Singlet oxygen (1 delta g) generation from coproporphyrin in Propionibacterium acnes on irradiation

Although singlet oxygen has been postulated to be a highly reactive and toxic intermediate, there has been no evidence of considerable generation of singlet oxygen in vivo level except for special cases. In this work, we firstly measured the near-infrared emission spectra corresponding to the O2(1 delta g) --> O2(3 epsilon g-) transition of singlet oxygen of cutaneous Propionibacterium acnes (P. acnes) porphyrin under laser excitation. A comparison of the singlet oxygen production of coproporphyrin, which is produced predominantly from P. acnes, with that of other photosensitizers revealed coproporphyrin to be a highly efficient singlet oxygen generator under ultraviolet light A irradiation on the skin. These results suggest that singlet oxygen can be generated on the skin surface from P. acnes porphyrin under ultraviolet irradiation and induce serious damage to the skin.

Expression of p53 protein in melanoma progression

p53, A tumor suppressor gene, has been documented as the most frequently mutated gene in human cancers including non-melanoma skin tumors. It has been controversial whether the p53 gene mutation plays a major role for melanoma genesis. To examine the role of p53 in human malignant melanoma carcinogenesis, we performed immunohistochemical analysis using anti-p53 antibodies (CM-1 and DO-7) in microwaved paraffin sections. When cases having more than 1% reactive cells were regarded as positive, immunohistochemical analysis revealed that in primary melanomas 14 of 51 (27%) were positive with CM-1 or 15 of 51 (29%) were positive with DO-7. Tumor thickness of primary melanomas in p53 positive cases was significantly thicker than that in p53 negative cases. In metastatic melanomas, 35 of 41 (85%) lymph node metastases were positive with either antibody and in skin metastases 16 of 28 (57%) lesions with CM-1 or 18 of 28 (64%) lesions with DO-7 were positive. The mean percentages of reactive cells were 2.3% in primary lesions and 4.9% in metastases. The incidence of positivity was significantly higher in metastases than primary lesions. In 10 cases examined, with both primary and metastatic melanoma, 3 cases were negative in both lesions and 1 case was positive in both lesions, while 6 cases were negative in the primary lesions and positive only in metastatic lesions. Four Spitz nevi, 6 dysplastic nevi and 11 common nevi were all negative. These data suggest that the expression of p53 protein may be a late event in melanoma progression.

Elcatonin raises levels of vasoactive intestinal peptide in human plasma

Elcatonin, used for treatment of hypercalcaemia, Paget's disease and osteoporosis, causes flushing of the face and hands. To determine whether this was because of increased levels of vasoactive intestinal peptide, which is known to induce vasodilation, the effect of elcatonin on the plasma levels of vasoactive intestinal peptide was studied in five healthy volunteers. After a single intramuscular administration of elcatonin (20 int units), peak plasma elcatonin levels (approx. 30 pg mL-1) were achieved 30 min after injection. Plasma vasoactive intestinal peptide concentrations rose similarly with peak levels of about 17 pg mL-1 after 30 min. Side-effects such as cutaneous flushing (most obvious in the face and hands) occurred to an extent dependent on the amount of elcatonin administered, and declined over 45 min in parallel with the fate of plasma vasoactive intestinal peptide. The side-effects of elcatonin, especially cutaneous flushing, seem to be closely connected with vasoactive intestinal peptide.

Myofibroblasts in the lamina propria of human semi-niferous tubules are dynamic structures of heterogeneous phenotype

Myofibroblasts of the lamina propria of human seminiferous tubules were studied in testes having normal or slightly reduced spermatogenesis by means of electron microscopy, confocal laser microscopy and immunocytochemistry. Myofibroblasts are large, flat individual cells braced in a network of microfibrils and collagen fibrils in the tubular wall. They are arranged in discontinuous cell layers with interposed layers of an extracellular matrix. Myofibroblasts of the lamina propria exhibit an unique cell shape with the peripheral cytoplasm split up in two or more layers. After FITC-phalloidin staining and by means of confocal laser microscopy, actin filaments of variable orientation are visible in their cytoplasm. The thickness and preferential direction of actin filaments differ in the outer and innermost cell layers. The myofibroblasts express both antigens of smooth muscle cells (alpha-smooth muscle actin, pan-actin, desmin, GB 42, smooth muscle myosin), and of connective tissue cells (vimentin, fibroblast surface protein). The variable expression of these antigens evidenced the existence of different phenotypes of myofibroblasts. Immunoreactivity for basic fibroblast growth factor and transforming growth factor beta as well as for components of the extracellular matrix indicate that these agents may be important for the phenotypic differentiation of the lamina propria cells. The detection of CNPase-and galactocerebroside-immunoreactivity in a number of lamina propria cells and some cells of the intertubular tissue gives rise to the hypothesis that components of the testicular tissue share some structural similarities with glia cells of the nervous system. Finally, immunoreactivities for the neuronal and endothelial nitric oxide synthase, soluble guanylyl cyclase, cyclic GMP, calmodulin, calcium-dependent protein kinase II and glutamate indicate that the contractility of myofibroblasts in the lamina propria of human seminiferous tubules may be in part modulated by the NO/cGMP-system.

Destruction of cholera toxin receptor on HeLa cell membrane using microbial endoglycoceramidase

The sensitivity of HeLa cells to cholera toxin decreased by Corynebacterium sp. endoglycoceramidase treatment. This endo-enzyme destroyed the cholera toxin receptor, ganglioside G(M1), on the cell surface membrane by liberating intact oligosaccharide from it, which was confirmed by the decrease of intracellular cAMP accumulation and the results of the analysis of released oligosaccharide with a combination of pyridylamination method and HPLC. Fluorescence microscopy using the immunofluorescence method revealed that the amount of cholera toxin attached to the cells decreased in endoglycoceramidase-treated cells. The enzyme acted on cellular glycosphingolipids without addition of any activator protein which is required by other similar enzymes. Corynebacterium endoglycoceramidase is a useful tool to elucidate the function of glycosphingolipids on the cell surface in situ.

Novel detection method of nitric oxide using horseradish peroxidase

Nitric oxide (NO) readily makes corresponding complexes not only with ferrous iron but also with ferric iron. However, NO-ferric complexes of many heme proteins were unstable, while horseradish peroxidase formed the very stable NO-ferric porphyrin complex with a shift of the Soret band of the absorption wavelength from 396.5 nm to 420.0 nm. The concentration of NO in aqueous media could be monitored by measuring the absorption changes, and the detection limit was 10 nM. The simple procedure is convenient for concentration determination of NO solution.

Nitric oxide release from kidneys of hypertensive rats treated with imidapril

To examine whether endothelial dysfunction in hypertension is reversible or not, we studied the effects of imidapril, an angiotensin-converting enzyme inhibitor, on nitric oxide release in stroke-prone spontaneously hypertensive rats (SHR) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. After a 4-week treatment with imidapril (1 or 10 mg/d SC) or vehicle, acetylcholine-induced vasodilation and nitric oxide release in the isolated kidneys were determined. Nitric oxide release was measured by a chemiluminescense assay. Imidapril lowered blood pressure in stroke-prone SHR in a dose-dependent manner. Untreated stroke-prone SHR exhibited significantly attenuated responses to acetylcholine (10(-8) mol/L) of both renal perfusion pressure (stroke-prone SHE 42 +/- 4% versus Wistar-Kyoto rats [WKY] 58 +/- 4% [mean +/- SE], P < .01) and nitric oxide release (stroke-prone SHR +7.6 +/- 2.1 versus WKY +29.7 +/- 9.7 fmol/min per gram of kidney wt, P < .01). Imidapril at 10 mg/d significantly increased acetylcholine-induced renal vasodilation and nitric oxide release in stroke-prone SHR (renal perfusion pressure, 56 +/- 3%; nitric oxide release, +27.1 +/- 6.4 fmol/min per gram of kidney wt; both P < .01 versus stroke-prone SHR treated with vehicle). On the other hand, imidapril neither decreased blood pressure nor changed nitric oxide release induced by acetylcholine in DOCA-salt hypertensive rats. Staining for endothelial nitric oxide synthase and brain nitric oxide synthase was clearly detected in the kidneys of both stroke-prone SHR and WKY, whereas staining intensity was weaker in DOCA-salt hypertensive rats. Inducible nitric oxide synthase immunoreactivity was barely noticeable in any type of rat. Thus, imidapril restored endothelial damage by pressure-dependent mechanisms. Most of the nitric oxide detected in the perfusate seemed to be derived from constitutive nitric oxide synthase.

E. coli endotoxin enhances cardiomyopathy in rats with chronic alcohol consumption

The purpose of the study was to show whether it was possible to produce alcoholic cardiomyopathy by short-term alcohol ingestion combined with an infinitesimally low endotoxin injection. Wistar rats were fed an alcoholic liquid diet according to the formula of Lieber and Decarli, and challenged with an injection of E. coli lipopolysaccharide (LPS) endotoxin (1.0 microgram/g body weight per day for ten weeks). After ten weeks alcohol diet combined with LPS challenge, light microscopical examination showed changes commonly seen in alcoholic cardiomyopathy such as hypertrophy, oedema and disarray of myofibers. By electron microscopy, degeneration of mitochondria and degeneration of myocardial fibers were observed, the latter showing disturbance of the myofibrilla arrangement and interstitial fibrosis. Rats on an alcoholic liquid diet and rats challenged with a single identical doses of LPS did not show characteristic histological findings of alcoholic cardiomyopathy. These results suggest that short-term alcohol ingestion combined with an infinitesimally low endotoxin injection experimentally produces alcoholic cardiomyopathy, and may support the idea that endotoxin plays an important role in the aetiology of alcoholic cardiomyopathy.

Peritubular myoid cells in the testis: their structure and function

Peritubular myoid cells, surrounding the seminiferous tubules in the testis, have been found in all mammalian species, but their organization in the peritubular interstitial tissue varies by species. In laboratory rodents, including rats, hamsters and mice, only one layer of myoid cells is seen in the testis. The cells in these animals are joined by junctional complexes as are epithelial cells. On the other hand, several cellular layers exist in the lamina propria of the seminiferous tubule in the human and some other animals. Myoid cells contain abundant actin filaments which are distributed in the cells in a species-specific manner. In the rat, the filaments within one myoid cell run both longitudinally and circularly to the long axis of the seminiferous tubule, exhibiting a lattice-work pattern. The arrangement of the actin filaments in the cells changes during postnatal development, and the disruption of spermatogenesis, such as cryptorchidism, seems to affect further the arrangement of the filaments. Other cytoskeletal proteins, including myosin, desmin/vimentin and alpha-actinin, are also found in the cells. Myoid cells have been shown to be contractile, involved in the transport of spermatozoa and testicular fluid in the tubule. Several substances (prostaglandins, oxytocin, TGF beta, NO/cGMP) have been suggested to affect the contraction of the cell, though the mechanisms of the contraction are still unknown. Recent in vitro studies have demonstrated that the cells secrete a number of substances including extracellular matrix components (fibronectin, type I and IV collagens, proteoglycans) and growth factors (PModS, TGF beta, IGF-I, activin-A). Some of these substances are known to affect the Sertoli cell function. Furthermore, it has been reported that myoid cells contain androgen receptors and are involved in retinol processing. Considering all this, it is evident that peritubular myoid cells not only provide structural integrity to the tubule but also take part in the regulation of spermatogenesis and the testicular function. Their precise roles, however, remain to be solved.

Measurement of 1268 nm emission for comparison of singlet oxygen (1 delta g) production efficiency of various dyes

Singlet oxygen generation from laser-excited photosensitive dyes was measured directly using a sensitive near-infrared emission spectrometer to monitor the O2(1 delta g)-->O2(3 sigma -g) transition at 1268 nm. The emission intensity was proportional to both the laser power and the concentration of the dyes. The singlet oxygen producing ability of the dyes was compared with that of eosin YS as a standard in methanol. The relative efficiencies of singlet oxygen generation were determined for rose bengal, erythrosine B, phloxine B and eosin YS as 2.39, 1.73, 1.38, 1.00, respectively, while uranine showed no emission in this spectral region. Using rose bengal, erythrosine B, phloxine B and eosin YS, the efficiency of singlet oxygen generation correlated with the photobleaching reaction rate of azo-dyes by these dyes, suggesting singlet oxygen to be a species responsible for causing the photobleaching of azo-dyes. The halogen substituent effect on the efficiency of singlet oxygen generation from laser-excited photosensitive dyes was also examined systematically.

[A case of hemolytic uremic syndrome after cadaveric renal transplantation]

We report a cadaveric renal transplant recipient suffering from hemolytic uremic syndrome (HUS). A 46-year-old woman received a cadaveric renal transplantation on February 16, 1994. From the 20th postoperative day, anemia, thrombocytopenia and deterioration of graft function occurred. Graft biopsy on the 20th postoperative day indicated HUS by microthrombotic arterioglomerulopathy. Plasma exchange and 15-deoxyspergualin improved her graft function. From these clinicopathological findings, we conclude that she had HUS caused by acute humoral rejection.

Epitope analysis of HLA-DR-restricted helper T-cell responses to Der p II, a major allergen molecule of Dermatophagoides pteronyssinus

T-cell epitopes of Der p II, a major allergen of Dermatophagoides pteronyssinus, were analyzed by using human T-cell clones. We tested 38 cloned T cells from two Japanese patients with allergic rhinitis, and identified at least two peptides (K33-T47 and I58-C73) as helper T-cell epitopes. The former epitope was shown to be restricted by HLA-DRB1*1502, and the latter by HLA-DRB1*0405, both of which are typical Japanese HLA-DR alleles, suggesting that those T-cell epitopes might be important for the onset of house-dust mite allergy in the Japanese population. We prepared 15 analog peptides of the HLA- DRB1*1502-restricted 15-mer peptide. Of those 15 residues, five (F35, L37, A39, F41, and E42) were critical for the epitope activity, and three residues (F35, A39, and E42) seemed to be included in anchor motifs for HLA-DRB1*1502. The epitope peptide was also recognized by HLA-DRB1*1502-positive healthy donors; however, only allergic T cells showed Th2 functions. Antigen-presenting cells of nonallergic donors were able to activate allergic T cells to express Th2 function. This seemed to suggest that antigen recognition of T cells, as well as additional unknown factors which promote Th2, rather than Th1, responses, might be important for the onset of house-dust mite allergy.

Experimental studies on postmortem diffusion of ethanol-d6 using rats

In an investigation of postmortem ethanol diffusion deuterium-labeled ethanol-d6 was instilled by peroral gavage immediately after death by CO into the stomach of rat carcasses which were subsequently kept for 12-72 h at 5 or 30 degrees C. The heart blood, abdominal fluid and several tissues were collected and analyzed by head space gas chromatography-mass spectrometry. Rat carcasses showed no macroscopic changes until at least 72 h at 5 degrees C, and 12 h at 30 degrees C. At 30 degrees C, slight macroscopic change was observed after 24 h, moderate change after 48 h and marked change after 72 h. In the abdomen ethanol-d6 diffused gradually into neighboring organs (hepatic left lobe, left kidney and spleen) at 5 degrees C, with ethanol-d6 reaching a peak concentration of 0.75-2.38 mg/g at 24 h. At 30 degrees C, ethanol-d6 was also detected in neighboring organs and reached a peak concentration of 1.06-2.61 mg/g at 12 h. Thereafter, the ethanol-d6 concentration in the liver, kidney and spleen decreased, with concentrations ranging from 0.30 to 0.61 mg/g at 30 degrees C and 0.05 to 1.47 mg/g at 5 degrees C at 48 h. In the femoral skeletal muscle, ethanol-d6 was not detected until 24 h or more storage at 30 degrees C and never detected at 5 degrees C. In the brain and the organs in the thoracic cavity ethanol-d6 was detected after 12 h or more at 5 or 30 degrees C. Comparison of these results of direct peroral gastric instillation with those when ethanol-d6 was injected into the stomach through a laparotomy incision suggest that the brain and thoracic cavity changes were a result of diffusion from the mouth and esophagus. After 24 h at 30 degrees C, the postmortem ethanol production (0.33-0.85 mg/g) was comparable to those in previous reports. These results indicate that the assessment of ethanol concentration in the heart blood and organs in autopsy cases must be carefully conducted in comparison with the alcohol content of the stomach.

Postmortem degradation of administered ethanol-d6 and production of endogenous ethanol: experimental studies using rats and rabbits

Deuterium-labeled ethanol-d6 was employed to study the metabolism and postmortem change of ethanol in putrefied organ tissues. First, 4 ml/kg body weight of 25% (w/v) solution of ethanol-d6 was administered orally to each of 15 rats. The heart blood and organs were collected 15-90 min after the administration and the ethanol-d6 was analyzed by head space gas chromatography/mass spectrometry. The ethanol-d6 concentration in the organ tissues reached its maximum at 15 min after the administration and then gradually declined, showing the same pattern as human ethanol metabolism. Ethanol-d6 (3 ml of the same solution/kg body weight) was injected into the vein of a rabbit's ear (total of 12 rabbits). The rabbit was killed with carbon monoxide 30 min after the administration and the carcass was allowed to stand for 1-4 days at 30 degrees C in a moist chamber. The concentration of ethanol-d6 decreased moderately. Postmortem ethanol and 1-propanol concentrations, in contrast, showed marked increases 2.5 days and more after sacrifice in line with the degree of putrefaction of each organ tissue including skeletal muscle. This suggests the postmortem activation of micro-organism activity. These results indicate that ethanol concentrations in cadaver tissues must be carefully assessed with due consideration of postmortem degradation and production.

Self-organization of the velocity selectivity of a directionally selective neural network

We first present a mathematical analysis of the relation between the parameters and the behavior of the basic module in the proposed neural network model for visual motion detection. Based on the analytical results, a learning rule is put forth that can develop velocity selectivity of directionally selective cells in the basic module. The learning rule is furthermore introduced into the total model called a 'mass model', which is constructed with many basic modules. Numerical simulation results showed that each basic module in the mass model learned in a self-organizing manner to acquire selectivity for the velocity of an input stimulus. The proposed learning rule would be plausible in the actual nervous system in that it is simple and can be described with only local information.

Yersinia pseudotuberculosis in China

Thirty strains of Yersinia pseudotuberculosis were isolated from rabbits (17 strains), wild rats (9 strains) and house rats (4 strains) in China between 1990 and 1993. The biochemical properties of these isolates were identical with those of Y. pseudotuberculosis and no special characteristics were found in these strains. Serologically, serogroups 4b and 5b were identical to isolates found in Japan, and a new serogroup 1c and unclassified strains have also been detected. The existence of virulence-associated properties were different among strains. The pYV plasmid was detected from 6 strains of 30 isolates. This report documents the presence of Y. pseudotuberculosis in China, providing important epidemiological information.

[Clinical statistics of 67 cadaveric renal transplantation at the Department of Urology, Kinki University School of Medicine]

A statistic survey was made on the patients undergoing cadaveric renal transplantation between June, 1980 and December, 1993. The total number of patients was sixty-seven. The number of patients per year increased annually. The graft survival rate was 73.8% at 1 year and 63.1% at 5 years. Some transition was seen in immunosuppressive regimens using cyclosporin.

Cyclin D and retinoblastoma gene product expression in actinic keratosis and cutaneous squamous cell carcinoma in relation to p53 expression

Abnormality of the molecules regulating the cell cycle has been shown to lead cells to transformation. Recently, overexpression of cyclin D protein, one of the G1 cyclins, and the abnormality of the retinoblastoma gene have been found in various human cancers. We analyzed the expression of cyclin D, retinoblastoma gene product (pRB) and p53 in actinic keratoses (AKs) and cutaneous squamous cell carcinomas (SCCs) by immunohistochemistry to elucidate the role of these molecules in keratinocyte carcinogenesis. In the normal epidermis, a few cyclin D positive cells were seen mainly at the basal layer. In 11 seborrheic keratoses, no overexpression of cyclin D was observed. Twelve of 26 AKs (46%) and 27 of 45 SCCs (60%) showed cyclin D overexpression. A few pRB positive cells were seen in the basal layer and in the suprabasal spinous layer of the normal epidermis. An abnormality of pRB, loss of expression, was seen in 2 of 26 AKs (8%) and 7 of 45 SCCs (16%). p53 protein was positive in 12 of 26 AKs (46%) and 24 of 45 SCCs (53%). Forty-five SCCs examined were divided into 22 ultraviolet (UV)-related SCCs and 23 UV-unrelated SCCs. Though UV-related SCCs showed a significantly higher incidence of p53 positivity, as previously reported by us, no significant difference in cyclin D overexpression and loss of the pRB expression was observed between UV-related and UV-unrelated SCCs. These results suggest that cyclin D overexpression is frequently involved in keratinocyte carcinogenesis and that this is an early event, as well as p53 abnormality. In addition, abnormality of the retinoblastoma gene is also related to epidermal cell carcinogenesis, though the frequency is relatively low.

Distribution of the basic fibroblast growth factor and its receptor gene expression in normal and degenerated rat intervertebral discs

STUDY DESIGN

Using a rat spondylosis model, the distributions of cells expressing the basic fibroblast growth factor and its receptor were investigated in normal and degenerated intervertebral discs. Cell-proliferating activity in degenerated discs was also assessed.

OBJECTIVES

This study was conducted to determine whether basic fibroblast growth factor is related to intervertebral disc degeneration.

SUMMARY OF BACKGROUND DATA

Basic fibroblast growth factor stimulates proliferation and matrix synthesis of cultured intervertebral disc cells.

METHODS

Immunohistochemistry and in situ hybridization histochemistry were conducted to detect cells with basic fibroblast growth factor-like immunoreactivity and fibroblast growth factor receptor messenger RNA, respectively. Cell-proliferating activity was evaluated by AgNOR staining.

RESULTS

In degenerated discs, round chondrocytes with basic fibroblast growth factor-like immunoreactivity and fibroblast growth factor receptor messenger RNA are scattered instead of spindle-shaped cells in the normal anulus (normal anular cells), which are devoid of basic fibroblast growth factor-like immunoreactivity and fibroblast growth factor receptor messenger RNA. The proliferating activity of these chondrocytes is suggested to exceed that of normal anular cells.

CONCLUSION

Basic fibroblast growth factor is suggested to promote proliferation of chondrocytes in degenerated discs in an autocrine or paracrine manner. Basic fibroblast growth factor may be related to intervertebral disc degeneration as a proliferation-stimulating factor of chondrocytes that replace normal anular cells during disc degeneration.