HAART and the liver: friend or foe?

The overall effect of HAART on the liver is the result of the balance between hepatotoxicity and the consequences of immunoreconstitution on the evolution of HIV-associated liver diseases, particularly viral hepatitis. HAART may lead to the emergence of acute toxic hepatitis, steatosis, steatohepatitis, liver fibrosis, and noncirrhotic portal hypertension. On the other hand, HAART use has been associated with slower fibrosis progression in HIV/HCV-coinfected patients in most studies dealing with this issue. As well, an improvement of the clinical outcome of liver disease has been reported in patients taking HAART. For these reasons, the short- and mid-term effects of HAART on the liver are mostly beneficial.     

Unilateral spinal anaesthesia for outpatient surgery: a comparison between hyperbaric bupivacaine and bupivacaine–clonidine combination

Backround: Low-dose hyperbaric bupivacaine has been used to produce unilateral spinal anaesthesia for outpatient surgery. Unilateral spinal anaesthesia is associated with reduction of hypotension, faster recovery and increased patient satisfaction. Small doses of clonidine have shown effectiveness in intensifying spinal anaesthesia. We investigated the effect of adding 15 μg of clonidine to 5 mg hyperbaric bupivacaine on unilaterality.
Methods: Sixty patients undergoing outpatient knee arthroscopy were randomly allocated to receive either 1.2 ml (6 mg) of hyperbaric bupivacaine or a 1.2 ml solution containing 1.0 ml (5 mg) hyperbaric bupivacaine, 0.1 ml (75 μg) clonidine and 0.1 ml sterile water. The motor block was assessed by a modified Bromage scale and the sensory block by a pinprick.
Results: There was a significant difference in the spread of anaesthesia between the operated and contralateral sides in both groups. Seventy-seven per cent of the blocks were unilateral in group B and 73% in group B-C. There was no significant difference between the groups, in unilaterality. The motor block was prolonged in group B-C but it did not affect home-readiness. Patients receiving clonidine needed more vasopressors. There was a significant difference in blood pressures between the groups, being lower in group B-C after 1 h 45 min.
Conclusion: Using 5 mg hyperbaric bupivacaine with 15 μg of clonidine, the unilaterality can be achieved and spinal anaesthesia intensified without affecting home-readiness. More vasopressors are needed in the beginning, but after the surgery patients experienced less pain.     

霍奇金淋巴瘤序贯化疗疗效观察

 目的 探讨初治的霍奇金淋巴瘤（HL）更为安全有效的化疗方案。方法 对2000年10月至2005年10月收治的Ⅱ～Ⅳ期HL患者97例,采用随机分组的方法分为A、B两组。A组48例,采用ABVD方案（多柔比星+博莱霉素+长春新碱+氮烯咪胺）化疗8个周期;B组49例,前4个周期采用ABVD方案化疗,后4个周期采用COEP方案（环磷酰胺+长春新碱+依托泊苷+泼尼松）化疗。两组患者化疗结束后均由同一位放疗科医师根据具体情况给予放疗,制定放疗方案时不受A、B分组的影响。结果 A组8个周期ABVD方案化疗结束后完全缓解（CR）率为87.5 %（43／48）,1、2、3年总生存率分别为：95.8 %（46／48）,90.0 %（36／40）,79.3 %（23／29）。B组8个周期化疗结束后CR率为89.8 %（44／49）,1、2、3年总生存率分别为：93.9 %（46／49）,92.7 %（38／41）,80.0 %（24／30）。A、B两组比较,CR率1、2、3年总生存率差异均无统计学意义。A、B两组比较,B组患者心肌损伤、肺纤维化发生率差异有统计学意义。结论 HL采用COEP方案4个周期、ABVD方案4个周期序贯化疗较单用ABVD方案8个周期化疗的缓解率和疗效相似,而B组心肌损害、肺纤维化的发生率减低。     

Diagnosis of Atrial Fibrillation Using Electrograms from Chronic Leads: Evaluation of Computer Algorithms

This study compares the performance of three detection algorithms for the recognition of atrial fibrillation in chronic pacing leads. Multiple serial recordings were obtained of wideband and filtered electrograms from chronic atrial and ventricular leads in dogs for a period up to 55 days following implantation. Each dog was recorded in sinus rhythm and induced atrial fibrillation. Four days were chosen for processing: The day of implantation and a day in the first, second or third, and fifth weeks. Three signal processing methods were assessed for performance in detection of atrial fibrillation: software recognition of rate with automatic threshold control, amplitude distribution, and frequency spectral analysis. A software trigger for rate determination was adjusted to thresholds of 10, 20, and 30% of maximum baseline-to-peak amplitude. At 10%, a rate boundary anywhere between 420 and 560 beats per minute (bpm) perfectly separated atrial fibrillation from sinus rhythm even though atrial electrograms were contaminated with large QRS deflections and double-sensing was present. At 20% and 30%, a rate boundary around 300 bpm could be used, but sensitivity and specificity were reduced to 90%. In amplitude distribution analysis, a percent of time within a baseline window provided perfect separation of atrial fibrillation from sinus rhythm. In all cases, the signal was within this window less than 43% of the time in atrial fibrillation, and more than 43% in sinus rhythm. In spectral analysis, frequency bands were examined for power content. In the 6 to 30 Hz band atrial fibrillation contained the greater power. Choosing 58% of total power as a discriminant, sensitivity and specificity of atrial fibrillation detection were 100% and 95% respectively.     

Phenytoin dosage adjustment in Saudi epileptics: utilization of steady-state pharmacokinetic parameters

We determined the Michaelis-Menten parameters (Vmax and Km) in 271 Saudi epileptic patients having generalized tonic-clonic seizures and who were treated with phenytoin (PHT) using high pressure liquid chromatography (HPLC). The patients comprised 150 (55.4%) males and 121 (44.6%) females, with a mean age of 31.7 years (SD = 18.5). The mean Vmax for subjects less than 16 years of age was 10.35 mg/kg/day (SD = 0.73, range = 3.77-17.01), while for those above 16 years, the mean value was 7.99 mg/kg/day (SD = 0.15, range = 3.68-15.95). The difference was statistically significant (P < 0.001). Vmax was positively correlated with weight (r = 0.953), but negative with age (r = -0.903). Km values ranged from 1.01-20.87 mg/litre. The adult Km mean of 6.52 mg/l (SD = 0.24) was significantly higher than the mean of 4.79 mg/l (SD = 0.40) for pediatric patients (P < 0.01), but Km was correlated neither with age nor with weight. Our results showed no difference between the predicted and observed serum PHT concentrations in both the pediatric and adult patients when the respective age group Km and Vmax values were used to adjust PHT doses. The pediatric cases, however, required 30% more PHT per kilogram of body weight than the adults for the achievement of similar serum concentrations.     

Comparative bioavailability study of cefixime (equivalent to 100 mg/5 ml) suspension (Winex vs Suprax) in healthy male volunteers

This investigation was carried out to evaluate the bioavailability of a new suspension formulation of cefixime (100 mg/5 ml), Winex, relative to the reference product, Suprax (100 mg/5 ml) suspension. The bio-availability study was carried out in 24 healthy male volunteers who received a single oral dose (200 mg) of the test (A) and the reference (B) products on 2 treatment days after an overnight fast of at least 10 hours. The treatment periods were separated by a one-week washout period. A randomized, balanced two-way crossover design was used. After dosing, serial blood samples were collected over a period of 16 hours. Plasma concentrations of cefixime were analyzed using a sensitive high-performance liquid chromatographic assay. The pharmacokinetic parameters for cefixime were determined using standard non-compartmental method. The parameters AUC(0-t), AUC(0-infinity), Cmax, Kel, t1/2 and Cmax/AUC(0-infinity) were analyzed statistically using raw and log-transformed data. The time to maximum concentration (tmax) was analyzed using raw data. The parametric 90% confidence intervals of the mean values of the pnfinity harmacokinetic parameters: AUC(0-t), AUC(0-infinity) Cmax, and Cmax/AUC(0-infinity) were within the range 80 - 125% which is acceptable for bioequivalence (using log-transformed data). The calculated 90% confidence intervals based on the ANOVA analysis for the mean test/reference ratios of AUC(0-t), AUC(0-infinity), Cmax, and Cmax/AUC(0-infinity) were 88.93 - 107.10%, 89.09 - 107.11%, 89.63 - 108.58% and 96.85 - 105.29%, respectively. The test formulation was found bioequivalent to the reference formulation with regard to AUC(0-t), AUC(0-infinity), and Cmax using the Schuirmann's two one-sided t-tests. Therefore, the two formulations were considered to be bioequivalent.     

Serum Vitamin A Levels in Mothers and Their Breast-Fed Term Infants with or without Supplemental Vitamin A

ABSTRACT. Serum concentrations of vitamin A were measured in term infants ( n =72) and their mothers at delivery and after 20 weeks of breast-feeding ( n =48). During the 20 weeks the infants received either no supplemental vitamin A (but the mothers were given 3000 IU vitamin A daily) ( n =16) or a daily vitamin A supplementation of 600 ( n =17) or 1500 IU ( n =15). After 20 weeks of breast-feeding the vitamin A levels in the unsupplemented infants were similar to those at birth. The infants supplemented either with 600 or 1500 IU had higher vitamin A serum levels than at birth ( p <0.01), however, there was no difference between the two supplemented groups. During lactation, the serum vitamin A concentrations of the mothers increased significantly in all groups with or without vitamin A supplementation.