Ureteral stricture formation after removal of impacted calculi

PURPOSE: We retrospectively evaluated the records of 21 patients a mean of 46.1 years old with ureteral stones that had been impacted for greater than 2 months to determine predisposing factors for stricture formation. MATERIALS AND METHODS: Between January 1993 and September 1996, 21 patients were referred for ureteral stones that had remained unchanged in location for at least 2 months. In 11 patients previous attempts at stone removal had failed. Each patient underwent successful stone extraction by retrograde or percutaneous antegrade ureteroscopy, or laparoscopic or open ureterolithotomy. Outcome was determined by reviewing the clinical records and radiographic studies, including excretory urography and nephrostography. RESULTS: Average duration of stone impaction before definitive treatment was 8.8 months (range 2 to 48) and mean stone size was 10.3 mm. (range 1 to 30). All stones were calcium based. There were 3 proximal, 8 mid and 10 distal ureteral calculi. At a mean followup of 7 months ureteral strictures developed in 5 patients (24%) at the previous stone site. Mean duration of stone impaction was 11 months (range 5 to 17) in patients with stricture versus 8.2 months (range 2 to 48) in those with no stricture. Four of the 5 strictures occurred in patients who had had iatrogenic ureteral perforation during previous unsuccessful attempts at stone removal. CONCLUSIONS: Ureteral stone impaction more than 2 months in duration is associated with a 24% incidence of stricture formation. Ureteral perforation at the site of the stone was identified as the primary risk factor for stricture formation in these cases.     

Vancomycin penetration into biofilm covering infected prostheses and effect on bacteria

To evaluate the adequacy of penetration of antibiotics into biofilm, a novel in vitro model for prosthesis-related infection was developed. Sterile stainless steel orthopedic nuts were incubated with slime-producing Staphylococcus epidermidis. Biofilm-covered nuts were exposed to varying concentrations of vancomycin; then biofilms were harvested. Vancomycin levels in biofilm, as measured by fluorescent polarization immunoassay, far exceeded the MIC and MBC of vancomycin for the organism. Bacterial growth in biofilm was inversely related to vancomycin concentration in biofilm, but even extremely high drug concentrations did not eradicate bacteria embedded in biofilm. The MICs and MBCs for bacteria recovered from biofilm did not differ from those for incubating organisms. Thus, failure of glycopeptide antibiotics to cure prosthesis-related infection is not due to poor penetration of drugs into biofilm but likely due to diminished antimicrobial effect on bacteria in the biofilm environment.     

Modification of organosulfur compounds and water-soluble coal-derived material by anaerobic microorganisms

The transformation of organosulfur compounds by anaerobic microorganisms may be of interest for coal desulfurization. An anaerobic microbial community indigenous to cyanobacterial mats of a Yellowstone National Park hot spring was assessed for the ability to evolve volatile sulfur compounds from benzyl methyl sulfide, benzyl methyl disulfide, methionine and water-soluble lignite-derived material. The addition of methionine or benzyl methyl disulfide stimulated the production of methanethiol by slurries made with cyanobacterial mat material. Transformation of methionine appeared to be the direct result of microbial activity. However, the evolution of methanethiol from benzyl methyl disulfide appeared to be the indirect result of microbial activity, that is, the cleavage of the disulfide linkage may have resulted from the reduction by microbially produced hydrogen sulfide. Results indicated a transient interaction of hydrogen sulfide and methanethiol with the coal material. In separate studies, sulfate-reducing bacteria were examined for the modification of water-soluble lignite-derived material. As expected, the sulfur content of the soluble material increased under conditions of sulfate respiration. However, when grown fermentatively without the production of sulfide, two of the nine cultures examined reduced the sulfur content of the soluble material. Most of the cells in all the cultures immediately lysed upon the addition of the soluble material. By 2 weeks, cell densities were greater in cultures amended with soluble coal material than in control cultures.     

A comparative study of in vivo mutation assays: analysis of hprt, lacI, cII/cI and as mutational targets for N-nitroso-N-methylurea and benzo[a]pyrene in Big Blue mice

We have compared the response of the native hprt gene and the lacI, cII, and cI transgenes in Big Blue B6C3F1 mice following treatment with either N-nitroso-N-methylurea (MNU) or benzo[a]pyrene (BaP). Three weeks after mutagen treatment splenic T cells were isolated from the animals, and samples were either cultured to measure mutation at the native hprt locus or used to extract genomic DNA for transgene mutation analysis. Phage rescued from extracted DNA were plated in the presence of 5-bromo-4-chloro-3-indolyl-beta-d-galactopyranoside (X-gal) to score lacI mutations, or plated on a hflAB lawn to score cII and cI mutants. With MNU hprt mutant frequency increased in a dose-related, sublinear manner up to 78-fold above background at the highest dose tested (20 mg/kg). In comparison, the lacI transgene yielded only a 3.1-fold increase at this dose, and the cII and cI transgenes did not show any increase. With 150 mg/kg BaP a 5.8- and 8.7-fold increase in mutant frequency was observed at hprt and lacI, respectively, while only a 1.3-fold increase was observed at cII. DNA sequencing revealed an increase in GC-->TA transversions among the cII mutants, suggesting that the increase was related to BaP exposure. No significant increase in cI mutant frequency was observed. Therefore, the order of mutation assay sensitivity was hprt>lacI>cII/cI with MNU, and hprt approximately lacI> cII/cI with BaP. While the hflAB selection system offers significant advantages with respect to cost and effort when compared to the lacI assay, additional evaluation of its sensitivity is warranted.     

Long-term results of femorotibial bypass with vein or polytetrafluoroethylene

OBJECTIVE: The purpose of this study was to determine predictors of posttraumatic stress disorder (PTSD) in health care workers exposed to a disaster, in order to facilitate early case identification and prevention of subsequent morbidity. METHOD: Following an air disaster, 355 military medical health care workers were studied over an 18-month follow-up period. Measures included assessment of peritraumatic reactions associated with the disaster, the frequency of other stressful events after the disaster, and standard PTSD rating scales at 6, 12, and 18 months. RESULTS: Multivariate logistic regression of data on health care workers who cared for victims of the air disaster showed that PTSD was more likely to develop in those who had not completed college, those who had worked with burn victims, those who had experienced more stressful life events in a period of approximately 6 months following the disaster, and those who experienced emotional numbness immediately after the disaster. CONCLUSIONS: Results suggest that lower levels of education, exposure to grotesque burn injuries, stressful life events following exposure, and feelings of numbness following exposure are useful predictors of subsequent development of PTSD.     

The HMG-CoA reductase inhibitor atorvastatin increases the fractional clearance rate of postprandial triglyceride-rich lipoproteins in miniature pigs

We have previously shown in vivo that the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor atorvastatin decreases hepatic apolipoprotein B (apoB) secretion into plasma. To test the hypothesis that atorvastatin modulates exogenous triglyceride-rich lipoprotein (TRL) metabolism in vivo, an oral fat load (2 g fat/kg body wt) containing retinol (50 000 IU) was given to 6 control miniature pigs and to 6 animals after 28 days of treatment with atorvastatin 3 mg. kg-1. d-1. A multicompartmental model was developed by use of SAAM II and kinetic analysis performed on the plasma retinyl palmitate (RP) data. Peak TRL (d<1.006 g/mL; Sf>20) triglyceride concentrations were decreased 29% by atorvastatin, and the time to achieve this peak was delayed (5.2 versus 2.3 hours; P<0.01). The TRL triglyceride 0- to 12-hour area under the curve was decreased by 24%. In contrast, atorvastatin treatment had no effect on peak TRL RP concentrations, time to peak, or its rate of appearance into plasma; however, the TRL RP 0- to 12-hour area under the curve was decreased by 20%. Analysis of the RP kinetic parameters revealed that the TRL fractional clearance rate was increased significantly, 1.4-fold (3.093 versus 2.276 pools/h; P=0.012), with atorvastatin treatment. The percent conversion of TRL RP from the rapid-turnover to the slow-turnover compartment was decreased by 47% with atorvastatin treatment. The TRL RP fractional clearance rate was negatively correlated with very low density lipoprotein apoB production rate measured in the fasting state (r=-0.49). Thus, although atorvastatin had no effect on intestinal TRL assembly and secretion, plasma TRL clearance was significantly increased, an effect that may relate to a decreased competition for removal processes by hepatic very low density lipoprotein.     

An epidemic of Malassezia pachydermatis in an intensive care nursery associated with colonization of health care workers' pet dogs

BACKGROUND: Malassezia species are lipophilic yeasts that are emerging as nosocomial pathogens, particularly in low-birth-weight neonates who receive lipid emulsions. When a cluster of patients with Malassezia pachydermatis infection was identified in an intensive care nursery, we initiated an investigation. METHODS: A case patient was defined as any infant in the intensive care nursery who had a positive culture for M. pachydermatis between October 17, 1993, and January 18, 1995. We conducted a cohort study to identify risk factors for colonization and infection with M. pachydermatis. We collected cultures from the infants and the health care workers and from the health care workers' pets, since this organism has been associated with otitis externa in dogs. RESULTS: Fifteen infants met the case definition: eight with bloodstream infections, two with urinary tract infections, one with meningitis, and four with asymptomatic colonization. The case patients were significantly more likely than the other infants to weigh 1300 g or less (15 of 65 vs. 0 of 419, P<0.001). In a multivariate analysis of infants weighing 1300 g or less, the independent risk factors for colonization or infection with M. pachydermatis were a greater severity of concomitant illness (odds ratio, 19.7; P=0.001), arterial catheterization for nine or more days (odds ratio, 29.5; P=0.027), and exposure to Nurse A (odds ratio, 74.7; P=0.004). In a point-prevalence survey, 9 additional infants, 1 health care worker, and 12 of the health care workers' pet dogs had positive cultures for M. pachydermatis. The isolates from all 15 case patients, the 9 additional colonized infants, 1 health care worker, and 3 of the 12 dogs had identical patterns of restriction-fragment-length polymorphisms. CONCLUSIONS: In this outbreak, it is likely that M. pachydermatis was introduced into the intensive care nursery on health care workers' hands after being colonized from pet dogs at home. The organism persisted in the nursery through patient-to-patient transmission.     

Interleukin-4 enhances the survival of severe combined immunodeficient mice engrafted with human B-cell precursor leukemia

Human interleukin-4 (huIL-4) has been shown to inhibit the growth in vitro of cells from patients with acute lymphoblastic leukemia (ALL). With the aim of determining whether this cytokine might be useful in the treatment of patients with ALL, the effects of huIL-4 on human B-cell precursor ALL engrafted in severe combined immunodeficient (SCID) mice were examined. The inhibition of [3H] thymidine uptake of primary ALL cells by huIL-4 was maintained following engraftment and passage of leukemia in SCID mice. Five of seven xenograft leukemias showed significant inhibition in vitro by huIL-4 at concentrations as low as 0.5 ng/mL; furthermore, huIL-4 counteracted the proliferative effects of IL-7. When used to treat two human leukemias engrafted in SCID mice, huIL-4 200 microgram/kg/d, as a continuous 14-day subcutaneous infusion, suppressed the appearance of circulating lymphoblasts and extended survival of mice by 39% and 108%, respectively, the first demonstration of IL-4 activity against human leukemia in vivo. The mean steady-state huIL-4 level in mouse plasma during the infusion was 1.46 ng/mL (SEM +/- 0.14 ng/mL), which was similar to concentrations found to be effective in vitro. ALL cells obtained from mice relapsing after huIL-4 treatment continued to show inhibition by the cytokine in vitro. These data suggest that IL-4 may be useful in the treatment of patients with ALL.     

Dynamic Systems and the Therapeutic Action of the Analyst: II. Clinical Application and Illustrations.

The author presents a dynamic systems approach to psychoanalytic practice. It depicts psychoanalysis as an activity-dependent, experientially based treatment in which the analyst's behavior toward a patient effects change in how the patient organizes and interprets self-experience and relates to others. The neurobiological and relational components of this approach are reviewed, and their implications for psychoanalytic process and technique are described. Several clinical vignettes illustrate the technical application, dynamic process, and therapeutic action of a dynamic systems perspective on psychoanalytic treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Results of microgravity investigation on adsorption and interfacial rheology of soluble surfactants from the experiment FAST onboard STS-107

Microgravity offers ideal diffusive conditions for the investigation of the dynamic processes involving surfactant adsorption. Here a summary of the results obtained during the FAST (Facility for Adsorption and Surface Tension studies) experiments on board the NASA Shuttle STS-107 is given. The measured data pertinent to interfacial rheology — i.e., the response of dynamic interfacial/surface tension to imposed perturbation of the interfacial area — for water-hexane and water-air interfaces, in the presence of different non-ionic surfactants are reported and utilised to test available models and to check fundamental aspects of the modelling of dilational rheology.