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Biomedical subjects

B Luo

Publications and source records attributed to B Luo.

At least 55 records · Page 3Linked to original sources
PubMed1998

[A prospective study on etiologic bacteria in 200 patients with pneumonia].

The etiologic agents in 200 patients with pneumonia were studied by the bacterial culture of sputums obtained from the protected single catheter brush or quantitative expectoration at one morning or three-morning expectoration. Two hundred patients were divided into 3 groups. Group 1 was Nosocomial pneumonia (NP patients). Group 2-1 and Group 2-2 were community acquired pneumonia (CAP patients). All cases in Group 1 and Group 2-2 suffered from significant underlying diseases while Group 2-1 did not. Gram-negative bacilli(GNB) were isolated from the specimens in Group 1 (87%) and Group 2-2 (75%), respectively. Pseudomonas (30.8%) and klebsiella (20.5%) were the predominant bacteria (in Group 1 and pseudomonas bacteria) in Group 1 and pseudomonas (27.3%), acinetobacter (23%) and kledsiella (18%) were the major etiologic agents in Group 2-2. The commonest pathogens in Group 2-1 were gram-positive cocci (75%), in which streptococcus (38%) and staphylococcus aureus (25%) were the dominant agents. Compared with Group 2, Group 1 suffered from more mixed bacteria and the agents presented severer drug-resistant. The prognosis was worse in Group 2-2 than in Group 2-1. The results showed that the GNB pneumonia was more common in the cases who had underlying disease, no matter whether the pneumonia was NP or CAP. These patients had more trouble on their antibiotic therapy. Thus it is important that doctors should use vigorous antibiotics timely while treating these patients' underying diseases.

Adult↗
PubMed1998

[VP-16 and VM-26 plus platinum drugs combined with radiotherapy in the treatment of small cell lung cancer].

OBJECTIVE: To compare the clinical efficacy of VP-16(etoposide) with VM-26(teniposide) both plus platinum drugs combined with radiotherapy in the treatment of patients with small cell lung cancer(SCLC). METHODS: Seventy-four cases of SCLC were studied retrospectively. Forty-three patients were treated with VP-16 + DDP + CTX or VP-16 + DDP, the other 31 patients were treated with VM-26 + DDP or VM-26 + Carboplatin. The treatment of both groups was combined with radiotherapy. RESULTS: There was no significant difference between VP-16 and VM-26 groups in response rate, 2-year-survival rate, and brain metastasis rate. But the blood toxicity was more serious in VM-26 group than in VP-16 group; 3-4 stage toxicity rate was 58.06% versus 27.91%. CONCLUSION: The results indicate that both VP-16 and VM-26 combined with platinum drugs were effective chemotherapy protocols. The authors suggest choosing VP-16 protocols as the first choice for previously untreated SCLC patients.

Adult↗
PubMed1998

[Morphological observations of tumors in the cardiac conduction system].

OBJECTIVE: To investigate the incidence of tumors in the cardiac conduction system (CCS) and to study their relation to sudden deaths. METHODS: The CCS from 149 cases of sudden death without extracardiac cause of deaths and those from 737 cases of non-cardiac death were sampled using technique designed by the authors. Routine histological examinations were carried out. RESULTS: Tumors in the CCS were found in 12 cases (1.35%). Another case with tumor in the CCS was found in a specimen received for consultation. Of these 13 tumors, 10 were primary benign tumors affecting the CCS, 3 were metastatic tumors. The benign tumors included fibroma, hemangioma, lipomatous hypertrophy of the atrial septum, mesothelioma and rhabdomyoma. 8 of the 10 cases were located in the SAN or AVN. All the metastatic tumors were in the SAN. Of the 13 cases, 3 died suddenly. CONCLUSION: Tumors in the CCS are the smallest tumors which can cause sudden death.

Adolescent↗
PubMed1998

[Diagnosis and treatment of tuberculous appendicitis].

OBJECTIVE: To study the diagnosis and treatment of tuberculous appendicitis. METHOD: 12 cases (0.26%) with tuberculous appendicitis diagnosed by histopathological examination selected from 4,652 patients during 1968 to 1997 were analysed retrospectively. RESULT: The mean age of the patients with tuberculous appendicitis was 35 years, the disease occurred 2 times more frequently in women than in men and was usually secondary to tuberculosis elsewhere in the body (7 cases). There were 7 cases with proliferative lesions, 3 cases with ulcerative lesions and 2 cases with two kinds of lesions. 12 cases were all misdiagnosed preoperatively, 2 cases were diagnosed definitely in the operation. In 12 cases, 7 cases underwent simple appendectomy, 2 cases partial celectomy and 1 case right hemicolectomy, appendectomy and resection of regional lymph nodes were performed on 2 cases, treatment of anti-TB was given postoperatively to 9 patients. All the patients recovered without complications. CONCLUSION: It's hard to get definite diagnosis of tuberculous appendicitis before operation because of low incidence and non-specific clinical manifestations, so careful observation in the operation and routine histopathological examination must be emphasized. Early operation and postoperative treatment of anti-TB should be advocated in order to prevent from complications.

Adult↗
PubMed1998

[Immunohistochemical study on ANP in the atria of electrocution].

By the immunohistochemical staining for ANP with LSAB method and the analysis of areas and grays of ANP with computer image analysis, it was found that the ANP granulus in right atria of electrocution were obviously depleted, compared with that in the control groups. The results showed that depletion of ANP granules in right atria could be used as a reference for the forensic diagnosis of electrocution and might benefit for the clinical therapy to the patients suffering from electric injuries.

Adolescent↗
PubMed1997

Mapping sequence specific DNA-protein interactions: a versatile, quantitative method and its application to transcription factor XF1.

We have developed a method for the quantitative, exhaustive sequence specificity determination of DNA-binding proteins. The QuESSD method overcomes the limitations inherent in other published in vitro selection methods, not only defining the consensus sequence, but also quantifying the effect on DNA-protein affinity of replacing each base in the recognition domain with every other base. The features distinguishing this method from other in vitro selection approaches are: (1) instead of synthesizing one target oligonucleotide population containing a long randomized domain, we synthesize several oligonucleotide populations, each randomized at two positions. (2) Instead of carrying out several cycles of selection and amplification, we carry out a single cycle. (3) We have developed data collection and analysis procedures that eliminate artifacts and allow generation of quantitative results. The QuESSD method yields accurate measures of: (a) the selectivity of the protein for each base at each position within the recognition domain (normalized relative selectivity), (b) the contributions of individual sites within the recognition domain to the binding affinity (selectivity variance), (c) the relative binding affinity of any given sequence (global selectivity). We confirmed results by (1) tabulating directly the frequency of appearance of individual species in the pool of protein-bound oligonucleotides by cloning and sequencing individual oligonucleotides, and (2) competition EMSA analysis of oligonucleotides designed on the basis of QuESSD data. We have used this method to map the sequence specificity of the nuclear protein XF1 and to distinguish the sequence specificities of XF1 and the AH receptor complex, both of which bind to XRE1, a xenobiotic responsive element (XRE) located upstream of the CYP1A1 gene. Using data obtained by the QuESSD method, we designed oligonucleotides specific for XF1 or for the AH receptor, and prepared CAT reporter gene constructs carrying these oligonucleotides, or wild-type XRE1, upstream of a minimal promoter. Transfection studies using these constructs indicated that XF1 can function as a weak activator of basal transcription, and can, under some circumstances, compete with the AH receptor for binding to XRE1.

Animals↗
PubMed1997

The role of endothelial nitric oxide synthase in the pathogenesis of a rat model of hepatopulmonary syndrome.

BACKGROUND & AIMS: The hepatopulmonary syndrome occurs when intrapulmonary vasodilatation causes impaired arterial gas exchange in liver disease. The pathogenesis is poorly understood, although nitric oxide may be involved. Common bile duct ligation in the rat is a model of the hepatopulmonary syndrome, but no studies have evaluated NO in pulmonary vasodilatation in this model. The aim of this study was to determine whether NO contributes to intrapulmonary vasodilatation after bile duct ligation. METHODS: Endothelial and inducible NO synthase (NOS) levels and localization and NO activity in pulmonary artery rings were assessed after bile duct ligation. RESULTS: Pulmonary endothelial NOS levels increased and alveolar vascular staining was enhanced after bile duct ligation. No change in pulmonary inducible NOS levels or localization was detected. Increased endothelial NOS levels correlated with alterations in gas exchange and were accompanied by enhanced NO activity and a blunted response to phenylephrine, reversible by NOS inhibition, in pulmonary artery rings. Portal-vein-ligated animals, which do not develop intrapulmonary vasodilatation, had no changes in pulmonary NOS production or in NO activity in pulmonary artery rings. CONCLUSIONS: NO, derived from pulmonary vascular endothelial NOS, contributes to intrapulmonary vasodilation in animal hepatopulmonary syndrome.

Acetylcholine↗
PubMed1997

Isolation and functional analysis of a cDNA for human Jagged2, a gene encoding a ligand for the Notch1 receptor.

Signaling through Notch receptors has been implicated in the control of cellular differentiation in animals ranging from nematodes to humans. Starting from a human expressed sequence tag-containing sequence resembling that of Serrate, the gene for a ligand of Drosophila melanogaster Notch, we assembled a full-length cDNA, now called human Jagged2, from overlapping cDNA clones. The full-length cDNA encodes a polypeptide having extensive sequence homology to Serrate (40.6% identity and 58.7% similarity) and even greater homology to several putative mammalian Notch ligands that have subsequently been described. When in situ hybridization was performed, expression of the murine Jagged2 homolog was found to be highest in fetal thymus, epidermis, foregut, dorsal root ganglia, and inner ear. In Northern blot analysis of RNA from tissues of 2-week-old mice, the 5.0-kb Jagged2 transcript was most abundant in heart, lung, thymus, skeletal muscle, brain, and testis. Immunohistochemistry revealed coexpression of Jagged2 and Notch1 within thymus and other fetal murine tissues, consistent with interaction of the two proteins in vivo. Coculture of fibroblasts expressing human Jagged2 with murine C2C12 myoblasts inhibited myogenic differentiation, accompanied by increased Notch1 and the appearance of a novel 115-kDa Notch1 fragment. Exposure of C2C12 cells to Jagged2 led to increased amounts of Notch mRNA as well as mRNAs for a second Notch receptor, Notch3, and a second Notch ligand, Jagged1. Constitutively active forms of Notchl in C2C12 cells also induced increased levels of the same set of mRNAs, suggesting positive feedback control of these genes initiated by binding of Jagged2 to Notch1. This feedback control may function in vivo to coordinate differentiation across certain groups of progenitor cells adopting identical cell fates.

Amino Acid Sequence↗
PubMed1997

Common bile duct ligation in the rat: a model of intrapulmonary vasodilatation and hepatopulmonary syndrome.

Hepatopulmonary syndrome (HPS) causes impaired oxygenation due to intrapulmonary vasodilatation in patients with cirrhosis. Chronic common bile duct ligation (CBDL) in the rat results in gas-exchange abnormalities similar to HPS, but intrapulmonary vasodilatation has not been evaluated. We assess intrapulmonary vasodilatation, measured in vivo, after CBDL. Sham, 2- and 5-wk CBDL, and 3-wk partial portal vein ligated (PVL) rats had hepatic and lung injury, portal pressure, and arterial blood gases assessed. The pulmonary microcirculation was evaluated by injecting microspheres (size range 5.5-10 microm) intravenously and measuring the size and number of microspheres bypassing the lungs in arterial blood. CBDL animals developed progressive hepatic injury and portal hypertension accompanied by gas-exchange abnormalities and intrapulmonary vasodilatation. PVL animals, with a similar degree of portal hypertension, did not develop intrapulmonary vasodilatation or abnormal gas exchange. No lung injury was observed. CBDL, but not PVL, causes progressive intrapulmonary vasodilatation, which accompanies worsening arterial gas exchange. These findings validate CBDL as a model to study HPS.

Animals↗
PubMed1997

[Immunohistochemical study on SMDS using anti-actin monoclonal antibody].

For elucidating the relationship between the causes of sudden manhood death syndrome (SMDS) and cardiac sudden death, the cardiac conducting system-(CCS) and myocardium of 23 cases including SMDS group, coronary heart disease group and normal control group were studied using anti-actin monoclonal antibody (HHF35) S-P immunohistochemical method. The results showed that some areas of CCS and myocardium were stained negatively by HHF35 in SMDS group but no infarction area can be found with H.E staining. The negative staining by HHF35 can be also observed in all cases of coronary heart disease group. In control group, the CCS and myocardium stained positively. It indicated that there were pathological changes such as early ischemia or infarction of myocardium in SMDS, which related closely to cardiac sudden death.

Actins↗
PubMed1997

[Colored Doppler ultrasound-guided fine-needle aspiration biopsy of portal vein thrombosis: value in diagnosis and assessment of therapeutic efficacy for portal vein thrombosis].

OBJECTIVE: To investigate the value of colored Doppler ultrasound-guided fine-needle aspiration(FNA) biopsy of portal vien thrombosis(PVT) in diagnosis and assessment of therapeutic efficacy for PVT. METHODS: Cytologic findings from 25 portal vien thrombosis patients who underwent FNA were reviewed before and after hepatic arterial chemo-embolization(HAE) and portal vien chemotherapy. RESULTS: 1. Biopsy specimens sufficient for histologic analysis were obtained in all cases (100%). No complications resulted from this procedure. 2. The blood flow within the portal vien with thrombosis could be detected by colored Doppler systems in 25 cases before the patients accepted the treatment. The proliferation and a trabecular cellular arrangement presented in all the cell blocks. Of the 25 cases, 4 (16.0%) demonstrated necrosis of the tumor thrombi and the disappearance of blood flow within portal vein thrombi three weeks after the treatment. Among the 4, 2 were followed-up clinically and underwent second stage resection. 21 (84.0%) cases had no significant change in portal vein thrombosis pathologically and ultrasonically after the treatment. CONCLUSION: Colored Doppler ultrasound-guided FNA biopsy of portal vein thrombi is a safe, accurate, sampling-reliable biopsy technique.

Adult↗
PubMed1997

[Identification of deer's foetus and its mixed drugs and flase drugs].

In this paper, the traditional Chinese Materia Medicas--the foetuses of sika deer, red deer and the one of sheep and OX are compared and identified on characters and dissecting characteristices. The comparion and identification table about charaeters and commodity shape drawings is attached.

Animals↗
PubMed1996

The diabetic state increases the activity but not the number of peritoneal macrophages in the GK rat promoting the tube formation of cultured endothelial cells in rat aorta.

The influence of the diabetic state on the number and activity of intraperitoneal macrophages was investigated in the GK rat. This rat is a model of non-insulin-dependent diabetes mellitus and was established from the normal Wistar rat. The cell number of a macrophages preparation in diabetic GK rats (10-15 weeks of age) did not differ from that in normal Wistar rats (9-10 weeks of age). The co-cultured macrophages in diabetic GK rats (9-12 weeks of age) significantly increased the tube formation of aortic endothelial cells (EC) compared with that in age-matched Wistar rats. The conditioned medium obtained from a culture of macrophages from GK rats also increased tube formation more than that from a culture of macrophages from Wistar rats. The effect of macrophages in the GK rat was not influenced by interferon-gamma (160 and 460 pM), but macrophages in normal rats were activated by these concentrations of interferon-gamma. In conclusion, the diabetic state increased the activity but not the number of macrophages in the GK rat, to stimulate tube formation of EC. The tube-forming effect of macrophages in the diabetic state may depend on released factors which differ from that of normal macrophages.

Animals↗
PubMed1996

[Color Doppler in evaluating the effects of octreotide on portal hemodynamics].

OBJECTIVE: To study the effects of octreotide on portal pressure and the relationship between the portal pressure and portal hemodynamics measured by color Doppler. METHODS: A high portal resistance model by injecting bletilla hyacinthina was established in 6 dogs. The portal pressure and portal hemodynamics studied by color Doppler were measured respectively by two investigators before and after injecting octreotide into the peripheral vein. RESULTS: Portal hypertension was caused by injecting bletilla hyacinthina into the portal vein. The portal pressure was reduced and portal venous velocity increased after injecting octreotide into the peripheral vein. There was a significant negative correlation between the portal pressure and portal venous velocity. CONCLUSION: Color Doppler is helpful in evaluating the effects of octreotide on the portal pressure.

Animals↗
PubMed1995

Computerized microimage analysis of age-related changes of the human sinoatrial node.

This paper reports the age-related changes in the histological features of the sinoatrial node (SAN). The hearts of 106 persons dying at different ages (2 days-83 years), without clinical or pathological evidence of cardiac disease, were taken and divided into seven age-groups. Serial sections with a thickness of 2 microns, parallel to the long axis of the SAN, were prepared. Sections with the maximal area of the SAN were stained with hematoxylin/eosin (H & E) and Betty's method. The largest area of SAN were calculated by a computerized microimage analysis system. The age-related changes of the human SAN were discussed.

Adolescent↗