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.

Slow-fast form of atrioventricular nodal reentrant tachycardia with eccentric retrograde left-sided activation

A case of atypical AV nodal reentrant tachycardia (AVNRT) with eccentric retrograde left-sided activation, masquerading as tachycardia using a left-sided accessory pathway, is reported. Initially, it appeared that the tachycardia was a typical slow-fast form of AVNRT. The earliest retrograde activation, however, was registered at a site approximately 3 cm from the coronary sinus orifice (left atrial free wall), indicating atypical AVNRT. Atrial tachycardia and orthodromic AV reciprocating tachycardia using an accessory AV pathway were excluded. Slow pathway ablation at the posteroseptal right atrium eliminated the tachycardia. It was suggested that the anterograde limb of the tachycardia circuit was a slow AV nodal pathway with typical posteroseptal location, whereas the retrograde limb was a long atrionodal pathway connecting the compact AV node and the left atrial free wall near the mid-coronary sinus.

[Role of Candida allergen in atopic dermatitis and efficacy of oral therapy with various antifungal agents]

We studied whether fungal allergens play a role in exacerbating the clinical symptoms of atopic dermatitis (AD). We found that the percentage of the patients who showed CAP-RAST positive (2 < or = score) to Candida albicans (Ca) was significantly higher in the patients with severe symptoms and high serum IgE level than those with mild symptoms and lower IgE. This was also true for the patients with CAP-RAST positive to Pityrosporum ovale (Po). AD patients with their symptoms localized to head and neck showed significantly higher tendency to have positive CAP-RAST (2 < or = score) to Ca and Po when compared to those with their eruption distributing to the extremities. We then evaluated the efficacy of oral therapy with antifungal agents in 140 cases of refractory AD with positive CAP-RAST to Ca. Good or excellent response was obtained in 60% with fluconazole, 35% with itraconazole, 31% with amphotericin B, 28% with nystatin. The present finding that amphotericin B and nystatin, both of which are not absorbed through intestine, were effective for approximately a third of the patients indicates that Ca in the intestine plays an important role in triggering AD symptoms. Fluconazole was more effective than amphotericin B and nystatin, suggesting that fungal colonizing in other parts of the body but the digestive tract also play a role in the exacerbation of AD symptoms.

Effect of stress on atopic dermatitis: investigation in patients after the great hanshin earthquake

BACKGROUND

Although a variety of factors are responsible for atopic dermatitis (AD), very little is known about the effect of stress caused by a natural disaster on AD symptoms.

OBJECTIVE

This study was conducted to assess the effect of stress or trauma on the symptoms of AD.

METHODS

One thousand four hundred fifty-seven patients with AD (745 males and 712 females), diagnosed by using the criteria of the Japanese Dermatology Association, were enrolled in the study. The data were obtained from a self-administered questionnaire given to patients with AD after experiencing the Great Hanshin Earthquake. The data were analyzed by multivariate logistic regression analysis. Patients were divided into 3 groups: area A, severe damage to buildings and houses; area B, mild damage; and control area, no damage.

RESULTS

Exacerbation of skin symptoms was found in 38% and 34% of patients in areas A and B, respectively, whereas similar exacerbation was seen in 7% of control patients. Nine percent and 5% of the patients in areas A and B, respectively, showed improvement in their symptoms compared with 1% in the control group. The earthquake caused stress in 63% and 48% of the patients in areas A and B, respectively, but fewer patients felt stress in undamaged areas (19%). Multiple logistic regression analysis revealed that of the factors examined here, subjective distress is the factor that is most responsible for the exacerbation of skin symptoms (odds ratio, 2.98; 95% confidence interval, 2.25-3.96).

CONCLUSION

The results presented here strongly suggest that stress caused by a natural disaster influences AD symptoms.

Horizontal and vertical pigment spread into surrounding piebald epidermis and hair follicles after suction blister epidermal grafting

Following the earlier description of Carnot and Deflandre in 1896, pigment spread phenomenon in mammals was investigated using immunogenetically marked melanocytes (Billingham and Silver, Quart. Rev. Biol. 1960 35: 1-40; Billingham and Silver, Ann. N.Y. Acad. Sci. 1963 100: 348-363). In spite of a number of similar studies on vitiligo lesions, detailed evaluation of pigment spread in piebald lesions has not been reported. To gain further insight into the pigment spread phenomenon in human skin, five piebald patients were studied, on whom suction blister epidermal grafting therapy onto piebald patches was performed. In the present study, pigmentation of all epidermal grafts from normally pigmented areas spread horizontally. It was also found that pre-existing white hairs in recipient sites became pigmented within 1 year after epidermal grafting. Immunofluorescence studies using melanocyte-specific antibody NKI/beteb revealed the newly induced presence of melanocytes in the newly pigmented hair follicles. Further, to study the possible mechanisms inhibiting melanocyte migration from normal skin into piebald lesions, epidermis was grafted from border zones (containing both normal and piebald skin) into the center of hypopigmented lesions. Melanocytes clearly migrated through the border zone of grafted epidermis into surrounding recipient hypopigmented sites.

Leiomyosarcoma of the larynx

Tumours of smooth muscle origin are extremely rare in the upper aerodigestive tract. Immunohistochemical studies are helpful for accurate diagnosis of leiomyosarcoma. Here, we report a case of well-differentiated laryngeal leiomyosarcoma that showed rapid local growth but no metastasis. Diagnosis and treatment of leiomyosarcoma are discussed.

Intermittent bundle branch blocks in a patient with uncommon-type atrioventricular nodal reentrant tachycardia and enhanced atrioventricular nodal conduction

We report on a patient with uncommon-type atrioventricular (AV) nodal reentrant tachycardia with a short tachycardia cycle length (235-270 ms), in whom transient wide QRS tachycardia with both left bundle branch block and right bundle branch block aberrancy were followed by narrow QRS complexes. In addition, His-ventricular (H-V) block and a sudden prolongation of the H-V interval occurred during the tachycardia. As the determinant of these unusual findings, the possibility that the anterograde limb of the reentry circuit has an enhanced AV nodal conduction property is discussed, as is the clinical significance of this type of tachycardia.

IL-12 promotes the accessory cell function of epidermal Langerhans cells

The objective of this study was to investigate the effects of cytokines regulating cutaneous immune responses, on the accessory cell function of epidermal cells (EC). EC were treated with various cytokines, and the accessory cell function of the cytokine-pretreated EC was examined by the allogeneic mixed epidermal cell-lymphocyte reaction (MECLR). Among the cytokines examined, IFN-gamma- and IL-12-pretreated EC augmented IFN-gamma production in the MECLR, while none of the other cytokines was effective. However, the cytokine-pretreated EC did neither affect T cell proliferation nor IL-4 production in the MECLR. Next we attempted to analyze the mechanisms by which IL-12-pretreated EC increase IFN-gamma production in the MECLR. Endogenous IFN-gamma produced during the IL-12 pretreatment of EC was found to play only a minor role in modulating the function of EC. The expression of MHC class II, CD80 and CD86 on EC was not affected by IL-12. On the other hand, soluble mediators that induce IFN-gamma production during the MECLR containing IL-12-pretreated EC were identified as endogenously produced IL-12 (the major mediator) and IL-18 (the minor mediator). Furthermore, the results of depletion experiments indicate that IL-12 promotes the accessory cell function of Langerhans cells to responder T cells in inducing IFN-gamma production in the MECLR.

Induction chemoradiotherapy for advanced stage III non-small cell lung cancer: long-term follow-up in 42 patients

This multi-institutional phase II study was designed to assess the feasibility, efficacy, toxicity, and long-term survival of induction chemoradiotherapy followed by surgery in previously untreated patients with advanced stage III non-small cell lung cancer. Chemotherapy regimen included cisplatin 20 mg/m2 on days 1-5 and 29-33, and VP-16 40 mg/m2 on days 1-5 and 29-33. Radiotherapy (50 Gy in 25 fractions) began on day 1. Clinically downstaged patients underwent thoracotomy 3-5 weeks after the completion of radiotherapy. Forty-two eligible patients (ten stage IIIA and 32 IIIB) were followed for a median period of 64 months. The response rate was 81%, and 20 patients had a clinically good response. Twenty-one patients underwent thoracotomy. Nineteen patients had complete resections and there were seven pathologic complete responses. There were four treatment related deaths (all stage IIIBs). There were significant survival differences between stage IIIA versus IIIB patients (P = 0.028; median survivals, 24.9 vs. 11.1 months; 5-year survival rates, 20% vs. 8.3%), and patients that achieved pathologic complete response (CR) versus those that did not (P = 0.045; median survivals 30.1 vs. 11.1 months; 5-year survival rates, 28.6% vs. 8.3%). Although the induction chemoradiotherapy employed in this study was not appropriate for stage IIIB patients, it proved feasible in stage IIIA patients in whom it resulted in good 5-year survival rates. It also provided good survival rates in patients achieving pathologic CR.

Tissue distribution of a melanoma-associated antigen D-1 immunogenic in patients with melanoma

A human melanoma-associated antigen D-1 was recently identified by screening an expression cDNA library derived from mRNA of cultured melanoma cells with sera of melanoma patients. The aim of this study is to present in vivo expression and precise distribution of D-1 in normal tissues and benign or malignant neoplasms. By in situ hybridization, we found that the D-1 mRNA was exclusively expressed in the cytoplasms of melanoma cells, but not in keratinocytes, fibroblasts and lymphocytes adjacent to melanoma nests. Further immunohistochemical studies revealed that the expression of D-1 antigen was distributed to both the surface and cytoplasm of melanoma cells, indicating that D-1 antigen can be recognized by killer T lymphocytes or antibodies in vivo. No significant mRNA nor peptide of D-1 was detected in basal cell carcinoma, squamous cell carcinoma and other benign tumors such as melanocytic nevi and seborrheic keratosis. We also confirmed that D-1 mRNA and peptide were not expressed in normal organs by dot blot hybridization and western blot analysis, respectively. These results will assess the suitability of recombinant D-1 protein to implement active specific immunotherapy against melanoma.

Estimation of organ cumulated activities and absorbed doses on intakes of several 11C labelled radiopharmaceuticals from external measurement with thermoluminescent dosimeters

We have developed a method for obtaining the cumulated activities in organs from radionuclides, which are injected into the patient in nuclear medicine procedures, by external exposure measurement with thermoluminescent dosimeters (TLDs) which are attached to the patient's body surface close to source organs to obtain information on body-surface doses. As the surface dose is connected to the cumulated activities in source organs through radiation transmission in the human body which can be estimated with the aid of a mathematical phantom, the organ cumulated activities can be obtained by the inverse transform method. The accuracy of this method was investigated by using a water phantom in which several gamma-ray volume sources of known activity were placed to simulate source organs. We then estimated by external measurements the organ cumulated activities and absorbed doses in subjects to whom the radiopharmaceuticals 11C-labelled Doxepin, 11C-labelled YM09151-2 and 11C-labelled Benzotropin were administered in clinical nuclear medicine procedures. The cumulated activities in the brain obtained with TLDs for Doxepin and YM09151-2 are 63.6 +/- 6.2 and 32.1 +/- 12.0 kBq h MBq-1 respectively, which are compared with the respective values of 33.3 +/- 9.9 and 23.9 +/- 6.2 kBq h MBq-1 with direct PET (positron emission tomography) measurements. The agreement between the two methods is within a factor of two. The effective doses of Doxepin, YM09151-2 and Benzotropin are determined as 6.92 x 10(-3), 7.08 x 10(-3) and 7.65 x 10(-3) mSv MBq-1 respectively with the TLD method. This method has great advantages, in that cumulated activities in several organs can be obtained easily with a single procedure, and the measurements of body surface doses are performed simultaneously with the nuclear medicine procedure, as TLDs are too small to interfere with other medical measurements.

Repeated interferon-alpha administration inhibits dopaminergic neural activity in the mouse brain

In vivo effects of single and repeated interferon-alpha administrations on the dynamics of noradrenaline, dopamine and 5-hydroxytryptamine were investigated in the mouse brain. Single interferon-alpha administration (15, 30 and 60 X 10(6) U/kg i.p.) had no significant effect on the levels of monoamines and their metabolites or monoamine turnover. When interferon-alpha (15 X 10(6) U/kg i.p.) was administered once a day for 5 days, however, both dopamine and 3,4-dihydroxyphenylacetic acid levels were significantly decreased and alpha-methyl-p-tyrosine-induced dopamine depletion was significantly suppressed. These results suggest that repeated interferon-alpha administration inhibits dopaminergic neural activity. This inhibitory action of interferon-alpha in dopamine neurons may be involved in adverse central effects, such as parkinsonism and depression with suicidal potential.

Potential efficacy of low metal diets and dental metal elimination in the management of atopic dermatitis: an open clinical study

We performed an open clinical study on the effects of low metal diets and/or dental metal elimination on 27 patients with moderate to severe atopic dermatitis (AD), who showed positive patch tests for metal allergens and/or clinical exacerbation by oral provocation tests with metal salts. All the patients were recommended to ingest low metal diets for 3 months and/or undergo dental metal elimination. Marked or moderate improvement was noted in 18 patients (67%); 7 patients (26%) showed marked improvement and 11 patients (41%), moderate improvement. Nine patients (33%) showed minimal improvement or no change. In the patients who showed marked or moderate improvement, we observed statistically significant decreases (p < 0.05) in both peripheral blood eosinophil counts and serum LDH levels after 3 months of treatment. The present study suggests that restriction of ingested metal allergens to which patients have positive patch tests and/or oral challenge tests may be useful in the management of some patients with AD who have metal sensitivity.

Expression of E and P-cadherin by melanoma cells decreases in progressive melanomas and following ultraviolet radiation

The purpose of our study was to determine whether the degree of E- and P-cadherin expression in melanomas correlates with the invasive behavior of the clinical lesions from which the cell lines were derived. Cadherins comprise a family of calcium-dependent cellular adhesion molecules expressed on most cell types that form solid tissues. In the human epidermis, melanocyte cadherin expression may function to maintain the integrity of the epidermal-melanin unit. Employing both immunofluorescence microscopy and fluorescence-activated cell sorter analysis, we localized and quantitated E- and P-cadherin expression on melanoma cell lines derived from primary or metastatic lesions using the monoclonal antibodies HECD-1 and NNC-CAD-299, respectively. Human epidermal melanocytes isolated from neonatal foreskin were evaluated by similar techniques and served as a biologic control. Melanoma cell lines were isolated from primary or metastatic lesions of patients described as having "early," "intermediate," or "advanced disease." Melanoma E- and P-cadherin immunofluorescence, as quantified by fluorescence-activated cell sorter, varied inversely with disease progression. Selected log mean ratios of E-cadherin fluorescence, as compared to human epidermal melanocytes (arbitrarily = 1), ranged from 1.04 in the WM 35 melanoma cell line (low invasive potential) to 0.1 and 0.02 in the WM 983A and 1361A melanoma cell lines (derived from primary lesions with metastases), respectively. Although values for P-cadherin fluorescence were less, the trend of decreasing cadherin amounts with more advanced disease was observed. Melanoma cells appear to express E- and P-cadherin levels inversely related to disease progression. Ultraviolet radiation significantly decreased E- and P-cadherin expression in the human epidermal melanocytes and P-cadherin expression in the WM 35 melanoma cell line (p < 0.05). Although not statistically significant, E-cadherin expression in the WM 35 melanoma cell line decreased substantially. Thus, ultraviolet radiation may have a direct effect on human epidermal melanocytes and melanoma cell attachment through cadherins within the epidermis or tumor nodules.

Deletion of specific protein kinase C subspecies in human melanoma cells

It has been shown that tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), stimulates the proliferation of normal human melanocytes, whereas it inhibits the growth of human melanoma cell lines. The expression of protein kinase C (PKC) subspecies, the major intracellular receptors for TPA, was examined in normal melanocytes and the four melanoma cell lines HM3KO, MeWo, HMV-1, and G361. PKC was partially purified and then separated into subspecies by column chromatography on Mono Q and hydroxyapatite successively, and finally subjected to immunoblot analysis using antibodies specific for the PKC subspecies. Of the PKC subspecies examined, delta-, epsilon-, and zeta-PKC were detected in both normal melanocytes and the four melanoma cell lines. In contrast, both alpha-PKC and beta-PKC were expressed in normal melanocytes, whereas either alpha-PKC or beta-PKC was detected in melanoma cells. Specifically, HM3KO, MeWo, and HMV-1 cells were shown to contain alpha-PKC but not beta-PKC, while G361 cells expressed beta-PKC but not alpha-PKC. The growth of these melanoma cells was suppressed by TPA treatment, and the growth of the G361 cells lacking alpha-PKC was inhibited more efficiently than the other melanoma cell lines which lacked beta-PKC. It was further shown that beta-PKC was not detected in freshly isolated human primary or metastatic melanoma tissues. These results suggest that the expression of alpha-PKC or beta-PKC may be altered during the malignant transformation of normal melanocytes and that loss of alpha-PKC or beta-PKC may be related to the inhibitory effect of TPA on the growth of melanoma cells.

Effective elimination of fibroblasts in cultures of melanocytes by lowering calcium concentration in TPA depleted medium following geneticin treatment

Melanocytes grow well in culture media supplemented with phorbol ester. However, phorbol ester is metabolically stable and has prolonged effects on multiple cellular responses. Different groups have reported that they could cultivate melanocytes without phorbol ester. However, in medium without phorbol esters contaminating fibroblasts are often difficult to eliminate. We have developed an improved method of eliminating fibroblasts using geneticin in serum free medium with bFGF, endothelin-1 and no phorbol ester. Treatment with a low concentration of geneticin effectively eliminated contaminating fibroblasts and was not harmful to melanocytes if geneticin was added initially in a high calcium media (2 mM) followed by a change to a low (0.09 mM) calcium media immediately after removal of the geneticin. With this technique we could easily establish pure melanocyte culture. This culture method will provide a useful tool for studies on melanocyte cellular response without the influence of phorbol ester.

Long-term neuroleptic treatments counteract dopamine D2 agonist inhibition of adenylate cyclase but do not affect pertussis toxin ADP-ribosylation in the rat brain

We have investigated the response of adenylate cyclase to GTP and to dopamine (DA) in striatal membranes of rats treated for 3 weeks with chlorpromazine or haloperidol, and further measured the level of Gi (an inhibitory GTP-binding protein) or Go (a similar GTP-binding protein of unknown function) in 3 areas (cerebral cortex, striatum and hippocampus) utilizing pertussis toxin-catalyzed ADP ribosylation. In saline-treated control membranes, GTP exerted a biphasic effect on basal and DA-stimulated enzyme activity--peak levels of stimulation by DA plus GTP were observed at 1 microM GTP. Conversely, dopaminergic inhibitory effects at 10-100 microM GTP were completely attenuated in chlorpromazine or haloperidol-treated membranes. D2 inhibition of adenylate cyclase by the selective D2 agonist PPHT was also attenuated due to these neuroleptic treatments, while an increase in D2 receptor binding was observed. The pertussis toxin ADP-ribosylation of G-proteins (Gi/Go) did not differ significantly in any area. This indicates that long-term neuroleptic treatments increased D2 receptor binding, but attenuated D2 inhibition of adenylate cyclase, and exercised no influence on pertussis toxin ADP-ribosylation.

DOPA-negative melanocytes in the outer root sheath of human hair follicles express premelanosomal antigens but not a melanosomal antigen or the melanosome-associated glycoproteins tyrosinase, TRP-1, and TRP-2

It is believed that DOPA-negative melanocytes in the outer root sheath of the human hair follicle are activated, become identifiable by DOPA staining, and migrate into the epidermis during the repigmenting phase of vitiligo. These cells are difficult to identify, however, and otherwise have not been characterized. These cells are readily identified by immunofluorescence, immunohistochemistry, and immunoelectronmicroscopy using the antibodies NKI/beteb and A4F11, which recognize premelanosome-related antigens. The majority of the outer root sheath melanocytes were found in the mid to the upper portion of the hair follicle. Double staining revealed that these cells were distinct from HLA-DR-bearing dendritic cells. Further immunohistochemical investigation using alpha-PEP-7, alpha-PEP-1, or TMH-1 and alpha-PEP-8 antibodies revealed that outer root sheath melanocytes cannot be identified by antibodies to tyrosinase, TRP-1, or TRP-2, respectively. These cells also did not react with HMB45 antibody, which recognizes a melanosome-associated cytoplasmic antigen. We believe that the inactive outer root sheath melanocytes contain some of the early structural proteins but not any of the enzymatic proteins necessary for melanogenesis. Therefore, activation is the process whereby outer root sheath melanocytes acquire all of the structural and enzymatic proteins necessary for melanogenesis.

[Examination of toxin production from environmental Bacillus cereus and Bacillus thuringiensis]

Emetic toxin- and entero toxin-producing activities were examined for 524 strains of Bacillus cereus and 90 strains of Bacillus thuringiensis to determine the distribution and contamination in natural environment, including foods, vegetable, soil and etc. Emetic toxin was assayed by the production of acid from HEp-2 cells induced by the culture supernatants of Bacillus, which was developed as an improved method for the detection of B. cereus heat-stable emetic-toxin by us. In the 524 strains of B. cereus tested, 11 out of 60 strains obtained from bean paste and 5 out of 20 strains obtained from peach produced emetic toxin which was detected by the HEp-2 cell method. All these emetic toxin-producing isolate strains were classified into H1 serotype. The 90 strains of B. thuringiensis did not produce emetic toxin, but the 47 strains produced entero toxin.