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Biomedical subjects

R Epstein

Publications and source records attributed to R Epstein.

At least 37 records · Page 2Linked to original sources
PubMed1997

Popularity of less frequent follow up for breast cancer in randomised study: initial findings from the hotline study.

OBJECTIVE: To compare the experiences of patients with breast cancer who were conventionally monitored with those in whom routine follow up was restricted to the time of mammography. DESIGN: Randomisation to conventional schedule of clinic visits or to visits only after mammography. Both cohorts received identical mammography and were invited to telephone for immediate appointments if they detected symptoms. SETTING: Combined breast clinic, Chelsea and Westminster Hospital. SUBJECTS: 211 eligible outpatients with a history of breast cancer. MAIN OUTCOME MEASURES: Acceptability of randomisation, interim use of telephone and general practitioner, satisfaction with allocation to follow up. RESULTS: Of 211 eligible patients, 196 (93%) opted for randomisation in the study. Of these, 55 were under 50 years, 78 were diagnosed fewer than five years before, 90 had stage T2-4 tumours, and 71 had involved axillary nodes. Patients who did not participate were more likely to be under 50 years, to be two to five years after diagnosis, and to have had aggressive primary disease. Twice as many patients in both groups expressed a preference for reducing rather than increasing follow up. No increased use of local practitioner services or telephone triage was apparent in the cohort randomised to less frequent follow up by specialists. CONCLUSIONS: Reducing the frequency of routine follow up has so far proved popular among patients with breast cancer at standard risk in this cohort. A multicentre study is needed to determine the effectiveness and cost-effectiveness of routine follow up with respect to disease outcomes.

Adult↗
PubMed1997

Dichotic listening in children: the reflection of verbal and attentional changes with age.

A sample of 290 kindergarten children (147 girls), all native Hebrew speakers, were tested by two dichotic listening tests: (a) a digits test (low verbal workload) and (b) a words test (high verbal workload). The same subjects were tested one year later (at the end of their first year at school) by the same tests. In both tests and both testing sessions the free recall procedure was used. It was found that the performance difference between ears significantly decreased and overall performance significantly increased in the digits test in the second testing session. Differences between sessions in ear difference in the words test were not significant, although overall performance in the second session increased. These data lend support to the hypothesis that the change with age in the between-ears difference is mainly related to an improvement in verbal processing efficiency, which in turn allows the allocation of more verbal resources to the inferior input channel, without a decrease in resources allocated to the preferred one. As expected, increase in available verbal resources was clearly manifested under low verbal workload conditions but not under high workload conditions, where task demands did not allow significant increase in verbal resources to be allocated to the inferior channel. This hypothesis also predicted highly consistent ear preference owing to its being solely determined by the verbal processors of the dominant-to-speech hemisphere. The inconsistent ear preference between tests found in more than a third of the subjects of this sample could not therefore be accounted for by the stated hypothesis. The analysis of performance in subjects who showed left-ear preference in only one test and right-ear advantage on the other occasions indicated that whenever the left ear was preferred it was accompanied by significantly smaller ear difference and lower overall performance compared with those manifested by the same subjects in the same test in the other testing session. These data are better accounted for by the hypothesis that two different pools of resources are involved in splitting attention between ears in the free recall of dichotically presented verbal stimuli: one which is controlled by verbal processors of the dominant-to-speech hemisphere and the other by a spatial attentional mechanism. However, it seems that changes in dichotic test performance within the first year at school can mainly be attributed to increase in verbal resources rather than to improvement in allocation of spatially controlled resources.

Age Factors↗
PubMed1997

The economic cost of hip fractures in community-dwelling older adults: a prospective study.

OBJECTIVES: To evaluate the incremental cost in the year after hip fracture. DESIGN: Prospective cohort study. SETTING: Baltimore, Maryland. PARTICIPANTS: 759 community dwelling older patients who sustained a hip fracture and participated in the Baltimore Hip Fracture Study. MEASUREMENTS: Resource use for direct medical care, formal nonmedical care, and informal care in the 6 months before and the year after fracture was estimated from interviews with patients or proxy respondents. Costs in 1993 dollars were estimated by multiplying resources times national unit cost estimates. RESULTS: The annualized costs in the year before the fracture ranged between $18,523 and $20,928. The costs in the year after the fracture equaled $37,250. The incremental costs in the year after the fracture, compared with the costs in the year before the fracture, ranged between $16,322 and $18,727. The largest cost differences were attributable to hospitalizations, nursing home stays, and rehabilitation services. CONCLUSIONS: Because we compared the costs after a fracture with costs before, our estimates of the incremental cost of a hip fracture are lower than others in the literature. These results, obtained from interviews with patients enrolled in a cohort study, or their proxies, provide the best data available to date on the economic cost of hip fractures among community-dwelling older persons.

Aged↗
PubMed1997

The short-term impact of Botox injections on speech disability in adductor spasmodic dysphonia.

This study investigates the impact of Botox injections on speech disability in a group of patients with adductor spasmodic dysphonia. Patient-perceived disability was assessed on the Speech Disability Questionnaire. A factor analysis on speech disability yielded five factors. Four of these, social isolation (p < 0.001), negative communication (p < 0.005), public avoidance (p < 0.05) and limited understanding (p < 0.01), showed significant change from prior to and one week post injection. Speech and language therapists' assessment also showed changes in voice quality over the same period. These findings are discussed in terms of the relationship between voice quality, disability and handicap, in adductor spasmodic dysphonia.

Adult↗
PubMed1997

Changing from communal to familial sleep arrangement in the Kibbutz: effects on sleep quality.

Sleep was actigraphically investigated in 27 Kibbutz children while sleeping in communal sleeping houses, and 1 year after changing to familial sleeping arrangements. Three independent control groups of city-living children were also recorded. Two of them were age-comparable, and the third control group was included in order to examine possible effects of the Gulf War on the communal sleep group. The results showed that the sleep quality of Kibbutz children improved significantly after moving to familial sleep. Comparison with the data from the two control groups revealed a greater resemblance between sleep of the Kibbutz children after moving to live with their families and that of the city-living children. Comparing the sleep of the children in communal sleep to that of the additional group of children examined during the Gulf War strengthened the above results, i.e. the communal sleep group that was investigated before the war slept worse than the control children that were investigated during the war. After discarding developmental and physical condition-related changes, it was concluded that the improvement in sleep quality was due to the children's increased sense of security when sleeping with their families.

Child, Preschool↗
PubMed1996

Human cancer cells exhibit protein kinase C-dependent c-erbB-2 transmodulation that correlates with phosphatase sensitivity and kinase activity.

The c-erbB-2 receptor tyrosine kinase is often overexpressed in human tumors, but the functional implications of this phenotype remain unclear. We previously used phosphorylation-specific antibodies to define major differences in c-erbB-2 tyrosine kinase activity between overexpressing human tumor cell lines (Epstein, R. J., Druker, B. J., Roberts, T. M., and Stiles, C. D. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 10435-10439). Here we extend this approach to define the relationship between c-erbB-2 tyrosine phosphorylation and protein kinase C (PKC)-dependent transmodulation. Phosphorylation-specific antibodies to the juxtamembrane PKC site Thr686 recognize tyrosine-dephosphorylated wild-type c-erbB-2 following G8/DHFR 3T3 cell treatment with PKC agonists. B104-1-1 cells transformed by activated c-erbB-2 express a subset of tyrosine-phosphorylated receptors that are homologously phosphorylated on Thr686, indicating that Thr686 phosphorylation alone is insufficient to abrogate receptor tyrosine phosphorylation. Similarly, the c-erbB-2-overexpressing human cancer cell lines SK-Ov-3 and BT-474 express constitutively Thr686-phosphorylated receptors. SK-Ov-3 cells express predominantly kinase-inactive c-erbB-2 that is heavily Thr686-phosphorylated, indicating that Thr686 phosphorylation in this line is heterologous in origin. In contrast, BT-474 cells express constitutively autophosphorylated c-erbB-2 despite Thr686 phosphorylation. These results indicate that Thr686 phosphorylation does not directly abolish c-erbB-2 activity and suggest that such phosphorylation reflects constitutive PKC activity induced by either receptor-activating mutations or heterologous growth factors. The latter possibility suggests in turn that c-erbB-2 interacts in an as yet undefined way with heterologous growth factor receptors in human tumor cells.

Animals↗
PubMed1996

A comparison of sevoflurance to halothane in paediatric surgical patients: results of a multicentre international study.

Induction, emergence and recovery characteristics were compared during sevoflurane or halothane anaesthetic in a large (428) multicentre, international study of children undergoing elective inpatient surgical procedures. Two hundred and fourteen children in each group underwent inhalation induction with nitrous oxide/oxygen and sevoflurane or halothane. Incremental doses of either study drug were added until loss of eyelash reflex was achieved. Steady state concentrations of anaesthesia were maintained until the end of surgery when anaesthetic agents were terminated simultaneously. Time variables were recorded for induction, emergence and the first need for analgesia in the recovery room. In addition, in 86 of the children in both groups, venous blood samples were drawn for plasma fluoride levels during and after surgery. There was a trend toward smoother induction (induction of anaesthesia without coughing, breath holding, excitement laryngospasm, bronchospasm, increased secretion, and vomiting) in the sevoflurane group with faster induction (2.1 min vs 2.9 min, P = 0.037) and rapid emergence times (10.3 min vs 13.9 min, P = 0.003). Among the children given sevoflurane, 2% developed bradycardia compared with 11% in the halothane group. Postoperatively, 46% of the children in the halothane group developed nausea and or vomiting versus 31% in the sevoflurane group (P = 0.002). Two children in the halothane group developed cardiac dysrhythmia and were dropped from the study. In addition, a child in the halothane group developed malignant hyperthermia, received dantrolene, and had an uneventful recovery. Mean maximum inorganic fluoride concentration was 18.3 microM.l-1. The fluoride concentrations peaked within one h of termination of sevoflurane anaesthetic and returned rapidly to baseline within 48 h. This study suggests that sevoflurane may be the drug of choice for the anaesthetic management of children.

Adolescent↗
PubMed1996

Is school vision screening effective?

A population-based cohort of all children entering kindergarten in a three-year period (N = 2,938) was followed retrospectively from kindergarten through 12th grade to estimate incidence of abnormal school vision screening tests and rates of follow-up by community ophthalmologists or optometrists. Overall 28% of children had at least one abnormal school vision screening test. Abnormal screening with referral increased from 1.2% of five-year-olds to 9.1% of 13-year-olds. Overall, 91% of children referred had further evaluation by eye care professionals. However, visits to an eye care professional often were delayed; median time was 0.8 years for children seeing an ophthalmologist and 1.8 years for children seeing an optometrist. Results support the continued use of simple visual acuity screening in schools. Consideration should be given to screening children beyond age 12 and developing methods to increase the rapidity of parental response to referral recommendations.

Adolescent↗
PubMed1995

Comparison of methods for defining prevalent vertebral deformities: the Study of Osteoporotic Fractures.

Women with vertebral deformities caused by osteoporosis have more back pain and disability and are at higher risk for subsequent vertebral deformities than women without deformities. Despite the importance of vertebral deformities, there has been a great deal of controversy about how to identify or define them. In order to compare methods for defining vertebral deformities, we studied spinal radiographs from women in the Study of Osteoporotic Fractures (SOF), a cohort study of 9704 non-black women over age 65 recruited from population-based listings in four clinical centers. Using radiographs obtained at the baseline exam, we compared five methods for defining vertebral deformities: one based on a semiquantitative reading by a radiologist and four using vertebral morphometry. The semiquantitative method was compared with the other methods in a random sample of 503 films, while the morphometric methods were compared with each other in a larger sample of 9575 films. We tested a system of "triage" in which only those films with evidence of deformity were assessed by morphometry. We compared the relationship between deformity, defined by each method, and a variety of clinical criteria including bone mineral density at the lumbar spine, height loss since age 25, back pain, and incidence of subsequent deformity. Semiquantitative reading and three of the four morphometry-based methods provided similar relationships to clinical criteria. The fourth morphometry method (based on ratios of each vertebral height to the corresponding height at T4) produced significantly weaker relationships for several of the clinical validation criteria. Triage of radiographs rarely resulted in missed deformities and did not reduce the performance of any of the methods. We conclude that use of any of the similar methods, with or without triage, provides a valid approach to defining vertebral deformities.

Aged↗
PubMed1995

Calcium-inducible transmodulation of receptor tyrosine kinase activity.

Calcium is a potent mitogen and transmodulator of growth factor receptor activity, but does not activate tyrosine kinases in ligand-deprived cells (Epstein et al. 1992) Cell Growth Different. 3, 157-164). In this study the mitogenic and transcriptional effects of increased extracellular calcium and ionophore are shown to be identical in 3T3 cells, consistent with mediation of these effects via increased intracellular calcium availability. Near-maximal mitogenic and transcriptional effects are seen after brief exposure to increased extracellular calcium or ionophore, while additive effects occur with co-administration of calcium and platelet-derived growth factor (PDGF). Exposure of PDGF-primed cells to calcium or ionophore is associated with a substantial enhancement of receptor tyrosine autophosphorylation which is abrogated by calcium channel blockade or intracellular calcium chelation. In contrast, pretreatment of quiescent cells with calcium or ionophore significantly diminishes subsequent PDGF-inducible receptor autophosphorylation. Intracellular calcium thus appears to potentiate the kinase activity of ligand-stimulated PDGF receptors while inhibiting ligand-inducible activation of unstimulated receptors. These findings suggest a model of receptor tyrosine kinase regulation involving calcium-dependent positive and negative feedback loops which vary with the activation state of the receptor.

3T3 Cells↗