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Biomedical subjects

S Alvarez

Publications and source records attributed to S Alvarez.

At least 127 records · Page 7Linked to original sources
PubMed1987

Human embryo cryopreservation, extrinsic and intrinsic parameters of success.

Freezing and thawing (F - T) was applied to 490 early human embryos using propanediol as cryoprotectant. The survival rate of embryos frozen with propanediol alone did not exceed 31% (26/83). The combination of propanediol and sucrose, however, significantly increased the percentage of surviving (248/407 = 61%) and intact (188/407 = 46%) embryos and seemed to enhance embryo viability as suggested by the implantation rate (14.5 versus 8%) without, however, any statistical significance. Embryo survival, but not viability, was correlated with morphological features, whereas neither the age of embryos (1, 2 or 3 days post-insemination) nor the segmentation stage (regular or intermediate) were involved in F - T ability. Thirty-eight F - T embryos implanted when replaced in utero, representing 8% of all F - T embryos and 14% of the F - T replaced embryos. The pregnancy rate per transfer reached 19% (35/185) and was identical to the pregnancy rate per transfer of fresh embryos (253/1149 = 22%). In oocyte donation, too, embryo freezing did not impair the pregnancy rate (25%). In spontaneous cycles, synchronous transfer gave better results than asynchronous transfers (20 versus 10%), but spontaneous cycles had no significant advantage (16% pregnancy/transfer) as compared to stimulated (26%) and artificial (27%) cycles.

Blastomeres↗
PubMed1987

Enterobacter pneumonia.

Enterobacter species have not been well recognized as important lower respiratory tract pathogens. We describe 11 cases of Enterobacter pneumonia, seven diagnosed by transtracheal aspiration and four by simultaneous blood and sputum cultures. The infections were usually nosocomial, and were fatal in five patients. Our patients were old (mean age 65 +/- 12.3 years) with chronic obstructive pulmonary disease (COPD) as a common underlying disease. Enterobacter species are important pathogens causing nosocomial pneumonias, especially in elderly patients with COPD.

Adult↗
PubMed1987

Two-stage skin testing for tuberculosis in a domiciliary population.

We scheduled two-stage skin testing for tuberculosis with Candida and mumps controls on 618 residents of our domiciliary unit at the Veterans Administration Medical Center, Johnson City, Tennessee. Of the 618 residents in the unit, 30 (4.8%) were not available for evaluation, 77 (13%) had a prior history of active tuberculosis or positive skin test, and 1 resident refused testing. Of these 510 patients who received first-step testing with purified protein derivative (PPD), 153 (30%) had greater than to 10 mm induration. Those patients with less than 10 mm induration had a repeat PPD 2 wk later. Fifty-nine (19.2%) of the 307 patients who received a second PPD had a booster response. A total of 50.9% of the residents had evidence of tuberculosis exposure by skin testing. There were no differences between patients with significant and nonsignificant reactions when comparing age, length of stay, functional status evaluated by Karnofsky scale, or number of underlying diseases. Second test conversion occurred in 4.3% of those patients who had been in the unit for less than 1 month and in 36% of those who had been residents for a period of 3 to 6 months (p less than 0.05). Regardless of the size of the initial reading, it is important to perform a two-stage PPD in residents of chronic care facilities who have a negative first test. INH prophylaxis should be considered in patients admitted to chronic care facilities such as the domiciliary when they have significant Mantoux reactions.

Adult↗
PubMed1987

Transfer of tuberculin immunity from mother to infant.

The purpose of our study was to investigate transfer of tuberculin immunity from mother to infant via breast milk by studying newborn lymphocyte blastogenesis induced by purified protein derivative antigen at 1-5 days of age, 4-6 wk of age, and 3 months of age. Our study consisted of four mother-infant groups: breast-feeding and bottle-feeding infants of tuberculin-positive and tuberculin-negative mothers. A difference in the groups was found only at 4-6 wk of age where 17% (4/23) of breast-feeding infants and 13% (2/15) of bottle-feeding infants of tuberculin positive mothers had lymphocyte blastogenesis to purified protein derivative. None of the infants of tuberculin negative mothers had purified protein derivative-induced blastogenesis. Analysis of covariance with tests for equality of slopes showed that the responses of tuberculin-positive mothers were significantly different from the responses of tuberculin-negative mothers (p less than 0.05). These studies suggest transplacental transfer of tuberculin immunity evident at 4-6 wk of age which wanes by 3 months of age. We could not find evidence of transfer via human milk.

Adult↗
PubMed1987

Enhancement of immune response in mice fed with Streptococcus thermophilus and Lactobacillus acidophilus.

Swiss mice, fed for 8 consecutive d with 50 micrograms/d of viable cultures of Lactobacillus acidophilus and Streptococcus thermophilus, showed significant variation in their immune system. In order to study this phenomenon assays for macrophage and lymphocyte function were carried out. Both lactic acid bacteria enhanced significantly the enzymatic and phagocytic activity of peritoneal macrophages as checked against the controls and also accelerated the phagocytic function of the reticuloendothelial system as revealed by the carbon clearance test. On the 2nd d (100 micrograms), L. acidophilus reached a peak of K = .271, which remained high. Streptococcus thermophilus was effective only on the 2nd d and then decreased. The lymphocytic activity studied by immunoglobulin secreting cells was assayed by Jerne's method of plaque-forming cells (PFC). This activity also was increased by the two microorganisms. Streptococcus thermophilus proved more effective than L. acidophilus. Lactobacillus acidophilus and S. thermophilus activated macrophages and lymphocytes and produced the same increase in the immune response of mice whether administered orally or intraperitoneally.

Administration, Oral↗
PubMed1987

Clinical and epidemiologic features of strongyloidiasis. A prospective study in rural Tennessee.

Hospitalized and domiciliary patients were studied to determine the incidence of the endemic nematode Strongyloides stercoralls in stool samples. Strongyloides was found in 14 (6.1%) of 229 hospitalized patients and in nine (2.6%) of 346 domiciliary patients. Clinical symptoms, laboratory data, and underlying diseases were compared for stool-positive and stool-negative patients. Infected patients were more likely to complain of abdominal bloating. They had a higher incidence of eosinophilia and guaiac-positive stools. They were more likely to have been treated with corticosteroids, cimetidine, and antacids. Efficacy of treatment with thiabendazole was studied in all stool-positive patients; a relapse rate of 15% was noted with standard thiabendazole therapy.

Aged↗
PubMed1986

Corynebacterium minutissimum bacteremia in a patient with chronic myeloid leukemia in blast crisis.

Serious infections and sepsis due to nondiphtheria Corynebacteria have been well described. A patient with chronic myeloid leukemia in blast crisis, who developed Corynebacterium minutissimum bacteremia, is described in this report. Corynebacterium minutissimum is the causative agent of erythrasma and to our knowledge, this is the first published report of septicemia due to this organism.

Blast Crisis↗
PubMed1986

Progressive pulmonary disease caused by Mycobacterium gordonae.

Mycobacterium gordonae has been considered a true saprophyte of the respiratory tract, unable to produce pulmonary disease. We have reported a case of progressive pulmonary disease due to Mycobacterium gordonae which has failed to improve with multiple combinations of antituberculous drugs over a period of eight years.

Antitubercular Agents↗
PubMed1986

Branhamella catarrhalis pneumonia in patients with immunoglobulin abnormalities.

The importance of Branhamella catarrhalis pneumonia has only recently been appreciated. Predisposing underlying illness associated with this organism have not yet been clarified. We report five cases of Branhamella catarrhalis pneumonia occurring in patients with diseases associated with documented quantitative immunoglobulin deficiencies. Normal immunoglobulins appear to be important host defense mechanisms in preventing infection with this organism.

Adult↗
PubMed1986

Effect of perorally administered lactobacilli on macrophage activation in mice.

The effect of perorally (p.o) administered Lactobacillus casei and L. bulgaricus on macrophage activation in mice was studied. L. casei and L. bulgaricus were administered p.o. to mice for 8 days. The macrophage activation was measured on days 2, 3, 5, and 8 of lactobacillus administration by using biochemical and functional criteria. We measured the release of lysosomal hydrolases, the level of a nonlysosomal enzyme, and in vitro phagocytic activity of mouse peritoneal macrophages. All the assays were performed comparatively with mice inoculated with L. casei and L. bulgaricus (viable and nonviable cells) intraperitoneally (i.p.) at the same dose as for p.o. administration. The phagocytic activity was significantly higher in mice treated i.p. than in control mice. For p.o. administration, there was an increase only when L. casei was used. L. bulgaricus had little effect. No differences were found between viable and nonviable cells. The phagocytic function of the reticuloendothelial system was tested by the carbon clearance test, which showed that L. casei and L. bulgaricus accelerate the phagocytic function in mice treated p.o and i.p., from day 2 onward. These observations show that L. casei and L. bulgaricus given by p.o. administration are able to activate macrophages in mice and suggest that these bacteria, when passing through the intestinal tract, may be responsible for the enhanced host immune response. This fact is very significant because the diet includes fermented and manufactured products containing lactobacilli.

Administration, Oral↗
PubMed1986

Nosocomial pneumococcal bacteremia.

In five years we studied 56 episodes of pneumococcal bacteremia. Twenty-three (41%) were nosocomial and 33 (59%) community acquired. Most of our patients were elderly men with multiple underlying diseases; however, those patients with nosocomial infections had a significantly higher incidence of malignant neoplasms (57% vs 24%), poor functional status (70% vs 25%), and ultimately fatal underlying disease (61% vs 21%). Alcoholism was more common among the patients with community-acquired bacteremia (45% vs 17%). Nosocomial infections carried a significantly higher overall mortality (73.9% vs 45.4%). The mortality directly related to the pneumococcal bacteremia was also higher (52% vs 39%), but not significantly. Most of the isolated strains were serotypes present in the new pneumococcal vaccine, which only one study patient had received. Mixed pneumococcal bacteremia with gram-negative bacilli was more frequent in nosocomial infections. Streptococcus pneumoniae can be a nosocomial pathogen in elderly, debilitated patients. Pneumococcal vaccination should be incorporated in a hospital-based prevention program for high-risk patients.

Aged↗
PubMed1986

Vaccinating the elderly: recommendations and rationale.

Pneumococcal vaccination is given only once. It is not currently recommended that patients who have been given the 14-valent vaccine be revaccinated with the newer 23-valent vaccine. Vaccination is more difficult for influenza than for pneumococcal pneumonia. An understanding of the annual changes in influenza vaccine recommendations requires some knowledge of the virus' ability to undergo antigenic variation and produce different strains each year.

Aged↗
PubMed1986

Clinical and microbiologic consequences of amikacin use during a 42-month period.

In June 1980, 23% of our Pseudomonas aeruginosa isolates and 53% of our Serratia species were resistant to gentamicin and tobramycin. During a 3 1/2-year period of almost exclusive amikacin usage, we noted a fall in overall resistance of gram-negative organisms to tobramycin and gentamicin from 18.8% and 19.3% to 15.2% and 16.2%, respectively. This fall in resistance was most notable for Escherichia coli, Proteus mirabilis, and Serratia species. During this period there was no increase in amikacin resistance. Age, hospitalization, prior antibiotic therapy, and Foley catheter use were predisposing factors in acquiring amikacin-resistant organisms. Amikacin-resistant gram-negative bacilli were usually sensitive to newer penicillins or cephalosporins.

Age Factors↗
PubMed1985

Pneumonia caused by gram-negative bacilli.

Gram-negative bacillary pneumonia has become an increasingly important disease in immunosuppressed, elderly, and hospitalized patients. The clinical features, etiologic agents, population at risk, treatment, and outcome in patients with well-documented gram-negative pneumonia were compared in two groups of patients: those with bacteremic pneumonia and those with nonbacteremic pneumonia documented by transtracheal aspiration. Clinical features were frequently subtle in both groups. A wide range of gram-negative bacilli were implicated as pathogens and pneumonias documented by transtracheal aspiration were frequently mixed infections. Pseudomonas aeruginosa and Serratia marcescens were the most common pathogens causing bacteremic pneumonias, whereas Escherichia coli and Klebsiella were more common in the nonbacteremic group. Gram-negative bacillary pneumonia was frequently a lethal disease despite two-drug therapy, particularly in bacteremic patients.

Age Factors↗