Translumbar placement of inferior vena caval catheters: a solution for challenging hemodialysis access

Access to the central venous circulation for hemodialysis has traditionally been achieved via the subclavian or jugular venous routes. With ongoing improvements in medical management, many hemodialysis recipients develop exhaustion of these routes and require alternative means of central venous access. Inferior vena caval (IVC) catheters have been placed with a percutaneous translumbar approach to allow central venous access for chemotherapy, harvesting of stem cells, and total parenteral nutrition. Translumbar placement of IVC catheters has become accepted by some as a useful and reliable alternative in patients who require long-term hemodialysis but have exhausted traditional access sites. IVC catheters have been placed in patients with IVC filters, and IVC filters have been placed in patients with IVC catheters. Complications include those associated with central venous catheters, for example, sepsis, fibrin sheaths, and thrombosis. A complication specific to placement of IVC hemodialysis catheters is migration of the catheter into the subcutaneous soft tissues, retroperitoneum, or iliac veins. Translumbar placement of IVC catheters is performed only in patients considered to have few or no other medical options and is not intended as a primary means of central venous access.     

Tea plant root extract (TRE) as an antineoplastic agent

The antitumour effect of tea plant root extract (TRE) has been evaluated against Ehrlich ascites carcinoma (EAC) in Balb-C mice. Significant increases of survival times of the TRE-treated, tumour-bearing mice have been confirmed repeatedly with respect to the control group. TRE inhibited the tumour cell growth and reversed the changes of haematological parameters consequent to tumour inoculation.     

Genomic characterization of the coding region of the human type II 5''-deiodinase gene

The conserved residue Asp477 in yeast transketolase is located in the substrate channel of the enzyme and forms a hydrogen bond with the C2-hydroxyl group of the acceptor substrate. The significance of this interaction for the recognition of the preferred acceptor substrates, D-alpha-hydroxyaldehydes was investigated by site-directed mutagenesis. In the wild-type enzyme the kcat/KM values are by three to four orders of magnitude lower for 2-deoxyaldoses or substrates with L-configuration at the C2-atom. In the Asp477 Ala mutant, the kcat/KM values for D-alpha-hydroxyaldehydes are decreased by a thousandfold, while the kcat/KM values for substrates with L-configuration or 2-deoxyaldoses are similar to wild-type enzyme. These results indicate that Asp477 is involved in determining the enantioselectivity of transketolase.     

Metabolism of bromodichloroacetate in B6C3F1 mice

Trichloroacetate (TCA), dichloroacetate (DCA), and bromodichloroacetate (BDCA) are byproducts of the chlorination of drinking water. TCA acts primarily as a peroxisome proliferator, but DCA produces tumors at doses less than required for peroxisome proliferation. BDCA does not induce peroxisome proliferation even at high doses. This study attempts to determine whether differences in the metabolism of the trihaloacetates (THAs) may contribute to their differing toxicological properties. Studies were performed in male B6C3F1 mice given [14C1,2]TCA, [14C1]BDCA, and [14C1,2]DCA by gavage. The replacement of a Cl by a Br greatly enhances THA metabolism. Much less radiolabel from BDCA is retained in the carcass after 24 hr than from TCA. Radiolabel from BDCA is largely found in the urine, with oxalate being the major metabolite. TCA is largely eliminated unchanged in the urine. There are dose-related changes in the rate of CO2 production from BDCA. The initial rate of CO2 production is reduced from 4.1 +/- 0.3 hr-1 at 5 and 20 mg/kg to 2.7 +/- 0.6 hr-1 at 100 mg/kg, but the net conversion to CO2 in 24 hr is greater at the highest dose. As would be predicted, substitution Br for Cl on TCA greatly increased its metabolism.     

Periodontal surgery of vertical bony defects with or without synthetic bioabsorbable barriers. 12-month results

The aim of the present study was to clinically and radiographically compare guided tissue regeneration (GTR) therapy with bioabsorbable polyglactin 910 barriers and conventional periodontal surgery in intrabony defects. In 26 patients with advanced periodontitis, 29 teeth exhibiting interproximal intrabony defects were treated; 15 by conventional periodontal surgery (control) and 14 by GTR (test). Before and 12 months after surgery, clinical parameters were assessed and standardized radiographs were taken. On the radiographs the distances from the cemento-enamel junction (CEJ) to the alveolar crest (AC), and the CEJ to the most apical extension of the bony defect (BD) were measured using a computer-assisted analyzing device (LMSRT). Twelve months after surgery, 24 patients with 27 lesions were available for examination. For both methods statistically significant (P < 0.001) probing depth (PD) reduction (mean +/- standard deviation) of -4.49 +/- 1.94 mm (n = 13, test) and -3.22 +/- 1.48 mm (n = 14, control), as well as clinical attachment gain (CAL-V) of 3.41 +/- 1.59 mm (test) and 2.07 +/- 1.10 mm (control), was observed. Radiographic changes of the distance CEJ to AC of -0.95 +/- 1.72 mm (n = 9, test), and -0.98 +/- 1.53 mm (n = 11, control) were not significant. A significant bony fill (distance CEJ-BD) of 1.05 +/- 1.22 mm was observed for the test group (P < 0.01); the 0.68 +/- 2.04 mm bony gain for the control group was not statistically significant. The PD reduction (P < 0.05) and attachment gain (P < 0.01) in the test group was statistically significantly more favorable than in the control group. Twelve months after surgery, statistically more favorable PD reduction and attachment gain was observed using polyglactin 910 barriers than compared to conventional flap surgery. Hence, the use of bioabsorbable barriers for therapy of intrabony defects may be recommended.     

Synthesis of amidrazones using an engineered papain nitrile hydratase

Diadenosine polyphosphates present at the cytosol can be transported to secretory granules allowing their exocytotic release. Extracellularly, they can act through specific metabotropic or ionotropic receptors, or as analogues of P2X and P2Y nucleotide receptors. The specific ionotropic receptor P4 is present in synaptic terminals, and modulated by protein kinases (PK) A and C and protein phosphatases. Activation of PKA or PKC, directly or through membrane receptors, results in a decrease of affinity or in reduction of the Ca2+ transient respectively. Adenosine and ATP, both products of the extracellular destruction of diadenosine polyphosphates, acting through A1 or P2Y receptors respectively, are important physiological modulators at the P4 receptor.     

The contribution of classical (beta1/2-) and atypical beta-adrenoceptors to the stimulation of human white adipocyte lipolysis and right atrial appendage contraction by novel beta3-adrenoceptor agonists of differing selectivities

The role of beta3- and other putative atypical beta-adrenoceptors in human white adipocytes and right atrial appendage has been investigated using CGP 12177 and novel phenylethanolamine and aryloxypropanolamine beta3-adrenoceptor (beta3AR) agonists with varying intrinsic activities and selectivities for human cloned betaAR subtypes. The ability to demonstrate beta1/2AR antagonist-insensitive (beta3 or other atypical betaAR-mediated) responses to CGP 12177 was critically dependent on the albumin batch used to prepare and incubate the adipocytes. Four aryloxypropanolamine selective beta3AR agonists (SB-226552, SB-229432, SB-236923, SB-246982) consistently elicited beta1/2AR antagonist-insensitive lipolysis. However, a phenylethanolamine (SB-220646) that was a selective full beta3AR agonist elicited full lipolytic and inotropic responses that were sensitive to beta1/2AR antagonism, despite it having very low efficacies at cloned beta1- and beta2ARs. A component of the response to another phenylethanolamine selective beta3AR agonist (SB-215691) was insensitive to beta1/2AR antagonism in some experiments. Because no [corrected] novel aryloxypropanolamine had a beta1/2AR antagonist-insensitive inotropic effect, these results establish more firmly that beta3ARs mediate lipolysis in human white adipocytes, and suggest that putative 'beta4ARs' mediate inotropic responses to CGP 12177. The results also illustrate the difficulty of predicting from studies on cloned betaARs which betaARs will mediate responses to agonists in tissues that have a high number of beta1- and beta2ARs or a low number of beta3ARs.