Role of membrane N-linked oligosaccharides in host cell interaction with invasive forms of Trypanosoma cruzi

The removal of N-linked oligosaccharides by peptide-N4-[N-acetyl-beta-glucoseaminyl]asparagine amidase (previously known as aspartoglycosylamine amidohydrolase and abbreviated N-glycanase) from the surface of blood or insect-transmissible forms of Trypanosoma cruzi markedly increased the capacity of these organisms to associate with (i.e., bind and penetrate) either mouse peritoneal macrophages or rat heart myoblasts. This effect was evidenced by a significant elevation in both the percentage of infected host cells and the average number of parasites per 100 cells. Conversely, N-glycanase treatment of either host cell markedly reduced both parameters to levels significantly below those obtained with cells mock treated with medium alone. The N-glycanase effect on the parasites was inhibited by heat inactivation of the enzyme or by the presence of fetuin, an N-glycanase substrate. The enhanced capacity of N-glycanase-treated T. cruzi to engage the host cells started to subside 2 h after the treatment, indicating the reversibility of the effect. The decreased reactivity of N-glycanase-treated macrophages or myoblasts with T. cruzi suggests that N-linked oligosaccharides on these host cells are involved in the initial phase of the cell infection process. Instead, because T. cruzi interacted more effectively with host cells after treatment with N-glycanase, parasite surface N-linked oligosaccharides would seem to interfere with the association.     

霍奇金病继发皮肤病变伴EBV编码的潜伏膜蛋白染色阳性1例报道

霍奇金病皮肤受累在H IV阳性患者少见。尽管这些病例中大多数的发病机制与Epstein-Barr病毒(EBV)相关,但很少有研究来证实霍奇金病皮肤受累的病毒致癌基因。作者报道1例H IV阳性男性患者,伴有侵袭性霍奇金病和特殊皮肤受累。皮损和淋巴结取样发现对EBV编码的潜伏膜蛋白呈阳性反     

Analysis of polyadenylated RNA from human heart mitochondria

Summary The content of the mitochondrial poly(A)-RNA fraction of human heart has been analyzed by electrophoresis through agarose slab gels in the presence of methyl mercury hydroxide and staining with ethidium bromide. It is possible to identify all the heavy strand coded mRNAs in the electrophoretic pattern. This pattern is qualitatively similar to that obtained from the mitochondria of cells cultured in vitro (HeLa cells), although differences in the relative amount of some components have been detected.     

Bee moth (Galleria mellonella) allergic reactions are caused by several thermolabile antigens

BACKGROUND: Exposure and contact with bee moth (Galleria mellonella) larvae (Gm) can cause an allergic reaction both in anglers and breeders. We described the case of an amateur fisherman who experienced an allergic reaction using Gm but not using heat-treated Gm (h-Gm) (mummies). The aim of this study was to demonstrate by immunoblotting and radioallergosorbent test (RAST)-inhibition experiments the loss of allergenic epitopes in h-Gm extracts. METHODS: Galleria mellonella larvae and h-Gm were homogenized and extracted at 10% (w/v) in 0.5 M phosphate-buffered saline, pH 7.4 containing 0.5% NaN(3) for 16 h at 4 degrees C. Gm and h-Gm extracts were electrophoresed in a 10% polyacrylamide precast Nupage Bis-Tris gel at 180 mA for 1 h and the resolved proteins stained with 0.1% Coomassie brilliant blue and the molecular weight calculated. For the immunoblotting detection of allergenic components the resolved extracts were transferred onto a nitrocellulose membrane and incubated with the patient's serum. Bound specific-IgE was detected by peroxidase-conjugated anti-human IgE. RAST inhibition experiments were performed according to the Ceska method. RESULTS: The protein profile of Gm and h-Gm extracts resulted markedly different in number, intensity and the position of bands, indicating that heat-treatment modifies the chemical-physical characteristics of the protein contents. The Gm extract showed a strong-coloured band at 73 kDa and more than 20 components ranging from 12 to 133 kDa; h-Gm showed two main band at 77 and 38 kDa and about 15 faint bands between 20 and 133 kDa apparently without any correspondence to the bands present in the Gm extract. Immunoblotting with the patient's serum demonstrated several bands of reactivity with the Gm extract ranging from 20 to 100 kDa and no recognizable bands, but only a diffuse smear with h-Gm. When used in a RAST inhibition experiment the h-Gm extract demonstrated an inability to compete with the Gm one for the binding to patient's IgE serum. CONCLUSIONS: The h-Gm seems to lose the allergenic epitopes and has two advantages for anglers: to avoid new possible sensitizations as well as allergic symptoms in sensitized people, without interfering with their skills and satisfaction in their fishing performance.     

Spontaneous retroperitoneal hematoma: our experience

We report 15 cases of spontaneous retroperitoneal haematoma. The etiology and the diagnostic and therapeutic procedures were evaluated. The haematoma source was the adrenal gland in 4 patients and the causes were pheochromocytoma (1), adenoma (1), myelolipoma (1) and idiopathic (1). In 10 patients the source was the kidney and the causes were angiomyolipoma rupture (6), renal cell carcinoma (3) and ureteral calculi (1). In the remaining case, the haematoma was produced by fibrinolytic and anticoagulant therapy in a patient with acute myocardial infarction. The imaging diagnostic techniques employed were abdominal ultrasonography and CT scan, which allowed the diagnosis of haematoma and showed his size and extension in all the cases. With these two techniques, and with the retrograde pyelography in one patient, we obtained the etiologic diagnosis in 12 of the 15 cases. Surgical treatment was performed in 12 patients (adrenalectomy in 2, simple nephrectomy in 3, radical nephrectomy in 5 and partial nephrectomy in 2).     

Analytical and diagnostic accuracy of "second generation" assays for thyrotrophin receptor antibodies with radioactive and chemiluminescent tracers

AIMS: To investigate the analytical and diagnostic accuracy of thyrotrophin (TSH) receptor antibody assays using recombinant human TSH receptors. METHODS: Sera from 68 patients with Graves' disease, 23 patients with autoimmune thyroiditis, and 119 healthy controls were evaluated in four different laboratories using both radioactive and chemiluminescent tracers. Functional sensitivity, interlaboratory precision, optimal cutoff values for Graves' disease, and the correlation between the two methods were evaluated. RESULTS: Functional sensitivity was 0.98 IU/litre for both assays. Interlaboratory precision, expressed as per cent coefficient of variation over a wide range of antibody concentrations, varied from 5.7% to 15.1% for the radioligand, and from 6.6% to 19.9% for the chemiluminescence assay. The two methods (radioactive and chemiluminescent) were closely correlated. All the sera from untreated or relapsing patients with Graves' disease gave TSH receptor antibody values above 2.1 IU/litre, whereas in none of the healthy controls did values exceed 2.5 IU/litre. Receiver operating curve analysis allowed an optimal cutoff point to be defined at 1.99 IU/litre, according to a sensitivity of 100% and specificity of 99.1%. CONCLUSIONS: These data show the high analytical and diagnostic accuracy of the human TSH receptor assays, both with radioactive and chemiluminescent tracers, when both functional sensitivity and interlaboratory reproducibility are considered. These two methods could be proposed as first line diagnostic markers for Graves' disease.     

Phagocytosis of the three developmental forms of Trypanosoma cruzi: effect of specific sera

Studies were carried out aiming at comparing the uptake of the three evolutionary stages of Trypanosoma cruzi by mouse peritoneal macrophages, influenced by specific immunosera. Incorporation of T. cruzi by macrophages was time dependent. In absence of antibody, trypomastigotes are forms more effectively incorporated by macrophages. Pre-incubation of macrophages with specific sera against each of the T. cruzi morphological stages was followed by an increase in the uptake of amastigotes and trypomastigotes but not of epimastigotes. Our results show that amastigotes, in comparison with the other T. cruzi forms are more actively phagocytized in presence of specific serum.     

Differential Reactivity to IMPDH2 by Anti-rods/rings Autoantibodies and Unresponsiveness to Pegylated Interferon-alpha/Ribavirin Therapy in US and Italian HCV Patients

Purpose

Autoantibodies to cytoplasmic structures called rods and rings (RR) are primarily specific to patients with hepatitis C virus (HCV) infection treated with pegylated interferon-alpha/ribavirin (IFN/R). Our aim is to examine anti-RR antibodies specificity and correlation with the response to IFN/R therapy in two independent cohorts (US and Italy) of HCV patients.

Methods

Sera from the US cohort (n?=?47) and the Italian cohort (n?=?46) pre-selected for anti-RR antibodies were analyzed by immunofluorescence and radioimmunoprecipitation. The prevalence and titers of anti-RR were analyzed for correlation with the response to IFN/R therapy.

Results

In the US cohort, anti-RR antibodies were more frequently non-responders to IFN/R (71 % vs 29 % responders). Titers in responder patients (n?=?11) were ≤1:3200, whereas titers in non-responder patients (n?=?27) reached 1:819,200 (p?=?0.0016). In the Italian cohort, anti-RR titers ranged from 1:200 to >1:819,200 and only relapsers had the highest anti-RR titers. Radioimmunoprecipitation demonstrated that anti-RR autoantibodies were mainly anti-inosine monophosphate dehydrogenase 2 (IMPDH2) - 96 % in the Italian cohort vs. 53 % in the US cohort.

Conclusions

In the two cohorts analyzed, the anti-IMPDH2 response as a component of the anti-RR response is much more prominent in the Italian cohort. The reason for the difference between the US and Italian cohorts is unclear but it possibly illustrates the heterogeneity in response and the overall negative correlation between the production of these autoantibodies and response to IFN/R therapy. Patients with high titer anti-RR antibodies are either relapsers (Italian) or non-responders/relapsers (US).