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Biomedical subjects

A Solomon

Publications and source records attributed to A Solomon.

At least 307 records · Page 17Linked to original sources
PubMed1978

Duodenal ulcer and working-class mobility in an African population in South Africa.

The number of Africans in Johannesburg presenting with duodenal ulcers has steadily increased over the past 50 years. The characteristics of 105 patients with duodenal ulcer who presented a Baragwanath Hospital were compared with those of matched and unmatched samples of patients without gastrointestinal conditions in the same hospital. Men with duodenal ulcers were found to be significantly better educated than their controls, most had been born in the town, and more of them were employed at higher, though not the highest, educational levels. These data were used to test Susser's proposition that duodenal ulcers are associated with "early urbanisation." Johannesburg blacks with duodenal ulcer did seem to fit the pattern, but the relation between stress and duodenal ulcer remains unclear.

Adolescent↗
PubMed1978

Proteolytic cleavage of human IgG molecules by neutral proteases of polymorphonuclear leukocytes.

The effect on human IgG of the elastase-like (ELP) and chymotrypsin-like (CLP) neutral proteases derived from human polymorphonuclear leukocytes was studied. By incubating ELP with monoclonal IgG proteins, two immunochemically and electrophoretically distinct components were formed which were similar, but not identical, to the Fc and Fab fragments produced by papain digestion. When an IgG protein was incubated under similar conditions with CLP enzyme, no proteolysis was observed. IgG proteins differed in their susceptibility to proteolysis by ELP. These differences were related to the subclasses IgG1-IgG4. The IgG1 and IgG3 proteins were readily cleaved by ELP, but the IgG2 and IgG4 proteins were more resistant. Although free light chains differ in susceptibility to proteolysis by ELP, our studies showed that neither the type (kappa or lambda) nor the subgroup of light chain affected the susceptibility of complete IgG molecules to cleavage by this enzyme.

Animals↗
PubMed1978

Bence Jones proteins and light chains of immunoglobulins. XV. Effect of corticosteroids on synthesis and excretion of Bence Jones protein.

The effect of corticosteroids and cytotoxic chemotherapeutic agents on the excretion of Bence Jones protein was determined for periods of 1 - 62 mo in 29 patients with multiple myeloma and Bence Jones proteinuria. The amount of protein present in 24-h urine specimens collected before treatment and at frequent intervals during monthly treatment cycles was determined. Striking variations occurred in the amount of Bence Jones protein excretion; these changes were especially evident when 75 mg of prednisone were given daily for 7 days as part of a monthly chemotherapeutic regimen. Within the 7-day period seven patients showed essentially no decrease (<25%), whereas 13 and 9 patients had a moderate decrease (25-75%) or a marked decrease (>75%), respectively, in Bence Jones proteinuria as compared to pre-treatment values. The decrease in excretion of Bence Jones protein during this period was attributed mainly to corticosteroid therapy because of the transient nature of the response in most patients and the lack of such response in three patients when the hormone was omitted. Biosynthetic studies were performed to determine in vitro the effect of corticosteroids on Bence Jones protein synthesis. Plasma cells obtained from the bone marrow of 13 patients were incubated in a growth medium containing (14)C-labeled lysine and isoleucine and prednisone in concentrations up to 240 mug/ml, and the amount of Bence Jones protein synthesized was determined immunochemically. No differences in viability were apparent between untreated and prednisone-treated cells. The type of response exhibited by an individual patient in the percent decrease of Bence Jones protein excreted after 7 days of prednisone treatment was comparable to the percent decrease in newly-synthesized Bence Jones protein secreted by tumor cells when cultured in the presence of prednisone at a concentration of 120 mug/ml. The marked differences in the capacity of corticosteroids to affect Bence Jones protein synthesis appear to reflect a biochemical heterogeneity among plasma cell neoplasms.

Adult↗
PubMed1977

The giant duodenal ulcer syndrome.

Thirteen patients with giant duodenal ulcer manifested with a distinct clinical syndrome. The condition has a characteristic clinical, radiological and endoscopic presentation. It is associated with a high mortality when treated medically, and constitutes a definite indication for surgery. The giant duodenal ulcer forms a high proportion of duodenal ulcers in a recently urbanized Black community, and may be one of the dramatic and significant presentations of this disease in the developing countries.

Adolescent↗
PubMed1977

Pyriform fossa carcinoma in South African Negro patients.

Seven patients with pyriform fossa carcinoma who presented at Baragwanath Hospital during the period 1973-1976 are discussed. The value of positive contrast studies with special reference to laryngography is emphasized and the results are reviewed.

Black or African American↗
PubMed1977

Pneumoconiosis in non-mining industries on the Witwatersrand.

Two hundred and eighty-seven patients referred to the National Research Institute for Occupational Diseases with suspected pneumoconiosis are recorded. The patients are classified according to the type of dust to which they were exposed, and by occupation or industry. Radiological evidence of pneumoconiosis according to ILO/UICC classification is the only acceptable basis for compensation at present, and the number of patients so diagnosed is also given. None of these figures show the true distribution and incidence of pneumoconiosis as a form of occupational disease on the Witwatersrand. They only indicate the presence of pneumoconiosis not associated with mining and reflect a wide range of occupations.

Asbestosis↗
PubMed1977

The use of rare-earth radionuclides and other bone-seekers in the evaluation of bone lesions in patients with multiple myeloma or solitary plasmacytoma.

Twenty-four patients with multiple myeloma and 4 with solitary plasmacytoma had total-body scans after intravenous injection of 67Ga-citrate alone (17 patients) or combined with other agents (11 patients). The latter included 99mTc-diphosphonate (99mTc-DP), 99mTc-polyphosphate (99mTc-PP), or 99mTc-sulfur colloid (99mTc-SC) given alone or combined with 171Er, 157Dy, or 167Tm as citrate. In some patients more than one agent was compared to 67Ga and radiographic bone surveys. In general, localization of the rare-earth "bone-seekers" was poor except for 157Dy, which compared well with 99mTc-PP and 99mTc-DP; 157Dy was also helpful in studies of the abdomen and pelvis because of its failure to concentrate in the gastrointestinal tract. No toxic or nonspecific effects were noted.

Dysprosium↗
PubMed1977

Immunological studies of patients with asbestosis. II, Studies of circulating lymphoid cell numbers and humoral immunity.

As part of an overall assessment of immunological function, several aspects of humorial immunity and circulating lymphocyte subpopulations were evaluated in a group of twenty-six patients with radiographic evidence of parenchylmal asbestosis. Statistical comparisons were made between the patient group and a comparable group of forty-five controls. Both the percentages and absolute numbers of circulating T lymphocytes were significantly reduced in the patient group compared with controls. Significant elevations of salivary secretory IgA and of serum IgA, IgG, IgM and IgE were noted amongst the patients compared with the controls. Non-organ-specific autoantibodies and cold-reactive lymphocytotoxins were present in high frequency in the patients' sera. Neoplasms were detected in four of the patients. The possible significance of these findings is discussed.

Antilymphocyte Serum↗
PubMed1977

Phase II study of oral methyl-CCNU and prednisone in previously treated alkylating agent-resistant multiple myeloma.

Thirteen patients with multiple myeloma (MM) who either failed to respond to or who were relapsing from standard agents and who received four or more courses of methyl-CCNU + prednisone (adequate drug trial) are reported in this paper. Methyl-CCNU was given orally before breakfast at 6-week intervals at a starting dose of 50 mg/m2 with the intention of increasing the dose to 100, 150, and 200 mg/m2 with each subsequent course. The dose of prednisone was 75 mg/day x 7 with each course. The response rate was 46% (six of 13 patients). No patient had better than a fair response. Drug toxicity, severe enough to prevent further dose escalation, was observed in every case. Prior BCNU therapy or the lack of response to previous alkylating agents did not prevent a response to methyl-CCNU + prednisone. The response rate of methyl-CCNU + prednisone in MM is comparable to the results achieved with other agents in similar groups of patients.

Administration, Oral↗
PubMed1977

Emergence of diverticular disease in the urban South African black.

A low residue, fiber-deficient diet has been postulated as the cause of diverticular disease--the commonest affliction of the colon in the Western nations. This condition is virtually unknown in Africans (blacks) who live south of the Sahara, and who have not changed their traditional high residue diet. This paper presents 16 Africans with diverticular disease. A disturbing feature is that 5 of the patients are young, being in their fourth decade, and only 4 are over the age of 60. Their dietary history confirms the hypothesis as to the etiology, and also shows that the urbanization of the South African black has been accompanied by the emergence of diverticular disease, a condition higherto virtually nonexistent in this population.

Adult↗
PubMed1977

Immunological studies of patients with asbestosis. I. Studies of cell-mediated immunity.

A variety of cancers have been documented in patients exposed to asbestos dust. Since a deranged immune system may play a rôle in cancer development, the general level of immunocompetence was studied in a group of twenty-six patients with radiographically defined asbestosis, who might be at risk of developing asbestos-related neoplasms. Statistical comparisons were made with a comparable control group. A disproportionate number of the patients displayed cutaneous energy to certain recall antigens and to 2,4-dinitrochlorobenzene. In vitro studies of cellular immunity, as evaluated by phytohaemagglutinin-induced proliferative and cytotoxicity assays, showed significantly lower values amongst the patient group. Serum inhibitors of mitogen-induced lymphocyte transformation were also detected in several of the patients. The possible significance of these findings is discussed.

Adult↗
PubMed1976

Luminescence studies on Bence-Jones proteins and light chains of immunoglobulins and their subunits.

To provide information on the tertiary structure of the antibody molecule we have investigated the luminescent properties of the light polypeptide chain of human immunoglobulins. The fluorescence and phosphorescence yields, spectra, lifetimes, and anisotropies of a large number of homogeneous light chains, i.e., Bence-Jones proteins and light chains derived from myeloma proteins, were measured. No two proteins gave identical tyrosyl or tryptophyl fluorescence spectra in comparative studies on over 75 proteins belonging to the four basic subgroups of kappa chains and of lambda chains. Spectral differences were apparent even among proteins exhibiting more than 85% amino acid sequence identity. The fluorescence yields of tyrosine and tryptophan vaired 10- and 100-fold, respectively; the Stokes' shift of tryptophan ranged from 328 to 365 nm, but that for tyrosine was apparently invariant (305-307nm). Emission as well as excitation spectra showed tyrosyl and tryptophyl redidues interact minimally or not at all. Fluorescence lifetimes of the tyrosyl and tryptophyl contributions were measured spearately, and the apparent natural lifetimes were calculated. Proteins could be grouped in accordance with similarities in fluorescence lifetimes and fluorescence yields; there was no evident relationship between these groupings and the light chain type (kappa or lambda), amino acid sequence, or tryptophan content. Also apparent were individual differences among kappa light chains and among lambda light chains in respect to their tyrosyl and trptophyl phosphorescence spectra and phosphorescence lifetimes. Certain proteins showed an atypical, short-lived tryptophan phosphorescence decay time. Such variance in the luminescent behavior of the tryptophyl residue(s) indicates a conformational interaction between the V and C domains of light chains. Selective proteolytic cleavage of the light chain into VL and CL fragments permitted the comparison to be made of the luminescent properties of the V and C domains with those of the whole protein. The V domain and intact protein have luminescent features in common, whereas the C domain possesses features distinctive from that of the native protein. Data derived from fluorescence anisotropy spectral studies of intact light chains and their VL-related fragments indicate that energy transfer between tryptophyl residues occurs in the C domain. The results of emission spectroscopic measurements performed at 220 and at 77 K indicate that the observed phophorescence of light chains is mainly from a tryptophyl residue contiguous to a disulfide link. The potential for interdomain interaction in light chains is evidenced by the finding that the orientation of the tryptophyl residue(s) in the V domain can influence the tryptophyl-disulfide ling interactions in the C domain; this interaction may account further for the extensive structural diversity of antibody molecules.

Bence Jones Protein↗
PubMed1976

Lipomata of the central nervous system.

The radiological features and some clinical aspects of lipomata of the central nervous system are discussed, with examples of the different sites of involvement.

Brain Neoplasms↗