Biomedical subjects

Masahiro Kikuchi

Publications and source records attributed to Masahiro Kikuchi.

At least 91 records · Page 5Linked to original sources

PubMed2002

Geometry of artificial ECM: sizes of pores controlling phenotype expression in BMP-induced osteogenesis and chondrogenesis.

This study aims to elucidate the feasible geometry of the scaffolds in bone and periodontal tissue engineering. Several biomaterials with different geometries are compared in terms of their patterns of ectopic BMP-induced chondrogenesis and osteogenesis. The materials include a honeycomb-shaped hydroxyapatite (HCHAP) with different tunnel sizes, a laser-perforated collagen membrane (LPM), and CPSA bioglass fibers. Implanted pellets were removed at 1-4 weeks and analyzed for bone and cartilage formation histologically and biochemically. Porous particles of hydroxyapatite (PPHAP), porous blocks of hydroxyapatite (PBHAP), and LPM did not induce detectable cartilage formation. In straight tunnel structures with various diameters in honeycomb-shaped hydroxyapatite (HCHAP), tunnels with smaller diameters (approximately 0.1 mm) induced cartilage followed by bone formation, while one with a larger diameter (0.35 mm) directly induced bone formation within the tunnels. It is concluded that the "vasculature-inducing geometry" of the carrier as an ECM is crucially important for osteogenesis.

Animals↗

PubMed2002

Analysis of chromosome 6q deletion in EBV-associated NK cell leukaemia/lymphoma.

Deletions involving chromosome 6q have been reported in a number of human cancers such as ovarian and breast tumours as well as haematopoietic malignancies. It seems that this region might contain tumour-suppressor genes. Putative natural killer cell lymphomas/leukaemias (NKLL) represent a group of recently characterized haematolymphoid malignancies sharing an immunophenotype of CD3/Leu4- CD3epsilon+ CD56+, a genotype of germline T-cell receptor genes, and have a close association with Epstein-Barr virus (EBV). Deletion at 6q21-q25 was demonstrated in three recently reported cases of NKLL. Here we investigated the possible involvement of 6q deletions in the pathogenesis, and especially the tumorigenesis of NKLL. The regions of D6S1574 (6p25), DS276 (6p12), D6S257 (6q11), D6S434 (6q14), D6S287 (6q15), D6S292 (6q21), D6S308 (6q22), D6S264 (6q25), and D6S446 (6q26) were analysed by PCR in 25 cases of NKLL, including seven cases with chronic NK leukaemia, six with acute NK leukaemia and 12 with NK lymphoma. 6q deletions, especially 6q15-25, were frequently detected, but 6p deletions were not detected in any cases. Analysis of 6q21 showed possible deletion in two of seven cases (29%) with chronic NK leukaemia, three of six (50%) with acute leukaemia, and 12 of 12 (100%) with NK lymphoma. The frequency of deletion increased in clinical phases. In three cases with lymphoma, fluorescence in situ hybridisation was performed, which confirmed 6q21 deletion in two cases, although 6q telomeric and centromeric regions were preserved. The other case failed to show deletion. Our results suggest that 6q deletion, especially 6q21-25, might be involved in NKLL tumorigenesis, and support the presence of the tumour suppressor genes associated with the development of NKLL.

Adolescent↗

PubMed2002

Chromosomal and comparative genomic analyses of HHV-8-negative primary effusion lymphoma in five HIV-negative Japanese patients.

A rare subset of HIV lymphoma, known as primary effusion lymphoma (PEL), is a high-grade tumour carrying human herpes virus 8 (HHV-8). Very little is known about genomic aberration in PEL, and only a few HIV-negative PEL have been reported. Here we report the results of chromosomal analysis and comparative genomic hybridisation (CGH) conducted to detect regions of gain and loss, in five HIV-negative Japanese cases of HHV-8-negative PEL. All patients except one (35-year-old female) were elderly men and the morphologic examination showed large cell type. PEL expressed B-cell-associated and activation-associated antigens, and exhibited clonal immunoglobulin genes. No HHV-8 was detected in all four examined cases, but Epstein-Barr virus (EBV) was detected in one case. Genomic abnormalities and aberrations were identified in all HHV-8/HIV-negative PEL. CGH studies showed gain in 19 of 24 chromosomes. Gains of 3q13-27, 8q24, 10q21-23 and Yq were detected in two of the five cases, but other gains were noted in each case. Chromosomal analysis revealed complex abnormalities both in numbers and structures. Burkitt lymphoma-associated t(8;22) was detected in one case, but +8 chromosome and c-myc amplification were detected in the other three cases by Southern blot and/or fluorecence in situ hybridization (FISH). Abnormality of chromosome 8, which associates with c-myc, was detected in four of the five HHV-8/HIV-negative PEL. However, the other common genomic abnormalities of HHV-8/HIV-negative PEL were not detected in our study, but the complex abnormalities seemed to be true rather than the usual large B-cell lymphoma. Our results suggest that multi-step genomic abnormalities might be associated in HHV-8/HIV-negative PEL tumorigenesis.

Adult↗

PubMed2002

Interferon-gamma, interleukin-18, monokine induced by interferon-gamma and interferon-gamma-inducible protein-10 in histiocytic necrotizing lymphadenitis.

Apoptosis of histiocytes is a characteristic feature of necrotizing lymphadenitis (HNL). Recent studies have indicated that Fas and perforin-based pathways are involved in the apoptotic process of HNL. Elevated levels of serum interferon (IFN)-gamma are reported in HNL. The CXC chemokine interferon-gamma-inducible protein-10 (IP-10) and monokine induced by interferon-gamma (MIG) cause tissue necrosis, and interleukin (IL)-18 induces the expression of IFN-gamma and Fas ligand (FasL) by T and natural killer (NK) cells. This study was designed to determine the expression of IFN-gamma, IL-18, MIG and IP-10 in HNL. Ten cases of HNL were analyzed by using immunohistochemical staining and/or reverse transcriptase-polymerase chain reaction (RT-PCR). As a control, we included four cases of non-specific lymphadenitis. MIG and IP-10 proteins, which enhance the release of granzyme, showed a similar distribution pattern in viable tissues surrounding dead tissue, mostly within histiocytes, and lymphocytes in HNL. IL-18 was located within histiocytes, especially phagocytic histiocytes, but not within lymphocytes. In addition, IFN-gamma-positive lymphocytes were frequently detected in the surrounding dead tissue, and the lymphocytes in the same area were frequently positive for CXCR3, a specific receptor of MIG and IP-10. In non-specific lymphadenitis, MIG, IP-10 and IL-18 positive cells were detected, but their numbers were relatively small compared with HNL, while IFN-gamma positive cells were rarely encountered. Our findings suggest that the cytokine and chemokine pathways of IFN-gamma, IL-18, MIG and IP-10 play an important role in the pathogenesis of apoptosis associated with HNL.

Adolescent↗

PubMed2002

Characterization of RecA424 and RecA670 proteins from Deinococcus radiodurans.

RecA protein is considered to be the most important participant in the radiation resistance of Deinococcus radiodurans. However, it is still unclear how RecA contributes to the resistance. In this study, we identified a new recA mutation (recA424) in the DNA-repair deficient mutant strain KI696, the phenotype of which is remarkably different from mutant strain rec30 carrying recA670. The properties of the gene products from the recA mutants were compared. recA424 could not complement the deficiency in Escherichia coli RecA, as found for recA670. In vitro, neither RecA424 nor RecA670 could promote DNA strand exchange under conditions in which wild-type RecA promoted the reaction, indicating that both RecA424 and Rec670 are defective in recombination activity. RecA424 promoted the autocleavage reaction of LexA in vitro, whereas RecA670 did not. The intracellular LexA level in KI696 was decreased following gamma-irradiation. However, the LexA level in strain rec30 was constant irrespective of irradiation. These results indicate that RecA424 retains co-protease activity, whereas RecA670 does not. While strain rec30 is extremely radiation sensitive, strain KI696 is only slightly sensitive. Together, these observations suggest that the co-protease activity rather than the recombination activity of RecA contributes to radiation resistance in D. radiodurans.

Bacteria↗

PubMed2002

Cerebellar arteriovenous malformation with facial paralysis, hearing loss, and tinnitus: a case report.

OBJECTIVE: To describe cerebellar arteriovenous malformation in a 21-year-old man with symptoms resembling those of ear disease and to discuss the relationship between the findings of neurotologic examination and magnetic resonance imaging. STUDY DESIGN: Case report. SETTING: Department of Otolaryngology, Head-and-Neck Surgery of the Kyoto University Hospital, which is a tertiary care center, in Kyoto, Japan. PATIENT: A 21-year-old man had cerebellar arteriovenous malformation and symptoms resembling those of ear disease: recurrent left facial paralysis, left retrocochlear hearing loss, and tinnitus. Auditory brainstem responses showed only waves I and II on his left side. Downbeat nystagmus was seen by anteflexion and retroflexion of his neck. He also experienced a slight sensory disturbance on the left side of his face and right lower extremity. Magnetic resonance imaging and vertebral angiography revealed a cerebellar arteriovenous malformation and a varix functioning as a drainer of the arteriovenous malformation surrounded by an edematous region probably induced by a small hemorrhage in the brainstem. INTERVENTION: Conservative treatment, including intravenous prednisolone, vitamin B12, and oral adenosine triphosphate was performed followed by total extirpation of the arteriovenous malformation. CONCLUSION: In examining patients with peripheral facial paralysis (sometimes recurrent with a short interval) and other symptoms resembling those of ear disease, especially those suggesting certain central disorders, it is important to take intracranial arteriovenous malformation into consideration because the condition may be sometimes life threatening if overlooked.

Adult↗

PubMed2002

Establishment and characterization of a novel human desmoplastic small round cell tumor cell line, JN-DSRCT-1.

The exact nature of the desmoplastic small round cell tumor (DSRCT) remains controversial. More detailed analyses might be facilitated by the establishment of permanent DSRCT cell lines. To date, however, no human DSRCT cell line has been reported. In this study, we report the establishment of a new human cell line, JN-DSRCT-1, from the pleural effusion of a 7-year-old boy with pulmonary metastasis from a typical intra-abdominal DSRCT. JN-DSRCT-1 cells were small round or spindle shaped with oval nuclei and have been maintained continuously in vitro for over 190 passages during more than 40 months. Histologic features of the heterotransplanted tumors in severe combined immunodeficiency mouse were essentially the same as those of the original DSRCT, revealing nests or clusters of small round cells embedded in an abundant desmoplastic stroma. Both in vitro and in vivo, the cells exhibited immunopositive reactions for vimentin, desmin, cytokeratins (AE1/AE3 and CAM 5.2), epithelial membrane antigen, neuron-specific antigen, and CD57 (Leu-7). JN-DSRCT-1 cells exhibited a pathognomonic t(11;22)(p13;q12) translocation by cytogenetic analysis. In addition, RT-PCR and sequencing analysis revealed a chimeric transcriptional message of the Ewing's sarcoma gene exon 10 fused to the Wilms' tumor gene exon 8. To our knowledge, this is the first permanent human DSRCT cell line. The JN-DSRCT-1 cell line, which exhibits the unique morphologic and genetic characteristics of DSRCT, will be extremely useful for a variety of important studies such as the pathogenic mechanism, biologic behavior, and therapeutic model of human DSRCT.

Abdominal Neoplasms↗

PubMed2002

Primary central nervous system lymphoma: the clinical features and treatment of 22 cases.

OBJECTIVE: To clarify the efficacy of chemotherapy after radiation therapy in immunocompetent patients with primary central nervous system lymphoma (PCNSL). PATIENTS AND METHODS: A retrospective analysis of 22 PCNSL patients was performed. Twenty-two patients were divided into a combined treatment (chemotherapy after radiation) group and a radiation group. The survival curves, calculated according to the Kaplan and Meier method, were compared using the Log-rank and Wilcoxon statistical analyses. RESULTS: Eight patients were treated with radiation therapy alone, and their median survival time (MST) after diagnosis was 21.9 months. Fourteen patients were treated with chemotherapy after radiotherapy. Six patients received chemotherapy consisting of cyclophosphamide, adriamycin, vincristine and prednisolone (CHOP), while 6 patients received carboplatin-based chemotherapy and 2 patients received methotrexate-based chemotherapy. The MST of these 14 patients was 34.4 months, which was not significantly better than that of the radiation therapy group (p=0.159). Leukoencephalopathy occurred in 3 patients, who received whole brain radiation. CONCLUSION: The use of chemotherapy after radiation has up to now been thought to be a standard treatment modality but CHOP or carboplatin-based chemotherapy did not improve the survival time.

Adult↗

PubMed2002

p53 Gene mutation and genetic instability in superficial multifocal esophageal squamous cell carcinoma.

Tumor multicentricity is occasionally observed in esophageal squamous cell carcinoma (SCC). We studied five surgically resected superficial multifocal esophageal SCCs for p53 gene mutation and genetic instability, using DNA extracted from microdissected areas. A total of 38 target areas (TAs) were analyzed in SCC, dysplasia, basal cell hyperplasia (BCH) and normal squamous epithelium. Analysis of the replication error (RER) at 10 microsatellite loci showed microsatellite instability in all TAs, as well as in normal squamous epithelium. p53 gene mutation was identified in 28.9% (11/38 TAs). All cases showed a common missense mutation in exon 8 at codon 273 (CGT-->CAT, Arg-->His), which was DNA contact mutation in the S10 beta strand. In association with microsatellite alterations, 7 of 9 TAs with p53 mutation in exon 8 at codon 273 also showed loss of heterozygosity (LOH) of p53 gene. LOH of p53 gene was detected in 83.8% (31/37 TAs). LOH at D2S123 on 2p16 near MSH2 gene and at D3S1611 on 3p22 near MLH1 gene was detected in 65.4% (17/26) and 71.4% (10/14) TAs, respectively. Frequencies of LOH at p53 and D2S123 were similar in non-cancerous areas and SCCs. LOH of p53 and D2S123 were found in 50% (5/10 TAs) of non-cancerous areas and 60% (9/15 TAs) of SCCs. Our results suggest that genetic instability induces esophageal tumor multicentricity, and that p53 gene contact mutation together with LOH are early events of the multistage carcinogenesis of multifocal primary esophageal SCC.

Carcinoma, Squamous Cell↗

PubMed2002

[CD5+ CD10+ extranodal B-cell lymphoma with tetraploid chromosomal abnormality].

An 84-year-old man was admitted with pleural lymphomatous effusion and bone marrow infiltration. The abnormal cells from the effusion showed abundant basophilic cytoplasm, large atypical nuclei, and small nucleoli with frequent mitosis. The abnormal cells were found to be CD5+, CD10+, CD19+, and CD20+ by flow cytometry, and had clonal rearrangements of the IgH-JH gene, indicating the existence of a clonal B-cell population. No bcl-1, bcl-2, bcl-6, or c-myc rearrangement was found. Neither human herpesvirus 8 (HHV-8) nor Epstein-Barr virus was detected in the abnormal cells. Tetraploid chromosomal abnormality was present. After administration of prednisolone, transient disappearance of the effusion was obtained.

Aged↗

PubMed2002

Establishment of a new human synovial sarcoma cell line, FU-SY-1, that expresses c-Met receptor and its ligand hepatocyte growth factor.

Only a small number of human synovial sarcoma cell lines have been reported, and of those, not all have been fully characterized, especially at the molecular level. We describe here the establishment and characterization of a new human cell line, FU-SY-1, which originated from a monophasic fibrous synovial sarcoma arising in the supinator muscle of a 31-year-old woman. This cell line propagated continuously in vitro for 73 serial passages for more than 36 months. FU-SY-1 cells in vitro were rather small, exhibited a spindle or polygonal shape without conspicuous pleomorphism, and expressed c-Met and hepatocyte growth factor (HGF) as determined by immunocytochemistry. Cytogenetically, FU-SY-1 cells maintained a consistent karyotype: 47, X, +7, t(X;18)(p11.2;q11.2), the same as that of the original tumor specimen. Reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated a SYT-SSX fusion transcript and expression of c-Met and HGF mRNA in FU-SY-1 cells. A subsequent sequence analysis using the PCR products confirmed that the detected messages were derived from the SYT-SSX1 fusion gene. This cell line, FU-SY-1, established from a monophasic fibrous synovial sarcoma, may therefore be a useful tool for investigation of the mechanisms of tumorigenesis and progression in human synovial sarcomas.

Adult↗

PubMed2002

Gain of Xq detected by comparative genomic hybridization in elastofibroma.

Elastofibroma is a rare, benign, slow-growing degenerative pseudotumor that typically occurs in the subscapular region and has been considered a peculiar fibroblastic proliferation with accumulation of abnormal elastic fibers. Very little is known about the cytogenetic and molecular genetic changes in elastofibroma. In the present study, we analyzed DNA copy number changes in 27 elastofibromas by comparative genomic hybridization. DNA was extracted from 22 archival paraffin-embedded tumor tissues and from 5 fresh frozen samples. Nine (33%) of the 27 cases exhibited DNA copy number changes involving one or two chromosomes, whereas the remaining 18 cases exhibited no DNA copy number changes. The majority of the changes were gains (8 cases), whereas 2 cases showed losses. The most common recurrent gains were at chromosomal locations Xq12-q22 (6 cases) and 19 (2 cases). High-level amplifications and recurrent losses were not observed. There was no correlation between DNA copy number changes and the pseudotumor size. The present study has identified a chromosomal region that may contain genes involved in the development of at least some elastofibromas.

Adult↗

PubMed2002

Cartilage intermediate layer protein expression in calcium pyrophosphate dihydrate crystal deposition disease.

OBJECTIVE: To elucidate the mechanisms of calcium pyrophosphate dihydrate crystal deposition disease (CPPDCD) in the meniscus, synovium, labrum, tendon, ligament, and soft tissue, we studied the expression of cartilage intermediate layer protein (CILP). METHODS: Histological sections and clinical data from 33 patients who fulfilled the criteria of Ryan and McCarty for CPPD were reviewed. Formalin fixed and paraffin embedded tissue sections of 33 patients with CPPDCD were stained with hematoxylin and eosin (H&E) and alizarin red S. Immunostaining was performed using affinity purified polyclonal antibody to synthetic peptide corresponding to the N-terminal sequence of the 61 kDa domain of porcine CILP. RESULTS: The age of patients ranged from 49 to 89 years (median 73). The knee was the commonest site. Radiologically, almost all lesions exhibited fine, radiopaque, linear deposits in the meniscus, articular cartilage, and synovium or joint capsule. Histopathologically, all cases showed deposits of birefringent monoclinic or triclinic crystals, which were visualized by polarized light microscopy with a red analyzer filter. In alizarin red S staining, more numerous crystals were observed than in H&E staining. Crystal deposition was usually associated with adjacent variable amounts of hypertrophic and/or metaplastic chondrocytes in each type of tissue. Variable intensity of CILP immunostaining was found in deposits of each lesion. Hypertrophic/metaplastic chondrocytes in and around CPPD deposits were also positive for CILP. Small cartilaginous islands remote from the CPPD deposits exhibited a weak positivity for CILP. In addition, weakly positive chondrocytes were noted in a transitional zone between cartilaginous islands with and without the deposits. In addition to cytoplasmic immunoreactivity, immunostaining for CILP was observed in the pericellular fibrous matrix. CONCLUSION: Hypertrophic or metaplastic chondrocytes characteristic of CPPDCD may be directly involved in the formation of CPPD crystals. Our study suggests that increased CILP expression was closely associated with CPPDCD, and might play a role in promoting CPPD crystal formation.

Aged↗

PubMed2002

Overexpression of heterogeneous nuclear ribonucleoprotein B1 in lymphoproliferative disorders: high expression in cells of follicular center origin.

It is reported that overexpression of hnRNP A2 and B1 proteins is useful for detecting early cancers, and that B1, a splicing minor isoform of A2, is more specific than A2. The B1 expression is still undetermined in human lymphoid tissues. We quantitatively studied the B1 expression in 85 lymph node specimens, comprising reactive lymphoid hyperplasia (RLH; n=8), B-cell lymphoma (n=23), T-cell lymphoma (n=22), and metastatic carcinoma (n=32). Immunostaining and immunoblotting analyses with an anti-B1 monoclonal antibody, 2B2 were performed, and the two sets of results correlated with each other (p<0.05). In RLH specimens, B1 expression rate was significantly higher in follicular centers (FC; 44%) than in mantle zone (MZ; 15%) and paracortex (16%) (p<0.01). B1 expression was statistically higher in B-cell lymphoma than in T-cell lymphoma (p<0.01). In B-cell lymphomas, B1 expression rates were 51% in diffuse large B-cell lymphoma (DLBL; n=5) and 45% in follicular lymphoma (FL; n=16), and they were almost the same as that of the FC. Especially in DLBLs, CD10+ FC-origin lymphomas expressed greater amount of B1 than CD10- non-FC-origin lymphomas. B1 expression rate was low in mantle cell lymphoma (MCL; n=2) and similar to that of MZ in RLH. These results suggest that B1 expression is associated with differentiation in lymphoid tissue rather than transformation. B1 expression increases during the process of B-cell differentiation in the FC, and that high B1 expression is maintained in B-cell lymphomagenesis, especially in cells of FC-origin DLBL.

Adolescent↗

PubMed2001

Classification of cell lineage and anatomical site, and prognosis of extranodal T-cell lymphoma -- natural killer cell, cytotoxic T lymphocyte, and non-NK/CTL types.

Due to their minority among the non-Hodgkin lymphomas, classification of extranodal T-cell lymphomas, including those of the natural killer (NK) cell type, has long been controversial and unclear, and the clinical outcome is not well clarified. Recently, new well-defined disease entities have been described based on tumor cell biology combined with anatomical site, clinical features, Epstein-Barr virus (EBV) status, and cell lineage as determined by immunophenotype and genotype. Cytological features are usually not specific, and there are no morphologic correlates with the classification of extranodal T/NK-cell lymphomas. From a human T-cell lymphotropic virus type 1 (HTLV-1) endemic area in Japan, we report here the analysis of 144 cases of extranodal T-cell lymphoma, from which fresh tissues were available. As the clinicopathological features were known, we simply reclassified the cases according to cell lineage and anatomical site. The extranodal T-cell lymphomas were classified into three types on the basis of cell lineage: (1) natural killer cell (NK) type [sCD3-, CD56+, T-cell receptor gene (TCR) germline], (2) cytotoxic T lymphocyte (CTL) type [sCD3+, TIA-1+, TCR rearranged, CD8+/-, CD4-/+], and (3) non-NK/CTL type [sCD3+, TIA-1-, TCR rearranged, CD4+/-, CD8-/+]. In addition to cell lineage, the anatomical site and clinical features were added for subclassification. NK type tumors (35 cases) included the lymphoblastic type, nasal/nasal-type NK lymphoma, and NK leukemia. The CTL type (46 cases) included anaplastic large cell lymphoma (ALCL), cutaneous type, intestinal, gamma delta T-cell type, and an unspecified type. The non-NK/CTL type (63 cases) included adult T-cell leukemia/lymphoma (ATLL), mycosis fungoides (MF), and an unspecified type. With the exception of ATLL and MF, most extranodal T-cell lymphomas had a cytotoxic phenotype of NK type or CTL type and were often associated with EBV infection. MF and the unspecified type within the non-NK/CTL tumors, with the exception of ATLL, had a favorable prognosis. However, NK and CTL types, with the exception of ALCL, were associated with a poor prognosis. Our results indicate that anatomical site and cell lineage are useful predictors of clinical outcomes of extranodal T-cell lymphomas.

Antigens, CD↗

PubMed1999

Analysis of immunoglobulin light-chain mRNA in gastric malignant lymphoma using new highly sensitive in situ hybridization method.

BACKGROUND: To analyze B-cell monoclonality, we need fresh materials for the Southern blotting method. In situ hybridization (ISH) for the detection of immunoglobulin light-chain mRNA can be used in formalin-fixed and paraffin-embedded tissues. However, it is difficult to detect low levels of mRNA copies. So we must develop new highly sensitive in situ hybridization methods to diagnose gastric malignant lymphoma.METHODS: We analyzed materials from 15 patients with gastric malignant lymphoma, using a new highly sensitive ISH method, and compared the results with those of a conventional method.RESULTS: With this new method, 13 of 15 cases were shown to have monotypic cytoplasmic signals, and monoclonality was detected in 3 of 4 cases of mucosa-associated lymphoid tissue (MALT) lymphoma.CONCLUSIONS: The accuracy of endoscopic biopsies is not satisfactory. However, the detection of immunoglobulin light chain mRNA, using the new highly sensitive ISH method with a non-radioactive isotope oligonucleotide probe, can be used to diagnose gastric malignant lymphoma even when conventional immunoglobulin light-chain mRNA or proteins alone cannot demonstrate the clonality.

Journal Article↗

PubMedDate not supplied

Suppression of stress immobilization-induced phosphorylation of ERK 1/2 by biting in the rat hypothalamic paraventricular nucleus.

We have previously reported that acute immobilization stress induces Fos protein. Fos protein is generally used as a marker for neuronal activity and has been linked to phosphorylation of extracellular signal-regulated protein kinase 1/2 (pERK1/2), in the hypothalamic paraventricular nucleus (PVN). Biting behavior during the period of stress reduced the expression of Fos protein. The present immunohistochemical study was designed to determine whether acute immobilization stress induces pERK1/2 in the PVN, and whether the stress-induced pERK1/2 was attenuated by simultaneous biting behavior. Acute immobilization stress, in increments of up to 15min, produced detectable amounts of pERK1/2 that were proportional to the interval of stress. Biting during the acute immobilization stress significantly reduced the amount of detectable pERK1/2. These results suggest that biting activity during acute stress inhibits pERK1/2 in this region of the brain. It is feasible that the neuronal cellular response to acute stress is regulated, in some part, by inhibition of pERK1/2 by biting.

Aggression↗

PubMedDate not supplied

Peripheral T-cell lymphoma with a nodular growth pattern.

Peripheral T-cell lymphomas (PTCL) with nodular growth patterns are very rare, with only 17 cases reported previously. Here, we report a case of PTCL with a nodular growth pattern. The patient was an 81-year-old Japanese woman who complained of malaise, fever and generalized lymph node swelling. Cervical lymph node biopsy was performed, and histological examination revealed proliferation of medium- to large-sized atypical lymphoid cells with indented to irregular nuclei, distinct nucleoli and clear cytoplasm. The nodular growth pattern of the lymphoma cells was obvious. On immunohistochemistry, the atypical lymphoid cells proved to be of T-helper cell origin (CD2+CD3CD4+CD5+CD7+ CD8-CD10-CD25-CD30-CD57-). Polymerase chain reaction analysis of the T-cell receptor gamma-chain revealed a monoclonal rearrangement band. This unusual growth pattern should be distinguished among PTCL, as such cases could be confused with reactive nodular hyperplasia, nodular lymphoma, mantle cell lymphoma and marginal zone lymphoma with nodular colonization.

Aged↗