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Biomedical subjects

F Denis

Publications and source records attributed to F Denis.

At least 361 records · Page 20Linked to original sources

Human tumor suppressor p53 and DNA viruses.

Human tumor suppressor protein p53 plays a major role in the cell cycle, orchestrating a number of important genes involved in cell-cycle control and apoptosis, and seems to be one of the most important molecules protecting cells from malignant transformation. Mutations in the p53 gene are observed in about 50% of primary tumors, inducing defective p53 protein no longer capable of binding DNA and of activating transcription. Certain DNA viruses are thought to act in a similar way and may also contribute to the progression of invasive cancer in infected tissue. One of the most effective strategies employed by these viruses is the inhibition of p53 protein by interaction with viral oncoproteins, implying a direct but also an indirect role of these viruses in the impairment of p53 structure and function. This article provides a summary of current knowledge concerning p53 tumor suppressor protein and reviews the different mechanisms adopted by different DNA viruses in undermining p53 function.

Cell Cycle↗

Low HTLV-1 seroprevalence in endemic tropical spastic paraparesis in Ethiopia.

Tropical spastic paraparesis (TSP), a chronic progressive myelopathy, occurs in Ethiopia in epidemic form as neurolathyrism, while the endemic form has remained obscure. We describe the clinical features of 22 patients with TSP and the results of screening for HTLV-1 in these patients, 26 patients with other neurological disorders, 14 patients with leukaemia and 66 blood donors. The major manifestations in the patients with TSP were weakness and spasticity of the lower limbs with upper motor neurone signs and minimal sensory loss and bladder dysfunction. Two patients with TSP (9%), 2 patients with other neurological disorders (7.7%) and one patient with leukaemia and deafness were seropositive for HTLV-1. All the 66 blood donors were seronegative. Our results suggest that HTLV-1 may not play a major role in the pathogenesis of TSP in Ethiopia.

Adolescent↗

Serological evidence for virus related to simian T-lymphotropic retrovirus III in residents of west Africa.

Serological evidence is presented here suggesting that a virus closely related to simian T-lymphotropic virus type III (STLV-III) infects man in Senegal, west Africa, a region where AIDS or AIDS-related diseases have not yet been observed. 25 sera from Senegalese individuals that were positive for antibodies to HTLV-III by enzyme-linked immunosorbent assay were examined for antibodies to HTLV-III and STLV-III by western blotting. Sera from individuals originating from regions where AIDS has been reported, such as the United States and Burundi (central Africa), reacted best with antigens of HTLV-III, although antibodies that cross-reacted with STLV-III p24 were also detected. Conversely, sera originating from Senegalese people reacted better with STLV-III than with HTLV-III. This was exemplified by the absence of reactivity in sera from both monkeys and Senegalese people to p41, an antigen regularly detected by sera from antibody positive individuals originating from central Africa or from the United States. In contrast sera from central Africa or the United States did not react with p32, the putative envelope transmembrane protein of STLV-III that is regularly detected by sera from both monkeys and antibody-positive Senegalese people. These results suggest that certain healthy Senegalese people have been exposed to a virus that is more closely related to STLV-III than to HTLV-III. The existence and study of such virus variants potentially with differential pathogenicity may provide important information for the development of an AIDS virus vaccine.

Africa, Western↗

Anterior chamber concentrations of vancomycin in the irrigating solution at the end of cataract surgery.

PURPOSE: To verify that therapeutic levels of vancomycin were present in the irrigating solution at the end of cataract surgery. SETTING: Service d'ophtalmologie, Université de Limoges, France. METHODS: An irrigating solution that contained 20 mg/L of vancomycin was used in 15 patients having phacoemulsification. Antibiotic concentrations in the phacoemulsification handpiece and in the aqueous humor were measured at the end of surgery. RESULTS: Passage through the phacoemulsifier did not affect antibiotic concentration. In the aqueous humor, after wound closure, the concentration constantly exceeded the minimal inhibitory concentration of the principal gram-positive bacteria responsible for human endophthalmitis. CONCLUSION: Vancomycin added to the irrigating solution used during cataract surgery was found in effective concentrations in the anterior chamber at the end of surgery.

Aged↗

[Prognostic value of the number of involved nodes after neck dissection in oropharyngeal and oral cavity carcinoma].

PURPOSE: To evaluate the relationship between the number of positive nodes and probabilities of locoregional control and survival in patients with invasive squamous cell carcinomas of the oral cavity and oropharynx. MATERIAL AND METHODS: Between 1976 and 1993, we treated with curative intent 183 patients (median age: 56 years; standard deviation: 10 years). Seventy-nine patients (43%) had oropharyngeal primary invasive carcinoma and 104 (57%) had oral cavity (excluding the lip) primary invasive carcinoma. Patients with simultaneous primary lesion or visceral metastases were excluded from the analysis. All the patients had neck dissection with at least six nodes to analyse. One-hundred fifty-nine patients (87%) underwent resection of the primary lesion and 158 (86%) were treated postoperatively with external beam irradiation alone or combined with interstitial implant (median dose: 60 Gy; standard deviation: 10 Gy). Average follow-up was 52 months. RESULTS: The overall 5-year survival rate using the Kaplan-Meier method was 42.6%. The 5-year survival rates were 60.0% when lymph nodes were histologically negative, 39.5% when one lymph node was positive, 28.0% when two lymph nodes were positive and 24.4% when three or more lymph nodes were positive (P = 0.0004). The number of positive nodes did not significantly influence the specific disease-free survival and locoregional control rates. CONCLUSION: Patients with one or more positive neck nodes must have postoperative treatment.

Adult↗

Reconstructive spine surgery in pediatric patients with major loss in vital capacity.

Thirty-two pediatric patients with severe restrictive lung disease identified with vital capacities < 40% of predicted, who had undergone major reconstructive spine surgery, were reviewed. There were 18 boys and 14 girls, the mean age was 13 years (range, 7-17), and the mean vital capacity was 31% of predicted (range, 16-39%). Fifty-four procedures were performed, 13 posterior only, one of which was staged, and 19 anterior and posterior procedures, of which 15 were staged and four were sequential. The incidence of pulmonary complications (pneumonia, reintubation, pneumothorax, respiratory arrest, or the need for tracheostomy) was 19% (six patients), and only three patients required tracheostomy. The surgical and perioperative mortality rate was zero. Patients who had a thoracotomy or a thoracoabdominal approach had a significantly higher number of pulmonary complications. The use of preoperative decreased vital capacity as a measure of inoperability excludes the young patient most in need of surgical intervention. With improved preoperative, intraoperative, and postoperative techniques, careful monitoring, and the cooperation of pediatric pulmonologists and intensivists, reconstructive spine surgery can be performed in the pediatric patient with severe decreased vital capacity with very acceptable morbidity and mortality.

Adolescent↗

The three column spine and its significance in the classification of acute thoracolumbar spinal injuries.

From a retrospective study of 412 thoracolumbar injuries, the author introduces the concept of middle column or middle osteoligamentous complex between the traditionally recognized posterior ligamentous complex and the anterior longitudinal ligament. This middle column is formed by the posterior wall of the vertebral body, the posterior longitudinal ligament and posterior annulus fibrosus. The third column appears crucial, as the mode of its failure correlates both with the type of spinal fracture and with its neurological injury. Spinal injuries were subdivided into minor and major. Minor injuries are represented by fractures of transverse processes, facets, pars interarticularis, and spinous process. Major spinal injuries are classified into four different categories: compression fractures, burst fractures, seat-belt-type injuries, and fracture dislocations. These four well-recognized injuries have been studied carefully in clinical terms as well as on roentgenograms and computerized axial tomograms. They were then subdivided into subtypes demonstrating the very wide spectrums of these four entities. The correlation between the three-column system, the classification, the stability, and the therapeutic indications are presented.

Adolescent↗

Scoliogenic osteoblastoma of the posterior end of the rib. A case report.

True back pain is uncommon in children and adolescents. The authors report a case of scoliosis associated to osteoblastoma in a very unusual site--the rib. This particular location was reviewed in the literature and appears to have an incidence of 0.41% as compared with osteoid osteomas and osteoblastomas in general. The case reported was a 14-year-old girl presenting with a 32 degree scoliosis that reduced to 9 degrees after excision of the lesion. The authors recommend personal review of bone scans as poor communication between the orthopedic surgeon and the isotope expert may make an osteoblastoma be interpreted as a radiographic artifact.

Adolescent↗

Convex growth arrest for progressive congenital scoliosis due to hemivertebrae.

Thirteen patients with progressive congenital scoliosis due to hemivertebrae or hemivertebrae associated with other spinal anomalies were treated by convex anterior and posterior hemiarthrodesis and hemiepiphysiodesis. The average curve prior to operation was 46 degrees, average age was 3 years 6 months, and average followup was 6 years 6 months. One patient failed because of an inadequate length of anterior surgery which was successfully salvaged by further surgery. Twelve patients were successes: Seven had only cessation of the progressive curve, and five had progressive curve improvement greater than or equal to 5 degrees due to the arrested convex and persistent concave growth. This procedure is a valuable treatment modality for selected patients with congenital scoliosis.

Child↗

Syringomyelia and scoliosis: a review of twenty-five pediatric patients.

A retrospective review of 25 patients with scoliosis secondary to syringomyelia was conducted. All patients had large syrinxes, but only 10 patients had abnormal neurologic findings, suggesting that subtle neurologic findings in patients with scoliosis should not be underestimated and supporting liberal use of magnetic resonance imaging (MRI). The results of three approaches to the care of these patients were reviewed: passive observation, bracing, and spinal fusion. Curves progressed > or = 5 degrees in patients aged < 10 years who were observed, but in children aged > 10 years, curves progressed > or = 10 degrees. Curves responded well to bracing, but correction was not maintained out of brace for patients with progressive and/or severe curves. Good corrective was achieved safely during operation.

Adolescent↗

Reinfusion of mediastinal blood in CABG patients: impact on homologous transfusions and rate of re-exploration.

BACKGROUND: Reinfusion of mediastinal shed blood after cardiac surgery has been used in some centers to reduce exposure to homologous blood transfusions. The method has not been widely applied mostly because some studies have failed to demonstrate a significant benefit. METHODS: A group of 675 consecutive patients undergoing first-time, isolated coronary artery bypass surgery (CABG) was studied. Prospective data was collected on the first 375 patients receiving autotransfusion (ATS) of mediastinal shed blood. The charts of 338 patients immediately preceding the institution of the ATS program at our institution (NO ATS group) were retrospectively reviewed. Transfusion of homologous blood products and rate of re-exploration for bleeding were closely monitored. RESULTS: The two groups were identical. The net blood loss was significantly less in the ATS group than in the NO ATS group (1013 +/- 431 cc vs 1371 +/- 631 cc, p < 0.0001). Rate of exploration for postoperative bleeding was 1.5% in the ATS group and 5.0% in the NO ATS group (p < 0.01). In the ATS group, 51.9% of patients were not exposed to any homologous blood product (vs 17.8% in the NO ATS group, p < 0.0001). The ATS patients received on the average 2.9 +/- 7.2 units of blood products versus 6.4 +/- 9.7 units in the NO ATS group (p < 0.0001). CONCLUSION: Reinfusion of mediastinal shed blood significantly reduces exposure to homologous blood transfusions and rate of reexploration. The ATS system reduces the number of re-explorations for coagulopathy-related postoperative hemorrhage.

Blood Loss, Surgical↗

Pentastarch versus albumin in cardiopulmonary bypass prime: impact on blood loss.

BACKGROUND: Albumin is commonly used as a volume expander in cardiopulmonary bypass (CPB) prime. Pentastarch, a low molecular weight hetastarch, may provide similar efficacy at decreased cost but is known to alter coagulation profiles. Infectious concerns forced the temporary withdrawal of albumin in our institution. Therefore we evaluated pentastarch as an alternative with regards to perioperative hemostasis and blood loss. METHODS: One hundred consecutive adult patients undergoing first-time aorto-coronary bypass were given 750 mL of 10% pentastarch (represented as P in calculations) diluted in 1000 mL of Ringer's solution added in their CPB prime. A similar control group of 100 consecutive patients had received 200 mL of 25% albumin (represented as A in calculations) diluted in 1500 mL of Ringer's solution. RESULTS: Postoperative prothrombin time (PT) was slightly higher with pentastarch (P: 14.9 +/- 1.5 seconds, A: 14.2 +/- 1.3 seconds, p = 0.003). Postoperative bleeding was also increased (P: 2337 +/- 1242 mL, A: 1981 +/- 1121 mL, p = 0.034), mostly because of recirculated shed mediastinal blood (P: 834 +/- 499 mL, A: 640 +/- 388, p = 0.002) rather than lost pleural tube blood (P: 1503 +/- 821 mL, A: 1341 +/- 824 mL, p = 0.16). Overall net blood loss (P: 2014 +/- 914 mL, A: 2061 +/- 1015, p = 0.73) was similar. Blood-product transfusion requirements and postoperative daily hematocrits did not differ. CONCLUSION: The diminished coagulability associated with this dose of pentastarch resulted in increased postoperative bleeding. However, with recirculation of shed mediastinal blood, there was no net increase in blood loss. In this setting, pentastarch may serve as a suitable alternative to albumin.

Aged↗