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Biomedical subjects

T Greve

Publications and source records attributed to T Greve.

157 records · Page 9Linked to original sources
PubMed1978

Estimating adrenal cortical function in dogs with ACTH.

The peripheral blood response to intramuscular injection of 10 units ACTH in dogs was investigated because no experimental evidence for the standardization of this procedure for clinical use was available. Following the injection of ACTH in sodium chloride solution, neutrophilia, monocytosis, eosinopenia, and lymphopenia occurred. With the exception of eosinopenia, the greatest change in the concentration of each cell type in peripheral blood occurred between 2 and 4 hours post injection. The maximum change in eosinophil numbers occurred between 4 and 6 hours post injection. When all cell types were considered, 4 hours post injection was the most suitable time to measure the cellular response in peripheral blood in dogs which respond to ACTH. The data indicate that change in the ratio of neutrophils to lymphocytes (N/L) prior to and at 2 to 4 hours after ACTH injection in normal dogs was a sensitive index of response and occured sooner than eosinopenia. The extent of change in the N/L ratio was such that accuracy in interpretation could be obtained by counting as few as 40 cells.

Adrenal Cortex↗
PubMedDate not supplied

Non-invasive identification of chemical compounds by energy dispersive X-ray fluorescence spectrometry, combined with chemometric methods of data evaluation.

Chemicals from customers' returns have to be analyzed before they can be reused as raw materials in production. A procedure for non-invasive qualitative analysis of compounds in a closed container based on energy dispersive X-ray fluorescence (EDXRF) spectrometry is described. EDXRF was chosen as method for noninvasive analysis of chemicals through PE bottle walls without opening the bottle. This analysis aims for a quick proof of correspondence between the declaration of a reagent on the label of the bottle and its content. This analytical result cannot be achieved by a mere evaluation of characteristic element lines in EDXRF-spectra in combination with the method of matrix correction or the method of mean atomic number. These methods take into account only a small part of the total information available in an X-ray spectrum. It is shown here that valuable additional information is extractable from the spectral ranges of the Compton-scattering and Rayleigh-scattering areas by the use of methods of multivariate data analysis, especially by principle component analysis (PCA). Regularized discriminant analysis (RDA) was employed to establish a classification scheme for unknown samples.

Journal Article↗
PubMedDate not supplied

Rendez-vous in the oviduct: implications for superovulation and embryo transfer.

The meeting between the maternal and paternal gametes is dependant upon a number of complicated processes. On the maternal side it involves maturation of the oocytes under the influence on both peripheral and follicular endocrine factors. Deviations in the normal pattern of maturation will lead to ovulation of inferior oocytes. On the paternal side the transport of spermatozoa in the female genital tract following mating is an area of great importance. The establishment of the sperm reservoir in the isthmus is dependant upon a number of factors (intracellular calcium concentrations, oligo-saccharides, change in estradiol: progesterone ratio in the afferent blood supply). Alterations of the normal micro-environment may disturb both binding, release and transport as a whole. The process of fertilization occurs in the ampullar region of the oviduct and it involves several well tuned steps: binding to the zona pellucida where the acrosome reaction takes place, penetration, fusion between the oolemma and the sperm plasma membrane, activation with the release of the cortical granules, decondensation of the sperm chromatin, pronucleus formation and finally syngamy where the two pronuclei fuses. The egg will experience the first cleavage shortly thereafter. Superovulation may disturb a number of these processes including oocyte maturation (arrest at MI) and sperm and zygote transport in the oviduct caused by the deviant endocrine environment, thus leading to a higher incidence of lack of fertilization and poor embryos quality.

Acrosome Reaction↗
PubMedDate not supplied

Collection of oviduct fluid in heifers.

The present experiments were undertaken in order to develop an alternative way of collecting oviduct fluid from heifers (n = 13). Under general anesthesia and through a midline incision, catheters were anchored in the ampullar region of the oviduct with ligatures of silk or steel and the uterotubal junction ligated. Subsequently, they were guided through the uterine wall into the lumen of one uterine horn and then transversed caudally through the cervix and vagina until they finally passed the vulva-vestibulum and could be attached to cryotubes taped to the tail. Fluid was collected daily over an average of 60 days for all animals (range 6-183). When only steel suture was used the average collection time was 99 days. The volume reached maximal values on the day of heat. In conclusion, the present experiment showed that it is possible to use alternative ways for bovine oviduct catheterization which permitted sampling without any noticable discomfort for the animals. The sampling period increased considerably when steel replaced nylon in the fixation of the catheters in the ampullar part of the oviduct.

Animals↗