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71.
Several age-related alterations occur at the cellular level in the immune system leading to a decrease in the immune response. The present study was designed to determine the effect of L-carnitine on impaired neutrophil functions of aged rats. For this reason, superoxide anion radical production, chemotaxis and phagocytic activity were studied in the neutrophils obtained from the peripheral blood of young and old rats. We orally gavaged L-carnitine (50 mg/kg b.w. per day) or control vehicle into young (2 months) and aged (24 months) rats for 30 consecutive days. The neutrophils of aged rats exhibited an increase in superoxide anion production and decline in phagocytosis and chemotaxis when compared with that in young rat neutrophils. Superoxide anion production in aged rats was significantly decreased by L-carnitine treatment which was accompanied with a significant enhancement of chemotactic and phagocytic activity being restored to control levels. These findings demonstrated that L-carnitine is capable of restoring the age-related changes of neutrophil functions. 相似文献
72.
73.
Surface chemistry modulates focal adhesion composition and signaling through changes in integrin binding 总被引:10,自引:0,他引:10
Biomaterial surface properties influence protein adsorption and elicit diverse cellular responses in biomedical and biotechnological applications. However, the molecular mechanisms directing cellular activities remain poorly understood. Using a model system with well-defined chemistries (CH3, OH, COOH, NH2) and a fixed density of the single adhesive ligand fibronectin, we investigated the effects of surface chemistry on focal adhesion assembly and signaling. Surface chemistry strongly modulated integrin binding and specificity—5β1 integrin binding affinity followed the pattern OH>NH2=COOH>CH3, while integrin Vβ3 displayed the relationship COOH>NH2OH=CH3. Immunostaining and biochemical analyses revealed that surface chemistry modulates the structure and molecular composition of cell-matrix adhesions as well as focal adhesion kinase (FAK) signaling. The neutral hydrophilic OH functionality supported the highest levels of recruitment of talin, -actinin, paxillin, and tyrosine-phosphorylated proteins to adhesive structures. The positively charged NH2 and negatively charged COOH surfaces exhibited intermediate levels of recruitment of focal adhesion components, while the hydrophobic CH3 substrate displayed the lowest levels. These patterns in focal adhesion assembly correlated well with integrin 5β1 binding. Phosphorylation of specific tyrosine residues in FAK also showed differential sensitivity to surface chemistry. Finally, surface chemistry-dependent differences in adhesive interactions modulated osteoblastic differentiation. These differences in focal adhesion assembly and signaling provide a potential mechanism for the diverse cellular responses elicited by different material properties. 相似文献
74.
75.
We analyzed the kinetics of heart rate (HR) response during incremental treadmill exercise in thirteen master runners (62 +/- 1 yr). The HR/running speed (HR/S) relationship showed the existence of a point of downward deflection (HR(d)) in only approximately 31% of the subjects. Resting echocardiographic evaluations showed similar heart dimensions in all of the subjects. In conclusion, HR does not seem to show a curvilinear response (downward deflection) in most aged athletes. 相似文献
76.
Prediction of postoperative morbidity after lung resection using an artificial neural network ensemble 总被引:4,自引:0,他引:4
OBJECTIVE: To propose an ensemble model of artificial neural networks (ANNs) to predict cardio-respiratory morbidity after pulmonary resection for non-small cell lung cancer (NSCLC). METHODS: Prospective clinical study was based on 489 NSCLC operated cases. An artificial neural network ensemble was developed using a training set of 348 patients undergoing lung resection between 1994 and 1999. Predictive variables used were: sex of the patient, age, body mass index, ischemic heart disease, cardiac arrhythmia, diabetes mellitus, induction chemotherapy, extent of resection, chest wall resection, perioperative blood transfusion, tumour staging, forced expiratory volume in 1s percent (FEV(1)%), and predicted postoperative FEV(1)% (ppoFEV(1)%). The analysed outcome was the occurrence of postoperative cardio-respiratory complications prospectively recorded and codified. The artificial neural network ensemble consists of 100 backpropagation networks combined via a simple averaging method. The probabilities of complication calculated by ensemble model were obtained to the actual occurrence of complications in 141 cases operated on between January 2000 and December 2001 and a receiver operating characteristic (ROC) curve for this method was constructed. RESULTS: The prevalence of cardio-respiratory morbidity was 0.25 in the training and 0.30 in the validation series. The accuracy for morbidity prediction (area under the ROC curve) was 0.98 by the ensemble model. CONCLUSION: In this series an artificial neural network ensemble offered a high performance to predict postoperative cardio-respiratory morbidity. 相似文献
77.
Alvarez M García F Martínez NM Hernández Quero J Louwagie J De Brauwer A Maroto MC 《Journal of medical virology》2004,73(2):151-157
The changes in viral load and CD4(+) count at 3 and 6 months in a group of 166 HIV-infected patients was evaluated. The new therapy was chosen based on the medical history procedures for 70 patients, and in 96 patients it was guided by the partial or complete result of the line probe assay (LiPA) HIV RT and Protease resistance tests. The absolute difference from the baseline of the log viral load at 3 and 6 months was significantly different between the two groups when adjusted for baseline viral load (P < 0.0001) and stayed significant when intention-to-treat analysis was carried out (P < 0.001). The absolute difference of the CD4(+) count was not significantly different when adjusted for baseline CD4(+) (P = 0.854, 3 months; P = 0.06, 6 months). The proportion of patients with a viral load =200 cp/ml in the medical history group (14.5%, 3 months; 15.2%, 6 months) was significantly different from the proportion of responders in the LiPA group (28.7%, 3 months, P = 0.03; 34.7%, 6 months, P = 0.008). In the intention-to-treat population, the difference between the two groups remained significant (P = 0.01). There was no statistical difference between the two groups in terms of adherence (P = 0.88), number of drug failures (P = 0.12) and for the time since starting treatment (in years) (P = 0.48), but there was a significant difference for the number of new drugs in the new regimen (P < 0.0001) and for the pill burden of the treatment (P = 0.0006). A higher antiretroviral HIV treatment success guided by the LiPA HIV genotyping system than that based on the medical history only is reported. Of note, this study reached the same conclusions as previous studies, which all used sequencing. 相似文献
78.
Pérez-Costas E Meléndez-Ferro M Pérez-García CG Caruncho HJ Rodicio MC 《Journal of chemical neuroanatomy》2004,27(1):7-21
The expression of reelin, a large extracellular matrix glycoprotein, was studied in the brain of pre-spawning adult sea lampreys by immunohistochemistry using two monoclonal antibodies against this protein. Reelin immunoreactive (reln-ir) neurons were observed in the olfactory bulb, and pallial and subpallial regions in the telencephalon. In the diencephalon, reln-ir cells were observed in some hypothalamic nuclei, in the nucleus of Bellonci, and in the habenula. In the mesencephalon, this protein was detected in several nuclei related with the centrifugal visual system, although the optic tectum was devoid of immunoreactivity. The hindbrain showed several nuclei with immunopositive neurons, including the branchiomeric nerve motor nuclei and also some groups of non-giant cells of the reticular formation. The rostral spinal cord showed some immunopositive neurons mainly located in lateral and ventral positions. Overall, the pattern of distribution of reelin in the adult sea lamprey correlates with the previously reported in other adult vertebrates. Furthermore, the wide distribution of reelin in the adult lamprey brain is consistent with a possible existence of different roles for this protein not related with development in the central nervous system (CNS) of vertebrates (i.e. neuronal plasticity and/or maintenance). 相似文献
79.
The role of histopathology for diagnosing celiac disease (CD) has been recently challenged. However, based in our experience with roughly 4,600 distal duodenal and jejunal biopsies in children it is apparent that appropriate biopsy site, handling, processing, and microscopic evaluation result in a consistent pattern of microscopic changes which allows strong clinical-pathologic correlation. A simple way for establishing the villous/crypt (V/C) ratio is proposed. Normal mucosa displays a V/C ratio of 2.5 or more. Villous atrophy is then graded according to the V/C ratio as follows: Grade 1: 2.5-2; Grade 2: 1-2; Grade 3: 1-0.5, and Grade 4: less than 0.5. The grading should be done in areas of the biopsy where at least 2 to 3 crypts are present in almost its full length. CD disease was consistently associated with villous atrophy grades 3 and 4, which fully recovered or maintained Grade 1 after gluten-free diet. Grade 2 biopsies were rare and related to incomplete gluten-free diet. Patchy lesions were never seen as were patients with normal biopsies later developing mucosal atrophy. Histopathologic evaluation of mucosal biopsies to rule out CD requires adequate biopsy site (distal duodenum or proximal jejunum), and proper handling (oriented material), processing (cutting on edge) and interpretation. The proposed villous atrophy grading may help to adequately compare experiences from different centers as well as to reconcile apparent different findings in separate biopsies. In children histopathology keeps on having a central role for CD diagnosis. 相似文献
80.
In order to evaluate nutritional status by anthropometry, a group of elderly (60 to 83 years old) was studied: 63 institutionalized and 37 non-institutionalized elderly from Valencia city, Venezuela. Weight, height, triceps skinfold and mid-arm circumference were measured and the body mass index (weight/height2) was calculated. The average age for the institutionalized group was 77.3 +/- 7.5 years old and 69.5 +/- 7.6 years old for the free-living elderly group. Tricipital skinfold (TSF) and mid-arm circumference (MAC) means were within the normal reference range for both groups, without significant differences by sex. Body mass index (BMI) was higher in the institutionalized group. Lower BMI and MAC were found in older elderly (> or =80 y). According to the nutritional classification by BMI, 16% of nutritional deficit, 45% of normal status and 39.7% with of excess weight were found in institutionalized elderly; while in free-living elderly, prevalences were 8%, 62% and 29.7% respectively. Even though normal nutritional status was highly prevalent, institutionalized elderly showed higher prevalences of nutritional alterations (underweight and overweight). 相似文献