[Transvenous monitoring of left atrial and central venous pressure with a double-lumen catheter]

We developed a new method to monitor left atrial pressure in the patients undergoing open heart surgery. The advantages of our method are 1) freedom from complications relating its removal (eg. bleeding) because of its transvenous insertion, and 2) simultaneous monitoring of both right and left atrial pressures by a single catheter. We designed to place the second port of a two-lumen central venous catheter 5 or 7 cm proximal to the tip. The catheter is inserted into the right atrium before surgery and the tip is advanced in the left atrium through the foramen ovale intraoperatively. We used this catheter in 16 infants and children, and found that effective hemodynamic monitoring was obtained without any complications. We recommend this method for the postoperative management of open heart surgery in the pediatric patients.

Studies on the synthesis of nucleotidyl-peptides. II. The preparation of a nucleotidyl-peptide having a 5'-nucleotidyl-(P-O)-serine phosphodiester bond

The preparation of a nucleotidyl-peptide having a thymidine-5'-yl-(P-O)-serine phosphodiester bond, [H-Ala-Ser(pTpT)-Phe-OH](24) is described. After condensation between the phosphorylated peptide component and an oligonucleotide component, all protecting groups could be removed under neutral conditions without beta-elimination of the pTpT from the serine moiety.

Susceptibility of Salmonella typhi and Brucella melitensis to the new fluoroquinolone rufloxacin (MF 934)

The antimicrobial activity of the new fluoroquinolone rufloxacin (MF 934) was evaluated by a standardized agar dilution method against recent clinical isolates of Salmonella typhi (67 strains) and Brucella melitensis (108 isolates). The results were compared with 5 other commercially available or investigational fluoroquinolones. All the isolates of S. typhi were inhibited by 1.0 mg/l of rufloxacin as compared to 4-8 mg/l for B. melitensis. Minimum inhibitory concentrations of rufloxacin against both S. typhi and B. melitensis were 4-16 times higher than those of other fluoroquinolones.

Increase in T cells bearing the gamma/delta receptor associated with lymphoproliferative disease of granular lymphocytes in an infant with intractable diarrhea

A two-year-old infant with intractable diarrhea and lymphoproliferative disease of granular lymphocytes attributed to a persistent cytomegalovirus infection showed an increase in cells bearing the gamma/delta T-cell receptor (TCR), which accounted for approximately 20% of total peripheral blood lymphocytes and 40% of CD3+ T cells. Of the gamma/delta TCR+ cells, two-thirds were double negative (CD4-/CD8-) and the other one-third CD8 positive. The majority of gamma/delta+ cells were delta TCS 1 positive. The predominance of delta TCS 1 positive cells was also confirmed on biopsy of lymphoid tissues from the colon. After improvement of watery diarrhea and malnutrition following three-month hyperalimentation, the number of gamma/delta TCR+ cells decreased. The patient subsequently died of pneumonia at the age of 2 years and 11 months. A possible site-specific role for the gamma/delta TCR+ cells, particularly delta TCS 1+ cells, in the human intestine is discussed.

Effects of beraprost on the transmembrane potentials of guinea-pig ventricular muscles during normoxia and hypoxia-reoxygenation

1. The present study was performed to determine whether beraprost, a new stable analogue of prostacyclin, may exert beneficial effects on the transmembrane action potentials during normoxia and hypoxia-reoxygenation in isolated right ventricular muscles of the guinea-pig. 2. Under normal oxygenation, beraprost (0.01-100 mumol-1) had no effects on the electrophysiological parameters. 3. Hypoxic conditions induced a decrease in action potential duration (APD) without affecting other action potential parameters. Beraprost inhibited this hypoxia-induced decrease in APD. However, beraprost had no effect on the decrease in contractile force induced by hypoxia, whereas it significantly improved the recovery of contractile force after reoxygenation. 4. Pinacidil-induced shortening of APD was not antagonized by beraprost. 5. Hypoxia significantly decreased the myocardial adenosine triphosphate (ATP) level, which was also prevented by beraprost. 6. These results suggested that beraprost may inhibit the hypoxia-induced shortening of APD by some mechanisms which contribute to the maintenance of muscle ATP level.

Effects of nivalenol on hepatic drug-metabolizing activity in rats

Effects of nivalenol (NIV), a trichothecene mycotoxin, on hepatic drug-metabolizing activity and aflatoxin B1 (AFB1) metabolism were investigated in male rats. In rats fed the diets containing 6-12 ppm NIV for 2 or 4 wk, decreases in initial feed uptake, terminal weight gain and organ weights were evident. An increase in cytochrome P-450 activity was observed in the hepatic microsomes, and Western blot analysis revealed a transient increase in P4502B1/2, together with a slight induction of P4501A2. The activity of cytosolic glutathione S-transferase (GST) enzymes was also enhanced in the rats, and Western blot analysis demonstrated an elevation of GST 1-2. The formation of aflatoxin B1-DNA adducts (AFB1-DNA) was increased in experiments using hepatic microsomal preparations from rats fed the NIV diet, whereas supplementation with cytosol prepared from NIV-treated rats reduced the microsomal potential for adduct formation. In in vivo experiments, the AFB1-DNA concentration in NIV-treated rats was lower than that in the controls. These results suggest that activities of cytochrome P-450 and GST enzymes were increased in rats fed NIV for several weeks. Alteration of these phase I and phase 2 enzyme levels resulted in the modulation of AFB1 adduction to DNA in vitro and in vivo.

Recombinant human granulocyte colony-stimulating factor accelerates regeneration after T-2 toxin-induced hemopoietic injury and lessens lethality in mice

The effects of rhG-CSF on T-2-induced leukopenia and lethal toxicity in mice were investigated. First, T-2 was administered by gavage to adult male mice at a dose of 3 mg/kg b.w. daily for 7 days, and rhG-CSF was given i.p. in daily dose of 10 or 30 micrograms/kg b.w./day, beginning on the 2nd day, for 5 days. The peripheral WBC of mice receiving T-2 alone was decreased to one fourth of control counts, and bone marrow (BM) cell counts were also markedly diminished. The administration of rhG-CSF prevented those T-2-induced depressions. Histologically, the delation of the hematopoietic cells from BM and spleen of mice given T-2 was remarkably counteracted by administration of rhG-CSF. In the other experiment, rhG-CSF was injected i.p. for 5 days beginning on the next day of the 7-day T-2 administration. The recovery of WBC and BM cell counts was hastened by rhG-CSF reaching the control level in 6 days, and differential leukocyte analysis revealed an increase of neutrophils. Furthermore, simultaneous administration of rhG-CSF depressed the T-2-induced lethal toxicity, dose-dependently. The results revealed that rhG-CSF possesses a potent ability to protect T-2-induced leukopenia and lethality in mice, and it could be as an antidote against T-2 and related trichothecene-induced acute intoxication.

A case of drug-induced ductopenia resulting in fatal biliary cirrhosis

A 50-year-old woman suffered from a diffuse skin rash, high fever and jaundice immediately after a second injection of glutathion and Stronger Neo-minophagen C which contains glycyrrhizin. Liver biopsy performed 11 months after the onset showed mild spotty hepatocyte necrosis, marked cholestasis in parenchyma, and some lymphocyte infiltration in the portal area. Interlobular bile ducts had undergone vacuolar degeneration or were absent in some portal tracts. In her hospital course, unremitting jaundice persisted and biliary cirrhosis developed with signs of portal hypertension; she died from liver failure 26 months after the onset. A liver specimen at her death revealed that most of the interlobular bile ducts had vanished. Based on the clinical course and pathology, drug-induced ductopenia, possibly due to an adverse reaction to glycyrrhizin, is the most likely diagnosis. While drug-related biliary cirrhosis is rarely fatal, this case presented an unusually rapid course of fatal biliary cirrhosis.

Elucidation of a conserved RNA stem-loop structure in the packaging signal of human immunodeficiency virus type 1

A region of human immunodeficiency virus type 1 (HIV-1) genomic RNA known to interact with the viral nucleocapsid protein is one of the crucial components for retroviral genomic RNA packaging. We have investigated the secondary structure for this RNA packaging signal of HIV-1 using RNA mapping techniques and extensive computer analyses. Our results suggest that the RNA sequence containing the packaging signal conforms to a stable stem-loop structure and that a portion of this structure is conserved among twenty independent HIV-1 isolates. The heterogeneity of the RNA packaging sequence was not correlated with the amino acid sequence variability of the viral nucleocapsid protein. These findings have critical implication in understanding the viral maturation process.

Oxidoreductive regulation of nuclear factor kappa B. Involvement of a cellular reducing catalyst thioredoxin

We have investigated an oxidoreductive regulatory pathway for the DNA binding activity of a pleiotropic cellular transcription factor, nuclear factor kappa B (NF kappa B), has been investigated by using NF kappa B prepared from the nucleus and the cytosol of the primary human T lymphocytes. We show that a cellular reducing catalyst thioredoxin (Trx) plays a major role in activation of the DNA binding of NF kappa B in vitro and stimulation of transcription from the NF kappa B-dependent gene expression. We demonstrate evidence suggesting that redox regulation of NF kappa B by Trx might be exerted at a step after dissociation of the inhibitory molecule I kappa B, a cytosolic-anchoring protein for NF kappa B. To examine the effect of Trx in intact cells, we performed transient assay with a chloramphenicol acetyltransferase-expressing plasmid under the control of human immunodeficiency virus (HIV) long terminal repeat and an effector plasmid expressing human Trx. The promoter activity from HIV long terminal repeat was greatly augmented by co-transfecting the Trx-expressing plasmid, whose effect was dependent on the NF kappa B-binding sites. These findings have suggested that cysteine residue(s) of NF kappa B might be involved in the DNA-recognition by NF kappa B and that the redox control mechanism mediated by Trx might have a regulatory role in the NF kappa B-mediated gene expression. These results may also provide a clue to understanding of the molecular process of AIDS pathogenesis and its possible biochemical intervention.

Metabolism and distribution in the rat of peak E substance, a constituent in L-tryptophan product implicated in eosinophilia-myalgia syndrome

Peak E substance, 1,1'-ethylidenebis[tryptophan], a contaminant found in L-tryptophan tablets, has been suggested as a causative agent for eosinophilia-myalgia syndrome (EMS). Peak E substance (50 mg/kg) was administered perorally to Wistar rats to determine its metabolism and distribution. A purification procedure using Bond Elut C8 cartridges followed by HPLC was developed for the determination of peak E substance. The plasma concentration of peak E substance was 136 ng/ml at 1 h, and urinary excretion was 717 ng at 5 h and 10342 ng for 5-24 h, showing slow excretion of peak E substance into urine. The amount of peak E substance in the contents of the large intestine at 5 h, however, was 3136 micrograms, much greater than urinary excretion for 24 h, indicating considerable transfer of peak E substance to large intestine without decomposition by gastric fluid in the stomach. We have detected for the first time not only the occurrence of peak E substance in plasma and urine, but also 1-methyl-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) in blood and organs of rats treated with peak E substance, thereby suggesting MTCA as one of the the metabolites of peak E substance. The amount of MTCA in the contents of the large intestine as well as in urine of rats treated with peak E substance was significantly greater than in L-tryptophan-treated rats (50 mg/kg p.o.), demonstrating that MTCA was more readily produced from peak E substance than from L-tryptophan. Finally, we propose acetaldehyde-induced production of MTCA from peak E substance.

Comparative activity of the new fluoroquinolone rufloxacin (MF 934) against clinical isolates of gram-negative and gram-positive bacteria

The antibacterial activity of the new fluoroquinolone rufloxacin (MF 934) was evaluated against 1095 clinical isolates and compared with that of other quinolones and various commonly used antibiotics. Rufloxacin was highly effective against members of the Enterobacteriaceae, inhibiting 98% of the isolates at a concentration of 1 mg/l. Ninety-two percent of Aeromonas hydrophila and 65% Acinetobacter strains tested were inhibited by 1 mg/l of rufloxacin, whereas 98% of methicillin-susceptible and 87% of methicillin-resistant Staphylococcus aureus strains and 76% of coagulase-negative staphylococci strains required 4 mg/l for growth inhibition. The MIC values of rufloxacin for most bacteria were 4-16 times higher than those of ciprofloxacin and norfloxacin. Rufloxacin had little activity against xanthomonads, pseudomonads and enterococci. Approximately 95-96% of isolates of Pseudomonas aeruginosa were inhibited by 2 mg/l of ciprofloxacin and norfloxacin as compared to 29% inhibited by rufloxacin at this concentration.

Comparative antibacterial activity of the aminothiazolyl cephalosporin RU 29,246

A total of 1,007 clinical isolates from a tertiary care center were tested against RU 29,246, ampicillin, cephalothin, cefoxitin, ceftazidime, Augmentin, oxacillin, piperacillin, gentamicin, amikacin and vancomycin. Bacteria tested consisted of 479 strains of Enterobacteriaceae, 64 pseudomonads, 18 Xanthomonas, 42 other gram-negative bacilli, 56 enterococci and 348 isolates of staphylococci. RU 29,246 showed excellent in vitro activity inhibiting > 90% of Escherichia coli, Klebsiella pneumoniae, K. oxytoca, Enterobacter, Proteus mirabilis, Providencia, Morganella, Salmonella, Shigella, Aeromonas hydrophila, and methicillin-susceptible Staphylococcus aureus at an MIC of 0.5-1.0 mg/l. Seventy-seven percent coagulase-negative staphylococci had an MIC of 1.0-4.0 mg/l. All strains of Pseudomonas aeruginosa and X. maltophilia were resistant to RU 29,246. Fifty-six percent of the enterococcal isolates were inhibited by 1.0-16.0 mg/l of RU 29,246.

Trans-septal left atrial catheterisation

A newly designed 4 FG double-lumen catheter with the second port located either 5 or 7 cm proximal to the tip was tested in five children undergoing open heart surgery. The catheter was inserted percutaneously and initially positioned in the superior vena cava, right atrium or inferior vena cava. During cardiopulmonary bypass, the tip of the catheter was repositioned manually in the left atrium across the interatrial septum. In all patients, left atrial pressure was monitored successfully while central venous pressure was monitored with the second port positioned in the superior vena cava. Removal of the catheter from the left atrium was easily performed and caused no problems.

Incidence of bacterial respiratory pathogens and their susceptibility to common antibacterial agents

Although most respiratory tract infections are caused by viruses, bacterial pathogens are responsible for higher morbidity and mortality. Because virtually nothing is known about the etiology of bacterial respiratory pathogens in Saudi Arabia, this study examined the incidence of these organisms in 5426 patients over a 1-year period. Of the bacterial pathogens isolated from 904 patients, the most common organism was Hemophilus influenzae (31%), followed by pneumococci (22%), Pseudomonas aeruginosa (16%), and others (31%). Because the first two organisms accounted for more than 50% of isolates, their susceptibility to commonly used antibiotics was also reviewed. The results are presented here.

In vitro activity of cefdinir (FK 482, PD 134393, CI-983): a new orally active cephalosporin

Cefdinir is a new orally active cephalosporin which is undergoing in vitro and in vivo evaluations. Using the standard agar dilution method we compared the in vitro activity of this drug with other beta-lactam antibiotics against clinical isolates or Enterobacteriaceae (625 strains), Pseudomonas aeruginosa (68 strains), Xanthomonas maltophilia (36 strains), Acinetobacter (52 strains), Aeromonas hydrophilia (47 strains), staphylococci (364 strains) and enterococci (50 strains). Against most members of Enterobacteriaceae, Acinetobacter and A. hydrophilia, cefdinir showed excellent activity, inhibiting 94% of these isolates at < or = 32 micrograms/ml. Like other oral drugs of its class, it had little activity against P. aeruginosa and X. maltophilia. All the 120 isolates of methicillin-susceptible Staphylococcus aureus were inhibited by < 1.0 microgram/ml of cefdinir whereas 80% of methicillin-resistant S. aureus had a minimum inhibitory concentration of > 32 micrograms/ml. Of the 50 isolates of enterococci tested, 94% were inhibited by < or = 16.0 micrograms/ml of cefdinir. Against Enterobacteriaceae, its activity was superior to any oral drug tested. With the exception of vancomycin, the in vitro activity of cefdinir was superior or comparable to other antibiotics tested against methicillin-susceptible S. aureus, coagulase-negative staphylococci and enterococci.

CI-990 (PD 131112): A new quinolone prodrug

In vitro susceptibility of 1021 strains of recent clinical isolates was determined against the new fluoroquinolone CI-990 (PD 131112) and compared with CI-960, ciprofloxacin, fleroxacin, lomefloxacin, norfloxacin, perfloxacin, sparfloxacin, and temafloxacin. The minimum inhibitory concentrations (MIC) of CI-990 in mg/L required for >90% isolates were 0.03-0.5 for members of Enterobacteriaceae, 0.12-2.0 for Pseudomonas aeruginosa, 0.03-1.0 for Aeromonas hydrophilia, 1.0-2.0 for Acinetobacter calcoaceticus, 0.5-2.0 for Brucella melitensis, 0.06-1.0 for staphylococci, and 1.0-2.0 for enterococci. Its antibacterial activity was comparable or superior to other fluroquinolones tested against most gram-negative and gram-positive bacteria, including enterococci.

Susceptibility of Brucella melitensis to the new fluoroquinolone PD 131628: comparison with other drugs

The antibacterial activity of PD 131628 was determined by the broth dilution method against 105 clinical isolates of Brucella melitensis. Fifty-two and ninety-nine percent of the isolates were inhibited by 0.06 and 0.12 microgram/ml of this quinolone, respectively. One strain which was resistant to 8 other fluoroquinolones, with a minimum inhibitory concentration (MIC) of > 4.0 micrograms/ml, did not show cross-resistance and had an MIC of 2.0 micrograms/ml. Of the 9 fluoroquinolones tested, PD 131628 was most inhibitory followed by CI-960. All the strains were susceptible to conventional drugs like gentamicin, rifampicin, tetracycline and trimethoprim-sulfamethoxazole, with MICs ranging between 0.12 and 1.0 microgram/ml. PD 131628 did not exhibit in vitro synergy with any of the conventional drugs.

Reaction of alpha-tocopherol with alkyl and alkylperoxyl radicals of methyl linoleate

alpha-Tocopherol was reacted with alkyl and alkylperoxyl radicals at 37 degrees C in bulk phase. The lipid-free radicals were generated by the reaction of methyl linoleate with the free radical initiator, 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN) under air-insufficient conditions. The products were isolated by high-performance liquid chromatography. Their structures were identified as 2-(alpha-tocopheroxy)-2,4- dimethylvaleronitrile (1), a mixture of methyl 9-(8a-peroxy-alpha-tocppherone)-10(E),12(Z)-octadecadienoate and methyl 13-(8a-peroxy-alpha-tocopherone)-9(Z),11(E)-octadecadienoate (2), methyl 9-(alpha-tocopheroxy)-10(E),12(Z)-octadecadienoate (3a), methyl 13-(alpha-tocopheroxy)-9(Z),12(E)-octadecadienoate (3b), alpha-tocopherol spirodiene dimer (4) and alpha-tocopherol trimer (5). When methyl linoleate containing alpha-tocopherol was oxidized with AMVN under air-sufficient conditions, the main products were 8a-alkylperoxy-alpha-tocopherones (2). In addition to these compounds, 6-O-alkyl-alpha-tocopherols (1, 3a and 3b) were formed when the reaction was carried out under air-insufficient conditions. The results indicate that alpha-tocopherol can react with both alkyl and alkylperoxyl radicals during the autoxidation of polyunsaturated lipids.

Acetaldehyde-induced formation of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid in rats

1-Methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) is one of the metabolites of peak E substance, which, based on epidemiological studies, has been thought to be a possible causative agent of the tryptophan-induced eosinophilia-myalgia syndrome. Acute ethanol and L-tryptophan administration in rats pretreated with cyanamide resulted in the formation of MTCA. Concentrations of MTCA were estimated at 27 ng/g in blood and 33 ng/g in kidneys. Chronic treatment with a liquid diet containing ethanol as 36% of the total calories for 6 weeks increased these levels. MTCA was barely observed in rats that had received acute or chronic ethanol in the absence of cyanamide, or in the cyanamide-tryptophan controls. Cyanamide facilitation of ethanol-dependent MTCA biosynthesis may be due to a potentiation of the blood level of acetaldehyde derived from ethanol. The blood acetaldehyde level in rats that had been acutely treated with cyanamide, ethanol and L-tryptophan was 348 microM, and averaged 503 microM in rats that received the same treatment after chronic consumption of ethanol. In contrast to the above findings, L-tryptophan intake promoted the formation of 1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (TCCA) in rats. This is the first report of MTCA in mammalian tissue during tryptophan and ethanol metabolism.

Secondary spontaneous pneumothorax

To assess the clinical manifestations and therapy of secondary spontaneous pneumothorax (SSP), 123 episodes of SSP in 67 patients were retrospectively reviewed and were compared with 254 episodes of primary spontaneous pneumothorax in 130 patients. The major underlying lung diseases associated with SSP were emphysema (22 patients) and tuberculosis (21 patients). The average age of patients with SSP was 66.8 years, and the most common symptom was dyspnea. The average arterial oxygen tension at onset of SSP was 61.1 +/- 12.1 mm Hg (mean +/- standard deviation), which was lower than that of patients with primary spontaneous pneumothorax (p < 0.01). The recurrence rate of open thoracotomy with pleural abrasion was 12.5% (3 of 24 episodes), which was not lower than that of thoracostomy tube drainage with chemical pleurodesis using tetracycline (recurrence rate, 18.8%) (p > 0.5). We concluded that considering the high age of the patients, the presence of underlying lung diseases, and the increased operative risk, thoracostomy tube drainage rather than open thoracotomy was preferred as the first choice of therapy for SSP.

Genetic polymorphism of alcohol and aldehyde dehydrogenase and the effects on alcohol metabolism

Influence of genetic polymorphism at the alcohol dehydrogenase2 (ADH2) and aldehyde dehydrogenase2 (ALDH2) loci on ethanol elimination and blood acetaldehyde level was studied in healthy subjects. Polymorphic regions of the ADH2 and ALDH2 genes were amplified for genomic DNA by using the technique of polymerase chain reaction. The ADH2 genotype was determined by digestion with the restriction enzyme MaeIII and the ALDH2 genotype was defined by hybridization with sequence specific oligonucleotide probes. Both loci were typed for unrelated 58 individuals by using the above methods. The gene frequencies of each locus were estimated as follows; 0.31 and 0.69 for ADH2*1 and ADH2*2, respectively, and 0.73 and 0.27 for ALDH2*1 and ALDH2*2, respectively. These values were consistent with the Hardy-Weinberg equilibrium. Pedigree analysis of 6 families with 46 subjects on both loci confirmed Mendelian inheritance. In order to investigate differences in ethanol elimination among ADH2 and ALDH2 genotype groups, 0.4 g/kg body weight of ethanol was administered to 93 subjects whose genotypes of both loci were determined by the above methods and blood ethanol and acetaldehyde levels were measured. None of the subjects homozygous for the ALDH2*1 allele showed facial flushing and any increase in blood acetaldehyde level. All the homozygotes and heterozygotes with the ALDH2*2 allele exhibited facial flushing, and the former showed a marked increase in blood acetaldehyde level and the latter did a mild increase. On the other hand, the influence of the ADH2 genotype on blood acetaldehyde level was not significant. The values of Widmark's beta 60 (mg/ml/hr) and ethanol elimination rate (mg/kg/hr) showed significant differences among the three groups of the ALDH2 genotypes in each group of the three ADH2 genotypes, and in decreasing order of both the values were ALDH 2*1/*1, ALDH2*1/*2, ALDH2*/*2, However, there were no significant differences in the values among the ADH2 genotypes.