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PubMed1991

Negative staining and genesis of D-periodicity in native collagen fibrils.

An investigation was carried out on the mechanism which gives rise to the banding exhibited by collagen fibrils after negative staining. The negative staining (phosphotungstic acid) band patterns of native collagen fibrils (type I), isolated from calf reticular dermis, were compared with computer-drawn band patterns. The stimulations were based on the primary structure of bovine type I collagen, the "quarter stagger" molecular packing and different conformations of telopeptides. The results suggest that in negative staining, the stain exclusion effect depends on both spatial factors and water repelling factors being the "bulkiness" (molecular volume/length ratio) as well as the hydrophobicity of the amino acids of alpha 1 (I) and alpha 2 (I) chains directly involved. No final conclusion could be drawn about the contribution of positive staining to negative staining. Improvements in the simulations were achieved when the telopeptides were shaped according to particular conformational models.

Animals↗
PubMed2006

[The clinicopathological endomyocardial biopsy analysis in cardiac transplant recipients due to end-stage heart failure].

OBJECTIVE: Endomyocardial biopsies from 42 (35 males and 7 females, aged 43.3 years) heart transplant recipients due to end-stage heart failure between June 2004 and January 2006 in our institute were obtained for pathological studies. METHODS: Sixteen patients underwent 1 endomyocardial biopsy (right ventricular septum) between 13 days to 5 months, 13 patients underwent second biopsy between 1.5 to 8 months and 10 patients underwent third biopsy between 3 to 8.5 months post transplantation. Specimen were stained by hematoxylin-eosin (HE) and Phosphotungstic Acid Hematoxylin (PTAH) and observed under light microscope and cardiac allograft rejection were evaluated according to the Revision of the 1990 working formulation for the standardization of nomenclature in the diagnosis of heart rejection in 2004. RESULTS: The rejection grades were as follows: Grade 0 R in 31 biopsies; Grade 1 R (mild rejection 1990 grade 1A, 1B and 2.) in 30 biopsies; Grade 2 R (moderate rejection, 1990 grade 3A) in 3 biopsies; Grade 1 R cellular rejection companies with humoral rejection in 1 biopsy. Cellular rejection with Quilty effect was found in 2 biopsies. Ischemic myocardial injury presented in 4 biopsies. Quilty effect was observed in 1 biopsy. Cytomegalovirus or toxoplasmic myocarditis was not observed. CONCLUSIONS: Endomyocardial biopsy (EMB) is a valuable diagnostic procedure for rejection surveillance in heart allograft recipients. The observed low rejection incidence and mild rejection from specimens of our heart recipients were comparable to the results of developed countries.

Adolescent↗
PubMedDate not supplied

[Morphometric studies of biological changes in synapses of the human caudate nucleus].

In the adult the caudate nucleus decreases with increasing age. Light microscopic measurements result in smaller sized neurons and a reduced neuropil in the aged. Comparable to a sintering, nerve cells move nearer, and in consequence, their density increases. The total number of nerve cells, however, does not change remarkably. Using electronmicroscopic methods the aging of synapses was morphometrically examined: Blocks of the caudate nucleus were cut out of formalin-fixed brains from 43 males who had died between the 22nd and 102nd year of age without any neurological symptoms. The blocks were contrasted with EPTA (ethanolic phosphotungstic acid) and embedded in araldite. Though the whole tissue was autolytic, presynaptic and postsynaptic densities were well-preserved and clearly visible. Their numbers and sizes were measured with semiautomatic procedures. The regression analysis shows a significant decrease of the density of synapses with increasing age. The aging of the human caudate nucleus is characterized by a decrease of its volume, by a reduction of the size of neuronal perikarya, and a diminution of the number of synapses per neuron. But the total number of nerve cells remains nearly constant.

Adult↗
PubMed1976

[Ultrastructure of B. pertussis using cryoultramicrotomy].

The authors pointed to a possibility of using the method of cryoultramicrotomy in studying the ultrastructure of Gram negative B. pertussis bacteria under the following conditions: a) fixationwith a 5% glutaraldehyde on cacodylate buffer (pH 7.5) for 30 min; b) replacement with a 30% dimethylsulfoxide in distilled water with a subsequent embedding of the material into tissue-tek; c) freezing in fluid nitrogen for 5 min; d) cutting at a temperature of -- 90% degrees C and at the temperature of glass knife of -- 40 degrees C, the knife angle of alpha = 45 degrees, beta = 6 degrees, and the cutting velocity of 5 mm/sec; e) placing of sections on copper grates covered with a 0.1% moulding membrane; d) contrasting with a 2% phosphotungstic acid queous solution (pH 7.5) for 5 sec and with a 3% uranil acetate on water for 5 min. Use of the mentioned method pemitted to detect structures localized in B. pertussis cytoplasm and also to trace the dynamics of their formation.

Bordetella pertussis↗
PubMed1990

[Characteristics of synaptic structures of human brain in epilepsy and epileptic syndrome ].

The synaptoarchitectonics of different structural formations (cortex, hippocampus, amygdaloid complex) were assayed in 3 patients with epilepsia and 2 patients with associated temporal lobe glioma and epileptic syndrome using a selective technique of staining synapses with phosphotungstic acid and their morphometric study. It has been established that in the mechanism of brain epileptization, of paramount importance is the formation of new immature contacts, hypertrophy of functionally active synapses followed by their splitting and complication of the synaptic arrangement by the convergent and divergent type in the presence of derangement and death of a part of synapses. This is characteristic to a greater measure of the cortex from the area marked by regular epileptic activity and to a less measure of the hippocampus and amygdaloid complex.

Adult↗
PubMed1990

Ultrastructural in vitro characterization of a porous hydroxyapatite/bone cell interface.

In order for the hydroxyapatite implant material interface to new bone to be characterized, osteogenic mouse calvarial mesenchymal cells were grown in vitro in contact with a porous hydroxyapatite (PHA). After the mesenchymal cell culture was incubated for 12 to 13 days, the resulting tissue-containing bone colonies were fixed, embedded, sectioned, and stained for microscopic evaluation. Light and transmission electron microscopy (with conventional staining) and phosphotungstic acid cytochemistry were used to explore and record the optical microscopic and ultrastructural interfaces at the hydroxyapatite surface. Osteoblasts, fibroblasts, bone, and cartilage were observed and photographed at the implant surface. Osteoblasts found in conjunction with well-developed collagen, matrix vesicles in the extracellular matrix, and newly formed hydroxyapatite crystals on the PHA surface confirmed the beginning of woven bone formation. Collagen fibers were observed directly in contact with the PHA when osteoblasts were present. Polysaccharides were localized among the collagen fibers in the implant-cell extracellular space, indicating a rich complex carbohydrate layer in relation to the collagen of immature bone. Fibroblasts and chondroblasts at the implant surface secreted no collagen, but an amorphous layer was visible between the fibroblasts and the implant surface. When polysaccharides were stained, an electron-dense film appeared where the amorphous layer came into contact with the implant material. Collagen was secreted from the cell surface furthest from the implant. Osteoblasts and fibroblasts/chondroblasts, when surrounding PHA, seem to take on two different interfacial functions: Osteoblasts secrete collagen in a bone-initiating extracellular matrix with carbohydrates at the implant surface, whereas fibroblasts/chondroblasts appear to attach to the implant with a carbohydrate-rich attachment substance, but with no collagen at the interface. This study confirms in vivo data that PHA is a viable implant material because it is biocompatible and, unlike several other materials, appears to stimulate, or at least to permit, osteogenesis.

Animals↗
PubMed1991

Defects in diagnostic kits for determination of urate in serum.

Certain diagnostic kits that measure serum urate by the Barham and Trinder principle of enzymic liberation of oxygen and its combination with chromogens can give results for urate in fresh serum that are approximately 20% lower than results from serum stored at ambient temperature for 72 h. In fresh serum, antioxidants compete with chromogen for liberated peroxyl-oxygen. We postulate that during storage the interfering antioxidant substances are destroyed. In some diagnostic kits, L-ascorbate oxidase is added to the reaction, eliminating some but not all of this effect. We discuss defects of several commercially available kits for determination of serum urate and recommend comparing results of these kits with results from the phosphotungstic acid method as a precaution against falsely low results.

Blood Preservation↗
PubMed1990

[Cystinuria: description of a simple method of determination and our 5-year clinical experience].

Ion exchange chromatography is the best method for the determination of cysteine in urine, but it requires an expensive apparatus, specialized technicians and a long time. The major colorimetric procedure is the nitroprusside color reaction first described by Brand, but it involves the reaction with toxic cyanide reagent. Moreover commercial stick are not available. We have experienced a colorimetric procedure in which the sulfhydryl group of cystine reduces phosphotungstic acid to tungstic blue, which is determined photometrically. This procedure avoids the use of cyanide. We used this screening test during 5 years of ambulatory evaluation of nephrolithiasis and we found these results: urine cystine 191 controls: 87 +/- 57 mg/day, 870 stone oxalate and uric acid patients: 99 +/- 57 mg/day, 11 stone cystine patients: 479 +/- 379 mg/day (p 0.001). A close correlation was found in stone cystine patients between our data obtained in the same sample with ion exchange chromatography. We conclude that this inexpensive and simple method can be recommended as a screening test for cystinuria.

Adolescent↗
PubMed1986

[Electron microscopic cytochemical and morphometric study of the cerebral cortex synapses in postmortem autolysis].

Brain tissue staining with phosphotungstic acid was performed to assay neurofilament accumulations in synapses in the molecular layer of the rat cerebral cortex at different intervals after the animals' death. It was found that autolysis began in the dense projections of presynaptic grid. Within 30 min autolysis developed in mature and very young (immature) synapses. By the 90th min autolysis in asymmetric synapses was considerably enhanced. 6 hours later autolysis involved mature and indefinite synapses.

Animals↗
PubMed1987

Disseminated intravascular coagulation (DIC). Immunohistochemical study of fibrin-related materials (FRMs) in renal tissues.

Renal tissues of 208 autopsied cases were examined. Malignant neoplasm with hematological malignancies often accompanied DIC. Tissue sections were stained with hematoxylin and eosin and Mallory's phosphotungstic acid hematoxylin (PTAH), and were applied for immunoperoxidase method (IP), using antisera against human fibrinogen, FDP-D and FDP-E. Histologically in 80 cases (38%) fibrin or fibrinogen related materials (FRMs) were observed in the glomerular capillary or the intratubular area or in both. FRMs were PTAH or IP positive or both in 23 of the 26 cases (88%) clinically diagnosed as DIC. In the remaining three cases anticoagulants probably interfered with FRMs observation. This study showed the PTAH stain was nonspecific and insensitive to FRMs, and that IP was necessary for a pathological diagnosis of DIC. The presence of FRMs in the renal tubuli is an important finding in confirming DIC. DIC may be present histologically in the absence of clinical DIC symptoms.

Disseminated Intravascular Coagulation↗
PubMed1989

[The effect of freezing-thawing of human blood serum on the results of the determination of high density lipoprotein cholesterol].

The effect of repeated freezing-defreezing of the serum on the values of high density lipoprotein cholesterol measured by Abel's method was studied. Mixtures for the precipitation of lipoproteins were as follows: heparin + Mn2+, dextran sulfate + Mg2+, phosphotungstic acid + Mg2+, and polyethylene glycol. Variations in the measured cholesterol values were insignificant. Statistically reliable results (p less than 0.05) were obtained only with polyethylene glycol, with the variations not surpassing 3%.

Blood↗
PubMed1989

Oxyphilic granular cell adenoma (oncocytoma)--a histochemical and ultrastructural study.

Oxyphilic granular cell adenoma (oncocytoma) is extremely rare usually benign neoplasm. Specimens from four oncocytomas of the parotid gland were studied by light microscopy using different histochemical stains, and by electron microscopy. The haematoxylin and eosin stained sections revealed large cells with eosinophilic granular cytoplasm. These granules appear blue with phosphotungstic acid haematoxylin stain, purplish blue with mallory aniline blue stain and are moderately reactive to alcian blue and PAS. No elastic fibers could be seen in the intercellular substance using Verhoeff's stain. At the ultrastructural level, the tumour cells were characterized by great numbers of mitochondria. Many of the mitochondria contained glycogen granules. Dividing mitochondria were also observed.

Adenoma↗
PubMedDate not supplied

[Hypoalphalipoproteinemia and atherosclerosis. Genetic and biochemical profile of 10 families].

The results of lipoprotein studies performed in 67 members of 10 kindreds with familial hypoalphalipoproteinemia are presented. Probands were ten patients referred to the Lipid Clinic of the National Institute of Cardiology for evaluation of their lipid profile, all of whom had history of a definite myocardial infarction occurring before they had reached age 60. Their only plasma lipid abnormality was a reduction of the cholesterol fraction associated with high-density lipoproteins (C-HDL) below the corresponding age-sex specific fifth percentile. We studied 57 other individuals including probands spouses and available first-degree relatives. All participants were clinically examined and their complete coronary risk factor profile was assessed. After a 12 hour fast, plasma samples were obtained for lipid analysis, total cholesterol and trïglycerides were measured by enzymatic methods, C-HDL was determined in the supernatant after plasma precipitation with magnesium chloride: phosphotungstic acid. Low-density lipoprotein cholesterol (C-LDL) was estimated with the formula proposed by DeLong. For every family a pedigree was constructed and statistically analyzed to assess the within-family clustering of low C-HDL levels and the pattern of transmission of the abnormal phenotypes. Mean C-HDL level for propositii was 24.3 mg/dl, the corresponding value for the C-LDL/C-HDL ratio (atherogenic index) was 4.9 and it was elevated above 3.5 (average coronary risk) in 7/10 (70%) of these patients. Obesity, defined by a Quetelet index above 28 in men and 26 in women was present in 4/10 (40%) of the probands, 3/10 (30%) had stable non insulin-dependent diabetes mellitus, prevalence figures for the other coronary risk factors was very low. In addition to probands, the hypoalphalipoproteinemic phenotype was found in 30/57 (52.6%) subjects including spouses (two cases) and first-degree relatives. For these 30 cases the mean C-HDL value was 32 mg/dl. In all ten reported kindred, we clearly observed either horizontal, vertical or both types of within-family transmission of the aberrant phenotype. This finding was considered to be most compatible with the presence of a primary genetic abnormality affecting C-HDL metabolism in all these kindreds in spite of the fact that some of the probands had some conditions like diabetes or obesity that are sometimes associated with secondary reductions of C-HDL. Due to the lack of a reliable biochemical marker, the distinction between primary and secondary hypoalphalipoproteinemia in individual cases is frequently impossible, for this reason the diagnostic assessment depends on family studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

[Methodologic studies of the isolation of VLDL using the lipoprotein precipitation reaction in the preparation of apolipoprotein E (Apo E)].

Several lipoprotein precipitation reactions were examined in the isolation of VLDL for apo E phenotyping in comparison to ultracentrifugation. MgCl2-Heparin- and phosphotungstic acid precipitation revealed the best results, although an apo E phenotyping was possible in only 40% of the samples. Ultracentrifugation was unequivocally superior to lipoprotein precipitation reactions.

Apolipoproteins E↗
PubMed1989

[Paramembraneous microfilamentous structures of the synapses of rat cerebral cortex during sensitization by brain antigens].

On the material contrasted by phosphotungstic acid the state of paramembranes microfilament structures of interneuronal contacts of molecular layer of sensomotor field cortex of rat brain of Krushynsky-Molodkina line during sensitization by homologous brain antigens was studied. Sharp reduction of general density of synapses and symmetric contacts because of damaging of paramembranes microfilament structures of cerebral cortex synapses and reduction of new contacts was proved that plays an essential role in changing of brain integrating activity during different pathological processes connected with autoimmune mechanism of neuronal tissue damaging.

Actin Cytoskeleton↗
PubMed1978

[Glycoproteins and proteoglycans in the predentin and dentin matrix in the rat: an ultrastructural study].

The ultrastructural distribution of the protein-polysaccharides was studied in the predentinal and dentinal matrices of the rat. Used for the indentification of the glycoproteins, the chromic-phosphotungstic acid mixture (Rambourt, 1967) weakly contrasted the predentine, underlined the mineralization front and impregnated the dentinal matrix. Alcian blue (Goldberg et al., 1977) as well as bismuth nitrate (Serafini-Fracassini and Smith, 1966), cationic stains for the proteoglycans, produced a strong contrast in the predentine, whereas in the dentine, which appeared clear, only 100 to 150 A granules associated with the periodic collagen striations were stained. This inverse variation between non collagenous proteoglycans and glycoproteins is discussed in relation to the mineralization process.

Animals↗
PubMed1988

Fine structure of neuronal spherical arginine-rich bodies of substantia nigra and locus coeruleus in the human brain.

Neuronal spherical bodies, rich in arginine, of catecholamine neurons in man display staining reactions of mitotic chromosomes and myelin basic protein. They show a unique fine structure and density in the EM after phosphotungstic acid hematoxylin block-staining. With an electron-lucent core, a dense rim and a limiting double membrane they stand out and are differentiated from all other neuronal inclusions, especially melanin. Protein bodies were found inside mitochondria, where they apparently originate as small globules in the matrix. They later enlarge into spheres by obliterating the cristae, but retaining the outer membranes of the parent mitochondrion. The arginine-rich basic protein of the spherical bodies, it is argued, may be involved in the modulation of excitability of the catecholamine neurons in man.

Adult↗