New discoveries and directions for medical, dental and dental hygiene research: low temperature atmospheric pressure plasma

Abstract:  The study of plasma integrates physics, chemistry, biology, and engineering, and has recently engaged medicine and dental hygiene in research efforts. The study of plasma holds promise for a myriad of applications ranging from lasers and electronics, hazardous waste management, decontamination, sterilization and disinfection of foods, soil, water, instruments, to medical uses in wound healing and treating certain types of tumours and cancers. Plasma represents a new state-of-the-art sterilization and disinfection treatment for certain oral and enviornmental pathogens, heat-sensitive materials, contaminated medical waste, hard and soft surfaces, and ventilation systems may assist health care facilities in the management of various health concerns. The role that Low Temperature Atmospheric Pressure Plasma (LTAPP) could play in the inactivation of pathogenic microorganisms might prove to be a new, faster, noncorrosive, more economical alternative, as well as support green healthcare.     

Technique for axillary radiotherapy using computer‐assisted planning for high‐risk skin cancer†

High‐risk skin cancer arising on the upper limb or trunk can cause axillary nodal metastases. Previous studies have shown that axillary radiotherapy improves regional control. There is little published work on technique. Technique standardization is important in quality assurance and comparison of results especially for trials. Our technique, planned with CT assistance, is presented. To assess efficacy, an audit of patients treated in our institution over a 15‐month period was conducted. Of 24 patients treated, 13 were treated with radical intent, 11 with this technique. With a follow up of over 2 years, the technique had more than a 90% (10/11) regional control in this radical group. Both of the radical patients who were not treated according to the technique had regional failure. One case of late toxicity was found, of asymptomatic lymphoedema in a radically treated patient. This technique for axillary radiotherapy for regional control of skin cancer is acceptable in terms of disease control and toxicity as validated by audit at 2 years.     

Progression of Epididymal Maldevelopment Into Hamartoma-like Neoplasia in VHL Disease

Inactivation of the von Hippel-Lindau (VHL) gene and activation of the hypoxia-inducible factor (HIF) in susceptible cells precedes formation of tumorlets and frank tumor in the epididymis of male VHL patients. We performed detailed histologic and molecular pathologic analysis of tumor-free epididymal tissues from VHL patients to obtain further insight into early epididymal tumorigenesis. Four epididymides from two VHL patients were serially sectioned to allow for three-dimensional visualization of morphologic changes. Areas of interest were genetically analyzed by tissue microdissection, immunohistochemistry for HIF and markers for mesonephric differentiation, and in situ hybridization for HIF downstream target vascular endothelial growth factor. Structural analysis of the epididymides revealed marked deviations from the regular anatomic structure resulting from impaired organogenesis. Selected efferent ductules were represented by disorganized mesonephric cells, and the maldeveloped mesonephric material was VHL-deficient by allelic deletion analysis. Furthermore, we observed maldeveloped mesonephric material near cystic structures, which were also VHL-deficient and were apparent derivatives of maldeveloped material. Finally, a subset of VHL-deficient cells was structurally integrated in regular efferent ductules; proliferation of intraductular VHL-deficient cells manifests itself as papillary growth into the ductular lumen. Furthermore, we clarify that that there is a pathogenetic continuum between microscopic tumorlets and formation of tumor. In multiple locations, three-dimensional reconstruction revealed papillary growth to extend deeply into ductular lumina, indicative of progression into early hamartoma-like neoplasia. We conclude epididymal tumorigenesis in VHL disease to occur in two distinct sequential steps: maldevelopment of VHL-deficient mesonephric cells, followed by neoplastic papillary proliferation.     

Effect of decreased mobility on body composition in patients with Alzheimer's disease

Randomly selected 50 patients with the diagnosis of probable Alzheimer's disease, hospitalized for long-term care in a Special Care Dementia unit, were examined. None of the patients were clinically malnourished although several had low cholesterol levels. The mean lean body mass, measured by bioelectrical impedance plethysmography, was 62.5% of total body mass. The average calorie intake was 2125+398 Kcal/day, ranging from 1300 to 2900 Kcal/day, and the body weight of most subjects was stable, with the average gain of 1 lbs in the previous three months. Eighteen patients ambulated independently, 14 required assistance, and 18 were non-ambulatory. The lean body mass index was associated with the patient's age and mobility status. These results indicate that patients with advanced dementia and compromised mobility have decreased muscle mass that may result in weight loss even in the absence of malnutrition.     

Risk factors for development of dehydration in young children with acute watery diarrhoea: a case-control study

In a case-control study to understand the risk factors for development of life-threatening dehydration, a total of 379 children comprising 243 cases (moderate or severe dehydration) and 136 controls (non or mild dehydration) up to 2 years of age suffering from acute watery diarrhoea were studied. By univariate analysis, the presence of vibrios in stool, withdrawal of breast feeding during diarrhoea, not giving fluids, including oral rehydration solution (ORS), during diarrhoea, frequent purging (> 8/ day), vomiting (> 2/day) and undernutrition were identified as risk factors. However, by multivariate analysis after controlling for confounders, withdrawal of breast feeding during diarrhoea (odds ratio (OR) = 6.8, p < 0.00001) and not giving ORS during diarrhoea (OR = 2.1, p < 0.006) were identified as significant risk factors. The confounding variables which also contributed significantly to increasing the risk were age (≤ 12 months; OR = 2.7, p = 0.001), frequent purging (> 8/day; OR = 4.1, p < 0.00001), vomiting (> 2/day; OR = 2.4, p = 0.001) and severe undernutrition (%median <60 weight-for-age of Indian Academy of Paediatrics classification; OR = 3.1, p = 0.001). We feel that these findings will be useful for Global and National Diarrhoeal Diseases Control Programmes for formulating intervention strategies for preventing death due to diarrhoeal dehydration.     

Regional brain atrophy in patients with mild Alzheimer's disease and delusions

BACKGROUND AND OBJECTIVE: The pathophysiology and the neurobiology of the behavioral disturbances in Alzheimer's disease (AD) are far from understood. The aim of the study was to assess whether delusional AD patients have a specific pattern of regional brain atrophy. METHODS: The setting of the study was the outpatient facility of a memory clinic. Subjects were 41 AD patients with mild dementia severity (Mini-Mental State Exam score of 22 +/- 3, range 18 to 27). Delusions were assessed with the pertinent subscale of the UCLA Neuropsychiatric Inventory (NPI). Nondelusional (n = 22) AD and delusional (n = 19) AD were defined on the basis of absence (NPI delusions subscale = 0) or presence (NPI delusions subscale = 1 or higher) of delusions. Thirteen (68%) of the delusional patients had isolated theft delusions, and 6 (32%) had theft associated with another paranoid delusion (of jealousy or persecution). None of the patients had misidentifications or other delusions of nonparanoid content. Temporal lobe and frontal lobe atrophy were assessed with linear measures (radial width of the temporal horn, rWTH, and frontal index, FI) taken from computed tomographic films. Temporal and frontal asymmetries were computed as right/left ratio of the rWTH and FI. RESULTS: AD patients without delusions had symmetrical enlargement of both temporal (8.1 +/- 3.9 vs. 8.5 +/- 4.5) and frontal horns (35.8 +/- 4.8 vs. 35.9 +/- 4.6). On the contrary, AD with delusions showed temporal horns larger to the right (9.1 +/- 3.3 vs. 7.7 +/- 3.1, p = .06) and the frontal horn to the left (35.7 +/- 4.3 vs. 37.5 +/- 4.2, p = .02). This different pattern was confirmed with a gender-adjusted repeated measures analysis of variance model interaction term between asymmetry and group: F1,38 = 5.5, p = .03). DISCUSSION: AD patients with delusions are characterized by a specific pattern of frontal and temporal asymmetry of brain atrophy, whereas nondelusional patients are symmetric. Because the asymmetry pattern of the delusional patients is similar to the physiological pattern of asymmetry of individuals without dementia, the data indicate that the absence of theft delusions in the mild stage of AD rather than their presence is associated with an abnormal asymmetry pattern.     

Clinical characteristics of frontotemporal patients with symmetric brain atrophy

In this paper we explored patterns of frontal and temporal asymmetry in frontotemporal dementia (FTD) and tried to isolate clinical correlates associated with asymmetry or lack thereof. Volumes of frontal and temporal lobes, hippocampus and entorhinal cortex were measured using magnetic resonance imaging (MRI) in 10 patients with FTD. Age- and cranial size-specific values were computed through linear regression analysis (W-scores). A subgroup of 3 patients with symmetric frontal and temporal atrophy was identified. When compared to patients with asymmetric atrophy, the former had younger age at onset of the disease (p = 0.02), greater overall frontotemporal (p = 0.02) and greater entorhinal atrophy (p < 0.04). Two of the three patients were apolipoprotein E ɛ4 carriers versus none of the asymmetric patients (p = 0.02). The lack of asymmetry in this small sample of FTD patients was associated with greater brain atrophy, younger age at onset, and presence of the ɛ4 allele of apolipoprotein E. The presence of the ɛ4 allele is consistent with the hypothesis of greater vulnerability of the brain in ɛ4 carriers. Received: 15 April 2002 / Accepted: 2 October 2002 Correspondence to Dr. G. B. Frisoni