Biomedical subjects

Q Dong

Publications and source records attributed to Q Dong.

At least 73 records · Page 4Linked to original sources

PubMed1999

[A clinical research for eosinophilic meningoencephalitis caused by angiostrongyliasis].

OBJECTIVE: To improve the awareness of angiostrongyliasis. METHODS: The clinical and laboratory data as well as the epidemiological informations of 18 patients with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis were analyzed. RESULTS: All the patients had a history of eating raw fresh water snail (Ampularium canaliculatus) before the onset of the disease. Incubation period ranged from 1 to 25 days. The major symptoms of the patients were severe headache and pain in the trunk and limbs. Peripheral blood eosinophilia was noted together with increased eosinophilic count in cerebrospinal fluid. With ELISA sera from patients were specifically IgG-antibody positive against Angiostrongylus cantonensis antigen, but were negative against other parasitic antigens such as Paragonimus westermani, Cysticercus, Cellulosae hominis, Echinococcus granulosus and Trichinella spiralis. Abnormal spot signal was found in 2 cases with brain magnetic resonance imaging. Electroencephalogram showed slow alpha rhythm. All the patients were effectively treated with good combined administration of albendazole and dexamethasone. CONCLUSION: Angiostrongyliasis is one of the common causes leading to eosinophilic meningoencephalitis. To our knowledge, Wenzhou is the first small outbreak site discovered of angiostrongyliasis in mainland China.

Adult↗

PubMed1999

[Effects of 7 d head down tilt on cardiopulmonary circulation during orthostasis].

Objective. To accumulate data for further studies on the mechanisms of the decrease of cardiovascular function after weightlessness. Method. Cardiopulmonary circulatory function under supine position and head up tilting (HUT) for 20 min before and after exposure to 7 d 6 degrees head down tilt (HDT) in 6 healthy adults who aged 19-21 were measured with a XXH-2000 lesser (pulmonary) circulation and cardiac function instrument. Result. The 7 d HDT resulted in orthostatic intolerance of the subjects; the reduction of RVET (j-z) and the elevation of RPEP [RVET(Q-j)/(j - z)] indicated a decrease of the right heart function. An obvious decrease of the right heart reserves was also observed under HUT after HDT. Conclusion. hc and hc/hz were demonstrated to be useful parameters to evaluate orthostatic tolerance or to forecast orthostatic syncope. The lesser (pulmonary) circulation and cardiac function testing methods are valuable in evaluating the cardiopulmonary circulatory function during HUT.

Adult↗

PubMed1999

[Surface-enhanced Raman spectroscopy of riboflavin in silver colloids using 1 064 nm excitation].

Surface-enhanced Raman spectra (SERS) of riboflavin in silver colloids, using near-infrared (NIR) laser operating at 1 064 nm wavelength, were obtained. The enhancement factor was further increased by improving the preparation of silver colloid and with the addition of a small amount of NaOH. The detection limit was lower than 3.2 x 10(-10) mol x L(-1). It is concluded that the larger and aggregated silver particles were more efficient for the electromagnetic enhancement of NIR-SERS. Flavin ring was absorbed on the colloidal silver methal surface, standing on oxygens of C(20)=O) and C(4)=O.

English Abstract↗

PubMed1998

Common ancestral mutation in the MEN1 gene is likely responsible for the prolactinoma variant of MEN1 (MEN1Burin) in four kindreds from Newfoundland.

Familial multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder with affected individuals developing parathyroid, gastrointestinal (GI) endocrine, and anterior pituitary tumors. Four large kindreds from the Burin peninsula/Fortune Bay area of Newfoundland with prominent features of prolactinomas, carcinoids, and parathyroid tumors (referred to as MEN1Burin) have been described, and they show linkage to 11q13, the same locus as that of MEN1. Haplotype analysis with 16 polymorphic markers now reveals that representative affected individuals from all four families share a common haplotype over a 2.5 Mb region. A nonsense mutation in the MEN1 gene has been found to be responsible for the disease in the affected members in all four of the MEN1Burin families, providing convincing evidence of a common founder.

Alleles↗

PubMed1998

A cross-cultural study of family and peer correlates of adolescent misconduct.

Participants were 4 groups of early adolescents from middle-class backgrounds (European and Chinese Americans in southern California and Chinese in Taipei, Taiwan, and Beijing, China). The 591 adolescents (M age = 13.8 years) completed questionnaires about their involvement in misconduct and about family and peer characteristics. Mothers of a subsample of adolescents (n = 405) also completed a questionnaire about their relationships with their adolescents. The 4 groups of adolescents reported significantly different mean levels of family and peer correlates but showed strikingly similar levels and patterns of self-reported misconduct. Structural equation models revealed that 2 latent variables (family relationships and peer sanctions) accounted for more variance in misconduct among European and Chinese American adolescents (51%-62%) than among the 2 Chinese groups (15%-24%), mainly because of a greater contribution of peer factors in the former groups.

Adolescent↗

PubMed1998

Gadolinium-enhanced magnetic resonance venography of the portal venous system prior to transjugular intrahepatic portosystemic shunts and liver transplantation. Original investigation.

RATIONALE AND OBJECTIVES: The accuracy of gadolinium-enhanced magnetic resonance venography (GdMRV) in identifying visceral venous abnormalities was assessed in patients before they underwent transjugular intrahepatic portosystemic shunt (TIPS) or orthotopic liver transplantation (OLT). METHODS: Twenty-seven patients with portal hypertension underwent GdMRV and transcatheter venography prior to OLT or TIPS. The gadolinium dose was 0.5 mL/kg (0.25 mmol/kg), administered by rapid hand injection. Coronal 3D spoiled gradient-echo GdMRV was performed in a single breath-hold. Four blinded reviewers retrospectively evaluated coronal maximum intensity projection (MIP) images, while two reviewers evaluated the MIPs and multiplanar reconstructions. Abnormalities that could affect transjugular intrahepatic portosystemic shunt or transplantation were noted and compared with the results of corresponding catheter venograms read by a separate blinded reviewer. RESULTS: Abnormalities were identified by GdMRV with a sensitivity and specificity of 83% and 97% for the right hepatic vein, 86% and 100% for the main portal vein (MPV), 42% and 99% for the right portal vein, 54% and 94% for the left portal vein, 61% and 96% for the superior mesenteric vein, and 74% and 91% for the splenic vein. Varices and shunts were correctly identified with a sensitivity of 96%. Multiplanar reconstruction increased MPV sensitivity to 100%. CONCLUSION: Vascular abnormalities that affect TIPS and OLT can be identified by GdMRV. Multiplanar reconstruction increased the accuracy to 100% for the MPV.

Catheterization, Central Venous↗

PubMed1998

Renal anatomic changes on magnetic resonance imaging and gadolinium-enhanced magnetic resonance angiography after renal revascularization. Original investigation.

RATIONALE AND OBJECTIVES: The anatomic and hemodynamic renal changes after renal arterial revascularization (RAR) were investigated. METHODS: Thirty-seven kidneys and 40 renal arteries were evaluated in 20 patients by using magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) to assess pre- and post-RAR renal length and mass, parenchymal thickness, renal enhancement, renal artery caliber, poststenotic dilation, and signal dephasing on 3D phase contrast (PC). The kidneys and renal arteries were segregated into three groups. Group 1 included 16 patients who benefited from RAR (defined as clinical improvement based on decreased serum creatinine or fewer number of antihypertensive medications) in whom 26 renal arteries in 25 kidneys were studied. Intervention included renal artery endarterectomy (n = 20); aortorenal bypass (n = 3); renal artery reimplantation (n = 3); and percutaneous transluminal angioplasty (PTA; n = 1). A total of 27 interventions was performed, as PTA failed for one patient who subsequently underwent aortorenal bypass before reimaging. Group 2 included four patients who did not clinically benefit. A total of eight revascularized arteries were studied in seven kidneys. In group 3, six renal arteries in five kidneys from groups 1 and 2 without RAS/RAR were analyzed as an internal control. RESULTS: Technical success (defined as increased vessel caliber after intervention) was achieved in 33 of the 34 revascularized arteries. A statistically significant increase in renal length occurred regardless of clinical outcome (pre-RAR, 9.5 cm; post-RAR, 10.5 cm; P < 0.0001). Parenchymal thickness and renal mass, however, improved only in patients who benefited clinically from RAR. Parenchymal enhancement was unchanged in any of the groups studied. No significant morphologic changes were detected in the control group. CONCLUSIONS: Magnetic resonance imaging and Gd-MRA detect anatomic and hemodynamic changes that occur with renal revascularization.

Adult↗

PubMed1998

Magnetic resonance angiography with gadomer-17. An animal study original investigation.

RATIONALE AND OBJECTIVES: Our purpose was to investigate a "blood pool" contrast agent for abdominal and thoracic MR angiography by comparison with standard ionic and nonionic gadolinium-based contrast agents, which redistribute into the extracellular fluid compartment. METHODS: Abdominal and thoracic MR angiography was performed in three adult dogs using a three-dimensional spoiled gradient echo pulse sequence before and after intravenous administration of one of three gadolinium-based contrast agents (gadopentetate dimeglumine, gadobutrol, and gadomer-17). Each compound was tested at five different doses in all three dogs. Quantitative analysis of signal-to-noise ratio (SNR) was performed in the aorta, inferior vena cava (IVC), liver, spleen, kidney (medulla and cortex), fat, and muscle. RESULTS: Gadomer-17 improved visualization of vascular anatomy at doses of 0.025, 0.05, 0.1, and 0.2 mmol/kg with three-fold greater aorta SNR during the arterial phase and more than four-fold greater aorta and IVC SNR during the equilibrium phase, in comparison with gadopentetate dimeglumine and gadobutrol at equal doses. CONCLUSIONS: Gadomer-17 is a promising contrast agent for both arterial phase and equilibrium phase MR angiography.

Adipose Tissue↗

PubMed1998

Vascular complications of liver transplantation: evaluation with gadolinium-enhanced MR angiography.

PURPOSE: To evaluate use of gadolinium-enhanced magnetic resonance (MR) angiography in detection of vascular complications of liver transplantation. MATERIALS AND METHODS: Thirteen liver transplant recipients suspected to have vascular complications were evaluated with gadolinium-enhanced MR angiography by using a three-dimensional spoiled gradient-echo breath-hold technique during the arterial and venous phases of a high-dose (42 mL) bolus injection of gadolinium contrast material. Conventional angiography (n = 11) and surgery (n = 3) were used as the standard of reference. The transplant hepatic artery, celiac trunk, superior mesenteric artery, portal vein, superior mesenteric vein, splenic vein, hepatic veins, and inferior vena cava (IVC) were evaluated for thrombosis or stenosis by two radiologists. RESULTS: Ten vascular complications were identified with conventional angiography or surgery: transplant hepatic artery thrombosis (n = 3) or stenosis (n = 3), portal vein stenosis (n = 1) or occlusion (n = 2), and suprahepatic IVC stenosis (n = 1). All 10 complications were correctly diagnosed with MR angiography. There was agreement between results of MR angiography and conventional angiography or surgery in 58 of 62 vessels evaluated (94%). There was minor disagreement in four vessels (6%). CONCLUSION: Three-dimensional gadolinium-enhanced MR angiography may have the potential to enable accurate diagnosis of vascular complications of liver transplantation.

Adolescent↗

PubMed1998

Degradation of surfactant protein D by alveolar macrophages.

Surfactant protein (SP) D is a pulmonary surfactant-associated protein that may function in lung host defense. SP-D is produced by alveolar type II cells and nonciliated bronchiolar epithelial (Clara) cells of the airway and is secreted into the air space. Here we investigated whether alveolar macrophages degraded SP-D in vitro. We also examined the effects of SP-A and lipids on SP-D metabolism. The results showed that alveolar macrophages bound and degraded SP-D in a time- and temperature-dependent fashion. After 100 min of incubation, the formation of trichloroacetic acid-soluble degradation products increased 4-fold in the medium and 30-fold in the cells. The degradation of SP-D was via a cell-associated process because SP-D was not degraded when incubated in medium previously conditioned by alveolar macrophages. Gel autoradiography of cell lysate samples after incubation with 125I-labeled SP-D demonstrated an increase in degradation products, further confirming the degradation of SP-D by alveolar macrophages. In addition, the degradation of SP-D was not affected by coincubation with SP-A or surfactant-like liposomes containing either phosphatidylglycerol or phosphatidylinositol. In conclusion, alveolar macrophages rapidly degrade SP-D and may play an important role in SP-D turnover and clearance.

Animals↗

PubMed1998

Prognostic factors for survival of patients treated systemically for disseminated melanoma.

PURPOSE: The current American Joint Commission on Cancer (AJCC) staging system distinguishes between soft tissue and visceral metastases in advanced (stage IV) melanoma. We sought to verify these staging criteria and to identify prognostic variables that could be used to evaluate the impact of systemic therapy on long-term survival during the prior decade. PATIENTS AND METHODS: We conducted a retrospective study of patients with advanced cutaneous melanoma enrolled in clinical trials between 1979 and 1989 at The University of Texas M.D. Anderson Cancer Center. Pretreatment age, sex, number of organs with metastases, serum levels of lactate dehydrogenase (LDH) and albumin, and period of enrollment were analyzed using a Cox proportional hazards model of survival. RESULTS: In univariate and multivariate analyses that involved 318 stage IV patients, normal serum levels of LDH and albumin, soft tissue and/or single visceral organ metastases (especially lung), female sex, and enrollment late in the decade were independent positive predictors for survival. In multivariate analyses, the current AJCC criteria did not significantly predict outcome. Systemic treatment response did not bias these results, and only 4% of patients had a complete response. Patients who lived more than 2 years (11%) had a mix of favorable prognostic characteristics and a high frequency of systemic or surgically induced complete response. CONCLUSION: This study supports the use of stratification parameters that reflect the favorable prognostic impact of soft tissue or single visceral organ metastases and normal serum levels of LDH and albumin at time of enrollment in advanced melanoma trials. Improved survival over the prior decade probably reflects advances in diagnostic and palliative interventions.

Adult↗

PubMed1998

[A survey of prostate symptoms in old male population].

To know well the prostate symptoms in old men, the prostate symptom scores of 412 male residents over 60 years of age in Chengdu area (116 in city and 296 in countryside) were investigated by using I-PSS. The results showed that there was a significant difference between the city and countryside in terms of symptoms score(P < 0.05) and quality of life scores (P < 0.05). No significant difference was noted among the three age groups (P > 0.05). However, the mean score and the percentage of high score section in the elder group were higher than those in the younger group. The prevalence of benign prostate hypertrophy (BPH) and the demands on quality of life in city were different from those in countryside, and the prevalence rate of BPH increased with age.

Aged↗

PubMed1998

[A comparison study on the sensitivity of lung tumor short-term induction test in three strains of mice].

To compare the sensitivities of lung tumor short-term induction in different strains of mice, the carcinogenicity risk was evaluated with the incidence rate and the average number of tumors. Three different strains of mice (KM, BALB/c and A/J) were injected with a single different dose of urethane i.p. The results demonstrated that the lowest dose for increasing tumor risk was 100 mg/kg in KM, 200 mg/kg in BALB/c, and lower than 25 mg/kg in A/J strain. So, the sensitivity of A/J strain is the highest and that of BALB/c is the lowest.

Animals↗

PubMed1998

[Effect of 7 d head down bed rest on cardiopulmonary circulation in human].

Changes of cardiopulmonary circulation in 6 healthy young men during 7 d head down bed rest (-6 degrees HDT) were observed with the XXH-2000 lesser circulation and cardiac function instrument. Decrease of Q-j and Q-j/j-z, increase of hz, hc, and hc/hz were found during the initial 24 h. After 24 h, j-z decreased and Q-j/j-z increased. The results showed that increased pulmonary arterial pressure, increased preload of left and right heart, increased right myocardial contractility and congestion of the lungs appeared during 24 h bed rest, after which right myocardial contractility decreased. It suggests that the lesser circulation and cardiac function testing is a sensitive method for evaluating the cardiopulmonary circulation function during HDT.

Adult↗

PubMed1998

[Changes in cerebral circulation function during head down bed rest for 7 days].

To further understand the effects and regulation of brain circulation before, during and after short-term -6 degrees head down bed rest (HDT), 6 healthy young men aged 19-21 years, were subjected to HDT for 7 d. Cerebral blood flow velocity in the middle cerebral arteries of both sides was measured with a TC2000TCD instrument in 6 young adults before, during, and after 7d HDT. The results showed that cerebral blood flow velocity in the middle cerebral arteries increased throughout HDT, the increase was obvious in 24 h. They reached the highest value at the 4th hour and the lowest value on the 5 th day, and then, there were a tendency to rise on the 6th day and 7th day. The changes were about the same on both sides.

Adult↗

PubMed1998

A potential approach to antifertility vaccine by expression of sperm membrane peptide in Salmonella.

A synthetic oligonucleotide, HSD-2a, encoding a peptide segment of the extracellular domain of a human sperm membrane protein, YWK-II, was inserted by blunt-end ligation at the EcoRV site in the hypervariable, antigenically determinant region IV of Salmonella flagellin gene fliC (d). The recombinant plasmid (pLS408-H1) was transferred into the nonpathogenic aroA live vaccine Salmonella dublin strain SL5928, which is flagellin-negative. Location of the HSD-2a protein on the surface of the flagella was demonstrated by ELISA and by immunogold-labeling electron microscopy using mouse anti-YWK-II antiserum. A 60 kD protein, corresponding to the chimeric flagellin, was isolated from the recombinant S. dublin and found to contain the expressed HSD-2a peptide determined by Western blot analysis using anti-YWK-II antiserum. The Salmonella strain carrying the recombinant plasmid-pLS408-H1 may thus be a potential source of antifertility vaccine.

Amyloid beta-Protein Precursor↗

PubMed1998

Cloning, gene structure and genomic localization of an orphan transporter from mouse kidney with six alternatively-spliced isoforms.

Two genes were identified and characterized that express cDNAs related to previously identified neurotransmitter and/or osmolyte transporters, but which are expressed specifically in the kidney. RNA transcribed from one of these two genes (XT2) was found to undergo an extensive degree of alternative splicing to generate six distinct isoforms. The intron-exon structure of the XT2 gene and the sites of alternative splicing were identified. Expression of the second gene (XT3) was found to be conserved in human kidney, and partial sequence was obtained from a human cDNA library. The expressions of both XT2 and XT3 RNAs were determined in mouse and human tissues, respectively, and the locations of the two genes within the mouse genome were identified. Screening experiments to identify the substrate(s) of these proteins failed to identify specific uptake with any of the tested compounds; however, immunofluorescent microscopy demonstrated that epitope-tagged variants of the protein products of the XT2 and XT3 cDNAs were present on the plasma membrane of transfected cells.

Alternative Splicing↗

PubMed1997

Methylator resistance mediated by mismatch repair deficiency in a glioblastoma multiforme xenograft.

A methylator-resistant human glioblastoma multiforme xenograft, D-245 MG (PR), in athymic nude mice was established by serially treating the parent xenograft D-245 MG with procarbazine. D-245 MG xenografts were sensitive to procarbazine, temozolomide, N-methyl-N-nitrosourea, 1,3-bis(2-chloroethyl)-1-nitrosourea, 9-aminocamptothecin, topotecan, CPT-11, cyclophosphamide, and busulfan. D-245 MG (PR) xenografts were resistant to procarbazine, temozolomide, N-methyl-N-nitrosourea, and busulfan, but they were sensitive to the other agents. Both D-245 MG and D-245 MG (PR) xenografts displayed no O6-alkylguanine-DNA alkyltransferase activity, and their levels of glutathione and glutathione-S-transferase were similar. D-245 MG xenografts expressed the human mismatch repair proteins hMSH2 and hMLH1, whereas D-245 MG (PR) expressed hMLH1 but not hMSH2.

Animals↗