Biomedical subjects
Publications and source records attributed to H Ohta.
The authors presented a rare case of huge gravitation abscess. 67Ga scintigraphy was useful in the evaluation of the extent and activity of the disease. CT showed clearly the location and shape of the abscess. Enhanced MRI showed vertebral lesions as characteristic geographic and ring-like enhancement.
Unusual pulmonary uptake of 111In-chloride (111InCl3) was recognized in a patient with aplastic anemia. A chest radiograph showed infiltrative shadow concordant with 111InCl3 uptake, and autopsy revealed pulmonary aspergillosis. To our knowledge, there is not an extensive literature on 111InCl3 uptake in pulmonary aspergillosis.
To investigate the influence of cerebral hypoperfusion on learning behaviours, we developed a novel rat cerebral hypoperfusion model, in which the bilateral internal carotid arteries were permanently ligated to reduce the cerebral blood flow, and examined its behavioural and histopathological consequences in comparison to those occurring after bilateral common carotid ligation. In the Morris water maze task, rats with common carotid ligation exhibited a learning deficit, whereas rats with internal carotid ligation exhibited normal learning. Both models exhibited significant learning impairments in the eight-arm radial maze task, although the impairment was less severe in internal carotid-ligated rats than in common carotid-ligated rats. The cerebral blood flow of rats with common carotid ligation was reduced significantly both two and 10 days after ligation, and was still below normal three months after ligation. A milder, but significant reduction in the cerebral blood flow was observed in internal carotid-ligated rats. Shrinkage of the optic nerves and a circadian activity rhythm desynchronized to the light/dark cycle were exhibited by the rats with common carotid ligation, whereas these parameters remained unaffected in the rats with internal carotid ligation, suggesting that permanent ligation of common carotid arteries but not internal carotid arteries impairs visual functions. The main pathological changes observed in the brain following common carotid ligation were rarefaction and gliosis of the white matter and neuronal loss in the hippocampal CA1 region. On the other hand, the rats with internal carotid ligation had no significant brain damage. Chronic treatment with idebenone (1.5 and 15 mg/kg/day), a cerebral energy metabolism enhancer, over a three-month period, commencing five days after ligation, ameliorated the impairment of water maze learning in rats with common carotid ligation. The treatment also significantly improved the learning impairment in the radial maze task of internal carotid-ligated rats. Idebenone had no effect on the histopathological changes that followed cerebral hypoperfusion. It is concluded that cerebral hypoperfusion induced by permanent internal carotid ligation impairs the working memory without causing pathological damage to the brain tissues and the visual system, and the learning impairment can be ameliorated by a cerebral energy metabolism enhancer. These findings have the clinical implication that a reduction in blood flow may be an important factor that causes or exacerbates cognitive decline in dementias.
We recently reported the existence of a trans-acting factor (SPB) in Rhodobacter sphaeroides that repressed the expression of the puf operon during illumination. SPB was somewhat homologous to HvrA of Rhodobacter capsulatus, but these proteins appear to have functionally different properties. We now report an analysis of the flanking region of spb in the genome of R.sphaeroides, and we show that spb is a positional counterpart of hvrA of R. capsulatus. The region directly downstream of spb was found to contain three genes, two of which were highly homologous to orf5 and ahcY in R. capsulatus. However, a gene corresponding to hvrB, which controls the expression of orf5 and ahcY in R. capsulatus, was absent in R. sphaeroides. The level of the transcript of ahcY did not change in cells grown under photosynthetic and by respiratory conditions. By contrast, orf5 was transcribed at a higher rate in photosynthetically grown cells under high-intensity light than under low-intensity light, indicating features of transcription different from those in R. capsulatus. A third gene, orf318, which was absent in the corresponding region of R. capsulatus, encoded an amino acid sequence that was significantly homologous to the consensus sequence of RfaI and RfaJ of E.coli, which are glycosyl transferases involved in the synthesis of lipopolysaccharide. orf318 was transcribed in the opposite direction to ahcY, and at only a low level, under all conditions tested.
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Antigenic domain 1 (AD-1), located between amino acids 608 and 625 of human cytomegalovirus (CMV) gB protein, is the major domain recognized by neutralizing antibodies. Amino acids 552 to 630 are essential for the binding of neutralizing antibodies. We developed an enzyme-linked immunosorbent assay (ELISA) to detect antibodies against a fusion protein containing amino acid residues 549 to 644 of the gB polypeptide and maltose binding protein (MBP). Of 180 seropositive samples, 106 (58.9%) showed positive immuno-reactivity against the fusion protein. None of the seronegative samples reacted with the fusion protein. Among 57 seropositive individuals typed for HLA, subjects with HLA-DR9 had a higher positive rate against the fusion protein (13/14=92.9%) than those without HLA-DR9 (25/43=58.1%). In addition, subjects with HLA-DR15 had a lower positive rate against the fusion protein (7/16=43.3%) than those without HLA-DR15 (31/41=75.6%). Mean OD values of HLA-DR15-positive individuals were significantly lower than those of HLA-DR15-negative individuals. Thus, among CMV-infected individuals, HLA-DR9 may be associated with responders for neutralizing antibodies and HLA-DR15 may be associated with non/low-responders.
A novel estrogen receptor, estrogen receptor beta (ERbeta), has recently been cloned from a rat prostate cDNA library. In bone, which is an important target tissue of estrogen, ER alpha has been reported to be present preferentially in osteoblasts, but the mechanism of action of estrogen in bone is still not known. In the present study, we examined expression of ERbeta mRNA in bone. Expression of ERbeta mRNA was evident in primary osteoblastic cells isolated from 1-day-old rat calvaria and rat osteosarcoma cells (ROS 17/2.8), and its level was higher than that of ER alpha mRNA. When osteoblastic cells were cultured for 28 days to induce differentiation into mature osteoblasts capable of forming bone nodules, ERbeta mRNA was constantly and highly expressed during the entire culture period. In contrast, the level of ER alpha mRNA was very low at the beginning of culture and it gradually increased during the differentiation of osteoblastic cells. Various tissues including bone were isolated from 8-week-old rats of both sexes, and total RNA was extracted to compare the tissue distribution of expression levels of ERbeta mRNA. In cancellous bone of the distal femoral metaphysis and lumbar vertebra, expression of ERbeta mRNA was obvious, and its level was equivalent to those in the uterus and testis, but lower than those in the ovary and prostate. The level of ERbeta mRNA in femoral cortical bone was lower than that in cancellous bone. There was no appreciable differences between female and male rats in the distribution and expression levels of ERbeta mRNA in bone. These results indicate that ERbeta mRNA is highly expressed in osteoblasts in rat bone, suggesting that there is a distinct mechanism of estrogen action mediated by ERbeta in bone.
The possible induction of a metallothionein (MT)-like Cadmium (Cd) binding protein (MT-like Cd-BP) was investigated in rat testis after oral Cd administration. Male Wistar rats were given Cd by oral administration (20 mgCd/kg, for 10 weeks), while the experimental controls were given Cd by intraperitoneal (i.p.) injection (2 mgCd/kg). Cd concentration increased in the testes after both administrations. However, much more Cd (about 4 times) accumulated in the tests of rats receiving oral Cd administration than in rats receiving Cd ip injection (experimental control). Meanwhile, MT-like Cd-BP decreased dramatically in the testes after Cd i.p. injection compared to that in the testes of untreated control rats. However, this testicular MT-like Cd-BP after oral Cd administration increased significantly up to about 1.4 times of the amount found in the testes of untreated control rats. Inhibition of glutathione S-transferase (GST) activity and decreased glutathione (GSH) in the testes was not observed in rats after oral Cd administration. However, enzyme activity and GSH concentration were inhibited and decreased significantly in the testis by Cd toxicity after Cd i.p. injection. These results indicate that testicular MT-like Cd-BP, assumed to be MT and to be hardly inducible by Cd, is an inducible protein corresponding to increased Cd accumulation in the testis without damage by Cd toxicity after oral Cd administration.
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The influence of complete revascularization on long-term outcome of patients with multivessel coronary artery disease undergoing percutaneous transluminal coronary angioplasty (PTCA) was determined by analysis of 10-year survival in 167 consecutive patients treated at Juntendo University Hospital during 1984-1993. Forty-nine patients were completely revascularized and 118 had incomplete revascularization according to the anatomical classification. Among patients with anatomically incomplete revascularization, 56 were categorized as functionally adequate revascularization and 62 as functionally inadequate revascularization according to Faxon's criteria. Baseline characteristics showed incompletely revascularized patients had a higher incidence of prior myocardial infarction triple-vessel disease and/or chronic total occlusion in at least one lesion. The 10-year survival was slightly better in patients with complete (100%) than in those with incomplete revascularization (79%), but not statistically significant (p = 0.089). Event-free survival was not significantly different between the two groups. However, the need for coronary artery bypass surgery was higher in the incomplete revascularization group than that in the complete revascularization group (100% vs 81%, p = 0.013). The influence of the degree of functional revascularization on outcome was not clear in the present study. Long-term survival appeared to be better in patients with complete revascularization than that in patients with incomplete revascularization, but even in the latter, coronary artery bypass grafting in the later period could improve outcome. The effect of functional revascularization status should be further investigated in a larger population.
We investigated the hemodynamic, renal, and hormonal effects of cyclosporin A (CyA) treatment (6 mg/kg per day) for 4 weeks in 12 patients with nephrotic syndrome (8 women: 4 men, aged 36-66 years, 3 cases of focal glomerular sclerosis: 9 cases of membranous nephropathy). To evaluate the effects of CyA on the diurnal variation of blood pressure (BP), 24-h non-invasive BP monitoring was performed using model ABPM-630 (Nihon Colin, Tokyo, Japan) before and during CyA treatment. As indices of hemodynamics, intra-arterial pressure was monitored and cardiac output was measured by the dye-dilution technique using a cuvette at 0 and 4 weeks after treatment. CyA ameliorated urinary protein excretion and hypoproteinemia from 3.5 +/- 0.9 to 2.2 +/- 0.7 g/day, and serum protein concentration from 4.9 +/- 0.2 to 5.5 +/- 0.2 g/dl after 4 weeks' treatment. Endogenous creatinine clearance, 24-h urinary sodium excretion, and plasma renin activity decreased significantly at 1 week. CyA treatment raised casual BP from 122 +/- 4/75 +/- 2 to 140 +/- 5/87 +/- 3 mmHg after 1 week and to 146 +/- 4/90 +/- 2 mmHg after 4 weeks. Before treatment 24-h ambulatory BP monitoring showed BP reduction at night (116 +/- 5/68 +/- 3 mmHg) compared to the daytime (124 +/- 5/75 +/- 2 mmHg). The diurnal variation of BP disappeared during CyA treatment; mean daytime and nighttime pressures were 135 +/- 4/81 +/- 2, 132 +/- 5/80 +/- 3 mmHg at 1 week and 139 +/- 5/83 +/- 3, 131 +/- 6/80 +/- 3 mmHg at 4 weeks, respectively. On hemodynamic study; a 4-week treatment with CyA increased mean arterial pressure from 91 +/- 3 to 104 +/- 3 mmHg, total peripheral resistance index from 2.1 +/- 0.1 to 2.5 +/- 0.1 x 10(3) dyne.sec.cm-5.m2, and unchanged heart rate and cardiac index. Serum Mg concentration decreased from 2.1 +/- 0.1 to 1.7 +/- 0.1 mg/dl. These results suggest that CyA-induced hypertension is characterized by the loss of nocturnal decline in blood pressure, which is accompanied by volume retention after 1 week and systemic vasoconstriction after 4 weeks.
A 34-year-old patient with follicular lymphoma who was treated with CHOP followed by COPP for 3 years, became resistant to treatment in December 1993. Histological findings and surface markers of cervical lymph node cells revealed no change from previous findings. Tumor cell involvement of bone marrow was also observed by molecular analysis of DNA fragments with bcl-2 oncogene and J-H gene probes. Following 2 courses of salvage chemotherapy with NOAC-M regimen (novantrone, cytarabine and methylprednisolone), There was an 88% reduction of tumor mass on computed tomographic findings. Through the use of polymerase chain reaction analysis of residual cells with the bcl-2 translocation, we confirmed the in vivo purging of tumor cells from bone marrow and we harvested marrow cells for autologous transplantation. After high-dose chemotherapy (HDC) with ranimustine, cisplatin, etoposide and cyclophosphamide followed by bone marrow transplantation (BMT), complete remission was achieved. The patient has survived for 16 months and remains disease free. The standard chemotherapy regimen for advanced low grade non-Hodgkin's lymphoma has not yet been defined. Although we must follow this patient carefully to determine the effect of HDC with BMT for a long time, this seems to be an effective complementary treatment for patients responding to conventional salvage regimens.
An epidermoid tumor inside the Meckel's cave is rare. The symptoms caused by this tumor include trigeminal neuralgia, facial hypesthesia and paresis of the 3rd, 4th and 6th nerves. A case of epidermoid tumor inside Meckel's cave was presented. A 54-year-old female who had complained of 3rd nerve palsy with right facial hypesthesia since 3 years before was referred to our clinic. Magnetic resonance imaging (MRI) showed the tumor at Meckel's cave. The tumor removal was performed using the orbito-zygomatic approach. To avoid injury of the internal carotid artery and nerves inside the cavernous sinus, removal of the tumor inside the capsule was carried out leaving the capsule. Postoperatively, the tumor removal was confirmed by MRI and improvement of the 3rd and the 5th nerve palsy was obtained three months after surgery. This case suggests that the capsule of the tumor inside the Meckel's cave should be allowed to remain to avoid injury of the adjacent 4th, 5th and 6th nerves and of the internal carotid artery.
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