Search PubMed⌕ Search

Biomedical subjects

E M Essien

Publications and source records attributed to E M Essien.

At least 37 records · Page 2Linked to original sources
PubMed1986

Carrier detection in hemophilia A: a cooperative international study. I. The carrier phenotype.

Eight laboratories in six countries cooperated to clarify several issues concerning the phenotypes of heterozygous carriers of hemophilia "A." Plasma levels of factor VIII (F.VIII:C, formerly VIII:C) and von Willebrand factor (VWF:Ag, formerly VIIIR:Ag) of carriers and normal women were determined by various "in-house" methods; a single lyophilized plasma standard was used for all assays. Analysis of the collated data from 336 carriers (296 obligatory carriers and 40 sporadic carriers) and 137 normal women showed that there was no difference in the F.VIII:C levels of "paternal" carriers (women who had obtained the abnormal gene from their fathers) and "maternal" carriers. Neither was there a difference in the VWF:Ag levels of normal women and either type of carrier. Age was found to have a significant effect on both F.VIII:C and VWF:Ag, values being higher at very young and very old ages, the minima occurring in the 25- to 30-year range. ABO blood type had a striking effect. Women of types A, B, and AB (designated non-O in the study), both normals and carriers, had significantly higher levels of both factors than did women of type O. Analysis by laboratories showed that differences in mean levels of both factors between laboratories were highly significant. It was concluded that age, ABO blood type, and laboratory variation should be taken into account in carrier detection.

ABO Blood-Group System↗
PubMed1986

Carrier detection in hemophilia A: a cooperative international study. II. The efficacy of a universal discriminant.

Factor VIII (F.VIII) and von Willebrand factor (VWF):Ag data collected by eight laboratories on a total of 336 obligatory carriers of hemophilia A and 137 normal women were used to answer several questions concerning the construction of linear discriminants for carrier detection. It was found: that a "universal" linear discriminant can be constructed which is suitable for use in all laboratories and is nearly as effective as laboratory-specific discriminants; that inclusion of age and ABO blood type data improved the efficacy of these discriminants; that substitution of alternative assays for F.VIII and VWF:Ag did not generally improve the efficacy of the discriminants over that obtained using the bioassay for F.VIII:C and Laurell's immunoassay for VWF:Ag; that linear discriminants were far more effective than discriminants based on the F.VIII:C/VWF:Ag ratio. A step-wise procedure is given which any laboratory may follow in using the universal discriminant for carrier detection.

ABO Blood-Group System↗
PubMed1985

The inhibitory effects of ferriprotoporphyrin IX on platelet aggregation and release of serotonin.

Ferriprotoporphyrin IX (FP) dissolved in 0.025N NaoH in concentrations of 0.01 - 0.04 microM/ul platelet suspension competitively inhibited platelet aggregation induced by a low concentration of collagen. 14C-serotonin release was also inhibited. Higher concentrations of collagen overcame the aggregation inhibition. A similar pattern of results was obtained with thrombin-, and arachidonic acid-induced aggregation and release. With ristocetin, there was little inhibition of aggregation although serotonin release was inhibited. ADP-induced aggregation was partially inhibited except at FP concentrations of 0.91 microM/mul. FP caused only platelet shape change and serotonin release of up to 8.1%. These changes were not associated with significant platelet lysis and could also not be attributed to pH or temperature changes. There was no inhibition of collagen-induced aggregation in PRP, but FP precipitates aggregated washed platelets and caused serotonin release. These results show that FP in solution inhibited platelet aggregation induced by the different agents studied. It did not interfere with platelet agglutination induced by ristocetin. The mechanism(s) of aggregation inhibition remains to be clarified.

Adult↗
PubMed1984

Blood changes and enhanced thromboxane and 6-keto prostaglandin F1 alpha production in experimental acute Plasmodium bergei infection in hamsters.

Golden hamsters inoculated intraperitoneally with Plasmodium bergei infected mouse blood regularly developed P. bergei parasitaemia. This was associated with progressive thrombocytopenia and leucocytosis as the degree of parasitaemia increased with time. When infected whole blood was stimulated with collagen, significantly enhanced thromboxane B2 (TXB2) production per platelet was seen. 6-keto prostaglandin (PG) F1 alpha formation in the same system increased from the sixth infection day onwards and correlated with the relative leukocytosis. The production of 6-keto PGF1 alpha by aorta rings was significantly higher during the 4-7th days postinoculation. The increase in thromboxane production however was much more important than that of 6-keto PGF1 alpha and it therefore is concluded that P. bergei parasitaemia in hamsters tilts the haemostatic balance towards the platelet hyperaggregability that has also been described in P. falciparum infection in man.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Platelet secretory activities in acute malaria (Plasmodium falciparum) infection.

During acute Plasmodium falciparum infection in man, plasma concentrations of platelet-specific proteins, beta-thromboglobulin (beta TG) and platelet factor 4 (PF4) were significantly elevated. For beta TG, the mean concentration was 136.24 +/- 71.58 ng/ml in patients, and 50.53 +/- 25.42 ng/ml in control subjects (t = 5.3794; p = 0.0001), while for PF4 mean values were, respectively, 75.35 +/- 23.09 and 18.64 +/- 13.42 ng/ml (t = -6.0897; p less than 0.0001). Platelet LDH loss in vitro in response to stimulation with 0.5 U of thrombin was 57.0 +/- 29.5% in patient samples and 24.8 +/- 16.9% (control); the values being significantly different from each other (t = 2.888; p less than 0.025). With serotonin (5HT) uptake and release however, the values were essentially normal, in spite of marginal difference observed in the uptake value of patients compared to control. The data indicate that there was in vivo platelet activation during the infection, with the haemostatic balance titled towards hypercoagulability. There was also associated easy platelet lysis with stimulation. It is also suggested that the latter finding may be one of the mechanisms of reduced circulating platelet numbers observed in patients in the acute disease.

Beta-Globulins↗
PubMed1982

Management of leukaemia-associated disseminated intravascular coagulation (DIC).

Seven patients presenting with DIC in association with acute promyelocytic and myelomonocytic leukaemia were treated with intensive chemotherapy (IC), intensive platelet support (IPS) and continuous heparinization (CH), or IC + CH but minimal platelet support (MPS), or no chemotherapy, no heparin or MPS. All four patients who received IC + IPS + CH achieved remission (survival time: 516, 400+, 371 and 368 days). The remaining three patients died early (survival time: 11, 7 and 3 days). The results suggest that a combination of IC + IPS + CH is essential in the management of leukaemia-related DIC.

Adolescent↗
PubMed1981

Platelet hypersensitivity in acute malaria (Plasmodium falciparum) infection in man.

During acute malaria infection, platelets in human platelet-rich plasma re hypersensitive to the addition of ADP between 1.0 micro M and 5.0 micro M, or adrenaline 0.11 micro M as aggregating agents. The mean maximum aggregation amplitude (as % of light transmission) obtained from 8 subjects in response to added ADP (1.0 micro M) , 39.8 +/- 27 (1SD), was significantly greater than the value in 6 controls (5.2 +/- 6.7 (1SD); t = 3,51 P less than 0.005). A similar pattern of response was obtained with higher ADP concentrations (2,4, 4.5 or 5.0 micro M) in 22 patients and 20 control subjects (89.9 +/- 14.9 % vs 77.8 +/- 16.5% (1SD) t = 2,45, P less than 0.02). Addition to 4.5 microM ADP to patient PRP usually evoked only a single aggregation wave (fused primary and secondary waves) while the typical primary and secondary wave pattern was usually obtained from controls. Mean plasma B-thromboglobulin (BTG) concentration in 7 patients (208.3 +/0 15.6 ng/ml) was significantly higher than the value in 6 control subjects (59.2 +/- 15.7 ng/ml; t=13.44, P less than 0.002).

Adenosine Diphosphate↗
PubMed1978

Factor VIII coagulant activity in an African population in relation to a recognized standard.

The normal range of factor VIII coagulant activity (derived from log potency ratio) in some sections of the Nigerian population has been established at 0.65--5.55 iu/ml with a geometric mean of 1.90 iu/ml. This was determined against an acceptable standard (MRC Human 68/413 with activity o.66 iu/ml). The distribution of the potency ratio was log normal. The level was not affected by age or an abnormal haemoglobin (Hb A + S or A + C). The mean activity in females was significantly higher than the mean value in male subjects. With the use of a stable standard, our results show that the conclusions of some previous studies in respect of some of the parameters such as population distribution but which did not use a recognized standard, were valid. Within the age limits of our subjects, age did not affect the population level of factor VIII coagulant activity.

Adolescent↗
PubMed1977

Inhibition of platelet adhesion to rabbit aorta by sulphinpyrazone and acetylsalicylic acid.

A technique for the isolation of rabbit thoracic aorta in a form in which it can withstand normal pressure and a new in vitro system in which it was tested is described. Segments of aorta were selectively damaged with a balloon catheter by the Baumgartneer technique and supensions of washed platelets, labelled with 51Cr, were perfused through them. More platelets adhered to the damaged surface than to the undamaged surface. Suophinpyrazone was more effective than aspirin in inhibiting platelet adherence to both the damaged and undamaged surface.

Animals↗
PubMed1977

Fletcher factor deficiency--detection of a severe case in a population survey.

The first case of Fletcher factor deficiency from the African continent is described. This was the only case of symptomatic Fletcher factor deficiency detected in a total population survey of 40,522 persons. This patient differs from other reported cases in that the child had symptoms of severe bleeding defect such as recurrent haemarthrosis and haematoma. The clinical features appear to improve with age. Both the PTT 'time course' and cold-induced EACA acceleration of the thromboplastin time are useful diagnostic tests for detecting homozygous patients. Our results confirm an earlier report that the EACA test is a sensitive test for detecting heterozygotes.

Blood Coagulation Disorders↗
PubMed1977

Changes in antithrombin III levels in pregnancy, labour and in women on the contraceptive pill.

Antithrombin III activity as determined by the modified Mancini technique is reported for the first time in different groups of Nigerian women as well as in a group of male blood donors. The mean level of activity (78.69%) observed in women during their second and third trimesters was lower than the mean value in the same group of women at parturition (93.18%) and significantly lower than a control group of non-pregnant women who were also not on the contraceptive pill (109.67; P less than 0.05). There was no significant difference between the mean activity of the female control group and that of women on the contraceptive pill and that of a group of male blood donors of the same age range.

Adolescent↗
PubMed1976

Effect of the root extract of Fagara zanthoxyloides on blood coagulation.

The clot-promoting activity of the aqueous extract of Fagara-zanthoxyloides Lam plant is described for the first time. It significantly shortened the PTT (K) of normal and factor VIII deficient plasma while it manifested no such action on factor IX-deficient plasma. This activity could be demonstrated in the residue of the lyophilized aqueous extract after its successive extraction with ether, chloroform and methanol. It could not be attributed to the purified fractions: Zanthoxylol or its modified form 3, 4-dihydro-2,2-dimethyl-2H-1 benzopyran-6-butyric acid (DBA), hesperidin, Fagaramide or the ether soluble fraction of the aqueous extract.

Blood Coagulation↗
PubMed1976

Coagulation defect in experimental trypanosomial infection.

Some coagulation parameters have been studied in animals experimentally infected with trypanosomial organisms (T. brucei or T. congolense). The partial thromboplastin time test with kaolin was regularly abnormally prolonged in all animals during infection. Although results of some coagulation factors in the intrinsic pathway cannot be used to explain this finding, it is suggested that the partial thromboplastin time test can be used as a test to monitor infection and recovery from this organism.

Animals↗