Human skin barrier formation takes place via a cubic to lamellar lipid phase transition as analyzed by cryo-electron microscopy and EM-simulation.

The skin's permeability barrier consists of stacked lipid sheets of splayed ceramides, cholesterol and free fatty acids, positioned intercellularly in the stratum corneum. We report here on the early stage of skin barrier formation taking place inside the tubuloreticular system in the secretory cells of the topmost viable epidermis and in the intercellular space between viable epidermis and stratum corneum. The barrier formation process was analysed in situ in its near-native state, using cryo-EM combined with molecular dynamics modeling and EM simulation. Stacks of lamellae appear towards the periphery of the tubuloreticular system and they are closely associated with granular regions. Only models based on a bicontinuous cubic phase organization proved compatible with the granular cryo-EM patterns. Only models based on a dehydrated lamellar phase organization agreed with the lamellar cryo-EM patterns. The data support that human skin barrier formation takes place via a cubic to lamellar lipid phase transition.

Facial expression under stiff stratum corneum leads to strain concentrations, followed by residual wrinkle formation.

OBJECTIVE: Computer simulation studies of skin models, which indicate skin compression in the same manner as facial expressions, have suggested that stratum corneum could control skin-folding patterns, which may play an essential role in wrinkle formation. However, it is not clear to what extent the mechanics of stratum corneum influence wrinkle formation in vivo. The aim of this study was to verify that stratum corneum could control strain distribution during facial expressions, which in turn leads to wrinkle formation. METHODS: In experiments in vivo, volunteers were instructed to smile under 10% or 80% relative humidity (dry or humid conditions, respectively). Skin movement around their eye corners during smiling was captured by a high-speed video camera. Particle-tracking velocimetry was applied to video recordings to analyse skin strain distribution. Also, wrinkle volumes before or after smiling were measured using replicas. RESULTS: With smiling under dry conditions, high strain was localized to form crease-shaped wrinkles whereas, under humid conditions, localized strain was dispersed. Furthermore, increased wrinkle volume after smiling was promoted under dry conditions. CONCLUSION: Because exposure to dry or humid conditions in the short term could affect only stratum corneum mechanics, the present results indicated that stratum corneum could be considered to be responsible for localized strain during facial expressions. This strain is followed by residual wrinkle formation. Accumulation of residual wrinkles will produce permanent wrinkles in the long term. Improving the mechanics of stratum corneum might be an effective approach in wrinkle formation prevention.

Microrelief suppresses large wrinkling appearance: an in silico study.

BACKGROUND AND PURPOSE: Extensive skin wrinkling during facial expressions is one of the considerable problems in aesthetic dermatology. Although a few in silico studies have been performed with the aim of revealing the mechanism of a wrinkled appearance, there have been few studies that take into account the influence of skin roughness (i.e. microrelief), which exists on human skin in vivo. In this study, finite element simulations were performed using multilayer skin models with microrelief to investigate how extensive wrinkling appears on human skin, especially focusing on the role of surface roughness in the wrinkling mechanism. METHODS: Linear and post-buckling analyses were performed on soft elastic laminate models using the finite element method. A simplified multilayer model of human skin was employed to examine the contribution of skin's multilayer structure to the large-wrinkle mechanism. Microrelief was included in the model to assess its effect on the mechanism. RESULTS: A large wrinkle was observed as dermal buckling following a number of buckling events on the stratum corneum. The existence of microrelief had an effect on the suppression of dermal buckling. CONCLUSION: Skin's multilayer structure should play a major role in the appearance of large wrinkles on human skin via its post-buckling behavior. This study suggested that fine microrelief on the skin surface hampers large wrinkles. These findings should be valuable for the development of cosmetic or medical treatments to prevent unfavorable skin deformations.

Protein carbonyls damage the water-holding capacity of the stratum corneum.

BACKGROUND: Acrolein is a degradation product of lipid peroxide as well as a well-known environmental pollutant. As a hallmark of oxidatively damaged protein, protein carbonyl, including acrolein-protein adduct, has been observed in the skin. However, the influence of protein carbonylation on the stratum corneum (SC) has not yet been clarified. OBJECTIVES: We explored the influence of oxidative protein modification, focusing on the major function of the SC, the water-holding capacity, by introducing experimental protein carbonylation. METHODS: The level of carbonyls in the SC was evaluated by reaction with a labeled hydrazide. The water-holding capacities of the SC or keratin gels were evaluated by measurement of the surface conductance. The bound water (nonfreezing water) content in the SC was measured by the heat of fusion of frozen SC. RESULTS: Acrolein caused protein carbonylation, decreased the water-holding capacity and the bound water of the porcine SC in vitro. The water-holding capacity of the keratin gels prepared from human SC was also decreased by acrolein in vitro. Water content in the human SC in vivo was decreased by sodium hypochlorite and accompanied by the increase in carbonyls. CONCLUSION: Exposure of SC to the oxidative environment damages the water-holding capacity of the SC through the modification of protein-water interaction.

Increased carbonyl protein levels in the stratum corneum of the face during winter.

The stratum corneum (SC) is the interface between the body and the environment, and is continuously exposed to oxidative stress that results in carbonyl modification of proteins. We previously developed a simple and non-invasive method to assess the stratum corneum carbonyl protein (SCCP) levels. In this study, we used this method to examine the seasonal changes in the SCCP levels and the relationship between the SCCP level and the physiological condition of the SC. SC was collected from the face of healthy Japanese volunteers by adhesive tape stripping and its carbonyl groups were determined by reaction with fluorescein-5-thiosemicarbazide. The average fluorescence intensity of the SC was calculated as the SCCP level. The SCCP level in the cheek was higher in winter than summer. The SCCP level was negatively correlated with the water content in the SC measured by the conductance and capacitance, and also negatively correlated with the extensibility of the skin measured by a Cutometer, suggesting that the mechanical properties of the skin can be affected by oxidative modification of the SC. These data suggest the involvement of oxidative modification of SC proteins in the generation of rough skin during winter.

Change in optical properties of stratum corneum induced by protein carbonylation in vitro.

The skin is the frontier against the external environment and continuously exposed to the environmental oxidative stress such as ultraviolet (UV) irradiation. Protein carbonyls are the major oxidative products of protein and may be introduced by reaction with aldehydes derived from lipid peroxide. Acrolein is one of the most reactive aldehydes generated during degradation of lipid peroxides and protein-acrolein adducts have been found in the oxidatively damaged lesion including UV-damaged skin. Recent studies revealed that protein carbonyls are also detected in thin outermost layer of the skin, the stratum corneum (SC). However, the effect of protein carbonylation on the function of SC was still unclear. In this study, we treated the SC sheets of reconstructed human epidermis and porcine epidermis with acrolein in the experimental conditions to explore the influence of protein carbonylation on the SC. Human and porcine SC sheets treated with acrolein showed less transmission at visible light than untreated SC sheets. Attenuated total reflection-infrared spectroscopy with curve fitting analysis of amide I region showed that acrolein induced alterations in protein secondary structure of the porcine SC sheets, which were accompanied by diminished fibrous keratin structure observed by transmission electron microscopy. These results show the possibility that carbonylation of the SC caused by environmental factors is one of factors altering the fibrous structure of keratin and decreasing the light transmission of SC, which changes the quality of the skin appearance.

UVA-induced immune suppression through an oxidative pathway.

Although ultraviolet B (UVB) irradiation induces local immune or systemic immune suppression, depending on the dose, the immune suppression by ultraviolet A (UVA) has not been fully investigated. In this study, we investigated the effect of UVA on the immune response in vitro and in vivo. The effect of UVA on the antigen-presenting function of epidermal cells was measured in terms of antigen-specific T cell proliferation. A murine epidermal cell suspension was exposed to UVA in vitro, pulsed with trinitrobenzenesulfonic acid, and cultured with T cells prepared from syngeneic mice previously sensitized with trinitrochlorobenzene. UVA (5-20 J per cm2) suppressed the antigen-presenting function of epidermal cells in a dose-dependent manner, accompanied with suppression of the expression of costimulatory molecules on Langerhans cells. In order to investigate the effect of an antioxidant on the immune suppression, an epidermal cell suspension was irradiated with UVA in the presence or absence of glutathione. The suppressions of antigen-presenting function and ICAM-1 expression were significantly prevented by glutathione in a dose-dependent manner. Further, the effect of UVA on the immune response at the induction phase of contact hypersensitivity was evaluated in terms of lymph node cell proliferation ex vivo. UVA irradiation suppressed the endogenous proliferation of lymph node cells in trinitrochlorobenzene-painted mice, and this suppression was significantly reversed by the application of glutathione to the skin during irradiation. These results suggest that UVA-induced immune suppression may be mediated by reactive oxygen species, at least in part.

In vitro and in vivo prolonged biological activities of novel vitamin C derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), in cosmetic fields.

The biological activity of the novel vitamin C derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), was evaluated in vitro and in vivo. The percutaneous absorption of AA-2G was determined in five Japanese males. The excretion of ascorbic acid (AA) in the subjects administered AA-2G was sustained for a longer period than in the subjects administered ascorbic acid 2-phosphate (AA-2P), which is a conventional vitamin C derivative. An analysis of the distribution of AA in the skin showed that small black specks assumed to be AA were observed in the epidermis even 3 d after applying AA-2G. The melanin synthesis in B16 melanoma cells was inhibited more by AA-2G than by AA-2P, and AA-2G also prevented more UV-induced damage of human skin keratinocytes and fibroblasts than AA-2P did. From these in vivo and in vitro results, it is supposed that the conversion of AA-2G to AA is sustained for a long time compared with that of AA-2P, and that AA-2G is an effective and available compound having vitamin C activity in human subjects.

[Analysis of the concept of care/caring-structure of attributes identified from qualitative and quantitative research].

The concept of care/caring has been recognized as the central component of nursing in the United States of America since the 1980s. Although caring is the essence and the central focus of clinical nursing, the term has several meanings, and there is no consensus regarding its definition. The concept of care/caring should be examined not only from the nurse's perspective, but also from the patient's perspective. The purpose of this research is to identify the common characteristics of the concept of care/caring from both the patient's and nurse's perspectives, and to clarify the structure of the concept of care/caring in the English articles. Thirty qualitative research papers written by 21 authors and 17 quantitative research papers written by 9 authors were sampled. From the analysis of the 47 articles, 5 categories and 13 sub-categories were identified as attributes of care/caring. The 5 categories were 1) Characteristics of Nurse, 2) Nursing Activities, 3) Patient-Nurse Relationship, 4) Caring Outcomes, and 5) Others. As the next stage of the research, the concept of care/caring in Japanese nursing should be analyzed. It must be determined whether the concept of care/caring is also the central component of nursing in Japan and if so can these identified characteristics of the concept be applied to the concept of care/caring in Japanese nursing.

[St. Luke's College of Nursing: student's motivation for selecting both nursing program and St. Luke's College for study].

In 1989, we published "A Study of Students' Motivation for Selecting a Nursing Program". Now, as the circumstances surrounding nursing education and the social situation are changing, we studied this matter again. The purpose of this survey is a) to find the motive for selecting a nursing program as well as this college, and b) to compare the results with those of the previous study. The questionnaire delineating reasons for selecting a nursing program and St. Luke's College were distributed to the 392 students who entered this college from 1989 to 1995. The response rate was 93.9%. The findings were as follows: 1) Many students selected a nursing program as an occupational choice. Responses noted that "nursing is worth while work", "nursing provide a service to people". They also selected nursing as "a way of life" so that "they would be able to grow" and "be useful to others". These results were almost the same as those of the previous study. 2) In the last two years, students demonstrated a tendency to choose two or three reasons for selecting a nursing program. The number of students who chose the reason "for myself" and "as a study" also increased. 3) "Christianity" was a unique reason for choosing this college. "Good quality of education", "high estimation of graduated", "recommendation of others" were also main reasons. Over the last 13 years, there was no change in motivation for selecting a nursing program. However, students showed a tendency to provide several reasons for choosing nursing. There was an increase in the number of students who were 1) interested in nursing for their own satisfaction and 2) who saw nursing as a intellectual study.

Stimulatory effect of Saireito on proopiomelanocortin gene expression in the rat anterior pituitary gland.

The effect of administration of Saireito, a Saiko agent, via a stomach cannula on adrenocorticotropin (ACTH) release and gene expression of proopiomelanocortin (POMC), the precursor for ACTH, in the anterior pituitary, as well as on the corticotropin-releasing factor (CRF) in the hypothalamus, was examined in pentobarbital anesthetized rats. Saireito decreased the hypothalamic CRF level due to an early release of CRF and stimulated ACTH release and POMC gene expression but did not increase CRF gene expression. These results suggest that Saireito does not stimulate CRF gene expression, although it does stimulate CRF release, which in turn stimulates POMC gene expression in the anterior pituitary and ACTH release.

Neuropeptide Y increases the corticotropin-releasing factor messenger ribonucleic acid level in the rat hypothalamus.

Neuropeptide Y (NPY) has a stimulatory effect on adrenocorticotropin (ACTH) and corticotropin-releasing factor (CRF) release. In the present study, to investigate the effect of NPY on CRF synthesis, the effect of centrally administered NPY on CRF messenger RNA (mRNA) levels in rat hypothalamus was examined under pentobarbital anesthesia. The administration of 0.01, 0.1 and 1 nmol of NPY into the lateral ventricle dose-dependently Increased the plasma ACTH levels, as well as the levels of proopiomelanocortin mRNA in the anterior pituitary. The CRF mRNA level in the hypothalamus also increased after administration of 0.1 and 1 nmol of NPY in a dose-dependent manner. The administration of 3 nmol of phentolamine or propranolol failed to block 0.1 nmol NPY-induced ACTH release or 1 nmol NPY-stimulated CRF mRNA levels in the hypothalamus. These results Indicate that the central administration of NPY increases the CRF mRNA levels in the hypothalamus and the probable CRF release, which increases the proopiomelanocortin mRNA levels and ACTH secretion in the anterior pituitary. Therefore, NPY seems to play a physiological role in the regulation of the release and synthesis of CRF in the hypothalamus.

Beta-endorphin inhibits hypoglycemia-induced gene expression of corticotropin-releasing factor in the rat hypothalamus.

Endogenous opioid peptides have a role in the regulation of the hypothalamic-pituitary-adrenal axis. Recently, beta-endorphin (EP) has been thought to inhibit CRF release in vivo and in vitro. In the present study we examined the effects of central administration of EP on ACTH secretion and gene expression of both CRF in the hypothalamus and POMC in the anterior pituitary gland (AP) during basal and insulin-induced hypoglycemia in pentobarbital-anesthetized rats. Administration of EP in the lateral ventricle decreased basal CRF levels in the median eminence and inhibited basal and hypoglycemia-induced ACTH secretion in a dose-dependent manner. Hypoglycemia-induced POMC mRNA levels in the AP and CRF mRNA levels in the hypothalamus were also dose-dependently inhibited by the administration of EP. The inhibitory effect of EP was reversed by naloxone. These results suggest that 1) central administration of EP acts through the opioid receptor to inhibit hypoglycemia-induced CRF gene expression in the hypothalamus and CRF release, which results in a decrease in ACTH secretion and POMC mRNA levels in the AP; and 2) the active site of EP is the CRF neuron in the paraventricular nucleus.

[A case of secondary hemochromatosis, in which MRI is useful to evaluate therapeutic effect].

The therapeutic effects of phlebotomy were evaluated by MRI in a case of secondary hemochromatosis. Low intensity of the liver on T1 image remarkably changed and increased after treatment. MRI was very useful to value the changes of iron in the liver.

[Hepatocellular carcinoma with a complete remission of bone metastasis achieved by arterial chemotherapy].

Reported is the case of a hepatocellular carcinoma with a complete remission of the bone metastasis by arterial chemotherapy. The patient was 60 year old male, with the chief complaint being a tumor at the right side of the chest. The diagnosis was a hepatocellular carcinoma with a bone metastasis at the right 10th rib. The bone tumor showed no decrease in size after an intra-arterial injection of adriamycin, and radiation and or hyperthermia. Therefore, intra-arterial injections of mitomycin C mixed with lipiodol were instituted through the intercostal artery, and no bone tumor was noted after start of this therapy. Although the patient subsequently died, microscopic examination of a specimen obtained at autopsy revealed no malignant cells at the right 10th rib. Intra-arterial injections of anticancer agents mixed with lipiodol therefore are thought to be useful for the treatment of a bone metastasis.

Specific alteration of the form of selenium in fetal liver on maternal methylmercury treatment.

We have recently reported that maternal administration of methylmercury caused a striking increase in the selenium concentration in fetal liver accompanied by a decrease in selenium-dependent glutathione peroxidase (GSH-Px) activity. These changes resulted in the lowered bioavailability of selenium as far as the GSH-Px activity was concerned. The present study demonstrated that maternal administration of methylmercury caused a specific alteration of the form of selenium in fetal liver. Sephadex G-200 gel filtration of liver cytosols revealed an additional major peak of selenium in the fetal livers of mice treated with methylmercury. This peak was not present in the liver, kidney, or placenta of mothers treated with methylmercury.

[An autopsy case with a combination of hepatocellular carcinoma and cholangiocellular carcinoma].

A 68-year-old male was admitted to the Kurume University Hospital with a diagnosis of hepatocellular carcinoma (HCC). Serum CEA levels ranged from 3.7 ng/ml and 6.8 ng/ml during the course. Serum AFP levels were at normal range at admission and elevated to 13,250 ng/ml 3 months before death. He died of liver failure 17 months after admission. An autopsy disclosed diffuse infiltrative tumors distributed throughout the liver with metastasis to the bilateral lungs. Histologically, tumors of the liver consisted of elements of both HCC and cholangiolocellular carcinoma. Cholangiolocellular carcinoma is believed to occur from the canals of Hering or cholangiole, and this case may provide further information as to the histogenesis of combined HCC and cholangiocarcinoma.