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Biomedical subjects

M Bergoin

Publications and source records attributed to M Bergoin.

At least 37 records · Page 2Linked to original sources
PubMed1996

Pathogenicity of the Aedes albopictus parvovirus (AaPV), a denso-like virus, for Aedes aegypti mosquitoes.

AaPV, a denso-like virus isolated from a C6/36 clone of the Aedes albopictus cell line, proved to be very pathogenic for Aedes aegypti first and third instar larvae following per os infection. The mortality reached 90% in 10 days for larvae infected at the first instar. Several factors, such as temperature, larval density and stage, and duration of contact with infectious particles, influenced infection. The virus titer in females surviving infection at the third larval instar reached 10(8) TCID50. Adult mosquitoes were sensitive to virus inoculation and to cytotransfection by viral DNA. Histological and ultrastructural studies revealed the presence of dense nuclei in almost all of the larval tissues with the exception of the midgut.

Aedes↗
PubMed1996

A titration procedure of the Junonia coenia densovirus and quantitation of transfection by its cloned genomic DNA in four lepidopteran cell lines.

A sensitive and reproducible tissue culture biossay method was developed based on indirect immunofluorescence to titrate virus suspensions of the Junonia coenia densovirus (JcDNV) and to quantify transfections by its cloned genomic DNA. Four lepidopteran cell lines, the SPC-SL 52 from Spodoptera littoralis, the SPC-PL 40 and the SPC-PL 65 cells derived from Spodoptera litura ovaries and hemocytes, respectively, and the SC-LD 135 from Lymantria dispar were compared for their efficiency to support viral replication. The viral titres expressed as TCID50/ml averaged 10(5) for SPC-SL 52, SPC-PL 40 and SC-LD 135 cells, but were above 10(7) for SPC-PL 65 cells. Even with this most sensitive cell line, the rate of infected cells did not exceed 75% and decreased progressively by serial subcultures. Two transfection protocols were used to compare the sensitivity of the same four cell lines to a recombinant plasmid encompassing an infectious sequence of JcDNV genome. SPC-SL 52 cells were found to be the most sensitive, and the lipofection method resulted in about a 5-fold increase compared to the calcium phosphate precipitation protocol. The rescued virions proved to be infectious and the restriction profiles of their DNA were identical to that of wild type virions.

Animals↗
PubMed1996

The choice of treatment for simple bone cysts of the upper third of the femur in children.

A retrospective study of a series is presented of 19 simple cysts of the upper third of the femur in children of a mean age of 7 years. The patients included 4 adolescents and 15 children under the age of 10. Mean recurrence was 6 years. Different treatment methods were utilized: - surgical treatment: curettage-bone grafting with or without osteosynthesis, - intra-cystic corticoid injection, - orthopedic treatment. Cysts may be small with a low lytic potential, in this case intra-cystic corticoid injections are very effective; or bigger in size with a risk of fracture or have already caused a fracture, the treatment is then surgical but should always be combined with osteosynthesis.

Anti-Inflammatory Agents↗
PubMed1996

X-ray transparency interpositions after reduction of traumatic dislocations of the hip in children.

Traumatic dislocations of the hip are much less frequent in children than in adults. If some complications are well known (avascular necrosis of the femoral head, recurrent dislocation), the lateralization of the head by x-ray transparency interposition is less appreciated. We report 4 cases of x-ray transparency interposition in 15 reductions of incomplete traumatic dislocation of the hip. These 4 dislocations were posterior in non-pathological hips, three on the left side and one on the right. Our reductions have been easy and the hips remained stable. However, the post-reduction roentgenogram shows the same unusual enlarged joint space corresponding to the lateralization of the femoral head. Four arthrotomies were performed, tracing a cartilaginous fragment free or fixed to the articular capsule into the femoral joint. We have found a concentric reduction of the hip in 4 cases and enlargement from 1 to 3 mm of the joint space of the hip. After several years, articular function of the four hips is normal, nevertheless, they have shown a coxa valga with a femoral elongation to 10 mm, a coxa magna with an articular space wider than 1 mm, 2 very good concentric reductions of the hip. The lateralization of the head after reduction had to be detected as soon as the first radiographic control because it can cause immediate instability or arthrosis of the hip. Because of the cartilaginous or capsular composition and the size of the interposition, an arthrotomy is performed in front of a radiological enlarging of the space joint, or a loss of parallelism of osteochondral acetabulum bone. Computerized tomography and MRI can reveal the nature, the place of the included fragment, as well as the surgical approach. An arthrogram is not absolutely indispensible. Surgical exploration should avoid degenerative arthrosis after a lateralisation left untreated.

Adolescent↗
PubMed1995

The Melolontha melolontha entomopoxvirus (MmEPV) fusolin is related to the fusolins of lepidopteran EPVs and to the 37K baculovirus glycoprotein.

We have cloned and sequenced a 1.7-kbp DNA fragment of the MmEPV genome encompassing the major polypeptide of the spindle-shaped inclusions gene termed fusolin. The sequence contained a single open reading frame of 1203 nt capable of coding for a polypeptide of 45.8 kDa. The 13 N-terminal amino acid (aa) residues were hydrophobic and could act as a signal peptide. The aa sequence also contained 13 cysteine residues very likely involved in paracrystal formation. This sequence showed significant homologies with the fusolins of two lepidopteran EPVs, the Choristoneura biennis EPV (CbEPV) and the Heliothis armigera EPV, and also with the 37K glycoproteins of Autographa californica and Orgyia pseudotsugata baculoviruses. No homology was found between the MmEPV fusolin and the 100K MmEPV spherulin, nor with the 110K polypeptide of the CbEPV and Amsacta moorei EPV spheroidins. These data were confirmed by Western blot analysis. Transfection of vaccinia-infected mammalian cells with a plasmid encompassing the fusolin sequence plus the upstream regulatory region resulted in transient expression of the gene. This indicated that the vaccinia transcription machinery is able to transcribe the fusolin gene. The fusolin was also expressed in insect cells via a recombinant baculovirus.

Amino Acid Sequence↗
PubMed1995

[Surgical treatment of the rupture of the inferior tendon of the biceps. Apropos of 6 cases].

INTRODUCTION: The purpose of this study is to compare the results of direct reinsertion of the distal bicipital tendon to the bicipital tuberosity, with other methods described in the literature. MATERIAL AND METHOD: This study is based on six athletic patients, all male, ranging in age from 42 to 62 years old. The rupture of the biceps occurred during an unusually violent effort in flexion and forced supination of the arm at a 90 degree of flexion. The surgical procedure which took place between a week and a month after the accident, consisted in a direct reattachment of the detached tendon. RESULTS: No paralysis in the area of the radial nerve occurred. All patients regained normal range of motion of the joints with maintained strength. DISCUSSION: Faced with a recent lesion in a young patient, a reinsertion on the bicipital tuberosity is desirable in order to maximize the strength and movement of the biceps. This simple technique uses a single approach. It does not weaken the bicipital tuberosity nor the muscular function of the biceps.

Adult↗
PubMed1995

[Tenotomy of the psoas muscle in slow reduction of congenital hip dislocations].

PURPOSE OF THE STUDY: The aim of this study was to relate the efficacy of cutting the psoas tendon in case of high congenital hip dislocation treated by slow reduction according to Somerville-Petit. MATERIAL: Twenty psoas tenotomies were realised between 1982 and 1992. The average age was 11 months 15 days old, they were 15 girls and 5 boys. Among them, only 9 patients had never been treated. METHOD: By a short surgical approach close to the lateral lip of Scarpa's triangle, we cut the psoas tendon at the musculotendinous junction doing this suppresses the obstacle that interferes with the femoral head coming down. RESULTS: Results have been evaluated on clinically and especially radiologically. All hips remain stable except one case. A graduated subluxation of the hip occured after removal of the plaster. 18 hips have been revised between the third and fifth year. Clinical results were excellent, on radiological controls 5 hips were considered flawless, 11 satisfying, and 2 were imperfect. Only 2 children have been seen ten years later with excellent clinical and radiological results. DISCUSSION: The hypertrophic psoas tendon interposes between the femoral head and the acetabulum creasing the capsule and the limbus. Cutting tendon of the psoas will decrease the numerous unexplained failures that occured during slow reduction according to Sommerville-Petit method. The use of these surgical techniques may make more outstanding the tenotomies time. CONCLUSION: Tenotomy of the psoas tendon realized by a short surgical approach without any articular effraction, allowed us to obtain complete reduction of the hips dislocation in these 20 patients.

Casts, Surgical↗
PubMed1994

Complete nucleotide sequence and genomic organization of the Aedes albopictus parvovirus (AaPV) pathogenic for Aedes aegypti larvae.

We have cloned the replicative form of the Aedes albopictus parvovirus (AaPV) genome and determined the complete sequence of the viral strand. The sequence is 4176 nucleotides (nt) in length. The first 134 nt at the 3' end and the terminal 182 nt at the 5' end of the viral (minus) strand can both generate by folding and annealing of complementary sequences a typical terminal T-shaped structure although they differ in their sequence. Three large open reading frames (ORFs), each one in a different frame, are present between map units (mu) 8.0 and 87.6 on the complementary (plus) strand. The left, mid (located within the left ORF), and right ORFs have potential coding capacities of 95, 41, and 40 kDa, respectively. Two potential promoters were found upstream from the left and right ORFs, at mu 7.2 and mu 60.0, respectively. Computer search for sequence homologies suggests that the left ORF very likely encodes the nonstructural NS-1 protein since it contains the highly conserved NTP-binding amino acid (aa) domain (GKRN sequence) of all parvoviruses. Comparison with other invertebrate and vertebrate parvoviruses revealed that the AaPV genome shares 77.3% nt sequence homology and between 73 and 78% aa sequence homologies with the Aedes aegypti densonucleosis virus (Aedes DNV). Organization of both genomes was similar except that no potential ORF was found on the minus strand of AaPV. The difference of 167 nt in length between AaPV and Aedes DNV (4009 nt) genomes is due to additional noncoding sequences located between the internal coding region and the terminal palindromes in the AaPV genome. No significant homology was found between AaPV and the two other insect parvoviruses sequenced so far, the Bombyx mori DNV (BmDNV) and the Junonia coenia DNV (JcDNV).

Aedes↗
PubMed1994

Taxonomic studies of Rickettsiella, Rickettsia, and Chlamydia using genomic DNA.

Invertebrate pathogens of the genus Rickettsiella (Order Rickettsiales) undergo a developmental cycle more characteristic of chlamydial organisms (Order Chlamydiales) than of typical rickettsiae. Moreover, among recognized species of Rickettsiella, there is considerable variation in host range and in the ultrastructure and development of the infectious stage, i.e., the elementary body. To begin an analysis of the taxonomic relationships of the invertebrate pathogens belonging to the genus Rickettsiella and of the relationship of these to chlamydiae and other rickettsiae, genomic DNA of representative species was compared with respect to restriction enzyme site polymorphism, DNA-DNA hybridization, G + C ratios, and fine melting profiles. The strains studied included isolates currently classified as Rickettsiella grylli, R. popilliae, R. chironomi, Chlamydia psittaci, C. trachomatis, Coxiella burnetii, and Rickettsia conorii. Reciprocal DNA hybridization studies carried out under high-stringency conditions (65 degrees C) showed homology between R. grylli and R. popilliae isolates but not with the others, including two isolates of R. chironomi from the midge, Chironomus dorsalis, and the scorpion, Buthus occitanus. The R. chironomi isolates shared no detectable homology with each other or with any of the other strains or species. Additionally, no homology was detected between any of the Rickettsiella isolates and the species of Coxiella, Rickettsia, or Chlamydia. Results obtained from the DNA fine melting profiles and G + C ratios corresponded with the results obtained from the DNA hybridization studies. Thus, the present study indicates that, despite similarities in developmental cycles, Rickettsiella and Chlamydia are taxonomically distinct groups appropriately placed in different orders.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Cloning and sequencing of the spherulin gene, the occlusion body major polypeptide of the Melolontha melolontha entomopoxvirus (MmEPV).

In the late stage of infection, virions of the Melolontha melolontha entomopoxvirus (MmEPV) are occluded into cytoplasmic paracrysalline proteinaceous occlusion bodies designated spherules (A. Amargier, C. Vago, G. Meynadier, 1964, Mikroskopie 19, 309-315). We have cloned and sequenced a 4-kpb DNA fragment of the MmEPV genome encompassing the spherule major protein gene named spherulin. The spherulin gene contains an open reading frame able to code for a 942-amino-acid (aa) polypeptide (MW 109 kDa), consistent with a size above 100 kDa determined by SDS-PAGE for purified spherulin. The MmEPV spherulin showed more than 40% as homology with the Amsacta moorei EPV (AmEPV) spheroidin and shared homologies with the partially sequenced Choristoneura biennis EPV (CbEPV) spheroidin, indicating that this biologically important polypeptide is well conserved among EPVs infecting phylogenetically as distant groups of insects as lepidoptera and coleoptera. Western blot analyses confirmed the relationships between the three polypeptides. In contrast, no homology was detected between the MmEPV spherulin and EPV fusolins or vertebrate poxvirus A-type inclusion proteins. The 45 bases upstream from the ATG initiation codon of spherulin shared 60% homology with the vaccinia virus late promoters including the highly conserved TAAATG consensus sequence. Furthermore, the 5' extremity of the spherulin mRNA consisted of a poly(A) tract of about 20 nucleotides just upstream from the AUG translational initiation codon. These are characteristic features of vertebrate poxvirus late mRNAs suggesting similar modalities of gene expression for vertebrate and insect poxvirus genomes.

Amino Acid Sequence↗
PubMed1994

Structure, restriction map and infectivity of the genomic and replicative forms of AaPV DNA.

We have characterized the genomic and replicative form (RF) DNA of the Aedes albopictus Parvovirus (AaPV), a virus isolated from a chronically infected C6/36 clone of Aedes albopictus cell line [22]. The genome of AaPV virions is a single-stranded linear DNA molecule approximately 4.2 kb in length, essentially (about 90%) encapsidated as minus strand. A restriction map of the RF DNA isolated from infected C6/36 cells was established. Among the 23 restriction enzymes tested, 14 cleaved the AaPV RF DNA and 30 restriction sites were mapped and oriented with respect to the viral genomic DNA. Both viral and RF DNAs were found infectious when transfected to virus-free C6/36 cells. The asymmetrical encapsidation of the viral genome is a property common to most vertebrate autonomous parvoviruses but rather unusual among densoviruses. Both by its small size, the asymmetrical mode of encapsidation and the restriction map, the AaPV genome resembles that of the Aedes Densonucleosis virus [1].

Aedes↗
PubMed1993

[Treatment of idiopathic scoliosis in children].

This is an update on the surgical and orthopedic management of scoliosis in children. After a review of the biomechanical factors underlying the scoliotic deformity in the three dimensions, methods and indications of conservative treatment combining physiotherapy and full-time or part-time bracing are discussed. Development of new segmental spinal instrumentation devices has modified the surgical treatment of scoliosis by allowing three-dimensional correction of deformities and obviating the need for postoperative immobilization in a cast or corset. Results of conservative treatment are analyzed in an original series of 56 children with progressive scoliosis treated when the angulation was still under 30 degrees. Mean follow-up since the end of treatment is 14 years. Results show that proper conservative treatment arrests progression and modifies the natural history of scoliosis. Outcome after surgical treatment is analyzed in an original and recent series composed of the 50 first children who had posterior surgery with the new Cotrel-Dubousset instrumentation. Results of anterior surgery (V.D.S. instrumentation), which is still indicated in some cases, are analyzed in an older series of 18 cases. When the deformities are too severe to allow conservative treatment, short segment fusion effectively corrects the scoliosis and reliably provides good cosmetic and functional results.

Adolescent↗
PubMed1992

The densovirus of Junonia coenia (Jc DNV) as an insect cell expression vector.

An infectious genome of the Junonia coenia densovirus (Jc DNV) has been recently cloned and sequenced. We investigated the ability of this cloned genome to be used as expression vector by inserting the lacZ gene of Escherichia coli as fusion gene in the major open reading frame (ORF 1) of the viral sequence. The resulting recombinant plasmid designated pBRJlac Z was transfected into insect SPC-SL 52 cells and the expression of beta-galactosidase (beta-gal) was detected qualitatively or quantitatively by using Xgal or ONPG as chromogenic substrates. Western blot analysis revealed that beta-gal was expressed as chimeric capsid-beta-gal polypeptides. This provided evidence that ORF1 codes for structural polypeptides which share a common C-terminal sequence. Construction of plasmids with alterations or deletions in ORF2, 3 or 4, allowed us to implicate nonstructural (NS) functions in viral DNA replication. Deletions in inverted terminal repeats or in NS functions did not abolish expression of capsid polypeptides but reduced it dramatically. Encapsidation of Jlac Z recombinant genome was achieved by trans-complementation with plasmids bearing intact structural and nonstructural functions. Detection of a beta-gal activity in SPC-SL 52 cells following several subcultures post-transfection suggests that Jlac Z recombinant genome could be maintained in an integrative or episomal state.

Animals↗
PubMed1992

Complete nucleotide sequence of the cloned infectious genome of Junonia coenia densovirus reveals an organization unique among parvoviruses.

We previously constructed a recombinant plasmid, pBRJ, encompassing an infectious Junonia coenia densovirus (JcDNV) genome (M. Jourdan et al. (1990). Virology 179, 403-409). We report here the complete viral sequence of pBRJ. The genome, 5908 nucleotides (nt) long, consists of an internal unique sequence flanked by long (517 nt) inverted terminal repeats. The first 96 bases of one extremity can fold into a typical Y-shaped hairpin structure. The opposite extremity is incomplete, lacking 88 nt. These terminal structures, similar to those of dependoviruses, human parvovirus B19 and Bombyx mori densovirus (BmDNV), strongly suggest a common mechanism of DNA replication for these parvoviruses. JcDNV genomic organization is unique among parvoviruses in that coding sequences are evenly distributed in the 5' half of both strands. On one strand, the major open reading frame (ORF1) encodes the four structural proteins. On the complementary strand, ORF2, ORF3 (included in ORF2), and ORF4 probably encode nonstructural proteins. JcDNV genome has little DNA homology with vertebrate parvoviruses and surprisingly even less with the two densoviruses presently sequenced. ORF1 contains the highly conserved PGY and G-rich regions and ORF2 the NTP-binding domain common to most structural and to all nonstructural vertebrate parvoviral ORFs, respectively. The single homology between JcDNV and BmDNV is unexpectedly located in JcDNV NTP-binding domain and BmDNV ORF2 assumed to encode structural polypeptides. Only a weak homology exists between JcDNV and Aedes DNV in their NTP-binding domain.

Amino Acid Sequence↗
PubMed1990

Cloning of the genome of a densovirus and rescue of infectious virions from recombinant plasmid in the insect host Spodoptera littoralis.

We have cloned an infectious genome of the Junonia coenia densonucleosis virus (JcDNV) into the bacterial plasmid pBR322. The viral genome could be rescued from the recombinant plasmid pBRJ by transfection of pBRJ DNA to sensitive Spodoptera littoralis larvae. pBRJ DNA produced a typical viral infection and a comparable percentage of larvae became infected following inoculation of equivalent amounts of purified virion DNA or cloned viral DNA. Virions extracted from transfected larvae were indistinguishable from wild-type (wt) virions with regard to their biophysical and biological properties. In particular, rescued virions were as infectious as wt virions and showed identical restriction profiles of their genome. In contrast, subcloning of JcDNV DNA deleted at both extremities of a sequence of ca 250 or ca 100 bp resulted in the inability of the recombinant plasmids to initiate a viral infection. These data suggest that, as for vertebrate parvoviruses, the inverted terminal repeats display essential functions in the rescue process and replicative cycle of densoviruses. This is the first report of the molecular cloning of the infectious genome from an insect parvovirus, and more generally from an invertebrate virus. pBRJ should provide an efficient tool to further define the organization of the JcDNV genome and compare it to other parvoviruses.

Animals↗
PubMed1990

Restriction maps and sequence homologies of two densovirus genomes.

The genomes of Junonia coenia densonucleosis virus (JcDNV) and Galleria mellonella densonucleosis virus (GmDNV) were analysed by restriction endonuclease analysis and Southern blot hybridization. A total of 37 and 33 restriction sites were mapped on JcDNV and GmDNV DNA, respectively. BglI, HaeII and BstEII were site-specific for JcDNV DNA, and BglII and ClaI for GmDNV DNA. The two genomes had nearly identical maps for several restriction endonucleases and Southern blot hybridization using a total genomic JcDNV probe indicated extensive DNA sequence homologies spanning the entire length of the two genomes. Symmetrical cleavage sites, mapping at the extremities of both genomes, confirmed the presence of inverted terminal repeats of at least 420 to 440 bases in length.

Animals↗
PubMed1989

Pulsed-field gel electrophoresis determination of the genome size of obligate intracellular bacteria belonging to the genera Chlamydia, Rickettsiella, and Porochlamydia.

The chromosome length of obligate intracellular procaryotes was determined by pulsed-field gel electrophoresis of intact or NotI- and SfiI-restricted genomes. Sizes averaged 2,100, 1,720, 1,550, 2,650, and 1,450 kilobases for Rickettsiella grylli, Rickettsiella melolonthae, Porochlamydia buthi, Porochlamydia chironomi, and Chlamydia psittaci and Chlamydia trachomatis, respectively. An SfiI restriction map of the R. melolonthae genome was derived.

Chlamydia↗