A few-shot learning-based eye diseases screening method

OBJECTIVE

This study aims to construct a brand-new ophthalmic disease screening task and establish a practically valuable ophthalmic disease screening model in the case of insufficient data.

MATERIALS AND METHODS

The main methods are as follows: firstly, we mixed data from different sources (these data may come from different cameras, including different fundus diseases) to get a new dataset. Based on this dataset, we conducted subsequent experiments on fundus multi-disease screening. However, in the past public datasets, each dataset often only corresponded to the screening diagnosis of one disease. Secondly, we proposed a method to simulate the characteristics of different fundus cameras by using a method based on style transfer, and to augment the training data, so that the model could learn the features of ophthalmic diseases in a more comprehensive way. Finally, a robust disease screening model based on few-shot learning was constructed on the combined dataset, and compared with benchmark algorithms.

RESULTS

We focused on the study of eye disease screening methods based on the metric-based few-shot learning model, data augmentation methods, and focus on key technologies such as data augmentation based on style transfer. Experiments have shown that our method can significantly improve the generalization ability of the disease screening model.

CONCLUSIONS

By introducing few-shot learning theory and data augmentation based on style transfer into ophthalmic disease screening, the generalization ability of the model is greatly improved, and it has certain practical value.

Blockade of fatty acid signalling inhibits lipopolysaccharide-induced macrophage recruitment and progression of apical periodontitis

AIM

To examine the role of palmitic acid in lipopolysaccharide (LPS)-stimulated chemotaxis of macrophages and the potential contribution of saturated fatty acid in signalling during the pathogenesis of apical periodontitis.

METHODOLOGY

J774, a mouse macrophage cell line, was used in the experiments. After treatment with LPS, proteolytic maturation of sterol regulatory element-binding protein-1c (SREBP-1c) and expression of fatty acid synthase (FASN) were examined by Western analysis. Levels of palmitic acid were measured by reverse phase-high performance liquid chromatography-mass spectrometry. Knockdown of SREBP-1c and FASN was accomplished by small interfering RNA technology. Secretion of CC-chemokine ligand 2 (CCL2) and cellular chemotaxis were assessed by enzyme-linked immunosorbent assay and transwell migration assay, respectively. Sulfo-N-succinimidyl oleate (SSO) treatment was used to inhibit fatty acid signalling in vitro and also in a rat model of apical periodontitis. All data were first subjected to Levene's test. In vitro data were then analysed using ANOVA followed by Tukey's multiple comparison test. Data from animal experiments were analysed by independent t-tests. The significant level was set at 0.05.

RESULTS

LPS stimulated proteolytic maturation of SREBP-1c and FASN expression in macrophages and significantly enhanced palmitic acid synthesis (P < 0.05). Knockdown of SREBP-1c attenuated LPS-enhanced FASN expression. Knockdown of FASN significantly suppressed LPS-enhanced palmitic acid synthesis (P < 0.05). LPS and exogenous palmitic acid significantly enhanced CCL2 secretion and macrophage chemotaxis (all P < 0.05). Inhibition of FASN expression significantly alleviated LPS-augmented CCL2 secretion (P < 0.05). SSO significantly suppressed CCL2 secretion and macrophage chemotaxis augmented by LPS and palmitic acid (all P < 0.05). In a rat model of induced apical periodontitis, SSO treatment significantly attenuated progression of apical periodontitis and macrophage recruitment (all P < 0.05).

CONCLUSIONS

LPS/SREBP-1c/FASN/palmitic acid signalling contributed to tissue destruction caused by bacterial infection. Modulation of lipid metabolism and signalling may be helpful for the management of apical periodontitis.

Awareness of Colorectal Cancer among the Urban Population in the Klang Valley

BACKGROUND

Colorectal cancer (CRC) is the second most common cancer in Malaysia. Awareness of risk factors, symptoms and warning signs of CRC will help in early detection. This paper presents the level of CRC awareness among the urban population in Malaysia.

METHOD

A cross-sectional study was conducted from November 2015 till December 2016 at three government clinics in the Klang Valley. The validated Bowel Cancer Awareness Measure questionnaire in both English and Malay was used. The mean knowledge scores for the warning signs and risk factors of CRC in different socio-demographic groups were compared using ANOVA in SPSS version 23. Statistical significance was set at p<0.05 and a 95% confidence level.

RESULTS

Of the 426 respondents, 29.1% were unable to recall the warning signs and symptoms of CRC. Average recall was less than two warning signs and symptoms (mean 1.62, SD 1.33). The mean total knowledge score for CRC was 9.91 (SD 4.78), with a mean knowledge scores for warning signs and risk factors at 5.27 (SD 2.74) and 4.64 (SD 2.78), respectively. Respondents with a higher level of education were found to have higher level of knowledge regarding the warning signs of CRC. There was a significant positive association between knowledge score for warning signs and level of confidence in detecting warning signs. Regarding the total knowledge score for CRC, 3.3% of respondents scored zero. For warning signs and risk factors, 8.2% and 8.5% of respondents had zero knowledge scores, respectively.

CONCLUSIONS

Generally, awareness of CRC is poor among the urban population of Klang Valley. Greater education and more confidence in detecting warning signs are significantly associated with better knowledge of warning signs. CRC awareness programs should be increased to improve awareness.

The lymphoid chemokine CCL21 enhances the cytotoxic T lymphocyte-inducing functions of dendritic cells

The potential use of lymphoid chemokines to generate a dendritic cell (DC) cancer vaccine is not yet clear. We investigated the effect of lymphoid chemokines on DC function and on the production of effective cytotoxic T lymphocytes (CTLs) for application of cancer vaccine using monocyte-derived mature DCs (mDCs) prestimulated with lymphoid chemokines. mDCs exposed to a secondary lymphoid organ chemokine (SLC/CCL21) dramatically induced CTL response by increasing cytolytic activity without any significant alterations on expression of cell surface markers (e.g. CD80, CD83, CD86 and CCR7) or on the production of cytokines (e.g. IL-12p70, IL-10 and IL-23). Interestingly, mDCs prestimulated with CCL21 showed higher levels of CXCL10 (IP-10) production, but not the production of CCL22, compared with untreated mDCs. IP-10 treatment during CTL generation with DCs dramatically enhanced tumour-specific CTL response compared with untreated CTLs, and these enhanced CTL-inducing functions of CCL21-treated DCs were inhibited by anti-IP-10 treatment. Taken together, our data suggested an important role of the lymphoid-endothelium-associated chemokine, CCL21, on DCs in the induction of CTL responses.

Whitening and antioxidant activities of bornyl acetate and nezukol fractionated from Cryptomeria japonica essential oil

OBJECTIVES

The aim of this study was to investigate the whitening and antioxidant activities of essential oils from Cryptomeria japonica by determining their tyrosinase inhibition, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activities.

METHODS

Essential oils of C. japonica leaves were extracted with distilled water, and after condensation of volatile constituents, the condensates were extracted with ethyl acetate. Crude essential oils of C. japonica were divided into six fractions by thin layer chromatography and open column chromatography, and their chemical analysis was performed by GC/MS. Major compounds of fractions were composed of kaurene, bornyl acetate, nezukol, (-)-4-terpineol, δ-cadinene, α-terpineol, γ-eudesmol, α-eudesmol and elemol.

RESULTS

For tyrosinase inhibitory activity using two substrates, l-tyrosine and 3,4-dihydroxyphenylalanine (l-DOPA), kaurene, bornyl acetate and nezukol were highly effective. In antioxidant activity, (-)-4-terpinenol and δ-cadinene showed high DPPH radical scavenging activity, and bornyl acetate and nezukol indicated extremely high SOD-like activity.

CONCLUSION

Therefore, bornyl acetate and nezukol fractionated from C. japonica essential oil, which showed highly active whitening and antioxidant activities, have potential applications in cosmeceutical materials.

Experimental study on low-detection limit for immunomagnetic reduction assays by manipulating reagent entities

The low limit of detection (LLD) plays an important role in biomolecular assays, especially for early-stage assays. Biomolecular detections usually involve the use of two main elements: a reagent and an analyzer, which both greatly contribute to the LLD. In this work, the relationships among the LLD and reagent-related factors are investigated. The to-be-detected biomolecule is c-reactive protein (CRP) as an example. The assay method is immunomagnetic reduction (IMR). The components of reagent are Fe(3)O(4) magnetic nanoparticles bio-functionalized with antibodies against CRP, dispersed in pH-7.4 phosphate buffered saline solution. Several key factors of the reagent, such as particle concentration, volume ratio of reagent to sample, and particle size, are manipulated to optimize the LLD of detecting CRP.

Non-invasive and high-sensitivity scanning detection of magnetic nanoparticles in animals using high-Tc scanning superconducting-quantum-interference-device biosusceptometry

Although magnetic nanoparticles (MNPs) have been widely applied to animals in biomedicine, MNPs within animals should be examined in real time, in vivo, and without bio-damaged possibility to evaluate whether the bio-function of MNPs is valid or to further controls the biomedicinal process because of accompanying complex problems such as MNPs distribution and MNPs biodegradation. The non-invasive and high-sensitivity scanning detection of MNPs in animals using ac susceptometry based on a high-T(c) superconducting quantum interference device (SQUID) is presented. The non-invasive results and biopsy results show good agreement, and two gold-standard biomedicine methods, Prussian blue stain and inductively coupled plasma, prove the magnetic results. This confirms that the future clinical diagnosis of bio-functional MNPs could be operated by using scanning SQUID biosusceptometry as conveniently as an ultrasonic probe.

In vivo and real-time measurement of magnetic nanoparticles distribution in animals by scanning SQUID biosusceptometry for biomedicine study

Magnetic nanoparticles have been widely applied to biomagnetism, such as drug deliver, magnetic labeling, and contrast agent for in vivo image, etc. To localize the distribution of these magnetic particles in living organism is the first important issue to confirm the effects of magnetic nanoparticles and also evaluate the possible untoward effects. In this study, a scanning high T(c) rf-SQUID superconducting quantum interference devices (SQUIDs) biosusceptometry, composed of static SQUID unit and scanning coil sets, is developed for biomedicine study with the advantages of easy operation and unshielded environment. The characteristics tests showed that the system had the low noise of 8 pT/Hz at 400 Hz and the high sensitivity with the minimum detectable magnetization around 4.5 × 10(-3) EMU at distance of 13 mm. A magnetic nanoparticle detection test, performed by ex vivo scanning of the magnetic fluids filled capillary under swine skin for simulation of blood vessels in living bodies, confirmed that the system is feasible for dynamic tracking of magnetic nanoparticles. Based on this result, we performed further studies in rats to clarify the dynamic distribution of magnetic nanoparticle in living organism for the pharmacokinetics analysis like drug delivers, and propose the possible physiological metabolism of intravenous magnetic nanoparticles.

Nitric oxide promotes the progression of periapical lesion via inducing macrophage and osteoblast apoptosis

This study aimed to elucidate the modulation by nitric oxide (NO) of the apoptosis of macrophages and osteoblasts, the essential cellular components in the development of periapical lesions. Lipopolysaccharide (LPS) induced prominent nitrite synthesis in J774 mouse macrophage cell lines. Exposure to LPS induced obvious apoptosis in J774 cells, whereas transient transfection with murine inducible nitric oxide synthase (iNOS), small interfering RNA (siRNA) diminished this effect. Tumor necrosis factor-alpha (TNF-alpha) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) (a NO donor) triggered apoptosis in UMR-106 rat osteoblastic cell lines and a synergistic effect was noted when TNF-alpha and SNAP were added to the medium together. Administration of siRNAs for c-Fos and c-Jun: components of activator protein-1 (AP-1) and transforming growth factor-beta1 attenuated the combined effect markedly. Terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) stain in a rat model of induced periapical lesion showed positive apoptotic signals in macrophages and osteoblasts. Administration of N(G)-monomethyl-l-arginine markedly diminished the extent of bone loss and the amounts of apoptotic macrophages and osteoblasts. In conclusion, NO mediates LPS-stimulated apoptosis of macrophages. It also induces osteoblast apoptosis and augments the pro-apoptotic effect of cytokines. Inhibition of NO synthesis in vivo attenuates apoptosis and the size of periapical lesions. Taken together, these results suggest that NO may promote the progression of periapical lesion by inducing the apoptosis of macrophages and osteoblasts.

Knowledge that upper respiratory tract infection resolves on its own is associated with more appropriate health-seeking behaviour and antibiotic cognition

INTRODUCTION

This study aims to study whether knowledge that upper respiratory tract infection (URTI) resolves on its own is associated with more appropriate antibiotic cognition and treatment-seeking behaviour in adult patients seeking consultation for upper respiratory tract symptoms in all nine polyclinics of the National Healthcare Group in Singapore.

METHODS

A prospective study of 595 adult patients who attended for URTI symptoms of less than seven days duration was performed. We collected data using an interviewer-administered structured questionnaire eliciting the participant's personal and demographical data, his knowledge about URTI, past experience with URTI and treatment-seeking behaviour for this current episode of URTI. These variables were then regressed against the variable "URTI resolves on its own", adjusting for "antibiotics relieve URTI faster", "antibiotic used unnecessarily for URTI", "recovery faster with antibiotics" for antibiotic cognition; and "number of days with URTI", "first line of action: self-medicate", "reason for attendance: felt unwell", "reason for attendance: get well faster" and "used prescribed medication before current visit" for health-seeking behaviour.

RESULTS

More than one-third of patients believed that URTI resolved on its own. Subjects who believed that URTI resolved on its own were not significantly different in terms of gender, ethnic group, educational status, age, knowledge of germs as causal, and number of days sick before attendance. However, such patients were 1.68 times (confidence interval [CI] 1.17, 2.41) more likely to agree that, nowadays, antibiotics are used unnecessarily for "flu", and 2.07 times (CI 1.32, 3.24) more likely to self-medicate. They were 0.51 (CI 0.35, 0.76) times more likely to be dependant on prescribed medication.

CONCLUSION

Knowledge that URTI resolves on its own is associated with more appropriate antibiotic cognition and health-seeking behaviour.

Prevalence of Parkinson disease in Singapore: Chinese vs Malays vs Indians

OBJECTIVE

To investigate the prevalence of Parkinson disease (PD) in Singapore and compare the rates between Singaporean Chinese, Malays, and Indians.

METHODS

A three-phase community-based survey among a disproportionate random sample of 15,000 individuals (9,000 Chinese, 3,000 Malays, 3,000 Indians) aged 50 years and above who live in central Singapore was conducted. In phase 1, trained interviewers conducted a door-to-door survey using a validated 10-question questionnaire. In phase 2, medical specialists examined participants who screened positive to any of the questions. Participants suspected to have PD had their diagnosis confirmed in phase 3 by a movement disorders specialist.

RESULTS

The participation rate was 67% among 22,279 eligible individuals. Forty-six participants with PD were identified of which 16 were newly diagnosed cases. The prevalence rate of PD for those aged 50 and above in Singapore was 0.30% (95% CI: 0.22 to 0.41), age-adjusted to US 1970 census. The prevalence rates increased significantly with age. The age-adjusted prevalence rates among Chinese (0.33%, 95% CI: 0.22 to 0.48), Malays (0.29%, 95% CI: 0.13 to 0.67), and Indians (0.28%, 95% CI: 0.12 to 0.67) were the same (p = 1.0).

CONCLUSIONS

The prevalence of PD in Singapore was comparable to that of Western countries. Race-specific rates were also similar to previously reported rates and similar among the three races. Environmental factors may be more important than racially determined genetic factors in the development of PD.

Ethnic differences among Chinese, Malay and Indian patients with type 2 diabetes mellitus in Singapore

INTRODUCTION

Ethnic differences exist in patients with diabetes mellitus. Not much is known about such differences in Asian populations. The aim of the study was to determine ethnic differences among Chinese, Malay and Indian patients with type 2 diabetes mellitus in Singapore.

METHODS

The study design was cross-sectional, involving 967 patients who were attending follow-up care for type 2 diabetes mellitus at a primary care clinic. Data collection was by patient interview, examination, and from case records. Blood and urine samples were collected for analysis of indicators of diabetic control and albuminuria.

RESULTS

Malays had the highest mean body mass index (BMI) after controlling for age, gender, duration of diabetes and exercise status. Adjusted mean BMI for Malays was 27.4kg per square metres, Indians 25.7kg per square metres, Chinese 24.9kg per square metres, with the p value being less than 0.01. HbA1c levels were highest among Indians after controlling for age, duration of diabetes, body mass index and treatment. Adjusted mean HbA1c for Indians was 8.3 percent, Malays 8.0 percent, and Chinese 7.7 percent, with the p value being less than 0.01. Compared with Chinese, Indians were more likely to have a positive family history of diabetes (prevalence rate ratio (PRR) of 1.3, 95 percent confidence interval (CI) of 1.0 to 1.7), but were less likely to have associated hypertension (PRR of 0.7, 95 percent CI of 0.5 to 1.0) and microalbuminuria and macroalbuminuria (PRR of 0.6, 95 percent CI of 0.4 to 1.0).

CONCLUSION

Ethnic differences exist with regard to BMI, diabetic control as reflected by HbA1c levels, family history of diabetes, presence of associated hypertension, and severity of albuminuria. Indians, while having poorer control of diabetes, are less prone to hypertension and renal complications than Chinese.

The use of complementary and alternative medicine by asthma patients

BACKGROUND

Use of complementary and alternative medicines (CAM) by asthmatic patients is increasing. Data on the prevalence of CAM use in asthma are limited, and the motivation for patients to seek CAM therapy is uncertain.

AIM

To determine the prevalence and pattern of use of complementary therapies in adults treated for asthma in primary care in Singapore, and the demographic and clinical factors associated with their use.

DESIGN

Cross-sectional study.

SETTING

Five primary care clinics in Singapore.

METHODS

Adult patients with asthma (n = 802) received a structured questionnaire interview and clinical assessment that included demographic and clinical variables (clinical status, patient's knowledge, self-care and healthcare-seeking behaviour, and spirometric measurements) and detailed information on CAM use in the past one year.

RESULTS

CAM use in the past year was reported by 27.2%, including animal food products (12.3%), herbs (10.3%), herbal-based proprietary medicines (3.2%), and acupuncture or reflexology (1%). The use of CAM was significantly associated with Chinese ethnicity, longer disease duration, moderate and severe persistent asthma, FEV(1)/FVC < 80%, lack of positive response to treatment in the past year, higher patient knowledge score, and multiple sources of care providers.

DISCUSSION

The use of CAM is highly prevalent in Asian patients treated for asthma in primary care, and is associated with cultural and clinical factors reflecting a need to improve care.

Screening for childhood obesity: international vs population-specific definitions. Which is more appropriate?

AIM

The objectives of this study are: (1) to study the relation between body mass index (BMI), percentage-weight-for-height (PWH) and percentage body fat (PBF) in Singaporean Chinese children; (2) to assess the applicability of an international definition of obesity (the International Obesity Task Force (IOTF) BMI) as a screening tool to detect childhood obesity, as compared with the current Singapore population-specific definition using PWH.

METHODS

A total of 623 Chinese children aged 6-11 y (321 males, 302 females) were recruited from a school by proportionate (40%) stratified random sampling. BMI and PWH were calculated from weight and height, while PBF was derived using leg-to-leg bioelectrical impedance analysis. The strength of association among the three indices of obesity was assessed using Spearman's correlation coefficient. Obese children were defined as those above the 95th percentile of PBF in each age-gender-specific group. Sensitivity and specificity of IOTF-BMI cutoff values and PWH cutoff values were compared by testing their ability to correctly identify obese children.

RESULTS

All three indices correlated well with one another (BMI:PWH r=0.83, BMI:PBF r=0.87, PWH:PBF r=0.76). Prevalence of obesity was lower using IOTF-BMI cutoffs (6.9%) than using PWH cutoffs (16.4%). The sensitivity and specificity of IOTF-BMI cutoff values were 75.0 and 96.0%, respectively, with sensitivity differing between boys (83.3%) and girls (66.6%) (P=0.35). In comparison, PWH cutoff values had higher sensitivity (91.6%) but lower specificity (86.6%), with no significant difference between the genders.

CONCLUSION

IOTF-recommended BMI cutoff values had low sensitivity and may underestimate the local prevalence of childhood obesity. For screening purposes, we recommend that population-specific measures rather than international cutoff values be used.

Erectile dysfunction in Singapore: prevalence and its associated factors--a population-based study

PURPOSE

To study the prevalence of erectile dysfunction (ED) in Singapore males aged 30 and above and its association with demographic, medical and other risk factors.

METHODOLOGY

A population based cross sectional study of 729 men aged 30 and above in Singapore was conducted using the abridged, five-item version of the International Index of Erectile Function (IIEF-5). Presence of erectile dysfunction was defined as IIEF-5 score of less than 21. Erectile dysfunction was further categorised into mild (IIEF-5: 16-20), moderate (IIEF-5: 11-15) and severe (IIEF-5: <11). A logistic regression model was used to identify significant independent risk factors for ED.

RESULTS

Overall, 51.3% of respondents (n=374) reported some degree of erectile dysfunction. Of these, 23.2% have mild ED, 8.8% have moderate ED and 19.3% had severe ED. The prevalence of ED increased from 42.8% for men in their forties to 77.4% in their sixties. The prevalence of severe ED increased from 9.1% in men in their forties to 43.5% in their sixties and 77.0% in those aged 70 and above. Age above 50 years is the single most significant risk factor on multivariate analysis when adjusted for all confounding factors. Other important risk factors include Indian ethnic group, lower household income, physical inactivity, diabetes mellitus and cardiac diseases.

CONCLUSION

Erectile dysfunction is common amongst Singaporean men. Age is the single most important physiologic factor affecting erectile function. The prevalence and severity increased significantly with age after 50 years old. With an ageing population, erectile dysfunction may become a significant health problem. Health care providers should plan their resources accordingly.

Comparisons of norcantharidin cytotoxic effects on oral cancer cells and normal buccal keratinocytes

Norcantharidin (NCTD) is the demethylated analogue of cantharidin. In this study, multi-parameter assessments of morphological alterations, clonogenic efficiency, cell growth curves, DNA synthesis, and DNA strand break were employed to determine and compare the cytotoxic effects of NCTD on oral cancer KB cell line and normal buccal keratinocytes. The results showed NCTD induced significant cytotoxicity in KB cells after 24 h of exposure. Normal buccal keratinocytes were more resistant to NCTD induced cytotoxicity. The IC(50) of 24 h NCTD treatment for KB and keratinocytes were 15.06 and 216.29 microg/ml, respectively with a keratinocyte/KB selective index of 14.36. Anoikis and membrane blebbing, morphological characterization of apoptosis, were observed in about 90% of KB cells after exposure to 100 microg/ml of NCTD for 24 h compared to about 30% in keratinocytes. In addition, inhibition of colony formation was noted in KB cells even when exposed to low concentration of drug (5 microg/ml) for a short period of time (6 h). NCTD inhibited subsequent cell proliferation in KB but growth of normal keratinocytes was retarded only temporarily. NCTD inhibited DNA synthesis in both KB and normal keratinocytes. However, keratinocytes were more sensitive to DNA synthesis inhibition by low dose of NCTD. Significant DNA strand break was noted in KB cells only after cell viability was reduced to less than 60% of the control. In comparison, normal keratinocytes were resistant to NCTD induced DNA strand break. These results indicated KB cells were more sensitive to NCTD induced cytotoxicity compared to normal keratinocytes. NCTD may be of value in treating oral cancers. The underlying mechanisms of the differential actions of NCTD on these two cell types are worthy of further investigations.

Pterygium in Indonesia: prevalence, severity and risk factors

AIM

To determine prevalence rates, severity, and risk factors for pterygium in adults in provincial Indonesia and to validate a clinical grading scheme in a population based setting.

METHODS

A population based prevalence survey of 1210 adults aged 21 years and above was conducted in five rural villages and one provincial town in Riau province, Sumatra, Indonesia, an area near to the equator. A one stage household cluster sampling procedure was employed: 100 households were randomly selected from each village or town. Pterygia were graded for severity (T1 to T3, by visibility of episcleral vessels) and the basal and apical extent measured by an ophthalmologist (GG) with a hand held slit lamp. Refraction was measured by hand held autorefractor (Retinomax). Face to face household interviews assessed outdoor activity, occupation, and smoking. The participation rate was 96.7%.

RESULTS

The mean age was 36.6 years (SD 13.1), 612 were male. The age adjusted prevalence rate of any pterygium was 10.0% (95% confidence intervals (CI) 8.2 to 11.7) and of bilateral pterygia was 4.1% (95% CI 2.9 to 5.3). There was a significant dose-response relation with age (2.9% (95% CI 0.4 to 5.8) for 21-29 years versus 17.3% (95% CI 10.4 to 24.2) 50 years and above; p for trend <0.001) and occupations with more time outdoors (p for trend = 0.02). This was true for both sexes, all grades of lesion (T1 to T3), and bilateral disease. A multivariate logistic regression model showed pterygium was independently related to increasing age and outdoor activity 10 years earlier. The mean basal diameter = 3.3 mm (SD 1.51, range 0.1-9.5) and extent from limbus = 1.4 mm (SD 1.18, range 0.1-8.0). Higher grade pterygia were larger for basal and apical extent (p for trend <0.001). The presence of pterygium was associated with astigmatism (defined as cylinder at least -0.5 dioptres (D); p <0.001). This association increased with increasing grade of lesion (p for trend <0.001). Median cylinder for those with pterygium (-0.50 D) was greater than for those without (-0.25D), (p <0.001), and increased with higher grade of lesion (p for trend <0.001). For eyes with pterygia, magnitude of astigmatism was associated with greatest extent from the limbus, (p = 0.03), but not basal width (p = 0.99).

CONCLUSIONS

There is a high prevalence rate of pterygia in provincial Sumatra. The independent increase with age and past outdoor activity (a surrogate for sun exposure) is consistent with previous findings. Clinical grading of pterygium morphology by the opacity of the lesion was a useful additional marker of severity.

Knowledge and practice of breast cancer screening amongst public health nurses in Singapore

AIM OF STUDY

The study aimed to examine the knowledge and practice of breast cancer screening amongst Public Health nurses who are patient educators.

METHOD

A self-administered questionnaire was sent to all 447 nurses in the Public Health Service to assess their knowledge and practice of breast cancer screening. Response rate was 96.4%. Knowledge scores ranged from 0-17 with one point given to a correct knowledge question, zero for wrong answer.

RESULTS

Median knowledge score was nine and 58.3% of nurses scored > or = 9. Statistically significant factors influencing knowledge scores were related to the nursing profession, namely nursing qualifications, current nursing post and current workplace. 76.2% of Nursing Officers/Higher Nursing Officers and 74.5% of midwives had knowledge scores > or = 9 compared with 57.3% of staff nurses and 40.8% of assistant nurses (p < 0.01). 60.1% of nurses who were taught breast-self examination scored > or = 9 (p < 0.05). As for practice, 93.7% of nurses did breast-self-examination, 54.1% had clinical breast examination in the past one year and 50.2% had mammogram done. On multivariate analysis, significant factors affecting practice of clinical breast examination were marital status (Prevalence Rate Ratio 1.94, 95% Confidence Interval 1.20-3.15), doctor's gender (PRR 1.35, CI 1.04-1.75) and those affecting mammogram were age group (PRR 1.78, CI 1.27-2.48), marital status (PRR 1.63, CI 1.03-2.59), history of breast disease (PRR 1.51, CI 1.06-2.16).

CONCLUSIONS

The majority of nurses had certain misconceptions in the knowledge of breast cancer and breast cancer screening. A higher proportion of nurses in the Family Health Service had higher knowledge scores than other nurses in the Public Health Service. Most of the nurses did breast-self-examination. Having ever married and the availability of a female doctor influenced the nurses attending clinical breast examination. Nurses who were > or = 50 years old, ever married and those with a positive history of breast disease were more likely to have mammography done.

Sensitization of a tumor, but not normal tissue, to the cytotoxic effect of ionizing radiation using Panax notoginseng extract

The aim of the present study was to investigate any sensitization effect of the Panax notoginseng extract (PNE) and the purified Saponin (Rb1) on the radiation response of an experimental tumor (KHT sarcoma) in mice, in comparison with any effects on a normal tissue (bone marrow). PNE at a concentration of 0.1-100 mg/kg produced an increase in tumor radiosensitivity. The sensitization effect was maximal at 10 mg/kg and at 30 minutes after injection. Higher doses were toxic to the bone marrow stem cells. Similarly Rb1 at a concentration 0.001 to 1 mg/kg also produced an increase in tumor radiosensitivity, with maximum effect at 1 mg/kg. Higher doses were not toxic to the bone marrow stem cells in this case. Radiosensitization factors were calculated as ratios of D0 (the radiosensitivity parameter), and these were highly significant for the tumor and very similar for both compounds at the doses used, namely 1.18-1.19. There was no significant effect for bone marrow stem cells (sensitization factors of 0.99 +/- 0.01 for both compounds). The differential effect on tumor, and the magnitude of the radiosensitization, suggest that further purified or synthetic versions of this extract may be useful not only in vascular-related diseases but also in cancer therapy.

Effluents from a pulp and paper mill: a skin and health survey of children living in upstream and downstream villages

OBJECTIVES

A health survey of three villages (upstream village Rantau Baru and two downstream villages, Sering and Pelalawan) in the vicinity of a pulp and paper mill along the Kampar river in the province of Riau, Indonesia was conducted to find whether exposure to the effluents from the mill was related to skin conditions and ill health.

METHODS

A cross sectional survey was carried out of children living in the three villages.

RESULTS

Common skin conditions such as dermatitis, fungal infections, insect bites, and miliaria were found. No significantly increased risk of dermatitis or any illness in general was found with increasing levels of exposure to river water for downstream villages when compared with the upstream village. However, there was an increased risk of diarrhoea in Sering especially with drinking water directly from the river (prevalence rate ratio (PRR) 4.9, 95% confidence interval (95% CI) 0.4 to 63.9). An increased risk was also found within the upstream village Rantau Baru (PRR 2.3, 95% CI 0.9 to 5.8) and downstream village Sering (PRR 1.4, 95% CI 0.4 to 5.2) when children who drank water directly from the river were compared with those who never did. Analysis of the river water also showed physical and chemical variables within the acceptable range except for faecal coliforms (6 MPN/100 ml) found in the sample taken from Sering.

CONCLUSIONS

The effluent from the mill is unlikely to be causing skin conditions and ill health. Diarrhoea may be due to faecal coliform contamination of the water because all raw sewerage is deposited in the river. Community health outreach programmes are being implemented based on these findings.

Matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 gene expressions and their differential regulation by proinflammatory cytokines and prostaglandin in nasal polyp fibroblasts

Chronic inflammation of the paranasal sinus leads to nasal polyp (NP) formation. In this study, we investigated the effect of stimulation of the proinflammatory cytokines interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) and prostaglandin (PG) E2 on the production of messenger RNA (mRNA) of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-I (TIMP-1) in nasal polyp fibroblasts (NPFs) and nasal mucosa fibroblasts (NFs). The mRNAs of IL-1alpha, TNF-alpha, MMP-1, and TIMP-1 in 40 surgical specimens of NPs were studied by in situ hybridization to corroborate the in vitro findings. The results indicated a significant amount of constitutive MMP-1 mRNA in NPFs and cytokine-induced MMP-1 steady-state mRNAs in NFs. The effect of stimulation of cytokines on TIMP-1 mRNA synthesis was unremarkable in NPFs and NFs. Exogenous PGE2 enhanced cytokine-stimulated MMP-1 mRNA synthesis in NPFs. In situ hybridization revealed that cells expressing MMP-1 and TIMP-1 mRNAs (primarily plasma cells, fibroblasts, and endothelial cells) gathered around areas with loose stroma, suggestive of rapid extracellular matrix degradation. These data suggest that the pathogenesis of nasal polyposis could be related to production of MMP-1 and consequent promotion of matrix collagenolysis.

Improving relative anisotropy measurement using directional correlation of diffusion tensors

A method employing directional correlation of the diffusion tensor, directional-correlation weighted relative anisotropy (DRA), was developed to improve the accuracy of estimated relative anisotropy (RA). The intravoxel directional correlation was established on the same voxel between two identically acquired diffusion tensor images, and the correlation coefficient derived from tensor dot product was employed as the weighting factor applied in the calculation of RA. The effect of noise influence was reduced since the random noise between repeated scans is not directionally correlated. The RA and the inter- and intravoxel DRA estimations were examined on rat brains in vivo. The background noise alters the direction of eigenvectors and the magnitude of eigenvalues. The dispersion angle between repeatedly obtained eigenvectors, representing the extent of directional alteration of eigenvectors, depends on the tissue anisotropy as well as the signal-to-noise ratio (SNR) of the source images. Current results demonstrate that the intravoxel DRA improves the accuracy of RA estimation, increases the relative contrast of gray and white matter, and avoids the partial volume effect commonly seen in the intervoxel operations.

Comparisons of tumor suppressor p53, p21, and p16 gene therapy effects on glioblastoma tumorigenicity in situ

The mutation and/or deletion of tumor suppressor genes have been postulated to play a major role in the genesis and the progression of gliomas. In this study, the functional expression and efficacy in tumor suppression of 3 tumor suppressor genes (p53, p21, and p16) were tested and compared in a rat GBM cell line (RT-2) after retrovirus mediated gene delivery in vitro and in vivo. Significant reductions in tumor cell growth rate were found in p16 and p21 infected cells (60 +/- 12% vs 66 +/- 15%) compared to p53 (35 +/- 9%). In vitro colony formation assay also showed significant reductions after p16 and p21 gene delivery (98 +/- 5% vs 91 +/- 10%) compared to p53 (50 +/- 18%). In addition, the tumor suppression efficacy were investigated and compared in vivo. Retroviral mediated p16 and p21 gene deliveries in glioblastomas resulted in more than 90% reductions in tumor growth (92 +/- 26% vs 90 +/- 22%) compared to p53 (62 +/- 18%). Tumor suppressor gene insertions in situ further prolonged animal survival. Overall p16 and p21 genes showed more powerful tumor suppressor effects than p53. The results were not surprising, as p16 and p21 are more downstream in the cell cycle regulatory pathway compared to p53. Moreover, the mechanism involved in each of their suppressor effects is different. This study demonstrates the feasibility of using tumor suppressor genes in regulating the growth of glioma in vitro and in situ.

The effect of curing light intensity on the cytotoxicity of a dentin-bonding agent

Various dentin-bonding agents (DBAs) have been widely used to improve the bonding strength of dental resins and to prevent microleakage at the resin-dentin interface, although DBA may exert potentially detrimental effects upon dental pulp. In this study, a DBA (Scotchbond Multi-purpose) cured at different light intensities (100, 200 and 300-mW/cm2) for 10 seconds was extracted with Dulbecco's modified Eagle's medium (DMEM) for 24 hours. Thereafter, pulp cells (1 x 10(4) cells/well) were exposed to DMEM with or without DBA extract for 12 hours, 24 hours and five days. Pulp-cell cytotoxicity was measured with a modified 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. No significant cytotoxicity of DBA eluents on pulp cells was found for the 12-hour exposure group. Following 24-hour exposure of cells to DBA cured at 100-mW/cm2, pulp cells became rounder, more retracted and lost some cellular processes as compared to controls. Five-day exposure of pulp cells to DBA extract cured by light at levels of 100, 200 and 300 mW/cm2, respectively, led to a growth retardation of 26%, 48% and 70% as analyzed by the inhibition of mitochondrial dehydrogenase activity. These results indicate that DBA may exert some cytotoxic effects upon dental pulp, especially when DBA-curing is insufficiently complete, as may occur at a low light intensity.

A population-based prevalence survey of skin diseases in adolescents and adults in rural Sumatra, Indonesia, 1999

Skin disorders are one of the most common presenting health problems and pose a considerable public health problem in developing and developed countries. A population-based survey (n = 917) was conducted in October and November 1999 to determine the prevalence of skin diseases in 3 rural villages in Indonesia (Riau province, Sumatra). The overall individual response rate was 96%. Household interviews were conducted to obtain information on skin conditions, basic socio-demographic factors and lifestyle habits. Trained doctors performed a thorough clinical skin examination of each subject in the household. The overall prevalence of skin disease in the 3 villages was 28.2% (95% confidence intervals 24.6-31.8). The prevalence of fungal infections (12.0%) was twice as high as dermatitis (5.1%). As skin conditions are common in rural Indonesia, it is advisable to improve the training of nurses and doctors in the prevention and treatment of skin disorders.

Hemodynamic effects of Salvia miltiorrhiza on cirrhotic rats

Salvia miltiorrhiza (Sm) administration has been shown to reduce hepatic fibrosis in rats. We investigated the hemodynamic effects of Sm on bile duct ligated (BDL) rats. Hemodynamic, histological, and vascular contractile studies were conducted in rats 4 weeks after bile duct ligation. An aqueous extract of Sm (0.2 g twice per day) or vehicle was administered for 4 weeks to BDL rats. Sm treatment in BDL rats significantly reduced histological grades of fibrosis and ameliorated the portal hypertensive state (including portal venous pressure, superior mesenteric artery blood flow, cardiac index, and total peripheral resistance) as compared with vehicle treatment. Moreover, Sm treatment enhanced the vascular sensitivity of mesenteric arteries to phenylephrine in BDL rats. Sm treatment had no effect on plasma biochemical profiles of either BDL or normal rats. Our results suggest that 4-week Sm treatment ameliorates the portal hypertensive state in BDL rats.

Magnolol, a potent antioxidant from Magnolia officinalis, attenuates intimal thickening and MCP-1 expression after balloon injury of the aorta in cholesterol-fed rabbits

BACKGROUND

Restenosis is a common complication after balloon angioplasty. A number of cytokines, chemotactic factors and growth factors may be involved. Several antioxidants have been shown to inhibit intimal thickening after balloon injury in hyperlipidemic animals.

OBJECTIVES

The effects of magnolol on the expression of monocyte chemotactic protein-1 (MCP-1) and intimal response in balloon injured aorta of cholesterol-fed rabbits were investigated.

METHODS

Male New Zealand white rabbits were fed a 2% high cholesterol (HC) diet together with daily intramuscular injection of either 1 microg/kg B.W. of magnolol (HC-M, n = 10) or vehicle (propylene glycol) as a control (HC-C, n = 10) for a total of 6 weeks. Another 10 rabbits fed a regular diet also served as a control (C) group. A balloon denudation of abdominal aorta was performed in each group at the end of the third week. The aortas were harvested at the end of 6 weeks.

RESULTS

Magnolol treatment significantly inhibited Cu2+-induced LDL oxidation in cholesterol-fed rabbits and reduced atheroma formation [atheroma area ratio: 0.10 +/- 0.03 (HC-M) versus 0.33 +/- 0.07 (HC-C), p < 0.05] in thoracic aortas without lowering serum cholesterol. The intimal response was significantly attenuated in the HC-M rabbits when compared to those of the HC-C group [intimal thickness: 88.95 +/- 14.91 microm (HC-M) versus 198.02 +/- 20.35 microm (HC-C), p < 0.05; intimal area: 278.21 +/- 43.16 x 10(3) microm2 (HC-M) versus 642.70 +/- 65.01 x 10(3) microm2 (HC-C), p < 0.05]. The MCP-1 mRNA and protein expression were reduced in the HC-M group compared to the HC-C and C groups.

CONCLUSION

The inhibitory effects on intimal hyperplasia and MCP-1 expression might be attributed to the antioxidant capacity of magnolol instead of lowering serum cholesterol. Magnolol may offer some protection against postangioplasty restenosis.

Decreased serum IgE level, decreased IFN-gamma and IL-5 but increased IL-10 production, and suppressed cyclooxygenase 2 mRNA expression in patients with perennial allergic rhinitis after treatment with a new mixed formula of Chinese herbs

A new mixed formula of Chinese herbs containing Shin-yi-san + Xiao-qing-long-tang + Xiang-sha-liu-jun-zi-tang by the weight of 9 + 3 + 3 g/day was prescribed for the treatment of patients with perennial allergic rhinitis for 3 months (the composition of each herb is shown in the tables of the article). We classified the patients into high (H-IgE) and low IgE (L-IgE) groups according to the titer of serum total IgE (> 200 KIU/l in H-IgE vs. < 200 KIU/l in L-IgE) and the presence of house dust mite-specific IgE. The nasal symptomatic score in the high IgE group was significantly improved from 7.19 +/- 0.18 before treatment to 2.67 +/- 0.37 after treatment. In addition, the serum total and house dust mite-specific IgE level were also decreased after treatment. For elucidating the working mechanism of the mixed formula, the Th1 (IFN-gamma) and Th2 (IL-4, IL-5, IL-10 and IL-13) cytokine production by phytohemagglutinin (PHA)-stimulated mononuclear cells (2 x 10(6) cells/ml) and cyclooxygenase type 2 (COX-2) mRNA expression in LPS or IL-13-stimulated PMN were compared before and after 3 months of treatment. We found that the mixed formula treatment significantly enhanced IL-10 but decreased IFN-gamma and IL-5 production by PHA-stimulated mononuclear cells. The IL-5 production was also decreased by PHA-stimulated lymphocyte. In addition, the COX-2 mRNA expression in stimulated PMN was significantly suppressed after treatment. These results suggest that the new mixed formula treatment is beneficial to the patients with perennial allergic rhinitis via modulating the function of lymphocytes and neutrophils.

Myopia and night lighting in children in Singapore

AIM

To examine the role of night time lighting and myopia in children in Singapore

METHODS

A cross sectional study was conducted on 1001 children in two Singapore schools. Cycloplegic refraction and A-scan biometry measurements were made in both eyes. A detailed questionnaire was completed by the parents to obtain information on night time lighting, near work activity, educational and demographic factors.

RESULTS

There was no difference in myopia prevalence rates in children exposed to night time light (33.1%) compared with children who slept in the dark (31.4%) before age 2. In addition, vitreous chamber depth was not related to night light (p = 0.58) before age 2. These results remained even after controlling for near work.

CONCLUSION

Myopia is not associated with night light in Asian populations.

Discovery of gemifloxacin (Factive, LB20304a): a quinolone of new a generation

Novel quinolone antibacterials, which bear an alkyloxime substituent in the 4-position and an aminomethyl substituent in the 3-position of the pyrrolidine ring, have been designed and synthesized. These fluoroquinolones were found to possess extremely potent antimicrobial activity against gram-positive organisms including resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). Among these compounds our development candidate, Gemifloxacin (Factive, LB20304a), showed the best in vivo efficacy and pharmacokinetic profile in animals, as well as good safety pharmacological properties. Gemifloxacin was found to be especially effective against respiratory tract infections that account for over 70% of all infections. With once-a-day dosage, potency against respiratory tract infections such as chronic bronchitis and pneumonia was ensured without any significant side effect. In December 1999, Gemifloxacin filed a NDA for marketing approval to the US Food and Drug Administration.

Induction of dental pulp fibroblast matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 gene expression by interleukin-1alpha and tumor necrosis factor-alpha through a prostaglandin-dependent pathway

Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) are involved in the degradation of extracellular matrix in many inflammatory diseases. Little is known regarding the expression of these mediators in dental pulp fibroblasts. The effects of proinflammatory cytokines (interleukin (IL)-1alpha and tumor necrosis factor-alpha (TNF-alpha)) and prostaglandin E2 (PGE2) on pulp fibroblast MMP-1 and TIMP-1 gene expression were investigated. Northern hybridization showed that IL-1alpha and TNF-alpha induced significant MMP-1 gene expression, with only little effect on TIMP-1 gene. Exogenous PGE2, however, upregulated TIMP-1 mRNA synthesis but not MMP-1. Concomitant addition of IL-1alpha and PGE2 or TNF-alpha and PGE2 suppressed MMP-1 mRNA production, compared with the groups treated with IL-1alpha or TNF-alpha alone. In contrast, PGE2 enhanced the upregulatory effects of TIMP-1 mRNA by IL-1alpha or TNF-alpha. Furthermore, cytokine stimulation of MMP-1 and TIMP-1 gene expressions can be enhanced or blocked by indomethacin, respectively, and reversed by exogenous PGE2. These results suggested that cytokine-stimulated MMP-1 and TIMP-1 gene expression in dental pulp fibroblasts was mediated, at least in part, by a prostaglandin-dependent pathway. The differential regulation of IL-1alpha or TNF-alpha-induced MMP-1 and TIMP-1 mRNA synthesis, as well as the direct upregulation of TIMP-1 gene expression by PGE2, also implied that prostaglandin may serve as a protective mechanism from excessive tissue breakdown during pulpitis.

Hemodynamic effects of synephrine treatment in portal hypertensive rats

Synephrine, a sympathomimetic alpha1-adrenoceptor agonist, has been shown to induce dose-dependent portal hypotensive effects after acute intravenous infusion. The present study was undertaken to investigate the hemodynamic effects of 8-day administration of synephrine in portal hypertensive rats. Portal hypertension was induced by either partial portal vein ligation (PVL) or bile duct ligation (BDL). Portal hypertensive rats were allocated into one of two groups: vehicle group (0.1 N HCl, 0.5 ml/12 h) or synephrine group (1 mg/kg per 12 h), with 7 rats in each group. Synephrine or vehicle was administered by gavage into PVL and BDL rats for 8 consecutive days. Systemic as well as splanchnic hemodynamic parameters were measured thereafter. Synephrine significantly ameliorated the hyperdynamic state in both PVL and BDL rats. The portal venous pressure in PVL and BDL rats (-13.5% and -10.1%, respectively), portal tributary blood flow (-19.5% and -20.4%) and cardiac index (-12.1% and -18.8%) were significantly reduced, while mean arterial pressure (10.4% and 23.4%) and systemic (26.3% and 51.0%) as well as portal territory (47.1% and 67.7%) vascular resistance were enhanced by treatment of synephrine as compared with vehicle treatment. Our results showed that eight-day administration of synephrine exerted beneficial hemodynamic effects in two models of portal hypertensive rats.

Norcantharidin-induced post-G(2)/M apoptosis is dependent on wild-type p53 gene

Norcantharidin (NCTD), a synthetic analogue of phosphatase type 2A inhibitors, cantharidin, was shown to have limited effects in treating human and animal tumors. The tumor cell killing mechanisms by norcantharidin, however, remain unclear. In this report, we wished to investigate the mechanisms of norcantharidin-mediated cytotoxicity. Effort was made to investigate whether norcantharidin exerted its cytotoxicity through a p53-dependent or -independent mechanism. RT-2 (wtp53) and U251 (mutant p53) glioblastoma cell lines were exposed to norcantharidin at different dosages. Time-course fluorescent-activated cell sorting (FACS) analysis showed that high doses of norcantharidin arrested the cells at the G(2)/M phase and subsequent post-G(2)/M apoptosis in RT-2 cell line. In comparison, the U251 cell line was found resistant to norcantharidin-induced cytotoxicity. Restoring wild-type p53 gene function in the U251 cell line after adenoviral infections induced tumor cell cytotoxicity after exposure to norcantharidin. These results showed that norcantharidin kills tumor cells efficiently corresponding to their endogenous p53 gene status. The results also showed the feasibility of using adenoviral p53 gene therapy to enhance chemosensitivity of tumor cells to norcantharidin.

Induction of the c-jun protooncogene expression by areca nut extract and arecoline on oral mucosal fibroblasts

To investigate the mechanisms of areca quid (AQ)-induced carcinogenesis, expression of c-fos and c-jun protooncogenes was examined in human oral mucosal fibroblasts after exposure to areca nut extracts (ANE) or arecoline. We found that treatment of cells with 200 microg/ml ANE or 10 microg/ml arecoline for 1 h induced about three-fold increase in c-jun mRNA levels. This increase was transient and the level of c-jun mRNAs returned rapidly to control levels thereafter. However, ANE and arecoline did not induce c-fos mRNA expression at detectable levels. During AQ chewing, oral mucosal cells are continuously stimulated by ANE and arecoline. Persistent induction of the c-jun protooncogene by ANE and arecoline may be one of the mechanisms in the carcinogenesis of oral squamous cell carcinoma in Taiwan. Furthermore, we observed that pre-incubation of cells with either N-acetyl-cysteine [a glutathione (GSH) precursor] or L-buthionine-S,R-sulfoximine (a specific inhibitor of GSH biosynthesis) had a minimal effect on arecoline-induced c-jun expression. Therefore, arecoline-induced c-jun expression is independent of GSH depletion.

Urinary protein excretion in Type 2 diabetes with complications

This study examined the association between urinary markers of early diabetic nephropathy and non-renal diabetic complications in 946 patients with type 2 diabetes mellitus. The association with hypertension was also studied. Data on macrovascular complications (ischaemic heart disease, stroke, peripheral vascular disease) and microvascular complications (retinopathy, peripheral neuropathy) were obtained from case records and clinical examination. Urine samples collected were analysed for albumin, beta(2)-microglobulin, retinol-binding protein (RBP), and N-acetyl-beta-D-glucosaminidase (NAG). Results showed that urinary albumin, RBP and beta(2)-microglobulin levels were higher in patients with macro- and/or microvascular complications, compared to those without. NAG levels were higher only in patients with both types of complications. A higher proportion of patients with complications had abnormally raised urinary protein and enzyme levels, compared to those without. Patients with associated hypertension had higher urinary levels of albumin and beta(2)-microglobulin, regardless of whether complications were present or not. RBP excretion was, however, markedly higher only in patients with microvascular complications, whereas hypertension did not influence NAG excretion. Urine albumin and RBP excretion were predictive of microvascular, as well as both macrovascular and microvascular complications, whereas NAG excretion was predictive of macro- and microvascular complications. These findings could mean that increased urinary protein and enzyme excretion were associated with more severe disease in these patients.

Intravenous pretreatment with magnolol protects myocardium against stunning

Magnolol, an antioxidant, has been reported to possess various protective effects on the cardiovascular system. However, its effect on myocardial stunning has not been elucidated. The purpose of this study was to investigate the antistunning effect of magnolol by evaluating the recovery of regional myocardial function after 10-minute coronary artery occlusion in anesthetized, open-chest rabbits. There was no significant hemodynamic change after intravenous infusion of magnolol. Systolic wall thickening fraction (WThF) measured with an epicardial Doppler sensor in animals pretreated with normal saline and vehicle solution remained significantly depressed (60 +/- 7% and 77 +/- 4% of baseline WThF, respectively) 3 hours after coronary artery reperfusion (CAR). Pretreatment with magnolol (10(-7) and 10(-6) g/kg, intravenous infusion) significantly enhanced the recovery of systolic wall thickening fraction (98 +/- 1 and 99 +/- 1% of baseline WThF, respectively) 60 minutes after CAR. This study demonstrated that intravenous pretreatment with magnolol protected myocardium against stunning.

Effect of magnolol on coronary vascular resistance in rabbits: measurement with pulsed Doppler velocimetry

BACKGROUND AND PURPOSE

Magnolol is an active component purified from Magnolia officinalis that has been reported to protect the myocardium against infarction and reperfusion injury. The purpose of this study was to investigate the effect of magnolol on the coronary circulation and to determine whether a change in coronary vascular resistance could be the mechanism underlying its myocardial protective effect.

METHODS

Male New Zealand white rabbits were anesthetized. A 3-mm suction-type pulsed Doppler velocimetry probe was applied to the proximal part of the left anterior descending coronary artery after median sternotomy. The 39 rabbits received intravenous injection of either vehicle (n = 5), magnolol (10(-6) g/kg, n = 6; 10(-5) g/kg, n = 5; 10(-4) g/kg, n = 5), or nitroglycerin (10(-5) g/kg, n = 6; 10(-4) g/kg, n = 6; 10(-3) g/kg, n = 6). The effects of magnolol and nitroglycerin on coronary vascular resistance were compared.

RESULTS

Magnolol did not change blood pressure or coronary blood flow velocity. However, at a dose of 10(-4) g/kg, it decreased coronary vascular resistance significantly more than vehicle (88 +/- 1% vs 95 +/- 1% of baseline coronary vascular resistance, p < 0.001). Nitroglycerin increased coronary blood flow velocity and decreased coronary vascular resistance in a dose-dependent manner (p < 0.01).

CONCLUSIONS

Magnolol reduced coronary vascular resistance in anesthetized, open-chest rabbits only at a high concentration. Its effect was modest compared with that of nitroglycerin. Since magnolol protects the myocardium at relatively low doses, coronary vasodilatation is unlikely to be the underlying mechanism responsible for its myocardial protective effects.

Urine protein excretion among Chinese patients with type 2 diabetes mellitus

BACKGROUND

Urinary excreton of low molecular weight proteins such as beta2-microglobulin and retinol binding protein (RBP), and enzymes such as N-acetyl-beta-D-glucosaminidase (NAG), may be useful as indicators of renal tubular dysfunction in diabetes mellitus.

OBJECTIVE

To describe the profile of urinary protein and enzyme excretion in 240 Chinese patients with type 2 diabetes mellitus in Singapore.

MATERIALS AND METHODOLOGY

Cross-sectional study of consecutive patients presenting for follow-up at a Government primary care clinic. Information was obtained from interview, physical examination and laboratory analysis. Data analysis included descriptive statistics on urinary protein and enzyme excretion, comparison of unadjusted and adjusted means of these among patient subgroups, as well as correlation with control of diabetes and other clinical parameters.

RESULTS

Albuminuria correlated with urine beta2-microglobulin (r=0.34, p<0.01) and RBP (r=0.46, p<0.01). Hypertensive patients had significantly higher mean urine albumin (geometric mean 15.13 mg/gCr) and beta2-microglobulin (363.18 microg/gCr) levels compared to patients without hypertension (7.07 mg/gCr; 219.20 microg/gCr; p<0.05). Patients with complications of diabetes also had higher albumin (15.55 vs 6.20 mg/gCr), beta2-microglobulin (344.47 vs 288.83 microg/gCr) and RBP excretion (152.02 vs 94.54 mg/gCr). Two-hour postprandial sugar correlated with beta2-microglobulin (r=0.33, p<0.01), RBP (r=0.35, p<0.01) and NAG (r=0.28, p<0.01). Urinary protein excretion did not correlate with HbA1c, fasting blood sugar, age of patient or duration since diagnosis.

CONCLUSION

These results among 240 Chinese patients in Singapore were consistent with reports from other study populations.

Immunolocalization of macrophages and transforming growth factor-beta 1 in induced rat periapical lesions

Apical periodontitis was induced in Wistar rats by exposing the pulp chamber of right mandibular first molars to the oral environment. Animals were killed 0, 5, 10, 15, 20, 30, 60, and 80 days after lesion induction. Microradiographic and automated image analysis showed that the lesions expanded significantly in a time-dependent manner from day 0 to day 20 (0.039 mm2/day, p < 0.05, active phase) and stabilized thereafter (chronic phase). A linear regression test revealed a positive correlation between the numbers of ED-1 positive macrophage per microscopic high power field and the periapical lesion size during the active phase (r = 0.98, p < 0.01). Immunohistochemical studies showed that transforming growth factor-beta 1 positive macrophages distributed around the root apex and areas showing bone resorption during active lesion phase, whereas TGF-beta 1-positive osteoblasts were detected during the chronic stage (days 30, 60, and 80 after pulp exposure). Histologically TGF-beta 1 positive osteoblasts possessed a large, round nucleus as well as an abundant cytoplasm and located in close vicinity to areas exhibiting reparative bone formation. These results suggest that macrophages may play important role(s) in the initiation and development of periapical lesions and TGF-beta 1 may play dual roles in both bone resorption and deposition in induced rat periapical lesions.

Direct liquid chromatographic enantiomer separation of new fluoroquinolones including gemifloxacin

The enantiomers of gemifloxacin mesylate (formerly LB20304a), a new fluoroquinolone compound with potent in vitro and in vivo antibacterial profile were resolved on a commercially available Crownpak CR chiral stationary phase (CSP). All of the fluoroquinolones, including gemifloxacin used in this study, were well enantioseparated on Crownpak CR(+) column. These results are the first reported for the direct separation of the enantiomers of quinolones on chiral crown ether coated Crownpak CR CSP. The behavior of chromatographic parameters by the change of mobile phase additives for the resolution of gemifloxacin was investigated. Also, the effect of structural change of gemifloxacin on chiral recognition was described.

Expression of p16(INK4A) induces dominant suppression of glioblastoma growth in situ through necrosis and cell cycle arrest

Tumor suppressor genes may represent an important new therapeutic modality in the treatment of human glioblastoma (GBM). p16(INK4A) is a tumor suppressor gene with mutation and/or deletion found in many human tumors, including glioblastomas, melanoma, and leukemias. RT-2 rat GBM cell line was used to investigate if the p16 gene induces dominant suppression of glioblastoma growth. Close to 100% of tumor cells were infected by high titer pCL retrovirus encoding the full-length human p16 cDNA at 5 m.o.i. Infected cells showed a 98% reduction in colony forming assay and a 60% reduction in growth curves in vitro compared to vector control. Exogenous overexpression of p16 induced hypophosphorylation of Rb protein by Western blot analysis. Intracranial injection of p16-infected tumor cells into syngeneic rats resulted in a 95% reduction in tumor volume compared to the controls. Intratumoral injection of p16 retrovirus resulted in tumor necrosis and prominent human p16 transgene expressions. Proliferation marker PCNA was not detected in these human p16-expressed RT-2 tumor cells, suggesting the cells were unable to enter into S phase after p16 expression. In addition, direct repeat intracranial injections of p16 retrovirus prolonged animal survival 3.2-fold compared to the controls (48.4 +/- 13.4 vs 15.0 +/- 2.1 days, p < 0.001). Two out of ten rats were found with dormant tumors at day 60 after p16 retrovirus injection. These results showed that p16 is effective in inhibiting GBM growth in situ. The mechanisms of tumor growth reduction and necrosis in vivo might be due to G1 arrest triggered by p16 expression.

5-Arylamino-2-methyl-4,7-dioxobenzothiazoles as inhibitors of cyclin-dependent kinase 4 and cytotoxic agents

5-Arylamino-2-methyl-4,7-dioxobenzothiazoles were synthesized as inhibitors of cyclin-dependent kinase 4 (CDK4) and cytotoxic agents. Most of the 4,7-dioxobenzothiazoles exhibited selective inhibitory activities for the CDK4 and cytotoxic potential against human cancer cell lines.

Synthesis and antibacterial activity of new carbapenems containing isoxazole moiety

The synthesis and biological activity of a series of new 1beta-methylcarbapenems 1a-g containing 5'-isoxazolopyrrolidin-3'-ylthio derivatives as C-2 side chain are described. Most compounds exhibited potent and well-balanced antibacterial activity as well as high stability to DHP-I comparable to that of meropenem. 1e and 1c showed the best combination of antibacterial activity and stability to DHP-I, respectively.

Magnolol attenuates peroxidative damage and improves survival of rats with sepsis

Reactive oxygen species and peroxidative damage are implicated in the pathophysiology of sepsis. Magnolol is a compound extracted from the Chinese medicinal herb Magnolia officinalis and has multiple pharmacological effects, notably antioxidant functions. To determine whether magnolol can modulate the course of sepsis, survival rate and biochemical parameters were analyzed in rats with sepsis with various treatment protocols. Magnolol at doses ranging from 10(-9) g/kg to 10(-5) g/kg was administered either before or after induction of sepsis by cecal ligation and puncture. Magnolol did not modulate the course of sepsis induced by two cecal punctures. When one cecal puncture was performed, a moderately evolving type of sepsis was induced, and the survival rate of affected rats was significantly improved by pretreatment with 10(-7) g/kg magnolol. The beneficial effect was partially retained if magnolol was administered 6 hours after onset of sepsis when a higher dose (10(-5) g/kg) was used. The intensity of lipid peroxidation in plasma, liver, and lung of septic rats was also attenuated in a treatment-dependent manner. Magnolol at this dose range exerted these beneficial effects probably through its antioxidant efficacy. These significant results may suggest magnolol as a candidate agent for the treatment of sepsis.

Trilinolein potentiates the pro-aggregating effect of phorbol-12-myristate 13-acetate in human polymorphonuclear leukocytes

Trilinolein, a triacylglycerol with linoleic acid as the only type of fatty acid residue in all three of the glycerol esterified positions, was recently reported to have an antiplatelet effect, mediated through stimulating nitric oxide and cyclic guanosine monophosphate (GMP) formation. In our study, trilinolein induced aggregation of human polymorphonuclear neutrophils (PMNs) and, pretreatment with 0.1 nM trilinolein enhanced phorbol-12-myristate 13-acetate (PMA) induced aggregation. Further investigation showed that trilinolein at concentrations ranging from 0.1 nM to 10 microM increased cyclic GMP formation after 10 min of incubation with PMNs. Pretreatment of trilinolein with 10 microM d-sphingosine, before being incubated with PMNs, attenuated the stimulatory effect of trilinolein on cyclic GMP formation, and pretreatment of 10 microM d-sphingosine also attenuated the aggregation induced by PMA and trilinolein. We conclude that trilinolein can induce the aggregation of human PMNs, and enhance the aggregation induced by PMA.

Antiarrhythmic effect of magnolol and honokiol during acute phase of coronary occlusion in anesthetized rats: influence of L-NAME and aspirin

This study was designed to evaluate the in vivo effect of magnolol and honokiol on the acute phase of coronary ligation in the presence of nitric oxide inhibitor (L-NAME) or cyclooxygenase inhibitor (aspirin). After Sprague-Dawley rats were anesthetized with urethane, the changes of ventricular arrhythmia induced by coronary ligation for 30 min were determined with or without pretreatment with study medications. The incidence and duration of ventricular arrhythmia were significantly reduced after intravenous pretreatment (15 min before coronary ligation) with 10(-7) g/kg magnolol or 10(-7) g/kg honokiol. However, the antiarrhythmic effect of magnolol or honokiol could be abolished with the pretreatment of 1 mg/kg L-NAME, but not with pretreatment of 100 mg/kg aspirin. The abolishment of the myocardial beneficial effect of magnolol and honokiol by L-NAME, instead of aspirin, suggests an involvement of an increased nitric oxide synthesis in the protection offered by magnolol and honokiol against arrhythmia during myocardial ischemia.