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Biomedical subjects

G Ramirez

Publications and source records attributed to G Ramirez.

At least 73 records · Page 4Linked to original sources

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

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

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

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

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

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

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

Combination chemotherapy for soft-tissue sarcomas: a phase III study.

A total of 144 patients with advanced sarcomas were entered into a randomized prospective protocol with four treatment arms utilizing different combinations of chemotherapeutic agents. Of these, 120 patients (83%) were judged acceptable. Treatment 1: actinomycin-D (Act-D), 0.01 mg/kg IV, days 1--5; phenylalanine mustard (L-PAM), 4 mg PO, days 1--10 every six weeks. Treatment 2: Act-D, 0.01 mg/kg IV, days 1--5; L-PAM, 4 mg PO, days 1--10; vincristine, 1 mg IV, days 1, 8, 15, 22, 29, 36, repeat every six weeks. Treatment 3: Act-D, 0.01 mg/kg IV, days 1--5; L-PAM, 4 mg PO, DAYS 1--10; NSC-1026, 200 mg/kg IV, days 1--6. Treatment 4: Adriamycin, 0.4 mg/kg IV, days 1, 2, 3, 8, 9, 10, then 2XWK starting day 15 (max. 1,200 mg). There was a provision that upon progression of the disease in the first three treatment regimens, patients would be crossed over to Treatment 4. Responses were as follows: 1 - Partial Response (PR) 1/25; No Change (NC) 9/25 (36%). gF2 - NC 17/26 (65%). 3 - NC 13/25 (52%). 4 - Complete Response (CR) 1/41; PR 6/41; (15%); NC 27/41 (66%). Clearly Treatment 4 was the best arm, with a 17% response rate and an initial progression rate of 17%. The only other response was a partial in 1. The difference is statistically significant (H = 17.247, P = 0.0006). If the responders to Adriamycin were analyzed without crossovers, the response rate would be 22% (6/27). (H = 14.079, P = 0.003). Median times to progression were 12.5, 8.7 weeks for 1 and 2, and 5 weeks for 3 and 4. There was no significant difference in the median survival times among the four treatment arms. It appears that Adriamycin as a single drug is superior to the drug combinations and would probably be even more effective used in combination with known active agents.

Antineoplastic Agents

Travelers' diarrhea among U.S. Army troops in South Korea.

A prospective study of diarrhea was conducted among 98 U.S. Army soldiers during their first six weeks in South Korea. Diarrhea developed in 54 (55%) of 98 soldiers and had a mean duration of five days. Infections with Salmonella, Shigella, Vibrio, enterotoxigenic Escherichia coli, enteroviruses, and intestinal parasites were uncommon. Four (8%) of 50 soldiers with documented diarrhea, two (6%) or 32 with a history of diarrhea, and one (3%) of 29 who denied gastrointestinal symptoms had serologic evidence of a recent rotavirus infection. The etiology of diarrhea among U.S. soldiers who had recently arrived in South Korea differed from the etiology among travelers in warmer climates, where enterotoxigenic strains of E. coli were responsible for the majority of cases. Further efforts are needed to define other enteric pathogens in the etiology of diarrhea among new arrivals in different parts of the world.

Diarrhea

Treatment of carcinoma of base of tongue with radiation therapy and 5-fluorouracil. Potential for optimization with 18F-FU.

The treatment of advanced base of tongue carcinoma with concurrent radiation therapy and 5-fluorouracil versus radiation therapy alone is compared. Although the results are inconclusive, it is noteworthy that all the 5-year survivors were patients given combined treatment. Important questions regarding optimization of time-dose relationships with combined therapy were generated. Accordingly, 18F-5 fluorouracil was synthesized in an attempt to answer some of these questions.

Carcinoma, Squamous Cell

Carcinoma of the penis: analysis of 192 consecutive cases at the Instituto Nacional de Enfermedades Neoplasicas.

Between 1952 and 1976 192 consecutive cases of penile epidermoid carcinoma were seen at the Instituto Nacional de Enfermedades Neoplascias of Lima, Peru. The mean age when the disease developed was 60.5 years, with a peak incidence between 60 and 64 years (32 patients). No correlation was observed between extensive lesions of the shaft of the penis to high pathological staging. Clinical examination of the inguino-crural nodes is not a good criterion for staging. We wait six weeks after eradication of primary lesion before lymphadenectomy. No correlation exists between grade and pathological stage. When no lymph node was positive, the overall survival rate over five years was 90.69%; when lymph nodes were metastasized there was an overall survival rate over five years of only 9.39 percent. The coefficient of cancer versus noncancer cause of death was 1.25 for pathological stage I, 3.09 for pathological stage II, 4.83 for pathological stage III, and 10.000 for pathological stage IV. Our patients did have advanced disease, as 57.14% of deaths occurred at two years and 25.21% more at five years.

Adult

Serum C-peptide in renal failure patients following stimulation of pancreatic secretion.

We have demonstrated persistently elevated serum C-peptide concentrations in patients with chronic renal failure on chronic hemodialysis. A blunted serum C-peptide response to intravenous glucose, glucagon and tolbutamide was also found. However, the response to oral glucose stimulation was greater and more prolonged than in control subjects, probably related to the magnitude of hyperglycemia found in patients with chronic renal failure. These observations suggest the existence of a defect in the renal clearance of C-peptide although an abnormality in C-peptide secretion cannot be excluded.

Adult

Synovial sarcoma of the neck associated with previous head and neck radiation therapy.

Synovial sarcoma is a rare neoplasm that uncommonly arises in the neck. Fourteen years after facial and neck radiation therapy for acne, synovial sarcoma of the neck developed in a young man. Possible radiation-induced benign and malignant neoplasms that arise in the head and neck region, either of thyroid or extrathyroid origin, remain a continuing medical problem.

Acne Vulgaris

Hemangiopericytoma of the uterus: report of a case with a comprehensive review of the literature.

A case of locally recurrent and metastatic uterine hemangiopericytoma successfully treated with surgery, radiotherapy and chemotherapy is presented. The patient is alive without evidence of detectable tumor, 13 years after the initial diagnosis. Review of the literature revealed 64 reported cases of uterine hemangiopericytoma. The clinical features are not sufficiently characteristic to enable the diagnosis to be made preoperatively. However, with the help of histological and ultrastructural studies a definite diagnosis of hemangiopericytoma can be made. The primary treatment is radical surgery which usually involved total hysterectomy and bilateral salpingo-oophorectomy. The prognosis of uterine hemangiopericytoma is better than that of other sites. However, long follow-up of these patients is necessary because of the tendency to local and distant recurrence many years after the initial treatment. The recurrent tumor should be treated aggressively with surgery, radiotherapy, and chemotherapy as long-term survival is not unusual.

Adult

Yoshi 864 (1-propanol, 3,3'-iminodi-, dimethanesulfonate [ester], hydrochloride): a phase II study in solid tumors.

Two hundred and eight acceptable patients were treated with Yoshi 864 (2 mg/kg/day by iv push X 5 days repeated once every 6 weeks). Toxicity was minimal. There was an overall response rate of 11%. Cross resistance with other alkylating agents may not be present. Because of its lack of toxicity, Yoshi 864 should be further evaluated in chronic myelocytic leukemia, lymphomas, and carcinomas of the ovary and bladder where significant responses were seen. It should also be evaluated in combinations as a replacement for other alkylating agents which cause more nausea and vomiting.

Alkylating Agents