[Detection of Mycobacterium tuberculosis in transbronchial biopsy specimens by polymerase chain reaction]

Polymerase chain reaction (PCR) for the rapid detection of Mycobacterium tuberculosis was used to test 30 clinical specimens (transbronchial biopsy specimens) from patients in whom tuberculosis was suspected on chest X-ray. In these patients, 15 cases were histologically diagnosed as tuberculosis. Among them, M. tuberculosis was detected in 8 specimens by PCR. Of 8 PCR positive specimens, 7 were also positive by smear and culture; the other was negative by smear and positive by culture. On the other hand, 15 cases were therapeutically diagnosed as the tuberculosis and these specimens showed negative results in neither PCR nor microbiological tests. We conclude that the PCR method is useful for rapid and direct detection of M. tuberculosis in transbronchial biopsy specimens.

Detection of DNA of causative agent of spotted fever group rickettsiosis in Japan from the patient's blood sample by polymerase chain reaction

The polymerase chain reaction (PCR) was applied for the etiological diagnosis of spotted fever group (SFG) rickettsiosis in Japan. Nucleotide primers derived from the 17-kDa antigen gene of Rickettsia rickettsii primed a rickettsia-specific 246-base-pair product for all of the Katayama, Abe, Misaka and Kojima strains, which we had isolated previously. Moreover, we were able to detect the same product by PCR amplification from the peripheral blood of a patient in the acute stage of the illness. The PCR method is considered to be useful for rapid etiological diagnosis of SFG rickettsiosis in Japan.

Novel theta class glutathione S-transferases Yrs-Yrs' and Yrs'-Yrs' in rat liver cytosol: their potent activity toward 5-sulfoxymethylchrysene, a reactive metabolite of the carcinogen 5-hydroxymethylchrysene

Two novel theta class glutathione S-transferases (GSTs), designated Yrs-Yrs' and Yrs'-Yrs', were isolated from rat liver cytosol and purified to homogeneity. Polyclonal antibody raised against the previously reported theta class GST Yrs-Yrs (Hiratsuka, A. et al., J. Biol. Chem. 265, 11973 (1990)) cross-reacted with GSTs Yrs-Yrs' and Yrs'-Yrs'. These three theta class GSTs had different pI values and were separated by chromatofocusing. The enzyme subunit Yrs' was separated from Yrs by reverse partition HPLC, but identical to Yrs in the first 37 N-terminal amino acid sequence. Like GST Yrs-Yrs, both GSTs Yrs-Yrs' and Yrs'-Yrs' were not retained on an S-hexyl-GSH affinity column and had little activity toward 1-chloro-2,4-dinitrobenzene. However, they showed potent activities toward the reactive sulfate ester of the carcinogen, 5-hydroxymethylchrysene. GSTs Yrs-Yrs and Yrs'-Yrs' showed much higher GSH peroxidase activities toward arachidonate hydroperoxide than did rat liver alpha class GST Ya-Ya.

HIV type 1 infection of CD4+ T cells depends critically on basic amino acid residues in the V3 domain of envelope glycoprotein 120

The third variable domain (V3 domain) of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 is a major determinant of phenotypic variability. The V3 domain of HIV-1 has many basic amino acid residues. Lymphocytotropic HIV-1 tends to have a V3 domain with a higher density of positive charge than does monocytotropic HIV-1. The importance of basic residues in the V3 domain for the HIV-1 infectivity, however, has not been well investigated. Here we show that mutation of basic amino acid residues at positions 303, 306, 309, 313, and 325 in the V3 domain of the lymphocytotropic isolate NL4-3 results in a dramatic elimination of both virus infectivity and syncytium-inducing ability. Three basic amino acid substitutions (at position 306, 309, and 313) induced a decrease in the binding ability of two kinds of neutralizing antibodies (NEA9284 and 0.5 beta) that recognize a different site in the V3 domain. This suggests that the basic residues play an important role in maintaining the tertiary structure of the V3 domain. Monocytotropism was not simply dependent on either decreased positive charge in the V3 domain of NL4-3 or on mutation of lysine to glutamate at position 320, which is a characteristic amino acid of monocytotropic HIV-1. These findings contribute to our understanding of the significance of basic residues on the function of envelope glycoprotein.

A novel in vitro assay system for transendothelial tumor cell invasion: significance of E-selectin and alpha 3 integrin in the transendothelial invasion by HT1080 fibrosarcoma cells

The interaction of tumor cells with endothelial cells is a key event in tumor metastasis. We established an in vitro invasion assay system, in which the invasion of tumor cells after interaction with endothelial cells can be examined. Two chamber culture wells separated by porous membrane were used. Human umbilical vein endothelial cells (HUVEC) were placed on porous membranes coated with matrix components. The invasion by HT1080 fibrosarcoma cells was determined in this system by counting the number of cells that moved through the membranes from upper to lower chambers. HUVEC cells did not migrate through the membranes as judged by the staining with UEA-I. Observation by scanning electron microscopy revealed that HT1080 cells bound to HUVEC surfaces and migrated underneath the HUVEC monolayer. Effects of antibodies specific for cell surface adhesion molecules on the migration of HT1080 cells were examined. Invasion of uncoated membranes and membranes coated with HUVEC cells was compared. Antibody against E-selectin significantly suppressed an increase of HT1080 cell invasion of HUVEC monolayers stimulated by IL-1 beta or TNF alpha. Antibody against integrin alpha 3 subunit remarkably inhibited the invasion of HUVEC cell-coated membranes, suggesting that integrins with the alpha 3 subunit may play an important role in the transendothelial invasion by HT1080 cells.

Inhibition of vasoactive amine induced contractions of vascular smooth muscle by hydrogen peroxide in rabbit aorta

OBJECTIVE

The aims were to investigate the effects of H2O2 on arterial contractions induced by vasoactive amine agonists and a high concentration of potassium ions (high K+) in vitro and to explore the possible underlying mechanism(s) involved.

METHODS

Isometric tension of rabbit isolated aortic strips was measured and the effects of pretreatment with H2O2 on contractions induced by phenylephrine and high K+ were compared. The effects of H2O2 on precontracted strips were determined in the presence and absence of the aortic endothelium and compared with those of acetylcholine.

RESULTS

The tension developed in response to an agonist was expressed as a percentage of the contraction induced by high K+ (64.7 mM) superfusion. Pretreatment with 300 microM H2O2 reduced the mean phenylephrine (0.3 microM) induced contraction from 96.2(SEM 1.4) to 61.8(2.8)%; the effect was stable and reversed by washing out the H2O2. Hydrogen peroxide relaxed phenylphrine precontracted strips with and without endothelium but it showed no relaxant effect when the strips were precontracted by high K+, whereas acetylcholine (1 microM) induced transient relaxation of high K+ precontracted strips by 27.8(2.9)%. The relaxant effect of H2O2 was not affected by pretreatment with indomethacin (a cyclo-oxygenase inhibitor), desferrioxamine (a hydroxyl radical scavenger), or diphenylphenylenediamine (a lipophilic antioxidant).

CONCLUSIONS

H2O2 inhibits vasoactive amine induced contractions of the vascular smooth muscle of rabbit aorta in vitro without affecting voltage dependent Ca2+ influx or contractile machinery. The mechanism responsible for its inhibitory effects may be related to impairments of the cellular signalling reactions initiated by the agonists.

Novel potassium-channel openers: preparation and pharmacological evaluation of racemic and optically active N-(6-amino-3-pyridyl)-N'-bicycloalkyl-N"-cyanoguanidine derivatives

The previous paper reported on the synthesis and pharmacological evaluation of N-(6-amino-3-pyridyl)-N'-bicycloalkyl-N"-cyanoguanidine derivatives, from among which three compounds were selected as potent potassium-channel openers. In the present study, selected compounds were tested for antagonism of potassium-induced contraction of rat aorta, hypotensive activity in normotensive rats, and diuretic activity in spontaneously hypertensive rats. This led to further evaluation of compound (+/-)-10 and selection of (+)-N-(6-amino-3-pyridyl)-N'- [(1S,2R,4R)-bicyclo- [2.2.1]hept-2-yl]-N"-cyanoguanidine ((+)-10) (AL0670) for development as an antihypertensive agent. Although AL0670 is regarded as a pinacidil-type K(+)-channel opener, it showed different pharmacological and conformational profiles from pinacidil.

[A case of anaphylaxis caused by sunflower seed]

A 14 years old boy experienced an anaphylactic reaction of dyspnea, vomiting, urticaria and hypotension after he ate sunflower seeds. Specific IgE-mediated hypersensitivity to sunflower seen extract was demonstrated by skin tests and radioallergosorbent test (RAST). By immunoblotting test analysis (SDS-PAGE, Western blotting method), the allergenic activity of sunflower seem were shown to be in the MW range of 13.5 Kd.

Sequence analysis of the flgA gene and its adjacent region in Salmonella typhimurium, and identification of another flagellar gene, flgN

The flagellar genes flgA and flgM are located at the terminus of the region-I flagellar gene cluster on the chromosome of Salmonella typhimurium. The flgA gene is involved in P-ring formation of the flagellar basal body, whereas flgM encodes the anti-sigma factor which acts as a negative regulator of the flagellar regulon. The nucleotide sequence of the DNA fragment containing these flagellar genes and the adjacent region was determined. The flgA gene was found to encode a 219-amino-acid (aa) protein of 23,556 Da. The N-terminal region of FlgA has the characteristics of a typical signal sequence, suggesting that FlgA may function in the periplasmic space where P-ring assembly takes place. The flgM gene was found to constitute an operon together with an ORF which encodes a 140-aa protein of 15,899 Da. A gene disruption mutant was constructed by inserting a cat gene cartridge into the ORF on the chromosome. This mutant showed only weak motility, indicating that the product of the ORF is involved in flagellar formation. Therefore, this ORF was designated as flgN. Electron microscopic observation revealed that most of the flagellar structures produced by the flgN mutant are hook-basal body complexes lacking the filament portions. Based on these results, we concluded that the flgN product is required for the efficient initiation of filament assembly.

[Surgical treatment of a long-term decubitus ulcer]

A 64-year-old male presented with a large decubitus ulcer of the sacrum which had not healed for thirteen years in spite of various conservative treatments. His primary disease was paraplegia following spondylitis. Although he was not ambulatory, he was able to manage a wheelchair. The decubitus, which had a 8 x 13 cm dead space, was successfully closed with a single operation using two fasciocutaneous flaps. The patient was discharged two months postoperatively. The medical cost of his treatment before and after the surgery was investigated. The expense including the surgery and postoperative care until discharge was five times more than the monthly cost of the preoperative period. These findings suggest that a decubitus ulcer which does not respond to conservative treatments for more than several months should be considered for a surgical management, as long as the patient's general condition permits an operation.

A unique murine CD43 epitope Lp-3: distinct distribution from another CD43 epitope S7

In foregoing studies, we found a unique B cell differentiation antigen Lp-3 which is expressed on pre-B and premature B cells in the bone marrow, but is negative on bone marrow mature B cells and peripheral resting B cells. Nonetheless, Lp-3 was clearly positive on the majority of CD5 B(B1) cells. When we examined the biochemical nature and partial amino acid sequences of purified 132-kDa Lp-3 molecules and the nucleotide sequence of the cDNA clones, we found that Lp-3 is an epitope of CD43. Thus, the monoclonal antibody (mAb) Lp-3 may be the first mAb to murine CD43 defined by primary target structure analysis. Comparison of tissue distribution of Lp-3 and S7, an epitope previously suggested to associate with murine CD43, showed that they were similarly distributed on thymocytes, peripheral B and T cells, granulocytes, and platelets. In the bone marrow, while both Lp-3 and S7 were negative on mature B cells, the former was positive on all B lineage cells at an early ontogeny and the latter was positive only on the minor population of pre-B cells and pro-B cells. Lp-3 and S7 epitopes also showed different distributions on basement membranes of renal glomerulus, bronchus, and endometrium, lining cells of choroid plexus and muscular cells of arterioles in a variety of tissues. As CD43 has various isoforms generated by different degrees of glycosylation of the common core peptide, it is likely that Lp-3 and S7 are associated with different CD43 isoforms.

Cytochrome c electronic structure characterization toward the analysis of electron transfer mechanism

Seventy-four kinds of cytochrome c sequences have been compared in order to determine the conserved residues and residues of which the characters are conserved. Twenty-three residues are invariant throughout all the aligned sequences, while the residues at 17 other positions share common characters. The prosthetic group as well as these conserved and character-conserved residues are considered to constitute a model molecule to elucidate the electron transfer process in cytochrome c. Their coordinates in the structure of tuna cytochrome c are extracted, and an extended Hückel molecular orbital calculation has been executed on this molecule. The examination of the shapes and the energy levels of the resulting MOs has suggested that three nearly degenerate HOMOs might play an important role in the electron transfer. These HOMOs are exposed to the protein surface around the heme, Cys-17, and Phe-82. A delocalized electron system developing in these regions is proposed to be the electron transfer pathway of cytochrome c.

Circular dichroism of metaiodopsin II and its binding to transducin: a comparative study between meta II intermediates of iodopsin and rhodopsin

Through low-temperature absorption and circular dichroism (CD) spectroscopies, and G-protein (transducin) binding experiments, we have investigated molecular properties of the meta II intermediate of iodopsin, a cone visual pigment present in chicken red-sensitive cones. The meta II intermediate of iodopsin (metaiodopsin II, lambda max = 390 nm) displayed a positive CD band at about 390 nm and a large negative CD band below 300 nm. It dissociated into all-trans-retinal and the protein moiety. A long-lived intermediate corresponding to the meta III intermediate of rhodopsin was not observed in iodopsin, under our experimental conditions. Decay of metaiodopsin II was significantly suppressed in the presence of transducin, but not in the presence of both transducin and GTP, indicating that metaiodopsin II can interact with transducin and activate it. Both metaiodopsin II and metarhodopsin II displayed a large negative CD band below 300 nm. This fact suggested that during the formation of both meta II intermediates, some aromatic amino acid residues and/or a disulfide bond are rearranged, which may be important for expression of catalytic activity for exchange of GDP to GTP on transducin. On the other hand, metaiodopsin II decayed more than 10 times faster than metarhodopsin II. This fact may be one of the reasons why cones are less photosensitive than rods.

Subtypes of endothelin ETA and ETB receptors mediating venous smooth muscle contraction

In rabbit saphenous vein, endothelin (ET)-1 and ET-3 induced sustained contractions whereas the selective agonists of the ETB receptor, sarafotoxin S6c (STXc) and IRL 1620, induced transient contractions. In the presence of an ETA antagonist, BQ-123, contractions induced by ET-1, STXc and IRL 1620 did not change whereas ET-3 induced only transient contraction. The ETB antagonists, RES-701-1 and IRL 1038, only weakly antagonized the effects of these stimulants. In the muscle pretreated with STXc, neither STXc nor IRL 1620 was effective whereas ET-3 induced sustained contraction at higher concentrations than ET-1. In the muscle pretreated with STXc, BQ-123 weakly antagonized the effect of ET-1 and abolished the effect of ET-3. These results suggest that there are two types of ET receptors; less tachyphylactic and isopeptide-selective ETA receptor, and tachyphylactic and isopeptide-nonselective ETB receptor. The ETA receptors may be further classified as a BQ-123-sensitive ETA1 and a BQ-123-insensitive ETA2 subtypes. The ETB receptors may also be subclassified as the ETB1 and ETB2 subtypes based on the sensitivity to the ETB antagonists.

Murine granulated metrial gland cell population in beige (bg/bg) and SCID (scid/scid) genotypes

Morphology of granulated metrial gland (GMG) cell, a uterine natural killer (NK) cell, was reported to be normal in pregnant uteri of NK cell-deficient mice and T-cell- and B-cell-deficient mice, but little is known about the number of GMG cells. To determine whether the number of GMG cells is influenced by such mutations, their number in the bg mice (genotype C57BL/6J-bg/bg) and SCID mice (genotype C.B-17/Icr-scid/scid) was compared to that of control mice on day 12 of gestation. GMG cells in these mutant mice were normal in number. Thus, the present results support the previous reports that GMG cells can differentiate normally in bg mice and that the GMG cell differentiation is not affected by functional T- nor B-cells.

Na-K-ATPase activity in the guinea pig stria vascularis in experimentally-induced endolymphatic hydrops

The effect of endolymphatic hydrops on the Na-K-ATPase activity in the guinea pig stria vascularis was electron microscopically and enzyme cytochemically investigated one year after experimental induction. The morphological observations revealed intercellular dropsy in the basal infoldings of the marginal cells, and shrinkage and disappearance of intermediate cells. Moreover, shrinkage of the marginal cells, especially of the basal infoldings, was occasionally observed. In spite of these morphological alterations, the Na-K-ATPase activity was still detected on the plasma membrane of the basal infoldings of most marginal cells. No remarkable differences were found among the cochlear turns of the specimens examined. However, no reaction product was detected on the basolateral plasma membrane of severely degenerated marginal cells. The present results indicate that the Na-K-ATPase of the plasma membrane of the basal infoldings of the marginal cells plays an important role in the maintenance of the unique ion concentration of the endolymph even in the endolymphatic hydropic condition, and that the Na-K-ATPase activity is attenuated in severely atrophic cells.

[Aggressive transformation of an indolent myeloma with abdominal extramedullary plasmacytoma after 6-year period of observation]

62-year-old female, who had been under observation for an indolent myeloma for six years without therapy, was admitted because of left flank pain. Various imaging modalities disclosed left pleural effusion, and a huge abdominal tumor involving the left crus of the diaphragm, spleen, stomach, pancreatic tail, left adrenal gland, left kidney and left posterior abdominal wall. Morphological and immunological examinations revealed extensive proliferation of more anaplastic myeloma cells within the tumor and in the pleural effusion than those in bone marrow on admission or at the beginning of the period of observation. Chemotherapy reduced serum M-protein, but LDH, the volume of the pleural effusion, and the size of the tumor increased. She died of pancreatitis associated with massive bleeding from the gastric tumor. Renal function was well preserved until her terminal phase. The clinical course showed the progression of indolent myeloma into an aggressive one without chemotherapeutic intervention, implying a rare subtype in terms of the natural history of multiple myeloma.

[Coronary artery bypass grafting for a patient with single coronary artery]

A 47-year-old man was admitted with suddenly developed chest pain. Coronary arteriography could not identify the right coronary orifice at the right coronary sinus. Left coronary arteriography revealed that the right coronary artery originated from a proximal segment of the left anterior descending artery with subtotal obstruction at the segment just distal to the bifurcation of the right and anterior descending arteries. Coronary artery bypass grafting to the middle segment of the left anterior descending artery was carried out with satisfactory result. To our knowledge, only seven cases with a diagnosis of single coronary artery who underwent coronary artery bypass grafting have been reported.