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Biomedical subjects

E Kelemen

Publications and source records attributed to E Kelemen.

At least 55 records · Page 3Linked to original sources
PubMed1987

Surgical treatment of renovascular hypertension.

Unilateral stenosis of the renal artery was verified by angiography in 34 patients with hypertension. The cause-effect relationship between elevated blood pressure and stenosis of the renal artery was proved by detailed renin studies (basic plasma renin activity, plasma renin activity following orthostatic and diuretic stimulation, renal vein renin activity). Surgical treatment was applied in 39 cases: they were aortorenal bypass in 9, autotransplantation in 7, patch graft in 2, denervation in 2, decompression in 3 and nephrectomy in 16 cases. Six months following the operation, 68.4% of the patients were normotensive without drugs and 18.4% of them with a reduced dose of drugs. To achieve normotension preoperative treatment had to be continued only in 13.2% of the patients. Two to four years postoperatively, 29 patients were subjected to control examinations and in 23 cases also to angiography. Restenosis was observed in 4 patients (17.4%). As a result of surgical treatment, the increased response to hyperreninaemia and to various stimuli decreased. Based on the control examinations, 58.7% of the patients could be considered to be cured.

Adolescent↗
PubMed1986

Separate ontogeny of two macrophage-like accessory cell populations in the human fetus.

Human macrophage-like accessory cells were analyzed as they emerge in the absence of extrinsic antigens during fetal development. Monoclonal antibodies to monocytes/macrophages were used in combination with antibodies to HLA class II molecules. In the yolk sac and mesenchyme sampled at wk 4 to 6 of fertilization age, cells with dendritic morphology formed two populations distinguishable by phenotypic criteria: type i (majority) carried both macrophage-associated (RFD7+) and monocyte-associated markers (UCHM1+) but no detectable HLA-DR antigen, and type ii (minority) constitutively expressed class II (HLA-DR and -DP) but no RFD7 and UCHM1. The emergence of this heterogeneity preceded the formation of both thymus and bone marrow. During additional development, type i and type ii cells seeded to different microenvironments and underwent some additional phenotypic changes. Cells of type i, the RFD7+ population with high lysosomal (acid phosphatase) activity, were seen in the thymic cortex, marginal zone of lymph nodes, splenic red pulp, and in the midst of erythropoietic activity within the bone marrow. These cells were UCHM1- and class II-. Cells of type ii formed the population of HLA-DR+, RFD7- interdigitating cells, early inhabitants of T cell areas in the developing thymic medulla, lymph nodes, spleen, and tonsil. The Type ii cells that had already settled in their nichès expressed not only HLA-DR and -DP but also HLA-DQ, and another class II antigen identified by the antibody RFD1, which shows the restricted tissue distribution of HLA-DQ, but is governed by genes that are outside of and telomeric to the HLA-DQ region (or HLA-DR). Finally, subpopulations of macrophages (RFD7+, acid phosphatase-positive) in the fetal gastrointestinal and hepatic systems were HLA-DR+; the latter appear to include precursors of Kupffer cells in the developing liver.

Acid Phosphatase↗
PubMed1986

Permanent large granular lymphocytosis in the blood of splenectomized individuals without concomitant increase of in vitro natural killer cell cytotoxicity.

Increased numbers of circulating lymphocytes and large granular lymphocytes (LGL) were observed in 115 individuals splenectomized for haematological disease (74 cases) or for trauma (41 cases). LGL lymphocytosis was present in 78.4% of haematologically indicated and in 85.4% of traumatic splenectomies. A 70.5% of these values was above the 97.5 percentile upper tolerance limit of healthy controls (200 cases). In addition, 175 haematological controls were investigated. Forty per cent or more of circulating lymphocytes exhibited LGL morphology in nearly half of repeatedly investigated splenectomized persons. The increase in LGL is not attributable to lymphocytosis. It becomes apparent, and persists after the first postoperative week, irrespective of the cause of surgery. In spite of the two-fold increase in LGL concentration in the blood, in vitro natural killer (NK) and antibody dependent cellular cytotoxic (ADCC) activities did not increase in the investigated 48 (NK) and 31 (ADCC) splenectomized persons, as compared with the appropriate healthy or haematological controls.

Adolescent↗
PubMed1985

Bone marrow transplantation in accelerated chronic granulocytic leukaemia using dibromomannitol-preconditioning instead of total-body irradiation.

In a preliminary study on five patients with accelerated CGL, transplantation of allogeneic matched bone marrow was shown to be feasible without whole-body irradiation. Animal experiments and studies with cells cultured in vitro suggest that the cytocastic drug used to kill leukaemic clones (Myelobromol-Chinoin) does not injure haemopoietic stroma. The administration of this protocol is cheap and easy. Our preconditioning does not, in itself, eradicate the malignant CGL clone immediately: 15-20% of marrow mitoses were Ph1+ one month after transplantation. For this reason, additional cytostatic therapy was given in the course of the 3rd to 6th post-transplant months. No Ph1+ cells were observed from the fourth post-transplant month onwards. Very few severe acute complications were seen and two out of three matched transplanted patients are disease-free 27 + and 13 + months later. On the basis of the developing normal spleen architecture and the changing pattern of circulating NAP score values, particularly the months-long persistence of distinctly low scores, and then the delayed emergence of normal levels, we put forward a hypothesis, emphasizing the role of environmental factors, including the formation of a normal haemopoietic stroma in the successfully transplanted CGL patient.

Adolescent↗
PubMed1985

Human B cell development. II. Subpopulations in the human fetus.

In man, during fetal development the B cell populations show distinct phenotypes at different tissue sites. The pre-B and B lymphocytes of the fetal liver and bone marrow express IgM and B cell markers, B1 (CD20) and BA-1 (CD24). These "early" cells are negative with a number of other reagents, anti-IgD, RFB4 (CD22), RFB6 (CD21), and RFA-2, which on the other hand recognize peripheral B cells. These peripheral B lymphocytes in the developing fetus are heterogeneous. The diffusely distributed B cells in the earliest lymph node samples, 16 to 17 wk of gestational age, and from 16 to 21 wk in the spleen, are strongly IgM+ (IgD+,RFB4+,RFB6+, and RFA-2+) but lack T cell-associated markers such as T1 (CD5, p 67,000 dalton equivalent of murine Ly-1) and Tü-33. In fetal lymph nodes, primary nodules develop around the follicular dendritic (FD) cells from 17 wk onward, and contain a virtually pure population of B cells; B1+,BA1+,RFB4+,RFB6+,RFA-2+, which simultaneously express IgM,IgD together with T1 (CD5), a T cell-associated antigen. A sizeable subpopulation of these IgM+,T1+ cells are also positive for Tü-33, another T cell-associated marker. In the spleen, the B cells of the IgM+,IgD+,T1+ type appear in smaller numbers and only relatively late around wk 22. These cells are diffusely distributed at first, and start accumulating around the small FD cell clusters as soon as these emerge about the 23rd gestational wk. At that time, the IgM+,T1+B cells can also be washed out from the peritoneal and pleural cavities. The T1+,IgM+B cells may represent the normal equivalent cells of B chronic lymphoid leukemia and centrocytic lymphoma, and appear to be the counterpart of Ly-1+,IgM+B cells in the mouse.

Adult↗
PubMed1984

Developmental age estimated by bone-length measurement in human fetuses.

The lengths of 491 long bones of the extremities derived from 193 freshly delivered human fetuses of 7 to 22 weeks fertilization age were measured. Fetuses delivered after spontaneous abortion, twin pregnancy, or known maternal disease were excluded. The correlation between fetal age (measured by crown-rump length) and bone length was linear. The term "developmental age" was used for bone length-derived age values. Developmental age can be determined from the length of even a single bone, i.e., when mechanical injury of the delivered fetus inhibits crown-rump length measurement. The results could aid researchers dealing with human embryology, clinicians performing fetal tissue transplantation, and could be applied in forensic medicine as well.

Anthropometry↗
PubMed1984

The effect of external sodium on ouabain-insensitive K influx in fresh human red blood cells.

The rate of 42K influx was investigated at various external sodium and ouabain concentrations in human red blood cells. In agreement with earlier reports, in red blood cells not treated with ouabain, Na did not affect K influx when [K]0 was 5.0 mM while it reduced the influx at [K]0 = 0.15 mM. However, Na stimulated 42K influx at both 5.0 mM and 0.15 mM in cells treated with ouabain (1 X 10(-5) M). When external Na concentration was raised from 0 to 72 mM the rate of 42K influx increased at [K]0 = 0.15 mM and at ouabain = 1 X 10(-5) M. The effect of external Na at different ouabain concentrations showed that K influx was inhibited by Na without or with ouabain in less than 5 X 10(-6) M while an increased K influx could be observed with higher ouabain concentrations in the incubation media. The results suggest that in the case of the complete inhibition of ouabain-sensitive K influx the electrochemical gradient of the Na ions may serve as a driving force for the inward movement of potassium.

Biological Transport, Active↗