Tetranectin immunoreactivity in normal human tissues. An immunohistochemical study of exocrine epithelia and mesenchyme

A recently discovered human plasma protein, tetranectin (TN), which has previously been demonstrated immunohistochemically within various endocrine tissues, was in this study identified in an additional number of epithelial and mesenchymal cells by two polyclonal antibodies and one monoclonal using the conventional immunoperoxidase staining technique and a modification of the CLONO-GLAD procedure. TN was found in endothelial and epithelial tissues, particularly in cells with a high turn-over or storage function such as gastric parietal and zymogenic cells, absorptive surface epithelium of the small intestine, ducts of exocrine glands and pseudostratified respiratory epithelium. Also mesenchymal cells produced a TN positive staining reaction, which was most conspicuous in mast cells, but also present in some lymphocytes, plasma cells, macrophages, granulocytes, striated and smooth muscle cells and fibroblasts. SDS-PAGE and Western blotting analysis of cultured human embryonal fibroblasts (WI-38) showed that the cells besides TN contain another protein with a molecular weight of 82,000. As this protein, however, reacted with our affinity purified antibodies it probably represents a precursor of TN or a protein with a molecular weight of approximately 60,000, which is covalently linked to TN. This and the fact that TN shows amino acid sequence homologies to the carboxyterminal part of the asialo-glycoprotein receptor and a cartilage proteoglycan core protein as well a binding affinity to plasminogen points to TN as being part of a larger molecule, which possibly has been cleaved by proteolysis at the cellular site and then passed into the blood, where it polymerizes into a tetramer.     

Renin-positive granulated Goormaghtigh cells

Summary It is difficult to distinguish between Goormaghtigh cells (G-cells) and media cells of the glomerular arterioles at the border of the Goormaghtigh cell field. Consequently, it has been unclear whether renin-positive G-cells are normally present and also whether renin-producing cells are recruited from the pool of renin-negative G-cells upon stimulation of the renin-angiotensin system (RAS). In the present study, immunohistochemical and electron-microscopic experiments have been carried out on serially sectioned kidney biopsies from four patients with pseudo-Bartter syndrome. The results strongly suggest that with longlasting stimulation of the RAS all renin-negative (secretory resting) G-cells are ultimately converted into renin-producing granular cells.Synonymous with extraglomerular mesangial cells     

Host plant recognition in monophagous weevils: specificity in feeding responses of Ceutorhynchus constrictus and the variable effect of sinigrin

Host plant relations of the monophagous weevil Ceutorhynchus constrictus Marsh. (Coleoptera: Curculionidae: Ceutorhynchinae) feeding on garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Cruciferae) were studied in the laboratory. Most other crucifers were rejected in choice tests using garlic mustard as a reference plant, but Brassica nigra, Sinapis alba and Thlaspi arvense were as acceptable as the host plant. Flowering plants of Descurainia sophia were acceptable while young plants of this species were not. The most important feeding stimulants in extracts of garlic mustard were uncharged, water soluble compounds. The most abundant glucosinolate in garlic mustard, sinigrin, was a feeding stimulant, too. However, the feeding stimulatory activity of sinigrin was only expressed in the presence of still unidentified uncharged compounds from garlic mustard leaves. Host plant relations in monophagous crucifer-feeding insects is discussed in relation to the distinctness of glucosinolate patterns found in their host plants.

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Zusammenfassung Ceutorhynchus constrictus Marsh. (Coleoptera: Chrysomelidae: Ceutorhynchinae) ist ein monophager Rüsselkäfer, der an Knoblauchhederich frisst. Das Wirtswahl-Verhalten dieses Käfers ist im Labor untersucht worden. Die meisten Crucifiren waren im Wahlversuche nicht akzeptiert, wenn Knoblauchhederich als Vergleichspflanze vorhanden war. Von Brassica nigra, Sinapis alba, und Thlaspi arvense wurden im Vergleich gleiche Mengen verzehrt wie von der Wirtspflanze. Blühende Descurainia sophia Pflanzen wurden, im Gegensatz zu Jungpflanzen der gleichen Art, angenommen. Die wichtichsten Phagostimulanten in Extrakten von Knoblauchhederich-Blättern waren ungeladene, wasserlösliche Substanzen. Das häufigste Glukosinolat im Knoblauchhederich, Sinigrin, war auch ein Phagostimulant. Doch war die phagostimulierende Wirkung von Sinigrin nur in Kombinationen mit noch nicht identifizierten, ungeladenen Substanzen aus Knoblauchhederich-Blätter nachweisbar. Wirtspfanzen-Beziehungen von monophagen Insekten werden diskutiert im Zusammenhang mit der Eigenart des Glukosinolat-Inhaltes ihrer Wirtspflanzen.

     

Beta-oxidation of medium chain (C8-C14) fatty acids studied in isolated liver cells

The beta-oxidation and esterification of medium-chain fatty acids were studied in hepatocytes from fasted, fed and fructose-refed rats. The beta-oxidation of lauric acid (12:0) was less inhibited by fructose refeeding and by (+)-decanoyl-carnitine than the oxidation of oleic acid was, suggesting a peroxisomal beta-oxidation of lauric acid. Little lauric acid was esterified in triacylglycerol fraction, except at high substrate concentrations or in the fructose-refed state. With [1-14C]myristic acid (14:0), [1-14C]lauric acid (12:0), [1-14C]octanoic acid (8:0) and [2-14C]adrenic acid (22:4(n - 6] as substrate for hepatocytes from carbohydrate-refed rats, a large fraction of the 14C-labelled esterified fatty acids consisted of newly synthesized palmitic acid (16:0), stearic acid (18:0) and oleic acid (18:1) while intact [1-14C]oleic acid substrate was esterified directly. With [9,10-3H]myristic acid as the substrate, small amounts of shortened 3H-labelled beta-oxidation intermediates were found. With [U-14C]palmitic acid, no shortened fatty acids were detected. It was concluded that when the mitochondrial fatty acid oxidation is down-regulated such as in the carbohydrate-refed state, medium-chain fatty acids can partly be retailored to long-chain fatty acids by peroxisomal beta-oxidation followed by synthesis of C16 and C16 fatty acids which can then stored as triacylglycerol.     

A murine model for the study of the impact ofAspergillus fumigatus inoculation on the foeto-placental unit

The mycotoxin cyclopiazonic acid (CPA) is a potential contaminant of processed foods, grain and poultry. Twelve male Sprague-Dawley rats were given oral doses of 0, 0.2, 0.6, 2.0 or 4.0 mg CPA/kg body weight/day for 13 consecutive weeks to study its potential subchronic toxicity. No dose-related mortality or morbidity occurred. General appearance, behavior, body weight gain and food consumption of all groups were similar. CPA had no definite adverse hematologic or serum chemistry effects, although serum creatinine concentrations of rats given 2.0 and 4.0 mg CPA/kg BW were increased after seven and 13 weeks. Mild to focally moderate acute inflammation of the lamina propria and submucosa of the gastric epithelium was found in animals given 0.6 mg CPA/kg BW. No other dose-related microscopic lesions were found. Ultrastructural examination of the livers revealed subtle disruption of the cisternal pattern of the endoplasmic reticulum with ribosomal detachment in animals receiving 4.0, but not 2.0, mg CPA/kg BW. These data suggest that the toxic effects in rats of repeated, daily oral exposure to CPA may be less than previously reported. The possible relationship between toxicity and CPA epimerization is considered.     

A novel RNA helicase gene tightly linked to the Triplo-lethal locus of Drosophila.

The Triplo-lethal (Tpl) locus of Drosophila is the only known locus which is lethal when present in three copies rather than the normal two. After recovering a hybrid-dysgenesis-induced mutation of Tpl we used a rapid combination of transposon tagging, chromosome microdissection and PCR to clone the P element that had transposed into the Tpl region. That P element is located within the gene for a new and unique member of the RNA helicase family. This new helicase differs from all others known by having glycine-rich repeats at both the amino and carboxyl termini. Curiously, genetic analysis shows that the P element inserted into this gene is not responsible for the Tpl mutant phenotype. We present possible explanations for these findings.     

The effect of ranitidine on cellular immunity in patients with multiple myeloma

Summary Multiple myeloma is characterized by an increased susceptibility to infections and to other malignancies. In a double-blind, placebo-controlled study the potential impact of immunomodulation by ranitidine was studied in 20 patients with multiple myeloma. Three patients were untreated, while 17 after previous cytotoxic therapy were in a stable phase of their disease. All were without clinical signs of infections and at that time had not been treated with other immunomodulating agents. The patients were randomized to oral ranitidine 300 mg twice a day for 21 days or placebo, and several immunological parameters related to multiple myeloma were studied. The blood monocyte chemotactic response was improved in patients treated with ranitidine, and superoxide anion production increased from 2.02 nmol/min to 3.86 nmol/min (median values), while it was unchanged in patients given placebo (2.19–2.25 nmol/min) (P <0.005 between groups). Among ranitidine-treated patients spontaneous NK cell activity was unchanged, while in vitro interleukin-2- and interferon--stimulated NK cell activity decreased (P <0.03, respectively). As production of oxygen radicals constitutes an important mechanism of monocyte killing activity against microorganisms and probably against malignant cells, it is suggested that ranitidine may be of beneficial impact in the treatment of multiple myeloma.     

Detection of proopiomelanocortin mRNA by in situ hybridization, using a biotinylated oligodeoxynucleotide probe and avidin-alkaline phosphatase histochemistry

A synthetic 24-mer oligodeoxynucleotide complementary to the region of proopiomelanocortin (POMC) mRNA that codes for the MSH core sequence (alpha MSH/ACTH[4-11]), was synthesized and labelled in the 3'-end by use of terminal transferase. Probes tailed with either [3H]- or biotin-labelled nucleotides could be used for in situ hybridization studies. Biotinylated probes, hybridized to mouse and rat pituitary sections, were detected by avidin-alkaline phosphatase or streptavidin-alkaline phosphatase procedures and development in 5-bromo-4-chloro-3-indolyl phosphate (BCIP)-nitroblue tetrazolium (NBT). Proteinase K pretreatment of sections produced a drastic enhancement of the signal obtained, particularly in strongly fixed, paraffin-embedded material. The non-radioactive in situ hybridization technique compared favourably to radioactive in situ hybridization in terms of rapidity and precision of the localization. Controls involved deletion of the probe to prove that other components of the reaction sequence did not yield stain, digestion with RNase to prove that tissue RNA was necessary to bind the probe, prehybridization (blocking) with unlabelled probe to prove that the biotinylated probe reacted with its anti-sense region and not its tail and Northern blotting to show that the probe reacted with only one species of pituitary RNA, having the size of mouse pituitary POMC mRNA. In addition, adrenalectomy, known to increase anterior lobe POMC levels, resulted in both increased numbers and increased intensity of positive corticotroph-like cells. Synthetic oligodeoxynucleotides labelled with biotin appear to constitute attractive reagents for in situ hybridization studies when supported by appropriate control procedures.     

Oxygen control prevents denitrifiers and barley plant roots from directly competing for nitrate

Abstract Two denitrifying bacteria ( Pseudomonas chlororaphis and P. aureofaciens ) and a plant (barley, Hordeum vulgare ) were used to study the effect of O₂ concentration on denitrification and NO₃⁻ uptake by roots under well-defined aeration conditions. Bacterial cells in the early stationary phase were kept in a chemostat vessel with vigorous stirring and thus a uniform O₂ concentration in the solution. Both Pseudomonads lacked N₂O reductase and so total denitrification could be directly measured as N₂O production.
Denitrification decreased to 6–13% of the anaerobic rate at 0.01% O₂ saturation (0.14 μM O₂) and was totally inhibited at 0.04% O₂ saturation (0.56 μM O₂). In this well-mixed system denitrification was 10-times more oxygen sensitive than stated in earlier reports. Uptake of nitrate by plants was measured in the same system under light. The NO₃⁻ uptake rate decreased gradually from a maximum in 21% O₂-saturated medium (air saturated) to zero at 1.6% O₂ saturation (22.4 μM O₂). Owing to the very different non-overlapping oxygen requirements of the two processes, direct competition for nitrate between plant roots and denitrifying bacteria cannot occur.     

Hematozoan parasites of Rio Grande wild turkeys from southern Texas

One hundred twenty-three of 300 blood samples (41%) taken from Rio Grande wild turkeys (Meleagris gallopavo intermedia) from three locations in southern Texas (Welder Wildlife Refuge, Chaparrosa Ranch, and Campo Alegre Ranch) and subinoculated into domestic broad-breasted white turkey poults were positive for a Plasmodium (Novyella) sp. Analysis of blood films from 350 turkeys revealed Haemoproteus meleagridis in 76% of the birds. A significantly greater mean parasite intensity was observed in birds from Welder Wildlife Refuge. Birds from the Campo Alegre Ranch exhibited a significantly higher prevalence of H. meleagridis than birds from Chaparrosa. The Plasmodium sp. was infective for canaries (Serinus canaria), bobwhites (Colinus virginianus), and ring-necked pheasants (Phasianus colchicus), but would not produce infection in white leghorn chickens (Gallus gallus) or Coturnix quail (Coturnix coturnix). Attempts to infect Culex tarsalis and C. pipiens were unsuccessful. Asexual erythrocytic synchrony was not observed when blood-induced infections were monitored in two domestic turkey poults every 4 hr for 72 hr. Exoerythrocytic stages were not found upon examination of impression smears and tissue samples taken from brain, liver, spleen, kidney, lung, and bone marrow. The Plasmodium sp. is most similar morphologically to three species in the subgenus Novyella, P. hexamerium, P. vaughani, and P. kempi. The most striking similarities are to P. hexamerium, and involve mean merozoite number, erythrocytic schizont location, and vertebrate host susceptibility. It differs from P. vaughani in being able to infect turkeys and in type of parasitized erythrocytes. Differences to P. kempi include mean merozoite number, and ability to infect pheasants, and its inability to develop in C. pipiens and C. tarsalis.