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Biomedical subjects

S Homma

Publications and source records attributed to S Homma.

At least 253 records · Page 14Linked to original sources
PubMed1991

Application of plasma perfusion in hepatic failure.

To evaluate the efficacy of plasma perfusion as a liver-assistance system, 17 patients with hepatic failure were treated with a total 37 sessions of plasma perfusion and 43 sessions of plasma exchange. For plasma perfusion, Plasma-flo AP-08-H was used as a plasma separator, and the separated plasma was passed through an adsorber, Bespore UPC-III (Jap.Med.Suppl., Hiroshima) or BR 350 (Asahi Med. Co., Tokyo). The mean treated plasma volume was 5.0 liters. The mean proportion of bilirubin removed by routine plasma exchange was 29% with a mean of plasma exchange volume of 2.1 L. In the plasma perfusion with Bespore and BR, the removal rates were 37% and 42%, respectively. The plasma ammonia level decreased by 16% (from 121 to 97 mumol/L) with plasma exchange. Likewise, plasma perfusion decreased the plasma ammonia level from 75 to 56 mumol/L with an average decrement rate of 23%. The capacity for removal of amino acids was analyzed in terms of the change in the Fisher score ([Val+Leu+Ileu]/[Tyr+Phe]). The Fisher score was improved by plasma perfusion from 1.8 to 2.4. Thus, we concluded that in terms of removal of bilirubin, ammonia and amino acids, plasma perfusion was as efficient a therapy as plasma exchange. However, further clinical evaluation will be required before this procedure can be applied for the treatment of hepatic failure.

Adult↗
PubMed1991

Vitamin D3 binding protein required for in vitro activation of macrophages after alkylglycerol treatment of mouse peritoneal cells.

In vitro treatment of peritoneal cells with dodecylglycerol (DDG) in 10% foetal calf serum (FCS) supplemented medium RPMI-1640 results in a greatly enhanced Fc receptor-mediated phagocytic activity of macrophages. This macrophage activation process requires a serum factor in the alpha 2-globulin fraction. When mouse peritoneal cells were treated with 50 ng DDG/ml in a serum-free 0.1% egg albumin-supplemented medium RPMI-1640 (EA medium) for 30 min and cultured in EA medium containing electrophoretically fractionated alpha 2-globulin for 3 hr, a markedly enhanced activation of macrophages was observed. To improve fractionation of alpha 2-globulin, FCS was first precipitated with 50% saturated ammonium sulphate and then the supernatant electrophoretically fractionated. The resultant alpha 2-globulin fraction was unable to support activation of macrophages. Vitamin D3 binding protein (DBP) of the alpha 2-globulin fraction is known to be precipitable by 50% saturated ammonium sulphate. When human alpha 2-globulin was treated with antiserum against human DBP and used in a medium for cultivation of DDG-treated peritoneal cells, no significant activation of macrophages was observed. Cultivation of DDG-treated peritoneal cells in a medium containing a low concentration of purified human DBP (group specific component, Gc) produced a greatly enhanced ingestion activity of macrophages. Purified human Gc protein, when used in an EA medium for step-wise cultivation of DDG-treated B and untreated T cells, was efficiently converted to a macrophage-activating factor.

Animals↗
PubMed1991

[A case of Legionnaires' disease cured with a combination of erythromycin and steroid therapy].

A 53-year-old male was admitted to Keio University Hospital with a pneumonia shadow in the left lung field and respiratory failure. Because there was progression of respiratory failure, mechanical ventilation was required to maintain appropriate oxygenation. Although erythromycin administration was started at the time of admission, a steroid (prednisolone 60 mg/day) was added a few days later to temporarily inhibit the acute inflammatory response in the lung parenchyma. This intensive therapy resulted in resolution of the patient's pneumonia and improvement of his respiratory failure. No pathogens were detected in the clinical specimens. Indirect immunofluorescence examination demonstrated a marked increase in titers against Legionella pneumophila serogroup 1, which was sufficient to confirm a diagnosis of Legionnaires' disease. The causative organism of this disease, a gram-negative short rod, is rarely cultured on conventional culture media. Two clinical subtypes are known based on clinical manifestations: 1) the Pontiac fever-type in which the predominant symptom is fever alone; and 2) the pneumonia-type which was observed in the epidemic in Philadelphia when the disease was first reported in 1976. The present case of Legionnaires' disease was the severe pneumonia-type which was successfully treated with a combination of erythromycin and a steroid.

Drug Therapy, Combination↗
PubMed1990

Generator mechanisms of epileptic potentials analyzed by dipole tracing method.

A new dipole tracing method, based on a realistic head model, was used to determine dipole locations and vector moments of interictal convexity sharp waves recorded (with conventional EEG technique) from the right fronto-temporal region in a patient with partial complex seizures. When the dipole locations in the head model were compared to MRI scans, the majority of the sharp wave dipoles were found to be located in the right hippocampal area. For individual sharp waves, the hippocampal dipoles moved along tracks corresponding to the vector moment directions, suggesting that the electrical sources of the convexity sharp waves were somato-dendritic currents which spread rapidly from one neuron group to the next in the hippocampal area. Previous long-term subdural recording had shown seizure onset in this area. After right-sided anterior temporal lobectomy including the hippocampus the patient has been seizure-free for three months.

Adult↗
PubMed1990

Conduction velocity of motor nerve and cervical sympathetic and vagus nerve in streptozotocin diabetic rats.

We investigated the conduction velocity of motor and autonomic nerves, motor nerve to foot interosseous muscle and cervical vagus and sympathetic nerve, in streptozotocin diabetic rats (1-3 months duration of diabetes) and compared it with that of age-matched controls. In diabetic rats, the motor nerve conduction velocity was significantly reduced but the conduction velocity of cervical vagus and sympathetic nerves was not reduced.

Adrenergic Fibers↗
PubMed1990

Dipole-tracing of abnormal slow brain potentials after cerebral stroke--EEG, PET, MRI correlations.

A patient with major neurological deficits 5 years after a left cerebral infarction underwent correlative EEG, MRI and PET studies of cerebral blood flow and oxygen metabolism. The EEG showed abnormal slow electroencephalographic activity in the frontopolar region. The intracranial location of the slow electrical activity was estimated, as an equivalent current dipole, by using a newly developed dipole tracing (DT) method. The DT analysis showed that the dipole equivalent of the slow wave is approximately located at the frontal part of the left cingulate gyrus, away from the margins of the infarction and enlarged left lateral ventricle demonstrated by MRI, and in a region with intact oxygen consumption rate. The genesis of the slow wave is discussed.

Adult↗
PubMed1990

Distribution patterns of dendrites in motor neuron pools of lumbosacral spinal cord of the chicken.

The morphology of dendritic trees (dendroarchitecture) of motor neurons innervating specific hindlimb muscles (motoneuron pools, MNP) was studied in the chick spinal cord. Motoneurons were labelled by intramuscular injections of horseradish peroxidase conjugated with cholera toxin subunit B. MNPs of posterior iliotibial and femorotibial muscles were located at the dorsolateral part of lateral motor column of lumbosacral segments (LS) 1-4 and 1-3, respectively. Although the dendritic profiles of femorotibialis motoneurons were fewer than those of posterior iliotibialis, these two MNPs had a similar distribution pattern of dendrites. Dendritic profiles were about equally distributed in the gray and white matter. Dendrites from the MNP of posterior iliotibialis radiated in all directions. A large number of dendrites penetrated into the white matter, and some even reached to the subpial regions of the lateral funiculus. One array of dendrites that projected dorsomedialwards extended to the base of the posterior horn. MNPs of both the iliofibularis (LS 4-7) and caudilioflexorius (LS 6-8) had dendritic trees with similar distribution patterns. There were two main arrays of dendritic extensions; one along the dorsal, and another along the ventral border of the lateral motor column. Dendrites from the iliofibularis and caudilioflexorius motoneurons were located more frequently in the white matter than in the gray matter. A large number of dendrites extended in all directions from the MNP of the adductor muscle, which was located in the medial region of lateral motor column of LS 1-2. The distribution of dendrites from a few other MNPs was also examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Do optimal dipoles obtained by the dipole tracing method always suggest true source locations?

Scalp potentials generated by a concentrated electric source in the brain are very similar to potentials generated by an electric dipole at the source position. In this sense a concentrated source in the brain is modelled as an electric dipole. When the source is diffuse such a dipole which best approximates the scalp potential is called an optimal dipole. Its position is calculated by the Dipole Tracing Method based on a realistic head model with homogeneous electric conductivity. There are 2 major difficulties inherent in this method: (1) The low electric conductivity of the skull causes systematic shifts of the optimal dipole positions from the true positions of concentrated sources; (2) the optimal dipoles cannot specify diffuse source positions. The first difficulty is overcome by using the numerical correction obtained by comparing the known dipole positions generated within a human head with their optimal ones. The second difficulty is removed to a certain extent by comparing the optimal dipole positions obtained with the 1-dipole and 2-dipole models together with their dipolarity. We have obtained criteria for the validity of the dipole approximation and source concentration.

Brain↗
PubMed1990

Naturally occurring and induced neuronal death in the chick embryo in vivo requires protein and RNA synthesis: evidence for the role of cell death genes.

Treatment of chick embryos in ovo for 10-12 hr with inhibitors of protein and RNA synthesis during the peak time of normal cell death (Embryonic Day 8) for motoneurons and dorsal root ganglion cells markedly reduces the number of degenerating neurons in these populations. The massive neuronal death induced by the early absence of the limbs was also blocked almost completely by these agents. Further, the death of neurons following peripheral axotomy at the end of the normal cell death period (Embryonic Day 10) was reduced significantly by treatment with inhibitors of biosynthetic reactions. These results indicate that, in vivo, naturally occurring neuronal death, neuronal death induced by the absence of peripheral targets, and axotomy-induced neuronal death later in development all require active gene expression and protein and RNA synthesis. Therefore, neuronal death in a variety of situations may reflect the expression of a developmental fate that can normally only be overridden or suppressed by specific environmental signals (e.g., neurotrophic molecules).

Animals↗
PubMed1990

A serum factor for macrophage activation after in vitro dodecylglycerol treatment of mouse lymphocytes.

Alkylglycerols, inflammation products of cancerous tissues, are potent macrophage activating agents. A brief in vitro treatment (30 min) of mouse peritoneal cells with a low concentration (50 ng/mL) of dodecylglycerol (DDG) in 10% foetal calf serum supplemented RPMI-1640 medium (FCS medium) activates macrophages for Fc-receptor mediated ingestion activity. A serum factor(s) was shown to be required for the activation of macrophages. When non-adherent cells were treated with rac-sn-1(3)-dodecylglycerol (DDG) in a serum free-0.1% egg albumin supplemented RPMI medium (EA medium) for 30 min and cultured in FCS medium for 2 h, the resultant conditioned medium contained a signal factor able to activate macrophages (macrophage activating factor). A conditioned medium prepared with electrophoresed serum alpha 2-globulin fraction in EA medium markedly enhanced activation of macrophages. Incubation of DDG-treated non-adherent cell ghosts in EA medium containing alpha 2-globulin also produced the macrophage activating signal factor. Therefore, it is concluded that a serum factor in alpha 2-globulin fraction is processed by pre-existing functions or enzymes of DDG-treated non-adherent cell membrane to yield a macrophage activating signal factor.

Alpha-Globulins↗
PubMed1990

Activation process of macrophages after in vitro treatment of mouse lymphocytes with dodecylglycerol.

Alkylglycerols, inflammation products of cancerous membrane lipids, efficiently activate macrophages. A brief in vitro treatment (30 min) of peritoneal cells (mixture of non-adherent and adherent cells) with a small amount (50 ng/ml) of synthetic dodecylglycerol (DDG) resulted in greatly enhanced Fc-receptor-mediated ingestion activity of macrophages. However, treatment of adherent cells (macrophages) alone with DDG produced no significant enhancement of macrophage ingestion activity, implying that macrophage activation requires a contribution of non-adherent cells. DDG-treated non-adherent cells were found to generate a macrophage-activating signal factor. Studies with a serum free-0.1% egg albumin-supplemented RPMI 1640 medium revealed that a serum factor is essential for macrophage activation process. Time course analysis of stepwise transfers of conditioned media of DDG-treated or untreated B cells and T cells revealed that DDG-treated B cells rapidly transmit a factor to untreated T cells which yield the ultimate macrophage-activating factor. This signal transmission among these cells for the macrophage activation process is too rapid to allow time for synthesis of inducible gene products. Thus, we hypothesized that a serum factor is modified by the pre-existing function of DDG-treated B cells and further modified by the pre-existing function of untreated T cells to yield macrophage-activating factor. This hypothesis was confirmed by the demonstration that DDG-treated splenic non-adherent cell ghosts modify a serum factor to yield macrophage-activating factor.

Animals↗
PubMed1990

Identification of early developing axon projections from spinal interneurons in the chick embryo with a neuron specific beta-tubulin antibody: evidence for a new 'pioneer' pathway in the spinal cord.

The early development of interneurons in the chick embryo spinal cord was studied using a monoclonal antibody against a neuron-specific beta-tubulin isoform. Early developing interneurons were divided into two cell groups on the basis of their location and the pattern of growth of their axons. One group is composed of cells that establish a primitive longitudinal pathway (PL-cells), whereas the other group contains cells constituting a circumferential pathway (C-cells). The onset of axonal development in both cell groups occurs at stage (st.) 15 (embryonic day, (E), 2) in the branchial segments, which is prior to axonogenesis of motoneurons. PL-cells develop in the region between the floor plate and the motoneuron nucleus. Their axons are the first neuronal processes ('pioneer axons') to arrive in the ventrolateral marginal zone and they project both rostrally and caudally to establish a primitive longitudinal association pathway at the ventrolateral surface of the neural tube. This pathway is formed before axons of C-cells arrive in the ventrolateral region. The first C-cells are initially located in the most dorsal portion of the neural tube, whereas later appearing C-cells are also located in both intermediate and ventral regions of the neural tube. The axons of C-cells project ventrally, without fasciculating, along the lateral border of the neural tube. Some of their axons enter the ipsilateral ventrolateral longitudinal pathway at st. 17. We often observed apparent contacts and interactions between preexisting axons of PL-cells and newly arriving axons of C-cells. The axons of commissural C-cells first enter the floor plate at st. 17 and cross the midline at st. 18. Axons of C cells begin to join the contralateral ventrolateral longitudinal pathway at st. 18+ to st. 19. In the floor plate region, contacts between growth cones and axons were often observed. However, axons in the floor plate at these stages were not fasciculated. These observations establish the timing and pattern of growth of axons from two specific populations of early developing interneurons in the chick spinal cord. Additionally, we have identified an early and apparently previously undescribed 'pioneer' pathway that constitutes the first longitudinal pathway in the chick spinal cord.

Animals↗
PubMed1990

Echocardiographic observations in survivors of acute electrical injury.

This report describes for the first time (to our knowledge) persistent left ventricular dysfunction in survivors of electrical injury. Two young men who were resuscitated following electrocution by high tension wires underwent echocardiographic examination after injury. Early studies demonstrated wall motion abnormalities with no to only partial recovery on follow-up. In contrast to a previous report of totally reversible left ventricular dysfunction in a similar setting, these cases suggest that the degree of permanent dysfunction following electrical injury is variable.

Acute Disease↗
PubMed1990

In vitro motor activity and compliance of the caecum in streptozotocin diabetic rats.

In order to characterize the diabetic gastrointestinal disorders such as constipation, the motor activity and the compliance of the caecum of streptozotocin diabetic rats were studied in vitro. The time course of enlargement of the caecum was also examined. Significant enlargement of the caecum was noticed in diabetic rats, 10 days after streptozotocin injection (65 mg/kg). It reached two times heavier in 30 days and three times in 90 days when compared with age-matched controls. The motor activity as studied by in vitro recording of the intraluminal pressure changes associated with spontaneous activity revealed the depression both in amplitude and frequency. The compliance was noticed to be significantly increased in the diabetic caecum as compared to age-matched controls when studied by passive Krebs solution injection. Threshold intraluminal pressure for inducing the reflex motor activity of the diabetic caecum was larger than that of the normal. These factors may contribute to the retention of content inside of the diabetic caecum.

Animals↗
PubMed1990

Maltooligosaccharide composition of flours, weaning foods, and gruels prepared from germinated rice, corn, mungbean, and cowpea.

Germinated rice, corn, mungbean, cowpea, and weaning foods prepared from their selected combinations were studied for their saccharide profile by TLC, total and soluble sugars content, and amylase activities in the flour and gruel samples. The enzyme system present in the germinated materials resulted in the partial digestion of carbohydrates into maltooligosaccharides, as shown by TLC pattern and soluble sugars determination of all materials germinated for 48, 72, and 96 h. Rice had the highest concentration of amylase, followed by cowpea, corn, and mungbean. The amylolytic activity produced during germination was retained in the flour despite drying and roasting processes involved. The processes of germination and gruel preparation of germinated materials contributed to the digestibility of weaning foods prepared from cereals and legumes.

Amylases↗