An eIF4E-interacting peptide induces cell death in cancer cell lines.

The eukaryotic initiation factor eIF4E is essential for cap-dependent initiation of translation in eukaryotes. Abnormal regulation of eIF4E has been implicated in oncogenic transformation. We developed an eIF4E-binding peptide derived from Angel1, a partner of eIF4E that we recently identified. We show here that this peptide fused to a penetratin motif causes drastic and rapid cell death in several epithelial cancer cell lines. This necrotic cell death was characterized by a drop in ATP levels with F-actin network injury being a key step in extensive plasma membrane blebbing and membrane permeabilization. This synthetic eIF4E-binding peptide provides a candidate pharmacophore for a promising new cancer therapy strategy.

Sea urchin embryo as a model for analysis of the signaling pathways linking DNA damage checkpoint, DNA repair and apoptosis.

DNA integrity checkpoint control was studied in the sea urchin early embryo. Treatment of the embryos with genotoxic agents such as methyl methanesulfonate (MMS) or bleomycin induced the activation of a cell cycle checkpoint as evidenced by the occurrence of a delay or an arrest in the division of the embryos and an inhibition of CDK1/cyclin B activating dephosphorylation. The genotoxic treatment was shown to induce DNA damage that depended on the genotoxic concentration and was correlated with the observed cell cycle delay. At low genotoxic concentrations, embryos were able to repair the DNA damage and recover from checkpoint arrest, whereas at high doses they underwent morphological and biochemical changes characteristic of apoptosis. Finally, extracts prepared from embryos were found to be capable of supporting DNA repair in vitro upon incubation with oligonucleotides mimicking damage. Taken together, our results demonstrate that sea urchin early embryos contain fully functional and activatable DNA damage checkpoints. Sea urchin embryos are discussed as a promising model to study the signaling pathways of cell cycle checkpoint, DNA repair and apoptosis, which upon deregulation play a significant role in the origin of cancer.

Protein translation during early cell divisions of sea urchin embryos regulated at the level of polypeptide chain elongation and highly sensitive to natural polyamines.

Protein synthesis was analysed following fertilisation in sea urchin. Fluctuations in the accumulation of neo-synthesised proteins were observed during the first cell cycles. Accurate translation analyses were performed from lysates prepared from early embryos. The lysates readily translated endogenous pre-initiated mRNAs allowing the determination of elongation rates in the absence of re-initiation in vitro. The translation capacity of embryo lysates increased 18-fold from 0 to 90 min after fertilisation, reflecting the increase in the amount of pre-initiated mRNAs during early development. Kinetics analysis at a short time interval during the course of early development (240 min) showed an overall increase in the elongation rate (> 10-fold) which is regulated by pauses in synchrony with the cell divisions. Elongation activity in the lysates was highly sensitive to the natural polyamines, spermine (ID50 = 0.2 mM) and spermidine (ID50 = 1.8 mM), indicating high potential regulation by the intracellular level of polyamines in embryos. The regulation in the elongation changes associated with the early embryo cell divisions is discussed in the light of the physiological fluctuations in polyamine concentrations.

Brefeldin A provokes indirect activation of cdc2 kinase (MPF) in Xenopus oocytes, resulting in meiotic cell division.

Brefeldin A, a fungal metabolite which disrupts protein traffic, provokes indirect activation of cdc2 protein kinase in Xenopus oocytes. Cdc2 protein kinase activation was judged by MPF (M-phase factor) transfer activity, histone H1 kinase activity, and phosphorylation in vivo of the guanine-nucleotide exchange complex EF-1 beta gamma delta. Oocytes resumed complete meiosis upon brefeldin A treatment. Cdc2 protein kinase, MAP kinase, cyclin B, MPF, and protein synthesis changes were all comparable in brefeldin A-treated oocytes and in progesterone-induced oocytes. ED50 for brefeldin A was 0.6 microM. Brefeldin A activation of cdc2 protein kinase occurs with a long time course. Simultaneous treatment of the oocytes at a subthreshold concentration of 1 nM progesterone and 30 microM brefeldin A considerably shortened the kinetics of maturation. Brefeldin A induction of maturation was sensitive to drugs that act on cAMP metabolism. ID50 for IBMX was 0.1 mM, compared to 1 mM for progesterone-treated oocytes. Brefeldin A inhibited protein traffic in oocytes as determined from protein export experiments. ID50 was between 0.1 and 1 microM. Our results give new insights into the possible mechanism of induction of meiotic maturation and further demonstrate that brefeldin A acts on cell cycle regulatory elements.

Infected infrarenal aortic aneurysms: when is in situ reconstruction safe?

Twenty-five infected infrarenal aortic aneurysms operated on between 1968 and 1989 were reviewed. They were classified into post-embolic (mycotic) aneurysms (group I), infective aortitis (group II), and infected atherosclerotic aneurysms (group III). Aortoduodenal fistulas were found in eight patients and aortocaval in two. Five patients were operated on in a state of shock, and 12 had preoperative positive blood cultures. Surgical procedures included in situ reconstruction of the aorta (n = 21) and extra-anatomic bypass associated with aneurysmal resection (n = 4). In 19 patients, prostheses were covered with omental flaps, and antibiotics were continued for more than 6 weeks in all patients. In patients who underwent in situ reconstruction, three deaths were related to the initial surgery. All surviving patients were regularly followed up, and none showed any sign of late septic recurrence. In patients who underwent extra-anatomic bypass, two died in the postoperative period, one underwent reoperation 2 years after the initial surgery, and the last patient is doing well. Positive postoperative blood cultures (n = 4) revealed persistent sepsis: two cholecystitis, one spondylitis, and one aortic infection. An exhaustive review of the literature was performed; clinical, bacteriologic, and operative features and results were analyzed; prognostic factors were evaluated; and a practical therapeutic approach was suggested. The importance of preoperative diagnosis, complete resection, debridement of infected tissues, omental flap coverage, and long-term antibiotic therapy with regular computerized tomographic scanning follow-up is stressed.

Analysis of risk factors for surgical wound infections following vascular surgery.

Although surgical wound infections (SWI) following implantation of prosthetic devices can be catastrophic and often require removal of the prosthesis, few studies have identified risk factors for these infections. We conducted a prospective multicenter study to identify risk factors for SWI. Of 561 vascular surgery patients enrolled in the study, 23 (4.1%) developed SWI. Multivariate analysis using logistic regression analyses identified surgery on lower extremities, delayed surgery, diabetes mellitus, past history of vascular surgery, and short antimicrobial prophylaxis (three doses of cefamandole) as independent risk factors for SWI. Consequences of SWI were serious; two (9%) died, 11 (48%) required reoperation, and five (22%) had their prosthesis removed. A risk index was developed using the independent risk factors for SWI identified by logistic regression analyses. When no risk factors were present, no SWI was observed (0 of 100), and the rate of SWI increased from 2.5% when one risk factor was present to 53.8% (7 of 13) when greater than or equal to 4 risk factors were present.

[Results of assays of estrogen, progesterone and androgen receptors in stage I and II adenocarcinoma of the endometrium]. / Résultats du dosage des récepteurs aux estrogènes, à la progestérone et aux androgènes dans les adénocarcinomes de l'endomètre aux stades cliniques I et II.

The prognosis for adenocarcinoma of the endometrium is dependent on the findings of the histopathological assessment of the tumor. In a retrospective study of patients treated in initially by surgery, the estrogen and progesterone receptors were assayed 89 times and the androgen receptors 64 times. No statistically significant correlation was found between any of these receptors and the degree of structural differentiation or degree of infiltration of the myometrium. The absence of any one of these receptors had no negative impact on the overall survival nor on recurrence-free survival. The same was true for the 9 tumors which were devoid of both estrogen and progesterone receptors. In the authors' experience, the results of these hormone assays did not provide any further information on which to base the prognosis of endometrial cancers.

M-phase-specific cdc2 protein kinase phosphorylates the beta subunit of casein kinase II and increases casein kinase II activity.

The M-phase-specific cdc2 (cell division control) protein kinase (a component of the M-phase-promoting factor) was found to activate casein kinase II in vitro. The increase in casein kinase II activity ranged over 1.5-5-fold. Increase in activity was prevented if ATP was replaced during the activation reaction by a non-hydrolysable analogue. Alkaline phosphatase treatment of the activated enzyme decreased the activity to the basal level. The beta subunit of casein kinase II was phosphorylated by cdc2 protein kinase at site(s) different from the autophosphorylation sites of the enzyme. Phosphoamino acid analysis showed that the beta subunit was phosphorylated by cdc2 protein kinase at threonine residues while autophosphorylation involved serine residues. Casein kinase II may be part of the cascade which leads to increased phosphorylation of many proteins at M-phase and therefore be involved in the pleiotropic effects of M-phase-promoting factor.

In vivo progesterone regulation of protein phosphatase activity in Xenopus oocytes.

Exogenous beta casein, previously phosphorylated in vitro by protein kinase A and casein kinase II, was microinjected into Xenopus oocytes to monitor in vivo protein phosphatase activities. Phosphatase activities were 1.6 and 3.4 fmol/min/oocyte, respectively, for beta casein phosphorylated by casein kinase II and beta casein phosphorylated by protein kinase A. Progesterone induced an early decrease (35% after 10 min) in phosphatase activity restricted to the protein kinase A sites of beta casein.

Protein phosphatase activities in vivo in Xenopus laevis oocyte: inhibition by okadaic acid.

Protein phosphatase activities were analyzed in vivo in Xenopus oocytes. The dephosphorylation of microinjected beta casein was inhibited when the tumor promoter okadaic acid was microinjected into oocytes. Inhibition was dose dependent and reversible; 50% of activity was recovered 15-30 minutes after microinjection.

Purification of a p47 phosphoprotein from Xenopus laevis oocytes and identification as an in vivo and in vitro p34cdc2 substrate.

This paper describes the purification of a 47 kDa protein from Xenopus laevis oocytes that becomes phosphorylated when the oocytes undergo meiotic maturation. This protein (p47) is part of a high molecular mass complex containing at least two other proteins of molecular mass 30 and 36 kDa. This complex can be isolated from stage VI oocytes before maturation. We obtained a pattern for phosphopeptides in p47 phosphorylated in vivo very similar to that of the purified protein phosphorylated in vitro by p34cdc2 (a H1 kinase which is a component of the M-phase promoting factor) and [gamma-32P]ATP. Therefore, the purified p47, already described as a marker of MPF activity, is the first reported in vivo substrate for the cell division control kinase.

Nephroblastomatosis: missed diagnosis.

Nephroblastomatosis, a congenital lesion of infants and children, is marked by the persistence of metanephric blastema in the kidney. Computed tomography (CT) has previously been reported to be the best way to image these precancerous lesions. The authors discuss the radiologic and surgical implications of a case of macroscopically visible nephroblastomatosis demonstrated at histologic examination but not detected with CT in the contralateral kidney of a patient with Wilms tumor.

[Prevention using cefotetan of post-partum and post-abortion infectious complications in intra-uterine procedures]. / Prévention par l'utilisation du cefotetan des complications infectieuses du post-partum et du post-abortum dans les manoeuvres endo-utérines.

A prospective, randomized study was conducted in 113 women to evaluate the effect of antibiotic prophylaxis with cefotetan versus no prophylaxis in the prevention of post-partum and post-abortion sepsis. The administration of a single 2 g dose of cefotetan at the time of surgery significantly reduced the number of infectious complications, removal of the placenta or an internal inspection were carried out.

[Abnormality of the pyelo-ureteric junction revealed by a prostatic adenoma (author's transl)]. / Anomalie de jonction pyélo-urétérale révélée par un adénome prostatique

An acquired hydronephrosis proximal to obstruction caused by a proastatic adenoma regressed after surgical removal of the latter. On this basis, the authors review the lesions predisposing to abnormalities of the junction and the circumstances which may provoke a hydronephrosis.