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Biomedical subjects

R Alexander

Publications and source records attributed to R Alexander.

144 records · Page 8Linked to original sources
PubMed1979

Myxoid liposarcoma. An ultrastructural study of two cases.

Two cases in which myxoid liposarcomas were examined by use of light and electron microscopy are presented. The relationship of this tumor to the development of normal adipose tissue is discussed. Most of the ultrastructural features were identical to those of developing white adipose tissue. Features not typical of developing white adipose tissue, such as congeries of 60-Angstrom filaments and large masses of glycogen, are also illustrated and discussed.

Adult↗
PubMed1979

The significance of changes in the nasal mucosa in indeterminate, tuberculoid and borderline leprosy.

A study of nasal biopsies from 137 leprosy patients classified on the basis of clinical, microbiological and skin biopsy as Indeterminate, Tuberculoid, Borderline-tuberculoid and Borderline-leproma was undertaken. Changes suggestive of leprosy viz., nerve and smooth muscle inflammation with a few acid fast bacilli in a proportion of the biopsies were seen in all groups of patients examined. This suggests, that even in Indeterminate and Tuberculoid leprosy the disease becomes generalised by the time clinical manifestations appear in skin. Tuberculoid granuloma was seen in two nasal biopsies from Borderline-tuberculoid leprosy patients, one of which was located in the wall of a vein, suggesting the possibility of intravascular dissemination of the disease even in non-lepromatous leprosy. 33 of the patients were children 15 years and below and they also showed changes such as nerve and smooth muscle inflammation but bacilli were seen only in the Borderline group. These findings suggest involvement of the nasal mucosa early in the course of the disease as 70% of the children had the skin lesion for less than one year. The nasal mucosa offers favourable conditions for the growth of the organisms and is readily accessible to infection by droplets, and therefore, it could be one of the primary sites of involvement in leprosy.

Adolescent↗
PubMed1978

Brush biopsy of pyelocalyceal lesions via a percutaneous translumbar approach.

Percutaneous translumbar selective brush biopsy of pyelocalyceal and ureteric lesions is simple, permits ready access to all calyces as well as the ureter and renal pelvis, and facilitates multiple biopsies from different sites. The ability to retrieve tissue fragments from between the bristles allows histological diagnosis in addition to a Papanicolaou smear. Selective washings can be obtained for bacteriologic diagnosis; in many instances, cultures taken directly from the lesion proved to be different from samples taken from the bladder urine or renal pelvis. This method can be expanded to serve a means of establishing a temporary percutaneous nephropyelostomy.

Adult↗
PubMed1978

The participation of ethyl 4-benzyloxybenzoate (BRL 10894) and other aryl-substituted acids in glycerolipid metabolism.

Investigation into the mechanism of action of BRL 10894 (ethyl 4-benzyloxybenzoate), a compound possessing hypolipidemic activity in the rat, disclosed participation in glycerolipid metabolism. In the presence of BRL 10894, an abnormal metabolite was synthesized in vitro using liver slices or rings of small intestine with glycerol, palmitate, or monoolein as substrate, and using adipose tissue with pyruvate as substrate. Esters related chemically to BRL 10894 and other pharmacologically active acids (e.g., ibuprofen) also produced abnormal metabolites in vitro. With BRL 10894 in the diet, a similar metabolite was produced in vivo in rats and accumulated in adipose tissue. Chemical characterization of the material synthesized in vivo showed that the metabolite was a triglyceride in which one fatty acid moiety was substituted by the acid of BRL 10894. Additional proof of this structure was obtained by comparison with reference material synthesized in our laboratories. The study of the initimate involvement of exogenous acids in glycerolipid turnover is of value in the characterization of pharmacologically important acids and may be of use in achieving a greater understanding of certain aspects of lipid metabolism.

Adipose Tissue↗
PubMed1976

Clofazimine in the treatment of dapsone resistant leprosy.

Dapsone resistant patients treated with clofazimine 100 mg daily show a consistent response to treatment. Concern is expressed regarding the prolonged persistence of viable organisms during treatment, with the attendant risk of further resistance developing. The importance of prevention of this problem is discussed.

Clofazimine↗
PubMed1975

Immunoglobulin A glomerulonephritis: a clinicopathologic study.

Renal biopsies from 10 patients staining predominantly for immunoglobulin A are reviewed. Historically, nine of 10 patients were less than 32 years of age; they all presented with either microscopic or gross hematuria. The initial creatinine clearances demonstrated good function in all patients; only one patient experienced a progressive decline in the creatinine clearance. Similarly, proteinuria was mild. The light and electron microscopic findings presented a variable pattern, including a group with changes confined to the mesangium, another group also having glomerular basement membrane changes, and one patient with severe, progressive glomerular sclerosis. Immunogluorescence demonstrated large amounts of IgA predominantly within the mesangium but occasionally involving the peripheral capillary loops. Serum IgA levels were elevated in six of eight patients tested, and two of five patients had elevated nasal IgA concentrations. These data suggest that there is an immunologic entity, IgA glomerulonephritis, characterized by the above clincial findings in association with elevated serum and occasionally nasal IgA levels, but that the pathologic findings are highly variable. Neither the mechanism nor the particular pathogenetic significance of the raised IgA levels is presently known. The similarities of this entity to the reported findings in anaphylactoid purpura are mentioned.

Administration, Intranasal↗
PubMedDate not supplied

Factors in the intestinal absorption of oral cholecystopaques.

Interest in the pharmacokinetics of cholecystopaques initially centered on transport from blood to bile. The data obtained in this effort have been valuable and have shown that the maximal iodine concentration achievable in the bile is quite similar for all of the currently available compounds. This concentration is, of course, dose dependent. the transport of contrast material from the bowel to the blood has been shown to be quite variable. Considerable progress was made in understanding this. The tremendous differences in absorption of iopanoic acid depending upon the pH of the administered solution was an initial revelation. The development of the concept that there is a water layer through which the cholecystopaque must pass before reaching the lipid membrane of the intestinal cell has added clarity to understanding the difference in absorption between water-soluble and water-insoluble cholecystopaques. A complete knowledge of what might enhance or inhibit absorption is not known. There is beginning to be an understanding of how intestinal dose relates to plasma levels. This should lead to an optimal dose-timing scheme for each cholecystopaque. The basic assumption is that the highest iodine concentration in the gallbladder leads to the most accurate cholecystography. If this is true, the gallbladder needs to be offered bile at the maximum concentrations during the period preceding filming. To accomplish this, the appropriate plasma level necessary for maximum excretion is needed. Experimental data suggest that our current clinical methods in regard to dose and dose timing need revision to optimize cholecystography. This revision needs to take place with a careful look at toxicity. Accepting the present premise that oral cholecystography can be improved, perhaps without a significant increase in morbidity, a fundamental question to be asked is: is it worth it?

Animals↗