Population-based dietary intakes and tap water concentrations for selected elements in the EPA region V National Human Exposure Assessment Survey (NHEXAS).

A National Human Exposure Assessment Survey (NHEXAS) field study was performed in U.S. Environmental Protection Agency (EPA) Region V, providing population-based exposure distribution data for selected elements in several personal, environmental, and biological media. Population distributions are reported for the 11 elements that were measured in water and dietary samples. Dietary intakes and home tap water concentrations of lead, arsenic, and cadmium were further examined for intermedia associations, for differences between dietary exposure for adults and children, and to estimate the proportion of the population above health-based reference values (dietary) or regulatory action levels or maximum contaminant levels (water). Water lead and arsenic concentrations were significantly associated with dietary intake. Intake of all elements was higher from solid foods than from liquid foods (including drinking water). Dietary intakes of Pb, As, and Cd were greater than those calculated for intake from home tap water or inhalation on a microg/day basis. Median dietary intakes for the Region V population for Pb, As, and Cd were 0.10, 0.13, and 0.19 microg/kg bw/day, respectively. While Pb, As, and Cd concentrations in the foods consumed by 0 to 6-year-old children were similar to or lower than those for adults, dietary intakes calculated on a body weight basis were 1.5 to 2.5 times higher for young children. Intrapersonal intake differences accounted for most of the variance in short-term (daily) dietary intakes for Pb and As, while interpersonal differences accounted for more of the intake variance for Cd. Only small percentages of the population exceeded health-based intake reference values or concentrations equal to regulatory levels in water for Pb, As, and Cd.     

Effects of the solvents on bond strength of resin bonded porcelain

Clinical trials of porcelain veneers for chairside colour modifications may require the use of a trial resin with various colours of tints. The bond strength effects of four different solvents used for removal of trial resin from etched porcelain specimens were investigated. Fifty-six porcelain specimens were fabricated, flattened by a metallurgically standard method, etched with hydrofluoric acid and silane treated. The specimens were divided into four groups at random. The trial resin material was cleaned with different solvents prior to bonding of a dual cure resin composite button. After bonding the specimens were stored in water at 37 degrees C for 7 days. Shear bond strength results were as follows: acetone (control) group, 12.9+/-2.9 MPa; ethanol group, 15.1+/-4.6 MPa; methanol group, 11.5+/-2.9 MPa; methylene chloride group, 11.3+/-2.4 MPa. No significant differences were measured (ANOVA, P>0.05). The results indicated that the resin-porcelain bond strengths were not affected by the type of solvent used to remove trial resin. This procedure is recommended for clinical cases when resin composite is used for the try-in of etched porcelain bonded restorations.     

Lung cancer in patients aged 50 years and younger: clinical characteristics, treatment details and outcome

Younger patients (< or = 50 years of age) develop lung cancer. Many series report 5-10% of all cases occurring in younger patients. Outcome, inspite of treatment, is universally poor. Females and adenocarcinomas are over-represented and the aetiology for such an early-age presentation is unclear. The aims of this retrospective study were to review the clinical characteristics, treatment details and outcome of patients aged 50 years or younger diagnosed with lung cancer (small cell and non-small cell). Over a period of 34 months, 497 lung cancer patients were treated at the Liverpool Hospital Cancer Therapy Centre. Thirty-seven (7.4%) patients aged less than or equal to 50 years were identified. The median age at diagnosis was 44 years (range 32-49 years) in 20 females and 17 males. Adenocarcinoma was the predominant histological subtype (32%). No referred patient had stage I/II disease. Almost 90% of patients were smokers. Median survival following diagnosis was 12 months (range, 9 days-68 months) with 70% having died by the close of study. The clinical characteristics and outcome of young patients in our study were comparable to other similar series.     

Pelvic discontinuity in revision total hip arthroplasty

BACKGROUND: Pelvic discontinuity is a distinct form of bone loss, occurring in association with total hip arthroplasty, in which the superior aspect of the pelvis is separated from the inferior aspect because of bone loss or a fracture through the acetabulum. The purpose of this study was to describe the population of patients who are at risk for this condition, to identify the characteristic radiographic features associated with it, and to report the results of revision total hip arthroplasty for the treatment of pelvic discontinuity. METHODS: The cases of all twenty-seven patients (thirty-one hips) who were identified as having a pelvic discontinuity at the time of a reoperation for a failed hip arthroplasty at one institution were reviewed retrospectively, and demographic information was collected. The preoperative radiographs and the operative notes were reviewed, and the postoperative results and complications were recorded. RESULTS: Pelvic discontinuity was identified in association with thirty-one (0.9 percent) of 3505 acetabular revisions. The mean age of the patients was sixty-one years (range, thirty-eight to eighty years). Twenty-eight hips were in women, and three were in men. Women (p < 0.001) and patients who had rheumatoid arthritis (p = 0.003) had a significantly increased risk of pelvic discontinuity. The radiographic findings included a visible fracture line through the anterior and posterior columns, medial translation of the inferior aspect of the hemipelvis relative to the superior aspect (seen as a break in Kohler's line), and rotation of the inferior aspect of the hemipelvis relative to the superior aspect (seen as asymmetry of the obturator rings) on a true anteroposterior radiograph. Two patients died within two years after the revision, and two had a resection arthroplasty for the treatment of the pelvic discontinuity; thus, twenty-seven hips were reconstructed and were eligible for follow-up at least two years after the operation. A number of different methods were used for reconstruction, but the results were best in patients who did not have severe segmental acetabular bone loss (type IVa [a satisfactory result in three of three hips]) and poorer in those who had severe segmental or combined segmental and cavitary bone loss (type IVb [a satisfactory result in ten of nineteen hips]) and in those who previously had been treated with irradiation to the pelvis (type IVc [a satisfactory result in three of five hips]). Nine of the twenty-seven hips needed another operation: four, because of aseptic loosening of the acetabular component; four, because of recurrent dislocation; and one, because of deep infection. Excluding three hips that were revised early because of infection or dislocation, a mechanically stable construct (that is, a stable socket and a possibly or definitely healed discontinuity) was obtained in seventeen of twenty-four hips. CONCLUSIONS: Pelvic discontinuity is uncommon, and treatment is associated with a high rate of complications. For hips with type-IVa bone loss and selected hips with type-IVb defects, in which a socket inserted without cement can be satisfactorily supported by native bone, we prefer to use a posterior column plate to stabilize the pelvis and a porous-coated socket inserted without cement. For most hips with type-IVb and type-IVc bone loss, we prefer to use particulate bone graft or a single structural bone graft protected with an antiprotrusion cage.     

Effects of female sex steroids on Parkinson's disease in postmenopausal women

There are conflicting reports about estrogen modulating the activity of nigrostriatal dopaminergic neurons. Furthermore, modulation may be influenced by progesterone levels. Therefore, the clinical effects of sex steroids on parkinsonian symptoms in postmenopausal women with Parkinson's disease (PD) were analyzed in the present study. Patients (n = 12) were under the age of 80, able to perform the motor function tests, and showed no contraindications for estrogen suppletion. Motor function was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) and a patient interview on subjective changes. In a placebo-controlled, randomized, double-blind trial lasting 8 weeks, no significant dopaminergic effect of estradiol (E2) could be demonstrated, whereas in an open trial phase lasting 2 weeks, progesterone seemed to have an antidopaminergic effect. Several mechanisms are discussed that can account for the fact that we found no effect of E2 on motor functioning in our patients with PD.     

3-Nitropropionic acid induces a spectrum of Huntington's disease-like neuropathology in rat striatum

Systemic administration of the mitochondrial toxin 3-nitropropionic acid (3-NP) to rats results in selective striatal lesions and serves as an experimental model of Huntington's disease (HD). However, the effects of the 3-NP treatment are unpredictable and result in lesions of variable severity. The present study was aimed at further characterizing the variability of the striatal lesions induced by systemic administration of 3-NP using osmotic pumps. Hematoxylin-eosin (HE) and Nissl stains as well as immunohistochemical labelling of astrocytes and striatal neurones were performed to analyse the neurotoxic effects of 3-NP. In general, chronic systemic administration of 3-NP resulted in obvious bilateral striatal lesions, which ranged from mild to severe, together with a subtle, but detectable behavioural lesion. Severe type lesions showed marked neuronal loss and an increased expression of glial fibrillary acidic protein (GFAP) in astrocytes surrounding the lesion area, whereas in the core of the lesion GFAP-immunoreactivity was absent. The mild type lesion was characterized by a substantial loss of striatal neurones and an increased expression of GFAP-positive astrocytes throughout the lesion. In a number of 3-NP-treated animals, neither type of lesion was observed, although these animals demonstrated behavioural changes in the paw test compared to controls. In the striatum of these tested 3-NP-treated animals, compromised rk' neurones were detected, suggestive of subtle and early 3-NP-induced neuronal injury. Similar dark neurones were also detected in mild and severe lesions and were immunocytochemically characterized as gamma-aminobutyric acid (GABA) and substance P containing spiny neurones, which belong to the neuronal population that is affected in early HD. These results indicate that systemic administration of 3-NP to rats may result in a spectrum of striatal pathology of which the morphology of the mild type lesion resembles the characteristic HD neuropathology most closely.     

Long-term potentiation at excitatory amino acid synapses on midbrain dopamine neurons

Evidence suggests that a process analogous to long-term potentiation (LTP) may underlie the enhanced behavioural responses attending chronic administration of amphetamine and cocaine in animals (behavioural sensitization). Augmented excitatory amino acid (EAA)-mediated transmission at the level of midbrain dopamine neurons has been implicated as a change critical to the development of sensitization. Here we provide an initial demonstration that EAA synapses on dopamine neurons can undergo plasticity. Tetanic stimulation of the subthalamic nucleus induced a long-lasting increase (39.2 +/- 10.4%) in the amplitude of excitatory postsynaptic potentials recorded in dopamine neurons of the substantia nigra. This LTP, which did not occur in the presence of NMDA antagonists, may constitute the mechanism that lies at the heart of sensitization.     

Quality of Life following Radical Surgical Treatment of Gastric Carcinoma

Quality of life (QOL) in patients with gastric cancer who underwent total gastrectomy has so far not been studied using the EORTC QLQ-C30 (Quality of Life Core Questionnaire of the European Organization for Research and Treatment of Cancer) as a standardized European QOL instrument. The aim of this study was to evaluate the effect of radical procedures such as extensive lymph node resection and combined resection of adjacent organs on patients' QOL. From 1992 to 1996, 152 patients underwent total gastrectomy. All patients alive on July 1, 1996 were included in the study (77/152). For assessing QOL, the EORTC QOL questionnaire QLQ-C30 version 2.0 and a validated gastric cancer module were sent home to the patients for self-completion. The response rate was 91%. It was possible to evaluate the questionnaires of 62 patients who had undergone resection with curative intent including 13 extended gastrectomies (21%). Of the 62 resections, 50 were combined with D2 lymphadenectomy (80.6%). The global health status was not negatively influenced by D2 lymphadenectomy and extended gastrectomy. Patients with splenectomy were more affected by treatment than patients without splenectomy. Radical gastrectomy combined with D2 lymphadenectomy is the treatment of choice for gastric cancer patients, concerning not just survival but QOL as well.