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Biomedical subjects

G F Anderson

Publications and source records attributed to G F Anderson.

At least 91 records · Page 5Linked to original sources
PubMed1991

Effect of decentralization and partial outflow obstruction on cholinergic receptors in urinary bladder of rabbit.

In this study we have examined the cholinergic receptor density on the detrusor smooth muscle from rabbits with decentralized autonomous bladders and animals with partial outlet obstructions using (3H) quinuclidinyl benzilate ([3H] QNB). Decentralized spinal bladders were obtained from rabbits made paraplegic by a twenty-minute ischemic lesion to the lumbar and sacral spinal cord. Bladder tissues from these rabbits were studied from one, two, five, and nine-day intervals after the ischemic lesion. The affinity of the muscarinic binding sites for (3H) QNB was virtually unchanged at any of the time intervals, while the total Bmax was significantly reduced at one and two days but recovered to normal levels by the fifth and ninth day after the ischemic lesion, provided the bladder had been effectively manually emptied on a regular basis. In a parallel study animals with a partial outlet obstruction or spinal animals with marked bladder distention at the time of sacrifice showed that the cholinergic receptor density was significantly reduced.

Animals↗
PubMed1991

A surplus of physicians in Israel: any lessons for the United States and other industrialized countries?

In Israel, there is a consensus that there is a surplus of physicians. An examination of the Israeli situation may suggest some responses that will be taken by policy makers and physicians in the United States and other industrialized countries as the supply of physicians continues to increase. Specifically, we examine the impact of rising physician supply on the geographic distribution of physicians in Israel, the length of the training period for residency programs, the interaction between physicians and other professionals, and the level of physician incomes compared to other Israeli workers.

Delivery of Health Care↗
PubMed1991

Electromechanical effects of menadione on isolated rat heart in relation to oxidative stress.

Although Ca2+ overloading has been observed in hepatocytes and in the isolated liver treated with 0.2 mM menadione, it has not been determined if menadione has similar effects on cardiac tissue and, if so, whether Ca2+ overloading leads to cardiac contracture, and if such an event results from plasma membrane peroxidation initiated by oxidative stress. The present study reveals that when the isolated heart is perfused with 0.2 mM menadione for 30 min, it shows Ca2+ overloading, which can not be reversed even after 30 min of drug-free perfusion. The time courses of glutathione, ethane, and LDH release from the hearts do not show a parallel pattern of abnormality between 30 and 60 min, indicating that contractile failure precedes the development of lipid peroxidation or plasma membrane disintegration. The evidence that the plasma membrane of menadione-treated rat cardiac tissue remains intact is supported by the observation that the resting membrane potential of the atrium remains virtually unchanged during the 30 min of drug exposure and then gradually falls (-67 +/- 3.1 vs. -76 +/- 2 mv) only during the last 10 min of the drug washout. Interestingly, even after the atria are treated with menadione for 30 min and followed by washout of 30 min, and have shown calcium overloading, as evidenced by contracture, they are still capable of generating action potentials in response to electrical field stimulation.

Animals↗
PubMed1991

Blood transfusion costs: a multicenter study.

The cost of delivering a unit of blood (whole blood or red cells) to a hospitalized patient was examined in 19 United States teaching hospitals. The average hospital acquisition cost was calculated by using the prices charged by regional blood centers for blood products. To this cost was added an estimate of costs incurred by hospitals for handling, testing, and administering blood. Across study sites, the average hospital cost per unit transfused was $155 and the average charge to the patient was $219. Acquisition cost, the price that hospitals pay for blood, was 37 percent of the total cost to the hospital; the other 63 percent of the hospital cost included costs for blood bank handling (13%), laboratory tests (43%), and blood administration (7%). Significant variations in blood transfusion cost were found within our sample. Most of the variability can be attributed to geographic location of the blood supply source, type of red cell product transfused, prices charged by blood transfusion services, and the frequency of laboratory tests. The results of this transfusion cost study may be helpful in determining the costs of health care delivery, especially when blood transfusions are indicated.

Blood Transfusion↗
PubMed1991

Accuracy of Medicare claims data for estimation of cancer incidence and resection rates among elderly Americans.

To explore the reliability of Medicare Part A claims data for clinical and health services research related to the care of patients with cancer, the authors compared estimates of the incidence of and resection rates for cancer of the breast, colon, and lung derived from analysis of Medicare Part A data versus data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Incidence rates of breast, colon, and lung cancer estimated from Medicare Part A data were within 6% of estimates derived from SEER data. Resection rates estimated from Medicare Part A data, in contrast, were 12% to 27% lower than resection rates based on SEER data. This discrepancy is not explained by variations in practice between regions participating in versus those not participating in the SEER registries but may be due to undercoding of surgical procedures in Medicare Part A data. This analysis suggests that Medicare data can provide useful insights into the care of patients with cancer, but research regarding inpatient procedures employed in management of cancer should be based on analysis of Medicare Parts A and B data combined.

Abstracting and Indexing↗
PubMed1991

Use of Medicare claims data to evaluate outcomes in elderly patients undergoing lung resection for lung cancer.

OBJECTIVE: To estimate, using Medicare claims data, the outcomes in elderly Americans undergoing lung resection for lung cancer. DESIGN: We used discharge diagnosis and procedure codes in 1983 to 1985 Medicare hospital (part A) claims records to identify patients who underwent lung resection for lung cancer; we assessed perioperative, one-year, and two-year survival using Medicare enrollment file data. PATIENTS: From a nationally random sample of 1,138,000 Medicare beneficiaries over 65 years of age, we identified 1,290 individuals who fulfilled our definition for lung resection for lung cancer. MEASUREMENTS AND MAIN RESULTS: Overall perioperative (30-day) mortality was 7.4 percent. Postoperative survival at one and two years was 69 percent and 54 percent, respectively. Male sex, older age, and pneumonectomy, as opposed to a lesser procedure, were associated with reduced perioperative and one-year and two-year survival. The adverse effect of advanced age on one-year and two-year survival following lung resection was not explained by the lower life expectancy of older individuals. CONCLUSIONS: Medicare claims data can be used to estimate likely outcomes for elderly patients undergoing surgery for lung cancer. Expected outcomes vary with the patient's age, sex, and the type of surgical procedure performed.

Aged↗
PubMed1991

All-payer ratesetting: down but not out.

In the United States, when the cost-containment paradigm shifted from regulation to competition, all-payer hospital ratesetting went out of favor. After reviewing the published literature and supplementing the existing literature with more current information, the author concludes that all-payer ratesetting is able to meet its multiple objectives of cost containment, reduction of the amount of cost shifting, improvement of access to the uninsured, and increased productivity. At the same time, all-payer ratesetting has not stifled the diffusion of competitive health care systems or new technology, and any impact on length of stay, admissions, and quality of care is small, if it exists at all.

Cost Allocation↗
PubMed1990

Impact of claims data research on clinical practice.

Despite their potential utility, clinicians are skeptical about claims data as a substrate for clinical research. Clinician's concerns are centered on two issues-the quality of the data and the fairness of comparisons that are made. To increase the impact of claims data research on clinical practice, several strategies should be pursued.

Humans↗
PubMed1990

Risk reduction from low osmolality contrast media. What do patients think it is worth?

Decisions regarding the use of and reimbursement for new medical technologies frequently involve complex cost-quality trade-offs. Among physicians, hospital administrators, and insurers, interindividual variation in the value of benefits attributable to these technologies often leads to conflicting opinions about their appropriate use. Although society now encourages patient involvement in such decisions, few methods for obtaining patient valuations have been developed and systematically applied. In order to assess patient valuations of a particular new technology, low osmolality contrast media (LOM), a survey of 100 outpatients was conducted. Participants were asked about their willingness to pay (WTP) for the benefits of this expensive medical technology. Of the 95 subjects who completed the study questionnaire, a majority were unwilling to pay the minimum extra per procedure cost of LOM ($50) in return for a reduced risk of minor side effects alone (pain, nausea, hives, and flushing). For a reduced risk of both major side effects (death, renal insufficiency, severe allergic reaction, and cardiac arrhythmia) and minor side effects, the median WTP was $50; patient income and education were directly associated with WTP $50 or more. We conclude that similar WTP surveys may be helpful in addressing other difficult cost-quality issues.

Adult↗
PubMed1990

Circadian rhythms of human pineal melatonin, related indoles, and beta adrenoreceptors: post-mortem evaluation.

Human pineal glands obtained from 77 post-mortem sources from various age groups and times of death were used to examine the 24-hour cycle of serotonin (5-HT), melatonin, N-acetylserotonin (NAS), and beta adrenoceptor density. Pineal glands were divided sagittally and a single half was used to measure 5-HT, NAS, and melatonin concentrations, while the remaining half from the same gland was employed to assess changes in the density of beta adrenoceptors on partially purified membranes. The results show that density of pineal beta adrenoceptors was relatively constant between midnight and 18.00 h and became significantly higher between 18.00 and 20.00 h as measured by ligand saturation binding experiments using (125-I) iodocyanopindolol. The receptor affinity of all of the samples assayed remained in relatively narrow range near 58 pM and only changes in the relative receptor density were apparent. The up-regulation of receptors coincided with an increase in the concentration of 5-HT that began to rise between 16.00 and 20.00 h and became maximal between 20.00 and midnight. NAS, the immediate precursor of melatonin, was also at maximal levels between 20.00 h and midnight. Both 5-HT and NAS began declining after midnight and this change corresponded to the maximal pineal gland concentration of melatonin between midnight and 4.00 h. It is therefore suggested that the up-regulation of beta adrenoceptors noted during the late afternoon and early evening hours corresponds to the increased synthesis of 5-HT and the subsequent conversion to NAS. These events are followed by the highest accumulation of melatonin after midnight and represent the synthesis of melatonin from its precursor NAS in a sequential pattern.

Adolescent↗
PubMed1990

Setting payment rates for capitated systems: a comparison of various alternatives.

Numerous proposals have been suggested to revise the current adjusted annual per capita cost (AAPCC) method for paying HMOs in the Medicare program. Several evaluations of the various alternatives conclude that including a prior utilization variable is the most promising alternative. In this paper, using statistical and other criteria, we compare the current AAPCC method with three different prior utilization models. The results suggest that all three prior utilization models can predict expenditures for either individuals or a group--drawn from a cross section and a risk selected sample of aged Medicare beneficiaries--more accurately than the AAPCC method. Of the three prior utilization measures, Payment Amount for Capitated Systems (PACS) predicts actual expenditures most accurately.

Capitation Fee↗
PubMed1989

Circumcision.

There are no absolutes regarding circumcision, and the decision to circumcise a child as a newborn or otherwise must be made after carefully weighing the alternatives to, and risks and benefits of, this common surgical procedure. These alternatives, risks, and benefits must be fully explained to parents considering circumcision, and informed consent must be obtained. In well-trained, experienced hands, circumcision is a safe procedure that effectively eliminates proven problems such as cancer of the penis, and may eliminate the problems of increased risk of urinary tract infection and sexually transmitted diseases.

Anesthesia, Local↗
PubMed1988

Cost and procedure implications of thrombolytic therapy for acute myocardial infarction.

A computer model was developed to analyze the costs to Medicare and the potential procedure volume associated with alternative strategies for treatment of acute myocardial infarction. The expected cost per case to Medicare for initial hospitalization was approximately $7,200 for conventional treatment, $7,900 for treatment with intravenous streptokinase and $8,400 for treatment with recombinant tissue-type plasminogen activator (rt-PA). The expected cost per case for use of streptokinase or rt-PA in combination with cardiac catheterization performed either emergently or at 48 h was in excess of $11,000. These cost estimates do not reflect the cost of thrombolytic drugs themselves because Medicare has not adjusted its hospital payment rates to take account of such costs. Although both streptokinase and rt-PA will increase costs to Medicare for hospitalizations for acute myocardial infarction, both agents will do so at a reasonably low cost per additional life saved--between $50,000 and $60,000. Emergency and 48 h catheterization strategies are considerably less cost-effective. Regarding procedures, this model suggests that for every 1,000 patients treatment with streptokinase will result in an additional 76 coronary angioplasty procedures and 26 coronary artery bypass operations, whereas treatment with rt-PA will result in an additional 122 angioplasty procedures and 43 bypass operations compared with conventional treatment. Thrombolytic treatment is thus likely to increase substantially the volume of cardiac catheterization, coronary angioplasty and coronary artery bypass surgery performed in the United States.

Computers↗
PubMed1988

Wilms tumor and the VATER association.

We describe an infant with the VATER association in whom a Wilms tumor was noted when she was 5 months old. The lower pole tumor arose near the pelvis and grew into an adjacent calix producing a cystic and solid mass with numerous papillary projections resembling sarcoma botryoides. Histopathologically, the tumor was a classical Wilms tumor but it was unusual in that the papillary projections of the tumor were covered by intestinal-like epithelium, which was interpreted as metaplastic urothelium. The margins were free of tumor and the patient is being treated according to the National Wilms Tumor Study Protocol for stage I lesions. She is currently without evidence of recurrence.

Abnormalities, Multiple↗
PubMed1988

The response of autonomic receptors to castration and testosterone in the urinary bladder of the rabbit.

The effects of castration and testosterone on the autonomic receptor density and contractility in the urinary bladder smooth muscle of male rabbits were compared to untreated animals. Four groups of rabbits were studied over a similar time span with Group 1 animals serving as the untreated controls. Two groups (Groups 2 and 3) were castrated 28 days prior to sacrifice, Group 2 animals received corn oil for 14 days, and Group 3 animals received testosterone, 10 mg./day, for 14 days. The Group 4 animals were non-operated and received testosterone 10 mg./day for 14 days. Ligand saturation binding studies for alpha adrenoceptors in the bladder base and proximal urethra were performed with [3H]dihydroergocryptine ([3H]DHE). Muscarinic cholinergic receptors (MChR) were assayed with [3H]quinuclidinyl benzilate ([3H]QNB) and beta adrenoceptors with [125I]iodocyanopindolol ([125I]CYP) on the detrusor smooth muscle. Castrated Group 2 animals showed no significant change in receptor density with either [3H]QNB or [125I]CYP in detrusor muscle, but did exhibit a significant reduction (59%) of alpha adrenoceptors in the bladder base-urethra. The testosterone treated castrate and testosterone treated non-operated animals had significant increases in the MChR density, but no change in the alpha adrenergic, or beta adrenergic receptor density as compared to untreated controls. Cumulative dose response contractile studies were performed with carbachol on detrusor muscle strips and with phenylephrine on bladder base strips in isolated organ baths. The contractile studies on muscles from Groups 1, 2 and 3 showed no change in the ED50 or maximal contractile strength between control, castration or testosterone treated castrated animals. The ratio of wet bladder weight as compared to total body weight between each of the treatment groups showed a slight increase in both of the testosterone treatment groups. It was concluded that castration down regulates the alpha adrenergic receptors of the bladder base, while testosterone treatment increases the density of MChRs, and increases the ratio of the bladder to total body weight. Although no contractile changes were observed in the bladder base tissue it is conceivable that longer chronic testosterone deficits might ultimately affect the bladder outlet resistance in the male because of the reduced alpha adrenergic receptor density.

Animals↗