Managing complications of radiation therapy in head and neck cancer patients: Part V. Management of mucositis

Head and neck cancer is becoming a more recognizable pathology to the general population and dentists. The modes of treatment include surgery and/or radiation therapy. Where possible, pretreatment dental assessment shall be provided for these patients before they undergo radiation therapy. There are occasions, however, whereby head and neck cancer patients are not prepared optimally for radiation therapy. Because of this, they succumb to complicated oral adverse effects after radiation therapy. The second last part of this series reviews and discusses the management of complication that commonly occur to the oral mucosa, i.e. mucositis.     

Wavelet-based compression of medical images: filter-bank selection and evaluation

Wavelet-based image coding algorithms (lossy and lossless) use a fixed perfect reconstruction filter-bank built into the algorithm for coding and decoding of images. However, no systematic study has been performed to evaluate the coding performance of wavelet filters on medical images. We evaluated the best types of filters suitable for medical images in providing low bit rate and low computational complexity. In this study a variety of wavelet filters are used to compress and decompress computed tomography (CT) brain and abdomen images. We applied two-dimensional wavelet decomposition, quantization and reconstruction using several families of filter banks to a set of CT images. Discreet Wavelet Transform (DWT), which provides efficient framework of multi-resolution frequency was used. Compression was accomplished by applying threshold values to the wavelet coefficients. The statistical indices such as mean square error (MSE), maximum absolute error (MAE) and peak signal-to-noise ratio (PSNR) were used to quantify the effect of wavelet compression of selected images. The code was written using the wavelet and image processing toolbox of the MATLAB (version 6.1). This results show that no specific wavelet filter performs uniformly better than others except for the case of Daubechies and bi-orthogonal filters which are the best among all. MAE values achieved by these filters were 5 x 10(-14) to 12 x 10(-14) for both CT brain and abdomen images at different decomposition levels. This indicated that using these filters a very small error (approximately 7 x 10(-14)) can be achieved between original and the filtered image. The PSNR values obtained were higher for the brain than the abdomen images. For both the lossy and lossless compression, the 'most appropriate' wavelet filter should be chosen adaptively depending on the statistical properties of the image being coded to achieve higher compression ratio.     

Population ecology and movement of the American cockroach (Dictyoptera: Blattidae) in sewers

The population size, age-class structure, and movement of the American cockroach, Periplaneta americana (L.) (Dictyoptera: Blattidae), were studied in three sewers in Penang, Malaysia, from September 2008 to October 2009. Eighteen to 20 glass-jar traps (two per manhole) were deployed for a 24-h period during each sampling occasion at each sewer. Adults and nymphs were active throughout the study period, with an average monthly trap catch of 57-97 adults and 79-99 nymphs. The mean proportions of adults and nymphs at the three sewers ranged from 0.47 to 0.57. Of the 2177 male and 2717 female cockroaches marked and released over the three sewers, recapture rates were 29.4-45.8 and 30.8-47.0%, respectively. The proportion of marked males and females did not differ significantly from the proportion of recaptured marked males and females. However, the mean number of times a marked female was recaptured was significantly greater than that of males. Of the 783 males and 1,030 females that were marked and recaptured, 19.4 and 24.7%, respectively, had moved between manholes, and significantly more females than males moved between manholes. Of the 406 recaptured marked adults that moved between manholes, 90.4% moved a distance of 2-20 m from their initial release site; one male moved 192 m, the longest distance recorded. Trap catch on each sampling occasion was positively correlated with daily mean temperature. The number of cockroach movements between manholes also was correlated with the mean daily minimum temperature.     

Gorham’s disease of the mandible: radiological features

The most conspicuous element of Gorham’s disease is its radiographic features, wherein massive disappearance of the mandible is observed. We report a case of an adolescent boy with massive osteolysis of the mandible in whom the diagnosis of Gorham’s disease was made. A 14-year-old boy was referred to the Department of Oral and Maxillofacial Surgery, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, for the management of a massive mandibular deformity. He was diagnosed with a hemangioma-like lesion at 1 year of age. The disease had progressed for an unknown number of years. Plain X-rays and computed tomography images were examined for reconstructive surgery planning. Gorham’s disease is self-limiting, but has catastrophic results. The role of imaging is huge, particularly for reconstructive surgery planning.     

The neuroprotective effects of(S)-3,5-dihydroxyphenylglycine preconditioning in middle cerebral artery occluded rats: a perspective as a contrivance for stroke

<正>Stroke is one of the fearsome causes of death that leads to high mortality and morbidity worldwide.Apparently,the management of choice for ischemic stroke is either by thrombolysis or thrombectomy.The paramount challenge in most clinical cases is that those interventions are time-dependent as they need     

A retrospective study of oral and maxillofacial injuries in Seremban Hospital,Malaysia

Abstract – Introduction: Aetiology of oral and maxillofacial injuries in this country includes motorvehicle accident (MVA), fall, industrial accidents and others. Among these causes, MVA accident is the predominant cause of injury in Malaysia. Materials and methods: A retrospective record review was carried out using hospital records of all patients who sustained oral and maxillofacial injury at the Department of Oral Surgery, Seremban Hospital, Negeri Sembilan, Malaysia between 1998 and 2002. Information related to demographics, aetiology of trauma, vehicles involved in collision, location of injuries and treatment modalities were reviewed. Results: Two thousand nine hundred and eighty‐six patients sustained oral and maxillofacial injuries. Of these patients, 79.2% were men and the remaining were women. Among all the races, Malays had the highest involvement (50.6%) followed by Indians (24.5%), Chinese (19.6%) and others (5.3%). There were statistically significant results on the association of aetiology and the ethnic groups, in the age group of 30 years or less and male gender (P < 0.001). The most common injury was the soft‐tissue injury followed by dental and dentoalveolar injuries and bony fracture. Among all facial fractures, 66.3% were managed conservatively, 13% were treated surgically and 19.7% did not have any intervention. In relation to dental and dentoalveolar injuries, 64.8% had treatment in the form of splinting, restorations or dental extraction. The rest of the patients (35.2%) were referred to their dentists or did not have any active treatment at Seremban Hospital. Conclusion: Most of the dental and facial injuries in Seremban Hospital were caused by MVA and were predominantly managed using conservative methods.     

Indirect effects of cigarette butt waste on the dengue vector Aedes aegypti (Diptera: Culicidae)

Despite major insecticide-based vector control programs, dengue continues to be a major threat to public health in urban areas. The reasons for this failure include the emergence of insecticide resistance and the narrowing of the spectrum of efficient products. Cigarette butts (CBs), the most commonly discarded piece of waste, also represent a major health hazard to human and animal life. CBs are impregnated with thousands of chemical compounds, many of which are highly toxic and none of which has history of resistance in mosquitoes. This study was performed to examine whether exposure to CB alters various biological parameters of parents and their progeny. We examined whether the mosquito changes its ovipositional behaviors, egg hatching, reproductive capacity, longevity and fecundity in response to CB exposure at three different concentrations. Females tended to prefer microcosms containing CBs for egg deposition than those with water only. There were equivalent rates of eclosion success among larvae from eggs that matured in CB and water environments. We also observed decreased life span among adults that survived CB exposure. Extracts of CB waste have detrimental effects on the fecundity and longevity of its offspring, while being attractive to its gravid females. These results altogether indicate that CB waste indirectly affect key adult life traits of Aedes aegypti and could conceivably be developed as a novel dengue vector control strategy, referring to previously documented direct toxicity on the larval stage. But this will require further research on CB waste effects on non-target organisms including humans.     

Turning cigarette butt waste into an alternative control tool against an insecticide-resistant mosquito vector

Annually, 4.5 trillion cigarette butts (CBs) are flicked into our environment. Evidence exists that CB waste is deadly to aquatic life, but their lethality to the aquatic life of the main dengue vector is unknown. CBs are full of toxicants that occur naturally, during planting and manufacturing, which may act as larvicidal agents. We assessed Aedes aegypti vulnerability to Marlboro butts during its development. Overall, CBs showed insecticidal activities against larvae. At early phases of development, mortality rates were much higher in two CBs solution (2CBSol) and 3CBSol microcosms (MICRs). Larval survival gradually decreased with development in 1CBSol-MICRs. However, in great presence of CBs, mortality was high even for the late developmental stages. These results suggest that A. aegypti larvae are vulnerable to CB presence in their habitats, but this effect was seen most during the early developmental phases and in the presence of increased amounts of cigarette remnants. CB filters are being used as raw material in many sectors, i.e., brick, art, fashion, plastic industries, as a practical solution to the pollution problem, the observed butt waste toxicity to mosquito larvae open new avenues for the identification of novel insecticide products.     

DASS21: A Useful Tool in the Psychological Profile Evaluation of Dialysis Patients

Background

The effect of dialysis treatment is complex, with both clinical and socio-psychological effects. In this study, we aimed to assess the psychological status of this growing population of end-stage renal disease.