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PubMed1978

Epidemiology of poly-parasitism. III. Effects on the diagnostic capacity of immunological tests.

The paper describes some effects of interaction between different types of parasitic infections on the diagnostic capacity of immunological tests for parasitic diseases. Examples shown include an analysis of association for anergy to tuberculin in skin tests of individuals with and without skin manifestations of onchocerciasis; skin tests with P. westermani and C. sinensis antigens to detect double infections in patients harbouring both trematodes; geographical evaluation of the sensitivity of the complement fixation (CF) test for schistosomiasis with S. mansoni antigen between different communities in Chad; reduced sensitivity of the CF test for schistosomiasis in patients with confirmed schistosomiasis who have also onchocerciasis; studies on the specificity of the slide flocculation (SF) test for schistosomiasis in relation to specified intestinal parasites and to the presence of antibodies to E. granulosus and T. spiralis in villages of Afghanistan; and a study of association between poly-parasitism and anticomplementary activity in the sera of population samples from the African Savannah. The combined investigations indicate that there are large dissimilarities in test performance between communities with different disease spectra and nutritional status. The findings suggest that polyparasitism interferes with immunodiagnostic tests both directly through cross-reactions with antigens and antibodies and indirectly through its effects on nutrition and on mechanisms affecting the complement system. Large scale screening for parasitic diseases with immunodiagnostic tests in areas in which the medical problems are not well-known should be prededed by a small, well-planned pilot study in which the relative sensitivity and specificity of the test can be determined before its use in extensive population studies.

Afghanistan↗
PubMed1982

Interpreting serologic tests for syphilis.

Since syphilis is most often diagnosed by serologic studies, the correct interpretation of these tests is critical. Serologic tests are classified as nontreponemal of treponemal, according to the antigen employed. Flocculation tests are generally used for routine screening because of their simplicity. The treponemal procedures are more specific, but false-positive results may still occur. Results vary with the procedure, stage of disease and treatment. Significant difficulties remain with the serologic diagnosis of neurosyphilis and congenital syphilis.

Complement Fixation Tests↗
PubMed1982

[Experiences in serological diagnosis of tuberculosis].

Serological tests complete clinical diagnosis of tuberculosis. Passive hemagglutination and passive hemolysis are of greater usefulness than complement fixation, precipitations, flocculation or agglutination reactions. Antiglobulin technique and combination of several tests are of value. False negative results in cases of tuberculosis and healthy persons serologically false positive are still a problem. New tests with standardized purified polysaccharide, phosphatide and protein are expected to be of value in future.

Agglutination Tests↗
PubMed1981

[A two-stage technique for concentration of viruses from solutions with low virus titers (e.g., drinking water)].

The evidence of viruses in drinking water is an important component of studies of viruscirculation between man and his environment. In the two-stage concentration technique presented in this paper the method of aluminium sulphat flocculation, verified in more than 1300 investigations, is the first stage. In the second stage, aluminium hydroxide gel is at first dissolved with 1 ml of citric acid sodium citrate buffer at pH 4,7. The physico-chemical aspects of the lysis are discussed. It is from the lysate, that is not toxic for viruses, that viruses are separated by ultracentrifugation and inoculated on cell cultures. Owing to considerable constriction effect of about 20 000:1 is the method especially suitable for evidence of viruses in solutions with low virus titers (e.g. drinking water) as confirmed by a series of tests.

Aluminum Hydroxide↗
PubMed1975

[Value of TPHA in the serological screening of lues].

In the present work, 21,400 not selected sera were tested with hemagglutination test (TPHA) and flocculation test (VDRL) with cardiolipin for screening of syphilis; sera that gave negative results against both tests showed remarkable agreement (97,81%). 468 sera gave positive results to least one of the tests employed in screening and were tested with the following procedures: fluorescent Treponemal antibody-absorption (FTA/ABS) test, complement fixation (by Kolmer, modified) with proteic (KP) and lipidic (KL) antigen; 100 of these sera were also tested with T. pallidum immobilizaiton (TPI) test. The agreement among the before mentioned tests and sera that gave positive results only to VDRL was significatively low; on the contrary, the agreement was remarkable in the case of those positive only to TPHA (99% with FTA/ABS, 83% with TPI, 52,5% with KP and 21,5% with KL). The results obtained in attesting sensitivity and specificity of TPHA indicate that it is a very valuable screening test, and suggest to the AA. to emphasize that TPHA/VDRL association a definitive conclusion in syphilis serological negativity.

Antibody Formation↗
PubMed1993

Comparison of glass wool and glass powder methods for concentration of viruses from treated waste waters.

Enumeration of cultivable virus particle in sewage requires the samples to be concentrated. Two adsorption-elution methods, the glass wool cartridge method and the glass powder fluid layer method were compared. Firstly, it was demonstrated that virus could be readily recovered from the head, first 25 ml, of eluate of glass wool rather than from a reconcentration of the entire eluate, either by organic flocculation: 83% of positivity vs 44% respectively or double precipitation by PEG: 85% of positivity vs 61% respectively. Concentration on glass wool allowed the rescue of a greater number of positive samples (33/35) than on glass powder (16/35) as well as a higher mean titer of indigenous viruses, respectively 19 MPNCU/l vs 6 MPNCU/l (F1(34) = 36.02, P < 0.0001). Enteroviruses were the most frequently isolated viruses: found in 34/35 samples by either method, in 32/35 samples by glass wool, and in 14/35 samples by glass powder. Of the 12 enterovirus types identified by either method, a majority was Echovirus 6 (10 samples), Echovirus 11 (7 samples), Coxsackievirus B5 (4 samples) and also Coxsackievirus A7, A16, A21, B1, B6, Echovirus 1, 4, 12 and 19. Adenovirus types 1 and 5 were isolated from 4 samples by either method.

Adsorption↗
PubMed1995

A study of growth kinetics of the flocs from Schizosaccharomyces pombe.

Inducing yeast cells to self-flocculate could be considered a cell immobilization method. The growth kinetics of the flocs from Schizosaccharomyces pombe was studied in an experimental suspended-bed bioreactor with starch hydrolysate obtained by two-stage enzymatic hydrolysis. It was discovered that a limited oxygen supply was necessary during continuous ethanol fermentation with yeast flocs. The oxygen supplied was a kind of limited substrate effecting on the floc growth. Further, a kinetic model describing this floc growth was proposed.

Cell Division↗
PubMed1997

Expression and potential role of the extracellular matrix in hepatic ontogenesis: a review.

Studies from a number of laboratories have provided information on the temporal and spatial expression of a variety of extracellular matrix (ECM) components in the developing liver and insight into their potential roles in hepatogenesis. Collagen type IV and laminin are present in the basement membranes of the capsular mesothelium, vascular structures of the portal and hepatic vein branches, and the ductular elements of the developing liver. The mesothelial, vascular, and ductular epithelial cells synthesize laminin and type IV collagen. In contrast, fibronectin and type I collagen are restricted to the adjacent or surrounding interstitium of those ductal and vascular elements, but are not within the basement membrane proper. The hepatic perisinusoidal space (Space of Disse) of the fetal rat develops a delicate extracellular matrix by 12.5 days of gestation, which is characterized by banded collagen fibrils and bundles associated with filamentous and flocculent material. Fibronectin, laminin, and collagen types I, III, and IV are present in the developing perisinusoidal space by this early gestational date, with laminin being the most prevalent component detected. The laminin chains localized to that region in the fetal/neonatal period are alpha 2, beta 1, beta 2, and gamma 1, whereas the alpha 1 chain of laminin is absent from the developing Space of Disse. Similar data have been reported on the laminin phenotype in the perisinusoidal space during hepatic regeneration. Electron microscopy immunohistochemistry studies have demonstrated that the sinusoidal lining cells and hepatocytes synthesize these ECM proteins during hepatogenesis. By 6 to 8 weeks of postnatal life, laminin is not detectable in the perisinusoidal space. Both the transient expression of laminin and the similarity of the laminin chain phenotype expressed in the perisinusoidal space in the developing and regenerating liver suggests a role for this protein in the organization of the hepatic lobule in those forms of hepatic morphogenesis.

Animals↗
PubMed1996

A rapid and selective assay for measuring cell surface hydrophobicity of brewer's yeast cells.

A rapid and selective assay was developed to measure cell surface hydrophobicity of brewer's yeast cells. During this so-called magnobead assay, bottom-fermenting yeast cells adhere to paramagnetic, polystyrene-coated latex beads which can easily be removed from the cell suspension by using a (samarium-cobalt) magnet. At pH 4 center dot 5, electrostatic repulsion between yeast cells and latex beads was found to be minimal and yeast cell adhesion was predominantly based on hydrophobic interactions. The percentage of cells adhering to the beads could be calculated and provided a measure for cell surface hydrophobicity. Cell surface hydrophobicity measured by the magnobead assay was found to yield similar results, as did determination of contact angles of water droplets on a layer of yeast cells, a standard method for measuring surface hydrophobicity. However, the magnobead assay has the following advantages: (i) it is a quick and simple method, and, more significantly, (ii) hydrophobicity can be measured under physiological conditions. Use of the magnobead assay confirmed that a higher level of cell surface hydrophobicity is correlated with stronger flocculence of brewer's lager yeast cells.

Adhesiveness↗
PubMed1997

Sequence analysis of a 37.6 kbp cosmid clone from the right arm of Saccharomyces cerevisiae chromosome XII, carrying YAP3, HOG1, SNR6, tRNA-Arg3 and 23 new open reading frames, among which several homologies to proteins involved in cell division control and to mammalian growth factors and other animal proteins are found.

The nucleotide sequence of 37,639 bp of the right arm of chromosome XII has been determined. Twenty-five open reading frames (ORFs) longer than 300 bp were detected, two of which extend into the flanking cosmids. Only two (L2931 and L2961) of the 25 ORFs correspond to previously sequenced genes (HOG1 and YAP3, respectively). Another ORF is distinct from YAP3 but shows pronounced similarity to it. About half of the remaining ORFs show similarity to other genes or display characteristic protein signatures. In particular, ORF L2952 has striking homology with the probable cell cycle control protein crn of Drosophila melanogaster. L2949 has significant similarity to the human ZFM1 (related to a potential suppressor oncogene) and mouse CW17R genes, though it lacks the carboxy-terminal oligoproline and oligoglutamine stretches encoded by these mammalian genes. The small ORF L2922 is similar to part of the much larger yeast flocculation gene FLO1. Other sequences found in the 37639 bp fragment are one delta and one solo-sigma element, the tRNA-Arg3 gene, the small nuclear RNA gene SNR6 and three ARS consensus sequences.

Amino Acid Sequence↗
PubMed1999

Saccharomyces cerevisiae IRR1 protein is indirectly involved in colony formation.

The ability of a microorganism to adhere to a solid support and to initiate a colony is often the first stage of microbial infections. To date, studies on S. cerevisiae cell-cell and cell-solid support interactions concerned only cell agglutination during mating and flocculation. Colony formation has not been studied before probably because this species is not pathogenic. However, S. cerevisiae can be a convenient model to study this process, thanks to well-developed genetics and the full knowledge of its nucleotide sequence. A preliminary characterization of the recently cloned essential IRR1 gene indicated that it may participate in cell-cell/substrate interactions. Here we show that lowering the level of expression of IRR1 (after fusion with a regulatory catalase A gene promoter) affects colony formation and disturbs zygote formation and spore germination. All these processes involve cell-cell or cell-solid support contacts. The IRR1 protein is localized in the cytosol as verified by immunofluorescence microscopy, and confirmed by cell fractionation and Western blotting. This indicates that Irr1p is not directly involved in the cell-solid support adhesion, but may be an element of a communication pathway between the cell and its surroundings.

Blotting, Western↗
PubMed1997

Fine-needle aspiration of chromophobe renal cell carcinoma. Analysis of six cases.

BACKGROUND: The chromophobe variant of renal cell carcinoma is a recently described and frequently unrecognized tumor. Because the prognosis of the chromophobe variant appears to be intermediate between that of oncocytoma and the clear cell variant of renal cell carcinoma, accurate diagnosis may be important for appropriate clinical management. METHODS: A retrospective analysis of fine-needle aspirations of four primary and two metastatic chromophobe renal cell carcinomas (five typical and one eosinophilic variant) with histologically confirmed primary tumors was performed. Hale's colloidal iron stain was strongly positive in a diffuse cytoplasmic pattern in all resected primary tumors. RESULTS: All fine-needle aspirations were characterized by cellular smears comprised of single cells and small groups of cells. The cytoplasm varied from granular to flocculent. A characteristic feature was the presence of occasional markedly enlarged, bizarre, often multinucleated cells, within a background of moderately atypical cells. Nuclear enlargement, hyperchromasia, pleomorphism, and outline irregularity were noted in all cases. These features imparted a koilocyte-like appearance to many of the cells. Intranuclear pseudoinclusions were present in four cases and were numerous in two. CONCLUSIONS: Both primary and metastatic chromophobe renal cell carcinomas have unique cytologic features that allow for their distinction from oncocytoma and other variants of renal cell carcinoma.

Adenoma, Oxyphilic↗
PubMed1999

Fine-needle aspiration biopsy of chromophobe renal cell carcinoma and oncocytoma: comparison of cytomorphologic features.

BACKGROUND: Chromophobe renal cell carcinoma (ChRCC) is a distinct tumor with a prognosis intermediate between renal oncocytoma (RO) and clear cell renal cell carcinoma. To our knowledge the cytologic features of only a limited number of ChRCC have been described to date. A retrospective review of the cytomorphologic features of ChRCC and a comparison with RO was performed. METHODS: Fine-needle aspiration biopsies (FNABs) of six cases of histopathologically proven ChRCC were reviewed. The material examined was comprised of smears, cytospins, Thin Prep Pap Test preparations, and cell block sections stained with Diff-Quik, Papanicolaou, and hematoxylin and eosin. Six FNABs of ROs were examined similarly. The cytomorphology of each tumor was studied and particular attention was paid to features differentiating the two entities. RESULTS: The characteristic cytomorphologic features of ChRCC (present in all cases) included round/oval, occasionally polygonal, moderately pleomorphic large cells present singly and in small clusters. The abundant cytoplasm was variegated, ranging from dense to flocculent to vacuolated, with prominent cytoplasmic membranes. The nuclei were large and hyperchromatic, with nuclear membrane irregularities and grooves present at least focally. Frequent binucleation was observed. Small nucleoli were present in many cells, but rarely prominent. In contrast, RO showed large cells with homogenous granular cytoplasm. The nuclei showed minimal to no nuclear membrane irregularities, tiny nucleoli, mild pleomorphism, and only an occasional large, more hyperchromatic nucleus was observed. CONCLUSIONS: ChRCC has a distinct combination of cytomorphologic features. Careful attention to cytoplasmic and nuclear features allows for the distinction between ChRCC and RO in cytologic preparations.

Adenoma, Oxyphilic↗
PubMed1996

Mouse Meckel's cartilage chondrocytes evoke bone-like matrix and further transform into osteocyte-like cells in culture.

BACKGROUND: We reported that when Meckel's cartilage was transplanted ectopically, chondrocytes transformed into osteocyte-like cells accompanying the extracellular calcified matrix. However, we could not determine whether the osteocyte-like cells were derived from host tissues or from Meckel's cartilage itself. Therefore, we examined whether the Meckel's cartilage chondrocytes, which have a retrogressive ultimate fate, are capable of inducing the observed calcification and further transform into osteocyte-like cells in culture. METHODS: Meckelian chondrocytes isolated enzymatically were plated at a low density and grown in alpha-MEM containing 10% FBS at 37 degrees C under 5% CO2 in air for up to 4 weeks. RESULTS: Chondrocytes were fibroblast-like cells early in culture, but gradually transformed from polygonal cells into typical chondrocytes showing metachromasia with toluidine blue staining. After an additional week of culture, the chondrocytes transformed from large to small round cells accompanying nodule formations. Small round cells multiple-layered actively, and showed more intense alkaline phosphatase (ALPase) activity. Immunostaining identified type II collagen in the extracellular matrix at 2 weeks of culture, and type I collagen and osteocalcin were later synthesized by round cells. von Kossa's reaction showed extensive precipitation of calcification throughout the flocculent materials. Ultrastructural analysis showed that the cells surrounded by calcified matrix strongly resembled osteocytes. CONCLUSIONS: The present study suggested that the Meckel's cartilage chondrocytes can express the osteocyte-like phenotype in vitro during synthesis of bone-type marker proteins such as osteocalcin or type I collagen.

Alkaline Phosphatase↗
PubMed2000

Extracellular matrix of the human aortic media: an ultrastructural histochemical and immunohistochemical study of the adult aortic media.

Aortic distensability is the key to normal aortic function and relates to the lamellar unit in the media. However, the organization of the extracellular matrix components in these lamellar units, which are largely responsible for the distensability, is insufficiently known, especially in the human. We therefore performed a detailed ultrastructural analysis of these components. Thoracic aortas of 56 individuals (age 45-74 years), none of whom suffered from aortic disease, were studied by immunoelectron microscopy of elastin, collagen types I, III, IV, V, and VI, fibronectin, and fibrillin-1, and by ultrastructural histochemistry of proteoglycans, which were further characterized by enzymatic digestion. The elastic lamellae were closely associated with thick collagen fibers containing types I, III, and V collagen. Between these collagen fibers, numerous complex, circumferentially oriented streaks of elastin protruded from the lamellae. In contrast to what is usually reported in the aortas of experimental animals, the smooth muscle cells preferentially adhered to these ill-defined streaks rather than directly to the solid lamellae. Fibrillin-1- and type VI collagen-containing bundles of microfibrils (oxytalan fibers) were also involved in the smooth muscle cell-elastin contact. The smooth muscle cells were invested by basal lamina-like layers connecting them to each other as well as to the oxytalan fibers. Unexpectedly, these layers were abundantly labeled by anti-fibronectin, whereas type IV collagen, a specific basement membrane component, was mainly found in larger, flocculent deposits. The proteoglycans present were collagen-associated dermatan sulfate proteoglycan, cell-associated heparan sulfate proteoglycan, and interstitial chondroitin sulfate proteoglycan. Our observations demonstrate that the extracellular matrix in the human aorta is extremely complex and therefore differs from most descriptions based on experimental animals. They serve as reference for future studies on aortic diseases, such as aneurysmas and dissections.

Aged↗
PubMed1996

Role of immunocytochemistry, electron microscopy, and DNA analysis in fine-needle aspiration biopsy diagnosis of Wilms' tumor.

We reviewed the cytologic features and results of ancillary studies in eight fine-needle aspiration biopsies (FNAB) performed by posterior approach in 8 patients with unresectable Wilms' tumor (WT). Chemotherapy was given following the FNAB diagnosis of WT, which was confirmed subsequently by histologic examination of surgically resected specimens. Indications for FNAB included: unresectable tumor, bilateral disease, initial presentation with metastatic disease, uncertainty regarding tumor site, and documentation of recurrence. Cytologic examination revealed blastemal cells (8/8 aspirates), spindle cells (3/8 aspirates), and epithelial differentiation or tubules (3/8 aspirates). There was no cytologic evidence of anaplasia in any of the cases. Immunocytochemical studies on cell blocks and/or smears showed cytokeratin positivity in 5/8 and vimentin positivity in 5/5 of the aspirates in which these studies were performed. Focal positivity for neuron-specific enolase (NSE) was seen in 3/3 aspirates. Stains for actin and leukocyte-common antigen were negative (0/3 and 0/2 aspirates, respectively). DNA ploidy analysis of the aspiration material by flow cytometry revealed near-diploid populations in three aspirates. Electron microscopic findings helpful for diagnosis included: cell junctions, microvilli, flocculent basement membrane-like material, cilia, autophagolysosomes, and lack of neuroectodermal differentiation. Diagnostic morphologic pitfalls for an incorrect diagnosis of neuroblastoma included nuclear molding (all aspirates), pseudorosette formation (one aspirate), and focal NSE positivity (3/3 aspirates). None of the tumors showed anaplasia on histologic examination. Cytologic recognition of the triphasic cellular components of WT (blastemal cells, spindle cells, and epithelial cells) can be helpful for a correct diagnosis; however, in 5/8 aspirates in this study, only the blastemal component was present. In these cases, immunocytochemical stains and electron microscopy proved useful in arriving at a correct FNAB diagnosis of WT. However, NSE positivity can be a pitfall for a diagnosis of neuroblastoma if the radiologic, clinical, and other cytologic features are not clearly delineated. Presence of cytokeratin and vimentin positivity would be helpful in the diagnosis of WT in such instances.

Biopsy, Needle↗
PubMed2000

Regression of the lateral oviducts during the larval-adult transformation of the reproductive system of Melipona quadrifasciata and Frieseomelitta varia.

Toward the end of the larval phase (prepupa), the reproductive systems of Melipona quadrifasciata and Frieseomelitta varia workers are anatomically similar. Scanning electron microscopy showed that during this developmental phase the right and left ovaries are fused and form a heart-shaped structure located above the midgut. Each ovary is connected to the genital chamber by a long and slender lateral oviduct. During pupal development, the lateral oviducts of workers from both species become extremely reduced due to a drastic process of cell death, as shown by transmission electron microscopy. During the lateral oviduct shortening, their simple columnar epithelial cells show some signs of apoptosis in addition to necrosis. Cell death was characterized by cytoplasmic vesiculation, peculiar accumulation of glycogen, and dilation of cytoplasmic organelles such as mitochondria and rough endoplasmic reticulum. The nuclei, at first irregularly contoured, became swollen, with chromatin flocculation and various areas of condensed chromatin next to the nuclear envelope. At the end of the pupal phase, deep recesses marked the nuclei. At emergence, worker and queen reproductive systems showed marked differences, although reduction in the lateral oviducts was an event occurring in both castes. However, in queens the ovarioles increased in length and the spermatheca was larger than that of workers. At the external anatomical level, the reproductive system of workers and queens could be distinguished in the white- and pink-eyed pupal phase. The metamorphic function of the death of lateral oviduct cells, with consequent oviduct shortening, is discussed in terms of the anatomical reorganization of the reproductive system and of the ventrolateral positioning of adult worker bee ovaries.

Animals↗
PubMed1976

Signet-ring stromal tumor of ovary. Histochemical, light, and electron microscopic study.

A peculiar primary ovarian neoplasm occurring in a 28-year-old woman is presented. The tumor cells showed extensive cytoplasmic vacuolation, resulting in a "signet-ring" appearance similar to what was described in Krukenberg tumors. The tumor was studied histochemically, as well as by light and electron microscopy. The cells appeared to be uniform. A moderately electron-dense flocculent material was present in the cytoplasmic vacuoles. similar material was seen in the intercellular matrix with some fibrillary structures suggesting a protein structure. This, coupled with the lack of any basement membrane material around the tumor cells, indicates a mesenchymal tumor that is probably derived from the multipotent ovarian stromal cell. The features that help to differentiate this tumor from other ovarian tumors with clear or vacuolated cells are discussed. Because of its gross and microscopic appearance, the tumor is expected to behave in a benign fashion.

Adenocarcinoma, Mucinous↗