Minimal invasive pocket technique for magnet bone implant hearing aid without fixation

European Archives of Oto-Rhino-Laryngology - The BAHA (bone-anchored hearing aid) Attract is a magnetic transcutaneous bone conduction device anchored into the temporal bone. The standard surgical...     

Biodistribution study of 99mTc-labeled LDL in B16-melanoma-bearing mice. Visualization of a preferential uptake by the tumor

Since there is strong evidence of a preferential LDL accumulation in tumor cells, LDL might be of interest for tumor imaging. We have tested the ability of ^99mTc-LDL in tumor imaging with B16-melanoma-bearing mice as a model for further applications in human studies. The LDL fixation rate was higher with 99^mTc-labeled LDL than with ¹²⁵I labeled LDL. Since technetium-99m remains trapped in the cells, ^99mTc-LDL is a well-adapted radioligand because of information given by this radiotracer on the receptor metabolism. We observed that, at early growth stages, the tumor took up the LDL at a maximal rate, suggesting differences in cholesterol metabolism as a function of tumor growth. Accumulation of label in the tumor area was perfectly observable in tumor-bearing mice on scintigraphic images. Computerized quantification of the regions of interest (as well as biodistribution studies including killing of the animals) showed a 1.81 -fold increase in uptake by the tumor as compared to the liver and a 28-fold increase as compared with corresponding normal tissue (muscle of the left leg) at day 8 of tumor growth. These data give strong support to the value of this non-invasive method in visualizing and quantifying the tissue LDL uptake in vivo, including the precise information provided by nuclear scintigraphy on the distribution of the radiolabeled LDL in the different tissues. ^99mTc-LDL could be an efficient tool for further diagnostic or therapeutic exploration in cancer patients.     

Thymidylate synthase activity,folates, and glutathione system in head and neck carcinoma and adjacent tissues

Background. Head and neck squamous cell carcinomas (HNSCC) present variable aggressiveness and chemosensitivity. Because the glutathione (GSH) system and thymidylate synthase (TS) are involved in the resistance to the main drugs used in HNSCC (cisplatin and 5-FU), we studied these systems in tumors and normal mucosae. Methods. Tumor samples and normal adjacent mucosae were collected from 37 untreated HNSCC patients. GSH and glutathione S-transferase (GST) activity were assayed by spectrophotometry, whereas TS activity and folates were determined by radioassays. Results. Mean GSH levels were higher in tumors (15.2 ± 8.2 nmol/mg protein) than in mucosae (8.3 ± 4.1 nmol/mg protein) (p = 0.005, paired t test). GST activity was also higher in tumors (394 ± 194 nmol/min/mg protein) than in mucosae (261 ± 132 nmol/min/mg protein) (p = 0.0003). TS activity was markedly higher in tumors (9.2 ± 21.5 pmol/min/mg protein) compared to that of mucosae (0.9 ± 1.2 pmol/min/mg protein) (p = 0.0001). Folate levels in tumors and mucosae were similar (1.2 ± 1.1 and 0.8 ± 0.9 pmol/mg protein, respectively; p = 0.1, NS). In relation to clinical stage and tumor size, a statistical difference was found in GSH and GST values between tumors and mucosae for stage IV and T3/T4. The increase in tumor TS compared to that of mucosae was significant for all clinical stages, tumor sizes, and nodal involvement. Conclusions. These data enhance our understanding of the enzymatic systems involved in cisplatin and 5-fluorouracil (5-FU) resistance in HNSCC and normal mucosae and may help to elucidate tumor behavior and interpatient differences in drug sensitivity. © 1994 John Wiley & Sons, Inc.     

Polymères thiocarboxyliques, 1. Synthèse et étude de la polymérisation radicalaire de monomères dithiocarboxyliques

The syntheses and free-radical polymerizations of methyl and carboxymethyl 4-vinyldithiobenzoates are described as well as various copolymers. Copolymerisation parameters were determined for the copolymerizations of the methyl dithioester with styrene and with methyl methacrylate.     

Pigtail catheter for the treatment of ascites associated with ovarian hyperstimulation syndrome

BACKGROUND: Severe ovarian hyperstimulation syndrome (OHSS) is potentially dangerous. The study aim was to evaluate the efficacy and safety of percutaneous pigtail catheter drainage for the management of ascites complicating severe OHSS. METHODS: This was a prospective trial conducted at a private IVF centre and a tertiary teaching medical centre. A total of 26 patients with severe OHSS was recruited. Patients were divided into two groups. Patients in group 1 (n = 13) were hospitalized, while patients in group 2 (n = 13) were managed on an outpatient basis. A pigtail catheter was inserted under transabdominal ultrasound guidance and kept in place until drainage ceased. The main outcome measures were resolution of OHSS as determined by symptomatology and laboratory values, time to removal of catheter, patient tolerance of the procedure and complication rate. RESULTS: The catheter was successfully placed in all patients following one attempt and was kept in place for a mean +/- SD of 12.9 +/- 4.3 days (range 7-24). Average amount of fluid drained was 11.2 +/- 4.3 l (range: 3.35-18.5). An improvement of symptoms and signs was noted 24-48 h after catheter placement in all patients in both groups. Procedure was well tolerated and no complications reported. CONCLUSIONS: Percutaneous placement of a pigtail catheter is a safe and effective treatment modality for severe OHSS. It may represent an attractive alternative to multiple vaginal or abdominal paracentesis.     

Unusual karyotypic evolution in subacute myelomonocytic leukemia in two monozygotic twins

A subacute myelomonocytic leukemia was diagnosed in 28-month-old cotwins. At this age, their spontaneously dividing cells had a normal karyotype. A few months later, after treatment with 6-mercaptopurine, the following karyotypes were observed: 50,XX, +X, +13, +19, +21 in one and 51,XX, +X, +X, +10, +19, +21 in the other. After bone marrow transplantation, both relapsed although they had received high doses of chemo- and radiotherapy. One developed a clone 46,XX,del(20q), which acquired other clonal rearrangements. The other child developed two different abnormal clones, both with unbalanced rearrangement of chromosome 13. Some of these clones may correspond to immature erythroblasts. The gain of chromosomes, especially for #13, which occurred independently in the cotwins by various mechanisms and at different periods during the disease, is very striking. It may indicate the existence of a strong selective advantage for trisomic 13 cells and may be related to the genetic constitution of the patients.