Diabetes in pregnancy: effects on the foetal and newborn rat with particular regard to body weight, serum insulin concentration and pancreatic contents of insulin, glucagon and somatostatin

Streptozotocin (SZ) treated virgin female rats, classified as either manifest diabetic (MD) or subdiabetic (SD) according to intraperitoneal glucose tolerance tests, were mated. Normal untreated rats (N) were also mated and used as controls. On gestational day 20 the MD foetuses showed decreased litter sizes, elevated blood glucose values and glucose-to-insulin ratios, decreased body and pancreatic weights and markedly diminished pancreatic insulin contents. The MD pregnancy was prolonged by two days and about 50 per cent of the offspring died perinatally. Both the wet and dry carcass weights of the non-viable MD offspring were increased, but when correction was made for the prolonged gestational period both the viable and non-viable newborns were lighter than those of the other groups. In the viable newborns of MD mothers the blood glucose concentration was elevated and the pancreatic contents of insulin and somatostatin decreased while that of glucagon remained unchanged. The 20-day-old SD foetuses showed increased pancreatic insulin and somatostatin contents but were identical to N foetuses in all other respects. Similarly, the newborns of SD mothers remained indistinguishable from those of the N mothers.

It is concluded that, in the rat, severe SZ-diabetes induced before pregnancy causes foetal growth retardation and decreased pancreatic insulin stores. The observations suggest that excessive hyperglycaemia in the foetus hampers the normal development of the pancreatic B-cell. The absence of macrosomia and hyperinsulinism in both the MD and SD newborns suggests a difference between human and rat foetal development in diabetic pregnancy.

Glucagon biosynthesis in isolated pancreatic islets of mice and guinea pigs

To further investigate the regulation of glucagon biosynthesis in mammalian A2-cells, we have studied the incorporation of [3H]-tryptophan into acid alcohol extracts of isolated pancreatic islets of guinea pig and mouse. Gel chromatography on Sephadex G-50 indicated that labelled proteins, migrating either with the void volume (peak I) or in region (peak II) between the void volume and the insulin marker, were formed during a 6h incubation of the islets. However, a period of at least two days in tissue culture was required before the islets showed any significant accumulation of labelled protein eluting in a position corresponding to that of pancreatic glucagon (peak III). Addition of glucose (16.7 mM) enhanced the incorporation into all chromatograph fractions during the culture period. Binding of gel chromatographed proteins Sepharose coupled anti-glucagon antibodies indicated that both guinea pig and mouse islets contained only small amounts of labelled, immunoreactive proteins eluting with either peak I or peak II. However, proteins eluting with peak III contained 6-8 times more lbelled, immunoreactive material than any of the other peaks. Total glucagon immunoreactivity was abundant in peaks I and II but less evident in peak II. The results of pulse-chase experiments provided no convincing evidence for a precursor-product relationship between larger proteins and glucagon. However, the heterogeneity of the putative precursor pool, as evidenced both by SDS-polyacrylamide gel electrophoresis and by the low immune binding, might have masked a conversion process. The combined data show that glucagon is, indeed, synthesized in isolated islets of guinea-pig and mouse, but that this process occurs slowly.

Aspects of aggression in formerly depressed patients and in healthy controls

Thirty former inpatients (14 male and 16 female) who had suffered from a nonpsychotic depressive syndrome were investigated by means of a new personality inventory--the KSP--when they had recovered from the depressive disorder, and their results were contrasted to those obtained from 53 healthy controls (19 male, 34 female). Attention was focused on the subscales of the KSP which refer to aspects of aggression. Former patients scored significantly higher than controls in the variables 'irritability,' 'suspicion,' 'guilt,' and 'inhibition of aggression.' The findings suggest a particular personality makeup for at least one subgroup of depression-prone subjects and closely resemble classical concepts of hostility and depression.

Nitrogenase from Rhodospirillum rubrum. Relation between 'switch-off' effect and the membrane component. Hydrogen production and acetylene reduction with different nitrogenase component ratios

Nitrogenase activity of 'membrane-free' extracts, produced from nitrogen-starved Rhodospirillum rubrum to which 4 mM NH4+ had been added is only about 10% of the activity in the control. The activity could be restored to 80% by including the membrane component, earlier found to activate R. rubrum nitrogenase, in the reaction mixture. The relation between this 'switch-off/switch-on' effect and the function of the membrane component is discussed. Hydrogen production catalyzed by R. rubrum nitrogenase is also dependent on activation by the membrane component. Hydrogen production is inhibited by acetylene but the degree of inhibition is dependent on the nitrogenase component ratio. The strongest inhibition is achieved at low MoFe protein/Fe protein rations. The ATP/2E- values are 4-5 at the component ratios giving the highest activity and increase at high MoFe protein/Fe protein ratios. CO inhibits acetylene reduction but has no effect on the hydrogen production.

Salmonella phage glycanases: substrate specificity of the phage P22 endo-rhamnosidase

Interaction between phage P22 and phenol-water extracted lipopolysaccharides from sensitive Salmonella bacteria belonging to serogroups A, B and Di results in hydrolysis of the alpha-L-rhamnosyl linkages within the tetrasaccharide repeating unit of the O-antigenic polysaccharide chain. These O-antigens have identical structures except for the nature of the 3,6-dideoxy-hexosyl group linked to O-3 of the D-mannosyl residue. Removal of the dideoxysugar, or periodate oxidation followed by borohydride reduction of the L-rhamnosyl residue made the O chain resistant to the endo-rhamnosidase. Substitution of the D-galactosyl residue at O-4, but not at O-6, with an alpha-D-glucosyl group was compatible with hydrolysis. A number of Klebsiella pneumoniae and Shigella flexneri lipo- or capsular polysaccharides containing chain L-rhamnosyl residues were tested but none was sensitive to the P22 endo-rhamnosidase. The substrate specificity of the endo-rhamnosidase parallels the lytic specificity of the phage which suggests that the initial step in phage P22 infection is a P22 tail enzyme O-antigen substrate interaction. The main product of the hydrolysate was octa-, dodeca- and hexadecasaccharides. Treatment of phage FO resistant smooth strains of S. typhimurium with P22 tails removed O polysaccharide chains and made previously 'hidden' FO receptors accessible to the phage.

Variations in self-assessment of personality characteristics in depressed patients, with special reference to aspects of aggression

30 in-patients, 14 male and 16 female, aged 24-69 years (mean age 47.1 +/- 2.7) suffering from a moderately severe or severe depressive syndrome completed a new personality inventory, the KSP, on two separate occasions. The first-when they were depressed and had just been admitted to the hospital, the second when they were at home and in their customary situation. On the same test occasions the severity of their psychopathology was rated by means of the CPRS. A significant improvement in CPRS rating was ascertained on the second test occasion. In contrast only small changes occurred in the subscales of the KSP. The score referring to 'psychic anxiety' and to 'somatic anxiety' decreased slightly but significantly (p less than 0.05). The scores referring to 'social desirability' also showed a significant (p less than 0.01) slight decrease. Of particular note is that no significant differences were found in the 6 KSP subscales concerned with aspects of aggression, or in the factors which can be obtained from these subscales. Our findings amongst this population of non-psychotic depressed patients do not support the assumption that changes in the direction of aggression occur during depression.

Properties of the nitrogenase system from a photosynthetic bacterium, Rhodospirillum rubrum

Soluble nitrogenase from Rhodospirillum rubrum has been isolated and separated into its two components, the MoFe protein and the Fe protein. The MoFe protein has been purified to near homogeneity and has a molecular weight or 215 000. It contains two Mo, 25--30 Fe and 19--22 acid-labile sulphide and consists of four subunits, Mw 56 000. The Fe protein has a molecular weight 65 000. It contains approximately four Fe and four acid-labile sulphide and consists of two subunits, Mw 31 500. The highest specific activities for the purified components are 920 and 1260 nmol ethylene produced per min per mg protein, respectively. The purified components require the membrane component for activity (Nordlund, S., Eriksson, U. and Baltscheffsky, H. (1977) Biochim. Biophys. Acta 462, 187--195). Titration of the MoFe protein with the Fe protein shows saturation and excess MoFe protein over Fe protein is inhibitory. Addition of Fe2+ or Mn2+ to the reaction mixture increases the activity apparently through interaction with the membrane component.

Necessity of a membrane component for nitrogenase activity in Rhodospirillum rubrum

Acetylene reduction catalyzed by nitrogenase from Rhodospirillum rubrum has low activity and exhibits a lag phase. The activity can be increased by the addition of a chromatophore membrane component and the lag eliminated by preincubation with this component, which can be solubilized from chromatophores by treatment with NaCl. It is both trypsin- and oxygen-sensitive. Titration of the membrane component with nitrogenase and vice versa shows a saturation point. The membrane component interacts specifically with the Fe protein of nitrogenase, the interaction being ATP- and Mg2+-dependent.

Adsorption of phage P22 to Salmonella typhimurium

Adsorption of phage P22 to its receptor in the lipopolysaccharide (LPS) of the envelope of Salmonella typhimurium is accompanied by a hydrolytic cleavage of the O polysaccharide chain. The enzyme, and endorhamnosidase, is found in the phage tail. Propagation of a mutant of phage P22, containing two amber mutations, under restrictive conditions permitted isolation of phage tail parts with endorhamnosidase activity. The tail parts, purified by ion exchange chromatography, were shown to be homogenous by polyacrylamide gradient gel electrophoresis, isoelectric focusing in polyacrylamide gel electrophoresis and crossed immunoelectrophoresis. The mol. wt. was estimated to 240000. The optimal pH range for glycosidase activity was 5 to 7 and optimal temperature 37 degrees C. Hydrolysis of the O polysaccharide chain, when estimated with whole bacteria as the substrate, did not seem to be influenced by the cation concentration. Eclipse of P22 phage particles to whole bacteria was likewise uninfluenced by the cation concentration in the reaction mixture, but eclipse by isolated receptor containing LPS required cations. The optimal concentration for divalent cations was 2 X 10(-3) M, for trivalent cations 1 X 10(-3) M.

Thrombosis following hip arthroplasty. A study using phlebography and 125I-fibrinogen test

Venous thrombosis after hip arthroplasty was studied using the 125I-fibrinogen test and phlebography. Eight out of ten dextran-treated and six out of ten control patients developed thrombosis. The thrombi were small and most frequently dorsal and dorso-lateral veins were involved. There were no thigh thrombi without concurrent calf thrombi. Half of the thrombi were found within the first postoperative week whereas the remainder occurred later. Preoperative venous pathology predisposed to postoperative thrombosis.

Indirect immunofluorescence staining of human thyroid by antibodies occurring in Yersinia enterocolitica infections

In the diagnostic routine for tissue antibodies, using indirect immunofluorescence on cryostat sections of human thyrotoxic thyroid, rat stomach and kidney, ninety-six out of 48,388 sera showed a marginal staining of the membrane region of thyroid epithelial cells but no other reaction. Twenty-six of these sera were from patients with acute Yersinia enterocolitica serotype 3 infection but without signs of thyroid disease. Fifty of sixty-three sera with agglutinins against Y. enterocolitica serotype 3 and three out of four sera with agglutinins against Y. enterocolitica serotype 9 also showed this reaction on thyroid sections. It was due to antibodies, mostly of the IgG class, occurring in low titre, which react with intracytoplasmic antigens in thyroid, as staining of live thyroid epithelial cells was negative. The pattern of immunofluorescence on thyroid sections caused by these antibodies could not be distinguished from that caused by smooth muscle antibodies by appearance only. However, smooth muscle antibodies react also on other tissue sections and extracts of contractile proteins which absorb out these, did not change the reaction on thyroid of Y. enterocolitica sera. Absorption with sonicated Y. enterocolitica 3 and 9 antigens, but not with heat-killed whole bacteria, extinguished the reaction on thyroid. This indicates the presence of a cross-reactivity between antigens in these bacteria, different from the O antigen, and antigens in thyroid epithelial cells. Knowledge of this pattern of immunofluorescence on thyroid sections can be of diagnostic significance.

A NOTE ON THE EFFECT OF SELECTIVE SAMPLING PROCEDURES ON THE PHI COEFFICIENT

A general equadion is presented, covering all arbitrary values for the true population splits, for obtaining the true population phi, given observed cell frequencies for a selected sample, and true population splits. A nongeneral solution is also offered, based on the use of the G Index. Demonstrations with hypothetical data are given.