Comparison of extracellular enzymes of Fusobacterium necrophorum subsp. necrophorum and Fusobacterium necrophorum subsp. funduliforme

A total of 10 strains each of Fusobacterium necrophorum subsp. necrophorum and Fusobacterium necrophorum subsp. funduliforme were tested for the production of 13 extracellular enzymes. DNase, alkaline phosphatase, and lipase were predominantly associated with all the strains of F. necrophorum subsp. necrophorum, with DNase not detected in any of the strains of F. necrophorum subsp. funduliforme. In addition, the strains of F. necrophorum subsp. necrophorum were generally more hemolytic than those of F. necrophorum subsp. funduliforme. Lecithinase, beta-lactamase, elastase, hyaluronidase, chondroitin sulfatase, and coagulase were not detected in any of the strains. DNase may be used to differentiate between the two subspecies.

[Disseminated Trichosporon beigelii infection: report of nine cases and review]

Trichosporon beigelii (formerly called Trichosporon cutaneum) is an emerging pathogen of disseminated trichosporonosis in immunocompromised patients. We conducted postmortem microbiological examinations of lung aspirates and blood in the heart. T. beigelii was isolated from the samples of 7 (2.24%) of 313 patients. Five of 7 patients isolated were diagnosed as having trichosporonosis based on histochemical and clinical findings. The other two were considered as colonization. Immunohistochemical study using Cryptococcus neoformans-absorbed antiserum to T. beigelii was carried out on the sections of autopsied tissues with deep mycoses. The sections from seven patients were positively stained, which were formerly diagnosed as candidiasis and/or aspergillosis. Consequently, 9 patients had disseminated trichosporonosis caused by T. beigelii. In Japan, 43 patients including the present 9, 31 males and 12 females, aged 51 (range, 2-84), were reported in the literature. Thirty-seven (86%) patients had hematologic malignancy, and the majority of them revealed profound neutropenia due to cytotoxic chemotherapy. Thirty-eight (88%) patients died despite the anti-fungal chemotherapy including amphotericin B. New strategies for refractory disseminated trichosporonosis in immunocompromised patients is needed.

Ryanodine wastes oxygen consumption for Ca2+ handling in the dog heart. A new pathological heart model

Ryanodine (RYA) at a low concentration (several tens of nM) is known to selectively bind to Ca2+ release channels in sarcoplasmic reticulum (SR) and to fix them open. The present study was designed to investigate the effects of the selective change in Ca2+ release channel activity on cardiac mechanoenergetics as a model of Ca(2+)-leaky SR observed in pathological hearts. We analyzed the negative inotropic effect of RYA at a low concentration (up to 30 +/- 13 nM) on left ventricular (LV) mechanoenergetics using frameworks of LV Emax (a contractility index) and the myocardial oxygen consumption (LV VO2)-systolic pressure-volume area (PVA) (a measure of total mechanical energy) relation in 11 isolated, blood-perfused dog hearts. RYA significantly decreased Emax by 42%, whereas PVA-independent VO2 remained disproportionately high (93% of control). This oxygen-wasting effect of RYA was quite different from ordinary inotropic drugs, which alter Emax and PVA-independent VO2 proportionally. The present result suggests that RYA suppresses force generation of cardiac muscle for a given amount of total sequestered Ca2+ by SR in a similar way to myocardial ischemia and stunning. We speculate about the underlying mechanism that RYA makes SR leaky for Ca2+ and thereby wastes energy for Ca2+ handling by SR.

[An analysis of the status of surgical transfusion and a trial of maximum surgical blood order schedule (MSBOS) in Fukui Medical School Hospital]

To evaluate the present status of surgical transfusion during operations, we computed the amount of preoperative preparation and intraoperative use of blood. And we examined cross-match to transfusion ratio (C/T ratio) and maximum surgical blood order schedule (MSBOS) based on the statistical data in our hospital. The result revealed that too much blood was prepared in our hospital. The amount of prepared blood was 12,825 units of which 2,419 units were transfused (1 unit = 200 ml of whole blood). The mean C/T ratio was 5.30. And a trial of MSBOS revealed that we could save 70% of the blood presently prepared. We are sure that the introduction of T & S and MSBOS will lead to more efficient transfusion in our hospital.

An immunohistochemical study of neurofilament and microtubule-associated Tau protein in the enteric innervation in Hirschsprung's disease

The distribution and localization of neurofilament (NF) and microtubule-associated tau protein (Tau) in the colon from Hirschsprung's disease were examined by immunohistochemistry. Specimens of the normoganglionic, oligoganglionic, and aganglionic segments of colons from nine patients with Hirschsprung's disease were used in this study. Normal colon specimens obtained at the time of colostomy closure from two patients with anorectal malformations were also examined as controls. In normoganglionic segments, anti-NF-H and anti-NF-M immunoreactivity appeared within the nerve fibers of both the myenteric and submucosal plexuses. These findings were also observed in the oligoganglionic segments. In the aganglionic segment, hypertrophic nerve fascicules and the nerve fibers in circular muscle were positively stained with anti-NF-H and anti-NF-M antibodies. Anti-Tau staining appeared in the ganglion cell bodies of both myenteric and submucosal plexuses and in nerve fibers distributed among the circular muscles of the normal control colons, and the normoganglionic and oligoganglionic Hirschsprung's specimens. Nerve fibers in the circular muscle layer of aganglionic segments were also stained with anti-Tau serum, although the hypertrophic nerve fascicules in the intermuscular and submucosal layers did not stain. The so-called nerve fascicules distributed in the subserosal layer also did not stain with anti-Tau. These results suggest that Tau may be used as a specific marker to identify ganglion cells and intrinsic nerve fibers in colons affected by Hirschsprung's disease.

[Re-operation for total anomalous pulmonary venous connection twelve years after radical operation]

Thirty five-year-old man required reoperation, twelve years after radical operation of total anomalous pulmonary venous connection (Darling IIb type), because of the clinically apparent pulmonary venous obstruction. The stenosis of ASD was revealed by cineangiocardiography and echocardiography. The fibrous thickening of atrial septal wall and stenosis of ASD were found at the operation. Operating procedure consisted of the enlargement of ASD and cut-back of the atrial septal wall. Postoperative study showed no evidence of stenosis of pulmonary venous return. The patient was discharged well and returned to his job. Late postoperative pulmonary venous obstruction is of particular concern. Usually it occurs within the first few postoperative months. We reported this case because it is rare that pulmonary venous obstruction occurred twelve years after radical operation.

Production of transgenic rats using pregnant and pseudopregnant rats prepared at a breeding farm

We used pregnant and pseudopregnant Wistar-Imamichi rats, prepared at a breeding farm, for production of transgenic rats. The donor and recipient rats were transported to our facility for ova manipulation and embryo implantation, respectively. As a foreign gene, 1.9 kb of a hybrid gene was constructed with the rat renin promoter and chloramphenicol acetyltransferase-coding gene. Fertilized oocytes were collected from the donor and the foreign DNA was microinjected into the pronuclei of 539 oocytes by the method of Hochi. The manipulated oocytes were cultured to the 2-cell stage. One hundred seventeen 2-cell embryos were implanted in the recipient rats. Of 67 newborns, 55 rats grew up to be 3-week-old weanlings. Genomic DNA was extracted from the tail of these weanlings and examined by polymerase chain reaction analysis. Six transgenic rats were found to have been generated by the present method. In this way, transgenic rats were produced by an efficient combination of breeding farm utilization and laboratory research.

Myocardial mechanics and the Fenn effect determined from a cardiac muscle crossbridge model

A three-element cardiac muscle fibre model, utilising Huxley's sliding filament theory for the contractile element and coupled with parallel and series elastic components, was simulated to see if it were possible to predict the cardiac Fenn effect. The force/length energy (FLE) was computed in both isometric and isotonic contractions, as a function of muscle fibre length (preload) in the isometric case and afterload in the isotonic contraction case. Simulation results demonstrated that isotonic contractions produced a greater FLE than isometric contractions at every corresponding afterload, with the difference being equal to the work produced in the isotonic case, which is characteristic of the Fenn effect. The maximum energy utilisation was observed at maximum force isometric contractions, as has been experimentally observed in cardiac muscle. Changing the stiffness of the series elastic component did not change the Fenn-effect behaviour. Fenn-effect plots using crossbridge energy predictions showed behaviour similar to the FLE plots, but the FLE: crossbridge energy ratio declined with decreasing force even though the efficiency has been experimentally found to be constant.

[Brain protection on the aortic arch replacement--with deep hypothermic selective cerebral perfusion via right axillary artery]

Graft replacement was performed in the treatment of 31 patients with aneurysm involving the aortic arch from May, 1986 to December, 1992. Of the 31 patients, 16 had true aneurysm, 13 had aortic dissection and 2 had Annuloaortic ectasia. From May 1986 to May 1989, we did not have the policy about brain protection. Since June 1989, we performed the aortic arch surgery with deep hypothermic selective cerebral perfusion via right axillary artery and used open distal anastomosis technique. Besides, we exchanged the perfusion site to the ascending aorta when we finished the selective cerebral perfusion. In that way, brain complication rate was decreased from 57.1% to 11.7% and operative mortality was decreased from 85.7% to 29.1%.

GLUT2 expression and function in beta-cells of GK rats with NIDDM. Dissociation between reductions in glucose transport and glucose-stimulated insulin secretion

GLUT2 underexpression has been reported in the beta-cells of Zucker diabetic fatty rats and db/db mice, models of spontaneously occurring NIDDM with antecedent obesity. To determine whether the beta-cells of a nonobese rodent model of NIDDM exhibit the same abnormalities in GLUT2, we studied Goto-Kakizaki rats. In these mildly diabetic animals glucose-stimulated insulin secretion was reduced at all ages examined from 8 to 48 wk. In normal control Wistar rats, immunostainable GLUT2 was present on all insulin-positive cells in the pancreatic islets. Only 85% of beta-cells were GLUT2-positive in GK rats at 12 wk of age, and only 34% were positive at 48 wk of age. GLUT2 mRNA was 50% of normal in 12-wk-old GK rats. In the latter age-group, glucose-stimulated insulin secretion was only 28% of normal at a time when 85% of beta-cells were GLUT2-positive and initial 3-O-methyl-D-glucose transport rate was 77% of the control value. We conclude that although GLUT2 is underexpressed, neither the magnitude of the underexpression of GLUT2 nor of the reduction in GLUT2 transport function in islets of GK rats is sufficient by itself to explain the profound reduction in glucose-stimulated insulin secretion.

Multiple coronary artery dissections diagnosed in vivo in a pregnant woman

A 27-year-old, 37-weeks' primigravida survived an acute myocardial infarction. Coronary angiography 25 days after infarction demonstrated multiple dissections in the left coronary artery. She had no vascular risk factors or connective tissue disease. This is a rare case of spontaneous, multiple coronary artery dissections that were diagnosed by coronary angiography.

Characterization of the stable, acid-induced, molten globule-like state of staphylococcal nuclease

Titration of a salt-free solution of native staphylococcal nuclease by HCl leads to an unfolding transition in the vicinity of pH 4, as determined by near- and far-UV circular dichroism. At pH 2-3, the protein is substantially unfolded. The addition of further HCl results in a second transition, this one to a more structured species (the A state) with the properties of an expanded molten globule, namely substantial secondary structure, little or no tertiary structure, relatively compact size as determined by hydrodynamic radius, and the ability to bind the hydrophobic dye 1-anilino-8-naphthalene sulfonic acid. The addition of anions, in the form of neutral salts, to the acid-unfolded state at pH 2 also causes a transition leading to the A state. Fourier transform infrared analysis of the amide I band was used to compare the amount and type of secondary structure in the native and A states. A significant decrease in alpha-helix structure, with a corresponding increase in beta or extended structure, was observed in the A state, compared to the native state. A model to account for such compact denatured states is proposed.

Increased generation of reactive oxygen species in embryos cultured in vitro

Previous studies have suggested that oxygen toxicity is closely related to the developmental blockage of embryos cultured in vitro. In this study, to obtain an actual proof of the increase in production of reactive oxygen species within embryos, we have measured the level of H2O2 in individual embryos using a fluorimetric method. Mouse (ICR) pronuclear stage embryos from the oviducts were cultured for a specified time under various conditions in a medium to which 2',7'-dichlorodihydrofluorescin diacetate was added. After washing the embryos, the fluorescence emissions of the H2O2-dependent oxidative product in embryos were measured. The fluorescent emissions were lowest in embryos cultured under 5% O2 and highest under 40% O2 (5% < 20% < 40%), just the inverse of the culture efficacy. The fluorescence emmissions of embryos cultured in Ham's F-10, which contains hypoxanthine and transition metals such as Cu and Fe, were higher than those cultured in BWW and alpha MEM, which do not contain these components (alpha MEM < BWW < Ham's F-10; again this is the inverse of the culture efficacy). The fluorescence emissions of embryos increased with the time of the exposure to visible light. L-cysteine and thioredoxin, both of which have been shown to promote embryo development, decreased the fluorescence emissions of embryos. All of these results would provide direct evidence for the hypothesis that oxygen radicals are involved in the developmental blockage.

Physiological correlates of abnormal behaviors in magnesium-deficient rats

In order to elucidate the mechanism of behavioral alterations in magnesium-deficient rats, changes in the electroencephalogram (EEG) and electrocardiogram (ECG) were studied during auditory stimulation and correlated with the behavioral alterations. Weanling rats were fed either a Mg-deficient diet or a control synthetic diet for 2-3 weeks before the experiment. EEGs were recorded from the hippocampus and the sensorimotor and auditory cortices, and ECGs with a telemetry system. White noise with an intensity of 100 dB was given continuously to induce behavioral changes. The Mg-deficient rats developed consistent and graded behavioral changes in response to the stimulation, showing running-jumping behavior (stage 1), followed by tonic limb convulsion (stage 2) and finally by falling down on the floor (stage 3). The EEGs also showed consistent changes with spike activity, initiating in the hippocampus (stage 2) and then spreading to the neocortices bilaterally (stage 3). These findings indicate that the behavioral changes induced by auditory stimulation in the Mg-deficient rats are due to seizures arising in deeper brain structures, particularly in the limbic system, and projecting secondarily to the neocortices. The ECG changes, mainly consisting of marked bradyarrhythmia, occurred as early as the appearance of the EEG spikes, indicating that they were also related to the seizure. We conclude therefore that Mg deficiency in rats causes increased excitability of the central nervous system, resulting in seizures possibly originated in the limbic system, later developing secondary generalization, and also causing cardiac dysfunctions.

Effects of intraischemic hypothermia on cerebral damage in a model of reversible focal ischemia

Considerable evidence indicates that brain temperature during ischemia affects the extent and distribution of ischemic injury. However, only limited data have been presented concerning the influence of temperature on ischemic damage after reversible focal cerebral ischemia. Because focal ischemic events of this type resemble conditions observed in the clinic, studies were undertaken to examine the effects of mild and moderate hypothermia on the extent of cerebral infarction after focal neocortical ischemia. Under halothane anesthesia, the left middle cerebral artery and both carotid arteries were occluded reversibly for a period of 3 hours in adult Sprague-Dawley rats. The animals were killed 3 days later. Brain sections were stained with triphenyltetrazolium chloride and analyzed for infarction using a computerized image analysis system. Temporal muscle temperature and rectal temperature were monitored continuously. The following groups with different intraischemic temporal muscle temperatures were analyzed: 1) control, 35.8 to 36.2 degrees C; 2) mild hypothermia, 33.0 to 33.5 degrees C; and 3) moderate hypothermia, 27.5 to 29.2 degrees C. The volumes of infarction were 214.5 +/- 17.9, 166.5 +/- 6.8, and 108.2 +/- 5.9 mm3 (mean +/- SEM) for the control, mild hypothermia, and moderate hypothermia groups, respectively. These findings demonstrate that both mild and moderate hypothermia reduce the impact of temporary focal ischemia in Sprague-Dawley rats.

[Interaction of cardiovascular effect of calcium channel blocking drugs and those of inhalation anesthetics in humans]

The hemodynamics in the patients undergoing craniotomy was studied to evaluate the interaction of cardiovascular effects of calcium blocking drugs (nicardipine NCR or diltiazem DL) and those of inhalation anesthetics (0.6% isoflurane Iso or 0.9% sevoflurane Sevo). (Group I = NCR alone, Group II = NCR+Iso, Group III = NCR+Sevo, Group IV = DL alone, Group V = DL+Iso, Group VI = DL+Sevo) Anesthesia was maintained with neuroleptanesthesia (N2O 60%). A 30% reduction in systolic blood pressure was achieved and this was maintained for 60 minutes in each groups. The following effects were observed during induced hypotension. 1) Heart rate increased in the group I and II, but decreased in the group IV, V and VI. 2) Cardiac output increased in the group I and II, but significantly decreased in the group VI. 3) Systemic vascular resistance and left ventricular stroke work decreased in all the groups. 4) Pulmonary vascular resistance decreased slightly in all the groups. 5) Cardiac arrhythmias were observed in 4 cases of the group IV and VI. These results suggest that the presence of Iso or Sevo at low concentrations does not have a marked effect on the pharmacologic action of NCR or DL in humans.

Changing chemosusceptibility in the second-stage larvae of Toxocara canis by long-term incubation

Second-stage larvae of Toxocara canis were maintained in vitro for one year. Susceptibility of the larvae to drugs was evaluated by means of minimal larvicidal concentration (MLC) and larval bursting percentage. MLCs of citral and decanoic acid were almost constant throughout all stages of incubation. However, bursting percentage markedly varied within the first 20 weeks of incubation. Therefore, while larvae are available for use in the MLC assay at any stage of incubation, those beyond the first 20 weeks after incubation should be used for the bursting assay to obtain reproducible results.

Guanidine hydrochloride-induced folding of proteins

Guanidine hydrochloride (Gdn-HCl) is the most commonly used denaturant for proteins. Contrary to expectation, we found that Gdn-HCl at low concentrations refolds acid-unfolded apomyoglobin and cytochrome c, stabilizing the molten globule state, i.e. a compact denatured state with a significant amount of secondary structure, but substantially disordered tertiary structure. A further increase in Gdn-HCl concentration, above 1 M, caused co-operative unfolding of the molten globule state. Similar sequential folding and unfolding transitions were also observed at neutral pH with a synthetic amphiphilic peptide consisting of Lys and Leu residues, indicating the generality of the phenomenon. Although the Gdn-HCl-induced refolding and unfolding transitions were puzzling at first glance, we show that they are readily interpreted in terms of the differential action of Gdn-HCl. We also show that the comparison of the unfolding curves for the molten globule and native states provides a measure of the buried surface area upon formation of the molten globule state.

Cavernous hemangioma in the cavernous sinus

Cavernous hemangioma, a rare vascular hamartoma, in the cavernous sinus is described in this report. This case showed a slowly progressive course, which first involved the right optic nerve, followed by the left optic nerve, and then the right oculomotor, trochlear, abducens, and trigeminal nerves. Cavernous hemangioma should be suspected in the case of mass in the cavernous sinus with a very slowly progressive course. MRI is very useful to help diagnose this hemangioma.

Biochemical remodeling of collagen in the heart of spontaneously hypertensive rats--prominent increase in type V collagen

To determine how collagen is remodeled in the heart during the development of cardiac hypertrophy, the collagen concentration and the proportions of types I, III, and V collagen were analyzed in the hearts of 10-, 20-, 32-, and 40-week-old spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. The collagen concentration was calculated after the hydroxyproline content was measured and the proportions of types I, III, and V collagen were determined by non-interrupted SDS-polyacrylamide gel electrophoresis (SDS-PAGE). There was no significant difference between the collagen concentrations in 10-week-old SHR and WKY. At 20 weeks, the collagen concentration in the hearts of the SHR had decreased significantly (p < 0.01) when compared to that in the WKY, at 40 weeks, this concentration in SHR had increased significantly (p < 0.05) when compared to that in the WKY. Type V collagen in WKY increased with age and type I collagen in the 20- and 40-week-old WKY decreased significantly (p < 0.05) when compared to that in the 10-week-old WKY. However, the proportion of type I collagen in the 20-week-old WKY did not differ from that of the 40-week-old WKY. There was no significant difference between the proportions of the various types of collagen in 10-week-old SHR and those in age- and sex-matched WKY. However, the proportion of type V collagen in the 20- and 40-week-old SHR was significantly (p < 0.01) higher than that in age- and sex-matched WKY.(ABSTRACT TRUNCATED AT 250 WORDS)

Coupling between regional myocardial oxygen consumption and contraction under altered preload and afterload

OBJECTIVES

This study was designed to assess the relation between left ventricular regional myocardial oxygen consumption (VO2) and variables of regional myocardial contractile function under various loading conditions.

BACKGROUND

Although the relation between global VO2 and global ventricular function has been extensively studied, the relation between regional VO2 and regional myocardial contraction is not fully understood.

METHODS

Myocardial shortening (regional area shrinkage), regional work, regional total mechanical energy index and regional VO2 were measured under variously altered loading conditions in the isolated, blood-perfused dog left ventricle. Regional total mechanical energy per beat was quantified by wall tension-regional area area (TAA) by the analogy of left ventricular pressure-volume area. Left ventricular loading conditions were altered by changing end-diastolic volume and stroke volume with a servo pump as follows: 1) increased preload (increased end-diastolic volume and stroke volume at a constant ejection fraction), 2) decreased afterload (increased stroke volume at a constant end-diastolic volume), 3) increased preload and afterload (increased end-diastolic volume at a constant stroke volume), and 4) altered mode of contraction (ejecting vs. isovolumetric contractions).

RESULTS

During increased preload, all three variables correlated positively with regional VO2 (r = 0.78 to 1.00). During decreased afterload, the correlation was negative for area shrinkage (r = -0.65 to -0.91) and variable for regional work (r = -0.55 to 0.98) but positive and highly linear for TAA (r = 0.80 to 0.99). During increased preload and afterload, the correlation was again negative for area shrinkage (r = -0.77 to -0.97) but positive for regional work (r = 0.83 to 0.93) and TAA (r = 0.95 to 0.99). During altered mode of contraction, the correlation was insignificant for area shrinkage (r = 0.24 to 0.57) and moderate for regional work (r = 0.50 to 0.79), whereas again highly linear for TAA (r = 0.95 to 0.98). Thus, only TAA correlated closely with regional VO2 under any loading conditions. Furthermore, the slope and regional VO2 intercept of the regional VO2-TAA relation was remarkably consistent among the different hearts and loading conditions.

CONCLUSIONS

We conclude that there is a tight coupling between regional VO2 and regional total mechanical energy represented by TAA regardless of left ventricular afterload and preload conditions.

Isolated fracture-dislocation of the sacrum: case report

An unusual case of isolated fracture-dislocation of the sacrum is reported. A 19-year-old woman had a fracture-dislocation of S-1-2 combined with two longitudinal fractures of the sacrum, but no other pelvic fractures were identified. The possible mechanisms of fracture-dislocation of the sacrum are discussed. The fracture site was identified accurately on a CT scan. Pain relief was obtained by application of an external fixator. A mild neurologic deficit in the S-1 root distribution disappeared uneventfully.