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991.
992.
Anthropologists frequently use musculoskeletal stress markers to reconstruct past activity patterns. Yet, researchers have called into question the reliability of muscle marker measurements in part because body size and age affect muscle marker scores. In this study, the author examined an aggregate upper limb muscle marker to determine if after controlling for the effects of body size and age, one could reconstruct activity patterns of a prehistoric Amerind population. Analyses were made of a sample of 102 (43 males, 59 females) prehistoric central California Amerinds. Muscle markers were measured using two-point observer rating scales; body size was measured by humeral articular surfaces; age and sex were determined previously through standard procedures. Using sex separated rankings and partial correlations, disaggregated muscle markers were examined for correlations with age and size to determine if specific muscle markers may be useful in pinpointing to activity patterns. Aggregate upper limb muscle marker correlated with: age, r = 0.44; humeral size, r = 0.44; and sex, r = 0.43; Ps < 0.001. Older individuals had greater muscle markers, as did larger individuals, and males. Rankings seemed to be confounded by the effect size had on the muscle markers. However, based on partial correlations controlling for size and age, the differences that remained between males and females could be used to reconstruct male activities of throwing in hunting and interpersonal aggression acts.  相似文献   
993.
We investigated the geographic distribution and the relationship with neighborhood wealth of underweight and overweight in India. Using multilevel modeling techniques, we calculated state-specific smoothed shrunken state residuals of overweight and underweight, neighborhood and state variation of nutritional status, and the relationships between neighborhood wealth and nutritional status of 76,681 women living in 3204 neighborhoods in 26 Indian states. We found a substantial variation in overweight and underweight at the neighborhood and state levels, net of what could be attributed to individual-level factors. Neighborhood wealth was associated with increased levels of overweight and decreased levels of underweight, and was found to modify the relationship between personal living standard and nutritional status. These findings suggest that interventions to address the double burden of undernutrition and overnutrition in India must take into account state and neighborhood characteristics in order to be successful.  相似文献   
994.
Platelets contribute to the development of metastasis, the most common cause of mortality in cancer patients, but the precise role that anti-platelet drugs play in cancer treatment is not defined. Metastatic tumor cells can produce platelet alphaIIb beta3 activators, such as ADP and thromboxane A(2) (TXA(2)). Inhibitors of platelet beta3 integrins decrease bone metastases in mice but are associated with significant bleeding. We examined the role of a novel soluble apyrase/ADPase, APT102, and an inhibitor of TXA(2) synthesis, acetylsalicylic acid (aspirin or ASA), in mouse models of experimental bone metastases. We found that treatment with ASA and APT102 in combination (ASA + APT102), but not either drug alone, significantly decreased breast cancer and melanoma bone metastases in mice with fewer bleeding complications than observed with alphaIIb beta3 inhibition. ASA + APT102 diminished tumor cell induced platelet aggregation but did not directly alter tumor cell viability. Notably, APT102 + ASA treatment did not affect initial tumor cell distribution and similar results were observed in beta3-/- mice. These results show that treatment with ASA + APT102 decreases bone metastases without significant bleeding complications. Anti-platelet drugs such as ASA + APT102 could be valuable experimental tools for studying the role of platelet activation in metastasis as well as a therapeutic option for the prevention of bone metastases.  相似文献   
995.
The emergence of strains of Schistosoma resistant to praziquantel has drawn attention to the search for new schistosomacide drugs. Imidazolidinic derivatives have performed outstandingly against adult S. mansoni worms when evaluated in vitro. The molecular modification of imidazolidine by way of bioisosteric replacement gives rise to variations in its biological response. This study verifies the potential of substituent groups in the derivatives (Z)3-benzyl-5-(2-fluoro-benzylidene)-imidazolidine-2,4-dione NE4, 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin -2-ona PT5, 3-benzyl-5-(3-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one JT53; 3-benzyl-1-methyl-5-(4-methyl-benzylidene)-2-thioxo-imidazolidin-4-one JT63; 3-benzyl-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo -imidazolidin-4-one JT68; 3-(4-chloro-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT69; 3-(4-phenyl-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT72 by determining the viability in vitro of adult S. mansoni worms in the presence of these derivatives. The susceptibility of the worms obtained from mice and kept in culture in the presence of different concentrations was determined by way of schistosomacide kinetic, observed every 24 h over a period of eight days. The results show that the worms were more sensitive to the PT5 derivative at a concentration of 58 microM which killed 100% of the worms after 24 h of contact, also giving rise to alterations in the tegument surface of the worms with the formation of bubbles and peeling. These observations suggest a strong electronic contribution of the arylazo grouping in the biological response.  相似文献   
996.

Background  

The etiology and pathophysiology of chronic fatigue syndrome (CFS) remain inchoate. Attempts to elucidate the pathophysiology must consider sleep physiology, as unrefreshing sleep is the most commonly reported of the 8 case-defining symptoms of CFS. Although published studies have consistently reported inefficient sleep and documented a variable occurrence of previously undiagnosed primary sleep disorders, they have not identified characteristic disturbances in sleep architecture or a distinctive pattern of polysomnographic abnormalities associated with CFS.  相似文献   
997.
To determine whether solute transport across yeast membranes was facilitated, we measured the water and solute permeations of vacuole-derived and late secretory vesicles in Saccharomyces cerevisiae; all permeations were consistent with passive diffusive flow. We also overexpressed Fps1p, the putative glycerol facilitator in S. cerevisiae, in secretory vesicles but observed no effect on water, glycerol, formamide, or urea permeations. However, spheroplasts prepared from the strain overexpressing Fps1p showed enhanced glycerol uptake, suggesting that Fps1p becomes active only upon insertion in the plasma membrane.  相似文献   
998.
Glycogen storage disease type IIIa (GSD IIIa) is caused by a deficiency of glycogen debranching enzyme activity. Hepatomegaly, muscle degeneration, and hypoglycemia occur in human patients at an early age. Long-term complications include liver cirrhosis, hepatic adenomas, and generalized myopathy. A naturally occurring canine model of GSD IIIa that mimics the human disease has been described, with progressive liver disease and skeletal muscle damage likely due to excess glycogen deposition. In the current study, long-term follow-up of previously described GSD IIIa dogs until 32 mo of age (n = 4) and of family-owned GSD IIIa dogs until 11 to 12 y of age (n = 2) revealed that elevated concentrations of liver and muscle enzyme (AST, ALT, ALP, and creatine phosphokinase) decreased over time, consistent with hepatic cirrhosis and muscle fibrosis. Glycogen deposition in many skeletal muscles; the tongue, diaphragm, and heart; and the phrenic and sciatic nerves occurred also. Furthermore, the urinary biomarker Glc4, which has been described in many types of GSD, was first elevated and then decreased later in life. This urinary biomarker demonstrated a similar trend as AST and ALT in GSD IIIa dogs, indicating that Glc4 might be a less invasive biomarker of hepatocellular disease. Finally, the current study further demonstrates that the canine GSD IIIa model adheres to the clinical course in human patients with this disorder and is an appropriate model for developing novel therapies.Abbreviations: CCR, curly-coated retriever; CPK, creatine phosphokinase; GSD IIIa, glycogen storage disease type IIIa; Glc4, Glcα1-6Glcα1-4Glcα1-4GlcGlycogen storage disease type IIIa (GSD IIIa; OMIM, 232400) is an autosomal recessive disorder caused by mutations in the glycogen debranching enzyme gene (AGL), leading to various clinical signs. The tissues mainly affected are liver, heart, and skeletal muscle. Clinical manifestations include hypoglycemia, elevated serum concentrations of liver and muscle enzymes, hepatomegaly, growth retardation, muscle weakness, cardiac hypertrophy with arrhythmia risk, polycystic ovaries and neuropathy.15,17,29 Current treatments are mainly symptomatic and are not curative. The most frequently used therapies are dietary, such as providing uncooked corn starch to prevent hypoglycemia at young ages and high-protein diets, which have been shown to reverse the extent of cardiomyopathy associated with GSD IIIa.7,8,30,37 In addition, the use of medium-chain triglycerides has shown positive therapeutic effects in patients with GSD Ia and GSD IIIa.11,22 However, dietary therapies do not prevent the long-term complications of GSD IIIa, including hepatic cirrhosis, hepatocellular adenoma, hepatocellular carcinoma, cardiomyopathy, neuropathy, and myopathy.31An appropriate animal model is necessary to test novel therapies and address the long-term effects of GSD IIIa. Recently a mouse model for GSD III has been described that may prove beneficial in testing new therapies.19 However, the limitations of mouse models include a short lifespan that curtails the study of the long-term effects of novel treatments. In addition, a large animal model often mimics human disease more closely than do mouse models, as occurs in GSD type Ia dog models, which exhibit lactic acidosis similar to human patients, a characteristic that mouse models of GSD Ia lack.16 Therefore a naturally occurring large animal model for GSD IIIa may be more effective in terms of the development of new treatments than are available mouse models.GSD IIIa (OMIA, 001577) has been reported to occur in curly-coated retriever dogs (CCR) and is caused by a naturally occurring homozygous frameshift mutation in exon 32 that leads to the deletion of 126 amino acids at the C-terminus of glycogen debranching enzyme.12,40 The dogs in these previous studies proved to have abnormalities similar to those seen in humans affected with the disorder, namely progressive glycogen accumulation in muscle and liver, elevated liver and muscle enzymes (ALP, AST, creatine phosphokinase [CPK], and ALT), and eventual liver fibrosis. However, these animals were not followed beyond 16 mo of age in the earlier studies.12,40 The goal of the current study is to provide biochemical follow-up on these animals and analyze more extensively other tissues and organs involved in GSD IIIa in the dog model. A brief analysis of the naturally high protein diets of GSD IIIa dogs, as well as the effects of an increased protein diet in 2 dogs for the last few months of life, is included.We also include the analysis of a urinary biomarker, Glcα1–6Glcα1– 4Glcα1–4Glc (Glc4), which is a breakdown product of glycogen by α-amylase and neutral α-1,4-glucosidase.32 Elevated levels of Glc4 have been found in urine from patients with GSD types II, III, IV, VI, and IX and may correlate with disease advancement.1,18,24,32 To our knowledge, Glc4 has not been evaluated previously in dogs; we therefore here evaluated the utility of Glc4 as a biomarker of canine GSD IIIa. A correlation of Glc4 levels with liver enzyme concentrations in blood might indicate a role of Glc4 as a less-invasive biomarker for determining the advancement of liver disease in human and canine patients.  相似文献   
999.
Inhibition of the up-regulated telomerase activity in cancer cells has previously been shown to slow cell growth but only after prior telomere shortening. Previously, we have reported that, unexpectedly, a hairpin short interfering RNA specifically targeting human telomerase RNA rapidly inhibits the growth of human cancer cells independently of p53 or telomere length and without bulk telomere shortening (Li, S., Rosenberg, J. E., Donjacour, A. A., Botchkina, I. L., Hom, Y. K., Cunha, G. R., and Blackburn, E. H. (2004) Cancer Res. 64, 4833-4840). Here we have demonstrated that such telomerase RNA knockdown in cancer cells does not cause telomere uncapping but rather induces changes in the global gene expression profile indicative of a novel response pathway, which includes suppression of specific genes implicated in angiogenesis and metastasis, and is distinct from the expression profile changes induced by telomere-uncapping mutant template telomerase RNAs. These cellular responses to depleting telomerase in human cancer cells together suggest that cancer cells are "telomerase-addicted" and uncover functions of telomerase in tumor growth and progression in addition to telomere maintenance.  相似文献   
1000.
The activity of the enzymes of the central metabolic pathways has been the subject of intensive analysis; however, the Entner-Doudoroff (ED) pathway has only recently begun to attract attention. The metabolic response to edd gene knockout in Escherichia coli JM101 and PTS- Glc+ was investigated in gluconate and glucose batch cultures and compared with other pyruvate kinase and PTS mutants previously constructed. Even though the specific growth rates between the strain carrying the edd gene knockout and its parent JM101 and PTS- Glc+ edd and its parent PTS- Glc+ were very similar, reproducible changes in the specific consumption rates and biomass yields were obtained when grown on glucose. These results support the participation of the ED pathway not only on gluconate metabolism but on other metabolic and biochemical processes in E. coli. Despite that gluconate is a non-PTS carbohydrate, the PTS- Glc+ and derived strains showed important reductions in the specific growth and gluconate consumption rates. Moreover, the overall activity of the ED pathway on gluconate resulted in important increments in PTS- Glc+ and PTS- Glc+ pykF mutants. Additional results obtained with the pykA pykF mutant indicate the important contribution of the pyruvate kinase enzymes to pyruvate synthesis and energy production in both carbon sources.  相似文献   
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