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Biomedical subjects

N Hirai

Publications and source records attributed to N Hirai.

At least 73 records · Page 4Linked to original sources
PubMed1995

Kinetic modelling of liposome degradation in peritoneal macrophages.

The objective of this study was to quantify and model the degradation process of liposomes in peritoneal macrophages (PMs). Iodinated albumin (125I-alb) was chosen to be the marker of liposome degradation. The time course of the degradation of free 125I-alb after pinocytosis by PMs followed first-order kinetics with a half-life of 23 min. The degradation of liposomally encapsulated 125I-alb was also quantified. Kinetic modelling of liposome degradation indicated the existence of two kinetically different processes, one with a half-life of 13 min and the other with a half-life of 7.5 h. Comparing the degradation of liposomal and free 125I-alb suggested that 125I-alb was delivered to lysosomes much faster through phagocytosis than pinocytosis. These results indicate that the intracellular degradation kinetics of pinosomes and phagosomes is different. This method can quantify the rate and extent of liposomal degradation in macrophages and provide kinetic information on the intracellular destiny of liposomally encapsulated compounds.

Albumins↗
PubMed1995

Influence of minor trauma to the neck on the neurological outcome in patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.

The influence of minor trauma to the neck on the neurological outcome in patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine was evaluated retrospectively. Out of 118 patients treated in our clinic for cervical OPLL between 1976 and 1992, 27 had sustained minor trauma to the cervical spine. Of these 27 patients, 13 developed myelopathy, seven showed deterioration of preexisting myelopathy, and no neurological change was observed in seven patients. Regarding the relationship between the diameter of the residual spinal canal and the neurological outcome in these 27 patients, 18 out of the 19 patients with a narrow residual spinal canal (< 10 mm) developed neurological deterioration, whereas that occurred in only two of the eight patients with a wider spinal canal (> or = 10 mm). Although the severity of myelopathy and the transverse area of the spinal cord measured from T1-weighted magnetic resonance images, in patients who had sustained minor trauma was not statistically different from patients without trauma, neurological recovery after surgical treatment was poorer in the former group than in the latter. These results indicate that even indirect minor trauma to the neck can cause irreversible changes in the spinal cord if there is marked stenosis of the cervical spinal canal; such patients who are at risk, must be educated, and should be told to avoid even minor injuries at any cost.

Adult↗
PubMed1995

Effect of administration of serum thymic factor (FTS) in calves and rabbits infected with bovine immunodeficiency-like virus.

The effect of serum thymic factor (FTS) administration in bovine immunodeficiency-like virus (BIV)-infected calves and rabbits was examined. We previously found that some of the macrophage functions were depressed and humoral immune responses against foreign proteins were delayed in BIV-infected calves compared to uninfected calves. After FTS administration, however, no delay of antibody responses against foreign proteins was observed in BIV-infected calves. Though the chemiluminescence (CL) responses of macrophages in BIV-infected calves were significantly depressed (p < 0.05), FTS administration resulted in the recovery of the CL responses in the BIV-infected calves comparable to those in the control calves. Antibody responses against foreign proteins in BIV-infected rabbits were significantly depressed (p < 0.025) as compared with those in uninfected rabbits, though the depression became no significant after FTS administration.

Animals↗
PubMed1995

Computerized tomography in the assessment of brain shifts in acute subdural hematoma.

Computed tomography (CT) was used to characterize brain shifts in 30 adult patients (mean age 51.9 years) with fatal supratentorial acute subdural hematomes (ASH) who were admitted within 3 hours of the head trauma. The Glasgow Coma Scale (GCS) score, hematoma width, and midline shift were tabulated. The width of the cistern surrounding the brainstem (CSBS) and the distance from the floor of the fourth ventricle to the posterior clinoid process (IVv-PC) were measured. Opening (+) or disappearance (-) of the suprasellar cistern (SC) was determined using axial CT. The data were compared with those in agematched controls (n = 26) using the Wilcoxon and Kruskal-Wallis tests. The hematomas in the SC(-) group (n = 22, mean GCS score: 3.8 +/- 1.0) were wider (p = 0.02) than those in the SC(+) group (n = 8, mean GCS score: 4.7 +/- 1.5). The CSBS in the SC(+) group was significantly smaller than that in the controls (p < 0.01). In the SC(-) group the CSBS was smaller and the IVv-PC was significantly larger than those in the controls (IVv-PC; p < 0.01) and the SC(+) group (IVv-PC; p < 0.05). In the evolution of brainstem shifts in ASH, when the SC is open the predominant vector is in the direction of the skull base, while when the SC is not observed, an axial vector shifts the brainstem.

Adolescent↗
PubMed1995

Bone mineral density of the lumbar spine in patients with ossification of the posterior longitudinal ligament of the cervical spine.

Bone mineral density (BMD) of the lumbar spine in patients with ossification of the posterior longitudinal ligaments of the cervical spine (OPLL) was measured to elucidate the relation of spinal ossification with systemic hyperostotic condition. BMD in the lateral projection had a statistically significant correlation with that in the anteroposterior projection, and the former was considered to reflect the condition more accurately than was the latter, which may include the ossified spinal ligaments. BMD of patients with continuous and mixed types of OPLL was higher than that of those with the segmental type. Patients with OPLL and ossification of the other spinal ligaments had higher BMDs than did those without ossification. These results suggest that the BMD of the lumbar spine may reflect the systemic hyperostotic tendency and advancement of the ossification.

Absorptiometry, Photon↗
PubMed1994

Second-order vestibular neuron morphology of the extra-MLF anterior canal pathway in the cat.

Second-order vestibular neurons form the central links of the vestibulo-oculomotor three-neuron arcs that mediate compensatory eye movements. Most of the axons that provide for vertical vestibulo-ocular reflexes ascend in the medial longitudinal fasciculus (MLF) toward target neurons in the oculomotor and trochlear nuclei. We have now determined the morphology of individual excitatory second-order neurons of the anterior semicircular canal system that course outside the MLF to the oculomotor nucleus. The data were obtained by the intracellular horseradish peroxidase method. Cell somata of the extra-MLF anterior canal neurons were located in the superior vestibular nucleus. The main axon ascended through the deep reticular formation beneath the brachium conjunctivum to the rostral extent of the nucleus reticularis tegmenti pontis, where it crossed the midline. The main axon continued its trajectory to the caudal edge of the red nucleus from where it coursed back toward the oculomotor nucleus. Within the oculomotor nucleus, collaterals reached superior rectus and inferior oblique motoneurons. Some axon branches recrossed the midline within the oculomotor nucleus and reached the superior rectus motoneuron subdivision on that side. Since these neurons did not give off a collateral toward the spinal cord, they were classified as being of the vestibulo-oculomotor type and are thought to be involved exclusively in eye movement control. The signal content and spatial tuning characteristics of this anterior canal vestibulo-oculomotor neuron class remain to be determined.

Animals↗
PubMed1994

Physiological studies of thoracic spinocerebellar tract neurons in relation to respiratory movement.

The differential roles of thoracic spinocerebellar tract (SCT) neurons with axons ascending in ipsi- (uncrossed) and contralaterally (crossed) spinal cord and their activities during respiratory movement were examined by extracellular recordings in the T9-T12 spinal segments of the anaesthetized cat. A total of 36 uncrossed and 7 crossed SCT neurons showed rhythmic discharges in relation to either spontaneous or artificial respiration. Uncrossed neurons were located in and around Clarke's column and thus are cells of origin of the dorsal spinocerebellar tract (DSCT). Crossed neurons were located in laminae VII and VIII. Almost all DSCT neurons were modulated during artificial respiration. Nineteen DSCT neurons showed high-frequency discharges during chest expansion and 15 DSCT neurons showed high-frequency discharges during the chest retraction phase of artificial respiration. Their respiration-related activity maintained the same phase relation and firing patterns after vagotomy. The phase relationship of neural rhythmicity to chest movement during artificial respiration and spontaneous breathing was the same in 14 neurons examined. Artificially induced pneumothorax caused a marked decrease of respiration-related modulation, and severing of a single nerve to the appropriate muscle caused a marked decrease of modulation, suggesting that respiration-related rhythmic activity of DSCT neurons is induced by the extension of respiratory muscles in the chest wall during both spontaneous and artificial respiration. Crossed SCT neurons showed rhythmic activity in phase with the central respiratory rhythm as indexed by phrenic nerve activity. Two neurons received an excitatory influence and five an inhibitory influence in the inspiratory phase from the centre. Four neurons in the latter group also received excitatory inputs from the periphery during chest expansion. Since inspiration brings chest expansion during spontaneous breathing, the central and peripheral inputs seem antagonistic in function. These neurons seemed to signal a discrepancy between the chest wall movement and the central respiratory rhythm. Functional differences between uncrossed and crossed SCTs in the lower thoracic segments in regard to the central and peripheral inputs as observed here are similar to those observed in the lumbar SCTs during locomotion.

Animals↗
PubMed1994

Alteration of immune responses of rabbits infected with bovine immunodeficiency-like virus.

Nine 3-month-old rabbits were inoculated with bovine immunodeficiency-like virus (BIV) to study the pathogenesis of BIV and alteration of the immune responses in experimentally infected rabbits. BIV proviral DNA and anti-BIV antibodies were detected from all rabbits inoculated with BIV-infected bovine embryo spleen (BESP) cells. Rabbits inoculated with spleen cells of the BIV-infected rabbit also converted to proviral DNA-positive and BIV-antibody-positive. The blastogenic responses to concanavalin A of peripheral blood mononuclear cells prepared from BIV-infected rabbits were not significantly different from those from uninfected controls at 2 and 4 months post-inoculation (PI). The humoral immune responses against bovine serum albumin (BSA) were depressed in two of four BIV-infected rabbits at 1 to 3 months PI. The antibody responses against sheep red blood cells (SRBCs) were significantly depressed in all BIV-infected rabbits at 2 to 4 months PI. BIV was rescued by cocultivation of spleen cells of infected rabbits with BESP cells. Distinct development of lymphoid follicle was observed in lymph nodes and spleens of uninfected rabbits which received BSA and SRBCs. In contrast, moderate lymphoid cell depletion was observed in BIV-infected rabbits which received the same immunogens.

Animals↗
PubMed1994

[A case of NIDDM with non-clostridial gas-producing infection in the lower limb--the effects of hyperbaric oxygen therapy].

A 36-year-old male was admitted because of swelling and pain in the lower left limb. He had been diagnosed as having non-insulin dependent diabetes mellitus 4 years previously and had been treated unsuccessfully with insulin. Since gas formation was radiographically demonstrated in the soft tissue of the left foot, we treated him with antibiotics and hyperbaric oxygen under the diagnosis of gas gangrene. Despite this therapy, the gangrenous lesions progressed. Amputation of the left foot was necessary. Peptstreptococcus was isolated from the gangrenous area and identified as such on the seven hospital day. Nine cases of diabetic patients with non-clostridial gas gangrene who were treated with hyperbaric oxygen therapy have been reported in Japan. The results indicated that hyperbaric oxygen therapy is ineffective in the treatment of non-clostridial gas gangrene in diabetic patients.

Adult↗
PubMed1994

[Adult T cell leukemia with cytomegalovirus associated hemophagocytic syndrome].

A 59-year-old woman, diagnosed as adult T-cell leukemia (ATL), was admitted because of fever and disturbance of consciousness. Peripheral blood examination demonstrated leukopenia and anemia, and subsequently thrombocytopenia. Bone marrow aspiration showed the increase of mature histiocytes with hemophagocytosis and a diagnosis of hemophagocytic syndrome (HPS) was established. She died due to respiratory failure on the eighth hospital day. Autopsy histological examination revealed systemic cytomegalovirus (CMV) infection with CMV pneumonia, and also demonstrated the findings of HPS in bone marrow, lymph nodes, and spleen. This case was considered as virus associated hemophagocytic syndrome (VAHS) developed by CMV infection. CMV is one of the causative viruses of VAHS and the opportunistic infection. In the patient with ATL in the immunodeficiency state, VAHS accompanied with opportunistic infection might be one of the causes of pancytopenia.

Cytomegalovirus Infections↗
PubMed1994

[Extramedullary blastic crisis of chronic myelogenous leukemia--a case with various additional chromosomal appearance].

We describe a characteristic case of chromosomal abnormalities in a 47-year-old man with chronic myelogenous leukemia (CML). He had been diagnosed with the chronic phase of CML on May 1990, but he refused treatment. He was readmitted in October 1991 because of peripheral lymphadenopathy. Hematologic studies showed that he remained in the chronic phase of CML. There were no additional chromosomal findings in the bone marrow, but cervical lymph node biopsy revealed complete replacement with blastoid cells. The blasts were positive for CD13 and CD33. DNA analysis for the breakpoint cluster region gene showed rearrangement pattern, but immunoglobulin heavy chain joining region genes and T-cell antigen receptor gene rearrangement were not observed. The karyotype of lymph node cells showed various additional chromosomal abnormalities. Therefore, we concluded that the patient had an extramedullary blastic crisis in his peripheral lymph nodes. Abnormal clones were composed of one main clone and three subclones, with the latter occupying more than 10% of the volume each other. Considering the types of the additional chromosomal abnormalities, all four types of clones were thought to have evolved through independent pathways.

Blast Crisis↗
PubMed1994

Detection of microplatelet formation using an electroimpedance cell counter.

Changes in the platelet size distribution curves during the process of ADP-induced aggregation were observed using a particle distribution analyzer (PDA) based on electronic impedance. The maximum primary aggregation was seen at a final ADP concentration of 3 microM. After stimulation, the platelet distribution curve changed rapidly from a log normal curve to a curve skewed to the left. When the changes were evaluated at 1 min after the addition of ADP, the peak height was increased, and the median and total volume were decreased significantly. These findings indicate that microplatelets are formed by membrane stimulation and this formation can be monitored with the use of this automated instrument.

Adenosine Diphosphate↗
PubMed1993

[Adult T cell leukemia/lymphoma effectively treated with chronic oral etoposide].

A 52-year-old man, who complained of tarry stool and systemic lymphadenopathy, was admitted to our hospital on July 2, 1992. Biopsy showed diffuse large cell lymphoma. Leukocytosis with atypical lymphocytes was not shown in the peripheral blood, but there was an elevated serum LDH level. The man was found to have both HTLV-I antibody and the monoclonal integration of proviral DNA in malignant lymph node cells obtained at biopsy. The diagnosis was lymphoma-type adult T-cell leukemia (ATLL). The chemotherapy regimens of MI-FP, CHOP and modified DHAP were used for the treatment, but were not effective. So, he was treated with etoposide 75 mg orally for 25 days (chronic oral etoposide therapy) and achieved partial remission. This chemotherapy induced myelosuppression with neutropenia, but there was no documented infection. Chronic oral etoposide therapy is an effective regimen for patients with relapse or refractory lymphoma.

Administration, Oral↗
PubMed1991

Mass spectrometric identification of a phorbol diester 12-O-hexadecanoylphorbol-13-acetate, an Epstein-Barr virus-activating substance, in the soil collected from under Sapium sebiferum.

Soil-extracts collected from the ground from under several Euphorbiaceae plants have been known to possess Epstein-Barr virus (EBV)-activating substances which are thought to be one of the environmental co-factors causing nasopharyngeal carcinoma (NPC) in southern part of China and Burkitt's lymphoma (BL) in tropical Africa. Then, a model experiment aimed at chemical characterization of such active substances was carried out using a soil-extract around Sapium sebiferum, a Japanese representative Euphorbiaceae plant. Chromatographic separation guided by the EBV early antigen (EA) inducing activity gave a highly active fraction. Application of this fraction to desorption chemical ionization mass spectrometry identified a major active substance to be 12-O-hexadecanoylphorbol-13-acetate (HPA), which originally occurs in this plant. The method in this model experiment is suggested to be applicable to other samples from the endemic areas of NPC and BL.

Herpesvirus 4, Human↗
PubMed1991

[Changes in the values of estrogen stimulated neurophysin, oxytocin and prostaglandin in the maternal blood after the administration of dehydroepiandrosterone-sulfate to the pregnant women near term].

UNLABELLED: In order to examine the effect of dehydroepiandrosterone-sulfate (DHA-S) on the production of uterus-contractive substances in perinatal women, the concentrations of estrogen stimulated neurophysin (ESN), oxytocin, 13, 14-dihydro-15-keto-Prostaglandin F2 alpha(PGF2 alpha) and DHA-S related steroids in the maternal blood of 12 cases of primigravida were serially estimated after intravenous administration of 200mg DHA-S twice a week from 38 weeks of gestation till the onset of labor. RESULTS: 1) The duration of labor was significantly shortened in the DHA-S group (mean; 9.3 +/- 2.8 hours) compared to the 11 control cases (13.5 +/- 5.2 hours). 2) i) The ESN concentration, which correlated well with that of free estradiol-17 beta, increased significantly at 1 week after the Ist administration. ii) The oxytocin concentration, which correlated well with that of ESN, increased significantly at 39 weeks of gestation, the first stage of labor and especially at delivery compared to the control. iii) The PGF2 alpha concentration, which increased in parallel with those of DHA-S, estrone-S and pregnenolone-S, increased significantly at delivery in comparison with the control and correlated well with estrone-S in the DHA-S group. CONCLUSION: These findings suggest that DHA-S administration to perinatal women may enhance the production of ESN, oxytocin and PGF2 alpha in the fetoplacento-maternal compartment, which may result in the shortening of labor.

Dehydroepiandrosterone↗