Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “quantitative analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
PubMed1989

A quantitative analysis of chain-schedule performance.

Six pigeons were trained with a chain variable-interval variable-interval schedule on the left key and with reinforcers available on the right key on a single variable-interval schedule arranged concurrently with both links of the chain. All three schedules were separately and systematically varied over a wide range of mean intervals. During these manipulations, the obtained reinforcer rates on constant arranged schedules also frequently changed systematically. Increasing reinforcer rates in Link 2 of the chain increased response rates in both links and decreased response rates in the variable-interval schedule concurrently available with Link 2. Increasing Link-1 reinforcer rates increased Link-1 response rates and decreased Link-2 response rates. Increasing reinforcer rates on the right-key schedule decreased response rates in Link 1 of the chain but did not affect the rate in Link 2. The results extend and amplify previous analyses of chain-schedule performance and help define the effects that a quantitative model must describe. However, the complexity of the results, and the fact that constant arranged reinforcer schedules did not necessarily lead to constant obtained reinforcer rates, precluded a quantitative analysis.

Journal Article↗
PubMed2005

Evolving concepts in the quantitative analysis of the determinants of the plasma water sodium concentration and the pathophysiology and treatment of the dysnatremias.

The physiologic and clinical implications of the empirical formula originally discovered by Edelman et al [J Clin Invest 37:1236-1256, 1958] relating the plasma water sodium concentration ([Na(+)](pw)) to the total exchangeable sodium (Na(e)), total exchangeable potassium (K(e)), and total body water (TBW) have recently been elucidated. It is quite remarkable that the full significance of the Edelman equation discovered almost 50 years ago had remained unrecognized by clinicians and physiologists until recently. Although Edelman and colleagues had shown that the [Na(+)](pw) is proportional to the magnitude of (Na(e)+ K(e))/TBW, the linear equation relating [Na(+)](pw) to (Na(e)+ K(e))/TBW had a slope greater than unity of 1.11, and a non-zero y intercept of -25.6 whose significance was unrecognized and more often than not ignored. It has recently been demonstrated that the slope and y intercept in this equation are quantitatively determined by several additional physiologic parameters, which in addition to (Na(e)+ K(e))/TBW, play a role both in modulating the [Na(+)](pw) and in the generation of the dysnatremias. Even more remarkably, based only on the theoretical principles of Gibbs-Donnan and osmotic equilibrium, all the physiologic parameters that determine the magnitude of the [Na(+)](pw) can be incorporated into a simple conceptual and mathematical framework that sheds light on a broad of range of seemingly unrelated topics that have heretofore been treated separately clinically, including (1) effect of changes in the mass balance of Na(+), K(+), and H(2)O on the [Na(+)](pw); (2) modulation of [Na(+)](pw) in hyperglycemic states; (3) definition of an isonatric solution; (4) current formulas used to quantitate electrolyte-free water excretion; (5) complex role of K(+) in modulating the [Na(+)](pw); and (6) quantitative analysis of the generation and treatment of the dysnatremias. Moreover, this analysis has also proven to be an indispensable tool for deriving new formulas to aid the clinician in both interpreting the pathogenesis and treating the dysnatremias.

Humans↗
PubMed2000

Qualitative and quantitative analysis of phosphorylated compounds in milk by means of 31P-NMR.

31P-NMR has been tested as a technique for determining the phosphorus content of milk samples in both the inorganic form (Pi) and bonded to caseins as phosphoserine (SerP). 31P-NMR made possible the simultaneous determination of Pi and SerP in approximately 1.7 h. The determination is based on measuring the area under the resonance in question and interpolating in a calibration curve prepared using external standards of known phosphorus contents and prepared in the same manner. The concentration area plots obtained were linear in the ranges 162-1993 mg P/l for Pi and 38-40.2 mg P/l for casein SerP. The repeatability of the method was good. When the same milk samples were analysed by both 31P-NMR and the classic colorimetric method the correlation was good. Polyphosphates added to commercial milk were also detected, as diphosphates. The NMR response for diphosphate was linear between 58 and 576 mg P/l and preliminary results indicated that quantitative analysis could be achieved in commercial milk.

Animals↗
PubMed2006

Quantitative analysis of the oxidative DNA lesion, 2,2-diamino-4-(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-5(2H)-oxazolone (oxazolone), in vitro and in vivo by isotope dilution-capillary HPLC-ESI-MS/MS.

A major DNA oxidation product, 2,2-diamino-4-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-5(2H)-oxazolone (oxazolone), can be generated either directly by oxidation of dG or as a secondary oxidation product with an intermediate of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG). Site-specific mutagenesis studies indicate that oxazolone is a strongly mispairing lesion, inducing approximately 10-fold more mutations than 8-oxo-dG. While 8-oxo-dG undergoes facile further oxidation, oxazolone appears to be a stable final product of guanine oxidation, and, if formed in vivo, can potentially serve as a biomarker of DNA damage induced by oxidative stress. In this study, capillary liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) methods were developed to enable quantitative analysis of both 8-oxo-dG and oxazolone in DNA from biological sources. Sensitive and specific detection of 8-oxo-dG and oxazolone in enzymatic DNA hydrolysates was achieved by isotope dilution with the corresponding 15N-labeled internal standards. Both nucleobase adducts were formed in a dose-dependent manner in calf thymus DNA subjected to photooxidation in the presence of riboflavin. While the amounts of oxazolone continued to increase with the duration of irradiation, those of 8-oxo-dG reached a maximum at 20 min, suggesting that 8-oxo-dG is converted to secondary oxidation products. Both lesions were found in rat liver DNA isolated under carefully monitored conditions to minimize artifactual oxidation. Liver DNA of diabetic and control rats maintained on a diet high in animal fat contained 2-6 molecules of oxazolone per 10(7) guanines, while 8-oxo-dG amounts in the same samples were between 3 and 8 adducts per 10(6) guanines. The formation of oxazolone lesions in rat liver DNA, their relative stability in the presence of oxidants and their potent mispairing characteristics suggest that oxazolone may play a role in oxidative stress-mediated mutagenesis.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1999

Quantitative analysis of R-84760, a selective kappa-opioid receptor agonist, in plasma by liquid chromatography with electrospray ionization tandem mass spectrometry.

A sensitive method for monitoring R-84760, a selective kappa-opioid receptor agonist, in plasma using liquid chromatography with electrospray ionization tandem mass spectrometry was explored. R-84760 and internal standard (I.S., d8-R-84760) were extracted from human or various animal plasmas with ethyl acetate. The analysis was performed by the selected reaction monitoring method, and the precursor-product combinations of m/z 399-328 for R-84760 and m/z 407-328 for I.S. were chosen for quantification. The calibration curve was linear in the range 5-500 pg/ml, and the limit of quantification was 5 pg/ml using 1 ml of human plasma. Pharmacokinetic studies of R-84760 in rats, dogs, and monkeys were performed by this method. The plasma concentration of unchanged form after administration at a trace dosage amount was able to be monitored. Interspecies correlations of pharmacokinetic parameters obtained in animals were utilized to estimate pharmacokinetic behavior in humans. The results showed that it is possible to perform pharmacokinetic studies on R-84760 by this quantitative analysis.

Analgesics↗
PubMed2002

Methylation methods for the quantitative analysis of conjugated linoleic acid (CLA) isomers in various lipid samples.

Precise methylation methods for various chemical forms of conjugated linoleic acid (CLA), which minimize the formation of t,t isomers and allylmethoxy derivatives (AMD) with the completion of methylation, were developed using a 50 mg lipid sample, 3 mL of 1.0 N H(2)SO(4)/methanol, and/or 3 mL of 20% tetramethylguanidine (TMG)/methanol solution(s). Free CLA (FCLA) was methylated with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). CLA esterified in safflower oil (CLA-SO) was methylated with 20% TMG/methanol (100 degrees C, 5 min), whereas CLA esterified in phospholipid (CLA-PL) was methylated with 20% TMG/methanol (100 degrees C, 10 min), followed by an additional reaction with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). Similarly, CLA esterified in egg yolk lipid (CLA-EYL) was methylated by base hydrolysis, followed by reaction with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). These results suggest that for the quantitative analysis of CLA in lipid samples by GC, proper methylation methods should be chosen on the basis of the chemical forms of CLA in samples.

Chromatography, Gas↗
PubMed2002

Quantitative analysis of glomerular type IV collagen alpha3-5 chain expression in children with thin basement membrane disease.

Thin basement membrane disease (TBMD) and Alport syndrome, two forms of childhood nephritis, have generally been considered to be hereditary diseases. In Alport syndrome, several reports have demonstrated pathogenic mutations of the genes encoding type IV collagen alpha3, 4 and/or 5 chain [alpha3, 4 and/or 5(IV)]. Previous immunohistochemical studies indicated that these antigens were absent from the glomerular basement membrane (GBM) in Alport syndrome, whilst a normal labeling pattern was maintained in TBMD. In order to understand the role of the alpha3, 4 and/or 5(IV) antigens in TBMD, we used confocal laser scanning microscopy (CLSM) to examine cryosections of renal biopsies from 12 children with TBMD and 11 control children with IgA nephropathy (IgAN) without proteinuria. All tissue sections were stained with a mixture of FITC-conjugated rat monoclonal antibodies directed against human alpha3(IV), alpha4(IV) or alpha5(IV) and a Texas red-conjugated rat monoclonal antibody raised against human alpha2(IV). CLSM was performed and quantitative analysis of the ratio of the staining signal for alpha3(IV), alpha4(IV) or alpha5(IV) to alpha2(IV) [alpha3(IV), alpha4(IV) or alpha5(IV)/alpha2(IV)] along the GBM was determined. The average number of pixels for alpha3(IV), alpha4(IV) or alpha5(IV)/alpha2(IV) was 3.52 +/- 1.49, 3.54 +/- 1.25 and 1.09 +/- 0.49 in TBMD and 3.62 +/- 1.46, 3.99 +/- 1.53 and 1.77 +/- 0.47 in control subjects, respectively. Statistical analysis indicated that alpha5(IV)/alpha2(IV) ratio was significantly lower (p < 0.01) in children with TBMD compared to controls. These findings raise the possibility that TBMD might be caused by an abnormality of the alpha5(IV) antigen along the GBM.

Adolescent↗
PubMed2000

Qualitative and quantitative analysis of embryonic pulmonary vessel formation.

Vessel formation in the lung has been described as occurring by two mechanisms: proximal, or branch, pulmonary arteries develop via angiogenesis; and distal, smaller vessels form by vasculogenesis. Connections between the proximal and distal vessels establish the final vascular network. The preponderance of vessel formation has been suspected to occur during the canalicular stage of lung development. To test these hypotheses, reporter gene expression under control of the regulatory domain of fetal liver kinase-1 (flk), an early endothelial cell-specific marker, was used to evaluate mouse lungs from embryonic day 10.5 (E10.5) through 2 wk postnatal age. Morphologic assessment was performed after histochemical staining, and quantification of vessel development by a chemiluminescent assay was compared with overall embryonic lung growth. LacZ expression under flk promoter control allowed: (1) early identification of differentiating endothelial cells of the branch pulmonary arteries; (2) visualization of distal vessels forming in the lung mesenchyme (primary capillary network) with subsequent remodeling; (3) recognition of early continuity between proximal and distal vessels, occurring by E10.5; and (4) assessment of developing pulmonary veins and venous confluence. Quantitative analysis revealed increased flk regulated beta-galactosidase (beta-gal) activity of 12 ng beta-gal/lung at E12.5 to 3,215 ng beta-gal/lung at 2 wk, which corresponded to overall lung growth during this period as shown by an increase in total protein content per lung from 35 microg at E12.5 to 6,456 microg at 2 wk after birth. We identified endothelial cell precursors of the developing pulmonary vasculature before vessel lumen formation. Continuity between the proximal pulmonary artery and vessels forming in the distal mesenchyme was present even at the earliest stage evaluated, suggesting endothelial cell differentiation at the site of vessel formation (i.e., vasculogenesis) as occurs with development of the aorta. Finally, we demonstrated that lung vessel development was not accentuated during the canalicular stage, but occurred at all stages and directly corresponded to overall lung growth.

Animals↗
PubMed2001

Quantitative analysis of desmosterol, cholesterol and cholesterol sulfate in semen by high-performance liquid chromatography.

A simple, rapid and accurate method to separate and quantify cholesterol, desmosterol and cholesterol sulfate in human spermatozoa and seminal plasma (SP) is described. This high-performance liquid chromatographic procedure is based on reversed-phase chromatography on a Inertsil ODS2 5 microm silica column with a binary gradient of mixtures of chloroform-methanol and chloroform-methanol-water as the mobile phase at a flow-rate of 0.25 ml/min. Sterols are separated with good resolution and high reproducibility. The eluted sterols are quantified using a light-scattering (mass) detector. As little as 64, 64 and 68 pmol of cholesterol, desmosterol and cholesterol sulfate, respectively, can be quantified under these conditions. Cholesterol is the predominant sterol both in spermatozoa (107+/-7 nmol/10(8) spermatozoa) and SP (0.83+/-0.10 micromol/ml) whereas the concentrations of desmosterol were 38+/-6 nmol/10(8) in spermatozoa and 0.18+/-0.02 micromol/ml in SP. Cholesterol sulfate represents about 6% of total cholesterol in the spermatozoa and SP. In conclusion, this method offers interesting perspectives for the quantitative analysis of these sterols not only in semen, but also in other biological samples.

Cholesterol↗
PubMed1987

[A new technique for proximal esophagography and quantitative analysis of pharyngeal function].

The roentgenologic examination of the upper esophagus in somewhat difficult due to the rapid passage of barium. Therefore we designed a new technique for proximal esophagography, using magnetic video disc recorder and multiformat camera (VDR-MC technique). The video signal from fluoroscopic unit is led to video disc recorder (VDR) and after the examination have been finished the recorded images are transferred into multiformat camera, and then the images are copied sequentially on a sheet film VDR have a storage capacity, 600 frames per 20 seconds. The sequential pictures of barium swallowing in one deglutition movement are shown as the time-intervals of each 0.03 seconds on a sheet film. The movement of barium bolus in one deglutition will be demonstrated exactly and except any failure. This working process of VDR-MC technique in very simple and convenient, and when the reading and diagnosis of X-ray appearances, we can easily compare with the changes of each image. This is a characteristic merit of new technique. In order to examine the function of deglutition we designed a new technique by means of the dynamic pharyngo-esophagrams as before. The recorded dynamic images are transferred into multiformat camera and copied on a sheet film by the intervals of 0.03 seconds in turn. Viewing these sequential images the each measuring points are determined ane the barium transit times are calculated from the number of frames, and then transferred to the time in millisecond unit. According to the results of experiment, the measured values well correspond to that by EMG on the pharyngeal movement of deglutition. These quantitative analysis on the pharyngeal function and morphological diagnosis will be performed in easy procedure at the same time. The outline of the discussion about the advantages of this technique is as follows; The performance of the examination by new technique will be done with extreme easy. A difficult examination will be performed without failure and finished in a short time successfully. We can examine enough the patients who are not able to understand the doctor's indication, for example children and patients having hard hearing. In comparison with cinefluorographic unit, development of films, patient's position, observation and copy of images and storage of film, became extremely easy. A quantitative measurement on pharyngeal function was designed and the reproducibility of measurements was given proof.

Adult↗
PubMed2006

Quantitative analysis of immunofluorescent punctate staining of synaptically localized proteins using confocal microscopy and stereology.

We established a protocol for the immunofluorescent detection of glutamate receptor subunits at synaptic sites using laser scanning confocal microscopy and stereological procedures. An in vitro model of eyeblink classical conditioning from turtles was used for this study. Triple-labeling of the presynaptic marker synaptophysin, the NR1 subunit of NMDA receptors, and the GluR4 subunit of AMPA receptors was performed on pseudoconditioned (control) and conditioned in vitro brain stem preparations in which punctate staining for each individual protein, as well as for the colocalization of GluR4 and NR1 with synaptophysin, was analyzed. For every tissue section analyzed, images of two consecutive optical planes were taken using confocal microscopy. Protein puncta were counted in one optical section (sample section) if they were not present in the optical section immediately above the sample section (look-up section). We found a significant increase in the colocalization of GluR4-containing AMPA receptors with synaptophysin after conditioning compared with the control group. Colocalization of NR1 subunits with synaptophysin was unchanged after conditioning. The described protocol, therefore, can be used for the quantitative analysis of changes in synaptic localization of different types of proteins. The protocol is designed to provide a more accurate and uniform approach in studying receptor trafficking during various forms of synaptic plasticity.

Animals↗
PubMed1999

Reduced levels of poly(ADP-ribosyl)ation result in chromatin compaction and hypermethylation as shown by cell-by-cell computer-assisted quantitative analysis.

The unmethylated status of the CpG islands is important for gene expression of correlated housekeeping genes since it is well known that their methylation inhibits transcription process. An interesting question that has been discussed but not solved is how the CpG islands maintain their characteristic unmethylated status even though they are rich in CpG dinucleotides. Our previous in vitro and in vivo research has shown that poly(ADP-ribosyl)ation is involved in protecting CpG dinucleotides from full methylation in genomic DNA and that a block of poly(ADP-ribosyl)ation is also involved in modifying the methylation pattern in the promoter region of Htf9 housekeeping gene. In this study we locked for cytological evidence that in the absence of an active poly(ADP-ribosyl)ation the DNA methylation pattern in L929 and NIH/3T3 mouse fibroblast cell lines is altered. For this purpose, differences in the methylation levels of interphase nuclei from control and treated cultures of two murine cell lines preincubated with 2 mM 3-aminobenzamide, an inhibitor of poly(ADP-ribosyl)ation, were measured in individual cells after indirect immunolabeling with anti-5MeC antibodies. The quantitative analysis allowed us to demonstrate that blocking of the poly(ADP-ribosyl)ation results in a higher number, size, and density of antibody binding regions in treated cells when compared to the controls. Analogously, sequential Giemsa staining and indirect immunolabeling of the same slides showed the heterochromatic regions colocalized with the extended methyl-rich domains.

3T3 Cells↗
PubMed1998

Quantitative analysis of a synthetic adjuvant by an immunoassay.

Antibodies against a sulpholipo-derivative of synthetic polysucrose (SL-Ficoll) were prepared with the purpose of developing a detection system for this adjuvant component. SL-Ficolls with polysucrose backbones of 400 kDa (SL-Ficoll400) or 22 kDa (SL-Ficoll22) were not immunogenic. However, SL-Ficoll22 conjugated to bovine serum albumin (SL-Ficoll22-BSA) induced high levels of specific antibodies against SL-Ficoll in mice as determined by an indirect ELISA with either SL-Ficoll400 or SL-Ficoll22 as coating antigen. The specificity of the antibodies was analysed further in a blocking ELISA with SL-Ficoll400 as coat. Dose-dependent inhibition of the ELISA titre was obtained with SL-Ficoll22 and SL-Ficoll400 and the concentration causing 50% inhibition (IC50) was < 1 microg/ml. Non-derivatised polysucrose (Ficoll400) and compounds lacking either lipid or sulphate were not recognised (IC50 > 1000 microg/ml). The reaction of SL-Ficoll400-derivatives with antibodies increased with increasing sulphate and lipid content and maximal inhibition was produced by compounds with a composition similar to the SL-Ficoll22 used for immunisation. Quantitative analysis of SL-Ficoll400 in adjuvant formulations comprising SL-Ficoll400 incorporated in a squalane-in-water emulsion revealed high recovery and sufficient precision. From these data, we conclude that specific antibodies are generated against the synthetic SL-Ficoll400 and that this component of a novel adjuvant formulation can be quantified by an immunoassay.

Adjuvants, Immunologic↗
PubMed2003

[Quantitative analysis of contrast enhanced MRI of the inferior alveolar nerve in inflammatory changes of the mandible].

PURPOSE: To evaluate the role of contrast enhanced MRI in quantifying signal changes of the inferior alveolar nerve following inflammatory changes of the mandible. MATERIAL AND METHODS: 30 patients with inflammatory changes of the mandible underwent MRI of the face. Both sides of the mandible, the affected as well as the unaffected healthy side were evaluated retrospectively. Regions of interest were placed at 5 defined places on both sides to assess signal intensity before and after intravenous application of paramagnetic contrast agent. The results of the measurements were compared between the healthy and the affected side (t-test, p < 0.05) and correlated with clinical findings (t-test, p < 0.05). RESULTS: All patients with hypesthesia of the inferior alveolar nerve in areas of the lips or chin (n = 4) showed a marked increase in signal intensity from 35 % to 83 % distal to the inflammatory process. Patients without sensitivity disorders showed less increase in signal intensity with a maximum of 51 % distal to the inflammatory process. In nearly all patients no contrast enhancement was observed distal to the first molar on the unaffected side. CONCLUSIONS: Quantitative analysis of contrast enhanced MRI of the neurovascular bundle is able to show pathologic mandibular lesions. In case of inflammatory changes of the mandible the neurovascular bundle is able to show pathologic mandibular lesions. In case of inflammatory changes of the mandible, the neurovascular bundle shows a significant increase in signal intensity distal to the lesion compared to the unaffected healthy side of the mandible.

Adolescent↗
PubMed1991

Quantitative analysis of platelet activating factor treated with pentafluorobenzoyl chloride using gas chromatography/negative ion chemical ionization mass spectrometry.

To confirm that platelet activating factor (PAF) plays an important role as a mediator in acute inflammation and allergic reaction, it is necessary to develop a more sensitive and stable method for measuring trace amounts of PAF in various biological samples. For this reason, the authors have adapted gas chromatography/negative ion chemical ionization mass spectrometry (GC/NICI-MS) (developed by Ramesha and Pickett in 1985) by employing an SPB-1 column and isobutane as the reagent gas. Furthermore, with this method the authors attempted an investigation of the time course of hexadecyl- and octadecyl-PAF production and release from human polymorphonuclear leukocytes (PMNs) stimulated by Ca-ionophore A23187. PMNs were obtained from venous blood from a human donor by centrifugation and were stimulated by 5 microM of Ca-ionophore A23187. PAF was purified using a SEP-PAK silica column and thin layer chromatography, and then was hydrolyzed with phospholipase C. The extract was treated with pentafluorobenzoyl chloride. Using 1-O-hexadecyl-2-acetyl (perdeuterated)-sn-phosphocholine) as an internal standard, the following results were obtained: The standard curve for this quantitative analysis was linear with a correlation coefficient of 0.9997 from 1 pg to 200 ng. The authors assumed that quantities as low as a few picograms of PAF could be measured by the method. The production of hexadecyl-PAF in the cell pellet peaked (8.1 +/- 1.34 ng/10(7) cells) at 2 min after stimulation and that in the supernatant peaked (6.3 +/- 0.97 ng/10(7) cells) at approximately 7 min after stimulation. Octadecyl-PAF could not be detected in this experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzoates↗
PubMed1995

A quantitative analysis of the dendritic organization of pyramidal cells in the rat hippocampus.

The three dimensional organization of the dendritic trees of pyramidal cells in the rat hippocampus was investigated using intracellular injection of horseradish peroxidase in the in vitro hippocampal slice preparation and computer-aided reconstruction. The total dendritic length, dendritic length in each of the hippocampal laminae, and the number of dendritic branches were measured in 20 CA1 pyramidal cells, 7 neurons in CA2 and 20 CA3 pyramidal cells. The total dendritic length of CA3 pyramidal cells varied in a consistent fashion depending on their position within the field. Cells located close to the dentate gyrus had the smallest dendritic trees which averaged 9,300 microns in total length. Cells in the distal part of CA3 (near CA2) had the largest dendritic trees, averaging 15,800 microns. The CA2 field contained cells which resembled CA3 pyramidal cells in most respects except for the absence of thorny excrescences on their proximal dendrites. There were also smaller pyramidal cells that resembled CA1 neurons. CA1 pyramidal cells tended to be more homogeneous. Pyramidal neurons throughout the transverse extent of CA1 had a total dendritic length on the order of 13,500 microns. The quantitative analysis of the laminar distribution of dendrites demonstrated that the stratum oriens and stratum radiatum contained significant portions of the pyramidal cell dendritic trees. In Ca3, for example, 42-51% of the total dendritic length was located in stratum oriens; about 34% of the dendritic tree was located in stratum radiatium. The amount of dendritic length in stratum lacunosum-moleculare of CA3 varied depending on the location of the cell. Many CA3 cells located within the limbs of the dentate gyrus, for example, had no dendrites extending into stratum lacunosum-moleculare whereas those located distally in CA3 had about the same percentage of their dendritic tree in stratum lacunosum-moleculare as in stratum radiatum. In CA1, nearly half of the dendritic length was located in stratum radiatum, 34% was in stratum oriens and 18% was in stratum lacunosum-moleculare. These studies identified distinctive dendritic branching patterns, in the stratum radiatum and stratum lacunosum-moleculare, which clearly distinguished CA3 from CA1 neurons.

Animals↗
PubMed1984

Mathematical model of biliary lipid secretion: a quantitative analysis of physiological and biochemical data from man and other species.

We propose a simple mathematical model to account for the coupling of secretion rates of bile salts, lecithin, and cholesterol into bile. The model assumes that: 1) molecules of "biliary" lecithin and cholesterol enter a functional compartment located in the endoplasmic reticulum of the hepatocyte from which they are secreted into bile, and in the case of cholesterol, also catabolized to bile salts; 2) the rates at which lecithin and cholesterol enter the "secretory" compartment are regulated independently by feedback loops that control their synthesis and/or uptake; 3) lecithin secretion is coupled by an unknown transport mechanism, possibly micellar or vesicular, to the flux of bile salts passing through the compartment; 4) cholesterol secretion is coupled by a similar mechanism to lecithin secretion and not to bile salt secretion directly; and 5) bile salt synthesis is proportional to the cholesterol content of the compartment. The model predicts that in the steady state the dependences, lecithin secretion vs bile salt secretion; cholesterol secretion vs lecithin secretion; and cholesterol secretion vs bile salt secretion, will all have the form of rectangular hyperbolae. Four independent parameters related to the postulated mechanisms of biliary lipid synthesis, uptake, and transport determine the quantitative features of these hyperbolae. These four "secretion parameters" also determine how the biliary lipid composition of hepatic and "fasting" gallbladder bile varies with bile salt secretion rate. A quantitative analysis of biochemical and physiological data on biliary lipid secretion in rat, dog, and man confirms the general predictions of the model. Deductions of the secretion parameters are made for each species and are compared with other relevant data on biliary lipid metabolism. From this analysis, we offer new insights into: i) the species differences in biliary lipid secretion and bile composition; ii) the influence of obesity on biliary lipid secretion in man; and iii) the causes of cholesterol super-saturation in fasting gallbladder bile.

Animals↗
PubMed2000

Quantitative analysis of aldolase A mRNA in liver discriminates between hepatocellular carcinoma and cirrhosis.

BACKGROUND: Chronic liver diseases can progress to cirrhosis and to hepatocellular carcinoma. Timely and unequivocal recognition of the neoplastic evolution of cirrhosis is critical. To this aim, we used a noncompetitive reverse transcription-PCR procedure to analyze aldolase A mRNA in liver tissue from patients with chronic liver diseases at different stages. METHODS: We studied 12 patients with hepatocellular carcinoma, 19 patients affected by chronic hepatitis C or cirrhosis, and 7 healthy controls. Aldolase A mRNA was reverse-transcribed to cDNA, which was then amplified by PCR. The amplified segments were "read" with a novel dot-blot procedure. A calibrator with the same sequence, synthesized in vitro using a T7 phage promoter, was processed at scalar dilutions in parallel to the target samples to generate a calibration curve and so quantify the target mRNA (detection limit, 0.03 amol; linearity spanning five orders of magnitude). RESULTS: Aldolase A mRNA was approximately 10-fold higher in liver biopsies from patients with hepatocellular carcinoma vs patients with chronic hepatitis C or cirrhosis, and healthy individuals. Furthermore, aldolase A mRNA concentrations were 1.2- to 21.3-fold higher in 12 liver biopsies compared with the paired surrounding cirrhotic tissue. CONCLUSIONS: The quantitative analysis of liver tissue aldolase A mRNA differentiates between nonneoplastic chronic liver diseases and hepatocellular carcinoma, which suggests that it has diagnostic potential.

Carcinoma, Hepatocellular↗