Monoclonal antibodies to human platelet glycoprotein IIb beta that initiate distinct platelet responses

Hybridomas secreting monoclonal antibodies (MoAbs) to human platelet membrane glycoprotein IIb (GPIIb) were prepared by fusing cells of a mouse myeloma line to spleen cells from a BALB/c mouse immunized with purified GPIIb. Six of the hybridomas secreted MoAbs that recognized epitopes on the 23,000-dalton, disulfide-linked subunit of GPIIb, GPIIb beta. All six of these MoAbs agglutinated platelets in the absence of calcium. The agglutination titers of three of the MoAbs, however, were enhanced between 2 and 6 log2 dilutions when titrated in the presence of mmol/L of calcium. The enhancement in titer was the result of MoAb- induced platelet activation followed by platelet aggregation, a reaction that could also be initiated by the monovalent Fab fragments prepared from one of the MoAbs. The MoAbs did not significantly agglutinate platelets from patients with Glanzmann's thrombasthenia, confirming biochemical evidence that there is a paucity of GPIIb beta in the membranes of these cells. Our results show that MoAbs to epitopes on GPIIb beta initiate distinct platelet responses; therefore, they should be useful for studying the ways in which regions of surface glycoproteins are involved in platelet-platelet interactions. In addition, these reagents may prove of value in diagnosing and typing patients with Glanzmann's thrombasthenia.     

Minactivin expression in human monocyte and macrophage populations

Adherent monolayer cultures of human blood monocytes, peritoneal macrophages, bone marrow macrophages, and colonic mucosa macrophages were examined for their ability to produce and secrete minactivin, a specific inactivator of urokinase-type plasminogen activator. All except colonic mucosa macrophages produced and secreted appreciable amounts of minactivin, but only blood monocytes were stimulated by muramyl dipeptide (adjuvant peptide) to increase production. The minactivin from each of these populations could be shown to preferentially inhibit urokinase-type plasminogen activator and not trypsin, plasmin, or "tissue"-type plasminogen activator (HPA66). A plasminogen-activating enzyme present in monocyte cultures appeared unaffected by the presence of minactivin and could be shown to be regulated independently by dexamethasone.     

Effect of gallium on bone mineral properties

Summary Gallium nitrate is biologically active in blocking bone rsorptionin vitro as well asin vivo. Administration of gallium nitrate to growing rats results in a dose-dependent accumulation of low levels of gallium in bone that is associated with specific changes in the mineral properties of bone. To elucidate in greater detail the changes induced by gallium, the properties of whole and density-fractionated bone samples from control and galliumtreated rats were examined. These studies showed that short-term treatment with gallium nitrate caused an increase in bone calcium and phosphate content. Devitalized bone powder from the gallium-treated rats was less soluble in acetate buffer and less readily resorbed by monocytes. Density fractionation analyses demonstrated that the largest proportion (76% by weight) of powdered metaphyseal bone particles from rats had a density of <2.15 g/cc. Following short-term treatment (14 days) with gallium nitrate (45 mg/kg body weight), a significant increase in the relative proportion of more dense bone (≥2.15 g/cc) was observed (24% for the control vs. 39% for the gallium-treated rats,P<0.01). In the diaphyseal samples, the largest proportion (88% by weight) of the bone powder had a density of ≥2.15 g/cc. After short-term treatment with gallium, a slight decrease in mean diaphyseal particle density was observed. Measurement of calcium accretion with⁴⁵Ca in the gallium-treated rats demonstrated increased specific activity in the metaphyseal bone samples, densities=2.0, 2.1, 2.15, and 2.25 g/cc; the difference was significant only for the 2.25 g/cc fraction. Therefore, short-term treatment with gallium nitrate leads to an increase in the calcium content of mature bone with more dense (more mineralized) bone particles accumulating in the metabolically more active metaphyseal bone. The data provide greater insight into the changes in bone properties induced afterin vivo treatment with gallium nitrate. However, the physiologic mechanisms by which these changes are effected are not known.     

Deep fungal and higher bacterial skin infections in Thailand: clinical manifestations and treatment regimens

BACKGROUND: Deep fungal and higher bacterial skin infections occur fairly frequently in Thailand. METHODS: Cases with a provisional diagnosis of deep fungal and higher bacterial infections were prospectively collected from 1994 to 1997 in the Granuloma Clinic, Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. Demographic data, clinical manifestations, causative organisms, histologic features, treatment, and outcome were investigated. RESULTS: The total cases in a 4-year period numbered 27. The male to female ratio was approximately 1:1. Mycetoma was most common, followed by chromoblastomycosis. Actinomycetoma was similar in incidence to eumycetoma. The only causative organism that could be identified among the mycetoma cases was Cladosporium carrionii, which caused mycetoma of the buttock of an aplastic anemia patient at the site of bone marrow aspiration. Surgical treatment was recommended for eumycetoma. Chromoblastomycosis was caused by C. carrionii and F. compactum and responded well with itraconazole orally. Mycotic abscesses were found in four cases, basidiobolomycosis in two cases, and cutaneous nocardiosis in one case. Cotrimoxazole was recommended in the treatment of actinomycetoma, cutaneous nocardiosis, and basidiobolomycosis. CONCLUSIONS: Localized, chronic, slow, progressive, and usually asymptomatic were the main cutaneous manifestations of deep fungal and higher bacterial skin infections. A skin biopsy for histologic study and culture identification should be performed in every suspected case. The causative organisms were found in the histologic sections of every case, but only about one-third were found by culture.     

Pretibial dystrophic epidermolysis bullosa: a recessively inherited COL7A1 splice site mutation affecting procollagen VII processing

Pretibial epidermolysis bullosa (PEB) is a rare form of localized epidermolysis bullosa dystrophica (EBD), a heterogeneous group of inherited, blistering diseases characterized by scarring, loss of dermal-epidermal adhesion and altered anchoring fibrils (AF). Mutations in the type VII collagen gene (COL7A1) underlie EBD and in a dominant PEB family a glycine substitution mutation has been identified. We report a 33-year-old man affected by PEB showing abnormal AF and reduced immunostaining for type VII collagen. Mutation search in the COL7A1 gene revealed a 14 bp deletion in the 115 exon-intron boundary (33563del14), which resulted in the in-frame skipping of exon 115 with elimination of 29 amino acids from the pro-alpha1(VII) polypeptide chain. As a consequence, procollagen VII failed to be processed to mature collagen VII and accumulated at the dermal-epidermal junction, as revealed by immunofluorescence staining using a NC-2 domain-specific antibody. The proband's father was a clinically unaffected heterozygous carrier of mutation 33563del14, whereas the maternal pathogenetic mutation has still not been identified. This represents the first report of a recessive deletion mutation in PEB and extends the range of EBD phenotypes associated with mutation 33563del14.     

射频毁损治疗肝脏肿瘤

肝脏肿瘤包括肝原发性肿瘤和肝转移瘤,其治疗目前仍首选手术切除,但确诊时85％～95％的患者已失去手术切除时机,对难以手术治疗的患者已有多种介入治疗方法,如肝动脉栓塞化疗(TAE)、经皮无水酒精注射、微波、激光、冷冻、高功率超声聚焦等。射频毁损(radiofrequency ablation,RFA)是近年国外刚用于肝脏肿瘤治疗的新技术,具有安全性高、并发症少、患者易耐受、肿瘤复发可重复治疗等优点,具有良好的应用前景。 1 射频治疗仪及治疗机制 1868年法国的d'Arsonval发现高于10KHz的高变电流通过活体组织时,并不引起神经肌肉的应激,但局部产热造成组织毁损,自此射频毁损术在神经及心血管领域得以应用并     

The PCBP1 gene encoding poly(rc) binding protein i is recurrently mutated in Burkitt lymphoma

The genetic hallmark of Burkitt lymphoma is the translocation t(8;14)(q24;q32), or one of its light chain variants, resulting in IG‐MYC juxtaposition. However, these translocations alone are insufficient to drive lymphomagenesis, which requires additional genetic changes for malignant transformation. Recent studies of Burkitt lymphoma using next generation sequencing approaches have identified various recurrently mutated genes including ID3, TCF3, CCND3, and TP53. Here, by using similar approaches, we show that PCBP1 is a recurrently mutated gene in Burkitt lymphoma. By whole‐genome sequencing, we identified somatic mutations in PCBP1 in 3/17 (18%) Burkitt lymphomas. We confirmed the recurrence of PCBP1 mutations by Sanger sequencing in an independent validation cohort, finding mutations in 3/28 (11%) Burkitt lymphomas and in 6/16 (38%) Burkitt lymphoma cell lines. PCBP1 is an intron‐less gene encoding the 356 amino acid poly(rC) binding protein 1, which contains three K‐Homology (KH) domains and two nuclear localization signals. The mutations predominantly (10/12, 83%) affect the KH III domain, either by complete domain loss or amino acid changes. Thus, these changes are predicted to alter the various functions of PCBP1, including nuclear trafficking and pre‐mRNA splicing. Remarkably, all six primary Burkitt lymphomas with a PCBP1 mutation expressed MUM1/IRF4, which is otherwise detected in around 20–40% of Burkitt lymphomas. We conclude that PCBP1 mutations are recurrent in Burkitt lymphomas and might contribute, in cooperation with other mutations, to its pathogenesis. © 2015 Wiley Periodicals, Inc.