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Biomedical subjects

Y Maruyama

Publications and source records attributed to Y Maruyama.

At least 19 recordsLinked to original sources
PubMed1996

Adoptive immunotherapy with tumor-specific T lymphocytes generated from cytokine gene-modified tumor-primed lymph node cells.

Adoptive immunotherapy with immune T cells mediates regression of established tumors in animal models. We previously demonstrated that precursor lymphocytes of sensitized T cells can develop into mature effector cells after in vitro activation with anti-CD3 mAb and IL-2. We demonstrate here that tumor cells genetically modified to secrete IL-2 can enhance the precursor response in the tumor-bearing host and subsequently augment the antitumor efficacy of adoptive immunotherapy. MCA205 and MCA203, weakly immunogenic fibrosarcomas, were transfected in vitro with cDNA encoding for IL-2, IL-4, or IL-6. Lymph nodes (LN) draining these cytokine-producing tumors for 7 days were harvested, activated in vitro with anti-CD3/IL-2, and adoptively transferred into mice bearing established parental MCA205 pulmonary metastases. The effector cells generated from LN draining the IL-2 producing tumor exhibited enhanced antitumor activity compared with cells from LN draining parental, IL-4-producing, or IL-6-producing tumor. Phenotype analysis of cells from LN draining the IL-2-producing tumor revealed selective expansion of V beta 8+ cells. Depletion of V beta 8+ effector cells abrogated the antitumor efficacy indicating that V beta 8+ cells constituted the majority of antitumor reactivity and that secretion of IL-2 from tumor cells promoted the priming of V beta 8+ precursor cells, which can develop into mature effector cells. These results have important clinical implications that the method presented here could be applicable to the treatment of human cancer as more effective immunotherapy.

Animals↗
PubMed1996

Clinical evaluation of extracorporeal shock wave lithotripsy for salivary stones.

The treatment of sialolithiasis is discussed in this report. Generally, stones within the distal salivary duct are easily removed by transoral ductotomy, although proximal stones are usually treated by excision of the salivary gland and its duct. Since 1980, extracorporeal shock wave lithotripsy (ESWL) has been in clinical use for the treatment of renal and gallbladder stones. We used this technique as a treatment for sialolithiasis. We undertook ESWL on 14 submandibular gland stone patients and 1 parotid gland stone patient, clinical symptoms such as pain and swelling disappeared without excision of the affected salivary gland. Stones larger than 10 mm seem to have a tendency to form Steinstrassen. Although computed tomography findings correlate with success in breaking up gallstones, they did not predict success for salivary stones. We conclude that sialolithiasis is treated successfully without adverse effects by ESWL in selected patients.

Adolescent↗
PubMed1995

Application of a novel, plastic formed carbon as a precolumn packing material for the liquid chromatographic determination of acetylcholine and choline in biological samples.

A novel carbon material, plastic formed carbon (PFC), was prepared by mixing various amounts of pure graphite with an organic binder and pyrolysing the mixture to a "glassy carbon" at a modest final temperature of 1000-1400 degrees C. This preparation procedure allows more convenient and precise control of the final graphite adsorption characteristics. Various PFC materials were constructed and tested both as bulk adsorbents and as precolumn packings for the direct determination of ACh and Ch in brain tissue homogenates. The PFC precolumns prepared from 12.5-50% graphite, by mass, were capable of selectively removing interfering species while not adsorbing any of the desired quaternary amine analytes. The usually large solvent front was also dramatically reduced with these precolumns. These PFC precolumns are useful for the direct determination of ACh and Ch in brain tissue homogenates and other biological samples.

Acetylcholine↗
PubMed1995

High expression of c-kit in K562YO cells due to the prolonged half-life of its mRNA: the effects of modification with serine/threonine kinase signals.

We previously reported that the K562 cell line K562YO expressed a high level of the c-kit gene. In this study, we analyzed the mechanism of this expression and investigated the effects of the serine/threonine kinases such as protein kinase C (PKC) and cyclic adenosine 3',5'-monophosphate (cAMP)-dependent kinase (PKA) on it. The half-life of the c-kit mRNA in K562YO cells was greater than 10 hours, compared with 2 hours in the original K562 cells, which expressed a very low level of c-kit mRNA. This prolonged half-life can contribute to the high level of c-kit expression in K562YO cells. Cycloheximide (CHX), a protein synthesis inhibitor, caused increases in c-kit mRNA levels in K562YO cells. 12-O-tetradecanoylphorbol-13-acetate (TPA), by which PKC was activated at first and downregulated in a late phase, gradually decreased c-kit mRNA in K562YO cells until 9 hours and then returned to the control level 24 hours after treatment. TPA also rapidly decreased c-kit protein level on the membranes. In whole cells, c-kit protein was also decreased 6 hours after incubation with TPA. Calphostin C, a light-dependent PKC inhibitor, decreased c-kit mRNA levels within 30 minutes in a light-dependent manner. It also decreased c-kit protein in whole cells 2 hours after the addition. However, it increased the amount of c-kit protein on the cell surfaces. Dibutyryl cyclic AMP (dbc-AMP) increased c-kit mRNA as well as c-kit protein on membranes and in whole cells. Run-on transcriptional assay suggested that the agent (dbc-AMP) enhanced the transcription rate of the gene. These results suggest that c-kit protein on the membranes is downregulated by PKC activation and upregulated by PKC inhibition. In the whole cell lysate, c-kit proteins are decreased by PKC inhibition through downregulation of mRNA. On the other hand, the elevation of an intracellular cAMP level causes upregulation of both the mRNA and c-kit protein on membranes and in whole cells through enhanced transcription. Thus, c-kit gene expression is apparently modulated by PKC and PKA.

Bucladesine↗
PubMed1995

Pentobarbital protects against CA1 pyramidal cell death but not dysfunction of hippocampal cholinergic neurons following transient ischemia.

Effects of pentobarbital on the release of acetylcholine (ACh), the area of CA1 pyramidal cell soma and the immunoreactivity of choline acetyltransferase (ChAT) in the hippocampus following ischemia were investigated. Five minute ischemia significantly decreased the KCl-, atropine-induced and basal release of ACh and the area of CA1 pyramidal cell soma in the hippocampus. Moreover, ChAT immunoreactivity, a marker of pre-synaptic terminal survival in the cholinergic neurons, was lowered 14 days after ischemia-recirculation. Although treatment with pentobarbital (50 mg/kg) 30 min before ischemia provided complete protection against hippocampal CA1 pyramidal cell death, pentobarbital failed to improve the decrements of ACh release and the low ChAT immunoreactivity over the test period. Our study thus showed discrepancies between pre-synaptic neurochemical estimation and post-synaptic morphological observation of the effect of pentobarbital on ischemic damage.

Acetylcholine↗
PubMed1995

Immunohistochemical and neurochemical studies of hippocampal cholinergic neurones after ischaemia.

We investigated alterations in cholinergic neurones in the gerbil hippocampus after ischaemia. The cholinergic function of acetylcholine (ACh) release fluctuated over the test period. Choline acetyltransferase (ChAT) immunoreactivity decreased slightly on day 1 and no ChAT immunoreactivity was observed on or after day 4 after ischaemia. Since ChAT immunoreactivity is a marker of cholinergic terminal survival, post-ischaemic cholinergic dysfunction on and after day 4 was accompanied by the destruction of terminals. However, dysfunction of the cholinergic system without destruction of the terminals is possible since mild ischaemia decreases ACh release in spite of retaining intact ChAT immunoreactivity. In the morphological study, delayed neuronal death in the stratum pyramidale was observed from day 4. The present study shows that presynaptic cholinergic dysfunction occurs in the early stage prior to pyramidal cell death.

Acetylcholine↗
PubMed1995

Ca(2+)-activated K(+)-channels in the nuclear envelope isolated from single pancreatic acinar cells.

The patch-clamp techniques are applied to the outer membrane of the nuclear envelope isolated from rat pancreatic acinar cells. The nucleus identified under an inverted microscope was removed by cell surgery from enzymatically dispersed single cells. All the patch-clamp techniques, in situ, excised, and whole-material recordings were applied to the envelope. We have found voltage- and Ca(2+)-activated K(+)-channels with an unitary conductance of 200 pS in the outer membrane. The channels are activated by lumen positive potentials and by an increase in luminal Ca2+ concentration. They may play a role for controlling Ca(2+)-release from the lumen of the nuclear envelope (endoplasmic reticulum) to the nucleoplasm and the perinuclear cytoplasm.

Animals↗
PubMed1995

Cognitive function in rats with alcohol ingestion.

The effect of alcohol ingestion on learning disturbances was tested in rats. Rats were fed either an alcohol solution or a nonalcohol solution. The concentration of acetylcholine in the whole brain was significantly lower in rats fed with alcohol than rats fed without alcohol. Passive avoidance learning shows a lower tendency in rats with alcohol compared to rats without alcohol, but the alcohol and control groups did not differ in passive avoidance learning. We suggest that alcohol may disturb acetylcholine metabolism in the brain.

Animals↗
PubMed1995

Effects of erythropoietin, IL-3, IL-6 and LIF on a murine megakaryoblastic cell line: growth enhancement and expression of receptor mRNAs.

We examined the effects of recombinant human erythropoietin (rhEPO), recombinant murine interleukin 3 (rmIL-3), recombinant human interleukin 6 (rhIL-6), recombinant human interleukin 11 (rhIL-11), recombinant murine leukemia inhibitory factor (rmLIF) and recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) on the growth of murine megakaryocytic cell lines. In serum-free methylcellulose culture supplemented with bovine serum albumin (BSA), the addition of rhEPO (0.1-10 U/ml), rmIL-3 (10-500 U/ml), rhIL-6 (100-10,000 U/ml), rmLIF (100-10,000 U/ml), or rmGM-CSF (10-1000 U/ml) enhanced colony growth in L8057Y5 cells, which had been maintained in protein-free culture, mostly in a dose-dependent fashion; rhIL-11 did not have any stimulatory effect at the tested doses (10-1000 U/ml). In addition, colony growth of L8057 cells, which had been maintained in serum-containing culture, was enhanced, but to a lesser extent, by the addition of these cytokines except rhEPO (the cultures were supplemented with 1% fetal bovine serum. Among the cytokines that showed growth-enhancing effects on L8057 cells, the expression of mRNAs encoding receptors for EPO, IL-6 and IL-3 was examined by northern blot analysis or reverse transcription polymerase chain reaction (RT-PCR). In both cell lines, mRNAs for EPO-R, IL-6R, gp130, IL-3R alpha and beta chains were constitutively expressed. The results suggest that L8057 and L8057Y5 cell lines have characteristics of megakaryoblastic cells in their biological responses to cytokines, as well as in the expression of cytokine receptor mRNAs, and that the growth-enhancing effects of these cytokines on the cell lines may be achieved through specific receptors. Our findings show the value of these cell lines for investigating the mechanisms of growth signal transduction in megakaryopoiesis.

Animals↗
PubMed1995

Erythroid differentiation and growth inhibition of K562 cells by 2',5'-dideoxyadenosine: synergism with interferon-alpha.

We found that 2',5'-dideoxyadenosine (DDA), a P-site specific adenylate cyclase inhibitor, inhibited the growth of K562 cells and caused them to become benzidine positive. The continuous exposure of cells to DDA was needed to recruit cells for growth inhibition and differentiation. Fetal calf or human sera were also necessary for DDA to induce differentiation. DDA at a concentration of 1.5 mM with serum induced 98% of the cells to produce hemoglobin and inhibited their growth to 15% of that of the control. An increase of epsilon-globin mRNA and a decrease of c-myc and c-myb mRNA occurred only during differentiation in the presence of fetal calf serum (FCS). An incubation with DDA and interferon-alpha (IFN-alpha) or hemin synergistically induced more benzidine-positive cells than in the presence of DDA alone, although IFN-alpha did not trigger differentiation by itself. The erythroid differentiation and growth inhibition were, however, not related to a decreased intracellular cyclic AMP (cAMP) concentration induced by DDA. The simultaneous incubation with dibutyryl cyclic AMP (dbc-AMP) and DDA enhanced the effects of DDA. Adenine, a possible metabolite of DDA digestion by purine nucleoside phosphorylase (PNP), also induced erythroid differentiation in K562 cells. However, it did not act synergistically with IFN-alpha.

Adenine↗
PubMed1995

Colonic dilatation due to dialysis-related amyloidosis.

A 66-year-old woman with chronic renal failure who had undergone hemodialysis for 15 years developed severe dilatation of the ascending and transverse colon. She had received right carpal tunnel release 5 years before this episode. The follow-up study of upper gastrointestinal series disclosed marked dilatation of the ascending and transverse colon with the retention of gastrografin persisted for 5 days, whereas colonic fiberscope showed no obstructive lesion. Pathologic study of biopsy specimens obtained from the colon demonstrated amyloid deposition. Avidin-biotin peroxidase complex method showed that these deposits strongly reacted with the antibody to human beta 2-microglobulin, but did not react with AA, lambda, and kappa antibodies. This case suggests that dialysis-related amyloidosis can cause intestinal pseudo-obstruction.

Aged↗
PubMed1995

Decrease of norepinephrine and preservation of acetylcholine in the hypothalamus of VMH obese rats.

We investigated to find which types of neuronal disturbance in the hypothalamus are responsible for ventromedial hypothalamic nucleus (VMH) lesion-induced development of obesity. We found that in VMH-lesioned obese rats, the contents of norepinephrine (NE) and dopamine in the hypothalamus were selectively decreased, but that the serotonin and acetylcholine levels were unchanged from those in sham controls. Also, the content of NE in the lateral portion of the hypothalamus was decreased. Our results show that disturbance of the hypothalamic noradrenergic and dopaminergic neurons, but not of the serotonergic or cholinergic neurons, contributes to the development of VMH lesion-induced obesity.

Acetylcholine↗
PubMed1995

Infrared angiography of the anterior ocular segment.

We performed angiography with indocyanine green (ICG) and fluorescein using a scanning laser ophthalmoscope (SLO) in the anterior segments of seven normal and 35 diseased eyes. ICG angiography revealed the radical stromal vessels and minor arterial circle in brown irides, which were not detected by fluorescein angiography. High penetration of infrared fluorescence through the pigmented tissue and absence of extravasation of ICG facilitated demonstration of the fine structure of iris rubeosis and its origins from stromal vessels. In 11 diabetic eyes, the iris rubeosis showed three basic patterns of location: along the pupillary margin; originating from the iris root; and arising from stromal radial vessels near the collarette. ICG gonioangiography with SLO showed fine structure of angle rubeosis because of its high resolution and greater depth in focus. Rubeotic vessels in the chamber angle were perfused by neovascular trunks which arose from the iris root in all 12 rubeotic eyes. Rubeosis in the iris and the angle consistently showed no extravasation of the ICG dye, while fluorescein quickly leaked out. ICG angiography with SLO in the anterior ocular segment proved to be a useful means to study the structure and the hemodynamics of normal and newly formed vessels.

Adult↗
PubMed1995

Intra-operative scalp expansion for wound closure without tension in craniosynostosis operation--technical innovation.

Primary scalp wound closure using intra-operative scalp expansion in a craniosynostosis operation is described. Since this method enables easy scalp expansion, it is considered to be a useful adjunctive technique which should be taken into account when closing scalp wounds in craniosynostosis surgery, where the risk exists of cranial expansion-induced compression and deformity of the remodelled bone flaps after bone fixation.

Craniosynostoses↗
PubMed1995

Vertical double flap design for repair of wide defects of the lower limb, using combined ascending scapular and latissimus dorsi flaps.

Two cases are presented in which a scapular osteocutaneous flap and a latissimus dorsi musculocutaneous flap were applied as combined flaps with a single pedicle, to repair massive soft-tissue defects resulting from tibial hemisection in the lower limb. In each case, the oval-shaped donor site was divided into two parts (an ascending scapular flap and a latissimus dorsi flap, respectively) to repair the resected area, using a vertically designed, combined flap from the dorsolateral region. Consequently, after flap elevation, the donor site could be closed primarily and functions of the affected limb could be completely reconstructed. For reconstruction of defects too large to be covered with a single flap, the vertical double flap design of a combined ascending scapular and latissimus dorsi flap is a good alternative. It has the merits of easy dissection, broad area skin coverage and it also provides a composite flap that contains a scapular bone graft. Moreover, it allows a simple microsurgical anastomosis, as well as direct closure of the donor site. In addition, when the recipient site is on the lower leg, flap elevation can be carried out simultaneously with surgery at the recipient site. This means that the operative time can be shortened.

Aged↗
PubMed1995

Buttock deformity repair for congenital generalized lipodystrophy.

A 3-year-old girl suffering from congenital generalized lipodystrophy is presented. Almost all features of CGL described by Seip were found in our patient. The deformity of the patient's buttocks was repaired using bilateral gluteus maximus muscle flap advancement, with good result.

Buttocks↗
PubMed1995

A hemophiliac with human immunodeficiency virus (HIV)-1-associated dementia complex.

We report a 29-year-old male hemophiliac with human immunodeficiency virus (HIV)-1-associated dementia complex, who died 2.5 months after the onset of dementia. The patient's cognitive abnormalities including forgetfulness, loss of concentration and slowing of thought appeared about 7 years after HIV infection. His neurological symptoms were characterized as progressive dementia, episodic consciousness loss, transverse myelopathy and peripheral neuropathy. He had generalized slow waves in electroencephalogram (EEG), progressive cerebral atrophy and a diffuse high intensity lesion in the white matter as shown by T2-weighted brain magnetic resonance imaging (MRI). We emphasize the significance of neurological complications, especially acute progressive dementia, in Japanese patients with acquired immunodeficiency syndrome (AIDS).

AIDS Dementia Complex↗