Study of inhibitory effects and action mechanism of the novel fungicide pyrimorph against Phytophthora capsici

The antifungal activity of the novel fungicide pyrimorph, (E)-3-[(2-chloropyridine-4-y1)-3-(4-tert-butylpheny1)acryloyl]morpholin, against Phytophthora capsici was investigated in vitro. Pyrimorph inhibited different stages in the life cycle of P. capsici including mycelial growth, sporangium production, zoospore release, and cystospore germination with EC(50) values of 1.84, 0.17, 4.92, and 0.09 microg mL(-1), respectively. The effect of pyrimorph on mycelial growth was reduced by the addition of different concentrations of ATP, which suggested that the action mechanism of pyrimorph was connected with impairment of the energy generation system. Meanwhile, pyrimorph exhibited certain inhibition on metabolic approaches of Embden-Meyerhof-Parnas (EMP), tricarboxylic acid cycle (TCA), and hexosemonophosphate (HMP) by measuring the oxygen consumption of pyrimorph combining with three representative inhibitors to the metabolic approaches. The results indicated that pyrimorph could inhibit the approach of HMP significantly. Morphological and ultrastructural studies showed that pyrimorph caused excessive septation and swelling of hyphae, distortion and disruption of most vacuoles, thickening and development a multilayer cell wall, and accumulation of dense bodies. These results suggested pyrimorph exhibited multiple modes of action including impairment of the energy generation system and effect on cell wall biosynthesis directly or indirectly.

Primary study on mode of action for macrocyclic fungicide candidates (7B3, D1) against Rhizoctonia solani Kuhn

A novel macrolactam fungicide candidate (7B3) and a novel aza-macrolactone fungicide candidate (D1) were designed and synthesized, and the bioassay showed that both displayed excellent fungicidal activity against Rhizoctonia solani Kuhn. To elucidate the biochemical mode of action of the two compounds against R. solani and illustrate the similarities and differences of action mechanism resulting from subtle differences in structure of the two compounds, the effects of the two compounds on the ultrastructure of hyphae, electrolyte leakage, and respiration of mycelia cell suspension caused by 7B3 or D1 were studied. The results showed that the two compounds had very similar modes of action. Both induced irregular swelling of hyphae, vacuolation of cytoplasm, and thickening of cell wall. The conductivity of mycelia cell suspension increased in the presence of 7B3 or D1, which indicated that the two compounds had a similar effect on cell membrane permeability. In addition, both 7B3 and D1 were insufficient in inhibiting the respiration of mycelia.

Recent progress of highly efficient in vivo biological screening for novel agrochemicals in China

This paper describes the recent progress of in vivo biological screening for pesticides in China. According to the criteria, including the severity of damage caused by pests and the economic value of the crops, the investigated insects, pathogens, herbs and other species in the agricultural field were selected as the main screening targets for pesticides. Corresponding in vivo microscreening methods have been established and applied in the pesticide screening procedure, which has higher reproducibility, a shorter time and greater efficiency that offset the drawbacks of conventional methods for pesticide screening.

Pharmacokinetics and anti-inflammatory pharmacodynamics of prednisolone in cynomolgus monkey

The purpose was to investigate whether the pharmacokinetics and pharmacodynamics of prednisolone in the non-human primate was an appropriate surrogate for man. After single intravenous doses of 0.03, 0.3, and 3 mg kg(-1), prednisolone demonstrated a dose-dependent clearance and volume of distribution. When corrected for concentration-dependent protein binding, the free clearance was linear at the tested dose levels. The protein binding-corrected volume of distribution was similar across doses. The serum half-life was estimated as being between 2 and 4 h. Prednisolone exhibits near complete inhibition of the cytokines TNF-alpha, IL-1beta, IL-6 and IL-8 with very similar IC50 estimates from 0.09 to 0.16 microg ml(-1) (from 0.24 to 0.44 microM). The monkey demonstrated a similar pharmacokinetics-pharmacodynamics profile of prednisolone when compared with man (from the literature).

Clinical Significance of Telomerase Activity in Gastric Carcinoma and Peritoneal Dissemination

Telomerase activity is responsible for telomere maintenance and is believed to be crucial in most cancer cells, but its significance in gastric cancer remains unknown. This observational study investigated whether there is a relationship between telomerase activity and the development of gastric cancer, and between telomerase activity and peritoneal dissemination. Telomerase activity was measured in primary gastric cancers and in peritoneal washings from the same patients, and findings were compared with those of conventional cytology and an immunoassay for cancer antigen 125 (CA125). Positive cytological examination and telomerase activity in peritoneal washings both correlated with the histological grade, depth of tumour invasion, area of serosal invasion and peritoneal metastasis. The detection of free cancer cells in peritoneal washings by the telomeric repeat amplification protocol/enzyme-linked immunosorbent assay (TRAP–ELISA) was significantly more sensitive than cytology or the CA125 immunoassay, suggesting that this could be used to diagnose early peritoneal dissemination.

Effects of Polymorphism of the β1 Adrenoreceptor and CYP2D6 on the Therapeutic Effects of Metoprolol

Metoprolol is a lipophilic β1 selective adrenergic receptor antagonist used in antihypertensive therapy. It is metabolized by the protein product of the cytochrome P450 2D6 ( CYP2D6) gene. Few studies have been performed on the association between the β1 adrenoreceptor, CYP2D6 polymorphism and blood pressure. The one reported here is a prospective, observational, clinical study in Chinese Han hypertensive patients on the combined influences of CYP2D6 and β1 adrenoreceptor polymorphisms on the therapeutic effects of metoprolol in 300 out-patients with essential hypertension. The same dose of metoprolol achieved different therapeutic effects in patients with different CYP2D6 and β1 adrenoreceptor polymorphisms. Additionally, different doses of metoprolol could achieve the same therapeutic effects in patients with different CYP2D6 and β1 adrenoreceptor polymorphisms. Knowledge of the combination of CYP2D6 and β1 adrenoreceptor polymorphisms may be used to guide antihypertensive therapy using β1 adrenoreceptor antagonists.

Audiological and genetic features of the mtDNA mutations

CONCLUSIONS

Significant difference in the incidence of mitochondrial DNA (mtDNA) mutations was found between the Chinese and USA populations. The identification of the mtDNA A1555G mutation in a large proportion of Chinese probands with nonsyndromic sensorineural hearing loss (NSHL) provides a molecular explanation for the high prevalence of aminoglycoside-induced deafness in China.

OBJECTIVE

The aim was to characterize the audiological and genetic features of NSHL due to mutations in mtDNA.

SUBJECTS AND METHODS

The mtDNA and audiogram analyses were performed in 498 NSHL patients (290 from China and 208 from the USA) with and without history of aminoglycoside exposure. A PCR and restriction enzyme digestion protocol was used for mutational screening and the European Workshop on Genetic Hearing Loss criteria were applied for audiological classification.

RESULTS

All Chinese probands (15.5%) with mtDNA mutation were found to carry the homoplasmic mtDNA A1555G mutation, whereas four probands (1.9%) from the USA were found to carry the mtDNA A1555G and two (1%) had mtDNA G7444A. Approximately 63% of the probands with mtDNA mutations had post-lingual hearing loss and 56.8% of them had a medical history of exposure to aminoglycosides. Hearing losses are bilateral, sensorineural, and symmetric. The main audiogram shapes found were sloping.

Prevalence of irritable bowel syndrome among undergraduates in Southeast China

BACKGROUND

There is a wide range in reported prevalence of irritable bowel syndrome worldwide. From the data appeared recently in medical literatures in China, it seems that the incidence of irritable bowel syndrome in young adults is not dissimilar to the one in the Western countries.

AIMS

To explore the prevalence and epidemiological variations of irritable bowel syndrome in an undergraduate student population in Southeast China on the basis of the Rome II and Rome III criteria.

METHODS

All the undergraduate student participants were administered self-report diagnostic measures for irritable bowel syndrome.

RESULTS

The sex-adjusted prevalence rate of irritable bowel syndrome was 4.7% (Rome II) and 10.4% (Rome III), respectively. When we combined irritable bowel syndrome mixed and irritable bowel syndrome unsubtyped in the Rome III subgroups into one group considering the counterpart in the Rome II subgroups was alternative irritable bowel syndrome, the agreement between the two ways to subdivide these 54 patients who were identified with irritable bowel syndrome by both the two criteria was 81%, with a kappa value of 0.67. By the Rome III criteria, we found a female predominance which was especially attributed to the subtypes of irritable bowel syndrome with constipation and unsubtyped.

CONCLUSIONS

Our study suggests that, in young adults in Southeast China, changing diagnostic criteria for irritable bowel syndrome from Rome II to Rome III may affect women more than men on not only the overall prevalence rate but also the sex-difference present or not, especially in irritable bowel syndrome with constipation and irritable bowel syndrome unsubtyped subgroups.

A high resolution EEG study of dynamic brain activity during video game play

A high resolution EEG study was conducted on healthy human subjects during video game play. Throughout the game playing experiment short time segments of spontaneous activity were recorded. Spectral analysis was performed on these segments for the theta-wave (4-8 Hz) and alpha-wave (8-13 Hz) bands to investigate the modulatory effects of long-lasting game play and the dynamic changes of spectral contribution in range of alpha-and theta-wave. The present results revealed that a) the frontal midline theta-wave activity increased over time relative to the eye open resting condition and b) the parietal alpha-wave activity initially decreased relative to the resting condition, then followed by a slow increase. These experimental results indicate the high resolution EEG provides a useful quantitative analysis tool for studying dynamic brain activity.

A distinct spectrum of SLC26A4 mutations in patients with enlarged vestibular aqueduct in China

There is a worldwide interest in studying SLC26A4 mutations that are responsible for enlarged vestibular aqueduct (EVA) in different ethnic background and populations. The spectrum of SLC26A4 mutations in Chinese population is yet to be fully characterized. In this study, all the 21 exons of SLC26A4 were screened in 107 Chinese patients with hearing loss associated with EVA or both EVA and Mondini dysplasia (MD), taken from six multiplex and 95 simplex families. The two types of control populations consisted of 84 normal-hearing subjects and 46 sensorineural hearing loss subjects without inner ear malformations. Biallelic mutations were found in 12 patients from multiplex families and 84 patients (88.4%) from the simplex families. In addition, monoallelic variant was detected in nine patients in the remaining 11 simplex families. Overall, up to 97.9% patients were found having at least one possible pathogenic variant in SLC26A4, with most having biallelic variants consistent with recessive inheritance of this disorder. A total of 40 mutations including 25 novel mutations were identified in the Chinese patients but were not detected in all the controls except for one normal subject. For the Chinese mutation spectrum of SLC26A4 gene, IVS 7-2A>G mutation was the most common form accounting for 57.63% (102/177) of all the mutant alleles.

Towards the development of a fossil bone geochemical standard: An inter-laboratory study

Ten international laboratories participated in an inter-laboratory comparison of a fossil bone composite with the objective of producing a matrix and structure-matched reference material for studies of the bio-mineralization of ancient fossil bone. We report the major and trace element compositions of the fossil bone composite, using in-situ method as well as various wet chemical digestion techniques. For major element concentrations, the intra-laboratory analytical precision (%RSD(r)) ranges from 7 to 18%, with higher percentages for Ti and K. The %RSD(r) are smaller than the inter-laboratory analytical precision (%RSD(R); <15-30%). Trace element concentrations vary by approximately 5 orders of magnitude (0.1 mg kg(-1) for Th to 10,000 mg kg(-1) for Ba). The intra-laboratory analytical precision %RSD(r) varies between 8 and 45%. The reproducibility values (%RSD(R)) range from 13 to <50%, although extreme value >100% was found for the high field strength elements (Hf, Th, Zr, Nb). The rare earth element (REE) concentrations, which vary over 3 orders of magnitude, have %RSD(r) and %RSD(R) values at 8-15% and 20-32%, respectively. However, the REE patterns (which are very important for paleo-environmental, taphonomic and paleo-oceanographic analyses) are much more consistent. These data suggest that the complex and unpredictable nature of the mineralogical and chemical composition of fossil bone makes it difficult to set-up and calibrate analytical instruments using conventional standards, and may result in non-spectral matrix effects. We propose an analytical protocol that can be employed in future inter-laboratory studies to produce a certified fossil bone geochemical standard.

Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded) allograft

Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as controls and the experimental groups comprised autologous bone marrow derived stem cell seeded allograft, biphasic calcium phosphate (BCP) and tricalcium phosphate (TCP), respectively. All implants were implanted in the back muscle of adult Dutch milk goats for 12 weeks. Micro-computed tomography (microCT) analysis and histomorphometry was performed to evaluate and quantify ectopic bone formation. In good agreement, both microCT and histomorphometric analysis demonstrated a significant increase in bone formation by cell-seeded calcium phosphate scaffolds as compared to the autograft, allograft and cell-seeded allograft implants. An extensive resorption of the autograft, allograft and cell-seeded allograft implants was observed by histology and confirmed by histomorphometry. Cell-seeded TCP implants also showed distinct signs of degradation with histomorphometry and microCT , while the degradation of the cell-seeded BCP implants was negligible. These results indicate that cell-seeded calcium phosphate scaffolds are superior to autograft, allograft or cell-seeded allograft in terms of bone formation at ectopic implantation sites. In addition, the usefulness of microCT for the efficient and non-destructive analysis of mineralised bone and calcium phosphate scaffold was demonstrated.

RP-HPLC analysis of flucloxacillin in human plasma: validation and application to a bioequivalence study

A RP-HPLC method with rapid sample processing was developed for quantitation of flucloxacillin in human plasma using dicloxacillin as the internal standard. The plasma sample (100 microL) was acidified with glacial acetic acid, and deproteinized by precipitation with acetonitrile. The supernatant was directly injected into the HPLC system. Separation was achieved on an Alltima C18 column (250 mmx4.6 mm I.D., 5 microm), with a mixture of 10 mmol x L(-1) KH2PO4-acetonitrile (64.5:35.5, v/v) as mobile phase. The assay was successfully applied to a randomized, two-period cross-over bioequivalence study in 20 healthy Chinese volunteers following a single oral dose of 250 mg flucloxacillin capsules. A non-compartmental method was used for pharmacokinetic analysis. Compared with data in the literature, flucloxacillin was eliminated more slowly in Chinese than in Caucasians. Cmax, AUC(0-t) and AUC(0-infinity) were tested for bioequivalence after log-transformation of data. No significant difference was found. Tmax was analyzed by Wilcoxon's test and no significant difference was obtained (P > 0.05). Based on these statistical inferences, the two formulations were judged to be bioequivalent and, thus, can be prescribed interchangeably.