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Biomedical subjects

I Smith

Publications and source records attributed to I Smith.

At least 343 records · Page 19Linked to original sources
PubMed1981

Hyperphenylalaninaemia of various types among three-quarters of a million neonates tested in a screening programme.

A total of 795 382 infants born in north London was screened for phenylketonuria using the Guthrie test between October 1969 and December 1978. During this period it became recognised that phenylketonuria is not a single disease entity but one that encompasses a number of disorders of differing clinical and biochemical severity. The overall incidence of persistent hyperphenylalaninaemia was of the order of 7 per 100 000 births (or 1 in 15 000) and all the early treated patients made normal developmental progress. During the study there was an appreciable fall in the incidence of uncomplicated transient hyperphenylalaninaemia with or without tyrosinaemia. This reduction coincided with the change in infant feeding practice in the UK which led to lower intakes of protein and phenylalanine. It was concluded that any infant found to have a persistent blood phenylalanine concentration of 240 mumol/1 (4 mg/100 ml) or greater should be followed closely.

Amino Acids↗
PubMed1980

Effects of oestrogens on erythrocyte enzyme efflux in normal men and women.

In the normal female range for serum creatine kinase, the large diminutions associated with the reproductive period and with pregnancy are apparently related to oestrogen production. Specimens of heparinised blood from healthy men and women were stressed by chilling, and showed the predictably large efflux of erythrocyte aldolase and lactate dehydrogenase into plasma. In aliquots of the same specimens simultaneously stressed in the same way, previous substitution of the natural plasma with pregnant plasma rich in oestrogens gave a marked significant reduction in the efflux of both enzymes in women, but not in men. The significance of these findings is discussed.

Adolescent↗
PubMed1980

Genetics and physiology of the rel system of Bacillus subtilis.

Stringent factor (ATP:GTP-3' pyrophosphotransferase) has been purified from wild type Bacillus subtilis and it has been shown that guanosine tetra- and pentaphosphate (ppGpp and pppGpp) are synthesized in vitro in the presence of ribosomes, unacylated tRNA and its specific codon, as has been demonstrated in Escherichia coli. relA, the genetic determinant for the stringent factor, has been mapped on the B. subtilis chromosome by transduction and is found between aroD and leu. The relC locus, defined by mutations which were originally selected by resistance to thiostrepton, has been mapped adjacent to spoOH in the order cysA, spoOH, relC, rif. Sringent factor and ribosomes are functional for the in vitro synthesis of (p)ppGpp in early stages of sporulation (up to at least 4 h). This contradicts the findings of other laboratories.

Bacillus subtilis↗
PubMed1980

Outpatient laparoscopic sterilisation: Comparison between electrocautery and clip application.

In a personal prospective series of 504 day-case laparoscopic sterilisations in 1977-78, unipolar tubal electrocoagulation was compared with spring-loaded clip application. Two patients who had cautery required laparotomy because of serious bleeding and one because of accidental bowel diathermy. Clip application was free from serious complications, but caused more post-operative pain. The majority of patients were performing normal or light household duties within 24 hours of sterilisation.

Adult↗
PubMed1980

Mucoepidermoid carcinoma in the mandible: report of case.

Mucoepidermoid carcinoma, a salivary gland tumor arising centrally within the jaws, is rare. The literature concerning this tumor has been reviewed. Diagnosis and treatment of a case in 44-year-old man has been presented.

Carcinoma↗
PubMed1979

Ribosomal protein alterations in thiostrepton- and Micrococcin-resistant mutants of Bacillus subtilis.

Ribosomal proteins of parental thiostrepton- and micrococcin-sensitive Bacillus subtilis cysA14 and thiostrepton-and micrococcin-resistant mutants were compared. Several electrophoretic and immunochemical techniques showed unambiguously that BS-L11 was not present on 50 S ribosomal subunits from the six thiostrepton-resistant mutants. Protein BS-L11 reappeared in all six revertants from thiostrepton resistance to thiostrepton sensitivity. No definitive protein alteration could be ascribed to the mutation from micrococcin sensitivity to resistance. It was also demonstrated that B. subtilis protein BS-L11 is homologous to Escherichia coli ribosomal protein L11. The finding that ribosomes from thiostrepton-resistant mutants do not contain protein L11 suggests that L11 not only is involved in binding of thiostrepton, but also, when mutationally altered, confers resistance to this antibiotic. Although the ribosomes of these strains do not contain protein L11, all thiostrepton-resistant mutants showed the same viability as the parental strain. Thus protein L11 cannot be obligatory for the structure and function of the ribosome.

Anti-Bacterial Agents↗
PubMed1979

Fetal damage despite low-phenylalanine diet after conception in a phenylketonuric woman.

A woman with phenylketonuria gave birth to an infant with a cardiac defect and microcephaly despite introduction of a low-phenylalanine diet 5 weeks after conception (3 weeks after the first missed period). In maternal phenylketonuria fetal damage leading to reduced brain growth and cardiac malformations probably occurs within a few weeks of conception.

Abnormalities, Multiple↗
PubMed1979

Chromosomal mutations causing resistance to tetracycline in Bacillus subtilis.

We have isolated, after ethylmethanesulfonate mutagenesis, several chromosomal mutations causing resistance to tetracycline in Bacillus subtilis. These mutations fall into two classics, tetA and tetB. 30 S ribosomal protein S10 shows an altered mobility on two-dimensional acrylamide gels in cells bearing the former type of mutation. Ribosomes from these cells show elevated levels of resistance to tetracycline in vitro as measured by polyuridine dependent polyphenylalanine synthesis. The tetA locus maps adjacent to the tuf gene in the B. subtilis ribosomal protein gene cluster. Cells with the tetB mutation do not show any altered ribosomal protein, and their ribosomes are as sensitive, in vitro, to tetracycline as ribosomes isolated from wild type cells. The tetB mutation has been mapped proximal to cysA14.

Bacillus subtilis↗
PubMed1979

RNA synthesis during spore germination in Bacillus subtilis.

We have analyzed the RNA synthesized during spore germination in Bacillus subtilis. Early in germination there is little incorporation of [3H]uridine into RNA. A large increase in incorporation into RNA was found at 45--60 min into germination which was in part due to increases in the specific activity of the UTP pool. When corrected for specific activity changes, the instantaneous rate of RNA synthesis showed a seven to tenfold increase between 30 and 45 min of germination. Polyacrylamide gel electrophoresis studies showed that the RNA synthesized during germination appeared very similar to the RNA made during vegetative growth. DNA-RNA hybridization studies indicated that mRNA and rRNA were synthesized throughout germination. Their relative proportions remained constant and were very similar to the composition of RNA synthesized during vegetative growth.

Bacillus subtilis↗