Biomedical subjects

S Tanabe

Publications and source records attributed to S Tanabe.

At least 325 records · Page 18Linked to original sources

PubMed1990

[Reconstruction of radicular arteries in the total replacement of thoracoabdominal aorta].

A technique of reconstructing low intercostal, high lumbar arteries and Adamkiewicz artery is described to prevent paraplegia following operations on the thoracoabdominal aorta. A graft with a side branch is anastomosed proximally and a side branch to the distal thoracic aorta after reinforcement of the stumps under the partial bypass. Applying a clamp on the main graft, flow through the side branch and true lumen of the aneurysm is reestablished and bypass is terminated. The main graft, extended with a Y-graft, is anastomosed to common iliac arteries after proximal suture-ligation to perfuse the lower extremities. Splanchnic arteries are reconstructed according to DeBakey's technique which is followed by trimming of the thoracoabdominal aorta incising longitudinally with a clamp applied on the 1st side branch. Edges of the trimmed aneurysm are sutured to the slit of the graft from the right common iliac artery reconstructing intercostal, lumbar arteries and Adamkiewicz artery from the level of L2 upwards to T4 or more. As a final step, the graft is sutured to the 1st side branch allowing perfusion distally to the right lower extremity and the main graft to the splanchnic arteries and left lower extremity after division of a Y-graft right branch. The technique minimizes ischemic time for reconstruction of the aortic branches and enables complete reconstruction of the radicular arteries.

Aorta, Abdominal↗

PubMed1990

[Two cases of perioperative coronary vasospasm following ASD closure and OMC].

Two cases of perioperative coronary spasm following ASD closure and OMC are reported. A 36-year-old female had been diagnosed of vasospastic angina and another 47-year-old female patient was diagnosed of effort angina for 99% stenosis of the right ventricular branch preoperatively. Both patients suffered from coronary vasospastic attack and ventricular fibrillation several times within 17 hours postoperatively. Although the coronary dissolution was obtained finally following aggressive cardiac massage, administration of spasmolytic agents, such as NTG, lidocaine, DBcAMP and the start of IABP, the resolution was stormy due to the hemodynamic derangement. To prevent the coronary spastic episode, it is suggested, for patients of possible coronary spasm, to avoid arousal stimulation and to administer spasmolytic agents prophylactically within the first postoperative day.

Adult↗

PubMed1990

[Effects of BY-1949 on three kinds of experimental amnesia in rodents].

The possible anti-amnesic effects of a dibenzoxazepine derivative, BY-1949 (3-methoxy-11-methyldibenz[b,f] [1, 4] oxazepine-8-carboxylate), were examined using the three learning paradigms. In the one-trial passive avoidance task in mice, BY-1949 (1-30 mg/kg, po) and aniracetam (3-30 mg/kg, po) reversed the shortening of the response latency in the retention test produced by exposure to 100% CO2 immediately after the acquisition trial. In the two-way active avoidance task in rats, BY-1949 (10, 30 mg/kg, po) reversed the decreased avoidance rate produced by the hypoxia treatment (5% O2:95% N2). In the radial-arm maze task in rats, BY-1949 (10 mg/kg, po) and aniracetam (10, 30 mg/kg, po) improved the impaired correct choices induced by scopolamine (0.25 mg/kg, ip). These results suggest that BY-1949, as well as aniracetam, exerts some improvement effects on experimental amnesia.

Amnesia↗

PubMed1990

[Familial cardiac myxoma with multiple and contralateral recurrence].

This report described a familial recurrent cardiac myxoma involving mother and daughter. The mother, at 27 year of age, had developed recurrent multiple myxomas in both left and right atrium and right ventricle 4 years after surgical excision of left atrial myxoma. Excision was successful and remains well without signs of recurrence 9 years postoperatively. In an asymptomatic 13-year-old daughter, a recurrent left atrial myxoma was found 3 years after the excision of right atrial myxoma by echocardiographic follow-up at 6 month intervals. Excision of left atrial myxoma was performed and histology showed the essentially the same findings as primary myxoma without signs of malignancy. From an experience of this familial recurrent myxoma and a review of 38 cases of 17 familial cardiac myxoma, it is recommended that wide excision of tumor including surrounding tissues, thorough search for multiple heterotopic tumors at surgery, close postoperative echocardiographic follow-up for at least 5 years, and examination of skin and breast tumor, and endocrine disorder for "complex" myxoma.

Adolescent↗

PubMed1990

[Significance of raphe in congenitally bicuspid aortic valve].

The decrease of rheumatic aortic regurgitation (AR) is observed due to the relative increase of non-rheumatic aortic valvular diseases since 1980. Among 240 patients who had undergone aortic valve replacement (AVR) including combined valvular diseases up to March 1989, the congenitally bicuspid aortic valve was responsible for AR and stenosis (AS) in 33 patients (13.8%) and were divided according to the presence of a raphe. In the raphe (+) group (n = 15), infective endocarditis (IE) (n = 5), prolapse of the aortic valve, mainly non-coronary cusp (n = 5), and thickening with contraction of cusp (n = 4) were the cause of AR. Calcification of the cusp was seen in 2 older (greater than 59 yrs) patients. In the raphe (-) group (n = 18), IE (n = 2), contraction of cusps (n = 2) in the relatively younger (less than 48 yrs) were the cause of AR. Rest of the patients exhibited severe AS due to the calcification of cusps except a case who showed IE with AR in the calcified cusp. Although not generally recognized, the bicuspid valve with a raphe, less tendency to deposit calcium, is an important cause of pure AR severe enough to warrant AVR. The bicuspid valve without raphe, as already recognized, prones to develop severe calcification and AS in later life.

Adult↗

PubMed1990

[The surgical treatment of endomyocardial fibrosis of the left ventricle--the first surgical case report in Japan].

A 66-year-old man with an ECG finding of an elevation of R in leads V5-6 and a calcified space occupying lesion in the apex of the left ventricle on echocardiography admitted for the evaluation of recent onset of shortness of breath and palpitation on exertion. Cineangiography showed an obliteration and accumulation of RI activity in the apex of the left ventricle on TI-201 scintigraphy and a neoplasm of the heart was suspected. Resection of a tumor from apical incision followed by the left atrial approach necessitated the replacement of mitral valve and confirmed the diagnosis of endomyocardial fibrosis. Heart failure persisted and the expired 2 years after surgery due to the gastrointestinal infection. An experience suggested the resection of a mass from the left atrial approach is possible and recommended to prevent the occurrence and persistence of heart failure in case the diagnosis is established preoperatively.

Aged↗

PubMed1990

[Left coronary ostial stenosis in aortitis syndrome--patch mounted graft technique for proximal anastomosis].

Late restenosis or total occlusion of proximal aortic anastomosis frequently occurs due to intimal proliferation in aortitis CABG patients although successful early postoperatively. A Gore-Tex patch (diameter 20 mm) mounted grafts to LAD and CX with a single ostium was sutured in the inflammatory aorta to prevent late occlusion in a 40-year-old female patient. Postoperative CAG a month after showed a patent graft to LAD and improved exercise treadmill test. Graft to Cx occluded due to competed flow from LAD. No aneurysm was found in the proximal anastomosis. Tissue nonpermeable Gore-Tex mounted graft is considered to be suitable for CABG in aortitis patients with the high incidence of late occlusion.

Adult↗

PubMed1990

[Reconstruction of skull base by omentum transplantation].

The majority of skull base tumors have been considered inoperable not because of the difficulty of surgical removal, but for lack of reliable methods to reconstruct the skull base following extensive removal of those tumors. In this report a trial fo reconstruction using a transplanted omentum is described. A free sheet of vascularized omentum was taken via laparotomy and transplanted into the skull base in four patients who had undergone extensive resection of skull base tumors. The transplanted omentum served satisfactorily as a barrier to prevent CSF leakage and subsequent infection and was considered to be a reliable material to reconstruct large defects in the skull base. The advantage of the omentum is its applicability in covering defects of all sizes and shapes. The omentum also contains various factors to promote tissue adhesion, such as angiogenic factors and fibroblastic growth factors. Furthermore, it can be expected to prevent secondary infections of the transplanted area, and as being a defense organ in the abdominal cavity. Practical methods to harvest and transplant the free vascularized omentum are described, and four cases of patients who have undergone these procedures are reported.

Adolescent↗

PubMed1989

Involvement of bcl-2 gene in Japanese follicular lymphoma.

A t(14;18) (q32;q21) chromosome translocation is closely associated with the follicular lymphoma, which is prevalent in the United States, and the t(14;18) causes the juxtaposition of a bcl-2 gene on chromosome 18 with an immunoglobulin heavy-chain gene locus on chromosome 14. Genomic DNAs from 30 Japanese patients with follicular lymphoma were examined for the molecular features by Southern blot hybridization. Using probe b for the major breakpoint cluster region of a bcl-2 gene, the rearrangements were detected in eight patients. Six of the eight patients had breakpoints located within the major breakpoint region, while two had breakpoints outside this cluster region but within the region of the 7.5-kb SstI fragment containing the probe b sequence. In two patients, pFL-2 probe detected the bcl-2 gene rearrangements that occurred near or within the minor breakpoint cluster region. These ten patients had a rearranged JH-containing fragment that migrated with the rearranged bcl-2 fragment. In the other 20 patients, these two chromosome 18-specific DNA probes did not detect the bcl-2 rearrangements. Compared with studies performed in the United States, the statistical analysis indicates a significant difference in frequency of the bcl-2 gene rearrangements near or within the major breakpoint cluster region (P = 0.0027) and the minor breakpoint cluster region (P = 0.029). However, the distribution difference of these events was not significant.

Blotting, Southern↗

PubMed1989

Critical evaluation of polychlorinated biphenyl toxicity in terrestrial and marine mammals: increasing impact of non-ortho and mono-ortho coplanar polychlorinated biphenyls from land to ocean.

Residues of potentially toxic non-ortho chlorine substituted coplanar 3,3',4,4'-tetra-,3,3',4,4',5-penta-, 3,3',4,4',5,5'-hexachlorobiphenyl and their mono- and di-ortho analogs 2,3',4,4',5-penta, 2,3,3',4,4'-penta-, 2,3,3',4,4',5-hexa- and 2,2',3,3',4,4'-hexa-, 2,2',3,4,4',5-hexachlorobiphenyl) were determined in humans, dogs, cats (terrestrial), a finless porpoise (Neophocoena phocoenoides--coastal), Dall's porpoises (Phocoenoides dalli, dalli), Baird's beaked whales (Berardius bairdii) and killer whales (Orcinus orca--open ocean). Among the coplanar polychlorinated biphenyl (PCB) congeners, the concentration of the di-ortho congeners was the highest and the non-ortho congeners was the lowest. However, all three coplanar PCBs occurred at significantly higher levels than toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The relative bioconcentration and metabolic capacity of terrestrial and marine mammals to these chemicals, suggest that the toxic threat of coplanar PCBs increases from land to ocean, but the reverse is true for PCDDs and PCDFs. The toxic threat of coplanar PCBs to higher aquatic predators such as cetaceans was principally assessed by 2,3,7,8-T4CDD Toxic Equivalent Analysis which is based on the induction of arylhydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD). Analysis indicates, in particular, that the bioaccumulation of toxic 3,3',4,4',5-penta- and 2,3,3',4,4'-pentachlorobiphenyls in carnivorous marine mammals is a cause for considerable concern.

Animals↗

PubMed1989

Biogenesis of plasma lipoproteins in rat hepatoma McA-RH7777: importance of diffusion-mediated events during cell growth.

Cultured McA-RH7777 rat hepatoma cells actively synthesize and secrete plasma lipoproteins. However, synthesis of [14C]triglyceride declines monotonically throughout the early growth period and remains low in postconfluent cultures; and net secretion of [14C]triglyceride is 10-fold more efficient in logarithmically growing cultures than in postconfluent cultures. Secretion of apolipoproteins associated with very low density and low density lipoproteins is selectively reduced in postconfluent cultures. The temporal reductions in [14C]triglyceride production are related more strongly to increasing cell concentration (cells/cm3 medium) than to increasing cell density (cells/cm2 growth surface). We have allowed cells to grow either retained within small circular corrals or unrestricted in culture dishes. When seeded at equal density (10(4) cells/cm2) but at one-fifth the cell concentration, corralled cells synthesize twice as much [14C]triglyceride per cell after 2 and 4 d, and are 10 times as efficient in [14C]triglyceride secretion by 6 d of growth, as noncorralled cells. When seeded at equal cell concentration (10(5) cells/dish) but at 5 times the cell density, corralled cells are only 20% less efficient at [14C]triglyceride synthesis and secretion than noncorralled cells. Conditioned medium depresses synthesis and secretion efficiency of [14C]triglyceride. Orotic acid exposure also inhibits synthesis of [14C]triglyceride and secretion of certain [35S]apolipoproteins in early cultures, but it has no significant effect on late cultures. We conclude that diffusion-mediated events are important regulators of triglyceride and apolipoprotein production in growing rat hepatoma cells, but that events associated with formation of cell-to-cell contacts play a minor role in regulation of plasma lipoprotein biogenesis.

Albumins↗

PubMed1989

Persistency of highly toxic coplanar PCBs in aquatic ecosystems: uptake and release kinetics of coplanar PCBs in green-lipped mussels (Perna viridis Linnaeus).

The bioaccumulation potential of three highly toxic coplanar PCB isomers [3,3',4,4'-tetrachlorobiphenyl (T(4)CB); 3,3',4,4',5-pentachlorobiphenyl (P(5)CB); and 3,3',4,4',5,5'-hexachlorobiphenyl (H(6)CB)] was investigated using green-lipped mussels (Perna viridis Linnaeus) as a bioindicator, through a transplantation experiment at two locations in Hong Kong waters. By contrast to the relatively rapid uptake and release of many other PCB isomers, the non-ortho chlorine substituted coplanar PCB congeners exhibited slow uptake and clearance. The kinetic parameters of coplanar PCBs based on lipid weight-related data, and the degree of bioaccumulation based on the proportion of coplanar PCBs in total PCBs in mussels, clearly indicate that coplanar PCBs are highly bioaccumulative in lower organisms. On the assumption that mussels are unlikely to be particularly unusual with respect to their bioaccumulation of coplanar PCBs, it appears most likely that these highly toxic and persistent PCB congeners are concentrated by all aquatic organisms, and may reach higher consumers (including humans) in quantities of toxicological concern.

Journal Article↗

PubMed1989

Seasonal variations of organochlorine insecticide residues in air from Porto Novo, South India.

Air samples collected from Porto Novo (11 degrees 29' N, 79 degrees 46' E), Tamil Nadu State, South India from December, 1987 to January, 1989 were analysed to determine the seasonal variations of the levels of organochlorine insecticides such as HCH (BHC) and DDT. Both these insecticides showed higher levels from August to January, although this trend was more marked in HCH than DDT, reflecting the application of HCH largely, and probably small quantities of DDT during the flowering season of rice. The alpha-HCH was detected as a dominant isomer for all seasons monitored followed by gamma-HCH. Among DDT compounds, p,p'-DDT was the highest except in dry season (January to April) when p,p-DDE showed higher percentage. The levels and percentage composition of these insecticides recorded in the present study may aid in interpreting the role of a 'point source' area since India is one of the countries still using the persistent organochlorine pesticides in large quantities.

Journal Article↗

PubMed1989

Polychlorinated biphenyls (PCBs) in sediments in Hong Kong: a congener-specific approach to the study of coplanar PCBs in aquatic ecosystems.

Patterns of contamination by polychlorinated biphenyls (PCBs) were investigated in fourteen samples of coastal sediments from Hong Kong. Congener-specific analyses revealed nine sediment samples from Junk Bay to contain PCBs at concentrations ranging from 31 to 2200 ng g(-1) dry weight, concentrations generally increasing with distance north in the Bay. By contrast, five sediments from the Tolo area to the north-east of Hong Kong exhibited total PCB levels of only 6.6 to 45 ng g(-) dry weight. The patterns of relative abundance of PCB congeners in the northern Junk Bay sediments suggested the existence of ongoing source(s) of PCBs in this area; biphenyls of lower chlorination were present at high concentration in these samples. Three coplanar PCBs (3', 4, 4'-tetrachlorobiphenyl; 3,3',4,4',5-pentachlorobiphenyl; and 3,3',4,4',5,5'-hexachlorobiphenyl) were found to be present in Junk Bay sediments; these are highly toxic and are cause for concern in aquatic environments. The abundance of the three coplanar PCBs in the sediments studied was similar to that in commercial PCB mixtures, suggesting that these congeners are not enriched over other PCBs by the sediments of coastal ecosystems. It is concluded that the preferential enrichment of coplanar PCBs occurs in the biosphere, rather than in sediments.

Journal Article↗

PubMed1989

Temporal trends of organochlorine residues in lizard goby Rhinogobius flumineus from the river Nagaragawa, Japan.

PCBs, DDTs, HCHs (BHCs) and Chlordane compounds were analyzed in lizard goby, Rhinogobius flumineus collected from the River Nagaragawa, Japan during the period from 1968 to 1986. High residue levels of PCBs, DDTs and HCHs were found during late 1960s and early 1970s. From early 1970s, the residual levels started declining and the lowest levels were reached during the 1980s. In 1986, the residual concentrations of PCBs, DDTs and HCHs were 150, 6.2 and 2.2 ng/g which were 100, 100 and 210 times less than the highest values recorded during the years 1969, 1968 and 1970 respectively. Unlike these pollutants, residual concentrations of chlordane compounds have showed about a 5-fold increase from 5.4 ng/g in 1970 and reached the level of 25 ng/g in 1986.

Journal Article↗

PubMed1989

Immunohistochemical analysis of peripheral T-cell lymphoma in Japanese patients.

The authors immunohistochemically analyzed the phenotype of 40 cases of peripheral T-cell lymphoma, including 12 adult T-cell leukemia/lymphoma (ATL) cases. Molecular genetic analysis of the T-cell receptor beta-chain and immunoglobulin heavy chain genes were also applied to cases of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD)-like lymphoma and so-called Lennert's lymphoma. Twenty non-ATL lymphomas expressed a helper/inducer phenotype, whereas only one extranodal case expressed a suppressor/cytotoxic phenotype. Three cases had a CD4-CD8- phenotype, and two cases a CD4+CD8+phenotype. No specific relationship between morphologic characteristics (LSG classification) and phenotype was found among non-ATL lymphomas. Six of eight AILD-like lymphomas had a helper/inducer phenotype. Monoclonality of neoplastic T-cells was demonstrated in six of the seven cases of AILD-like lymphoma by molecular genetic analysis. Two cases of Lennert's lymphoma also showed a helper/inducer phenotype and rearrangement of the T-cell receptor beta-chain gene. Serologically defined ATL cases had a helper/inducer phenotype except in one case that expressed both CD4 and CD8. None of the ATL cases had the CD7 antigen in this study using WT 1 as a CD7 antibody, which is in contrast with the non-ATL lymphomas in which 13 of 25 cases expressed CD7. CD25, strongly detectable in all ATL cases, was negative or weakly expressed in non-ATL lymphomas. These facts suggest that non-ATL and ATL are in the different biologic state, probably resulting from the integration of human T-cell leukemia virus type I (HTLV-I), although both are derived from helper/inducer T-cells.

Antigens, Differentiation, T-Lymphocyte↗

PubMed1989

Age-related central and baroreceptor impairment in female Sprague-Dawley rats.

To determine whether baroreflex sensitivity changes with age, we compared drug-induced reflex responses in 2- and 9-mo-old female Sprague-Dawley rats anesthetized with urethan-chloralose. Baroreflexes were stimulated by elevating or lowering blood pressure with intravenous infusions of phenylephrine or sodium nitroprusside. Reflex responses in heart rate and sympathetic nerve activity during phenylephrine infusions were weaker in 9- than in 2-mo-old rats, as were reflex tachycardia during sodium nitroprusside infusion and decreases in heart rate and sympathetic nerve activity elicited by electrical stimulation of the left aortic depressor nerve. Afferent aortic nerve activity was also appreciably lower in 9-mo-old rats at pressures greater than 130 mmHg but did not differ between rat groups at normotensive pressures. These results suggest that baroreflex sensitivity in 9-mo-old rats can be characterized as follows: 1) impaired at pressures greater than 130 mmHg but still adequate at normotensive pressures, and 2) all reflex arc components may be impaired.

Afferent Pathways↗

PubMed1989

[Parasagittal meningioma with unusual venous drainage manifesting through peritumoral hemorrhage. Case report].

A 63-year-old female was admitted with a 5-day history of left hemiparesis. Computed tomography showed an enhanced mass with perifocal edema in the right frontal parasagittal region and an irregular-shaped, high-density mass anterior to the tumor. Right carotid angiography disclosed the prominent middle meningeal artery (MMA) to be the main feeding vessel of the tumor. In the venous phase, the superior sagittal sinus (SSS) was obstructed and a dilated middle meningeal vein (MMV) drained downward to the sphenoparietal sinus. Left carotid angiography demonstrated similar findings. There was a filling defect in the lumen of the MMV due to the MMA running within the vein. At surgery, careful manipulation was required, as the venous blood in the left MMV drained not only from the tumor but also from the anterior half of the SSS. The left MMA was found to run through the cavity of the dilated MMV. The SSS was invaded by tumor. There was an old hematoma cavity containing xanthochromic fluid in the brain parenchyma adjacent to the tumor. Histological examination showed meningothelial meningioma. The postoperative course was uneventful, although the right MMV was opacified on carotid angiography. It was suspected that obstruction of the SSS by tumor invasion had caused dilatation of the bilateral MMV and peritumoral hemorrhage due to disturbance of the venous drainage.

Cerebral Hemorrhage↗