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Biomedical subjects

P Vincent

Publications and source records attributed to P Vincent.

At least 109 records · Page 6Linked to original sources

Serodiagnosis of tuberculosis. Evaluation of a sulpholipid antigen.

In order to evaluate the suitability of serology in the diagnosis of tuberculosis the Mycobacterium tuberculosis anti-sulpholipidic IV IgG were assayed, using the ELISA test, in 41 healthy controls, 121 hospitalized but non-tuberculous patients and 142 tuberculous persons including 46 cured patients. At the 150 and 300 O.D. thresholds proposed in previous studies using the same antigen, the specificity was 88.27% and 98.76%, respectively, and the sensitivity 25% and 11.45%. These results were not related to different potential factors (age, background, associated pathology) but to infection intensity which enhanced the IgG reaction. This may explain discrepancies observed in previous studies made under other epidemiological conditions. Therefore, in this European population from a universitarity hospital, it appears that too many tuberculous patients have such a low IgG reaction that serology cannot be an effective assay in the diagnostic step.

Adult↗

ED1-containing cellular fibronectin release into lung lymph during lung vascular injury with postoperative bacteremia.

Fibronectin (Fn) exists in both a soluble and insoluble form. Soluble Fn in plasma and lymph is an opsonic molecule that enhances phagocytic host defense. Insoluble Fn in the subendothelial and extracellular matrix is an adhesive molecule that mediates cell adhesion to substratum. The extracellular matrix of tissues such as the lung contains a mixture of both plasma-derived fibronectin (pFn) as well as locally synthesized cellular fibronectin (cFn). cFn is antigenically related to pFn, but cFn has extra domains (ED1 and ED2) that do not exist in liver synthesized pFn. The purpose of this study was to determine whether ED1-Fn was released into lung lymph before an increase in lung vascular permeability following postoperative bacteremia. Male sheep (n = 8) with surgically prepared lung lymph fistulae were infused intravenously with a sublethal dose (5 x 10(8)) of Pseudomonas aeruginosa 2 days following surgery. Lymph flow (QL), lymph-to-plasma (L/P) total protein ratio, lung protein clearance (QL x L/P), and hemodynamics were measured over 48 h following bacterial challenge. The lymph and plasma ED1-Fn concentrations were determined by enzyme-linked immunosorbent assay (ELISA) using a murine monoclonal antibody specific to the ED1 region of human cFn. There was a rapid rise of ED1-Fn flux in lung lymph which was evident 60 min after the start of bacterial infusion, resulting in a maximum three- to fourfold increase (P < 0.05) in this parameter. In contrast, the ED1-Fn concentration in plasma before bacterial infusion was less than lung lymph and it did not increase over the initial 6 h following bacterial infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Treatment of obstructive bronchial cancers with high dose, endobronchial curietherapy. Technical aspects and clinical results].

Between September 1990 and September 1991, 35 patients with mainly recurrent or residual endobronchial carcinoma were treated with 91 high-dose-rate endobronchial brachytherapy applications. Treatment technique was fairly simple and could easily be performed on an outpatient basis. Endoscopic placement of one or two applicators is followed by computerized dosimetry and irradiation during a median time of 10 minutes. Treatment included 3 sessions of 10 grays measured at 10 mm from the center of the radioactive source at 2-week intervals. Response rate was 81.8% including 51.5% complete clinical response. There were 12 microscopically complete response out of 14 patients biopsied. Immediate tolerance was excellent in 90% of cases. However, late complications were severe in 25% of cases. Ongoing radiobiological research should determine an optimal therapeutic approach in term of efficacy and long term toxicity before using endobronchial brachytherapy as a part of the initial management of unresectable lung cancers.

Adult↗

Single daily ceftriaxone and tobramycin in the empirical management of febrile neutropenic patients: a randomised trial.

A single-institution, randomised pilot trial was conducted to compare the clinical efficacy, microbiological efficacy and possible toxicity of empirical single daily antibiotic administration in febrile neutropenic patients with haematologic disorders (absolute neutrophil count < 1 x 10(9)/l). Upon the development of signs of sepsis, patients received either single daily dose tobramycin (5 mg/kg per day) plus ceftriaxone (2 g/day) (C + T, n = 47) or tobramycin (1.5 mg/kg, every 8 h) plus azlocillin (4 g, every 6 h) (A + T, n = 45). In addition, flucloxacillin (1-2 g, every 4 h) could be added if there was clinical suspicion of staphylococcal infection (17 in each arm). Analysis was performed for the whole group and for the subset which did not receive flucloxacillin. When evaluated at 96 h, 62% of patients randomised to C + T and 67% randomised to A + T had responded (95% confidence interval (CI) for the difference in rates, -25% to +15%). Ninety-six hour response rates for those who did not receive flucloxacillin were 73% and 78%, respectively (95% CI, -17% to +27%). Overall, 42 (89%) and 41 (91%) patients, respectively, eventually became afebrile (95% CI, -14 to 10%) and there was no evidence of altered renal function or electrolyte imbalance in patients randomised to single daily antibiotic therapy compared with the conventional (multi-daily dose) arm. Within 10 days of antibiotic commencement there was 1 death in the C + T arm and 4 deaths in the A + T arm, although overall there were 4 deaths in each arm. Our results suggest that single daily empirical antibiotic therapy with tobramycin and ceftriaxone is efficacious and is not associated with an increased incidence of renal dysfunction or electrolyte imbalance compared with conventional administration schedules of azlocillin plus tobramycin. Single daily therapy has the potential to lead to savings in nursing-staff time and materials and may well contribute to an improved quality of life for febrile neutropenic patients.

Adolescent↗

Are we teaching leadership as a value?

Using the Survey of Interpersonal Values developed by Gordon, a longitudinal study was done to determine value changes of a cohort group of baccalaureate nursing students as sophomores and seniors. Four of six values showed statistically significant changes: leadership and recognition increased as values, while conformity and benevolence decreased. Support and independence showed no significant change.

Cohort Studies↗

Early onset of lithium-associated hypothyroidism.

In general practice, psychiatrists are confronted with the difficulty of structuring a rational design for the early detection of hypothyroidism. To determine the period during which a patient receiving lithium is most at risk of developing hypothyroidism, a retrospective study was conducted on the records of 154 patients at two general hospital lithium clinics from January 1980 to August 1991. Forty-two cases of hypothyroidism (clinical hypothyroidism and/or abnormally elevated levels of TSH) were detected. A significant difference was found between the onset of hypothyroidism and age (older patients developed more thyroid dysfunction), but no significant differences were found between thyroid abnormality and sex or diagnostic category and menopausal status, although trends were observed for the two former variables. This longitudinal study is the first to describe an outline of thyroid functioning in terms of the duration of treatment. Lithium-associated hypothyroidism develops most often during the first two years. Of the 42 cases of hypothyroidism, 16 were diagnosed within six months (38%), 23 within the first year (55%), and 31 two years (74%). Since thyroid functioning is an important parameter in the course of affective disorders, its close and frequent monitoring is mandatory during the first two years of treatment.

Adult↗

Serum prostate-specific antigen in monitoring the response of carcinoma of the prostate to radiation therapy.

In order to assess the value of serum prostate-specific antigen (PSA) levels in the monitoring of patients with localized prostatic carcinoma undergoing radical radiation therapy, 146 previously untreated patients were entered into this study. Sixty to 70 Gy were administered to the prostate over 8 to 9 weeks. Serum PSA levels were measured prior to radiotherapy, every 3 months during the first year and every 6 months thereafter. Median follow-up was 28 months. Pretreatment PSA values exceeded 10 ng/ml in 62% (91/146). Initial PSA values were correlated with tumor size and Gleason score. Six months after completion of radiation therapy, PSA levels decreased as compared to initial value in 88.3% of the patients. It had fallen to 10 ng/ml or less in 54 (59%) out of the 91 patients with initial abnormal PSA levels. Patients whose initial PSA exceeded 50 ng/ml attained levels of 10 ng/ml or less in only 19% of the cases (6/32). Only 3 of the 55 patients (5.5%) with both initial and 6-month PSA values less than or equal to 10 ng/ml developed metastasis. Out of the 91 patients with initial PSA values over 10 ng/ml, 54 (59.6%) had a 6-month PSA level of 10 ng/ml or less, and only 4/54 (7.4%) relapsed. By contrast, 13 of the 37 patients (35.1%) with a 6-month PSA value persistently above 10 ng/ml relapsed. The 3-year relapse-free survival is 85.1% for patients with a 6-month PSA level less than or equal to 10 ng/ml, and 50.2% for patients with persistently elevated PSA values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗

Cationic channels sensitive to extracellular ATP in rat lacrimal cells.

1. Responses of isolated rat lacrimal cells to local applications of ATP were studied using tight-seal whole-cell recording and/or Fura-2-derived calcium concentration measurements. 2. In cells where variations in Ca2+ concentration were prevented by use of a strong Ca2+ buffer, ATP was found to induce an inward current response at negative holding potentials. With 10 microM-ATP, the current amplitude ranged between 20 and 200 pA. The reversal potential of this ATP-induced current was close to 0 mV with normal external solution and shifted to -19 +/- 3 mV (mean +/- S.D.) when the concentration of external monovalent cations was halved. These results indicate that the channels have a cationic selectivity. The response amplitude decreased markedly from trial to trial, indicating a desensitization process which was irreversible on the time scale of the recordings. 3. Steady state I-V curves for the ATP-induced current in normal saline showed a marked inward rectification. This rectification appeared to be linked to a time-dependent activation of the channels, as hyperpolarizing voltage jumps elicited a time-dependent current increase. This relaxation could be fitted by a double-exponential function, with time constants (at -120 mV) of 0.9 +/- 0.3 ms and 110 +/- 6.4 ms. 4. Variance analysis of the ATP-induced current gave a single-channel current value of 0.34 pA at -60 mV. The single-channel current amplitude varied linearly with potential, with a slope close to 6 pS. The relation between noise covariance and time could be fitted by a double-exponential function, with time constants (at -60 mV) of 0.8 +/- 0.4 ms and 6.8 +/- 3.4 ms (mean +/- S.D.). 5. In an isotonic Ca2+ solution, 10 microM-ATP induced an inward current at -60 mV with a calculated single-channel current amplitude obtained from noise analysis close to 0.2 pA. In an external solution containing 10 mM-calcium and no sodium, 50 microM-ATP elicited a current with a reversal potential of -19 mV. 6. Fura-2 measurements were performed in intact cells or in cells dialysed with a low concentration of Ca2+ buffer (e.g. 0.5 mM-EGTA). Under such conditions ATP induced increases of the internal Ca2+ concentration with very variable amplitudes. In some cells Ca2+ rises of 50 nM or lower were found. Minimal activation of Ca(2+)-dependent channels was then observed. In other cells large Ca2+ rises (up to 500 nM) were observed and were then correlated with marked activation of Ca(2+)-dependent channels.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗

Inhibitory synaptic currents in rat cerebellar Purkinje cells: modulation by postsynaptic depolarization.

1. Synaptic currents were recorded in voltage-clamped cerebellar Purkinje cells using the tight-seal whole-cell recording technique. Cells were dialysed with a CsCl solution and were held at -60 or -70 mV. Inhibitory interneurones (basket and stellate cells) were stimulated using an extracellular pipette positioned in the molecular layer. Blockers of excitatory glutamatergic synapses were included in the bath solution. 2. Evoked synaptic currents were observed after a latency of 3-4 ms. The time course of synaptic currents could in most cases be fitted to a biexponential curve, with a rise time constant, tau on, of 1-3 ms and a decay time constant, tau off, of 7-13 ms. These currents were blocked by bicuculline. 3. The mean amplitude of evoked synaptic currents increased in discrete steps when the voltage applied to the stimulating pipette was increased. At each level, very prominent fluctuations of the amplitude were observed among trials. 4. Complex synaptic currents corresponding to repetitive activity of the presynaptic interneurone were occasionally observed, particularly with high intensity presynaptic stimulation. This repetitive activity could lead to bursts of synaptic currents lasting for several seconds. 5. Following a depolarizing voltage train in the postsynaptic Purkinje cell, the amplitude of evoked synaptic currents was first inhibited, and then potentiated. The inhibition was accompanied by a small but consistent increase in tau off and by no alteration in tau on. When using small intensity presynaptic stimuli, it was found that the probability of failures was greatly enhanced. The inhibitory phase lasted for about 1 min before giving way to potentiation. The potentiation returned to the control with a time to half-decay of 12.9 +/- 0.9 min. 6. The present results give further evidence to a previously proposed hypothesis that the inhibition produced by Purkinje cell depolarization is mainly presynaptic. The longer lasting potentiation, on the other hand, has most probably a postsynaptic origin. Cerebellar Purkinje cells receive inhibitory GABAergic inputs from two classes of interneurones located in the molecular layer (reviewed in Palay & Chan-Palay, 1974; Ito, 1984). Basket cells are closest to the Purkinje cell layer and address their inhibitory signal primarily to the soma and to the main dendrites. Stellate cells are more externally located and have contacts with the more distal part of the dendritic arborization of Purkinje cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

[Pathological gambling: literature revue].

This paper summarizes the current literature on pathological gambling. Interest in gambling has been present in every society but treated as an object of sociopolitical or literary interest. It is only from the beginning of this century that psychiatry began to look at pathological gambling, first with Freud and his writing on Dostoïevsky then with other theories like the learning theory, studies on substance dependence, the links with affective syndromes and the psychobiological studies. These studies are presented and discussed. Finally, the authors offer some guidelines for an approach to a pathological gambler.

Behavior, Addictive↗

[Dysmorphophobia (body dysmorphic disorder)].

This article reviews the historical and terminological origins of dysmorphophobia from Herodotus to today. It explains the differences pointed out by many authors, including the DSM-III-R, between body dismorphic disorder and delusional disorder somatic type, which are referred to as monosymptomatic hypochondriacal psychoses in Europe. Epidemiological data, clinical characteristics and outcome are discussed. Explicative theories and neurobiological, developmental and analytical aspects of body image are presented. The association between body dismorphic disorder and other disorders is analyzed, and treatment possibilities are discussed. The authors suggest that body dismorphic disorder be classified with obsessive compulsive disorder, whatever the intensity of symptomatology, rather than with somatoform or delusional disorder, and treated with serotonin uptake inhibitors or neureptics that have been proven to be effective for the treatment of this disorder, such as pimozide.

Body Image↗

ESR spin trapping analysis of gamma induced radicals in sucrose: II.

Radicals induced by gamma-irradiation of sucrose, in the solid state at different temperatures and in aqueous solution, have been investigated by the spin trapping method. Electron spin resonance (ESR) combined with high performance liquid chromatography (HPLC), followed by spectral analysis with a simulation program (Voyons) revealed seven main radical species. A comparative study of the ESR signals from spin trapped gamma-induced radicals in some glycosides, disaccharides, 13C specifically labelled carbohydrates, as well as in several deoxysucroses and fructans, led to the assignment of a chemical structure to five out of the seven sucrose-nitroxide adducts previously evidenced. Sucrose is shown to be a conceivable model for the study of fructans gamma-radiolysis mechanism in aqueous solution.

Carbohydrate Sequence↗