Metoclopramide increases plasma but not cerebrospinal fluid vasopressin levels in man: study in hydrocephalic patients.

Arginine vasopressin (AVP) concentrations were determined in plasma and in cerebrospinal fluid (CSF) in 8 adult male patients suffering from hydrocephalus of various etiologies, before and after intravenous administration of 10 mg metoclopramide. Metoclopramide was able to increase the plasma (2.6 +/- 0.2 ng/l in basal conditions and 6.1 +/- 0.6 ng/l at 30 min) but not the CSF AVP levels. The results suggest that the neurons which secrete AVP into the CSF may be functionally different from those secreting into the peripheral circulation.     

An Ecological Imbalance Induced by a Non-Native Species: The Manila Clam in the Venice Lagoon

Among the 19 non-native species of marine invertebrates which have invaded the Venice Lagoon and have established populations, Ruditapes philippinarum, deliberately introduced in 1983, is surely the most successful species. According to the hypothesis that alien species invasion could be favoured by an altered ecological, chemical or physical state of the system induced by anthropogenic disturbance, R. philippinarum turned out to be ‘the right species at the right moment’. By comparing historical data (1968, 1985, 1990) with 1999 data, changes in macrobenthic community, in particular bivalve molluscs, of the lagoon induced by R. philippinarum introduction and subsequent clam exploiting activity were assessed. It has been possible to describe a sharp reduction, both in terms of distribution area and density, of all other filter feeder bivalves. Moreover, by using the clearance rate of the most abundant bivalve species in 1990 and 1999 (Cerastoderma glaucum and R. philippinarum, respectively), it was possible to estimate that the filtration capacity, expressed as l h⁻¹ m⁻², has more than doubled. This has altered the functioning of the ecosystem, resulting in a stronger benthic–pelagic coupling. In this context, R. philippinarum attains control of the system. Considering all this, it is possible to state that the Venice Lagoon ecosystem has entered into a new state, probably more resistant but less resilient, with implications for future management choices.     

A Combined Approach for the Assessment of Cell Viability and Cell Functionality of Human Fibrochondrocytes for Use in Tissue Engineering

Temporo-mandibular joint disc disorders are highly prevalent in adult populations. Autologous chondrocyte implantation is a well-established method for the treatment of several chondral defects. However, very few studies have been carried out using human fibrous chondrocytes from the temporo-mandibular joint (TMJ). One of the main drawbacks associated to chondrocyte cell culture is the possibility that chondrocyte cells kept in culture tend to de-differentiate and to lose cell viability under in in-vitro conditions. In this work, we have isolated human temporo-mandibular joint fibrochondrocytes (TMJF) from human disc and we have used a highly-sensitive technique to determine cell viability, cell proliferation and gene expression of nine consecutive cell passages to determine the most appropriate cell passage for use in tissue engineering and future clinical use. Our results revealed that the most potentially viable and functional cell passages were P5–P6, in which an adequate equilibrium between cell viability and the capability to synthesize all major extracellular matrix components exists. The combined action of pro-apoptotic (TRAF5, PHLDA1) and anti-apoptotic genes (SON, HTT, FAIM2) may explain the differential cell viability levels that we found in this study. These results suggest that TMJF should be used at P5–P6 for cell therapy protocols.     

Cytochemical localization of alkaline phosphatase and ouabain-sensitive K+-dependent p-nitrophenylphosphatase activities in brain capillaries of the newt

The ultrastructural localization of alkaline phosphatase and K+-NPPase was investigated in brain capillaries of newt by a cytochemical study using whole brain perfusion. The alkaline phosphatase activity was present in both luminal and antiluminal membranes of the endothelial cells. By contrast, the K+-NPPase was located only in antiluminal membranes of the brain capillaries. This distinct enzymatic distribution suggested that the luminal and antiluminal membranes are functionally different. The role of alkaline phosphatase and K+-NPPase in the blood brain barrier is discussed.     

Effect of ring width, cambial age, and climatic variables on the within-ring wood density profile of Norway spruce Picea abies (L.) Karst.

Studying the effects of dendrometric and climatic variables on within-ring density variations needs flexible and interpretable models. We described the within-ring density profile using a piecewise linear regression and studied its dependence on (1) dendrometric variables such as cambial age (CA) and ring width (RW), and (2) climatic variables. Based on X-ray analysis of 5,191 Norway spruce rings, a six-parameter three-segmented model was fitted on each within-ring density profile. Each model parameter was related to dendrometric and climatic variables using multiple linear regressions. Then, these models were assembled in two models relating the within-ring density profile to (1) RW and CA (model M1), and (2) climatic variables (model M2). M1 showed an R ² of 83.4 % and a residual standard error of 68.5 kg m^?3. Larger rings were associated with a decrease of latewood proportion and mean ring density. Rings with high CA were characterised by high maximum ring density. M2 showed an R ² of 60.9 % and a residual standard error of 94.9 kg m^?3. Warm summers increased the maximum ring density. Years with favourable water status decreased mean ring density. The piecewise linear models allowed the classification of within-ring density profiles in three types. Considering CA and RW led to the most explicative model since RW described many processes such as silviculture or climate. Earlywood density was impacted by water status while latewood density was conditioned by both temperatures and water status. Our approach may be used for the identification of within-ring density fluctuations or to assess the effects of silviculture or global change on the within-ring density profile.     

Trisomy-8 mosaicism: Report of a case

Summary An 8-year-old male with mental retardation, speech difficulties, and minor congenital anomalies is presented. The clinical findings suggest the trisomy-8 syndrome. The karyotype indicates trisomy-8 mosaicism with trisomic as well as normal cell lines in blood lymphocytes.