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991.
Progressive X-linked cone-rod dystrophy (COD1) is a retinal disease affecting primarily the cone photoreceptors. The COD1 locus originally was localized, by the study of three independent families, to a region between Xp11.3 and Xp21.1, encompassing the retinitis pigmentosa (RP) 3 locus. We have refined the COD1 locus to a limited region of Xp11.4, using two families reported elsewhere and a new extended family. Genotype analysis was performed by use of eight microsatellite markers (tel-M6CA, DXS1068, DXS1058, DXS993, DXS228, DXS1201, DXS1003, and DXS1055-cent), spanning a distance of 20 cM. Nine-point linkage analysis, by use of the VITESSE program for X-linked disorders, established a maximum LOD score (17.5) between markers DXS1058 and DXS993, spanning 4.0 cM. Two additional markers, DXS977 and DXS556, which map between DXS1058 and DXS993, were used to further narrow the critical region. The RP3 gene, RPGR, was excluded on the basis of two obligate recombinants, observed in two independent families. In a third family, linkage analysis did not exclude the RPGR locus. The entire coding region of the RPGR gene from two affected males from family 2 was sequenced and was found to be normal. Haplotype analysis of two family branches, containing three obligate recombinants, two affected and one unaffected, defined the COD1 locus as distal to DXS993 and proximal to DXS556, a distance of approximately 1.0 Mb. This study excludes COD1 as an allelic variant of RP3 and establishes a novel locus that is sufficiently defined for positional cloning.  相似文献   
992.
Incubation of heat-denatured plasma from the rainbow trout Oncorhynchus mykiss with porcine pancreatic kallikrein generates, in addition to bradykinin-related peptides, previously uncharacterized peptides that contract mammalian and amphibian vascular smooth muscle. Using rings of vascular smooth muscle from the bullfrog systemic arch as bioassay, we have isolated two myotropic peptides whose primary structures were established as: Asn-Arg-Val-Tyr-Val-His-Pro-Phe ([Asn1, Val5]angiotensin II) and Asp-Arg-Val-Tyr-Val-His-Pro-Phe ([Asp1, Val5]angiotensin II). These peptides are the same as those generated in salmon plasma by an extract of kidney. The data raise the possibility that activation of the kallikrein-kinin system in trout generates both bradykinin-related and angiotensin II-related peptides that may act synergistically in the regulation of blood pressure.  相似文献   
993.
994.
OBJECTIVE: The objective of this study was to examine the effect of family and neighborhood income on health care use of young children born prematurely and of low birth weight (N = 619). DESIGN: A birth cohort was enrolled in a clinical randomized trial of early childhood educational and family services. SETTINGS/PARTICIPANTS: Infant Health and Development Program provided a sample of low birth weight premature infants stratified by clinical site, birth weight, and treatment group. Maternal reports of health care use, family income, and heath insurance were obtained at 12, 24, and 36 months of corrected age. Neighborhood income was based on census tract residence at birth. MAIN OUTCOME MEASURES: Maternal reports of hospitalizations, doctor visits, and emergency department visits were used; data were averaged over the child's first 3 years of life. RESULTS: Children from poorer families were more likely to be hospitalized and to have more emergency department visits than were children from more affluent families. Residence in poor and middle-income neighborhoods was associated with more emergency department visits than residence in affluent neighborhoods. Families in middle-income neighborhoods reported more doctor visits than families in poor or affluent neighborhoods. CONCLUSION: Neighborhood residence influences health care use by poor and nonpoor families and by insured and uninsured families. The use of the emergency department for low birth weight premature children in middle-income and poor neighborhoods is discussed.  相似文献   
995.
As part of a drug discovery program to discover more effective platinum-based anticancer drugs, a series of platinum complexes of trans coordination geometry centered on trans-ammine(cyclohexylaminedichlorodihydroxo)platinum(IV) (JM335) has been evaluated in vitro against a panel of cisplatin-sensitive and cisplatin-resistant human tumor cell lines (predominantly ovarian). In vitro, against 5 human ovarian carcinoma cell lines, JM335 was comparably cytotoxic to cisplatin itself and over 50-fold more potent than transplatin (mean 50% inhibitory concentrations: JM335, 3.1 microM; cisplatin, 4.1 microM; transplatin, 162 microM). With the use of seven pairs of human tumor cell lines (parent and subline with acquired resistance to cisplatin and encompassing all of the known major mechanisms of resistance to cisplatin) JM335 exhibited a different cross-resistance pattern to that of its cis isomer (JM149). JM335 showed non-cross-resistance in six of the seven resistant lines, cross-resistance in the A2780cisR line possibly being associated with high levels of glutathione. Preliminary intracellular DNA binding studies showed that in contrast to transplatin, JM335 was efficient at forming DNA-DNA interstrand cross-links. In vivo, JM335 produced growth delays in excess of 15 days against 4 of 6 human ovarian carcinoma xenografts and was unique among the complexes studied in retaining some efficacy against a cisplatin-resistant subline of the murine ADJ/PC6 plasmacytoma. JM335 is the first trans-platinum complex to demonstrate marked antitumor efficacy against both murine and human s.c. tumor models and represents a significant structural lead to complexes capable of circumventing cross-resistance to cisplatin.  相似文献   
996.
Serial serum prostate-specific antigen (PSA) levels were analyzed retrospectively for prognostic implications in 70 patients with locoregional (Stages B2, C, and D1) prostate cancer who were managed with high energy neutron beam therapy. Three groups of patients were identified. Group I included 30 patients whose serum PSA level decreased to the reference range (0-4 ng/mL) following neutron therapy and remained so subsequently: 28 (93%) remained disease-free and 2 (7%) have failed distantly. All 30 patients (100%) had no evidence of locally progressive disease. This group was categorized as having a good prognosis. The mean time for serum PSA value to decline to reference range was six months; calculated mean time to achieve a stable base-line PSA was 53 +/- 37 days. Follow-up period ranged from twelve to fifty-six months (median: 21 months). Group II consisted of 13 patients in whom there was an initial decrease in serum PSA to reference range followed by a subsequent increase: 6 of 13 (46%) have no overt clinical progression of disease; 7 (54%) have either persistent locoregional or distant metastatic disease. Follow-up period was from twelve to seventy-two months (median: 39 months). Calculated mean time to achieve stable baseline PSA for serum PSA in this group was 61 +/- 21 days. Group III patients had a persistently elevated or rising serum PSA concentration. Of 27 patients in this group, only 9 (33%) have no evidence of disease progression, while 18 patients (67%) have failed already, either locoregionally or distantly. Follow-up period ranged from twelve to sixty-nine months (median: 21 months). Mean time to achieve stable baseline of serum PSA in this cohort of patients with a poor prognosis was 108 +/- 76 days. We conclude that PSA has a predictable prognostic value in patients with locally advanced prostate cancer managed with high energy neutron beam therapy. Rapid normalization of PSA after therapy indicates a good prognosis. Persistent elevation signifies either presence of persistent locoregional disease or development of distant metastases. Subsequent elevation of the serum PSA concentration after definitive therapy signals progression of prostate cancer.  相似文献   
997.
Thrombin binds to fibrin at two classes of non-substrate sites, one of high affinity and the other of low affinity. We investigated the location of these thrombin binding sites by assessing the binding of thrombin to fibrin lacking or containing gamma' chains, which are fibrinogen gamma chain variants that contain a highly anionic carboxyl-terminal sequence. We found the high affinity thrombin binding site to be located exclusively in D domains on gamma' chains (Ka, 4.9 x 10(6) M-1; n, 1.05 per gamma' chain), whereas the low affinity thrombin binding site was in the fibrin E domain (Ka, 0.29 x 10(6) M-1; n, 1.69 per molecule). The amino-terminal beta15-42 fibrin sequence is an important constituent of low affinity binding, since thrombin binding at this site is greatly diminished in fibrin molecules lacking this sequence. The tyrosine-sulfated, thrombin exosite-binding hirudin peptide, S-Hir53-64 (hirugen), inhibited both low and high affinity thrombin binding to fibrin (IC50 1.4 and 3.0 microM respectively). The presence of the high affinity gamma' chain site on fibrinogen molecules did not inhibit fibrinogen conversion to fibrin as assessed by thrombin time measurements, and thrombin exosite binding to fibrin at either site did not inhibit its catalytic activity toward a small thrombin substrate, S-2238. We infer from these findings that there are two low affinity non-substrate thrombin binding sites, one in each half of the dimeric fibrin E domain, and that they may represent a residual aspect of thrombin binding and cleavage of its substrate fibrinogen. The high affinity thrombin binding site on gamma' chains is a constitutive feature of fibrin as well as fibrinogen.  相似文献   
998.
The novel sodium channel PN3/alpha-SNS, which was cloned from a rat dorsal root ganglion (DRG) cDNA library, is expressed predominantly in small sensory neurons and may contribute to the tetrodotoxin-resistant (TTXR) sodium current that is believed to be associated with central sensitization in chronic neuropathic pain states. To assess further the role of PN3, we have used electrophysiological, in situ hybridization and immunohistochemical methods to monitor changes in TTXR sodium current and the distribution of PN3 in normal and peripheral nerve-injured rats. (1) Whole-cell patch-clamp recordings showed that there were no significant changes in the TTXR and TTX-sensitive sodium current densities of small DRG neurons after chronic constriction injury (CCI) of the sciatic nerve. (2) Additionally, in situ hybridization showed that there was no change in the expression of PN3 mRNA in the DRG up to 14 d after CCI. PN3 mRNA was not detected in sections of brain and spinal cord taken from either normal or nerve-injured rats. (3) In contrast, immunohistochemical studies showed that major changes in the subcellular distribution of PN3 protein were caused by either CCI or complete transection of the sciatic nerve. The intensity of PN3 immunolabeling decreased in small DRG neurons and increased in sciatic nerve axons at the site of injury. The alteration in immunolabeling was attributed to translocation of presynthesized, intracellularly located PN3 protein from neuronal somata to peripheral axons, with subsequent accumulation at the site of injury. The specific subcellular redistribution of PN3 after peripheral nerve injury may be an important factor in establishing peripheral nerve hyperexcitability and resultant neuropathic pain.  相似文献   
999.
1000.
Despite advances in treatment of brain tumors, cerebral malignant gliomas are rapidly debilitating with poor survival. Patient age and tumor histology are known to influence survival in glioma patients, but these factors do not account for all of the variability in survival time. To identify additional useful predictors, we tested an assay that measures intrinsic gamma-ray mutagen sensitivity. Our hypothesis was that increased sensitivity of peripheral blood lymphocytes to chromatid breaks is associated with tumor aggressiveness and decreased patient survival. The eligible 76 patients were those with histologically confirmed malignant gliomas, seen at the University of Texas M. D. Anderson Cancer Center between 1994 and 1997, for whom we had sufficient blood for the in vitro gamma-radiation assay. After gamma-irradiation of each subject's lymphocytes, the frank chromatid breaks in 50 metaphases were averaged to calculate breaks/cell. On the basis of our patient series, we established a gamma-ray mutagen sensitivity cutoff point of 0.55 breaks/cell that was confirmed by bootstrap resampling techniques. Patients with values >0.55 breaks/cell were considered sensitive. Kaplan-Meier and Cox proportional hazards modeling were used for the analysis. The gamma-ray mutagen-sensitive patients had worse survival than the nonsensitive patients, with an unadjusted hazard rate ratio of 1.6 (95% confidence interval, 0.9-2.8; P = 0.15). After adjustment for age, tumor histology, and extent of surgical resection, the hazard rate ratio was 2.4 (95% confidence interval, 1.3-4.6; P = 0.0081). Our data suggest that gamma-ray mutagen sensitivity is a prognostic indicator of survival in glioma patients. The significance of these findings needs to be verified in studies with larger samples of patients with histologically similar gliomas.  相似文献   
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