[Attempt to correlate between environmental styrene at low concentrations and its urinary mandelic acid metabolite].
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Air Pollutants↗
Biomedical subjects
E Borrelli
Publications and source records attributed to E Borrelli.
Quasi-total-body exposure to an oxygen-ozone mixture in a sauna cabin.
We have investigated the effects of quasi-total-body exposure of healthy volunteers to either an oxygen-ozone mixture (O(2)-O(3)) or to oxygen (O(2)) alone during a short period in a sauna cabin. The subjects underwent both an experimental and a control examination, separated by a 3.5-month interval. Body mass, blood pressure, body temperature changes, electrocardiograms, venous blood gas and haemocytometric analyses, total antioxidant status and plasma levels of protein thiol groups, thiobarbituric acid reactive substances (TBARS), plasma cytokine, hepatic enzymes and creatine were determined before, immediately after the 20-min period in the cabin and then 0.5, 1.0 and 24 h afterwards. We observed statistically significant variations of body temperature, venous partial pressure of O(2) values, TBARS and plasma levels of interleukin 8, particularly after O(2)-O(3) exposure. The increase in TBARS plasma levels concomitant with protein oxidation has been tentatively interpreted as being attributable to the transcutaneous passage of some reactive O(2) species, which should be considered if this approach is to be used as a biological response modifier. However, in the present study no adverse effects were noted after one session.
Adult↗
Haloperidol treatment reverses behavioural and anatomical changes in cocaine-dependent mice.
Abnormal dopamine (DA) transmission occurs in many pathological conditions, including drug addiction. Previously, we showed DA D2 receptor (D2R) activation results in pruning of the axonal arbour of DA neurones that innervate the dorsal striatum. Thus, we hypothesised that long-term D2R stimulation through drugs of addiction should cause arbour pruning of neurones that innervate the ventral striatum and thus reduce DA release and contribute to craving. If so, D2R blockade should return these arbours to normal size and may overcome craving. We show that long-term treatment with a D2R antagonist (haloperidol) reverses behavioural and anatomical effects of cocaine dependence in mice, including relapse. This change in arbour size reflects new synapse formation and our data suggest this must occur in the presence of increased DA activity to reverse cocaine-seeking behaviour. These findings hold significant implications for the understanding and treatment of cocaine addiction.
Animals↗
Adenovirus-2 E1A products repress enhancer-induced stimulation of transcription.
The adenovirus-2 early region 1A (E1A) products repress activation of transcription induced by the simian virus 40, polyoma virus and adenovirus-2 E1A enhancers. The repression probably involves an interaction between the enhancer elements and a trans-acting factor(s), possibly the E1A products themselves.
Adenoviruses, Human↗
A mutated polyoma virus enhancer which is active in undifferentiated embryonal carcinoma cells is not repressed by adenovirus-2 E1A products.
Enhancers stimulate transcription of several eukaryotic genes (for review see ref. 1). While some enhancers, like that of simian virus 40 (SV40), are active in a wide range of cell types, others are more cell-specific. For example, the polyoma virus (Py) enhancer is not active in undifferentiated embryonal carcinoma (EC) cells, such as F9 cells, while it is active in differentiated cells. In contrast, the SV40 enhancer is active in both undifferentiated and differentiated EC cells. One possible explanation for this difference is that the two viral enhancers interact with different positively or negatively acting transcription factors, a notion supported by in vitro experiments showing that the Py enhancer interacts with proteins that do not bind to the SV40 enhancer. Some viral and cellular enhancers, including the Py and SV40 enhancers, can be negatively regulated by the products of the E1A transcription unit of adenovirus-2. As it has been postulated that undifferentiated F9 cells contain an E1A-like activity, it is possible that the latter is responsible for the lack of activity of the Py enhancer in these cells. We show here that the E1A products do not repress a point mutant of the Py enhancer (Py ECF9.1; ref. 11 and references therein) that is active in undifferentiated F9 cells. This result is consistent with the idea that undifferentiated F9 cells contain a cellular repressor that blocks the Py enhancer and that this repressor has the same target sequence as the E1A proteins.
Adenovirus Early Proteins↗
Interferon levels in human pulmonary tumors are lower than plasma levels.
It is uncertain whether interferon levels in the interstitial fluid of tumors are equivalent to interferon plasma levels and we have investigated this problem in human pulmonary tumors by infusing human recombinant interferon alpha A and natural interferon Beta for about three hours before surgery. By determining the hematocrit and hemoglobin content it was possible to calculate interferon values (International Units/g wet tissue) present in the interstitial fluid of tumor and lung samples, simultaneously. In 14 patients (epidermoids, n = 9 and adenocarcinomas, n = 5) interferon levels in tumor and "normal" lung expressed as percentages of interferon plasma levels were: 9.5 +/- 3.9 and 29.8 +/- 6.9 for recombinant interferon alpha A and 3.1 +/- 0.4 and 10.1 +/- 2.4 for natural interferon Beta, respectively. Differences for both interferons are statistically significant (p less than 0.05). To our knowledge these are the first data indicating that interferon levels in pulmonary tumor interstitial fluid are markedly lower than those in normal lung although they do not clarify the main factor responsible for the decrease, they explain at least in part the negligible therapeutic activity of interferons in these tumors and emphasize the need for new approaches for improving the therapeutic index of interferons.
Adult↗