Plasma (1-->3)-beta-D-glucan measurement in diagnosis of invasive deep mycosis and fungal febrile episodes

(1-->3)-beta-D-glucan is a characteristic fungal cell-wall constituent. To assess the clinical usefulness of this glucan in screening for invasive fungal infection or fungal febrile episodes, we measured the plasma concentration at the time of routine blood culture in 202 febrile episodes by means of factor G, a horseshoe-crab coagulation enzyme that is extremely sensitive to this polysaccharide. With a plasma cut-off value of 20 pg/mL, 37 of 41 episodes of definite fungal infections (confirmed at necropsy or by microbiology) had positive results (sensitivity 90%). All of 59 episodes of non-fungal infections, tumour fever, or collagen diseases had concentrations below the cut-off value (specificity 100%). Of 102 episodes of fever of unknown origin, 26 had plasma glucan concentrations of more than 20 pg/mL. With those 102 cases taken as non-fungal infections, the positive predictive value of the test was estimated as 59% (37/63), the negative predictive value as 97% (135/139), and the efficiency as 85% (172/202). The positive predictive value should improve if there were a sensitive gold standard that could discriminate fungal from non-fungal infections. Causative fungi included candida, aspergillus, cryptococcus, and trichosporon. Determination of plasma (1-->3)-beta-D-glucan with factor G is a highly sensitive and specific test for invasive deep mycosis and fungal febrile episodes, and will substantially benefit immunocompromised patients.

Em18, a new serodiagnostic marker for differentiation of active and inactive cases of alveolar hydatid disease

We determined whether detection of antibody response against a newly detected epitope, designated Em18, among Echinococcus multilocularis antigens could be a reliable marker for differentiation of active cases of alveolar hydatid disease (AHD) from inactive cases. Fifteen Alaskan patients with either active or inactive lesions of AHD previously confirmed clinically, pathologically, and serologically by the Em2-enzyme-linked immunosorbent assay (ELISA) were used for a blind test by Western blotting. Ten and five cases were considered to be active and inactive cases, respectively. One of the 10 cases classified serologically as active was judged to be inactive based on clinical and pathologic criteria; the patient had a recognizable parasitic lesion, and following short-term treatment with albendazole, a biopsy of the liver showed a degenerated lesion that did not grow in rodents. The five cases judged to be inactive included two confirmed inactive cases with cicatrized lesions and three active cases that showed the weakest values in the Em2-ELISA. The most predominant IgG subclass responding to Em18 was IgG4. In general, there were good correlations between 1) the antibody response against Em18 and the presence of active lesions and 2) the antibody response against Em18 and the Em2-ELISA values.

Effect of hemorrhagic hypotension on blood flow to the basal and upper turns of the cochlea

The effect of hemorrhagic hypotension on blood flow in the cochlea was studied in guinea pigs. Using two laser Doppler probes, simultaneous measurements were made from the basal and upper turns of the cochlea. Hypotension induced by removal of blood resulted in reduction of cochlear blood flow. Cochlear blood flow, however, did not reduce the same extent as the extent of hypotension and the reduction of blood flow was observed to be more remarkable in the upper turns than in the basal turn.

Expression of bone matrix protein messenger ribonucleic acids in human breast cancers. Possible involvement of osteopontin in development of calcifying foci

BACKGROUND

Development of calcifying foci is a fairly common finding in human breast cancers, and the deposition of calcium phosphate is observed in such foci. The calcium phosphate is a physiologic component of bones and teeth. Since the expression of messenger (m) RNAs of osteopontin (OPN), osteocalcin (OC), osteonectin (ON), and matrix gla protein (MGP) has been described in bones and teeth, we examined the mRNA expression of OPN, OC, ON, or MGP in the calcifying foci that were observed in human breast cancers.

EXPERIMENTAL DESIGN

Cell types expressing mRNAs of OPN, ON or MGP were identified with combination of in situ hybridization and immunohistochemistry.

RESULTS

The OPN mRNA-expressing cells clustered around the necrotic foci within cancer cell nests, and the examination with anti-OPN antibody revealed that OPN protein was localized in such necrotic foci where calcium phosphate deposited. The OPN mRNA-expressing cells were identified as macrophages by staining the adjacent section with the anti-CD68 PG-M1 monoclonal antibody which specifically recognizes macrophages. Neither ON mRNA-expressing cells nor MGP mRNA-expressing cells appeared to correlate with the deposition of calcium phosphate.

CONCLUSIONS

The OPN protein produced by macrophages appeared to play a significant role for development of calcifying foci within necrotic area of breast cancers.

A case of allergic aspergillus sinusitis with acute onset

Reports of allergic aspergillus sinusitis have increased in recent years and diagnostic criteria have also come to be established, yet this disease remains a rare disorder. The disorder is generally reported to follow a chronic course. Here we report a case of allergic aspergillus sinusitis with a short morbid term of 3 weeks.

[Immunoregulatory role of gamma delta T cell receptor in atopic asthma--association with the IgE response to molds antigen]

To evaluate the role of gamma delta T cells in atopic asthma, we examined the relationship among atopy bronchial asthma, and genetic polymorphism of the gamma chain of T cell receptors (TCR) in families through atopic asthmatic probands. We recruited 5 families (69 subjects). Total serum IgE levels were estimated by a radioimmunosorbent test (IgE RIST). Skin prick tests were done with inhaled allergens consisting of house dust, grass and tree pollens, common molds, and animal danders. Antigen-specific IgE levels in response to these allergens were also measured by multiple antigen simultaneous test (IgE MAST). The atopic phenotype was determined by the presence of a positive skin test, an elevated antigen specific IgE value, an elevated total IgE level, or some combination of these. Although linkage of atopy or bronchial asthma to the gene encoding the gamma chain of TCR was excluded, the lod score between this gene and molds-specific IgE responses was 0.42 at the recombination fraction of 0.1. In an association study, a 19 kb allele of the gamma chain of the TCR gene was found more frequently in asthmatic subjects than in non-asthmatic subjects (p = 0.068). Also, molds-specific IgE responses were significantly associated with this allele (p = 0.018). These findings suggest that molds-specific IgE responses underlying atopic asthma are partly regulated by the gene encoding the gamma chain of the TCR.

Monte Carlo simulation of DNA strand breaks induced by monoenergetic electrons using higher-order structure models of DNA

A new theoretical model for estimating yield of initial DNA strand break induced by several monoenergetic electrons is presented. It is based on the Monte Carlo track structure simulation and on new DNA structure models (one turn of double-strand DNA, nucleosome, solenoid), and links physical and chemical stages of radiation action. Direct and indirect effects are strictly distinguished. Some results of calculations indicated: (1) the number of single strand breaks per nucleus (6 microns in diameter) per Gy in pure water was about 10 times that in a cell environment (OH radical life time is assumed to be 8.7 ns). This is due to the difference in the time-dependent variation in the total number of the OH radical; and (2) the contribution of indirect effects to total damage decreased as the order of the DNA target model structure used in the stimulation increased (e.g. a one-turn model of double-strand DNA, approximately 98.4%; but the 30-nm solenoid model, approximately 86.1%). This was due to the protective effect of histone protein against OH radical attack. Double-strand breaks were scored if two single-strand breaks were located on the same base pair. The present study indicated that the information from morphological and biochemical examinations of the cell environment must be considered more carefully with computer simulation.

Stimulation of the biosynthesis of interleukin 8 by interleukin 1 and tumor necrosis factor alpha in cultured human chorionic cells

Human chorion, but not amnion, tissue explants produced substantial quantities of neutrophil chemoattractant in response to interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF alpha). This suggested that chorion is one of the chemoattractant producing tissues. Therefore, the biochemical properties and the regulation of a chemoattractant in human chorionic cells were examined. IL-1 alpha and TNF alpha stimulated human chorionic cells to produce neutrophil chemotactic factor in both a dose- and time-dependent manner. This chemotactic factor was a heat-stable and trypsin-sensitive protein with an apparent molecular weight of 10000, and it was also immunologically identified as a chemotactic cytokine of the human IL-8 family. Immunohistochemical observations with IL-1 alpha- and TNF alpha-treated chorion explants indicated that trophoblasts and stromal cells, including fibroblast-like and macrophage-like cells, but not endothelial cells, were characterized as IL-8-producing cells. From these observations, it is very likely that both IL-1 and TNF alpha may participate in the production of chemotactic factor/IL-8 in pre-term parturition, accompanied by an intraamniotic infection, along with their known promotive effect on the production of matrix metalloproteinases, which is connected with the destruction of matrix components of fetal membranes.

Expression of the c-met protooncogene in human hepatocellular carcinoma

The c-met protooncogene is a growth factor receptor with tyrosine kinase activity. Recently the hepatocyte growth factor was identified as the ligand for this receptor. Because the hepatocyte growth factor is a most potent mitogen in hepatocytes, possible involvement of c-met expression in hepatocarcinogenesis is suspected. In this study, we examined c-met expression in 23 hepatocellular carcinoma cases by means of Northern-blot analysis and an immunohistochemical study. Northern-blot analysis revealed c-met mRNA expression in the tumors of 6 of 19 patients (31.6%); in the immunohistochemical study, c-met protein was detected in 16 of 23 patients (69.6%). With both methods, c-met was found to be overexpressed in hepatocellular carcinoma compared with the surrounding normal liver. Comprehensive analysis showed that c-met protein expression was correlated with poor-to-moderate differentiation of cancer cells (p < 0.05). Tumor proliferative activity of hepatocellular carcinoma was evaluated by means of Ki-67 labeling index. All cases with increased tumor proliferative activity showed c-met protein expression, although the elevation of proliferative activity in the c-met-positive group was not statistically significant. These data suggest that the overexpression of c-met plays an important role in the development of hepatocellular carcinoma.

[Assessment of the volume of the mastoid air cell system using digital image processing]

There has been a great deal of controversy concerning the development of pneumatization in the temporal bone. Many reports on the size of the mastoid air cell system have been discussed a planimetric X-ray method, however, there have been no techniques for direct volume measurement based on high-resolution computed tomography (CT). Discussion of the relationship between ear disease and pneumatization of the temporal bone requires three-dimensional measurement of the temporal bone in vivo. Recently, we developed such a technique by using digital image processing to measure the volume of the mastoid air cell system. With this technique, only the air cells and tympanic cavity, with a grey scale level similar to air outside the skull were easily selected on the CT films. Then, after image processing called "thresholding", only the areas and volumes of these extracted pneumatized parts were calculated. The volumes of the pneumatized parts of the temporal bone were calculated separately as partial volumes divided by several CT planes. The sum of the partial volumes was calculated as the total volume of the aerated cavity. This technique also made it possible to reconstruct a three-dimensional (3D) model of the air cell system for visual presentation. CT images of 43 normal temporal bones were analyzed. The average volume temporal bone pneumatization (including air cells and tympanic cavity) was about 6ml. There were no differences between pneumatization on the two sides in either sex. Comparisons of partial volumes of pneumatization in the temporal bone revealed that the volumes of portions including the tympanic cavity and its surrounding air cells and those of the antrum and its surrounding air cells were larger than those of other portions. 3D models of the air cell system revealed a variety of shapes. These findings indicated that this technique is not only useful for quantitative analyses but for easy subjective morphological analyses.

Design of a new cationic amphiphile with efficient DNA-transfection ability

Several double-chain ammonium amphiphiles were designed to have physicochemical properties, such as membrane fluidity and aggregate morphology, suitable for DNA transfection, according to our previous results (1, 2). Potency of the amphiphiles during the transfer of plasmid DNA into COS cells was examined. Of the amphiphiles tested, O,O'-ditetradecanolyl-N-(trimethylammonio acetyl)diethanolamine chloride (14Dea2) had the highest transfection activity. Optimal conditions for transfection of COS cells by 14Dea2 were also determined.

Role of protein kinase C-mediated pathway in the pathogenesis of coronary artery spasm in a swine model

BACKGROUND

The intracellular mechanism of coronary artery spasm is still unknown. The pathway mediated by protein kinase C (PKC) is an important intracellular process of various cellular responses, including vascular smooth muscle contraction. Thus, we examined the role of the PKC-mediated pathway in the pathogenesis of coronary artery spasm in our in vivo swine model.

METHODS AND RESULTS

Seven Göttingen miniature pigs underwent coronary balloon injury and x-ray irradiation to induce atherosclerotic lesion. After 6 to 18 months, intracoronary serotonin (3 micrograms/kg) or histamine (3 micrograms/kg) repeatedly induced coronary artery spasm at the atherosclerotic site. At the spastic site, intracoronary administration of phorbol-12,13-dibutyrate (PDBu) (10(-9) mol/kg), a PKC-activating phorbol ester, also induced coronary artery spasm, which was completely blocked by pretreatment with intracoronary staurosporine (10 micrograms/kg), a PKC inhibitor. Intracoronary administration of an inactive phorbol ester, phorbol-12,13-didecanoate (10(-9) mol/kg), did not induce coronary vasoconstriction. Coronary artery spasm induced by the autacoids was significantly augmented by pretreatment with intracoronary PDBu and partially inhibited by staurosporine. Intracoronary administration of Bay K 8644 (10 micrograms/kg), a dihydropyridine-sensitive L-type calcium channel agonist, also induced coronary artery spasm at the spastic site, which was significantly inhibited by pretreatment with intracoronary staurosporine or nifedipine (0.1 mg/kg).

CONCLUSIONS

These results suggest (1) the PKC-mediated pathway is importantly involved in the pathogenesis of coronary artery spasm, (2) activation of the PKC-mediated pathway partially accounts for serotonin- and histamine-induced coronary artery spasm, and (3) at the spastic site, calcium influx through dihydropyridine-sensitive L-type calcium channel and/or calcium sensitivity of the contractile proteins may be augmented by the PKC-mediated pathway.

Arginine residues in the extension peptide are required for cleavage of a precursor by mitochondrial processing peptidase. Demonstration using synthetic peptide as a substrate

Mitochondrial processing peptidase (MPP) specifically recognizes a large variety of mitochondrial precursor proteins and correctly cleaves off the extension peptides. To determine the structure common to all the extension peptides that is required for specific recognition by MPP, we synthesized various oligopeptides of different chain lengths and amino acid sequences, based on the amino acid sequence of the extension peptide of pre-malate dehydrogenase, and determined kinetic parameters of the cleavage reactions. The minimal length of peptides for effective cleavage was 16 amino acid residues consisting of 11 and 5 residues from the cleavage site to the amino- and carboxyl-terminal sides, respectively. Two sets of basic amino acids in the peptide, the distal arginine residue at position -10 and the proximal ones at positions -3 and -2 relative to the cleavage site, were necessary for effective hydrolysis. Of these two, the residue at position -2 was more important for effective cleavage than the one at position -3 and could not be replaced by a lysine residue. The replacement of the distal arginine by lysine had no effect on the cleavage. Our study demonstrates that use of peptides with the proper length is essential for performing kinetic analyses on the cleavage reaction by MPP and that an arginine residue at position -2 to the cleavage site is necessary for the recognition and cleavage of the extension peptide.

Structural requirement for recognition of the precursor proteins by the mitochondrial processing peptidase

We examined the structural characteristics of the extension peptides responsible for the recognition by the mitochondrial processing peptidase by using preadrenodoxin, which has a long extension peptide of 58 amino acid residues, as the substrate. The deletion of various parts of the extension peptide of pre-adrenodoxin indicated that more than 40 amino acid residues and the presence of basic amino acid residues in the distal portion (20-40 amino acid residues upstream of the cleavage site) were necessary for the recognition of the precursor by the peptidase. The processing of preadrenodoxin was strongly inhibited by the synthetic peptide corresponding to the middle portion of the extension peptide, whereas the peptide corresponding to the amino-terminal portion exhibited weak inhibition of the processing. The replacement of arginine residues in the middle portion of the extension peptide with neutral amino acids resulted in a great decrease in the processing. We conclude that basic amino acids at a position distal to the cleavage site are necessary for the recognition of the precursor proteins by the processing peptidase and that basic amino acids required for the mitochondrial targeting and those for the recognition by the peptidase are separately located in the extension peptide of pre-adrenodoxin.

Direct imaging in a water layer of human chromosome fibres composed of nucleosomes and their higher-order structures by laser-plasma X-ray contact microscopy

X-ray contact microscopy with a 300-ps-duration laser-plasma X-ray source has been used to image hydrated human chromosomes. Clearly imaged are individual nucleosomes and their higher-order particles (superbeads), elementary chromatin fibrils. c. 30 nm in diameter and their higher-order fibres of various sizes up to c. 120 nm in diameter. The results demonstrate that X-ray microscopy is now capable of opening a new path of investigation into the detailed structures of hydrated chromosome fibres in their natural state.

Lack of any positive effect of intestinal metaplasia on induction of gastric tumors in Wistar rats treated with N-methyl-N-nitrosourea in their drinking water

The influence of intestinal metaplasia on gastric cancer induction was examined in five-week-old male Wistar:Crj rats. The animals were first treated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy) and then, starting two months after the irradiation, received 100 ppm N-methyl-N-nitrosourea (MNU) in their drinking water for 15 weeks. Thereafter they were maintained for 37 weeks with or without a dietary 1% sodium chloride (NaCl) supplement. The incidences of gastric adenocarcinomas in the MNU or MNU plus NaCl groups were significantly higher than in animals receiving X-rays plus MNU with or without NaCl. Intestinal metaplasias and the numbers of alkaline phosphatase (ALP)-positive foci were significantly increased in the X-ray irradiation groups but the numbers of ALP-positive foci were not increased with or without 1% NaCl. An inverse relationship between incidences of gastric tumors and intestinal metaplasias was apparent. The present experiment thus showed that the presence of intestinal metaplasia does not exert a positive influence on induction of gastric neoplasia by MNU in the rat.

Antibody responses in the wild vole, Clethrionomys rufocanus bedfordiae, naturally infected with Echinococcus multilocularis by western blotting

Antibody responses against crude antigens and the two (Em18 and Em16) epitopes of Echinococcus multilocularis were analysed by Western blotting using sera from the wild vole, Clethrionomys rufocanus bedfordiae (Crb), which were captured in Hokkaido, Japan and found to have been naturally infected with eggs, and compared with those in patients of AHD and mice experimentally infected with protoscoleces of this parasite. Antibody responses in the wild were demonstrated most clearly with anti-Crb-IgG antiserum but more faintly with anti-rat-IgG antiserum and poorly with anti-mouse-IgG or anti-human-IgG antisera or Protein G. Although only two serum samples of the wild vole found naturally infected were analysed, antibody responses against Em18 and Em16 in these voles appeared to be similar to those in AHD patients but differed from those in mice.

In vitro hatching of oncospheres of Taenia taeniaeformis using eggs isolated from fresh, frozen, formalin-fixed and ethanol-fixed segments

In order to establish a simple means of handling eggs of taeniid cestodes under non-biohazardous conditions, gravid segments of Taenia taeniaeformis were fixed in ethanol or formalin or were frozen. In vitro hatching of oncospheres was carried out by the 0.5% sodium hypochlorite method using eggs isolated from the nonviable and viable segments. No oncospheres hatched from formalized eggs, whereas almost all oncospheres hatched from all other eggs but the number of oncospheres recovered was highly variable. Oncospheres hatched from eggs isolated from frozen segments were highly fragile. The highest figures for in vitro hatching of oncospheres were recorded when eggs isolated either from segments fixed in 70% ethanol or from viable segments were used.

Protective antibodies against Taenia taeniaeformis in rats infected with eggs or injected with non-viable oncospheres or recombinant antigens of oncospheres

Antibody responses against Taenia taeniaeformis in rats infected with eggs or injected with non-viable oncospheres or recombinant antigens of oncospheres were analysed by passive transfer of serum and Western blotting. When recipient rats were injected with 1 ml serum from donors infected with eggs (infected serum), they all showed complete resistance to oral egg challenge, whereas those injected with 1 ml serum from donors injected with either oncospheres or recombinant antigens (vaccinated serum) showed no resistance. IgG and IgG subclass responses detected by Western blotting revealed that antibody responses to oncosphere antigens in infected serum thoroughly differed from those in vaccinated serum. It is suggested that IgG2 alpha responses in infected serum should be used for screening of epitopes for candidate vaccine.