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Biomedical subjects

K Inamura

Publications and source records attributed to K Inamura.

At least 19 recordsLinked to original sources
PubMed1992

[Image processing of early gastric cancer cases].

Computer image processing was used to enhance gastric lesions in order to improve the detection of stomach cancer. Digitization was performed in 25 cases of early gastric cancer that had been confirmed surgically and pathologically. The image processing consisted of grey scale transformation, edge enhancement (Sobel operator), and high-pass filtering (unsharp masking). Gery scale transformation improved image quality for the detection of gastric lesions. The Sobel operator enhanced linear and curved margins, and consequently, suppressed the rest. High-pass filtering with unsharp masking was superior to visualization of the texture pattern on the mucosa. Eight of 10 small lesions (less than 2.0 cm) were successfully demonstrated. However, the detection of two lesions in the antrum, was difficult even with the aid of image enhancement. In the other 15 lesions (more than 2.0 cm), the tumor surface pattern and margin between the tumor and non-pathological mucosa were clearly visualized. Image processing was considered to contribute to the detection of small early gastric cancer lesions by enhancing the pathological lesions.

Adult↗
PubMed1992

User and manufacturer's requirements for IMAC standardization in Japan.

Many radiologists and radiological technologists understand that Picture Archiving and Communication Systems (PACS) are useful not only for image management but also for improving the quality of patient care. However, such systems have not yet been widely installed in hospitals. In order to determine why radiologists have not installed a PACS in their hospitals, we carried out a written survey of 400 Japanese hospitals asking them to describe the current image management activities, the problems inherent in PACS and the problems related to standardization. 216 hospitals responded, and the following suggestions were compiled concerning possible improvements to PACS. (1) PACS benefit needs to be improved with respect to patient care. (2) The cost of PACS should be reduced. (3) The system should be easier to operate and should save time. (4) Standardization is needed to allow simplified, cost-effective networking. We also carried out a written survey of 25 PACS and related equipment manufacturers asking them to describe the opinions inherent in current PACs and the problems related to standardization. Ten manufacturers responded, and the various suggestions were compiled concerning possible improvements to the PAC system.

Japan↗
PubMed1992

Current status of Image Save and Carry (IS&C) standardization.

Image Save And Carry (IS&C) was planned to be an off-line information system for transmission and exchange of medical images and information between a medical facility's different divisions as well as between other hospitals. The IS&C committee defines file format for magneto-optical disk, the data format and representation, media compatibility and data security and technological assessment. A 'zone management method' which contributes to a rapid access of data in the recording media is used for IS&C file management. The IS&C standard holds as much conformation as possible in order to coordinate with ACR-NEMA (American College of Radiology-National Electrical Manufacturers' Association) and MIPS (Medical Information Processing Systems) standards. The IS&C data format is based upon the ACR-NEMA/MIPS standard. A major difference between the ACR-NEMA/MIPS standard and IS&C standard is that the IS&C standard is expected to serve for recording all kinds of medical information (e.g., diagnostic reports, endoscopic images and electrocardiograms), including X-ray images. Applications to PACS, teaching files, personal electronic health and medical records are promising. The booklet of IS&C standard will be published in the spring of 1992 by the IS&C committee.

Computer Communication Networks↗
PubMed1992

Oral diagnostic reporting and synchronized image filing using magneto-optical disks.

An experimental radiologic reporting system has been developed and tested. The rewritable and compact magneto-optical disk (MOD) is applied to storing medical images with oral diagnostic reports of these radiologic images. The disk is 5.25 inches in diameter, has 600 MB memory capacity, is erasable, light and compact. Advantages are simultaneous recording of radiologic images and their oral reports by radiologists, and application to circulation of media inside the hospital as well as to filing of medical images. The MOD has a multimedia function of communication and filing. When medical images are taken and stored, oral interpretation by radiologists can be simultaneously added. Physicians can get information of the images and their reports by oral speech at the same time in front of computer workstation. Furthermore, integration of a voice recognition capability is now being undertaken.

Image Processing, Computer-Assisted↗
PubMed1992

Report of a study using phantom materials, and clinical experience with simultaneous radio-hyperthermotherapy.

Simultaneous radiohyperthermotherapy (SRH) is a combined hyperthermia-radiation therapy in which irradiation is given during heating. Mutual interference between the high energy radiotherapy system (Toshiba LMR-15A) and the 13.56 MHz capacitive heating system (Omron HEH-500C) was tested with phantom materials prior to a clinical trial with SRH. The energy and flatness of irradiation were not affected by the heating system within the range of clinical use. The high energy radiotherapy system did not affect the increase or distribution of temperature during simultaneous treatment. The results of this phantom study indicated that these apparatuses would not produce clinically significant mutual interference during SRH. A clinical trial was performed on a 57-year-old woman with postoperative recurrence of rectal cancer. This is the first reported clinical case treated with true SRH in which external irradiation was administered during mid capacitive heating. Twelve SRH treatments were performed on the recurrent lesion at a frequency of twice a week for six weeks using the apparatuses described above. There was a significant reduction in pain after treatment. The tumor marker carcinoembryonic antigen (CEA) level decreased after treatment. On CT images taken after treatment, the tumor site became a low density area which indicated necrosis. There were no side effects. These results suggest that further clinical study of SRH should be performed to clarify its advantages.

Body Temperature Regulation↗
PubMed1992

[Clinical and CT-findings in hemiballismus].

We studied the correlation between clinical and CT-findings in 33 cases with hemiballismus. Of these 33 cases, 4 cases were examined by the authors and 29 cases were obtained from the literature. Cerebrovascular disease was present in 27 cases and the localization of the lesion was examined with CT. Of these 10 cases had lesions in the subthalamus, while 17 cases had lesions outside the subthalamus. In 6 cases, the location of the lesion was not recognized on CT. In cases with lesions outside the subthalamus, 11 cases had lesions in the putamen, 10 cases had lesions in the caudate. Therefore the lesion were largely located in the striatum. Typical hemiballismus was seen in 16 cases. In this group, 6 cases had lesions in the subthalamus, 5 cases had lesions in the putamen, and 3 cases had lesions in the caudate. Hemiballismus accompanied by hemichorea was seen in 17 cases. In this group, while 9 cases had hemichorea with ballismus, and 5 out of 9 cases had lesions in the caudate, 4 cases had lesions in the putamen. Thus, all lesions were located in the striatum. Eight out of 17 cases had hemiballismus with chorea. In these 8 cases, 4 cases had lesions in the subthalamus, these were 2 cases in the putamen, and 2 cases had lesions in the caudate. When all cases were examined in terms of clinical manifestations, 10 cases were considered to have lesions in the caudate and 7 out of 10 cases involved chorea. Ten cases had lesions in the subthalamus, while 6 out of 10 cases showed typical hemiballismus.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Infarction↗
PubMed1991

[Magneto-optical disk filing system for oral diagnostic reports and their synchronized images].

The rewritable and compact media of magneto-optical disk (MOD) is firstly applied to store medical images with spoken reporting. The MOD has multi-media function of communication and filing. Our system is optimized in terms of recording length of speech based upon our clinical research. The results will have influences over the future PACS. One of their examples is possibility of multimedia PACS with images, speeches and demographic data. Another example is prevention of dispersion of images which have no interpretations by radiologists. Our next step is to recognize filed speech in background processing for printing reports.

Optical Storage Devices↗
PubMed1991

Low frequency components of the body's center of gravity and blood circulation.

The purpose of this study was to clarify how low frequency components of the body's center of gravity, mainly 1 minute waves (1-MWs), are related to the mechanism of compensation for the venous blood pooling in the legs during static standing in humans. The 1-MWs of foot pressure center, oscillations of body circumferences and other parameters were analyzed with cross-power spectral analysis. The 1-MW of the calf's blood volume propagated to the chest via the venous system. This was inversely synchronized with the 1-MW of the body's center of gravity. It was speculated that muscular pumping of the calf related to the 1-MW of the body's center of gravity might be compensating for the venous blood pooling in the legs.

Adult↗
PubMed1990

Accumulation of calcium in substantia nigra lesions induced by status epilepticus. A microprobe analysis.

Status epilepticus of sufficient duration (greater than 30 min) causes a unique lesion of substantia nigra pars reticulata (SNPR), and of globus pallidus (GP). This lesion, which encompasses a pan-necrotic destruction of neurons and glial cells seems to develop during ongoing seizures. We decided to investigate if the lesion is accompanied by net calcium accumulation. Seizures of 20 and 60 min duration were induced by the administration of flurothyl, and the tissue was frozen in situ either at the end of the seizure periods, or after recovery periods of 15 or 120 min. The total calcium and potassium contents of caudoputamen, neocortex, GP and SNPR were measured using particle induced X-ray emission (PIXE) in the microprobe mode. Seizures of 20 min duration did not cause net accumulation of calcium. When the duration of seizures was extended to 60 min the results varied depending on the location. In caudoputamen, which does not incur neuronal damage, no calcium accumulation was observed. In GP and SNPR, such a rise was unequivocally demonstrated, with calcium content increasing to about 150% of controls. The increase in calcium correlated to a decrease in potassium content. It is concluded that epileptic cell death occurs pari passu with accumulation of calcium although it cannot be stated that this accumulation is the cause of the cell death. It is speculated that seizures increase the permeability of the blood-brain barrier to calcium, and that enhanced blood to tissue transfer increases the calcium load of metabolically strained cells.

Animals↗
PubMed1990

Effects of arginine derivatives on soluble guanylate cyclase from neuroblastoma N1E 115 cells.

The effects of L-arginine (Arg) derivatives on soluble guanylate cyclase from neuroblastoma N1E 115 cells were examined. The Arg derivatives were modified at the -NH2, -COOH, C alpha-proton or guanidino group of Arg. Among the synthesized derivatives, eight compounds, i.e. the 5-(dimethylamino)-1-naphthalenesulfonyl (DNS) ones, especially N-cyclohexyl-2-(N-DNSamino)-5-guanidino-2-methylvaleramide and 1-[2-(N-DNSamino)-2-(2-imino-1,2,3,4,5,6-hexahydropyrimidin- 4-yl)acetyl]- piperidine, were found to inhibit the activity of crude guanylate cyclase in the 105,000 g supernatant fraction of the cell homogenate. The enzyme, partially purified by a column of Chelex 100 Na+, was also inhibited by these eight compounds. The mode of the inhibition was competitive. The Ki values were in the range of 2-8 microM for the enzyme in the 105,000 g supernatant fraction and 3-16 microM for the partially purified enzyme, in the presence of Mg2+ as a metal cofactor. In contrast, a new derivative, methyl 2-amino-5-guanidinovalerate (M Arg ME), as well as the Arg methyl ester (Arg ME) and Arg; were found to enhance the activity of the partially purified guanylate cyclase; KA values of M Arg ME, Arg ME and Arg were approximately 9, 4 and 3 microM respectively. From these results, the free guanidino group including 2-imino-1,2,3,4,5,6-hexahydropyrimidin-4-yl or 2-imino-1,2,3,4,5,6-hexahydropyrimidin-5-yl and modification of the --NH2 residue with a hydrophobic group such as DNS seemed to be essential for inhibition of the guanylate cyclase; however, the guanidino and --NH2 residue of Arg should be free for activation by these Arg derivatives.

Arginine↗
PubMed1990

A case of sclerosing lymphangitis of the lip.

A 62-year-old woman noted a cord-like swelling on the inner surface of her upper lip. A cross-section of the lesion showed a radial-shaped lumen surrounded by a thickened fibrous wall. Immunohistochemical staining with the anti-factor VIII-related antigen (FVIII-RAg) antibody was negative on the luminal surface and swollen wall, although the vasa vasorum in the swollen wall were positive. The lesion was thus considered to be of lymphatic origin; that is, it derived from a lymphatic collecting vessel. For the present case, the term 'lymphangiopathia obliterans' is considered appropriate. This is the second report of such a lesion appearing on the lip in the literature.

Antigens↗
PubMed1989

Seizure-induced damage to substantia nigra and globus pallidus is accompanied by pronounced intra- and extracellular acidosis.

Status epilepticus of greater than 30-min duration in rats gives rise to a conspicuous lesion in the substantia nigra pars reticulata (SNPR) and globus pallidus (GP). The objective of the present study was to explore whether the lesion, which encompasses necrosis of both neurons and glial cells, is related to intra- and extracellular acidosis. Using the flurothyl model previously described to produce seizures, we assessed regional pH values with the autoradiographic 5,5-dimethyl[2-14C]oxazolidine-2,4-dione technique. Regional pH values were assessed in animals with continuous seizures for 20 and 60 min, as well as in those allowed to recover for 30 and 120 min after seizure periods of 20 or 60 min. In additional animals, changes in extracellular fluid pH (pHe) were measured with ion-selective microelectrodes, and extracellular fluid (ECF) volume was calculated from the diffusion profile for electrophoretically administered tetramethylammonium. In structures such as the neocortex and the hippocampus, which show intense metabolic activation during seizures, status epilepticus of 20- and 60-min duration was accompanied by a reduction of the "composite" tissue pH (pHt) of 0.2-0.3 unit. Recovery of pHt was observed upon termination of seizures. In SNPR and in GP, the acidosis was marked to excessive after 20 and 60 min of seizures (delta pHt approximately 0.6 after 60 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Decrease of glutamate decarboxylase activity in substantia nigra and caudoputamen following transient hyperglycemic ischemia in the rat.

Glutamate decarboxylase (GAD) activity was determined in caudoputamen (CP), substantia nigra (SN), and cerebral cortex (CCX) after 19-22 h of recirculation following 10 min of transient ischemia in hyperglycemic rats, i.e., under the conditions when previously a pronounced nerve cell damage was demonstrated in both CP and SN. The present results demonstrate a decrease of GAD activity in SN by 30% and in CP by 22% and no change in CCX. No statistically significant change in GAD activity could be detected in SN, CP, or CCX 1,4, and 7 days following 10 min of ischemia in normoglycemic animals. The decrease of GAD activity in SN at the time preceding the onset of postischemic seizures suggests that there may be an imbalance between augmented excitatory and decreased inhibitory transmission in SN. We tentatively conclude that this may increase the probability of generalized seizures in the postischemic period following ischemia in hyperglycemic animals.

Animals↗
PubMed1989

[Effects of dihydrotestosterone on cultured hair papilla cells and localization of its receptors].

We have reported that cultured papilla cells (PC) grown by isolation and cultivation of human hair papillae show some biological characteristics. In the present study, localization of androgen binding proteins in PC and effects of dihydrotestosterone (DHT) on PC in vitro were examined. Cytochemical staining of PC using DHT-peroxidase conjugate gave positive reactions in the nucleo of PC originating from scalp- and axilla-hair papillae. The cultivation of PC with added DHT in media for two weeks showed increases 3H-thymidine uptake and 14C-proline uptake over that of dermal fibroblasts. These results suggest that androgen receptors exist in PC and that DHT in culture media induces an accelerating effect upon the DNA synthesis and protein synthesis.

Androgen-Binding Protein↗
PubMed1988

Pathogenesis of substantia nigra lesions following hyperglycemic ischemia: changes in energy metabolites, cerebral blood flow, and morphology of pars reticulata in a rat model of ischemia.

A spectacular spongiotic lesion, symmetrical in distribution and restricted to the pars reticulata of the substantia nigra (SNPR) has recently been described in hyperglycemic rats surviving 1-18 h after a brief period of transient ischemia. The purpose of this study was to clarify the pathogenesis of the lesion. In order to study whether the lesion was due to changes occurring during ischemia, local cerebral blood flow (l-CBF) and energy metabolites were measured in the substantia nigra (SN) and in other brain areas. Furthermore, brains were examined by light and electron microscopy immediately after ischemia and in the early recirculation period. Autoradiographic CBF measurements showed ischemia flow levels in the SN of 30-40% of control, similar in normo- and hyperglycemic rats. Thus, although ischemic, this structure had a considerable amount of residual flow. There was also a corresponding partial preservation of the adenylate energy charge. However, lactate levels were high, and in hyperglycemic subjects they rose to values previously described during status epilepticus (about 25 mumol/g). In hyperglycemic animals, neuronal alterations were consistently present in SNPR by the end of the 10-min period of ischemia. They included clumping of nuclear chromatin and subplasmalemmal clearing of the perikaryon. Some mitochondrial swelling was present in neuronal perikarya and in dendrites. The normal alignment of microtubules in the dendrites was disturbed, but there was no or only slight swelling of the dendrites. Aggregation of synaptic vesicles was a conspicuous finding in axonal terminals, which were also slightly swollen. Otherwise, the axons appeared largely spared. Microvessels looked quite intact. Similar cellular changes were observed in the early recovery period. Dendrites, however, started to swell, and their expansion finally caused the spongiotic appearance of the pars reticulata. The appearance of the dendritic lesions is strongly suggestive of transmitter-mediated ("excitotoxic") damage. However, it seems likely that the marked acidosis is injurious as well. We tentatively conclude that both mechanisms interact to give the final lesion. The results, and those previously obtained in epileptic seizures, suggest that mitochondria of SN neurons and neuronal processes are particularly prone to damage.

Animals↗
PubMed1988

Accumulation of calcium and loss of potassium in the hippocampus following transient cerebral ischemia: a proton microprobe study.

This study explored (a) whether postischemic accumulation of calcium in hippocampal neurons precedes or occurs pari passu with light microscopical signs of delayed neuronal necrosis, and (b) whether calcium initially accumulates in dendritic domains, presumed to have a high density of agonist-operated calcium channels. Transient ischemia of 10-min duration was induced in rats, and the animals were studied after 1, 2, 3, and 4 days of recovery. We measured total calcium and potassium contents in the stratum oriens, pyramidale, radiatum, and moleculare of the CA1 and CA3 sectors, using particle induced x-ray emission (PIXE) in the proton microprobe mode. The results showed significant accumulation of calcium and loss of potassium after 3 and 4 days of recovery in the CA1 sector, which developed neuronal necrosis, but not in the CA3 sector, which showed only occasional damage. In a few animals, calcium accumulation (and loss of potassium) was observed with no or only mild visible damage, but in the majority of animals the accumulation of calcium correlated to signs of neuronal necrosis. Since calcium accumulation was similar in all strata examined, the results failed to reveal preferential accumulation in dendritic or somal regions. Based on our results and those of Dux et al., we emphasize the possibility that delayed neuronal death is, at least in part, caused by increased calcium cycling of plasma membranes and gradual calcium overload of mitochondria.

Animals↗