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Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 361 records · Page 20Linked to original sources
PubMed1983

Assessing self-maintenance: activities of daily living, mobility, and instrumental activities of daily living.

The aging of the population of the United States and a concern for the well-being of older people have hastened the emergence of measures of functional health. Among these, measures of basic activities of daily living, mobility, and instrumental activities of daily living have been particularly useful and are now widely available. Many are defined in similar terms and are built into available comprehensive instruments. Although studies of reliability and validity continue to be needed, especially of predictive validity, there is documented evidence that these measures of self-maintaining function can be reliably used in clinical evaluations as well as in program evaluations and in planning. Current scientific evidence indicates that evaluation by these measures helps to identify problems that require treatment or care. Such evaluation also produces useful information about prognosis and is important in monitoring the health and illness of elderly people.

Activities of Daily Living↗
PubMed1983

The effect of alloxan- and streptozotocin-induced diabetes on calcium transport in rat cardiac sarcoplasmic reticulum. The possible involvement of long chain acylcarnitines.

Isolated working hearts from diabetic rats have a decreased ability to respond to increasing preload or afterload. The ability of cardiac sarcoplasmic reticulum to transport Ca2+ was examined in diabetic rats. Hearts were obtained from female Wistar rats 120 days or 7 days after the induction of diabetes by a single I.V. injection of either alloxan (65 mg/kg) or streptozotocin (60 mg/kg). At all Ca2+ concentrations tested (0.2-5.0 microM free Ca2+) cardiac sarcoplasmic reticulum from 120-day diabetic rats showed a significant decrease in the rate of ATP-dependent tris-oxalate facilitated Ca2+ transport (62-73% of control). This was accompanied by a decrease in Ca2+ ATPase activity. The levels of long chain acylcarnitines associated with the microsomal sarcoplasmic reticulum preparation from 120-day diabetic rats were significantly higher than those present in sarcoplasmic reticulum from control rats. Palmitylcarnitine, the most abundant of the long chain acylcarnitines, in concentrations less than 7 microM was found to be a potent time-dependent inhibitor of Ca2+ transport in both control and diabetic rat sarcoplasmic reticulum preparations; inhibition of Ca2+ transport was found to be more marked in the control preparations. This would indicate that a degree of inhibition produced by the high endogenous levels of palmitylcarnitine may already be present in the diabetic rat preparations. Cardiac sarcoplasmic reticulum prepared from acutely diabetic rats (7 days) did not show any decrease in Ca2+ transport ability. Levels of long chain acylcarnitines associated with the microsomal preparation enriched in sarcoplasmic reticulum were also unchanged. These findings suggest that the alteration in heart function in 120-day diabetic rats may be due to the buildup of cellular long chain acylcarnitines which inhibit sarcoplasmic reticulum Ca2+ transport. The absence of any change in Ca2+-transport activity or levels of long chain acylcarnitines at 7 days suggests that the alterations seen in 120-day diabetic rats must be of gradual onset.

Animals↗
PubMed1983

Cardiac sarcoplasmic reticulum function in insulin- or carnitine-treated diabetic rats.

Cardiac sarcoplasmic reticulum (SR) function and SR levels of long-chain (LC) acylcarnitines were determined in streptozotocin-induced diabetic rats treated with insulin or D,L-carnitine. ATP-dependent calcium transport was significantly depressed in cardiac SR isolated from untreated diabetic rats compared with control rats. Diabetic rat cardiac SR levels of LC acylcarnitines were also significantly elevated. Various parameters of heart function (left ventricular developed pressure, +dP/dT, and -dP/dT), as determined on an isolated working heart apparatus, were found to be depressed in untreated diabetic rats. Cardiac SR isolated from diabetic rats treated throughout the study period with insulin or D,L-carnitine did not have elevated levels of LC acylcarnitines associated with SR membrane nor was SR calcium transport activity depressed. Heart function in the diabetic rats treated with insulin was similar to control rat hearts but heart function remained depressed in diabetic rats treated with D,L-carnitine. The data suggest that the LC acylcarnitines are involved in the observed impairment of cardiac SR function in diabetic rats. Other factors, however, must be contributing to the depression in heart function noted in these animals.

Animals↗
PubMed1983

Proliferative defects in ulcerative colitis patients.

The proliferative characteristics of epithelial cells in rectal biopsies from a group of 18 patients (ages 18-72) with ulcerative colitis spanning several months to over 20 years duration were examined, using an in vitro 3HTdR labeling technique. Although the labeling indices for patients with inflammatory bowel disease did not differ significantly from that of control (8.9 +/- 3.6 vs 7.7 +/- 3.9), the number of labeled cells/individual crypt column was higher among some crypts in ulcerative colitis patients. A normal proliferative pattern was demonstrated in crypts of 5/18 patients (27.8%) with DNA synthesis confined to the lower two-thirds of the crypt and the lower third the major zone of proliferation. Thirteen patients (72.2%) showed extension of the proliferative compartment to the surface of the glands, while retaining the lower third of the gland as the predominant proliferative zone (Stage I abnormality). Of these 13, seven had an additional abnormality, namely, a shift of the major zone of proliferation to the middle third of the crypt (Stage II abnormality), a pattern first reported in the colorectal mucosa of patients with a history of colon cancer. Precancerous lesions, including incompletely differentiated epithelium and lateral crypt budding, were recognized in all of these cases, suggesting that the Stage II abnormality is a proliferative parameter forecasting neoplastic transformation.

Adolescent↗
PubMed1983

[Autoimmunity factor in chronic gastritis: incidence of antiparietal cell antibodies and their relation to antral histology and basal blood gastrins].

In 118 patients with histological proven chronic gastritis, was performed a study of seric antibodies against parietal cells (ACCP), following the indirect inmuno-fluorescence method. The results were positives in 36 cases (30%). Four positives cases were found in 40 normal controls (10%), two of them were compensated diabetics, one have the thyrohyoid Hashimoto's disease, and the remainder, brother of a patient with chronic gastritis, was a positive ACCP. A major positiveness (44.4%) was obtained in 9 cases of gastric atrophy than in 65 cases with atrophic gastritis (32%) and in 44 cases of superficial gastritis (25%); although due to the few cases of gastric atrophy regarding other histological types, conclusions cannot be obtained about the incidence of ACCP and histological variety of chronic gastritis. If we do group the patients according to their acid secretory debit, 53 achlorhydric patients had a positiveness of ACCP of 45%, while over 63 with decreased secretory capability, only 18.4%, was positive. The distribution by age groups, shows a major incidence of ACCP about the 4th and 5th decade of life. Thirty seven patients with chronic atrophic gastritis and achlorhydria, and seven with chronic superficial gastritis and hypochlorhydria, besides the antibodies study were on a basal dosage of gastrinemia and antral endoscopic biopsy, finding out that, achlorhydric patients (15 on 19) with normal or slightly altered antrus, have gastrinemia (222 +/- 123 Pgo/oo) and the majority of patients with normal gastrinemia (32 +/- 16 pgo/oo) have more important antral lesions. The ratio between antral histology and ACCP in auto--immune gastritis (Type A), conciliates only partially with the observation by Strickland et al., as only 52.4% of achlorhydric patients and ACCP have a normal antrus or al least with mild lesions. Our results suggest the possibility of that on auto--immune gastritis could act other pathogenic factors of antral lesion.

Adult↗
PubMed1983

Recurrent free perforation in gastroduodenal Crohn's disease.

Three separate episodes of free perforation of the duodenum and stomach are described in a 47-year-old white man with histological evidence of gastroduodenal Crohn's disease, co-existing with peptic disease. His mother died of Crohn's disease after ostomy surgery and two brothers required ileostomy for inflammatory bowel disease. In 1972, the patient underwent a bypass gastroenterostomy for obstructing Crohn's disease of the descending duodenum. In 1977, 1978, and 1982, three free perforations occurred first in the duodenum and then twice at the gastrojejunostomy site. This occurred while on continuous Cimetidine therapy as well as steroids and after vagotomy. The basal and maximum acid outputs, secretin stimulation test, and serum gastrins were normal throughout his clinical course. This unique situation of acid peptic perforation in the presence of active Crohn's disease, poses an etiological dilemma and signals the vulnerability of the diseased stomach and duodenum in transmural disease.

Crohn Disease↗
PubMed1983

Assessment of colorectal cancer risk in patients with ulcerative colitis: experience from a private practice.

The cumulative risk of developing colon cancer in patients with ulcerative colitis has been stated to increase 10%-20% for every decade of duration of disease after 10 yr. We reviewed the clinical course of 673 patients with inflammatory bowel disease restricted to the colon who were seen by the authors since 1955. A subset of 258 patients with a diagnosis of ulcerative colitis established before 1970 and followed by the authors was studied by both the classical life table and a generalized approach to estimate the risk of colorectal carcinoma. Only nine instances of colorectal carcinoma occurred. Using the former method and eliminating 3 patients referred with known colorectal carcinoma, the actuarial risk for developing this complication for all patients, regardless of extent of disease, was computed to be only 6.6% at 26 yr and 11.4% at 32 yr following the onset of ulcerative colitis. The cumulative probability of colorectal carcinoma among patients with universal colitis at 26 yr was 19.7% by the generalized method and 11.6% using the standard life table. The generalized approach consistently gave higher risk estimates due to a smaller number of patients in the denominator of the risk calculation. Using an alternative method, we calculated cancer risk from the date first seen for patients with universal extent and a history of greater than or equal to 10 yr of disease (means = 17.4 yr). The magnitude of the resulting colorectal carcinoma risk was even less than previously reported in hospitalized patients. This method is more suited for colorectal carcinoma risk assessment of a large series of ulcerative colitis patients seen in private practice and the results should modify the fear of cancer development in these patients.

Actuarial Analysis↗
PubMed1982

Prevalence of antibodies to human cytomegalovirus in urban, kibbutz, and Bedouin children in southern Israel.

Prevalence of antibody to human cytomegalovirus (CMV) was determined in a sample of 860 healthy children aged 1-13 years in Beer Sheva, in the Negev region of Israel. Three groups of children were tested: (1) urban Jewish children of low, middle, and high socioeconomic levels; (2) 8 rural communes (kibbutz) in which children live in close contact with each other from the 6th week of life under good hygienic conditions and a high standard of living; (3) Bedouin, seminomadic Arabs living in relatively poor hygienic conditions in the desert. Kibbutz children showed a significantly higher rate of CMV seropositivity by the second year of life than urban Jewish and Bedouin children (76% versus 44% and 54% respectively) with a gradual increase to 94% in the 10-13-year age group. Among children living in urban populations a significantly higher prevalence of CMV seropositivity was associated with crowding, but not with other socioeconomic indicators (place of residence, country of origin, or education level of parents). A marked rise of CMV seropositivity with age was found in urban Jewish children in the 2-5-year age group during which time they attend nurseries (44% to 67%) and in the Bedouin children in the 6-9-year age group (59% to 86%) when they first attend school. The data suggest that close contact is of major importance in CMV infection in childhood. The clinical implications of early acquisition and high prevalence of CMV antibodies in the kibbutz setting are discussed.

Adolescent↗
PubMed1982

Assessment of fertility after testicular torsion: an experimental study.

The spermatic cord was ligated in Charles River adult rats producing viable reversible and non viable damaged testes. Weight of the rats, weight of the testes, weight of the epididymis, sperm motility, sperm concentration and fertility were the different parameters assessed. The results showed that there is a high percentage of subsequent atrophy in the ligated testes, and that there is a definite correlation between the length of the occlusion and the amount of testicular injury sustained. Leaving a ligated testis in situ for three months provoked a severe reduction in fertility and some lesser reduction in the sperm motility in the contralateral testis. This damage was not observed in the rats where the ligated testes were removed.

Animals↗
PubMed1982

Influence of selected fatty acids upon plaque formation and caries in the rat.

Weanling rats were given high-sucrose cariogenic diets containing 2 per cent lauric acid, linoleic acid, nonanoic acid or monolaurin. Plaque accumulation was determined on the incisors of half the animals during only the last 3 days of the study and on the remaining animals at the conclusion of a 21-day test period when both sulcal and smooth-surface caries were assessed. No significant differences between the test groups in food consumption were observed nor were there any differences in body weight gain. The least amount of plaque was observed in the animals given monolaurin; the other fatty acids exerted no significant effect upon plaque accumulation. The smooth-surface caries data indicated that the least number of lesions occurred in the animals on the diet containing monolaurin. Nonanoic acid was significantly more effective in limiting sulcal caries than any of the other fatty acids studied. Thus both monolaurin and nonanoic acid have significant cariostatic activity in the rat.

Animals↗
PubMed1982

Classification of somatic evoked potentials through maximum entropy spectral analysis.

Maximum entropy (ME) spectra are currently considered to be superior to spectra calculated by means of Fast Fourier Transforms (FFT) because the former offer higher resolution. However, in terms of classification of somatic evoked potentials (SEPs), FFT spectra are found to be better than ME spectra. An even better set of parameters for discriminating SEPs is the set of reflection coefficients derived in the process of calculating the ME spectra. They permit separation of SEPs obtained from monkeys with dorsal column lesion from SEPs obtained from normal monkeys, as well as distinguishing between SEPs obtained from large nerve fiber stimulation and SEPs from stimulation of all nerve fibers.

Animals↗
PubMed1982

Isolated colonic loop in the rabbit: an in vivo system for studying intestinal mucus.

A method for preparing an isolated colonic loop (Thiry-Vella) in a living rabbit is described. The loop, with its intact neurovascular supply, continues to secrete clear colonic mucus for more than 2 months. The chemical composition of the mucus, collected daily for 2 months, was analyzed and shown to be a high molecular weight glycoprotein composed of approximately equimolar amounts of protein and carbohydrate. The main sugars found were N-acetylgalactosamine, N-acetylglucosamine, galactose, and sialic acid. The most prominent amino acids were threonine, aspartic acid, glycine and serine. A considerable flattening and atrophy of the glandular structure of the isolated colonic loop was observed during the 2 months. This fact did not markedly affect the amount and chemical composition of the mucus that was collected daily from this loop. This model can be used in vivo to investigate colonic mucus in normal and diseased animals, or even following the administration of various drugs.

Animals↗