Similar short-term KOOS between open-wedge high tibial osteotomy and total knee arthroplasty in patients over age 60: A propensity score-matched cohort study

OBJECTIVES

The purpose of the present study was to evaluate improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) after open-wedge high tibial osteotomy (HTO) in comparison with total knee arthroplasty (TKA) in cohorts over age 60 matched by pre-operative age, gender, body mass index (BMI), hip-knee-ankle angle (HKAA), KOOS sub-scores, and osteoarthritis (OA) grade.

METHODS

Propensity score matching was performed between 162 HTO patients and 134 TKA patients. When calculating the propensity score by multivariate logistic regression analysis, the following pre-operative confounders were included: age, gender, BMI, HKAA, KOOS sub-scores, and OA grade. Consequently, a total of 55 patients were included in each group. The Student's t-test was used to analyse differences in the post-operative KOOS sub-scores between groups.

RESULTS

After propensity score matching, all matched pre-operative valuables were identical, with no significant differences between the HTO and TKA groups. None of the post-operative KOOS sub-scores at 1 year after surgery showed a significant difference between the HTO and TKA groups. Both groups demonstrated significant and comparable post-operative improvement in every KOOS sub-score.

CONCLUSIONS

In patients over age 60, there was no significant difference in short-term pain relief and improvements in activity and quality of life between HTO and TKA after propensity score matching including pre-operative age, KOOS sub-scores, and OA grade. HTO is a joint preservation procedure that is valid for knee OA even in individuals over age 60.

Patient-specific prediction of joint line convergence angle after high tibial osteotomy using a whole-leg radiograph standing on lateral-wedge insole

PURPOSE

To assess the usefulness of a whole-leg radiograph standing on lateral-wedge insole (LWI) for predicting the change in joint line convergence angle (JLCA) before vs. after high tibial osteotomy (HTO).

METHODS

Forty knees with medial osteoarthritis underwent open-wedge HTO. Pre-operatively, all patients had whole-leg radiographs taken in three different conditions: supine, standing, and standing on LWI inclined at 20°. A standing whole-leg radiograph was also obtained post-operatively. Radiological measurements including JLCA and percentage of mechanical axis (%MA) were compared. Using pre-operative radiographs, correction angles were calculated with the target %MA at 62.5%. Correlations between the difference in calculated correction angle among the three pre-operative conditions and the change in JLCA before vs. after HTO were assessed.

RESULTS

In the pre-operative standing conditions, the mean JLCA of 3.8° was significantly decreased to 3.2° using LWI, which did not differ from post-operative JLCA of 3.1°. Mean %MA significantly shifted laterally from 20.6 to 24.8% using LWI, and was strongly correlated with the change in JLCA (coefficient, 0.83). Calculated correction angles differed significantly among the three pre-operative conditions. The difference in calculated correction angle between standing with and without LWI was strongly correlated to the change in standing JLCA before vs. after HTO (coefficient, 0.73).

CONCLUSION

Larger differences in calculated correction angles between pre-operative radiographs standing with and without LWI predicted larger changes in JLCA after HTO. Whole-leg radiograph standing on LWI is a promising modality for correct pre-operative planning considering patient-specific changes in JLCA before vs. after HTO.

LEVEL OF EVIDENCE

IV.

Distal tuberosity osteotomy in open-wedge high tibial osteotomy does not exacerbate patellofemoral osteoarthritis on arthroscopic evaluation

PURPOSE

The purpose of the present study was to use arthroscopy to evaluate the effect of distal tuberosity osteotomy (DTO) in open-wedge high tibial osteotomy (OW-HTO) on patellofemoral (PF) cartilage degradation.

METHODS

Between 2012 and 2017, 46 knees underwent DTO in OW-HTO, and 65 knees underwent conventional OW-HTO (cOW-HTO). To assess changes in patellar height, the Blackburne-Peel (BP) ratio and the Caton-Deschamps (CD) index were measured. Arthroscopic evaluation on the PF joint was performed at the initial osteotomy and at the second-look procedure 1 year later. Statistical analyses were performed to compare difference between the DTO and the cOW-HTO group.

RESULTS

In the cOW-HTO group, the mean BP ratio and CD index decreased significantly from 0.81 and 0.89 preoperatively, respectively, to 0.69 and 0.76 postoperatively, respectively (p < 0.001). In contrast, the DTO group maintained a consistent patellar height; the mean BP ratio and CD index were 0.77 and 0.83 preoperatively, respectively, and 0.73 and 0.80 postoperatively, respectively. Upon arthroscopic evaluation, 39 of 46 patients (84.8%) in the DTO group showed no progression of PF cartilage degradation at the second look; indeed, five of 46 patients (10.9%) even demonstrated improvement. In contrast, 21 of 65 patients (32.3%) in the cOW-HTO group exhibited increased PF cartilage degradation. There was a significant difference in progression of PF cartilage degradation between DTO and cOW-HTO (p < 0.001).

CONCLUSION

DTO in OW-HTO maintained the preoperative patellar height, which could help prevent progression of cartilage degeneration in the PF joint after surgery. In respect of the biplanar osteotomy direction in OW-HTO, the DTO, rather than cOWHTO, is the preferred technique for the treatment of varus knee osteoarthritis to avoid progression of PF cartilage degradation.

LEVEL OF EVIDENCE

III.

Comparison of ultrasonic pachymetry and Fourier-domain optical coherence tomography for measurement of corneal thickness in dogs with and without corneal disease

Several ultrasonic and Fourier-domain optical coherence tomography (FD-OCT) pachymeters are used to measure corneal thickness in canine patients and research subjects. This study assessed the reliability of and consistency between two ultrasonic pachymetry (USP) devices, Pachette 3 and Accupach VI, as well as automated and manual measurements obtained using FD-OCT in dogs with and without corneal disease. Corneal thickness measurements were compiled from 108 dogs and analyzed using mixed effects linear regression, with Bonferonni adjustments for post-hoc comparisons, to determine the effects of age, weight and disease state. Data are presented as predicted mean±standard error. Canine corneal disease can result in marked increases in thickness that frequently exceed the upper limits of measurement of some pachymetry devices developed for human use. In this study, the corneas of dogs with endothelial disease or injury frequently exceeded the upper limits of quantitation of 999 and 800μm for the Accupach VI and automated FD-OCT pachymeters, respectively. Using values <800μm, the Pachette 3 generated significantly greater values for central corneal thickness (CCT) than the Accupach VI, manual FD-OCT and automated FD-OCT at 625±7.0, 615±7.2, 613±7.2, and 606±7.4μm respectively (P<0.001). Of the two devices where measurements >1000μm were obtained, manual FD-OCT demonstrated less variability than the Pachette 3. Corneal thickness increased linearly with age and weight with an increase of 6.9±1.8μm/year and 1.6±0.8μm/kg body weight (P<0.005 and P=0.038, respectively).

Influence of neutralizing antibodies to adalimumab and infliximab on the treatment of psoriasis

BACKGROUND

Current treatment with biologics has produced dramatic therapeutic effects in patients with psoriasis, although these agents occasionally decrease in efficacy. One of the main factors responsible for this attenuation is attributed to the development of antidrug antibodies (ADAs).

OBJECTIVES

To analyse the relationship between serum drug concentrations, the presence of ADAs and treatment efficacy of adalimumab and infliximab, and to determine the optimal use of these biologics.

METHODS

This was a 1-year prospective study in the dermatology departments of Kobe University Hospital and collaborating hospitals. All patients starting a regimen of adalimumab and infliximab for psoriasis were included. We measured the serum concentration of the drugs and titres of antibodies to adalimumab and infliximab, as well as the Psoriasis Area and Severity Index scores at weeks 0, 4, 12, 24 and 48 during the first year of treatment.

RESULTS

We observed a 50% positive rate of ADAs to adalimumab, and a 41% positive rate of ADAs to infliximab. The titres of ADAs showed a wide range from low to high titres. In the high-titre groups, the patients exhibited a decreased clinical response, and demonstrated a negative correlation between titre and clinical response. However, an equivalent therapeutic effect was observed between the low-titre group and the group with no antibodies detected for adalimumab. For infliximab, the patients with ADAs showed decreased clinical response. An apparent negative correlation between antibody production and reduced clinical response was observed.

CONCLUSIONS

Two biologics, adalimumab and infliximab, showed different therapeutic behaviour. The measurement of ADAs and drug concentrations has important implications for treatment with biologics.

Neural decoding of visual imagery during sleep

Visual imagery during sleep has long been a topic of persistent speculation, but its private nature has hampered objective analysis. Here we present a neural decoding approach in which machine-learning models predict the contents of visual imagery during the sleep-onset period, given measured brain activity, by discovering links between human functional magnetic resonance imaging patterns and verbal reports with the assistance of lexical and image databases. Decoding models trained on stimulus-induced brain activity in visual cortical areas showed accurate classification, detection, and identification of contents. Our findings demonstrate that specific visual experience during sleep is represented by brain activity patterns shared by stimulus perception, providing a means to uncover subjective contents of dreaming using objective neural measurement.

Soybean beta-conglycinin as the main allergen in a patient with food-dependent exercise-induced anaphylaxis by tofu: food processing alters pepsin resistance

BACKGROUND

Food-dependent exercise-induced anaphylaxis (FDEIA) due to soybeans is a rare disorder. The allergen responsible for FDEIA due to soybeans has not yet been determined.

OBJECTIVE

We characterized the clinical features of a patient with FDEIA due to tofu, who was well tolerant to drinking soy milk. We then sought to identify the responsible soybean allergen(s) in that patient. We further studied whether different stabilities of the allergen(s) to pepsin digestion between two soybean products are related to their clinical allergenicity.

METHODS

Skin prick tests and provocation tests using soybean products were performed to detect the responsible food and other factors that induced the allergic symptoms. Specific IgE to various soybean allergens were examined by ImmunoCAP, ELISA and protein microarray assays. Immunoblotting for soybeans and soybean products using the patient's serum was also performed. Soybean products were serially digested by pepsin to disclose the stability of the allergens.

RESULTS

Provocation with ingestion of tofu and exercise induced the allergic symptoms, while ingestion of soy milk and exercise did not. Immunoblot analysis, ELISA and protein microarray assay revealed that beta-conglycinin mainly reacts with IgE antibodies in the patient's serum. By immunoblot analysis, beta-conglycinin in soy milk completely disappeared after pepsin digestion within 20 min, whereas beta-conglycinin in tofu was almost intact after more than 120 min of pepsin digestion.

CONCLUSION

We identified beta-conglycinin as the causative allergen in a patient with FDEIA induced by tofu. The difference in resistance to pepsin digestion between tofu and soy milk suggests that the presence of undigested allergens in the digestive tract is a prerequisite for the development of FDEIA.

Association of T-cell receptor Vbeta haplotypes with dry skin in DS-Nh mice

BACKGROUND

Although dry skin and T cell-dependent disease exacerbation are characteristic features of atopic dermatitis (AD), the involvement of T cells in the development of dry skin remains unclear.

AIMS

We aimed to elucidate the role of T cells in the development of dry skin in DS-Nh mice as a model for AD, and to evaluate this skin condition pharmacologically.

METHODS

We prepared DS-Nh mice harbouring a T-cell receptor (TCR)Vbeta(a) haplotype with a central deletion in the TCRBV gene segments, and mice harbouring a TCRVbeta(b) haplotype without any deletion. We analysed the TCRVbeta chain usage and cytokine response to antimouse CD3 monoclonal antibodies in the splenocytes from the two mouse substrains. Transepidermal water loss (TEWL) was measured, and histochemical examination of these mice was carried out. Finally, a pharmacological analysis using loratadine was also performed to evaluate the features of spontaneous dry skin in DS-Nh mice as a model of AD.

RESULTS

Although the deletion of TCRBV gene segments in the TCRVbeta(a) haplotype yielded different representations of each TCRVbeta mRNA, this deletion did not evoke distinct cytokine profiles in the splenocytes compared with those of mice with the TCRVbeta(b) haplotype. Furthermore, our results indicated that the onset of dry skin occurred earlier in mice with TCRVbeta(b) than in those with TCRVbeta(a). Pharmacologically, AD-like dry skin in DS-Nh with TCRVbeta(b) mice is susceptible to an H1 blocker.

CONCLUSIONS

A specific lymphocyte subpopulation bearing T-cell receptors may be responsible for loratadine-responsive dermatitis in DS-Nh mice.

Skew in T cell receptor usage with polyclonal expansion in lesions of oral lichen planus without hepatitis C virus infection

Oral lichen planus (OLP) is a refractory disorder of the oral mucosa. Its predominant symptoms are pain and haphalgesia that impair the quality of life of patients. OLP develops via a T cell-mediated immune process. Here, we examined the characteristics of the infiltrating T cells in terms of the T cell receptor (TCR) repertoires, T cell clonality, T cell phenotypes and cytokine production profiles. TCR repertoire analyses and CDR3 size spectratyping were performed using peripheral blood mononuclear cells (PBMCs) and tissue specimens of OLP biopsies from 12 patients. The cytokine expression profiles and T cell phenotypes were measured by real-time quantitative polymerase chain reaction. We observed that there were skewed TCR repertoires in the tissue samples (TCRVA8-1, VA22-1, VB2-1, VB3-1 and VB5-1) and PBMCs (TCRVA8-1, VB2-1, VB3-1 and VB5-1) from OLP patients. Furthermore, the CDR3 distributions in the skewed TCR subfamilies exhibited polyclonal patterns. We observed increases in CD4(+) T lymphocytes, interleukin (IL)-5, tumour necrosis factor (TNF)-alpha and human leucocyte antigen D-related in the OLP tissue specimens. Taken together, the present results suggest that T cells bearing these TCRs are involved in the pathogenesis of OLP, and that IL-5 and TNF-alpha may participate in its inflammatory process.

Association of human herpesvirus 6 reactivation with the flaring and severity of drug-induced hypersensitivity syndrome

BACKGROUND

Drug-induced hypersensitivity syndrome (DIHS) is an adverse reaction with clinical signs of fever, rash and internal organ involvement. In the vast majority of patients in Japan, the causative drugs for DIHS are limited to the following eight: carbamazepine, phenytoin, phenobarbital, zonisamide, mexiletine, dapsone, salazosulfapyridine and allopurinol. The association of human herpesvirus (HHV)-6 reactivation with DIHS has been reported by various groups.

OBJECTIVES

To confirm the relationship between the flaring and severity of DIHS and HHV-6 reactivation.

METHODS

We evaluated 100 patients with drug rash and systemic symptom(s) caused by the drugs associated with DIHS. HHV-6 reactivation was examined by serological antibody assay and quantitative real-time polymerase chain reaction assay of serial serum samples.

RESULTS

Anti-HHV-6 IgG titres increased in 62 of 100 patients, 14-28 days after the onset of symptoms. These patients suffered from severe organ involvement and a prolonged course compared with 38 patients showing no reactivation of HHV-6. Significant amounts of HHV-6 DNA were detected in serum samples from 18 of the 62 patients. Flaring of symptoms such as fever and hepatitis was closely related to HHV-6 reactivation in these 18 patients. It should be emphasized that all five patients with fatal outcome and 10 patients with renal failure were in the HHV-6 reactivation group.

CONCLUSIONS

A combination of immunological reaction to a drug and HHV-6 reactivation results in the severe course of DIHS. The demonstration of HHV-6 reactivation is a useful marker of diagnosis as well as prognosis in DIHS.

Spontaneous scratching behaviour in DS-Nh mice as a possible model for pruritus in atopic dermatitis

Itching is one of the major clinical symptoms in atopic dermatitis (AD) and complicates the management of this pathological condition. An animal model of AD-like pruritus would contribute to a better understanding of AD and could lead to the development of safe and effective antipruritic agents. DS non-hair (DS-Nh) mice raised under conventional conditions spontaneously develop pruritus, which is associated with a dermatitis similar to human AD. There is a significant positive correlation between disease severity and the period of scratching behaviour in DS-Nh mice. In the present study, we found that levels of histamine and nerve growth factor (NGF) in serum and/or skin tissue were higher in DS-Nh mice with AD-like dermatitis than in age-matched mice without dermatitis. The histopathological data indicated that nerve fibres extend into and mast cells infiltrate the surrounding area of the skin lesion. NGF production by XB-2 cells, which was derived from mouse keratinocytes, was enhanced by histamine via the H1 receptor. We also found that prolonged treatment with an H1-antagonist was effective against pruritus through depression of the production of NGF, which is thought to be generated by keratinocytes. We conclude that DS-Nh mice can serve as a suitable model for gaining a better understanding of pruritus in AD, and that prolonged treatment with an H1-antagonist may be beneficial in patients with AD-associated pruritus.

The inhibition spectrum of solar urticaria suppresses the wheal-flare response following intradermal injection with photo-activated autologous serum but not with compound 48/80

BACKGROUND

The inhibition spectrum (IS) in solar urticaria was identified mainly in Japanese patients with solar urticaria, although the mechanism of action of the IS has not been elucidated.

METHODS

Because an intradermal injection of action spectrum (AS)-irradiated serum in a case of solar urticaria induced a wheal response, we studied the responsiveness of the intradermal injection after an IS irradiation.

RESULTS

An AS in this patient was composed of visible light shorter than 500 nm, while an IS was composed of visible light longer than 530 nm. When the IS was exposed immediately after the AS irradiation, the wheal response was inhibited. However, when the IS was exposed before the AS irradiation, the wheal response was not inhibited. An intradermal injection of her serum produced no reaction, whereas an intradermal injection of her serum pre-irradiated with visible light induced a wheal flare response. Further examination revealed that the in vivo wheal-inducing activity of her serum irradiated with visible light could be attenuated by post-IS irradiation at the injection site, while the wheal-inducing activity of her visible light-irradiated serum was not inhibited by irradiation of the activated serum with the IS. The wheal-flare response induced by compound 48/80 and histamine was not altered by IS irradiation at the site of skin tests.

CONCLUSION

These findings indicate that photoallergens in the patient's serum that are activated by visible light irradiation are responsible for the development of her symptoms and that the IS may suppress the wheal response by inhibiting the binding of the photoallergens to mast cells, not by inactivating the photoallergens and stabilizing mast cells.

Detection of guinea pig macrophages by a new CD68 monoclonal antibody, PM-1K

A new monoclonal antibody, PM-1K, was raised against 24-h cultured human peritoneal macrophages. In immunohistochemical assays, PM-1K recognized freshly isolated blood monocytes and most tissue macrophages as well as myeloid dendritic cells such as Langerhans cells and interdigitating cells. The molecular size of the antigen recognized by PM-1K was determined to be 110 kD by means of immunoaffinity purification. Because this affinity-purified antigen recognized by PM-1K was also recognized by anti-CD68 antibodies, it is believed to be one of the heterogeneous molecules of the CD68 antigen. Analysis showed interspecies reactivity of PM-1K with macrophages from guinea pigs, pigs, bovine species, and monkeys. Among these macrophages, those of the guinea pig reacted strongly with PM-1K. Patterns of PM-1K immunostaining in guinea pig tissues were similar to those found in human tissues. Studies with the immunoelectron microscope revealed reaction products of PM-1K in the cytoplasm, especially around endosomes. Since only a few antibodies are available to label guinea pig macrophages, PM-1K is considered to be one of the most suitable antibodies to examine macrophages in experimental guinea pig models.

AM-3K, an anti-macrophage antibody, recognizes CD163, a molecule associated with an anti-inflammatory macrophage phenotype

CD163 is a member of the scavenger receptor cysteine-rich superfamily restricted to the monocyte/macrophage lineage and is thought to be a useful marker for anti-inflammatory or alternatively activated macrophages. In this study we used mass spectrometric analysis to determine that the antigen recognized by the antibody AM-3K, which we previously generated as a tissue macrophage-specific monoclonal antibody, was CD163. An anti-inflammatory subtype of macrophages stimulated by dexamethasone or interleukin-10 showed strong reactivity for AM-3K and increased expression of CD163 mRNA. Immunohistochemical staining of routinely processed pathological specimens revealed that AM-3K recognized a specialized subpopulation of macrophages. In granulomatous diseases such as tuberculosis, sarcoidosis, or foreign body reactions, tissue macrophages around granulomas, but not component cells of the granulomas such as epithelioid cells and multinucleated giant cells, showed positive staining for AM-3K. In atherosclerotic lesions, scattered macrophages in diffuse intimal lesions were strongly positive for AM-3K, whereas foamy macrophages in atheromatous plaques demonstrated only weak staining. We therefore suggest that, in routine pathological specimens, AM-3K is a useful marker for anti-inflammatory macrophages because these cells can be distinguished from inflammatory or classically activated macrophages. Because AM-3K cross-reacts with macrophage subpopulations in different animal species including rats, guinea pigs, rabbits, cats, dogs, goats, pigs, bovine species, horses, monkeys, and cetaceans, it will have wide application for detection of CD163 in various animals.

Development of a simple method to evaluate medical staff radiation dose and its application to a software system supporting PET facility operation

In recent years, positron-emitting labelled radiopharmaceuticals have come to be used in conjunction with positron emission tomography (PET) in various clinical diagnoses. Radiation exposure of the medical staff is a key issue in the design of PET facilities intended to handle large numbers of persons for PET diagnosis. As a first step, the radiation dose to individuals who received radiopharmaceuticals was calculated using a mathematical phantom model and the EGS4 electromagnetic cascade Monte Carlo code and MCNP Monte Carlo code. Dose rate behind a lead shield was also calculated for various lead thicknesses. The radiation dose distribution around a syringe containing a positron emitter was calculated. The calculated dose distributions were fitted to polynomial equations. These calculations were evaluated against measurements. The second step was to evaluate medical staff dose at a specified time by superimposing dose distribution from each person who received radioisotopes taking into account radioactive decay. In this way, we developed software to support PET facility operation, namely, planning, prediction, control of medical staff dose and facility operation. This system was also designed to schedule daily radiopharmaceuticals production and to manage radioactive wastes by taking decay time into account.

Preparation and characterization of high-specific-surface-area activated carbons from K2CO3-treated waste polyurethane

An activated carbon with high specific surface area was prepared from polyurethane foam by chemical activation with K2CO3 and the influences of carbonization temperature and impregnation ratio on the pore structure of the prepared activated carbon were investigated. It was found that the specific surface area of the activated carbon was at a maximum value (about 2800 m(2)/g) at a carbonization temperature of 1073 K and at an impregnation ratio of 1.0. It was concluded that the polyurethane foam structure was modified during impregnation by K2CO3, K2CO3 promoted charring during carbonization, and then the weight loss behavior was changed below 700 and above 1000 K, carbon in the char was consumed by K2CO3 reduction, and this led to the high specific surface area. The prepared activated carbon had a very sharp micropore size distribution, compared with the commercial activated carbon having high specific surface area. The amounts of three organic vapors (benzene, acetone, and octane) adsorbed on the prepared activated carbons was much larger than those on the traditional coconut shell AC and the same as those on the commercial activated carbon except for octane. We surmised that the high specific surface area was due to the modification of the carbonization behavior of polyurethane foam by K2CO3.

Nasal-type natural killer cell lymphoma preceded by benign panniculitis arising in an asymptomatic HTLV-1 carrier

We report a case of an Epstein-Barr virus (EBV)-associated nasal-type natural killer cell lymphoma (NKCL) preceded by benign panniculitis, which arose in a 48-year-old woman with an asymptomatic human T-cell leukemia/lymphoma virus type-1 (HTLV-1) infection. A biopsy of the initial panniculitis lesion demonstrated lobular panniculitis with a germinal center composed of benign mononuclear cells with a phenotype of CD4+CD45RO+CD5sCD3+ cCD3 epsilon + T-cell intracellular antigen-1 (TIA-1)- and granzyme B-. One year after oral prednisolone therapy, the patient developed subcutaneous nodules composed of atypical lymphoid cells with a phenotype of CD4-CD45RO+CD56+sCD3-cCD3 epsilon + (TIA-1)+ and granzyme B+. In the initial panniculitis lesion, neither EBV-encoded RNA (EBER-1) nor clonal proliferation of EBV-infected cells was identified. In later lesions, however, a large number of atypical cells were positive for EBER-1, and a clonal expansion of EBV-infected cells was detected. No clonal rearrangement of T-cell receptor-alpha, -beta, or -gamma genes was found in either specimen. This patient was an asymptomatic carrier of human T-cell leukemia/lymphoma virus type-1 (HTLV-1) without clonal integration of proviral HTLV-1 in neither the peripheral blood nor the skin lesions. These observations suggest that EBV-associated NKCL occurred subsequently in the clinical course of benign panniculitis under the influence of immunosuppression caused by prednisolone treatment and HTLV-1 infection.

UV-induced skin damage

Solar radiation induces acute and chronic reactions in human and animal skin. Chronic repeated exposures are the primary cause of benign and malignant skin tumors, including malignant melanoma. Among types of solar radiation, ultraviolet B (290-320 nm) radiation is highly mutagenic and carcinogenic in animal experiments compared to ultraviolet A (320-400 nm) radiation. Epidemiological studies suggest that solar UV radiation is responsible for skin tumor development via gene mutations and immunosuppression, and possibly for photoaging. In this review, recent understanding of DNA damage caused by direct UV radiation and by indirect stress via reactive oxygen species (ROS) and DNA repair mechanisms, particularly nucleotide excision repair of human cells, are discussed. In addition, mutations induced by solar UV radiation in p53, ras and patched genes of non-melanoma skin cancer cells, and the role of ROS as both a promoter in UV-carcinogenesis and an inducer of UV-apoptosis, are described based primarily on the findings reported during the last decade. Furthermore, the effect of UV on immunological reaction in the skin is discussed. Finally, possible prevention of UV-induced skin cancer by feeding or topical use of antioxidants, such as polyphenols, vitamin C, and vitamin E, is discussed.

DS-Nh as an experimental model of atopic dermatitis induced by Staphylococcus aureus producing staphylococcal enterotoxin C

DS-Nh mice raised under conventional conditions spontaneously develop dermatitis similar to human atopic dermatitis (AD), which is associated with staphylococcal infection. In the present study, we show that Staphylococcus aureus producing staphylococcus exotoxin C (SEC) was recovered from the culture of the skin lesions of DS-Nh mice with AD-like dermatitis and that the serum levels of anti-SEC antibodies from these mice were elevated. We describe here how to promote experimental AD by epicutaneous injection with SEC-producing S. aureus to DS-Nh mice. In order to assess the role of SEC in the pathogenesis of AD, the mitogenic activity, TCRBV repertoire analysis and the production of IL-4 and IFN-gamma from spleen mononuclear cells (MNC) from DS-Nh stimulated by SEC were compared with those due to SEA, SEB and TSST. The weakest was the mitogenic activity of SEC, and higher IL-4 responses and lower IFN-gamma responses to SEC showed correlation with TCRBV8S2-positive T cells, which were selectively stimulated by SEC. We also demonstrate that SEC-producing S. aureus was able to survive in DS-Nh after intradermal injection. These results suggest a possible role for SEC in the pathogenesis of AD through host-S. aureus relationships.

Localized heat urticaria in a patient is associated with a wealing response to heated autologous serum

We report a case of localized heat urticaria in a 71-year-old woman who developed weals and loss of consciousness after taking a bath. Exposing her skin to heat at 40 degrees C or immersing her hands in water at 40 degrees C produced urticarial lesions and increased her plasma histamine level. Desensitization with hot water improved her symptoms and normalized her plasma histamine level after heat challenge. An intracutaneous injection of her serum produced no reaction, while an injection of her serum that had been heated at 40 degrees C for 15 min induced a weal flare response. Further examination revealed that the weal-inducing activity of her heated serum remained for at least for 6 h and that treatment of her serum at 60 degrees C for 2 h did not abrogate its weal-inducing activity. These findings indicate that certain materials in her serum that are activated by heat are responsible for the development of her anaphylactic and urticarial reactions and that these reactions may be mediated by histamine.

A practical preparation of methyl 2-methoxy-6-methylaminopyridine-3-carboxylate from 2,6-dichloro-3-trifluoromethylpyridine

An effective and practical synthetic route to methyl 2-methoxy-6-methylaminopyridine-3-carboxylate (7), the key intermediate of 5-bromo-2-methoxy-6-methylaminopyridine-3-carboxylic acid (1), from 2,6-dichloro-3-trifluoromethylpyridine (12) was undertaken. Process improvements were highlighted by regioselectivity of 12 with a nitrogen nucleophile and conversion of the 3-trifluoromethyl group into the methoxycarbonyl group. The reaction of 12 with N-benzylmethylamine provided the 6-(N-benzyl-N-methyl)aminopyridine 26a and the regioisomer 26b in >98:<2 ratio in a quantitative yield. Treatment of 2-methoxy-6-methylamino-3-trifluoropyridine (14a) with a large excess of sodium methoxide followed by acid hydrolysis gave the pyridine-3-carboxylic ester 7 in an excellent yield. The potential application of this reaction is also described.

Inhibition of the motility and growth of B16F10 mouse melanoma cells by dominant negative mutants of Dok-1

Dok-1 (p62(Dok)) is a multiple-site docking protein that acts downstream of receptor and nonreceptor tyrosine kinases. Although it has been proposed to contribute to the control of cell growth and migration through association with the Ras GTPase-activating protein and the adapter protein Nck, the role of Dok-1 remains largely unknown. The functions of Dok-1 have now been investigated by the generation of two different COOH-terminal truncation mutants of this protein: one (DokPH+PTB) containing the pleckstrin homology and phosphotyrosine-binding domains, and the other (DokPH) composed only of the pleckstrin homology domain. Both of these mutant proteins were shown to act in a dominant negative manner. Overexpression of each of the mutants in highly metastatic B16F10 mouse melanoma cells thus both inhibited the tyrosine phosphorylation of endogenous Dok-1 induced by cell adhesion as well as reduced the association of the endogenous protein with cellular membranes and the cytoskeleton. Overexpression of DokPH+PTB in these cells also markedly reduced both the rates of cell spreading, migration, and growth as well as the extent of Ras activation. The effects of DokPH on these processes were less pronounced than were those of DokPH+PTB, indicating the importance of the phosphotyrosine-binding domain. These results suggest that at least in B16F10 cells, Dok-1 positively regulates not only cell spreading and migration but also cell growth and Ras activity.

Aspirin enhances the induction of type I allergic symptoms when combined with food and exercise in patients with food-dependent exercise-induced anaphylaxis

We examined the effect of aspirin as a substitute for exercise in inducing urticaria/anaphylaxis in three patients with food-dependent exercise-induced anaphylaxis (FDEIA). Two of the patients had specific IgE antibodies to wheat and the other had antibodies to shrimp. Administration of aspirin before ingestion of food allergens induced urticaria in one patient and urticaria and hypotension in another, while aspirin alone or food alone elicited no response. The third patient developed urticaria only when he took all three items, i.e. aspirin, food and additional exercise, whereas provocation with any one or or two of these did not induce any symptoms. These findings suggest that aspirin upregulates type I allergic responses to food in patients with FDEIA, and further shows that aspirin synergizes with exercise to provoke symptoms of FDEIA. This is the first report of a synergistic effect of aspirin in inducing urticaria/anaphylaxis, which was confirmed using challenge tests in patients with FDEIA.

Induction of interleukin-8 by Epstein-Barr virus latent membrane protein-1 and its correlation to angiogenesis in nasopharyngeal carcinoma

PURPOSE

The EBV latent membrane protein-1 (LMP-1) is a multifunctional protein. Recently, the contribution of LMP-1 to the metastasis of nasopharyngeal carcinoma (NPC) has been suggested. Angiogenesis is a key step for metastasis. Thus, the association of LMP-1 to neovascularization of NPC was examined in this study.

EXPERIMENTAL DESIGN

The association of LMP-1 to angiogenesis in 39 patients with NPC was evaluated by immunohistochemical study, and then induction of angiogenic factors by LMP-1 was examined by ELISA and luciferase reporter assay.

RESULTS

In an immunohistochemical study, the expression of LMP-1 was significantly correlated to microvessel counts (P = 0.0003), suggesting that LMP-1 may induce some angiogenic factors. Therefore, we studied the relationship between LMP-1 expression and interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) expression by immunohistochemical analysis. IL-8, VEGF, and bFGF expression were correlated to microvessel counts, but only IL-8 expression was significantly correlated to LMP-1 expression (P < 0.0001). Transfection with LMP-1 expression plasmid induced IL-8 protein expression in C33A cells. The expression of LMP-1 transactivated IL-8 promoter, as demonstrated by IL-8 promoter luciferase reporter assay. Mutation of the nuclear factor kappaB responsive element in the IL-8 promoter region completely abolished transactivation by LMP-1, whereas mutation of the activator protein responsive element did not affect promoter activity.

CONCLUSION

These results suggested that LMP-1 induces expression of IL-8 through the nuclear factor kappaB binding site, which may contribute in part to angiogenesis in NPC.

Induction of c-Met proto-oncogene by Epstein-Barr virus latent membrane protein-1 and the correlation with cervical lymph node metastasis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is distinctive in head and neck carcinomas for its close association with Epstein-Barr virus and its highly metastatic nature. Up-regulation of cell motility is essential for enhancement of metastatic potential. The expression of c-Met proto-oncogene, a high-affinity receptor for hepatocyte growth factor/scatter factor, has been reported to correlate with metastatic ability of the tumor cell. We observed close association of c-Met expression with cervical lymph node metastasis (P = 0.0272) in 39 NPC specimens studied immunohistochemically. Epstein-Barr virus-encoding latent membrane protein-1 (LMP-1) is a primary oncogene and is suggested to enhance the metastatic property of NPC. Previously, we reported that LMP-1 enhanced the motility of Madin-Darby canine kidney (MDCK) epithelial cells that was mediated by activation of Ets-1 transcription factor. Therefore, we examined the interrelationships of LMP-1, Ets-1, and c-Met. In immunohistochemical studies, the expression of LMP-1, Ets-1, and c-Met correlated significantly with each other in NPC (LMP-1 versus Ets-1, P < 0.0001; Ets-1 versus c-Met, P = 0.0012; LMP-1 versus Met, P = 0.0005). Transfection of LMP-1-expressing plasmid in MDCK cells induced c-Met protein expression. The c-Met protein was also induced by Ets-1 expression, and induction of c-Met by LMP-1 was suppressed by introducing a dominant-negative form of Ets-1 in LMP-1-expressing MDCK cells. These results suggest that LMP-1 induces c-Met through the activation of Ets-1, which may contribute in part to the highly metastatic potential of NPC.

Low-dose ultraviolet B radiation synergizes with TNF-alpha to induce apoptosis of keratinocytes

High-dose ultraviolet B (UVB) irradiation is known to induce apoptosis of keratinocytes, but low-dose UVB dose not. In this paper we present evidence that low-dose UVB can induce TNF-alpha-dependent apoptosis of keratinocytes. In our study, 5 mJ/cm(2) doses of UVB were not sufficient by themselves to induce apoptosis of cultured human keratinocytes, but 20 mJ/cm(2) doses of UVB were. The combination of 5 mJ/cm(2) doses of UVB and exogenous TNF-alpha (15 ng/ml) induced significant apoptosis of keratinocytes, although exogenous TNF-alpha without UVB did not. This phenomenon was accompanied by enhanced clustering of tumor necrosis factor receptor 1 (TNFR1). TNF-alpha's promotion of the induction of apoptosis by low-dose UVB was seen until 30 min after irradiation but not at 1 h. We confirmed this finding using a skin organ culture system. UVB (20 mJ/cm(2)), which did not induce transformation of epidermal keratinocytes into sunburn cells, induced apoptosis when TNF-alpha was added to the culture medium. These results suggest that one of the possible mechanisms of inducing keratinocyte apoptosis by low-dose UVB and TNF-alpha is that low-dose UVB augments ligand-binding-induced TNFR1 clustering, resulting in increased apoptotic cell death.

Improvement of solubility and oral bioavailability of rutin by complexation with 2-hydroxypropyl-beta-cyclodextrin

The object of this study was to enhance the solubility, dissolution rate, and oral bioavailability of rutin by complexation with 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD). The interaction of rutin with cyclodextrins (CyDs) was evaluated by the solubility, and ultraviolet (UV) and circular dichroism (CD) spectrophotometries. The chemical and enzymatic stability of rutin was examined in an alkaline buffer solution and in rat small intestinal homogenates, respectively. Dissolution rates of rutin and its CyD complexes were measured by the dispersed amount method. In vivo absorption studies of rutin after oral administration via conventional tablet containing rutin alone or its beta-CyD complexes was performed on beagle dogs. The stability constants calculated from the phase solubility method increased in the order of HP-gamma-CyD < G2-beta-CyD < beta-CyD < HP-beta-CyD. Spectroscopic studies also revealed that HP-beta-CyD and beta-CyD formed a relatively more stable inclusion complex with rutin. The dissolution rates of rutin increased by the complexation with CyDs in the order of rutin alone < HP-beta-CyD < or = beta-CyD. HP-beta-CyD inhibited the hydrolysis of rutin in the alkaline buffer solution and the small intestinal homogenates of rats, suggesting that HP-beta-CyD may stabilize rutin in a gastrointestinal tract after oral administration. When the tablet containing rutin or its beta-CyD complexes was administered to beagle dogs, the plasma levels of homovanillic acid (HVA) (a major stable metabolite of rutin) after oral administration of HP-beta-CyD complex were much higher than in either that of rutin alone or in its beta-CyD complex. The in vivo absorption study suggests that HP-beta-CyD increased the oral bioavailability of rutin from the gastrointestinal tracts of beagle dogs because of the increase in solubility, faster dissolution rate, and gastrointestinal stability. HP-beta-CyD has a significant advantage with respect to providing high aqueous solubility while maintaining a lack of toxicity in oral pharmaceutical preparations of rutin.

Antitumor effects on mouse melanoma elicited by local secretion of interleukin-12 and their enhancement by treatment with interleukin-18

To investigate the mechanism of the antitumor effect of locally secreted interleukin-12 (IL-12), we introduced the IL-12 p35 and p40 cDNAs into mouse B16 melanoma cells. IL-12 gene-transfected B16 melanoma (B16/IL12) showed marked retardation of tumor growth when implanted subcutaneously into syngeneic mice. In these mice, depletion of not only Natural Killer (NK) cells but also CD8+ T cells diminished the antitumor effect of locally secreted IL-12. Immunohistochemical analysis showed that NK cells and macrophages accumulated more densely at the center and periphery of B16/IL12 tumors than that of parental B16 tumors, whereas CD4+ T cells and CD8+ T cells accumulated sparsely only at the periphery of both transfected and untransfected tumors. Systemic treatment with interleukin-18 (IL-18) markedly inhibited the growth of B16/IL12 but did not influence the tumor growth of parental B16 cells in vivo. These results suggest that local IL-12 secretion can retard the growth of B16 melanoma mediated primarily by NK cells and indirectly by CD8+ T cells and that its antitumor effect is augmented by systemic treatment with the novel cytokine IL-18.

Syncope in patients with atrial flutter during treatment with class Ic antiarrhythmic drugs

We describe 2 atrial flutter (AFL) patients with syncope during treatment with class Ic antiarrhythmic drugs. During the syncope, 1:1 atrioventricular (AV) conduction during AFL preceded a wide QRS tachycardia. The class Ic drugs, flecainide and pilsicainide, slowed the atrial rate, resulting in AFL with 1:1 AV conduction, and the width of the QRS complexes became wider during the tachycardia. Syncope was abolished after successful radiofrequency catheter ablation of the AFL. These potential proarrhythmic effects of the class Ic drugs should be taken into account in AFL patients, and concomitant use of beta-blocking agents would be critical to prevent proarrhythmias.

Inducible expression of a CC chemokine liver- and activation-regulated chemokine (LARC)/macrophage inflammatory protein (MIP)-3 alpha/CCL20 by epidermal keratinocytes and its role in atopic dermatitis

Liver-and activation-regulated chemokine (LARC)/macrophage inflammatory protein (MIP)-3alpha/CCL20 is a CC chemokine which is constitutively expressed by follicle-associated epithelial cells in the mucosa, and attracts cells expressing CCR6 such as immature dendritic cells and alpha(4)beta(7)(high) intestine-seeking memory T cells. Here, we examine LARC/CCL20 expression in the skin. LARC/CCL20 mRNA and protein were induced in primary human keratinocytes upon stimulation with proinflammatory cytokines such as IL-1alpha and tumor necrosis factor (TNF)-alpha. In mice, intradermal injection of IL-1alpha and TNF-alpha rapidly induced a local accumulation of transcripts for LARC/CCL20 and its receptor CCR6 with a lag of several hours in the latter. In humans, immunostaining of LARC/CCL20 was weak if any in normal skin tissues but strongly augmented in lesional skin tissues with atopic dermatitis. Furthermore, massive infiltration of cells with markers such as CD1a, CD3 or HLA-DR was present in atopic skin lesions. Many infiltrating cells were also found to be CCR6(+) by a newly generated monoclonal anti-CCR6. However, Langerhans cells residing within the epidermis were hardly stained by anti-CCR6 in normal and atopic skin tissues. Furthermore, plasma levels of LARC/CCL20 were found to be elevated in patients with atopic dermatitis. Collectively, our results suggest that epidermal keratinocytes produce LARC/CCL20 upon stimulation with proinflammatory cytokines such as IL-1alpha and TNF-alpha, and attract CCR6-expressing immature dendritic cells and memory/effector T cells into the dermis of inflamed skin such as atopic dermatitis. LARC/CCL20 may not, however, play a major role in homeostatic migration of Langerhans cells into the skin.

Deficient Th1-type immune responses via impaired CD28 signaling in ultraviolet B-induced systemic immunosuppression and the restorative effect of IL-12

A single large dose (15 kJ/m(2)) of UVB-irradiation induces systemic immunosuppression and tolerance. We previously reported that IL-12 promotes the accessory cell function of epidermal Langerhans cells. In this study we have examined whether IL-12-pretreated antigen-presenting cells (APC) could restore the diminished T-cell response in mice irradiated with a single large dose of UVB. Spleen cells from UVB-irradiated mice showed reduced IFN-gamma production in a hapten-specific response but the function of APC in non-exposed skin of UVB-irradiated mice was not impaired. The pretreatment of APC with IL-12 did not restore the impaired IFN-gamma production by T cells from UVB-irradiated mice. Neither IL-10 nor TGF-beta was found to be involved in the suppression. Instead, we observed that anti-CD3 mAb-induced IFN-gamma production by T cells from UVB-irradiated mice was not augmented in the presence of anti-CD28 mAb, whereas IL-4 production was enhanced by the addition of anti-CD28 mAb. Furthermore, the reduced IFN-gamma production by T cells from UVB-irradiated mice in response to antigen plus APC could be restored by adding IL-12 to the culture. Our results thus indicate that UVB-induced systemic immunosuppression involves impaired Th1-type responses of T lymphocytes through CD28 stimulation, and that IL-12 compensates for the impaired CD28 costimulatory signaling in T cells resulting in the restoration of Th1-type responses.

Elimination of CD4(+) T cells enhances anti-tumor effect of locally secreted interleukin-12 on B16 mouse melanoma and induces vitiligo-like coat color alteration

CD4(+) T cells have been reported to suppress immunity against cancer in certain animal models. In this study, we investigated the role of CD4(+) T cells in the anti-tumor immune response when interleukin-12-producing melanoma cells are inoculated in mice. We found that interleukin-12-transfected B16 melanoma showed retarded tumor growth in syngeneic mice; however, all the mice developed tumors eventually. In vivo depletion of CD4(+) T cells led to complete regression of B16/interleukin-12 tumors in 12 of 20 mice (60%). Immunohistochemical analyses revealed that a number of CD8(+) T cells accumulated in close proximity to the B16/interleukin-12 tumors in the CD4(+) T cell-depleted mice, whereas CD8(+) T cells were only scarcely observed at the periphery of the tumors in control immunocompetent mice. Furthermore, 10 of 20 mice treated with both B16/interleukin-12 inoculation and CD4(+) T cell depletion exhibited vitiligo-like coat color alteration. B16/interleukin-12 tumors completely regressed in all the mice with vitiligo. Histologic examination showed that CD8(+) lymphocytes accumulated around the hair bulbs of mice with vitiligo, but not in those without vitiligo. These results suggest that CD4(+) T cells have an inhibitory effect on tumor rejection by suppressing cytotoxic CD8(+) T cells in this melanoma loading model with local interleukin-12 secretion. To investigate the mechanism of enhanced anti-tumor effects by CD4(+) T cell depletion, we examined the T helper type 1/2 cytokine profile in the tumor draining lymph nodes of B16/interleukin-12-bearing mice with or without CD4(+) T cell depletion using the reverse transcription-polymerase chain reaction method. We found that CD4(+) T cell depletion eliminated T helper type 2 cells and resulted in a T helper type 1-dominant cytokine profile in tumor draining lymph nodes. We emphasize that this T helper type 1-dominant cytokine profile may generate further activated CD8(+) T cells against B16 melanoma cells, lead B16/interleukin-12 to regress, and result in the destruction of the melanocytes in hair bulbs due to cross-antigenicity between both cell types. This mouse model not only demonstrates the depletion of CD4(+) T cells as a useful strategy for cancer gene therapy with interleukin-12 but also provides a model for human melanoma-associated vitiligo.J Invest Dermatol 115:1059-1064 2000

Diagnostic significance of the morphological change in the atrial electrogram during Para-Hisian pacing

Para-Hisian pacing (PHP), a pacing method to differentiate between conduction occurring over an accessory pathway (AP) from that over the atrioventricular node (AVN), is assessed essentially by comparing the timing in the atrial electrogams. Morphological change in the atrial electrograms is often observed during PHP, but its significance has not been investigated. Prior to the catheter ablation procedure, PHP was performed in 52 patients with an AP and in 36 patients with AV nodal reentrant tachycardia (AVNRT). The morphological change in the atrial electrograms, which was retrospectively assessed between the His bundle and proximal right bundle branch (HB-RB) captured and non-captured beats, was identified in 15 of 52 patients with an AP and in 26 of 36 patients with AVNRT. The atrial electrogram in the 6 of these 15 AP patients changed its morphology without overlapping the ventricular electrogram. All 6 AP patients exhibited a PHP pattern with the presence of 2 retrograde conduction routes, an AP and the AVN. In the patients demonstrating no morphological change in the atrial electrogram, 33 of 37 AP patients and all 10 AVNRT patients had only one retrograde conduction route. Morphological change in the atrial electrogram without overlapping the ventricular electrogram seems to have diagnostic significance indicating the presence of both AP and AVN conduction.

An efficient synthesis of 5-bromo-2-methoxy-6-methylaminopyridine-3carboxylic acid

An efficient synthesis of 5-bromo-2-methoxy-6-methylaminopyridine-3-carboxylic acid (1), a carboxylic acid moiety of a potent dopamine D2 and D3 and serotonin-3 (5-HT3) receptors antagonist, (R)-5-bromo-N-(1-ethyl-4-methylhexahydro-1 ,4-diazepin-6-yl)-2-methoxy-6-methylaminopyridine-3-carboxamide, is described. Reaction of methyl 2,6-difluoropyridine-3-carboxylate (12) with methylamine in EtOH at -25 degrees C gave a mixture of methyl 2-fluoro-6-methylaminopyridine-3-carboxylate (13) and the regioisomer 14 in a ratio of 57 : 43. On the other hand, reaction of 12 and methyl 2,6-dichloropyridine-3-carboxylate (16) with sodium methoxide in tetrahydrofuran (THF) and CH2Cl2 provided the 2-methoxypyridine-3-carboxylic esters 20 and 23, respectively, as main products. Similar reaction of 16 in N,N-dimethylformamide (DMF) and MeOH proved to be highly regioselective for the 6-position. A much greater regioselectivity for substitution at the 6-position (>97%) was observed when 16 was treated with 4-methylbenzenethiolate anion in DMF (quantitative yield). After methoxylation of methyl 2-chloro-6-(4-methylbenzenethio)pyridine-3-carboxylate (25b) and successive oxidation of the 6-benzenethio moiety, nucleophilic substitution of the sulfoxide derivative 28 with methylamine gave the 6-methylamino derivative 8. Finally, bromination of 8 and alkaline hydrolysis produced the desired product 1 in an overall yield of 67%.

[A study of food-dependent exercise-induced anaphylaxis by analyzing the Japanese cases reported in the literature]

We surveyed and analyzed cases of food-dependent exercise-induced anaphylaxis (FDEIA) in the Japanese literature. We found 167 cases which were reported as FDEIA since 1983. Analyzing these case, following characteristic features were revealed: 1) Recent upward trend in the number of reports of FDEIA was noted. 2) Male cases were more frequent than female cases, while about half of the cases were teenager. 3) More than half of the cases were proved to be induced by wheat followed by shrimp. In those under 20, shrimp was the most popular cause rather than wheat. 4) Skin test and/or IgE RAST showed positive results in most cases, suggesting that the response itself is linked to type I allergic reaction. 5) About 40% of the patients had history of atopic disease, indicating that atopic condition may play some role in FDEIA. 6) All cases who performed provocation test with aspirin responded to food challenge and/or exercise in combination with aspirin. This indicates that aspirin plays a key provoking factor in FDEIA. 7) In 17 cases FDEIA attacks were observed during noon recess or physical education class after lunch at school. We stress here the importance of a nation-wide education to school teachers the potential danger of this disorder.

Small Gtpase rab3A is associated with melanosomes in melanoma cells

Rab3A is a small guanosine triphosphate (GTP)-binding protein that has been recently implicated in intracellular vesicle transport and the secretion of neurotransmitters in neuronal cells. We demonstrate here that Rab3A is associated with melanosomes in pigment cells. Rab3A as well as Rabphilin3A, a putative target protein of Rab3A, were detected in the melanosome fraction, purified from B16 murine melanoma cells by sucrose density gradient ultracentrifugation. In contrast, Rab GDP dissociation inhibitor (GDI), a GDP/GTP exchange protein for Rab3A, was found in the cytosol fraction. Further studies using confocal laser scanning microscopy and immunoelectron microscopy revealed that immunoreactive Rab3A is localized in conjunction with the melanosomal membrane. These results suggest the possibility of involvement of Rab3A-Rabphilin3A complex, regulated by Rab GDI, in the intracellular transport of melanosomes in pigment cells.

Heterozygous HPS1 mutations in a case of Hermansky-Pudlak syndrome with giant melanosomes

We report a Japanese man with Hermansky-Pudlak syndrome, having oculocutaneous albinism with a bleeding diathesis. Gene analysis of the patient's peripheral blood cells revealed that he was a compound heterozygote for HPS1 gene mutations. One of the mutations was a novel frameshift mutation at codon 321 (a G insertion) in exon 11 ( approximately 962-963insG), and the other was a 5' splice-junction mutation of IVS5 (IVS5 + 5G-->A). The content of eumelanin in the patient's hairs was significantly reduced. Histological analysis using light and electron microscopy revealed that melanocytes in the patient's epidermis contained an appreciable number of giant melanosomes. Cultured melanocytes from the patient's skin also contained giant melanosomes. Our finding of mutations in the HPS1 gene in relation to abnormalities in melanosome morphology and melanin production shed light on the role and function of the HPS1 gene product in the synthesis of melanosomes and melanin pigment.

Association of latent membrane protein 1 and matrix metalloproteinase 9 with metastasis in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a highly metastatic carcinoma whose consistent association with Epstein-Barr virus (EBV) has been established. Latent membrane protein 1 (LMP1), an EBV membrane protein expressed in latent infection, is considered to be the EBV oncoprotein. Matrix metalloproteinase 9 (MMP9), one of the MMP families, degrades Type IV collagen, a major component of extracellular matrix and is believed to be crucial for cancer invasion and metastasis. Although MMP9 is reported to be expressed in a variety of cancers, no reports concerning NPC have been published to date to the authors' knowledge. Recently, the authors have shown that LMP1 induces MMP9 in vitro cell line, which suggests the possibility of a mechanism in which LMP1 of EBV contributes to the metastasis and tumorigenesis of NPC by the induction of MMP9.

METHODS

The expressions of LMP1 and MMP9 were immunohistochemically examined in 38 NPC sections, and the relation of these proteins were statistically analyzed. The authors also analyzed the associations of these proteins with clinical features.

RESULTS

Both LMP1 and MMP9 proteins were predominantly immunolocalized in cancer nests. The expression of MMP9 showed a significant positive correlation with the expression of LMP1 (r = 0.75; P < 0.0001). Also, the expression of MMP9 correlated with lymph node metastasis (P = 0. 0004).

CONCLUSIONS

The results suggest that the induction of MMP9 by LMP1 contributes to the metastatic potential of NPC.

Mercury-induced nummular dermatitis

We report 2 cases of relapsing nummular dermatitis according to mercury sensitivity, which was confirmed by patch testing. Removal of the amalgam from dental metal alloys markedly improved their skin eruptions. One of the patients, a dentist, experienced exacerbation of the eruptions on his lower legs after handling dental amalgam. Hypersensitivity to haptens such as metals is possibly involved in, at least in some patients, the pathogenesis of nummular dermatitis.

Transformation of Madin-Darby canine kidney (MDCK) epithelial cells by Epstein-Barr virus latent membrane protein 1 (LMP1) induces expression of Ets1 and invasive growth

The Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) has a significant role in initiating EBV-associated lymphoproliferative disease and EBV-related malignancies. In view of clinical features related to the type of EBV latency, LMP1 may influence invasiveness of EBV associated tumors categorized as types II and III as represented on nasopharyngeal carcinoma (NPC). To screen for genes associated with invasion of epithelial cells transformed by LMP1, Madin-Darby canine kidney (MDCK) epithelial cells were transformed by LMP1. Stable transfection of a LMP1 gene into MDCK cells induced morphological change from cobblestone to a long spindle-shape, reduced cell-cell adhesion and caused high cell motility. Parental MDCK cells, which form spherical cysts in three-dimensional collagen gel matrix, form branching tubules following exposure to hepatocyte growth factor (HGF). MDCK cells transformed by LMP1 showed invasive growth to form branching tubules into collagen gel without HGF-treatment. mRNA differential display and Northern hybridization identified plasminogen activator inhibitor-1 (PAI-1), urokinase type plasminogen activator (uPA) and ets1 as genes upregulated during transformation by LMP1. Expression of a dominant negative type of Etsl in LMP1-transformed cells downregulated uPA expression and cell motility. Deletion of LMP1 cytoplasmic carboxy-terminal activating region 1 (CTAR1) domain abolished transformation, but a deletion mutant lacking CTAR2 domain still retained transforming and uPA-inducing ability. Expression of Ets1 was immunolocalized in tumor cells of NPC tissue which frequently express LMP1. Taken together, it is suggested that LMP1 induces expression of Ets1 which may contribute to invasion of NPC by stimulating cell motility and uPA expression.

Demonstration of phase-3 and phase-4 retrograde block in a second concealed accessory pathway after an initial successful radiofrequency ablation of a 'normal' concealed accessory pathway

We report a patient with concealed Wolff-Parkinson-White syndrome who, following catheter ablation, demonstrated phase-3 and phase-4 retrograde block in a concealed accessory pathway. After an initial 'apparently successful' ablation, retrograde conduction was through the atrioventricular node during constant ventricular pacing. Ventricular extrastimulus testing was performed at a basic drive cycle length of 600 ms. Unexpectedly, ventricular extrastimuli at coupling intervals of 440-380 ms were conducted retrogradely over an accessory pathway, consistent with a phase-3 and phase-4 retrograde block in the accessory pathway. Residual accessory pathway conduction was eliminated in a single ablation session.

Roles for the protein tyrosine phosphatase SHP-2 in cytoskeletal organization, cell adhesion and cell migration revealed by overexpression of a dominant negative mutant

SHP-2, a SRC homology 2 domain-containing protein tyrosine phosphatase, mediates activation of Ras and mitogen-activated protein kinase by various mitogens and cell adhesion. Inhibition of endogenous SHP-2 by overexpression of a catalytically inactive (dominant negative) mutant in Chinese hamster ovary cells or Rat-1 fibroblasts has now been shown to induce a marked change in cell morphology (from elongated to less polarized) that is accompanied by substantial increases in the numbers of actin stress fibers and focal adhesion contacts. Overexpression of the SHP-2 mutant also increased the strength of cell-substratum adhesion and resulted in hyperphosphorylation of SHPS-1, a substrate of SHP-2 that contributes to cell adhesion-induced signaling. Inhibition of SHP-2 also markedly increased the rate of cell attachment to and cell spreading on extracellular matrix proteins such as fibronectin and vitronectin, effects that were accompanied by enhancement of adhesion-induced tyrosine phosphorylation of paxillin and p130Cas. In addition, cell migration mediated by fibronectin or vitronectin, but not that induced by insulin, was impaired by overexpression of the SHP-2 mutant. These results suggest that SHP-2 plays an important role in the control of cell shape by contributing to cytoskeletal organization, and that it is an important regulator of integrin-mediated cell adhesion, spreading, and migration as well as of tyrosine phosphorylation of focal adhesion contact-associated proteins.