Piperacillin in the treatment of urinary tract infections

The ureidopenicillin piperacillin was given to 20 patients with urinary tract infections. The infecting microbes all had a minimum inhibitory concentration below 0.6 microgram/ml. One strain of Staphylococcus aureus produced beta-lactamase. All patients were freed of their microbes at the end of 7 days therapy. 1--2 weeks after the end of therapy, 1 relapsed and 3 had superinfections. Among the 16 who were without bacteria or leucocyturia after 1--2 weeks, 2 exhibited a superinfection 4--6 weeks after the end of therapy.     

Pharmacokinetics of brodimoprim in serum and skin blister fluid

Following 400 mg brodimoprim given orally to 8 volunteers, the peaks of the mean concentration curves were 3.2 +/- 1.0 mg/l in serum and 1.0 +/- 0.2 mg/l (+/- SEM) in skin blister fluid. The terminal half-lives were 25.9 +/- 2.2 h and 42.2 +/- 6.5 h in serum and blister fluid, respectively. The area under the concentration-versus-time curve for blister fluid was 73% of serum value, and the mean recovery of bioactive drug in urine during 24 h was 3.4%. Considering the minimal inhibitory concentrations of potential target organisms and the slow elimination, the results suggest that brodimoprim may be useful in the treatment of infections, and that dosage once a day may be sufficient.     

Crystalluria and ciprofloxacin, influence of urinary pH and hydration

Ciprofloxacin is one of the newer 4-quinolones. It combines a high antibacterial activity and a broad spectrum with favourable pharmacokinetic properties. The present study was designed to detect the influence of urinary pH and fluid consumption on crystalluria. Six healthy volunteers aged 25-41 years, 3 of each sex, participated in the study. Single doses of 1,000 and 500 mg of ciprofloxacin were given orally. The urinary pH was varied by giving each subject three different diets: a regular diet, a diet supplemented by ammonium chloride to acidify urine, and a diet supplemented by sodium bicarbonate to obtain alkaline urine. The urine volume and pH were measured and microscopically examined at 37 degrees C immediately after voiding. After the very high dose of 1,000 mg ciprofloxacin the regular diet regimen led to crystalluria in only one subject. Even with this high dose, but with the acidifying regimen, no crystals were observed in any one of the volunteers. When bicarbonate was supplemented 5 to 6 volunteers presented crystals in 22 of the 36 urine samples. 21 of the crystalluric urine samples showed a pH greater than or equal to 7.3. After the usual 500-mg dose and regular diet no crystals were observed at all; only in 3 subjects who received bicarbonate supplement crystals have been seen. In the urine of two subjects crystals emerged 'ex vivo' after some hours of storage at both 37 degrees C and room temperature; these results show the importance of sediment observation at 37 degrees C immediately after voiding to differentiate between real and 'ex vivo' crystalluria. Results of different examinations permit the conclusion that the crystals contain mostly unchanged ciprofloxacin as major component and magnesium as characteristic element. Participation of the metabolite 2 in the crystal formation cannot be excluded. No significant change was observed in blood counts and blood chemistry of any subject. Urinalysis showed no modifications except the eventual presence of the typical drug-related crystals. Hematuria never occurred.     

Transintestinal elimination of ciprofloxacin

This study elucidates the routes of elimination of ciprofloxacin and its metabolites in two groups of 5 subjects each, one of healthy volunteers, the other of patients with severe renal failure having a creatinine clearance of 12 ml/min (range 8-16 ml/min). Each subject received one dose of 200 mg ciprofloxacin infused intravenously over 30 min. In an effort to recover the total dose administered, all urine and faeces were collected for the 7 days following dosing. Blood was collected at set intervals after dosing. Serum, urine, and faeces were assayed by high-pressure liquid chromatography for ciprofloxacin and metabolites. The ciprofloxacin serum half-life in healthy volunteers was 3.9 +/- 0.4 h and in patients with marked renal failure 11.2 +/- 2.5 h. The total amount of ciprofloxacin recovered in urine fell by a multiple of 3.4 from 65.3 +/- 10.7% in healthy subjects to 19.0 +/- 15.9% in patients with renal failure, and the metabolites from 12.2 +/- 2.3% in the former group to 5.8 +/- 5.1% in the latter. In contrast, the amount of ciprofloxacin eliminated in faeces increased, by a similar factor, from 11.4 +/- 2.6% in healthy subjects to 37.2 +/- 12.5% in patients with renal failure. The amount of metabolites in faeces increased analogously from 7.3 +/- 1.6 to 26.2 +/- 6.5%. Since ciprofloxacin was administered intravenously and biliary elimination of the drug and its metabolites is negligible, we propose that elimination by faeces is due primarily to transintestinal elimination. This study demonstrates that transintestinal elimination of ciprofloxacin serves as an extrarenal safety factor compensating for reduced elimination by the renal route.     

Assay of cefotaxime by high-pressure-liquid chromatography

A high-pressure-liquid chromatographic (HPLC) procedure for quantitative assay of cefotaxime (CT) and its major metabolite in serum of normal individuals, desacetyl cefotaxime (DACT), is described. It employs Lichrosorb RP-8, elution with phosphoric-acid-methanol and UV absorption at 310 nm. The method is optimized for cefotaxime and allows differentiation between the parent compound and the biotransformation product DACT. The lower assay sensitivity level of CT and DACT is 0.3 microgram/ml. Correlation between HPLC and microbiological assay with Escherichia coli or Proteus rettgeri of pooled serum with CT added is r = 0.99. The method is rapid; processing of one sample takes 17 min. Use of HPLC avoids the errors of microbiological assays which derived from the presence in patient sera of different ratios of CT and DACT. The apparent rate of serum elimination is linearly related to the sensitivity of the microbial assay indicator strain to DACT. There is synergistic antibacterial activity between CT and DACT regardless of relative minimum inhibitory concentrations of the agents.     

IMP dehydrogenase basal activity in MOLT-4 human leukaemia cells is altered by mycophenolic acid and 6-thioguanosine

OBJECTIVE: Depletion of guanine and deoxyguanine nucleotides by inhibition of inosine 5'-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) or introduction of 6-thioguanine nucleotide antimetabolites are two principles of retarding cell proliferation by interference with the cellular purine nucleotide pool. IMPDH activity may be a promising pharmacodynamic biomarker during immunosuppressive and anticancer pharmacotherapy. The aim of the study was to investigate the impact of mycophenolic acid (MPA) and 6-thioguanosine (tGuO) on IMPDH basal activity. MATERIAL AND METHODS: We studied the IMPDH basal activity (i.e. the enzyme activity following inhibitor exposure, but measured in absence of the inhibitor) in response to increasing concentrations of the IMPDH inhibitor MPA and the antimetabolite tGuO in MOLT-4 human leukaemia cells. In parallel, IMPDH gene expression and cellular purine nucleotide concentrations were examined. RESULTS: A biphasic concentration-dependent influence of MPA on the IMPDH basal activity was observed. At concentrations < or =IC50, MPA increased the IMPDH basal activity. The increase was associated with elevated expression of IMPDH2. Despite increased expression, the basal enzyme activity decreased following exposure to high MPA concentrations. The IMPDH2 expression increased modestly in response to tGuO exposure. However, the IMPDH basal activity decreased when the cells were exposed to a proliferation-blocking tGuO concentration. CONCLUSIONS: These findings demonstrate that IMPDH basal activity is influenced by MPA and tGuO, and suggest that reduced IMPDH basal activity is related to the proliferation-blocking effects of these agents.     

Sclerotherapy: a truly minimally invasive technique

Foam sclerotherapy offers a treatment strategy with great potential. Recently, general and vascular surgery have become less invasive; so too, has the treatment of venous disorders. Sclerosants cause irreversible damage to the vascular endothelium by disrupting cell membranes resulting in sustained vasospasm and denudation of the venous monolayer. Prospective randomized outcome data support the hypothesis that foam sclerotherapy is superior to liquid sclerotherapy. All published reports of varicose vein treatment with foam describe efficacy in terms of immediate and primary venous occlusion of better than 80%. Severe complications of foam sclerotherapy are rare. Recurrent varices are in the 10% to 20% range. Use of foam sclerotherapy in our experience has proven to be effective, essentially pain-free, and durable in the short term. The treatment is quick, efficient, and cheap.     

Risk factors for chronic venous disease: the San Diego Population Study

BACKGROUND: The etiology of chronic venous disease in the lower limbs is unclear, and very limited data are available on potential risk factors from representative population studies. METHODS: Participants in the San Diego Population Study, a free-living adult population randomly selected from age, sex, and ethnic strata, were systematically assessed for risk factors for venous disease. Categorization of normal, moderate, and severe disease was determined hierarchically through clinical examination and ultrasonography imaging by trained vascular technologists, who also performed anthropometric measures. An interviewer administered a questionnaire and an examination assessed potential risk factors for venous disease suggested by previous reports. RESULTS: In multivariable models, moderate venous disease was independently related to age, a family history of venous disease, previous hernia surgery, and normotension in both sexes. In men, current walking, the absence of cardiovascular disease, and not moving after sitting were also predictive. Additional predictors in women were weight, number of births, oophorectomy, flat feet, and not sitting. For severe disease, age, family history of venous disease, waist circumference, and flat feet were predictive in both sexes. In men, occupation as a laborer, cigarette smoking, and normotension were also independently associated with severe venous disease. Additional significant and independent predictors in women were hours standing, history of leg injury, number of births, and cardiovascular disease, but African American ethnicity was protective. Multiple other postulated risk factors for venous disease were not significant in multivariable analysis in this population. CONCLUSIONS: Although some risk factors for venous disease such as age, family history of venous disease, and findings suggestive of ligamentous laxity (hernia surgery, flat feet) are immutable, others can be modified, such as weight, physical activity, and cigarette smoking. Overall, these data provide modest support for the potential of behavioral risk-factor modification to prevent chronic venous disease.     

Development and in vitro validation of anti-mesothelin biobodies that prevent CA125/Mesothelin-dependent cell attachment

Preventing peritoneal implantation of carcinoma cells could prolong ovarian cancer patient remission and survival. Peritoneal cells constitutively express mesothelin, a ligand for CA125 that is expressed by tumor cells. Thus blocking CA125/mesothelin-dependent cell attachment may prevent or delay peritoneal metastatic recurrence. We developed a high-throughput screening system for reagents able to block CA125/mesothelin-dependent cell attachment with a sensitive quantitative readout. Using a novel yeast-expression system to produce secreted, in vivo biotinylated proteins and biobodies (Bbs), we generated anti-mesothelin Bbs. Anti-mesothelin Bbs derived from high affinity yeast-display scFv detected both membrane-bound and soluble mesothelins and inhibited CA125/mesothelin-dependent cell attachment.     

Unexpected, late cardiovascular effects of surgery for peripheral artery disease. Veterans Affairs Cooperative Study 199.

In reviewing late morbidity of a multicenter clinical trial comparing balloon angioplasty (percutaneous transluminal angioplasty) with bypass surgery for lower-extremity ischemia, an unexpectedly high incidence of adverse systemic events in surgical patients was uncovered. The study was prospective and randomized, and included a total of 263 patients, with follow-up from 2 to 6 years. When end points of related deaths, amputations, and intervention failures were summed, surgery was favored over percutaneous transluminal angioplasty at 4 years. Progression of cardiac and renal dysfunction and mortality differed between groups. A total of 42 deaths were in the group who underwent surgery and 27 in those who underwent percutaneous transluminal angioplasty. The percentage difference in death rate between the two groups increased each year to reach 10% at 5 years. A significant difference in renal function was noted in nine patients who underwent surgery and zero who underwent percutaneous transluminal angioplasty. Myocardial infarctions were greater on follow-up of surgical patients. After 6 years, congestive heart failure had occurred in 19 patients who underwent surgery and eight who underwent percutaneous transluminal angioplasty. The trends in this study of patients with only moderately severe peripheral arterial disease suggest an increased rate of deterioration of cardiac and renal function in patients who have arterial operations. In surgical patients, mortality was 13.1% per year, whereas it was 8.4% for patients treated with percutaneous transluminal angioplasty. Future intervention studies should include long-term follow-up of such cardiovascular events.