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Biomedical subjects

H Hojo

Publications and source records attributed to H Hojo.

At least 37 records · Page 2Linked to original sources
PubMed2001

Absence of somatic hypermutation of immunoglobulin heavy chain variable region genes in precursor B-lymphoblastic lymphoma: a study of four cases in childhood and adolescence.

Somatic mutation (SM) analysis provides a useful tool for understanding the suitable stage of differentiation of normal and neoplastic B cells. B-cell precursor neoplasms are considered to be somatically premutational. However, no reports have been made on the sequence analysis of SM in rearranged immunoglobulin heavy chain variable region (VH) genes in precursor B-lymphoblastic lymphoma (PB-LBL); as for B-cell acute lymphoblastic leukemia (B-ALL), the variable frequency of SM of the VH genes has been described. To better distinguish PB-LBL from B-ALL based on the stage at which differentiation occurs, we analyzed the SM of the VH genes in 4 children and adolescents with PB-LBL. In all 4 cases, there was no SM in complementarity-determining regions 1, 2, and 3 and in framework regions 2 and 3 of the VH genes, except for 1 mutation in 1 of 2 polymerase chain reaction products from 1 patient. Our data showed the absence of SM of lymphoma cells in PB-LBL, in addition to the developmentally regulated rearrangement of VH genes at the stage of B-cell precursor cells. The lack of mutation in VH gene sequences suggests that SM may differ between PB-LBL and B-ALL.

Adolescent↗
PubMed2001

Abnormalities of gonadotrophs in the adenohypophysis of infertile male PD rats.

Male PD strain rats are sterile in the homozygous condition (pd/pd) due to abnormal spermatogenesis detectable at around nine weeks of age. Previous studies have indicated electron microscopic abnormalities in the Sertoli cells of pd/pd males at three and 12 weeks of age. Since spermatogenesis and Sertoli cell function depend on gonadotropins (luteinizing and follicle-stimulating hormones [LH and FSH]) and testosterone, production and/or secretion of these hormones might be altered in pd/pd males. The aim of the study reported here was to investigate the hormonal status of pd/pd males at three, six, and nine weeks of age. Although alteration was not evident in the LH-immunoreactive cells, FSH-immunoreactive cells in pd/pd males were small in size with scant cytoplasm and were reduced in number and area (73 and 51% of phenotypically normal pd/+ males, respectively) at three weeks of age, although serum FSH concentration was similar to that in pd/+ males. At six and nine weeks of age, percentages of the areas occupied by LH- and FSH-immunoreactive cells in pd/pd males were higher than those in pd/+ males. Serum FSH concentration in pd/pd males was significantly high at nine weeks of age, although a difference in serum LH and testosterone concentration was not evident. These results suggest that FSH production in pd/pd males is decreased at three weeks of age. This might be associated with the Sertoli cell abnormalities and subsequent abnormal spermatogenesis seen in adult life.

Animals↗
PubMed2000

Oozing type cardiac rupture repaired with percutaneous injection of fibrin-glue into the pericardial space: case report.

Two patients, a 56-year-old man and an 81-year-old woman who were admitted to hospital because of anteroseptal acute myocardial infarction, were initially treated successfully with direct percutaneous transluminal coronary angioplasty. However, both patients later developed sudden cardiogenic shock due to cardiac tamponade caused by left ventricular free wall rupture (LVFWR). Prompt, life-saving pericardiocentesis was performed, then fibrin-glue was percutaneously injected into the pericardial space. After the procedure, there was no detectable pericardial effusion on echocardiography and the hemodynamic state became stable. The surgical treatment was the standard procedure for LVFWR, but percutaneous fibrin-glue therapy can also be considered for oozing type LVFWR.

Aged↗
PubMed2000

Studies on the 1,1-diphenyl-2-picrylhydrazyl radical scavenging mechanism for a 2-pyrone compound.

The radical scavenging mechanisms for the 2-pyrone compound, 4-hydroxy-3,6-dimethyl-2H-pyrane-2-one (1), and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (4) in several solvent systems were evaluated by the quantitative change in compounds detected at 270 nm and subsequent HPLC analyses. The HPLC profile for each condition suggested that the reaction proceeded by a different mechanism in each solvent system. In organic solvents (CHCl3, iso-propanol, and EtOH), 1-[4-(3,4-dihydro-3,6-dimethyl-2,4-dioxo-2H-pyran-3-yl) phenyl]-1-phenyl-2-picrylhydrazine (2) was produced as an adduct of the DPPH radical and 1. On the other hand, the reaction in a buffer solution (an acetate buffer at pH 5.5) gave several degradation products with 1[4-(2,3-dihydro-2,5-dimethyl-3-oxo-fur-2-yl) phenyl]-1-phenyl-2-picrylhydrazine (5), this being structurally elucidated by spectroscopic analyses. The decrease of the DPPH radical in each reaction system suggests that compound 1 could scavenge about 1.5-1.8 equivalents of the radical in organic solvents and about 3.5-3.9 in the buffer solution.

Bepridil↗
PubMed2000

Recent progress in the solid-phase synthesis of glycopeptide.

The recent understanding of the biological role of glycoproteins has brought about a demand for the highly homogeneous glycopeptides as the functional model for glycoproteins. Thus, much efforts have been made to establish easy and efficient method for glycopeptide synthesis. In this paper, we briefly review the recent advances in the synthesis of O- and N-linked glycopeptide based on the solid-phase method. In O-glycopeptide section, the preparation of glycosylated amino acid units with mucin type and other O-linked carbohydrate chains and their use for solid-phase synthesis are summarized. Other approaches, such as the glycosylation of resin bound peptide are also overviewed. In N-glycopeptide section, the synthesis using glycosylated amino acid units as well as other methods are described.

Amino Acid Sequence↗
PubMed1999

Induction of human beta-defensin-2 mRNA expression by Helicobacter pylori in human gastric cell line MKN45 cells on cag pathogenicity island.

Helicobacter pylori is an etiological agent of gastritis, peptic ulcer, and gastric cancer. Human beta-defensin-2 (hBD-2) is an antimicrobial peptide which belongs to one of the most important host defense systems against bacterial infection in several epithelial tissues. We studied the effect of H. pylori on the expression of hBD-2 mRNA in MKN45 gastric mucosal cells. H. pylori, but not culture filtrate, increased the hBD-2 mRNA level in MKN45 cells; the inductive effect of H. pylori was not detected with Intestine 407 cells. Among H. pylori strains, strain OHPC0002, which lacks a cag Pathogenicity Island (PAI), did not induce hBD-2 mRNA in MKN45 cells. These results suggested that H. pylori cag PAI is critical for the induction of hBD-2 mRNA in MKN45 cells. Exposure of MKN45 cells to Salmonella typhimurium, S. enteritidis, S. typhi, and S. dublin, but not Escherichia coli ML35, also resulted in induction of hBD-2 mRNA.

Blood Bactericidal Activity↗
PubMed1999

Acetylleucine chloromethyl ketone, an inhibitor of acylpeptide hydrolase, induces apoptosis of U937 cells.

Acetylleucine chloromethyl ketone (ALCK), an inhibitor of acylpeptide hydrolase (ACPH), inhibited the growth of human monoblastic U937 cells in a dose- and time-dependent manner. Morphology of the ALCK-exposed cells showed typical apoptosis, judging from the nuclear condensation and segmentation. Chromosomal DNA of U937 cells treated with ALCK showed an internucleosomal ladder-like pattern on electrophoresis, being characteristic of apoptosis. Of the other leucine chloromethyl ketone analogues, butyloylleucine chloromethyl ketone (BLCK) induced a weak ladder-like formation but caploylleucine chloromethyl ketone (CLCK)barely did. On the other hand, intracellular ACPH activity of U937 cells was strongly inhibited by culturing with ALCK, moderately with BLCK, and not with CLCK. These findings indicate that the inhibition of ACPH activity leads to apoptosis and suggest that ACPH may play a vital role in eukaryotic cells.

Amino Acid Chloromethyl Ketones↗
PubMed1999

Analysis of the immunoglobulin heavy chain gene variable region of 101 cases with peripheral B cell neoplasms and B cell chronic lymphocytic leukemia in the japanese population.

We have analyzed the immunoglobulin heavy chain (VH) gene variable regions (CDR2 and FW3) of 101 Japanese cases with peripheral B cell neoplasms. When all except one case with a deletion were graphed by frequency of replacement mutation, the 100 cases could be separated into two groups: 24 cases with zero, one and two mutations (germline or low frequency of somatic mutation); and 76 cases with three or more mutations (medium to high frequency of somatic mutation). While most mantle cell lymphoma cases (11/13) showed germline or low frequency of somatic mutation, all cases of mucosa-associated lymphoid tissue (MALT) lymphoma (11/11), follicular lymphoma (three of three cases), plasma cell myeloma (seven of seven cases) and most cases of diffuse large B cell lymphoma (DLBCL; 42/47) belonged to the latter group. These 76 cases, therefore, may be considered to show somatic hypermutation. More than half of chronic lymphocytic leukemia/small lymphocytic lymphoma cases (CLL/SLL; eight of 13) showed a hypermutated VH gene and the ratio of replacement mutation: silent mutation in CDR2 of CLL/SLL was considerably higher compared with DLBCL and MALT lymphoma, showing somatic hypermutation. When comparing VH gene type of B cell-CLL (B-CLL) among our series and those in the literature, more cases of CD5+ B-CLL in the Western literature have the VH5 and VH6 family types, while more cases in Japan are reported to have VH4 family. The occurrence of VH families in B-CLL between Japanese and Western people seems to be comparable.

Aged↗
PubMed1999

A mini-protein designed by removing a module from barnase: molecular modeling and NMR measurements of the conformation.

A globular domain can be decomposed into compact modules consisting of contiguous 10-30 amino acid residues. The correlation between modules and exons observed in different proteins suggests that each module was encoded by an ancestral exon and that modules were combined into globular domains by exon fusion. Barnase is a single domain RNase consisting of 110 amino acid residues and was decomposed into six modules. We designed a mini-protein by removing the second module, M2, from barnase in order to gain an insight into the structural and functional roles of the module. In the molecular modeling of the mini-protein, we evaluated thermodynamic stability and aqueous solubility together with mechanical stability of the model. We chemically synthesized a mini-barnase with (15)N-labeling at 10 residues, whose corresponding residues in barnase are all found in the region around the hydrophobic core. Circular dichroism and NMR measurements revealed that mini-barnase takes a non-random specific conformation that has a similar hydrophobic core structure to that of barnase. This result, that a module could be deleted without altering the structure of core region of barnase, supports the view that modules act as the building blocks of protein design.

Bacterial Proteins↗
PubMed1998

Oral teratogenicity studies of methyl bromide in rats and rabbits.

Teratogenicity studies of methyl bromide, a widely used fumigant, were conducted in rats and rabbits. Methyl bromide was dissolved in corn oil and administered orally to groups of 24 copulated female Crj:CD (SD) rats at dose levels of 0 (corn oil), 3, 10 or 30 mg/kg/day on days 6-15 of gestation and to groups of 18 artificially inseminated female Kbl:JW rabbits at 0, 1, 3 or 10 mg/kg/day on days 6-18 of gestation. Maternal rats and rabbits were euthanized on respective days 20 and 27 of gestation. Foetuses were examined for survival, growth and teratological alterations. Maternal toxicity was evident in the high-dose groups for both species. In these groups, maternal body weight gains and food consumption were significantly decreased during the dosing and post-dosing periods. Necropsy of maternal rats also revealed erosive lesions in the stomach and the surrounding organs. However, no treatment-related adverse effects were found in foetuses of the treated groups for both rat and rabbit studies. These results led to the conclusion that methyl bromide was not foetotoxic or teratogenic to rat and rabbit foetuses up to dose levels of 30 and 10 mg/kg/day, respectively, at which maternal toxicity was evident for both species.

Abnormalities, Drug-Induced↗
PubMed1998

Endoscopic harvest of saphenous vein graft for coronary artery bypass grafting: Saitama-Olympus technique.

OBJECTIVE: This study was undertaken to examine the clinical feasibility of a newly developed video-assisted endoscopic technique (Saitama-Olympus technique) to harvest saphenous vein graft (SVG) in 40 CABG patients. METHODS: There were 37 males and three females with an average age of 59+/-11 years. The special instruments developed were optical sheath, solid dilators, tunnel retractor, vessel dissector, GCC forceps which were utilized in conjunction with the thoracoscopic surgery system (Olympus, Tokyo, Japan). The course of the saphenous vein (SV) was marked on the skin prior to operation. SV was identified in the femoral region with a 4-cm skin incision and dissected with an open technique. The anterior surface of SV was dissected for 30 cm by the optical sheath mounted on the endoscope. Then another 4-cm skin incision above SV was placed in the popliteal region, resulting in a subcutaneous space over the SV. The subcutaneous space was then dilated and maintained with the tunnel retractor which has an endoscope channel at the top. With this system SV was visualized stably by endoscope without any assistance. All side branches were dissected and divided with the vessel dissector. When longer SVG is required, the same procedure was extended to the ankle with additional one or two skin incisions. RESULTS: SV was easily harvested in all patients with spending 15-84 min. The average number of skin incisions was 2.4+/-0.5 and the average length of the harvested SVG was 41+/-12 cm. The average number of bypassed grafts was 3.4+/-1.0 with use of left internal mammary artery (IMA) in 31 patients. The average operation time was 272+/-52 min, there were no significant prolongation relating to endoscopic SVG harvesting. The remainder of SVG in each patients was pathologically examined and there were no evidence of intimal injury. There were no major wound complications during the average follow-up of 10+/-4 months and this technique seemed to be advantageous for patients with less wound pain and better cosmetic appearance. CONCLUSIONS: The Saitama-Olympus technique to endoscopically harvest the SV is a clinically feasible surgical technique with the unique potential of a significant reduction in morbidity and decreased wound scarring in CABG patients.

Coronary Artery Bypass↗
PubMed1998

Electrophysiological study of myoclonus in pediatric practice.

Myoclonus can be caused from a variety of central nervous system disorders. With regard to its pathophysiology, much work has been done in adult patients, but reports from pediatric clinics are scarce. We describe the clinical and electrophysiological features of four different types of myoclonus in children using back averaging technique. In a patient with cortical reflex myoclonus, myoclonic jerks were induced in the distal right arm by taps on the ipsilateral fingers. Myoclonus was preceded by the cortical spike which was localized posterior to the central sulcus contralateral to the myoclonus, and the cortical spike was time-locked to the myoclonus. In a patient with subcortico-cortical myoclonus, myoclonus occurred as a focal motor seizure. Myoclonic jerks were preceded by generalized cortical waves which were of maximal amplitude over the cortex contralateral to the myoclonus, and cortical waves time-locked to the myoclonus. A patient with spinal myoclonus had rhythmical and segmental myoclonus. Myoclonus was induced in both arms after electrical stimulation at the wrist with a latency which was slightly longer than that of the F wave. In a patient with brainstem myoclonus, muscle activity was bilaterally synchronous and was predominant in the proximal flexors. The pattern of muscle recruitment suggested that the myoclonus signal travelled downward along the spinal cord and upward through the brainstem. The back averaging technique is essential in the differential diagnosis of myoclonus.

Adolescent↗
PubMed1997

Opsoclonus-myoclonus syndrome with abnormal single photon emission computed tomography imaging.

The single photon emission computed tomography (SPECT) findings in 2 patients with opsoclonus-myoclonus syndrome (OMS) who had similar symptoms in the acute stage of the disease are described. In 1 patient with encephalitis, SPECT showed increased blood flow in most of the cerebellum; the highest accumulation of the radiotracer was found in the cerebellar vermis and neighboring structures. These changes disappeared with clinical improvement. In the other patient with chronic OMS, SPECT demonstrated hypoperfusion in most of the cerebellum. Our results suggest that the cerebellum, particularly its middle portion, is involved in the generation of OMS. SPECt is a useful method that enables us to detect in vivo functional impairment in patients with OMS.

Female↗
PubMed1997

Electrographic study of brainstem reflex myoclonus.

A patient with post-hypoxic brainstem reflex myoclonus was examined. In spontaneous jerks electromyographic activity started in the sternocleidomastoid and spread down the spinal cord bilaterally. A similar jerk was elicited by somaesthetic or acoustic stimulation. The patient's blink reflex suggested bilateral pontine lesions at least. Thus, the pattern of muscle activation pointed to a brainstem origin of the myoclonus. Spinal conduction studies conducted during the jerks suggested that the myoclonus signal facilitated a path identical to the spinobulbospinal reflex demonstrated in animals.

Brain Stem↗
PubMed1997

Appearance of morphologically abnormal Sertoli cells in infertile PD male rats during postnatal development.

Our previous studies using 12-week-old PD (pd/pd) male rats have indicated high incidence of morphologically abnormal Sertoli cells. Because sterility in these males is attributable to abnormal spermatogenesis, it is suggested that the abnormal Sertoli cells are related to abnormal spermatogenesis. In this study, the testes of prepubertal 7- and 21-day-old male pd/pd rats were examined ultrastructurally for the presence of abnormal Sertoli cells. The pd/+ males served as controls. At 7 days of age, light and dark types of Sertoli cells were found in pd/pd males. However, no anatomic abnormality existed in those cells. Cytoplasmic organelles were underdeveloped. The only difference between the light and dark Sertoli cells was the high electron density in the nucleus and cytoplasm of the dark cells. These features were similar between pd/pd and pd/+ males. At 21 days of age, the dark Sertoli cells had disappeared, and light Sertoli cells and abnormal Sertoli cells were observed in pd/pd males. The light Sertoli cells had well-developed cytoplasmic organelles. On the other hand, abnormal Sertoli cells had a dark appearance, irregularly shaped nuclei, and a large quantity of lipid droplets in the cytoplasm. These findings suggested the presence of functional disorders in lipid metabolism. The light and abnormal Sertoli cells also were found in pd/+ males; however, incidence of the abnormal Sertoli cells was significantly higher in pd/pd males (11.3%), compared with that in pd/+ males (4.9%). Thus, these results indicate that in pd/pd male rats, a number of abnormal Sertoli cells appear by 21 days of age.

Animals↗
PubMed1996

Functional and possible physical association of scavenger receptor with cytoplasmic tyrosine kinase Lyn in monocytic THP-1-derived macrophages.

Acetyl LDL (modified low-density lipoprotein), which is thought to be taken up through scavenger receptor A (SR-A), rapidly induced the appearance of phosphotyrosine proteins in monocytic THP-1-derived macrophages in vitro. The two alternative forms of Lyn (p53 and p56) were found to be tyrosine-phosphorylated within 30 s after the stimulation with acetyl LDL. The catalytic activity of Lyn measured by an in vitro kinase assay had also increased in acetyl LDL-stimulated THP-1-derived macrophages. Furthermore, Lyn could be co-immunoprecipitated with SR-A from the cell lysate. These observations suggest a functional and possible physical association of SR-A with Lyn in THP-1-derived macrophages, and also imply a possible involvement of Lyn in SR-A signal transduction.

Amino Acid Sequence↗