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Biomedical subjects

G Ramirez

Publications and source records attributed to G Ramirez.

At least 109 records · Page 6Linked to original sources
PubMed1986

The effect of furosemide during normoxemia and hypoxemia.

The effect of furosemide infusion was studied in 6 normal subjects and 6 patients with severe COPD and right ventricular failure during normoxemia and hypoxemia. In normal subjects, hypoxemia alone caused an insignificant (p less than 0.15) fall in plasma aldosterone concentrations (PAC). Intravenously administered furosemide resulted in significant (p less than 0.05) increases in PAC during both normoxemia and hypoxemia. After furosemide treatment mean arterial pressure (MAP) was significantly lower and arginine vasopressin (AVP) was significantly higher (p less than 0.05) with hypoxemia than with normoxemia. These changes in MAP and AVP were strongly correlated (r = -0.84). Urinary losses of water and sodium were similar after furosemide treatment with hypoxemia and normoxemia. In patients with right ventricular failure, neither changes in oxygenation nor furosemide infusion affected the markedly elevated baseline PRA and PAC levels. Arginine vasopressin levels were significantly higher with hypoxemia than with normoxemia, but urinary losses of water and salt did not differ between the 2 study days. We conclude that hypoxemia does not affect the PAC increase or urinary volume and sodium response to furosemide.

Adult↗
PubMed1985

Bromocriptine and the hypothalamic hypophyseal function in patients with chronic renal failure on chronic hemodialysis.

Ten patients with chronic renal failure on chronic hemodialysis had the following tests to evaluate the integrity of the hypothalamic hypophyseal axis: (A) glucose tolerance test, (B) thyrotropin releasing hormone stimulation test, (C) clonidine stimulation test, (D) insulin induced hypoglycemia, and (E) LH/RH stimulation test. The majority of those tests were abnormal and prolactin values were found to be moderately elevated in all the patients. Bromocriptine (1.25 mg twice a day) was given to all the patients for 1 month and then, while on bromocriptine, the tests were repeated. Although there is a decrement in the concentration of serum prolactin level, none of the hypothalamic hypophyseal abnormalities were corrected. However, five of the ten patients reported an improvement of their impotence with bromocriptine. The patients who responded had high levels of FSH and LH with levels of testosterone above 1 mg/mL. The nonresponders had low FSH and LH levels and very low testosterone levels. Therefore, bromocriptine, although possibly beneficial in some dialysis patients, is not a drug that can normalize abnormal functioning of hormones in the dialysis population.

Adult↗
PubMed1985

Effect of hypoxemia on the renin-angiotensin-aldosterone system in humans.

Hypoxemia was induced in five subjects older than 40 (group 1) and five younger than 35 yr (group 2) on normal and low-salt diets by having the subjects breathe hypoxic gas. The fractional inspired O2 of the hypoxic gas was regulated so that group 1 hemoglobin saturations fell to 90% for 1 h. Group 2 subjects had desaturation to 90% for 1 h followed by desaturation to 80% for a 2nd h. Plasma renin activity (PRA), angiotensin-converting enzyme activity (ACE), and plasma cortisol levels did not change during hypoxemia. Plasma aldosterone levels fell in both groups during the 1st h of hypoxemia. Decreases were greatest during salt restriction and were significant (P less than 0.01) for the combined groups. Plasma aldosterone levels plateaued during the 2nd h of more severe hypoxemia in group 2. Hepatic blood flow, measured by indocyanine green clearance, and the adrenal response to exogenous adrenocorticotropic hormone, measured by changes in plasma cortisol and aldosterone, were not changed by hypoxemia in group 2 subjects. These results indicate that plasma aldosterone falls during hypoxemia despite unchanged PRA, ACE, hepatic blood flow, and adrenal function.

Adrenal Glands↗
PubMed1985

Effect of normoxemic and hypoxemic exercise on renin and aldosterone.

Five subjects (group 1) performed progressive treadmill exercise on 2 separate days, once while breathing room air (normoxemic) and the other time while breathing gas with a fractional inspired O2 of 17% (hypoxemic). Five other subjects (group 2) performed two progressive treadmill exercise tests on each of 2 separate days in a crossover design. On 1 day normoxemic exercise was first, followed by hypoxemic exercise, and on the other day the pattern was reversed. Plasma renin activity (PRA) increased to a similar extent with hypoxemic exercise as with normoxemic exercise. Plasma aldosterone concentrations (PAC) rose to a significantly higher level during normoxemic exercise than with hypoxemic exercise. Comparing changes in PRA to PAC with progressive exercise revealed dissociation of PAC from PRA during hypoxemic exercise. The PAC response remained depressed when normoxemic exercise followed hypoxemic exercise. These results indicate that hypoxemia interferes with PRA-mediated aldosterone secretions. The mechanism of this inhibition is unclear.

Adolescent↗
PubMed1985

Ankylosing spondylitis and glomerulonephritis. Study of a case.

Ankylosing spondylitis is a seronegative spondyloartropathy associated with IgA glomerulonephritis. We described a case not associated with IgA immunoglobulin deposition in the glomerulus, but with C3 complement deposition. At the same time circulating immune complexed of the IgG type were found. The possible association of glomerulonephritis and seronegative spondyloartropathies are discussed.

Complement C3↗
PubMed1985

Lymphocytotoxic activity of monoclonal immunoglobulins in plasmalymphocytic diseases.

95 of 1,019 (9.3%) sera with monoclonal immunoglobulins (MIg) were found to have cold-reacting lymphocytotoxins (LCT). There was no difference in the prevalence of LCT in multiple myeloma, macroglobulinemia, cancer, lymphoma or benign monoclonal gammopathy. Prevalence of LCT was similar in various classes and types of MIg with the exception of the IgG/lambda group in which LCT were more common than in IgG/K (p = 0.013). IgMs had the most potent whereas IgAs had the weakest LCT activity. MIg were purified from 61 LCT-positive sera. 25 pure MIg (41%) had LCT activity. In the rest, LCT activity resided in other fractions. 64 sera with LCT were tested against B and T cells; 56% were equally cytotoxic to B and T cells, 39% killed more B cells and 5% killed more T cells. 18 purified lymphocytotoxic MIg killed both B and T cells. When serial dilutions of sera, and of purified MIg were tested, in all but one instance the reactivity with the T cells weakened more than that with the B cells. Lymphocytotoxins absorbed to and eluted from the peripheral blood lymphocytes or separately from B or from T cells retained LCT activity against B and T lymphocytes. It may be concluded that about one tenth of sera with M components have lymphocytotoxic activity and that in about 40% of these positive sera, this activity is related to the monoclonal immunoglobulins. LCT react with both B and T cells. Antilymphocyte activity of MIgs may play a role in immunoregulatory abnormalities in plasmalymphocytic diseases.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1985

The skin in IgA nephropathies.

Fifteen men (average age 54.6 +/- 14.6 years) with IgA-associated glomerulonephritis underwent concomitant skin and renal biopsies to clarify any potential diagnostic relationships. Both types of tissues were studied by standard light, immunofluorescent, and electron microscopic techniques. The glomeruli of all the patients studied showed renal mesangial IgA deposits. All corresponding skin biopsy specimens showed no IgA deposition in the cutaneous blood vessels. The negative association suggests that examination of the skin biopsy specimen alone is not reliable in establishing the diagnosis of primary IgA nephritis. In view of the known skin involvement in Henoch-Schönlein nephropathy, we propose that skin biopsy specimens be examined routinely when renal biopsy specimens demonstrate IgA deposits, to differentiate primary IgA nephropathy from a forme fruste of Henoch-Schönlein purpura.

Adult↗
PubMed1984

Phase II trial of PCNU in advanced colorectal carcinoma. An Eastern Cooperative Oncology Group pilot study.

PCNU, a chloroethylnitrosourea with high alkylating activity, low carbamoylating activity, optimal octanol: water partition coefficient, and broad activity in animal systems was administered to 30 evaluable patients with measurable advanced colorectal carcinoma by brief intravenous infusions every 6 weeks. The initial dose was 75 or 100 mg/m2, with escalation or reduction for toxicity, and a total of 64 evaluable courses were given. Half of the patient population had received no prior chemotherapy. Two objective partial responses occurred. The response rate was 6.7% with a 95% confidence interval of 0.8-22.1%. Thrombocytopenia was dose-limited and leukopenia was relatively mild. Gastrointestinal toxicity was less severe than expected for clinically available nitrosoureas. In colorectal carcinoma, PCNU has limited clinical activity that does not appear to be superior to that of other nitrosoureas.

Adenocarcinoma↗
PubMed1984

Goldblatt phenomenon in a single kidney: the importance of subselective renal vein renins.

We have reported a case of renovascular hypertension in a patient with a solitary kidney with a significant stenosis of one of three separate renal arteries. Elevated renins were detected only with segmental sampling. We believe cases of renovascular hypertension may be overlooked on angiography and consequently, without segmental renin samples, lateralizing renin elevation may not be discovered.

Humans↗
PubMed1984

Cardiac arrhythmias on hemodialysis in chronic renal failure patients.

A high incidence (40%) of cardiac arrhythmias was found in patients while on dialysis. This incidence was significantly higher than on nondialysis days. A comparison study of patients with significant cardiac arrhythmia and patients with cardiac arrhythmia was made. There was no difference in the echocardiogram, total body potassium, plasma renin activity, aldosterone, catecholamines, serum sodium, potassium and calcium between the two groups. Significant alkalinization occurred in all patients at the end of dialysis. Blood levels of total PTH and C peptide were higher in the arrhythmic patients versus the nonarrhythmic patients. No explanation was found as to why patients developed arrhythmias or what differentiated the two groups.

Adult↗
PubMed1984

Aggressive combined modality therapy for advanced local-regional breast carcinoma.

Thirty-two women with advanced local regional breast carcinoma, including nine patients with histologically diagnosed inflammatory cancer, were entered on a prospective pilot study. They were treated aggressively with initial surgery, two courses of induction chemotherapy with cyclophosphamide, methotrexate, 5-fluorouracil, +/- prednisone, +/- tamoxifen (CMF [P] [T]), local-regional radiotherapy, and then maintenance chemotherapy with CMF(P) (T) alternating with doxorubicin, vincristine, +/- tamoxifen (AV[T]). The patients have been followed for 19-70 months from the time of mastectomy and their actuarial three-year survival is 65% with a median survival that has not yet been reached. Median disease-free survival (time to progression) is currently 29.5 months. Women whose gross disease could not be totally resected surgically had shorter disease-free survivals than those rendered surgically free of disease (p = 0.01). Clinically evident cardiotoxicity was seen in 25% of the patients and was felt to be primarily due to the combination of doxorubicin and radiation therapy. It was significantly more common (Plt less than 0.05) in patients with left chest irradiation (seven of 18 women) as opposed to those with right-sided irradiation (one of 14).

Adult↗
PubMed1984

Cobalt therapy prophylaxis of recurrence of T1 bladder cancer.

Eighteen patients with T1 transitional cell carcinoma of the urinary bladder were submitted to transurethral resection of the tumor, followed by Cobalt therapy (5,500 rads to the pelvis and 6,500 rads to the bladder in six weeks). The recurrence rate at three years follow-up was 33% (6/18). Recurrence of transitional cell carcinoma of the urinary bladder is a well known condition in stage O and A, even when low grade is present. Recurrence rates at one year as high as 84% (Loening et al., 1983) are reported in the current literature. In recent years many studies have been performed which were oriented to the use of intravesical chemotherapy in order to reduce the recurrence rate (Adolphs and Bastian, 1983; Huland, 1983; Loening et al., 1983; National Bladder Cancer Collaborative Group A, 1977; Rodriguez and Caserta, 1983; Zincke et al., 1983) of this tumor. We started a protocol on treatment of the transitional cell carcinoma of the urinary bladder in 1963. The protocol calls for transurethral resection of the tumor followed by Cobalt therapy. This is an interim report on stage T1 (stage A) with such a treatment.

Adult↗
PubMed1984

Hemolytic uremic syndrome after Campylobacter-induced diarrhea in an adult.

Campylobacter fetus subspecies jejuni is a recognized pathogen of the gastrointestinal (GI) tract resulting in a spectrum of illness from mild gastroenteritis to severe colitis with bloody diarrhea. Campylobacter is also being recognized as capable of producing systemic illness. Furthermore, antibody response, hypocomplementemia, and bacteremia with enterotoxic organisms have been described. Many of the clinical features, both local (le, in the GI tract) and systemic, parallel those of Shigella. Since the hemolytic uremic syndrome (HUS) may be produced by the effect of endotoxins or the immunocomplex on vascular endothelium in susceptible patients, it is expected that this syndrome may follow Campylobacter enteritis as it does Shigella enteritis. We, therefore, believe Campylobacter jejuni enteritis should be considered as one of the causative agents capable of inducing the HUS.

Age Factors↗
PubMed1983

Acute interstitial nephritis associated with chronic active hepatitis.

Chronic active hepatitis has been associated with renal abnormalities and immune-mediated glomerulonephritis or vasculitis. We report a case of acute reversible renal failure due to renal interstitial infiltration by lymphocytes, plasma cells, and neutrophils. The acute renal failure responded to the administration of prednisone. It is possible that interstitial nephritis is commonly associated with acute and chronic hepatitis.

Acute Disease↗
PubMed1982

Immunopathology of rheumatic pericarditis.

Immunologic mechanisms have been implicated in the endocarditis, myocarditis, and arthritis of acute rheumatic fever. However, pericarditis, a major manifestation of acute rheumatic fever with a clinical incidence of 5-10%, has not been studied. We have evaluated a patient who had this febrile disease with arthritis and pericarditis. Pericardial tissue showed extensive deposition of IgG, IgM, and C3 both on the pericardial surface and within the walls of pericardial blood vessels. Our findings of immunoglobulins and complement within the inflamed pericardium suggest an immune-mediated mechanism for the pericarditis of acute rheumatic fever.

Adult↗