Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the number of megakaryocyte precursors (pro- and megakaryoblasts), an immunomorphometric study was performed on paraffin-embedded trephine biopsies of the bone marrow using a monoclonal antibody against platelet glycoprotein IIIa. Eighteen control specimens from patients with no evidence of any hematological disorder and a normal platelet count were selected and assessed together with the same number of specimens from patients with reactive thrombocytosis, polycythemia vera rubra (P. vera) or primary (essential) thrombocythemia (PTH). A strikingly proportionate increase in early megakaryocytes occurred in all patients enrolled in this study, compared with the controls. Moreover, there were no significant correlations between counts for precursors or total megakaryocytes per square millimeter of bone marrow with the corresponding values for platelets. This indicates that despite an orderly increase in immature forms in the bone marrow, the number of platelets circulating in the blood is influenced by other additional factors, such as the expanded platelet pool in the enlarged spleen. The non-disproportionate expansion of megakaryocyte precursors extends previous findings on progenitor cells of this lineage in vitro, particularly in PTH. Histological evaluation of the bone marrow of patients with P. vera and PTH indicated that megakaryopoiesis proceeded to the production of appropriate mature forms with no obvious excess of very small or blastic elements.
 ...
PMID:Megakaryocyte precursors (pro- and megakaryoblasts) in bone marrow tissue from patients with reactive thrombocytosis, polycythemia vera and primary (essential) thrombocythemia. An immunomorphometric study. 197 Jun 93

In 165 patients with chronic myeloproliferative disorders (CMPD) a morphometric and histochemical study was performed on trephine biopsies of the bone marrow to elucidate osseous remodeling by assessment of trabecular bone area (planimetry) and number of osteoclasts. Osteoclastic elements were identified by the tartrate-resistant acid phosphatase method. In addition to control specimens (n = 20) subtypes of CMPD included chronic myeloid leukemia (CML, n = 65), primary (essential) thrombocythemia (PTH, n = 25), polycythemia vera rubra (P. vera, n = 25) and agnogenic myeloid metaplasia (AMM, n = 50). AMM was discriminated into a so-called early hyperplastic stage without gross myelofibrosis (n = 19) and an overt or advanced stage showing fibro-osteosclerotic changes (n = 31). Total area of trabecular bone and counts for osteoclasts (uni- and multi-nucleated cells as well as a-nuclear cytoplasmic fragments) were not significantly increased in CML, PTH, P. vera and in the initial hypercellular stages of AMM. In contrast to these results, in advanced stages of AMM there was a significant increase in total bone area associated with a high count for all osteoclastic elements and apparently also an increased number of osteoblasts. It is speculated that the marked increase in osteoclastic-osteoblastic elements in late stages of AMM possibly reflects an imbalance of calcitriol (1.25-dihydroxyvitamin D 3) on skeletal homeostasis. This abnormal osseous remodeling may be mediated by the atypical megakaryocytic proliferation in this disorder, which is always a conspicuous feature of bone marrow biopsies.
 ...
PMID:Osteoclasts and bone remodeling in chronic myeloproliferative disorders. A histochemical and morphometric study on trephine biopsies in 165 patients. 278 Apr 31

A morphometric analysis of bone marrow biopsies was performed in 25 patients each with clinical diagnoses of primary (essential) thrombocythemia (PTH) and polycythemia vera rubra (P. vera) according to the rigid diagnostic criteria of the Polycythemia Vera Study Group to reveal significant differences in the histomorphologic features between these disorders. In comparison with control specimens of patients without any hematologic disease, megakaryocyte proliferation was most prominent in PTH, even exceeding that of P. vera with concomitant thrombocythemia (11 of 25 cases with a platelet count greater than 600 X 10(9)/L). Moreover, in P. vera there were wide ranges of megakaryocyte sizes, consisting of micro-megakaryocytes as well as giant forms with highly segmented nuclei (four nuclear lobes), which gave the cells a pleomorphic appearance. As compared with the normal bone marrow, the amount of neutrophilic granulopoiesis and erythropoiesis was not significantly increased in PTH, in contrast to P. vera. Similar results were obtainable regarding the density of reticulin (argyrophilic) fibers: a normal content was encountered in the control specimens and PTH, whereas P. vera displayed a minimal-to-slight increase. Finally, the bone marrow of P. vera was totally devoid of stainable iron while hemosiderin deposits were detected in about two-thirds of the patients without hematologic disorders and in PTH. The characteristic differences revealed by this morphometric study may lead to an improvement of the controversial histologic diagnosis in these disorders.
 ...
PMID:Primary (essential) thrombocythemia versus polycythemia vera rubra. A histomorphometric analysis of bone marrow features in trephine biopsies. 320 62

Morphometry was employed on different entities of chronic myeloproliferative diseases (CMPD) and reactive lesions in addition to normal control specimens. The entities studied included: (1) inflammatory reactions of the bone marrow (so-called myelitis in chronic rheumatoid arthritis), (2) chronic granulocytic leukemia (CGL), (3) agnogenic myeloid metaplasia in an early hypercellular stage (so-called chronic megakaryocytic-granulocytic myelosis, CMGM), (4) agnogenic myeloid metaplasia in an advanced fibrosclerotic stage or osteomyelofibrosis/sclerosis (MF/OMS), (5) polycythemia vera (P. vera), (6) reactive thrombocytosis (TH, as a sequel of miscellaneous conditions) and (7) primary (idiopathic, essential) thrombocythemia (PTH). Evaluation was done on plastic-embedded semithin sections with a constant thickness of 3 micron in approximately 20 cases of each group of CMPD. The following parameters were determined: (1) density distributions of the megakaryocyte and non-megakaryocyte compartments, (2) arrangement of megakaryopoiesis in the bone marrow space (i.e., inhomogeneity or clustering) and (3) the fine structure of megakaryocytes in PTH, with a quantitative analysis of the nuclear morphology by circular deviation and contour factors. The megakaryocyte morphology was closely related to a facultative or obligatory increase of the platelet count in these various entities of CMPD and was separable into two major categories: (1) controls, CGL and myelitis versus (2) CMGM, MF/OMS, P. vera, TH and PTH. These two categories were distinguishable by the prominence of megakaryopoiesis in the bone marrow as well as the elevated platelet counts in the periphery. Moreover, in comparison with CMGM and MF/OMS, PTH was characterized by an apparently normal maturation and a conspicuous polyploidization of megakaryocytes according to the nuclear morphology, which was similar to that of P. vera. Our results suggest that PTH presents a monolinear growth of the megakaryopoiesis in the same way as CGL exhibits a monolinear proliferation of the neutrophilic granulopoiesis. This is in contrast to the mixed cellularity of both the megakaryocyte and granulocyte lineage in CMGM and MF/OMS.
 ...
PMID:Megakaryopoiesis in chronic myeloproliferative diseases. A morphometric evaluation with special emphasis on primary thrombocythemia. 659 64

Morphometric analysis of sections of biopsy specimens from patients with chronic myeloproliferative disorders (CMPD) can complement the individual histological diagnosis and help to distinguish the four groups of CMPD. A total of 130 diagnostic biopsies from 29 cases of chronic myelocytic leukemia (CML.CT), 26 cases of (CML.MI), 28 of essential thrombocythemia (PTH), 26 cases of chronic megakaryocytic granulocytic myelosis (CMGM), and 21 of polycythemia vera (P. vera), and 30 from healthy control persons were evaluated morphometrically in sections of undecalcified plastic-embedded core biopsies. Clear distinctions were revealed in size of megakaryocytes, nuclear lobulation, clustering, and the nuclear size and shape of megakaryocytes. Nuclear size and cellular size were significantly less in CML (range of means of cellular size: 220-360 microns2) than in the other three Ph1-negative groups (range of means: 480-750 microns2). Nuclear lobulation was more distinct in PTH than in P. vera, and especially in CMGM. Clustering of megakaryocytes was more than twice as frequent in CMGM (8.0-10.5%) as in any of the other three groups (0.1-7.0%). Naked nuclei were more numerous in all groups of CMPD. The main topic of the study is the different size of megakaryocytes in the four main groups of CMPE, allowing a distinction between small-megakaryocytic Ph1-positive CML and large-megakaryocytic Ph1-negative forms of CMPD.
 ...
PMID:[Morphometry of megakaryocytes for supporting the histologic diagnosis of chronic myeloproliferative diseases]. 788 12

In order to determine the dynamics of hematopoietic cell turnover, proliferative activity and incidence of apoptosis (programmed cell death) were evaluated in bone marrow trephine biopsies. Selection of patients (20 in each group) included in addition to a control group, idiopathic thrombocytopenia (ITP), reactive thrombocytosis (TH), secondary polycythemia-smokers' polyglobuly (PG), primary (essential-hemorrhagic) thrombocythemia (PTH), polycythemia vera (PV), and finally acute myeloid leukemia (AML). Apoptosis was demonstrated by the in situ end-labeling technique (ISEL) and proliferative activity by applying the monoclonal antibody PC10 raised against proliferating cell nuclear antigen (PCNA). To assess dynamic features of hematopoiesis, an index was calculated consisting of the ratio between PCNA-positive nuclei and the apoptotic cell fraction. This factor was termed the hematopoietic turnover index (HTI). Morphometric analysis revealed that the HTI was significantly increased in AML and PV. According to cell culture studies both disorders are characterized by either a prevalent proliferation of the myeloid or erythroid cell mass. On the other hand, PG, PTH, and TH showed no relevant enhancement of this index in comparison to the control specimen. In vitro experiment results are in keeping with the finding that PG and PTH are not associated with a significant expansion of the erythroid lineage (CFU-E). Similar to ITP and TH, in PTH megakaryocyte proliferation (CFU-MEG) is the predominant feature of cell turnover. Differences between PTH and TH are in line with the reduced in vitro formation of CFU-MEG in the latter disorder. In conclusion, our in situ study on turnover rates of the bone marrow in various neoplastic and reactive lesions extends previous experimental data on hematopoietic cell kinetics.
 ...
PMID:Hematopoietic turnover index in reactive and neoplastic bone marrow lesions: quantification by apoptosis and PCNA labeling. 932 81

In this paper we describe a patient with polycythemia vera (PV), who presented with hypercalcemia due to a parathyroid adenoma. In November 1999, the patient was admitted to our hospital with meteorism and constipation. Her physical examination revealed plethora and hepatosplenomegaly. Laboratory data revealed hyperparathyroidism in addition to PV: Rbc 8 x 10(6)/mm3, Hct 63.7%, serum calcium 13.4 mg/dl, serum phosphorus 1.2 mg/dl, albumin 4.25 mg/dl, and alkaline phophatase activity 433 U/l. Intact Parathyroid Hormone level (iPTH) was 376 pg/ml (n.v.12-72 pg/ml). Twenty-four hour urinary calcium excretion was higher than normal (900 mg). A parathyroid adenoma was detected with Tc-99m sesta-MIBI scanning under the left lobe of the thyroid gland and an ultrasonographic examination of the neck also supported the diagnosis. The patient was recommended for surgery. The histopathological examination confirmed the diagnosis. Postoperatively, iPTH dropped to 53.4 pg/ml at the 15 th minute and to 33.5 pg/ml at the first hour. The calcium level was 7.5 mg/dl one hour after the operation. Five days later, Hct was 40.8%. This case represents a rare association between PV and primary hyperparathyroidism, and may provide evidence for a causal link between PTH and polycythemia vera in our patient. In conclusion, this case indicates that the differential diagnosis of hypercalcemia and polycythemia vera should also include the possibility of a parathyroid tumor in addition to malignancy.
 ...
PMID:An unusual cause of hypercalcemia in polycythemia vera: parathyroid adenoma. 1210 88