Seroepidemiological survey of HTLV-I infection in French Polynesia, Cook Islands and Fiji

Different population groups of French Polynesia, Cook Islands and Fiji were screened for Human T-Lymphotropic Virus type I (HTLV-I) antibodies. Among 1487 individuals sampled in French Polynesia, twelve were considered Western Blot (WB) indeterminate and one was considered WB-positive for HTLV-I infection. This positive subject originated from France and was a blood donor. Out of 196 Polynesians of the Cook Islands, one was WB-indeterminate. Among populations sampled in Fiji, one of 222 Melanesians was found WB-indeterminate and one of 211 Indians was WB-indeterminate.

Proliferation of microglia/macrophages in the demyelinating CNS and PNS of twitcher mouse

In demyelinating lesions in the central and peripheral nervous systems of twitcher mouse, a murine model of globoid cell leukodystrophy, marked increases of [3H]thymidine-labeled elements including Mac-1 immunopositive (Mac-1+) microglia/macrophages was observed. Their proliferative activities were already pronounced at the postnatal day (P) 20, an early stage of demyelination, peaked at P30 and then declined at P45, at the terminal stage of the disease. Many of the [3H]thymidine-labeled Mac-1+ cells had morphological features of ramified microglia. Macrophage-like Mac-1+ cells were less frequently labeled. The results of this study showed that (1) microglia/macrophages proliferated in the genetic demyelinating lesions, (2) many dividing Mac-1+ cells had the shape of ramified microglia and (3) the rate of proliferation declined in later stages when reactive microglia/macrophages were abundant in the lesions. The temporal events of this study suggest that signal(s) from the degenerating myelin or myelin-forming cells stimulate(s) cellular proliferation and that ramified microglia were one of the principal-dividing elements in the lesion. The biological mechanisms underlying the decline of the proliferative activity of microglia require further studies.

Long-term experience with sumatriptan in the treatment of migraine

Sumatriptan, a specific 5-hydroxytryptamine agonist, is a novel acute treatment for migraine. The efficacy and safety profiles of sumatriptan have previously been demonstrated in several controlled short-term studies. However, because migraine is a recurrent disorder which may persist throughout adult life, sustained efficacy and tolerability are essential if sumatriptan is to be of value in clinical practice. These aspects were therefore evaluated in a programme of three 12-month studies. Sustained efficacy with long-term use of single 100-mg oral doses has been demonstrated in an open study in which 288 patients treated 8,094 migraine attacks. The long-term safety profile of oral and subcutaneous sumatriptan has been evaluated in a total of 849 patients who treated 24,907 migraine attacks in studies lasting up to 1 year. Sumatriptan was well tolerated. Adverse events did not differ qualitatively or quantitatively from those in short-term studies, irrespective of the frequency of attacks or the number of doses used. Migraine attacks were effectively treated with doses less than the recommended maximum and there was no evidence of any adverse effect on attack frequency. In long-term studies the high efficacy of sumatriptan is maintained, and the adverse event profile is unchanged and unaffected by attack frequency.

Mode of EGF action on cell cycle kinetics in human breast cancer cell line MCF-7: some evidence that EGF acts as a "progression factor"

EGF is known to play a very important role in the growth regulation of tumor cells. We have determined the effect of EGF in the absence and in the presence of serum on the cell cycle of MCF-7 cells synchronized in the G1 phase by serum deprivation. In the presence of 1% serum, EGF was found to increase DNA synthesis to 120% of control (P < 0.02), but did not modify the transition time from G1 into S phases, nor the cell doubling time during the first generation following the cell synchronization. The autoradiography analysis of 3H-thymidine labeled cells indicated that, following 24 h of EGF treatment, a constant additional number of cells (11 +/- 1.5%, P < 0.002) were recruited into the S phase in the presence as well as in the absence of serum. These data indicate that EGF exerts its mitogenic effect on MCF-7 cells by increasing the percent of S phase cells without modulating the cell doubling time. However, in the absence of serum a significant increase of thymidine incorporation in whole cells required 12 h of EGF treatment, whereas a 6 h-incubation with EGF was sufficient to stimulate DNA synthesis when synchronized cells were pretreated with serum for 6 h, suggesting that EGF sensitivity is dependent on the cell advance into the G1 phase at the moment of EGF addition. Topographical analysis of 3H-thymidine-labeled cells aimed at determining the spatial distribution of cells in culture revealed that EGF-stimulated cells were disposed near proliferative cells, indicating the local influence on cell proliferation. Taken together, our results suggest that in the MCF-7 cell line, EGF acts in the G1 phase by increasing the proportion of S cells without affecting the duration of the cell cycle. In our model, EGF seems to act as a "progression factor", in that it stimulates only cells already traversing a certain stage in the G1 phase under the action of serum factors, cell secreted diffusible products and cell-cell contact.

A simple vacuum transfer device for nucleic acids

We present a new vacuum device intended for transferring nucleic acids from agarose gels onto hybridization membranes. The apparatus is drawn so that plastic sheets serve as substitutes for the elaborate, but cumbersome and unnecessary, locking systems mounted on all the commercial blotters. This substitution results in (1) a much more easy and rapid set-up of the transfer and (2) a very simple framework allowing the possibility of low-cost manufacturing.

Mass chemoprophylaxis of lymphatic filariasis with a single dose of ivermectin in a Polynesian community with a high Wuchereria bancrofti infection rate

In April 1991 supervised mass prophylaxis of lymphatic filariasis with a single dose of ivermectin, 100 micrograms/kg, was carried out in a Polynesian village with a high infection rate of Wuchereria bancrofti in humans and active transmission by the vector mosquito, Aedes polynesiensis. Of 876 inhabitants aged 3 years or more (pregnant women excluded), 864 (98.6%) were treated. Simultaneously, venous blood samples were collected from 577 (97.5%) of the 595 inhabitants aged 15 years or more, of whom 122 (21.4%) were found to be microfilaria (mf) carriers (86 males and 36 females). The geometric mean microfilariae (GMM) count was 358.7 mf/ml for the whole group, 387 mf/ml for males (range 1-8160 mf/ml) and 280 mf/ml for females (range 1-7769 mf/ml). Following treatment, 33 (3.8%) of the 864 persons treated experienced some adverse reactions (21 with grade 1 and 12 with grade 2). Of the 33 with reactions, 29 were among the 122 (23.8%) mf carriers and 4 among the 831 (0.5%) non-microfilaraemic persons. Six months later, 123 (21.1%) of 584 inhabitants sampled were microfilaraemic: the GMM count for the whole group was 106 mf/ml (1-8177), with 29 mf/ml (1-3740) in 35 female and 177 mf/ml (1-8177) in 88 male carriers. Of these 123, 15 (whose GMM count was 4.5 mf/ml; range 1-204) were amicrofilaraemic 6 months before, and 19 had a microfilaraemia level higher than that 6 months earlier, before treatment. 117 of the 122 carriers identified in April were resampled: comparison of their GMM counts before and 6 months after mass treatment indicated that treatment with a single dose of 100 micrograms/kg ivermectin resulted in a reduction of microfilaraemia by 69%.

Effects of culture passages on collagen immunostaining in human dental pulp and gingival fibroblasts

In this study, a scanning microscopic computer-assisted image analysis system was used for the immunocytochemical characterisation of collagen types I, III and V in normal human fibroblasts from pulp and gingival explants, using specific purified antibodies and peroxidase labeling. The culture conditions were standardized in order to evaluate simultaneously the expression of the three antigens in four different culture passages of the two fibroblast types. The optical density values of immunostaining intensities were quantified, the integrated optical density per cell was calculated, and the results were analyzed by a variance test. It was found that all three collagen types were present in the tissues, and in both gingival and pulp fibroblasts after three to nine culture passages. A non-parametric statistical analysis of the staining intensity variances revealed significant differences between antigenic levels depending on the tissue origin of the fibroblasts and an effect of culture passages. The results seemed to justify application of this technique at the light microscope level for the evaluation of collagen production, the principal function of fibroblasts, but the tissue origin and number of culture passages should be taken into consideration for in vitro biocompatibility testing of dental materials.

Leprosy in French Polynesia. The possible impact of multidrug therapy on epidemiological trends

In 1982, following the recommendations of a WHO study group, multidrug therapy (MDT) was introduced into French Polynesia to treat all patients suffering from active leprosy, and--only on request--those still on dapsone monotherapy. After 5 years, a clear-cut decrease of prevalence and mean annual detection rates for leprosy (except for detection rates among children aged less than 15 years, many of such cases being detected early by increased household contact training) has been observed. There was also a decrease in the proportion of newly detected cases with disabilities. During the 21-year period preceding the introduction of MDT into the control programme, mean annual detection rates for leprosy had remained stable, and this led to the consideration that such a decrease was due neither to the natural decline of the disease nor to the economic improvement of the country. Our results, together with the fact that, to date, the relapse rate was nil in the Polynesian patients put on MDT, strongly suggest that the implementation of MDT has resulted in a decrease of detection rates for leprosy which may be a consequence of a decrease in the transmission of the disease.

S phase, an evolutionary chromatin condensation state from G1 to G2, in a breast epithelial cell line

In order to better understand the changes in DNA organization during the cell cycle, we quantified the chromatin texture of breast epithelial cells and followed its evolution through a cell cycle. The diversity of quiescent cell states led us to limit this study to proliferating cell phases, and to choose a cell line with no G0 cells, the MDA AG cell line. We recently developed a methodology for characterizing in situ the cell cycle of breast epithelial cell lines using a cell image processor. This method is based on 15 densitometric and texture parameters computed on individual Feulgen-stained nuclei and on multiparametric analysis of the resulting data. Chromatin pattern assessment is based on nine texture parameters measured from grey-level co-occurrence and run-length section matrices. In the present study, texture parameter computation showed gradual and progressive modifications of nuclear texture. While discrimination of G1, G2 and M phases was possible, we could not discriminate G1 from S and S from G2. The chromatin pattern (defined by these nine parameters) in the G1 and early S phases, on the one hand, and in the late S and G2 phases, on the other hand, were similar. The parameter values of cells in the S phase progressively increased from G1 to G2. Two interphase chromatin condensation states were distinguished in these breast cells: a base state characteristic of a prereplicative stage and a very granular state characteristic of a postreplicative stage. We hypothesized that S cells are a blend of these two states, the evolution of a non-duplicated state toward a duplicated one.

Multiparametric prognostic evaluation of biological factors in primary breast cancer

BACKGROUND

An array of biological features related to tumor cell differentiation status, growth rate, and invasive potential have been identified as potential prognostic factors in breast cancer. We were interested in determining their relative importance in predicting patient survival.

PURPOSE

We evaluated the relative weight of the following four biological factors in predicting survival of patients with breast cancer: tumor cell DNA content (determined by flow cytometry), tumor cell proliferation rate (determined by thymidine kinase activity), expression levels of cathepsin D and urokinase plasminogen activator, and several "classical" clinical and histological factors.

METHODS

Selected from a prospectively updated database, the study population consisted of 319 primary breast cancer patients who received treatment and follow-up care (median, 6 years) in the Centre René Huguenin. To determine the profile of biological factors for each patient, we used frozen tumor specimens and (except for the flow cytometric DNA content assay) commercially available assay kits. We determined by Cox multivariate analysis the relationships of the biological factors to each other, to classical prognostic factors, and to disease-free and metastasis-free survival.

RESULTS

In the overall population, disease-free survival was best predicted by node status (P = .004), clinical tumor size (P = .02), and cathepsin D expression (P = .01), whereas metastasis-free survival was best predicted by node status (P = .0004), clinical tumor size (P = .009), and urokinase plasminogen activator expression (P = .04). In node-negative patients, thymidine kinase activity was the only factor selected for disease-free (P = .04) and metastasis-free (P = .05) survival. In node-positive patients, the number of positive axillary lymph nodes was the only factor selected for disease-free (P = .0008) and metastasis-free (P = .00017) survival.

CONCLUSIONS

Our retrospective analysis has identified protease expression and tumor cell proliferation rate as important biological prognostic factors in breast cancer. Prospective clinical trials should be undertaken to confirm these results.

Wuchereria bancrofti infection in human and mosquito populations of a Polynesian village ten years after interruption of mass chemoprophylaxis with diethylcarbamazine

In 1991, a study on Wuchereria bancrofti microfilariae (mf) and infection rates was carried out in the human and mosquito populations of a Polynesian village where, 10 years before, the mf prevalence rate was 6.4% and twice-yearly mass treatment with 3 mg/kg of diethylcarbamazine (DEC) was interrupted. Venous blood samples were collected from 575 (97%) individuals aged 15 years or more, of whom 122 (21.4%) were mf positive. The mf carrier prevalence rate was 27.4% in males, significantly higher than that of 14% in females; it increased from 7-12% in the youngest age group (15-19 years) to 40-50% in the oldest (> or = 60 years) for both males and females. 387 mosquito collections were performed and 1748 female Aedes polynesiensis were dissected, of which 1176 were parous. Among the latter, 114 (9.7%) were infected with Wuchereria bancrofti larvae at L1, L2 or L3 stages. The mean number of larvae per mosquito was 2.46 (range 1-15). Of the 114 infected mosquitoes, 30 harboured L3 larvae, giving a 2.55% infective rate; the mean number of L3 larvae per mosquito was 1.15 (range 1-2). Such findings indicate that the interruption of systematic twice-yearly mass treatment with DEC (3 mg/kg) has resulted, after 10 years, in a substantial increase of microfilarial prevalence in humans, and in high infection rates in mosquitoes.

Compared efficacy of repeated annual and semi-annual doses of ivermectin and diethylcarbamazine for prevention of Wuchereria bancrofti filariasis in French Polynesia. Final evaluation

In October 1989, 58 apparently healthy Polynesian Wuchereria bancrofti carriers, in whom microfilarial (mf) density was greater than or equal to 100 mf/ml, were randomly allocated to treatment groups receiving single doses of either ivermectin at 100 mcg/kg or diethylcarbamazine (DEC) at 3 and 6 mg/kg. Six months later, half of the carriers initially treated with ivermectin 100 mcg/kg or DEC 3 mg/kg were given a second similar dose while the rest were given a placebo. Six months later again, all of the carriers received a last treatment dose similar to the initial one. The results observed during the 12-month period which followed this last treatment have confirmed that (i) in terms of immediate clearance or complete negativation of microfilaremia, the efficacy of ivermectin is higher than that of DEC (at dosage of 3 or 6 mg/kg), (ii) DEC is more effective than ivermectin in sustaining the reduction of microfilaremia over a longer period of time and (iii) the efficacy of repeated single doses of either DEC 3 mg/kg or ivermectin 100 mcg/kg is much higher when given semi-annually than annually.(ABSTRACT TRUNCATED AT 250 WORDS)

IgA immunoassay for the diagnosis of bancroftian filariasis

In some parasitic infection such as toxoplasmosis, specific IgA is a highly reliable marker of active infection. In bancroftian filariasis, only 10 of 20 (50%) and 3 of 20 (15%) of the microfilaremic patients were positive for IgA anti-Brugia malayi using respectively indirect ELISA and immunocapture ELISA tests. As regard to these low sensitivities, the detection of specific IgA is unlikely to be a useful test for the diagnosis of active Wuchereria bancrofti infection.

[Ivermectin or diethylcarbamazine in spaced dosages in Bancroft's filariasis: which protocol?]

58 apparently healthy Polynesian Wuchereria bancrofti carriers were randomly allocated to 5 treatment groups: 1) two annual doses of ivermectin 100 mcg/kg, 2) three semi-annual doses of ivermectin 100 mcg/kg, 3) two annual doses of diethylcarbamazine (DEC) 3 mg/kg, 4) semi-annual doses of DEC 3 mg/kg, 5) two annual doses of DEC 6 mg/kg. Results observed during the 12-month period which followed last treatment have confirmed that efficacy of ivermectin is higher than that of DEC in terms of immediate clearance or complete negativation of microfilaremia, but not in terms of sustained reduction and that efficacy of repeated single doses of either DEC 3 mg/kg or ivermectin 100 mcg/kg is much higher when given semi-annually than annually. They also have indicated that (i) 6 months after last treatment: 3 semi-annual doses of 100 mcg/kg of ivermectin have resulted in high reduction of microfilaremia (85%) and, 2 annual doses of 6 mg/kg and 3 semi-annual doses of 3 mg/kg of DEC have resulted in even greater reduction (96 and 98% respectively) and (ii): 12 months after last treatment, the greatest reductions of microfilaremia (95 and 92%) have been observed in carriers treated, respectively, with 3 semi-annual doses of 3 mg/kg or with 2 annual doses of 6 mg/kg of DEC.(ABSTRACT TRUNCATED AT 250 WORDS)

cDNA cloning and genomic analysis of a new multigene family sharing common phylogenetic and expression profiles with the laminin receptor gene

We have isolated a human laminin receptor (LR) cDNA which bears a different sequence in its 5' end with regard to the corresponding region in the regular LR mRNA. This different sequence hybridizes to a 1 kb mRNA. We have cloned a 740 bp cDNA for this transcript (cDNA 48-1). Search on sequence data bases revealed no sequence homology with known messengers or proteins. Using cDNA 48-1 in a simplified version of the protocol with which we had previously characterized the LR gene as a member of a retrogene family in mammals, we show in the present paper that the gene of this new transcript exhibits phylogenic, expression and amplification features that strickingly recall those of the LR gene.

Laminin expression by two clones isolated from the colon carcinoma cell line LoVo that differ in metastatic potential and basement-membrane organization

In the present report we describe the characteristics of 2 clones, E2 and C5, isolated from the human colon adenocarcinoma cell line LoVo. When grafted to immunosuppressed newborn rats, these clones formed tumors that varied with regard to differentiation rate, basement-membrane organization and lung metastatic potential. Production and distribution of laminin by E2, C5 and related tumors was studied by immunohistochemistry with an anti-laminin monoclonal antibody 4C12 (MAb 4C12). In lowly metastatic E2-derived tumors, strong regular stainings were observed which were strictly peri-tumoral and corresponded to the basal lamina. Since the antibody interacted with human laminin (the graft) but not with rat laminin (the host), this result indicated that basement-membrane laminin was supplied mainly by tumor-cell synthesis. In highly metastatic C5-derived tumors, the staining obtained with MAb 4C12 was peri-cellular and unorganized. Laminin synthesis by E2 and C5 cells in sub-cultures or soon after dissociation from explanted tumors was studied by metabolic labelling with 35S-methionine under steady-state conditions followed by immunoprecipitation and SDS-PAGE. High-molecular-weight laminin comprised by disulfide-linked A and B chains, i.e., heterotrimeric laminin, was found in cell lysates and in the secretion medium of cell lines and tumor cells. In addition, B1B2 dimers and free B chains were observed in cell lysates. Quantitatively, laminin expression by E2 and C5 clones or tumor cells was not significantly different. These findings suggest that basement-membrane defects in invasive clone LoVo C5 were not due to laminin under-expression.

Association between HIV1 infection and sexually transmitted disease among men in Central Africa

In Africa, heterosexual contact is the major route of transmission of the human immunodeficiency virus (HIV). Previous studies have strongly suggested that other sexually transmitted diseases (STD) may facilitate HIV transmission. However, the association of HIV infection with other STD may simply be a marker of sexual promiscuity. Thus, we compared the association of different STD, HIV status, and sexual behaviour of 160 STD patients and 95 STD-free control individuals. Results showed that STD patients differed from controls in most of the sociological and behavioural parameters, as well as in HIV serological status. Within the STD group, people with genital ulcer disease (GUD) (n = 62) were more likely to be HIV-seropositive (21%) than people with urethritis (n = 98, 11.2%). Meanwhile, there was almost no difference in the sociological and behavioural parameters between the GUD and the urethritis group. Thus, our results reinforce the specific role of mucosal breakage (i.e. genital ulcers) in the transmission of HIV.

Cloning and characterization of a Neisseria gene homologous to hisJ and argT of Escherichia coli and Salmonella typhimurium

We have isolated from a genomic library of the pathogenic Neisseriae gonorrhoeae T2 strain, a gene encoding a putative protein of 268 amino acids which exhibited significant similarity to the hisJ and argT gene products of Salmonella typhimurium and Escherichia coli, periplasmic proteins deputed to amino acid transport within the cell. The gene is transcribed as a monocistronic mRNA species of about 960 nucleotides flanked by regulatory elements for initiation and termination of transcription that are efficiently recognized in an E. coli host.

Heterotrimeric configuration is essential to the adhesive function of laminin

Mouse PFHR9 laminin, B1B2-heterodimers, and free B1-chains were separated from one another by gel filtration on Superose 6. The cell attachment promoting activity of these species was measured after immunoprecipitation with monoclonal anti-laminin antibodies coupled to Sepharose 6MB beads. These antibodies, which did not react with the laminin E8 fragment, were directed against epitopes in the NH2-terminus of the laminin B1-chain and in the central region of laminin. After incubation with purified EHS laminin, the immunosorbents revealed efficient adhesion substrates for a rat rhabdomyosarcoma cell line which attached preferentially to the laminin E8 fragment. Although both were immunoprecipitated efficiently, B1B2-heterodimers and B1-chains, unlike PFHR9 laminin, did not support the attachment of RMS cells. On a molar basis B1B2-heterodimers were 24 times less efficient than PFHR9 laminin or EHS laminin in supporting cell attachment. These data suggest that heterotrimeric configuration is essential to the adhesive function of the laminin E8 fragment.

High levels of anti-Campylobacter-flagellin IgA antibodies in breast milk

Several studies have shown the beneficial role of immunity against enteric Campylobacter sp. Circulating antibodies against flagellin and possibly maternal antibodies seem to protect against intestinal colonization by Campylobacter. Milk from women in Central Africa (n = 120) and in France (n = 31) were investigated for the presence of anti-flagellin antibodies. Results showed that most French and all African milk possessed anti-flagellin IgA but not IgG. The titres of anti-flagellin IgA were elevated in colostrum and decreased in later milk. Specific activities were constant during lactation, suggesting constant antigenic stimulation. The fact that IgA but not IgG are elicited against flagellin could be due to an infection limited to the mucosal surface.