Purification and characterization of angiotensin II degradation factor from porcine endothelial cells

We investigated the degradation of angiotensin II by vascular endothelial cells and smooth muscle cells in vitro. When angiotensin II was incubated with confluent culture of endothelial cells or with serum free conditioned medium of the endothelial cells, angiotensin II was destroyed rapidly. When angiotensin II was incubated with cultured vascular smooth muscle cells or their serum free conditioned medium, degradation was not observed. To identify the angiotensin II degradation factor (ADF), we have purified ADF from the conditioned medium of endothelial cells, by column chromatographies, i.e., hydroxyapatite, ion exchange and gel filtration chromatography. The partially purified ADF had apparent molecular masses of 154 kDa on gel filtration chromatography. Its pH optimum was about 7.0. ADF was inhibited by p-chloromercuribenzoic acid, iodoacetamide and high concentration of EDTA, but not by diisopropyl fluorophosphate, bestatin, amastatin or pepstatin A. Of the synthetic substrates examined, ADF degrades human angiotensin II, [Val5]-angiotensin II and [Asn1, Val5]-angiotensin II. It did not degrade angiotensin I.

A hotspot of spontaneous and UV-induced illegitimate recombination during formation of lambda bio transducing phage

To study the mechanism of spontaneous and UV-induced illegitimate recombination, we examined the formation of the lambda bio specialized transducing phage in Escherichia coli. Because most lambda bio transducing phages have double defects in the red and gam genes and have the capacity to form a plaque on an E. coli P2 lysogen (Spi- phenotype), we selected lambda bio transducing phage by their Spi- phenotype, rather than using the bio marker. We determined sequences of recombination junctions of lambda bio transducing phages isolated with or without UV irradiation and deduced sequences of parental recombination sites. The recombination sites were widely distributed on E. coli bio and lambda DNAs, except for a hotspot which accounts for 57% of UV-induced lambda bio transducing phages and 77% of spontaneously induced lambda bio transducing phages. The hotspot sites on E. coli and lambda DNAs shared a short homology of 9 bp. In addition, we detected direct repeat sequences of 8 bp within and near both the bio and lambda hotspots. A recA mutation did not affect the frequency of the recombination at the hotspot, indicating that this recombination is not a variant of recA-dependent homologous recombination. We discuss a model in which the short homology as well as the direct repeats play essential roles in illegitimate recombination at the hotspot.

[Cardiac sarcoidosis with myopathy and advanced A-V nodal block in a woman with a previous diagnosis of sarcoidosis]

In 1992, a 49-year-old woman was admitted to the hospital because of exertional dyspnea. Three years earlier sarcoidosis had been diagnosed, and the patient was found to have bilateral hilar lymphadenopathy. The eye, skin, and knee joint were also involved. During the second hospital stay, atrial flutter with advanced A-V nodal block, scattered defects on a 201T1 scintigram, and marked cardiomegaly on chest roentgenogram led to the diagnosis of cardiac sarcoidosis. Signs and symptoms of cardiac failure subsided after placement of an artificial cardiac pacemaker, but the patient still complained of mild muscle weakness in the lower extremities on exertion. 67Ga scintigraphy revealed marked accumulation in the lower extremities, and muscle biopsy of the left gastrocnemius revealed numerous epithelioid cell granulomas with muscle fiber degeneration. Oral corticosteroid therapy was effective. A review of the 24 cases of sarcoid myopathy reported in Japan indicated that the male-to-female ratio is 1:3.8. As compared to patients in whom myopathy led to the diagnosis of sarcoidosis, those in whom myopathy developed after sarcoidosis was diagnosed were (1) relatively older, (2) more likely to have multiple organ involvement, and (3) more likely to have cardiac sarcoidosis. Corticosteroids were beneficial in about three quarters of these 16 cases, who received corticosteroid therapy.

Protective effect of nitric oxide on development of acute pancreatitis in rats

Nitric oxide (NO) has been implicated to regulate pancreatic circulation, promote capillary integrity, and inhibit leukocyte adhesion. We investigated the role of NO in the development of pancreatitis. Nitro-L-arginine, an inhibitor of NO synthase, in total dose of 35 mg/kg body wt was infused in the rats with edematous pancreatitis induced by two intraperitoneal injections of cerulein (20 micrograms/kg). L-Arginine (125 or 250 mg/kg), a NO donor was intravenously administered twice in the rats with hemorrhagic pancreatitis induced by water-immersion stress plus two intraperitoneal injections of cerulein (40 micrograms/kg). The degree of pancreas edema, serum amylase levels, and histologic alterations were investigated. Nitro-L-arginine exacerbated cerulein-induced pancreatitis and caused a decrease in pancreatic blood flow. L-Arginine ameliorated the severity of hemorrhagic pancreatitis dose dependently and improved the pancreatic blood flow. These findings suggest that NO could confer protection against the development of hemorrhagic pancreatitis, probably through improvement of the pancreatic microcirculation.

Short-term topical therapy of experimental tinea pedis in guinea pigs with lanoconazole, a new imidazole antimycotic agent

The therapeutic efficacy of short-term treatment with a 1% cream of lanoconazole, a new imidazole antimycotic agent, in comparison with that of a 1% cream of terbinafine was evaluated in the guinea pig model of tinea pedis. Each agent was topically applied once a day for 3 or 7 consecutive days, starting on day 10 postinfection, and a culture study was conducted on day 5 after the last treatment with each agent. The 1% cream of lanoconazole was as highly effective as the 1% cream of terbinafine in terms of eradicating the fungi from the infected feet.

Amyloid beta peptide induces cytoplasmic accumulation of amyloid protein precursor via tau protein kinase I/glycogen synthase kinase-3 beta in rat hippocampal neurons

Exogenous application of synthetic amyloid beta protein (A beta) is known to induce neurotoxic effects in rat hippocampal culture. We report here that A beta (25-35) induces accumulation of amyloid precursor protein (APP) derivatives in the cytoplasm of neurons. At the same time, the level of the secreted form of APP released into the culture medium decreases. Tau protein kinase I/glycogen synthase kinase-3 beta (TPK I/GSK-3 beta) antisense oligonucleotide blocked APP accumulation and prevented neuronal death. These results provide evidence that APP accumulation after A beta treatment is regulated by TPK I/GSK-3 beta. A beta neurotoxicity is probably mediated via phosphorylation of tau by TPK I/GSK-3 beta, resulting in an impairment of axonal transport, and cytoplasmic accumulation of APP.

Two novel rat guanylin molecules, guanylin-94 and guanylin-16, do not increase cyclic GMP production in T84 cells

Guanylin, a 15-amino acid peptide homologue of bacterial heat-stable enterotoxins, is an endogenous activator of guanylate cyclase C (GC-C). We isolated two novel guanylin molecules from rat intestinal mucosa. They contained guanylin-15 at their C-termini and were identified as guanylin-94 and guanylin-16 by amino acid sequencing and mass spectrometry. Guanylin-94 and guanylin-16 in total account for 85% of guanylin molecules in both the small and large intestine, guanylin-15 being a minor component. Rat guanylin-94 and guanylin-16 did not increase cyclic GMP production in T84 cells. Identification of the post-translational processing products of guanylin should provide a better understanding of the biosynthesis of the peptide.

Maximum sustained fin-kick thrust in underwater swimming

We examined the upper limit of a diver's fin-kick thrust force using a stationary-swimming ergometer. Heart rate, respiratory minute volume, oxygen uptake, and performance rate were measured in four male subjects who swam constantly for 8 min to maintain a horizontal position against an applied force at a depth of 0.7 m. The water temperature was controlled at 26 degrees +/- 1 degree C. The performance rate, which was the parameter of how well the subjects compensated for the applied load, showed an upper limit around 64 N of sustainable thrust force. This meant that the diver could generate the swimming thrust force within 64 N continuously for 8 min in a steady state. Heart rate, respiratory minute volume, and O2 uptake showed almost proportional increases to the applied load within 64 N and tended to plateau about 69 N.

Structures of metal sites of oxidized bovine heart cytochrome c oxidase at 2.8 A

The high resolution three-dimensional x-ray structure of the metal sites of bovine heart cytochrome c oxidase is reported. Cytochrome c oxidase is the largest membrane protein yet crystallized and analyzed at atomic resolution. Electron density distribution of the oxidized bovine cytochrome c oxidase at 2.8 A resolution indicates a dinuclear copper center with an unexpected structure similar to a [2Fe-2S]-type iron-sulfur center. Previously predicted zinc and magnesium sites have been located, the former bound by a nuclear encoded subunit on the matrix side of the membrane, and the latter situated between heme a3 and CuA, at the interface of subunits I and II. The O2 binding site contains heme a3 iron and copper atoms (CuB) with an interatomic distance of 4.5 A; there is no detectable bridging ligand between iron and copper atoms in spite of a strong antiferromagnetic coupling between them. A hydrogen bond is present between a hydroxyl group of the hydroxyfarnesylethyl side chain of heme a3 and an OH of a tyrosine. The tyrosine phenol plane is immediately adjacent and perpendicular to an imidazole group bonded to CuB, suggesting a possible role in intramolecular electron transfer or conformational control, the latter of which could induce the redox-coupled proton pumping. A phenyl group located halfway between a pyrrole plane of the heme a3 and an imidazole plane liganded to the other heme (heme a) could also influence electron transfer or conformational control.

Potent inhibitors of acyl-CoA:cholesterol acyltransferase. Structure-activity relationships of novel N-(4-oxochroman-8-yl)amides

Novel N-(4-oxochroman-8-yl)amide derivatives 1 were synthesized and tested for their ability to inhibit rabbit small intestinal ACAT (acyl-CoA:cholesterol acyltransferase) in vitro and to lower serum total cholesterol in cholesterol-fed rats in vivo. Among the synthesized compounds, N-(7-alkoxy-4-oxochroman-8-yl)amide derivatives showed potent ACAT inhibitory activity both in vitro and in vivo. The structure-activity relationships of these N-(4-oxochroman-8-yl)amides and related compounds are discussed on the basis of these two assays. The carbonyl group at position 4 of the 4-chromanone was essential for potent ACAT inhibitory activity. N-(Chromon-8-yl) derivatives were less potent than N-(4-oxochroman-8-yl) derivatives. An alkoxy group at position 7 of the 4-chromanone moiety was important for potent ACAT inhibitory activity. In the N-(7-alkoxy-4-oxochroman-8-yl)amide derivatives, another necessary factor to elicit the potent ACAT inhibitory activity was lipophilicity of the molecules. The highly lipophilic acid amides N-(7-methoxy-4-oxochroman-8-yl)-2,2-dimethyldodecanamide (35) and 4-[[6-(4-chlorophenoxy)hexyl]oxy]-N-(7-methoxy-4-oxochroman-8- yl)benzamide (63) showed potent activity. Introduction of a highly lipophilic alkoxy group at position 7 of the 4-chromanone moiety instead of methoxy group also resulted in potent activity. In this case, highest inhibitory activity was obtained by N-[7-(decyloxy)-4-oxochroman-8-yl]-2,2-dimethylpropanamid e (65). The most potent compound, N-(7-methoxy-4-oxochroman-8-yl)-2,2-dimethyldodecanamide (35, TEI-6522), showed significant ACAT inhibitory activity (rabbit small intestine IC50 = 13 nM, rabbit liver IC50 = 16 nM), foam cell formation inhibitory activity (rat peritoneal macrophage IC50 = 160 nM), and extremely potent serum cholesterol-lowering activity in cholesterol-fed rats (61% at a dose of 0.1 mg/kg/day po).

Properties of Ca(2+)-dependent K+ channels of human gingival fibroblasts

Cells in the oral cavity are normally exposed to different temperatures. Ion transport systems are influenced by temperature in other tissues: In particular, changes in intracellular K+ ion can affect cell growth and synthesis of macromolecules. The purpose of this investigation was to identify K+ channels in human gingival fibroblast cells and analyze the effect of temperature on their K+ conduction properties. Ca(2+)-dependent K+ channels with a large conductance (125 pS in symmetrical K(+)-rich solutions) were identified in human gingival fibroblasts and studied by the patch-clamp technique. The open probability of the channels varied with membrane potential between +40 and -100 mV. When the bath temperature was decreased from 40 to 4 degrees C, channel conductance was reduced, but the mean open time of the channels was increased. The activation energies for the conductance and the reciprocal of the mean open time were estimated to be 9.1 and 22.9 kJ/mol, respectively. These values are lower than those reported for these and other types of channels in cells from other tissues. The open probability of the channels was nearly constant in the temperature range studied. These results suggest that the properties of Ca(2+)-dependent K+ channels of gingival fibroblasts remain relatively unchanged when the cells are exposed to a wide range of temperatures.

Inhibitory effect of sodium 5,6-benzylidene ascorbate (SBA) on the elevation of melanin biosynthesis induced by ultraviolet-A (UV-A) light in cultured B-16 melanoma cells

Sodium 5,6-benzylidene ascorbate (SBA) is a conjugate of ascorbic acid (Asc) with benzyaldehyde. It has been found that the antioxidant activity of SBA is more stable and has a longer lifetime in living cells and organs than Asc. In this study, we investigated the effect of SBA on the induction of melanin in cultured melanoma (B-16) cells irradiated by UV-A. Melanin content of B-16 cells was significantly increased by UV-A irradiation. The induction was abolished by mannitol and particularly by superoxide dismutase, suggesting the involvement of O2- in the biosynthesis of melanin in cultured melanoma cells. This was theorized by the fact that the induction was also observed in B-16 cells treated with superoxide anion radicals chemically generated in the hypoxanthine/xanthine oxidase-reaction system, instead of UV-A irradiation. The induction of melanin caused by UV-A irradiation was suppressed by SBA in a dose-dependent manner. To elucidate the mechanism of this suppressive effect, the scavenging activity against O2-, and the inhibitory effect of SBA on tyrosinase activity were examined. ESR spectrometric analysis showed that SBA strongly scavenged O2-, and the presence of SBA in the medium remarkably inhibited the tyrosinase activity in cultured B-16 melanoma cells. It can be concluded that SBA effectively inhibits the melanin biosynthesis in B-16 melanoma cells induced by reactive oxygen species (ROS) generated by UV-A irradiation via tyrosinase.

Dirofilaria immitis: immunohistochemical localization of acid proteinase in the adult worm

The distribution of Dirofilaria immitis acid proteinase in adult worm tissue was examined biochemically and immunohistochemically. About 45% of the total proteinase activity of 700g supernatant, which was obtained from the 0.25 M sucrose homogenate of live adult worms, was found in the 100,000g supernatant by subcellular centrifugation analysis. The distribution pattern of the proteinase activity observed by Percoll density gradient centrifugation coincided with that of glucose-6-phosphatase, a marker cytosolic enzyme, suggesting that the acid proteinase was present in vivo in a membrane-free form, possibly in the cytosol or secretory fluid. Immunostaining for the proteinase in the parasite tissue using the IgG1 (kappa-type) monoclonal antibody, H-1, revealed immunoreactive enzyme primarily inside the cell as small grains, but not on the cell surface, and immunoreactivity was distributed widely in worm tissues such as lateral cords, dorsal and ventral median cords, the anterior end of the parasite, and intestinal epithelial cells in granular form. In the male reproductive system, the testicular wall and germ cells were labeled with the antibody, and in the female, uterine walls, fertilized eggs, and developing eggs as well as microfilaria were labeled. In conclusion, D. immitis acid proteinase is widely distributed in the parasite tissue, possibly functioning not only in nutrition metabolism but also in production of sperm and microfilariae, etc.

Adherence of Helicobacter pylori to cultured human gastric carcinoma cells

AIM

To examine the binding activity of Helicobacter pylori to cultured gastric epithelial cells using flow cytometry.

MATERIALS AND METHODS

We evaluated the adherence of 15 H. pylori strains to cultured gastric cancer (MKN45) cells by flow cytometric analysis. Other bacterial strains were also analysed for their adherence to MKN45 cells. In addition, we examined the effect of fetuin on the adherence of H. pylori to MKN45 cells.

RESULTS

H. pylori strains adhered to MKN45 cells at rates of between 49 and 93.7%, with a mean of 75.3%. In contrast, the rates of Escherichia coli, Shigella flexneri, Vibrio cholerae and Yersinia enterocolitica adherence to MKN45 cells were 69.1, 5.9, 11.7 and 33.1%, respectively. Fetuin had no inhibitory effect on the adherence of H. pylori to MKN45 cells in the flow cytometric analysis.

CONCLUSIONS

A flow cytometric analysis using MKN45 cells proved to be an objective and sensitive method for evaluating the adherence of H. pylori, showing close adherence between this organism and gastric epithelial cells.

Cerebral beta amyloid deposition in patients with malignant neoplasms: its prevalence with aging and effects of radiation therapy on vascular amyloid

We examined immunohistochemically 123 autopsy brains from patients aged between 30 to 59, who died as a result of malignant neoplasms. Using antiserum to amyloid beta protein (A beta), we found that cerebral A beta deposits began in the subjects' fifth decade; its prevalence was 0%, 9.8% and 21.5% in the fourth, fifth and sixth decades, respectively. The major form of A beta deposition was diffuse-type plaques, although one third of the brains with A beta deposition showed amyloid angiopathy. Subpial A beta deposition is frequently associated with amyloid angiopathy. The prevalence of cerebral A beta deposits was about two times higher in the patients who had received brain radiation therapy (27.8%) compared to non-radiated patients (14.8%). Amyloid angiopathy was much more prominent (P < 0.05) with radiation therapy (22.2%) than without (8.0%). We found that cerebral A beta-deposition is dependent on aging, even in patients with malignant tumors and at beginning in their forties, and that brain radiation therapy is a possible risk factor of A beta deposition, especially in the form of amyloid angiopathy.

Vocal cord paralysis in patients with thoracic esophageal carcinoma

Of 478 consecutive patients with intrathoracic esophageal carcinoma, 5% had vocal cord paralysis. In two thirds of the patients with vocal cord paralysis, the paralysis was caused by a metastatic lymph node located along the recurrent laryngeal nerve. These findings indicate that the possibility exists for radical surgery by esophagectomy and resection of the metastatic lymph node infiltrating the recurrent laryngeal nerve, even in patients with vocal cord paralysis. However, in only two patients was radical surgery accomplished. None of the 24 patients with paralysis survived without disease for more than 1 year. Thus, in patients with vocal cord paralysis, the need for combined therapy should be emphasized.

Genotyping of ABO blood groups by PCR and RFLP analysis of 5 nucleotide positions

The genotyping of ABO blood groups was performed using the polymerase chain reaction (PCR) method. The 4 DNA fragments containing the nucleotide position 261, 526, 703 and 796 of cDNA from A-transferase were amplified by PCR, and the amplified DNA subjected to restriction fragment length polymorphism (RFLP) analysis. The different nucleotide at position 803 was clearly distinguished by electrophoresis of the PCR products amplified with allele-specific primers. By analyzing the electrophoresis patterns, ABO genotyping was conclusively accomplished. The frequencies of ABO genotypes found in Japanese blood donors with A and B phenotypes were as follows: in the phenotype A group, AA = 19.8% and AO = 80.2%; and in the phenotype B group, BB = 12.8% and BO = 87.2%.

Molecular analysis of lambda bio transducing phage produced by oxolinic acid-induced illegitimate recombination in vivo

To study the mechanism of DNA gyrase-mediated illegitimate recombination in Escherichia coli, we examined the formation of lambda Spi- phage during prophage induction. The frequency of Spi- phage was two to three orders of magnitude higher in the presence of oxolinic acid, an inhibitor of DNA gyrase A subunit, than in the absence of the drug, while it was very low in nalAr bacteria with the drug. RecA function is not required for the formation of these phages, indicating that this enhancement is not caused by the expression of SOS-controlled genes. Analyses of att region and recombination junctions of Spi- phages revealed that they have essentially the same structures as lambda bio transducing phages but are classified into two groups with respect to recombination sites. In the majority class of the transducing phages, there were not more than 3-bp homologies between the parental E. coli bio and lambda recombination sites. In the minority class of the transducing phages, on the other hand, 9-10-bp homologies were found between the parental recombination sites. These results suggested that oxolinic acid-induced illegitimate recombination takes place by two variants of a DNA gyrase-dependent mechanism.

Suppression of anti-Candida activity of murine neutrophils by progesterone in vitro: a possible mechanism in pregnant women's vulnerability to vaginal candidiasis

Sex steroid hormones were examined for their effect on mycelial growth of Candida albicans, and the inhibitory activity of casein-induced murine peritoneal neutrophils against mycelial growth of C. albicans was examined in vitro using a crystal violet staining method or a [3H]glucose incorporation method. Four steroid hormones, danazol, estradiol, estriol and testosterone had no effect on mycelial growth of C. albicans, but progesterone appeared to convert the growth form of C. albicans from hyphal to yeast. Danazol (10(-6) M) and progesterone (10(-5) M) suppressed anti-Candida activity of neutrophils of non-treated mice, while testosterone, estradiol, and estriol did not. The anti-Candida activity of neutrophils of estradiol-pretreated mice was clearly suppressed by progesterone even at 10(-6) M which corresponded to its plasma concentration in pregnant women in the third trimester. The physiological significance of this suppressive effect of progesterone was discussed in relation to the vulnerability of pregnant women to vaginal candidiasis.

Vasopressin V1-receptor stimulation produces a positive inotropic response without affecting pHi in guinea pig papillary muscles

Effects of arginine-vasopressin (AVP) on the contractile force, action potential (AP) and intracellular pH (pHi) were studied in isolated guinea pig papillary muscles using conventional and ion-selective microelectrode techniques. AVP increased the developed tension and the resting tension, and these responses were attenuated by the V1-receptor antagonist OPC-21268 (1-(1-[4-(3-acetylaminopropoxy)benzoyl]-4-piperidyl)-3,4-dihydro-2 (1H)- quinolinone). However, AVP failed to affect AP configuration or pHi. These results suggest that AVP produces a positive inotropy by mechanism(s) other than intracellular alkalinization.

[Reconstitution of human immune systems in severe combined immunodeficient mouse--with reference to the reconstituted with human splenic cells and tissues from patients with gastric cancer]

Normal peripheral blood lymphocyte (PBL) from healthy donors, and splenic cells and tissues from patients with gastric cancers were implanted into the severe combined immunodeficient (SCID) mouse. The normal PBLs at 10(7) and 10(8)/mouse were implanted intraperitoneally (ip), and three to six splenic tissues with a size of 3 x 3 x 3 mm from gastric cancer patients were inoculated subcutaneously (sc) into the bilateral backs of the mice. The dissociated splenic cells were also administered ip and intravenously (iv). At 2, 4, 6 and 8 weeks after inoculation, mice were killed, and the human IgG and IgM were assessed by ELISA method. SCID mice with splenic cells and tissue revealed high human IgG and IgM levels from 2 weeks after inoculation, while the IgG levels in mice treated with PBLs were limited. When the tetanus toxoid was challenged to SCID mice reconstituted with splenic tissue, the anti-tetanus IgG was observed in 10 of 43 mice, showing the human B cell functions in the mice. Although the reconstitution of T cell surface marker in SCID mice was incomplete, OKT3, OKT4 and OKT8 surface markers were successfully observed in 10% to 20% SCID mice of which splenic cells were incubated with IL-2 or anti-CD3 monoclonal antibody. This model was thought to be adequate for evaluating human immunological functions of the patients with gastric cancer in vivo.

[Forensic DNA typing using AmpliType PM (Amp-PM) kit--allele frequency distributions of the five marker loci in Japanese population, and evaluation of Amp-PM markers for typing of saliva stain and hair]

Population study was carried out on the Japanese from Toyama district using the AmpliType PM PCR amplification and typing kit (Perkin Elmer) system, and then application of the kit system to forensic materials was evaluated. Using the kit system, 2 alleles could be identified for every locus of low density lipoprotein receptor (LDLR), glycophorin A (GYPA), hemoglobin G gammaglobin (HBGG), D7S8, and 3 alleles for group specific component (GC) in a sample size of 100 unrelated individuals. Allele frequency distributions of the sample were 0.18 for A, 0.82 for B in LDLR; 0.61 for A, 0.39 for B in GYPA; 0.27 for A, 0.73 for B, 0 for C in HBGG; 0.61 for A, 0.39 for B in D7S8 and 0.31 for A, 0.48 for B, 0.21 for C in GC. Deviations from Hardy-Weinberg equilibrium could not be observed in LDLR, GYPA, D7S8 and GC loci, except in HBGG locus (p < 0.05). All genotypes of the 5 loci could be detected from every saliva stains from 12 donors, but the genotypes estimated from 3 saliva samples unexpectedly did not correspond to those on the blood from same donors. Identification of the genotype from a hair root in telophase was available only in 3 individual samples out of 12 donors. The present experiment show that further improvement should be made on the application of the kit system to saliva stain.

Clinical and electrophysiological characteristics of atrial standstill

To clarify the clinical and electrophysiological characteristics of atrial standstill (AS) we studied 11 patients (7 males and 4 females), whose average age was 62 years and who were followed over a period of 4-179 months. Underlying heart disease was present in nine patients and two cases were idiopathic. Major clinical symptoms in the 11 cases included Adams-Stokes attacks, and dyspnea on exertion. In the standard 12-lead ECGs obtained on admission, the P wave was absent in six cases. Atrial flutter (AF) was noted in 3, atrial fibrillation (Af) in 1, and multifocal atrial tachycardia in 1. In some cases, the ECG initially showed AF or Af, and was transformed after several years into ectopic atrial tachycardia or an ectopic atrial rhythm with a markedly decreased amplitude of the P wave. Finally, the P wave disappeared over a prolonged period. When intracardiac mapping was performed, the atrial electrograms tended to diminish at the site of high, mid-lateral right atrium (RA). Electrograms were remained present in the vicinity of the tricuspid valve (TV) annulus. A repeated mapping and pacing study conducted in two patients revealed that the "silent" area spread toward the lower site of RA. During the average follow-up period of 64 months, four patients died. The interval until death in one patient with myocarditis was 6 months, and in another with dilated cardiomyopathy (DCM) it was 8 months. It appears that the atrial muscular lesion starts in the high lateral RA and progresses toward the lower RA, then to the vicinity of the TV annulus. A diffuse and progressive disturbance may occur not only in the atrial muscle, but also in the atrioventricular conduction system in patients with AS who had progressive myocarditis or DCM.

Mortality of Candida albicans-infected mice is facilitated by superinfection of Escherichia coli or administration of its lipopolysaccharide

Pathogenesis of complex infection with Candida albicans and gram-negative bacteria was studied by determining the influence of infection with Escherichia coli or injection of E. coli lipopolysaccharide (LPS) on mortality of C. albicans-infected mice. Mice were infected intravenously with lethal doses of C. albicans, then treated intravenously at various times with viable E. coli or E. coli LPS, which individually were not lethal. Treatments 3 h after C. albicans infection clearly facilitated the death of the mice. Corresponding to this facilitated death, production of tumor necrosis factor (TNF) in sera was augmented 2 h after LPS injection into the infected mice. Similar increased production of TNF was also observed in mice treated with a nonlethal combination of heat-killed C. albicans and LPS. The number of viable C. albicans in kidneys of the infected mice was increased by LPS treatment, which was assumed to be the main cause of the greater mortality rate.