Search PubMed⌕ Search

Biomedical subjects

L H Cheng

Publications and source records attributed to L H Cheng.

At least 19 recordsLinked to original sources
PubMed2004

Suppression of human peripheral blood lymphocyte proliferation by immortalized mesenchymal stem cells derived from bone marrow of Banna Minipig inbred-line.

This study sought to investigate whether mesenchymal stem cells (MSC) derived from Banna Minipig Inbred-line (BMI-MSC) suppressed human peripheral blood lymphocyte (hPBLs) proliferation in a one-way mixed lymphocyte reaction system. BMI-MSC failed to stimulate proliferative responses by hPBLs, which were activated by allogenic endothelial cells, BMI-PBLs and non-specific mitogenic stimuli. Furthermore, BMI-MSC also suppressed proliferation of hPBLs stimulated by mismatched allogenic, as well as xenogenic PBLs, and the mitogenic stimulus ConA. The suppression occurred in dose-dependent fashion when the ratio of hPBLs to BMI-MSC varied from 1 to 5 fold; fewer, BMI-MSC (0.001 to 0.01 times) showed no obvious suppression. When BMI-MSC were added to hPBLs stimulated for 72 hours, the proliferative suppression was still evident. Addition of anti-FasL or anti-TGF-beta1 antibody attenuated the proliferative suppression, while antibody against IL-10 had no effect on it. Further immunofluorescence analysis demonstrated that FasL and TGF-beta1 constitutively expressed BMI-MSC. These findings suggest that BMI-MSC suppress hPBLs proliferation relying on FasL and TGF-beta1 mediated pathways.

Animals↗
PubMed2001

Ubiquitin and malignant transformation of oral mucosa.

BACKGROUND: Ubiquitinylation is a cyclical process operating in all cells to target specific proteins (eg, p53) for degradation. Abnormal accumulations of ubiquitinylated proteins have been identified in colorectal carcinoma. This study investigated abnormal ubiquitinylated proteins and changes in ubiquitinylation patterns associated with malignant transformation of oral tissue. METHODS: Twenty-three fresh specimens of normal, premalignant, oral squamous cell carcinoma (SCC), and its adjacent normal mucosa were collected for immunohistochemistry with anti-ubiquitin and anti-UbcH7 (a human ubiquitin-conjugating enzyme) antibodies using light and electron microscopy and protein analysis by Western blot. RESULTS: Ubiquitin and UbcH7 were observed in both nucleus and cytoplasm of normal, "premalignant" and malignant tissues of oral mucosa using immunoelectron microscopy. However there was no change in their distribution pattern. CONCLUSIONS: The lack of demonstrable difference in distribution pattern of ubiquitin enzymes indicates that at present, ubiquitin cannot be used as a diagnostic marker for malignant transformation of oral SCC.

Biomarkers, Tumor↗
PubMed1998

Orthognathic surgery: the patients' perspective.

It is often thought that patients seek combined orthodontic and surgical treatment for predominantly aesthetic reasons, with functional concerns being secondary. To find out whether patients were more satisfied with appearance than function after treatment, all 165 patients who had orthognathic operations during the 11-year period 1983-94 were sent a questionnaire; 139 responded (84%). Rating on a visual analogue scale showed a high level of satisfaction for both appearance (mean score 6.78) and function (mean score 7.24) (Wilcoxon test, P = 0.046). This indicates that orthognathic surgery is not merely done for aesthetic reasons, but is important when combined with orthodontic treatment in correcting severe malocclusions, which appreciably improve the ability to chew.

Adolescent↗
PubMed1998

Natural deaths while driving: would screening for risk be ethically justified?

OBJECTIVES: To determine the epidemiology and the underlying pathological conditions of natural deaths among motor vehicle drivers. Sudden death while driving may cause damage to properties, other vehicles or road users. Although the Medical Commission on Accident Prevention recommended restrictions to drivers at risk of sudden death due to their medical conditions, these restrictions are useless if they do not result in greater safety to the public. DESIGN: A retrospective study of natural deaths of motor vehicle drivers. SETTING: Natural deaths of motor vehicle drivers reported to the coroner for Birmingham and Solihull. SUBJECTS: 86 consecutive natural deaths of motor vehicle drivers in a five-year period between 1984 and 1988. RESULTS: Of the 86 fatalities reviewed, 80 (93%) sudden deaths were caused by ischaemic heart disease. Fifty vehicles were involved in collision with 32 properties, 20 other vehicles and six pedestrians. Fifty-one out of 80 cardiac deaths had past cardiac history and three had reported chest pain prior to the sudden death. CONCLUSION: An applied normative ethical assessment based on the basic moral principles of autonomy, justice, beneficence and non-maleficence are discussed. We conclude that medical screening of drivers has little benefit for the drivers or other persons.

Adult↗
PubMed1998

Carbon dioxide laser surgery for snoring: results in 192 patients.

Laser-assisted uvulopalatoplasty has been introduced as an alternative to uvulopalatopharyngoplasty for treatment of snoring and potentially of obstructive sleep apnea syndrome. Between July 1994 and June 1996, 192 patients underwent 227 laser-assisted uvulopalatoplasty procedures. Loud habitual snoring was evaluated in 42 women (21.8%) and 150 men (78.2%), who were then treated with laser-assisted uvulopalatoplasty. Among the 192 patients (227 procedures), with ages from 18 to 81 years (mean 42.6 years), 15.6% (30 patients) had more than one laser-assisted uvulopalatoplasty treatment. In our series, 80 patients (42.1%) had a history of obstructive sleep apnea syndrome in addition to snoring. Laser-assisted uvulopalatoplasty treatment in patients with loud snoring resulted in elimination of snoring in 61%, partial improvement of snoring in 26%, and no improvement in 13%. The overall success rate was 87%. The mean body mass index was significantly higher in the patients with no response after the operation (27.9 kg/m2) compared with that in the patients with a good response (25.9 kg/m2). Obese (body mass index >30 kg/m2) patients were more likely to have no response to laser-assisted uvulopalatoplasty treatment of snoring than patients with an ideal body weight (body mass index <25 kg/m2) (p < 0.01). We conclude that the body mass index may be of significant value in the postoperative success rate of laser-assisted uvulopalatoplasty for the treatment of snoring.

Adolescent↗
PubMed1998

[Effects of electroacupuncture on the expression of estrogen receptor protein and mRNA in rat brain].

In order to show some light on the possible molecular mechanism of the effects of acupuncture on the hypothalamic-pituitary-ovarian axial function, radioimmunoassay (RIA), RNA dot blot and Northern blot, monoclonal antibody immuno-histochemistry and computer image analysis technique were used to study the effects of electroacupuncture (EA) on the blood level of estradiol (E2) and the expression of estrogen receptor protein and mRNA in the ovariectomized rat brain. The results show that ovariectomy induced a decrease of blood E2 level and increase of the expression of estrogen receptor protein and mRNA in the brain. All these effects could be remarkably reversed by previous EA treatment of ovariectomized rats. EA in intact rat, however, had no effects on blood E2 and expression of estrogen receptor. The above results suggest that EA at some effective acupoints may activate the production of body estrogen, resulting in a long term increase or suppression at the level of gene(s) expression and consequent normalization on the dysfunction of hypothalamic-pituitary-ovarian axis.

Animals↗
PubMed1996

Helicobacter pylori in dental plaque and gastric mucosa.

OBJECTIVE: The aim of this study was to investigate the presence of Helicobacter pylori in both dental plaque and gastric mucus. STUDY DESIGN: Dental scaling hand instruments were used to collect supragingival and subgingival dental plaque from 81 dentate participants. Denture plaque was obtained from the fitting surfaces of dentures from 41 edentulous patients. Gastric mucus from gastric mucosa of antrum and body of stomach were collected from all 122 participants (92% white) with soft gastroscopic brush. These samples were dispersed in modified urea broth and normal saline solution before being inoculated onto selective Skirrow's agar and incubated in a microaerophilic atmosphere for culturing H. pylori. RESULTS: Dental plaque from all dentate participants was negative for H. pylori culture. Only one 80-year-old edentulous patient had positive H. pylori culture in both gastric mucus and denture plaque. CONCLUSIONS: Although dental plaque has a mixed flora that may act as a reservoir for gastric reinfection, dental plaque could not be implicated as the major reservoir of H. pylori for gastric reinfection.

Aged↗
PubMed1992

Diagnostic accuracy and observer performance in the diagnosis of abnormalities in the anterior maxilla: a comparison of panoramic with intraoral radiography.

An investigation was undertaken to assess the reliability of radiographic diagnosis of abnormalities of orthodontic significance in the anterior region of the maxilla from intraoral and dental panoramic tomograph (DPT) views. DPT films of 200 patients were scrutinised by two observers on two separate occasions, who also examined intraoral radiographs of the same patients. Sixty-three of these patients were selected because they had previously been diagnosed as presenting with a defined abnormality of orthodontic relevance, such as supernumerary teeth, absent incisors, etc. The remaining cases had been assessed as depicting normal radiographic appearances. Each radiograph was allocated a unique, randomly selected code number as the only means of identification. It was not possible for the observers to match the DPT to the corresponding intraoral films, and this information was only available to the principal investigator (JWF). Both observers were asked to record the presence or otherwise of any abnormalities at each observation of each radiograph, and to record their findings. The overall level of diagnostic accuracy and reproducibility was fairly high, and in general terms the DPT views were as reliable as the intraoral films with regard to the detection of abnormalities; however, there were significant differences between the observers. It was concluded that in many instances supplementary intraoral films would not contribute any additional information compared to the DPT and that selection criteria should be defined for the former.

Chi-Square Distribution↗
PubMed1992

Osler-Weber-Rendu disease: a six generation family.

A Taiwanese family, with at least nine members in six generations has been affected with Osler-Weber-Rendu disease, also known as hereditary hemorrhagic telangiectasia. It is an autosomal dominant familial disease which involves systemic subepithelial fibrovascular dysplasia and manifests with telangiectasia or angiomas of the face, the palms, or the mucosa of the aerodigestive tract (such as the nose, lips, oral cavity, or stomach, etc.). The most common clinical symptom is recurrent epistaxis with/without upper gastrointestinal bleeding which may be resistant to the otolaryngologist's best efforts for control. Repeated bleeding marks the typical course of the disease. Epistaxis from hereditary hemorrhagic telangiectasias often requires a combination of therapeutic approaches. Carbon dioxide laser surgery was highly successful in decreasing postoperative morbidity and epistaxis in the four patients we treated.

Adult↗
PubMed1992

[Evaluation of biological toxicity of livestock fecal deordoring microbial agents].

Eight commercial livestock microbial agents were selected for the evaluation of biological toxicity. The general physical, chemical and microbial analyses of these microbial agents were performed and the acute toxicity of mice, aquatic living organisms and the germinated inhibition of vegetable seeds by these microbial agents were also estimated for the evaluation of biological toxicity. The results have shown that all livestock microbial agents have no pathogenic Salmonella and Staphylococcus aureus been detected. However, the acute biological toxicity test of water extractant of these microbial agents indicated that microbial agent A, B, C, D and M appeared various toxicity to the mice. The dosage of LC50 (48 hr) to the mice was 3 mg/ml for microbial agent A (150 mg/kg mouse, high toxicity), 90 mg/ml for microbial agent B (4.5 g/kg mouse, low-medium toxicity), 92 mg/ml for microbial agent C (4.6 g/kg mouse, low-medium toxicity), 118 mg/ml for microbial agent D (5.9 g/kg mouse, low toxicity) and nontoxicity for microbial agent M, respectively. In addition, the dosage of LC50 to aquatic organisms Daphina similis and Lemna minor, was < 0.01 mg/ml and 0.13 mg/ml for microbial agent A, 1.73 mg/ml and 10 mg/ml for microbial B, 3 mg/ml and > 20 mg/ml for microbial C, 0.56 mg/ml and 14 mg/ml for microbial agent D, respectively. All microbial agents also show various inhibitory effects to the seed germination and root extension of vegetable crops. The study has demonstrated that the biological toxicity of livestock microbial agents was following such order: microbial A > B, C > D > M. The animal has shown more sensitive than plant to the microbial agents.

Animals↗
PubMed1991

The distribution of fungiform papillae and taste buds on the human tongue.

Investigations on monkeys have shown that the application of the acidic dye Ponceau S red or the basic dye Alcian blue to the tongue surface facilitates identification of fungiform papillae and taste buds. Both of these dyes were now used in varying degrees of acidity on fixed and unfixed human cadaveric tongues in an attempt to determine the regional distribution of papillae and buds. Satisfactory staining was obtained with acidic Ponceau S red in 10% formalin and 10% trichloracetic acid (pH 2.5). For six tongues, the number of fungiform papillae ranged from 171 to 253 (mean 195) and these were located predominantly at the tip. Of the fungiform papillae, 67% had no staining of taste bud pores. The average number of visible taste pores on the other fungiform papillae was 3 (range 1-21). The correlation between the number of stained taste pores and underlying taste buds was confirmed using serial histological sections of 90 fungiform papillae. This work has shown that a mean of 193 taste buds are carried on fungiform papillae of the human tongue and that 87% of these are located in the anterior 2 cm.

Adolescent↗
PubMed1991

Cancrum oris-like lesions.

Cancrum oris is predominantly seen in children in underdeveloped countries where widespread malnutrition, dehydration and epidemic infections are present. In the western world, it is sometimes found in immunosuppressed adults with predisposing conditions such as leukaemia and infection associated with malnutrition. Early diagnosis and an intensive therapeutic approach are the key to a favourable prognosis of noma-like necro-ulcerative lesions. The prognosis is significantly improved if the predisposing condition can be removed. Two cases are presented and the treatment is discussed.

Ampicillin↗
PubMed1991

[Blood flow capacity of the vertebra and cervical artery affected by propagated sensation with acupuncture excitation].

The researchers made some improvement of the measure method of head total blood flow capacity. Excitations of propagated sensation were induced in 55 cases of cervical vertebra disease [acupoints: Shousanli (LI 10), Dazhu(UB 11), Shenzhu (Du 12), Houxi (SI 3)], and 66 cases of cerebral ischemia disease caused by insufficiency of vertebra artery blood supply [acupoints: Hegu (LI 14), Quchi (LI 11), Jugu (LI 16), Tianliao (SJ 15)] by acupuncture. The result showed that obvious effect (P less than 0.05-0.01) was found in the group in which propagated sensation reached the affected area, some effect in the propagated sensation group, and little effect in the local sensation group. The result indicated that the method of acupuncture excitation of propagated sensation could relieve vascular and muscle convulsion and ease the degree of vascular tension and obstruction. It could increase the blood flow capacity of cervical and vertebra artery significantly, so that it could play the role of promoting blood circulation to remove blood stasis and improving tissue nutrition and autonomic nerve function. This study showed further that to let acupuncture excited propagated sensation reach the affected area was an important method of promoting clinical effect.

Acupuncture Therapy↗