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Biomedical subjects

Y Schwarz

Publications and source records attributed to Y Schwarz.

31 records · Page 2Linked to original sources
PubMed1995

Changes in sensitivity to methacholine after inhalation with distilled water: the role of the bronchoconstrictive response.

The inhalation of distilled water can induce bronchoconstriction and a transient increase in sensitivity to methacholine in asthmatics. The purpose of this study was to determine the role of the induced bronchoconstriction in the increased sensitivity to methacholine which follows the challenge with distilled water. Eighteen asthmatic children (age 9-17 yrs) were challenged by inhalation of distilled water. Bronchial responsiveness, the provocative concentration of methacholine producing a 20% decrease in forced expiratory volume in one second (PC20), was determined before inhalation of distilled water, and 1.5 and 24 h thereafter. Following inhalation of distilled water, eight patients (Group I) had a greater than 15% decrease in FEV1 (mean 23%); whereas, in the remaining 10 (Group II) the decrease was less than 7% (mean 1%). PC20 to methacholine, geometric mean and 95% confidence interval (CI), decreased transiently only at 1.5 h following inhalation of distilled water. The decrease was from 0.78 mg.ml-1 (95% CI 0.11-5.54 mg.ml-1) at baseline to 0.25 mg.ml-1 (95% CI 0.03-2.14 mg.ml-1) after challenge in Group I; and from 2.67 mg.ml-1 (95% CI 0.35-20.34 mg.ml-1) at baseline to 0.72 mg.ml-1 (95% CI 0.18-14.87 mg.ml-1) after challenge in Group II. The transient increase in sensitivity to methacholine observed following inhalation of distilled water occurred independently of the bronchoconstrictive response. This finding may have important clinical implications when hypo-osmolar solutions are used for delivery of drugs.

Adolescent↗
PubMed1994

Meiosis-dependent tyrosine phosphorylation of a yeast protein related to the mouse p51ferT.

The FER locus of the mouse encodes two mRNA species: one is constitutively transcribed, giving rise to a 94 kDa tyrosine kinase (p94ferT); the second is a meiosis-specific RNA that gives rise to a 51 kDa tyrosine kinase (p51ferT). The p51ferT RNA and protein accumulate in primary spermatocytes that are in prophase of the first meiotic division. By using polyclonal antibodies directed against synthetic peptides derived from the unique amino-terminus of the mouse p51ferT, a 51 kDa phosphotyrosyl protein --p51y-- was identified in Saccharomyces cerevisiae. The p51y protein is constitutively expressed in yeast, but in meiotic cells, concomitantly with commitment to meiotic recombination, its level of phosphorylation on tyrosine residues is increased. A different pattern of phosphorylation is observed on serine residues: at early meiotic times the level is decreased, while in later meiotic time the level increases, reaching the vegetative level. When p51ferT is ectopically expressed in yeast, it is active, leading to preferential phosphorylation of an approx. 65 kDa protein. A similar pattern of phosphorylation by p51ferT is seen in mammalian cells.

Animals↗
PubMed1994

Evaluation of asymptomatic subjects with low forced expiratory ratios (FEV1/VC).

BACKGROUND: Heightened bronchial hyperreactivity is frequently associated with airflow limitation, atopy, or cigarette smoking. The purpose of this study was to evaluate healthy subjects with significantly low values of forced expiratory volume in one second/vital capacity % (FEV1/VC%) by measuring their airway response to exercise and methacholine challenge, compared with a control group with normal spirometric values. METHODS: Eighty four healthy subjects with significantly low flow rates (group A, FEV1/VC% < 2 SD% predicted) were evaluated and compared with 37 subjects with normal flow rates (group B). Static lung volumes, spirometric tests, exercise, and methacholine challenges were performed. RESULTS: Lung volumes were normal for both groups. Mean FEV1/VC% was 69% for group A and 82% for the control group. Salbutamol improved baseline FEV1 in eight subjects in group A (mean 15%), while methacholine induced a drop in FEV1 in 12 subjects. The dose-response curve to methacholine reached a plateau in all the responders. None of the subjects in the control group improved their baseline FEV1/VC% to salbutamol, but three showed bronchial hyperreactivity similar to those in group A. CONCLUSIONS: Bronchial hyperreactivity does not occur more often in asymptomatic subjects with mildly low FEV1/VC% so these subjects do not require special investigations for airway disease.

Adolescent↗
PubMed1994

Effect of budesonide on bronchial hyperresponsiveness and pulmonary function in patients with mild to moderate asthma.

Thirty-nine subjects were included in this double-blind, placebo-controlled study of bronchial hyperresponsiveness (BHR) in patients with mild to moderate asthma. The time-courses of change of FEV1, PEFR%, bronchial reactivity, and daily measures of asthma control were determined during 8 weeks of treatment after a run-in period of 2 weeks. Bronchial hyperresponsiveness was assessed by the methacholine provocation method, defined as the dose of methacholine causing a 20% fall of FEV1 compared with baseline values. The trends of FEV1 and the percentage change in PEFR from baseline were significantly different between groups, in favor of budesonide (P < .05). Patient assessments of the effect of treatment showed that PEF improved significantly in the budesonide group only. The budesonide group increased their tolerability for methacholine provocation by 1.8 DD (doubling dose), which tended to be higher compared with the 0.8 DD of the placebo group. It is evident from this study and previous studies that more data are needed to establish the dose-effect relationship with time and severity of the disease.

Adolescent↗
PubMed1993

Mite asthma in childhood: a study of the relationship between exposure to house dust mites and disease activity.

BACKGROUND: Children with asthma are commonly sensitized to the house dust mite. METHODS: We took monthly measurements from July to December of the amount of mites in the mattresses of asthmatic children and correlated them with symptom score, pulmonary function, and airway hyperreactivity to methacholine. RESULTS: In spite of the high number of Dermatophagoides pteronyssinus throughout this period, symptom and treatment scores, as well as PC20 to methacholine, worsened during the months of September and October. CONCLUSIONS: It is concluded that when asthmatic children allergic to mites are exposed to high levels of mite allergen, the number of mites in the mattress dust no longer correlate with increased symptoms, and that other factors are more likely to be associated with exacerbation.

Adolescent↗
PubMed1992

The association of perennial rhinitis with Trichophyton infection.

Trichophyton was recently reported to be the cause of respiratory allergy in patients with severe bronchial asthma. We describe eight patients with perennial rhinitis in combination with skin or toe-nail infection, in whom Type I hypersensitivity reaction to Trichophyton was confirmed by skin test, RAST and nasal provocation. When treated with oral fungicidal therapy, there was significant improvement in both their skin and nasal symptoms. Local therapy produced only a mild, transient improvement. We emphasize the need for thorough evaluations in patients with respiratory allergies and negative routine skin tests.

Administration, Oral↗
PubMed1990

Resting energy expenditure in injured, septic, and malnourished adult patients on intravenous diets.

Energy expenditures of 237 adult patients and 37 normal subjects receiving all nutrition intravenously were analysed retrospectively. Patients were classified as nutritionally depleted (67), post-operative (96), injured (43), or septic/depleted (31). Groups were further divided into those receiving either: (1) only 5% dextrose (D5W); (2) hypocaloric regimens including glucose and amino-acids; and (3) eucaloric or hypercaloric total parenteral nutrition (TPN) which also included fat. Resting energy expenditures (REE) of normal subjects on D5W were only 85% of predicted basal values based on either the Aub-Du Bois or Harris-Benedict equations. During D5W infusions, increases for the patient groups, above these values for normal subjects, varied depending on whether they were based on absolute values or ratios to predicted values. They were: (1) 1-11% for depleted; 1-21% for post-operative; 28-30% for injured; and 18-30% for septic/depleted patients. The average increase in REE with TPN was 10%. Variability within the patient groups was high, reducing the utility of these values as a basis for estimating energy requirements of patients needing artificial nutrition. Coefficients of variation averaged 15% across patient groups when the data were expressed in kJ/kg, and were reduced only slightly, to 12%, when data were expressed as ratios to predicted values. Thus, 1 3 of the patients would differ by more than 12% from mean values, and 1 out of 20 by more than 24%. Properly performed measurements of individual energy expenditure are therefore superior to values predicted from equations or average values previously obtained from patient groups and should be used wherever possible, particularly in the very sick.

Journal Article↗
PubMed1990

Effects of glucose on nitrogen balance during high nitrogen intake in malnourished patients.

1. The effects of increasing glucose intake on nitrogen balance, energy expenditure and fuel utilization were measured in 12 malnourished adult patients receiving parenteral nutrition with constant, very high nitrogen intake (500 mg of N/kg), high (105 kJ/kg) or low (30 kJ/kg) glucose intake and constant fat intake (7 kJ/kg). Each patient received each diet for 8-day periods in random order. 2. Energy balance and nitrogen balance were determined daily. Blood samples, taken at admission, during 5% (w/v) dextrose (D-glucose) infusion and at the end of days 7 and 8 of each diet, were analysed for urea, glucose, lactate, triacylglycerols, fatty acids, glycerol, 3-hydroxybutyrate, insulin and glucagon. 3. The effect of increasing glucose intake was to increase nitrogen balance by 0.60 +/- 0.25 (SEM) mg/kJ. At zero energy balance, nitrogen balance was 48 mg day-1 kg-1. This confirms findings of previous studies: that the effects of glucose on nitrogen balance are greater at high than at low nitrogen intakes, and that, in malnourished patients, unlike in normal adults, markedly positive nitrogen balance can be achieved at zero or negative energy balances. 4. Changes in nitrogen balance were due almost entirely to changes in urea excretion. 5. The high nitrogen intake markedly increased plasma insulin and glucagon concentrations and reduced glycerol, fatty acid and 3-hydroxybutyrate concentrations, independent of any glucose effect. Glucagon concentrations were significantly decreased by added glucose intake, an effect not previously seen at low nitrogen intakes. At this high nitrogen intake, the effects of added glucose appear to be mediated by both insulin and glucagon.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗
PubMed1987

Energy measurements and requirements of critically ill patients.

The energy expenditure of the critically ill patient is influenced by many factors, thus making it difficult to predict. Measurement of energy expenditure in mechanically ventilated patients receiving elevated oxygen concentrations requires a good understanding of the measurement technique and its limitations, whether it be the gas exchange or Fick method. More investigation is needed to better understand the determinants of energy expenditure, as well as the total energy requirements of the critically ill patient.

Critical Care↗
PubMed1983

Effects of increasing nitrogen intake on nitrogen balance and energy expenditure in nutritionally depleted adult patients receiving parenteral nutrition.

The effects of increasing nitrogen intake were studied in 10 nutritionally depleted patients receiving total parenteral nutrition. After 1 to 2 days on 5% dextrose, the patients received, in random order, intravenous diets containing either a low (180 mg/kg . day) or high (364 mg/kg . day) nitrogen content. Equicaloric amounts of glucose and fat emulsion were given. Total energy intake averaged 33.0 kcal/kg . day corresponding to 1.31 X resting energy expenditure or 1.08 X total energy expenditure. Nitrogen and energy balances were measured daily. Concentrations of glucose, glycerol, fatty acids, triglycerides, urea, insulin and glucagon in plasma, and of beta-hydroxybutyrate in whole blood were measured during the last 2 days of each diet period. An increase in plasma urea was the only change in hormone or substrate concentrations identified. Resting energy expenditure increased approximately 10%, going from 5% dextrose to the low and from the low to the high N diet. Nitrogen balances were 0.21 and 0.61 mg N/kg . day on the low and high N diets. Nitrogen retention of 21% of the increment in intake, three times that seen in normal adult subjects, indicates that the malnourished patients in this study responded in a manner similar to growing organisms. Attainment of markedly positive N balance at, or close to, zero energy balance indicates that lean body mass can be restored without excessive energy intakes which may often be undesirable.

Adaptation, Physiological↗
PubMed1965

Production of egg yolk coloring material by a fermentation process.

Rhodotorula mucilaginosa was cultivated in a yeast propagator, for the production of biomass and carotenoids. A spray-dried preparation of the yeast was incorporated into the diets of laying chickens for the promotion of egg yolk color. Several aspects of the effect of media on growth and carotenogenesis of pigmented yeast were examined. Addition of 1 to 2% of Rhodotorula yeast to the feeding mixture considerably improved egg yolk color. The possibility of using carotenogenic yeasts as a feed supplement is suggested.

Animals↗
PubMedDate not supplied

Percutaneous core needle biopsy vs. fine needle aspiration in diagnosing benign lung lesions.

OBJECTIVE: To determine the diagnostic value of percutaneous core needle biopsy (PCNB) in comparison with fine needle aspiration (FNA) in patients with benign pulmonary lesions. STUDY DESIGN: A retrospective review was undertaken of computed tomography-guided PCNBs and FNAs performed between 1988 and 1997. Both FNA and PCNB biopsies were carried out sequentially at the same visit in every patient. RESULTS: A specific benign diagnosis was made in 10/60 cases (16.7%) by FNA and in 49/60 (81.7%) by PCNB. PCNB findings resulted in significant modification of the diagnosis established by FNA. The only significant complication encountered was pneumothorax, at a rate of 11.7%, which is compatible with that reported in the literature for complications induced by FNA alone. CONCLUSION: Radiologically guided PCNB is a safe procedure, can provide sufficient histologic material for a specific diagnosis of peripheral lung disease and can avoid more-invasive surgical procedures in many cases. Our experience demonstrated that the histologic analysis provided by PCNB can greatly increase the diagnostic accuracy in benign pulmonary diseases as compared with the yield of FNA.

Adult↗