This is first report about the simultaneous over-expression of both Insulin-like growth factor (IGF-II) and its receptor (IGF-II
R) at mRNA level in human primary hepatic Cancer (PHC). In 10 PHC samples from China, IGF-II and IGF-II R were both over-expressed,
whereas only a background signal was detected in normal liver. In 5 pairs of PHC and its non-tumorous adjacent liver tissues
from South Africa, IGF-II and IGF-II R were also over-expressed in PHC. mRNA expression of IGF-II in all 5 cases and IGF-II
R in 4 of 5 cases were higher in cancer than non-tumorous adjacent liver tissues. These results strongly implicate that an
autocrine and/or paracrine mechanism might be involved in formation and progression of PHC. 相似文献
Previous studies examining the association between social comparison processes and body image dissatisfaction have yielded inconsistent findings. This study examined whether such discrepancies are due to either the use of identical comparison targets for all subjects or variability in body mass. Specifically, 216 subjects were randomly assigned to one of three experimental conditions: self-generated upward comparison group, self-generated downward comparison group, or control group. Dependent variables were measures of body image. Results indicated that increasing body mass and trait comparison tendencies were associated with increased body dissatisfaction. However, the experimental manipulation did not affect body image ratings. Results suggest that social comparison processes may operate similarly over a range of body mass index (BMI) values. 相似文献
Background: Sweating, vasoconstriction, and shivering have been observed during general anesthesia. Among these, vasoconstriction is especially important because-once triggered-it minimizes further hypothermia. Surprisingly, the core-temperature plateau associated with vasoconstriction appears to preserve core temperature better in infants and children than adults. This observation suggests that vasoconstriction in anesthetized infants may be accompanied by hypermetabolism. Consistent with this theory, unanesthetized infants rely on nonshivering thermogenesis to double heat production when vasoconstriction alone is insufficient. Accordingly, the authors tested the hypothesis that intraoperative core hypothermia triggers nonshivering thermogenesis in infants.
Methods: With Ethics Committee approval and written parental consent, the authors studied six infants undergoing abdominal surgery. All were aged 1 day to 9 months and weighed 2.4-9 kg. Anesthesia was maintained with propofol and fentanyl. The infants were mechanically ventilated and allowed to cool passively until core (distal esophageal) temperatures reached 34-34.5 degrees Celsius. Oxygen consumption-the authors' index of metabolic rate- was recorded throughout cooling. Because nonshivering thermogenesis triples circulating norepinephrine concentrations, arterial blood was analyzed for plasma catecholamines at [nearly equal] 0.5 degrees Celsius intervals. Thermoregulatory vasoconstriction was evaluated using forearm - fingertip, skin-surface gradients, with gradients exceeding 4 degrees Celsius, indicating intense vasoconstriction. The patients were subsequently rapidly rewarmed to 37 degrees Celsius. Regression analysis was used to correlate changes in oxygen consumption and plasma catecholamine concentrations with core temperature.
Results: All patients were vasoconstricted by the time core temperature reached 36 degrees Celsius. Further reduction in core temperature to 34-34.5 degrees Celsius did not increase oxygen consumption. Instead, oxygen consumption decreased linearly. Hypothermia also failed to increase plasma catecholamine concentrations. 相似文献
Abstract: Our current understanding of human haematopoietic stem cell biology is based in part on the characterization of human CD34+ bone marrow cell differentiation in vitro. CD34 is highly expressed on early stem cells and haematopoietic progenitor cells with clonogenic potential and is gradually lost during differentiation and commitment. However, CD71 (transferrin receptor) is expressed at low levels on early stem cells and generally increases during haematopoietic progenitor cell proliferation. We reasoned that the combination of these surface markers would provide a useful framework for the simultaneous analysis of multiple lineage differentiation of CD34+ haematopoietic progenitor cells in liquid culture. In this report, we identify the phenotype of distinct subpopulations of myeloid, erythroid and lymphoid cells in liquid suspension culture using differential expression of CD34 vs. CD71 in combination with specific lineage markers. Freshly isolated human CD34+ bone marrow cells were introduced into suspension culture and monitored over a 6-d period using 3-colour flow cytometry. This is the first demonstration that differential expression of CD34 vs. CD71 can be used to simultaneously monitor differentiation of multiple haematopoietic cell lineages in liquid suspension culture, facilitating the study of cytokine-, drug- or chemical-induced alterations in haematopoietic progenitor cell differentiation in vitro.相似文献
PURPOSE: We have noted the frequent finding of an ipsilateral head turn in children with early-onset homonymous hemianopia. We report a series of patients with these findings and propose a theory to explain this association. METHODS: Ten patients with early-onset homonymous hemianopia and anomalous head posture were examined. Head computed tomography and magnetic resonance imaging confirmed a cerebral lesion as the cause of the hemianopia in all patients. RESULTS: All patients had onset of central nervous system disease prenatally or before age 18 months. A head turn toward the visual field defect with a gaze preference contralateral to the visual field defect was present in all patients. CONCLUSIONS: Early-onset homonymous hemianopia should be included in the differential diagnosis of anomalous head posture. 相似文献
Published data on TP53 mutations can be used to examine the question of
whether generalized hypermutability is a necessary condition for
tumorigenesis. Although individual mutations do play an etiologic role in
tumor formation, the evidence so far does not make it necessary to assume a
general mutability. Silent and multiple mutations in the TP53 data set
indicate that a special hypermutability process operates on this gene
during the generation of tumors. The percentage of silent p53 mutations
observed (3%) is at least 20 times greater than would be expected and
indicates hypermutability for this gene. The greater proportion of silent
mutations among multiple p53 mutations (10%) indicates that the mutations
occur nonselectively. The presence of silent mutations implies that not all
mutations observed in tumors have an etiologic role. Analysis of the
distribution of tumors with two, three, four and more p53 mutations
suggests that mutations in some tumors occur in clusters possibly as a
result of 'stuttering' in DNA synthesis. It is argued that the most likely
alternative explanations of the data, polymorphism and/or a selective role
for silent mutations, are not correct. It remains possible that the
hypermutability process is restricted to particular genes or to regions of
the genome as, for example, in antibody production. There is a surprising
paucity of data on human polymorphism and nucleotide diversity which makes
the analysis difficult.
相似文献
The suicide of Sylvia Plath is examined from the perspective of 15 theories of suicidal behavior and is found to fit best with psychoanalytic and cognitive theories of suicide , in particular those of Aaron Beck , Henry Murray , and Edwin Shneidman . 相似文献
The complexity of the RHD and RHCE genes, which is the greatest of all blood group systems, confounds analysis at the molecular level. RH DNA typing was introduced in 1993 and has been applied to prenatal testing. PCR-SSP analysis covering multiple polymorphisms was recently introduced for the screening and initial characterization of partial D. Our objective is to summarize the accrued knowledge relevant to the approaches to Rh phenotype prediction by DNA typing, their possible applications beyond research laboratories and their limitations. The procedures, results and problems encountered are highly detailed. It is recommended that DNA typing comprises an analysis of more than one polymorphism. We discuss future directions and propose a piecemeal approach to improve reliability and cost-efficiency of blood group genotyping that may eventually replace the prevalent serology-based techniques even for many routine tasks. Transfusion medicine is in the unique position of being able to utilize the most extensive phenotype databases available to check and develop genotyping strategies. 相似文献
The calcifying odontogenic cyst (COC) presents with diverse hlstologlcal features; thus, several subclasslfl-cations have been proposed. To evaluate the slgnlficance of the various histological features and subtypes of COC from the perspectlve of proliferative activity, the proliferating cell nuclear antigen (PCNA) labellng index (LI; the percentage of positive nuclei) was assessed immunohistochemlcally in 25 cases of COC (21 benign and four malignant). All of the benign cases were of the cystic variety and further subclas-sified into non-proliferative subtype (NPS; four cases); proliferative subtype (PS; eight cases); and COC associated with odontoma (COCaO, nlne cases). The PCNA U of the mallgnant COC (65.2 ± 5.6) was slgnlflcantly higher than that of the benlgn COC (11.6 ± 9.0; P = 0.002). Non-proliferative subtype (6.8 ± 2.8) showed the lowest PCNA LI and PS (17.2 ± 11.2) the highest of among the three subtypes of benign cystic COC (P = 0.028). In nine cases of COCaO, six showed epithelial lining of the non-proliferative type as NPS and the other three had lining wlth proliferative features as PS. The PCNA LI of the latter COCaO group (14.3 ± 6.6) was significantly higher than that of the former (6.1 ± 4.3; P = 0.05), as Seen between PS and NPS. These results demonstrate that PCNA LI is a possible parameter for differentiating mallgnant COC from benign COC and, whatever the subtypes, the proliferative features In the lining are the main factor influencing the prollferatlng actlvity of COC. 相似文献
Arterial oxygen saturation was measured by pulse oximetry in two groups of paediatric outpatients breathing room air during transport from the operating room to the postanaesthetic recovery room. In Group I (n = 60) readiness for transfer from OR to PARR was decided clinically. In Group II (n = 50) additional criteria of oxygen saturation (SaOe) greater than or equal to 98 per cent with end-tidal gas N2O less than or equal to 10 per cent and CO2 less than or equal to 45 mmHg were met. A higher incidence of desaturation (SaO2 less than or equal to 90 per cent) occurred in Group I (27 per cent) than in Group II (eight per cent) (P less than 0.05). More children under 2 yr desaturated in Group I (50 per cent) than Group II (17 per cent) (P greater than 0.05 less than 0.10). Twenty-two patients in each group had a recent history of upper respiratory tract infections. In these patients, desaturation was more marked in those in Group I (32 per cent) than in Group II (five per cent) (P less than 0.05). Within each group, the incidence of desaturation during transport was similar in patients with or without a recent URI. 相似文献