Biomedical subjects

Ning Zhang

Publications and source records attributed to Ning Zhang.

158 records · Page 9Linked to original sources

PubMed2002

Effect of hypothermia on cerebral blood flow and metabolism in the pig.

BACKGROUND: The pig has become an increasingly popular model for the study of cerebral protection during cardiothoracic surgery in recent years, but little information is available concerning hypothermic porcine physiology. Because the efficacy of cerebral protection depends largely upon metabolic suppression, we studied cerebral oxygen metabolism at various temperatures using two different methods to assess cerebral blood flow (CBF). MATERIAL AND METHODS: Twelve pigs (7 to 13 kg) underwent cooling on cardiopulmonary bypass to 8 degrees C as recorded by an electrode placed deep in the parenchyma of the brain. CBF was measured in 6 animals using radioactive microspheres and in the other 6 using fluorescent microspheres. CBF, cerebral oxygen consumption, and cerebral vascular resistance were determined at 37 degrees C, 28 degrees C, 18 degrees C, and 8 degrees C. RESULTS: Both methods produced very similar data. CBF fell steadily with decrease in temperature to 18 degrees C but failed to drop further with more profound hypothermia. With both groups combined, mean cerebral oxygen metabolism was 2.63 mL/100 g per minute at 37 degrees C. Metabolic activity was 50% of base line values at 28 degrees C, 19% at 18 degrees C, and 11% at 8 degrees C. The Q10 value in the pig--the degree of metabolic suppression achieved by a 10 degrees C drop in temperature--is 2.46 (95% confidence interval 2.1 to 2.9); this value is consistent with similar studies in humans. CONCLUSIONS: The presence of significant residual metabolic activity at 18 degrees C suggests that this degree of hypothermia may provide incomplete cerebral protection during prolonged interruption of CBF. This study demonstrates that cooling to temperatures below 18 degrees C in the pig can achieve greater metabolic suppression although it may be associated with loss of cerebral autoregulation.

Animals↗

PubMed2002

Impact of high intracranial pressure on neurophysiological recovery and behavior in a chronic porcine model of hypothermic circulatory arrest.

OBJECTIVE: This review was undertaken to determine whether high intracranial pressure (ICP) during reperfusion after hypothermic circulatory arrest (HCA) correlates with evidence of suboptimal cerebral protection in a chronic porcine model. METHODS: In concurrent studies of cerebral protection, 48 control pigs (24-31 kg) underwent 90 min of HCA at 20 degrees C using a strictly standardized protocol. Hemodynamic measurements, ICP and neurophysiological data (EEG, SSEP) were assessed before HCA and until 3 h postoperatively. ICP was measured using a Codman microtip catheter inserted directly into brain parenchyma. Neurological/behavioral evaluation (9=full recovery) was carried out daily through postoperative day (POD) 3. RESULTS: There were no significant hemodynamic or metabolic differences between individual animals. ICP (mmHg) increased significantly for the first 3 h after HCA: from baseline levels of 6.2+/-2.1 to 10+/-2.6 at 1 h, 11+/-3.2 at 2 h and 10+/-3.6 mmHg at 3 h; P<0.001 for the trend. EEG recovery 3 h after HCA was observed in 13 animals (27%), and correlated with lower ICP during reperfusion (P<0.001): with each 1 mmHg increase in ICP at 3 h, the odds of early EEG recovery decreased by a factor of 0.72. Lower ICP during reperfusion was also significantly associated with higher behavioral scores on POD 1 and 2, P<0.001. CONCLUSIONS: A significant rise in ICP may help explain the prolonged obtundation and confusion often seen clinically after HCA. If these small but consistent increases in ICP contribute to rather than reflect ischemic neuronal damage, simple maneuvers to reduce ICP may improve cerebral recovery after HCA.

Animals↗

PubMed2002

Spectroscopic behavior on the formation complex of three double-armed calix[4]arene derivatives with lanthanoid nitrates in acetonitrile.

The complexation spectroscopic behavior of three p-tert-butylcalix[4]arene Schiff bases i.e. 5,11,17,23-tetra-tert-butyl-25,27-bis[2-[N-(3-nitrobenzylidene)amino]ethoxy]-26,28-dihydroxycalix[4]arene (1), 5,11,17,23-tetra-tert-butyl-25,27-bis[2-[N-(2-hydroxybenzylidene)amino]ethoxy]-26,28-dihydroxycalix[4]arene (2), and 5,11,17,23-tetra-tert-butyl-25,27-bis[2-[N-(2-hydroxy-3-methoxybenzylidene)amino]ethoxy]-26,28-dihydroxycalix[4]arene (3) with lanthanoid nitrates (Tb3+ and Eu3+) has been investigated in anhydrous acetonitrile at 25 degrees C by using UV-vis and FT-IR as well as fluorescence spectra. The results obtained indicated that the spectroscopic behavior of compounds 1-2 upon complexation with lanthanoid ions did not show any significant larger difference in comparison with free compounds 1 and 2, which may be contributed to the poor binding ability. Contrary to compounds 1 and 2, the lower rim functional groups in compound 3 can form two large pi electron conjugate system with lanthanide ion and encapsulate lanthanide ions tightly, displaying the novel spectroscopic behavior upon complexation with lanthanide ions. As compared with compound 3, the formation complexes of compound 3 with Tb3+ and Eu3+ showed new broad intense absorption at 398 nm, respectively, and IR spectra showed that O-H stretching vibration at 3413.40 cm(-1) displayed a large drop. It is interestingly noted that the narrow emission line spectra were observed only for 3 complex with Tb3+, but did not for 3-Eu3+ complex. In the 3-Eu3+ complex, the broad-band emission at lambda(max) = 534 nm was obtained at the excitation of 398 nm. The spectroscopic behavior of three calix[4]arene derivatives upon complexation with lanthanoids was discussed from the relationship between the host structure and the properties of guest lanthanide ions.

Acetonitriles↗

PubMed2002

[Pathogenic factors of convulsion in neonates with hypoxic-ischemic encephalopathy].

OBJECTIVE: To explore the pathogenic factors of convulsion in neonates with mild to severe hypoxic-ischemic encephalopathy. METHODS: Altogether 70 neonates with mild to severe hypoxic-ischemic encephalopathy (HIE) were admitted into our hospital between Jan. 1988 and Jan. 2001. Serum calcium was dynamically monitored in all the patients, with cerebral ultrasonography performed. RESULTS: Convulsions occurred within the first and second days after birth in the neonates of convulsion group, whose serum calcium levels were significantly decreased during the third to sixth days in comparison with those of non-convulsion group (P<0.01). Cerebral ultrasonography showed that 1 to 3 d after birth, cerebral edema occurred in all the neonates of convulsion group (n=39), with 30 of them having diffuse edema. Cerebral edema was gradually alleviated in the fourth to seventh day after birth. In non-convulsion group (n=31), 14 patients suffered diffuse cerebral edema within 2 d after birth, an incidence significantly lower than that in convulsion group. Intracranial hemorrhage took place in 23 neonates in convulsion group (58.97 %), and the incidence in non-convulsion group was only 38.7 %. CONCLUSION: The principal causes of convulsions in neonates include hypoxia and cerebral edema, along with secondary causes such as birth trauma and hypocalcemia.

Calcium↗

PubMed2002

[Establishment and characteristics of orthotopically transplanted model of human primary malignant spleen lymphoma in nude mice].

OBJECTIVE: To establish three orthotopically transplanted model of human primary malignant spleen lymphoma in the nude mice. METHODS: Orthotopic transplantation of histologically intact human primary malignant splenic lymphoma tissue obtained from patients was introduced into the splenic parenchyma of nude mice. Tumorigenicity, invasion, metastasis and morphological characteristics of the transplanted tumor were studied by light microscopy, electron microscopy and immunohistochemical methods. RESULTS: The first kind, a strain of human primary malignant spleen lymphoma (non-Hodgkin's, cleaved B cell, BFNHL-HMN-1) screened from 11 patients which had been passaged in vivo for 41 generations, a second kind, a liver metastasis model of human primary malignant spleen lymphoma (non-Hodgkin's, cleaved B cell, LM-BFNHL-HMN-2) which had been passaged for 47 generations and a third kind of human primary malignant spleen lymphoma (non-Hodgkin's, T-immunoblastic cell, TINHL-HMN-3) having passaged for 37 generations were all successfully transplanted in 611 nude mice. Models of BFNHL-HMN-1 and TINHL-HMN-3 tumor gave nodular growth and lymph node metastasis in the spleen hilum but without any metastasis in the abdominal lymph nodes or organs. In the LM-BFNHL-HMN-2 model, not only did the tumor cells grow in the spleen, but in spleen hilum, lymph nodes and liver also. The orthotopically transplanted tumor cells were similar to the original human tumor in light histopathology, ultrastructure features, DNA content and chromosomal karyotype. CONCLUSION: These three models are able to serve as useful tools for the study of biologic characteristics and experimental treatment of human primary malignant lymphoma.

Animals↗

PubMed2002

[Preparation of diltiazem hydrochloride delayed-onset, sustained release tablet].

AIM: To prepare dilitazem hydrochloride delayed-onset, sustained release tablet, which can not only provide the delay in release start, but also the constant release rate after a lag time. To analyze release mechanism and investigate the effect of outershell compositions on release behavior. METHODS: The delayed-onset, sustained release tablets were prepared by dry-compression coated technology. The release profiles of uncoated cores and presscoated tablets were compared. Two parameters, time-lag (Tlag) and release rate (k), were used to evaluate the influence of factors, such as the amount of hydroxypropylmethylcellulose (HPMC) and poly-vinyl-pyrrolidinone (PVP) K30, the viscosity of ethylcellulose (EC) and HPMC, and the compression load on diltazam hydrochloride (DIL) release. Higuchi equation and Peppa's equation were used to analyze release mechanism. RESULTS: With the increase of HPMC amount or HPMC viscosity, Tlag was prolonged and k was decreased; With the increase of PVP K30 amount, Tlag was shortened and k was increased; EC viscosity and compression load above certain degree showed no effect on DIL release. CONCLUSION: The drug release from delayed-release tablet is controlled by erosion mechanism, Tlag is determined by the erosion rate of outer-shell.

Cellulose↗

PubMed2002

[Studies on NaNO2-induced DNA mutation by convolution spectrometry].

AIM: To study the sodium nitrite induced DNA mutation by convolution spectrometry (CS). METHODS: The spectra of sodium nitrite-induced mutative calf thymus DNA was compared with ego criteria based on Spectra of the primary DNA within the wavelength range from 200 to 340 nm. Distilled water served as blank and normal saline served as negative control. Any difference was quantitatively expressed by differential value (delta) of convolution spectra. Near-infrared spectroscopy was employed as the reference method. RESULTS: The differential value was positively correlated with the increasing time and concentration of sodium nitrite. delta values increased to 1.37%, 2.41% and 5.44% respectively within 2-hour's reaction between calf thymus DNA and 0.5, 0.05 and 0.005 microgram.mL-1 sodium nitrite, while on the contrary, changes could be hardly observed on the corresponding UV absorption spectra. The results were also confirmed by their corresponding near-infrared spectra. CONCLUSION: The delta values can be used to represent the compound's strength of mutagenesis. Every convolution procedure takes less than one minute, so CS provides a fast, simple and inexpensive alternative method to determine chemical or medicinal DNA mutation.

Animals↗

PubMed2002

[Study on the permeability of 125I-sinomenine via the transdermal delivery way in rats].

OBJECTIVE: To study the permeance and diffusion trend of 125I-sinomenine via the transdermal delivery way in rats. METHODS: Assay the permeance depth and diffusion area of sinomenine labeled by isotopic 125I in subcutaneous of rats certain time after sinomenine was administrated on the cervical skin of rats. RESULTS: The diffuse of sionmenine can reach cervical spine in longitudinal direction and form an area of 2 cm2 in transverse direction. The concentration gradient of both directions are significant. CONCLUSION: 125I-sinomenine can not only be absorbed into blood via the transdermal delivery way to have whole effect, but also accumulate large amounts in the skin to have a local effect.

Administration, Cutaneous↗

PubMed2002

[Clinical observation on effect of zhenqi zhuanyin decoction combined with intrauterine insemination in treating spleen-kidney deficiency type patients of sterility with positive anti-sperm antibody].

OBJECTIVE: To compare the effect of combined therapy of Zhenqi Zhuanyin Decoction (ZQZYD) and timely intrauterine insemination (IUI) with that of using ZQZYD and IUI separately in treating patients of sterility with positive anti-sperm antibody (AsAb). METHODS: One hundred and three patients were randomly divided into 3 groups, 34 patients in Group A treated with combined ZQZYD and IUI, 34 in Group B treated with ZQZYD alone and 35 in Group C treated with IUI alone. The negative conversion rate of AsAb, pregnancy rate in patients, pregnancy rate in AsAb converted patients, as well as changes of TCM Syndrome and T-lymphocyte subsets were observed. RESULTS: (1) The negative conversion rate of AsAb in the 3 groups was 76.47% (26/34), 82.35% (28/34) and 8.57% (3/35) respectively. (2) In Group A, the pregnancy rate was 41.18% (14/34), pregnancy rate in AsAb negative converted patients was 50.0% (13/26); in Group B, the respective criteria was 20.59% (7/34) and 21.43% (6/28) respectively; and in Group C, the pregnancy rate was 11.43% (4/35). The pregnancy rate in Group A was significantly higher than that in Group B or C (P < 0.01). (3) The effective rate on TCM Syndrome in Group A and B was 88.23% and 91.18% respectively (P > 0.05). (4) In Group A and B, CD4 decreased, CD8 increased and CD4/CD8 ratio decreased after treatment, which were significantly different from those before treatment and in Group C after treatment (P < 0.05). CONCLUSION: Combined therapy of ZQZYD and IUAI shows a better effect in treating infertility with positive AsAb than that by ZQXYD or IUI alone.

Adult↗

PubMed2002

[Detection of DNA damage of human sperm using single cell electrophoresis].

OBJECTIVES: To detect the sperm DNA damage and to evaluate its significance in male reproductive using single cell gel electrophoresis (SCGE). METHODS: Four hundred and eighteen sperm samples were analysed using the computer assisted analysis system and SCGE. The sperms samples were divided into five grades according to the extent of the sperm nuclear DNA damage. RESULTS: 1. When the sperm density is less than 20 x 10(6)/ml, the occurence of grade II and III are increased significantly; 2. In the unmotile grade d sperm the occurence of grade I comet amounts was 5.39%, the occurence of grade II and III was remarkably increased. There was a evidently variance between the grade d and grade a + b sperm. CONCLUSIONS: SCGE can be used to detect the sperm DNA breakage and to evaluate the sperm quality and damage.

Adolescent↗

PubMed2002

Serial therapies oriented by surgery for large primary liver carcinoma.

OBJECTIVE: To discuss the methods and effects of serial therapies oriented by surgery in the treatment of primary large liver cancers. METHODS: From January 1993 to June 1999, 191 patients with large liver carcinoma were treated surgically. The size of tumors varied from 5.2 to 19.7 cm (mean 9.4 cm). Several types of liver resections were made in 121 patients and as a supplement, cryosurgery was carried out for the remaining 70 patients. Importable drug delivery system was instituted intraoperatively. Transcatheter arterial chemo-embolization (THP 30-60 mg, E-ADM 20-40 mg, CDDP 40-80 mg, MMC 10-20 mg, iodin oil 5-30 ml), percutaneous ethanol injection, bioimmunotherapy and traditional Chinese medicine were used pre- and post-operatively. CT angiography and CT during arterial portography were used to find satellite nodules. Early stage recurrences were predicted by AFPmRNA in peripheral blood. Child-Pugh's classification plus branch chain amino acid/aromatic amino acid ratio (BCAA/AAA) was adopted in evaluating pre-operative liver functions. RESULTS: Marked results were observed after serial treatments oriented by surgery. The 1-, 3- and 5-year survival rates in resection group were 75.8%, 45.6% and 30.4%, respectively. The 1- and 3-year survival rates in cryosurgery group were 63.2% and 37.0%. The operative mortality was 1.57%. Recurrence rates were 69.2% in AFPmRNA positive group and 33.3% in AFPmRNA negative group (P<0.05). The BCAA/AAA ratio was lower than 1.5 in two patients who died of hepatic failure after resection. CONCLUSIONS: Serial treatments with surgery as the chief modality gives satisfactory results in patients with large primary liver carcinoma. This regimen should be regarded as a main strategy to deal with large liver carcinoma. AFPmRNA in the peripheral blood, signifying a recurrence, may become a new clinical parameter. The BCAA/AAA ratio plus Child-Pugh's classification is able to evaluate more accurately liver function reserve before surgery.

Adolescent↗

PubMed2002

Hepatic trisegmentectomy for 29 patients with huge liver neoplasms.

OBJECTIVE: To evaluate retrospectively the feasibility and effect of hepatic trisegmentectomy in therapy of huge neoplasms of the liver. METHODS: From July 1993 to October 1999, 29 patients with huge hepatic neoplasms underwent hepatic trisegmentectomy. Of these, 23 patients suffered from primary liver cancer, 1 hepatic infiltration of gallbladder cancer, 1 metastasis of colon cancer, 1 hepatic angiosarcoma, 1 hepatic neurofibroma, and 2 huge liver cysts. Twenty-six patients were subjected to right trisegmentectomy and the rest 3 left trisegmentectomy. All trisegmentectomies were performed under normothermic interruption of the porta hepatis at single time and these interruptions lasted 15 to 40 minutes. RESULTS: The relatively good effect was seen in our series. The 1-, 3-, 5-year survival rates for primary liver cancer patients were 63.6%, 36.4% and 27.3%, respectively. The survival period for the patients with hepatic infiltration of gallbladder cancer and liver metastasis of colon cancer was 6 months. Those with hepatic angiosarcoma, hepatic neurofibroma and huge liver cysts have been surviving 35, 26, 25 and 40 months, respectively. Major complications were noted in 5 patients, and one (3.4%, 1/29) died. CONCLUSION: Hepatic trisegmentectomy is safe and effective in treatment of huge hepatic neoplasms if its indications and operative techniques are properly mastered.

Adolescent↗

PubMedDate not supplied

Importance of extrasegmental vessels for spinal cord blood supply in a chronic porcine model.

UNLABELLED: IObjective: Our purpose was to investigate the interaction of the important components of spinal cord blood supply in the pig model to enable its use for future studies of spinal cord protection. METHODS: 25 juvenile pigs (20-22 Kg) underwent serial intercostal (IC) or lumbar artery (LA) ligation until disappearance of motor evoked potentials (MEPs). Pigs underwent sequential craniocaudal (IC/LA ligation alone (n=5); following clamping of both subclavian arteries (n=4)m, or clamping of the median sacral artery (MSA, n=4); preceded by clamping of the subclavian arteries (n=4), or of the MSA (n=4). RESULTS were verified by Tarlov's scores and perioperative angiography. RESULTS: All animals with MEP loss suffered postoperative paraplegia. Groups were equivalent with regard to stable arterial pressures throughout the experiment, temperature and other physiological parameters. Mean number of clamped IC/LA before MEP loss for cranio-caudal clamping direction was 12.8 +/-0.8 for segmental arteries isolated, 9 +/-0.8 if both subclavian arteries were ligated previously and only 4.3 +/- 0.5 IC if the median sacral artery was clamped before. Mean number of clamped LA for caudo-cranial clamping direction was 5.8 +/-0.9 for segmental lumbar arteries, 5.5 +/-0.6 LA if both subclavian arteries were ligated previously and 3.5 +/-0.6 if the median sacral artery was clamped before. CONCLUSION: This study confirms the importance of lumbar and MSA arteries to cord viability. It documents the interaction of the subclavian and MSA (roughly equivalent to the hypogastric arteries in humans) with segmental vessels in providing spinal cord blood supply. It also provides the physiologic basis for use of the pig model for studies of spinal cord protection in aortic surgery.

Animals↗

PubMedDate not supplied

LEA-135 expression: its association with a lower risk of recurrence and increased overall survival of patients with lymph node-positive primary invasive breast cancer.

A retrospective study was undertaken to determine and compare the prognostic significance of LEA-135 protein expression by immunohistochemistry with other prognostic pathological parameters, with respect to recurrence and overall survival. This study was conducted in freshly-frozen tissue sections from a cohort of 367 patients having primary invasive breast cancer, with axillary lymph node metastasis. The association of LEA-135 expression was compared with estrogen and progesterone receptor status, segmentectomy or radical mastectomy and hormonal therapy or chemotherapy in terms of recurrence or disease-free survival. Pathologic parameters including tumor size, histological tumor type and histological grade, as well as age of patients at the time of initial diagnosis, and the treatments, together with a median follow-up of 8.8 years were contemplated for the study. Among these parameters, tumor size and histological grade were individually and significantly associated with an increased probability of recurrence (log rank p<0.001 in both cases) and short survival (log ranks p<0.001 and p=0.002, respectively), whereas age was only significantly associated with an increased probability of recurrence (log rank p=0.002) by univariate analysis. By multivariate analysis, both tumor size and histological grade remained statistically significant for recurrence (log rank p<0.001 and p=0.013, respectively) and overall survival (log ranks p<0.001 and p=0.016, respectively). Among the prognostic biomarkers, both ER and PR expression were associated with a decreased rate of recurrence (log ranks p<0.001 and p=0.008, respectively) and overall survival (log ranks p<0.001 and p=0.002, respectively) by univariate analysis. By multivariate analysis, only the ER expression remained significantly associated with a decreased recurrence and increased overall survival (log ranks p=0.023 and p=0.002, respectively). Patients with high (>50% positive cells) or moderate (5-50% positive cells) number of LEA-135-positive cells had a lower probability (46%) of recurrence at 10 years after surgery compared to 76% in LEA-135-negative patients (log rank p<0.001) by univariate analysis. Moreover, the probability of overall survival was higher in patients with high or moderate expression of LEA-135 (46% and 47%, respectively) compared to LEA-135-negative patients (24%) by univariate analysis (log rank p=0.009). By multivariate analysis, the association remained statistically significant for recurrence (log rank p<0.001) and survival (log rank p=0.002). However, there was no significant association between LEA-135 and any of the pathological parameters, age, hormone receptor status, the mode of surgery or the form of therapy (chemo- and/or hormonal) received by this cohort of patients. The results show that an improved prognosis was directly associated with the density of LEA-135-positive cancer cells, while loss of LEA-135 expression was associated with an aggressive phenotype of cancer cells during breast cancer progression. Thus, LEA-135 expression can be implicated as a significant and independent biomarker to identify and distinguish high- from low-risk patients with lymph node-positive invasive breast cancer for an aggressive treatment. Moreover, according to the present results, LEA-135 expression appears to be associated with the tumor cells that have retained certain normal biological characteristics, leading to their lack of aggressiveness and hence a better prognosis.

Age Factors↗