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Biomedical subjects

R C Stern

Publications and source records attributed to R C Stern.

At least 109 records · Page 6Linked to original sources
PubMed1981

Changes in lymphocyte reactivity to Pseudomonas aeruginosa in hospitalized patients with cystic fibrosis.

In vitro lymphocyte proliferative responses to Pseudomonas aeruginosa (PA) and Staphylococcus aureus were studied in 38 patients with cystic fibrosis admitted for treatment of deteriorating pulmonary status. All patients were examined at admission and at least once after an average of 2 wk of treatment. Case history scores at admission and clinical responses to treatment were assessed independently. Patients were divided, according to their initial reactivity to PA, into low responder and responder groups. Twenty-nine patients were low responders to PA at admission. Eight of the patients in this group also had abnormally low responses to SA. After treatment, 10 patients became PA responders, whereas 19 had persistently low responses to PA. Nine of ten patients who subsequently died were in this persistently low responder group. Nine patients were responders at admission, and 8 remained in this category after treatment. These findings indicated that patients with cystic fibrosis have abnormal lymphocyte proliferative responses to killed bacteria. This dysfunction is acquired, and reversible in some patients in association with clinical improvement after intensive intravenous antimicrobial treatment. Once established, lymphocyte unresponsiveness may contribute to the progression of PA lung infection by impairing pulmonary macrophage activation by reactive lymphocytes.

Adolescent↗
PubMed1981

Influence of cystic fibrosis plasma on lymphocyte responses to Pseudomonas aeruginosa in vitro.

Peripheral blood lymphocytes from cystic fibrosis (CF) patients with advanced diseases do not proliferate following exposure to Pseudomonas aeruginosa (PA) antigen sin in vitro. In this study, we sought to determine if CF lymphocyte unresponsiveness to PA is due to inhibitory factors present in CF plasma. Nineteen low-responder CF (LRCF) patients increased their mean lymphocyte proliferative response (l3H]thymidine incorporation) from 703 +/- 133 to 3178 +/- 811 net cpm when incubated in normal plasma. These increase do not reach the level of response seen in normal individuals (8510 +/- 1323 net cpm). Ten of 19 patients did not increase their responses over 2000 net cpm. Plasma from LRCF patients does not inhibit responses of normal or homologous CF lymphocytes. Responses of normal individual in autologous plasma were 7807 +/- 1164 net cpm. Th same lymphocytes incubated in 16 plasmas from LRCF patients gave responses of 7146 +/- 1317 net cpm. Preincubation of the PA antigen in LRCF plasma increases rather than inhibits normal lymphocyte responses. LRCF plasma absorbed with PA no longer supports normal lymphocyte responses to PA. LRCF and normal plasma mixtures increase responses of normal lymphocytes to PA over responses in autologous plasma. Extensive preincubation and washing of LRCF lymphocytes to eliminate blocking immune complexes failed to restore the ability to respond to PA. These data suggest that the unresponsiveness to PA of lymphocytes from CF patients with advanced disease is due to alterations occurring at a cellular level in vivo. This lymphocyte dysfunction cannot be reversed by normal plasma in vitro, nor can it be induced in normal lymphocytes by the use of CF plasma.

Adult↗
PubMed1981

Are measurements of urine enzymes useful during aminoglycoside therapy?

We prospectively evaluated concentrations of beta-D-galactosidase, alpha-L-fucosidase, beta-D-N-acetylglucosaminidase, and lysozyme in urine from normal subjects, ambulatory patients with cystic fibrosis (CF), and CF patients with previously normal renal function who were receiving intravenous aminoglycoside (AG) therapy. Enzyme activities were generally low or negligible in subjects not receiving AG. Enzymuria was documented during 12 of 13 AG treatment courses and most frequently involved beta-D-N-acetylglucosaminidase excretion. In nine courses, enzymuria occurred in the absence of proteinuria or elevations of blood urea nitrogen and serum creatinine. In three courses attended by enzymuria and evidence of nephrotoxicity, neither the time of appearance nor the magnitude of enzymuria was different from that of nonnephrotoxic patients. In two of these three treatment courses, enzymuria preceded clinical evidence of nephrotoxicity of 16 and 5 days, and in the third course enzymuria and elevation of blood urea nitrogen and serum creatinine occurred simultaneously. We conclude that enzymuria is not a reliable predictor of nephrotoxicity due to AG in CF patients and is not an indication of discontinue AG therapy.

Acetylglucosaminidase↗
PubMed1981

Exercise conditioning and cardiopulmonary fitness in cystic fibrosis. The effects of a three-month supervised running program.

Exercise intolerance is common in cystic fibrosis (CF). We examined the effects of a supervised three-month running program on exercise tolerance, pulmonary function, cardiorespiratory fitness (peak oxygen consumption), and respiratory muscle endurance in CF patients. We studied 31 patients, 21 exercise and ten control, aged 10 to 30 years, with pulmonary involvement ranging from mild to severe. The exercise and control groups were not significantly different with respect to age, sex, pulmonary function, exercise tolerance, or cardiorespiratory fitness. After three months of physical conditioning, the exercise group had significantly increased exercise tolerance and peak oxygen consumption and significantly lower heart rates for submaximal work loads, while the nonexercising (control) group was unchanged in all these variables. The FEV1 decreased significantly in the control group. There were no other significant changes in pulmonary function in either the control or exercise group. Respiratory muscle endurance increased significantly in the exercise patients, and did not change in the control patients. There were no adverse effects of the program. The data suggest that a supervised running program can increase CF patients' exercise tolerance and cardiorespiratory fitness, perhaps in part by increasing respiratory muscle tolerance. The effects of a much longer program deserve study.

Adolescent↗
PubMed1981

Psychosocial functioning of children with cystic fibrosis.

The adjustment of children with cystic fibrosis as rated by parents and teachers was compared to that of physically healthy siblings, normal children, and other chronically ill children. The findings indicated that children with cystic fibrosis achieved an age-adequate level of adjustment at home and school. Adjustment was largely unrelated to the severity of cystic fibrosis. As a group, chronically ill children had less adequate adjustment as rated by parents. However, severe adjustment problems were relatively rare. These findings are consistent with a growing body of literature which suggests that children with cystic fibrosis can cope reasonably well with life tasks and that emotional disturbance is not an inevitable consequence of the disease. Future studies of the cystic fibrosis population should study factors which differentiate adjusted from maladjusted children.

Adolescent↗
PubMed1980

Heart failure in cystic fibrosis. Treatment and prognosis of cor pulmonale with failure of the right side of the heart.

Failure of the right side of the heart with cardiac dilation and fluid retention occurred in 55 of 170 patients who died of cystic fibrosis; six patients survive. All had severe hypoxia, but 24% had normal PaCO2. Cardiac catheterization showed high mean pulmonary artery pressure and resistance. Pulmonary artery wedge pressure was greater than 12 mm Hg in 40% of the patients. Mean survival was eight months. Male survival was significantly better than female survival. Digitalis treatment was of no clear benefit. Tolazoline hydrochloride was also ineffective. Recent medical advances have not substantially affected prognosis.

Adolescent↗
PubMed1980

Partial resolution of bone lesions. A child with severe combined immunodeficiency disease and adenosine deaminase deficiency after enzyme-replacement therapy.

A child with severe combined immunodeficiency disease and adenosine deaminase deficiency, with characteristic bone dysplasia, was treated with transfusions of frozen irradiated RBCs as a means of enzyme replacement. This therapy resulted in restoration of immunologic competence and partial resolution of the bone lesions. Although the natural history of these lesions without therapy is not known, enzyme-replacement therapy may have played a role in the resolution of this patient's bone lesions.

Adenosine Deaminase↗
PubMed1979

Multiple of isolates of Pseudomonas aeruginosa with differing antimicrobial susceptibility patterns from patients with cystic fibrosis.

Clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis were studied in an effort to determine the unique characteristics of the infecting strains and to elucidate the pattern of colonization. Of 413 patients studied, 81% were chronically infected with P. aeruginosa. Patients from whom P. aeruginosa was never or only occasionally isolated were in better clinical condition than the chronically infected patients. Isolates were classified into six morphologic varieties: classic, rough, mucoid, gelatinous, dwarf, and enterobacter. Most patients had two or more of these varieties. Such multiple varieties from the same individual were of the same serotype but often differed in antibiotic susceptibility as determined by both the disk and the minimal inhibitory concentration methods. These differences were apparent when mucoid strains were compared with nonmucoid strains and when nonmucoid strains were compared with one another. Studies of antibiotic susceptibility should be performed on each morphologically different type of P. aeruginosa obtained from patients with cystic fibrosis.

Adolescent↗
PubMed1979

Defective cellular immunity to gram-negative bacteria in cystic fibrosis patients.

In vitro lymphocyte responses to Pseudomonas aeruginosa have been found to be impaired in cystic fibrosis patients with advanced clinical disease. The responses to Klebsiella pneumoniae, Serratia marcescens, and Proteus mirabilis were studied in a similar group of cystic fibrosis patients and normal individuals. Cystic fibrosis patients found to be unresponsive to pseudomonas were also unresponsive to klebsiella, serratia, and proteus. Responsiveness to Staphylococcus aureus was not impaired in cystic fibrosis patients. We postulate that in vitro lymphocyte responses to several gram-negative bacteria require the function of a lymphocyte subpopulation which may be impaired in some cystic fibrosis patients.

Antigens, Bacterial↗
PubMed1978

Intermediate-range sweat chloride concentration and Pseudomonas bronchitis. A cystic fibrosis variant with preservation of exocrine pancreatic function.

We studied the clinical and laboratory characteristics of seven patients with sweat chloride concentration consistently between 40 and 60 mEq/liter. Each has chronic Pseudomonas bronchitis, and all lack digestive symptoms. Laboratory findings indicate the preservation of exocrine pancreatic function. The patients include two of five children in one family and two of four in another. In a third family, one of five siblings has an intermediate sweat chloride concentration, but another has a typical fibrosis value (105 mEq/liter). One patient died of respiratory failure; results of an autopsy showed bronchiolectasis typical of cystic fibrosis, but minimal pancreatic changes. The data suggest a genetic basis for this variant of cystic fibrosis. These patients may be homozygous for a portion of a closely linked multigene cystic fibrosis locus or may have modifier genes that ameliorate the pancreatic and sweat lesions.

Adolescent↗
PubMed1978

Effect of blood group determinants on binding of human salivary mucous glycoproteins to influenza virus.

We have demonstrated that the inhibitor of influenza B virus hemagglutination in human saliva is inactivated by neuraminidase and is associated with the mucous glycoprotein fraction (blood group substance) of this secretion. Inhibitory activity of saliva was found to be roughly proportional to its sialic acid content (r = 0.456). However, the minimal quantity of salivary sialic acid, neutral sugar, or blood group antigen required to inhibit virus hemagglutination was greater for secretors of A and B than for secretors of H and Lea blood group substances. Removal of terminal galactose from blood group B substance with alpha-galactosidase markedly decreased blood group B activity but increased blood group H and virus hemagglutination inhibitory activities of this glycoprotein. These data suggest that terminal alpha-linked galactose and, probably, N-acetyl-galactosamine interfere with access of influenza virus to binding sites on oligosaccharide chains of the mucous glycoprotein.

ABO Blood-Group System↗