We use model five-level systems to study resonance leaking of pi-pulse-induced multiphoton (MP) transitions along a strongly coupled anharmonic ladder. We demonstrate that the presence of a weakly bound background state attached to the ladder either in linear or Lambda configuration can have very pronounced effects on resonant MP ladder transitions, including essentially complete quenching of the primary transition. We also develop control strategies for the elimination of background state population based on phase-adjusted Gaussian pulse pairs and discuss the underlying control mechanisms. Finally we show that these strategies are effective in realistic molecular many-level systems. In particular, we demonstrate efficient pulse-pair control of resonance leaking in a 165-level system modeling vibrational excitation in HCN.
Six papaya samples showing downward leaf curling were collected in Guangdong and Guangxi provinces, China. The result of TAS-ELISA showed they were all infected by geminiviruses. Comparison of partial DNA-A sequences reveals that these virus isolates can be classified into two groups. Group I includes isolates G2, G4, G5, G28 and G29 from Guangxi province, while isolate GD2 from Guangdong province belongs to Group II. The complete DNA-A sequence of G2 and GD2 were characterized. Sequence comparisons showed that the DNA-A of G2 and GD2 were most closely related to that of Ageratum yellow vein China virus- [Hn2] and Ageratum yellow vein virus , respectively, with 83.4 and 75.2% nucleotide sequence identity, while DNA-A sequence between G2 and GD2 had only 73.4% sequence identity. The molecular data suggests that G2 and GD2 are two distinct begomoviruses, for which the name Papaya leaf curl China virus (PaLCuCNV) for G2 and Papaya leaf curl Guangdong virus (PaLCuGDV) for GD2 are proposed. Comparison of individual encoded proteins showed the coat protein of G2 and GD2 shared highest amino acid sequence identity (97.7 and 94.2%, respectively) with that of Pepper leaf curl virus -[Malaysia] (PepLCV-[MY]), suggesting the CP of these viruses may have identical ancestor.
The concentration of vitamin E isomers, namely, alpha-tocopherol (alpha-T), alpha-tocotrienol, gamma-tocotrienol, and delta-tocotrienol in palm mesocarp at 4, 8, 12, 16, and 20 wk after anthesis (WAA) were quantified using HPLC coupled with fluorescence detection. alpha-T was detected throughout the palm fruits' maturation process, whereas unsaturated tocotrienols were found only in ripe palm fruits. These developmental results indicate that tocotrienols are synthesized between 16 and 20 WAA.
This study adopts Differential Scanning Calorimetry (DSC) to analyze the thermal properties of samples (2.5-4.0 mg) from the tip, middle, and base sections of individual paracetamol suppositories, which were sampled carefully using a stainless steel scalpel. The contents of paracetamol present in the samples obtained from these sections were determined from the enthalpies of fusion of paracetamol and expressed as % w/w paracetamol to allow comparison of the amount of paracetamol found in each section. The tip, middle, and base sections contained 10.1+/-0.2%, 10.1+/-0.2%, and 10.3+/-0.2% w/w paracetamol, and are statistically similar (One-way anova; p>0.05). This indicates that the preparation technique adopted produces high quality suppositories in terms of content uniformity. The contents of paracetamol in the 120-mg paracetamol suppositories determined by DSC and UV spectrophotometry were statistically equivalent (Students's t-test; p>0.05), 120.8+/-2.6 mg and 120.8+/-1.5 mg, respectively, making DSC a clear alternative method for the measurement of content of drug in suppositories. The main advantages of the method are that samples of only 2.5-4.0 mg are required and the procedure does not require an extraction process, which allows for the analysis to be completed rapidly. In addition, it is highly sensitive and reproducible, with the lower detection limit at 4.0% w/w paracetamol, which is about 2.5 times lower than the content of paracetamol (10% w/w) present in our 120-mg paracetamol suppositories and commercial paracetamol suppositories, which contained about 125 mg paracetamol. Therefore, this method is particularly suited for determination of content uniformity in individual suppositories in quality control (QC) and in process quality control (PQC).
MeSH terms: Acetaminophen/administration & dosage; Acetaminophen/analysis*; Calorimetry, Differential Scanning; Chemistry, Pharmaceutical; Drug Compounding; Quality Control; Spectrophotometry, Ultraviolet; Suppositories; Temperature; Reproducibility of Results; Transition Temperature
Percolation theory has been used with great interest in understanding the design and characterization of dosage forms. In this study, work has been carried out to investigate the behavior of binary mixture tablets containing excipients of similar and different deformation properties. The binary mixture tablets were prepared by direct compression using lactose, polyvinyl chloride (PVC), Eudragit RS 100, and microcrystalline cellulose (MCC). The application of percolation theory on the relationships between compactibility, Pmax, or compression susceptibility (compressibility), gamma, and mixture compositions reveals the presence of percolation thresholds even for mixtures of similar deformation properties. The results showed that all mixture compositions exhibited at least one discreet change in the slope, which was referred to as the percolation threshold. The PVC/Eudragit RS100 mixture compositions showed significant percolation threshold at 80% (w/w) PVC loading. Two percolation thresholds were observed from a series of binary mixtures containing similar plastic deformation materials (PVC/MCC). The percolation thresholds were determined at 20% (w/w) and 80% (w/w) PVC loading. These are areas where one of the components percolates throughout the system and the properties of the tablets are expected to experience a sudden change. Experimental results, however, showed that total disruption of the tablet physical properties at the specified percolation thresholds can be observed for PVC/lactose mixtures at 20-30% (w/w) loading while only minor changes in the tablets' strength for PVC/MCC or PVC/Eudragit RS 100 mixtures were observed.
Little is known about the spatial and temporal distribution of blast fishing which hampers enforcement against this activity. We have demonstrated that a triangular array of hydrophones 1 m apart is capable of detecting blast events whilst effectively rejecting other sources of underwater noise such as snapping shrimp and nearby boat propellers. A total of 13 blasts were recorded in Sepangor bay, North of Kota Kinabalu, Sabah, Malaysia from 7th to 15th July 2002 at distances estimated to be up to 20 km, with a directional uncertainty of 0.2 degrees . With such precision, a network of similar hydrophone arrays has potential to locate individual blast events by triangulation to within 30 m at a range of 10 km.
Cervical spine injuries such as subluxation and fracture dislocation have long been known to result in severe consequences, as well as the trauma management itself. The injury to the region has been identified as one of the major causes of death in Malaysian motorcyclists involved in road crashes, besides head and chest injuries (Pang, 1999). Despite this, cervical spine injury in motorcyclists is not a well-studied injury, unlike the whiplash injury in motorcar accidents. The present study is a retrospective study on the mechanisms of injury in cervical spine sustained by Malaysian motorcyclists, who were involved in road crash using an established mechanistic classification system. This will serve as an initial step to look at the cervical injuries pattern. The information obtained gives engineer ideas to facilitate design and safety features to reduce injuries. All cervical spine injured motorcyclists admitted to Hospital Kuala Lumpur between January 1, 2000 and December 31, 2001 were included in the present study. Based on the medical notes and radiological investigations (X-rays, CT and MRI scans), the mechanisms of injuries were formulated using the injury mechanics classification. The result shows that flexion of the cervical vertebrae is the most common vertebral kinematics in causing injury to motorcyclists. This indicates that the cervical vertebrae sustained a high-energy loading at flexion movement in road crash, and exceeded its tolerance level. The high frequency of injury at the C5 vertebra, C6 vertebra and C5-C6 intervertebral space are recorded. Classification based on the Abbreviated Injury Scale (AIS) is made to give a view on injury severity, 9.1% of the study samples have been classified as AIS code 1, 51.5% with AIS 2 and 21.2% with AIS 3.
A total of 157 stool samples were examined for Group A rotaviruses in diarrheic children admitted to 8 different major hospitals in Malaysia. The overall incidence rate in this study was 19.7% (31 of 157) with a variation of 9.5% to 39.1% in different locations. Majority of the infections detected were in those under 2 years of age and there were fewer admissions in the older age group. The stool samples were initially screened for rotavirus Group A by latex agglutination method and followed by RNA electrophoresis. The size and the characteristics wheel-shaped morphology of the viral preparations when examined by electron-microscopy further confirmed the presence of rotaviruses in the positive stool samples. Analysis of the RNA pattern showed that majority of the isolates, 51.6% (16 of 31) were Type IIC ('long' with comigration of RNA segments 7 and 8), 35.5% (11 of 31) with Type IIG ('long' with comigration of segments 7, 8, 9), 9.7% (3 of 31) with Type IG ('short' with comigration of RNA segments 7, 8, 9) and 3.2% (1 of 31) of mixed or atypical pattern. It appeared that over a 12 year interval, only one new or unusual rotavirus electropherotype was found. This is the first comprehensive report on the electropherotypes of rotaviruses covering eight different geographical locations in Malaysia and the data obtained is useful for understanding the geographic distribution and types of rotaviruses transmitting in Malaysia.
Non-accidental head injury leading to massive intracranial trauma has been identified as a leading cause of death in small children. In a typical case, a child usually below the age of one year is violently shaken, leading to rupture of the connecting veins between the dura mater and the brain substance with variable degrees of bleeding into the subdural space resulting in increased intracranial pressure. The accompanying venous thrombosis affecting the vessels of the brain substance leads to cerebral hypoxia and cellular death. In this study conducted throughout the year 1999, all children below the age of 3 years who were admitted to Hospital Kuala Lumpur and had died due to non-accidental injuries were included. Postmortems, including histopathological studies, were conducted to determine the most likely mechanisms of the injuries. Ten cases were identified for the whole year. In 2 cases, both below one year of age, the features presented showed evidence of violent shaking of the infants. In 6 other cases whose average age was 13 (range 4-24) months, there were evidences of direct trauma and violent shaking. In the last two cases, aged 24 and 33 months respectively, there was only evidence of direct trauma on the heads without being shaken. This study shows that death due to intracranial trauma caused by shaking with or without direct impact is the most frequent cause of mortality in abused children. Death due to direct impact between the head and another object is a less frequent occurrence.
The present study was designed to explore the relationship between lipid peroxidation and antioxidant enzymes in young Malaysian insulin dependant diabetes mellitus (IDDM) patients. Indicative parameters of lipid peroxidation, activities of antioxidant enzymes and diabetes parameters were evaluated in single blood samples from 30 young type 1 diabetic patients and 30 healthy control subjects. Antioxidant enzymes namely superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were significantly decreased while plasma malondialdehyde (MDA), an indicator for lipid peroxidation was significantly increased in IDDM patients compared to control subjects. Positive correlations between HbA1c and MDA; fasting blood glucose (FBG) and MDA and negative correlations between HbA1c and SOD; MDA and SOD were observed in these patients. No significant correlation existed between HbA1c and fasting blood glucose, GPx or CAT in the diabetic patients. The strong correlations found between lipid peroxidation, antioxidant enzymes and diabetes parameters confirms the existence of oxidative stress in our IDDM patients.
MeSH terms: Adult; Analysis of Variance; Antioxidants/metabolism*; Diabetes Mellitus, Type 1/blood*; Diabetes Mellitus, Type 1/complications*; Female; Humans; Malaysia; Male; Lipid Peroxidation*; Case-Control Studies; Oxidative Stress*
Otosclerosis is an autosomal dominant disease affecting the otic capsule. It is believed to be rare in Asian countries including Malaysia. We analyzed the results of 29 patients (35 ears) who had undergone stapes surgery for suspected otosclerosis from January 1996 to June 2002. The demographic data was analyzed. The procedure most commonly performed was stapedotomy. The closure of air bone gap after surgery was good at 2 kHz and 4 kHz compared to frequency below 2 kHz. Closure of air bone gap to within 10 dB was achieved in 74.3%. About 7.5% of our patients did not gain in average air conduction. The outcome of the procedure is comparable to those reported by authors who used the same evaluation criteria. No serious complications occurred in our patients.
The study was conducted to determine whether the clinical targets for the control of diabetes recommended by American Diabetes Association can be met in the context of routine diabetes practice. This cross-sectional study was undertaken on 211 type 2 diabetic patients at the Outpatients Diabetes Clinic, Hospital Universisti Sains Malaysia (HUSM) Kubang Kerian, Kelantan between the year 2001-2002. Patients' physical examination and their medical history as well as their family history were obtained by administering a structured questionnaire. Samples of patients' venous blood during fasting were taken and analysed for plasma glucose, glycated haemoglobin and lipid profile. Analysis showed that many patients had comorbidities or complications. A large number of them had poor glycaemic control (73%). Systolic and diastolic blood pressures of 75% and 85% subjects were > or = 130 and > or = 80 mmHg, respectively. Body Mass Index (BMI) values of 66% of the patients were outside the clinical target (BMI > or = 25 in male and > or = 24 kg/m2 in female). The lipid profile showed that 96% of the patients had at least one lipid value outside the clinical target level. In this study, 70% of the patients had total cholesterol > or = 5.2 mmol/L, 87% had LDL cholesterol > or = 2.6 mmol/L, 57% had HDL cholesterol less than the normal range, < or = 1.15 mmol/L in men and < or = 1.4 mmol/L in women, while 46% had triglycerides > or = 1.71 mmol/L. Complications of diabetes were observed in 48% of the total number of patients. As for the patients' systolic blood pressure, age and duration of diabetes were found to have significant effects. Older subjects with a longer duration of diabetes were more hypertensive. Variables that had significant effects on BMI were age, duration of diabetes, glycaemic control and gender. Younger females and newly diagnosed subjects with better glycaemic control (A1C < 7%) were found to have higher BMI values. The overall clinical targets were suboptimal. The prevalence of hyperlipidaemia and hypertension was high. It is imperative that better treatment strategies and methods be adopted to enhance diabetes control and reduce long-term complications of the disease.
Study site: Outpatients Diabetes Clinic, Hospital Universisti Sains Malaysia (HUSM)
Diabetes mellitus is an important coronary artery disease risk factor. The presence of microalbuminuria, which indicates renal involvement in diabetic patients, is associated with an increased cardiovascular risk. There are suggestions that diabetic patients with microalbuminuria have more adverse risk profile such as higher ambulatory blood pressure and total cholesterol levels to account for the increased cardiovascular morbidity and mortality. QT dispersion is increasingly being recognized as a prognostic factor for coronary artery disease and sudden death. Some studies have suggested that QT dispersion is an important predictor of mortality in Type II diabetic patients. Our cross sectional study was to compare the QT dispersion and 24 hour ambulatory blood pressure monitoring between diabetic patients with microalbuminuria and those without microalbuminuria. Diabetic patients with overt coronary artery disease were excluded from the study. A total of 108 patients were recruited of which 57 patients had microalbuminuria and 51 were without microalbuminuria. The mean value of QT dispersion was significantly higher in patients with microalbuminuria than in patients without microalbuminuria (58.9 +/- 27.9 ms vs. 47.1 +/- 25.0 ms, p < 0.05). The mean 24 hour systolic and diastolic blood pressures were significantly higher in patients with microalbuminuria than in patients without microalbuminuria (129.5 +/- 12.3 mm Hg vs 122.3 +/- 10.2 mm Hg, p < 0.05 and 78.4 +/- 6.9 mm Hg vs 75.3 +/- 6.8 mm Hg, p < 0.05, respectively). Our study suggests that QT dispersion prolongation, related perhaps to some autonomic dysfunction, is an early manifestation of cardiovascular aberration in diabetic patients with microalbuminuria. The higher blood pressure levels recorded during a 24-hour period min diabetics with microalbuminuria could also possibly account for the worse cardiovascular outcome in this group of patients.
A study was done on 76 suicide cases managed by the Forensic Pathology Department of Hospital Kuala Lumpur (HKL) from January till December 1999 to explore the pattern of suicide and psychiatric history. The Chinese contributed 52% (n=40) of cases followed by the Indians (29%, n=22) and the Malays (12%, n=9). After the age of sixty, 84.6% of the subjects were Chinese. The common methods of suicide were poisoning (39%), hanging (34%) and jumping from height (22%). Four out of 12 case-notes traced had documented psychiatric history i.e. schizophrenia.
There is a general lack of valid tools to measure work stress of Malaysian. This study examines the validity and reliability of the Pressure Management Inventory (PMI). Reliability was evaluated using test retest method, and its correlation coefficient was calculated using Pearson's r. Internal consistencies were examined using Cronbach's Alpha. For precision, the Intraclass coefficients (ICC) were calculated for all the scales. Face Validity and Content Validity were assessed using an open-ended questionnaire on 6 content experts (psychiatrists in HKL). The results show good internal consistencies (alpha < or = 0.7) for most subscales, with the best results in the 'Pressure Scale'. The weak scales are 'Individual-Differences' scale and 'Social Support' scale. The test-retest correlation coefficients were significant at the level of p<0.001 for all, except one scale. The ICC coefficients were high (>0.7) for most scales, particularly for Pressure, Health and Coping Scales. The PMI is a suitable, reliable and valid tool to measure stress of Malaysians. More in-depth study with a wider sampling needs to be carried out to add confidence of its usage on Malaysians.
MeSH terms: Adolescent; Adult; Female; Humans; Malaysia/epidemiology; Male; Occupational Diseases/diagnosis*; Occupational Diseases/epidemiology; Psychiatric Status Rating Scales/standards*; Surveys and Questionnaires; Stress, Psychological/diagnosis*; Stress, Psychological/epidemiology; Reproducibility of Results
The aim of this study was to determine the prevalence of psychological stress among medical students and to identify its symptoms and association with depression. A cross-sectional study design was used. Three-hundred and ninety-six medical students at a university in Malaysia were included in the study. Tools similar to the General Health Questionnaire (GHQ-12) and Beck Depression Inventory (BDI) were used to screen for psychological stress and depression, respectively. 41.9% of the medical students were found to have psychological stress, which was significantly associated with depression (chi2=4.636, df=1, p<0.05). Psychological stress is common among medical students and is associated with depression.
A community based cross-sectional study was carried out to determine the prevalence and causes of visual impairment and blindness in residents aged forty years and above in kampung Jenderam Hilir of Sepang district, Selangor state. A total of 311 out of 341 (91.3%) respondents participated in this study. The prevalence of visual impairment and blindness observed was 18.9% and 2.9% respectively. The prevalence of visual impairment and blindness increased significantly with age. Amongst the 159 respondents who agreed for eye checkup, refractive errors (56%), cataract (20.1%), glaucoma (4.4%) and diabetic retinopathy (1.3%) were found to be causing visual impairment and blindness.
Background: There has been no published study of biopsy proven childhood glomerulonephritis in Malaysia.
Objectives: To determine the pattern of childhood glomerulonephritis in Johor, Malaysia from a histopathological perspective and the various indications used for renal biopsy in children.
Materials and methods: Retrospective study was done of all renal biopsies from children under 16 years of age, received in Sultanah Aminah Hospital, Johor between 1994 and 2001. The histopathological findings were reviewed to determine the pattern of biopsy proven glomerulonephritis. The indications of biopsy, mode of therapy given after biopsy and the clinical outcome were studied.
Results: 123 adequate biopsies were received, 9 children had repeated biopsies. Of the 113 biopsies, minimal change disease formed the most common histopathological diagnosis (40.7%) while lupus nephritis formed the most common secondary glomerulonephritis (23.0%). The main indications for biopsy were nephrotic syndrome (50.8%), lupus nephritis (25.4%) and renal impairment (13.1%). The mode of therapy was changed in 59.8% of the children. Of 106 patients followed up, 84 children were found to have normal renal function in remission or on treatment. 4 patients developed chronic renal impairment and 16 reached end stage renal disease. Five of the 16 children with end stage disease had since died while 11 were on renal replacement therapy. another 2 patients died of other complications.
Conclusions: The pattern of childhood GN in our study tended to reflect the more severe renal parenchymal diseases in children and those requiring more aggressive treatment. This was because of our criteria of selection (indication) for renal biopsy. Renal biopsy where performed appropriately in selected children may not only be a useful investigative tool for histological diagnosis and prognosis but may help clinicians plan the optimal therapy for these children.
Breast cancer is one of the commonest cancers among women in Malaysia. The relation between lifestyle practices and the risk of breast cancer in Chinese women aged 21-55 years were assessed using data collected from June to October 2001, via a face-to face interview in a case control study in the Breast Clinics of Kuala Lumpur Hospital and University Malaya Medical Centre. A total of 89 cases with breast cancer were compared with 85 controls without the disease. Our study showed that breastfeeding had an odds ratio of 4.43 after adjustment for confounders. The results add to the evidence of a protective association between breast feeding practices and breast cancer particularly among Chinese women receiving treatment at two government hospitals in the Klang Valley.
MeSH terms: Adult; Breast Feeding*; Breast Neoplasms/ethnology; Breast Neoplasms/etiology*; Breast Neoplasms/epidemiology*; China/ethnology; Cross-Sectional Studies; Female; Humans; Life Style*; Malaysia/epidemiology; Middle Aged; Risk Factors; Rural Population; Chi-Square Distribution; Logistic Models; Case-Control Studies