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Biomedical subjects

B Katz

Publications and source records attributed to B Katz.

At least 55 records · Page 3Linked to original sources
PubMed1998

Chronic exogenous hyperinsulinemia in pregnancy: a rat model of pregnancy-induced hypertension.

Insulin resistance and hyperinsulinemia are associated with essential hypertension. There is also evidence of hyperinsulinemia in women who developed hypertension in pregnancy (P). The present study examines whether chronic hyperinsulinemia in pregnant rats plays a role in the development of hypertension in pregnancy. A sustained-release insulin pellet was implanted subcutaneously in 15 Wistar rats (P-INS) 1 wk before and on day 7 of pregnancy; 14 control rats were sham-implanted (P-SHAM). Tail-cuff systolic BP (SBP), serum triglycerides, glucose, insulin, renal function, and urinary excretion of Na+ and of metabolites of nitric oxide were determined throughout pregnancy. Data were analyzed by ANOVA with basal body weight as covariate analysis of covariance. Results are expressed as the mean +/- SD. Body weight; water and food intake; urine volume; creatinine clearance; and level of proteinuria at the end of pregnancy were similar in both groups. The number of fetuses was 9 +/- 2.3 in P-INS versus 11 +/- 2.4 in pregnant control rats (P < 0.05). Before mating, SBP was similar, but at the end of pregnancy SBP was 110 +/- 18 mmHg in P-INS versus 85 +/- 12 mmHg in pregnant rats (P < 0.05). Serum triglycerides and Na+ were also higher in P-INS rats. The fractional excretion of Na+ was 3.1 +/- 1.0 versus 4.4 +/- 1.5, respectively (P < 0.01). The percent increase in nitric oxide metabolite excretion was 233 +/- 14 versus 370 +/- 17%, respectively (P < 0.01). Chronic hyperinsulinemia, without sugar supplementation, and hypertriglyceridemia may cause a decrease in the synthesis of nitric oxide in P-INS rats. The development of hypertension in these rats may be associated with an impaired vasodilatation, together with an increased renal sodium reabsorption.

Animals↗
PubMed1998

Health-related quality of life after knee replacement.

A cross-sectional, community-based survey of a random sample of 1750 of 242,311 Medicare recipients was performed. The patients were at least sixty-five years old and had had a primary or revision knee replacement (either unilaterally or bilaterally) between 1985 and 1989. Three samples were surveyed separately: a national sample (to reflect the United States as a whole) and samples from Indiana and the western part of Pennsylvania (sites chosen for convenience to assess the validity of the findings for the national sample on a regional level). Each sample was stratified by race, age, residence (urban or rural), and the year of the procedure. Valid and reliable questionnaires were used to elicit the participants' assessments of pain, physical function, and satisfaction two to seven years after the knee replacement. Of the 1486 patients who were eligible for inclusion in the survey, 1193 (80.3 per cent) responded. The mean age of the respondents was 72.6 years. Eight hundred and forty-nine respondents (71.2 per cent) were white, and 849 (71.2 per cent) were women. The participants reported that they had little or no pain in the knee at the time of the survey, regardless of the age at the time of the knee replacement, the body-mass index, or the length of time since the knee replacement. After adjustment for potential confounding variables, predictors of better physical function after the replacement were an absence of problems with the contralateral knee, primary knee replacement (rather than revision) (Indiana sample only), and a lower body-mass index (Indiana and western Pennsylvania samples). Four hundred and fifteen (85.2 per cent) of the 487 patients in the national sample were satisfied with the result of the knee replacement. In what we believe to be the first community-based study of the outcome of knee replacement, patients reported having significant (p = 0.0001) and persistent relief of pain, improved physical function, and satisfaction with the result two to seven years postoperatively. The findings of the present study suggest that age and obesity do not have a negative impact on patient-relevant outcomes (pain and physical function). Dissemination of these findings has the potential to increase appropriate referrals for knee replacement and thereby reduce the pain and functional disability due to osteoarthrosis of the knee.

Aged↗
PubMed1998

Detection of germ cell tumor cells in apheresis products using polymerase chain reaction.

The contamination of apheresis products with tumor cells was evaluated in patients undergoing autologous peripheral blood stem cell transplantation for germ cell tumors. A blinded, retrospective analysis was performed on 63 apheresis products from 28 patients using the PCR and primers for beta human chorionic gonadotropin (beta-HCG). Of the 20 patients with beta-HCG-secreting tumors, 8 apheresis products from 7 patients were PCR positive. PCR was negative in the 8 patients whose tumors did not secrete beta-HCG. Twenty-two apheresis products from patients with lymphoma and breast cancer were negative for beta-HCG expression. Evaluating the 20 patients with beta-HCG-secreting tumors, 100% of PCR-positive patients had elevated serum beta-HCG at the time of apheresis compared to 46.2% of PCR-negative patients (P = 0.04). A positive PCR was also associated with a higher serum beta-HCG at diagnosis (P = 0.03). Patients receiving a PCR-positive product had a higher relapse rate (85.7 versus 61.5%) and were more likely to have visceral metastasis (100 versus 61.5%), although the numbers did not reach statistical significance (P = 0.35 and 0.11, respectively). The finding of beta-HCG mRNA in apheresis products strongly suggests the presence of circulating tumor cells in a significant number of germ cell patients undergoing autologous transplantation. This assay may be useful in monitoring attempts at tumor cell depletion and in developing improved prognostic models for assessing risk of relapse after transplantation.

Blood Component Removal↗
PubMed1998

Gastroesophageal reflux in adults. Where are we now?

BACKGROUND: Gastroesophageal reflux is a common form of dyspepsia affecting 20-40% of the population. OBJECTIVE: Adults experiencing gastroesophageal reflux represent a challenging subgroup of patients presenting to primary care physicians. Identification of those patients who require medical therapy and ultimately surgery, requires an understanding of the mechanisms of disease, the available diagnostic tools as well as the array of acid suppressive agents currently in use. DISCUSSION: Successful therapy of gastroesophageal reflux may reduce complicated oesophageal and extraoesophageal disease.

Adult↗
PubMed1997

Home health nurses: stress, self-esteem, social intimacy, and job satisfaction.

A survey of 253 home health care nurses' perceptions of work-related stress, self-esteem, social intimacy, and job satisfaction found that stress has a negative correlation with self-esteem, social intimacy, and job satisfaction. A positive correlation, however, was found between self-esteem and social intimacy and job satisfaction. Health system administrators, owners, and directors had significantly higher levels of self-esteem, nurses with 5 years or more in their home health nursing position had significantly higher levels of self-esteem. The survey found that nurses with less than a baccalaureate degree possessed significantly lower levels of sociability than those with a graduate or baccalaureate degree. Administrators and managers scored significantly higher on sociability than head nurses.

Adult↗
PubMed1997

Pregnancy-induced hypertension in rats with adriamycin nephropathy is associated with an inadequate production of nitric oxide.

Hypertensive complications are relatively common in pregnancy, particularly in the presence of preexisting renal disease. Although the pathogenesis of such complications is still unknown, recent animal studies have suggested that it may be related to impaired synthesis of nitric oxide (NO). Rats with adriamycin nephropathy develop a "preeclamptic-type" pregnant state characterized by elevated blood pressure, lack of hyperfiltration, and enhanced proteinuria. Preliminary studies with this model have implicated inadequate NO synthesis in the development of preeclamptic-like pregnancy. The aim of the present study was to confirm this hypothesis. Pregnant rats, both normal (PREG) and those with adriamycin nephropathy (AN-PREG), received 100 mg/L N omega-nitro-L-arginine methyl ester PO from the middle of gestation to term (day 11, term approximately 22 days). One group of AN-PREG rats received either L-arginine or D-arginine (2 g/L) from midpregnancy. At term, systolic pressure, mean arterial pressure, urinary metabolites of NO, creatinine clearance, and urinary protein were assessed. At term, compared with virgin rats with adriamycin nephropathy, untreated AN-PREG rats had increased systolic pressure, mean arterial pressure, and proteinuria (mean arterial pressure, 124 +/- 2.5 versus 99.7 +/- 1.6 mm Hg [P < .05]; proteinuria, 434 +/- 58 versus 216 +/- 63 mg/d [P < .05]). Creatinine clearance did not change (1.68 +/- 0.23 versus 1.35 +/- 0.09 mL/min, P = NS). In PREG rats, urinary metabolites of NO increased approximately threefold at term pregnancy compared with control. By contrast, in AN-PREG rats, excretion of urinary metabolites of NO increased only by approximately 1.7-fold (P < .01) versus PREG rats. With the exception of AN-PREG rats, inhibition of NO synthesis with N omega-nitro-L-arginine methyl ester enhanced blood pressure and decreased creatinine clearance but did not influence proteinuria. Excretion of urinary metabolites of NO was similarly inhibited in all rats. In AN-PREG rats, L-arginine normalized blood pressure (91 +/- 2.15 mm Hg) and lowered proteinuria partially but significantly. D-Arginine had no effect. In summary, AN-PREG rats are unable to adequately increase NO synthesis when physiologically required. Correction of this deficit by L-arginine treatment induced a significant clinical improvement.

Animals↗
PubMed1997

Acute human trial of the floating mass transducer.

Five patients underwent acute implantation of the Floating Mass Transducer (FMT) to evaluate the ability of the FMT to produce measurable auditory thresholds when temporarily placed in the middle ears of patients undergoing routine stapedotomy procedures. The FMT was placed on the long process of the incus in an inferior position, as is planned for clinical application, and in two additional positions. The ability of the FMT to produce measurable auditory thresholds was demonstrated in all patients. Results were affected by the lack of a healing period, the presence of a fixed stapes and an open middle ear space, and patient sedation.

Audiometry↗
PubMed1996

Normal appearance and size of the diaphragmatic crura in children: CT evaluation.

PURPOSE: The objectives of the study were to document the normal CT appearance and size of the crura of the diaphragm in children. MATERIALS AND METHODS: The CT scans of 80 children (0-15 years) were reviewed. The children were divided into eight age groups. The maximal transverse diameters of the right and left crura were measured. They were normalized by comparison with the transverse and anterior-posterior diameters of the 12th thoracic vertebra (T12) and the transverse abdominal diameter at T12. The crura were also evaluated as to whether their contour was smooth or nodular. RESULTS: The diaphragmatic crura of smaller children appear large, relative to body size and the diameters of the T12 vertebral body, compared with those in older children. Crural width does not increase significantly with age. Additionally, the crura were found to have a greater tendency to be nodular in appearance in children under the age of 5 years than in older children. CONCLUSION: Diaphragmatic crura are more nodular and larger relative to body size in younger children.

Abdomen↗
PubMed1996

Home health nurses: stress, self-esteem, social intimacy, and job satisfaction.

A survey of 67 home healthcare nurses' perception of work-related stress, self-esteem, social intimacy, and job satisfaction during corporate merging compared with a prior study of acute care surgical nurses (n = 71) during a merger of two hospitals found no difference between stress levels of home health nurses compared with acute care surgical nurses, which is contrary to popular belief.

Adult↗
PubMed1996

Migraine.

Current research has focused on several aspects of migraine. Epidemiologic studies have described the general health characteristics of migraineurs. Case reports of unusual manifestations of migraine abound, and advances in the application of neurologic imaging offer the promise of prompt, efficient diagnosis of unusual vascular headaches. Investigations into physiologic and biochemical parameters of migraine continue to advance theories of pathogenesis. Finally, as a wide range of therapeutic modalities continue to be used in these diseases, the efficacy, complications, and relative costs of different therapies are discussed.

Combined Modality Therapy↗
PubMed1996

Coping with downsizing: stress, self-esteem and social intimacy.

As health care system continue to downsize, nurses will experience organizational changes, change in positions or sudden terminations. Acute care surgical nurses were surveyed to determine their perceptions of work-related stress, self-esteem and social intimacy during downsizing.

Adaptation, Psychological↗
PubMed1996

Multidisciplinary pain clinics for older people. Do they have a role?

Chronic pain occurs frequently in older people but is rarely considered a problem which warrants specialized attention by physicians or specialists in pain management. However a small proportion of older people with significant psychologic and physical disability from pain fail to respond to conservative management strategies. In this article, the authors describe the operations of a successful multidisciplinary pain management center for older people and briefly outline outcomes according to measures of pain, mood, and activity. Other factors that are specific and important to the management of chronic pain in older patients are discussed also. Despite some disadvantages, it is concluded that there is a place for multidisciplinary pain clinics for older people.

Aged↗
PubMed1995

Controlled-release drug delivery systems in cardiovascular medicine.

Controlled-release drug delivery technology has had a significant effect on the pharmacotherapy of cardiovascular diseases. Oral and transcutaneous controlled-release systems allow relatively short-acting drugs to be administered once or twice daily with comparable therapeutic efficacy and fewer adverse reactions compared with standard formulations. They can provide decreased fluctuations in drug concentrations in plasma while possibly reducing the total amount of drug necessary for a clinical response. Techniques include the diffusion, bioerosion or degradation, and generation of osmotic pressure in orally active and transcutaneous drug delivery systems. Calcium-channel blocking agents, nitrates, beta-blocking agents, antiarrhythmic agents, clonidine, and nicotinic acid can be administered by these techniques, which have greatly influenced the application of these drugs in clinical practice.

Administration, Cutaneous↗