Erythromycin inhibited glycinergic inputs to gastric vagal motoneurons in brainstem slices of newborn rats

BACKGROUND

Motilin has been known to stimulate the motility of digestive organs peripherally via activation of motilin receptors located at gastrointestinal (GI) cholinergic nerve endings and/or smooth muscle cells. Recent studies have indicated that motilin may also promote GI motility via actions in the central nervous system; however the sites of action and the mechanisms are not clear yet. The present study aimed to test the hypothesis that motilin receptor agonist erythromycin alters the synaptic inputs of preganglionic gastric vagal motoneurons (GVMs) located in the dorsal motor nucleus of the vagus (DMV).

METHODS

Gastric vagal motoneurons were retrogradely labeled by fluorescent tracer from the stomach wall of newborn rats. Fluorescently labeled GVMs in DMV were recorded using whole-cell patch-clamp in brainstem slices and the effects of motilin receptor agonist erythromycin on the synaptic inputs were examined.

KEY RESULTS

Erythromycin (100 nmol L(-1), 1 μmol L(-1), 10 μmol L(-1)) significantly inhibited the frequency of glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) of GVMs and significantly inhibited the amplitude at the concentration of 10 μmol L(-1). These responses were prevented by GM-109, a selective motilin receptor antagonist. In the pre-existence of tetradotoxin (TTX, 1 μmol L(-1)), erythromycin (10 μmol L(-1)) caused significant decreases of the glycinergic miniature inhibitory postsynaptic currents (mIPSCs), in both the frequency and the amplitude. However, erythromycin (10 μmol L(-1)) didn't cause significant changes of the GABAergic sIPSCs.

CONCLUSIONS & INFERENCES

Erythromycin selectively inhibits the glycinergic inputs of GVMs.

Trends in cancer mortality in the elderly in Japan, 1970-2007

OBJECTIVE

The primary objective of this study is to describe cancer mortality rates and trends among Japanese elderly aged 65-84 years for the period 1970-2007.

MATERIALS AND METHODS

Age-standardized mortality rates were calculated by the direct method using age-specific mortality rates at 5-year age intervals and weights based on the age distribution of the standard world population. The joinpoint regression model was used to describe changes in trends.

RESULTS

For all cancers combined, the mortality rate at age 65-84 years during 2000-2007 was 1145.13 (per 100,000 population) for men and 461.93 (per 100,000) for women. Mortality rates have declined in the past 10 years in both sexes. These favorable trends were driven largely by decreases in mortality for three leading cancers in the elderly men [lung, stomach and colorectal cancer (CRC)] and for two of the three most common cancers in the elderly women (stomach and CRC), combined with a leveling off of death rate from lung cancer in women.

CONCLUSION

The population-based data in the current study underscore the importance of cancer research and prevention for the older segment in Japan to reduce the additional cancer burden among the growing number of elderly persons.

Structural characterization by x-ray methods of novel antimicrobial gallium-doped phosphate-based glasses

Antimicrobial gallium-doped phosphate-based glasses of general composition (P(2)O(5))(0.45)(CaO)(0.16)(Na(2)O)(0.39-x)(Ga(2)O(3))(x) (where x=0, 0.01, 0.03, and 0.05) have been studied using the advanced synchrotron-based techniques of Ga K-edge x-ray absorption spectroscopy and high-energy x-ray diffraction to provide a structural insight into their unique properties. The results show that the Ga(3+) ions are octahedrally coordinated. Furthermore, substitution of Na(2)O by Ga(2)O(3) strengthens the phosphate network structure because the presence of GaO(6) octahedra inhibits the migration of the remaining Na(+) ions. The results are discussed in terms of the use of Na(2)O-CaO-P(2)O(5) glasses as controlled-delivery devices for antimicrobial Ga(3+) ions in biomedical applications. We are thereby able to relate the atomic-scale environment of the Ga(3+) ions beneficially to the glass dissolution, and thus to their ability to disrupt bacterial cell activity by usurping the role of iron.

A study of the formation of amorphous calcium phosphate and hydroxyapatite on melt quenched Bioglass using surface sensitive shallow angle X-ray diffraction

Melt quenched silicate glasses containing calcium, phosphorous and alkali metals have the ability to promote bone regeneration and to fuse to living bone. These glasses, including 45S5 Bioglass((R)) [(CaO)(26.9)(Na(2)O)(24.4)(SiO(2))(46.1)(P(2)O(5))(2.6)], are routinely used as clinical implants. Consequently there have been numerous studies on the structure of these glasses using conventional diffraction techniques. These studies have provided important information on the atomic structure of Bioglass((R)) but are of course intrinsically limited in the sense that they probe the bulk material and cannot be as sensitive to thin layers of near-surface dissolution/growth. The present study therefore uses surface sensitive shallow angle X-ray diffraction to study the formation of amorphous calcium phosphate and hydroxyapatite on Bioglass((R)) samples, pre-reacted in simulated body fluid (SBF). Unreacted Bioglass((R)) is dominated by a broad amorphous feature around 2.2 A(-1) which is characteristic of sodium calcium silicate glass. After reacting Bioglass((R)) in SBF a second broad amorphous feature evolves ~1.6 A(-1) which is attributed to amorphous calcium phosphate. This feature is evident for samples after only 4 h reacting in SBF and by 8 h the amorphous feature becomes comparable in magnitude to the background signal of the bulk Bioglass((R)). Bragg peaks characteristic of hydroxyapatite form after 1-3 days of reacting in SBF.

Trends in cancer mortality in Japanese adolescents and young adults aged 15-29 years, 1970-2006

OBJECTIVE

The primary objective of this study is to describe cancer mortality rates and trends among Japanese adolescents and young adults aged 15-29 years for the period 1970-2006.

MATERIALS AND METHODS

Age-standardized mortality rates were calculated by the direct method using age-specific mortality rates at 5-year age intervals and weights based on the age distribution of the standard world population. The joinpoint regression model was used to describe changes in trends.

RESULTS

For all cancers combined, the mortality rate at age 15-29 years during 2000-2006 was 4.41 (per 100,000 population) for males and 3.81 (per 100,000) for females. Trends of mortality from cancer in Japan were similar to that in other developed countries. A notable exception was cervical cancer, for which Japanese young women showed a significant increase, on average 4.0% per year throughout the period.

CONCLUSION

This report presents updated figures and trends in cancer mortality among adolescents and young adults aged 15-29 years in Japan and other developed countries. We hope this study will raise public awareness on cancer in this age group and provide the impetus for further research to improve the survival and quality of life of the young people in Japan.

Roles and regulation of membrane-associated serine proteases

Pericellular proteolytic activity affects many aspects of cellular behaviour, via mechanisms involving processing of the extracellular matrix, growth factors and receptors. The serine proteases have exquisitely sensitive regulatory mechanisms in this setting, involving both receptor-bound and transmembrane proteases. Receptor-bound proteases are exemplified by the uPA (urokinase plasminogen activator)/uPAR (uPAR receptor) plasminogen activation system. The mechanisms initiating the activity of this proteolytic system on the cell surface, a critical regulatory point, are poorly understood. We have found that the expression of the TTSP (type II transmembrane serine protease) matriptase is highly regulated in leucocytes, and correlates with the presence of active uPA on their surface. Using siRNA (small interfering RNA), we have demonstrated that matriptase specifically activates uPAR-associated pro-uPA. The uPA/uPAR system has been implicated in the activation of the plasminogen-related growth factor HGF (hepatocyte growth factor). However, we find no evidence for this, but instead that HGF can be activated by both matriptase and the related TTSP hepsin in purified systems. Hepsin is of particular interest, as the proteolytic cleavage sequence of HGF is an 'ideal substrate' for hepsin and membrane-associated hepsin activates HGF with high efficiency. Both of these TTSPs can be activated autocatalytically at the cell surface, an unusual mechanism among the serine proteases. Therefore these TTSPs have the capacity to be true upstream initiators of proteolytic activity with subsequent downstream effects on cell behaviour.

A comparative linkage map of oilseed rape and its use for QTL analysis of seed oil and erucic acid content

We have developed a new DH mapping population for oilseed rape, named TNDH, using genetically and phenotypically diverse parental lines. We used the population in the construction of a high stringency genetic linkage map, consisting of 277 loci, for use in quantitative genetic analysis. A proportion of the markers had been used previously in the construction of linkage maps for Brassica species, thus permitting the alignment of maps. The map includes 68 newly developed Sequence Tagged Site (STS) markers targeted to the homologues of defined genes of A. thaliana. The use of these markers permits the alignment of our linkage map with the A. thaliana genome sequence. An additional 74 loci (31 newly developed STS markers and 43 loci defined by SSR and RFLP markers that had previously been used in published linkage maps) were added to the map. These markers increased the resolution of alignment of the newly constructed linkage map with existing Brassica linkage maps and the A. thaliana genome sequence. We conducted field trials with the TNDH population at two sites, and over 2 years, and identified reproducible QTL for seed oil content and erucic acid content. The results provide new insights into the genetic control of seed oil and erucic acid content in oilseed rape, and demonstrate the utility of the linkage map and population.

Continuous cytomegalovirus seroconversion in a large group of healthy blood donors

BACKGROUND AND OBJECTIVES

Transmission of cytomegalovirus (CMV) to seronegative, immunocompromised recipients can cause serious and fatal complications. Although the seroprevalence of CMV is high, the risk of primary CMV infection among healthy blood donors has not yet been analysed in a large population.

MATERIALS AND METHODS

We developed an algorithm to determine the rate of CMV seroconversion in an overall cohort of 24,260 subjects who donated 176,474 blood units during an 11-year observation period.

RESULTS

We detected CMV seroconversion in all relevant age groups (18-60 years) with an overall seroconversion rate of 0.55% per year. Both CMV seroconversion and seroprevalence occurred more frequently in female donors (P = 0.02 and P < 0.001, respectively). We identified 30-35-year-old blood donors as the group with the highest rate of CMV seroconversion per year (1.33% vs. 0.46%; P < 0.0001).

CONCLUSIONS

We conclude that the risk of primary CMV infection is a continuous lifelong event and correlates with age and female gender.

Local inhibition of chlorhexidinum on Lewis pulmonary carcinoma in mice

C57 inbred mice (n = 100) were employed to develop animal models of Lewis pulmonary carcinoma. The study on the tumor inhibition was performed by infiltrative injection of 3.5% Cy or chlorhexidinum of two different concentrations around the tumor respectively. The survival, survival rate, tumor growth rate, and pulmonary metastasis node number were compared. The results showed that the inhibitory effects of 0.1% and 0.5% chlorhexidinum were the same as that of 3.5% Cy, but the toxic and side effects were obviously reduced as compared with 3.5% Cy. The optimal concentration of chlorhexidinum was 0.5%. This provides a new approach for infiltrative injection of the tumor for clinical use.

[Effects of simulated acid rain on chloroplast activity in Dimorcarpus longana Lour. cv. wulongling leaves]

A decreased content of chlorophyll (Chl) and carotenoid (Car) was found in the Dimorcarpus longana Lour. cv. wulongling leaves when treated with < pH 3.5 acid rain. The decline of Chl content was caused by the reduction of Chla, while Chlb was less sensitive to the acid rain, which resulted in a decrease of Chla/Chlb ratio. The content of Car and the ratio of Chla to Chlb reduced with the duration of stress time. The injury of acid rain to photosynthetic pigments was intensified by illumination. The activities of photoreduction, photophosphorylation and H(+)-ATPase activity decreased with the reduction of pH value under the simulated acid rain. Therefore, the injury of electron transport chain and the uncoupling of photophosphorylation might lead to the ineffective absorption, transportation and transformation of light energy. In our study, the process of photophosphorylation was more sensitive to acid rain than that of photoreduction.

Dynamics of single and multiple bubbles and associated heat transfer in nucleate boiling under low gravity conditions

Experimental studies and numerical simulation of growth and lift-off processes of single bubbles formed on designed nucleation sites have been conducted under low-gravity conditions. Merging of multiple bubbles and lift-off processes during boiling of water in the parabola flights of KC-135 aircraft were also experimentally studied. The heating area of the flat heater surface was discretized and equipped with a number of small heating elements that were separately powered in the temperature-control mode. As such, the wall superheat remained nearly constant during the growth and departure of the bubbles, whereas the local heat flux varied during the boiling process. From numerical calculation it is found that peak of heat flux occurs locally at the contact line of bubble and heater surface. Dry conditions exist inside the bubble base area, which is characterized through a zero heat flux region in the numerical calculation and a lower heat flux period in the experimental results. During the merger of multiple bubbles, dry-out continues. In both the numerical calculations and experimental results, the bubble lift-off is associated with an apparent increase in heat flux. Wall heat flux variation with time and spatial distribution during the growth of a single bubble from numerical simulations are compared with experimental data.

Estimating the distribution of worm burden and egg excretion of Schistosoma japonicum by risk group in Sichuan Province, China

During autumn 2000 an extensive cross-sectional survey of the prevalence of Schistosomiasis japonicum was conducted among about 4000 villagers within 20 villages in the Anning River Valley located in the southwestern Sichuan Province. Two procedures were used to assess infection status, the Kato-Katz thick smear procedure and a miracidia hatch test. Whereas the Kato-Katz procedure provides information on both prevalence and intensity, the hatch test provides only prevalence data, albeit on a much larger volume of stool. In addition, we performed Kato-Katz smears for 15 consecutive samples on a subset of 15 individuals. The proportion of both hatch-test and Kato-Katz positive individuals in the larger cross-sectional survey was 25%. The goal of the study was to estimate both the egg and worm distributions among risk groups using both the hatch and Kato-Katz tests from the cross-sectional data and the repeated Kato-Katz smears from the longitudinal data sets. As a prelude to parameter estimation, individuals were classified into risk groups by natural village and occupation; the proportion of Kato-Katz positive subjects among the risk groups varied from 10% to 60%. We used the statistical model of de Vlas et al. (1992) and Bayesian techniques to derive both estimates of and inference about the worm and egg distribution parameters. The parameter estimates imply (1) similar eggs per gram stool (e.p.g.) per worm pair compared with earlier estimates, (2) a range of worm burdens among the risk groups and (3) estimates of risk heterogeneity within groups is sensitive to prior information on the within-person variability in egg excretion.

[Regulation function of calcium on photosynthesis of Dimocarpus longana Lour. cv. wulongling under simulated acid rain stress]

Studies on the regulation function of calcium on photosynthesis of Dimocarpus longana under simulated acid rain stress showed that the photoreduction activity of chloroplasts was activated when the concentration of calcium ion in reaction medium ranged from 0 to 5 mmol.L-1, and peaked at the 3.5 mmol.L-1, which was 41.90% higher than that of control. Conversely, the activity of chloroplasts reduced 26.06% in the reaction medium with a concentration of 2 mmol.L-1 EGTA, as compared with the control. Both Mn2+ and Mg2+ could inhibit photoreduction activity. The photophosphorylation activity increased when the concentration of calcium ion in reaction medium ranged from 0 to 6 mmol.L-1, and peaked at the 4.5 mmol.L-1, while superoxidase dismutase (SOD) activity rose from 0 to 6 mmol.L-1 and peaked at 6 mmol.L-1. Calcium ion with the concentration of both 10 mmol.L-1 and 15 mmol.L-1 could increase the content of chlorophyll(Chl), stabilize the membrane structure of leaf discs, and reduce the membrane permeability under simulated acid rain with pH value of 3.0. The effect in 15 mmol.L-1 were better than in 10 mmol.L-1. However, the injury of acid rain to leaves was strengthened when the concentration of calcium was higher than 20 mmol.L-1. Net photosynthesis rate (Pn) rose when leaves sprayed with 15 mmol.L-1 Ca(NO3)2 before treatment of acid rain stress of pH 2.5. All of the results represented the excellent protection function of calcium on D. longana leaves under simulated acid rain.

Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum

The genome sequence of the solvent-producing bacterium Clostridium acetobutylicum ATCC 824 has been determined by the shotgun approach. The genome consists of a 3.94-Mb chromosome and a 192-kb megaplasmid that contains the majority of genes responsible for solvent production. Comparison of C. acetobutylicum to Bacillus subtilis reveals significant local conservation of gene order, which has not been seen in comparisons of other genomes with similar, or, in some cases closer, phylogenetic proximity. This conservation allows the prediction of many previously undetected operons in both bacteria. However, the C. acetobutylicum genome also contains a significant number of predicted operons that are shared with distantly related bacteria and archaea but not with B. subtilis. Phylogenetic analysis is compatible with the dissemination of such operons by horizontal transfer. The enzymes of the solventogenesis pathway and of the cellulosome of C. acetobutylicum comprise a new set of metabolic capacities not previously represented in the collection of complete genomes. These enzymes show a complex pattern of evolutionary affinities, emphasizing the role of lateral gene exchange in the evolution of the unique metabolic profile of the bacterium. Many of the sporulation genes identified in B. subtilis are missing in C. acetobutylicum, which suggests major differences in the sporulation process. Thus, comparative analysis reveals both significant conservation of the genome organization and pronounced differences in many systems that reflect unique adaptive strategies of the two gram-positive bacteria.

[Expression of neural cell adhesion molecule in murine livers with experimental autoimmune hepatitis]

OBJECTIVE

To investigate the expression of neural cell adhesion molecule (NCAM) in murine livers with experimental autoimmune hepatitis (EAH) and its relationship with histological grades.

METHODS

To induce the EAH model, the syngeneic S-100 antigen emulsified in complete Freud's adjuvant was injected intraperitoneally to C57Bl/6 at day 1 and day 7. The mice were sacrificed at day 7, 14, and 21 after the first immunization. The expression of NCAM was observed using histoimmunochemistry and RT-PCR.

RESULTS

The expression of NCAM increased gradually with aggravation of lymphocyte infiltration and hepatocyte injury. The administration of prednisolone decreased the histological grade, and inhibited the expression of NCAM. There was a correlation between the expression of NCAM and histological grade (r=0.71, P<0.01).

CONCLUSIONS

NCAM provides a traffic signal for infiltration of lymphocytes in the liver, hence induces the injury of hepatocytes.

[Polycystic ovaraian syndrome and hyperinsulinemia]

OBJECTIVE

To identify the relationship between polycystic ovarian syndrome and hyperinsulinemia.

METHODS

Age, body height, body weight, serum estradiol, progesterone, testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), triiodothyronine (T3), tetraiodothyronine (T4), insulin, oral glucose tolerance test (OGTT), and cortisol were measured in 28 patients with polycystic ovarian syndrome (PCOS).

RESULTS

Sxiteen patients (57.1% of total) had hyperinsulinemia. Among them one patient was found diabetic. No difference was noted in age, height, body weight, body mass index, serum estradiol, progesterone, testosterone, FSH, LH, PRL, T3, T4, cortisol, and glucose of OGTT between hyperinsulinemia and non-hyperinsulinemia patients. However the LH/FSH ratio (2.4 +/- 1.5) in hyperinsulinemia patients was significantly higher than 1.2 +/- 0.6 in non-hyperinsulinemia patients (P = 0.0125). In addition, the results showed that the fasting serum insulin, insulin after OGTT, the insulin/glucose ratio at 30, 120 minutes, 180 minutes, the area under curve of and the insulin, insulin resistant index (IRI) were higher in hyperinsulinemia pateints than in non-hyperinsulinemia patients respectively. Furthermore, the fasting insulin level, insulin/glucose ratio were found to be negatively related to insulin sensitivity index and positively related with beta-cell functioning index.

CONCLUSION

Hyperinsulinemia and insulin resistance accompany with some of the PCOS patients in China. Further investigations will be necessary to clarify the relevant mechanisms.

Comparison of different methods of total RNA extraction for viral detection in sputum

Examination of sputum specimens can be used for monitoring airway inflammation by means of immunological and molecular techniques. RNA extraction is essential for measurement of cytokine gene expression and for detection of many viral pathogens in sputum. In this study, three RNA extraction methods used commonly (acid guanidinium thiocyanate-phenol-chloroform extraction, Trizol and RNeasy Mini kit) were compared on the sputum of 14 patients who had chronic obstructive pulmonary disease. The effect of dithiothreitol pre-treatment on sputum RNA extraction was also investigated. The yield and purity of total RNA were determined by spectrophotometry. Reverse transcription-polymerase chain reaction (RT-PCR) results of the house keeping gene (glyceraldehyde-3-phosphate dehydrogenase) and RNA sequences specific to common respiratory viruses were compared. The results showed that (1) total RNA extracted with Trizol had highest yield and purity among the three RNA extraction methods; (2) there was no significant difference among the three RNA extraction methods on the house keeping gene and viral detection by RT-PCR; (3) dithiothreitol pre-treatment did not improve either the purity of total RNA, or RT-PCR signal. Moreover, dithiothreitol treatment reduced significantly the yield of total RNA. The results of the study indicate that the Trizol method appears to be superior for total RNA extraction from sputum, and dithiothreitol pre-treatment does not increase the efficiency of RNA extraction and RNA detection in sputum specimens.

[Time for extubation and sequential noninvasive mechanical ventilation in COPD patients with exacerbated respiratory failure who received invasive ventilation]

OBJECTIVE

To discuss the optimal time for extubation and sequential non-invasive mechanical ventilation in COPD patients with exacerbated respiratory failure who received invasive ventilation.

METHODS

24 patients received invasive ventilation for 3 days were randomly assigned to receive noninvasive ventilation (study group) or to continue the weaning process with invasive ventilation (control group). The incidence of ventilator-associated pneumonia (VAP), the incidence of death, the duration of ventilation, the hospitalization were analyzed in two groups.

RESULTS

Between study group and control group, the incidence of VAP was 0/12 vs 7/12, P = 0.027; the incidence of death was 0/12 vs 3/12, P = 0.217; the continued duration of ventilation after invasive ventilation for 3 days was (7 +/- 5) days vs (15 +/- 12) days, P < 0.05; the hospitalization was (16 +/- 6) days vs (25 +/- 12) days, P < 0.05, respectively.

CONCLUSIONS

In COPD patients with exacerbated respiratory failure who received invasive ventilation, invasive ventilation for 3 days followed by noninvasive ventilation may decrease the incidence of VAP, shorten the duration of ventilation and hospitalization.

A protocol for geographically randomized snail surveys in schistosomiasis fieldwork using the global positioning system

A protocol was created for performing geographically randomized snail surveys for schistosomiasis research using the global positioning system (GPS). This protocol differs from traditional surveys in its ability to accurately map and measure the spatial distribution of snail habitat. The protocol was used to map irrigation ditches, the primary habitat for Oncomelania hupensis, in two residence areas in Sichuan Province, China. From the 7,450 meters of mapped ditches, snail surveys were performed at 203 random sites along the ditch network. Of these, 116 (57.1%) sites had snails. The total number of living snails captured was 2,014, resulting in an average snail density of 0.27 snails per linear meter of potential habitat.