Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Kinetic Control of the Li0.9Mn1.6Ni0.4O4 Spinel Structure with Enhanced Electrochemical Performance

The development of more sustainable societies has become an urgent goal worldwide. Electrical batteries are currently seen as one of the most important energy storage technologies for the development of decarbonized societies. However, many lithium-ion battery manufacturers currently utilize cobalt, a toxic and hazardous mineral, in their batteries. Lithium-deficient manganese nickel oxide spinels are considered promising candidates owing to their high potential and environmental friendliness. Their electrochemical performance highly depends on their average and local structures, such as phase purities, lattice parameters, and cation sites. Thus, a synthesis protocol should be designed to control these structural parameters to improve their electrochemical performance. In this study, we controlled the average and local structures of Li_0.9Mn_1.6Ni_0.4O₄ spinels obtained by co-precipitation by optimizing their cooling rates. High-resolution techniques, including transmission electron microscopy, synchrotron X-ray diffraction, and Auger-composition analysis combined with density functional theory calculations, X-ray absorption spectroscopy, and electrochemical analysis, were used to understand the average and local structural variations and their effects on the electrochemical properties. As a result, the control of oxygen diffusion at different cooling rates can promote the rearrangement of the structure, resulting in a cation-disordered spinel with minimal variations in lattice parameters and composition. Excellent electrochemical properties were noted in the cation-disordered spinel with high crystallinity and a slightly oxygen-rich surface produced via optimized cooling rates.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

An anatomical hypothesis: a "concentric-structured model" for the theoretical understanding of the surgical anatomy in the upper mediastinum required for esophagectomy with radical mediastinal lymph node dissection

Understanding the surgical anatomy is the key to reducing surgical invasiveness especially in the upper mediastinal dissection for esophageal cancer, which is supposed to have a significant impact on curability and morbidity. However, there is no theoretical recognition regarding the surgical anatomy required for esophagectomy, although the surgical anatomy in abdominal digestive surgery has been developed on the basis of embryological findings of intestinal rotation and fusion fascia. Therefore, we developed a hypothesis of a 'concentric-structured model' of the surgical anatomy in the upper mediastinum based on human embryonic development. This model was characterized by three factors: (1) a concentric and symmetric three-layer structure, (2) bilateral vascular distribution, and (3) an 'inter-layer potential space' composed of loose connective tissue. The concentric three-layer structure consists of the 'visceral layer', the 'vascular layer', and the 'parietal layer': the visceral layer containing the esophagus, trachea, and recurrent laryngeal nerves as the central core, the vascular layer of major blood vessels surrounding the visceral core to maintain the circulation, and the parietal layer as the outer frame of the body. The bilateral vascular distribution consists of the inferior thyroid arteries and bronchial arteries originating from the bilateral dorsal aortae in an embryo. This bilateral vascular distribution may be related to the formation of the proper mesentery of the esophagus and frequent lymph node metastasis observed in the visceral layer around recurrent laryngeal nerves. The three concentric layers are bordered by loose connective tissue called the 'inter-layer potential space'. This inter-layer potential space is the fundamental factor of our concentric-structured model as the appropriate surgical plane of dissection. The peripheral blood vessels, nerves, and lymphatics transition between each layer, thereby penetrating this loose connective tissue forming the inter-layer potential space. Recurrent laryngeal nerves also transition from the vascular layer after branching off from the vagal nerves and then ascend consistently in the visceral layer. We investigated the validity of this concentric-structured model, confirming the intraoperative images and the surgical outcomes of thoracoscopic esophagectomy in a prone position (TSEP) before and after the introduction of this hypothetical anatomy model. A total of 226 patients with esophageal cancer underwent TSEP from January 2015 to December 2016. After the introduction of this model, the surgical outcomes in 105 patients clearly improved for the operation time of the thoracoscopic procedure (160 min vs. 182 min, P = 0.01) and the incidence of recurrent laryngeal nerve palsy (19.0% vs. 36.4%, P = 0.004). Moreover, we were able to identify the concentric and symmetric layer structure through surgical dissection along the inter-layer potential space between the visceral and vascular layers ('viscero-vascular space') in all 105 cases after introduction of the hypothetical model. The concentric-structured model based on embryonic development is clinically beneficial for achieving less-invasive esophagectomy by ensuring a theoretical understanding of the surgical anatomy in the upper mediastinum.

Effect of Te substitution on crystal structure and transport properties of AgBiSe2thermoelectric material

Reduced lattice thermal conductivity of Te-substituted AgBiSe₂was qualitatively described using the point defect scattering model.

Adsorption efficiency of natural materials for low-concentration cesium in solution

In this study, several natural materials were investigated in order to clarify their potential use as cesium (Cs) adsorbents in situ. Four materials--carbonized rice hull, beech sawdust, oak sawdust, and charcoal (Japanese cedar)--which were previously shown to have Cs adsorption capabilities, were examined. Cs adsorption experiments were conducted using different initial Cs and adsorbent concentrations. The physical properties, adsorption isotherms, and adsorption processes were then examined, so as to exploit the Cs adsorption characteristics in the field. Based on these findings, carbonized rice hull and beech sawdust were selected as effective Cs adsorbents. It was found that these materials show continuous and stable Cs adsorption rates for different initial Cs concentrations. The adsorption efficiency of these two adsorption materials in combination was considered, and it was shown that the adsorption isotherms for carbonized rice hull and beech sawdust follow the Freundlich model. Furthermore, the beech sawdust adsorption process exhibited better agreement with the calculated values obtained via the adsorption rate model and the adsorption kinetics model than did the carbonized rice hull adsorption.

Gasless laparoscopically assisted myomectomy using a wound retraction system

INTRODUCTION

The purpose of this study was to elucidate the feasibility of gasless laparoscopically assisted myomectomy (LAM) using a wound retraction system. This method treats symptomatic uterine myomas by combining laparoscopy with a mini-laparotomy to enucleate myoma nodules and to close the uterine myometrium.

METHODS

This study includes 275 patients who underwent gasless LAM. For patients with fewer than three myoma nodules, the location of the largest nodule was classified as anterior, fundal, or posterior. The operative outcomes, intraoperative and postoperative courses, and complications were examined.

RESULTS

All operations were performed satisfactorily, and no conversions to laparotomy were required. None of the patients developed serious complications. The mean blood loss and operating time were 190.3 mL and 152.2 minutes, respectively. The mean myoma size was 8.9 cm, and the mean number of myomas per patient was 2.8. The average postoperative hospital stay was 5.7 days. There were no significant differences in resected myoma size, blood loss, and surgical duration with respect to the location of the largest nodule.

CONCLUSION

Gasless LAM with a wound retractor is feasible and allows surgeons to perform myomectomy safely and cost-effectively, without requiring advanced laparoscopic surgical skills and while maintaining minimum invasiveness.

Doxorubicin, cisplatin, and fluorouracil combination therapy for metastatic esophageal squamous cell carcinoma

The chemotherapy regimen currently used for treating esophageal and gastric carcinoma has been either epirubicin, cisplatin, and fluorouracil (5-FU) or docetaxel, cisplatin, and 5-FU. Here, we report the efficacy and toxicity of doxorubicin, cisplatin, and 5-FU for only esophageal squamous cell carcinoma (ESCC). Between January 2000 and October 2008, a total of 41 ESCC patients with a distant metastasis were enrolled. The most common sites of metastasis were liver (26, 63.4%), lung (9, 22.0%), and bone (8, 19.5%). Doxorubicin was administered on day 1 at 30 mg/m(2) , cisplatin on days 1-5 at 14 mg/m(2)/day, and 5-FU on days 1-5 at 700 mg/m(2)/day. The median number of cycles was 2.0 (range 1-8). The dose intensities of doxorubicin, cisplatin, and 5-FU were 92.9, 92.4, and 92.5%, respectively. The overall response rate was 43.9%; one showed complete response, 17 showed partial response, 13 showed a stable disease, and 10 showed progressive disease (PD). The median survival time was 306 days (95% CI = 74-935) and the 1-year survival rate was 37.6%. Grade 3 neutropenia was seen in seven patients and grade 4 in one patient. Grade 3 fatigue, anorexia, mucositis, and diarrhea were observed in three, two, two, and one patient, respectively. This regimen is effective as a first-line therapy for ESCC with distant metastasis.

AICAR and metformin, but not exercise, increase muscle glucose transport through AMPK-, ERK-, and PDK1-dependent activation of atypical PKC

Activators of 5'-AMP-activated protein kinase (AMPK) 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR), metformin, and exercise activate atypical protein kinase C (aPKC) and ERK and stimulate glucose transport in muscle by uncertain mechanisms. Here, in cultured L6 myotubes: AICAR- and metformin-induced activation of AMPK was required for activation of aPKC and ERK; aPKC activation involved and required phosphoinositide-dependent kinase 1 (PDK1) phosphorylation of Thr410-PKC-zeta; aPKC Thr410 phosphorylation and activation also required MEK1-dependent ERK; and glucose transport effects of AICAR and metformin were inhibited by expression of dominant-negative AMPK, kinase-inactive PDK1, MEK1 inhibitors, kinase-inactive PKC-zeta, and RNA interference (RNAi)-mediated knockdown of PKC-zeta. In mice, muscle-specific aPKC (PKC-lambda) depletion by conditional gene targeting impaired AICAR-stimulated glucose disposal and stimulatory effects of both AICAR and metformin on 2-deoxyglucose/glucose uptake in muscle in vivo and AICAR stimulation of 2-[(3)H]deoxyglucose uptake in isolated extensor digitorum longus muscle; however, AMPK activation was unimpaired. In marked contrast to AICAR and metformin, treadmill exercise-induced stimulation of 2-deoxyglucose/glucose uptake was not inhibited in aPKC-knockout mice. Finally, in intact rodents, AICAR and metformin activated aPKC in muscle, but not in liver, despite activating AMPK in both tissues. The findings demonstrate that in muscle AICAR and metformin activate aPKC via sequential activation of AMPK, ERK, and PDK1 and the AMPK/ERK/PDK1/aPKC pathway is required for metformin- and AICAR-stimulated increases in glucose transport. On the other hand, although aPKC is activated by treadmill exercise, this activation is not required for exercise-induced increases in glucose transport, and therefore may be a redundant mechanism.

Role of atypical protein kinase C in activation of sterol regulatory element binding protein-1c and nuclear factor kappa B (NFkappaB) in liver of rodents used as a model of diabetes, and relationships to hyperlipidaemia and insulin resistance

AIMS/HYPOTHESIS

Previous findings in rodents used as a model of diabetes suggest that insulin activation of atypical protein kinase C (aPKC) is impaired in muscle, but, unexpectedly, conserved in liver, despite impaired hepatic protein kinase B (PKB/Akt) activation. Moreover, aPKC at least partly regulates two major transactivators: (1) hepatic sterol receptor binding protein-1c (SREBP-1c), which controls lipid synthesis; and (2) nuclear factor kappa B (NFkappaB), which promotes inflammation and systemic insulin resistance.

METHODS

In Goto-Kakizaki rats used as a model of type 2 diabetes, we examined: (1) whether differences in hepatic aPKC and PKB activation reflect differences in activation of IRS-1- and IRS-2-dependent phosphatidylinositol 3-kinase (PI3K); (2) whether hepatic SREBP-1c and NFkappaB are excessively activated by aPKC; and (3) metabolic consequences of excessive activation of hepatic aPKC, SREBP-1c and NFkappaB.

RESULTS

In liver, as well as in muscle, IRS-2/PI3K activation by insulin was intact, whereas IRS-1/PI3K activation by insulin was impaired. Moreover, hepatic IRS-2 is known to control hepatic aPKC during insulin activation. Against this background, selective inhibition of hepatic aPKC by adenoviral-mediated expression of mRNA encoding kinase-inactive aPKC or short hairpin RNA targeting Irs2 mRNA and partially depleting hepatic IRS-2 diminished hepatic SREBP-1c production and NFkappaB activities, concomitantly improving serum lipids and insulin signalling in muscle and liver. Similar improvements in SREBP-1c, NFkappaB and insulin signalling were seen in ob/ob mice following inhibition of hepatic aPKC.

CONCLUSIONS/INTERPRETATION

In diabetic rodent liver, diminished PKB activation may largely reflect impaired IRS-1/PI3K activation, while conserved aPKC activation reflects retained IRS-2/PI3K activity. Hepatic aPKC may also contribute importantly to excessive SREPB-1c and NFkappaB activities. Excessive hepatic aPKC-dependent activation of SREBP-1c and NFkappaB may contribute importantly to hyperlipidaemia and systemic insulin resistance.

Inhibitory effect of glyburide on thrombin-induced platelet aggregation and phosphoinositide metabolism in normal human platelets

We previously reported the effects of diet, sulphonylureas or insulin on thrombin-induced platelet aggregation, phosphoinositide metabolism and protein phosphorylation in non-insulin-dependent diabetes mellitus (NIDDM) patients. To clarify the mechanism of glyburide and insulin on platelet function, here we studied the in vitro effects of glyburide and insulin on thrombin-induced metabolic changes using normal human platelets. Platelet aggregation stimulated with <0.5 U/ml thrombin, 0.75-3 microM adenosine diphosphate (ADP) or 1 microg/ml collagen was significantly lower in glyburide-treated platelets, but not in insulin-treated platelets, than in untreated ones (control). Thrombin-induced incorporation of 32P radioactivity into phosphatidic acid (PA) in glyburide-treated platelets was lower than that in control but not in insulin-treated platelets. Phosphorylated proteins of platelets induced by thrombin and 12- O -tetradecanoylphorbol 13-acetate (TPA) in glyburide-treated platelets were suppressed, but not in insulin-treated platelets, compared with control. These results suggest that glyburide induces suppression of thrombin-induced activation of phospholipase C, which mediates hydrolysis of PIP and PIP(2) and production of PA, and subsequently inhibits platelet aggregation.

Surface discharge of heavy metals from low farmland

Runoff heavy metals from farmland were examined using the field data for the summer of 2005. The observation farmland is located on lowland where the irrigation water was contaminated with the drained water from the upstream farmlands. The area of the farmland is 11.2 ha, of which 6.0 ha and 4.5 ha have been used for rice paddy fields and soybean cultivation, respectively. During the observation, heavy metal concentrations at the downstream end were usually found to be higher than those in the irrigation water. That is, the heavy metal concentrations increased due to the passage of the water through the farmland. This increase in the heavy metal concentrations is not equal to the discharge of the heavy metal because the evaporation on the surface of the paddy field and the absorption by plants makes the surface water volume small. The discharged load from the farmland generally indicates the gross surface load from the farmland. When the effects of circulation irrigation on the heavy metal concentrations are estimated, the discharged load from the farmland should be calculated as the net surface load. When the runoff heavy metals from the circulation irrigation farmland are estimated, it is important to consider the inflowing heavy metals with irrigation water. All the heavy metal types observed in this study were discharged from the farmland. The net surface loads of Cr, Fe, Cd, and Pb were 371 microg m(-2) day(-1), 14.9 mg m(-2) day(-1), 0.26 microg m(-2) day(-1), and 3.3 microm( -2) day(-1), respectively.

Metformin improves atypical protein kinase C activation by insulin and phosphatidylinositol-3,4,5-(PO4)3 in muscle of diabetic subjects

AIMS/HYPOTHESIS

Metformin is widely used for treating type 2 diabetes mellitus, but its actions are poorly understood. In addition to diminishing hepatic glucose output, metformin, in muscle, activates 5'-AMP-activated protein kinase (AMPK), which alone increases glucose uptake and glycolysis, diminishes lipid synthesis, and increases oxidation of fatty acids. Moreover, such lipid effects may improve insulin sensitivity and insulin-stimulated glucose uptake. Nevertheless, the effects of metformin on insulin-sensitive signalling factors in human muscle have only been partly characterised to date. Interestingly, other substances that activate AMPK, e.g., aminoimidazole-4-carboxamide-1-beta-D: -riboside (AICAR), simultaneously activate atypical protein kinase C (aPKC), which appears to be required for the glucose transport effects of AICAR and insulin.

METHODS

Since aPKC activation is defective in type 2 diabetes, we evaluated effects of metformin therapy on aPKC activity in muscles of diabetic subjects during hyperinsulinaemic-euglycaemic clamp studies.

RESULTS

After metformin therapy for 1 month, basal aPKC activity increased in muscle, with little or no change in insulin-stimulated aPKC activity. Metformin therapy for 8 to 12 months improved insulin-stimulated, as well as basal aPKC activity in muscle. In contrast, IRS-1-dependent phosphatidylinositol (PI) 3-kinase activity and Ser473 phosphorylation of protein kinase B were not altered by metformin therapy, whereas the responsiveness of muscle aPKC to PI-3,4,5-(PO(4))(3), the lipid product of PI 3-kinase, was improved.

CONCLUSIONS/INTERPRETATION

These findings suggest that the activation of AMPK by metformin is accompanied by increases in aPKC activity and responsiveness in skeletal muscle, which may contribute to the therapeutic effects of metformin.

The polymorphism interleukin 8 -251 A/T influences the susceptibility of Helicobacter pylori related gastric diseases in the Japanese population

BACKGROUND

Helicobacter pylori infection is associated with variable clinical outcomes, including gastroduodenal diseases, and genetic factors may be relevant in this process.

AIMS

We investigated the effects of an interleukin 8 (IL-8) gene polymorphism on the risk of gastroduodenal diseases, the degree of H pylori induced gastritis, and IL-8 gene transcription.

SUBJECTS

The study was performed in 244 healthy control subjects and 690 H pylori positive patients with non-cardia gastric cancer, gastric ulcer, duodenal ulcer, or gastritis.

METHODS

We identified the IL-8 -251 A/T polymorphism by direct sequence analysis, and measured the gastritis score and serum pepsinogen (PG). The transcriptional promoter activity of the IL-8 gene was assessed by luciferase assay.

RESULTS

IL-8 -251A was associated with a higher risk of gastric cancer and gastric ulcer. Patients carrying IL-8 -251A showed an increased risk of gastric cancer (odds ratios (OR) 2.01 (95% confidence interval (CI) 1.38-2.92)) and gastric ulcer (OR 2.07 (95% CI 1.37-3.12)). Compared with patients younger than 49 years, atrophy and metaplasia scores in the antrum were significantly higher and the PG I/II ratio significantly lower in -251A carriers than in T/T carriers. In the in vitro assay, IL-8 -251A showed enhanced promoter activity in response to IL-1beta or tumour necrosis factor alpha.

CONCLUSIONS

The IL-8 -251A allele may be associated with progression of gastric atrophy in patients with H pylori infection, and may increase the risk of gastric cancer and gastric ulcer in Japanese people.

ProNectin F-grafted-ethylene vinyl alcohol copolymer (EVAL) as a liquid type material for treating cerebral aneurysm—An in vivo and in vitro study

The authors aimed to develop a liquid material for embolization of aneurysms. In vitro and in vivo performances of the new embolic material were examined by cell culture and using an aneurysm model made in common carotid arteries (CCAs) of adult rats. Engineered protein ProNectin F (PnF), which contains 13 sites of an arginine-glycine-aspartic acid (RGD), was grafted onto ethylene vinyl alcohol copolymer (EVAL-g-PnF). The liquid material, EVAL-g-PnF dissolved in DMSO, was infused into an aneurysm model. The blood segments were harvested 2, 5, and 14 days and examined histologically. A number of bovine coronary artery endothelial cells became able to attach to and form cobblestone-like islands on the EVAL by incorporating PnF. The aneurysm model infused with the EVAL-g-PnF solution revealed that the aneurysm lumen was filled with proliferated fibroblasts and macrophages. On the other hand, the aneurysm model treated with unmodified EVAL showed that the cavity was almost filled with EVAL mass and that fibroblasts and macrophages filled a narrow space between the EVAL mass and the cavity wall. The results indicate that EVAL-g-PnF could be more suitable for reorganizing the cavity of an aneurysm than native EVAL.

Impaired activation of protein kinase C-zeta by insulin and phosphatidylinositol-3,4,5-(PO4)3 in cultured preadipocyte-derived adipocytes and myotubes of obese subjects

Insulin resistance in obesity is partly due to diminished glucose transport in myocytes and adipocytes, but underlying mechanisms are uncertain. Insulin-stimulated glucose transport requires activation of phosphatidylinositol (PI) 3-kinase (3K), operating downstream of insulin receptor substrate-1. PI3K stimulates glucose transport through increases in PI-3,4,5-(PO(4))(3) (PIP(3)), which activates atypical protein kinase C (aPKC) and protein kinase B (PKB/Akt). However, previous studies suggest that activation of aPKC, but not PKB, is impaired in intact muscles and cultured myocytes of obese subjects. Presently, we examined insulin activation of glucose transport and signaling factors in cultured adipocytes derived from preadipocytes harvested during elective liposuction in lean and obese women. Relative to adipocytes of lean women, insulin-stimulated [(3)H]2-deoxyglucose uptake and activation of insulin receptor substrate-1/PI3K and aPKCs, but not PKB, were diminished in adipocytes of obese women. Additionally, the direct activation of aPKCs by PIP(3) in vitro was diminished in aPKCs isolated from adipocytes of obese women. Similar impairment in aPKC activation by PIP(3) was observed in cultured myocytes of obese glucose-intolerant subjects. These findings suggest the presence of defects in PI3K and aPKC activation that persist in cultured cells and limit insulin-stimulated glucose transport in adipocytes and myocytes of obese subjects.

Genomic localization of endogenous mobile CACTA family transposons in natural variants of Arabidopsis thaliana

The differentiation between gene-rich and transposon-rich (gene-poor) regions is a common feature of plant genomes. This may be due to preferential integration of transposons into gene-poor regions or may be due to purifying selection against transposon insertion into gene-rich regions. We examined the distribution of a low-copy-number mobile subfamily of Arabidopsis CACTA transposons in the genomes of 19 natural variants (ecotypes) of A. thaliana, and compared that to the pattern of integrations induced in the laboratory by mutation of the DDM1 (Decrease in DNA Methylation) gene. Sequences similar to mobile CACTA1 copies were distributed among the ecotypes and showed high degrees of polymorphism in genomic localization. Despite the high level of polymorphism, the copy number was low in all the ecotypes examined, and the elements were localized preferentially in pericentromeric and transposon-rich regions. This contrasts with the pattern of transposition induced by the ddm1 mutation, in which the range of integration sites is less biased and the copy number frequently increases. Based on these observations, we discuss the possible contribution of natural selection and chromatin structure to the distribution of transposons.

T130I mutation in HNF-4alpha gene is a loss-of-function mutation in hepatocytes and is associated with late-onset Type 2 diabetes mellitus in Japanese subjects

AIMS/HYPOTHESIS

Mutations in hepatocyte nuclear factor (HNF)-4alpha gene cause a form of maturity-onset diabetes of the young (MODY1). The T130I mutation is a rare missense mutation, which affects a conserved amino acid in a DNA binding domain. This mutation can be found in the general population, so this variant alone does not cause MODY. However, its significance in the development of late-onset Type 2 diabetes is not known.

METHODS

We screened 423 unrelated Japanese patients with late-onset Type 2 diabetes and 354 unrelated non-diabetic control subjects for the T130I mutation in the HNF-4alpha gene. The transactivation ability of T130I-HNF-4alpha was assessed using reporter gene assay.

RESULTS

The frequency of the T130I mutation was higher in Type 2 diabetic patients ( p=0.015, odds ratio 4.3, 95%CI 1.24-14.98) than control subjects. The serum HDL-cholesterol concentration was lower in Type 2 diabetic patients with the T130I mutation compared with those without this mutation ( p=0.006). Reporter gene analysis showed that T130I-HNF-4alpha transcriptional activity was not impaired compared with wild-type HNF-4alpha in Hela and MIN6 cells, but it was reduced in HepG2 and primary cultured mouse hepatocytes (27-78% of wild type, p<0.05).

CONCLUSION/INTERPRETATION

Our findings suggest that T130I-HNF-4alpha is a loss-of-function mutation in hepatocytes and that this mutation is associated with late-onset Type 2 diabetes in Japanese subjects. The T130I mutation in the HNF-4alpha gene might be involved in the development of Type 2 diabetes in the Japanese population.

Serum adenosine deaminase activity and its isoenzyme pattern in women with normal pregnancies

Adenosine deaminase (ADA) is a purine enzyme which is essential for the proliferation, maturation and function of lymphoid cells, and congenital deficiency of this enzyme is associated with severe combined immunodeficiency disease. The activity of ADA has changed in diseases characterized by the alteration of cell-mediated immunity such as rheumatoid arthritis, systemic lupus erythematosus and tuberculosis, so ADA has been considered as a nonspecific marker of cell-mediated immunity. In this study we examined changes in serum total ADA activity and the patterns of two ADA isoenzymes, ADA1 and ADA2 in normal pregnant women, and evaluated the possible role of the alteration of cell-mediated immunity during normal pregnancy as causes of changes in ADA activity. We measured serum activities of total ADA, ADA1 and ADA2 in normal pregnant women in the third trimester (n=24) and age-matched healthy nonpregnant women (n=24). Peripheral blood lymphocytes and monocytes were also measured. In normal pregnant women, serum total ADA activity averaged 10.5 +/- 0.5 U/L, which was significantly lower than in nonpregnant women (14.0 +/- 0.5 U/L ) (p<0.05), and mean serum ADA2 activity also significantly reduced that of nonpregnant women (p<0.05). There was no significant difference in ADA1 activity in normal pregnant and nonpregnant women. The decrease in total ADA activity was accompanied by the decrease in lymphocyte count. These results suggest that reduced serum total ADA activity reflects decrease in ADA2 activity, and which may be in part associated with depressed cell-mediated immunity during normal pregnancy.

Changes in the proportion of T helper 1 and T helper 2 cells in cord blood after premature rupture of membranes

This study investigated changes in the proportion of T helper (Th)1 and Th2 cells in cord blood after premature rupture of membranes (PROM), and evaluate the effects of PROM on the intrauterine fetal immune status. The proportion of CD3-positive T cells secreting interferon (IFN)-gamma as an index of Th1 cells, and interleukin (IL)-4 as an index of Th2 cells in cord blood of 12 newborns with and without PROM, were analyzed by flow cytometry. In cord blood of newborns with PROM, the proportion of IFN-gamma secreting cells significantly increased, and the proportion of IL-4 secreting cells was rather high but not significantly higher than that of newborns without PROM. These changes eventually caused a shift in the Th1/Th2 ratio to Th1 dominance in PROM. There was no significant correlation between the proportion of IFN-gamma secreting cells and the duration of PROM before the onset of labor. These results suggest that the increase in the proportion of IFN-gamma secreting cells after PROM, which eventually cause the Th1/Th2 ratios to show the Th1 predominance, may reflect in part intrauterine fetal immune responses to PROM.

Hybrid cyst: case reports and review of 15 cases in Japan

Hybrid cyst is a rare cystic lesion that includes more than two components of the pilosebaceous units. To clarify the clinical and pathological features of hybrid cysts, we report two cases and review 15 cases of hybrid cyst in Japan. On the whole, the age range was 12-73 years with a 2.95:1 female predominance and predilection for the scalp and face (46.7%). Most of the tumours presented as a solitary lesion and the size range was 2-45 mm. The most frequent histological type was the combination of infundibular and trichilemmal cysts (60.0%). Studying the clinicopathological features of hybrid cysts helps us in understanding the pathogenesis of diseases arising from pilosebaceous units.

Implications from and for food cultures for cardiovascular diseases: Japanese food, particularly Okinawan diets

Okinawans, who have a different ethnicity and food cultural history to other Japanese nationals, and an exceptional longevity have been studied at home and as migrant groups in Hawaii and Brazil. Biomarkers for fish and soy intake and intervention studies indicate that these foods, along with seaweed and green vegetables are candidates for chronic non-communicable disease prevention.

Laser cooling of calcium ions by use of ultraviolet laser diodes: significant induction of electron-shelving transitions

Calcium ions are laser cooled in a Paul trap by use of a grating-stabilized UV laser diode. Unusual quantum jumps or fluctuations in the fluorescence signal are observed without application of any shelving lasers. It has become clear that such phenomena can be ascribed to shelving transitions induced by background 393-nm spontaneous photons emitted from the laser medium. Shelving transitions are suppressed by use of an interference filter, and the ions are successfully cooled to crystallization temperature with sufficient reproducibility.

[Late phase II clinical study of amrubicin hydrochloride, a novel synthetic anthracycline derivative anticancer agent, for malignant lymphoma]

A late phase II clinical trial of amrubicin hydrochloride, a novel synthetic anthracycline derivative anticancer agent, was conducted at 14 institutions nationwide, in patients with non-Hodgkin's lymphoma. In this multi-center collaborative study, doxorubicin hydrochloride was replaced by amrubicin hydrochloride in CHOP therapy, a standard regimen for non-Hodgkin's lymphoma consisting of cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate and prednisolone. A total of 39 patients were enrolled in this study between January 1996 and March 1998. Among them, 37 patients were eligible for this study. The study drugs were administered to patients with non-Hodgkin's lymphoma according to the following schedule: amrubicin hydrochloride (100 mg/m2, body surface area), cyclophosphamide (750 mg/m2) and vincristine sulfate (1.4 mg/m2, a maximal dose of 2.0 mg/body) were administered intravenously on day one, while prednisolone (60 mg/m2/day) was administered orally on days 1 to 5. This cycle of treatment was repeated every three weeks in principle. The efficacy and safety were assessed for 37 eligible patients. The combined rate for CR + CRu was 70.3% (26/37) and the overall response rate (CR + CRu + PR) was 86.5% (32/37). demonstrating that amrubicin hydrochloride was very effective in the treatment of non-Hodgkin's lymphoma. The most frequent adverse reactions that occurred during the study were myelosuppressions: leukopenia and neutropenia, 100% (37/37); and decreases in hemoglobin levels, 81.1% (30/37). Thrombocytopenia, elevations of serum GOT and GPT levels, anorexia, nausea/vomitting, fever, stomatitis and alopecia were also observed. Although leukopenia and neutropenia of grade 3 or higher were noted in 89.2% (33/37) and 94.6% (35/37), respectively, they were controllable by administrations of G-CSF or solely by follow-up observations. One patient developed intestinal paralysis (grade 4) and another developed hematemesis. In conclusion, these results indicate that amrubicin hydrochloride is an effective agent as a component of combination chemotherapy for non-Hodgkin's lymphoma.

Excitatory synaptic currents in lumbosacral parasympathetic preganglionic neurons elicited from the lateral funiculus

Excitatory postsynaptic currents (EPSCs) in parasympathetic preganglionic neurons (PGNs) were examined using the whole cell patch-clamp recording technique in L6 and S1 spinal cord slices from neonatal rats (6-16 days old). PGNs were identified by labeling with retrograde axonal transport of a fluorescent dye (Fast Blue) injected into the intraperitoneal space 3-7 days before the experiment. Synaptic responses were evoked in PGNs by field stimulation of the lateral funiculus (LF) in the presence of bicuculline methiodide (10 microM) and strychnine (1 microM). In approximately 40% of the cells (total, 100), single-shock electrical stimulation of the LF elicited short, relatively constant latency [3.0 +/- 0.1 (SE) ms] fast EPSCs consistent with a monosynaptic pathway. The remainder of the cells did not respond to stimulation. At low intensities of stimulation, the EPSCs often occurred in an all-or-none manner, indicating that they were mediated by a single axonal input. Most cells (n = 33) exhibited only fast EPSCs (type 1), but some cells (n = 8) had fast EPSCs with longer, more variable latency polysynaptic EPSCs superimposed on a slow inward current (type 2). Type 1 fast synaptic EPSCs were pharmacologically dissected into two components: a transient component that was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 5 microM), a non-NMDA glutamatergic antagonist, and a slow decaying component that was blocked by 2-amino-5-phosphonovalerate (APV, 50 microM), a NMDA antagonist. Type 2 polysynaptic currents were reduced by 5 microM CNQX and completely blocked by combined application of 5 microM CNQX and 50 microM APV. The fast monosynaptic component of type 1 EPSCs had a linear current-voltage relationship and reversed at a membrane potential of 5.0 +/- 5.9 mV (n = 5), whereas the slow component exhibited a negative slope conductance at holding potentials greater than -20 mV. The type 1, fast synaptic EPSCs had a time to peak of 1.4 +/- 0.1 ms and exhibited a biexponential decay (time constants, 5.7 +/- 0.6 and 38.8 +/- 4.0 ms). In the majority of PGNs (n = 11 of 15 cells), EPSCs evoked by electrical stimulation of LF exhibited paired-pulse inhibition (range; 25-33% depression) at interstimulus intervals ranging from 50 to 120 ms. These results indicate that PGNs receive monosynaptic and polysynaptic glutamatergic excitatory inputs from axons in the lateral funiculus.

Identification of base substitutions in ten types of rare variants of phosphoglucomutase-1 (PGM1) encountered in Japanese

In a previous starch-gel electrophoresis study of erythrocyte phosphoglucomutase-1 (PGM1) in 23,095 Japanese from Hiroshima and Nagasaki, we detected 14 types of rare variant alleles. To determine sequence differences in these rare alleles, cell lines were established from peripheral B-lymphocytes from 24 unrelated individuals in whom nine types of rare variants are presumed to exist on the basis of earlier electrophoresis studies. cDNAs reverse transcribed from mRNAs extracted from these cell lines were amplified by polymerase chain reaction and sequences determined. Amino acid substitution types were deduced from each cDNA sequence. Although two individuals were reported to have an identical electromorph (PGM1 4HR3), sequence analysis revealed that alleles encoding these electromorphs possessed different base substitutions, and one was renamed PGM1 4HR4. As the amino acid substitution of ten different variants could be deduced by cDNA sequence in this study, the effect of each amino acid substitution on enzyme activity could be precisely simulated. The secondary structure of each variant predicted by computer simulations revealed that very decreased activity observed on PGM1 4HR2 protein was caused by significant secondary structure change introduced by the amino acid substitution. On the basis of the crystal structure, the amino acid substitutions of the ten types of rare variants seem to be outside the active center of this enzyme.

Dehydroepiandrosterone (DHEA) stimulates glucose uptake in rat adipocytes: activation of phospholipase D

We examined the effect of dehydroepiandrosterone (DHEA) on glucose uptake and phospholipase D (PLD) activation in rat adipocytes. DHEA (1 microM) provoked a twofold increase in [3H]2-deoxyglucose (DG) uptake for 30 min. Incorporation of [3H]glycerol into diacylglycerol was increased 150% above basal level for 20 min after stimulation with 1 microM DHEA. DHEA increased PLD activity, measured by the incorporation into [3H]phosphatidylethanol in [3H]palmitate labelled rat adipocytes, or by [3H]choline release in [methyl-(3)H]choline labeled rat adipocytes. Our results suggest that DHEA stimulates glucose uptake with activation of PLD in rat adipocytes.

Involvement of c-Src in carcinoma cell motility and metastasis

Carcinoma cells exhibit dysfunction / dysregulation of cell adhesion systems that correlates with their abilities to migrate, invade, and metastasize. Here we show that the tyrosine kinase c-Src is required for motility and metastasis of two carcinoma cell lines. Adherent KYN-2 cells having a high level of c-Src kinase activity become scattered, extend lamellipodia, and exhibit high motility. Expression of a dominant-negative mutant form of c-Src caused formation of stress fibers and focal adhesions, and markedly reduced motility. HCT15 cells extended lamellipodia and became scattered in response to lysophosphatidic acid stimulation in parallel with transient activation of c-Src, which was inhibited by expression of a dominant-negative mutant form of c-Src or treatment with a specific Src kinase inhibitor. Furthermore, implantation of dominant-negative c-Src transfectants into the peritoneal cavity of SCID mice resulted in reduced peritoneal dissemination compared with control transfectants. These findings indicate that c-Src activation is critically involved in carcinoma cell migration and metastasis.

Increased platelet aggregation in diabetic patients with microangiopathy despite good glycemic control

The pathogenesis of diabetic micro- and macroangiopathy cannot be fully explained by hyperglycemia alone. To clarify diabetic complications mediated by increased platelet activity, we have studied platelet aggregation and its second messenger molecules such as protein kinase C (PKC), RhoA, and phosphatidylinositol 3-kinase (PI3- kinase), in six diabetic patients with diabetic retinopathy and other diabetic complications in spite of good glycemic control. Their HbA(1c) levels throughout the observation period had been less than 6% with diet treatment alone, despite which diabetic retinopathy developed to the pre-proliferative stage during 2-8 years observation. Low-dose thrombin (< 0.5 U/ml)-stimulated platelet aggregation in the diabetic patients was enormously elevated compared with healthy control subjects. PKC, RhoA and PI3-kinase activities in the cytosol- and membrane-associated fractions were examined in the platelets from the two patients (Cases 2 and 4). Platelet membrane-associated RhoA and PI3-kinase activity in Case 2 were increased before the stimulation. Platelet RhoA and PI 3-kinase activities in Case 4 were increased after the stimulation with low-dose thrombin (0.01 U/ml). Membrane-associated immunoreactive PKC alpha, but not PKC beta in Cases 2 and 4 was elevated. Although platelet hyperactivity in these four patients was observed, PKC and RhoA in mononuclear leukocytes from these patients were not different from healthy subjects. Membrane-associated PKC alpha and RhoA immunoreactivities also increased in the other three cases. These results suggest that hyperreactivity of PKC alpha may lead to increased RhoA and PI3-kinase activities and platelet hyperfunction in diabetic patients with good glycemic control, and that raised platelet PKC alpha may be implicated in the pathogenesis of diabetic complications.

Distribution of twenty-four hour urinary taurine excretion and association with ischemic heart disease mortality in 24 populations of 16 countries: results from the WHO-CARDIAC study

There is considerable interest in the association between taurine (2-aminoethanesufonic acid) and risk of ischemic heart disease (IHD), but little information has been made available on the distribution of taurine in populations around the world. The present study aimed to describe the differences in taurine excretion levels and their associations with IHD mortality rates in 24 populations in 16 countries worldwide. This was a multicenter cross-sectional study. In each center, 100 men and 100 women aged 48-56 years were selected randomly from the local populations. Twenty-four hour urinary taurine excretion was measured using an amino acid analyzer (Hitachi 835, Ibaragi, Japan). Age-adjusted IHD mortality rates in the relevant populations were calculated using the direct standard method. The results indicated that (a) percentiles 25%, 50% and 75% of the distributions of 24-h taurine excretion showed large variations in the study populations. Median values of taurine ranged from 191.6 micromol/day (St John, Canada) to 2,180.6 micromol/day (Beppu, Japan) in males, and from 127.5 micromol/day (Moscow, Russia) to 1,590.0 micromol/day (Beppu, Japan) in females. The highest overall median value of taurine was found in the Japanese population samples, followed by the Chinese samples (Shanghai and Taiwan). European, North American and oceanic Caucasians, however, had much lower median values of taurine, except in the cases of the samples from France and Spain. (b) Median values of taurine were significantly associated negatively with age-adjusted IHD mortality rates across the 24 study population samples in men (R2=0.42, p<0.01), and in women (R2=0.55, p<0.01). These negative associations remained significant after adjustment for serum total cholesterol, body mass index and urinary sodium to potassium ratios. In conclusion, the study provides, for the first time, a cross-sectional database on distribution of 24-h urinary taurine excretion in 24 population samples worldwide. A strong and inverse association between population levels of taurine excretion and IHD mortality was observed.