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PubMed1999

Functionally relevant and functionally disruptive (epileptic) synchronized oscillations in brain slices.

Focal seizurelike events can be induced in experimental preparations by means of a number of distinct manipulations that differ in synaptic mechanisms. Nevertheless, the form of the seizurelike events can be explained with common principles, including long-lasting excitation of pyramidal cell dendrites and recurrent excitation between pyramidal cells that provides synchronization. One means of induction of seizurelike events, tetanic stimulation, induces a more physiologic type of activity before seizures are elicited, that is, gamma-frequency (> 20 Hz) oscillations. Such oscillations, called 40-Hz oscillations, are believed to be important for cognition in vivo. Experimental gamma oscillations depend critically on synaptic inhibition between interneurons, from interneurons to pyramidal cells, and on a tonic drive to pyramidal cells and interneurons by metabotropic glutamate receptors. The function of gamma oscillations appears to be imposition of a precise temporal structure on the firing patterns of pyramidal cells while still allowing the pyramidal cells to influence each other and be influenced by afferents selectively. We suggest that a relative loss of synaptic inhibition, occurring by any of a number of mechanisms, prevents the occurrence of gamma activity, allows recurrent pyramidal cell-pyramidal cell excitation to predominate, and thereby allows neuronal networks to generate functionally disruptive seizures.

Animals↗

PubMed1999

[Left ventricular diastolic function evaluated by Doppler echocardiography in coronary artery disease in relation to to systolic function].

The aim of the study was to assess the relationship between left ventricular (LV) diastolic dysfunction measured by Doppler mitral flow indices (D.m.f.i.) and LV systolic performance in coronary artery disease (CAD). 107 pts with confirmed CAD without or after MI in I, II NYHA class was divided into 2 groups according to ejection fraction (EF) value = 55%. 13 D.m.f.i. regarding to the time, velocity, flow volume and derivates were calculated. In the patient with CAD with normal EF, the diastolic dysfunction was characterised by the impaired relaxation. There were prolonged isovolumic relaxation time IVRT and deceleration time of early filling flow DT, reduced early filling fraction EFF and increased the atrial filling fraction AFF, decreased E/A ratio and E/A-VTI. The regression analysis revealed the positive correlation between EF and DT r = 0.35 and inverse correlation between wall motion score index WMSI and DT r = DT r = -0.33. The stepwise regression analysis revealed that EF and WMSI are independent factors influencing on DT. Our results confirm that diastolic dysfunction precedes the systolic dysfunction in CAD. The correlation between D.m.f.i. and LV systolic function parameters were obtained. The results suggest that the LV systolic function should be take to account in the Doppler mitral flow analysis.

Adolescent↗

PubMed2000

Serum cystatin C as an endogenous parameter of the renal function in patients with normal to moderately impaired kidney function.

BACKGROUND: Cystatin C is a proteinase inhibitor with a low molecular weight. The serum levels of cystatin C are mainly dependent on glomerular filtration rate (GFR) making cystatin C an endogenous parameter of GFR. The aim of the study was to elucidate the applicability of serum cystatin C as a parameter of GFR in patients with normal to moderately impaired kidney function and to estimate a reference interval for serum cystatin C. PATIENTS AND METHODS: Forty-six patients (25 males and 21 females) aged 22 to 83 years with various kidney diseases and 250 blood donors (164 males and 86 females) aged 19 to 64 years were included. Cystatin C was measured by an automated particle-enhanced nephelometric immunoassay, serum creatinine by an enzymatic and by Jaffé method, urine creatinine by an enzymatic method, and GFR by 99mTc-DTPA clearance. RESULTS: Serum levels ofcystatin C and creatinine showed increments with decreasing values of 99mTc-DTPA clearance and a linear relationship was found between 99mTc-DTPA clearance and l/serum cystatin C, l/serum creatinine (enzymatic method), and creatinine clearance. Comparison of the non-parametric receiver-operating characteristic (ROC) plots for serum cystatin C (area under the curve (AUC) = 0.996; SE = 0.005), serum creatinine (enzymatic method) (AUC = 0.899; SE = 0.044), serum creatinine (Jaffé method) (AUC = 0.870; SE = 0.051), measured creatinine clearance (AUC = 0.959; SE = 0.025), and estimated creatinine clearance (0.950; SE = 0.029) revealed significant differences for serum cystatin C and serum creatinine (enzymatic and Jaffé method) (p values: 0.03 and 0.01). No significant differences were demonstrated between serum cystatin C and measured and estimated creatinine clearance (p value: 0.14 and 0.12). The non-parametric reference interval for serum cystatin C was calculated to be 0.51-1.02 mg/l (median: 0.79 mg/l; range: 0.33 - 1.07 mg/l). CONCLUSION: Serum cystatin C seems to be a better parameter of GFR than serum creatinine in adults with various types of kidney disease with normal to moderately impaired kidney function.

Adult↗

PubMed2001

Inhibition of heat shock protein 90 function by ansamycins causes the morphological and functional differentiation of breast cancer cells.

17-(Allylamino)-17-demethoxygeldanamycin (17-AAG) is an ansamycin antibiotic that binds to a conserved pocket in Hsp90 and induces the degradation of proteins that require this chaperone for conformational maturation. 17-AAG causes a retinoblastoma (RB)-dependent G1 block in cancer cells and is now in clinical trial. In breast cancer cells, G1 block is accompanied by differentiation and followed by apoptosis. The differentiation is characterized by specific changes in morphology and induction of milk fat proteins and lipid droplets. In cells lacking RB, neither G1 arrest nor differentiation occurs; instead, they undergo apoptosis in mitosis. Introduction of RB into these cells restores the differentiation response to 17-AAG. Inhibitors of the ras, mitogen-activated protein kinase, and phosphatidylinositol 3-kinase pathways cause accumulation of milk fat proteins and induction of lipid droplets when associated with G1 arrest but do not cause morphological changes. Thus, regulation of Hsp90 function by 17-AAG in breast cancer cells induces RB-dependent morphological and functional mammary differentiation. G1 arrest is sufficient for some but not all aspects of the phenotype. Induction of differentiation may be responsible for some of the antitumor effects of this drug.

Antibiotics, Antineoplastic↗

PubMed2001

Erythroid marrow activity and functional anemia in patients with the rare interaction of a single functional a-globin and beta-globin gene.

BACKGROUND AND OBJECTIVES: The degree of globin chain imbalance and tissue hypoxia are important determinants of clinical severity in thalassemia syndromes. Thus phenotypic expression may be modified by interaction of alpha- and beta-thalassemia defects, level and type of hemoglobin synthesized and oxygen release to the tissues. We evaluated hematology, erythroid marrow activity and functional anemia in patients with the rare interaction of a single a-globin gene and heterozygous beta-thalassemia (HbH/beta-thal trait). DESIGN AND METHODS: In 7 patients characterized by DNA analysis to have HbH disease genotypes with beta-thalassemia trait, we assessed hematologic findings, serum transferrin receptor (sTfR), serum erythropoietin (Epo), red cell 2,3-disphosphoglycerate (2,3-DPG) and whole blood oxygen releasing capability. RESULTS: Patients with HbH/beta-thal trait had moderate anemia, marked hypochromasia and microcytosis, normal or raised HbA2, and no electrophoretically/chromatographically detectable HbH. Epo and sTfR levels were significantly higher than in beta-thalassemia heterozygotes, but lower than in patients with HbH disease; 2,3-DPG levels were highest in HbH/beta-thal trait. Oxygen binding studies and simulations showed reduced oxygen affinity (P50) in HbH/beta-thal trait, resulting in increased oxygen release (O2R). INTERPRETATION AND CONCLUSIONS: Hematologic findings and bone marrow activity in patients with HbH/b-thal trait were consistent with the modified globin chain imbalance and hemoglobin synthesis expected from interaction of HbH disease with heterozygous b-thalassemia, although this rare complex genotype may elude diagnosis based on hematology alone. Significantly higher red cell 2,3-DPG levels were an unexpected finding, and the consequent increase in oxygen release capability resulted in a compensated functional anemia relative to hemoglobin levels.

Adolescent↗

PubMed2002

Quantitative functional MR imaging of the visual cortex at 1.5 T as a function of luminance contrast in healthy volunteers and patients with multiple sclerosis.

BACKGROUND AND PURPOSE: In patients with multiple sclerosis (MS), a few preliminary functional MR (fMR) imaging studies of the visual cortex reveal information about magnitude differences between healthy individuals and patients with MS at only a single luminance level. We therefore investigated whether varying luminance contrast levels can help uncover subtle changes in fMR imaging characteristics of the visual cortex in healthy volunteers and patients with MS. METHODS: Blood oxygenation level-dependent fMR imaging signal changes in the primary visual cortex were examined as a function of luminance contrast at 1.5 T in 10 healthy volunteers and nine patients with MS. Ten axial sections through the calcarine fissure were obtained with an echo-planar T2*-weighted imaging sequence (4000/54/1 [TR/TE/excitation]; field of view, 220 mm; voxel size, 1.72 x 1.72 x 5 mm). The imaging series consisted of an alternating 20-second rest epoch (black screen) with a 20-second activation epoch (flickering checkerboard) repeated six times. Each imaging series used a graded increase of eight luminance contrast levels. A paired t test between rest and activation images was used to analyze significant (P <.001) contiguous voxels in the region of interest (primary visual cortex). RESULTS: A progressive increase in fMR imaging activation across all luminance contrast levels in healthy controls and patients with MS was shown. The patients with MS had a significantly lower magnitude in the number of fMR imaging activated voxels at all luminance contrast levels (P <.001). A statistically significant increase in fMR imaging activation (activation threshold) was seen at the second luminance contrast level in controls and at the seventh level in patients with MS. CONCLUSION: Quantifiable changes in blood oxygenation level-dependent signal and a progressive increase in activated voxels within the primary visual cortex with increasing luminance contrast were demonstrated at 1.5 T in controls. The patients with MS showed a significant decrease in the number of activated voxels and an increase in activation threshold compared with healthy controls.

Adult↗

PubMed2002

[Functional state of the central nervous system in people with varying functional agility of the nervous processes while transforming information of varying complexity].

Relations between functional agility of the nervous processes (FANP) and functional state (FS) of the central nervous system at performing simple and difficult sensomotor tasks have been studied. It has been shown that FANP is of the exceptional importance in forming FS of the central nervous system only to perform difficult mental tasks.

Adolescent↗

PubMed2002

[The assessment of structure-function interrelationship from the standpoint of functional systems].

One of the major methodological problems of morphology--the correlation of "structure" and "function" categories in normal anatomy and histology--is discussed. The issues of mobility of concepts concerning organization of functional systems, differon tissue organization, tissue classification including the special place of extraembryonic organs, are examined. The organizational matters associated with the introduction of a new speciality 03.00.25--histology, cytology, cell biology--and with the necessity of revision of the program of qualifying examination in philosophy for the candidate's degree in the field of histology, are discussed.

Histology↗

PubMed2002

[Problems of the existence of "optimal" function survival functions in experiments of varying protein supplies to Mediterranean fruit flies].

The paper is devoted to the discussion of the possibility of analyzing the changes in survival curves of Mediterranean Fruit Flies under different levels of reproduction by means of solving the optimization problem with some objective function. The investigation is carried out on the base of mathematical model with approximations resulting in the analysis of joint changes in survival functions and reproduction in flies subjected to different conditions of protein availability in food. The model describes possible mechanisms of evolutionary selection from the point of view of trade-off in average life span and reproduction.

Animals↗

PubMed2003

[A follow-up study on mental and physical function function among stroke patients: comparisons between admission and discharge status in a rehabilitation-specialized hospital].

PURPOSE: To assess results of a 5 year-follow-up, in terms of disability, depression, quality of life, and social network in cases of stroke patients. This report deal with results at admission and discharge (in average, from 2.5 to 6 months of the onset) in a rehabilitation-specialzed hospital. OBJECT AND METHOD: The subjects were 87 stroke patients hospitalized in the Ibaraki Prefectural University Hospital. They were 64 men and 23 women, and their age were between 42 and 79 with an average of 59 years. Systematic evaluation for mental and physical functions was conducted at admission and discharge, and it is intended that the evaluation will be repeated 1, 2, 3 and 5 years from the stroke onset. RESULTS: There were substantial improvements in motor functions, general intelligence, and the status of dementia during the hospitalization. Activities of daily living and degrees of job execution and satisfactory were also improved. The prevalence of depression remained 40%, and the acceptance of limb paralysis or reduced quality of life did not change. Social network scores declined. DISCUSSION: Lack of improvement of depressive status and quality of life, and deterioration social network may increase the rist of major difficulties after discharge of stoke patients. Prevention programs at hospital may be necessary to cope with these potential problems.

Activities of Daily Living↗

PubMedDate not supplied

[Functional neuroanatomy. Cortical mapping in usual paradigm in functional magnetic resonance imaging].

Using cases of their own experience, the authors describe the cortical mapping related with the main brain functions they had investigated by Functional Magnetic Resonance Imaging (fMRI).

Cerebral Cortex↗

PubMed1992

[Variations in the functionality of cardiac adenyl cyclase as a function of age].

The metabolic and functional activity of the heart closely depends on cAMP and therefore on the integrity of adenylate cyclase (AC) system. Alterations of this signal transduction system might be co-responsible for the impairment of cardiac performance observed with aging. Evidence is here provided that basal activity of cardiac membrane-bound (48,000 x g) AC significantly declines with the age of the rat (1, 12, 24 month-old). This is accompanied with the decrease of cAMP content, which leads to the fall of cAMP/cGMP molar ratio a possible final determinant of cardiac performance. Kinetic analyses indicate that aging is associated with a net increase of the Km of a cardiac AC, while the Vmax is unaffected. Besides, the response in vitro of AC from 24-month-old heart to the inhibitor spermine or a different stimulants, such as Gpp (NH) p, isoproterenol, PGE1 or forskolin, is significantly lower than that of AC from 1 month-old one. The suggestion is made that aging causes an impairment in the capability of the catalytic moiety of cardiac AC to make functional complexes with activated guanine nucleotide binding proteins.

Adenylyl Cyclases↗

PubMed1992

Improved diastolic function with the calcium antagonist nisoldipine (coat-core) in patients post myocardial infarction: results of the DEFIANT study. Doppler Flow and Echocardiography in Functional cardiac Insufficiency: Assessment of Nisoldipine Therapy.

A multicentre, randomized, double-blind, placebo-controlled, parallel-group trial was undertaken in 135 patients to determine whether 4 weeks of treatment with long-acting nisoldipine coat-core (20 mg once a day) could alter diastolic function in patients with a recent myocardial infarction and with mild left ventricular dysfunction as indicated by a left ventricular ejection fraction < or = 50%. The primary endpoint was the change in diastolic filling parameters assessed by Doppler and two-dimensional echocardiography. The mean time of admission to the study was 20 days (range 7-35) after myocardial infarction. Mean left ventricular ejection fraction was 41%. The drug increased early diastolic peak velocity at the tips of the mitral leaflet by 0.06 m.s-1 (95% confidence intervals (CI): 0.01, 0.11). The time velocity integral was increased by 1.2 cm (95% CI: 0.16, 2.27). These findings are indicative of increased early diastolic flow across the mitral valve. An important determinant appeared to be a reduced isovolumic relaxation time (by 14.7 ms, 95% CI: -22.5, -6.9). As there was no change in heart rate, systolic and diastolic blood pressure or cardiac output, afterload reduction appeared unlikely as an explanation. Peak workload on exercise was 12 watts higher in the group on nisoldipine (95% CI: 0.8, 23.3). Thus, nisoldipine was shown to improve indices of diastolic ventricular function, as well as exercise capacity, in this group of patients. The observed effects of nisoldipine may reflect an anti-ischaemic effect or be due to improved relaxation of the myocardium.

Delayed-Action Preparations↗

PubMed2003

[Dynamics of clinical symptoms, indices of quality of life, and the state of motor function of the esophagus and rectum in patients with functional dyspepsia and irritable bowel syndrome after Helicobacter pylori eradication].

94 patients with irritable bowel syndrome and functional dyspepsia were included in the study. To confirm the diagnosis of H. pylori infection, all patients underwent fibroesophagogastroduodenoscopy with histological and urea tests before and 5 weeks after treatment. Standard eradication was performed. 25 patients underwent intraesophageal and anorectal manometry using the Polygraf device, Sweden. The dynamics of clinical symptoms, life quality (SF-36), manometry data and data of the histological examination of the stomach mucous coat was assessed. 63.5% of patients had clinical improvements following the eradication. The threshold of rectal sensitivity rose in 40% of patients. The esophageal motor function normalized in 48% of patients. An improvement of the morphological picture of chronic gastritis was recorded in 58.7% of patients.

Adult↗

PubMed1992

Functional electrical stimulation (FES) systems for restoration of motor function of paralyzed muscles--versatile systems and a portable system.

Multichannel functional electrical stimulation (FES) systems were developed to restore the motor functions of the paralyzed muscles, i.e. two kinds of versatile systems for laboratory use and a practical portable system were developed. The first microcomputer-based FES system was composed of an 8 bit microcomputer (PC-8801mkII) with a voice recognition board and 30 stimulation outputs, in which the voice commands were used for selecting a motion pattern, and for executing (start), (hold), (restart) and (stop) commands. In combination with the voice commands, a proportional control command detected from a head angle sensor was used for volitional control of motion. The second microcomputer-based FES system was composed of a 16 bit microcomputer (PC-9801 UV or compatible) with flexible control capabilities (e.g. respiratory sensors) for volitional control and with 64 stimulation outputs. An originally designed practical portable FES system was 89 x 145 x 31 mm in dimension and 380 g in weight. This paper describes the system configurations, the control methods of these FES systems and three examples of the clinical applications of the FES systems.

Electric Stimulation Therapy↗

PubMed2005

Hypertension and cognitive function. Blood pressure regulation and cognitive function: a review of the literature.

High blood pressure raises the risks of vascular dementia and cognitive dysfunction in older adults, by acting on the cerebral vasculature and directly on the brain itself. Clinical trials and observational studies have shown that treating hypertension to target (<140/90 mm Hg) not only lessens morbidity and mortality, but also improves quality of life and preserves cognitive function. Yet, only 34% of hypertensive Americans currently have their hypertension under control, despite widespread treatment. Although single drug therapy is effective in treating hypertension, most patients will require combination drug treatment. Combination therapy--typically a diuretic with an ACE inhibitor, an ARB, or a beta blocker--is appropriate for treatment of older patients, is well tolerated, and can effectively preserve cognitive function.

Aged↗

PubMed2004

Factors influencing pain, physical function and social functioning in patients with osteoarthritis in southern Italy.

The aim of this study was to assess factors influencing bodily pain (BP), physical function (PF) and social functioning (SF) in patients with osteoarthritis (OA) from southern Italy A total of 1,782 patients (mean age 66.08 years, 570 men and 1,212 women) with knee, hip, spine or hand OA underwent a structured assessment comprising demographic data and the Short Form 36 (SF-36) BP, PF and SF scales. Separate multiple linear regression models were employed for statistical analysis. The mean disease duration was 9.18 years and the mean body mass index (BMI) was 27.06. The mean BP, PF and SF scores of 34.93 (SD 19.37), 63.58 (SD 26.53) and 47.89 (SD 21.83) for the study subjects were substantially lower than those expected for the general Italian population. Subjects who were younger with a shorter disease duration and lower BMI had better PF and SF Younger subjects with a lower BMI and a longer disease duration had less BP. Female sex was associated with more BP, worse SF and better PF. In conclusion, demographic and disease-related factors influence BP, PF and SF in southern Italian patients with OA.

Age Factors↗

PubMed2005

[Study of the motor function of the function and duodenum at diseases of the biliary excretion system].

For the last few years the disorders of the motor function of the gastrointestinal tract are subjects of interest for investigators and physicians. The article presents an analysis of different abnormalities of the motor function of the stomach and duodenum made by gastroduodenoscintigraphy in patients with the biliary tract disorders. The most frequent types of motor gastric and duodenal dysfunctions are discussed in patients with gall bladder dysfunction, chronic cholescystitis, and patients after cholecystectomy.

Biliary Tract↗