Objective: The smoking rate among patients with mental health problem is higher than in the general population. Effective pharmacotherapy to treat nicotine addiction is thus needed to reduce the morbidity and mortality associated with cigarette smoking among these patients. This article reviews the literature on the suitability of varenicline for smokers with mental health problems.
Methods: A search of the literature was conducted using PubMed from year 2001 to July 2009 using key words varenicline alone and varenicline and mental health. Articles chosen were narrowed to those published in English. The type of articles chosen included clinical trials, metaanalyses, case reports, and review articles.
Results: The search produced a total of 322 articles on varenicline and 14 articles on varenicline and mental health. Varenicline, a new drug for smoking cessation is an α4β2 partial agonist and partial antagonist at nicotinic acetylcholine receptor. As a partial agonist, varenicline relieves craving and withdrawal symptoms that occur during smoking abstinence and also reduce the rewarding effects of smoking in patients who relapse. However, at present, there is concern regarding the neuropsychiatric side effects such as aggressive behaviour, suicidal ideation, mania and depression associated with varenicline use in patients with mental health problems, but these reports did not show a causal-link or lack of link between these symptoms and varenicline.
Conclusion: Current available data support the effectiveness of varenicline to treat nicotine dependence. However its safety among smokers with mental health problems remains to be elucidated. At present, further safety assessment is needed in this patient population. Until new data is available regarding the safety of varenicline in these populations, psychiatrists and physicians prescribing this medication should be extra cautious and monitor for possible psychiatric side effects when prescribing this medication to patients with pre-existing psychiatric disorders or have vulnerability to psychoses.
The operating principle and the performance of chromatic dispersion (CD) measurement technique are discussed through developed numerical models. The performance of the CD measurement technique was studied in terms of the measurement range and sensitivity as the wavelength separation was varied. Based on the numerical model, the technique sensitivity increased with wavelength separation. However, this increase in sensitivity was traded off with a narrower measurement range. The measurement technique was optimized at 5.0 GHz wavelength separation with a sensitivity of 0.009 (dB/ps/nm) and measurement range of 2500 ps/nm.
This paper proposes a signal-to-noise-ratio (SNR) improvement by using an external phase modulator that allowed flexible control of the spectrum amplitude by varying the modulation index for linewidth measurements. Compared with the conventional self-heterodyne detection technique, the results obtained in this study showed an SNR improvement as high as 10 dB. This 10 dB improvement in SNR could help to reduce the usage of a particular length of a single mode fibre (normally about 50 Km) when measuring a linewidth in the region of 10 kHz.
BACKGROUND: Data comparing the effect of losartan and perindopril on aortic stiffness among hypertensive subjects without A(1166)C polymorphism was not available.
METHODS: The short-term and long-term effects of losartan (50 mg) and perindopril (4 mg) on aortic stiffness measured as carotid femoral pulse wave velocity (PWV) were compared in 39 middle-aged Malay subjects with mild-to-moderate hypertension in a 4-month, double-blind, randomized, controlled, parallel-design study.
RESULTS: Four-month treatment with both drugs showed a significant reduction in blood pressure (BP) (P < .005) and PWV (P < .05) as compared to the baseline. On the other hand 1-month treatment showed a significant reduction in BP only in perindopril group (P < .05) but not in the losartan group. There was no significant reduction in pulse pressure and PWV after 1 month treatment by both drugs. No significant difference was seen in reduction in BP after 1 month and 4 months treatment between the two drugs. Similarly no significant difference was seen in reduction in PWV between the two drugs after 1 month (P = .613) and 4 months (P = .521) of treatment. Reduction in PWV by losartan (r = 0.470) and perindopril (r = 0.457) correlated significantly only with reduction in DBP (P < .05) and remained significant even after controlling for reduction in DBP (P < .05). Reduction in PWV by both losartan and perindopril was independent of reduction in BP by these drugs.
CONCLUSIONS: These results showed that long-term treatment with losartan shows similar pressure independent reduction in PWV as perindopril among Malay hypertensive subjects with a homogenous "AA" genotype for angiotensin II type 1 receptor and may serve as a suitable alternative to perindopril.
We experimentally demonstrate a simple method for generating a multiwavelength Brillouin comb by utilizing a linear cavity of hybrid Brillouin-erbium fiber lasers (BEFLs). The optimization of Brillouin pump wavelength, power, and erbium gain played a significant role in determining the maximum number of Brillouin Stokes signals generated. Simultaneous and stable multiple-wavelength laser output of 22 lines with 10.88-GHz channel spacing has been obtained with good flatness. Various parameters such as 980-nm pump power, Brillouin pump wavelength, and Brillouin pump power that affect the performance of a multiwavelength BEFL system have been investigated. An analysis of the tuning range of the system is presented.
This study examined the effect of mouth rinsing during endurance cycling in a hot humid environment (32 °C and 75% relative humidity) on athletes in the Ramadan fasted state. Nine trained adolescent male cyclists completed 3 trials that consisted of a carbohydrate mouth-rinse (CMR), a placebo mouth-rinse (PMR), and a no-rinse (NOR) trial during the last 2 weeks of Ramadan. Each trial consisted of a preloading cycle at 65% peak rate of oxygen consumption for 30 min followed by a 10-km time trial (TT10 km) under hot humid condition. During the CMR and PMR trials, each cyclist rinsed his mouth with 25 mL of the solution for 5 s before expectorating the solution pre-exercise, after 5, 15, and 25 min of the preloading cycle, and 15 s prior to the start of TT10 km. Time to complete the TT10 km was significantly faster in the CMR and PMR trials compared with the NOR trial (12.9 ± 1.7 and 12.6 ± 1.7 vs. 16.8 ± 1.6 min, respectively; p < 0.017). Ratings of perceived exertion taken at the end of the TT10 km was lower in both CMR and PMR trials compared with the NOR trial, although the difference was significant only between CMR and NOR (p < 0.05). In conclusion, mouth rinsing with either carbohydrate or placebo solution provided ergogenic benefits compared with a no-rinse condition on TT10 km performance in acute Ramadan fasted subjects during endurance cycling in a heat stress environment.
Important thermoluminescence (TL) properties of five (5) different core sizes Ge-doped optical fibers have been studied to develop new TL material with better response. These are drawn from same preform applying different speed and tension during drawing phase to produce Ge-doped optical fibers with five (5) different core sizes. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge-doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (SEM) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in Secondary Standard Dosimetry Lab (SSDL) was used for irradiation covering dose range from 1Gy to 10Gy. The essential dosimetric parameters that have been studied are TL linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5cm length are annealed at temperature of 400°C for 1h period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1h at 400°C and subsequently 2h at 100°C to yield the highest sensitivity. TL responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Zeff) is found in the range (13.25-13.69) which is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. TL properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry.
The thermoluminescence (TL) glow curves and kinetics parameters of Thulium (Tm) doped silica cylindrical fibers (CF) are presented. A linear accelerator (LINAC) was used to deliver high-energy radiation of 21MeV electrons and 10MV photons. The CFs were irradiated in the dose range of 0.2-10Gy. The experimental glow curve data was reconstructed by using WinREMS. The WinGCF software was used for the kinetic parameters evaluation. The TL sensitivity of Tm-doped silica CF is about 2 times higher as compared to pure silica CF. Tm-doped silica CF seems to be more sensitive to 21MeV electrons than to 10MV photons. Surprisingly, no supralinearity was displayed and a sub-linear response of Tm-doped silica CF was observed within the analyzed dose range for both 21MeV electrons and 10MV photons. The Tm-doped silica CF glow curve consists of 5 individual glow peaks. The Ea of peak 4 and peak 5 was highly dependent on dose when irradiated with photons. We also noticed that the electron radiation (21MeV) caused a shift of glow peak by 7-13°C to the higher temperature region compared with photons radiation (10MV). Our Tm-doped fibers seem to give high TL response after 21MeV electrons, which gives around 2 times higher peak integral as compared with 10MV photon radiation. We concluded that peak 4 is the first-order kinetic peak and can be used as the main dosimetric peak of Tm-doped silica CF.
Using irradiated doped-silica preforms from which fibres for thermoluminescence dosimetry applications can be fabricated we have carried out a range of luminescence studies, the TL yield of the fibre systems offering many advantages over conventional passive dosimetry types. In this paper we investigate such media, showing emission spectra for irradiated preforms and the TL response of glass beads following irradiation to an 241Am-Be neutron source located in a tank of water, the glass fibres and beads offering the advantage of being able to be placed directly into liquid. The outcomes from these and other lines of research are intended to inform development of doped silica radiation dosimeters of versatile utility, extending from environmental evaluations through to clinical and industrial applications.
In regard to thermoluminescence (TL) applied to dosimetry, in recent times a number of researchers have explored the role of optical fibers for radiation detection and measurement. Many of the studies have focused on the specific dopant concentration, the type of dopant and the fiber core diameter, all key dependencies in producing significant increase in the sensitivity of such fibers. At doses of less than 1 Gy none of these investigations have addressed the relationship between dose response and TL glow peak behavior of erbium (Er)-doped silica cylindrical fibers (CF). For x-rays obtained at accelerating potentials from 70 to 130 kVp, delivering doses of between 0.1 and 0.7 Gy, present study explores the issue of dose response, special attention being paid to determination of the kinetic parameters and dosimetric peak properties of Er-doped CF. The effect of dose response on the kinetic parameters of the glow peak has been compared against other fiber types, revealing previously misunderstood connections between kinetic parameters and radiation dose. Within the investigated dose range there was an absence of supralinearity of response of the Er-doped silica CF, instead sub-linear response being observed. Detailed examination of glow peak response and kinetic parameters has thus been shown to shed new light of the rarely acknowledged issue of the limitation of TL kinetic model and sub-linear dose response of Er-doped silica CF.
In previous work we investigated the real-time radioluminescence (RL) yield of Ge-doped silica fibres and Al2O3 nanodot media, sensing electron- and x-ray energies and intensities at values familiarly obtained in external beam radiotherapy. The observation of an appreciable low-dose sensitivity has given rise to the realisation that there is strong potential for use of RL dosimetry in diagnostic radiology. Herein use has been made of P-doped silica optical fibre, 2 mm diameter, also including a 271 µm cylindrical doped core. With developing needs for versatile x-ray imaging dosimetry, preliminary investigations have been made covering the range of diagnostic x-ray tube potentials 30 kVp to 120 kVp, demonstrating linearity of RL with kVp as well as in terms of the current-time (mAs) product. RL yields also accord with the inverse-square law. Given typical radiographic-examination exposure durations from tens- to a few hundred milliseconds, particular value is found in the ability to record the influence of x-ray generator performance on the growth and decay of beam intensity, from initiation to termination.
Present study concerns the key thermoluminescence (TL) properties of photonic crystal fibres (PCFs), seeking development of alternatively structured TL materials that are able to offer a advantages over existing passive dosimeters. In terms of their internal structure and light guiding properties the PCFs, collapsed and structured, differ significantly from that of conventional optical fibres. To investigate the dosimetric parameters of the PCFs use was made of a linear accelerator producing a 6 MV photon beam, delivering doses ranging from 0.5 Gy to 8 Gy. The parameters studied included TL response, linearity index, glow curves, relative sensitivity and TL signal fading, the results being compared against those obtained using TLD-100 chips. At 4 Gy photon dose the Ge-doped collapsed PCFs were found to provide a response 27 × that of structured PCF, also giving a TL yield similar to that of standard TLD-100 chips. Over post-irradiation periods of 15 and 30 days collapsed PCF TL signal fading were 8% and 17% respectively, with corresponding values of 37% and 64% for the structured PCF. Trapping parameters including the order of kinetics (b), activation energy (E) and frequency factor (s-1) were assessed with Chen's peak shape method. Lifetime of trapping centre was found to be (2.36 E+03) s and (9.03 E +01) s regarding the collapsed and structured PCF respectively with 6 Gy of photon beam. For the Ge-doped collapsed PCF, the high TL yield, sensitivity and low fading provide the basis of a highly promising system of TLD for radiotherapy applications.
Investigation has been made of the radioluminescence dose response of Ge-doped silica flat and cylindrical fibers subjected to 6 and 10 MV photon beams. The fibers have been custom fabricated, obtaining Ge dopant concentrations of 6 and 10 mol%, subsequently cut into 20 mm lengths. Each sample has been exposed under a set of similar conditions, with use made of a fixed field size and source to surface distance (SSD). Investigation of dosimetric performance has involved radioluminescence linearity, dose-rate dependence, energy dependence, and reproducibility. Mass for mass, the 6 mol% Ge-doped samples provided the greater radioluminescence yield, with both flat and cylindrical fibers responding linearly to the absorbed dose. Further found has been that the cylindrical fibers provided a yield some 38% greater than that of the flat fibers. At 6 MV, the cylindrical fibers were also found to exhibit repeatability variation of <1%, superior to that of the flat fibers, offering strong potential for use in real-time dosimetry applications.
Review is provided of a number of low-dose, low dose rate situations that in study require advances in the development of dosimetric facilities. Using a clinical linac set up to provide doses down to the few mGy level, the performance of a real-time radioluminescence system has then been illustrated, accommodating pulsed as well as continuous dose delivery. The system gate times provide for tracking of the pattern of dose delivery, allowing detailed account of dose and dose-rate variations. The system has been tested in both x-ray and electron mode dose delivery.
Many minerals and compounds show thermoluminescence (TL) properties but only a few of them can meet the requirements of an ideal dosimeter. Several phosphate materials have been studied for low-dose dosimetryin recent times. Among the various phosphates, ABPO4-type material shows interesting TL properties. In this study, an ABPO4-type (A = Lithium, B=Calcium) phosphor is synthesized using a modified solid-state diffusion method. Temperature is maintained below 800 °C in every step of phosphor preparation to obtain the pure phase of Lithium calcium phosphate (LiCaPO4). The purpose of this work is to synthesize LiCaPO4 using a simple method, examine its structural and luminescence properties in order to gain a deeper understanding of its TL characteristics. The general TL properties, such as TL glow curve, dose linearity, sensitivity, and fading, are investigated. Additionally, this study aims to determine various kinetic parameters through Glow Curve Deconvolution (GCD) method using the Origin Lab software together with the Chen model. XRD analysis confirmed the phase purity of the phosphor with a rhombohedral structure. Lattice parameters, unit cell volume, grain size, dislocated density, and microstrain were also calculated from XRD data. Raman analysis and Fourier Transform Infrared analysis were used to collect information about molecular bonds, vibrations, identity, and structure of the phosphor. To investigate TL properties and associated kinetic parameters, the phosphor was irradiated with 6.0 MV (photon energy) and 6.0 MeV (electron energy) from a linear accelerator for doses ranging from 0.5 Gy to 6.0 Gy. For both photon and electron energy, TL glow curves have two identical peaks near 200 °C and 240 °C.The TL glow curves for 0.5 Gy-6 Gy are deconvoluted, then fitted with the appropriate model and then calculated the kinetic parameters. Kinetic parameters such as geometric factor (μg), order of kinetics, activation energy (E), and frequency factor (s) are obtained from Chen's peak shape method. The dose against the TL intensity curve shows that the response is almost linear in the investigated dose range. For photon and electron energy, the phosphor is found to be the most sensitive at 2.0 Gy and 4.0 Gy, respectively. The phosphor shows a low fading and after 28 days of exposure, it shows a signal loss of better than 3%. The studied TL properties suggest the suitability of LiCaPO4 in radiation dosimetry and associated fields.
This is a cross-sectional study in a representative sample of preschool children from 12 preschools (TADIKA KEMAS) Pasir Mas, Kelantan, Malaysia. Data on socioeconomic status and sources of water supply at home were collected through interview with mothers. Children’s anthropometric data (height and weight) and body-mass-index-for-age (BMI-for-age) was calculated. Oral examinations of ECC status was based on the dmft index (WHO, 1997). The results showed mean
carious teeth were very high (dmft 11.1±4.8) and almost every preschool child was affected with ECC (prevalence 98.1%). The majority were in “high caries” category (i.e. dmft >7) and about 51.4% of preschoolers was underweight and only a few was overweight/obese. Preschool children with high caries mostly were underweight and normal of BMI. The BMI-for-age, household income and household expenditure for food were significant correlation with ECC experience (p
Dental caries is an important community dental health problem with limited studies in the mixed dentition stage. The aim of this study was to determine the caries prevalence and treatment needs among 7- 9 year old school children in Kelantan which is situated in North East Malaysia. A retrospective dental record review of fully documented dental records belonging to primary school children attending a paediatric dental clinic was conducted. Dental caries was recorded using dmft index and DMFT index for deciduous teeth and permanent teeth respectively. Three hundred and nineteen dental records of 175 (54.9%) boys’ and 144 (45.1%) girls’ were selected and subjected to a ‘dental record study’. The prevalence of dental caries was 93% (95% CI : 89,97) in primary dentition and 50.5% (95% CI : 42.2, 58.8) in permanent teeth. Mean dmft and DMFT was 6.2(SD 3.39) and 1.04(SD 1.34) respectively. Regarding treatment needs in the primary dentition, 35.4% of teeth needed one surface filling, 34.7% needed extraction, 24.5% needed two or more surfaces filling and 5.6% needed pulp care. In the permanent dentition, 54.7% required sealants and 21.9% required one surface restoration. The caries prevalence and treatment needs were high among this study population in the mixed dentition stage, particularly showing the early involvement of newly erupted permanent teeth. It appears that high caries prevalence in the primary dentition is a risk factor for caries in newly erupted permanent teeth. Oral health promotions programmes are required in the mixed dentition stage and may reduce the risk of caries in permanent dentition.
The aim of this study was to determine the genotoxicity of a locally produced nanocomposite by Universiti Sains Malaysia, Malaysia using Comet assay. Stem cells from human exfoliated deciduous teeth (SHED) were treated with the nanocomposite at five different concentrations (0.006, 0.0125, 0.025, 0.05, and 0.1 mg/ml) along with concurrent negative (medium alone) and positive control (zinc sulfate heptahydrate) and incubated at 37°C for 24 hours in an incubator at 5% CO2. The tail moment was used to assess the extent of DNA damage. The tail moment for the group of SHED treated with nanocomposite (for all the five different concentrations) was not statistically significant as compared to the negative control, suggesting that the locally produced dental nanocomposite did not induce any DNA damage. Hence, it can be concluded that the locally produced nanocomposite is non-genotoxic on stem cells from human exfoliated deciduous teeth.
BACKGROUND: Hypertension is one of the world's most common health conditions and is a leading risk factor for mortality. Although blood pressure can be modified, there is a large proportion of patients whose blood pressure remains uncontrolled. The aim of this study, termed Edvantage 360°, was to gain a deeper understanding of hypertension management in Asia from the perspective of patients and doctors, and to propose strategies to improve blood pressure control.
METHODS: Conducted in Hong Kong, Indonesia, Malaysia, the Philippines, South Korea, Taiwan, and Thailand, Edvantage 360° was a mixed-methods observational study that used both qualitative and quantitative elements: qualitative interviews and focus groups with patients (N = 110), quantitative interviews with patients (N = 709), and qualitative interviews with doctors (N = 85).
RESULTS: This study found that, although there is good understanding of the causes and consequences of hypertension among Asian patients, there is a lack of urgency to control blood pressure. Doctors and patients have different expectations of each other and a divergent view on what constitutes successful hypertension management. We also identified a fundamental gap between the beliefs of doctors and patients as to who should be most responsible for the patients' hypertension management. In addition, because patients find it difficult to comply with lifestyle modifications (often because of a decreased understanding of the changes required), adherence to medication regimens may be less of a limiting factor than doctors believe.
CONCLUSIONS: Doctors may provide better care by aligning with their patients on a common understanding of successful hypertension management. Doctors may also find it helpful to provide a more personalized explanation of any needed lifestyle modifications. The willingness of the doctor to adjust their patient interaction style to form a 'doctor-patient team' is important. In addition, we recommend that doctors should not attribute ineffectiveness of the treatment plan to patient non-adherence to medications, but rather adjust the medication regimen as needed.
KEYWORDS: Attitude to health; Hong Kong; Hypertension; Indonesia; Malaysia; Philippines; Qualitative research; South Korea; Taiwan; Thailand