Understanding the pathophysiology of stress urinary incontinence.
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Humans↗
Biomedical subjects
J Wei
Publications and source records attributed to J Wei.
Direct cDNA selection with DNA microdissected from mouse chromosome 16: isolation of novel clones and construction of a partial transcription map of the C3-C4 region.
A group of cDNA segments was selected by direct hybridization of mouse cerebellar cDNAs against genomic DNA pools generated by microdissection of the mouse chromosome 16 (MMU16) C3-C4 region. After elimination of repetitive sequences and adjustment for redundancy among clones, 34 novel cDNA fragments were isolated. The MMU16 origin of clones was confirmed by genetic linkage mapping. Reverse transcription PCR indicated that approximately 68% of the cDNAs represent transcripts that are expressed in adult mouse cerebellum. Northern blotting showed that some of these are predominantly or solely expressed in brain. This work demonstrates that DNA microdissected from banded MMU16 can be used for direct cDNA selection, thus enabling construction of a new, region-specific partial transcription map. This selected cDNA library should be a useful reagent for further molecular neurobiological studies.
Animals↗
Regulation of type I adenylyl cyclase by calmodulin kinase IV in vivo.
Type I adenylyl cyclase is a neurospecific enzyme that is stimulated by Ca2+ and calmodulin (CaM). This enzyme couples the Ca2+ and cyclic AMP (cAMP) regulatory systems in neurons, and it may play an important role for some forms of synaptic plasticity. Mutant mice lacking type I adenylyl cyclase show deficiencies in spatial memory and altered long-term potentiation (Z. Wu, S. A. Thomas, Z. Xia, E. C. Villacres, R. D. Palmiter, and D. R. Storm, Proc. Natl. Acad. Sci. USA 92:220-224, 1995). Although type I adenylyl cyclase is synergistically stimulated by Ca2+ and G-protein-coupled receptors in vivo, very little is known about mechanisms for inhibition of the enzyme. Here, we report that type I adenylyl cyclase is inhibited by CaM kinase IV in vivo. Expression of constitutively active or wild-type CaM kinase IV inhibited Ca2+ stimulation of adenylyl cyclase activity without affecting basal or forskolin-stimulated activity. Type I adenylyl cyclase has two CaM kinase IV consensus phosphorylation sequences near its CaM binding domain at Ser-545 and Ser-552. Conversion of either serine to alanine by mutagenesis abolished CaM kinase IV inhibition of adenylyl cyclase. This suggests that the activity of this enzyme may be directly inhibited by CaM kinase IV phosphorylation. Type VIII adenylyl cyclase, another enzyme stimulated by CaM, was not inhibited by CaM kinase II or IV. We propose that CaM kinase IV may function as a negative feedback regulator of type I adenylyl cyclase and that CaM kinases may regulate cAMP levels in some cells.
Adenylyl Cyclases↗
Changes in spectra of heart rate and blood pressure variabilities during bed rest and head-up tilt after bed rest.
Changes in the spectra of heart rate and systolic blood pressure variabilities (HRV and SBPV) were recorded during head-down bed rest and head-up tilt (HUT) in 15 healthy young men. After bed rest, five subjects failed to complete HUT test. During bed rest, the low-frequency (LF) and high-frequency (HF) powers of HRV and SBPV spectra were all significantly decreased, the ratio of low-frequency to high-frequency power of HRV spectrum (LF:HFHRV) increased on the 16th day. During the first 6min of HUT after bed rest, the heart rate was faster, but the LF:HFHRV and the LF power of SBPV spectrum in all subjects were similar to the data during HUT before bed rest. The diastolic and mean arterial pressure were significantly increased during HUT except in those who failed to complete the HUT test after bed rest. The results suggest that the peripheral vascular sympathetic activity and the cardiac parasympathetic activity are decreased with a relative increase in the cardiac sympathetic activity during bed rest, but the cardiovascular autonomic responsiveness during HUT after bed rest is basically preserved.
Adult↗
[Changes of brain potentials related to visual attention during simulated weightlessness].
To study the possible effect of simulated weightlessness on brain function state, the brain event-related potentials (ERPs) during a simple visual selective response task were compared between head down tilt (HDT) and head up tilt (HUT) in 9 normal subjects. The results were: both the target (T) and non-target (NT) flash signals induced significant slow positive potentials which were supposed to be related to the attention activity; the amplitude of the positive potentials in the frontal regions decreased significantly especially for NT-ERPs during HDT as compared with that during HUT. The data provide new evidence indicating that the ability of brain response declined during simulated weightlessness and more attention should be paid to the study of brain function during space flight.
Attention↗
Effect of 21 days head-down bed rest on heart rate and blood pressure variability and orthostatic tolerance in men.
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Adult↗
Rural population movement in China.
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Age Factors↗
Study of autoantibodies against the adenine nucleotide translocator in idiopathic dilated cardiomyopathy.
The frequency, dynamical change and effects of autoantibodies against the adenine nucleotide translocator (ANT) in idiopathic dilated cardiomyopathy (IDC) were studied. Sera of 16 patients with IDC showed significant binding capacity to the ANT protein (33.3%). Anti-ANT antibody titre was gradually tapered in approx. 2-3 months duration. However, anti-ANT antibody can inhibit the ADP/ATP exchange of heart mitochondria and be organ-specific. Short-term (6 weeks) treatment of 15 anti-ANT antibody-positive IDC patients with prednisone was of beneficial effect. Our results show that autoimmunity to the ANT can contribute to the pathogenesis and/or progression of IDC to a certain extent. But we must pay more attention to the fact that anti-ANT antibody characteristically exists short-term. Therefore, a short-term immunosuppressive treatment should be given to those IDC patients whose anti-ANT antibody is positive.
Adenosine Diphosphate↗
[The influence of electroacupuncture with different frequencies on the discharges of neurons in rostral ventromedial medulla on rats].
The experiments were carried out on rats, anesthetized with urethan and paralyed with tubocuraine. Stainless steel needles were inserted into bilateral "Zusanli" points. The unit discharges of RVM neurons were recorded extracellalarly by microelectrode. The searching of nociceptive neurons and processing of data were operated automatically by a real time control system. The results were as follow: 1. The pain response of excitatory neurons could be inhibited by 2 Hz EA (n = 15/22, P < 0.01), the mean inhibition rate was 32.40%. 2. The inhibitory effects of 2 Hz were completely blocked by naloxone pretreated (n = 5/5, P < 0.01). 3. The pain response of excitatory neurons could be inhibited by 10 Hz EA(n = 10/13, P < 0.01), the mean inhibition rate was 49.06%. 4. The inhibitory effects of 10 Hz EA were partially blocked by naloxone pretreated (n = 5/5, P < 0.01). 5. Both 2 Hz and 10 Hz EA could enhance the spontaneous discharges of excitatory neurons in RVM, and the percentage of change in the frequency was 62.45% and 112.02% respectively. 6. Neither 2 Hz nor 10 Hz EA could obviously influence the spontaneous activity of inhibitory neurons in RVM. The results suggest that both 2 Hz and 10 Hz EA could activate excitatory neurons in RVM, which may suppress nociceptive transmission via opioid mechanism.
Acupuncture Analgesia↗
Characterization of the nucleotide binding properties and ATPase activity of recombinant hamster BiP purified from bacteria.
HSP70 family proteins bind ATP and hydrolyze it, but the precise role of these activities in their in vivo chaperoning function has not been determined. In this report, we characterized wild-type hamster BiP isolated from bacteria in terms of its ATP binding and ATPase activities. Recombinant BiP behaved essentially the same as endogenous BiP in terms of oligomeric status, protease digestion patterns, and ATPase properties. By engineering a Factor Xa cleavable site following the His tag which was used for affinity purification, we demonstrated that the six histidines had no effect on either the structural or ATPase properties of recombinant BiP. We also found that bacteria-synthesized BiP had a tightly bound ADP that was resistant to dialysis. Removal of the bound nucleotide allowed us to directly measure the binding affinity of ATP and ADP to BiP (Kd of 0.2 microM for ATP and 0.29 microM for ADP) by equilibrium dialysis. Careful characterization of wild-type BiP will allow us to use this system to characterize BiP ATP binding site mutants that can be used to probe the role of ATP binding and ATPase activity in BiP functions.
Adenosine Triphosphatases↗
In vitro dissociation of BiP-peptide complexes requires a conformational change in BiP after ATP binding but does not require ATP hydrolysis.
In the present study, we produced single point mutations in the ATP binding site of hamster BiP, isolated recombinant proteins, and characterized them in terms of their affinity for ATP and ADP, their ability to undergo a conformational change upon nucleotide binding, and their rate of ATP hydrolysis. These analyses allowed us to classify the mutants into three groups: ATP hydrolysis (T229G), ATP binding (G226D, G227D), and ATP-induced conformation (T37G) mutants, and to test the role of these activities in the in vitro ATP-mediated release of proteins from BiP. All three classes of mutants were still able to bind peptide demonstrating that nucleotide is not involved in this function. Addition of ATP to either wild-type BiP or the T229G mutant caused the in vitro release of bound peptide, confirming that ATP hydrolysis is not required for protein release. ATP did not dissociate G226D, G227D, or T37G mutant BiP-peptide complexes, suggesting that ATP binding to BiP is not sufficient for the release of bound peptides, but that an ATP-induced conformational change in BiP is necessary. The identification of BiP mutants that are defective in each of these steps of ATP hydrolysis will allow the in vivo dissection of the role of nucleotide in BiP's activity.
Adenosine Diphosphate↗
[Analysis of relative factors on paralytic patients with pressure sore complications].
In this study, risk factors for bedsore were studied on 100 paralytic patients with neurologic diseases. The patient's assessment scores based on the risk factors for bedsore were evaluated and analyzed. According to the result, the critical point of assessment score for bedsore was established. The patient will be put into the high risk group of bedsore if his/her assessment score is higher than the critical point and special nursing intervention will be given.
Female↗
A poly(ethylene glycol) water-soluble conjugate of porin: refolding to the native state.
Porin, from Rhodabacter capsulatus, was chemically modified with methoxypoly(ethylene glycol) (m-PEG; molecular mass = 5000 Da) succinimidyl carbonate to yield methoxypoly(ethylene glycol)-porin (m-PEG-SC-Porin), as previously reported for bacteriorhodopsin [Sirokman, G., & Fasman, G. D. (1993) Protein Sci. 3, 1101-1170]. The m-poly(ethylene glycol)-porin (m-PEG-SC-Porin 50) conjugate, containing one poly(ethylene glycol) chain, was water soluble. The secondary structure of the conjugate in water was mainly random coil. Circular dichroism spectroscopy showed it was predominantly in the beta-pleated sheet structure in 0.6% octyltetraoxyethylene and 0.3 M LiCl, as was porin. A proteoliposome, containing the isolated porin conjugate, was prepared to measure permeability of the sugar stachyose. The m-PEG-SC-Porin 50 proteoliposome of porin maintained the permeability for the sugar, as did the proteoliposome of porin. The swelling rate of the conjugate versus the sugar was lower than it was for porin. This indicated that a pore in the conjugate exists but perhaps with a slightly different pore size. The refolding of the conjugate was studied by stepwise addition of trifluoroethanol (TFE) to lower the dielectric constant, simulating the insertion of porin into the membrane. An alpha-helical structure that did not exist in the native porin was formed with the m-PEG-SC-Porin 50, upon the addition of TFE, and the helicity increased with increasing concentrations of TFE. The m-PEG-SC-Porin 50 could be stepwise refolded to the native conformation, predominantly in the beta-sheet conformation, by the addition of hexafluoro-2-propanol in the 5-10% concentration range.(ABSTRACT TRUNCATED AT 250 WORDS)
Cell Membrane Permeability↗
Suppression of heat-induced hsp70 expression by the 70-kDa subunit of the human Ku autoantigen.
Expression of the 70-kDa polypeptide of human Ku autoantigen in rat cells is shown to suppress specifically the induction of hsp70 upon heat shock. Thermal induction of other heat shock proteins is not significantly affected, nor is the state of phosphorylation or the DNA-binding ability of the heat shock transcription factor HSF1. These findings support a model in which hsp70 gene expression is controlled by a second regulatory factor in addition to the positive activator HSF1. The Ku autoantigen, or a protein closely related to it, is likely to be involved in the regulation of hsp70 expression.
Animals↗
Nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester decreases ischemic damage in reversible focal cerebral ischemia in hyperglycemic rats.
We tested the hypothesis that the exacerbation of post-ischemic brain tissue injury associated with hyperglycemia in rats is due to toxic metabolism of nitric oxide. We used magnetic resonance imaging (MRI) techniques to measure neuronal and cerebrovascular injury in a 2-h transient focal cerebral ischemia model in normoglycemic and hyperglycemic rats at 3 and 24 h post-ischemia onset. We determined the effect of low dose (3 mg/kg i.p.) treatment with the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Compared to normoglycemia, preexisting hyperglycemia increased the volume of brain tissue exhibiting hyperintensity in diffusion weighted MRI (DWI) by factors of 5.6 and 6.2 at 3 h and 24 h post-ischemia, respectively. A similar increase in tissue volumes exhibiting hyperintense signal in T2-weighted MRI (T2WI) (3.3-fold and 5.6-fold) was observed. Cerebral blood volume MRI indicated a large focal no-reflow zone in hyperglycemic rats. Treatment with L-NAME eliminated the no-reflow zone in the hyperglycemic rats, and reduced tissue volumes of DWI hyperintensity by 86% and 93% at 3 h and 24 h, respectively. Similarly, tissue volumes of T2WI hyperintensity were reduced by 80% and 94% at 3 h and 24 h, respectively. Thus, nitric oxide is an important mediator in the exacerbation of post-ischemic brain injury in hyperglycemic rats. Inhibition of nitric oxide synthase limits edema formation, improves perfusion and reduces infarct volume.
Animals↗
Low concentrations of serum tyrosine in neuroleptic-free schizophrenics with an early onset.
The concentrations of serum tyrosine, phenylalanine and tryptophan have been determined in 23 male neuroleptic-free patients with schizophrenia and 28 male healthy control subjects. Tyrosine was significantly lower in neuroleptic-free patients with an early onset (starting before adulthood) than in healthy control subjects (p < 0.05), and the ratio of tyrosine to phenylalanine was significantly lower in neuroleptic-free patients with an early onset than in those with a late onset (starting at adulthood). No significant differences in these three amino acids were found between the patients with a late onset and healthy control subjects. The present findings suggest that there may be a disturbance of balance between tyrosine and phenylalanine in early-onset patients with schizophrenia.
Adult↗
Metabolic abnormalities following heart transplantation in patients with idiopathic cardiomyopathy.
The purpose of this study was to evaluate the risk factors for coronary artery disease associated with initiation of immunosuppressive therapy in patients with a pre-heart transplant diagnosis of idiopathic cardiomyopathy. This study was performed in 15 consecutive patients, mean +/- SEM age of 39 +/- 2 years, with a pre-operative diagnosis of idiopathic cardiomyopathy, who underwent cardiac transplantation at the Tri-Services General Hospital, Taipei, Taiwan, from July 1992 to June 1993. All patients were treated with cyclosporine, azathioprine and prednisolone, and the following measurements were performed prior to hospital discharge (mean +/- SEM) 36 +/- 3 days after successful transplantation: 1) fasting plasma lipid and lipoprotein concentrations; 2) plasma glucose and insulin concentrations in response to a 75 g oral glucose challenge; and 3) steady-state plasma insulin (SSPI) and glucose (SSPG) concentrations in response to a continuous infusion of somatostatin, insulin, and glucose. Since the SSPI concentrations are similar in all individuals, the SSPG concentrations provide an estimate of the ability of insulin to stimulate glucose disposal. Only six of the patients had a normal oral glucose tolerance test and the following diagnoses were found in the remaining nine patients: not diagnised (n = 3), impaired glucose tolerance (n = 4), and non-insulin-dependent diabetes (n = 2). Plasma lipid and lipoprotein concentrations were also frequently abnormal in the heart transplant patients; eight of the 15 patients had a plasma cholesterol > 5 mmol/l, nine had a high density lipoprotein (HDL)-cholesterol concentration < 1 mmol/l, and nine had a ratio of total to HDL-cholesterol > 5.0. Finally, the SSPG concentration was greater than 11.0 mmol/l in eight of the 15 patients, a value rarely exceeded in healthy volunteers. In conclusion, significant metabolic abnormalities were present at discharge in patients who had undergone successful cardiac transplantation for idiopathic cardiomyopathy. These metabolic abnormalities were probably caused by the use of immunosuppressive drugs. Given the magnitude of these changes, it would seem prudent to initiate therapeutic programs in patients with cardiac transplants that are not simply aimed at preventing rejection, but also address the metabolic abnormalities associated with the immunosuppressive agents used to prolong allograft survival.
Adult↗
Association of polymorphic VNTR region in the first intron of the human TH gene with disturbances of the catecholamine pathway in schizophrenia.
In the present study, five allelic fragments were typed by a polymerase chain reaction (PCR) process with a pair of primers specific for the tetranucleotide (TCAT) repeat sequence in the first intron of the human tyrosine hydroxylase (TH) gene and their sizes (bp) were 114 (A), 118 (B), 122 (C), 126 (D) and 130 (E), respectively. The AE genotypic frequency was found to be significantly higher in unrelated patients with schizophrenia than in unrelated control subjects (chi 2 = 4.18, p < 0.05). ANOVA revealed a significant difference between the three groups (neuroleptic-free patients possessing or not possessing the AE genotype, and unrelated control subjects) in the concentration of serum noradrenaline (F = 4.96, df = 2.79, p < 0.01), but no significant differences were found between the three groups in the concentrations of serum homovanillic acid, phenylalanine and tyrosine. These results suggest that the polymorphic intron 1 of the human TH gene may be associated with disturbances of the catecholamine pathway in schizophrenia.
Adult↗