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Biomedical subjects

P Rosenfeld

Publications and source records attributed to P Rosenfeld.

At least 19 recordsLinked to original sources
PubMed2006

[Early effects of systemic and intravitreal bevacizumab (avastin) therapy for neovascular age-related macular degeneration].

PURPOSE: The purpose of this study was to evaluate the early treatment response following systemic and intravitreal bevacizumab therapy in patients with neovascular age-related macular degeneration (AMD). PATIENTS AND METHODS: In a prospective cohort study 12 eyes with neovascular AMD were treated with 5 mg/kg systemic bevacizumab, and 13 eyes with 1 mg intravitreal bevacizumab. Systemic therapy was given three times at 2-week intervals, intravitreal therapy up to three times at 4-week intervals. Patients were evaluated according to best corrected visual acuity (VA) and optical coherence tomography (OCT) at baseline as well as at week 1, week 4 and week 12 after therapy. Fluorescein angiography (FA) was performed at baseline and week 12. RESULTS: Systemic and intravitreal bevacizumab therapy showed a treatment response within one week. Visual acuity improved at week 1 by 4.9 letters from baseline in the systemic and by 6.9 letters in the intravitreal treatment group. Central retinal thickness (CRT), as measured by OCT decreased by 51.9 microm and 176.4 microm, respectively. At month 3 a persistent treatment effect was detectable. Mean gain in visual acuity was 11 letters in the systemic and 8.3 letters in the intravitreal group, CRT had decreased by 100 microm and 153.8 microm, respectively. Leakage as evaluated by FA was significantly reduced or absent in all patients. CONCLUSION: The early treatment responses following systemic and intravitreal bevacizumab appear to be similar. Both groups show improvement in VA and decrease in CRT within 1 week and up to 3 months. Long-term follow-up is required to evaluate the safety and treatment durability of both treatment modalities using bevacizumab.

Aged↗
PubMed2005

The use of tranexamic acid to reduce blood loss during total hip arthroplasty: an observational study.

INTRODUCTION: To test the hypothesis that the fall in haemoglobin following total hip arthroplasty is reduced by tranexamic acid administration. PATIENTS AND METHODS: A cohort of 64 patients were studied, 32 received tranexamic acid 20 mg/kg on induction. Surgery was performed by the senior author in a standardised fashion. Haemoglobin levels were measured 2 weeks pre- and 3 days postoperatively. Any complications were noted. The study group was matched using the bone and joint research database for age, sex, procedure, disease and pre-operative haemoglobin level. RESULTS: In the group receiving no tranexamic acid, the mean fall in haemoglobin was 3.8 g/dl (CI of mean 3.4-4.3) and in the group treated with tranexamic acid 2.8 g/dl (CI of mean 2.5-3.2) P < 0.05. Complications included one non-fatal pulmonary embolus in the tranexamic acid group. CONCLUSIONS: The administration of 20 mg/kg of tranexamic acid on induction of surgery is an effective method of reducing the haemoglobin fall following hip arthroplasty.

Antifibrinolytic Agents↗
PubMed2003

[Dental implants following trauma in young adults].

Various statistics have shown that avulsion (total displacement of tooth out of its socket) following traumatic injuries is relatively infrequent, ranging from 0.5 to 16% of traumatic injuries in the permanent dentition. The maxillary central incisors are the most frequently avulsed teeth. Avulsion of teeth occurs most often in children from 7 to 9 years of age, when the permanent incisors are erupting. Most frequently, avulsion involves a single tooth; but multiple avulsion are occasionally encountered. Fractures of the alveolar socket wall are often associate with avulsion. After the tooth is lost, an almost certain sequelae is the rapid resorption of alveolar bone. In many cases, only a very thin crestal bony lamella remains after healing of the alveolus, with clinically obvious horizontal and vertical depressions. In a young patient missing an anterior tooth, the operator may find implant insertion, in the proper anatomical position, difficult or impossible, because of inadequate bone volume. This situation aggravates with time because of continuous resorption and relative growth of the adjacent alveolar bone around the teeth. New and predictable bone augmentation techniques allow compensation for bone reduction while waiting for completion of growth. In cases of localized ridge augmentation, the amount of initial bone volume and its shape dictate whether implant insertion and bone augmentation will be performed simultaneously. The indications for this approach are: sufficient bone volume to achieve initial implant stability and a predictably high success rate for the augmentation. When bone volume and shape do not allow for initial stability, there is indication for a staged approach, in which the bone is initially augmented, the results are evaluated and the implant is then inserted. The first stage, the bone regeneration phase, may last between 8-10 months. The second, the implant integration period, may take an additional 6-8 months. The effect of growth on the augmented bone is not quite clear and there is only a paucity of information concerning the use of bone regeneration procedures in growing patients. Clinical decision when to start implant treatment after avulsion is dependent not only on the timing of implant insertion, but also on bone regeneration procedures. When most of horizontal and vertical bony walls of the extraction site is lost, augmentation procedure as a measure to reduce the deficiency, may be considered even in preadolescents. Three cases describing different clinical situations following avulsion, tooth replacement, resorption, regeneration treatment and implant insertion are discussed.

Adolescent↗
PubMed2000

Engaging staff nurses in evidence-based research to identify nursing practice problems and solutions.

This article illustrates how one academic health science center in a large metropolitan area sought to improve the quality of patient care by soliciting the input of their nursing staff in devising an action plan for change. The research model incorporated both survey and focus group methods used by nursing leaders in administration and practice to identify and prioritize nursing research and clinical needs in their organization. The goal was to establish consensus among clinicians and researchers about significant issues in the institution requiring in-depth attention. A second objective was to design a survey instrument that is easy to complete and could be distributed, collected, and analyzed easily, thereby providing empirical data to the clinicians in a timely manner and in a simple format. This expedited process enabled specific action plans to be developed around the identified problems. Moreover, the process promoted interest in advancing nursing research and evidence-based practice among the clinicians and administrators.

Adult↗
PubMed1997

The information age: the status of technology in nursing education programs in the United States.

The purpose of this research was to determine the status of technology in nursing education in the United States. The research design was a comparative descriptive survey of a stratified random sample of National League for Nursing accredited diploma, associate, baccalaureate and master programs. The instrument for data collection was developed by a panel of six experts in the area of educational technology. The survey, mailed to 347 randomly selected schools, identified four primary areas of investigation: 1) technology inventory, 2) technology applications and content, including education and clinical areas, 3) implementation plan, and 4) decision making including funding and staffing resources. Findings indicated there was a significant difference in available electronic resources among baccalaureate, associate and diploma programs. A majority of schools utilize computer applications to enhance teaching, but a very small percentage of schools addressed informatics in the curriculum. The project was funded by a grant from the Helene Fuld Health Trust Fund.

Attitude to Computers↗
PubMed1997

Practice and employment trends among nurse practitioners in New York State.

This study describes nurse practitioners' (NPs) practice and employment trends, primary care/direct patient care involvement, scope of practice issues, productivity, and demographic characteristics. Data were collected by mailed survey from 2,499 NPs in New York State. NPs were predominantly certified as Adult, Pediatric or Family NPs. The vast majority of NPs were working (64.1% full-time; 22.7% part-time). Fifty percent said they spend over 80% of their time providing primary care. Over 50% of the NPs employed in non-hospital settings said that their organizations had contracts with four or more managed care organizations.

Adult↗
PubMed1996

Long-term effects of neonatal maternal deprivation and ACTH on hippocampal mineralocorticoid and glucocorticoid receptors.

In the brain, corticosteroids bind to two types of receptors, the classical glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). The effects of different manipulations taking place during early ontogeny on GR and MR binding properties were examined in the adult hippocampus. Infant rats at postnatal day (pnd) 3 were deprived of maternal contact for 24 h and injected with saline or ACTH1-24 at the end of the deprivation period. They were then returned to their dams and weaned on pnd 21. At pnd 48, they were sacrificed (24 h post adrenalectomy) and the hippocampal MR and GR measured using an in vitro cytosol binding assay. In the male rats, deprivation and deprivation + ACTH resulted in a reduction of GRs. MRs were also significantly down regulated in the deprived males. In the female rats, saline injections in deprived female rats resulted in increased GR capacity and ACTH injections led to a further up-regulation of the GRs. None of the early manipulations influenced the regulation of the MRs in females. The binding affinity for corticosteroid receptors was also altered by some of the early manipulations. These results in adult (7-week-old) rats indicate that the receptor systems for corticosteroids in the brain are sensitive to brief manipulations occurring early in development. These changes in receptor capacity and/or affinity may affect corticosteroid-mediated processes in the adult rat.

Adrenalectomy↗
PubMed1994

Effects of gender and ethnicity on Hispanic women in the U.S. Navy.

Hispanic women in the U.S. Navy were surveyed to obtain data on demographics and attitudes. The results of the survey indicated that Hispanic women in the navy did not perceive themselves as "doubly disadvantaged," as they have been portrayed in the civilian literature. There were few significant differences between Hispanics' and Whites' perceptions on equal opportunity and sexual harassment.

Attitude↗
PubMed1993

Maternal regulation of the hypothalamic-pituitary-adrenal axis in the infant rat: the roles of feeding and stroking.

Twenty-four hours of maternal separation results in increased secretion of ACTH and corticosterone (CORT), suggesting the hypothalamic-pituitary-adrenal (HPA) axis is regulated by some aspect of maternal behavior. Previous results indicate that feeding plays a role in maintaining low levels of CORT in 12-day-old pups. In Experiment 1 basal and stress levels of CORT and ACTH were measured in maternally-deprived pups either provided or not with milk to determine whether: (1) feeding maintains ACTH secretion at low levels, and/or (2) feeding maintains the adrenal insensitive to ACTH. The results showed that, although ACTH levels were markedly low (compared to previous values reported by this laboratory) for both groups, only non-fed pups showed a robust increase in basal and stress CORT levels. During the deprivation period in Experiment 1, all pups were manually stroked to induce urination and defecation, suggesting an effect of stroking on ACTH secretion. Experiment 2 examined this hypothesis. Stroking suppressed stress-induced elevations of ACTH secretion due to maternal deprivation. CORT levels, however, were elevated in all deprived pups. The results indicate that maternal regulation of the infant's HPA axis occurs at multiple levels. Feeding appears to regulate adrenal sensitivity, whereas anogenital stroking inhibits the activation of centrally-controlled components of the axis.

Adrenocorticotropic Hormone↗
PubMed1993

Maternal regulation of adrenocortical activity in the infant rat: effects of feeding.

Basal and stress-induced corticosterone release in the infant rat has been shown to be inhibited by some aspect of maternal care. The following studies examined specific maternal cues that might be responsible for this regulation. In Experiments 1 and 2, 12-day-old pups remained with their dam but were either prevented or not from feeding; at the end of 24 hr, basal and stress-induced corticosterone levels were measured. Only those animals that were able to feed showed the hyporesponsiveness characteristic of nondeprived animals, suggesting that feeding rather than some other aspect of maternal care was the critical variable. In Experiment 3, all animals were maternally deprived, and some of them were fed via an intracheek cannula. Once again, feeding led to a pronounced diminution in both basal and stress-induced levels of corticosterone. Our results point to feeding as one of the critical features responsible for the inhibitory effect of the dam on the infant's adrenocortical activity.

Animals↗
PubMed1993

Ontogeny of corticosteroid receptors in the brain.

1. In the brain, glucocorticoids bind to both the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). These receptors show clearly distinct developmental patterns in the infant rat. 2. Low levels of GRs are present around the time of birth throughout the brain. Concentrations rise slowly, and do not achieve adult levels until the third week of life, approximately. GR affinity for corticosterone is higher perinatally than at later ages. Receptor microdistribution changes dramatically during ontogeny. In particular, certain regions, such as the suprachiasmatic nucleus of the hypothalamus, express high levels of receptor only during the first week of life. GRs may show impaired capacity to undergo transformation and/or nuclear translocation during the second postnatal week. Environmental manipulations during early ontogeny (e.g., early handling) may have permanent effects on GR capacity. 3. MRs are present at very low concentrations in the first days of life. Binding capacity rises rapidly thereafter and resembles that found in the adult by the end of 1 week. Neither binding affinity in vitro nor overall distribution changes with age. As in the adult, low doses of corticosterone, in vivo, bind mainly to the MRs. Levels of corticosterone are low and relatively unperturbable in the intact infant rat. It is likely, therefore, that most of the physiological actions of this hormone during this period are mediated by the MR.

Aging↗
PubMed1993

Effects of maternal deprivation on the ACTH stress response in the infant rat.

Prolonged maternal deprivation during early ontogeny results in increased basal and stress-induced corticosterone levels. In the following experiments we examined whether these increases were due, at least in part, to augmented ACTH secretion. Thus, ACTH levels were measured in 24-hour maternally deprived and nondeprived 6-, 9-, and 12-day-old pups exposed to a mild stressor (i.e. saline injection followed by placement in a novel environment at room temperature). The results showed: (1) nondeprived pups showed a small response to saline--the response of deprived pups, however, was greater than that of nondeprived pups; (2) the magnitude of the response increased with age; (3) ACTH levels remained elevated for at least 30 min. Subsequent experiments examined whether the continuous exposure to novelty and/or loss of body heat could explain the persistence of this response. Neither variable affected the ACTH response to saline. Our results indicate that factors of maternal origin are partly responsible for the regulation of the ACTH response to stress. Furthermore, the persistence of the response suggests that the negative feedback system in the infant is immature.

Adrenocorticotropic Hormone↗
PubMed1992

Effects of repeated maternal separations on the adrenocortical response to stress of preweanling rats.

Previous data indicate that the infant rat shows a marked increase in adrenocortical responsiveness to stress immediately following prolonged maternal separation. In Experiment 1 we studied the immediate effects of repeated maternal deprivation. Our results indicate that the increase in basal as well as stress-induced corticosterone levels is a direct function of the length of the deprivation period immediately preceding testing, and is not cumulative. In Experiment 2 we examined the long-term consequences of maternal deprivation on adrenal responsivity. Four days following a single 24-h period of maternal deprivation, pups remained hyperresponsive to stress, although their basal levels of corticosterone had returned to control values. Shorter periods of deprivation (which did result in increased responsivity immediately following deprivation) did not have persistent effects. Our data suggest: 1) short periods of deprivation do not have a cumulative effect, and 2) there is a critical length of deprivation beyond which persistent changes in adrenocortical responsivity ensue.

Animals↗
PubMed1992

Multifactorial regulation of the hypothalamic-pituitary-adrenal axis during development.

The hypothalamic-pituitary-adrenal system shows an overall diminished responsiveness throughout ontogeny. Thus, during this period, the sensitivity of the adrenal gland to ACTH is markedly reduced. Furthermore, basal and stress-induced concentrations of corticosterone (CORT), ACTH and hypothalamic secretagogues remain at very low levels. Both structural immaturity and active inhibitory processes appear to underlie this overall hyporesponsiveness. The available data indicate that the characteristic developmental pattern of the HPA system results from multiple regulatory factors acting in conjunction at various levels of the axis. The primary rate-limiting steps, however, are probably at the brain and adrenal levels. The ultimate "goal" appears to be to keep CORT levels within the narrow range of concentrations required for normal development.

Animals↗