Transplantation of human cortex with Alzheimer's disease into rat occipital cortex; a model for the study of Alzheimer disease

Senile dementia of the Alzheimer type (SDAT) is a major problem in the human senescent population. As this pathology cannot be reproduced in animals, research into its development is greatly impeded. The technique of implantation of the nervous tissue has been utilized in order to establish an animal model and to test the possible existence of a transmissible agent. When human temporal cortex with Alzheimer's disease is implanted in the occipital cortex of 7-week-old rats, human cerebral tissue containing abundant tangles induces in the receiver cortex a reactive fibrous gliosis. In the processes of the astrocytes, twisted filaments are evident among bundles of normal filaments. These alterations could be induced by the metabolising of abnormal filament subunits or by some infectious agent introduced by the implant.     

Experimental model for induction of lymph node metastases with a human heterotransplanted melanoma in rat

Résumé Le travail décrit une technique expérimentale qui permet d'obtenir de grosses métastases ganglionnaires chez le rat après inoculation intratesticulaire de la tumeur IOB hR 18. Ce modèle expérimental peut Être utilisé dans diverses études concernant la pathogénie et la thérapie des métastases.     

Spread of cobalt from a cortical epileptic lesion induced by a cobalt-gelatine implant into the frontal cortex of the rat

Summary The spread of cobalt ions from cobalt induced epileptic foci in rats has been investigated. Atomic absorption spectrophotometry and heavy-metal histochemistry reveal cobalt ions spread very widely from the focus. Biochemical and physiological consequences for this model of epilepsy are discussed.     

Investigations into the effects of ACTH on the half-life of mitochondrial proteins in the rat adrenal cortex

Summary ACTH elongates the half-life of the mitochondrial proteins from the rat adrenal cortex, and chloramphenicol inhibits this effect of ACTH. The hypothesis is advanced that the ACTH-provoked stabilization of the adrenocortical mitochondrial proteins requires continuous mitochondrial DNA-dependent protein synthesis.     

Investigations into the effects of ACTH on the half-life of mitochondrial proteins in the rat adrenal cortex.

ACTH elongates the half-life of the mitochondrial proteins from the rat adrenal cortex, and chloramphenicol inhibits this effect of ACTH. The hypothesis is advanced that the ACTH-provoked stabilization of the adrenocortical mitochondrial proteins requires continuous mitochondrial DNA-dependent protein synthesis.     

The human leukemia cell line, THP-1: a multifacetted model for the study of monocyte-macrophage differentiation

THP-1 is a human monocytic leukemia cell line. After treatment with phorbol esters, THP-1 cells differentiate into macrophage-like cells which mimic native monocyte-derived macrophages in several respects. Compared to other human myeloid cell lines, such as HL-60, U937, KG-1, or HEL cell lines, differentiated THP-1 cells behave more like native monocyte-derived macrophages. Because of these characteristics, the THP-1 cell line provides a valuable model for studying the mechanisms involved in macrophage differentiation, and for exploring the regulation of macrophage-specific genes as they relate to physiological functions displayed by these cells.     

Effect of ACTH on the zona reticularis of the rat adrenal cortex: An ultrastructural stereologic study

Summary The effects of ACTH on the rat adrenalzona reticularis were investigated by stereologic methods. It was found that thezona reticularis cell responsiveness to ACTH is similar to that of thezona fasciculata elements. This excludes that thezona reticularis of the adult rat can only function as the site of destruction of worn-out elements migrating from the adrenal outer zones.Acknowledgment. We wish to thank Mr.G. Gottardo for his skilled technical assistance. This work was partly supported by a contract with the CNR No. C.T.73.00663.04.     

Effect of ACTH on the zona reticularis of the rat adrenal cortex: an ultrastructural stereologic study.

The effects of ACTH on the rat adrenal zona reticularis were investigated by stereologic methods. It was found that the zona reticularis cell responsiveness to ACTH is similar to that of the zona fasciculata elements. This excludes that the zona reticularis of the adult rat can only function as the site of destruction of worn-out elements migrating from the adrenal outer zones.     

Familial hemophagocytic lymphohistiocytosis: a model for understanding the human machinery of cellular cytotoxicity

Cytotoxic T lymphocytes, natural killer cells, and NKT cells are effector cells able to kill infected cells. In some inherited human disorders, a defect in selected proteins involved in the cellular cytotoxicity mechanism results in specific clinical syndromes, grouped under the name of familial hemophagocytic lymphohistiocytosis. Recent advances in genetic studies of these patients has allowed the identification of different genetic subsets. Additional genetic immune deficiencies may also induce a similar clinical picture. International cooperation and prospective trials resulted in refining the diagnostic and therapeutic approach to these rare diseases with improved outcome but also with improved knowledge of the mechanisms underlying granule-mediated cellular cytotoxicity in humans.     

Analysis of the US business cycle with a Vector‐Markov‐switching model

This paper identifies turning points for the US ‘business cycle’ using information from different time series. The model, a multivariate Markov‐switching model, assumes that each series is characterized by a mixture of two normal distributions (a high and low mean) with the switching from one to the other determined by a common Markov process. The procedure is applied to the series composing the composite coincident indicator in the USA to obtain business cycle turning points. The business cycle chronology is closer to the NBER reference cycle than the turning points obtained from the individual series using a univariate model. The model is also used to forecast the series with some encouraging results. Copyright © 2001 John Wiley & Sons, Ltd.