PubMed Health⌕ Search

Biomedical subjects

M Lessard

Publications and source records attributed to M Lessard.

At least 73 records · Page 4Linked to original sources

Cellular immune responses in pigs fed a vitamin E- and selenium-deficient diet.

The effects of dietary restriction of vitamin E (Vit E) and selenium (Se) on lymphocyte proliferation, natural killer (NK) cell activity, antibody-dependent cell-mediated cytotoxicity (ADCC), and on burst respiratory response of stimulated granulocytes as measured by chemiluminescence (CL) were studied in pigs. Six male weanling pigs were maintained for 25 d on a torula yeast-based diet containing no measurable amount of alpha-tocopherol and less than .02 mg of Se per kilogram of feed. Six others received the same basal diet supplemented with 33 IU of DL-alpha-tocopheryl acetate and .2 mg of Se per kilogram of feed. All pigs were inoculated with Salmonella typhisuis on d 21 of the feeding period and killed on d 25. Tests to measure cellular immune functions were performed on cells isolated from blood samples taken on d 21 and 25. After 21 d of feeding, lymphocyte blastogenesis responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen in pigs fed the Vit E- and Se-deficient diet were normal compared with the response in pigs fed the supplemented diet. Moreover, the cytotoxic activity of NK cells, the ADCC response, and the CL response of granulocytes were not affected. After 25 d, a marked suppression of lymphocyte response to mitogens occurred in pigs fed the Vit E- and Se-deficient diet when the cells were cultured in the presence of autologous serum. When fetal bovine serum replaced autologous serum in the cultures, no suppression was observed. No effect on NK activity and ADCC was observed, whereas the CL peak response of granulocytes tended to be higher in pigs fed the deficient diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Evaluation and prognosis of fetal arrhythmia].

From January 1986 to August 1990, a fetal arrhythmia was diagnosed in 97 pregnant women referred to our unit. Atrial or ventricular extrasystoles were the most frequent rhythm disturbance encountered (71%). They were always well tolerated and all disappeared during the perinatal period. Tachycardia was found in 16 fetuses; 6 had a supraventricular reentrant tachycardia, 6 an atrial chaotic tachycardia, 1 an ectopic atrial tachycardia and the remaining 3 an atrial flutter. A congenital heart malformation was present in 4 fetuses. The arrhythmia induced hydrops fetalis in 25% of cases. One hydropic fetus died in utero and another needed premature delivery. Bradycardia was diagnosed in 12 cases, 3 had benign atrial blocked extrasystoles, 3 others sinus bradycardia due to fetal distress and 6 atrio-ventricular block. Atrio-ventricular block was associated with congenital malformation in 4 cases (66%). All these fetuses were hydropic and died. The 2 fetuses without cardiac malformation tolerated well their bradycardia during fetal life. Fetal arrhythmia is not rare, but in most cases is benign. Sustained tachycardia requires prompt treatment, because when hydrops fetalis appears the prognosis is worse. The major prognostic factor for atrio-ventricular block is the association with a cardiac malformation.

Arrhythmias, Cardiac↗

Chronic myelocytic leukaemia with unusual (27 years) complete remission terminating in acute undifferentiated leukaemia: a clinical and karyotypic study.

A case of clinically typical CML (300 x 10(6)/l leukocytes, 400 x 10(6)/l platelets, splenomegaly) is presented. After complete remission induced by busulphan, no clinical or haematological abnormalities were observed for 27 years until the development of acute leukaemia (type M1), which was rapidly fatal after a brief chemotherapy-induced remission. The cytogenetic findings were also original: no chromosome Ph1 (during remission 3 years after the onset of the disease), no translocation (banding study 5 years later), and no bcr/abl rearrangement (during the terminal phase).

Busulfan↗

[Acute leukemia with translocation (8;16)].

Three cases of M5 acute leukemia, 1 with a t(8;16)(p11;p13), 2 with variant translocations, both with a breakpoint at band 8p11, t(6;8)(q27;p11) and t(8;19)(p11;q13) are reported and 12 other published cases reviewed. This is a rare new entity, of variable but rather poor prognosis, seen from birth to 75 years of age, with several cases in infants. Leukemic cells, which often show conspicuous phagocytic activity on bone marrow smears, bear both monocytic and granulocytic markers in at least some cases. The best therapeutic regimen is not well-defined. The molecular basis of the disorder remains to be elucidated.

Adult↗

[Rearrangement of the short arm of chromosome 12 in chronic myelomonocytic leukemias].

A rearrangement of the short arm of chromosome #12 with a breakpoint at band 12 was found in 4 out of 15 patients with CMML: two deletions, one simple translocation (9;12)(p21;p12) and one complex t(11;12;13)(p11;p12;q21). Their haematological and clinical characteristics were investigated together with those of 5 other similar published cases. Although this alteration is not very frequent in this myelodysplastic syndrome, and is also found in various other malignant blood disorders, it is clearly a non-random phenomenon, the consequences of which are discussed.

Chromosome Aberrations↗

Massive ovarian edema in a twin pregnancy.

A case of idiopathic ovarian edema in a 26-year-old woman with a twin pregnancy is reported. The clinical evolution of the condition was benign in spite of acute episodes of left iliac pain. In diagnosis, theca-lutein cysts had to be differentiated from other ovarian enlargements. The authors advise conservative surgery for such a condition.

Adult↗

[Massive sarcomatous infiltration of the liver disclosed by jaundice and hepatocellular failure in Waldenström's disease].

We report herein the case of a patient with Waldenström macroglobulinemia in whom an immunoblastic sarcoma produced acute jaundice and hepatic failure. Transvenous liver biopsy, performed because of coagulation deficiencies, revealed massive infiltration of the liver by the sarcoma. Immunofluorescence study showed numerous portal and sinusoidal cells stained exclusively by anti-micron anti-kappa antisera. As shown by others in the literature, this study supports evidence for the same clonal origin of the two proliferations. Chromosomal abnormalities were found in marrow and blood cells (trisomy 5 and 20, 6 q-, 7 q+, and 8 p-); their role in emergence of sarcoma is discussed. This case shows that immunoblastic sarcoma emerging during the course of Waldenström macroglobulinemia may be revealed by severe hepatic manifestations.

Aged↗

Cytogenetic studies in 56 cases with Ph1-positive hematologic disorders.

Karyotypes were examined in 56 cases of Ph1-positive hematologic disorders based on direct examination of bone marrow material and culture of blood for 24 hr without phytohemagglutinin (PHA). Various banding techniques (Q, followed by R or C, where necessary) were used. The series of patients consisted of 21 females and 35 males with the ages ranging from 3 to 72 years. In three cases, the clinical and hematologic picture at the time of diagnosis and karyotyping was not compatible with chronic myeloid leukemia (CML): 1 case had acute myeloblastic leukemia (AML), another acute lymphoblastic leukemia (ALL) and the third subacute myeloid leucosis. The results are as follows: In three cases (two female, one male), no Ph1 translocation could be demonstrated in any of the metaphases either with Q- or R-banding. In 50 cases (19 female, 31 male), a standard Ph1 translocation, t(9;22)(q34;q11), was observed. In two of these cases, ages 45 and 47, the Ph1 translocation was accompanied by loss of the Y chromosome in all the metaphases examined. Finally, in three cases (all male), variant Ph1-translocations were found: t(7;9)(9;22)(q35?;q31?;q11), and t(1;9)(9;22)(q21;134;q11).

Adolescent↗

[Karyotyping in chronic myeloproliferative syndrome (except chronic myeloid leukemia)].

Cytogenetics studies in chronic myeloproliferative disorders have brought evidence of acquired chromosomal abnormalities. Some markers are frequently seen: = 1 partial trisomy, with numerous varieties, = 7 monosomy, = 8 trisomy, = 9 trisomy, = 20 long arm deletion (20q-), and less often: iso 17q, Dq-, 6p-, 21q-. Cytogenetics studies performed during active therapy have shown various abnormalities, probably therapeutic-related. Prospectives studies are useful in order to estimate the frequency and significance of karyotype variation.

Chromosome Aberrations↗

Unusual translocation and chronic myelocytic leukemia: "masked" Philadelphia chromosome (Ph 1).

An unusual Ph 1 translocation in a woman, 65 years old, with chronic myelocytic leukemia is reported. Cytogenetic analysis performed on 150 mitoses examined with Q-, R-, and C-banding revealed evidence for an unusual translocation involving the insertion of a segment of chromosome #9 into chromosome #22, thus masking the presence of a Ph 1. The anomaly can best be described as 46, XX, ins(22;9) (q11;q22 to 34).

Aged↗