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Biomedical subjects

M A Popovsky

Publications and source records attributed to M A Popovsky.

At least 91 records · Page 5Linked to original sources
PubMed1985

Degradation of factor VIII coagulant antigen by proteolytic enzymes.

The factors responsible for the lability of factor VIII coagulant activity (VIII:C) and factor VIII coagulant antigen (VIII:CAg) are poorly understood. In this study the VIII:C and VIII:CAg are studied after incubation with plasmin, trypsin or alpha-chymotrypsin. Both isolated human VIII:CAg and VIII:CAg associated with factor VIII-related antigen (VIII R:Ag) are evaluated. The antigenic sites of the VIII:CAg are somewhat more stable to the action of these enzymes than the functional activity, although both follow a generally parallel degradation. A biphasic decay curve is seen in the initial time points. No stabilization of the functional or antigenic reactivity is observed in the presence of the VIII R:Ag. Lower concentrations of each enzyme cause an initial rise in the factor VIII:C in the presence of VIII R:Ag, but not in the isolated VIII:CAg. Higher concentrations of alpha-chymotrypsin cause activation of VIII:C and a slight decrease in the VIII:CAg values in both preparations. These enzymes may play a modulating role in the coagulation cascade through the activation and degradation of VIII:C and VIII:CAg.

Antigen-Antibody Reactions↗
PubMed1983

Transfusion-related acute lung injury associated with passive transfer of antileukocyte antibodies.

Acute lung injury (ALI) is an infrequently recognized complication of transfusion therapy. Although the role of passive transfer of leukoagglutinating antibodies has been acknowledged, there is little documentation of the relationship of these antibodies in transfused blood to the human leukocyte antigen (HLA) phenotype of the recipient. Recently, we observed 5 cases of transfusion-related ALI, and in all cases leukoagglutinating and lymphocytotoxic antibodies were found in serums of the transfused blood products. In 3 cases, the antibodies corresponded to the HLA antigens of the recipient. Multiparous blood donors whose plasma contains these antibodies represent a potential transfusion hazard. It is recommended that blood component usage from donors implicated in these reactions be restricted to frozen or washed red blood cells. The incidence of leukoagglutinin-associated ALI may be more frequent than previously appreciated. Current concepts of the mechanism of microvascular pulmonary injury are discussed in relation to these cases.

Acute Disease↗
PubMed1980

Parosteal osteogenic sarcoma. Ultrastructural observations in three cases.

Ultrastructural study of three parosteal osteogenic sarcomas showed this type of tumor to contain numerous myofibroblasts. These cells were admixed with occasional cells resembling osteoblasts and fibroblasts. Cartilaginous areas showed the typical arrangement of cartilage cells embedded in a dense collagen matrix. Ultrastructural examination of a recurrent lesion revealed the presence of numerous undifferentiated cells as well as the types of cells just described. In addition, desmosomes were evident between the more undifferentiated cells. The ultrastructural study of these tumors shows that parosteal osteogenic sarcomas are ultrastructurally a distinctive type of osteogenic sarcoma.

Adolescent↗
PubMed1979

Thrombocytosis, coronary thrombosis and acute myocardial infarction.

Clinical and morphologic findings are described in a 22 year old man with prolonged thromboyctosis, and coronary and splenic arterial thrombi causing myocardial and splenic infarcts. The absence of preexistent extensive coronary atherosclerosis, the presence of thrombus in more than one epicardial artery and in multiple intramural coronary arteries, the presence of arterial thrombosis in a noncoronary artery (splenic) and the absence of another apparent cause of the arterial thromboses are evidences that the intraarterial clotting in this patient was related to the severe thrombocytosis. A reveiw of the reported cases of vascular occlusion associated with thrombocytosis indicates that thrombi have infrequently been confirmed as the mechanism of the vascular occlusion. Although the frequency of vascular thrombi in patients with thrombocytosis has not been established, it is clear that vascular thrombosis can be a consequence of thrombocytosis and, as demonstrated by the present patient, that the coronary artery may be the site of the vascular occlusion, a heretofore unconfirmed event.

Adult↗
PubMed1979

Meyenburg complexes of the liver and bile cysts as a consequence of hepatic ischemia.

Meyenburg complexes and simple bile cysts are described in a patient having polyarteritis nodosa with involvement of the intrahepatic arterial tree. Similar lesions are found in the liver of monkeys subjected to experimental occlusion of the peripheral hepatic arterial tree. It is proposed that a pathogenetic mechanism conducive to the formation of Meyenburg complexes may be hepatic ischemia.

Animals↗
PubMed1979

Bile duct cysts secondary to liver infarcts: report of a case and experimental production by small vessel hepatic artery occlusion.

Hepatic bile duct cysts were demonstrated on an abdominal CT scan and confirmed at autopsy in a patient with polyarteritis nodosa. The cysts developed in close proximity to hepatic artery aneurysms and occlusions visualized at hepatic arteriography and confirmed postmortem. The development of similar bile duct cysts following hepatic artery occlusion was demonstrated in 13 Rhesus monkeys.

Aneurysm↗
PubMed1979

Acute occlusion of the posterior spinal vein. Experimental study in monkeys.

The posterior spinal vein was occluded with silicone in seven rhesus monkeys, and locally resected in one. There were no neurological findings associated with acute venous obstruction of the cord. Follow-up arteriography revealed diversion of venous outflow into the anterior spinal venous system. Histology revealed gliosis associated with demyelinization confined to the posterior columns.

Angiography↗
PubMedDate not supplied

Diagnostic and pathogenetic considerations in transfusion-related acute lung injury.

Transfusion-related acute lung injury (TRALI) is an infrequent but life-threatening complication of hemotherapy. The findings in 36 cases are described. The typical clinical presentation includes acute respiratory distress characterized by hypoxemia and fulminant pulmonary edema. The onset is usually within 4 hours of transfusion and is accompanied by hypotension. In most patients (81%), recovery is rapid and complete. In 89 percent of cases, granulocyte or lymphocytotoxic antibodies are found in the serum of the implicated blood product which contained plasma. HLA-specific antibodies were identified in donor serums in 65 percent of cases evaluated. The passive transfer of these antibodies may promote complement activation and subsequent pulmonary injury. TRALI is an important cause of transfusion-associated morbidity and is probably often misdiagnosed. Blood banks need to identify donors whose plasma causes these reactions in order to prevent their recurrence.

Adult↗
PubMedDate not supplied

Prevalence of Babesia antibody in a selected blood donor population.

Human babesiosis, a parasitic disease transmitted by the tick, Ixodes dammini, was confined previously to limited areas of the northeastern United States. It is a rare but potentially life-threatening complication of transfusion. Red cells and platelets prepared from asymptomatic donors have been implicated in transfusion-transmitted cases. More cases of babesiosis are being reported as the range of the vector expands in the United States. Blood donors from an endemic area were tested for antibody to Babesia microti during the summer. Only 3.7 percent of the 779 donors were seropositive, compared with 4.7 percent (p greater than 0.05) of donors from a nonendemic area. An epidemiologic survey of seropositive and matched seronegative controls demonstrated no significant differences that would assist in screening donors.

Adult↗
PubMedDate not supplied

Autologous versus homologous donors. Evaluation of markers for infectious disease.

Autologous blood donations may provide a new source of blood when components not used by the donors are deemed suitable for homologous use. However, the risk of transfusion-transmitted diseases form such donors has not been evaluated. We compared the prevalence of infectious markers and rate of abnormal responses to a confidential donor ballot in autologous donors from two blood collection programs, one blood center and one hospital-based, to corresponding homologous blood programs. The incidence of abnormal test results in autologous donors for HIV antibodies (either Western blot confirmed or repeatedly reactive, unconfirmed), HBsAg, ALT, and anti-HBc were not statistically different from homologous rates. The incidence of STS abnormalities in autologous donors was statistically significant, although all positive results were biologic false positives. The rate of abnormal responses to the confidential ballot was statistically significant only in autologous donors whose collections were already determined to be unsuitable for homologous use due to medical history problems. Although the data do not address infectious complications in transfusion recipients, this study offers no evidence that autologous blood components are less safe than their homologous equivalents.

Blood Donors↗
PubMedDate not supplied

The safety of preoperative autologous blood donation in the nonhospital setting.

The increasing use of preoperative autologous donation (PAD) of blood has led to more frequent donation in settings outside of hospitals, despite concerns that persons making PADs may face increased risks of postdonation reaction. Analysis was conducted of 5660 PADs made at 25 different blood centers, to determine the risks of PAD in nonhospital settings and to search for predictors of severe reactions. Sixteen percent (886) of the donations studied were by persons who did not meet all usual homologous donor criteria. The most common variances were for cardiovascular disease, including the use of cardiac drugs (416 donors, 41% of those not meeting criteria), history of angina (204, 23%), and history of myocardial infarction (192, 22%). Donation by persons not meeting routine criteria was followed by a higher reaction rate than that by donors without any variance (4.3 vs. 2.7%; p less than 0.0001). An increased likelihood of reaction was associated with donor age less than 17 years, female gender, weight less than 110 pounds, and a history of reaction. Four reactions were graded as severe (transient ischemic attack, 1; angina, 3), and all occurred in donors not meeting all criteria (0.4% of 886 donations). A review of these donors' histories failed to identify distinguishing features from which their severe reactions could have been predicted. This study documents the infrequency of severe reactions after PADs by persons referred to a blood center for donation, even those not meeting routine homologous donor criteria, and quantitates the risk to these donors of a severe reaction.

Aged↗