Streptomycin retards the phenotypic maturation of chick myogenic cells.

As part of an effort to optimize conditions required for the complete maturation of muscle cells in vitro, we have investigated the effects of the antibiotics penicillin, streptomycin, and Fungizone (amphotericin B) on the development of cultured chick embryo skeletal muscle. It is shown that even low dosages of streptomycin, but not penicillin or Fungizone, retard protein synthesis and accumulation in these cultures. Myosin accumulation was also reduced and the appearance of striations in fused cells was delayed in myotubes formed in medium containing streptomycin.

The role of protein phosphorylation at tyrosine in transformation and mitogenesis.

In cells transformed by avian sarcoma viruses or stimulated by growth factors, certain polypeptides become phosphorylated at tyrosine residues. It is not known if these cellular polypeptides are phosphorylated directly by the tyrosine-kinase activities which are associated with the viral transforming proteins and with growth factor receptors. It is also not clear if phosphorylation of these polypeptides is required for viral transformation or the response to growth factors.

Membrane association of a 36,000-dalton substrate for tyrosine phosphorylation in chicken embryo fibroblasts transformed by avian sarcoma viruses.

A cellular protein of 36,000 daltons becomes phosphorylated at tyrosine in chicken embryo fibroblasts transformed with avian sarcoma viruses. We have used cellular fractionation and immunofluorescence to locate the 36-kdalton protein in virus-transformed and uninfected chicken fibroblasts. The 36-kdalton protein in transformed cells fractionated mainly with high-speed particulate material, and in density gradient separations, the 36-kdalton protein was found in association with light density membranes together with most of the plasma membrane marker.

Outcome of meningococcal group B meningitis.

Sixty children who survived meningitis during the outbreak of meningococcal group B infection in Bolton 1971-74 were assessed between 5 and 9 years later. Each case, together with a matched control, has been examined clinically and subjected to a number of psychological tests and to routine audiology. The results, unlike those from other series, did not demonstrate any incoordination, ataxia, or other physical abnormality, nor was there any statistically significant impairment on psychological testing.

Continuous cervical dilatation monitoring by ultrasonic methods during labor.

Continuous recording of cervical dilatation during labor has been investigated in 13 pregnancies. The recordings were obtained with an ultrasonic cervimeter that continuously monitors cervical dilatation from the transit time of ultrasound signals between two piezoelectric crystals attached on the uterine cervix. A small spring-loaded clip allowed each crystal to be fixed on the rim of the cervical os.

Mental distress in mothers of pre-school children in inner London.

The level of mental 'distress' was assessed for a sample of mothers with pre-school children in Inner London. Fifty-two per cent of mothers had a moderate or severe distress problem in the 12 months prior to interview. Variables correlating with distress were identified and replicated in a second sample.

Evaluation of an impedance measurement technique for uterine contraction recording.

An electronic system for the detection of uterine contractions by impedance measurement was evaluated in 30 subjects during the first stage of labor. The advantage of the system was patient comfort and ease of application of the recording electrodes. Simultaneous recordings of uterine contraction activity with conventional extra- or intra-uterine recording systems were made.

The differential diagnosis of the short-limbed dwarfs presenting at birth.

Attention is drawn to the fact that in a number of types of short-limbed dwarfism a precise diagnosis can be made in the neonatal period. Examples are given and the prognostic and genetic implications are discussed. It is important to be able to advise parents of the likely outlook for the infant and of the genetic implication.

Effect of elective induction of labor with prostaglandins F2alpha and E2 and oxytocin on uterine contraction and relaxation.

Prostaglandins F2alpha and E2 and oxytocin were used to induce labor in 101 patients at risks. The data show that the three drugs are efficient labor inducers. The success rate of induction is the highest in primiparous patients receiving oral prostaglandin E2.

Messenger RNA for myosin polypeptides: isolation from single myogenic cell cultures.

Messenger RNA which stimilates the synthesis of myosin heavy chain in a reticulocyte lysate has been isolated from single myogenic cell cultures. Specific myosin polypeptides have been identified by immunoprecipitation with an antibody made to purified adult chicken skeletal muscle myosin. This mRNA binds to oligo(dT)-cellulose, and an active fraction from sucrose gradients migrates as 26S on formamide-polyacrylamide gels.

Is cystic fibrosis an acid mucopolysaccharidosis?

A case of cystic fibrosis with myocardial fibrosis and acid mucopolysaccharide deposits in the myocardium is described. The case supports the theory that cystic fibrosis may be a genetic acid mucopolysaccharidosis.

Bacterial metabolism of 4-chlorophenoxyacetate.

1. A pseudomonad capable of utilizing 4-chlorophenoxyacetate (CPA) as sole source of organic carbon was isolated from soil. 2.