Preliminary experience of angioscopy in femorodistal bypass.

During femorodistal bypass angioscopy can be used in vein graft preparation allowing valve lysis and the identification of tributaries under direct vision. A total of 30 patients have undergone angioscopic assisted femorodistal bypass using either an Olympus or Stortz system. Nineteen patients have undergone full vein mobilisation and valve lysis under direct vision. Eleven patients had in situ bypass with ligation of tributaries, identified by the angioscope, through small stab incisions. No evidence of fistula or retained valve cusps was found by subsequent duplex scanning and arteriography. One of these grafts failed at 6 days due to an unrecognised outflow stenosis. The mean hospital stay after operation for this latter group of patients was 5.2 days (range 4.4-6.0 days) compared with 9.5 days (8.6-10.3 days) in a historical group of 30 patients (P < 0.001). Angioscopy is a useful aid in the performance of femorodistal bypass. Early experience suggests that hospital stay may be reduced by angioscope assisted in situ femorodistal bypass because of the minimal dissection involved.     

Structure and Behavior in Hydrophilic Matrix Sustained Release Dosage Forms: 4. Studies of Water Mobility and Diffusion Coefficients in the Gel Layer of HPMC Tablets Using NMR Imaging

Purpose. The purpose of this study was to characterise the water mobility in the gel layer of hydrating HPMC tablets. Water mobility in the gel layer of different HPMCs was studied. Methods. NMR imaging, a non-invasive technique, has been used to measure the spatial distribution of self-diffusion coefficient (SDC) and T₂ relaxation times across the gel layer. Results. It has been shown that there is a water mobility gradient across the gel layer of HPMC tablets. Although SDC and T₂ relaxation times in the outer parts of the gel layer approached that of free water, in the inner parts they decreased progressively. Water mobility and SDC in the gel layer of different HPMCs appeared to vary with degree of substitution of the polymer and the lowest values were obtained across the gel layer of K4M tablets. Conclusions. Water mobility varies across the gel layer of hydrating HPMC tablets and it is dependent on the degree of substitution of the polymer.     

Hepatic histological findings after transplantation for chronic hepatitis B virus infection, including a unique pattern of fibrosing cholestatic hepatitis

Long-term follow-up of 27 patients with hepatitis B virus-related chronic liver disease treated by transplantation showed that 23 had hepatitis B virus recurrence. In 13 patients late changes in the grafts were similar to those described in other series: minor abnormalities in five cases, chronic active hepatitis in five cases and non-hepatitis B virus-related graft dysfunction in three cases. Three patients had incomplete histological follow-up. Analysis of the histological changes and viral antigen expression in six cases revealed a distinct and novel pattern termed fibrosing cholestatic hepatitis. Development of fibrosing cholestatic hepatitis was associated with rapidly progressive graft dysfunction. It is postulated that this pattern of fibrosing cholestatic hepatitis develops because of a high cytoplasmic expression of viral antigens, including HBsAg. The remaining case had some features of fibrosing cholestatic hepatitis. The main histological features of this unique syndrome include thin, perisinusoidal bands of fibrosis extending from portal tracts to surround plates of ductular-type epithelium; prominent cholestasis; ground-glass transformation; and ballooning of hepatocytes with cell loss and mild mixed inflammatory reaction.     

Pharmacokinetics of ciprofloxacin and vancomycin in patients with acute renal failure treated by continuous haemodialysis.

To determine appropriate doses of ciprofloxacin and vancomycin for septic patients with acute renal failure (ARF) treated by continuous arteriovenous and venovenous haemodialysis, (CAVHD/CVVHD), we performed pharmacokinetic studies in patients receiving these antibiotics. All patients were treated by CAVHD/CVVHD using Hospal AN69S 0.43 m2 filters and Fresenius 1.5% peritoneal dialysis fluid at dialysate flow rates (Qd) of 1 and 2 l/h. Patients received ciprofloxacin 200 mg i.v. 12-hourly (n = 6) or 8-hourly (n = 5); vancomycin 1 g i.v. was administered to 10 patients approximately every 48 h to maintain therapeutic plasma levels. For ciprofloxacin, volume of distribution (Vdarea) was 136.5 +/- 9.81, terminal elimination half-life (t1/2) 6.4 +/- 0.8 h, and total body clearance (TBC) 264.3 +/- 22.9 ml/min (mean +/- SEM). Mean sieving coefficient (S/C) was 0.76 +/- 0.05 and filter clearances at Qd 1 and 2 l/h were 16.2 +/- 1.9 and 19.9 +/- 1.1 ml/min respectively. For vancomycin, Vdarea was 60.7 +/- 5.11, t1/2 24.7 +/- 2.6 h and TBC 31.0 +/- 4.6 ml/min. Mean S/C was 0.66 +/- 0.08 and filter clearances at Qd 1 and 2 l/h 12.1 +/- 2.0 and 16.6 +/- 2.0 ml/min. These data suggest that patients with ARF treated by CAVHD/CVVHD should be given ciprofloxacin 200 mg i.v. 8-12-hourly and vancomycin every 48 h.     

Effects of rifampicin on the peripheral turnover kinetics of thyroid hormones in mice and in men

The induction of mixed function hepatic oxygenases by rifampicin is known to increase the metabolic clearance rate (MCR) of T4. By performing T3 and rT3 kinetics we have shown that rifampicin also increases the MCR of T3 and rT3. Using the fall of serum T4 during TSH suppression as an indirect marker of the production rate (PR) of T4, we have demonstrated that there was no major change in monodeiodination nor any shift to either 5'- or 5-monodeiodination. Rifampicin stimulates in mice the mixed function hepatic oxygenases. However, we were unable to increase hepatic deiodinase activity (deiodinase type I) in this species. It is therefore possible that the increased MCR of T4 in man is not mediated by an increased conversion rate either. As mixed function hepatic oxygenases are known to increase hepatic conjugation it is suggested that rifampicin increases the biliary excretion of iodothyronine conjugates.