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Biomedical subjects

Ning Zhang

Publications and source records attributed to Ning Zhang.

At least 109 records · Page 6Linked to original sources
PubMed2004

Mild hypothermia protects the spinal cord from ischemic injury in a chronic porcine model.

OBJECTIVES: During thoracoabdominal aortic aneurysm repair, prolonged compromise of spinal cord blood supply can result in irreversible spinal cord injury. This study investigated the impact of mild hypothermia during aortic cross-clamping on postoperative paraplegia in a chronic porcine model. METHODS: The thoracic aorta was exposed and cross-clamped in 30 juvenile pigs (20-22 kg) for different intervals at normothermia (36.5 degrees C), and during mild hypothermia (32.0 degrees C). Three pigs were evaluated at each time and temperature. Myogenic motor-evoked potentials (MEPs) were monitored, and postoperative recovery evaluated using a modified Tarlov score. RESULTS: There were no significant hemodynamic or metabolic differences between individual animals, and the groups had equivalent arterial pressures (mean 64.3+/-3.6 mmHg). Time to recovery of MEPs correlated with severity of injury; all animals with irreversible MEP loss suffered postoperative paraplegia. At normothermia, animals with 20 min of aortic cross-clamping emerged with normal motor function, but those cross-clamped for 30 min suffered paraplegia. With mild hypothermia, animals tolerated 50 min of aortic cross-clamping without evidence of neurologic injury, but were all paraplegic after 70 min of ischemia. Animals appeared to recover normal motor function after 60 min of aortic cross-clamping at hypothermia initially, but exhibited delayed-onset paraplegia 36 h postoperatively. CONCLUSIONS: Our observations indicate that mild hypothermia dramatically increases the tolerance of the spinal cord to ischemia in the pig, and therefore suggests that cooling to 32.0 degrees C should be encouraged during surgery which may compromise spinal cord blood supply. An ischemic insult of borderline severity may result in delayed paraplegia.

Animals↗
PubMed2004

Aetiology of epilepsy in surgically treated patients in China.

The aim of this retrospective, multicenter clinical study was to evaluate the aetiology of epilepsy in surgically treated patients in China. The detailed clinical records of all intractable partial epilepsy (IPE) were reviewed in five tertiary referral centres from June 1991 to June 2000. 1650 patients (927 males, 723 females) were recruited. 41.4% had aetiological factors, including the histories of major brain trauma (20.9%), febrile seizure (6.5%), meningitis (5.4%), encephalitis (5.0%), prenatal distress (2.1%), birth trauma (0.8%) and family history of seizure (0.7%). The pathological lesions were divided into eight groups according to the nature of the lesion: scar (19.2%), vascular malformations (VM) (17.7%), hippocampal sclerosis (HS) (16.2%), tumours (15.0%), gliosis (12.1%), neuronal migration disorders (NMDs) (7.4%), intracranial infection (4.5%), and other lesions (7.9%). In conclusion, effective management of these aetiological factors and pathological lesions may be essential to deal with IPE. Scar, HS, VM, NMDs are the most likely consequences of antecedent morbid events.

Brain Neoplasms↗
PubMed2004

Primary-consistent soft-decision color demosaicking for digital cameras (patent pending).

Color mosaic sampling schemes are widely used in digital cameras. Given the resolution of CCD sensor arrays, the image quality of digital cameras using mosaic sampling largely depends on the performance of the color demosaicking process. A common problem with existing color demosaicking algorithms is an inconsistency of sample interpolations in different primary color channels, which is the cause of the most objectionable color artifacts. To cure the problem, we propose a new primary-consistent soft-decision framework (PCSD) of color demosaicking. In the PCSD framework, we make multiple estimates of a missing color sample under different hypotheses on edge or texture directions. The estimates are made via a primary consistent interpolation, meaning that all three primary components of a color are interpolated in the same direction. The final estimate of a color sample is obtained by testing different interpolation hypotheses in the reconstructed full-resolution color image and selecting the best via an optimal statistical decision or inference process. A concrete color demosaicking method of the PCSD framework is presented. This new method eliminates certain types of color artifacts of existing color demosaicking methods. Extensive experimental results demonstrate that the PCSD approach can significantly improve the image quality of digital cameras in both subjective and objective measures. In some instances, our gain over the competing methods can be as much as 7 dB.

Algorithms↗
PubMed2004

Sinusoidal modeling of ictal activity along a thalamus-to-cortex seizure pathway I: new coherence approaches.

Understanding associations in neuronal circuitry is critical for tracing epilepsy pathways. Two new methods of measuring coherence between field potentials and EEG channels are proposed for modeling the level of linear association between channels during epileptic seizures. These methods rely upon modeling the repetitive clonic seizure activity as a sum of sinusoids with varying degrees of phase locking. Estimating the amplitude of sinusoids from correlation and cross-correlation time domain data, we can find the coherences from a ratio of these amplitudes. One method utilizes amplitude finding from the multiple signal classification (MUSIC) technique. The other method uses alterations in amplitude of individual sinusoids and their ratios in a matrix pencil equation formed from cross- and auto-correlation matrices. The corresponding generalized eigenvalues of these equations form the coherence ratios. This utilizes the estimation of signal parameters using rotational invariance techniques (ESPRIT) algorithm to arrive at coherence amplitude ratios. Simulations illustrate that the MUSIC method provides better noise immunity as it out-performs the conventional Fourier transform-based method for coherence estimation. Both coherence estimators reflect presence of sinusoidal components that are propagated or not propagated along a particular transmission pathway. We illustrate the value of both methods by examining the strength of correlation between seizure EEG from specific thalamic nuclei and cortex in a rodent model of generalized epilepsy. The pentylenetetrazol (PTZ) chemoconvulsant model in rats reflects selective activation of the anterior thalamic nucleus. Using both methods, this neuronal element has much larger coherence with cortex than another thalamic region, the posterior thalamus (p < 0.05). These methods isolate the unique contribution of anterior thalamus in the formation of an ictal network and corroborate earlier conventional or periodogram techniques.

Algorithms↗
PubMed2004

[In vivo transfection of cis element 'decoy' against nuclear factor-kappaB binding site modulates function of T lymphocytes in asthma].

OBJECTIVE: To investigate the effect of nuclear factor-kappaB (NF-kappaB) decoy oligodeoxynucleotide (ODN) on proliferation, apoptosis and cytokine synthesis of T lymphocytes from asthmatic patients. METHODS: T lymphocytes were divided into four groups, a normal control group (A group), an asthma control group (B group), a NF-kappaB cis decoy ODN group (B(1) group) and a scrambled ODN group (B(2) group). B(1) and B(2) groups were transfected by cationic lipofectamine to the latter two groups respectively. The proliferation of T lymphocytes was measured by MTT and the apoptosis of them was measured by flow cytometry. The expression levels of interleukin 5 (IL-5) mRNA and protein were detected with cell hybridization in situ and enzyme-linked immunosorbent assay (ELISA). The expression levels of inducible nitric oxide synthase (iNOS) were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. RESULTS: The difference of proliferation rate between B(1) group (0.220 +/- 0.020) and B group (0.340 +/- 0.030) was significant (P < 0.05). The difference of apoptosis rate between B(1) group (10.8 +/- 1.3) and B group (8.1 +/- 1.2) was also significant (P < 0.05). The expression levels of IL-5 mRNA and protein in B(1) group (21 +/- 4, 24 +/- 4) were significantly different from those in B group (33 +/- 4, 54 +/- 10, P < 0.05). The differences of iNOS mRNA and protein levels between B(1) group (0.33 +/- 0.05, 782 +/- 117) and B group (0.75 +/- 0.13, 1185 +/- 230) were significant (P < 0.05). However, these indices in B(2) group showed no difference to those in B group (P > 0.05). CONCLUSIONS: NF-kappaB decoy ODN can reduce the abnormally increased proliferation of T lymphocytes in asthma and increase the abnormally decreased apoptosis of these cells, while decrease the abnormally increased levels of cytokine and enzyme in asthmatic T lymphocytes. These may be the mechanisms underlying its potential therapeutic effects in asthma.

Apoptosis↗
PubMed2004

[A cross-sectional study on nonionizing radiation to male fertility].

OBJECTIVE: To investigate the relationship between microwave radiation and male reproductivity. METHODS: After filling out questionnaire and body check, we carried out molecular epidemiological studies, using single cell gel electrophoresis (SCGE) and sperm automatic analysis among people working on radar. RESULTS: Quality of semen and semi-clinical injury of sperm among the people working on radar had changed when radar electromagnetic wave frequency distance, intensity, lasting time and protection shield were changing. Dose-response relationship was noticed and the increase of sperm dysmorphia played a principal role. The results between exposed group and control group showed significant difference (P < 0.01). CONCLUSION: People working on radar who suffered from non-ionization for long time and had bad radar shield protection would show semi-clinical injury on sperm and bad semen quality. However, it did not affect the male reproductive function. It was necessary to reinforce the protection of non-ionization and to improve male reproductive health care of people working on radar.

Adult↗
PubMed2004

[Report of a case of penile epithelioid sarcoma].

OBJECTIVE: To enhance the knowledge and the effect of the diagnosis and treatment of primary epithelioid sarcoma of the penis. METHODS: One rare case of primary epithelioid sarcoma of the penis was studied with regard to its primary clinical process and characteristics, differential diagnosis and method of treatment. RESULTS: An operation was performed on the penis to treat the epithelioid sarcoma. The diagnosis was confirmed by immunohistological and pathological techniques. There was no evidence of relapse during the three-year follow-up after operation. CONCLUSION: The possibility of primary epithelioid sarcoma of the penis should be considered if a mass or induration of the proximal penis and the symptoms of urethremphraxis are found. Total phallectomy could be chosen as an appropriate method of treatment. Unless adenopathy is palpable, node dissections are not recommended.

Adult↗
PubMed2004

[Frequent somatic mutations of the von Hippel-Lindau (VHL) tumor suppressor gene and its meaning in sporadic human renal clear cell carcinoma].

OBJECTIVE: To investigate the mutation of VHL gene, an important tumor suppressor gene in primary sporadic human renal cell carcinoma (RCC) and analyse its relationships with pathological stage and grade of renal cell carcinoma. METHODS: We analyzed 57 cases of primary sporadic Chinese renal clear carcinoma using the polymerase chain reaction (PCR) and denaturing high performance liquid chromatography(DHPLC). All positive cases in DHPLC analysis were further characterized by direct sequencing. RESULTS: Somatic mutations were detected in 30 (53%) of 57 clear cell renal carcinomas including 13 deletions, 2 insertions, and 15 missense mutations. These mutations mainly occurred in the last one-third region of exon 1, 2,and 3. CONCLUSION: VHL tumor suppressor gene is one of the major tumor suppressor genes in human renal cell carcinoma and there are frequent mutations of VHL in primary sporadic Chinese renal clear cell carcinomas. The mutations of VHL gene were irrespective of the age and pathological grade and stage of patients.

Adult↗
PubMed2004

Major hepatectomy without blood transfusion: report of 51 cases.

BACKGROUND: Blood transfusion has been found to be a devastating factor for outcomes of hepatectomy. This study was to assess the value of major hepatectomy without blood transfusion. METHODS: We retrospectively studied 51 patients who had undergone major hepatectomy without blood transfusion, including 29 patients with primary liver cancer, from August 1997 to December 2000. Sixty patients undergoing major hepatectomy with blood transfusion including 48 patients with primary liver cancer served as controls. Hepatectomy was performed through normothermic interruption of the porta hepatis. Intraoperative ultrasonography was performed to define tumor margins, and an ultrasound dissector was used to dissect liver parenchyma. RESULTS: In the study group, the operative mortality and morbidity and 1-, 2-, and 3-year recurrence rates were 0%, 9.8%, 24.1%, 27.6% and 31.0%, respectively. In the control group, they were 3.3%, 28.3%, 43.5%, 54.3% and 58.7%, respectively. Significant differences were seen in morbidity and recurrence rates of patients with liver cancer between the two groups (P < 0.05). CONCLUSION: Major hepatectomy without blood transfusion can reduce postoperative morbidity and recurrence rate of patients with liver cancer.

Adult↗
PubMed2004

[Role of nitric oxide--NF-kappaB signaling pathway in differentiation of human naive T lymphocytes into Th1/Th2 cells].

AIM: To explore the role of nitric oxide (NO)--NF-kappaB signaling pathway in the differentiation of human naive T lymphocytes into Th1/Th2 cells. METHODS: Human naive T lymphocytes were isolated from umbilical blood. Various concentrations of NO donor sodium nitroprusside (SNP), NO inhibitor NAME and NF-kappaB inhibitor PDTC were added to the culture medium to induce the differentiation of naive T cells towards Th1/Th2 cells. The expressions of intracellular cytokine IFN-gamma and IL-4 were detected by flow cytometry. RESULTS: The treatment of SNP, NAME and PDTC made no difference on the percentage of cells expressing IFN-gamma (Th1) or IL-4 (Th2) in comparison with that of the control group (P < 0.05). CONCLUSION: Signaling pathway of NO--NF-kappaB had no effect on differentiation of human naive T lymphocytes into Th1 and Th2 cells. The role of NO--NF-kappaB signaling pathway in the regulation of types 1 and 2 cytokines may occur mainly at the level of mature Th cells.

Cell Differentiation↗
PubMed2004

[Regulatory function of nuclear factor kappa B on lymphocyte proliferation and apoptosis in bronchial asthmatic rats and effect of triptolide on the regulation].

OBJECTIVE: To investigate whether nuclear factor kappa B (NF-kappa B) participates in the regulatory function of lymphocyte proliferation and apoptosis in bronchial asthma and whether the regulatory effect of triptolide on lymphocyte proliferation and apoptosis is conducted through NF-kappa B. METHODS: Intervention with dexamethasone, triptolide and PDTC, a NF-kappa B inhibitor, were used to treat astmatic rats respectively. Pathological examination, airway response were determined, the NF-kappa B P65 expression in lung tissue and splenic lymphocytes by immunofluorescent assay were adopted, proliferative cell nuclear antigen (PCNA) in splenic lymphocytes was measured by immunohistochemistry, apoptosis of splenic lymphocytes were monitored by flow cytometry and NF-kappa B activity was investigated by electrophoresis mobility shift assay (EMSA). RESULTS: The nuclear expression and DNA binding activity of lung tissue and splenic lymphocytes in asthmatic rats were all significantly higher than those in the control (all P < 0.05), so was the proliferation rate of splenic lymphocytes (P < 0.05), while the apoptosis rate was much lower than that of normal control (P < 0.05). Administration of PDTC could reduce the up-regulated expression and activity of NF-kappa B, the proliferation of splenic lymphocytes lowered, while the apoptosis increased. NF-kappa B activity showed an obviously positive correlation with proliferation of splenic lymphocytes (r = 0.89, P < 0.05) and a significantly negative correlation with apoptosis rate (r = -0.54, P < 0.05). After asthmatic rats had been treated with triptolide in vivo, the NF-kappa B nuclear expression and activity in airway and splenic lymphocytes, as well as the proliferation rate of splenic lymphocytes all lowered significantly (all P < 0.05), the apoptosis rate increased significantly (P < 0.05), at the same time, the inflammatory cell infiltration and high reactivity of airway were significantly alleviated (both P < 0.05). There were obviously positive correlation between the amount of airway eosinophils and reactivity with activity of NF-kappa B (r = 0.79 and r = 0.68, P < 0.05), which indicated that the effect of triptolide was not significantly different from that of dexamethasone (P > 0.05). CONCLUSION: (1) NF-kappa B participates the formation of airway inflammation and hyper-reactivity in asthmatic rats by positive regulation on proliferation and negative regulation on apoptosis of lymphocytes. (2) Triptolide reduces airway inflammation by way of inhibiting NF-kappa B, and further inhibiting the proliferation of lymphocytes, so that to give full play of the role of anti-asthmatic airway inflammatory agents. Whether the molecular mechanism of triptolide in inhibiting NF-kappa B simulates that of glucocorticoid needs further studying.

Animals↗
PubMed2004

[Experimental study on effect of erzhi tiangui recipe on quality of oocyte in mice].

OBJECTIVE: To observe the effect of Erzhi Tiangui recipe (ETR) on quality of oocyte in the process of external fertilization and embryo-transplantation. METHODS: Eighty mice were randomly divided into 4 groups, Group A treated with ETR plus human menopausal gonadotropin (HMG), Group B with ETR, Group C with HMG and Group D with normal saline. Ovulation test and cleavage test were conducted to observe the effect of treatment on quality of oocytes. RESULTS: The difference on ovulation number between Group A and C was insignificant, but the difference in comparison between the two groups was significant in aspects of oocyte morphological scoring, fertilization rate and cleavage rate (P<0.05). CONCLUSION: ETR could play its effect synergistically with Western medicine, and raise the quality of oocytes.

Animals↗
PubMed2004

[A new applicator with regulatable air bag designed for intracavitary brachytherapy of nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Nasopharynx applicator used in intracavitary brachytherapy plays an important role in the radiotherapy of nasopharyngeal carcinoma (NPC), its quality affects the efficiency of treatment. This study was to design a new applicator for clinical use. METHODS: An inexpensive, reusable, and flexible latex nasopharynx applicator was designed. An air bag was placed at 15 mm from the foreside of the applicator, clung to the tube. The edge of air bag is tangent to the axis of tube. When the bag was full of air, the tube would hunch reversely,close to nasopharyngeal vault. After introduced into nasopharynx through middle nasal meatus, the applicator could be fixed in suitable position by its rotation, and air bag regulation, and confirmed its position by simulation. RESULTS: A total of 221 patients with NPC were treated with external beam radiation therapy in our hospital, and boosted HDR brachytherapy using this new applicator. The response rate was 92.6% in the primary tumor group (200/216), and 100% in the recurrent tumor group (5/5). Mucosal necrosis in the posterior or anterior wall of nasopharynx occurred in 5 patients, 8 patients experienced nasal congestion and nasal synechia. CONCLUSIONS: This new nasopharynx applicator is easy to operate, painless, and well dosage-distributed. Mucosal necrosis is likely due to higher fractional dose.

Adolescent↗
PubMed2004

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

OBJECTIVE: To establish orthotopically transplanted model of human malignant small intestinal lymphoma in nude mice and analyze their biologic characteristics. METHODS: Small intestinal lymphoma tissues from 5 patients were transplanted into intestinal mucosa of nude mice. Tumorgenecity, invasion and metastasis of the transplanted tumors were observed by morphological analyses (light microscopy, electron microscopy and immunohistochemistry), karyotyping and DNA quantitative assay. RESULTS: Tumor tissues from 3 lymphoma patients were successfully transplanted. According to the World Health Organization classification, the three models were classified into non-Hodgkin's lymphoma (B cell) of human small intestine (HSIL-1), high metastasis of non-Hodgkin's lymphoma (B cell) of human small intestine (HSIL-2) and non-Hodgkin's lymphoma (T cell) of human small intestine (HSIL-3), respectively. Immunohistochemistry showed that CD19, CD20, CD22, CD40, CD45 and CD72 were positive in HSIL-1 and HSIL-2, whereas CD3, CD7 and CD45RO were positive in HSIL-3. The karyotypes of the transplanted tumors were all hypotriploid with modal numbers from 55 to 69 and the DNA index (DI) was 1.46 approximately 1.71. The three models had been passaged for 32, 27 and 21 generations respectively in 433 nude mice. The growth rate, resuscitation rate of the liquid nitrogen preserved tumor cells and spontaneous metastasis rate upon transplantation were all 100%. We observed an invasive growth of the transplanted tumors in small intestine, which resulted in disrupting of the intestinal wall, hematogenous metastasis, lymph node metastasis and seeding metastasis. The features of the transplanted tumors were similar to the original tumors in histopathology, ultrastructure, DNA content and karyotype. CONCLUSION: Three strains of orthotopically transplanted model of human primary malignant small intestinal lymphoma in nude mice were successfully developed. The result of research will provide ideal animal models for further studies on mechanism of tumorigenesis, invasion and metastasis of malignant small intestinal lymphoma and experimental therapy.

Adult↗
PubMed2004

[Comparison study on therapeutic effects of anterior approach versus posterior approach in treating multilevel cervical disc herniation].

OBJECTIVE: To investigate the therapeutic effects of anterior approach set (AAS) versus posterior approach set (PAS) in treating multilevel cervical disc herniation of three or four segments. METHODS: Fifty-six cases of multilevel cervical disc herniation were retrospectively studied. Thirty-seven cases underwent anterior approach, and discectomy, selectively partial corpectomy with bone grafting and plate fixing was performed (AAS group); 19 cases underwent posterior approach, and laminectomy with lateral cervical mass plate screw fixing was performed (PAS group). RESULTS: The follow-up periods were 6 months to 4 years and 5 months, averaging 2 years and 10 months in AAS group and 1 year and 5 months to 5 years and 1 month, averaging 3 years and 8 months in PAS group. JOA functional assessment and sagittal diameter of dural sac were not statistically significant between two groups before operation (P>0.05) and were significantly larger in AAS group than in PAS group after operation (P<0.01). The improvement rate of AAS was significant higher than that of PAS (P<0.01). The number of complication in AAS were slight more than that in PAS. CONCLUSION: AAS is obviously better than PAS in the therapeutic effects. The operation of anterior decompression with bone grafting and plate fixing is an indication of multilevel cervical disc herniation of three or four segments.

Adult↗
PubMed2004

[Immunogenicity analysis of HIV vaccine based on replicating vaccinia virus Tiantan vector].

OBJECTIVE: To investigate the immunogenicity of HIV vaccine vTKgpe based on Vaccinia Virus Tiantan vector in mice and rabbits. METHODS: Mice were inoculated with HIV vaccine vTKgpe by intramuscular (i.m.), intradermal (i.d.) or subcutaneous (s.c.) injections. Blood sample were collected every week, and then antibodies against HIV and vaccinia virus vector were detected. At week 4, some mice were killed and cellular immune responses were examined by flow cytometer. Additionally two rabbits were vaccinated subcutaneously, blood sample were tested as done with mice. RESULTS: In mice i.m. and s.c. groups, HIV specific antibodies emerged at week 2 and declined at week 4. Antibodies against vector elevated rapidly at week 4, and potentially affected HIV specific antibody detection. Cellular immune responses were only detected in s.c. group. Serum of rabbit showed that anti-HIV antibody appeared at week 2 and maintained for several weeks. CONCLUSION: Vaccine vTKgpe innoculated by i.m. and s.c routes inclined to induce humoral immune responses in mice, but in i.d. group, inclined to induce cellular immune responses. Response to the recombinant vaccinia virus was more sensitive in rabbit than in mice.

AIDS Vaccines↗
PubMed2004

[Studies on HPLC fingerprints of tanshinone microemulsion].

OBJECTIVE: To establish the HPLC fingerprints of tanshinone microemulsion. METHOD: HPLC analysis was carried on Hypersil C18(4.6 mm x 250 mm, 5 microm) analytical column; the acetonitrile and 0.5% phosphoric acid solution were used as mobile phases with gradient elution at a flow rate of 1.0 mL x min(-1). The UV detection wavelength was set at 270 nm. RESULT: Six peaks on HPLC fingerprint of Tanshinone Microemulsion are indexed. CONCLUSION: The method developed in the present study is convenient, reliable, and can be used as a quality control method for Tanshinone Microemulsion.

Abietanes↗