Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 9 de 9
Filter
1.
Neurocase ; 22(2): 135-44, 2016.
Article in English | MEDLINE | ID: mdl-26237526

ABSTRACT

Physical activity (PA) and cardiorespiratory fitness (CRF) are associated with successful brain and cognitive aging. However, little is known about the effects of PA, CRF, and exercise on the brain in the oldest-old. Here we examined white matter (WM) integrity, measured as fractional anisotropy (FA) and WM hyperintensity (WMH) burden, and hippocampal (HIPP) volume of Olga Kotelko (1919-2014). Olga began training for competitions at age of 77 and as of June 2014 held over 30 world records in her age category in track-and-field. We found that Olga's WMH burden was larger and the HIPP was smaller than in the reference sample (58 healthy low-active women 60-78 years old), and her FA was consistently lower in the regions overlapping with WMH. Olga's FA in many normal-appearing WM regions, however, did not differ or was greater than in the reference sample. In particular, FA in her genu corpus callosum was higher than any FA value observed in the reference sample. We speculate that her relatively high FA may be related to both successful aging and the beneficial effects of exercise in old age. In addition, Olga had lower scores on memory, reasoning and speed tasks than the younger reference sample, but outperformed typical adults of age 90-95 on speed and memory. Together, our findings open the possibility of old-age benefits of increasing PA on WM microstructure and cognition despite age-related increase in WMH burden and HIPP shrinkage, and add to the still scarce neuroimaging data of the healthy oldest-old (>90 years) adults.


Subject(s)
Athletes/psychology , Cognition/physiology , Hippocampus/anatomy & histology , White Matter/anatomy & histology , Accelerometry , Aged , Aged, 80 and over , Anisotropy , Athletes/history , Diffusion Tensor Imaging , Famous Persons , Female , History, 20th Century , History, 21st Century , Humans , Middle Aged , Neuropsychological Tests
2.
Microsc Microanal ; 14(5): 469-77, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18793491

ABSTRACT

The ability of electron microscopes to analyze all the atoms in individual nanostructures is limited by lens aberrations. However, recent advances in aberration-correcting electron optics have led to greatly enhanced instrument performance and new techniques of electron microscopy. The development of an ultrastable electron microscope with aberration-correcting optics and a monochromated high-brightness source has significantly improved instrument resolution and contrast. In the present work, we report information transfer beyond 50 pm and show images of single gold atoms with a signal-to-noise ratio as large as 10. The instrument's new capabilities were exploited to detect a buried Sigma3 {112} grain boundary and observe the dynamic arrangements of single atoms and atom pairs with sub-angstrom resolution. These results mark an important step toward meeting the challenge of determining the three-dimensional atomic-scale structure of nanomaterials.

3.
Toxicology ; 108(1-2): 129-40, 1996 Apr 15.
Article in English | MEDLINE | ID: mdl-8644111

ABSTRACT

Metallothionein (MT) is a thiol rich protein that has been well characterized for its ability to bind and sequester heavy metal cations, free radicals and other reactive toxicants. In addition to induction by these stressors, MT gene expression is upregulated by several cytokines of the acute phase response. In previous work, we have shown that MT can alter aspects of lymphocyte function. MT alone induces modest proliferation of unfractionated splenocytes and acts synergistically with T cell- and B cell-specific mitogens. In contrast, MT inhibits humoral responsiveness in vivo and reduces in vitro T cell responses to processed antigen. In this report, we describe the effects of MT on specific lymphocyte subpopulations in order to further characterize the mechanism of MT-mediated alterations of immune activity. MT binds to the plasma membrane of both T and B lymphocytes, but, in the absence of a costimulatory agent, MT induces lymphoproliferation only in B cells. MT also enhances the capacity of naive B lymphocytes to differentiate into plasma cells. These results demonstrate differential immunomodulatory activities of MT and may explain some of the diverse immunoregulatory effects associated with exposure to environmental toxins.


Subject(s)
Lymphocytes/drug effects , Metallothionein/pharmacology , Animals , B-Lymphocytes/drug effects , Cell Differentiation/drug effects , Cell Division/drug effects , Cell Membrane/drug effects , Ethylmaleimide/antagonists & inhibitors , Ethylmaleimide/toxicity , Lymphocytes/metabolism , Metallothionein/biosynthesis , Mice , Mice, Inbred BALB C , Mice, Inbred C3H , Plasma Cells/drug effects , Spleen/cytology , Spleen/drug effects , T-Lymphocytes/drug effects
5.
J Toxicol Environ Health ; 45(4): 397-413, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7643428

ABSTRACT

Metallothionein (MT) is a thiol-rich protein that is rapidly induced by exposure to heavy metal cations. We have previously demonstrated that exogenous MT stimulates murine splenocytes to proliferate, but inhibits humoral responses to antigen. These observations suggest that metallothionein released from cells has a complex role in heavy metal-mediated immune dysfunction. Here we examine one possible mechanism by which MT mediates suppression of humoral immunity. Exposure of macrophages to 20 microM MT did not affect their ability to engulf opsonized sheep erythrocytes, but in the presence of 20 microM MT, peritoneal macrophages were stimulated to produce increased levels of oxygen radicals. These results correlated with observations that while macrophage phagocytosis of opsonized Candida albicans was unaltered by the presence of exogenous MT, killing of the engulfed yeast cells was dramatically enhanced by 20 microM MT. Amounts of free cadmium and zinc equimolar to that added as Zn,Cd-MT had no effect on candidacidal activity. MT was also found to significantly decrease lymphocyte proliferation mediated by macrophage activity. Biotinylated MT (MT-b) bound specifically to the plasma membranes of these macrophages, suggesting that membrane-associated molecules of the macrophage may transduce a signal mediated by MT binding. These results demonstrate that macrophages are a sensitive target for MT-mediated immunomodulation and that some of the consequences of the MT interaction with macrophages may be alterations in the capacity to produce an effective immune response and increased extracellular exposure to damaging free radicals.


Subject(s)
Lymphocyte Activation/drug effects , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/physiology , Metallothionein/pharmacology , T-Lymphocytes/drug effects , Animals , Antibody Formation/drug effects , Candida albicans/drug effects , Candida albicans/growth & development , Macrophages, Peritoneal/metabolism , Metallothionein/metabolism , Mice , Mice, Inbred BALB C , Phagocytosis/drug effects , Superoxides/metabolism
6.
Toxicology ; 85(2-3): 161-77, 1993 Dec 31.
Article in English | MEDLINE | ID: mdl-8303711

ABSTRACT

Extracellular metallothionein (Zn,Cd-MT) has previously been shown to be a potent inducer of lymphocyte proliferation and to synergize with polyclonal activators in proliferation assays. In this report, the effects of metallothionein on the development of humoral responsiveness are examined. In vivo, the specific anti-ovalbumin (OVA) IgG response was diminished by co-injection of Zn, Cd-MT, while total IgG levels remained unchanged. A similar reduction was also observed when Zn,Cd-MT was administered during the development of an anti-sheep red blood cell (sRBC) humoral response. When amounts of Zn and Cd equimolar to that associated with the Zn, Cd-MT were co-injected with OVA, humoral responsiveness was enhanced, in contrast to the suppression seen with Zn, Cd-MT. Apothionein lacking the available thiols associated with native Zn, Cd-MT had no effect on the development of humoral immunity. These results point to the thiols associated with the protein as the important determinants in the observed immunosuppression and this is supported by the capacity of UC1MT, a new monoclonal anti-MT antibody, to reverse MT mediated immunosuppression. No evidence was found to suggest that Zn,Cd-MT was interacting directly with OVA. Finally, in vitro experiments with LPS-stimulated splenocyte production of IgM correlated with the in vivo observations of Zn,Cd-MT. These data provide evidence for a significant role for MT in the development of metal-mediated immunomodulation and suggest that MT may also possess immunomodulatory functions under circumstances where MT is synthesized in the absence of heavy metal stress. Furthermore, it may be possible to take advantage of this system to exogenously manipulate the development of the immune response.


Subject(s)
Adjuvants, Immunologic/pharmacology , Antibody Formation/drug effects , Metallothionein/pharmacology , Animals , Cross Reactions , Horses , Immunoglobulin G/immunology , Liver/metabolism , Metallothionein/immunology , Mice , Mice, Inbred BALB C , Ovalbumin/immunology , Rabbits
7.
Coll Rev ; 10(1): 29-60, 1993.
Article in English | MEDLINE | ID: mdl-10183117

ABSTRACT

Physicians take into account many factors when making referral decisions, primarily provider expertise, good communication and good patient care. This professional paper will show that provider expertise and patient care are the most important factors in referral decisions, and that physicians rely primarily on direct experience for the information necessary to make a referral choice.


Subject(s)
Advertising/methods , Attitude of Health Personnel , Interprofessional Relations , Neurology , Referral and Consultation , Cluster Analysis , Humans , Program Evaluation , Referral and Consultation/statistics & numerical data , Surveys and Questionnaires , United States
9.
Nufusbil Derg ; 2-3: 47-70, 1981.
Article in Turkish | MEDLINE | ID: mdl-12159431

ABSTRACT

PIP: This article presents a somewhat speculative picture of fertility-limiting behavior within the duofocal family in Turkey, supported with data from the 1968 survey, other research on fertility limitation, and from ethnographic studies. The focus was on the ability of the woman to fully realize the potential for autonomy afforded by the duofocal family structure in attempting fertility limitation. This was shown to be determined largely by the opportunity structure to which a woman had access and by the characteristics and boundaries of the female sphere as subjectively defined by the woman. Although this autonomy is in some ways greater in metropolitan areas than elsewhere, even that setting does not permit the Turkish woman to enjoy the full realization of her potential for autonomy afforded by the sexual dualism of Turkish society and the duofocality of Turkish family structure. (author's modified)^ieng


Subject(s)
Birth Rate , Psychology, Social , Psychology , Socioeconomic Factors , Asia , Asia, Western , Behavior , Demography , Developing Countries , Economics , Fertility , Population , Population Dynamics , Social Sciences , Turkey
SELECTION OF CITATIONS
SEARCH DETAIL