A novel fungal prenyl diphosphate synthase in the dimorphic zygomycete Mucor circinelloides

Two Mucor circinelloides structural genes involved in isoprenoid biosynthesis were isolated and characterised. The isoA gene encodes a typical eukaryotic farnesyl diphosphate synthase (EC 2.5.1.10), whereas the isoB gene deduced amino acid sequence shows similarity to fungal medium-chain prenyl diphosphate synthases. By functional complementation in Escherichia coli, the isoB gene product was shown to be a solanesyl diphosphate synthase (EC 2.5.1.11), which is the first fungal enzyme reported having this specificity. In addition, a M. circinelloides one-marker-per-chromosome map was completed by contour-clamped homogeneous electric field localisation of isoA, isoB and three other isoprenoid biosynthesis genes to individual chromosomes.Abbreviations FPP farnesyl diphosphate (or pyrophosphate) - GGPP geranylgeranyl diphosphate - PrenylPP prenyl diphosphate - DPP decaprenyl diphosphate - HPP hexaprenyl diphosphate - SPP solanesyl diphosphate     

Morphological characteristics and immunophenotype of dendritic cells generated from monocytes of human peripheral blood

Morphological features and immunophenotype of mature dendritic cells (DC) generated from the monocytes of healthy donor blood after culture with GM-CSF and IL-4 with the addition of TNF, were studied using light and electron microscopy, as well as flow-cytometry. It was shown that DC were characterized by a number of morphological features such as: large size, eccentrically located nucleus, highly developed system of extensions, large vacuolated cytoplasm, prominent and activated Golgi complex and ribosomal apparatus. Mature DC are characterized by active surface expression of MHC and co-stimulatory molecules (MHC I, MHC II, CD40, CD80, CD86).     

Brucella lumazine synthase elicits a mixed Th1-Th2 immune response and reduces infection in mice challenged with Brucella abortus 544 independently of the adjuvant formulation used

The immunogenicity and protective efficacy of recombinant lumazine synthase from Brucella spp. (rBLS) administered with different adjuvants was evaluated in mice. Mice were immunized with rBLS in the absence or the presence of aluminum hydroxide gel (BLS-Al), monophosphoryl lipid A (BLS-MPA), or incomplete Freund's adjuvant (BLS-IFA). rBLS per se induced a vigorous immunoglobulin G (IgG) response, with high titers of IgG1 as well as IgG2. All the adjuvants increased this response; the BLS-IFA formulation was the most effective at inducing BLS-specific IgG antibodies. In addition, after in vitro stimulation with rBLS, spleen cells from BLS-IFA-, BLS-Al-, or BLS-MPA-immunized mice proliferated and produced interleukin-2 (IL-2), gamma interferon (IFN-gamma), IL-10, and IL-4, suggesting the induction of a mixed Th1-Th2 response. Immunization with rBLS protected mice against challenge with B. abortus 544. The levels of protection in the spleen were similar for all adjuvants, but only BLS-Al and BLS-IFA were effective in the liver. Our results indicate that BLS might be a useful candidate for the development of subunit vaccines against brucellosis, since it elicits antigen-specific cellular responses, with production of IFN-gamma and protection, independently of the adjuvant formulation used.     

Inflammatory Responses in Blood Samples of Human Immunodeficiency Virus-Infected Patients with Pulmonary Infections

We analyzed the characteristics of the inflammatory response occurring in blood during pulmonary infections in human immunodeficiency virus (HIV)-infected patients. A prospective study of consecutive hospital admissions of HIV-infected patients with new-onset radiologic pulmonary infiltrates was carried out in a tertiary university hospital from April 1998 to May 2001. Plasma cyclic AMP receptor protein (CRP), interleukin 1β (IL-1β), IL-6, IL-8, IL-10, and tumor necrosis factor alpha (TNF-α) levels were determined at the time of admission and 4, 5, and 6 days later. Patients were included in a protocol addressed to study etiology and outcome of disease. A total of 249 episodes of infection were included, with the main diagnoses being bacterial pneumonia (BP) (118 episodes), Pneumocystis carinii pneumonia (PCP) (41 episodes), and mycobacteriosis (36 episodes). For these three patient groups, at the time of admission the median CRP and cytokine levels were as follows: CRP, 10.2, 3.8 and 5 mg/dl, respectively (P = 0.0001); IL-8, 19, 3, and 2.9 pg/ml (P = 0.045); and TNF-α, 46.4, 44, and 75 pg/ml, respectively (P = 0.029). There were no significant differences in levels of IL-1β, IL-6, or IL-10 among the patient groups. A total of 23 patients died. At the time of admission, HIV-infected patients with BP had higher plasma CRP and IL-8 levels than did PCP and mycobacteriosis patients. TNF-α levels were higher in patients with mycobacteriosis. An elevated IL-8 level (>61 pg/ml) at the time of admission was an independent factor associated with higher mortality (odds ratio, 12; 95% confidence interval, 1.2 to 235.5).     

Preferential expression of T(h)2-type chemokine and its receptor in atopic dermatitis

Lesional skin of patients with atopic dermatitis (AD) is histologically characterized by hypertrophy of the skin, and the infiltration of a large number of eosinophils and T cells into the dermis. Recent studies have indicated that Th2 cells play a crucial role in the pathogenesis of AD skin. Chemokines and their receptors are implicated in the development of symptoms of various skin diseases such as AD and psoriasis vulgaris (psoriasis). We have examined the in situ expression of a typical Th2-type chemokine, thymus- and activation-regulated chemokine (TARC), and its receptor (CCR4) using immunohistochemical techniques. TARC was found to be highly expressed in the basal epidermis of the lesional skin of AD patients and only slightly in the non-lesional skin. On the other hand, no positive cells were seen in the lesional skin of psoriasis. Consistently, CCR4+ cells were present predominantly in the lesional skin of AD patients, but not in the non-lesional skin. In contrast, in the lesional skin of psoriasis patients, cells positive for CCR5, which is expressed on Th1 cells, were abundantly present. Interestingly, psoralen plus ultraviolet A therapy reduced the number of CCR4+ cells in the AD skin lesions. These results suggest that Th2-type cytokines such as TARC are involved in the pathogenesis of skin lesions in AD patients through the preferential recruitment of Th2 cells.     

Ultrastructural tissue-specific signs of the cells of cancerous tumors of the human breast

Ultrastructural analysis of mammary carcinoma (45 cases) and its metastasis in the lymph nodes (21 cases) revealed the tissue specific features of the mammary gland: big ducts and intercellular canaliculi, microvilli, various specialized cell-to-cell contacts, basal membrane. Tissue specific features are not associated with a certain organ. In mammary carcinoma, they are more pronounced in carcinomas in situ, invasive tumours of the 1st grade of malignancy (adenocarcinoma) and specific histologic variants. They are less pronounced in solid and scirrhous invasive tumours of the 2nd and especially 3rd grade of malignancy. However it is impossible to conclude about the anaplasia degree on the basis of the number of and the correlation between various tissue specific features. Metastasis retains the capacity of cancer cells to form the tissue specific ultrastructural elements. The tissue specific properties of mammary carcinoma determine the diagnosis in cases when the question on the tissue origin of the tumour is to be solved.     

Results of the electron microscopic diagnosis of human tumors (an analysis of 1000 cases)

A review of electron-microscopic diagnostic investigations made on biopsy specimens from 1000 patients showed the range of tumors requiring ultrastructural diagnosis to be fairly broad, encompassing virtually all major tumor sources including soft tissues (37% of the cases), epithelium (31.8%), hematopoietic organs (21.3%), pigment-forming tissues (4.9%), and bones (3.3%). The tissue and cellular origin of the tumor was identified, i.e. a differential diagnosis was correctly made and/or the histogenetic (cytogenetic) type of the tumor was established, in most (83.0%) of the cases, whereas the organ of tumor origin was identified in only 6.0%. Electron-microscopically, the histological diagnosis was confirmed in 45.3% of the cases, made more precise in 19.0%, and discarded in 5.1%; in 5.8%, electron microscopy confirmed as correct one of the diagnoses presumed on histologic grounds, while in 3.9% the diagnosis could not be verified because the tumors consisted of undifferentiated cells in their entirety. Historic material (formalin-fixed or from paraffin blocks) and stained histologic sections were used for the ultrastructural diagnoses.     

A complex composed of USF1 and USF2 activates the human FcepsilonRI alpha chain expression via a CAGCTG element in the first intron

The high-affinity IgE receptor, FcepsilonRI, is a key regulatory molecule in the allergic reaction. During the course of studies to find cis-acting elements for FcepsilonRI alpha chain gene expression, a CAGCTG sequence located in the first intron was revealed to serve as a crucial enhancer element. Electromobility shift assays using antibodies and in vitro translation products showed that the CAGCTG element was recognized by the USF1/USF2 complex. As was the case for other intronic cis-elements, the CAGCTG element regulated the promoter in an orientation- and position-dependent manner. Overexpression of USF2 antisense repressed the FcepsilonRI alpha chain gene promoter and decreased the amount of alpha chain mRNA in mast cell lines. All these results indicated that the USF1/USF2 complex activates the human FcepsilonRI alpha chain gene expression via the CAGCTG element in the first intron.     

Does there exist an obesity paradox in COVID-19? Insights of the international HOPE-COVID-19-registry

BackgroundObesity has been described as a protective factor in cardiovascular and other diseases being expressed as ‘obesity paradox’. However, the impact of obesity on clinical outcomes including mortality in COVID-19 has been poorly systematically investigated until now. We aimed to compare clinical outcomes among COVID-19 patients divided into three groups according to the body mass index (BMI).MethodsWe retrospectively collected data up to May 31^st, 2020. 3635 patients were divided into three groups of BMI (<25 kg/m²; n = 1110, 25?30 kg/m²; n = 1464, and >30 kg/m²; n = 1061). Demographic, in-hospital complications, and predictors for mortality, respiratory insufficiency, and sepsis were analyzed.ResultsThe rate of respiratory insufficiency was more recorded in BMI 25?30 kg/m² as compared to BMI < 25 kg/m² (22.8% vs. 41.8%; p < 0.001), and in BMI > 30 kg/m² than BMI < 25 kg/m², respectively (22.8% vs. 35.4%; p < 0.001). Sepsis was more observed in BMI 25?30 kg/m² and BMI > 30 kg/m² as compared to BMI < 25 kg/m², respectively (25.1% vs. 42.5%; p = 0.02) and (25.1% vs. 32.5%; p = 0.006). The mortality rate was higher in BMI 25?30 kg/m² and BMI > 30 kg/m² as compared to BMI < 25 kg/m², respectively (27.2% vs. 39.2%; p = 0.31) (27.2% vs. 33.5%; p = 0.004). In the Cox multivariate analysis for mortality, BMI < 25 kg/m² and BMI > 30 kg/m² did not impact the mortality rate (HR 1.15, 95% CI: 0.889?1.508; p = 0.27) (HR 1.15, 95% CI: 0.893?1.479; p = 0.27). In multivariate logistic regression analyses for respiratory insufficiency and sepsis, BMI < 25 kg/m² is determined as an independent predictor for reduction of respiratory insufficiency (OR 0.73, 95% CI: 0.538?1.004; p = 0.05).ConclusionsHOPE COVID-19-Registry revealed no evidence of obesity paradox in patients with COVID-19. However, Obesity was associated with a higher rate of respiratory insufficiency and sepsis but was not determined as an independent predictor for a high mortality.