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Biomedical subjects

J Ma

Publications and source records attributed to J Ma.

661 records · Page 37Linked to original sources
PubMedDate not supplied

The influence of denervation on beta-amyloid protein precursor and alpha 1-antichymotrypsin in mouse skeletal muscle.

A serpin, alpha 1-antichymotrypsin (alpha 1-ACT), and Kunitz inhibitor containing forms of the beta-amyloid precursor protein (beta APP) may be important components of the balance between serine proteases and inhibitors in the nervous system. In the current report we studied whether axotomy affected the localization of beta APP and alpha 1-ACT in adult mouse muscle. Immunocytochemical experiments indicated that beta APP was present in normal muscle both at neuromuscular junctions and within intramuscular nerves. alpha 1-ACT was also present at neuromuscular junctions, on the perineurium of nerves and endothelial cell surfaces. Following axotomy, both beta APP and alpha 1-ACT disappeared from intramuscular nerves simultaneously. However, at the neuromuscular junction alpha 1-ACT decreased more rapidly with beta APP lingering before disappearing.

Amyloid beta-Protein Precursor↗
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Expression of HSP70-2 gene during germ cell apoptosis in rat unilateral cryptorchid testes.

To investigate the role of Hsp70-2 gene in germ cell apoptosis induced by heat stress, its expression changes were examined in rat normal and unilateral cryptorchid testes by using in situ hybridization, immunohistochemistry, and northern blot analysis techniques. The results showed that the expression level of Hsp70-2 gene declined slightly at the early stage of germ cell apoptosis, and dropped dramatically when most of the germ cells were undergoing apoptosis on day 7.5 after the induction of cryptorchidism. This report suggests for the first time that Hsp70-2 gene might not inhibit the apoptosis of germ cells at the early stage in cryptorchid testes. Hsp70-2 gene does not belong to the immediate early related genes that are responsible for germ cell apoptosis induced by heat stress.

Animals↗
PubMedDate not supplied

Serum-free culture of rhesus monkey embryonic stem cells.

Previous studies have shown that the maintenance and proliferation of undifferentiated rhesus monkey embryonic stem (rES) cells requires medium supplemented with fetal bovine serum (FBS). Due to the uncharacterized composition and variation in serum nature, the present study aimed to replace the serum-containing medium with a serum-free medium in the rES cell culture. The results showed that after the initial 48-h culture in the routinely used serum-containing medium, rES cells can grow and proliferate for a prolonged period in the serum-free medium composed of DMEM supplemented with a cocktail of BSA, IGF-1, TGF-alpha, bFGF, aFGF, estradiol, and progesterone. rES cells cultured in the serum-free medium maintained high level of alkaline phosphatase activity and OCT4 level. There was no indication of differentiation as judged by the marker gene expression of all three embryonic germ layers and trophoblast. In addition, serum-free culture would not affect the passage capacity and differentiation potential of rES cells. This work will facilitate the future study of induced differentiation of rES cells and other applications.

Alkaline Phosphatase↗
PubMedDate not supplied

Hyaluronic acid-poly-D-lysine-based three-dimensional hydrogel for traumatic brain injury.

Brain tissue engineering in the postinjury brain represents a promising option for cellular replacement and rescue, providing a cell scaffold for either transplanted or resident cells. In this article, a hyaluronic acid (HA)-poly-D-lysine (PDL) copolymer hydrogel with an open porous structure and viscoelastic properties similar to neural tissue has been developed for brain tissue engineering. The chemicophysical properties of the hydrogel with HA:PDL ratios of 10:1, 5:1, and 4:1 were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectrometry. Neural cells cultured in the hydrogel were studied by phase-contrast microscope and SEM. The incorporation of PDL peptides into the HA-PDL hydrogel allowed for the modulation of neuronal cell adhesion and neural network formation. Macrophages and multinucleated foreign body giant cells found at the site of implantation of the hydrogel in the rat brain within the first weeks postimplantation decreased in numbers after 6 weeks, consistent with the host response to inert implants in numerous tissues. Of importance was the infiltration of the hydrogel by glial fibrillary acidic protein-positive cells-reactive astrocytes-by immunohistochemistry and the contiguity between the hydrogel and the surrounding tissue demonstrated by SEM. These findings indicated the compatibility of this hydrogel with brain tissue. Collectively, the results demonstrate the promise of an HA-PDL hydrogel as a scaffold material for the repair of defects in the brain.

Animals↗
PubMedDate not supplied

New barium paste mixture for helical (slip-ring) CT evaluation of the esophagus.

Successful opacification of the lumen of the esophagus with cancer or paraesophageal diseases has not yet been fully achieved. Therefore, we have recently adopted a new method for complete and continuous opacification of the whole thoracic esophagus using our newly developed oral contrast agent with a helical (slip-ring) CT scanner. The agent consists of 3.6 (wt/vol)% carboxy-methyl cellulose sodium paste containing 2 (wt/vol)% barium sulfate. The results indicate that almost complete and continuous opacification of esophageal lumen was achieved. Our new method of esophageal CT is easy to perform and was well tolerated by patients, being therefore ideal for routine examinations.

Administration, Oral↗
PubMedDate not supplied

New barium paste mixture for helical (slip-ring) CT evaluation of rectal carcinoma.

We describe a new method for complete opacification of the rectum using helical CT and a newly developed anal contrast agent. Rectal cancers were easily identified in all of the 21 patients examined, and diagnostic accuracy in detecting local invasion was 94%. Our method of rectal CT is easy to perform and well tolerated.

Barium Sulfate↗
PubMedDate not supplied

Clustering of lifestyle behaviors: the relationship between cigarette smoking, alcohol consumption, and dietary intake.

PURPOSE: To examine relationships between cigarette smoking, alcohol use, and dietary intake. DESIGN: Respondents to the U.S. Department of Agriculture's Continuing Survey of Food Intakes by Individuals, a nationwide probability sample conducted from January 1994 through January 1997 (n = 23,602; response rate = 80%), were selected. Adults ages 19 years and older were grouped according to their smoking and drinking habits. Selected demographic variables, food group servings, food energy, and densities of selected nutrients were compared. SETTING: In-home interviews were conducted in the 50 states and the District of Columbia. SUBJECTS: The selected sample (n = 6745) included 3229 nonsmokers, 1701 former smokers, and 1808 current smokers, and 2284 abstainers, 2713 occasional drinkers, 1000 moderate drinkers, and 748 liberal drinkers. MEASURES: Responses to standard questionnaires were examined by Student's t-test, chi 2, one-way analysis of variance, and univariate and multivariate analyses of covariance. RESULTS: Men were more likely than women to be current smokers and liberal drinkers (64% vs. 40% and 62% vs. 38%). For both, the use of cigarettes and alcohol was closely related. An additive relationship was observed between smoking/drinking classification and lower food group servings and nutrient intakes. Although cigarette and alcohol use may have been underreported, these findings support previous ones showing poor food choices along with lower nutrient intakes as smoking and drinking increase. CONCLUSIONS: Smoking and drinking habits may alter individuals' food selections and nutrient intakes. Future interventions for health promotion may achieve greater success by targeting multiple risk factors simultaneously or sequentially.

Adult↗
PubMedDate not supplied

Measuring stage of change for assessing readiness to increase fruit and vegetable intake among 18- to 24-year-olds.

PURPOSE: To examine the appropriateness of the five-stage schema developed for addictive behaviors when applied to nonaddictive behaviors such as fruit and vegetable consumption. DESIGN: A cross-sectional mail survey was conducted. SETTING: Self-administered questionnaires were mailed to the home addresses of respondents recruited in 10 states and returned upon completion. SUBJECTS: In all, 116 male and 185 female young adults (response rate = 70%) completed the questionnaires. Most respondents were Caucasian (74.4%) and college students (62.2%). MEASURES: Statistical analyses included analysis of variance with Scheffe's test, Pearson correlation and Cronbach's alpha coefficients, factor analysis, and cluster analysis. RESULTS: Staging algorithms for fruits and vegetables were developed according to the five-stage schema, and their construct validity was verified by the incremental trend of food intakes. The algorithms identified more than 80% of the subjects as precontemplators, preparers, or maintainers for both food groups. This distribution pattern agreed well with the three-factor solution generated from the stages of change questionnaire, for which internal reliability and validity were confirmed. Seven cluster profiles of the respondents were derived based on the three generated factors and appeared to represent stage subgroupings of those factors. The two food groups shared marked similarities regarding the profiling of the clusters, which was validated by comparing food intake. The results, however, cannot be generalized because of limitations involved in the current sample. CONCLUSIONS: The original five stages of change and traditional staging measures may need to be adapted and/or extended for dietary change.

Adolescent↗
PubMedDate not supplied

Chondrocyte-mediated collagenolysis correlates with cartilage destruction grades in osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is associated with destruction of type II collagen-rich hyaline articular cartilage. We hypothesized that classical interstitial collagenases cleave collagen type II, leading to the increased expression of the 3/4 native type II collagen fragment (COL2-3/4C) and the corresponding denatured type II collagen fragment (COL2-3/4M), which could correlate with different cartilage destruction grades. In addition, we assessed whether these fragments could be measured in joint fluid and serve as diagnostic markers. METHODS: Cartilage specimens were obtained from the femoral heads of hip joints from total hip replacement operations. Articular gliding surfaces of the cartilage were categorized into normal (G0), fibrillated (G1), superficiallyfissured (G2) and deeplyfissured (fissures that reach to the subchondral bone) (G3). A histological scoring of the cartilage was also used. COL2-3/4C and COL2-3/4M were detected by immunohistochemical staining. Dot blotting was used to detect these fragments in joint fluid. RESULTS: COL2-3/4C and COL2-3/4M were found in the perichondrocyte matrix around lacunae. Such COL2-3/4C (p < 0.05) and COL2-3/4M (p < 0.05) immunoreactivity was significantly increased in G3 and G2 compared to GO and G1. A positive correlation (n = 35, Spearman rank correlation) was observed between the histological score and the percentage of COL2-3/4C positive lacunae (r = 0.43, p = 0.01) and COL2- 3/4M positive lacunae (r = 0.53, p = 0.001). All 7/7 joint fluid samples contained COL2-3/4C in dot blots whereas only 4/7 contained COL2-3/4M. CONCLUSION: Collagenase-cleaved collagen--both native and denatured--increases as the severity of OA increases, assessed using a macroscopic clinical and microscopic histological grading system. Collagen degradation was always most apparent around chondrocytes. Furthermore, the native COL2-3/4C fragment has potential as a joint fluid marker for OA.

Aged↗
PubMedDate not supplied

Pilot study of AIDS risk in the general population.

This study evaluated a methodology for obtaining information on the prevalence of risk behaviors for human immunodeficiency virus infection (HIV) in the general population. From two census tracts in an upper midwestern urban community, 334 households were identified at random. One adult between the ages of 18 and 55 years in each household was asked to complete a confidential questionnaire about knowledge and attitudes toward acquired immunodeficiency syndrome (AIDS) and risk behaviors for HIV infection. Half the responders were also asked to provide a blood sample for HIV serotesting. Response rates to the behavior questionnaire were high (85 to 90 percent). However, only 72 percent of those asked to provide a blood sample agreed to do so. Survey results showed low rates of HIV risk behavior in this population sample. The median number of lifetime sexual partners was five for men and three for women, and most reported contacts exclusively with persons of the opposite sex. Eleven percent of the men and 5 percent of the women reported having had sexual partners of the same sex during their lifetime. Seven percent of men and 3 percent of women reported same sex partners in the last 12 months. Very few reported extremely high-risk behaviors (that is, only one man reported multiple sexual partners with anal intercourse in the previous year). About one in five survey respondents reported having changed his or her behavior because of the AIDS epidemic, usually by being more selective about and reducing the number of sexual partners. Success of the methodology employed in this survey gives reason for optimism that population-based surveys of behavioral risks for HIV infection are feasible.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[A radiological study of the nasopharynx].

Since the difficulty to objectively assess the adenoidal tissue and the nasopharyngeal airway in children, it is necessary to find out an accurate method of measuring these structures. The present work studied the efficacy of the cavum lateral X-ray to measure the adenoidal tissue and to assess the obstruction in causes in the nasopharynx. With this purpose, different radiological measurements were carried out in 90 children who were going to undergo adenoidectomy. A significant correlation between these measurements and the volume and weight of the removed tissue was found. Also, a postadenoidectomy radiological control showed a significant decrease of the adenoidal tissue and a significant increase of the nasopharyngeal airway. The authors conclude that the lateral cavum X-ray is a good procedure to measure the adenoidal tissue and the nasopharyngeal airway.

Adenoidectomy↗
PubMedDate not supplied

Further characterization of negative regulatory element involved in the hormonal regulation of GlcNAc-1-P transferase gene in mouse mammary gland.

The gene encoding UDP-GlcNAc:dolichol phosphate N-acetylglucosamine-1-phosphate transferase (GPT), the enzyme that initiates the pathway for the biosynthesis of asparagine-linked glycoproteins, is ubiquitously expressed in eukaryotic cells. However, its expression in the mammary gland is developmentally and hormonally regulated; transcription of the mouse mammary GPT gene is stimulated by the lactogenic hormones, insulin, glucocorticoid, and prolactin. Earlier, we demonstrated that a distal negative regulatory element in mouse GPT (mGPT) promoter plays an important role in developmental and hormonal control of mGPT gene expression in mammary gland (Ma J, Saito H, Oka T and Vijay IK (1996) J Biol Chem, in press). In this report, a tissue distribution of the repressor that binds the negative regulatory element was examined; a comparison of the negative regulatory element to other consensus sequences for known transcription factors is discussed.

Animals↗