Fungal metabolites. XVI. Structures of new peptaibols, trichokindins I-VII, from the fungus Trichoderma harzianum

New peptaibols, trichokindins I-VII, have been isolated from the fungus Trichoderma harzianum. Their structures were characterized by spectrometric methods. Trichokindins, which are 18-residue peptides containing one to three isovaline residues, were found to induce Ca(2+)-dependent catecholamine secretion from bovine adrenal medullary chromaffin cells.

Homologous cysteine proteinase genes located on two different chromosomes from Trypanosoma rangeli

DNA fragments were obtained by the polymerase chain reaction (PCR) using genomic DNA from T. rangeli as template and oligonucleotide primers encoding the active site amino acids of cysteine proteinase. After amplification by PCR, several DNA products were observed. These were purified and used as templates for a second round of PCR. This resulted in two DNA products of 475 and 498 bp. The 498 bp DNA (Tr-CP) contained both the sense and antisense primer sequences, and encoded a polypeptide having substantial homology with eukaryotic cysteine proteinases. The other product (Tr-DMR), which lacked the antisense primer sequence, encoded a polypeptide having homology with the DNA mismatch repair gene from Saccharomyces cerevisiae. The overall homology of the Tr-CP-encoded polypeptide to the cysteine proteinases from other trypanosome species was 69% identity (T. cruzi) and 73% identity (T. brucei), respectively. Northern blot analysis revealed that the Tr-CP gene was specifically expressed in T. rangeli as a 1.7 kb mRNA. A karyotype map of the chromosomes was also performed using pulsed-field gradient gel electrophoresis and Southern blot hybridization with these genes. T. rangeli has 14 chromosome bands ranging from 350 kb to 1.6 Mb, which were fewer in number and smaller in size compared with those from T. cruzi. The Tr-CP fragment and the Tr-DMR fragment hybridized with equal intensity on chromosome 1 (350 kb) and chromosome 2 (470 kb), respectively. These results suggest that non-pathogenic T. rangeli contains a conserved gene corresponding to the cysteine proteinase or a closely related enzyme, and that there is more than one copy of this gene, each found on different chromosomes.

Fungal metabolites. X. The effect of peptide antibiotics, trichosporin-Bs, on the respiratory activity of mitochondria

The effect of the trichosporin-Bs, peptide antibiotics, on the respiration of mitochondria was investigated. Trichosporin-Bs stimulated the respiratory rate of state 4 rat liver mitochondria in a dose-dependent manner. The maximum respiratory rate obtained by trichosporin-Bs was essentially the same as for 2,4-dinitrophenol and SF6847. Trichosporin-B-VIb released oligomycin-inhibited respiration of mitochondria. This means that trichosporin-Bs are uncouplers of oxidative phosphorylation. The stimulatory effect of trichosporin-B-VIb, a component of trichosporin-Bs, on mitochondrial respiration was increased by inorganic phosphate but not by other permeant anions studied. These results suggest that the stimulation of mitochondrial respiration by trichosporin-B-VIb is mediated by the same mechanism as is operating in the case of hypelcins and alamethicins. Furthermore, the relative potencies of trichosporin-Bs on the mitochondrial respiration and their relative hydrophobicities were examined. A clear relationship was observed between the uncoupling potencies of trichosporin-Bs and their relative hydrophobicities.

Fungal metabolites. XIII. Isolation and structural elucidation of new peptaibols, trichodecenins-I and -II, from Trichoderma viride

Three new groups of peptaibols, trichodecenins, trichorovins and trichocellins, have been isolated from conidia of the fungus, Trichoderma viride. The structures of trichodecenins-I and -II were established by positive-ion fast-atom bombardment, collision-induced dissociation mass spectrometry and two-dimensional NMR spectroscopy. Trichodecenins-I and -II have a (Z)-4-decenoyl group, six amino acid residues and a leucinol moiety in the molecules. Trichodecenin-II was synthesized by the solution-phase method.

Isolation and characterization of a novel gene encoding nuclear protein at a locus (D11S636) tightly linked to multiple endocrine neoplasia type 1 (MEN1)

To identify a gene responsible for multiple endocrine neoplasia type 1 (MEN1), we attempted to isolate potentially transcribable fragments from cosmid clones derived from a region on chromosome 11q13 where genetic linkage studies and analyses of loss of heterozygosity in MEN1-associated tumors have localized the MEN1 gene. By an exon-amplification method, we recovered three exon-like sequences from one of these clones, cCI11-367, and using these sequences as probes we were able to isolate new clones from cerebrum, cerebellum, and fetal-liver cDNA libraries. Sequence analysis of these cDNA clones revealed that the transcribed gene, designated ZFM1, encodes a novel 623-amino-acid protein containing domains with interesting structural properties including a nuclear transport domain, a metal binding motif, and glutamine- and proline-rich regions. Analysis by the reverse-transcriptase polymerase chain reaction (RT-PCR) indicated that this gene is expressed in various tissues including endocrine organs such as thyroid gland, pancreas, adrenal gland, and ovary. These data suggest that ZFM1 might be a candidate for mutations that cause MEN1.

Fungal metabolites. IX. Synthesis of a membrane-modifying peptide, hypelcin A-III, from Hypocrea peltata

A membrane-modifying peptide antibiotic having uncoupling activity on rat liver mitochondria, hypelcin A-III, has been synthesized by assembling five peptide fragments via the N,N'-dicyclohexylcarbodiimide method. The synthesized hypelcin A-III was identical with the natural product.

Identification and characterization of the tktB gene encoding a second transketolase in Escherichia coli K-12

We isolated a transposon Tn10 insertion mutant of Escherichia coli K-12 which could not grow on MacConkey plates containing D-ribose. Characterization of the mutant revealed that the level of the transketolase activity was reduced to one-third of that of the wild type. The mutation was mapped at 63.5 min on the E. coli genetic map, in which the transketolase gene (tkt) had been mapped. A multicopy suppressor gene which complemented the tkt mutation was cloned on a 7.8-kb PstI fragment. The cloned gene was located at 53 min on the chromosome. Subcloning and sequencing of a 2.7-kb fragment containing the suppressor gene identified an open reading frame encoding a polypeptide of 667 amino acids with a calculated molecular weight of 72,973. Overexpression of the protein and determination of its N-terminal amino acid sequence defined unambiguously the translational start site of the gene. The deduced amino acid sequence showed similarity to sequences of transketolases from Saccharomyces cerevisiae and Rhodobacter sphaeroides. In addition, the level of the transketolase activity increased in strains carrying the gene in multicopy. Therefore, the gene encoding this transketolase was designated tktB and the gene formerly called tkt was renamed tktA. Analysis of the phenotypes of the strains containing tktA, tktB, or tktA tktB mutations indicated that tktA and tktB were responsible for major and minor activities, respectively, of transketolase in E. coli.

[A case of advance colon cancer responding to sequential methotrexate and 5-fluorouracil therapy]

A 60-year-old female was diagnosed by X-ray examination and endoscopy as ascending colon cancer. Ultrasonography and computed tomography revealed two metastatic tumors in the liver. Abdominal surgery revealed peritoneal disseminations, massive lymph node metastasis and direct invasion of the transverse colon and ileum. From pathological examination the diagnosis was moderately differentiated adenocarcinoma. After right hemi-colectomy, sequential methotrexate and 5-fluorouracil therapy as well as oral administration of UFT, liver metastasis disappeared and no sign of ascites was found in this case. Complete response time was over 8 months. There have been no severe complications.

New nonradioactive microspheres and more sensitive X-ray fluorescence to measure regional blood flow

We developed new nonradioactive microspheres and used more sensitive X-ray fluorescence spectrometers than used previously to measure regional blood flow in the heart and other organs. We demonstrated the chemical stability of eight kinds of heavy element-loaded microspheres and validated their use for regional blood flow measurement by comparing duplicate flows measured with radioactive and/or nonradioactive microspheres in both acute and chronic dog experiments. The wavelength-dispersive spectrometer (Philips PW 1480) has a higher sensitivity than the previously described X-ray fluorescent system and reduced the number of microspheres required for accurate measurement. The fine energy resolution of this system makes it possible to increase the numbers of different kinds of microspheres to be quantitated, but at present only eight kinds are available. We also used a synchrotron radiation-excited energy dispersive spectrometer. The monochromatic synchrotron radiation allowed us to obtain much higher signal-to-background ratios of X-ray fluorescence spectra than with the wavelength-dispersive system (50 dB more for Zr-loaded microspheres) and will enable analysis of fluorescent activity in smaller regions (< 20 mg) than the radioactive method does.

Amplification of protein expression in a cell free system

Large quantities of a catalytically active protein have been produced in a cell free system. More than 10(9) copies of protein were produced from each DNA plasmid containing DNAfol, the bacterial gene encoding dihydrofolate reductase (DHFR). The strategy employed, denoted gene amplification with transcription/translation (GATT), involves sequential coupling of (i) DNA amplification by the polymerase chain reaction (PCR) and (ii) in vitro RNA transcription by T7 RNA polymerase, followed by (iii) translation of the run-off transcripts in a rabbit reticulocyte system. The protein product had the expected size (18 kDa) and catalyzed the NADPH-dependent reduction of 7,8-dihydrofolic acid to 5,6,7,8-tetrahydrofolic acid as efficiently as authentic DHFR. Potential applications of the strategy include large scale production of enzymes containing synthetic amino acids and facilitation of the characterization of the function of genes encountered in genomic mapping studies.

Responses to intravenous sedation by elderly patients at the Hokkaido University Dental Hospital

Geriatric patients who undergo intravenous sedation require careful intraoperative management, because respiratory and circulatory depression usually accompanies the administration of recommended adult sedative doses. This study examined results when a single benzodiazepine, diazepam or flunitrazepam, was carefully titrated to a clinical endpoint of conscious sedation. A total of 335 cases was divided into seven age groups. Mean sedative doses gradually decreased with age. The 60- to 69-yr group required about 75% of the adult recommended dose, the 70- to 79-yr group required 40% to 60%, and the 80- to 89-yr group required 30% to 45%. Pulse oximetry values also declined with age; respiratory depression was observed mainly in elderly patients. Declines in blood pressure after benzodiazepine administration were not correlated with age. The rise in blood pressure normally observed intraoperatively was suppressed both in young as well as old patients. We conclude that intravenous conscious sedation in elderly patients reduces stress-induced cardiovascular stimulation and that respiratory depression may occur at even low sedative doses.

Efficiency of particle-bombardment-mediated transformation is influenced by cell cycle stage in synchronized cultured cells of tobacco

Plasmid DNA pB1221 harboring beta-glucuronidase gene was delivered to synchronized cultured tobacco (Nicotiana tabacum L. cv Bright Yellow-2) cells of different cell cycle stages by a pneumatic particle gun. The cells bombarded at M and G(2) phases gave 4 to 6 times higher transformation efficiency than those bombarded at the S and G(1) phases.

Trichosporin-B-III, an alpha-aminoisobutyric acid-containing peptide, causes Ca(2+)-dependent catecholamine secretion from adrenal medullary chromaffin cells

We examined the effect of trichosporin-B-III, an alpha-aminoisobutyric acid-containing antibiotic peptide consisting of 19 amino acid residues and a phenylalaninol, on catecholamine secretion from cultured bovine adrenal chromaffin cells. Incubation of the cells with trichosporin-B-III (3-20 microM) caused an increase in the secretion of catecholamines. The secretion induced by trichosporin-B-III at low concentrations (3 and 5 microM) was completely dependent on external Ca2+, whereas that induced by higher concentrations (10 and 20 microM) was partly independent of Ca2+. Trichosporin-B-III at low concentration (5 microM) did not increase the release of lactate dehydrogenase, a marker enzyme of cytoplasm, from the cells. In contrast, the peptide at higher concentration (10 microM) increased the release of the enzyme. Trichosporin-B-III also caused both 45Ca2+ influx into the cells and an increase in the intracellular free Ca2+ concentration. The increases in catecholamine secretion and 45Ca2+ influx behaved similarly in relation to trichosporin-B-III concentration (3-10 microM). The time courses of the increases in secretion, 45Ca2+ influx, and intracellular free Ca2+ concentration induced by trichosporin-B-III were also quite similar. Trichosporin-B-III-induced (at 5 microM) secretion was not affected by the elimination of Na+ from the incubation medium or by the addition of tetrodotoxin, a blocker of highly selective voltage-dependent Na+ channels, or hexamethonium, a blocker of nicotinic acetylcholine receptors. On the other hand, both diltiazem (2-200 microM) and nicardipine (1-200 microM), blockers of voltage-dependent Ca2+ channels, inhibited the secretion induced by trichosporin-B-III (5 microM) in a concentration-dependent manner. Trichosporin-B-III-induced (at 5 microM) secretion also was suppressed by the addition of Mn2+ (5 mM) to the medium. The diltiazem (20 microM) inhibition of trichosporin-B-III-induced (at 5 microM) secretion was reversed by increasing the external Ca2+ concentration. These results indicate that trichosporin-B-III causes the secretion of catecholamines from bovine adrenal chromaffin cells by two mechanisms, Ca2+ dependent and Ca2+ independent (only at high concentrations of trichosporin-B-III). Furthermore, these results strongly suggest that trichosporin-B-III, in Ca(2+)-dependent secretion, activates endogenous voltage-dependent Ca2+ channels, or itself forms the channels in the membranes, and induces Ca2+ influx into the cells.

Evidence That More than 90% of beta-Glucuronidase-Expressing Cells after Particle Bombardment Directly Receive the Foreign Gene in their Nucleus

Plasmid DNA harboring the beta-glucuronidase (GUS) gene, coated on gold particles, was delivered into cultured tobacco (Nicotiana tabacum L. cv Bright Yellow-2) cells using a pneumatic particle gun. Cytological analyses of intracellular location of the introduced gold particles before and after GUS expression assay indicated that more than 90% of GUS-expressing cells after bombardment received a DNA-coated particle in their nucleus.

Transient expression of beta-glucuronidase in Arabidopsis thaliana leaves and roots and Brassica napus stems using a pneumatic particle gun

Successful transient expression of beta-glucuronidase (GUS) in Arabidopsis thaliana leaves and roots and Brassica napus stems was obtained after gene delivery with a pneumatic particle gun driven by compressed air. Effects of the pneumatic pressure used to accelerate the particles (accelerating pressure; 85 to 200 kg/cm2) and of preculture periods of plant tissues (0 to 6 days) on the efficiency of gene delivery were studied. In A. thaliana leaves, best results were obtained at 115 kg/cm2 of accelerating pressure and 3 days of preculture. In A. thaliana roots, the optimum was at 200 kg/cm2 of accelerating pressure and 3 days of preculture. These results indicate that both preculture period and accelerating pressure are vital factors that determine the efficiency of gene delivery by particle gun.

Gene delivery into cultured plant cells by DNA-coated gold particles accelerated by a pneumatic particle gun

Transient expression of the β-glucuronidase (GUS) gene in suspension-cultured cells of tobacco was obtained after gene delivery with a pneumatic particle gun device driven by compressed air. Both the pneumatic pressure used to accelerate the particles as well as the distance between the point of release of the particles from the device and the location of the target cells could be varied. Efficiency of gene delivery was tested by accelerating pressure from 63 to 200 kg/cm(2) and distances from 5 to 15 cm. At 150 kg/cm(2) and 10cm, 618±49 blue spots of GUS-expressing cells were evenly distributed over the surface of the cell layer (3.5 cm diameter). The frequency of transient gene expression was estimated to be more than 1.2×10(-3), which is comparable to, or even higher than, that obtained by the gunpowder-driven device.

Fungal metabolites. IV. Synthesis of an antibiotic peptide, trichosporin B-V, from Trichoderma polysporum

The antibiotic icosapeptide trichosporin B-V, which was isolated from Trichoderma polysporum, was synthesized by assembling five peptide fragments via the N,N'-dicyclohexylcarbodiimide method. The synthesized peptide was identical with the natural one.

5-Formyldeoxyuridine: a new type of DNA damage induced by ionizing radiation and its mutagenicity to salmonella strain TA102

An aqueous solution of calf thymus DNA was irradiated by 60Co gamma-rays and modified nucleosides produced in DNA were analyzed by high-pressure liquid chromatography coupled with a photodiode array UV detector. A new product with UV absorption maxima at 230 nm and 280 nm was observed. The structure of this compound was proposed to be 5-formyldeoxyuridine (f5dU) based on the mass spectrum of its trimethylsilyl derivative (M+, m/z472) and the structure was confirmed by chemical synthesis. The yield of f5dU (2.4/10(4) dT/krad) in DNA was of roughly the same order as that of 8-hydroxydeoxyguanosine and 5-hydroxymethyldeoxyuridine. Free f5dU was mutagenic to Salmonella typhimurium strain TA102: therefore f5dU incorporated into DNA may induce mutations.

Spotted fever group rickettsia in dogs in Japan

Prevalence of antibody against spotted fever group-rickettsia in dogs (14/134) from the northern part of Shikoku Island, where spotted fever group rickettsia infection in human is endemic, is significantly higher than that in dogs (4/189) from nonendemic areas.

[Surgical treatment of metastatic lung cancer from colorectal cancers]

Based on conclusions obtained after the observation of 61 colorectal cancer patients with a lung metastasis, the resection of lung metastasis as a therapy was evaluated. Among these 61 patients, only 5 patients had been identified as having a lung metastasis at the time of resection of the primary lesion, whereas the other 56 patients developed the lung metastasis after the curative resection of the colorectal cancer. Only one patient with a synchronous lung metastasis and twelve patients (eleven with a solitary metastatic lesion and one with multiple metastatic lesions) with metachronous lung metastasis underwent removal of the lung metastasis. The three-year survival rate was 65.2% in the metachronous group.

Chemical state analysis of sulfur and phosphorus in biological samples by X-ray fluorescence

Double-crystal high-resolution X-ray fluorescence spectroscopy was applied to the chemical state analysis of sulfur and phosphorus in biological samples of leaves and bones. Both S(2-) and S(6+) states are present in all leaves. In plants infected with the mosaic virus, the abundance of S(2-) state was found to be less than normal.Furthermore, the total sulfur content of leaves with the mosaic virus was less than that in normal leaves. From these results we have concluded that the mosaic virus is related to the decrease in cysteine sulfur (S(2-)), which is an essential component in amino acids. Most of the phosphorus in leaves and bones was found to be in P(5+) state. A small amount of P(3+) state, however, was also detected.

Comparison of SR-excited X-ray fluorescence analysis with neutron activation analysis for hair and fiber

Human scalp hair and some kinds of vegetable and animal fibers were analyzed by means of the SR excited X-ray fluorescence method (SRXFA) and the neutron activation method (NAA). Human hair samples collected from five males and five females were washed by the IAEA method prior to analysis. In the SRXFA analysis, samples were excited by monochromated X-rays. Fluorescence X-rays were measured by an Si(Li) detector. The elements detected in all hair samples were S, Ca, Cu, Fe, Zn, Br, and Sr. The elements K, Ti, Cr, Mn, Ni, Se, Hg, and Pb were also detected in several samples. After SRXFA analysis these same samples were analyzed by the NAA method. Elements such as Cu, Zn, and Br were detected by both methods, and their relative concentrations show a good agreement of variation between individuals. However, Pb was only detected by SRXFA, and Na, Au, and Sb were only detected by NAA. Therefore, these two methods are complementary to each other for trace element analysis.

X-ray fluorescence analysis using synchrotron radiation at the photon factory

X-ray fluorescence experiments at the Photon Factory in Japan are described. An energy-dispersive X-ray fluorescence system was combined with various excitation modes, i.e., a continuum and a monochromatic excitation, which consist of a crystal monochromator or a wide band pass monochromator. These excitation modes provide a wide range of band width and photon flux of excitation beams. Minimum detection limits obtained for a thin sample were less than 0.1 ppm and 0.1 pg when there was no line interference. Advantages of using monochromatic excitation are discussed, with emphasis on the possibility of chemical state analysis. Grazing incidence X-ray fluorescence is a technique very appropriate to synchrotron radiation characteristics. Near-surface analysis and trace analysis of solution samples placed on a total reflection support were made. Future plans are discussed, including microbeam analysis, tomography, X-ray excited optical fluorescence, and applications of insertion devices (undulator and wiggler).

[An ultrastructural study of the localization of alkaline phosphatase and Na-K ATPase in the labyrinth from the IUGR rat]

To elucidate the pathogenesis of intrauterine growth retardation (IUGR), the ischemic placentae produced by uterine artery and vein ligation were morphologically and histochemically investigated in rats. In the ischemic condition, fetal growth was remarkably retarded. The labyrinthi were atrophic and trophoblasts were degenerated ultrastructurally in association with mitochondrial swelling, increased microvesicles, dense bodies and fibrin deposition in the dilated intercellular spaces. Alkaline phosphatase and Na-K ATPase were localized on the plasma membrane in control rats. Na-K ATPase activity was observed in the basal side of cytotrophoblasts. However, the enzyme activities were decreased in the ischemic condition. The reaction products of horseradish peroxidase were present in the dilated intercellular spaces and increased cytoplasmic vesicles. These results suggest that in the ischemic condition, IUGR might be induced by the plasma membrane dysfunction following decreased enzyme activities and irregular distribution of horseradish peroxidase.

[Surgical treatment of colon cancer]

The treatment of early colon cancer limited lamina propria mucosa is endoscopic polypectomy. If invasion into the submucosal layer is present, usual colectomy with regional lymph adenectomy is indicated. Colon cancer without distant metastasis is treated by colectomy with regional lymph adenectomy. Right hemicolectomy, transverse colectomy, left hemicolectomy, and sigmoidectomy are indicated according to the location of the cancer. Five years survival rate for curative resection in 96 personal cases was 80.8%. Palliative resection was available to prolong the survival time. Mean survival time after palliative resection was 14 months, but in unresectable case it was 4 months.

Gene transfer into intact plant cells by electroinjection through cell walls and membranes

Tobacco mosaic virus (TMV) RNA was introduced directly into mesophyll cells of Nicotiana tabacum var. Samsun using electric-field pulses (electroinjection). The injected gene was successfully expressed in the recipient cells as judged by the assay for the virus coat protein using immunofluorescence and by the virus infectivity assay of the homogenate of the electroinjected cells for local lesions on tobacco leaves. As much as 50% of the cells that survived 24 days after electroinjection showed immunofluorescent specks.

A signal sequence mutant defective in export of ribose-binding protein and a corresponding pseudorevertant isolated without imposed selection

Ribose-binding protein is exported to the periplasmic compartment of Escherichia coli by a process that involves proteolytic cleavage of an amino-terminal extension of amino acids from the precursor form of the protein. In a collection of mutants isolated as defective in the Rbs transport system, a strain was identified that contained only precursor ribose-binding protein, none of which was exported to its normal location in the periplasm. The mutated rbsB contained a base substitution that results in a change of leucine to a proline at position-17 in the signal sequence. A pseudorevertant of the mutant contained proteolytically processed, active ribose-binding protein in the periplasm. The pseudorevertant rbsB carried a second mutation: serine at position-15 in the signal sequence was changed to phenylalanine. Isolation of a signal sequence mutant and a corresponding pseudorevertant without specific selection or site-directed mutagenesis emphasizes the possibility of obtaining export mutants without the use of procedures that could bias or limit the range of mutations found. Explanation of the extreme phenotype of the mutant and the effective correction of that phenotype in the pseudorevertant requires extension of current notions of critical features of signal sequences.

Molecular cloning and characterization of genes required for ribose transport and utilization in Escherichia coli K-12

We isolated spontaneous and transposon insertion mutants of Escherichia coli K-12 that were specifically defective in utilization or in high-affinity transport of D-ribose (or in both). Cotransduction studies located all of the mutations near ilv, at the same position as previously identified mutations causing defects in ribokinase ( rbsK ) or ribose transport ( rbsP ). Plasmids that complemented the rbs mutations were isolated from the collection of ColE1 hybrid plasmids constructed by Clarke and Carbon. Analysis of those plasmids as well as of fragments cloned into pBR322 and pACYC184 allowed definition of the rbs region. Products of rbs genes were identified by examination of the proteins produced in minicells containing various rbs plasmids. We identified four rbs genes: rbsB , which codes for the 29-kilodalton ribose-binding protein; rbsK , which codes for the 34-kilodalton ribokinase ; rbsA , which codes for a 50-kilodalton protein required for high-affinity transport; and rbsC , which codes for a 27-kilodalton protein likely to be a transport system component. Our studies showed that these genes are transcribed from a common promoter in the order rbsA rbsC rbsB rbsK . It appears that the high-affinity transport system for ribose consists of the three components, ribose-binding protein, the 50-kilodalton RbsA protein, and the 27-kilodalton RbsC protein, although a fourth, unidentified component could exist. Mutants defective in this transport system, but normal for ribokinase , are able to grow normally on high concentrations of the sugar, indicating that there is at least a second, low-affinity transport system for ribose in E. coli K-12.

Contrast echocardiography in detection of portopulmonary venous anastomosis

Portopulmonary venous anastomosis is a potential channel for systemic arterial embolization during embolization procedures for bleeding esophageal varices. To document the presence of such anastomoses, 15 patients with esophageal varices were studied by real-time contrast echocardiography combined with transhepatic cineportography. Cinefluorographic technique, which was applied for this purpose, occasionally failed to demonstrate the dynamic events in the left atrium because of rapid dilution of contrast medium. Echocardiography after the injection of dextrose solution into the gastric coronary vein allowed two-dimensional real-time images of contrast echoes in the left cardiac chambers. By combining these two methods, more reliable diagnostic information was obtained in five of the 15 patients studied.

Investigation of an intracellular hemolytic agent of Vibrio parahaemolyticus. Lipid fraction of dried cells

The dried cells of two strains of Vibrio parahaemolyticus were fractionated by extracting first with water and then with organic solvents. The hemolytic activity of the fractions was determined, and some of them were assayed for their effect in mice. The hemolytic agent present in the water-insoluble fraction was extractable in organic solvents such as 70% aqueous ethanol, chloroform-methanol-water (1:2:0.8) and acetone. The extracts showed no toxic effect in mice after intraperitoneal inoculation. No hemolytic activity was observed in the remaining cell residue, which bore the toxicity.