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J Reinhardt

Publications and source records attributed to J Reinhardt.

At least 19 recordsLinked to original sources
PubMed1996

Three-year experience with a stylet for lead extraction: a multicenter study.

INTRODUCTION: The extraction of chronically implanted and infected pacemaker and defibrillator leads is an important issue. This article describes the experience gathered between 1990 and 1994 by seven European centers regarding a locking stylet that is uniformly applicable for a wide variety of internal pacing coil diameters. This interventional locking stylet for lead extraction has an outer diameter of 0.4 mm (0.016 inches). The stylet consists of a hollow shaft in which an inner traction wire is embedded. At the tip of the inner traction wire an anchoring mechanism, which can be opened by retraction, is applied. Removal attempts were made for 150 leads, 110 in ventricular and 40 in atrial positions. RESULTS: Complete removal was possible in 122 cases (81%). Partial removal was possible in 18 cases (12%). Failure to remove the lead with the extraction stylet was experienced in 10 cases (7%). In seven patients, the leads were removed by cardiothoracic surgery; 3 defective leads were left in place. There were no serious complications associated with the procedure. None of the patients died. CONCLUSION: The experience with this extraction stylet for lead removal has shown good results. Despite a low complication rate thus far, each case for lead removal should be judged on the individual basis of benefit-to-risk ratio.

Aged↗
PubMed1995

Highly sensitive coupled-column high-performance liquid chromatographic method for the separation and quantitation of the diastereomers of leucovorin and 5-methyltetrahydrofolate in serum and urine.

A column-switching chiral HPLC assay was developed that allows the separation and quantitation of the diastereomers of leucovorin (LV, 5-formyltetrahydrofolic acid) and its metabolite 5-methyltetrahydrofolate (METHF) in serum and urine by means of fluorescence detection. The analysis procedure consists of an on-line concentration of the folates in the HPLC system which is followed by the elution and separation of folates on an achiral 3-microns Microbore C18 column in (6R,S)-LV and (6R,S)-METHF. (6R,S)-LV and (6R,S)-METHF are subsequently transferred on-line onto a chiral 7-microns bovine serum albumin column through a Rheodyne valve system and are separated into their diastereometers. Time of analysis is 70 min. Detection limit is 5 ng/ml for each diastereometer. The within-day variation ranges between 3.2 and 15.8% in relation to the measured concentration. Between-day variation is 4.4-12.1% for a concentration of 100 ng/ml for each diastereometer. (6R,S)-LV and (6S)-LV pharmacokinetics were assessed by analyzing serum and urine samples of four-healthy volunteers.

Antineoplastic Agents↗
PubMed1994

Genotoxicity and carcinogenicity in rats and mice of 2-amino-3,6-dihydro-3-methyl-7H-imidazolo[4,5-f]quinolin-7- one: an intestinal bacterial metabolite of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline.

BACKGROUND: Compounds formed on the surface of fried or grilled meat and fish may be associated with increased risk of colon cancer. Normal intestinal bacteria can convert one of these compounds, 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), to the 7-hydroxy metabolite, 2-amino-3,6-dihydro-3-methyl-7H-imidazolo[4,5-f]quinolin-7-o ne (7-OHIQ), a direct-acting mutagen. PURPOSE: We studied the genotoxicity and carcinogenicity of 7-OHIQ to determine if it is responsible for the colon-specific activity of IQ. METHODS: The effects of pure, synthetic 7-OHIQ on DNA were evaluated in the Ames Salmonella typhimurium TA98 test, with and without an induced rat liver S9 fraction, and in the Williams DNA repair test using freshly explanted rat hepatocytes. 7-OHIQ was also subjected to an in vivo bioassay for 21 months by long-term intrarectal infusion in male F344 rats, using IQ and N-nitrosomethylurea (NMU) given intrarectally as positive tumor-producing controls. The standard NIH-07 rodent diet was supplemented with 15% corn oil to maximize any effect of the infused materials on the colon. A parallel bioassay involved intraperitoneal injection of 7-OHIQ in newborn mice, followed by dietary administration from week 11 to week 67. Again, IQ and NMU were used as positive controls. RESULTS: We confirmed that 7-OHIQ is a direct-acting mutagen in the Ames test, with added S9 liver fraction giving higher mutagenicity. 7-OHIQ was negative in the Williams test, whereas IQ was positive. 7-OHIQ did not induce colon cancer in rats, and in the newborn mouse test it produced only a low incidence of liver neoplasms. CONCLUSIONS: 7-OHIQ is not genotoxic, for to be so classified it must be definitely positive in both the Ames and Williams tests; moreover, it is not carcinogenic, in marked contrast to IQ and NMU.

Animals↗
PubMed1994

The role of fat and calcium in the production of foci of aberrant crypts in the colon of rats fed 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine.

The modulation by dietary fat levels of intestine carcinogenesis is well documented. New developments suggest that calcium ions may also play a role. A rapid bioassay, the induction of foci of aberrant crypts in the colon, was used to explore the interaction between dietary fat and calcium. Male F344 rats 6 weeks of age were placed on diets containing 5 or 20% corn oil, and 0.04 or 0.32% calcium ion, as calcium lactate. Each dietary group was fed 400 ppm 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhlP), and negative controls received the diets alone. A positive control group was given 2 mg N-nitrosomethylurea (NMU) intrarectally four times in a 2-week period. All rats were killed after 9 weeks. The intestinal tract was rinsed with Krebs-Ringer buffer. After staining a 6-cm segment of the descending colon and rectum with 0.2% methylene blue, foci of aberrant crypts were evaluated microscopically. With PhlP as a carcinogen, the rats on a high-fat, low-calcium level had more foci of aberrant crypts than animals on a low-fat level. With the higher calcium level, there were fewer foci and aberrant crypts, but the effect of fat was still significant. With NMU and a low-calcium level, the effect of fat level was evident. However, with the higher calcium intake, there were considerably more foci of aberrant crypts than on the low-calcium level, and the effect of the dietary fat level was not obvious.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Identification of alcoholism and depression in a geriatric medicine outpatient clinic.

OBJECTIVE: To examine the utility of brief screening instruments for alcoholism and depression in the frail elderly medical outpatient. DESIGN: Cross-sectional examination. SETTING: Coffey Geriatric Outpatient Clinic, The Mount Sinai School of Medicine, New York City. SUBJECTS: Convenience sample of 84 consenting male and female outpatients over 62 years of age. MEASUREMENTS: The Michigan Alcohol Screening Test (MAST), CAGE questionnaire, and the Geriatric Depression Scale (GDS). RESULTS: Four subjects (5%) scored positive for alcoholism on the MAST, all of whom had been previously identified by the geriatric clinic staff. In contrast, the CAGE only identified 1 (1.4%) alcoholic subject. Thirty-two percent of subjects scored positive for depression on the GDS, yet only one-third of these depressed patients had been previously identified by the geriatric team as depressed. Among the depressed outpatients, 19% were labeled anxious and received anxiolytics from the geriatric medical staff. CONCLUSIONS: Whereas brief alcohol screening instruments to detect alcoholism did not augment the geriatrician's clinical assessment, screening for depression with the GDS may be an important adjunct to the identification of depression in geriatric medical patients.

Aged↗
PubMed1993

Penetration of Sandimmune (cyclosporin A) in rat skin in vitro. Effects of penetration enhancers and solvents.

The effect of various fatty acids or alcohols on the penetration rates and skin concentrations of cyclosporin A (Sandimmune; CyA) was evaluated in an in vitro model using skin of hairless rats. The influence of chain length, number and position of double bonds and branching of the carbon chain of the enhancer were investigated. In addition the penetration dependency of CyA on the concentration of both enhancer and CyA was studied. CyA was quantitated by high-performance liquid chromatography. The penetration rates of CyA through rat skin decreased with increasing number of double bonds of the enhancer and decreasing CyA concentrations in the donor solution, and increased with increasing chain length of the enhancer. Enhancers increase penetration rates by a factor of up to 20-90 in alcoholic vs. maximally 5-fold in oily compositions. Enhancers increase skin concentrations of CyA by a factor of up to 10-25 in alcoholic and about 4-20 in oily compositions.

Animals↗
PubMed1992

A three-year evaluation of the know your body program in inner-city schoolchildren.

The impact of the Know Your Body (KYB) comprehensive school health education program was evaluated in a sample of first through sixth-grade students from New York City, using two analytic strategies: a longitudinal cohort and a "posttest only" cohort. In both cohorts, program impact was examined between condition (i.e., KYB vs. no-treatment comparison group) as well as within condition (i.e., low, moderate, and high student exposure). Students in the longitudinal cohort (n = 1,209) who were exposed to high implementation teachers had significantly (p < .05) lower total plasma cholesterol and systolic blood pressure at 3-year posttest than comparison students. Students in the posttest only cohort (n = 3,066) who had high implementation teachers showed significantly (p < .05) lower total plasma cholesterol, systolic blood pressure, self-reported intake of meat and desserts, as well as higher health knowledge and self-reported intake of "heart healthy" foods and vegetables than comparison students. In both cohorts, program effects for several outcome variables were linearly related to level of student exposure to the curriculum, suggesting a dose-response effect. While several methodologic limitations may have influenced study outcomes, these data nonetheless appear to confirm that the KYB program can have a significant positive impact on the knowledge, behavior, and selected risk factors of students in primary grades and that efforts to disseminate and evaluate school health education programs should include strategies to monitor and enhance teacher implementation.

Blood Pressure↗
PubMed1990

Influenza.

Explore the source record for details and available documents.

Aged↗
PubMed1989

Effect of enzyme inducers on the metabolism of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in the rat.

The effect of enzyme inducers 3-methylcholanthrene (3-MC) and Aroclor 1254 (A-1254) on the metabolic fate of the dietary mutagen and carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in male F344 rats was studied in relation to single dose corn oil and untreated controls. The latter two groups were similar as regards metabolism of IQ. However, the ratio of total metabolites excreted in urine compared with those in feces was higher in A-1254 pretreated rats. In fact, this distinct excretory pattern stemmed from a lower level of IQ-N-sulfamate, and a considerably higher level of 5-OH-IQ sulfate ester, a major metabolite in urine of A-1254-injected rats. Interestingly, 5-OH-IQ glucuronide urinary levels were unaffected by the treatment. Thus, the direct 5-hydroxylation of IQ appears to be considerably increased by 3-MC and more so by A-1254, and under those conditions the resulting 5-OH-IQ is preferentially converted to the sulfate ester, in turn readily excreted in urine.

Animals↗
PubMed1987

Transfer of the tobacco-specific carcinogens N'-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and benzo[a]pyrene into the milk of lactating rats.

The extent to which some of the more prevalent and potent carcinogens in cigarette smoke could be transferred from circulating blood into the milk of lactating rats was determined. One hour after i.v. administration of benzo[a]pyrene (BaP), N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) to the dams, the levels of these carcinogens were determined in both blood and milk specimens. The average amount of radioactivity detected 1 h after administration of 14C-labeled BaP was 0.21% of the administered dose per ml of milk as compared with 0.17% per ml of blood. The amount of NNN in milk ranged from 0.20 to 0.36% of the administered dose per ml which closely paralleled the levels detected in blood. NNK is readily converted in vivo to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). The sum of NNK and NNAL was similar in the blood and milk of treated dams. There was, however, a major difference in the ratio of NNAL/NNK as detected in milk and blood. The ratio of NNAL/NNK in blood ranged from 1.3:1 to 1.9:1 while the ratio in milk ranged from 2.4:1 to 3.3:1. In a comparative study of the levels of NNN in the blood and milk of lactating rats at less than 1.0, 20, 60, 120 and 240 min after administration, it was confirmed that similar concentrations of NNN are present in blood and milk 1 h after administration. These data indicate that these carcinogens, which are present in both cigarette smoke and tobacco, can be transferred into the milk of lactating rats.

Animals↗
PubMed1987

Bowel flora changes in humans receiving cefixime (CL 284,635) or cefaclor.

Twelve healthy young male subjects received either cefixime, a new oral cephalosporin (CL 284,635), or cefaclor (six subjects on each drug) orally for 2 weeks. In the case of cefixime, single daily doses of 400 mg were taken; with cefaclor, the dosage was 250 mg three times daily. Modest changes in the fecal flora were noted in both drug groups, but the changes were of different types. In the case of cefixime, there was more of an impact on the indigenous flora, and in the case of cefaclor, there was more ingrowth of new flora. With cefixime, Enterobacteriaceae were usually decreased (the decrease in Escherichia coli count was statistically significant), as were counts of clostridia and sometimes Bifidobacterium spp.; the Bacteroides fragilis group was eliminated in one subject. Coincident with these decreases, four subjects had increases in counts of group D streptococci of 3 logs or more. There was new appearance of Clostridium difficile in four subjects and of Staphylococcus aureus in one; four new strains of Enterobacteriaceae appeared. With cefaclor, there was no decrease of E. coli counts; two subjects had elimination of Bifidobacterium spp. There was little change in counts of group D streptococci. On the other hand, there were 13 new strains of Enterobacteriaceae, two of S. aureus, and three of C. difficile.

Bacteria↗
PubMed1986

Toxicity studies on clove cigarette smoke and constituents of clove: determination of the LD50 of eugenol by intratracheal instillation in rats and hamsters.

Eugenol, eugenol acetate, beta-caryophyllene, and alpha-humulene are constituents of clove and clove cigarette smoke. The toxicity of these compounds was evaluated by intratracheal instillation in male F-344 rats. Eugenol was most toxic in this assay. The LD50 of eugenol was 11 mg/kg in male F-344 rats and 17 mg/kg in male Syrian golden hamsters. Congestion of the lung with interstitial hemorrhages, acute emphysema, and acute pulmonary edema were among the macroscopic and histologic findings observed in the animals after intratracheal administration of eugenol. Similar effects were not observed with male Syrian golden hamsters exposed to clove cigarette smoke. The estimated daily intake of eugenol for those hamsters exposed to clove cigarette smoke was below 2 mg/kg.

Animals↗