p53 activation domain 1 is essential for PUMA upregulation and p53-mediated neuronal cell death

The p53 tumor suppressor gene has been implicated in the regulation of apoptosis in a number of different neuronal death paradigms. Because of the importance of p53 in neuronal injury, we questioned the mechanism underlying p53-mediated apoptosis in neurons. Using adenoviral-mediated gene delivery, reconstitution experiments, and mice carrying a knock-in mutation in the endogenous p53 gene, we show that the transactivation function of p53 is essential to induce neuronal cell death. Although p53 possesses two transactivation domains that can activate p53 targets independently, we demonstrate that the first activation domain (ADI) is required to drive apoptosis after neuronal injury. Furthermore, the BH3-only proteins Noxa and PUMA exhibit differential regulation by the two transactivation domains. Here, we show that Noxa can be induced by either activation domain, whereas PUMA induction requires both activation domains to be intact. Unlike Noxa, the upregulation of PUMA alone is sufficient to induce neuronal cell death. We demonstrate, therefore, that the first transactivation domain of p53 is indispensable for the induction of neuronal cell death.

Phenotypic expression of pyruvate kinase deficiency and protection against malaria in a mouse model

The recombinant congenic mouse strains AcB55 and AcB61 are extremely resistant to malaria (Plasmodium chabaudi AS) despite the presence of susceptibility alleles at the known Char1/Char2 resistance loci. Resistance in AcB55 and AcB61 is controlled by a locus on chromosome 3 (Char4) shown to be allelic with or tightly linked to a loss-of-function mutation in pyruvate kinase (Pklr). AcB55 and AcB61 show important splenomegaly prior to infection caused by the expansion of the red pulp, and display histological signs of extramedullary erythropoiesis in the liver. Examination of splenic cell populations by flow cytometry demonstrates elevated numbers of TER119-positive erythroid precursor cells (>30% of total spleen cells), while RNA expression studies show elevated expression of erythrocyte-specific transcripts such as globin, transferrin receptor, and Nramp2/Slc11a2 in the spleen of both strains. Hematological profiling in both strains is consistent with the presence of anemia as evidenced by low total erythrocyte counts, decreased hemoglobin, as well as abnormally high numbers of circulating reticulocytes (15-20%). These results strongly suggest that the mutant Pklr allele (Pklr(269A)) of AcB55/61 strains causes hemolytic anemia compensated by constitutive erythropoiesis, which in turn protects the mice against P. chabaudi infection. The possible molecular basis of the Pklr protective effect is discussed and is under current investigation in these two strains.

[Endorectal sonography in gynecology: usefulness and diagnostic accuracy]

OBJECTIVE

The aim of this study was to assess feasibility and diagnostic accuracy of endorectal sonography (ERS) in comparison with transabdominal sonography (TAS) in women with a contraindication to endovaginal sonography (EVS).

PATIENTS AND METHODS

ERS was proposed to 32 patients in the immediate continuation of TAS. It was performed either with a specific probe or with a vaginal probe. The protocol included a complete evaluation of pelvic structures observed with both sonographic techniques.

RESULTS

After counselling and assent, 29 of the 32 patients (90%) accepted ERS. The examination was regarded as complete in 28 cases. ERS confirmed the absence of pelvic anomaly in the 12 cases of normal TAS. ERS modified diagnosis in 5 of the 8 cases of anechoic ovarian cysts seen in TAS. In 4 cases, PCOs not seen in TAS were identified. Two partially sub-mucous myomas not recognized by TAS were diagnosed by ERS. Sensibility, specificity, positive predictive value (PPV) and negative predictive value (NPV) of TAS and ERS were 38,4 and 87,5%, 41,6 and 100%, 50 and 100%, 40 and 85,7% respectively.

DISCUSSION AND CONCLUSION

These findings suggest ERS is an effective diagnostic tool in pelvic exploration when EVS cannot be performed. It should be widely proposed after information and assent.

The Proapoptotic Gene SIVA Is a Direct Transcriptional Target for the Tumor Suppressors p53 and E2F1

The p53 tumor suppressor gene is believed to play an important role in neuronal cell death in acute neurological disease and in neurodegeneration. The p53 signaling cascade is complex, and the mechanism by which p53 induces apoptosis is cell type-dependent. Using DNA microarray analysis, we have found a striking induction of the proapoptotic gene, SIVA. SIVA is a proapoptotic protein containing a death domain and interacts with members of the tumor necrosis factor receptor family as well as anti-apoptotic Bcl-2 family proteins. SIVA is induced following direct p53 gene delivery, treatment with a DNA-damaging agent camptothecin, and stroke injury in vivo. SIVA up-regulation is sufficient to initiate the apoptotic cascade in neurons. Through isolation and analysis of the SIVA promoter, we have identified response elements for both p53 and E2F1. Like p53, E2F1 is another tumor suppressor gene involved in the regulation of apoptosis, including neuronal injury models. We have identified E2F consensus sites in the promoter region, whereas p53 recognition sequences were found in intron1. Sequence analysis has shown that these consensus sites are also conserved between mouse and human SIVA genes. Electrophoretic mobility shift assays reveal that both transcription factors are capable of binding to putative consensus sites, and luciferase reporter assays reveal that E2F1 and p53 can activate transcription from the SIVA promoter. Here, we report that the proapoptotic gene, SIVA, which functions in a broad spectrum of cell types, is a direct transcriptional target for both tumor suppressors, p53 and E2F1.

The Efficacy and Sequencing of a Short Course of Androgen Suppression on Freedom From Biochemical Failure When Administered With Radiation Therapy for T2-T3 Prostate Cancer

PURPOSE

We evaluated the benefits and sequencing of androgen suppression (AS) administered with external beam radiation therapy (EBRT) in T2-T3 prostate cancers.

MATERIALS AND METHODS

Between 1990 and 1999, 481 patients were entered in 2 successive, prospective, randomized studies, including 161 in the study 1 and 325 in study 2. Eligible patients had clinical stages T2-T3 prostate cancer. In the first study (L-101) subjects were randomly allocated among EBRT alone (group 1), EBRT preceded by 3 months of AS (group 2), and neoadjuvant, concomitant and adjuvant AS for a total of 10 months (group 3). In the second study (L-200) we analyzed neoadjuvant and concomitant AS (total 5 months) vs neoadjuvant, concomitant and short course adjuvant (total 10 months) AS with EBRT. In each study we used a total AS (a luteinizing hormone-releasing hormone agonist plus an antiandrogen) and a standard dose of radiation therapy at that time. Patient characteristics were well balanced in regard to age, stage, prostate specific antigen and Gleason score. No biochemical evidence of disease (BNED) was defined as an end point according to the Vancouver rule.

RESULTS

In the study 1 at a median followup of 5 years 7-year biochemical-free survival rates were 42%, 66% and 69% in groups 1 to 3, respectively. BNED was significantly different between groups 1 and 2 (p = 0.009) and between groups 1 and 3 (p = 0.003) but not between groups 2 and 3 (p = 0.6). Multivariate analysis using a Cox proportional hazards model showed an HR of 6.1 for Gleason score (p = 0.001), 1.4 for PSA (p = 0.002), 0.5 for group 1 vs group 2 (p = 0.01) and 0.35 for group 1 vs group 3 (p = 0.008). In study 2 BNED at 4 years was 65%. There was no significant difference between arms 1 and 2 (p = 0.55).

CONCLUSIONS

The analysis of study 1 shows a benefit of using a short course of neoadjuvant AS with EBRT vs EBRT alone for localized T2-T3 prostate cancers. Moreover, in each study adding a short course of adjuvant AS after neoadjuvant 1 provided no more advantage in these patients.

Stereoscopic processing in the human brain as a function of binocular luminance rivalry

We investigated the neural substrates of a recent model of human stereodepth perception by obtaining measurements of regional cerebral blood flow (rCBF) using PET. Subjects experienced the perceptual properties of stereopsis by viewing rival-luminance stereograms displaying an identical random-dot pattern in their central portion while the backgrounds exhibited correspondent dots contrasting in black/white luminance. The stereoscopic vision induced by retinal luminance rivalry coincided with a significant elevation of rCBF in the dorsal visual pathway. Area V5 (MT) was activated bilaterally by the experimental condition while the remaining active loci were restricted to the right hemisphere. The neural sites that responded to this novel stereoscopic stimulus are similar to those activated by traditional stereograms containing horizontal disparities.

Gestational and lactational feeding strategies for gilts: Growth, carcass characteristics and meat quality of the progeny

This study was conducted to determine whether feeding gilts (1) at or above their National Academy of Sciences-National Research Council (NAS-NRC 1998) requirements during gestation, and (2) to lose a moderate (~10%) or large (~17%) amount of maternal protein during lactation had a residual effect on their progeny’s growth, carcass characteristics and pork quality at market weight. From each litter, the heaviest and lightest barrows and gilts were selected. The progeny of gilts fed above their requirements during gestation, and those that lost the least body protein during lactation were heavier at weaning; +0.3 kg (P < 0.05) and +0.5 kg (P = 0.01), respectively. However, these liveweight differences, which were associated with the gestation and lactation effects, were no longer evident (P > 0.05) at day 35 or 85 post-weaning. But at slaughter, these animals had thinner (P < 0.01) fat thickness and higher (P < 0.05) predicted salable meat yield. Independently of the gestation and lactation treatments, and compared to the low-weaning-weight pigs, the high- weaning-weight pigs maintained their weight advantage (P < 0.01 at day 35 (+ 2.8 kg) and day 85 (+ 5.4 kg) post-weaning), took 4.5 fewer days (P < 0.01) to reach market weight, but had similar (P > 0.05) carcass characteristics and pork quality. Key words: Gilts, gestational and lactational protein, litter, growth, carcass characteristics and meat quality

Growth performance, carcass and pork quality of finisher pigs fed oat-based diets containing different levels of beta-glucans

A study was undertaken to investigate the growth performance and carcass and meat quality of pigs (BW = 52 to 108 kg) fed oat-based (Avena sativa L.) diets containing four levels of mixed-linkage (1 --> 3), (1 --> 4)-beta-D-glucans. One hundred sixty pigs-80 barrows and 80 gilts (average starting BW = 52.7 kg)--were allocated to one of five diets: a wheat-barley-based control diet and four experimental diets. The groats of Marion, a covered oat, and OT789, a hulless oat, were used to formulate four isonitrogenous and isocaloric diets to achieve 4.1,3.3, 2.1, or 1.6% total /beta-glucans (as fed). Growth performance (daily gain and gain to feed ratio) was not affected (P > 0.05) by the different levels of beta-glucans. Carcass yield, although lower (P < or = 0.05) for pigs fed the control diet, was similar (P > 0.05) for pigs fed any of the experimental diets. Cutout yields were also alike (P > 0.05) across the five diets. Beta-glucan content had no effect (P > 0.05) on the longissimus muscle area, or, by and large, on the proportions of commercial cuts; the only exceptions were a commercial picnic from pigs fed the 2.1% diet lower (P < 0.05) relative to all other diets and a lower (P < 0.5) commercial loin from pigs fed diets 4.1 or 3.3% relative to the control diet. Furthermore, the relative proportions oftotal lean, total bone, and total dissectable fat in the four lean cuts (picnic, butt, loin, and ham) were not different (P > 0.05) among the five diets. For pigs fed 4.1% beta-glucans, the proportion of lean in each of the four major cuts was lower (P < 0.05). No differences (P > 0.05) associated with the level of beta-glucans were detected for either the initial or ultimate pH mean values, the subjective assessment of color or structure of the longissimus muscle, or the instrumentally measured color (L value). Similarly, drip loss was not influenced (P > 0.05) by the level of beta-glucans in the diets. Soluble protein did differ (P < 0.05) among the high- to low-beta-glucans diets. No differences (P > 0.05) associated with diets were found for fat hardness and shear values of grilled pork chops. Chemical fat of the longissimus muscle from pigs fed 4.1, 3.3, or 2.1% beta-glucans was lower (P < 0.05) compared to pigs fed the control or 1.6% beta-glucans diets. In summary, no evidence of detrimental effect of beta-glucans in oat-based diets, particularly at levels below 4%, was detected, lending support for the inclusion of oat into finisher diets.

Successive measurements of carcass fat and loin muscle depths at the same site with optical probes

The effect of successive measurements at the same site studied on 286 pork carcasses with three optical grading probes was small but different between probes. This effect was inefficiently corrected by regression. It is recommended that successive measurements be taken on immobilized carcasses and that balance be maintained in the order of probe use. Key words: Pork, backfat, muscle depth, successive probing

Susceptibility to malaria as a complex trait: big pressure from a tiny creature

Malaria, which is a major infectious disease worldwide, is caused by the Plasmodium parasite, one of the longest-known parasites infecting humans. The malaria situation is complicated by the emergence of drug resistance and the lack of an effective vaccine. Genetic factors play a key role in disease susceptibility, progression and outcome. Interestingly, an increasing large number of polymorphisms associated with resistance and susceptibility in humans have been found in proteins from erythrocytes, the site of Plasmodium replication. Some of these deleterious alleles have been selected by direct genetic pressure from the parasite in endemic areas of malaria. A number of additional gene effects have been mapped both in humans and in mice using population studies and experimental models of malaria, respectively. These recent studies have started to reveal additional aspects of the complex host-parasite interactions.

Apoptosis-inducing factor is involved in the regulation of caspase-independent neuronal cell death

Caspase-independent death mechanisms have been shown to execute apoptosis in many types of neuronal injury. P53 has been identified as a key regulator of neuronal cell death after acute injury such as DNA damage, ischemia, and excitotoxicity. Here, we demonstrate that p53 can induce neuronal cell death via a caspase-mediated process activated by apoptotic activating factor-1 (Apaf1) and via a delayed onset caspase-independent mechanism. In contrast to wild-type cells, Apaf1-deficient neurons exhibit delayed DNA fragmentation and only peripheral chromatin condensation. More importantly, we demonstrate that apoptosis-inducing factor (AIF) is an important factor involved in the regulation of this caspase-independent neuronal cell death. Immunofluorescence studies demonstrate that AIF is released from the mitochondria by a mechanism distinct from that of cytochrome-c in neurons undergoing p53-mediated cell death. The Bcl-2 family regulates this release of AIF and subsequent caspase-independent cell death. In addition, we show that enforced expression of AIF can induce neuronal cell death in a Bax- and caspase-independent manner. Microinjection of neutralizing antibodies against AIF significantly decreased injury-induced neuronal cell death in Apaf1-deficient neurons, indicating its importance in caspase-independent apoptosis. Taken together, our results suggest that AIF may be an important therapeutic target for the treatment of neuronal injury.

Complex genetic control of susceptibility to malaria in mice

Malaria is a major infectious disease worldwide, with over 1 million deaths in African children every year. The molecular pathways of pathogenesis of the Plasmodium parasite and the host mechanisms of defense against this infection remain poorly understood. Epidemiological studies, together with linkage analyses in endemic areas have clearly pointed at a genetic component of innate susceptibility and severity of disease. In humans, this genetic trait is complex, and has been studied in a mouse experimental model over the past few years. Inbred strains of mice show different degrees of susceptibility to infection with Plasmodium chabaudi, and the genetic component of these inter-strain differences has been studied in standard informative backcross and F2 populations, as well as in recombinant inbred strains and more recently, in recombinant congenic strains. These studies have shown that genetic susceptibility to malaria is also complex in mice, and have led to the mapping of major susceptibility Char (Chabaudi resistance) loci, located on chromosomes 9 (Char1), 8 (Char2), 17 (Char3) and 3 (Char4).

[Fetal macrosomia: management, obstetrical and neonatal results. Multicenter case-control study in 15 maternity hospitals in Paris and the Ile de France area]

OBJECTIVE

To study the perinatal management of fetal macrosomia (FM) and the obstetrical and neonatal results related to FM in the Ile de France area.

MATERIALS AND METHODS

Case-control study from the fifteenth of July to the fifteenth of September 1999 in fifteen maternity in Paris and the Ile de France area. All singletons, without malformation, weighing more than 4,000 grams, born after 37 weeks of pregnancy during the study were included. The control group had the same inclusion and exclusion criteria (except the birth-weight) and was defined by the next delivery of same parity.

RESULTS

384 FM and 384 controls have been included. Usual risk factors of macrosomia have been found. The screening of gestational diabetes was realised in 56.8% and FM was suspected before delivery in 59.3% in the FM group. In cases of FM, the midwife was alone at the time of delivery in 53.4% of spontaneous vaginal delivery. FM was associated with a longer labour and a more frequent use of oxytocin. There was six times more severe perineal tears (1.7 vs 0.3%; p = 0.05) for women with FM whereas the rate of haemorrhage at delivery was the same in both groups. Cesarean section' rate before and during labor was higher in the FM group whereas instrumental extraction was not different. In this study, FM was not associated with an excess of fetal morbidity (injury, Apgar score, pH cord) even if we found ten times more shoulder dystocia.

CONCLUSION

Complications related to FM were mainly maternal in this study. Some recommendations accounting fetal macrosomia were not widely adopted as screening of gestational diabetes or necessity to have a whole obstetric team at the time of delivery.

The quality and yield characteristics of Canada B3 beef carcasses exhibiting medium to good muscling

Forty-nine Canada B3 carcasses meeting Canada quality grade requirements, but exhibiting medium to good muscling, 12 Canada A and 13 Canada AA carcasses were selected to determine the eating attributes of LL and SM steaks and their saleable meat yield. Canada B3 LL steaks had lower (P = 0.01) shear force value than Canada A and Canada AA LL steaks. For the SM steaks, there was no difference (P > 0.05). The eating attributes of Canada B3 LL steaks (softness, initial tenderness, flavour intensity, chewiness and rate of breakdown) were superior (P < 0.001) to those of Canada A or Canada AA LL steaks. Two attributes (juiciness and amount of perceptible connective tissue) were not different (P > 0.05). Differences in the eating attributes of Canada B3 SM steaks (softness, tenderness and flavour) were also observed (P < 0.05). The saleable meat yield of Canada B3 carcasses was lower (P < 0.05) than that of Canada 1 carcasses, but superior (P < 0.05) to Canada 2 or Canada 3 carcasses. Canada B3 carcasses had a higher (P < 0.05) proportion of front quarter and a lower (P < 0.05) proportion of hindquarter than Canada 1 carcasses. Canada B3 carcasses had lower yields (P < 0.05) of the more valuable cuts and higher yields (P < 0.05) of less valuable cuts, particularly, when compared to Canada 1 carcasses. Key words: Canada beef grade, quality, yield, muscling, eating attributes

Suicidal ideation and self-determination in institutionalized elderly

The right to self-determination is central to the current debate on rational suicide in old age. The goal of this exploratory study was to assess the presence of self-determination in suicidal institutionalized elderly persons. Eleven elderly persons with serious suicidal ideations were matched according to age, sex, and civil status with 11 nonsuicidal persons. The results indicated that suicidal persons did not differ from nonsuicidal persons in level of self-determination. There was, however, a significant difference between groups on the social subscale. Suicidal elderly persons did not seem to take others into account when making a decision or taking action. The results are discussed from a suicide-prevention perspective.

'Seeing' in the blind hemifield following hemispherectomy

Destruction of the striate cortex has traditionally been thought to lead to permanent blindness in the contralateral visual field and to the dogma that this region is indispensable for vision in primates. For over 25 years now, evidence has been accumulating that hemianopic human subjects and monkeys possess wide-ranging residual visual capacities or 'blindsight' in the blind part of their visual field. For some researchers, isolated islands of the striate cortex have been associated with patches of degraded vision and made responsible for blindisight. Artefacts such as light scatter, criterion effects, macular sparing, eccentric fixation and minute eye movements have also been linked with the residual vision. For others, the fact that certain aspects of the visual information can be processed without the geniculostriate pathway suggests mediation by the visual subsystems such as extrastriate visual cortical areas which receive visual information via subcortical pathways, that escaped the cortical damage. Subjects who have had a whole cerebral hemisphere removed or disconnected (for the treatment of uncontrollable epilepsy) and who show residual vision in their blind field offer a remarkable opportunity to help clear the controversy regarding the neural substrate of blindsight. Because it is certain that no functional striate or extrastriate cortex remains on the ablated side, these subjects have contributed significantly to identifying the critical pathways involved in blindsight.

Trafficking of surface-linked and encapsulated liposomal antigens in macrophages: an immunocytochemical study

Liposomal antigens are potent adjuvants of humoral and cell-mediated immunity. Although this property requires as an essential condition a physical association between the antigen and the phospholipid vehicle, the nature of the association, i.e., encapsulation or surface linkage, markedly influences the outcome of the elicited response. Available evidence suggests that macrophages are involved in this fine tuning of the immune response in a manner that is not yet clearly established. It is postulated that this might be related to their capacity to interact differently with surface-linked and encapsulated formulations. Using conalbumin as a model antigen, we address the question by analyzing the movements of encapsulated and surface-linked antigen as well as those of MHC-II molecules in macrophages in a pulse-chase immunoelectron microscopic study carried out over a 24-hr period. The antigen was followed using a polyclonal serum specifically raised against fragmented conalbumin (fCA) that allows the detection of processed antigen and of some MHC-peptide complexes. The results indicate that, in macrophages, the two liposomal formulations affect macrophage morphology in distinct ways and circulate through the various subcellular compartments with different kinetics. On the basis of the overall results, we conclude that surface-linked antigen gains access less readily to the endogenous presentation pathway than encapsulated antigen but can favor a more sustained activation of the immune system through its production of exosome-like structures and its more thorough utilization of the MHC-II pathway.