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Biomedical subjects

M Halpern

Publications and source records attributed to M Halpern.

179 records · Page 10Linked to original sources
PubMed1966

The stability and control of conditioned noise aversion in the tilt cage.

Twenty-six rats were used to study the development of stable conditioned responding to terminate white noise (100 or 105 db) in a tilt cage apparatus. Preliminary work, with one end of the cage consistently associated with silence, demonstrated stability at a high level of cumulative noise-off time per session. Time spent at the noise-off cage end was unaffected by lay-off and showed adaptation to reversal of the cage end functions. Variability in reversal acquisition, insensitivity to stimulus intensity changes and persistence in remaining at one end of the cage in the absence of noise-termination contingencies indicated the need for more precise behavioral control. A schedule programming several reversals of the no-noise end at variable intervals within each session was developed. Performance on the latter schedule was characterized by stability of high noise-off times and also proved more sensitive than the preliminary method to stimulus intensity changes (55, 70, 100 db) as measured by both cumulated noise-off time and cage crossing rates. The ease of training combined with sensitivity to stimulus change and the lack of highly specific motor response requirements make this technique promising for use with animals potentially debilitated by drugs or surgical after-effects.

Animals↗
PubMedDate not supplied

Cost-effectiveness of long-term intrathecal morphine therapy for pain associated with failed back surgery syndrome.

A decision analytic study was conducted using computer simulation to project the outcomes in a simulated cohort of patients whose treatment for back surgery had failed. The objective of this study was to estimate the direct cost of intrathecal morphine therapy (IMT) delivered via an implantable pump relative to alternative therapy (medical management) over a 60-month course of treatment. IMT administered by way of an implantable pump can provide effective pain relief for selected patients whose less invasive treatment modalities have failed. Previous research suggested that a pump implant is less costly than alternative methods providing comparable analgesia for treatment exceeding 12 to 18 months. However, those analyses did not include the cost of complications or pump replacement. Scenarios representing the course of IMT, devised by a panel of experts, were represented as treatment pathways in a Monte Carlo simulation. Adverse event rates were drawn from published data supplemented by expert judgment. Direct costs were based on a health insurer paid claims perspective (direct costs) discounted at a 5% annual rate. The cost-effectiveness of IMT was calculated based on a report of 65% to 81% "good to excellent" pain relief relative to alternative (medical) management. With both adverse event probabilities and costs set at most likely (base case) values, the expected total cost of IMT over 60 months was $82,893 (an average of $1382 per month). In a sensitivity analysis, the best case (low adverse event rate, low cost) estimate was $53,468 ($891/mo), whereas the worst case (high adverse event rate, high cost) estimate was $125,102 ($2085/mo). Cost-effectiveness estimates ranged from $7212 (best case) to $12,276 (worst case) per year of pain relief. Results from a computer simulation designed to collect the costs not included in previous empiric research indicate that IMT appears to be cost-effective when compared with alternative (medical) management for selected patients when the duration of therapy exceeds 12 to 22 months.

Back↗
PubMedDate not supplied

Cancer pain management: barriers, trends, and the role of pharmacists.

OBJECTIVES: To describe barriers to optimal cancer pain management, activities that have been implemented in recent years to partially overcome these barriers, and the importance of the pharmacist's role in the cancer pain management process. SUMMARY: Cancer pain management remains a formidable challenge. Barriers in the United States include inadequate provider training; patients' reluctance to report pain; and deficiencies within the health care infrastructure, such as restrictive regulation of controlled substances and inadequate insurance coverage. Despite these barriers, recent efforts have raised awareness of the gap between suboptimal and optimal cancer pain management. These include: the development of guidelines (and the conduct of scientific studies) to educate providers about pain management or gaps in the cancer pain management process; regulation that has lessened provider restrictions in prescribing analgesics; the emergence of patient and provider advocacy groups; and the development of pain assessment instruments. Because of their clinical and pharmacologic expertise, pharmacists are crucial to the shaping and success of cancer pain management strategies in the United States today. CONCLUSION: Despite its high prevalence and the increasing awareness of the effects of pain on quality of life, cancer pain management remains secondary to treatment of the disease itself. Refining the cancer pain management process in the United States will depend on continued education and emphasis on pain assessment and a proactive approach to pain management, provider groups' effective collaboration with each other and with patients, and overcoming legal, regulatory, and cost barriers.

Neoplasms↗
PubMedDate not supplied

Cost of illness of epilepsy in the US: comparison of patient-based and population-based estimates.

PURPOSE: To analyze the direct medical costs associated with epilepsy in the US using a cost-of-illness analysis that incorporates both a patient-based approach and a population-based approach. METHODS: Patient-based or 'bottom-up' analysis relied on information provided by a panel of experienced epilepsy clinicians to determine the number and type of medical resources used by individuals with epilepsy. Population-based or 'top-down' analysis relied on cost estimates from a nationally representative sample in the 1987 National Medical Expenditure Survey. RESULTS: The average annual cost per individual in the patient-based analysis was $1,490. The average annual cost per individual in the population-based analysis was $1,510 with average yearly costs per adult of $1,480 and $1,740 per child. New cases of epilepsy are associated with costs of $362 million for the first year of treatment; existing cases of epilepsy are estimated to cost the US nearly $2 billion. CONCLUSIONS: The results of this study indicate incident cases are more than twice as expensive as prevalent cases, and the need to properly care for epilepsy patients is increasingly important in today's health care environment, where the emphasis is on providing effective treatments while simultaneously lowering the costs.

Adolescent↗
PubMedDate not supplied

Brush cytology and biopsy in the diagnosis of colorectal cancer. A comparison.

OBJECTIVE: To determine the usefulness of brush cytology of colorectal lesions as compared to biopsy examination. STUDY DESIGN: One hundred brushing cytologies and biopsies were performed on patients who underwent colonoscopic examination for different symptoms. The cytologic smears were classified into five cytologic diagnostic categories. The histologic diagnoses were adenocarcinoma, adenoma and nonneoplastic lesion. RESULTS: Twenty-six cases were cytologically positive for malignant cells, and all were histologically diagnosed as adenocarcinoma. Nineteen cases were suspicious for malignancy on cytology; histologically, eight of them showed adenocarcinoma. Two other cases proved to be adenocarcinoma in subsequent biopsies. Nine cases were adenomas, with severe dysplasia in five of them. Fourteen cases that were cytologically negative with minimal glandular atypia showed seven adenomas and seven nonneoplastic lesions on biopsy. Forty cases negative for malignant cells showed 19 adenomas and 21 nonspecific changes in the biopsy examination. CONCLUSION: Colonoscopic brushing cytodiagnosis is a sensitive technique for the detection of colorectal cancer. The combination of brushing cytology and biopsy improves the accuracy of diagnosis.

Adenocarcinoma↗
PubMedDate not supplied

Lymph node revealing solution: a new method for lymph node sampling: results in gastric adenocarcinoma.

Staging of gastric carcinoma depends on exact lymph node status. However, very small nodes are not easily found as they are obscured by the surrounding adipose tissue. The purpose of the present study was to demonstrate the usefulness of a Olymph node revealing solutionO (LNRS) in gastric cancer. The perigastric adipose tissue of ten OproblematicO cases of gastric carcinoma, in which <10 lymph nodes were found using the traditional method, was immersed in LNRS for 6-12 h. Subsequently, the lymph nodes stood out as white chalky nodules. They were excised and processed routinely. The traditional method yielded a total of 30 lymph nodes with a mean size of 6.69 +/- 3.43 mm. The LNRS revealed 89 additional nodes with a mean size of 3.03 +/- 3.43 mm, which was significantly smaller. The Node (N) stage was changed in four cases from Nx to N0, in one case from N1 to N2, and in one case from N0 to N2. LNRS seems to be the technique of choice for staging of patients with gastric adenocarcinoma in whom <10 lymph nodes were found with the traditional method and accurate staging was not possible.

Adenocarcinoma↗
PubMedDate not supplied

Corynebacterium diphtheriae threats in cancer patients.

The aim of this study was to determine the bacteriological properties of Corynebacterium diphtheriae strains isolated from bronchiole washing and cancer lesions. Bacteriological characterization included fluorescence/double sugar urease (King/DSU) screening tests, pyrazinamidase (PYZ), CAMP-reactions and radial immunodiffusion toxigenicity assay. Microorganisms produced fluorescence under ultraviolet light and were catalase positive; urea and aesculin hydrolysis negative; fermentation of glucose, maltose and sucrose and no fermentation of mannitol and xylose; PYZ and CAMP reaction negative. The API-Coryne system was used for bacterial preliminary identification at local hospital laboratory and produced numerical profiles 1010325 and 0010325 for sucrose positive C. diphtheriae var. mitis (nitrate positive) and C. diphtheriae var. belfanti (nitrate negative), respectively. The hemagglutination, adherence to glass and polystyrene assays evaluated adhesive characteristics. Strains were toxigenic and able to adhere to glass, polystyrene and human erythrocyte surfaces (titer 4). C. diphtheriae strains isolated from cancer patients expressed adhesive characteristics similar to strains isolated from immunocompetent hosts. Circulation of toxigenic C. diphtheriae continues to present a threat for children and adults including patients with cancer in hospital environment. Laboratories should remain alert to the possibility of isolation of diphtheria bacilli from adults with neoplastic disease.

Adult↗
PubMedDate not supplied

Localized amyloid tumor of the tongue. A case report and review of the literature.

Amyloid is usually deposited in the tongue, as a part of generalized amyloidosis. Isolated localized amyloidosis of the tongue is relatively rare. We report such a case which presented with glossodynia and glossopyrosis and was thought clinically to represent median rhomboid glossitis. Histologically the amyloid stained positively with Congo-red giving green birefringence under polarized light, was not abolished after permanganate pretreatment and did not react immunohistochemically for amyloid A, beta 2 microglobulin and transthyretin.

Adult↗
PubMedDate not supplied

Effect of chronic inhalation of sulfuric acid mist upon mucociliary clearance from the lungs of donkeys.

The effect of chronic inhalation exposures to sulfuric acid mist upon mucociliary clearance from the lungs was studied, using the donkey as an analogue for man. Four animals were exposed 1 hr/day, 5 days/week, for 6 months. The mean mass concentration of acid mist was 102 microgram/m3 for two animals, and 106 microgram/m3 for the other two. The mass median aerodynamic diameter was approximately 0.5 micrometer. Clearance was monitored by serial, external in vivo measurements of the retention of an insoluble, radioactively tagged ferric oxide aerosol which was inhaled following exposure to the acid mist. Bronchial clearance became erratic within the first week of exposure; rates were significantly different, usually slower than control on many test days, although the degree of response varied among the four animals. Two animals exhibited a sustained impairment of clearance towards the end of the 6-month exposure period and continued to have erratic clearance during a 3-month follow-up period. No changes in the regional deposition of the ferric oxide occurred during the course of the study in any of the animals. It is proposed that alterations in bronchial mucociliary clearance may be an early, if not the first, physiologic effect resulting from the inhalation of sulfuric acid mist, and this may be a factor in the pathogenesis of chronic bronchitis in populations exposed to the sulfur oxide-particulate-complex in the ambient air, which often includes sulfuric acid.

Aerosols↗
PubMedDate not supplied

Nucleolar organizer regions in breast cytology material.

OBJECTIVE: To evaluate the presence of nucleolar organizer regions (NORs) by the argyrophil NOR (AgNOR) technique on scrape cytology on breast lumps. STUDY DESIGN: The study group consisted of 112 breast lumps that were sent for frozen section and included fibrocystic disease (52 cases), fibroadenomas (15 cases) and carcinomas (45 cases). Scrape cytology was performed on each case, and the number of AgNOR dots was recorded for 50 cells and the mean value calculated. RESULTS: The mean AgNOR counts were statistically significantly higher in malignant lesions in comparison to either fibroadenomas or fibrocystic changes. CONCLUSION: The AgNOR technique could be of use in cytologic material as an adjunct to fine needle aspiration of breast lesions.

Breast Neoplasms↗
PubMedDate not supplied

School-based screening for tuberculous infection. A cost-benefit analysis.

OBJECTIVE: To compare tuberculin screening of all kindergartners and high school entrants (screen-all strategy) vs screening limited to high-risk children (targeted screening). DESIGN: Decision, cost-effectiveness, and cost-benefit analyses. SETTING AND SUBJECTS: Students in a large urban and rural county. DEFINITIONS: High risk of tuberculosis infection was defined as birth in a county with a high prevalence of tuberculosis. Low risk was defined as birth in the United States. OUTCOME MEASURES: Tuberculosis cases prevented for 10, 000 children screened. Net costs, net cost per case prevented, benefit-cost ratio, and incremental cost-effectiveness. RESULTS: The screen-all strategy would prevent 14.9 cases per 10,000 children screened; targeted screening would prevent 84.9 cases per 10,000 children screened. The screen-all strategy is more costly than no screening; the benefit-cost ratio is 0.58. Targeted screening would result in a net savings; the benefit-cost ratio is 1.2. Screening all children is cost saving only if the reactor rate is 20% or greater. The cost per additional case prevented for screening all children compared with targeted screening (+34 666) is more than twice as high as treatment and contact tracing for a case of tuberculosis (+16 392). CONCLUSIONS: Targeted screening of schoolchildren is much less costly than mass screening and is more efficient in prevention of tuberculosis.

Adolescent↗