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Biomedical subjects

R M Harrison

Publications and source records attributed to R M Harrison.

At least 109 records · Page 6Linked to original sources
PubMed1980

Physicochemical speciation of lead in drinking water.

Recent studies have highlighted the importance of drinking water as a route of human exposure to lead. Whilst there are ample data on lead concentrations in drinking water, little is known of its physical and chemical forms (physicochemical speciation). Such information is important as the speciation of ingested lead influences the efficiency of absorption from the gastrointestinal tract. Knowledge of speciation should also provide a fuller understanding of the factors controlling the solubility of lead in potable waters and hence assist in devising the most cost-effective means of plumbosolvency control. We have determined experimentally the speciation of lead in three different tapwaters and report here diverse forms of dissolved and particle-associated lead, dependent primarily on the chemical matrix of the raw water.

Cations↗
PubMed1980

Semen parameters in Macaca mulatta: ejaculates from random and selected monkeys.

Semen samples were collected by rectal probe electroejaculation techniques from groups of adult male rhesus monkeys. Mean values for 249 ejaculates from 100 monkeys were a sperm concentration of 419.43 x 10(6)/cm3 with 53.9% of the sperm showing progressive movement. Sperm concentration showed a positive rank correlation coefficient with sperm motility. Significant motility and concentration differences were found among groups. Seasonal differences were noted but were not significant. The study provides data that will aid investigators who are screening animals for studies involving reproductive potential.

Animals↗
PubMed1980

Contact scrotal thermography. II. Use in the infertile male.

The results of the use of a new contact scrotal thermographic instrument in 112 patients in a fertility clinic are presented. Animal studies comparing accuracy to Thermistor probe measurements show strong positive correlation. This modality is useful for evaluation of patients with persistently abnormal semen analyses after a varicocele ligation to determine which patients might benefit from invasive retrograde venography to detect persistent venous trunks. Patients with a questionable varicocele or "subclinical" varicocele comprise the group that benefits most from this diagnostic instrument. There were 24 patients in this category, and the results of contact scrotal thermography are discussed. Three of these patients have had high ligation of the spermatic vein on the basis of these studies and the results have been good.

Animals↗
PubMed1979

Toxic metals in street and household dusts.

Street and household dusts have been sampled within the Lancaster area (U.K.), and analysed for Pb, Cd, Cr, Co, Cu, Ni and Zn. The concentration of each metal has been determined both as total and extractable metal, the latter referring to metal soluble in a 0.07N hydrochloric acid solution. The results are discussed in relation to the sources of the metals, and possible health hazards to children exposed to the dusts.

Child↗
PubMed1979

Contact scrotal thermography: application to problems of infertility.

Traditionally, studies on the relationship between scrotal or testicular temperature and infertility have concerned patients with varicoceles. However, some varicoceles are difficult to palpate and, in fact, there now appears to be an entity called subclinical varicocele. These data have led to the development of a new diagnostic tool, a contact thermography camera, which is inexpensive in comparison to infrared thermography units, is portable and provides consistent permanent recordings of scrotal temperature. The initial use of this camera in 30 patients seen in an infertility clinic is reported.

Body Temperature↗
PubMed1978

Vasectomy in rhesus monkeys. III. Light microscopic studies of testicular morphology.

Rhesus monkeys were randomly assigned to undergo various surgical procedures. The animals were followed from one to sixty-six weeks postvasectomy, at which time they were sacrificed and their tissues prepared for light and electron microscopy. Vasectomy in the rhesus monkey, as in certain other species, appears to be a procedure not attended with widespread testicular atrophy or histologic evidence of impaired spermatogenic potential utilizing the procedures and postoperative periods studied. Why certain animals exhibited focal degenerative changes is unclear; perhaps a certain population, yet to be defined, is more sensitive to such procedures, resulting in testicular alterations. It is important that such a population and such changes be defined to predict more accurately the possibility of successful vasovasostomy and reestablishment of fertility.

Animals↗
PubMed1978

The determination of anatomical cross-sections using a radiotherapy simulator.

A system for obtaining anatomical cross-sections for treatment planning using a radiotherapy simulator is described. A fluorescent screen is viewed by a low light level Isocon television camera and the video signal is digitized and stored. Many projections of the phantom are obtained by rotating the simulator gantry. A convolution algorithm has been used to reconstruct chest sections in which skin and lung outlines are visible. The technique could also be used to make corrections to radiotherapy dose distributions where irradiation of lung tissue is involved.

Humans↗
PubMed1977

Vasectomy in rhesus monkeys I. Surgical techniques and gross observations.

Vasectomy and vaso-occlusion techniques were used in 47 male rhesus monkeys to maximize and minimize the amount of sperm allowed to escape from the vas into surrounding tissues for up to seventy-two weeks postoperatively. Body weight changes and blood clinical data indicated that the general health of all the monkeys remained good. Normal seasonal changes in body weights and testicular volumes suggested that there were no disturbances to the endocrine system and that the monkeys remained responsive to seasonal environmental stimuli. Vasectomy appears to cause no short-term deleterious effects in the rhesus monkeys, based on observations made during the seventy-two weeks that these monkeys were study after vasectomy. This conclusion agrees with the findings of other investigators.

Animals↗
PubMed1976

Childhood seizures: a 25-year follow up. Social and medical prognosis.

Over 200 children from a group of 628 were followed up after 25 years. The children were identified as having had at least one seizure. Particular attention was given to the long-term prognosis in relation to medical, social, and educational problems. Although nearly two-thirds of the sample suffered minimal ill-effects, the problems of the remainder were considerable. 10-1% had died. Of the survivors 11-2% were confined to institutions, and 6-6% were invalids at home. Just under a quarter had chronic epilepsy. While overall the educational achievement of the sample was good, there was also a considerable number of educational problems. Continuing epilepsy was associated with greatly reduced educational and occupational achievement compared with the group in remission. The study reveals the considerable cost of epilepsy to the community in both human and material terms. It also reveals why epilepsy is regarded as a frightening illness.

Adolescent↗
PubMed1976

Hypospadias in a male rhesus monkey.

Mid-shaft penile hypospadias was found in an otherwise normal adult male rhesus monkey. Histological examination of the penis supports the conclusion that the condition was congenital and not due to trauma.

Animals↗
PubMed1976

The development of modern endoscopy.

The development of endoscopic techniques and instruments is traced from Bozzini's light transmitter in the early 1800's to the present. Early use of laparoscopes, cystoscopes, hysteroscopes and culdoscopes is described. While the site of use of these instruments differs, certain general aspects are similar. Modern instrumentation permits visualization into almost any body cavity.

Animals↗