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Biomedical subjects

D Howel

Publications and source records attributed to D Howel.

28 records · Page 2Linked to original sources

Effect of birthplace on infants with low birth weight.

From December 1983 to June 1985, 162 infants of less than 32 weeks' gestation or weighing less than 1,500 g, or both, were cared for at the regional neonatal intensive care unit in Leeds. Of the 162, 64 (40%) were born in the unit because their mothers had received antenatal care there, 58 (36%) were born in another hospital and subsequently transferred, and 40 (25%) were transferred in utero because of potential complications. The overall mortalities for each group were 14%, 38%, and 18% respectively. These differences were significant, but when they were corrected for gestation, birth weight, and mode of delivery there was no difference in either the mortality or the incidence of intraventricular haemorrhage in the three study populations. Although there seem to be no distinct advantages of in utero transfer in terms of mortality and morbidity, there are other psychological and emotional advantages.

England

F-responses in syringomyelia.

Motor and sensory nerve conduction and various F-response parameters have been examined in the median and ulnar nerves bilaterally in 22 patients with syringomyelia. Excluding those nerves with isolated peripheral lesions, motor and sensory conduction was normal in the distal nerve segments, except for one subject in whom severe wasting of the muscles was associated with slowed motor velocities. Minimum and/or maximum F-response latencies were increased in one or more nerves in 16 of the 22 cases, which was attributed to disturbed function of anterior horn cells and the intraspinal segment of the motor fibres, or mild subclinical nerve trauma. There was a tendency for F-response amplitude and duration to be increased, probably reflecting the combined effects of spasticity and enlargement of motor units due to reinnervation.

Adult

Site variation in anthralin inflammation on forearm skin.

The effect of application site on anthralin inflammation was measured at 10 clinically normal volar skin sites on each forearm of 31 subjects as the increase in skin thickness at 48 h using Harpenden calipers. Pre-treatment and increase in skin thickness were significantly related to application site. Pre-treatment thickness increased distally and laterally by an amount depending on sex, and to a lesser extent other factors, whilst the increase in skin thickness values was greater proximally, laterally and on the right arm but was not affected by age, sex or skin type. When increases in skin thickness values were adjusted for pre-treatment thickness, the difference between proximal and distal sites was lost but there was still a significant difference between the medial and lateral aspect and the right and left arms. The absolute differences were small but demonstrate the need to use symmetrical forearm skin sites and randomized treatment sides when comparing the effects of topical agents on anthralin inflammation.

Adolescent

Which drug for the adult epileptic patient: phenytoin or valproate?

A series of 140 previously untreated patients with tonic-clonic or partial seizures were randomised to receive either phenytoin or sodium valproate. There was no difference between the treatment groups in pretreatment variables that might influence outcome. Sodium valproate and phenytoin in the treatment of tonic-clonic or partial seizures showed no difference in efficacy as regards time to two year remission or time to first seizure. When the possible prognostic factors were studied, including history and results of clinical examination and investigations before treatment; the only factor which influenced the proportion of patients achieving two year remission was type of seizure. Patients with a clinical history of partial seizures did significantly less well than those with a history of tonic-clonic seizures only. This study showed no major difference in efficacy between sodium valproate and phenytoin in adults with recent onset of epilepsy, irrespective of the type of seizures that the patient suffered.

Adolescent

F-response behaviour in a control population.

Various parameters of the F-response including minimal and maximal latency, chronodispersion, amplitude (absolute and F%M) and duration have been determined for a sample of 20 responses in the median and ulnar nerves bilaterally in normal healthy subjects of both sexes aged between 12 to 81 years. Side to side comparisons revealed no significant differences in any of the parameters except for slightly longer minimum F latencies in the right median nerve. Strong correlations were found between minimal and maximal F latencies and height, while much weaker relationships were found between these parameters and age. There was a slight but significant relationship between F%M and age, but no age or sex related changes were noted for any of the remaining F-response parameters.

Adolescent

F-responses: a study of frequency, shape and amplitude characteristics in healthy control subjects.

Characteristics of the surface recorded F-response, including frequency, occurrence of identical responses, shape and amplitude have been investigated in the ulnar nerve of control subjects. During a train of 200 stimuli, F-response frequency varied between 50% and 93% in different subjects with a mean of 79%. The vast majority of responses (96.6%) occurred only once; of those responses which repeated, 89.5% occurred between 2-5 times, 9% between 6-10 times and only 1.5% 11 or more times. F-response shape was variable, the majority containing two or more negative peaks. F-response amplitudes tended to be a relatively small proportion of the compound M-response, with median F%M values ranging from 0.8% to 4%. The data suggest that a large proportion of surface recorded F-responses following supramaximal stimulation are composed of recurrent discharges derived from more than one motor unit.

Adult

The IgG subclass distribution of thyroglobulin antibody synthesized in culture.

Thyroglobulin autoantibodies synthesized by Hashimoto lymphocytes in culture and present in serum have been analysed in terms of their IgG subclass distribution. The autoantibodies produced in vitro were frequently IgG4 or IgG1, whether pokeweed mitogen or Epstein-Barr virus was used to stimulate the cultures, and the subclass distribution of these thyroglobulin antibodies was similar to that observed in the patients' serum. It appears therefore that the antibodies synthesized in vitro in response to polyclonal B-cell activators resemble those produced in vivo, and it seems likely that both pokeweed mitogen and Epstein-Barr virus influence the same B-cell precursors of autoantibody-synthesizing cells, albeit by different mechanisms.

Adolescent