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991.
In this study, 12 healthy males were exposed to various light conditions (2300K, 3000K, 5000K and dim) for 1.5h at midnight. The conditions of 3000K and 5000K were created by commercial fluorescent lamps. The light at 2300K was achieved by fitting a 3000K fluorescent lamp with a special filter that absorbed short-wavelength light. The vertical illuminance level was kept at 200lx. Saliva samples were taken before and after the light exposure. The light at 5000K suppressed melatonin secretion acutely. The 2300K lamp condition appeared to have no effect on melatonin secretion as well as the dim condition, while melatonin secretion was measurably suppressed by the light at 3000K. 相似文献
992.
Klooster J Kamphuis W Vrensen GF 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2000,131(1):57-63
The olivary pretectal nucleus (OPN) is the first central nucleus in the pupillary light reflex arc (PLR). Substance P (SP) is a neuropeptide present in the OPN. The present immunohistochemical study, performed at the ultrastructural level, aimed to determine the synaptic localization of SP and SP receptor in the OPN. Three types of SP-positive terminals were found. The most abundant type was of retinal origin, characterized by electron-lucent mitochondria and round vesicles, organized in glomerular structures, making asymmetric synaptic contacts with dendrites, and profiles containing pleomorphic vesicles, also making synaptic contacts with dendrites. The second type of SP-immunoreactive terminal contained electron-dense mitochondria and pleomorphic vesicles. This type made symmetric synaptic contacts and may originate from the ventral part of the lateral geniculate nucleus. The third type of SP-immunoreactive terminals contained electron-dense mitochondria, clear round vesicles, and made an asymmetric synaptic contact. This type originates from the contralateral OPN. SP receptors of the NK1 subtype were revealed to be on dendrites and were part of the glomerular-like arrangement. On account of the present observations, it can be concluded that retinal projections to the OPN use SP as a neuromodulator and synapse on NK1 receptor-containing dendrites of large neurons projecting to the Edinger-Westphal nucleus. Since SP also modulates the parasympathetic component of the PLR, we postulate that SP plays a modulating role in all components of the PLR. 相似文献
993.
Primary structure of a variable region of the V kappa I subgroup (ISE) in light chain deposition disease. 总被引:2,自引:0,他引:2 下载免费PDF全文
A Rocca A A Khamlichi P Aucouturier L H Noël L Denoroy J L Preud'homme M Cogn 《Clinical and experimental immunology》1993,91(3):506-509
Although structural abnormalities of monoclonal immunoglobulin light chains (LC) are suspected to play a determinant role in non-amyloid light chain deposition disease (LCDD), this condition is as yet poorly documented at the molecular level, since only three sequences have been reported to date. In a case of myeloma-associated LCDD, the patient's urine contained an unglycosylated kappa Bence Jones protein made up of dimers and monomers with an apparent molecular mass of 25,000 which was assigned to the V kappa I subgroup by N-terminal amino acid sequencing. The complete variable region sequence of the monoclonal kappa chain produced by the malignant plasma cells was amplified by polymerase chain reaction (PCR) using small amounts of material obtained by bone marrow aspiration. The sequence of three independently amplified cDNA clones derived from a normal-sized kappa messenger RNA was identical to that of the urinary kappa chain. The kappa mRNA had an overall normal structure made up of a V kappa I sequence rearranged to J kappa I. Several unusual features of the variable region (the first complete V kappa I sequence reported in LCDD) included three substitutions that introduced hydrophobic residues at spatially close positions. The strategy associating N-terminal sequence determination and cDNA cloning by PCR could help in accumulating new sequence data and improving our understanding of LCDD pathogenesis. 相似文献
994.
The purpose of the present paper was to investigate the heterogeneous nature of amyloid deposits in the liver, by immunohistochemical and immunochemical examination of liver samples from cases of immunoglobulin lambda light chain amyloidosis (Alambda amyloidosis) with antibodies generated against the peptides corresponding to the three different regions of the lambda light chain. Amyloid deposits in the hepatic artery tended to react better with anti-lambda(118-134) than with anti-lambda(159-175). Amyloid deposits in the space of Disse tended to react weakly or partially with anti-lambda(118-134) but well with anti-lambda(159-175). Amyloid deposits in the portal vein reacted relatively well with both antibodies. By western blotting of water-extracted amyloid in which amyloid deposits were not stained with anti-lambda(118-134) immunohistochemically, the three antibodies detected 27 kDa bands consistent with the full-length Ig lambda chain and some smaller bands. These findings indicate that amyloid deposits may not be homogeneous in the liver of AL amyloidosis, and that molecular heterogeneity of amyloid fibril protein or a difference in the mode of deposition results in the histopathological heterogeneity of AL amyloid deposits even within a single patient. 相似文献
995.
SUMMARY Five male subjects were exposed to a single 2-h period of bright (2500 lux) or dim (<100 lux) light prior to sleep on two consecutive nights. The two conditions were repeated the following week in opposite order. Bright light significantly suppressed salivary melatonin and raised rectal temperature 0.3°C (which remained elevated during the first 1.5 h of sleep), without affecting tympanic temperature. Bright light also increased REM latency, NREM period length, EEG spectral power in low frequency, 0.75-8 Hz and sigma, 12–14 Hz (sleep spindle) bandwidths during the first hour of sleep, and power of all frequency bands (0.5–32 Hz) within the first NREMP. Potentiation of EEG slow wave activity (0.5-4.0 Hz) by bright light persisted through the end of the second NREMP. The enhanced low-frequency power and delayed REM sleep after bright light exposure could represent a circadian phase-shift and/or the effect of an elevated rectal temperature, possibly mediated by the suppression of melatonin. 相似文献
996.
BACKGROUND: This study was conducted on human cervical mucus using light microscopy (LM) and scanning electron microscopy (SEM). The objective was the morphological characterization of the different mucus types, with samples taken from the lumen of the cervix and from the different secretory zones of the cervical mucosa. METHODS: A total of 230 samples from 195 women were spread out on slides and air dried. The phenomenon of 'ferning' was observed and assessed in these samples using both LM and SEM. Further samples from the lumen of the cervix and the different secretory crypts were spread out on cover slips and fixed with glutaraldehyde (2.5%) to be studied by SEM. RESULTS: The results show the presence of four different morphological mucus types, namely L, S, P and G, in both types of sample using dried and fixed techniques. CONCLUSIONS: Mucus from the lumen of the cervix appears to be a morphologically heterogeneous entity. It contains different types of secretions, the proportions of which vary throughout the menstrual cycle. The different mucosal types show different types of crystallization, different patterns of ultrastructure (probably related to the arrangement of the glycoprotein network) and are produced in different secretory zones of the crypts in the cervix. 相似文献
997.
目的检测糖尿病患者心功能。方法采用脉冲多普勒彩色超声心动图检测糖尿病、糖尿病合并冠心病患者各33例的心室结构和功能,并与健康组对照。结果糖尿病组的左心室舒张功能较健康组减退,而合并症组较糖尿病组减退更显著。结论糖尿病组的收缩功能与健康组间无统计学意义(P〉0.05),而三组问舒张功能有统计学意义(P〈0.01)。提示心室舒张功能较收缩功能变化更早、更显著。糖尿病组及合并症组左右心室均存在舒张功能障碍,表现为舒张早期心室充盈减低及房缩充盈代偿增强等(E峰流速减慢,A峰流速增快)。糖尿病的心室舒张功能减退与糖尿病的心脏病变和代谢紊乱均有关系,纠正代谢紊乱可避免心功能进一步恶化。 相似文献
998.
One cDNA clone was purified from an adult Clonorchis sinensis cDNA library, and its deduced polypeptide sequence was found to be homologous with myosin regulatory light chain (MRLC) of invertebrates and vertebrates. Two amino-acid residues, Thr and Ser, were conserved at the phosphorylation sites that regulate the function of MRLCs. Recombinant C. sinensis MRLC (rCsMRLC) protein was produced and purified from Escherichia coli, and mouse anti-CsMRLC immune sera recognized a protein of molecular weight 24 kDa from a soluble protein preparation of C. sinensis. The CsMRLC protein was immunohistochemically localized to the muscle fibers of the subtegumental muscle layer and to the muscles of oral and ventral suckers. However, the rCsMRLC protein proved to be less useful antigen for the serodiagnosis of human clonorchiasis.The nucleotide sequence reported herein was submitted to GenBank and assigned accession number AY519356. 相似文献
999.
1000.
Elise Rotureau Christophe Chassenieux Edith Dellacherie Alain Durand 《Macromolecular chemistry and physics.》2005,206(20):2038-2046
Summary: Amphiphilic polysaccharides are obtained by hydrophobic modification of a neutral bacterial polysaccharide, dextran. By reacting the polysaccharide with aliphatic epoxides (epoxyoctane and epoxydodecane) in dimethyl sulfoxide, a series of amphiphilic polymers is obtained which covers a large range of structural parameters (length of the polysaccharide, number and nature of hydrocarbon moieties). The solution behavior of dextran derivatives is first characterized by viscometric measurements in dilute and semi‐dilute domains. The effects of molecular parameters on polymer viscosity behavior are evidenced and discussed. Information on the state of aggregation of polymers is obtained by the use of static and dynamic light scattering. The presence of aggregates in the dilute domain is clearly evidenced and their structural characteristics are estimated (size, molecular weight and number of aggregation). The aggregates are shown to account for the viscometric results in the examined concentration range, relating their chemical parameters (hydrodynamic radius and molecular weight) to the macroscopic behavior of the solutions.