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Biomedical subjects

A Richardson

Publications and source records attributed to A Richardson.

At least 361 records · Page 20Linked to original sources
PubMed1977

British and West African facial form in ideal occlusion.

True lateral cephalometric radiographs of 20 adult male British subjects and 20 Nigerian adult males were collected. All subjects showed an ideal occlusion of the teeth. These radiographs were analysed using a facial polygon joining the points Nasion, Sella, Articulare, Gonion and Menton. Additionally, measurements were made of the axial inclination of the incisor teeth and the distances from the incisal edges and apices of the teeth to the facial plane. Statistical examination of the results using "t" tests revealed that the average British mandible had a longer ramus but shorter body joined at a wider angle than the Negro, that the nasal part of the face was longer on average in the British group and that the incisor teeth, on average, projected further and were inclined further forward in the Nigerian group. A linear discriminant function in only three variables predicted with 100 per cent accuracy membership of the two groups. The three variables were the mandibular body length, the height of the nasal part of the face, and the amount by which the incisal edges of the lower incisor teeth projected beyond the facial plane.

Adult↗
PubMed1977

Partial trisomy 8 (trisomy 8q2106 leads to 8qter).

A case of trisomy for part of the long arm of chromosome 8, confirmed by G-banding analysis, in a white male infant is described. The mother carried a reciprocal translocation between chromosome 8 and chromosome 13 (46,XX,t(8;13),(q21:q34). The patient had inherited the translocated chromosome 13 and was thus trisomic for the distal half of the long arm of chromosome 8. He had many of the clinical features of the full trisomy 8 syndrome. As compared with previously reported cases with trisomy of the distal end of chromosome 8, he was more dysmorphic and showed greater developmental retardation.

Abnormalities, Multiple↗
PubMed1977

Tymodonts.

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Dental Equipment↗
PubMed1977

America 1976.

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Communication↗
PubMed1976

Stereochemistries of geometric isomers of 4-(2-bromo-1,2-diphenylvinyl)phenol, 4-(2-bromo-1,2-diphenyylamine: corrections of the literature.

The stereochemistries of geometric isomers of 4-(2-bromo-1,2-diphenylvinyl)phenol, 4-(2-bromo-1,2-diphenylvinyl)anisole, and 2-[p-(2-bromo-1,2-diphenylvinyl)phenoxy]triethylamine were determined by conversion of the phenolic analog to the ethers and subsequent comparison of physical properties with those of 2-[p-(2-chloro-1,2-diphenylvinyl)phenoxy]triethylamine of known stereochemistry.

Chemical Phenomena↗
PubMed1976

Characterization of a temperature-sensitive mutant of Saccharomyces cerevisiae that undergoes uncontrolled protein synthesis.

A mutant of Saccharomyces cerevisiae, DW137, isolated after treatment of a wild-type strain with ICR-170. The mutant was respiration-deficient and showed abnormal cell division when grown at 30 degrees C. In addition, the mutant was temperature-sensitive and underwent lysis when grown at 37 degrees C. Random spore analysis, induced reversion profiles, and complementation analysis indicated that the abnormal phenotypes were under the control of a single recessive mutation caused by a base-pair substitution in a nuclear gene. Macromolecular analysis of the mutant at permissive and restrictive temperatures showed that at restrictive temperatures the mutant cannot synthesize DNA. Surprisingly, at restrictive temperatures, protein synthesis in the mutant continued at a rate greater than that observed at permissive temperatures. Cell death and lysis of the mutant could be prevented by treatment of cultures with cycloheximide, an inhibitor of protein synthesis. The data suggest that the abnormally high rate of protein synthesis and the inability to synthesize DNA are jointly responsible for death of the cells, and most probably play and integrating role in the incipient cell lysis.

Cell Division↗
PubMed1976

Stereotactic limbic leucotomy--a follow-up at 16 months.

Sixty-six patients were assessed clinically, psychologically and physiologically before operation, at six weeks and at a mean of 16 months following stereotactic limbic leucotomy. Seventy-three per cent were clinically improved at six weeks and 76 per cent at 16 months. In obsessional neurosis, 89 per cent of patients showed definite clinical improvement at 16 months; in chronic anxiety, 66 per cent were improved; in depression, 78 per cent; and in the small number of schizophrenics treated the improvement rate was over 80 per cent. Self-assessment and observer-assessment questionaires and scales measuring Depression, Anxiety, Neuroticism, Hysterical symptoms and Obsessional symptoms and traits all showed highly significant reductions of mean scores at 16 months. There was no fall-off in intelligence, and adverse effects were minimal. Limbic leucotomy, with its enhanced accuracy and safety, compares very favourably with similarly assessed, more extensive 'free-hand' procedures, and in obsessional neurosis and chronic anxiety the results are superior.

Adult↗
PubMed1976

Computerized axial tomography: estimation of spatial and density resolution capability.

The spatial and density resolution capability of the EMI-Scanner device for computerized axial tomography has been determined in vitro. For density differences greater than +/-1 per cent the spatial resolution is 6 X 6 mm. For density differences of 3 per cent and greater the resolution is 3 X 3 mm. Density resolution is at least +/-1 per cent for objects greater than 1 cm. Preliminary data on in vitro measurement of X-ray linear attenuation coefficients in tissue biopsies and standard solutions are given, together with the early results of enhancement of tissue density differences in vivo. Implications of this new technique for an in vivo neuropathology are suggested.

Brain Diseases↗
PubMed1975

Combined craniofacial resection for malignant disease.

A combined craniofacial approach has been employed in nineteen patients with tumors involving the base of the skull. Monoblock resection of the temporal bone, anterior fossa, or anterior and middle fossa can be achieved with acceptable mortality, even in cases of advanced cancer that recurs after radiation. Immediate reconstruction with a full thickness flap was routinely employed to provide improved cosmesis and to minimize the risk of intracranial infection.

Adult↗
PubMed1975

Outbreaks of bovine salmonellosis caused by serotypes other than S. dublin and S. typhimurium.

Outbreaks of salmonellosis caused by serotypes other than S. dublin and S. typhimurium were investigated on 41 farms in north-west England. Of these, 37 (90 per cent) were in dairy cows. There was strong circumstantial evidence that contaminated dairy cake was the source of infection in at least four herds and probably many more. Twenty-six serotypes were encountered with S. newport, the commonest, causing the most severe disease. Most cattle seemed to rid themselves of infection during the following months whether or not they were at pasture, housed in cubicles or in byres. Some cows excreted salmonellas for up to 11 months after the disease outbreak. Associated human salmonellosis was confirmed on 3/41 (7 per cent) of the farms.

Animals↗
PubMed1975

Triarylpyridylethanols and triarylpyridylethylenes. Chemistry and antifertility effects.

Triarylpyridylethanols were prepared by condensing the corresponding diaryl ketones and diarylmethanes. The ethylenes were obtained by the acid-catalyzed elimination of H2O from the ethanols. In the absence of electron-donating substituents, acid treatment of the carbinols resulted in predominant cleavage to starting ketone. The compounds were tested for their antifertility effects in pregnant hamsters. The most active compound was carbinol 3, which, at 30 mg/kg, prevented all of the treated animals from maintaining their pregnancies.

Animals↗