The surface modification of the silica-coated magnetic nanoparticles and their application in molecular diagnostics of virus infection.

The study presents a series of examples of magnetic nanoparticle systems designed for the diagnosis of viral diseases. In this interdisciplinary work, we describe one of the most comprehensive synthetic approaches for the preparation and functionalization of smart nanoparticle systems for rapid and effective RT-PCR diagnostics and isolation of viral RNA. Twelve different organic ligands and inorganic porous silica were used for surface functionalization of the Fe3O4 magnetic core to increase the number of active centres for efficient RNA binding from human swab samples. Different nanoparticle systems with common beads were characterized by HRTEM, SEM, FT-IR, XRD, XPS and magnetic measurements. We demonstrate the application of the fundamental models modified to fit the experimental zero-field cooling magnetization data. We discuss the influence of the nanoparticle shell parameters (morphology, thickness, ligands) on the overall magnetic performance of the systems. The prepared nanoparticles were tested for the isolation of viral RNA from tissue samples infected with hepatitis E virus-HEV and from biofluid samples of SARS-CoV-2 positive patients. The efficiency of RNA isolation was quantified by RT-qPCR method.

A 1D conical nanotubular TiO2/CdS heterostructure with superior photon-to-electron conversion.

Herein, a new strategy to efficiently harvest photons in solar cells is presented. A solar cell heterostructure is put forward, based on a 1D conical TiO2 nanotubular scaffold of high aspect ratio, homogenously coated with a thin few nm layer of CdS light absorber using atomic layer deposition (ALD). For the first time, a large variety of conical nanotube layers with a huge span of aspect ratios was utilized and ALD was used for the preparation of a uniform CdS coating within the entire high surface area of the TiO2 nanotubes. The resulting 1D conical CdS/TiO2 tubular heterostructure acts as a sink for photons. Due to the multiple light scattering and absorption events within this nanotubular sink, a large portion of photons (nearly 80%) is converted into electrons. It is the combination of the scaffold architecture and the light absorber present on the high surface area as a very thin layer, the optimized charge transport and multiple optical effects that make this heterostructure very promising for the next generation of highly performing solar cells.

CdS-coated TiO2 nanotube layers: downscaling tube diameter towards efficient heterostructured photoelectrochemical conversion.

Herein, a novel photoelectrochemical heterostructure based on TiO2 nanotube layers uniformly coated by a CdS thin layer (using ALD) is presented. Downscaling the nanotube diameter (from 95 to 35 nm) resulted in a 2-fold enhancement of the UV and Vis light photocurrents. Further photocurrent improvement resulted from the prior annealing of the TiO2 nanotube layers from 300 to 600 °C.

[Lung metastases as the first manifestations of occult medullary microcarcinoma]. / Metastázy do plic jako první projevy okultního medulárního mikrokarcinomu.

The article is concerned with medullary microcarcinoma of the thyroid. Similarly to medullary macrocarcinoma, this may metastasize to distant sites. Reported is a case of a 54year- old male who had suffered from chest tightness and dry irritating cough. Chest Xray showed small nodules with poorly- defined borders of unknown etiology. Lung biopsy was performed, which detected amyloid- rich neuroendocrine carcinoma. Examination of the thyroid was recommended to confirm or rule out suspected medullary carcinoma. The biopsy examination also suggested G1 and G2 primary neuroendocrine carcinoma of the lung or diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. Numerous examinations using imaging methods (CT, MRI, PET- CT) were carried out with no positive results in the thyroid. Despite that, thyroidectomy was performed. Subsequent biopsy examination revealed medullary microcarcinoma sized 0.6 cm. Apart from lung metastases, tumor lesions were found in cervical lymph nodes. This case is an example of a close cooperation between a pathologist and a clinician -  endocrinologist. Based on serum calcitonin levels, this may aid in differential diagnosis.

[Primary hepatic neuroendocrine carcinoma]. / Primární neuroendokrinní karcinom jater.

UNLABELLED: Primary neuroendocrine carcinoma of the liver is a rare tumour, probably arising from scattered neuroendocrine cells of the bile duct. We present the case of a 72-year-old male who experienced gradual weight loss and diarrhoea. Given the fact that he had stayed in the Dominican Republic, a parasitic disease was initially suspected. However, this was not confirmed. Further examination showed tumour infiltration of the liver. Fine needle aspiration cytology of the tumour site was performed. The diagnostic procedure revealed neuroendocrine carcinoma. The tumour cells expressed the following neuroendocrine markers (chromogranin, synaptophysin, CD56 and NSE) as well as the epithelial marker AE1-AE3. The tumour was considered metastasis of the primary tumour located in the gastrointestinal tract. A thorough clinical examination was performed including gastroscopy, colonoscopy, In-111 Octreoscan scintigraphy, computed tomography and magnetic resonance imaging. These methods revealed metastases in the vertebrae, pelvis, long bones and skull. No other tumour sites were found in the lungs, gastrointestinal tract or pancreas. The patient became increasingly cachexic and later died. An autopsy showed massive multicentric tumour infiltration of the liver. Histological examination revealed well differentiated neuroendocrine carcinoma which transformed into intermediate and small cells. The autopsy found no tumour sites in the gastrointestinal tract, lungs or pancreas. The results were suggestive of primary neuroendocrine carcinoma of the liver. KEYWORDS: neuroendocrine carcinoma - liver - primary tumour.

Coincidence of chronic lymphocytic leukaemia with Merkel cell carcinoma: deletion of the RB1 gene in both tumors.

The authors report a case of a 64-year-old man with chronic lymphocytic leukaemia (CLL) diagnosed 5 years ago. Recently, the patient was admitted with a tumour of the skin in the left lumbar region. Histological and immunohistochemical examinations established the diagnosis of Merkel cell carcinoma (MCC). Electron-microscopic examination revealed the formation of spherical aggregates of intermediate-sized filaments in the perinuclear region. The coincidence of MCC and CLl is rather rare and in published cases, no cytogenetic examinations were performed. We examined the RB1 gene using the interphase FISH method. A biallelic deletion in CLL tumour cells was detected; in MCC tumour cells, biallelic deletion was found in 33% of the cells and monoallelic deletion in 57% of the cells. In addition, chromosome 6 trisomy and 1p36 deletion were detected. Examination of non-neoplastic cells of the patient's skin showed a biallelic presence of the RB1 gene. According to the relevant literature, examination of the RB1 gene in CLL has informational value as a prognostic factor. The relationship between deletion of the RB1 gene and prognosis in MCC has not yet been determined and needs more research.

[Lymphoma of the small intestine]. / Lymfomy tenkého streva.

A series of eight small intestine lymphomas comprised two cases of follicular lymphoma (FL), one anaplastic large cell lymphoma (ALCL) ALK negative, and five cases of diffuse large B-cell lymphoma. The lymphomas were diagnosed by routine hematoxylin-eosin staining, immunohistochemistry and the FISH method for translocation t(14;18). Immunohistochemistry revealed that the diffuse large B-cell lymphomas were of the non-germinal center type (non GC-DLBCL). In most cases, the tumors formed solid well-circumscribed nodules or resulted in diffuse infiltration of the intestinal wall. In one case of follicular lymphoma, microscopic foci of tumor were found in the intestinal mucosa which spread far from the primary nodule and probably beyond the resection border. It is difficult to ascertain whether this phenomenon represents colonization of pre-existing non-neoplastic follicles by lymphoma or spreading of the tumor within the same tissue. In this case, surgical removal of the lymphoma is problematic.

Angiosarcoma of the parotid gland.

Angiosarcomas of the major salivary glands are rare tumours. The authors describe a case of the tumour located in the right parotid gland of a 77-year-old woman. Histological examination revealed a poorly differentiated tumour made up of epithelioid and spindle cells. These two types of cells intermingled. In some parts, primitive mutually anastomosing irregularly shaped vascular spaces with atypical endothelial cells were found. The tumour cells were positive for CD31, CD34, EMA and FVIII (focally). Due to the relatively short follow-up period the prognosis of the disease is difficult to estimate.

Complex analysis of cyclin D1 expression in mantle cell lymphoma: two cyclin D1-negative cases detected.

BACKGROUND AND AIM: The cytogenetic and diagnostic hallmark of mantle cell lymphoma (MCL) is translocation t(11;14)(q13;q32), resulting in overexpression of cyclin D1. Cyclin D1 expression was analysed in 32 cases of MCL. METHODS: The t(11;14) translocation was detected by fluorescence in situ hybridisation, level of cyclin D1 mRNA by competitive RT-PCR, and level of cyclin D1 and D2 proteins by immunohistochemistry and/or immunoblotting. RESULTS: In 30 cases, the presence of translocation t(11;14), a high level of cyclin D1 mRNA, and a high level of the cyclin D1 protein were confirmed. Two cyclin D1-negative cases overexpressing cyclin D2 were detected by immunoblotting. CONCLUSIONS: There are rare cyclin D1-negative cases of MCL overexpressing cyclin D2. Anti-cyclin D1 antibodies with low specificity can bind both cyclin D1 and cyclin D2, thus providing false cyclin D1-positive signals in immunohistochemical analysis.

[Localized tracheobronchial amyloidosis, type AA, and its differentiation from the systemic form of amyloidosis in clinical practice]. / Lokalizovaná tracheobronchiálni amyloidóza typu AA a její odliseni od systémové amyloidózy v praxi.

67-year-old patient with chronic obstructive pulmonary disease and chronic pansinusitis suffered from attacks of dyspnea, cough and common cold repeatedly. The chest X-ray was without clear pathology. Because of repeated difficulties, a bronchoscopic examination was made and a diagnosis of amyloidosis was made twice (bronchial biopsy, excision). The patient in our case suffered from a tracheobronchial form of amyloidosis (type AA most probably) together with chronic pansinusitis.

Electrochemical formation of self-organized anodic nanotube coating on Ti-28Zr-8Nb biomedical alloy surface.

In recent years, Ti-Zr-Nb alloys have become increasingly attractive as biomedical implant materials. In the present communication, we report the formation of self-organized nanotube oxide layers on a Ti-28Zr-8Nb biomedical alloy surface in 1M (NH4)2SO4 containing 0.25M NH4F. The morphology of the nanotube layers (the diameter and the length) is affected by the electrochemical conditions used (applied potential and time). Under specific conditions oxide layers consisting of highly ordered nanotubes with a wide range of diameters and lengths can be formed, varying, respectively, from approx. 50 to 300nm and from approx. 500nm to 22microm. The present results are highly promising for this biomedical alloy, as the large surface area and the tunable nanoscale geometry of the surface oxide provide novel pathways for the interaction of the materials with biorelevant species, such as cells and proteins.

Detailed mapping of chromosome 17p deletions reveals HIC1 as a novel tumor suppressor gene candidate telomeric to TP53 in diffuse large B-cell lymphoma.

Deletions in the short arm of chromosome 17 (17p) involving the tumor suppressor TP53 occur in up to 20% of diffuse large B-cell lymphomas (DLBCLs). Although inactivation of both alleles of a tumor suppressor gene is usually required for tumor development, the overlap between TP53 deletions and mutations is poorly understood in DLBCLs, suggesting the possible existence of additional tumor suppressor genes in 17p. Using a bacterial artificial chromosome (BAC) and Phage 1 artificial chromosome (PAC) contig, we here define a minimally deleted region in DLBCLs encompassing approximately 0.8 MB telomeric to the TP53 locus. This genomic region harbors the tumor suppressor Hypermethylated in Cancer 1 (HIC1). Methylation-specific PCR demonstrated hypermethylation of HIC1 exon 1a in a substantial subset of DLBCLs, which is accompanied by simultaneous HIC1 deletion of the second allele in 90% of cases. In contrast, HIC1 inactivation by hypermethylation was rarely encountered in DLBCLs without concomitant loss of the second allele. DLBCL patients with complete inactivation of both HIC1 and TP53 may be characterized by an even inferior clinical course than patients with inactivation of TP53 alone, suggesting a functional cooperation between these two proteins. These findings strongly imply HIC1 as a novel tumor suppressor in a subset of DLBCLs.

[Non-Hodgkin's lymphomas (from Rappaport to WHO 2001 and nowadays). Review]. / Ne-Hodgkinské lymfomy. (Od rappaporta po WHO 2001 a dnesek).

In the last decades, considerable changes in the classification of lymphomas have been made. In addition to morphology and immunohistochemistry, the last WHO (2001) classification also utilizes cytogenetics and molecular biology. In many cases classification notices oncogenic mechanisms. The authors describe some differences in immunophenotype in certain entities: chronic lymphocytic leukaemia/small lymphocytic lymphoma--CLL/SLL, follicular lymphoma--FL, mantle cell lymphoma--MCL, diffuse large B-cell lymphoma--DLBCL, and anaplastic large cell lymphoma--ALCL, mainly with respect to prognosis. The authors point out to heterogeneity within the individual types of lymphomas from the point of view of morphology, immunohistochemistry and molecular biology. Recently it has been shown, that differences in prognosis are not limited to individual nosologic entities, but also may be found within the particular category of lymphoma. For example, CLL/SLL is divided in two different subunits according to mutational status of variable segment (VH) of the immunoglobulin heavy chain gene. The cases with unmutated VH segment display progressive disease which is in contrast to cases with the same morphology but with mutated VH segment. Similar differences were found in MCL. Attention is drawn to oncogenic and apoptosis-regulating mechanisms, such as gene p53 and the Bcl-2 family.

Malignant fibrous histiocytoma of the parotid gland.

We described a rare malignant fibrous histiocytoma of the parotid gland (MFH) in a 63-year-old woman. During six months the tumour size became 10 cm in diameter with skin ulceration. The tumour was examined morphologically, by immunohistochemistry and molecular biology methods - FASAY and CGH. The histology revealed a storiform-pleomorphic type of MFH with high mitotic rate. The FASAY method identified a non-mutated p53 gene. The chromosomal changes were identified by the CGH method and 6 cytogenetic changes were found in the tumour cells (deletions at 8p12-p22, 13q32-qter, 14q24-qter, and gains of chromosomal material at 5p, 8q12-q23, and Xq25-qter). The patient died shortly after the beginning of chemotherapy. Autopsy revealed brain and cerebellar haemorrhage. No other tumour foci were proved. In view of short course of disease we lack the data about the influence of the non-mutated p53 gene on the prognosis and therapy.

[Melanoma simulating malignant soft tissue tumour]. / Melanom napodobující maligní nádor mekkých tkání.

The authors presented the case of an 82-year-old man with primary nodular melanoma of the skin on the back (Breslow 3 mm) which repeatedly metastasized five times to the cervical lymph nodes. Metastases were excised. The aim of this report was to demonstrate changes in the phenotype and immunophenotype during tumour progression. Originally round and oval melanoblasts had a characteristic immunophenotype. They were S100 protein, HMB45, Malan A, MITF positive. From the second biopsy the immunophenotype began to change, and the amount of positive cells declined. In the succeeding biopsies the morphology was also changed. There were spindle cells which formed mutually intermingled bundles in places with large multinucleate cells. The histological pattern assembled malignant mesenchymal tumour - type malignant fibrous histiocytoma. The immunophenotype was also changed. The second to fifth metastases in the cervical region were only S100 protein positive. The other above-mentioned melanoma markers were negative. Differential diagnosis includes neurotropic-desmoplastic malignant melanoma, Bednár tumour (pigmented dermatofibrosarcoma protuberans; storiform neurofibroma), malignant peripheral nerve sheath tumour (neurogenic sarcoma) and malignant fibrous histiocytoma.

[Immunohistological and molecular genetic findings in GIST of the stomach]. / Imunohistologické a molekulárne genetické nálezy u GIST zaludku.

The authors described immunohistological and molecular genetic findings in series of 21 tumours with spindle and epithelioid cells histology of the stomach. In 18 cases the tumours were KIT (CD117) positive and the diagnosis of gastrointestinal stromal tumour (GIST) was confirmed. Three cases were KIT (CD117) negative. According to additional immunohistological markers (desmin and smooth muscle actin positivity) two of them were categorized as leiomyomas. The immunohistological profile of the third case showed that the tumour could be classified as a transitional form between leiomyoma and GIST. All but one KIT (CD117) positive tumours were also CD34 positive. In other three KIT (CD117) positive cases up to 10% of CD34 positive cells were found. Desmin was negative in KIT (CD117) positive cases. S100 protein was positive in three KIT (CD117) positive cases ranging from single cells to 10% of cells. Nine tumours were NSE positive. In our study the connection between proliferation factors (Ki67 and PCNA) and the mitotic index was not established. Risk factors were identified based on the size of the tumours and the mitotic index. Very low and low risk of aggressive behaviour included 12 cases, intermediate risk category 5 cases, high risk category 4 cases. For molecular genetic examination, DNA was extracted from formalin-fixed, paraffin-embedded tissues. Exon 11 was analyzed by SSCP (single-strand conformational polymorphism analysis) with following sequencing. Deletion was found in 7 cases, point mutation in one case, silent point mutation in one case and in two cases the examination could not be detected. In 10 cases (47%) a "wild type" was found. We suggest that other exons, e.g. 9, 13, 17, (which were not examined) and genes than KIT gene could also trigger tyrosine-kinase activity.

[Adenoleiomyomatous hamartoma of the lung] ]. / Adenoleiomyomatózní hamartom plic.

The author described an adenoleiomyomatous hamartoma of the lung. The hamartoma was well circumscribed and measured 2.5 x 3.0 x 3.0 cm. This type of hamartoma is a rare lesion in literature described only in single cases, and without performed immunohistochemistry. In our case, the hamartoma was formed by slit or irregular glandular-like spaces lined by cuboid or columnar epithelial cells. Located around these spaces, fascicles and bundles of smooth muscle tissue with a positive antibody reaction to desmin, smooth muscle actin, and calponin, were found. Reaction with CD34 and S100 protein antibodies was negative. In the discussion, the author draws attention to disunity of terms and nomenclature of similar lesions. After three years of post-operative clinical follow-up, the patient is asymptomatic and without any signs of lung disorder.