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101.
We studied the characteristics of headaches in 161 consecutive symptomatic patients with spontaneous dissections of the internal carotid artery (n = 135) or the vertebral artery (n = 26). For patients with internal carotid artery dissection (ICAD), the mean age was 47 years and for those with vertebral artery dissection (VAD), 40.7 years. A history of migraine was present in 18% of the ICAD group and in 23% of the VAD group. Headache was reported by 68% of the patients with ICAD and by 69% of those with VAD, and, when present, it was the initial manifestation in 47% of those with ICAD and in 33% of those with VAD. Ten percent of patients with ICAD had eye, facial, or ear pain without headache. The median interval from onset of headache to development of other neurologic manifestations was 4 days for the ICAD group and 14.5 hours for the VAD group. For all dissections, headaches typically were ipsilateral to the side of dissection. In the ICAD group, headaches were limited to the anterior head in 60% of patients and were steady in 73% and pulsating in 25%. In the VAD group, headaches were distributed posteriorly in 83% of patients and were steady in 56% and pulsating in 44%. Neck pain was present in 26% of patients with ICAD (anterolateral) and in 46% of those with VAD (posterior). The median duration of the headache in patients with VAD and ICAD was 72 hours, but headaches became prolonged, persisting for months to years, in four patients with ICAD.  相似文献   
102.
A two-channel GaAs/AlGaAs asymmetric Mach-Zehnder wavelength demultiplexer with reduced polarization dependence was demonstrated. The device was fabricated on a single heterostructure comprising a 1.45- mu m-thick layer of GaAs on a 6.0- mu m-thick Ga/sub 0.85/Al/sub 0.15/As buffer layer. The epitaxial layers were grown by MOCVD (metalorganic chemical vapor deposition) on an n/sup +/ GaAs substrate. The single-mode rib waveguides, 3 mu m wide and 0.29 mu m high, were fabricated using standard photolithographic techniques followed by chemical etch and removal of the resist mask. Extinction ratios of 24.1 dB for transverse electric (TE) and 22.5 dB for transverse magnetic (TM) polarized light were measured on a device with an anti-reflection coating on its input and output facets. The active length of the device is approximately 6.5 mm and total loss of 1.1 dB was obtained in a 16-mm-long chip.<>  相似文献   
103.
Large lesions of the septal region in the rabbit increased tonic immobility as measured by the number of successful inductions and by duration of immobility. Open field activity was also increased. Septally lesioned rabbits also exhibited increased emotionality, although the topography of the 'septal syndrome' in these rabbits was different from that described for rats. The septally lesioned rabbits exhibited increases in fear reactions such as thumping, escape responses and vocalization when caught, rather than increased aggressiveness. The results are discussed in terms of loss of inhibition of species-typical responses after septal damage.  相似文献   
104.
The possibility of storage of human bone marrow CD34+ cells at 4 degrees C for bone marrow transplantation purposes was investigated. The cells were placed in Iscove medium supplemented with 20% serum (15% bovine calf serum + 5% human AB serum) for three weeks at 4 degrees C. During storage time clonogenicity of granulocytic-monocytic (CFU-GM) erythropoietic (BFU-E) and megakaryocytic (CFU-Meg) progenitors were investigated. It turns out that it is possible to keep human CD34+ cells at 4 degrees C for at least few days before transplantation. At day four of storage the number of CFU-GM and BFU-E cells still exceeded 50% of cells present at day 0. We have found however, CFU-Meg progenitors in comparison to others are much more sensitive to metabolic storage stress. This enhanced sensitivity of megakaryocytic progenitors could explain at least partially the well known ++phenomenon of retardation of thrombopoietic recovery in patients undergoing bone marrow transplantation.  相似文献   
105.
This study examines the intermediate determinants of fertility in Sri Lanka by making use of the data collected in the 1982 Sri Lanka Contraceptive Prevalence Survey and the 1987 Sri Lanka Demographic and Health Survey. The analysis shows that the most important inhibitor of potential fertility is deliberate control. The marital structure of the population is also an important fertility-inhibitor, but lactational infecundability is increasingly becoming an unimportant contributor. The findings show the success of the family planning program in Sri Lanka, which propelled fertility to a substantial lower level. Achievement of the replacement level fertility by the turn of the century, set by the Sri Lankan government, would largely depend on the efforts to increase the quality and quantity of contraceptive use and the duration of breastfeeding.  相似文献   
106.
Adipose tissue leptin mRNA levels are decreased by food deprivation or induction of insulin-deficient diabetes. To determine whether plasma leptin concentrations are similarly affected, whether treatment of diabetes with insulin restores plasma leptin, and whether this requires restoration of body weight (lost as a result of diabetes) and/or normalization of glycemia, we measured plasma leptin concentrations in control, untreated streptozotocin (STZ)-diabetic, and insulin-treated STZ-diabetic rats. Plasma leptin was markedly reduced in untreated STZ-diabetic rats. Insulin treatment for 4 to 17 days increased plasma leptin approximately twofold above control levels. However, despite the hyperleptinemia, insulin-treated diabetic rats gained weight at a rate equal to that of sham-treated controls. Epididymal adipose tissue leptin mRNA levels in 17-day insulin-treated diabetic rats were equal to but did not exceed sham-control levels, unlike plasma leptin. Plasma glucose concentrations in insulin-treated STZ-diabetic rats were lower than in sham controls. Therefore, to determine whether hypoglycemia may be important in increasing plasma leptin, we measured plasma leptin levels in diabetic rats infused with insulin for 3 hours along with a variable-rate glucose infusion targeting glycemia to 200 or 40 mg/100 mL. Plasma leptin rapidly increased in these rats irrespective of target glycemia. Plasma leptin also increased rapidly in normal rats infused with insulin and glucose (target glycemia, 200 mg/100 mL). We conclude that plasma leptin concentrations are markedly reduced under conditions of insulin deficiency and rapidly increased by insulin treatment. The increase in plasma leptin does not require restoration of body weight and, under glucose clamp conditions, does not depend on target glycemia. Hyperleptinemia in insulin-treated diabetic rats is not explained on the basis of steady-state leptin mRNA levels, at least as reflected in epididymal fat.  相似文献   
107.
A combination of Southern blot analysis on a panel of tumor-derived somatic cell hybrids and fluorescence in situ hybridization techniques was used to map YACs, cosmids and DNA markers from the Xp11.2 region relative to the X chromosome breakpoint of the renal cell carcinoma-associated t(X;1)(p11;q21). The position of the breakpoint could be determined as follows: Xcen-OATL2-DXS146-DXS255-SYP-t(X;1)-TFE 3-OATL1-Xpter. Fluorescence in situ hybridization experiments using TFE3-containing YACs and cosmids revealed split signals indicating that the corresponding DNA inserts span the breakpoint region. Subsequent Southern blot analysis showed that a 2.3-kb EcoRI fragment which is present in all TFE3 cosmids identified, hybridizes to aberrant restriction fragments in three independent t(X;1)-positive renal cell carcinoma DNAs. The breakpoints in these tumors are not the same, but map within a region of approximately 6.5 kb. Through preparative gel electrophoresis an (X;1) chimaeric 4.4-kb EcoRI fragment could be isolated which encompasses the breakpoint region present on der(X). Preliminary characterization of this fragment revealed the presence of a 150-bp region with a strong homology to the 5' end of the mouse TFE3 cDNA in the X-chromosome part, and a 48-bp segment in the chromosome 1-derived part identical to the 5' end of a known EST (accession number R93849). These observations suggest that a fusion gene is formed between the two corresponding genes in t(X;1)(p11;q21)-positive papillary renal cell carcinomas.  相似文献   
108.
BCL1/PRAD1 gene rearrangements involving the cyclin D1 gene are a feature of about 70% of centrocytic/mantle-cell lymphomas (CC/MCL) but are identified in only a small proportion of other B-cell non-Hodgkin's lymphomas. Of 37 lymphomas found to have BCL1/cyclin D1 (PRAD1, CCND1) gene rearrangements, 30 fit the morphologic and immunophenotypic criteria for typical CC/MCL. Seven cases with morphologic features atypical for CC/MCL were identified. CD5+ monoclonal B cells were documented in all these cases. Six cases were subsequently stained for cyclin D1 protein, and all showed nuclear positivity. Five cases had variably sized foci of cells with moderately abundant pale cytoplasm resembling parafollicular/monocytoid B cells, marginal zone cells, hairy cells, or even proliferation centers. Transformed-appearing cells were also present in some lymphomas. In one case, striking follicular colonization created a markedly nodular growth pattern mimicking a follicular lymphoma. A sixth case had a marked predominance of small, round lymphocytes at some sites, mimicking a small lymphocytic lymphoma. Five of these six cases also had areas more typical of CC/MCL. The seventh case was a CD5-positive splenic marginal zone-like lymphoma (SMZL) with plasmacytic differentiation and circulating villous lymphocytes consistent with a splenic lymphoma with villous lymphocytes (SLVL). These cases illustrate the morphologic spectrum of small B-cell lymphoid neoplasms that have BCL1/cyclin D1 gene rearrangements and overexpression of cyclin D1. Despite the BCL1 translocation and cyclin D1 overexpression, the splenic lymphoma with plasmacytic differentiation was definitely not a CC/MCL and fit the clinicopathologic entity of SMZL/SLVL. The other six cases are best considered CC/MCL variants based on a combined morphologic, immunophenotypic, and genotypic evaluation. Genotypic or immunophenotypic studies to identify cyclin D1 rearrangements and overexpression, although not pathognomonic, are useful in recognizing these variant CC/MCL cases, which can mimic almost any of the other well-described but more indolent low-grade B-cell lymphomas and leukemias. Some of the variant CC/MCL cases had features in common with the CD5+ cyclin D1+ SMZL/SLVL, suggesting a possible relationship between these two otherwise distinct entities.  相似文献   
109.
110.
Optically pumped lambda =1.3 mu m InGaAsP LEDs have been integrated with glass channel waveguides using epitaxial liftoff. Coupling of light from the grafted LEDs to the waveguides has been achieved with the aid of an overlayer film with tapered ends. Under pulsed operation, devices exhibit a laser-like threshold but without spectral narrowing.<>  相似文献   
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