摘要:

AbstractSnake venoms contain compound(s) that enhanced cyclic AMP content in human mononuclear leukocytes maximally after 5 min of incubation at 37°C. The effect was time‐ and dose‐dependent. The half‐maximal stimulation of cyclic AMP production by black cobra venom was found at 0.45 μg of venom/ml and the value of the Hill coefficient was 0.7. The black cobra venom enhanced the cyclic AMP content in the cells at 4, 22, and 37°C. Similar increase in the cyclic AMP content by six snake venoms was found in human polymorphonuclear leukocytes. The most active venom was from puff adder (Bitis arietans). The data suggest that one of the effects of the snake venoms may be rapid enhancement of cyclic AMP level in the affect

ISSN:0361-8609    

DOI:10.1002/ajh.2830170202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThree generations of a Jewish family with hereditary thrombocytopenia (HT) are described. The disease was manifested clinically by mild bleeding tendency since infancy. Circumcision, however, did not result in excessive bleeding. HLA study in this family indicated that the HT locus is not linked to HLA.

ISSN:0361-8609    

DOI:10.1002/ajh.2830170203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractMany recent studies provide evidence that increased platelet activation occurs in a significant number of patients with atherosclerotic coronary artery disease. The mechanisms responsible for this activation are unknown, although there have been studies suggesting a correlation with abnormal lipoproteinemia, acute myocardial infarction, unstable angina, and exercise‐induced myocardial ischemia. We studied 84 patients undergoing standardized treadmill exercise using either a Bruce [N = 63] or symptom‐limited Naughton protocol [N = 21]. In contrast to ten healthy volunteer subjects, the patient group demonstrated a significant increase in plasma concentrations of platelet factor 4 [PF4] between pre‐ and postexercise blood samples confirming earlier reports of exercise‐induced platelet activation and secretion. As with previous studies, however, only a subset of patients demonstrated this response. When the entire group was analyzed for the presence or absence of electrocardiographic ischemic changes and the presence of documented versus suspected coronary artery occlusions, there were no differences noted between groups that explained the variable responses measured. However, there was a significant difference between patient groups when analyzed by whether or not they were being treated with β‐blocking agents. Patients who were being treated with propranolol or one of the longer‐acting β‐blocking agents did not have a significant increase in plasma PF4 following exercise, in contrast to patients who were not β‐blocked. Plasma concentrations of epinephrine, norepinephrine, and lactic acid were measured in 49 patients and all normal subjects. There was no correlation between the changes in plasma PF4 concentrations and any of these three variables, suggesting that platelet activation was not occurring through direct platelet activation by circulating catecholamines. This study provides further evidence that there is a subset of CAD patients with platelet hyperactivity. This is the first time that β‐blockade has been demonstrated to modify this platelet response. The effectiveness of β‐blocking agents in CAD may be in part related to t

ISSN:0361-8609    

DOI:10.1002/ajh.2830170204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractA possible mechanism of the formation of microspherocytosis in unsplenectomized patients with hereditary spherocytosis (HS) was investigated in relation to lipid metabolism in plasma and in red cells of these patients. Plasma lipids (total cholesterol, free cholesterol, high density lipoprotein cholesterol, free fatty acids, and phospholipids) were markedly reduced in unsplenectomized HS patients with microspherocytosis. Red cell membrane lipids (free cholesterol and phospholipids such as phosphatidyl ethanolamine, sphingomyelin, phosphatidyl choline, and lysophosphatidyl choline) were also decreased in these unsplenectomized HS patients. After splenectomy, microspherocytosis disappeared concomitant to substantial normalization of plasma and red cell membrane lipids. These observations suggest that plasma lipid decrement in the unsplenectomized HS patients is at least one of the causative factors in pathogenesis of the formation of microspherocytosis. So‐called “splenic conditioning” may not imply a physical “loss” of membrane by fragmentation or pitting of the once‐formed HS red cells in the peripheral circulation. Instead, the decreased plasma lipids in the presence of the spleen may affect the de novo synthesis of red cell membrane lipids, resulting in the formation of microsp

ISSN:0361-8609    

DOI:10.1002/ajh.2830170205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe distribution within the body of autologous leukemic cells labeled with indium‐111 oxine was studied in seven patients with acute nonlymphocytic leukemia. The leukemic blood cells initially entered the spleen and liver, and the major site of localization was the former rather than the latter. The majority of the leukemic cells had not left the spleen and liver within 48 hr. Liver radioactivity fell transitorily up to the third hr after the initial rise. The clearance curve of radioactivity from the blood showed a plateau or the appearance of a “hump” from 1 to 5 hr after injection of labeled leukemic cells. These results might reflect recirculation of a portion of the leukemic cells between these organs and the bloodstream. In a patient with acute monoblastic leukemia, OKMl monoclonal‐antibody‐treated monoblasts showed the lowest recovery into the blood and a greater increase of liver than splenic radioactivity at 30 min after injection. These results suggest the removal of damaged cells by the cytotoxic effects of antibody mediated by reticuloendothelial clearance mainly of the liver and others. In one patient with acute promyelocytic leukemia, leukemic cells accumulated in both kidneys, indicating the possible infiltration of these cells. Since indium‐111 oxine stays firmly attached to the cells in spite of the possibility of radiation damaged in a long‐term survey, it seems an ideal label for studying leukemic

ISSN:0361-8609    

DOI:10.1002/ajh.2830170206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractWe have examined the effects of a novel platelet agonist, platelet activating factor (PAF), on human platelets. Irreversible aggregation and14C‐serotonin secretion in response to PAF (10−5M) was found to be dependent on both thromboxane production and secreted adenosine diphosphate (ADP). Liberation of arachidonic acid (AA) from membrane‐bound phospholipids is a prerequisite step in platelet thromboxane production. Studies with3H‐AA‐labeled platelets revealed that PAF (10−5M) was a weak stimulus for the mobilization of AA. In addition, PAF (10−5M) was found to be a weak inducer of thromboxane synthesis (mean = 6 pmol/108platelets) as compared to thrombin 5 U/ml (mean = 177 pmol/108platelets), measured using a radioimmunoassay for thromboxane B2. Formation of phosphatidic acid is an early step in stimulus‐response coupling in platelets. Our studies indicate that PAF is a weak stimulus for phosphatidic acid formation as well. To obtain further insights into its action, we examined the effect of PAF on platelets from three groups of patients with congenital secretion defects: patients with the storage pool deficiency, those with impaired thromboxane synthesis due to impaired liberation of AA from phospholipids, and those with impaired secretion despite normal granule stores and thromboxane production. The response to PAF was impaired in all patients, providing further evidence that PAF‐induced platelet activation is dependent on secreted ADP and thromboxane A2synthesis, and occurs by mechanisms common to a number of agonists. Overall, these studies indicate that PAF is a weak

ISSN:0361-8609    

DOI:10.1002/ajh.2830170207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractEighty‐three symptom‐free hemophiliacs were studied clinically, serologically, and by in vitro tests for cellular immunity in a geographical area in which AIDS has not yet been encountered despite the exclusive use of concentrates manufactured from American sources of plasma. Some patients showed the following abnormalites: lymphopenia (4%), decreased T‐helper/T‐suppressor (Th/Ts) cell ratios (49%), or both abnormalities (2%). Low Th/Ts were mostly due to absolute or, less frequently, relative increases in Ts cells. The prevalence rates for these abnormalites were the same in patients treated with factor VIII or factor IX concentrates. There was an association between the higher Ts and lower Th cells counts and the low Th/Ts ratios and greater annual consumption of factor VIII and factor IX concentrates. These results support the view that protein load might be an important pathogenetic factor in lymphocyte abnormalities in symptom‐free hem

ISSN:0361-8609    

DOI:10.1002/ajh.2830170208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractA method has been developed for separation of erythrocytes on the basis of size using counterflow centrifugation. Human red blood cells with an original mean corpuscular volume (MCV) of 89.2 ± 4.1 fl were isolated, free of plasma proteins and other cell contaminants, into seven fractions ranging in size from 77.0 ± 2.7 fl to 98.5 ± 4.8 fl. The ratio of the age‐related enzyme, erythrocyte glutamic oxaloacetic transferase (EGOT), to hemoglobin (Hb) increased progressively through the fractions, suggesting a correlation between erythrocyte volume and age. Reticulocytes, though present in all fractions, were selectively enriched in the larger subpopulations.To verify the biochemical evidence that erythrocytes decrease in volume with aging, in vivo cohort labeling of red blood cells with59Fe was performed in baboons. A similar relationship of EGOT to Hb was observed to that in the human subpopulations. The peak activity of59Fe/RBC appeared initially in the red blood cells with the highest MCV and progressed from the erythrocytes with the largest MCV to the erythrocytes with the smallest MCV over the next 10–12 weeks, confirming the hypothesis that red blood cells decrease in volume as they age. The technique of counterflow centrifugation appears to provide a simple, rapid, and reproducible method for the separation of erythrocytes on the basis o

ISSN:0361-8609    

DOI:10.1002/ajh.2830170209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractA pheresis procedure was devised to isolate young red cells by centrifugation using the Fenwal CS 3000 continuous flow cell separator. Young red cell enriched products were collected in a 2.5–3‐hour procedure. Large numbers of white cells and platelets were collected with the red cells, but cryopreservation and subsequent washing removed 99% of the contaminating cells. At the completion of all processing a product yielding 70% of the total hemoglobin content of a standard frozen/deglycerolized red cell unit was produced. Autologous radiochromium survival of young red cells, measured in 12 normal donors, showed an average 24‐hour recovery of 89.9% with a T50Cr of 40.8 days. In paired autologous studies (N = 4) there was a mean increase of 35% in the observed T50Cr of young red cells as compared to standard frozen red

ISSN:0361-8609    

DOI:10.1002/ajh.2830170210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractWe describe two female patients with systemic lupus erythematosus (SLE) who developed severe aplastic anemia. Although each patient had received multiple medications including diphenylhydantoin, the relationship of these drugs to the development of marrow aplasia was unclear. After administration of an oral androgen (oxymethalone) and corticosteroids, there was complete hematologic recovery. Both patients relapsed when oxymethalone was withdrawn, and both recovered when androgen therapy was reinstituted, with or without high‐dose prednisone. In both patients, there was complete reversal of pancytopenia despite the presence of initially severe marrow aplasia (less than 10% cellularity). However, in both cases, prolonged androgen therapy (2 months) was required before hematologic improvement occurred. Androgens are known to stimulate hematopoiesis in man, and they appear to influence immune function in a mouse model of SLE. Thus androgens may be particularly useful in the treatment of SLE‐associated aplastic ane

ISSN:0361-8609    

DOI:10.1002/ajh.2830170211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY