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Biomedical subjects

R Frank

Publications and source records attributed to R Frank.

At least 541 records · Page 30Linked to original sources
PubMed1979

Simple method to detect virus-specific IgM antibodies in patients' serum samples after immunosorption of immunoglobulins G and A.

By absorption with protein A and specific immunosorption using insolubilized adsorbentia (CPG), a method was developed for rapid elimination of IgG and IgA from patients' serum samples. This test technique was examined in the diagnosis of rubella infections, i.e., rubella-specific IgM antibodies. The procedure has proven to be as reliable as determinations carried out with IgM fractions separated on a sucroe density gradient.

Antibodies, Viral↗
PubMed1979

The phosphoenolpyruvate-dependent phosphotransferase system of Staphylococcus aureus. Complete tyrosine assignments in the 1H nuclear-magnetic-resonance spectrum of the phosphocarrier protein HPr.

Upon nitration of the phosphocarrier protein HPr three nitrated derivatives of the protein were isolated: mononitrated HPr, dinitrated HPr and trinitrated HPr. Tryptic digestion of the derivatives leads to nitrotyrosine-containing peptides which were isolated and characterized by amino acid analysis. This resulted in the determination of the positions of the nitrated tyrosyl residues in the amino acid sequence. In mononitrated HPr only Tyr-56 was modified, in dinitrated HPr both Tyr-56 and Tyr-37 had reacted with the nitrating agent; modification of all three tyrosyl residues in trinitrated HPr required more drastic reaction conditions. The nuclear magnetic resonance spectra of the three derivatives allowed the assignments of the tyrosine resonances as follows: Tyr-A and Tyr-B with pK values of 10.5 and 11.5 were designated Tyr-56 and Tyr-37 whereas Tyr-C, whose protons are not titratable before denaturation of the protein, was assigned to Tyr-6 in the amino acid sequence. The nitration studies, together with the titration behaviour of the three tyrosines, indicate the topology of the tyrosyl residues to be as follows: Tyr-56 is located at the surface, Tyr-37 is slightly buried, Tyr-6 is deeply buried. The nitrotyrosyl derivatives retain their biological activity.

Amino Acids↗
PubMed1979

Organochlorine insecticides and PCB in the sediments of Lake Huron (1969) and Georgian Bay and North Channel (1973).

Surficial and core sediments were collected from the main body of Lake Huron in 1969 and Georgian Bay and North Channel in 1973. These were analysed for organochlorine insecticides and PCB. Residues of organochlorines were higher in the twelve depositional basins in Lake Huron and Georgian Bay than in sediment in the non-depositional zones. PCB was present at similar concentrations to sigma DDT; with mean levels of 13 and 10 ng/g for PCB and sigma DDT in the main body of Lake Huron and 11 and 5 ng/g for PCB and sibma DDT in Georgian Bay. Residues of PCB varied from 9--33 ng/g in the 12 basins. With respect to sigma DDT, both parent DDT and its two metabolites were present in sediment at a mean residue of 7.8 ng/g for the whole lake. The main lake had residues of 10.2 ng/g while Georgian Bay had 5.8 ng/g and North Channel 4.1 ng/g in keeping with use pattenrs since 1943. HEOD was present in only 5.7% of sediment samples from main Lake Huron, 30% from Georgian Bay and 15% from North Channel. The highest residues 1.7 ng/g occurred in the North Channel. No chlordane was detected, however, heptachlor epoxide was identified in 8.5% of sediments collected in Lake Huron, 23% from Georgian Bay and 14% in North Channel. Endosulfan appeared in 4% of samples from both Georgian Bay and North Channel.

Canada↗
PubMed1979

DNA chain length markers and the influence of base composition on electrophoretic mobility of oligodeoxyribonucleotides in polyacrylamide-gels.

The specific influence of the four nucleobases on electrophoretic mobility of oligodeoxyribonucleotides in polyacrylamide-gels under denaturing and nondenaturing conditions has been investigated using homooligomers from the four deoxyribonucleotides as chain length standards. Homooligomers of same chain lengths exhibit remarkable differences in mobility. Specific retardation of any other oligonucleotide investigated was found to be mainly dependent on base composition but not on sequence. A simple procedure is presented for calculating mobilities relative to the standards on denaturing gels. This allows a reliable identification of oligonucleotides on acrylamide-gels by exact chain length determination with respect to base composition and furthermore a detailed interpretation of complex reaction mixtures. The homooligomers also show the same differences in mobility on nondenaturing gels. The significance of this effect for strand separation is discussed.

Base Sequence↗
PubMed1979

Functional anatomy of the cerebral cortex by computed tomography.

The authors describe the morphological characteristics that allow recognition of the individual computed tomography slice and determine its sequence in the series. In addition, each slices is "assembled" by defining the different cortical gyri, sulci, and cortical functional areas (based on Brodmann's maps). This work lays the foundation for correlative studies of location of lesions and the clinical picture.

Brain↗
PubMed1979

A system for rapid measurement of lung function in small animals.

A semiautomated system has been developed to facilitate the rapid measurement of a variety of pulmonary functional parameters in small animals. They include lung volumes, mechanics, flow-volume curves, nitrogen washout curves, and diffusing capacity. The animals are anesthetized, intubated, and ventilated mechanically. The construction of the system is described in detail and the results obtained on rats are compared with those published by other investigators.

Animals↗
PubMed1979

A method for continuous measurement of ammonia in respiratory airways.

A method has been developed that can continuously measure respiratory NH3 with a detection limit of 30 parts per billion by volume (ppbv) at an averaging time of 1 s. The method is based on the chemiluminescent detection of NO, which is produced by oxidizing NH3 at 850 degrees C. A polyethylene sampling probe, incorporating a heated capillary tip bathed in dry, NH3-free diluent air, minimizes NH3 losses due to absorption in breath condensate. In one subject, flow and tidal volume were monitored during quiet mouth breathing while NH3 and CO2 were sampled at the lips. In 10 subjects, NH3, and CO2 were sampled at the lips during quiet mouth breathing ranged from 280 to 1,280 ppbv (mean plus or minus SE, 540 PLUS OR MINUS 85 PPBV).

Ammonia↗
PubMed1979

[Permanent intra-hisian atrioventricular block induced during right intraventricular exploration].

A 47 year old patient underwent endocavitary electrophysiological investigation for recurrent syncopal episodes occuring three years after an inaugural enterior myocardial infarction. Syncopal ventricular tachycardia was induced during the investigation when the bipolar catheter was in contact with the Bundle of His and several external electric shocks were required for its reduction. During cardioversion a complete intra-hisian atrio venticular block was observed and remained permanently although the values of the conduction intervals had previously been normal. This complication of defibrillation is thought to be the result of an induction phenomenon.

Bundle of His↗
PubMed1979

[Fiessinger-Leroy-Reiter syndrome with non-obstructive cardiomyopathy treated with methotrexate].

The case of a 50 year old male with the Fiessinger-Leroy-Reiter syndrome, ankylosing spondylitis and generalised pustular psoriasis is reported. This condition wax complicated by non-obstructive cardiomyopathy, congestive cardiac failure and first-degree atrioventricular block, the site of which was localised by electrophysiological studies (nodal block with an infrahisian conduction defect). After failure of several therapeutic regimes, a spectacular improvement was obtained with Methotrexate associated with a diuretic; the signs of heart failure regressed and the cardiomyopathy stablised. A parallel improvement was seen in the skin, cardiac and articular lesions and has been maintained with an 18 months follow-up. Left ventricular performance was studied by echocardiography. The mechanism of the beneficial effect of Methotrexate is unclear; this therapeutic trial is to be extended to include other cases of primary cardiomyopathy without obstruction.

Arthritis, Reactive↗
PubMed1979

The surgical management of ventricular tachycardia.

A better understanding of the mechanisms of chronic ventricular arrhythmias has led to the development of new surgical techniques for their management with promising results. Simple ventriculotomy is particularly useful in idiopathic ventricular tachycardia (19 cases). Ventricular tachycardia complicating myocardial infarction may be a special indication for an encircling subendocardial ventriculotomy (12 cases).

Chronic Disease↗
PubMed1979

[Computers in intensive care units (author's transl)].

The increasing amount of physiological data which is required to be stored and displayed has created a need for computers in Intensive Care Units. Small computerised units are now available with three main advantages: 1. A memory allowing the display of parameters value and trend curves. 2. A "decision table" allowing more sophisticated diagnosis. 3. The use of new programmes without having to change the unit. These systems are reliable, providing the quality of the input signal is adequate.

Arrhythmias, Cardiac↗
PubMed1979

Herbicide contamination and decontamination of well waters in Ontario, Canada, 1969-78.

OVER THE 10-YEAR period 1969-78, the waters of 237 wells were analyzed because of contamination from herbicide spillage in or near the well, complaints of impaired water flavor, or injury to seedling plants moistened with the well water. Herbicides were identified in 159 wells: 98 had a single herbicide, 46 had two, 12 had three, one had four, and another had five separate herbicides contributing to the contamination. Wells were grouped according to the mode of entry of the contaminant. Entry occurred most commonly as an aerial spray fdrift or in runoff. Serious contaminations were caused by spillage of herbicide concentrates and spray solutions in or around the well. Twenty-four of the contaminated wells were further investigated to determine the persistence of the contaminant and how to remove it. Some wells were decontaminated adequately to allow reuse within nine weeks, others required three years, and yet others had to be abandoned. Particularly persistent contaminants were amitrole, dinoseb, and picloram.

Herbicides↗