High prevalence of syphilis in women, minors and precarious patients: a cross-sectional study in a Reunion Island sexually transmitted infection clinic, 2017-2020

BACKGROUND

Syphilis is a sexually transmitted infection (STI) with a global prevalence estimated at 0.5% in 2012. Syphilis has been on the rise among men who have sex with men (MSM) in high-income countries and remains at endemic levels in low- and middle-income countries. This trend, however, has not been observed in Reunion Island.

OBJECTIVES

To determine the prevalence, clinical characteristics and risk factors of syphilis in at-risk patients visiting the South Reunion STI clinic in Reunion Island.

METHODS

This monocentric cross-sectional study included all patients who visited our STI clinic between 2017 and 2020. Syphilis serology was performed on all included patients, and data were collected using a standardized self-administered questionnaire.

RESULTS

Over the 3-year study period, 2593 patients were enrolled. The prevalence of syphilis was 7.52% (n = 195, 95% CI, 6.50-8.65%) in the overall study population, 11.76% (n = 18, 95% CI, 6.97-18.59%) in minors (aged under 18 years) and 36.36% (n = 16, 95% CI, 21-59%) in pregnant women. The risk factors identified in multivariate analysis were being female [adjusted Prevalence Ratio (aPR) 1.85, 95% CI, 1.10-3.11], being MSM (aPR 2.87, 95% CI, 1.71-4.80), being aged under 18 years (aPR 3.54, 95% CI, 1.90-6.57), living in precarious conditions [aPR 3.12, 95% CI, 2.11-4.62] and being born in Reunion Island (aPR 2.43, 95% CI, 1.42-4.13). The clinical presentation was heterogeneous (plaques and papules, chancre, atypical ulcerations, multiple ulcerations, condyloma lata, etc.).

CONCLUSIONS

These findings suggest a high prevalence of syphilis in at-risk patients visiting our STI clinic. Unlike the situation in other high-income countries, the people most at risk of syphilis in Reunion Island are local-born residents, minors, women and precarious patients. This is a source of concern, especially given the risk of resurgence of congenital syphilis on the island.

[Prevalence and Risk Factors of Chlamydia Trachomatis Infection Among Women Consulting at the Sexually Transmitted Infection Centre in la Reunion: A Cross-Sectional Study]

Introduction

Chlamydia trachomatis (CT) infection is the commonest bacterial sexually transmitted infection (STI) in the world. Often asymptomatic, it can lead to significant complications in women. In France, since 2003, systematic screening for CT in STI center has been recommended for women aged less than 25 year. The main objective of this study was to determine CT prevalence in patients attending STI centers in Reunion Island. The second objective was to explore the determinants of this infection.

Method

A cross-sectional survey using an anonymous questionnaire was conducted among women attending STI center in two hospitals in western and southern Reunion Island during one year. All women who had performed a CT PCR, based on vaginal self-swabs, were included.

Results

Among the 620 patients tested, the prevalence of infection was 6.6% (95% CI [4.7-8.6]). By age group, the highest prevalence was between 12 and 17 years with 14.3% positive tests compared to 7.5% and 3.9% respectively in 18-24 and 25-67 year age group (p = 0.003). The risk factors for CT were a young age (p = 0.02), a first sexual intercourse between 11 and 14 years old (p = 0.01), lack of previous STI screening history (p = 0.02), and the following motives for seeking screening: "partner unfaithfulness" (p = 0.01) and "infected partner" (p = 0.02).

Conclusion

This study highlights the high prevalence of CT among Reunionese minors. A more systematic screening and a reinforcement of STI awareness among young people in Reunion Island seem to be essential.

Azithromycin resistance in Treponema pallidum in Reunion Island: A cross-sectional study

OBJECTIVE

Since the beginning of the 21st century, Reunion Island has experienced a syphilis epidemic. Infected patients are mostly heterosexual, with a high proportion of women, suggesting that congenital syphilis is present on the island. To determine whether azithromycin can be used for mass treatment of syphilis on Reunion Island, we assessed the prevalence of macrolide resistance in Treponema pallidum (TP).

METHODS

This monocentric cross-sectional study was conducted at the Reunion Island University Hospital. Samples were collected from lesions suggestive of primary or secondary syphilis. Samples positive for TP by multiplex polymerase chain reaction (PCR) were sent to the French National Reference Centre (NRC) for further analysis. Nested PCR-tpp47 was performed on these samples for detection of TP-DNA; 23s rRNA was amplified by PCR in confirmed positive samples. The Restriction Fragment Length Polymorphism (RFLP) technique was performed on samples with amplified 23s rRNA for detection of the A2058G mutation.

RESULTS

A total of 129 samples were collected from 119 patients. Of these, 18 tested positive for TP using multiplex PCR and were sent to the NRC. Fifteen (83.3%) of the 18 samples were confirmed positive by nested PCR-tpp47, and 23s rRNA was amplified in only 7 (38.9%) samples. Azithromycin resistance was detected in all TP strains with amplified 23s rRNA.

CONCLUSION

Amplification of 23s rRNA was successful in only 7 TP strains, all of which displayed resistance to macrolides. Keeping in mind the small sample size of our study, this suggests that azithromycin should not be used for mass treatment of syphilis in Reunion Island.

Prevalence of urogenital, anal, and pharyngeal infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium: a cross-sectional study in Reunion island

Background

Recommendations for sexually transmitted infection (STI) screening vary significantly across countries. This study evaluated the prevalence of urogenital and extragenital infections with Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Mycoplasma genitalium (MG) in patients visiting a French STI clinic in the Indian Ocean region to determine whether current STI screening practices should be updated.

Methods

This cross-sectional study examined all patients who visited the STI clinic between 2014 and 2015. Triplex polymerase chain reaction screening for CT, NG, and MG was performed on urine, vaginal, pharyngeal, and anal specimens (FTD Urethritis Basic Kit, Fast Track Diagnostics, Luxembourg).

Results

Of the 851 patients enrolled in the study, 367 were women (367/851, 43.2%) and 484 were men (484/851, 56.0%). Overall, 826 urogenital specimens (826/851, 97.1%), 606 pharyngeal specimens (606/851, 71.2%), and 127 anal specimens (127/851, 14.9%) were taken from enrolled patients. The prevalence of urogenital CT and MG was high in women ≤25 years (19/186, 10.21%; 5/186, 2.69%) and in men who have sex with women ≤30 years (16/212, 7.54%; 5/212, 2.36%). Among patients with urogenital CT infection, 13.7% (7/51) had urethritis. All patients with urogenital MG infection were asymptomatic. Men who have sex with men had a high prevalence of pharyngeal CT (2/45, 4.44%) and NG (3/44, 6.81%) and a high prevalence of anal CT (2/27, 7.41%), NG (2/27, 7.40%), and MG (1/27, 3.70%). After excluding patients with concomitant urogenital infection, extragenital infections with at least 1 of the 3 pathogens were found in 20 swabs (20/91, 21.9%) taken from 16 patients (16/81, 19.7%), all of them asymptomatic.

Conclusions

Routine multisite screening for CT, NG, and MG should be performed to mitigate the transmission of STIs in high-risk sexually active populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05801-9.

Emergence of murine typhus in La Réunion, France, 2012-2017

OBJECTIVE

Murine typhus (MT) is an acute zoonosis caused by Rickettsia typhi, a flea-borne rickettsiosis. The first autochthonous case was reported in 2012. Once autochthonous transmission of Rickettsia typhi was proven, we performed a prospective study to describe and raise awareness of this often-misdiagnosed disease among physicians.

PATIENTS AND METHODS

We performed a prospective observational study of MT cases in La Réunion from 2012 to 2017. MT cases were defined as clinically compatible illnesses with a specific positive serology and/or PCR.

RESULTS

Sixty-one confirmed cases were collected. The main clinical features were prolonged fever (90%), asthenia (87%), and headaches (79%). The main biological abnormalities were elevated liver enzymes (84%) and thrombopenia (75%). Renal function was normal in 90% of cases; it was an important feature because leptospirosis is a frequent cause of acute renal failure. A seasonal factor was observed with 79% of cases reported in the warm season and most of them in the west and south of the island (i.e., the dry areas).

CONCLUSION

MT is an emerging disease in La Réunion, and local conditions could lead to an endemic situation. Cases of acute undifferentiated fever with headaches should guide to the diagnosis of MT especially in the warm season and dry areas. Leptospirosis is an alternative diagnosis, which differs from MT by its epidemiological characteristics and by the associated frequent renal dysfunction.

From phaeohyphomycosis to disseminated chromoblastomycosis: A retrospective study of infections caused by dematiaceous fungi

OBJECTIVE

Infections caused by dematiaceous fungi are more common in tropical and subtropical areas. We aimed to describe the clinical, microbiological and therapeutic aspects of case patients diagnosed at a University Hospital located on an Indian Ocean island.

PATIENTS AND METHODS

We performed an observational retrospective study of infections caused by dematiaceous fungi diagnosed at the University Hospital of Saint-Pierre, Reunion, from 2000 to 2015. Mycological identifications were performed at the National Reference Center for Invasive Mycosis and Antifungal Agents (Paris).

RESULTS

The review of clinical and microbiological data of 11 patients identified revealed that five were infected by dematiaceous fungi. Two had cutaneous phaeohyphomycosis, two had cerebral phaeohyphomycosis and one had cutaneous chromoblastomycosis with brain and potentially medullary dissemination. Skin lesions and cerebral abscesses were quite varied.

CONCLUSION

Infections caused by dematiaceous fungi are rare. Medullary and brain localizations are extremely rare, especially for chromoblastomycosis. Cutaneous manifestations of phaeohyphomycosis are varied; diagnosis is thus more difficult. It is therefore important, when confronted with a chronic tumor-like lesion in endemic areas, to perform a biopsy for pathology and fungal culture. While surgical excision is not always sufficient, medical treatment of these infections is not standardized, but relies on an azole, which can be associated with another antifungal agent.

Exacerbation d’asthme et virus : quelles différences en fonction des zones climatiques ?

Introduction

Les exacerbations d’asthme correspondent à des aggravations rapides des symptômes respiratoires et sont responsables d’une morbidité et mortalité importantes. Les infections virales figurent parmi les causes les plus fréquentes des exacerbations mais les données épidémiologiques sont, dans leur grande majorité, issues de cohorte de pays tempérés. Peu de données sont disponibles dans les pays tropicaux malgré une augmentation de la prévalence de l’asthme dans ces régions ces dernières années.

Méthodes

Dans cette étude observationnelle réalisée sur l’année 2015, l’épidémiologie virale de patients adultes hospitalisés pour exacerbation d’asthme a été comparée entre la ville de Saint Pierre à la Réunion (climat tropical) et de Tours (climat tempéré). Un portage viral était recherché à l’entrée à l’hôpital par polymerase chain reaction (PCR) multiplex sur aspiration nasopharyngée. Seize virus ont été analysés : VRS A et B, rhinovirus, métapneumovirus, myxovirus influenzae A, H1N1, H5N1, parainfluenzae de 1 à 4, coronavirus 229E, NL63 et OC43, adénovirus, entérovirus. À la Réunion, le panel de virus recherché comprenait en plus coronavirus HKU1, bocavirus et paréchovirus.

Résultats

Au total, 100 patients ont été inclus dont 62 à Saint Pierre et 38 à Tours. La présence d’au moins un virus est retrouvé dans les aspirations naso-pharyngées chez 53 % des patients à Tours et 31 % des patients à Saint Pierre (p < 0,05). La répartition des virus diffère selon la géolocalisation. Le rhinovirus est l’espèce la plus fréquemment retrouvée dans les 2 groupes : soit 42 % des prélèvements à Saint Pierre et 30 % à Tours. On trouve de façon équivalente, entre les groupes, le virus influenza A dans 19 % des cas. Le classement diverge ensuite, l’entérovirus qui représente 19 % des aspirations naso-pharyngées à Tours n’est pas retrouvé à Saint Pierre. Inversement, le virus influenza H1N1 et le virus para-influenza identifiés dans 12 et 4 % des prélèvements à Saint Pierre sont absents à Tours. Les exacerbations semblent avoir une saisonnalité à Tours avec un pic en septembre et en hiver. Aucune saisonnalité n’est retrouvée sous le climat tropical de la Réunion.

Conclusion

La proportion de patients hospitalisés pour exacerbation d’asthme et ayant un prélèvement viral positif est plus faible en climat tropical qu’en climat tempéré. L’origine de ces exacerbations reste donc à déterminer. Il est nécessaire d’étudier spécifiquement en zone tropicale d’autres facteurs environnementaux comme les allergènes (moisissures…) ou les parasites.

Deletion of the 1p32 region is a major independent prognostic factor in young patients with myeloma: the IFM experience on 1195 patients

Deletions of the 1p region appear as a pejorative prognostic factor in multiple myeloma patients (especially 1p22 and 1p32 deletions) but there is a lack of data on the real impact of 1p abnormalities on an important and homogeneous group of patients. To address this issue we studied by fluorescence in situ hybridization (FISH) the incidence and prognostic impact of 1p22 and 1p32 deletions in 1195 patients from the IFM (Institut Francophone du Myélome) cell collection. Chromosome 1p deletions were present in 23.3% of the patients (271): 15.1% (176) for 1p22 and 7.3% (85) for 1p32 regions. In univariate analyses, 1p22 and 1p32 appeared as negative prognostic factors for progression-free survival (PFS): 1p22: 19.8 months vs 33.6 months (P<0.001) and 1p32: 14.4 months vs 33.6 months (P<0.001); and overall survival (OS): 1p22: 44.2 months vs 96.8 months (P=0.002) and 1p32: 26.7 months vs 96.8 months (P<0.001). In multivariate analyses, 1p22 and 1p32 deletions still appear as independent negative prognostic factors for PFS and OS. In conclusion, our data show that 1p22 and 1p32 deletions are major negative prognostic factors for PFS and OS for patients with MM. We thus suggest that 1p32 deletion should be tested for all patients at diagnosis.

Heterogeneity of t(4;14) in multiple myeloma. Long-term follow-up of 100 cases treated with tandem transplantation in IFM99 trials

One hundred de novo multiple myeloma patients with t(4;14) treated with double intensive therapy according to IFM99 protocols were retrospectively analyzed. The median overall survival (OS) and event-free survival (EFS) were 41.4 and 21 months, respectively, as compared to 65 and 37 for patients included in the IFM99 trials without t(4;14) (P<10(-7)). We identified a subgroup of patients presenting at diagnosis with both low beta(2)-microglobulin <4 mg/l and high hemoglobin (Hb) >/=10 g/l (46% of the cases) with a median OS of 54.6 months and a median EFS of 26 months, respectively, which benefits from high-dose therapy (HDT); conversely patients with one or both adverse prognostic factor (high beta(2)-microglobulin and/or low Hb) had a poor outcome. The achievement of either complete response or very good partial response after HDT was also a powerful independent prognostic factor for both OS and EFS.

Sideroblastic anaemia during fusidic acid treatment

OBJECTIVES AND METHODS

To describe cases of fusidic acid-associated sideroblastic anaemia from the French Pharmacovigilance database.

RESULTS

Six cases of sideroblastic anaemia associated with oral fusidic acid treatment were retrieved. Four females and two males (mean age 65.3 yr) developed severe anaemia (mean haemoglobin level: 6.9 g/dL) within 32-190 d (mean: 81 d) of treatment. Bone marrow aspirates showed dyserythropoiesis and ringed sideroblasts in all patients. Four patients required repeated blood transfusions. After fusidic acid discontinuation in five patients, complete recovery was obtained. In one patient, rechallenge with fusidic acid resulted in recurrence of anaemia that resolved after definitive discontinuation of the drug.

CONCLUSION

Our data indicate that fusidic acid should be added to the list of drugs that can cause sideroblastic anaemia.

Clinical and pharmacokinetic phase II study of fotemustine in refractory and relapsing multiple myeloma patients

BACKGROUND

Patients with relapsing or refractory multiple myeloma have poor prognosis. Few compounds are active in these patients and response duration remains short. We report the results of an open phase II trial evaluating the efficacy and safety of fotemustine monotherapy.

PATIENTS AND METHODS

Twenty-one patients with relapsing (17) or refractory (four) multiple myeloma received fotemustine 100 mg/m(2) on an outpatient basis on days 1 and 8 of the induction cycle, followed after a 6-week rest period by fotemustine 100 mg/m(2) every 3 weeks until progression or unacceptable toxicity. Fotemustine pharmacokinetics during the first day of induction was compared between patients with normal or abnormal renal function.

RESULTS

Five of 20 eligible patients had an objective response giving an intention-to-treat response rate of 25% [95% confidence interval (CI) 6% to 44%] and a 35.7% response rate (95% CI 11% to 61%) in the 14 patients having received at least four injections of fotemustine. The median time to objective response was 8.9 months. The median times to progression and survival were 13.8 and 23.1 months, respectively, with a 2-year survival rate of 49%. The main toxicity was myelosuppression with grade 3-4 neutropenia and thrombocytopenia in 66% and 71% of patients, respectively. There was one toxic death by sepsis after induction. The pharmacokinetic parameters in renal-impaired patients were not significantly different from those in patients with normal renal function with a similar incidence of grade 3-4 toxicity in both groups.

CONCLUSIONS

Fotemustine as a single agent has definite activity in patients with relapsing or refractory multiple myeloma, with acceptable toxicity and can be administered at conventional doses in patients with mild or moderate renal impairment.

Randomized comparison of fludarabine, CAP, and ChOP in 938 previously untreated stage B and C chronic lymphocytic leukemia patients

To comparatively assess first-line treatment with fludarabine and 2 anthracycline-containing regimens, namely CAP (cyclophosphamide, doxorubicin plus prednisone) and ChOP (cyclophosphamide, vincristine, prednisone plus doxorubicin), in advanced stages of chronic lymphocytic leukemia (CLL), previously untreated patients with stage B or C CLL were randomly allocated to receive 6 monthly courses of either ChOP, CAP, or fludarabine (FAMP), stratified based on the Binet stages. End points were overall survival, treatment response, and tolerance. From June 1, 1990 to April 15, 1998, 938 patients (651 stage B and 287 stage C) were randomized in 73 centers. Compared to ChOP and FAMP, CAP induced lower overall remission rates (58.2%; ChOP, 71.5%; FAMP; 71.1%; P <.0001 for each), including lower clinical remission rates (CAP, 15.2%; ChOP, 29.6%; FAMP, 40.1%; P =.003). By contrast, median survival time did not differ significantly according to randomization (67, 70, and 69 months in the ChOP, CAP, and FAMP groups, respectively). Incidences of infections (< 5%) and autoimmune hemolytic anemia (< 2%) during the 6 courses were similar in the randomized groups, whereas fludarabine induced, compared to ChOP and CAP, more frequent protracted thrombocytopenia (P =.003) and less frequent nausea-vomiting (P =.003) and hair loss (P <.0001). For patients with stage B and C CLL first-line fludarabine and ChOP regimens both provided similar overall survival and close response rates, and better results than CAP. However, there was an increase in clinical remission rate and a trend toward a better tolerance of fludarabine over ChOP that may influence the choice between these regimens as front-line treatments in patients with CLL.

Spectrographic imaging. A bird's-eye view of the health of coral reefs

Almost three-quarters of the world's coral reefs are thought to be deteriorating as a consequence of environmental stress. Until now, it has been possible to evaluate reef health only by field survey, which is labour-intensive and time-consuming. Here we map live coral cover from the air by remote imaging, a technique that will enable the state of shallow reefs to be monitored swiftly and over large areas.

Genetic and physical delineation of the region overlapping the progressive motor neuropathy (pmn) locus on mouse chromosome 13

The mouse autosomal recessive mutation progressive motor neuropathy (pmn) results in early onset motor neuron disease with rapidly progressing hindlimb paralysis, severe muscular wasting, and death at 4--6 weeks of age. pmn is thus considered a good animal model for motor neuron diseases and the characterization of the causative gene should help in understanding the biological causes of human spinal muscular atrophies. Here we report the generation of a physical map based on a high-resolution and high-density genetic map encompassing the pmn locus on mouse chromosome 13. We have positioned the pmn locus and a cluster of markers cosegregating with it within a genetic interval of 0.30 cM, delineated by two clusters of markers. We have constructed an approximately 850-kb contig of BACs spanning the pmn critical region. This BAC contig contains the breakpoint of synteny between mouse chromosome 13 and human 1q and 7p regions and lays the foundation for identifying at the molecular level such a breakpoint region. The physical and genetic maps provided a support for the identification of five transcription units positioned in the nonrecombinant interval, and constitute invaluable tools for the identification of other candidate genes for the pmn mutation.

Response of a scleractinian coral, Stylophora pistillata, to iron and nitrate enrichment

The purpose of this study was to determine whether the addition of iron alone or in combination with nitrate affects growth and photosynthesis of the scleractinian coral, Stylophora pistillata, and its symbiotic dinoflagellates. For this purpose, we used three series of two tanks for a 3-week enrichment with iron (Fe), nitrate (N) and nitrate+iron (NFe). Two other tanks were kept as a control (C). Stock solutions of FeCl(3) and NaNO(3) were diluted to final concentrations of 6 nM Fe and 2 &mgr;M N and continuously pumped from batch tanks into the experimental tanks with a peristaltic pump. Results obtained showed that iron addition induced a significant increase in the areal density of zooxanthellae (ANOVA, p=0.0013; change from 6.3+/-0.7x10(5) in the control to 8.5+/-0.6x10(5) with iron). Maximal gross photosynthetic rates normalized per surface area also significantly increased following iron enrichment (ANOVA, p=0.02; change from 1.23+/-0.08 for the control colonies to 1.81+/-0.24 &mgr;mol O(2) cm(-2) h(-1) for the iron-enriched colonies). There was, however, no significant difference in the photosynthesis normalized on a per cell basis. Nitrate enrichment alone (2 &mgr;M) did not significantly change the zooxanthellae density or the rates of photosynthesis. Nutrient addition (both iron and nitrogen) increased the cell-specific density of the algae (CSD) compared to the control (G-test, p=0.3x10(-9)), with an increase in the number of doublets and triplets. CSD was equal to 1.70+/-0.04 in the Fe-enriched colonies, 1.54+/-0.12 in the N- and NFe-enriched colonies and 1.37+/-0.02 in the control. Growth rates measured after 3 weeks in colonies enriched with Fe, N and NFe were 23%, 34% and 40% lower than those obtained in control colonies (ANOVA, p=0.011).

A new family of genes and pseudogenes potentially expressing testis- and brain-specific leucine zipper proteins in man and mouse

We have characterized a new mouse gene highly transcribed in the testis, and a derived intronless gene expressed in the embryo. The latter gene is present in Mus musculus domesticus and in Mus musculus castaneus but is absent in Mus spretus. The sequencing of different clones from a testis cDNA library reveals a complex transcriptional regulation for the intron-containing gene. The use of several promoters, alternative splicing and trans-splicing, and of two different polyadenylation sites account for the diversity. The different cDNAs encode proteins with features of basic helix-loop-helix leucine zipper (bHLH-ZIP) DNA-binding factors with homology to a new brain-specific factor. The presence of multiple CK2 and PKC phosphorylation sites suggests that their activity may be regulated by phosphorylation. In man, a pseudogene, apparently derived from the same transcript as in mouse and showing 90% homology in the coding region, is present within an intron of another gene. Interestingly, although the human pseudogene is highly mutated in human, in the mouse it has only four nucleotide changes compared with the cDNA of origin, and is still capable of encoding a protein.

[Hodgkin disease of the palatine tonsil. Clinical, histological, immunophenotype study and association with Epstein-Barr virus]

OBJECTIVE

To characterize clinical, histological and immuno-phenotypical features of a rare Hodgkin's disease presentation.

METHODS

Retrospective analysis of three personal cases of Hodgkin's disease of the tonsil and a review of the literature.

RESULTS

The clinical presentation was localized in the tonsil in all three cases. Age at onset was over 40 years in all patients. Symptoms were typical. A mixed cellularity histological type was found in all 3 instances. Reed-Sternberg cells stained positively with anti-CD30 and anti-CD15 monoclonal antibodies as well as with an anti-Epstein-Barr virus (EBV) specific monoclonal antibody. All 3 patients are currently in complete remission although for a short period of time (35, 20 and 15 months).

CONCLUSION

This small series illustrates the main characteristics of this rare Hodgkin's disease presentation. Age at onset was older than the average for this disease which might explain the predominance of the mixed cellularity histologic subtype and the tighter linkage to EBV, although the rarity of such a presentation could raise some doubts about the EBV linkage. Prognosis of this unusual presentation does not appear to be different from that for more common presentations.

Three new allelic mouse mutations that cause skeletal overgrowth involve the natriuretic peptide receptor C gene (Npr3)

In 1979, a BALB/cJ mouse was identified with an exceptionally long body. This phenotype was found to be caused by a recessive mutation, designated longjohn (lgj), that mapped to the proximal region of chromosome 15. Several years later, a mouse with a similarly elongated body was identified in an outbred stock after chemical mutagenesis with ethylnitrosourea. This phenotype also was caused by a recessive mutation, designated strigosus (stri). The two mutations were found to be allelic. A third allele was identified in a DBA/2J mouse and was designated longjohn-2J (lgj(2J)). Analysis of skeletal preparations of stri/stri mice indicated that the endochondral ossification process was slightly delayed, resulting in an extended proliferation zone. A recent study reported that mice overexpressing brain natriuretic peptide, one of the members of the natriuretic peptide family, exhibit a skeletal-overgrowth syndrome with endochondral ossification defects. The Npr3 gene coding for type C receptor for natriuretic peptides (NPR-C), which is mainly involved in the clearance of the natriuretic peptides, mapped in the vicinity of our mouse mutations and thus was a candidate gene. The present study reports that all three mutations involve the Npr3 gene and provides evidence in vivo that there is a natriuretic-related bone pathway, underscoring the importance of natriuretic peptide clearance by natriuretic peptide type C receptor.

Cloning of a calcium channel alpha1 subunit from the reef-building coral, Stylophora pistillata

While the mechanisms of cellular Ca2+ entry associated with cell activation are well characterized, the pathway of continuous uptake of the large amount of Ca2+ needed in the biomineralization process remains largely unknown. Scleractinian corals are one of the major calcifying groups of organisms. Recent studies have suggested that a voltage-dependent Ca2+ channel is involved in the transepithelial transport of Ca2+ used for coral calcification. We report here the cloning and sequencing of a cDNA coding a coral alpha1 subunit Ca2+ channel. This channel is closely related to the L-type family found in vertebrates and invertebrates. Immunohistochemical analysis shows that this channel is present within the calicoblastic ectoderm, the site involved in calcium carbonate precipitation. These data and previous results provide molecular evidence that voltage-dependent Ca2+ channels are involved in calcification. Cnidarians are the most primitive organisms in which a Ca2+ channel has been cloned up to now; evolutionary perspectives on Ca2+ channel diversity are discussed.

Organic matrix synthesis in the scleractinian coral stylophora pistillata: role in biomineralization and potential target of the organotin tributyltin

The kinetics of organic matrix biosynthesis and incorporation into scleractinian coral skeleton was studied using microcolonies of Stylophora pistillata. [14C]Aspartic acid was used to label the organic matrix since this acidic amino acid can represent up to 50 mol % of organic matrix proteins. External aspartate was rapidly incorporated into tissue protein without any detectable lag phase, suggesting either a small intracellular pool of aspartic acid or a pool with a fast turn-over rate. The incorporation of 14C-labelled macromolecules into the skeleton was linear over time, after an initial delay of 20 min. Rates of calcification, measured by the incorporation of 45Ca into the skeleton, and of organic matrix biosynthesis and incorporation into the skeleton were constant. Inhibition of calcification by the Ca2+ channel inhibitor verapamil reduced the incorporation of organic matrix proteins into the skeleton. Similarly, organic matrix incorporation into the skeleton, but not protein synthesis for incorporation into the tissue compartment, was dependent on the state of polymerization of both actin and tubulin, as shown by the sensitivity of this process to cytochalasin B and colchicin. These drugs may inhibit exocytosis of organic matrix proteins into the subcalicoblastic space. Finally, inhibition of protein synthesis by emetin or cycloheximide and inhibition of N-glycosylation by tunicamycin reduced both the incorporation of macromolecules into the skeleton and the rate of calcification. This suggests that organic matrix biosynthesis and its migration towards the site of calcification may be a prerequisite step in the calcification process. On the basis of these results, we investigated the effects of tributyltin (TBT), a component of antifouling painting known to interfere with biomineralization processes. Our results have shown that this xenobiotic significantly inhibits protein synthesis and the subsequent incorporation of protein into coral skeleton. This effect was correlated with a reduction in the rate of calcification. Protein synthesis was shown to be the parameter most sensitive to TBT (IC50=0.2 micromol l-1), followed by aspartic acid uptake by coral tissue (IC50=0.6 micromol l-1), skeletogenesis (IC50=3 micromol l-1) and Ca2+ uptake by coral tissue (IC50=20 micromol l-1). These results suggest that the mode of action of TBT on calcification may be the inhibition of organic matrix biosynthesis.

Chlorambucil in indolent chronic lymphocytic leukemia. French Cooperative Group on Chronic Lymphocytic Leukemia

BACKGROUND

To determine whether chlorambucil treatment benefits patients with indolent chronic lymphocytic leukemia (CLL), we conducted two randomized trials in 1535 patients with previously untreated stage A CLL.

METHODS

In the first trial, 609 patients were randomly assigned to receive either daily chlorambucil or no treatment; in the second trial, 926 patients were randomly assigned to receive either intermittent chlorambucil plus prednisone or no treatment. Median follow-up for the first and second trials exceeded 11 and 6 years, respectively. The end points were overall survival, response to treatment, and disease progression.

RESULTS

Treatment of indolent CLL did not increase survival in either trial. In the treated group, as compared with the untreated group, the relative risk of death was 1.14 (95 percent confidence interval, 0.92 to 1.41; P=0.23) in the first trial and 0.96 (95 percent confidence interval, 0.75 to 1.23; P=0.74) in the second trial, with 76 percent and 69 percent of patients, respectively, having a response to therapy. Although chlorambucil slowed disease progression, there was no effect on overall survival. In the untreated group in the first trial, 49 percent of patients did not have progression to more advanced disease and did not need therapy after follow-up of more than 11 years; however, 27 percent of patients with stage A CLL died of causes related to the disease.

CONCLUSIONS

Chlorambucil does not prolong survival in patients with stage A CLL. Since deferring therapy until the disease progresses to stage B or C does not compromise survival, treatment of indolent CLL is unnecessary.

Functional polarity of the tentacle of the sea anemone Anemonia viridis: role in inorganic carbon acquisition

The oral epithelial layers of anthozoans have a polarized morphology: photosynthetic endosymbionts live within endodermal cells facing the coelenteric cavity and are separated from the external seawater by the ectodermal layer and the mesoglea. To study if this morphology plays a role in the supply of inorganic carbon for symbiont photosynthesis, we measured the change in pH and the rate of OH- (H+) fluxes induced by each cell layer on a tentacle of the sea anemone Anemonia viridis. Light-induced pH increase of the medium bathing the endodermal layers led to the generation of a transepithelial pH gradient of approximately 0.8 pH units across the tentacle, whereas darkness induced acidification of this medium. The light-induced pH change was associated with an increase of total alkalinity. Only the endodermal layer was able to induce a net OH- secretion (H+ absorption). The light-induced OH- secretion by the endodermal cell layer was dependent on the presence of HCO3- in the compartment facing the ectoderm and was sensitive to several inhibitors of ion transport. [14C] HCO3- incorporation into photosynthates confirmed the ectodermal supply, the extent of which varied from 25 to > 90%, according to HCO3- availability. Our results suggest that the light-induced OH- secretion by the endodermal cell layer followed the polarized transport of HCO3- and its subsequent decarboxylation within the endodermal cell layer. This polarity may play a significant role both in inorganic carbon absorption and in the control of light-enhanced calcification in scleractinian corals.

Follicular large-cell lymphoma treated with intensive chemotherapy: an analysis of 89 cases included in the LNH87 trial and comparison with the outcome of diffuse large B-cell lymphoma. Groupe d'Etude des Lymphomes de l'Adulte

PURPOSE

The aims of this study were as follows: (1) to analyze clinical, histopathologic characteristics, treatment outcome, and prognostic factors of patients with follicular large-cell lymphoma (FLCL); and (2) to compare them with those of patients with diffuse large B-cell lymphoma (DLCL) treated in the same therapeutic trial.

PATIENTS AND METHODS

Eighty-nine FLCL patients who were histologically reviewed and who received an intensive chemotherapy regimen according to the LNH 87 protocol were analyzed and compared with 1,096 B-cell DLCL patients included in the same protocol.

RESULTS

After intensive induction treatment, 59 patients (67%) achieved a complete remission [CR]. Estimated 5-year survival was 59%, and estimated 5-year freedom from progression (FFP) was 39%. Prognostic factors associated with shorter FFP were age greater than 60 years (P = .02), advanced clinical stage (P = .01), abnormal lactic dehydrogenase (LDH) level (P = .02), abnormal beta-2 microglobulin (P = .02), B symptoms (P = .03), bone marrow involvement (P = .04), and high expression of bcl-2 protein (P = .05). When compared with B-cell DLCL patients, FLCL patients were younger (P = .02), had a better Eastern Cooperative Oncology Group (ECOG) status (P = .05), less bulky mass (P = .04), more advanced clinical stages (P < .001), and more bone marrow involvement (P = .02). No significant difference was observed between FLCL and DLCL patients for response to therapy (67% v 67% of CR), 5-year overall survival (58% v 51%), 5-year disease-free survival (53% v 57%), or FFP survival (39% v 43%).

CONCLUSION

FLCL patients have a favorable response rate and survival when treated with intensive chemotherapy. Their outcome is similar to that of B-cell DLCL patients, and a long-term FFP is observed for a substantial number of patients. Some adverse prognostic factors (including those of the International Prognostic Index, bone marrow involvement, and beta-2 microglobulin) have been identified to define a subset of patients who require other therapeutic approach.

A compartmental approach to the mechanism of calcification in hermatypic corals

Ca2+ compartments, Ca2+ transport and the calcification process were studied by using 45Ca as a tracer. The biological model used was clones of Stylophora pistillata developed into microcolonies whose skeleton is entirely covered by tissues, thus avoiding direct radioisotope exchange between the sea water and the skeleton. The study of Ca2+ compartments was performed by measuring two complementary parameters: Ca2+ influx and Ca2+ efflux kinetics. Kinetic analysis of 45Ca uptake revealed three exchangeable and one non-exchangeable Ca2+ compartments in these microcolonies. The first compartment was saturable with a short half-time (4 min), correlated to external Ca2+ concentration and insensitive to metabolic or ion transport inhibitors. This compartment (72.88 nmol Ca2+ mg-1 protein) has been previously attributed to sea water present in the coelenteron. The second Ca2+ compartment (7.12 nmol Ca2+ mg-1 protein) was soluble in NaOH, saturable with a half-time of 20 min and displayed a combination of Michaelis-Menten kinetics and diffusional entry. It was insensitive to a variety of inhibitors but its loading was stimulated by Ca2+ channel inhibitors. On the basis of uptake experiments, the existence of a third compartment with a rapid turnover rate (about 2 min) and a very small size is predicted. It is suggested that this compartment corresponds to the calicoblastic epithelium. Ca2+ flux through this compartment was facilitated by voltage-dependent Ca2+ channels (with L-type characteristics) and Ca2+-ATPase and was coupled to an anion carrier. Transcellular Ca2+ movement was dependent on the cytoskeleton. The rate of Ca2+ flux across this epithelium was about 975 pmol mg-1 protein min-1. The fourth calcium compartment, corresponding to the skeleton, was soluble in HCl and non-exchangeable. After a short lag phase (about 2 min), the rate of Ca2+ deposition was linear over a period of at least 5 h. The calcification rate was 975 pmol mg-1 protein h-1 at an irradiance of 175 &micro;mol photons m-2 s-1. It followed Michaelis-Menten kinetics and saturated at levels (9 mmol l-1) close to the Ca2+ concentration of sea water. Wash-out (efflux) experiments employing several different protocols allowed identification of six compartments. The first two compartments were extracellular (bulk extracolonial water and coelenteron). The third compartment may be part of the second Ca2+ compartment identified by influx experiments. A fourth compartment was sensitive to the Ca2+ channel inhibitor D600 and appeared to be associated with the NaOH-soluble (tissue) Ca2+ pool. Two compartments were identified during skeletal efflux, the first being small and due to either tissue carry-over or a labile skeletal compartment. The second compartment corresponded to bulk skeletal deposition. The various efflux protocols produced varying estimates of tissue Ca2+ levels and calcification rates and, thus, coral post-incubation processing has a profound impact on experimental interpretation.

[Follow-up of allogenic bone marrow graft with DNA polymorphisms. Use of two minisatellite MS31 and MS43 probes. Comparison with data of chromosomal polymorphisms]

OBJECTIVES

Allogenic bone marrow transplantation is widely used to treat many diseases of the haemopoietic system as well as metabolic disorders. Follow-up is essential to assess acceptance, rejection or post-graft relapse. This study was undertaken to evaluate the usefulness of the minisatellite probes MS31 and MS43 used as a routine follow-up test after bone marrow transplantation.

METHODS

Twenty receivers of allogenic bone marrow transplants were followed-up. Two monoclonal minisatellite probes, MS31 and MS43, were used for comparison with the classical polymorphism methods.

RESULTS

Fourteen cases of total chimeras, 3 cases of rejections and 3 cases of mixed chimeras were observed with the molecular probe techniques. In 19 of the 20 cases, this technique gave results compatible with classical polymorphism results.

CONCLUSIONS

The minisatellite probes MS31 and MS43 were found to be sensitive, effective tests for bone marrow transplants which can be used in routine follow-up.