Effect of a spider toxin (JSTX) on excitatory postsynaptic current at neuromuscular synapse of spiny lobster

1. We studied the blocking properties of a spider (Nephila clavata) toxin (JSTX) purified from venom on the spiny lobster neuromuscular junction. 2. When a small amount of JSTX was applied to the neuromuscular junction, the excitatory postsynaptic potential (EPSP) was partially suppressed. The amplitude of EPSPs remained at a steady level for several hours during the washing of the preparation, showing that the action of JSTX is irreversible. 3. We recorded the excitatory postsynaptic current (EPSC) from synaptic site using a macro-patch electrode. The amplitude of EPSC increased linearly with hyperpolarization of the membrane potential in the presence and absence of JSTX. 4. The decay phase time constant of EPSC and spontaneous EPSC was decreased by hyperpolarizing the membrane potential both in the absence and in the presence of JSTX. The relationship between the decay time constant and the membrane potential was not modified by JSTX. 5. It is suggested that JSTX irreversibly blocks EPSC by acting on the site that is apart from the ionic channel of the glutamate receptor molecule.     

Numerous mast cells in an 11-deoxycorticosterone-producing adrenocortical tumor. Histologic evaluation of benignancy and comparison with mast cell distribution in adrenal glands and neoplastic counterparts of 67 surgical specimens

Pathologic study of a rare 11-deoxycorticosterone-producing adrenocortical tumor causing primary aldosteronismlike signs and symptoms, revealed several characteristic features as follows: (1) fairly large size with histologic features corresponding to those of benign zone glomerulosa-type aldosteronoma, (2) lack of spironolactone (S) bodies despite S administration, and (3) heavy mast cell infiltration. In order to explain this rare histology, the localization of mast cells in the adrenal glands and functioning adrenocortical tumors of 67 surgical specimens were investigated. The results of the study supported the view that detection of mast cells helps in the differentiation of mineralocorticoid-producing tumors from cortisol-producing ones, and that the observed mast cell infiltration was due, in part, to its production of 11-deoxycorticosterone.     

ROUTINE LOW AND HIGH RESOLUTION TYPING OF THE HLA-DRB GENE USING THE PCR-MPH (MICROTITRE PLATE HYBRIDIZATION) METHOD

We describe HLA-DRB1 typing using polymerase chain reaction-based microtitre plate hybridization (PCR-MPH), which can process large numbers of samples. MPH typing is similar to an enzyme-linked immunosorbent assay (ELISA), in which a tandemly ligated sequence-specific oligonucleotide is immobilized on microtitre wells. The typing procedure consisted of two steps. In the first, PCR-MPH with 16 probes was performed to determine the specificities of the serological levels (DR1, DR2, DR3, DR4, DR11, DR12, DR13, DR14, DR7, DR8, DR9 and DR10) after generic amplification (‘low resolution typing’). In the second step, DR1, DR2, DR4, DR 12/8 and DR3/11/13/14 were group-specifically amplified based on the results of the first PCR-MPH, and microtitre plate hybridization proceeded in a similar manner to the first step (‘high resolution typing’). Low resolution typing was completed within 2 h after generic amplification, and the results of high resolution typing were obtained in another 3.5 h after amplification. The allelic types classified using PCR-MPH were completely concordant with those obtained by PCR- single-strand conformation polymorphism or PCR-restriction fragment length polymorphism.     

Production of antiserum against antitumor protein-bound polysaccharide preparation, PSK (Krestin) and its pharmacological application

Antiserum against a protein-bound polysaccharide preparation (PSK) was produced by immunizing New Zealand White rabbits with PSK. The intestinal absorption of PSK in mice was visualized by indirect immunofluorescent staining with anti-PSK serum. The change in blood levels of 14C after oral administration of 14C-PSK and the recovery of 14C by antiserum were determined. The results indicated that antigenic epitopes in PSK are not completely destroyed during the process of digestion, absorption and distribution, but the changes of serum levels of 14C radioactivity differ from those of immunoreactive radioactivity. These results suggest that multiple processes are involved in the fate of PSK administered orally.     

Non-functioning adrenocortical adenoma in culture. Quantitative and morphological observations

This report describes the morphological responses of unstimulated and stimulated non-functioning adrenocortical adenoma in culture. The removed adrenocortical adenoma was composed mainly of clear-type cells and partially had a small area of cholesterol granuloma. These adenoma cells had many lipid droplets and round to long rod-shaped mitochondria with tubular or tubulo-lamellar cristae which were similar to those in Cushing's adenoma. The non-functioning adrenocortical adenoma cells which were incubated in vitro under ACTH (10 mIU/ml) and angiotensin II (10(-6) M/ml) stimulation, were examined by phase contrast microscopy, transmission and scanning electron microscopy, and the content of cortisol and aldosterone in the culture medium was measured by radioimmunoassay. As a result of exposure of ACTH, the cultured cells revealed the retraction response and production of cortisol and aldosterone. After administration of ACTH for many days, the cultured cells showed characteristic changes in sER and mitochondria. The sER were markedly developed and packed tightly into a network of dilated tubules. Mitochondria were larger and more numerous than in the unstimulated cells. The mitochondria appeared to be entwined by the tubules of the sER. Lipid droplets decreased in number.     

Association and crystallization of poly(ethylene oxide)

The discontinuous change of the lamellar thickness with crystallization temperature was studied for low molecular weight fractions of OH-terminated poly(ethylene oxide) (PEO). IR analyses demonstrated that almost all of the molecular chain ends were associated in the molten state, whereas a large part of their ends were free in dilute solution. Discontinuous changes were observed for low molecular weight PEO fractions crystallized from the melt, whereas continuous changes were found both for PEO's crystallized from dilute solution and those with phenylated end groups crystallized from the melt. Accordingly, it was pointed out that the association of the end groups could play an important role in the crystallization mechanism and the conformation of the resultant PEO crystals.     

Intestinal Enzyme Activities in Germfree, Conventional, and Gnotobiotic Rats Associated with Indigenous Microorganisms

Various enzyme activities involved in the active transport system, glycolysis, and digestion were assayed in various parts of the gastrointestinal tracts of germfree, conventional, and gnotobiotic rats associated with indigenous bacteria. The activity levels of alkaline phosphatase, glucose 6-phosphatase, adenosine triphosphatase, and disaccharidases in the upper small intestine were highest in all parts of the gastrointestinal tracts of various kinds of gnotobiotic, conventional, and germfree rats. Alkaline phosphatase, glucose 6-phosphatase, and adenosine triphosphatase activities in the upper small intestine of germfree rats were, respectively, 2.3-, 2.9-, and 1.7-fold higher than those in conventional rats. Similar to the results of these enzymes, sucrase, maltase, trehalase, and lactase activities in the upper small intestine of germfree rats were, respectively, 1.6-, 1.5-, 2.3-, and 1.8-fold higher than those in conventional rats. In various gnotobiotic rats, enzyme activity levels were intermediate between those in germfree and conventional rats. These findings suggest that those enzymatic activities are strongly depressed by the association with the indigenous microorganisms in the epithelial mucosa of the upper small intestine of rats. The levels of pyruvate kinase, hexokinase, and lactate dehydrogenase activities were highest, respectively, in the stomach, cecum, and the upper small intestine and cecum in all parts of the gastrointestinal tracts in various kinds of gnotobiotic, conventional, and germfree rats. It was also shown that six kinds of gastrointestinal bacteria, including lactobacilli, significantly depressed the enzyme activity levels to levels between those of the germfree and conventional rats in the upper small intestine of gnotobiotic rats.     

Somatic mosaicism of CAG repeat in dentatorubral-pallidoluysian atrophy (DRPLA)

An unstable expansion of CAG repeat in the coding region ofthe DRPLA gene on chromosome 12p is the mutation specific forhereditary dentatorubralpallidoluysian atrophy (DRPLA). We studiedthe CAG expansion in brain and other tissues from six unre latedDRPLA patients. The CAG repeat lengths showed distinct difterencesbetween tissues. The sizes of the CAG expansion in various regionsof the brain except the cerebellum were generally larger byseveral repeats than in other peripheral tissues. Brain samplesshowed greater variation of the expansion compared with othertissues, but neither the size of the CAG expansion nor the degreeof CAG repeat variation parallels the detailed findings of neuropathologicalinvolvement. We conclude that somatic instabilities of the CAGrepeat cause tissue variability of the CAG repeat size in DRPLAbut other region or cell type-specific factors would be involvedto explain the selectivity of cell damage in DRPLA.     

Malacoplakia of the endometrium. An unusual case studied by electron microscopy and a review of the literature

A rare case of malacoplakia (MKP) of the endometrium in an 88-year-old Japanese woman is presented. By light microscopy, typical Michaelis-Gutmann bodies (M-G bodies) could be identified. Electron microscopic findings revealed M-G bodies in various stages of development. These features suggested that M-G bodies were derived from round electron-dense granules that coalesced to form phagolysosomes. Early-stage M-G bodies were manifested as small, irregular, needle-shaped areas of calcification in phagolysosomes. The present paper reviews 6 cases of endometrial MKP, 5 of which have previously been reported in the literature, and this case being the sixth, to our knowledge.     

In Vitro N-Nitrosodimethylamine Formation by Some Bacteria

It was found that human pathogenic bacteria and some species of intestinal bacteria in rats have the ability to catalyze the formation of N-nitrosodimethylamine from dimethylamine and nitrate in vitro.