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Biomedical subjects

A Schenone

Publications and source records attributed to A Schenone.

85 records · Page 5Linked to original sources
PubMed1974

Specific inhibition of the enzymic decarboxylation of S-adenosylmethionine by methylglyoxal bis(guanylhydrazone) and related substances.

Methylglyoxal bis(guanylhydrazone) {1,1'-[(methylethanediylidene)-dinitrilo]diguanidine} is a very potent inhibitor of putrescine-activated S-adenosylmethionine decarboxylases from many different mammalian tissues, including sublines of mouse L1210 leukaemia that are resistant to the drug as well as sublines that are sensitive. The inhibition of purified rat ventral prostate S-adenosylmethionine decarboxylase is competitive with respect to the S-adenosylmethionine substrate, and is much greater in the presence than in the absence of the activator putrescine. Inhibition by the drug depends, among other things, on the nature of the aliphatic amines that can serve as stimulators of rat prostate S-adenosylmethionine decarboxylase. Effects of some congeners of methylglyoxal bis(guanylhydrazone) on the enzyme are described.

Amidines↗
PubMedDate not supplied

Segmentation of multivariate medical images via unsupervised clustering with "adaptive resolution".

The need for quantitative information is becoming increasingly important in the clinical field. In this paper we present an interactive X11 based system, devoted to segmentation of multivariate medical images, including an unsupervised neural network approach to clustering. The following steps are considered in the analysis sequence: feature extraction, reduction of dimensionality, unsupervised data clustering, voxel classification, interactive post-processing refinement. The environment turns out to be extremely interactive, thus making the user able to display and modify data during processing, to set parameters, to choose different methods and different tools for each step, and to define online the whole analysis sequence.

Algorithms↗
PubMedDate not supplied

Exclusion of the SCN2B gene as candidate for CMT4B.

Charcot-Marie-Tooth disease type 4B (CMT4B) is a demyelinating autosomal recessive motor and sensory neuropathy characterised by focally folded myelin sheaths in the peripheral nerve. The CMT4B gene has been localised by homozygosity mapping and haplotype sharing in the 11q23 region. A cDNA encoding for the beta 2 subunit of the human brain sodium channel, SCN2B, has been recently assigned to the same chromosomal interval by FISH. The SCN2B gene has been considered a good candidate for CMT4B on the basis of protein homology, chromosomal localisation, and putative biological function of the coded product. In this paper, we report the genomic structure of the SCN2B gene consisting of 4 exons and 3 introns spanning a region of approximately 12 Kb. In addition, a search for mutations in patients affected with CMT4B as well as a refined physical localisation excludes SCN2B as the CMT4B gene.

Base Sequence↗
PubMedDate not supplied

"Pure" meningeal carcinomatosis as the autopsy-proven sole manifestation of an undetected cancer.

Meningeal carcinomatosis (MC) was diagnosed in a 37-year-old woman, based on the finding of neoplastic cells in the cerebrospinal fluid. The patient had no relevant antecedent except the resection of a breast "nodule" at the age of 20. No primary cancer nor other metastases were detected, even at autopsy. Histopathology, immunocytochemistry and electron microscopy confirmed pure leptomeningeal infiltration by poorly differentiated adenoepithelial cancer. This case includes several unusual features and raises the possibility of an extremely long-lasting interval between an unrecognized primary (breast?) carcinoma and MC.

Adult↗
PubMedDate not supplied

Amyloid neuropathy in light chain multiple myeloma.

We describe a 73-year-old man with peripheral neuropathy and light chain lambda-type myeloma. A sural nerve biopsy showed the typical neuropathological picture of amyloid neuropathy. With the present case we first demonstrate amyloid deposits in peripheral nerves during light chain multiple myeloma and stress the importance of amyloidosis in the development of peripheral neuropathy.

Aged↗