Biomedical subjects

H H Wang

Publications and source records attributed to H H Wang.

At least 19 recordsLinked to original sources

PubMed2006

Gene therapeutic treatment of pancreatic cancer based on injection of pcDNA3.1/CCK plasmid with xenogeneic homologous cholecystokinin.

AIM: To study the therapeutic effect of recombinant plasmid pcDNA3.1/CCK containing porcine gene of cholecystokinin (CCK). METHODS: The confirmed fragments of porcine CCK cDNA were cloned into the pcDNA3.1 vector. Recombinant plasmid pcDNA3.1/CCK was injected into the muscles of Syrian golden hamsters. Before gene transfer, orthotopic tumor model and liver metastasis model of hamster pancreatic cancer have been established by injection of 1 x 10(6) PGHAM-1 cells into the pancreas and spleen of golden hamsters. Then the CCK expression in vivo and the tumor inhibiting effect were analyzed. RESULTS: Our data revealed that recombinant plasmid pcDNA3.1/CCK had long-term expression in hamsters and induced generation of specific antibody. Antibody level correlated with the number of inoculations. Compared to the control, significant reduction in tumor volume, decrease in number of liver metastasis and a remarkable enhancement of survival rate were detected. CONCLUSION: Intramuscular injection of recombinant plasmid pcDNA3.1/CCK has significant antitumor and antimetastatic effect in vivo.

Animals↗

PubMed2005

Antibody response to four secretory proteins from Mycobacterium tuberculosis and their complex antigen in TB patients.

OBJECTIVE: To evaluate antibody responses to a panel of four protein antigens secreted from Mycobacterium tuberculosis, CFP-21, ESAT-6, MPT-63 and MPT-64, and their complex antigen. DESIGN: Seventy-eight samples of serum and cerebral spinal fluid were tested by ELISA. RESULTS: Serum IgM antibody positive rates of protein antigens CFP-21, ESAT-6, MPT-63 and MPT-64 and their multi-antigen complex were respectively 34.6%, 60.3%, 52.6%, 78.2% and 96.2%; IgG antibody positive rates were respectively 46.2%, 64.1%, 93.6%, 57.7% and 84.6%. The specificity of the antibodies to the four proteins secreted from M. tuberculosis and its mixture antigen was 100%; sensitivity to the multi-antigen complex was higher than for the four single antigens. Among the IgM positive rates, the differences between the multi-antigen complex and CFP-21, ESAT-6, MPT-63 and MPT-64 were significant (P < 0.01); among the IgG positive rates, the differences between the multi-antigen complex and CFP-21, ESAT-6 and MPT-64 were significant (P < 0.01). Although the IgG positive rate for MPT-63 was higher than for the multi-antigen complex, the difference was not significantly different (P > 0.05). CONCLUSION: These findings indicate that the multi-antigen complex composed of CFP-21, ESAT-6, MPT-63 and MPT-64 may be useful in the diagnosis of TB.

Adult↗

PubMed2004

A real-time polymerase chain reaction-based method for rapid and specific detection of spoilage Alicyclobacillus spp. in apple juice.

AIMS: To develop a real-time PCR-based rapid detection method for spoilage Alicyclobacillus spp. in juice products. METHODS AND RESULTS: The squalene-hopene cyclase-encoding gene was targeted for primer-and-probe development. Gene fragments from representative strains were cloned, and PCR primers and probe were designed by DNA sequence comparison. Selected bacteria were examined for cross-reactivity by the new method. Cells were serially diluted in apple juice and saline, and examined by the new method to establish detection sensitivity. Using the newly developed Taqman real-time PCR-based method, strains of Alicyclobacillus acidocaldarius and A. acidoterrestris were detected without cross reactivity with other common food-borne micro-organisms. Detection of <10 cells per PCR reaction from juice samples was accomplished within 3-5 h. CONCLUSION: This is the first reported real-time PCR-based detection method for Alicyclobacillus spp. and its application in juice products is demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: As a favourable alternative for the laborious and time-consuming culture- or biochemical characterization-based techniques, the system has great potential for industrial applications from raw material screening to final product quality control.

Bacillus↗

PubMed2003

In vitro activities of small peptides from snake venom against clinical isolates of drug-resistant Mycobacterium tuberculosis.

The recent re-emergence of tuberculosis, especially the multidrug-resistant cases, has highlighted the importance of screening effective novel drugs against Mycobacterium tuberculosis. In this study, the in vitro activities of small peptides isolated from snake venom were investigated against multidrug-resistant M. tuberculosis. Minimum inhibitory concentrations (MICs) were determined by the Bactec TB-460 radiometric method. A small peptide with the amino acid sequence ECYRKSDIVTCEPWQKFCYREVTFFPNHPVYLSGCASECTETNSKWCCTTDKCNRARGG (designated as vgf-1) from Naja atra (isolated from Yunnan province of China) venom had in vitro activity against clinically isolated multidrug-resistant strains of M. tuberculosis. The MIC was 8.5 mg/l. The antimycobacterial domain of this 60aa peptide is under investigation.

Amino Acid Sequence↗

PubMed2002

Regulation of B16F1 melanoma cell metastasis by inducible functions of the hepatic microvasculature.

We have previously shown that circulating intravascular cells generally arrest by mechanical restriction in the hepatic sinusoids, causing rapid release of nitric oxide (NO) which is cytotoxic to these cells and inhibits their growth into metastatic tumours. Here, we present evidence that these NO-dependent cytotoxic mechanisms are susceptible to upregulation by lipopolysaccharide (LPS). Five x 10(5) fluorescently labelled melanoma cells were injected into the mesenteric vein of C57BL/6 mice to effect their localisation in the hepatic microvasculature. Test mice were then given 1 mg/kg LPS intraperitoneally (i.p.) to activate the microvascular cells. By electron paramagnetic resonance (EPR) spectroscopy, the expression of NO in the liver was significantly increased by 8 h in the LPS-treated mice. The non-selective NO synthase inhibitor L-NAME inhibited the induction of NO by LPS, while its inactive enantiomer D-NAME had no significant effect. Using immunohistochemistry (IHC), iNOS-positive microvascular cells were detected in the terminal portal venule (TPV) region of the liver 8 h after LPS stimulation. LPS treatment also increased the retention of melanoma cells in the liver between 8 and 24 h, especially in the TPV region. Eight hours after cell injection, local expression of VCAM-1 and ICAM-1 was detected by double-label immunohistochemistry at the sites of tumour cell arrest. Expression of these adhesion molecules was enhanced in mice treated with LPS. Using flow cytometry, 98% of the B16F1 melanoma cells expressed VLA-4, the counter receptor of VCAM-1, and approximately 1.5% expressed LFA-1, the counter receptor of ICAM-1. LPS did not significantly alter the expression of either counter receptor on melanoma cells in vitro or in vivo. By DNA end-labelling, the rates of melanoma cell apoptosis were significantly increased from 8 to 24 h in the TPV region (but not in the sinusoids) of LPS-treated mice. Fourteen days after tumour cell injection, the LPS-treated mice had a significantly smaller hepatic metastatic tumour burden than the control mice. These data suggest that LPS can inhibit the metastasis of melanoma cells in the liver by inducing the expression of NO and adhesion molecules by the hepatic endothelium. The induction of iNOS and the inducible cytotoxic effect of LPS appear to be primarily located within the TPV region of the liver acinus.

Animals↗

PubMed2002

Assignment of the Raman spectra of some deuterated-BEDT-TTF superconductors.

We present the room-temperature Raman spectra of both the protonated and deuterated forms of kappa-(BEDT-TTF)2Cu[N(CN)2]Br, kappa-(BEDT-TTF)2Cu(NCS)2 and beta-(BEDT-TTF)2I3. Along with data for the neutral BEDT-TTF molecule these spectra are used to assign the many features in the spectra of the deuterated compounds.

Deuterium↗

PubMed2001

Significance of a diagnosis of atypical squamous cells of undetermined significance for Papanicolaou smears in perimenopausal and postmenopausal women.

BACKGROUND: The current study was conducted to determine the significance of a diagnosis of atypical squamous cells of undetermined significance (ASCUS) in perimenopausal and postmenopausal women. METHODS: The reports for all Papanicolaou (Pap) smears viewed in the study institution's cytology laboratory over a 6-month period were reviewed. Women were divided into premenopausal (age < or = 45 years), perimenopausal (ages 46-54 years), and postmenopausal (age > or = 55 years) categories. Slide review and 2-year follow-up were obtained for selected cases diagnosed as ASCUS. ASCUS cases among the perimenopausal women were compared with an age-matched control group. RESULTS: The total number of abnormal Pap smears in the premenopausal, perimenopausal, and postmenopausal categories were 770 (6.8%), 104 (4.3%), and 67 (2.9%), with 482, 83, and 41 diagnoses of ASCUS, respectively. The ratio of ASCUS to squamous intraepithelial lesions (SIL) was 2.2 overall and 1.9, 7.5, and 4.1, respectively, for each group (P < 0.001). The positive predictive value for a diagnosis of SIL on subsequent Pap smears or biopsies was 22%, 12.2%, and 29.7%, respectively. Slide review showed that the premenopausal ASCUS cases appeared to have a higher percentage of nuclear-cytoplasmic ratio increase and nuclear membrane irregularities compared with the other categories (P = 0.03 and P = 0.02, respectively) and the perimenopausal group was found to have more ASCUS in metaplastic cells (P = 0.03). In perimenopausal women, slides diagnosed as ASCUS demonstrated more air-drying artifact than the control group (P = 0.004) but had less obvious atrophy (P = 0.01). CONCLUSIONS: Despite a decreased abnormality rate with increasing age, the results of the current study show that the perimenopausal and postmenopausal groups appear to have elevated ASCUS-to-SIL ratios. ASCUS appears to have a particularly low positive predictive value for SIL in perimenopausal women, and therefore most likely is overcalled in this age group. This may be attributable in part to air-drying artifact and subtle atrophic changes.

Age Factors↗

PubMed2001

Inhibition of Escherichia coli by dimethyl fumarate.

The antibacterial activity of dimethyl fumarate (DMF) and six other compounds against Escherichia coli (E. coli, K12) was investigated in culture media and compared. DMF was found to be more efficient than any other compound at the concentration of 200 ppm. The inhibitory activity of DMF against E. coli increased with increasing concentration of DMF. DMF also exhibited more obvious inhibition against E. coli at the initial growth phase than at other phases. The antibacterial ability of DMF showed low stability to heat processing but was less sensitive to pH values. Under conditions of restricted availability of oxygen, E. coli was more sensitive to DMF. The results indicate that DMF may be a potentially effective alternative antimicrobial agent to inhibit E. coli.

Anti-Bacterial Agents↗

PubMed2001

Dehydroevodiamine attenuates beta-amyloid peptide-induced amnesia in mice.

Dehydroevodiamine has been reported to have anticholinesterase activity and an anti-amnesic effect. This study examined the effects of dehydroevodiamine on scopolamine- and beta-amyloid peptide-(25--35)-induced amnesia in mice, using a step-through passive avoidance test. Similarly to the cholinesterase inhibitor, physostigmine (0.03--0.3 mg/kg, i.p.), dehydroevodiamine (0.75--12.0 mg/kg, i.p.) administered 30 min before the training trial, immediately after the training trial, and 30 min before the retention test significantly improved scopolamine- and beta-amyloid peptide-(25--35)-induced amnesia. In beta-amyloid peptide-(25--35)-induced amnesia, the rank order of anti-amnesic potency in these three administration schedules for dehydroevodiamine was different from that for physostigmine. Furthermore, dehydroevodiamine was more potent to improve beta-amyloid peptide-(25--35)-induced amnesia than scopolamine-induced amnesia when administered before the training trial. These results suggested that dehydroevodiamine may have an action other than that of an anticholinesterase and may be a novel and effective ligand for improvement of beta-amyloid type amnesia.

Alkaloids↗

PubMed2001

Morphologic predictors of papillary carcinoma on fine-needle aspiration of thyroid with ThinPrep preparations.

Although the cytologic features of papillary carcinoma of the thyroid are well-known, none is entirely specific. We conducted this study to determine the minimal criteria necessary to achieve 100% specificity for the diagnosis of papillary carcinoma on fine-needle aspiration (FNA). Forty patients with histologically confirmed papillary carcinoma and 17 patients with other thyroid lesions who underwent preoperative FNA at Beth Israel Deaconess Medical Center during a 4-yr period were included in the study. All cytology slides were prepared with the ThinPrep processing technique. Various architectural and nuclear features were evaluated, with a score assigned to each feature, and correlated with the histologic diagnosis of papillary carcinoma. Intranuclear inclusions, papillary and/or sheet arrangements, nuclear grooves, powdery chromatin, nuclear molding, high cellularity, and small nucleoli were significantly associated with papillary carcinoma (P < 0.05). The requirement of any intranuclear inclusions and many nuclear grooves, or a minimum of sum of scores (of the above eight features) of 10, yields 100% specificity and approximately 70% sensitivity. Cases with fewer features can be reported as suspicious or indeterminate for papillary carcinoma. A quantitative/probabilistic approach in the reporting of thyroid FNA provides a practical guide for management of patients with thyroid nodules.

Adult↗

PubMed2001

A predictive model of well-being and self-care for rural elderly women in Taiwan.

A predictive model of well-being and self-care was tested with 284 women aged 60-88 living in rural communities in Taiwan. The variables studied were age, marital status, social class, social support, perceived health, self-care agency, self-care behavior, and perceived well-being. The model was tested by path analysis. The parameters of the model were estimated with the maximum likelihood method. In the refined model, chi2 (12, N = 284) = 15.18, p =.23), 33% of the total variance in well-being was explained by self-care behavior, social support, and perceived health; 66% of the total variance in self-care behavior was explained by self-care agency and social support; 49% of the total variance in self-care agency was explained by social support, perceived health, social class, and age; 14% of the total variance in social support was explained by marital status, social class, and age; and 8% of the total variance in perceived health was explained by social support. The goodness-of-fit index was.99, indicating that the refined model fit the data well. The findings of this study contribute to a greater understanding of this predictive model for application with older women in rural Taiwan.

Adaptation, Psychological↗

PubMed2001

Shear stress-induced nitric oxide release triggers the liver regeneration cascade.

The trigger of the liver regeneration cascade is currently unknown and has been the subject of debate. We hypothesize that, following 2/3 partial hepatectomy (PHX), an increase in the blood flow-to-liver mass ratio results in shear stress-induced nitric oxide (NO) release, which triggers the liver regeneration cascade. Portal venous pressure (PVP), reflecting shear stress in the liver, increased to the same extent following PHX and selective portal vein branch ligation (PVL), a hemodynamic model of PHX, suggesting similar amounts of shear stress in both models. Two indices of the initiation of the liver regeneration cascade were used: proliferative factor (PF) activity in blood 4 h after PHX or PVL and hepatic c-fos mRNA expression 15 min. after PHX or PVL. PF activity and c-fos mRNA expression were increased to similar extents after PHX and PVL, suggesting a similar stimulus in both models. PF activity and c-fos mRNA expression were inhibited by administration of the nitric oxide synthase antagonist, l-NAME, and the NO donor, SIN-1, reversed the inhibition in both models. These results provide support for the hypothesis that a hemodynamic change results in increased shear stress in the liver causing generation of NO, which then triggers the liver regeneration cascade.

Animals↗

PubMed2001

The underlying diseases and follow-up in Taiwanese children screened by urinalysis.

To date, the underlying diseases and follow-up of Taiwanese children screened by urinalysis have not been reported. The grading of urine abnormalities varied from grade A (microscopic hematuria only), grade B (light proteinuria only), grade C (light proteinuria and microscopic hematuria) to grade D (heavy proteinuria). From January 1991 to August 1998, 630 students, aged 6-15 years and with positive urinary screening, were admitted to our hospital for further evaluation. Of these, 573 students had confirmed abnormal findings, 298 were boys, 275 were girls, and 294 students received a renal biopsy and have had regular follow-up visits. This study was designed to retrospectively elucidate: (1) the relationship between grading of urine abnormality and underlying disease; (2) the relationships among hypertension, grading of urine abnormality, and underlying disease; (3) the underlying disease of low serum C3 level; and (4) to determine whether urinary screening progressively decreased the number of students with end-stage renal disease (ESRD) annually. The results show that glomerular nephritis (GN) is still one of the major causes of urinary abnormalities. The most-important secondary GN was systemic lupus erythematosus (SLE) with lupus nephritis. One-quarter of the patients fulfilled at least four of the revised American Rheumatology Association (ARA) criteria for SLE at first administration, while the others who fulfilled only two to three of the revised ARA criteria had gradually developing signs and symptoms of SLE at follow-up. The percentage of SLE patients amongst anti-nuclear antibody (ANA) positive children was 72%. Membranoproliferative GN is very rare. The distribution of hypertension was 8.2% in grade A, 10.7% in grade B, 9.7% in grade C, and 28.9% in grade D urinary abnormality. There were statistical differences between grade D and either grade A or B or C (P<0.05). Lower serum C3 levels were found only in a minority of patients, including those with SLE. In this series, focal segmental glomerular sclerosis (FSGS) and active class IV lupus nephritis patients were found early enough to receive methylprednisolone pulse plus cyclosporine A therapy. To date there have been only 2 cases (5%) of FSGS with impaired renal function, and none of the lupus nephritis patients are in the predialysis stage. In conclusion, GN is still the major cause of urinary screening abnormality. ANA study is indicated in all Chinese students with abnormal urinary screening. The correlations between the severity of proteinuria and hypertension showed more-severe proteinuria in patients with nephritis as well as in those with hypertension.

Adolescent↗

PubMed2001

Analytical models of atherosclerosis.

Atherosclerosis is responsible for approximately 50% of all mortalities in the USA, Europe, and Japan. An innovative approach for investigating atherosclerotic lesions using a thermodynamic model and a boundary value model and an analytical example of a human abdominal aorta vessel with an initial lesion are presented in the paper. Analytical results given by both models propose that increased transient boundary layer thickness and reduced surface energy of adhesion in regions of the arterial branch points play crucial roles in initial lesion formation. This study also improves the understanding of atherosclerotic mechanisms and helps to interpret clinical and experimental results.

Aorta, Abdominal↗

PubMed2001

Phenotypic characteristics of a distinctive multilayered epithelium suggests that it is a precursor in the development of Barrett's esophagus.

A distinctive type of multilayered epithelium (ME) has been described at the neo-squamocolumnar junction and within columnar mucosa in patients with Barrett's esophagus (BE). This epithelium has morphologic and ultrastructural features of both squamous and columnar epithelium. Multilayered epithelium may represent an early or intermediate stage of columnar metaplasia; therefore, we performed this study to determine the morphologic and biologic characteristics of this epithelium and to gain insight into its derivation. Esophageal mucosal biopsies containing ME from 17 patients with BE were evaluated morphologically, stained with a variety of mucin histochemical stains; and also immunostained with antibodies against cytokeratins (CK) 13 (squamous epithelium marker); 14 (basal squamous epithelium marker) 7, 8/18, 19, and 20 (columnar epithelium markers), MIB-1 (proliferation marker); villin (intestinal brush border protein); and TGFalpha, EGFR, pS2, and hSP (enteric proliferation/differentiation regulatory peptides). The results were compared with normal esophageal squamous epithelium, normal gastric cardia epithelium, specialized-type intestinal epithelium (BE), and esophageal mucosal and submucosal gland duct epithelium. Multilayered epithelium expressed a pattern of mucin production (neutral mucin, sialomucin, and sulfomucin in 88%, 100%, and 71% of cases, respectively) and cytokeratin expression (CK 13 and 19 in the basal "squamoid" cells, CK 7, 8/18, 19, and 20 in the superficial "columnar" cells) similar to that of columnar epithelium in BE, and showed a high capacity for cellular proliferation (Ki-67-positive in 88% of cases) and differentiation (TGFalpha, EGFR, pS2 and villin-positive in 100%, 100%, 93%, and 66% of cases, respectively). The mucosal gland duct epithelium showed a similar phenotypic pattern and, in one case, was seen to give rise to ME at the surface of the mucosa. These data provide evidence in support of the hypothesis that ME represents an early or intermediate stage in the development of esophageal columnar metaplasia (BE). The mucosal gland duct epithelium may contain progenitor cells that can give rise to ME.

Adult↗

PubMed2001

Using a focus group study to explore perceptions of health-promoting self-care in community-dwelling older adults.

The purpose of this study was to explore perceptions of health-promoting self-care in community-dwelling older adults. A focus group was conducted to obtain the perceptions and experiences of older adults concerning health-promoting self-care in their daily lives. Twenty-one volunteers from a Golden-Age Association in Kaohsiung City, including 10 males and 11 females, agreed to participate in this study. The mean age of the participants was 73.5 years, with ages ranging from 67 to 83. Three focus group sessions were held and 21 participants participated in all three sessions. Each focus group session lasted from 2.5 to 3 hours. The sessions were audio tape recorded and then verbatim transcripts were used for content analysis. Through a peer discussion, 51 behavioral units were extracted and categorized as five major themes including "balancing", "initiating", "regularizing", "socializing", and "sublimating". The findings can contribute to basic nursing knowledge related to health-promoting self-care and provide the basis for designing nursing strategies to enhance health-promoting self-care for older adults in the community.

Aged↗

PubMed2001

Tumor cell interactions with the microvasculature: a rate-limiting step in metastasis.

Blood vessels facilitate the widespread dissemination of cancer cells in metastasis. Interactions between circulating intravascular cancer cells and the microvasculature involve mechanical contact and transient attachment, mediated by endothelial surface adhesion molecules and their ligands on the neoplastic cells. Initial interactions trigger a sequence of activation pathways that involve cytokines, growth factors, bioactive lipids, and reactive oxygen species produced by the cancer cell or the endothelium. These activation steps elicit the expression of integrin adhesion molecules in cancer cells and the endothelium, matrix metalloproteinases, and chemotactic factors that promote firm attachment of tumor cells to the vessel wall and transvascular penetration. On the other hand, induction of endothelial free radicals can be cytotoxic to cancer cells. Collectively, the sum of these interactions act as a rate-regulating step in the metastatic process.

Biomechanical Phenomena↗

PubMed2001

Concept analysis of well-being.

Traditionally, mortality and morbidity were considered two important indicators of health outcome. Until recently, the measurement of health outcome focused on individuals' subjective perceptions of well-being. Well-being has been popularly used in many scientific disciplines. The definitions of well-being, however, were diverse and inconsistent in previous literature. The ambiguous concept used in research study will impede the development of knowledge and theory. Concept analysis, therefore, is necessary to synthesize the existing views of well-being and distinguish it from other concepts to explicate the meaning of well-being.

Health↗