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Biomedical subjects

W Wu

Publications and source records attributed to W Wu.

At least 469 records · Page 26Linked to original sources
PubMed1991

[Effects of ibuprofen and OKY-046 on ventilation perfusion distribution in acute respiratory failure].

Hydrochloric acid was injected into the trachea to produce acute respiratory failure in 18 anesthetized dogs. Six dogs were pretreated with ibuprofen (12.5 mg/kg), six dogs were given OKY-046 (0.5 mg/kg), and the remaining six were taken as controls. Distribution of ventilation-perfusion was evaluated by inert gas elimination technique. Acid aspiration caused a prompt decline in PaO2 with an increased perfusion to shunt and low VA/Q lung regions. Pretreatment with ibuprofen reduced pulmonary blood flow to shunt and low VA/Q regions for the first 2 hours after acid aspiration and attenuated hypoxemia, causing an increase in PVR. However, OKY-046, a thromboxane synthetase inhibitor, did not ameliorate acid-induced VA/Q mismatching and hypoxemia.

Animals↗
PubMed1991

The investigation of antiepileptic action of qingyangshen (QYS)--effect of QYS on the concentrations of neuropeptides in rat brain.

The concentrations of central neuropeptides, somatostatin (SS) and substance-P (SP), were determined in the different brain regions of young-aged male rats after a long-term administration of anticonvulsants Qingyangshen (QYS), Diphenylhydantoin (DPH), and Carbamazepine (CBZ). The results were compared with Pentylenetetrazol (PTZ)-induced seizure model and normal saline-treated controls. No effects of QYS on the concentrations of SS and SP were found in the rats of four-week or eight-week group. Both of DPH and PTZ increased the SS levels in the midbrain of rats in four-week group. DPH, CBZ, and PTZ also increased the SP levels in the cerebral cortex, striatum, and brain stem of rats in eight-week group. Our present data indicated that the central neuropeptides SS and SP were involved in the processes of epilepsy and antiepilepsy. Since QYS did not influence the contents of SS and SP after a long-term administration, it suggested that the anticonvulsant mechanism of QYS may be different from those of DPH and CBZ, i.e. it may be not due to its effect on the central neuropeptide pathway.

Animals↗
PubMed1991

The effect of radix Salviae Miltiorrhizae (RSM) on substance P in cerebral ischemia--animal experiment.

The levels of substance P (SP) in rat brains were assayed in 64 rats. Bilateral common carotid artery ligation was done in 49 rats. Half an hour before ligation, 25 rats were given 10 g/kg of RSM; 24 rats were given the same volume of normal saline as controls. Sham operation was done in 15 rats. Half an hour and 3 hours after cerebral ischemia, the rats were quickly decapitated. SP concentration was assayed in the cerebral cortex, caudate nucleus and brain stem. In saline-treated animals, the SP level of caudate nucleus at 3-hour group was significantly decreased as compared with the 0.5-hour group and sham-operated group respectively. No significances were found among RSM-treated groups and sham-operated groups. The SP levels were shown: brain stem greater than caudate nucleus greater than cerebral cortex. The preliminary results suggest that SP may be involved in the pathophysiologic procedures of cerebral ischemia and RSM may attenuate the dysfunction of SP during cerebral ischemia.

Animals↗
PubMed1991

[Immunohistochemical localization of calcitonin gene-related peptide (CGRP) and neuropeptide Y (NPY) in the cochlea and middle ear of the guinea pig].

The avidin-biotin peroxidase complex immunostaining method combined with the glucose oxidase-nickel (ABC-GON) technique was applied to the guinea pig cochlea and middle ear, the fine structure of CGRP-containing fibers in the organ of Corti was also observed. The results demonstrated that the CGRP-containing fibers in the cochlea belonged to both the medial and lateral efferent systems of olivocochlear bundle. The CGRP positive nerve endings on outer hair cell base formed synaptic contacts with the cell body. No NPY-containing fibers were found in the cochlea. Numerous CGRP and NPY-containing fibers of a similar distribution pattern and density were seen in the middle ear mucosa. The pars tensa of ear drum was also innervated by moderate CGRP-containing fibers and a few NPY-containing fibers. Occasionally, the CGRP-containing fibers were observed along the radial fibers in the pars tensa. The role of two neuropeptides in the cochlea and middle ear are discussed.

Animals↗
PubMed1991

Crystal-induced inflammation: studies of the mechanism of crystal-membrane interactions.

Studies of the interactions of monosodium urate monohydrate (MSUM) crystals and calcium pyrophosphate dihydrate triclinic (CPPD) crystals with biomembranes have been reviewed. Crystal-membrane binding and crystal-induced membranolysis have been studied using human erythrocytes as a model membrane system. The extent of MSUM-membrane binding was determined by incorporating a hydrophobic, fluorescent probe into the membranes, centrifugation to separate free membranes from membranes with bound crystals and quantitation of free membranes by measuring the total fluorescence intensity. The ability of MSUM and CPPD to hemolyse red cells was used as a measure of the membranolytic potential of the crystals. Fluorescence polarization studies showed that MSUM-membrane binding resulted in fluidization of the membrane. Cross-linking of the membrane proteins of the erythrocyte or the presence of divalent cations in the incubation medium inhibited MSUM induced hemolysis. These findings were explained by hypothesizing a "pore" model mechanism for MSUM induced membranolysis as follows. Binding of crystals to membranes induces the redistribution of transmembrane proteins into clusters or aggregates leading to "pore" formation. The "pores" permit the leakage of low molecular weight soluble compounds and ions acoss the membrane which is followed by osmotic rupture of the membrane.

Arthritis↗
PubMed1990

"Dry lithotripsy" by a simple modification of the Chinese lithotripter KDE-1.

We report on the improved technique upon a water bath lithotripter. With a simple water balloon device added to the Chinese KDE-1 Type water bath lithotripter, an extracorporeal shock wave dry lithotripter has been developed. From June to December 1988, there were 300 cases of upper urinary tract calculi and gallbladder stone treated with this machine with excellent results and no severe complications. The improved technique would be made reference to change old water bath machines into dry (water balloon) machines.

Adult↗
PubMed1990

[Clinical and experimental study of wei-nin granules in the treatment of chronic superficial gastritis].

408 cases of chronic superficial gastritis diagnosed by fibergastroscopy and histology were treated with Wei-Nin granules (WNG), The symptomatic effective rate was 90.5%, while therapeutic effect proved by gastroscopy and histology was 81.9% and 72.8% respectively. These results compared with the control were statistically significant. In animal experiment, it is shown that WNG had an evident protective effect to the mucous membrane of rats and guinea pigs. These animals had suffered gastritis and gastric ulcer induced by drugs. The effect of WNG was similar to cimetidin. The pharmaceutical mechanism of WNG proved that it could inhibit the secretion of pepsin. The acute and chronic poisoning test was negative both in vitro and in vivo. WNG were nearly no any side effects in this study. Therefore it is a new type of herbs in treatment of chronic superficial gastritis and is different from H2-receptor inhibitor.

Adult↗
PubMed1989

Cohort and case-control analyses of workers exposed to vinyl chloride: an update.

The mortality in a cohort of workers at a vinyl chloride polymerization plant has been updated, extending the period of observation in the original study from 1974 to 1986. Workers at this plant may have been exposed to vinyl chloride monomer and/or polyvinyl chloride dust, or may have had no exposure to either substance. Seventy-six percent of the work force worked in jobs with potential exposure to vinyl chloride monomer. Among the total cohort, statistically significant excess risks were observed for liver, lung, and brain cancer. For the subcohort of workers exposed to vinyl chloride monomer, the standardized mortality ratio (SMR) for liver cancer was 333 (90% confidence interval (CI) 202 to 521). However, there were no significant excesses of either brain (SMR = 145, 90% CI 78 to 249) or lung cancer (SMR = 115, 90% CI 96 to 141). To investigate dose response, nested case-control studies for liver, brain, and lung cancer were conducted among the total cohort (including the nonexposed). For these studies there were two exposure variables, cumulative dose of vinyl chloride monomer and cumulative dose of polyvinyl chloride dust. Cumulative dose was defined as the product of level and duration of exposure. The only significant association between disease risk and cumulative dose was for liver cancer and cumulative dose of vinyl chloride monomer. Further division of the liver cancers into angiosarcoma (n = 12) and other liver cancers (n = 7), based on review of death certificates and medical records, showed that the dose response existed only for angiosarcomas.

Brain Neoplasms↗
PubMed1988

Spontaneous noncardiac chest pain. Evaluation by 24-hour ambulatory esophageal motility and pH monitoring.

Noncardiac chest pain can be a diagnostic dilemma because patients rarely experience spontaneous chest pain in the laboratory. Therefore, we studied 24 patients with chronic, daily, substernal chest pain with a prototype 24-h ambulatory esophageal motility and pH system. Spontaneous chest pain episodes were correlated with pH less than 4 and abnormal motility changes (mean amplitude and duration, maximum amplitude and duration, or percentage of abnormal peristalsis) defined as exceeding the patient's normal esophageal motility pattern. Twenty-two patients experienced a total of 92 spontaneous chest pain episodes. Eleven chest pain episodes (12%) occurred during abnormal motility, whereas 18 episodes (20%) were associated with pH less than 4 and four episodes (4%) had both abnormalities. The majority of chest pain episodes, 59 events (64%), did not have any association with motility or pH. Abnormal maximum duration and amplitude were the motility changes most frequently associated with chest pain. Overall, 13 of 22 patients (59%) had at least one chest pain episode correlating with abnormal motility or pH (range 33%-100%). Therefore, we conclude that ambulatory esophageal motility and pH monitoring is useful in the evaluation of noncardiac chest pain. pH abnormalities (20%) are more commonly associated with chest pain than motility abnormalities (12%). However, the majority of chest pain episodes (64%) did not correlate with either abnormality and may be the result of lowered esophageal pain threshold for distention, i.e., the "irritable esophagus."

Chest Pain↗
PubMed1986

Evidence that heme d1 is a 1,3-porphyrindione.

Heme d1 is the noncovalently associated heme prosthetic group of the bacterial nitrite reductase known as cytochrome cd1. Additional evidence has been obtained in support of a dioxoisobacteriochlorin, or 1,3-porphyrindione, skeleton for this heme. The new data include the natural abundance 13C NMR spectrum of the free base methyl ester derivative of d1, mass spectrometric determinations of the molecular mass of the free base methyl ester and the Cu and the Zn chelates, visible and 1H NMR spectral comparisons between d1 and synthetic porphyrindione model compounds, and the isolation and characterization of several byproducts formed during the purification of the free base methyl ester of d1. The accumulated evidence strongly supports the following structure for the skeleton of d1: 1-oxo-2-methyl-2'-acetyl-3-oxo-4-methyl-4'-acetyl-5-methyl-6-acrylyl+ ++-7- propionyl-8-methylporphyrin.

Bacteria↗
PubMed1986

The porphinedione structure of heme d1. Synthesis and spectral properties of model compounds of the prosthetic group of dissimilatory nitrite reductase.

In an attempt to verify the recent proposal that the heme d1 prosthetic group isolated from cytochrome cd1 is not a chlorin, but a dioxo-isobacteriochlorin (Chang, C. K. (1985) J. Biol. Chem. 260, 9520-9522), a model dioxo-isobacteriochlorin has been synthesized possessing a pi-electron system exactly identical to that as proposed. The presence of an acrylic acid substituent strongly perturbs the absorption spectrum of the chromophore and produces a visible spectrum virtually indistinguishable from that of the iron-free heme d1. Based on this finding, buttressed by additional spectral correspondence between the model iron heme and heme d1, we conclude that the proposed diketo ring structure is indeed correct, and the trivial names "dioneheme" and "acryloporphyrindione" are suggested for heme d1 and the demetallated macrocycle, respectively.

Heme↗