PubMed Health⌕ Search

Biomedical subjects

D A Griffiths

Publications and source records attributed to D A Griffiths.

At least 55 records · Page 3Linked to original sources
PubMed1976

A reappraisal of the Pfannenstiel incision.

The postoperative morbidity of incisions used in retropublic prostatectomies was examined. 350 patients with vertical midline incisions were compared with 411 patients with transverse or Pfannenstiel incisions. There was a significantly increased incidence of postoperative inguinal hernias in the group of patients who had had transverse incisions. The possible reasons for this were discussed. It was concluded that the normal architecture of the inguinal canal was deformed and weakened by extra-wide transverse incisions.

Abdominal Muscles↗
PubMed1976

The fine structure of conidial development in the genus Torula. III. T. graminis Desm.

Torula graminis produced blastoconidia in acropetalous chains after the evagination of a characteristic conidiogenous cell. Conidia consisted of up to 15 cells and their cell wall was differentiated into an outer melanized zone and an inner hyaline zone. A consistent cytoplasmic feature of conidial cells was the presence of dictyosomal-like membranous stacks often closely associated with the nucleus. Vesicles that developed from the dictyosomal-like cisternae were probably involved in conidial wall synthesis.

Cell Wall↗
PubMed1976

The fine structure of conidial development in the genus Torula. IV. T. thermophila Cooney & Emerson.

Torula thermophila produced typical chlamydospores either as intercalary chains within prostrate hyphae or as terminal swellings on short, lateral, hyphal branches. Mature chlamydo-spores were spherical, dark brown, smooth-surfaced structured structures with thick, single-layed cell walls (= secondary wall layer) usually differentiated into an outer electron-dense zone and an inner electron-transparent zone. Disarticulation and sport release occurred after the disintegration of the original hyphal wall. The thallospores of T. thermophila arise in a manner different from the blastospores produced by other species of Torula and are structurally more closely related to the spores produced by Humicola insolens. However until further work has been completed on spore development in the Torula-Humicola complex of fungi the name T. thermophila is retained.

Cell Wall↗
PubMed1975

Effects of live weight and energy intake on nitrogen balance and total N requirement of lambs.

1. Results of 298 nitrogen balance studies from experiments with male cross-bred lambs, ranging in weight from 3 to 38 kg, which had been either fasted, or fed entirely on liqid diets of varying protein content at various energy intakes up to ad lib. intake, were used to quantitatively describe the effects of the amount and quality of absorbed protein, energy intake and live weight on N balance and total N requirement of lambs. 2. When N intake was less than the amount required, N balance was independent of energy intake, but linearly related to absorbed N and metabolic body-weight (live weight-O-75). In the fitted relationship, the coefficient of absorbed N was shown to be an estimate of the biological value of absorbed protein and the coefficient of metabolic body-weight was an estimate of the loss of endogenous N in both urine and faeces. For the milk-based diets used in the experiment biological value was 0-72 and the total endogenous N loss in urine and faeces was 148 mg N/kg per d. 3. When N intake was in excess of the amount required, N balance in lambs of a constant live weight increased linearly with metabolizable energy (ME) intake, at a rate that decreased with increasing live weight. Similarly at constant ME intake, N balance was a curvilinear decreasing function of metabolic body-weight, it was constant for lambs of all weights when ME intake was about 0-23 MJ/kg-0-75 per d, but it decreased linearly with increasing metabolic body-weight for ME intakes above this level. 4. N balance of fasted lambs was several times less than predicted by either of the relationships established for fed animals, and was found to be linearly related to metabolic body-weight. 5. The effects of energy intake and live weight on the total N requirement of lambs were determined. When total N requirement was expressed per unit of energy intake, it was found to be constant at 0-9 g N/MJ ME for all lambs irrespective of live weight when ME intake was 0-23 MJ/kg-0-75 per d. However, as ME intake/unit metabolic body-weight was raised above this level, N requirement/unit ME intake increased for lambs weighing less than c. 23 kg, but decreased for heavier animals.

Animal Nutritional Physiological Phenomena↗
PubMed1975

Case methods in teaching organization of medical care.

This paper describes the use of case methods in teaching the organization of medical care on the two year masters course in social medicine at the London School of Hygiene and Tropical Medicine. The basic characteristics of the subject and of case methods are related and the teaching implications of their similarities discussed. Terminology and different kinds of case methods are introduced and the objectives of using them on the course are outlined. A brief specimen case report is given to illustrate the use of the case methods approach in practice. It is emphasized that the effective development and use of case methods requires suitable materials, preparation, and teaching skills, and a list of the basic requirements is given. It is concluded that case methods of teaching have generally achieved their objectives on the course and have been well received by the students.

Curriculum↗
PubMed1975

Melanin deposition in the hyphae of a species of Phomopsis.

Hyaline hyphae of Phomopsis become pigmented when exposed to short periods of light. Pigment was deposited in the form of melanin granules both within the cell wall and within mucilaginous excrescences that were developed irregularly over the hyphal surface. Analysis of the pigment showed it to have properties similar to that of "Dopa" melanin and to pigments previously isolated from fungal cell walls. Lysis of both hyaline and pigmented hyphal walls by means of lytic enzymes was minimal. It is suggested that the major role of melanin in this fungus is the protection of cellular organelles from harmful ionizing radiations.

Cell Wall↗
PubMed1975

The development and structure of thick-walled, multicellular, aerial spores in Diheterospora chlamydosporia (=Verticillium chlamydosporium).

The aerial, thick-walled spores in Diheterospara chlamydosporia arose as terminal swellings on erect hyphae. Repeated septation of the continuously swelling spore resulted in a multicellular structure. Immediately after the onset of septation secondary wall material was laid down between the two-layered primary wall and the plasmalemma. The presence of secondary wall material indicates that the multicellular spore is a dictyochlamydospore and not an aleuriospore. The relationship between chlamydospores and aleuriospores in other fungi is discussed.

Cell Membrane↗
PubMed1975

The fine structure of conidial development in the genus Torula. I. T. herbarum (Pers.) Link ex S. F. Gray and T. herbarum f. quaternella Sacc.

Conidiogenesis in Torula herbarum and T. herbarum f. quaternella was observed by scanning and transmission electron microscopy. Conidia of the former were shown to be made up of three equally sized cells capped by a distinctive, and easily recognizable, conidiogenous cell. Conidiogenous cells also arose terminally on erect hyphae and on prostrate hyphae. The single-layered conidial cell walls were differentiated into an inner hyaline zone and an outer electron-dense zone formed by the deposition of melanin. Conidiogenous cells lacked melanin at the apex and, before conidiation, the lateral walls were strengthened by a further deposition of melanin. The apex bulged outwards and was modified into a new multicelled conidium bearing another apical conidiogenous cell. Continued development of new conidia resulted in an acropetal chain which became disarticulated after cytolysis within the conidiogenous cell. The relative distinctions between holoblastic and enteroblastic development are discussed and it is concluded that the conidia should be referred to as blastoconidia.

Cell Wall↗
PubMed1975

The fine structure of conidial development in the genus Torula. II. T. caligans (Batista and Upadhyay) M. B. Ellis and T. terrestris Mistra.

Conidia of Torula caligans (Batista & Upadhyay) M. B. Ellis comb.nov. and T. terrestris Misra were examined by transmission- and scanning-electron microscopy. Torula caligans produced four-celled conidia in which the central cells were distinctly larger than the basal and apical cells. Conidia of T. terrestris were 4- to 7-celled long and ellipsoidal in shape. Conidiogenous cells in both species developed melanin only within the lowermost part of the lateral walls while the other cells of the conidium were uniformly melanized around the circumference of the cell; melanin in these cells being deposited within, at least, half the width of the cell wall. In both species new conidia arose from evagination of the hyaline apex of the conidiogenous cell and are therefore blastoconidia. The systematic relationships between T. caligans and T. terrestris and other species of the genus Torula are discussed.

Cell Wall↗