Biomedical subjects
Publications and source records attributed to K Ebina.
A flexible aneurysm clip applier with a small spindle-shaped head was manufactured. It is useful for aneurysmal clipping through a narrow space and the clip can be set in various directions due to its flexibility.
We describe nine children with antibiotic-associated hemorrhagic colitis without Clostridium difficile toxin. The onset was usually sudden, with severe hematochezia and abdominal cramps. The illness quickly resolved and required no specific treatment except discontinuation of the implicated antibiotic. Early proctosigmoidoscopy was a useful diagnostic adjunct. It appears that antibiotic-associated hemorrhagic colitis is a distinct entity rather than a variant of antibiotic-associated colitis in children.
Acoustic neurinomas containing cystic parts are fairly common, but it is extremely rare for acoustic neurinomas to be mainly composed of cysts. So far, we have encountered three such cases. We studied these cases retrospectively to correlate their characteristic clinical symptoms and their respective pathological findings. Referring to reviews of the relevant literature and our three cases, we would like to discuss the possible mechanism of cyst formation and clinical symptoms. Compared with the patients with ordinary acoustic neurinomas, the patients in our three cases and in some cases in the literature have some distinct and possibly common clinical features. First of all, in spite of the cysts being large, hearing loss was less severe. Secondly, sudden onset of headache and hearing loss were frequently experienced, probably due to intratumoral hemorrhages. Thirdly, intratumoral hemorrhages with niveau formations were frequently able to be identified on CT or MRI scannings. Histologically, our three cases revealed lots of abnormal sinusoid or telangiectasis vessels. Small hemorrhages, hemosiderin deposits and hemosiderin-containing phagocytes were also more abundant than in solid-type neurinomas. The exact mechanism of the formation of these cysts is still controversial. Our hypotheses concerning the probable causes of cyst formation are presented in this study. In our three cases. the most distinct finding was the presence of abundant abnormal sinusoid or telangiectasis-like vessels. We suggest therefore that, in these cases, repeated small hemorrhages from these abnormal vessels, along with subsequent intratumoral changes, are the most probable cause of the formation of these cysts.
The nucleotide sequence of a cDNA encoding Asp-hemolysin from Aspergillus fumigatus was clarified. The deduced amino acid sequence was shown to contain a set of negatively charged domains similar to portions of the cysteine-rich sequence in the ligand-binding domain of LDL-receptor. A potential signal sequence was also identified in the N-terminal domain of the deduced amino acid sequence.
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We treated three children aged 10, 11 and 13 years with actively bleeding ulcers using local endoscopic injection of pure ethanol. Ethanol was injected into several sites around a visible vessel with or without bleeding. Haemostasis following ethanol injection therapy was confirmed by endoscopy performed the day after treatment. No rebleeding was observed. There were no complications related to the procedure. Injection therapy is technically simple and inexpensive. Conclusion Our results suggest that endoscopic ethanol injection is safe and may be the treatment of choice for control of bleeding from peptic ulcers in children.
The localization and ontogenic changes in the gene expression for phosphatase inhibitor-1 (I-1) were analyzed by in situ hybridization histochemistry, and they were compared with those for three catalytic subunits of protein phosphatase type 1 (PP-1). At the adult stage, intense expression signals for I-1 were detected in the hippocampal formation, piriform cortex, claustrum, dorsal endopiriform cortex, suprachiasmatic nucleus, choroid plexus, arachnoid membrane, and pineal body. Moderate expression signals for I-1 were observed in the olfactory neuronal layers, caudate putamen, layers II-IV, and VI of the neocortex, and cerebellar granule cells, whereas the expression levels were low in the thalamus, cerebellar Purkinje cells, and brain stem nuclei. Although the expression levels for the three PP-1 mRNAs varied notably in various brain regions, a relatively high and parallel expression of I-1 and PP-1 mRNAs was found in most regions of the forebrain. However, the dissociation in the expression levels between I-1 and PP-1 mRNAs was found in several loci: the laminar expression of I-1 mRNA versus the homogeneous expression of PP-1 mRNAs in the cerebral cortex; low levels of expression of I-1 mRNA versus relatively high expression of PP-1 mRNAs in the brain stem nuclei; high expression of I-1 mRNA in the arachnoid membrane versus low expression of PP-1 mRNAs in it. The unparallel expression was also seen in embryonic brain: No significant expression of I-1 mRNA versus substantial expression of PP-1 mRNAs in the ventricular zone and cerebellar external granular layer; transiently high expression of I-1 mRNA in developing thalamus versus constantly moderate to low expression of PP-1 mRNAs there. These findings suggest that I-1 may play some discrete roles independent of the regulation of PP-1 in certain regions and developing stages of the brain.
By in situ hybridization histochemistry, we have re-examined the ontogeny of the gene expression of mRNA encoding the dopamine- and cyclic AMP-regulated phosphoprotein with a molecular weight of 32,000, termed DARPP-32. On E13 and E15, weak expression signals were detected in the mantle zones and ventricular germinal zones of the fore-, mid-, hind-brain, and spinal cord. In the caudate putamen, the expression signals were first visible at its lateral margin on E15. The ventrolateral region of the caudate putamen expressed the gene intensely, while its ventricular germinal zone expressed it weakly on E18-20. Thereafter, the mRNA for DARPP-32 were expressed over the entire caudate putamen in patchy patterns. After birth, the expression levels in the caudate putamen increased markedly, with the majority of the neurons in the caudate putamen expressing the gene intensely on P7 and thereafter. In addition to the caudate putamen, expression signals were detected, albeit faintly, in the olfactory bulb, cortical plate, hippocampal pyramidal cell layer, and their ventricular zones on E18-20. The olfactory tubercle and medial habenular nucleus expressed the gene at slightly higher levels. In the cerebellum, the Purkinje cells showed progressively increasing gene expression from E20 to P7, whereas the external granule cell layer expressed the gene weakly. The ontogeny of the gene expression is largely consistent with previous immunohistochemical findings by other authors. Furthermore, the present finding suggests that DARPP-32 is involved in the regulation of the mitosis-related dephosphorylation by protein phosphatase 1 in the neuroepithelium.
Primary central nervous system (CNS) involvement of non-Hodgkin's lymphoma is uncommon and a vast majority of reported cases are of B-cell origin. We present a 52-year-old woman with primary peripheral T-cell lymphoma of the brain. Immunostaining of paraffin-embedded sections proved tumor cells to be positive for T-cell markers MT1 and UCHL1, and negative for B-cell markers MB1, and 4KB5. Radiotherapy combined with steroid therapy rendered neurologic recovery and complete tumor remission confirmed by computed tomography and magnetic resonance imaging. From a review of documented 19 cases of primary CNS T-cell lymphoma including the present case, this disease is characterized by poor prognosis among CNS lymphomas.
We have developed a new coating material for cerebral aneurysms consisting of cellulose. The possible usefulness of this ethyl cellulose-ethyl acetate solution ("Liquid cellulose") as a coating material was evaluated as follows: 1) The liquid cellulose (ethyl cellulose concentration, 10%; degree of polymerization, 100) and Biobond had pHs of 7.35 and 3.16, and viscosities of 1,385 and 626 cp, respectively. The properties of the coat (N = 30, M +/- SD) of the liquid cellulose and Biobond at a cast coat thickness of 254 microns were as follows: coat thickness after drying (microns), 17.8 +/- 2.8 and 109.8 +/- 44.2; coat formation time (sec), 62 and 1,800; strength of the coat (gm), 432.3 +/- 51.4 and 8.0 +/- 5.6; strength index (kg/cm2), 572.8 +/- 84.7 and 2.4 +/- 1.8; and elongation index (%), 14.8 +/- 3.5 and 705 +/- 188.8, respectively. The coat using liquid cellulose was more physiological and far stronger. It was also more readily manipulated during the operation than Biobond. 2) The liquid cellulose showed excellent adhesiveness when applied to the vascular wall. Sequential histological observations for 12 months showed that the liquid cellulose remained stable without histotoxicity or cracks in the coat. These results indicate the potential usefulness of this agent for reinforcing the vascular wall.
The pathogenesis remains unknown in the majority of patients with precocious puberty, and yet infrequently such causative cerebral lesions as hypothalamic hamartomas are associated with sexual precocity. We reported a rare case of suprasellar arachnoid cyst in an infant presenting with precocious puberty, which eventually disappeared after a cyst-peritoneal shunt. It was believed that the mass effect of the arachnoid cyst upon the hypothalamus was, at least in part, responsible for development of precocious puberty. The role of surgical decompression of the cyst was also discussed. A one-year-old girl was admitted to the hospital for evaluation of genital bleeding which had persisted on and off for two months. The height, 80cm, and the weight, 12.4kg, exceeded by far the two standard deviations from the mean level of the normal population. In addition she had the development of breast tissue as classified Tanner's Stage II, and both pubic and axillary hair. The bone age by skeletal survey of the hand was rated as 3 years. Endocrinological examination showed that serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol had increased for her age, to levels equivalent to those for females at puberty. An LH-RH test revealed an excessive LH reaction. There were no definite neurological deficits. CT and MRI demonstrated the presence of a large arachnoid cyst involving the suprasellar region as well as the right middle and posterior fossa. After the patient underwent a cyst-peritoneal shunt, the cyst decreased in size and such symptoms as genital bleeding and breast growth disappeared. Serum levels of her LH and FSH also significantly decreased.(ABSTRACT TRUNCATED AT 250 WORDS)
Two cases of a programmable pressure valve trouble are reported. Case #1 was that of a 49-year-old male who had received a ventriculoperitoneal shunt (VPS) using a Sophy programmable pressure valve (Model S3) after the removal of the fourth ventricle ependymoma. After the VPS, the patient went through several episodes of complaining of headache due to the spontaneous movement of the rotor from the high pressure position to the medium or low pressure position. The symptom had disappeared after exchanging the valve for a new one and by setting the valve pressure at high. Examination of the removed valve revealed that the bending-degree of the spring tip was insufficient, and that the opening pressures at the medium and high pressure positions were both lower than the desired range. Case #2 was that of a 62-year-old female who had received a VPS for normal pressure hydrocephalus using a Sophy programmable pressure valve (Model S3) with the valve pressure set a high. However, her symptoms did not improve, so an attempt was made to change the valve pressure from the high pressure position to the medium pressure position with a ring magnet. But the rotor could not be moved. The valve was exchanged and the valve pressure was set at medium, and the symptoms of the patient improved postoperatively. Examination of the removed valve revealed that the movement of the rotor with a ring magnet was not able to be carried out smoothly.(ABSTRACT TRUNCATED AT 250 WORDS)
Changes of plasma thromboxane level in subarachnoid haemorrhage (SAH) were studied clinically and experimentally using 11-dehydro-thromboxane B2 (11 DTX) as a measuring index. 11 DTX is a major long-lived metabolite formed from thromboxane (TX) B2, and is said to be a more reliable parameter for detecting TXA2 production in biological systems. In this clinical study, blood was sampled from the cubital vein of 10 SAH patients on the earliest possible day (day 0 or 1), during the vasospasm predilection period (day 7 approximately 11) and in the chronic stage (day 16 approximately 32). Plasma concentrations of 11 DTX and 6-keto-PGF 1 alpha were measured in clinical cases. A canine SAH model was produced by the two haemorrhage methods and blood was sampled from the superior sagittal sinus before and on day 4 of the first cisternal blood injection. 11 DTX, TXB2 and platelet function were examined in each sample. In the clinical studies, plasma 11 DTX levels tended to be higher in the early stage of SAH but decreased thereafter to the normal or lower level. Plasma concentrations of 6-keto-PGF1 alpha tended to decrease mildly during the vasospasm predilection period. In the experimental study, neither definite change of plasma 11 DTX level nor neurological deficit could be induced by the mimic SAH, while an increase in platelet aggregability and narrowing of the basilar artery were observed. 11 DTX was inferred to be a more reliable parameter of TX biosynthesis than TXB2.
A 15-year-old female was hospitalized for the treatment of systemic lupus erythematosus complicated with nephritis. She improved with administration of steroid hormones and an immunosuppressant, plasma exchange, and dialysis. However, a lung abscess developed 6 months after admission, and multiple brain abscesses appeared 2 months after the onset of the lung abscess. The lung abscess faded with oral administration of fluocytosine and intravenous administration of miconazole, but the brain abscesses enlarged. Intrathecal administration of miconazole was not effective. Therefore, the abscess in the right frontal lobe was surgically removed and an Ommaya's reservoir was placed in the anterior horn of the right lateral ventricle. Aspergillus was identified in the removed abscess. Subsequently, miconazole was administered intraventricularly through the Ommaya's reservoir 10 mg daily for 1 month. The abscesses in the left parietal lobe gradually diminished. One year later, she complained of right hypesthesia again. Computed tomography scan revealed enlargement of the abscess. Miconazole was administered intravenously and intraventricularly for 1 month. Second craniotomy was performed 16 months after the first surgery and the abscess was completely removed. She was discharged with mild hypesthesia of the right leg. It is concluded that intraventricular administration of miconazole through an Ommaya's reservoir is an effective therapy for central nervous system aspergillosis.
Tissue plasminogen activator (t-PA) is expected to be used for cisternal drainage in subarachnoidal hemorrhage, for dissolving of the residual hematoma after stereotactic evacuation of a cerebral hematoma, and for regional intraarterial injection therapy for occlusion of the primary cerebral artery. This is because the drug exerts a very potent and immediate dissolving-effect on a hematoma when it is locally administered. However, the solubility of t-PA is rapidly decreased at pH 5 or more. At pH 7 or more, precipitation of crystals is observed when the concentration of t-PA exceeds 20 x 10(4) IU/ml. The pH of the t-PA general-purpose solution (for intravenous injection) is adjusted at 4.6 to 4.8 because of its solubility and stability, and the osmotic pressure is also increased with an increase in concentration of t-PA. When the concentration of t-PA is 750 x 10(4) IU/ml, the osmotic ratio is 30 and the pH is 4.82. These features suggest that a locally administered t-PA solution at high concentration may induce meningeal irritation leading to headache and vomiting, and exacerbation of symptomatic cerebral vasospasm when it is used for cisternal drainage. Furthermore, the t-PA solution administered intraarterially at high concentration may induce adverse effects such as dessiocyte and echinocyte deformation of erythrocytes and the sludging phenomenon of leukocytes in the cerebral microcirculation, and a sensation of fever and pain upon injection. Therefore, the dose and method of administration of the t-PA for local intracranial use should be determined by taking into consideration its pH and osmotic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
Primary thrombocythemia is a chronic proliferative disorder of the bone marrow in which either thrombotic or paradoxically hemorrhagic symptoms or both may occur due to the pathological increase in the number of platelets. The mechanism of hemorrhagic diathesis in this disorder is not fully defined. We presented a rare case of primary thrombocythemia developing chronic subdural hematoma which was surgically managed with the use of plateletpheresis. It was believed that plateletpheresis was useful in controlling hemorrhagic complications during surgery associated with primary thrombocythemia. A 62-year-old man was admitted to the hospital for evaluation of motor weakness on the right side. The patient had no episode of head trauma. CT scan demonstrated the presence of subdural hematoma in the left frontotemporal region with significant ventricular shift and deformity. No definite abnormalities were disclosed on laboratory examination except for the hemogram in which platelet count was extremely elevated and read 109 x 10(4)/mm3. Examination of bone marrow smears disclosed an abnormal increase in megakaryocytes. Despite the increase in the number of the platelets, other coagulation studies gave normal results. Prior to surgery plateletpheresis was attempted in hopes of reducing the number of peripheral platelets and eventually avoiding the risk of hemorrhagic complications during surgery. As a result surgery for aspiration of the hematoma was successfully performed. The postoperative course remained uneventful as the patient continuously underwent two courses of plateletpheresis and chemotherapy. The patient was discharged with no neurological deficits and the peripheral platelets remained reduced in number at 50 x 10(4)/mm3 two months after discharge.
Influences of various factors on postoperative outcome of 122 well-documented cases, out of a total of 151 cases of middle cerebral artery aneurysm, are discussed in this paper. The shape of the aneurysm, major axis, major axis/neck and major/minor axis ratio were correlated with the presence or absence of a bleb (p less than 0.0000001), and indicated a correlation not only between aneurysmal shape and the outcome (p less than 0.05) but also between preoperative seriousness and the outcome (p less than 0.05). The preoperative seriousness and the grade of subarachnoid haemorrhage indicated a close correlation between each of these two parameters and the outcome (p less than 0.000001 for each). Both the quantity and the colour of CSF outflow from the chiasmal cistern showed close correlation with vasospasm (p less than 0.01), onset of hydrocephalus (p less than 0.01) and the outcome (p less than 0.001). Moreover, vasospasm and hydrocephalus grade itself also showed close correlation with the outcome (p less than 0.001 and p less than 0.00001). All parameters: blood pressure grade, BPmax, BPmin, BP fluctuation showed correlations not only with preoperative seriousness (p less than 0.001) and the outcome (p less than 0.0001) but also with subarachnoid haemorrhage frequency, number of aneurysms, and major axis/neck ratio.
Since computed tomography (CT)-guided stereotactic surgery is essentially blind surgery, it always involves the risk of injuring viable brain tissue and vessels, and it is difficult to obtain a sufficient amount of biopsy specimen from cystic or necrotic lesions. Moreover, the direct observation of the lesion would provide extremely valuable information. The authors have therefore developed a new subminiature rigid endoscope and an ultrasonic aspirator for use in stereotactic surgery, as well as a new micromanipulative system to attach the equipment to the stereotactic frame so that they can be accurately inserted into the optimum position from any direction. The new neuroendoscope includes a graded refractive index glass rod only 1.0 mm in diameter (Selfoc, Nippon Sheet Glass Co., Osaka), which provides a focal depth from 1 mm to infinity, as well as an extremely bright and wide visual field with an angle of 70 degrees. Furthermore, because the outer probe and endoscopic sheath share the outer rigid metal tube 4.5 mm in outer diameter, a large internal channel of 2.1 mm in diameter allows the introduction of various microinstruments such as an ultrasonic aspirator probe, laser probe, and biopsy forceps. When a miniaturized video camera is attached, the surgical procedures can be controlled using the video monitor and photographed. The new probe for the ultrasonic aspirator has been developed in various types suitable for fragmentation and aspiration of hematomas and brain tumors, so under endoscopic control even the harder coagulants and tumors can be removed.(ABSTRACT TRUNCATED AT 250 WORDS)