The effects of vasopressin on renal sodium excretion in pigs given intravascular hypertonic salt loads

Young pigs of about 25-30 kg liveweight were given intravenous infusions of a hypertonic sodium chloride solution (4-6 mol.1(-1)) at rates varying from 2-6 mmol.min-1. Such infusions resulted in a marked increase in the urine flow and in urinary sodium excretion, the size of these increases being proportional to infusion rate. Circulating vasopressin levels were also markedly increased, the size of these increases being the same as those seen in other pigs given exogenous vasopressin in amounts which were shown to increase urinary sodium excretion. This suggests that vasopressin was probably contributing to the increase in renal sodium excretion seen in those pigs given the intravenous salt loads.     

Renovascular Hypertension: Pathophysiology,Diagnosis, and Treatment

Renovascular hypertension can result from renal artery lesions involving the main renal artery, or its branches. It is generally felt that the elevation of blood pressure results from excessive systemic vasoconstriction secondary to enhanced renin secretion by one or part of one kidney. Renin secretion is enhanced because of constriction of the renal artery and resultant intrarenal ischemia. Clinically patients cannot be distinguished from those with essential hypertension and diagnosis must be made with arteriography although urography and isotope renography may suggest the diagnosis. Surgical cure can be predicted if differential renal vein renin ratios lateralize but a non-lateralizing study does not necessarily mean that surgery will fail. In properly selected patients, surgical results are excellent.     

Enalapril in the treatment of hypertension with renal artery stenosis.

The converting enzyme inhibitor enalapril, in single daily doses of 10-40 mg, was given to 20 hypertensive patients with renal artery stenosis. The blood pressure fall six hours after the first dose of enalapril was significantly related to the pretreatment plasma concentrations of active renin and angiotensin II and to the concurrent fall in angiotensin II. Blood pressure fell further with continued treatment; the long term fall was not significantly related to pretreatment plasma renin or angiotensin II concentrations. At three months, 24 hours after the last dose of enalapril, blood pressure, plasma angiotensin II, and converting enzyme activity remained low and active renin and angiotensin I high; six hours after dosing, angiotensin II had, however, fallen further. The rise in active renin during long term treatment was proportionally greater than the rise in angiotensin I; this probably reflects the fall in renin substrate that occurs with converting enzyme inhibition. Enalapril alone caused reduction in exchangeable sodium, with distinct increases in serum potassium, creatinine, and urea. Enalapril was well tolerated and controlled hypertension effectively long term; only two of the 20 patients required concomitant diuretic treatment.     

The population dynamics and sexual strategy of Anodonta woodiana (Bivalvia: Unionacea) in Plover Cove Reservoir, Hong Kong

A 12-month investigation of the population dynamics, growth, ageing, reproduction and sexuality of Anodonta woodiana (Lea, 1834) in Plover Cove Reservoir, Hong Kong, has been undertaken. Recruitment occurs in the summer, May through July being the period of peak incidence of glochidia on captive fish hosts. Juveniles grow rapidly to a shell length of 30 mm and are sexually mature by the following spring. A study of the population structure of A. woodiana indicated that most animals were less than 8 years old. Results of a Walford plot for this species indicated a maximum theoretical shell length (in Plover Cove) of 162·5 mm and a life span of approximately 12 years; the latter is in good agreement with age estimates for European unionids.
Anodonta woodiana is dioecious with females predominating in a ratio of 60:40. A very small number of individuals (0·3%) are hermaphrodite. Males possess mature gonads throughout the year whereas females come into reproductive condition during the spring. There was no evidence of shell form sexual dimorphism, as has been recorded for other unionaceans.
The reproductive strategy and time of gonad maturation of A. woodiana is compared with that of unionids from elsewhere and with other fresh water bivalves from southern China.     

An ordered arrangement of chromosomes in the somatic nucleus of common wheat Triticum aestivum L.

Spatial relationships between chromosomes of the same genome, both homologous and non-homologous, were studied in root-tip cells of common wheat, Triticum aestivum (2n = 6x = 42). Mean distance between members of all the 21 homologous pairs (seven in each of the three genomes) and of 45 out of the 63 possible non-homologous combinations of two (21 in each genome) were determined. To minimize disruption of nuclear chromosomal arrangement, the cells were pretreated with cold temperature either in tap water or in a physiological medium (White solution) and distances between cytologically marked chromosomes were measured at metaphase. Comparison of distances for homologues with those for non-homologues indicated clearly that, within each genome, the homologous chromosomes were significantly closer to one another than were the non-homologues. Distances between homologues were similar in all three genomes, as were distances between non-homologues. The data are consistent with the hypothesis that the chromosomes of each genome of common wheat are arranged in the somatic nucleus in a highly specific ordered pattern. In this hypothetical arrangement, homologous chromosomes are closely associated, while the nonhomologues occupy definite positions with respect to one another. The universality of the phenomenon and its cellular mechanism and biological significance are discussed.     

Binding of plasminogen activator inhibitor type-1 to extracellular matrix of Hep G2 cells. Evidence that the binding protein is vitronectin.

Catabolism of plasminogen activators by Hep G2 cells is mediated by a specific receptor which recognizes complexes of these serine proteases with their physiological inhibitor, plasminogen activator inhibitor type-1 (PAI-1). This catabolic process is initiated by interaction of exogenous plasminogen activators with bioactive PAI-1, which is secreted and localizes in an active form to the extracellular matrix (ECM) of Hep G2 cells. We now report that vitronectin (VN) mediates the specific binding of PAI-1 to the ECM of these cells. Purified bovine or human VN competes for specific binding of PAI-1 to Hep G2 ECM, and ligand blotting reveals specific binding of PAI-1 to ECM-associated VN. Hep G2 cells secrete both VN and PAI-1, and pulse-chase studies strongly suggest that these proteins associate only following secretion. Although Hep G2 cell-derived VN does not significantly bind to ECM in vitro, 30-40% of endogenous PAI-1 binds to the ECM, even in the presence of human serum, suggesting that ECM-associated VN is entirely derived from bovine serum. PAI-1 was localized by indirect immunofluorescence to ECM beneath cells and at cell margins, whereas VN exhibited a uniform distribution throughout the growth substratum. VN associated with the ECM may confer retention and bioactivity to PAI-1, potentially facilitating both pericellular regulation of plasmin generation and the rapid hepatic clearance of plasminogen activators.     

The horseradish tree,Moringa pterygosperma (Moringaceae)—A boon to Arid Lands?

The horseradish tree (Moringa pterygosperma,) is being introduced into drought-ridden lands to augment the local food and fodder supply. The tree grows up to 5 m per year. The foliage is high in calcium and has half the oxalates of amaranth. Seeds yield edible oil and the seed meal is used as fertilizer and as a coagulant to clarify turbid water. The philanthropic center, ECHO (Educational Concerns for Hunger Organization), North Fort Myers, Florida, receives many requests for seeds. A missionary in Mali wrote: “The seeds you sent arrived during the worst year of 14 years of dry weather. Only the moringa survived, and they have flourished. ”Another seed shipment resulted, after harvesting a crop, in 25 000 trees being planted by university students and faculty, around laborers’ houses in Maranhao, Brazil. The tree is not limited to tropical lowlands, but thrives at elevations of 800-1200 m in protected mountain areas of southern Mexico. The long-range effects of ingesting various parts of the tree as food or folkmedicine need study. Attention should be given to horticultural improvement, perhaps through hybridization with one or more related species now being compared with M. pterygosperma in India and Africa. ХРеНовое дерево, Moringa pterygosperma F. Gaertn. (Moringaceae), Дар сыхим землям. Хреновое дерево, Moringa pterygosperma, вводится в бездождивые землии чтоб умножить местное снабжение пищи и корма. Дерево растет до 5 метров в год. Листья содержат много кальцию и половину щавелев по сравнени#x044E; с амарантом. Семя дают съедобное масло и семеная мука употребляется как одобрение и как коагулант для очищение мутной воды. Филантропический цэнтэр ECHO (Educational Concern for Hunger Organization, North Fort Myers, Florida) полужает мното просьб чтоб получить семя. Один миссионер из Мали писал “Семя которые вы послали, прибыли в самый сухой год за 14 лет сухой погоды. Только моринга пережила и цвела. Другая отправка семен была совершена после получения урожая и 25000 деревьев были посажены студентами и учителями около домов рабочих в Маранхау, Брразилия. Это дерево не ограаничевается тропическим климатом и преуспевает на уровне 800 до 1200 метров в защищенных горных местах южной Мексики.     

Induction of CD4+ cytotoxic T cells by sensitization with allogeneic melanomas bearing shared or cross-reactive HLA-A.

Human melanoma is an immunogenic neoplasm whereby enhancement of specific cell-mediated immunity can alter tumor progression. HLA-A2-restricted CTL have been demonstrated to kill allogeneic HLA-A2-matched melanoma. We investigated the ability of allogeneic melanoma cells sharing HLA-A antigens to sensitize melanoma patients' lymphocytes to induce HLA-A-restricted CTL to autologous melanoma. PBL from melanoma patients were cocultured with autologous melanoma cells in defined "cocktail medium" to generate melanoma-specific HLA-A-restricted CTL lines. CTL generated by sensitization with allogeneic melanoma bearing shared HLA-A2, A11, A24, or "cross-reactive" HLA-A antigens could kill almost as many autologous melanoma cells as CTL sensitized with autologous melanoma. There are HLA-A antigens that are immunogenically cross-reactive because they share determinant epitopes. CTL were not activated NK or LAK cells. The HLA restriction and melanoma cell specificity of the CTL were demonstrated by cold target inhibition with autologous and allogeneic melanoma and B lymphoblasts. Anti-CD3 and anti-HLA AB inhibited CTL killing of melanoma. The CTL were predominantly CD3+CD4+ TCR alpha/beta+. These studies demonstrate that melanomas being shared or cross-reactive HLA-A can be used for in vitro generation of HLA-restricted CTL that recognize melanoma-associated antigens. The findings have very important implications in human tumor immunotherapy.     

Complete amino acid sequence of tenebrosin-C, a cardiac stimulatory and haemolytic protein from the sea anemone Actinia tenebrosa

The complete amino acid sequence of the cardiac stimulatory and haemolytic protein tenebrosin-C, from the Australian sea anemone Actinia tenebrosa, has been determined by Edman degradation of the intact molecule and fragments produced by treatment of the polypeptide chain with cyanogen bromide and enzymatic cleavage with endoproteinase Asp-N, thermolysin and trypsin. The molecule is a single-chain polypeptide consisting of 179 amino acid residues with a calculated molecular mass of 19,797 Da. Tenebrosin-C shows a high degree of amino acid sequence similarity (63%) with Stoichactis helianthus cytolysin III [Blumenthal, K. M. and Kem, W. R. (1983) J. Biol. Chem. 258, 5574-5581] and is identical to a partial sequence (90 residues) reported for equinatoxin, a cardiostimulatory and haemolytic protein isolated from the European sea anemone Actinia equina [Ferlan, I. and Jackson, K. (1983) Toxicon Suppl. 3, 141-144]. No amino acid sequence similarity was detected between tenebrosin-C and other protein sequences stored in available databases. The predicted secondary structure of tenebrosin-C suggests that it is a compact, highly structured molecule.