Arabidopsis kinome: after the casting.

Arabidopsis thaliana is used as a favourite experimental organism for many aspects of plant biology. We capitalized on the recently available Arabidopsis genome sequence and predicted proteome, to draw up a genome-scale protein serine/threonine kinase (PSTK) inventory. The PSTKs represent about 4% of the A. thaliana proteome. In this study, we provide a description of the content and diversity of the non-receptor PSTKs. These kinases have crucial functions in sensing, mediating and coordinating cellular responses to an extensive range of stimuli. A total of 369 predicted non receptor PSTKs were detailed: the Raf superfamily, the CMGC, CaMK, AGC and STE families, as well as a few small clades and orphan sequences. An extensive relationship analysis of these kinases allows us to classify the proteins in superfamilies, families, sub-families and groups. The classification provides a better knowledge of the characteristics shared by the different clades. We focused on the MAP kinase module elements, with particular attention to their docking sites for protein-protein interaction and their biological function. The large number of A. thaliana genes encoding kinases might have been achieved through successive rounds of gene and genome duplications. The evolution towards an increasing gene number suggests that functional redundancy plays an important role in plant genetic robustness.

The protein kinases AtMAP3Kepsilon1 and BnMAP3Kepsilon1 are functional homologues of S. pombe cdc7p and may be involved in cell division.

We identified an Arabidopsis thaliana gene, AtMAP3Kepsilon1, and a Brassica napus cDNA, BnMAP3Kepsilon1, encoding functional protein serine/threonine kinases closely related to cdc7p and Cdc15p from Schizosaccharomyces pombe and Saccharomyces cerevisiae, respectively. This is the first report of cdc7-related genes in non-fungal eukaryotes; no such genes have as yet been identified in Metazoans. The B. napus protein is able to partially complement a cdc7 loss of function mutation in S. pombe. RT-PCR and in situ hybridisation revealed that the A. thaliana and B. napus genes are expressed in both the sporophytic and the gametophytic tissues of the respective plant species and revealed further that expression is highest in dividing cells. Moreover, AtMAP3Kepsilon1 gene expression is cell cycle-regulated, with higher expression in G2-M phases. Our results strongly suggest that the plant cdc7p-related protein kinases are involved in a signal transduction pathway similar to the SIN pathway, which positively regulates cytokinesis in S. pombe.

Structure and expression of three src2 homologues and a novel subfamily of flavoprotein monooxygenase genes revealed by the analysis of a 25kb fragment from Arabidopsis thaliana chromosome IV.

Biological and computer-assisted analyses of a 25kb fragment from Arabidopsis thaliana chromosome IV led to the characterization of two multigene families and three novel orphan genes, not previously described. The first gene family named AtMO1-4 encodes monooxygenases, related to the prokaryotic salicylate hydroxylases. The second gene family contains three members, two on the analysed 25kb fragment and one on chromosome I. The latter three genes lack introns and are homologous to the previously studied Glycine max src2 gene which is overexpressed at low temperature. Gene expression and primary structure of the deduced proteins are described and compared. Three genes of unknown function, showing tissue specific expressions, are characterized on the 25kb fragment. Full length or partial cognate cDNAs have been sequenced for all the genes studied.

Five palmitoylated polypeptides in the 50 KDa range are not recognized by an antibody against ribulose-biphosphate-carboxylase-oxygenase in Chlamydomonas reinhardtii.

After incubation of Chlamydomonas reinhardtii cells with radioactive palmitic acid several labelled bands appeared after gel electrophoresis of delipidated protein extract. Among them, two bands (a major and a minor one) were detected in the 50 KDa range, which is the region where the LSU of the Rubisco (large sub-unit of the ribulose-biphosphate-carboxylase-oxygenase) was also found. Careful analyses by two-dimensional gel electrophoresis have shown that the five palmitate-labelled polypeptides detected in this region do not match with polypeptides immunoreacting with antibody against Rubisco. In addition, polypeptides labelled by palmitate cannot be immunoprecipitated with the same antibody further demonstrating that, in C. reinhardtii, the large sub-unit of Rubisco is not palmitoylated but unindentified proteins.

[Peritonitis caused by a purulent cyst of the urachus in a young woman]. / Péritonite due à un kyste suppuré de l'ouraque chez une jeune femme.

Urachal cysts are not exceptional and are observed more often in children. In adults, they may become infected and cause clinical symptoms associating subumbilical midabdominal pain, fever, guarding and leukocytosis. Intraperitoneal rupture is exceptional (21 published cases) and only 7 cases have involved adult female patients. The authors report the case of a 27-year old woman with peritonitis caused by rupture of a suppurated urachal cyst, 6 cm in diameter, for which diagnosis was established by perioperative ultrasound. The surgical procedure used consisted of total excision of the urachus, the umbilico-prevesical fascia and partial excision of the dome of the urinary bladder. Indeed, total excision is imperative because of the risk of malignant degeneration of this mass into an adenocarcinoma.

[Seroprevalence of the human immunodeficiency virus (HIV) in pregnant women coming for maternity consultation to the hospital center of Libreville (Gabon) in June 1990]. / Séroprévalence du virus de l'immunodéficience humaine (VIH) chez des femmes enceintes venues consulter à la maternité du centre hospitalier de Libreville (Gabon) en juin 1990.

The pregnant women as a control group was chosen in 1990 in order to estimate the HIV Seroprevalence in Libreville. As a result of that survey it appears that the prevalence of that retrovirus seems to remain under 2% and that those women are HIV-1-infected.

[Peritonitis due to a suppurating urachal cyst in a young woman. Review of the literature]. / Péritonite due à un kyste suppuré de l'ouraque chez une jeune femme. Revue de la littérature.

Peritonitis caused by a suppurating urachal cyst in a young woman. A review of the literature. Urachal cysts are not rare but occur much more often in children. In adults they may become infected and cause clinical symptoms including sub-umbilical mid-abdominal pain, fever, guarding and leukocytosis. Intraperitoneal rupture is rare (21 published cases) and only 7 cases have involved an adult female patient. The authors report the case of a 27 year old woman with peritonitis caused by rupture of a suppurating urachal cyst. 6 cm in diameter, for which the diagnosis had been established by pre-operative ultrasound. The surgical procedure carried out was total excision of the urachus, of the fascia between the umbilicus and the bladder, and partial excision of the dome of the bladder. Indeed total excision should have been carried out because of the risk of malignant degeneration of this mass to an adenocarcinoma.

[Stage III and IV epithelial ovarian cancers. Therapeutic problems]. / Les cancers épithéliaux de l'ovaire stades III et IV. Problèmes thérapeutiques.

Between 1986 and 1989 (4 years), 11 epithelial malignant tumours of the ovary were treated in the department of gynecology and obstetrics of the Libreville teaching hospital group. Epithelial tumours accounted for 78 per cent of malignant tumours in the adult. Burkitt's lymphoma predominated in young girls. Cancer of the ovary takes sixth place among female cancers in Gabon, with an incidence identical to that of cancer of the liver. Cases involved stage III and IV malignancies. Four patients died (36 per cent) and seven are still alive (63.6 per cent) with a mean survival of 25 months at the time of the study (the longest living patient having a survival of 5 years). The fullest possible initial surgical excision is essential in ensuring the greater efficacy of polychemotherapy (including Cisplatin), the only guarantee of total second look surgery. Monitoring of residual disease was based upon ultrasonography. Pelvic radiotherapy was used in the presence of a residual pelvic mass measuring less than 3 cm. Future efforts must be direct towards early detection, in particular since more than 45 per cent of our patients were aged under 30.

[Recurrent extra-uterine pregnancies. 63 cases treated at the Hospital Center of Libreville from 1985 to 1989]. / Les grossesses extra-utérines récidivantes. A propos de 63 cas survenus au Centre Hospitalier de Libreville de 1985 à 1989.

Ectopic implantation of the fertilised ovum, whether for the first time or as a recurrence, is not uncommon in this department. In a study in the Libreville Hospital group from 1985 to 1989, the authors found 828 cases of ectopic pregnancy (EP) including 63 recurrences, i.e. 7.61 per cent. These recurrences most often involved young women (26 per cent of cases) and nullipara (30%). The chief common etiology for the first occurrence remained tubal infection (57.28 per cent of cases). Treatment consisted most often of radical macrosurgery because of the advanced state of tubal disease, thus leading to the permanent sterilisation of 48 patients, i.e. 71.2 per cent of recurrences. Nineteen patients had a history of previous conservative surgery, including 8 homolateral recurrences (43 per cent). Reducing the incidence of such pathology essentially involves the prevention of gynecological infections, and in particular sexually transmitted diseases, as well as the possibility of early diagnosis of EP. Despite the fact that it seriously compromises the subsequent fertility of these young patients, total salpingectomy remains the treatment of choice for avoiding recurrences.

Tubal schistosomiasis as a cause of ectopic pregnancy in endemic areas?; a report of three cases.

Tubal schistosomiasis as a cause of ectopic pregnancy is uncommon. We are reporting three cases of tubal pregnancies in which the histopathological examination showed a bilharzial disease of the tube. Schistosomiasis to Schistosoma haematobium occurs in Gabon with an incidence of 8% to 44% of the adult population, and schistosoma ova have been found in 2.5% of histopathological examinations in removal of any genital tissue. Even if schistosomiasis was not the main causative agent of infertility, in this population which has the lowest fertility index in subsaharan Africa, it might impair an already altered tubal function by salpingitis. We suggest that parasitic examination should be made as a part of the management program of infertility and after an ectopic pregnancy in endemic areas.

[Eclampsia at the Hospital Center of Libreville. 53 cases among 41,285 deliveries from 1985 to 1989]. / L'éclampsie au Centre Hospitalier de Libreville. 53 cas pour 41,285 accouchements de 1985 à 1989.

Eclampsia is a serious complication at the end of pregnancy. This retrospective study over a 5-year period at the Libreville CHU hospital shows that the incidence of 0.12 p. cent is comparable to the incidence fond in other countries at a similar level of development. Promoting causes include youth of the patients, twin births, the "cold" season, the lack of follow-up after prenatal consultations. The consequences are increased maternal and perinatal death. Cesarean section remains the best way of dealing with an attack of eclampsia and improves both maternal and fetal prognosis. It is possible to eliminate, or at least reduce, the number of cases by developing conscientious and regular prenatal consultations.

[Serology of Chlamydia and ectopic pregnancies. Incidence of Fitz-Hugh-Curtis syndrome]. / Sérologie des Chlamydiae et grossesse extra-utérine. Fréquence du syndrome de Fitz-Hugh-Curtis.

The authors report a prospective study of anti-chlamydia trachomatis serology in extra-uterine pregnancies, which happened to coincide with an increase in the ectopic rate during the year 1989 (p less than 1.10(-6]. The subjects of the study were those patients operated on for ectopic pregnancy between the 1st January and the 31st May 1989. There were two control groups: the first were those that were delivered and the second were those pregnant women who were at risk of ectopic pregnancy because of their age, or the number of pregnancies they had had and their parity, without taking any account of the duration of the pregnancy. The level for sero-positive reading was 1 in 64 using an indirect immunofluorescent method (Spot IF, Bio Merieux). The results showed 81% sero-positive in those who had had ectopic pregnancies as against 63% in the control groups. The two control groups had identical readings. There was a significant difference statistically (p less than 0.01). There was no statistical difference in the incidence of HIV (human immunodeficiency virus) in the two groups (3% and 1%). The clinical study of the other tube showed no particular lesions. On the other hand, adhesions between the liver and the diaphragm (Fitz-Hugh-Curtis Syndrome) were demonstrated in 34% of those with ectopic pregnancy with a statistical significant level of igG above or equal to 1:128 (p 0.02). Perisplenitis was rare (3 cases). Histological finding of salpingitis isthmica nodosa in 49% of cases raises the problem of the pathology of chlamydial lesions being due to a host invader reaction. The increase in the incidence of ectopic pregnancy (1 in 44 deliveries) was accompanied by an increase in the prevalence of chlamydia trachomatis in the group with ectopics and the control groups. If the frequency of ectopics creates a major problem of public hygiene, the prevalence of chlamydia in the female population, apart from its effect on fertility, explains the action of sexually transmitted diseases as a factor in the heterosexual transmission of HIV in Africa.

PIP: A prospective study of antichlamydia trachomatis serology in extrauterine pregnancies which coincided with an increase in the rate of ectopic pregnancy during the year 1989 (p1.10-6) is reported. The subjects were patients operated on for ectopic pregnancy between January 1-May 31, 1989. There were 2 control groups, those who were delivered and those who were at risk for ectopic pregnancy because of their age or their parity. The level for seropositive reading was 1 in 64 using a direct immunofluorescent method (Spot IF, Bio Merieux). Results showed 81% seropositive in those who had ectopic pregnancies as compared with 63% in the control groups. The 2 control groups had identical readings. There was a significant difference statistically (p.01) but there was no statistical difference in the incidence of HIV among the 2 groups (3% and 1%). The clinical study of the other tube showed no specific lesions. However, adhesions between the liver and diaphragm (Fitz-Hugh-Curtis syndrome) were demonstrated in 34% of those with ectopic pregnancy with a statistically significant level of IgG or= 1:128 (p.02). Perisplenitis was rare (3 cases). Histological findings of salpingitis isthmica nodosa in 49% of the cases raises the problem of pathology of chlamydial lesions due to a host invader reaction. The increase in incidence of ectopic pregnancy (1 in 44 deliveries) was accompanied by an increase in prevalence of chlamydia trachomatis among the group of ectopics and the controls. If the frequency of ectopics creates a major problem with public hygiene, the prevalence of chlamydia among the female population, apart from its effect on fertility, explains the action of sexually transmitted diseases as a factor in the heterosexual transmission of HIV in Africa. (author's modified)

Identification of an NADP/thioredoxin system in Chlamydomonas reinhardtii.

The protein components of the NADP/thioredoxin system, NADP-thioredoxin reductase (NTR) and thioredoxin h, have been purified and characterized from the green alga, Chlamydomonas reinhardtii. The analysis of this system confirms that photoautotrophic Chlamydomonas cells resemble leaves in having both an NADP- and ferrodoxin-linked thioredoxin redox system. Chlamydomonas thioredoxin h, which is smaller on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than thioredoxin m from the same source, cross-reacted with antisera to thioredoxin h from spinach (Spinacia oleracea L.) and wheat germ (Triticum vulgaris L.) but not with antisera to m or f thioredoxins. In these properties, the thioredoxin h resembled a thioredoxin from Chlamydomonas, designated Ch1, whose sequence was reported recently (P. Decottignies et al., 1991, Eur. J. Biochem. 198, 505-512). The differential reactivity of thioredoxin h with antisera was used to demonstrate that thioredoxin h is enriched outside the chloroplast. The NTR was purified from Chlamydomonas using thioredoxin h from the same source. Similar to its counterpart from other organisms, Chlamydomonas NTR had a subunit size of approx. 36 kDa and was specific for NADPH. Chlamydomonas NTR effectively reduced thioredoxin h from the same source but showed little activity with the other thioredoxins tested, including spinach thioredoxin h and Escherichia coli thioredoxin. Comparison of the reduction of Chlamydomonas thioredoxins m and h by each of the endogenous thioredoxin reductases, NTR and ferredoxin-thioredoxin reductase, revealed a differential specificity of each enzyme for thioredoxin. Thus, NTR showed increased activity with thioredoxin h and ferredoxin-thioredoxin reductase with thioredoxins m and f.

Identification of an NADP/thioredoxin system in Chlamydomonas reinhardtii.

The protein components of the NADP/thioredoxin system, NADP-thioredoxin reductase (NTR) and thioredoxin h, have been purified and characterized from the green alga, Chlamydomonas reinhardtii. The analysis of this system confirms that photoautotrophic Chlamydomonas cells resemble leaves in having both an NADP- and ferrodoxin-linked thioredoxin redox system. Chlamydomonas thioredoxin h, which is smaller on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than thioredoxin m from the same source, cross-reacted with antisera to thioredoxin h from spinach (Spinacia oleracea L.) and wheat germ (Triticum vulgaris L.) but not with antisera to m or f thioredoxins. In these properties, the thioredoxin h resembled a thioredoxin from Chlamydomonas, designated Ch1, whose sequence was reported recently (P. Decottignies et al., 1991, Eur. J. Biochem. 198, 505-512). The differential reactivity of thioredoxin h with antisera was used to demonstrate that thioredoxin h is enriched outside the chloroplast. The NTR was purified from Chlamydomonas using thioredoxin h from the same source. Similar to its counterpart from other organisms, Chlamydomonas NTR had a subunit size of approx. 36 kDa and was specific for NADPH. Chlamydomonas NTR effectively reduced thioredoxin h from the same source but showed little activity with the other thioredoxins tested, including spinach thioredoxin h and Escherichia coli thioredoxin. Comparison of the reduction of Chlamydomonas thioredoxins m and h by each of the endogenous thioredoxin reductases, NTR and ferredoxin-thioredoxin reductase, revealed a differential specificity of each enzyme for thioredoxin. Thus, NTR showed increased activity with thioredoxin h and ferredoxin-thioredoxin reductase with thioredoxins m and f.

[Placental transfer of tetanus antibodies and protection of newborn infants]. / Transfert placentaire des anticorps antitétaniques et protection du nouveau-né.

Total IgG and tetanus antibodies were evaluated in 2 series of mother-child pairs: 50 in Paris and 134 in Africa. All pregnancies had been normal and birth weights greater than 3 kg. Cord blood mothers tetanus antibodies ratios were 1.5 in Paris and 0.98 in Libreville (p less than 0.01) respectively. Some African children were not protected, either due to the lack of response of their mothers to immunization (2.2%) or to an insufficient antibodies transplacental transport (2.9%), or to the lack of immunization of mothers (5.9%). On the contrary, all European children were protected, in spite of low maternal antibody levels. Likewise, in Paris cord blood IgG level was 12.24 g/l vs 9.42 in mothers (cord blood/mother ratio: 1.34) and in Africa 18.4 g/l in cord blood and 22.3 g/l in mothers (cord blood/mother ratio: 0.88; p less than 0.01). The correlations between maternal IgG levels and placental transfer rates indicate that the transplacental active transfer is limited by common high IgG levels in Africa, thus contributing to a decrease in protection of neonates, especially against tetanus in which humoral responses predominate.

Placental transfer of tetanus antibodies and protection of the newborn.

The aim of the study was to compare the placental transfer of tetanus toxoid antibodies (TTAB) and total IgG in Africa, where we had previously demonstrated a lack of transmission from mother to the newborn of measles antibodies. Two series of mother-child pairs, 45 in Paris and 134 in Libreville, Gabon, Central Africa, were measured after full-term pregnancies and normal deliveries. Means of ratios of cord/mother concentrations for TT AB and IgG were, respectively, 2.52 and 1.28 in Paris and 0.98 and 0.82 in Gabon. In 11 pairs from Libreville no TT AB were found in mother and cord blood, but in four other African newborns (3 per cent), the mother transmitted TT AB which were lower than protective level against tetanus. Other data (negative correlation between mother IgG and cord/mother ratio of corresponding TT AB concentrations, and better transmission of TT AB in the low range of maternal IgG) indicate that the limitation of active placental transfer of antibodies is related to the high maternal IgG level common in Africa.

Purification, characterization, and complete amino acid sequence of a thioredoxin from a green alga, Chlamydomonas reinhardtii.

Two thioredoxins (named Ch1 and Ch2 in reference to their elution pattern on an anion-exchange column) have been purified to homogeneity from the green alga, Chlamydomonas reinhardtii. In this paper, we described the properties and the sequence of the most abundant form, Ch2. Its activity in various enzymatic assays has been compared with those of Escherichia coli and spinach thioredoxins. C. reinhardtii thioredoxin Ch2 can serve as a substrate for E. coli thioredoxin reductase with a lower efficiency when compared to the homologous system. In the presence of dithiothreitol (DTT), the protein is able to catalyze the reduction of porcine insulin. Thioredoxin Ch2 is as efficient as its spinach counterpart in the DTT or light activation of corn NADP-malate dehydrogenase, but it only activates spinach fructose-1, 6-bisphosphatase at very high concentrations. The complete primary structure of the C. reinhardtii thioredoxin Ch2 was determined by automated Edman degradation of the intact protein and of peptides derived from trypsin, chymotrypsin, clostripain, and SV8 protease digestions. It consists of a polypeptide of 106 amino acids (MW 11,808) and contains the well-conserved active site sequence Trp-Cys-Gly-Pro-Cys. The sequence of the algal thioredoxin Ch2 has been compared to that of thioredoxins from other sources and has the greatest similarity (67%) with the thioredoxin from Anabaena 7119.

[Early prenatal diagnosis of diprosopic syncephalic joined twins]. / Diagnostic anténatal précoce de jumeaux conjoints syncéphaliques diprosopes.

The authors summarize the case of diprosopic syncephalic joined twins diagnosed at 22 weeks of pregnancy by ultrasonography performed because of hydramnios. The rate of separation anomalies of monozygotic twins is assessed by a review of the literature: from 1 to twenty to fifty thousands for joined twins to 1 per cent fifty thousand to fifteen millions for diprosopus. The etiology is the result of a late division of the egg between D12 and D16. Often an encephalic diprosopic joined twins cause elevated levels of maternal serum alpha protein. Early ultrasonography permits to consider a vaginal therapeutic abortion.

[Indications for cesarean section and their outcome at the Hospital Center in Libreville]. / Les indications de césarienne et leur évolution au Centre Hospitalier de Libreville.

Over a 16-year period and 113,739 deliveries, the rate of caesarean sections in the Department of Gynecology-Obstetrics of the Centre Hospitalier of Libreville (Gabon) reaches 1.79 p. cent. Since 1985, there is a highly significant (p less than 0.001) of that rate reaching 2.33 p. cent. A comparative study of two 4-year periods (1981-1984 and 1985-1988) permits to analyze the evolution of caesarean sections. The increase is the result of an improved diagnosis of the pathology during pregnancy, especially pre-eclampsia (6.2 p. cent of indications), a better obstetrical monitoring in pelvic deliveries (7 p. cent) and screening of fetal distress (11 p. cent). The indications remain stable in mechanical dystocias and placenta praevia (40 p. cent) and for scarred uterus (19 p. cent) the rate of which remains at 1 p. cent of the deliveries. The decreased rate of perinatal mortality which has benefited from the improvement of the quality of care is not directly related to the increased rate of caesarean sections: in Africa, caesarean sections are still performed in harmful conditions for saving the mother. Maternal mortality remains high (160 of 100,000 NB) and the mortality of caesarean sections is 9 for 1,000, with only 4 p. 1,000 related to the C. section itself and not to the pathology requiring the procedure. The mortality of caesarean section is 5 times higher than that of vaginal deliveries. Caesarean sections results in uterine ruptures during subsequent pregnancies (2 p. cent of scarred uterus). The increased of caesarean sections may only be considered within the scope of concomitant improvement of prenatal monitoring, obstetrical monitoring and neonatal medicine.