Biomedical subjects

T Kano

Publications and source records attributed to T Kano.

At least 19 recordsLinked to original sources

PubMed2006

Cerebral blood oxygenation changes induced by bypass blood flow in moyamoya disease and non-moyamoya cerebral ischaemic disease.

BACKGROUND: Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis has been used to prevent stroke in patients with moyamoya disease (MD) and non-moyamoya ischaemic disease (non-MD). However, little is yet known regarding the difference between these groups of patients in the extent to which the bypass contributes to maintaining adequate cerebral blood oxygenation (CBO), or the temporal changes after surgery. In the present study, we evaluated the CBO changes induced by bypass blood flow in patients with MD and non-MD during the peri-operative periods employing optical spectroscopy. METHODS: We investigated 13 patients who underwent STA-MCA anastomosis, including 5 MD and 8 non-MD patients. We evaluated the effects of STA blood flow on the CBO in the MCA territory on the anastomosis side, employing visual light spectroscopy during surgery and near infrared spectroscopy (NIRS) at one week after surgery. FINDINGS: In 4 MD patients and one non-MD patient, the STA blood flow increased the oxyhaemoglobin and cortical oxygen saturation (CoSO2), indicating that the bypass supplied blood flow to the ischaemic brain; the CBO changes were observed more frequently in MD than in non-MD patients (p<0.02). The pre-anastomosis CoSO2 (65.4+/-5.4%) in MD was significantly lower than that (72.8+/-7.6%) in non-MD (p<0.05). Postoperative NIRS demonstrated that the bypass began to supply blood flow to the brain in 5 non-MD patients whose bypass did not supply blood flow during surgery. CONCLUSIONS: Although MD has vessels of small diameter as compared to non-MD, the bypass begins to supply blood flow to the ischaemic brain earlier in MD than in non-MD after anastomosis. The fact that the CoSO2 in MD was lower than that in non-MD suggested that the perfusion pressure in MD was lower than that in non-MD, and this might account for the difference in the bypass blood supply after anastomosis between MD and non-MD. Our data suggest that, even if the bypass does not supply blood to the brain during surgery in non-MD, the bypass blood flow gradually increases after surgery.

Adolescent↗

PubMed2005

Relationship between intraoperative transoesophageal echocardiography findings and perfusion lung scintigraphy results on first postoperative day.

BACKGROUND: Although intraoperative transoesophageal echocardiography (TOE) has been used to detect the occurrence of echogenic macro- and/or microembolic phenomena during total hip arthroplasty (THA), no direct correlation between macroembolism and the formation of pulmonary embolism (PE) has been conclusively determined in early postoperative periods after THA. METHODS: Sixty-two patients scheduled for primary THA were enrolled in this study. Intraoperative TOE images were continuously recorded on videotape and the echogenic events were evaluated throughout surgery. Perfusion lung scintigraphy was performed on the first postoperative day (POD1). RESULTS: Perfusion lung scintigraphy revealed the existence of PE in nine (15%) of the 62 patients who underwent THA: five (25%) of 20 patients with cemented THA and four (10%) of 42 patients with non-cemented THA. The grading score of intraoperative TOE findings, including the amount of echogenic particles in right atrium, the longest time of echogenesis and the diameter of the largest echogenic particles, did not differ between the groups with and without PE. The sensitivity, specificity, and positive and negative predictive values for the detection of echogenic macroemboli for the prediction of the development of PE on POD1 were 0.78, 0.60, 0.25 and 0.94, respectively. CONCLUSION: Intraoperative TOE monitoring did not predict the occurrence of PE on POD1.

Adult↗

PubMed2005

Periodic oscillatory activity in parahippocampal slices maintained in vitro.

Brain slices maintained in vitro have been extensively used for studying neuronal synchronization. However, the validity of this approach may be questioned since pharmacological procedures are usually required to elicit spontaneous events similar to the EEG activity recorded in vivo. Here, we report that when superfused with control medium, rat brain slices comprising the entorhinal and perirhinal cortices along with a portion of the basolateral/lateral nuclei of the amygdala can synchronously generate periodic oscillatory activity at 5-11 Hz every 5-30 s. The periodic events: (i) correspond intracellularly to synaptic depolarizations in regularly firing neurons analyzed in the three areas; (ii) have no fixed site of onset; (iii) spread with time lags of 8-20 ms; and (iv) continue to occur asynchronously after their surgical isolation. NMDA receptor antagonism reduced the duration of the oscillatory events, while glutamatergic non-NMDA receptor antagonism abolished them. Activation of mu-opioid receptors, a procedure that hyperpolarizes interneurons thus decreasing GABA release, reversibly decreased the rate of occurrence of periodic oscillatory activity (POA). However, periodic events continued to occur during application of GABA(A) or GABA(B) receptor antagonists as well as in the presence of the cholinergic agent carbachol. We also found that POA was abolished by baclofen and irreversibly reduced by the gap junction decoupler carbenoxolone. These findings demonstrate that parahippocampal networks in a brain slice preparation can generate periodic, synchronous activity under quasi-physiological conditions. These network oscillations (i) reflect the activation of ionotropic glutamatergic and GABAergic receptors, (ii) are contributed by gap-junction interactions, and (iii) are controlled by GABA(B) receptors that are presumably located presynaptically.

Action Potentials↗

PubMed2003

Infiltration of tissue plasminogen activator through cerebral vessels: evaluation using a rat thromboembolic stroke model.

In recent years, evidence has been accumulating that tissue plasminogen activator (tPA) possesses neurotoxic effects. However, such deleterious effects have been attributed to endogenously generated tPA. In the present study, focusing on exogenously administered tPA for the purpose of fibrinolysis, we evaluated the extent and the degree of extravasated tPA in a rat model of thromboembolic stroke. Even after early recanalization of occluded cerebral vessels, significant infiltration of tPA occurred through the cerebral vessels. It is assumed that exogenous tPA also exerts neurotoxic effects in the ischemic brain tissue.

Animals↗

PubMed2002

Two types of optical coherence tomographic images of retinal pigment epithelial detachments with different prognosis.

AIMS: To report the optical coherence tomographic (OCT) findings in retinal pigment epithelium (RPE) detachments. METHODS: 24 eyes were analysed by OCT and by fluorescein (FAG) and/or indocyanine green angiography. RESULTS: RPE detachments were classified by the OCT images into those with a partial or total highly reflective line in the area of the detachment (nine eyes), and those that showed the same reflex in the detached area as in other parts (15 eyes). The nine eyes had irregular hyperfluorescence by FAG, significantly larger detachments, and lower visual acuity than the 15 eyes. CONCLUSION: The OCT showed that two types of RPE detachments are associated with eyes with different characteristics.

Adult↗

PubMed2001

Visual function after removal of subretinal neovascular membranes in patients with age-related macular degeneration.

BACKGROUND: Retinal pigment epithelial (RPE) cells have been transplanted to replace the RPE cells lost after surgical excision of choroidal neovascular membranes (CNV) associated with age-related macular degeneration. The purpose of this study was to analyze the visual function of eyes with altered RPE after surgical excision of choroidal neovascular membranes (CNV) associated with age-related macular degeneration, and to determine the effect of proliferated or migrated RPE cells on visual function. METHODS: Forty-seven patients with age-related macular degeneration underwent excision of CNVs following vitrectomy and tamponade with sulfur hexafluoride (SF6) or silicone oil. The appearance of pre- or subretinal fibrosis and pigmentation of the lesion was considered to indicate proliferation and migration of RPE cells. Microperimetry was also performed. RESULTS: A significant correlation was found between the size of CNVs removed by surgery and the size estimated by indocyanine green angiography (P=0.0126). The mean number of RPE cells lost was estimated at 1.52 x 10(4). Pre- or subretinal fibrosis or pigmentation was observed in 37 patients (75.5%). The number of eyes with fibrosis was significantly higher in eyes with silicone oil tamponade than with SF6 tamponade (P=0.0016). A statistically significant correlation was not found between the presence of fibrosis or pigmentation and the postoperative visual acuity. Not all patients used the area of pigmentation for fixation, and microperimetry showed that some of the patients had scotomas in well-pigmented areas. CONCLUSIONS: Fibrosis and pigmentation after excision of CNVs may not always indicate normal function in these areas. These observations are especially relevant for transplantation of pigment epithelial cells in the future.

Aged↗

PubMed2001

Effects of gastrointestinal stimulant and suppressant pretreatment on the pharmacokinetics of AS-924, a novel ester-type cephem antibiotic.

The effects of pretreatment with the gastrointestinal stimulant domperidone and the suppressant scopolamine butylbromide on the absorption of AS-924, a novel prodrug-type cephem antibiotic, were investigated in six healthy adult male volunteers by a cross-over method. The T(max) of ceftizoxime (CTIZ), the active moiety of AS-924, was slightly prolonged by scopolamine butylbromide (T(max)=1.8 vs. 1.5 h for the group without pretreatment). However, there were no significant differences in pharmacokinetic parameters including T(max), cumulative urinary excretion rates of CTIZ and cumulative urinary excretion rates of pivaloylcarnitine for 12 h after the dosing between the pretreated and control groups. Domperidone did not affect the absorption of AS-924.

Adult↗

PubMed2001

Hemorrhagic transformation after fibrinolysis with tissue plasminogen activator: evaluation of role of hypertension with rat thromboembolic stroke model.

BACKGROUND AND PURPOSE: We used a rat model of thromboembolic stroke to evaluate whether hypertension increases the incidence of hemorrhage after fibrinolysis with tissue plasminogen activator (tPA). METHODS: In this model, a microclot suspension was injected into the middle cerebral artery territory to induce focal ischemia. Reperfusion was induced in spontaneously hypertensive rats (SHR) by administering tPA (10 mg/kg) intravenously at 2 hours or 6 hours after the onset of thromboembolic focal ischemia. In untreated control rats, saline was administered at 2 hours after ischemia. RESULTS: Hemorrhagic transformation was observed only in rats that received tPA at 6 hours (6 of 8 rats [75%]). Reduction of mean arterial blood pressure from 122+/-3 to 99+/-2 mm Hg with hydralazine, given to SHR for 1 week before ischemia, significantly decreased the incidence of hemorrhage in 2 of 11 rats (18%). tPA reduced infarct volumes, but cotreatment with hydralazine did not result in further protection. CONCLUSIONS: This study demonstrates that in this rat thromboembolic model of stroke, tPA-induced hemorrhage is dependent on blood pressure and that pharmacological reduction of hypertension during fibrinolysis can reduce the risk of hemorrhagic transformation.

Animals↗

PubMed2001

Long-term outcome of patients with ergonovine induced coronary constriction not associated with ischemic electrocardiographic changes.

OBJECTIVES: This study investigated the long-term outcome of patients with coronary artery constriction induced with ergonovine but not associated with ischemic electrocardiographic changes. METHODS: The ergonovine provocation test was performed in 419 patients with suspected but unproven variant angina. Ergonovine maleate was administered into the coronary arteries at 8 micrograms/min for 5 min during cardiac catheterization. Patients were categorized into three groups according to their response to ergonovine. The positive group contained patients who developed coronary constriction of more than 90% in diameter associated with ischemic electrocardiographic changes and chest pain. The intermediate group contained patients who had coronary constriction of more than 90% but no electrocardiographic changes. The negative group contained patients who had neither significant coronary constriction nor ST segment changes. RESULTS: There were 305 patients, 49, and 65 in the negative, intermediate, and positive groups, respectively. Death occurred in six patients (2%), one (2%), and one (2%) in the negative, intermediate, and positive groups, respectively. Sudden cardiac death occurred in one patient in the negative group. Recurrence of chest pain with effectiveness of sublingual administration of nitroglycerine was observed in 26 patients (9%), 10 (20%), and 11 (17%) in the negative, intermediate, and positive groups, respectively. CONCLUSIONS: Some patients in the intermediate group might show "false negative" response to ergonovine so careful treatment with calcium antagonists should be continued in patients in the intermediate group as well as patients with vasospastic angina.

Coronary Angiography↗

PubMed2001

[Anesthetic management of a patient with a history of acute intermittent porphyria and an elevation of urinary porphobilinogen].

A 55 year-old female with a history of acute intermittent porphyria (AIP) in her twenties was scheduled for left total hip replacement. The clinical symptoms had been mild for the past 30 years, with occasional appearance of muscular weakness in the extremities. Porphyric symptoms were not apparent on the pre-operative round, but urinary porphobilinogen (PBG) was elevated on the pre-operative examination. Anesthesia was induced with propofol and the trachea was intubated by use of suxamethonium. Anesthesia was maintained with inhalation of 1.5-2.0% isoflurane and 50% N2O in O2. Twenty ml of 1% mepivacaine was injected around the wound at the completion of surgery. It was effective for postoperative pain control. We could successfully manage the patient during the intra- and post-operative periods without appearance of porphyric symptoms and increases of PBG and delta-aminolevulinic acid.

Anesthesia, General↗

PubMed2001

[Usefulness of hepatic arterial infusion chemotherapy for liver metastasis in gastric cancer].

UNLABELLED: We have performed intra-hepatic arterial chemotherapy for 9 patients with liver metastasis arising from gastric cancer. We mainly used 5-FU and CDDP as antineoplastic drugs. RESULTS: The median survival after gastrectomy was 600 days. Of 9 cases, 2 showed CR, 4 PR, 2 NC, 1 PD. The response rate was 67%. The 9 cases were classified into 2 groups. One group, the short-term survival group, concised of 5 patients that had no more than 2 years survival and the other, the long-term survival group, consisted 4 patients that had more than 2 years survival. We compared these 2 groups and found no difference in the primary lesions between the 2 groups. The patients in the long-term survival group had fewer and smaller metastatic lesions in the liver than the patients of the short-term survival group. The patients in the long-term survival group had no unresectable lesions except liver metastasis when gastrectomy was performed. However, 2 patients in the short term survival group had unresectable lymphatic involvement at the time gastrectomy was performed. Of 9 patients, 6 died from the extrahepatic lesion. CONCLUSION: The intra-arterial chemotherapy was effective and useful for liver metastasis arising from gastric cancer. However, the majority of patients died from extrahepatic lesions. We should therefore consider the use of systemic chemotherapy with intra-arterial chemotherapy.

Aged↗

PubMed2001

[Radiographic examination of skeletalized remains of an abandoned infant: a case report with special reference to odontological findings].

A homeless couple confessed that they had buried their baby, who died at the age of three months, in the graveyard two years earlier. The recovered infantile remains had been already completely skeletonized and dismembered. However, the maxilla and mandibula of the average matured infants, the age of the body was estimated to be 1 to 2.5 months old on the basis of the degree of calcification of deciduous teeth.

Age Determination by Teeth↗

PubMed2000

Hemorrhagic transformation after fibrinolytic therapy with tissue plasminogen activator in a rat thromboembolic model of stroke.

In this study, the effects of early vs. delayed tPA treatment on the development of hemorrhagic transformation was compared in a rat thromboembolic model of stroke. Fibrinolysis was performed by administering tPA intravenously at 2 or 6 h after ischemic onset. Twenty-four hours later, confluent hemorrhagic infarction was observed only in rats treated with tPA at 6 h at the rate of 50%. In this delayed treatment group, significantly increased numbers of polymorphonuclear leukocytes (PMNL) were observed to accumulate inside microvessels within the ischemic core. PMNL accumulation may be related to the induction of hemorrhagic infarction after delayed tPA treatment.

Animals↗

PubMed2000

Macular degeneration associated with aberrant expansion of trinucleotide repeat of the SCA7 gene in 2 Japanese families.

OBJECTIVE: To evaluate the macular function of Japanese patients with a trinucleotide repeat expansion in the spinocerebellar ataxia type 7 (SCA7) gene. METHODS: Ophthalmic findings in patients whose DNA analysis revealed expanded alleles of the trinucleotide repeat in the SCA7 gene were evaluated. RESULTS: Trinucleotide repeat was expanded from 40 to 48 in affected patients (control subjects, 12 repeats). Affected patients were characterized by different degrees of visual acuity decrease (0.09-0.9), a tritan axis color vision, a coarse granular appearance of the macular region on scanning laser ophthalmoscopy, depression of multifocal electroretinograms, and macular degeneration. However, pigmentary changes were not observed in the retina. The trinucleotide repeat was longer and the onset of macular dysfunction was earlier in the younger generation. One patient in a family manifested decreased visual acuity 10 years preceding other neurologic signs. CONCLUSIONS AND CLINICAL RELEVANCE: Patients with SCA7 mutations showed macular dysfunction or degeneration with expansion of CAG repeat in the SCA7 gene. However, the lesions were less pigmented than those previously reported. Patients also showed ophthalmologic anticipation, which has not been reported for the ocular changes in other patients who have trinucleotide repeat expansion of the responsible genes.

Adult↗

PubMed2000

Choledochoduodenostomy: simple side-to-side anastomosis.

Choledochoduodenostomy, using a simple side-to-side anastomosis technique, was performed in a 74-year-old woman with common bile duct stones. She had chronic heart failure and chronic obstructive lung disease. The choledochoduodenostomy was performed with a cholecystectomy. A 2-cm-longitudinal incision was made in the common bile duct, and an adjacent longitudinal incision was made in the first portion of the duodenum. The first sutures to be placed were the two corner sutures of the posterior anastomotic wall. Then the two sides were sutured, one from the hepatic side corner of the common duct to the anal side corner of the duodenum, and the other from the duodenal side corner of the common duct to the oral side corner of the duodenum. This anastomosis was performed with one layer of interrupted 4-0 adsorbable sutures. The anterior wall of the anastomosis was constructed in a similar manner. The patient recovered uneventfully, and had no complaints of abdominal pain or fever. This procedure, our original method, is technically simple and safe, and results in minimal tension of the anastomosis.

Aged↗

PubMed2000

Trans-mesosigmoid cutaneous ureterostomy.

BACKGROUND: A new method was developed in order to create a single stoma cutaneous ureterostomy in which both ureters traverse the abdominal cavity and yet are buttressed by the mesosigmoid and covered by its visceral peritoneum. METHODS: The long mesenterium which is attached to the most mobile part of the sigmoid colon was used for the bilateral ureteral pathway. Tunnels for the ureteral path were made just underneath the visceral peritoneum on the bilateral side of the mesosigmoid. Through the tunnels both ureteral ends were brought from the retroperitoneal space to the mesenterocolonic junction (MCJ) and the MCJ is then approximated and sutured to the inside of the ureteral tract through the abdominal wall. The ureters brought outside the skin, are conjoined and sutured to the V skin flap. Eight patients who carried a high risk for operation and/or had a bladder tumor judged to be incurable underwent this cutaneous ureterostomy. RESULTS: All cases except one with low urinary output could be managed without catheter indwelling during the follow-up period. Three patients suffered from paralytic ileus and one required laparotomy for mechanical ileus during the short postoperative period. Postoperative excretory urography evaluated 14 kidneys during the follow-up period from 2 to 61 months and showed normal upper urinary tract in 11 and a mildly hydronephrotic tract in three. CONCLUSIONS: Transmesosigmoid cutaneous ureterostomy provides a single catheterless stoma even when the available ureters are relatively short. It appears to be a good method for supravesical urinary diversion when indicated.

Aged↗

PubMed2000

Sequential changes of arterial oxygen tension in the supine position during one-lung ventilation.

UNLABELLED: To investigate how surgical positions affect the severity and progress of hypoxemia during one-lung ventilation (OLV), we studied 33 adult patients undergoing right thoracotomy with left OLV. The patients were divided into three groups according to the positions during surgery as follows: the supine position (SP) group (n = 11), the left semilateral decubitus position (LSD) group (n = 9), and the left lateral decubitus position (LLD) group (n = 13). Analysis of arterial blood gases was sequentially determined every 5 min for 30 min during OLV (fractional ratio of inspiratory oxygen = 1.0) in each position. OLV was promptly terminated and switched to bi-lung ventilation if Spo2 declined to 90%. Pao2 progressively decreased with time in all three groups (P < 0.01). The incidence of termination of OLV within 30 min was higher in the SP group (82%), compared with that in the LSD (11%) and LLD (8%) groups (P < 0.01). Final Pao2 (65+/-12 mm Hg, mean +/- SD, P < 0.01 versus LLD, P < 0.05 versus LSD) and SaO2 (91%+/-4%, P < 0.01 versus LLD and LSD) at the termination of OLV in the SP group were the lowest. There was no difference between these values in the LSD and LLD groups (128+/-54 mm Hg, 96%+/-2%, and 167+/-69 mm Hg, 97%+/-4%, respectively) 30 min after the start of OLV. The time for Pao2 to decrease to 200 mm Hg calculated from each regression curve was 354 s in the SP group, 583 s in the LSD group, and 798 s in the LLD group. The time for Pao2 to decline to 100 mm Hg was 794 s in the SP group. In the regression curves of the LSD and LLD groups, the Pao2 did not decrease to 100 mm Hg. Heart rate was slow at baseline in the SP group (P < 0.05 versus LSD), but other hemodynamic variables did not differ among the three groups throughout this study. The LSD was as effective as the LLD in avoiding life-threatening hypoxemia during OLV. IMPLICATIONS: Close observation and prompt counteractions including termination of one-lung ventilation (OLV) are crucial for patients under OLV in the supine position, because life-threatening hypoxemia frequently occurs approximately 10 min after starting OLV, even under 100% oxygen inhalation. The left semilateral decubitus position was as effective as the left lateral decubitus position in avoiding life-threatening hypoxemia during OLV.

Blood Gas Analysis↗

PubMed2000

Auto iris pigment epithelial cell transplantation in patients with age-related macular degeneration: short-term results.

Autologous iris pigment epithelial cell transplantation was performed on patients with exudative age-related macular degeneration (AMD). Autologous IPE cell culture was performed using autologous serum after iridectomy in 7 patients with AMD. The cell suspensions (2 approximately 20 x 10(4) cells) were transplanted into the submacular lesion of individuals after removal of neovascular membranes. Subsequent ophthalmological examinations, including best corrected visual acuity and fluorescein or indocyanine green angiography, were performed. In addition, 15 patients with AMD, who underwent removal of neovascular membrane without transplantation, were evaluated as non randomized controls. Varying degrees of atrophy or defects of choriocapillaris and retinal pigment epithelium were observed in all of the patients. No cystoid macular edema or fluorescein leakage was observed after treatment, but window defects were present. No patient had decreased visual acuity. One treated patient developed mild subretinal fibrosis and an other patient developed mild preretinal fibrosis, however no difference was significant when compared with the control. In conclusion, the treatment resulted in no significant improvement in macular function, as compared with the control; however, no rejection or deterioration in visual acuity occurred up to the 13 month follow up.

Aged↗