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21.
Rao VM; Dalinka MK; Mitchell DG; Spritzer CE; Kaplan F; August CS; Axel L; Kressel HY 《Radiology》1986,161(1):217-220
Four patients with proved osteopetrosis (three with the infantile malignant form and one with the benign form) were examined with magnetic resonance imaging at 1.5 T. All patients were studied in the coronal and sagittal planes using both short and long repetition time/echo time sequences. The infantile malignant form was characterized by a complete lack of signal from the marrow alternating with a signal intensity equivalent to that of the intervertebral disks, resulting in a "stepladder" appearance. In the benign form or after successful marrow transplantation in the infantile malignant form, intermediate or high signal intensity in the vertebrae was noted, suggesting the presence of some marrow elements. 相似文献
22.
Objective To detect new mutations among 29 glucose-6-phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province. Methods The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient individuals. Mutation was identified by single strand conformation polymorphism (SSCP), amplification created restriction site (ACRS), amplification refractory mutation system (ARMS) and DNA sequencing. Results Among 29 cases, 18 cases of G1388A, 1 case of C1004A, and 1 case of G1381A were identified. Nine cases remained to be defined. The G1381A mutation is a novel mis-sense mutation, with a substitution of threonine for alanine (A461T). The resultant G6PD had reduced enzymatic activity. In addition, G1381A caused a restriction site of Stu I to disappear, providing a rapid method for the detection of this mutation. Conclusion A novel mis-sense mutation G1381A was found. This mutation results in a substitution of threonine for alanine, producing enzyme with reduced activity. The loss of the Stu I restriction site offers a rapid method for the detection of this mutation. 相似文献
23.
Aneurysm of sinus of Valsalva dissecting into interventricular septum is a rare entity. We report one such case who was incidentally diagnosed by echocardiography to have this abnormality during evaluation of a clinically suspected isolated aortic regurgitation.KEY WORDS: Aneurysm – dissecting – sinus of Valsalva, Echocardiography 相似文献
24.
Minority status within any larger group is often difficult. Lesbian nurses face a dilemma of choice—whether or not to come out of the closet to their colleagues and patients. This essay describes the professional reflections of one lesbian nurse. 相似文献
25.
Prognostic significance of c-kit mutation in localized gastrointestinal stromal tumors. 总被引:16,自引:0,他引:16
Tae Won Kim Hyoungnam Lee Yoon-Koo Kang Mi Sun Choe Min-Hee Ryu Heung Moon Chang Jung Sun Kim Jeong Hwan Yook Byung Sik Kim Jung Shin Lee 《Clinical cancer research》2004,10(9):3076-3081
PURPOSE: Constitutive mutational activation of c-kit has been found to be associated with the pathogenesis of gastrointestinal stromal tumors (GISTs). The prognostic significance of c-kit mutations, however, is still controversial. EXPERIMENTAL DESIGN: We examined 86 patients curatively resected for localized GIST. Genomic DNA was extracted from paraffin-embedded tumor tissues. Exons 9, 11, 13, and 17 of the c-kit gene were amplified by PCR and sequenced. RESULTS: Mutations in exon 11 were detected in 61 tumors, and mutations in exon 9 were observed in three tumors, whereas no mutations were detected in exons 13 or 17. The overall c-kit mutation frequency was 74%. Amino acid alterations in the 61 tumors with exon 11 mutations were deletion in 33 tumors, substitution in 20, both deletion and substitution in 4, insertion in 1, and duplication in 3. Histologically, tumors with c-kit mutations showed higher mitotic counts and higher cellularity. The 5-year relapse-free survival (RFS) in patients having GISTs with c-kit mutations was 21%, compared with 60% in those without c-kit mutations. Significantly higher RFS rates were observed in patients with tumors having mitotic counts < 5 mitoses/50 high power field, spindle-cell histology, tumor size < 5 cm, or gastric GISTs. Multivariate analyses indicated association of poorer RFS with a higher mitotic count > or = 5 of 50 high power fields; odds ratio (OR) = 3.0], presence of c-kit mutations (OR = 5.6), and a larger tumor size (> or = 5 cm; OR = 4.2). CONCLUSIONS: The presence of c-kit mutation, along with high mitotic count and larger tumor size, was an independent factor for poor prognosis in patients with localized GISTs. 相似文献
26.
Inhibition of growth and induction of apoptosis in human cancer cell lines by tea polyphenols 总被引:47,自引:7,他引:47
In order to study the biological activities of tea preparations and
purified tea polyphenols, their growth inhibitory effects were investigated
using four human cancer cell lines. Growth inhibition was measured by
[3H]thymidine incorporation after 48 h of treatment. The green tea
catechins (-)-epigallocatechin-3-gallate (EGCG) and (-)- epigallocatechin
(EGC) displayed strong growth inhibitory effects against lung tumor cell
lines H661 and H1299, with estimated IC50 values of 22 microM, but were
less effective against lung cancer cell line H441 and colon cancer cell
line HT-29 with IC50 values 2- to 3- fold higher.
(-)-Epicatechin-3-gallate, had lower activities, and (-)- epicatechin was
even less effective. Preparations of green tea polyphenols and theaflavins
had higher activities than extracts of green tea and decaffeinated green
tea. The results suggest that the growth inhibitory activity of tea
extracts is caused by the activities of different tea polyphenols. Exposure
of H661 cells to 30 microM EGCG, EGC or theaflavins for 24 h led to the
induction of apoptosis as determined by an annexin V apoptosis assay,
showing apoptosis indices of 23, 26 and 8%, respectively; with 100 microM
of these compounds, the apoptosis indices were 82, 76 and 78%,
respectively. Incubation of H661 cells with EGCG also induced a
dose-dependent formation of H2O2. Addition of H2O2 to H661 cells caused
apoptosis in a manner similar to that caused by EGCG. The EGCG-induced
apoptosis in H661 cells was completely inhibited by exogenously added
catalase (50 units/ml). These results suggest that tea polyphenol-induced
production of H2O2 may mediate apoptosis and that this may contribute to
the growth inhibitory activities of tea polyphenols in vitro.
相似文献
27.
Characterization of xenobiotic-metabolizing enzymes and nitrosamine metabolism in the human esophagus 总被引:5,自引:2,他引:5
Smith TJ; Liao A; Wang LD; Yang GY; Starcic S; Philbert MA; Yang CS 《Carcinogenesis》1998,19(4):667-672
Esophageal cancer has been associated with tobacco smoking, and
nitrosamines are possible causative agents for this cancer. The present
study investigated the metabolism of the tobacco carcinogens N'-
nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanone
(NNK), and N-nitrosodimethylamine (NDMA), as well as the presence of
xenobiotic-metabolizing enzymes in human esophageal tissues from
individuals in the United States and Huixian, Henan Province, China (a
high-risk area for esophageal cancer). All esophageal microsomal samples
activated NNN and the metabolic rate was 2-fold higher in the esophageal
samples from China than the USA. All microsomal samples activated NDMA.
However, most of the microsomal samples did not activate NNK.
Troleandomycin (an inhibitor of cytochrome P450 3A) decreased the formation
of NNN-derived keto acid by 20-26% in the esophageal microsomes. The
activities for NADPH: cytochrome c reductase, ethoxycoumarin O-deethylase,
NAD(P)H: quinone oxidoreductase and glutathione S-transferase were present
in the esophageal samples. Coumarin 7-hydroxylase (a representative
activity for P450 2A6) activity was not detected in the esophageal
microsomal samples. The activities for nitrosamine metabolism and
xenobiotic- metabolizing enzymes were decreased (by 30-50%) in the squamous
cell carcinomas compared with their corresponding non-cancerous mucosa. The
presence of activation and detoxification enzymes in the esophagus may play
an important role in determining the susceptibility of the esophagus to the
carcinogenic effect of nitrosamines. Our results suggest that P450s 3A4 and
2E1 are involved in the activation of NNN and NDMA, respectively, in the
human esophagus.
相似文献
28.
Jane Dimmitt Champion PhD FNP CS ; Pat Kelly PhD FNP ; Rochelle N. Shain PhD ; Jeanna M. Piper MD 《The Journal of rural health》2004,20(3):279-285
CONTEXT: There is a need for community-based, culturally sensitive, cognitive-behavioral interventions to reduce sexual risk behavior among minority adolescents. Studies of adolescent risk and protective behaviors have focused on identifying modifiable psychosocial variables that predict differential outcomes for subsequent intervention efforts. Research has been scarce in studies of rural minority adolescent women. PURPOSE: To examine the protective and risk behaviors of these rural Mexican-American adolescent women and their relationship to physical or sexual abuse. METHODS: Mexican-American adolescent women aged 14-19 years were recruited through a rural health clinic and administered a self-report assessment for protective and risk behavior and sexual, physical, and psychological abuse. FINDINGS: Rural minority adolescent women endured high levels of psychological distress and many risk behaviors yet experienced few protective behaviors. Barriers to health care included access and confidentiality. Physically or sexually abused adolescents endured relatively greater risk and fewer protective behaviors than nonabused. CONCLUSIONS: Rural Mexican-American adolescent women may benefit from confidential identification and assessment of abuse history and risk and protective behaviors so that appropriate psychological treatment can accompany accessible medical treatment. The prevalence of risk behaviors and abuse among these women presents a need for development of behavioral interventions for risk reduction and promotion of health protective behaviors. 相似文献
29.
Joanne M. Pohl PhD RN CS Charles W. Given PhD Clare E. Collins PhD RN FAAN Barbara A. Given PhD RN FAAN 《Health care for women international》2013,34(5):385-395
Variables that have been conceptually linked with social vulnerability—income, educational level, employment, cessation of work to provide care, marital status, social support, and health—were used to predict four categories of reaction to caregiving in 159 daughters and daughters‐in‐law caring for their disabled aging parents. Social support, income, and health best predicted negative reactions to caregiving; social support alone best predicted feelings of family abandonment, impact on health, and impact on schedule. Compared with daughters and daughters‐in‐law who had not quit work to provide care, those who had quit work were significantly older, had lower incomes and fewer social supports, and were more involved in care. The results suggest that quitting work may be a precursor to social isolation that places the caregiver at increased risk for social vulnerability and negative reaction to caregiving. The implications of the findings for health care policy are discussed. 相似文献
30.
Erin S Calipari Mark J Ferris Benjamin A Zimmer David CS Roberts Sara R Jones 《Neuropsychopharmacology》2013,38(12):2385-2392
The dopamine transporter (DAT) is responsible for terminating dopamine (DA) signaling and is the primary site of cocaine''s reinforcing actions. Cocaine self-administration has been shown previously to result in changes in cocaine potency at the DAT. To determine whether the DAT changes associated with self-administration are due to differences in intake levels or temporal patterns of cocaine-induced DAT inhibition, we manipulated cocaine access to produce either continuous or intermittent elevations in cocaine brain levels. Long-access (LgA, 6 h) and short-access (ShA, 2 h) continuous self-administration produced similar temporal profiles of cocaine intake that were sustained throughout the session; however, LgA had greater intake. ShA and intermittent-access (IntA, 6 h) produced the same intake, but different temporal profiles, with ‘spiking'' brain levels in IntA compared with constant levels in ShA. IntA consisted of 5-min access periods alternating with 25-min timeouts, which resulted in bursts of high responding followed by periods of no responding. DA release and uptake, as well as the potency of cocaine for DAT inhibition, were assessed by voltammetry in the nucleus accumbens slices following control, IntA, ShA, and LgA self-administration. Continuous-access protocols (LgA and ShA) did not change DA parameters, but the ‘spiking'' protocol (IntA) increased both release and uptake of DA. In addition, high continuous intake (LgA) produced tolerance to cocaine, while ‘spiking'' (IntA) produced sensitization, relative to ShA and naive controls. Thus, intake and pattern can both influence cocaine potency, and tolerance seems to be produced by high intake, while sensitization is produced by intermittent temporal patterns of intake. 相似文献