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Biomedical subjects

F Denis

Publications and source records attributed to F Denis.

At least 127 records · Page 7Linked to original sources
PubMed1994

Anterior surgery in scoliosis.

Anterior approaches for scoliosis are now frequent. Versatility in exposure is such that any segment may be approached from either side without significant difficulty or morbidity. Anterior spine surgery is an addition to the modern armamentarium by improving correction, insuring fusions, and allowing better alignment of the scoliotic spine. In the 1990s, scoliosis patients are beneficiaries of innovators of safe and sound anterior spine surgical practice.

Adolescent↗
PubMed1994

The King V curve pattern. Its analysis and surgical treatment.

The importance of the double thoracic (King V) curve lies in the need for the patient to have a balanced connection. None of us wishes to produce a decompensated trunk patient as the result of our surgical efforts. To recognize the curve pattern, one should read carefully the classic article by King et al. To select the proper technique of management, one should read the new work by Lee et al, which discusses subtleties not described in the previous article. At our center, we favor balanced correction so that the result is two curves of equal value, level shoulders, absence of an ugly trapezius area prominence, a vertical and well-centered torso, and a normal sagittal contour. Over-correction of the right thoracic curve must be avoided.

Adolescent↗
PubMed1993

Analysis of the upper thoracic curve in surgically treated idiopathic scoliosis. A new concept of the double thoracic curve pattern.

The authors reviewed 246 idiopathic scoliosis patients with the upper thoracic curve of more than 20 degrees. Group I (138 patients) had positive T1 tilt and a spinal fusion which was extended over both the upper and lower thoracic curve with the diagnosis of double thoracic curve. Group II (43 patients) had positive T1 tilt, but the fusion was limited to the lower thoracic curve. Group III (65 patients) had negative or neutral T1 tilt and the fusion was limited to the lower thoracic curve. The average age at operation was 15.9 years (range, 11.2-35 years) and the average length of follow-up was 4.8 years (range, 2-29.5 years). Positive T1 tilt did not correlate well with left shoulder elevation contrary to previous reports. The upper thoracic curve was more rigid than the lower curve in all groups and the lumbar curve was significantly more flexible than the upper and lower thoracic curves in all groups (P < 0.05). No significant difference in the flexibility of the upper thoracic curve was found between the groups regardless of the direction of T1 tilt. When only the lower curve was fused (groups II and III), progression of the upper thoracic curve was less than 5 degrees, and spontaneous correction of the unfused upper curve occurred in the majority of the cases following the supine bending study. Correction and fusion on the lower curve (groups II and III) aggravated shoulder imbalance of all patients with left shoulder elevation. Based on the findings of this study, the authors proposed that the diagnosis of idiopathic double thoracic patterns should be limited to those patterns which require fusion of both the upper and lower curves. This pattern of idiopathic scoliosis includes double thoracic curves with left shoulder elevation and/or a rigid upper thoracic curve.

Adolescent↗
PubMed1993

Lack of association between peripheral neuropathy and HTLV-I infection in west Africa. Epidemiological, serological and nerve biopsy study.

Patients (n = 1166) with various neurological disorders hospitalized in Dakar, Abidjan, Lomé and Ouagadougou were examined prospectively over a 42-month period. Seropositivity for HTLV-I alone was found to be 1.8%, which is comparable to that estimated for the general population in Africa. Eighteen of the patients with TSP and only 5 with PN were HTLV-I positive, but co-infections were found in 30-40% of cases. Discrete and unspecific lesions were observed on light and electron microscopic examination of peripheral nerve biopsies from 11 patients. Since spastic paraparesis emerges as the disorder containing the largest number of HTLV-I-positive individuals, it may be premature to conclude that HTLV-I is a causal agent in PN. Nevertheless, their rarity and the frequency of retroviral co-infections distinguish these cases of African HTLV-I-associated myelopathy from comparable cases observed in other parts of the world.

Adolescent↗
PubMed1993

HTLV-1 antibody class and subclass distribution in African TSP and control populations.

The humoral immune responses in 44 sera from HTLV-1 seropositive African subjects were compared. The sample population was composed of 12 patients with HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), 12 patients with other neurological conditions and 20 asymptomatic carriers. Samples HTLV-1 antigens were tested against all immunoglobulin classes and IgG subclasses, using the Western blot technique with polyclonal and monoclonal antibodies. Whilst IgG reacted with gag, env and tax products for the three groups studied, IgM and IgA were found to react more frequently with HTLV-1 in HAM/TSP patients. For these patients, IgM and IgA were particularly directed against tax and env proteins. Among IgG subclasses, IgG1 was most sensitive to gag, env and tax products reacting in similar proportions in all three groups. IgG2 and IgG4 were apparently not involved. IgG3 was most responsive in HAM/TSP patients. These data are similar to those observed in AIDS patients, LAS and HIV asymptomatic carriers and emphasize the role of HTLV-1 in HAM/TSP.

Acquired Immunodeficiency Syndrome↗
PubMed1993

High antigenic cross-reactivity of the V3 consensus sequences of HIV-1 gp120.

The principal neutralization determinant (PND) of the human immunodeficiency virus type 1 (HIV-1) is located within the variable V3 region of the external envelope protein gp120. Although it is recognized that V3 sequences induce antibody response with restricted neutralization activity in vitro, we observed that the V3 consensus sequences representing North American/European and African isolates were highly cross-reactive, binding 94 and 77%, respectively, of sera collected from HIV-1 individuals originating from various parts of the world. Even HIV-1-positive sera from some East African residents, infected by strains whose V3 loop sequences are undoubtedly distinct from the North American/European consensus V3 loop sequence, reacted better to the V3 North American/European consensus peptide than to African-specific V3 sequences. Results indicate that the V3 consensus sequences represent the best candidates for optimal cross-reactivity with a wide variety of strains. Furthermore, using immunoassays for antibodies to prototype-specific V3 sequences, it is shown that HIV-1 strains related to the MN group are prevalent in West Africa, indicating either a West African origin of the MN-related viruses or more probably an introduction of this group of viruses through European/North American contacts.

Africa↗
PubMed1993

Characterization of dual HIV-1 and HIV-2 serological profiles by polymerase chain reaction.

OBJECTIVE: To evaluate the frequency of dual HIV-1 and HIV-2 DNA sequences in patients with dual serological profiles. DESIGN: We tested 40 samples from AIDS patients living in Abidjan, Côte d'Ivoire. METHODS: Dual serological reactivity was determined by double Western blot and two enzyme-linked immunosorbent assays with recombinant proteins and synthetic peptides as antigens. The Western blot was considered to show dual reactivity when sera reacted with at least two glycoproteins and one core protein of each virus. HIV DNA sequences were detected by hybridization to radiolabelled probes of polymerase chain reaction (PCR) products amplified using specific primers. RESULTS: Both HIV-1 and HIV-2 DNA sequences were detected in four out of 11 samples with a dual serological profile and in four out of 24 samples with anti-HIV-1 antibodies only. CONCLUSION: These results show that dual HIV-1 and HIV-2 serological profiles are not always due to infection by both viruses, and emphasize the need for a combination of serological and PCR assays for the appraisal of these viral infections.

AIDS Serodiagnosis↗
PubMed1993

Discrimination between human T-cell lymphotropic virus type I and II (HTLV-I and HTLV-II) infections by using synthetic peptides representing an immunodominant region of the core protein (p19) of HTLV-I and HTLV-II.

We describe enzyme immunoassays that use synthetic oligopeptides to discriminate serologically between human T-cell lymphotropic virus type I and II (HTLV-I and HTLV-II) infections. The peptides represented 20-amino acid segments between residues 111 and 130 (MA1) and residues 116 and 135 (MA2) of the p19 gag proteins of HTLV-I and HTLV-II, respectively. The assays were sensitive since 69 of 74 HTLV-positive sera were reactive to at least one of the two matrix (MA) peptides (sensitivity, 93.2%). By using the ratio of the optical density of MA1 to the optical density of MA2, which represents for every serum sample the ratio between the absorbance value obtained in the MA1 assay and the absorbance value obtained in the MA2 assay, 59 of the 69 reactive serum samples were clearly and easily typed as positive for either antibody to HTLV-I or antibody to HTLV-II. Eight of the 10 remaining reactive serum samples were analyzed further by an inhibition procedure, and their type specificities were then clearly identifiable. Therefore, the results indicate that all MA-reactive sera were serologically distinguished by our peptide assays.

Amino Acid Sequence↗
PubMed1993

Prevalence of hepatitis C virus antibodies in the general population and in selected groups of patients in Limoges, France.

In this study of hepatitis C virus (HCV) infection prevalence in France, the prevalence of antibodies to HCV (as tested by second generation ELISA, with RIBA-2 confirmation in ELISA 2 positive samples) was found to be low (0.3%) in the healthy general population. HCV infection prevalence increased in the general population in association with African or Asian origin and risk factors such as bisexuality, previous history of transfusion, and intravenous drug abuse. The prevalence of anti-HCV infection was also higher in specific patient groups infected with HIV or a history of transfusion or haemodialysis.

Female↗
PubMed1993

A survey of antibodies to hepatitis C virus in Ethiopia.

Antibodies to hepatitis C virus (HCV) were measured in 1,580 Ethiopian subjects representing urban and rural populations. Sera found positive by a repeated second generation enzyme immunoassay (EIA) were subjected to three additional confirmatory tests. The overall confirmed seroprevalence was 2.0%. Less than 1% were confirmed to be seropositive in rural communities, with 1.4% positive among blood donors, 1.6% positive among patients with dermatologic disorders, 3.6% among leprosy patients, and 6.0% among patients attending a University Hospital clinic for neurologic disorders. The patients in the groups with leprosy and neurologic disorders have most likely been in ill health for many years and have sought relief by traditional healers or treatment at poorly equipped clinics. This group of patients demonstrated a high prevalence of antibodies to HCV. In Ethiopia, especially in small clinics, there is a shortage of syringes and needles and they have to be reused many times often with inadequate sterilization. Therefore, these syringes and needles may be contaminated, thus being a risk factor for HCV and HIV infection.

Adolescent↗
PubMed1993

[Listeria monocytogenes femoral aneurysm].

Secondary infection of arterial aneurysms being a constantly possible complication, the bacteriological examination of peroperative specimens appears to be appropriate. Among responsible organisms, the presence of Listeria monocytogenes is very rare since only 13 cases have been reported in the literature. It is for this reason that it was felt to be of interest to report a new, entirely similar case of femoral aneurysm.

Aged↗
PubMed1992

A versatile shuttle cosmid vector for use in Escherichia coli and actinomycetes.

A shuttle cosmid vector has been constructed for Escherichia coli and actinomycetes. This vector, pFD666, utilizes the origin of replication (ori) of the broad-host-range plasmid, pJV1, from Streptomyces phaeochromogenes, for replication in actinomycetes and is compatible with vectors derived from pIJ101. The pFD666 vector employs the neomycin phosphotransferase-encoding gene (neo) from transposon Tn5 as the selective marker. To achieve this, the native promoter of neo was replaced by one optimized for expression in both hosts. The polylinker used for cloning has nine unique sites flanked by the promoters for T7 and SP6 RNA polymerase for the production of specific RNA probes. Terminators on both sides of the polylinker protect the vector from transcription originating from cloned inserts. An M13 ori allows the production of single-stranded DNA.

Actinomycetales↗
PubMed1992

Shear fracture-dislocations of the thoracic and lumbar spine associated with forceful hyperextension (lumberjack paraplegia).

Twelve patients sustained a shear fracture-dislocation of their thoracic or lumbar spines by a hyperextension mechanism of injury. Ten male and two female patients were injured; their average age was 29 years (range, 22 months to 56 years). Ten fracture-dislocations occurred in the thoracic spine, one at the thoracolumbar junction, and one in the lumbar spine. Eleven patients had complete paraplegia, and one had incomplete paraplegia at the time of injury. Dural tears were found in six of the patients. Eleven patients were treated by posterior spinal fusion with instrumentation, and one was treated with a brace. Three patients were treated with Harrington distraction rods alone, six had Harrington distraction rods supplemented with a midline Harrington compression rod or interspinous wiring, and two were treated with Cotrel-Dubousset instrumentation. No patient was lost to follow-up. The average length of follow-up was 3.5 years (range, 1-9 years). Six of the patients treated with Cotrel-Dubousset instrumentation or Harrington distraction rods supplemented with either a midline compression rod or interspinous wiring healed anatomically; two patients developed pseudarthroses. None of the patients treated with Harrington distraction rods alone healed in an anatomic position. The use of Harrington distraction rods alone was associated with overdistraction and nonanatomic alignment of the spine. The disruption of the anterior stabilizing structures of the spine associated with hyperextension injuries necessitates the use of instrumentation that can stabilize the spine and prevent overdistraction. This injury can be successfully treated with Cotrel-Dubousset or Harrington distraction rods supplemented with either a midline compression rod or interspinous wiring.

Adult↗