Biomedical subjects

H Takiwaki

Publications and source records attributed to H Takiwaki.

At least 19 recordsLinked to original sources

PubMed2005

Bowen's disease on the sole: p16INK4a overexpression associated with human papillomavirus type 16.

We report a case of Bowen's disease on the sole presenting clinically as an exophytic, blackish-grey, verrucous tumour, and showing human papillomavirus (HPV) type 16 on analysis with polymerase chain reaction. Positive stains for HPV particles by immunohistochemical analysis were limited to several cell nuclei at the upper stratum Malpighii. However, all the tumour cells in the epidermis exhibited strong and diffuse nuclear and cytoplasmic stains for the tumour suppressor protein p16INK4a. We speculate that dysregulation of the retinoblastoma/p16INK4a pathway may be involved in the pathogenesis of the lesion, and p16INK4a overexpression might serve as a useful surrogate marker for identifying Bowen's disease harbouring high-risk types of HPV infection.

Adult↗

PubMed2003

Differences between intrafollicular microorganism profiles in perioral and seborrhoeic dermatitis.

Although often associated with overuse of topical corticosteroids, perioral dermatitis seems to develop seldom in patients with typical seborrhoeic dermatitis in spite of long-term application of corticosteroids. In order to compare the profiles of intrafollicular microorganisms in the lesions of perioral and seborrhoeic dermatitis, tape-stripped samples were obtained from eight lesions of perioral dermatitis, 10 lesions of seborrhoeic dermatitis, and the perioral skin of 31 normal subjects. After staining with Toluidine blue, resident microorganisms on plucked hair roots were evaluated microscopically. In all patients with perioral dermatitis and two normal subjects, 20-70% of sample hairs were positive for fusiform bacteria regarded as fusobacteria. Malassezia-positive hairs were rarely seen in these cases. Seborrhoeic dermatitis showed the opposite results. Perioral dermatitis may tend to develop under fusiform-bacteria-rich conditions, rather than Malassezia-rich conditions as in the case of seborrhoeic dermatitis.

Adult↗

PubMed2002

Skin reflectance-spectra and colour-value dependency on measuring-head aperture area in ordinary reflectance spectrophotometry and tristimulus colourimetry.

BACKGROUND/AIMS: Measurement of skin colour has become increasingly popular in the study of dermatology with the increased availability of portable instruments. However, different instruments have been reported as giving different results from measurement of the same skin region. The aim of this study was to examine the effects of differences in measuring-head aperture area on skin reflectance spectra and colour values. METHODS: We measured both reflectance spectra and CIE-L*a*b* values of the skin in five different anatomical regions on 10 subjects using two MINOLTA reflectance spectrometers that were identical apart from the aperture area of the measuring heads (diameters: 5 and 11 mm). For comparison, data were also obtained from a skin-coloured tile. RESULTS: Skin reflectance values measured with the wider-aperture instrument were higher than those measured with the other, irrespective of anatomical location. The differences between the two were near zero at an incident light wavelength of 400 nm, but increased to around 10% of the reflectance value at 700 nm, increasing exponentially with incident light of increasing wavelength. Skin colour was observed to be brighter, redder and yellower, in CIE-L*a*b* expression, when measured with the wider-aperture instrument. The differences between measurements obtained from the skin-coloured tile were much smaller. CONCLUSION: Skin reflectance and colour values measured with reflectance instruments are not absolute data but depend on the aperture area of the measuring head. This is probably due to variations in the proportion of longer-wavelength light reflected from the skin and collected by the instrument.

Adult↗

PubMed2002

Graphic analysis of the relationship between skin colour change and variations in the amounts of melanin and haemoglobin.

BACKGROUND/AIMS: The L*a*b* coordinate is the most commonly used colour system to measure skin colour in dermatology and cosmetology. In this system, a* and L* are often used for quantification of the degrees of erythema and pigmentation. The aim of this study was to examine whether a* and L* can be used as specific scales to indicate the amount of haemoglobin and melanin, respectively, in the skin. METHODS: The a* and L* values were examined with a reflectance spectrometer in various skin conditions or lesions caused by a change in the amount of either melanin or haemoglobin, i.e. vitiligo, ultraviolet-induced pigmentation (PG), erythema resulting from slapping (ER), corticosteroid-induced blanching, erythema due to stasis by arm lowering, and a combination of PG and ER. The differences in values between the test sites and the adjacent normal skin, deltaa* and deltaL*, were plotted on the deltaa*-deltaL* plane and analysed statistically and geometrically. RESULTS: L* depended substantially not only on melanin but also on haemoglobin, especially if the oxygen saturation level was expected to be low. a* was also influenced by melanin. The results of graphic analysis indicated that a linear transformation of (deltaa*, deltaL*) into (deltaHb = 1.68 deltaa* + 0.60 deltaL*, deltaMel =-1.06 deltaa*-1.44 deltaL*) was suitable for separately estimating the change in the amount of haemoglobin (deltaHb) and in that of melanin (deltaMel). CONCLUSION: The results of this study may be of value for understanding the relationship between colour coordinates of the skin and the quantities of haemoglobin and melanin, and may be of use when pigmented lesions of the face are monitored by tristimulus colourimetry, as facial skin colour is affected considerably by the rich and easily variable cutaneous blood flow.

Adult↗

PubMed2001

Localized heat urticaria: a clinical study using laser Doppler flowmetry.

We studied the pathophysiology of localized heat urticaria using laser Doppler flowmetry (LDF) in two patients with this rare disease. In heat challenge tests, performed with different challenge times and temperatures, a heat stimulator with a thermoregulated metal disc was utilized. Immediately after removal of the heat source, cutaneous blood flow (CBF) changes in the tested sites were monitored with LDF. In both patients the increase in (CBF) took place at some intervals after a heat challenge, synchronous with the start of the urticarial response. This interval, or the latency time (LT), showed distinct inverse proportion to the intensity of heat stimuli and was prolonged by effective treatments, such as application of antihistamines and repeated heat exposure by LDF. Therefore, the time of latency might be regarded as a good indicator of the severity of illness and therapeutic effectiveness, and thus might reflect the relationship between the degree of heat stimuli and the releasing process of chemical mediator(s) in patients with localized heat urticaria (LHU).

Administration, Topical↗

PubMed2000

Severe dermographism after topical therapy with diphenylcyclopropenone for alopecia universalis.

We describe here a 19-year-old Japanese man with an 11-year history of alopecia universalis, who, after the 1st application of a 0.003% diphenylcyclopropenone (DPCP) solution to the whole scalp, developed acute contact dermatitis at the test site, together with widespread severe dermographism. Every 3 weeks, persistence of the severe urticarial reaction and efficacy of treatment were monitored by constant pressure stimuli in a series of pressure tests, and subsequently evaluated by laser Doppler flowmetry (LDF). Although, on pressure tests, the urticarial response was found to significantly improve after starting treatment, erythematous responses continued to appear for nearly 3 months. The persistent course of these side-effects in our patient strongly suggests that precautions must currently be taken in the therapeutic use of potent sensitizers such as DPCP.

Administration, Topical↗

PubMed1998

Peripheral ulcerative keratitis associated with erythema elevatum diutinum and a positive rheumatoid factor: a report of three cases.

Peripheral ulcerative keratitis (PUK) is a complication of collagen-vascular diseases such as rheumatoid arthritis (RA) and other systemic vasculitides. We report three cases of erythema elevatum diutinum with PUK. These patients presented with nodules and plaques consistent with erythema elevatum diutinum on the extremities and crusted or ulcerated purpuric lesions on the soles. Histopathological examination of these lesions revealed a dense neutrophilic infiltrate with nuclear dust and fibrin around blood vessels. All the patients developed PUK concomitant with the development of the skin lesions. The rheumatoid factor was positive at high titre in all three patients; this was associated with probable RA in one. Cutaneous lesions were dramatically improved by administration of dapsone in all cases. Dapsone was also effective in treating the ocular lesions in two patients.

Aged↗

PubMed1998

Contact dermatitis due to 2,2'-azobis(2-amidinopropane) dihydrochloride: an outbreak in production workers.

2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) is an azo compound which has been used as a radical chain initiator. The purpose of this study was to confirm contact sensitivity to AAPH in individuals who were engaged in the production of AAPH, and presented with prolonged eczematous eruptions mainly on exposed areas. Patch testing was carried out with AAPH (1 and 5% aq.) on 8 patients and 6 healthy volunteers who had never been exposed to this chemical. All patients showed a strong positive patch test reaction to this agent, while all control subjects showed negative results. Because this chemical has recently been used for studies on the oxidation of biological materials, not only production workers in the chemical industry but also medical researchers should avoid prolonged exposure to this agent.

Adult↗

PubMed1998

Measurement of skin color: practical application and theoretical considerations.

Quantification of erythema and/or pigmentation is important for in vivo assessment of skin reactions to external stimuli such as ultraviolet radiation. Measurement of lesional color is also useful for quantitative evaluation of the efficacy of therapies for skin lesions. Several types of portable optoelectronic instruments have recently become available for these purposes and have been applied to research in dermatology, physiology, pharmacology, and cosmetic science. As color is not a genuine physical quantity but a sensory perception based on color vision, any colorimetric data obtained for the skin should be interpreted carefully. Erythema and melanin indices derived from skin reflectance data should also be evaluated in relation to the optical properties of the skin to avoid misuse. In this article, various methods for quantifying skin color and related parameters are reviewed and the characteristics of each method are discussed theoretically using an optical model of the skin.

Colorimetry↗

PubMed1997

A case of episodic angioedema associated with eosinophilia.

BACKGROUND: Gleich et al. first described 4 cases of episodic angioedema associated with eosinophilia as a distinct entity in 1984. Since then, several cases of this disorder have been reported in the United States, Europe and Japan. OBSERVATIONS: We report a case of a 22-year-old pregnant Japanese woman with this disorder. She had no fever and her general condition was good except the angioedema which was limited to her limbs. During an acute episode, her white blood cell count increased to 29,500/mm3 with 50% eosinophils, following an elevated serum interleukin-5 (IL-5) level. Spontaneous resolution occurred in 1 month after the onset. In a 5 month follow-up, no evidence of cardiac or other visceral organ involvement was found, and no recurrence occurred. CONCLUSIONS: Our case, combined with those reported in the literature, suggests that Japanese cases of episodic angioedema associated with eosinophilia differ from Caucasian cases in clinical symptoms and some other points.

Adult↗

PubMed1996

Squamous cell carcinoma associated with verruciform xanthoma of the penis.

We report a case of squamous cell carcinoma of the penis that seemed to arise within a verruciform xanthoma of this organ. A lesion in the prepuce was initially diagnosed as a verruciform xanthoma histopathologically and was removed in part. Six years later, the patient exhibited a well-differentiated squamous cell carcinoma of the penis that contained many clusters of xanthoma cells in the stroma. Although the retrospective examination of biopsy specimens of the initial lesion in this patient showed the features mainly of verruciform xanthoma, significant architectural and cytological atypia was also present in the overlying epidermis. Thus, we must be careful not to overlook the presence of a squamous cell carcinoma arising within a benign reactive lesion such as a verruciform xanthoma.

Carcinoma, Squamous Cell↗

PubMed1996

Guidelines for measurement of skin colour and erythema. A report from the Standardization Group of the European Society of Contact Dermatitis.

This report reviews individual-related variables (age, sex, race, anatomical site, skin surface properties), intra- and interindividual variation (temporal, physical and mental activity, orthostatic effect, menstrual cycle/menopause), environment-related variables (light conditions, temperature) and various instrument-related variables that influence skin colour. CIE colorimetry (Minolta Chroma Meter) and spectrophotometric measurement (Derma Spectrometer) are considered. The guidelines give recommendations for measuring conditions and procedures.

Adult↗

PubMed1995

A rudimentary system for automatic discrimination among basic skin lesions on the basis of color analysis of video images.

BACKGROUND: Detection of differences in color is necessary for an automatic diagnostic system for skin lesions. OBJECTIVE: The purpose of this study was to examine whether color analysis of an image obtained with a videomicroscope can be used as a key to distinguish basic skin lesions. METHODS: We carried out quantitative color analyses of nine kinds of natural or artificial skin lesions. After images of the lesion and adjacent normal skin were obtained, the difference in the mean quasiabsorbance (logarithm of the inverse reflectance) values between the two were examined in each color band of red, green, and blue by an image analytic method. RESULTS: We could determine a set of thresholds of quasiabsorbance values to distinguish between basic lesion colors. On the basis of these results we developed a rudimentary system that automatically offers possible diagnoses of a test site. CONCLUSION: The algorithm that we developed may be of value in an initial screening of skin lesions in an automatic diagnosis system.

Absorption↗

PubMed1995

Striated muscle hamartoma of the nostril.

We observed two females, an 11-month old and a 15-year-old, each with a round, soft mass in the nostril. Histologically, numerous bundles of striated muscle fibers were seen in the masses among normal dermal components. The lesions were excised without complications. Four patients with similar lesions confirmed clinically and histologically have been reported in the literature under various diagnostic names. These masses were diagnosed as striated muscle hamartomas in view of their characteristic features: congenital round, soft masses on the midline of the head or neck with multiple, mature striated muscles observed in the mass. Since these lesions may be associated with such anomalies as amniotic band syndrome and lipoma of the brain, a complete medical examination is required of such patients.

Adolescent↗

PubMed1994

The degrees of UVB-induced erythema and pigmentation correlate linearly and are reduced in a parallel manner by topical anti-inflammatory agents.

To examine whether it is possible to evaluate the degree of ultraviolet B (UVB)-induced inflammation by measuring the degree of hyperpigmentation, we investigated the relationship between UVB-induced erythema and the subsequent pigmentation quantitatively. At 24 h and 7 d after irradiation with erythemogenic doses of UVB to the backs of 16 Japanese subjects, the degree of induced erythema (delta erythema index) and that of pigmentation (delta melanin index) were examined by an image analytic method using a videomicroscope interfaced with a computer. The relationship between two indices was linear in each subject, and the correlation coefficient was 0.83 when evaluated using whole data. The slope of the regression line for the delta melanin index against delta erythema index tended to become steeper as non-irradiated skin color became darker (r = 0.63), suggesting that more efficient melanogenesis takes place after the same level of inflammation in the subject with darker skin. Both erythema and hyperpigmentation were suppressed significantly and in a parallel manner by corticosteroids and indomethacin applied topically immediately after UVB irradiation. These results imply that the post-inflammatory hyperpigmentation correlates closely with the severity of the prior inflammation and that chemical mediators released in the inflammatory process have considerable influence on the melanogenesis. We conclude that the measurement of UVB-induced hyperpigmentation can be utilized for the assessment of topical anti-inflammatory agents, unless these have direct actions on the tyrosinase activity of melanocytes.

Administration, Topical↗

PubMed1994

Quantification of erythema and pigmentation using a videomicroscope and a computer.

We report a method for quantitative analysis of erythema and pigmentation using a videomicroscope interfaced with a computer. The analysis was carried out by examining the brightness intensity of every picture element, composed of an image picked up from each band of red, green, and blue, and by deriving the quasi-absorbance value (absorbance index) from the mean brightness for each band. In assessments of UV-induced erythema and tanning, excellent linear correlations were found between the results obtained with our system and those with a narrow-band reflectance spectrometer. Moreover, the absorbance indices of haemoglobin and melanin solutions showed linear relationships with their concentrations in in vitro examination. As the monitored picture becomes out of focus if incorrect pressure is exerted on the skin, and as regions of interest can be chosen from a magnified image, this system offers excellent interobserver reproducibility, and is suitable for the evaluation of erythema or pigmented lesions which are too small or irregular to quantify by conventional methods such as colorimetry.

Adrenal Cortex Hormones↗

PubMed1994

Measurement of color parameters of psoriatic plaques by narrow-band reflectance spectrophotometry and tristimulus colorimetry.

Color parameters were measured on 50 psoriatic plaques in 10 patients, after scoring the amount of scales on them by inspection, with a narrow-band reflectance spectrophotometer (erythema/melanin index expression) and tristimulus colorimeter (CIE L*a*b* expression). Both erythema index a* (redness) were highest in the group of erythematous plaque with little scale (twice as high as in controls) and decreased significantly as the plaques were covered with thicker scale, while L* (brightness) changed in just the opposite fashion of a*. These portable 'color indicators' can be utilized to express the appearance of psoriatic plaques quantitatively, especially the extent of erythema and the amount of the scale on it.

Adult↗

PubMed1994

Variation in color and blood flow of the forearm skin during orthostatic maneuver.

To investigate the influence of arm position on the color and blood flow of the forearm skin, the CIE L*a*b* values, the erythema and melanin indices, and laser-Doppler blood flow values were recorded at three different arm positions (lowered, heart level and raised) in 15 healthy subjects using three kinds of optoelectronic instruments. The values of almost all color parameters, including the melanin index, changed stepwise significantly following the change in the arm position, and blood flow values decreased significantly during arm lowering. These results are most likely due to complex changes in the volume, flow rate and oxygen saturation level of the blood in the superficial vascular plexus, and their influences on each parameter were discussed. To use these instruments effectively for the quantitative evaluation of skin test reactions, a standardized arm position should be kept when the test is carried out in the forearm.

Adult↗