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Biomedical subjects

J Katz

Publications and source records attributed to J Katz.

At least 91 records · Page 5Linked to original sources
PubMed2000

Density dependent regulation of human Schwann cell proliferation.

Cessation of division is prerequisite for Schwann cell differentiation but regulation of this critical function is poorly understood. Heregulin/forskolin-induced growth of human Schwann cells (HSCs) in vitro was found to be strongly regulated by cell density and thus could model some aspects of negative growth-regulation in vivo. To better understand this phenomenon, the production of an autocrine growth-inhibitor and the role of contact-inhibition were investigated. The possible involvement of two membrane proteins, contactinhibin (CI) and peripheral myelin protein 22 (PMP22) in regulating growth was studied. Thymidine-labeling of HSCs on collagen-coated dishes was inhibited at cell densities less than one tenth of the density at maximal growth-inhibition. Medium from high density cultures did not inhibit the thymidine-labeling of HSCs at low density, a result that argues against the production of a soluble inhibitor. The expression of CI and PMP22 in nerve and HSCs, and the effect of a function-blocking antibody to CI on HSC growth, were determined. CI was detected in fresh nerve by western blotting, and could easily be detected by immunocytochemistry in cultured HSCs by five days and for several weeks thereafter. Twenty-four hour treatment with anti-CI antibody did not increase the thymidine-labeling of HSCs at any density but a significant increase in HSC number was observed in cultures treated with anti-CI for 20 days. This increase was not related to decreased cell death. PMP22, unlike other myelin proteins, was not down-regulated after nerve dissociation and by seven days nearly all HSCs were PMP22 positive. These results provide evidence for a contact-mediated mechanism of growth-regulation in HSCs and suggest that CI is involved in this mechanism.

Adolescent↗
PubMed2000

Avian influenza viruses infecting humans.

Avian species, particularly waterfowl, are the natural hosts of influenza A viruses. Influenza viruses bearing each of the 15 hemagglutinin and nine neuraminidase subtypes infect birds and serve as a reservoir from which influenza viruses or genes are introduced into the human population. Viruses with novel hemagglutinin genes derived from avian influenza viruses, with or without other accompanying avian influenza virus genes, have the potential for pandemic spread when the human population lacks protective immunity against the new hemagglutinin. Avian influenza viruses were thought to be limited in their ability to directly infect humans until 1997, when 18 human infections with avian influenza H5N1 viruses occurred in Hong Kong. In 1999, two human infections with avian influenza H9N2 viruses were also identified in Hong Kong. These events established that avian viruses could infect humans without acquiring human influenza genes by reassortment in an intermediate host and highlighted challenges associated with the detection of human immune responses to avian influenza viruses and the development of appropriate vaccines.

Animals↗
PubMed2000

The effects of type of surgery and time on psychological adjustment in women after breast cancer treatment.

BACKGROUND: The aim of the present study was to examine whether type of surgery, age, and time since surgery influenced psychological distress and quality of life (QOL) in women treated for breast cancer. METHODS: We surveyed 183 women who had undergone surgery for breast cancer. Psychological distress was measured with the Mental Health Inventory and QOL was measured with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. RESULTS: After controlling for stage of disease, radiation treatment, and age, there was a statistically significant interaction between type of surgery and time since surgery for the Mental Health Inventory total score, and a marginal interaction between type of surgery and time since surgery for the Global health status/QOL score. Women who had breast conservation surgery experienced significantly greater levels of psychological distress and marginally worse QOL from 40 months after surgery onward than did women who received a mastectomy. CONCLUSIONS: The effects of different surgical treatments for breast cancer on psychological distress and QOL become apparent only after a period of several years. Women, therefore, need counseling on the potentially positive and negative psychological implications of different surgical treatments for breast cancer.

Adult↗
PubMed2000

Injectable versus topical anesthesia for cataract surgery: patient perceptions of pain and side effects. The Study of Medical Testing for Cataract Surgery study team.

OBJECTIVE: To compare patient reports of intraoperative pain and postoperative side effects by different anesthesia strategies for cataract surgery. DESIGN: Prospective cohort study. PARTICIPANTS: Men and women 50 years of age and older undergoing 19,250 cataract surgeries at nine centers in the United States and Canada from June 1995 through June 1997. INTERVENTION: Topical anesthesia or anesthesia with injection, with or without sedatives, opioid analgesia, hypnotics, and diphenhydramine (Benadryl). MAIN OUTCOME MEASURES: Patient ratings of intraoperative pain, satisfaction with pain management, and early postoperative side effects (drowsiness, nausea, vomiting, or a combination thereof). RESULTS: Twenty-six percent of surgeries were performed using topical anesthesia alone, and the remainder were performed with peribulbar, retrobulbar, or facial nerve block, or a combination thereof. Local anesthesia by injection with sedatives and diphenhydramine resulted in the lowest reporting of any intraoperative pain (1.3%), with postoperative drowsiness (9.6%) and nausea, vomiting, or both (1.5%) comparable with those administered topical anesthesia alone. Among those receiving topical anesthesia, use of sedatives and opioids reduced reports of any pain during surgery by 56% (95% confidence interval [CI], 34%, 70%), but increased nausea and vomiting (odds ratio, 2.27; 95% CI, 1.26, 4.09) compared with those administered topical anesthesia alone, after adjusting for age, gender, race, American Society of Anesthesiologists risk class, self-reported health status, and duration of surgery. Among those receiving local injections, use of opioids reduced reports of any pain among those receiving sedatives by 37% (95% CI, 15%, 54%), but did not increase postoperative side effects. The use of diphenhydramine among those receiving sedatives decreased reports of any pain by 59% (95% CI, 33%, 75%) and also reduced drowsiness and nausea and vomiting by 57% (95% CI, 48%, 65%) and by 60% (95% CI, 36%, 75%), respectively. Use of hypnotics with sedatives was associated with increased reports of any pain during surgery and increased nausea and vomiting after surgery. CONCLUSIONS: Patient reports of any pain during cataract surgery (5%) and postoperative side effects (16% drowsiness and 4% nausea and vomiting) were low, but varied by anesthesia strategy. Patient perceptions of pain and side effects can be helpful in guiding the appropriate choice of anesthesia strategy.

Administration, Topical↗
PubMed2000

Differences in quality of life across renal replacement therapies: a meta-analytic comparison.

A meta-analysis compared emotional distress and psychological well-being across renal replacement therapies (RRTs) and examined whether differences could be explained by: (1) treatment modalities, (2) case mix, or (3) methodologic rigor. Standard meta-analytic procedures were used to evaluate published comparative studies. Successful renal transplantation was associated with: (1) lower distress (effect size, d = -0.43 SD) and greater well-being (d = 0. 62 SD) than in-center hemodialysis (CHD) and (2) lower distress (d = -0.29 SD) and greater well-being (d = 0.53 SD) than continuous ambulatory peritoneal dialysis (CAPD). CAPD was characterized by greater well-being (d = 0.18 SD) than CHD and CHD was associated with greater distress (d = 0.16 SD) than home hemodialysis. Although methodologic rigor and case-mix differences did not correlate with the magnitude of psychosocial differences across RRTs, 10 of the 12 comparisons (83%) were threatened by publication bias (ie, that nonsignificant comparisons may have been underrepresented in the published literature). Thus, although significant quality-of-life differences were evident across treatment groups, the types of patients representative of the various RRTs also differed significantly in terms of case-mix variables relevant to psychosocial well-being and emotional distress. Published findings indicating differential quality of life across RRTs may thus be attributable to: (1) valid differences in effective renal replacement, reduced medical complications, and lifestyles afforded by these treatment modalities; (2) case-mix differences in the patient samples selected to represent them in research comparisons; or (3) both of these alternative explanations.

Adolescent↗
PubMed2000

Cytokine profiles in parotid saliva from HIV-1-infected individuals: changes associated with opportunistic infections in the oral cavity.

The purpose of this study was to quantitate levels of cytokines in parotid saliva of subjects infected with human immunodeficiency virus-1 (HIV-1) and to determine if the cytokine profiles differ in subjects with an oral opportunistic infection, i.e., candidiasis or oral hairy leukoplakia. Parotid saliva samples were obtained from HIV-infected individuals with or without candidiasis or oral hairy leukoplakia and from healthy controls and were assessed by ELISA for levels of interleukin (IL)-1, IL-2, IL-4, IL-5, IL-10, transforming growth factor-beta, tumor necrosis factor-alpha and interferon (IFN)-gamma. Saliva from HIV-infected subjects with oral candidiasis had significantly higher levels of IFN-gamma than that seen in HIV-infected individuals with no oral disease and significantly higher levels of IL-2, IL-5 and IFN-gamma than saliva of healthy controls. No significant difference was seen in cytokine levels in saliva from HIV-infected subjects with no oral infections and healthy controls. The HIV-infected subjects with oral hairy leukoplakia displayed significantly higher levels of both IL-1 alpha and IFN-gamma compared with the HIV and no oral disease group and a higher level of IFN-gamma than seen in saliva from the healthy control group. In comparing cytokine levels from both HIV and oral disease groups, significant differences were detected in levels of IL-5 and IL-10. These results indicate that the profile of salivary cytokines is altered as a result of the oral opportunistic infection candidiasis or oral hairy leukoplakia and also by concurrent HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed2000

Periodontal status by CPITN, and associated variables in an Israeli permanent force military population.

AIMS: The objectives were to determine periodontal treatment needs using the CPITN index, of Israeli permanent force military personnel. METHODS: The study population consisted of 1300 military personnel aged 25-44 years (mean age 33.8 +/- 5.4), who attended obligatory routine medical and dental examinations. Clinical examinations were conducted by 3 calibrated examiners, employing flat dental mirrors, the specially designed WHO periodontal probes (FDI probes) and following CPITN criteria. The frequency distributions were studied with regard to age groups, gender and education, as well as differences in the severity of the disease. Also, the mean number of sextants affected per person by age was assessed. RESULTS: Only 1.19% of the subjects demonstrated healthy periodontal tissue. Shallow pockets were similarly found among all age groups, and the number of persons with deep pockets increased with age. Deep pockets were found almost 3 x more among males (18.66%) in comparison with females (6.19%). Persons with higher education (> 12 years), had less deep pockets and bleeding than individuals with less than 12 years of education (p<0.05). CONCLUSIONS: Compared with data from other countries reported by the WHO, this periodontal status indicates a relatively high level of treatment needs. This survey provides a substantial contribution to the national oral health data bank concerning the adult working population in Israel.

Adult↗
PubMed2000

Trends in caries and associated variables among young Israeli adults over 5 decades.

This study was conducted among a representative sample of 7,139 21-year-old Israeli adults, upon release from compulsory military service. Data were collected between 1994 and 1997. The average DMFT level found was 8.49+/-4.95. Untreated caries (according to the D component of DMFT) was 2.25+/-2.90 and significantly higher among males. Untreated caries was also significantly associated with geographic origin: higher among subjects of African or former USSR descent; and with family size: higher among subjects with four or more siblings; with education: caries was higher among subjects with less than 12 years of schooling; and with smoking: caries was more extensive among those who smoked (P<0.0001 for all the associations). Caries severity (DMFT) was found to be significantly associated with father's country of origin and number of siblings (highest among subjects of Asian and African descent and those who had four or more siblings). This is the largest and most representative Israeli survey of young adults to date. Data were compared with available data from studies conducted in 1956, 1966, 1973, and 1985. DMFT scores had previously increased from the 1950s until the 1980s. Treatment levels had increased since the 1980s. The present data, together with results of studies conducted among Israeli children, indicate a recent national decrease in caries experience. This study indicates a further increase in caries treatment level, but a persisting inequity according to social variables.

Adult↗
PubMed2000

Effects of methylphenidate (Ritalin) on auditory performance in children with attention and auditory processing disorders.

A double-blind, placebo-controlled study was used to investigate the effects of methylphenidate (Ritalin) on tests of auditory processing in children diagnosed with both Attention Deficit Hyperactivity Disorder (ADHD) and Central Auditory Processing Disorder (CAPD). Thirty-two subjects received three Central Auditory Processing (CAP) tests and the Auditory Continuous Performance Test (ACPT), a measure of attention/impulsivity, at two separate test sessions: once when medicated with Ritalin and once when nonmedicated (placebo). Sixteen subjects were assigned randomly to receive their medication first and 16 to receive the placebo first. A counterbalanced 2 x 2 mixed factorial analysis of variance was conducted for each of the four dependent variables: Staggered Spondaic Word (SSW), Phonemic Synthesis (PS), Speech-in-Noise (SN), and ACPT measures. Analyses revealed that Ritalin did not have a significant effect on any of the three CAP measures. However, ACPT performance was significantly better (p < .000) for the Ritalin versus placebo condition.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

Maternal low-dose vitamin A or beta-carotene supplementation has no effect on fetal loss and early infant mortality: a randomized cluster trial in Nepal.

BACKGROUND: The effect of vitamin A supplementation on the survival of infants aged <6 mo is unclear. Because most infant deaths occur in the first few month of life, maternal supplementation may improve infant survival. OBJECTIVES: The objective was to assess the effect of maternal vitamin A or beta-carotene supplementation on fetal loss and survival of infants <6 mo of age. DESIGN: Married women of reproductive age in 270 wards of Sarlahi district, Nepal, were eligible to participate. Wards were randomly assigned to have women receive weekly doses of 7000 microg retinol equivalents as retinyl palmitate (vitamin A), 42 mg all-trans-beta-carotene, or placebo. Pregnancies were followed until miscarriage, stillbirth, maternal death, or live birth of one or more infants, who were followed through 24 wk of age. RESULTS: A total of 43559 women were enrolled; 15832 contributed 17373 pregnancies and 15987 live born infants to the trial. The rate of fetal loss was 92.0/1000 pregnancies in the placebo group, comparable with rates in the vitamin A and beta-carotene groups, which had relative risks of 1.06 (95% CI: 0.91, 1.25) and 1.03 (95% CI: 0.87, 1.19), respectively. The 24-wk mortality rate was 70.8/1000 live births in the placebo group, comparable with rates in the vitamin A and beta-carotene groups, which had relative risks of 1.05 (95% CI: 0.87, 1.25) and 1.03 (95% CI: 0.86, 1.22), respectively. CONCLUSIONS: Small weekly doses of vitamin A or beta-carotene given to women before conception, during pregnancy, and through 24 wk postpartum did not improve fetal or early infant survival in Nepal.

Adult↗
PubMed2000

Hookworms, malaria and vitamin A deficiency contribute to anemia and iron deficiency among pregnant women in the plains of Nepal.

Anemia and iron deficiency during pregnancy are prevalent in developing countries, but their causes are not always known. We assessed the prevalence and severity of anemia and iron deficiency and their association with helminths, malaria and vitamin A deficiency in a community-based sample of 336 pregnant women in the plains of Nepal. Hemoglobin, erythrocyte protoporphyrin (EP) and serum ferritin were assessed in venous blood samples. Overall, 72.6% of women were anemic (hemoglobin < 110 g/L), 19.9% had moderate to severe anemia (hemoglobin < 90 g/L) and 80.6% had iron deficiency (EP > 70 micromol/mol heme or serum ferritin < 10 microg/L). Eighty-eight percent of cases of anemia were associated with iron deficiency. More than half of the women (54.2%) had a low serum retinol concentration (<1.05 micromol/L), 74.2% were infected with hookworms and 19.8% had Plasmodium vivax malaria parasitemia. Hemoglobin, EP and serum ferritin concentrations were significantly worse and the prevalence of anemia, elevated EP and low serum ferritin was increased with increasing intensity of hookworm infection. Hookworm infection intensity was the strongest predictor of iron status, especially of depleted iron stores. Low serum retinol was most strongly associated with mild anemia, whereas P. vivax malaria and hookworm infection intensity were stronger predictors of moderate to severe anemia. These findings reinforce the need for programs to consider reducing the prevalence of hookworm, malaria infection and vitamin A deficiency where indicated, in addition to providing iron supplements to effectively control anemia.

Adolescent↗
PubMed2000

Vitamin A or beta-carotene supplementation reduces symptoms of illness in pregnant and lactating Nepali women.

The contribution of nutritional interventions to the reduction in maternal morbidity rates in developing countries is not well known. We assessed the impact of weekly vitamin A and beta-carotene supplementation on the prevalence of pregnancy and postpartum illness symptoms among 15,832 Nepali women in a placebo-controlled, double-masked, cluster-randomized trial. There was no impact of either supplement on morbidity rates reported up to 28 wk of gestation, inclusive. However, in late pregnancy (>28 wk), symptoms of nausea, faintness and night blindness were reduced with vitamin A, but not beta-carotene, supplementation. Vitamin A supplementation shortened the length of labor by 1.5 h 50 min among nulliparous and multiparous women, respectively. Both interventions reduced the postpartum prevalence of at least four loose stools and night blindness. beta-Carotene supplementation also reduced symptoms of high fever postpartum. The mean number of days of any reported illness symptoms was 3-4 per wk throughout pregnancy. Among women receiving vitamin A, the total number of days of illness symptoms accrued over the last 12 wk of pregnancy was lower by 5 d compared with the placebo recipients. We found the burden of pregnancy-related illness symptoms to be high in this rural area of Nepal where antenatal care is poor and most deliveries occur at home. Maternal vitamin A or beta-carotene supplementation resulted in a reduction in the prevalence of selected illness symptoms during late pregnancy, at the time of birth and during 6 mo postpartum, suggesting that a diet adequate in vitamin A may be important for improving women's reproductive health.

Adult↗
PubMed2000

The onset time of rocuronium is slowed by esmolol and accelerated by ephedrine.

Administration of ephedrine prior to rocuronium decreases the onset time of neuromuscular blockade from rocuronium by 26%. This effect was attributed to a increased cardiac output. If so, beta adrenergic-blocking drugs, which decrease cardiac output, should prolong the onset time of rocuronium. In a double-blind study, 60 patients were randomly assigned to three groups (n = 20) to receive either 70 microg. kg(-1) of ephedrine, 0.5 mg. kg(-1) esmolol or placebo, 30 s before induction of anesthesia. Onset time of rocuronium was defined as the time from the end of its injection to disappearance of all four twitches of the train-of-four. The onset time of rocuronium was significantly shorter after ephedrine (22%) and longer after esmolol (26%), as compared to placebo. No differences were observed among the three groups with regard to heart rate, systolic, diastolic or mean blood pressure. We concluded that a dose of 0.5 mg. kg(-1) of esmolol significantly prolongs the onset time of rocuronium with minimal hemodynamic changes.

Adolescent↗
PubMed2000

Age is not an impediment to effective use of patient-controlled analgesia by surgical patients.

BACKGROUND: Obstacles to the use of patient-controlled analgesia (PCA) by elderly surgical patients have not been well-documented. Age differences in preoperative psychological factors, postoperative pain and analgesic consumption, treatment satisfaction, and concerns regarding PCA were measured to identify factors important to effective PCA use. METHODS: Preoperatively, young (mean age +/- SD, 39 +/- 9 yr; n = 45) and older (mean age +/- SD, 67 +/- 8 yr; n = 44) general surgery patients completed measures of attitudes toward and expectations of postoperative pain and PCA, psychological distress, health opinions, self-efficacy, and optimism. On the first 2 postoperative days, pain at rest and with movement and satisfaction with pain control were assessed using visual analog scales. Daily opioid intake was recorded. When PCA was discontinued, satisfaction and concerns about it were assessed. RESULTS: The older patients expected less intense pain (P </= 0.003) and preferred less information about (P </= 0.02) and involvement in (P </= 0.002) health care than young patients. There were no age differences with regard to pain at rest (P </= 0.22) or with movement (P </= 0.68). The older group self-administered less opioid than the young group (P </= 0.0001) and received PCA for more days than the young group (P </= 0.004). The groups did not differ in concerns about pain relief, adverse drug effects, including opioid addiction, and equipment use or malfunction. Satisfaction with PCA was high and did not differ between the groups. CONCLUSIONS: Patient-controlled analgesia use was not hindered by age differences in beliefs about postoperative pain and opioids. Younger and older patients attained comparable levels of analgesia and were equally satisfied with their pain control.

Adult↗
PubMed2000

Effects of presurgical local infiltration of bupivacaine in the surgical field on postsurgical wound pain in laparoscopic gynecologic examinations: a possible preemptive analgesic effect.

OBJECTIVE: A randomized, double-blind, controlled study was designed to evaluate the effect of presurgical local infiltration of bupivacaine in the surgical field on postsurgical wound pain relief and analgesic requirements in 28 healthy patients scheduled for laparoscopic gynecologic examinations. INTERVENTIONS: After induction of general anesthesia by routine methods, the patients were randomly divided into two groups. In the bupivacaine (B) group (n = 15), patients were injected with 5 ml of 0.25% bupivacaine at each incisional area (four sites, total of 20 ml) approximately 15 minutes before skin incision. In the control (C) group (n = 13), the surgical field was injected with an equal volume of physiologic saline solution (four sites, total of 20 ml). OUTCOME MEASURES: Postsurgical wound pain at rest was evaluated by a 10-cm visual analog pain scale at 1, 10, 24, and 72 hours and 1 month after surgery. The patients were interviewed via telephone 1 month after hospital discharge for re-evaluation of resting pain. RESULTS: The results indicated that the incidence of postsurgical wound pain for up to 10 hours after surgery in group B was significantly lower (p < 0.05) than in group C. Pain intensity ranged from mild to moderate (2-5 cm). In addition, the mean visual analog pain scale pain intensity was significantly less for group B (0.31 +/- 0.85 cm) than for group C (2.62 +/- 2.06 cm) for up to 10 hours after surgery (p < 0.05). The number of patients who requested analgesics and complained of sleep disturbances was significantly higher in group C (p < 0.05). The mean cumulative dose of diclofenac sodium at 24 hours was significantly (p < 0.05) lower in group B (6.67 +/- 17.6 mg) than in group C (30.8 +/- 25.3 mg). Prolonged postsurgical wound pain persisting 1 month after surgery was observed in one patient in group C. CONCLUSIONS: It is concluded that presurgical infiltration of 0.25% bupivacaine in the surgical field is a useful method for decreasing postsurgical wound pain for up to 10 hours and analgesic consumption for up to 24 hours after laparoscopic gynecologic examination.

Adult↗