Detection of a C-insertion polymorphism within the human tumor necrosis factor alpha (TNFA) gene

We have identified a C-insertion polymorphism in the 5'UTR of the first exon of the human tumor necrosis factor alpha (TNFA) gene. TNFA is a cytokine that plays an important role in the inflammatory response.     

Application of antigens from Taenia hydatigena cyst fluid for the immunodiagnosis of human hydatidosis

Fluid was collected from cysts of Taenia hydatigena in 60 adult sheep and fluid from each animal pooled separately. By double diffusion antigen 5 was demonstrated in all pools but one. The criteria are described for selection and standardization of these preparations for use as antigens for the immunodiagnosis of human hydatid disease. Sera from 50 persons harbouring hydatid cysts and from 50 patients with other disease conditions were examined by the arc-5 double-diffusion test, using two antigens prepared from Echinococcus granulosus and T. hydatigena cyst fluids, respectively. The results showed that a higher diagnostic sensitivity was obtained with the hydatid antigen. The significance of the findings is discussed in terms of their application to human immunodiagnosis in areas where hydatidosis, but not cysticercosis, is rare in livestock.     

Trypanosoma cruzi: 4-aminopyrazolopyrimidine in the treatment of experimental Chagas' disease

An allopurinol metabolite, 4-aminopyrazolopyrimidine, was tested on two different strains of mice (NMRI-IVIC and C57Bl/6J) that had been infected 4 days earlier with the virulent Ya strain of Trypanosoma cruzi. Low doses of 4-aminopyrazolopyrimidine (0.125-0.500 mg/kg body wt/day) for 10 days induced a significant reduction in parasitemia (direct counts and subinoculation experiments) and increased survival time (without any evidence of toxicity) compared with untreated animals. When tested in vitro, 4-aminopyrazolopyrimidine was sixfold more active than allopurinol as a trypanostatic drug. The low therapeutic doses of 4-aminopyrazolopyrimidine suggest that this drug may be useful in the treatment of acute Chagas' disease.     

THE RELATIONSHIP BETWEEN THE PROMOTION OF ELONGATION OF FERN PROTONEMATA BY LIGHT AND GROWTH SUBSTANCES

Germinating spores of the fern Onoclea sensibilis L. were grown in darkness, so that they developed as filaments (protonemata). Brief daily exposure of the filaments to red, far-red or blue light increased the rate of filament elongation. Filament elongation was also promoted by indoleacetic acid. When filament elongation was promoted with both indoleacetic acid and exposure to light, the growth promotions caused by red and far-red light were additive to auxin-induced growth. Blue light promoted elongation only at sub-optimal concentrations of auxin. Elongation induced by guanine was additive to red- and far-red-induced elongation. Gibberellic acid had no effect on elongation under any condition. Blue-light-induced elongation resembled auxin-induced elongation in its requirement for exogenous sucrose and sensitivity to inhibition by parachlorophenoxyisobutyric acid. Red and far-red light were active regardless of the presence or absence of sucrose and promoted elongation at a concentration of parachlorophenoxyisobutyric acid which completely inhibited blue-light-induced elongation.     

Vegetation on avalanche paths in the alps

Vegetation pattern on avalanche paths in the Nordkette Mountains near Innsbruck (Tyrol, Austria) was studied using transect sampling. The plant communities represent a gradient from alpine grassland (Seslerio-Caricetum sempervirentis, via grassland with Trisetum distichophyllum) and nutrient-poor grassland (Carlino-Caricetum sempervirentis) to an avalanche grassland proper. Along this gradient disturbance decreases from higher to lower elevations. The topography of the avalanche path suggests a gradient from the central zone to the edge of the path, although a floristic zonation or grouping of species across the path cannot be detected. Disturbance and local topography are the dominant factors for the vegetation pattern on the avalanche paths investigated.Abbreviations DCA= detrended correspondence analysis     

Immunohistochemical correlation of human adrenal nerve fibres and thoracic dorsal root neurons with special reference to substance P

Applying a double-labelling immunofluorescence technique, six types of substance P-containing nerve fibres were distinguished in the human adrenal gland according to the immunohistochemical colocalization of (I) calcitonin gene-related peptide (CGRP), (II) cholecystokinin, (III) nitric oxide synthase, (IV) dynorphin, (V) somatostatin, and (VI) vasoactive intestinal polypeptide. Fibre populations I to IV in their mediator content resembled the respective subpopulations of primary sensory neurons in human thoracic dorsal root ganglia, while populations V and VI revealed no correspondence with dorsal root neurochemical coding. Nerve fibres with the combination substance P/nitric oxide synthase occurred only in the adrenal cortex, whereas all other fibre types were present in both cortex and medulla. As revealed by immuno-electron microscopy, substance P-immunolabelled axon varicosities (a) exhibited synaptic contacts with medullary chromaffin cells or with neuronal dendrites, (b) were directly apposed to cortical steroid cells and (c) were separated from fenestrated capillaries only by the interstitial space. These findings provide immunochemical support for an assumed sensory innervation of the human adrenal gland, and additionally suggest participation of substance P in efferent autonomic pathways. Furthermore, the results are indicative for a differentiated involvement of substance P in the direct and indirect regulation of neuroneuronal and neuroendocrine interactions.     

Retinoic acid-induced cartilage degradation is caused by cartilage cells

Summary Cartilage cubes, prepared from the proximal epiphyses of neonatal rat humeri and consisting of cartilage tissue only, were cultured in the presence of retinoic acid. The retinoid induced the loss of metachromatic staining with toluidine blue, which correlates with the loss of proteoglycan, followed by tissue degradation processes resulting in a distinct reduction of the cartilage mass. Histologically, fibroblast-like cells appeared within chondrones, indicating a transformation of chondroblasts. Focal tissue degradation was observed after only 2 days. Electron microscopically, the clustered cells within the zone of tissue degradation were rich in various lysosomal structures indicating their lytic activity. Cycloheximide and EDTA completely blocked the retinoic acid effects suggesting that protein synthesis was required and that metalloproteinases may be involved in the degradation processes. In conclusion, with the new test system described here we demonstrated that cartilage cells themselves performed the tissue degradation induced by retinoic acid.     

Coping with potential bi‐parental inbreeding: limited pollen and seed dispersal and large genets in the dioecious marine angiosperm Thalassia testudinum

The high prevalence of dioecy in marine angiosperms or seagrasses (>50% of all species) is thought to enforce cross‐fertilization. However, seagrasses are clonal plants, and they may still be subject to sibling‐mating or bi‐parental inbreeding if the genetic neighborhood is smaller than the size of the genets. We tested this by determining the genetic neighborhoods of the dioecious seagrass Thalassia testudinum at two sites (Back‐Reef and Mid‐Lagoon) in Puerto Morelos Reef Lagoon, Mexico, by measuring dispersal of pollen and seeds in situ, and by fine‐scale spatial autocorrelation analysis with eight polymorphic microsatellite DNA markers. Prevalence of inbreeding was verified by estimating pairwise kinship coefficients; and by analysing the genotypes of seedlings grown from seeds in mesocosms. Average dispersal of pollen was 0.3–1.6 m (max. 4.8 m) and of seeds was 0.3–0.4 m (max. 1.8 m), resulting in a neighborhood area of 7.4 m² (range 3.4–11.4 m²) at Back‐Reef and 1.9 (range 1.87–1.92 m²) at Mid‐Lagoon. Neighborhood area (Na) derived from spatial autocorrelation was 0.1–20.5 m² at Back‐Reef and 0.1–16.9 m² at Mid‐Lagoon. Maximal extensions of the genets, in 19 × 30 m plots, were 19.2 m (median 7.5 m) and 10.8 m (median 4.8 m) at Back‐Reef and Mid‐Lagoon. There was no indication of deficit or excess of heterozygotes nor were coefficients of inbreeding (F_IS) significant. The seedlings did not show statistically significant deficit of heterozygotes (except for 1 locus at Back‐Reef). Contrary to our expectations, we did not find evidence of bi‐parental inbreeding in this dioecious seagrass with large genets but small genetic neighborhoods. Proposed mechanisms to avoid bi‐parental inbreeding are possible selection against homozygotes during fecundation or ovule development. Additionally, the genets grew highly dispersed (aggregation index Ac was 0.09 and 0.10 for Back‐Reef and Mid‐Lagoon, respectively); such highly dispersed guerrilla‐like clonal growth form likely increases the probability of crossing between different potentially unrelated genets.