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Biomedical subjects

F Zhao

Publications and source records attributed to F Zhao.

At least 145 records · Page 8Linked to original sources
PubMed1994

A new functional classification of stomach cancer and its pathobiological and clinical significance.

The functional differentiations of stomach cancer specimens from 121 patients were investigated by enzyme-, mucin-, affinity- and immunohistochemical methods, and the stomach cancers were divided into five functionally differentiated types: 1) Absorptive Function Differentiation Type (AFDT), 19.8%; 2) Mucin Secreting Function Differentiation Type (MSFDT), 24.0%; 3) Absorptive and Mucin-Producing Function Differentiation Type (AMPFDT), 47.1%; 4) Special Function Differentiation Type (SFDT), 0.8%; and 5) Non-Function Differentiation Type (NFDT), 8.3%. The results indicate that stomach cancer tissues of the same histological type often display differing functional differentiation, and these functionally differentiated types have different invasive and metastatic characteristics. In addition, the functionally differentiated types have particular organic affinities of metastasis and different clinical prognoses. This study suggests that this new functional classification may supplement histological classification. The mechanisms of liver and ovary metastases of stomach cancer are also discussed.

Adenocarcinoma↗
PubMed1993

Iron-thiolate induced oxidation of methionine to methionine sulfoxide in small model peptides. Intramolecular catalysis by histidine.

Peptides containing either glycine and methionine, or glycine, methionine and histidine at various locations were oxidized by the dithiothreitol/ferric chloride system in phosphate buffer. The yields of peptide degradation and sulfoxide formation were measured as a function of peptide sequence and pH. In general little change of the final yields of peptide degradation is observed whereas the final yields of sulfoxide formation progressively decrease on going from pH 6.0 to 8.0. The pH profiles vary with the structure of the respective peptide. Efficient sulfoxide formation occurred when histidine and methionine were present within the same peptides sequence, and particularly when methionine was located at the C-terminus of the peptide. Added superoxide dismutase, catalase, and methanol did neither promote nor inhibit both the degradation of peptide and the formation of sulfoxide excluding free superoxide, hydrogen peroxide, and hydroxyl radicals as responsible reactive oxygen species. The observations are rationalized by invoking a pH-dependent conversion of an efficiently sulfoxide yielding oxidant into another oxidant which still degrades peptides but does not form methionine sulfoxide. The first might be a metal-bound peroxide or peroxyl species which converts into a metal-bound or 'complexed' hydroxyl radical.

Amino Acid Sequence↗
PubMed1993

Evidence from the anti-idiotypic network that the acetylcholine receptor is a rabies virus receptor.

We have developed idiotype-anti-idiotype monoclonal antibodies that provide evidence for rabies virus binding to the acetylcholine receptor (AChR). Hybridoma cell lines 7.12 and 7.25 resulted after fusion of NS-1 myeloma cells with spleen cells from a BALB/c mouse immunized with rabies virus strain CVS. Antibody 7.12 reacted with viral glycoprotein and neutralized virus infectivity in vivo. It also neutralized infectivity in vitro when PC12 cells, which express neuronal AChR, but not CER cells or neuroblastoma cells (clone N18), which have no AChR, were used. Antibody 7.25 reacted with nucleocapsid protein. Anti-idiotypic monoclonal antibody B9 was produced from fusion of NS-1 cells with spleen cells from a mouse immunized with 7.12 Fab. In an enzyme-linked immunosorbent assay and immunoprecipitation, B9 reacted with 7.12, polyclonal rabies virus immune dog serum, and purified AChR. The binding of B9 to 7.12 and immune dog serum was inhibited by AChR. B9 also inhibited the binding of 7.12 to rabies virus both in vitro and in vivo. Indirect immunofluorescence revealed that B9 reacted at neuromuscular junctions of mouse tissue. B9 also reacted in indirect immunofluorescence with distinct neurons in mouse and monkey brain tissue as well as with PC12 cells. B9 staining of neuronal elements in brain tissue of rabies virus-infected mice was greatly reduced. Rabies virus inhibited the binding of B9 to PC12 cells. Mice immunized with B9 developed low-titer rabies virus-neutralizing antibody. These mice were protected from lethal intramuscular rabies virus challenge. In contrast, anti-idiotypic antibody raised against nucleocapsid antibody 7.25 did not react with AChR.

Animals↗
PubMed1992

[Influence of 5.7-dihydroxytryptamine on electro-acupuncture analgesia and substance P level in central nervous system of the arthralgic rats].

The relation between electroacupuncture (EA) analgesia (A) and substance P (SP) level in the brain stem (BS) and lumbar spinal cord (LSC) of arthralgic rats was investigated. The rats were divided into three groups: 1)5.7-dihydroxytryptamine (5.7-DHT) + EA, 2) vehicle (V) + EA, and 3)5.7-DHT. All the animals were induced arthralgesia by injecting Freund's adjuvant 7 days after cisterna injection of 5.7-DHT or vehicle. The SP level in the BS and LSC was determined by RIA. The results indicated that in V + EA group the EA could prolong tail flick latency by 39.6%, but in other two groups did not. The SP level in LSC of V + EA group (179.1 +/- 11.5 pmol/g) was higher than that in the 5.7-DHT + EA (135.9 +/- 9.3pmol/g) and 5.7-DHT (125.8 +/- 10.0 pmol/g) groups. It suggested that both EA and arthralgia could activate the descending 5-HTergic inhibitory system to inhibit the release of SP in LSC. When the 5-HTergic system was destroyed by 5.7-DHT, the EAA was attenuated, and the SP level in LSC was lowered due to its release was decreased by EA and arthralgia.

Acupuncture Analgesia↗
PubMed1992

[Effect electroacupuncture on the neurogenic inflammation].

The neurogenic inflammation caused by antidromic stimulation of the saphenous nerve was taken as an index of peripheral release of substance P. Electroacupuncture could reduce the plasma extravasation from the neurogenic inflammation by 69.7%, but electroacupuncture per se did not cause obvious plasma extravasation. In rats pretreated with capsaicin the plasma extravasation could be markedly reduced, in consistent with the reduction of substance P-like immunoreactivity in dorsal horn. It is referred that electroacupuncture might block the conveying the signals induced by nerve stimulation along the C-fibers and the axo-axonal reflex, leading to the reduction of peripheral release of substance P. Besides the mediation by different central structures, acupuncture might have direct effects on regulating peripherally the release of some inflammatory and painful mediators.

Animals↗
PubMed1990

Effects of D-timolol and L-timolol on ocular blood flow and intraocular pressure.

Effects of D-timolol and L-timolol on IOP were compared with two rabbit models. When the drug solution was injected into vortex vein, 1% D-timolol produced ocular hypotension just like 0.5% L-timolol except D-timolol was less potent than L-timolol to lower the IOP. On the other hand, when 0.5% of D-timolol and L-timolol were instilled into the rabbit eye on IOP recovery model both agents showed equipotency to delayed the IOP recovery. Effects of D-timolol and L-timolol on ocular blood flow were also studied with two rabbit models. D-Timolol at 0.5% did not affect the ocular pulsatile blood flow measured with Langham's pneumatonometer whereas 0.5% L-timolol significantly suppressed it. D-Timolol (0.5%) was found to increase retinal and choroidal blood flows measured with laser Doppler method whereas L-timolol suppressed it. These results indicate that D-timolol though less potent than L-timolol to lower IOP, is superior over L-timolol to improve the blood flow in retina and choroid.

Administration, Topical↗
PubMed1990

[Effect of stress on spontaneously hypertension rats and mechanism of its action].

Social-psychological stress was closely related to psychosomatic diseases. Why could it cause the psychosomatic diseases and worsen some other diseases? No satisfied answer got yet. The blood pressure of SHR before and after laboratory stress were compared in this article and preliminarily studied the mechanisms of its action. It was found that stress state could expedite the onset of hypertension in SHR and worsened it continuously. After stress, the NE, E, and TC/HDL-C, TG all increased obviously. It indicated that social-psychological stress was closely related to essential hypertension.

Animals↗
PubMed1990

[Therapeutic effects of electroacupuncture (EA) on acute experimental arthritis in rats].

The dynamic changes of the pain thresholds (Heat-Withdrawal Latency, HWL and Stimulation-Vocalization Threshold, Voc) in the adjuvant-induced arthritic rats and the effects of EA on the pain thresholds, skin temperature and the circumference of the diseased ankle were observed. Both pain thresholds were obviously decreased in affected limbs in EA and control groups. But in the normal limbs, HWL decreased and Voc, no changed. In EA group, the ankle circumference and skin temperature were markedly lower than that in control group. The increase of the body weight was much more obvious than that in control group. Our experiment revealed that EA could not only increase the pain threshold, but also improve the pathological changes in the inflammation of the ankle, the mechanisms of the changes of the pain thresholds and the effects of EA in the arthritic rats were discussed.

Acupuncture Therapy↗
PubMed1989

Effects of D-timolol on intraocular pressure (IOP), beta blocking activity, and the dynamic changes of drug concentrations in aqueous humor.

L-timolol has been used successfully in the treatment of glaucoma. Because of its powerful beta blocking activity, however, more and more side effects have been reported. D-timolol, an optic isomer of L-timolol with much less beta blocking activity, was noted to have similar ocular hypotensive effects through inhibition of aqueous production as L-timolol. Thus, it is expected that D-timolol may reduce the side effects considerably if it is used in the clinics. In this study, we observed the ocular hypotensive effect of 0.5% D-timolol in normotensive and water-loaded rabbits as well as in patients with glaucoma or ocular hypertension. A significant reduction of intraocular pressure (IOP) which lasted at least six hours was observed. No side effects, either locally or systemically, were found. The concentration of D-timolol was traced in rabbits' aqueous humor after topical administration. The drug quickly appeared in the aqueous 30 minutes after instillation of 100 microliters 1% D-timolol. The peak concentration was 1916.5 ng/ml. It declined to a minimum in four hours, although the hypotensive effect could last at least six hours. For estimating the beta blocking potency of D-timolol, radioligand binding assay was employed to calculate the Ki value from isolated cell membrane of rabbits' lung. It showed that the beta blocking potency of D-timolol was much less than that obtained from L-timolol. It is concluded that D-timolol may be a valuable antiglaucoma agent comparable to L-timolol in lowering the IOP. The side effects induced by beta blocking agents we are using currently might be considerably reduced with D-timolol.

Adolescent↗
PubMed1989

[Primary study of histogenesis and diagnosis of synoviosarcoma].

Fourteen cases of synoviosarcoma were investigated by electron microscopy and immunohistochemical technique (PAP) using keratin and EMA as epithelial markers, vimentin as a mesenchymal marker. Of the 14 cases 9 were biphasic (BS) and 5 were monophasic synoviosarcoma (MS). In BS, epithelial-like cells, glandular, tubular of slit-like structures, junctional complex, microvilli at the luminar surface and basal lamellae at bottom could be easily seen. Spindle cells both in BS and MS were similar. These cells had somewhat similarity with epithelia-like cells, such as slender cell processes or microvilli, the external lamellae and cell junctions. The spindle cells also formed some slit-like structures. Collagenization was mild in matrix. Whether in BS or MS, epithelial or spindle cells, there were positive reactions for keratin, EMA and vimentin. The present study suggests that synoviosarcoma is neither a tumor of synovium origin nor a sarcoma of synovial differentiation, but a carcinosarcoma or adenosarcoma of soft tissues; the monophasic type is not a variant of fibrosarcoma either. It really is a distinct variant of synoviosarcoma. The expressions of both epithelial and mesenchymal features are useful criteria for diagnosis of synoviosarcoma.

Humans↗