Search results for "Biochemistry"
showing 10 items of 20172 documents
Transient focal cerebral ischemia significantly alters not only EAATs but also VGLUTs expression in rats: relevance of changes in reactive astroglia
2010
The involvement of plasma membrane glutamate transporters (EAATs - excitatory aminoacid transporters) in the pathophysiology of ischemia has been widely studied, but little is known about the role of vesicular glutamate transporters (VGLUTs) in the ischemic process. We analyzed the expression of VGLUT1-3 in the cortex and caudate-putamen of rats subjected to transient middle cerebral artery occlusion. Western blot and immunohistochemistry revealed an increase of VGLUT1 signal in cortex and caudate-putamen until 3 days of reperfusion followed by a reduction 7 days after the ischemic insult. By contrast, VGLUT2 and 3 were drastically reduced. Confocal microscopy revealed an increase in VGLUT2…
Dose-dependent osteoinductive effects of bFGF in rabbits.
2009
Growth factors lead to the induction of tissue regeneration in bone healing when coated on biomaterials. Basic fibroblast growth factor (bFGF) combines osteoinduction and neoangiogenesis. This study evaluated bFGF-coated hydroxylapatite implants in two experimental groups with 10 or 100 microg (n = 5 per group) compared with uncoated control implants in the rabbit patellar groove model. We observed an unexpected ineffectiveness compared to the control groups with no significant difference of bone growth after 35 days. However, all samples from the 100 microg experiment (control and coated implant) showed significantly stronger 19-25 day label than both 10 microg groups (control and coated i…
Differential effects of sex hormones on peri- and endocortical bone surfaces in pubertal girls.
2005
Context: The role of sex steroids in bone growth in pubertal girls is not yet clear. Bone biomarkers are indicators of bone metabolic activity, but their value in predicting bone quality has not been studied in growing girls. Objective: This study examines the association of sex hormones and bone markers with bone geometry and density in pubertal girls. Design: The study was designed as a 2-yr longitudinal study in pubertal girls. Measurements were performed at baseline and at 1and 2-yr follow-ups. Setting: The study was conducted in a university laboratory. Participants: A total of 258 10- to 13-yr-old healthy girls at the baseline participated. Methods:Peripheralquantitativecomputedtomogr…
Bone Mineral Density and Bone Metabolism in Diabetes Mellitus
1998
The effect of diabetes mellitus on bone metabolism and bone mineral density is discussed controversially. Diabetes mellitus due to an autoimmune process seems to be associated with low turnover osteopenia either in the animal model or in children and adolescents. A number of factors are discussed as being involved, but in this age group clinical symptoms are missing. Adult patients of either sex with IDDM show a reduced bone mineral density when measured at peripheral sites such as the distal forearm or the femoral neck, diabetic complications such as neuropathy and microangiopathy seem to pronounce the deficit of bone mass. In these patients, osteopenia is accompanied by a high turnover si…
Relationship of sex hormones to bone geometric properties and mineral density in early pubertal girls.
2004
This study aimed to evaluate the associations among serum 17beta-estradiol (E2), testosterone (T), sex hormone-binding globulin (SHBG), bone geometric properties, and mineral density in 248 healthy girls between the ages of 10 and 13 yr old. The left tibial shaft was measured by peripheral quantitative computed tomography (Stratec XCT-2000; Stratec Medizintechnik, GmbH, Pforzheim, Germany). The cortical bone and marrow cavity areas were expressed as proportions of the total tibial cross-sectional area (CSA). Cortical thickness and total volumetric bone mineral density (vBMD) were also determined. These tibial geometric and densitometric measures were correlated against the serum sex hormone…
The Effectiveness of Physical Exercise on Bone Density in Osteoporotic Patients
2018
Physical exercise is considered an effective means to stimulate bone osteogenesis in osteoporotic patients. The authors reviewed the current literature to define the most appropriate features of exercise for increasing bone density in osteoporotic patients. Two types emerged: (1) weight-bearing aerobic exercises, i.e., walking, stair climbing, jogging, and Tai Chi. Walking alone did not appear to improve bone mass; however it is able to limit its progressive loss. In fact, in order for the weight-bearing exercises to be effective, they must reach the mechanical intensity useful to determine an important ground reaction force. (2) Strength and resistance exercises: these are carried out with…
Relationship between PTH, sex steroid and bone turnover marker measurements and bone density in recently postmenopausal women
2003
Objective: It is conceivable that, since menopause accelerates the continuous bone loss determined by age, a specific configuration of bone mass determinants during the first postmenopausal years occurs. Methods: To establish their value as indicators of bone mass in women with recent natural menopause, we assessed relationships between bone mineral density (BMD) and age, menopausal age, body mass index (BMI), PTH, sex steroid hormones (estradiol and testosterone), and several markers of bone turnover in urine (N-telopeptide and calcium/creatinine ratio) or serum (osteocalcin (OC), total alkaline phosphatase (ALP), total and ionic calcium (iCa), phosphate (P) and magnesium (Mg)) for a group…
Characteristics of patients with mucopolysaccharidosis type II who have received a bone marrow transplant: Data from the Hunter Outcome Survey
2019
Mucopolysaccharidosis type II (MPS II Hunter syndrome) is a rare, life-limiting, X-linked lysosomal storage disease. The Hunter Outcome Survey (HOS) is a Shire-sponsored, global, observational registry initiated in 2005 that collects real-world data on the natural history of MPS II and long-term treatment with enzyme replacement therapy (ERT) with idursulfase. Patients receiving other forms of pharmacological ERT are excluded from HOS but individuals who have received a bone marrow transplant (BMT) may be enrolled. This analysis examined the characteristics of 36 male patients in HOS from Europe and North America who had received a BMT (March 2018 data). In total, 22 patients (61.1%) were E…
Natural History of Mesenteric Venous Thrombosis: A Large Multicentre Study
2008
Abstract Introduction: Mesenteric venous thrombosis (MVT) is an uncommon but potentially life-threatening disease, accounting for 5–15% of mesenteric ischemic events. Most cases of MVT are either identified at laparotomy or at autopsy, with a mortality rate of approximately 50% in old series. Advances in imaging techniques have facilitated the early diagnosis of MVT and, thus, have contributed to a decrease in mortality in the more recent series. The treatment of MVT involves anticoagulation alone or in combination with surgery. Experts suggest that MVT can safely be managed without surgery if there is no evidence of bowel infarction. However, information on the natural history of MVT and o…
Frontal Electroencephalogram Alpha Asymmetry during Mental Stress Related to Workplace Noise
2021
This study aims to investigate the effects of workplace noise on neural activity and alpha asymmetries of the prefrontal cortex (PFC) during mental stress conditions. Workplace noise exposure is a pervasive environmental pollutant and is negatively linked to cognitive effects and selective attention. Generally, the stress theory is assumed to underlie the impact of noise on health. Evidence for the impacts of workplace noise on mental stress is lacking. Fifteen healthy volunteer subjects performed the Montreal imaging stress task in quiet and noisy workplaces while their brain activity was recorded using electroencephalography. The salivary alpha-amylase (sAA) was measured before and immedi…