Pharmacokinetics of oestriol after repeated oral administration to dogs

The aim of the present study was to investigate the pharmacokinetics of oestriol in plasma in the dog after repeated oral administration of oestriol tablets, a preparation intended for the treatment of urinary incontinence in the bitch. The study was performed in six healthy, entire, adult female beagle dogs. The bitches were treated once daily...

Recognition properties of V3-specific antibodies to V3 loop peptides derived from HIV-1 gp120 presented in multiple conformations

To identify structural constraints and amino acid sequences important for antibody recognition of the third variable domain (V3) of HIV-1 gp120, we have studied the solution conformation of three 35-mer circular V3 loop peptides derived from HIV-1 strains which differ in syncytium- (SI) and non-syncytium-inducing (NSI) capacity. In addition to...

Analysis by mass spectrometry of POMC-derived peptides in amphibian melanotrope subpopulations

We have previously shown that the melanotrope population of the pituitary intermediate lobe of Rana ridibunda is composed of two subpopulations, of low (LD) and high density (HD), that show distinct ultrastructural features and display different synthetic and secretory rates. To investigate whether LD and HD melanotrope cells also differ in...

Effect of protein and protein-free energy intake on plasma concentrations of insulin-like growth factor I and thyroid hormones in preruminant calves

We conducted two experiments with preruminant calves weighing 80 to 240 kg to study the long-term nutritional regulation of circulating IGF-I, thyroxine (T4), and triiodothyronine (T3). The two experiments were similar in design but were performed with calves of two live weight ranges: 80 to 160 kg (Exp. 1) and 160 to 240 kg (Exp. 2). In each...

Feminisation of young males of the common carp, Cyprinus carpio, exposed to 4-tert-pentylphenol during sexual differentiation

In recent years, a hierarchy of techniques has become available for detecting chemicals which may cause endocrine

Use of biosensors for rapid drug residue analysis without sample deconjugation or clean-up: A possible way forward

The drug salbutamol (SBL) is a β-agonist that may be used illegally as an animal growth promoter. SBL is also a good example of a drug which is excreted in the form of glucuronides and sulfates. Such metabolites cause complexities in analysing for the presence of drug residues. In the majority of cases a process of deconjugation and sample clean...

Lack of interaction between orlistat and oral contraceptives

Objectives: Orlistat, a potent and selective inhibitor of gastrointestinal lipases, is designed for the treatment of obesity. A double-blind, randomised, placebo-controlled, 2-way crossover study investigated the possible influence of orlistat on the ovulation-suppressing action of combination oral contraceptives (OC). Methods: After an 8-day...

Changes of some vitamin levels during and after normal pregnancy

Most vitamin status parameters change significantly during pregnancy. A number of factors have been associated with this hypovitaminaemia of pregnancy. From our data, it was concluded that the initial value of a vitamin status parameter was by far the main determinant of the changes of vitamin levels during pregnancy: the higher the value, the...

Magnetic resonance imaging compared with hormonal effects and histopathology of estrogen-induced pituitary lesions in the rat

Estrogen-induced pituitary lesions in rats were studied in time-sequence experiments using magnetic resonance imaging (MRI), hormone determinations and light microscopy. The main purpose of the study was to evaluate the usefulness of MRI in comparison with conventional biochemical and histopathological methods for detecting the pituitary lesions...

Determination of progesterone by liquid chromatography - mass spectrometry using a moving-belt interface and isotope dilution

Progesterone can be determined rapidly and accurately with the method presented, using isotope dilution LC-MS with a moving-belt interface. Deactivation is very useful in that it minimizes belt memory effects and optimizes belt desorption characteristics. Since the moving-belt properties were found to change during time with respect to the...

Serum 25-hydroxycholecalciferol levels in women using oral contraceptives

A study has been made of the serum 25-hydroxycholecalciferol (25-HCC) levels in six groups of women. Significant differences were found between the one pregnant group and the two reference groups as well as between the one pregnant group and two of the three groups using oral contraceptives. No significant differences were found between the...

Radioimmunoassay for pancreatic glucagon based on specific derivatisation of the hormone

A specific glucagon antiserum was generated in rabbits using a derivatisation of the methionine residue in glucagon. A sensitive and specific assay for glucagon has been developed. Interference with the assay system by plasma factors was abolished by both extraction of plasma samples and the production of glucagon-free plasma for each individual...

Localization of murine mammary tumor virus polypeptides on the surface of tumor cells

Antisera raised in rabbits against purified components gp52, p28 and p12 of murine mammary tumor virus (MuMTV) were first characterized by means of immunodiffusion, immunoelectrophoresis and radioimmunoassay. No significant crossreactivity could be detected. The 3 polypeptides were detected by means of these antisera in the cytoplasm of murine...