The Chepstow feeding aid

A specially designed spoon or scoop has been developed to enable controlled amounts of semi-solid food to be accurately and easily inserted into the mouth. This device simplifies feeding following major surgery for intra-oral cancer. Its use and other possible applications are described.

Monoclonal antibodies protect against respiratory syncytial virus infection in mice

Twenty-five monoclonal antibodies (Mab) to respiratory syncytial virus (RSV) and two to hepatitis B virus were inoculated intravenously into mice. Twenty-four hours later the mice were challenged intranasally with RSV. Eleven of 14 Mab against fusion protein and four out of six Mab against a larger glycoprotein (GP84) significantly reduced the titre of RSV in the lungs when mice were killed 5 days later. Five Mab against three other RSV proteins and two Mab against hepatitis B virus had no significant effect on RSV infection. These results indicated that serum IgG against one epitope on the fusion protein and another on the larger glycoprotein (GP84) will completely protect mice against challenge. These epitopes are primary candidates for an RSV vaccine produced by techniques of gene cloning and peptide synthesis.

Factors affecting the choice of anesthesiology by medical students for specialty training

To learn some of the reasons why anesthesiology as a specialty is not preferred by more graduating medical students and to determine the effects of various factors on their specialty choice, the authors studied the number of medical students who chose anesthesiology as a specialty after graduation and the quality of clerkships available in various departments. The study established that medical students do not find anesthesiology as attractive as other specialties and that several factors are related to the students' choice of anesthesiology. Most surprising was the negative effect of the presence of certified registered nurse anesthetists on the operating room floor. These results suggest the need for a thorough study of the use of nurse practitioners, physician's assistants, and nurse-clinicians, at least where teaching of medical students is taking place.

Peptide inhibitors of renin

Analogues of renin substrate that incorporated a non-cleavable isostere at the scissile bond are powerful inhibitors of renin both in vitro, and in animals and man.

The fate of excess beta-globin chains within erythropoietic cells in alpha-thalassaemia 2 trait, alpha-thalassaemia 1 trait, haemoglobin H disease and haemoglobin Q-H disease: an electron microscope study

Electron microscope studies have been performed on bone marrow cells from individuals with various alpha-thalassaemia syndromes. Globin chain precipitates were rarely found in the erythropoietic cells of a subject with alpha-thalassaemia 2 trait. By contrast, such precipitates were found in 0.6 - 1.3% of the erythroblast and marrow reticulocyte profiles in two cases of alpha-thalassaemia 1 trait, 2.1 - 13.7% of profiles in five patients with haemoglobin H (HbH) disease and 6.2% of profiles in one patient with haemoglobin Q-H (HbQ-H) disease. In the patient with HbQ-H disease, but not in the others, the nuclei of some erythroblasts displayed the 'Swiss cheese' appearance which has been reported in some forms of congenital dyserythropoietic anaemia. It is proposed that in alpha-thalassaemia 2 trait, where the degree of excess of beta-chains is slight, most of the excess chains are degraded by proteolysis. In alpha-thalassaemia 1 trait, where there is a greater excess of beta-chains, the excess chains can undergo either proteolysis or precipitation, but there is little or no tetramerization to form soluble HbH. Finally, in HbH disease, where the degree of excess is considerable, the excess beta-chains may be subject to proteolysis, precipitation and tetramerization.

Production and characterization of monoclonal antibodies to tetanus toxin

Monoclonal antibodies against tetanus toxin were produced to obtain highly specific antisera. Ten hybridoma cell lines producing monoclonal antibodies were derived from the fusion of rat myeloma cells and spleen cells from rats immunized with tetanus toxoid. Eight produced monoclonal antibodies specific for determinants on toxin and toxoid, whereas two were specific only for determinants on the toxoid. The antibodies produced by hybridomas were characterized by determination of the class of light and heavy chain components, epitope specificity, toxin neutralization, and subunit specificity. All of the antibodies contained kappa light chain, eight contained the gamma 1 heavy chain, and the remaining two contained the gamma 2a heavy chain. Five distinct epitopes were indicated by competition assay of paired monoclonal antibodies, and 4 of the 10 monoclonal antibodies neutralized the in vivo activity of tetanus toxin. The four neutralizing monoclonal antibodies and one other were specific for the C fragment of the heavy chain of the toxin molecule.

Respiratory syncytial virus infection in mice

The A2 strain of human respiratory syncytial virus replicated in the nose and lung of BALB/c mice, with virus growing to higher titers in older animals than in younger animals. Virus was recovered from the nose between days 2 and 7 with peak titers on days 3 and 4, and from the lungs between days 2 and 9, with peak titers on days 4 through 6. Serum antibody developed 2 weeks after infection. Viral antigen was demonstrated in the alveolar cells of the lung by immunofluorescence. Histopathological changes included infiltration by mononuclear cells of the peribronchiolar and perivascular tissue, some interstitial thickening, and formation of multinucleated giant cells. Virus could not be recovered from the respiratory tract of mice inoculated with bovine strains of respiratory syncytial virus. Growth of the A2 strain of human respiratory syncytial virus in different cell lines affected its infectivity for mice. Infection of BALB/c mice with respiratory syncytial virus provides a highly reproducible model for the study of the pathogenesis of and mechanisms of immunity to this virus.

New inhibitors of human renin tested in vitro and in vivo in the anaesthetized baboon

A new inhibitor of human renin (H. 189) is described. It is a decapeptide analogue of human renin substrate with the amino acid, statine, substituted for leucine in the scissile bond. Its inhibitory potency as shown by IC50 is 1.0 X 10(-8) M with human plasma renin and 1.5 X 10(-8) M with baboon plasma renin. It is less effective with dog and rat renin, but its inhibitory potency with human renin is similar to that of another inhibitor of ours (H. 142) having a reduced isostere in the scissile bond. H. 189 has some inhibitory effect on cathepsin D (IC50 6.5 X 10(-5) M) but H. 142 has no discernible effect. Pepstatin, on the other hand, was highly effective against cathepsin D (IC50 1.2 X 10(-8) M). H. 142 and H. 189 were infused intravenously at 10 mg/kg/h in four anaesthetized salt-deplete baboons (Papio hamadryas). The activity of renin in plasma decreased markedly as did the circulating concentration of its products, angiotensin I and angiotensin II.

Language and social class: is verbal deprivation a myth?

A study was made of complex usages of language in the spontaneous conversation of 30 4-year-old girls, their mothers and their teachers, at home and at school. There were significant social class differences in frequency, but almost all the usages appeared in the talk of almost all the mothers and children at least once. The working class girls' language style changed more between home and school than did that of the middle class girls. The teachers' talk contained a higher proportion of these usages than the mothers', but the overall input to the children was less at school. The findings are discussed in relation to Labov's argument that verbal deprivation is a myth.

An assessment of cerebral dominance in language--disordered children via a time-sharing paradigm

A time-sharing paradigm was used to assess language lateralization in language-disordered and normal children aged 4-7 years. Several expressive language tasks as well as a vocal, but nonlinguistic, task were administered concurrently with unimanual finger tapping. Dependent variables were percent disruption scores and number of syllables produced per concurrent trial. All language concurrent tasks produced tapping reductions for both hands for both groups. This result contrasts to similar time-sharing studies claiming asymmetrical interference and hence language lateralization in children (N. White & M. Kinsbourne, 1980, Brain and Language 10, 215-223; J. Obrzut, G. Hynd, A. Obrzut, & J. Leitgeb, 1980, Brain and Language 11, 181-194). A multiple regression analysis revealed a significant interaction effect differentiating language-disordered from normal children. Normals exhibited a parallel response pattern for speech and tapping (both increased or decreased in rate) under all lateralization conditions. Language-disordered children exhibited an inverse response pattern (e.g., if speech output increased, tapping rate decreased) only under left-hemisphere time-sharing.

Children's questions and adults' answers

Radio-recordings were made of the conversation of 30 girls, aged just under four, at school with their teachers and at home with their mothers. Half the girls were middle class and half working class. The frequency and type of question asked by the children and the frequency and type of answer given by the adults were analysed. Particular attention was paid to passages of persistent questioning by the child. There were home-school and social class differences in all these measures. The significance of the findings for education is discussed.

Radiation-induced lethality and mutation in a repair-deficient CHO cell line

A U.V.-sensitive, DNA repair-deficient mutant of Chinese hamster ovary cells was tested for its response to the lethal effects of X-irradiation and simulated solar light, and to the mutagenic actions of X-rays. A slight sensitivity to killing by X-rays and a greater sensitivity to solar light was observed relative to the wild-type CHO cells. More mutations were induced at a given dose of X-rays in the sensitive cell line than in the wild-type. These results are interpreted in terms of overlap in the repair processes which take place after U.V. damage in mammalian cells with those that take place after other types of radiation damage.

Peptide inhibitors of renin

Three experiments are described using new substrate analogue inhibitors of renin. The first experiment shows that introduction of a reduced isostere in the scissile peptide bond of an analogue greatly increases its ability to inhibit renin of a particular species. However, different species of renin substrate have different amino acids in their scissile bond and variation here also greatly influences the affinity of renin and substrate and hence of renin and substrate analogues. Finally, substitution of amino acids in the C-terminal adjacent to the scissile bond influences the affinity and efficacy of substrate analogues as inhibitors. In our second experiment a peptide inhibitor of dog renin, H.77, was used in an affinity column to produce a one-stage, 2000-fold, and complete purification of human renin. In our third experiment infusion of H.77 was used to lower circulating concentrations of angiotensin I and angiotensin II in conscious sodium-deplete dogs. Captopril was then given in addition to H.77 but blood pressure did not fall further, suggesting that captopril lowers blood pressure wholly or partly by reducing angiotensin II within the circulation and in extravascular sites.

A new case of congenital dyserythropoietic anaemia, type III: studies of the cell cycle distribution and ultrastructure of erythroblasts and of nucleic acid synthesis in marrow cells

The clinical and laboratory findings in an asymptomatic 19-year-old Welshman with congenital dyserythropoietic anaemia (CDA) type III are described. The blood film showed macrocytosis and red cell fragmentation and there was biochemical evidence of intravascular haemolysis. The bone marrow showed erythroid hyperplasia, megaloblastic erythropoiesis and several giant multinucleate erythroblasts. Some mononucleate erythroblasts were large and had relative DNA contents of 4-8c and the bi- and multinucleate erythroblasts had total DNA contents of 2-16c. Some of the multinucleate erythroblasts displayed a variety of ultrastructural abnormalities, including marked differences in the appearances of the individual nuclei within the same cell. The marrow cells gave a normal deoxyuridine-suppressed value indicating that the megaloblastic changes were not caused by an impairment of the methylation of deoxyuridylate. The rates of incorporation of 14C-glycine and 14C-adenine into both the DNA and RNA of bone marrow cells were within the normal range. Furthermore, the average rate of elongation of newly-synthesised, 3H-thymidine-labelled daughter DNA strands, assessed by hydroxyapatite chromatography of alkali-denatured DNA was found to be normal. The results suggest that there is no impairment of DNA replication in the majority of the erythroblasts and that the abnormality of erythropoiesis resulted from disturbances during mitosis and the G2 phase.