Biochemical Study on the Critical Period for Treatment of the Mottled Brindled Mouse

Hemizygous mottled brindled mice (Mobr/y mice) were treated by subcutaneous injection of copper and were decapitated on postnatal day 14. Cytochrome c oxidase (COX) activity of the brain mitochondria in the mice given 10 micrograms of copper/g on day 4 or 7 showed significant increases compared with that of untreated Mobr/y animals, and these mice had no neurological symptoms. Mice given 10 micrograms of copper/g on day 12 showed neither increases in COX activity nor clinical improvement. The brain levels of copper, noradrenaline, and dopamine in the mice treated on day 12 were the same as those in animals treated on day 4 or 7. The in vitro activities of dopamine-beta-hydroxylase of the brain were also the same among the treated mice, irrespective of the date of treatment. The results indicate that delays in copper treatment produce irreversible changes in COX activity of the brain and lead to clinical unresponsiveness to treatment.     

Localization of blood coagulation factors and fibrinolysis factors within lymphoid germinal centers in human lymph nodes.

The presence of nineteen blood coagulation factors and fibrinolysis factors was immunohistochemically evaluated in human lymph node germinal centers (GCs). Twelve of these factors were detected within lymphoid GCs. The predominant pattern was dendritic with occasional crescent-shaped, ring-shaped or 'moth-eaten' appearance. Immunostains of factor VIII-related antigen, factor I, protein C, tetranectin, antithrombin III, type 2-plasminogen activator inhibitor, and alpha 2-plasmin inhibitor were almost entirely absent from GCs, although they reacted in vascular wall and lumen, respectively. The immunostaining to high molecular weight kininogen, kallikrein, factors XII, X, V, II, XIIIa, XIIIs, plasminogen, tissue-plasminogen activator, and type 1-plasminogen activator inhibitor more frequently revealed a positive dendritic pattern. Immuno-electron microscopy demonstrated factor X and factor XIIIa attached to the cell surfaces of lymphocytes, macrophages, and follicular dendritic cells (FDCs); and in the intercellular space within GCs, especially attached to the labyrinthine-like structure of FDCs. No reaction products were observed in the perinuclear cisternae and rough endoplasmic reticulum in either lymphocytes or FDCs. Our data demonstrate that human lymphoid GCs really contain some of the proteins related to the blood coagulation and fibrinolysis cascades.     

Sleep‐related behaviors in zoo‐housed giraffes (Giraffa camelopardalis reticulata): Basic characteristics and effects of season and parturition

Despite increasing interest in the behavior of zoo animals, studies of nocturnal behavior of zoo animals are limited. In this study, we investigated the relationship between parturition, season, and the sleep‐related behaviors in captive reticulated giraffes to better understand the nocturnal life in giraffes. The subjects were two adult reticulated giraffes living in Kyoto City Zoo, Japan. Observations were made via an infrared camera that was mounted in the indoor enclosure between June 2007 and August 2009. We analyzed video clips that were recorded between 16:30 and 09:00 the next morning, over a total of 199 days. Sleep‐related behaviors were classified into two categories based on the posture of the giraffes; recumbent posture and paradoxical sleep. We also recorded the laterality of recumbent posture, which was coded based on the direction of the legs against the torso (right or left). Seasonal differences in sleep behaviors between summer and winter were observed in both individuals. They tended to start to lie down earlier in the winter than in the summer. Parturition also affected the behaviors as both individuals decreased the behaviors before and after the parturition of the female. Additionally, the female lay on her left side less frequently than her right when resuming a recumbent posture in the pre‐parturition period, while such laterality was not observed in the baseline and post‐parturition period. These results suggested that season and parturition are important factors for determining the sleep‐related behaviors in giraffes. Further studies are needed to understand how these changes in sleep affect other welfare parameters.     

Purification and properties of an acid endo-1,4-beta-glucanase from Bacillus sp. KSM-330

A novel acid cellulase (endo-1,4-beta-glucanase, EC 3.2.1.4) was found in a culture of Bacillus sp. KSM-330 isolated from soil. One-step chromatography on a column of CM-Bio-Gel A yielded a homogeneous enzyme, as determined by silver staining of both sodium dodecyl sulphate (SDS) and nondenaturing gels. The enzyme had a molecular mass of 42 kDa, as determined by SDS-polyacrylamide gel electrophoresis. The isoelectric point was higher than pH 10. The N-terminal amino acid sequence of the enzyme was Val-Ala-Lys-Glu-Met-Lys-Pro-Phe-Pro-Gln-Gln-Val-Asn-Tyr-Ser-Gly-Ile-Leu- Lys-Pro . This enzyme had an optimum pH for activity of 5.2, being active over an extremely narrow range of pH values, from 4.2 to 6.9; below and above these pH values no activity was detectable. The optimum temperature at pH 5.2 was around 45 degrees C. The enzyme efficiently hydrolysed carboxymethylcellulose (CMC) and lichenan, but more crystalline forms of cellulose, curdlan, laminarin, 4-nitrophenyl-beta-D-glucopyranoside and 4-nitrophenyl-beta-D-cellobioside were barely hydrolysed. The enzymic activity was inhibited by Hg2+ but was not affected by other inhibitors of thiol enzymes, such as 4-chloromercuribenzoate. N-ethylmaleimide and monoiodoacetate. N-Bromosuccinimide abolished the enzymic activity, and CMC protected the enzyme from inactivation by this tryptophan-specific oxidant. It is suggested that a tryptophan residue(s) is involved in the mechanism of action of the Bacillus cellulase and that the inhibition of enzymic activity by Hg2+ is ascribable to interactions with the tryptophan residue(s) rather than with thiol group(s).     

Role of the mature protein sequence of maltose-binding protein in its secretion across the E. coli cytoplasmic membrane

Secretion of amber fragments of an E. coli periplasmic protein, the maltose-binding protein, was studied to determine if the mature portion of the protein is required for its export across the cytoplasmic membrane. A fragment lacking 25–35 amino acid residues at the C terminus is secreted at normal levels, suggesting that this sequence is not required for secretion. This is in contrast to the results obtained with the periplasmic protein β-lactamase. In studying another fragment of one-third the molecular weight of the intact protein, we found that the majority of the fragment is not recovered from the periplasmic fraction. However, a small amount of secretion of this polypeptide was observed. This fragment is synthesized as a larger molecular weight form when cells are induced for the synthesis of a maltose-binding protein-β-galactosidase hybrid protein, which was previously shown to block the proper localization and processing of envelope proteins. This result is consistent with the idea that the larger form is a precursor with an unprocessed signal sequence, whereas in the absence of the hybrid protein the fragment is a processed mature form. Thus secretion of the smaller fragment may be occurring up to the point where the signal sequence is removed. That this fragment has passed through the cytoplasmic membrane is further supported by its accessibility to externally added trypsin. We suggest that the fragment may be secreted to the periplasm, but cannot assume a water-soluble conformation; the majority of the polypeptide may be associated with the external surface of the cytoplasmic membrane. Thus the mature sequence of maltose-binding protein, at least its C-terminal two thirds, may not be required for its export across the cytoplasmic membrane.     

Preparation of eumelanin-related metabolites 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, and their O-methyl derivatives

5,6-Dihydroxyindole (5,6DHI) and 5,6-dihydroxyindole-2-carboxylic acid (5,6DHI2C) are ultimate precursors of the black melanin, eumelanin. These indolic metabolites and their O-methyl derivatives are excreted in urine of melanoma patients at high levels and of healthy persons at low levels. We describe here a simplified procedure for preparing milligram to subgram quantities of 5,6DHI and 5,6DHI2C and their O-methyl derivatives. Dopachrome generated in situ by ferricyanide oxidation of dopa at pH 6.5 underwent spontaneous decarboxylation to give 5,6DHI in 40% isolation yield, while treatment of dopachrome with alkali at pH 13 afforded 5,6DHI2C in 38% isolation yield. Two isomeric O-methyl derivatives of 5,6DHI were prepared by treatment with diazomethane, while those of 5,6DHI2C were prepared by treatment with diazomethane followed by alkaline hydrolysis of the methyl esters. 5,6DHI and 6-hydroxy-5-methoxyindole were also obtained by heating the corresponding carboxylic acids in decalin. 5-Hydroxy-6-methoxyindole and 6-hydroxy-5-methoxyindole-2-carboxylic acid could also be prepared by debenzylation of the commercially available O-benzyl derivatives.