Neuroimaging in Pineal Tumors

BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.     

Cytokine production, activation marker, and skin homing receptor in children with atopic dermatitis and bronchial asthma

T cells are known to develop a critical role in the pathogenesis of atopic dermatitis (AD) and bronchial asthma. T cells involved in AD express the skin homing receptor CLA, but no lung homing receptor has been identified in bronchial asthma. We compared different cell markers and the cytokine production in T cells from children with AD or bronchial asthma. We studied the involvement of CLA+ and CLA- T-cell subpopulations in these diseases. We studied 20 children with acute AD lesions, 15 with mild persistent asthma, and 15 non-atopic controls. All patients were sensitized to house dust mite (DP) and evaluated during the acute phase. Total and specific IgE were measured by immunoassay and the expression of different cell markers and the cytokine production was analyzed by flow cytometry in peripheral blood mononuclear cells. Total IgE was significantly higher in AD children and IgE to DP in the asthmatic children. There was a significant increase in CD25+ CD4+ cells in asthmatic children and in HLA-DR+ CD4+ and HLA-DR+ CD8+ cells in AD. In the CD4+ subsets, there was an increase in IL-13, IL-5 and TNF-alpha in AD compared to controls, a decrease in IFN-gamma in asthmatic children compared to controls, and an increase in IL-13, IL5, IL2, TNF-alpha, and IFN-gamma in the AD compared to asthmatic children. Changes in cytokine production were mainly detected in CLA+ cells in AD and in CLA- cells in asthma. Differences exist in total and specific IgE, activation markers, and cytokine patterns between AD children and children with asthma, with the former expressing a Th2 pattern whereas in asthmatic children we only detected a decrease in IFN-gamma. Moreover, the subpopulations (CLA+ vs. CLA-) expressing these changes were different, indicating that the underlying mechanisms in the two diseases are not exactly the same.     

Controlled administration of penicillin to patients with a positive history but negative skin and specific serum IgE tests

BACKGROUND: Although subjects with a positive history of immediate allergy to penicillin and negative skin test are traditionally considered to tolerate penicillin, current evidence indicates that they may develop an immediate reaction despite negative skin and serum specific IgE tests. It is thought that these patients require additional tests to confirm the diagnosis. OBJECTIVE: To assess in a large group of patients with a history of immediate allergy to penicillins but with both skin test and CAP-FEIA-negative to classical and side chain penicillin determinants, the role of controlled administration of betalactams as a diagnostic test. METHODS: A group of 330 patients with a history of immediate allergic reactions to penicillins was studied by two evaluators from the same allergy unit using the following protocol: skin tests with major and minor determinants of benzylpenicillin (benzylpenicilloyl-poly l-lysine and minor determinant mixture), amoxicillin and ampicillin, and determination of specific IgE antibodies to penicillins, by CAP-FEIA, in serum. If both tests proved negative, a controlled administration of the drug was then carried out. RESULTS: A total of 89 (27%) patients were skin test and CAP-FEIA-negative and therefore required controlled administration of the drug. Of these, 49 developed an immediate response and were therefore considered allergic, and the remainder had good tolerance after administration of both benzylpenicillin and amoxicillin. The clinical characteristics of this group were similar to the other allergic patients who were skin test or CAP-FEIA-positive, except that they were younger (P < 0.01). Twenty-two (45%) developed a response to benzylpenicillin and 27 (55%) had a selective response to amoxicillin. Although all reactions appeared within 1 h, a positive correlation was found between the dose inducing the response and the time elapsed from drug administration, for both benzylpenicillin and amoxicillin (P < 0.001). CONCLUSION: These data indicate that an important number of subjects are not correctly identified if only skin tests and/or CAP-FEIA are used and that this is particularly relevant for side chain-specific reactions and younger subjects. This suggests that new diagnostic tests are required so as to limit the use of controlled administration.     

Papillary (chromophil) renal cell carcinoma with mucinous secretion

We investigated the presence of mucin in a series of 20 papillary renal cell carcinomas. Acid mucin was present in three cases (15%), in which basophilic mucin secretion was evident with hematoxylin-eosin. This secretion reacted positively with Mayer's mucicarmine, Alcian blue and high-iron diamine, but was negative for PAS in all the cases, indicating the presence of sulphomucins. We describe two different types of mucin secretion: luminal and intracytoplasmic. The secretion was abundant, diffuse or extensive, luminal in two cases and intracellular in numerous scattered tumor cells in one case. All tumors were < 3 cm in diameter (low grade, stage I). In the three mucin-secreting papillary tumors mentioned above, the immunohistochemical and lectin studies indicate both a proximal and a distal tubular staining pattern. Mucinous secretion in these tumors can be ascribed either to modulation or direct metaplasia of the tumor epithelium. Mucin production, despite its low frequency, can be considered an additional feature of papillary renal cell carcinoma. Thus, the presence of luminal or intracytoplasmic mucin deposition does not exclude papillary renal cell carcinoma from the differential diagnosis in cases of intra- or extrarenal carcinomas.     

Immediate hypersensitivity to penicillins. Studies on Italian subjects

The IgE response, the involvement of the different penicillins available for therapeutic use, and the specificity of the IgE antibodies found in a group of penicillin-allergic subjects from Italy were studied. Thirty subjects with a history of allergic reactions to penicillins were studied. In vivo and in vitro specific IgE antibodies were determined to different penicillin determinants. Fifteen subjects developed anaphylactic responses and the remainder urticaria and angioedema. The drug most frequently involved in the patients' allergic reactions was ampicillin (AMP). The benzylpenicilloyl (BPO) skin test was positive in 16 (53.3%) patients, whereas 23 (76.6%) patients were positive to minor determinant mixture (MDM), benzylpenicillin (PG), AMP, or amoxicillin (AX). When classified according to initial reaction type, most anaphylactic patients (93.3%) were associated with minor determinant reactivity, whereas most urticaria patients (80%) reacted to BPO. RAST results for the anaphylactic and urticaria subgroups were similar. RAST inhibition showed that most sera contained highly cross-reactive IgE antibodies. There was evidence of a specific response to AX and PG (one patient each). These data show that in a population of penicillin-allergic patients from Italy, AMP was the main drug inducing the allergic reaction. In skin tests and RAST, patients exhibited heterogeneous IgE responses with little indication of specific reactivity to AMP.     

Nanoarchitectures for efficient IgE cross-linking on effector cells to study amoxicillin allergy

Background

Amoxicillin (AX) is nowadays the β-lactam that more frequently induces immediate allergic reactions. Nevertheless, diagnosis of AX allergy is occasionally challenging due to risky in vivo tests and non-optimal sensitivity of in vitro tests. AX requires protein haptenation to form multivalent conjugates with increased size to be immunogenic. Knowing adduct structural features for promoting effector cell activation would help to improve in vitro tests. We aimed to identify the optimal structural requirement in specific cellular degranulation to AX using well-precised nanoarchitectures of different lengths.

Method

We constructed eight Bidendron Antigens (BiAns) based on polyethylene glycol (PEG) linkers of different lengths (600–12,000 Da), end-coupled with polyamidoamine dendrons that were terminally multi-functionalized with amoxicilloyl (AXO). In vitro IgE recognition was studied by competitive radioallergosorbent test (RAST) and antibody–nanoarchitecture complexes by transmission electron microscopy (TEM). Their allergenic activity was evaluated using bone marrow-derived mast cells (MCs) passively sensitized with mouse monoclonal IgE against AX and humanized RBL-2H3 cells sensitized with polyclonal antibodies from sera of AX-allergic patients.

Results

All BiAns were recognized by AX-sIgE. Dose-dependent activation responses were observed in both cellular assays, only with longer structures, containing spacers in the range of PEG 6000–12,000 Da. Consistently, greater proportion of immunocomplexes and number of antibodies per complex for longer BiAns were visualized by TEM.

Conclusions

BiAns are valuable platforms to study the mechanism of effector cell activation. These nanomolecular tools have demonstrated the importance of the adduct size to promote effector cell activation in AX allergy, which will impact for improving in vitro diagnostics.

     

Comparison of nutritional and hydration status in patients undergoing twice and thrice-weekly hemodialysis: a silent drama in developing countries

International Urology and Nephrology - In low and middle- income countries, due to lack of financial resources, the number of patients receiving one or two hemodialysis (HD) sessions a week has...     

Expression and characterization of Gag protein of HIV-1（CN） in Pichia pastoris

To express the core protein of HIV-1 of Chinese prevalent strain （HIV-1 （CN）） in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA （1.3 kb） was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows： BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting.