Effect of reduced sulfur compounds on the fermentation of phosphoric acid pretreated sugarcane bagasse by ethanologenic Escherichia coli

The addition of reduced sulfur compounds (thiosulfate, cysteine, sodium hydrosulfite, and sodium metabisulfite) increased growth and fermentation of dilute acid hydrolysate of sugarcane bagasse by ethanologenic Escherichia coli (strains LY180, EMFR9, and MM160). With sodium metabisulfite (0.5mM), toxicity was sufficiently reduced that slurries of pretreated biomass (10% dry weight including fiber and solubles) could be fermented by E. coli strain MM160 without solid-liquid separation or cleanup of sugars. A 6-h liquefaction step was added to improve mixing. Sodium metabisulfite also caused spectral changes at wavelengths corresponding to furfural and soluble products from lignin. Glucose and cellobiose were rapidly metabolized. Xylose utilization was improved by sodium metabisulfite but remained incomplete after 144 h. The overall ethanol yield for this liquefaction plus simultaneous saccharification and co-fermentation process was 0.20 g ethanol/g bagasse dry weight, 250 L/tonne (61 gal/US ton).

Minimum Grain Size in Nanocrystalline Metal Powders

Nanocrystalline metal powders can be synthesized by mechanical attrition in a highenergy ball mill. A general relation determining the grain size of these materials is inferred. The ultimate grain size of nanocrystalline metals (typically 6 − 22 nm) is governed by the competition between the severe plastic deformation introduced during ball milling and the recovery behavior of the material. The lower bound grain size achievable by mechanical attrition is given by the minimum distance between two dislocations in a pile-up within a grain for all pure metals. Foar binary alloys the ultimate grain size depends on the composition of the material. Varying the composition changes the grain size reversibly. This can be explained by introducing solid solution hardening effects in the general relation for the lower bound grain size in pure metals. Thus, the proposed model for the ultimate grain size achievable by ball milling seems to be. applicable to all metals and alloys subjected to heavy mechanical deformation. However, reversible grain size changes are not restricted to mechanical attrition, but have also been observed for nanocrystalline Pd-H solid solutions produced by hydriding at constant pressure. Solid solutions prepared at different compositions, i.e. samples with different compositions, exhibit different grain sizes. Cycling between different temperatures/compositions changes the grain size reversibly. This cannot be explained by a model based on plastic deformation as in the case of ball-milled metal powders. The results are compared with data for ball-milled powders and samples prepared by inert gas condensation. The grain size changes are discussed with respect to the compositional changes and the grain boundary energy of the material.

Haplotype-based case-control study on human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 gene and essential hypertension

BACKGROUND

Oxidative DNA damage is involved in the pathophysiology of essential hypertension (EH), which is a multifactorial disorder. Apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/REF-1) is an essential endonuclease in the base excision repair pathway of oxidatively damaged DNA, in addition to having reducing properties that promote the binding of redox-sensitive transcription factors. Blood pressure in APE1/REF-1-knockout mice is reported to be significantly higher than in wild-type mice. The aim of this study was to investigate the relationship between EH and the human APE1/REF-1 gene through a haplotype-based case-control study using single-nucleotide polymorphisms (SNPs).

METHODS

We selected five SNPs in the human APE1/REF-1 gene (rs1760944, rs3136814, rs17111967, rs3136817, and rs1130409), and performed case-control studies in 265 EH patients and 266 age-matched normotensive (NT) subjects.

RESULTS

rs17111967 was found to show nonheterogeneity among Japanese subjects. There were no significant differences in the overall distribution of genotypes or alleles for each SNP between EH and NT groups. In the overall distribution of the haplotype-based case-control study constructed based on rs1760944, rs3136817, and rs1130409, the frequency of the G-T-T haplotype was significantly higher in the EH group than in the NT group (2.1% vs. 0.0%, P = 0.001). Multiple logistic regression analysis also revealed significant differences for the G-T-T haplotype, even after adjustment for confounding factors (OR = 8.600, 95% CI: 1.073-68.951, P = 0.043).

CONCLUSIONS

Based on the present results, the G-T-T haplotype appears to be a genetic marker of EH, and the APE1/REF-1 gene appears to be a susceptibility gene for EH.

Resetting process of peripheral circadian gene expression after the combined reversal of feeding schedule and light/dark cycle via a 24-h light period transition in rats

To investigate the effect of light cue on the resetting of the peripheral clocks, we examined the resetting processes of clock genes (Per1, Per2, Bmal1, Cry1, Dec1, and Rev-erbalpha) in the liver and heart of rats after the feeding and light-dark (LD) reversal via a 24-h light period transition. The liver clock was reset quickly within 3 days, while the heart clock needed a longer time course of 5-7 days to be completely re-entrained. Moreover, the re-entrainment of Per1 and Per2 in the liver clock was more rapid than that of the other four clock genes, suggesting the important role of these two clock genes in initiating the circadian resetting of the hepatic clock. However, the resetting rates of these two clock genes were as similar as the others in the heart clock. Therefore, the resetting mechanisms underlining these two peripheral clocks may be totally distinct. Furthermore, the re-entrainment of the liver and heart clocks were relatively lengthened after the feeding and LD reversal via a light period transition compared to a dark period transition, suggesting a simultaneous shift of feeding schedule and the LD cycle may facilitate the circadian resetting in rats.

Visual computing in electron crystallography

VEC is a program package for Visual computing in Electron Crystallography. The program is written mainly in C++ and Fortran and is for running under MS Windows 95, 98, NT and 2000. Apart from its user-friendly interface, sophisticated text-sensitive online helps and tutorials, VEC includes same unique crystallographic methods. They are direct-method image-processing techniques, ab-initio solution of incommensurate crystal structures and algorithms for searching one-dimensionally modulated atoms in 4-dimensional Fourier maps. Examples are given in details.

Haplotype-based case-control study of receptor (calcitonin) activity-modifying protein-1 gene in cerebral infarction

Calcitonin gene-related peptide (CGRP) receptor is a complex molecule that consists of calcitonin receptor-like receptor and receptor activity-modifying protein-1 (RAMP1). It was recently reported that RAMP1-deficient mice (RAMP1(-/-)) showed inflammatory responses with a transiently significant increase in serum CGRP levels and proinflammatory cytokines when compared with RAMP1(+/+) mice. The aim of this study was to investigate the relationship between the human RAMP1 gene and cerebral infarction (CI) using single-nucleotide polymorphisms (SNPs) in a Japanese population. We selected six SNPs in the human RAMP1 gene (rs3754701, rs3769048, rs7557078, rs1584243, rs10199956 and rs7590387) and performed a case-control study using each SNP and haplotype in 171 CI patients and 234 controls. There were no significant differences in overall distribution of genotype and allele frequencies of the SNPs between the CI and control groups. However, there was a significant difference in overall distribution between the CI and control groups (P<0.001) in the haplotype-based case-control study with the combinations of rs3754701-rs3769048-rs7590387. The T-A-C susceptibility haplotype for CI was significantly more frequent than in the control group (P=0.0024). The results suggest that the T-A-C haplotype is a genetic marker for CI, and that RAMP1 or neighbouring genes are associated with increased susceptibility to CI.

Vasorelaxing action of vasonatrin peptide is associated with activation of large-conductance Ca(2+)-activated potassium channels in vascular smooth muscle cells

The aim of this study was to test the hypothesis that vasorelaxing action of vasonatrin peptide (VNP) is due to activation of the large-conductance Ca(2+)-activated potassium channel (BK(Ca)) via guanylyl cyclase (GC)-coupled natriuretic peptide receptors (NPRs) in vascular smooth muscle cells (VSMCs). Contraction experiments were performed using human radial artery, whereas BK(Ca) current by patch clamp was recorded in cells from rat mesenteric artery. Contractility of rings cut from human radial artery was detected in vitro. As a result, VNP induced a dose-dependent vasorelaxation of human radial artery, which could be mimicked by 8-Br-cGMP, and suppressed by TEA, a blocker of BK(Ca), HS-142-1, a blocker of GC-coupled NPRs, or methylene blue (MB), a selective inhibitor of guanylyl cyclase. Sequentially, whole-cell K(+) currents were recorded using patch clamp techniques. BK(Ca) current of VSMCs isolated from rat mesentery artery was obtained by subtracting the whole cell currents after applications of 10(-7) mol/l iberiotoxin (IBX) from before its applications. In accordance with the results of arterial tension detection, BK(Ca) current was significantly magnified by VNP, which could also be mimicked by 8-Br-cGMP, whereas suppressed by HS-142-1, or MB. Taken together, VNP acts as a potent vasodilator, and NPRA/B-cGMP-BK(Ca) is one possible signaling system involved in VNP induced relaxation.

Compare the diagnostic value of FLT and FDG PET/CT in assessment of regional lymph nodes in thoracic esophageal squamous cell carcinoma

e15620

Background: To determine whether FLT PET/CT can detect regional lymph nodes metastases in untreated thoracic esophageal squamous cell carcinoma. In view of the reported high sensitivity of FDG PET/CT for the evaluation of thoracic nodules of esophageal carcinoma, we additionally performed FDG PET/CT for direct comparison with that of FLT. Methods: From March 2008 to December 2008, 18 patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing side-by-side FDG PET/CT and FLT PET/CT images for the diagnosis of locoregional lymph node metastases were compared prospectively in relation to pathologic findings. The PET images were visually inspected with the maximum standardized uptake value (SUVmax) determined from a circular region of interest (ROI) over the entire lesion. The differential threshold for malignancy was set as SUVFDG≥2.5, and SUVFLT≥1.4, respectively. Results: All patients underwent esophagectomy and lymphadenectomy, and pathologic examination confirmed nodes positive for metastasis in 14 patients and 42 of 344 excised nodes. The uptake of FDG (median SUVmax, 5.59; range, 2.5–10.6) in locoregional lymph nodes metastasis was significantly higher than that of FLT (median SUVmax, 2.93; range, 1.6–4.6). There were 14 false positive nodes in FDG PET and only 3 in FLT PET, 7 false negative nodes in FDG PET, while 11 false negative nodes in FLT PET. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 73.81%, 99.01%, 95.93%, 91.18% and 96.45%, respectively, whereas those of FDG PET/CT were 83.33%, 95.36%, 93.90%, 71.43% and 95.36%, respectively. P values were 0.425, 0.014, 0.298, 0.055, and 0.541, respectively. Conclusions: FLT uptake in regional lymph node of esophageal carcinoma is significantly lower compared with FDG uptake.FLT PET has fewer false-positive findings compared with FDG PET. The specificity of FLT PET/CT is higher than that of FDG. We suggest that esophageal carcinoma N-staging need to combine FLT with FDG PET/CT images.

No significant financial relationships to disclose.

The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera

The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period.

Comparison of gross tumor volume delineated by anatomic imaging and FDG PET/CT for esophageal carcinoma and validation with pathological specimen

15090

Background: Although results of clinical studies have demonstrated FDG PET/CT improved target volume delineation in various tumors, only few studies compared delineation based on PET/CT with pathologic examination. Aim of our study was to compare anatomic imaging modalities including computed tomography (CT), esophagram, endoscopy with FDG PET/CT for delineation of gross tumor volume (GTV) in esophageal carcinoma and to validate the results with the pathologic examination. Methods: Thirty patients with stages II-III squamous cell carcinoma underwent transthoracic esophagectomy were enrolled. PET/CT, esophagram and endoscopy were performed with patients before operations. The length of the lesion on the PET/CT scan and on the CT portion of the PET/CT and the PET scan alone was determined independently by 3 separate investigative groups. PET/CT scan was evaluated by visual inspection for abnormality. A standard uptake value (SUV) of 2.5 was used in the PET scan to delineate the tumor extent. The lengths of GTVs determined with the five modalities (PET/CT, PET, CT, esophagram and endoscopy) were compared quantitatively and validated with the pathologic specimen. The sizes of the tumors were measured by pathologic examination which was considered as the gold standard. Results: Of the 30 patients, 9 had T2 tumors, 20 had T3 tumors and 1 had T4 tumor with an involvement of pleura. Three tumors were located at the upper esophagus, 14 at the middle esophagus, 13 at the lower esophagus. The mean length of the carcinoma was 5.85cm(SD 2.50cm) measured by pathologic examination, 5.79cm (SD 2.04cm) as determined by PET scan, 5.14cm (SD 1.65cm) by PET/CT scan, 5.42 cm(SD 2.42cm)by CT scan, 5.50cm(SD 2.79cm) by endoscopy, and 6.07cm(SD 2.75cm) by esophagram respectively. Although the lengths of the tumors as measured by the five imaging modalities were no significant difference, the result of PET was the most accurate. Conclusions: Compared with tumor lengths measured by pathologic examination, PET with a SUV 2.5 was found to be the most accurate modality and can help the radiation oncologist delineate the GTV of esophageal carcinoma precisely.

No significant financial relationships to disclose.

The human lung: did evolution get it wrong?

Some 300 million yrs ago, the ancestors of modern reptiles emerged from water and were committed to air breathing. They were exothermic and incapable of sustained levels of high physical activity. But from them evolved the two great classes of vertebrates with high levels of maximal oxygen consumption: the mammals and birds. A remarkable feature of these two divergent evolutionary lines is that, although the physiology of many organ systems shows many similarities, the lungs are radically different. A major difference is that the ventilation of the gas-exchanging tissue has a flow-through pattern in the bird but is reciprocating in the mammal. The result is that mammals have a reduced alveolar and arterial oxygen tension, a potential for uneven ventilation, and relatively large terminal air spaces. This in turn means that the pulmonary capillaries are poorly supported compared with the bird. The result is that the pulmonary capillaries in the bird have much thinner and more uniform walls, with more efficient gas exchange. Other advantages of the bird lung are that it utilises a more efficient cross-current pattern of gas-exchange, and the bird has separated the ventilatory and gas exchange functions. From a structure-function standpoint, the bird lung is superior.

A randomized clinical study of surgery versus radiotherapy in the treatment of resectable esophageal cancer

4013

Background: To compare the treatment results between radical surgery and late-course accelerated hyperfractionation radiotherapy (LCAHFR) for patients with resectable thoracic segment esophageal cancer. Methods: From June 1998 to September 2002, 269 patients with resectable thoracic esophageal cancer were randomized into two groups. 135 were with surgery and 134 with late-course accelerated hyperfractionated (LCAF) radiotherapy. Chemotherapy only for clinical recurrence and salvage therapy. Results: The 1-, 3- and 5- year overall survival rate were 88.6%, 56.2% and 34.7% in the surgery group and 93.3%, 61.5% and 36.9% in the radiotherapy group. There was no statistical difference between the two groups (P =0.58). Median survival was 28.5 months and 30.5 months respectively. The 1-, 3-and 5-year progression-free survival rate was 73.3%, 39.7% and 20.6% in the surgery group and 75.9%, 43.7% and 23.1% in the radiotherapy group (P =0.65) . There was no difference between the two groups in survival rates including different location and length (P > 0.05). The incidence of failure by hematogenous metastasis and distant lymphatic metastasis in the radiotherapy group (16.6% and 13.3% respectively ) was lower than in the surgery group ( 25.3% and 20.3 % respectively ), there was no significance between them. The incidence of local failure in the radiotherapy and surgery group was 57.3% and 27.8% respectively (P = 0.001) The incidence of death by local reasons was higher than in the surgery group (P = 0.02 ). The incidence of death by distant metastasis was lower than in the surgery group (P = 0.02 ). Conclusion: The treatment results between radical surgery and LCAHFR with conformal radiotherapy for patients with resectable thoracic esophageal cancer were comparable.

No significant financial relationships to disclose.

The GATA site-dependent hemogen promoter is transcriptionally regulated by GATA1 in hematopoietic and leukemia cells

Hemgn (a gene symbol for hemogen in mouse, EDAG in human and RP59 in rat) encodes a nuclear protein that is highly expressed in hematopoietic tissues and acute leukemia. To characterize its regulatory mechanisms, we examined the activities of a Hemgn promoter containing 2975 bp of 5' flanking sequence and 196 bp of 5' untranslated region (5' UTR) sequence both in vitro and in vivo: this promoter is preferentially activated in a hematopoietic cell line, not in nonhematopoietic cell lines, and is sufficient to drive the transcription of a lacZ transgene in hematopoietic tissues in transgenic mice. Mutagenesis analyses showed that the 5' UTR including two highly conserved GATA boxes is critical for the promoter activity. GATA1, not GATA2, binds to the GATA binding sites and transactivates the Hemgn promoter in a dose-dependent manner. Furthermore, the expression of human hemogen (EDAG) transcripts were closely correlated with levels of GATA1 transcripts in primary acute myeloid leukemia specimens. This study suggests that the Hemgn promoter contains critical regulatory elements for its transcription in hematopoietic tissues and Hemgn is a direct target of GATA1 in leukemia cells.

Prenatal echocardiographic differential diagnosis of fetal cardiac tumors

OBJECTIVES

To present data on echocardiographic findings of fetal cardiac tumors and discuss their differential diagnoses.

METHODS

We retrospectively reviewed 14 cases of fetal echogenic cardiac mass diagnosed between 1990 and 2003; 12 were confirmed to be cardiac tumors and two were false-positive diagnoses. The echocardiographic characteristics examined included number, size, location and associated complications.

RESULTS

Eight fetuses had a single tumor and four fetuses had multiple tumors. The left ventricle was most often affected. Parents of eight fetuses opted for termination of pregnancy, one fetus died in utero and three affected fetuses survived. Histopathological examination revealed cardiac rhabdomyoma in six fetuses, fibroma in two, teratoma in two, lipoma in one and hemangioma in one. The pitfalls associated with prenatal echocardiographic diagnosis of cardiac tumors include: they may be too small to be visualized, intracardiac echogenic foci may mimic tumors, and echogenicity resulting from extracardiac structures or neoplasms near the heart may falsely appear as tumors.

CONCLUSION

Fetal cardiac tumors can be detected by echocardiography. However, differential diagnosis is important as this will affect prognosis and subsequent management.

Nutritional and hormonal factors control the gene expression of FoxOs, the mammalian homologues of DAF-16

Transcription factors of the FoxO family in mammals are orthologues of the Caenorhabditis elegans forkhead factor DAF-16, which has been characterized as a target of insulin-like signalling. Three members of this family have been identified in rodents: FoxO1, FoxO3 and FoxO4, originally termed FKHR, FKHRL1 and AFX respectively. A number of in vitro studies have revealed that FoxOs are regulated through phosphorylation in response to insulin and related growth factors, resulting in their nuclear exclusion and inactivation. To clarify the mechanisms involved in the regulation of these factors in vivo, we investigated in the present study whether or not, and if so how, their mRNA levels in rat liver respond to the stimuli of several nutritional and hormonal factors. Imposed fasting for 48 h significantly elevated mRNA levels of FoxO1 (1.5-fold), FoxO3 (1.4-fold), and FoxO4 (1.6-fold). Refeeding for 3 h recovered the induced mRNA levels of FoxO1 and FoxO3 to the control levels, but did not affect that of FoxO4. FoxO1 and FoxO4 mRNA levels were proved to be highly reflective of their protein levels measured by Western immunoblotting. Of the three FoxO genes, FoxO4 only showed altered levels of mRNA (a 1.5-fold increase) in response to a protein-free diet. Streptozotocin-induced diabetes for 28 days decreased hepatic mRNA levels of FoxO1 and FoxO3 and increased the level of FoxO4 mRNA, but short-term (7 days) diabetes had fewer effects on the expression of these genes. Insulin replacement partially restored the FoxO1 and FoxO4 mRNA levels, but had no effect on the FoxO3 mRNA level. Daily administration for 1 week of dexamethasone, a synthetic glucocorticoid, increased the mRNA levels of FoxO1 (1.8-fold) and FoxO3 (2.4-fold). These results show that the FoxO genes respond differently to nutritional and hormonal factors, suggesting a new mechanism for the regulation of FoxO-dependent gene expression by these factors. Moreover, changes of FoxO1 and FoxO4 in the nucleus in response to fasting also suggest that the regulation of nucleus/cytoplasm translocation actually functions in vivo.

Routine screening mammography: how important is the radiation-risk side of the benefit-risk equation?

The potential radiation hazards associated with routine screening mammography, in terms of breast cancer induction, are discussed in the context of the potential benefits. The very low energy X-rays used in screening mammography (26-30 kVp) are expected to be more hazardous, per unit dose, than high-energy X- or gamma-rays, such as those to which A-bomb survivors (from which radiation risk estimates are derived) were exposed. Based on in vitro studies using oncogenic transformation and chromosome aberration end-points, as well as theoretical estimates, it seems likely that low doses of low-energy X-rays produce an increased risk per unit dose (compared with high energy photons) of about a factor of 2. Because of the low doses involved in screening mammography, the benefit-risk ratio for older women would still be expected to be large, though for younger women the increase in the estimated radiation risk suggests a somewhat later age than currently recommended--by about 5-10 years--at which to commence routine breast screening.

Relationship of large multifunctional proteasome 7 gene polymorphism with susceptibility to type 1 diabetes mellitus and DR3 gene

OBJECTIVE

To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.

METHODS

LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A < or = 14 years, group B 15-30 years, group C > or = 31 years.

RESULTS

In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P < 0.05) and that of LMP7-B/A was higher (54% vs 31%, P < 0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P < 0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.

CONCLUSIONS

LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.

[Protective effect of huyin decoction on acute hepatic injury induced by CCl4 in mice]

OBJECTIVE

To observe the protective effect of Huyin decoction on acute hepatic injury induced by CCl4 in mice.

METHODS

The model of acute hepatic injury induced by CCl4 was used. The levels of ALT and AST in serum were detected. And histopathology of liver was observed.

RESULTS

Huyin decoction could decrease ALT and AST in serum and hepatic histopathological injury of the acute hepatic injury mice.

CONCLUSION

Huyin decoction possessed protective effect on acute hepatic injury in mice.

Proline-based P, N ligands in asymmetric allylation and the Heck reaction

A series of phosphine-oxazoline ligands based on proline are reported. These ligands are synthesized from commercially available trans-4-hydroxy-L-proline in four steps. The ability of this type of ligand to catalyze allylic alkylation in an asymmetric fashion as well as the asymmetric Heck reaction is reported. The best of these ligands gave a palladium complex, which catalyzed the addition of dimethylmalonate to cyclopentenyl acetate in excellent yield and up to 96% ee. This same system catalyzed the Heck reaction between dihydrofuran and cyclohexene in up to 86% ee. These ligands appear to differ from the traditional phosphine-oxazoline ligands in that the stereochemistry of the stereogenic carbon next to the oxazoline is not necessarily the dominant chiral center in the induction of selectivity.

Regulation of hydroxyindole-O-methyltransferase gene expression in Japanese quail (Coturnix coturnix japonica)

Hydroxyindole-O-methyltrasferase (HIOMT) plays an important role as the final enzyme in the synthesis of melatonin. In this study, the expression of the HIOMT gene in Japanese quail was investigated with respect to tissue distribution and the effects of light and vitamin A deficiency. HIOMT mRNA in the pineal gland and eye had a clear daily rhythm with peak values in daytime. The testis also contained a detectable amount of HIOMT mRNA, which did not display a rhythmic change over a 24-h period. When birds were rendered vitamin A deficient through feeding with a vitamin A-free diet, the daily rhythm of the HIOMT gene almost disappeared in both the pineal gland and eye due to increases in the nighttime values. Our previous observations and these results suggest that vitamin A and a photo-signal are required to maintain the rhythmic expression of the HIOMT gene as well as the arylalkylamine N-acetyltransferase gene.

The telemedicine network of the People's Liberation Army

In the early 1990s, the People's Liberation Army began to establish a telemedicine network for the non-emergency health-care of the personnel of military units and their families, as well as local civilian patients. All data were transferred over the ordinary telephone network. All the stations were uniformly equipped with PCs containing videoconferencing cards. The network comprised 13 management centres and 208 teleconsultation stations. To evaluate the telemedicine service, we conducted a survey with written questionnaires and telephone interviews. The questionnaire was sent to the person responsible for each telemedicine station. A total of 187 questionnaires were returned, a response rate of 85%. The survey showed that 1503 teleconsultation sessions had been conducted for military as well as civilian patients during the 18-month study period, and 1708 static images had been transferred across the network during these sessions.

Interaction of 3,4-dienoyl-CoA thioesters with medium chain acyl-CoA dehydrogenase: stereochemistry of inactivation of a flavoenzyme

The medium chain acyl-CoA dehydrogenase is rapidly inhibited by racemic 3,4-dienoyl-CoA derivatives with a stoichiometry of two molecules of racemate per enzyme flavin. Synthesis of R- and S-3,4-decadienoyl-CoA shows that the R-enantiomer is a potent, stoichiometric, inhibitor of the enzyme. alpha-Proton abstraction yields an enolate to oxidized flavin charge-transfer intermediate prior to adduct formation. The crystal structure of the reduced, inactive enzyme shows a single covalent bond linking the C-4 carbon of the 2,4-dienoyl-CoA moiety and the N5 locus of reduced flavin. The kinetics of reversal of adduct formation by release of the conjugated 2,4-diene were evaluated as a function of both acyl chain length and truncation of the CoA moiety. The adduct is most stable with medium chain length allenic inhibitors. However, the adducts with R-3,4-decadienoyl-pantetheine and -N-acetylcysteamine are some 9- and >100-fold more kinetically stable than the full-length CoA thioester. Crystal structures of these reduced enzyme species, determined to 2.4 A, suggest that the placement of H-bonds to the inhibitor carbonyl oxygen and the positioning of the catalytic base are important determinants of adduct stability. The S-3,4-decadienoyl-CoA is not a significant inhibitor of the medium chain dehydrogenase and does not form a detectable flavin adduct. However, the S-isomer is rapidly isomerized to the trans-trans-2,4-conjugated diene. Protein modeling studies suggest that the S-enantiomer cannot approach close enough to the isoalloxazine ring to form a flavin adduct, but can be facilely reprotonated by the catalytic base. These studies show that truncation of CoA thioesters may allow the design of unexpectedly potent lipophilic inhibitors of fatty acid oxidation.

Four casein kinase I isoforms are differentially partitioned between nucleus and cytoplasm

The casein kinase I (CKI) family consists of at least seven vertebrate genes, some of which can be alternatively spliced. Previously, we have studied the four splice variants of the chicken CKIalpha gene. The four proteins differ only by the presence or absence of two peptides, a 28-amino-acid "L" insert in the catalytic domain and a 12-amino-acid "S" insert near the extreme C-terminus. Here cells were transfected with DNA encoding all four isoforms fused to the green fluorescent protein (GFP) and the localization of each protein was examined. We noted that the L insert includes the sequence PVGKRKR, which has the characteristics of a nuclear localization signal (NLS), and we show that the CKIalphaL and CKIalphaLS isoforms which contain this sequence are targeted to the nucleus, where a fraction becomes associated with nuclear speckles. In contrast the two isoforms lacking the L insert remain predominantly cytoplasmic. Mutation of the first lysine in the putative NLS to asparagine prevented the nuclear entry of GFP-CKIalphaL. Therefore different CKIalpha isoforms are targeted to different cellular compartments in a fashion modulated by alternate transcription and in these locations presumably phosphorylate and regulate different cellular substrates.