Kinetic studies of some substituted hexarhodium carbonyl clusters.

Reactions of the halides X- (X- = chloride, bromide or iodide) with the substituted cluster Rh6(CO)15(PPh3) in oxygen-free chloroform lead to [Rh5(CO)14(PPh3)]-, Rh(CO)2(PPh3)2X and [Rh(CO)2X2]- in the molar ratios 2:1: approximately 13. Oxidation by the solvent is assumed to lead to most of the Rh(I) product, and the stoichiometry for reactions with I- can be defined as 4Rh6(CO)15(PPh3) + 27I- + 12CHCl3 --> 2[Rh5(CO)14(PPh3)]- + Rh(CO)2(PPh3)2I + 13[Rh(CO)2I2]- + 6C2H2Cl4 + 4CO + 12Cl-. This can be rationalized quite simply with the aid of a few generally justifiable assumptions.

A degradation study of PLLA containing lauric acid.

Addition of lauric acid to poly (L-lactide) (PLLA) has resulted in a new family of enhanced degradation biomaterials. Presented is PLLA4.5 (PLLA containing 4.

Degradation of poly-L-lactide. Part 2: increased temperature accelerated degradation.

Poly-L-lactide (PLLA) is one of the most significant members of a group of polymers regarded as bioresorbable. The degradation of PLLA proceeds through hydrolysis of the ester linkages in the polymer's backbone; however, the time for the complete resorption of orthopaedic devices manufactured from PLLA is known to be in excess of five years in a normal physiological environment. To evaluate the degradation of PLLA in an accelerated time period, PLLA pellets were processed by compression moulding into tensile test specimens, prior to being sterilized by ethylene oxide gas (EtO) and degraded in a phosphate-buffered solution (PBS) at both 50 degrees C and 70 degrees C.

Biostability of Thoralon left ventricular assist device blood pumping sacs after long-term clinical use.

The purpose of this paper is to investigate the biostability of Thoralon polyurethane blood pumping sacs that have been used for up to 14 months in the Thoratec ventricular assist device (VAD) in human subjects. Thoralon is a proprietary polyetherurethaneurea (PEUU) blended with siloxane based surface modifying additive (SMA). Samples of Thoralon blood sacs that were used in Thoratec LVAD pumps for 53, 171, 336, and 434 days were taken from three distinct regions identified as high flex, medium flex, and low flex for physicochemical analysis.

Reactions of 2-indolylphosphines with Ru3(CO)12: cluster capping with mu 3,eta 2-indolylphosphine as an anionic six-electron P,N-donor ligand.

Stepwise bidentate coordination of the novel indolylphosphine ligands HL (1, HL = P(C(6)H(5))(2)(C(9)H(8)N)(diphenyl-2-(3-methylindolyl)phosphine); 2, HL = P(C(6)H(5))(C(9)H(8)N)(2)(phenyldi-2-(3-methylindolyl)phosphine); and 3, HL = P(C(6)H(5))(C(17)H(12)N(2))(di(1H-3-indolyl)methane-(2,12)-phenylphosphine)) to the ruthenium cluster Ru(3)(CO)(12) is demonstrated. Reactions of 1-3 with Ru(3)(CO)(12) led to the formation of Ru(3)(CO)(11)(HL) (4-6), in which HL is mono-coordinated through the phosphorus atom. The X-ray structures of 4-6 show that the phosphorus atom is equatorially coordinated to the triruthenium core.

Computational fluid dynamics analysis of a maglev centrifugal left ventricular assist device.

The fluid dynamics of the Thoratec HeartMate III (Thoratec Corp., Pleasanton, CA, U.S.

Poly(ADP-ribosyl)ation regulates CTCF-dependent chromatin insulation.

Chromatin insulators demarcate expression domains by blocking the cis effects of enhancers or silencers in a position-dependent manner. We show that the chromatin insulator protein CTCF carries a post-translational modification: poly(ADP-ribosyl)ation. Chromatin immunoprecipitation analysis showed that a poly(ADP-ribosyl)ation mark, which exclusively segregates with the maternal allele of the insulator domain in the H19 imprinting control region, requires the bases that are essential for interaction with CTCF.

Creep behavior of bone cement: a method for time extrapolation using time-temperature equivalence.

The clinical lifetime of poly(methyl methacrylate) (PMMA) bone cement is considerably longer than the time over which it is convenient to perform creep testing. Consequently, it is desirable to be able to predict the long term creep behavior of bone cement from the results of short term testing. A simple method is described for prediction of long term creep using the principle of time-temperature equivalence in polymers.

Cements from nanocrystalline hydroxyapatite.

Calcium phosphate cements are used as bone substitute materials because they may be moulded to fill a void or defect in bone and are osteoconductive. Although apatite cements are stronger than brushite cements, they are potentially less resorbable in vivo. Brushite cements are three-component systems whereby phosphate ions and water react with a soluble calcium phosphate to form brushite (CaHPO4 x 2H2O).

The toxicology of perfluorooctanoate.

PFOA is a peroxisome proliferator (PPAR agonist) and exerts morphological and biochemical effects characteristic of PPAR agonists. These effects include increased beta-oxidation of fatty acids, increases in several cytochrome P-450 (CYP450)-mediated reactions, and inhibition of the secretion of very low-density lipoproteins and cholesterol from the liver. These effects on lipid metabolism and transport result in a reduction of cholesterol and triglycerides in serum and an accumulation of lipids in the liver.

Bell's palsy, childbirth and epidural analgesia.

We report a case of Bell's palsy following delivery in a parturient who had successful epidural analgesia. Most reported cases have occurred after spinal anaesthesia or inadvertent dural puncture complicating epidural analgesia. Review of the literature revealed few cases of Bell's palsy associated with uncomplicated epidural analgesia.

Oral dexamethasone attenuates Doxil-induced palmar-plantar erythrodysesthesias in patients with recurrent gynecologic malignancies.

Objective: The aim of this study is to evaluate the effect of oral dexamethasone in attenuating palmar-plantar erythrodysesthesias (PPE) in Doxil-treated patients for gynecologic malignancies.

Methods: An IRB-approved prospective case study was conducted in patients with recurrent gynecologic malignancies who were treated with Doxil (50 mg/m(2)) on a 28-day cycle. Patients experiencing grades II-IV PPE were delayed until resolution then retreated without dose reduction and with a tapering oral dexamethasone regimen (8 mg BID days -1 to 4; 4 mg BID day 5; 4 mg day 6).

(R)-(+)-2,2'-Bis(diphenylphosphinoyl)-1,1'-binaphthyl.

The title compound, BINAP oxide, C(44)H(32)O(2)P(2), (I), was synthesized by direct oxidation of (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) with tert-butyl hydroperoxide in toluene solution. The angle between the naphthyl planes of the binaphthyl group is 94.17 (3) degrees.

Processing, annealing and sterilisation of poly-L-lactide.

Poly-L-lactide (PLLA) is one of the most significant members of a group of polymers regarded as bioabsorbable. Degradation of PLLA proceeds through hydrolysis of the ester bonds in the polymer chains and is influenced significantly by the polymer's molecular weight and crystallinity. To evaluate the effects of processing and sterilisation on these properties, PLLA pellets were either compression moulded or extruded, subjected to annealing at 120 degrees C for 4h and sterilised by ethylene oxide (EtO) gas.

Trans-dichloro(dimethyl sulfide-kappa S)(pyridine-kappa N)platinum(II).

The structure of the title compound, [PtCl(2)(C(5)H(5)N)(C(2)H(6)S)], consists of discrete molecules in which the Pt-atom coordination is slightly distorted square planar. The Cl atoms are trans to each other, with a Cl-Pt-Cl angle of 176.60 (7) degrees.

Assessment of preoperative fluid depletion using bioimpedance analysis.

Background: Fluid depletion during the perioperative period is associated with poorer outcome. Non-invasive measurement of total body water by bioimpedance may enable preoperative fluid depletion and its influence on perioperative outcome to be assessed.

Methods: Weight and foot bioimpedance were recorded under standardized conditions in patients undergoing bowel preparation (n=43) or day surgery (n=44).

Thoratec ventricular assist devices in children with less than 1.3 m2 of body surface area.

This report summarizes the multicenter experience with the Thoratec paracorporeal pneumatic ventricular assist device (VAD) (Thoratec Corp., Pleasanton, CA) in small children. Between October 1988 and August 2001, 19 children (11 male, 8 female) with less than 1.

Management of low-risk gestational trophoblastic neoplasia in indigent women.

Objective: To identify the most effective dosing regimen for indigent patients with low-risk gestational trophoblastic neoplasia (GTN) at high risk of noncompliance.

Study Design: All women primarily treated for GTN at our public hospital between November 1990 and November 2001 were prospectively entered into a database. Patients were treated with either (1) methotrexate, 100 mg/m2, intravenous bolus, followed by a 12-hour infusion, 200 mg/m2 (regimen 1); (2) methotrexate, 0.

Genetic variation in populations of the morphologically and ecologically variable fern Stegnogramma pozoi subsp. mollissima (Thelypteridaceae) in Japan.

In Japanese Stegnogramma pozoi subsp. mollissima (Fisher ex Kunze) K. Iwats.

Intravenous artificial oxygen carriers.

Haemoglobin-based oxygen carriers and perfluorocarbons have been developed as artificial oxygen carriers which can be safely administered intravenously. Mixed results from clinical trials to date suggest that further work is required to clearly demonstrate clinical efficacy and safety for these exciting products.

Postmolar surveillance at a trophoblastic disease center that serves indigent women.

Objective: The purpose of this study was to determine compliance with postmolar pregnancy surveillance in our indigent population.

Study Design: Data for all women who were diagnosed with molar pregnancy from January 1996 through December 2000 were entered prospectively into a database. After remission, postmolar pregnancy surveillance was continued for 6 months.

Assessing the health risks following environmental exposure to hexachlorobutadiene.

Hexachloro-1,3-butadiene (HCBD) has been reported to be toxic to the rat kidney in a 2 year study at doses higher than 0.2 mg/kg/day. The toxicity is known to be a consequence of the metabolism of HCBD by glutathione conjugation and the renal beta-lyase pathway.

Responses in the respiratory tract of rats following exposure to sulphuric acid aerosols for 5 or 28 days.

Sulphuric acid mists have been classified by the International Agency for Research on Cancer as being carcinogenic to humans based on epidemiological findings of respiratory tract tumours. To determine if early changes in the respiratory tract following exposure to sulphuric acid (H(2)SO(4)) aerosols are consistent with the possible development of tumours after extended periods of exposure, groups of female rats were exposed to respirable aerosols of H(2)SO(4) at target concentrations of 0, 0.2, 1.

Alternative methods for the median lethal dose (LD(50)) test: the up-and-down procedure for acute oral toxicity.

The authors have developed an improved version of the up-and-down procedure (UDP) as one of the replacements for the traditional acute oral toxicity test formerly used by the Organisation for Economic Co-operation and Development member nations to characterize industrial chemicals, pesticides, and their mixtures. This method improves the performance of acute testing for applications that use the median lethal dose (classic LD50) test while achieving significant reductions in animal use. It uses sequential dosing, together with sophisticated computer-assisted computational methods during the execution and calculation phases of the test.

Current clinical status of pulsatile pediatric circulatory support.

Whereas circulatory support with pulsatile assist devices is an established therapy in adults today, it remains unusual and extremely challenging in children. Specifically designed smaller size pumps are, to date, only available in Europe. This review summarizes the experience with both adult size pumps in the U.