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Biomedical subjects

H S Yu

Publications and source records attributed to H S Yu.

At least 73 records · Page 4Linked to original sources
PubMed1997

The effect of shovel trait on Carabelli's trait in Taiwan Chinese and Aboriginal populations.

Chinese and other Mongoloid populations differ from Caucasoids by having a high prevalence of shovel trait and a low prevalence of Carabelli's trait. This study was conducted to compare the association between the shovel and the Carabelli's traits between Chinese and aboriginal Mongoloid populations. The research is designed to sample randomly a Chinese population and an aboriginal population having low admixture with neighboring populations. The Mongoloid aboriginal group was from the Bunun tribe who resides in an isolated alpine area in Taiwan. The effects of sex and age on Carabelli's trait were controlled in this study, as was the association between tooth size and Carabelli's trait. Our results show that males had more Carabelli's trait expressed on teeth than females in both of these two Mongoloid populations. The buccolingual diameter of Carabelli's trait teeth was larger than that of teeth without the trait. After controlling for sex, age, and tooth size, the existence of the shovel trait significantly increased the likelihood of having Carabelli's trait, especially in Chinese, which implies another significant ethnic feature for Mongoloid identification.

Adolescent↗
PubMed1997

Cutaneous sarcoidosis. Report of two cases and literature review.

Sarcoidosis is a multi-system granulomatous disorder of unknown cause that presents more frequently in young adults with bilateral hilar adenopathy, pulmonary infiltrates, and skin or eye lesions. The multisystem clinical manifestations of this disease are a diagnostic challenge to all physicians. Although the clinical and pathological characteristics of sarcoidosis are well described, the decision to treat and the optimal therapy are less well defined. We report two patients of systemic sarcoidosis with cutaneous manifestations of the disease. Gallium whole body scintigraphy was performed and showed increased activity over the bilateral pulmonary hilar region (lambda sign), lacrimal and parotid glands (panda sign).

Adult↗
PubMed1997

Peritoneoscintigraphy using Tc-99m MAA for diagnosis of diaphragmatic disruption in a peritoneal dialysis patient.

Massive hydrothorax is an infrequent but well-recognized complication of continuous ambulatory peritoneal dialysis (CAPD), and is often regarded as a contraindication to its use. We describe here a patient with massive hydrothorax that appeared during CAPD. Peritoneoscintigraphy was performed to demonstrate the clinical suspicion of a pleuroperitoneal communication and the pleurodesis using tetracycline was commenced and this allowed the successful continuance of CAPD.

Female↗
PubMed1996

Deterioration of cutaneous microcirculatory status and its clinical correlation in tetralogy of Fallot.

The purpose of this study was to evaluate the hemodynamic deterioration in cutaneous microcirculation and its clinical correlation in patients with tetralogy of Fallot (TF). Laser Doppler flowmetry and capillary microscopy were used to assess thermoregulatory and nutritional microcirculation, respectively. A significant increase in blood flow in thermoregulatory vessels was noticed only in TF patients with hemoglobin (Hb) levels under 19 g/dl. In patients with Hb levels above 19 g/dl, the blood flow declined into the normal range. This result indicated an extreme decrease of blood flow velocity in the thermoregulatory vessels in patients with Hb concentration higher than 19 g/dl. All TF patients with Hb concentrations higher than 19 g/dl revealed Maricq's type III capillaries. Type III capillaries revealed a significant retardation of capillary blood cell velocity (CBV). There was a reciprocal relationship between CBV and hematocrit (Hct). All the responses of the cutaneous microcirculation revealed a good correlation with the clinical severity of TF. All patients with type III capillaries (with Hb concentrations higher than 19 g/dl or Hct level higher than 60%) indicated an advanced disease progression. Laser Doppler flowmetry and capillary microscopy provide a sensitive noninvasive approach for the evaluation of the hemodynamic disturbances in TF and conditions resulting from long-term hypoxia.

Adolescent↗
PubMed1996

Lymphocyte beta2-adrenergic receptors and plasma catecholamine levels in lead-exposed workers.

The effect of lead exposure on beta2-adrenoceptor density and catecholamine response was studied in 26 male workers and 1 female worker, exposed to lead on average for 6 years. The systolic blood pressure in lead workers (101-160 mmHg, 124.4 +/- 14.7 mmHg) was found to be significantly higher than in controls (97-134 mmHg, 115.4 +/- 10.4 mmHg, p < 0.01) as was plasma norepinephrine (0.51 +/- 0.1 microg/liter vs 0.24 +/- 0.05 microg/liter, p < 0.01). The density of lymphocyte beta2-adrenergic receptors (Bmax) in lead-exposed workers was 86% lower than that in controls (0.15 +/- 0.08 vs 1.08 +/- 0.29 fmol/0.1 x 10(6) cells; p < 0.01). The dissociation constants (Kd) of [125I]iodocyanopindolol were 93.6 +/- 42.6 and 87.9 +/- 42.7 pM in lead-exposed workers and controls, respectively. Multiple linear regression analysis showed that elevation of systolic pressure was closely related to (a) blood lead levels, (b) decreased beta2-adrenergic receptor density, and (c) increased plasma catecholamine levels in lead-exposed workers. Linear regression analysis revealed that both plasma norepinephrine levels and beta2-adrenoceptor density (Bmax) were highly correlated with both systolic blood pressures and blood lead levels in lead-exposed workers, and a highly significant negative correlation was found to exist between Bmax and plasma norepinephrine levels (r = -0.82, p < 0.001). These data therefore demonstrate that there is a close relationship between elevated plasma catecholamine levels, decreased beta2-adrenergic receptors, and elevated blood pressure in lead-exposed workers.

Adult↗
PubMed1996

The expression of cytokines by an established basal cell carcinoma cell line (BCC-1/KMC) compared with cultured normal keratinocytes.

A basal cell carcinoma (BCC) cell line (BCC-1/KMC) has recently been successfully established from a patient. The production of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6 and IL-8 was assessed in comparison with that of cultured normal keratinocytes. The mRNA expression of these cytokines was measured by a reverse transcriptase-polymerase chain reaction (RT-PCR) method and the protein production by an ELISA. The cultured BCC cells spontaneously secreted more IL-6 and IL-8 but less IL-1 than the keratinocytes after culture for 24 h at 37 degrees C. It is suggested that the increased expression of IL-6 and IL-8 may indicate the transformation of normal keratinocytes to locally aggressive BCC.

Basal Cell Carcinoma↗
PubMed1996

Effects of acetylcholine and carbachol on bovine corneal endothelial cells in vitro.

PURPOSE: To assess the relative cytotoxicity of Miochol (1% acetylcholine and mannitol), Miostat (0.01% carbachol, sodium, potassium, magnesium, and calcium salts), and their individual components using in vitro models of bovine corneal endothelial cells (BCECs). SETTING: Laboratories of the Departments of Ophthalmology and Physiology, The University of Texas Health Science Center, Houston. METHODS: The study was divided into four experiments. Experiment 1 used a confluent model to compare the relative cytotoxicity of Miochol and Miostat on BCECs following short-term exposure. In Experiments 2, 3, and 4, the proliferation model (preconfluent BCECs) was used to detect the possible cytotoxicity of individual components in the commercial preparations of the miotics; i.e., the preconfluent BCECs were exposed to buffered salt solutions containing mannitol (1%, 3%, and 4%), acetylcholine (0.5%, 1%, and 2%), or carbachol (0.1%, 0.5%, and 1%) for 3 hours. RESULTS: Confluent BCECs exposed to Miochol for 30 minutes underwent necrosis and degeneration, while those treated with Miostat did not show any morphological changes. None of the tested solutions except 2% acetylcholine and 1% carbachol caused observable changes in the nuclear densities of BCECs at 24, 72, 120, and 168 hours. CONCLUSION: The major components of Miochol (acetylcholine and mannitol) were found to be nontoxic; the cytotoxicity of the preparation was possibly due to the lack of an appropriate balanced salt solution. These findings may influence the selection of a miotic for use during intraocular surgery.

Acetylcholine↗
PubMed1996

Analytical studies of spontaneous and vasopressin-induced calcium oscillations in cultured vascular smooth muscle cells.

Spontaneous and vasopressin-induced Ca2+ oscillations in cultured vascular smooth muscle (A7r5) cells were further examined and characterized. Intracellular Ca2+ concentrations ([Ca2+]i) were measured by use of a high-performance laser cytometer. When the oscillatory patterns in [Ca2+]i were analyzed with a power spectrum method, about 80% of cells exhibited spontaneous Ca2+ oscillations with the frequency of 0.02-0.5 Hz. Nifedipine abolished these repetitive spikes, whereas pinacidil partially attenuated their amplitude and frequency. When vasopressin (100 nM) was applied to A7r5 cells, there was an initial rise in [Ca2+]i, followed by a delayed sustained increase in [Ca2+]i. The one-pool, nonoscillatory model was employed to fit this biphasic change, and the difference between the observed response and the simulated response was then analyzed with a power spectral method. About 50% of cells were noted to display oscillatory patterns in [Ca2+]i after sustained increase in [Ca2+]i. The present study indicates that spontaneous Ca2+ oscillations in A7r5 cells are modulated by the activity of ATP-sensitive K+ channels and are not related to pertussis toxin-sensitive GTP-binding protein(s). On the basis of the one-pool, nonoscillatory model, it is suggested that the buffering capacity of internal stores appears to be stronger in the cells with spontaneous Ca2+ oscillations than in those in a quiescent state, and the vasopressin-mediated inhibition of accumulation by internal stores was attenuated when the cells exhibited spontaneous Ca2+ oscillations. The implementation of this minimum kinetic model integrated with a power spectrum method would be an alternative to understand the oscillating behavior in [Ca2+]i.

Adenosine Triphosphate↗
PubMed1996

Low-energy helium-neon laser irradiation stimulates interleukin-1 alpha and interleukin-8 release from cultured human keratinocytes.

Clinical observations have suggested that low-energy lasers might promote wound healing. Evidence suggests that He-Ne laser irradiation induces an increase in the rate of keratinocyte migration and proliferation as compared with nonirradiated controls in vitro. This study sought to determine whether He-Ne laser could induce cytokine production in cultured keratinocytes. The results revealed (i) a significant increase in interleukin-1 alpha and interleukin-8 production and their respective mRNA expression in He-Ne laser-treated groups as compared with nonirradiated controls, and (ii) under 1.5 joules/cm2 irradiation, this stimulating effect of He-Ne laser treatment is concentration-dependent. Because interleukin-1 alpha induces keratinocyte migration, this finding may partially explain the stimulatory effects on the motility of keratinocytes. As both interleukin-1 alpha and interleukin-8 provoke proliferation of keratinocytes, it is not unreasonable to propose that these two cytokines play a profound role in the enhancement of keratinocyte proliferation as a result of He-Ne laser irradiation. Our findings provide further evidence of enhanced wound healing at the cellular and molecular level as a result of the He-Ne laser.

Cells, Cultured↗
PubMed1996

Biochemical and molecular characterization of a strain KA/S2 of Acanthamoeba castellanii isolated from Korean soil.

A strain, KA/S2, isolated from Korean soil and morphologically assigned to Acanthamoeba castellanii, was characterized by isoenzyme analysis, and total proteins profile, and mitochondrial (Mt) DNA restriction fragment length polymorphism (RFLP), and compared with four reference strains assigned to the species (the authenitic Castellani, Neff, Ma, and Chang strains). It was found that four isoenzyme, total proteins, and Mt DNA RFLP patterns by eight restriction endonucleases of the strain KA/S2 were identical with those of the Neff strain, isolated from soil of California, USA. The Chang strain was unique in its morphology and total protein patterns. Interstrain polymorphisms of isoenzyme profiles and Mt DNA RFLP patterns were observed among the Castellani, Neff, Ma, and Chang strains. Mt DNA RFLP was confirmed to be highly appropriate for the strain characterization and identification of Acanthamoeba spp.

Acanthamoeba↗
PubMed1996

Close relatedness of Acanthamoeba pustulosa with Acanthamoeba palestinensis based on isoenzyme profiles and rDNA PCR-RFLP patterns.

The taxonomic validity of morphological group III Acanthamoeba spp. is uncertain. In the present study, six type strains of group III Acanthamoeba spp., A. culbertsoni, A. healyi, A. pustulosa, A. palestinensis, A. royreba and A. lenticulata were subjected for the evaluation of their taxonomic validity by comparison of the isoenzyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP), and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. palestinensis and A. pustulosa showed almost identical patterns of isoenzymes and rDNA PCR RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenzymes and rDNA PCR-RFLP. It is likely that A. pustulosa is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

Acanthamoeba↗
PubMed1996

Fiberglass dermatitis: a case report.

Glass fibers are the most widely distributed mineral fibers because of their multiple applications, chiefly as insulation materials, and have become important in replacing asbestos fibers. Fiberglass dermatitis is one of the most common forms of occupational dermatitis resulting from mechanical irritation. Here we report a typical case. A 30-year-old male worker handled the cutting and grinding of fiberglass mats and then mixed them with resin as reinforcing materials. He complained of intense itching after the first two weeks of employment. Erythematous macules, papules and folliculitis with excoriation developed over his arms, neck, face and upper chest. There were many transparent glass fiber spicules with the diameter around 7-10 microns detected by applying the adhesive tape against the skin lesion, followed by microscopic observation. He was much improved during hospitalization with oral antihistamine and topical steroid ointment. To prevent this occupational disease, we suggest proper procedures of production, storage, transportation and cleaning in the industrial setting and proper protective clothing in personnel to minimize the release of and exposure to glass fibers.

Adult↗
PubMed1996

[The study on the in-vitro stability of Tc(V)-99m dimercaptosuccinic acid].

Tc(V)-99m DMS, developed by Yokoyama et al. in 1981, has been recognized to be advantageous for the scintigraphic diagnosis of various malignant tumors and their metastasis, the aim of this study is to assess the in-vitro stability of Tc(V)-99m DMS. Thin-layer chromatography, including paper chromatography and silica gel thin layer chromatography, is performed to determine the change of radiochemical species presented in the reconstituted solution of Tc(V)-99m DMS prepared from the DMS kit (Institute of Nuclear Energy Research, Atomic Energy Council R.O.C.) and the commercial DMSA kit (Nephroscint, IRE CELLTARG Radiopharmaceuticals Japan). The bioscan imaging scanner is used to measure the Rf value and labeling efficiency of radiochemical species on the chromatographic strip. The in-vitro stability of Tc(V)-99m DMS prepared from the DMS kit and the commercial DMSA kit is studied by examining various parameters which include temperature(degree C) and time(hr) after reconstitution. The results show that the in-vitro stability of Tc(V)-99m DMS prepared from the DMS kit is actually better than that from the commercial DMSA kit. The one-step labeling method of DMS kit is much simpler than the two-step labeling method of DMSA kit.

Drug Stability↗
PubMed1996

The cytotoxic effect of neonatal lupus erythematosus and maternal sera on keratinocyte cultures is complement-dependent and can be augmented by ultraviolet irradiation.

To elucidate the role of autoantibodies and ultraviolet (UV) exposure in the pathogenesis of the skin lesions in neonatal lupus erythematosus (NLE), keratinocytes were cultured, as the target cells, from a patient with NLE and from a normal neonate. We demonstrated that the expression of nuclear/cytoplasmic Ro/SSA and La/SSB molecules on to the surface of NLE keratinocytes occurred to a much greater extent than that on normal keratinocytes. A dose of 200 mJ/cm2 UVB irradiation on NLE keratinocytes induced a 2.5-3-fold increase in Ro/SSA and La/SSB expression compared to non-irradiated cells. Sera derived from both the NLE patient and from his mother exhibited a cytotoxic effect on NLE keratinocytes, but not on control cells, in the presence of complement. Furthermore, the cytotoxicity of the sera was enhanced on UVB-irradiated NLE keratinocytes, whereas it had no cytotoxic effects on UVB-irradiated control cells. This suggests that the abnormal expression of both Ro/SSA and La/SSB on the surface membrane of NLE keratinocytes induces the autoantibodies and complements to injure the cells. This complement-mediated cytotoxic effect can be augmented by UV irradiation, a concept not incompatible with the exacerbation of the skin eruption in sun-exposed skin sites.

Antigens, Surface↗
PubMed1995

Intra- and interethnic variability in reduced haloperidol to haloperidol ratios.

Steady-state haloperidol and reduced haloperidol concentrations were measured in 250 schizophrenic patients from 4 ethnic groups: 39 Blacks, 66 Caucasians, 82 Chinese, and 63 Mexican Americans. The distribution of the reduced haloperidol to haloperidol concentration (RH/HL) ratios was bimodal in all ethnic groups, with the antimode determined by probit plot as 0.46, 0.51, 0.36, and 0.76, respectively. With these antimodes, the proportion of patients with low RH/HL ratios were 41%, 42%, 73%, and 57% in the four ethnic groups, respectively. Compared with the other three ethnic groups, in the Chinese patients the ratio was lower. The mean RH/HL ratio in the Chinese was 0.34 compared with 0.81 to 0.87 in the non-Chinese groups. In 53 patients who were treated with two or more haloperidol dosage regimens, steady-state haloperidol and reduced haloperidol drug concentrations obtained from the different regimens were positively correlated with the haloperidol dose (R = .79 and R = .62, respectively). Our data suggest not only the existence of a bimodal distribution in the RH/HL ratio, but also that the antimode separating the low and high ratio subgroups is different among the various ethnic groups.

Adult↗
PubMed1995

Multiple risk factors associated with arsenic-induced skin cancer: effects of chronic liver disease and malnutritional status.

In order to evaluate the prevalence and multiple risk factors of arsenic-induced skin cancer among residents in Taiwanese villages in which chronic arseniasis is hyperendemic, a total of 1571 subjects aged 30 or more years were recruited between September 1988 and March 1989. All of them were interviewed personally by a public health nurse using a structured questionnaire, and 1081 interviewed study subjects, including 468 men and 613 women, participated in physical examination, giving a participation rate of 68.8%. The overall prevalence of skin cancer was as high as 6.1%, showing an increase with age in both men and women. There was a significant dose-response relation between skin cancer prevalence and chronic arsenic exposure as indexed by duration of residence in the endemic area, duration of consumption of high-arsenic artesian well water, average arsenic exposure in parts per million (p.p.m.) and cumulative arsenic exposure in p.p.m.-years. Chronic carriers of hepatitis B surface antigen with liver dysfunction had an increased prevalence of skin cancer. Undernourishment, indexed by a high consumption of dried sweet potato as a staple food, was also significantly associated with an increased prevalence of arsenic-induced skin cancer. All these risk factors remained statistically significant in the multiple logistic regression analysis. Consistent with animal experiments, the findings imply that liver function and nutritional status may affect the metabolism of inorganic arsenic and the development of subsequent skin cancers.

Adult↗