Relation between retirement and subsequent health status in highly educated older men.
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Aged↗
Biomedical subjects
Mei He
Publications and source records attributed to Mei He.
[Mandibular condensability and length contraction: an animal experimental study].
OBJECTIVE: To investigate the condensability of mandibular length. METHODS: In six goats were used in the study. Corticotomy at right mandibular angles was performed via extral-oral accession. Special devices were applied to shorten the mandible by 0.5 mm per three days respectively. RESULTS: 1. Mandibular angles of the six goats were shorten by 0.8 cm to 1.3 cm respectively in 48 days to 78 days; 2. In spite of the lower ascending ramus moving forward and angles being blunt, the occlusion scarcely varied because of contralateral bite-lock; 3. X-ray demonstrated that, at first, bone density in contracted areas declined, and then increased gradually to almost normal density; 4. Under microscope there were three tissues layers from central to lateral within the bone gap: fiber layer, cartilage layer and bone layer, and fiber layer gradually transform into cartilage layer with the fixed time. At the end of fixation they all transform into bone tissue. CONCLUSION: Contraction osteogenesis is actually a process of compression, absorption and rebuilding. It is feasible that using contraction osteogenesis to shorten the mandible via cortcotomy.
Animals↗
[Digestive and absorptive characteristic of starches determined in vitro and in vivo].
OBJECTIVE: To compare the different digestive and absorptive characteristic of digestible starch (DS) and resistant starch (RS), using both in vitro and in vitro methods. METHODS: Firstly, DS and RS content in four starchy samples were determined in vitro according to Englyst's method. Secondly, DS and RS digestion and absorption were evaluated by determination of four-hour blood glucose level, after direct injection of DS and RS solution into rats' duodenum. And in another animal test, the effect of RS on apparatus absorption rate of carbohydrate and nitrogen and secretion of gastric acid and pepsin was observed. RESULTS: In vitro, it was showed that general cornstarch was rich of DS, while 76% of potato starch was RS. In vitro, it was tested that after injection of DS into duodenum, most of DS could be absorbed in 120 min with high peak value of plasma glucose. While, RS needed more time to complete its absorption, and its apparatus absorption was up to 96%. It was also showed that RS could increase fecal nitrogen excretion, decrease nitrogen apparatus absorption rate and change gastric acid and pepsin excretion. CONCLUSION: By both in vitro and in vitro methods, RS is identified to be absorbed slowly but completely. The results partly support Englyst's method, which regards 120min as the time point to separate DS with RS in vitro.
Animals↗
[Influence of live flora on lactose digestion in male adult lactose-malabsorbers after dairy products intake].
OBJECTIVE: To evaluate the effect of live flora on lactose absorption in male adult lactose-malabsorbers. METHODS: After giving consents, 45 health male adult volunteers were challenged with 20 g lactose in 200 ml water in the morning without breakfast. The expired samples of breath were collected at every 30 min point in 3 hours. 24 persons were chosen as subjects (lactose-malabsorbers) when their expired H2 of any time point was 30 micromol/mol more than the baseline, and divided into 3 groups randomly. The test dairy were yogurt (Y) and heat-treated yogurt (HY), and acidified gelled milk (M), all containing 20 g lactose. The study was double blind, randomized and 3 x 3 latin square design. Three group subjects ingested the 3 different dairy products in 3 different days. The washout time was 7 days. After drinking each dairy in the morning without breakfast, the expired samples at every 30 min were collected during 8 hours test time with no food and no violent exercise. Hydrogen concentration of expired sample was detected by gas chromatography. RESULTS: The peak hydrogen concentration (Cmax) of yogurt is significant less than heat-treated yogurt and milk (Y 113.2 +/- 70.2, HY 186.5 +/- 96.7, M 174.7 +/- 73.9). The peak time of Cmax (Tmax) of yogurt is significant more than milk (Y 390 +/- 86, M 305 +/- 105). The area under the hydrogen concentration curve (AUC) of yogurt is significant less than the other two dairy products (Y 14,900.1 +/- 12,206.2, HY 27,389.5 +/- 20,429.8, M 25,648.2 +/- 14,064.0). CONCLUSION: The live flora in dairy product could improve lactose digestion in male adult lactose malabsorbers.
Adult↗
[Ultrastructural changes in cerebral cortex and cerebellar cortex of rats under simulated weightlessness].
OBJECTIVE: To study the ultrastructural changes in the cerebral cortex and cerebellar cortex of rats under simulated weightlessness and the possible mechanism. METHOD: The tail-suspended rats model (-30 degrees head down tilt) was adopted to simulate weightlessness in the experiment. The rats were suspended for 7 d, 14 d, 21 d, and 28 d, and then were perfused through the hearts. The specimens were drawn from the rats' cerebral cortex and cerebellar cortex for electron microscopy. RESULT: The results showed that under simulated weightlessness, the main changes in the neuron can be described as follows: swelling of mitochondria, endoplasmic reticulum and Golgi complex, even formation of big empty vesicles; reduction of number of synaptic vesicles in IV layer; increase corrugation of capillary lumen and thickening of basement membrane. Degranulation of rough endoplasmic reticulum in Purkinje's cells of the cerebellar cortex occurred obviously. On the 14th and the 21st day of suspension, the changes were most significant and tended to return to normal on the 28th day. CONCLUSION: The experimental results demonstrated that simulated weightlessness led to ultrastructural changes in the cerebral cortex and cerebella cortex of rats. The ultrastructure changed with the course of simulated weightlessness and tended to return to normal. It showed an adaption to the simulated weightlessness.
Adaptation, Physiological↗
The minimum LOH region defined on chromosome 17p13.3 in human hepatocellular carcinoma with gene content analysis.
Hepatocellular carcinoma (HCC) is one of the most common human cancers in Asia. Previous studies have shown that in addition to aberrations of the p53 gene on chromosome 17p13.1, other gene(s) on chromosome 17p13.3 may also play a role in HCC. To detect the status of loss of heterozygosity (LOH) in HCC and to determine the minimum region of LOH on 17p13.3, we analyzed 22 paired HCC and non-cancerous liver samples with 14 polymorphic markers plus TP53 (p53 gene) as a comparison. The data revealed a high level of LOH (>68%) in a minimum region between D17S1866 and D17S1574, spanning over a 1.5 Mb region. Genomic library screening using markers in the region has resulted in the isolation of a cluster of BAC/PAC clones. We created a physical map in this region. Using large-scale genome sequencing, gene annotation, cDNA screening, and exon trapping, we identified 17 known genes and 13 novel genes in the minimum region. The function of these genes was analyzed and the possibility of several putative tumor suppressor genes was discussed.
Base Sequence↗
The buccinator musculomucosal island flap for partial tongue reconstruction.
BACKGROUND: Ideal tongue reconstruction after partial or total glossectomy should be accomplished with like tissue. The buccinator musculomucosal island flap is similar to lingual tissue, consisting of thin, pliable mucosa of mucus production, with high cell renewal rate and minimal scar formation, excellent color, contour, texture match, and buccinator muscle fibers over the flap's entire length, providing tongual muscle reconstruction without a conspicuous donor site. STUDY DESIGN: The buccinator musculomucosal island flap, based on the facial artery and vein, is designed in a shuttle or in a fish-mouth fashion, encompassing the oral commissure anteriorly. If the flap design is made in a three-leaf shape, a larger flap will be obtained without an oral corner deformity or mouth opening difficulty. The flap is safe and simple to raise. The pedicle of the flap is longer and quite reliable and has a wide range of applicability. The flap may be used for reconstruction of the partial glossectomy defect (tongual defect was not more than half a tongue). The surgeon must know about possible anatomic variations, especially in the venous system, and plan to raise a contralateral buccinator musculomucosal island flap if homolateral facial vascular variation jeopardizes the flap's survival. RESULTS: The flap was successfully used for partial tongue reconstruction in 16 patients, and all flaps have survived without complications. Satisfactory results (including configuration and function of the neotongue) were achieved. Electromyographic studies performed on one patient with half glossectomy revealed reinnervation of the muscle in the flap with active motion of the reconstructed tongue. CONCLUSION: The buccal musculomucosal island flap based on the facial artery and vein is a better reconstruction option with the same or similar kind of tissue as the tongue and, with the addition of the reinnervated flap, offers the potential for improved physiologic motion.
Adult↗
Identification of Src transformation fingerprint in human colon cancer.
We used a classical rodent model of transformation to understand the transcriptional processes, and hence the molecular and cellular events a given cell undergoes when progressing from a normal to a transformed phenotype. Src activation is evident in 80% of human colon cancer, yet the myriad of cellular processes effected at the level of gene expression has yet to be fully documented. We identified a Src 'transformation fingerprint' within the gene expression profiles of Src-transformed rat 3Y1 fibroblasts demonstrating a progression in transformation characteristics. To evaluate the role of this gene set in human cancer development and progression, we extracted the orthologous genes present on the Affymetrix Hu95A GeneChip (12k named genes) and compared expression profiles between the Src-induced rodent cell line model of transformation and staged colon tumors where Src is known to be activated. A similar gene expression pattern between the cell line model and staged colon tumors for components of the cell cycle, cytoskeletal associated proteins, transcription factors and lysosomal proteins suggests the need for co-regulation of several cellular processes in the progression of cancer. Genes not previously implicated in tumorigenesis were detected, as well as a set of 14 novel, highly conserved genes with here-to-fore unknown function. These studies define a set of transformation associated genes whose up-regulation has implications for understanding Src mediated transformation and strengthens the role of Src in the development and progression of human colon cancer. Supportive Supplemental Data can be viewed at http://pga.tigr.org/PGApubs.shtml.
Animals↗
Prevalence and spectrum of p53 mutations associated with smoking in breast cancer.
To explore the role of smoking in breast cancer, we undertook a population-based study to evaluate the prevalence and spectrum of p53 mutations in the breast tumors of smokers and nonsmokers. We evaluated 456 archival invasive breast tumors for mutations in exons 4-8 of the p53 gene, using single-strand conformational polymorphism analysis and manual sequencing. Statistical analyses were performed to determine the association of p53 mutations with clinical and smoking characteristics. Of 108 mutations identified, 77 (71%) were point mutations and 31 (29%) were deletions or insertions. A higher prevalence of p53 mutations was found in the breast tumors of current smokers (36.5%; P = 0.02) compared with never smokers (23.6%), whereas fewer mutations were found in former smokers (16.2%; P = 0.09). After adjustment for age, race, menopausal status, clinical stage, tumor size, and family history of breast cancer, current smokers were significantly more likely to harbor any p53 mutation [odds ratio (OR), 2.11; 95% confidence interval (CI), 1.17-3.78], p53 transversions (OR, 3.37; 95% CI, 1.03-11.06), and G:C-->T:A transversions (OR, 10.53; 95% CI, 1.77-62.55) compared with never smokers. Stage at diagnosis did not account for the increase in p53 mutation-positive breast cancer among current smokers. Former smokers were also more likely than never smokers to harbor G:C-->T:A transversions (OR, 2.43; 95% CI, 0.37-15.73), although this association was not statistically significant. Among former smokers, the prevalence of p53 mutations varied with time since quitting: former smokers who quit smoking for longer than 1 year had a lower prevalence of p53 mutations (10.5% for 1-5 years and 12.9% for >5 years) than those who had stopped smoking within the year of their cancer diagnosis (26.3%). Our results indicate that cigarette smoking appears to modify the prevalence and spectrum of p53 mutations in breast tumors. Moreover, the difference in mutational spectra observed between smokers and nonsmokers is suggestive of the genotoxic effects of smoking in breast tissue.
Adult↗
Identification of Myc-mediated death response pathways by microarray analysis.
To understand the mechanisms of Myc-mediated apoptosis induced by DNA damage, we have characterized the death kinetics of three Rat-1 fibroblast cell lines that either overexpress Myc or lack Myc and their parental wild-type cells following exposure to the DNA-damaging agent VP-16, and we monitored the changes in gene expression using microarray. We have identified three groups of genes whose expressions are distinctly regulated during this process. One cluster (Cluster A) revealed a VP-16-dependent but Myc-independent induction of a set of genes that is not linked to the apoptotic response. Two other gene clusters, however, were associated with VP-16-induced apoptosis. Cluster B, which includes p53-responsive genes, was associated with the temporal onset of apoptosis but accounted for only the basal apoptosis. However, Cluster C, which includes c-jun, was highly regulated by Myc and appeared to be critical to mounting the maximal apoptotic response in Myc-expressing cells. Furthermore, the Myc level dropped sharply following VP-16 exposure, which varied inversely with the induction of Cluster C genes, suggesting Myc normally represses their transcription. Thus, we have proposed that removal of Myc-mediated repression of apoptotic signals, combined with Myc-associated acceleration of the p53 responsive pathway, results in complete and rapid cell death following DNA damage.
Animals↗
cDNA microarray profiling of rat mammary gland carcinomas induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and 7,12-dimethylbenz[a]anthracene.
cDNA microarray analysis was used to examine gene expression profiles in normal female Sprague-Dawley rat mammary gland and in carcinomas induced by the cooked meat-derived carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and the potent experimental carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). Nine tubulopapillary carcinomas (five from PhIP-treated rats and four from DMBA-treated rats) and normal mammary gland from virgin, pregnant and lactating rats were examined on a rat 6.9k cDNA microarray. Although histologically identical, PhIP- and DMBA-induced carcinomas could be distinguished by hierarchical clustering and multi-dimensional scaling analyses of cDNA expression. In addition, the expression of 21 clones was statistically different between PhIP- and DMBA-induced carcinomas (F-test, P < 0.05). The data indicate that distinct chemical carcinogens induce unique gene expression patterns in mammary gland carcinomas. The specific chemical carcinogen-associated cDNA array profiles found in carcinomas may ultimately be applicable to better understanding cancer etiology. PhIP- and DMBA-induced carcinomas also shared similarities in cDNA expression profiles. By comparing the expression in carcinomas (PhIP plus DMBA induced) with normal rat mammary gland (at any stage of differentiation), 172 clones were found to be differentially expressed. Genes showing increased expression in carcinomas by cDNA microarray analysis (and further validated by immunohistochemistry and western blot analysis) include cyclin D1, PDGF-A chain, retinol binding protein 1, prohibitin and the transcription factor STAT5A. The similarities in gene expression between PhIP- and DMBA-induced carcinomas raise the possibility that several molecular pathways for rat mammary gland transformation are maintained irrespective of the carcinogenic initiating agent.
9,10-Dimethyl-1,2-benzanthracene↗
Effect of micronutrient supplementation on the growth of preschool children in China.
OBJECTIVE: To study the relationship between micronutrient supplementation and children growth. METHODS: A double-blind, placebo-controlled trial was conducted in 156 growth retarded preschool children. They were randomly assigned to five groups: supplemental control (S-control, n = 28), zinc supplementation (+Zn, 3.5 mg Zn/day, n = 34), zinc and calcium supplementation (+ZnCa, 3.5 mg Zn + 250 mg Ca/day, n = 37), zinc and calcium and vitamin A supplementation (+ZnCaVA, 3.5 mg Zn + 250 mg Ca + 200 g VA/day, n = 28), Calcium, and vitamin A supplementation (+CaVA, 250 mg Ca + 200 g VA/day, n = 29). Another 34 children with normal height were selected as normal control (N-control). Supplementation continued for twelve months. RESULTS: The height gain in +Zn group (7.84 cm per year) and +ZnCa group (7.70 cm per year) was significantly higher than that in S-control group (6.74 cm per year, P < 0.05); The weight gain in +ZnCaVA group (2.55 kg per year) and +CaVA group (2.57 kg per year) was also significantly higher than that in S-control group (2.19 kg per year, P < 0.05); The average days of illness in each supplementation group were lower than that in S-control (13 days per year compared with 23 days per year). No significant difference was observed on bone age. CONCLUSION: Zinc and Zinc + Calcium supplementation can improve the height gain, and vitamin A can improve weight gain in growth retarded preschool children, but do not affect the maturity of bone. Micronutrient supplementation can lower the morbidity of these children.
Body Height↗