Floxuridine-induced sclerosing cholangitis: an ischemic cholangiopathy?

A 43-year-old man underwent abdominoperineal resection of a rectal adenocarcinoma, and left hepatic lobectomy for a single metastasis. He then received hepatic artery infusions of floxuridine. The tumor did not recur, but sclerosing cholangitis and liver failure developed which necessitated orthotopic liver transplantation. In the hilus of the native liver, obstructive arteriopathy and portal venopathy were found. These lesions probably had been caused by drug-induced intravascular thrombosis. Thus, the sclerosing cholangitis that develops in many patients after floxuridine infusion may be ischemic rather than toxic. The patient described here is well, 14 months after orthotopic liver transplantation. Therefore, in some cases of floxuridine-induced cholangitis, liver transplantation appears to be indicated despite a history of metastasizing carcinoma.

Effect of inhibition of prostaglandin synthesis on epinephrine-induced gastroduodenal electromechanical changes in humans

We conducted a double-blind randomized study to investigate the role of endogenous prostaglandins in epinephrine-induced changes in human gastric electromechanical activity. Intravenous administration of a pharmacologic dosage of epinephrine (222 ng/kg per min) caused gastric dysrhythmia in 8 of 12 healthy subjects. After indomethacin treatment, the incidence of epinephrine-induced gastric dysrhythmia was reduced to 4 of 12 healthy subjects, which is similar to the incidence of gastric dysrhythmia noted in the placebo group. The difference, however, was not statistically significant (P = 0.2). Epinephrine also substantially inhibited both the amplitude and the frequency of antral contractions. Indomethacin treatment partially reversed the reduction in the amplitude but not the frequency of antral contractions. These results suggest that endogenous prostaglandins may, in part, regulate the amplitude of human antral contractions; however, the role of prostaglandins in epinephrine-induced gastric dysrhythmia in humans remains uncertain.

Korean version of the Geriatric Social Readjustment Questionnaire: cross-cultural comparison between Koreans and Americans in the perception of life events

The purpose of this study was to construct a Korean version of the Geriatric Social Readjustment Questionnaire (K-GSRQ), to investigate its applicability to the elderly and to compare cross-cultural differences in the perception of the life events between Koreans and Americans. The K-GSRQ consists of 33 items. Most of the life events considered as crucial in old age were similar in ranking in comparison between Koreans and Americans. Some differences in ranking can be attributed to the differences in Socio-cultural backgrounds. The K-GSRQ was applied to controls, neurotic cases and cases with physical illnesses. The result suggest that the Korean version of the Geriatric Social Readjustment Questionnaire is applicable for the study of the health status of the elderly in Korea.

Idiopathic cyclic nausea and vomiting--a disorder of gastrointestinal motility?

Eight patients (five men and three women) with previously unexplained recurrent cyclic episodes of nausea and vomiting are described. In these patients, the symptoms developed a mean of once every 3.2 months and persisted a mean of 3.5 days. None of the patients had an identifiable cause of their symptoms on conventional diagnostic tests. A detailed investigation of the gastrointestinal motility during an asymptomatic period revealed abnormal findings in all eight patients. Gastric hypomotility was substantiated in five patients, small bowel dysmotility in six, delayed gastric emptying in two, and gastric dysrhythmia in two. The data demonstrate that abnormal gastrointestinal motility occurs during an asymptomatic state in patients with cyclic episodes of nausea and vomiting. Because all patients with this syndrome had abnormal gastrointestinal motility but normal results of other gastrointestinal studies, idiopathic cyclic nausea and vomiting may be related to altered gastrointestinal motility.

Deterioration of membrane morphology, phospholipids, and cytoskeletal protein in rat erythrocytes exposed to tert-butyl hydroperoxide: protection by exogenous glutathione fails in selenium deficiency

Here we report scanning electron microscopy, phospholipid and fatty acid composition and cytoskeleton proteins of erythrocytes from Se-adequate and Se-deficient rats, showing protection by glutathione (GSH) against tert-butyl hydroperoxide (t-BuOOH)-induced hemolysis of erythrocytes from Se-adequate, but not from Se-deficient rats. Without exogenous GSH, erythrocytes incubated with t-BuOOH exhibited remarkable deterioration of cell membranes with diminished membrane phosphatidyl-ethanolamine, -serine, and -inositol and selective loss of a cytoskeletal protein, ankyrin 2-1. Without exogenous GSH these changes occurred in erythrocytes from both Se-deficient and Se-adequate rats. Dietary Se, through provision of glutathione peroxidase (GSH-Px) in erythrocytes as a probable scavenger of t-BuOOH, protects against hemolysis when GSH is available.

Evidence for a delta-class opioid receptor on cells of the immune system

Opioid receptors have been reported to be present on cells of the immune system. Both opioid receptor-ligand interactions which are reversible by naloxone (classical) and those interactions which are irreversible by naloxone (nonclassical) appear to alter various immunologic parameters through the ligand-receptor interactions. In an effort to characterize opioid receptors (which operate with classical interactions) on cells of the immune system, we employed the delta-class opioid receptor-specific ligand, cis-(+)-3-methylfentanylisothiocyanate (SUPERFIT). We herein report the specific labeling of a protein with a molecular weight of 70,000 Da under reducing conditions (58,000 Da under nonreducing conditions) from both B and T cell-enriched murine splenocytes and peripheral blood lymphocytes. Similar results are demonstrated by human peripheral blood lymphocytes and plastic-adherent (monocyte-enriched) leukocytes.

tert-butyl hydroperoxide-induced hemolysis of alpha-tocopherol-decreased erythrocytes from selenium-deficient and selenium-adequate rats

The protective function of alpha-tocopherol, glutathione (GSH), and glutathione peroxidase (GSH-Px) from tert-butyl hydroperoxide (t-BuOOH)-induced hemolysis was studied with the erythrocytes from male Wistar rats fed selenium (Se)-adequate or -deficient diet for 3 months. By the preincubation with a water-soluble radical initiator, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), at 10 mM for 6 h at 37 degrees C, alpha-tocopherol levels of the erythrocytes were decreased to 40% of the original level, that is, to the level insufficient for supporting the normal functions of the erythrocytes. With the Se-deficient cells, the hemolysis proceeded rapidly irrespective of the presence or absence of GSH in the incubation medium, and irrespective of the presence or absence of AAPH in the preincubation medium. Contrarily, GSH suppressed the hemolysis of Se-adequate cells which were preincubated with and without AAPH. These results are consistent with the notion that Se serves as the prime, important defense mechanism in the t-BuOOH-induced hemolysis through the activity of GSH-Px. Either alpha-tocopherol or GSH by itself, or both by themselves, may not play so significant a role as Se does in suppressing the hemolysis.

Cardiac amyloidosis diagnosed by endomyocardial biopsy

A 56-year-old male patient who had a history of syncopal attack was diagnosed as having cardiac amyloidosis. His ECG finding showed a pattern of inferior and anteroseptal wall infarction with Wenckebach AV block.

Echocardiographic examination revealed that the LV posterior wall and interventricular septum were markedly thickened with granular sparkling.

We demonstrated the amyloid deposit in the myocardium by endomyocardial biopsy.

Pathology showed a green white birefringence by polarizing illumination and amyloid fibril in electron microscopic study.

Effect of gastric dysrhythmias on postcibal motor activity of the stomach

The effect of electrical dysrhythmias on the mechanical activity of the fed stomach was investigated in 5 conscious dogs implanted with Ag-AgCl electrodes and strain gauge force transducers. Each dog was fed 1 can of ALPO and electromechanical activities of the stomach were recorded for the next 120 min. The results show that intraarterial boluses of met-enkephalin (75 micrograms/kg), PGE2 (36 micrograms/kg), and epinephrine (36 micrograms/kg) induced episodes of antral dysrhythmias whereas saline (1 cc) did not. The postcibal antral motility index for the test period was not altered following saline injection, but it was reduced by 61%, 70%, and 81% following the administration of met-enkephalin, epinephrine, and PGE2, respectively (p less than 0.01 vs. baseline period). During periods of normal electrical rhythm, PGE2 and epinephrine significantly reduced the antral motility index (2.07 +/- 0.93 and 3.24 +/- 0.79, respectively) vs. saline (7.92 +/- 0.44) (p less than 0.05 for both drugs) whereas met-enkephalin (4.98 +/- 0.56) did not. In contrast, during episodes of dysrhythmia, met-enkephalin significantly depressed antral motility (1.70 +/- 0.74) (p less than 0.05 vs. periods with normal electrical rhythm) whereas neither epinephrine nor PGE2 caused a further reduction in antral motility from what was seen during periods of normal electrical rhythm (1.84 +/- 0.72 and 1.34 +/- 0.37, respectively). We thus conclude that intraarterial administration of met-enkephalin, PGE2, or epinephrine induce gastric dysrhythmias postcibally and depress antral contractile activity. The relaxatory effect of met-enkephalin on antral contractions is primarily due to its dysrhythmic effect whereas PGE2 and epinephrine inhibit antral motility even when the electrical rhythm is undisturbed.

Induction of Symbiotically Defective Auxotrophic Mutants of Rhizobium fredii HH303 by Transposon Mutagenesis

Symbiotically defective auxotrophic mutants were isolated by transposon Tn 5 mutagenesis of Rhizobium fredii HH303, a fast-growing microsymbiont of North American commercial soybean cultivars such as Glycine max cv. Williams. Three different Tn 5 -carrying suicide vectors, pBLK1-2, pSUP1011, and pGS9, were used for mutagenesis with transposition frequencies of 4 × 10 −5 , 3 × 10 −6 , and 1 × 10 −6 , respectively, while the frequency of background mutation resistant to 500 μg of kanamycin per ml was 1 × 10 −8 . From 2,600 Tn 5 -induced mutants, 14 auxotrophic mutants were isolated and classified in seven groups including adenosine (four), aspartate (two), cysteine or methionine (two), isoleucine and valine (two), nicotinic acid (one), pantothenic acid (one), and uracil (two). All the auxotrophs induced nodulation on soybean, but the symbiotic effectiveness of each mutant was different. Three auxotrophs (two cysteine or methionine and one pantothenic acid) formed effective nodules similar to those of the wild type. Three auxotrophs (one nicotinic acid and two aspartate) produced mature nodules like those of the wild type, but the nodules lacked the characteristic pink color inside and were unable to fix nitrogen. Four auxotrophs (two adenosine and two uracil) induced pseudonodules unable to fix nitrogen. The other four auxotrophs repeatedly induced both effective and ineffective nodules, but bacteroids isolated from the effective nodules were prototrophic revertants. The symbiotic phenotype and the degree of effectiveness of the auxotrophic mutants varied with the type of mutation.

Noninvasive evaluation of left ventricular diastolic function in patients with angina pectoris--pulsed Doppler echocardiographic technique

To assess the disturbed left ventricular diastolic filling by pulsed Doppler echocardiography in patients with angina pectoris who have normal systolic function, 55 subjects (33 angina patients with, 22 control subjects without significant (⩾75%) coronary artery narrowing) underwent pulsed Doppler echocardiography examination one day before coronary arteriography. From analysis of the transmitral flow velocity curve, diastolic time intervals, peak early and late atrial flow velocities, the ratio of early to atrial peak flow velocity, and deceleration slope after peak early flow velocity were measured. The angina group had a significantly higher peak atrial flow velocity (50.1 ± 10.0 cm/sec vs. 43.7 ± 9.0, p<0.05) and a lower ratio of early to atrial peak flow velocity (0.91 ± 0.24 vs. 1.17 ± 0.30, p<0.005), but peak early flow velocity, deceleration slope, and diastolic time intervals were similar in both groups. Therefore, the pulsed Doppler technique using the transmitral flow velocity curve is thought to be useful in the noninvasive evaluation of diastolic function even in patients with angina pectoris who have normal systolic function and no left ventricular hypertrophy.

Studies on mikamycin B lactonase. V. Metabolic control in mikamycin B fermentation

In mikamycin B fermentation, some procedures were examined to remove the participation of mikamycin B lactonase, which reduces mikamycin B titers. Addition of enzyme inhibitors and control of pH resulted in the elimination of the enzyme activity, and in the stimulation of antibiotic production.

Isolation and identification of beta-nitrostyrene from smoked chicken

Extraction and identification of beta-nitrostyrene from smoked chicken is described. Commercially obtained smoked chicken was homogenised and extracted with chloroform-methanol (2:1). The extracts were fractioned by silicic acid column chromatography. The purified extract using thin-layer chromatography was identified by a colour reaction (this qualitative method for some nitrated compounds is developed this time), high pressure liquid chromatography and gas chromatography/mass spectrometry. The concentration of beta-nitrostyrene in the smoked chicken was 94 ppb. The average recovery of added beta-nitrostyrene was 107%. However, the toxicity of this material was not tested in the present paper.

Radiofrequency hyperthermia for malignant brain tumors: preliminary results of clinical trials

Local hyperthermia by 13.56-MHz radiofrequency (RF) capacitive heating was evaluated in 16 patients with malignant brain tumors. Intracranial heating during operation was performed in 4 patients. RF applicators with a cooling system were placed on the cerebral convexity and medial brain surface with the tumor between them. RF power was controlled to maintain the brain temperatures under 40 degrees C. Under this condition, the highest temperature of each tumor varied from 44 to 49 degrees C. After heating for about 60 minutes, 2 tumors showed regression on computed tomographic (CT) scans. Extracranial heating was performed in 12 patients with cerebral glioblastoma. RF applicators were placed on the lateral sides of the scalp and applied to diametrically opposite sides of the tumor. To avoid the influence of the skull on RF conduction, we performed a bilateral craniectomy slightly larger than the applicator at the initial operation. Heating was performed for approximately 60 minutes at each session and was repeated twice a week for a total of 4 to 10 times in combination with radiation and ACNU chemotherapy. No anesthetic agent was used during heating. Brain temperatures were maintained under 42 degrees C. The scalp under the applicators remained at 28-35 degrees C during heating, and no heat injury of the scalp was observed after repeated heating. The highest temperatures of the tumor or cavity after tumor removal were 45-46 degrees C in 3 cases, 43-44 degrees C in 3 cases, 42-43 degrees C in 4 cases, and 40-41 degrees C in 2 cases, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Meal reduces sensitivity of the stomach to pharmacologically induced dysrhythmia

The aim of this study was to determine whether food ingestion causes a change in the susceptibility of the stomach to dysrhythmia or in the characteristics of gastric dysrhythmia. The susceptibility of the stomach to develop dysrhythmia was measured by determining the median effective dose of four different drugs known to produce gastric dysrhythmia. These drugs were epinephrine, PGE2, met-enkephalin, and glucagon. The median effective dose for inducing gastric dysrhythmia was measured in four healthy conscious dogs by Dixon's up-and-down method during fasting and after feeding. The median effective dose of epinephrine, PGE2, met-enkephalin, and glucagon were higher after feeding (16.6, 16.6, 35.1, greater than 221 micrograms/kg, respectively) than during fasting (1.7, 5.2, 11.1, 61.0 micrograms/kg, respectively). The results indicate that feeding renders the stomach less susceptible to pharmacologically induced dysrhythmia. However, characteristics of gastric dysrhythmias, such as site of origin and direction of propagation, were similar whether they occurred during fasting or after feeding.

Specific stimulation of simian virus 40 late transcription in vitro by a cellular factor binding the simian virus 40 21-base-pair repeat promoter element

We have identified a cellular transcription factor from uninfected HeLa cells that stimulates the simian virus 40 (SV40) late mode of transcription and specifically binds the SV40 21-base-pair repeat promoter element. In particular, the late SV40 transcription factor (LSF) stimulates transcription at initiation sites L325 and L264 of the SV40 late promoter, which are the major transcription sites utilized after DNA replication during the SV40 lytic cycle. In addition, LSF appears to stimulate transcription to a lesser extent from the late-early initiation site of the early promoter. LSF binds specifically to the 21-base-pair repeats of the SV40 promoters, forming specific protein-DNA complexes, which migrate more rapidly through nondenaturing polyacrylamide gels than that formed by the previously identified transcription factor Sp1. Thus, LSF is distinguishable from Sp1 in both its transcriptional and DNA-binding properties. These findings suggest a potential role of LSF in the early to late transcriptional switch during a SV40 lytic infection.

The nifA gene of Rhizobium meliloti is oxygen regulated

Experiments using plasmid-borne gene fusions and direct RNA measurements have revealed that expression from the nifA gene is induced in Rhizobium meliloti when the external oxygen concentration is reduced to microaerobic levels. Induction occurs in the absence of alfalfa and in the presence of fixed nitrogen and does not require ntrC. The production of functional nifA gene product (NifA) can be demonstrated by its ability to activate the nitrogenase promoter P1. Aerobic induction of nifA can also occur during nitrogen starvation at low pH, but in this case induction is dependent on ntrC and does not lead to P1 activation. The data indicate that reduced oxygen tension is potentially a major trigger for symbiotic activation of nitrogen fixation in Rhizobium species.

Role of the hinge protein in the electron transfer between cardiac cytochrome c1 and c. Equilibrium constants and kinetic probes

A role of the hinge protein is studied in the electron transfer reaction between cytochromes c1 and c, using highly purified "one-band" cytochrome c1 and "two-band" cytochrome c1. The results show that the hinge protein (Hp), which is essential for a stable ionic strength-sensitive c1-Hp-c complex, seems to play a certain role in electron transfer between cytochromes c1 and c; Keq for electron transfer reaction between cytochromes c1 and c in the presence of the hinge protein is found to be about 40% higher than that in the absence of the hinge protein at low ionic strength, but no difference exists at high ionic strength. We propose a hypothesis that the hinge protein may function as regulator for the electron transfer reaction between cytochromes c1 and c, and this may be at least one of the roles of the hinge protein in mitochondria.

Potential anti-AIDS drugs. 2',3'-Dideoxycytidine analogues

5-Substituted 2',3'-dideoxycytidine analogues have been synthesized and evaluated in vitro for their capabilities to protect T4+ lymphocytes from the cytopathic effects of the HTLV-III/LAV (HIV) virus, the causative agent of acquired immunodeficiency syndrome (AIDS). These analogues were designed to be more lipophilic than 2',3'-dideoxycytidine (ddC) in order to enhance central nervous system penetration. Earlier reports had shown that ddC is a potent protective agent. When ddC is substituted at the 5-position with either methyl or bromo substituents, activity is completely abolished. However, when the substitution is fluoro (5-F-ddC), both activity and potency are retained. 2',3'-Dideoxy-5-azacytidine is also protective but more toxic than ddC or 5-F-ddC. In a different approach, an attempt was made to utilize ddCMP, ddTMP, and ddAMP as preformed nucleotides in order to circumvent the generally low level of phosphorylation achieved with dideoxynucleosides which function as relatively poor substrates for the cellular kinases. Only ddAMP is as active as its nucleoside precursor. Because ddAMP is not more active than ddA at low concentrations, it is possible that the active agent is ddA which is generated from ddAMP prior to cell entry.

Preparation and properties of cardiac cytochrome c1

A method for the large-scale isolation of beef heart mitochondrial cytochrome c1 in high purity was developed. This method gave higher yield of "one-band" cytochrome c1 than previously reported [Kim, C. H., & King, T. E. (1981) Biochem. Biophys. Res. Commun. 102, 607-614]. In addition, the present method was effective in the preparation of "two-band" cytochrome c1 which was used to prepare the hinge protein according to the principle of sequential resolution [Kim, C. H., & King, T. E. (1983) J. Biol. Chem. 258, 13543-13551]. The isolation of one-band and two-band cytochrome c1 by this procedure could be completed within 3 or 4 days starting with succinate-cytochrome c reductase. One-band cytochrome c1 showed a molecular weight of 44,000 by sedimentation equilibrium and 29,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The disparities in these data from the actual value of 27,924 by amino acid sequence analysis, as previously reported [Wakabayashi, S., Matsubara, H., Kim, C. H., & King, T. E. (1982) J. Biol. Chem. 257, 9335-9344], are most probably due to the formation of detergent or detergent-phosphate complex. A comparison of some properties of one-band cytochrome c1 with those of two-band cytochrome c1 clearly showed significant differences between the two preparations. These results suggest the hypothesis that one of the possible roles of the hinge protein in the mitochondrial respiratory chain is to stabilize the conformation of cytochrome c1.

Mechanisms of canine gastric dysrhythmia

We postulated that local synthesis and release of prostaglandins might be the paracrine pathway that triggers gastric dysrhythmia when exogenously activated. The study was divided into three parts. In part 1, a dose-response study was performed in 7 dogs to estimate the 95% effective dose for four pharmacologic agents known to cause gastric dysrhythmia. In part 2, we determined the relative efficacy of three putative blockers in preventing pharmacologic induction of gastric dysrhythmia. In part 3, several ancillary experiments were performed. The results show that an intraarterial bolus of epinephrine, met-enkephalin, prostaglandin E2, and glucagon each induced episodes of gastric dysrhythmia, whereas saline injections did not. The 95% effective dose of these dysrhythmic drugs were 10.5, 77.0, 35.0, and 407.0 micrograms/kg, respectively. The dysrhythmic action of epinephrine was blocked by phentolamine and indomethacin but not by naloxone. The dysrhythmic action of met-enkephalin was blocked by naloxone and indomethacin but not by phentolamine. The dysrhythmic action of glucagon was not blocked by phentolamine, naloxone, or indomethacin. The inhibitory effect of indomethacin on epinephrine-induced gastric dysrhythmia was shared by meclofenamate. Thus, we conclude that local prostaglandins mediate the production of gastric dysrhythmias by epinephrine and met-enkephalin; however, glucagon causes gastric dysrhythmias by a non-prostaglandin-mediated mechanism.

Acute otitis media caused by Branhamella catarrhalis: biology and therapy

Since 1980, we have observed an epidemic of otitis media caused by Branhamella catarrhalis. This event was characterized by studying the nasopharyngeal colonization of infants and children with B. catarrhalis and the clinical presentation and therapeutic outcome of acute otitis media caused by this organism. Pharyngeal colonization with B. catarrhalis was commoner in winter than summer. B. catarrhalis was present in middle-ear fluid (MEF) of 17% of children with otitis media, and was commoner in fall and winter (20%) than in spring and summer (11%, P less than .05). Seventy-five percent of isolates produced beta-lactamase (Ravasio type). In five of 20 patients, treatment with beta-lactamase-susceptible agents failed to sterilize B. catarrhalis-infected MEF. All of these five patients were infected with beta-lactamase-producing strains. The increasing prominence of antibiotic-resistant B. catarrhalis in acute otitis media may lead to a reevaluation of initial antibiotic therapy for acute otitis media, particularly in winter or in areas where colonization with such strains is prevalent.

Prevalence of colonization with antibiotic resistant gram-negative bacilli in a nursing home care unit: the importance of cross-colonization as documented by plasmid analysis

A prevalence study was carried out on a 100-bed Veterans Administration nursing home care unit to determine the extent of colonization with gentamicin-resistant gram-negative bacilli (GRGNB). Hand cultures of 12 employees and 17 environmental cultures were negative. Twenty-six of 86 (30%) patients were colonized with 49 GRGNB. Sixteen patients (19%) had urinary colonization. Multivariate analysis revealed significant associations between rectal or perineal colonization (P less than 0.01), and the presence of a urinary device (82% condom catheters) (P less than 0.05), with urinary colonization. The most common isolates were Providencia stuartii (20), Escherichia coli (nine) and Klebsiella pneumoniae (nine). Twenty-six of 49 isolates carried plasmids. Restriction endonuclease digestion of plasmid DNA was performed for 21. Cross-colonization, as defined by the presence of the identical species with the identical restriction endonuclease digestion profile of purified plasmid DNA found in different patients, was observed for eight of 21 (38%) strains. All were geographically clustered. No strains could transfer gentamicin-resistance by conjugation and only two plasmids could transform our E coli recipient to gentamicin resistance. One E coli plasmid was identical to two Citrobacter freundii plasmids and a P stuartii plasmid isolated from three different patients. This 105 kb plasmid is conjugative and encodes resistance to ampicillin, carbenicillin, tetracycline, and sulfonamides. Thus, 57% of strains were cross-colonizing or contained identical R-plasmids. Southern hybridization using a 1 kb TEM-1 gene probe demonstrated sequences homologous to this probe in five of five nursing home plasmids examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis of pyrimidin-2-one nucleosides as acid-stable inhibitors of cytidine deaminase

One of the problems encountered in the use of tetrahydrouridine (THU, 2) and saturated 2-oxo-1,3-diazepine nucleosides as orally administered cytidine deaminase (CDA) inhibitors is their acid instability. Under acid conditions these compounds are rapidly converted into inactive ribopyranoside forms. A solution this problem was sought by functionalizing the acid-stable but less potent CDA inhibitor 1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (1) with the hope of increasing its potency to the level achieved with THU. The selection of the hydroxymethyl substituent at C-4, which led to the synthesis of 4-(hydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (10), 3,4-dihydro-4-(hydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (7), and 3,4,5,6-tetrahydro-4-(dihydroxymethyl)-1-beta-D-ribofuranosyl-2(1H)-p yrimidinone (28) was based on the transition-state (TS) concept. The key intermediate precursor, 4-[(benzoyloxy)methyl]-1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-2(H) -pyrimidinone (24), was obtained via the classical Hilbert-Johnson reaction between 2-methoxy-4-[(benzoyloxy)methyl]pyrimidine (20) and 2,3,5-tri-O-benzoyl-1-D-ribofuranosyl bromide (21). Deprotection of 24 afforded compound 10, while its sodium borohydride reduction products afforded compounds 7 and 28 after removal of the blocking groups. Syntheses of 3,4-dihydro-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (9) and 3,6-dihydro-1-beta-D-ribofuranosyl-2(1H)-pyrimidinone (8), which lack the hydroxymethyl substituent, was accomplished in a similar fashion. The new compounds bearing the hydroxymethyl substituent were more acid stable than THU, and their CDA inhibitory potency, expressed in terms of Ki values, spanned from 10(-4) to 10(-7) M in a manner consistent with the TS theory. Compound 7, in particular, was superior to its parent 1 and equipotent to THU (Ki = 4 X 10(-7) M) when examined against mouse kidney CDA. The superior acid stability of this compound coupled to its potent inhibitory properties against CDA should provide a means of testing oral combinations of rapidly deaminated drugs, viz. ara-C, without the complications associated with the acid instability of THU.

Electrical activity of the stomach: clinical implications

Disorders of gastrointestinal motility are increasingly being recognized with the aid of such innovative techniques as gastrointestinal manometry and radioscintigraphy. Applications of these techniques have expanded and refined our present understanding of the gut motility both in health and in disease. Recent studies have shown that disturbances of motility can be limited to a specific segment of the gut such as the stomach or can affect the entire gastrointestinal tract. Because gastrointestinal motility is controlled by electrical activity, increasing efforts are being made to characterize and quantify the underlying electrical disturbances in various disorders of gastrointestinal motility. In this article, we review the electrical basis of gastric motility and the clinical implications of gastric dysrhythmia.

Characteristics of spontaneous and drug-induced gastric dysrhythmias in a chronic canine model

We developed a chronic canine model to study electrical characteristics of both spontaneously occurring and drug-induced gastric dysrhythmias. Seven female dogs were fitted with a catheter chronically implanted in the left gastric artery, and five monopolar silver-silver chloride electrodes were sutured to the serosa of the stomach and proximal duodenum. Three dogs exhibited spontaneous dysrhythmia, and in 4 other dogs, dysrhythmias were drug-induced. Ninety-seven episodes of spontaneous dysrhythmia and 21 episodes of drug-induced dysrhythmia were recorded and analyzed. All episodes of tachygastria were first detected in the distal antrum, and the tachygastric pacesetter potentials usually spread orally. All but one episode of bradygastria were detected both in the corpus and the antrum simultaneously. During bradygastria, pacesetter potentials spread aborally. Spontaneous and drug-induced dysrhythmias exhibited similar characteristics. Therefore, we conclude that the origin and propagation characteristics of gastric dysrhythmias depend on the type of dysrhythmia rather than whether they are spontaneous or drug-induced.

In vitro activity of cefpimizole sodium (U-63196E) and other antimicrobial agents against Haemophilus isolates from pediatric patients

In vitro activity of cefpimizole, an experimental third generation cephalosporin, and 10 other antimicrobials (ampicillin, azlocillin, cefamandole, cefoperazone, cefotaxime, mezlocillin, moxalactam, piperacillin, rifampin and sulfamethoxazole/trimethoprim) were determined for 181 isolates of Haemophilus obtained from pediatric patients. For 156 beta-lactamase-negative isolates, MIC50 values of cefoperazone, cefpimizole, and cefamandole were 4, 8, and 16 times greater than those of moxalactam and cefotaxime (0.06 micrograms/ml). 25 beta-lactamase-producing isolates were resistant to ampicillin, azlocillin, mezlocillin, and piperacillin, however, MIC50 of all third generation cephalosporin were similar to those obtained for beta-lactamase-negative organisms. Rifampin and SMX/TMP demonstrated low MIC50 values for all isolates.

Overlapping transcription of the nifA regulatory gene in Rhizobium meliloti

Gene fusions were used to demonstrate complex overlapping transcriptional controls of the regulatory gene nifA in Rhizobium meliloti bacteroids isolated from alfalfa root nodules. Gene nifA has previously been shown to be transcribed from promoter PnifA and to be required for activation of promoters P1 (nifHDK) and P2 (fixABC) during symbiotic nitrogen fixation with alfalfa. P2 is located approximately 4 kb upstream from nifA and is shown in this report to be responsible for at least one-half of the nifA expression observed in bacteroids. Substantial transcription of nifA occurs during symbiosis as evidenced by the fact that PnifA was found to be 53% as active as either P1 or P2. Together, the data indicate that more than half of the transcripts initiated at P2 fail to terminate before reaching nifA. Additional studies indicated that there may be weak promoter activity in the symbiotically essential region downstream from nifA.

Discrepancies in fluorescent antibody, counterimmunoelectrophoresis, and Neufeld test for typing of Streptococcus pneumoniae

The techniques of fluorescent antibody (FA) and counterimmunoelectrophoresis (CIE) were compared with the Neufeld test (quellung reaction) for typing of Streptococcus pneumoniae. A total of 88 isolates were examined by these three methods. Pool-, type-, or group-specific pneumococcal antisera were used in all three methods. Each isolate was initially tested with polyvalent antisera and all of the nine pools of antisera. Selection of the type- or group-specific antisera depended upon the reaction of the isolate with the pool sera. Sixty-eight of 88 (77.3%) isolates were positive using pool or typing sera and were correctly typed by CIE, while FA was found to be accurate for only 61 of 88 (69.3%) isolates. Positive reactions with more than one pool- or type-specific antisera, or no reaction, were seen with several of the isolates with both techniques. Even though CIE and FA are rapid and simple techniques, microbiologists should be cautious when utilizing them for typing of S. pneumoniae because of the discrepancies observed in this study.

Three-dimensional reconstruction of cytochrome oxidase vesicle crystals prepared by cholate solubilization

Cytochrome oxidase vesicle crystals with long-range order have been obtained from cholate-solubilized, highly purified reconstitutively active preparations. These crystals, which are suitable for electron-microscopic structure investigation, show pgg symmetry in the 0 degree projection. Using Fourier reconstruction and modified back-projection methods, a three-dimensional reconstruction has been obtained at a resolution of 25 A. Our structural results are in agreement with the model of Henderson et al. [J. Mol. Biol. 112, 631 (1977)] obtained for their Triton-derived crystals.

Acidic ribosomal proteins of Neurospora crassa

Neurospora crassa acidic ribosomal proteins from the high salt-ethanol extract of 80 S ribosomes have been fractionated by DEAE-cellulose chromatography. Six acidic ribosomal proteins were purified. All resemble Escherichia coli L7 and L12 in amino acid composition and molecular weight but each has a slightly different net charge at pH 3.2. Four have an apparent molecular weight of approx. 14 000, and two have a molecular weight of approx. 14 800. The amino acid compositions and circular dichroism (CD) spectra of the purified Neuropsora proteins are identical for the four 14 kDa proteins, but clearly distinguishable from the two 14.8 kDa proteins. The latter are also identical in amino acid composition and CD spectra. This suggests that there are two Neurospora acidic, or 'A', proteins, one of which exists in four microheterogeneous forms and the other exists in two forms.

Kinetics of electron transfer between cardiac cytochromes c1 and c

Highly purified cytochrome c1, which consists of only one heme peptide and does not form a stable c1-c complex (c1-H-c complex), was used in studies of electron transfer between cytochrome c1 and c. Results show that a stable and ionic-strength-sensitive c1-c complex (i.e., the c1-H-c complex) in the forms of the various oxidation states is not required, in contrast to the current belief of the participation of the complex in the electron transfer between cytochromes c1 and c. A minimum mechanism for electron transfer between these two cytochromes is suggested in accord with the experimental results.

Catalysis of nitrosyl transfer reactions by a dissimilatory nitrite reductase (cytochrome c,d1)

The dissimilatory nitrite reductase (cytochrome c,d1) from Pseudomonas aeruginosa was observed at pH 7.5 to catalyze nitrosyl transfer (nitrosation) between [15N]nitrite and several N-nucleophiles or H2 18O, with rate enhancement of the order of 10(8) relative to analogous chemical reactions. The reducing system (ascorbate, N,N,N',N'-tetramethylphenylenediamine) could reduce nitrite (but not NO) enzymatically and had essentially no direct chemical reactivity toward nitrite or NO. The N-nitrosations showed saturation kinetics with respect to the nucleophile and, while exhibiting Vmax values which varied by about 40-fold, nevertheless showed little or no dependence of Vmax on nucleophile pKa. The N-nitrosations and NO-2/H2O-18O exchange required the reducing system, whereas NO/H2O-18O exchange was inhibited by the reducing system. NO was not detected to serve as a nitrosyl donor to N-nucleophiles. These and other kinetic observations suggest that the enzymatic nitrosyl donor is an enzyme-bound species derived from reduced enzyme and one molecule of nitrite, possibly a heme-nitrosyl compound (E-FeII X NO+) for which there is precedence. Nitrosyl transfer to N-nucleophiles may occur within a ternary complex of enzyme, nitrite, and nucleophile. Catalysis of nitrosyl transfer by nitrite reductase represents a new class of enzymatic reactions and may present another example of electrophilic catalysis by a metal center. The nitrosyl donor trapped by these reactions is believed to represent an intermediate in the reduction of nitrite by cytochrome c,d1.

Bacterial and fungal growth in intravenous fat emulsions

Growth of bacterial and fungal organisms in i.v. fat emulsions was studied. A total of 81 isolates of 15 bacterial and fungal strains were used to inoculate (in test tubes) 10% soybean oil emulsion (Intralipid, Cutter Laboratories), 10% safflower oil emulsion (Liposyn, Abbott Laboratories), trypticase soya broth, and 0.9% sodium chloride at about 2500 organisms/ml. Duplicate samples and negative controls were prepared. Samples were handled under two procedures after inoculation: (1) initially refrigerated overnight, then stored at room temperature for 24 hours, and (2) stored only at room temperature for 24 hours. Samples were taken at 3, 7, and 24 hours after the samples were placed at room temperature, and colony counts were performed. Most organisms grew equally well in the fat emulsions and trypticase soya broth. Fungal strains grew more slowly than bacterial strains but reached equal numbers by 24 hours. Organisms grew quite slowly in sodium chloride, and negative controls showed no growth. These i.v. fat emulsions supported bacterial and fungal growth at the same level as trypticase soya broth.

A mitochondrial protein essential for the formation of the cytochrome c1-c complex. Isolation, purification, and properties

A new mitochondrial protein was isolated to pure form. This protein was indispensable for the formation of the cytochrome c1-c complex; hence, it was provisionally named the hinge protein for formation of the cytochrome c1-c complex, or for simplicity, merely called the hinge protein. The simplest method for the preparation of the pure protein involved essentially pH 5.5 treatment of high purity of "two-band" cytochrome c1 prepared from an improved method. The use of two band cytochrome c1 prepared by an improved method was preferred because the improved method apparently yielded less tight bonding between the heme-containing and colorless protein entities than that from the original methods (King, T. E. (1978) Methods Enzymol. 53, 181-191). The c1-c complex comprised 1 molar equivalent each of the hinge protein, "one-band" cytochrome c1 and cytochrome c. It was demonstrated by gel filtration chromatography that in the absence of the hinge protein, there was no complex formation between cytochromes c and one-band c1. In titration of the complex formed between one-band cytochrome c1 and cytochrome c with the hinge protein present by using the increase of the Soret-Cotton effect as a criterion (Chiang, Y. L., Kaminsky, L. S., and King, T. E. (1976) J. Biol. Chem. 251, 29-36), a sharp break was observed which showed the three species to be present in equivalent amounts. The hinge protein showed low extinction in the 280 nm region and exhibited poor color value and diffuse character of the band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis after staining with Coomassie brilliant blue. The molecular weight was found to be (i) 9,800 from sedimentation equilibrium, (ii) 11,000 from sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and (iii) 23,000 with a Stokes radius of 22.4 A from gel filtration chromatography estimated from a standard curve with proteins of known molecular parameters. The disparities in these data from the actual value of 9,175 from calculations based on amino acid sequence, as previously reported (Wakabayashi, S., Takeda, H., Matsubara, H., Kim, C. H., and King, T. E. (1982) J. Biochem. (Tokyo) 91, 2077-2085), have been discussed.

15N tracer studies on the reduction of nitrite by the purified dissimilatory nitrite reductase of Pseudomonas aeruginosa. Evidence for direct production of N2O without free NO as an intermediate

Nitrite reductase (cytochrome c,d1) was purified from Pseudomonas aeruginosa. In the presence of the reducing system, ascorbate-N,N,N',N'-tetramethylphenyl-enediamine, which alone had no ability to reduce nitrite or NO at pH 7.5, the enzyme catalyzed the reduction of nitrite to NO and N2O as major and minor products, respectively, as determined by gas chromatography-mass spectrometry. The rate of reduction of NO to N2O was considerably lower than the rate of reduction of nitrite to N2O and might be zero. The N2O produced in a system containing [15N]nitrite and natural NO was more highly enriched in 15N than was the NO pool and, in this regard, closely resembled the enrichment of the nitrite pool. The amount of 14N in the NO pool changed little, if any, as the result of enzymatic processes. For the enzyme, free NO seems not to be an intermediate between nitrite and N2O, just as was found by this laboratory for certain intact denitrifying bacteria. The results are consistent with reduction of nitrite to enzyme-bound NO, which can partition between release and further reduction.

Messenger RNA for ribosomal proteins in yeast

The concentrations and mean lifetimes of the messenger RNAs for four ribosomal proteins of the yeast, Saccharomyces cerevisiae, have been determined by the method of approach to equilibrium labeling, using cloned genes as hybridization probes. In cells growing in a minimal medium with glucose as a carbon source, there are roughly equimolar amounts of the four mRNAs, whose half-lives are very similar: 14 +/- 2 minutes, approximately 10% of a generation time. These results lead to an analysis of the economy of mRNA for ribosomal proteins that suggests that the mRNAs may be substantially underutilized.

Mild temperature shock alters the transcription of a discrete class of Saccharomyces cerevisiae genes

In Saccharomyces cerevisiae the synthesis of ribosomal proteins declines temporarily after a culture has been subjected to a mild temperature shock, i.e., a shift from 23 to 36 degrees C, each of which support growth. Using cloned genes for several S. cerevisiae ribosomal proteins, we found that the changes in the synthesis of ribosomal proteins parallel the changes in the concentration of mRNA of each. The disappearance and reappearance of the mRNA is due to a brief but severe inhibition of the transcription of each of the ribosomal protein genes, although the total transcription of mRNA in the cells is relatively unaffected by the temperature shock. The precisely coordinated response of these genes, which are scattered throughout the genome, suggests that either they or the enzyme which transcribes them has unique properties. In certain S. cerevisiae mutants, the synthesis of ribosomal proteins never recovers from a temperature shift. Yet both the decline and the resumption of transcription of these genes during the 30 min after the temperature shift are indistinguishable from those in wild-type cells. The failure of the mutant cells to grow at the restrictive temperature appears to be due to their inability to process the RNA transcribed from genes which have introns (Rosbash et al., Cell 24:679-686, 1981), a large proportion of which appear to be ribosomal protein genes.

Emergence of beta-lactamase-producing strains of Branhamella catarrhalis as important agents of acute otitis media

We performed a prospective study to monitor changes in the bacterial etiology of acute otitis media. Branhamella catarrhalis was isolated from middle ear exudates of 3 of 47 children (6.4%) studied between September 1979 and September 1980 and from 26 of 98 children (26.5%) studied between October 1980 and February 1982 (P = 0.0055). Twenty of 26 B. catarrhalis strains (76.9%) were found to be resistant to ampicillin and to produce beta-lactamase. In contrast only 2 of 26 strains of Haemophilus influenzae (7.7%) isolated from the same group of patients were resistant to ampicillin. We could not detect changes in culture methods, in demographic features, in patterns of medical care or in prior middle ear disease or antimicrobial drug usage, which might explain this striking increase in the relative importance of resistant strains of B. catarrhalis.

Synthesis and pharmacological activity of 6-aryl-2-azabicyclo[4.2.1]nonanes

A series of 6-phenyl-, 6-(m-methoxyphenyl)-, and 6-(m-hydroxyphenyl)-2-azabicyclo[4.2.1]nonanes was synthesized by a sequence involving alkylation of an appropriate 2-arylcyclopentanone with an aminoalkyl substituent. Subsequent ring closure at the other alpha position on the cyclopentanone ring and Wolff-Kishner reduction afforded the title compound. Several derivatives of these materials showed activity in an antinociceptive assay comparable to codeine. Most analogues were either inactive or toxic.

Structural studies of bovine heart cytochrome c1

The complete primary structure of bovine heart cytochrome c1 was established by analyses of peptide fragments prepared by digestion using trypsin, staphylococcal protease, and chymotrypsin and by cyanogen bromide cleavage of cytochrome c1 and its derivatives. The total number of amino acid residues is 241, giving a molecular weight of 27,924 including the heme group. The NH2- and COOH-terminal residues are serine and lysine, respectively. One characteristic of the protein is that cytochrome c1 contains 43.6% hydrophobic residues and the polarity is estimated to be 41.1%. No clear homology was found between cytochrome c1 and other membranous proteins such as cytochrome b5 or the subunits of cytochrome oxidase for which sequences have been reported. Cytochrome c1 is predicted to have a high content of alpha-helix (46%). Partial sequence studies were also carried out on cytochrome c1 preparations obtained by different procedures and showed that there is no difference among the sequences of various preparations of cytochrome c1. The presence of a hydrophobic cluster near the COOH-terminal region indicates that the COOH-terminal region of cytochrome C1 associates with, or is buried in, the phospholipid bilayer of the mitochondrial membrane.

13N isotope studies on the pathway of ammonia assimilation in Bacillus megaterium and Escherichia coli

The pathway of ammonia incorporation into amino acids was studied by use of 13N-ammonium ions in Bacillus megaterium and Escherichia coli that had been grown aerobically on a minimal salts medium containing NH4Cl as the source of nitrogen. Anion- and cation-exchange high-pressure-liquid chromatography was used to separate amino acids relevant to the several possible pathways for ammonia assimilation in bacteria. At an initial concentration of added NH4+ of 1 microM, the glutamine synthetase-glutamate synthase pathway represented the major pathway in both bacteria on the basis of the effects of inhibitors of that pathway (L-methionine-DL-sulfoximine and azaserine) and of transamination (aminooxy-acetate) and the observation that the specific activity of glutamine was greater initially than that of any other amino acid likely to be the first product of an assimilation pathway. The study provides (i) a new analytical method for 13N-tracer investigation of amino acids, (ii) confirmation of conclusions from enzymological studies on the pathway of ammonia assimilation in B. megaterium and E. coli, and (iii) proof that alanine dehydrogenase and aspartate ammonia lyase (aspartase) are not important pathways in B. megaterium at low NH4+ concentrations.