[Wandering atrial pacemaker].
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Arrhythmia, Sinus↗
Biomedical subjects
M Sumida
Publications and source records attributed to M Sumida.
Cloning and expression of the gene of hemocytin, an insect humoral lectin which is homologous with the mammalian von Willebrand factor.
Invertebrate lectins play an important role in a non-specific self-defense mechanism, as invertebrates do not synthesize specific antibodies. We report the cloning of several overlapping cDNAs encoding the entire silkworm (Bombyx mori) lectin, which we propose to call hemocytin. The sequence (10477 bp) encoded 3133 amino acids. The characteristics features of the carbohydrate-recognition domain of C-type animal lectin were revealed at C-terminal sequence of hemocytin. When cDNA encoding this region was introduced into baculovirus vector, hemagglutinating activities were detected in the culture fluid of a recombinant virus-infected cells. These activities were inhibited by D-mannose, N-acetyl-D-galactosamine, and D-maltose which are haptenic saccharides of authentic hemocytin. Analysis of dot and Northern blot hybridization revealed that hemocytin gene was transcribed in hemocytes of the silkworm at larval-pupal metamorphosis and/or after the injection of Escherichia coli and lipopolysaccharide. After silkworm larvae were injected with C-terminal portion of hemocytin, aggregation of hemocytes was observed in the hemolymph. Hemocytin has significant homology with mammalian von Willebrand factor which involves in platelet adhesion to subendothelium. Also, hemocytin has a homologous region with coagulation factor V and VIII. These results suggest that hemocytin molecule is an adhesive protein and relates to hemostasis or encapsulation of foreign substances for self-defense.
Amino Acid Sequence↗
Demonstration of the venous systems with gadolinium-enhanced three-dimensional phase-contrast MR venography.
The purpose of this study was to evaluate the usefulness and advantages of gadolinium-enhanced three-dimensional phase-contrast MR venography for demonstrating the venous systems. The three-dimensional phase-contrast MR venography was performed with a velocity encoding gradient settings from 5 to 20 cm/s on 22 normal subjects. In 8 of normal subjects, gadolinium-enhanced phase-contrast MR venography was performed. 22 subjects (100%) had detectable flow in the sphenoparietal sinus, transverse sinus, basal vein, and internal cerebral vein. With a VENC setting at 10 cm/s, venous system was visualized selectively and clearly. Detection ratio in inferior petrosal sinus, superior petrosal sinus, and superior ophthalmic vein increased from 0% to 25%, from 28.6% to 62.5%, and from 28.6% to 37.5%, respectively, after administration of gadopentate dimeglumine. In conclusion, gadolinium-enhanced three-dimensional phase-contrast MR venography was useful for demonstrating the venous systems.
Adolescent↗
MRI of intracranial germ cell tumours.
We reviewed MRI findings in proven intracranial germ cell tumours in 22 cases, 12 of whom received Gd-DTPA. On T1-weighted images, the signal intensity of the tumour parenchyma was moderately low in 19 cases and isointense in 3; on T2-weighted images, it was high in all cases. Regions of different intensity thought to be cysts were found in 17 (77%): 7 of 12 patients with germinoma (58%) and in all other cases. Of the 13 patients with pineal lesions T1-weighted sagittal images showed the aqueduct to be obstructed in 5, stenotic in 7 and normal in 1. Strong contrast enhancement was observed in all 12 cases. Of the 14 patients with suprasellar lesions, 5 were found to have an intrasellar extension, and in 3 of these, the normal pituitary gland, which could be distinguished from the tumour, was displaced anteriorly. Ten patients (45%) had multiple lesions.
Adolescent↗
Surface anatomy scanning (SAS) in intracranial tumours: comparison with surgical findings.
We evaluated the usefulness of surface anatomy scanning (SAS) in intracranial tumours, comparing it with surgical findings. We examined 31 patients with brain tumours preoperatively. The tumours included 16 meningiomas, 8 gliomas, 4 metastases and 3 others. SAS clearly demonstrated the tumours, allowing them to be distinguished from the structures of the brain surface, including oedema, except in cases of metastasis. SAS clearly demonstrated large cortical veins. SAS is useful for three-dimensional delineation of the brain surface before surgery.
Brain↗
MRI of pineal region tumours: relationship between tumours and adjacent structures.
A variety of tumours may arise in the pineal region; accurate diagnosis is important in the selection of treatment and prognosis. A retrospective analysis of the MRI studies of 25 patients with pathologically proven pineal region tumours was performed, focused on the relationship between the tumour and neighbouring structures. Compression of the tectal plate was classified as expansive or invasive, and compression of the corpus callosum as inferior, anterior or posterior. In 10 of the 14 patients (71%) with germ cell tumours tectal compression was of the invasive type; 8 patients (57%) had multiple tumours and in 13 (93%) the tumor margins were irregular. Teratomas were readily diagnosed because of characteristic heterogeneous signal intensity. Pineal cell tumours were differentiated from germ cell tumours by their rounded shape, solid nature, sharp margins, and expansive type of tectal compression. Meningiomas were characterised by their falcotentorial attachments, posterior callosal compression, and a low-intensity rim on T2-weighted images. Gd-DTPA injection enabled clear demonstration of the site and extent of tumour spread and was useful in differentiating cystic and solid components. The appearances described, while not pathognomonic, are helpful in the differential diagnosis of pineal region tumours, and valuable in planning appropriate treatment.
Adolescent↗
Invasive aspergilloma of the frontal base causing internal carotid artery occlusion.
BACKGROUND: Aspergilloma of the nasal cavity or paranasal sinuses rarely extends through the skull base into the intracranial space. PATIENT: The patient was a 79-year-old man in a nonimmunosuppressive state who had an invasive aspergilloma of the base of the frontal lobe. CLINICAL COURSE: The patient, whose initial symptom was a visual disturbance, eventually developed an occlusion of the right internal carotid artery and died. The diagnosis was established by a transsphenoidal biopsy. CONCLUSIONS: A rare case of invasive aspergilloma of the frontal base is described with emphasis on the findings of low-intensity mass on the T2-weighted magnetic resonance imaging (MRI). The prognosis in this disease is very poor. Early diagnosis and surgical treatment, combined with postoperative antifungal drug therapy, would have improved the outcome.
Aged↗
Transovarian transmission of a foreign gene in the silkworm, Bombyx mori, by Autographa californica nuclear polyhedrosis virus.
We introduced a firefly luciferase gene, expressed under control of Drosophila heat shock protein gene promoter, into Autographa californica nuclear polyhedrosis virus (AcNPV). When the 5th instar larvae of the silkworm, Bombyx mori, were inoculated with the recombinant virus, luciferase activities were detected in the virus-infected larvae and pupae, and in the newly hatched larvae of the next generation. PCR amplification and Southern blot hybridization analysis demonstrated that the luciferase gene was transmitted through at least the F2 generation. In addition, the V-cathepsin gene, encoding a cysteine protease of AcNPV, was also detected in the DNA of all individuals of the F2 generation. These results show that AcNPV can be utilized as vector for the transovarian transmission of foreign genes in the silkworm.
Animals↗
[Comparison of temperatures from 7 points in the patients under intraperitoneal hyperthermic perfusion].
We measured the temperatures from 7 points in the patients under intraperitoneal hyperthermic perfusion (IPHP), associated with induced hypothermia. The temperatures from the 7 points were as follows, pulmonary artery blood temperature (PAT), bladder temperature (BT), sole deep body temperature (ST), forehead deep body temperature (FT), external aural cannal temperature (EAT), esophageal temperature (ET), and rectal temperature (RT). We studied the relationship between PAT and the other 6 temperatures. During IPHP, DT rose up to nearly 40 degrees C, and we considered it very useful to judge the temperatures of the other intra-abdominal organs, which were in contact with the perfusate of IPHP. Judging from the difference of PAT and ST, ST was found useful to estimate the degree of insufficiency of the peripheral circulation. We calculated the correlation coefficients with PAT among the four points, and the order of the correlation coefficients was EAT > ET > FT > RT. EAT showed the highest correlation coefficient with PAT (r = 0.981), and we considered EAT can be a substitute for PAT during IPHP. ET also showed a high correlation with PAT (r = 0.959), but it showed an unusual rise in a case of hydrothorax with hot perfusate for IPHP. Therefore, ET cannot be used solely as a substitute for PAT, but ET can be used as a marker to find a complication of IPHP, hydrothorax.
Adult↗
Isolation and characterization of the gene for mouse hormone-sensitive lipase.
Hormone-sensitive lipase (HSL) is the rate-limiting enzyme in hydrolysis of triglycerides in adipose tissue and of cholesteryl esters in steroidogenic tissues and macrophages. The gene encoding mouse HSL has been isolated and characterized from two overlapping lambda clones. The gene spans approximately 10.4 kb and comprises 9 exons interrupted by 8 introns. The deduced amino acid sequence specifies a protein of 759 amino acids with a Mr of 83,297 in the absence of posttranslational modifications. The known functional domains of the HSL protein are encoded by discrete exons, with the putative catalytic site (Ser423) encoded by exon 6, and the basal and regulatory phosphorylation sites (Ser557 and Ser559) encoded by exon 8. In addition, a putative lipid binding domain occurs in exon 9. The mouse protein shows 94% identity with the previously determined rat sequence and 85% identity with the recently determined human sequence. Interestingly, despite the high degree of similarity, the three species diverge significantly for a stretch of 16 amino acid residues upstream of the phosphorylation sites. In addition, an error was discovered in the carboxyl-terminal portion of the previously reported rat sequence, which produced a frame shift and premature termination of the coding sequence. The corrected rat sequence alters the identity of 12 amino acid residues and extends the protein an additional 11 residues. We have also examined the mouse HSL gene and 5' flanking region for nucleotide sequences that may modulate HSL gene transcription. Using primer extension, we identified a major transcription initiation site 593 nucleotides upstream of the protein coding sequence.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Abnormalities of meioses in male reciprocal hybrids between the Hiroshima and Ichinoseki populations of Rana japonica.
In order to elucidate cytogenetically the cause of male sterility in intraspecific hybrids of Rana japonica, the behavior of chromosomes in the first meiosis was observed in spermatocytes from male reciprocal hybrids between two populations from Hiroshima and Ichinoseki. In the parental Hiroshima and Ichioseki populations, 2530 (96.7%) meiotic spreads had 13 bivalents and 78 (3.0%) contained 12 bivalents and two univalents, whereas in reciprocal hybrids only 337 (7.0%) contained 13 bivalents and the other 4445 (93.0%) had 2-26 univalents. A total of 31647 (93.4%) bivalents was ring-shaped and the other 2234 (6.6%) were rod-shaped in both parental populations, whereas in reciprocal hybrids 26352 (57.1%) and 19819 (42.9%) bivalents were ring- and rod-shaped, respectively. These results show that meiotic chromosomes of reciprocal hybrids are characterized by a remarkable increase in univalents and rod-shaped bivalents.
Animals↗
Role of two nucleotide-binding regions in an N-ethylmaleimide-sensitive factor involved in vesicle-mediated protein transport.
N-Ethylmaleimide-sensitive factor (NSF) was originally characterized as the protein that restores in vitro protein transport activity of the Golgi membranes inactivated by N-ethylmaleimide. This protein has two homologous regions, each containing the consensus sequence for nucleotide binding, and possesses ATPase activity. To investigate the role of the two nucleotide-binding regions in NSF, we have replaced two lysyl residues (Lys-274 and Lys-557) located in the consensus sequences with glutamine or methionine via site-directed mutagenesis. The mutant NSF proteins in which Lys-274 was replaced had no ability to restore protein transport between N-ethylmaleimide-treated Golgi membranes and, in addition, inhibited the protein transport assay using normal Golgi membranes. This inhibition, which was eliminated by N-ethylmaleimide treatment, was caused by the impairment of the function of donor Golgi membranes. Although wild-type NSF showed a protective effect against inhibition by the Lys-274 mutant NSF protein when added at the start of the protein transport assay, its protective effect diminished after the time for the formation of transport vesicles had passed. These results support the idea that NSF incorporated into transport vesicles is nonexchangeable for exogenously added NSF. On the other hand, the mutant proteins in which Lys-557 was replaced had slight but significant protein transport activity. They did not inhibit the protein transport assay using normal Golgi membranes. The mutant NSF proteins in which Lys-274 and Lys-557 were replaced had about 20 and 25% of the ATPase activities of wild-type NSF, respectively. Their ATPase activities were sensitive to N-ethylmaleimide and dependent on their protein concentrations, as observed in wild-type NSF.
Adenosine Triphosphatases↗
MRI of pituitary adenomas: the position of the normal pituitary gland.
The position of the normal pituitary gland, assessed using gadolinium - enhanced MRI was compared with the position found at surgery for pituitary adenoma in 25 patients. The tumours were five microadenomas and 20 macroadenomas. Using T1-weighted imaging, the anterior lobe could be differentiated on the sagittal image in five patients (20%) and on the coronal image in four (16%). The high intensity of the posterior lobe could be differentiated using T1-weighted sagittal imaging in 13 patients (52%). The normal pituitary gland, which enhanced more strongly than tumour, could be differentiated using Gd-DTPA-enhanced MRI on the sagittal images in 22 cases (88%) and on the coronal image in 17 (68%). In seven patients, the normal pituitary gland surrounded the tumour; it was displaced superiorly in 14 cases and superioposterorly in two but in no case was it displaced anteriorly or downwards.
Adenoma↗
Embolisation of orbital varix.
A 34-year-old man with intermittent exophthalmos, found to have a large varix in the right orbit, was treated by endovascular surgery. Percutaneous transfemoral venous catheterisation and embolisation of the orbital varix was performed on two occasions. A Tracker 18 microcatheter was introduced through the right inferior petrosal sinus, cavernous sinus, superior ophthalmic vein and then into the varix, following a guidewire. Superselective venography of the right ophthalmic vein showed the varix. A total of 204 platinum microcoils was used to pack the varix. At the time of discharge, the exophthalmos had largely resolved. As this technique is much less invasive than surgical resection, we recommend an attempt at endovascular embolisation of orbital varices prior to surgical removal.
Adult↗
Displacement of the normal pituitary gland by sellar and juxtasellar tumours: surgical-MRI correlation and use in differential diagnosis.
We compared the position of the normal pituitary gland as estimated by gadolinium (Gd)-DTPA-enhanced MRI, with its position at surgery in 40 patients with intra- and juxtasellar tumours: 22 pituitary adenomas, 4 craniopharyngiomas, 7 meningiomas, 2 germinomas, and 5 Rathke cleft cysts. In 37 of these, the normal gland showed more intense contrast enhancement than the adjacent tumour, from which it could be differentiated by Gd-DTPA-enhanced MRI, especially in the sagittal plane. The direction of displacement of the normal pituitary gland correlated well with tumour type, so that its position proved helpful in the differential diagnosis. The normal gland was typically displaced superiorly by pituitary adenomas, inferiorly by craniopharyngiomas, and anteriorly by germinomas. It showed variable displacement by Rathke cleft cysts, and was not usually displaced by meningiomas.
Adenoma↗
A pronounced sex difference when two linked loci of the Japanese brown frog Rana japonica are recombined.
To investigate the sex differences of crossing-over in Rana japonica, the recombination frequencies between two linked loci, LDH-B and MPI, were examined in offspring obtained from 29 matings involving either females or males heterozygous at both loci. No recombinants were found among 303 offspring bred from 6 heterozygous males, whereas 160 were parental and 138 were recombinants among 298 offspring bred from 9 heterozygous females. The recombination frequency was 46.3%. These results show that the sex difference when two loci were recombined was marked and significant in Rana japonica.
Alleles↗
Clinical evaluation of 33 patients with histologically verified germinoma.
We evaluated 33 patients with histologically verified germinoma between 1978 and 1992. The patients consisted of 23 men and 10 women between 6 and 32 years of age. All patients underwent either biopsy, partial resection, or total resection. All patients received radiotherapy, and all had a complete remission. Recurrence occurred in three patients. Two recurrences were outside of the irradiated area. Though there were four deaths, none were caused by germinoma. Three resulted from the inadequate hormonal replacement. Accurate staging of patients with germinoma using magnetic resonance imaging (MRI), including whole spinal MRI, and development of a radiochemotherapy or chemotherapy method that preserves the hypothalamic-pituitary axis function are needed.
Adolescent↗
Comparison of three-dimensional phase-contrast magnetic resonance angiography with three-dimensional time-of-flight magnetic resonance angiography in cerebral aneurysms.
Magnetic resonance angiography (MRA) can be divided into two types: namely, the phase-contrast (PC) method and the time-of-flight (TOF) method. The purpose of this study is to determine which method is better suited to demonstrate cerebral aneurysms. In a total of 27 cerebral aneurysms confirmed by cerebral angiography, both three-dimensional (3-D) PC and 3-D TOF methods were performed, and the corresponding findings were compared with conventional cerebral angiographic findings. Aneurysm visualization was grouped into three categories: "good" when clearly distinguishable, "fair" if distinguishable when reconstructed, and "poor" if completely undistinguishable. All MRAs were independently interpreted by two neurosurgeons in our institute. Sensitivity was 92.6% when MRA was performed with the TOF method, whereas it was 70.4% when performed with the PC method. In conclusion, the TOF method was more useful for demonstrating the aneurysms than the PC method due to its higher spatial resolution and shorter imaging time.
Adult↗