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Biomedical subjects

K Ucar

Publications and source records attributed to K Ucar.

8 recordsLinked to original sources
PubMed1992

Hypercoagulability and thrombosis.

This article has summarized known congenital and acquired alterations of hemostasis leading to thrombosis. Decreases in coagulation inhibitors, including antithrombin III, heparin cofactor II, and protein C and protein S, are of major importance in assessing patients with hypercoagulable states or patients with unexplained thrombosis. Newer assays for components of the fibrinolytic system, plasminogen, t-PA and t-PA inhibitor are also now readily available and are important for defining congenital or acquired fibrinolytic defects leading to hypercoagulability and thrombosis. By judicious use of these assays, combined with clinical evaluation, many patients with thrombosis will have an underlying etiologic blood protein defect defined. Delineating reasons for a thrombotic event is of obvious importance for planning long-term prophylactic therapy and for diagnosing and counseling afflicted family members. In this manner, newly found patients can be treated prophylactically before unalterable morbidity or mortality occurs.

Antithrombin III↗
PubMed1987

Proliferative characteristics of acute nonlymphocytic leukemia in vivo.

The proliferative characteristics of myeloid leukemias were defined in vivo following intravenous bromodeoxyuridine (BrdU). Fifteen patients received a 2-hour infusion of BrdU. A monoclonal anti-BrdU antibody was used to detect the in vivo incorporation of BrdU by S-phase cells. The percentage of S-phase cells obtained from the biopsies (mean 17.3%) was significantly higher (p = 0.00001) than the percentage determined from the aspirates (7.8%). It is concluded that the true estimate of S-phase cells can only be obtained from biopsies following in vivo labeling of cells synthesizing DNA. The persistence of BrdU-labeled cells in follow-up studies can be used to recognize 'residual leukemia', and the subsequent fate of these cells can be defined in vivo.

Acute Disease↗
PubMed1985

Utility and sensitivity of anti BrdU antibodies in assessing S-phase cells compared to autoradiography.

A rapid and convenient method for estimating S-phase cells in a population was developed which detects bromodeoxyuridine (BrdU) incorporation into DNA by means of monoclonal anti-BrdU antibodies. This immunofluorescence technique (RPMB technique) was compared to autoradiographic (ARG) detection of tritiated thymidine (3HTdr) grains incorporated into the DNA. Using incubation periods for BrdU and 3HTdr ranging from one minute to one hour and detecting their incorporation by ARG and RPMB techniques, it became apparent that the RPMB technique was far more sensitive than ARG in addition to being extremely easy to perform. Some possible utilities of the RPMB technique are discussed.

Antibodies, Monoclonal↗
PubMed1985

Differences between labeling index and DNA histograms in assessing S-phase cells from a homogeneous group of chronic phase CML patients.

The reliability of DNA histogram analysis in accurately estimating S-phase cells from human tumors was tested by comparing the results to those of simultaneously obtained tritiated thymidine labeling index (LI) studies. Patients with chronic myelocytic leukemia (CML) during chronic phase were selected for study because the Philadelphia chromosome (Ph) was the only cytogenetic abnormality in each case and, since it is a balanced translocation, the frequently encountered problem of aneuploidy in human neoplastic cells was avoided. Unfortunately, when 30 CML patients were studied simultaneously by DNA histogram analysis and LI studies, the correlation coefficient between the two results was only r = 0.611. A comparison of three different mathematical programs for DNA histogram analysis showed that none was completely satisfactory. We conclude that DNA histogram analysis does not provide the same data as autoradiographically processed labeling index studies even in patients with Ph-positive CML during the chronic phase when the situation is not complicated by additional aneuploidy.

Bone Marrow↗
PubMed1985

Double labeling and in vitro versus in vivo incorporation of bromodeoxyuridine in patients with acute nonlymphocytic leukemia.

A monoclonal antibody against bromodeoxyuridine (BrdUrd) was produced, and a rapid slide technique (RPMB technique) was developed for the estimation of S-phase cells in a population using this antibody. Bone marrow cells from patients with acute nonlymphocytic leukemia (ANLL) were studied by both the RPMB technique and tritiated thymidine (3HdThd) labeling index studies. The percentage of S-phase cells obtained by each method was compared in 50 samples, and the correlation coefficient was r = 0.89. A "double label" method is also described in which cells were simultaneously incubated with either BrdUrd and 3HdThd or BrdUrd and tritiated cytosine arabinoside (3HAra-C). The samples were first processed by the RPMB technique and then by autoradiography. Results showed only black grains overlying the nuclei of fluorescent cells in each group. An automated microphotometer was used to quantitate grains and fluorescence from each cell. This demonstrated an almost direct relationship between grains and fluorescence from BrdUrd + 3HdThd slides, whereas different patterns of relationship were noted from BrdU + 3HAra-C slides of leukemic patients. Their implications are discussed in the text. Finally, intravenous infusions of BrdUrd was given to five leukemic patients. S-phase cells were recognized distinctly within 5 min of starting the infusion. The percentage of S-phase cells was almost identical from in vivo and in vitro samples. Various possibilities of studying the biological behavior of acute leukemias and analyzing cell cycle characteristics are discussed.

Automation↗
PubMed1985

Double labeling of S-phase murine cells with bromodeoxyuridine and a second DNA-specific probe.

A rapid method has been developed which combines immunofluorescence and autoradiography and permits the double labeling of DNA. P388 murine leukemic cells were incubated with bromodeoxyuridine and tritiated thymidine simultaneously. After fixation, the sample was first processed with a monoclonal antibody to bromodeoxyuridine (RPMB I) so that any cell in S-phase was brightly fluorescent (RPMB technique). Next, tritiated thymidine grains were developed by autoradiography, and the result demonstrated fluorescence as well as black grains in each S-phase cell. P388 cells sensitive (P388S) and resistant (P388R) to 1-beta-D-arabinofuranosylcytosine (ara-C) were incubated with bromodeoxyuridine and [3H]ara-C simultaneously. Processing by autoradiography and RPMB techniques revealed that all S-phase cells in the P388S sample demonstrated vivid "double labeling," whereas P388R cells only revealed bright green fluorescence in S-phase cells, but no grains, confirming a lack of ara-C incorporation into the DNA by this line. Finally, a computerized digital analysis system attached to a microphotometer was used to quantitate fluorescence and grains per cell, and the data demonstrated that the number of [3H]ara-C grains in each P388S cell was inversely proportional to the degree of fluorescence in that cell, indicating that DNA synthesis was inhibited by ara-C. In conclusion, a simple, easy-to-use double-labeling method has been introduced which will be useful to a wide variety of researchers, because this technique together with the digital analysis system offers the possibility of measuring drug sensitivities in individual cells.

Animals↗