Micro-angiographical studies of the medullary venous system of the cerebral hemisphere

In order to identify the zones of convergence of the medullary veins of the cerebral white matter, gelatin-mixed barium sulfate was injected into normal brains at autopsy. A catheter was inserted into the internal jugular veins or the carotid and vertebral arteries. Serial soft tissue roentgenograms of whole brains and brain slices were used to determine the zones of convergence. The deep med-ullary veins had four zones of covergence before draining into the subependymal veins: the first (superficial), second (candelabra), third (palmate) and fourth (subependymal). The zones of various convergence within the white matter were due to the crossing of nerve fiber tracts (e.g. the pes of the corona radiata, the radiation of the corpus callosum, the superior occipitofrontal fasciculus, the tapetum and the sagittal strata). Similar but less conspicuous information about the parenchymal arteries was observed in the arterial injection studies. These results suggest that micro-angiographical studies of the medullary veins of the cerebral white matter provide detailed information on veno-architecture and convergence zones. This information may help in understanding the pathogenesis of medullary venous malformations.     

Corticostriatal and corticosubthalamic input zones from the presupplementary motor area in the macaque monkey: comparison with the input zones from the supplementary motor area

The presupplementary motor area (pre-SMA) is a cortical motor-related area which lies in the medial wall of the frontal lobe, immediately anterior to the supplementary motor area (SMA). This area has been considered to participate in the control of complex forelimb movements in a way different from the SMA. In an attempt to analyze the patterns of projections from the pre-SMA to the basal ganglia, we examined the distributions of pre-SMA inputs in the striatum and the subthalamic nucleus and compared them with the SMA input distributions. To detect morphologically the terminal fields from the pre-SMA and the forelimb region of the SMA, anterograde tracers were injected into such areas that had been identified electrophysiologically in the macaque monkey. Corticostriatal inputs from the pre-SMA were distributed mainly in the striatal cell bridges connecting the rostral aspects of the caudate nucleus and the putamen, as well as in their neighboring striatal portions. These input zones were located, with no substantial overlap, rostral to corticostriatal input zones from the SMA forelimb region. Corticosubthalamic input zones from the pre-SMA were almost localized in the medial aspect of the nucleus, where corticosubthalamic inputs from the SMA forelimb region were also distributed predominantly. However, the major terminal fields from the pre-SMA were centered ventrally to those from the SMA. The present results indicate that the corticostriatal and corticosubthalamic input zones from the pre-SMA appear to be segregated from the SMA-derived input zones. This implies the possibility of parallel processing of motor information from the pre-SMA and SMA in the cortico-basal ganglia circuit.     

Striatal perfusion of indomethacin attenuates dopamine increase in immature rat brain exposed to anoxia: an in vivo microdialysis study

Using in vivo microdialysis and HPLC, we examined the effects of indomethacin on extracellular dopamine (DA) in the striatum of immature rats submitted to anoxia. Rat pups in two indomethacin groups received intrastriatal perfusion of either 1 mM or 5 mM indomethacin throughout the experiment. The DA level reached 1185+/-400% of the basal level during anoxia; in contrast, the peak levels of DA were only 307+/-63%, 153+/-35% in indomethacin groups (p<0.05). We consider that this suppression would be one of the mechanisms of the protective effect of indomethacin on hypoxic ischemic encephalopathy.     

Multilocular thymic cyst associated with follicular hyperplasia: clinicopathologic study of 4 resected cases

We report here 4 cases of multilocular thymic cysts (MTCs) with reactive lymphoid follicular hyperplasia. They were admitted to our hospital to examine anterior mediastinal masses demonstrated on chest computed tomographic scans. Three patients presented high-grade intermittent fever, and 2 patients were associated with Sjogren syndrome with elevated serum antinuclear antibody levels. All patients were subjected to extended thymectomy. Interestingly, their fever disappeared immediately after surgery. Histologically, the lesions were characterized by several cystic spaces separated by various thick walls with dense lymphoid tissue containing large reactive germinal centers. The inner cyst walls were lined by flattened cuboidal epithelia in some portions. Columnar epithelia with focal cilia were partially observed in 2 cases. These pathological findings led to a diagnosis of MTCs that were thought to result from cystic transformation of medullary duct derivatives by acquired inflammatory processes. The pathological findings, together with clinical courses of our cases, suggest that inflammation accompanied by autoimmune diseases may play, in part, an important role in the development of MTCs.     

An energy-dependent step in aminoglycoside ototoxicity: prevention of gentamicin ototoxicity during reduced endolymphatic potential

Guinea pigs received a bolus of gentamicin (10 mM for 5 min) by perilymphatic perfusion which normally led to an irreversible loss of the cochlear microphonic potential (CM). Various experimental conditions that reduced the endolymphatic potential (EP) were then superimposed on the gentamicin application. Reversible reductions in EP (and, concomitantly, in CM) were induced by asphyxia (3 min), intravenous furosemide (50 mg/kg), and perilymphatic perfusion of aminooxyacetic acid (10 mM). When the administration of gentamicin was initiated at the time of maximal EP reduction the usual irreversible gentamicin-induced decline of CM was prevented. The results indicate that a metabolic process is essential in the expression of gentamicin toxicity. The data are consistent with the inhibition of an energy-dependent transport of the aminoglycoside. Alternatively, the data are also compatible with the hypothesis that entry of gentamicin into hair cells is prevented by a reduction in their transmembrane electrical potential.     

Arterial embolization as preoperative treatment for pulmonary aspergillosis with hemoptysis

Pulmonary aspergillosis associated with old tuberculosis is generally resistant to treatment. Thus, if patients are treated only with conservative therapy, their condition continues to deteriorate due to repetitive hemoptysis, and may even become critical. Surgical treatment is required for these patients; however, it is extremely difficult to resect the lesion due to severe adhesions to the chest wall and vascular proliferation surrounding the lesion. We performed preoperative arterial embolization, achieving good results in three patients with hemoptysis caused by pulmonary aspergillosis. The feeding arteries were embolized using microcoils and/or gelatin sponges, and a lobectomy was safely carried out in all patients. We concluded that preoperative arterial embolization is a safe and effective technique to prevent massive hemorrhage occurring at the time of surgery. This work was presented at the 11th Annual Meeting of the Japanese Association for Chest Surgery, held in Kyoto, Japan, May 13–14, 1994     

Thoracoscopic closure of a congenital partial pericardial defect

We describe our technique for performing direct thoracoscopic closure of a congenital partial pericardial defect, which was successfully employed in a 15-year-old boy. This is the first such report of a procedure that is noninvasive and may therefore become the treatment of choice for patients with a small congenital pericardial defect.     

Extracorporeal shock wave lithotripsy--difficulties in ESWL

At Kanbara Hospital, 187 patients with urolithiasis have been treated by extracorporeal shock-wave lithotripsy (ESWL) since the first ESWL treatment in December, 1986. Some cases in which ESWL could not be performed easily were experienced. These difficulties were analyzed retrospectively and some problems in the ESWL treatment are discussed.     

Human middle cerebral artery flow velocity during controlled hypotension combined with hemodilution-transcranial Doppler study

STUDY OBJECTIVE: To evaluate the effects of controlled hypotension combined with hemodilution on human middle cerebral artery flow velocity (Vmca) by transcranial Doppler ultrasonography. DESIGN: Randomized prospective study. SETTING: Inpatient surgery at Nagasaki Rosai Hospital. PATIENTS: Thirty American Society of Anesthesiologists physical status I and II patients scheduled for total hip arthroplasty. INTERVENTIONS: Anesthesia was maintained with nitrous oxide-oxygen (N(2)O-O(2)) and sevoflurane during normocapnia. Hemodilution was carried out after induction of anesthesia, in which blood was withdrawn then replaced with the same amount of hydroxyethyl starch to achieve a final hematocrit level of 32% (group A = mild hemodilution group, N = 15) or 24% (group B = moderate hemodilution group, N = 15). In both groups, controlled hypotension was induced with prostaglandin E(1) to maintain mean arterial pressure at approximately 55 mm Hg for 80 minutes. MEASUREMENTS AND MAIN RESULTS: Vmca and blood gas were measured before hemodilution, after hemodilution, 80 minutes after starting hypotension, and 60 minutes after recovery from hypotension. Vmca significantly increased in group A (+122%) and group B (+156%) after each hemodilution. In group B, Vmca was significantly greater than baseline values at 80 minutes after starting hypotension (+135%) and 60 minutes after recovery from hypotension (+140%). CONCLUSION: The combination of moderate hemodilution, such as hematocrit value of 24%, and prostaglandin E(1)-induced hypotension would not impair middle cerebral artery flow during sevoflurane-N(2)O-O(2) anesthesia during normocapnia.