Organization of histamine-containing neurons in the brain of the crested newt,Triturus carnifex

The distribution of immunoreactivity for histamine was studied in the brain of the urodele Triturus carnifex using the indirect immunofluorescence method. Histamine-immunoreactive cell bodies were localized in the caudal hypothalamus within the dorsolateral walls of the infundibular recesses. These immunoreactive cell bodies were pear-shaped, bipolar and frequently of the cerebrospinal-fluid-contacting type. Histaminergic nerve fibers were detected in almost all parts of the brain. Dense innervation was seen in the telencephalic medial pallium and ventral striatum, the neuropil of the preoptic area, the septum, the paraventricular organ, the posterior commissure, the caudal hypothalamus, the ventral and lateral mesencephalic tegmentum. Medium density innervation was observed in the lateral mesencephalic tegmentum and optic tectum. Poor innervation was present in the telencephalic dorsal pallium and in the central gray of the medulla oblongata. Few fibers occurred in the olfactory bulbs and in the telencephalic lateral pallium. Double immunofluorescence staining, using an antibody against tyrosine hydroxylase, showed that histamine-immunostained somata and those containing tyrosine-hydroxylase-like immunoreactivity were co-distributed in the tuberal hypothalamus. No co-occurrence of histamine-like and tyrosine hydroxylase-like immunostaining was seen in the same neuron. The pattern of histamine-immunoreactive neurons in the newt was similar to that described in other vertebrates. Our observations, carried out on the apparently simplified brain of the newt confirm that the basic histaminergic system is well conserved throughout vertebrates.     

Genetic mapping of the erythropoietin receptor gene

We describe a novel, highly informative (polymorphism information content, PIC, = 0.86) simple sequence repeat polymorphism at the 5 end of the gene encoding the human erythropoietin receptor (EPOR) previously assigned to 19pl3.2 by in situ hybridization. Fourteen different allelic size variants were identified in 12 families of the CEPH (Centre d'Etude du Polymorphisme Humain) family panel of 40 families. In pairwise linkage 16 of the 65 chromosome 19 markers reported to the CEPH database gave a lod score exceeding 3.0 when tested against EPOR. The most likely location of EPOR within a framework of 10 markers including orientation and information on reported physical assignments was pter-[INSR-D1 9S177-D19S176]-D 19S24-LDLR-EPOR-cen-D-19S7-D19S49-D19S75-D19S47-APOC2-qter, placing EPOR as the most proximal of the tested loci on the short arm. On an 11-point map the position and order for all other loci except INSR were supported by the data with odds exceeding 1,000:1. The polymorphism at the 5 end of EPOR should provide a useful landmark marker for future mapping studies of this region.     

Distribution and disappearance of the radiolabeled carbon derived from L-arginine and taurine in the mouse

L-arginine and taurine are still in the center of physiological and pharmacological research. Although the fate of nitrogen of both compounds and of the ³⁵S-taurine is well-documented, the fate of the carbon skeleton has not been elucidated yet. We studied the organ distribution of ¹⁴C arginine and ¹⁴C taurine over time in the mouse using whole body autoradiography with densitometric image analysis. We describe different organ distribution patterns. Kidney, heart, lung, the Harderian gland, the central nervous system, intestine and testis showed a comparable pattern of arginine disappearance in contrast to rapid disappearance in the salivary gland and the accumulation pattern in bone and spleen. Data on ¹⁴C taurine of liver, kidneys, lung, testis and Harderian gland resembled the arginine pattern; Accumulation of taurine carbon was found in salivary gland, bone, intestine, heart and brain. Our studies challenge and demand further related studies to obtaining more information on the fate of the carbon skeleton of these amino acids.     

Processing of McCoy cell cultures infected with Chlamydia trachomatis: sequential isolation of chlamydial elementary bodies and lipopolysaccharide

Abstract Triton X-100 (TX100) enhances the liberation of chlamydial elementary bodies (EB) from host cells and dissolves the host cell membrane. In the presence of TX100 only differential centrifugation is needed to isolate reasonably pure EBs. The remaining high-speed supernatant still contains a large part of the chlamydial lipopolysaccharide (LPS), which can be isolated with the standard phenol-chloroform-petroleum ether extraction.     

The lacrimal glands of the rat and the guinea pig are innervated by nerve fibers containing immunoreactivities for substance P and vasoactive intestinal polypeptide

Summary Two neuropeptides, substance P and vasoactive intestinal polypeptide, have been shown to increase secretion of exocrine glands. We have studied immunohistochemically the intra- and exorbital lacrimal glands of the rat and the guinea pig for the presence of substance P-like and vasoactive intestinal polypeptide-like immunoreactive (SPLI and VIPLI, respectively) nerve fibers. Both SPLI and VIPLI nerve fibers were found surrounding glandular acini, secretory ducts and blood vessels. Their distribution, however, was uneven. The SPLI fibers predominated around the ducts whereas VIPLI fibers predominated around acini. The results suggest that the two neuropeptides may both regulate the lacrimal secretion, but they may have two different sites of actions because they prevail in different locations.     

Zooplankton in the Vasikkalampi pond, a warm water effluent recipient in Central Finland

Seasonal and vertical fluctuations of zooplankton species composition,biomass, and production were monitored by weekly sampling duringa two year period in one eutrophic pond in Central Finland.The study was one part of a more comprehensive study programto investigate the effects of warm water effluents from onesmall thermal power plant (35 MW) on the pond ecosystem. Becauseof the circulation of the pond water through the pumps in thepower plant the crustacean populations were very sparse in planktonduring the seasons the power plant was in operation (late Augustto May). During that time rotifers were dominant and some speciesreached very high densities (e.g., Keratella cochlearis s.l.ca. 15 000 ind. l^–1 in sping). In summer months Asplanchnapriodonta, Ceriodaphnia quadrangula, Bosmina longirostris, Mesocyclopsleuckarti and Thermocyclops oithonoides were dominant. A totalof 96 planktonic and meroplanktonic taxa were identified (26ciliates, 46 rotifers, 21 cladocerans and 3 copepods). The dryweight biomass of total zooplankton was 10 mg m^–3 in wintermonths, 10–100 mg m^–3 in spring and 300–1000mg m^–3 in summer. The total yearly production of zooplanktonwas 8552 mg dry wt m^–3 a^–1 in 1979 and 8440 mg drywt m^–3 a^–1 in 1980, from which the proportion ofrotifers was 33–39%, cladocerans 52–58% and copepods8.6 –9.4%. The winter production was 0.2–0.5% ofthe total yearly production, that of spring and autumn togetherwas 8.1–10.4% and the remainder (89–91%) was summerproduction.     

Distribution of spontaneous chromosome breaks in human chromosomes

Summary Localization of chromosome breaks in human chromosomes was analyzed in 264 peripheral lymphocyte cultures. Three hundred and sixty-nine chromosome breaks could be exactly localized to a chromosome band or region of the Paris Conference nomenclature. The distribution of breaks in the chromosome regions was found to be nonrandom. Chromosome 3 alone had 23% of the breaks and region 3p2 had 13% of the total breaks. Some other chromosome regions, such as 5p1, 9q1, 14q2, and 16q2 also displayed clustering of breaks. Sex chromosomes had less breaks than expected. Spontaneous chromosome breaks were almost exclusively located in the lightly stained G bands.Supported by grants from the Foundation for Pediatric Research and Research Foundation of Orion Corporation Ltd.     

Lakes as nitrous oxide sources in the boreal landscape

Estimates of regional and global freshwater N₂O emissions have remained inaccurate due to scarce data and complexity of the multiple processes driving N₂O fluxes the focus predominantly being on summer time measurements from emission hot spots, agricultural streams. Here, we present four‐season data of N₂O concentrations in the water columns of randomly selected boreal lakes covering a large variation in latitude, lake type, area, depth, water chemistry, and land use cover. Nitrate was the key driver for N₂O dynamics, explaining as much as 78% of the variation of the seasonal mean N₂O concentrations across all lakes. Nitrate concentrations varied among seasons being highest in winter and lowest in summer. Of the surface water samples, 71% were oversaturated with N₂O relative to the atmosphere. Largest oversaturation was measured in winter and lowest in summer stressing the importance to include full year N₂O measurements in annual emission estimates. Including winter data resulted in fourfold annual N₂O emission estimates compared to summer only measurements. Nutrient‐rich calcareous and large humic lakes had the highest annual N₂O emissions. Our emission estimates for Finnish and boreal lakes are 0.6 and 29 Gg N₂O‐N/year, respectively. The global warming potential of N₂O from lakes cannot be neglected in the boreal landscape, being 35% of that of diffusive CH₄ emission in Finnish lakes.     

Reactions of Purine Nucleosides with Aqueous Alkalies: The Effect of the C6 Substituent on the Kinetics of the Multistage Pathway

Abstract

Kinetics of the reactions of 6-substituted 9-(β-Q-ribofuranosyl)purines with aqueous alkalies have been studied liquid chromatographicaIly.