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Biomedical subjects

M A Rodriguez

Publications and source records attributed to M A Rodriguez.

At least 163 records · Page 9Linked to original sources
PubMed1984

Immunoglobulin production by peripheral blood mononuclear cells in patients with alcoholic liver disease.

Baseline unstimulated IgG and IgM production by peripheral blood mononuclear cells from 16 patients with alcoholic liver disease (ALD) was slightly higher than that of normal controls. No significant differences were noted when IgG and IgM production were studied using 7 day cultures of B cells from 25 ALD and 22 normal controls; pokeweed mitogen stimulated IgG and IgM production also showed no difference between 26 ALD and 22 normal controls. B cells from patients with ALD showed marked hyporesponsiveness particularly in IgG production in response to T cell derived helper factors. Pre-incubation of B cells with three different concentrations of alpha-interferon followed by addition of helper factor and 7 day culture showed markedly diminished IgG production in ALD patients as compared with controls. When normal peripheral blood mononuclear cells were pre-incubated with ALD plasmas for 2 h, significant increments in both IgG and IgM production were recorded in comparison to pre-incubations with normal plasmas. The ambient state of B cell activation is considerably different in ALD from normal subjects.

Adult↗
PubMed1983

Administration of nonsteroidal anti-inflammatory agents in patients with rheumatoid arthritis. Effects on indexes of cellular immune status and serum rheumatoid factor levels.

We have previously reported that nonsteroidal anti-inflammatory agents (NSAIAs) stimulate cellular immune responses and inhibit production of IgM rheumatoid factor in cultures of lymphocytes from patients with rheumatoid arthritis. We had 20 patients with rheumatoid arthritis stop taking NSAIAs for two weeks and then take piroxicam, a new NSAIA, for an additional ten weeks to assess the in vivo effects of NSAIAs on cellular immunity and rheumatoid factor levels. In each case, serum rheumatoid factor levels rose and phytohemagglutinin response fell when placebo was substituted for NSAIAs. Piroxicam administration was associated with a fall in rheumatoid factor levels to approximately 62% of the baseline level and with an increase in phytohemagglutinin response. The action of NSAIAs in rheumatoid arthritis may be mediated to a degree by partial correction of the disordered immunoregulation in this disease.

Adult↗
PubMed1983

Human alpha-interferon enhances in vitro IgM rheumatoid factor synthesis by lymphocytes from normal subjects and rheumatoid arthritis patients.

Alpha-interferon (alpha-IFN) was added to pokeweed mitogen (PWM) or Epstein-Barr virus stimulated human peripheral blood mononuclear cell cultures from normal subjects or patients with rheumatoid arthritis (RA). Alpha-IFN enhanced in vitro production of PWM induced IgG and IgM, and significantly enhanced PWM induced IgM rheumatoid factor (IgM-RF) production by lymphocytes both from normal subjects and RA patients. Enhancement was recorded whether cells were preincubated with alpha-IFN for 16 hours or with alpha-IFN present throughout the culture period. Alpha-IFN did not enhance IgM-RF production in the absence of PWM or T cells. Enhancement of IgM-RF production was not seen in Epstein-Barr virus stimulated cultures.

Adult↗
PubMed1983

Characterization of the suppressor activity in lymphocytes from patients with common variable hypogammaglobulinemia: evidence for an associated primary B-cell defect.

The pathogenetic mechanisms responsible for the impaired immunoglobulin production in common variable hypogammaglobulinemia (CVH) are diverse with abnormalities in both B cells and immunoregulatory T cells. Production of IgG, IgM, and IgM-rheumatoid factor (IgM-RF) was measured in pokeweed mitogen (PWM) or Epstein-Barr virus (EBV)-stimulated cultures using various combinations of CVH, cord blood mononuclear cells (CBMC), and normal adult control B and T cells. The following results were obtained. First, the proportion of OKT3+ and OKT8+ cells were increased in CVH patients. Second, the T cells from four CVH patients and CBMC suppressed PWM-induced IgG, IgM, and IgM-RF production by normal B cells. Furthermore, major suppressor activity was found in the OKT8+ T-cell subpopulations in CBMC and three out of four CVH patients. There was no significant difference in relative suppression by OKT8+ cells from normal adults, CVH patients, or CBMC. However, in one CVH patient suppressor T cells were found in both OKT4+ as well as OKT8+ fractions. In the CVH patient with OKT4+ suppressor cells, X irradiation (1250 rads) abrogated suppressor activity and restored helper activity in the OKT4+ T-cell fraction. Irradiation of normal OKT4+ cells did not increase helper activity. When non-E-rosetting cells from normal subjects, CVH, and CBMC were stimulated with EBV it was observed that normal adult B cells could be induced to secrete IgG, IgM, and Ig-RF whereas CVH and CBMC could only produce IgM and IgM-RF but not IgG. The present study demonstrates for the first time that a radiosensitive OKT4+ suppressor cell is present in some CVH patients.

Agammaglobulinemia↗
PubMed1983

Studies on the relationship between HLA DR4 and in vitro IgM rheumatoid factor production.

The relationship between the presence of the DR4 antigen and other HLA antigens and in vitro production of IgM-rheumatoid factor by lymphocytes from a group of healthy young subjects was examined. Pokeweed and Epstein--Barr virus-stimulated lymphocyte cultures were examined for the production of rheumatoid factor and immunoglobulins. No significant correlation was found between the presence of the DR4 antigen and in vitro production of IgM rheumatoid factor. The presence of the B18 antigen seemed to identify a population of nonresponders when stimulated with PWM.

Adult↗
PubMed1983

Influence of dietary fiber on fecal excretion of volatile fatty acids by human adults.

The ability of dietary fibers to influence the excretion of volatile fatty acids (VFA) in feces was evaluated in five healthy men. Throughout the 63-day study subjects were confined to a metabolic unit and fed semipurified diets. Each diet was consumed for 9 days. Feces were homogenized, and aliquots were analyzed for VFA by a steam distillation procedure followed by gas-liquid chromatography. Individuals showed wide variability in the extent to which they excreted VFA, and there is evidence of some subject-diet interaction. Acetate, propionate and butyrate were generally present in the ratios of 35:25:20, but the proportion of acetate was increased when xylan and corn bran were consumed. The excretion of VFA during the last 3 days of each metabolic period increased with diet as follows: xylan, fiber free, cellulose, pectin and corn bran. Corn bran caused a significant increase in total VFA excretion over the fiber-free diet. Concentration of VFA in excreted feces (or expressed as percentage of fecal solids) increased by diet in the following order: cellulose, xylan, corn bran, pectin and fiber free. Thus, the concentration of VFA in feces showed no relationship to the total quantity of VFA excreted.

Adult↗
PubMed1983

alpha-Interferon increases immunoglobulin production in cultured human mononuclear leukocytes.

Interferons (IFN) are known to modulate immune responses in either an inhibitory or a stimulating manner. The present study was initiated to investigate the mechanisms by which alpha-IFN modulates Ig production of human peripheral blood mononuclear cells (PBMC). IgG and IgM production was measured in pokeweed mitogen- (PWM) stimulated 7-day cultures of PBMC. Significant enhancement of IgM and IgG production was observed when alpha-IFN was added. Overnight preincubation followed by washing also produced significant enhancement. The effect of alpha-IFN was not obtained in the absence of PWM or T cells. The effect of alpha-IFN on cultures of B and T cells was not altered by irradiation of T cells (2000 rad). alpha-IFN was not shown to enhance the production of helper factor but did increase the responsiveness of B cells to helper factor if the B cells were preincubated with alpha-IFN. Finally, alpha-IFN did not increase the Ig production of PBMC induced by Epstein Barr virus (EBV), and the outgrowth of EBV-infected PBMC was not affected. Overall, these results show for the first time that the effect of alpha-IFN on PBMC is due to an enhanced responsiveness of B cells to helper factors produced by radioresistant T cells.

Adult↗
PubMed1982

Non-steroidal anti-inflammatory agent inhibit the synthesis of IgM rheumatoid factor in vitro.

The effects of three non-steroidal anti-inflammatory agents, indomethacin, carprofen, and piroxicam, on in-vitro IgM rheumatoid-factor (IgM-RF) production by peripheral-blood mononuclear cells were studied in lymphocytes isolated from the peripheral (age 20-40 years) and elderly (age 70-80 years) volunteers selected for their known in-vitro IgM-RF production. All three drugs in therapeutic concentrations inhibited IgM-RF production approximately 50%. Addition of low doses of prostaglandin E2 (PGE2) (30 nmol/l) to the cultures containing indomethacin restored the IgM-RF production to the original levels. Neither indomethacin nor PGE2 had any effect on IgM-RF production if the T cells were irradiated before culture. Endogenous PGE2 seems to stimulate IgM-RF production through an effect on a radiosensitive T-cell population. Non-steroidal anti-inflammatory agents block PGE2 production and therefore reduce IgM-RF production in vitro. These results suggest a new mechanism for the beneficial effect of prostaglandin synthetase inhibitors in the treatment of rheumatoid arthritis.

Adult↗
PubMed1981

Characterization of the suppressor cell activity in human cord blood lymphocytes.

Newborn mononuclear cells are known to have increased suppressor activity when compared with adult cells. However, the precise phenotypic description of the suppressor cell subpopulation has not yet been reported. This study was designed to examine the surface markers on human cord blood cells as defined by monoclonal antibodies and to characterize cord blood mononuclear cells that suppress in vitro pokeweed mitogen-driven immunoglobulin production. The pattern of fluorescence with the 9,6-monoclonal antibody suggested either a decreased density or a partial blocking of E-receptors on cord blood lymphocytes. Otherwise, human cord and adult cells had similar proportions of T cell subpopulations. Different subsets of newborn cells isolated by a monoclonal antibody rosetting technique were tested for suppressor activity. Cord blood lymphocytes recognized by the OKT8 monoclonal antibody constituted the major functional suppressor cell subpopulation. These cells were present in both E-rosetting and non-E-rosetting populations. Removal of OKT8+ mononuclear cord blood cells abrogated most of the suppressor activity. Thus the major suppressor cell present in cord blood is an OKT8 positive lymphocyte.

Adult↗
PubMed1981

Racemose cysticercus in human brain. A case report.

A case of invasion of the brain of a 48-year-old man, a native of Louisiana, by a larval tapeworm is described. Inasmuch as there were no scolices or rostellar hooks present the parasite was identified as a racemose cysticercus which could be either a sterile coenurus of Taenia multiceps (= Multiceps multiceps), Taenia serialis (= Multiceps serialis), or an aberrant cysticercus of Taenia solium or of a different species of Taenia. Most of the parasite was removed surgically with a preoperative diagnosis of brain tumor. After operation the patient improved, and 32 months after onset of his illness he was working and showed no evidence of a recurrence.

Brain↗
PubMed1979

Hemangioma of the ovary in an 81-year-old woman.

We have reported a case of cavernous hemangioma of the ovary in an 81-year-old woman with uterine prolapse and without ascites. Review of the literature reveals that this is the oldest patient reported. The size of the lesion is considered large at 5 cm in diameter. No associated disease or other lesions were present. The lesion was an incidental finding with no complications.

Aged↗
PubMed1978

Mucinous carcinoid and endometriosis in an inside-out appendix.

This is the first report of the simultaneous occurrence of mucinous carcinoid and endometriosis in an inside-out appendix. The literature concerning carcinoids, endometriosis and intussusception of the appendix is reviewed. The mucinous, or goblet cell carcinoid was positive for mucin, argentaffin and argyrophil stains. Paneth cells were present. Two and one-half years with no tumor recurrence suggest good prognosis as previously reported.

Adult↗