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Biomedical subjects

F Hu

Publications and source records attributed to F Hu.

At least 55 records · Page 3Linked to original sources

[The relationship between Helicobacter pylori and expression of c-met oncogene in gastric precancerous lesions].

OBJECTIVES: To determine whether there is a relationship between the presence of H. pylori and alteration of c-met oncogene and to estimate the role of H. pylori in the development of gastric carcinoma. METHODS: 110 patients with histopathologically proven chronic gastritis were studied. We demonstrated expression and overexpression rates of c-met oncogene by using immunohistochemical staining. RESULTS: For chronic superficial gastritis, chronic atrophic gastritis, intestinal mataplasia and dysplasia, the expression rates were 22.2%, 44.1%, 67.5% and 61.9%. The overexpression rates were 5.5%, 26.4%, 37.8% and 38.1% respectively. The positive rates of c-met oncogene protein were high among patients infected with H. pylori than those with no H. pylori infection (63% vs 32%). In the precancerous lesions of cellular atrophy, intestinal mataplasia and dysplasia, the expression rates of H. pylori positive patients were higher (68.9%) than those of H. pylori negative patients (30.5%) (P < 0.05). CONCLUSIONS: H. pylori is involved in the expression of c-met oncogene.

Female↗

[Determination of avermictin in avermictin tablet by high performance liquid chromatography].

A method for the separation and determination of avermictin in avermictin tablet by reversed-phase high performance liquid chromatography (RP-HPLC) was developed. Operating conditions were as follows: TSK-GEL C18 column, 250 mm x 4.6 mm i.d., MeOH-H2O (75:25, V/V) mobile phase with a flow rate of 1.0 mL/min, and UV detection at 245 nm. The results showed that the active constituents avermictin B1a and B1b can by separated effectively. The relative standard deviations were 2.56% and 1.31%, respectively (n = 6). The method is accurate, rapid and simple, and provides a scientific basis for industrial production and quality control of avermictin tablet.

Animals↗

Endothelin reactivity and receptor profile of pulmonary vessels in postobstructive pulmonary vasculopathy.

Chronic ligation of one pulmonary artery results in pulmonary vascular remodeling and bronchial angiogenesis, collectively known as postobstructive pulmonary vasculopathy (POPV). To determine whether the reactivity of pulmonary vessels to endothelins (ET) was altered in POPV and to explore potential mechanisms, we ligated the left main pulmonary artery of 18 rats. Four weeks later, using a lung explant technique, we compared POPV lungs with controls for contractile responses of intrapulmonary vessels to ET-1 and ET-3 and for relaxant responses to ET-1 and sodium nitroprusside (SNP) after precontraction with U-46619. Morphometric measurements were made on vessels studied pharmacologically. Competition receptor binding studies with 125I-labeled ET-1 and unlabeled ET-1 and BQ-123 were performed using membrane proteins of pulmonary vessels. We found, in arteries, that contractile responses to ET-1 and ET-3 were significantly increased and that relaxant responses to ET-1 but not to SNP were reduced; in veins, only relaxation to SNP was increased. Morphometry showed that arteries and veins in POPV had reduced diameters without altered muscle thickness. Receptor binding studies showed that the proportion of ETA receptors in arteries was significantly increased in POPV (66%) vs. controls (54%). We conclude that, in POPV, the increase in reactivity to ET-1 and ET-3 is primarily related to an augmented proportion of ETA receptors.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

[The relationship of the permeability coefficients of testosterone with solubility parameters of vehicles].

The effects of vehicles on the penetration through rat skin of testosterone were investigated. The solubilities of testosterone in various vehicles and the fluxes through rat abdomen skin had been determined. The solubility parameters of testosterone (delta i) and vehicles (delta v(n)) were calculated by Hildebrand's method. There was a good inverse parabola correlation between the log permeability coefficients (logp) and (delta v(n)). When delta v(n) approched delta i the permeability coefficients of testosterone approched the minimum as its limit.

Animals↗

Impact mass chemotherapy with praziquantel on schistosomiasis control in Fanhu village, People's Republic of China.

The paper describes the endemic situation of schistosomiasis japonica in Fanhu village, Poyang Lake region, China and the effect of the strategy of combining annual mass chemotherapy with health education on schistosomiasis control in the community. The results showed that the prevalence of infection with schistosome reduced form 26.0% in 1992 to 10.7% in 1994, the intensity of infection in residents decreased from 1.92 in 1992 to 0.55 in 1994 and the condition of hepatomegaly, splenomegaly and liver fibrosis also improved after chemotherapy in the individuals in the case prospective study. Moreover, the future strategies of schistosomiasis control in this area have been suggested according to the transmission of schistosomiasis in the lake region and the effect of anti-schistosomiasis control indifferent populations.

Adolescent↗

[A study on polycyclic aromatic hydrocarbon-DNA adduct in lung cancer patients exposed to indoor coal-burning smoke].

The objective of this study is to explore the etiology and early risk evaluation of lung cancer in Xuanwei County, Yunnan Province of China. Polycyclic aromatic hydrocarbon (PAH)-DNA adduct in brushing cells from fibrobronchoscopy was determined in 30 cases with lung cancer in Xuanwei County and 10 controls in Kunming, Yunnan Province by 32P-postlabelling assay. Results showed that PAH-DNA levels in lung cancer patients of Xuanwei County were much more higher than those in controls. It suggested that air pollution caused by indoor coal-burning associated directly with the occurrence of lung cancer, and detection of DNA adduct could be used as an indicator for its risk assessment in population.

Air Pollution, Indoor↗

Shedding of L-selectin as a mechanism for reduced polymorphonuclear neutrophil exudation in patients with the systemic inflammatory response syndrome.

BACKGROUND: It has been recently shown that patients with the systemic inflammatory response syndrome (SIRS) have reduced neutrophil exudation. OBJECTIVE: To determine whether reduced neutrophil exudation, seen in patients with SIRS, is related to differential expression of cell adhesion molecules (CAMs), by studying endothelial and neutrophil CAM expression. SETTING: A tertiary care surgical intensive care unit in a university teaching hospital. DESIGN: Twenty-six patients with SIRS were compared with 18 healthy age-matched control subjects. Blister-type skin windows were created. Exudative neutrophils were harvested, and CAM expression was quantitated by using flow cytometry. Endothelial CAM expression was studied with immunohistochemical methods by using skin biopsy specimens that were taken following subdermal injections of saline solution or tumor necrosis factor alpha. RESULTS: Despite a significant reduction in neutrophil exudation in patients, we found no difference in the baseline expression of the endothelial intercellular adhesion molecule 1, P-selectin, or E-selectin in patients vs that in control subjects. There was a significant increase in E-selectin staining in response to recombinant human tumor necrosis factor alpha in patients with SIRS, but not in control subjects. However, up-regulation of P-selectin did not occur in patients in response to recombinant human tumor necrosis factor alpha, as was observed in control subjects. L-selectin expression on circulating neutrophils was lower in patients than in control subjects, while soluble serum L-selectin levels were higher. CONCLUSIONS: Alterations in neutrophil L-selectin, not endothelial CAMs, are important in decreased neutrophil exudation. Reduced levels of neutrophil L-selectin associated with increased levels of serum L-selectin in patients with SIRS suggest premature intravascular shedding of neutrophil L-selectin. This would compromise the initial interaction between neutrophils and the endothelium, and, consequently, impede exudation.

Case-Control Studies↗

Production of a recombinant protein from Alternaria containing the reported N-terminal of the Alt a1 allergen.

Allergen content of extract derived from Alternaria is somewhat variable. Allergenic molecules from Alternaria that appear as differing molecular size bands on IgE probed immunoblots may have a great deal of sequence homology and differ only in the length of the amino acid chain. One method to study this problem is to produce recombinant proteins from Alternaria. To explore these possibilities, the following experiments were performed. A strain of Alternaria was grown on minimum salts and glucose in a fermentation container with constant stirring and aeration. Rapidly expanding mycelia were removed from the culture and mRNA was extracted. Purified mRNA was reacted with reverse transcriptase and an aliquot of first copy single strand DNA was enriched for the presence of DNA coding for an Alternaria allergen by PCR amplification. Modified DNA was then spliced into lambda gt11 phage and yielded a recombinant library with 10(5) PFU. The library was screened for the presence of allergenic proteins using IgE containing human sera from Alternaria-sensitive patients. Positive plaques were cloned. PCR analysis of positive clones using an oligonucleotide from the reported N-terminal sequence of Alt a1 indicated an insert of 295 base pairs. Sequence analysis yielded a reading frame containing 84 amino acid and confirmed that this segment contained the code for the reported N-terminal amino acid sequence of Alt a1. A computer search for this sequence found no homologous proteins in the Entrez sequences. Northern blotting studies on RNA purified from nine strains of Alternaria with the radiolabeled 247 BP DNA fragment indicated that this sequence was present in all strains. The 247 BP nucleotide was spliced into the Pflag vector and clones containing insert in the proper reading frame were identified. The presence of recombinant protein in the clones was verified by SDSPAGE time studies. Protein produced in time studies was shown by immunoblotting and sandwich EIA to bind human IgE from Alternaria sensitive patients. This recombinant protein, containing amino acid sequence for Alt a1, is bound by human IgE and therefore should be useful as a model for studying allergy to the native Alternaria glycoprotein. Further research should define where this sequence occurs in the Alternaria genome and should determine the sequence of the entire protein.

Allergens↗

Experimental study on the early efficacy of excimer laser with adjunctive balloon angioplasty in dog's femoral artery.

The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusion from 12 dogs were subject to angiography. At first excimer laser angioplasty was done followed by balloon angioplasty. The diameter and residual stenosis of revascularized vessel were measured. The result showed that 17 out of 20 vessels (85%) were revascularized. The diameter of revascularized vessel by excimer laser were 1.22 +/- 0.14 mm, while residual stenoses were 54% +/- 5%. After adjunctive balloon angioplasty the diameter and residual stenoses were 2.04 +/- 0.16 mm and 20% +/- 7% respectively (P < 0.05 and P < 0.01). Complication in form of vasoperforation occurred in 3/20 vessels (15%). It is concluded that China- manufactured excimer laser angioplasty is effective when used for revascularization. While the reduction of narrowing and residual stenoses was enhanced after adjunction of balloon angioplasty. This method can be employed in treating peripheral occlusive disease effectively and safely.

Angioplasty, Balloon, Laser-Assisted↗

[The effects of teprenone on the ulcer healing rate and the quality of healing in the treatment of active gastric ulcers].

UNLABELLED: One hundred and six patients with active gastric ulcer proven by endoscopy were randomly allocated to receive cimetidine 800 mg at bedtime + teprenone 50 mg thrice daily; or cimetidine 800 mg at bedtime alone in a trial comparing the ulcer healing rate and the quality of healing at 4 or 8 weeks. At 4 weeks 72.4% (42/58) of those on cimetidine + teprenone and 52.1% (25/48) on cimetidine alone had ulcers healed in comparison of 93.1% (54/58) and 89.6% (43/48) respectively at 8 weeks. The difference was significant at 4 weeks, indicating the ulcer heal more rapidly in the combination therapy group. The stage S2 achievement rates were 34.5% (20/58) and 10.4% (5/48) at 4 weeks (P < 0.05), 50.0% (29/58) and 20.8% (10/48) at 8 weeks (P < 0.05) respectively, indicating the quality of ulcer healing was much better in the combination therapy group. The gastric mucosal hexosamine levels increase significantly after treatment (17.79 +/- 2.00 micrograms/mg) as compared to that before treatment (14.27 +/- 2.47 micrograms/mg) in the combination therapy group, indicating that teprenone stimulates macromolecular glycoprotein synthesis in gastric mucosa. This is thought to be a significant factor in the healing process of gastric ulceration. CONCLUSION: It is reasonable to administer teprenone, an agent increasing mucosal resistance, concurrently with H2 blockers in the treatment of active gastric ulcers.

Anti-Ulcer Agents↗

Human exposure and dosimetry of polycyclic aromatic hydrocarbons in urine from Xuan Wei, China with high lung cancer mortality associated with exposure to unvented coal smoke.

The lung cancer mortality rate in Xuan Wei (XW) county, China, is 5-fold the national average of China; the rate for women is the highest in China. Xuan Wei residents have been exposed to unvented coal or wood smoke during cooking or heating in homes. This study investigated indoor air exposure and dosimetry of polycyclic aromatic hydrocarbons (PAHs) in XW residents using smoky coal. Indoor air particles collected during cooking in four XW homes using smoky coal were analyzed for PAHs by GC/MS. Urine samples from 16 XW non-smoking women and six XW smoking men, eight Kunming non-smoking controls and four non-smoking Chinese American controls were analyzed for PAHs and hydroxy-PAHs by GC/MS. The results showed that XW residents were exposed to PAHs at occupational levels. The potent carcinogen, dibenzo[a,l] pyrene (4.9 +/- 1.3 micrograms/m3) was found in the indoor air of the XW homes. The levels of urinary hydroxy-PAH were higher than those of the parent compounds in most subjects, indicating that most PAHs were metabolized. In urine, the mean levels of 9-hydroxy BaP (BaP) and BaP are 1.5 +/- 0.5 mumol/mol creatinine and 0.5 +/- 0.3 microns/mol for XW men, 1.9 +/- 0.9 microns/mol and 0.5 +/- 0.3 microns/mol for XW women. In general, the levels of PAH metabolites in urine were higher in the XW residents than in Kunming and Chinese American controls; however only the concentrations of 9-hydroxy BaP in XW women showed statistically significant difference from the Kunming controls (P < 0.05 by ranking test). The mean levels of 3 methylated-PAHs analyzed were 4.8-fold higher than that of the parent PAHs in XW subjects. This is consistent with previous findings that alkylated PAHs are the major mutagens in the XW indoor air and may be etiologically important in XW lung cancer.

Air Pollution, Indoor↗

A unique, predominant hepatitis C virus variant found in an infant born to a mother with multiple variants.

To demonstrate vertical transmission of hepatitis C virus (HCV) from an HCV-infected, non-human immunodeficiency virus type 1-infected mother to her infant and to assess the distribution of viral species in the mother and infant, the hypervariable region of the gene encoding the putative envelope glycoprotein E2 (E2HV) was sequenced in three mothers and one mother-infant pair. The data indicate that (i) quasi-species distributions of HCV E2HV variants were found in all four mothers, (ii) a single predominant HCV E2HV variant was found in the infant of a mother shown to have nine predominant E2HV variants, and (iii) the infant's E2HV variant was highly related to, but not identical with, the nine variants identified in the mother at the time of birth. These findings indicate that HCV is transmitted from mother to infant and raise the possibility that the transmission occurs in utero.

Amino Acid Sequence↗

Optimal diaphragmatic blood perfusion.

The intrabreath time course of phrenic artery blood perfusion (Qpha) was studied in five anesthetized dogs. The diaphragm was paced with submaximal levels of stimulation at various duty cycles (DC) to achieve tension-time index below and above the fatigue threshold (0.03-0.60). Left Qpha was measured via Doppler technique during control (inactive diaphragm) and during two submaximal levels of bilateral phrenic nerve stimulation sustained for 1 min. Measurements were done when Qpha reached steady state in each run. The frequency of pacing of each run was 10/min, and the DC ranged from 0.1 to 0.9 in 0.1 increments. Shortening of costal and crural segments was measured by sonomicrometry. It was found that Qpha during the diaphragmatic contraction phase (QphaC) was a sigmoidal function of DC and was not affected by the levels of transdiaphragmatic pressure (Pdi) explored (34-64% of maximal Pdi). Qpha during the diaphragmatic relaxation phase (QphaR) was a parabolic function of the DC, reaching an optimal value at DC of approximately 0.3 at any given Pdi. QphaR increased significantly with the preceding level of Pdi. QphaT (the sum of QphaC and QphaR) was a parabolic function of DC, reaching peak values at DC of 0.4-0.6 and then decreasing. This function was similar at two levels of Pdi. Post-pacing hyperemia was directly related to tension-time index greater than 0.20.

Animals↗

Restriction of regional blood flow and diaphragmatic contractility.

We have tested the hypothesis that the diaphragmatic head-to-head arterial anastomosis system should maintain adequate diaphragmatic function even during occlusion of some of its arteries. In six anesthetized open-chest dogs, left phrenic vein blood flow (Qphv) was measured by pulsed Doppler flowmetry. Contractility was measured by sonomicrometry in the left costal and crural diaphragm. The diaphragm was paced for 15 min by continuous bilateral supramaximal phrenic nerve stimulation. In five separate runs the following arteries were occluded at minute 5: 1) left phrenic artery, 2) internal mammary artery (IMA), 3) left phrenic artery and IMA, 4) descending aorta, and 5) descending aorta and IMA. Occlusion was then released at minute 10 of the run. In runs 1-3 there were no changes in contractility in costal or crural diaphragm and no changes in Qphv. However, in runs 4 and 5, Qphv decreased to 55.2 +/- 7.4 and 24.0 +/- 6.5% of control values, respectively. In run 4, percent maximum shortening from functional residual capacity (%LFRC) of the crural diaphragm decreased by 39.1%, while %LFRC of the costal diaphragm increased by 41.4% and abdominal pressure decreased by 47.0%. In run 5, abdominal pressure decreased by 53.5% and %LFRC of the crural and costal diaphragm decreased by 45.5 and 5.8%, respectively. Also relative postocclusion hyperemia was greater in run 5 (64.8%) than in run 4 (40.2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗