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Biomedical subjects

F Tedeschi

Publications and source records attributed to F Tedeschi.

At least 19 recordsLinked to original sources

Creutzfeldt-Jakob disease with a novel extra-repeat insertional mutation in the PRNP gene.

The authors investigated two unrelated patients with Creutzfeldt-Jakob disease (CJD) with clinical features of sporadic CJD (sCJD) carrying one extra octapeptide repeat in the prion protein (PrP) gene (PRNP). A synaptic type PrP distribution throughout the cerebral gray matter and plaque-like PrP deposits in the subcortical gray structures were detected immunocytochemically. The different patterns of PrP deposition were associated with distinct types of protease-resistant PrP, similar to type 1 and type 2 of sCJD. The features suggest that this insertion is a pathogenic mutation.

14-3-3 Proteins↗

Modulation of host cell activation during feline immunodeficiency virus (FIV) infection.

The authors describe the mitogenic effect of feline immunodeficiency virus (FIV) infection (1) in vitro, on feline resting peripheral blood lymphocytes (PBL), and (2) in vivo, in experimentally infected cats. Infected PBL were more readily recruited than non-infected PBL, into the G1 phase of the cell cycle and showed increased expression of the specific cell-cycle markers p53 and p56. In-vivo lymphocyte activation following FIV infection was demonstrated by increased germinal centre activity in infected lymph nodes, together with a high expression of CD30, a B-cell activation marker. These results suggest that early events in FIV infection include modulation of host cell activation. Possible implications for pathogenesis are discussed.

Animals↗

[Ag-NORs, nucleus-nucleolus-associated antigens (Ki67, PCNA, P-105 and p-120): prognostic markers of meningioma recurrence].

The predictive significance of some nucleus-nucleolus associated markers, such as Ag-NOR, Ki67, PCNA, p-120, P-105, for the recurrency of meningiomas was investigated. A retrospective analysis was performed on a series of transitional meningiomas and of their recurrencies. Similar meningiomas but with no recidivism were used as controls. All cases were represented by women between the V and the VI decade of age. Besides, having all tumors presented with a cranial convexity localization total removal had been achieved. Recurrencies had taken place after 4.5 and 7.5 years in ten and two women, respectively. In all cases considered, the tumoral histotype did never present with structural elements in general suggestive of recurrence, such as high degree of cellularity, atypia, nuclear polymorphism, necrosis, appreciable mitotic index. On histological seriated 3 microns thick sections the silver staining technique of nucleolar organizer region-associated proteins (NORs) and the Ki67, PCNA, p-120, P-105 immunostaining ABC technique were applied. For each case 1000 tumoral cells were counted, with evaluation of the number of Ag-NOR dots and the percentage of Ki67, PCNA, p-120, P-105 positive cells. From the analysis, a mean value of Ag-NOR dots resulted of 6.44 +/- 0.65 in primitive meningiomas and of 6.53 +/- 0.88 in their respective recurrencies. In the control tumors the mean value of Ag-NOR dots resulted to be 3.53 +/- 0.55. Such difference between tumors that had repeated and controls that had not, was statistically significant (p < 0.001). For what concerns the expression of immunocytochemical relevant markers the percentage of positive cells, in primitive tumors (P), in recurrencies (R) and in the controls (C) was, namely, as follows: Ki67 (P: 14%, R: 12%, C: 6%); PCNA (P: 38%, R: 37%, C: 8%); and p-120 (P: 57%, R: 62%, C: 12%). The expression of P-105 was but occasional and without significance. From the data described, one can conclude that the evaluation of the whole of the markers considered in transitional meningiomas does predict recidivism.

Aged↗

Wernicke's encephalopathy: occurrence and pathological aspects in a series of 400 AIDS patients.

BACKGROUND: Wernicke encephalopathy (WE), acute (microhaemorrhages) and chronic (proliferation of capillaries) is actually considered as a not uncommon, and curable, condition in several diseases, and not only in alcoholic patients. Why serotoninergic nuclei, and whether blood brain barrier (BB) are involved were our questions. METHODS: In a dramatic series of AIDS cases we selected 380 brains, all belonging to drug addicted subjects. In all Thiamine administration had been under 20 mg pro die and by oral way. In the cases considered, opportunistic infections were present in the 40%, and/or HIV specificity in the 35%. RESULTS: "Acute" WE was found in nearly the 10%. All patients presented with CNS lesions, other than those of WE, but HIV specificity was found only in 5. They all showed changes in Choroid Plexus, namely alterations of various type of the cuboid epithelium, such as swelling, disruption, hyperplasia. DISCUSSION: WE is set in connection with pyruvate accumulation at capillary level, likely bound to the Thiamine deficiency and to the lack of energy thus induced. Apart from obvious haemorrhagic aspects, CFS studies in WE are lacking. Choroid structure is not merely a permeable membrane (CSF is not a filtrate). Our findings would suggest that Thiamine plays a role in the energy supply to BB. Moreover, the existence of free nerve endings through the ependyma for the release and uptake of monoamines, allows to consider the elective involvement of serotoninergic neurons as somehow connected to the choroid plexus changes described.

Acquired Immunodeficiency Syndrome↗

Somatostatin gene expression in pancreatic islet cells is directed by cell-specific DNA control elements and DNA-binding proteins.

Somatostatin is a peptide synthesized in the pancreatic islets, nervous system, gastrointestinal tract, and thyroid gland. Factors that control islet cell-specific expression of the somatostatin gene were analyzed by expression of fusion genes consisting of 5' rat somatostatin gene sequences linked to coding sequences of the receptor genes, bacterial chloramphenicol acetyltransferase, and human growth hormone. Fusion genes containing 900 and 250 base pairs (bp) of 5'-flanking DNA were preferentially expressed at 5-10-fold higher levels in somatostatin-producing islet cell lines, as compared with islet cell lines that produced insulin and glucagon, and in three non-islet cell lines. A deletional mutation consisting of only 65 bp of 5'-flanking sequence of the rat somatostatin gene expressed in all islet cell lines but not in non-islet lines, indicating the existence of a negative-acting islet cell-specific element located between nucleotides -250 and -65. The 65-bp sequence contains the octameric cAMP-responsive enhancer (CRE) TGACGTCA (nucleotides -48 to -41). Fine mapping of sequences responsible for islet-specific expression by substitution of synthetic oligonucleotide cassettes revealed full retention of expression by deletion to nucleotides -48 and complete loss of expression at nucleotides -42 of the CRE. Substitution of the 9 bp adjacent 3' to the CRE of the somatostatin gene (nucleotides -40 to -32) with the corresponding sequence located 3' to the CRE of the glucagon gene abolished expression. By gel mobility shift and DNaseI footprinting analyses, proteins in extracts of islet cells bound to the 24 bp including the CRE and downstream adjacent 9 bp (nucleotides -58 to -35). An additional upstream region of DNA was protected from DNase I digestion (nucleotides -110 to -80). Proteins from non-islet cells bound to the region from nucleotides -58 to -35, but patterns of DNase I protection differed from those using proteins from islet cells. These observations indicate that several DNA-binding proteins interact with cis-acting elements located between 35 and 58 bp upstream of the transcriptional start site of the rat somatostatin gene to determine islet cell-specific gene expression. CRE-binding protein(s) is ubiquitous among phenotypically different cells, and expression of the somatostatin gene in non-somatostatin-producing islet cells appears to be inhibited by a negative-acting element located upstream of the CRE.

8-Bromo Cyclic Adenosine Monophosphate↗

[Cerebral cortex and HIV lesion specificity. A neuropathological study of the brain of 100 drug addicts].

Brains of AIDS patients do often display characters of HIV specificity, in the presence or not of opportunistic lesions. Mesodermal nodules with giant cells, and a peculiar primary demyelination, the progressive diffuse leukoencephalopathy of Kleihues et al., which can be found only in brains with giant cells, have been pointed out as typical. In 100 intra venous drug user patients, younger than 32 years (mean age: 26) the HIV specificity described was observed on 49 occasions. All these patients presented with Seitelberger's glio-neuronal poliodystrophy (GP), quite similar to that encountered in several kinds of encephalopathies. Nevertheless, in 35 of the patients with HIV typical findings, there was in the cortex and some other grey matter regions, an amount of diffuse mesodermal elements uncommon in encephalopathies, and so relevant as to contradict the notion itself of this kind of cerebral lesion, where "inflammatory" events ought not to appear. This aspect of HIV encephalopathy was indicated by us as "GP plus". An optic microscopy examination of the cortex allowed us to establish how in GP plus the neuronal changes are more severe and apparently older than in the other patients considered. The fact that the astrocytes did not behave differently in the two aspects of encephalopathy lead us to conclude that GP plus sets in through processes distinct from those in encephalopathy tout-court, and to put forward that it is a further character of HIV specificity.

AIDS Dementia Complex↗

Progressive multifocal leukoencephalopathy (PML): clinical and pathological findings in two short-duration patients.

The clinical features and neuropathological findings of two patients suffering from progressive multifocal leukoencephalopathy (PML) are reported. These patients had cancer and died two months and one month after onset of their neurological symptoms, respectively. In both demyelination was discovered only as a result of autopsy due to different reasons: the CAT-scan findings were misinterpreted in the first patient, while in the second diagnosis was overshadowed by the sudden progress towards a fatal outcome preceded by myoclonus and other encephalitis-like manifestations. The major findings were the extreme paucity of the mesodermal elements on the one hand, and the modest spread of the affected areas on the other. It is pointed out that, whatever the size of the lesions, characters were the same and that their formation could hardly be traced in time. The intriguing similarities between PML and several types of demyelination obtained experimentally using certain virus strains are remarked.

Aged↗

Relationship between growth inhibition and mitochondrial function in petite-negative yeasts. I. Effects of antibiotics and dyes upon pathogenic and non-pathogenic Candida species.

Antibiotics and dyes which preclude growth of Saccharomyces cerevisiae in media containing oxidizable carbon sources arrested the growth of Candida albicans, Candida tropicalis and Candida utilis even in glucose medium. The growth in the presence of sub-inhibitory concentrations of the various antibiotics and dyes determined a reduction in the cell survival but with no accumulation of respiratory deficient mutants. Under these culture conditions, the total respiration declined leaving a residual antimycin A-resistant--hydroxamate-sensitive O2 uptake, and the amount of the respiratory cytochromes aa3 and b synthesized was reduced. SDS gel electrophoresis of soluble proteins prepared from the antibiotic-treated cells showed some bands in the MW range 92-100 K, which became faint after the cells were grown in the presence of some mitochondrial inhibitors. The ultrastructural analysis of these cells evidenced disappearance of the mitochondrial cristae and their replacement by unfolded membranes. The data obtained suggest that the petite negative trait of Candida could depend on the non-viability or on the very low viability of those cells which have lost their mitochondrial function.

Anti-Bacterial Agents↗

Relationship between growth inhibition and mitochondrial function in petite-negative yeasts. II. Effects of central nervous system drugs upon pathogenic and non-pathogenic Candida species.

Six nervous system drugs which inhibited vegetative reproduction of S. cerevisiae arrested also mitotic division of C. utilis, C. albicans and C. tropicalis. Chlorpromazine and chlorpheniramine which proved to be the most effective, affected respiration and cytochrome biosynthesis. Electrophoretic bands with MW congruent to 100 K were faint in silver-stained electrophoregrams of proteins from cells grown in the presence of a sub-inhibitory concentration of chlorpromazine.

Amitriptyline↗

Cerebral mycosis: clinico-pathological report of four cases observed in fifteen months.

Cerebral mycosis is a rare condition, difficult to diagnose in life, but is not easily missed at post-mortem examination. We report clinical and pathological findings in four patients with long duration prodromes, seizures and psychiatric symptoms. All of them had been misdiagnosed. Actinomycotic granules in two and Aspergillus filaments in the other patients were ascertained at histological examination. Two of the patients were in their twenties and apparently healthy. We suggest that the possibility of mycotic infection should be considered even in cases where no lowering of the body's defences can be postulated. Cell mediated immunity defects may be assumed as underlying these infections. Therefore we would suggest the importance of immunological tests for type IV immune responsiveness in all intracranial infective processes of undefined etiology.

Actinomycosis↗

Megalencephaly with formation of Rosenthal fibers in symmetric subependymal gliomatous proliferations: clinicopathologic report.

Clinical and neuropathologic observations are reported concerning a girl with retarded psychomotor development accompanied with a steady increase in the volume of the cranium and brain, tetraparesis, and a serious epileptic syndrome resulting in death at the age of 13 years. The neuropathologic study revealed a marked megalencephaly and the presence of two bilateral and symmetric areas of atypical glial proliferation, corresponding with the optostriatal groove, with endoventricular protrusion: in this region the histologic findings gave evidence of a tapetum of Rosenthal fibers. Discussion is focused on the observed neuropathologic aspects in relation to the various diagnostic hypotheses: Alexander's disease, primary megalencephaly associated with astrocytomas or reactive gliosis, or megalencephaly associated with subependymal hamartomas.

Brain↗

On the pathology of meningiomas. A study of 412 cases.

Some pathological features of tumors arising primarily in the meninges are discussed on the basis of 412 surgically treated meningiomas during the period running from 1964 to 1978. Cases of meningeal sarcomas were not considered. Except for a few cases, pathology and clinical course have been generally in agreement. The incidence of histological types like meningotheliomatous, fibroblastic, angioblastic or atypical meningiomas has been verified in relation to sex, age and intracranial or spinal conventional locations. The problem of recurrencies has been studied either comparing the histological features with the first observation or comparing histopathological types with location and details of surgical procedure. Additional criteria like uni or multifocal origin of the tumors and histological features of the peri-lesional tissues, often harbouring small meningiomatous nests, have been taken into account.

Brain Neoplasms↗

Meningiomas. A light and electron microscopy study.

A morphological and ultrastructural study was undertaken from a personal series of meningiomas. Especially the fine structure of the tumour has been described by the electron microscopic study of 16 meningotheliomatous and 4 fibroblastic meningiomas. In all cases, it was possible to distinguish certain cells with epithelial features such as desmosomes, microfilaments and interdigitating extensions. Also the cytological patterns of fibroblastic meningiomas usually were similar to the meningotheliomatous type, anyhow the intercellular space between the interdigitating extensions of adjacent cells was occupied by collagen-fibers. At present, it has been impossible to demonstrate the capability of the tumour cells to synthetize collagen. Since the tumour cells of both the meningiomas are substantially similar to the subarachnoid space meningocyte, it is concluded that the neoplasm rises from a cell with double potentiality for fibroblastic and epithelial differentiation.

Female↗