A pressure-distribution sensor (PDS) for evaluation of lip functions

The purpose of this study was to develop and to test a pressure-distribution sensor (PDS) for evaluating lip functions. The PDS is fabricated as a disposable cartridge and is based on the principle of optical-pressure conversion used in tactile sensors of robot arms. Its advantages are in measuring sealing forces, contact area, and pressure-distribution patterns of the lips at maximum effort. We used the PDS to evaluate pressure-distribution patterns of long-face subjects with extremely large interlabial distances. The results suggest that the PDS is a useful device for evaluating lip sealing functions and their changes after orthodontic therapy or orthognathic surgery.

Resinous plate for permanent sternal splinting in patients with extracardiac conduits

During operations on patients with extracardiac conduits, sternal reapproximation occasionally results in critical compression of the conduit and serious deterioration in hemodynamic function. Permanent splinting of the sternum with a methyl methacrylate resinous plate provides an adequate substernal space for the extracardiac conduit.

Long-term time course of regional changes in cholinergic indices following transient ischemia in the spontaneously hypertensive rat brain

Using an animal model of forebrain ischemia in spontaneously hypertensive rats (SHR) by 3-h bilateral carotid occlusion, and various indices of the cerebral cholinergic system were assessed for periods up to 24 weeks. The lesions observed histologically in the hippocampus of SHR 2 weeks after ischemia were less severe than those in the frontal cortex. Marked elevation of acetylcholine concentration was transiently observed in the frontal cortex, hippocampus and thalamus + midbrain at 2 weeks, and in the striatum at 1-4 weeks after ischemia. Choline acetyltransferase activity remained unchanged in all regions throughout the experimental period except for a minimal decrease in the frontal cortex at 4 weeks. Choline esterase (ChE) activity was slightly decreased in the frontal cortex at 2-4 weeks after ischemia but recovered by 8 weeks. A decrease in the hippocampus was seen at 8 weeks. The B(max) for the M1-receptor was significantly reduced by 2 weeks in the frontal cortex and by 4 weeks in the hippocampus. Low B(max) values in both regions persisted through week 24. These delayed hippocampal changes in the ChE activity and M1-receptor in SHR were similar to those of the very much delayed changes in M1-receptor previously reported in the gerbil model for transient ischemia. In contrast, Wistar-Kyoto rats (WKY), used as normotensive controls, exhibited no histological or biochemical changes for up to 24 weeks. The difference between SHR and WKY may depend on the more severe cerebral blood flow depletion during carotid ligation in the former. The chronic state of SHR after the transient ischemia may be a useful pathophysiological model for human cerebral infarctions with hypertension.

Successful management of massive pulmonary tumor embolism from renal cell carcinoma

Renal cell carcinoma occasionally invades the inferior vena cava and rarely extends to the right atrium. However, despite the frequency of venous extension, it is unusual to recognize patients with massive pulmonary tumor embolus clinically. We describe a 60-year-old man who underwent pulmonary tumor embolectomy using cardiopulmonary bypass combined with profound hypothermia and intermittent low-flow perfusion. The patient is currently alive and well without implantation metastasis 6 months after the operation.

Expression of Cu,Zn-superoxide dismutase mRNA after cold and contusion injury in the rat brain

We analyzed the expression of Cu,Zn-superoxide dismutase (SOD) mRNA in both contusion and cold injury. Twenty-three rats were divided into 3 groups: a control group, a contusion group, and a cold injury group. Six hours after the injury, the rats were decapitated and the gray matter was resected from 3 portions: the core of the injured cortex, its periphery, and a distal portion on the non-lesion side. Based on the specific gravity of each sample, almost the same degree of edema developed in both injury groups. The mRNA expression in the cold injury group, however, significantly decreased in all portions. The extremely low temperature associated with cold injury is a possible cause of the decrease in Cu,Zn-SOD mRNA.

Meningiomas arising from the falcotentorial junction. Clinical features, neuroimaging studies, and surgical treatment

Meningiomas arising from the falcotentorial junction are extremely rare. The authors describe the clinical features, neuroimaging studies, and results of surgical treatment of meningiomas of the falcotentorial junction and clarify the characteristics of this lesion based on a review of the literature and seven patients treated at their institution. The most common symptoms resulted from intracranial hypertension. Upward-gaze palsy appeared in only one patient. Computerized tomography (CT) showed no specific findings, but there was no evidence of edema around the tumor. Magnetic resonance (MR) imaging revealed a round, smooth-bordered mass with a peritumoral rim, without edema, and showing marked contrast enhancement. The multiplanar capability of MR imaging delineated the relationship between the tumor and adjacent structures better than did CT. Detailed knowledge of the vascular structures, especially evidence of occlusion of the galenic venous system and the development of collateral venous channels, is critical for successful surgery; stereoscopic cerebral angiography is necessary to achieve this aim. The seven patients described developed five types of collateral venous channels: through the basal vein of Rosenthal to the petrosal vein, through the veins on the medial surface of the parietal and occipital lobes to the superior sagittal sinus, through superficial anastomotic veins, through veins of the posterior fossa to the transverse or straight sinus, and through the falcian veins to the superior sagittal sinus. The first three types mainly developed after occlusion of the galenic system. The tumors were removed through the occipital transtentorial approach with a large window at the posterior part of the falx. A favorable prognosis for patients undergoing surgical treatment of falcotentorial junction meningiomas can be expected if detailed neuroimaging studies and microsurgical techniques are used.

[The left-sided atrioventricular replacement of corrected transposition of the great arteries through a left thoracotomy]

In a 17-year-old female with dextrocardia and corrected transposition of the great arteries, whose VSD and PFO had been surgically closed through median sternotomy two years previously, the left-sided atrioventricular valve replacement was performed for its severe insufficiency. The left anterolateral thoracotomy was chosen to have good visual field and to prevent unnecessary dissection of the adhesion. The postoperative course was uneventful.

Long-term results of surgical treatment of intracardiac tumors. Effectiveness and limitation of surgical treatment

Twenty-five cases of intracardiac tumors were operated upon from 1975 through 1994. Twenty-four operative survivors were followed up. The follow-up period ranged from 2 months to 19 years with an average of 8 years. The histological diagnoses of the tumors were as follows: benign tumors 21 (myxoma 20, leiomyoma 1) and malignant tumors 4 (sarcoma 3, carcinoma 1). In 21 cases, tumors had cardiac origins, while there were four intracardiac tumors which had originated in other organs and extended transvenously to the intracardiac cavity (leiomyoma 1, sarcoma 2, carcinoma 1). The results of surgical treatment of intracardiac benign tumors were satisfactory, regardless of their origins and multiplicity, both in the short-term and in the long-term. On the other hand, the long term results for malignant intracardiac tumors were extremely poor, although their excision or resection had a beneficial effect on the hemodynamics in patients with congestive heart failure or cardiogenic shock.

[Pulsatile total cavopulmonary shunt for hypoplastic right heart syndrome with abnormal systemic venous return--a case report]

A pulsatile total cavopulmonary shunt was successfully performed on a 5-year-old girl with hypoplastic right heart syndrome associated with abnormal systemic venous return; at the same time, modified mitral valve replacement was performed for mitral regurgitation. The right atrium, tricuspid valve and right ventricle were all extremely dimunitive. The diameter of the tricuspid valve was 50% of normal and the volume of the right ventricle was 8.6% of normal. In addition, there were severe subpumonary stenosis, a restrictive ventricular septal defect (VSD) and an atrial septal defect (ASD). The bilateral superior venae cavae (SVCs) and the hepatic vein drained to the left atrium, and the inferior vena cava was infrahepatically interrupted with a hemiazygos connection to the left superior vena cava. At the operation, each SVC was anastomosed end-to-side to each branch of the pulmonary artery (PA). The restrictive ventricular septal defect and stenotic subpulmonary lesion were left. The diameter of the ASD was reduced from 12 mm to 7 mm. The main PA was neither divided nor banded. The pulsatile blood flow from the left heart to the PA was regurated by a native restrictive VSD and stenotic subpulmonary lesion, and that from the right heart via the ASD was limited by reducing the size of the ASD. These described anatomic arrangements produced adequate antegrade pulsatile flow in the PA, which might prevent the development of pulmonary arteriovenous fistulae and, besides permit transfer of drainage of the hepatic vein from the left to the right atrium via the ASD in future.

Superoxide scavenging activity in the extracellular space of the brain in forming edema

We carried out a time course study of cerebral superoxide scavenging activity using a modified microdialysis technique. Twelve cats were divided into two groups; six were the reperfusion injury models, and six were cold injury models. In the reperfusion injury model, dialysates were collected during 60 minutes of middle cerebral artery occlusion and at 300 minutes during reperfusion. In the cold injury model, dialysates were collected 240 minutes after the injury. Regional cerebral blood flow on the injured side decreased during occlusion in the reperfusion injury model and 60 minutes after injury in the cold injury model. In the reperfusion model, superoxide scavenging activity, as determined with electron spin resonance, increased in the first 30 minutes and decreased 300 and 330 minutes after occlusion. In the dialysate, albumin increased 180 minutes after cold injury, which may show the progress of vasogenic edema. An increase in water content was observed on the injured side of both models, and a correlation between water content and superoxide scavenging activity was found in the reperfusion injury model. By this technique, a method of detecting the alteration of superoxide scavenging activity in the extracellular space of the brain was established.

Experimental analysis of brain surface elastance in cats

Brain surface elastance, defined as the pressure needed to compress the cortex 3 mm, was measured using the ophthalmodynamometer in six cats using three burr holes (frontal, parietal, and occipital) on each side. An intracranial mass was then used to compress the right side for 3 hours, and cardiac arrest was induced after the mass was removed. Elastance was measured four times: before insertion of the mass, 10 and 70 minutes after removal of the mass, and 60 minutes after cardiac arrest. The results showed that: brain surface elastance does not change between sides, but varies among regions with the parietal region having the highest elastance; elastance increases after compression by an intracranial mass, but not after cardiac arrest; and stiff brain tends to restore poorly. Elastance is apparently increased by the formation of edema. Measuring brain elastance may be useful in predicting brain restoration subsequent to removal of mass lesions.

Induction of Cu,Zn-superoxide dismutase after cortical contusion injury during hypothermia

To determine the effect of hypothermia on superoxide injury after cerebral contusion, the induction of Cu,Zn-superoxide dismutase was examined 6 h after contusion in rats using Northern blotting. Cu,Zn-superoxide dismutase gene expression increased at the periphery of the contusion, which may indicate the severity of the superoxide stimulus. This increase was preserved after contusion under hypothermia, which may show that superoxide injury is still severe although brain edema is decreased.

[Target heart rate for exercise echocardiography]

The exercise stress test with a semi-supine position bicycle ergometer was evaluated in 10 normal subjects and five cardiac patients to define the appropriate target heart rate for exercise echocardiography. The normal healthy subjects were aged between 24 and 30 years, while the five patients with artificial aortic valves were aged between 13 and 54 years. The workload was continuously increased from 0 W to the maximum achieved workload at 20 W/min for normal subjects and 10 W/min for patients. Echocardiography was recorded every minute during the test procedure. End-diastolic and end-systolic dimensions were measured and ejection fraction was calculated. The ejection fraction at heart rates 50, 60, 70 and 80% of predicted maximum heart rate and at maximum workload were compared. Heart rates at the maximum workload for normal subjects were 76 to 94% (86.3 +/- 6.3%) of the maximum heart rate predicted from the age of the subjects and 70 to 102% (84.0 +/- 12.6%) for the patients. The largest election fraction values during exercise stress were obtained at 70% of the maximum predicted heart rate in normal subjects, and at 60% in the patients. The target heart rate for exercise echocardiography is 70% of the maximum calculated heart rate.

Superoxide scavenging activity in vitro and in the cerebral extracellular space measured by microdialysis

Using the electron spin resonance (ESR) spin-trapping method and a high molecular cut-off membrane, we measured the superoxide scavenging activity in dialysates obtained from microdialysis. The activity in the dialysates of the Cu,Zn-superoxide dismutase (SOD) solution and feline serum were measured in vitro, and the recovery rate was calculated to be 12.88 +/- 0.9% in Cu,Zn-SOD solution and 21.52 +/- 4.38 in feline serum, which was significantly different. This difference was believed to originate from the higher osmotic pressure due to proteins in the serum and substances other than Cu,Zn-SOD that acted as antioxidants in the serum. In an in vivo study, microdialysis probes were implanted into the cerebral hemispheres in 6 cats. The sequential changes of superoxide scavenging activity were measured for 16 h and during induced cardiac arrest. No significant difference was observed and the microdialysis technique itself did not seem to cause the significant alteration of the activity in the extracellular space, although at cardiac arrest, the activity varied widely. This method can be used to study the reaction against superoxide injury in further experiments involving brain insult.

Detection of endogenous albumin as an index of blood parenchymal border alteration

We used a microdialysis technique to establish a method to detect sequential changes in disruption of the blood parenchymal border. Twelve cats were divided into two groups; one group underwent occlusion of the middle cerebral artery for 60 minutes, the other a cold injury model. Microdialysis probes were implanted bilaterally into the white matter, and dialysates were collected successively at 30 minute intervals for 6 hours in the occlusion model and 4 hours in the cold injury model. Regional cerebral blood flow was measured simultaneously using the hydrogen clearance method. The water content of the white matter was measured using specific gravity. The proteins in the dialysate were analyzed using electrophoresis with silver stain, and, with densitometric analysis, the density of the 66.2 kDa band was quantified as albumin. The ratio of this density to the preoperative density was defined as the "albumin index." On the side of the lesion in the cold injury model, this index significantly increased 3 hours after the cold injury compared with the contralateral side, and a correlation between the water content and this index was observed. The albumin index was believed to indicate the severity of disruption of the blood parenchymal border.

Endogenous superoxide dismutase activity in reperfusion injuries

To elucidate the relationship between reperfusion injuries and free radicals, we monitored the endogenous superoxide dismutase (SOD) activity by intracerebral microdialysis. Six cats underwent a transient occlusion of the middle cerebral artery for 60 minutes after microdialysis probes were implanted bilaterally into the white matter under the ectosylvian gyrus. Dialysates were collected at 30 minute intervals over the course of 5 hours after reperfusion. The SOD activity of the dialysates was measured with electron spin resonance spectrometry. Regional cerebral blood flow was measured simultaneously and the water content of the white matter was assayed at the end of the experiment. After reperfusion, SOD activity increased significantly in the first 30 minutes compared with the preoperative value, and decreased over 4-4.5 hours and 4.5-5 hours in the occluded side. The water content in the occluded side was significantly higher than that in the contralateral side. The highest SOD activity during reperfusion and the water content in the occluded side seemed to correlate, although not significantly. A leakage of intracellular SOD or a reactive increase of SOD activity in response to the reperfusion injury are possible mechanisms of increase in extracellular SOD.