[Mitral obstruction due to infective endocarditis: a case report]

Acute valvular obstruction caused by vegetation is a rare complication infective endocarditis. To our knowledge, only 9 cases and an autopsy case by Roberts have been reported since 1967. A 46-year-old man admitted with a chief complaint of pyrexia for 2 months duration. Within 24 hours of admission, the patient noticed of increased shortness of breath. Physical examination and the chest X-ray confirmed the pulmonary edema. An echocardiogram revealed a huge echogenic mass that was adherent to the mitral leaflet and obstructed the orifice completely. Soon after the patient fell into cardiogenic shock, an emergency mitral valve replacement was undertaken. At operation, multiple verrucae arising from the entire mitral leaflet was seen to occlude the orifice. The vegetation was excised and replaced with a # 25 Omnicarbon prosthesis. Postoperatively, the patient developed multiple organ failure caused by cardiogenic and septic shock which responded well to intensive medical treatment consisting of hemodialysis and continuous arteriovenous hemofiltration. Angiographically, a mycotic aneurysm in the left radial artery was found on the 18th postoperative day. After extirpation of the infective focuses, the postoperative course had stabilized. Mitral obstruction due to infective endocarditis is a fatal disease. Prompt diagnosis with echocardiogram and an emergency surgery should be undertaken to save the patient.

Inhibition of the high-affinity glutamate uptake system facilitates the massive potassium flux during cerebral ischaemia in vivo

During cerebral ischaemia, the extracellular concentration of K+ ([K+]e) increases abruptly to 50-60 mM following an initial slow increase to 6-10 mM. We have recently shown that the increase in [K+]e is significantly delayed by in situ administration of kynurenic acid, a broad spectrum antagonist of excitatory amino acids, suggesting that the catastrophic ionic fluxes occurring during ischaemia are initially mediated by EAA-coupled ion channels. In order to confirm further the role of EAAs, the changes in extracellular K+ ([K+]e) and glutamate ([Glu]e) during cerebral ischaemia were determined in the rat hippocampus by microdialysis in vivo, and the effect of dihydrokainate (DHKA), an inhibitor of the high-affinity uptake system of EAAs, was examined by in situ administration through the dialysis probe. DHKA induced a significant increase in baseline [Glu]e and facilitated the abrupt increase in [K+]e during cerebral ischaemia. These findings support the hypothesis that EAAs play a vital role in producing the rapid ionic shifts earlier during cerebral ischaemia.

Lactate accumulation following concussive brain injury: the role of ionic fluxes induced by excitatory amino acids

During the first few minutes following traumatic brain injury, cells are exposed to an indiscriminate release of glutamate from nerve terminals resulting in a massive ionic flux (e.g., K+ efflux) via stimulation of excitatory amino acid (EAA)-coupled ion channels. The present study was undertaken to elucidate the causal relationship between these ionic shifts and lactate accumulation in the injured brain, by examining the effects of ouabain (an inhibitor of Na+/K+-ATPase), Ba2+ (an inhibitor or non-energy-dependent glial K+ uptake) and kynurenic acid (KYN; a broad-spectrum EAA antagonist) on lactate accumulation. Two microdialysis probes were placed bilaterally in the rat parietal cortex. One was perfused with a test drug (1.0 mM ouabain, 2.0 mM Ba2+ or 10 mM KYN) and the other with Ringer's solution (control) for 30 min prior to injury. Following a 2.2-2.7 atm fluid-percussion injury, lactate levels in the dialysate increased (up to 116.6% above baseline) for the first 16 min and returned to baseline levels within 20 min after injury. This lactate accumulation was attenuated by preinjury administration of ouabain and KYN and was prolonged by Ba2+ administration. These findings indicate that lactate accumulations following concussive brain injury is a result of increased glycolysis which supports ion-pumping mechanisms, thereby, restoring the ionic balance which was disrupted by stimulation of EAA-coupled ion channels.

FR144420, a novel, slow, nitric oxide-releasing agent

We report that (+/-)-(E)-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexeneamide (FK409) decomposes and releases nitric oxide (NO) spontaneously in solution. (+/-)-N-[(E)-4-Ethyl-3-[(Z)-hydroxyimino]-5-nitro-3-hexen-1- yl]-3- pyridinecarboxamide (FR144420) was synthesized with the aim of discovering a compound with longer duration of effects in vivo, compared with FK409. FR144420, like FK409, released NO spontaneously in solution, but the amount of NO released from FR144420 during a 5-min incubation was half the amount from FK409. In addition, FR144420 spontaneously decomposed and generated nitrite, which is an oxidative metabolite of NO, at half the rate of FK409. In a vasorelaxant study with isolated rat aorta, FR144420 had a weaker potency than FK409 (EC50 = 54 and 8.1 nM, respectively). In in vivo studies, FR144420 decreased mean blood pressure immediately after intravenous and oral administration to conscious rats. The maximum hypotensive effects of FR144420 were less than those of FK409. However, the durations of FR144420-induced (i.v. and p.o.) hypotensive effects were longer than those of FK409-induced effects. In conclusion, FR144420 is more stable and releases NO more slowly in solution than does FK409. In in vivo experiments, FR144420 showed a longer duration of effects than FK409. FR144420 may be very useful for investigating the in vivo actions of NO.

Human B lymphocytes respond to Epstein-Barr virus with an increase in intracellular Ca2+ concentration

Early events in the infection of human B lymphocytes by Epstein-Barr virus (EBV) were examined by measuring calcium ion concentration from fluorescence with fura-2. Intracellular Ca ion concentration ([Ca2+]i) of B lymphocytes increased in response to EBV application. Three types of [Ca2+]i-increase were observed: (1) an early transient [Ca2+]i-increase; and (3) a slow [Ca2+]i-increase without the early transient [Ca2+]i-increase. The early transient increase was observed in the zero Ca2+ condition, but it was suppressed when cells were pretreated with ryanodine before exposure to the virus. The slow sustained [Ca2+]i increase was not observed in Ca(2+)-free extracellular conditions. These results suggest that the early transient [Ca2+]i increase is mediated by Ca2+ release from intracellular Ca storage sites, and the slow sustained [Ca2+]i increase is mediated by the Ca2+ influx through the plasma membrane. Virus receptors on the surface of B lymphocytes were stained with a fluorescence marker, rhodamine, and the capping process after EBV application was observed under a confocal microscope. The capping process and the localization of virus receptors were observed after EBV application. The time course of the capping process seems similar to that of the slow, sustained [Ca2+]i increase.

Control of persistent hemiballismus by chronic thalamic stimulation. Report of two cases

Persistent hemiballismus after stroke is often difficult to treat. The ballistic movement is sometimes so violent that progressive exhaustion results. The authors report two such cases, which were successfully treated by chronic thalamic stimulation. The lesions responsible for the ballistic movement in these patients were located near the subthalamic nucleus and in the putamen, respectively. The thalamic nucleus ventrolateralis and nucleus ventralis intermedius were stimulated with 0.2 to 0.3 msec pulses at 50 to 150 Hz and 4 to 7 V continuously during the day. Several weeks later, complete control of the hemiballismus was achieved during stimulation. The improvement was clearly not attributable to spontaneous recovery, because ballistic movement reappeared after termination of the stimulation. The stimulation has remained effective for more than 16 months in both cases without any serious complications. Chronic thalamic stimulation appears to be useful for controlling persistent hemiballismus, as it is for other involuntary movement disorders.

Effects of an indene-derivative, TN-871, on synaptic transmission in a sympathetic ganglion: presynaptic actions on neurotransmitter release

Intracellular recordings were made from bullfrog sympathetic ganglion cells to elucidate effects of 2-n-butyl-1-(4-methylpiperazinyl)-5,6-methylenedioxyindene.2 HCl (TN-871) on synaptic transmission. TN-871 at 30 nM augmented cholinergic nicotinic fast excitatory postsynaptic potentials (fast EPSPs), whereas the drug at 3 microM reversibly depressed them, without affecting acetylcholine-induced depolarizations. TN-871 did not affect active and passive electrical properties of the ganglion cells. The quantal analysis method was applied to the fast EPSPs in a 0.54 mM Ca2+/7.56 mM Mg2+ Ringer's solution. The mean quantal content was significantly increased by TN-871 at 30 nM but significantly decreased at 3 microM. TN-871 at 300 nM either increased or decreased the mean quantal content. The mean quantal size of the fast EPSPs was not changed by TN-871 at the concentrations examined. Fast EPSPs in a 0.99 mM Ca2+/4.86 mM Mg2+ Ringer's solution were not affected by nicardipine, but were inhibited in amplitude by omega-conotoxin in a concentration-dependent manner. It is likely that TN-871, in high concentrations, might block omega-conotoxin-sensitive N-type calcium channels in the presynaptic terminals. These results indicate that TN-871 modulates transmitter release from preganglionic nerve terminals without changing the postsynaptic sensitivity of the ganglion cells to ACh.

Ovarian carcinoid with severe constipation due to peptide YY production

We report a patient with primary trabecular carcinoid of the ovary with severe constipation probably due to peptide YY production by the tumor. A 43-year-old female had complained of severe constipation for several months and was found to have a left ovarian tumor. The surgically resected tumor was diagnosed as trabecular carcinoid by light microscopic examination. The carcinoid tumor cells were intensely and uniformly stained by the Grimelius technique. Immunohistochemically, the tumor cells were strongly positive for peptide YY, which has a strong inhibitory action on intestinal motility. The patient has been free from constipation since the removal of the tumor. The present case supports previously reported findings that not typical carcinoid syndrome but rather severe constipation accompanies primary trabecular carcinoid of the ovary, and that peptide YY is presumably the cause of the constipation.

Suppression of plasma-activated factor VII levels by warfarin therapy

To investigate the effect of warfarin treatment on the early phase of tissue factor-induced coagulation, we measured plasma-activated factor VII (factor VIIa) levels by a direct fluorogenic assay in 74 cardiovascular disease patients on long-term oral anticoagulation. We divided the patients into three groups based on the international normalized ratio (INR). In the patients with INR ranges of < 1.7 and 1.7 to 2.5, factor VIIa levels were 42% and 61% lower, respectively, than in age- and sex-matched controls. Factor VII coagulant activity (factor VIIc), factor VII antigen (factor VIIag), protein C, and factor X levels were also reduced to a similar extent in both groups. However, in patients with an INR > 2.5, the factor VIIa level was not decreased compared with that at an INR of 1.7 to 2.5, although the factor VIIc, factor VIIag, factor X, and protein C levels were all decreased further. Although the precise relation between the reduction of factor VIIa levels and the increase of INR requires appropriately designed long-term clinical trials, our data suggest that an INR range of 1.7 to 2.5 is sufficient for the suppression of factor VIIa. During the long-term follow-up of three patients with congenital antithrombin III or protein C deficiency, the factor VIIa level was more responsive to changes in the warfarin dose than the INR, and there were generally no corresponding changes of the thrombin-antithrombin III complex (TAT) level. However, one patient showed a transient marked increase of factor VIIa during the discontinuation of warfarin that was accompanied by an increase in TAT. Based on these findings, factor VIIa could be useful for monitoring both hypercoagulable and hypocoagulable states.

Temporal thresholds of reperfusion in the middle cerebral artery occlusion model in rats

In this study, the middle cerebral artery (MCA) of adult male Sprague-Dawley rats was occluded by the modified Koizumi method to determine the temporal thresholds of reperfusion for the treatment of cerebral embolism. Regional cerebral blood flow (rCBF) and pathological findings were measured at 1 and 2 h of ischemia and after 24 h and 7 days of reperfusion following 1 or 2 h of ischemia. rCBF was decreased the most (less than 10% of control CBF) in the parietal cortex (Pcor) and the lateral caudoputamen (Lcp) at both 1 and 2 h of ischemia. There was no significant difference in rCBF in these areas between the 2 ischemic groups. The 2 h ischemia group clearly showed infarction in the area perfused by the middle cerebral artery (including the Pcor and Lcp) after 24 h and 7 days of reperfusion, while the 1 h ischemia group showed only slight infarction. These findings suggest that temporal thresholds of reperfusion in this model exist between 1 and 2 h of ischemia, and that rCBF levels during ischemia and the duration of ischemia are the most important factors in producing brain infarction.

[A case of traumatic aneurysm of the thoracic aorta with severe chronic compression of the trachea]

A case of successfully treated traumatic aneurysm of the thoracic aorta with severe major air way compression was reported. A 38-year-old man, who had a history of blunt chest trauma in a traffic accident twenty years ago, complained of asthma-like coughing chest CT scan and angiogram showed a saccular aneurysm of desending aorta compressing the isthmus of the trachea and the esophagus severely. Resection of the aneurysm and prosthetic graft replacement was undertaken successfully with the aid of F-F bypass. The trachea and the esophagus were well decompressed and the patient recovered well with no complaints.

[Early diagnosis and detection of successful reperfusion by mitochondrial-AST/soluble-AST ratio after acute myocardial infarction]

The change of mitochondria aspartate aminotransferase (m-AST)/soluble-AST (s-AST) ratio was examined in 22 cases of acute myocardial infarction (AMI). The m-AST/s-AST was 40.8 +/- 18.9% at admission to a hospital (2.9 +/- 1.6h). The m-AST/s-AST decreased to normal value rapidly after peak and then increased again gradually. The decrease ratio of m-AST/s-AST per minute at early stage of 8 cases, who were succeeded to reperfusion, was 0.28 +/- 0.20%, and that was significantly higher than of conventionally treated 7 cases and non-reperfused 7 cases (0.11 +/- 0.07%). These results indicated that (1) m-AST/s-AST may be an excellent indicator for AMI in early stage. (2) The decrease ratio of m-AST/s-AST would predict whether reperfusion is successful or not at an earlier stage of AMI.

[Clinical statistics on patients operated at the Department of Urology, Kaizuka Municipal Hospital during ten years (from 1983 to 1993)]

A statistic survey was made on the patients undergoing operations between July, 1983 and June, 1993. The total number of patients was 1780, comprising 1469 males and 311 females. The most frequent organ was the prostate with 526 cases (29.6%), followed by 415 (23.3%) penile and scrotum cases, and 290 (16.3%) bladder cases. Major operations were transurethral resection of prostate (418 cases) and bladder tumor (191 cases).

Increased binding activity of measles virus to monkey red blood cells after long-term passage in Vero cell cultures

Recent field isolates of measles virus (MV) obtained by using B95-8 cells have been reported not to agglutinate African green monkey red blood cells (AGM-RBC). Vero cell-adapted, plaque-forming strains derived from three field isolates at the third passage in Vero cell cultures (T8Ve-3, T11Ve-3 and N13Ve-3) also exhibited markedly decreased binding activity, as determined by infectivity-absorption and haemadsorption tests. On the other hand, binding activity of the respective strains at the twentieth passage (T8Ve-20, T11Ve-20 and N13Ve-20) increased to practically the same level as that of the Edmonston strain, a standard strain of MV passaged long-term. A membrane immunofluorescence test revealed that the decreased binding activity to AGM-RBC of T8Ve-3, T11Ve-3 and N13Ve-3 was not due to decreased expression of the haemagglutinin (H) protein on the cell surface. The deduced amino acid sequence of the H protein synthesized in T11Ve-3-infected cells was identical to that in T11Ve-20-infected cells, although a single amino acid alteration was observed when T8Ve-3 was compared with T8Ve-20. Similarly, approximately half of the N13Ve-20-infected cells synthesized an H protein identical to that produced in N13Ve-3-infected cells, and nevertheless, exhibited markedly increased haemadsorption. The present results suggest that a viral protein(s) other than the H protein contributed to the binding activity of MV to AGM-RBC.

Oxygen sensors in vascular smooth muscle

Inhibition or activation of cellular function due to acute decreases in PO2 can be considered in terms of two different processes: 1) a sensor that monitors PO2 decreases and 2) transduction systems directed from the O2 sensor to reactions that control cellular function. We used the norepinephrine-contracted aortic smooth muscle model to study the nature of the O2 sensor and transduction system during decreased PO2-evoked relaxations. The phosphorylation potential, a measurement of kinetic energy required for ATP hydrolysis, was decreased to 30% of control at the onset of relaxation and progressively fell as muscle relaxed. The free inorganic phosphate intracellular concentration ([Pi]) was experimentally increased approximately 0.6 mM during transients that followed a rapid decrease in PO2. Relaxations to 80% of maximal force were more rapid under conditions of an augmented [Pi] than in control rings, and they occurred at a higher phosphocreatine concentration and phosphocreatine-to-free creatine ratio but at the same phosphorylation potential. Results support the operation of a cytochrome aa3 O2 sensor in the mechanism of decreased PO2-evoked relaxations and implicate an increase in [Pi] and a decrease in kinetic energy in the transduction mechanism directed at rate-limiting reactions that control force.

[The clinical significance of interleukin-6 as an inflammatory marker (the studies in patients with open heart surgery)]

We analyzed serum levels of interleukin-6 (IL-6) and seven acute phase proteins in CRP positive samples and in patients with open heart surgery. The concentrations of serum IL-6 were not correlated with other acute phase proteins in CRP positive samples. However, IL-6 were in inverse correlation with CRP, AAG, AAT and CER in patients with open heart surgery. These discrepancies were due to the differences in response time of each acute phase protein after the start of inflammation. Responses of acute phase proteins after open heart surgery were investigated from hour to hour. IL-6 increased rather rapidly than other acute phase proteins, and increases of CRP, TRF, AAT, AAG, CER, HAP and AMG followed. The time reached the peak were IL-6, CRP, TRF, AAT, AMG, AAG, HAP reached the peak in that order. IL-6 constantly increased seven hours earlier, and reached at maximum values forty three hours earlier than CRP in each case. The measurement of serum concentration of IL-6 may be useful for early detection of acute inflammation.

Persistent absence of auditory brainstem responses with preserved hearing and recovery from a prolonged comatose state

A patient with hypertensive intracerebellar haemorrhage, who recovered from impending tonsillar herniation with emergency haematoma evacuation, showed persistent absence of auditory brainstem responses. The patient demonstrated a preserved stapedius reflex and hearing after recovery, indicating that the auditory brainstem pathway was not completely disrupted. We suggest that the loss of the auditory brainstem response (ABR) could be accounted for by impulse asynchrony along the auditory brainstem pathway. The existence of such a case implies that persistent absence of the ABR is not always indicative of irreversible brainstem damage and a poor outcome following severe brain injury.