Molecular cloning of the antibacterial protein of the giant African snail, Achatina fulica Férussac

An expression cDNA library was constructed with poly(A)-rich RNA extracted from the collar of the giant African snail, Achatina fulica Férussac. A 1.9-kbp cDNA clone encoding a precursor of antibacterial glycoprotein of the snail, achacin, was isolated from the cDNA expression library. The cDNA sequence contains an open reading frame with 1593-nucleotide residues. The deduced amino acid sequence of this achacin precursor starts with a 29-residue leader peptide followed by a 502-residue mature peptide (56 kDa) with four possible N-glycosylation sites, Asn-Xaa-Ser or Asn-Xaa-Thr. The Northern-blot analysis proved that the achacin precursor was specifically expressed in the tissue of snail collar and processed to mature achacin. cDNA inserts encoding achacin precursor were subcloned into expression plasmids. Three kinds of expressed polypeptides were cross-reacted with rabbit antiserum raised against achacin. The largest polypeptide (M(r) 63,000) should be the achacin precursor.

Resistance of the melibiose carrier to inhibition by the phosphotransferase system due to substitutions of amino acid residues in the carrier of Salmonella typhimurium

The melibiose carrier of Salmonella typhimurium is under the control of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS). We isolated mutants of the melibiose carrier that showed resistance to inhibition via the PTS. Growth of the mutants on melibiose was not inhibited by 2-deoxyglucose, a non-metabolizable substrate of the PTS, although growth of the parent strain was inhibited. Transport activity of the melibiose carrier in the mutants was fairly resistant to inhibition by 2-deoxyglucose, although the activity in the parent was sensitive to inhibition. We cloned the mutated melB gene that encodes the melibiose carrier, determined the nucleotide sequences, and identified replaced nucleotides. The mutations resulted in substitutions of Asp-438 with Tyr, Arg-441 with Ser, or Ile-445 with Asn. All of these residues are in the COOH-terminal region of the carrier. The secondary structure of this region is predicted to be an alpha-helix, and the mutated residues were on the same side of the helix. This region showed sequence similarity to a region of the MalK protein, in which substitution of amino acid residues also resulted in PTS-resistant mutants. Thus the COOH-terminal portion of the melibiose carrier is important for the interaction of dephosphorylated IIIGlc, which is an entity causing reversible inactivation of the carrier.

The complete sequence of African horsesickness virus serotype 4 (vaccine strain) RNA segment 5 and its predicted polypeptide compared with NS1 of bluetongue virus

The complete sequence of RNA segment 5 of the African horsesickness virus serotype 4 (AHSV-4) vaccine strain was determined from cDNA clones inserted into pBR322. The RNA is 1751 bp long (M(r) 1.12 x 10(6)) and contains an open reading frame encoding a protein of 548 amino acids (M(r) 63,122) with a net charge of +0.5 at neutral pH. A comparison of the sequence of AHSV-4 segment 5 with that of segment 6 of bluetongue virus (BTV) serotypes 10 and 17 revealed 49.2% and 48.9% nucleotide similarity, respectively, and 31.4% amino acid similarity. However, AHSV-4 segment 5 has no significant similarity to BTV segment 5. In addition, Northern blot hybridization showed that full-length AHSV-4 segment 5 cDNA cross-hybridized with the corresponding genes of all serotypes of attenuated AHSV.

[A survey of annual radiation dose for radiation workers from occupational and medical exposures in Kyushu]

This study was carried out to determine annual dose equivalents of exposure in workers exposed to medical radiation and occupational radiation in an enterprise associated with nuclear power plants. The results indicated that medical exposure is much higher than occupational exposure. Average annual effective dose equivalents for medical and occupational exposure were 4.0-7.5 mSv and 2.4-3.6 mSv, respectively. Individual occupational exposure limits have been well controlled and maintained at one-fifth of the dose limit for radiation workers (50 mSv/yr). On the other hand, medical exposure in the older workers of this enterprise has been increasing as a result of X-ray diagnosis with barium meal.

Synthesis of 5-deoxy-5-fluoro and 5-deoxy-5,5-difluoro derivatives of kanamycin B and its analogs. Study on structure-toxicity relationships

5-Deoxy-5-fluoro- (1), 5.3'-dideoxy-5-fluoro- (2), and 5,3',4'-trideoxy-5-fluoro-kanamycin B (3) have been prepared by treatment of 5-epihydroxyl precursors (prepared by the Mitsunobu reaction) with DAST as the key step. 5,3'-Dideoxy-5,5-difluoro- (26) and 5,3',4'-trideoxy-5,5-difluoro-kanamycin B (27) were also prepared by treatment of the corresponding 5-oxo derivatives with DAST. These 5-deoxy-5-fluoro and 5-deoxy-5,5-difluoro derivatives showed markedly decreased toxicity as compared with the parent compounds.

Detection of contact sensitivity of metal salts using the murine local lymph node assay

The local lymph node assay (LLNA) is a predictive test for the detection of contact allergens. Nickel and chromium sensitization are common cases in man. However, in a previous study topical application of nickel sulfate and potassium dichromate in aqueous solution failed to induce activation in the draining lymph node. This study describes the application of LLNA to evaluate the contact sensitivity of metal salts. The metal salts were applied in dimethylsulfoxide or aqueous ethanol solution. In some experiments, the skin of the ears was gently abraded using a needle prior to application of metal salts. The ability of seven metal salts to induce lymph node cell (LNC) proliferation was compared. Nickel, cobalt, chromium and copper salts increased LNC proliferation, whereas zinc, manganese and iron salts failed to induce LNC proliferation in this assay.

Efficacy of percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction complicated by cardiogenic shock

Cardiogenic shock still remains a highly lethal complication of acute myocardial infarction (AMI). This study reviews our hospital experience in treating AMI complicated by cardiogenic shock to evaluate whether coronary angioplasty improves survival or not. We have treated 523 AMI patients from 1985 to 1990, and among these, 26 patients with AMI complicated by cardiogenic shock who underwent percutaneous transluminal coronary angioplasty (PTCA) compose the study group. In 16 patients, PTCA was successful (Groups S) and in 10 patients, unsuccessful (Group F). There were no statistical differences between the Groups with respect to clinical background, intraaortic balloon counterpulsation (IABP) or emergency coronary bypass graft surgery. Before PTCA, hemodynamic variables including cardiac index, pulmonary capillary wedge pressure and systolic blood pressure were similar in the 2 groups. After PTCA, cardiac index in Group S patients was better than in Group F patients (2.18 +/- 0.61 versus 1.62 +/- 0.65, p less than 0.05). Thirty day and 1 year survivals were also better in Group S than in Group F (30 day survival: Group S 56.2%, Group F 10%, 1 year survival: Group S 31.2%, Group F 0%, p less than 0.05). Multivariate analysis showed that age under 75 years old, systolic blood pressure over 90 mmHg after PTCA and successful PTCA were independent predictors of 30 day survival (p less than 0.05). It was suggested that PTCA was an effective procedure to reduce mortality in patients with cardiogenic shock.

Synthesis of 4'-deoxy-4'-fluorokanamycin A and B

4'-Deoxy-4'-fluorokanamycins A (17) and B (25) have been prepared through fluorinative ring-opening of the D-galacto-3',4'-oxiranes (8 and 21) derived from kanamycin A and B with potassium hydrogenfluoride in ethane-1,2-diol. The mechanism of preponderant formation of the 4'-deoxy-4'-fluoro-D-gluco (9 and 22) over the 3'-deoxy-3'-fluoro-D-gulo derivatives was discussed. In the synthesis of 25, the unusual 3',6'-epimine (23) was the main product along with the 4'-deoxy-4'-fluoro derivative. The mechanism of this reaction is also discussed. Both 17 and 25 were active against resistant bacteria producing aminoglycoside-adenylylating enzymes for HO-4'.

[Perioperative management for type A acute aortic dissection]

Twenty nine cases of type A acute aortic dissection were subjected to a retrospective study concerning perioperative management. Two keys pointed out for the management were as follow; (1) An optimal control of blood pressure is the most important measure to avoid advance of aortic dissection or rupture of dissecting aneurysm. Both pericardiac tamponade and aortic valve insufficiency should be taken care of from their onset, since they are often complicated after aortic dissections and their onset is fatal. (2) Separated brain perfusion and profound hypothermia with total circulatory arrest might involve a high risk of inducing postoperative brain damage and mortality, especially for old patients.

Cloning and sequencing of the melB gene encoding the melibiose permease of Salmonella typhimurium LT2

The nucleotide sequence of the melB gene coding for the Na+ (Li+)/melibiose symporter of Salmonella typhimurium LT2 was determined, and its amino acid sequence was deduced. It consists of 1428 bp, corresponding to a protein of 476 amino acid residues (calculated molecular weight 52,800). The amino acid sequence is homologous to that of the melibiose permease of Escherichia coli K12, with 85% identical residues. All, except one, of the amino acid residues that have been reported to be important for cation or substrate recognition in the melibiose permease of E. coli are conserved in the melibiose permease of S. typhimurium. In addition, part of the sequence resembles the lactose permease of Streptococcus thermophilus, the animal glucose transporter (GLUT1), the plasmid-coded raffinose permease (RafB), and the NADH-ubiquinone oxidoreductase chain 4 (Nuo4) of Aspergillus amstelodami.

Role of endothelium-derived nitric oxide in myocardial reactive hyperemia

In pentobarbital sodium-anesthetized dogs we investigated the role of the endothelium-derived nitric oxide and adenosine in the regulation of the coronary blood flow during myocardial reactive hyperemia. Repayments of flow debt after 10-, 20- and 60-s occlusion of the left circumflex coronary artery (LCX) were measured before and after infusion of NG-monomethyl-L-arginine (L-NMMA; n = 15), 8-phenyltheophylline (8-PT; n = 5), and both L-NMMA and 8-PT (n = 5) into the LCX. Infusion of L-NMMA (2 mumol/min, for 20 min) reduced repayments of flow debt after 10-, 20-, and 60-s LCX occlusion by 30 +/- 4 (P less than 0.01), 34 +/- 3 (P less than 0.01), and 14 +/- 3% (P less than 0.01), respectively. Infusion of 8-PT (0.75 mumol/min for 15 min) also reduced these repayments of flow debt by 31 +/- 7 (P less than 0.01), 30 +/- 7 (P less than 0.01), and 34 +/- 6% (P less than 0.01), respectively. Simultaneous infusion of L-NMMA and 8-PT significantly attenuated the peak reactive flow rate and reduced repayment of flow debt after 20-s LCX occlusion by 57 +/- 1% (P less than 0.001), and this reduction in repayment of flow debt was significantly greater than each of those by the individual administration of L-NMMA and 8-PT (both P less than 0.01). The suppressive effect of L-NMMA on repayment of flow debt after 20-s LCX occlusion was quickly reversed by the infusion of L-arginine (3 mg/min for 10 min; n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Study on fluorination of 2,3-dideoxy-2,3-(N-tosylepimino)-alpha-D-allopyranosides, and synthesis of 3'-deoxy-3'-fluorokanamycin B and 3',4'-dideoxy-3'-fluorokanamycin B

Reaction of the structurally rigid methyl 2,3-dideoxy-4,6-O-isopropylidene-2,3-(N-tosylepimino)-alpha-D-a llopyranoside (6) with KHF2 in DMF at 150 degrees gave initially methyl 2,3-dideoxy-2-fluoro-4,6-O-isopropylidene-3-tosylamido-alpha-D-altrop yranoside (10) by N-tosylepimine-ring opening, and 10 was gradually converted into the stable methyl 2,3-dideoxy-3-fluoro-4,6-O-isopropylidene-2-tosylamido-alpha-D-glucopyra noside (11). A reversible mechanism involving 6 and 10 has been proposed. In the mobile methyl 2,3-dideoxy-2,3-(N-tosylepimino)-alpha-D-allopyranoside (7) and the corresponding 4,6-di-O-acetyl (8) and -di-O-methyl derivatives (9), reactions with KHF2 proceeded comparatively rapidly giving the corresponding 3-deoxy-3-fluoro-alpha-D-glucopyranosides as the major products. A slightly different reaction mechanism for the mobile compounds has been proposed. By application of this study, 3'-deoxy-3'-fluorokanamycin B was prepared by treatment of 4",6"-O-cyclohexylidene-2'-deamino-3'-deoxy-3'-epi-6'-N-methoxycarbonyl- 1,3, 3"-tri-N-tosyl-2',3'-(N-tosylepimino)kanamycin B (21) with KHF2 as the key reaction. 3',4'-Dideoxy-3'-fluorokanamycin B was also prepared. Both compounds were active against resistant bacteria producing 3'-modifying enzymes.

Preferential utilization of glucose over melibiose, and vice versa, in a pts mutant of Salmonella typhimurium

Preferential utilization of glucose and melibiose was investigated in wild type cells and in pts mutant (ptsI-leaky) cells of Salmonella typhimurium. A typical diauxic growth and preferential utilization of glucose over melibiose were observed in wild type cells when these two sugars were added as carbon source. Similar results were obtained with a pts mutant (SB1476) although utilization of glucose was slow. When cyclic adenosine 3',5'-monophosphate (cAMP) was added to the culture medium to release the catabolite repression, preferential utilization of glucose was still observed in wild type cells. With glucose-induced mutant cells, preferential utilization of glucose was observed in the presence of cAMP. Gradual utilization of melibiose took place when glucose concentration in the medium decreased. Surprisingly, preferential utilization of melibiose over glucose was observed with melibiose-induced and glucose-uninduced mutant cells in the presence of cAMP.

Cloning and nucleotide sequence of the gene (citC) encoding a citrate carrier from several Salmonella serovars

The nucleotide sequence of the citC coding for the citrate carrier in several Salmonella serovars has been determined, and the amino acid sequence of the carrier protein was deduced. The predicted citrate carrier from Salmonella pullorum and Salmonella enteritidis consists of 446 amino acids with a molecular weight of 47,621, whereas that from Salmonella dublin is the same 446 amino acids with the slightly different molecular weight of 47,591, because 1 amino acid residue was substituted. The predicted proteins are highly hydrophobic (69% nonpolar amino acids). The hydropathy profile suggests that the proteins are composed of 11-12 hydrophobic membrane-spanning segments with two hydrophilic cores in the middle of the protein sequence. No homology in the nucleotide and amino acid sequences was found in the molecular structures of citA, citP, and tctI genes. The citC-coding citrate transport activity is Na(+)-dependent and specific for citrate only. The transcript from the citC gene was not detected in the total RNA from several Salmonella serovars except S. dublin in Northern blot analysis, although the promoter of the citC genes appeared to be functional in Escherichia coli and Salmonella typhimurium strains using the lacZ fusion assay. These results suggested that the citC gene-coding citrate carrier is probably a TctIII system such as that identified previously in S. typhimurium.

Mapping of antigenic sites to monoclonal antibodies on the primary structure of the F1-ATPase beta subunit from Escherichia coli: concealed amino-terminal region of the subunit in the F1

To analyze relationships between the ternary and primary structures of the beta subunit of Escherichia coli F1 ATPase, we prepared two monoclonal antibodies beta 12 and beta 31 against the beta peptide. These antibodies bind to the beta subunit but do not bind to the F1 ATPase, resulting in no inhibition of the ATPase activities. Several different portions of the beta subunit peptide were prepared by constructing expression plasmids carrying the corresponding DNA segment of the beta subunit gene amplified by the polymerase chain reaction. Western blotting analysis using these peptides revealed that the antibodies bound to a peptide of 104 amino acid residues from the amino terminal end, which is outside the previously estimated catalytic domain between residues 140 and 350. These results indicated that the amino terminal portion of the maximal 104 residues is not exposed to the surface of the F1 ATPase. The binding spectrum of the antibodies to the subunit from various species including Vibrio alginolyticus and thermophilic bacterium PS3 indicated possible epitope sequences within the 104 residues. The ternary structure of the beta subunit, in terms of cleavage sites by endopeptidases, was analyzed using the antibodies. A 43-kDa peptide without binding ability to beta 12 and beta 31 appeared upon cleavage by lysyl endopeptidase. The results suggested that lysyl residues from around 70 to 100 from the amino terminus are exposed to the surface of the beta subunit.

Myosin phosphorylation-independent contraction induced by phorbol ester in vascular smooth muscle

In isolated rat aorta, carotid artery, tail artery, rabbit aorta and mesenteric artery, but not in ear artery, 1 microM 12-deoxyphorbol 13-isobutyrate (DPB) induced a sustained contraction. However, DPB increased cytosolic Ca++ concentration ([Ca++]i) only in rat aorta and carotid artery. Similar results were obtained with phorbol 12,13-dibutyrate, although the inactive phorbol ester, 4-alpha-phorbol 12,13-dibutyrate, was ineffective. In rat aorta, DPB-induced contraction was followed by an increase in 20 kDa myosin light chain (MLC) phosphorylation. Both contraction and MLC phosphorylation stimulated by DPB were greater than those due to high K+ for a given increase in [Ca++]i. A Ca++ channel blocker, verapamil, decreased the DPB-induced increments in [Ca++]i and MLC phosphorylation to their respective resting levels, although contraction was inhibited only slightly. In the absence of external Ca++ (with 0.5 mM ethyleneglycol bis(beta-aminoethyl-ether)tetraacetic acid), DPB induced sustained contraction without increasing [Ca++]i or MLC phosphorylation. This contraction was followed by an increase in stiffness and force recovery after a shortening step. These results suggest that the contraction induced by DPB in rat aorta is due to increase in [Ca++]i followed by MLC phosphorylation and Ca++ sensitization of MLC phosphorylation. In the presence of verapamil or in the absence of external Ca++, DPB may increase cross-bridge cycling by activating an unknown mechanism that is not dependent on an increase in MLC phosphorylation.

Receptor agonists induce myosin phosphorylation-dependent and phosphorylation-independent contractions in vascular smooth muscle

In isolated rat aorta, 72.7 mM KCI, 10 microM prostaglandin F2 alpha, 30 nM endothelin-1 and 1 microM norepinephrine increased muscle tension, cytosolic Ca++ concentration ([Ca++]i) and 20 kDa myosin light chain (MLC) phosphorylation. The levels of contractile tension and MLC phosphorylation at a given [Ca++]i were greatest in the presence of endothelin-1 followed by prostaglandin F2 alpha greater than norepinephrine greater than high K+. Verapamil inhibited the high K(+)-induced increments to their respective resting levels. Verapamil also almost completely inhibited the receptor agonist-induced increments in [Ca++]i and MLC phosphorylation, although a part of the contraction was not inhibited. Ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid further decreased [Ca++]i and muscle tension, suggesting that a part of the contraction is regulated by [Ca++]i below a resting level. Receptor agonists induced sustained contraction in the absence of external Ca++ which was not followed by the increase in [Ca++]i or MLC phosphorylation. This contraction was followed by the increments in shortening velocity and stiffness. In the rabbit mesenteric artery permeabilized with Staphylococcus aureus, alpha-toxin, norepinephrine and endothelin-1 shifted the Ca(++)-tension curve to the left in the presence of GTP. From these results, it is suggested that high K(+)-induced sustained contraction of vascular smooth muscle is attributable to an increase in [Ca++]i followed by an increase in MLC phosphorylation. In addition to this fundamental mechanism, receptor agonists increase Ca+ sensitivity of MLC phosphorylation when [Ca++]i is higher than resting level resulting in a greater contraction than that induced by high K+ for a given increase in [Ca++]i.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinicobacteriological study of Pasteurella multocida infection as a zoonosis. (2)--Comparisons of P. multocida separated from patients and their pet dogs and cats]

A total of 17 strains of Pasteurella multocida, of which 13 were isolated from patients treated at Nihon University Itabashi Hospital or Nihon University Surugadai Hospital between April, 1984 and March, 1991 and 4 from 1 dog and 3 cats kept by the patients, were evaluated with respect to their biochemical properties, sensitivity to drugs, and serotype. The isolated strains were all considered to be Pasteurella multocida subsp. multocida because of the agreement of their responses to indole, sorbitol and dulcitol with those of this subspecies, except for 1 sorbitol-negative strain of Pasteurella multocida subsp. septica isolated from 1 patient who had been bitten by a cat. All the isolated strains showed high sensitivities to various drugs. The serotype was capsular type A, which is often observed in cats and dogs, in 7 strains, which consisted of 6 of the 7 strains derived from the airway of the patients and 1 of the 6 strains derived from bit or scratch wound. The remaining strains could not be classified. Five morphological types, namely 1, 3, 3.8, 6, and 8 were observed. In 2 patients, Pasteurella multocida subsp. multocida of the same serotype was also isolated from their cats. One of these patients had intimate contact with the cat including kissing. Our findings suggest that: 1) Pasteurella multocida subsp. multocida has been responsible for most conventional cases of Pasteurella multocida infection. 2) Strains isolated from patients differ in the capsular type according to the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Cheiro-oral syndrome due to lesions in the corona radiata

BACKGROUND AND PURPOSE

We describe three patients with cheiro-oral syndrome caused by a small lesion in the corona radiata confirmed by high-resolution magnetic resonance imaging.

CASE DESCRIPTIONS

Case 1: A 56-year-old hypertensive man who developed hypesthesia and paresthesia in the left perioral area and hand was found to have a small hematoma just lateral to the right internal capsule. Case 2: A 67-year-old man noticed hypesthesia around the left mouth angle and thumb and index finger. Magnetic resonance imaging revealed a lesion in the right corona radiata. Case 3: A 45-year-old hypertensive man developed numbness in his perioral region and left hand that later spread to his shoulder. Magnetic resonance imaging revealed a recent small infarct in the lower lateral aspect of the right corona radiata.

CONCLUSIONS

A small lesion in the corona radiata can cause cheiro-oral syndrome, whose pathogenetic mechanism in such patients may be explained by the somatotopical location or by the differing vulnerability of the neuropils in the corona radiata.

Developmental aspects of a unique glutathione S-transferase subunit Yx in the liver cytosol from rats with hereditary hyperbilirubinuria. Comparison with rat fetal liver transferase subunit Yfetus

The unique glutathione S-transferase (GST) subunit Yx, which is undetectable in normal adult rat liver cytosol, was shown to occur in the liver cytosol of rats with hereditary hyperbilirubinuria (EHB). The Yx subunit is a member of the Alpha-class GST subunits, and is immunologically closely related to the Yc subunit. The Yx subunit has an apparent M(r) of 26,400, different from those of Ya (M(r) 25,800), Yb1 and Yb2 (both M(r) 27,200) and Yc (M(r) 28,400). During postnatal development in livers of EHB rats, the Yx subunit concentration in either sex was highest during the first week post partum and declined rapidly with age. Although the concentration of subunit Yx at 8 weeks of age accounted for about 60% in females and 40% in males of that observed in 1-week-old 'neonatal' male EHB rats, concentrations in females thereafter increased gradually to almost the neonatal level and remained at this high level at least up to 37 weeks of age, whereas the concentration in males did not increase again. Thus the post-pubertal Yx subunit concentration was 2-fold higher in females than in males. In contrast, in normal Sprague-Dawley rat liver, the Yfetus subunit, with the same M(r) as the Yx subunit, had the highest concentration in 10-day-old animals, declined rapidly thereafter, and was not detectable in the post-pubertal period. The Yfetus subunit was also immunoreactive with an antibody against GST YcYc. The analysis of GST subunits by reverse-phase h.p.l.c. revealed that the Yx subunit was eluted at a retention time different from other known subunits, but coincided with that of Yfetus. The N-terminal amino acid sequence of the Yx subunit displayed a high degree of sequence similarity to that of the Yfetus subunit. These data suggest that the Yx subunit in EHB rats may be very similar to, if not identical with, the Yfetus subunit.