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Biomedical subjects

M Rousseau

Publications and source records attributed to M Rousseau.

At least 55 records · Page 3Linked to original sources
PubMed1990

Surgical angioplasty of the left main coronary artery.

The conventional surgical treatment of isolated critical stenosis of the left main coronary artery restores a less physiologic perfusion of the myocardium, leads to occlusion of the left coronary ostium, and consumes an appreciable length of bypass material. Starting in June 1985, 23 surgical angioplasties have been performed in 22 patients. The left main stem was approached posteriorly in the first 11 patients, and an anterior approach was preferred in the last 12 because of better exposure. The onlay patch consisted of saphenous vein in the first 14 patients; pericardium was preferred in the last nine. The five failures occurred early. Four of these occurred in patients older than 60 years in whom calcifications of the left main stem had been seen on the preoperative angiogram. Eighteen procedures (78.3%) succeeded, but one patient (5.5%) died later of a massive air embolism. The 17 survivors are free of symptoms (maximal stress test combined with thallium scintigraphy) after a mean follow-up of 24.3 months. Angiographic restudy at an average of 8 months was obtained in 14 patients (82.3%) and revealed an excellent result in 13. In five patients, a late angiographic restudy (22 to 37 months) still revealed perfect patency of the left main stem. Provided that well-defined contraindications (calcifications, involvement of the distal bifurcation, older age) are respected, surgical angioplasty deserves a place in the array of surgical strategies.

Adult↗
PubMed1989

Localization by hand-held gamma probe of tumor labeled with antibody "cocktail".

Five groups (n = 4) of congenitally athymic female nude mice bearing subcutaneous implants of CX-1 and/or SW-1116 tumor in the hind limbs received iodine-125 radio-labeled monoclonal antibodies (MoAbs) B72.3 (two groups), 17-1A (two groups), and cocktail (one group) (iodogen method, 50 microCi/10 micrograms/mouse). Daily probe counts were made in duplicate with a hand-held detector over each tumor site and the front leg (background) for 21 days. Animals were sacrificed and appropriate well counts were obtained. All the single MoAb preparations localized well in both tumor cell lines. Uptake of monoclonal antibody 17-1A was similar in the two tumor cell lines, with counts initially high and slowly decreasing over the 21-day period. Tumor/background ratios continued to increase over time, indicating that both tumor lines have similar antigenic expression for the monoclonal antibody 17-1A. This was not the case for monoclonal antibody B72.3, which showed a preferential uptake by the CX-1 tumor, with higher initial counts and prolonged binding of the antibody, giving rise to higher tumor/background ratios. The mixture of monoclonal antibodies B72.3 and 17-1A markedly improved the uptake by the CX-1 tumor cell line but not that by the SW-1116 cell line, where the effect was negative when compared to the uptake of the single MoAb preparations. The use of a monoclonal antibody mixture can enhance targeting of some tumor sites. Due to the heterogeneity of tumor cell lines, even within the same animal, different mixtures of monoclonal antibodies are needed to increase the targeting of tumor.

Adenocarcinoma↗
PubMed1989

An assessment of prolonged reactivity of seven monoclonal antibodies against CX-1 tumor xenografts using a hand-held gamma-detecting probe.

The biodistribution and kinetics of 7 monoclonal antibodies (MAb) with known reactivity against CX-1 tumor were examined over 21 days using a hand-held gamma-detecting probe (Neoprobe system). Twenty-eight immuno-deprived (athymic) nude mice implanted with human colon adenocarcinoma CX-1 xenografts were injected intraperitoneally with 50 microCi of 125I-labeled antibodies (4 mice/antibody). Of the 7 monoclonal antibodies, 4 were anti-CEA (MA, MB, MC, and MD), 2 were anti-TAG 72 (B72.3 NCI and B72.3 fermented) and one was anti-colorectal cancer (17-1A). Daily probe counts were recorded in duplicate over the tumor site and the contralateral nontumor site (background), and tumor-to-background (Tu/Bkg) ratios were calculated. Animals were sacrificed on day 21, and blood, heart, liver, spleen, lungs, kidneys, intestine, muscle, and the tumor were removed for gamma well counting. All antibodies identified the tumor as early as 24 h postinjection and specific tumor localization improved over time. Patterns of prolonged tumor binding varied considerably from one antibody to another, although all but one (MB) showed continuously increasing Tu/Bkg ratios. These data indicate progressive clearance of the antibodies from the background tissue and a persistence of labeled MAb activity in tumor resulting in improved tumor localization with increasing postinjection time.

Adenocarcinoma↗
PubMed1989

Sequential mammary grafting. Clinical, functional, and angiographic assessment 6 months postoperatively in 231 consecutive patients.

Between September 1985 and November 1987, 246 sequential mammary grafts were performed in 231 consecutive patients. Seventy-eight percent had triple vessel disease, and 33% required an urgent procedure. The length of the internal mammary artery pedicle was the only limitation to its use. No account was taken of the free cut-end flow of the internal mammary artery. There were 14 bilateral sequential mammary grafts and 15 free sequential mammary grafts. Of the 531 sequential mammary anastomoses, 482 were built with the left internal mammary artery; 113 (21%) were diamond-shaped anastomoses. The right internal mammary artery was brought through the transverse sinus in 44 cases, 10 times for sequential grafting of circumflex branches. Taking into account the adjunctive venous anastomoses and the single internal mammary artery anastomoses, there were 4.5 distal anastomoses per patient, 2.8 being mammary anastomoses and 2.3 being sequential mammary anastomoses. The hospital mortality rate was 2.6%. The prevalence of perioperative myocardial infarction was 5.2%. Follow-up was complete and averaged 15.4 months. Six patients (2.7%) still had angina pectoris. One hundred fifty-seven (71%) patients were recatheterized 6 months after the operation, and 95% of the sequential mammary anastomoses were still patent. The patency rate of the diamond-shaped mammary anastomoses was 94.5% and that of the anastomoses corresponding to the right internal mammary arteries brought through the transverse sinus was 94.3%. The gratifying functional results (maximal stress test combined with exercise thallium scintigraphy) obtained at an average of 6 months postoperatively illustrated the surprising physiologic adaptability of the internal mammary artery. As the attrition rate of the mammary artery grafts beyond 6 months postoperatively is thought to be minimal, gratifying long-term results with widespread use of sequential mammary grafts can be anticipated.

Adult↗
PubMed1988

Bacteriophages of lactobacilli.

Lactobacilli are members of the bacterial flora of lactic starter cultures used to generate lactic acid fermentation in a number of animal or plant products used as human or animals foods. They can be affected by phage outbreaks, which can result in faulty and depreciated products. Two groups of phages specific of Lactobacillus casei have been thoroughly studied. 1. The first group is represented by phage PL-1. This phage behaves as lytic in its usual host L. casei ATCC 27092, but can lysogenize another strain, L. casei ATCC 334. Bacterial receptors of this phage are located in a cell-wall polysaccharide and rhamnose is the main component of the receptors. Ca2+ and adenosine triphosphate (ATP) are indispensable to ensure the injection of the phage DNA into the bacterial cell. The phage DNA is double-stranded, mostly linear, but with cohesive ends which enables it to be circularized. The vegetative growth of PL-1 proceeds according to the classical mode. Cell lysis is produced by an N-acetyl-muramidase at the end of vegetative growth. 2. The second group is represented by the temperate phage phi FSW of L. casei ATCC27139. It has been shown how virulent phages originate from this temperate phage in Japanese dairy plants. The lysogenic state of phi FSW can be altered either by point mutations or by the insertion of a mobile genetic element called ISL 1, which comes from the bacterial chromosome. This is the first transposable element that has been described in lactobacilli. Lysogeny appears to be widespread among lactobacilli since one study showed that 27% of 148 strains studied, representing 15 species, produced phage particles after induction by mitomycin C. Similarly, 23 out of 30 strains of Lactobacillus salivarius are lysogenic and produce, after induction by mitomycin C, temperate phages, killer particles, or defective phages. Temperate phages have also been found in 10 out of 105 strains of Lactobacillus bulgaricus or Lactobacillus lactis after induction by mitomycin C. Phages so far studied of the latter 2 and closely related lactobacilli, either temperate or isolated as lytic, may be divided into 4 unrelated groups called a, b, c and d. Most of these phages are found in group a and an unquestionable relationship has already been shown between lytic phages and temperate phages that belong to this group. Lytic phage LL-H of L. lactis LL 23, isolated in Finland, is one of the most representative of those of group a and has been extensively studied on the molecular level.

Bacteriophages↗
PubMed1987

Radioimmunoguided surgery using the monoclonal antibody B72.3 in colorectal tumors.

The authors have developed a hand-held gamma-detecting probe (GDP) for intraoperative use that improves the sensitivity of external radioimmunodetection. Radiolabeled monoclonal antibody (MAb) B72.3 was injected in six patients with primary colorectal cancer and 31 patients with recurrent colorectal cancer an average of 16 days preoperatively. The GDP localized the MAb B72.3 in 83 percent of sites. The technique, known as a radioimmunoguided surgery (RIGS) system did not alter the surgical procedure in patients with primary colorectal cancer but did alter the approach in 26 percent (8/31) of patients with recurrent colorectal cancer. Two patients avoided unnecessary liver resections and two underwent extraabdominal approaches to document their disease. The RIGS system may influence the short-term morbidity and mortality of surgery for colorectal cancer. Larger series and longer follow-up are needed to determine whether the RIGS system confers a survival advantage to the patient with colorectal cancer.

Antibodies, Monoclonal↗
PubMed1987

Evidence for temperate bacteriophages in two strains of Lactobacillus bulgaricus.

Lactobacillus bulgaricus strains LT1 and LT4 previously isolated from a yogurt factory were shown to be lysogenic and inducible by mitomycin C or u.v. irradiation, induction being optimal at the beginning of exponential growth. Five indicator strains (four of L. lactis, one of L. bulgaricus) were found in which the two phage lysates propagated well in a liquid medium, but formed plaques on bacterial lawns less readily. Ca2+ was required for the phage infection of the indicator strains to reach termination. Phage particles from each strain exhibited a comparable ultrastructural morphology under the electron microscope, having an isometric head, a triple collar and a noncontractile fibre-containing tail.

Bacteriophages↗
PubMed1986

Intraoperative probe-directed immunodetection using a monoclonal antibody.

To assess monoclonal antibody (MAb) 17-1A and its F(ab')2 fragment in intraoperative radioimmunodetection and to evaluate further the clinical usefulness of a hand-held gamma-detecting probe (GDP), we injected radiolabeled monoclonal antibody 17-1A three to six days preoperatively or its F(ab')2 fragment two to three days preoperatively into 18 patients with colorectal cancer. Intraoperative GDP counts with tumor-tissue ratios of 1.5:1 or greater were obtained from 15 (75%) of 20 tumor sites, with ratios averaging 2.3:1 for fragments and 3.4:1 for whole antibody. The GDP counts contributed to intraoperative decision making in three patients, either by localization of tumor not identified by inspection or palpation or by mapping margins of resection with histologic confirmation of a local/regional recurrence. These preliminary data demonstrate that probe-directed, intraoperative radioimmunodetection can assist the surgeon in detecting subclinical tumor deposits and thus better evaluate the extent of primary or recurrent colorectal cancers intraoperatively.

Adult↗
PubMed1986

Periportal tuberculous adenitis: CT features.

The computed tomographic (CT) findings in six patients with periportal tuberculous adenitis were reviewed retrospectively to analyze the main morphologic features of the disease. In all patients, hypodense lymph nodes were observed close to the porta hepatis, with peripheral enhancement seen after administration of contrast material. In one patient, this hypodense adenopathy was associated with homogeneous, normally enhancing lymph nodes. These different features on the CT scans could signify the evolving pathologic stages of the disease, with early noncaseating granulomas and subsequent caseation necrosis. Recognition of these hypodense lymph nodes, especially in patients at risk, should help optimize the correct diagnosis of periportal tuberculous adenitis.

Adult↗
PubMed1984

Post traumatic spinal arachnoid cysts.

Based on the study of 10 cases of post traumatic spinal arachnoid cysts (SAC), acute and chronic clinical variants are individualized. A physiopathological hypothesis is advanced to explain their mechanism of formation. Acute SACs should be operated upon immediately although the differential diagnosis with spinal epidural haematomas is difficult. Even more difficult is the diagnosis of the chronic SAC. Rare though it may be, the Neurosurgeon must be aware of the possibility of its occurrence, especially when treating rather vague and stubborn cases.

Adult↗