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Biomedical subjects

R Frank

Publications and source records attributed to R Frank.

At least 667 records · Page 37Linked to original sources
PubMedDate not supplied

Organochlorine and organophosphorus residues in the fat of domestic farm animal species, Ontario, Canada 1986-1988.

During the period 1986-1988 a total of 602 samples of animal products were analysed for organochlorine and organophosphorus pesticides and industrial organic pollutants. Samples of abdominal fat were collected from avian, bovine, caprine, lupine, ovine and porcine species together with hen eggs. The following six compounds were identified in animal tissues: DDE, dieldrin, lindane, PCB, pentachlorophenol and tetrachlorophenol. Pentachlorophenol was the most frequently found contaminant, being identified in 35% of samples, and DDE was the second in 21%. All other contaminants were present in less than 10% of samples. The residues of all six compounds detected were added to give a combined residue. Forty-three per cent of samples had non-detectable residues. A further 31% had combined residues adding to less than 0.01 mg/kg. The highest combined residues ranged between 0.1 and 1.0 mg/kg and were present in 2.8% of samples. One egg sample had a residue of 0.16 mg/kg that exceeded the 0.1 mg/kg maximum residue limit for pentachlorophenol. Residues of chlordane and its metabolites, heptachlor and its epoxide, endosulphan and its sulphate metabolite, dicofol, HCB and mirex were below their detection limits in all samples and no residues of the organophosphorus insecticide listed as applied to livestock were found in meat, fat or egg tissues.

Abdomen↗
PubMedDate not supplied

Residues of insecticides, and fungicides in fruit produced in Ontario, Canada, 1986-1988.

Between 1986 and 1988, 306 composite samples of fruit representing eight commodities were collected from farm deliveries to the marketplace in Ontario, Canada. All samples were analysed for insecticides and fungicides. The analysis procedure included tests for organochlorine, organophosphorus, synthetic pyrethroid and methylcarbamate insecticides and dithiocarbamate, dicarboximide and organochlorine fungicides. The commodities tested included apples, blueberries, cherries, grapes, peaches, pears, raspberries and strawberries. In 14% of all fruit samples, pesticide residues were below the detection limits, which ranged between 0.005 and 0.02 mg/kg. A further 14% had total combined pesticide residues below 0.1 mg/kg. Total combined fungicide and insecticide residues ranged from 0.1 to 11 mg/kg in 72% of samples. Six different pesticides were in violation of maximum residue limits (MRL) on 11 (3.6%) of fruit samples. Captan exceeded the 5 mg/kg MRL in five samples and EBDC exceeded the 7 mg/kg MRL in two. Other violations included single fruit samples with dicofol, endosulphan, phosalone and iprodione above the MRL. Raw grapes harvested for wine contained residues of 10 pesticides and the number changed little following the crushing of the grapes; however, fermentation into wine significantly reduced residues. Six insecticides and four fungicides were present on the raw grapes and 4/105 were above the MRL. Following crushing, four insecticides and five fungicides were identified and 4/40 were above the MRL. In wine only three insecticides were identified and all were well below the MRL. Carbaryl appeared to be the most persistent, declining very little between raw grapes and wine.

Food Contamination↗
PubMedDate not supplied

Racial/ethnic disparities in infant mortality: the role of behavioral factors.

Using the National Maternal and Infant Health Survey 1988 (NMIHS), a nationally representative sample of mothers, we investigate the role of behavioral factors in explaining racial/ethnic disparities in infant mortality. In particular, we focus on the following variables: weight gain during pregnancy, prenatal care utilization, exercise, vitamin use, and substance use during pregnancy. These analyses are conducted by modeling both time of death (neonatal vs. postneonatal) and cause of death (infections, perinatal complications, delivery complications, congenital malformations, SIDS, other causes) outcomes. Our results suggest that behavioral factors are partially responsible for observed race/ethnic differentials in infant mortality, but are not as important as sociostructural determinants such as SES.

Adolescent↗
PubMedDate not supplied

An efficiently transcribed human tRNA(Val) gene variant produces a stable pre-tRNA: repair of the processing defect by in vitro mutations.

A tRNA(CACVal) gene variant, pHtV4, was cloned from human placenta genomic DNA. This gene differs from a closely related, functional tRNA(CACVal) gene by four base exchanges: T residues in place of C25, C62, and C66 create G:U pairs, and an A instead of G65 creates an A:C mismatch in the corresponding RNA transcript. The tRNA(Val) gene variant in pHtV4 is efficiently transcribed in HeLa cell nuclear extracts; however, the resulting pre-tRNA is processing-deficient, i.e., neither its 5'- nor its 3'-flanking sequences are removed to generate mature tRNA. Reversion of all four point mutations in pHtV4 by oligonucleotide-directed mutagenesis yielded a functional tRNA(CACVal) gene within the flanks of pHtV4, the pre-tRNA of which was processed to mature tRNA. Construction of a chimeric tRNA(Val) gene and site-directed mutagenesis of the tRNA(Val) gene in pHtV4, respectively, followed by transcription and processing studies showed that each of the four mutations contributes to the processing defect of the pHtV4-derived pre-tRNA. Moreover, this revealed that G:U pairs, which are common in all tRNAs, can impair pre-tRNA processing and therefore do not occur in certain positions in eukaryotic tRNAs.

Base Sequence↗
PubMedDate not supplied

Development of an index of maternal transport.

The authors used a decision-analytic approach to develop a Maternal Transport Index (MTI) from ACOG guidelines for maternal transport. Data were obtained from three questionnaires administered to five perinatologists, practicing in facilities with various casemixes. Each questionnaire was based on a given level of hospital and contained scenarios describing indications for maternal transport. The MTIs, ratios of the logs of the proportions with given outcomes in Level III hospitals relative to Level I (or II) hospitals, ranged from 1.0 to 26.3 for newborn outcomes. They were greater for Level I hospitals (than Level II) and when newborn outcomes included severe disability as well as death. Within gestational age categories, the MTI was generally greatest for active preterm labor and, within complication categories, for 24-26 or 27-31 weeks' gestation. It was large for maternal outcomes only for two rare acute medical conditions. The MTI has potential use in setting priorities for maternal transport.

Adult↗
PubMedDate not supplied

[Endocardial fulguration for the treatment of ventricular tachycardia. Experience with 69 cases].

Between 1983 and 1989, 69 patients underwent endocardial fulguration for drug-resistant VT which had several relapses per month, or were incessant. The etiologies were an old myocardial infarction, (25 cases) arrhythmogenic right ventricular dysplasia, (19 cases) dilated cardiomyocathy, (9 cases) left fascicular tachycardia, (9 cases) 5 right septal idiopathic tachycardia, and 2 congenital heart disease. The ejection fraction ranged between 12 and 30% in 25 cases. VT originated in 32 patients in the right ventricle, 31 in the left, and 6 had fulguration in both ventricles. 41 patients had 1 session, 22 needed 2, 4 had three sessions and 2 had 4. Five patients died during the procedure, four of low output, and three of them before the shocks. One died of tamponade. Two others had tamponade and were successfully drained. Four patients died during the first 3 months of preexisting heart failure without VT relapse. The remaining patients have a mean follow-up of 32 months, ranging from 3 to 72 months. 32 patients are off drug and had no relapse. 23 had early relapses, and are controlled by previously ineffective drugs. However 3 of these had a late sudden death (4, 14 and 22 months). 9 are treated with a combination of drug not tested before. The success rate ranges from 60% in septal VT to 74% in ARVD, 86% in MI and 100% in idiopathic left fascicular VT. The success rate increases with the number of sessiones. Fulguration alone, or combined with pharmacological agents can be considered as an effective therapy for VT, despite that it is neither simple, nor harmless.

Adolescent↗
PubMedDate not supplied

[Medical treatment of sustained ventricular tachycardia. Retrospective study of 85 patients].

In this retrospective study the antiarrhythmic of 85 patients suffering from sustained and recurrent attacks of ventricular tachycardia is analysed. Among these patients, 48 had ischaemic heart disease, 18 had right ventricular arrhythmogenic dysplasia, 9 had dilated cardiomyopathy and 2 had complex heart disease; in 8 patients the tachycardia was idiopathic. Two hundred and seventy-two antiarrhythmic treatments administered orally alone or in combination were studied. Their effectiveness was evaluated on the clinical course of the disease, on the résults of Holter recordings and, in some cases, on electrophysiological exploration. The mean follow-up period was 50 months. Each patient received 3.2 antiarrhythmic treatments on average. The effectiveness and side-effects of these treatments are analysed retrospectively, but the relative effectiveness of a treatment compared to another cannot be extrapolated to a new patient. Prescription in this field is purely empirical. The recent amiodarone-flecainide combination has been the most frequently used antiarrhythmic treatment in recent years. It was given to 33 patients in this series and proved effective in 21 patients followed up for 22 months.

Adolescent↗
PubMedDate not supplied

[Ventricular dysplasia. Nosology and sudden death].

The arrhythmia generating dysplasia of the right ventricle is a congenital anomaly suggesting a hereditary substratum. It usually manifests itself as follows: a young patient, with recurrent episodes of ventricular tachycardiac. There is no "pathognomonic sign" of dysplasia. The latter may only be determined by anatomical examination of the heart, macroscopically as well as microscopically. The most difficult differential diagnosis concerns minor or localized forms of dilated idiopathic myocardiopathy or sequelae of myocarditis with ventricular tachycardia originating in the right ventricle. It seems, currently, more appropriate to talk about "arrhythmia generating syndrome of the right ventricle" rather than arrhythmia generating dysplasia of the right ventricle, in these particular cases. The arrhythmia generating syndrome of the right ventricle could cause a sudden death in these young patients, especially during a violent physical exercise or practise of sports. The current nosological classification is based on an experience acquired by comparing a few isolated cases. The search for late potentials by summation-mean measurements and nuclear magnetic resonance could provide a new diagnostic approach.

Death, Sudden↗
PubMedDate not supplied

Residues of insecticides, fungicides, and herbicides on Ontario-grown vegetables, 1980-1985.

Between 1980 and 1985, 354 composite vegetable samples representing 9 vegetable commodities were collected from farm deliveries to the market place in Ontario, Canada. All samples were analyzed for insecticides, 275 for fungicides, and 135 for herbicides. The analyses included organochlorine, organophosphorus, synthetic pyrethroid, and N-methylcarbamate insecticides; dithiocarbamate, acylalanine, phthalimide, dicarboximide, and other fungicides; and, chlorophenoxy acid, chlorobenzoic acid, bipyridilium, phenylurea, carbamate, and other herbicides. The commodities tested included asparagus, beans, carrots, cauliflower, cucumbers, onions, potatoes, sweet corn, and tomatoes. In most samples, pesticide residues were below the detection limits (i.e., 0.005 to 0.1 mg/kg), and most of the positive findings were a fraction (i.e., less than 1 to 20%) of the maximum residue limit (MRL) permitted for each commodity under the Canadian Food and Drugs Act and Regulations. A small number of samples had residues that exceeded the MRL, and these involved aldicarb and linuron on potatoes and chlorobromuron on carrots.

Fungicides, Industrial↗
PubMedDate not supplied

[Enzyme activity of creatine kinase and its MB isoenzyme in endocardial countershock].

Enzymatic activity of total serum CPK and of MB iso-enzyme was studied to assess changes in the myocardium caused by cardioversion. Assay of enzymes was performed prior to cardioversion and every two hours during the first 24 hours after it was administered. 79 instances of cardioversion were reported in a series of 56 patients, including 14 females (mean age 45 years). Cardioversion was employed in the treatment of 23 patients with supra-ventricular tachycardia, and in 56 cases to treat chronic ventricular tachycardia including 23 of ventricular tachycardia arising as a complication of myocardial infarction, 17 cases of arrhythmia-inducing disorders of the right ventricle, 8 cases of primary cardiomyopathy, 7 of idiopathic ventricular tachycardia and 1 of a congenital disorder. The energy of the electric shock administered was 620 +/- 522 joules during the 3 shocks per session, on the average, delivered by an Odam capacitor discharge using a distal electrode connected to the positive pole of an endocardial electrode catheter. A maximum level of total serum CPK equal to 333 +/- 396 U/l was observed 6 +/- 3 hours after cardioversion. The highest level of isoenzymes MB recorded was 30 +/- 24 U/l 4 +/- 2 hours after cardioversion. Compared to electric shock administered to treat ventricular tachycardia, an electric current applied to the His bundle produced the least MB isoenzyme activity (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗