Maltal binding mechanism and a role of the mobile loop of soybean beta-amylase

The inhibition of hydration of maltal (alpha-D-glucopyranosyl-(1-->4)-2-deoxy-D-glucal) catalyzed by soybean beta-amylase with 4-O-alpha-D-glucopyranosyl-(1-->4)-1-deoxynojirimycin (GDN) was investigated at 25 degrees C and at pH 5.4. As the concentrations of GDN used were comparable to that of the enzyme, Henderson's treatment was applied to this system. It was found that two maltal molecules bind to the enzyme according to a random mechanism and GDN inhibits the hydration of maltal competitively at subsites 1 and 2, and noncompetitively at the other site. On the basis of this result, it was inferred that the role of the mobile loop of this enzyme is to create a convenient catalytic environment for the hydration, and the closing of the active site by the mobile loop is induced by the binding of maltal.

Effect of the hydroxyl radical on fibroblast-mediated collagen remodelling in vitro

1. It has been reported that free radicals prevent wound healing. However, the mechanism of this effect is not yet clear. We attempted to clarify the influence of hydroxyl radicals on wound healing in vitro. 2. We used an ascorbate-copper ion system (ACS) to produce hydroxyl radicals in accordance with variables of time elapsed and concentration of copper ion. The effects of hydroxyl radical on fibroblast-mediated collagen remodelling, cell viability, the functions of fibroblasts and collagen fibrils were studied. 3. With a copper ion concentration of 100 mumol/L ACS significantly reduced contraction, while 10 mumol/L stimulated contraction. Hydrogen peroxide (H2O2) was employed in observing these findings. ACS did not influence cell viability, the expression of alpha 2 beta 1 integrin and cellular fibronectin, or the cytoskeletal organization of fibroblasts involving actin until 3 h. A concentration of ACS at 10 mumol/L of copper ion induced the polymerization of collagen after 30 min, while ACS at 100 mumol/L induced collagen degradation; this finding was also established by using H2O2. Collagen reduced the amount of formaldehyde produced by trapping hydroxyl radical with dimethyl sulfoxide. 4. Our findings suggest that collagen is denatured by scavenging the hydroxyl radical before fibroblasts are damaged, so that the radical may influence the remodelling of collagen.

Chain conformation of deacetylated beijeran calcium salt

A well-defined X-ray fiber diffraction pattern was obtained from a stretched film of the calcium salt of a new uronic acid containing polysaccharide designated as beijeran in the deacetylated form, poly[-->3)-alpha-D-GalUA-(1-->3)-beta-L-Rham-(1-->3)-alpha-D -Glc-(1-->]. The oriented film showed no diffraction spots, indicating it to be amorphous. However, when annealed at high temperature, the film exhibited high crystallinity. All the visible reflections could be indexed in terms of a monoclinic unit cell with the following dimensions: a = 1.297; b = 1.676; c (fiber axis) = 2.509 nm; and gamma = 106.50 degrees. The length of the fiber axis and the absence of meridional reflections at any odd layer line indicate that an extended two-fold helical conformation was made up of two trisaccharide residues.

Plasma nitric oxide levels in pregnant patients with preeclampsia and essential hypertension

Nitric oxide (NO) production may be an important causal factor in hypertensive disorders during pregnancy. The plasma concentrations of NO2-(+) NO3-, stable metabolites of NO, were measured in 70 nonpregnant women, 323 normotensive pregnant women, 23 pregnant patients with preeclampsia, and 7 pregnant patients with essential hypertension. The normotensive women had higher plasma concentrations (30.0 +/- 0.6 mumol/l) than nonpregnant women (18.3 +/- 1.0 mumol/l; p < 0.0001). The plasma concentrations in the patients with preeclampsia (45.6 +/- 2.3 mumol/l) were higher than in the normotensive women (30.3 +/- 1.0 mumol/l; p < 0.0001) and were correlated with the systolic blood pressure (r = 0.442; p < 0.05). However, pregnant patients with underlying essential hypertension had significantly lower plasma concentrations (19.1 +/- 3.0 mumol/l; p < 0.005). These findings suggest that NO contributes to maternal vasodilation, the maintenance of uterine quiescence, and the pathogenesis and clinical features of hypertensive disorders during pregnancy.

Progressive systemic sclerosis associated with multiple mononeuropathy

BACKGROUND

Progressive systemic sclerosis (PSS) is a chronic connective tissue inflammatory disease which commonly attacks the skin and the visceral organs, but rarely the peripheral nervous system.

OBJECTIVE

The aim of this study was to investigate PSS accompanied by peripheral neuropathy clinically, electrophysiologically and pathologically from a sural nerve biopsy.

METHODS

Two women suffering from PSS but without any other collagen disease were studied. Both patients developed peripheral neuropathy with multiple mononeuropathy of the limbs, and in one woman, in the trunk as well.

RESULTS

A biopsy of the sural nerve revealed axonal and myelin segmental degeneration, loss of large myelinated fibers and an increase of collagen fibers, but there was no evidence of vasculitis. An electron microscopic examination revealed degenerated axons, disrupted myelin sheaths and multilayered basal lamina in the capillaries.

CONCLUSION

Mononeuropathy in PSS suggests that ischemic neuropathy may be related to the immune-mediated vasculopathy.

[Basic and clinical studies of pazufloxacin on infectious enteritis research group of T-3761 on infectious enteritis]

A clinical study was carried out on pazufloxacin (PZFX) in 137 patients including shigellosis, Salmonella enteritis, enteropathogenic Esherichia coli enteritis and cholera, and carriers of these pathogens. Antibacterial activity of PZFX against clinical isolates, fecal concentration of PZFX and effects of PZFX on fecal microflora were also investigated. The overall clinical efficacy rate was 97.2%. The bacteriological efficacy rates were 98.2% against Shigella spp., 81.8% against Salmonella spp., 50% against Vibrio cholerae O1, and 100% against E. coli, V. parahaemolyticus, Aeronomas spp., Plesionomas shigelloides and V. cholerae non-O1, respectively. Side effect (epigastralgia) was observed in 1 of 130 cases (0.8%). The rate of abnormal laboratory findings was 11.2% (11/98). These were mainly elevation of GOT and/or GPT and increased eosinophils. The clinical usefulness rate was 95.2%. The MIC90 values of PZFX against Shigella spp., Salmonella spp. and E. coli were 0.025, 0.025 and 0.025 micrograms/ml, respectively. The results of fecal drug concentration and the effects on fecal microflora in one patient were compatible with those obtained in healthy volunteers.

Eosinophils as a potential source of platelet-derived growth factor B-chain (PDGF-B) in nasal polyposis and bronchial asthma

Tissue remodeling in bronchial tissues from asthmatics as well as in nasal polyp (NP) tissues includes sub-basement membrane deposition of collagen, stromal deposition of extracellular matrix protein, and hypertrophy/hyperplasia of airway smooth muscle cells, which are relevant to the cellular and molecular events induced by platelet-derived growth factor (PDGF). Therefore, we investigated the localization of mRNA and protein of PDGF-B chain (PDGF-B) in NP tissues and bronchial tissues from mild and severe asthmatics by in situ hybridization and immunohistochemistry, respectively. Cells expressing PDGF-B mRNA were found in all nine NP tissues and in bronchial tissues from 2 of 6 normal subjects, 2 of 5 mild asthmatics, and all of 6 severe asthmatics examined. The vast majority of cells expressing PDGF-B mRNA were eosinophils in NP (99.7 +/- 0.2%, mean +/- SD) and asthmatic bronchial tissues (75.0 and 77.8% in mild asthma, and 92.7 +/- 8.1% in severe asthma), but no cells expressing PDGF-B mRNA were eosinophils in normal bronchial tissues. The number of cells expressing the gene in severe asthma tissues (122.3 +/- 32.2/mm2) was similar to that in NP tissues (152.8 +/- 73.9/mm2) and greater than that in mild asthma tissues (4.7 +/- 7.6/mm2, P < 0.01), which was not significantly greater than that in normal bronchial tissues (3.4 +/- 5.2/mm2). Furthermore, we detected immunolocalization of PDGF-B in NP tissues and in asthmatic bronchial tissues. The eosinophils purified from peripheral blood were demonstrated to express PDGF-B gene transcript and immunoreactivity after stimulation with A23187.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of minisatellite instability with c-myc amplification and K-ras mutation in methylcholanthrene-induced mouse sarcomas

Instability of microsatellite sequences are frequently found in human tumors. In addition, minisatellite sequences, another group of highly unstable sequences, serve as sensitive markers of genetic instability. We have studied minisatellite instability in methylcholanthrene-induced mouse sarcomas. These sarcomas frequently carry the amplified c-myc gene. Seven sarcomas without the amplification and seven others with the amplification were selected randomly. Regardless of the state of the c-myc gene amplification, these sarcomas exhibited a varying degree of transplantability in syngeneic mice. The hypervariable mouse minisatellite locus Ms6hm was found to be highly unstable, specifically among sarcomas with the amplified c-myc gene. However, chromosome instability, as analyzed by micronucleus assay, was observed similarly for two groups of sarcomas. In addition, transversion of G to C and A to T was detected at the K-ras gene in four of the seven sarcomas with the amplified c-myc gene, and these mutations are thought to be induced directly by methylcholanthrene. Thus, concomitant occurrence was observed for three seemingly unrelated mutations, amplification of the c-myc locus, point mutation of the K-ras gene, and instability at the hypervariable mouse minisatellite locus. The present study indicates a possible involvement of K-ras mutation and c-myc amplification in induction of genetic instability in methylcholanthrene-induced mouse sarcomas.

Microdialysis measurement of intracerebral somatostatin in the goat

A microdialysis sampling technique for the intracerebral measurement of somatostatin (SS) in extracellular fluid was examined in the goat. The microdialysis probe (70-mm shaft, 0.5 mm outer diameter) contained at its tip a 4-mm length of copolymer dialysis membrane (20 kDa cut-off). Artificial cerebrospinal fluid (artificial CSF) was pumped through the probe tip at a rate of 4 microliters/min with a batter-driven syringe pump, and effluent fractions of dialysate (120 microliters) were collected every 30 min. An in vitro recovery test showed that changes in the SS concentration in dialysate were highly correlated (r = 0.95, P < 0.01) with those in the external medium, and the relative recovery averaged 2.0%. As a validation for in vivo microdialysis, trails were conducted with conscious behaving goats wherein the inflow dialysate was changed transiently from artificial CSF with low potassium (2.5 mM) to a solution of 300 mM KCl. Potassium-induced depolarization around the probe tip located in the preoptic area and in the hypothalamus induced an increase in SS concentrations in dialysate at each location. In the most remarkable response, the concentrations of SS were increased 6-fold and 11-fold in the first and second 30-min fractions, respectively, compared with prepotassium concentrations. These results suggest that intracerebral SS levels in extracellular fluid could be estimated from conscious behaving goats by the use of our intracerebral microdialysis system.

[clinical study of balofloxacin on infectious enteritis and assessment of the fecal drug concentration and intestinal microbial flora in patients with inpatients with infectious enteritis. Research group of balofloxacin on infectious enteritis]

The efficacy, safety and usefulness of balofloxacin (BLFX) for patients with acute infectious enteritis and the carriers mainly shigellosis, were investigated. The drug was administered at a daily dose of 200 mg twice a day for 3 days to patients with cholera, 7 days to patients with Salmonella enteritis and 5 days to patients with other conditions of infectious enteritis including shigellosis; 1. The efficacy was analyzed in 89 of the 135 patients who received the administration (43 patients with shigellosis, 14 with Salmonella enteritis, 8 with enteropathogenic/ enterotoxigenic Escherichia coli enteritis, 3 with cholera, 7 with enteritis with other pathogenic bacteria, 6 with polymicrobial infectious enteritis and 8 with acute enteritis that was pathogen-negative). 2. In patients bearing symptoms and who thus could be analyzed for drug efficacy, the drug was markedly effective or effective 50/52 (96.2%). 3. Bacteriologically, the drug was effective for Shigella spp. in 41 (100%) of 41, Salmonella spp. in 12 (85.7%) of 14, and enteropathogenic/enterotoxigenic Escherichia coli in 8 of 8 cases. 4. Adverse effects were seen in 5/133 patients (3.8%) receiving the drug, including two cases of skin eruption, one of the numbness of the hands, one of oral aphtha, and one of nausea. In patients for whom laboratory findings were available, 20/115 (17.4%) showed abnormalities, mainly elevations of GOT and/or GPT, but these were slight. 5. In terms of subjective reports of usefulness, 51/82 (62.2%) were markedly satisfied, and 73/82 (89.0%) were either satisfied or markedly satisfied. 6. The influence of administration of BLFX on fecal concentration and intestinal microbial flora was investigated in 2 patients with acute infectious enteritis. Results approximately equivalent to such flora levels in healthy subjects were obtained. These results suggest that BLFX is highly useful for infectious enteritis such as that caused by shigellosis.

Association between elevated plasma granulocyte colony-stimulating factor and the degree of surgical stress in patients undergoing gastrointestinal surgery

To characterize the changes in perioperative plasma granulocyte colony-stimulating factor (G-CSF) and analyze the effect of surgical stress on its kinetics, 41 patients undergoing gastrointestinal surgery with varying degrees of surgical stress were examined. The plasma levels of G-CSF significantly increased immediately after the operation, probably in response to surgical injury. This elevation was much higher in the 15 esophagectomy patients, at 883 +/- 300 pg/ml on postoperative day (POD) O, than in the 14 gastrectomy patients, with a value of 233 +/- 151 on POD O, (P < 0.01) or in the 12 cholecystectomy patients, with a value of 64 +/- 41 on POD 1 (P < 0.01). These findings led us to conclude that G-CSF levels increase significantly in the immediate postoperative period and are most likely associated with the degree of surgical stress. In addition, we studied the priming effect of G-CSF on polymorphonuclear leukocytes (PMNs). G-CSF enhanced PMN superoxide anion (O2-) production and luminol-dependent chemiluminescence (CL) induced by opsonized zymosan in a dose-dependent manner. A significant enhancement was seen in the G-CSF level (1 ng/ml) which was almost the same as the maximum G-CSF level in the esophagectomy patients. Furthermore, postoperative PMN activation occurred after the elevation of plasma G-CSF. Thus, we propose that elevated G-CSF may act as one of the mediators which activate PMN function postoperatively.

"Malignant Spitz nevus" in a 2-year-old Japanese child

Smith et al. (1989) have reported a variant of Spitz's nevus with histological atypical features. Despite local lymph node metastases, further metastases were not observed. They proposed the name "malignant Spitz nevus" for this variant. A 2-year-old Japanese girl had a large nodule (27 x 17 mm) surrounded by an indurated erythema over the Achilles tendon. Histologically, it proved to be a melanocytic lesion resembling spindle cell and epithelioid cell nevus (Spitz's nevus) with unusual features; the tumor extended deep into the subcutis, and the mitotic figures deep into the tumor, together with prominent lymphatic vessel invasion by melanocytes. Thus the tumor was aptly termed "malignant Spitz nevus". Flow cytometric analysis of the DNA content revealed a diploid pattern. The child is well 5 years after a wide resection of the tumor. The diploid pattern of the DNA content as well as the good prognosis could support the idea that "malignant Spitz nevus" fits within the spectrum of Spitz's nevus.

Comparison of 99Tcm-pyrophosphate, 201T1 perfusion, 123I-labelled methyl-branched fatty acid and sympathetic imaging in acute coronary syndrome

Among a group of patients (n = 15) with acute coronary syndrome, the results of using two new myocardial radiopharmaceuticals--123I-labelled 15-(p-iodo-phenyl)-3,R,S-methylpentadecanoic acid (BMIPP) and 123I-meta-iodobenzyl guanidine (MIBG)--were compared with dual 201Tl/99Tcm-pyrophosphate (Tl-PYP) imaging using single photon emission tomography (SPET). Defect scores were evaluated on a segment-by-segment basis for a total of 270 segments. For the 201Tl, BMIPP, and early and delayed MIBG studies, the mean (+/- S.D.) sums of defect scores were 9 +/- 8, 18 +/- 9, 22 +/- 12 and 29 +/- 9, respectively, revealing significantly higher scores for BMIPP and MIBG than 201Tl (P < 0.005). This was the case irrespective of various functional conditions, such as successful recanalization, failure of coronary angioplasty or restenosis. The culprit coronary artery was best identified using BMIPP, while MIBG SPET showed the most extensive defects. Normal perfusion with decreased BMIPP and MIBG uptake was frequently observed and associated with hypokinesis. 123I-BMIPP and MIBG are more sensitive for the detection of damaged myocardium, and the difference between perfusion and metabolism seems to reflect myocardial stunning.

Lichen planus pemphigoides: identification of 180 kd hemidesmosome antigen

We describe a man with lichen planus pemphigoides. Direct immunofluorescence studies of peribullous skin showed linear deposition of IgG and C3 in the basement membrane zone. Indirect immunofluorescence studies disclosed circulating anti-basement membrane zone antibodies. Immunoelectron microscopy demonstrated binding of antibodies to the hemidesmosomes and lamina lucida. The patient's serum defined only the minor bullous pemphigoid antigen with a molecular weight of 180 kd. These findings suggest the coexistence of lichen planus and bullous pemphigoid in lichen planus pemphigoides.

Pemphigoid nodularis: a case with 230 kDa hemidesmosomes antigen associated with bullous pemphigoid antigen

We report a 73-year-old woman with typical clinical, histological and immunofluorescence features of pemphigoid nodularis. Direct immunofluorescence studies of prurigo nodularis-like lesions and peribullous skin showed the linear deposition of IgG and C3 at the basement membrane zone. Circulating IgG against the basement membrane was also detected by indirect immunofluorescence. The serum from the patient was shown to contain the autoantibody against 230 kDa hemidesmosomal antigen associated with bullous pemphigoid antigen.

Effects of macrophage depletion on the induction of histidine decarboxylase by lipopolysaccharide, interleukin 1 and tumour necrosis factor

1. Our previous work has shown that injection into mice of lipopolysaccharide (LPS) and the cytokines interleukin 1 (IL-1) and tumour necrosis factor (TNF) induces histidine decarboxylase (HDC), the enzyme forming histamine, in various tissues such as liver, lung, spleen and bone marrow, but not in the blood. The induction of HDC also occurs in nude mice and mast cell-deficient mice. On the other hand, haematopoietic cytokines such as IL-3, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF) only induce HDC in the haematopoietic organs, i.e. bone marrow and spleen. In the present study, the effect of macrophage depletion on the induction of HDC was examined. 2. On day 1 after a single intravenous injection of a macrophage depletor (liposomes encapsulating dichloromethylene diphosphonate, which is toxic when ingested into macrophages), macrophages were almost completely depleted in the liver and reduced by about 50% in the spleen and bone marrow, but not significantly affected in the lung. On day 3, the degrees of the depletion were similar to those of day 1. In the spleen, macrophages were depleted in the red pulp, and there was a structural destruction. 3. In macrophage-depleted mice, the induction of HDC by LPS, IL-1 alpha or TNF-alpha was not impaired in the liver, and was potentiated in the lung and bone marrow. The induction of HDC was decreased only in the spleen at day 3. 4. HDC was not induced by LPS in the spleen of the adult rat, which is correspondingly inactive in haematopoiesis.5 These results indicate that the major cells in which HDC activity is induced in response to LPS, IL-1 and TNF are not circulating granulocytes, circulating monocytes, T cells derived from thymus, mast cells or phagocytic macrophages. Based on these results, we discuss the possibility that the major cells in which HDC was induced in non-haematopoietic and haematopoietic organs were endothelial cells and haematopoietic precursor cells respectively.

Diminished heat shock protein 70 mRNA induction in aged rat hearts after ischemia

Vulnerability of aged hearts to ischemia may be due to defects in protective mechanisms provided by heat shock proteins (HSPs). To determine whether there is a defect in the induction of HSPs by ischemia in old hearts, HSP72 and HSP73 (inducible and constitutive HSP70, respectively) mRNA induction was examined in young (2-mo-old; n = 36) and old (18-mo-old; n = 32) rat hearts. Transient (10- or 20-min) ischemia was applied by tightening a snare placed around left coronary arterial branches 3 days before examination to avoid the effect of operation on induction. HSP72 mRNA was induced markedly in young hearts after 10-min ischemia, peaked at 2 h, but was induced only slightly in old hearts. HSP73 mRNA was also induced in young hearts, peaked at 4 h, but was not induced in old hearts. The mRNAs were markedly induced in old hearts as well after 20-min ischemia, which was accompanied by the induction of HSP72 protein. Thus the age-related modulation of HSP72 and HSP73 mRNAs suggests a defective sensing mechanism for ischemia in old hearts.

[Basic and clinical studies of fleroxacin on infectious enteritis. Research Group of AM-833 on infectious enteritis]

A clinical study was conducted on fleroxacin (FLRX) in 143 patients and carriers with infectious enteritis (shigellosis, Salmonella enteritis, Campylobacter enteritis, pathogenic Escherichia coli enteritis, Vibrio parahaemolyticus enteritis, cholera, multiple bacterial infections, pathogen-negative enteritis). Furthermore, its antibacterial activity against clinical isolates, fecal concentration and effect on fecal microflora were conducted. FLRX was administered orally in doses of 200 mg once a day (200 mg group) or 300 mg once a day (300 mg group) for 3 days to cholera, for 7 days to Salmonella enteritis and for 5 days to the other infectious enteritis. The clinical efficacy rates were 100% in both the 200 mg and 300 mg groups. The bacteriological efficacy rates were 100% against Shigella spp., Salmonella spp., pathogenic E. coli, V. parahaemolyticus and V. cholerae O1, and 63.6% against Campylobacter spp. in the 200 mg group. The rates of the 300 mg group were 93.3% against Shigella spp., and 100% against Campylobacter spp. and pathogenic E. coli. As adverse effects, skin rash was observed in 1 case each in both groups (1.1%, 2.1%). Abnormal laboratory findings consisted of 1 case of increased eosinophils and 1 case of elevated GOT and GPT levels in the 200 mg group (2.8%), and 1 case of elevated GPT in the 300 mg group (2.9%). The clinical usefulness rates were 92.9% and 93.3% in the 200 mg and 300 mg groups, respectively. Antibacterial activity was somewhat inferior to that fo ciprofloxacin and equal to or better than that of norfloxacin, demonstrating MIC90 values against Shigella spp., Salmonella spp., pathogenic E. coli, V. parahaemolyticus and Campylobacter spp. of 0.1, 0.2, 0.1, 0.2 and 0.78 micrograms/ml, respectively. Peak fecal concentrations of the drug were 49.0 micrograms/g and 274.4 micrograms/g in the 200 mg group, and 43.3 micrograms/g and below the detection limit (5.0 micrograms/g) in the 300 mg group. With respect to fecal microflora (4 cases), a decrease in Enterobacteriaceae was observed in 3 cases during dosing. But this change showed a tendency to recover after completion of dosing. No effects were observed on anaerobic bacteria.

Significance of tubuloreticular structures forming in Daudi cells cultured with sera from mothers bearing infants with neonatal lupus erythematosus

It is known that infants with neonatal lupus erythematosus (NLE) may be born to mothers whose sera are positive for the anti-Ro/SSA antibody. However, women who have this antibody do not always give birth to children with NLE. We have demonstrated tubuloreticular structures in vascular endothelial cells in the skin lesions of infants with NLE. Tubuloreticular structures could no longer be detected at the site of the lesions once the annular erythema had resolved, and the anti-Ro/SSA antibody test had become negative. The probability of a child being born with NLE was assessed by observing whether tubuloreticular structures were formed in Daudi cells cultured with sera from eight mothers who were anti-Ro/SSA antibody positive. Tubuloreticular structures formed in Daudi cells cultured with sera from four mothers who bore infants with NLE, but not in Daudi cells cultured with sera from four other mothers who bore normal infants. These results suggest that women who are positive for the anti-Ro/SSA antibody have a higher risk of bearing infants with NLE if tubuloreticular structures are formed in Daudi cells cultured with sera from these women, whereas this risk is lower if tubuloreticular structures do not develop in Daudi cells.

Identification of programmed cell death in normal human skin tissues by using specific labelling of fragmented DNA

Programmed cell death (PCD) in normal human skin tissues was studied by using in situ specific labelling of fragmented DNA. This labelling method clearly stained the nuclei of Henle's layer in the bulb of the anagen hair follicle in serial sections, and the nuclei of the inner root sheath cuticle cells and Huxley's layer cells showed positive staining in the upper part of the hair follicles. This staining pattern was consistent with the sequence of keratinization in the three layers. The nuclei of differentiated cells located at the centre of the sebaceous glands, and those of the granular keratinocyte layer, were also stained. These findings suggest that PCD might play a key role in the terminal differentiation of the epidermis and epidermal appendages.

Diagnostic approach to autoimmune blistering diseases using immunoblotting with chemiluminescence

Autoantibodies in sera from patients with autoimmune blistering diseases were detected by immunoblotting with chemiluminescence. This method provided the high sensitivity in the detection of autoantibodies against human epidermal extract. It was useful for detecting low titers of autoantibodies, and identifying small amounts of autoantigens in antigen extracts.

Responses to hemodynamic stress in the aged heart

In aged individuals the incidence of heart failure is higher than in younger subjects. Ischemic events are also common in the aged heart because of changes in the coronary vasculature and myocytes caused by aging. Adaptational responses to increased hemodynamic overload and to ischemia in the aged heart are discussed at the molecular, cellular and organ levels. One characteristic of the aged heart is a limited capacity for adaptation with hypertrophy to increased mechanical load. This age-related attenuation of the hypertrophic response may be attributed to the diminished induction of proto-oncogenes such as c-fos, c-myc and c-jun by hemodynamic stress. This diminution results from the aging of the heart per se and may be modulated by extracardiac factors. An age-related diminution was also observed in the mRNA induction of heat shock proteins by transient ischemia. However, this diminished induction of immediate early genes in the aged heart was not observed after more severe stress. With regard to the coronary vasculature, the age at which pressure-overload begins seems to be one of the important factors which determine the vascularity of hypertrophied hearts. Late-onset pressure-overload decreased dilator reserve in spite of the absence of myocardial hypertrophy. Thus, the responses to stress in the aged heart are quite different from those in the young heart. The limited capacity for adaptation to hemodynamic overload and poor protective mechanisms against stress may be causes of the higher incidence of heart failure in the aged.

Remodelling of microvessels by coronary hypertension or cardiac hypertrophy in rats

We attempted to clarify the individual effects of coronary hypertension and ventricular pressure-overload on the remodelling of coronary arterial microvessels. We examined structural vascular changes in the right ventricular free walls using two experimental rat models: 12-week ascending aortic banding, i.e. a model of coronary hypertension without ventricular pressure-overload and 12-week pulmonary artery banding, i.e. a model of ventricular pressure-overload without coronary hypertension. In vivo peak systolic left ventricular pressure and left ventricular weight to body weight ratio in the aortic banding model increased to 198 +/- 10 mmHg and by 39% above the controls, respectively. In vivo peak right ventricular pressure and right ventricular weight to body weight ratio in the pulmonary artery banding model increased to 87 +/- 7 mmHg and by 69% above the controls, respectively. The right coronary reserve measured by the Doppler method decreased in both experimental models. Aortic banding increased the medial area and perivascular collagen to lumen area ratios in the microvessels > 30 microns in lumen diameter but not in those < 30 microns. Pulmonary artery banding increased the perivascular collagen to lumen area ratio in the microvessels < 60 microns, but not in those > 60 microns. Medial thickening was not observed over the whole range of lumen diameter. These results suggest that the mechanisms responsible for the remodelling of coronary microvessels differ between non-hypertrophied hearts with coronary hypertension and hypertrophied hearts without coronary hypertension.

Preferential expression of HSC70 heat shock mRNA in gerbil heart after transient brain ischemia

Inductions of mRNAs for heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 were examined in the cerebral cortex, cerebellum, heart, lung, kidney, and liver of gerbils after a 10-min transient forebrain ischemia. HSP70 mRNA was normally expressed in a small amount in the cerebellum, lung, and kidney, but was not expressed in the heart or liver in a detectable amount. A very small amount of HSP70 mRNA was also present in the cerebral cortex. HSC70 mRNA was normally present in all the organs examined with a variety in the amount. Eight hours after the cerebral ischemia, the level of HSP70 mRNA increased in the cerebral cortex, lung, and kidney. HSC70 mRNA levels also increased in all the organs. However, the increase of HSC70 mRNA was remarkable in the heart. Transient cerebral ischemia caused subsequent hyperthermia. Treatment of gerbils with an artificial hyperthermia without cerebral ischemia increased the HSP70 and HSC70 mRNA levels as well. However, the HSC70 mRNA level in the heart after cerebral ischemia was much higher than that in the case with hyperthermic treatment. These results suggest that HSC70 mRNA was preferentially induced in the heart after transient forebrain ischemia that was not only due to the subsequent hyperthermia.

Sweet potato beta-amylase. Primary structure and identification of the active-site glutamyl residue

The complete amino acid sequence of a subunit of sweet potato beta-amylase, a homotetramer, was established by sequence analysis of peptides obtained by digestions with Achromobacter protease I and Staphylococcus aureus V8 protease and by cyanogen bromide cleavage of the S-carboxymethylated subunit. The subunit of the enzyme is a single polypeptide consisting of 498 amino acid residues. It showed 50-60% identity in the amino acid sequence with those of beta-amylases from soybean and barley, while it about 25% with those of three bacterial beta-amylases deduced from the cDNA sequences. Sweet potato beta-amylase was completely inactivated with 2,3-epoxypropyl alpha-D-[U-14C]glucopyranoside. Sequence analysis of the inactivated enzyme revealed that Glu187 was specifically esterified by the affinity labeling with the above reagent, proposing that Glu187 is a potent candidate involved directly in the catalysis with this plant beta-amylase.