Search PubMed⌕ Search

Biomedical subjects

M A Jackson

Publications and source records attributed to M A Jackson.

134 records · Page 8Linked to original sources

Diagnosis and treatment of the febrile child following hepatic portoenterostomy.

We report a retrospective analysis of 75 children with hepatic portoenterostomies hospitalized because of fever. Bacterial cholangitis was the most commonly defined cause of fever within 3 months of surgery. Pneumonia and upper respiratory infections were more common 3 months to 2 years following the procedure; however, cholangitis continued to occur during this time period. Twenty percent of hospitalizations were associated with bacteremia or fungemia. Streptococcus pneumoniae was the most common pathogen isolated from the blood. Three children with presumed cholangitis continued to have fever until effective antipseudomonal antibiotic coverage was implemented. The findings in this study lead to the following suggestions: vaccinate all children with pneumococcal vaccine at 2 years of age; a chest radiograph and dental evaluation should be obtained when evaluating the febrile child; empiric treatment for possible cholangitis should include an antipseudomonal penicillin derivative with an aminoglycoside; and if signs of peritonitis are present antibiotic treatment should also include antimicrobials effective against Haemophilus influenzae.

Anti-Bacterial Agents↗

Comparison of piperacillin vs. ticarcillin plus tobramycin in the treatment of acute pulmonary exacerbations of cystic fibrosis.

During a 22-month period 35 children with cystic fibrosis received 52 courses of antibiotic therapy for acute pulmonary exacerbations, including 26 cases of therapy with piperacillin and 26 courses with ticarcillin plus tobramycin. Groups were similar in age (5 vs. 5.4 years), disease severity based on Schwachman scores and presenting symptoms. Pseudomonas aeruginosa was the most common organism isolated in 90% of sputum cultures. Mean minimal inhibitory concentrations for piperacillin, ticarcillin and tobramycin were 8, 64 and 1 microgram/ml, respectively. Piperacillin pharmacokinetic data revealed an average half-life in serum of 36 minutes. Peak serum concentrations averaged 144 micrograms/ml, and after 4 hours serum concentrations continued to exceed the P. aeruginosa 90% minimal inhibitory concentration in 50% of children. The dosage requirement for tobramycin was quite variable, necessitated monitoring of aminoglycoside serum concentrations and in most cases resulted in at least one dosage adjustment. Emergence of resistant bacteria was not seen in 26 courses of piperacillin therapy. Both regimens were effective and well-tolerated. Single agent therapy has the advantage of providing reliable serum concentrations and, in contrast to the standard therapy, does not necessitate monitoring of serum drug concentrations.

Acute Disease↗

Lipid composition of cerebral vessels in American Negroes, Caucasians and Nigerian Africans: a comparative study.

The lipid content of cerebral vessels from American Negroes, Caucasians and Nigerian Africans living in urban areas was chemically quantitated. There are significant differences between the total and free cholesterol content of the vessels among the three population groups. The american Negroes have the greatest amount of cerebral vascular cholesterol compared with American Caucasians and Nigerians. This confirms previous morphological observations that the severity and extent of cerebral atherosclerosis are greater in American Negros than in American Caucasians and aftricans. However, there is no significant difference in the phospholipid content of the cerebral vessels except among the female Negro groups. Chemical quantitation of lipids in vessels may be utilized for assessment of degree of atherosclerosis and may prove to be an acceptable and reliable alternative methodology for epidemiological studies.

Adolescent↗

Trace metal content of cerebral vessels in American Blacks, Caucasians and Nigerian Africans.

Trace metal contents of cerebral vessels in age-matched and sex-matched subjects from three population groups were estimated. The trace metals included calcium, manganese, zinc, magnesium, copper and iron. The American blacks in Washington, D.C., who are ethnologically related to Nigerian Africans, have different patterns of trace metal contents in their cerebral vessels and the observed levels also differed in some respects from Minnesota Caucasians living in a similar environment. The greatest amounts of calcium, zinc, and copper were found in the vessels of American blacks while the greatest amount of magnesium was found in vessels of Minnesota Caucasians. There was no statistically significant difference in the manganese content of the cerebral vessels in three population groups. Nigerian Africans had the least amounts of copper and magnesium but had the highest iron content. A similar high level of iron was observed in the vessels of American blacks. Since it has been shown that American blacks have the most extensive and severe degree of atherosclerosis among the three population groups, it would appear that iron, calcium and manganese in the cerebral vessels may not directly relate to the severity of cerebral atherosclerosis. Relatively high levels of copper and magnesium, which were observed in the cerebral vessels of American blacks and Caucasians, may be of significance in the pathogenesis of cerebral atherosclerosis. The low levels of the trace metals in Nigerians may be protective. The possible role of zinc requires further studies.

Black or African American↗

Changes in serum calcium caused by supplementation of low protein diets with keto-acid analogues in patients with chronic renal failure.

Six patients with stable end stage chronic renal failure have been studied while receiving keto-acid supplements that provided a daily calcium load of 42 +/- 2 mM. None of the patients had intercurrent illness. All patients showed elevated serum calcium concentration levels while on keto-acid supplements, reaching significance on 5 occasions. Reciprocal falls in serum phosphate concentrations were noted in all patients, and this observation was not due to an anabolic effect of the keto-acids. In 3 patients, the rise in serum calcium concentration was associated with marked clinical manifestations that required curtailment of treatment. The risk of hypercalcemia occurs early and certain high risk categories can be identified. Recommendations about the use of calcium salts of alpha-keto-acid analogues are given and it is suggested that a choice should be made available between calcium and sodium salt analogues.

Adult↗

Characterization of prostatic carcinoma among blacks: a preliminary report.

This study was designed to compare United States (Washington, DC) black prostatic carcinoma patients (high-risk group) with Nigerian (Ibadan) black prostatic carcinoma patients (low-risk group). Although the material is meager, preliminary analyses suggest that carcinoma of the prostate is a common disease in both US black men (196 of 1000 autopsies) and in Nigerian black men (67 of 1000 autopsies). The tumor tends to be of a higher histologic grade (less well differentiated) and the carcinomatous foci are more numerous in the Nigerian patients. Fifty-three percent of US patients are in stages I and II when the disease is first discovered. Plasma testosterone, estrone, and estradiol concentrations did not differ significantly between US patients and controls. A statistically significant positive association is indicated between carcinoma of the prostate and the following epidemiologic variables: racial admixture, age of puberty, and age of first coitus. The median age of necropsy cases with carcinoma was 50.0 years in Nigeria and 68.3 years in the US.

Aged↗

Characterization of prostatic carcinoma among blacks: a continuation report.

A clinical and pathologic comparison of carcinoma of the prostate in a high-risk US (Washington, DC) black population and in a low-risk Nigerian (Ibadan) black population is presented. Fifty-two percent of American patients were in clinical stages I and II, whereas only 10% of Nigerian patients were in the same stages. Testosterone and estradiol blood levels were significantly lower (P less than 0.05) in patients with carcinoma of the prostate from Ibadan compared with American black prostate cancer patients from Washington, DC. Age-standardized incidence rates (world standard) for 1000 autopsies for micro (incidental)-carcinoma were approximately equal in American and African black men. The incidence rate of invasive carcinoma was, however, even after adjustment for age, higher in American black men than in African men.

Black or African American↗