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Biomedical subjects

X Yao

Publications and source records attributed to X Yao.

At least 163 records · Page 9Linked to original sources

[Effect of tetrandrine on pulmonary hypertension induced by monocrotaline in rats].

The effects of Tetrandrine (Tet) on intraacinous pulmonary arteries (IAPA) and bemodynamics were studied by means of a rat pulmonary hypertension model induced by monocrotaline. The results showed that Tet could reduce the contractive pressure of pulmonary artery, right ventricle and right atrium of heart by 28.0%, 28.3%, and 31.5% respectively. It could also decrease the vascular degeneration of endoepithelial cells of IAPA, the endoepithelial subcavity, the collagens of medial membrane and the numbers of smooth muscles of IAPA.

Alkaloids↗

Expression of Na+,K(+)-ATPase alpha 1 subunit mRNA in the developing rat cochlea.

The distribution of Na+,K(+)-ATPase alpha 1 subunit mRNA was identified using in situ hybridization in the developing rat cochlea. The expression of alpha 1 subunit mRNA in stria vascularis (SV) was observed in all time points studied, 1 to 30 postnatal day (pnd) rats. The adult expression level was attained between 11 to 14 pnd. Surprisingly, alpha 1 subunit mRNA in spiral ligament (SL) and spiral limbus (SLi) was expressed in a more distinct time-dependent manner. At 7 pnd, the alpha 1 subunit mRNA expression was observed initially in the tissues of the SL. At 11 pnd, alpha 1 subunit expression appeared in SLi. Between 11 and 14 pnd, an adult-like pattern of Na+,K(+)-ATPase alpha 1 subunit mRNA expression was attained in the SL and SLi. These data suggest that the expression of Na+,K(+)-ATPase alpha 1 subunit mRNA in these areas are closely related to the development of the rat EP, as its expression in the stria vascularis.

Animals↗

Direct measurement of extracellular proton flux from isolated gastric glands.

We used the microphysiometer, a sensitive extracellular pH sensor, to resolve luminal (or apical) H+ secretion and basolateral release of OH- as well as liberation of acidic metabolites in rabbit gastric glands. Stimulation of glands via the adenosine 3',5'-cyclic monophosphate pathway produced a biphasic change in the extracellular acidification rate (EAR): after an initial transient decrease below the unstimulated baseline (-40.9 +/- 3.4%), the EAR increased to a steady-state maximal plateau (+98.1 +/- 5.3%) within 30 min (n = 37). We interpret the biphasic EAR profile as an initial excess of basolaterally released OH- followed by delayed luminal efflux of simultaneously produced H+. The elevated EAR at steady state reflected liberation of metabolic acid attributed to H(+)-K(+)-ATPase enzymatic activity. The presence of H2-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid prevented OH- release and reduced steady-state EAR. Basolateral OH- release and steady-state EAR were also inhibited by the H(+)-K(+)-ATPase inactivators omeprazole and SCH-28080. Inhibition of Na+/H+ exchange did not reduce steady-state EAR and did not affect apical H+ production, as judged by the accumulation of the weak base aminopyrine. Sodium thiocyanate (1 mM), which short circuits intraluminal H+ accumulation, blocked OH- release, demonstrating its dependence on H(+)-OH- separation at the apical membrane. A computerized model was developed to illustrate how the observed biphasic EAR profile would result from a delayed luminal efflux of H+ due to transitory intraluminal compartmentalization.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

Further studies on new furostanol saponins from the bulbs of Allium macrostemon.

Further studies by means of preparative HPLC led to the isolation of two new furostanol saponins, macrostemonoside J (1) and L (3), along with an artifact, macrostemonoside K (2) from the bulbs of Allium macrostemon. On the basis of chemical evidence and spectral analysis (1H-, 13C-NMR and FAB-MS), the structure of 1 was elucidated to be 26-O-beta-D-glucopyranosyl 2 beta,3 beta,22,26-tetrahydroxy-25(R)-5 beta-furostan 3-O-beta-D-glucopyranosyl (1-->2)-beta-D-galactopyranoside. 3 was deduced to be 26-O-beta-D-glucopyranosyl 2 beta,3 beta,26-trihydroxy-25(R)-5 beta-furostan- 20(22)-ene 3-O-beta-D-glucopyranosyl (1-->2)-beta-D-galactopyranoside.

Allium↗

Rehabilitative effect of music therapy for residual schizophrenia. A one-month randomised controlled trial in Shanghai.

Seventy-six in-patients who had the residual subtype of schizophrenia were randomly assigned to a treatment group or a control group. Both groups received standard medication as prescribed by their treating physicians, but the treatment group also received a one-month course of music therapy that included both passive listening to music and active participation in the singing of popular songs with other patients. Outcome was evaluated by four nurses using Chinese versions of the Scale for Assessment of Negative Symptoms and the in-patient version of the World Health Organization's Disability Assessment Scale. Music therapy significantly diminished patients' negative symptoms, increased their ability to converse with others, reduced their social isolation, and increased their level of interest in external events. As music therapy has no side-effects and is relatively inexpensive, it merits further evaluation and wider application.

Adolescent↗

Tumor-necrosis factor can enhance radio-antibody uptake in human colon carcinoma xenografts by increasing vascular permeability.

Marked differences in the tumor uptake of a 125I-labeled monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA) were observed in 4 serially transplanted human colorectal carcinomas in nude mice. A comparative study showed that elevated values of measurable tumor vascular parameters, such as permeability, blood flow and blood volume, correlated better with high MAb tumor uptake than the concentration of target antigen in the tumor. In an attempt to modify the vascular parameters and to determine if this could increase antibody uptake by the tumor, rhTNF alpha (TNF) was injected i.t. or i.v. and antibody localization experiments were performed immediately thereafter. Results showed that the permeability of the tumor vessels increased 8 to 10 fold 1 hr after i.t. injection of TNF as compared to control tumors injected with saline. Tumor uptake of 125I-labeled anti-CEA MAb, was 3 times higher 2 hr after i.v. injection and still 27% higher 22 hr later, as compared to results from controls. Intravenous injection of TNF simultaneously with the 125I-labeled anti-CEA MAb also resulted in a 2-fold increase in tumor uptake 4 hr after injection, but the increase was no longer significant 24 hr after injection. Interestingly after i.v. injection of TNF, the MAb concentration in the blood and other normal tissues, such as liver, kidneys, lungs and heart was decreased, resulting in significantly higher ratios of tumor to normal tissue. Taken together the results demonstrate that injection of TNF can increase tumor vascular permeability and improve radio-antibody uptake. This raises the possibility of increasing the radiation dose delivered by antibody to the tumor in the course of radioimmunotherapy.

Animals↗

Evolutionary artificial neural networks.

Evolutionary artificial neural networks (EANNs) can be considered as a combination of artificial neural networks (ANNs) and evolutionary search procedures such as genetic algorithms (GAs). This paper distinguishes among three levels of evolution in EANNs, i.e. the evolution of connection weights, architectures and learning rules. It first reviews each kind of evolution in detail and then analyses major issues related to each kind of evolution. It is shown in the paper that although there is a lot of work on the evolution of connection weights and architectures, research on the evolution of learning rules is still in its early stages. Interactions among different levels of evolution are far from being understood. It is argued in the paper that the evolution of learning rules and its interactions with other levels of evolution play a vital role in EANNs.

Algorithms↗

Ezrin-calpain I interactions in gastric parietal cells.

Gastric ezrin, a membrane-cytoskeletal linker with sequence homology to talin and erythrocyte band 4.1, has been associated with the remodeling of parietal cell apical membrane that occurs with adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase stimulation. Here we examine the interrelationship between parietal cell ezrin and Ca(2+)-dependent protease activity. Addition of Ca2+ to sonicated gastric gland preparations rendered a relatively selective proteolysis of the 80-kDa ezrin, accompanied by the appearance of a 55-kDa breakdown product. Ca(2+)-dependent proteolysis of ezrin was blocked by E64, a cysteine protease inhibitor, or calpastatin, indicating calpain as the responsible protease. Degradation of ezrin in intact gastric glands was achieved by varying extracellular [Ca2+] and [ionomycin]. Ezrin degradation in situ was rapid and relatively selective, although Ca(2+)-dependent degradation of some spectrin-like bands was also observed. The effect of activated calpain I on parietal cell function was assessed by probing the secretory response to histamine stimulation using [14C]aminopyrine uptake, along with parallel measurements of calpain activity, over a wide range of ionomycin. Activation of calpain, as evidenced by loss of parietal cell ezrin, was correlated with decreased AP uptake by stimulated gastric glands, supporting a role for ezrin in the oxyntic secretory process. The calpain-ezrin interaction established here, and the similarities of calpain with talin and erythrocyte band 4.1, suggest a common feature to this family of ezrin/band 4.1/talin proteins that have been implicated in membrane-cytoskeletal association.

Animals↗

[The study of the RFLP of D14S13 site of human genome].

The single-locus probe pCE 1.2 recognizes the D14S13 site in human genome. Allele-frequency of HaeIII digested D14S13 site is drawn out from 269 unrelated individuals. It displayed that there were at least 66 alleles and more than 93% heterogeneity. No mutation in 93 individuals of 8 families was observed. This RFLP technique has been applied in the identification and parentage testing in forensic science, and the accuracy of identity was calculated. Some further applications were discussed.

Alleles↗

Clinical observation on treatment of bradyarrhythmia with Chinese herbal medicine.

This paper reports on treatment of 62 cases of bradyarrhythmia with Fu Ben Zeng Mai Tang, a decoction of herbal medicine which has the effect of warming and tonifying the heart and kidney, reinforcing qi and improving blood circulation. The result indicates that it is effective for quickening the heart rhythm, improving the symptoms and regulating the function of sinoatrial node. It is also good for regulating the function of endocrine and the immune and nervous system. This therapy was compared with Western medicine in the treatment of 24 cases.

Adult↗

[Relationship between location and nipple discharge of breast cancer and its clinical significance].

The relationship between the location and the discharge of breast cancers in 50 cases was analyzed from May 1980 to May 1989. Those lesions were located beneath the areolae or near the areolae. Ductograms and cytology were very useful in the diagnosis. Most of them (72.7% and 69.2% respectively) belonged stage I. Five-year survival was 100% and 92.6% respectively. But those located far away from areola tended to become bigger and bigger, and invaded the large ducts. So the nipple discharge appeared. Most of them (69.2%) were in stage III. Five-year survival was 52.8%. The prognosis of this group was poorer than that of the former group.

Adult↗

[Prognostic significance of nuclear DNA measurement with flow cytometry for laryngeal squamous cell carcinomas].

DNA ploidy, S% and proliferative index (PI) of carcinomatous cell were evaluated with FCM in 41 patients with laryngeal primary squamous cell carcinomas which were operated on in our department during the period between Jan. 1979 to Oct. 1987. The results showed that DNA aneuploidy was identified in 65.85% of the cases (27/41) and patients with aneuploid carcinomas had higher S% (mean +/- standard: 23.22 +/- 9.57%), higher PI (mean +/- standard: 37.59 +/- 9.57%) and higher rate of relapse and/or metastasis than those with diploid tumours (55.55% vs 11.77%, P < 0.025). Patients with aneuploid carcinomas also correlated with an unfavorable prognosis compared with those with diploid tumors. Cases with aneuploid and diploid carcinomas had 66.11% and 92.86% respectively for two years postoperation survival rate; 46.74% and 92.86% respectively for five years postoperation survival rate (Log-rank test: chi 2 = 5.96, P < 0.025). We conclude that nuclear DNA measurement with flow cytometry is of important significance in estimating prognosis and guiding treatment for laryngeal squamous cell carcinomas.

Aged↗

Surgical approaches for improving the operating results of primary liver cancer.

The purpose of this study was to retrospectively analyse the results of 1102 primary liver cancer (PLC) patients who underwent liver resection in the past thirty years and to research some effective approaches for improving the longterm effect of PLC treatment. Ninety five percent were hepatocellular carcinoma (HCC), 85.2% with cirrhosis of hepatitis and 25.6% with tumor equal to or smaller than 5 cm in diameter. The mortality rate (MR) within 1 month after operation was 1.8%, the operative MR was 8.8% before 1977 and only 0.4% after that. The total 5-year survival rate (SR) was 28.4% while in the group of small tumor (less than or equal to 5 cm), it was 75.0%. Our experience is as follows: (1) Early diagnosis and early resection of PLC is the key point for improving the operative result of long-term survival. In 282 cases of small cancer, tumor resection rate was 90.0%. Of 48 cases with tumor equal to or smaller than 3 cm in diameter, the 5-year SR was 83.3%. (2) Rehepatectomy for recurrent liver cancer is an important approach for improving the surgical result. In our series, recurrent rate within 5 years postoperation was 72.3% in larger tumor group and 34.5% in small tumors. There were 78 cases undergoing reoperation in a total number of 170 times of rehepatectomy with 54.7% of 5-year SR, after the 1st operation and 34.6% after the 2nd one. (3) For unresectable large tumors, two-stage operation is an important development in liver surgery. We had 26 cases of such patients with 60.0% of 5-year SR. (4) Improvement of operating techniques plays an important role in reducing postoperative complications, lowering operative mortality and obtaining better operative result. (5) Postoperative comprehensive treatment is also important for solidating operative effect and preventing tumor recurrence.

Carcinoma, Hepatocellular↗

[Estrogen and progesterone receptors in laryngeal carcinoma].

The existence of hormone receptors on or within neoplastic tissue has potential diagnostic, therapeutic, and prognostic importance. It has now been demonstrated in many reports that cancers of the breast and prostate often express hormone receptors and can be controlled by hormone manipulation. The fact that larynx is a target organ for androgenic steroids has long been known. The question of whether laryngeal carcinoma expresses hormone receptors has been a matter of interest. We adopted the fluorescent hormone conjugate method to measure the estrogen receptor (ER) and progesterone receptor (PR) in 25 patients with laryngeal cancer. Our findings indicated that in 25 samples of laryngeal cancer 48% were ER positive, and 68% were PR positive. Cells of the laryngeal cancer not only contain ER and PR but also have relationship between the presence of receptors and the degree of histologic differentiation. Low differentiated cancers are inclinable to contain low level receptors. From this initial survey it appears that the hormone receptors could play an important role in the cancer of larynx. The presence of receptors in some laryngeal carcinoma implicates that these tumors are possibly hormone sensitive.

Adult↗