Biomedical subjects

Y J Yang

Publications and source records attributed to Y J Yang.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Effect of baicalin and dexamethasone on cytokines in brain tissue of infectious brain edema].

OBJECTIVE: To explore the effect of baicalin(BC) and dexamethasone(DXM) on interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha(TNF-alpha) in brain tissues of infectious brain edema. METHODS: The infectious brain edema model induced by pertussis bacilli(PB) was used. Brain water content(WC), content of Na+ and the levels of IL-1 beta, TNF-alpha were determined, and the morphological changes were observed under the light microscope. RESULTS: The results showed that the levels of WC, Na+, IL-1 beta and TNF-alpha in group PB were higher than those in group of normal saline(NS) (P < 0.01). And they were lower in groups BC and DXM than those in group PB(P < 0.05). In groups BC and DXM, there were no significant difference in the contents of water, Na+, IL-1 beta and TNF-alpha(P > 0.05). The water contents were positive linar correlated with IL-1 beta or TNF-alpha(P > 0.05). The water contents were positive linear correlated with IL-1 beta or TNF-alpha contents(r = 0.9381, 0.8349, P < 0.01). The structure of brain tissues in group NS was normal. In group PB, there were severe edema in brain tissues. In groups BC and DXM, the edema of brain tissues was reduced. CONCLUSIONS: The results suggest that the protective effect of BC and DXM against infectious brain edema were similar, the mechanism may be associated with the reduction of TNF-alpha and IL-1 beta.

Animals↗

PubMed2000

[Comparison of infectious brain edema models induced by different kinds of pertussis bacilli in rats].

OBJECTIVE: To understand the difference of infectious brain edema models induced by varied kinds of pertussis bacilli in rats and to look for a new infectious brain edema model. METHODS: Sprague-Dawley rats were randomly divided into 3 groups: normal saline group(NS); rude pertussis bacilli(PBR); purified pertussis bacilli(PBP). After infectious brain edema model was induced by rude pertussis bacilli or purified pertussis bacilli, the water content(WC), Evan's blue content(EB), Na+ and K+ content in brain tissues were measured. RESULTS: The WC, EB and Na+ contents in brain tissues in PBR and PBP groups were significantly increased than those in NS group; K+ content was significantly decreased in PBR and PBP groups than that in NS group(P < 0.01). Evan's blue discoloration was demonstrated in all rats of PBR group, but 6 rats of PBP group showed bluish discoloration. EB content in brain tissues was significantly increased in PBR group than that in PBP group. CONCLUSIONS: The infectious brain edema model can be induced by rude pertussis bacilli or purified pertussis bacilli in rats, the former gives priority to mixed brain edema, and the latter mainly avails cytotoxin brain edema.

Animals↗

PubMed2000

Gas chromatographic-mass spectrometric determination of plasma saturated fatty acids using pentafluorophenyldimethylsilyl derivatization.

An improved method for the detection of 11 saturated fatty acids (SFAs) including C12:0-C26:0 (even numbers only), C17:0, C19:0 and C23:0 in human plasma by gas chromatography-mass spectrometry (GC-MS) with a stable isotope internal standard as d3-stearic acid is described. This procedure was based on acidic treatment, liquid-liquid extraction, and chemical derivatization prior to instrumental analysis. Eleven pentafluorophenyldimethylsilyl-SFA derivatives were well separated without any interfering peaks in plasma samples. The characteristic ions at M-15, constituting the base peaks in the electron impact mass spectra for 11 SFAs, permitted their sensitive detection by GC-MS in the selected ion monitoring (SIM) mode. The SIM responses were linear with correlation coefficients varying from 0.993 to 0.999 in the concentration range of 0.05 to approximately 50 microg/ml for the 11 SFAs. The detection limits for SIM of the SFAs varied in the range of 0.05 to approximately 10.0 pg. When applied to the plasma samples of normal subjects and patients with X-linked adenoleukodystrophy, which is one of the hereditary peroxisomal disorders, the present method enabled us to determine the SFAs with good sensitivity and good overall precision and accuracy within the concentration ranges of 0.14 to approximately 82.35 micromol/l.

Adolescent↗

PubMed2000

[Protective effects of baicalin, mannitol and dexamethasone on infective brain edema in rats].

OBJECTIVE: To compare the therapeutic effects of baicalin, mannitol and dexamethasone on infective brain edema(IBE) in rats. METHODS: Forty normal Sprague-Dawley(SD) rats (200 +/- 30) g by weight were divided into 5 groups randomly: (1) normal saline control group(NS, n = 8); (2) infective brain edema group (BE, n = 8); (3) mannitol treatment group(MAN, n = 8); (4) dexamethasone treatment group(DXM, n = 8); and (5) baicalin treatment group(BC, n = 8). Pertussis bacilli(PB, contained bacilli in 10.8 x 10(9), 0.2 ml-1.kg-1) were injected into the left carotid arteries through the left common carotid arteries by puncture to obtain BE models. The contents of brain water, sodium ion, potassium ion and Evans blue in brain tissues were observed too. RESULTS: The contents of brain water, sodium ion, and EB in BE group were higher than those in BE group(P < 0.01), they decreased in MAN, DXM, BC groups and were lower than those in BE group(P < 0.01). In MAN, DXM, BC groups, there were no significant difference in the contents of brain water and sodium ion(P > 0.05). The EB content in BC group was higher than that in MAN and DXM groups(P < 0.01). The content of potassium ion in BE group was higher than that in MAN and DXM groups, the content of potassium ion was similar to that in NS group, but lower than that in BC group. Light microscope inspection in MAN, DXM and BC groups showed lessened brain edema, slight increase of perivascular space, and occasional nerve cell pyknotic nucleus. We found on nerve cell vacuolar degeneration in DXM group. CONCLUSION: Baicalin, mannitol and dexamethasone all have similar protective effects on infective brain edema in rats.

Animals↗

PubMed2000

Fluid therapy of acute brain edema in children.

The clinical experience with a new fluid therapy in children with acute brain edema complicated by infectious disease is reported. The clinical data of a retrospective group of 192 patients and a prospective study of 1,302 and 2,279 patients is summarized. One method of fluid therapy for children with acute brain edema is traditional; fluid intake is restricted to less than 1,200 mL/m(2) daily (60 mL/kg daily). Another method is the new fluid therapy regimen used in our prospective study, in which dehydration and fluid replenishment are individualized. On the first day the fluid intake of patients who survived varied from 40 to 208 mL/kg daily. The mortality rate in the two prospective groups was 19.66% in 1,302 patients and 17.2% in 2,279 patients, significantly lower than the 63.5% in the retrospective group (192 patients) (P <0.001). This result indicates that a wide range of fluid intake for children with acute brain edema is allowable during the first days of treatment. The appropriate dehydration and fluid replenishment should be individualized based on close observation of the patient's condition.

Acute Disease↗

PubMed2000

Modeling and direct sensitivity analysis of biogenic emissions impacts on regional ozone formation in the Mexico-U.S. border area.

A spatially and temporally resolved biogenic hydrocarbon and nitrogen oxides (NOx) emissions inventory has been developed for a region along the Mexico-U.S. border area. Average daily biogenic non-methane organic gases (NMOG) emissions for the 1700 x 1000 km2 domain were estimated at 23,800 metric tons/day (62% from Mexico and 38% from the United States), and biogenic NOx was estimated at 1230 metric tons/day (54% from Mexico and 46% from the United States) for the July 18-20, 1993, ozone episode. The biogenic NMOG represented 74% of the total NMOG emissions, and biogenic NOx was 14% of the total NOx. The CIT photochemical airshed model was used to assess how biogenic emissions impact air quality. Predicted ground-level ozone increased by 5-10 ppb in most rural areas, 10-20 ppb near urban centers, and 20-30 ppb immediately downwind of the urban centers compared to simulations in which only anthropogenic emissions were used. A sensitivity analysis of predicted ozone concentration to emissions was performed using the decoupled direct method for three dimensional air quality models (DDM-3D). The highest positive sensitivity of ground-level ozone concentration to biogenic volatile organic compound (VOC) emissions (i.e., increasing biogenic VOC emissions results in increasing ozone concentrations) was predicted to be in locations with high NOx levels, (i.e., the urban areas). One urban center--Houston--was predicted to have a slight negative sensitivity to biogenic NO emissions (i.e., increasing biogenic NO emissions results in decreasing local ozone concentrations). The highest sensitivities of ozone concentrations to on-road mobile source VOC emissions, all positive, were mainly in the urban areas. The highest sensitivities of ozone concentrations to on-road mobile source NOx emissions were predicted in both urban (either positive or negative sensitivities) and rural (positive sensitivities) locations.

Agriculture↗

PubMed2000

Potentials and limitations of adenovirus-p53 gene therapy for brain tumors.

We investigated the antineoplastic potentials of recombinant adenovirus containing wild-type p53 cDNA (Ad5CMV-p53) for malignant gliomas. In four human glioma cell lines (U-251 and LG expressing endogenous mutant p53, and U-87 and EFC-2 expressing wild-type p53) and two rat glioma cell lines (9L and C6, each expressing mutant and wild-type p53), gene transfer efficiency determined by X-gal staining and Western blotting was varied (10-99% at 10-500 multiplicity of infection, MOI). Growth inhibitory effect was drastic (>90% at 100 MOI) in U-251 cells and only moderate or minimal in other cell lines harboring wild-type p53 or low gene transfer efficiency. Ex vivo transduction of U-251 cells with Ad5CMV-p53 suppressed the in vivo tumorigenicity of the cells. Histopathologic examination for Ad5CMV-p53 toxicity to rat brains showed inflammatory reactions in half of the tested brains at 10(8) MOI. U-251 cells were inoculated intracerebrally in nude mice and injected Ad5CMV-p53 into the tumor, in which neither the tumor suppression nor the survival benefit was observed. In conclusion, heterogeneity of the cellular subpopulations of malignant glioma in p53 status, variable and insufficient gene delivery to tumor, and adenoviral toxicity to brain at higher doses may be limiting factors to be solved in developing adenovirus-p53 gene therapy for malignant gliomas.

Adenoviruses, Human↗

PubMed2000

Diagnosis of papillary carcinoma in a thyroglossal duct cyst by fine-needle aspiration biopsy.

The incidence of papillary thyroid carcinoma arising in a thyroglossal duct cyst is rare and occurs in about 1 % of thyroglossal duct cysts. Only 17 such cases diagnosed with fine-needle aspiration biopsy have been previously reported in the English-language literature, with a diagnostic rate of 53%. In this article, the cytologic features of the current case are emphasized and those of the previous reported cases are briefly reviewed. Diagnostic pitfalls of papillary carcinoma arising in thyroglossal duct cysts diagnosed by fine-needle aspiration biopsy are also discussed.

Adult↗

PubMed2000

Efficient inhibition of in vivo human malignant glioma growth and angiogenesis by interferon-beta treatment at early stage of tumor development.

Malignant gliomas are highly angiogenic and aggressive tumors. IFN-beta has been used for the treatment of patients with malignant glioma; however, its antitumor mechanism in vivo remains unclear. To understand the in vivo antitumor effect and mechanism of recombinant human IFN-beta (rhIFN-beta) depending on the stages of tumor development or progression, we used orthotopic xenograft brain tumors generated by stereotactic intracerebral implantation of U-87 human glioma cells in nude mice. Mice bearing tumors 7 days (group 1) and 21 days (group 2) postimplant were treated with 2 x 10(5) IU/day of rhIFN-beta or saline i.p. for 15 days, respectively. Tumor growth was suppressed by 69.6% in group 1 and 10.8% in group 2 compared with tumors of each control group treated with saline. rhIFN-beta-treated group 1 animals showed 38% reduction in vascularization along with a 2.5-fold increase of the apoptotic index and no change in the proliferative index as compared with untreated tumors. The expression level of vascular endothelial cell growth factor and basic fibroblast growth factor was not affected by rhIFN-beta treatment. rhIFN-beta showed inhibitory activity on proliferation of U-87 cells, human umbilical vein endothelial cells, and PAM 212 murine keratinocytes in vitro. Our results indicate that the in vivo antitumor effect of rhIFN-beta on malignant gliomas may be mediated, at least in part, via angiogenesis inhibition rather than antiproliferative activity and that rhIFN-beta may be more effective for the treatment of malignant glioma patients at an early stage with minimal or microscopic tumor burdens rather than at an advanced stage of tumor development.

Angiogenesis Inhibitors↗

PubMed2000

Complications of varicella in children: emphasis on skin and central nervous system disorders.

A review of medical records at a tertiary hospital in southern Taiwan from June 1988 through May 1998 identified 136 children who had been hospitalized for varicella-related complications. Of the children, 83% (113/136) were healthy before the onset of varicella and 17% (23/136) had underlying illnesses. The mean age was 4.7 years (ranged from 1 day to 18 years) with a male predominance (1.7:1). The mean hospital stay was 5.5 days (ranged from 1 to 22 days). Secondary bacterial skin or soft tissue infections were the most common complications (44%), followed by central nervous system (CNS) involvement (23%), pneumonia (18%), thrombocytopenia (12%), and liver function impairment (10%). Among the 60 patients with secondary bacterial cutaneous infection, 16 (27%) had positive isolates, including 12 isolates of Staphylococcus aureus and four Streptococcus pyogenes. Age above 8 years was significantly associated with the development of varicella-associated CNS complications (p = 0.019). Of the 23 immunocompromised hosts, the most common underlying conditions were hematological diseases (11 patients, 48%), followed by neonatal varicella (7 patients, 30%) and chronic illness with steroid treatment (5 patients, 22%). All of the subjects in this study had a favorable outcome except for three lethal cases, resulting in a case-fatality rate of 2.2%. The cause of death was S. aureus septicemia in one patient, streptococcal toxic shock syndrome in one patient, and encephalitis with brain herniation in one patient. Our results demonstrate that varicella continues to be a serious disease that occasionally results in life-threatening complications in healthy and immunocompromised children. Routine immunization of all healthy children against varicella is recommended.

Adolescent↗

PubMed2000

Brachial plexus injury following coronary artery bypass surgery: a case report.

Postoperative brachial plexus injury, often manifesting as a variety of upper extremity neuropathies, is a recognized and not uncommon complication following cardiac surgery that requires a median sternotomy. In general, the vast majority of its neurological symptoms are transient and need no treatment. Nevertheless, in very rare cases, the peripheral neuropathies will persist and cause disability. We treated a 67-year-old male patient complicated by permanent paresthesia and paralysis of the left upper extremity after an eventful coronary artery bypass surgery. The nerve conduction measurements and electromyography all revealed a C5 to T1 lesion. After carefully reviewing the surgical course and referring to the published literature, we tentatively concluded that compression or overstretching produced by wide and prolonged sternal separation of the brachial plexus was the most likely etiology. Asymmetrical traction of the sternal halves during internal mammary artery harvesting might also have contributed to this nerve injury. We surmised, therefore, that brachial plexus injury could be minimized by an exact median sternotomy, a lower position and the smallest possible opening for the sternal retractor, and the avoidance of constant and asymmetrical traction on the sternal halves.

Aged↗

PubMed1999

Inhibition of human malignant glioma growth in vivo by human recombinant plasminogen kringles 1-3.

Human malignant gliomas are highly vascularized and aggressive tumors. Angiogenesis inhibitors have been shown to induce regression of a variety of primary and metastatic tumors in vivo. However, their usefulness in treating brain tumors is not well understood. Angiostatin, a multiple kringle (1-4 of 5)-containing fragment of plasminogen, is one of the highly effective natural cryptic angiogenesis inhibitors. In our study, the therapeutic efficacy of non-glycosylated and small molecular size recombinant kringles 1-3 (rPK1-3) was examined in the treatment of brain tumors generated by stereotactic intracerebral implantation of U-87 human glioma cells in nude mice. Mice bearing tumors 7 days post-implant were treated daily with rPK1-3 (100 mg/kg) s.c. for 21 days. Treated animals showed suppressed brain tumor growth by greater than 71.2% along with a 3-fold increase of apoptotic index and suppressed vascularization by 78.9%, without any observable signs of toxicity. Analysis of bFGF and VEGF expression in the tumors of treated animals using immuno-histochemical methods showed near complete absence of growth factors. Our results indicate that the non-glycosylated, small molecular size rPK1-3 is an efficient tumoristatic agent for the treatment of intracranial human glioma xenografts in mice and might provide new strategies for the treatment of brain tumors.

Animals↗

PubMed1999

Double-lumen aortic arch with anomalous left pulmonary artery origin from the main pulmonary artery--bilateral persistent fifth aortic arch--a case report.

Both double-lumen aortic arch (i.e., persistent fifth arch) and anomalous origin of the left pulmonary artery from the ascending aorta (failure of the development of the sixth arch) are rare diseases. They are frequently associated with cardiovascular anomalies. However, the co-occurrence of these two diseases has not been previously reported. We report such a case in a female baby with facial anomalies similar to conotruncal anomaly face syndrome.

Abnormalities, Multiple↗

PubMed1999

Comparison of fatty acid profiles in the serum of patients with prostate cancer and benign prostatic hyperplasia.

OBJECTIVE: The role of dietary fatty acids (FAs) in benign and malignant prostatic diseases was investigated by comparing the composition value of serum fatty acids in the normal controls, and patients with prostate cancer (PC) and benign prostatic hyperplasia (BPH). Also, to estimate a possible association between PC risk and PUFAs, omega-3, omega-6 and omega-3/omega-6 FA composition ratios were compared among these groups. METHODS: Serum samples were obtained from 24 BPH and 19 PC patients, and from 21 age-matched normal male subjects. The serum concentration of 21 fatty acids was determined using gas chromatography/mass spectrometry. RESULT: The proportional values of saturated fatty acids (SFAs) groups demonstrated no specific difference between the control subjects and the patients. In the polyunsaturated fatty acids (PUFAs), we found that the omega-3 PUFAs level was significantly decreased in patient with BPH and PC and that the omega-6 PUFAs level was increased in PC only. The ratio of omega-3/omega-6 PUFAs decreased in the following order of normal, BPH, and PC. CONCLUSION: It was proposed that the changed composition level of PUFAs including omega-3 and omega-6 PUFAs have certain relationship with both prostatic diseases. Therefore, the ratio of omega-3/omega-6 PUFAs also may have an important association with the benign and malignant status of prostatic disease.

Case-Control Studies↗

PubMed1999

Epstein-Barr virus-containing T-cell lymphoma and atherosclerotic abdominal aortic aneurysm in a young adult.

Malignant lymphoma infiltrating the abdominal aorta and resulting in an aortic aneurysm has never been documented. We report here a case of angiocentric T-cell lymphoma in a 33-year-old man who for months presented intermittent fever, splenomegaly, and an abdominal pulsatile mass. Angiography revealed extensive aneurysmal dilatation of the infrarenal abdominal aorta, bilateral iliac artery, and right common femoral artery. Splenic abscess and infected abdominal aortic aneurysm were initially suspected. An urgent splenectomy and aneurysmectomy with an aortic bifemoral bypass were performed. Pathological examination of the aortic aneurysm showed extensive necrosis, severe atherosclerosis, and lymphoma cell infiltration of the aortic wall. The lymphoid cells in the aorta and spleen were stained positive for CD45RO, CD56, and CD8, but negative for CD4 and CD19. Double-labeling immunohistochemistry and in situ hybridization using EBER1 for Epstein-Barr virus (EBV) revealed positive nuclear staining in the atypical T-lymphoid cells. This is the first definitive proof of peripheral T-cell lymphoma involving the abdominal aorta. Our evidence also supports that the EBV infection of T cells could be responsible for the atherosclerosis and hypertriglyceridemia, and the angiocentricity of the tumor cells apparently results in the presenting atherosclerotic aortic wall destruction, providing an additional causative concept for abdominal aortic aneurysm.

Adult↗

PubMed1999

Clinical spectrum of enterovirus 71 infection in children in southern Taiwan, with an emphasis on neurological complications.

An outbreak of enterovirus 71 (EV71) infection occurred in Taiwan in 1998. The clinical spectrums and laboratory findings for 97 patients with virus culture-proven EV71 infections were analyzed. Eighty-seven percent of the patients were younger than age 5 years. Hand-foot-and-mouth syndrome occurred in 79% of the children and central nervous system (CNS) involvement in 35%, including nine fatal cases. The predominant neurological presentations were myoclonus (68%), vomiting (53%), and ataxia (35%). Brain stem encephalitis was the cardinal feature of EV71 CNS involvement during this outbreak. Magnetic resonance imaging and pathological findings illustrated that the midbrain, pons, and medulla were the target areas. EV71 brain stem encephalitis can present either with cerebellar signs and an initially mild, reversible course or with overwhelming neurogenic shock and neurogenic pulmonary edema (NPE) resulting in a fatal outcome. Brain stem encephalitis that progressed abruptly to neurogenic shock and NPE was indicative of poor prognosis in this epidemic. Early aggressive treatment and close monitoring of the neurological signs are mandatory to improve the chance of survival.

Adolescent↗

PubMed1999

Cervical adenoid cystic carcinoma coexisting with multiple human papillomavirus-associated genital lesions. A common etiology?

Adenoid cystic carcinoma of the uterine cervix is a rare tumor with unknown etiology. We report a case of adenoid cystic carcinoma occurring in a young woman, associated with multiple human papillomavirus (HPV)-related lesions including condyloma acuminata, vulvar intraepithelial neoplasm, cervical intraepithelial neoplasm and invasive basaloid squamous cell carcinoma. While adenoid cystic carcinoma has previously been found to coexist with squamous cell carcinoma or cervical intraepithelial neoplasia, its association with such a variety of HPV-related lesions in our case has not been previously reported, and raises the speculation that HPV may also be the causative factor for adenoid cystic carcinoma. However, in situ DNA hybridization and polymerase chain reaction in our current study failed to demonstrate the existence of HPV DNA in adenoid cystic carcinoma.

Adult↗

PubMed1999

Papillary thyroid carcinoma with nodular fasciitis-like stroma. Pitfalls in fine-needle aspiration cytology.

Papillary thyroid carcinoma with nodular fasciitis-like stroma is one of the rare variants of papillary thyroid carcinoma. The problems posed by the exuberant nodular fasciitis-like stroma, which obscures the neoplastic nature of the tumor, are recognized in surgical pathology but have received little attention in the cytopathology literature. We report a rare case of papillary thyroid carcinoma in which nodular fasciitis-like stroma posed difficulty on fine-needle aspiration cytology. The differential diagnosis of fibroproliferative processes in thyroid fine-needle aspirations is also discussed.

Aged↗