Biomedical subjects

E Torre

Publications and source records attributed to E Torre.

At least 19 recordsLinked to original sources

PubMed1996

Differential expression and phosphorylation of the 74-kDa intermediate chains of cytoplasmic dynein in cultured neurons and glia.

The 74-kDa intermediate chains (IC74) of the cytoplasmic dynein complex are believed to be involved in the association of dynein with membranous organelles. While each dynein molecule is thought to have two or three IC74 subunits, at least six different IC74 protein isoforms were found in dynein from brain. Therefore we investigated the relationships of the brain cytoplasmic dynein IC74 isoforms and their association in the dynein complex at the cellular level. We found that cultured cortical neurons and glia express distinct IC74 isoforms. The IC74 isoform pattern observed in dynein from cortical neurons was generally similar to that found in dynein from adult brain, indicating that there are different populations of cytoplasmic dynein in neurons. Two IC74 isoforms were observed on two-dimensional gels of dynein from glia, while a single glial IC74 mRNA was detected. Metabolic labeling of glial dynein with 32P followed by treatment of the isolated dynein with phosphatase in vitro demonstrated that one of the glial IC74 isoforms is the product of the single glial IC74 mRNA and that the other is its phosphoisoform. A single mRNA product and its phosphoisoform are therefore sufficient for constitutive dynein function and regulation in glial cells.

Alternative Splicing↗

PubMed1994

Dynamin 1 antisense oligonucleotide treatment prevents neurite formation in cultured hippocampal neurons.

Dynamin 1 (D100) is a microtubule-activated GTPase that is believed to play a role in the early steps of receptor-mediated endocytosis. Previous studies on the characterization of the Drosophila dynamin gene homolog, known as shibire, suggest that this protein may also participate in the formation of neuronal processes. To understand the role of rat brain dynamin 1 in neuronal morphogenesis, we correlated the intracellular levels of dynamin with the formation of neurites in rat hippocampal neurons and neuroblastoma N1E-115 cells in vitro. Quantitative Western and Northern blot analyses show that dynamin levels increase during neurite formation in both the hippocampal neurons and N1E-115 cells and decrease in N1E-115 cells during serum-induced neurite retraction. Furthermore, using antisense technology, we investigated the effect of decreased intracellular levels of dynamin on neurite formation in cultured embryonic hippocampal neurons. Antisense oligonucleotides against sequences surrounding the initiation codon of the rat brain dynamin gene (D100) reduce the intracellular levels of dynamin by approximately 90% and impair the formation of the minor and axon-like processes in a dose-dependent manner. Taken together, these results suggest that dynamin-mediated processes are necessary for normal neuronal morphogenesis.

Amino Acid Sequence↗

PubMed1994

Insertion sequence IS200 fingerprinting of Salmonella typhi: an assessment of epidemiological applicability.

When Pst I-generated digests of genomic DNA from each of the type strains of 49 of the Vi phage types of Salmonella typhi were probed with a PCR-amplified IS200 gene probe, all strains were found to possess at least 11 IS200 elements carried on fragments in the range 24.2-1.2 kb. Fourteen fingerprints were identified but two patterns designated IS200Sty1 and IS200Sty2 predominated. In one strain, a plasmid-mediated IS200 element was identified. When IS200 fingerprinting was applied to epidemiologically-unrelated strains of S. typhi isolated in Ecuador, 3 patterns were identified in 10 strains belonging to 9 different phage types. It is concluded that Vi phage typing remains the method of choice for the primary differentiation of S. typhi but that IS200 fingerprinting may be of limited use in laboratories which do not have access to phage typing.

Bacteriophage Typing↗

PubMed1993

Insertion sequence IS200 can differentiate drug-resistant and drug-sensitive Salmonella typhi of Vi-phage types E1 and M1.

The type strains of Vi-phage types E1, M1 and A of Salmonella typhi, together with drug-resistant and drug-sensitive strains of phage types E1 and M1 isolated in 1992 from patients associated with India or Pakistan, and a drug-resistant strain of phage type A isolated in South Africa in 1991, were characterised with respect to the presence of plasmids conferring resistance to antimicrobial drugs and their chromosomal insertion sequence IS200 profiles. The three type strains, the drug-sensitive strains of Vi-phage types E1 and M1, and a strain of phage type M1 resistant to ampicillin and trimethoprim but not to chloramphenicol, did not contain plasmids. In contrast, for strains of phage types E1 and M1 resistant to chloramphenicol, ampicillin and trimethoprim, and for the drug-resistant strain of phage type A, the complete spectrum of resistance was encoded by high molecular mass plasmids belonging to the H1 incompatibility group. Characterisation of IS200 profiles demonstrated that at least 13 IS200 copies were distributed on the chromosome of all strains tested. Although the IS200 profiles of the type strains of Vi-phage types A, E1 and M1 were identical, it was possible to distinguish between drug-sensitive and drug-resistant strains of Vi-phage types E1 and M1 isolated from patients infected in India and Pakistan by this method. It was concluded that although IS200 typing is not as discriminatory as phage typing for the primary subdivision of S. typhi, it may be useful for certain epidemiological investigations and, in particular, for investigating the origins of strains with multiple drug resistance.

Bacteriophage Typing↗

PubMed1993

Characterization of Salmonella virchow phage types by plasmid profile and IS200 distribution.

The type strains of the 57 phage types of Salmonella virchow have been characterized by plasmid profile and by distribution of the insertion sequence IS200. Thirty-two strains carried plasmids and 21 profile types were identified; 17 strains were resistant to antimicrobial agents. In contrast only six of the type strains carried IS200 elements and three patterns were identified. Within Salm. virchow phage type 31, five of 10 wild-type isolates carried plasmids and two plasmid profiles were identified; in contrast, an IS200 element was identified in the genome of only one of these strains. It is concluded that for Salm. virchow, IS200 is unlikely to significantly extend the degree of discrimination achieved by phage typing which may be supplemented when appropriate by plasmid profile typing.

Animals↗

PubMed1993

Factors influencing fecal shedding of Campylobacter jejuni in dogs without diarrhea.

Rectal swab specimens were collected from 362 apparently healthy dogs of different origin, age, breed, and sex. Specimens were obtained in summer, autumn, and winter. Ninety-five thermophilic Campylobacter spp were isolated: C jejuni biotype I, n = 57, C jejuni biotype II, n = 1, C coli, n = 36, and C laridis, n = 1. Biotypes of C jejuni recovered were the same as those associated with Campylobacter-induced enteritis in human beings. Prevalence of C jejuni was significantly (P < 0.05) greater: in dogs < 6 months old than in adult dogs; in dogs living under high density and cohabitation housing conditions for long periods; and in autumn.

Age Factors↗

PubMed1990

[Therapeutic use of glutathione].

Liver pathology is very frequent in western countries. The numerous therapeutic approaches suggested so far for the prevention or limitation of liver damage in the course of hepatic diseases have often had disappointing results. Considering that at least part of the liver injury is caused by free radicals, the authors have tried an antioxidant, glutathione, as a hepatoprotective agent. Although particularly brilliant results were not achieved, clinical conditions and laboratory findings were improved in hall patients treated with glutathione.

Adult↗

PubMed1990

A study of the relationship between life events and disturbed self image in adolescents.

The occurrence and subjective importance of a list of life events were determined in 1296 adolescents and compared with the risk of a disturbed self image, as assessed on the basis of Offer's (1981) questionnaire. A disturbed self image was shown by 24.2 per cent of the sample, and it was significantly associated with a reported excess of events (one standard deviation above the mean), and with the reporting of specific classes of events. These included serious disagreement between parents, sudden decrease in family income, serious abuse either within the family or outside the family, and having had an abortion. The events were sorted and ranked by the observed values of their sample frequency, subjective importance, and assessed risk of a disturbed self image. The rarest and subjectively most important events were often associated with a higher risk of a disturbed self image, and the role of reporting such "exceptional" experiences is discussed.

Adolescent↗

PubMed1990

Effects of chronic ethanol treatment on alpha-MSH concentrations in rat brain and pituitary.

Male Sprague-Dawley rats were chronically treated with a liquid diet containing 6.5% (v/v) ethanol or equicaloric sucrose. Rats were killed after 21 days of treatment. alpha-MSH-like immunoreactivity was measured in the intermediate lobe of the pituitary gland and in several brain regions. Chronic ethanol treatment significantly reduced alpha-MSH-like immunoreactivity in the pituitary gland; in the arcuate nucleus of the hypothalamus and in the substantia nigra. The results of this study confirm the earlier findings that chronic ethanol treatment reduces POMC biosynthesis in the pituitary gland and in the central nervous system.

Alcoholism↗

PubMed1990

[Cerebral metabolism and permeability of the hemato-encephalic barrier in an experimental model for brain radiotherapy].

Whole brain irradiation (WBR) can produce acute and chronic neurological adverse effects, which are usually divided into acute, early delayed and late delayed reactions according to the time of onset. To assess the impact of WBR on brain functional parameters during the early-delayed phase, we employed the [14C]-2-deoxyglucose (2-DG) and the [14C]-alfa-aminoisobutyric (AIB) acid quantitative autoradiographic techniques to study local cerebral glucose utilization and blood-brain barrier permeability, respectively. Sprague-Dowley albino rats were exposed to conventional fractionation (200 Gy/day 5 days a week) for a total dose of 4000 Gy. Experiments were made 3 weeks after completion of the radiation exposure. In comparison with control and sham-irradiated animals, cerebral metabolic activity was diffusely decreased following irradiation. As a rule, brain areas with the highest basal metabolic rates showed the highest percentage drop in glucose utilization. Changes in blood-brain barrier function, as assessed by an increased transcapillary transport of AIB, were also demonstrated in specific brain regions. This study illustrates how moderate doses of WBR induce well-defined changes in brain metabolism and BBB function, which are possibly involved in the pathogenesis of the early-delayed radiation-induced cerebral dysfunction in humans.

Aminoisobutyric Acids↗

PubMed1989

Psychological aspects of weekend headache sufferers in comparison with migraine patients.

Sometimes the relaxation after stress may trigger a migraine attack. This is the principle that underlies that particular variant of migraine called "weekend headache". We hypothesize the presence in weekend headache prone subjects of a particular psychological background, different from that of common migraine sufferers. In order to detect possible differences supporting our hypothesis, we studied 104 new outpatients: 46 patients suffering from headache only on weekends (23 males and 23 females) and 58 matched common migraineurs (26 males and 32 females) with no weekend predilection. The psychological assessment was performed using the following psychometric tools: MMPI, BDI, STAIX1-X2. A clinical assessment of each patient was also carried out. Significant differences were found after statistically analyzing the test results. Most of the MMPI scales were found to be more elevated in both male and female weekend headache sufferers. From a clinical point of view, the weekend headache attacks proved to be similar to those of common migraine, but with a significantly higher incidence of concomitant symptoms. Our study confirms the important role that psychological factors play in the pathogenesis and clinical development of migraine and leads us to conclude that a psychic tension component is associated with the vascular one in weekend headache.

Adult↗

PubMed1989

alpha-Melanotropin induced excessive grooming involves brain acetylcholine possible interaction in the ventral tegmental area.

Alpha-melanotropin (alpha-MSH) injected into the ventral tegmental area (VTA) or intraventricularly (icv) elicits excessive grooming. The icv infusion of the peptide also induces the stretching-yawning syndrome (SYS). The present study demonstrates that intra-peritoneal, icv or VTA administration of atropine, suppresses alpha-MSH-induced behavior elicited by i cv or VTA injections of the peptide. Experimental evidence is presented suggesting that alpha-MSH may act specifically on a cholinergic afferent to the VTA. The results appear to indicate that a neural target distinct from the dopamine system may be formerly activated by the peptide to elicit behavioral changes such as excessive grooming.

Animals↗

PubMed1988

Cholinergic mediation in the ventral tegmental area of alpha-melanotropin induced excessive grooming: changes of the dopamine activity in the nucleus accumbens and caudate putamen.

The effect of alpha-melanotropin (alpha-MSH) on the rat mesolimbic dopaminergic activity was estimated by measuring the changes in dihydroxyphenyl acetic acid (DOPAC) and dopamine (DA) endogenous levels in the nucleus accumbens (Ac) and caudate putamen (CP). A marked increase of DOPAC/DA ratios resulting from an increase in DOPAC and decrease in DA levels was found in the Ac 30 and 65 min after bilateral alpha-MSH-injections (1 microgram) into the ventral tegmental area (VTA). Similar changes were observed in the CP 65 min post-injections. These peptide-induced changes were completely inhibited by a previous VTA injection of atropine (1 microgram), at a dose that totally blocked the alpha-MSH-induced excessive grooming and motor activation. These results confirms that alpha-MSH affects a cholinergic afferent to the VTA which modifies the mesolimbic dopaminergic system involved in the alpha-MSH/ACTH-induced behaviors.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1988