High production of (2s,3s)-3-hydroxy-2-methylbutanoate by immobilized plant cells of Marchantia polymorpha

Cultured plant cells of Marchantia polymorpha were examined for their ability to reduce beta-keto ester, 2-methyl-3-oxobutanoate. The cells reduced ethyl 2-methyl-3-oxobutanoate to predominantly yield the anti-product, ethyl (2S,3S)-3-hydroxy-2-methylbutanoate, with 92% diastereomeric excess and over 99% enantiomeric excess. The use of immobilized cells of M. polymorpha in calcium alginate gel improved the diastereomeric excess of the product (97% de). In addition, the large-scale reduction of 75 g of ethyl 2-methyl-3-oxobutanoate with immobilized M. polymorpha gave the product with 97% de and >99% ee in 92% yield.

Two new reactive targets of 2,5-hexanedione in vitro – beta-alanine and glycine

In this study, we found that two amino acids reacted with 2,5-hexanedione to form new reaction products in vitro, respectively. In the reaction of beta-alanine and 2,5-hexanedione, a reaction product was obtained and analyses of obtained results showed it was 3-(2,5-dimethyl-1H-pyrrol-1-yl)propanoic acid; in the reaction of glycine and 2,5-hexanedione, a reaction product was also obtained and analyses showed it was (2,5-dimethyl-1H-pyrrol-1-yl)acetic acid. Two reaction products were found to be oxidized easily; in addition, the latter was more easily to be oxidized than the former in the air. Our discoveries demonstrated that reactions between amino acids and 2,5-hexanedione could exist possibly in vitro. At present, it is clear that 2,5-hexanedione causes either axon atrophy or swelling, but the underlying molecular mechanism is still unclear. Since both beta-alanine and glycine are considered as neurotransmitter in the central nervous system, the reaction products remain to be identified in vivo.

Calcium supplementation does not reproduce the pharmacological efficacy of alfacalcidol for the treatment of osteoporosis in rats

The purpose of this study was to assess whether a nutritional supply of calcium (Ca) could be substituted for alfacalcidol (ALF) administration in preventing bone loss due to estrogen deficiency. Female Wistar-Imamichi rats (8 months old) were ovariectomized (OVX) or sham-operated. OVX rats received ALF administration (0.025, 0.5, or 0.1 microg/kg, p.o., 5 times a week) with standard rodent chow [Ca 1.2%, phosphorus (P) 1.04%], a Ca-enriched diet containing 2%, 4%, or 6% Ca (Ca/P ratio of 2, 4, and 6, respectively), or a Ca/P-enriched diet (Ca/P ratio of 1.2). After 12 weeks of treatment, all rats were killed to harvest the spine, serum, and urine samples. Neither the ALF treatment nor the Ca supplement caused hypercalcemia. In the spine, ALF prevented decreases in bone mineral density (BMD) and compressive strength of lumbar spine induced by OVX. Micro-computed tomographic analysis confirmed that ALF significantly improved the trabecular bone pattern factor and the structure model index and suppressed bone destruction. In contrast, of particular interest, high-dose Ca administration did not have marked effects on bone fragility. Also, when both Ca and P were administered in high doses, BMD and mechanical strength decreased dose-dependently, urinary P excretion significantly increased, and serum parathyroid hormone level increased. Together, it is difficult to adjust the Ca supply through diet alone without disrupting the balance between serum Ca and P levels. Consequently, we conclude that ALF is beneficial for the treatment of osteoporosis, which is not achieved by the use of a Ca supplement.

Eu-doped CsBr phosphor as a new optically-stimulable phosphor material for medical X-ray imaging sensor

CsBr phosphor ceramics doped with different luminescence centres such as In2O3, Eu2O3, EuCl3, SmCl3, TbCl3, GdCl3 or NdCl3 as the candidate for a new optically-stimulable phosphor for medical X-ray imaging sensor were prepared using a conventional ceramic fabrication process. It was found that X-ray-irradiated Eu-doped CsBr (CsBr:Eu) exhibited intense optically stimulated luminescence (OSL). The peak wavelength of the OSL emission and stimulation spectra of CsBr:Eu phosphor ceramic sample were 450 and 690 nm, respectively. The dependence of OSL properties on the conditions of preparation of phosphor ceramic samples, such as Eu concentration, sintering temperature and sintering time, were studied. The optimum preparation conditions were also studied. It was found that the OSL intensity of CsBr:Eu phosphor ceramics fabricated under optimum preparation conditions is higher than that of commercially available imaging plates using BaFBr:Eu.

Frontal N30 of median nerve SSEPs for evaluation of movement disorders with destructive basal ganglia deficits

This study was performed to show the usefulness of N30 and N20 of median nerve SSEPs for evaluating the pathogenesis of central nervous system movement disorders. The subjects were 14 patients, consisting of 7 patients with an extrapyramidal lesion, 3 patients with suspicion of hypoxic-ischemic cerebral injury before birth period (H-I group), 3 patients with kernicterus during the neonatal period (kernicterus group), and 1 patient having Wilson's disease. Seven patients had spastic hemiplegia. Patients with athetotic CP had the ability to handle an electric wheelchair alone, and those with spastic hemiplegia could walk alone. Thirty control subjects were included in this study for clinical investigation. The characteristic finding of a predominant absence or amplitude reduction of frontal N30 compared with that of parietal N20 (4 and 1, respectively, out of 6 examinations) was obtained in athetotic CP patients of the H-I group. The predominant absence of N30 compared with N20 did not appear in the kernicterus group, hemiplegic patients or a patient with Wilson's disease. Therefore, frontal N30 might sensitively reflect destructive damage in the frontal basal ganglia in children.

Intermittent exotropia surgery in children: long term outcome regarding changes in binocular alignment. A study of 666 cases

PURPOSE

To review and determine the long term outcome of surgery for intermittent exotropia in children.

CASES

A total of 666 cases were reviewed. They were 15 years old or younger and underwent surgery for intermittent exotropia during the preceding 22 years. Bilateral recession of the lateral rectus muscles was performed in 349 cases. Unilateral recession of the lateral rectus and resection of the medial rectus muscles was performed in 298 cases. One and four muscle procedures were performed in 19 cases. The outcome was evaluated at 1 month and 4 years after surgery.

RESULTS

Orthotropia or mini-microtropia was achieved in 401 patients (60.2%) one month after surgery. Bilateral recession of the lateral rectus muscles was more effective than unilateral recession- resection. Out of these 401 patients, half, 199 patients (49.6%) showed orthotropia or mini-microtropia 4 years after surgery while the other half, 202 (50.4%), became exotropic. Bilateral recession of the lateral rectus muscles was also more effective in producing orthotropia or mini-microtropia on a long term basis than unilateral recession-resection. The rate of orthotropia or mini- microtropia was higher when the patients were operated before 3 years and after 11 years of age.

CONCLUSIONS

There was a strong tendency for intermittent exotropia to recurr and drift into permanent exotropia during 4 or more years following surgery. It is advocated to aim at orthotropia during the immediate post- surgical period and to avoid overcorrection. Early surgery is not necessary when the patient is over 4 years of age. Bilateral lateral rectus recession is the preferred surgical procedure.

The mechanisms by which both heterozygous peroxisome proliferator-activated receptor gamma (PPARgamma) deficiency and PPARgamma agonist improve insulin resistance

Peroxisome proliferator-activated receptor (PPAR) gamma is a ligand-activated transcription factor and a member of the nuclear hormone receptor superfamily that is thought to be the master regulator of fat storage; however, the relationship between PPARgamma and insulin sensitivity is highly controversial. We show here that supraphysiological activation of PPARgamma by PPARgamma agonist thiazolidinediones (TZD) markedly increases triglyceride (TG) content of white adipose tissue (WAT), thereby decreasing TG content of liver and muscle, leading to amelioration of insulin resistance at the expense of obesity. Moderate reduction of PPARgamma activity by heterozygous PPARgamma deficiency decreases TG content of WAT, skeletal muscle, and liver due to increased leptin expression and increase in fatty acid combustion and decrease in lipogenesis, thereby ameliorating high fat diet-induced obesity and insulin resistance. Moreover, although heterozygous PPARgamma deficiency and TZD have opposite effects on total WAT mass, heterozygous PPARgamma deficiency decreases lipogenesis in WAT, whereas TZD stimulate adipocyte differentiation and apoptosis, thereby both preventing adipocyte hypertrophy, which is associated with alleviation of insulin resistance presumably due to decreases in free fatty acids, and tumor necrosis factor alpha, and up-regulation of adiponectin, at least in part. We conclude that, although by different mechanisms, both heterozygous PPARgamma deficiency and PPARgamma agonist improve insulin resistance, which is associated with decreased TG content of muscle/liver and prevention of adipocyte hypertrophy.

Increased expression of the sterol regulatory element-binding protein-1 gene in insulin receptor substrate-2(-/-) mouse liver

Insulin receptor substrate (IRS)-2(-/-) mice develop diabetes because of insulin resistance in the liver and failure to undergo beta-cell hyperplasia. Here we show by DNA chip microarray analysis that expression of the sterol regulatory element-binding protein (SREBP)-1 gene, a downstream target of insulin, was paradoxically increased in 16-week-old IRS-2(-/-) mouse liver, where insulin-mediated intracellular signaling events were substantially attenuated. The expression of SREBP-1 downstream genes, such as the spot 14, ATP citrate-lyase, and fatty acid synthase genes, was also increased. Increased liver triglyceride content in IRS-2(-/-) mice assures the physiological importance of SREBP-1 gene induction. IRS-2(-/-) mice showed leptin resistance; low dose leptin administration, enough to reduce food intake and body weight in wild-type mice, failed to do so in IRS-2(-/-) mice. Interestingly, high dose leptin administration reduced SREBP-1 expression in IRS-2(-/-) mouse liver. Thus, IRS-2 gene disruption results in leptin resistance, causing an SREBP-1 gene induction, obesity, fatty liver, and diabetes.