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Biomedical subjects

A Katz

Publications and source records attributed to A Katz.

At least 415 records · Page 23Linked to original sources
PubMed1984

Effect of high intensity interval training on 2,3-diphosphoglycerate at rest and after maximal exercise.

The purpose of this study was to examine the effect of intense interval training on erythrocyte 2,3-diphosphoglycerate (2,3-DPG) levels at rest and after maximal exercise. Eight normal men, mean +/- SE = 24.2 +/- 4.3 years, trained 4 days X week-1 for a period of 8 weeks. Each training session consisted of eight maximal 30-s rides on a cycle ergometer, with 4 min active rest between rides . Prior to and after training the subjects performed a maximal 45-s ride on an isokinetic cycle ergometer at 90 rev X min-1 and a graded leg exercise test ( GLET ) to exhaustion on a cycle ergometer. Blood samples were obtained from an antecubital vein before, during and after the GLET only. Training elicited significant increases in the amount of work done during the 45-s ride (P less than 0.05), and also in maximal oxygen uptake (VO2 max: Pre = 4.01 +/- 0.13; Post = 4.29 +/- 0.07 1 X min-1; P less than 0.05) during exercise and total recovery VO2 (Pre = 19.14 +/- 0.09; Post = 21.45 +/- 0.10 1 X 30 min-1; P less than 0.05) after the GLET . After training blood lactate was higher, base excess lower and pH lower during and following the GLET (P less than 0.05 for all variables).(ABSTRACT TRUNCATED AT 250 WORDS)

2,3-Diphosphoglycerate↗
PubMed1984

Maximal exercise tolerance after induced alkalosis.

Eight healthy males performed two rides to exhaustion at a work load corresponding to 125 VO2 max, 1 h after ingesting either 0.2 g NaHCO3/kg body weight (E) or NaCl (C). Mean +/- SE pre-exercise blood pH, HCO-3, and base excess (BE) values were respectively 7.42 +/- 0.01, 28.2 +/- 1.5 mmol/l, and 2.02 +/- 0.10 mmol/l for the E condition, and 7.39 +/- 0.01, 24.4 +/- 0.07 mmol/l, and -0.40 +/- 0.07 mmol/l for the C condition (P less than 0.05 for all variables). Cycling time to exhaustion (E = 100.6 +/- 6.1; C = 98.6 +/- 5.7 s) and total VO2 during recovery (E = 17.7 +/- 0.9; C = 17.3 +/- 0.8 1/30 min) did not differ significantly between treatments. Blood pH, HCO-3, and BE were significantly higher while the hydrogen ion to lactate ratio (nmol/mmol) was significantly lower in E than in C during recovery. Blood LA levels were also greater in E than in C during the latter part of recovery although peak individual values were not significantly different between trials (E = 14.4 +/- 0.4; C = 13.3 +/- 0.0 mmol/l). In view of the insignificant differences in cycling time, peak individual LA, and total recovery VO2, it is not likely that LA production was greater in E than in C. Rather it appears that LA efflux was enhanced by the NaHCO3 feeding. Additionally, the return of the acid-base status in blood to resting conditions was more rapid during alkalosis. Given this protocol, alkalosis does not help to sustain an intense exercise bout. These data suggest, however, that NaHCO3 may be of benefit following repeated work bouts.

Bicarbonates↗
PubMed1984

Oxygen tension in antecubital blood of trained and untrained males after maximal leg exercise.

This study compared oxygen tension (pO2) and percent oxygen saturation (SO2) in antecubital venous blood of six untrained (UT) and six endurance trained (ET) males during and following a graded leg exercise test to exhaustion on a cycle ergometer. Mean (+/- SE) resting values for pO2 were 29.3 (+/- 2.3) and 30.3 (+/- 2.0) mmHg, and SO2 were 51.8 (+/- 5.2) and 54.9 (+/- 4.6)% for the ET and UT men, respectively. At exhaustion pO2 decreased to 23.0 (+/- 4.5) and 23.3 (+/- 4.7) mmHg, while SO2 decreased to 29.6 (+/- 9.7) and 31.3 (+/- 9.7)% for the ET and UT subjects, respectively. There were no significant differences between the two groups in either pO2 or SO2 at rest or during exercise. However, there were marked increases in pO2 and SO2 during the 5 min recovery period for both groups. The ET cyclists demonstrated significantly higher pO2 and SO2 levels than the UT group at each min of recovery; e.g., at 4 min postexercise pO2 was 72 and 49 mmHg for the ET and UT men, respectively (p less than 0.05). The general rise in pO2 and SO2 for both groups was attributed to an increased arterialization of the antecubital venous blood while postexercise hyperventilation may have also elevated pO2 values. The higher values for the ET subjects during recovery were explained by a lower peripheral sympathetic tone and a presumably greater cardiac output at exhaustion for the ET group than the UT group, which may have allowed a relatively greater distribution of arterialized blood to the periphery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Sialadenitis following I-131 therapy for thyroid carcinoma: concise communication.

During a 4-yr period, ten of 87 patients (11.5%) who received therapeutic doses of radioactive iodine (I-131) for thyroid carcinoma developed acute and/or chronic sialadenitis involving the parotid (five patients) or submandibular (four patients) glands, or both (one patient). Nine of the 10 patients had received prior I-131 therapy; the precipitating I-131 dose varied between 10 and 164 mCi. Onset of symptoms occurred between 1 day and 6 mo following therapy and the duration varied from 3 wk to 21/2 yr. This complication occurs more often than has been appreciated.

Adenocarcinoma↗
PubMed1983

Infantile myofibromatosis--a solitary lesion. A case report.

Infantile myofibromatosis (IM) usually manifests itself within the first 6 months of life, and is frequently present at birth. The hard, rubbery nodules may be either solitary or multiple. Solitary lesions are more common and have a marked tendency to occur in boys, while the less common multicentric disorder predominantly affects girls. Solitary nodules are usually located in the deep soft tissues, involving skeletal muscle, and usually occur in the head and neck region or trunk. The prognosis of the solitary type of lesion is excellent, the recurrence rate being very low, and distinction from the other fibromatoses of infancy is important. A case of solitary infantile myofibromatosis occurring as a congenital lesion of the back in a female infant is described.

Female↗
PubMed1983

Efficacy of apical seal of Engine Plugger condensed root canal fillings--leakage to dyes.

A new rotatory instrument, the Engine Plugger, that is claimed to be less fragile than the McSpadden Compactor, has been introduced since the recognition of thermomechanical compaction as a valid technique for root canal filling. The purpose of this study was to test the efficacy of the apical seal afforded by the Engine Plugger in comparison with that of an established technique, lateral condensation. Eighty roots with round canals prepared to size 45 were randomly divided into two groups: one compacted with the Engine Plugger (Group 1) and the other with the lateral condensation technique (Group 2). AH-26 sealer was used in half the specimens. Four additional roots served as controls. The roots were cleared following immersion in Procion brilliant green, and the maximal depth of penetration of the dye was measured with a stereomicroscope. Severe leakage occurred in both groups when sealer was not used (mean depth: 3.17 mm in Group 1; 4.3 mm in Group 2). Addition of sealer reduced leakage significantly (p less than 0.001). There was no statistically significant difference in the depth of penetration of the dye between the two groups when AH-26 was used, although a trend in favor of the Engine Plugger method (0.15 mm versus 0.425 mm for lateral condensation) was noted.

Coloring Agents↗
PubMed1983

Leg muscle pH following sprint running.

In an effort to compare the disturbances in leg muscle pH during sprint running, muscle biopsies were obtained from the gastrocnemius and vastus lateralis muscles of six healthy men (three endurance-trained and three nonendurance-trained) before and after a treadmill sprint run (TSR) to fatigue (54-105 s) at roughly 125% of their aerobic capacities. Following the TSR, repeated blood samples were taken from a hand vein and later analyzed for pH, PCO2, and lactic acid (HLa). The muscle specimens were analyzed in duplicate for pH and HLa. Resting-muscle pH was 7.03 +/- 0.02 (means +/- SE) and 7.04 +/- 0.01 for the gastrocnemius and vastus lateralis muscles, respectively. At the termination of the TSR, the pH in these muscles was 6.88 +/- 0.05 and 6.86 +/- 0.03, respectively. After a 400-m timed run on the track, the pH in the gastrocnemius of four of the subjects averaged 6.63 +/- 0.03, while blood pH and HLa were 7.10 +/- 0.03 and 12.3 mM, respectively. Although no differences in pH and HLa were observed between the vastus lateralis and gastrocnemius muscles at the end of the treadmill trial, it is speculated that the lesser disturbance in acid-base balance seen in endurance performers may have been due to a lesser production of metabolites in their running musculature when compared to nonendurance performers.

Adult↗
PubMed1983

Variation in antigenic determinants of p53 transformation-related protein obtained from various species.

p53 is a cellular-encoded transformation-related protein. It is synthesized at elevated levels in tumor cells but has also been detected at low concentrations in several types of nontransformed cells. The p53 of tumor cells is immunogenic and elicits specific antibody production. The antigenic determinants of the p53 protein were studied by specific binding to anti-p53 monoclonal antibodies obtained from the RA3-2C2, PAb122, and PAb421 established hybridoma cell lines, and their conservation was followed in various animal species. We found that whereas mouse p53 efficiently immunoprecipitated with all three anti-p53 monoclonal antibodies, human and rat p53 bound PAb122 and PAb421 but lacked a determinant binding RA3-2C2. The hamster p53 molecule represented a third category, which immunoprecipitated with polyclonal anti-p53 antibodies but failed to bind all three monoclonal antibodies analyzed here. Using these monoclonal antibodies, we detected no variations between p53 found in transformed and p53 found in nontransformed cells, within a given species. The results also showed that RA3-2C2, which recognizes a mouse-specific determinant, binds a site located at a proteolytic digestion fragment of the p53 molecule that differs from that containing PAb122 and PAb421 recognition site(s). p53 is a single protein that can be immunoprecipitated through different antigenic determinants that vary between species.

Animals↗
PubMed1983

IgA nephritis with nephrotic range proteinuria.

Nephrotic range proteinuria is uncommon in patients with IgA nephritis. For this reason we compared the clinical and pathologic features in 63 non-nephrotic patients with those in 8 patients who had nephrotic range proteinuria at the time of biopsy. Both the mean age and the mean duration of the disease at the time of diagnosis were not significantly different in the 2 groups of cases. Significant associations were found between nephrotic range proteinuria and the following: the extent of glomerular hyalinization, the severity of interstitial fibrosis and tubular atrophy and the degree of foot process effacement and mesangial matrix increase. A significant association was also noted with nephrotic range proteinuria had elevated levels of serum creatinine on follow-up compared with 20% of non-nephrotic cases. The results of our study suggest that patients with nephrotic range proteinuria have a more severe type of IgA nephritis from the outset and that a marked degree of proteinuria is not merely a consequence of the duration of disease.

Adult↗
PubMed1983

Estimation of polymeric IgA in human serum: an assay based on binding of radiolabeled human secretory component with applications in the study of IgA nephropathy, IgA monoclonal gammopathy, and liver disease.

Binding of 125I-human secretory component (SC) to human polymeric immunoglobulin A (pIgA) was employed to measure quantitatively the pIgA present in human sera. Interference by IgM in some sera was prevented by removal of IgM with glutaraldehyde polymerized anti-IgM antibodies. 125I-SC complexed to pIgA was measured by precipitation with anti-IgA antibodies and the quantity of pIgA in human serum was estimated by comparing the quantity of 125I-SC bound by several dilutions of human serum to that bound by standard quantities of human monoclonal pIgA proteins. The assay was specific for pIgA because heat-aggregated monomeric IgA or hypogammaglobulinemic serum did not bind 125I-SC greater than a precipitate formed with human monoclonal IgG and anti-IgG. Moreover, analysis of a series of IgA myeloma sera indicated no correlation between the IgA content of the serum and the quantity of pIgA measured. The quantity of pIgA found in 30 normal human sera was 0.13 +/- 0.08 mg/ml (1S.D.), which consisted of 11.3 +/- 5.3% (1 SD) of the total IgA. Patients with IgA monoclonal gammopathy were most often found to have predominantly monomeric IgA. Patients with IgA nephropathy also showed an elevation of pIgA, but this appeared to be a consequence of an overt IgA elevation. IgA nephropathy patients with elevated serum IgA in fact showed a significant elevation of monomeric IgA. Selective elevation of pIgA was observed in patients with primary biliary cirrhosis and alcoholic liver disease. A comparison of this assay with other assays to measure pIgA is discussed.

Aged↗