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Biomedical subjects

H Ren

Publications and source records attributed to H Ren.

At least 91 records · Page 5Linked to original sources
PubMed1999

Cutaneous and subcutaneous mast cell and eosinophil responses after challenge in mice vaccinated with living infective third-stage hookworm larvae.

OBJECTIVE: To examine the quantitative and qualitative alterations in mast cells and eosinophils distributed in the cutaneous and subcutaneous tissues of hookworm-infected, uninfected and vaccinated mice. METHODS: Outbred male Kunming strain mice, weighing 18-22 g, were vaccinated thrice by subcutaneous inoculation with 500 living third-stage infective larvae (L3) of Ancylostoma caninum (A. caninum) every 2 weeks, and then challenged subcutaneously with 500 L3 one week after the final immunization. Uninfected mice and non-immunized mice but infected with L3 served as controls. The abdominal skin at the site of percutaneous entry was excised from challenged mice at intervals between 6 hours and 7 days after challenge, fixed, and then examined by light microscopy after staining with either toluidine blue or hematoxylin and eosin. RESULTS: The total number of mast cells appearing in cutaneous, and subcutaneous tissues, and underlying abdominal musculature of immunized mice increased significantly compared with non-immunized mice. Mast cells from hookworm-infected mice showed evidence of membrane rupture and degranulation in contrast to the intact appearance of mast cells from uninfected mice. The degree of mast cell degranulation was greater in vaccinated and challenged mice when compared with non-immunized and infected mice. Similarly, eosinophilic infiltration was greatly enhanced after L3 infection. Tissues from vaccinated mice had a greater number of eosinophils than non-immunized mice after infection. CONCLUSIONS: Mast cell alterations appearing earlier than tissue eosinophilic infiltration is major inflammatory response to Ancylostoma caninum (A. caninum) L3 infection in mice. These processes are more obvious in L3-vaccinated mice.

Ancylostoma↗
PubMed1999

[Open lung biopsy in diagnosis of interstitial lung disease].

OBJECTIVE: To evaluate the role of open lung biopsy in diagnosis of interstitial lung disease. METHODS: 24 patients with interstitial lung disease who underwent open lung biopsy from 1993 to June 1998 were reviewed. RESULTS: The documented pathologic diagnosis in 24 patients with interstitial lung disease who underwent open lung biopsies were: 7 IPF (UIP), 1 acute interstitial pneumonia (AIP), 3 BOOP, 2 DPB, 3 sarcoidosis, 2 tuberculosis, 1 histiocytosis-X and 1 lung cancer. Most of these patients did not definitely diagnosed through their clinical evaluation including history, chest X-ray, pulmonary function tests and TBLB. CONCLUSIONS: Open lung biopsy, is a useful method, as it is sensitive and specific in diagnosis of interstitial lung disease. It is helpful in defining the site and extent of interstitial lung disease and diagnosing rare and atypical interstitial lung disease.

Adult↗
PubMed1999

[Management of thoracic esophageal perforation].

OBJECTIVE: To compare surgical management of esophageal perforation on thoracic portion with nonoperative management. METHODS: Seventeen patients were treated for thoracic esophageal perforation at our department between 1962 and 1996. Among them, seven patients underwent nonoperative management. The remaining 10 had operative procedures (primary repair in 5, esophagostomy in 3, and drainage alone in 2 cases). RESULTS: Postoperative leakage occurred in 2 patients; among the two leakages, 1 required cervical esophagostomy, and 1 became a controlled fistula needed pleural drainage and feeding jejunostomy. One patient had anastomotic narrowing after esophagostomy. Of patients with nonoperative management, five survived (with 28% in-hospital mortality rate), Whereas only one patient, who was treated by surgical procedure, died (with 10% inhospital mortality rate). The mean hospital stay in nonoperative and operative group were (28.3 +/- 12.9) days and (57.6 +/- 52.7) days respectively. CONCLUSIONS: The clinical observation suggested that rapid diagnosis of thoracic esophageal perforations is essential and once the diagnosis of esophageal perforation is established, a appropriate management must be selected promptly.

Adult↗
PubMed1998

Adenosine A1 receptor and bipolar affective disorder: systematic screening of the gene and association studies.

In the present study we sought to identify genetic variation in the adenosine A1 receptor (A1AR) gene on chromosome 1q31-32.1, which through alteration of protein function or level of expression might contribute to the genetic predisposition to bipolar affective disorder. We performed a systematic mutation scan of the whole coding sequence as well as 5' and 3' untranslated regions by means of single-strand conformation analysis. The region upstream to the coding sequence we investigated contains two functional promoters. Screening 42 patients with bipolar affective disorder, we detected 11 DNA sequence variants (48T/A, 267 + 275C/T, 805T/G, 1777C/A, 1827C/T, 1904C/T, 2126G/T, 2294insT, 2776C/T, 2777del36, 2819T/G). Determining the frequency of these variants in 42 anonymous blood donors, we observed a non-significant (P < 0.06) trend towards an underrepresentation of the 2126T variant in patients when compared to controls. On the other hand, the 2777del36 and the 2819G variant were not found among the controls. These findings were followed up in a large independent replication sample. However, we were not able to confirm the initial findings in the second sample. Our data suggest that genetically determined variation of the A1AR and its two promoters do not play a major role in the development of bipolar affective disorder.

Base Sequence↗
PubMed1998

Recent developments in DNA electrophoretic separations.

DNA electrophoresis is now a fairly mature technology. Nevertheless, as we approach the 21st century, new ideas are frequently suggested that could lead to a revolution for DNA sequencing and mapping. Here, we review some of the novel concepts that have been studied since ca. 1990. Our review focuses on new separation mechanisms, new sieving matrices and recent conceptual advances.

DNA↗
PubMed1998

Cutaneous and subcutaneous granulomata formation in mice immunized and challenged with third-stage infective hookworm (Ancylostoma caninum) larvae.

To determine the inflammatory and immunological mechanisms associated with live third-stage (L3) hookworm larval vaccines, mice were immunized either subcutaneously or orally with three doses of 500 L3 of Ancylostoma caninum at 2-week intervals, and then challenged percutaneously (via abdominal skin) with 500 L3. Non-immunized mice served as negative controls. Skin was excised from post-challenge mice at intervals between 6 h and 28 days, and then examined by light microscopy. In non-immunized mice the L3 exhibited no structural damage and infiltrating inflammatory cells were absent from the surrounding tissues. There were no changes in the cutaneous architecture. In contrast, skin recovered from the immunized mice was edematous and exhibited marked inflammatory changes with resultant destruction of the challenge L3. At 6 h post-challenge the L3 exhibited cuticular swelling and damage; the surrounding tissue was infiltrated by polymorphonuclear inflammatory cells. By 24 h granulomata in the dermis, subcutaneous tissues and underlying abdominal muscles were first observed surrounding dead L3. The number of granulomata peaked at 72 h, with the majority distributed in the subcutaneous tissues. Plasma cells predominated in the early granulomata, but by 3-7 days post-challenge foreign body giant cells began to appear. In some cases, intact and presumably living L3 were noted in the abdominal muscles 14-28 days post-challenge, which suggested that protection against larval challenge was not absolute. Granuloma formation appears to be a major component of the post-vaccination murine host immune response against challenge larvae. The observation generates several hypotheses to investigate the mechanisms of protection afforded by living helminth vaccines.

Abdominal Muscles↗
PubMed1998

A single-stranded DNA binding site in the human A1 adenosine receptor gene promoter.

Human A1 adenosine receptor gene expression is controlled by two independent promoters. The upstream promoter, promoter A, is subject to tissue specific regulation because not all cells express the mRNA associated with this promoter. One potential regulatory sequence located downstream of the TATA box is an AGG element appearing in a tandem repeat. In a previous study, transient transfection assays showed that mutations made in those AGG elements substantially reduced promoter activity. In the current study, DNase I footprinting indicated nuclear protein binding to this sequence between the TATA box and transcriptional start site. Electrophoretic mobility shift assay confirmed further the presence of an AGG element binding protein (AGBP) in human brain nuclear protein extracts. This binding protein has much higher affinity for single-stranded than for double-stranded DNA, and the binding is sequence specific. A series of assays also showed that AGBP is not related to the nuclear factor SP1 and the binding does not require metal cofactors. Therefore, AGBP is likely to be a specific single-stranded DNA binding protein that is required for the full expression of A1 adenosine receptor gene and particularly abundant in brain tissue.

Base Sequence↗
PubMed1998

Oxidative stress increases A1 adenosine receptor expression by activating nuclear factor kappa B.

The A1 adenosine receptor (A1AR) contributes to the cytoprotective action of adenosine under conditions known to generate reactive oxygen species (ROS). Pharmacological manipulation of A1AR expression has been shown to modulate this cytoprotective role. In this study, we provide evidence that ROS generated could increase the expression of the A1AR and thereby offset the detrimental effects of ROS. Incubation of DDT1MF-2 smooth muscle cells with ROS-generating chemotherapeutic agents, such as cisplatin (2.5 microM) or H2O2 (10 microM), elicited an increase in A1AR expression within 24 hr. The induction by H2O2 was reduced by the ROS scavenger catalase but not superoxide dismutase. Inhibition of nuclear factor kappa B (NF kappa B) by pyrrolidine dithiocarbamate (200 microM), dexamethasone (100 nM), or genistein (1 microM) abrogated the cisplatin-mediated increase in A1AR. Cisplatin promoted rapid translocation of NF kappa B (but not AP-1) to the nucleus, as detected by electrophoretic mobility shift assays and by Western blotting. A putative NF kappa B sequence in the A1AR promoter effectively competed with labeled kappa B probe for binding in nuclear preparations derived from DDT1MF-2 cells. Transient transfection of DDT1MF-2 cells with the A1AR promoter coupled to firefly luciferase reporter gene led to cisplatin-inducible and pyrrolidine dithiocarbamate-sensitive luciferase activity, suggesting the presence of functional NF kappa B binding site(s) in the A1AR promoter sequence. Treatment of cells with (R)-phenylisopropyladenosine (1 microM), an agonist of the A1AR, reduced cisplatin-mediated lipid peroxidation, which was reversed after blockade of the A1AR. These data suggest that ROS can increase the expression of the A1AR by activating NF kappa B regulatory site(s) on this gene and thereby enhance the cytoprotective role of adenosine.

Animals↗
PubMed1998

Protective immunity in mice elicited by living infective third-stage hookworm larvae (Shanghai strain of Ancylostoma caninum).

OBJECTIVE: To elucidate the mechanisms of protective immunity in mice elicited by living hookworm (Ancylostoma caninum third-stage infective larvae (L3). METHODS: The number of migrating infective larvae recovered from the lungs was used as an endpoint for vaccine immunity. The timing of maximal L3 lung entry was determined by counting the number of lung larvae at several time points after infection with 500 or 1000 L3. Mice were immunized either orally or subcutaneously with 500 L3, followed by two boosts of L3 once every two weeks. The immunized mice were challenged orally with 500 L3 one week after the final boost. To evaluate the protective immunity, the number of L3 recovered from the lungs of the immunized mice during the time of maximal larval entry was compared with that of controls. Host immunity was also evaluated by comparing circulating anti-L3 antibodies between immunized and controlled mice, using both enzyme immunoassays and immunoblotting techniques, and by lung histopathology. RESULTS: The peak time of larval entry into the lungs occurred 48 hours after infection. Mice immunized either orally or subcutaneously with L3 exhibited a marked reduction (90.2% and 86.2% respectively) in the number of recovered lung larvae in comparison to controls (P < 0.01). The protection might be associated with circulating anti-L3 antibodies, including antibodies directed against 132-200 kDa L3 antigens, as well as three major antigens ranging from 28 to 51 kDa. Larvae migrating through the lungs of vaccinated mice showed cuticular damages accompanied with host-inflammatory cell invasion. CONCLUSIONS: Immunization with living L3 protects mice against lung invasion after challenged with hookworm infection. Vaccine immunity is associated with circulating antibodies against L3 antigens and lung inflammatory responses. The mouse model is potentially useful for developing a hookworm vaccine.

Ancylostoma↗
PubMed1998

[Renal aquaporin-2 water channel expression in congestive heart failure rat].

OBJECTIVE: To study aquaporin-2 (AQP2) that mediates vasopressin-regulated collecting duct water permeability. METHODS: Male Sprague-Dawley rats (200-250 g) underwent either a left coronary artery ligation, a model of CHF, or a shamoperation (Sham-Op). Five weeks after surgery, mean blood pressure (MBP) and cardiac output (CO) were measured by catheterization in the conscious animal. The rats were sacrificed 24 hours later. Left ventricular myocardial infarction size (LVMI) was estimated and the rats were divided into two groups according to the size of infarction. Total RNA and protein were extracted from whole kidney. AQP2 and GAPDH mRNA were measured by Northern blot and AQP2 protein expression by Western blot. RESULTS: AQP2/GAPDH mRNA densities of Sham-Op, LVMI < 20% rats and LVMI > or = 20% rats were 1.385 +/- 0.023, 1.523 +/- 0.036, and 1.779 +/- 0.072 (P < 0.01). AQP2 protein Western blot densities were 100% +/- 10%, 157% +/- 13% and 202% +/- 25% (P < 0.01). CONCLUSION: Both mRNA and protein of AQP2 gene expression are increased in CHF rat and this upregulation is present in the compensated (LVMI < 20% rats) and decompensated (LVMI > or = 20% rats) stage of CHF. This contributes to water retention associated with CHF.

Animals↗
PubMed1998

A clinicopathological study of Alport syndrome and detection of type IV collagen chains in Alport patients.

OBJECTIVE: To summarize the clinical and pathological findings of Alport syndrome (AS), detect the distribution of type IV collagen within basement membrane of patients with AS and evaluate the diagnostic value of indirect immunofluorescence (iIF) study of type IV collagen in AS. METHODS: Fourteen patients belonging to 12 families were collected from January 1990 to June 1996. The clinical examinations include biochemical examination, audiometry and ocular examination. IIF technique was used to detect the location of chains of type IV collagen in 6 renal and 5 skin specimens from 8 Alport patients. RESULTS: Among fourteen patients, 11 were male and 3 female (mean age 29.4 years). Microscopic hematuria was found in 13 patients, and recurrent gross hematuria in 7. All had proteinuria. Three patients presented nephrotic syndrome. Slowly progressive renal failure occurred in 10 of 11 males (11-39 years) and 1 female (40 years). Sensorineural deafness was observed in 9 patients particularly high frequency sound. Anterior lenticonus were presented in 2. Five families transmitted as X-linked dominant (XD) trait and 3 autosomal dominant, 3 autosomal recessive inheritance. In 7 renal biopsies, the findings by light microscopy mostly revealed focal and segmental sclerosis glomerulonephritis (4/7). The results of IF were negative in 4. Ultrastructural studies showed variable thickening, thinning of glomerular basement membrane (GBM) in 7 specimens with lamellation and basket wearing of GBM in 1. Using the iIF technique, the alpha 3, 4, 5 (IV) chains were observed to be absent within both GBM and EBM of 4 male XD-AS patients. Six patients were treated with hemodialysis, 2/6 with transplantation. CONCLUSION: Alport syndrome (AS) is a heterogeneous hereditary disease characterized by progressive hematuric nephritis with or without sensorineural hearing loss and ocular defects. Ultrastructural alterations of GBM are helpful to the diagnosis of AS. IIF study suggests that type IV collagen in basement membrane of AS was abnormal and iIF study of type IV collagen chains distribution is useful for confirming the diagnosis of AS.

Adolescent↗
PubMed1998

Herbimycin A enhances apoptotic effect of chemotherapeutic drugs on K562 cells.

OBJECTIVES: To explore the anti-apoptotic mechanism and the effective apoptosis-inducing method in chronic myelogenous leukemia (CML) cells. METHODS: K562 cell line was used to observe the effect of combination of herbimycin A (HMA), a tyrosine kinase inhibitor, and chemotherapeutic agents on the induction of apoptosis. RESULTS: HMA or chemotherapeutic agents could inhibit the proliferation but not significantly induce apoptosis of K562 cells. However, HMA significantly enhanced apoptosis when combined with chemotherapeutic agents. Addition of sulfhydryl compound to the cultures to conjugate HMA completely abrogated this enhancing effect on K562 cells. CONCLUSIONS: HMA increases the sensitivity of CML cells to chemotherapeutic agents by inactivating tyrosine kinase activity. It is promising that combination of HMA with conventional chemotherapeutic drugs may be a new strategy in the treatment of CML.

Antibiotics, Antineoplastic↗
PubMed1998

[Polymerase chain reaction associated with dig-labelled DNA hybridization of mip gene to identify new isolated Legionella pneumophila strains].

OBJECTIVE: By testing mip gene, one highly conservative virulence gene of Legionella pneumophila (Lp), as targets of polymerase chain reaction (PCR) and Digoxin-labelled probe hybridization to establish a rapid, specific and sensitive gene analysis method that can identify new isolated suspected bacteria strains as Lp. METHOD: Abstracting all the CDC reference Lp strains' and none-Lp Legionella strains' DNA, as well as the domestic isolated Lp strains' and some non-Legionella control bacteria's DNA as templates, then were processed. All the positive PCR products(if no PCR amplicons were available, the original whole DNA should be detected) were hybridized with Digoxingen-labelled mip gene probe in dot-blot procedure. RESULT: All the tested Lp strains had positive PCR and hybridization results, at the same time, all none-Legionella bacteria and none-Lp Legionella strains got negative results. 6 of 26 isolates were identified as Lp strains by this method. CONCLUSION: Such a Lp strain identification procedure shows high specificity and sensitivity (nearly 100%, in this study), and mean-while can be completed in a relative short time. Surely, this method can be largely available and has a potential value in diagnosis of clinical Legionellosis cases and pursuing the pathogen during Legionnaires' disease outbreaks.

Bacterial Proteins↗
PubMed1998

[Diagnosis and treatment of thoracic outlet syndrome].

OBJECTIVE: Thoracic outlet syndrome (TOS) is clinically common, but liable to be misdiagnosed. We would like to emphasize the recognition of TOS, and through thorough examination for a complete relief from indicated operation. METHODS: 13 cases receiving surgical operations in PUMC hospital from 1982 to 1996 are reported and discussed the cause of misdiagnosis, investigate the various kinds of abnormalities and compare the result of operation. RESULTS: 92% of the patients had experence of being misdiagnosed for other diseases, the history may be as long as 10 years. In the operations we found 8 kinds of anatomic abnormalities that cause the symptoms and complete relief is satisfactory. CONCLUSIONS: We have to emphasize the recognition of TOS. The thorough physical examination is important to diagnosis. Patients with typical and apparent symptoms need an operation to relieve the thoracic outlet through the transaxillary approach.

Adolescent↗
PubMed1998

[Subxiphoid pericardial window drainage in the management of large pericardial effusions].

OBJECTIVE: To choose a safe, effective, minimum invasive procedure for treatment of patients with a large pericardial effusion and cardiac tamponade. METHODS: Retrospective analysis of 30 cases with large pericardial effusion or cardiac tamponade diagnosed by echocardiography during four years (1993-1997). The subxiphoid pericardial window drainage and pericardial tissue biopsy was performed. RESULTS: The symptoms were improved immediately following the drainage. The drainage volume during operation was 200-2,000 ml, and postoperation was 0-2,000 ml. The drainage tube was kept in position for average of 5.6 days. With the echocardiography follow up, the pericardial effusion disappeared or remained only minimum fluid in 96.7% of the patients. The complications happened in 6 cases. The 30-days mortality was 6.7%. CONCLUSIONS: The subxiphoid pericardial window drainage procedure is the first choice for a safe, effective, minimal invasive and easy to do procedure for the patients with a large pericardial effusions or cardiac tamponade.

Adolescent↗
PubMed1998

[Simultaneously monitoring end tidal CO2 and other parameters versus anesthesia management].

OBJECTIVE: To investigate the significance of end tidal CO2(ETCO2) combined with other techniques in anesthesia management. METHODS: Twenty two patients undergoing general anesthesia were monitored with electromyocardiogram (ECG), invasive arterial blood pressure (IABP), plethysmogram and capnography simultaneously. Ten patients undergoing epidural anesthesia and cervical plexus block were monitored with ETCO2. RESULTS: During general anesthesia the depth of general anesthesia, status of ventilation and the degree of muscle relaxation could be grossly evaluated by simultaneously monitoring ETCO2, capnography, plethysmogram, ECG and IABP. ETCO2 could also provide an objective standard for the assessment of respiratory function during spontaneous ventilation. CONCLUSIONS: ETCO2 combined with other monitoring techniques can increase the safety of anesthesia and the accuracy of anesthesia management.

Anesthesia, Epidural↗
PubMed1997

Characterization of maize (Zea mays) pollen profilin function in vitro and in live cells.

Profilin is a small, 12-15 kDa, actin-binding protein that interacts with at least three different ligands. The 1:1 interaction of profilin with globular actin (G-actin) was originally thought to provide a mechanism for sequestering actin monomers in the cytoplasm. It has recently become clear that the role of profilin in the cell is more complex, perhaps due to interactions with polyphosphoinositides and proline-rich proteins, or due to the ability to lower the critical concentration for actin assembly at the fast-growing barbed end of actin filaments. Because actin-binding proteins have been shown to behave differently with heterologous sources of actin, we characterized the interaction between maize pollen profilins and plant G-actin. The equilibrium dissociation constants measured by tryptophan fluorescence quenching were similar to those of other CaATP-G-actin-profilin complexes (Kd=1.0-1.5 microM). The ability of maize profilin isoforms to bind poly-l-proline was analysed, and the Kd values for recombinant pollen and human profilins were similar when determined by two independent methods. However, the affinity of native maize pollen profilin for poly-l-proline was substantially lower than that of any of the recombinant proteins by one of these assays. The possibility of post-translational modification of profilin in the mature pollen grain is discussed. Finally, we quantified the effects of microinjection of each profilin isoform on the cytoarchitecture of Tradescantia stamen hair cells and show that the resultant disruption can be used to compare actin-binding proteins in living cells. The results are discussed in relation to a recent model of the interphase actin array in these plant cells.

Actins↗