Thin films of calcium phosphate and titanium dioxide by a sol-gel route: a new method for coating medical implants

Titanium is a commonly used biomaterial for dental and orthopaedic applications. To increase its ability to bond with bone, some attempts were made to coat its surface with calcium phosphate (CaP). This paper describes a new type of coating. Instead of a pure CaP layer, a mixing of titanium dioxide (TiO₂) and CaP is fabricated and deposited as a coating. These layers are deposited by a sol-gel route on pure titanium substrates using various pre-treatments. The method consists of mixing a solution of tetrabutyl ortho-titanate or a sol of titanium dioxide with a solution of calcium nitrate and phosphorous esters. This composite is deposited on to commercially pure titanium plates, mechanically polished or blasted with pure crystalline aluminum oxide, using the spin-coating technique. These coatings are then fired at 650 or 850°C for various times. The samples are characterized by X-ray diffraction for their crystallinity, X-ray photoelectron spectroscopy for their surface chemical composition and scanning electron microscopy for their topography. Samples treated at 850°C present a well-pronounced crystallinity, and a high chemical purity at the surface. The topography is strongly related to the viscosity of the precursor and the substrate pre-treatment. Possibilities to structure the outermost layer are presented. © 1999 Kluwer Academic Publishers     

Low plasma vitamin A concentrations in familial combined hyperlipidemia

As many as 20% of the survivors of acute myocardial infarction present with the heritable form of hyperlipidemia, termed familial combined hyperlipidemia (FCHL). Some of the genes reported to be involved in this disorder, such as those for lipoprotein lipase (LPL) and apolipoprotein (apo) C-III, are controlled by a peroxisome proliferator-activated receptor (PPAR)/retinoic acid receptor X (RXR) regulatory system, which is retinoic acid dependent. If, as we hypothesized, the availability of retinoic acid or its precursor retinol (vitamin A) could be altered in FCHL, this could help explain some aspects of the phenotypic expression of the disease. We therefore measured plasma retinol concentrations in 30 FCHL subjects and 56 controls. Plasma retinol concentrations in FCHL subjects were significantly lower than that of control subjects (1.96 +/- 0.83 mumol/L vs 2.91 +/- 1.23 mumol/L, respectively; P < 0.0001). This novel finding of significantly decreased concentrations of plasma retinol in FCHL relative to control subjects gives support to the hypothesis that vitamin A might be involved in the expression of this disorder.     

Oxidized lipoproteins including HDL and their lipid peroxidation products inhibit TNF-alpha secretion by THP-1 human macrophages

It has been established that oxidized LDL (ox-LDL) modifies cytokine secretion by macrophages, for example, by reducing tumor necrosis factor alpha (TNF-(alpha) m-RNA. However, little is known about the effects of oxidized high density lipoprotein (ox-HDL). This study reports the effects of ox-HDL subfractions 2 and 3 (ox-HDL2, ox-HDL3) compared with that of ox-LDL and some products of oxidation (hydroperoxides and aldehydes) on the secretion of TNF-alpha from THP-1 human monocytes derived macrophages in vitro. HDL2, HDL3 and LDL were oxidized with 10 microM Cu++ for 12 h and/or 24 h. Native and oxidized HDL and LDL were incubated for 24 h with macrophages with or without LPS (10 ng/ml) after which TNF-alpha secretion was measured in the culture medium. Lipid hydroperoxides and apolar aldehydes were also incubated with the cells for 2 h following which the medium was replaced and TNF-alpha secretion measured after a further 22 h of incubation. An inhibition of TNF-alpha by ox-HDL2 (p < .05), ox-HDL3 (p < .05) and ox-LDL (p < .05) from THP-1 macrophages was observed in the presence and absence of LPS. This inhibition remained the same after incubation with ox-HDL 12 h and 24 h. Hydroperoxides of linoleic acid did not modify TNF-alpha secretion by cells while five out of eight aldehydes analyzed (2,4-heptadienal, hexanal, 2-nonenal, 2-octenal, 2,4-decadienal) inhibited TNF-alpha secretion (p < .05). These findings demonstrate that ox-HDL, and some of its lipid peroxidation products, plays a role in the modulation of the inflammatory response by macrophages as previously observed for ox-LDL.     

Influence of regulated deficit irrigation strategies applied to olive trees (Arbequina cultivar) on oil yield and oil composition during the fruit ripening period

This study evaluated the effect of regulated deficit irrigation (RDI) strategies applied to olive trees (Arbequina cv) during the fruit ripening and harvest periods on oil yield and oil composition. Fatty acid composition, pigments, colour, polyphenol content and stability of oils were evaluated. The results indicate that regulated deficit irrigation induces fruit ripening; at harvest, oil yield increased when water supply was decreased, probably as a consequence of lower water content in the olive. Acidic composition was not affected by irrigation treatments. Irrigation affected pigment content and oil colour primarily during the early stages of olive ripening. RDI increased polyphenol concentration and stability of oils at all picking dates, especially during the first stages of the ripening period, probably owing to water stress. © 2000 Society of Chemical Industry     

Composition and organoleptic characteristics of oil from Arbequina olive (Olea europaea L) trees under deficit irrigation

This study evaluated the effects of different regulated deficit irrigation (RDI) strategies applied to olive (Arbequina cultivar) trees on the qualitative and quantitative parameters of the resulting oil during the maximum evaporative demand period for three consecutive crop seasons. Quality indices, fatty acid composition, pigments, colour, α‐tocopherol and phenolic contents, bitter index, oxidative stability and organoleptic properties of the oil were determined. Irrigation did not affect those parameters used as criteria for classifying olive oil in its commercial grades. Only polyphenol and o‐diphenol contents and, consequently, the bitter index and oxidative stability were affected by the RDI strategy, with increasing values as the water applied decreased. Regulated deficit irrigation resulted in important savings in irrigation requirements without detriment to oil quality. © 2002 Society of Chemical Industry     

Analytical characteristics of virgin olive oil from young trees (arbequina cultivar) growing under linear irrigation strategies

The effect of a linear (vs. effective crop coefficient, K _c), irrigation strategy applied to young olive trees (Arbequina cv.) on the qualitative and quantitative parameters of virgin olive oil quality was studied. Although linear irrigation strategy did not affect the quality indexes used to classify olive oil by commercial grades, it did influence other important parameters such as total phenol content, bitter index oxidative stability, and the sensorial appraisal. All of these of olive oil qualities were negatively associated with the amount of applied irrigation water. Pigment content of oils determined by carotenoid and chlorophylls also was negatively associated with the amount of water supplied. No consistent relation was found for α-tocopherol and fatty acid content of olive oil in relation to these treatments.     

Experiences with the Soviet suture stapler SPTU in colon and and rectum surgery. Controlled study of 94 patients

In a controlled study the practicability, tightness of the anastomosis and complications in the p.o. period were analyzed in a total 94 colon and rectum anastomoses by making use of the SPTU-model. 28% of the patients operated in this way were more than 70 years old, the average age came up to 63.3 years. The incidence of anastomotic leakage after low anterior resection was 24% and 5.5% after high anterior resection. 17 per cent of the patients suffered from complications during the postoperative period and 2 patients (2.1 per cent) came to death. The results of 36 high and 58 low anterior resections justify the further use of the SPTU auto-suture apparatus.     

Stability of vinblastine sulphate in 0.9% sodium chloride in polypropylene syringes

The stability of vinblastine sulphate diluted in 0.9% sodium chloride solution for injection was studied. Vinblastine sulphate was reconstituted with 0.9% sodium chloride solution for injection to concentration of 1.0 mg/mL and stored in polypropylene syringes at 25 degrees C +/- 1 degree C protected from light. On different days the solutions were analysed and the vinblastine concentration was determined by high-performance liquid chromatography. An high-pressure liquid chromatographic method is described for the quantitative determination of vinblastine in the presence of its degradation products. The degradation of vinblastine was studied by examining the percentage changes from the theoretical concentrations for each solution. The results of these studies indicate that vinblastine solutions in 0.9% sodium chloride solution for injection (1 mg/mL) in polypropylene syringes at 25 degrees C +/- 1 degree C protected from light are stable for up to one month.     

Inducible Genetic Code Expansion in Eukaryotes

Genetic code expansion (GCE) is a versatile tool to site-specifically incorporate a noncanonical amino acid (ncAA) into a protein, for example, to perform fluorescent labeling inside living cells. To this end, an orthogonal aminoacyl-tRNA-synthetase/tRNA (RS/tRNA) pair is used to insert the ncAA in response to an amber stop codon in the protein of interest. One of the drawbacks of this system is that, in order to achieve maximum efficiency, high levels of the orthogonal tRNA are required, and this could interfere with host cell functionality. To minimize the adverse effects on the host, we have developed an inducible GCE system that enables us to switch on tRNA or RS expression when needed. In particular, we tested different promotors in the context of the T-REx or Tet-On systems to control expression of the desired orthogonal tRNA and/or RS. We discuss our result with respect to the control of GCE components as well as efficiency. We found that only the T-REx system enables simultaneous control of tRNA and RS expression.     

Intestinal obstruction secondary to endometriosis of the colon

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity. Although in most cases it is a benign disorder, it may be aggressive producing local invasion and even metastasis. Endometrial implantation has been reported in many organs including the small and large intestine leading to acute or chronic symptomatology. The clinical picture of intestinal obstruction is due to stenosis produced by the adherences or fibrosis caused by endometrial sloughing. We present a case of intestinal endometriosis with clinical manifestation of obstruction of the colon. This disorder should be included in the differential diagnosis of fertile females presenting intestinal obstruction with no other predisposing factors.