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Biomedical subjects

Q Wu

Publications and source records attributed to Q Wu.

At least 343 records · Page 19Linked to original sources
PubMed1996

[A study of intraarticular irrigation-injection therapy of temporomandibular joint and its mechanism].

According to the research that there were some immune and inflammatory substances in the synovial fluid of temporomandibular joint disturbance syndrome (TMJDS), we improved the traditional intraarticular injection and developed an intraarticular irrigation-injection therapy to treat 43 cases of TMJDS and got a good result. The controls include two groups, the simple rinsing and the traditional injection. Statistical analysis showed a highly significant difference in the effects between test and control groups. In order to study the mechanism of the therapy, the tumor necrosis factor (TNF) in synovial fluid of 8 cases were assessed. It was found that the concentration of TNF was reduced markedly after treatment. We think that the new therapy is effectable for TMJDS and could be used widely.

Adult↗
PubMed1996

[Early results of CABG operation in 110 patients].

Coronary artery bypass grafting (CABG) operations were performed in 110 consecutive patients. Most of them had extensive triple-vessel disease or left main coronary artery disease. Internal mammary artery (IMA) was used as a graft in 65 patients. Valvular replacement or valvuloplasty were performed in 8 patients and ventricular aneurysmectomy in 10 patients including post infarction VSD repaired in 1 patient simultaneously. Angina pectoris was relieved in all patients except one died from acute renal failure postoperatively. The IMA could be used safely and efficiently in nearly all patients. Using very fine technique, we suggested good exposure, and hemostasis to handle IMA. The key factor of success in CABG operation was complete revascularization by passing all significant stenosis larger than 1 mm diameter in all coronary artery branches.

Adult↗
PubMed1996

[Surgical treatment of juxta-renal abdominal aortic occlusion: report of 27 cases].

Juxta-renal abdominal aortic occlusion is a relatively rare disease. We have treated 27 patients (25 males and 2 females) since 1984. Operations were performed on 25 patients, of whom 4 died and 84% improved. The main etiology was aorto-iliac stenosis or occlusion due to atherosclerosis and Takayasu's arteritis. Diagnostic basis included ischemia of lower limbs, pulselessness of abdominal aorta and both femoral arteries, sexual dysfunction, and positive result of angiography. Effective control of aorta below the left renal vein, aortotomy and retrograde endarterectomy were the main operative procedures. Axillo-bifemoral arterial bypass is recommended for patients associated with multiple diseases. The operative result is determined by associated diseases and the condition of run-off vessel. Associated diseases directly affect the mortality rate.

Adult↗
PubMed1996

[The sialographic characteristics of Warthin tumor in the parotid gland].

The sialograms of 80 cases with Warthin tumor in parotid gland were analysed. The sialographic characteristics were found as follows: irregular arrangement, dilation and narrow of branch ducts which surrounded the tumor, sausagelike change of main ducts just like that seen in obstructive parotitis, and spot-like dilation of the terminal ducts. The comparative study on roentgen-pathology showed that the spot-like dilation of the terminal ducts was related to the dilation of interlobular duct of the gland surrounding the tumor. The roentgen differential diagnosis of Warthin tumor from the aggressive benign tumor and Sjögren syndrome is discussed.

Adenolymphoma↗
PubMed1996

[Histochemical and electronic microscopical studies of stellate fibrillar formations (SFF) in salivary gland tumors].

PURPOSE: To study the structure and significance of SFF in pleomorphic adenoma and myoepithelioma. MATERIAL AND METHODS: Tow cases of each tumor were studied. Histologie and ultrathin sections were made, stained with HE, Mallory, Van Gieson, Pollak methods, and examined with light and transmission electronic microscopes. RESULTE: The SFF were proved to be formed by radial arrangement of collagen fibers, which were composed of striped fibrillae under TEM. CONCLUSION: The structure of the SFF is understood, their existence may play a role the pathologic diagnosis.

Adenoma, Pleomorphic↗
PubMed1996

[Long-term effects of CPAP in obstructive apnea syndrome].

OBJECTIVE: To study the long term effects with CPAP in OSAS. METHODS: Eighteen patients with OSAS were treated by CPAP at home for 3 to 27 months from 1987 to 1995, comparing the parameters of polysomnography (PSG) before and after treatment. RESULTS: (1) all the symptoms of OSAS were improved; (2) The parameters of PSG showed that the longest apnea duration from 66 +/- 21s to 43 +/- 24s (P < 0.05); AHI from 66 +/- 16 to 28 +/- 20 n/hour (P < 0.001); The lowest SaO2 from 53% +/- 19% to 75% +/- 11% (P < 0.001); (3) Comparing the body weight and blood pressure, no significant difference was shown before and after treatment with CPAP, but the blood pressure of 6 (50%) OSAS patients with hypertension had decreased to normal range. CONCLUSION: Long term treatment with CPAP in OSAS were effective, after which, the AHI, lowest level of hopoxemia, the longest apnea duration and the sympoms of OSAS were improved. The mechanism could be that the patents' breathing control were restored.

Adult↗
PubMed1996

[Effects of ding zhi pills on the scopolamine-induced impairment of passive avoidance in rats].

The Ding Zhi Pills described in "Thousand-Golden-Prescriptions" have better memory improving effect than those described in "Prescriptions People's Welfare Pharmacy". A combination of Poria, Radix Polygalae and Rhizoma Acori Graminei could enhance the pharmacologic effect of Radix Ginseng. Cinnabaris, described in "Prescriptions People's welfare Pharmacy", as one of the compositions in Ding Zhi Pills, does not improve the impairment of learning and memory, and therefore seems to have no meaning in the Ding Zhi Pills.

Animals↗
PubMed1995

Differences in backbone structure between angiotensin II agonists and type I antagonists.

Type I angiotensin II antagonists with O-methyl-L-homoserine [HSer(gamma-OMe)] and delta-methoxy-L-norvaline [Nva(delta-OMe)] at position 8 have been prepared by the solid-phase method, purified by reverse-phase HPLC, and bioassayed in the rat uterus, and their backbone conformational properties were investigated by nuclear Overhauser effect (NOE) spectroscopy. [Sar1,HSer-(gamma-OMe)8]ANGII, [HSer(gamma-OMe)8]ANGII, [Des1,HSer(gamma-OMe)8]ANGII, [Sar1,Nva(delta-OMe)8]-ANGII, and [Des1,Nva(delta-OMe)8]ANGII had, respectively, the following antagonist activities, pA2: 7.6, 7.5, < 6.0, 7.1, and 6.9. Analogs of [Sar1]ANGII with delta-hydroxy-L-norvaline [Nva(delta-OH)], delta-methoxy-L-norvaline [Nva(delta-OMe)], 4'-carboxyphenylalanine [Phe(4'-COOH)], and 4'-(trifluoromethyl)phenylalanine [Phe(4'-CF3)] at position 4 were also prepared by solid phase and bioassayed in the rat uterus. [Sar1,Nva(delta-OH)4]ANGII, [Aib1,Nva(delta-OMe)4]ANGII, [Sar1,DL-Phe(4'-COOH)4]ANGII, and [Sar1,DL-Phe(4'-CF3)4]ANGII had, respectively, agonist activities as follows: 4%, 1.5%, 3%, < 0.1%, and < 0.1%. These data emphasize that replacement of Ile8 in Sarilesin with the higher homologs HSer(gamma-OMe) and Nva(delta-OMe) does not greatly alter the structural requirements necessary for expression of type I antagonist activity, while replacement of the tyrosine hydroxyl in [Sar1]ANGII by the carboxylate or the trifluoromethyl group abolishes activity, suggesting that the tyrosinate pharmacophore cannot be replaced by any negatively charged or electronegative group. Conformational investigation of the ANGII type I antagonists [HSer(gamma-OMe)8]ANGII and [Sar1Nva(delta-OMe)8]ANGII in DMSO by 1D-NOE spectroscopy revealed that the Tyr-Ile-His bend, a conformational property found in ANGII and [Sar1]ANGII (J. Biol. Chem. 1994, 269, 5303) is not present in type I antagonists, providing for the first time an important conformational difference between angiotensin II agonists and type I antagonists.

Amino Acid Sequence↗
PubMed1995

Characterization of cytochrome c variants with high-resolution FTICR mass spectrometry: correlation of fragmentation and structure.

The dissociation of cytochrome c ions (15+ charge state) generated by electrospray ionization has been studied by Fourier transform ion cyclotron resonance mass spectrometry (FTICR) using a sustained off-resonance irradiation/collision-induced dissociation (SORI-CID) technique. Over 95% of the fragment ions can be accurately assigned (to better than 10 ppm), yielding information on the primary sequences of the various proteins. Up to four stages of mass spectrometry (MS4) have been achieved without the need for quadrupole excitation/collisional cooling of the product ions. The subtle structural differences among the cytochrome c variants (from bovine, tuna, rabbit, and horse) are clearly reflected in their fragmentation patterns: replacing 3 out of 104 residues of the cytochrome c is shown to dramatically change the dissociation pattern. Of particular importance are a variety of results indicating that the dissociation of the cytochrome c's is influenced by higher-order structure and charge location, in addition to the primary structure (i.e., sequence). No fragmentation is observed in the region between residues 10-20 and little dissociation between residues 70-90. This is most likely due to the interactions of the heme group with the polypeptide chain, and such a heme "footprinting" pattern is analogous to the protein conformation in solution. These studies demonstrate that electrospray ionization-FTICR using SORI-CID can be a useful tool to probe not only the small differences in the primary sequences of proteins but also suggest the potential for probing their higher-order structures and yielding information not readily available from H/D exchange or circular dichoism studies.

Amino Acid Sequence↗
PubMed1995

The role of charge in polyamine analogue recognition.

A series of analogues and homologues of N1,N12-diethylspermine (DESPM) was synthesized, and their biological properties were evaluated. These tetraamines include a simple linear analogue of DESPM, N1,N12-bis(2,2,2-trifluoroethyl)spermine (FDESPM), the cyclic analogues of DESPM, N,N'-bis(4-piperidinylmethyl)-1,4-diaminobutane [PIP(4,4,4)] and N,N'-bis[2-(4-piperidinyl)ethyl]-1,4-diaminobutane [PIP(5,4,5)], and their aromatic counterparts, N,N'-bis-(4-pyridylmethyl)-1,4-diaminobutane [PYR(4,4,4)] and N,N'-bis[2-(4-pyridyl)ethyl]-1,4-diaminobutane [PYR(5,4,5)]. The analogues FDESPM, PIP(4,4,4), and PYR(4,4,4) have distances between their nitrogen atoms almost identical to those of DESPM. The longer analogues PIP(5,4,5) and PYR(5,4,5) are very similar in the spacing of their amino groups. However, the pKa of the nitrogens in the groups differ; thus, the extent of protonation and the charge characteristics among the members of the groups differ. A comparison of the biological properties of these compounds clearly demonstrates that the tetraamines must be charged to be "recognized" by the cell. Analogues with low nitrogen pKa's such that the nitrogens are poorly protonated at physiological pH do not compete well with spermidine for uptake and, as expected, have high 96 h IC50 values and have little effect on S-adenosylmethionine decarboxylase, ornithine decarboxylase, and spermidine/spermine N1-acetyltransferase activities and on intracellular polyamine pools.

Acetyltransferases↗
PubMed1995

Impact of polyamine analogues on the NMDA receptor.

Several N,N'-terminal dialkylated homologs of the tetraamine spermine exhibit a pronounced biphasic activity at the N-methyl-D-aspartate (NMDA) receptor-channel complex in rat cerebral cortex membranes in the presence of 100 microM L-glutamate and 100 microM glycine. At low micromolar polyamine concentrations, these analogs enhance binding of [3H]-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-im ine ([3H]MK-801) similar to spermine (SPM). At higher concentrations (e.g., > or = 10 microM), the analogs are antagonists of [3H]MK-801 binding. The most potent analog, N1,N14-bis(1-adamantyl)homospermine, is almost totally devoid of agonist activity and is a potent antagonist at concentrations > or = 5 microM. Three structural features of the tetraamines studied appear to correlate with potency of inhibition: (1) N-terminally alkylated polyamines > terminal primary amines (e.g., SPM); (2) length of the polyamine backbone, e.g., DMHSPM > DMNSPM; and (3) size of the terminal alkyl groups, i.e., adamantyl > tert-butyl > ethyl > methyl. These findings emphasize the potential of the tetraamine backbone as a pharmacophore to modulate NMDA receptor-channel function.

Animals↗
PubMed1995

Plasminogen activator inhibitor type 2: an intracellular keratinocyte differentiation product that is incorporated into the cornified envelope.

Human epidermal keratinocytes synthesize a complex plasminogen activator proteolytic cascade, consisting of two plasminogen activating enzymes and two inhibitors, that is thought to play a role in epidermal migration and differentiation as well as in several cutaneous diseases. Quantification of the plasminogen activator cascade proteins in keratinocytes reveals that plasminogen activator inhibitor type 2 (PAI-2) is distinct from the other components (i.e., urokinase and tissue-type plasminogen activators and inhibitor type 1) in several respects: (i) PAI-2 remains mostly cell-associated, rather than secreted; (ii) The level of cell-associated PAI-2 is at least 50-fold greater than that of the other components; (iii) PAI-2 is the only component whose level is enhanced upon elevation of the Ca2+ concentration, which is well known to induce a more differentiated phenotype in keratinocyte culture. Immunocytochemical localization experiments reveal that most keratinocytes contain PAI-2, which in a subpopulation of more differentiated cells is resistant to detergent extraction. Additional immunocytochemical localization and immunoblot experiments demonstrate that some of the PAI-2 becomes incorporated into the cornified envelope during terminal differentiation of the keratinocyte. These studies raise the possibility that PAI-2 may have an intracellular role associated with the terminal stage of keratinocyte differentiation.

Cell Differentiation↗
PubMed1995

Light-dependent chlorophyll a biosynthesis upon chlL deletion in wild-type and photosystem I-less strains of the cyanobacterium Synechocystis sp. PCC 6803.

Part of the chlL gene encoding a component involved in light-independent protochlorophyllide reduction was deleted in wild type and in a photosystem I-less strain of Synechocystis sp. PCC 6803. In resulting mutants, chlorophyll biosynthesis was fully light-dependent. When these mutants were propagated under light-activated heterotrophic growth conditions (in darkness except for 15 min of weak light a day) for several weeks, essentially no chlorophyll was detectable but protochlorophyllide accumulated. Upon return of the chlL- mutant cultures to continuous light, within the first 6 h chlorophyll was synthesized at the expense of protochlorophyllide at a rate independent of the presence of photosystem I. Chlorophyll biosynthesized during this time gave rise to a 685 nm fluorescence emission peak at 77 K in intact cells. This peak most likely originates from a component different from those known to be directly associated with photosystems II and I. Development of 695 and 725 nm peaks (indicative of intact photosystem II and photosystem I, respectively) required longer exposures to light. After 6 h of greening, the rate of chlorophyll synthesis slowed as protochlorophyllide was depleted. In the chlL- strain, greening occurred at the same rate at two different light intensities (5 and 50 microE m-2 s-1), indicating that also at low light intensity the amount of light is not rate-limiting for protochlorophyllide reduction. Thus, in this system the rate of chlorophyll biosynthesis is limited neither by biosynthesis of photosystems nor by the light-dependent protochlorophyllide reduction. We suggest the presence of a chlorophyll-binding 'chelator' protein (with 77 K fluorescence emission at 685 nm) that binds newly synthesized chlorophyll and that provides chlorophyll for newly synthesized photosynthetic reaction centers and antennae.

Bacterial Proteins↗