Biomedical subjects

R L Berkow

Publications and source records attributed to R L Berkow.

42 records · Page 3Linked to original sources

PubMed1984

Isolation of human megakaryocytes by density centrifugation and counterflow centrigual elutriation.

Density centrifugation and counterflow centrifugal elutriation were utilized to prepare enriched fractions of megakaryocytes from human bone marrow aspirates. This separation method enriched megakaryocytes in initial marrow aspirates by 116- to 463-fold. Approximately 63% of megakaryocytes were recovered from the initial samples, composing 18.7% of the nucleated cells in the final preparations. Mean megakaryocyte diameters of 51.6 micron and 33.8 micron were obtained from fixed and unfixed cellular specimens, respectively. Smaller platelet glycoprotein-positive mononuclear cells with a mean diameter of 20.5 micron were found in the highest concentrations in this final fraction. These cells presumably represent immature megakaryocytic forms. Counterflow centrifugal elutriation provides a means of isolating enriched populations of marrow megakaryocytes. This accessibility to viable populations of human megakaryocytes will allow additional investigation of the terminal events of megakaryocyte development.

Bone Marrow↗

PubMed1983

Retinoblastoma in Navajo Indian children.

Retinoblastoma occurs with an observed incidence of one in 18,000 live births, and 35% to 45% of cases are transmitted genetically in a dominant fashion. A retrospective analysis of Navajo Indian children during the past 15 years disclosed an incidence 21/2 to three times the expected. This observation raises the possibility that silent expression of the gene for retinoblastoma occurs more frequently among the Navajo population compared with the population at large.

Child↗

PubMed1983

Invasive aspergillosis of paranasal tissues in children with malignancies.

Paranasal aspergillosis was encountered in five children with relapsed malignancies. All had received broad-spectrum antibiotics within two weeks of development of aspergillosis, and all had absolute granulocyte counts less than 200/mm3 for at least three weeks. None had received prior antifungal therapy. There was an average delay of eight days before the correct diagnosis was established by either biopsy or culture. These data emphasize the need to obtain surveillance cultures of the upper respiratory tract passages in severely neutropenic patients receiving prolonged antibiotic therapy, and raise a question concerning prophylactic use of antifungal therapy in this group.

Adolescent↗

PubMed1983

Papillary serous carcinoma of the retroperitoneum.

We describe a retroperitoneal neoplasm in an 11-year-old girl which had a light microscopic appearance identical to that of papillary serous carcinoma of the ovary. There was no evidence of ovarian involvement. Immunohistochemical staining for amylase was positive within the cytoplasm of tumor cells. Since amylase is a marker for serous ovarian tumors, this finding supports the belief that "ovarian-type" neoplasms that occur at ectopic locations are essentially identical to their ovarian counterparts. We believe they originate from metaplasia of mesothelium. Our findings support the concept that these tumors should exhibit a biologic behavior and therapeutic response which are similar to those of an ovarian tumor of the same grade and comparable stage. The demonstration of intracytoplasmic amylase also may prove useful in differentiating peritoneal serous tumors from non-metaplastic mesothelial proliferations. We are unaware of a prior report of an extra-ovarian serous carcinoma in a child.

Amylases↗

PubMed1983

The comparative responses of human polymorphonuclear leukocytes obtained by counterflow centrifugal elutriation and Ficoll-Hypaque density centrifugation. I. Resting volume, stimulus-induced superoxide production, and primary and specific granule release.

Standard isolation techniques for the human polymorphonuclear leukocyte (PMN) involve sequential exposure of cells to the nonphysiologic environments of dextran, Ficoll-Hypaque (FH) gradient centrifugation, and hypotonic conditions. It has been suggested that these may be harmful to the recovered PMN. Counterflow centrifugal elutriation (CCE) allows separation of human PMNs while the cells are continuously bathed in a physiologic and isotonic buffer. To investigate whether preparative technique may alter PMN activation, we compared PMNs obtained by these two methods for stimulus-induced superoxide production and release of primary and specific granule contents. Resting PMN volume was also evaluated. We observed that PMNs obtained using the CCE method were larger and released significantly more superoxide and specific granule contents than PMNs obtained by the standard FH technique. The possible origins for these differences are discussed.

Adult↗

PubMed1979

Acute nonlymphocytic leukemia: expression in cells restricted to granulocytic and monocytic differentiation.

Two patients with acute nonlymphocytic leukemia who were heterozygous for the X-chromosome-linked enzyme glucose-6-phosphate dehydrogenase were studied to determine the number and type of cells in which the disease arises. Both type A and B isoenzymes were found in normal tissues, but the myeloblasts showed only one enzyme type, indicating that at the time of study, the disease had a clonal origin. The observation in one patient that erythroid cells did not arise from this clone contrasts with conclusions reached in patients previously studied with chromosomal markers. The results suggest that in this patient, the leukemic clone suppressed expression of normal granulopoiesis but did not inhibit erythroid differentiation from normal progenitors. They suggest also that the disease is heterogeneous. In some patients, the disease is expressed in cells with differentiation restricted to the granulocyte-macrophage pathway; in others, it involves stem cells that also differentiate into erythrocytes. This heterogeneity may reflect differences in causation and could have prognostic importance.

Acute Disease↗