VH gene family utilization of anti-acetylcholine receptor antibodies in experimental autoimmune myasthenia gravis

The immunoglobulin heavy chain (VH) gene family usage in experimental autoimmune myasthenia gravis (EAMG) model was investigated by RNA slot blot hybridization using VH gene family specific probes. Anti-acetylcholine receptor (AChR) monoclonal antibodies (mAbs) isolated from susceptible C57BL/6 and resistant BALB/c mice were found to be encoded by VH genes from at least six different families. The Vgam3.8 family was overrepresented in alpha-bungarotoxin blocking mAbs. Expression of cross-reactive idiotypes by anti-AChR mAbs was irrespective of the VH gene family usage. Strain dependent differences in susceptibility for EAMG were not reflected in an aberrant VH gene family usage of anti-AChR mAbs.     

Initial chemotherapy for primary resectable large-cell lymphoma of the stomach

BACKGROUND: We aimed to evaluate the safety and effectiveness of a conservative approach with short-term chemotherapy with or without consolidation radiotherapy in primary resectable large-cell gastric lymphoma in patients not requiring emergency surgery at presentation. PATIENTS AND METHODS: Seventeen consecutive patients presenting with resectable primary large-cell lymphoma of the stomach not requiring immediate surgery were initially treated with chemotherapy with or without consolidation radiotherapy. Subtotal or total resection of the stomach was planned only as salvage treatment for those patients who failed locally, or as emergency surgery in instances of acute iatrogenic complications of treatment. Chemotherapy included four to six cycles of an anthracycline-containing regimen, and consolidation radiotherapy was planned on the entire stomach and surrounding lymph node areas for complete responders readily capable of compliance with a daily treatment schedule at our Institution. RESULTS: None of the patients in the present series experienced acute iatrogenic morbidity or mortality from local complications. After a median follow-up of almost six years, two patients failing first-line chemotherapy have died of progressive lymphoma, while 15 patients are well and currently disease-free. CONCLUSIONS: Up-front chemotherapy as initial treatment for primary gastric large-cell lymphoma appears to be a safe and effective treatment by which most patients can probably be spared surgical gastrectomy. Consolidation radiation therapy on the stomach can probably improve on the effectiveness of chemotherapy alone. More experience is needed to elucidate the prognostic factors, treatment-related long-term toxic effects and the feasibility of such a treatment administered outside of highly specialized institutions.     

An anatomo-clinical case of dementia in endovascular large-cell lymphoma

Cerebral angiotropic large cell lymphoma is a rare fatal neurologic disorder characterized by multifocal intravascular proliferation of large pleomorphic cells within vessels of all caliber, predominantly skin and nervous system. Clinical manifestations in previously reported cases were dominated by focal neurologic signs, epilepsia and progressive dementia. We report a case of a 70 year-old man with subacute dementia, epileptic seizures and cerebrovascular events. There was no evidence of a systemic disease outside the nervous system. Cerebrospinal fluid contained 13 leukocytes/mm3 (49% of lymphocytic cells) and more than 100 mg/dl of protein. Cytology was negative. Cranial MRI demonstrated cerebral atrophy and an increased paraventricular signal in T 2 weighted images. A frontal brain biopsy revealed only neuronal dystrophy and astrocytic gliosis. Despite treatment with corticosteroids the patient died 18 months after the onset of the first symptoms. Autopsy was performed and revealed B cell lymphoma.     

Anaplastic large-cell lymphoma of null-cell type with multiple bone involvement

The knowledge on the functional structure of the spleen is gained from the analysis of diseases, and immunological studies. Significant information is gained from model tests and isolated cells. The latter is advantageous in coincidence with the studies of intercellular relations. The main function of the spleen resides in "purification" of the blood. The vascular system, white pulp, red pulp and the marginal zone participate in this process. T-dependent zones of the white pulp are restricted by the circumference reticulum (CR) of periarterial lymphatic sheaths. CR is a morphologic substrate of retro-directional flow of lymphocytes. In addition to T lymphocytes and a certain amount of B lymphocytes, the T-dependent zones contain interdigitizing cells. The B-dependent zones, in addition to lymphocytes, contain dendrite reticular cells. The cords are constituted by varied cellular and extracellular compartments, especially macrophages, fibroblastic reticular cells and various fibrous components. The latest filtration barrier is formed by the wall of sinuses of the red pulp. The achievement of new functional knowledge resides prospectively in the use of lectins, anti-collagen antibodies, fibronectins, proteoglycanes and other various molecules participating in intercellular relations, or morphometric studies, they can provide information on the newest subpopulations of cells in both red and white pulp, that are so far inaccurately defined.     

Biased VH family usage in primary gastric B cell lymphoma of mucosa-associated lymphoid tissue-type and the selected V beta expression of T cells infiltrating into the lymphoma cells

Seven cases of primary gastric low-grade B cell lymphoma of mucosa-associated lymphoid tissue (MALT) type, two cases of high-grade B cell lymphoma with a low-grade component and three cases of pure high-grade lymphoma were selected for the current study. The Ig VH gene use of lymphoma cells and the V beta repertoires of infiltrating T cells were investigated. The VH gene analysis showed multiple VH family usage in 12 cases, but the MALT-type lymphoma cell usage was found to be biased for the families that have a low number of VH genes (VHIV and V). Another analysis of lymphoma-infiltrating T cells showed restricted expressions of the V beta repertoire in all seven low-grade cases and three high-grade cases. In those 10 cases, a considerable number of CD4-positive T cells infiltrated into lymphoma cells and RAG-1 was also prominently expressed. Based on these findings, it was thus assumed that the normal counterpart of gastric B cell lymphoma of MALT type is different from the conventional B cell lymphoma, and the restricted expression of V beta repertoires is therefore considered to be a characteristic finding in low-grade B cell lymphomas of MALT type as well as in a proportion of high-grade lymphomas (the so called 'high-grade lymphoma of MALT type').     

系统性间变性大细胞淋巴瘤骨髓累及的临床病理学研究

目的 探讨系统性间变性大细胞淋巴瘤(S-ALCL)骨髓累及的临床病理学特点、免疫学表型及临床生物学行为.方法 回顾性分析34例S-ALCL病例资料,进行骨髓活检(19例)或涂片(15例).其中ALK(+)24例,ALK(-)10例.HE染色、免疫组织化学染色观察病理形态及免疫表型,原位杂交法检测EB病毒.结果 6例(17.6%)S-ALCL存在骨髓累及,均经骨髓活检标本确定,15例患者骨髓涂片中均未见肿瘤累及.ALK(+)ALCL和ALK(-)ALCL骨髓累及的发生率分别为16.7%(4/24)和20.0%(2/10),差异无统计学意义(P=0.3555).与无骨髓累及病例比较,骨髓累及病例的年龄、性别分布差异无统计学意义(P值分别为0.8089和0.3085).骨髓累及者肿瘤细胞以间质性分布为主[83.3%(5/6)].生存分析统计提示伴有骨髓累及的患者预后明显差于无骨髓累及者(P=0.0407).结论 S-ALCL骨髓累及发生率低,与患者的发病年龄、性别及ALK蛋白的表达无相关性.伴有骨髓累及的S-ALCL患者临床预后差,骨髓活检在判断S-ALCL预后中有重要意义.     

Ki-1 anaplastic large-cell lymphoma in the differential diagnosis of unknown primary cancer

Infant pulmonary function tests (PFTs) have proven increasingly popular and useful for clinical and research purposes. Informed consent requires accurate information on side effects. Our aim was to quantify minor side effects from a parental point of view by means of a questionnaire. The parents of 97 infants attending for PFTs were asked to complete a simple questionnaire. Eighty-one parents (84%) returned the questionnaire. Forty-one percent felt that their infants were not troubled by the process of administering the sedative chloral hydrate, whereas 55% suffered mild to moderate distress. In contrast, 94% of infants were not distressed by the actual PFTs. Similarly, 46% of parents were not distressed by the administration of sedative to their infant, with 49% expressing distress to a mild or moderate degree. Although 73% of parents were not distressed by watching their infants undergo the PFTs, 27% were to a mild to moderate degree. Seventy-three percent of infants were untroubled on waking. Seventy percent of infants had a good nights sleep after the PFTs. The vast majority of parents (94%) were happy to recommend that others allow their infants to undergo similar testing. We noted that most problems caused by infant PFTs relate to the administration of the sedative. Most infants awake from the tests not distressed and sleep normally the following night.     

BCL6 gene rearrangement and other cytogenetic abnormalities in diffuse large cell lymphoma

Evidence for rearrangement of the BCL6 gene at 3q27 has been documented in 20-30% diffuse lymphomas with a large cell component (DLLC), and was found to be of prognostic significance at the time of diagnosis. To incorporate these observations into current cytogenetic and clinical prognostic models, 76 cases of DLLC with known BCL6 status were analyzed. Cytogenetic indicators of progression, including trisomy 7, trisomy 12, del(6)(q21q25), and structural alterations of 17p were less frequent in BCL6 rearranged DLLC compared to BCL6 germline tumors. Despite a 93% overall survival at median follow-up of 30 months, a trend for continued relapse resulted in a projected freedom from progression for the BCL6 rearranged cohort of 66% at 4 years, compared to 39% for the BCL6 germline cohort. Six cases among the BCL6 rearranged group lacked additional cytogenetic indicators of progression and remained free of disease at follow-up in excess of 7 years, whereas BCL6 rearranged cases with increasing numbers of cytogenetic aberrations showed decreased intervals free from progression of disease. These results suggest that BCL6 rearrangement should be combined with other known clinical and cytogenetic indicators in prognostic analyses of patients with DLLC.     

Cytotoxicity of murine B lymphocytes induced by human VH4-34 (VH4.21) gene-encoded monoclonal antibodies

We previously found that a ventricular isovolumic pressure-time curve could be well fitted by the difference between two S-shaped logistic curves for the pressure rising and falling components, and called it "hybrid logistic" function: P(t)=A/[1+exp[-(4B/A)(t-C)]]-D/[1+exp[-(4E/D)(t-F)]]+G. We reported that the parameters of this hybrid logistic function are useful to characterize left ventricular contraction and relaxation comprehensively. In this study, we investigated how well this hybrid logistic function could fit the isometric twitch force-time curves of cross-circulated right ventricular papillary muscles of 7 dogs. This function precisely fitted the isometric force curves with correlation coefficients above 0.9996, much better than another fitting function (F(t)=C(t/A)(B)exp[1-(t/A)(B)]) proposed by Nwasokwa. The present results indicate that our hybrid logistic function can also reasonably express the canine right ventricular papillary muscle isometric twitch force-time curve. We suggest the possibility that the parameters of this hybrid logistic function are also useful to comprehensively characterize right ventricular papillary muscle twitch contraction and relaxation.     

Frequent expression of the NPM-ALK chimeric fusion protein in anaplastic large-cell lymphoma, lympho-histiocytic type

The revised European-American lymphoma classification recognizes a subtype of anaplastic large-cell lymphoma (ALCL), termed lympho-histiocytic because of its peculiar cytological composition. As in the case of classical ALCL, this tumor usually occurs in young patients and shows an excellent response to chemotherapy, but some authors have suggested that in reality this is a nonanaplastic T-cell lymphoma rich in histiocytes. In this paper, we show that three of five cases of lympho-histiocytic ALCL stain with anti-ALK antibodies and can therefore be presumed to express the chimeric NPM/ALK protein secondary to (2;5) translocation. These findings further support the inclusion of this as a type of ALCL and not among the nonanaplastic peripheral T-cell lymphomas. Furthermore, they indicate that staining for ALK proteins is a powerful tool for the diagnosis of lympho-histiocytic ALCL, the recognition of which may be difficult on morphological grounds.     

V region diversity in human anti-insulin antibodies. Preferential use of a VHIII gene subset

Data on structures used by human antibody repertoires are derived principally from lymphoid malignancies and from autoantibodies that often express VH genes from the developmentally regulated fetal repertoire. To determine whether human immune responses generated by exogenous Ag use a pool of VH genes distinct from the fetal repertoire, nucleotide and predicted amino acid sequences were determined for five anti-insulin B cell clones from a type I diabetic patient treated with human insulin. The data show that a set of VHIII genes is preferentially used by human anti-insulin B cells. Structural features indicate that these expressed VH are derived from germ-line genes that are not frequent in fetal repertoires and these genes have undergone Ag-driven somatic mutation. The preferential use of related VH segments contrasts with the BALB/c anti-insulin response, which uses multiple V genes elements largely unmutated from germ-line sequences. In addition, long CDRH3 structures in human anti-insulin mAb are generated by complex gene interaction mechanisms that are not seen in murine anti-insulin mAb. Interestingly, similar potential insulin-binding structures are used by antibodies from both species. These findings suggest that human responses to exogenous insulin may express a limited number of VH genes and depend upon somatic mutation and complex D gene interactions in CDRH3 to expand the repertoire. Although these antibodies bind autologous insulin, VH gene usage and structural features that predominate in the response are not characteristic of the fetal repertoire.     

Dual recognition of lipid A and DNA by human antibodies encoded by the VH4-21 gene: a possible link between infection and lupus

The VH4-21 (V4-34) gene segment, a member of the VH4 family, is expressed early in B-cell maturation and is utilized by approximately 6% of normal adult B lymphocytes. This prevalence indicates an importance of VH4-21 in the B-cell repertoire. The gene also encodes certain autoantibodies being mandatory for pathological IgM anti-red cell antibodies directed against the I/i antigen, and also capable of encoding anti-DNA antibodies. Recognition of I/i antigen or DNA appears to be via two distinct sites on VH, with I/i binding mediated by sequences in the framework region, and DNA binding correlating with the presence of positively charged amino acids in complementarity-determining region 3. However, these positively charged residues appear to suppress the ability of the framework region to interact with I/i, rendering a single sequence monospecific for I/i or DNA. The IgM anti-DNA antibodies also recognize bacterial lipid A, whereas the anti-I/i antibodies do not, indicating that CDR3 may be involved in binding the negatively charged lipid A. Structural similarities between the DNA backbone and lipid A provide a possible explanation for this cross-reactivity. This dual recognition of bacterial antigen and autoantigen provides a potential link between infection and autoimmunity.     

Preferential use of the landmark navigational system by head direction cells in rats.

Previous studies have identified a population of cells recorded in the postsubiculum and the anterior thalamic nucleus (ATN) that discharge as a function of an animal's head direction (HD) in the horizontal plane. The present experiments monitored HD cell activity when rats were confronted with a situation in which directional information from internal sensory sources (e.g., proprioceptive, vestibular, or motor efference copy) conflicted with directional information derived from familiar, external landmarks. Results showed that when a salient, familiar cue was reintroduced to rat's environment into a position that conflicted with the cell's current firing direction, HD cells in both the ATN and the postsubiculum shifted their preferred direction to reflect their originally established orientation with this cue. This finding suggests that sensory inputs onto HD cells from external landmark cues are capable of overriding spatial information developed through internal sensory cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preferential cytotoxic effect of Newcastle disease virus on lymphoma cells

Susceptibility of lymphoma cells (Daudi, HD-Mar) to Newcastle disease virus toxicity was found to be higher than that of lymphoblastoid cells (Milstein) and of resting peripheral blood lymphocyte (PBL). Phytohemagglutinin- and/or pokeweed-mitogen-activated PBL however, exhibited, elevated sensitivity, similar to that of lymphoma cells. The level of cytotoxicity was monitored by cell viability, inhibition of DNA synthesis and release of 51Cr. When Daudi cells were mixed with PBL they were significantly more sensitive to the killing effect of the virus (70% mortality compared to 30% 30 h after infection, P < 0.05). The degree of sensitivity to viral cytotoxicity was unrelated to the efficacy of adsorption, which was similar for all cell lines as shown by immunofluorescent staining and flow cytometry. Also an influenza strain A/PR/8/34 (H1N1) adsorbed but did not affect the viability of any of the cells tested. Our results demonstrate that New-castle disease virus caused preferential damage to lymphoma cells as compared to non-cancerous normal cells.