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A model of instrumental defensive reflexes associated with the maintenance of a specific posture was used in chronic experiments with four dogs to demonstrate the preferential inhibitory influence of preliminary low-frequency stimulation (2 impulses/sec) of the head of the caudate nucleus in the right and left hemispheres on the electromyographic and mechanographic components of the instrumental defensive reflex effecting the reflex motor program. Subjected to the greatest changes were the postural, components of the electromyogram, which permits the postulate as to the importance of the caudate head in the organization of posture. It was shown that the caudate head is bilaterally involved in the prerelease processes preceeding the instrumental response. At the same time, the difficulty of inhibiting the performance of the actual instrumental task- the avoidance of an electric current- was noted during stimulation of the caudate head in a system of instrumental defensive reflexes.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 68, No. 11, pp. 1488–1499, November, 1982.  相似文献   
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A number of noninvasive fiber optic optical technologies are under development for real-time diagnosis of neoplasia. We investigate how the light scattering properties of cervical cells are affected by changes in nuclear morphology, DNA content, and chromatin texture, which occur during neoplastic progression. We used a Cyto-Savant computer-assisted image analysis system to acquire quantitative nuclear features measurements from 122 Feulgen-thionin-stained histopathologic sections of cervical tissue. A subset of the measured nuclear features was incorporated into a finite-difference time-domain (FDTD) model of cellular light scattering. The magnitude and angular distribution of scattered light was calculated for cervical cells as a function of pathologic grade. The nuclear atypia strongly affected light scattering properties. The increased size and elevated DNA content of nuclei in high-grade lesions caused the most significant changes in scattering intensity. The spatial dimensions of chromatin texture features and the amplitude of refractive index fluctuations within the nucleus impacted both the angular distribution of scattering angles and the total amount of scattered light. Cellular scattering is sensitive to changes in nuclear morphology that accompany neoplastic progression. Understanding the quantitative relationships between nuclear features and scattering properties will aid in the development of noninvasive optical technologies for detection of precancerous conditions.  相似文献   
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Prolonged clinico-immunological observation of 85 patients with definite multiple sclerosis (MS) was performed in order to elucidate the connections between the clinical and immune state. A battery of immunological investigations was performed, including estimation of T-cell subpopulations in blood and cerebrospinal fluid (CSF); proliferative responses of circulating lymphocytes to mitogens, recombinant interleukin-2 (rIL2) and myelin basic protein levels in different culture conditions; levels of immunoglobulin (Ig) in sera and CSF, and of Ig production in vitro; indices of IL2 synthesis and IL2 sensitivity; production of prostaglandin E2 and tumour necrosis factor (TNF) alpha by monocytes and levels of -endorphin in sera and supernatants phytohaemagglutinin of (PHA)-activated cells. Clinical observation was performed periodically using Kurtzke scales and was supplemented by repeated recording of evoked potentials and magnetic resonance imaging. Initial investigations showed specific differences between patients with MS and the control groups (donors and patients with other neurological disorders of the same age). Correlative and regressive analyses showed no association between immunological and clinical parameters at the initial investigation, although immunological indexes were inter-related, and indicated specific alterations in immuno-regulation in MS. Retrospective analysis revealed associations between the clinical status of patients with MS and their previous immune status. Evidence of cell activation — including a decreased percentage of circulating cells with differential antigens, lower cell mitogen-induced proliferative responses in vitro, with restoration following the addition of autoserum, greater IL2 sensitivity, and increased TNF-alpha production by macrophages — often predicted the clinical manifestation of deterioration. It is proposed that the immunopathological process in MS has a number of stages with characteristic features, and that progression from one stage to another can be subclinical. No single immunological index can be used to determine stage. Only systemic alterations reflect the real situation, whilst every patient has some abnormalities. A system of clinico-immunological monitoring could severe as the basis for a new approach to the dynamic treatment of MS.  相似文献   
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Higher fat and energy intakes confer a survival advantage in cystic fibrosis (CF). There is a need to develop effective nutrition programmes that ensure optimal energy intake in CF.

Methodology:


A cross-sectional measurement of clinical characteristics and energy and fat intakes in patients attending the CF outpatients clinic of the John Hunter Hospital, Newcastle was undertaken. Twenty-nine subjects, mean age 12 years (range 4.3–20.2), completed weighed food records to determine the contribution of fat to the percentage of the recommended energy intake obtained and to document use of pancreatic enzyme replacement therapy.

Results:


Diets with a high percentage of energy derived from fat did not guarantee that individuals with CF met their energy requirements. Subjects with total fat intakes of 100 g per day or greater, however, achieved in excess of 110% recommended daily intake (RDI) for energy. Up to 47% of subjects consumed more pancreatic enzyme replacement capsules than shown to give maximum effectiveness.

Conclusion:


Setting a 100 g daily fat target is a realistic way of ensuring high energy intakes in CF. Fat ready reckoners would identify the fat content of food and prescribe specific numbers of pancreatic enzyme replacement capsules to be consumed with each meal or food item.  相似文献   
8.
In the current work, YAGG:Cr3+ nanophosphors were synthesized by the Pechini method and then annealed at different temperatures in the range 800–1300 °C. The structure and morphology of the samples were characterized by X-ray Powder Diffraction (XRPD). The lattice parameters and average crystalline sizes as site occupation by Al3+ and Ga3+ ions were calculated from the Rietveld refinement data. To investigate the effect of crystalline size of the materials on their optical properties: excitation and emission spectra were recorded and analyzed. Finally, the effect of crystalline size on the probability of carrier recombination leading to PersL was determined experimentally with thermoluminescence analyses. The Tmax-Tstop method was applied to determine the trap type and particle size (calcination temperature) effect on their redistribution. A correlation between structural changes and trap redistribution was found. In particular, the extinction of high-temperature TL maximum with increasing annealing temperatures is observed, while low-temperature TL maximum increases and reaches a maximum when the lattice parameter reaches saturation.  相似文献   
9.
Results from a comparative study investigating 38 donor insemination (DI) Dutch families with 4-8 year old children are presented. The aims of this study were to investigate parents' opinions on the issues of confidentiality and donor anonymity, to assess the emotional development of the children, and to examine in DI families the association between secrecy with regard to the use of a donor and the emotional adjustment of the children. The DI families were compared to families with a child conceived by in-vitro fertilization (IVF) and to families with a naturally conceived child. Secrecy appeared to be associated with DI and not with IVF: 74% of the DI parents intended not to inform the child about the way in which she/he was conceived, whereas none of the IVF parents intended to keep the secret. Only one set of DI parents and two sets of IVF parents had actually told the child. As to donor anonymity, a spread of opinions appeared among DI parents; 57% preferred an anonymous donor, 31% would have liked non- identifying information about the donor, 9% preferred the donor's identity to be registered and 3% remained unsure. Parents' major concern was to know more about the medical/genetic background of the donor. Mothers and fathers in the DI families differed in their opinions concerning the issues of confidentiality and donor anonymity: fathers, more often than mothers, were secretive with regard to the use of a donor and husbands, more often than their wives, were in favour of donor anonymity. With regard to the emotional development of the children, more emotional/behavioural problems were revealed among DI children than among children who were naturally conceived. No association was found between secrecy and the emotional/behavioural adjustment of the children.   相似文献   
10.
A large part of Central Serbia experiences continual shortage of sufficient ground water resources. For that reason, more than 20 reservoirs serve as drinking water suppliers. Significant and persistent cyanobacterial “blooms” have been recognized in nine of them. Samples for cyanotoxin analyses were taken during and after “blooms” in ?elije Reservoir and from Kru?evac town-supplied tap water from that reservoir two days later. Concentration of microcystin-LR was 650 μ gL–1 in the reservoir, while the tap water contained 2.5 μ gL–1.

In the two investigated periods, the high primary liver cancer (PLC) mortality of 11.6 from 1980–1990 and extremely high PLC incidence of 34.7 from 2000–2002 were observed in the regions affected by heavy cyanobacterial “blooms.” In contrast, PLC mortality and incidence rates were substantially lower in the regions not affected by cyanobacterial blooms: in 1980–1990 the rate of PLC mortality amounted to 2.7 in Kosovo, 7.6 in Vojvodina, and 8.3 in the non-affected regions of Central Serbia; while in 2000–2002 PLC incidence amounted to 4.1 in Kosovo, 5.2 in Vojvodina, and 13.6 in the non- or less-affected regions of Central Serbia. Keeping in mind that the most affected PLC regions in Central Serbia (Topli?ki, Ni?ki, and ?umadijski regions) have the water supply systems based on six reservoirs found regularly in bloom during summer months and that some of the regions are also connected with two boundary “blooming” reservoirs, representing a total of eight of nine blooming reservoirs, it is easy to presume that the PLC incidence could be related to drinking water quality.

The uneven geographic distribution of liver cancer in Serbia is conspicuous and hot spots could be related to drinking water supply. It is very clear that the high-risk regions for PLC occurrence correspond with drinking water reservoirs continually found with cyanobacterial blooms, and the low risk regions correspond with water supplies not affected by cyanobacteria.  相似文献   
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