of severe gram-negative infections. Reactive oxygen spaces (ROS) are important mediators of gentamicin-induced nephrotoxicity. Peroxisome proliferator-activated receptors (PPARs) have different activities including antioxidant properties. This study was performed to investigate the protective role of PPAR-γ agonist against GEN-induced nephrotoxicity. Male Wistar Albino rats were randomly divided into the following four groups, each of which consisted of six animals: (1) control; (2) intraperitoneally injected with GEN for 14 consecutive days (100 mg/kg/day); (3) treatment with rosiglitazone (RSG) via nasogastric gavage (10 mg/kg/daily for 14 days); (4) treatment with GEN + RSG combination for 14 day. Rats were decapitated on the 15th day and kidneys were removed. Urine was collected for every 24 h for the determination of daily urine volume. Urea, creatinine, Na⁺ and K⁺ levels were measured in blood. Malondialdehyde (MDA), reduced glutathion (GSH), and nitric oxide (NO) levels along with glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) activities were determined in the renal tissue. Changes in body weight were recorded. GEN treatment was found to cause nephrotoxicity as evidenced by elevation of serum urea and creatinine levels. Renal impairment was also assessed by the renal histology. The significant decrease in GSH and increases in MDA and NO levels as well as a decrease in GSH-Px, CAT, and SOD activities indicated that GEN-induced renal damage was mediated through oxidative reactions. On the other hand, RSG administration protected kidney tissue against GEN-induced and free radical-mediated oxidative renal damage in rats.     

Rosuvastatin protects tissue perfusion in the experimental testicular torsion model

Recently, anti-inflammatory and tissue protective effects of statins have been shown independent from its anti-hyperlipidemic effect. It has been shown that one of the statins, rosuvastatin, may reduce ischemia/reperfusion (I/R)-induced tissue injury in the brain, intestines, and heart. We planned an experimental study to evaluate the effect of rosuvastatin on I/R injury encountered after the detorsion of the testicular torsion. Rats were divided into three groups. In group 1, testis basal blood flow (basal value) was measured with LASER Doppler flowmeter (LDF). Testis was relocated into the scrotum without torsion. Two and 3 h after the basal measurement, testis was brought out from the same incision, and the second (second value) and third (third value) testicular blood flow measurements were done, respectively. In group 2, after the measurement of basal value testicular torsion was created. Second and third value measurements were obtained with LDF at the end of the 2 h of testicular torsion just before the detorsion and 1 h after detorsion. In group 3, same procedures in torsion/detorsion group were repeated in this group, but 10 mg/kg rosuvastatin was injected intraperitoneally 30 min before detorsion. Second values in groups 2 and 3 were significantly lower than group 1. Third values were significantly low in group 2 compared to groups 1 and 3. Regarding the third measurement, there was no significant difference between the groups 1 and 3. Tissue injury is closely related with condition of microvascular perfusion after I/R. Rosuvastatin can protect tissue perfusion in the experimental testicular torsion model.     

Evidence for waning of latency in a cohort study of tuberculosis

Background  

To investigate how the risk of active tuberculosis disease is influenced by time since original infection and to determine whether the risk of reactivation of tuberculosis increases or decreases with age.