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Biomedical subjects

N Shimizu

Publications and source records attributed to N Shimizu.

At least 307 records · Page 17Linked to original sources
PubMed1999

Ex vivo delivery of suicide genes into melanoma cells using epidermal growth factor receptor-specific Fab immunogene.

The Fab fragment of monoclonal antibody B4G7 against human epidermal growth factor (EGF) receptor was conjugated with cationic poly-L-lysine and the resulting conjugate was further complexed with reporter genes or therapeutic genes. This Fab/DNA complex was designated as "Fab immunogene." The Fab immunogene transfer in vitro was mediated through the EGF receptors in two melanoma cell lines. The frequency of cells expressing beta-galactosidase (beta-Gal) reporter gene was approximately 1%. The induction of suicide effects after Fab immunogene transfer of herpes simplex virus thymidine kinase (TK) or Escherichia coli cytosine deaminase (CD) gene was quite remarkable, and the growth of melanoma cells was inhibited for over 7 days in the presence of ganciclovir (GCV) or 5-fluorocytosine (5-FC). Similarly, when melanoma cells treated in vitro with the Fab immunogene carrying TK or CD were transplanted into the back of nude mouse, subsequent systemic administration of GCV or 5-FC effectively suppressed the growth of tumors, indicating the occurrence of in vivo suicide effects.

Animals↗
PubMed1999

Epstein-Barr virus infection of the colon with inflammatory bowel disease.

OBJECTIVE: Epstein-Barr virus (EBV)-infected cells can evoke severe host immune responses, as shown in infectious mononucleosis and EBV-associated gastric carcinoma. To investigate the possible pathological role of EBV in inflammatory bowel disease (IBD), we tested for the presence of EBV in the colon in IBD patients. METHODS: Surgically resected colonic specimens of 11 patients with Crohn's disease, five patients with ulcerative colitis, nine noninflammatory controls (disease-free area of the colorectal carcinoma), and 10 appendicitis cases were tested using highly sensitive in situ hybridization for EBV-encoded small RNA1 (EBER-1). RESULTS: EBER-1 was detected in 63.6% of Crohn's disease cases and 60% of ulcerative colitis cases, but not at all in noninflammatory controls and appendicitis cases. EBER-1-positive cells were very rare in the noninflammatory areas of colonic specimens from IBD patients. EBER-1-positive cells were nonepithelial cells (mainly B lymphocytes and a few histiocyte-shaped cells) located in erosive or ulcerative areas of the colonic specimens. CONCLUSION: The limited presence of EBV-infected cells in the diseased areas of IBD colonic specimens indicated that EBV infection may be related to such diseases.

Adult↗
PubMed1999

Decreased urinary concentrations of type IV collagen in amyotrophic lateral sclerosis.

OBJECTIVES: Type IV collagen (IV-C) abnormalities of skin and serum have been reported in patients with amyotrophic lateral sclerosis (ALS). However, there has been no study of urinary IV-C in ALS. The present study investigates urinary IV-C and the relation to its skin content in patients with ALS. MATERIAL AND METHODS: We studied IV-C immunoreactivity of skin and measured urinary levels of IV-C in ALS patients and controls. RESULTS: The basement membrane as well as blood vessels of skin in ALS patients was weakly positive for IV-C as compared with those of controls. Immunostaining became even weaker as ALS progressed. The urinary level of IV-C in ALS patients was significantly decreased as compared to diseased controls (P<0.001) and healthy controls (P<0.001), and was negatively and significantly associated with duration of symptoms (r=-0.85, P<0.001). There was an appreciable positive correlation between urinary IV-C levels and the density for IV-C immunoreactivity in ALS patients (r=0.84, P<0.01). CONCLUSION: These data suggest that a metabolic alteration of IV-C may occur in ALS patients and decreased levels of urinary IV-C may be related to the decreased IV-C immunoreactivity of skin in ALS.

Aged↗
PubMed1999

Increased type III procollagen in serum and skin of patients with amyotrophic lateral sclerosis.

OBJECTIVES: Collagen abnormalities of skin have been reported in patients with amyotrophic lateral sclerosis (ALS). However, little is known concerning the aminoterminal propeptide of type III procollagen (PIIIP) and type III collagen in ALS. The aim of this study is to measure PIIIP, a precursor form of type III collagen, in skin and serum of ALS. MATERIAL AND METHODS: We studied PIIIP immunoreactivity of skin and measured serum levels of PIIIP in ALS patients, and the results were compared with those of control subjects. RESULTS: Collagen bundles in the dermis of ALS were immunohistochemically strongly positive for PIIIP as compared with those of controls. The optical density of PIIIP immunostaining reactivity in ALS patients was significantly higher than in controls, and was significantly increased with duration of illness. Serum PIIIP levels in patients with ALS were significantly increased as compared with those in diseased control subjects and those in healthy control ones, and were positively and significantly associated with duration of illness. There was an appreciable positive correlation between concentrations of serum PIIIP and the density of PIIIP immunoreactivity of skin in ALS patients. CONCLUSION: These data suggest that a metabolic alteration of PIIIP may take place in the skin of ALS and the increased levels of serum PIIIP may reflect the increased PIIIP immunoreactivity of skin in ALS.

Activities of Daily Living↗
PubMed1999

An orphan G protein-coupled receptor, GPR1, acts as a coreceptor to allow replication of human immunodeficiency virus types 1 and 2 in brain-derived cells.

Twelve G protein-coupled receptors, including chemokine receptors, act as coreceptors and determinants for the cell tropisms of human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). We isolated HIV-1 variants from T-cell-line (T)- and macrophage (M)-tropic (i.e., dualtropic) (R5-R3-X4) HIV-1 strains and also produced six HIV-1 mutants carrying single-point amino acid substitutions at the tip of the V3 region of the Env protein of HIV-1. These variants and three mutants infected brain-derived CD4-positive cells that are resistant to M-, T-, or dualtropic (R5, X4, or R5-X4) HIV-1 strains. However, a factor that determines this cell tropism has not been identified. This study shows that primary brain-derived fibroblast-like cell strains, BT-3 and BT-20/N, as well as a CD4-transduced glioma cell line, U87/CD4, which were susceptible to these HIV-1 variants and mutants and the HIV-2ROD strain, expressed mRNA of an orphan G protein-coupled receptor (GPCR), GPR1. When a CD4-positive cell line which was strictly resistant to infection with diverse HIV-1 and HIV-2 strains was transduced with GPR1, the cell line became susceptible to these HIV-1 variants and mutants and to an HIV-2 strain but not to T- or dualtropic HIV-1 strains, and numerous syncytia formed after infection. These results indicate that GPR1 functions as a coreceptor for the HIV-1 variants and mutants and for the HIV-2ROD strain in vitro.

Brain↗
PubMed1999

Decrease in the ciliary neurotrophic factor of the spinal cord in amyotrophic lateral sclerosis.

Ciliary neurotrophic factor (CNTF), a potent survival factor in spinal motoneurons of embryonic chick and rat, is currently being investigated in humans as a treatment for amyotrophic lateral sclerosis (ALS). However, its physiological and pathological activities in ALS remain unclear. We measured CNTF contents in the cervical enlargement of the spinal cord from 9 ALS patients and 12 age-matched control subjects using a sensitive enzyme-linked immunoassay. CNTF genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism method. In control subjects, there were 8 homozygotes and 4 heterozygotes, while in ALS patients there were 6 and 3, respectively. In both homozygotes and heterozygotes, CNTF expression in the spinal cord from ALS patients tended to decrease compared to control subjects. In homozygotes, the decrease was significant (p < 0.05). Concerning the regional concentrations of CNTF, in homozygotes, CNTF contents in the lateral corticospinal tract were markedly lower (p < 0.001) in ALS patients than in controls. The decrease in CNTF expression in the lateral corticospinal tract of the spinal cord from ALS patients may be a feature of ALS and could be related to motor neuron loss.

Amyotrophic Lateral Sclerosis↗
PubMed1999

Structure and chromosome mapping of the human SIX4 and murine Six4 genes.

Six4, a member of the homeobox gene subfamily (Six), is expressed in a developmentally regulated fashion, and supposed to be involved in embryogenesis. We cloned the human SIX4 and murine Six4 genomic DNAs and determined their structures. The structure, including the 5' upstream region of both genes, was well conserved suggesting the conserved function and regulation of these genes. Human SIX4 was mapped to chromosome 14q23.

Amino Acid Sequence↗
PubMed1999

Threshold concentration of unbound bilirubin to induce neurological deficits in a patient with type I Crigler-Najjar syndrome.

Based on the clinical course of a 16-year-old boy with type I Crigler-Najjar syndrome, we estimated the threshold concentration of unbound bilirubin, as assayed by the horseradish peroxidase method, that apparently induces toxicity to the brain. Before the age of 15, the patient did not manifest any neurological or behavioural dysfunction despite increased bilirubin in serum. The binding affinity and the binding capacity of the patient's serum albumin for bilirubin determined when he was about 14 years old were 10(8)(mol/L)-1 and 1.01 to 1.04 mol/L, respectively. These values were nearly the same as those of normal controls reported in the literature. The total bilirubin binding capacity was greater than the patient's total bilirubin concentration, showing that his serum albumin was not saturated with bilirubin. The reserve bilirubin binding capacity (RBBC) was estimated to be 158 mumol/L and the unbound bilirubin concentration to be 15.1 nmol/L. Concentration of unbound bilirubin peaked at 21.7 nmol/L at the age of 15 years and 11 months, i.e. 2 months before the onset of difficulties in walking and speaking. At this time, the RBBC was estimated as -64 mumol/L. A peak concentration of total bilirubin, 811 mumol/L, was observed during the period of rapid loss of the ability to walk or speak. At the age of 16 years and 1 month the RBBC decreased to -98 mumol/L and the unbound bilirubin concentration to 18.8 nmol/L. Following phototherapy, the patient's neurological state returned to normal; he could speak and walk normally. At the age of 16 years and 2 months the RBBC returned to 105 mumol/L and unbound bilirubin decreased to 16.6 nmol/L. These results suggest that maintaining the concentration of unbound bilirubin at < 20 nmol/L and the total bilirubin concentration at lower than the binding capacity of serum albumin is important for prevention of neurological deficits in Crigler-Najjar syndrome. The upper limit of unbound bilirubin in such an older patient was nearly the same as that reported for newborns.

Adolescent↗
PubMed1999

Pituitary somatotroph adenoma producing growth hormone (GH)-releasing hormone (GHRH) with an elevated plasma GHRH concentration: a model case for autocrine and paracrine regulation of GH secretion by GHRH.

An acromegalic patient with a pituitary somatotroph adenoma associated with an extremely elevated plasma GHRH concentration is presented. The preoperatively high concentration of plasma GHRH returned to the normal level after successful removal of the adenoma. GHRH production and GHRH gene expression were confirmed in the adenoma by studies including immunohistochemistry and in situ hybridization. Expression of GHRH receptor messenger ribonucleic acid was verified by in situ hybridization. Immunohistochemical double staining for GH and GHRH revealed their colocalization in single adenoma cells. These findings confirmed the autocrine or paracrine regulation of GH production by endogenous GHRH from the adenoma cells. GHRH synthesis in the pituitary gland has recently been demonstrated, however, there have been no previous reports of a GHRH-producing pituitary somatotroph adenoma associated with an elevated plasma GHRH concentration. The existence of this GHRH-producing adenoma suggests a possible role of locally generated GHRH in the progression of somatotroph adenomas, i.e. the monoclonally established somatotroph adenomas develop further under the influence of locally produced GHRH. The demonstration of GHRH production by this somatotroph adenoma is of importance in clarifying the autocrine or paracrine regulation of GH production and the progression of human somatotroph adenomas.

Acromegaly↗
PubMed1999

Kinetics of pulmonary gas exchange during and while recovering from exercise in patients after anterior myocardial infarction.

The effect of exercise intensity on gas exchange kinetics was investigated during exercise and recovery, as well as the relationship between the kinetics during exercise and recovery. Twenty-three patients with a history of anterior myocardial infarction performed low-intensity (38.7+/-8.3 W) and high-intensity (68.8+/-15.0 W) exercise for 6 min. The time constants of oxygen uptake (VO2), carbon dioxide output (VCO2) and minute ventilation (VE) were significantly prolonged during high intensity exercise compared with low-intensity exercise (61.2+/-8.6 vs 52.3+/-10.3 s, p<0.005 for the time constant of VO2). The time constant of VO2 was similar during exercise and during recovery from exercise of high (61.2+/-8.6 vs 66.2+/-12.2 s) as well as low intensity (52.3+/-10.3 vs 55.0+/-10.1 s). However, the time constants of VCO2 and heart rate were significantly shorter during recovery than during exercise. The time constants of VCO2 and VE were significantly longer than that of VO2 during both exercise and recovery. In the present study, it was found that (1) the gas exchange kinetics were influenced by the intensity of exercise; (2) the kinetics during recovery did not necessarily reflect the kinetics during exercise except for VO2; and (3) the kinetics of VCO2 and VE were delayed as compared with the VO2 kinetics. These characteristics should be taken into account when using gas exchange kinetics to estimate cardiopulmonary responses to exercise in patients with left ventricular dysfunction.

Adult↗
PubMed1999

Contribution of glutamate receptors to benzodiazepine withdrawal signs.

Recent research has demonstrated that the receptor for glutamate, a major excitatory neurotransmitter, may play an important role in the expression of benzodiazepine withdrawal signs. This proposal is based on various observations. For example, antagonists for N-methyl-D-aspartate (NMDA), non-NMDA and metabotropic glutamate (mGlu) receptors can suppress the behavioral signs of benzodiazepine withdrawal in mice and rats. Furthermore, the NMDA receptor in the cerebrocortical area of diazepam-withdrawn rats is upregulated. Finally, the stimulation of phosphoinositide hydrolysis mediated by mGluR is enhanced in cerebrocortical slices from lorazepam-withdrawn mice. These findings show that the upregulation of signal transduction mediated by glutamate receptors during diazepam withdrawal plays a role in the neuroadaptive response responsible for the expression of diazepam withdrawal signs. Furthermore, ligands for glutamate receptors may be suitable targets for treating benzodiazepine withdrawal signs.

Animals↗
PubMed1999

Distribution of JC virus DNA in peripheral blood lymphocytes of hematological disease cases.

OBJECTIVE: The distribution of JC virus DNA in peripheral blood was surveyed by the polymerase chain reaction using the late genes as markers. RESULTS: Six out of 52 cases of hematological diseases and one systemic lupus erythematosus case out of 17 cases were positive for JCV DNA. After separation into B and T lymphocytes by a cell sorter, JCV DNA was found in both cell types prepared from adult T cell leukemia and PML patients. CONCLUSION: Only 1 or 2 copies of JCV genome were calculated to exist in a cell based on the time course analysis of PCR. Only B lymphocytes and glial brain cells are known to produce nuclear factors which support the growth of the virus. The result that B lymphocytes contained a copy number of JCV genome similar to T lymphocytes suggests that there is some barrier to viral growth in susceptible B lymphocytes, and that the growth of JCV is different from that of other virulent viruses.

Aged↗
PubMed1999

A case of thoracoscopic bilateral lung volume reduction surgery in a supine position.

We present a case of thoracoscopic bilateral lung volume reduction surgery performed with the patient in a supine position. By rotating the operative table, bilateral apical resection could be performed without difficulty. The duration of the operation was 160 minutes and the patient's forced expiratory volume in 1 second improved from 0.81 l to 2.49 l.

Endoscopy↗
PubMed1999

[Accuracy, precision and clinically acceptable level of complete blood cell count by an automated multichannel hematology analyzer].

Measurement of complete blood cell count (CBC) is one of the essential laboratory tests. In this study, the accuracy of CBC was high, when measured by six different automated blood cell counters, including SE-9000/RAM-1, CELL-DYN 4000, ADVIA 120, VEGA RETIC-LC141 or GEN*S. The correlations of CBC counts among these instruments were also good. In contrast, the accuracy in abnormal samples depended on matching the instrument and type of clinical conditions. Internal quality control of automated multichannel hematology analyzers was recommended by the NCCLS H26-A in 1996. However, actual external quality control of the CBC count was poorly understood. We surveyed three samples from healthy volunteers for CBC values in 1997. Among six different instruments, the inter-assay of the red blood cell count (RBC), hemoglobin, hematocrit and MCV was fairly good, shown as < 4.2%, < 3.0%, < 4.4% and < 3.4%, respectively. In contrast, the inter-assay of the white blood cell count (WBC) and platelet (PLT) was not good, shown as < 11.4% and < 9.6%, respectively. The clinically acceptable levels for the blood cell count were reported to be 4% for RBC, 3% for hemoglobin, 4% for MCV, 5% for WBC and 7% for PLT, by JCCLS in 1994. The clinically acceptable CBC by hematologists at Keio University resembled those by councilors of The Japanese Society of Clinical Hematology, whereas, residents at Keio University and general physicians required more precise clinical CBC counts. These results indicate that a larger study is needed to clarify the accuracy, clinically acceptable level, and performance of different automated blood cell counters.

Blood Cell Count↗
PubMed1999

[A case of myotonic dystrophy showing proximal dominant muscle involvement but not myotonia].

A 45-year-old female had progressive difficulty in climbing stairs and standing from a chair for 10 years. She had binocular cataracts which were operated at the age of 42 years. On examination, she had marked muscle wasting in the proximal limbs, scapular and sternomastoid muscles. She presented as marked muscle weakness in the proximal portion of the lower extremities and moderate in the upper extremities and the legs. Deep tendon reflexes were absent in all limbs. There was no grip myotonia, or percussion myotonia of the thenar muscle and tongue. Myotonia was not elucidated even after the hands were exposed to cold water. Moreover, none of the examined muscles revealed insertion myotonic discharge on electromyography. Serum CK level was normal and IgG value decreased to 546 mg/dl. Muscle biopsy of the left biceps muscle showed the variation in fiber size, increased central nuclei and many fiber with pyknotic nuclear clumps on HE staining. Sarcoplasmic mass and ring fibers were also found on HE staining. There were a few percents of ragged-red fibers on Gomori-trichrome staining, and type 1 fiber atrophy was found on pH 4.5 ATP-ase staining. The expansion of lymphocyte CTG trinucleotide repeats in the myotonin protein kinase gene was about 733, so that she was diagnosed as having myotonic dystrophy (MD). MRI of skeletal muscles exhibited marked atrophy especially in the femoral region and the biceps muscle. This patient had the proximal dominant muscle weakness, and absent myotonia even on electromyographic examination, which are unusual clinical features of adult onset MD.

Atrophy↗
PubMed1999

[Thymic enlargement exhibiting remarkable respiration-induced changes in form].

The patient was a 30-year-old woman. During an examination for a painful bruise on her back, an anterior mediastinal mass lesion was detected by computed tomographic (CT) scan. A second CT scan 6 days later showed pronounced expansion of the anterior mediastinal mass shadow. A third CT scan performed 18 days later, however, disclosed that the mass had contracted back to the size observed with the initial CT scan. Respiration-induced changes in size were suspected, and breathing dynamic cine magnetic resonance imaging (MRI) was performed. The MRI findings clearly demonstrated that the anterior mediastinal mass shadow contracted on inspiration and expanded on expiration. The patient was admitted for suspected thymoma, and hyperthyroidism was diagnosed. After her thyroid function normalized, a subtotal thyroidectomy and thymectomy were simultaneously performed. The pathologic diagnosis was thymus enlargement and hyperthyroidism, respectively. Breathing dynamic cine MRI provided extremely valuable films that demonstrated remarkable respiration-induced changes in the shape of the enlarged thymus.

Adult↗