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Biomedical subjects

J Clark

Publications and source records attributed to J Clark.

At least 505 records · Page 28Linked to original sources
PubMed1976

Functional evaluation of the interposed colon as an esophageal substitute.

Five Rhesus monkeys and four human adults with colonic reconstruction of the esophagus have been studied by manometric, fluoroscopic and reflux tests. Transit through the graft is mainly under the influence of gravity. Infrequent colon contractions can be propulsive, and sequential haustral contractions give the appearance of peristalsis. The diaphragmatic hiatus and esophagocolic anastomosis are the sites of weak barriers to reflux which are readily overcome by abdominal compression and gastric distension. Esophageal peristalsis is necessary to return refluxed material and cricopharyngeus muscle is the final barrier to regurgitation.

Adult↗
PubMed1976

The Edinburgh spleen: source of a validated Kveim-Siltzbach test material.

Although it is true that some Kveim-Siltzbach test suspension may for reasons unknown behave in a totally nonspecific way and so be useless in the confirmation of active sarcoidosis, the experience with the Edinburgh spleen has shown that it is also true that a preparation can be made which acts specifically in the sarcoid context and fulfils all the Siltzbach criteria. The active principle probably resides in the membrane components of sarcoid tissue cells.

Antigens↗
PubMed1976

Spheroplasts of Haemophilus influenzae induced by cell wall-active antibiotics and their effect upon the interpretation of susceptibility tests.

The interpretation of in vitro susceptibility tests of Haemophilus influenzae performed by the agar or broth dilution methods with Levinthal enrichment was found to be markedly influenced by the production of spheroplasts by this species. Using an inoculum of 10(7) organisms/ml, this phenomenon was frequently evident macroscopically as a haziness on agar substrates and in broths containing cell wall-acting agents, such as ampicillin, cephalothin, and penicillin, but was not noted with chloramphenicol. Phase-contrast microscopic examination of the haze from these sources revealed numerous spherical bodies in contrast to the typical cocco-bacillary forms observed in growth controls. With this inoculum size, minimal bactericidal concentrations could not be determined since subculture of 0.1 ml of the hazy broths or the surface haze onto chocolate agar resulted in most instances in the development of a small number of colonies which, upon smear and gram stain, revealed typical Haemophilus morphology. An inoculum of 10(4) organisms/ml abolished the haziness on agar surfaces and in broths and resulted in clear-cut end points. Also, although spherical bodies were still present, they were distinctly less in number as contrasted to tests performed with an inoculum of 10(7) organisms/ml. It is recommended that minimal inhibitory concentration end points in antibiotic susceptibility tests be determined by microscopic, rather than macroscopic, observation of the growth milieu to determine the presence or absence of morphologically typical bacilli which, when observed, is indicative of true in vitro resistance.

Anti-Bacterial Agents↗
PubMed1976

Treatment of benign intracranial hypertension by dehydrating agents with particular reference to the measurement of the blind spot area as a means of recording improvement.

A series of 30 patients (28 females : 2 males) presenting with benign intracranial hypertension is reported. It is shown that the papilloedema may be resolved in as little as six weeks by the use of dehydration therapy. Evidence is presented that this method can restore to normal a visual acuity which is as low as 6/24 or even 6/36. It is concluded that surgery is never required in the management of this condition. It is strongly recommended that serial blind-spot measurements should be used routinely to assess the effectiveness of therapy. Fluorescein angiography has a place in diagnosis among a small proportion of these patients.

Adolescent↗
PubMed1976

Lead and hyperactivity. Behavioral response to chelation: a pilot study.

Lead-chelating medication was used to treat 13 hyperkinetic school children whose blood and urine lead levels were in an elevated but "nontoxic" range. Six children with histories of etiologically relevant perinatal or developmental complications showed relatively little improvement. Seven other children with unremarkable histories, and for whom a lead etiology could thus be entertained, showed marked improvement. The authors conclude that lead may play an important role in the etiology of some cases of hyperactivity; lead-chelating agents may have a major place in the treatment of hyperactivity; and the medical workup of hyperactivity should include lead level measurements and careful consideration of other possible etiological factors.

Child↗
PubMed1976

A longitudinal study of total body potassium in normal breastfed and bottle-fed infants.

In a previous publication we predicted that growth as measured by 40K is best described by comparison of the semilog function of total body potassium (TBK) vs. length with a slope that differs in infants from that of children aged 3-18 years. Data for 84 infants having three or more measurements during the first year of life attest to this hypothesis, with a regression line for TBK and length: loge K, g = -0.265 + 0.04112 length in centimeters.

Adolescent↗
PubMed1975

Lip-service only.

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Attitude of Health Personnel↗
PubMed1975

The effects of premedication drugs on the lower oesophageal high pressure zone and reflux status of rhesus monkeys and man.

Thirty-five human volunteers and eight Rhesus monkeys were studied with standard gastrooesophageal manometric techniqes and their reflux status was evaluated witha pH probe placed in the lower oesophagus. morphine sulphate, pethidine hydrochloride, or idazepam was given intravenously until drowsiness was induced. The manometric and pH studies were repeated. All three drugs decreased the lower oesophageal high pressure zone and increased the probability of relux in both monkeys and man. Thes findings are relevant in the preparation of patients for surgery since gastrooesophageal reflux and pulmonary aspiration may be a problen in the pre-and postoperative phases.

Animals↗
PubMed1975

A longitudinal study of total body potassium in normal children.

Most investigators studying changes in body composition during growth agree to the desirability of having longitudinal data. A group of 110 boys and 126 girls, studied annually for 4-5 years with 880 measurements of total body K in a 2pi liquid scintillation whole body counter, had total body K vs. height and total body K vs. weight data that fit previously described regression lines.

Adolescent↗
PubMed1975

Suicide behavior: community attitudes and beliefs.

A survey of community attitudes and beliefs concerning suicidal behavior is reported, in which women from two suburbs differing widely in their rates of hospital treated self-poisoning and self-injury were interviewed. Sympathetic attitudes to suicidal behavior and to those who engage in it were significantly more prevalent in the low-risk area. Community beliefs regarding lethality, etiology, and ability to distinguish suicide and "attempted suicide" are reported, and the relationship of these beliefs to attitudes is discussed.

Attitude↗
PubMed1975

Treatment of obstructing cancer of the colon and rectum.

A review was made of 128 patients who had obstructing cancer of the colon and rectum. About one-third of the patients had metastatic disease at the time of presentation. Primary resection carried an initial higher mortality rate than staged resection, but at one year and three years, no statistical difference can be found between the two procedures. There are high morbidity and mortality rates with all forms of treatment. A controlled comparative trial of primary and staged resection is recommended in the treatment of obstructing cancer of the colon and rectum.

Adult↗