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Biomedical subjects

J Jansen

Publications and source records attributed to J Jansen.

At least 253 records · Page 14Linked to original sources

Morphogenesis and morphology of the brain stem nuclei of Cetacea. II. The nuclei of the accessory, vagal and glossopharyngeal nerves in baleen whales.

The development and final structure of the IXth, Xth and XIth cranial nerve nuclei are studied in ironhematoxylin -, thionin - and protargol -stained serial sections of about 50 baleen whale fetuses (blue whale, Balaenoptera musculus, and fin whale, Balaenoptera physalus ) and one adult fin whale. The nucleus ambiguus is composed of three subdivisions, oral, intermediate and caudal, the last mentioned being contiguous caudally with the dorsal motor Xth nucleus. The oral division develops as three parallel cell columns which merge into a well circumscribed solitary structure with a rostrally expanded "head". It is composed of medium-sized multipolar neurons in a myelin-poor neuropil. In the fin whale a minor group of larger cells is found medial to the "head". In both species a peculiar small-celled nucleus rich in capillaries is found ventral to the "head". The intermediate division initially contains a lateral cell column and a medial region of scattered cells. The lateral column persists throughout life, while the medial field develops into three columns only one of which remains distinct in mature individuals. The cells are larger than in the oral division with the largest cells in the medial column. The two columns are surrounded by a field of scattered neurons which continues without a sharp border into the caudal division which is composed of scattered cells throughout. In its rostral half the cells are of the same multipolar type as in the intermediate division while caudally they appear flattened in the horizontal plane. The dorsal motor Xth nucleus develops as three longitudinal columns. In the fetal brain these are cytologically distinct due to different proportions of small, medium-sized and larger multipolar neurons. The spindle-shaped ventromedial column extends the entire length of the nucleus. It is composed mostly of small to medium-sized cells which caudal to the obex are elongated parallel with the neuroaxis . The dorsolateral and ventrolateral columns are restricted to the middle 1/3 of the nucleus, except in the blue whale where the former extends somewhat more rostrally. They are both characterized by the presence of large multipolar cells, the largest of which are found in the ventrolateral column. In adult specimens the cells are more equally sized and the columnar organization less distinct. The nucleus of the tractus solitarius is of about the same length as the two above mentioned nuclei. Except at the very early stages, the nucleus is ill-defined.(ABSTRACT TRUNCATED AT 400 WORDS)

Accessory Nerve↗

Comparison of complement-dependent cytotoxicity and indirect immunofluorescence for enumeration of T-cell subpopulations in human peripheral blood.

The monitoring of T-lymphocyte subsets of recipients of organ grafts enables studies on immune reconstitution (after bone-marrow transplantation) and may predict graft rejection (after kidney transplantation). Quantitation of human peripheral T-lymphocyte subsets from healthy volunteers and from recipients of a bone-marrow graft by a complement dependent cytotoxicity (CDC) assay, based on the use of propidium iodide, and by an indirect immunofluorescence (IIF) technique has been compared using the monoclonal antibodies OKT3, OKT4 and OKT8. Except for OKT3 in healthy individuals--for which no significant difference was found between CDC and IIF--CDC detected significantly more cells of each subset than IIF. Furthermore, the CDC results indicated the presence of low numbers of OKT4+8+ cells in the peripheral blood of healthy individuals and--with higher numbers--following marrow transplantation. Results of depletion experiments, obtained by fluorescence activated cell sorting (FACS) for either OKT4 or OKT8, supported this conclusion. OKT4/OKT8 ratios were calculated from enumerations by the CDC assay and by the IIF assay and found to be linearly related, both in healthy persons and in marrow-graft recipients. Thus, the CDC assay is a reliable method for monitoring T-cell subsets, allowing detection of lymphocytes carrying low densities of membrane determinants.

Antibodies, Monoclonal↗

[Prevention of Strongylidae infections in the horse].

Proceeding on the epidemiology of Strongylidae infection in horses, the effects of combined anthelmintic treatment and moving to non-contaminated pasture in July were studied during 1981 and 1982. This strategy for control was found to be effective as was shown by faecal examination, pasture larval counts and post-mortem worm counts. No significant contamination or worm infection developed in the group of treated ponies moved to celan pasture after July 1. On the permanently grazed pasture the same pattern of infection developed as on the pasture where up to July 1 ponies and subsequently sheep had grazed.

Animal Feed↗

[Observations on the effect of some measures for preventing gastrointestinal helminth infections in sheep].

Prophylactic anthelmintic treatment of ewes about parturition has only a negligible effects on the most important species of helminths when the ewes and their lambs are not grazed on clean pasture. Haemonchus contortus infections were completely prevented in some cases but usually severe infections occurred. As the build-up of these heavy infections in lambs was slightly delayed in comparison with that in the lambs of untreated ewes, treatment about parturition should still be regarded as useful. Treatment of lambs at the time of weaning combined with moving the animals to a clean pasture is a useful though not entirely effective preventive measure. Particularly when the lambs continue to stay on the farm, they have to be moved to clean pasture and/or treated with anthelmintics more frequently.

Animals↗

Characterization of B-cell non-Hodgkin's lymphomas. A study using a panel of monoclonal and heterologous antibodies.

A panel of monoclonal and heterologous antibodies directed against clearly defined antigens was used to characterize the cellular composition of 57 non-Hodgkin's lymphomas, classified according to the Kiel classification, with a slight modification. The antisera were directed against T-lymphocytes and their subsets (Leu1, Leu2a, Leu3a, TA1), B-lymphocytes and their subsets (BA1, BA2, HLA-DR, CR1, sIg), macrophages (TA1, OKM1, anti-human monocyte 1, HLA-DR, CR1), dendritic reticulum cells (CR1, BA2, HLA-DR), interdigitating reticulum cells (HLA-DR, BA1) and Langerhans cells (OKT6, NA1/34). On the basis of the staining pattern of the neoplastic cells with the antibodies used and the nature and number of admixed cells, in particular T-cell subsets, dendritic reticulum cells and macrophages, the NHL could be divided into groups which correspond to the different diagnostic categories of the Kiel classification. Furthermore, the results underlined the existence of intermediate lymphocytic lymphoma as a separate diagnostic category. Histogenetically, the marker pattern of the neoplastic cells and the number and arrangement of the admixed cells are consistent with the view that at least two different lines of B-cell lymphomas can be recognized. One is related to the germinal centre cell reaction (to which B-lymphoblastic (Burkitt type), centroblastic, centroblastic/centrocytic, centrocytic, and intermediate lymphocytic lymphoma, and polymorphic immunocytoma belong) and the other is related to the plasma cell reaction (including chronic lymphocytic leucaemia and lymphoplasmacytoid immunocytoma), whereas B-immunoblastic lymphoma can originate from either line. Thus, polymorphic immunocytoma is a follicle centre cell lymphoma with differentiation into plasma cells rather than a lymphoplasmacytoid immunocytoma with blastic cells.

Antibodies↗

The Hemalog D automated differential counter in the diagnosis of hairy cell leukemia.

We studied the peripheral blood of 37 patients with hairy cell leukemia (HCL) prior to (n = 24) or following (n = 19) splenectomy, in the Hemalog D multi-channel white cell differential counter, to investigate whether the apparatus could contribute to the (early) diagnosis of this entity and to the differential diagnosis of HCL from atypical hairy cell leukemia (AHCL; n = 9), chronic lymphocytic leukemia (CLL; n = 21) and leukemic non-Hodgkin lymphoma of low-grade malignancy (LNHL; n = 19). HCL showed almost invariably monocytopenia, neutropenia and an increased percentage of LUC, with a rather typical picture of the X-Y display of the peroxidase channel. The percentage of hairy cells closely correlated with the percentage of the LUC from the Hemalog D. Discriminant analysis using several parameters of the Hemalog D differential count resulted in a complete separation of HCL from CLL, and a fair, although not complete, distinction of HCL from AHCL and LNHL. It was impossible to discriminate between AHCL and LNHL. The most important discriminating (single or combined) parameters were the absolute monocyte count, the TWBC and the absolute neutrophil number. It is concluded that the Hemalog D is a valuable tool in the (early) diagnosis of HCL and in the discrimination between HCL and other leukemic lymphoproliferative disorders.

Humans↗

Adult T-cell leukemia: a report on two white patients.

Two white European males are reported with adult T-cell leukemia (ATL), a disease first described in Japan, but recently also in the U.K. and U.S.A. Both patients presented with lymphadenopathy, but without a mediastinal mass. In addition, one patient had skin infiltrates and the other had hepatosplenomegaly. Morphologic and ultrastructural examination of the blasts in bone marrow and lymph node biopsy revealed a predominance of polymorphic lymphoid cells with pronounced nuclear irregularities and a semi-mature chromatine pattern. Histopathology of the lymph nodes showed a diffuse infiltration with medium-sized lymphoblasts with irregular nuclei. The blasts in the bone marrow formed E rosettes with sheep erythrocytes, lacked terminal deoxynucleotidyl transferase (Tdt) activity but expressed the Ia-like antigen; although the majority of the cells reacted with a polyclonal anti-T-cell serum, they were negative for OKT3. In one patient a helper/inducer phenotype (OKT4+) was found in the lymphoblasts of bone marrow and lymph node, while in the other only in the lymph node. The difference between bone marrow and lymph node phenotype is discussed. To our knowledge, these are the first two European patients reported with ATL, a disease clearly different from convoluted T-cell acute lymphocytic leukemia.

Adult↗

Effect of the adjuvant dimethyl dioctadecyl ammonium bromide on the humoral and cellular immune responses to encephalomyocarditis virus.

The effects of the adjuvant dimethyl dioctadecyl ammonium bromide (DDA) on the immune responses to encephalomyocarditis (EMC) virus were studied in mice. The humoral response, as measured by appearance of neutralizing antibodies, was slightly enhanced in mice immunized by the intraperitoneal route. Intracutaneously, DDA almost did not affect the humoral response but resulted in distinct enhancement of delayed type hypersensitivity (DH), as measured by the footpad swelling test. DH to EMC virus was found to be antigen-specific and could be passively transferred to normal mice with peritoneal exudate cells from immunized mice. Dose-response curves for DH and humoral antibody responses to EMC virus were not concordant. Low doses induced DH on day 6 without measurable circulating antibodies; high doses gave good antibody responses but suboptimal DH reactions. Immunization conferred a state of resistance to infection with virulent EMC virus. Protection seemed more related to DH than to the prevalence of specific antibodies at the time of infection.

Adjuvants, Immunologic↗

Alternate grazing of horses and sheep as control for gastro-intestinal helminthiasis in horses.

Gastro-intestinal helminth infections of a group of three yearling mare Shetland ponies, which were set-stocked on a small pasture from February until September, were compared with those of a similar group of ponies, which grazed a similar pasture from February to July and subsequently was removed to a pasture which had been grazed by sheep from April to July. In addition both groups were treated with cambendazole when the latter group was removed to the sheep pasture. Pasture larval counts and worm counts demonstrated that the group grazed after the sheep acquired considerably smaller burdens of nematodes of the subfamilies Cyathostominae and Strongylinae, but considerably higher burdens of Trichostrongylus axei than the group which remained on the same pasture. The T. axei infections in the former group caused an increase in the serum pepsinogen levels within two weeks after removal to the sheep pasture followed by a gradual decrease. At necropsy T. axei populations consisted almost exclusively of inhibited early third stage larvae.

Animal Husbandry↗

Paraproteinaemia plus osteolytic lesions in typical hairy-cell leukaemia.

Most cases of hairy-cell leukaemia (HCL) involve proliferations of neoplastic B lymphocytes. In rare cases, M-proteins or osteolytic lesions have been documented in patients with HCL. In this study two patients with typical HCL are reported in whom both paraproteinaemia and osteolytic lesions of the femoral neck developed. In one of the patients the production of the M-protein by hairy cells could be established. In the other patient, at autopsy no signs of myeloma were found. The hairy cells from inside the osteolytic lesion had the same immunological phenotype as hairy cells from the peripheral blood, the spleen, and other parts of the bone marrow. These cases once more confirm the B-cell nature of many cases of HCL, and show that hairy cells can have functional capacities usually attributed to much more mature B lymphocytes, i.e. plasma cells.

Blood Proteins↗

Pharmacokinetics and pharmacodynamics of thiopental in patients undergoing renal transplantation.

The effects and pharmacokinetics of thiopental were studied in eight patients undergoing renal transplantation. The results were compared with findings in a group of patients with normal renal function. No differences were observed in induction doses or between arterial or venous sleep concentrations. The average V3 in the renal failure group was 1441 or 2.5 times the value of the control group (P less than 0.01). The apparent differences indicating longer elimination half-lives and higher serum clearances in the renal patients were not significant. The average binding of thiopental to serum protein shortly after the induction was 83.9% (78.2-88.1) in the renal patients and 89.0% (85.2-91.6) in the control patients (P less than 0.05). The difference in V3 could be explained by the differences in protein binding and when the serum clearance was calculated by using the unbound fraction, this "intrinsic clearance" was significantly lower in the renal failure group (P less than 0.05). Haemodynamic parameters were determined during the initial 5 min. No significant difference was observed between the thiopental-induced changes in stroke volume. Cardiac output was unchanged in both patient groups.

Adult↗

The impact of the composition of the bone marrow graft on engraftment and graft-versus-host disease.

To study the impact of the composition of the bone-marrow graft on engraftment and graft-versus-host disease (GvHD), we analyzed the data on 29 patients with acute leukemia in remission and 11 patients with aplastic anemia. All of them received bone-marrow grafts from HLA matched, MLC nonreactive, sibling donors, were nursed in laminar down-flow isolators with selective gut decontamination, and received GvHD prophylaxis with methotrexate. The number of nucleated cells in the marrow graft/kg body weight of the recipient had no relation with the rapidity of engraftment or with the occurrence and severity of GvHD. The number of hematopoietic progenitor cells (CFUc)/kg had a weak, but significant, correlation with both the number of neutrophils at day 30 post BMT and with the day at which the reticulocytes passed the 10% level. The number of T cells/kg did not show any correlation with either the occurrence or the severity of GvHD. Our data show that the concentration of hematopoietic progenitor cells in the graft correlates with the rapidity of engraftment. However, within the range of numbers of T cells infused in this study, no correlation is present between T cells in the graft and GvHD. Therefore, nearly complete depletion of marrow grafts of T cells is probably necessary to effectively decrease the incidence of GvHD.

Adolescent↗

Development of benzimidazole resistance in a Haemonchus contortus strain in the Netherlands following fenbendazole treatment of ewes at parturition.

In contrast to observations in former years treatment of ewes after parturition with 5 to 7.5 mg/kg fenbendazole was not fully effective in removing Haemonchus contortus. Comparison of the H contortus populations in the lambs of these ewes and those of untreated ewes later in the year revealed that the treatment resulted in fenbendazole resistance and also in side resistance to other benzimidazoles. Though the faecal egg counts of the treated ewes were low, the prophylactic effect of the treatment on the population build up of H contortus in the lambs was very limited.

Animals↗