Neurochemical Properties of Dental Primary Afferent Neurons

The long belief that dental primary afferent (DPA) neurons are entirely composed of nociceptive neurons has been challenged by several anatomical and functional investigations. In order to characterize non-nociceptivepopulation among DPA neurons, retrograde transport fluorescent dye was placed in upper molars of rats and immunohistochemical detection of peripherin and neurofilament 200 in the labeled trigeminal ganglia was performed. As the results, majority ofDPA neurons were peripherin-expressing small-sized neurons, showing characteristic ofnociceptive C-fibers. However, 25.7% of DPA were stained with antibody against neurofilament 200, indicating significant portion of DPA neurons are related to large myelinated Abeta fibers. There were a small number of neurons thatexpressed both peripherin and neurofilament 200, suggestive of Adelta fibers. The possible transition of neurochemical properties by neuronal injury induced by retrograde labeling technique was ruled out by detection of minimal expression of neuronal injury marker, ATF-3. These results suggest that in addition to the large population of C-fiber-related nociceptive neurons, a subset of DPA neurons is myelinated large neurons, which is related to low-threshold mechanosensitive Abeta fibers. We suggest that these Abeta fiber-related neurons might play a role as mechanotransducers of fluid movement within dentinal tubules.

Involvement of Crosstalk Between cAMP and cGMP in Synaptic Plasticity in the Substantia Gelatinosa Neurons

Substantia gelatinosa (SG) neurons receive synaptic inputs from primary afferent Adelta- and C-fibers, where nociceptive information is integrated and modulated by numerous neurotransmitters or neuromodulators. A number of studies were dedicated to the molecular mechanism underlying the modulation of excitability or synaptic plasticity in SG neurons and revealed that second messengers, such as cAMP and cGMP, play an important role. Recently, cAMP and cGMP were shown to downregulate each other in heart muscle cells. However, involvement of the crosstalk between cAMP and cGMP in neurons is yet to be addressed. Therefore, we investigated whether interaction between cAMP and cGMP modulates synaptic plasticity in SG neurons using slice patch clamp recording from rats. Synaptic activity was measured by excitatory post-synaptic currents (EPSCs) elicited by stimulation onto dorsal root entry zone. Application of 1 mM of 8-bromoadenosine 3,5-cyclic monophosphate (8-Br-cAMP) or 8-bromoguanosine 3,5-cyclic monophosphate (8-Br-cGMP) for 15 minutes increased EPSCs, which were maintained for 30 minutes. However, simultaneous application of 8-Br-cAMP and 8-Br-cGMP failed to increase EPSCs, which suggested antagonistic cross-talk between two second messengers. Application of 3-isobutyl-1-methylxanthine (IBMX) that prevents degradation of cAMP and cGMP by blocking phosphodiesterase (PDE) increased EPSCs. Co-application of cAMP/cGMP along with IBMX induced additional increase in EPSCs. These results suggest that second messengers, cAMP and cGMP, might contribute to development of chronic pain through the mutual regulation of the signal transduction.

The Fitzpatrick skin type in Korean people / 대한피부과학회지

BACKGROUND: The Fitzpatrick skin type has been a simple and useful method to categorize cutaneous sensitivities to ultraviolet radiation. OBJECTIVE: In this study, we intended to know the distribution of Fitzpatrick skin type in Korean by interview method using questionnaire. METHODS: A total of 1296 Koreans from various districts were included in this study. Each subject was interviewed about their skin reactions to ultraviolet radiation and determined their skin type by interview method. To evaluate the statistical significance, we used generalized logit model. RESULTS: 1. The order of frequency of skin type was type III(48.8%), IV(22.2%), V(17.8%) by the interview method, with the sun sensitive categories(type I and type II) reported for 11.2%. 2. The skin type III was the predominant skin type in both men and women. However, skin type IV was found more frequently in men and it was statistically significant. 3. There is a tendency that frequency of skin type IV and V were increasing with advancement of age. 4. The Fitzpatrick skin type has some relationship with each individual`s occupation, the degree of sun exposure and their own skin color in Korean. CONCLUSION: This study included relative large numbers of subjects from various districts in Korea. It can be used as basic data for various studies related to cutaneous reactions to ultraviolet radiation.

The Fitzpatrick skin type in Korean people / 대한피부과학회지

BACKGROUND: The Fitzpatrick skin type has been a simple and useful method to categorize cutaneous sensitivities to ultraviolet radiation. OBJECTIVE: In this study, we intended to know the distribution of Fitzpatrick skin type in Korean by interview method using questionnaire. METHODS: A total of 1296 Koreans from various districts were included in this study. Each subject was interviewed about their skin reactions to ultraviolet radiation and determined their skin type by interview method. To evaluate the statistical significance, we used generalized logit model. RESULTS: 1. The order of frequency of skin type was type III(48.8%), IV(22.2%), V(17.8%) by the interview method, with the sun sensitive categories(type I and type II) reported for 11.2%. 2. The skin type III was the predominant skin type in both men and women. However, skin type IV was found more frequently in men and it was statistically significant. 3. There is a tendency that frequency of skin type IV and V were increasing with advancement of age. 4. The Fitzpatrick skin type has some relationship with each individual`s occupation, the degree of sun exposure and their own skin color in Korean. CONCLUSION: This study included relative large numbers of subjects from various districts in Korea. It can be used as basic data for various studies related to cutaneous reactions to ultraviolet radiation.

Treatment of Psoriasis with Calcipotriol-PUVA / 대한피부과학회지

BACKGROUND: PUVA photochemotherapy has been accepted as an effective treatment modality in the treatment of psoriasis. Many combination therapies have been tried to reduce the long-term side effects of UV radiation. OBJECTIVE: We performed conventional PUVA and calcipotriol-PUVA combination therapy to compare the effectiveness between two treatment modalities. METHODS: We treated 38 Korean patients with conventional PUVA and 54 with D-PUVA. We compared the total number, duration and total UVA dose of PUVA therapy to reach grade 4 between two groups. We categorized each patient into clearing, improvement, or failure groups based on the therapeutic efficacy, and evaluated PASI score at patient`s visits. RESULTS: The irradiation number and total cumulative dose of D-PUVA phototherapy to achieve grade 4 were significantly smaller than PUVA phototherapy. CONCLUSION: Combining PUVA with a vitamin D analogue, calcipotriol, in the treatment of psoriasis may lead to lowering the risk of long-term exposure to UV radiation with higher efficacy.

Narrow-Band UVB Phototherapy in Korean Psoriasis Patients / 대한피부과학회지

BACKGROUND: Narrow-band UVB phototherapy using 311+-2nm wavelength is in widespread use due to its greater efficacy and, possibly, safety compared with broad-band UVB sources. OBJECTIVE: We performed emollient narrow-band UVB(NBUVB) phototherapy to evaluate the clinical efficacy and safety in Korean psoriasis patients. METHODS: Fifteen psoriasis patients received narrow-band UVB phototherapy. We categorized each patient into clearing, improvement, or failure groups based on the therapeutic efficacy, and measured the PASI score every two weeks. RESULTS: 1. Among patients who received narrow-band UVB phototherapy, clearing was shown in 40.0% and improvement in 27.7%, and failure in 33.3%. 2. The total number, duration, final and cumulative doses to achieve grade IV were 16.3, 39 days, 1,050mJ/cm2 and 12,125mJ/cm2 respectively. 3. There were some side effects of NBUVB phototherapy such as pruritus(53.3%) and mild burning(13.3%). CONCLUSION: Narrow-band UVB phototherapy is a effective treatment modality which is convenient and less erythemogenic in psoriasis. It will be used more and more and play an important role in the treatment of psoriasis.

Two Cases of Photosensitive Psorasis / 대한피부과학회지

Photosensitive psoriasis is a rare disease defined as psoriasis in which the lesions deteriorate or new lesions develop after sun exposure. It should be differentiated from other photosensitive conditions that may be a vated or confused on sun-exposure. Half of the patients have a history of polymorphic light eruption(PMLE), whieh several weeks later develops into psoriasis lesions and the others have no history of preceding PMLE reaction. PUVA therapy is recommended for the treatment of choice. In this report, we describe two cases of photosensitive psoriasis. A 51-year-old woman without underlying psoriasis suffered from erythemato-squamous papular lesions on the face, neck and dorsum of hands after sun-exposure. She revealed a lowered minimal erythema dose(MED) for UVA which was confused with a photosensitive disease. But characteristic psariatic plaques on the elbow, knee and palm and histologic findings made the diagnosis photosensitive psoriasis. She showed a good result to cyclosporine therapy. The other patient, a 44-year-old woman with underlying psoriasis, experienced an exacerbation with preceding PMLE and showed a lowered erythema threshold for UVB. She was treated with sun-screen and topical corticosteroids.

Evaluation of Skin Surface Hydration in Diabetic Patients Using a Hydrometer and Corneometer / 대한피부과학회지

BACKGROUND: Diabetes mellitus is a common condition, and the majority of patients have one or more cutaneous complications. Among them, xerosis is well known to be closely related to diabetics. The xerosis is inversely reflected upon skin surface hydration, the state of which can be exactly assessed with various investigating instruments, such as a hydrometer and corneometer. OBJECTIVE: Our purpose was to compare the hydration state of diabetics with normal persons by the use of a corneometer and hydrometer. METHODS: A total of 267 diabetics were asked whether they felt xerosis or pruritus. In a subgroup of 31 patients, the water content was evaluated and compared by the parameters of diabetic severity. Forty-one non-diabetics were selected for the normal control.

The Efficacy and Sagety of Re-PUVA Combination Therapy for Psoriasis in Comparison with Retinoid and PUVA Monotherapy / 대한피부과학회지

BACKGROUND: Although retinoid and PUVA monotherapy is effective for psoriasis, both treatment regimens have some limitations because of the risk of long-term toxicity. OBJECTIVE: We performed Re-PUVA combination therapy to evaluate the clinical efficacy and safety in comparison with retinoid and PUVA monotherapy. METHODS: Seventy-eight psoriasis patients received Re-PUVA combination therapy as well as conventional retinoid and PUVA monotherapy. Pretreatment with etretinate for 1 week was followed by PUVA therapy in combination with etretinate. RESULTS: 1. Among patients who received Re-PUVA combination therapy, clearing was shown in 77.3% and improvement in 13.6%, which were higher than retinoid, 27.8%/61.1%, and PUVA monotherapy, 65.8%/21.0%.2. In patients who reached grade 4 with Re-PUVA therapy, the duration and total dose of etretinate were 56.4 days and 1616mg. These were significantly lower than retinoid monotherapy, 107.5 days and 2577.5mg.3. In patients who reached grade 4 with Re-PUVA therapy, the number and total dose of UVA were 13.3 and 82.8 J/cm2, which showed no difference compared with those of PUVA monotherapy, 16.2 and 120.2 J/cm2. However, excluding the cases who did not respond to previous monotherapy, the number and total dose of UVA in Re-PUVA were 10.4 and 49.0J/cm2, which were significantly lower than those of PUVA4. The side effects of Re-PUVA were reported in 54.5%, which were similar to PUVA monotherapy, 52.6%, and lower than retinoid monotherapy, 83.3%. There were some side effects of retinoid, such as cheilitis, dry mouth, elevation of sGOT/sGPT and triglycerides, and side effects of PUVA, such as itching, erythema, anorexia, nausea and vomiting. CONCLUSION: Our study suggests that Re-PUVA combination therapy is more effective and tolerable than retinoid and PUVA monotherapy in the treatment of psoriasis, especially in severe and recalcitrant cases.

The Evaluation of Attitudes toward Deleterious Effects of Sun-exposure and Behavioral Aspects of Using Sunscreens in Korea / 대한피부과학회지

BACKGROUND: Although deleterious effects of sunlight have been increased recently, the surveillance of the attitudes toward sun-exposure and the behavioral aspect of using sunscreens in Koreans has hot been cammied out. OBJECTIVE: Our purpose was to evaluate the attitude toward the harmfulness of sun-exposure and behaviors of using sunscreens in Korea. METHOD: Five hundred and fifty-two subjects were surveyed to assess the attitude toward sun-exposure, as well as the subjects' knowledge about, and the use of sunscreens. Underlying data including demographic data, skin colors, skin types, occupation, and sun-exposure, were obtained. RESULTS: Fifty-four percent of subjects believed that sun-exposure is bad for their skins, but, on the contrary, 12.5% believed it to be beneficial. Fifty-two percent of subjects used sunscreens. Almost all subjects(93.8%) knew why to use sunscreens but 62.7% of subjects did not know the meaning of sun protective factors(SPF). Women, indoor workers, subjects older than 40 yearsold, with less sun-exposed, fair colored skin, or with skin type I, II, III tended to know the deleterious effects of sunlight and the meaning of SPF and used more sunscreen. CONCLUSION: High risk population - men, outdoor workers, subjects less than 40 yearsold, with more sun-exposed, dark colored skin, or skin type VI, V could be targeted with campaigns that promote attitudinal and behavioral changes.

A Case of Lichen Amyloidosis Associated with Pdoriasis / 대한피부과학회지

Psoriasis is merely recognized as a disorder associated with pruritus. But in some cases, psoriasis does induce pruritus which could alter the daily lives of the people affected. Pruritus in psoriasis has been reported to be influenced by various external and internal factors and as a consequence, aggravation of psoriasis is possible by scratching due to the well-known Koebners phenomenen. Lichen amyloidosis, on the other hand, appears as multiple papules with intense pruritus. Recently, there are some evidence emphasizing pruritus as a main factor in forming amyloid deposits. We report a case of 65-year-old lady who was suffering psoriasis for 25 years with associated pruritic papular lesions on both of her thighs, knees and ankles. The diagnosis of Lichen amyloidosis was confirmed by Periodic Acid Schiff and Dylon stain. We discuss the role of pruritus in lichen amyloidosis and psoriasis and speculate that pruritus induced by lichen amyloidosis may induce a vicious cycle in aggravating psoriasis.

Coexistence of Bullous Pemphigoid and Psoriasis: A Case Report and Review of the Literature

There have been several reports in the literature of coexistent psoriasis and bullous pemphigoid. In most cases, the bullous pemphigoid lesions have been considered to be induced by antipsoriatic treatments. We describe a patient with psoriasis in whom bullous pemphigoid developed during psoriasis treatment, but the exact etiologic factor was not identified. Recently, some reports have suggested that an immunologic or biochemical association between the two diseases plays a role in the pathogenesis.

Erythema and Melanin Index According to UVB Radiation Doses by Use of a Reflectance Spectrophotometer in Korean Young Adults / 대한피부과학회지

BACKGROUND: Methods of estimating the erythema and pigmentation reactions, such as MPE (Minimal Perceptible Erythema), ME(Minimal Erythema Dose) and MMD(Minimal Melanogenic Dose), are vulnerable to the variations of subjective visual measurements. OBJECTIVE: By using objective and quantitative methods, the erythema and pigmentaton responses were investigated. METHODS: A sunlight, fluorescent lamp(Waldmann UV 800) was used as a UVB light source. Multiple sites of the lower back were irradiated with an increasing dose by a constant amount, With a reflectance spectrophotometer (DermaSpectrometer(R)), erythema and melanin indices at control, MPE, MED, MMD sites were assessed. The dose-response angle of erythema and pigmentation were calculated. RESULTS: The erythema and pigmetation indices at the control, MPE, MED and MMD sites were 8.7+/-2.0AU/30.5+/-2.6AU, 10.5+/-2.7AU/32.6+/-3.6AU, 13.2+/-3.5AU/32.6+/-3.3AU, and 10.4+/-3.0AU/ 33.5+/-2.7AU, respectively. The calculated dose-response angle accurately measured the response of skin to UVB irradiation. CONCLUSION: In this study, use of a reflectance spectrophotometer appeared to be a more sensitive and effective method than visual assessment, in addition, dose-response angles may be an objective index for determination of skin responses to UVB irradiation.

Relationship between UV-Induced Erythema and Pigmentation Dose-response Angles and The Predictors of Cutaneous Sensitivity to UV Light / 대한피부과학회지

BACKGROUND: There are many predictors of sensitivity to UVR, but controversies exist about their objectivity, correlation between them, and applicability to various races. OBJECTIVE: In 42 healthy volunteers, we assessed the validaty of dose response angle of erythe ma(DRAE) and delayed tanning(DRADT) after UVB irradiation, and also evaluated the correlation hetween dose-response angb s and other predictors of UV sensitivity. METHODS: We measured erythema and melanin index using reflectance spectrophotometer aft,er irradiation of UVB on the back of 42 males. When the erythema index and melanin index were plotted against UV doses for each patient, a dose response curve was obtained. Linear regression analysis was used to calculate the slope of those curves for erythema and delayed tanning, which were called DRAE and DRADl respectively. Also we checked predictots of UV sensitivity such as skin type, MED, MMD, consiitutional and facultative skin color, then analyzed the relation be tween dose response angles and other predictors. RESULTS: Statistically significa it linear regression lines were obtained from 41 subjects regarding to erythema and frorn 31 subjects regarding to delayed tanning. As for the relationship he tween the pvedictors of UV senitivity, only the MED correlated well with DRAE. CONCLUSION: We found that dose response angles, especially DRAE, were an objective and adequate predictor of cutaneous LJV sensitivity, but could not find validity of skin type and skin color in Koreans. A more organized study with a larger number of subjects is needed to clarify the usefulness of the predictors.