Genome-wide analysis of p53-regulated transcription in Myc-driven lymphomas.

The tumour suppressor p53 is a transcription factor that controls cellular stress responses. Here, we dissected the transcriptional programmes triggered upon restoration of p53 in Myc-driven lymphomas, based on the integrated analysis of p53 genomic occupancy and gene regulation. p53 binding sites were identified at promoters and enhancers, both characterized by the pre-existence of active chromatin marks. Only a small fraction of these sites showed the 20 base-pair p53 consensus motif, suggesting that p53 recruitment to genomic DNA was primarily mediated through protein-protein interactions in a chromatin context. p53 also targeted distal sites devoid of activation marks, at which binding was prevalently driven by sequence recognition. In all instances, the relevant motif was the canonical unsplit consensus element, with no clear evidence for p53 recruitment by split motifs. At promoters, p53 binding to the consensus motif was associated with gene induction, but not repression, indicating that the latter was most likely indirect. Altogether, our data highlight key features of genome recognition by p53 and provide unprecedented insight into the pathways associated with p53 reactivation and tumour regression, paving the way for their therapeutic application.

[Locating the site of resistance to the endotracheal tube in fiberoptic oral intubation and maneuvers to overcome it: a mannequin simulation study]. / Intubación fibroóptica oral. Localización del lugar de resistencia al avance del tubo traqueal y maniobras para solucionarlo. Estudio de simulación en maniquí.

OBJECTIVE: To determine the most common tracheal points of resistance during orotracheal insertion of a fiberoptic tube in a mannequin by applying a maneuver algorithm to overcome the resistance. METHOD: Four study groups were established to compare 2 types of endotracheal tube: a standard tube and a reinforced flexible tube with an internal diameter of 7.5 mm. The tubes were used on their own or in combination with a Williams airway intubator. Two fiberoptic bronchoscopes were used, one to perform the test intubation and the other to observe the location of resistance and the effectiveness of the maneuvers for overcoming it. The degree of resistance was scored using a modified Jones scale, from 0 (intubation without resistance) to 4 (intubation impossible); location of resistance and time required for each intubation were also recorded. RESULTS: A total of 250 oral intubations were performed. Resistance was encountered in 75.2% of the cases. The main locations of obstruction were the right arytenoid cartilage and the posterior commissure. In 89.6% of the cases, intubation of the trachea was achieved without maneuvering or with a 90 degrees counterclockwise rotation. Statistically significant differences were found in resistance and intubation time when the reinforced flexible tube was used with the Williams intubator. CONCLUSIONS: Rotating the tube 90 degrees counterclockwise was an effective maneuver for overcoming resistance. The combination of a reinforced flexible tube and a Williams intubator was associated with less resistance and shorter intubation times.

Hematological changes in rats chronically exposed to oral aluminum.

This study was aimed to investigate the effects of the long-term oral exposure to aluminum sulfate on hematological parameters in rats. For this purpose, 24 adult female Wistar rats were divided in three groups with 8 animals each (control, citrate, and citrate plus aluminum groups). Rats from control and citrate groups had free access to tap water and to a sodium citrate solution (35 mM), respectively. Rats from citrate plus aluminum group received, as unique source of liquid, an aluminum sulfate solution (30 mM) diluted in the above-mentioned sodium citrate solution, ad libitum. After the treatment period (18 months), aluminum-exposed rats showed a significant decrease in the number of red blood cells, blood hemoglobin concentration and hematocrit when compared to rats from the control group. Serum iron levels were also significantly lower in citrate plus aluminum group, whereas total iron binding capacity did not change after citrate plus aluminum exposure. Erythrocyte thiobarbituric acid-reactive substances (TBARS) and nonprotein thiols (NPSH) levels, erythrocyte osmotic fragility and hepatic delta-aminolevulinic acid dehydratase (delta-ALA-D) activity did not change after treatment with citrate plus aluminum. Conversely, aluminum exposure increased delta-ALA-D activity in bone marrow. The present results indicate that long-term oral exposure to low doses of aluminum sulfate promotes alterations on erythrocyte parameters in rats, probably as a consequence of alterations in the iron status. In addition, although the details of the underlying mechanism remain unclear, our study reports, for the first time, a stimulatory effect of chronic aluminum exposure on bone marrow delta-ALA-D activity.

Effects of methylmalonic and propionic acids on glutamate uptake by synaptosomes and synaptic vesicles and on glutamate release by synaptosomes from cerebral cortex of rats.

Neurological dysfunction is common in patients with methylmalonic and propionic acidemias. However, the mechanisms underlying the neuropathology of these disorders are far from understood. In the present study we investigated the in vitro effects of methylmalonic (MMA) and propionic (PA) acids at various concentrations (1 microM-5 mM) on three parameters of the glutamatergic system, namely the basal and potassium-induced release of L-[3H]glutamate by synaptosomes, Na+-dependent L-[3H]glutamate uptake by synaptosomes and Na+-independent L-[3H]glutamate uptake by synaptic vesicles from cerebral cortex of male adult Wistar rats. The results showed that MMA significantly increased potassium-induced but not basal L-[3H]glutamate release from synaptosomes with no alteration in synaptosomal L-[3H]glutamate uptake. A significant reduction of L-[3H]glutamate incorporation into vesicles caused by MMA was also detected. In contrast, PA had no effect on these parameters. These findings indicate that MMA alters the glutamatergic system. Although additional studies are necessary to evaluate the importance of these observations for the neuropathology of methylmalonic acidemia, it is possible that the effects elicited by MMA may lead to excessive glutamate concentrations at the synaptic cleft, a fact that may explain previous in vivo and in vitro findings associating MMA with excitotoxicity.

Glycine, serine, and leucine metabolism in different regions of rat central nervous system.

We have investigated the glycine, serine and leucine metabolism in slices of various rat brain regions of 14-day-old or adult rats, using [1-14C]glycine, [2-14C]glycine, L-[3-14C]serine and L-[U-14C]leucine. We showed that the [1-14C]glycine oxidation to CO2 in all regions studied occurs almost exclusively through its cleavage system (GCS) in brains of both 14-day-old and adults rats. In 14-day-old rats, the highest oxidation of [1-14C]glycine was in cerebellum and the lowest in medulla oblongata. In these animals, the L-[U-14C]leucine oxidation was lower than the [1-14C]glycine oxidation, except in medulla oblongata where both oxidations were the same. Serine was the amino acid that showed lowest oxidation to CO2 in all structure studied. In adult rats brains, the highest oxidation of [1-14C]glycine was in cerebral cortex and the lowest in medulla oblongata. We have not seen difference in the lipid synthesis from both glycine labeled, neither in 14-day-old rats nor in adult ones, indicating that the lipids formed from glycine were not neutral. Lipid synthesis from serine was significantly high than lipid synthesis and from all other amino acids studied in all studied structures. Protein synthesis from L-[U-14C]leucine was significantly higher than that from glycine in all regions and ages studied.

Study of developmental changes on hexoses metabolism in rat cerebral cortex.

We have studied the developmental changes of glucose, mannose, fructose and galactose metabolism in rat cerebral cortex. As the animals aged, glucose, mannose and fructose oxidation to CO2 increased, whereas galactose oxidation decreased. Lipid synthesis from glucose and fructose also increased with age, that from mannose decreased and galactose did not change. Cytochalasin B, a potent non-competitive inhibitor of sodium-independent glucose transport, significantly impaired glucose, mannose and galactose metabolism, but had no effect on fructose metabolism. Both galactose or fructose did not change, whereas mannose declined the glucose metabolism. Glucose decreased fructose, galactose and mannose metabolism. Our results show that besides glucose, the metabolism of mannose, galactose and fructose present developmental changes from fetal to adult age, and reinforce the literature data indicating that mannose and galactose are transported by glucose carriers, while fructose is not.

Diphenyl diselenide and diphenyl ditelluride affect the rat glutamatergic system in vitro and in vivo.

The aim of this study was to investigate the possible involvement of the glutamatergic system in the toxicity of organochalcogens, since this is an important neurotransmitter system for signal transduction and neural function. The results indicated that 100 microM diphenyl diselenide (PhSe)(2) and diphenyl ditelluride (PhTe)(2) inhibit by 50 and 70% (P<0.05), respectively, [(3)H]glutamate binding in vitro. Acute administration of 25 micromol/kg (PhSe)(2) or 3 micromol/kg (PhTe)(2) caused a significant reduction in [(3)H]glutamate (30%, P<0.05) or [(3)H]MK-801 binding (30%, P<0.05) to rat synaptic membranes. These results suggest that (PhSe)(2) and (PhTe)(2) affect, in a rather complex way, the glutamatergic system after acute in vivo exposure in rats. In vitro, total [(3)H]GMP-PNP binding was inhibited about 40% at 100 microM (PhSe)(2) and (PhTe)(2). Acute exposure in vivo to (PhSe)(2) decreased the stable [(3)H]GMP-PNP binding to 25% and (PhTe)(2) to 68% of the control value (P<0.05, for both compounds). Simultaneously, the unstable binding of [(3)H]GMP-PNP was decreased about 30 and 50% (P<0.05, for both compounds) after exposure to (PhSe)(2) and (PhTe)(2), respectively. GMP-PNP stimulated adenylate cyclase (AC) activity significantly in control animals. (PhSe)(2)- and (PhTe)(2)-treated animals increased the basal activity of this enzyme, but GMP-PNP stimulation was totally abolished. These results suggest that the toxic effects of organochalcogens could result from action at different levels of neural signal transduction pathways, possibly involving other neurotransmitters besides the glutamatergic system.

BAL modulates glutamate transport in synaptosomes and synaptic vesicles from rat brain.

The therapeutic use of BAL (2,3-dimercaptopropanol) as treatment for poisoning has been halted by data suggesting serious neurotoxicity. This article is a report on the effects of BAL and other dithiols, DMSA (meso-2,3-dimercaptosuccinic acid) and DMPS (2,3-dimercaptopropane-1-sulfonic acid), on [3H]glutamate release and uptake by rat brain synaptosomes and [3H]glutamate uptake by synaptic vesicles. BAL (100 microM) inhibited glutamate uptake (30%) and stimulated its basal release (30%) in synaptosomes, without affecting K+-stimulated release. BAL also inhibited glutamate uptake by synaptic vesicles (up to 60%). DMPS and DMSA (100 microM) had no significant effects on these parameters. The data reported here provide some evidence of glutamate involvement in BAL-induced neurotoxicity by demonstrating direct effects of BAL on glutamatergic system modulation.

Chronic postnatal administration of methylmalonic acid provokes a decrease of myelin content and ganglioside N-acetylneuraminic acid concentration in cerebrum of young rats.

Levels of methylmalonic acid (MMA) comparable to those of human methylmalonic acidemia were achieved in blood (2-2.5 mmol/l) and brain (1.35 umol/g) of rats by administering buffered MMA, pH 7.4, subcutaneously twice a day from the 5th to the 28th day of life. MMA doses ranged from 0.76 to 1.67 umol/g as a function of animal age. Control rats were treated with saline in the same volumes. The animals were sacrificed by decapitation on the 28th day of age. Blood was taken and the brain was rapidly removed. Medulla, pons, the olfactory lobes and cerebellum were discarded and the rest of the brain ("cerebrum") was isolated. Body and "cerebrum" weight were measured, as well as the cholesterol and triglyceride concentrations in blood and the content of myelin, total lipids, and the concentrations of the lipid fractions (cholesterol, glycerolipids, phospholipids and ganglioside N-acetylneuraminic acid (ganglioside-NANA)) in the "cerebrum". Chronic MMA administration had no effect on body or "cerebrum" weight, suggesting that the metabolites per se neither affect the appetite of the rats nor cause malnutrition. In contrast, MMA caused a significant reduction of plasma triglycerides, but not of plasma cholesterol levels. A significant diminution of myelin content and of ganglioside-NANA concentration was also observed in the "cerebrum". We propose that the reduction of myelin content and ganglioside-NANA caused by MMA may be related to the delayed myelination/cerebral atrophy and neurological dysfunction found in methylmalonic acidemic children.

Chronic postnatal administration of methylmalonic acid provokes a decrease of myelin content and ganglioside N-acetylneuraminic acid concentration in cerebrum of young rats

Levels of methylmalonic acid (MMA) comparable to those of human methylmalonic acidemia were achieved in blood (2-2.5 mmol/l) and brain (1.35 æmol/g) of rats by administering buffered MMA, pH 7.4, subcutaneously twice a day from the 5th to the 28th day of life. MMA doses ranged from 0.76 to 1.67 æmol/g as a function of animal age. Control rats were treated with saline in the same volumes. The animals were sacrificed by decapitation on the 28th day of age. Blood was taken and the brain was rapidly removed. Medulla, pons, the olfactory lobes and cerebellum were discarded and the rest of the brain ("cerebrum") was isolated. Body and "cerebrum" weight were measured, as well as the cholesterol and triglyceride concentrations in blood and the content of myelin, total lipids, and the concentrations of the lipid fractions (cholesterol, glycerolipids, phospholipids and ganglioside N-acetylneuraminic acid (ganglioside-NANA)) in the "cerebrum". Chronic MMA administration had no effect on body or "cerebrum" weight, suggesting that the metabolites per se neither affect the appetite of the rats nor cause malnutrition. In contrast, MMA caused a significant reduction of plasma triglycerides, but not of plasma cholesterol levels. A significant diminution of myelin content and of ganglioside-NANA concentration was also observed in the "cerebrum". We propose that the reduction of myelin content and ganglioside-NANA caused by MMA may be related to the delayed myelination/cerebral atrophy and neurological dysfunction found in methylmalonic acidemic children

[Prediction of the effect of a triphasic contraceptive agent with norgestimate on acne]. / Predikce vlivu trífázového antikoncepcního prípravku s norgestimátem na akné.

OBJECTIVE: Prediction of complexion changes in users of triphasic oral contraceptive containing norgestimate. DESIGN: Analysis of data from a prospective multicentre open study. SETTING: Department of Obstetrics and Gynaecology, Charles University, Prague. METHODS: Acne severity was evaluated in users of a triphasic norgestimate-containing contraceptive within a six month period. Based on subjective evaluation of acne, three subgroups of patients were selected: A) users where acne improved or disappeared; B) users in whom acne deteriorated, C) users who newly developed acne. Differences between group A and the other groups were established in the proportion or distribution of parameters related to the etiology of acne: age, weight, weight changes during the study, presence of hirsutism, presence of a regular menstrual cycle prior to the start of hormonal contraception use, and smoking. RESULTS: The effect of the pill use on acne was assessed in a total of 3,990 women. Out of 1,201 women with acne before the start of the study, improvement or disappearance of acne during the study was reported by 940 users (subgroup A) (78.27%). In 221 women (18.40%), the extent of acne remained unaltered whereas it increased (subgroup B) in only 30 women (2.50%). Acne newly developed during the study in 49 women (subgroup C), i.e., in 1.2% of the whole group. Users showing deterioration of acne (subgroup B) were found to have hirsutism less frequently. The subgroup even showed a decrease in mean weight during the study. Users with newly developed acne were--compared with subgroup A--significantly older, had a lower weight at the start of the study, and showed a higher frequency of regular menstrual cycles prior to starting hormonal contraception. The differences in the incidence of clinical parameters in the subgroups reached only borderline statistical significance and, hence, are not relevant. CONCLUSION: An extensive multicentric study confirmed the beneficial effect of a triphasic norgestimate-containing contraceptive on complexion. The presence of clinical parameters related to the etiology of acne does not allow to predict the individual response of the skin to hormonal therapy.

[Clinical study of a triphasic contraceptive preparation (Norgestimate 180/215/250 micrograms + ethinylestradiol 35 micrograms) in a population of Czech women]. / Klinická studie s trífázovým antikoncepcním prípravkem (norgestimát 180/215/250 micrograms + etinylestradiol 35 micrograms) v populaci ceských zen.

OBJECTIVE: To assess the efficacy, acceptability and safety of triphasic oral contraceptive pill containing norgestimate 180/215/250 micrograms and ethinylestradiol 35 micrograms. DESIGN AND SETTING: Prospective, open-label, non-comparative, multicenter study in 409 centers in the Czech Republic. METHODS: Body weight, blood pressure, bleeding pattern, headaches, nausea, breast tenderness, acne, pregnancies and side effects were monitored before the start of the treatment, after three and six cycles of oral contraceptive use. Liver function tests were carried out before and after the treatment. RESULTS: Evaluating 26,432 cycles in 4,720 women the theoretical Pearl index was 0.15. There were no significant changes in body weight (61.45 kg before vs 61.58 kg after the treatment). There were clinically significant changes neither in the blood pressure nor in the liver function tests. Evaluating the bleeding pattern there were similar incidences of irregular bleeding/spotting before the treatment and up to the third treatment cycle (16.15%, resp. 17.86%); then the incidence dropped down (8.41% after the third cycle). Amenorhea was very rare (0.41% resp. 0.35% up to, resp. after the third cycle). Decreasing incidences compared to pretreatment state were observed for headache, breast tenderness and acne. The effect on acne was remarkable (28.3% of women complaining of acne before the treatment vs 6.51% after the six treatment cycles). There were no serious adverse events observed during this study. CONCLUSION: Triphasic oral contraceptive pill containing norgestimate and ethinylestradiol proved in a large multicenter study high both efficacy and acceptability.

Undernutrition decreases serine palmitoyltransferase activity in developing rat hypothalamus.

BACKGROUND/AIMS: Undernutrition reduces the hypothalamic ganglioside concentration. This may be attributed to some modifications in the contents of precursors of sphingolipid biosynthesis in undernourished rats. The present study evaluated the serine palmitoyl transferase activity (SPT; EC 2.3.1.50) during the development of the rat hypothalamus. This work also shows the L-[3-(14)C]serine metabolic labeling of hypothalamic sphingolipids in normal and undernourished rats at weaning. METHODS: The SPT activity was determined in microsomal fractions obtained from the hypothalamus of normal rats (diet: 25% protein) and pre- and postnatally undernourished rats (diet: 8% protein since pregnancy) at 21 days of gestational age and at 7, 14, and 21 days of postnatal life. RESULTS: The enzymatic activity was lower in the hypothalamus of undernourished than in the hypothalamus of control rats since the 7th postnatal day. Incorporation of the precursor L-[3-(14)C]serine into sphingolipid fraction was lower in the hypothalamus of undernourished rats than in the hypothalamus of control rats on the 21st postnatal day which coincided with the age of the highest difference in SPT activity between normal and undernourished rats. CONCLUSION: These results indicate that undernutrition reduces the biosynthesis of the main sphingolipids during the period of brain growth spurt.

[Injuries due to seat belts. Comments on a clinical case]. / Lesività da cinture di sicurezza. Considerazioni su di un caso clinico.

The authors report a case of associated injuries (thoracoabdominal trauma with multiple rib and sternum fractures, perforation of the small intestine, abdominal cutaneous ecchymosis) caused by a seat belt, and describe the possible seat-belt mechanisms of lesion in road accidents. Some clinical aspects are discussed; in particular the diagnostic problems concerning a seat-belt syndrome as well as the limits of effectiveness in the use of belts.

[One-year follow-up of women treated with transdermal administration of estrogen for post-castration and climacteric syndromes]. / Rocní sledování zen lécených transdermální aplikací estrogenu pro postkastracní a klimakterický syndrom.

Having gained preliminary knowledge in a selected group of 64 patients treated for three months by a transcutaneous form of estrogen therapy (Estraderm TTS) for postcastration and climacteric syndromes, the authors report in this paper on the results of a one-year follow-up of a series of 42 patients treated by ETTS 25 and 50 for the same diagnoses. Administration of ETTS makes it possible to take advantage of the therapeutic transdermal system for the transfer of 17 beta-estradiol directly into the blood stream. Estradiol in a daily dose of 25, 50 or 100 microgrammes is deposited in ethanol gel as a reservoir in a special sticking tape. From there it is absorbed across a microsporous membrane by molecular diffusion into the subcapillary plexus at a constant speed till an equilibration of the diffusion gradient between skin and the system is attained. For the aim of this study is to evaluate both the recession of the subjective as well as objective complaints in patients suffering from postcastration and climacteric syndromes and the reflection of the treatment in the blood levels of gonadotropins, estrogens, gestagens and cortisol and likewise the vaginal hormonal cytology. Both the systemic and local side-effects of treatment are subject to a careful study. On the basis of a comprehensive statistical study of these changes in every patient as well as in the whole series in the course of one year the authors reach the conclusion that the ETTS administration strikingly improves the subjective as well as objective complaints of the patients, and, in agreement with the literary data, objectively influences the laboratory results concerning especially the circulating levels of gonadotropins and of estradiol. In conclusion, the authors comment on the favourable contribution of this form of treatment to gynaecological practice in the therapy of postcastration, climacteric and estrogen-losing syndromes. A special modification of the record was prepared for this study when the running subjective evaluations of the effect of the treatment by the patient, as obtained in the course of directed interviews, as well as objective results of somatic and laboratory changes including the aggregate yearly evaluation of the effect of the treatment in every individual woman of the series are clearly arranged.