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Biomedical subjects

P Duval

Publications and source records attributed to P Duval.

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

Prevalence of enteropathogenic, enteroaggregative, and diffusely adherent Escherichia coli among isolates from children with diarrhea in new Caledonia.

The clinical significance of HEp-2-adherent Escherichia coli in children with diarrhea in New Caledonia has been examined by testing isolates from stools of ill children and matched controls in a HEp-2 cell binding assay and by hybridizing the same clones with DNA probes identifying the enteropathogenic (EPEC), enteroaggregative (EAggEC), and diffusely adherent (DAEC) E. coli. From the 100 patient-control pairs, 35 HEp-2-adherent strains were isolated; 24 were identified as the only pathogen in stools of ill children, and 11 were from controls. EPEC strains were significantly associated with diarrheal disease (P < .008) in children in the first 2 years of life. For the DAEC strains, the difference in rate of isolation between patients and controls was significant only when the presence of afa/daa sequences in the strains was considered (P = .03, Fisher's exact test). The afa/daa-positive DAEC isolates were characterized from children 2-6 years old. EAggEC strains were isolated equally in patients and controls.

Bacterial Adhesion↗
PubMed1995

Norepinephrine but not epinephrine stimulates the release of corticotropin-releasing factor from in vitro superfused rat hypothalamus.

To clarify the controversy concerning the role of catecholaminergic systems in regulating hypothalamic corticotropin-releasing factor (CRF) secretion, we assessed the direct effects of norepinephrine and epinephrine, alone and in association with mixed alpha and beta antagonists on hypothalamic CRF secretion. An in vitro rat mediobasal hypothalamus perifusion system was used, in which CRF secretion from a single explant was evaluated by a specific radioimmunoassay. We found that norepinephrine stimulated CRF secretion, with peak effects at 10(-8) M concentration, whereas epinephrine had no effect on CRF secretion. The effect of norepinephrine was antagonised by the mixed alpha antagonist phentolamine and by the mixed beta antagonist propranolol. We conclude that norepinephrine, but not epinephrine, stimulate hypothamic CRF secretion via alpha and beta receptors. The data support the idea that the central noradrenergic systems are excitatory upon CRF-41 secretion when acting directly at the hypothalamic level.

Adrenergic alpha-Agonists↗
PubMed1994

[Leprosy in New Caledonia from 1983 to 1992. Histopathological and epidemiological data].

New Caledonia is a South Pacific Island inhabited by more than 170,000 people: most of them are melanesians or europeans. Multidrug therapy for Hansen disease has been employed since 1983; so we made an epidemiologic and histopathologic study of the new cases diagnosed for 10 years, from 1983 to 1992. Local (clinical, histological, microbiological and immunological) means of diagnosis are described. In New Caledonia, the endemic level is lower than in the small neighbouring Pacific islands but there is still a native reservoir of Mycobacterium leprae with 40% multibacillary types. Nearly half of the new cases are less than 25 years old. They are often male melanesians. The diagnosis of indeterminate forms is debated when there is no acid-fast bacillus. Border-line forms are rare. Tuberculoid leprosy poses many differential diagnosis problems. Despite available multidrug therapy, one cannot yet consider that the incidence is decreasing significantly.

Adult↗
PubMed1994

[Validation of rheological properties of fibrin glue: Biocol-Human Thrombin].

Rheological properties of one of the main fibrin glues, "Biocol-Thrombine Humaine", prepared by the Regional Blood Transfusion Center of Lille (France) were measured with a CSL controlled stress rheometer using cone-plates and parallel plates. The parameters followed were the dynamic viscosity of the fibrinogen concentrate, the gelification time, the breaking point in a destructive test and the development of elasticity of the fibrin clots according to time or frequency. The results showed that the fibrinogen concentrate of "Biocol-Thrombine Humaine" has a flow curve near that of Newtonian flow, and that its dynamic viscosity at 20 degrees C is about 100 mPa.s. The gelification time of the fibrinogen-thrombin mixture is very short (under 10 seconds). The breaking point is high, showing a great strength of the fibrin clots. The development of elasticity after mixing is very quick. It is also independent of the frequency shearing. The validation of these rheological tests provides data supporting their use in the assessment of the physical properties of fibrin glue in place of the currently used test based on the gluing of mouse skin.

Fibrin Tissue Adhesive↗
PubMed1993

A static dynamometer measuring multidirectional torques exerted simultaneously at the hip and knee.

The function of a static dynamometer measuring torques exerted simultaneously in the different anatomical planes of the hip (flexion-extension, abduction-adduction and internal-external rotation) and knee (flexion-extension) is described. Muscular torques were calculated in real time using a desktop computer from measurements of orthogonal forces applied at two locations and the lever arm values measured in each subject. The reliability of the force transducers was explored by examining their output, using calibrated weights, on three different days. The results were identical over this period of time, indicating that the transducers are highly reliable. A mechanical simulator of a lower limb was constructed to generate specific or combined torques of known values at the hip and knee. The torques measured by the dynamometer were found to be highly concordant with the known torques applied by the simulator, indicating that the torque measurements were valid. The usefulness of the dynamometer is demonstrated by evaluating the activity of the rectus femoris and biceps femoris muscles during static efforts exerted in various directions at the hip. In addition, the mechanical action of biarticular muscles at the hip was evaluated by quantification of hip torques during efforts exerted at the knee. From these results, it has been concluded that the present biarticular and multidirectional dynamometer is a valid, reliable and precise instrument that may prove to be useful in evaluating the muscular function of the lower limb.

Biophysics↗
PubMed1992

Foetal radiation dose in radiotherapy for breast cancer.

Management of breast cancer during pregnancy is complicated by the high risks of abortion and foetal malformation from the use of radiotherapy and chemotherapy. A case of breast cancer during pregnancy, treated with radiotherapy, and the estimated foetal dose is reported.

Adult↗
PubMed1992

Spinal cord compression in prostate cancer. A 10-year experience.

Of 478 patients treated at a single institution for prostate cancer, 29 developed spinal cord or cauda equina compression. In 5 patients, spinal cord compression was the first evidence of malignancy. Clinical features were predominantly pain, weakness, sensory and sphincter disturbance. The median duration of symptoms was 2 weeks, although the diagnosis was made rapidly at presentation. Clinical diagnosis correlated well with myelographic findings. Only 1 patient suffered neurological deterioration as a consequence of myelography. The functional outcome was dependent on the ability to walk prior to treatment. The median survival in those who were bedridden following treatment was 6 weeks (range 3.5-13) and 21 weeks (range 7-110+) in those who were ambulant following therapy.

Cauda Equina↗
PubMed1991

Static dynamometer for the measurement of multidirectional forces exerted by the thumb.

The functioning of a static dynamometer designed to measure simultaneous forces exerted by the thumb in the vertical and horizontal axes is described. The analysis of the output signals by a desktop computer program provides information regarding the forces generated in eight directions covering a plane transverse to the thumb by 45 degree increments. In 12 normal female subjects, the maximum voluntary torques exerted at the trapezo-metacarpal joint of the thumb were examined and the muscle activation patterns of the interosseus, flexor pollicis brevis and adductor pollicis brevis muscles were recorded in one subject. Torques and muscle activation patterns were depicted using polar plots. Dynamometric data indicate that strength varies with direction and that higher torques are obtained in directions that bring the thumb towards the palm, i.e. flexion, adduction, combined flexion-adduction and extension-adduction. Patterns of muscle activity vary according to the direction evaluated suggesting that strength depends on the number of activated muscles as well as the relative force contribution of each muscle.

Calibration↗
PubMed1991

Limited small cell lung cancer: the effect of radiotherapy on local control following response to chemotherapy.

The survival and rate of chest infield relapse was examined in 48 patients with limited disease small cell lung cancer (LSCLC) who had achieved complete (CR) or partial response (PR) following three courses of chemotherapy. During 1985-1986 chemotherapy consisted of carboplatin and etoposide and during 1986-1987, of etoposide, carboplatin, cyclophosphamide, and vincristine (ECCO). After three courses of chemotherapy, chest irradiation (50 Gy in 25 fractions over 5 weeks) was given to encompass the original tumor volume. Complete responders were also given prophylactic cranial irradiation, 30 Gy in 10 fractions over 2 weeks. Overall median survival of all patients receiving chest irradiation was 17 months from commencement of radiotherapy. The infield relapse-free survival at 24 months was 49% (95% confidence interval: 32-66%). Patients who had only achieved a PR at the time of irradiation were more likely to relapse in the chest than complete responders (p = 0.09). We conclude that local relapse remains a major cause of failure in patients with LSCLC in spite of sequential high dose radiotherapy given to patients who have responded to chemotherapy.

Adult↗
PubMed1991

[Massive necrotizing adenitis complicating a disseminated herpes simplex virus 2 infection in chronic lymphoid leukemia].

We report a case of a 68 years old male patient treated for chronic lymphocytic leukaemia, presenting a right inguino-crural tender lymphadenopathy with periadenitis. The histologic changes associated with adenitis were large foci of necrosis with regular crown of epithelioid cells, without giant cell. The presence of Herpes simplex virus 2 was confirmed by immunohistochemistry and culture. Occurrence, physiopathology, clinical and histological aspects of Herpes simplex lymphadenitis in patients with haematologic disorders, are discussed.

Aged↗
PubMed1990

Study of soft tissue ingrowth into canine porous coated femoral implants designed for osteosarcomas management.

The objective of this project was to characterize soft tissue bonding to porous coated implants such as those that would be used for resection-reconstruction of osteosarcoma cases. We were interested in determining conditions which would provide both mechanical attachment of the implant to the surrounding tissue and produce a vascularized interface. In a bilateral canine implant model, both femoral mid-shafts were replaced with a porous coated cobalt-chrome segmental implant fabricated with average pore sizes of 300 microns or 900 microns. Twelve implants, six of each pore size, were used in six dogs. Two dogs were sacrificed at 2, 4, and 6 months after implantation. The soft tissue-implant interface was characterized mechanically with peel tests and histologically using light microscopy and immunohistochemistry. At all periods, a nonvascularized fibrous membrane surrounded the smaller pore size implants, without ingrowth or mechanical bonding. In contrast, a vascularized membrane developed within and around the larger pore size implants; the attachment strength increasing with implantation time. The vascularity increased in size and quantity with time. This study demonstrates the feasibility of obtaining vascularized soft tissue attachment to tumor replacement implants with appropriate porous coated implant design.

Animals↗
PubMed1989

Extraovarian peritoneal serous papillary carcinoma. A clinicopathologic study of 31 cases.

The rate and clinical features of patients admitted to King George V Hospital with extraovarian peritoneal serous papillary carcinoma during a 9-year period were reviewed. In this time, 31 of 236 (13%) patients with an initial diagnosis of invasive serous ovarian carcinoma fulfilled the surgicopathologic criteria for this entity. All patients had disseminated tumor equivalent to ovarian Stage III and IV disease (International Federation of Gynecology and Obstetrics [FIGO]) and with predominantly high-grade neoplasms. They were managed by surgical exploration, tumor debulking where possible, and postoperative chemotherapy. A comparison with a contemporaneous series of 139 patients with primary epithelial ovarian carcinoma matched for stage and grade of disease and managed similarly showed no difference in actuarial survival. The median survival times were 11.3 months for patients with extraovarian serous papillary carcinomas and 13.5 months for patients with equivalent primary ovarian neoplasms. The features of the disease and the treatment regimens used are discussed.

Adult↗
PubMed1989

A comparative study of proliferating (borderline) and invasive epithelial ovarian tumours in young women.

A series of 18 patients with proliferating or borderline ovarian tumours and 18 with invasive ovarian tumours is discussed. Proliferating tumours occurred at a younger mean age than invasive disease, and presented at an earlier stage, both contributing factors to their more favourable outlook. Histopathological assessment revealed that the majority of both proliferating and invasive tumours were of serous origin. Mucinous cell type occurred less often as did the endometrioid and clear cell types. The management of the proliferating tumours involved 'radical' surgical procedures in 11 of 18 (61.6%) patients. Only 7 patients (38.8%) had conservative surgical procedures performed. Six patients (33%) had adjuvant chemotherapy while 2 (11%) also underwent abdominopelvic irradiation. All patients with invasive disease had radical surgery and adjuvant chemotherapy and 2 also received abdominopelvic irradiation. The fact that epithelial malignancies of the ovary do occur in younger women needs to be remembered by gynaecologists contemplating surgical procedures on younger patients with adnexal masses. Proliferating or borderline tumours tend to occur more frequently in the younger age groups, and contrary to the implication of their name, they are associated with significant morbidity and mortality.

Adolescent↗
PubMed1988

Pre-emptive (neo-adjuvant) chemotherapy prior to radical radiotherapy for fit septuagenarians with bladder cancer: age itself is not a contra-indication.

Advanced age has often been cited as a contra-indication to the use of cytotoxic chemotherapy or aggressive combined treatment regimens. Fifteen patients, aged between 70 and 79 years (mean 73.1), have been treated for high grade, invasive bladder cancer using neoadjuvant intravenous cisplatin (80-100 mg/m2) plus radical radiotherapy (60 Gy in 6 weeks). Objective response was achieved in 14 patients. The median survival was 22 months, with 6 patients surviving 3 years or longer. Acute and late side effects were not excessive (no cases of W.H.O. grade IV toxicity), as demonstrated by clinical examination and the use of questionnaires (including linear analogue self-assessment scales) to assess quality of life. This aggressive treatment programme can achieve a high remission rate and prolonged survival in elderly patients with high risk bladder cancer without causing excessive morbidity.

Acute Disease↗