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Biomedical subjects

D Finkelstein

Publications and source records attributed to D Finkelstein.

At least 55 records · Page 3Linked to original sources
PubMed1995

Role of leukaemia inhibitory factor (LIF) in rat peripheral nerve regeneration.

The cytokine leukaemia inhibitory factor (LIF) favours the survival and growth of axons in vitro. The efficacy of this factor in the in vivo model has been the aim of this study. Following nerve transection and immediate entubulation repair in the rat sciatic nerve, this study demonstrated that (1) LIF promotes the growth of a population of axons of greater cross-sectional area after 6 and 12 weeks in comparison to either saline (negative control) or basic fibroblast growth factor (bFGF) (positive control), (2) LIF improves the nerve conduction velocity of regenerating axons, (3) LIF has a positive effect on skeletal muscle mass following nerve repair, (4) the benefits of LIF on skeletal muscle appear to be somewhat independent of reinnervation as similar observations are made where there is no growth of a tissue bridge within the tube, and (5) the effects of LIF seem to be potentiated by the addition of fibronectin.

Animals↗
PubMed1994

Clindamycin and primaquine therapy for mild-to-moderate episodes of Pneumocystis carinii pneumonia in patients with AIDS: AIDS Clinical Trials Group 044.

The objective of this prospective, noncomparative study was to assess the safety and efficacy of clindamycin and primaquine therapy for mild-to-moderate pneumocystis pneumonia (defined as a difference of < 40 mm Hg between the alveolar and the arterial oxygen determinations) in patients with AIDS. In the first part of the study, 22 patients were treated with iv clindamycin (900 mg every 8 hours) for the first 10 days, and then their therapy was switched to oral clindamycin (450 mg every 6 hours) for an additional 11 days. In the second part of the study, 38 patients were treated entirely with oral clindamycin (600 mg every 8 hours). All patients were treated with oral primaquine base (30 mg once daily). Fifty-five (92%) of 60 patients responded to the study treatment. Forty-six (77%) of 60 patients completed a full course of therapy. Of the nine patients with treatment-limiting toxic effects, four had only a mild rash. This study indicates that the combination of clindamycin and primaquine is an effective and well-tolerated therapy for mild-to-moderate pneumocystis pneumonia in patients with AIDS. Entirely oral therapy appears to be as effective as initial therapy with iv clindamycin.

AIDS-Related Opportunistic Infections↗
PubMed1994

Phase II trial of acivicin versus etoposide-cisplatin in non-small cell lung cancer. An Eastern Cooperative Oncology Group study.

Identification of effective new chemotherapeutic agents is a major objective of clinical research efforts in patients who have metastatic non-small cell lung cancer (NSCLC). Canadian investigators observed responses in NSCLC when acivicin was given as a daily IV bolus for 5 consecutive days. Based on these results the Eastern Cooperative Oncology Group tested acivicin as a continuous infusion in patients with advanced NSCLC. A total of 82 patients were entered on a Phase II trial in which patients have randomized either to acivicin 60 mg/m2 given as a continuous intravenous infusion over 72 hours repeated every 28 days or to the reference regimen which consisted of cisplatin 60 mg/m2 intravenously on day 1 and etoposide 120 mg/m2 daily on days 1, 2, and 3 repeated every 28 days. Five partial remissions (11%) were observed in 42 patients treated with etoposide-cisplatin, and no responses were observed in 40 patients treated with acivicin. Median survival durations for etoposide cisplatin and for acivicin were 29.7 and 21.1 weeks, respectively. Based on these results, acivicin appears to be inactive in NSCLC.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Visual hallucinations in patients from an ophthalmology clinic and medical clinic population.

Although visual hallucinations have been associated with patients with visual disorders, no study has specifically examined whether visual hallucinations are indeed more prevalent than in a general medical population. In this study, 127 consecutive visual disorder patients and 100 consecutive general medical patients were screened for complex visual hallucinations. A total of 6.3% of visual disorder patients and 2% of general medical patients had visual hallucinations. Interestingly, the two medical patients with visual hallucinations also had visual disorders. Factors significantly associated with visual hallucinations were female sex (p = .029) and lower cognitive score (p = .001). Data from a previous study of patients with the visual disorder age-related macular degeneration were combined with this study to increase the sample size of visual hallucinators. Factors significantly associated with visual hallucinations in the combined sample were female sex (p = .015), living alone (p = .019), having hearing problems (p = .047), older age (p = .013), and lower cognitive score (p < .001). Implications and future research are discussed.

Adolescent↗
PubMed1993

Informed consent and medical ethics.

Informed consent is based on a shared decision between physician and patient, with the physician understanding the relevant values of the patient and the patient understanding the nature of the disease and intervention, including risks and benefits. Informed consent has developed rapidly since it was introduced in the 1950s, reflecting recent changes in the practice of medicine that respect the increase of patient autonomy. The purpose of the written consent form is to document that a process of informed consent has taken place. It is generally agreed that all surgical as well as research procedures require written consent. For certain nonsurgical procedures, the decision regarding obtaining written consent will consider both the risk involved for the patient and the general community standard. Informed consent serves as an important symbol of a physician-patient relationship that adheres to the valued principles of medical ethics.

Consent Forms↗
PubMed1993

EST 2582 phase II trial of cisplatin in metastatic or recurrent thymoma.

In 1982 there were four reports of cisplatin-induced remissions of invasive thymoma. These observations led the Eastern Cooperative Oncology Group (ECOG) to conduct a Phase II trial of cisplatin (50 mg/m2 intravenously every 3 weeks). During a 4-year period 24 patients were entered on this trial; 3 were excluded because review of histologic material failed to confirm the presence of thymoma. The characteristics of the remaining 21 patients were as follows: median age, 51; males/females, 11/10; ECOG performance status, 0-1/2-3, 16/5; previous treatment with chemotherapy, 3; previous surgery, 20; previous radiation, 15; weight loss, < 5%/ > or = 5%: 17/4. One patient was eliminated from response analysis because of failure to return for follow-up tumor measurements. The following responses were observed in the remaining 20 patients. Partial remission, 2 (10%); stable disease, 8 (40%); and progression, 10 (50%). The median survival was 76 weeks, and the 2-year survival rate was 39%. Four patients experienced severe nausea and vomiting, but life-threatening and lethal toxicities were not observed. Cisplatin given at this dose was relatively ineffective in producing tumor regression in recurrent or metastatic thymoma.

Aged↗
PubMed1993

Neural activity in the monkey anterior ventrolateral thalamus during trained, ballistic movements.

1. To examine the role of the anterior ventrolateral thalamic nucleus (VLa) in motor control, extracellular single-cell recordings were made from the VLa nucleus in three conscious monkeys performing visually triggered, rapid movements requiring flexion and extension of the wrist joint. The movement paradigms consisted of three components: an initial hold period, a ballistic movement, and a final hold period. 2. Cerebellar nuclear stimulation was used to physiologically identify thalamic neurons receiving input from the cerebellum. Neurons subsequently confirmed histologically as lying within the VLa nucleus were located anterior to those "driven" by cerebellar stimulation. 3. The activities of 261 VLa neurons displaying movement-related behavior were examined. In the absence of movement, the activity of these neurons ranged from 5 to 80 spikes/s, the majority of cells (222/261; 85%) firing between 10 and 30 spikes/s. Neural activity was not influenced by afferent input from skin, joint, or muscle but altered markedly when the animal engaged in active movement. 4. The relationship between neural activity and movement at a specific joint was determined in 189 of the 261 neurons. The majority of these neurons (161/189; 85%) modulated their activity in response to movement confined to a single joint; the remaining neurons displayed multijoint motor responses, their activity being best related to a motor act, such as grasping, reaching, or feeding. There was no clear segregation in the representation of body parts in the VLa nucleus to suggest the presence of clearly defined somatotopy. 5. The activities of wrist-related neurons (45 of the 261) were examined to determine the motor characteristics of the VLa nucleus. Three distinctive activity patterns were exhibited by these neurons during the performance of the movement paradigms: 1) a phasic burst of < 300 ms in duration (34/45; 76%); 2) a sustained change in neural activity lasting > 300 ms (typically up to 1,000 ms; 4/45; 9%); and 3) both a phasic and a sustained response, the sustained response occurring either prior or subsequent to the phasic response (7/45; 15%). 6. The movement-related activity of the wrist-related neurons occurred late, 52% firing after the onset of the forearm electromyogram (EMG). In 47% of the neurons, discharge rate was related to movement direction and, in a smaller proportion (13%), joint position. No relationship was found between neural activity patterns and amplitude of movement or velocity of movement. (ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Ischemic macular edema. Recognition and favorable natural history in branch vein occlusion.

Eyes with macular edema caused by retinal branch vein occlusion underwent masked evaluation of fluorescein angiography to determine complete macular perfusion vs incomplete macular perfusion (capillary dropout, ischemia). Cases evaluated as incomplete macular perfusion showed a greater frequency of improvement (91%) in visual acuity than did perfused cases (29%) (P = .003) after a mean follow-up of 39 months. Ischemic edema is often transient, and is associated with a good outcome in visual acuity (median final visual acuity was 20/30). Perfused macular edema has a poorer prognosis for visual acuity (median final visual acuity was 20/80). Macular ischemia is usually associated with a broken foveal capillary ring. Previous animal research on ischemic brain edema has shown that following brain ischemia, an intracellular and an extracellular hypertonic environment lead to intracellular and extracellular edema (cytotoxic edema), which is often followed by vascular protein leakage (vasogenic edema). A similar occurrence in ischemic retina could explain the transient edema reported herein, with good outcome in visual acuity following the spontaneous resolution of edema.

Aged↗
PubMed1992

Visual hallucinations in patients with macular degeneration.

OBJECTIVE: This study was undertaken to determine the prevalence of visual hallucinations in patients with macular degeneration, describe such hallucinations phenomenologically, and possibly determine factors predisposing to their development. METHOD: Using a case-control design, the authors screened 100 consecutive patients with age-related macular degeneration for visual hallucinations. Each patient with visual hallucinations was matched to the next three patients without hallucinations. The patients and comparison subjects were compared in terms of scores on the Beck Depression Inventory, Eysenck Personality Questionnaire, Telephone Interview for Cognitive Status, and a structured questionnaire including demographic characteristics, family history, and medical and psychiatric history. Ophthalmologic data were obtained by chart review. RESULTS: Of the 100 patients, 13 experienced visual hallucinations. Four variables were significantly associated with having hallucinations: living alone, lower cognition score, history of stroke, and bilaterally worse visual acuity. Hallucinations were not associated with family or personal history of psychiatric disorder or with personality traits. In 11 (84.6%) of the 13 patients, the hallucinations had begun in association with an acute change in vision. CONCLUSION: These results indicate that visual hallucinations are prevalent among patients with macular degeneration. They appear unrelated to primary psychiatric disorder. The predisposing factors of bilaterally worse vision and living alone support an association with sensory deprivation, while history of stroke and worse cognition support a decreased cortical inhibition theory.

Aged↗
PubMed1991

Immediate reproducibility of electrically induced sustained monomorphic ventricular tachycardia before and during antiarrhythmic therapy.

The immediate reproducibility of sustained ventricular tachycardia induction was evaluated prospectively during 106 studies performed in 53 patients with clinical sustained monomorphic ventricular tachycardia. Programmed electrical stimulation was performed twice, using the same protocol during 53 drug-free studies and 53 subsequent studies on antiarrhythmic therapy. Sustained monomorphic ventricular tachycardia was reproduced in 104 (98%) of the 106 studies. There was no significant difference in the incidence of reproducible tachycardia in the drug-free state compared with that observed during treatment with different classes of antiarrhythmic drugs. An increase in the number of extrastimuli was required to reinitiate the tachycardia in 9 (11%) of 83 studies in which single or double extrastimuli were initially required to induce the tachycardia. In 39 (37%) of 104 studies with reproducible tachycardia induction, the two tachycardias significantly differed in electrocardiographic (ECG) configuration and cycle length. These observations suggest that the overall reproducibility of ventricular tachycardia induction is sufficiently high to provide a reliable marker for evaluating the efficacy of therapeutic interventions. However, specific tachycardia characteristics such as cycle length and ECG configuration are more variable even within the same study and may be less useful in assessing the effects of subsequent interventions.

Anti-Arrhythmia Agents↗
PubMed1991

Prevalence and prediction of hypoxemia in children with respiratory infections in the Peruvian Andes.

To determine the effect of respiratory infections on oxyhemoglobin saturation in a high-altitude population, we recorded clinical signs, oxyhemoglobin saturation determined by pulse oximetry, and findings on radiographs of the chest of 423 children with acute respiratory infections; the children were living at an altitude of 3750 m in the Peruvian Andes. We defined hypoxemia as an oxyhemoglobin saturation value greater than 2 SD below the mean value for 153 well children in this population. Eighty-three percent of children with clinical bronchopneumonia, but only 10% of children with upper respiratory tract infection, had hypoxemia (p less than 0.001). Compared with previous studies of children living at lower altitudes, the presence of tachypnea was relatively nonspecific as a predictor of radiographically determined pneumonia or of hypoxemia, especially in infants. A history of rapid breathing was 74% sensitive and 64% specific in the prediction of hypoxemia, and performed as well as a standard World Health Organization case management algorithm in the prediction of radiographic pneumonia or hypoxemia. Radiographic pneumonia was not a sensitive predictor of hypoxemia or clinically severe illness. In contrast, the presence of hypoxemia was a useful predictor of radiographic pneumonia, with both sensitivity and specificity of 75% in infants. We conclude that acute lower respiratory tract infection in children living at high altitude is frequently associated with hypoxemia, and that oxygen should be administered to children with a diagnosis of pneumonia in these regions. Case management algorithms developed in low-altitude regions may have to be modified for high-altitude settings. In this setting, pulse oximetry is a good predictor of pneumonia. Because pulse oximetry is more objective and cheaper than radiography, its role as a clinical and investigative tool merits further exploration.

Acute Disease↗
PubMed1991

Visual prostheses and visual rehabilitation in low vision research, assessment, and management.

This review is a highly selective and personal viewpoint regarding the past year's publications in low vision clinical practice and clinical research. This article reviews and provides references on selected aspects of low vision technology, reading, pediatric considerations, visual assessment for the multiply handicapped, and the psychosocial aspects of low vision and rehabilitation. We are impressed that the wealth of current publications underscores that this is an important, productive, and growing area of research and clinical activity.

Aged↗
PubMed1990

Visual acuity loss in retinitis pigmentosa. Relationship to visual field loss.

We compared visual acuity with visual field radius in 235 patients with typical retinitis pigmentosa and no evidence of other visual acuity-limiting problems (such as cataract or foveal cystoid edema). Results show a strong relationship between visual acuity loss and proximity to the fovea of the visual field border (shortest distance from the foveal center to the border of the V-4-e isopter) for these patients. Ninety-six percent of patients with central visual field radii greater than 30 degrees have visual acuities of 20/40 or better; 32% of patients with central visual field radii smaller than 10 degrees have visual acuity of 20/40 or better.

Humans↗
PubMed1990

Issues in the design of drug trials for AIDS.

Although the fundamental principles that drive the design, conduct, and analysis of clinical trials are as applicable to AIDS as to other diseases, there is no question that we have been confronted with unusually difficult challenges in studying therapeutic approaches in this disease area. Treatments are being developed that show great promise, but when investigated further some may be seen to offer no clinical benefit and others may do active harm through toxicity. A group of biostatisticians, meeting in association with the AIDS Clinical Trials Group (ACTG), has discussed and written a report on a number of issues, primarily related to principles of study design, with the goal of stimulating thought on new study designs and the timely implementation of well-designed trials to identify effective treatment strategies for HIV-infected populations. These issues include (1) progression of clinical trials through phases, (2) choices of outcomes, (3) breadth and complexity of clinical trials (eligibility criteria and "low-tech" trials, (4) alternative designs to be used in randomized trials, and (5) the concept of randomized clinical trials as a desirable option, both for patients and for science. The current HIV epidemic makes the requirements of obtaining valid scientific comparisons more important, not less so, but the challenge is to expedite this process.

Acquired Immunodeficiency Syndrome↗