[Pregnancy and delivery among adolescents under 15: a study of 181 cases in French Guiana]

OBJECTIVE

The purpose of this study were to determine the effects and consequences of premature pregnancy and childbirth among adolescents under 15 years of age in French Guyana.

MATERIAL AND METHODS

A retrospective field-case study between the 1(st) and the 31(st) December 2001 identified 181 births among adolescents aged 14 years and under. Comparisons were made with 181 births among 18-year-old first-time mothers taking place over the same period.

RESULTS

1.55% of all births in the maternity ward at St Laurent-du-Maroni Hospital involved adolescents under the age of 15. 24.6% of these young mothers were enrolled in secondary school, 21% were beneficiaries of the national social security health insurance and 61% of them were born outside Guyana. Pre-natal monitoring was less frequent among the group of teenage mothers, and preterm labor (0.04 < p < 0.05), anemia (0.02 < p < 0.03) and Chlamydiae trachomatis infections (0.03 < p < 0.04) are more frequent. There is no significant difference regarding high blood pressure, diabetes, or infectious diseases (except from Chlamydiae) or regarding labor and delivery. Mean birth weight was lower (p = 0.01) and the Apgar score was more often less than 7 at the first minute (p < 0.05) among newborn of teenage mothers.

CONCLUSION

While pregnancies among younger teenagers appear to indicate a higher level of associated medical problems, a more thorough pre-natal check-up program would certainly reduce the number of problem related cases. The extremely high proportion of teenage pregnancies in the West of French Guiana has become a major public health issue for the entire region.

[Severe maternal anemia and pregnancy outcome]

OBJECTIVES

The aim of this study was to determine the effects of severe antenatal maternal anemia on pregnancy outcome.

MATERIAL

and methods. A retrospective study comparing 2 groups of pregnant women: 111 (pregnant women) with anemia (Hb < 8 g/dl), 111 non- anemic pregnant women (Hb >10 g/dl). Clinical and biological characteristics for both groups were compared. Data on the newborn babies were collected.

RESULTS

In the anemic group: iron deficiency was the most common cause of anemia (92.7%). There was no significant difference between the 2 groups with respect to age or parity. Maternal anemia was found to be significantly associated with more frequent preterm birth (29.2% vs 9.2%) and increased low birth weight (2933 g vs 3159 g).

DISCUSSION

The literature is not conclusive on the influence of anemia in pregnant women. More frequent preterm birth and low birth weight have been reported in the majority of studies considering mild to moderate maternal anemia (in contrast to our study where the mothers had severe anemia). Many studies indicated that routine iron supplementation during pregnancy may have beneficial effects on pregnancy outcome. Severe anemia in pregnancy may have adverse effects for the newborn and should be treated or prevented early in pregnancy.

[HTLV1 infection and pregnancy]

OBJECTIVE

We report an epidemiological study with an analysis of the risk factors of the HTLV-1 seroprevalence in pregnant women and their children in the town of St Laurent du Maroni, French Guyana.

MATERIAL AND METHOD

HTLV-1 seroprevalence and risk associated factors were first studied in all the pregnant women having delivered at St. Laurent between July 1991 and June 1993. Then, a retrospective analysis was performed in the children, aged between 18 months and 12 years old, born from HTLV-1 infected mothers, focusing especially on the duration of breast feeding and the level of HTLV-1 anti body titers and proviral load.

RESULTS

The global HTLV-1 seroprevalence was 4.4% (75/1727) but it was more prevalent among ethnic groups of African origin such as the Noir Marron population (5.5%) and Haitians (6.3%). In the Noir-Marron population, which represents 70% of the studied population, HTLV-1 seropositivity was associated with a maternal age of>35 years, prior miscarriage, prior cesarean section, parity>4, gravidity>6 and negative rhesus factor. After logistic regression, HTLV-1 seropositivity remained associated with gravidity>6 and negative rhesus factor. Out of the 216 children born from 81 HTLV-1 infected mothers, only 21 were found to be HTLV-1 seropositive, giving a crude HTLV-1 transmission rate of 9.7% while among the 180 breast-fed children 10.6% were HTLV-1 seropositive. HTLV-1 seropositivity in children was associated with elevated maternal anti HTLV-1 antibody titer, high maternal HTLV-1 proviral load and child's gender, girls being more frequently HTLV-1 infected than boys.

CONCLUSION

HTLV-1 infection, which can be responsible for severe pathologies in adults (adult T cell leukemia and tropical spastic paraparesis/HTLV-1 associated myelopathy) should be screened during pregnancy in women originating from high HTLV-1 endemic areas, as for France, mainly the French West Indies, French Guyana and Intertropical Africa. In case of HTLV-1 seropositivity, mothers should be informed on the risk of transmission and promotion of bottle feeding of their children should be strongly proposed.

[Medical termination of pregnancy at 9-14 weeks gestation. Prospective study of 105 cases in Saint-Laurent-du-Maroni (French Guyana)]

OBJECTIVES

To demonstrate the effectiveness and safety of mifepristone 600mg with misoprostol 800 mg, for termination of pregnancy at 9-14 weeks gestation.

PATIENTS AND METHODS

This prospective study included 105 women at 9 to 14 weeks gestation given 800 mg of vaginal misoprostol, 2 or 3 days after a single dose of 600 mg of mifepristone for pregnancy termination. Outcomes measures included mean expulsion time, the interval between fotal and placental expulsion, adverse effects, vaginal bleeding, requirement for analgesia, and hospital stay, analyzed by parity and gestational age.

RESULTS

Pregnancy termination was successful in 92.4% of the patients without requirement for surgery. The mean time to expulsion was 6 hours. The fetus and placenta were expelled together in 79% of the cases. In 15% the conception products were retained in the cervical canal, and removed with a ring forceps. Additional misoprostol doses were necessary in 33% and analgesia (nalbuphine sublingually, mean dose was 10mg) in 56%. Significant bleeding was observed in 7.5%, leading to curettage in 2 patients. No statistically significant differences were found between the rate of success and term (9-12 versus 12-14) or parity.

CONCLUSION

Combining oral mifepristone and vaginal misoprostol is a successful alternative to surgical termination of pregnancy, even after 9 weeks' gestation. The use of nalbuphine for analgesia improves acceptability; sublingual administration helps avoid invasive procedures. Before 14 weeks gestation, the legal limit for termination of pregnancy in France, the choice between the surgical and medical alternatives should be left to the patient.

[Paraquat poisoning at the beginning of pregnancy]

Case report of a paraquat poisoning at the beginning of pregnancy (10 weeks) with mother and child survey. The baby was exempt of abnormalities and of normal weight. He was followed up to the age of 4 and did well clinically. These data are associated with a review of the literature.

Consequences of reduced umbilical and increased foetal cerebral flow during malaria crisis on foetal behaviour

The objectives of this study were (a) to evaluate the sensitivity and specificity of foetal Doppler indices for the prediction of abnormal foetal heart rate (aFHR) at delivery after malaria crisis and (b) to test Doppler parameters against crisis duration for predicting aFHR. Every day during the malaria crisis, the umbilical and cerebral vascular resistance indices were measured by Doppler. These indices allowed evaluation of the amplitude of the foetal flow redistribution induced by malaria (C/U=cerebral resistance/umbilical resistance ratio), the duration of the flow redistribution period and the hypoxic index (mean %C/U change x crisis duration). It was found that the mean duration of the flow redistribution period was: 7 +/- 2 days, mean C/U change -7% +/- 4, hypoxic index -56 +/- 37, prematures 35%, and aFHR 17%. An hypoxic index > 150 predicted occurrence of aFHR with high sensitivity and specificity (100%/91%). The highest foetal flow disturbance (max %C/U) and the duration of the period with flow disturbance (> 7 days) predicted aFHR at delivery with a sensitivity of 10% and 40% and a specificity of 77% and 78%. It was concluded that the hypoxic index was more predictive of aFHR at delivery than the amplitude or the duration (i.e. crisis duration) of the foetal flow redistribution.

[Perinatal care and mortality in French Guyana. From 1992-1999]

BACKGROUND

The purpose of this study was to describe child deliveries in French Guyana and describe changes in perinatal mortality in different population groups between 1992 and 1999.

MATERIAL AND METHODS

All deliveries in health centers and maternity wards in French Guyana between January 1, 1992 and December 31, 1999 were included in the study. Social, demographic, and clinical data were collected at the time of delivery. Infants with a birth weight of 500 g or term 22 weeks were included.

RESULTS

From 1992 to 1995, the number of deliveries in health centers declined 5.7% and the number in public maternity wards increased 69.7%. The same trend was observed in 1998 - 1999 (2.4% and 85.7% respectively), an expression of the policy of antenatal referral implemented by the network of childbirth professionals. Perinatal mortality decreased significantly between 1995 and 1998 from 35.4 to 15.2 for the Creole population (p=0.06), from 46 to 16.5 for the Black-Marron Surinam population (p<0.0007), and from 36 to 10.2 for the Black-Marron French population (p<0.009). This drop in mortality in high-risk population groups may have contributed to the overall decline in perinatal mortality observed over the study period. The rate of preterm birth remained stable (at 13.5%) and the proportion of low-weight infants increased only slightly (12.8% to 13.7%). Mortality among preterm infants declined considerably, undoubtedly because of improved neonatal intensive care.

CONCLUSION

Despite significant improvement, the perinatal mortality in French Guyana (18.9 in 1999) remains almost three times that in metropolitan France (7.4 in 1999). The mothers are young (17% aged less than 20 years) and the proportion of primiparous and grand multiparous mothers is high. With the absence or insufficiency of prenatal care, the problem of perinatal mortality remains a public health priority and challenge in French Guyana.

[Medico-economic study of percutaneous and surgical closure of ostium secundum type interatrial communications]

The aim of this study was the medico-economic evaluation of the closure of ostium secundum type interatrial communications in 32 patients, treated by cardiac catheterisation (group A: n = 17) or by surgery (group B: n = 15). The success rate was 100% with the 2 techniques. With national cost scale data we evaluated the overall cost of the 2 treatments using the information system medical program, starting from homogenous groups of patients: 150 catheterisation, 169 and 170 surgery. As the value for the homogenous group of 150 patients was much lower than the price of the material used for catheterisation, an adjusted group of 150 patients including the price of this material was created. An evaluation in terms of an artificial index of activity was also performed. The average duration of hospital stay for group A was reduced by 6.1 days compared to group B (p < 0.001). The overall cost was lower in group A than in group B (p < 0.001), using the real and "adjusted" homogenous group of 150 patients, with a respective reduction of 7,582 Euros and 3,731 Euros. Surgery and catheterisation scored 8,167 points (17,756 Euros) and 2,726 points (5,926 Euros) per patient respectively on the artificial activity index. In conclusion, catheterisation reduced the duration of hospital stay and brought an economic benefit for the Assurance Maladie compared to surgery. However, surgery is more profitable for the hospital than catheterisation because of the high cost of the prosthesis, which is not taken into account with a homogenous group of non-specific patients. This could hamper the development of this innovative technique in a hospital subjected to overall budgetary constraints.

[Trial vacuum extractor for cephalic engagement. 50 cases in French Guiana]

OBJECTIVE

Considering a population with an African culture traditionally opposed to a caesarean section, vertex engagement with a vacuum extractor could be a good alternative.

PATIENTS AND METHODS

In a retrospective study of 50 cases of trial engagement with a vacuum extractor in French Guyana, there were 94% of vaginal deliveries.

RESULTS

A high level of shoulder dystocia (14%) was noted, and the failure of this technique was the consequence of disproportions between foetus and pelvis that had not been correctly diagnosed.

CONCLUSION

In this article, feasibility and obstetrical conditions to carry out a trial engagement with a vacuum extractor are discussed.

Tubulin is an inherent component of mitochondrial membranes that interacts with the voltage-dependent anion channel

We have previously reported that anti-tubulin agents induce the release of cytochrome c from isolated mitochondria. In this study, we show that tubulin is present in mitochondria isolated from different human cancerous and non-cancerous cell lines. The absence of polymerized microtubules and cytosolic proteins was checked to ensure that this tubulin is an inherent component of the mitochondria. In addition, a salt wash did not release the tubulin from the mitochondria. By using electron microscopy, we then showed that tubulin is localized in the mitochondrial membranes. As compared with cellular tubulin, mitochondrial tubulin is enriched in acetylated and tyrosinated alpha-tubulin and is also enriched in the class III beta-tubulin isotype but contains very little of the class IV beta-tubulin isotype. The mitochondrial tubulin is likely to be organized in alpha/beta dimers and represents 2.2 +/- 0.5% of total cellular tubulin. Lastly, we showed by immunoprecipitation experiments that the mitochondrial tubulin is specifically associated with the voltage-dependent anion channel, the main component of the permeability transition pore. Thus, tubulin is an inherent component of mitochondrial membranes, and it could play a role in apoptosis via interaction with the permeability transition pore.

[Typhoid fever and pregnancy]

Typhoid fever is rare in Europe, but well-recognized endemic disease in tropical zones. We report our findings in a series of 25 cases of typhoid fever during pregnancy observed in French Guiana and reviewed the literature on clinical signs, diagnosis and treatment. Salmonellea typhi causes septicemia of digestive origin that can cross the placenta resulting in chorioamniotitis. Maternal-fetal infection with S. typhi can lead to miscarriage, fetal death, neonatal infection, as well as diverse maternal complications. In order to avoid maternal complications and possible fetal transmission, treatment with ceftriaxone should be initiated as early as possible

Involvement of microtubules and mitochondria in the antagonism of arsenic trioxide on paclitaxel-induced apoptosis

Arsenic trioxide (As(2)O(3)) at low concentrations (1-10 microM) is effective in the treatment of acute promyelocytic leukemia (APL) and lymphoma and is in clinical trials for treatment of solid tumors. Paclitaxel, an antimicrotubule agent, is highly efficacious in the treatment of adult tumors and is in clinical evaluation in childhood tumors. This study is the first to investigate the combination of arsenic and paclitaxel in the range of clinically achievable concentrations. We found that the simultaneous combination was antagonistic on proliferation of the neuroblastoma SK-N-SH cell line by using the combination index (CI) method. Moreover, a 40+/-5% decrease in paclitaxel-induced apoptosis in cells co-treated with As(2)O(3) confirmed the antagonism. The mechanism of antagonism was studied at the cellular level with 200 nM paclitaxel, twice the IC(50) value, and with 1 microM As(2)O(3) which administered singly did not affect cell survival or the microtubule network. As(2)O(3) antagonized the effects of paclitaxel on tubulin and microtubules. Paclitaxel-induced mitotic block was decreased by 20+/-2% and bundles induced by 200 nM paclitaxel were less condensed in the presence of 1 microM As(2)O(3). As(2)O(3) (10-200 microM) induced a concentration-dependent inhibition of tubulin polymerization in vitro which was maintained in presence of paclitaxel. Spectrophotometric and spectrofluorometric measurements indicated an interaction of As(2)O(3) with tubulin SH groups, without modification of the stoichiometry of paclitaxel binding to tubulin. Moreover, 4 microM As(2)O(3) inhibited the release of cytochrome c from isolated mitochondria by 78+/-10%. Our results show that As(2)O(3) and paclitaxel act antagonistically on mitochondria and microtubules and illustrate the need for careful evaluation of drug combinations.

Hyperphosphorylation of tau is mediated by ERK activation during anticancer drug-induced apoptosis in neuroblastoma cells

Phosphorylated tau protein is the major component of paired helical filaments in Alzheimer disease (AD). We have previously shown that abnormal tau phosphorylation was induced in neuroblastoma SK-N-SH cells by the anticancer drug, paclitaxel, during apoptosis [Guise et al., 1999: Apoptosis 4:47-58]. In the present study, we first demonstrated a shift from fetal tau to hyperphosphorylated tau after incubation with paclitaxel, that showed some similarities with the hyperphosphorylated tau in AD, by using several tau antibodies, N-Term, Tau-1 and AT-8. Tau phosphorylation occurred independently of caspase-3 activation. We next showed that a sustained activation of ERK (extracellular signal-regulated kinase) induced both tau phosphorylation and apoptosis during paclitaxel treatment (1 microM). The inhibition of ERK activation by using the pharmacological MEK1/2 inhibitor, PD98059 (50 microM), or an antisense strategy, reduced tau phosphorylation and neuronal apoptosis (P < 0.001), indicating a link between ERK activation, tau phosphorylation and apoptosis. Doxorubicin (0.2 microM), an anticancer drug whose mechanism of action is independent of microtubules, also induced ERK activation, tau phosphorylation and apoptosis. Moreover, doxorubicin induced some morphological features of neurodegeneration such as loss of neurites and disorganization of the cytoskeleton in apoptotic neuroblastoma cells. Altogether, our results suggest that tau phosphorylation plays a significant role in apoptosis enhancing disruption of microtubules that in turn leads to formation of apoptotic bodies, suggesting that neurodegeneration and apoptosis are related.

[Dengue fever and pregnancy. A study of 38 cases in french Guiana]

OBJECTIVES

Evaluation of the consequences of a dengue fever infection on mother and foetus during pregnancy.

PATIENTS AND METHODS

Between February 1, 1992 and December 31, 1999, 172 patients with non malaria hyperthermia were tested for dengue fever infection at the maternity of the Saint-Laurent-du-Maroni hospital in French Guyana. The diagnosis was considered positive when specific IgM was present and/or with virus isolation or viral ARN detection using RT-PCR. Among the 38 cases of mothers infected by dengue fever throughout the three trimesters of pregnancy, it was possible to take 19 fetal blood samples.

RESULTS

The major consequences for the mothers were risk of premature delivery in 55% of the cases, one case of severe hemorrhagic complications during a cesarean section, and one case of abruptio placentae. The consequences for the fetus were premature birth in 22% of the cases, 5 in utero fetal deaths, 4 cases of acute fetal distress during labor and 2 cases of mother-to-child transmission.

CONCLUSION

In case of dengue fever infection of the mother during pregnancy, there is a serious risk of premature birth and fetal death. In case of infection close to term, there is a risk of hemorrhage for both the mother and the newborn.

Caspase-8 activation independent of CD95/CD95-L interaction during paclitaxel-induced apoptosis in human colon cancer cells (HT29-D4)

Antimicrotubule agent-induced apoptosis was examined in the proliferating human colon cancer cell line HT29-D4. G2/M arrest and subsequent apoptosis were dose-dependent, both observed with 100 nM paclitaxel or docetaxel and 10 nM vinorelbine. Bcl-x(L) phosphorylation was observed simultaneously with mitotic block, then caspase-3 cleavage and poly(ADP-ribose) polymerase degradation were detected 48 hr later. By using both enzymatic assay and immunoblot detection of cleaved fragments, we showed that caspase-8, a central component of the CD95-induced apoptotic pathway, was significantly activated during paclitaxel exposure, contemporary to apoptosis occurrence. Caspase-8 activation and apoptosis were independent of CD95 ligation and evidenced only for concentrations inducing Bcl-x(L) phosphorylation and a decrease in mitochondria permeability. Similar results were obtained with docetaxel and vinca alkaloids. Thus, antimitotic drugs may induce apoptosis via caspase-8 activation independently of CD95/CD95-L. Caspase-8 may be a common mediator of anticancer drug-induced apoptosis that could represent a promising target for future therapies.

Decrease of human T-cell lymphotropic virus type I prevalence and low incidence among pregnant women from a high endemic ethnic group in French Guiana

To assess the prevalence and incidence of human T-cell lymphotropic virus type I (HTLV-I), 4,234 pregnant women of different ethnic origins were tested before each delivery between 1991 and 1997 in a high HTLV-I endemic area of French Guiana. HTLV-I was significantly more prevalent among ethnic groups of African descent as the Noir-Marrons (4.8%, 95% confidence interval [CI]: 4.0-5.6) and Haitians (5%, 95% CI 1.6-8.4). An age dependence of HTLV-I seroprevalence was observed. The mean age of Noir-Marron HTLV-I seronegative women was lower than for HTLV-I seropositive women (24. 7 vs. 28.6, p < 0.001). A decline in HTLV-I seroprevalence was observed, particularly in the Noir-Marron younger than 21 years old (p = 0.04). For five HTLV-I seroconversions observed, the incidence per 100 women-years in the Noir-Marron group was 0.19 (95% CI 0.02-0. 35) for all women, 0.32 in those 25 years old or younger (95% CI 0-0. 64), and 0.07 in those older than 25 years (95% CI 0-0.2). This observation was inconsistent with HTLV-I seroprevalence observed for those 25 years old or younger (2.8%) and those older than 25 (8.3%). These data demonstrate, for the first time outside Japan, a birth cohort effect for HTLV-I in a highly endemic ethnic group.

Mother-to-child transmission of human T-cell-leukemia/lymphoma virus type I: implication of high antiviral antibody titer and high proviral load in carrier mothers

In order to gain new insights into the risk factors influencing human-T-cell-leukemia/lymphoma-virus-type-I (HTLV-I) mother-to-child transmission, a retrospective study of HTLV-I infection among children born to HTLV-I-seropositive women was carried out in a highly HTLV-I-endemic population of African origin living in French Guyana. The study covered 81 HTLV-I-seropositive mothers and their 216 children aged between 18 months old and 12 years old. All plasma samples were tested for the presence of HTLV-I antibodies by ELISA, immunofluorescence assay and Western blot. HTLV-I provirus was detected, in the DNA extracted from peripheral-blood mononuclear cells, by polymerase chain reaction (PCR) using primers specific for 3 different HTLV-I genomic regions (LTR, gag and pX) and quantified by a competitive PCR assay. Out of the 216 children, 21 were found to be HTLV-I-seropositive, giving a crude HTLV-I transmission rate of 9.7%, while among the 180 breast-fed children 10.6% were HTLV-I-seropositive. Perfect concordance between serological and PCR results was observed, and none of the 195 HTLV-I-negative children was found HTLV-I-positive by PCR. In conditional (by family) logistic-regression models, HTLV-I seropositivity in children was associated with an elevated maternal anti-HTLV-I-antibody titer (OR 2.2, p = 0.0013), a high maternal HTLV-I proviral load (OR 2.6, p = 0.033) and child's gender, girls being more frequently HTLV-I-infected than boys: OR 3.6, p = 0.0077 in the model including maternal anti-HTLV-I-antibody titer and OR 4.1, p = 0.002 in the model including the maternal HTLV-I proviral load.

Mother-to-child transmission of human T-cell-leukemia/lymphoma virus type I: implication of high antiviral antibody titer and high proviral load in carrier mothers

In order to gain new insights into the risk factors influencing human-T-cell-leukemia/lymphoma-virus-type-I (HTLV-I) mother-to-child transmission, a retrospective study of HTLV-I infection among children born to HTLV-I-seropositive women was carried out in a highly HTLV-I-endemic population of African origin living in French Guyana. The study covered 81 HTLV-I-seropositive mothers and their 216 children aged between 18 months old and 12 years old. All plasma samples were tested for the presence of HTLV-I antibodies by ELISA, immunofluorescence assay and Western blot. HTLV-I provirus was detected, in the DNA extracted from peripheral-blood mononuclear cells, by polymerase chain reaction (PCR) using primers specific for 3 different HTLV-I genomic regions (LTR, gag and pX) and quantified by a competitive PCR assay. Out of the 216 children, 21 were found to be HTLV-I-seropositive, giving a crude HTLV-I transmission rate of 9.7%, while among the 180 breast-fed children 10.6% were HTLV-I-seropositive. Perfect concordance between serological and PCR results was observed, and none of the 195 HTLV-I-negative children was found HTLV-I-positive by PCR. In conditional (by family) logistic-regression models, HTLV-I seropositivity in children was associated with an elevated maternal anti-HTLV-I-antibody titer (OR 2.2, p = 0.0013), a high maternal HTLV-I proviral load (OR 2.6, p = 0.033) and child's gender, girls being more frequently HTLV-I-infected than boys: OR 3.6, p = 0.0077 in the model including maternal anti-HTLV-I-antibody titer and OR 4.1, p = 0.002 in the model including the maternal HTLV-I proviral load.

Mother-to-child transmission of human T-cell-leukemia/lymphoma virus type I: implication of high antiviral antibody titer and high proviral load in carrier mothers

In order to gain new insights into the risk factors influencing human-T-cell-leukemia/lymphoma-virus-type-I (HTLV-I) mother-to-child transmission, a retrospective study of HTLV-I infection among children born to HTLV-I-seropositive women was carried out in a highly HTLV-I-endemic population of African origin living in French Guyana. The study covered 81 HTLV-I-seropositive mothers and their 216 children aged between 18 months old and 12 years old. All plasma samples were tested for the presence of HTLV-I antibodies by ELISA, immunofluorescence assay and Western blot. HTLV-I provirus was detected, in the DNA extracted from peripheral-blood mononuclear cells, by polymerase chain reaction (PCR) using primers specific for 3 different HTLV-I genomic regions (LTR, gag and pX) and quantified by a competitive PCR assay. Out of the 216 children, 21 were found to be HTLV-I-seropositive, giving a crude HTLV-I transmission rate of 9.7%, while among the 180 breast-fed children 10.6% were HTLV-I-seropositive. Perfect concordance between serological and PCR results was observed, and none of the 195 HTLV-I-negative children was found HTLV-I-positive by PCR. In conditional (by family) logistic-regression models, HTLV-I seropositivity in children was associated with an elevated maternal anti-HTLV-I-antibody titer (OR 2.2, p = 0.0013), a high maternal HTLV-I proviral load (OR 2.6, p = 0.033) and child's gender, girls being more frequently HTLV-I-infected than boys: OR 3.6, p = 0.0077 in the model including maternal anti-HTLV-I-antibody titer and OR 4.1, p = 0.002 in the model including the maternal HTLV-I proviral load.

Differentiation of human colon cancer cells changes the expression of beta-tubulin isotypes and MAPs

The human colon adenocarcinoma HT29-D4 cell line is an interesting model for studies on epithelial cell differentiation. Undifferentiated cells are malignant proliferating cells, whereas differentiated cells act like epithelial polarized cells. In the present study, we first characterized the action of taxoids on the microtubular network of HT29-D4 cells according to the state of differentiation. Microtubular bundles were found in undifferentiated cells but not in differentiated cells, even with 500-fold higher taxoid concentrations for 96 h. This finding led us to study changes in microtubules according to the polarity status of the cell. E-MAP-115 was expressed only in differentiated cells; expression of beta-tubulin isotypes was altered in them relative to undifferentiated cells. Classes I, II, III, IVa and IVb isotypes were expressed in both phenotypes; however, differentiated epithelial cells displayed a specific increase in class III beta-tubulin. Thus, the increase in expression of this beta-tubulin isotype in differentiated cells is not restricted to neuronal cells. Moreover, these expression changes may reflect a higher stability of microtubular network in differentiated cells, which may explain the lower activity of anti-microtubule agents, independently of the mitotic process. These results indicate that the composition of microtubules should be considered as one of the criteria involved in the response of tumour cells to chemotherapy with anti-microtubule agents.