Cross-national comparisons of health systems using OECD data, 1999

This paper presents selected components of the most recent (1999) Organization for Economic Cooperation and Development (OECD) Health Data. Previous trends in spending for health care, supply and use of health care resources, and health status are updated for the thirty industrialized countries in the OECD. In 1999 the United States spent 53 percent more on health care than any other OECD country spent. The paper reviews two possible reasons for the difference: economic development and population aging. It discusses spending, supply, and utilization for specific categories of health care services: pharmaceuticals, physicians, hospitals, and high-technology services. The paper concludes with a consideration of the strengths and weaknesses of using OECD data to compare health systems.     

On the occurrence of Leydig cell tumors in the F344 rat

Dunning began inbreeding, what is now the Fischer F344 rat, in 1931. Because of her publications showing a low incidence of spontaneous tumors to 35 months of age, we selected the F344 rat for most of the studies in the National Cancer Institute (NCI) Bioassay Program, beginning in 1964. We were surprised by the finding that untreated male F344 rats displayed a high incidence of Leydig cell tumors of the testes beginning at about 17 months of age. The key difference between the results of Dunning and the NCI Bioassay Program was that her animals were retired breeders, whereas the NCI studies utilized virgin rats. The question of breeding was, therefore, examined as a possible protective factor.Groups of male F344 CDF/Crl rats were kept as virgin animals, or permitted access to bilaterally tube ligated female F344/Crl rats that were replaced twice over a 52-week period. At that time, all males from both groups were housed three per cage to 85 weeks when they were killed in a CO(2) atmosphere and necropsied. Sections were prepared from the fixed tissues, stained and studied by histopathology. The results were evaluated by appropriate statistical methods.Virgin and sexually active F344 rats displayed monolateral or bilateral Leydig cell tumors. There was no statistical difference between the two groups.Despite the early difference between breeding and virgin F344 rats, a control experiment failed to disclose an effect of sexual activity on the occurrence of Leydig cell cancers. This disease displays some difference in incidence in various parts of the world, with the higher socioeconomic groups having a greater incidence. Etiological factors on the occurrence of this disease in animals and in humans remain to be discovered.     

Isolated myelosarcoma in children--update and review

Primary myelosarcomas, also called leukemia cutis, granulocytic sarcomas or chloromas, are rare extramedullary manifestations of acute myeloid leukemia (AML) which precede bone marrow involvement. Skin infiltration was the most frequent localization associated with a myelomonocytic differentiation. Although first remission was achieved by most children, risk of relapse seemed to be increased. This might be caused by the specific biology of myelosarcomas, but also may be the result of delayed or reduced treatment. During the AML-BFM-studies 87/93/98 (11/1987-7/2000) 37 children with isolated myelosarcomas were diagnosed. Eighteen of the 37 patients survived with a 5-year overall survival estimation of 0.54+/-0.09 compared to 0.59+/-0.02; p(log rank) = 0.94. However, reduced or delayed treatment in 17 children led to an increased relapse rate of 71% compared to 35% in children treated soon after diagnosis. The 5-year overall survival in these patients was 0.41+/-0.11. According to our experience and review of the literature, an early diagnostic workup is needed in children with unusual skin lesions or tumors, considering myelosarcoma as primary manifestation of AML. Intensive AML-specific chemotherapy is generally recommended soon after diagnosis.     

Radio-frequency tumor ablation: internally cooled electrode versus saline-enhanced technique in an aggressive rabbit tumor model

PURPOSE: To compare two methods of radio-frequency (RF) ablation, saline enhancement technique and internally cooled electrodes, for the treatment of small breast cancers in an animal model--highly aggressive VX2 rabbit tumors surrounded by adipose tissue. MATERIALS AND METHODS: Twenty-seven tumors were implanted into retroperitoneal fat of 14 New Zealand White rabbits. RF ablation was performed with ultrasonographic (US) guidance after tumors had grown to 15 mm. Fourteen tumors in seven animals were treated with internally cooled electrodes (30-mm-tip single electrode, 60 W, 10 min); 13 tumors in seven animals, with saline enhancement (0.5 mL/min of saline, 25-mm tip, 30 W, 10 min). Autopsy and histopathologic assessment were performed 3 weeks after therapy. RESULTS: Real-time US of RF ablation was not possible with either method because of obscuration by the increasing hyperechogenicity of the tumor and the surrounding adipose tissue. Equivalent efficacy was demonstrated with the two methods. Significantly greater complications were observed with the saline technique: Free retroperitoneal fluid was detected in one of seven animals with internally cooled electrodes and in all seven animals with saline enhancement (P <.01). Damage to remote structures such as the kidney, spine muscle, and skin was observed at autopsy in one of seven animals with internally cooled technique versus five of seven with saline enhancement (P <.01). CONCLUSION: Given a lower complication rate and similar treatment efficacy in an animal tumor model, internally cooled RF electrode may be advantageous to adjuvant saline infusion for the minimally invasive treatment of breast tumors.     

Peripheral neuropathy in chronic venous insufficiency

Chronic venous insufficiency (CVI) of the lower legs may cause tissue damage, but involvement of peripheral nerves is uncertain. We examined 30 patients with CVI and 20 healthy controls using motor and sensory nerve conduction studies, vibration testing and thermotesting, quantitative sudomotor axon-reflex test, and laser Doppler flowmetry. Subjects with possible confounding factors for peripheral neuropathies were excluded. Prolongation of distal motor latency of the peroneal nerve (median, 5.4 versus 4.5 ms; P = 0.02), increased limits for warm (9.60 degrees C versus 5.20 degrees C; P = 0.016) and cold detection (3.45 degrees C versus 1.55 degrees C; P = 0.016) and reduced vibration sense (2.8925 versus 1.1075; P < 0.008) were found. The results demonstrate a disturbance of A-alpha fibers, A-beta fibers, A-delta fibers, and thermoafferent-C fibers, possibly induced by ischemia due to venous microangiopathy and increased endoneurial pressure. Analogous to neuropathic ulcers in diabetes, the CVI-associated neuropathy may also be a cofactor in the development of venous ulcers.     

Normalization of elevated CD4-/CD8- (double-negative) T cells after thymectomy parallels clinical remission in myasthenia gravis associated with thymic hyperplasia but not thymoma

T-cell-dependent B-cell help is likely to be of major importance in the pathogenesis of myasthenia gravis, but mechanisms provoking a pathological anti-acetylcholine receptor (AChR) response are poorly understood. We report on the dysregulation of recently identified CD4-/CD8- (double-negative) T cells (DN T cells), which have been shown to participate in immunoregulation and antibody augmentation. Compared with healthy controls, significantly increased frequencies of DN T cells were found in the blood of myasthenia gravis patients with lymphofollicular hyperplasia. After thymectomy, however, normalization in the number of these cells was seen in parallel with clinical improvement and reduction in anti-AChR antibody titers. The effect of thymectomy was observed irrespective of adjuvant treatment and held true for up to 4 years of follow-up. In marked contrast, frequencies similar to control values were found in myasthenia gravis patients with thymoma, with thymectomy having no further reducing effect. These data indicate that CD4-/CD8- T cells not only participate in the pathogenesis of myasthenia gravis but also correlate with disease activity and histological findings.     

Kyphoplasty in the treatment of osteolytic vertebral compression fractures as a result of multiple myeloma.

PURPOSE: We prospectively evaluated the safety and efficacy of kyphoplasty in the treatment of osteolytic vertebral compression fractures resulting from multiple myeloma. The principle symptoms in multiple myeloma result from bone destruction, especially the spine. Kyphoplasty is a new technique that involves the introduction of inflatable bone tamps (IBT) into the vertebral body. The purpose of the IBT is to restore the vertebral body back toward its original height, while creating a cavity that can be filled with highly viscous bone cement. PATIENTS AND METHODS: Fifty-five consecutive kyphoplasty procedures were performed in 18 patients with osteolytic vertebral compression fractures resulting from multiple myeloma. Cement leakage and any complications were recorded. Early objective analysis was made by comparing preoperative and latest Short Form 36 Health Survey scores. Height restoration was estimated by measuring vertebral height on lateral radiographs. RESULTS: The mean age of patients was 63.5 years, mean duration of symptoms was 11 months, and mean follow-up was 7.4 months. There were no major complications related directly to use of this technique. On average, 34% of height lost at the time of fracture was restored. Asymptomatic cement leakage occurred at two (4%) of 55 levels. Significant improvement in SF36 scores occurred for Bodily Pain (23.2 to 55.4, P =.0008), Physical Function (21.3 to 50.6, P =.0010), Vitality (31.3 to 47.5, P =.010), and Social Functioning (40.6 to 64.8, P =.014). CONCLUSION: Kyphoplasty was efficacious in the treatment of osteolytic vertebral compression fractures resulting from multiple myeloma. Kyphoplasty is associated with early clinical improvement of pain and function as well as some restoration of vertebral body height.     

Analysis of chimerism during the early period after allogeneic peripheral stem cell transplantation

As there are few reports on early evaluation of chimerism, we assessed fluorescence short tandem repeats (STR) by polymerase chain reaction (PCR) assays to analyse donor and recipient characteristics at early time points after peripheral stem cell transplantation (PBSCT). Peripheral blood of 13 patients was analysed in 1- to 2-day intervals starting from the day of PBSCT. Donor and recipient allelic patterns were determined by a commercially available multiplex STR assay that simultaneously evaluates four or five gene loci. Mixed chimerism appeared in all patients during days 1-9 after transplantation and preceded haematologic engraftment for 3-12 days. Even patients without myeloablative conditioning therapy (n=4) revealed donor allelic patterns within 1-5 days. Nine patients changed during the following days to a complete donor allelic pattern and had an uncomplicated post-transplant disease course. Four patients did not consistently retain complete donor chimerism; two of them relapsed within the next 3 months, one died from septicemia within 7 days, and the fourth, transplanted for aplastic anaemia, is still in complete remission. Overall, STR analysis using a simple and comparatively cheap multiplex system permits the detection of chimerism very early after transplantation and may provide relevant information that correlates with the clinical follow-up.