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Biomedical subjects

B Levy

Publications and source records attributed to B Levy.

At least 181 records · Page 10Linked to original sources
PubMed1977

[A system of computer pre-treatment of electrocardiographic data].

A system of analogue pretreatment aimed at analysis of the arrhythmias in real time is presented. It is based on the separate detection of the P wave and the QRS complex, and on the use of a bipolar electrically conducting catheter introduced into the auricle of the right atrium. Such an arrangement is relatively insensitive to adventitous activity, both in the high and low frequency range, and provides on four separate channels impulses representing the P wave, the QRS complex, wide QRS complexes and premature QRS waves. In all cases, the atrial channel transmits all synchronised signals originating from atrial activity without any loss of information. This apparatus has been tried out with various arrhythmias and, if integrated, into a system of automatic detection, it should bring about a considerable saving in time and memory storage space.

Cardiac Complexes, Premature↗
PubMed1976

Fidelity of chromatin transcription in vitro.

Chromatin and DNA from Schneider's Drosophila melanogaster cell line 2 were transcribed in vitro with Escherichia coli RNA polymerase. Using mercurated UTP as precursor, the newly synthesized RNA could be separated from DNA and endogenous RNA by affinity chromatography on sulfhydryl-Sepharose 6B. Characterization of the transcription products with complementary DNA (cDNA) made from polyadenylated nuclear RNA and with fractionated cDNA probe demonstrated a fair quantitative fidelity in the in vitro transcript from chromatin which was not evident when DNA was transcribed. However, as shown by hybridization to total nuclear RNA, E. coli RNA polymerase transcribed both DNA strands from chromatin in vitro. We conclude that E. coli polymerase is able to distinguish sections of chromatin at which rapid synthesis of RNA occurs in the cell.

Cell Line↗
PubMed1976

Relationship between nuclear and cytoplasmic RNA in Drosophilia cells.

Polyadenylated RNA was isolated from nuclei of cultured Drosophila cells, Schneider's line 2, and used as a template to synthesize a complementary DNA probe. Hybridization experiments were performed to study the relationship between nuclear and cytoplasmic RNA. About two-thirds of the nuclear polyadenylated RNA sequences exist in the cytoplasm. Experiments with fractionated cDNA probes demonstrated that RNA sequences that are frequent in the nucleus are also abundant in the cytoplasm. These findings are consistent with a precursor-product relationship in which some polyadenylated molecules in the nucleus are destined for the cytoplasm while other sequences are polyadenylated but not transferred.

Animals↗
PubMed1976

Diversity of sequences in total and polyadenylated nuclear RNA from Drosophila cells.

Complementary DNA was synthesized using polyadenylated nuclear RNA of cultured Drosophila cells as template. The kinetics of hybridization of this cDNA with nuclear RNA indicated that the complexity of this RNA population is five to ten times greater than that of cytoplasmic mRNA. The same difference in the fraction of DNA represented was obtained when nuclear and cytoplasmic RNA were hybridized with labeled unique sequence DNA. The fraction of the DNA sequences represented in total number of polyadenylated nuclear RNA is much higher than that represented in cytoplasmic RNA.

Base Sequence↗
PubMed1976

Fatal illness in general practice.

In an investigation of fatal illness during a 12-month period in a practice of 5,897 patients in Glasgow, 58 deaths (42 male, 16 female) were recorded. Malignant neoplasms and myocardial infarction in male patients of 50 years and over accounted for 27 (46.6 per per cent) of the deaths. Thirty (51.7 per cent) of the deaths took place in hospital. Fifteen (25.9 per cent) of the deaths were sudden. In patients dying in hospital of malignant, cardiac, and respiratory disease the duration of the terminal stay in hospital represented a small proportion of the total duration of the illness, the principal burden of their care falling upon their families and community resources.In an integrated health service much yet remains to be accomplished in co-ordinating the efforts of hospital and community teams in caring for the fatally ill patient.

Adolescent↗
PubMed1976

Structure-activity relationships of some selected beta-adrenergic blocking agents--oxidation with N-bromosuccinimide.

A relationship between in vitro rate of oxidation by N-bromosuccinimide (NBS) and the pharmacologic activity (pA2) of different beta-adrenergic blockers for different blocking agent-tissue combinations has been studied. The rates of oxidation of the alcoholic group in the drugs by NBS, as well as their molecular conformations as represented by molecular models, were studied in order to determine requirements for selectivity and potency of action of beta-adrenergic blocking agents. Using data from all 7 drugs studied--both nonselective and selective blocking agents--no significant correlation between pA2 and -log k2 (k2 is the second order rate constant for the oxidative reaction) was found. If data from only the 4 nonselective agents were used (16 drug-tissue combinations), a correlation significant at p less than 0.01 was found. Hypotheses are presented to account for the selective action of some beta-adrenergic blocking agents.

Adrenergic beta-Antagonists↗
PubMed1976

A study of bereavement in general practice.

Forty six bereaved relatives were assessed by a general practitioner four to eight weeks after the bereavement. In 36 (78.3 per cent) the immediate reaction to bereavement was one of numbness or stupefaction; in seven (15.2 per cent) emotional relief occurred; and in three cases (6.5 per cent) there was no obvious immediate reaction. The numbness reaction was limited in duration to a week or less in 31 of the 36 instances.At four to eight weeks after bereavement 29 (63.0 per cent) of the subjects continued to experience difficulty in coming to terms with their loss. Twenty subjects reported guilt feelings and a similar number expressed aggressive reactions. The bereaved subjects tended to increase their consumption of cigarettes and alcohol, while their appetite and weight tended to be reduced. Thirty six (78.3 per cent) of the subjects reported physical symptoms, notably headache, dizziness, generalised aches, and abdominal complaints.THE MOST PROMINENT PSYCHOLOGICAL FEATURES OF BEREAVEMENT WERE FOUND TO BE: preoccupation with thoughts of the deceased, idealisation of the lost person, depressive mood, and loneliness.The findings are discussed and reference made to the role of the family doctor in the management of bereavement reactions.

Adolescent↗
PubMed1975

Antagonistic effects upon cutaneous circulation of muscular excercise and exposure to a high ambient temperature.

Measurements were made in man of heart rate (Fc), arterial blood pressure (Pa), cutaneous blood flow (Z) (by plethysmography of the hand) as well as variation sin venous volume (deltaV) in the course of muscular exercise of 70 Watts intensity corresponding from 48% to 60% of the maximal oxygen consumtion of the subjects. These exercises were carried out at ambient temperatures of 22 degrees and 29 degrees C. for 8 min. In every case, an initial lowering of the Q and deltaV followed by a progressive climb was found. The average maximal reduction in output was virtually identical at 22 degrees and 29 degrees C (4.10 +/- 2.05 and 4.00 +/- 2.31 ml/min. 100 cm3). But the average maximal fall in volume turned out to be less at 29 degrees C (0.30 +/- 0.40 ml/100 cm3) than at 22 degrees C (0.60 +/- 0.60 ml/100 cm3). The resistive sector of cutaneous circulation conserves the same vasomotor capacities at the two ambient temperatures studied; the cutaneous capacitive sector shows lower reactivity at the higher ambient temperature. This would suggest that diminished venous return may be partially responsible for poor tolerance to exercise in warm climates.

Adult↗
PubMed1975

Oncogenic transformation of primary hamster cells by herpes simplex virus type 2 (hsv-2) and an hsv-2 temperature-sensitive mutant.

Six oncogenically transformed cell lines were obtained following infection of hamster embryo fibroblasts with UV-irradiated herpes simplex virus type 2 (HSV-2) or with an HSV-2 temperature-sensitive mutant. All lines produced undifferentiated fibrosarcomas in newborn hamsters, four of the six lines produced metastatic tumors in the lung, and sera from tumor-bearing hamsters contained neutralizing antibody to HSV-2. HSV-specific cell-surface antigen (s) was detected by immunogluorescence tests in all six of the lines established from primary tumors. Antibody to an early, HSV-specific, non-structural polypeptide (VP134) reacted by immunofluorescence with antigen(s) in fixed preparation of three of the six tumor-cell lines.

Animals↗
PubMed1975

Pathophysiology of acupuncture: nervous system transmission.

As far as we know, this is the first scientific report which shows distinctly that acupuncture is transmitted directly by the nervous system and the performance of analgesic acupuncture requires an intact nervous system. The more distal the acupuncture treatment is given upon the nerve, the greater the degree of analgesia is afforded. The slowing from a normal awake beta to a normal awake alpha electroencephalographic rhythm may have some effect on the patient's pain perception but further investigation is required.

Acupuncture Therapy↗