The Culture of the Rotifer Brachionus plicatilis with Chlorella vulgaris Containing Vitamin B12 in its Cells

The rotifer Brachionus plicatilis requires vitamin B₁₂. Freshwater Chlorella , which is produced by traditional culture, cannot support rotifer growth under bacteria-free conditions. However, Chlorella enriched with vitamin B₁₂ can support rotifer growth. To attain stable mass production of Brachionus , it is desirable to develop a food that can completely support growth of the rotifers. The authors cultured rotifers at experimental and mass culture scale with concentrated Chlorella vulgaris suspension enriched with vitamin B₁₂ in their cells.
Chlorella suspensions were prepared containing different amounts of vitamin B₁₂ in their cells, and rotifers were then cultured in 20 ml of the prepared suspensions. The highest rotifer yield was obtained from the group cultured with Chlorella containing more vitamin B₁₂ in their cells. The suitable content of vitamin B₁₂ in the concentrated Chlorella suspension commercially available for mass culture of the rotifer is considered to be 200 _μg per 100 g dry matter of Chlorella . The amount of vitamin B₁₂ necessary to produce one individual rotifer is calculated at 0.32 pg.
The authors conducted mass production of the rotifer with baker's yeast and refrigerated concentrated Chlorella containing vitamin B₁₂ Rotifer culture with vitamin B₁₂ was more stable and showed 1.3 times higher production than with normal Chlorella .     

Fate of prothiofos (O-2,4-dichlorophenyl O-ethyl S-propyl phosphorodithioate) in rats

The fate of prothiofos (O-2,4-dichlorophenyl O-ethyl S-propyl phosphorodithioate) were studied in male rats 1, 3, 8, 24, 48, and 120 hr after oral administration. In the determination of prothiofos by gas chromatography-mass spectrometry, pentadeuteroethoxy-labeled prothiofos was used as the internal standard and the carrier of residual prothiofos. Prothiofos was rapidly absorbed from the small intestine and had substantially disappeared from the gastrointestinal tract within 24 hr after dosing. The residual concentrations of prothiofos in all organs analyzed, reached a maximum at 3 hr after dosing, and then diminished exponentially. The major urinary metabolites were 2,4-dichlorophenol (21% of administered prothiofos), its conjugated substances (26%), O-2,4-dichlorophenyl O-ethyl hydrogen phosphorothioate (14%), and O-2,4-dichlorophenyl O-ethyl hydrogen phosphate (25%). While prothiofos was found in the feces (3.8%), prothiofos oxygen analog (prothiofos-oxon) was scarcely detected in any excreta. Results obtained with a single dosing of prothiofos-oxon indicated that the oxygen analog formed from prothiofos in vivo was rapidly degraded through cleavage of the PS bond and the liberation of 2,4-dichlorophenol. The low mammalian toxicity of prothiofos is probably due to depropylthiolation in the molecule.     

Effect of deoxycorticosterone acetate-salt-induced hypertension on diabetic peripheral neuropathy in alloxan-induced diabetic WBN/Kob rats

The relationship between hypertension and diabetic peripheral neuropathy (DPN) has recently been reported in clinical research, but it remains unclear whether hypertension is a risk factor for DPN. To investigate the effects of hypertension on DPN, we analyzed morphological features of peripheral nerves in diabetic rats with hypertension. Male WBN/Kob rats were divided into 2 groups: alloxan-induced diabetic rats with deoxycorticosterone acetate-salt (DOCA-salt) treatment (ADN group) and nondiabetic rats with DOCA-salt treatment (DN group). Sciatic, tibial (motor) and sural (sensory) nerves were subjected to qualitative and quantitative histomorphological analysis. Systolic blood pressure in the two groups exhibited a higher value (>140 mmHg), but there was no significant difference between the two groups. Endoneurial blood vessels in both groups presented endothelial hypertrophy and narrowing of the vascular lumen. Electron microscopically, duplication of basal lamina surrounding the endothelium and pericyte of the endoneurial vessels was observed, and this lesion appeared to be more frequent and severe in the ADN group than the DN group. Many nerve fibers of the ADN and DN groups showed an almost normal appearance, whereas morphometrical analysis of the tibial nerve showed a significant shift to smaller fiber and myelin sizes in the ADN group compared with DN group. In sural nerve, the fiber and axon-size significantly shifted to a smaller size in ADN group compared with the DN group. These results suggest that combined diabetes and hypertension could induce mild peripheral nerve lesions with vascular changes.     

Iridal coloboma induces dyscoria during miosis in FLS mice

Objective Fatty liver Shionogi (FLS) mice exhibit characteristic retinochoroidal coloboma because of a failure in fusion of the embryonic optic fissure. However, the same pathogenesis should result in iridal coloboma that has not been reported in this strain. The purpose of this study was to describe the physiologic and morphometric changes in iridal tissue involved in ocular coloboma in FLS mice. Procedures The miotic response after light exposure was evaluated in three strains of live mice, and the shape and location of the pupil were judged macroscopically. Subsequently, macroscopic abnormalities in the anterior segment and fundus were observed postmortem in all mice. During miotic and mydriatic responses in the eyes of live male FLS mice with dyscoric and normal pupils, each iris was measured in four radial directions. The enucleated eyes were examined morphometrically and histologically in both sexes of FLS mice. Results Inferior corectopia upon light‐induced miosis was clearly detected in live FLS mice. The deviated pupils were not round but oval‐shaped. Clinical and postmortem examination revealed that all dyscoric eyes had hypoplastic and dysfunctional irides inferiorly in FLS mice. Histopathological examination confirmed that both the dilator and sphincter muscles and iris stroma were quantitatively diminished in the affected inferior iris. Meanwhile, the rate of fundus (retinochoroidal) coloboma in eyes exhibiting dyscoria was remarkably high, although some dyscoric eyes had no fundus coloboma. Conclusions Fatty liver Shionogi mice had iridal coloboma, resulting in inferior corectopia upon light‐induced miosis as an indicator of ocular coloboma.     

Micropropagation of Bolaina blanca (Guazuma crinita Mart.), a fast-growing tree in the Amazon region

Rapid clonal propagation of Bolaina blanca (Guazuma crinita Mart.) was established by the subculturing of the shoot-tips from aseptically germinated seedlings on woody plant medium (WPM) supplemented with trans-zeatin [trans-6-(4-Hydroxy-3-methylbut-2-enylamino)purine] (ZEA). After 45 days of culture, a seven-fold multiplication rate was achieved on WPM containing 10 μM of ZEA. Obtained shoots were simultaneously elongated and rooted on WPM containing 1 μM of kinetin [6-furfurylaminopurine] (KIN). After 60 days of culturing the growth of shoots was evident, and high rooting percentages were obtained. The plantlets were transferred into pots with vermiculite and acclimatized successfully in plastic boxes with transparent cover inside the growth cabinet.     

Role of homestead forests in household economy and factors affecting forest production: a case study in southwest Bangladesh

Empirical information regarding the role of homestead forests in household economy is essential in understanding the importance of these resources. Identification of the factors that affect homestead forest production and understanding forest owners' attitudes toward key forest management issues have great significance in making appropriate policy responses to manage these resources on a sustainable basis. In Bangladesh, homestead forests are claimed to play an important economic role in rural livelihoods, but no reliable quantitative information exists. This study was undertaken to investigate the role of homestead forests in the household economy, examine if forest production and income vary across landholding size classes, to explore the relationships of homestead forest production with species richness, education level, and household size, and to assess the attitude of homestead forest owners toward key forest management issues. Results show that homestead forests contribute 15.9% of the household income and generate 51.4 man-days of employment per household per year. Production of homestead forests significantly varies across landholding size classes. It was observed that forest production depends significantly on species richness of homestead forests and the education level of forest owners. However, no such relationship was found between forest production and household size. The study revealed that farming families depend more on forest income than nonfarming families. Attitudes of forest owners toward key forest management issues differ significantly across landholding size classes. For example, although the majority of the forest owners prefer fruit species to timber species, the percentage of respondents decreased as the landholding size class increased, while the opposite trend was observed for timber species. The findings of this study suggest that diversification of forests and extension of education amongst forest owners would improve forest production. Furthermore, forest policy should address the concerns of the forest owners in different landholding classes and focus on their specific requirements to enhance sustainable forest management.     

Pulmonary intravascular hemangiosarcoma in a cat

A 9-year-old, castrated male Japanese domestic cat presented with a complaint of exertional dyspnea. Based on the radiographic findings, presumptive diagnosis of aspiration pneumonia or primary diffuse pulmonary neoplasia in the right middle lobe was made. Histologically, the pulmonary lesion was characterized by diffuse thickening of alveolar wall with the proliferation of apparently atypical irregular-shaped cells. Immunohistochemical staining using anti-human factor VIII-related antigen antiserum showed positive reaction in the cytoplasm of the atypical cells. According to the findings, the lesion was diagnosed as pulmonary intravascular hemangiosarcoma.     

Ammonia channel couples glutaminase with transamidase reactions in GatCAB

The formation of glutaminyl transfer RNA (Gln-tRNA(Gln)) differs among the three domains of life. Most bacteria employ an indirect pathway to produce Gln-tRNA(Gln) by a heterotrimeric glutamine amidotransferase CAB (GatCAB) that acts on the misacylated Glu-tRNA(Gln). Here, we describe a series of crystal structures of intact GatCAB from Staphylococcus aureus in the apo form and in the complexes with glutamine, asparagine, Mn2+, and adenosine triphosphate analog. Two identified catalytic centers for the glutaminase and transamidase reactions are markedly distant but connected by a hydrophilic ammonia channel 30 A in length. Further, we show that the first U-A base pair in the acceptor stem and the D loop of tRNA(Gln) serve as identity elements essential for discrimination by GatCAB and propose a complete model for the overall concerted reactions to synthesize Gln-tRNA(Gln).     

Eye fatigue-reduction effect of wood rim cover on liquid crystal display

The purpose of this study is to confirm objectively by an instrumental measurement if there is less eye fatigue in VDT work when using a wood rim covered display than when using a plastic housing display. The subjects were 26 graduate and undergraduate university students. Each subject did the same 60-min VDT activity with both a plastic housing and wood-covered display. Before and after VDT activity, each subject’s near-point accommodation distance was measured by a near-point ruler. As a result, it was confirmed that variation rate of the near-point accommodation distance by the VDT work with the wood-covered display was smaller than with the plastic housing display. From sensory tests, progression of subjective symptoms such as eye pain and headache was less with the wood-covered display than with the plastic housing display.