Homograft valves.
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Biomedical subjects
Publications and source records attributed to A Roche.
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We have studied families segregating for the fragile X syndrome for the presence of amplification of the CGG repeat sequence adjacent to the HpaII Tiny Fragment (HTF) island in the FMR-1 gene. We demonstrate that 138/143 fragile X positive, mentally retarded males show a characteristic smear of fragments corresponding to somatic variation in the amplification of the CGG sequence. In 7/8 normal transmitting males (NTM's), we show that there is a small amplification of sequence but no evidence for somatic variation. Defined mutated fragments in the size range found in NTM's are seen in daughters of NTM's. The daughters of these female carriers show either a defined fragment in the NTM size range, a defined larger fragment or a heterogeneous pattern of fragments. In the latter 2 cases the clinical phenotype of the females cannot easily be predicted, presumably because of variable X inactivation. In some families, the observed DNA genotype does not correlate with the phenotype; in others we demonstrate the occurrence of individuals with a mosaic DNA genotype. The implications of these data for diagnosis of the disease are discussed.
PURPOSE: To determine the efficacy of a cystoscopic approach, as definitive treatment of ureteral fistulae, after failure of antegrade ureteral stent insertion. METHODS: Of 43 ureter fistulae encountered over 4 years, 10 postoperative and/or postradiotherapy fistulae could not be stented via an antegrade approach alone. A cystoscopic approach was used, with the antegrade approach available as back-up, if necessary. RESULTS: In two patients the ureteral orifice could not be visualized cystoscopically, thus precluding the retrograde approach. In the eight remaining patients, the retrograde approach alone never allowed successful stenting. In six patients, combined antegrade and retrograde approaches permitted stent insertions. In three of those six patients, a complex catheterization procedure was necessary. In two patients the combined approach failed altogether. Therefore, 6 of 10 patients underwent a successful stenting procedure with the combined approach; all ultimately closed the fistula. CONCLUSION: Antegrade stent insertion remains the treatment of choice for ureteral leaks. If the antegrade approach fails, the retrograde approach alone is not likely to be successful. Instead, a combination of both approaches often does succeed.
PURPOSE: To determine the effects of percutaneous intratumoral chemotherapy with mitoxantrone (PIM) in the palliative treatment of malignant liver lesions. METHODS: We treated 15 progressive lesions in nine patients in whom either previous therapy failed or serious complications developed as a result. Seven lesions were metastatic and eight were due to foci of hepatocellular carcinoma. Under computed tomography (CT) guidance, we percutaneously injected 10-20 mg of mitoxantrone mixed with 0.5 ml of contrast medium into the tumor, performing one to three treatments at intervals of 1 month. RESULTS: There were no complications. The morphologic responses of the tumors after treatment were: minor response in one case, no change in 11 cases, progressive disease in three cases. Mitoxantrone induced tumor necrosis with no viable cancer tissue in eight of 11 biopsies. Recurrence was observed in nine of the treated lesions 2-9 months after treatment. New lesions were observed in five of nine patients 1-9 months after treatment. CONCLUSION: In patients with malignant liver lesions with no other therapeutic possibilities, minimally invasive intratumoral mitoxantrone injection was carried out safely with good tumor delivery of chemotherapy, and tumor necrosis was demonstrated at biopsy. We feel this approach warrants further investigation.
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We used MRI volume sampling with coregistered and atrophy corrected FDG-PET scans to test three hypotheses: 1) hippocampal formation measures are superior to temporal neocortical measures in the discrimination of normal (NL) and mild cognitive impairment (MCI); 2) neocortical measures are most useful in the separation of Alzheimer disease (AD) from NL or MCI; 3) measures of PET glucose metabolism (MRglu) have greater diagnostic sensitivity than MRI volume. Three groups of age, education, and gender matched NL, MCI, and AD subjects were studied. The results supported the hypotheses: 1) entorhinal cortex MRglu and hippocampal volume were most accurate in classifying NL and MCI; 2) both imaging modalities identified the temporal neocortex as best separating MCI and AD, whereas widespread changes accurately classified NL and AD; 3) In most between group comparisons regional MRglu measures were diagnostically superior to volume measures. These cross-sectional data show that in MCI hippocampal formation changes exist without significant neocortical changes. Neocortical changes best characterize AD. In both MCI and AD, metabolism reductions exceed volume losses.
PURPOSE: The reactivity and patency of balloon-expandable Strecker stents were determined in the superior vena cava (SVC) and inferior vena cava (IVC) of rabbits. MATERIALS AND METHODS: One stent was placed in each of 24 rabbits; 15 were placed in the SVC and nine in the IVC. The duration of stent placement varied between 3 days and 15 months. After the animals were killed, the segments in which the stent was placed were sectioned and analyzed under light microscopy for quantification of neointimal hyperplasia with metal struts in situ. RESULTS: Twenty-three stents remained patent throughout. Two SVC stents thrombosed at 1 week; one of these recanalized spontaneously after 4 weeks. Self-limiting neointimal hyperplasia reached a maximum thickness at 1 month and receded over 3-6 months. In five rabbits with long-term SVC stents, there was a radial shift of the stent to the perivascular layer of fat. Despite this shift, these stents remain patent. CONCLUSION: Strecker stents are well adapted to the venous system in terms of both patency and histocompatibility.
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PURPOSE: A strong embolic effect of iodized oil/drug mixtures injected in the hepatic artery appeared to be an efficient way of prolonging the contact time between drugs and tumor tissue. Therefore, the authors evaluated arterial and portal embolic effects after hepatic intra-arterial injection of iodized oils and various emulsions of iodized oil. MATERIALS AND METHODS: Twenty-five pigs were monitored for the Doppler resistance index (DRI) in the hepatic artery and wedge hepatic vein pressure (WHVP) during 1 hour after injection of pure iodized oil, ultra-fluid or fluid, and four different emulsions of iodized oil ultra-fluid, into the hepatic artery. RESULTS: Mean area under the curve (AUC) values of DRI increases varied from 20.3 to 24.2 after injection of pure iodized oils or water-in-oil emulsions, and were 13.2 for large-droplet oil-in-water emulsion and 8.2 for small-droplet oil-in-water emulsion. Mean AUC values of WHVP increases varied from 151.6 to 195.6 after injection of pure iodized oils or water-in-oil emulsions, and were 105.5 for large-droplet oil-in-water emulsion and 8.5 for small-droplet oil-in-water emulsion. There was a significant difference in DRI and WHVP modifications between small-droplet oil-in-water emulsions and all other products (P = .001), between the two oil-in-water emulsions and the two water-in-oil emulsions (P = .004), and between the two oil-in-water emulsions and pure iodized oils (P = .002). CONCLUSION: After hepatic intra-arterial injection, water-in-oil emulsions and pure iodized oils provided a stronger embolic effect than oil-in-water emulsion, both in the hepatic artery and in the portal vein.
We retrospectively evaluated 10 patients with pathologically proven fibrolamellar hepatocellular carcinoma (FLHCC) to assess the utility of CT (n = 9), ultrasound (n = 10), angiography (n = 9), and MR (n = 3). The tumors were solitary in 6 of 10 patients, well delineated in 7 of 10, and hypervascular in 8 of 10. With use of multimodality imaging techniques, a central scar was demonstrated in 3 of 10 patients, calcifications in 4 of 10, dilated intrahepatic ducts in 2 of 10, thrombosis of a segmental portal branch in 2 of 10, and lymph node involvement in 3 of 10. Computed tomography was the most accurate technique for diagnosis and staging. Magnetic resonance imaging helped establish the correct diagnosis in one patient. This report emphasizes the wide variability of imaging features of FLHCC and the predominant role of CT for suggesting the diagnosis.
The MR imaging features in five patients with hepatic epithelioid hemangioendothelioma (EHE) were correlated with CT and pathologic findings. Two hemangioendotheliomas appeared as multiple nodular lesions with a predominantly peripheral location in the liver. In three more extensive cases, the tumors formed confluent peripheral lesions with macroscopic invasion of portal or hepatic veins (n = 3), signs of portal hypertension (n = 3), and nodular hypertrophy of uninvolved liver (n = 2). These findings, suggestive of EHE, were well demonstrated by MR imaging and CT. The internal architecture of the tumors was clearly depicted on T2-weighted MR images. Viable tumor peripheries appeared moderately hyperintense relative to liver. The center of the tumors consisted of one or several concentric zones. Hyperintense central zones were composed of loose, edematous connective tissue. Hypointense zones contained mainly coagulation necrosis, calcifications, and scattered hemorrhages. Except for the presence of calcifications, the internal architecture of EHE was better defined by MR imaging than by CT.
A prospective study was performed to compare, with a lesion-by-lesion analysis, the sensitivities of high field strength MRI and CT during arterial portography (CTAP) in detecting hepatic metastases from colorectal cancer. Twenty-one patients with liver metastases from colorectal cancer were prospectively investigated by high field strength MRI (1.5 or 2 T) and CTAP. High field strength MRI was performed with pre and post gadopentetate dimeglumine enhanced T1-weighted SE sequences and T2-weighted SE sequences. All patients underwent partial hepatectomy and 37 metastases were surgically and pathologically proved. The metastasis detection rate (sensitivity) was 94% (35 of 37) for CTAP and 78% (29 of 37) for high field strength MRI. The 16% (95% confidence interval: 1-31%) difference in sensitivity between CTAP and high field strength MRI was statistically significant (p < 0.05, McNemar test). The use of gadopentetate dimeglumine did not improve the sensitivity of T1-weighted SE sequences. Since our study demonstrated significant difference in sensitivities between high field strength MRI and CTAP in our group of patients, we can conclude that high field strength MRI cannot replace CTAP in the preoperative evaluation of patients with liver metastases from colorectal cancer. Computed tomography during arterial portography must be considered as the preoperative gold standard.
Chemoembolization is the injection of active-principle-bearing microparticles via selective catheterization. The authors discuss the advantages and the possibilities of this method in relation to selective catheterization and to the various time periods required for microparticle biodegradation and the kinetics of drug release. Particular attention is paid to intra-arterial chemoperfusion, chemoembolization and chemoinfusion with microparticles.
Nowadays, TACE is routinely performed in a subgroup of patients with hepatocellular carcinoma who are not eligible for surgical resection or percutaneous tumor ablation and who do not preset contraindications to locoregional treatment. When comparing randomized to nonrandomized studies, TACE efficacy upon survival is still controversial in this subgroup despite a 40-50% response rate. Nevertheless, in a pragmatic approach, and as long as other therapies still fail in this subgroup, TACE can be recommended in Okuda I or II patients, the sessions being prolonged after the second one only for the responders who do not present severe side effects.
BACKGROUND/AIMS: The aims of this study were to assess response rates, evaluate side effects and determine prognostic factors for both response and toxicity in patients with liver metastasis from endocrine tumors treated with chemoembolization. METHODOLOGY: Data concerning 64 patients who underwent a total of 186 sessions of chemoembolization were retrospectively evaluated and correlated with response and toxicity after chemoembolization. RESULTS: Overall clinical, morphological and biological response rates were 93%, 74% and 52% respectively. Complete control of hormone-related symptoms was obtained in 59% of patients with a mean duration of response of 15 months. Transient major complications occurred after 5.9% of sessions and 3 patients died. In the univariate and multivariate analyses, a non-pancreatic primary and chemoembolization as first-line non-surgical treatment were prognostic factors for clinical response, and <30% of liver involvement for morphological response. A significant increase in morbidity was noted in patients with more than 70% of liver involvement. CONCLUSIONS: Hormone-related symptoms were controlled in the majority of patients with a non-pancreatic primary and in those treated with chemoembolization as first-line therapy. Morphological response and toxicity were respectively correlated with liver involvement of less than 30% and greater than 70%.
The main aspects of hepatic chemoembolization are first described: principles, drugs and their vectors, various techniques and contra-indications. In the literature as in our own experience, most encouraging results are reported in metastases from endocrine tumors and hepatocellular carcinoma. Favourable results in the latter disease have been particularly emphasized by Japanese authors whose data are reported, as well as results in a personal series and in three controlled studies. Chemoembolization is now able to induce partial or complete responses. Nevertheless, unambiguous selection of responding patients cannot be stated yet, especially for hepatocellular carcinoma where an underlying chronic liver disease probably plays an important role in prognosis. Consequently, chemoembolization of malignant hepatic tumors must still be considered as a technique under evaluation.