Changes in CT utilization between 1981 and 1984: implications for Medicare payment for MR imaging under the prospective payment system

In the absence of data on current or likely patterns of use of magnetic resonance (MR) imaging, use of computed tomography (CT) at one institution in 1981 and 1984 was analyzed to provide data relevant to current federal deliberations regarding Medicare payment for inpatient MR imaging. Between 1981 and 1984 inpatient CT utilization increased 59%, primarily due to a 265% increase in body CT. In 1984 inpatients who underwent at least one CT procedure were as likely to undergo more than one procedure as to undergo only one. CT procedures were performed in a high proportion of diagnosis-related groups (DRGs), with more than one-half of head CT procedures performed in non-neurologic DRGs. Given the similarities between clinical applications of CT and MR imaging, these findings regarding CT utilization have the following implications: (a) a delay in recalibration of DRG payment rates may not take account of expected growth in utilization of MR imaging, (b) a DRG "add-on" for MR imaging should reflect the likelihood that more than one MR imaging procedure will be performed in many hospitalizations, and (c) adjustments in DRG payments for MR imaging should not be limited to the 35 neurologic DRGs.     

Quality assessment of randomized controlled trials of contrast media

Numerous randomized controlled trials (RCTs) have been conducted to define the relative benefits of low-osmolality contrast media (LOM) and high-osmolality contrast media (HOM). Because of the clinical and economic significance of the conclusions drawn from these RCTs, the authors used a standardized instrument to evaluate the quality of study design and data analysis of 100 RCTs published between 1982 and 1987 that compared LOM and HOM. The mean quality score (+/- standard deviation) was 39 +/- 12 (maximum possible score, 100). The largest number of patients studied in any RCT was 435; the smallest was five. A majority of the RCTs received high scores on three attributes of quality, intermediate scores on seven, and low scores on nine. These results underscore the difficulty of designing, performing, analyzing, and reporting high-quality RCTs. Nevertheless, limitations in study design and data analysis need to be considered when interpreting results of these RCTs. Future RCTs comparing LOM and HOM should be performed with greater attention to basic elements of good study design and data analysis.     

Comparison of quantitative cDNA-PCR with the branched DNA hybridization assay for monitoring plasma hepatitis C virus RNA levels in haemophilia patients participating in a controlled interferon trial

The branched DNA (bDNA) assay was compared with a semi-quantitative cDNA-polymerase chain reaction (cDNA-PCR) assay for monitoring HCV RNA levels in plasma in 17 haemophilia patients participating in a controlled a-interferon trial. Good correlation between the HCV RNA levels as detected by the two assays was observed, with a correlation co-efficient of 0.83 (P < 0.0001) and 0.90 (P < 0.0001) at week 0 and 24, respectively. Hepatitis C virus RNA (HCV RNA) levels could be assessed with the bDNA assay in 14/17 (82 percent) HCV cDNA-PCR positive pre-treatment samples. The bDNA assay apparently failed to detect low viral titres. (riterferon treated patients (n = 11) showed either a complete response, being a large reduction in HCV RNA level to below the detection limit of the HCV cDNA-PCR assay (6/11) or no significant reduction in HCV RNA level (5/11). A “partial” virological response was not observed. The changes in HCV RNA plasma levels in non-responders during interferon (IFN) treatment were similar to the (small) natural fluctuations in viral load observed in controls (untreated patients). Although the bDNA assay was not as sensitive as cDNA-PCR, given its user friendliness and quantitative results, it is concluded that it is a useful test for monitoring HCV RNA levels in patients treated with interferon. However, patients who are non-reactive in the bDNA assay have to be retested by cDNA-PCR because low viral titres are not detected by the bDNA assay. © 1994 Wiley-Liss, Inc.     

Impact of Fibroscan on management of chronic viral hepatitis in clinical practice

Background. Liver stiffness measurement (LSM) using Fibroscan® is an increasingly popular non-invasive me¬thod for quantifying liver fibrosis in patients with chronic viral hepatitis. We aimed to explore potential im¬pact of Fibroscan® on clinical management.Material and methods. 133 patients with chronic hepatitis B (HBV, n = 75) or C (HCV, n = 58) underwent Fibroscan® measurement. LSM results were compared with li-ver biopsy results, ultrasound, and APRI-scores, and the impact of LSM on clinical management was evalua¬ted.Results. LSM results indicated fibrosis stage F0-F1 in 84 patients (63%), F2 in 28 (21%), F3 in 8 (6%), and F4 in 13 patients (10%). Nineteen patients had liver biopsies within one year of LSM. In ten patients, LSM and biopsy showed the same fibrosis stage, in 8 there was one stage difference, and in 1 three stages di¬fference. Ultrasound only showed cirrhosis in three patients, who all exhibited advanced cirrhosis at LSM. There was a statistically significant, but weak correlation between LSM results and APRI scores (r = 0.31, p-value < 0.001). LSM results changed clinical management in 39% of patients (55 cases): in 15 patients antivi¬ral treatment was indicated, in 21 patients surveillance for hepatocellular carcinoma was indicated, and 19 successfully treated hepatitis C patients could be discharged from clinical follow-up in absence of severe fibrosis or cirrhosis.Conclusion. LSM appears to be a valuable non-invasive tool to manage patients with chronic viral hepatitis in clinical practice.     

HIV controllers exhibit potent CD8 T cell capacity to suppress HIV infection ex vivo and peculiar cytotoxic T lymphocyte activation phenotype

Some rare HIV-1-infected individuals, referred to as HIV controllers (HIC), have persistently undetectable plasma viral load in the absence of therapy. This control of HIV-1 replication has been associated with a strong, multifunctional specific CD8(+) T cell response. However, no direct link between this immune response and the control of viremia has so far been provided. We investigated parameters of specific CD8(+) T cell response and in vitro susceptibility to HIV-1 infection in 11 HIC. We found high frequencies of HIV-specific CD8(+) T cells. Interestingly, these cells expressed the activation marker HLA-DR but not CD38. This unique phenotype differentiates HIV-specific CD8(+) T cells from HIC and noncontroller subjects and likely reflects a high potential to expand upon exposure to antigen and a capacity to exert effector functions. Accordingly, although CD4(+) T cells from HIC were fully susceptible to HIV-1 superinfection, their CD8(+) T cells effectively suppressed HIV-1 infection. Remarkably, this potent anti-HIV activity was observed without prior stimulation of CD8(+) T cells. This activity was not mediated by secreted inhibitory factors but was due to the elimination of infected CD4(+) T cells and was observed only with autologous CD4(+) T cells, indicating an HLA-restricted cytotoxic mechanism. This constitutive antiviral capacity of CD8(+) T cells could account for the control of viral replication in HIC.     

Product choice and haemophilia treatment in the Netherlands

In the Netherlands, there is a free choice of product for the treatment of haemophilia. Which product is chosen depends on the following considerations: medical, psychological, availability of clotting products, economics and government guidelines. Since the introduction of recombinant product in 1995, the percentage of Dutch patients treated with it has increased from 8% in 1995 to 20% in 1998. In 1999, an average of 48% of patients visiting the Van Creveldkliniek were treated with recombinant product. Children are more often treated with recombinant product than adults; 93% of children between 0 and 5 years, 53% of children between 6 and 20 years and 40% of adults are treated with recombinant product.     

Culture of autologous bone marrow in diffusion chambers: effect of host irradiation

Autologous bone marrow (BM) cells were cultured in diffusion chambers (DC) implanted into whole-body irradiated, non-irradiated, or sham- irradiated goats. Proliferation was apparent in DC implanted in both irradiated and nonirradiated goats. However, cells in DC cultured in irradiated hosts increased in number beginning earlier, proceeded at a faster rate, and reached higher numbers than in DC in nonirradiated hosts. Growth enhancement could not have occurred as a result of radiation-induced immunosuppression in autologous hosts. The nonirradiated "target cells" in the DC therefore constituted an indicator system for stimulatory or inhibitory substances in the host. The simultaneous increase in the number of granulocytes in peripheral blood and in DC of irradiated hosts was paralleled by an initial rise in serum colony-stimulating factor (CSF). A second, prolonged period of severe granulocytopenia following irradiation of the host correlated with high levels of serum CSF. Increased numbers of megakaryocytes were seen in DC as thrombocytopenia developed in the irradiated host. DC erythropoiesis disappeared rapidly in nonirradiated goats; however, in DC of irradiated goats, the number of erythrocytic precursors increased exponentially during ablation of host erythroid marrow. Anemia did not develop in the host during the culture period. Proliferation of mononuclear cells in DC was markedly stimulated by irradiation of the host. Proliferation of macrophages appeared independent of host treatment. These observations provide strong evidence for diffusion of specific and/or nonspecific humoral hematopoietic stimulators from the host into the DC. This stimulation appears to be elicited and/or intensified by irradiation of the host.     

Intraductal papillary-mucinous tumors of the pancreas: Clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18)