Biomedical subjects

A Kato

Publications and source records attributed to A Kato.

At least 253 records · Page 14Linked to original sources

PubMed1998

Numerical aberrations of chromosomes 16, 17, and 18 in hepatocellular carcinoma: a FISH and FCM analysis of 20 cases.

Conventional cytogenetic studies have demonstrated frequent abnormalities of specific chromosomes in hepatocellular carcinoma, although there are few reports examining the relationship between chromosomal aberrations and clinicopathologic features. In this study, numerical aberrations of chromosomes 16, 17, and 18 were examined by fluorescence in situ hybridization using pericentromeric DNA probes in 20 cases of surgically removed hepatocellular carcinoma. DNA ploidy analysis was also performed by flow cytometry. Numerical abnormalities of chromosomes 16, 17, and 18 were found in 7 of 19 cases, 15 of 20 cases, and 12 of 20 cases, respectively. Gain and/or loss of more than one chromosome was detected in 16 of 19 cases. However, aneuploidy was seen in only 9 of 20 tumors by flow cytometry. The incidence of aneusomy 17 and 18 increased with tumor size and stage progression. Fluorescence in situ hybridization analysis demonstrated that numerical chromosomal aberrations accumulated with tumor progression in hepatocellular carcinoma.

Adult↗

PubMed1998

The clinical role of specific IgE and IgG4 antibodies in patients having immunotherapy for seasonal allergic rhinitis.

This study was designed to investigate the clinical role of specific IgG4 and IgE responses in patients during immunotherapy for seasonal allergy. The study included 109 patients with seasonal allergic rhinitis due to Japanese cedar pollens. They were divided into the control group and the immunotherapy group. Serum samples were obtained at the start of immunotherapy, before the pollen season and during the season, to determine serum specific IgE and IgG4. In the control group specific IgE was significantly increased, but specific IgG4 was not changed during the pollen season. In the immunotherapy group specific IgE was not significantly increased, but specific IgG4 was significantly increased during the season. In the patients having immunotherapy for 2 years or less, the seasonal increase in specific IgG4 related to the magnitude of the clinical effect. In the patients having immunotherapy for 3 years or more, the seasonal increase in specific IgE related to the magnitude of the clinical effect. In conclusion, the specific IgG4 response and specific IgE response during the pollen season make a significant contribution to the clinical effect of immunotherapy. However, modulation of specific IgE and IgG4 responses out of the pollen season was unlikely to be an important phenomenon related to the clinical effect of immunotherapy.

Adolescent↗

PubMed1998

Sendai virus C proteins are categorically nonessential gene products but silencing their expression severely impairs viral replication and pathogenesis.

BACKGROUND: The P/C mRNA of Sendai virus (SeV), a prototypic member of the family Paramyxoviridae in the Mononegavirales superfamily comprising a large number of nonsegmented negative strand RNA viruses, encodes a nested set of accessory proteins, C', C, Y1 and Y2, referred to collectively as C proteins, initiating, respectively, at ACG/81 and AUGs/114, 183, 201 in the +1 frame relative to the ORF of phospho (P) protein, the smaller subunit of RNA polymerase. Among them, C is the major species expressed in infected cells at a molar ratio which is several-fold higher than the other three. However, their function has remained an enigma. It has not even been established whether or not the C proteins are essential for viral replication. Many other viruses in Mononegavirales encode C-like proteins, but their roles also remain to be defined. RESULTS: By taking advantage of a recently developed reverse genetics system to recover infectious SeV from cDNA, we created mutants in which C protein frames were variously silenced. C/C'(-) viruses which did not express C and C', but did express Y1 and Y2, were severely attenuated in replication in tissue culture cells of various species and tissues, as well as in embryonated chicken eggs. More notably, they were almost totally incapable of growing productively in--and hence nonpathogenic for mice--the natural host. Both gene expression and genome replication appeared to be impaired in C/C'(-) viruses. Additionally silencing the Y1 and Y2 expression was also possible, and a critically impaired but viable clone, the 4C(-) virus, was isolated which expressed none of the four C proteins. CONCLUSION: SeV C proteins are categorically nonessential gene products, but greatly contribute to full replication capability in vitro and are indispensable for in vivo multiplication and pathogenesis. This study represents the first comprehensive functional assessment of the accessary C protein for Mononegavirales.

Animals↗

PubMed1998

Ten-year follow-up study of allergen-specific immunoglobulin E and immunoglobulin G4, soluble interleukin-2 receptor, interleukin-4, soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1 in serum of patients on immunotherapy for perennial allergic rhinitis.

Recent double-blind placebo-controlled trials for perennial allergic rhinitis have all clearly shown the efficacy of immunotherapy. Although several mechanisms for the clinical efficacy of immunotherapy have been proposed, the exact mechanisms related to the clinical effect still remain unclear. Since immunotherapy is a form of systemic treatment and its clinical benefit is likely to be, at least in part, a consequence of its systemic effects on different phases of immunological events, our study focused exclusively on several immunological parameters in serum. A total of 47 patients with perennial allergic rhinitis due to Dermatophagoides farinae enrolled in this prospective study. Venous blood was collected for determination of specific immunoglobulin (Ig)E, specific IgG4, soluble interleukin-2 receptor (IL-2R), interleukin-4 (IL-4), soluble intercellular adhesion molecule-1 (ICAM-1) and soluble vascular cell adhesion molecule-1 (VCAM-1), six times from 20 untreated patients and 27 patients on immunotherapy, at enrolment, and 1, 2, 3, 5, and 10 years after enrollment. No specific IgE, IgG4, soluble IL-2R, IL-4 and soluble ICAM-1 levels changed significantly for a span of 10 years in the untreated patients. By contrast, immunotherapy affected serum levels of specific IgE, specific IgG4, soluble IL-2R, IL-4 and soluble ICAM-1, but not of soluble VCAM-1. The rates of increase in specific IgG4 and the rates of decrease in soluble IL-2R were correlated with the rates of decrease in symptom scores during the first 3 years, but not 5 and 10 years after the course of immunotherapy. On the other hand, the rates of decrease in specific IgE, IL-4 and soluble ICAM-1 were significantly correlated with the rates of decrease in symptom scores at 5 and 10 years, but not during the first 3 years. Each immunological modulation by immunotherapy was likely to be involved in the working mechanism related to clinical efficacy at different phases of immunotherapy.

Adolescent↗

PubMed1998

Allergen-induced synthesis of interleukin-5, but not of IgE, is a key mechanism linked to symptomatic episodes of seasonal allergic rhinitis in sensitized individuals.

Some individuals with detectable levels of Japanese cedar (Criptomeria japonica) pollen-specific immunoglobulin (Ig)E in serum have no apparent nasal symptoms during the pollen season. The response of CD4+ T-helper (Th) cells to the pollen allergen might differ fundamentally between asymptomatic and symptomatic individuals who are already sensitized to the pollen. The aim of this study was to discern the possible differences in responses of peripheral blood mononuclear cells (PBMCs) to the pollen allergen between asymptomatic and symptomatic subjects who have been sensitized to the pollen. This study included 20 non-atopic healthy volunteers (non-atopic group) and 48 patients who had detectable levels of the pollen-specific IgE before the pollen season in 1997. In the review of nasal symptoms during the pollen season 1997, 24 patients had typical symptoms of seasonal allergic rhinitis (symptomatic group), and the remainder had no seasonal aggravation of nasal symptoms (asymptomatic group). Peripheral blood mononuclear cells (1.0 x 10(7) cells/well) were obtained from each individual during the pollen season and cultured in the absence or presence of 12.5 microg of Cry j 1 for 4 days. The concentrations of IgE, interleukin-5 (IL-5), and interferon-gamma (IFN-gamma) in the culture supernatants were measured. The levels of IgE produced by Cry j 1-stimulated PBMCs of the asymptomatic and symptomatic groups were significantly higher than those of the non-atopic group, but did not differ between the asymptomatic and symptomatic groups. The levels of IL-5 produced by Cry j 1-stimulated PBMCs did not differ significantly between the non-atopic group and the asymptomatic group, but the levels of IL-5 were significantly higher in the symptomatic group than in the asymptomatic group as well as the non-atopic group. The levels of IFN-gamma produced by Cry j 1-stimulated PBMCs did not differ significantly among the three groups. In conclusion, our study has suggested that Japanese cedar pollen-induced synthesis of IL-5, but not of IgE or IFN-gamma, is likely to be a key mechanism linked to the symptomatic episode of seasonal allergic rhinitis in individuals sensitized to the pollen.

Adolescent↗

PubMed1998

The Arabidopsis ERECTA gene is expressed in the shoot apical meristem and organ primordia.

In Arabidopsis thaliana (L.) Heynh, the mutation in ERECTA is known to confer a compact inflorescence by a reduction in the lengths of internodes and pedicels. We analyzed the expression pattern of this gene during plant development. In situ hybridization and histochemical analysis using transgenic plants carrying chimeric gene fusions, with the ERECTA promoter fused to the beta-glucuronidase (GUS) gene, showed that ERECTA was predominantly expressed in the shoot apical meristems and organ primordia. ERECTA expression in the shoot apical meristem was weak early in plant development but increased with the transition from the vegetative to the reproductive growth phase. ERECTA was also strongly expressed in organ primordia and immature organs but weakly in mature organs. Thus, ERECTA was expressed in a cell-specific and developmentally regulated manner. In order to identify the regulatory mechanism responsible for the expression pattern of ERECTA, the cis-acting regions in the ERECTA promoter were defined by study of the expression of the chimeric genes that consist of the 5'- or internal deleted promoter and a GUS reporter gene in transgenic plants. The results showed that the essential cis-regulatory elements governing the spatially and temporally specific expression of ERECTA are located between positions -462 and -228 bp and between positions -228 and -153 bp with respect to the transcriptional initiation site.

Arabidopsis↗

PubMed1998

Seasonal rise in interleukin-4 during pollen season is related to seasonal rise in specific IgE for pollens but not for mites.

Since IL-4 plays a key role in inducing and increasing the generation of not only primary polyclonal but also secondary specific IgE responses by B lymphocytes, a seasonal increase in IL-4 is likely to be involved in such seasonal rises in specific IgE in seasonal allergic rhinitis. The first aim of this study was to investigate the possible seasonal increase in serum IL-4 in patients with seasonal allergic rhinitis due to Japanese cedar pollens. If serum IL-4 increases in response to seasonal pollen exposure and is responsible for the seasonal increase in pollen-specific IgE in sera, this increase in IL-4 might theoretically affect specific IgE synthesis for other allergens. The second aim was to investigate the effect of natural pollen exposure on serum concentrations of house dust mite-specific IgE in patients who have seasonal allergic rhinitis and concurrent perennial allergic rhinitis due to house dust mites. This study included 55 adult patients with seasonal and perennial allergic rhinitis due to Japanese cedar pollens and Dermatophagoides farinae (D. farinae). Venous blood was collected twice from each patient, before and during the cedar pollen season 1996, to determine IL-4, cedar pollen-specific IgE and D. farinae-specific IgE in sera. Both IL-4 and pollen-specific IgE in sera were significantly increased during the pollen season, and the seasonal increase rate in pollen-specific IgE was significantly correlated with the seasonal increase rate in IL-4. By contrast, D. farinae-specific IgE was not changed during the pollen season in these patients. In conclusion, an elevation of IL-4 in sera during the pollen season may play an important part in the seasonal rise in pollen-specific IgE, and enhancement of specific IgE synthesis is likely to need not only an increase in IL-4 but also an increase in the number and/or capacity of specific IgE-secreting B cells.

Adolescent↗

PubMed1998

Soluble vascular cell adhesion molecule-1 in perennial allergic rhinitis.

Since the expression of vascular cell adhesion molecule-1 (VCAM-1) on endothelial cells plays a central part in the selective recruitment of eosinophils into allergic inflammatory lesions, VCAM-1 may be a key molecule in allergic inflammatory diseases. Soluble forms of VCAM-1 (sVCAM-1) have recently been identified in the circulation, but there is limited published information on levels of sVCAM-1 in the circulation. If the levels of sVCAM-1 vary between patients with allergic diseases and normal controls, this variance would be very useful to investigate the state of the allergic disease and underlying inflammation. This study investigated the serum sVCAM-1 level in patients with perennial allergic rhinitis (rhinitis group) in comparison with non-atopic healthy volunteers (control group). No significant difference in the serum sVCAM-1 level was seen between the two groups (p = 0.4342). However, the serum sVCAM-1 levels in the severe rhinitis group were significantly higher than those in both the control group (p = 0.0067) and the mild rhinitis group (p = 0.0015), whereas no significant difference was observed between the mild rhinitis group and the control group (p = 0.1113). In addition, the serum levels of sVCAM-1 were significantly correlated with the nasal symptoms in the rhinitis group (rs = 0.486, p < 0.0001). In conclusion, serum concentrations of sVCAM-1 are increased in patients with severe perennial allergic rhinitis, and measurement of sVCAM-1 concentrations in sera is likely to be a useful tool for investigation of the severity of allergic rhinitis and underlying inflammatory reactions.

Animals↗

PubMed1998

Interleukin-6 and tumour necrosis factor alpha synthesized by cholesteatoma cells affect mucociliary function in the eustachian tube.

The aims of this study were to investigate the possible synthesis of IL-6 and TNF-alpha by cholesteatoma cells in culture and the effect of IL-6 and TNF-alpha produced by cultured cholesteatoma cells on the function of the mucociliary system in the tubotympanum. Cholesteatoma cells were collected from 10 patients, and the medium supernatants in which cholesteatoma cells or normal human epidermoid cells had been cultured for 48 h were collected. The concentrations of IL-6 and TNF-alpha in the supernatants were measured by enzyme-linked immunosorbent assays. The effect of the culture supernatants on ciliary activity was examined using an in vitro experimental system. The supernatants were injected into the tympanic cavities of guinea pigs, and mucociliary clearance time of the Eustachian tube was determined according to our dye transport technique 24 h after the intratympanic injection. Human cholesteatoma cells produced larger amounts of IL-6 and TNF-alpha than normal human epidermoid cells. The supernatants of cholesteatoma cells compromised ciliary activity and mucociliary clearance of the Eustachian tube in the guinea pigs. The effects of the supernatants of cholesteatoma cells on the ciliary activity and mucociliary clearance were correlated with the concentration of IL-6 and TNF-alpha in the supernatants. In conclusion, cholesteatoma cells can produce IL-6 and TNF-alpha, which are able to compromise the mucociliary function in the tubotympanum. IL-6 and TNF-alpha produced in middle ear cholesteatoma might aggravate the disease by the wide range of their biological activities on the mucociliary system, the proliferation of cholesteatoma cells and the bone metabolism.

Adult↗

PubMed1998

Temperature distribution produced by laser irradiation in a ventricle model. The use of airflow in neuroendoscopic surgery.

The changes in intraventricular temperature during potassium titanyl phosphate laser irradiation were investigated using a ventricle configuration model. The laser had an output of 3 to 20 watts in 1 second pulse mode. The model ventricular cavity was filled with still air or saline, or irrigated with air or saline. The laser irradiation in a continuous mode with the output of 15 or 20 watts was also examined under air flow or saline irrigation. In pulse-mode irradiation, the temperature increase was less than 5.0 degrees C under all conditions with the outputs up to 10 watts. With 20 watts pulse irradiation, the temperature increase was within 7 degrees C with air flow, and over 20 degrees C in still air. The later condition occasionally induced a plume of steam resulting in excessive temperature elevation at a remote point. With the continuous irradiation of 15 or 20 watt, the temperature increased by about 4.0 degrees C even under saline irrigation, which required over 30 sec to return to the pre-irradiation level. These results indicate the possible use of pulse mode laser irradiation and air flow endoscopic surgery within the ventricular system. With continuous mode laser irradiation, however, the importance of saline irrigation and proper cooling interval is suggested.

Air Movements↗

PubMed1998

Computational imaging of cerebral perfusion by real time processing of DSA images. Clinical applications.

Real time and high resolution functional imaging of cerebral perfusion was developed, which displays the color coded image of the cerebral perfusion index (PI) from the serial images of digital subtraction angiography (DSA). The small (3 x 3 pixels) regions of interest (ROI) were set on the images, and the time density curves of the contrast media for each ROI were obtained. The perfusion indices, corresponding to the mean transit time (MTT), were calculated for all the ROIs on the image in real time (5 sec) by the area over height method and then, converted to the PI image. A large ROI (64 x 64 pixels) was also used to estimate the parenchymal perfusion. In the normal subjects, consistent PI values at the various parts of the cerebral arteries were obtained, which reasonably agreed with the published values when converted to the blood flow. Then the study on the pathological subjects were made. Firstly, the alteration in the PI images agreed well with the CBF SPECT study in the case of moyamoya disease with the synangiosis operation. Secondly, even a 5% change of the parenchymal perfusion could be detected with the PI imaging, which was obscure when inspecting the series of DSA images, in the case of intra-arterial papaverine infusion for delayed vasospasm. Thirdly, the vortex inside a large aneurysm could be estimated with the same resolution as DSA. Our method offers real time, high resolution, projection angle independent and semiquantitative imaging of the cerebral perfusion from the conventional DSA images without introducing any new expensive devices. This method could be used to evaluate the therapeutic change and especially to monitor the rapidly changing cerebral perfusion in interventional angiography.

Aged↗

PubMed1998

Dysembryoplastic neuroepithelial tumor in the insular cortex. Three dimensional magnetoencephalographic localization of epileptic discharges.

A case of dysembryoplastic neuroepithelial tumor in the left insular cortex manifesting with intractable seizures is presented. The multichannel magnetoencephalography (MEG) localized equivalent current dipoles of epileptic discharges at the cerebral cortex adjacent to the tumor. The total removal of the tumor resulted in complete disappearance of seizures. This case demonstrated that multichannel MEG was useful in the three-dimensional localization of irritative zone in the concealed cortices such as inside the sylvian fissure.

Brain Neoplasms↗

PubMed1998

Spatial perception in macroscopic and microscopic surgical manipulations: differences between experienced and inexperienced surgeons.

The spatial perceptions of the phantom surgical field with the naked eye and under the surgical microscope were analyzed in a group of experienced and a group of inexperienced neurosurgeons. The phantom surgical field contained a start point, a virtual gate, and a target point. The virtual gate was an invisible zone arbitrarily set in the phantom surgical field. The examinees were first instructed regarding the position of the invisible virtual gate. Then they were asked to point consecutively to the three points with a suction tube under three different circumstances: with the naked eye, under the microscope, and by watching a navigation monitor. A surgical navigator was used to record the three-dimensional position of the suction tip. The pointing deviation from the suction tip to the center of the virtual gate was evaluated. The pointing accuracy with the naked eye did not differ between the two groups, but that under the microscope was significantly better in the experienced group than in the inexperienced group. Fluctuations in pointing deviation were significantly greater in the inexperienced neurosurgeons, especially with the microscope. Further analysis demonstrated that these differences were attributable to poorer depth perception of the phantom surgical space among the inexperienced neurosurgeons.

Clinical Competence↗

PubMed1998

A peritoneal marker for optimal timing of ventriculo-peritoneal shunt revision in early childhood.

The ventriculo-peritoneal shunt placed in a neonate or infant needs revision to lengthen the peritoneal tube at certain times during childhood. The critical time for this revision is not exactly the same between individuals. Furthermore, the level of peritoneal insertion of the shunt tube is often unclear on x-ray films. To plan for and determine the optimal timing of revision, we applied a titanium clip on the peritoneal suture line in three infants as a marker of peritoneal insertion level. During the 31- to 37-month follow-up period, abdominal x-ray clearly demonstrated the peritoneal insertion level in all three patients, allowing accurate determination of the length of the intraperitoneal portion (i.p.) of the shunt tube. The rate of shortening of the length of i.p was 20 to 27% of the increase in body height (BH). This technique allows accurate determination of the length of i.p. and also optimal timing for revision.

Body Height↗

PubMed1998

Translucence stereoscopy of interictal magnetoencephalographic epileptiform discharge.

We have developed a translucence stereoscopy method for displaying the distribution of multiple interictal epileptiform discharges within the intracranial space. The epileptiform discharges, measured using a whole-head magnetoencephalography system, were modeled by a least-squares method to obtain the equivalent current dipoles. The dipoles were located in the stereo pair of intracranial images composed of translucent brain slices at several selected levels. The technique demonstrated clearly the distribution of interictal dipoles within the brain in three patients. Three dimensional understanding of the intracranial distribution of multiple dipoles in one image is valuable in analyzing the intracerebral neurophysiological events in epileptic patients.

Adult↗

PubMed1998

Mobile fluoroscopic open stereotaxy for MRI-negative angiographic microlesions.

The approach to the deep-seated angiographic microlesion is often difficult, particularly when it is not demonstrated by computed tomography (CT) or magnetic resonance imaging (MRI). We have developed a method to localize these lesions for open stereotactic surgery employing mobile fluoroscopy. Prior to craniotomy, the patient's head is fixed in a stereotactic frame in a position optimal for the routine microscopic surgery. Following the injection of contrast media, the location of the lesion is marked on the fluoroscope monitor. Under fluoroscopic control, the scalp is marked using radiopaque pointer on each side of the patient's head so that the scalp marks and the target lesion overlap each other on the fluoroscope monitor. Thus the imaginary line connecting these scalp marks passes through the lesion. An additional pair of scalp marks is obtained by changing the projection angle of the fluoroscope. By simple calculation, the coordinates of the lesion are obtained as the nearest point to these two imaginary lines, each of which connects a pair of scalp marks. After craniotomy, the lesion is approached using an open stereotactic technique. The first patient had an aneurysm 1.5 mm in diameter that arose from the feeder of the arteriovenous malformation. The second patient had a small residual nidus of arteriovenous malformation 1.5 cm in diameter in the deep frontal lobe, not recognizable by CT or MRI because of artifacts from a previous surgery. Both patients were successfully operated by employing the present method. This method requires only a conventional stereotactic frame and a mobile fluoroscope, and provides simple and reliable localization of the small lesions recognizable only by cerebral angiography.

Arteriovenous Malformations↗

PubMed1998

Evolution of the trappin multigene family in the Suidae.

Trappins are a group of secretory proteins containing a WAP motif with an anchoring domain. Previous studies showed that their genes, especially those of pig, have undergone rapid evolution, which produced trappins with a broad spectrum of actions. To understand the evolution of such a rapidly evolving multigene family, we isolated trappin genes of the Artiodactyla, including pig, wart hog, collared peccary, hippopotamus, and cow, by means of polymerase chain reaction (PCR). Two genes newly isolated from wart hog are orthologs of trappin-1 (SPAI) and trappin-2 (elafin), the others are novel members of the trappin family and named trappins-6 to 11. The divergence of the sequences is greatest in the region that encodes the reactive site, and intron sequences appear to be more highly conserved than the protein-coding sequences, especially among the pig paralogs. Phylogenetic analysis showed that the trappin multigene family members of pig were generated through gene duplication after the divergence of the Suidae (pig and wart hog) and Tayassuidae (collared peccary). Similarities in the gene structure with seminal vesicle clotting proteins (REST) and WAP motif-containing proteins suggest that trappins are naturally occurring fusion proteins created through exon shuffling between ancestral REST and WAP motif-coding genes.

Amino Acid Sequence↗

PubMed1998

Glyoxysomal malate dehydrogenase in pumpkin: cloning of a cDNA and functional analysis of its presequence.

Glyoxysomal malate dehydrogenase (gMDH) is an enzyme of the glyoxylate cycle that participates in degradation of storage oil. We have cloned a cDNA for gMDH from etiolated pumpkin cotyledons that encodes a polypeptide consisting of 356 amino acid residues. The nucleotide and N-terminal amino acid sequences revealed that gMDH is synthesized as a precursor with an N-terminal extrapeptide. The N-terminal presequence of 36 amino acid residues contains two regions homologous to those of other microbody proteins, which are also synthesized as large precursors. To investigate the functions of the N-terminal presequence of gMDH, we generated transgenic Arabidopsis that expressed a chimeric protein consisting of beta-glucuronidase and the N-terminal region of gMDH. Immunological and immunocytochemical studies revealed that the chimeric protein was imported into microbodies such as glyoxysomes and leaf peroxisomes and was then subsequently processed. Site-directed mutagenesis studies showed that the conserved amino acids in the N-terminal presequence, Arg-10 and His-17, function as recognition sites for the targeting to plant microbodies, and Cys-36 in the presequence is responsible for its processing. These results correspond to those from the analyses of glyoxysomal citrate synthase (gCS), which was also synthesized as a large precursor, suggesting that common mechanisms that can recognize the targeting or the processing of gMDH and gCS function in higher plant cells.

Amino Acid Sequence↗