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Biomedical subjects

R Richards

Publications and source records attributed to R Richards.

At least 109 records · Page 6Linked to original sources
PubMed1987

Ocular motility disturbances following trauma.

Disturbances of ocular motility following trauma are manifested by diplopia and faulty ocular rotations which frequently require an abnormal head position for fusion. Motility imbalance may occur following injury to the eye alone, to the eye and associated extraocular muscles, and to the orbital walls, and also following closed head trauma. The clinical findings early following injury may be very different from the clinical picture several months following injury. The diagnosis of abnormal motility includes the use of forced ductions, saccadic velocity recording, active force generation, measurements of deviations of the eyes in the cardinal positions of gaze as well as the use of computed tomography (CT scan) and ultrasonic techniques. The presence of slipped or lost muscles must be diagnosed, and evaluation of restricted rotations and paretic muscles is essential. The treatment of motility disturbance includes relief of restricted rotations by lysis of adhesions and lengthening or recessing appropriate muscles as well as strengthening underacting muscles by resection and/or advancement. In cases of severe trauma one must not overlook injury to the eye itself in addition to the motility disturbance.

Eye Injuries↗
PubMed1986

Iron state in alpha and beta thalassaemia trait.

The iron state was examined in two groups of pregnant women who were carriers of alpha and beta thalassaemia genes. In both groups the haematological expression of the disease--namely, haemoglobin and mean cell haemoglobin concentrations--was nearly identical. In patients with alpha thalassaemia the ferritin concentrations and percentage of ferritin deficiency was the same as in normal pregnant patients, whereas in those with beta thalassaemia the ferritin concentrations were usually much higher and iron deficiency four times less common. This variance appears to be explained by different degrees of extravascular or intravascular haemolysis between the two thalassaemias as assessed by the activities of serum alpha hydroxybutyrate dehydrogenase.

Adult↗
PubMed1986

Red cell genetic abnormalities in Peninsular Arabs: sickle haemoglobin, G6PD deficiency, and alpha and beta thalassaemia.

The frequencies of four major red cell genetic defects, sickle haemoglobin (Hb S), glucose 6 phosphate dehydrogenase deficiency (G6PD), and alpha and beta thalassaemia, have been determined in nearly 5000 subjects from the three major Peninsular Arab States, namely Yemen (North and South), the United Arab Emirates, and Oman. All four defects are common with an overall pattern of alpha thalassaemia greater than G6PD deficiency greater than beta thalassaemia greater than Hb A/S. However, the frequencies of these within each state varies and they are, respectively, Oman: 0.389, 0.328, 0.024, and 0.038; the United Arab Emirates: 0.165, 0.087, 0.017, and 0.019; and Yemen: 0.065, 0.062, 0.0624, and 0.0095. Two, namely alpha thalassaemia and G6PD deficiency, are extremely common, but in spite of this there appears to be a lack of observed clinical disease. For example, Hb H disease and Barts hydrops fetalis were not seen and the oxidative haemolytic syndromes are rare.

Adult↗
PubMed1985

Bronchial beta-adrenoceptor blockade following eyedrops of timolol and its isomer L-714,465 in normal subjects.

The R-enantiomer of timolol, L-714,465, is considerably less potent as a beta 1- and beta 2-adrenoceptor antagonist in animals than timolol, whilst only slightly less potent in reducing intraocular pressure. If the same was true in man L-714,465 would have potential benefits over timolol in the treatment of glaucoma. The extent of bronchial beta-adrenoceptor blockade following one eyedrop in each eye of timolol 1% and L-714,465 1% was compared in six normal subjects, by measuring the displacement of the bronchodilator dose-response curve to isoprenaline following each drug compared to the isoprenaline dose-response curve after placebo eyedrops (methyl-cellulose). There was no significant difference between the dose-response curves to L-714,465 and placebo, but a significant displacement of the dose-response curve following timolol. The geometric mean dose ratio following timolol (21) differed significantly from that following L-714,465 (1.6). Heart rate at the end of the isoprenaline dose-response study was lower after timolol, despite the fact that subjects had received higher doses of isoprenaline. The trend was in the same direction after L-714,465 when compared with placebo though less marked. L-714,465 clearly causes less beta-adrenoceptor blockade than timolol when given as 1% eyedrops. The effects of L-714,465 1% on the airways and heart rate did not differ significantly from placebo in these six subjects but the pattern of response would be most consistent with L-714,465 having some beta-adrenoceptor blocking activity though considerably less than timolol.

Adrenergic beta-Antagonists↗
PubMed1985

Thalassaemia genes in Peninsular Arabs.

The haematological indices of Peninsular Arabs (United Arab Emirate Nationals, Yemeni and Omani) have been examined. The most outstanding feature, seen in 40-50% of all subjects, was one of hypochromia, microcytosis associated with erythrocytosis. In approximately 5% the hypochromia was severe (MCH 19-22 pg) and 20% of these were found to have beta thalassaemia trait. In 10% of subjects the hypochromia was moderate (MCH 23-24 pg) and beta thalassaemia was confirmed in only 10%. The remaining 25% had a mild hypochromia (MCH 25-27 pg) and no beta thalassaemia was detected. The cause of the hypochromia in subjects with a normal Hb A2 (30% of the total population) is probably alpha thalassaemia, firstly because in those patients with an MCH of 19-24 pg the other haematological parameters are statistically the same as those with proven beta thalassaemia and, secondly, in those with an MCH of 25-27 pg iron deficiency is not common (6% of the population). The degree and pattern of the distribution of hypochromia of the three major ethnic groups of the Peninsular Arabs could be explained either by different alpha and beta thalassaemia genes being operative or by different degrees of inbreeding of the same genes.

Adolescent↗
PubMed1985

Thalassaemia trait and pregnancy.

The haematological variables, haematinic state, and placental function of more than 2000 pregnant women, heterozygous for either alpha- or beta-thalassaemia genes, were examined during pregnancy. Four features emerged. Firstly, it was possible by discriminant function analysis of haematological variables to distinguish in pregnant patients between the anaemia caused by thalassaemia trait and that caused by iron deficiency. Secondly, patients with thalassaemia become significantly more anaemic in pregnancy, beta more than alpha, but this was mainly due to plasma dilution. From the data percentile curves were drawn for each type of thalassaemia which predicted the patients' expected "normal" haemoglobin throughout gestation. Thirdly, patients with alpha-thalassaemia had the same incidence of iron deficiency as normal pregnant patients, whereas in those with beta-thalassaemia it was four times less common. The incidence of folic acid and vitamin B12 deficiency was the same in all groups. Finally, as assessed by serum oestriol concentration, there did not appear to be any abnormality of placental function or fetal development associated with maternal thalassaemia, and, also, there seemed to be no increase in maternal or fetal morbidity in pregnancy.

Adult↗
PubMed1982

Monitoring ophthalmology graduate education. The Residency Review Committee.

Formal monitoring of quality control in American graduate medical education is the task of the residency review committees (RRCs). The RRC for ophthalmology consists of nine members appointed by the American Board of Ophthalmology, the American Academy of Ophthalmology, and the American Medical Association. The RRC meets twice each year to determine the accreditation status of residency training programs. As of 1978, the residents ae board eligible only if they have graduated from accredited programs. The review process is based on data collected in standard hospital information forms and a site survey. An RRC member evaluates this information and makes a recommendation that is discussed and voted on by the nine-member RRC body. In response to pressures for greater quality control and regulatory visibility, the review process has been bolstered by improvements in the data-gathering forms and in the surveyors and by a revision of the minimum requirements for accreditation that provides clearer and more stringent guidelines.

Accreditation↗
PubMed1982

Periarteritis nodosa and pregnancy.

Pregnancy in patients with periarteritis resulted in maternal death in 7 of the 8 cases that have been reported. In the present case, periarteritis was in remission throughout the pregnancy; the patient was thus the second known maternal survivor. The infant also did well. It is suggested that pregnancy probably does not have as direct an effect on the course of the disorder as appears from the outcome of the previous cases. Extreme caution must prevail, especially as diagnosis is often difficult and experience so limited.

Adult↗
PubMed1980

Cell cycle-dependent replication of the DNA of minute virus of mice, a parvovirus.

The formation of double-stranded viral DNA was examined in synchronized cells infected with minute virus of mice in early G1 phase. In the infected cells, a minimum of 50-100 copies of the input single-stranded DNA have been converted to a double-stranded form by mid S phase. In well-synchronized cells, the amount of double-stranded form by mid A phase. In well-synchronized cells, the amount of double-stranded viral DNA detected during G1 is on the order of a few copies per cell or less. When cells are infected in the presence of the thymidine analog, 5-bromodeoxyuridine, viral DNA synthesis is inhibited. However, 5-bromodeoxyuridine does not inhibit host DNA synthesis nor does it prevent replication of viral DNA if added to the infected cells in late S phase. Viral DNA replication first becomes resistant to 5-bromodeoxyuridine inhibition at the beginning of S phase. As 5-bromodeoxyuridine appears to specifically block early steps in viral DNA synthesis but not the subsequent replication of the DNA, the conversion of the input viral genome to a double-stranded form which undergoes further replication appears to be a S phase-specific event.

Animals↗
PubMed1979

Biochemical and haematological changes in Sydney's the Sun City-to-Surf fun runners.

Before this study was undertaken, biochemical and haematological changes in collapsed fun runners have been interpreted only by comparison with changes observed in trained marathon runners, or by comparison with normal subjects. This study was undertaken to establish the pattern of biochemical and haematological changes to be expected in non-collapsed fun runners as a result of competition, and to use this pattern as the basis for comparison with changes observed in collapsed fun runners after similar competition. Forty-three fun runners (28 males, 15 females) who competed in the 1978 City-to-Surf run volunteered as non-collapsed "controls", while 10 runners (nine males, one female) who collapsed during the 1978 City-to-Surf run became "casualties" for comparison. Blood for detailed analysis was collected from the controls two weeks before the 1978 City-to-Surf run, immediately after the run and one month later; blood from the casualties was collected immediately after the run, and one month later. As a result of competition, three patterns of changes were observed, namely, haemoconcentration; tissue damage and altered organ system function; and alteration in carbohydrate metabolism. More intense tissue damage probably accounts for disproportionate changes of some variables in male controls compared with female controls, and in casualties compared with controls. Casualties differed most from controls in degree fo depression of serum bicarbonate levels, and degree of elevation of blood urea nitrogen, serum creatinine, uric acid and bilirubin levels. A wide scatter of blood sugar levels immediately after run both in controls and in casualties reflects the stress of prolonged exertion.

Adult↗
PubMed1979

Management of heat exhaustion in Sydney's the Sun City-to-Surf run runners.

Heat exhaustion (collapse with rectal temperature of, or higher than 38 degrees C) is the most common major medical complication of fun runs and is caused by dehydration and impaired heat loss with, or without, hypoglycaemia. All patients with heat exhaustion after the City-to-Surf runs from 1977 to 1979 were managed in a medical centre established at the finish of the course. Several methods of management of heat exhaustion are evaluated. Patients were allocated retrospectively to four primary treatment groups: (i) treated with ice-wet towels only; (ii) treated with ice-wet towels and intravenously administered fluids; (iii) treated with intravenously administered fluids and ice-cold packs applied to the neck, axillae, and groins; and (iv) treated with intravenously administered fluids only. There was no death or prolonged morbidity in any treatment group. In Group 1 (n=11), the mean initial rectal temperature was 40.2 +/- 1.5 degrees C. There were insufficient data to assess the mean time taken for the temperature to fall to 38 degrees C. In Group 2(n=16), the mean initial rectal temperature was higher than 40.9 +/- 1.1 degrees C. In three patients, the temperature failed to fall to 38 degrees C within 90 minutes. For the remainder, the mean time taken for the temperature to fall to 38 degrees C was 30 minutes. In Group 3 (n=16), the mean initial rectum temperature was higher than 41.2 +/- 1.0 degrees C. One patient, who had been febrile immediately before the run, was discharged with a temperature of 38.8 degrees C. For the remainder, the mean time taken for the temperature to fall to 38 degrees C was 36 +/- 10 minutes. In Group 4 (n=13), the mean initial rectal temperature was 39.6 +/- 1.1 degrees C and the mean time taken for the temperature to fall to 38 degrees C was 21 +/- 16 minutes. Heat exhaustion in fun-run casualties may be safely and effectively treated by rapid intravenous infusion of fluids with, or without, application of cold packs to the neck, axillae, and groins. The application of ice-wet towels is contraindicated.

Adolescent↗