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Biomedical subjects

A Porter

Publications and source records attributed to A Porter.

At least 109 records · Page 6Linked to original sources
PubMed1982

Disciplinary attitudes and cigarette smoking: a comparison of two schools.

Two British boarding schools for boys with different disciplinary policies in respect of cigarette smoking were identified. Questionnaires were sent to the young "old boys" of each school to determine their present smoking habit and most were returned (school A 81%, school B 83%). Significantly more responders smoked who had been to the less strict school (school A 39%, school B 30%, p less than 0.05). These figures probably underestimate the smoking prevalence in the two complete groups. The results suggest that measures that reduce the exposure of an uncommitted adolescent to peer group smoking decrease the chances of tobacco dependence in adulthood.

Adolescent↗
PubMed1982

Propranolol in angina pectoris. Comparison of long-acting and standard-formulation propranolol.

In a double-blind, crossover study in 20 patients with stable angina pectoris, the effects of long-acting propranolol, 160 mg administered once daily for 4 weeks, were compared with those of standard propranolol, 40 mg given four times daily for 4 weeks. The patients suffered no adverse effects when they were switched between treatment schedules. The average number of episodes of angina during the 4 weeks on long-acting propranolol was 7.3 and on standard propranolol. 6.3. Average nitroglycerin consumption was 5.8 and 4.9 tablets during therapy with these two drug programs. The resting values for heart rate, systolic blood pressure and rate-pressure product were similar when determined 25.4 hours after a dose of long-acting propranolol and 10.7 hours after standard propranolol. When the patients exercised at these times, patients on long-acting propranolol and standard propranolol had similar walking times to the onset of angina and to the development of moderate angina. The values for heart rate, systolic blood pressure and rate-pressure product were similar at rest and during exercise during these two treatment programs. We conclude that long-acting propranolol administered in a dose of 160 mg daily is as effective as 50 mg of standard propranolol four times daily.

Angina Pectoris↗
PubMed1980

Cardiovascular responses in hypertensive outpatients starting oral propranolol, determined from the brachial pulse upstroke.

Simultaneous measurement of brachial artery pressures, systolic time intervals, initial pulse upstroke gradient and pulse rate was made in 7 adult hypertensive outpatients during rest supine and during bicycle ergometry at 2 different work rates. Measurements were repeated after 1, 6 and 13 wk on oral propranolol 80 mg thrice daily. Rise of pulse upstroke period (reversed after 1 wk) and of inflection time--analogous with preejection period--and fall of inflection, or diastolic, pressure (most marked at 1 wk) can be explained by early reduction of myocardial contractility and pulse rate. The fall of upstroke period, of peak, or systolic, pressure and of pulse rate (more marked after 1 wk) is related to a later 'adaptive' decrease in peripheral resistance. Much useful information can be obtained by such simple examination of the characteristics of the pulse wave in the brachial artery without complex, albeit noninvasive, cardiac investigations.

Administration, Oral↗
PubMed1978

The 3'-Terminal nucleotide sequence of encephalomyocarditis virus RNA.

Poly(A)-containing encephalomyocarditis virus RNA functions as an excellent template for cDNA synthesis in vitro with an RNA-dependent DNA polymerase in the presence of an oligothymidylate primer. Under appropriate conditions, discrete transcripts of increasing chain length were obtained, suitable for sequence analysis. A limited cDNA fragment of 36 nucleotides, primer (dT)10 included, was synthesized when dGTP was omitted from the reaction mixture and its primary structure was elucidated using direct DNA-sequencing methods. The complement corresponds to the 3' end of encephalomyocarditis RNA. The hexanucleotide (5'-3')(A-A-U-A-A-A) found in this sequence is also present in all 3' non-coding regions of poly(A)-containing eukaryotic mRNAs studied until now, in nearly identical positions relative to the poly(A) tail. The possible biological significance of this structural homology is discussed.

Base Sequence↗
PubMed1977

[Severe accidental acrolein intoxication in the home (author's transl)].

In a private household overheated fat-containing food emitted vapours which caused severe intoxication in a previously healthy man. The resulting pulmonary changes presented a grave threat to the patient's life for several days. The origin and properties of the vapours led to the conclusion that acrolein was their major toxic component.

Accidents, Home↗
PubMed1976

Size and location of poly (A) in encephalomyocarditis virus RNA.

Encephalomyocarditis (EMC) virus RNA contains a covalently bound sequence of polyriboadenylic acid (poly(A). This was determined by two-dimensional gel electrophoresis of complete T1 and pancreatic RNase digests of formamidesucrose gradient-purified RNA and subsequent analysis of the product by alkaline hydrolysis. The size of the EMC virus genomic poly(A) sequence was estimated by formamide-polyacrylamide gel electrophoresis of the RNase-resistant product, or by [3H-]poly(U) hybridization to freshly purified virion RNA, to be, on average, 40 nucleotides in length. The evidence obtained from [3H-]isoniazid labelling and other experiments would indicate that the poly(A) sequence is located at the 3'-terminus of EMC virus RNA.

Base Sequence↗
PubMed1976

Defective-interfering particles of Semliki Forest virus: intracellular events during interference.

Purified defective-interfering (DI) particles of Semliki Forest virus are unable to carry out any of the steps in virus multiplication except uncoating. Cells co-infected with DI particles and standard virus contain several virus-specified RNA species (DI particle-specific species) absent from cells infected with standard virus alone. Moreover, synthesis of all the virus-specified components distinctive of standard virus-infected cells is reduced. The DI particle-specific RNA species comprise two poly A-containing single-stranded RNAs (DIss1 and DIss2), identical to those found in purified DI particles, two double-stranded RNA'S (RFs) and a new size class of replicative intermediate (RI). Hybridization experiments showed that the nucleotide sequences of DIss1 and DIss2 (i) are present in the 42S genome of standard virus but absent from the 26S RNA- the RNA from standard virus-infected cells which encodes the structural proteins of the virion (Clegg & Kennedy, 1975 a) and (ii) are complementary to the negative strands of the DI paritcle-specific RFs and RI. Oligonucleotide fingerprinting revealed extensive nucleotide sequence homology between DIssI and DIss2. Analysis of the mRNA complement of standard virus-infected, co-infected and uninfected cells strongly indicated that neither DIss1 nor DIss2 can serve as a functional messenger RNA. From these studies we propose a mechanism for the multiplication of and interference by DI particles of Semliki Forest virus.

Base Sequence↗
PubMed1975

Myoglobinemia following acute myocardial infarction.

Myoglobin was identified in the serum of 11 of 21 patients after myocardial infarction by a sensitive specific complement fixation technic. This method allowed detection of as little as 0.03 mug of myoglobin. The assay tended to underestimate small concentrations of myoglobin due to serum interference. Myoglobinuria occurred with myoglobinemia but did not reflect the level of myoglobinemia or the duration of elevated serum levels. Larger amounts of myoglobin, 0.4 mug/ml or greater, were found in patients with severe infarctions, three of four of whom died as a result of this illness.

Animals↗