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Biomedical subjects

P Vincent

Publications and source records attributed to P Vincent.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Stage III non-small cell lung cancers: prospects of concomitant radiochemotherapy].

The prognosis of stage III non small cell lung cancer is reportedly poor, particularly in patients with mediastinal lymph node involvement. These patients may be either good surgical candidates, marginally resectable, or inoperable for technical or medical reasons, but, in any case, surgery and/or radiotherapy are curative in only a minority of them. The high incidence of early distant failures underscores the need for early and effective systemic therapy in association with local treatment, since occult metastatic disease is present in most patients at the time of diagnosis. Recent phase III trials have demonstrated significant benefit to induction chemotherapy prior to irradiation or surgery in reducing the distant metastasis rate. However, poor local control remains a major issue in these locally advanced tumors. In patients with inoperable disease, the concomitant use of chemotherapy along with radiotherapy substantially improves local control. For operable patients, induction chemotherapy with concomitant moderate-dose radiotherapy improves local control as well, and may facilitate surgical resection in marginally operable cases. Currently, a number of phase II clinical trials report encouraging results with concomitant chemoradiotherapy used either prior to surgery or with curative intent in locally advanced non small cell lung cancer.

Antineoplastic Agents↗
PubMed1995

Bedrest compliance for women with pregnancy problems.

Bedrest has long been recommended for high-risk pregnancies, but recent studies question its effectiveness in improving pregnancy outcomes. To be effective, the women for whom bedrest is recommended must practice it. This study examined degree of compliance and reason for noncompliance in women for whom bedrest was recommended, and outcomes of pregnancy among high-risk women who complied compared with those who did not. The subjects were 326 high-risk pregnant women who were prescribed bedrest for preterm labor, blood pressure problems, or bleeding problems. Of that group, one-third did not comply with the bedrest recommendation. These women had more children, were not currently married, had more stress, did not attend prenatal classes, continued drinking alcohol during pregnancy, and were not trying to get pregnant compared with women who complied. Reasons for noncompliance included the need to care for children, not feeling sick, household demands, lack of partner or family support, need to work, and discomfort. The pregnancy outcomes for the women who complied were similar to those of the women who did not comply. These findings support the importance of more research on the practice of prescribing bedrest to improve pregnancy outcomes.

Bed Rest↗
PubMed1995

[Sequelae in the knee extensor system following graft removal for the "Mac in Jones" type procedure].

PURPOSE OF STUDY: The aim of this study was to evaluate clinical and radiological sequelae following removal of part of the patellar tendon for A.C.L. reconstruction. MATERIALS AND METHODS: A consecutive and homogenous series of 100 patients operated for chronic anterior instability (66 men, 34 women; age 16 to 55 years, average: 28.5 years) was studied. The procedure involved a free patellar tendon graft harvested from the mid third of the tendon and including its bony attachments, and in particular a long strip from the patella and a strip 10 centimeters long from the rectus femoris tendon for extra-articular reconstruction. Tendon graft sites were closed. Patellae and tibial tunnels were filled with bone debris from the drilling, and the pre-patellar fascia was closed. The mean follow-up period was 35 months. pain and radiological alterations (with pre-operative X-rays as reference) were studied, particularly for: calcifications, patellar height changes using the Insall, Blackburne and Caton methods, increase in patella tip length, femoro-patellar joint alteration. RESULTS: Calcification were found in: quadriceps tendon: 24 per cent of cases (always painless), Pre-patellar: 16 per cent of cases (usually less than 5 mm), Superior patellar tendon: 47 per cent of cases (only 2 cases being painful, no unaffected tendons were painful), Inferior patellar tendon: 7 per cent of cases (1 in the mid), Tibia tunnel: 26 per cent of cases. No cases required surgical removal. Patellar tip length did not increased significantly. Patellar tendon length decreased by 1.37 mm. Patellar height measured by the Insall, Blackburne and Caton methods was not significantly affected. The femoro-patellar joint was normal in 95 per cent of cases. There were five cases of remodelling, one being painful. CONCLUSION: Graft harvested from the extension system for A.C.L. reconstruction frequently resulted in radiological sequelae but were usually asymptomatic. In most cases these calcifications concerned the superior patellar tendon, quadricipital tendon and pre-patellar zone. Patella height was not affected.

Adolescent↗
PubMed1995

[Distal reconstruction of the Achilles tendon with a bone-tendon graft from extensor system of the knee].

PURPOSE OF THE STUDY: The authors describe a new surgical technique of tendo achilles reconstruction using bone tendon plasty from the patellar tendon, for rare chronic ruptures of the Achilles tendon flush within its calcaneal insertion, with distal loss of substance, requiring bone fixation. METHODS: The two step operation was carried out either in lateral or ventral decubitus (the latter two involving repositioning the patient): 1) Plasty harvesting. By a short anterior approach, we harvested either a strip of patellar tendon (10 mm wide) with a piece of tibia tuberosity or a strip of rectus femoris tendon (10 mm wide, up to 10-15 cm long) with a piece of patellar bone, in cases with a greater loss of substance. Tendo achilles reconstruction: following resection of fibrous tissue, and drilling of a blind calcaneous tunnel, the bone plasty is fitted into the calcaneous with interference screw for safety, the two tendon ends are superposed and sutured. The patient is placed in a cast for two months. RESULTS: Two patients (1 thirty-eight year old sportsman, 1 thirty-seven year old woman) were treated with a good morphological and functional outcome at two years. DISCUSSION: This new technique is compared with other available solutions: triceps plasty, other local tendon plasties, artificial plasties, It met the two criteria for these unusual ruptures: solid calcaneous fixation, no skin damage.

Achilles Tendon↗
PubMed1995

[Localized small-cell lung cancers: prospects of concomitant radiochemotherapy].

Concurrent chemoradiotherapy in the treatment of small-cell lung cancer: current results and future prospects. The prognosis of small cell carcinoma of the lung is reportedly poor, even in limited disease. However, new modalities of combined chemotherapy and radiotherapy may actually result in improved survival in these patients. First-line chemotherapy regimens with cisplatin and etoposide are effective and allow early and concurrent administration of thoracic radiotherapy, without overwhelming toxicity. Radiosensitizing properties of cisplatin and etoposide have been demonstrated, and concurrent delivery of radiotherapy results in a high complete response rate on the primary tumor, and improved long-term local control, which is a prerequisite for cure. In addition, a reduction of the irradiated volume, restricted to the macroscopic tumor, appears feasible without compromising local control and results in a reduced long-term complication rate of the combined treatment. Acute toxicities of these concurrent regimens are mainly hematological and esophageal, but are reversible and without late effect in the majority of the patients. The potential benefit of a twice-daily over standard once-daily irradiation has not been conclusively demonstrated in recent trials. However, these trials have demonstrated excellent outcome after short duration chemotherapy (four courses) with early concurrent radiotherapy (45 Gy), resulting in a 40% survival at 2 years, which appears substantially higher than that obtained with the sequential or alternating regimens. The benefit of prophylactic cranial irradiation has also been confirmed in a large trial in terms of reduction of brain relapses, but with only marginal benefit upon survival. Further improvement of the prognosis of these patients may result form an early intensification of chemotherapy with the support of hematopoietic growth factors and from a dose escalation of radiotherapy with the support of three dimensional computerized dosimetry.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Radiation therapy with concomitant continuous infusion cisplatin for unresectable nonsmall cell lung carcinoma.

PURPOSE: This pilot study was designed to test the tolerance and effectiveness of concurrent continuous infusion cisplatin and radiotherapy in the treatment of unresectable nonsmall cell lung (NSCL) cancer. METHODS AND MATERIALS: Between July 1989 and July 1991, 92 consecutive patients with either medically or technically inoperable NSCL cancer were treated with thoracic radiotherapy and concomitant chemotherapy. Radiotherapy consisted of a total dose of 70 Gy delivered in 2 Gy daily fractions over 9 weeks with a planned 2-week break after 40 Gy. During the second week of each cycle of radiotherapy, cisplatin was administered, 20 mg/m2/day for 5 days as a continuous infusion. Eighty-five patients were evaluable. RESULTS: Overall response rate was 81.7% (65.9% complete response). Medically operable patients were considered for curative surgical resection following 40 Gy and one cycle of chemotherapy; 11 patients underwent resection with 3/11 having no pathologic evidence of tumor. Median survival for all 85 patients was 11.4 months with a median follow-up of 27 months. Overall survival was 48.2%, 27.5%, and 25% at 12, 24, and 36 months, respectively. Survival was independent of tumor stage, histology and grade, and patient age and gender. Patients having a complete response (n = 54) had a 2-year survival of 42.1% compared to 3.2% for partial-responders and nonresponders (n = 31; p < 0.0001). Patients undergoing surgical resection (n = 11) had a 2-year survival of 75.8% compared to 20.6% for those treated with chemoradiotherapy alone (n = 74). Forty-eight patients have died of their disease. There were two treatment-related deaths, seven deaths of intercurrent disease and three of unknown causes. Eighteen of 25 patients alive at the time of analysis were without evidence of disease. Actuarial local control was 50.6% at 1 year, and 33.3% at 2 years. The distant failure rate was 47.8% at 2 years. Major acute toxicities, mainly hematologic or gastrointestinal, occurred in less than 10% of patients. Esophagitis was mild and infrequent (8.4%). Severe late pulmonary fibrosis occurred in 5.2% of patients and resulted in two treatment-related deaths. CONCLUSION: Concomitant chemoradiotherapy was well tolerated, resulted in a high rate of local control, and in a survival benefit for patients demonstrating a complete response or going on to surgical resection. The incidence of distant metastases continues to be high and future strategies should be directed at improving systemic therapy.

Adult↗
PubMed1994

Trends in bacterial infections in febrile neutropenic patients: 1986-1992.

BACKGROUND: Bacterial infection is a major cause of morbidity and mortality in neutropenic patients. AIMS: (1) To review patterns and trends in bacterial infections in three cohorts of febrile neutropenic patients managed by a single unit over a seven year period. (2) To relate any changes to the use of central venous (Hickman's) catheters and high-dose cytosine arabinoside chemotherapy. METHODS: Retrospective review of the results of initial bacteriological work-up performed on 344 episodes of febrile neutropenia. The three cohorts were 1986-87 (n = 102), 1989-90 (n = 92) and 1991-92 (n = 150). RESULTS: (1) The ratio of gram-negative to gram-positive bacteraemias fell from 1.36 in the first cohort to 1.05 in the second and 0.40 in the third (p = 0.03). There was a fall in both percentage and number of gram-negative isolates coupled with a rise in the frequency of gram-positive isolates. (2) Coincidentally there was a rise in the frequency of positive cultures from Hickman catheter entry wounds and an increasing frequency of simultaneous isolation of the same organism from the catheter entry site and the blood. The types of organisms isolated from catheter entry wounds showed a trend towards fewer gram-negative and more gram-positive. (3) A relationship was observed between the use of high-dose cytosine arabinoside chemotherapy and the incidence of bacteraemia (p = 0.025) but not with the change in types of organisms. CONCLUSIONS: Over seven years we have documented a major change in the types of infections, particularly bacteraemias, seen in febrile neutropenic patients. In our institution the more widespread use of intravenous catheters and high-dose cytosine arabinoside chemotherapy have been identified as two possible contributing factors.

Bacteremia↗
PubMed1994

Production and Characterization of an Exopolysaccharide Excreted by a Deep-Sea Hydrothermal Vent Bacterium Isolated from the Polychaete Annelid Alvinella pompejana.

The heterotrophic and mesophilic marine bacterium HYD-1545 was isolated on a metal-amended medium from the dorsal integument of the hydrothermal vent polychaete Alvinella pompejana. This strain, which can be assigned to the genus Alteromonas on the basis of its G+C content and phenotypical features, produced large amounts of an acidic polysaccharide in batch cultures. The polysaccharide was excreted during the stationary phase of growth and contained glucose, galactose, glucuronic acid, galacturonic acid, and 4,6-O-(1-carboxyethilidene)-galactose as major components. This polysaccharide was a polyelectrolyte, and the viscosity of its solutions depended on the ionic strength. The decrease in viscosity with increasing NaCl concentrations and the effect of Ca in decreasing the viscosity at low Ca concentrations support a model in which the polysaccharide carries anionic groups. However, an unusual behavior was observed at higher concentrations and could be related to intermolecular interactions involving Ca ions.

Journal Article↗
PubMed1994

High prevalence of Helicobacter pylori infection in cohabiting children. Epidemiology of a cluster, with special emphasis on molecular typing.

Intrafamilial cases of infection with the same strain of Helicobacter pylori (H pylori) have been reported but these clusters were too small to distinguish between person to person spread or coinfection from a common environmental source. To gain more information on the mode of transmission of H pylori, an epidemiological survey with bacterial strain differentiation by restriction endonuclease analysis of chromosomal DNA was carried out in an institution of 117 children with encephalopathy (aged 3.5 to 19 years). All children with antibodies against H pylori had gastroscopy to obtain gastric biopsy specimens. The prevalence of infection (confirmed histologically or microbiologically, or both) was 38% (45/117), and rose to 67% in one of the five sections of the institution. H pylori was isolated in 34/45 cases, and 22 different strains were found of which five strains were present in more than one child. Up to seven children were infected by the same strain, five of them were living in the same section. Analysis of the characteristics of infected children showed the predominant role of living conditions and the period of time cohabiting in this unexpectedly high prevalence of H pylori infection in children living in good sanitary conditions.

Adolescent↗
PubMed1994

A randomised dosage study of ceftazidime with single daily tobramycin for the empirical management of febrile neutropenia in patients with hematological diseases.

A single-institution, randomised trial was conducted to compare the clinical and microbiological efficacy of two different doses of ceftazidime in combination with a single daily dose of tobramycin for the empirical management of febrile neutropenic patients with hematologic disorders (absolute neutrophil count < 1 x 10(9)/l). Upon the development of fever or signs of sepsis, patients received either 2 g ceftazidime every 8 h plus a single daily dose tobramycin (5 mg/kg/day) (C2T, n = 73) or 1 g ceftazidime every 8 h plus a single daily dose of tobramycin (C1T, n = 77). In addition, flucloxacillin (1-2 g every 4 h) could be added if there was clinical suspicion of staphylococcal infection. Analysis was performed for the whole group and for the subset which did not receive flucloxacillin. When evaluated at 96 h, 70% (95% CI, +/- 11%) of patients randomised to C2T and 60% (95% CI, +/- 11%) randomised to C1T had responded (chi 2 = 1.27, P = 0.26). The response rates at 96 h for those who did not receive flucloxacillin were 77% (+/- 12%) and 74% (+/- 13%), respectively (chi 2 = 0.01, P = 0.92). Overall, 68 (93% +/- 6%) and 72 (94% +/- 6%) patients, respectively, eventually became afebrile (chi 2 = 0.06, P = 0.81). Renal function, as judged by serum creatinine, was unaffected by either antibiotic schedule. Within 10 days of antibiotic commencement there was one death in each arm and overall there were five deaths in each arm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

A comparison of the binding of biotin and biotinylated macromolecular ligands to an anti-biotin monoclonal antibody and to streptavidin.

A competitive enzyme immunoassay was used to study the binding of biotinylated macromolecular ligands and d-biotin to an anti-biotin monoclonal antibody and to streptavidin. Solid phase BSA-c-biotin competed with biotin or biotinylated macromolecular ligands in solution for receptor binding. The concentration of d-biotin required to inhibit streptavidin binding to solid phase BSA-c-biotin by 50% was 11.5 pM. This streptavidin-biotin interaction was taken as having an affinity/avidity index of 100 and all other receptor-ligand interactions were calculated relative to this. The avidity indices calculated for streptavidin interactions with BSA-c-biotin and IgG-biotin were 17.6 and 6.6 respectively, whereas for anti-biotin the values for these ligands were 20.5 and 19.9 respectively. The interaction of anti-biotin with d-biotin had an affinity index of 0.001. Although streptavidin has the greatest binding affinity for d-biotin, its avidity for biotinylated ligands was considerably lower and comparable to that observed for anti-biotin-biotinylated macromolecule interactions.

Animals↗
PubMed1993

Translocation (Y;1)(q12;q21) in acute leukemia.

This report documents one patient with myelodysplasia evolving into acute leukemia who showed a t(Y;1) translocation confirmed by in situ hybridization. Most of the q arm of the Y chromosome was translocated to an additional q arm of chromosome 1, resulting in trisomy 1q. To our knowledge only four other cases with this t(Y;1) have been reported.

Adult↗
PubMed1993

Combined radiation therapy and cisplatin for locally advanced carcinoma of the urinary bladder.

BACKGROUND: This study evaluates feasibility and results of combined treatment of cisplatin and radiation therapy for patients with inoperable invasive bladder carcinoma. METHODS: From January 1988 to October 1991, 69 patients received radiation therapy and concomitant cisplatin. Median age was 71 years. Most tumors were locally advanced and high grade. A macroscopically complete transurethral resection was performed initially in 18 patients. Dose of pelvic radiation ranged from 40 Gy to 45 Gy, and total dose to the bladder ranged from 55 Gy to 60 Gy. Concomitant continuous cisplatin infusion at a dose of 20-25 mg/m2/day for 5 days was delivered during the 2nd and 5th weeks of radiation. RESULTS: As of April 1993, the median follow-up time was 36.4 months (range, 18-70 months). Ninety-one percent of the patients completed radiation therapy as planned, and 78.3% completed two courses of chemotherapy. Despite one treatment-related death due to renal failure, toxicity was generally mild and acceptable. Sixty-three patients were evaluable for response. Forty-eight patients (76.2%) achieved a complete response. Actuarial overall 3-year survival rate was 37.1% for all patients. Among the patients who experienced complete response, the 3-year actuarial local control and disease-free survival rates were 65.4% and 56.3%, respectively. Twenty-six patients (37.7%) are alive and disease-free with bladder preservation. One patient is alive and disease-free after salvage cystectomy. CONCLUSIONS: Concomitant cisplatin and radiation therapy offers high probability of complete response and local control in patients with invasive bladder cancer unsuitable for surgery. These results provide a basis for randomized studies comparing this approach with conventional therapy for patients with operable carcinoma.

Aged↗
PubMed1993

Idazoxan decreases estrogen-induced lordosis in female but not "hormone-independent" lordosis in male guinea pigs of an inbred strain.

This experiment examined whether the imidazoline idazoxan (which binds to alpha-noradrenergic receptors and to imidazoline-preferring sites) interferes with hormone-dependent or hormone-independent lordosis responses. Ovariectomized (ovx) Strain 2 female guinea pigs which were sexually receptive after receiving estradiol benzoate (EB; 3 micrograms/d for 3 days) were injected with either idazoxan (10 mg/kg) or with vehicle at 24 hr after the last EB injection. Idazoxan significantly decreased EB-facilitated lordosis responses in these females. Castrated Strain 2 males, which show lordosis behavior without gonadal hormone administration, were injected with the same dosage of idazoxan (10 mg/kg) or with vehicle. Idazoxan did not inhibit lordosis behavior in these males.

Adrenergic alpha-Antagonists↗
PubMed1993

Neighboring cerebellar Purkinje cells communicate via retrograde inhibition of common presynaptic interneurons.

Paired tight-seal whole-cell recordings were obtained from neighboring Purkinje cells in cerebellar slices. Under voltage clamp, spontaneous inhibitory postsynaptic currents resulted from the activity of GABAergic interneurons, stellate and basket cells. Up to 80% of inhibitory postsynaptic currents in paired recordings were in register. This correlation was not affected by antagonists of glutamate receptors, faded with distance, and was abolished by tetrodotoxin. Earlier work showed that voltage-gated Ca2+ entry into a Purkinje cell elicits a transient presynaptic inhibition of inhibitory postsynaptic currents. It is now shown that this inhibition is not restricted to the stimulated cell, but that it is transmitted to its neighbors. The results indicate that Purkinje cells exchange information by an unconventional mechanism involving retrograde control of inhibitory synapses.

Animals↗