Dietary sucrose affects plasma HDL cholesterol concentration in young men

Fourteen young male volunteers measured their habitual dietary intake for 2 weeks, then were told to increase their dietary sucrose while decreasing their other carbohydrates for 2 weeks and finally told to revert to their habitual diet while continuing to record their intake. Measurement of plasma constituents revealed a significant fall in HDL-cholesterol concentration after the period on the high sucrose diet, and a return to the higher concentrations after resumption of the habitual diet. Twenty-six young men whose habitual diet contained more than an average quantity of sucrose followed a similar regime, except that they were told to reduce their sucrose for 2 weeks and to compensate by increasing the intake of other carbohydrates. In the event, unlike the volunteers in the first experiment, they were found not to have made the compensatory change when lowering their sucrose intake. Measurement of their plasma constituents showed that the reduction in dietary sucrose resulted in a significant fall in the mean concentration of triglycerides. There was no significant change in the mean concentration of HDL cholesterol, although there was an increase in the concentration in 11 of the 26 subjects.

Cycloetherification of hydroxyoleanenes by N-bromosuccinimide

Treatment of 28-hydroxyolean-12-enes with N-bromosuccinimide (NBS) in acetonitrile at room temperature afforded 12 alpha-bromooleanan-13beta, 28-epoxides in high yield. This reaction resulted in the formation of olean-9 (11), 12-diene-18alpha, 29-epoxides from 29-hydroxy isomers but recovered only starting materials from 30-hydroxy isomers. NBS will be used a reagent for diagnostic tool to distinguish between isomers bearing a primary hydroxyl group on D/E rings of olean-12-enes.

Studies on Aristolochia III. Isolation and biological evaluation of constituents of Aristolochia indica roots for fertility-regulating activity

An ethanol extract of Aristolochia indica roots decreased fertility in both rats and hamsters when administered postcoitally (days 1-10 and 1-6, respectively). Petroleum ether (A), CHCl3 (B), and aqueous (C) fractions, tested similarly in rats, were inactive and/or toxic. Partition of fraction B afforded non-acidic (D) and acidic (E) fractions. Savinin (1), isolated from fraction D and not previously reported from the Aristolochiaceae , was inactive when administered postcoitally to rats. Aristolochic acid-I (2), reported previously from A. indica and isolated from fraction E, was inactive when administered postcoitally to rats and toxic when administered postcoitally to hamsters. (12S)-7,12- Secoishwaran -12-ol (3), previously reported from A. indica and isolated from fraction A, did not interrupt pregnancy when administered to mice on day 6 of pregnancy. Four additional compounds, aristolic acid (4) [prepared from aristolochic acid-I (2)], methyl aristolate (5) [prepared by methylating aristolic acid (4)], and cis- and trans-p-coumaric acid (both oblate commercially), were similarly tested in mice and found to be inactive. Aristolic acid (4), and the cis- and trans-p-coumaric acids also were inactive when administered postcoitally (days 1-10) to rats. Seven compounds reported previously from A. indica were also isolated, as were a new naphthoquinone, aristolindiquinone (6) (fraction E), and magnoflorine (fraction C).

Cytotoxic effect of anti-idiotype antibody-chlorambucil conjugates against human lymphoblastoid cells

The secreted IgMs of two human lymphoblastoid cell lines, RPMI-6410 and RPMI-8392, were purified. Antisera against these two IgMs were raised in rabbits and made idiotypically specific to the respective antigens through various absorption procedures. By immunofluorescence and radioimmunoassay techniques, the purified anti-idiotype antibodies were found to react also with the membrane Igs of the respective cell lines, but not with those of other cell lines. The purified anti-idiotype antibodies were then coupled with Chlorambucil to form antibody-drug conjugates, whose effectiveness in the in-vitro killing of target cells was evaluated by a chromium-release cytotoxicity assay. The results showed that these anti-idiotype antibody-Chlorambucil conjugates were specifically cytotoxic to lymphoblastoid cells that bore membrane Igs carrying the respective idiotypic determinant(s). Furthermore, the conjugates were far more effective in causing cytolysis to the target cells than either Chlorambucil or the anti-idiotype antibodies alone.

Effects of alpha-adrenoceptor antagonists administered intraventricularly on central hypotensive action of clonidine and on central hypertensive action of methoxamine in rabbits

In urethane-anesthetized rabbits blood pressure was lowered by intraventricular clonidine (30 microgram) and increased by intraventricular methoxamine (1 mg). Clonidine is well known to cause hypotension by acting on central alpha-adrenoceptors. The hypertensive effect of intraventricular methoxamine was not observed in cord-sectioned rabbits, in guanethidine-treated adrenalectomized rabbits and in phentolamine-treated rabbits, indicating the effect was central in origin. These responses to intraventricularly administered clonidine and methoxamine were examined in rabbits pretreated intraventricularly with various alpha-adrenoceptor antagonists believed to exhibit preference for alpha 1- or alpha 2-adrenoceptors in the peripheral tissues. Pretreatment with 250 microgram of yohimbine and with 500 microgram of piperoxan inhibited the clonidine hypotension, but pretreatment even with 2 mg of either of these drugs did not affect the methoxamine hypertension. In contrast, pretreatment with 8 microgram of prazosin inhibited the methoxamine effect, whereas pretreatment even with 1 mg of prazosin did not affect the clonidine effect. Pretreatment with 8 microgram of thymoxamine inhibited the methoxamine effect, while it was necessary to increase the doses for each drug up to 4 to 8 times to oppose the clonidine effect. Pretreatment with 2 mg of labetalol inhibited the methoxamine effect but was ineffective against clonidine. Pretreatment with 500 microgram of phentolamine was effective in antagonizing the clonidine effect but twice the dose was needed to inhibit the methoxamine effect. From the findings that the hypertensive effect of methoxamine and the hypotensive effect of clonidine were inhibited differently by various alpha-adrenoceptor antagonists and that the selectivity of these antagonists for the methoxamine and clonidine effect is similar, respectively, to that for alpha 1- and alpha 2-adrenoceptors in the peripheral tissues, we concluded that the methoxamine hypertension and the clonidine hypotension are due to the stimulation of alpha 1- and alpha 2- adrenoceptors in the brain, respectively.

The effect of D-penicillamine on protein-bound homocyst(e)ine in homocystinurics

There is considerable evidence that homocystine has a direct damaging effect on vascular endothelium and other tissues. The demonstration of the existence of protein-bound homocyst(e)ine has strengthened this hypothesis. In an attempt to remove bound homocyst(e)ine, D-penicillamine was given to three patients with pyridoxine-nonresponsive homocystinuria. Before the clinical trial, it had been demonstrated that 0.1 mumole per ml concentration of D-penicillamine or cysteamine released approximately 50% of the homocyst(e)ine bound to plasma proteins in vitro. Oral D-penicillamine effectively reduced both free and plasma protein-bound homocyst(e)ine in homocystinurics from the second day of treatment. The homocystine excreted in the urine was mainly in the form of homocysteine-penicillamine disulfide. No mixed disulfide was detectable in the plasma, indicating an extremely high renal clearance. These observations suggested that oral D-penicillamine removed a considerable quantity of the bound homocyst(e)ine accumulated in the tissue proteins.

Changes in metabolism of rat kidney and liver caused by experimental diabetes and by dietary sucrose

Two groups of rats were fed diets in which the carbohydrate components was either starch or sucrose. A third group was fed on a stock diet. Half of the animals in each group were made diabetic by injection of either streptozotocin, in two of the groups, or alloxan, in the third group. Both diabetes and sucrose-feeding increased renal gluconeogenesis as indicated by increased activities of fructose-1,6-diphosphatase and glucose-6-phosphatase. Sucrose-feeding increased fatty acid synthesis both in the liver and kidney. However, the effect of diabetes on fatty acid synthesis was different at the two tissue sites. Diabetes, whether induced by streptozotocin or alloxan, decreased fatty acid synthesis in the liver but increased the rate in the kidney. The latter response was obtained for each diet but was additive with the effect of sucrose. We conclude that the effect of diabetes on renal lipid metabolism may reflect, in part, the accelerated glucose flux. The response to both diabetes and sucrose-feeding is also possibly associated with the increased lipid required for the membrane synthesis reported previously.

Modification of the glomerular basement membrane in sucrose-fed and streptozotocin-diabetic rats

Rats were fed on diets containing either sucrose or starch as the carbohydrate component (55%) for eight months. Diabetes was induced in animals of both groups by injecting streptozotocin (50 mg/kg body weight). Diabetic rats failed to gain weight, had enlarged kidneys, polyuria and elevated blood glucose levels. Starch and sucrose fed rats gained weight normally and had normal blood glucose levels. Sucrose fed rats had enlarged kidneys. Regional thickening of the glomerular basement membrane was present in sucrose-fed and diabetic rats but not in starch-fed controls. Glomerular basement membrane isolated from pooled kidney cortices from rats in the different experimental groups were analysed for amino acid, disaccharide and hexosamine content. Hydroxylysine (9 to 20%), hydroxyproline (21 to 24%), disaccharide (27%) and hexosamine (26%) were increased in membranes insolated from the three experimental groups, compared with starch-fed non-diabetic controls. An increase in low molecular weight components of the glomerular basement membrane of sucrose-fed and diabetic rats was observed using electrophoresis in sodium dodecyl sulphate. Significantly higher (p < 0.001) glucosyltransferase activity was present in kidney supernatants prepared from sucrose-fed (1050 +/- 60 nmol/2h/kidney) compared to starch-fed rats (510 +/- 40 nmol/2h/kidney). Sucrose feeding induces changes similar to those found in diabetes and the induction of diabetes made little difference over the feeding of sucrose alone.

[Intracranial malignant lymphoma (author's transl)]

We experienced 19 histologically verified intracranial malignant lymphomas during the period of 15 years from April 1, 1965 to August 31, 1979. From the analysis of cases of our own and from the literature, the following are considered to be the clinical characteristics of intracranial malignant lymphomas. 1) Males were more affected than females. 2) The highest frequency was observed in the 5th to 7th decades. 3) Increased intracranial pressure, motor disturbance, and psychic or consciouness disturbance were 3 cardinal symptoms. 4) Tumors were localized frequently in the paraventricular region. 5) Angiography revealed hypovascular lesion in many cases, while CT scan showed homogenous, slightly high density lesion which was remarkably enhanced by contrast material. 6) Long survival was rare irrespective of all kinds of treatments. 7) Immunological classification was thought to be useful in prospecting survival time.

Composition and biosynthesis of glomerular basement membrane in rats fed diets rich in sucrose

1-month-old Sprague-Dawley rats were fed synthetic diets containing 55% sucrose (SU) or starch (ST) as the sole source of carbohydrate for 2, 3 or 8 months. Both the ST and SU fed rats gained weight normally, but SU fed rats had enlarged kidneys. A higher yield of glomerular basement membrane (GBM) was recovered from 9-month-old SU rats. An increase in the hydroxylated amino acid content was found in GBM prepared from SU fed rats and the glycine content was also higher. The increase in the hydroxylation of lysine was accompanied by increased glycosylation and there was 30% more Glc-Gal-Hyl present in GBM from 9-month-old SU rats. GBM was solubilised with sodium dodecyl sulphate (SDS) and 2-mercaptoethanol and subjected to electrophoresis on 5% polyacrylamide gels. There was an apparent fall in the intensity of the bands with molecular weights greater than 200,000 and a concomitant rise in low molecular weight components (50,000-100,000) in GBM from 4-month-old SU rats. These differences between ST and SU membrane were accentuated when the membranes from 9-month-old rats were compared. No significant differences were found in the glucosyl transferase activities of renal cortical homogenates prepared from 3-month-old SU and ST rats, but the activities in SU rats were significantly higher at 4 and 9 months. The feeding of SU-rich diets to rats induces a number of biochemical changes in the kidney which are similar to those found in diabetes. The feeding of SU diets provides a useful animal model with which to study the effect of dietary carbohydrate on renal GBM. SU should not be included in diets fed to diabetic rats because of the similarity of some of its effects and those seen in chemically induced diabetes.

Protein-bound homocyst(e)ine in normal subjects and in patients with homocystinuria

A method was developed to quantitate protein-bound homocyst(e)ine using 2-mercaptoethanol. Protein-bound homocyst(e)ine was discovered in the plasma from normal individuals, ranging from 0.5--2.2 nmole/ml. In two obligatory heterozygotes for classical homocystinuria, plasma protein-bound homocyt(e)ine was 3.5 and 4.8 nmole/ml, respectively. Untreated homozygotes showed approximately a 40-fold increase of plasma protein-bound homocyst(e)ine. Furthermore, using conventional methods, no free homocystine was detectable in the supernatant of plasma precipitate from two classical homocystinuric patients treated with pyridoxine, but plasma protein-bound homocyst(e)ine showed a 10-fold increase. Protein-bound homocyst(e)ine was also demonstrated in the liver, kidney, and brain tissues from a patient with methylenetetrahydrofolate reductase deficiency.

Influence of different dietary carbohydrates on liver and plasma constituents in rats adapted to meal feeding

Male Sprague-Dawley rats were given in one experiment diets with starch or sucrose and in a second experiment diets with glucose or fructose. In each experiment, one group of 5 rats was fed ad libitum and five other groups fed a 3-hour meal each day. After 36 days, one group of the meal-fed rats was killed when the meal was due, and the other groups at intervals after the beginning of the meal. The group fed ad libitum was killed the next day after 21 h fasting. Meal feeding led to a smaller food intake and a smaller gain in weight, and a lower blood concentration of triacylglycerol. The diets with sucrose or fructose produced heavier livers and kidneys than did those with starch or glucose. The consumption of the meal led also to a temporary increase in the weight of the liver. The weight of the kidney, however, did not change in rats given starch or gluocse, but fell in rats given sucrose or fructose. Meal consumption was also followed by an increase in the concentration of liver glycogen, irrespective of the nature of the dietary carbohydrate. The concentration of plasma fatty acids was affected differently by meals containing the different carbohydrates, the extremes being a continuing fall with starch and no change with fructose. The concentration of triacyglycerol was increased by sucrose or fructose after the presentation of the meal. The concentration of blood glucose rose and then fell when the meal contained starch or glucose, but fell and then rose when it contained sucrose, and especially when it contained fructose. The concentration of insulin in meal-fed rats receiving sucrose was higher than that of rats receiving starch, both before and after the meal. This difference was not seen in rats fed ad libitum. The results indicate that the effects of meal feeding, or of sucrose or fructose, are not additive.

The influence of dietary carbohydrate and fat on kidney calcification and the urinary excretion of N-acetyl-beta-glucosaminidase (EC 3.2.1.30)

1. Male Sprague-Dawley rats were fed on diets containing either sucrose or starch as the carbohydrate component. In one experiment, the diets also contained 200 g either butter or polyunsaturated margarine/kg; in a second experiment, the diets contained less fat in the form of 20 g maize oil/kg.

2. Over a period of 11 months assays were made in the urine of several ions and of the activity of the enzymeN-acetyl-β-glucosaminidase (β-2-acetamido-2-deoxy-β-D glucoside acetamidodeoxygluco-hydrolase;EC3.2.1.30); at 13 months, examination was made of some of the abdominal viscera, especially of the kidneys.

3. In rats fed on the higher amount of fat, dietary sucrose produced a higher activity of the enzyme than did dietary starch, and a greater excretion of inorganic phosphate.

4. With both the higher and lower amounts of dietary fat, sucrose led to an increase in the weight of the liver and of the kidneys, and an increase in the concentration of calcium and of phosphate in kidney tissue. With the higher amount of fat, sucrose also produced an increase in the concentration of magnesium in the kidney. There was no difference in the concentration of any of the ions assayed in the plasma or, apart from inorganic phosphate, in the urine.

5. The kidneys of the sucrose-fed rats showed nephrocalcinosis, mostly in the cortico-medullary region, and basophilic deposits in the tubules. Attention is drawn to this unusual occurrence of nephrocalcinosis in male rats.

The effects of dietary sucrose and streptozotocin-diabetes on blood and liver constituents

The levels of ATP, ADP, AMP, inorganic phosphate and 2,3-DPG have been determined in blood and liver of normal and streptozotocin-diabetic rats maintained for up to 11 months on a diet in which the sole carbohydrate source was either starch or sucrose. The feeding of sucrose to normal rats did not significantly alter the adenine nucleotide or phosphate content of the liver and blood. The diabetic state caused a reduction in the ATP, and an increase in AMP and phosphate content of the liver. The feeding of sucrose to the diabetic animals increased the blood phosphate level. The erythrocyte 2,3-DPG content was unaffected by the alterations of ATP and phosphate levels or by the diabetes.

The development of retinopathy in sucrose-fed and streptozotocin-diabetic rats

Normal and streptozotocin-diabetic rats have been maintained for 6--11 months on completely balanced, reconstituted diets in which the sole source of carbohydrate was either 68% corn starch or 68% sucrose. The retinal vascular system was isolated by trypsin digestion and examined histologically for the presence of tortuosity and irregularity of capillary diameter, increased PAS-positive deposits, microaneurysms, loss of pericytes, endothelial proliferation, acellularity and strand formation. None of these pathological changes occurred in normal rats fed a starch-rich diet, but all developed to a similar extent in the sucrose-fed normal rats and the starch-fed diabetic group. The changes were more severe in sucrose-fed diabetic rats after 6 months. In all groups the retinopathy progressed with time. The possibility that a factor common to both the ingestion of a sucrose-rich diet and streptozotocin diabetes in rats has been considered since, histologically, the retinopathy observed was identical both with respect to severity and rate of development in normoglycaemia, sucrose-fed and hyperglycaemia, starch-fed diabetic rats.

Suppression of spectinomycin resistance in a mutant of Escherichia coli K-12

A mutant of Escherichia coli has been isolated which exhibits partial suppression of spectinomycin resistance. The site of mutation is in the streptomycin (strA) region and is closely linked to the spcA gene. However, this gene, which we propose to call mod, is phenotypically distinguishable from both the neomycin-kanamycin (nek) and the ribosomal ambiguity gene (ram). The relative gene order is mod spcA strA. In a cell-free protein synthesizing system, altered ribosomes appear to be responsible for the suppression of spectinomycin resistance caused by mod.

Glucose, glucose-6-phosphate, lactate and pyruvate content of the retina, blood and liver of streptozotocin-diabetic rats fed sucrose- or starch-rich diets

The feeding of starch- or sucrose-rich diets to normal rats for 20 days resulted in a significant increase in lactate level and L/P ratio in the retina in the sucrose-fed animals. There was no correlation between the glucose and lactate content of the blood and retina and it was concluded that the increased lactate content of the retina was derived from the fructose moiety of the sucrose. Liver hypertrophy occurred in both normal and diabetic animals fed the sucrose diet. When streptozotocin-diabetic rats were maintained for 20 days on the same diets significant increases in the lactic acid content of the blood and liver occurred, but the high level of lactate in the retina of the sucrose-fed normal rats was not further elevated. The feeding of sucrose to diabetic rats resulted in better metabolic control of both blood glucose and lactate as compared with the maintenance of these animals on a starch diet.

A mutant of Escherichia coli with temperature-sensitive streptomycin protein

The temperature-sensitive mutation in our Escherichia coli strain C1714 appears to be in a ribosomal protein. The mutation maps at the streptomycin locus. Protein synthesis in intact cells stops immediately when the temperature is shifted from 30 to 42 degrees C. Analysis of polyribosome distributions after shift-up suggests that initiation of protein synthesis is defective at the high temperature. In vitro protein synthesis in extracts from C1714 is temperature sensitive when directed by natural mRNA, but not when directed by poly U.