Tenascin-C and the development of articular cartilage

In comparison to the vast literature on articular cartilage structure and function, relatively little is known about how articular cartilage forms during embryogenesis and is endowed with unique phenotypic properties, most notably the ability to persist and function throughout postnatal life. In this minireview, we summarize recent studies from our laboratory suggesting that the extracellular matrix protein tenascin-C is involved in the genesis and function of articular chondrocytes. These and other data have led us to propose that tenascin-C may be part of in vivo mechanisms whereby articular chondrocytes develop at the epiphysis of long bone models, remain functional throughout postnatal life, and avoid the endochondral ossification process undertaken by the bulk of chondrocytes located in the metaphysis and diaphysis of skeletal models.     

The effects of growth hormone in children with a GH deficiency: a report of 5 cases

The authors describe 5 cases, 3 boys and 2 girls, with idiopathic growth hormone deficiency in prepubertal age, treated with human growth hormone. In four of five cases the response to treatment with GH was relevant. Only in one case (F1) the response was negative. The results of this study confirm that rhGH is a safe and effective therapy in children with GHD.     

Correlation between serum levels of alanine aminotransferase and ferritin in male blood donors with antibody to hepatitis C virus

Chronic hepatitis C has been demonstrated to be associated with hepatic iron overload, and the hypothesis that the disease activity of hepatitis C is associated with iron cytotoxicity was tested in male volunteer blood donors. Sera with either antibody to hepatitis C virus or hepatitis B surface antigen were selected for determination of ferritin concentration and alanine aminotransferase activity. A correlation between serum ferritin concentration (Y; microgram/l) and alanine aminotransferase activity (X; IU/l) was found in donors with antibody to hepatitis C (log Y = 0.65 x log X + 0.98, r = 0.53, and P < 0.01). The correlation was lower in donors with hepatitis B surface antigen (r = 0.37; P < 0.01). Hepatitis C virus infection probably induces time-dependent iron accumulation associated with the progression of disease activity, while hepatitis B virus infection results in a variety of iron loads with different clinical features. The high disease activity related to hyperferritinemia suggests the presence of iron-induced liver damage in donors with hepatitis C.     

Solubilization of Glibenclamide with β-Cyclodextrin & its Derivatives

Gilbenclamide, a widely used potent hypoglycaemic agent was solubllized using β -Cyclodextrin and β -Cyclodextrin derivatives. Complexes were prepared by kneading method in a molar ratio of 1:1 of the drug and the cyclodextrlns respectively. The Glibenclamide β -Cyelocextrin complex was characterized and evaluated by I.R. studies, Differential Scanning Calorimotry 6 X-ray diffractometry. The in-vitro dissolution rates of drug from inclusion complexes of β Cyclodextrins and its derivatives were compared. A significant Improvement In dissolution lor, rates of Gllbenclamide was observed with Inclusion complexes of all the Cyclodextrins. However, the solubilizing effect was more in case of β-Cyclodextrin derivatives.     

10 Gbit/s optical soliton transmission over 7200 km by using amonolithically integrated MQW-DFB-LD/MQW-EA modulator light source

The authors demonstrate 10 Gbit/s optical soliton transmission in a recirculating loop through the use of a monolithically integrated MQW-DFB-LD/MQW-EA modulator light source. The timing jitter due to the Gordon-Haus effect is successfully reduced by the optical bandpass filters conventionally used in the cascaded EDFAs to avoid the accumulation of amplified spontaneous emission. The transmission distance of 7200 km is achieved at a bit error rate of 10^-9     

Biochemical identification of transmembrane segments of the Ca(2+)-ATPase of sarcoplasmic reticulum

The transmembrane segments of sarcoplasmic reticulum Ca(2+)-ATPase were determined by trypsinization of cytoplasmic side-out intact sarcoplasmic reticulum vesicles. The membrane portion of tryptic digest comprising the transmembrane fragments, joined by the intravesicular segments, was separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after labeling with fluorescein 5-maleimide in the presence of sodium dodecyl sulfate. In this way, seven fluorescent bands of tryptic fragments below 11 kDa were observed which were derived from 4 pairs of membrane spanning segments and one hydrophobic sequence at the C-terminal end. Two peptides of 10.8 and 10.6 kDa had the identical N-terminal sequence beginning at Glu826, representing the transmembrane segments M7 and M8 and their connecting loop. A band at 8.1 kDa contained one peptide beginning at Tyr36 (M1/loop/M2). A 7.7-kDa peptide starting at Leu253 (M3/loop/M4) and a 7.3-kDa peptide beginning at Ala752 (M5/loop/M6) were also observed. A band at 6.7 kDa contained two peptides, one beginning at Ser48 (M1/loop/M2) and another beginning at Tyr763 (M5/loop/M6). In addition, a 4-kDa peptide beginning at Met925 was observed. The size of this peptide did not allow for a complete pair of transmembrane segments, but this peptide could have been derived from trypsinolysis between the last pair of membrane spanning segments. These data therefore provide biochemical evidence for at least 8 transmembrane segments and perhaps two more at the C-terminal end of the enzyme.     

Cloning and characterization of the Inc A/C plasmid RA1 replicon

The Inc A/C plasmids, like Inc P and Inc Q plasmids, have a broad host range. However, their maintenance functions remain to be studied. An autoreplicative region of 2.79 kb named RepA/C, able to replicate both in the family Enterobacteriaceae and in Pseudomonas spp., was isolated and sequenced. The stability, copy number, and incompatibility expression of this replicon were determined. RepA/C and a nonautoreplicative fragment of 16 kb of this replicon were used as probes and showed specific hybridizations with the Inc P3-A/C plasmids from Pseudomonas spp. and members of the Enterobacteriaceae. These probes could be used as tools for identification of the plasmids of this epidemiologically important Inc group.     

Expression of laminin and nidogen genes during the postimplantation development of the mouse placenta

The expression patterns of laminin A, B1, B2, and nidogen genes were identified by in situ hybridization in postimplantation mouse extraembryonic tissues and maternal decidua during the period when the chorioallantoic placenta is established. Laminin and nidogen genes were not coordinately expressed either in the decidua or in trophoblast cells, indicating that these genes are regulated independently in these cell types during the establishment of the placenta. Laminin A mRNA was absent from the decidua except in the outer layer of cells adjacent to the myometrium and in the central decidual zone adjacent to the remnant of the uterine epithelium on Day 9. At this stage laminin B1, B2, and nidogen genes were strongly expressed in these cells and also in other regions of the decidua. Laminin B1 mRNA was present at higher levels in the decidua capsularis than in the decidua basalis, while nidogen mRNA showed highest expression in the decidua basalis. Laminin B2 mRNA was produced uniformly throughout the decidua at very high levels, suggesting that laminin B2 chains may be an important component of the decidual matrix. By Day 11, the nidogen gene was expressed only in endothelial cells lining the maternal blood spaces within the decidua. Laminin B1 and nidogen mRNAs were found at high levels within trophoblast giant cells at all stages, while laminin A mRNA was detected in trophoblast giant cells at later stages and laminin B2 mRNA was not produced in high levels by these cells. The patterns of gene expression show a very high degree of regional specialization, suggesting that the extracellular matrices in different regions of the decidua and extraembryonic membranes are likely to be composed of quite different ratios of laminin and nidogen polypeptides.(ABSTRACT TRUNCATED AT 250 WORDS)     

Climatic solar roof: an ecological alternative to heat dissipation in buildings

A new system based on the harnessing of solar and wind power is presented for heat dissipation in air conditioning facilities. The innovation offered by the new system is the integration of two well-known subsystems: a cooling tower and a solar chimney which increases the air flow without the use of electric power. The system is described and presented together with a model for its study. The field data acquired from the prototype built in southern Spain establishes the actual potential of the system, which provides a new approach to a sustainable technological development.