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Biomedical subjects

J Kutti

Publications and source records attributed to J Kutti.

At least 127 records · Page 7Linked to original sources
PubMed1978

Experience of a platelet factor 3 immunoinjury technique in the detection of antiplatelet antibody in systemic lupus erythematosus and other clinical disorders.

Using a recently described platelet factor 3 (PF3) immunoinjury technique designed for the detection of antiplatelet antibody, sera from 62 patients were analysed. 30 of the subjects had systemic lupus erythematosus and the remaining 32 had other clinical disorders. Platelet survival studies were also carried out in every subject. The PF3 test proved positive in 10 of our patients. However, only 1 of these 10 subjects had shortened platelet survival. It is concluded that the PF3 test does not appear to be of use in the detection of circulating antiplatelet antibody.

Adolescent↗
PubMed1977

The relation between baseline and 150 min platelet counts in response to selective beta-1-receptor blockade. An experimental study on healthy subjects.

In 30 healthy volunteers after an oral administration of 50 mg metoprolol basal and 150 min platelet counts were determined. A significant negative correlation (p less than 0.01) between the baseline platelet count and the percentage increase at 150 min was shown to be present. It is postulated that this observation reflects interindividual differences between the magnitude of the exchangeable splenic platelet pool.

Administration, Oral↗
PubMed1977

Myelofibrosis and rapid thrombocytolysis. A case report.

A 69-year-old woman was referred to our department because of moderate anemia and thrombocytopenia. On admission the spleen was slightly enlarged. On the basis of histological examination of biopsy specimens from spinal processes the diagnosis of myelofibrosis was made. The subsequent clinical course was progressively downhill. Although splenomegaly was of only moderate degree, severe anemia and thrombocytopenia supervened. Platelet mean life span was dramatically shortened (1.8 hours) and platelet production rate considerably increased (about 18xnormal). Neither corticosteroid therapy nor splenectomy alleviated the thrombocytopenia. Extremely large platelets, with diameters of up to 10 mum, were seen in the peripheral blood. The mean platelet diameter and percentage of megathrombocytes reached peak values about 2 weeks after splenectomy. It is suggested that the immunologic background of the rapid thrombocytolysis is similar to that which governs platelet destruction in idiopathic thrombocytopenic purpura.

Aged↗
PubMed1977

The peripheral platelet count in response to intravenous infusion of salbutamol.

Five healthy male volunteers received i.v. infusions of salbutamol, a relatively selective beta-2-receptor-stimulating agent, in doses of 0.03, 0.06, 0.09 and 0.27 microgram X kg-1 X min-1 over a period of 6 min. At the three low doses the heart rate remained essentially unchanged and no significant decrease in the platelet count occurred. However, in response to 0.27 microgram X kg-1 X min-1 of salbutamol the heart rate increased by 25% over basal value (p less than 0.01) and a significant lowering (p less than 0.005) of the platelet count was obtained. The present findings suggest that the drop in the peripheral platelet concentration in response to adrenergic beta-receptor stimulation is mediated via beta-1-receptors.

Adult↗
PubMed1977

The exchangeable splenic platelet pool in response to selective adrenergic beta-i-receptor blockade.

The aim of the present work was to investigate the effect of selective beta-I-blockade on the exchangeable splenic platelet pool (ESPP). Therefore, 50 mg of metoprolol (a selective beta-I-receptor blocking agent) was given by mouth to three groups of subjects: (1) 15 healthy volunteers, (2) five asplenic subjects, and (3) 10 patients with different myeloproliferative disorders (MPD) with and without splenomegaly. The platelet count was determined 90, 150, 210, 270 and 330 min after the ingestion of the drug. In the group of healthy controls a significant increase (P less than 0.005) in the platelet count occurred and amounted to about 10% over baseline. The average peak value was reached at 150 min and the elevation in platelet count was maintained more than 4 h. An increase in the platelet count was also induced in patients with MPD, but the mean for the peak value only reached borderline significance (0.10 greater than P greater than 0.05). In the group of asplenic subjects no change in the platelet count occurred. It is concluded that acute oral administration of metoprolol causes a significant release of platelets from the ESPP. This platelet release is, however, no enhanced if the ESPP is enlarged.

Adolescent↗
PubMed1977

In vitro labelling of platelets. Experimental study on splenectomized patients with lymphomas using two different incubation media.

Duplicate platelet survival studies, using autologous platelets labelled in vitro with radioactive sodium chromate, were carried out on 5 lymphoma patients who had been splenectomized 14-21 months earlier. In the first experiment plasma was employed as the incubation medium and in the second a Ringer-citrate-dextrose (RCD) solution. The uptake of chromate by the platelets was 2.0 times higher in the RCD as compared to the plasma experiments. An identical pattern for the immediate behaviour of infused labelled platelets was observed in the duplicate studies, and the recovery of platelet-bound radioactivity remained stable at the 90% level during 2 h after infusion. In these experiments the means for platelet mean life span were almost identical, 5.4+/-0.6 and 5.3+/-0.5 days, respectively, and significantly (p less than 0.05) shorter than the mean for a control group consisting of 21 healthy males (6.9+/-0.3 days). It is concluded that RCD and plasma seem to serve equally well as incubation medium at the in vitro labelling of platelets.

Adult↗
PubMed1977

Metoprolol and the peripheral platelet count.

An acute oral administration of 50 mg metoprolol (a selective beta-1-receptor antagonist) to 18 healthy volunteers induced a significant increase in the peripheral platelet concentration lasting more than 4 h. It is suggested that this increment in the platelet count originates from the exchangeable splenic platelet pool. The mechanism by which metoprolol exerts its effect remains to be established.

Administration, Oral↗
PubMed1976

The peripheral platelet count in response to intravenous infusion of isoprenaline.

5 healthy male volunteers received i.v. infusions of isoprenaline in doses of 0.03, 0.06 and 0.09 mug X kg-1 X min-1 over a period of 6 min. A statistically significant decrease in the peripheral platelet count was obtained, but no dose-response-curve for isoprenaline was observed. It is suggested that while an i.v. infusion of epinephrine causes a release of platelets from the exchangeable splenic platelet pool, isoprenaline might have the opposite effect on the spleen, thereby causing a decrease of platelets in the peripheral blood.

Adult↗
PubMed1976

Thrombokinetics in systemic lupus erythematosus A preliminary report.

Twelve non-thrombocytopenic patients ( 3 males and 9 females) with systemic lupus erythematosus (SLE) were investigated with respect to platelet size, percentage of megathrombocytes, platelet survival and platelet production. The values for platelet size and percentage of megathrombocytes did not differ from those of a control group. In the SLE group the mean platelet MLS was identical to the control mean, and all patients with SLE had values for platelet MLS within the range of the control subjects. All SLE patients but one had values for platelet turnover within the control range. For unclear reason one single SLE patient had a moderately elevated platelet turnover value. The results of the present investigation do not support the theory that a state of compensated thrombocytolysis is present in SLE.

Adult↗
PubMed1975

In vitro labelling of platelets: an experimental study on healthy asplenic subjects using two different incubation media.

Duplicate platelet survival studies, using autologous platelets labelled in vitro with radioactive sodium chromate, were performed on six young healthy asplenic men. In the first experiment plasma, and in the second a Ringer-citrate-dextrose (RCD) solution (Abrahamsen, 1968), was employed as incubation medium. The uptake of chromate by the platelets was about 2.5 times higher in the RCD compared to the plasma experiments. An identical pattern for the immediate behaviour of infused labelled platelets was observed in the duplicate studies, and the recovery of platelet-bound radioactivity remained stable at the 90% level during 2 h post-infusion. In these experiments the means for platelet mean life span (MLS) were identical, 7.2 +/- 0.5 and 7.2 +/- 0.4 days, respectively. These values slightly, but not significantly, exceeded the mean platelet MLS for a control group consisting of 10 young healthy males (6.9 +/- 0.4 days). The means for platelet production rate (P) at the duplicate studies made on the asplenic subjects were 19 +/- 2 X 10(10) and 21 +/- 2 X 10(10) platelets per day, respectively, and did not differ from the mean for P obtained in the control group (22 +/- 2 X 10(10).

Adult↗
PubMed1975

The relation of thrombokinetics to bone marrow megakaryocytes in idiopathic thrombocytopenic purpura (ITP).

In 23 patients with untreated idiopathic thrombocytopenic purpura (TP), the relation of thrombokinetics to quantitative determinations of megakaryocytes in bone marrow sections was studied. The megakaryocytes were classified into maturation stages, and platelet sizes were determined. Megarkaryocyte number and volume per microliter of bone marrow were significantly higher in ITP as compared to controls. The megakaryocyte number and volume were inversely related to the peripheral platelet count. Platelet production rate was significantly increased in ITP and related to the megakaryocyte number and volume. The megakaryocytes were shifted towards more immature forms in ITP, suggesting an increased turnover rate of the expanded recognizable metakaryocyte compartment. Platelet size was significantly increased in ITP, and the mean platelet diameter was 1.6 times normal. There was a significant relationship between platelet size and platelet production rate, as well as an inverse relationship between platelet size and platelet mean life-span (MLS). There was also a significant correlation between platelet size and the proportion of young megakaryocytes.

Adolescent↗