Biomedical subjects

Y Peng

Publications and source records attributed to Y Peng.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Expression of neural cell adhesion molecule in murine livers with experimental autoimmune hepatitis].

OBJECTIVE: To investigate the expression of neural cell adhesion molecule (NCAM) in murine livers with experimental autoimmune hepatitis (EAH) and its relationship with histological grades. METHODS: To induce the EAH model, the syngeneic S-100 antigen emulsified in complete Freud's adjuvant was injected intraperitoneally to C57Bl/6 at day 1 and day 7. The mice were sacrificed at day 7, 14, and 21 after the first immunization. The expression of NCAM was observed using histoimmunochemistry and RT-PCR. RESULTS: The expression of NCAM increased gradually with aggravation of lymphocyte infiltration and hepatocyte injury. The administration of prednisolone decreased the histological grade, and inhibited the expression of NCAM. There was a correlation between the expression of NCAM and histological grade (r=0.71, P<0.01). CONCLUSIONS: NCAM provides a traffic signal for infiltration of lymphocytes in the liver, hence induces the injury of hepatocytes.

Animals↗

PubMed2001

Application of autologous peripheral blood stem cell transplantation in children with malignant tumor.

OBJECTIVE: To investigate if low dose total body irradiation (TBI, 6.0-9.0 Gy) combined with intensified chemotherapy followed by autologous peripheral blood stem cell transplantation results in better survival in children with refractory leukemia or solid tumors. METHODS: Twenty-one children with malignant tumors were included in this study. There were 14 males and 7 females aged 3.5-12 years. Underlying disease included high-risk acute lymphoblastic leukemia (ALL, CR1 in 3 children and CR2 in 5 children), acute myeloblastic leukemia (AML, 9 children), non-Hodgkin's lymphoma stage IV (2 children), and neuroblastoma stage IV (2 children). The peripheral hematopoietic stem cells were collected six to eleven months after complete response, mobilized with high dose chemotherapy alone or combined with GM-CSF or G-CSF. The conditioning regimen consisted of chemotherapy with two to three combinations of the following drugs: cyclophosphamide, arabinosylcytosine, McNU, etopside, and ldarubicin on the basis of TBI (6.0-9.0 Gy). A mean of (1.8 +/- 0.5) x 10(8)/kg autologous mononuclear cells were transplanted. The patients were followed up after transplantation. RESULTS: Severe bone marrow suppression occurred in all patients around day +7. Peripheral white blood cell count decreased to 0 in all patients at day +4.8 +/- 2.9, and platelet count decreased to less than 20 x 10(9)/L at day +9.0 +/- 2.6. Successful engraftment was achieved in 21 patients, but four died of infection at day +17, +20, +31 and +67, respectively. Recovery of white blood cell (WBC) to 10 x 10(9)/L, absolute neutrophil count to 0.5 x 10(9)/L, platelet count to 20 x 10(9)/L occurred on 21 +/- 12, 26 +/- 13, and 27 +/- 10 days, respectively. During the follow up period, three patients relapsed at months, +1.5 years, and +2 years 10 months, respectively. One patient died of intracranial hemorrhage at +8 months. Thirteen patients had event-free survival for 2-12 years, with a mean of 6.7 +/- 3.4 years. CONCLUSION: Our preliminary data suggest that myeloablative therapy with low dose TBI (6.0-9.0 Gy) combined with intensified chemotherapy followed by autologous peripheral blood stem cell transplantation might be associated with favorable results in children with refractory leukemia or solid tumors.

Child↗

PubMed2001

[Preparation and analysis of pure type II collagen from porcine articular cartilage].

This investigation was aimed at the preparation of pure type II collagen from porcine articular cartilage and the feasible method for producing type II collagen in bulk. After dispersal of the porcine articular cartilage, the proteoglycans were extracted by guanidinium hydrochloride and dissolved by pepsin in acid solvent. The contaminants including denatured and degraded protein and other collagen was removed via the repeated procedure of purification. For obtaining the purer type II collagen, the chromatography with sepharose H. P. Column was also used. The purity of the sample was compared with the type II collagen produced by Sigma Company. Both type II collagens were characterized by SDS-PAGE electrophoresis, amino acid analysis and maximal violet chromatography, and all of the results accorded with the standard photograph in the references. The purity of the sample was higher than that of the product of Sigma Company. This prepared collagen of type II is a product of high purity. The raw materials are the common porcine articular cartilage, which is rich in resource and low in cost. Therefore, it is suitable to produce type II collagen in batches.

Amino Acids↗

PubMed2001

[The effect of lactate-buffered peritoneal dialysis fluid in human peritoneal mesothelial cells function].

OBJECTIVE: To investigate the effect of lactate-buffered peritoneal dialysis fluid (L-PDF) on human peritoneal mesothelial cells (HPMC) function. METHODS: Mesothelial cells from human omentum were isolated and cultured in vitro. Proliferation of HPMC was detected by MTT assay. The quantity of interleukin-8 (IL-8) and fibronectin (FN) in culture supernatants was determined by ELISA. Reverse transcription and polymerase chain reaction amplification were used to detect the expression of IL-8 mRNA in HPMC. Total cellular protein in these supernatants was estimated by using Lowry method. RESULTS: L-PDF inhibited proliferation of HPMC in a time-dependent manner. The levels of IL-8 and FN in the supernatants were remarkably high, and expression of IL-8 mRNA was up-regulated in HPMC exposure to L-PDF. During a subsequent recovery period of 48 hours in culture medium containing lipopolysaccharide (LPS, 10 mg/L), enterotoxin of staphylococcus aureus (10 mg/L) or TNFalpha(10 x 10(6) U/L), the levels of FN in the supernatants increased (P < 0.05). The levels of IL-8 also increased in HPMC stimulated with TNFalpha(P < 0.01). CONCLUSION: L-PDF inhibited proliferation of HPMC and increased levels of IL-8 and FN in the HPMC.

Dialysis Solutions↗

PubMed2001

[Arousals from sleep in patients with obstructive disordered breathing: a comparison study for mechanisms].

OBJECTIVE: To explore the stimuli triggering respiratory arousal. METHODS: Twenty-five patients with excessive daytime sleepiness (EDS) were monitored by nocturnal polysomonography (PSG) and respiratory inductive plethysmography. Patients with obstructive apnea/hypopnea index (AHI) >/= 5/h were diagnosed as obstructive sleep apnea syndrome (OSAS). Patients with Epworth Sleepiness Score >/= 12, frequent inspiratory flow limitation related arousal during sleep and AHI < 5/h were diagnosed as upper airway resistance syndrome (UARS). Seven normal subjects were recruited as controls. RESULTS: Patients with OSAS: AHI (32.8 +/- 19.1)/h, percentage of time spend when oxygen saturation lower than 90% (SLT90%) (11.3 +/- 16.5)%, arousal index (ArI) (35 +/- 17)/h, n = 15. Patients with UARS: AHI (2.5 +/- 1.4)/h, SLT90% (0.1 +/- 0.1)%, ArI (30 +/- 16)/h, n = 10. Normal subjects: AHI (5.9 +/- 4.4)/h, SLT90% (0.2 +/- 0.4)%, ArI (13 +/- 5)/h, n = 7. Though the levels of AHI and SLT90% in patients with UARS were similar to those in normal subjects (H = 2.92, P = 0.87 or H = 0.086, P = 0.77), much lower than those in OSAS patients (H = 12.3, P = 0.000 5 and H = 6.64, P = 0.01), ArI in UARS was just as high as that in OSAS (H = 0.49, P = 0.48). CONCLUSION: Arousals from sleep in patients with obstructive sleep disordered breathing might be mainly caused by inspiratory flow limitation rather than by episodic apnea or desaturation.

Adult↗

PubMed2001

[Effect of temperature, relative humidity and photoperiod on embryonic development and egg hatch of Pirata piraticus].

In this paper, the effects of temperature, relative humidity and photoperiod on embryonic development and egg hatch of Pirata piraticus were investigated. Temperature affected not only the whole course of embryonic development, but also its different phases. At 20 degrees C-35 degrees C, as temperature increased, the embryonic development became faster. The developmental threshold of egg was estimated to be at 11.9 degrees C. The uniform degree of egg hatch was higher at low temperature, while the highest hatching rate was happened at 28 degrees C. In order to study the factors affecting embryonic development and to determine the optimum condition for egg hatch, experiments were arranged by quadratic regression rotation composite design with three factors: temperature (X1), relative humidity (X2) and photoperiod (X3). Three models were built up, and the factors affecting the embryonic development were analyzed. After calculating the hatching rate using the model of hatching rate by computer, the optimum condition for egg hatch of the spider was given: temperature 27 degrees C-28.5 degrees C, relative humidity 94%-97%, and photoperiod 14-17 h.

Animals↗

PubMed2001

[Non-filamentous activated sludge bulking caused by the deficiency of nitrogen].

The effect of nitrogen deficiency on activated sludge bulking was studied specially in some experiments carried on a sequencing batch reactor fed with beer wastewater in this paper. The experimental results showed that the sludge settled properly at a influent BOD/N value of 100/4. When the value of BOD/N was 100/3 and 100/2 respectively, non-filamentous activated sludge bulking caused by an excessive growth of viscous Zoogloea with high moisture content occurred. When the value of influent BOD/N was 100/0.94, more serious non-filamentous bulking occurred. Furthermore, the effect of nitrogen deficiency on the nitrogen sources and phosphorus sources utilization rate and the COD removal rate was studied in the experiments.

Bacteria↗

PubMed2001

[The change in resistance of Pseudomonas aeruginosa to gentamicin during in vitro subculturing].

OBJECTIVE: To observe the change in resistance of Pseudomonas aeruginosa (PA) to gentamicin (GM) during in vitro subculturing. METHODS: Twenty -- six strains of PA with resistance to GM isolated from burn patients were subcultured in vitro for 30 generations. The strains were also divided into high level (20 strains) and medium level (6 strains) of resistant groups according to their MIC (minimum inhibition concentration) values. The MIC and MBC (minimal bactericidal concentration) levels were examined in every strains of the 1st, 10th, 20th, and 30th filial generations of PA strain. RESULTS: There was no significant general difference of MIC and MBC values among the filial generations in each group (P < 0.05) when multiple comparisons of MIC and MBC mean values were made among every filial generations in high and medium levels of GM resistant groups. CONCLUSION: There was no evident difference in GM resistance among all the filial generations of PA. The result indicated that, the PA with different levels of GM resistance clinically found might come from different PA strains.

Anti-Bacterial Agents↗

PubMed2001

[42 years' experience on the prevention and treatment of systemic infection after severe burn].

OBJECTIVE: To summarize the experience of the management of 329 patients with major burn accompanied by severe systemic infection during the past 42 years, so as to help improve the treatment standard. METHODS: One thousand and one hundred twenty seven cases with major burns (TBSA > 50%) were admitted to our hospital during the past 42 years. The incidence of postburn systemic infection and change in the mortality were analyzed in terms of 3 periods, i.e. 1958 to 1980, 1981 to 1990 and 1991 to 2000. RESULTS: Postburn systemic infection developed in 329 out of 1127 cases with the morbidity of 29.4%. The incidences of the infection were 48.5%, 29.3% and 13.1% in the 3 periods, consecutively, with significant differences between them (P < 0.01 similar 0.05). During the 3 periods of past 42 years, the overall cure rate and cure rates in patients with different TBSA increased gradually, especially in those with TBSA Larger than 70%. CONCLUSION: The management of pastburn systemic infection was satisfactorily achieved by early comprehensive clinical measures such as immediate fluid resuscitation, early feeding, appropriate application of antibiotics and early escharectomy en masse, etc. which were established on the basis of experimental results.

Anti-Bacterial Agents↗

PubMed2001

[Clindamycin soluble suppository-production and its efficacy in treating bacterial vaginosis].

OBJECTIVE: To make the soluble suppository of clindamycin which is an effective drug for treatment of Bacterial vaginosis and to treat patients in clinical trials. METHODS: Outpatients who had vaginal infections from Sept. 1998 to Jan. 1999 were investigated. The diagnoses of bacterial vaginosis were made according to Amsel's criteria and 80 patients were included in this study. They were divided into two groups to be treated respectively by metronidanole suppository and clindamycin suppository which were made by our hospital pharmacy. RESULTS: The cure rate of metronidanole was 87.5% and that of clindamycin 90.3%; No significant difference was noted between the two groups(P > 0.05). The new clindamycin suppository was not irritant and it was easy to dissolve in vagina. There was no discontinued treatment because of side-effect. CONCLUSION: The clindamycin suppository does not irritate the mucosa of vagina, it is an efficacious remedy for bacterial vaginosis.

Administration, Intravaginal↗

PubMed2001

[Immediate microcirculation reaction of periodontal ligaments to experimental intrusion of dog teeth].

OBJECTIVE: The purpose of this study is to investigate the immediate microcirculation reaction of periodontal ligaments to experimental intrusion of dog teeth. METHODS: The forth premolar was chosen as the anchor tooth to intrude the second premolar using an intrusion circle loop. All tissue sections were observed and analyzed using the ink perfusion technique and an image analysis apparatus. RESULTS: The microvascular pattern of periodontal ligaments was changed after the maxillary second premolar had been intruded for 2 hours with 100 g of force. The vascular diameter and volume density diminished, but the vascular number and some parts of the microvasculature, especially capillaries were compressed due to the blood escaping from the periodontal ligament. It showed that the initial effect of 100 g of intrusive force caused adaptable changes in the microcirculation of periodontal ligaments, but no significant impediment of blood flow occurred. CONCLUSION: During the tooth intrusion with 100 g of force, a suitable microenvironment was established for the benefit of the survival of periodontal ligaments, which could avoid overloads imposed on the periodontal ligament and decreased the injury of periodontal tissue. It elucidates that the microcirculation of periodontal ligaments plays an important role in the protection of the periodontal tissue, in terms of biological function.

Animals↗

PubMed2001

[A clinical evaluation on reconstruction in extended partial laryngectomy for transglottic cancer].

OBJECTIVE: Transglottic cancer has been a definite indication for total laryngectomy in decades, compromising function of the larynx. The purpose of this study is to present a new radical surgery of extended partial laryngectomy and reconstruction to restore the essential function of larynx. METHODS: Forty-one cases of transglottic cancer were treated by extended vertical laryngectomy (26/41), extended frontolateral laryngectomy (5/41) and subtotal laryngectomy (10/41); the defects of larynx were reconstructed by rotary door myocutaneous flap in twenty-seven cases, by sternohyoideus flap in seven cases, by osteomuscular flap in five cases and by sternocleidomastoid flap in two cases. RESULTS: The 3 and 5 year survival rates were 85.7% (30/35) and 74.1% (20/27) respectively, those for stage III were 84.6% (22/26) and 76.2% (16/21), for stage IV were 3/4 and 1/2 respectively. All cases resumed acceptable voice, 92.7% (38/41) and enjoyed satisfactory phonation. The over-all decannulation rate was 87.8% (36/41), those with rotary door myocutaneous flap was 96.3% (26/27), with sternohyoideus flap was 5/7, with osteomuscular flap was 4/5 and with sternocleidomastoid flap was 1/2. All patients had normal swallow function. CONCLUSION: Extended partial laryngectomy is a kind of radical operation in selected cases of transglottic cancer. The method of reconstruction with rotary door myocutaneous flap can improve curative effect and the essential functions of the larynx.

Adult↗

PubMed2001

[Transmission properties of Faraday anomalous dispersion optical filter at 532 nm].

In this paper the properties of an excited-state potassium Faraday anomalous dispersion optical filter in potassium vapor with a pump wavelength of 769.90 nm (i.e. 4S1/2-->4P1/2 transition) and a signal wavelength of 532 nm (i.e. 4P1/2-->8S1/2 transition) are calculated and discussed. The filter's transmissions versus the laser pump power and the external magnetic-field are obtained. The theoretical results show the transmission characteristics of the filter are relatively insensitive to the laser pump power and magnetic strength. The laser pump powers require range from 0.8 to 6 mW.cm-2. Our model predicts a peak transmission of 50% and an equivalent band-width of 4 GHz for the filter operating on the 4P1/2<--8S1/2 transition in potassium. The optical filter at 532 nm presented in this paper may be used to detect the practical and important frequency-doubled Nd:YAG laser.

English Abstract↗

PubMed2001

[Some spectrum methods on the structures of metal phthalocyanine].

The recent progress in some spectrum methods on the structures of metal phthalocyanine was introduced. IR and UV/Vis spectral properties of phthalocyanine were presented systematically, especially the effect of the types, numbers and positions of the peripheral substituted groups as well as the different aggregation states in solution on the UV/Vis spectra, the characterization method of the isomers of tetra-substituted metal-phthalocyanine by NMR was also discussed.

Indoles↗

PubMed2000

Species-specific TT viruses in humans and nonhuman primates and their phylogenetic relatedness.

By means of polymerase chain reaction with a primer pair (NG133-NG147) deduced from the untranslated region (UTR) of TT virus (TTV), TTVs with markedly distinct genomic lengths were recovered from sera of humans and nonhuman primates, and their entire nucleotide sequences were determined. A human TTV [TGP96 of 2908 nucleotides (nt)] was obtained that was about 900 nt shorter than heretofore reported TTVs (3787-3853 nt). Likewise, TTVs of chimpanzee occurred in two distinct genomic sizes [Pt-TTV6 (3690 nt) and Pt-TTV8-II (2785 nt)]. Two TTVs of Japanese macaque [Mf-TTV3 (3798 nt) and Mf-TTV9 (3763 nt)] were comparable in genomic length, but only 55% similar in sequence. These five human and nonhuman primate TTVs, along with TTVs of tamarin [So-TTV2 (3371 nt)] and douroucouli [At-TTV3 (3718 nt)], were compared over the entire nucleotide sequence. Although the seven TTVs were only < or = 55% similar, they share a common genomic organization with two open reading frames (ORFs), designated ORF1 (654-735 amino acids) and ORF2 (91-152 amino acids). The N-terminal sequences of ORF1 proteins were rich in arginine, and sequence motifs necessary for transcription and replication were conserved among them all. Like the human prototype TTV (TA278), all seven TTVs from various animals possessed in common two 15-nt sequences (CGAATGGCTGAGTTT and AGGGGCAATTCGGGC) in the UTR that were covered by NG133 and NG147, respectively. These primers would be instrumental in research on TTVs in previously unexamined species for defining their virological characteristics and evolutionary relationships.

Amino Acid Sequence↗

PubMed2000

Maternal cold inducible RNA binding protein is required for embryonic kidney formation in Xenopus laevis.

We cloned a major isoform of Xenopus homologue of cold inducible RNA binding protein (CIRP), XCIRP-1. XCIRP-1 was neither cold inducible nor essential for cell division during early embryonic development. Suppression of XCIRP-1 dose dependently produced tailbuds with deformations of the brain and internal organs. The defects were XCIRP-1 specific as they could be rescued by sense transcript. Suppression of XCIRP-1 also disrupted the morphogenetic migration of the C3 blastomeres (lineaged to become the embryonic kidney, the pronephros). In animal cap explants, depletion of XCIRP-1 inhibited activin/retinoic acid induced expressions of pronephros related Xlim-1 and WT1 genes. These results suggest that XCIRP-1 is required for the specification and morphogenetic lineage migration of the pronephros.

Abnormalities, Multiple↗

PubMed2000

Soluble CD8 attenuates cytotoxic T cell responses against replication-defective adenovirus affording transprotection of transgenes in vivo.

The T cell coreceptor, CD8, enhances T cell-APC interactions. Because soluble CD8alpha homodimers can antagonize CD8 T cell activation in vitro, we asked whether secretion of soluble CD8 would effect cytotoxic T cell responses in vivo. Production of soluble CD8 by a replication-defective adenovirus vector allowed persistent virus expression for up to 5 mo in C57BL/6 mice and protected a second foreign transgene from rapid deletion. Soluble CD8 selectively inhibited CD8 T cell proliferation and IFN-gamma production and could also attenuate peptide-specific CD8 T cell responses in vivo. These finding suggest that gene vector delivery of soluble CD8 may have therapeutic applications.

Adenoviridae↗

PubMed2000

Evaluation of L-DOPA biotransformation during repeated L-DOPA infusion into the striatum in freely-moving young and old rats.

The aim of this study was to assess changes in L-3, 4-dihydroxyphenylalanine (L-DOPA) biotransformation in response to two-pulse infusion of L-DOPA into the striatum of freely-moving young (3-4 month) and old (21-26 month) male Wistar rats. In addition, the effects of L-DOPA infusion on the vesicular dopamine (DA) store in young rats were also studied. Both L-DOPA-induced DA overflow and uptake of the perfused L-DOPA by the striatum were used to study L-DOPA biotransformation during microdialysis. High potassium-induced DA depletion was performed to assess the dynamics of the vesicular DA store following L-DOPA infusion. Concentric microdialysis probes were stereotaxically implanted in the lateral striatum of rats of both age groups and microdialysis was begun 24 h later. All rats received 2x20 min infusions of 3 mgr L-DOPA separated by an interval of 60 min. In the striatum of both groups, L-DOPA-induced DA overflow and uptake of exogenous L-DOPA were both significantly enhanced during the second infusion compared to the first. In young rats, when a 20-min infusion of 3 mgr L-DOPA was given between 2x20 min infusions of 100 mM potassium, no increased DA release was seen at the second high potassium challenge compared with the first. Our results suggest that the enhancement of DA overflow induced by the second L-DOPA infusion is, at least partially, due to an increase in L-DOPA biotransformation, and not simply to an enlarged DA pool. In contrast to the in vitro results, our own in vivo results show that L-DOPA utilization in the aging striatum does not deteriorate with age.

3,4-Dihydroxyphenylacetic Acid↗