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Biomedical subjects

A Roche

Publications and source records attributed to A Roche.

At least 127 records · Page 7Linked to original sources
PubMed1989

Gianturco expandable metallic biliary stents: results of a European clinical trial.

Eleven patients with benign strictures (after choledochojejunostomy, n = 10; chronic pancreatitis, n = 1) and 16 with malignant biliary strictures (cancer of the pancreas, n = 7; cholangiocarcinoma, n = 5) were treated with a self-expanding metallic biliary stent. The patients with benign disease had failed treatment with surgical reconstruction and transhepatic balloon dilation. All patients had immediate relief of jaundice and cholangitis. In a follow-up period of 6-21 months, nine of the 11 patients with benign disease had no difficulties with infection, pruritus, or recurrent jaundice. In patients with malignant strictures, the stent produced relief of biliary obstruction unless recurrent tumor invaded the bile ducts. With careful patient selection, this stent appears to be useful in the management of biliary obstruction, particularly in benign disease.

Adult↗
PubMed1989

Effect of uncoupling treatments on FSH-induced hyperpolarization of immature rat Sertoli cells from Sertoli cell-enriched cultures.

Sertoli cell-enriched cultures isolated from immature rat testes by enzymic treatments were investigated by intracellular microelectrode recordings. The hyperpolarization of cells induced by FSH was independent of the age of the rats (7-37 days) and was unchanged by exposure to a hormone-free medium or to a glycine buffer of pH 3. It was reduced by treatments which decreased the electrical coupling between cells either by an increase of intracellular calcium [i.e. calcium ionophore (A 23187, 5 x 10(-6) M), general anaesthetic (heptanol, 3.5 mM) and uncoupler of oxidative phosphorylations (carbonylcyanide m-chlorophenylhydrazone-CCmP, 10(-6) M)] or by a decrease of extracellular calcium [i.e. 0Ca + EGTA (1 mM) medium]. These effects were partly or totally reversed by a recovery period in a drug-free medium. Similar results were obtained by an exposure to trypsin (0.05%) followed by a second mechanical dispersion, but new cell hyperpolarization was induced by a new exposure to FSH. This electrophysiological study suggests an initial effect of FSH on the junctional complex between Sertoli cells, then the control by calcium of this complex.

Aging↗
PubMed1989

[Celiac neurolysis. Anterior approach and x-ray computed tomographic guidance: a simple and logical technic].

Two cases of celiac plexus neurolysis under CT guidance by an anterior approach are reported. This technique was performed on two patients who complained of epigastric pain due to a pancreatic carcinoma. Alcoholization was performed with 50 cc of a 50% solution of ethyl alcohol. The tip of the needle was located just above the origin of the coeliac axis in front of the aorta. In the two cases the block was successful, leading to suspension of morphine administration. Computed tomography scans after injection showed that the space of diffusion corresponds to the presumed location of the celiac plexus and confirms that the anterior approach is valid providing that a sufficient dose is injected. This technique, can be easily performed and deserves a more important place in the management of pancreatic pain.

Autonomic Nerve Block↗
PubMed1988

Electrophysiological studies of the action of gonadotropins on Leydig and Sertoli cells from rat testis.

Using intracellular microelectrode recordings, it was observed that FSH caused the hyperpolarization of cultured Sertoli cells from the testis of 17-day old rats; this hyperpolarization was related to the activation of a Na/K pump and an increase in Na/Ca influx and K efflux. The effect was irreversible and mediated by cAMP. Some other results suggested an initial effect of FSH on the junctional complex between the Sertoli cells and then its calcium dependence. Voltage-clamped membrane currents were investigated from whole-cell patch clamp recordings performed on single Leydig cells isolated from adult rat testis. Two outward currents were evoked by depolarizing voltage steps: a potassium current recorded in cells dialyzed with low-calcium media (10(-9)-10(-8) M) and a chloride current recorded in cells dialyzed with high-calcium media (10(-7)-10(-6) M). These responses to modifications of intracellular calcium were not affected by hCG. However, this hormone induced an early change of the K current to a Cl current when the cells were dialyzed by a low-buffered EGTA-calcium medium. These results suggest that hCG stimulation involved the blockade of a potassium current and the activation of a chloride current through an increase of intracellular calcium.

Animals↗
PubMed1988

Follicle-stimulating hormone induces hyperpolarization of immature rat Sertoli cells in monolayer culture.

1. The effect of FSH on the membrane potential of Sertoli cells has been investigated by intracellular microelectrode recording from monolayer cultures of cells, isolated from immature rat testes by enzymatic treatment. 2. In standard Earle's solution, the membrane potential of unstimulated cells in a 3-day-old monolayer was -21.6 +/- 0.2 mV (n = 300). The recorded potentials were unchanged on varying the culture period from 3 to 7 days or by removal of chloride or calcium from the media. However, they were decreased in a low-sodium or potassium-rich medium. 3. Ovine FSH caused hyperpolarization of the cell in a dose-dependent manner. Maximal values were obtained with concentrations ranging between 2.9 and 5.9 micrograms/ml (-37.0 +/- 0.2 mV; n = 310). Dibutyryl cyclic AMP (1 mM) produced a similar effect to FSH. Under similar conditions human chorionic gonadotrophin (hCG) had no effect on the membrane potential. 4. The FSH-induced hyperpolarization was unchanged by chloride or bicarbonate replacement. It was decreased by low-sodium media (9 mM) (-29.6 +/- 0.3 mV; n = 110), by removal of calcium (-32.4 +/- 0.6 mV; n = 128) and by an increase in the potassium concentration of the bathing medium. A tenfold increase in potassium concentration depolarized the cell by 29.5 mV against 16 mV for unstimulated cells. 5. FSH-induced hyperpolarization was decreased by application of ouabain (10(-4) M), quinidine (1.4 x 10(-4) M) and cobalt (10(-3) M) (respectively: -28.7 +/- 0.3 mV, n = 124; -26.6 +/- 0.3 mV, n = 52 and -24.8 +/- 0.3 mV, n = 68) but was unchanged by amiloride (10(-4) M) and TTX (3 x 10(-6) M). None of these drugs modified the membrane potential of unstimulated cells. 6. All these results suggest that FSH stimulation of Sertoli cells in monolayer culture involves the modification of their membrane permeabilities.

Animals↗
PubMed1988

[Imaging of nodular regenerative hyperplasia of the liver. Study of 9 cases].

Radiologic patterns of the liver in nodular regenerative hyperplasia are poorly known. The authors describe the features of the liver observed during ultrasonography, angiography, computed tomography and magnetic resonance imaging in 9 patients with nodular regenerative hyperplasia. Generally the liver appeared normal, occasionally with signs of portal hypertension. However, a pseudotumoral pattern was observed in 2 patients: they had well limited hypoechoic lesions on ultrasonography, and in one patient angiography showed hypervascularity.

Adult↗
PubMed1988

[Vascular malformations of the cecum: treatment by embolization. Apropos of 2 cases].

Two cases of arteriovenous malformations of the cecum treated by transcatheter embolization are presented. In both cases, treatment resulted in improvement of the clinical and biological signs. In general, there is a high risk of ischemic complications associated with this treatment. Embolization of arteriovenous malformations should be considered rarely and in the following cases: single lesion, high blood output, feasibility of superselective catheterization. The risk of colonic ischemia calls for preparation of the colon as if the patient were undergoing colonic surgery, as well as thorough clinical follow-up (for at least 10 days).

Adolescent↗
PubMed1988

Quality management: program design. An interdisciplinary approach.

Concepts of quality management related to program design and implementation are relatively new to the health care field. The process used to satisfy the requirements of program evaluation, business planning, and clinical care quality assurance within the framework of quality management is discussed. Using an interdisciplinary approach, the authors trace the development of a specific rehabilitation program. Such programs can allow the health care provider to be more fruitfully involved in a health care service design beneficial to the patients served.

Hospital Bed Capacity, 300 to 499↗
PubMed1987

Ultrastructural visualization of the internalization of low density lipoprotein by human placental cells.

Low density lipoproteins (LDL) were conjugated to colloidal gold to visualize the route for internalization of LDL in the cultured cells of human term placenta. Cells were obtained from placental villi (caesarian section) by a standard trypsin-DNase dispersion method followed in some cases by a Percoll gradient centrifugation step. Employing electron microscopy it was observed that after 3 days of culture, cells obtained by trypsin-DNase dispersion were a mixture of macrophages, mononucleated cells and large multinucleated cells. When the cells were incubated for 3 days after the Percoll purification, essentially multinucleated cells identical to the syncytiotrophoblast were present. The number of LDL receptor was increased by preincubation in medium with lipoprotein depleted serum. In binding experiments cells incubated at 4 degrees C for 2 h with medium containing gold LDL conjugates showed gold LDL attached to the plasma membrane without characteristic localization. After incubation with gold LDL at 37 degrees C for various times, the three cellular types showed ligand internalization. Gold LDL endocytosis involved first coated pits but also uncoated plasmalemmal invaginations. Then gold LDL was further observed in coated and non coated vesicles, smooth walled endosomes, multivesicular bodies and tubular vesicles. Lastly free gold particles were observed in lysosome like dense bodies. These results prove the internalization of gold LDL conjugates by human cultured placental cells, particularly by syncytiotrophoblast like multinucleated cells. This accumulation of LDL (the major cholesterol carrying protein in humans) is recognised to be responsible for the exogenous cholesterol supply indispensable to the progesterone biosynthesis and cellular growth of the placenta.

Cells, Cultured↗
PubMed1987

[Pseudo-aneurysm in acute necrotico-hemorrhagic pancreatitis: direct transcutaneous embolization. Apropos of 2 cases].

Massive hemorrhage associated with pancreatitis is rare but frequently lethal complication. We report two patients with gastrointestinal hemorrhage related to pseudo-aneurysms, the control of these lesions was not possible without risk by vascular selective embolization. The technique we reported for clotting aneurysms by direct injection (Ethibloc) stopped hemorrhage temporary in one case and permanently in the other.

Acute Disease↗
PubMed1987

[Mediastinal pseudotumors in cirrhosis. Diagnostic value of nuclear magnetic resonance in 3 cases].

We report 3 cases of mediastinal pseudotumours in cirrhotic patients. In the 3 cases, plain chest X-ray showed regular homogeneous radiolucency superposed on cardiac shadow. Computerized tomography bolus injection, performed in 2 cases, was poorly contributive in one case. On the other hand, magnetic resonance imaging ensured the diagnosis in all 3 patients showing significant dilatation of the azygos vein and prominent esophageal varices connected with spontaneous abdominal portacaval shunts. These vascular mediastinal structures were well documented by frontal and sagittal spin echoes. Knowledge of such neovascular mediastinal pseudotumours may prevent the use of invasive investigations such as direct puncture or thoracotomy.

Diagnosis, Differential↗