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Biomedical subjects

A Katz

Publications and source records attributed to A Katz.

At least 397 records · Page 22Linked to original sources
PubMed1986

Selective effect of nortriptyline on smooth muscle as an anticholinergic drug: a pharmacological and clinical study.

The anticholinergic potency of nortriptyline was studied on muscle strips from human bladder and ileum. Concurrently the effect of nortriptyline low dosage therapy was studied in 21 women suffering from motor or sensory urgency and urge incontinence. Analysis of the results by the dose ratio method showed a significant difference in the affinity of the anticholinergic receptors to the antagonist. The Ki values were 0.298 microM for the bladder and 0.938 microM for the ileum. In the clinical study, the condition of 15 (71.4%) women treated with notriptyline improved considerably. The higher affinity of the drug to the receptors in the bladder than to those in the ileum may explain the positive therapeutic effect of a relatively low dose of nortriptyline in over 70% of the patients treated.

Bethanechol Compounds↗
PubMed1986

Nonrecurrent laryngeal nerves and their clinical significance.

The anomalous position of a nonrecurrent laryngeal nerve predisposes the nerve to injury during thyroidectomy and to compression by a thyroid mass. We present three cases in which a seemingly benign thyroid mass traumatized a nonrecurrent laryngeal nerve resulting in either vocal cord paralysis or a vague pressure sensation over the larynx. Some of these patients feel as if they need to clear a foreign body and present with a chronic cough. Normally the nerve is protected from thyroid masses as it passes through the tracheoesophageal groove. In all three patients, surgical excision of the thyroid mass and release of the nerve resulted in recovery of the nerve and resolution of the symptoms. We have found that small, benign, or otherwise asymptomatic lesions of the thyroid gland have a greater tendency to cause vocal cord paralysis in patients with nonrecurrent laryngeal nerves. The surgeon must always be aware of the possibility of the presence of a nonrecurrent laryngeal nerve.

Adenoma↗
PubMed1986

Exercise increases the lung clearance of inhaled technetium-99m DTPA.

The regional lung clearance of a deposited aerosol of [99mTc] diethylenetriaminepentaacetic acid was successively computed at rest and at exercise in seven nonsmoking volunteers in upright posture. The subjects were seated on a bicycle with their backs against a gamma camera. At rest there was a gradient of clearance from the apex to the base of the lung, the apical clearance being significantly higher. At exercise this regional gradient was enhanced by a large and significant increase of the apical clearances (3.40 +/- 0.63% min-1 s.d. compared with 1.82 +/- 0.75% min-1 s.d. at rest, n = 7, p less than 0.01). By contrast the changes of the basal clearances were slight and unsignificant (1.46 +/- 0.71% min-1 s.d. compared with 1.40 +/- 0.82% min-1 s.d.). This increase of the apical lung clearance could be attributed primarily to the increase of apical blood flow induced by exercise and to the subsequent increase of the permeability surface area product.

Adult↗
PubMed1986

Comparison of the postburn hyperdynamic state and changes in lung function (effect of wound bacterial content).

The pulmonary and systemic response to a full-thickness burn (15% of total body surface area) was determined in 15 adult sheep. Also compared was the effect of wound bacterial content and prostanoid release on this response. Burn wound thromboxane A2, measured as TxB2, and prostacyclin, measured as 6-keto-PGF1 alpha, were measured in burn wound lymph. Animals were monitored for 7 days. On the final day, a full-thickness biopsy specimen of burn tissue was obtained for quantitative bacteriology. Wounds with 10(4) or less organisms per gram of burn tissue were considered colonized, whereas those with 10(5) or more organisms per gram of burn tissue indicated wound infection. Seven sheep had 10(4) or less bacteria and the remaining eight sheep had 10(6) or greater bacteria. We noted a significant mean increase in cardiac index from a baseline of 5 to 6.2 L/min/m2, a decrease in systemic vascular resistance from 16 to 12 mm Hg/L/min, and a mean increase in oxygen consumption from a baseline of 135 to 165 ml/min/m2 during the 7-day study period. There were no differences in these responses between the colonized and the infected wounds. Pulmonary artery pressure increased from a mean baseline of 19 to 24 mm Hg and arterial oxygen tension (PaO2) decreased from a baseline of 90 to 80 mm Hg in the infected wound group, with values remaining at baseline in the colonized wound group. These changes corresponded with an increase in lymph and plasma TxB2 from a baseline of 200 to 210 pg/ml to 1000 +/- 250 and 600 +/- 190 pg/ml, respectively. Values in the animals with colonized wounds were not significantly increased.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Patterns of relapse in locally advanced head and neck cancer patients who achieved complete remission after combined modality therapy.

Relapse patterns in patients with locally advanced head and neck cancer who achieved complete remission were evaluated. After combined modality therapy with induction chemotherapy followed by surgery and/or radiotherapy, 71 of 103 patients were clinically free of disease. The 5-year recurrence rate was estimated at 51%, with a 39% local and 26% distant failure rate by 5 years. The factors significantly affecting the relapse patterns were: the site of the primary tumor (those with oral cavity lesions were more likely to fail locally, whereas hypopharynx patients had a higher risk of distant metastases); the type of definitive local treatment (those patients who received surgery and radiotherapy were at lower risk of pure local failure); TN Stage (patients with T4N3 or T3N3 tumor were at higher risk of both local and distant failure); and time to response and presence of oropharyngeal lesions (patients who had a longer period from diagnosis to final complete response [CR] and patients with oropharyngeal primaries were at higher risk for simultaneous local and distant failure). Type of chemotherapy, patient age, tumor differentiation, and response to induction chemotherapy did not significantly influence the patterns of relapse. A combined modality approach with induction chemotherapy, surgery, and/or radiotherapy does not seem to reduce the incidence of distant metastases significantly.

Adult↗
PubMed1985

Spontaneous remission of nephrotic syndrome in IgA glomerular disease.

We report two cases of adult onset nephrotic syndrome with pathologic features of minimal change disease but a predominance of IgA in mesangial regions. Both cases underwent spontaneous remission despite an episode of recurrent nephrotic syndrome in one patient. The relationship of the glomerular disease to minimal change and IgA nephritis is discussed.

Adult↗
PubMed1985

Determination of intracellular osmotic volume and sodium concentration in dunaliella.

A new method to measure intracellular volume in Dunaliella was developed, where lithium ions are used as monitors of the extracellular volume. Li(+) is shown to be impenetrable to the intracellular volume, insignificantly absorbed to the algae, and is rapidly and evenly distributed within the extracellular volume. The method is suggested to be free of several limitations and consistent errors present in several previously employed techniques.Using the new technique it is shown that both Dunaliella salina and Dunaliella bardawil adjust to a constant cellular volume when grown in a medium containing salt concentrations ranging from 0.5 molar to 4 molar NaCl. That volume is 90 femtoliter per cell for D. salina and 600 femtoliter per cell for D. bardawil. Nonosmotic volume accounts for about 10% of the total cell volume.The intracellular sodium concentration, as determined with the new technique, was under all experimental conditions tested below 100 millimolar. This was true both for cells grown on 0.5 to 4 molar NaCl, and during the osmoregulatory process. It is thus concluded that intracellular NaCl is a minor contributor to the overall intracellular osmotic pressure in Dunaliella.

Journal Article↗
PubMed1985

Effect of beta-adrenoceptor blockade on H+ and K+ flux in exercising humans.

The effect of beta-adrenoceptor blockade (beta B) on muscle release and uptake of H+ and K+ in humans during maximal exercise has been investigated. Eight volunteers cycled intermittently at power outputs corresponding to 100% of maximal O2 uptake. Prior to exercise either propranolol (beta B) or saline (control) was infused into the femoral vein. Arterial and femoral venous blood samples were drawn at rest, during exercise, and during 30-min recovery. Peak arterial blood values for K+, lactic acid (LA), and base deficit (BD) (mean +/- SE) were respectively 5.5 +/- 0.1, 9.5 +/- 0.6, and 11.7 +/- 0.9 mmol/l during beta B and 5.1 +/- 0.1, 8.3 +/- 0.6, and 10.3 +/- 1.0 for control (P less than 0.05). The release of K+ from the working leg did not differ between treatments during exercise, but K+ uptake during late recovery (5-30 min) was slightly lower during beta B. Thus the higher arterial K+ levels during exercise (beta B) cannot be attributed to greater release by active muscle but are likely due to decreased K+ uptake by noncontracting muscle. Arterial-femoral venous differences for LA and BD did not differ significantly between treatments. Additionally LA exchange across the leg was similar to H+ exchange (arterial-femoral venous differences for BD) under all conditions. During early recovery (1-5 min), regardless of experimental treatment, BD levels iin arterial blood were higher than LA (P less than 0.05). These elevated BD levels may be due to unequal removal rates between LA and H+ equivalents by nonexercised tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Determinants of risk for coronary artery bypass grafting in stable and unstable angina pectoris.

Although the operative risk and morbidity associated with coronary artery bypass grafting for chronic stable angina is exceptionally low, clinical and angiographic factors exist that may predict differing outcomes in patient subsets. Forty-five variables were prospectively recorded on all 1302 patients who underwent coronary artery bypass grafting at Toronto General Hospital over a 24-month period. Twelve selected variables were analysed by univariate and multivariate techniques. The patients were divided in two groups depending upon their clinical presentation (stable versus unstable angina) and the timing of surgery (elective versus urgent). The results of risk-factor analysis revealed that the unstable cohort had four predictors for operative mortality: sex, age, left ventricular function and left main coronary stenosis greater than 50%, whereas the stable cohort had only three predictors: sex, age and left ventricular function. The results for postoperative morbidity (perioperative myocardial infarction or low-output syndrome) showed that the unstable cohort had six predictors: sex, age, left ventricular function, timing of surgery, extent of coronary artery disease and the type of myocardial protection used. The stable cohort had only three predictors of morbidity, the same as for mortality. This analysis of multiple risk factors on patients grouped according to stability and timing of surgery clearly demonstrated determinants of risk in the two groups (operative mortality for the stable group of 2.9% versus 5.4% for the unstable group, and perioperative infarction rate for the stable group of 9.1% and for the unstable group of 13.7%).

Angina Pectoris↗
PubMed1985

Effect of fructose ingestion on muscle glycogen usage during exercise.

Eight healthy males were studied to compare the effects of preexercise fructose and glucose ingestion on muscle glycogen usage during exercise. Subjects performed three randomly assigned trials, each involving 30 min of cycling exercise at 75% VO2max. Forty-five min prior to commencing each trial, subjects ingested either 50 g of glucose (G), 50 g of fructose (F), or sweet placebo (C). No differences in VO2 or respiratory exchange ratio were observed between the trials. Blood glucose was elevated (P less than 0.05) as a result of the glucose feeding. With the onset of exercise, blood glucose declined rapidly during G, reaching a nadir of 3.18 +/- 0.15 (SE) mmol X 1(-1) at 20 min of exercise. This value was lower (P less than 0.05) than the corresponding values in F (3.79 +/- 0.20) and C (3.99 +/- 0.18). No differences in exercise blood glucose levels were observed between F and C. Muscle glycogen utilization was greater (P less than 0.05) during G (55.4 +/- 3.3 mmol X kg-1 w.w.) than C (42.8 +/- 4.2). No difference was observed between F (45.6 +/- 4.3) and C. There was a trend (P = 0.07) for muscle glycogen usage to be lower during F than G. These results suggest that the adverse effects of preexercise glucose ingestion are, in general, not observed with either fructose or sweet placebo.

Adult↗
PubMed1985

Lactose malabsorption in Israeli children.

Lactose malabsorption during childhood was studied in 110 Jewish children in Israel, using the lactose hydrogen breath test. Sixty-eight subjects (61.8%) were lactose malabsorbers, 41 (60.3%) of whom were lactose-intolerant with symptoms evidenced during or following the tests, whereas 27 (39.7%) were symptom-free (tolerant malabsorbers). In the youngest age-group (4 months to 3 years), no lactose malabsorption was detected, whereas in the higher age-groups the prevalence of lactose malabsorption increased with age. The percentages of lactose malabsorption in the age-groups 3 to 6, 6 to 12 and 12 to 16 years were 56.5, 65.2 and 75.0%, respectively. The percentages of lactose-intolerant subjects also increased in the same age-group, to 26.5, 39.1 and 65.0%. There were no significant differences in lactose malabsorption and tolerance between the various ethnic groups tested. The peak values of breath hydrogen were higher in lactose-intolerant than in lactose-tolerant malabsorbers.

Adolescent↗
PubMed1985

The role of the medical artist in maxillofacial prosthetics.

This paper describes a task analysis methodology for defining the role of medical artists as members of a maxillofacial team. On-the-job performances are identified, functionally analyzed and scaled to determine the level of complexity in relation to three dimensions: data, people, and things. Implications for professional role definition and curriculum development are discussed.

Humans↗