Mass transport of ATP within the motile sperm.
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Adenosine Triphosphate↗
Biomedical subjects
J Wei
Publications and source records attributed to J Wei.
Diffusion and convection in normal and neoplastic tissues.
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Animals↗
Tubular structures formed by pig erythrocyte globoside in aqueous systems.
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Animals↗
Knock-out mouse for Canavan disease: a model for gene transfer to the central nervous system.
BACKGROUND: Canavan disease (CD) is an autosomal recessive leukodystrophy characterized by deficiency of aspartoacylase (ASPA) and increased levels of N-acetylaspartic acid (NAA) in brain and body fluids, severe mental retardation and early death. Gene therapy has been attempted in a number of children with CD. The lack of an animal model has been a limiting factor in developing vectors for the treatment of CD. This paper reports the successful creation of a knock-out mouse for Canavan disease that can be used for gene transfer. METHODS: Genomic library lambda knock-out shuttle (lambdaKOS) was screened and a specific pKOS/Aspa clone was isolated and used to create a plasmid with 10 base pair (bp) deletion of exon four of the murine aspa. Following linearization, the plasmid was electroporated to ES cells. Correctly targeted ES clones were identified following positive and negative selection and confirmed by Southern analysis. Chimeras were generated by injection of ES cells to blastocysts. Germ line transmission was achieved by the birth of heterozygous mice as confirmed by Southern analysis. RESULTS: Heterozygous mice born following these experiments have no overt phenotype. The homozygous mice display neurological impairment, macrocephaly, generalized white matter disease, deficient ASPA activity and high levels of NAA in urine. Magnetic resonance imaging (MRI) and spectroscopy (MRS) of the brain of the homozygous mice show white matter changes characteristic of Canavan disease and elevated NAA levels. CONCLUSION: The newly created ASPA deficient mouse establishes an important animal model of Canavan disease. This model should be useful for developing gene transfer vectors to treat Canavan disease. Vectors for the central nervous system (CNS) and modulation of NAA levels in the brain should further add to the understanding of the pathophysiology of Canavan disease. Data generated from this animal model will be useful for developing strategies for gene therapy in other neurodegenerative diseases.
Amidohydrolases↗
Significantly higher frequency of the MspI 2.2 kb allele of the Duchenne muscular dystrophy intragenic probe P-20 in the Chinese population.
The P-20 intragenic marker was used to test for restriction fragment length polymorphisms in unrelated Chinese patients with Duchenne or Becker muscular dystrophy or X-linked mental retardation. In addition to polymorphism at the 6.0/3.5 kb MspI allelic site, we found an independent and high frequency of polymorphism at the 2.2/1.8 kb site. This differs from results found with other populations.
Alleles↗
Comparison of calcium-current in isolated atrial myocytes from failing and nonfailing human hearts.
To identify possible alterations of the L-type calcium currents (I(Ca),L) in cardiomyopathy, I(Ca),L were recorded in atrial myocytes dissociated from the nonfailing heart (NF) of patients undergoing corrective open-heart surgery and explanted failing heart (FH) of patients with dilated cardiomyopathy undergoing heart transplantation. The patch-clamp technique was applied in the single-electrode whole-cell mode. The electrophysiological properties of I(Ca),L, including cell capacitance and current density, were similar in atrial myocytes from both groups of patients. Further to identify possible alterations of the myocardial beta-adrenergic pathway in cardiomyopathy, we examined the effects of isoproterenol, forskolin, 8-Br-cAMP and IBMX on I(Ca),L in both groups of atrial myocytes. Perfusion of isoproterenol (1 microM) significantly increased the peak I(Ca),L by 515 +/- 44% in 6 atrial myocytes from NF but increased only by 135 +/- 25% in 27 atrial myocytes from FH. However, forskolin (1 microM) or 8-Br-cAMP (0.1 mM) increased the peak I(Ca),L to a similar extent in atrial myocytes from NF and FH. IBMX (20 microM) also induced a comparable increase in the peak I(Ca),L by 213 +/- 31% (n = 5) and 207 +/- 59% (n = 4) in atrial myocytes from NF and FH, respectively. The above findings suggest that in atrial myocytes obtained from FH the beta-adrenoceptor numbers might be decreased but no impairment of the signal transduction cascade occurred beyond the GTP binding proteins level.
1-Methyl-3-isobutylxanthine↗
The protective effect of niacinamide on ischemia-reperfusion-induced liver injury.
Reperfusion of ischemic liver results in the generation of oxygen radicals, nitric oxide (NO) and their reaction product peroxynitrite, all of which may cause strand breaks in DNA, which activate the nuclear enzyme poly(ADP ribose)synthase (PARS). This results in rapid depletion of intracellular nicotinamide adenine dinucleotide and adenosine 5'-triphosphate (ATP) and eventually induces irreversible cytotoxicity. In this study, we demonstrated that niacinamide, a PARS inhibitor, attenuated ischemia/reperfusion (I/R)-induced liver injury. Ischemia was induced by clamping the common hepatic artery and portal vein of rats for 40 min. Thereafter, flow was restored and the liver was reperfused for 90 min. Blood samples collected prior to I and after R were analyzed for methyl guanidine (MG), NO, tumor necrosis factor (TNF-alpha) and ATP. Blood levels of aspartate transferase (AST), alanine transferase (ALT) and lactate dehydrogenase (LDH) which served as indexes of liver injury were measured. This protocol resulted in elevation of the blood NO level (p < 0.01). Inflammation was apparent, as TNF-alpha and MG levels were significantly increased (p < 0.05 and p < 0.001). AST, ALT and LDH were elevated 4- to 5-fold (p < 0.001), while ATP was significantly diminished (p < 0.01). After administration of niacinamide (10 mM), liver injury was significantly attenuated, while blood ATP content was reversed. In addition, MG, TNF-alpha and NO release was attenuated. These results indicate that niacinamide, presumably by acting with multiple functions, exerts potent anti-inflammatory effects in I/R-induced liver injury.
Adenosine Triphosphate↗
The effect of head-down tilt on brain potentials related to visual attention.
To study the possible effect of simulated weightlessness on brain function state, the brain event-related potentials (ERPs) in a simple visual selective response task were compared between HDT and HUT in 9 normal subjects. The results were: The Target(T) and non-Target(NT) flash signals both induced significant slow positive potentials which were supposed to related to the attention state; the amplitude of the positive potentials in frontal regions decreased significantly especially for NT-ERPs during HDT compared with that during HUT. The data reported provide new evidence indicating that more attention should be paid on the brain function study during space flight.
Adult↗
The pedigree chart analysis of centenarians in Shanghai City.
The sex, occupation and pedigree charts of 57 centenarians in Shanghai City were investigated. There were 10 (17.5%) males and 47 (82.5%) females. Of the males, 4 were office workers (40%) and 6 were manual workers (60%). Among the females, 1 was an office worker (2.1%), 3 were manual workers (6.4%) and 43 were housewives (91.5%). Forty of the centenarians (70.2%) belonged to long-lived families, 17 (29.8%) did not. The age of centenarians' spouses influenced the mortality and age of their sons and daughters.
Journal Article↗
Autotransplantation of heart for repair of left ventricular rupture after mitral valve replacement.
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Adult↗
Dynamic change of ERPs related to selective attention to signals from left and right visual field during head-down tilt.
To study further the effect of head-down tilt (HDT) on slow positive potential in the event-related potentials (ERPs), the temporal and spatial features of visual ERPs changes during 2 hour HDT (-10 degrees) were compared with that during HUT (+20 degrees) in 15 normal subjects. The stimuli were consisted of two color LED flashes appeared randomly in left or right visual field (LVF or RVF) with same probability. The subjects were asked to make switch response to target signals (T) differentially: switching to left for T in LVF and to right for T in RVF, ignoring non-target signals(N). Five sets of tests were made during HUT and HDT. ERPs were obtained from 9 locations on scalp. The mean value of the ERPs in the period from 0.32-0.55 s was taken as the amplitude of slow positive potential(P400). The main results were as follows. 1) The mean amplitude of P400 decreased during HDT which was more significant at the 2nd, 3rd and 5th set of tests; 2) spatially, the reduction of mean P400 amplitude during HDT was more significant for signals from RVF and was more significant at posterior and central brain regions than that on frontal locations. As that the positive potential probably reflects the active inhibition activity in the brain during attention process, these data provide further evidence showing that the higher brain function was affected by the simulated weightlessness and that this effect was not only transient but also with interesting spatial characteristics.
Adult↗
Necessity of carnitine supplementation in semistarved rats fed a high-fat diet.
We investigated the effects of carnitine supplementation on lipid metabolism in semistarved rats. The semistarved rats were fed a high-fat diet and half the normal energy intake for 2 wk. Carnitine was supplied daily at a dose of 250 mg/kg of body weight. The results showed that the concentration of plasma free carnitine increased significantly in semistarved and carnitine-supplemented rats compared with normal and semistarved rats. The activities of muscle carnitine palmitoyltransferase I and preheparin plasma lipoprotein lipase also were significantly increased in semistarved and carnitine-supplemented rats. The plasma triacylglycerol secretion rate was restored to normal by carnitine supplementation in semistarved rats. Urinary excretion of ketone bodies was reduced significantly after carnitine supplementation. We concluded that supplementation of carnitine can significantly increase the concentration of plasma free carnitine and improve lipid metabolism in semistarved rats fed a high-fat diet.
Animals↗
Tuberous sclerosis: immunohistochemistry expression of tuberin and hamartin in a 31-week gestational fetus.
Tuberous sclerosis complex (TSC) is a common autosomal dominant disorder in which affected patients develop a wide variety of benign and malignant tumors. We report here on a 31-week gestational age fetus with pathological features of TSC. Developmental expression of hamartin and tuberin in various tissues was studied using immunohistochemistry. There was loss of expression of hamartin in the tuber and weak expression of the tuberin. Both hamartin and tuberin were expressed in bronchial epithelial cells, cardiac muscles, renal collecting tubules, and neural tissues. The rhabdomyomas stained negatively for tuberin and hamartin. Two genetic loci are responsible for TSC-TSCI and TSC2. The TSC1 gene on chromosome 9 encodes a protein termed hamartin that lacks sequence similarity to any known proteins, whereas the TSC2 gene on chromosome 16 codes for a protein termed tuberin. These results indicate that tuberin and hamartin may play a critical role in development and thus provide a framework for understanding the developmental and hamartomatous manifestations of tuberous sclerosis.
Brain↗
The effects on fetal brain development in the rat of a severely iodine deficient diet derived from an endemic area: observations on the first generation.
Rats were fed on a severely iodine deficient diet (iodine content 4.5 micrograms/100 g) similar to that being consumed by people living in a village with a high rate of endemic cretinism. After a period of 4 months, the thyroid and brain were studied in the adult and their fetuses at 16, 17, 18, 19 and 20 days of gestation, and in postnatal animals at 1, 5, 10, 20, 30 and 60 days of age. By comparison with a control group (diet with iodine content 54.7 micrograms/100 g) the experimental group showed marked goitres, a higher uptake of 125I by the thyroid, reduced serum T4, and reduction in brain weight. The cerebral and cerebellar histological findings showed that the density of brain cells had increased, and the mean neuron size was reduced. Furthermore, disappearance of the cerebellar EGL was delayed. These findings indicate that this animal model is likely to be suitable for the studies of endemic cretinism in man.
Animals↗
Cytokines and cell surface markers in prediction of cardiac allograft rejection.
Endomyocardial biopsy is generally used to quantify heart allograft rejection and guide immunotherapy. Biopsy, however, is invasive, costly, and risky. Since rejection requires lymphocyte activation, the purpose of this study was to assess alternative methods to evaluate rejection dynamics by investigating serum levels of cytokines and cell surface markers after heart transplantation. Interleukin-2-receptor bearing CD4+T (IL-2R/CD4) cell levels were higher in the peripheral blood of human transplant recipients with rejection grade 2 (p < 0.02). HLA-DR/CD3 levels were somewhat higher in rejection grade 2. There was no correlation between biopsy scores and serum levels of tumor necrosis factor (TNF-alpha), IL-2, or percentage of T cell, NK cell, B cell, CD4+T cell, CD8+T cell, HLA-DR/CD4, HLA-DR/CD8, IL-2R/CD3, IL-2R/CD8. Interleukin-1 (IL-1 beta) was not detectable in all of the samples. The current studies suggest that monitoring lymphocyte IL-2R/CD4 and HLA-DR/CD3 levels is useful in predicting cardiac transplant rejection.
Adult↗
Unusual cardiac malformations in Holt-Oram syndrome: report of two cases.
The Holt-Oram syndrome is a hereditary disease which associated with upper limbs anomalies and cardiac defects such as secundum type atrial septal defect. Two cases of this syndrome with unusual cardiac findings are reported: One has an unroofing coronary sinus type atrial septal defect and preexcitation syndrome, the other has pentalogy of Fallot.
Abnormalities, Multiple↗