Birth weight of offspring and mortality in the Renfrew and Paisley study: prospective observational study.

OBJECTIVE: To investigate the association between birth weight of offspring and mortality among fathers and mothers in the west of Scotland. DESIGN: Prospective observational study. PARTICIPANTS: 794 married couples in Renfrew district of the west of Scotland. MAIN OUTCOME MEASURES: Mortality from all causes and from cardiovascular disease over 15 year follow up. RESULTS: Women who had heavier babies were taller, had higher body mass index and better lung function, and were less likely to be smokers than mothers of lighter babies. Fathers of heavier babies were taller and less likely to be smokers than fathers of lighter babies. Mortality was inversely related to offspring''s birth weight for both mothers (relative rate for a 1 kg lower birth weight 1.82 (95% confidence interval 1.23 to 2.70)) and fathers (relative rate 1.35 (1.03 to 1.79)). For mortality from cardiovascular disease, inverse associations were seen for mothers (2.00 (1.18 to 3.33)) and fathers (1.52 (1.03 to 2.17)). Adjustment for blood pressure, plasma cholesterol, body mass index, height, social class, area based deprivation category, smoking, lung function, angina, bronchitis, and electrocardiographic evidence of ischaemia had little effect on these risk estimates, although levels of statistical significance were reduced. CONCLUSIONS: Birth weight of offspring was related inversely to mortality, from all causes and cardiovascular disease, in this cohort. The strength of this association was greater than would have been expected by the degree of concordance of birth weights across generations, but an extensive range of potential confounding factors could not account for the association. Mortality is therefore influenced by a factor related to birth weight that is transmissible across generations.     

Shoot regeneration from mesophyll protoplasts and leaf explants of Rehmannia glutinosa

Mesophyll protoplasts obtained from leaves of shoot cultures of Rehmannia glutinosa were cultured in Murashige and Skoog (1962) liquid or liquid-over-agar medium containing 2.0 mg L^?1 naphthaleneacetic acid and 0.5 mg L^?1 benzylamino purine. An amino acid mixture of glutamine, arginine, glycine, and aspartic acid promoted sustained protoplast division, with an average plating efficiency of 27%. Protoplast-derived colonies formed callus which readily regenerated shoots on fransfer to Murashige and Skoog based agar medium with 2.0 mg L^?1 indoleacetic acid and 1.0 mg L^?1 benzylamino purine. Leaf explants also showed a marked capacity for shoot regeneration in culture.     

Autoradiographic study of protein synthesis in abdominal tissues of Glossina austeni

Protein synthesis at various times during the pregnancy cycle of G. austeni was determined by autoradiographic measurement of the incorporation of H³-leucine and H³-tyrosine into the cells of the fat body, oenocytes, milk gland and epidermis. The rate of utilization of these molecules is such that the labelled pool in the haemolymph is depleted before 0.5 hr after injection. The incorporation of both amino acids into fat body and oenocytes is high at eclosion and just after larviposition, with the incorporation of tyrosine by the oenocytes being much higher than that in the fat body. The same pattern of incorporation is observed in the epidermal cells. Label also appears in the endocuticle during the first 10 days of adult life. Except during the first 4 days following emergence, the incorporation of the two amino acids into the milk gland is very high, with periods of less intense protein synthesis at about the time of larviposition. The milk gland represents a highly efficient secretory system, with a t₅₀ of less than 30 min.     

Spherical bodies in the cytoplasm ofCentaurea cyanus L. (Cornflower) cells

Summary Spherical bodies, 650–750 Å in diameter, are present in undifferentiated callus tissue, and in meristematic and differentiated cells in plants ofCentaurea cyanus L. (Cornflower). Most of these organelles are localised in the cytoplasm immediately external to the nucleus.     

Hydrophobic interaction of human, mouse, and rabbit interferons with immobilized hydrocarbons.

Interferons of human, mouse, and rabbit origin bind to straight chain hydrocarbons immobilized on agarose. The hydrophobic nature of binding is established by the following observations: (a) a positive correlation between the length of hydrocarbon ligand and the strength of interaction; (b) a stronger interaction with hydrocarbon ligands terminated with apolar rather than polar head groups; (c) a lack of dependence of binding on ionic strength and pH of the solvent; (d) a reversal of binding by ethylene glycol, a hydrophobic solute; (e) an increasing eluting efficacy of tetraalkylammonium ions with the length of their alkyl substituents. The hydrophobic interactions of human interferon underlie the efficiency of two-step chromatographic procedures. For example, human embryo kidney interferon can be purified about 3,600-fold by sequential chromatography on (a) concanavalin A-agarose, (b) octyl-agarose. Another two-step procedure: (a) concanavalin A-agarose, (b) L-tryptophan-agarose, gives about 10,000-fold purification. The overall recovery of interferon in both cases in close to 90%.     

Selective uptake of noradrenaline,dopa, and 5-Hydroxytryptamine by the nervous system of Phocanema decipiens (Nematoda): A light autoradiographic and ultrastructural study

As determined by light microscopic autoradiography, parts of the nervous system of Phocanema decipiens have selective and high affinity mechanisms for the uptake of tritiated noradrenaline, dihydroxyphenylalanine (dopa) and 5-hydroxytryptamine. In the nervous system, noradrenaline is accumulated only by the four papillary nerves and two fibers in the nerve ring. The precursor dopa is also taken up by these neurons and, in addition, by the lateral nerves. 5-Hydroxytryptamine is accumulated by the three pharyngeal nerves, two cells in each lateral ganglion, and two other fibers in the nerve ring. With adjacent ultrathin sections, the labelled papillary nerve and lateral ganglion were examined ultrastructurally and found to contain various dense core vesicles which are similar to those in other aminergic neurons. The adjoining unlabelled cells of the same neurons are found, on the other hand, to contain dense agranular vesicles. With these results, the noradrenaline accumulating neurons are suggested to be noradrenergic and to contain the amine synthesizing enzymes. The lateral nerves are regarded, for the present, as dopaminergic neurons. These suggestions are in agreement with the previous demonstration of catecholaminergic neurons in this nematode. The 5-hydroxytryptamine accumulating neurons are tentatively identified as tryptaminergic.     

Nonsymbiotic nitrogen-fixing micro-organisms in forest and tundra soils

Summary Soil samples obtained from various forested sites in North Carolina and Washington and from Alaskan tundra were examined for the presence of heterotrophic, nonsymbiotic nitrogen-fixing micro-organisms. Aerobic, nitrogen-fixing micro-organisms were not isolated from any of the soils examined. Estimates of anaerobic nitrogen-fixing bacteria in these soils ranged from 50,000 to 2,000,000/g when a dilution plate technique and a medium supplemented with potato extract was used. However, the isolation of individual colonies from the dilution plates showed that many of these bacteria were unable to fix nitrogen. Soil populations well below 100,000/g were generally indicated by this colony isolation technique. Differentiation of the colonies by size improved the accuracy of the dilution plate estimates somewhat. Dilution tube procedures appeared more suitable for obtaining accurate counts of nitrogen-fixing anaerobes in the soil than the use of dilution plates. The predominant nitrogen-fixing bacterium in most soils was a facultative anaerobe,Bacillus polymyxa. Appreciable numbers of nitrogen-fixing clostridia were also found in several tree nursery soils but were seldom isolated from forest and tundra samples. The clostridia isolated were classified asClostridium butyricum andC. pasteurianum. Variations in the fermentation patterns of these bacteria occurred when the nitrogen supply of the medium was altered. TheC. butyricum isolates were all from forest soils while all except one of theC. pasteuranium isolates were from tundra soils. Paper number2998 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh, N.C     

Close-packing of plasma membrane particles during wall regeneration by isolated higher plant protoplasts—fact or artefact?

Summary Freeze-fracture preparations of protoplasts isolated from cell suspension cultures and leaf mesophyll tissue have been examined by transmission electron microscopy. During the first 72 hours of cell wall regeneration, the 8–10nm intramembraneous particles were randomly distributed on both the protoplasmic and extracellular fracture faces of the plasma membranes of protoplasts frozen and fractured in the culture medium without glutaraldehyde fixation or cryoprotection. Incubation of living protoplasts in culture medium containing 20% v/v glycerol as cryoprotectant prior to freezing without fixation caused deformation of the plasma membrane in the form of protrusions accompanied by particle aggregation on the protoplasmic fracture face of the membrane. Intramembraneous particle aggregation was not observed in protoplasts fixed in glutaraldehyde prior to incubation in medium containing glycerol. The aggregation of particles into hexagonal close packed arrays and elongate chains is discussed in relation to a previous report in the literature of the possible involvement of intramembraneous particle complexes in microfibril formation by isolated higher plant protoplasts.     

Hydrophobic binding sites on human interferon.

Human interferon binds to a omega-carboxpentyl-agarose column at low ionic strength (0.15 M NaCl) and is still retained when the ionic strength is raised (to 1.0 M NaCl). The binding can be reversed, however, by ethylene glycol, indicating a hydrophobic interaction. The binding of human interferon to omega-aminohexyl-agarose is weak, even at a low ionic strength, and is probably exclusively electrostatic. This disparate binding behavior may be caused by the presence of a positive charge, adjacent to the hydrophobic binding site, on human interferon. The interaction of human interferon with omega-carboxypentyl-agarose is quite selective, inasmuch as the majority of proteins present in interferon preparations pass through the column unretained. Hydrophobic chromatography of human interferon may thus be useful in its purification.     

Molecular structure of human fibroblast and leukocyte interferons: probe by lectin and hydrophobic chromatography.

Structural differences between human leukocyte virus-induced interferon and human fibroblast polyinosinic-polycytidylic acid (rIn-rCn)-induced interferon have been noted in previous studies. This study reports the behavior of human leukocyte and fibroblast interferon, induced by virus and by rIn-rCn, in several lectin and hydrophobic chromatographic systems. Differences in both glycosylation and in hydrophobicity of human leukocyte and fibroblast interferons are documented. Human fibroblast interferon is a glycoprotein, whereas our evidence suggests that human leukocyte interferon probably is not. Also, fibroblast interferon is more hydrophobic than leukocyte interferon, as probed on several hydrophobic adsorbents. The possible relationships of these differences to each other and to antigenic variations are discussed. Generally, the differences appear to be attributable to the cell type in which the interferon was induced. However, our results suggest that at least subtle differences in the processing of the induction signal (virus or rIn-rCn) within the same cell type may occur, slightly altering some structural features.