Biomedical subjects

H S Yu

Publications and source records attributed to H S Yu.

At least 109 records · Page 6Linked to original sources

PubMed1993

Study on blackfoot disease: with special reference to evaluating its cutaneous microcirculatory status.

We evaluated the microcirculatory status of blackfoot disease by skin temperature measurement, laser Doppler flowmetry and capillary microscopy. The results of these assessments revealed a good correlation between the disease stage and the microcirculatory status. No effective therapy other than surgical amputation was recommended before. In this study, we treated this endemic disease with prostaglandin E1 (PGE1) infusion therapy. PGE1 was most effective in the erythematous stage and some minor ulcer with an improvement of microcirculatory status. However, PGE1 had no effect in severe ulcerative (ulcer > 0.5 cm) and gangrenous stages. These microcirculatory improvements foreshadowed the improvement of clinical manifestations. The microcirculatory status after PGE1 treatment demonstrated the effectiveness of the therapy.

Aged↗

PubMed1993

Three-dimensional ultrastructure of generative cell mitosis in the pollen tube of Nicotiana tabacum.

Generative cell mitosis was examined in stylar-grown pollen tubes of Nicotiana tabacum using serial sectioning, transmission electron microscopy and computer-assisted reconstruction. Before mitosis, the generative cell has a cage-like organization of cytoplasmic microtubules. The mitotic spindle forms when the cytoplasmic microtubules reduce in frequency and kinetochore microtubules form in an area delimited by sheets of endoplasmic reticulum; no preprophase band of microtubules is observed. At metaphase, 21 pairs of kinetochores are distributed unevenly along the length and depth of the cell without the formation of a strictly planar metaphase plate. The metaphase spindle is highly oblique, with diffuse subpoles distributed along the sides of the cell, colocalized with endoplasmic reticulum lamellae. From these dispersed subpoles the kinetochore bundles emanate, closely associated with tubular endoplasmic reticulum. Anaphase consists of three principal processes: convergence of diffused mitotic poles, shortening of the kinetochore bundles, and the elongation of the spindle by an average of nearly 50%. At mid-anaphase, a phragmoplast begins to form, mainly by the assembly of new microtubules at the equatorial area, which form as a cluster of numerous short microtubules. Cytokinesis is essentially conventional, with centrifugal cell plate formation. Cytoplasmic microtubules are restored in the newly formed "brother" sperm cells in a distribution similar to that in the generative cell but fewer in number.

Endoplasmic Reticulum↗

PubMed1993

The gastro-intestinal absorption of griseofulvin can be enhanced by encapsulation into liposomes.

Liposomes are microscopic structures consisting of one or more lipid bilayers enclosing a definite aqueous space. They are widely used as a drug carrier and for the delivery of drugs through membranes. Drugs can be encapsulated into the inner water phase or lipidic wall, depending on their own hydro- or lipophilicity. The characteristics of the vesicles is fusion with cells and natural endocytosis uptake. We applied the properties of liposomes to overcome the poor gastro-intestinal (GI) absorption of griseofulvin and compared results with the traditional dosage form. In this experiment, the maximum plasma concentration obtained from griseofulvin liposomes was about 2.6 times than that from griseofulvin suspension. We used the lipids to prepare liposomes that consisted of phosphatidycholine, cholesterol, and dicetylphosphate in the molar ratio, 1:1.6:0.2, which is similar to the membrane composition of red blood cells. We examined some factors affecting the encapsulation ratin (E.R.%) and physicochemical properties of liposomes. When the lipid-to-griseofulvin weight ratio approached 38:1, the encapsulation ratio reached 94%. The different lipid/aqueous ratio (19/1 48/1 96/1) appeared to have little effect on E.R. value. The stability of griseofulvin liposomes in terms of leakage of griseofulvin was negligible over a period of 18 days at 4 degrees C. The sedimentation of vesicles bearing negative charges exhibited the best flocculation state. The plasma level-time profile of griseofulvin obtained from ingestion of liposomal dosage form showed itself to be significantly higher (P<0.01) Cmax, AUC, Ka, and t1/2 than that from suspension.

Absorption↗

PubMed1992

Levels of plasma lipid peroxides before and after choledocholithotomy in patients with obstructive jaundice.

Plasma lipid peroxide levels were measured in a group of 40 healthy controls and 11 patients with jaundice. In the case of these 11 patients, we checked the plasma lipid peroxide concentrations prior to and after choledocholithotomy. Before choledocholithotomy, there were significantly higher mean concentrations of plasma lipid peroxides and bilirubin in patients with jaundice than in the control cases (11.8 +/- 2.3 vs. 2.0 +/- 0.1 nmol/ml and 10.3 +/- 1.82 vs. 0.7 +/- 0.03 mg/dl, respectively, P < 0.05). In addition, patients with jaundice had lower plasma vitamin E levels in comparison to the controls (8.2 +/- 0.6 vs. 12.2 +/- 0.5 micrograms/ml, P < 0.05). In patients with jaundice, the increased plasma lipid peroxides were clearly related to the serum levels of bilirubin (r = 0.87, P < 0.05). After surgery, the higher plasma levels of lipid peroxide and bilirubin were reduced markedly (11.8 +/- 2.3 vs. 3.7 +/- 0.4 nmol/ml and 10.3 +/- 1.82 vs. 3.1 +/- 0.47 mg/dl, respectively, P < 0.05) with the restoration of bile flow which was associated with improvement in liver function tests. Consequently, these results suggest that there is an involvement of lipid peroxidation in liver cells damaged by obstructive jaundice in patients with cholelithiasis, and that these high plasma lipid peroxide levels may correlate with the severity of the disease.

Adult↗

PubMed1992

Comparison of the effect of 8-methoxypsoralen (8-MOP) plus UVA (PUVA) on human melanocytes in vitiligo vulgaris and in vitro.

In this study, we examined the various effects of PUVA treatment on cultured human melanocytes, and it revealed that 1) the higher the dose of PUVA treatment, the more significant the inhibition of cell DNA and protein synthesis; 2) the higher the dose of PUVA treatment, the more significant the depletion of epidermal growth factor receptor (EGFR) expression; 3) PUVA treatment at 124 mJoule/cm2 depleted the vitiligo-associated melanocyte antigens (VAMA) immediately after irradiation, and both the VAMA and EGFR expression progressively recovered at 24 or 72 h after PUVA; 4) PUVA treatment stimulated tyrosinase activity, but not in a dose-dependent fashion. In vitiligo vulgaris, PUVA treatment may stimulate the regrowth of melanocytes from hair follicles, but deplete the epidermal Langerhans cells in depigmented lesion of patients with stable vitiligo. Comparing the above results obtained from in vivo and in vitro studies, it reveals significantly different biologic responses. Although the precise therapeutic mechanism of PUVA treatment in vitiligo is still not well known, it is proposed that 1) PUVA treatment may stimulate the other components of skin, such as keratinocytes, to release inflammatory mediators and some of them may act as melanocyte growth-stimulatory factors (MGSF), which further enhance the proliferation of remaining melanocytes in hair follicle; and 2) PUVA treatment may deplete the VAMA expression on cell membrane of melanocytes and also deplete epidermal Langerhans cells, which may result in blocking the progressing of antibody-dependent cell-mediated cytotoxicity to melanocytes in vitiligo.

Adult↗

PubMed1992

Characterization of an immortalized human cell line derived from neonatal foreskin diploid fibroblasts.

A new human skin cell line, designated as CCFS-1/KMC, immortalized from human neonatal foreskin diploid fibroblast cells, has been subcultured successfully in vitro for more than 500 passages. This anchorage-dependent cell line possesses many common features of transformation such as morphological and cytoskeletal changes, hypotriploidy, infinite lifespan, increasing plating efficiency and saturation density, and decreasing serum requirement and population doubling time. Human papillomavirus (HPV) type 18 DNA was detected in the cell line before and after immortalization by the polymerase chain reaction (PCR) method. Tumorigenicity, however, was not demonstrated in vivo. The isoenzyme activity of the cell line shows activation of a placental form of alkaline phosphatase and a changing lactate dehydrogenase isoenzyme pattern that is different from transformation by carcinogens. Class I HLA and class II HLA antigens are constitutively expressed on this skin cell line. Here we report that these immortalized human fibroblasts derived from neonatal HPV-18-DNA-contained diploid fibroblasts possess double minute chromosomes (DMs), a karyotypic aberration usually found in cancer cells.

Cell Division↗

PubMed1992

Alterations of mitogenic responses of mononuclear cells by arsenic in arsenical skin cancers.

We have studied the endemic occurrence of chronic arsenism in a limited area on the southwest coast of Taiwan. The effects of arsenic on the mitogenic responses of mononuclear cells (MNC) derived from patients with arsenical skin cancers in that area were evaluated. The subjects enrolled in this study included patients with 1) Bowen's disease, 2) arsenical skin cancers (basal cell carcinoma and squamous cell carcinoma), 3) non-arsenical skin cancers (basal cell carcinoma and squamous cell carcinoma), 4) nasopharyngeal cancer and 5) healthy controls from endemic and non-endemic areas. Phytohemagglutinin (PHA) stimulated [3H]thymidine incorporation in MNC in all groups except the arsenical skin cancer group. However, when a low concentration of As2O3 (2.5 x 10(-7) M) was added to PHA-stimulated MNC, a tremendous amplification of the uptake of [3H]thymidine was noticed in patients with arsenical skin cancer. In this study, this phenomenon did not occur in cancers not related to arsenic. This result shows that arsenical carcinomas are hyperreactive to its specific etiology--arsenic. Arsenic seems to play a role as a co-stimulant of PHA similar to interleukin-1.

Arsenic↗

PubMed1992

[Clinical and scanning electron microscopic studies on Norwegian scabies infection].

Two typical cases of Norwegian scabies were studied clinically, scanning electron microscopically and histopathologically. Case 1 was a boy with Down's syndrome and case 2 was a man with adult T cell leukemia/lymphoma. Their clinical pictures showed hyperkeratotic plaques and warty crusts on hands, feet, ears, elbows and buttocks. Direct examination of the KOH preparation revealed many embryonated sarcoptic eggs, postpartum egg-shells, fecal pellets, larvae and male and female adult mites. Histopathologic examination showed several burrows inside the thick horny layer. Many sarcoptic egg-shells, mites and fecal pellets were found in the burrows. Psoriasiform hyperplasia and parakeratosis were noted, too. The size and shape of the sarcoptic eggs and the detailed structure of mites and molt were observed by using a scanning electron microscope. Besides, hook-like structures were noted at the tarsi of both forelegs and hindlegs. We suggest that the larvae crawl out from longitudinal openings in the egg-shell by the use of hook-like structures. The mites also used these hook-like structures to make the burrows. Scanning electron microscopy provides a good method to understand the dynamics of these burrowing parasites. It is helpful in illustrating the behavior of the scabies mites in their burrows in Norwegian scabies patients.

Adolescent↗

PubMed1992

Alterations of skin-associated lymphoid tissue in the carcinogenesis of arsenical skin cancer.

We investigated the skin-associated lymphoid tissue in arsenical skin cancers, including 14 Bowen's disease, 6 basal cell carcinoma and 6 squamous cell carcinoma patients from an endemic area by immunohistochemical and morphometric methods. There was a progressive decrease of Langerhans cells in the order of normal skin, normal appearing edge and arsenical cancers. A disruption of the uniform Langerhans cell dendrites was also noticed. The Langerhans cell density in arsenical tumors did not correlate with the peritumoral infiltrates. The prominent infiltrated cells in the peritumoral area had T cell markers. The number of peritumoral T lymphocytes in squamous cell carcinoma was significantly less than that of Bowen's disease and basal cell carcinoma. Peritumoral mononuclear infiltrates in Bowen's disease and squamous cell carcinoma showed a higher helper/suppressor T cell ratio than that in basal cell carcinoma. This may be accounted for by a selective increased recruitment of helper T cells to the tumor infiltrates in Bowen's disease and squamous cell carcinoma.

Arsenic Poisoning↗

PubMed1992

Effects of flurbiprofen and suprofen on the miotic activity of 1% acetylcholine and 0.01% carbachol.

The nonsteroidal antiinflammatory agents (NSAIAs) flurbiprofen and suprofen applied topically to reduce miosis may counteract the desired effects of miotics used during ocular surgery. In a pigmented rabbit model, 1% acetylcholine was shown to cause a greater, significant initial (for the first 30 minutes) constriction (P less than .05) than 0.01% carbachol in eyes pretreated with flurbiprofen and suprofen. From 2 to 8 hours, NSAIA pretreatment had a greater miotic effect with carbachol than with acetylcholine. There were no significant differences between flurbiprofen and suprofen on the miotic effect of carbachol or acetylcholine.

Acetylcholine↗

PubMed1991

Effects of temperature on cutaneous microcirculation in vibration syndrome.

In order to clarify the role of cold on the cutaneous microcirculation in vibration syndrome, groups of rabbits vibrated at 4 degrees and room temperature served as the subjects of this study. A cold provocation test, capillary microscopy, and laser-Doppler flowmetry were used to evaluate the microcirculations of the test rabbits. The results indicated that vibration-induced impairment of the microcirculation was more prominent in the 4 degrees vibration group than in the room temperature group. The severities of the microcirculatory disturbances were dose-effect correlated. Vibration induced not only functional disturbances but also structural destruction of the capillaries. Furthermore cold temperatures enhanced these abnormalities of the blood vessels.

Animals↗

PubMed1991

Modulation of epidermal terminal differentiation in patients after long-term topical corticosteroids.

The expression of the various markers for terminal epidermal differentiation in atrophic skin of patients after long-term topical corticosteroids (TCS) was studied by electron microscopy, immunofluorescence using antibody to profilaggrin/filaggrin (PF/FG), immunoperoxidase staining using antibody to involucrin, and oil red O stain for neural lipids of the stratum corneum. Thirty-nine patients were subdivided into two groups: (A) 19 patients suffering from rebound phenomenon after stopping TCS and (B) 20 patients without rebound phenomenon. Biopsy specimens were taken before ending the use of TCS in both groups. In group A, both the morphological markers (including the different epidermal strata, keratohyalin granules, lamellar granules, and cornified cell envelopes) and the molecular markers (including involucrin, PF/FG, and neutral lipids) of terminal epidermal differentiation were significantly suppressed. On the other hand, the differentiational markers in the atrophic skin of patients without rebound phenomena were only slightly altered. These results suggest that potent TCS not only has antiproliferative actions but also inhibits the differentiation of epidermis, resulting in structural defects in the epidermis, especially the stratum corneum.

Administration, Topical↗

PubMed1991

Mast cell degranulation and elastolysis in the early stage of striae distensae.

The lesions of nine patients with early striae distensae (SD) during puberty were examined by light and electron microscopy. Specific changes were seen in very early stage SD, and in clinically uninvolved skin 0.5 to 3 cm remote from the edge of the long axis of the SD lesions. Sequential changes of elastolysis accompanied by mast cell degranulation appeared first, followed by an influx of activated macrophages that enveloped fragmented elastic fibers. The relationships among elastic fibers, mast cells, and macrophages seen in the present work suggest their critical roles in the process of SD formation, especially in the early stage. Our results also indicate that the elastic fiber is the primary target of the pathological process, and the abnormalities extend as far as 3 cm beyond the lesion into normal skin.

Adolescent↗

PubMed1991

A survival study of surgically treated lung cancer in Korea. Lung Cancer Surgical Study Group.

Survival rate over a 5-year period were studied in a series of 658 proven primary lung cancer patients treated by thoracic surgeons at 8 institutes during the period from 1976 to 1987 in Korea. The study was designed as a multi-center cooperative work for the statistical analysis of the followup result. Clinical data of age, sex, morbidity, and staging of the tumor were assessed in 540 patients to evaluate their 5-year survival rates. Eventually, 405 resectable patients were analyzed by stage, cell type, surgical procedure, and TNM status. The 5-year actuarial survival rates by stage in the resectable group were: stage I 39.7%, II 30.6% III A 16.3%, III B 6.7%, and IV 0%. The 5-year survival rates by cell type were: squamous cell 31.9%, adenocarcinoma 21.2%, large cell 11%, and small cell 6%. The survival rates by surgical procedures were: lobectomy 30.7% and pneumonectomy 25.7%. The survival rates by TNM status in the operable group were: T1 34.7%, T2 26.8%, T3 7.5%, T4 5%; N1 23%, N2 10%, N3 3%; MO 21%, and M1 0%, respectively. The overall actuarial 5-year survival rate in the group of 405 resectable patients was 25.9%.

Adult↗

PubMed1991

Cutaneous neonatal neuroblastoma: report of a case.

We herein report a case of neonatal neuroblastoma with cutaneous metastasis. This newborn male was a full-term infant of a G3P3 mother. Asphyxia occurred immediately after birth, though he was revived after intensive medical treatment. Physical examination revealed multiple firm cutaneous nodules distributed over his body. In addition, congenital glaucoma, hepatomegaly, and a soft tissue mass along the right temporal bone were also observed. Laboratory data revealed markedly elevated urinary vanilmandelic acid excretion, leukopenia, thrombocytopenia and an increased level of SGOT and SGPT. A skin biopsy was performed on a cutaneous nodule on the right hip, and the histopathological picture confirmed the diagnosis of neuroblastoma. The patient expired 12 days after birth due to complications caused by his condition.

Humans↗

PubMed1991

Dyschromatosis universalis hereditaria: report of a case.

The case of a 43-old-year woman who had a generalized asymptomatic pigmentary disorder with onset at about age 20 is presented. Tracing back her family history, we found that her father and six of her siblings had also suffered a similar skin pigmentary defect with onset at the same approximate age. In depigmented lesions, three distinct histopathological features were observed: (1) decreased epidermal melanin content and lower density of melanocytes in the upper dermis; and (3) ultrastructural vacuolar degeneration in the focal melanocytes and in the keratinocytes immediately nearby. No deposit of amyloid was observed in the biopsied skin specimens. In hyperpigmented lesions, the histopathological features included: (1) increased melanin content and high density of melanocytes; (2) few melanophages in the papillary dermis of focal areas, but no vacuolar degeneration of the epidermal cells; and (3) an increased number of melanosomes in the basal and suprabasal keratinocytes. Direct immunofluorescence examination revealed no deposit of immunoglobulins in either the hyperpigmented or depigmented lesions. By indirect immunofluorescence examination, the serum of the patient was found to contain antinuclear antibodies (ANA, IgG, class, homogeneous pattern); however, the maximal positive dilution titer of sera against cultured human cells was much higher in melanocytes (1:500 dilution) than in keratinocytes (1:50 dilution) or fibroblasts (1:10 dilution). The pathogenesis of dyschormatosis universalis hereditaria remains unclear; however, hereditary genetic defects may play an important role in alternating regular melanogenesis, which results in a pigmentary anomaly.

Adult↗

PubMed1991

[Necrolytic migratory erythema as the first manifestation of glucagonoma].

A 49-year-old woman suffered from recurrent episodes of necrolytic migratory erythema over the lower legs, lower abdomen, and buttocks for more than two years. Stomatitis, glossitis and vaginitis were the accompanying symptoms and signs during each episode. The result of skin biopsy revealed superficial necrosis in the upper half of the epidermis. Laboratory examinations revealed mild glucose intolerance and hypoaminoacidemia. Fasting plasma glucagon level measured by radioimmunoassay was 890 pg/mL. Oral glucose loading test showed a paradoxical increase in plasma glucagon level up to 1,500 pg/mL. Abdominal echo, computerized axial tomography, and celiac angiography demonstrated a hypervascular tumor, 4 cm in diameters, located at the pancreatic head. Glucagonoma syndrome was confirmed and diagnosed. The patient underwent surgical resection of the tumor mass. Necrolytic migratory erythema disappeared thereafter, and the plasma glucagon level declined to 120 pg/mL. Histologically, the tumor revealed an islet cell carcinoma composed of moderately uniform cells with a few mitosis, arranged in cords and nests. Abundant characteristic secretory granules of the pancreatic A cell were found within the tumor cells by electron microscopic examination.

Erythema↗

PubMed1991

[Expression of keratin 16 in normal and lesional skin of solitary and multiple Bowen's disease using monoclonal antibody Ks 8.12 staining].

Bowen's disease is an intraepidermal squamous cell carcinoma usually consisting of a solitary lesion. However, multiple Bowen's lesions are one of the characteristics of arsenicalism in endemic areas where people drink deep well water containing high concentrations of arsenic along the southwest coast of Taiwan. This work seeks to clarify the differences between multiple Bowen's disease in the blackfoot disease endemic area, and solitary Bowen's disease in a non-endemic area by means of Ks 8.12 monoclonal cytokeratin antibody staining. Ks 8.12 may be regarded as a specific antibody for Keratin 16 in the skin and is used as a marker for hyperproliferation. Our results show that Ks 8.12 staining of normal skin in patients with a solitary Bowen's lesion is patchy and always restricted to the basal cell layer. By contrast, the normal skin of patients with multiple Bowen's lesions shows diffuse Ks 8.12 staining of the basal cell layer and various degrees of staining of the suprabasal layers. Similar results were observed in both solitary and multiple Bowen's lesions showing diffuse Ks 8.12 staining of the epidermis. Our results revealed clear differences in keratin expression between the clinically normal skin of patients with solitary Bowen's disease and that of patients with chronic arsenicalism. Finally the clinically normal skin of patients with multipole Bowen's disease showed characteristic changes in the expression of Keratin 16 in the suprabasal layers.

Aged↗