Inhibitory effects of metronidazole on anaerobic metabolism of phenylalanine and leucine by Peptostreptococcus anaerobius

The metabolism of phenylalanine and leucine by Peptostreptococcus anaerobius and the effects of metronidazole on this metabolism were studied. The cells metabolized both phenylalanine and leucine under strict anaerobic conditions and produced hydroxylated products (i.e. phenyllactate from phenylalanine and hydroxyisocaproate from leucine). Other products were phenylpropionate, cinnamate and phenylacetate from phenylalanine; isocaproate, alpha-ketoisocaproate and isovalerate from leucine. Metronidazole inhibited the production of all end-products, with the exception of phenyllactate and hydroxyisocaproate which were increased. Similarly, when the reaction was carried out aerobically, the cells also metabolized both phenylalanine and leucine and all end-products were inhibited again with the exception of phenyllactate and hydroxyisocaproate. Our results suggest that the inhibitory mode of metronidazole is similar to that of oxygen.

In-vitro antibacterial susceptibility of bacteria taken from infected root dentine to a mixture of ciprofloxacin, metronidazole and minocycline

The aim of this study was to clarify the antibacterial effect of a mixture of ciprofloxacin, metronidazole and minocycline, with and without the addition of rifampicin, on bacteria taken from infected dentine of root canal walls. The efficacy was also determined against bacteria of carious dentine and infected pulps which may the precursory bacteria of infected root dentine. This efficacy was estimated in vitro by measuring bacterial recovery on BHI-blood agar plates in the presence or absence of the drug combination. Bacteria ranging in number from 10(2) to 10(6) occurred in samples of infected root dentine (27 cases). However, none was recovered from the samples in the presence of the drug combination at concentrations of 25 micrograms ml-1 each. The respective drug alone (10, 25, 50 and 75 micrograms ml-1) substantially decreased the bacterial recovery, but could not kill all the bacteria. Bacteria taken from carious dentine (25 cases) and infected pulps (12 cases) were also sensitive to the drug combination. These results may indicate that the bactericidal efficacy of the drug combination is sufficiently potent to eradicate bacteria from the infected dentine of root canals.

[Anaphylactoid purpura: intestinal ultrasonographic findings]

We evaluated six children with anaphylactoid purpura for ultrasonographic changes in the small intestine. Of 16 ultrasonographic scans, eight showed abnormal findings, consisting of circumscribed hypo-echoic enlargement, reduced peristalsis, equivocal structure of the small intestinal wall and ascites in patients with abdominal pain. Follow-up ultrasonography after steroid therapy demonstrated the small intestine to be normal in four of six patients. We believe that ultrasonography is an useful diagnostic modality to detect changes in the small intestinal wall in anaphylactoid purpura and plays an important role in its differentiation from other causes of abdominal pain.

[Unknown fever and abnormal liver functions after repeated epidural blocks with lidocaine for management of herpes zoster pain]

We present a case of unknown fever and abnormal liver functions which developed during the course of pain management for herpes zoster with repeated epidural blocks with 0.5% lidocaine 10 ml. The patient was a 67 year old woman. At her first admission to dermatology, there were no abnormal findings in her blood examinations. She complained of severe pain from herpes zoster. She was admitted to the pain clinic. She received thoracic epidural blocks with 0.5% lidocaine 10 ml repeatedly three or four times a week. Two weeks later, she developed general fatigue, appetite loss, nausea and a high fever. Blood examinations revealed the elevation of glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), alkaline phosphatase (ALP), and gamma glutamyltrans peptidase (gamma-GTP), C reactive protein (CRP), and blood sedimentation rate (BSR). Many examinations including abdominal and thoracic computer tomography and abdominal echograph could not reveal the cause of high fever and abnormal blood examinations. We continued the thoracic epidural block for her herpes zoster pain. GOT, GPT, ALP, and gamma-GTP gradually went down to normal values in next two weeks, though fever still persisted. At this time, lymphocyte cell simulation test with 0.5 % lidocaine was positive and eosinophylic cell had increased to 5%. After ceasing the epidural block, fever resolved and blood examinations returned to normal values. These findings suggest strongly that 0.5% lidocaine induced fever and hepatitis.

In vitro antimicrobial susceptibility to combinations of drugs on bacteria from carious and endodontic lesions of human deciduous teeth

The purpose of this study was to clarify the antibacterial efficacy of mixed antibacterial drugs on bacteria of carious and endodontic lesions of human deciduous teeth in vitro. The antibacterial drugs used in this study were mixtures of ciprofloxacin, metronidazole, plus a third antibiotic: amoxicillin, cefaclor, cefroxadine, fosfomycin or rokitamycin. Samples taken from carious dentin (17 cases) and infected pulpal tissues (14 cases) were cultured on control plates and plates containing the mixed drugs. No bacteria were recovered in the presence of any combination of the mixture of the drugs (100 micrograms each/ml), and the bacterial growth occurred on control plates (10(1) to 10(7) colony-forming units), indicating that the mixed drugs inhibit the growth of bacteria in the samples. When carious and endodontic lesions on split surfaces of freshly extracted teeth were covered overnight with alpha-tricalcium phosphate cement containing a mixture of ciprofloxacin, metronidazole and cefaclor (1% each; 5 cases), no bacteria were recovered from the lesions. No bacteria were recovered from carious and endodontic lesions when these lesions were immersed in a solution of the mixture (200 micrograms each/ml; 5 cases). These findings indicate that carious and endodontic lesions can be sterilized by the mixed drugs in situ.

[Obstetric anesthesia in Gifu]

Improvement of perinatal mortality rate in Japan is remarkable for the last two decades, but maternal mortality rate is still relatively high in comparison with the improvement of the perinatal mortality rate. Maternal mortality rate 1991 in Japan was 8.5. Maternal deaths occurred mostly in perinatal period. The causes of death include pre- and postpartum hemorrhage, pulmonary embolism, and hypertension. This means an intensive, vigorous therapy including anesthesia management is necessary during peripartum period. Questionnaires were mailed to 63 maternity clinics in Gifu area. Some of the questions requested as many answers as applicable. We received 51 replies to questionnaires. Average Cesarean rate in Gifu was 7.3%. Spinal anesthesia was used in 74.5% of maternity clinics. Dibucaine was the most widely used local anesthetic for spinal anesthesia. Antacid medications were rare in our study group. After induction of general anesthesia, airway was maintained by masks (36.0%) or endotracheal tube (64.0%). Obstetric analgesia by local anesthetics was not used widely.

Eubacterium saphenum sp. nov., isolated from human periodontal pockets [corrected]

A new species, Eubacterium saphenum [corrected] sp. nov., established on the basis of the results of DNA-DNA hybridization, was proposed for strains isolated from human periodontal pockets. Differential characteristics are given.

Predominant obligate anaerobes in human periodontal pockets

This study was carried out to investigate the predominant anaerobic bacteria of periodontal pockets in patients with advanced periodontitis, who had no previous treatment other than supragingival scaling, no history of recent or chronic systemic illness, nor any intake of antibiotics within 6 weeks prior to bacteriological sampling. Care was taken not to ignore tiny-colony-forming anaerobes, by means of a stereoscope and an anaerobic glove box system. Out of 422 (100%) isolates, 380 (90%) were obligate anaerobes, suggesting that the environment in periodontal pockets was anaerobic and favors the growth of obligate anaerobes. Among the 380 obligate anaerobes isolated, strains belonging to Eubacterium (54%) were predominant, and many of them occurred in tiny colonies. The other obligate anaerobes isolated were assigned to Wolinella (9%), unidentified motile rods which resemble Wolinella (7%), Peptostreptococcus (6%), Fusobacterium (5%), Bacteroides (2%; including those reclassified to Prevotella and Porphyromonas) and Selenomonas (0.5%). Among the isolates, 67% were Gram-positive bacteria, including 59% of rods (mostly asaccharolytic Eubacterium), suggesting that these bacteria, particularly strains of the Eubacterium species, may play an important role in etiology of adult periodontitis.

Acute effect of hypobaria and hypoxia on renal nerve activity in anaesthetized rabbits

To determine the acute effect of reduced barometric pressure and hypoxia on renal nerve activity, urethane-anaesthetized and mechanically ventilated rabbits were randomly exposed to the following four separate conditions in a decompression chamber: hypoxic hypobaria (n = 7), hypoxic normobaria (n = 5), normoxic hypobaria (n = 8) and slow normoxic hypobaria (n = 7). A combination of rapid decompression and simultaneous adjustment of inspired PO2 was used to simulate an altitude of 6600 m, and renal nerve activity and haemodynamics, such as systemic blood pressure and heart rate, were measured. During both hypoxic hypobaria and hypoxic normobaria, there were significant and similar increases in renal nerve activity at 6600 m (54 +/- 7% and 61 +/- 13% from each baseline, respectively). However, there were no changes in renal nerve activity during normoxic hypobaria or slow normoxic hypobaria with decompression rates of 1000 or 400 m min-1, respectively. From these results, we conclude that a reduction in barometric pressure without hypoxia does not affect renal nerve activity in anaesthetized rabbits.

Effect of hypertonic saline infusion on renal vascular resistance in anesthetized dogs

Changes in renal vascular resistance (RVR) and their mechanisms were investigated following infusion of 7.5% hypertonic saline (4 ml/kg) in anesthetized dogs. In all animals the left kidney was perfused at a constant perfusion flow (59 +/- 6 ml/min) with heparinized blood using a pulsatile roller pump. Renal perfusion pressure (RPP), systemic blood pressure (SBP), central venous pressure (CVP), and heart rate (HR) were measured simultaneously. Electrical stimulation of renal sympathetic nerves was also performed to evaluate the neurally mediated change in renal vasculature before and after infusion of hypertonic saline. In animals with intact vagi, intravenous administration of hypertonic saline resulted in significant increases in both mean blood pressure (MBP) and CVP, and caused significant decreases in HR and RVR. These effects were not affected by bilateral cervical vagotomy. In both intact and vagotomized animals, changes in RVR in response to renal nerve stimulation were attenuated after infusion of hypertonic saline. These results suggest that reduction in RVR after intravenous infusion of hypertonic saline is not a reflex effect mediated by vagal afferents. Instead, vascular response of the renal artery to hypertonic saline may result from a suppression of neurotransmission from renal sympathetic nerve endings to renal vascular smooth muscle.

Inhibitory effect of renal nerve activity during canine anaphylactic hypotension

We have examined baroreceptor regulation of renal nerve activity (RNA) during anaphylactic hypotension that affects renal nerve activity. In anesthetized dogs, mean blood pressure (MBP), heart rate (HR), and RNA were simultaneously measured. To test for a normally functioning baroreceptor reflex in each animal, a transient hypotension was induced by an intravenous injection of sodium nitroprusside (4 micrograms/kg). Nitroprusside produced a reflex increase in RNA (+63 +/- 12% at -20 mmHg and +139 +/- 8% at -40 mmHg) and HR (+13 +/- 1 beats/min at -20 mmHg and +21 +/- 2 beats/min at -40 mmHg). However, intravenous administration of Ascaris suum antigen in animals with an intact neuraxis caused a decrease in RNA (-15 +/- 14% at -20 mmHg and -42 +/- 11% at -40 mmHg blood pressure during the antigen-induced hypotension) in parallel with a fall in systemic blood pressure. HR responses were -5 +/- 2 beats/min at -20 mmHg and -10 +/- 1 beats/min at -40 mmHg during the hypotension induced by the antigen. In animals with combined denervation of the carotid sinus and vagal nerves, HR did not change significantly during anaphylactic hypotension. However, a decrease in RNA remained (-60 +/- 4% at -20 mmHg and -72 +/- 4% at -40 mmHg of hypotension). The decrease in RNA after antigen administration was significantly greater after denervation than in animals with an intact neuraxis. These results indicate that systemic baroreceptor reflex control of RNA is reduced during anaphylactic hypotension. Impaired reflex control of sympathetic nerve activity may result from an impairment of sympathetic outflow through the central nervous system.

Reflex effects on renal nerve activity and renal vascular tone during occlusion of superior mesenteric artery in anesthetized dogs

This study was designed to evaluate the contribution of the systemic baroreceptor reflex on renal nerve activity (RNA) and renal vascular resistance (RVR) during occlusion of the superior mesenteric artery (SMAO) in anesthetized dogs. Animals were divided into two groups; RVR evaluated group and RNA measured group. For evaluation of changes in RVR, the left kidney was perfused at a constant flow with heparinized blood by using a pulsatile roller pump. Renal perfusion pressure, arterial blood pressure and heart rate were measured simultaneously. During SMAO, MAP and RVR increased significantly in animals with intact systemic baroreceptors. After combined denervation of the carotid sinus and vagal nerves, a significant enhancement of this RVR response during SMAO occurred and the level of changes in RVR were significantly greater than those in animals with an intact neuraxis. In the RNA measured group, renal sympathetic nerve activity, arterial blood pressure and heart rate were measured simultaneously before and during SMAO. During SMAO, MAP and RNA increased significantly in animals with intact systemic baroreceptors. These MAP and RNA responses to SMAO were significantly enhanced in animals with combined denervation of the carotid sinus and vagal nerves. These results indicate that SMAO evokes an increase in arterial blood pressure, renal sympathetic nerve activity and renal vascular resistance. The reflex increase in renal nerve activity and renal vascular tone during SMAO is modified and minimized by an activation of systemic baroreceptors.

Contribution of baroreceptor reflexes to blood pressure and sympathetic responses to cholecystokinin and vasoactive intestinal peptide in anesthetized dogs

The effects of synthetic vasoactive intestinal peptide (VIP) and cholecystokinin (CCK) on systemic blood pressure and renal nerve activity were studied before and after cervical vagotomy, and sino-aortic denervation with vagotomy in anesthetized dogs. Intravenous injection of VIP (5 micrograms/kg) in animals with an intact neuraxis produced a significant decrease in systemic blood pressure and a significant increase in renal nerve activity. These responses to VIP did not change after vagotomy and after complete denervation, VIP did not cause any change in renal nerve activity, even during hypotension. The level of hypotension after complete denervation was greater than that under other conditions. These results indicate that the cardiovascular effects of VIP are reduced by activation of the systemic baroreceptors. Intravenous injection of CCK (10 micrograms/kg) in animals with an intact neuraxis produced significant decreases in blood pressure and renal nerve activity. These responses to CCK were abolished in animals with cervical vagotomy only. However, following complete denervation of the carotid sinus and total section of the vagal nerves, CCK caused a significant increase in blood pressure and renal sympathetic nerve activity. These results indicate that the sympathetic depressor effect of CCK may be mediated by activation of the vagal afferents, and that the sympathetic pressor effect may be due to a direct action of CCK on the central nervous system. Thus, each gastrointestinal peptide may regulate the cardiovascular system through a different mechanism.

Reflex responses on blood pressure and renal nerve activity to local intra-arterial injection of capsaicin in anesthetized dogs

The present study was performed to examine effects of intra-arterial and intravenous injection of capsaicin on efferent renal sympathetic nerve activity (RNA) in pentobarbital anesthetized dogs. In animals with intact baroreceptors, intra-arterial injection of capsaicin (4 +/- 1 microgram) produced significant increases in mean blood pressure (MBP) and heart rate (HR) by +43 +/- 8 mmHg and +33 +/- 15 beats/min at 20 s after the injection, respectively. There followed a recovery toward the control so that 60 s after the intra-arterial injection changes in MBP and HR were +8 +/- 5 mmHg and +18 +/- 8 beats/min, respectively. RNA showed a biphasic response, comprising of an initial increase (+52 +/- 28% of the control at 20 s) followed by a decrease by -30 +/- 8% of the control 60 s after the injection. Following bilateral cervical vagotomy the initial increase in RNA did not differ significantly from the value of RNA in animals with intact baroreceptors. However, the later decrease in RNA reversed above the control so that 60 s after the injection change in RNA was +5 +/- 10% of the control. Complete baroreceptor denervation showed a similar response on RNA in the vagotomized animals (+49 +/- 9 and +14 +/- 10% of the control at 20 and 60 s after the injection, respectively). In contrast, intravenous injection of capsaicin (6 +/- 1 microgram/kg) resulted in significant decreases in MBP (-19 +/- 11 mmHg) and HR (-9 +/- 4 beats/min). RNA at 20 s after the injection showed a unidirectional decrease by -16 +/- 7% of the control in animals with intact baroreceptors. These responses reversed above the control after cervical vagotomy. Thus, these data indicate that activation of C-fiber afferents in skeletal muscles by intra-arterial injection of capsaicin results in renal sympathoexcitation, and that the later sympathoinhibition is mediated by combined activation of systemic baroreceptors.

[Kappa-type opioid receptor in human placental membrane]

Since many opioid receptor preparations are heterogeneous systems containing multiple types of receptor, characterization of each type of the receptor is influenced by contamination with other types of receptor. Demonstrating kappa receptor proved more difficult owing to the ability of kappa ligands to interact with a number of receptor classes and to the lack of the homogeneous preparation. It has been reported that kappa ligands selectively bind to human placental membrane. To establish homogeneous kappa receptor preparation, the kappa binding to human placenta was characterized. The portion which was predominantly villus tissue was removed from freshly collected placenta, and the P3-membrane fraction was prepared. Kappa opioid agonist, such as 3H-Dynorphin A, 3H-ethylketocyclazocine and 3H-U-69593, bound to the human placental membrane fraction in a manner of single class of binding site (Bmax: approximately 40 fmol.mg-1 protein). In contrast, 3H-dihydromorphine, 3H-DAGO (mu agonist), 3H-DADLE (delta agonist) or 3H-SKF-10047 (sigma agonist) showed no binding activity. The specific binding of 3H-diprenorphine was displaced only by kappa-selective ligand (U-50488H, dynorphin, butorphanol). These results suggest that opioid binding in human placental membrane is specific for kappa opioid.

The effects of 24% paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) on hemodynamics, blood gases, plasma lactate and plasma catecholamines in dogs

The cause of death after ingestion of a large dose of paraquat is unclear. We investigated the cardiovascular effects of paraquat injection in 7 dogs that were anesthetized with urethane and alpha-chloralose and maintained on controlled ventilation. After control measurements, paraquat (20 mg/kg) was injected iv. Average concentrations of plasma paraquat were 128 micrograms/ml at 15 min (point 1) and 44 micrograms/ml at 4 hr. The average time of survival was 5.5 +/- 2.2 hr. Comparison was made of control values, 15 min (point 1), and 2.5 +/- 1.0 hr before death (point 2). Pulmonary capillary wedge pressure (+33%) and pulmonary vascular resistance (PVR) (+28%) increased, but no change occurred in mean arterial pressure (MAP) or cardiac output (CO) at 15 min. Mean arterial pressure (-50%) and cardiac output (-61%) decreased, while total vascular resistance (+56%) and PVR (+256%) were increased at point 2. Arterial pH decreased from 7.394 and 7.307 (point 1) to 7.143 (point 2). The concentration of plasma catecholamines and lactic acid increased significantly at both points 1 and 2. Renal, adrenal and myocardial tissues were studied by light and electron microscopy. The outstanding feature was early swelling of mitochondria and disruption of the contents in the presence of intact mitochondrial membrane.

Purification and characterization of a galactose-binding lectin from the skin mucus of the conger eel Conger myriaster

1. A galactose-binding lectin was purified from the skin mucus of the conger eel Conger myriaster by affinity chromatography and HPLC. 2. The lectin was a simple protein having the same two subunits with a mol. wt of 12,500 and a N-terminal amino acid of phenylalanine. 3. Electrofocusing suggested that the purified lectin was composed of several isolectins. 4. From the ultraviolet difference spectra attributable to tryptophanyl residues in the binding site, the binding constant of the lectin for D-galactose was estimated to be 5.3 x 10(3)/M.