Search

Purpose : To investigate the response of Sertoli cell function to 60Co gamma -rays. Materials and methods : Rat Sertoli cells were exposed in vitro and in vivo to 60Co gamma -rays in the dose range 3Gy to 48Gy and at 3Gy and 6Gy respectively. Cell viability and transferrin and IL-6 production were measured at different times following irradiation. Results : This study confirms the resistance of in vitro irradiated rat Sertoli cells in the dose range 3Gy to 48Gy in terms of cell number. Radiation had no effect on the IL-1 activity of Sertoli cells. However, the experiments show that despite the absence of a macroscopic effect, Sertoli cells respond to ionizing radiation by increasing transferrin secretion, transferrin response to (Bu)2 cAMP stimulation and IL-6 activity. Conclusions : Transferrin is involved in the transport of iron into germ cells and in cell di fferentiation. IL-6 is a potent inhibitor of meiotic DNA synthesis. Radio-induced transferrin and IL-6 could play a role in the protection of germ cells and could explain, in part, the resistance of Sertoli cells to radiation. [ABSTRACT FROM AUTHOR]

This report describes a patient without evident underlying disease, in whom an acquired von Willebrand's syndrome was discovered before surgery. Coagulation abnormalities included a borderline bleeding time, a low retention of platelets on glass beads, decreased levels of factor VIII procoagulant activity (VIIIAHF), factor VIII-related antigen (VIIIAg), and ristocetin-induced agglutination cofactor (VIIIVWF). After cryoprecipitate infusion the patient did not have the expected rise and there was no secondary increment in VIIIAHF. The patient was treated with prednisone for three weeks without significant improvement in the laboratory findings. Spontaneous resolution was observed long after this therapy. The haemostatic abnormalities were attributable to the presence of an inhibitor directed against VIIIVWF. The inhibitor was found in the IgM fraction. Its autoimmune nature is probable although we failed to demonstrate any inhibitory effect of Fab obtained from the patient's purified IgM. Despite the lack of inhibitory effect against VIIIAHF and VIIIAg, the low levels of all three activities of the factor VIII complex could be explained by the short half-life of immune complexes between factor VIII and the inhibitor. [ABSTRACT FROM PUBLISHER]

Serum containing a monoclonal IgM protein from a patient with Waldenstroms' macroglobulinaemia gave intense immunofluorescent staining of kidney nuclei. The Fab mu fragments of this immunoglobulin were obtained. The IgM and Fab fragments reacted in vitro with kidney nuclei using unfixed cryostat sections of rat or mouse kidney. After treatment of the patient with chemotherapy, the monoclonal IgM disappeared, and no more antinuclear activity could be detected in the serum. The results strongly suggest that this IgM protein had antinuclear activity. [ABSTRACT FROM PUBLISHER]

Mitochondrial DNA has been a popular marker in phylogeography, phylogeny, and molecular ecology, but its complex evolution is increasingly recognized. Here, we investigated mitochondrial DNA variation in Anopheles gambiae and Anopheles coluzzii, in relation to other species in the Anopheles gambiae complex, by assembling the mitogenomes of 1,219 mosquitoes across Africa. The mitochondrial DNA phylogeny of the Anopheles gambiae complex was consistent with previously reported highly reticulated evolutionary history, revealing important discordances with the species tree. The three most widespread species (An. gambiae, An. coluzzii, and Anopheles arabiensis), known for extensive historical introgression, could not be discriminated based on mitogenomes. Furthermore, a monophyletic clustering of the three saltwater-tolerant species (Anopheles merus, Anopheles melas, and Anopheles bwambae) in the Anopheles gambiae complex also suggested that introgression and possibly selection shaped mitochondrial DNA evolution. Mitochondrial DNA variation in An. gambiae and An. coluzzii across Africa revealed significant partitioning among populations and species. A peculiar mitochondrial DNA lineage found predominantly in An. coluzzii and in the hybrid taxon of the African "far-west" exhibited divergence comparable to the interspecies divergence in the Anopheles gambiae complex, with a geographic distribution matching closely An. coluzzii's geographic range. This phylogeographic relict of the An. coluzzii and An. gambiae split was associated with population and species structure, but not with the rare Wolbachia occurrence. The lineage was significantly associated with single nucleotide polymorphisms in the nuclear genome, particularly in genes associated with pathogen and insecticide resistance. These findings underline potential mitonuclear coevolution history and the role played by mitochondria in shaping metabolic responses to pathogens and insecticides in Anopheles., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

The availability of an ever-increasing diversity of prokaryotic genomes and metagenomes represents a major opportunity to understand and decipher the mechanisms behind the functional diversification of microbial biosynthetic pathways. However, it remains unclear to what extent a pathway producing a specific molecule from a specific precursor can diversify. In this study, we focus on the biosynthesis of ubiquinone (UQ), a crucial coenzyme that is central to the bioenergetics and to the functioning of a wide variety of enzymes in Eukarya and Pseudomonadota (a subgroup of the formerly named Proteobacteria). UQ biosynthesis involves three hydroxylation reactions on contiguous carbon atoms. We and others have previously shown that these reactions are catalyzed by different sets of UQ-hydroxylases that belong either to the iron-dependent Coq7 family or to the more widespread flavin monooxygenase (FMO) family. Here, we combine an experimental approach with comparative genomics and phylogenetics to reveal how UQ-hydroxylases evolved different selectivities within the constrained framework of the UQ pathway. It is shown that the UQ-FMOs diversified via at least three duplication events associated with two cases of neofunctionalization and one case of subfunctionalization, leading to six subfamilies with distinct hydroxylation selectivity. We also demonstrate multiple transfers of the UbiM enzyme and the convergent evolution of UQ-FMOs toward the same function, which resulted in two independent losses of the Coq7 ancestral enzyme. Diversification of this crucial biosynthetic pathway has therefore occurred via a combination of parallel evolution, gene duplications, transfers, and losses., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

We present here FrangiPANe, a pipeline developed to build panreference using short reads through a map-then-assemble strategy. Applying it to 248 African rice genomes using an improved CG14 reference genome, we identified an average of 8 Mb of new sequences and 5290 new contigs per individual. In total, 1.4 G of new sequences, consisting of 1 306 676 contigs, were assembled. We validated 97.7% of the contigs of the TOG5681 cultivar individual assembly from short reads on a newly long reads genome assembly of the same TOG5681 cultivar. FrangiPANe also allowed the anchoring of 31.5% of the new contigs within the CG14 reference genome, with a 92.5% accuracy at 2 kb span. We annotated in addition 3252 new genes absent from the reference. FrangiPANe was developed as a modular and interactive application to simplify the construction of a panreference using the map-then-assemble approach. It is available as a Docker image containing (i) a Jupyter notebook centralizing codes, documentation and interactive visualization of results, (ii) python scripts and (iii) all the software and libraries requested for each step of the analysis. We foreseen our approach will help leverage large-scale illumina dataset for pangenome studies in GWAS or detection of selection., (© The Author(s) 2023. Published by Oxford University Press on behalf of NAR Genomics and Bioinformatics.)

Most bacteria can generate ATP by respiratory metabolism, in which electrons are shuttled from reduced substrates to terminal electron acceptors, via quinone molecules like ubiquinone. Dioxygen (O 2 ) is the terminal electron acceptor of aerobic respiration and serves as a co-substrate in the biosynthesis of ubiquinone. Here, we characterize a novel, O 2 -independent pathway for the biosynthesis of ubiquinone. This pathway relies on three proteins, UbiT (YhbT), UbiU (YhbU), and UbiV (YhbV). UbiT contains an SCP2 lipid-binding domain and is likely an accessory factor of the biosynthetic pathway, while UbiU and UbiV (UbiU-UbiV) are involved in hydroxylation reactions and represent a novel class of O 2 -independent hydroxylases. We demonstrate that UbiU-UbiV form a heterodimer, wherein each protein binds a 4Fe-4S cluster via conserved cysteines that are essential for activity. The UbiT, -U, and -V proteins are found in alpha-, beta-, and gammaproteobacterial clades, including several human pathogens, supporting the widespread distribution of a previously unrecognized capacity to synthesize ubiquinone in the absence of O 2 Together, the O 2 -dependent and O 2 -independent ubiquinone biosynthesis pathways contribute to optimizing bacterial metabolism over the entire O 2 range. IMPORTANCE In order to colonize environments with large O 2 gradients or fluctuating O 2 levels, bacteria have developed metabolic responses that remain incompletely understood. Such adaptations have been recently linked to antibiotic resistance, virulence, and the capacity to develop in complex ecosystems like the microbiota. Here, we identify a novel pathway for the biosynthesis of ubiquinone, a molecule with a key role in cellular bioenergetics. We link three uncharacterized genes of Escherichia coli to this pathway and show that the pathway functions independently from O 2 In contrast, the long-described pathway for ubiquinone biosynthesis requires O 2 as a substrate. In fact, we find that many proteobacteria are equipped with the O 2 -dependent and O 2 -independent pathways, supporting that they are able to synthesize ubiquinone over the entire O 2 range. Overall, we propose that the novel O 2 -independent pathway is part of the metabolic plasticity developed by proteobacteria to face various environmental O 2 levels., (Copyright © 2019 Pelosi et al.)

The ubiquitously expressed CLC chloride transporters are involved in a great variety of physiological functions. The CLC protein fold is shared by Cl - channels and 2Cl - :1H + antiporters. The antiporters pump three charges per cycle across the membrane with two Cl ions moving in the opposite direction of one proton. Multiconformational continuum electrostatics was used to calculate the coupled thermodynamics of the protonation of the extracellular-facing gating Glu (E x ) and Cl - binding to the external (S x ) and central (S c ) sites in CLC-ec1, the Escherichia coli exchanger. S x , S c , and E x are buried within the protein where the intersection of two helix N-termini creates a region with a strong, localized positive potential for anion binding. Our chemical potential titrations describe the thermodynamic linkage for binding the Cl - to each site and protons to E x . We find that the 2Cl - :1H + binding stoichiometry is a result of Cl - binding to S x requiring H + binding to E x , whereas Cl - binding to S c does not lead to proton uptake. When S x binds a Cl - , the protonated E x moves upward, out of the positive helix cage. The increasing E x proton affinity on binding the first Cl - reduces the cost of binding the second Cl - at either S x or S c . Despite the repulsion among the anions, the lowest energy states have two anions bound in the helix cage. The state with no Cl - is not favored electrostatically, but relies on E x blocking S x and on the central residues Y445 and S107 blocking S c ., (Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

We explore the application of a previously suggested formula for determining the degree of charge transfer in surface-enhanced Raman scattering (SERS). SERS is often described as a phenomenon which obtains its enhancement from three major sources, namely the surface plasmon resonance, charge-transfer resonances as well as possible molecular resonances. At any chosen excitation wavelength, it is possible to obtain contributions from several sources and this has led to considerable confusion. The formula for the degree of charge transfer enables one to separate these effects, but it requires that spectra be obtained either at two or more different excitation wavelengths or as a function of applied potential. We apply this formula to several examples, which display rather large charge-transfer contributions to the spectrum. These are p-aminothiophenol (PATP), tetracyano-ethylene (TCNE) and piperidine. In PATP we can show that several lines of the same symmetry give the same degree of charge transfer. In TCNE we are able to identify the charge-transfer transition, which contributes to the effect, and are able to independently determine the degree of charge transfer by wavenumber shifts. This enables a comparison of the two techniques of measurement. In piperidine, we present an example of molecule to metal charge transfer and show that our definition of charge transfer is independent of direction.

Background: The overproduction of ROS by ionizing irradiation induces cellular damage which can be reduced by specific molecules such as GSH and cytokines. The aim of this study was to determine the relationship between the well known radioresistance of Sertoli cells and astrocytes in vitro and the GSH level and IL-6 production after irradiation., Materials and Methods: Cell viability, GSH content and IL-6 production were assessed at different times after irradiation and for different doses, on rat Sertoli cells and astrocytes., Results: After irradiation we observed a dose-dependent increase in the intracellular total GSH level and IL-6 production as compared to the controls., Discussion: These results strongly suggest the key role of GSH and IL-6 in the mechanisms of response of radioresistant cells to gamma irradiation. One hypothesis is that the increase of GSH level and IL-6 production after irradiation contributes to the adaptative response to oxidative stress generated by gamma irradiation.

Interleukin 1(IL-1) and IL-6 are cytokines involved in the response to radiation and are known for their radioprotective properties with respect to total-body irradiation. We previously showed that after gamma irradiation of Sertoli cells (SC), we observed an increase in the activity of IL-6 but not of IL-1. The aim of this study was to see whether this response is a function of the differentiation of SC, to analyse the mechanisms responsible for this induction, and to test whether this cytokine has a radioprotective role on germ cells. Unlike IL-1, a dose-dependent increase of IL-6 activity in SC following gamma irradiation at high doses was observed at all ages studied. On the other hand, radio-induction observed at low doses (<1Gy) was dose-independent. IL-6 up-regulation resulted from transcriptional activation as shown by the use of specific inhibitors. The injection of IL-1 and IL-6 in mice prior to whole-body irradiation resulted in an increased survival rate. Moreover, cytokines protected DNA from remaining cells following irradiation as shown by comet assay on germ cells. In conclusion, IL-6 seems to constitute a good marker of exposure to gamma irradiation, both at low and high doses. In addition, we showed that IL-1 and IL-6 have a radioprotective effect at testicular level., (Copyright 2001 Academic Press.)

In human radiation protection, the shape of the dose effects curve for low doses irradiation (LDI) is assumed to be linear, extrapolated from the clinical consequences of Hiroshima and Nagasaki nuclear explosions. This extrapolation probably overestimates the risk below 200 mSv. In many circumstances, the living species and cells can develop some mechanisms of adaptation. Classical epidemiological studies will not be able to answer the question and there is a need to assess more sensitive biological markers of the effects of LDI. The researches should be focused on DNA effects (strand breaks), radioinduced expression of new genes and proteins involved in the response to oxidative stress and DNA repair mechanisms. New experimental biomolecular techniques should be developed in parallel with more conventional ones. Such studies would permit to assess new biological markers of radiosensitivity, which could be of great interest in radiation protection and radio-oncology.

Purpose: Retrospective analysis of the results of radiotherapy in localized prostatic adenocarcinoma. Complications were excluded., Patients and Methods: Six-hundred-and-ten T1-T2 adenocarcinomas of the prostate were treated with continuous courses of external beam radiation therapy in 19 participating Institutes between January 1983 and January 1988. The mean follow-up was 10.4 years; the mean age of patients at the beginning of radiotherapy was 68.5 years., Results: A 10-year, local control had been achieved in 86% of T1-T2 (81.4% for T2). The 5- and 10-year metastatic relapse rates were 25.3% and 30% (29% and 38.1% for T2), respectively. At 10 years, 62.4% of T1-T2 were recurrence-free; overall survival rate was 45.8% and cause-specific survival rate was 70.5%; 29.9% of T1-T2 patients were alive and disease-free. T category (TNM), pathologic grade, pelvic lymph node status, local tumor control, and obstructive ureteral symptoms were correlated with survival. The influence of pelvic nodes radiation, dose, overall treatment time, previous endocrine treatment, and transuretral resection was not significant for disease-free survival (alive and disease-free) and other endpoints., Conclusion: There was no difference between the French series (1975-1982 and 1983-1988). The results of the literature are comparable to ours. As far as prognostic factors are concerned, this report provides evidence that the explainable variables which influence survival depend on the tumor and patient status.

The aim of this work was to develop an animal model of accessible colonic tumours simulating human carcinogenesis. A segment of the colon was exteriorized to the skin in 60 rats and swabbed with N-methyl-N-nitrosourea. All the animals developed tumoral abnormalities or frank dysplasic tissue 7 months after the beginning of the experiment. This animal model which closely mimics human colonic carcinogenesis is particularly interesting because tumour development can be monitored in live animals without interrupting normal intestinal functions.

From 1986 to 1992, 55 cases of PPWC were treated with a conservative intent at the Regional Cancer Center (Rennes, France) and Saint-Yves Center (Vannes, France): 16 oropharyngeal posterior wall carcinoma (OP) and 39 hypopharyngeal posterior wall (HP); the mean age of the population was 60.3 years (31-81 years). A previous and simultaneous head and neck cancer was noted in 15 and 13% of cases respectively. Half of the cases (55%) were T1 T2 tumors and 82% were N0 N1. Except for three patients treated by curietherapy (5%), all patients were treated by radiotherapy (RT) alone (75%) or associated with curietherapy (7%) or partial pharyngectomy (13%). 15% received neoadjuvant chemotherapy, mainly for T3 tumors. With a followup of 4-88 months (mean: 23 months) 38% of patients are still alive; 8% of loco-regionally controlled patients died of second cancer or intercurrent disease. The tumor control was 67%. The nodes control was 90%. During the course of the disease, 19% of patients had metastases. The complete response at the end of treatment was 78%. Among these patients, 54% remained definitively free of disease. There is no difference between OP and HP. The analysis of survival curves showed the following points: significant difference between T1 T2, and T2 T3 (P < 0.05), N0 N1 and N2 N3 (P < 0.03), well differentiated histology or not (P < 0.02), RT alone or associated with curietherapy or surgery (P < 0.03) even for limited tumors T1 T2 N0 N1 (P < 0.03). There was no significant difference between group treated or not by chemotherapy even for T3 tumors. These findings do not differ if we consider either OP or HP. We conclude that OP and HP have the same prognostic factors and must be considered as the same clinical entity. For limited tumors T1 T2 N0 N1, patients managed by radiotherapy associated with complementary local treatment (conservative surgery or curietherapy) do better than patients treated by RT alone (plateau 80% at 18 months+vs plateau 25% at 12 months +). For these limited tumors, our recommendation is to treat patients by external RT (50 Gy) and curietherapy boost (20 Gy) rather than by conservative surgery and external RT (70 Gy). These two treatments have the same efficacity but the first one is expected to diminish late complications of RT. Neo adjuvant chemotherapy does not seen to improve survival even for advanced tumors. Generally speaking these results remain poor for locally advanced desease and for undifferentiated tumors. These patients need a new therapeutic approach (concomittant radio-chemotherapy, hyper or hypofonctionnated RT).

The authors report the results of a multicentric randomised trial assessing the effects on survival of neoadjuvant chemotherapy with cisplatin (100 mg/m2, D1) and fluorouracil (1 g/m2, D2-4) delivered before regional treatment in patients with squamous cell carcinoma of hypopharynx and base of tongue. 133 patients were enrolled in the study, and 121 were included in the analysis, 64 in group A (regional treatment alone) and 27 in group B (chemotherapy followed by regional treatment). Despite a high objective response rate to chemotherapy (primary tumour: 85%, 24% complete; nodes: 63%), overall survival was not significantly higher in group B than in group A.

An unusual protocol based on a preliminary clinical study on cylindromas metastasized to the lung was proposed to brain glioma patients: Day 2 100 mg/m2 i.v. Cis platinum (Cis PII) followed at days 3 and 5 by 6 Gy irradiation (RT) in two fractions and three days. Five cycles were scheduled at 21 days interval. On disease progression a three fractions per day radiotherapy regimen (3 FRT) in split-course (two series of 22.50 Gy in 15 fractions and five days separated by a two weeks period of rest) was then delivered to the patients. All patients had a measurable mass on the CT scan. 19 were entered into the study: 13 as first line therapy (group A) and six for salvage treatment (group B). Tolerance was globally good. Eight patients were considered responders at the end of five cycles of Cis PII-RT. They were all group A patients. Median symptom-free interval was six months for the whole population. Survival was twelve months. The 3 FRT was well tolerated but does not seem to have improved the therapeutic gain of the chemoradiotherapy combination. The present study concerns patients whose prognosis was poor on inclusion: surgery inadvisable or unsatisfactory and diagnosis mainly based on biopsy only. The number and the duration of responses justify further study into Cis PII as first line therapy as either an effective cytotoxic drug or a potential radio enhancer.

From 1982 to 1987, a randomized phase III trial was performed in order to determine the long-term effect of induction chemotherapy before standard pelvic irradiation in stage IIb-N1, III squamous cell carcinomas of the cervix. Patients were randomized to either chemotherapy and radiotherapy (C + R group) vs radiotherapy alone (R group). Radiotherapy for all patients consisted of 50 Gy in the pelvis with a boost by external irradiation or by brachytherapy (cumulative dose of 68 Gy). The chemotherapy regimen was an association of methotrexate (10 mg/m2, D2-4), chlorambucil (4 mg/m2, D1-5), vincristine (0,7 mg/m2, D1), cisplatin (80 mg/m2, D5), given every 3 wks; at least 2 courses were to be given before assessing efficacy and 2 more courses were given to patients who responded. One hundred and fifty-one patients were fully evaluable, after a mean follow-up of 38 mths (range 2-7 years), 76 in the R arm and 75 in the C + R arm. The response rate (greater than 50%) to chemotherapy was 42.5%. After completion of treatment, the complete response rate was 86.8% in the R arm and 86.3% in the C + R arm. The 3 year disease-free survival was 58.7% in the C + R group and 54.5% in the R group, and the median survival was 39.5% and 47 months respectively (NS). The survival of patients with a complete response at the end of radiotherapy was significantly better in the C + R group (when chemotherapy had been active) than in the R group (p = 0.04). Although radiotherapy was not modified whether patients had initial chemotherapy or not, tolerance was not significantly different between the 2 groups. The data collected in this study indicate that: 1) efficacy of induction chemotherapy is the only available predictive test for long-term results, 2) tolerance to treatment is crucial for optimal chemotherapy delivery, 3) higher dose intensity of chemotherapy in cervical carcinoma is associated with a better tumor reduction, and probably a better survival.