Structural characterization of (In,Ga)As quantum dots in a GaAs matrix.
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Biomedical subjects
Publications and source records attributed to P Werner.
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The importance of autonomy and choice to nursing home residents' well-being has been well established. This paper examines the complex role of regulation as it affects the autonomy of nursing home residents. Nonstandardized interviews with residents, family members, nursing staff members, and administrators were conducted at three nursing homes in suburban Maryland. These anecdotal interviews identified the most problematic areas where regulations enforce barriers to autonomy and control. These areas include: scheduling of activities of daily living, food portions, physical environment, and documentation. Suggestions for possible improvements are discussed.
Recent reports have stressed an accumulation of iron and enhanced levels of lipid peroxides in the substantia nigra as essential factors in the pathogenesis of Parkinson's disease. Many investigators believe that tissue antioxidants, such as ascorbate, play a protective role. On the other hand, L-DOPA, which is used extensively to treat Parkinson's disease, undergoes autoxidation (as does dopamine), thus generating reactive oxygen species. We studied lipid peroxidation (LPO) in mouse brain homogenates and evaluated the effects of iron (5 microM ferric-ADP), L-DOPA, dopamine and ascorbic acid, added either alone or in mixtures. Ascorbic acid was used at levels of 0.5 mM or 2.0 mM, approximating those present normally in brain. LPO in brain homogenates was stimulated by the addition of either ascorbic acid or iron, as well as by a combination of the two, in agreement with other reports. The effects of L-DOPA were complex: L-DOPA strongly suppressed LPO both with and without added iron-ADP. In sharp contrast, however, when ascorbic acid was also added, L-DOPA no longer suppressed LPO; indeed, L-DOPA stimulated LPO in the presence of added iron and ascorbic acid. Dopamine behaved similarly to L-DOPA. When ascorbic acid was studied over a concentration range, LPO was stimulated at 0.5, 1, 2 or 3 mM, with or without added iron and/or dopamine; 5 and 10 mM ascorbic acid were either not as effective or suppressed LPO below control levels. Deferoxamine, a powerful iron chelator, greatly suppressed LPO under all conditions, as did diethylenetriaminepentaacetate (DTPA). Added superoxide dismutase had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)
We have tried to find a reliable panel of markers that would allow distinction between mesotheliomas and carcinomas metastatic to the pleura. In a prospective study, we evaluated 54 pleural effusions: In 27 of the patients, a diagnosis of histologically proven metastatic carcinoma was subsequently established, 7 patients had biopsy-proven malignant mesotheliomas and 20 had benign, reactive effusions whose benign etiologies were established by more than 2 years clinical follow-up. The MAb (monoclonal antibody) IOB3 proved to be diagnostic for carcinomas in all 27 cases (100%), whereas CEA (carcinoembryonic antigen) expression was found in only 22 out of 27 (81%). None of the malignant mesotheliomas, nor benign reactive mesothelial cells reacted with these two markers. All carcinomas, as well as one malignant mesothelioma, reacted with the MAb HEA125. Antibodies against 12 single cytokeratins, vimentin, and EMA (epithelial membrane antigen) were not helpful in the differentiation between malignant mesotheliomas and malignant carcinomatous pleural effusions. We conclude that adding the antibody IOB3 to the CEA assay should allow a reliable differentiation between these two entities.
Two hundred participants (mean age = 80 years) from five senior day-care centers were included in a study of agitation. Staff members at the centers and participants' relatives rated the frequency with which participants displayed agitated behaviors, via an expanded version of the Cohen-Mansfield Agitation Inventory. The most frequent behaviors noted were general restlessness, repetitious sentences, verbal interruptions, and pacing. A three-factor solution for staff members' ratings included (a) physically nonaggressive behaviors, including general restlessness and pacing; (b) verbally agitated behaviors, including complaining and constant requests for attention; and (c) aggressive verbal behaviors, including cursing and temper outbursts. A three-factor solution for relatives' ratings included (a) physically nonaggressive behaviors, including general restlessness and pacing; (b) verbally agitated behaviors, including constant requests for attention and related interruptions; and (c) aggressive behaviors, including cursing, grabbing, kicking, and pushing. The syndromes of both models showed similarity to the factors found in a nursing home population, although differences were also apparent.
The consequences of a single bout of heavy eccentric exercise with and without repeated concentric exercises on MRI images, serum CK levels and markers of inflammation were studied. Two groups (ECC and ECCON), each consisting of 18 male volunteers, performed 70 eccentic contractions of the quadriceps femoris muscle. The study group (ECCON) performed additional concentric contractions on a dynamometer (Cybex II+) one day before and two hours, 1, 2, 3, 6 and 9 days after eccentric loading. Serum levels of creatine kinase (CK) were examined as a function of time, and correlated with measurements of magnetic resonance imaging (MRI) of the involved muscle groups. T2-weighted images of the thigh muscles were studied. Serum C-reactive protein, complement factors C3c and C4, haptoglobin and transferrin were measured as markers of inflammation. Additional concentric contractions (ECCON group) significantly increased CK, compared to the ECC group. However, it has no apparent effect on MRI signal intensity changes, which were of equal magnitude in the loaded vastus intermedius and deep parts of the vastus lateralis in both groups. Likewise, the serum markers of inflammation of the exercised muscles appeared to be absent. Based on MRI-images, additional concentric contractions had no statistically significant effect on muscle damage and breakdown of connective tissue. The five-fold increase in CK in the ECCON group could be a reflection of "massaging out" of the CK from the muscles into the circulation by additional concentric exercises. However, it could also be an indication for a superior sensitivity of assessing muscle fiber damage in comparison to the MRI.
OBJECTIVE: The order in which cognition and the ability to perform activities of daily living (ADLs) are lost in an institutionalized aged population was examined. Understanding the order of loss of function is important for preparing caregivers and planning of care. METHOD: The conditional probabilities of the inability to perform activity A when there exists the inability to perform activity B were explored in secondary analyses of cross-sectional data describing 408 nursing home residents. Residents' abilities to perform ADLs were rated by nursing staff using Linn and Linn's Rapid Disability Rating Scale (RDRS-2); cognitive functioning was rated by social workers and nursing staff using a modified version of Reisberg et al.'s Brief Cognitive Rating Scale (BCRS, with 4 axes: orientation, concentration, recent memory, and past memory). RESULTS: The results regarding ADLs confirm previous findings of a natural order of loss of ability (from the one lost first to last): bathing, dressing, grooming, toileting, walking, and eating. The examination of order in the loss of concentration, recent memory, past memory, and orientation revealed that these seem to be lost concurrently when the cutpoint was 3 (i.e., relatively normal functioning vs. moderate and severe dementia). When the cutpoint was 6 (i.e., severe dementia vs. higher levels of functioning), the order that emerged was: recent memory, past memory, concentration, and orientation. CONCLUSIONS: Although there is a significant relationship between loss of ability to perform ADLs and stage of cognitive impairment, the loss of any specific ADL is not uniquely related to any one stage of cognitive deterioration in this diverse population. This may be explained by the high prevalence of disease in this institutionalized population, as exemplified by the 60% suffering from arthritis and the 17% suffering from neurological disorders other than dementia.
Increasing evidence suggests a role for activated T cells and cytokines in the regulation of eosinophilic inflammation in asthma. In this study, we investigated the distribution of leukocytes, lymphocytes, their activation state, and the cytokine profile in BAL from 10 atopic asthmatics with positive skin prick tests and elevated specific IgE levels to birch or grass pollen. Using segmental allergen challenge, 250 PNU of the appropriate allergen or saline were instilled into different segments, which were lavaged 10 min (10 min) and 18 h (18 h) after allergen challenge or 18 h after saline challenge (C). In peripheral blood the number of neutrophils and activated IL-2R+/CD4+ T cells increased significantly 18 h after allergen provocation; there was no change in eosinophils, other leukocytes, or lymphocyte subsets. In contrast, numbers of eosinophils, neutrophils, and IL-2R+/CD4+ T cells increased significantly in BAL samples at 18 h. The numbers of neutrophils and eosinophils were not significantly different in the lavage performed at 10 min and at C. Analysis of cytokines in concentrated BAL fluid revealed significantly increased levels of IL-5, IL-2, IL-1, TNF-alpha, IL-6, IL-8, and GM-CSF, but not of IL-4 and IFN-gamma at 18 h compared with those at C and at 10 min. The correlation between IL-5 levels, eosinophil numbers, and activated T cells supports a role for T-cell-derived IL-5 in causing tissue eosinophilia in allergic asthma.
This article describes a walking program that was implemented at a 550-bed long-term care facility. The program was developed in order to promote functional mobility in the frail nursing home population. The aim of the program is to establish a nursing procedure that focuses on the individual resident's need to walk, and to improve or maintain the ambulatory status of the frail elderly. Twenty nursing home residents from the first three units on which the program was implemented were evaluated before and after the implementation of the program. The data show that the participants improved their ambulatory status after participating in the walking program. This improvement was accompanied by a decrease in the proportion of residents falling.
The BiPAP-System is a useful ventilatory support for patients with severe sleep apnea and need for high inspiratory pressure. Using the BiPAP as a full ventilatory support is new due to the recent addition of a timed control modus and individual control of inspiratory time. We used the new BiPAP ST-System in one young men with Duchenne-disease, one man with heredo ataxia (Friedreich), one women with spinal muscular atrophy, one man with central sleep apnea due to brainstem infarction as well as two women and one men with severe kyphoscoliosis. All patients had a significant hypoventilation and hypoxemia at night, which was documented by polysomnography. Mechanical ventilation at night with nasal BiPAP increased the baseline oxygen saturation (SaO2) by an average of 11.9% in all seven patients. The frequency of desaturations below 90% diminished by an average of 81%. The lowest SaO2 measured increased by 28% in all seven patients combined. Rhinitis due to the dryness of the inspired air were noticed in only two patients. Two other patients needed adaptation to the customized mask. The nasal BiPAP-System using the T-mode is a useful device to support ventilation at night and thus it could replace ventilatory support by the IPPV-mode in many patients.
An observational study was conducted to describe the physical and social environment of sleep of 16 highly agitated and cognitively impaired nursing home residents, and the relationships between manifestations of agitation and sleep. Results showed that nursing home residents were more likely to be observed asleep when alone, in their own rooms, and between 9 p.m. and 5 a.m. Considerable amounts of sleep were also observed during the day. Great individual variation was observed in the presence of sleep-related disorders, although a tendency was observed for more fragmented sleep during the day hours. Almost all the agitated behaviors observed decreased immediately after sleep. Similar to findings of objective studies, much individual variation was found in sleep patterns and sleep pathology of cognitively impaired and highly agitated nursing home residents. Findings suggest that agitation may be exacerbated by fatigue.
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The effect of 3,4-dihydroxyphenylalanine (L-dopa) treatment on the ability of intact human cells to metabolize substrates for mitochondrial oxidative phosphorylation was studied in embryonic fibroblasts. Treatment with L-dopa (100-400 microM) for 48 h significantly reduced the oxidation of pyruvate but had no effect on succinate oxidation. The effect was dose-dependent and was still present 2 days after removal of L-dopa. Ascorbic acid (200 microM) protected the cells from the effects of L-dopa; ascorbate alone enhanced pyruvate but not succinate oxidation.
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Whether or not a reported deficiency in brain mitochondrial complex I activity in Parkinson's disease represents a defect encompassing other organs or tissues has been a source of some controversy. We have examined mitochondrial respiration in fibroblasts from patients with Parkinson's disease by measuring the oxidative decarboxylation of [2-14C]pyruvate and [1,4-14C]succinate. We report that oxidation of pyruvate but not succinate was significantly reduced in fibroblasts from Parkinson patients when compared to healthy controls. These observations support the view that a widespread deficit in mitochondrial respiration exists in Parkinson's disease. Fibroblast cultures, moreover, are a source of affected proliferating cells, which can be used for in vitro studies of the nature of the respiratory defect and for testing of pharmacological interventions to correct the deficiency.