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Biomedical subjects

Z Cao

Publications and source records attributed to Z Cao.

At least 163 records · Page 9Linked to original sources
PubMed1997

Role of angiotensin II and bradykinin in experimental diabetic nephropathy. Functional and structural studies.

We explored the relative roles of the suppression of angiotensin II and the prevention of bradykinin degradation in mediating the renoprotective effects of ACE inhibitors in experimental diabetic nephropathy. Over a 24-week period, we studied male Sprague-Dawley diabetic and control rats and Sprague-Dawley diabetic rats treated with the ACE inhibitor ramipril, the angiotensin II-AT1 receptor antagonist valsartan, the bradykinin-B2 receptor antagonist HOE 140 (icatibant), and a combination of ramipril and icatibant. Serial measurements of urinary albumin excretion, blood pressure, and glycated hemoglobin were performed monthly. After 6 months, the animals were killed for the measurement of kidney weight and the assessment of glomerular ultrastructure. Over 24 weeks, urinary albumin excretion showed a continuous rise in the untreated diabetic rats. Both ramipril and valsartan, which were equihypotensive, prevented the increase in urinary albumin excretion over the whole study period. Icatibant therapy did not attenuate the antialbuminuric effect of the ACE inhibitor, nor did it have any effect as the sole therapy. Diabetes was associated with increased glomerular basement membrane thickness, glomerular volume, and total mesangial volume. Both ACE inhibition and angiotensin II receptor antagonism attenuated the glomerular ultrastructural changes to a similar degree. Icatibant did not attenuate the effects of ramipril on glomerular morphology. ACE inhibitors and angiotensin II-AT1 receptor blockers appear to confer similar benefits in experimental diabetic nephropathy, and bradykinin-B2 receptor blockers do not influence this effect. These findings suggest that the blockade of angiotensin II is the major pathway responsible for renoprotection afforded by ACE inhibition in experimental diabetic nephropathy.

Albuminuria↗
PubMed1997

[The inhibitory effect of hydroprednisolone on tumor necrosis factor in rabbits' temporomandibular joint disturbance syndrome].

In order to study the mechanism of hydroprednisolone for temporomandibular joint disturbance syndrome (TMJDS), 12 white rabbits were injected TNF into the rabbits' right TMJDS for 2 to 3 times, 90,000 u each time, then another drug, 2 mg hydroprednisolone, was injected into these TMJDS again. The rabbits were killed after 8 to 18 days and the TMJDS were examined by microscope. We found the articular tissues only destroyed slightly and sometimes the cartilages were nearly normal. So, the study suggested that hydroprednisolone can reduce the destruction of TNF on rabbit's TMJ obviously. This may be the cause why hydroprednisolone is useful to TMJDS.

Animals↗
PubMed1997

[The change of calcitonin gene-related peptide positive fibers in inflammatory pulps].

Deep cavities were prepared on rats' molars, and fresh carious dentin was enclosed in to establish animal pulpitis model. Immunohistochemical method was used to observe the distribution of calcitonin gene-related peptide (CGRP) positive nerve fibers in rats' normal dental pulps and inflammatory pulps at 4d, 8d, 14d respectively. CGRP positive fibers were found throughout the normal pulps, a large number of fibers penetrated into dentinal tubules. In 4d group, CGRP positive fibers became denser and the number of fibers penetrating into dentinal tubules also increased. In 8d group, a necrotic zone could be found in the coronal pulps, lots of fibers accumulated around the necrotic zone. In the radical pulps, CGRP positive fibers formed multiple arborizations. 14d postinflammation, all the pulps were necrotic, and the periapexs were richly innervated by CGRP positive fibers. The results suggesting that CGRP may play a role in the inflammation and repair of dental pulp.

Animals↗
PubMed1997

[Evaluation on ISGP classification of endometrial hyperplasia in clinical application].

To evaluate clinical application of International Society of Gynecologic Pathologists Classification of endometrial hyperplasia 424 patients with endome trial hyperplasia were treated in our hospital from Sept. 1989 to Feb. 1995. Our of these cases, 339 were simple hyperplasia, 28 were complex hyperplasia and 57 atypical hyperplasia. We made an analysis of the cases of complex and atypical hyperplasia in terms of the ISGP classification. The total rate of curettage was 63.5%. The agreement rate for pathologic diagnoses before and after operation was 78%. Under the age of 40, 18 patients had atypical hyperplasia and 15 of them underwent hysterectomy. Eight patients had complex hyperplasia and 3 of them underwent hysterectomy. Above the age of 40, 39 patients had atypical hyperplasia and 30 of them had uterus removed. Twenty patients had complex hyperplasia and 12 of them had uterus removed. These suggest that the ISGP pathologic diagnostic method is good to avoid overdiagnosis and overtreatment. Yet, diagnostic curettage is still the best means in diagnosis before operation.

Adult↗
PubMed1997

[Improvements of laryngectomy cricopharyngeal anastomosis laryngeal reconstruction (report of 27 cases)].

To alleviate the deglutition and increase decannulation rate in Arslan's operation, 27 patients who had undergone laryngectomy cricopharyngeal anastomosis reconstruction from 1989 to 1995 in our hospital were reported. There were T1bN0 8 cases, T2N0 17 cases, T3N0 2 cases according to UICC staging in 1987. All lesions located in vocale cords bilaterally. On the side of the mild lesion, over half of the vocale cord was invaded. The main points of surgical procedure were that the epiglottic and cricoid cartilage were restored. Hyoid bone and arytenoid cartilages were resected and cricoid cartilage anastomosis with the base of the tongue and submental muscles. Phonation was restored in all postoperative patients. Deglutition was alleviated significantly. Decannulation rate was 92.6% (25/27). The follow-up period of 14 cases was over 3 years. Of the 14 cases, 1 died. The 3 years survival rate was 92.86% (13/14). The follow-up period of 6 cases was over 5 years. Of the 6 cases, 1 was lost, the 5 years survival rate was 83.33% (5/6). The operation has great effects on alleviating deglutition and increasing decannulation rate.

Adult↗
PubMed1997

[Histopathological study of local invasion and cervical lymph node metastasis in transglottic carcinoma].

To study the histopathological characteristics of local invasion and cervical lymph node metastasis in transglottic carcinoma and provide theoretical guide to clinical practice, 30 laryngectomy and 35 neck dissection specimens were studied by serial section, HE staining and observation under light microscope. The results showed that transglottic carcinomas originated from the ventricle invaded supraglottic and glottic areas equally. The metastatic rate of cervical lymph nodes was 43.3%; the latent metastatic rate was 30%. The metastatic and extracapsular perforation rates as well as the number of the aggregated fusion lymphnodes increased with the increase in the size of the lymphonodes. It was concluded that the transglottic carcinoma should be defined as one with the main lesion locates in the ventricle, or the ventricle being the center with transglottic spread. Since the barrier of ventricle was weak, partial laryngectomy should be performed with care, and ipsilateral neck dissection shoud be included during operation.

Adult↗
PubMed1997

[Sample pretreatment method for assay of chlorogenic acid in Chinese medicinal preparations].

This paper introduces a sample pretreatment method for assaying chlorogenic acid-D101-column separation-precipitation method. The method features thorough removal of impurities, complete separation of chlorogenic acid and simple operational procedures. The experimental result of four samples from three preparations shows that this method is good in reliability and applicability.

Chlorogenic Acid↗
PubMed1997

[Biocompatibility evaluation of Ti50Ni50-xCux shape memory alloys (I)--corrosion resistance].

By means of electrochemical methods, the corrosion resistance of Ti50Ni50 and Ti50Ni50-xCux (x = 1,2, 4,6,8) was investigated. It is discovered that repassivation potential of Ti50Ni50-xCux (x = 2,4,6,8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. This means that the added Cu raises the repassivation of TiNi shape memory alloys and improves corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1,2,4,6,8) alloys increase with the rising solution pH value, but the repassivation potentials keep constant. The added Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1,2,4,6,8) alloys are irrelevant to its Cu content and the values are almost the same as that of TiNi alloys.

Alloys↗
PubMed1997

Electrochemical and histomorphometric evaluation of the TiNiCu shape memory alloy.

By means of electrochemical and quantitative histomorphometric methods, the corrosion resistance and tissue biocompatibility of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) were investigated. It is discovered that the repassivation potential of Ti50Ni50-xCux (x = 2, 4, 6, 8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. Namely, the addition of Cu raises the repassivation potential of TiNi shape memory alloys and improves their corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys increase with solution pH value, but the repassivation potentials keep constant. The adding of Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys are irrelevant to its Cu content and the values are almost the same as those of TiNi alloys. The connective tissue layer covering the plates is statistically significantly thicker for Ti50Ni42Cu8 plates (p < 0.05) than that of Ti50Ni50, Ti50Ni48Cu2, Ti50Ni44Cu6 plates after one month. The numbers of connective tissue cells, polynucleated cells, macrophages and round cells are higher for Ti50Ni42Cu8 plates than those of the other three types of plates, but no statistically significant differences are detected. There are no significant differences on tissue reaction parameters after two and three months among four alloys. After one, two and three months implantation, no corrosion is observed on the plates surfaces. A preliminary conclusion can be drawn that Ti50Ni50-xCux (x = 2, 6, 8) shape memory alloys have good biocompatibility.

Alloys↗
PubMed1997

Effects of photon attenuation on increased counts in fanbeam collimation.

UNLABELLED: This study examined the effects of photon attenuation on the increased sensitivity (gain of counts) produced by a fanbeam collimator with imaging geometry similar to clinical practice. METHODS: The number of counts was measured in experiments and by computer simulations for two cylindrical phantoms of different sizes using a fanbeam and a parallel-hole (parallel-beam) collimator with the same spatial resolution. The phantoms were located either in air (simulating the brain) or in a cubic water tank (simulating a source in the body). The ratio of the counts from the fanbeam collimator versus the parallel-beam collimator was obtained as a function of the distance between the phantom and detector. RESULTS: Even with attenuation inside the phantom, the count ratio for the phantom located in air remains almost the same as that theoretically predicted without attenuation. But the count ratio obtained in the cubic water tank was decreased compared to the predicted values. The amount of decrease (reduced sensitivity) depended on the distance from the detector, the size of the source and the depth of the source. CONCLUSION: For brain studies, attenuation caused little change in the gain of counts provided by a fanbeam collimator. When imaging a structure located deep within the body, however, the gain of counts (sensitivity) may be appreciably reduced due to a longer path of photons within the body which results in more photon attenuation in fanbeam geometry.

Brain↗
PubMed1997

[Chemotherapy repeated injection via pelvic retroperitoneal cannulation].

OBJECTIVE: To investigate the feasibility of chemotherapy for lymphatic metastases of gynecologic cancer by repeated injection via pelvic retroperitoneal cannulation. METHODS: 5-fluorouracil (5-FU), thiotepa, methofrexate were repeatedly injected into the pelvic retroperitoneal space of 25 dogs and 24 patients respectively via cannulation. Microscope and high-performance liquid chromatography were used to observe the drug concentration of 5-FU and pathologic changes of the involved tissues. RESULTS: Animal experiment showed no toxicity to vessels, ureter and the normal tissues involved; nodal 5-FU concentration of repeated injection side was 7 to 9 times of that on the peripheral connective tissue (P < 0.05). Clinical study revealed: (1) the external iliac, hypogastric, obturator, deep inguinal and most of the common iliac lymph nodes were submerged in the 5-FU solution; (2) pelvic and periaortic nodal 5-FU concentrations of repeated injection side were 20 to 73 and 27 to 110 times of that on single injection side respectively; nodal 5-FU concentration was 11 to 20 times of that on the peripheral connective tissue; (3) metastatic cancer cells of nodal in the study group showed obvious degeneration and necrosis while no changes in the control; (4) no severe complications or adverse effects were observed. CONCLUSION: Repeated injection via pelvic retroperitoneal cannulation was feasible and probably more effective for the treatment of lymphatic metastases of gynecologic cancer.

Animals↗
PubMed1997

[Biologic effects of introduction of wild-type p53 cDNA into a human ovarian cancer cell line SKOV-3].

OBJECTIVE: To study the effects on biologic behavior in cells obtained from human ovarian cancer cell line SKOV-3 into which the wild-type p53 cDNA was introduced. METHOD: Recombinant eukaryotic expression vector pC53-SN3 containing full-length human wild-type p53 cDNA and vector containing neomycin resistance gene only were introduced by lipofectamine-mediated gene transfection into SKOV-3 cell line which does not express endogenous p53. The clones obtained were observed for their biologic behavior. RESULTS: (1) 2 clones named pC53 and 2 clones named pNeo were obtained after pC53-SN3 and vector transfection respectively; (2) The morphology of cells either from pC53 or from pNeo did not change significantly with respect to their parental SKOV-3; (3) The growth rate of cells from pC53 was much slower than that from SKOV-3, while the cell growth curve of pNeo was similar to that of SKOV-3; (4) The number of colones formed in the soft-agar by pC53 was significantly less than that by SKOV-3 or by pNeo; (5) The percentage of phase G1/G0 of pC53 was much higher than that of SKOV-3 and pNeo. CONCLUSION: Wild-type p53 cDNA may be considered as one of the target genes for the gene therapy of ovarian cancer.

Cell Cycle↗
PubMed1997

[Effects of glutamate and ATP on interleukin 6 production by cultured neonatal rat astrocyte].

The effects of glutamate (Glu) and ATP on interleukin-6 (IL-6) production from cultured neonatal rat astrocyte were studied. Glu (100-200 mumol.L-1) strongly increased, IL-6 production at 16 h in a dose-dependent manner and ATP (50-100 mumol.L-1) induced a inhibition effect. The results suggest that Glu stimulted IL-6 release may be one of mechanisms of astrocyte "neuroprotective" function in ischmia/reperfusion.

Adenosine Triphosphate↗
PubMed1997

[The sonarographic diagnosis of prostatic and periprostatic cysts on high resolution transrectal ultrasound imaging].

The symptoms of prostatic and periprostatic cysts are nonspecific and digital rectal examination has no definite findings detected. The conventional radiological plain film cannot define the relationship of a cyst to the surrounding structures. The use of MRI as a means in detection is too expensive. To solve these problems, we detected 118 cysts in 73 patients by transrectal ultrasound (TRUS) and discussed the TRUS imaging findings of various prostate and periprostate cysts with illustrations from our clinical practice. We suggest that TRUS can be used routinely, because its distinct advantage of high resolution for minute nodular or cystic lesion detection with high quality image demonstrates the relationship of surrounding structures, and provides an outstanding novel diagnostic modality.

Adult↗