Effect of carvedilol on atrioventricular conduction in the ischemic heart

We compared the effects of carvedilol on atrial-His and His-ventricular conduction with those of propranolol in isolated rat hearts. Hearts were perfused retrograde, and atrial-His and His-ventricular intervals were measured. The effective doses that increased conduction times by 25% were 10(-6) M for atrial-His and 3x10(-6) M for His-ventricular for propranolol, and 8x10(-8) M for atrial-His and 10(-8) M for His-ventricular for carvedilol. Prazosin did not affect the atrial-His and His-ventricular intervals. After ischemia-reperfusion, atrial-His and His-ventricular intervals increased to a greater extent with 10(-6) M carvedilol. To determine the direct membrane effect, we examined the transmembrane action potential in guinea pig papillary muscle. Both drugs decreased the maximum upstroke velocity equally. Our data indicate that carvedilol had a greater effect on atrioventricular conduction in the setting of ischemia-reperfusion than did propranolol. This effect of carvedilol was not due to its alpha-adrenoceptor blocking property or to a direct membrane effect.

DNA-dependent protein kinase catalytic subunit is cleaved during UV-induced apoptosis

Ultraviolet radiation can induce the injury of epidermal keratinocytes, resulting in sunburn cell (apoptotic cell) formation. It has been demonstrated that the protease caspase-3, a downstream molecule of the CD95 pathway, is activated in UV-exposed HaCaT cells, and that the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is cleaved by interleukin-1beta converting enzyme (ICE)-like protease during apoptosis induced by X-rays, staurosporine and etoposide. Then, we studied whether the DNA-PKcs is cleaved during UV-induced apoptosis in keratinocytes. We used the well-characterized cloned human keratinocyte cell line HaCaT, which carries p53 mutations. UVB-induced apoptotic cells were observed by TdT-mediated deoxyuridine 5'-triphosphate nick end labeling (TUNEL) assay and agarose gel electrophoresis. Western blot analysis was performed using the antibody against DNA-PKcs. The cleavage occurred during UVB-induced apoptosis in HaCaT cells. It suggests that the cleavage is associated with loss of DNA-PK activity. Thus, a functional relevance of cleavage of DNA-PKcs may be to prevent rejoining fragmented DNA during apoptosis, thereby promoting apoptotic processes. Although apoptosis was not completely blocked by the caspase-3 inhibitor, the cleavage of the DNA-PKcs was blocked. These results indicate that DNA-PKcs is cleaved by the caspase-3 for UVB-induced apoptosis in HaCaT cells.

The active molecular form of plasma adrenomedullin is extracted in the pulmonary circulation in patients with mitral stenosis: possible role of adrenomedullin in pulmonary hypertension

Adrenomedullin (AM), a novel hypotensive peptide, preferentially dilates pulmonary vessels rather than systemic vessels. This suggests the possibility that AM is a circulating hormone which participates in regulation of the pulmonary circulation. A recent study revealed that two molecular forms of AM, i.e. a mature, active form of AM (AM-m) and an intermediate, inactive, glycine-extended form of AM (AM-Gly), circulate in human plasma. In the present study we investigated the production and clearance sites and pathophysiological significance of the two molecular forms of AM in the pulmonary circulation in patients with mitral stenosis. We measured the plasma levels of AM-m and total AM (AM-T; AM-m+AM-Gly) using a recently developed specific immunoradiometric assay, and thus calculated plasma AM-Gly levels, in blood samples obtained from the femoral vein, pulmonary artery, left atrium and aorta of 28 consecutive patients with mitral stenosis (20 females and eight males; age 53+/-10 years). Patients with mitral stenosis had significantly higher venous concentrations of AM-T, AM-Gly and AM-m than age-matched normal controls (AM-T, 15.9+/-2.5 and 10.6+/-2.1 pmol/l respectively; AM-Gly, 14.0+/-2.1 and 9.8+/-1.9 pmol/l respectively; AM-m, 1.9+/-0.6 and 1.1+/-0.3 pmol/l respectively; each P<0.001). There was a significant decrease in the concentrations of AM-m and AM-T between the pulmonary artery and the left atrium (AM-T, 16.1+/-2.7 and 14.0+/-2.4 pmol/l respectively; AM-m, 2.0+/-0.6 and 0.7+/-0.2 pmol/l respectively; each P<0.001); however, there were no differences in plasma AM-Gly levels between the pulmonary artery and the left atrium (14.1+/-2.3 and 13.5+/-2.3 pmol/l respectively). The venous concentrations of AM-m, AM-Gly and AM-T showed similar correlations with mean pulmonary artery pressure (AM-T, r=0.67; AM-Gly, r=0.63; AM-m, r=0.59; each P<0.001) and total pulmonary vascular resistance (AM-T, r=0.77; AM-Gly, r=0.70; AM-m, r=0.75; each P<0.001). These results suggest that the plasma concentration of AM-m is increased in parallel with those of AM-Gly and AM-T, and that the main site for clearance of AM-m from the plasma is the lung; the extracted AM-m in the lungs may help to attenuate the increased pulmonary arterial resistance in secondary pulmonary hypertension due to mitral stenosis.

Identification of an alpha-tubulin mutant of fission yeast from gamma-tubulin-interacting protein screening: genetic evidence for alpha-/gamma-tubulin interaction

gamma-Tubulin has been determined to be a central element of microtubule nucleation and, thus, indispensable for cellular organization of the microtubule. Utilizing the fact that human gamma-tubulin can function in the fission yeast Schizosaccharomyces pombe, we have generated a unique mutant screening procedure which can specifically select mutants of genes encoding gamma-tubulin-interacting proteins. One of the isolated mutants, cs76, turned out to carry a mutation in the alpha 1-tubulin gene (nda2(+)). This result suggests a direct interaction between the alpha- and gamma-tubulins. We located the mutation site in the nda2 gene and characterized the mutant phenotype. Our results demonstrate the importance of the alpha-/gamma-tubulin interaction in microtubule nucleation and should complement previous knowledge.

Inhibitory influences of tranilast on multinucleated giant cell formation from monocytes by supernatant of concanavalin A-stimulated mononuclear cells

Tranilast is an anti-allergic drug that inhibits the release of chemical mediators from mast cells. There have been cases-reports showing that tranilast is effective for the treatment of granulomatous diseases such as granuloma annulare and cutaneous sarcoidosis. Here we examined the in vitro effects of tranilast on the formation of multinucleated giant cells (MGCs) from human peripheral monocytes. Supernatant of concanavalin A (Con A)-stimulated mononuclear cells induced Langhans-type and foreign body-type MGCs and the addition of 10 or 100 microg/ml tranilast inhibited the formation of total MGCs and foreign body-type MGCs. Tranilast decreased the number of MGCs with 16<nuclei and increased that of MGCs with three to five nuclei. Fluorescence-activated cell sorting analysis showed that tranilast-treated monocytes had lower expressions of intercellular adhesion molecule-1 (ICAM-1). These findings suggest that tranilast is effective for cutaneous lesions in some cases of granulomatous disorders partly through a direct effect on monocyte/macrophage-lineage cells.

Urocortin, a member of the corticotropin-releasing factor family, in normal and diseased heart

In the present study we investigated the form of expression, action, second messenger, and the cellular location of urocortin, a member of the corticotropin-releasing factor (CRF) family, in the heart. Urocortin mRNA, as shown by quantitative RT-PCR analysis, is expressed in the cultured rat cardiac nonmyocytes (NMC) as well as myocytes (MC) in the heart, whereas CRF receptor type 2beta (CRF-R2beta), presumed urocortin receptor mRNA, is predominantly expressed in MC compared with NMC. Urocortin mRNA expression is higher in left ventricular (LV) hypertrophy than in normal LV, whereas CRF-R2beta mRNA expression is markedly depressed in LV hypertrophy compared with normal LV. Urocortin more potently increased the cAMP levels in both MC and NMC than did CRF, and its effect was more potent in MC than in NMC. Urocortin significantly increased protein synthesis by [(14)C]Phe incorporations and atrial natriuretic peptide secretion in MC and collagen and increased DNA synthesis by [(3)H]prolin and [(3)H]Thy incorporations in NMC. An immunohistochemical study revealed that urocortin immunoreactivity was observed in MC in the normal human heart and that it was more intense in the MC of the human failing heart than in MC of the normal heart. These results, together with the recent evidence of urocortin for positive inotropic action, suggest that increased urocortin in the diseased heart may modulate the pathophysiology of cardiac hypertrophy or failing heart, at least in part, via cAMP signaling pathway.

Effect of neutral endopeptidase inhibitor on endogenous atrial natriuretic peptide as a paracrine factor in cultured cardiac fibroblasts

1. Cardiac remodelling is a fundamental response to hypertension, myocardial infarction and chronic heart failure, and involves cardiac fibroblast proliferation and production of extracellular matrix components such as collagen. The present study was performed to examine the role of endogenous atrial natriuretic peptide (ANP) as a possible paracrine factor for cardiac fibroblasts, and to examine the effects of three neutral endopeptidase (NEP) inhibitors, thiorphan, phosphoramidon and ONO-BB-039-02 (ONO-BB) on endogenous ANP-induced changes in collagen synthesis by cultured neonatal rat cardiac fibroblasts. 2. Each NEP inhibitor singly had no significant effect on collagen synthesis by cardiac fibroblasts, except for maximum concentration (10(-3) M) of thiorphan. 3. Exogenous ANP inhibited collagen synthesis in a concentration-dependent manner (10(-8) - 10(-6) M). Thiorphan (10(-4) and 10(-3) M) and phosphoramidon (10(-5) and 10(-4) M) enhanced the ANP (10(-7) M)-induced decrease in collagen synthesis. ONO-BB (10(-5) and 10(-4) M) slightly enhanced the ANP-induced decrease in collagen synthesis. 4. Myocyte-conditioned medium (MC-CM), as well as exogenous ANP, inhibited collagen synthesis dose-dependently. The decrease in collagen synthesis at 100% MC-CM was augmented by thiorphan (10(-3) M), phosphoramidon (10(-4) M) and ONO-BB (10(-4) M). 5. HS-142-1, a natriuretic peptide receptor antagonist, significantly reduced the MC-CM plus thiorphan- and MC-CM plus ONO-BB-induced decrease in collagen synthesis, by 92 and 62%, respectively and showed a tendency to attenuate the MC-CM plus phosphoramidon-induced decrease in collagen synthesis by 40%. 6. Our observations suggested that endogenous ANP released from cardiomyocytes inhibited collagen synthesis as a paracrine factor and that NEP inhibitors enhanced the activity of this peptide in cardiac fibroblasts.

The possible role of reactive oxygen species generated by neutrophils in mediating acne inflammation

The purpose of this study was to investigate the possible role of reactive oxygen species (ROS) generated by neutrophils in mediating acne inflammation. Antibiotics used for the treatment of acne significantly inhibited ROS generated by neutrophils, when compared to other antibiotics. Metronidazole, which is effective in the treatment of acne, markedly inhibited ROS generated by neutrophils. The drug is known to have no significant effect on the growth of Propionibacterium acnes. The proportion of linoleic acid is markedly decreased in acne comedones. Linoleic acid significantly suppressed ROS generated by neutrophils. The ability of neutrophils to produce ROS was significantly increased in patients with acne inflammation. These results seem to reveal the involvement of ROS generated by neutrophils in the disruption of the integrity of the follicular epithelium, which is responsible for inflammatory processes of acne.

Promotive effects of a silk film on epidermal recovery from full-thickness skin wounds

We examined the effects of the transparent fibroin film (silk film) on full-thickness skin wounds. Full-thickness dermatotomies (15 mm x 9 mm) were prepared on the dorsal wall of CRJ:CD-1 nu/nu (ICR nu/nu) mice. The area of the wounds dressed with silk film was reduced to 10% of that made by the dermatotomy 14 days after the dermatotomy and were covered with regenerated epidermis 21 days after the dermatotomy. In contrast, less recovery and epidermal regeneration were found 14 days after dermatotomy in the wounds dressed with a conventional hydrocolloid dressing (Duro Active). Furthermore, only partial incomplete epidemal growth was obtained 21 days after dermatotomy. Most importantly, the healing time of wounds dressed with silk film was 7 days shorter than those dressed with DuoActive dressing. The silk film showed an almost similar or slightly better promotive effect as the lyophilized porcine dermis (Alloask D), which is used as a dressing for burns, ulcers, and decubitis. Histologic findings revealed that there was greater collagen regeneration and less inflammation and neutrophil-lymphocyte infiltration of the wounds dressed with silk film than with DuoActive dressing. It is clear that regeneration of the epidermis and dermis of the wound beds covered with silk film was faster than with DuoActive dressing. Finally, silk film is easily obtainable, sterilizable, and transparent, and it allows easy observation of tissue recovery. Therefore, silk film offers advantages over other dressings and may be clinically useful for wound treatment.

Successful treatment of lichen myxoedematosus with PUVA photochemotherapy

Lichen myxoedematosus is an unusual disorder of unknown etiology and pathogenesis. Although several treatments have reportedly been tried, therapeutic efficacies are variable and unsatisfactory. A patient with severe skin changes of this disease was successfully treated with PUVA photochemotherapy. PUVA therapy was carried out using 30 mg of 8-methoxypsoralen orally, and subsequent exposure to UVA starting at 4 J/cm2. The eruption disappeared almost completely after 35 treatments at a cumulative dose of 202 J/cm2. Histologically, mucin deposition was greatly diminished after the therapy. The photochemotherapy may exert its effect directly by inhibiting proliferation of fibroblasts and synthesis of mucopolysaccharides, and also indirectly by immunomodulating action.

Protective effects of sunscreening agents on photocarcinogenesis, photoaging, and DNA damage in XPA gene knockout mice

We investigated the protective effects of commercial sunscreening agents against UVB-induced photoresponses in group A xeroderma pigmentosum (XPA) model mice. XPA gene-deficient mice are defective in nucleotide excision repair and show a high incidence of skin tumors and severe acute inflammation in response to UVB irradiation, in a similar manner to XP patients. SPF 10 and SPF 60 sunscreens protected partially and almost completely, respectively, ear swelling responses produced by UVB up to 200 mJ/cm2 in (-/-) mice. XPA (-/-) mice were irradiated three times a week to a cumulative dose of 2.6 J/cm2 UVB for a period of 24 weeks with or without SPF 10 or SPF 60 sunscreen. UV-induced skin tumors had developed in all unprotected (-/-) mice (13.3 tumors per mouse) at the completion of UVB irradiation. The SPF 60 sunscreen afforded stronger protection against photocarcinogenesis (1.0 tumors per mouse) than the SPF 10 sunscreen (4.4 tumors per mouse). Regarding photoaging, SPF 60 sunscreen also protected against mast cell infiltration (79% inhibition), elastic fiber accumulation, and dermal cyst proliferation in XPA (-/-) mice compared with unprotected (-/-) mice. In (-/-) mice, the SPF 60 sunscreen provided stronger protection against cyclobutane pyrimidine dimer formation shown immunohistologically following irradiation with 200 mJ/cm2 UVB than the SPF 10 sunscreen. The XPA model mouse is a useful animal for the evaluation of the photoprotective ability of sunscreens because photoresponses, even chronic changes, can be easily and quickly induced experimentally.

Establishment of a tissue culture system for hamster sebaceous gland cells

BACKGROUND

A human sebaceous gland culture system is very useful in studying the functions of the sebaceous glands at the cellular level. On the other hand, the success rates for culture systems and the experimental results from these human culture systems exhibit significant fluctuations, depending on the condition of the donor skin.

OBJECTIVE

The purpose of this study was to establish a stable culture system in order to investigate the functions of the sebaceous glands under uniform conditions.

METHODS

Sebaceous glands from the auricles of 5-week-old hamsters were isolated and seeded onto a 3T3 cell feeder layer. The proliferation, lipid production and response to androgens of these sebaceous-gland-derived cells (SGDC) were then examined.

RESULTS

The SGDC showed outgrowth, formed colonies and became confluent in a 35-mm dish culture after 14 days in primary culture. The amount of intracellular lipids significantly increased following the peak of the cell proliferation. The composition of the intracellular lipids from the hamster SGDC was identical to human SGDC, except that the hamster SGDC did not contain any squalene. Testosterone and 5alpha-dihydrotestosterone markedly stimulated the proliferation of these SGDC in a dose-dependent manner.

CONCLUSION

This tissue culture system will be a useful tool for the study of sebaceous gland function at the cellular level.

Recurrent follicular and lichenoid papules of sarcoidosis

We describe a 62-year-old Japanese woman who exhibited recurrent follicular lichenoid lesions of sarcoidosis. The skin lesions appeared all over the surface of the body without any other organ involvement, and spontaneously regressed within 1 year. Two years later, the lesions recurred on the trunk, especially in the intertriginous areas such as the submammary areas and in fatty folds of the abdomen, and on the thighs and upper arms, with the appearance of uveitis of the right eye. Histological examinations showed that small epithelioid cell granulomas were localized in the perifollicular areas. The present case was characterized by a unique distribution of follicular lichenoid eruptions, which are rare manifestations of sarcoidosis and recurrence of the lesions.

Development of non-bacterial thrombotic endocarditis after percutaneous transvenous mitral commissurotomy for severely calcified mitral stenosis

We encountered a case of mitral stenosis, complicated with non-bacterial thrombotic endocarditis, that developed after percutaneous transvenous mitral commissurotomy (PTMC). A 71-year-old female Japanese patient had severe congestive heart failure and underwent PTMC for critical and severely calcified mitral stenosis. Four weeks later, the echocardiogram demonstrated a highly echoic protrusion in the postero-medial commissure of the mitral valve. There was little evidence of inflammation at that time. She had been anticoagulated adequately since she was admitted. The patient underwent replacement of the mitral valve. She did not show any evidence of systemic embolization. Microscopic evaluation showed only organized thrombus but no evidence of inflammation in the mitral valve. Silent development of non-bacterial thrombotic endocarditis after PTMC should be recognized as a rare but potentially lethal complication of PTMC.

Effects of various taste stimuli on heart rate in humans

Relationships between taste stimuli and heart rate were evaluated in 29 healthy university students. The test solutions were sucrose, NaCl, citric acid, quinine-HCl and monosodium glutamate (MSG). Heart rate increased by 7.1-13.6% for all the taste stimuli after use as compared with pre-stimuli values. The maximum increases in heart rate came approximately 25 s after the taste stimuli. After the increases, heart rate returned to pre-stimuli levels after between 80 and 100 s. Heart rate reached its maximum with citric acid. Recovery from the heart-rate increase was more delayed for quinine-HCl and MSG than for the other stimuli. Except for sucrose, increases in heart rate and the hedonic scale values of the taste solutions showed significant negative correlation. These findings show that the taste stimuli solutions increased the heart rate and that the increase differed with the concentration and taste solution used.

Differentiation from thymic B cell progenitors to mature B cells in vitro

The role of the thymic microenvironment in the development of murine thymic B cells has yet to be fully clarified. We therefore investigate the microenvironment that supports the development of mature thymic B cells (sIg+/B220+/CD43-B cells) from thymic B cell progenitors with immunophenotypes of sIg-/B220med/CD43+ cells. As we have previously reported, thymic B cells generated from these progenitors in the thymus are CD5+ B cells. We next study the in vitro condition that supports the differentiation of thymic B cell progenitors. Stromal cells (from the bone marrow or thymus), thymus-derived cell lines with the character of thymic nurse cells (TNCs) or thymic epithelial cells (TECs), or the bone marrow-derived cell line (MS-5) are tested for their ability to support B-lymphopoiesis from thymic B cell progenitors. Interestingly, thymic stromal cells (but neither stromal cells from the bone marrow nor stromal cell lines) support the differentiation of thymic B cell progenitors into thymic B cells in the presence of IL-7. Cortical epithelia (but not medullary epithelia, thymic macrophages or dendritic cells) are found to contribute to thymic B cell differentiation. Surface phenotype and Ig rearrangement analyses reveal that mature B cells generated in this condition are primarily CD5+ B cells, indicating that the thymic microenvironment (particularly cortical epithelia) determines the differentiation of thymic B cells.

Preservation of the right atrial appendage improves reduced plasma atrial natriuretic peptide levels after the maze procedure

OBJECTIVES

The present study was conducted to determine whether preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and whether the increase of plasma atrial natriuretic peptides improves the ability of the kidneys to excrete the fluid load after the operation.

METHODS

We evaluated 42 patients who underwent the maze procedure. The right atrial appendage was preserved in 22 patients but not in 20. Blood samples were obtained before and after the operation for measurement of atrial natriuretic peptides. To evaluate the influence of atrial natriuretic peptides on the ability of the kidneys, we also measured body weight, fluid balance, and the doses of furosemide and dopamine administered after the operation.

RESULTS

The restoration to sinus rhythm at 1 month after was comparable in the two groups. Plasma atrial natriuretic peptide levels significantly increased after the operation in patients in whom the right atrial appendage was preserved (1 day after: 23.4 +/- 17.8 vs 3 days after: 42.7 +/- 23.6 and 7 days after: 36.3 +/- 23.7 pg/mL, P <.05) but not in patients in whom the right atrial appendage was not preserved (1 day after: 20.0 +/- 19.6, 3 days after: 28.5 +/- 19.3, and 7 days after: 23.0 +/- 16.1 pg/mL). Furthermore, plasma atrial natriuretic peptide levels were significantly lower in patients in whom the right atrial appendage was not preserved than in patients in whom the right atrial appendage was preserved at 3 and 7 days after the operation. The fluid balance during the first 7 days of the postoperative period was comparable in the two groups, although the total dose of dopamine used in the same period was significantly smaller in patients in whom the right atrial appendage was preserved than in patients in whom the right atrial appendage was not preserved (155.3 +/- 119.0 vs 244.9 +/- 129.0 microg/kg, P <.05).

CONCLUSIONS

The present study showed that preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and that increased plasma atrial natriuretic peptides may improve the ability of the kidneys to excrete the fluid load after the operation.

Cardiac adrenomedullin gene expression and peptide accumulation after acute myocardial infarction in rats

Plasma adrenomedullin (AM) has been shown to increase in the early phase of acute myocardial infarction (MI). However, little information is available regarding cardiac AM synthesis after MI. Accordingly, we examined the time course of ventricular AM production and potential stimulation of AM in the infarcted and noninfarcted regions in MI rats produced by coronary artery ligation. Compared with sham-operated rats, the ventricular AM peptide level 6 h after MI increased 1.5-fold in the infarcted region and 1.7-fold in the noninfarcted region in association with increased left ventricular end-diastolic pressure (EDP). Northern blot analysis also showed marked induction of AM gene expression in the infarcted region (11-fold) and the noninfarcted region (6-fold) 6 h after MI. The AM peptide level in the infarcted region reached its peak (2. 6-fold) 1 wk postinfarction and thereafter decreased to normal. In the noninfarcted region, however, the AM level remained elevated for at least 4 wk. Immunohistochemical studies demonstrated that intense immunostaining for AM was limited to myocytes in both the infarcted and noninfarcted regions. Interestingly, the AM level in the noninfarcted region correlated positively with infarct size (r = 0. 40, P < 0.01) and EDP (r = 0.52, P < 0.001). An oral angiotensin-converting enzyme inhibitor suppressed the overproduction of AM 1 wk postinfarction in association with decreases in EDP and mean arterial pressure. In summary, cardiac AM synthesis was rapidly induced in both the infarcted and noninfarcted regions after MI. The subsequent ventricular AM in the two regions demonstrated different time-concentration curves during 4 wk after MI. AM may be synthesized predominantly by cardiac myocytes, but not by fibroblasts, at least in part, in association with increased ventricular load after MI.

Indications and action mechanisms of phototherapy

Recently phototherapy has become one of the most commonly used modalities for the treatment of a variety of skin diseases, although the action mechanisms have not been fully understood. The inhibitory effect of UVR on DNA synthesis may be one of the actions for proliferating skin diseases. However, phototherapy is also used for the treatment of allergic or autoimmune diseases. It has been confirmed that the skin is an important immunologic organ whose constitutive cells are all involved in immunologic reactions. We have investigated the effects of PUVA and UVB radiation on the immunocompetent cells, including Langerhans cells, T lymphocytes, mast cells, endothelial cells and natural killer cells. Exposure to UVR inhibits contact sensitization to haptens applied not only to the irradiated skin area but also to the non-irradiated distant skin when the exposure dose is relatively high and/or the application skin area is large. In addition, hapten-specific tolerance develops by the generation of suppressor T cells. Phototherapy is also useful for immediate type hypersensitivity such as urticaria. Action mode in the case may be the inhibitory effects of UVR on histamine release from mast cells. The results obtained from these experiments suggest that phototherapy exerts its anti-allergic and anti-inflammatory effects through immunosuppression.

Protective role of copper, zinc superoxide dismutase against UVB-induced injury of the human keratinocyte cell line HaCaT

On the basis of our recent observation that copper, zinc-superoxide dismutase and manganese-superoxide dismutase change differently following a single exposure to ultraviolet-B irradiation in the human keratinocyte cell line HaCaT, we have examined the possible role of endogenous copper,zinc-superoxide dismutase or manganese-superoxide dismutase against ultraviolet-B-induced reactive-oxygen- species-mediated keratinocyte injury in vitro. To evaluate the individual defensive roles of copper, zinc-superoxide dismutase and manganese-super-oxide dismutase, we treated HaCaT cells with diethyldithiocarbamate, a chelating agent of ionic copper that inactivates copper,zinc-superoxide dismutase activities, tumor necrosis factor alpha, which enhances manganese-superoxide dismutase levels, or transforming growth factor beta1, which inhibits manganese-superoxide dismutase levels. After the treatment with each reagent, HaCaT cells in the three different conditions were exposed to a single dose of ultraviolet-B irradiation. We assessed ultraviolet-B-induced cytotoxicity by measuring both lactate dehydrogenase leakage and cell viability using trypan blue dye exclusion assay. The lactate dehydrogenase leakage in the supernatant from damaged HaCaT cells whose copper,zinc-superoxide dismutase levels were inactivated by diethyldithiocarbamate was significantly increased and the cell viability was significantly decreased in comparison with untreated groups at 8 and 24 h after ultraviolet-B irradiation. On the other hand, the lactate dehydrogenase release and cell viability for HaCaT cells whose manganese-superoxide dismutase levels were enhanced by tumor necrosis factor alpha or inhibited by transforming growth factor beta1 showed no significant difference from untreated groups. Furthermore, increased production of intracellular peroxides in HaCaT cells treated with diethyldithiocarbamate was observed by flow cytometric analysis at 8 h after ultraviolet-B irradiation. These results suggest that copper,zinc-superoxide dismutase may play a primary protective role against ultraviolet-B-induced injury of the human keratinocyte cell line HaCaT.

Possible involvement of enhanced prostaglandin E2 production in the photosensitivity in xeroderma pigmentosum group A model mice

Xeroderma pigmentosum group A (XPA) gene-deficient mice cannot repair UV-induced DNA damage and easily develop skin cancers by UV irradiation. Therefore, XPA-deficient mice are a useful model of human XP and represent a promising tool for photobiologic studies of the disorder. Exposure to ultraviolet (UV) B (280-320 nm) radiation greatly enhanced inflammation and immunosuppression in these mice. To investigate the molecular mechanisms of enhanced UV inflammation and immunosuppression, we determined the amount of prostaglandin (PG) E2, an inflammatory mediator and immunomodulator, and analysed the expression of cyclooxygenase (COX) mRNA in the ear skin of XPA-deficient mice after UV irradiation. In XPA-deficient mice, the amount of PGE2 significantly increased at 48 and 72 h after UVB irradiation to the level that was 8- and 16-fold higher than those in wild-type mice, respectively. The expression level of COX-2 mRNA increased in a time-dependent manner, although COX-1 mRNA was constantly expressed. Treatment with indomethacin, a potent inhibitor of PG biosynthesis, inhibited UV-induced ear swelling, abrogated local immunosuppression, and decreased the amount of PGE2 in the ear skin of XPA-deficient mice. These results indicate that the excess DNA photoproducts remaining in XPA-deficient cells after UV radiation may induce COX-2 expression. The induced production of PGE2 may be involved in the enhanced inflammation and immunosuppression caused by UV radiation in XPA-deficient mice and XP patients.

Ventricular adrenomedullin concentration is a sensitive biochemical marker for volume and pressure overload in rats

This study was designed to investigate the pathophysiological significance of adrenomedullin (AM) concentration in volume- and pressure-overloaded cardiac hypertrophy. We measured ventricular AM concentrations and compared them with changes of alpha-actin and myosin heavy chain (MHC) mRNA isoforms after the creation of an aortocaval (AC) shunt as a volume-overload model or the injection of monocrotaline (MCT) as a pressure-overload model, respectively. The left ventricular AM levels after the creation of AC shunt and the right ventricular AM levels after the injection of MCT were significantly increased and correlated with changes of the alpha-actin and MHC mRNA isoforms. However, the ventricular AM mRNA expressions were increased and correlated with ventricular AM concentrations only in the AC shunt model. These results suggest that the ventricular AM levels are upregulated in both the volume- and pressure-overloaded cardiac hypertrophy by differential transcriptional regulation and that the ventricular AM may be a biochemical marker for the volume and pressure overload to the ventricle.

Inhibitory regulation of hypertrophy by endogenous atrial natriuretic peptide in cultured cardiac myocytes

Atrial natriuretic peptide (ANP) may function as an endogenous regulator of cardiac hypertrophy, because the natriuretic peptide receptor has been found in the heart and because mice lacking its receptor have been shown to have a markedly elevated ventricular mass. We examined the role of endogenous ANP in cardiac hypertrophy in vitro. The effects of the blockade of endogenous ANP by its receptor antagonist, HS-142-1, on cell hypertrophy were investigated with the use of cultured neonatal rat ventricular myocytes. HS-142-1 increased the basal and phenylephrine (PE, 10(-5) mol/L)-stimulated protein syntheses in a concentration-dependent manner (1 to 300 microg/mL). A significant increase in the cell size of myocytes was also induced by this antagonist. In addition, the expression levels of skeletal alpha-actin, beta-myosin heavy chain, and ANP genes, markers of hypertrophy, were partially elevated by treatment with HS-142-1 (100 microg/mL) under nonstimulated or PE-stimulated conditions. A cGMP-specific phosphodiesterase inhibitor, zaprinast (5x10(-4) mol/L), and a cGMP analogue (10(-4) mol/L) suppressed the basal and PE-stimulated protein syntheses. Our observations suggest that endogenous ANP inhibits cardiac myocyte hypertrophy under basal and PE-stimulated conditions, probably through a cGMP-dependent process. ANP may play a role as an autocrine factor in the regulation of cardiac myocyte growth.

The clinical and photobiological characteristics of solar urticaria in 40 patients

Forty patients with solar urticaria, 16 male and 24 female, were examined personally during the past 25 years. The median age at onset of symptoms was 32 years, ranging from 13 to 76 years. Most commonly (45%) solar urticaria first appeared during the third decade. The mean duration of the disease was 3.6 years at presentation. The action spectrum was found in the visible light range in 24 patients (60%), in the ultraviolet (UV) A range in four, in the UVB in four, from the UVA to UVB in three, from the UVA to visible light in one and in a broad range from UVB to visible light in four patients. An inhibition spectrum was detected in 13 of 19 patients (68%), occurring at longer wavelengths than the action spectrum in 12 of these cases. The augmentation spectrum was found in only four of 14 patients (29%) examined. Twenty-four of 31 patients (77%) developed an urticarial reaction to autologous serum, which had been previously irradiated in vitro at the action spectrum for that patient. In a single patient, solar urticaria was caused by a drug, namely chlorpromazine. In two patients, polymorphic light eruption occurred in association with solar urticaria. No single modality of treatment was satisfactory, but combined use of antihistamines, sunbathing, psoralen UVA photochemotherapy and/or sunscreening agents partially suppressed the symptoms.

Age-dependent abnormalities of hematopoietic stem cells in (NZW x BXSB)F1 mice

The (NZW x BXSB)F1 (W/BF1) mouse is known as an autoimmune-prone strain which develops lupus nephritis, thrombocytopenia due to platelet-specific autoantibodies, leukocytosis, and myocardial infarction. In this experiment, we investigated the age-dependent abnormalities of the hematopoietic stem cells (HSCs) and hematopoiesis in this mouse. White blood cell counts (especially Mac-1- or Gr-1-positive cells) in the peripheral blood of 12-week-old W/BF1 mice increased in comparison with those of four-week-old W/BF1 or normal mice. To investigate whether the abnormal hematopoiesis can be attributed to the HSCs of W/BF1 mice, colony-forming unit in spleen (CFU-S) and colony-forming unit in culture (CFU-C) assays were performed. Day 12 CFU-S counts of 12-week-old W/BF1 mice significantly increased in comparison with those of four-week-old W/BF1 mice or normal mice. In the CFU-C assay, CFU-GEMM and CFU-GM counts in 12-week-old W/BF1 mice increased in comparison with those of four-week-old W/BF1 or control mice. The bone marrow cells (BMCs) from 12-week-old W/BF1 mice showed a high level of G-CSF and a low level of GM-CSF in mRNA expression. To examine the effect of HSCs from 12-week-old W/BF1 mice on the onset of autoimmune diseases and the abnormal hematopoiesis, T- and B-cell-depleted BMCs of four-week-old or 12-week-old W/BF1 mice were transplanted to C3H mice. Recipient C3H mice that had received the BMCs from 12-week-old W/BF1 mice showed an earlier onset of autoimmune diseases and a shorter survival rate than those that had received the BMCs from four-week-old W/BF1 mice. These data suggest that the HSCs from 12-week-old W/BF1 mice showing the symptoms of autoimmune diseases have the capacity to induce autoimmune diseases earlier than the HSCs from four-week-old W/BF1 mice.

Lethal level overexpression of gamma-tubulin in fission yeast causes mitotic arrest

gamma-Tubulin is a member of the tubulin superfamily and plays essential roles in microtubule nucleation. While the level of other tubulins, alpha- and beta-tubulin, is strictly regulated in higher eukaryotes and overexpression of beta-tubulin is toxic in yeasts, gamma-tubulin can be overexpressed by fivefold in fission yeast without any obvious defect in growth. Extreme overexpression of gamma-tubulin in mammalian cells caused growth arrest; however, the exact level of gamma-tubulin and the critical level of gamma-tubulin necessary for growth defect were undetermined. We have constructed strains that over- or underexpress gamma-tubulin by placing the gamma-tubulin gene under the control of the inducible nmt1 promoter and its variants. Among these, the weakest promoter was able to produce enough gamma-tubulin to support normal growth when its expression was induced. A strain in which the gamma-tubulin gene was placed under the control of the strongest inducible promoter achieved 160-fold overexpression of gamma-tubulin and its growth was suppressed. Normal cytoplasmic microtubules were mostly lost in gamma-tubulin overexpressing cells and gamma-tubulin was accumulated around the periphery of nuclei. Many of the cells were arrested in mitosis. A small fraction of cells did proceed to undergo nuclear division; however, its process looked either significantly deterred or abnormal. Our results presented here suggest that excess gamma-tubulin disrupts the microtubule array and significantly deters the formation of the mitotic spindle, most likely because of random nucleation of microtubules from excess gamma-tubulin in the cytoplasm.

Evaluation of adjunctive intracoronary administration of acetylcholine following intravenous infusion of ergonovine to provoke coronary artery spasm

A dilemma arises in patients with chest pain or other symptoms suggestive of coronary artery disease but without significant coronary artery stenosis or spasm even after the spasm provocation test by either ergonovine or acetylcholine. Incremental doses of intracoronary acetylcholine (up to 100 micrograms for left coronary artery and 50 micrograms for right coronary artery) were administered when intravenous infusion of ergonovine 0.4 mg showed negative results. A total of 39 patients were studied. Provocation test was performed because of chest pain suggestive of coronary artery disease (n = 19), atypical chest pain (n = 6), post balloon angioplasty status (n = 6), silent ischemia (n = 4), Adams-Stokes syndrome (n = 3), and dead-on-arrival (n = 1). Characteristics of chest pain indicated variant angina (n = 11), rest angina (n = 4), and effort angina (n = 4). No electrocardiographic evidence of ischemia was detected before this test in any patient. Spasm was induced in 23 patients (59.0%) with complete obstruction in 7 (30.4%), diffuse vasoconstriction (90-99%) in 14 (60.9%), and focal spasm in 2 (8.7%). The patients with chest pain showed the highest positive rate of 78.9%. Further, the patients with atypical chest pain and miscellaneous reasons also revealed positive rates of 33.3% and 42.9%, respectively. One ventricular tachycardia and 2 atrial fibrillations occurred but terminated spontaneously. This test is useful for detecting spasm in a variety of patients in whom intravenous ergonovine infusion fails to induce spasm.

Evaluation of apoptotic cells induced by ultraviolet light B radiation in epidermal sheets stained by the TUNEL technique

Two major components of epidermal cells, keratinocytes and Langerhans cells, are injured by ultraviolet light B radiation, resulting in sunburn cell (apoptotic cell) formation, impaired function, and a reduced number of Langerhans cells. Quantitative analysis of Langerhans cell damage is usually performed using epidermal sheets, whereas that of keratinocytes has been performed by counting the number of sunburn cells in vertical tissue sections. In this study we assessed the influences of ultraviolet light B radiation on epidermal cells by apoptotic cell formation, using murine epidermal sheets stained by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique. Ten to 75 mJ per cm2 of ultraviolet light B radiation induced apoptotic cells in abdominal skin of C3H mice. The cells were induced in 6 h after 50 mJ per cm2 of ultraviolet light B irradiation with the peak in number in 24 h, 18.8 +/- 5.0 per mm2 and 97.7 +/- 7.4 per mm2, respectively. One week later, the apoptotic cells were not visualized. As C3H/He, BALB/C, and C57BL/6 mice showed almost the same frequency of apoptosis in epidermal sheets from 50 mJ per cm2 ultraviolet light B-irradiated skin, the induction of the cells by ultraviolet light B radiation did not depend on the genetic trait of the mouse. Xeroderma pigmentosum type A gene-deficient mice, however, showed a greater induction of apoptotic cells (216.9 +/- 25.2 per mm2) by ultraviolet light B radiation than xeroderma pigmentosum type A wild-type mice (89.5 +/- 13.6 per mm2) and conventional mice. Pretreatment with a SPF 60 sunscreen agent was quite effective in reducing the induction of apoptotic cells. Using confocal laser scanning microscopy and double staining, 1.5 +/- 2.7% of apoptotic cells were Ia-positive cells in 24 h after 50 mJ per cm2 of ultraviolet light B radiation. Apoptotic Ia-positive cells were not observed 48 h after the radiation. On the other hand, no apoptotic dendritic epidermal T cells were observed in up to 75 mJ per cm2 of ultraviolet light B radiated skin. Thus, nearly all apoptotic cells were keratinocytes, and Langerhans cells and dendritic epidermal T cells appeared resistant to ultraviolet light B-induced apoptosis. Compared with the assessment in vertical tissue sections, the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique with epidermal sheets appeared to be a more physiologically relevant method for quantitative evaluation of apoptotic epidermal cells induced by ultraviolet light B radiation.

Effects of adrenomedullin on cultured rat cardiac myocytes and fibroblasts

The direct effects of adrenomedullin, a novel vasorelaxant peptide, on protein synthesis and atrial natriuretic peptide release in myocytes and on DNA and collagen syntheses in fibroblasts were examined using cultured ventricular cardiocytes. The protein synthesis of cardiac myocytes was not affected by adrenomedullin under non-stimulated conditions. Endothelin-1-induced protein synthesis in myocytes was slightly but significantly elevated by adrenomedullin. Likewise, the secretion of atrial natriuretic peptide from myocytes stimulated by endothelin-1 was increased by adrenomedullin. In cardiac fibroblasts, adrenomedullin clearly inhibited DNA synthesis and collagen production in a dose-dependent manner under both basal and angiotensin II-stimulated conditions. DNA and collagen syntheses by cardiac fibroblasts were suppressed by both 8-bromo cAMP and forskolin. Furthermore, a cAMP-specific phosphodiesterase inhibitor decreased DNA and collagen syntheses in fibroblasts and enhanced the inhibitory effects of adrenomedullin on these syntheses. Our observations suggest that adrenomedullin has opposite effects on cultured cardiac myocytes and fibroblasts and that the effects of adrenomedullin at least on fibroblasts are probably mediated through a cAMP-dependent pathway. As adrenomedullin is produced and secreted from both types of cardiac cells, adrenomedullin may play a role as an autocrine/paracrine modulator in the process of cardiac remodeling, mainly by suppressing mitogenesis and collagen synthesis in fibroblasts.

Autonomic function in hypertensive patients with neurovascular compression of the ventrolateral medulla oblongata

OBJECTIVE

To study whether abnormalities of autonomic function exist in patients with essential hypertension and neurovascular compression (NVC) of the medulla oblongata.

SUBJECTS AND METHODS

We studied 25 untreated patients with essential hypertension (13 men and 12 women, 27-74 years old). High-resolution magnetic resonance imaging and magnetic resonance angiography were used to detect NVC. Twenty-four-hour ambulatory monitoring of blood pressure and electrocardiogram were performed, and the power spectrum of heart rate variability was analyzed. On a separate day, various autonomic activity tests, including mental stress, hand grip, cold pressor, and Valsalva maneuver were performed. Baroreflex sensitivity was calculated from changes of blood pressure and R-R interval during phenylephrine infusion. A clonidine suppression test was also performed, with measurement of plasma catecholamine levels.

RESULTS

Fourteen of 25 patients (56%) had NVC (C group), and 11 patients did not have NVC (NC group). There were no significant differences in age, sex, family history, or duration of hypertension between the C and NC groups. Average 24-h systolic blood pressure was similar between the two groups, although 24-h diastolic blood pressure was higher in the C group than the NC group. Daytime, night-time, and 24-h heart rate was significantly higher in the C group than in the NC group. Night-time low frequency/high frequency ratio was slightly higher in the C group. Plasma norepinephrine levels were significantly higher (467 +/- 217 versus 299 +/- 122 pg/ml), and baroflex sensitivity was slightly lower in the C group than in the NC group. Responses of blood pressure and heart rate to mental stress, cold pressor, hand grip, Valsalva maneuver, phenylephrine infusion, and clonidine tests were not significantly different between the two groups.

CONCLUSIONS

NVC of the medulla oblongata was frequently found in patients with essential hypertension. Patients with NVC appeared to have enhanced sympathetic nervous activity compared with those without the compression.

Increased hyperkinesis in noninfarcted areas during short-term follow-up in patients with first anterior acute myocardial infarction treated by direct percutaneous transluminal coronary angioplasty

The time course and clinical significance of hyperkinetic wall motion (HWM) in a noninfarcted area in direct percutaneous transluminal coronary angioplasty (PTCA) has not been clearly demonstrated in patients with acute myocardial infarction (AMI). The objectives of this study were to examine the change in HWM during one-month follow-up after direct PTCA and determine its impact on the recovery of global left ventricular function. A total of 61 patients with first anteroseptal AMI and one vessel disease were evaluated. The paired left ventriculograms in the 30 degrees right anterior oblique view taken both at baseline and follow-up were analyzed by the centerline and area length methods. The severity of hypokinesis was expressed by mean regional wall motion (standard deviation/chord) in most hypocontractile 50% of chords respondable to left anterior descending coronary artery area and HWM by mean regional wall motion in most hypercontractile 50% of chords of noninfarcted area. HWM increased from 0.18 +/- 1.07 to 0.48 +/- 1.30 (p = 0.0608). The delta global ejection fraction (global ejection fraction at follow-up minus global ejection fraction at baseline) was correlated with both delta infarcted wall motion (infarcted wall motion at follow-up minus infarcted wall motion at baseline) and delta HWM (HWM at follow-up minus HWM at baseline) (r = 0.576, p < 0.0001, r= 0.383, p = 0.0036, respectively) during follow-up. Further, the delta global ejection fraction showed better correlation with delta (HWM + infarcted wall motion) [(HWM plus infarcted wall motion at follow-up) minus (HWM plus infarcted wall motion at baseline)] (r= 0.593, p < 0.0001). Direct PTCA resulted in the enhancement of HWVM, which contributed to the increase in the global ejection fraction with the recovery of infarcted wall motion.

Xeroderma pigmentosum variant associated with multiple cancers

A 62-year-old Japanese man with xeroderma pigmentosum (XP) variant is reported. The patient had developed at least 6 basal cell carcinomas, a squamous cell carcinoma, and a malignant melanoma on sun-exposed areas, and an atypical carcinoid on the right lung. In vivo phototesting showed a normal response. The minimal erythema dose of ultraviolet B (UVB) was not lowered and no delayed peaking of the erythema reaction was observed. His skin fibroblasts exhibited higher sensitivity to UV irradiation, but a normal level of unscheduled DNA and RNA synthesis. Cell fusions with XP group A, C, D, E, F, and G cells after UV irradiation were all complemented. Previous reports together with this case suggest that older XP variant patients have a high frequency of not only skin cancers, but also internal malignancies.

Ultraviolet radiation-induced suppression of natural killer cell activity is enhanced in xeroderma pigmentosum group A (XPA) model mice

Xeroderma pigmentosum group A gene-deficient mice easily develop skin cancers by ultraviolet radiation. Natural killer cells play an important part in tumor surveillance. To study whether ultraviolet radiation-induced suppression of natural killer cell function is involved in the high incidence of skin tumors in patients with xeroderma pigmentosum, we analyzed the number and activity of natural killer cells in ultraviolet B-irradiated xeroderma pigmentosum A model mice. The number of natural killer cells in peripheral blood significantly decreased after ultraviolet B-irradiation only in xeroderma pigmentosum A mice, but those in the spleen were not affected. As compared with the wild-type mice, the xeroderma pigmentosum A mice displayed a higher level of spontaneous splenic natural killer cell activity (10%-15% vs 3%) and inducible natural killer activity (30%-50% vs 20%-25%) after injection of polyinosinic:polycytidylic acid. At 24 h after the last irradiation of three and five daily consecutive exposures to 500 mJ per cm2-ultraviolet B, however, the natural killer activity in xeroderma pigmentosum A mice decreased to 60 and 30% of the preirradiated level, respectively, but it did not in the wild-type mice. The depression of natural killer activity in xeroderma pigmentosum A mice recovered to a normal level at 10 and 15 d after the last irradiation, respectively. The high incidence of skin cancers in xeroderma pigmentosum patients may be mainly due to a defect in the repair of ultraviolet-damaged DNA of cutaneous cells, and possibly also due to an intensified ultraviolet-induced immunosuppression. Moreover, the present study suggests that the enhanced ultraviolet-induced impairment of natural killer function could be partially involved in cancer development.

Ventricular adrenomedullin levels correlate with the extent of cardiac hypertrophy in rats

We investigated the pathophysiological significance of adrenomedullin (AM) in the development of left ventricular hypertrophy (LVH). LVH was produced by aortic banding (AB) in rats. The left ventricular weight/body weight (LV/BW) ratio, ventricular AM peptide and mRNA levels, and hemodynamics were measured at 1, 3, 7, and 21 days after the operation. Both LV/BW ratio and ventricular AM levels showed a significant increase from 1 day after the operation in the AB rats versus the sham-operated rats. Both increased in a time-dependent manner. The ventricular AM levels correlated with the LV/BW ratio (r=0.76, P<0.01). The AM mRNA levels were highly expressed at 1 day after the operation in the AB rats but showed no difference from 3 to 21 days after the operation between the AB and sham groups. The plasma AM levels showed a peak at 1 day after the operation in both groups. Then, we treated AB rats with an angiotensin-converting enzyme inhibitor (quinapril) in 2 doses (1 and 10 mg. kg-1. d-1) for 21 days. The quinapril treatment attenuated similarly both the LV/BW ratio and the ventricular AM levels. We also assessed the effects of AM and hydralazine administration for 7 days on the LV/BW ratio and hemodynamics of AB rats. Both AM and hydralazine administration reduced the blood pressure by approximately 10% compared with the nontreated AB rats, but a reduction of the LV/BW ratio was observed only in the AM-treated group (P<0.05). These results suggest that ventricular AM levels are elevated by chronic pressure overload in a time-dependent manner concomitant with the extent of LVH and that AM may play a pathophysiological role in the development of LVH in chronic pressure overload.

Comparison of local and systemic induction of acquired disease resistance in cucumber plants treated with benzothiadiazoles or salicylic acid

The accumulation of chitinase and its involvement in systemic acquired disease resistance was analyzed using acibenzolar-S-methyl and salicylic acid (SA). Resistance against scab (pathogen: Cladosporium cucumerinum) and the accumulation of chitinase were rapidly induced in cucumber plants after treatment with acibenzolar-S-methyl. In contrast, SA protected the plants from C. cucumerinum and the accumulation of chitinase was induced only on the treated leaves. The accumulation of chitinase in response to inoculation with the pathogen was induced more rapidly in cucumber plants previously treated with acibenzolar-S-methyl than in plants pretreated with SA or water. Thus, it appears that a prospective signal(s), that induces systemic resistance, can be transferred from leaves treated with acibenzolar-S-methyl to the untreated upper and lower leaves where systemic resistance is elicited. In contrast, exogenously applied SA is not likely to function as a mobile, systemic resistance-inducing signal, because SA only induces localized acquired resistance.

Suppressive effect of ultraviolet (UVB and PUVA) radiation on superantigen production by Staphylococcus aureus

It is well known that Staphylococcus aureus (S. aureus) proliferates on the moist skin lesion of atopic dermatitis. Reduction of bacteria colonization from skin lesions by antibiotics has been reported to be effective for the treatment of atopic dermatitis. S. aureus produces superantigens which can activate T cells and possibly enhance the inflammatory reaction. Photo(chemo)therapy has been successfully used for the treatment of severe cases of atopic dermatitis. We have previously reported that photo(chemo)therapy had bacteriostatic effect on S. aureus. Now we examined the effect of UVB and psoralen plus UVA (PUVA) on superantigen production from S. aureus. We isolated S. aureus from six atopic dermatitis patients. S. aureus was irradiated in vitro with UVB (0, 5, 10 mJ/cm2) or PUVA (0.001% psoralen plus 0, 5, 10 mJ/cm2 UVA) and incubated 4 h with 100 strokes per min. After incubation, the amounts of superantigens in the supernatant were measured using ELISA kit. The production of superantigens decreased in an ultraviolet dose-dependent manner. The suppressive effects of UV radiation on superantigen production may be involved in the therapeutic efficacy of photo(chemo)therapy for atopic dermatitis.

Cardiovascular and renal effects of adrenomedullin in rats with heart failure

Plasma adrenomedullin (AM), a novel hypotensive peptide, has been shown to increase in heart failure (HF). This study sought to examine the cardiovascular and renal effects of intravenous infusion of AM in HF rats and sham-operated rats (control) using two doses of AM that would not induce hypotension. Rat AM-(1-50) was intravenously administered at rates of 0.01 (low) and 0.05 (high) microg. kg body wt-1. min-1. Low-dose AM increased urine flow (+21% in HF, +29% in control) and urinary sodium excretion (+109% in HF, +123% in control) without changes in any hemodynamic variables. In contrast, high-dose AM slightly decreased mean arterial pressure (-3% in HF, -5% in control) and significantly increased cardiac output (+20% in HF, +12% in control). Infusion of high-dose AM resulted in significant decreases in right ventricular systolic pressure (-11%) and right atrial pressure (-28%) only in HF rats. High-dose AM significantly increased glomerular filtration rate (+10% in HF, +16% in control) and effective renal plasma flow (+25% in HF, +46% in control) as well as urine flow and urinary sodium excretion. In summary, intravenous infusion of AM exerted diuresis and natriuresis without inducing hypotension and, in the higher dose, produced beneficial hemodynamic and renal vasodilator effects in rats with compensated HF.

Photosensitivity reactions caused by lomefloxacin hydrochloride: a multicenter survey

The photosensitivity effect of lomefloxacin hydrochloride (LFLX) was investigated in terms of patient background factors (sex, age, underlying disease, complications, history, occupation, and residential condition, etc.), treatment factors (daily dosage of LFLX, duration of treatment, total dose, concomitant drugs, and previous medication, etc.), and correlations among them. In 100 institutions throughout Japan, 4,284 patients were enrolled over a period of 2 years, beginning in October 1991, avoiding the accumulation of patients in any specific season. Since 8 patients did not visit again after enrollment, the clinical records of 4,276 patients were analyzed. Photosensitivity in 44 patients was found (1.03%), but the symptoms in most patients were not severe and improved after discontinuation of LFLX treatment. The photosensitivity reaction was more prevalent in patients who were 60 years of age and older with concomitant diseases and complications, in patients treated with a total amount of 20 g and more of LFLX for 30 days or longer, and in patients with a history of previous treatment with quinolone drugs. Although the incidence and degree of the photosensitivity reaction vary significantly among new quinolone drugs, every quinolone drug is potentially phototoxic. In particular, long-term use of LFLX should be avoided, and patients taking LFLX should be advised to abstain from prolonged exposure to sunlight.

Production and secretion of adrenomedullin in cultured rat cardiac myocytes and nonmyocytes: stimulation by interleukin-1beta and tumor necrosis factor-alpha

The present study investigated the secretion level and gene expression of adrenomedullin (AM), a novel vasorelaxant peptide, in cultured neonatal rat cardiac myocytes and nonmyocytes, and the effects of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF alpha) on its production and secretion in these cells. Under serum-free conditions, both myocytes and nonmyocytes secreted immunoreactive (ir-) AM into the culture medium in a time-dependent manner. The secretion rates of ir-AM from myocytes and nonmyocytes per 10(5) cells were almost equivalent. The expression of AM messenger RNA was also observed in cultured myocytes and nonmyocytes. The peptide secretion and messenger RNA level of AM in cardiac myocytes were increased after stimulation with IL-1beta. In nonmyocytes, IL-1beta and TNF alpha remarkably augmented both the release of ir-AM into the medium and AM gene expression after 24 and 48 h of incubation. These observations indicate that cardiac ventricular cells (i.e. myocytes and nonmyocytes) actively produce AM and also suggest that cytokines such as IL-1beta and TNF alpha regulate the gene expression and secretion of this peptide in the ventricles. On the basis of these results and the findings that IL-1beta and TNF alpha are involved in heart failure and cardiac hypertrophy, AM may play a role as an autocrine/paracrine modulator in some cardiac disorders.

Cockayne syndrome without typical clinical manifestations including neurologic abnormalities

Although patients with mild symptoms of atypical Cockayne syndrome (CS) have been described, there has not been a report of a patient with CS whose only clinical manifestation was cutaneous photosensitivity. Cells from patients with CS show UV sensitivity, reduced recovery of RNA synthesis, but normal UV-induced unscheduled DNA synthesis. On the other hand, the patients with UV-sensitive syndrome have only cutaneous photosensitivity and skin freckles, whereas those cells respond to UV radiation in a similar fashion to the CS cells. We describe a patient with CS who showed only photosensitivity without typical clinical manifestations of CS, but his cells showed UV sensitivity, reduced recovery of RNA synthesis, and normal unscheduled DNA synthesis after UV radiation similar to CS cells. Furthermore, the patient was assigned to complementation group B of CS on the basis of the results of complementation analysis. The present report suggests that CS has a wider spectrum than that considered previously.

Chronic infusion of adrenomedullin reduces pulmonary hypertension and lessens right ventricular hypertrophy in rats administered monocrotaline

A novel vasorelaxant peptide, adrenomedullin, its messenger ribonucleic acid (mRNA), and the mRNA for its receptor are highly expressed in the lung, suggesting that adrenomedullin may play a role in the regulation of the pulmonary circulation. We investigated whether the chronic infusion of rat adrenomedullin would affect pulmonary hypertension and right ventricular hypertrophy produced by the administration of monocrotaline. Four-week-old male Wistar rats received a single subcutaneous injection of 60 mg/kg monocrotaline and were then chronically and subcutaneously infused with rat adrenomedullin (PH + AM group, n = 8) or saline (PH group, n = 10) by an osmotic minipump for a period of 21 days. Plasma levels of adrenomedullin were significantly higher in the PH vs. the control group. The chronic infusion of adrenomedullin in rats with pulmonary hypertension increased the plasma levels of adrenomedullin to a value 94% greater than that of the control group and 55% greater than that of the untreated PH group. Chronic infusion of adrenomedullin significantly lessened the increase in right ventricular systolic pressure and the ratio of right ventricular weight to body weight seen after monocrotaline treatment. Histological examination revealed that adrenomedullin also attenuated the medial thickening of the pulmonary artery. These results suggest that chronic infusion of adrenomedullin attenuates the pulmonary hypertension and right ventricular hypertrophy seen in rats treated with monocrotaline.

Influence of physical exercise on human preferences for various taste solutions

The effects of physical exercise on preference for various sapid solutions was studied in 58 healthy university students. After 30 min of exercise using a bicycle ergometer at 50% VO2max (maximal oxygen uptake) intensity, a rating scale test on taste hedonic tone and the triangle test for taste absolute threshold were done. The test solutions were sucrose, NaCl, citric acid, caffeine and monosodium glutamate (MSG). Preference scale values for sucrose and citric acid increased after exercise, whereas the values for NaCl, caffeine and MSG were not changed. The absolute thresholds for all the sapid solutions did not differ for pre- and post-exercise. These findings indicate that in humans preference for sucrose and citric acid increase after physical exercise.

Effect of adrenomedullin on cAMP and cGMP levels in rat cardiac myocytes and nonmyocytes

The purpose of the present study was to determine if cardiac myocytes and nonmyocytes secrete adrenomedullin, to investigate the effects of adrenomedullin on cAMP and cGMP levels in cardiac myocytes and nonmyocytes, to study the effect of calcitonin gene-related peptide (CGRP) receptor antagonist CGRP-(8-37) and adrenomedullin-specific receptor antagonist, adrenomedullin-(22-52) on response to adrenomedullin and CGRP. Neonatal (days 1-2) cardiac myocytes and nonmyocytes were prepared from the ventricle of Wistar rats. Not only cardiac myocytes, but also nonmyocytes secrete almost equal amounts of adrenomedullin into the media. Both adrenomedullin and CGRP increased the cAMP levels, not the cGMP levels, both in the myocytes and nonmyocytes. In myocytes, CGRP-(8-37), almost completely inhibited the adrenomedullin- and CGRP-induced cAMP formation. In nonmyocytes, CGRP-(8-37) completely inhibited the cAMP levels induced by adrenomedullin and CGRP. More profound antagonistic effect of CGRP-(8-37) on cAMP levels induced by adrenomedullin was observed in nonmyocytes than in myocytes. In contrast, antagonistic effect of adrenomedullin-(22-52) for adrenomedullin-stimulated cAMP formation was considerably less potent than CGRP-(8-37) both in myocytes and nonmyocytes. Adrenomedullin-(22-52) did not affect the cAMP formation induced by CGRP either in myocytes or nonmyocytes. These results suggest that myocytes and nonmyocytes secrete adrenomedullin and that adrenomedullin increases cAMP levels possibly via different receptors in myocytes and nonmyocytes.

Inhibitory effect of shofu-san, a Japanese kampo medicine, on neutrophil functions in vitro

The effect of Shofu-san (TJ-22), an oral Japanese kampo medicine, on several inflammatory parameters of human neutrophils, including reactive oxygen species (ROS) generation, chemotaxis, and calcium concentration, [Ca2+]i in neutrophils was examined in vitro. In addition, ROS generated in a cell-free, xanthine-xanthine oxidase system was also assessed. The species investigated were superoxide radical anion (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (OH.). TJ-22 significantly decreased neutrophil-generated O2-, H2O2 and OH. in a dose-dependent manner. The medicine also markedly inhibited neutrophil chemotaxis and [Ca2+]i in neutrophils. In addition, three kinds of ROS generated in the cell-free system was reduced in the presence of TJ-22. Our results indicate that TJ-22 may exert an anti-inflammatory action by inhibiting the neutrophil functions and scavenging ROS, leading to a reduction in oxidative tissue injury.