Search PubMed⌕ Search

Biomedical subjects

K Nagashima

Publications and source records attributed to K Nagashima.

At least 325 records · Page 18Linked to original sources
PubMed1993

Glycosphingolipids of human peripheral nervous system myelins isolated from cauda equina.

Compositions of neutral and sulfated glucuronyl glycosphingolipids purified from human motor and sensory nerves and myelins were studied. Higher neutral glycosphingolipids (fraction B), which were separated from GalCer (fraction A), were analyzed by TLC and TLC-immunostaining. Both nerve myelins contained paragloboside (nLc4Cer) and nLc6Cer dominantly as major higher glycosphingolipids and very little globoside (Gb4Cer), whereas both nerves contained Gb4Cer and nLc4Cer. Besides these major glycosphingolipids, a neutral glycolipid containing asialoGM1 (Gg4Cer) epitope and other minor components such as ceramide trihexoside and ceramide dihexoside were detected in both nerves and their myelins. Furthermore, sulfated glucuronyl nLc4Cer and nLc6Cer, which were monoclonal antibody HNK-1 reactive glycolipids, were detected in both nerves and myelins.

Cauda Equina↗
PubMed1993

Characterization of bovine immunodeficiency virus rev cDNAs and identification and subcellular localization of the Rev protein.

One of the six putative accessory genes of bovine immunodeficiency virus (BIV) is similar to those identified as rev in the human immunodeficiency virus and visna virus genomes. To further analyze the BIV rev gene locus, protein, and function, rev cDNAs were cloned and characterized. BIV rev mRNA is derived from the full-length transcript by multiple splicing events and consists of three exons, including the untranslated leader sequence and two coding exons. BIV rev cDNA was expressed in bacteria and in a mammalian in vitro translation expression system. A 23-kDa Rev protein (p23rev) was immunologically detected in lysates from both systems by using an antiserum made to a synthetic Rev peptide. Recombinant p23rev made in bacteria was purified and used to make a polyvalent antiserum. Antisera to Rev peptide and recombinant p23rev immunoprecipitated p23rev from BIV-infected mammalian cells but not from virions. A mammalian expression vector using the BIV rev cDNA was constructed; p23rev was immunoprecipitated with anti-Rev serum from 32P-labeled lysates of monkey cells transfected with this plasmid, demonstrating that BIV Rev is phosphorylated. Immunofluorescence and immunoelectron microscopy with anti-BIV Rev antisera localized Rev in the nucleus and, particularly, in the nucleoli of BIV-infected cells. In functional studies, the expression of BIV Rev was shown to positively regulate the appearance both of Gag protein, which is translated from the unspliced primary viral transcript, and of singly spliced env mRNA but not that of the multiply spliced tat mRNA. These results demonstrate that BIV Rev activity correlates with the known function of lentivirus Rev proteins.

Amino Acid Sequence↗
PubMed1993

Both the SH2 and SH3 domains of human CRK protein are required for neuronal differentiation of PC12 cells.

Human CRK protein is a homolog of the chicken v-crk oncogene product and consists mostly of src homology region 2 (SH2) and SH3, which are shared by many proteins, in particular those involved in signal transduction. SH2 has been shown to bind specifically to phosphotyrosine-containing peptides. We report here that both SH2 and SH3 are required for signaling from CRK protein. Microinjection of the CRK protein induced neurite formation of rat pheochromocytoma cell line PC12. This activity was abolished by mutation of the CRK protein in either SH2 or SH3. The neuronal differentiation induced by the CRK protein was blocked by an excess amount of peptides containing CRK SH3. Moreover, we identified three proteins, of 118, 125, and 136 kDa, which bound specifically to CRK SH3. The CRK-induced neuronal differentiation was also suppressed by monoclonal antibodies against either CRK SH2 or p21ras. These results suggest that both SH2 and SH3 of the CRK protein mediate specific protein-protein binding and that the resulting multimolecular complex generates a signal for neurite differentiation through activation of p21ras.

Amino Acid Sequence↗
PubMed1993

MRI-pathological correlate of brain lesions in a necropsy case of HTLV-I associated myelopathy.

A postmortem case of HTLV-I associated myelopathy (HAM)/tropical spastic paraparesis (TSP) with a history of remission and exacerbation of neurological signs and symptoms, resembling those of multiple sclerosis is reported. MRI analysis revealed lesions in the periventricular white matter in addition to atrophy of the thoracic spinal cord, characteristic of HAM/TSP. The cerebral periventricular areas consisted of ill-defined paucity of myelin sheaths with astrocytic gliosis and hyaline thickening of blood vessels. The poorly demarcated white matter lesions found in both brain and spinal cord were different from plaques found in multiple sclerosis. It is suggested that, in some cases of HAM/TSP, inflammatory lesions that destroy myelin can involve not only the spinal cord but also the cerebral periventricular white matter.

Astrocytes↗
PubMed1993

Transport of triiodothyronine by erythrocytes from premature and term infants.

To analyze hypothyroxinemia in low birth weight (LBW) infants, the initial uptake of T3 into erythrocytes from term and premature infants was measured. Thirty-eight infants and 18 prepubertal children as controls were subjected in this study. The infants were divided into group 1 (premature infants; below 2,500 g, n = 12) and group 2 (term infants; 2,501-3,500 g, n = 26). Infants with LBW for gestational age were excluded from this study. Vmax for group 1 (mean +/- SE, 6.4 +/- 0.5 pmol/min/10(8) cells), having low thyroid hormone levels, was significantly less than in group 2 (9.0 +/- 0.7 pmol/min/10(8) cells; p < 0.05). Mean Vmax for both groups exceeded normal controls (3.9 +/- 0.3 pmol/min/10(8) cells; p < 0.01). Km in the perinatal period varied widely and was essentially the same as in the normal controls. These findings indicate that T3 uptake by erythrocytes of newborns may possibly be high regardless of maturation stage and blood levels of thyroid hormones may be reflected not by change in the affinity of the transport system but by that in the number of membrane carriers.

Biological Transport↗
PubMed1993

A new point mutation in the deoxyribonucleic acid-binding domain of the vitamin D receptor in a kindred with hereditary 1,25-dihydroxyvitamin D-resistant rickets.

Hereditary 1,25-dihydroxyvitamin D [1,25-(OH)2D]-resistant rickets (HVDRR) is a rare disorder characterized by rickets, alopecia, hypocalcemia, secondary hyperparathyroidism, and normal or elevated serum 1,25-dihydroxyvitamin D levels. We describe a patient with typical clinical characteristics of HVDRR, except that elevated levels of serum phosphorus were present coincident with increased levels of serum intact PTH. The patient was treated with high dose calcium infusion after an ineffective treatment with 1 alpha-hydroxyvitamin D3; serum calcium and phosphorus as well as intact PTH and alkaline phosphatase levels were normalized. Evaluation of phytohemagglutinin-activated lymphocytes derived from this patient revealed that 1,25-(OH)2D3 was unable to inhibit thymidine incooperation, a result that contrasts with the capacity of 1,25-(OH)2D3 to inhibit uptake into normal activated lymphocytes. 1,25-(OH)2D3 did not induce human osteocalcin promoter activity after transfection of this DNA linked to a reporter gene into patient cells. Cointroduction of a human vitamin D receptor (VDR) cDNA expression vector with the reporter plasmid, however, restored the hormone response. Evaluation of extracts from the patient cells for VDR DNA binding revealed a defect in DNA binding. Analysis of genomic DNA from the patient's cells by PCR confirmed the presence of a point mutation in exon 2 of the VDR. This exon directs synthesis of a portion of the DNA-binding domain of the receptor. We conclude that the genetic basis for 1,25-(OH)2D3 resistance in this kindred with VDR-positive HVDRR is due to a single base mutation in the VDR that leads to production of a receptor unable to interact appropriately with DNA.

Binding Sites↗
PubMed1993

Incidence of acetylcholine-induced spasm of coronary arteries subjected to balloon angioplasty.

To examine the vasospastic activity of coronary arteries which have been subjected to previous balloon angioplasty, we conducted an acetylcholine provocative test at diagnostic catheterization in 147 consecutive patients. All patients underwent successful elective angioplasty and had follow-up angiography 1 to 6 months after the procedure. Sixty-two patients had a history of prior myocardial infarction and 43 patients had multivessel coronary artery disease. Angioplasty was performed on 176 vessels. Incremental doses of acetylcholine (25 micrograms, 50 micrograms, 100 micrograms) were injected into the right and left coronary arteries over a period of 1 min. The incidence of coronary spasm of arteries which had been subjected to angioplasty was 44%. Angiographic restenosis was observed in 59 patients (40%). There was no correlation between the occurrence of coronary spasm and the presence of restenosis. The maximal dose of injected acetylcholine was smaller in patients with positive evidence of spasm than in patients with negative evidence of spasm (55 +/- 27 micrograms vs 82 +/- 28 micrograms, p < 0.01). In patients with single vessel coronary artery disease, the incidence of spasm of the contralateral artery, i.e. the artery without angioplasty, was lower than that of the artery subjected to angioplasty (22% vs 46%, p < 0.01). Thus, the data suggest that coronary arteries which have been previously subjected to angioplasty have enhanced vasospastic activity in response to acetylcholine.

Acetylcholine↗
PubMed1993

Desmoplastic infantile ganglioglioma--case report.

A desmoplastic infantile ganglioglioma occurred in a 5-month-old boy, manifesting as delayed psychomotor development. Computed tomography showed a large cystic mass involving the left occipitoparietal lobes. The tumor was totally removed. He has survived for 13 years without tumor recurrence. Histological examination disclosed marked desmoplasia intermixed with mature-looking ganglion cells, neoplastic glial cells, and small, immature round cells. These clinical and histological features enabled the diagnosis of desmoplastic infantile ganglioglioma.

Brain↗
PubMed1993

Dystrophic axonal formation (spheroid body) in central neurocytoma--case report.

A 30-year-old female presented with a central neurocytoma manifesting as positional headache. Magnetic resonance imaging showed a large calcified mass in the right lateral ventricle. The tumor was completely removed surgically. Light microscopy showed a linear arrangement of well-defined cells (beaded-string pattern) containing small round nuclei with abundant perikarya. A perinuclear halo reminiscent of oligodendroglioma was prominent in some cell groups. The tumor was entirely amitotic and free of atypia. Large, plump spheroid bodies lacking nuclei but containing coarse brown pigments were present among the tumor cells. The tumor cells were immunoreactive to neuron-specific enolase and synaptophysin but not glial fibrillary acidic protein or neurofilament. The ultrastructure of the tumor cells included abundant spheroid bodies containing secretory granules around neurons, indicating a dystrophic or aborted process of neuronal differentiation rather than a completely-differentiated central neurocytoma.

Adult↗
PubMed1993

Relationship between serum levels of methylguanidine and glycemic control in IDDM children.

OBJECTIVE: To examine the serum levels of methylguanidine in IDDM children and compare them with markers for glycemic control. Reports have indicated that active oxygen, which damages various tissues, increases in diabetes mellitus. The increase of active oxygen is one of the risk factors for diabetic complications. The synthesis of methylguanidine, a metabolic product of guanidine, is mainly regulated by active oxygen. RESEARCH DESIGN AND METHODS: Forty-eight children with IDDM (mean age 13.3 yr) and 17 age-matched nondiabetic control subjects were studied. Diabetic children were divided into a well-controlled group (HbA1c < 8%, n = 24) and a poorly controlled group (HbA1c > 8%, n = 24). Serum concentrations of methylguanidine were measured by enzymatic assay. RESULTS: Levels of methylguanidine in the poorly controlled group (1.31 +/- 0.08 microM) were significantly higher than those in both the well-controlled group (0.85 +/- 0.08 microM) and the control group (0.59 +/- 0.11 microM), respectively (P < 0.01). Methylguanidine levels showed a positive correlation with the levels of HbA1c (P < 0.01) or fructosamine (P < 0.01). No significant correlations were noted between methylguanidine levels and age, sex, duration of diabetes, or insulin dose. CONCLUSIONS: Our data indicate that the levels of methylguanidine in IDDM children might be affected by glycemic control and that the determination of serum methylguanidine levels could be a useful test for evaluating the state of diabetic control.

Biomarkers↗
PubMed1993

Latent herpes simplex virus type 1 in human vestibular ganglia.

Viral infection has been considered to be a possible pathogenesis of vestibular neuronitis, and reactivation of the herpes simplex virus (HSV) is one of the most likely causes. However, it remains unknown whether the human vestibular ganglia contain latent HSV. We examined 26 vestibular ganglia from autopsied adults in search of HSV type 1 (HSV-1). To detect HSV-1, we used polymerase chain reaction (PCR), in situ hybridization and immunohistochemical staining. HSV DNA was detected in 6 of 10 vestibular ganglia using the PCR method. However, the latency-associated transcript (LAT) of HSV-1 was negative in all of the 16 vestibular ganglia examined. No HSV antigen was detected in any of the ganglia. These results indicate that HSV-1 is latently infected in the human vestibular ganglia, and that LAT is transcribed weakly or not at all.

Adult↗
PubMed1993

Urinary laminin P1 as an index of glycemic control in children with insulin-dependent diabetes mellitus.

OBJECTIVE: To evaluate the clinical meanings of urinary laminin P1, urinary laminin P1 concentrations in children with insulin-dependent diabetes mellitus (IDDM) were measured and compared with urinary levels of albumin, kappa light chain (kappa-LC), alpha 1-microglobulin (alpha 1-MG), beta 2-microglobulin (beta 2-MG), and n-acetyl-b-D-glucosaminidase (NAG). RESEARCH DESIGN AND METHODS: Forty-six children with IDDM and 31 age-matched controls were studied. The first urine in the morning was collected for three days and stored at -20 degrees C until assayed. The mean values were used for the study. Radioimmunoassay (RIA) was used to measure of laminin P1, kappa-LC, alpha 1-MG, and beta 2-MG. NAG and haemoglobin Aic (HbA1c) concentrations were measured by a colorimetric method and high-performance liquid chromatography, respectively. RESULTS: Urinary laminin P1 levels in IDDM were 54.2 + 3.4 (SE) mU/microM.Cr, significantly higher than those in control subjects (40.7 +/- 2.3 mU/microM.Cr, p < 0.01). In 10 out of 46 patients (21.7 percent), the values were higher than the mean +/- 2 SD of controls. Urinary albumin, kappa-LC, alpha 1-MG, beta 2-MG, and NAG in IDDM were higher than those in control subjects (p < 0.01). There were significant correlations between urinary laminin P1 levels and urinary albumin, kappa-LC, NAG, alpha 1-MG, and beta 2-MG. A significant correlation was also shown between urinary laminin P1 and HbA1c concentrations (p < 0.01). CONCLUSIONS: From the above results, we conclude that urinary laminin P1 concentrations could be one of the clinical indexes for glycemic control and damage of the glomerulus in IDDM.

Acetylglucosaminidase↗
PubMed1993

[Hemodynamics and respiratory function in heart failure].

We discussed the pathophysiology of left-sided heart failure with special reference to the pulmonary "venous" system and further discussed the relationship between the capacitance of the pulmonary "venous" system and the pulmonary function. The slope of the pressure-volume line (compliance) in the pulmonary "venous" system was flat in NYHA class II and III patients as compared to class I. Elevated pulmonary "venous" pressure leads to a decrease in the compliance of the pulmonary "venous" system and consequently to a decrease in the static pulmonary compliance and this causes a respiratory dysfunction and an increase in the ventilation-perfusion imbalance. These changes may finally lead to an increase in the work of breathing, resulting in clinical symptoms such as dyspnea.

Heart Failure↗
PubMed1993

[Intermittent hepatic arterial infusion of high-dose 5-FU for liver metastases from colorectal cancer].

A phase II study of weekly intermittent hepatic arterial infusion of high dose 5-FU for liver metastases from colorectal cancer was carried out. Thirty-two patients with unresectable liver metastases from colorectal cancer were entered in this study. Nausea (< or = grade 2) was observed in 31% of the cases, mild elevation of rGTP in 13%, biloma in 9%, and hepatic arterial occlusion in 22%. However, no major toxicity occurred. The response rate evaluated by CT-scans was 75% (4 CR + 20 PR/32), and the overall median survival was 22 months. Significant differences of median survival were observed in the extra-hepatic lesions [extrahepatic lesions: (-) 16 months vs (+) 22 months]. This regimen showed high activity without major toxicity and the reduction of pts' QOLs caused by pumps. It confirmed by a study involving a large number of cases, this regimen will become a standard regimen for unresectable liver metastases from colorectal cancer.

Colorectal Neoplasms↗
PubMed1993

[The influence of pulmonary "venous" compliance on the static pulmonary compliance: a study of patients with left-sided heart disease with normal respiratory function].

In heart diseases, such as mitral stenosis and angina pectoris, the static pulmonary compliance has been reported to be decreased. By definition, the pulmonary "venous" system consists of the pulmonary veins and the left atrium. It plays an important role as the reservoir for the left ventricle. In this laboratory, the pulmonary "venous" compliance (Cp"v") has been evaluated as delta V/delta P of a short segment of the P"V" volume-pressure curve. To evaluate the influence of Cp"v" on the static pulmonary compliance and to speculate about the mechanisms of the reduction in static pulmonary compliance in left-sided heart disease, hemodynamic data and static pulmonary compliance (Cst) were measured in 27 patients with left-sided heart disease. Cst was measured with esophageal balloon technique in a sitting position. The static volume-pressure curve was fitted by a sigmoid model: V = Vm/(1 + e(A-P)/kappa), where kappa is a shape constant and an index of the lung stiffness. The pulmonary blood volume (PBV) was estimated with our own method, using radionuclide (RN) angiocardiography. The mean pulmonary artery wedge pressures (PAW) were measured using a floating catheter. Cp"v" was calculated as the delta V/delta P from the increment of pulmonary "venous" volume (delta V) and that of PAW (delta P) that occurred during passive elevation of the legs. Pulmonary arterial compliance (Cpa) was obtained from an analysis of the diastolic decline in pulmonary arterial pressure wave forms.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗