&lt;i&gt;In vivo&lt;/i&gt; relationship between the clinical epicondylar axis and the anterior pelvic plane in normal subjects

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

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Evidence for an Increased Generation of Prostacyclin in the Microvasculature and an Impairment of the Platelet α-Granule Release in Chronic Renal Failure

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647030 ◽

1988 ◽

Vol 60 (02) ◽

pp. 205-208 ◽

Cited By ~ 21

Author(s):

Paul A Kyrle ◽

Felix Stockenhuber ◽

Brigitte Brenner ◽

Heinz Gössinger ◽

Christian Korninger ◽

...

Keyword(s):

Renal Failure ◽

Chronic Renal Failure ◽

Blood Clotting ◽

Normal Subjects ◽

Chronic Uraemia ◽

Wall Interaction ◽

End Stage ◽

Granule Release

SummaryThe formation of prostacyclin (PGI2) and thromboxane A2 and the release of beta-thromboglobulin (beta-TG) at the site of platelet-vessel wall interaction, i.e. in blood emerging from a standardized injury of the micro vasculature made to determine bleeding time, was studied in patients with end-stage chronic renal failure undergoing regular haemodialysis and in normal subjects. In the uraemic patients, levels of 6-keto-prostaglandin F1α (6-keto-PGF1α) were 1.3-fold to 6.3-fold higher than the corresponding values in the control subjects indicating an increased PGI2 formation in chronic uraemia. Formation of thromboxane B2 (TxB2) at the site of plug formation in vivo and during whole blood clotting in vitro was similar in the uraemic subjects and in the normals excluding a major defect in platelet prostaglandin metabolism in chronic renal failure. Significantly smaller amounts of beta-TG were found in blood obtained from the site of vascular injury as well as after in vitro blood clotting in patients with chronic renal failure indicating an impairment of the a-granule release in chronic uraemia. We therefore conclude that the haemorrhagic diathesis commonly seen in patients with chronic renal failure is - at least partially - due to an acquired defect of the platelet a-granule release and an increased generation of PGI2 in the micro vasculature.

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ÉTUDES IN VIVO SUR LE MÉTABOLISME DES ANDROGÉNES APRES ADMINISTRATION DE STÉROÏDES INHIBITEURS DE L'OVULATION

Acta Endocrinologica ◽

10.1530/acta.0.0500131 ◽

1965 ◽

Vol 50 (1) ◽

pp. 131-144 ◽

Cited By ~ 1

Author(s):

P. Mauvais-Jarvis ◽

M. F. Jayle ◽

J. Decourt ◽

J. Louchart ◽

J. Truffert

Keyword(s):

Luteinizing Hormone ◽

Urinary Excretion ◽

Normal Subjects ◽

Hormone Activity ◽

Testosterone Production ◽

Normal Men ◽

Ethinyl Oestradiol

ABSTRACT Normal subjects and hirsute women with micropolycystic ovaries were treated with ethinyl-oestrenol + 3-methoxy-ethinyl-oestradiol (Lyndiol®), in view of studying the action of this compound on the production of androgens and on the urinary excretion of their metabolites. In normal men, the production of testosterone and the excretion of androsterone and aetiocholanolone are suppressed, whereas the excretion of other 17-ketosteroids and the production of dehydroepiandrosterone sulphate are unchanged. Moreover, the luteinizing hormone activity (LH) in plasma is depressed. It seems that the preparation inhibits specifically the testicular androgen production, by suppressing the hypothalamo-hypophyseal control of LH. Testosterone production and urinary 17-ketosteroid excretion are modified in the same way in women with Stein-Leventhal's syndrome. Physiopathological and therapeutical implications which come from these results are discussed.

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In vivo quantification of pulmonary beta-adrenoceptor density in humans with (S)-[11C]CGP-12177 and PET

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.2.559 ◽

1993 ◽

Vol 75 (2) ◽

pp. 559-565 ◽

Cited By ~ 27

Author(s):

J. Ueki ◽

C. G. Rhodes ◽

J. M. Hughes ◽

R. De Silva ◽

D. C. Lefroy ◽

...

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Specific Activity ◽

Regional Distribution ◽

High Specific Activity ◽

Normal Subjects ◽

Normal Male ◽

Tissue Density ◽

Beta Adrenoceptor ◽

Cgp 12177

The in vivo regional distribution of pulmonary beta-adrenoceptors was imaged and quantified in humans with the hydrophilic beta-adrenoceptor antagonist (S)-CGP-12177 labeled with carbon-11 [(S)-[11C]CGP-12177] and positron emission tomography (PET). Six normal male volunteers and eight patients with hypertrophic cardiomyopathy were studied. PET scanning consisted of transmission (tissue density), C15O (blood volume), and (S)-[11C]CGP-12177 (beta-adrenoceptor) emission scans. High-specific-activity (S)-[11C]-CGP-12177 (7.1 +/- 2.0 micrograms, 6.5 +/- 2.1 GBq/mumol) was given intravenously followed by a low-specific-activity (S)-[11C]CGP-12177 injection (34.0 +/- 4.8 micrograms, 2.3 +/- 0.8 GBq/mumol). Binding capacity (Bmax) was calculated in each region of interest as picomoles per gram by normalizing it to the local extravascular tissue density. In normal subjects, average Bmax for all regions of interest was 14.8 +/- 1.6 (SD) pmol/g, which is similar to previously reported in vitro values. In both groups there were no differences in beta-adrenoceptor density between peripheral and central regions nor between right and left lungs. In patients with hypertrophic cardiomyopathy, extravascular tissue density was 24% higher than in normal subjects; Bmax per milliliter thoracic volume was correspondingly higher but was not different from that in normal subjects when expressed per gram tissue (15.8 +/- 2.6 pmol/g). These data suggest that in vivo beta-adrenoceptor density may be quantifiable in humans with the use of PET. This should offer a means to study physiological regulation through repeat measurements.

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In vivo characterization of the transitional bronchioles by aerosol-derived airway morphometry

Journal of Applied Physiology ◽

10.1152/jappl.1999.87.3.920 ◽

1999 ◽

Vol 87 (3) ◽

pp. 920-927 ◽

Cited By ~ 4

Author(s):

Kirby L. Zeman ◽

Gerhard Scheuch ◽

Knut Sommerer ◽

James S. Brown ◽

William D. Bennett

Keyword(s):

Ex Vivo ◽

Normal Subjects ◽

Characteristic Line ◽

Chronic Obstructive ◽

Obstructive Pulmonary Disease ◽

Lung Capacity ◽

Single Breath ◽

In Vivo Characterization

Effective airway dimensions (EADs) were determined in vivo by aerosol-derived airway morphometry as a function of volumetric lung depth (VLD) to identify and characterize, noninvasively, the caliber of the transitional bronchiole region of the human lung and to compare the EADs by age, gender, and disease. By logarithmically plotting EAD vs. VLD, two distinct regions of the lung emerged that were identified by characteristic line slopes. The intersection of proximal and distal segments was defined as VLDtransand associated EADtrans. In our normal subjects ( n = 20), VLDtrans [345 ± 83 (SD) ml] correlated significantly with anatomic dead space (224 ± 34 ml) and end of phase II of single-breath nitrogen washout (360 ± 53 ml). The corresponding EADtranswas 0.42 ± 0.07 mm, in agreement with other ex vivo measurements of the transitional bronchioles. VLDtrans was smaller (216 ± 64 ml) and EADtrans was larger (0.83 ± 0.04 mm) in our patients with chronic obstructive pulmonary disease ( n = 13). VLDtrans increased with age for children (age 8–18 yr; P = 0.006, n = 26) and with total lung capacity for age 8–81 yr ( P < 0.001, n = 61). This study extends the usefulness of aerosol-derived airway morphometry to in vivo measurements of the transitional bronchioles.

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Measurements of the jejunal unstirred layer in normal subjects and patients with celiac disease

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1996.270.3.g487 ◽

1996 ◽

Vol 270 (3) ◽

pp. G487-G491 ◽

Cited By ~ 4

Author(s):

A. Strocchi ◽

G. Corazza ◽

J. Furne ◽

C. Fine ◽

A. Di Sario ◽

...

Keyword(s):

Celiac Disease ◽

Layer Thickness ◽

Villous Atrophy ◽

Normal Subjects ◽

Unstirred Layer ◽

Maximal Velocity ◽

Normal Rat ◽

Kinetics Of

Normal intestinal absorption of nutrients requires efficient luminal mixing to deliver solute to the brush border. Lacking such mixing, the buildup of thick unstirred layers over the mucosa markedly retards absorption of rapidly transported compounds. Using a technique based on the kinetics of maltose hydrolysis, we measured the unstirred layer thickness of the jejunum of normal subjects and patients with celiac disease, as well as that of the normal rat. The jejunum of humans and rats was perfused with varying maltose concentrations, and the apparent Michaelis constant (Km) and maximal velocity (Vmax) of maltose hydrolysis were determined from double-reciprocal plots. The true Km of intestinal maltase was determined on mucosal biopsies. Unstirred layer thickness was calculated from the in vivo Vmax and apparent Km and the in vitro Km of maltase. The average unstirred layer thickness of 11 celiac patients (170 micron) was seven times greater than that of 3 controls (25 micron). The unstirred layer of each celiac exceeded that of the controls. A variety of factors could account for the less efficient luminal stirring observed in celiacs. Although speculative, villous contractility could be an important stirring mechanism that would be absent in celiacs with villous atrophy. This speculation was supported by the finding of a relatively thick unstirred layer (mean: 106 micron) in rats, an animal that lacks villous contractility. Because any increase in unstirred layer slows transport of rapidly absorbed compounds, poor stirring appears to represent a previously unrecognized defect that could contribute to malabsorption in celiac disease and, perhaps, in other intestinal disorders.

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Cerebral Glucose and Dopa Metabolism in Movement Disorders

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100037896 ◽

1987 ◽

Vol 14 (S3) ◽

pp. 448-451 ◽

Cited By ~ 7

Author(s):

W.R. Wayne Martin ◽

Michael R. Hayden

Keyword(s):

At Risk ◽

Glucose Metabolism ◽

Normal Subjects ◽

Cerebral Glucose Metabolism ◽

Nigrostriatal Pathway ◽

Age Related ◽

Positron Emission ◽

Asymptomatic Individuals ◽

Regional Cerebral Glucose Metabolism

ABSTRACT:The development of positron emission tomography (PET) has enabled us to perform in vivo measurements of certain aspects of regional cerebral function. Regional cerebral glucose metabolism may be readily quantified with [18F] fluoro-2-deoxyglucose (FDG) and presynaptic dopaminergic function may be studied with the labelled dopa analog 6-[18F] fluoro-L-dopa. We have applied a model to the analysis of 6-FD/PET data with which in vivo age-related changes in dopaminergic function may be demonstrated in normal subjects. With this technique, we have studied a series of asymptomatic MPTP-exposed subjects and have shown evidence of subclinical nigrostriatal pathway damage. Studies of regional cerebral glucose metabolism with FDG in early Huntington's disease have shown a characteristic impairment in caudate function which precedes the development of caudate atrophy. In addition, some asymptomatic individuals who are at risk for HD have caudate hypometabolism. We feel that, at the present time, PET provides information which is complementary to the clinical examination in establishing a diagnosis of HD. In the future these studies may also help in the investigation of at risk individuals

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Analysis of free and protein-bound nitrotyrosine in human plasma by a gas chromatography/mass spectrometry method that avoids nitration artifacts

Biochemical Journal ◽

10.1042/bj3450453 ◽

2000 ◽

Vol 345 (3) ◽

pp. 453-458 ◽

Cited By ~ 49

Author(s):

Matthew T. FROST ◽

Barry HALLIWELL ◽

Kevin P. MOORE

Keyword(s):

Reactive Nitrogen Species ◽

Plasma Proteins ◽

Biological Fluids ◽

Plasma Concentrations ◽

Normal Subjects ◽

Gas Chromatography Mass Spectrometry ◽

Highly Sensitive ◽

Acidic Conditions ◽

First Time

Measurement of nitrotyrosine in biological fluids and tissues is increasingly being used to monitor the production of reactive nitrogen species in vivo. The detection of nitrotyrosine in vivo has been reported with the use of a variety of methods including immunoassay, HPLC and GLC/MS. The validity of HPLC and immunoassays have been questioned with regard to their selectivity and sensitivity limits. In principle, the measurement of nitrotyrosine by GLC/MS permits a highly specific, highly sensitive and fully quantitative assay. The nitration of tyrosine under acidic conditions in the presence of nitrite is well documented. Derivatization for the full quantification of nitrotyrosine by using GLC/MS can lead to the artifactual nitration of tyrosine if performed under acidic conditions in the presence of nitrite. We describe a novel alkaline method for the hydrolysis and derivatization of nitrotyrosine and tyrosine, and demonstrate its applicability to the measurement of plasma concentrations of both free and protein-bound nitrotyrosine and tyrosine. A detection limit of 1 pg for nitrotyrosine and 100 pg for tyrosine has been achieved. Our method allows, for the first time, the analysis of free and protein-bound nitrotyrosine and tyrosine in biological samples. The plasma concentrations (means±S.E.M.) of free tyrosine and nitrotyrosine in eight normal subjects were 12±0.6 μg/ml and 14±0.7 ng/ml respectively. Plasma proteins contained tyrosine and nitrotyrosine at 60.7±1.7 μg/mg and 2.7±0.4 ng/mg respectively.

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