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Biomedical subjects

M Marchand

Publications and source records attributed to M Marchand.

At least 91 records · Page 5Linked to original sources
PubMed1988

[Control of the patency of coronary-internal mammary artery bypasses by non-selective angiography].

98 successive coronary bypasses using the internal mammary artery were controlled systematically, at an early stage, about the 17th postoperative day, by non selective brachial angiography using a retrograde injection. This control method, simple, quick, reliable and non-aggressive, enables to visualize the internal mammary artery and the bypassed coronary vessel, over its entire length. There were no failure in the control, nor any local or general complication during this examination. The overall patency of such bypasses, evaluated with this method, is 98 p. cent in our series, with however, 12 p. cent of angiographic aspects of a poorly functional bypass. These aspects are related to a slow flow in the by-pass (spindly internal mammary artery, anastomotic stenosis or thin distal bed of the bypassed coronary artery), or to a competitive flow (non significant coronary stenosis). The perfusion of the bypassed coronary, which is not so well studied in the literature, is important to analyze and difficult to evaluate with our technique because of the static views that are used. A similar non-selective angiographic method using a dynamic recording (radio-cinema with dual incidence) is currently being evaluated.

Adult↗
PubMed1987

Rules and incentives for hospitals: the Belgian financing system.

The purpose of the paper is to analyze the set of rules and mechanisms that control the financing of Belgian hospitals. It emphasizes their effects on economic incentives for hospital managers and physicians. For this purpose, it is first necessary to understand how the social security system and the health care sector are organized in Belgium. The paper first describes their main features. The paper then gives an historical overview of recent developments in the financing of Belgian hospitals. It emphasizes the double source of hospital revenues, i.e., patient per-diam prices and medical practice fees, although its main concern is with the evolution of the rate-setting process for the per-diem prices. Since the 1981 decision to freeze the per-diem prices and patient-day quotas for individual hospitals, proposals for changes in the financing system have been under study. Implementation of some of these changes began in 1986. The major modification involved is to correct historical per-diem prices by means of interhospital cost comparisons. The paper ends with a critical appraisal of these latest developments. It focuses on the advantages and shortcomings of the pre-1986 system and of the recent changes. The accent is put on the economic incentives and their effects on the behavior of hospitals.

Belgium↗
PubMed1987

Variants with reduced virulence derived from Leishmania major after mutagen treatment.

After several in vitro treatments of a virulent population of Leishmania major with the mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), five clones (vir-) were obtained that did not produce cutaneous lesions after subcutaneous injection of 10(6) promastigotes. All the control clones (vir+) obtained from the non-mutagenized parasite population produced progressive cutaneous lesions with as few as 10(3) parasites. Late lesions were observed occasionally after injection of 10(7) vir- parasites. These late lesions appeared to result from the selection of virulent revertants, since parasites isolated from these lesions produced progressive lesions in BALB/c mice almost as readily as the control parasites. Two vir- clones, one vir+ clone and one revertant clone were examined for survival in BALB/c macrophages in vitro. All clones were taken up by the macrophages and transformed into amastigotes. However, vir- clones failed to multiply inside the macrophages. A vir- clone was found to protect mice against a subsequent challenge with vir+ parasites.

Agglutination↗
PubMed1987

Computerized single-breath nitrogen washout in children: variability and reproducibility.

The variability, short-term (1 hour) and long-term (2 weeks) reproducibility of the variables derived from the single-breath N2 test were evaluated in a group of 56 healthy children aged 10 to 16 years with a computerized system. The variability was low for vital capacity and total lung capacity (coefficient of variation less than 3%), moderate for residual volume and phase III N2 slope (9 and 13%) and very high for closing volume (more than 50%). A closing volume could not be identified by the computer algorithm in 18.3% of the trials. The reproducibility of the variables was satisfactory both at 1 hour and at 2 weeks, with the exception of the closing volume, whose increase at 2 weeks seemed to be due to methodological factors. We conclude that reliable results of static lung volumes and phase III N2 slope, but not of closing volume, may be obtained in children by a computerized system in epidemiological studies.

Adolescent↗
PubMed1987

[Massive hemolysis and acute mitral insufficiency one year following mitral valve repair. Apropos of a case].

The authors report a case of massive haemolytic anaemia with acute mitral valve regurgitation and left cardiac failure, which occurred one year after surgical reconstruction of the mitral valve for rupture of smaller leaflet chordae. Anaemia, mitral regurgitation and cardiac failure disappeared after mitral valve replacement, using a Carpentier Edwards No. 29 valve. Haemolytic anaemia following mitral valve reconstruction is exceptional. It seems to be due to the suture material lying in a turbulent regurgitation stream when mitral incompetence develops again.

Acute Disease↗
PubMed1987

[Effect of loperamide on fecal flora of children with severe prolonged diarrhea].

Loperamide has recently been proposed in the management of infants with severe protracted diarrhea. The purpose of this study was to determine the effect of loperamide (0.5 mg/kg/d) on fecal flora in 19 cases of severe protracted diarrhea. Criteria analysed were: clinical tolerance (vomiting and abdominal distension) and efficacy (number of stools, transit time and Na/k in stools); complete identification and counts of aerobic and strict anaerobic bacteria in fresh stools before and 4 to 8 days after the beginning of loperamide. Parental and/or oral alimentation remained unchanged during the entire study. Clinical resolution of diarrhea was rapid (less than 24 h) in 9 of 14 patients. In 2 cases ileus was observed and resolved when loperamide was discontinued. Although important changes in specific fecal flora counts was noticed for streptococcus D and proteus as compared to 5 controls, no bacterial overgrowth appeared or was worsened during loperamide treatment.

Child, Preschool↗
PubMed1986

[Inferior vena caval return to the left atrium with intact interauricular septum. Apropos of 2 cases surgically treated with success].

Two cases of abnormal inferior vena caval return to the left atrium are reported in a 9 year old boy and 13 year old girl. The diagnosis was suspected on the finding of severe cyanosis alone, and the anomalous systemic venous return was correctly identified by angiography of the inferior vena cava. There were three angiographic points of interest in these two cases: the normal position of the inferior vena cava, the absence of a left-to-right interatrial shunt and the presence of a vertical intra-left atrial "membrane" inserted behind the orifice of the inferior vena cava. Surgical correction consisted in resecting the inferior part of the interatrial septum and reconstructing a new septum behind the orifice of the inferior vena cava with a dacron patch in one case and by direct suture in the other. The good surgical result was controlled by angiography in both cases. In the second case, an intrapulmonary shunt due to multiple arteriovenous fistulae demonstrated by contrast echocardiography was responsible for persistent mild cyanosis for a few months after surgery. The long-term clinical results were excellent in both cases. The authors review the literature of this rare malformation due to persistence of part of the right valve of the sinus venosus.

Arteriovenous Malformations↗
PubMed1985

A limiting dilution assay for quantifying Leishmania major in tissues of infected mice.

A limiting dilution assay for the quantification of Leishmania major in infected mouse tissue was developed. The assay was found to be both sensitive and reliable, and, due to its design, could be scored either visually or following the incorporation of 3H-thymidine by the growing parasites. Results are presented in which the assay was employed to enumerate L. major in the tissues of susceptible (BALB/c) and resistant (CBA) mice at intervals after infection with L. major. It was found that parasites could be detected at the site of injection with L. major as early as 3 days after infection. By day 8, a substantial increase in the number of parasites at the lesion site had occurred in both strains of mice. Subsequently, whereas the number of parasites decreased in the lesions of CBA mice, their number steadily increased in the lesions of BALB/c mice. Parasites were detected in lymph nodes draining the lesion site in both BALB/c and CBA mice by 28 days after infection. Interestingly, a low number of L. major was found in the lymph nodes of CBA mice at 100 days after infection, a time when no parasites could be detected at the lesion site. Previous results from this laboratory have demonstrated that the adoptive transfer of L. major-specific L3T4-positive T-cell populations exacerbated cutaneous lesions induced by L. major in BALB/c mice. Experiments presented here indicate that the adoptive transfer of L. major-specific T-cells also exacerbated cutaneous leishmaniasis in CBA mice. Using the sensitive limiting dilution assay presently described, it was found that this unexpected exacerbative effect of L. major-specific T-cells on lesion development was accompanied by a substantial increase in the number of parasites in the lesions of the adoptively transferred mice.

Animals↗
PubMed1985

[Computerizing the single-breath nitrogen washout test].

The classical assembly used for the single breath nitrogen washout implies the manipulation of valves by the operator, a perfect coordination of respiratory maneuvers by the subject and a rigid standardization of the interpretation of the tracings by the technicians doing the calculations. We present a computerized analysis of the single breath nitrogen test, based on a microcomputer (Apple II 48K) solving most of the problems above. The opening of the valves is operated by the computer program recorded on disk; the tidal volume and expiratory flow are displayed on the screen on line allowing the subject to comply with the requested limits; the nitrogram is displayed at the end of the test, allowing the technician to explain the errors (if any). The program then goes on computing the slope of phase III, the closing volume, total lung capacity and its subdivisions for each trial, and the average values for two or three trials accepted by the operator. The system worked satisfactorily during a pilot study in healthy adults (variability and reproducibility) and was particularly useful in a field survey of children and adolescents.

Closing Volume↗
PubMed1985

[Effects of incomplete inspiration and previous pulmonary volume history on the nitrogen test].

The effect of incomplete inspiration and of preceding lung volume history on the different parameters of the expired nitrogen curve after inhaling pure oxygen were studied in 12 healthy non-smokers, aged 21 to 35. The equipment used was attached to a mini-computer enabling the regulation of the measurements and the performance of the tests with immediate calculations on the different indices derived from the curve (VC, RV, TLC, delta N2, CV-closing volume, CV/VC). With each subject three measurements were made: measurements in the normal way (N) after incomplete inspiration (I) and finally after 5 forced inspirations and expirations (previous history - P). The procedure (I) gave values of VC and TLC which were lower than those observed with the other methods and the slope of delta N2 and the CV/VC were higher. After the previous lung volume history (P) VC and TLC were significantly higher, the CV/VC ratio was lower (due to the increase of CV). The measurement technique was not influenced either within sessions or between sessions a week apart.

Adult↗
PubMed1984

Trypanosoma cruzi variants with reduced virulence obtained by mutagenesis.

Previous reports have indicated that by mutagen treatment of mouse tumour cells in vitro it is possible to obtain at high frequency stable tumour cell variants that fail to form tumours in syngeneic mice because of increased immunogenicity. By analogy with these tumour cell variants, we examined whether variants with reduced virulence could be obtained by mutagen treatment of trypomastigotes derived from a Trypanosoma cruzi strain that was adapted to culture and produced lethal infections in DBA/2 mice at a dose of 5 X 10(4) parasites. A very large frequency of T. cruzi clones were obtained that failed to provoke an acute lethal infection after injection of 5 X 10(5) parasites. Most of these variants with reduced virulence (vir-) multiplied actively in normal mice until day 8 after injection. After that time the parasitaemia decreased gradually. For most variants a low level of residual parasitaemia persisted for more than 100 days. Unlike the situation encountered with mouse tumour cell variants it was not possible to demonstrate the presence of new antigens on the T. cruzi vir- variants. However, these variants seemed to have acquired an increased immunogenicity since they provoked the rejection of virulent parasites injected concomitantly. Mice that had been immunized with living vir- clones were protected against a challenge with a virulent clone derived from the original parasite population.

Animals↗