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Biomedical subjects

H C Lin

Publications and source records attributed to H C Lin.

At least 55 records · Page 3Linked to original sources
PubMed2001

Bacteremia after endoscopic injection of N-butyl-2-cyanoacrylate for gastric variceal bleeding.

BACKGROUND: Cyanoacrylate may form a barrier that prevents bacterial invasion when used in tissue. Because cyanoacrylate polymerizes within seconds on contact with aqueous media, it is used worldwide to arrest gastric variceal bleeding. The aim of this study was to determine the frequency of bacteremia after endoscopic cyanoacrylate injection for gastric variceal bleeding. METHODS: Patients with cirrhosis who underwent endoscopic cyanoacrylate injection for gastric variceal bleeding were included. Patients with cirrhosis who underwent upper endoscopy for nonvariceal upper GI bleeding were recruited as controls. Patients with infection before endoscopy were excluded. Blood was cultured in both groups. Injection needles and endoscope accessory channels were cultured in the cyanoacrylate injection group. RESULTS: More patients injected with cyanoacrylate had positive blood cultures in comparison with the control group (15/47 vs. 1/47, p < 0.0001). In the cyanoacrylate injection group, the volume of blood transfused and Child-Pugh score were factors associated with the occurrence of bacteremia. Most episodes of bacteremia were transient, except for 1 patient who died of sepsis. Most of the microorganisms cultured from blood samples were identical to those cultured from injection needles (65%) and accessory channels (90%). CONCLUSIONS: Endoscopic cyanoacrylate injection for gastric varices does not limit the spread of bacteria. The endoscope accessory channel was the major source of bacteria. Most episodes of bacteremia were transient and uneventful.

Bacteremia↗
PubMed2001

Peppermint oil improves the manometric findings in diffuse esophageal spasm.

BACKGROUND: Diffuse esophageal spasm (DES) is an uncommon condition that results in simultaneous esophageal contractions. Current medical treatment of DES is frequently unsatisfactory. We hypothesized that, as a smooth muscle relaxant, peppermint oil may improve the manometric findings in DES. STUDY: Eight consecutive patients with chest pain or dysphagia and who were found to have DES were enrolled during their diagnostic esophageal manometry. An eight-channel perfusion manometry system was used. Lower esophageal sphincter pressure and contractions of the esophageal body after 10 wet swallows were assessed before and 10 minutes after the ingestion of a solution containing five drops of peppermint oil in 10 mL of water. Each swallow was assessed for duration (seconds), amplitude (mm Hg), and proportion of simultaneous and multiphasic esophageal contractions. RESULTS: Lower esophageal sphincter pressures and contractile pressures and durations in both the upper and lower esophagus were no different before and after the peppermint oil. Peppermint oil completely eliminated simultaneous esophageal contractions in all patients (p < 0.01). The number of multiphasic, spontaneous, and missed contractions also improved. Because normal esophageal contractions are characteristically uniform in appearance, variability of esophageal contractions was compared before and after treatment. The variability of amplitude improved from 33.4 +/- 36.7 to 24.9 +/- 11.0 mm Hg (p < 0.05) after the peppermint oil. The variability for duration improved from 2.02 +/- 1.80 to 1.36 +/- 0.72 seconds (p < 0.01). Two of the eight patients had chest pain that resolved after the peppermint oil. CONCLUSIONS: This data demonstrates that peppermint oil improves the manometric features of DES.

Administration, Oral↗
PubMed2001

Herpes zoster during varicella.

A 4-year-old boy had varicella infection. Two days later vesicular lesions clustered within the left 10th thoracic dermatome. Varicella-zoster virus IgM antibody in serum was positive. He was diagnosed with varicella infection combined with herpes zoster. This is the first case report in the medical literature.

Antibodies, Viral↗
PubMed2001

Oestrogen deficiency causes DNA damage in uterine leiomyoma cells: a possible mechanism for shrinkage of fibroids by GnRH agonists.

OBJECTIVE: To examine whether gonadotrophin-releasing hormone agonist or oestradiol can directly affect DNA in leiomyoma cells. DESIGN: In vitro explant culture of leiomyoma cells. SETTING: University research group. SAMPLE: Leiomyoma cells were cultured from the specimens of four premenopausal women at myomectomy. METHODS: The presence of gonadotrophin-releasing hormone receptor in leiomyoma cells was determined by reverse transcriptase-olymerase chain reaction. Leiomyoma cells were treated with gonadotrophin-releasing hormone agonist or cultured in different concentrations of oestrogen, progesterone or fetal calf serum for one, four or seven days. MAIN OUTCOME MEASURES: Cell number, expression of proliferating cell nuclear antigen, and DNA damage after one, four or seven days of treatment. RESULTS: Gonadotrophin-releasing hormone receptor messenger ribonucleic acid was detected on cultured leiomyoma cells. Leiomyoma cell growth was not affected by the addition of gonadotrophin-releasing hormone agonist or progesterone, but increased with oestrogen or fetal calf serum supplementation. Overexpression of proliferating cell nuclear antigen was prevented in cultures added with oestrogen or fetal calf serum, but not related to gonadotrophin-releasing hormone agonist treatment. Significant decreases in DNA damage as indicated by decreased comet number were found in the leiomyoma cultures treated with oestrogen or fetal calf serum for four and seven days but not with gonadotrophin-releasing hormone agonist or progesterone. Furthermore, 5% fetal calf serum supplementation was more growth supporting and more significantly reduced the comet number than 250 pM 17 beta-oestradiol. CONCLUSION: Cell growth, proliferating cell nuclear antigen expression and DNA damage are dependent on oestrogen or fetal calf serum, but independent of gonadotrophin-releasing hormone agonist or progesterone. Our findings suggest that gonadotrophin-releasing hormone agonist-induced leiomyoma shrinkage may be due in part to a mechanism involving DNA damage, and support the hypothesis that gonadotrophin-releasing hormone agonist exerts its action indirectly through oestrogen action on the tumour level.

Antineoplastic Agents, Hormonal↗
PubMed2001

Hemodynamic effects of a combination of prazosin and terlipressin in patients with viral cirrhosis.

OBJECTIVES: Terlipressin reduces portal pressure in cirrhotic patients mainly through intense splanchnic vasoconstriction that decrease portal venous inflow. Hepatic blood flow may also be reduced by terlipressin. Prazosin (an alpha1-adrenoceptor antagonist) has also been proposed to decrease portal pressure in cirrhotic patients possibly through a decrease in the intrahepatic vascular resistance. The current study was aimed to evaluate whether a combination of prazosin and terlipressin exerts more beneficial effects than terlipressin alone. METHODS: Patients were randomly assigned to receive either a placebo (n = 12) or an oral administration of prazosin 2 mg (n = 12). Thereafter, each patient received an intravenous injection of terlipressin 2 mg. Hemodynamic values were measured basally, 30 min after prazosin or placebo, and 30 min after terlipressin. RESULTS: Placebo administration did not affect any hemodynamic values. Terlipressin administration, on the other hand, resulted in expected changes on the hepatic venous pressure gradient, hepatic blood flow, and systemic hemodynamics. In contrast, prazosin significantly decreased hepatic venous pressure gradient with an increased hepatic blood flow and intrinsic hepatic clearance. After terlipressin administration, a further decrease in hepatic venous pressure gradient was observed with preservation of hepatic blood flow and intrinsic hepatic clearance. The magnitude of decrease in hepatic venous pressure gradient was more profound in patients receiving prazosin plus terlipressin than in those receiving terlipressin alone. However, the magnitude of changes in systemic hemodynamics was no different between the two groups of patients. CONCLUSIONS: The current study showed that a combination of prazosin and terlipressin resulted in a more profound reduction of hepatic venous pressure gradient with a preservation of hepatic blood flow and intrinsic hepatic clearance than did terlipressin alone. However, the combined therapy did not modify the systemic hemodynamic effects exerted by terlipressin.

Antihypertensive Agents↗
PubMed2001

Adaptive vasodilatory response after octreotide treatment.

Despite the suppression of glucagon release, an adaptive response aimed at maintaining vasodilatation after octreotide treatment may exist in portal hypertension. The present study was undertaken to evaluate the possible interaction between endothelium and non-endothelium-derived vasodilators after 1-wk octreotide administration in cirrhotic rats. Rats were allocated to receive either vehicle or octreotide (30 or 100 microg/kg every 12 h subcutaneously). Hemodynamic values, plasma glucagon levels, endothelium-related vasodilatory activities, and aortic endothelial nitric oxide synthase (eNOS) expression were determined after treatment. Octreotide administration decreased plasma glucagon and increased serum 6-keto-PGF(1 alpha) and NOx levels without affecting the hemodynamic values. In cirrhotic rats receiving octreotide, there was a blunt response to either L-NAME or indomethacin administration alone, but this blunt pressor response disappeared after simultaneous administration of the two drugs. Additionally, an increased aortic eNOS expression was observed in cirrhotic rats receiving 1-wk octreotide. It is concluded that 1-wk octreotide treatment did not correct the hemodynamic derangement in cirrhotic rats. The enhanced endothelium-related vasodilatory activity was noted after octreotide treatment that overcame the octreotide-induced hemodynamic effects in portal hypertension.

6-Ketoprostaglandin F1 alpha↗
PubMed2001

DDR2 receptor promotes MMP-2-mediated proliferation and invasion by hepatic stellate cells.

Type I collagen provokes activation of hepatic stellate cells during liver injury through mechanisms that have been unclear. Here, we tested the role of the discoidin domain tyrosine kinase receptor 2 (DDR2), which signals in response to type I collagen, in this pathway. DDR2 mRNA and protein are induced in stellate cells activated by primary culture or in vivo during liver injury. The receptor becomes tyrosine phosphorylated in response to either endogenous or exogenous type I collagen, whereas its expression is downregulated during cellular quiescence induced by growth on Matrigel. We developed stellate cell lines stably overexpressing either wild-type DDR2, a constitutively active chimeric DDR2 receptor (Fc-DDR2), a truncated receptor expressing the extracellular domain, or a kinase-dead DDR2 Cells overexpressing DDR2 showed enhanced proliferation and invasion through Matrigel, activities that were directly related to increased expression of active matrix metalloproteinase 2 (MMP-2). These data show that DDR2 is induced during stellate cell activation and implicate the phosphorylated receptor as a mediator of MMP-2 release and growth stimulation in response to type I collagen. Moreover, type I collagen-dependent upregulation of DDR2 expression establishes a positive feedback loop in activated stellate cells, leading to further proliferation and enhanced invasive activity.

Animals↗
PubMed2001

An Oral Health Survey in Southern China, 1997: background and methodology.

Relatively limited information is available about the oral health in the Guangdong Province of Southern China, the closest neighbor to Hong Kong. The study intended to explore the oral health status, knowledge, attitudes, and dental care utilization in the Guangdong population as a basis for formulating strategies for oral health prevention and treatment. Through multi-stage stratified and quota-sampling, individuals from urban as well as rural communities were selected (5- to 6-; 12-; 35- to 44-; and 65- to 74-year-olds; total N = 6251). Structured interviews and clinical examinations were performed. Inter-examiner reliability was high (kappa = 0.60-0.96). Samples of community water were taken for fluoride assessment. Overall, the sample surveyed was acceptably representative of the population, with some under-representation of rural residents and agricultural workers. Re-weighting was performed in appropriate analyses. The data analysis model used in the Second International Collaborative Study was used as a guide for the present data analysis. This approach has not previously been used on a Mainland Chinese population.

Adolescent↗
PubMed2001

Oral health knowledge, attitudes, and practices of Chinese adults.

Only recently have behavioral aspects been taken into consideration in oral health studies in China; thus, relevant information on perceptions in adult Chinese about oral health care is inadequate. In 1996-97, a large-scale oral epidemiological study was conducted in Southern China. Among its objectives were to describe the oral health knowledge, attitudes, and practices of the urban and rural adults living in Southern China and to analyze the influence of selected demographic and socio-economic factors. From 8 urban and 8 rural communities in Guangdong Province, 1,573 35- to 44-year-olds and 1,515 65- to 74-year-olds were sampled. Specially trained interviewers from the staff of local government or hospitals conducted face-to-face structured interviews. Almost all of the middle-aged and more than 90% of the dentate elderly surveyed claimed that they brushed their teeth every day and used toothpaste during toothbrushing, but awareness about fluoride content was lacking. The respondents had poor oral health knowledge but positive attitudes toward oral health, providing a basis for more community-based oral health education programs, especially targeting adults who are less-well-educated and have fewer socio-economic advantages.

Adult↗
PubMed2001

Utilization of dental services in Southern China.

A population's utilization of dental services is an important parameter in oral health care planning, which has rarely been studied in China. The objectives of this report were to describe the dental service utilization pattern of middle-aged and elderly Chinese and to analyze the influence of selected variables on the use of dental services. A Guangdong Province population of 1,573 35- to 44-year-olds and 1,515 65- to 74-year-olds recruited from urban and rural communities was interviewed in their local dialect. It was found that 23% of the middle-aged and 24% of the elderly subjects had visited a dentist within the preceding year. The two most commonly cited reasons for not having seen a dentist for at least 3 years were: no perceived need, and no serious dental problems. Among subjects who had visited a dentist within 3 years, the 3 most commonly received treatments were: fillings, extractions, and dental prostheses. Furthermore, a logistic regression analysis showed that women, subjects who lived in urban areas, were better educated, were wealthier, and had better oral health knowledge were more likely to be a recent dental service user. In conclusion, dental service utilization among the adult Southern Chinese was found to be low, problem-driven, and influenced by some socio-economic factors.

Adult↗
PubMed2001

Coronal and root caries in Southern Chinese adults.

Southern China is the most prosperous part of China, but information useful for oral care planning is very limited. A large-scale epidemiological survey was conducted in 1996-97. The objectives of this report were to describe the coronal and root caries of the adult Southern Chinese and to analyze the influence of selected demographic and socio-economic factors on the disease pattern. A total sample of 1,573 35- to 44-year-olds and 1,515 65- to 74-year-olds from 8 urban and 8 rural survey sites in Guangdong Province participated in an oral health interview and underwent clinical examination. World Health Organization examination procedures and diagnostic criteria were used. The weighted mean DMFT scores of the middle-aged and the elderly subjects were 4.8 and 16.1, respectively. People living in rural areas had a higher DMFT score than those living in urban areas (4.9 vs. 4.3 in the 35- to 44-year-olds and 16.5 vs. 14.7 in the 65- to 74-year-olds). In both age groups, MT was the major component of the DMFT score. Analysis of covariance showed that women and those who were economically less well off had higher DMFT scores in both age groups. The weighted prevalence rates of decayed/filled roots were 12% and 37%, with a mean of 0.2 and 0.7 teeth affected, in the middle-aged and the elderly, respectively. In conclusion, socio-economic factors had a considerable effect on the dental caries status of adults in Southern China.

Adult↗
PubMed2001

Periodontal conditions in adult Southern Chinese.

Periodontal diseases remain a concern in adult populations, but there have been no systematic descriptions of periodontal conditions, which have included periodontal attachment loss, among Southern Chinese. The main aim of this report is to describe the periodontal conditions in adult Chinese and to investigate factors that may have influenced periodontal attachment loss. Subjects were recruited from urban and rural survey sites throughout Guangdong. In total, 1,572 35- to 44-year-old subjects and 1,286 65- to 74-year-old subjects completed a structured interview and underwent a periodontal examination, which included the Community Periodontal Index (CPI) and periodontal Attachment Loss (ALoss) recordings. Calculus was found as the highest CPI score in 61-68% of the 35- to 44-year-old subjects and in 54-57% of the 65- to 74-year-olds. Shallow pockets were found as the highest CPI score in about one-third of both the urban and the rural subjects in both age groups, and deep pockets in 3-7% of the subjects. ALoss was more prevalent than pockets in both age groups. On the basis of the ALoss recordings, about one-third of the subjects in both age groups were categorized as exhibiting considerable ALoss for their age. In both age groups, logistic regression analysis indicated that being male, wearing partial dentures, and reporting less frequent toothbrushing were found to be associated with considerable ALoss.

Adult↗
PubMed2001

Oral mucosal lesions in adult Chinese.

The objectives of this analysis were to determine the prevalence of oral mucosal lesions (OML) among adults in Southern China and to determine possible associations between OML and reported tobacco-smoking and alcohol-drinking habits. The sample consisted of 1,573 35- to 44-year-old and 1,515 65- to 74-year-old Chinese from both urban and rural areas of Guangdong Province. The subjects were interviewed by trained interviewers and underwent a clinical examination of the oral mucosa performed according to WHO guidelines. A specially prepared color atlas of OML was used for lesion recognition and confirmation during the survey. Among the 35- to 44-year-old subjects, the overall prevalence of OML was found to be 13% in urban men, 6% in urban women, 15% in rural men, and 4% in rural women. The corresponding figures for the 65- to 74-year-olds were 22%, 12%, 26%, and 19%. Tongue lesions and white lesions were relatively common, but denture-related lesions were not. No malignancies or erythroplakia was observed. Age and gender were found to relate to the occurrence of OML. In elderly men, smoking was significantly (p < 0.05) associated with some white lesions and tongue lesions, and alcohol drinking was also associated with some white lesions. In conclusion, tongue lesions and white lesions were relatively common in men, but pre-cancerous lesions were not prevalent.

Adult↗
PubMed2001

Tooth loss, occluding pairs, and prosthetic status of Chinese adults.

The objectives of this analysis were to describe the numbers of teeth lost and those indicated for extraction, dental prosthetic status, and occluding tooth pairs among adults in Southern China and to investigate factors affecting tooth mortality. A sample consisting of 1,573 35- to 44-year-old and 1,515 65- to 74-year-old urban and rural Chinese was examined clinically by calibrated examiners. Teeth not present for any reason were defined as missing (MT). The sum of MT and teeth indicated for extraction (IMT) was defined as adjusted missing teeth (AMT). Only 4.4% of the urban and 3.4% of the rural 65- to 74-year-olds were edentulous. MT were not significantly different between urban and rural residents, but more IMT were found in rural residents. Women, those who had a lower education level, and those who were less wealthy had more AMT in both age groups. Smoking was found to be associated with AMT in the 35- to 44-year-olds. Eighteen percent of the urban and 27% of the rural elderly had no occluding tooth pairs after IMT were accounted for, and only 38% and 30%, respectively, had 10 or more occluding pairs. Fifty-one percent of the urban and 43% of the rural elderly were found to have some form of dental prostheses in either jaw. A partial denture was more common in urban residents in both age groups.

Adult↗
PubMed2001

A community-based caries control program for pre-school children using topical fluorides: 18-month results.

Dental caries in Chinese pre-school children is common, and restorative treatment is not readily available. This prospective controlled clinical trial investigated the effectiveness of topical fluoride applications in arresting dentin caries. We divided 375 children (aged 3-5 yrs) with carious upper anterior teeth into five groups. Children in the first and second groups received annual applications of silver diamine fluoride solution (44,800 ppm F). NaF varnish (22,600 ppm F) was applied every three months onto the lesions of children in the third and fourth groups. For children in the first and third groups, soft carious tissues were removed prior to fluoride application. The fifth group was the control. We followed 341 children for 18 months. The mean numbers of new caries surfaces in the five groups were 0.4, 0.4, 0.8, 0.6, and 1.2, respectively (p = 0.001). The respective mean numbers of arrested carious tooth surfaces were 2.8, 3.0, 1.7, 1.5, and 1.0 (p < 0.001).

Analysis of Variance↗
PubMed2001

Synthesis, antiplatelet and vasorelaxing effects of monooxygenated flavones and flavonoxypropanolamines.

A series of flavones and flavonoxypropanolamines were synthesized and tested in-vitro for their ability to inhibit aggregation of washed rabbit platelets and human platelet-rich plasma (PRP), and for vasoconstriction of rat thoracic aorta. The various substituted positions of the hydroxyl group in flavone ring B and the various oxypropanolamine side chains substituted at position C-2' of flavone modified the antiplatelet effects. All the compounds tested in human PRP showed significant inhibition of secondary aggregation induced by adrenaline (epinephrine), suggesting that the antiplatelet effect of these compounds is mainly due to an inhibitory effect on thromboxane formation. Compounds 11 and 12 also had potent vasorelaxant effects in rat thoracic aorta. Phenylephrine- and high-K+-induced 45Ca2+ influx in aorta were both inhibited by the selected compound 11. This result indicates that the inhibitory effect of 11 on the contractile response caused by high-K+ medium and noradrenaline (norepinephrine) in rat thoracic aorta is mainly due to inhibition of Ca2+ influx through both voltage-dependent and receptor-operated Ca2+ channels.

Animals↗
PubMed2001

Hemodynamic effects of synephrine treatment in portal hypertensive rats.

Synephrine, a sympathomimetic alpha1-adrenoceptor agonist, has been shown to induce dose-dependent portal hypotensive effects after acute intravenous infusion. The present study was undertaken to investigate the hemodynamic effects of 8-day administration of synephrine in portal hypertensive rats. Portal hypertension was induced by either partial portal vein ligation (PVL) or bile duct ligation (BDL). Portal hypertensive rats were allocated into one of two groups: vehicle group (0.1 N HCl, 0.5 ml/12 h) or synephrine group (1 mg/kg per 12 h), with 7 rats in each group. Synephrine or vehicle was administered by gavage into PVL and BDL rats for 8 consecutive days. Systemic as well as splanchnic hemodynamic parameters were measured thereafter. Synephrine significantly ameliorated the hyperdynamic state in both PVL and BDL rats. The portal venous pressure in PVL and BDL rats (-13.5% and -10.1%, respectively), portal tributary blood flow (-19.5% and -20.4%) and cardiac index (-12.1% and -18.8%) were significantly reduced, while mean arterial pressure (10.4% and 23.4%) and systemic (26.3% and 51.0%) as well as portal territory (47.1% and 67.7%) vascular resistance were enhanced by treatment of synephrine as compared with vehicle treatment. Our results showed that eight-day administration of synephrine exerted beneficial hemodynamic effects in two models of portal hypertensive rats.

Adrenergic alpha-Agonists↗