3-O-Methyl galactose found in polysaccharides of Lampteromyces japonicus

A polysaccharide fraction from Lampteromyces japonicus contained a sugar (4%), which was identified as 3-O-methyl galactose by demethylation with boron trichloride, periodate oxidation of the methyl glycoside derivative and gas chromatography-mass spectrometry of the alditol acetate derivative.

Circles in spermatocyte chromatin loops. Electron microscopy and AgAs-NORs studies

We describe the production of circles in chromomeric loops during the pachytene stage of the spermatocytes. These circles are found attached to chromatin or already free in the nucleoplasm. Each circle measures an average of 3700 A in circunference. We suggest that such circles might indicate the presence of tandem repetitions.

Purification and chemical characterization of polysaccharides obtained from Lampteromyces japonicus by concanavalin A-sepharose affinity chromatography

Two classes of neutral polysaccharide which could not be separated from each other by conventional methods were isolated from the fungus, Lampteromyces japonicus, by affinity chromatography using concanavalin A-Sepharose. The polysaccharide retained on the concanavalin A-Sepharose column was eluted with 0.05 M methyl alpha-D-mannopyranoside and appeared to be alpha-mannan, while that which passed through the column was virtually all beta-glucan. Both polysaccharides were subjected to Smith-type degradation, methylation, acetolysis and glucosidase treatment. The results indicated that the alpha-mannan contained predominantly alpha-(1 leads to 2)-linked side chains branching from an alpha-(1 leads to 6)-linked backbone at the (1 leads to 2,6)-linked mannopyranosyl residues. Galactose was attached to approximately one-quarter of the non-reducing mannose terminals. The beta-glucan seemed to contain mainly (1 leads to 6)-linked side chains branching from a (1 leads to 3)-linked backbone at the (1 leads to 3,6)-linked glucopyranosyl residues.

Pregnancy and delivery in penicillamine treated patients with Wilson's disease

Pregnancy and delivery of two patients with Wilson's disease are reported. Case 1 was a 20-year-old housewife who had been taking D-penicillamine fore more than 10 years and had remained asymptomatic except an episode of dissociative reaction. She apparently survived longer than any of her three sisters who died of the same disease. She discontinued the use of D-penicillamine by herself when she was at the 22nd week of pregnancy. Case 2 was a 32-year-old housewife who developed an episode of mental disorder of short circuit reaction type with mild neurological symptoms and Kayser-Fleischer rings after the prolonged interval of medication since the first pregnancy and delivery. Three months after the complete recovery of neuropsychiatric symptoms she was at the 12th week of pregnancy and withheld penicillamine from herself. During the pregnancy they had not revealed any exacerbation in terms of clinical and laboratory findings. Each of them was delivered of a healthy baby. Although the pregnancy and delivery of both patients were successful, the authors recommended that they should not prolong the interval of medication to protect themselves against the onset or relapse of the illness.

Chromatin ultrastructure of lower vertebrates

Meiotic and mitotic chromosomes from amphibians and snakes were studied by electron microscopy. By using water spreading, preceded by a mild NaCl pretreatment, we showed: 1. 'Beads on a string' arrangement of the chromatin fibres; 2. The presence of loops at pachytene chromomeres as well as during metaphase of both mitosis and first meiosis; 3. Transcriptional activity for non-ribosomal RNA on peripheral loops during the middle pachytene.

A study of the native-denatured (N in equilibrium with D) transition in lysozyme. II. Kinetic analysis of protease digestion

Kinetic analyses of the protease digestion of several chemical derivatives of lysozyme [EC 3.2.1.17] showed that only the D(denatured) state of the protein is digested and that the reaction velocity is proportional to the equilibrium constant (KD) of the N in equilibrium with D transition of the protein. Alteration of the net charge of lysozyme by acetylation caused a shift of the N in equilibrium with D transition to the right (ten-fold increase in KD compared to that of native enzyme). Both the formation of a lysozyme-inhibitor complex and the introduction of a covalent bond in the lysozyme molecule restricted the transition. The magnitude of the N in equilibrium with D transition is related to the susceptibility of lysozyme to protease digestion and it is estimated that the N in equilibrium with D transition in proteins is generally important in the intracellular catabolism of proteins.

Six years of experience with retrograde biopsy of intraureteral carcinoma using the Dormia stone basket

To confirm the cause of a small defect of the ureter and to determine preoperatively the histological grade of ureteral carcinoma a new technique of intraureteral biopsy was attempted with a Dormia stone basket. Of 8 biopsies performed on 7 patients with ureteral or pelvioureteral carcinoma only 1 failed to produce a fragment of tissue. Histological diagnosis was made in each of the 7 patients and histological grading in 5. Four patients with non-malignant defects of the lower ureter also were biopsied with this technique to ascertain the feasibility of this biopsy on minimal filling defects. In each patient a tiny piece of tissue was removed. Histological diagnosis could be made in 3 cases.

Metallic mercury induced tremor in rabbits and mercury content of the central nervous system

Fukuda, K. (1971).Brit. J. industr. Med.,28, 308-311. Metallic mercury induced tremor in rabbits and mercury content of the central nervous system. Tremor induced by metallic mercury was experimentally produced in rabbits by intermittent exposure to mercury vapour (average concentration of 4·0 mg/m³ for 6 hr/day on 4 days/week for 13 successive weeks). Two of six male rabbits exposed developed fine tremor and clonus in the fore- and hind-legs after 13 weeks' exposure. Electromyographic records showed typical grouped voltages accompanying the clonus (amplitude 0·3 to 1·0 mV, duration 20 to 30 ms, frequency 14 to 15 per second). Activation analysis of the central nervous system showed mercury levels ranging from 0·8 to 3·9 μg/g wet tissue. The concentration in the cerebellum, the tegmentum, and the thalamus was significantly higher than in the remaining structures. The relationship between the tremor and the mercury content of the central nervous system is discussed and a positive causal relationship is suggested.