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Biomedical subjects

S Allard

Publications and source records attributed to S Allard.

At least 73 records · Page 4Linked to original sources
PubMed1988

Heterogeneity of T cell receptor idiotypes in rheumatoid arthritis.

The nature of the T cell response in the rheumatoid synovium was investigated by using monoclonals MX9 and 42/1C1, which recognize the V beta 8 and V beta 5 T cell receptor gene families respectively. The blood and synovial T cells of ten patients with rheumatoid arthritis were compared. The majority (8/10) had different numbers of V beta 5 and V beta 8 cells in the joints from those in the blood, indicating that the T cells in the joints were not a sample of those in the blood. In three patients both V beta 5 and V beta 8 cells in the joint were augmented in number, suggesting that the T cells selectively retained in the joint were not members of a single clone, but derived from many clones. Some patients had increased levels of V beta 5 or V beta 8 alone in the joint indicating that heterogeneity existed between patients. These results are not consistent with the preferential or dominant use of a single V beta gene family in the T cells involved in the rheumatoid arthritic joints.

Arthritis, Rheumatoid↗
PubMed1987

A hospital team approach with parents of a Down's syndrome infant.

This article is a description of a multidisciplinary team approach with parents of a Down's syndrome infant in the obstetrical department of the Royal Victoria Hospital in Montreal. After a brief explanation on the reason why a refinement of this approach became necessary, the authors give an account of the in-service training that was implemented for professionals as well as some comments on parents' initial reactions to the birth of a Down's syndrome child and the role of professionals in these situations. Finally, a "Protocol for management of Down's syndrome infants in hospital" is included in the last part of the article.

Clinical Protocols↗
PubMed1987

Surgical treatment of bronchogenic carcinoma: the importance of staging in evaluating late survival.

From 1971 to 1980, 1292 patients with lung cancer were admitted to the Hôpital du Sacré-Coeur de Montréal. This diagnosis represented 0.5% of admissions in 1971 and 1.7% in 1980 (240% increase). Only 4% of patients were nonsmokers. Patients ranged in age from 30 to 93 years with a male to female ratio of 5.5 to 1. Of 414 cervical mediastinoscopies carried out for right and left pulmonary tumours, 120 (29%) showed mediastinal lymph-node metastasis (positive biopsy). For 35 left-sided lesions, both cervical and left parasternal mediastinoscopies produced 13 (37%) positive biopsies. For 45 left upper lobe and left hilum tumours, left parasternal mediastinoscopy alone yielded 18 (40%) positive biopsies. Only 297 (23%) of the 1292 patients were considered to have operable lesions and they underwent thoracotomy - 164 (55%) lobectomies, 104 (35%) pneumonectomies, 2 (1%) segmentectomies and 27 (9%) exploratory thoracotomies. The most common postoperative complication was respiratory failure - in 27 cases (9%); there were 12 (4%) bronchopleural fistulas. The operative death rate was 5% - 1.8% for lobectomy, 7.4% for exploratory thoracotomy and 9.6% for pneumonectomy. Causes of death were respiratory failure (60% of the deaths), hemorrhage (13%), cardiac events (13%) and bronchopleural fistula (13%). The overall 5-year survival was 9.2%. For the 297 patients operated on, the survival at 5 and 10 years was 55% and 36% for stage I disease, 30% and 20% for stage II disease and 10% and 8% for stage III disease, respectively. The mean postoperative follow-up was 41.5 months (range from 3.5 to 14 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Renal brush border membrane phosphorylation: influence of pH, cAMP and ATP concentrations, parathyroid hormone status, and dietary phosphate.

It is known that parathyroidectomy, administration of parathyroid hormone (PTH), and dietary phosphate depletion or excess result in variations in phosphaturia and in phosphate transport through brush border membrane vesicles isolated from the kidneys of various animals. Parathyroid hormone has been shown to ultimately phosphorylate some brush border membrane proteins and it has been postulated that the resulting phosphaturia is related to this phosphorylation. However, it is not known whether the regulation of phosphate transport by the diet is affected through similar pathways. Our experiments were designed to study the phosphorylation of brush border membrane with [gamma-32P]ATP using the intrinsic protein kinase of the membranes. Five groups of rats were used: normal, phosphate loaded, phosphate depleted, and thyroparathyroidectomized and acutely loaded with parathyroid hormone. In each series of animals, the proteins whose phosphorylation was cAMP dependent were detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and their phosphorylation with various concentrations of ATP, in the presence or absence of cAMP in the incubation medium, was quantified. In the normal rat, 17 proteins were phosphorylated, the phosphorylation of two of them (Mr, 71 000 and 84 000) being cAMP dependent. Maximal response to cAMP for these two proteins was obtained with 10 microM cAMP. The peaks of phosphorylation were observed at pH 7 for protein 71 000 and pH 10 for protein 84 000. When brush border membranes from normal rats were incubated with 10-100 microM ATP, cAMP-dependent phosphorylation increased to reach a maximal phosphorylation of 4.44 +/- 0.90 pmol/mg protein for protein 71 000 and 1.32 +/- 0.15 pmol/mg protein for protein 84 000.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1985

Phosphate uptake by syncytial brush border membranes of human placenta.

Human placental brush border membranes were obtained from full-term normal vaginal deliveries. A sodium dependent transport system for phosphate was identified in these membranes. In the presence of a sodium gradient, at pH 7, T degree 35 degrees C, the apparent Km and Vmax were 86.5 +/- 24 microM and 1.9 +/- 0.18 nmol mg-1 30 s-1. The apparent Km was pH dependent, increasing to 500 +/- 55 microM when the pH was elevated to 8.5. At low substrate concentration, the optimal uptake was obtained at pH 7.0. Both monovalent and divalent forms of phosphate were transported so that alteration in the transport by pH is believed to be the result of a direct action on the transport system. Finally, sodium levels in the incubation medium dramatically influenced phosphate uptake by increasing the maximal velocity without modifying the affinity for the substrate. This active transport through the placental brush border membranes is believed to be at the origin of the maternal-fetal gradient of phosphate observed during pregnancy.

Biological Transport, Active↗
PubMed1984

Renal brush border membranes from mice with X-linked hypophosphatemia: protein composition, phosphate binding capacity, and protein kinase activity.

Phosphate uptake by brush-border membrane (BBM) vesicles prepared from hypophosphatemic mice (Hyp) is reduced by half relative to BBM vesicles from normal mice. To investigate this abnormality, we studied the protein composition of BBM, their capacity to bind inorganic phosphate, and their protein kinase activity with and without the addition of exogenous cAMP, in normal and Hyp mice. Gradient polyacrylamide gel electrophoresis of BBM proteins showed 27 bands which were identical in normal and Hyp mice. Incubation of the membranes with ortho[32P]phosphate at 0 degrees C revealed a phosphate binding protein with an apparent molecular weight (Mr) of 79000, which has been previously identified in rats as the monomer of alkaline phosphatase. In normal mice, the Scatchard plot of phosphate binding was not linear, suggesting heterogeneity of the binding sites with two major components. At high substrate concentrations, the affinity (K) was 1.42 mM and maximal binding (Bmax) was 83 pmol/mg protein. At low substrate concentrations, these values were 0.07 mM and 10.9 pmol/mg, respectively. In Hyp mice BBM, only one binding system was found with K and Bmax values of 0.38 mM and 53.8 pmol/mg. Incubation of the membranes with 25 microM[gamma-32P]ATP resulted in the phosphorylation of 11 proteins. The major band (Mr: 79000) corresponded to the inorganic phosphate binding protein, i.e., to the alkaline-phosphatase monomer. The 11 proteins showed maximal phosphorylation at pH 10. The protein of 79000 Mr showed a second peak of phosphorylation at pH 7.5.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1983

Temporal control in a complex environment: An analysis of schedule-related behavior.

Three experiments conducted in an automated ten-compartment chamber recorded collateral activities of rats reinforced for lever pressing on differential-reinforcement-of-low-rate schedules. In Experiment 1, the rate of lever pressing increased when stimulus support for collateral activities was removed, thus confirming earlier findings. However, there were no temporal or sequential patterns of collateral activities that predicted operant responding. In Experiment 2, the rate of lever pressing increased only if (a) access to all stimulus support for collateral activities was simultaneously prevented, and (b) the rat was forced to remain in the presence of the lever and food tray. The availability of any of the stimuli related to collateral activity was sufficient to keep lever-pressing rates from increasing. Experiment 3 examined collateral activities under a signaled differential-reinforcement-of-low-rate schedule. Preventing access to stimuli supporting collateral activities had little effect on stable lever pressing when the signal was maintained. When the signal was removed, collateral activities continued, but lever-pressing rates increased in three of the four rats and rates of food presentation declined in all rats. Hypotheses that collateral activities have (a) a timekeeping or discriminative function, or (b) directly inhibit operant responding were not supported. The results suggest that collateral activities may facilitate operant responding by simply removing the subject from the presence of reinforcement-related stimuli.

Journal Article↗
PubMed1981

[Intestinal malabsorption with a dissociated deficiency of immunoglobulins (author's transl)].

The case of a 42-year-old-man with dissociated deficiency of immunoglobulins and intestinal malabsorption is presented. The gastrointestinal symptoms included post-prandial pains and steatorrhea. Histologic and immunohistochemistry studies of small intestinal biopsies revealed subtotal villous atrophy and absence of IgA producing plasma cells. The deficiency of immunoglobulins was total for IgA and moderate for IgM. IgG was increased. HLA B8 haplotype was present Gluten-free diet gave dramatic improvement in few days on clinic symptoms. Recovery of the villi was observed within three months. The cases reported in the published literature are reviewed and the physiopathologic hypothesis and nosology limits of the syndrome are discussed.

Adolescent↗
PubMed1980

[Dermatofibrosarcoma protuberans developing for 25 years with 27 recurrences. Histological and ultrastructural study].

The authors report the results of a histological and ultrastructure study of a case of a protuberant dermatofibrosarcoma evolving for the last 25 years with 27 relapses. Histologically the tumour is dermic, non-encapsulated, invading the hypodermis right from the beginning and mainly made up of fusiform cells which often have a storiform appearance and proliferate in a varying degree of collagenous stroma which includes an oedematous or myxoid component. During the course of the evolution of this tumour, there were zones of cystic degeneration, but in the last 10 relapses in 1978 and 1979, we noted the predominance of cellular and compact zones with an increase in the number of mitoses. The ultrastructure study showed tumour cells containing a fairly well developed endoplasmic reticulum in the cytoplasm, a prominent Golgi apparatus and some pinocytic vesicles. Some of the cells also contained lysosomes and phagolysosomes, whereas others contained cytoplasmic filaments and contractile elements. The nuclei were in general elongated and irregular. Sometimes the cytoplasmic membrane was covered by an amorphous substance with a membranoid appearance. Between the cells sometimes there were junctions of the tight kind. In conclusion, the authors consider that this tumour has the histological characteristics of a protuberant dermatofibrosarcoma and at the ultrastructure level, it is made up of cells which put it in the group of myofibroblastic and histiocytic proliferating lesions.

Fibroma↗
PubMedDate not supplied

[Alcoholism, colic diverticular disease and metabolic disorders (author's transl)].

70 patients with colic diverticular disease and 50 control subjects were compared. Sexes and ages were matched in the two groups. Significant higher frequencies of alcoholism (P < 0,00001), hyperlipidemia (P < 0,0001), impaired oral glucose tolerance test (P < 0,001), hyperuricemia (P < 0,01) and atherosclerosis (P < 0,000001) were noted in the diverticular group. Hypothesis about pathogenesis of diverticular disease are suggested.

Adult↗