Search PubMed⌕ Search

Biomedical subjects

L Zhu

Publications and source records attributed to L Zhu.

At least 127 records · Page 7Linked to original sources
PubMed2001

Cloning and characterization of G protein-gated inward rectifier K+ channel (GIRK1) isoforms from heart and brain.

A G protein-gated inward rectifier potassium (K+) channel (GIRK1a) has been cloned from different tissues (Kubo et al., 1993b; Dascal et al., 1993). Here we report the cloning of three additional novel isoforms of GIRK1a from rat atria and and one from human brain. These isoform cDNAs code for proteins that have identical N-termini, M1-H5-M2 (predicted transmembrane and pore domains), and post-M2 amino acid regions to GIRK1a (1-501 amino acids), but they have shorter C-termini (GIRK1b (1-309), GIRK1c (1-308), GIRK1d (1-235), and GIRK1e (1-253). These results indicated that isoforms were generated by alternative splicing and partial genomic analysis confirmed the presence of exons and introns in the rat GIRK1 gene. RNase protection analysis and immunoblot analysis indicated that the isoforms were expressed in both rat atria and brain but at lower levels versus GIRK1a. The physiological role that the isoforms may play in atrial and brain physiology remains to be determined.

Alternative Splicing↗
PubMed2001

[The survey of polycyclic aromatic hydrocarbons in a habitation air in Hangzhou].

The twelve polycyclic aromatic hydrocarbons(PAHs) were detected in a habitation air air of Hangzhou. The results indicated that the concentrations of PAHs in the habitation air were between 8.237 micrograms/m3 and 14.234 micrograms/m3. The habitation air was seriously polluted by PAHs. The main source of PAHs in the habitation air was from cooking and burning. And the waste gases from vehicular will contribute to it also.

Air Pollutants↗
PubMed2001

[Histopathology and immunohistochemical expression of precursor lesions of cervical adenocarcinoma].

OBJECTIVE: To discuss the histopathology and immunohistochemical expression in precursor lesion of cervical adenocarcinoma-cervical intraepithelial glandular neoplasia (CIGN). METHODS: Histopathological examination and immunohistochemical study (SP method) were performed on 101 cases of CIGN. RESULTS: Criteria for histological grading of CIGN into three degrees, grade I to III, were proposed according to the hyperchromasia and the stratification of nuclei, number of mitoses and the amount of intracellular mucin. Adenocarcinoma in situ was classified as CIGN-III. 46.53% (47/101) CIGN showed a co-existence of CIN (SIL). 45 cases were CEA positive (44.55%) and 38 showed apical and luminal positivity. The positive rate of PCNA was 63.54% and was 100% in CIGN-III. The positive rate of ER was 81.48% (66/81). The expression of ER was often decreased or missing in certain cases. The positive rate of HPV 6/11 in CIGN I-III was 34.09% (30/88), 31.82% (28/88), and 3.41% (3/88), respectively. CONCLUSIONS: Histological grading of CIGN is important. Immunohistochemical staining for CEA, PCNA and ER may be helpful in diagnosis and differential diagnosis of CIGN.

Adenocarcinoma↗
PubMed2001

[Repetitious sorption of phenol to organobentonites from water].

The properties and mechanisms for repetitious sorption of phenol to organobentonites from water were studied. Results showed that organobentonites could be used to sorb phenol from water many times with high removal rates. The sorption capacities of three single-cation organobentonites were 120 CTMAB-bentonites > 120 CPC-bentonites > 120 DTMAB-bentonites, when the original concentration of phenol was 1000 mg/L. The sorption mechanisms changed from adsorption to partition in the process of repetitious sorption. Sorption of phenol to CPC-bentonites could bring synergic sorption. The distribution coefficience (Kp) were related to the quantities of phenol on CPC-bentonites, while the distribution coefficience of phenol on CTMAB-bentonites and DTMAB-bentonite were constant.

Adsorption↗
PubMed2001

Low incidence of severe aGVHD and accelerating hemopoietic reconstitution in allo-BMT using lenograstim stimulated BM cells.

OBJECTIVES: To investigate the efficacy of accelerating hemopoietic reconstraction and reducing a graft versus host disease (GVHD) in Allo-BMT receiving lenograstim stimulated donor marrow and to assess the preliminary biological mechanism. METHODS: The donors for thirty patients (study group) with leukemia were given lenograstim 3-4 micrograms.kg-1.d-1 for seven days prior to marrow harvest. The results of subsequent engraftment in the recipients was compared with fifteen donors without G-CSF (control group). Five donors themselves were studied to assess the effects of lenograstion on hematopoietic progenitor cells and lymphocyte subsets in BM. RESULTS: The stimulated bone marrow contained a higher number of nucleated cells, CFU-GM and CD34+ cells (P < 0.01). The hematopoetic reconstitution was accelerated. Until granulocyte counts exceeded 0.5 x 10(9)/L and plalete counts exceeded 20 x 10(9)/L, the days were 16.7 +/- 3.2 and 18.4 +/- 3.0 days as compared with those of the control group (22.5 +/- 5.1 and 26.3 +/- 5.9 days respectively, P < 0.01). The incidence of grade II-IV aGVHD was very low, only one case with grade II aGVHD on the skin in the study group. Four out of fifteen patients (26.7%) in the control group had grade II-IV aGVHD (P < 0.05). The number of T lymphocyte subsets in the harvested BM stimulated by G-CSF changed. In comparison with the control group, CD4+ decreased and CD8+ increased significantly (P < 0.01). The changes of progenitor cells and T lymphocyte subsets in BM from pre- to post-G-CSF stimulation indicated that the percentage of CD4+ cells reduced (P < 0.05), that of CD8+ cells, and that of CD34+ increased (P < 0.01). The incidence of chronic GVHD and relapse of leukemia were not different significantly between both groups. CONCLUSIONS: Allogenic bone marrow transplant (Allo-BMT) donors given G-CSF can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favour of improved transplant-related complications.

Acute Disease↗
PubMed2001

[Mobilization of autologous peripheral blood stem cells by combined chemotherapy and rhG-CSF].

OBJECTIVE: To study the effect of cyclophosphamide (CTX) combination chemotherapy and recombinant human granulocyte colony-stimulating factor (rhG-CSF) on autologous peripheral blood stem cells (APBSC) mobilization. METHODS: CTX(2.5 +/- 1.0) g/m2 on day 1, VP-16,600-800 mg and/or Ara-C 1.0-2.0 g/m2 on day 2 were injected i.v. rhG-CSF 300 micrograms/d was injected s.c. when the white blood cell (WBC) count reached nadir until one day before APBSC harvest. When the WBC count was over 3.0 x 10(9)/L, peripheral blood mononuclear cell (MNC) collection was performed once per day until the number of MNC collected was > 4 x 10(8)/kg. CFU-GM colony formation and CD34+ cell enumeration were performed. RESULTS: Twenty cases were studied. The lowest level of WBC was (1.2 +/- 0.8) x 10(9)/L on day 8.5 +/- 1.5 following chemotherapy. rhG-CSF was given from day 9.0 +/- 2.0 and continued for 6.0 +/- 1.0 days. APBSC harvest began on day 12.0 +/- 2.0 and continued for 4.0 +/- 1.0 days. A total of (6.14 +/- 2.34) x 10(8)/kg MNC and (23.25 +/- 30.56) x 10(6)/kg CD34+ cells was procured. Peak level of CD34+ cells was observed 14.6 +/- 1.8 days after chemotherapy and 4.9 +/- 1.6 days after rhG-CSF administration. CFU-GM was (21.68 +/- 15.39) x 10(4)/kg when rhG-CSF was given for 4.9 +/- 1.6 days. No severe toxic reaction was observed. Hematopoietic reconstitution was very well in all patients received APBSC transplantation. CONCLUSION: CTX combination chemotherapy followed by rhG-CSF was safe and feasible for APBSC mobilization.

Adolescent↗
PubMed2001

[A comparison of the effects of PAV, PSV and IPPV on cardiopulmonary function in patients with acute respiratory failure].

OBJECTIVE: Comparing the effects of proportional assist ventilation (PAV), pressure support ventilation (PSV), and intermittent positive pressure ventilation (IPPV) on cardiopulmonary function in patients with acute respiratory failure, in particular, evaluating the clinical significance of PAV. METHODS: Ten patients with acute respiratory failure were firstly ventilated with IPPV. Elaslance (Ers) and Resistance (Rrs) were measured and calculated. Then PSV mode was adapted. Based on the parameters of IPPV, inspiratory positive airway pressure was adjusted to maintain the same tidal volume (V(T)) as that in IPPV. Finally PAV mode was used. According to the parameters of PSV, the assist ratio was adjusted to maintain the same V(T) and peak pressure peak, as those in PSV. Respiratory mechanics, arterial blood gas and hemodynamics were recorded during above three modes of ventilation. RESULT: Comparing with PSV and IPPV mode, PAV created a significantly lower peak, less work of breathing of patients (WoBp) and work of breathing of ventilation (WoBv) under the similar V(T); Central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) were significantly lower in PAV mode as compared with those in IPPV; While comparing with PSV, V(T), mean blood pressure (mBP) and cardiac output (CO) were higher and mean pulmonary arterial pressure (mPAP), WoBp were lower in patients with PAV under similar peak. Among them the fall of WoBp was statistically significant. CONCLUSION: In patients receiving three modes of ventilation, PAV presents with lower airway pressure, less WoBp and less effect on hemodynamics as compared with those with PSV or IPPV.

Acute Disease↗
PubMed2001

[Sources analysis and contribution identification of polycyclic aromatic hydrocarbons in indoor and outdoor air of Hangzhou].

Twelve polycyclic aromatic hydrocarbons (PAHs) were measured in eight homes in Hangzhou during the summer and autumn in 1999. The sources of PAHs and the contributions of the sources to the total concentration of PAHs in the indoor air were identified by the combination of correlation analysis, factor analysis and multiple regression, and the equations between the concentrations of PAHs in indoor and outdoor air and factors were got. It was indicated that the factors of PAHs in the indoor air were domestic cuisine, the volatility of the mothball, cigarette smoke and heating, the waste gas from vehicles. In the smokers' home, cigarette smoke was the most important factor, and it contributed 25.8% of BaP to the indoor air of smokers' home.

Air Pollutants↗
PubMed2001

[Clinical pathological analysis of adenomatoid tumor in uterus and ovaries].

OBJECTIVE: To study the immunohistochemical feature and the differential diagnosis of adenomatoid tumors in uterus and ovaries. METHODS: Clinical pathological analysis and immunohistochemical studies were performed on 24 cases of adenomatoid tumors in the uterus and ovaries. RESULTS: Of the 24 cases, 21 cases were in the uterus, 2 cases in the ovaries and 1 cases in both the uterus and the ovary. Grossly, the mean diameter of the 22 uterus tumors was 2.2 cm, ranging from 0.2 - 5.5 cm. 14 (63.6%) were located in the subserosa or near by the subserosa of the uterine cornua. The other 8 tumors located in the myometrium. The cut surface presented a nodular pattern with grayish white or yellowish in color, partially cystic. 3 ovarian tumors became all cystic, without a clear-cut margin from the surroundings. Microscopically, the tumor consisted of various gland-like structure or luminal spaces lined with flat, cuboidal or low columnar cells, similar to blood vessels in structure. Among the tumor cells, there were scattered vesicular cells with large or small vacuoles, but no nuclear atypia and mitotic figures detected. Immunohistochemical staining showed the tumor cells positive for vimentin, AE(1)/AE(3) and calretinin, but negative for F VIII-Rag. S-100 and EMA were positive in 20 (83.3%) and 4 (16.7%) cases respectively. CONCLUSION: Adenomatoid tumor of the female genital tract is mesothelial in origin and uterus was considered as the most common site of occurance. Immunohistochemical phenotypes can be used as an important evidence for differential diagnosis. The biological behavior of adenomatoid tumor is benign and with a good prognosis.

Adenomatoid Tumor↗
PubMed2001

[Cloning of trehalose-6-phosphate synthase gene from S. cerevisiae and its plant expression vector construction].

Total RNA, mRNA were isolated from baker's yeast S. cerevisiae, the cDNA was prepared with AMV Reverse Transcriptase from the total mRNA. The gene of trehalose-6-phosphate synthase was cloned from the cDNA with PCR amplification. The gene was sequenced and the results showed that the tpsl gene contains 1507 nucleotides and 99.6% identity with S. cerevisiae. The tps1 gene was constructed on the plant expression vector pBin438.

Base Sequence↗
PubMed2000

Oxidative stress due to hypoxia/reoxygenation induces angiogenic factor VEGF in adult rat myocardium: possible role of NFkappaB.

INTRODUCTION: Oxidative stress, as exerted by free radicals within biological systems, is known to exert numerous physiological and pathological effects on the cardiovascular system. Short-term exposure to environmental conditions such as low oxygen tension can cause such oxidative stress in vivo through inhalational hypoxia/reoxygenation. In this report the effects of different durations of hypoxia were investigated on myocardial protein expression of vascular endothelial growth factor (VEGF). a major angiogenic growth factor, and also explore the possible modulatory role of transcription factor NFkappaB on such expression. METHODS: Forty eight male Sprague-Dawley rats (300 g b.w.) were randomly divided into four groups and subjected to either 1, 2 or 4 h of systemic normobaric hypoxemic hypoxia (10+/-0.4% O2) in an anesthesia chamber, or to 4 h of normoxia (ambient 20.9+/-0.4% O2) to time-match the maximal hypoxic duration. All rats were then kept under normoxic conditions. Rats were sacrificed and hearts harvested either after 2 h for later electrophoretic mobility gel shift assay for NFkappaB, or after 24 h for later Western blot analysis for VEGF. RESULTS: Western blot analysis for VEGF revealed significantly elevated protein expression (2.4-fold compared to baseline control) in the I h group. This elevated level persisted in the 2 and 4 h groups as well. Two hours post-hypoxia gel shift assay for NFkappaB indicated significant nuclear translocation and DNA binding of this transcription factor in the 1 and 2 h groups, with moderate decrease in the 4 h group. CONCLUSION: In vivo oxidative stress caused by systemic inhalational hypoxemic hypoxia increases cardiac VEGF protein expression and may trigger myocardial angiogenesis. The results suggest that NFkappaB modulates such an effect.

Animals↗
PubMed2000

Caveolin-1 expression is down-regulated in cells transformed by the human papilloma virus in a p53-dependent manner. Replacement of caveolin-1 expression suppresses HPV-mediated cell transformation.

Squamous cell carcinomas of the lung and cervix arise by neoplastic transformation of their respective tissue epithelia. In the case of cervical carcinomas, an increasing body of evidence implicates the human papillomavirus, HPV (types 16 and 18), as playing a pivotal role in this malignant transformation process. The HPV early genes E6 and E7 are known to inactivate the tumor suppressors p53 and Rb, respectively; this leads to disruption of cell cycle regulation, predisposing cells to a cancerous phenotype. However, the role of caveolin-1 (a putative tumor suppressor) in this process remains unknown. Here, we show that caveolin-1 protein expression is consistently reduced in a panel of lung and cervical cancer derived cell lines and that this reduction is not due to hyperactivation of p42/44 MAP kinase (a known negative regulator of caveolin-1 transcription). Instead, we provide evidence that this down-regulation event is due to expression of the HPV E6 viral oncoprotein, as stable expression of E6 in NIH 3T3 cells is sufficient to dramatically reduce caveolin-1 protein levels. Furthermore, we demonstrate that p53-a tumor suppressor inactivated by E6-is a positive regulator of caveolin-1 gene transcription and protein expression. SiHa cells are derived from a human cervical squamous carcinoma, harbor a fully integrated copy of the HPV 16 genome (including E6), and show dramatically reduced levels of caveolin-1 expression. We show here that adenoviral-mediated gene transfer of the caveolin-1 cDNA to SiHa cells restores caveolin-1 protein expression and abrogates their anchorage-independent growth in soft agar. Taken together, our results suggest that the HPV oncoprotein E6 down-regulates caveolin-1 via inactivation of p53 and that replacement of caveolin-1 expression can partially revert HPV-mediated cell transformation.

3T3 Cells↗
PubMed2000

Changes in the apparent diffusion coefficient of water and T2 relaxation time in gerbil hippocampus after mild ischemia.

Selective neuronal death of the hippocampal CA1 area after mild ischemia is known as delayed neuronal death (DND). Progression of DND was evaluated using 7T MRI in gerbils. In the CA1, the T2 relaxation time started to increase on day 3 and was significantly higher on day 4 than that of the control gerbils. However, the apparent diffusion coefficient of water (ADC) was significantly lower on day 1 than in the control and continued to decline up to day 4. Changes in T2 coincided with loss of MAP2 immunoreactivity, while the ADC decrease preceded these changes. After 1 month, the ADC had returned to within the normal range, while T2 had decreased to below the control level. These results suggest that MRI is useful for monitoring DND.

Animals↗
PubMed2000

Refinement of the locus for autosomal dominant hereditary gingival fibromatosis (GINGF) to a 3.8-cM region on 2p21.

Hereditary gingival fibromatosis (HGF, MIM 135300; approved gene symbol GINGF) is an oral disease characterized by enlargement of gingiva. Recently, a locus for autosomal dominant HGF has been mapped to an 11-cM region on chromosome 2p21. In the current investigation, we genotyped four Chinese HGF families using polymorphic microsatellite markers on 2p21. The HOMOG test provided evidence for genetic homogeneity, with evidence for linkage in four families (heterogeneity versus homogeneity test HOMOG, chi(2) = 0. 00). A cumulative maximum two-point lod score of 5.04 was produced with marker D2S390 at a recombination frequency of &theta; = 0 in the four linked families. Haplotype analysis localized the hereditary gingival fibromatosis locus within the region defined by D2S352 and D2S2163. This region overlaps by 3.8 cM with the previously reported HGF region. Single-strand conformation polymorphism and sequence analysis of the coding region of cytochrome P450 1B1 (CYP1B1) excluded it as a likely candidate gene.

Aryl Hydrocarbon Hydroxylases↗
PubMed2000

Direct observation of a breit-wigner phase of a wave function

The Breit-Wigner phase of a wave function was obtained by measuring the interference between two independent ionization paths of a molecule. The state of interest was present in only one of the paths, thereby producing a phase shift in the observed signal. An analytical theory was used to determine the phase of the wave function from the observable.

Journal Article↗
PubMed2000

Thermal stable and oxidation-resistant variant of subtilisin E.

A remarkable thermal stable and oxidation-resistant mutant was obtained using the random mutagenesis PCR technique on the mutant M222A gene of subtilisin E. Sequencing analysis revealed an A was replaced by G at nucleotide 671 of the subtilisin E gene, converting the asparagine codon (AAT) to serine codon (AGT) at position 118. The half-life of M222A/N118S enzyme activity, when heated at 65 degrees C, was approximately 80 min while the half-life of M222A and wild-type subtilisin E were 13 min and 15 min, respectively. This suggested the stability of the M222A/N118S mutant was five times greater than that of the wild-type enzyme. The mutant was also as oxidation resistant as the mutant M222A of subtilisin E. These results indicated the M222A/N118S mutant is both an oxidation-resistant and a heat-stable variant of subtilisin E.

Amidohydrolases↗
PubMed2000

Gene expression networks underlying retinoic acid-induced differentiation of acute promyelocytic leukemia cells.

To elucidate the molecular mechanism of all-trans-retinoic acid (ATRA)-induced differentiation of acute promyelocytic leukemia (APL) cells, the gene expression patterns in the APL cell line NB(4) before and after ATRA treatment were analyzed using complementary DNA array, suppression-subtractive hybridization, and differential-display-polymerase chain reaction. A total of 169 genes, including 8 novel ones, were modulated by ATRA. The ATRA-induced gene expression profiles were in high accord with the differentiation and proliferation status of the NB(4) cells. The time courses of their modulation were interesting. Among the 100 up-regulated genes, the induction of expression occurred most frequently 12-48 hours after ATRA treatment, while 59 of 69 down-regulated genes found their expression suppressed within 8 hours. The transcriptional regulation of 8 induced and 24 repressed genes was not blocked by cycloheximide, which suggests that these genes may be direct targets of the ATRA signaling pathway. A balanced functional network seemed to emerge, and it formed the foundation of decreased cellular proliferation, maintenance of cell viability, increased protein modulation, and promotion of granulocytic maturation. Several cytosolic signaling pathways, including JAKs/STAT and MAPK, may also be implicated in the symphony of differentiation. (Blood. 2000;96:1496-1504)

Antineoplastic Agents↗