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Biomedical subjects

K Ohno

Publications and source records attributed to K Ohno.

At least 433 records · Page 24Linked to original sources
PubMed1993

Low incidence of seizures in patients with chronic subdural haematoma.

A total of 129 patients treated for chronic subdural haematoma were studied retrospectively to evaluate the incidence of seizures. None of 73 patients who were given prophylactic antiepileptic drug treatment developed seizures. Only two of 56 patients not given prophylaxis, developed early postoperative seizures. In these two, surgical technique was thought to be responsible. One patient developed complex partial seizures preoperatively. The incidence of seizures was therefore low, and similar to that previously reported for minor head injury. This study suggests that routine use of antiepileptic prophylaxis is not justified in patients with chronic subdural haematoma caused by minor head injuries, or other causes when there are no additional lesions present on CT scans.

Adolescent↗
PubMed1993

In vivo observation of subendocardial microvessels of the beating porcine heart using a needle-probe videomicroscope with a CCD camera.

We developed a portable needle-probe videomicroscope with a charge-coupled device (CCD) camera to visualize the subendocardial microcirculation. In 12 open-chest anesthetized pigs, the sheathed needle probe with a doughnut-shaped balloon and a microtube for flushing away the intervening blood was introduced into the left ventricle through an incision in the left atrial appendage via the mitral valve. Images of the subendocardial microcirculation of the beating heart magnified by 200 or 400 on a 15-in. monitor were obtained. The phasic diameter change in subendocardial arterioles during cardiac cycle was from 114 +/- 46 microns (mean +/- SD) in end diastole to 84 +/- 26 microns in end systole (p < 0.001, n = 13, ratio of change = 24%) and that in venules from 134 +/- 60 microns to 109 +/- 45 microns (p < 0.001, n = 15, ratio of change = 17%). In contrast, the diameter of subepicardial arterioles was almost unchanged (2% decrease, n = 5, p < 0.01), and the venular diameter increased by 19% (n = 8, p < 0.001) from end diastole to end systole. Partial kinking and/or pinching of vessels was observed in some segments of subendocardial arterioles and venules. The percentage of systolic decrease in the diameter from diastole in the larger (> 100 microns) subendocardial arterioles and venules was greater than smaller (50-100 microns) vessels (both p < 0.05). In conclusion, using a newly developed microscope system, we were able to observe the subendocardial vessels in diastole and systole.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Molecular and genetic analyses of two patients with Pearson's marrow-pancreas syndrome.

Pearson's syndrome, a rare and fatal disorder characterized by refractory sideroblastic anemia and pancreatic insufficiency in infancy, is classified into mitochondrial cytopathies. To understand the molecular and genetic bases of this disorder, we have investigated the mitochondrial respiratory chain enzymes and the mitochondrial DNA (mtDNA) in two Japanese patients with Pearson's syndrome. Immunoblot analysis from various tissues showed the different grades of defects in the subunits of respiratory enzyme complexes. The analyses of mtDNA showed that the deletion in patient 1 spanned 4977 bp from the ATPase 8 gene to the NADH dehydrogenase 5 gene between 13-bp direct repeats, whereas the deletion in patient 2 spanned 3151 bp from the transfer RNA(His) gene to the cytochrome b gene unrelated to any repeated sequences. The deleted mtDNA was heteroplasmic in all the analyzed tissues, but the proportions of deleted mtDNA were quite different. We observed a tendency for the tissue with low percentages of normal-sized mtDNA to show low contents of complex I subunits. Analysis of the entire sequence of both patient's mtDNA showed several nucleotide substitutions including alteration of the initiation codon of the NADH dehydrogenase 5 gene. Some of these nucleotide substitutions might contribute to the phenotypic expression of Pearson's syndrome synergistically with the deletion.

Anemia, Sideroblastic↗
PubMed1993

Altered sensitivities to potential inhibitors of cholesterol biosynthesis in Niemann-Pick type C fibroblasts.

Cultured fibroblasts from patients with Niemann-Pick disease type C (NP-C) are characterized by the lysosomal accumulation of unesterified cholesterol and the inability of low-density lipoprotein (LDL) to stimulate cholesterol esterification, in addition to impaired LDL-mediated down-regulation of LDL receptor activity and cellular cholesterol synthesis. Although a defect in the transport of cholesterol from lysosomes to other intracellular membrane sites has been suggested, it is unclear how cells regulate the levels of cellular sterols and whether their membrane cholesterol requirements are satisfied or not. We studied the esterification of exogenously added cholesterol, total levels of cellular cholesterol and cholesteryl ester, cholesterol synthesis from a two-carbon precursor, and sensitivities to potential inhibitors of cholesterol biosynthesis in proliferating NP-C cells. We observed the following: (a) esterification of [3H]cholesterol was decreased but the total amount of cellular cholesteryl ester was not decreased; (b) synthesis of cholesterol from [3H]acetate was increased; and (c) cells were hypersensitive to cholecalciferol, an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase, and were resistant to filipin, which binds to membrane sterols and presumably damages the membrane. The results indicate that NP-C cells depend on the cellular cholesterol synthetic pathway for their proliferation, but the plasma membrane sterols are presumably decreased. The altered sensitivities to potential inhibitors of cholesterol biosynthesis should be a useful marker for diagnosis and genetic studies.

Acetates↗
PubMed1993

Establishment and characterization of a feline large granular lymphoma cell line expressing interleukin 2 receptor alpha-chain.

A feline large granular lymphocyte (LGL) cell line was established from a cat with an alimentary-form lymphoma. This cell line, designated as FGL, had many large azurophilic granules in the cytoplasm, which were typical to LGL cells. Proviral genome of feline leukemia virus was detected in the chromosomal DNA of FGL cells, and reverse transcriptase activity was also demonstrated in the culture supernatant. Furthermore, we found expression of interleukin 2 (IL-2) receptor alpha-chain on the cell surface of FGL and its natural killer activity against human erythroblastic leukemia cell line, K562.

Animals↗
PubMed1993

Progressive external ophthalmoplegia and myositis.

We reported a senile male patient with progressive external ophthalmoplegia (PEO) and myositis. The ophthalmoplegia was severe, but other neuromuscular features were nearly normal. Muscle enzymes in serum were moderately elevated. Autoimmune, endocrinological or malignant diseases were not observed during the previous 4 years. Pathology of non-weak limb muscles biopsied twice was consistent with active inflammatory myopathy. The ragged-red or cytochrome c oxidase-negative fibers, which are a hallmark of mitochondrial myopathy with PEO, were not increased in comparison with age-matched control muscles. Analysis of mitochondrial DNA in muscle by the Southern blot method did not reveal any deletions. It was concluded that the inflammatory myopathy, myositis clinically localized at the ocular muscles, is an important and distinct disorder in PEO.

Aged↗
PubMed1993

Calcitonin gene-related peptide in the efferent system of the inner ear. A review.

Many calcitonin gene-related peptide-like immunoreactive (CGRP-IR) fibers were found in the vestibular end-organs and the cochlea of rats. CGRP-IR fibers in the vestibular end-organs originated in the bilateral cell groups dorsolateral to the genu of the facial nerve. These fibers formed a fiber plexus at the base of the sensory epithelia in the maculae of the otolith organs and the ampullae of the semicircular canals, and formed synaptic contacts with the nerve chalice on type I vestibular sensory cells. CGRP-IR fibers in the cochlea originated in the ipsilateral lateral superior olivary nucleus. Most of them existed in the inner spiral bundle under the inner hair cells, and formed synaptic contacts with afferent terminals on the inner hair cells. These findings suggest a postsynaptic modulation of CGRP on the vestibular and cochlear information at the level of type I vestibular sensory cells and the inner hair cells.

Animals↗
PubMed1993

[Dermatological evaluation of a flame retardant, hexabromocyclododecane (HBCD) on guinea pig by using the primary irritation, sensitization, phototoxicity and photosensitization of skin].

As one of the projects in the safety evaluation of chemical constituents in common house-hold products, effects of hexabromocyclododecane (HBCD) were evaluated by primary skin irritation, skin sensitization, phototoxicity and photosensitization using guinea pigs. Primary skin irritation was not observed in HBCD emulsified in distilled water by the Draize test method. Skin sensitization test was carried out according to the maximization test method of Magnusson and Kligman. For this test, HBCD was dissolved in olive oil to give 5, 0.5 and 0.05%. When induction of sensitization occurred, challenged doses of 0.005, 0.05, 0.5 and 5% of HBCD (dissolved in acetone) were applied to its respective sensitized groups. The results showed that the induction dose of greater than 0.5% and the challenge dose of greater than 0.05% elicited a positive response. The increase in the concentration of induction and challenge doses did not further increase the percentage of positive response or the intensity of skin response. Phototoxicity test was carried out with 0, 0.5 and 5% of HBCD dissolved in acetone. Phototoxicity was not observed at all HBCD concentration tested. Photosensitization test was performed according to the Sato's adjuvant-strip method. The skin sensitization and challenge reaction doses were 5 and 0.5% and 0 and 0.5% HBCD (dissolved in acetone), respectively, and no positive reaction was observed. It is clear from the foregoing results that HBCD is a mild skin allergen.

Animals↗
PubMed1993

[Evaluation of immunotoxicity tests using cyclosporin A-treated rats: the International Collaborative Immunotoxicity Study II (cyclosporin A)].

Immunotoxicological effects of cyclosporin A (CsA) were studied by enhanced histopathological and functional tests in rats. Male F344 rats were orally administered with CsA in doses of 0, 2.5, 10, and 40 mg/kg/day for 28 successive days. Hematological examination revealed that the CsA treatment brought about a marked dose-dependent decrease in the number of WBCs, which was attributed to a decrease in the number of lymphocytes. In the femoral bone marrow, a significant reduction in the number of nucleated cells was observed, which was attributed to a decrease in the number of lymphocytes and erythroblasts. Histopathologically, diminution of thymic medullas, appearance of tangible body macrophages in thymic cortices, and calcification and basophilic changes in kidneys were observed in the middle and high dose groups. Immunohistological examination with anti-rat T lymphocyte antibody showed a decrease in the number of T cells at the periarterial lymphatic sheaths in the spleens. As for the functional tests, CsA treatment remarkably reduced the PFC number even in the low dose group. The Con A response of spleen cells was decreased in the middle and high dose groups. The STM response was reduced only in the high dose group. The NK activity was little affected. Thus, in the CsA-treated F344 rats, the enhanced histopathological and some functional tests which were proposed by ICICIS, were found to be useful to detect damages to the immune system.

Administration, Oral↗
PubMed1993

Application of hydroxyapatite-coated implants as support for palatal lift prostheses in edentulous patients with cleft palate: a clinical report.

A palatal lift prosthesis (PLP) is a prosthetic speech aid used to compensate for palatopharyngeal incompetence. However, it requires dental abutments to facilitate its function. In two edentulous patients with cleft palate, hydroxyapatite-coated dental implants were used to increase PLP retention. In both cases, palatopharyngeal closure was obtained and PLP function was deemed effective, as determined by speech evaluation and nasal air flow measurements, for more than 3 years. This treatment is useful for enhancing the retention of a PLP in patients who have few or no remaining natural tooth abutments.

Adult↗
PubMed1993

[Primary mediastinal tumors in children--comparison with mediastinal tumors in adults].

During the past 43 years, 628 patients with a primary mediastinal tumor underwent surgical operation in our institution. Of those patients, 106 patients (16.9%) were children of 15 yr of age or less and 522 patients (83.1%) were adults. 47 (44.3%) of the 106 children had neurogenic tumors, while 21 patients (19.8%) had a teratoma. 189 (36.2%) of the 522 adults had thymoma and 89 patients (17.1%) had teratoma. In the 106 children there were 71 benign tumor patients (66.9%) and 35 malignant tumor patients (33.1%). There were 277 (53.1%) benign and 245 (46.95) malignant tumors in the 522 adults. The adults had significantly more malignant tumors than the children (p < 0.01). In our series of malignant mediastinal tumors in children, 14 patients (13.3%) had a lymphoma and 11 patients (10.5%) had a neuroblastoma. On the other hand, in the adults, 127 patients (24.3%) had a thymoma and 66 patients (12.6%) had a lymphoma. Regarding benign mediastinal tumors, in children, 30 patients (28.5%) had a ganglioneuroma and 19 patients (18.0%) had a teratoma. In the adults, 68 patients (13.0%) had a teratoma and 62 patients (11.9%) had a thymoma. In the clinical manifestation, 51 child patients (48.1%) and 191 adult patients (36.6%) were asymptomatic. As symptoms due to compression or direct invasion to adjacent structures, dyspnea was seen in 16 child patients (15.1%), and chest pain occurred in 59 adult patients (11.3%). Dyspnea was significantly more common in children than in in adults (p < 0.01). Emergency operations were performed in children more than in adults.

Adolescent↗
PubMed1993

[Six cases of epidural abscess probably caused by epidural block and examination by gadolinium-MRI imaging].

We treated six cases of epidural abscess caused probably by epidural block. Three patients were given only chemotherapy and the other three underwent surgical treatment. Four patients were cured completely, but bilateral paresis in the lower limbs persisted in two patients. The symptoms at onset, laboratory findings, imaging findings including MRI and CT, treatment methods and prognosis were reported. Accelerated blood sedimentation rate, positive CRP results and abnormal findings at the site of the catheter insertion appeared to be important initial signs for the early discovery of epidural abscesses. The route of infection, selection of treatment methods, methods of prevention and examination by Gadolinium-MRI imaging were also discussed.

Abscess↗
PubMed1993

The effect of aging on the healing of hydroxylapatite implants.

The purpose of this study was to investigate the effect of aging on the healing process after insertion of a hydroxylapatite (HA) implant into bone. Three groups of eight male Wistar rats, aged 6 weeks (young group), 12 weeks (adult group), and approximately 2 years (old group) were used in this experiment. Two implants were placed into the tibia of each rat. The animals were killed 7, 14, 28, and 56 days after implantation, and 15-microns, hematoxylin-eosin-stained, undecalcified sections were prepared. The healing process was examined histologically, and histomorphometric measurements were made by a computer-based image analyzer to quantify the percentage of HA-bone contact and trabecular bone in the medullary cavity. In the young group, new trabecular bone formed actively around the HA implant and good HA-bone contact was achieved more rapidly than in the adult group. In the old group, both the quantity of newly formed trabecular bone around the implant and the extent of HA-bone contact were less than in the other groups. The results suggest that the rate and volume of new bone formation around implants decrease with increasing age.

Aging↗
PubMed1993

[Advances in molecular genetics of the Niemann-Pick group of diseases].

Recent advances in molecular genetics of the Niemann-Pick group of diseases are reviewed. Types A and B Niemann-Pick disease are characterized by a deficiency of one of lysosomal hydrolases, i.e. acid sphingomyelinase. The enzyme was partially purified from a large amount of urine and the cDNA clones, encoding acid sphingomyelinase, were cloned. The gene encoding the enzyme has been localized at the region p 15.1-p 15.4 of chromosome 11 by analysis of a somatic cell hybrid and in situ hybridization. Several mutations, causing deficient sphingomyelinase activity, were identified among patients with different ethnic backgrounds. The expression experiments revealed that the mutations responsible for type A cause no detectable residual enzyme activities, while mutations responsible for type B, cause relatively higher residual enzyme activity of 2% to 40 %. Biochemical abnormalities in Type C Niemann-Pick fibroblasts are characterized by normal acid sphingomyelinase activity, accumulation of intracellular cholesterol and defective esterification of exogenously added cholesterol. The basic defect is still unknown. Similar abnormalities were observed in mutant mouse strains, BALB/c and C57 BL/Ks. The mutant C57BL/Ks mouse, which was found in Japan, has been characterized as a sphingomyelinosis and the genetic locus, spm, has been assigned to chromosome 18. By transferring a single human chromosome to the immortalized cell line, we have found human chromosome 18 can reduce intracellular cholesterol accumulation. More recently, Pentchev and co-workers found linkage of type C to human chromosome 18. It is highly probable that the spm and human type C mutations involve the same gene. Molecular cloning of the defective gene in muman and mouse mutation become practically possible.

Animals↗
PubMed1993

[Clinical application of 99mTc-DTPA-galactosyl serum albumin in hepatobiliary disease].

A clinical study with 99mTc-DTPA-galactosyl serum albumin (99mTc-GSA) was performed in 10 patients with hepatobiliary disease. In this study, scintigraphic data and images with 99mTc-GSA were compared with several serological liver function tests, the hepatic blood perfusion index and image quality using 99mTc-DTPA-human serum albumin (99mTc-HSA). Dynamic and serial hepatic images were obtained over a 20 min period after 99mTc-GSA injection, and time activity curves from the heart and liver were generated. The blood clearance index (HH15), and the hepatic uptake index (LHL15) were calculated from each curve of the heart and liver, respectively. In addition, using two compartment fitting, the blood clearance (KH1, KH2) index was calculated, and using exponential fitting, the hepatic uptake index (KL) was calculated. The mean HH15 in LC group and non-LC group was 0.81 +/- 0.05, 0.64 +/- 0.10, respectively. The mean LHL15 in LC group and non-LC group was 0.79 +/- 0.04, 0.91 +/- 0.06, respectively. There were significant differences between non-LC group and LC group in HH15, and LHL15, KH1 and KL. There were also significant correlations of KH1 with HH15, and KL with LHL15. Parameters of 99mTc-GSA showed significant correlations with various liver functions. 99mTc-GSA scintigraphy showed clearer liver images in hepatobiliary diseases than 99mTc-HSA. These results suggest that 99mTc-GSA scintigraphy is useful in estimating preserved liver function and hepatic morphology.

Adult↗
PubMed1992

Differences of draining lymph node cell proliferation among mice, rats and guinea pigs following exposure to metal allergens.

Contact sensitivities of three well known metal allergens (nickel sulfate, potassium dichromate and cobalt chloride) were examined using the local lymph node assay in CBA/N mice, F344 rats and Hartley guinea pigs. The effect of various species sera on lymph node cell (LNC) proliferation was also investigated. Exposure to potassium dichromate and cobalt chloride induced significant LNC proliferative responses in the three species. The LNC responses to potassium dichromate in the rats were higher than those in the mice and guinea pigs. Mice exhibited the highest response to cobalt chloride among the three species, whereas, exposure to nickel sulfate failed to induce a marked LNC proliferation. Increased draining lymph node weights and LNC numbers were also observed following exposure to the metal salts. However, these parameters were less sensitive compared with the LNC proliferative response. There was a large difference in the lymph node weight between individual guinea pigs. The [methyl-3H]thymidine incorporation into LNC of each species cultured in the presence of the homologous serum in vitro was lower than in the presence or absence of fetal calf serum. However, there was no significant difference in stimulation indices among the different culture conditions. The local lymph node assay may be performed in rats as well as in mice for the detection of metal allergens.

Allergens↗
PubMed1992

[Assessment of a coaxial system accommodated to a 0.035 inch guide wire in superselective hepatic angiography and embolization].

A special coaxial catheter system accommodated to a 0.035 inch guide wire was recently developed. The four-part coaxial system is composed of a central 0.035 inch flexible guide wire, a 4-French inner catheter (straight, 90 cm in length), a 6-French outer catheter (fork-shaped, 60 cm in length), and a hemostatic valve. The 4 French inner catheter is large enough in diameter to allow a larger volume of contrast medium and greater amount of embolic material than the earlier coaxial system. Using this coaxial catheter system, we performed successful superselective hepatic arteriography and embolization in 44 patients with malignant hepatic tumors. Catheterization of the celiac and superior mesenteric arteries with the 6 French outer catheter was easy, and the angiogram obtained was very distinct. The 4 French inner catheter was easily and safely advanced into the segmental hepatic artery, and even common hepatic arteriography with this catheter provided clear images on conventional cut films. Therefore, in most cases, both angiography and embolization can be accomplished using this coaxial system alone.

Aged↗