Inhibition of Aspergillus flavus growth and aflatoxin B1 production by natamycin

Aspergillus flavus causes huge crop losses, reduces crop quality and has adverse effects on human and animal health. A large amount of food contaminated with aflatoxin can greatly increase the risk of liver cancer. Therefore, prevention and control of aflatoxin production have aroused attention of research in various countries. Natamycin extracted from Streptomyces spp. has been widely used in production practice due to its good specificity and safety. Here, we found that natamycin could significantly inhibit fungal growth, conidia germination, ergosterol and AFB1 production by A. flavus in a dose-dependent manner. Scanning electron microscope analysis indicated that the number of conidia was decreased, the outer wall of conidia was destroyed, and the mycelia were shrivelled and tangled by natamycin. RNA-Seq data indicated that natamycin inhibited fungal growth and conidia development of A. flavus by significantly down-regulating some genes involved in ergosterol biosynthesis, such as Erg13, HMG1 and HMG2. It inhibited conidia germination by significantly down-regulating some genes related to conidia development, such as FluG and VosA. After natamycin exposure, the decreased ratio of aflS/aflR caused by the down-regulation of all the structural genes, which subsequently resulted in the suppression of AFB1 production. In conclusion, this study served to reveal the inhibitory mechanisms of natamycin on fungal growth and AFB1 biosynthesis in A. flavus and to provide solid evidence for its application in controlling AFB1 contamination.

Fate of a Soliton in a High Order Spatial Mode of a Multimode Fiber

We show numerically that under certain conditions noise-induced soliton self-mode conversion dominates over soliton self-frequency shift for a soliton in a high order spatial mode of a multimode optical fiber. The input soliton has to be group index matched to a lower order mode for a frequency separation for which the Raman gain is non-negligible, and this condition determines the wavelength of the pulse growing from noise. The phenomenon has no known analogs in single-mode or graded-index fibers. The results demonstrate that it is possible for a noise-induced physical process to dominate over a seeded one even for noise levels at the fundamental limit.

New oral anticoagulants: appropriateness of prescribing in real-world setting

BACKGROUND

The new oral anticoagulants (NOAC) have been extensively studied in the clinical trial setting; however, concerns remain about the safety of prescribing in the elderly and patients with renal impairment.

AIM

The aim of this study was to assess the appropriateness of NOAC prescribing in a real-world setting in terms of patient selection and to compare patient demographics to those included in pivotal clinical trials.

METHODS

One hundred and seventy-six patients from three tertiary university teaching hospitals were identified over 3 months in 2014.

RESULTS

Median age of the cohort was 74 years (interquartile range: 61-81 years), with a range of 23-96 years. Overall, 34% of the study population were prescribed a NOAC inappropriately. Of these, treatment was contraindicated in 40%, predominantly due to severe renal impairment, 22% were prescribed an excessively high dose, while 38% were under dosed. Although community-initiated patients had poorer renal function (glomerular filtration rate 91.7 ± 55.7 vs 69.3 ± 38.9, P = 0.024), appropriateness of prescription was no different compared to hospital-initiated patients (78% during admission cf. 61% prior, P = 0.061). Appropriate prescribing was better in patients with venous thromboembolism compared to AF (85% appropriate cf. 60%, P = 0.021).

CONCLUSION

Our findings imply that there remains considerable uncertainty about appropriate prescribing and dosing of NOAC, particularly in patients with impaired renal function. We recommend judicious prescribing and regular monitoring of renal function in patients at high risk of complications from NOAC therapy.

Socioeconomic inequalities in dental caries among 5-year-olds in four Chinese provinces

OBJECTIVE

To explore socioeconomic inequalities in dental caries among 5-year-olds in four Chinese provinces.

METHODS

This study used data from 1,732 children living in Guangxi, Hubei, Jilin and Shanxi who participated in the Third National Oral Health Survey in 2005. Questionnaires were completed by parents to collect information on family socioeconomic position (parental education and household income) and children's dental behaviours (toothbrushing frequency, sugar intake frequency and last dental visit). Children were clinically examined for dental caries, which was reported using the dmft index. Socioeconomic inequalities in children's caries experience were assessed in negative binomial regression models.

RESULTS

There were significant gradients in children's dmft by household income. Children's dmft increased from 2.63 in the highest income group to 4.70 in the lowest income group. However, parental education was not significantly related to childhood dental caries.

CONCLUSION

Clear social gradients in caries experience of deciduous teeth were found by household income but not parental education.

An introduction to clinical practice guideline for Chinese undergraduates in stomatology

The Society of Dental Education, Chinese Stomatological Association has formulated the Standards of Clinical Practice for Chinese Undergraduate Students Majoring in Stomatology, on the basis of extensively soliciting the views of experts in various fields. The aim of this standard is to guide clinical teaching and improve teaching quality in schools of stomatology in China. The standards include eight parts: the standard of clinical practice for oral and maxillofacial surgery, for cariology and endodontics, for periodontics, for the oral mucosa diseases, for preventive dentistry, for pedodontology, for prosthodontics and for oral imageology. Each part includes introduction to subjects, the clinical practice time period, the purpose and requirements of practice, the disease types of practice and items of clinical operation, the index of the lowest workload of practice and the major methods of assessment. These standards are not only the basic requirements and guiding principles for clinical teaching, but also the major criteria for assessing the clinical teaching quality of stomatological colleges/schools of China.

Broadband parametric wavelength conversion at 1 μm with large mode area fibers

Fiber-optic parametric wavelength conversion (PWC) below the zero-dispersion wavelength of silica is typically constrained by the requirement of a small, tightly confined mode with anomalous dispersion to achieve phase matching. This limits the ability to power scale PWC at arbitrary wavelengths. However, the constraint is lifted for higher-order modes. We demonstrate PWC in the 1 μm band via degenerate four-wave mixing pumped in a large effective area (>600  μm²) LP(0,7) mode of a double-clad fiber. We obtain up to 25% conversion in to the Stokes line with 0.5 ns pump pulses, corresponding to ~20  kW peak power at the converted wavelength.

Wearable medical devices for tele-home healthcare

The world's ageing population and prevalence of chronic diseases have lead to high demand for tele-home healthcare, in which vital-signs monitoring is essential. An overview of state-of-art wearable technologies for remote patient-monitoring is presented, followed by case studies on a cuffless blood pressure meter, ring-type heart rate monitor, and Bluetoothtrade mark-based ECG monitor. Aim of our project is to develop a tele-home healthcare system which utilizes wearable devices, wireless communication technologies, and multisensor data fusion methods. As an important part of this system, a cuffless BP meter has been developed and tested on 30 subjects in a total of 71 trials over a period of five months. Preliminary results show a mean error (ME) of 1.82 mmHg and standard deviation of error (SDE) of 7.62 mmHg in systolic pressure; while ME and SDE in diastolic pressure are 0.45 mmHg and 5.27 mmHg, respectively.

Glycopeptide prescribing in an Australian tertiary paediatric hospital

OBJECTIVE

To assess the extent and appropriateness of glycopeptide use in a tertiary Australian Paediatric hospital.

METHODOLOGY

A retrospective analysis of prescriptions during a six-month period between July 1999 and January 2000. Medical records were examined and prescribing practices compared with the recommendations of the Hospital Infectious Control Practices Advisory Committee (HICPAC) and the Infectious Diseases Society of America (IDSA).

RESULTS

Fifty-one patients were identified who received a total of 98 glycopeptide prescriptions. The Haematology/ Oncology unit prescribed 71/98 (72.4%). 68/98 (69.4%) patients received vancomycin, 9/98 (9.2%) received teicoplanin and 21/98 (21.4%) a combination of both. 81/98 (82.7%) had central venous catheters and 69/98 (70.4%) were immunocompromised. 48/98 (49%) prescriptions were for empiric treatment with 38/98 (38.8%) for prophylaxis and 11/98 (12.2%) therapeutic. 19/98 (19.4%) prescriptions were deemed appropriate, 6 (6.1%) by HICPAC criteria, and a further 13 (13.3%) by IDSA or other criteria. Of 19 prescriptions started appropriately, only 7/17 (41.1%) were continued appropriately beyond 48 h. Appropriate cultures were taken before prescription in 93.3% of cases. Dose was appropriate in 91/98 (92.9%) and frequency appropriate in all cases. The cost of inappropriate prescribing was approximately $9500.

DISCUSSION

A high rate of inappropriate glycopeptide prescribing was evident in this paediatric population. Inappropriate prescribing existed across all subspecialties. Use was primarily for empiric therapy and prophylaxis in young children with an oncology diagnosis. A number of situations existed where glycopeptide prescription was felt appropriate despite not being included in HICPAC/IDSA guidelines. Areas with high rates of inappropriate prescribing were identified and will be targeted for education and intervention. Audit of practice continues.

Experiences from a school-based oral health promotion programme in Wuhan City, PR China

OBJECTIVES

To evaluate the effect of a six-year oral health promotion programme for school children of Wuhan City, PR China.

METHODS

The programme group (P-group) comprised 233 children who had just entered grade 1 (1989). The programme provided an oral health promotion programme, and 215 12-year-old children from three schools participated as a control group (C-group). After the 6-year period of the programme (1995), all of the children had a clinical examination according to the criteria of the WHO and responded to a structured questionnaire on dental health behaviour.

RESULTS

The results showed that attitudes to dental care, regular tooth brushing habits, use of fluoridated toothpaste, gingival health and dental visits, frequencies of consuming sugary drinks/foods were improved in the p-group when compared with the C-group.

CONCLUSION

The school-based oral health promotion programme should be expanded.

Oral health services in PR China as evaluated by dentists and patients

OBJECTIVE

To describe the function of oral health services and the delivery of oral health care in PR China.

DESIGN

Cross-sectional surveys. Self-administered questionnaires gathered information on professional practices and attitudes of Chinese dentists. Patients were examined clinically for caries and services rendered. Patients were interviewed about oral health status, reason of dental visits and consumption of services, perceived need for care and self-care practices.

SETTING

Wuhan City of the Hubei Province of China.

SUBJECTS

Random samples of dentists (n = 250) working with child and adult patients in 1998 in Wuhan City. Each dentist had a representative sample of 20 patients attending consecutively for care enrolled in the study.

RESULTS

On average, the dentists saw 12 patients per day, with most time devoted to restorative treatment and extraction. The majority of dentists held the opinion that in China little attention is given to preventive care. Forty per cent of the patients were new to the dentists and more than half attended care because of pain or acute symptoms. The reported mean number of decayed, missing, and filled teeth varied from 2.6 for 12-year-old patients to 10.7 for patients aged 65-74. Daily toothbrushing was practised by more than 90% of the patients in all age groups, however, the tradition of regular dental visits was weak. Most patients (51-75 per cent) attended for care due to acute problems or pain.

CONCLUSION

The study indicated the need for reorientation of the Chinese oral health services towards prevention.

Neoadjuvant and adjuvant therapy for operable hepatocellular carcinoma

OBJECTIVES

To determine the efficacy and adverse effects of different neoadjuvant and adjuvant therapies compared to surgery alone or surgery and placebo/supportive therapy when given to improve relapse and survival rates for operable hepatocellular carcinoma.

SEARCH STRATEGY

Electronic databases, conference proceedings, bibliographies of identified publications.

SELECTION CRITERIA

All truly randomised and quasi-randomised clinical trials that compared hepatocellular carcinoma patients who were given and not given neoadjuvant/adjuvant therapy as a supplement to curative liver resection.

DATA COLLECTION AND ANALYSIS

Study data was extracted independently by two reviewers and discrepancies were resolved by consensus. A total of eight randomised controlled clinical trials were identified, totaling 548 randomised patients. Seven of the eight trials reported survival and disease-free survival curves and the results of hypothesis testing (log-rank test). The remaining trial reported only the mean survival times. None reported the hazard ratio and only one did a sample size calculation. The survival and disease-free survival curves were compared using their one, two and three-year survival rates, median survival times and the result of the hypothesis tests.

MAIN RESULTS

The size of the randomised clinical trials ranged from 40 to 115 subjects. Both preoperative (neoadjuvant) and postoperative (adjuvant), systemic and locoregional (+/- embolization), chemo- and immunotherapy interventions were tested. None were comparable in terms of both treatment regimen and participants selected, so no pooling was done. Only one regimen using preoperative transcatheter arterial chemoembolization with doxorubicin was approximately duplicated. Seven of the eight trials reported no survival benefit from adjuvant therapy. Only one trial reported a statistically significant difference for survival and disease-free survival for the treatment arm, but the results of both its arms were very poor when compared to other studies. Two of the trials that did not report any absolute survival advantage reported statistically significant differences in disease-free survival. Five of the eight trials did not perform intention-to-treat analysis. The highest toxicity rate was in a trial using oral 1-hexylcarbamoyl 5-fluorouracil which resulted in 12 out of 38 subjects stopping because of adverse events.

REVIEWER'S CONCLUSIONS

There is no evidence for efficacy of any of the adjuvant protocols reviewed. In order to detect a realistic treatment advantage, larger trials will have to be conducted.