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Biomedical subjects

K Sekiyama

Publications and source records attributed to K Sekiyama.

At least 37 records · Page 2Linked to original sources
PubMed1994

Prognostic value of hepatic volumetry in fulminant hepatic failure.

Serial hepatic volumetry calculated from the liver area on abdominal computed tomography was performed in 19 patients with fulminant hepatic failure to determine a relationship between liver volume and prognosis. All patients received intensified artificial liver support comprised of plasma exchange and hemodiafiltration using high-performance membranes, and 10 patients survived. Liver volume was significantly larger in survivors than in nonsurvivors, both in an initial volumetry performed at the onset of coma and in subsequent volumetry performed 10-20 days after the onset of coma. The difference became more significant in the subsequent volumetry because of the recovery of liver size in some of the survivors and progressive liver shrinkage in all nonsurvivors. All patients with a liver volume greater than 656 ml at 10-20 days after the onset of coma survived, whereas all but one patient with a liver volume less than that died. Multivariate analysis revealed only liver volume in subsequent volumetry had discriminatory power upon prognosis among six prognostic factors. These observations imply that in order to obtain an accurate prediction of fulminant hepatic failure by hepatic volumetry, serial studies at least until 10-20 days after the onset of coma are necessary.

Adult↗
PubMed1994

[Interferon treatment of type C fulminant hepatitis].

On the contrary to Western countries, there are a substantial number of patients with type C fulminant hepatitis (FH) including coinfection on type A and type B hepatitis in Asian countries. The pathogenesis of FH is not fully understood, however, recent clinical observations suggest that enhanced host immune responses contribute to hepatocyte destruction in type C FH. In contrast to type B FH, type C FH is characterized by gradual and continuous liver necrosis probably duo to persistent infection of hepatitis C virus. Administration of interferon with immunosuppressive agents is the treatment of choice. Prognosis may be improved if the treatment is started in the early stage of the disease.

Adult↗
PubMed1993

Development of reliable artificial liver support (ALS)--plasma exchange in combination with hemodiafiltration using high-performance membranes.

A new artificial liver support system (ALSS) consisting of plasma exchange (PE) in combination with hemodiafiltration (HDF) using high-performance membranes of polymethyl methacrylate (PMMA) and cellulose triacetate (CTA) was developed to efficiently remove middle molecules from plasma and treat fulminant hepatic failure (FHF) complicated by the onset of hepatic coma. Twenty-seven patients with FHF due to viral hepatitis, two with type A (HA), nine with type B (HB), and 16 with type non-A, non-B (NANB) underwent therapy with this new ALSS over the last five years. Three patients with an exacerbation of chronic HB and 15/16 with type NANB hepatitis were treated with interferon (IFN) also. Of these, 25 patients (92.6%) regained consciousness and 15 (55.6%) [1/2 (50%) with type A, 6/9 (66.7%) with type B and 8/16 (50%) with type NANB hepatitis] survived. Including four patients who survived with intensive care and plasma exchange alone, 19/31 (61.3%) patients survived. Because of its biocompatibility, both survivors and nonsurvivors could be sustained with the ALSS without complications for long periods (19.3 days for the survivors and 32.4 days for nonsurvivors). With this ALSS the ability to sustain life for such prolonged periods allows hepatic regeneration to occur and result in patient survival. It is anticipated that this new ALSS will not only be of value in cases of fulminant hepatic failure but that it may also play a role in sustaining life for those awaiting liver transplantation.

Adult↗
PubMed1992

Reactivation of precore mutant hepatitis B virus leading to fulminant hepatic failure following cytotoxic treatment.

Three hepatitis B virus carriers who were HB(e)Ag negative and having normal liver function developed fulminant hepatitis with evidence of HBV replication following intensive chemotherapy for non-Hodgkin's lymphoma. Each was continuously negative for HB(e)Ag. Analysis of the precore region of HBV isolated from each demonstrated that the HBV of each had a point mutation in the precore region that inhibited the synthesis and the release of hepatitis B(e) antigen. This observation suggests that all HB carriers receiving either immunosuppressive or cytotoxic therapy should be monitored closely even if standard assays suggest that viral replication is not present. Sudden enhanced replication of a HBV mutant as a result of such therapy can be a cause of either very severe hepatitis or occasionally fulminant hepatitis.

Adult↗
PubMed1991

McGurk effect in non-English listeners: few visual effects for Japanese subjects hearing Japanese syllables of high auditory intelligibility.

The McGurk effect is a phenomenon that demonstrates a perceptual fusion between auditory and visual (lip-read) information in speech perception under the condition of audio-visual discrepancy, created by dubbed video tapes. This paper investigated whether or not the McGurk effect could be extended to Japanese subjects listening to Japanese syllables of different auditory intelligibility. The audio and video signal of a female talker's speech for ten Japanese syllables (/ba/, /pa/, /ma/, /wa/, /da/, /ta/, /na/, /ra/, /ga/, /ka/) was combined on videotapes, giving 100 audio-visual stimuli. These stimuli were presented to ten Japanese subjects who were required to identify the stimuli as heard speech in both noise-added and noise-free conditions. For both conditions, the intelligibility of the auditory stimuli was measured, by presenting the audio-alone stimuli. The results showed that, in the noise-free condition, the McGurk effect was small and almost limited to auditory stimuli of which the intelligibility was less than 100%. In the noise-added condition, the McGurk effect was very strong and widespread. These results indicate that the "Japanese McGurk effect" is less easily induced than the English one, and that it depends on the auditory intelligibility of the speech signal.

Adult↗
PubMed1991

Importance of head axes in perception of cutaneous patterns drawn on vertical body surfaces.

The "disembodied eye" phenomenon (Corcoran, 1977), that is, the observation that a cutaneous (tactile) pattern is perceived as right-left reversed or not, depending on whether it is presented on the forehead or the back of the head, was extended by incorporating a top-bottom axis into a model of the frame of reference in cutaneous-pattern perception. In two experiments, 21 and 15 subjects were asked to report the letter perceived when one of four letters (p, q, b, or d) was tactually presented. The sites studied were vertical body surfaces (Experiment 1) and hands alongside the body (Experiment 2). The positions for the presentations varied according to the height (head, shoulder, waist, thigh, and calf levels) and the orientation of the surface: forward-, backward-, and side-facing. Although the results for the head and back surfaces supported the notion of a "disembodied eye" behind the individual, other frames were needed: On the forward-facing surfaces below the waist, the prevailing perception was 180 degrees rotated, as if the subjects were looking at the surface by bending forward. An additional frame of reference was introduced for the forward-facing surfaces in lower positions and was described as head axes projected onto body surfaces within the possibility of actual body movements.

Attention↗
PubMed1987

[Mental rotation of kinesthetic hand images and modes of stimulus presentation].

Three experiments on mental rotation were carried out to investigate conditions under which hand images are operated kinesthetically. In Experiment 1 a, either a left or right hand was presented in a photographic slide, and subjects' task was left-right identification. In Exp. 2, each slide consisted of two hands, identical hands or mirror-imaged hands, and same-different judgment was required. In Exp. 3, two hands were presented successively, requiring same-different (mirror-reversed) judgement. On the other hand, subjects in Exp. 1 b were asked to rate physical difficulty of actual hand movements to imitate stimuli. Six to 12 undergraduate students served as subjects in each experiment. The results suggested that subjects' mental operations of hand images were kinesthetic in Exp. 1 a but visual in Exp. 2 and 3, on the basis of comparison between reaction times in the three experiments and the ratings in Exp. 1 b. Conditions which give rise to kinesthetic image processes were argued in relation with task structures.

Adult↗