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PubMed1999

Reference standardization and analytical performance of a liquid homogeneous high-density lipoprotein cholesterol method compared with chemical precipitation method.

BACKGROUND: The use of high-density lipoprotein cholesterol (HDL-C) levels as a risk factor for coronary heart disease necessitates an accurate and precise method for measuring HDL-C. The Centers for Disease Control and Prevention HDL-C reference method (RM) and designated comparison method (DCM) are time-consuming, expensive, and impractical for routine clinical use. We evaluated the Liquid N-geneous (LN-gen) HDL-C assay (Genzyme Diagnostics, Cambridge, Mass) to determine if this homogeneous reagent meets the National Cholesterol Education Program requirements for HDL-C evaluation. DESIGN: Accuracy of the LN-gen HDL-C assay was compared in combination with phosphotungstic acid (PTA) precipitation with DCM HDL-C for normotriglyceridemic serum specimens (triglycerides < 2.0 g/L) and with RM HDL-C for specimens with triglycerides levels > or = 2.0 g/L. SETTING: Genzyme Diagnostics (with RM and DCM assayed by Pacific BioMetrics Inc, Seattle, Wash) and the Lipid Reference Laboratory of the University Hospital Rotterdam, The Netherlands. RESULTS: Linear regression to DCM (n = 90) was (LN-gen = 1.015 DCM + 0.01 g/L, r = 0.993, SE = 0.015 g/L) and (PTA = 1.004 DCM - 0.017 g/L, r = 0.980, SE = 0.025 g/L), with a mean percent bias to DCM of 3.3% and -2.8% for LN-gen and PTA, respectively. The comparison with RM (n = 69) showed an increased mean bias for PTA (-5.8%) as compared with LN-gen (1.5%). The correlation and regression equations were (LN-gen = 1.020 RM - 0.002 g/L, r = 0.985, SE = 0.017 g/L) and (PTA = 1.042 RM - 0.032 g/L, r = 0.984, SE = 0.018 g/L). The precision of LN-gen was confirmed at < 2.1% coefficient of variation, and the total error was calculated to be < or = 7.7% for both normotriglyceride and elevated triglyceride specimens at HDL-C decision points of 0.35 g/L and 0.60 g/L. CONCLUSIONS: The LN-gen HDL-C assay offers a cost-effective convenient method for meeting the 1998 precision, bias, and total error recommendations of the National Cholesterol Education Program.

Blood Specimen Collection↗

PubMed2004

Oncocytic biliary cystadenocarcinoma: a case report and review of the literature.

We report an unusual case of biliary cystadenocarcinoma with oncocytic differentiation. The patient was a 43-year-old woman who presented with right upper quadrant pain. Imaging revealed a 16 x 10 x 10-cm, heterogenous, right hepatic mass with extension into the right atrium. Surgical resection revealed a papillary neoplasm of malignant cells with atypical hyperchromatic nuclei and prominent nucleoli lining fibrovascular cores. Mesenchymal stroma was not present. The majority of the epithelial cells had abundant eosinophilic granular cytoplasm, consistent with oncocytic differentiation. There was extensive stromal and hepatic parenchymal invasion. Immunohistochemical staining revealed a "biliary pattern" of cytokeratin subset immunoreactivity, with positivity for cytokeratin 7 and an absence of staining with cytokeratin 20. The tumor was negative for mucin, carcinoembryonic antigen, alpha-fetoprotein, calretinin, CD31, and chromogranin. There was granular cytoplasmic staining with phosphotungstic acid hematoxylin, consistent with the presence of abundant mitochondria. Electron microscopy revealed abundant mitochondria within the neoplastic cells. This case is quite unusual because female patients only rarely lack the characteristic ovarian-like mesenchymal stroma of biliary cystadenomas/cystadenocarcinomas. Furthermore, to our knowledge, oncocytic differentiation in this neoplasm has been reported previously on only 2 occasions. The biologic behavior and prognostic significance, if any, of the lack of mesenchymal stroma in female patients or the presence of oncocytic differentiation remains to be further elucidated as more of these cases are described.

Adult↗

PubMedDate not supplied

Familial dilated cardiomyopathy of young Portuguese water dogs.

A novel dilated cardiomyopathy (DCM) in 12 related Portuguese Water Dogs was identified by retrospective analysis of postmortem and biopsy case records. Male and female puppies born to clinically healthy parents typically died at 13 (+/- 7.3) weeks of age (range, 2-32 weeks) because of congestive heart failure. Puppies died suddenly without previous signs or with mild depression followed by clinical signs of congestive heart failure 1-5 days before death. There was no sex predilection. The hearts were enlarged and rounded, with marked left ventricular and atrial dilation. No other significant structural cardiac defects were noted. The histologic changes in the myocardium were diffuse and characterized by myofibers of irregular sizes separated by an edematous interstitium. The myofibers had multifocal swollen, cleared segments often involving perinuclear areas that contained granular, phosphotungstic-acid-hematoxylin-positive material consistent with mitochondria. There was loss of the cross-striation pattern, and intercalated discs were difficult to identify. There was no evidence of concurrent myocardial fibrosis; rare chronic inflammatory infiltrates were noted in one dog. Noncardiac skeletal muscles were not affected. The underlying cause is unknown. From the pedigree analysis, an autosomal recessive pattern of inheritance is suspected. Based on the histologic findings, this DCM is most likely due to an underlying molecular (biochemical or structural) defect. The early onset and rapid progression of the disease makes this a clinically distinctive form of canine DCM.

Animals↗

PubMed1999

Modification of postsynaptic densities after transient cerebral ischemia: a quantitative and three-dimensional ultrastructural study.

Abnormal synaptic transmission has been hypothesized to be a cause of neuronal death resulting from transient ischemia, although the mechanisms are not fully understood. Here, we present evidence that synapses are markedly modified in the hippocampus after transient cerebral ischemia. Using both conventional and high-voltage electron microscopy, we performed two- and three-dimensional analyses of synapses selectively stained with ethanolic phosphotungstic acid in the hippocampus of rats subjected to 15 min of ischemia followed by various periods of reperfusion. Postsynaptic densities (PSDs) from both area CA1 and the dentate gyrus were thicker and fluffier in postischemic hippocampus than in controls. Three-dimensional reconstructions of selectively stained PSDs created using electron tomography indicated that postsynaptic densities became more irregular and loosely configured in postischemic brains compared with those in controls. A quantitative study based on thin sections of the time course of PSD modification indicated that the increase in thickness was both greater and more long-lived in area CA1 than in dentate gyrus. Whereas the magnitude of morphological change in dentate gyrus peaked at 4 hr of reperfusion (140% of control values) and declined thereafter, changes in area CA1 persisted and increased at 24 hr of reperfusion (191% of control values). We hypothesize that the degenerative ultrastructural alteration of PSDs may produce a toxic signal such as a greater calcium influx, which is integrated from the thousands of excitatory synapses onto dendrites, and is propagated to the neuronal somata where it causes or contributes to neuronal damage during the postischemic phase.

Animals↗

PubMed1976

[Method of ultrastructural analysis with the aid of measuring television complex].

The area of the section of presynaptic dense projections of the active zone of axondendritic synapses of the rat's cortex was measured using a television complex. Tissue specimens were contrasted with phosphotungstic acid. Morphometry was carried out in the regime of error correction in measurement, the errors arising in scanning process of image. The area of the section of mitochondria, lysosome, nucleoli, channels and tanks of the endoplasmic reticulum may be measured by the method suggested. Quantitative data, obtained by the morphometry of the synapse ultrastructure, may serve a basis for understanding the mechanism by which synapses are involved in information processes of the central nervous system.

Animals↗

PubMedDate not supplied

[Double modification of cytidine residues in DNA].

The reaction of O-beta-diethylaminoethylhydroxylamine (O-beta-HA) with cytidine was studied and its mechanism was shown to be analogous to that of the reaction of hydroxylamine of O-methylhydroxylamine with cytidine. In experiments involving reaction of denatured DNA with O-beta-HA., Sephadex G-15 columns were used for the quantitative separation of normal and modified nucleosides after enzymatic hydrolysis of modified DNA by exonuclease A5 followed by alkaline phosphatase treatment. DNA cytidine residues of free cytidine with O-beta-HA. Modified cytidines can form complex with phosphotungstic acid (PTA). It was shown that one mole of PTA was bound per one mole of modified cytidine either in DNA or in free state. Electron microscopic examination of denatured DNA molecules modified by O-beta-HA and reacted with PTA revealed linear arrays of electron-scattering spots which presumably correspond to PTA molecules complexed with modified cytidine in DNA chains.

Alkaline Phosphatase↗

PubMed2000

Protein aggregation after transient cerebral ischemia.

Protein aggregates containing ubiquitinated proteins are commonly present in neurodegenerative disorders and have been considered to cause neuronal degeneration. Here, we report that transient cerebral ischemia caused severe protein aggregation in hippocampal CA1 neurons. By using ethanolic phosphotungstic acid electron microscopy (EM) and ubiquitin immunogold EM, we found that protein aggregates were accumulated in CA1 neurons destined to die 72 hr after 15 min of cerebral ischemia. Protein aggregates appeared as clumps of electron-dense materials that stained heavily for ubiquitin and were associated with various intracellular membranous structures. The protein aggregates appeared at 4 hr and progressively accumulated at 24 and 48 hr of reperfusion in CA1 dying neurons. However, they were rarely observed in dentate gyrus neurons that were resistant to ischemia. At 4 hr of reperfusion, protein aggregates were mainly associated with intracellular vesicles in the soma and dendrites, and the nuclear membrane. By 24 hr of reperfusion, the aggregates were also associated with mitochondria, the Golgi apparatus, and the dendritic plasmalemma. High-resolution confocal microscopy further demonstrated that protein aggregates containing ubiquitin were persistently and progressively accumulated in all CA1 dying neurons but not in neuronal populations that survive in this model. We conclude that proteins are severely aggregated in hippocampal neurons vulnerable to transient brain ischemia. We hypothesize that the accumulation of protein aggregates cause ischemic neuronal death.

Animals↗

PubMed2000

Intracranial neoplasms in Ibadan, Nigeria.

OBJECTIVE: To determine the pattern of histopathological variants of intracranial neoplasms, relative distribution of the variants in the age groups and also to determine the gender differences that exist in these tumours. DESIGN: Case control study. SETTING: Department of Pathology, University College Hospital, Ibadan, Nigeria. PATIENTS: Two hundred and ten histologically confirmed cases of intracranial neoplasms seen during eleven-year period (1980 to 1990) were analysed. INTERVENTIONS: Slides of tumours stained with haematoxylin and eosin, reticulin and phosphotungstic acid haematoxylin. RESULTS: Two hundred and ten intracronial neoplasms comprising 172 primary and 48 secondary neoplasms were seen. One hundred and thirty five neoplasms occurred in adults and 75 in children. There was no gender difference, the ratio being 1:1. Gliomas accounted for the largest group of tumours followed by metastases to the brain. Of the gliomas, astrocytoma was the commonest. Craniopharyngiomas were found to be common in children. Germ cell tumours were found to be uncommon. CONCLUSION: Gliomas are the commonest group of intracranial neoplasms in both adults and children. This is followed by metastatic tumours. Tumours of the sella turcica are predominantly found in children. Involvement of the brain in disseminated Burkitt's lymphomas is predominantly found in Africans as the Burkitt's tumour is uncommon in non Africans.

Adolescent↗

PubMed1975

Improved biuret procedure for routine determination of urinary total proteins in clinical proteinuria.

This communication describes and evaluates an improved routine methodology for quantitating clinical proteinuria. Based on investigations of Piscator and of Savory et al., a modified Tsuchiya's reagent (ethanolic HCI-phosphotungstic acid) is used to precipitate proteins at 56 degrees C, followed by biuret spectrophotometry at 540 nm. The accuracy of the proposed procedure was assessed by comparisons with results obtained by using an ultrafiltration membrane that retains solutes with an average molecular weight in excess of 10 000 for separating of urinary proteins before they are measured with the biuret reaction. Precision of the method (coefficient of variation) is typically 2-3%.

Evaluation Studies as Topic↗

PubMed1975

[Ontogeny of special endoplasmic reticulum complexes in neurons of the lateral geniculate body in rats].

1. The ultrastructure of special membranous convolutions (MC) of the endoplasmic reticulum (complex convolutions, KARLSSON 1966), was studied in neurons of the lateral geniculate body in postnatal and adult rats. 2. The MC situated in the perikaryon are often attached to the nuclear membrane. Their average diameter is about 2 mum. Some MC of elongated form are extended over 6 mum. 3. Smaller MC of similar structure occur within basal dendrites, mainly in the environment of large axo-dendritic desmosomoid junctions. 4. The MC consist of smooth double membranes in a laminar or irregular arrangement, and are in connexion with the rough endoplasmic reticulum. 5. After incubation with ethanolic phosphotungstic acid the intermembranous material of the MC is stained in the same high intensity as this is the case with synaptic junctions. 6. The MC are developed by the rough endoplasmic reticulum during the 5 th and 6 th postnatal weeks. 7. The ultrastructure of the MC of both, normal and dark raised rats shows no significant differences.

Age Factors↗

PubMed2001

[Establishment and implication of an assay for high density lipoprotein phospholipids in human serum].

OBJECTIVE: To develop an assay for high density lipoprotein phospholipids in human serum based on ascorbutate reduction method. METHODS: HDLs were separated from apolipoprotein B-containing lipoproteins by precipitation of phosphotungstic acid and magnesium chloride. Phospholipids of HDL were extracted by ethanol/ether, and dried. After the dried phospholipids were digested by sulphuric acid and perchloric acid, the color was developed by adding ammonium molybdate in ascorbutate. The levels of high density lipoprotein phospholipids (HDL-PL) were measured by spectrophotometry at 700 nm. RESULTS: The coefficients of variation (CV) were 3.6% and 3.7% within two batches of assays. Recovery of isolated HDL-PL added to serum ranged from 98% to 107%, averagely 103%. The established assay for human serum HDL-PL was used to measure the serum levels of 30 hypercholesterolemic subjects, 30 hypertriglyceridemic subjects, 30 combined hyperlipidemic subjects, and 30 normolipidemic subjects. The hypertriglyceridemic subjects had lower HDL-PL level than normolipidemic subjects and hypercholesterolemic subjects (The P values are 0.005 and 0.007 respectively). CONCLUSION: A simple and specific method for assay of HDL-phos-pholipids in human serum has been developed. The above data collected by the use of this method demonstrate the closer relationship between human HDL-PL metabolism and triglyceride metabolism, suggesting that lower HDL-PL level might serve as an index in the assay for type IV hyperlipidemia.

Humans↗

PubMed1975

Elementary particles in isolated rat liver and spleen nuclear membranes.

Elementary spherical particles similar to those described in the mitochondria are found in isolated rat liver and spleen nuclear membranes. The particles are characterized by electron microscopy of sections and preparations negatively stained with phosphotungstic acid or with the ATPase histochemical reaction product. The particles exhibit adenosine triphosphatase activity and have a mushroom-like shape with a sphere about 85-90 angstrom in diameter attached to inner face of the inner nuclear membrane by a stalk about 50 angstrom in length and 35 angstrom in diameter. It is supposed that these particles, just as analogous particles localized at the inner mitochondrial membrane, are involved in the coupling of oxidation and phosphorylation in the nuclear envelope.

Adenosine Triphosphatases↗

PubMed1991

Induced adenocarcinoma of the ascending colon on LE and Wistar/Shhi rats and virus like particles in the serum of colon cancer carrying WF rats.

Intraperitoneal injection of the serum of colon cancer carrying WF rats induced, within two months, colon carcinomas in the ascending colon of LE and Wistar/Shi rats when they were given it during their suckling. We had also induced colon carcinomas in the ascending colon of ACI rats by the same methods. Therefore, it is supported that this serum derived from colon cancer carrying WF rats must have some transmissible agent in itself. In addition, we ultracentrifuged the serum of cancer carrying WF rats and we found, in the sediment, numerous round or oval virus like corpuscles by electron microscopy studies. Negatively stained corpuscles by phosphotungstic acid staining clearly revealed fine spike appearance on their surface. We believe that these virus like corpuscles are the etiological agent for the transmissible colon carcinoma of WF rat strain.

Adenocarcinoma↗

PubMed1964

POWASSAN VIRUS: MORPHOLOGY AND CYTOPATHOLOGY.

Powassan virus, a North American tickborne group B arbovirus, multiplied after simultaneous inoculation into bottles or tubes of virus and trypsinized suspension of continuous-line cultures of rhesus monkey kidney cells, strain LLC-MK2. Cytopathic effects comprising cell rounding and cytoplasmic vacuolation were first observed five days after inoculation. Mixture of Powassan antiserum with virus before inoculation into tissue cultures inhibited the appearance of cytopathic effects. Hemagglutinins for rooster erythrocytes, optimally at pH 6.4 and 22 degrees C., first appeared in tissue culture supernatant fluids four days after inoculation.Electron microscopic observation of thin sections of infected tissue culture cells showed virus particles 360-380 A.U. along outer cell membranes and edges of cytoplasmic vacuoles. In phosphotungstic acid negatively stained preparations, intact virus particles, 400-450 A.U. total diameter, were observed inside infected cells. In particles in which the peripheral layer became discontinuous, geometrically arranged subunits compatible with cubic symmetry were observed.

Animals↗

PubMed1992

A multicenter evaluation of lipid profiling with a compact analyzer (Miles Clinistat).

We evaluated the Clinistat Analyzer (Miles Inc., Diagnostics Division, Elkhart, IN) for measuring cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol at three medical centers. The system, based on multilayer film technology, uses precalibrated, dry film reagent disks. Ten microliters of serum is applied to the dry film reagent disk in the test procedure. For HDL-cholesterol measurement, serum is pretreated by precipitation with phosphotungstic acid and magnesium chloride. Total precision (CVs) of each of the three assays was less than or equal to 5%. The assay ranges were linear and satisfactory for clinical use. Patients' results compared well with established methods. No significant interferences were found with hemolysis, icterus, and lipemia.

Chemistry, Clinical↗

PubMed2005

[The expression of porcine circovirus type 2 ORF2 gene in insect cells and its character].

To produce the recombinant baculovirus transfer plasmid pFast-ORF2, the ORF2 gene of Porcine Circovirus type 2 (PCV2) was subcloned into baculovirus transfer vector (pFastBac(TM1) ) using Bac-to-Bac baculovirus expression system. E. coli DH10Bac (Gibco BRL) containing baculovirus shutter vector (bacmid) and helper vector was transformed with recombinant plasmid pFast-ORF2. Within E. coli DH10Bac, the ORF2 gene was transposed into the bacmid. The colonies of E. coli containing recombinant bacmid (Bac. ORF2) were collected by blue/white selection. The Bac. ORF2 was transfected into sf9 cells to yield AcNPV carrying the PCV2 ORF2 gene, referred to as Ac. ORF2. Expression of the ORF2 gene of PCV2 was confirmed by indirect immunofluorescent assay (IIFA), SDS-PAGE and Western-blotting. The expressed ORF2 gene product had a molecular mass of 28kD and could be recognized by the positive serum of PCV2. The results indicated the ORF2 gene was properly expressed in sf9 cell. It was noteworthy that many self-assembled virus-like particles (VLPs) were found in purified and phosphotungstic acid (PTA) stained PCV2 ORF2 protein by electron microscope. The particles were of similar morphology to the PCV2 virion and some self-assembled virus-like particles had darkly stained centers that made them appear to be empty capsids. Both PCV2 particles and self-assembled particles were approximately 17 nm in diameter.

Animals↗

PubMed1990

Chemically induced mammary gland adenomyoepitheliomas and myoepithelial carcinomas of mice. Immunohistochemical and ultrastructural features.

Myoepithelial cell tumors of the mammary gland have been observed in several mammalian species and are composed of a single cell type (myoepithelium) or, more often, present as a biphasic process including neoplastic ductal epithelial cells. In dogs, these are common tumors, but in humans they are rare neoplasms of the breast, and little is yet known of their pathogenesis, particularly with respect to myoepithelial origin. The present report describes bicellular mammary gland tumors arising from the duct epithelium that were induced in (C57BL/6NCr X DBA/2NCr)F1 (B6D2F1) mice by four weekly oral applications of 1 mg 7,12-dimethylbenz[a]anthracene (DMBA) starting at 8 weeks of age. Mammary tumors developed 7 to 8 months later in 14 of 57 mice, and most showed great morphologic resemblance to human adenomyoepitheliomas and myoepithelial carcinomas. Ultrastructurally, the induced tumors were composed of cuboidal epithelium with a microvillous border originating from the lining duct epithelium and plump oval or highly elongated cells that were identified as myoepithelial in origin. These spindle cells contained abundant microfilaments in parallel orientation, some with focal densities and intermediate filaments that frequently formed loose bundles or compact tonofibrils. The myoepithelial cells possessed well-developed desmosomes and plasma membrane caveolae and were regularly bordered by single or reduplicated basement membranes. By immunohistochemistry, strong immunoreactivity was observed for actin in the myoepithelial tumor component only, whereas cytokeratin was variably present in both duct epithelium and myoepithelium. Neoplastic myoepithelial cells stained purple with phosphotungstic acid hematoxylin (PTAH) and brilliant red with Masson's trichrome. It is suggested that DMBA-induced mouse mammary gland adenomyoepitheliomas and myoepithelial carcinomas may serve as very useful animal models to study myoepithelial tumorigenesis.

9,10-Dimethyl-1,2-benzanthracene↗

PubMedDate not supplied

Stability-indicating methods for the determination of disopyramide phosphate.

Four methods were developed for the determination of intact disopyramide phosphate in the presence of its degradation product. In the first and second methods, third-derivative spectrophotometry and first derivative of the ratio spectra were used. For the third-derivative spectrophotometric method, the peak amplitude was measured at 272 nm, while for the derivative ratio spectrophotometric method, disopyramide phosphate was determined by measuring the peak amplitude at 248 and 273 nm. Both methods were used for the determination of disopyramide phosphate in the concentration range 12.5-87.5 microg/mL, with corresponding mean recovery 100.8 +/- 0.7% for the first method and 99.9 +/- 0.7% and 99.6 +/- 0.7% for the second method at 248 and 273 nm, respectively. In the third method, an ion selective electrode (ISE) was fabricated using phosphotungstic acid as an anionic exchanger, PVC as the polymer matrix, and dibutylsebacate as a plasticizer. The ISE was used for the determination of disopyramide phosphate in pure powder form in the concentration range 10(-2)-10(-5) M. The slope was found to be 58.5 (mV/decade), and the average recovery was 99.9 +/- 1.6%. The fourth method depended on the quantitative densitometric determination of the drug in concentration range of 0.25-2.5 microg/spot using silica gel 60 F245 plates and ethyl acetate-chloroform-ammonium hydroxide (85 + 10 + 5, v/v/v) as the mobile phase, with corresponding mean accuracy of 100.3 +/- 1.1%. The 4 proposed methods were found to be specific for disopyramide phosphate in presence of up to 80% of its degradation product for the spectrophotometric methods, 90% of its degradation for the densitometric method, and 40% for the ISE method. The 4 proposed procedures were successfully applied for the determination of disopyramide phosphate in Norpace capsules. Statistical comparison between the results obtained by these methods and the official method of the drug was done, and no significant differences were found.

Anti-Arrhythmia Agents↗