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Biomedical subjects

K Sasai

Publications and source records attributed to K Sasai.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Magnetic resonance T1 gradient-echo imaging in hepatolithiasis.

BACKGROUND: We examined the role of magnetic resonance T1-weighted gradient-echo (MRT1-GE) imaging in hepatolithiasis. METHODS: MRT1-GE, precontrast computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP) of 10 patients with hepatolithiasis were compared for their diagnostic accuracies in the detection and localization of intrahepatic calculi. The diagnosis of hepatolithiasis was confirmed by surgery. For localization of the stone, we divided the bile ducts into six areas: right and left hepatic ducts and bile ducts of the lateral, medial, right anterior, and right posterior segments of the liver. Chemical analysis of the stones was performed in eight patients. RESULTS: The total number of segments proved by surgery to contain stones was 18. Although not significantly different, the sensitivity of MRT1-GE was 77.8% (14 of 18 segments), higher than that of MRCP (66.7%, 12 of 18 segments) and that of CT (50%, nine of 18 segments). The sensitivity of magnetic resonance imaging (MRCP + MRT1) was significantly higher than that of CT (p < 0.01). Multiple logistic regression analysis showed that the result of surgery was significantly affected only by the result of magnetic resonance imaging. On MRT1-GE, all the depicted stones appeared as high-intensity signal areas within the low-intensity bile duct irrespective of their chemical composition. CONCLUSION: MRT1-GE imaging provides complementary information concerning hepatolithiasis.

Adult↗
PubMedDate not supplied

Transcatheter arterial embolization for malignant osseous and soft tissue sarcomas. II. Clinical results.

PURPOSE: To evaluate the clinical effects of transcatheter arterial embolization (TAE) on malignant bone and soft tissue tumors. METHODS: TAE was performed in 10 patients with primary bone and soft tissue sarcomas and in 31 patients with metastatic bone tumors. The embolized arteries were the internal iliac artery in 30 cases, the intercostal artery in six cases, the lumbar artery in five cases, the suprascapular artery in three cases, and the iliolumbar artery, the internal pudendal artery, and the lateral sacral artery in one case each. The embolized material was gelatin sponge particles. The chemotherapeutic drugs were usually 20-40 mg of doxorubicin for primary and metastatic tumors and 50-100 mg of cisplatin only for primary tumors. In addition, 50-60 Gy of 10-MV radiotherapy with or without radiofrequency (RF)-capacitive hyperthermia in four sessions was administered before TAE for primary tumors only. RESULTS: Even though the pain score increased immediately after TAE, 30 of 38 (79%) patients with pain (8 of 9 with primary tumors, and 22 of 29 with metastases) achieved pain control after TAE. A necrotic low-density area shown by computed tomography (CT) after TAE was found in 31 of 41 (76%) tumors [8 of 10 (80%) with primary tumors, and 23 of 31 (74%) with metastatic tumors]. The tumor size decreased in 14 of 25 (56%) primary and metastatic tumors after 3 months. Osteosclerotic changes appeared in two cases of metastatic tumors after 6 months. In five tumors resected after TAE, large areas of necrosis within the tumor were confirmed histologically. Transient local pain and numbness appeared after TAE, but were relieved by drug treatment within 1 week. No severe complications except a case of gluteal muscle necrosis were encountered after TAE. The 1-year survival rate of the patients with primary tumors was 38.1%, and the median survival was 18 months. The longest survival was 84 months. The 1-year survival rate of the patients with metastatic bone tumors was 38.9%; the median survival was 12 months. The longest survival was 24 months. CONCLUSION: TAE could be an effective treatment for pain control and local control of malignant bone and soft-tissue tumors.

Adolescent↗
PubMedDate not supplied

Long-term outcome after radiation therapy for subfoveal choroidal neovascularization associated with age-related macular degeneration.

PURPOSE: The purpose of this study was to investigate the long-term effect of low-dose radiation therapy on subfoveal choroidal neovascularization associated with age-related macular degeneration. METHODS: The clinical course and visual outcome were compared retrospectively among two treated groups and a control group; 15 patients (15 eyes) received 10 Gy, another 15 patients (15 eyes) received 20 Gy. The control group consisted of 15 patients (15 eyes) without treatment. All patients were followed up for at least 18 months, and most were followed up for 3 years. The macula was irradiated with either 10 Gy in 5 fractions or with 20 Gy in 10 fractions after computed tomography (CT) simulation enabled real-time treatment planning from multiple CT slices. RESULTS: During the 3 years of follow-up, the lesions became better in 5 eyes, unchanged in 1, and worse in 9 with 10 Gy radiation; better in 7 eyes, unchanged in 1, and worse in 7 eyes with 20 Gy; and better in 1 eye and worse in 14 with no treatment. The difference between the groups treated with radiation and the control was statistically significant (P <.05). Visual acuity was also significantly better in the group receiving 20 Gy than in the control group up to 2 years after radiation (P <.01). CONCLUSION: Radiation may extend the period of good visual function substantially by reducing subfoveal choroidal neovascularization activity.

Aged↗
PubMedDate not supplied

Spared flow tract within the mural thrombus of an aortic aneurysm: its pathogenesis and clinical importance.

The purpose of this case report is to determine the unique pathogenesis of a "spared flow tract" through a thick mural thrombus of an aortic aneurysm mimicking the penetrating or dissecting tract of an impending or acute rupture of an abdominal aortic aneurysm (AAA) and to discuss its clinical importance. Three blood flow tracts (i.e., spared flow tracts) penetrating to aortic major branches (inferior mesenteric arteries in two and left renal artery in one) through thick mural thrombi of three aortic aneurysms were found on thin section spiral CT scans. Histopathological examination revealed that the tracts were formed by thrombi and partially covered with endothelial cells. In conclusion, spared flow tracts may be pathways continuing to the aortic major branches through thick mural thrombi of aortic aneurysms and are spared from thrombogenesis because of relatively high blood flows. Their pathogenesis is definitely different from penetrating or dissecting tracts within mural thrombi of ruptured AAAs. Spared flow tracts should not be misinterpreted as penetrating or dissecting tracts of impending or acute rupture.

Acute Disease↗
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Concurrent chemoradiotherapy combined with intraoperative radiotherapy for locally advanced pancreatic cancer: a feasibility study.

Initial clinical results of concurrent chemoradiotherapy combined with high-dose intraoperative radiotherapy (IOR) for locally advanced pancreatic cancer were analyzed. Between June 1996 and May 1999, 6 patients with locally advanced pancreatic cancer without distant metastasis were treated with preoperative concurrent chemoradiotherapy followed by IOR. Preoperative radiation therapy was given by the dynamic arc conformal technique with a daily fraction of 1.8 Gy to a total dose of 45 Gy in 5 weeks. Cisplatin (5 mg/day for 4 weeks) and 5-fluorouracil (250 mg/day for 5 weeks) were administered continuously during preoperative radiation therapy. IOR as a single dose of 28 or 30 Gy was given to the gross tumor volume using electron beams of 15- to 22-MeV. Concurrent chemoradiotherapy was well tolerated, although all of the patients complained of nausea and fatigue. Two patients developed grade III leukopenia. No other serious acute toxicity was noted. The median survival time of the 6 patients was 17.5 months, which was significantly longer than that of our historical control treated with external radiation therapy with IOR (8 months), although the difference in survival was borderline significant (p=0.068). Concurrent chemoradiotherapy followed by high-dose IOR was well tolerated in patients with locally advanced pancreatic cancer, and the initial clinical results appeared promising.

Adult↗
PubMedDate not supplied

Evaluation of the efficacy of Salmonella enteritidis oil-emulsion bacterin in an intravaginal challenge model in hens.

The efficacy of Salmonella enteritidis (SE) oil-emulsion bacterin (a commercially available vaccine) was evaluated in an intravaginal challenge model in hens producing a high rate of SE-contaminated eggs. Hens were vaccinated at 38 wk of age. A second (booster) bacterin injection was administered 4 wk later. Two weeks after the second vaccination, all hens were challenged intravaginally with 10(7) colony-forming units of SE. After challenge, 36 of 189 eggs (19.0%) in the vaccinated hens were positive for SE, and this contamination rate was significantly (P < 0.01) lower than that in the unvaccinated hens (61 of 165 eggs, 37.0%). SE was highly recovered from the cloacal and vaginal swabs of the unvaccinated and vaccinated hens, but the number of SE from the cloaca of the vaccinated hens was significantly (P < 0.05) lower than that in the unvaccinated hens at 7 days post-challenge (PC). The recoveries of SE from the spleen and ovary in the vaccinated hens were significantly (P < 0.05) lower than those in the unvaccinated hens at 7 days PC. At necropsy, SE was recovered from 2 of 15 forming eggs (13.3%) taken from the oviducts of the unvaccinated hens, whereas no SE was recovered from 17 forming eggs in the vaccinated hens. After vaccination, serum antibodies for SE in the vaccinated hens were significantly higher than those in the unvaccinated hens. Antibodies from the oviductal washing, especially immunoglobulin G isotype, in the vaccinated hens were higher than those in the unvaccinated hens after challenge. This intravaginal challenge model produced frequent contaminated eggs and clearly demonstrated the ability of the bacterin to protect against egg contamination. The present model may be a useful tool for further studies to evaluate the protective effect against SE contamination of eggs by potential vaccine candidates.

Administration, Intravaginal↗
PubMedDate not supplied

Differences among six Salmonella serovars in abilities to colonize reproductive organs and to contaminate eggs in laying hens.

The abilities of Salmonella serovars to colonize the reproductive organs of chickens and to contaminate eggs were compared. Mature laying hens were inoculated intravenously with 10(5) colony-forming units of Salmonella enteritidis, Salmonella typhimurium, Salmonella infantis, Salmonella hadar, Salmonella heidelberg, or Salmonella montevideo to cause the systemic infection. Salmonella enteritidis was recovered from three yolks of the laid eggs (7.0%), suggesting egg contamination from the transovarian transmission of S. enteritidis. The liver, spleen, and cecum were colonized by each serovar similarly at 4 or 7 days postinoculation (PI), whereas the ovary and preovulatory follicles were colonized by S. enteritidis with significantly (P < 0.05) higher levels than by the other serovars at 4 and 7 days PI. Salmonella enteritidis was recovered from the cloaca and vagina at 2, 4, and 7 days PI and from the other portions of the oviduct at 4 and 7 days PI. In addition, S. enteritidis had been persistent in the peripheral blood for 7 days PI. These results suggest that S. enteritidis is the predominant serovar to colonize the reproductive organs of mature laying hens among six serovars used in this study, reflecting the field situatibn in which the predominant outbreaks of human salmonellosis were caused by S. enteritidis-contaminated eggs recently. The ability of S. enteritidis to colonize the reproductive organs may be one of the reasons that egg contamination with S. enteritidis has increased.

Animals↗
PubMedDate not supplied

Central neurogenic hyperventilation with primary cerebral lymphoma: a case report.

We report a case of a bright, alert patient with central neurogenic hyperventilation (CNH) associated with cerebral malignant lymphoma. CNH is a syndrome comprising normal or elevated arterial oxygen tension, decreased arterial carbon dioxide tension, and respiratory alkalosis in the absence of cardiac or pulmonary disease that stimulates a compensatory hyperpnea. A-72-year-old man with recurrent central nervous system lymphoma presented with hyperpnea. showing a respiratory rate over 30 per minute. He was fully awake and conscious. Routine laboratory studies and chest X-ray were normal, but arterial blood gas examination on room air showed respiratory alkalosis, regardless of wakefulness or sleep. Pulmonary infarction was denied by pulmonary flow scintigram. Rebreathing from a paper bag, intravenous administration of diazepam, and oxygen inhalation failed to alter the respiratory pattern. Brain MRI demonstrated two mildly enhanced lesions within the left side of the medulla oblongata and right side of the pons. CNH is rare in patients with normal consciousness. It seems to be caused by brainstem injury that includes the respiratory center.

Aged↗
PubMedDate not supplied

Differences in abilities to colonize reproductive organs and to contaminate eggs in intravaginally inoculated hens and in vitro adherences to vaginal explants between Salmonella enteritidis and other Salmonella serovars.

In Experiment 1, mature laying hens were inoculated intravaginally with 10(6) colony-forming units of Salmonella enterica serovar enteritidis (S. enteritidis), Salmonella typhimurium, Salmonella infantis, Salmonella hadar, Salmonella heidelberg, or Salmonella montevideo to compare their abilities to colonize the reproductive organs of chickens and to contaminate eggs. Salmonella enteritidis was more frequently recovered (from 11 of 40 eggs, 27.5%) than the other serovars, and especially the inner shell was contaminated with these organisms in 10 of 40 eggs (25.0%). The contamination rates and the viable counts in cloaca were significantly (P < 0.05) higher in hens inoculated with S. enteritidis than in those inoculated with the other serovars at 4 days postinoculation (PI). In the vagina, the positive rates were 90%-100% in hens inoculated with S. enteritidis, and the viable counts of the organisms in this portion were significantly (P < 0.05) higher than those of the other serovars at 2, 4, and 7 days PI. The ceca were colonized similarly by each serovar at 7 days PI. The spleen and ovary were infected with S. enteritidis in three and one hen, respectively. No Salmonella was recovered from liver and peripheral blood in any hen. Salmonella enteritidis was recovered from other oviductal portions than the vagina (10%-20%), whereas no forming egg was contaminated in the oviduct. In Experiment 2, the in vitro adherence of these six serovars to the vaginal epithelium was compared with vaginal explants. The mean number of S. enteritidis attaching to the secondary villi in the vaginal lumen was significantly (P < 0.05) higher than those of the other serovars. These results suggest that S. enteritidis has a specific advantage over the other Salmonella serovars by its capacity to colonize the vaginal tissues of hens, and this higher affinity of S. enteritidis to the vagina may play a significant role in the production of many S. enteritidis-contaminated eggs.

Animals↗
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Focal T2 hyperintensity in the dorsal brain stem in patients with vestibular schwannoma.

BACKGROUND AND PURPOSE: The vestibular nucleus cannot be visualized on MR imaging, but some patients with vestibular schwannoma show a tiny area of hyperintensity in the dorsal brain stem on T2-weighted images. The aim of this study was to determine whether this tiny area is characteristic of vestibular schwannoma. METHODS: We retrospectively reviewed the postoperative MR images of 53 patients with cerebellopontine angle tumor. MR images were obtained with a 1.5T scanner. Spin-echo pre- and postcontrast 3-mm-thick T1-weighted axial images, 3-mm-thick fast spin-echo (FSE) T2-weighted axial images, and 0.8-mm-thick constructive interference in steady state (CISS) axial images were acquired. Surgical and histopathologic diagnosis was vestibular schwannoma (41/53 = 77%), meningioma (7/53 = 13%), epidermoid cyst (3/53 = 6%), glioma with exophytic growth (1/53 = 2%), and chordoma (1/53 = 2%). RESULTS: A tiny area of hyperintensity was observed at the lateral angle of the fourth ventricle floor in 6 patients (3 men, 3 women; age range, 24-54 years; mean age, 43 years) with vestibular schwannoma larger than 2 cm in maximal diameter on both FSE T2-weighted and CISS images. Preoperative MR images with the same pulse sequences showed the same area of hyperintensity in all these patients. CONCLUSION: Because the location of the area of hyperintensity is coincident with the vestibular nucleus, the hyperintensity may represent degeneration of the nucleus. This hyperintensity should not be confused with a postoperative lesion or a small infarction. If such hyperintensity is seen in a patient with a large cerebellopontine angle tumor, a diagnosis of vestibular schwannoma is suggested.

Adolescent↗
PubMedDate not supplied

Preduodenal portal vein in an adult--angiography and CT.

We report on an adult case of preduodenal portal vein illustrated by computed tomography (CT) and angiography. These diagnostic modalities were initially performed to evaluate a coexisting pancreatic cancer. Contrast-enhanced CT demonstrated unusual positioning of the portal vein ventral to the duodenum. The superior mesenteric-portal vein, which was L-shaped and convexly caudad, strongly suggested this anomalous condition.

Angiography↗
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The effects of dietary lactose and rye on cecal colonization of Clostridium perfringens in chicks.

Five experiments were conducted to determine the effects of dietary lactose and rye on cecal colonization of Clostridium perfringens in white leghorn chickens. Six days after oral inoculation of the organism, the numbers of C. perfringens organisms in the cecal contents were significantly lower in chickens on 2% and 10% lactose-supplemented feed than in chickens on unsupplemented feed. When C. perfringens was given in drinking water, 10% lactose supplementation was needed to significantly reduce the counts of C. perfringens 4, 6, and 8 days after feeding began. Effect of rye-ration on cecal colonization of C. perfringens was also examined. Counts of C. perfringens in cecal contents of chickens fed a diet containing 50% rye were significantly higher than control values 4, 6, and 8 days after feeding began. When chicks were fed a diet containing both 10% lactose and 50% rye, C. perfringens counts in cecal contents were lower than in chickens fed 50% rye only at 6 days after feeding began. Results led to the conclusion that dietary lactose is effective in reducing the cecal colonization of C. perfringens.

Animal Feed↗
PubMedDate not supplied

Effects of different levels of oocyst inocula of Eimeria acervulina, E. tenella, and E. maxima on plasma constituents, packed cell volume, lesion scores, and performance in chickens.

The effects of different levels of oocyst inocula of Eimeria acervulina, E. tenella, or E. maxima on plasma carotenoids, total plasma lipids, total plasma proteins, packed cell volume (PCV), bird performance, and coccidial lesion scores were determined in male Hubbard chickens. Each test consisted of an uninfected treatment and either four levels (E. tenella and E. maxima) or five levels (E. acervulina) of inocula. Carotenoids and lipids were significantly (P < or = 0.05) depressed by E. acervulina starting at 10(2) oocysts per bird, whereas 10(4) and higher inoculum levels significantly depressed plasma protein. Carotenoids and lipids were significantly depressed by E. tenella beginning at 10(4) oocysts per bird, whereas 10(2) oocysts per bird and greater levels significantly depressed plasma protein. E. maxima significantly depressed carotenoids and lipids beginning at 6.7 x 10(2) oocysts per bird and plasma protein at 6.7 x 10(4) oocysts per bird. PCV was depressed by E. acervulina and E. tenella starting at 10(4) oocysts per bird but was not affected by E. maxima. Weight gain was significantly depressed by E. acervulina beginning at 10(5) oocysts per bird, by E. tenella at 10(4) oocysts per bird, and by E. maxima at 6.7 x 10(4) oocysts per bird. Coefficients of determination (R2) were highest for carotenoids (0.96-0.99), followed by lipids (0.93-0.96), weight gain (0.89-0.91), feed:weight gain ratio (0.89-0.91), and protein and PCV (0.65-0.92). Results demonstrated that plasma carotenoids and lipids were excellent response variables for measuring the effects on broiler chickens of each of the Eimeria spp. tested.

Animals↗
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Effect of Eimeria tenella infection on the production of Salmonella enteritidis-contaminated eggs and susceptibility of laying hens to S. enteritidis infection.

Experiments were conducted to determine the effect of Eimeria tenella infection on the production of Salmonella enteritidis-contaminated eggs and susceptibility of egg-laying hens to S. enteritidis infection. The dose of sporulated oocysts of E. tenella used in the present study was 2 x 10(5) per chicken. When hens were infected with 10(6) colony-forming units (CFU) of S. enteritidis, E. tenella infection resulted in a significant increase (P < 0.05) of S. enteritidis contamination in the shells of fresh eggs but not in the egg contents of fresh eggs and stored eggs. Significant effects of coccidial infection on the contamination of eggs (shells and contents) were not observed when hens were infected with 10(4) CFU of S. enteritidis. Surface-disinfected eggs pooled within each week from individual chickens infected with 10(4) CFU of S. enteritidis and E. tenella showed significantly (P < 0.05) more S. enteritidis contamination in eggshells, but not in egg contents, than did those from hens infected with S. enteritidis alone. Coccidial infection resulted in a significant increase of S. enteritidis in the cloacal swabs of hens infected with 10(4) CFU of S. enteritidis. In all the experiments, chickens infected with S. enteritidis and E. tenella showed significantly higher positive rates and counts of cecal S. enteritidis than did chickens infected with S. enteritidis alone. No significant differences of S. enteritidis-positive rates in ovary, oviduct, liver, and spleen were noted whether the hens were infected with a combination of E. tenella and S. enteritidis or with S. enteritidis alone.

Animals↗
PubMedDate not supplied

Effect of ochratoxin A on Salmonella typhimurium-challenged layer chickens.

Eleven-day-old chickens received 10(8) colony-forming units Salmonella typhimurium orally for 2 consecutive days. The next day, the 13-day-old chickens were given a high dose of ochratoxin A (3 mg/kg) orally. The number of S. typhimurium in both the duodenal and cecal contents of chickens administered with high doses of ochratoxin A increased significantly when compared with control birds. Ochratoxin A was shown to be one of numerous factors that affect the susceptibility of chickens to salmonellae colonization.

Administration, Oral↗
PubMedDate not supplied

Value of low-dose gallium-67 imaging in detection of non-Hodgkin's lymphoma recurrence.

We evaluated the usefulness of low-dose Ga-67 scintigraphy as a diagnostic tool for the detection of non-Hodgkin's lymphoma recurrence. Forty-six patients were included in this retrospective study. Anterior and posterior whole body images were obtained two or three days after the injection of 74 MBq of Ga-67. Inter- and intraobserver variability in scintigraphic imaging interpretation was analyzed using the kappa (kappa) statistics. Ga-67 scintigraphy allowed correct detection of recurrence in 18 of 22 events (sensitivity, 82%), and excluded relapse in 34 of 39 events (specificity, 87%). The positive predictive value was 0.78 and negative predictive value 0.89. All cases involving superficial lymph nodes (10/ 10) could be detected by Ga-67. Chest lesions were diagnosed with a sensitivity of 86% (6/7), bone and soft tissue 83% (5/6), and abdomen 80% (8/10). The sensitivity and specificity of CT were 91% (22/24) and 67% (8/12), respectively. In abdominal lesions, ultrasonography had sensitivity and specificity of 93% (14/15) and 94% (15/16), respectively. Kappa (kappa) statistics demonstrated good to strong inter- and intraobserver agreement in the interpretation of Ga-67 scintigraphy. The diagnostic results of low-dose Ga-67 scans, currently applied in Japan, were similar to those reported by the authors using high doses of 296 MBq to 370 MBq. Ga-67 scintigraphy, even at low dose, is useful in the detection of non-Hodgkin's lymphoma recurrence.

Adult↗
PubMedDate not supplied

Salmonella enteritidis contamination of eggs from hens inoculated by vaginal, cloacal, and intravenous routes.

Laying hens were inoculated intravaginally (IVg) once (IVg-single) or three times (IVg-triple), intracloacally (IC), or intravenously (IV) with Salmonella enteritidis (SE) phage type 4. Eggs tested were significantly (P < 0.05) fewer positive in group IC than in other groups. SE was recovered from egg contents in the groups IVg-single (9.6%), IVg-triple (4.2%), and IV (11.5%). IVg and IC inoculation resulted in colonization of the cloaca and lower portions of the oviduct but not the portion above the isthmus, whereas IV inoculation resulted in colonization of the entire oviduct. Only IV inoculation resulted in colonization of the ovary. In group IV, SE was recovered from three of six eggs found in the oviduct at necropsy, but in other groups, SE was not recovered from 53 eggs in the oviduct. The results suggested that the SE infection of vagina resulted in a frequent incidence of contaminated eggs and that SE adhered to the eggs from the contaminated vagina might pass through shells and shell membranes.

Animals↗