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Biomedical subjects

M Smith

Publications and source records attributed to M Smith.

At least 1,351 records · Page 75Linked to original sources
PubMed1977

Nucleotide sequence of the 3' terminal third of rabbit alpha-globin messenger RNA: comparison with human alpha-globin messenger RNA.

Rabbit and human alpha-globin complementary DNA was synthesized using the primer (dT10)dGdCdC hybridized to globin mRNA with reverse transcriptase, and sequenced using the plus and minus gel sequencing procedure (Sanger and Coulson, 1975; Brownlee and Cartwright, 1977). The complete 3' noncoding region, 89 nucleotides in length, and one third of the coding region of rabbit alpha-globin mRNA have thus been sequenced. These data are compared with the near complete 3' noncoding region sequence of human alpha-globin mRNA obtained in these and previous studies. The two mRNAs are approximately 80% homologous in their 3' noncoding regions, except that the human sequence has an insert of 24 nucleotides. A very similar insert in sequence has been described in human beta-globin mRNA (Proudfoot, 1977).

Animals↗
PubMed1977

Enzymatic synthesis of oligonucleotides of defined sequence: synthesis of a segment of yeast iso-1-cytochrome c gene.

The deoxyribooligonucleotide, d(pT-T-A-G-C-A-G-A-A-C-C-G-G), constituting a segment of yeast iso-1-cytochrome c gene, has been synthesized by a combination of chemical and primarily enzymatic methods. The starting primer, d(pT-T-A-G1, was chemically synthesized by the phosphodiester method and was extended stepwise, by reactions catalyzed by polynucleotide phosphorylase.

Cytochrome c Group↗
PubMed1977

Cleavage specificity of the restriction endonuclease isolated from Haemophilus gallinarum (Hga I).

The nucleotide sequences in the replicative form (duplex) of phiX174 DNA around six sites cut by Hga I, a restriction endonuclease from Haemophilus gallinarum, have been compared. The enzyme produces a staggered cleavage resulting in a pentanucleotide 5'-terminal extension. The sequences within and immediately surrounding the pentanucleotide cleavage site have no obvious relationship. However, the sequence 5'-G-A-C-G-C-3' 3'-C-T-G-C-G-5' occurs five nucleotide pairs to the left of the cut in the upper strand and 10 nucleotide pairs to the left of the cut in the lower strand and, therefore, is believed to constitute the recognition site. This is a member of the class of restriction endonucleases in which recognition and cleavage sites lack 2-fold rotational symmetry. The method used to define the cleavage site is of general applicability.

Base Sequence↗
PubMed1977

Sequence analysis of the 3' non-coding region of mouse immunoglobulin light chain messenger RNA.

Using an oligonucleotide d(pT10-C-A) as primer, cDNA has been transcribed from the 3' non-coding region of mouse immunoglobulin light chain mRNA and sequenced by a modification1 of the 'plus-minus' gel method2. The sequence obtained has partially corrected and extended a previously obtained sequence3. The new data contains an unusual sequence in which a trinucleotide is repeated seven times.

Animals↗
PubMed1977

Immunoglobulin production by human-mouse somatic cell hybrids.

Studies on immunoglobulin production in human-mouse somatic cell hybrids suggest: 1. The structural genes for heavy chain immunoglobulins are carried on chromsome 6, probably on the short arm or the proximal half of the long arm of the chromosome. 2. The structural gene for kappa light chain immunoglobulin may be carried on chromsome 11. 3. The occurrence of immunoglobulin molecules on the cell surface requires the presence of chromosome 2.

Animals↗
PubMed1977

[Pathogenetic left tracheal bronchus. A review of the literature in connection with four cases (author's transl)].

The so-called left "tracheal" bronchus is usually found to be a transposition of the segmental apicoposterior bronchus of the upper left lobe onto the terminal portion of the main trunk. This systematisation abnormality is less common on the left than on the right. In our experience, based on 1,500 bronchographs carried out on adults and children, we have discovered seven left "tracheal" bronchi four of them associated with an obstructive emphysema in the same area. Although this malformation is rarely encountered in the etiologies of interlobular or poly-segmental emphysemas in children, it does however appear that an upper left emphysema has two etiologies which are peculiar to it: segmental bronchial atresia and left "tracheal" bronchi. Why the left "tracheal" bronchi is more often pathogenetic in comparison with the right is open to speculation. As in many other examples of tracheo-bronchial compression for vascular reasons, the close contact between the hyperarterial ectopic bronchi and the left pulmonary artery seems, logically, to be the culprit.

Adolescent↗
PubMed1976

The red blood cell esterase D polymorphism in Europe and Asia.

Several regional series from Britain and 3 Asian series were typed for the Esterase D polymorphism. It was found that haemolysates up to 5 years old could be reliably typed when prepared from washed anticoagulated red blood cells. Lysates prepared from blood clots do not retain Esterase D activity quite as well. The Manx population has higher Esterase D 2 gene frequencies than neighbouring populations. A Nepalese population exhibits the highest Esterase D 2 gene frequency so far recorded. The other series presented supplement or confirm results already published.

Asia, Western↗
PubMed1976

The effect of beta adrenergic blockade upon exercise-induced changes in blood coagulation and fibrinolysis.

Exercise stress is known to stimulate blood coagulation and fibrinolysis possibly as a result of sympatho-adrenal stimulation of the beta adrenergic receptor. In order to test this hypothesis five men exercised on four separate occasions with and without prior beta adrenergic blockade with oxprenolol, propranolol and pindolol. The increase in plasma adrenaline and noradrenaline concentration was much greater during exercise under beta blockade but activation of fibrinolysis was enhanced as well. Factor VIII levels did not change significantly during any of the experiments. These results suggest that the activation of fibrinolysis by exercise is not mediated by the beta adrenergic receptor. The influence of beta adrenergic blockade on the change in factor VIII with exercise was inconclusive.

Adrenergic beta-Antagonists↗
PubMed1976

Studies on the lymphocytes of sheep. I. Recirculation of lymphocytes through peripheral lymph nodes and tissues.

Recirculating lymphocytes were collected from the efferent ducts of peripheral somatic nodes and incubated in vitro with 51Cr. After washing, the labeled cells were returned to the sheep by i.v. injection. The partitioning of the labeled cells between blood and efferent (intermediate) lymph, or between efferent and afferent (peripheral) lymph was monitored for the next 24 h by assaying the radioactivity in appropriate samples of cells. The labeled lymphocytes took several hours to migrate through the nodes so that they equilibrated between blood and lymph in about 10 h. This pattern was not altered grossly during the inductive phase of an immune response. The small numbers of lymphocytes which migrated through peripheral tissues entered the lymph at least quickly as those that migrated through lymph nodes.

Animals↗
PubMed1976

Sperm proteinase release during fertilization of rabbit ova.

Proteinase activity was found to be present along the sides of sperm penetration tunnels through the zonae pellucidae of rabbit ova using silver-proteinate staining techniques. This is the first direct confirmation of the generally accepted concept of sperm penetration by proteinase release and digestion of the zona pellucida.

Acrosin↗
PubMed1976

Measurement of personality traits and their relation to patient satisfaction with complete dentures.

1. There was a high incidence of the personality traits of hypochondriasis, depression, hysteria, and manifest anxiety in the 70 complete denture patients of this study. 2. Most patients in this study were satisfied with the complete dentures received. 3. There was no significant relationship between the personality traits of hypochondriasis, depression, hysteria, and manifest anxiety and the degree of patient satisfaction with dentures. 4. There was no significant relationship between the personality traits of hypochondriasis, depression, hysteria, and manifest anxiety and the techinical quality of dentures. 5. There was no significant relationship between the technical quality of complete dentures and the degree of patient satisfaction with the same dentures.

Consumer Behavior↗
PubMed1976

Culture of Schistosoma haematobium in vivo and in vitro.

The maximum rate of development of Schistosoma haematobium in the hamster was determined by examination of the most advanced worms recovered at short intervals throughout the course of development. In culture S. haematobium developed at the same rate as in the hamster up to day 31 when pairing first occurs and male worms produce some spermatozoa. In vitro males formed some spermatozoa but pairing did not take place and, probably for this reason, females did not complete sexual maturation as occurs in the host between days 57-65. Somatic growth continued in vitro and at 70 days male worms had achieved almost the same length as in the hamster at this time. The culture medium, previously used for S. mansoni, consisted of equal volumes of serum and Earle's balanced saline with a final concentration of 0.25% lactalbumin hydrolysate, 100 units/ml penicillin, 100 mug/ml streptomycin and 1% rbc. The best culture results were obtained with one particular human serum; seven other human sera gave a wide range of growth support. The samples of baboon, rhesus monkey or foetal calf sera tested provided little or no growth support but prolonged survival was possible in all the sera.

Animals↗