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Biomedical subjects

J Jansen

Publications and source records attributed to J Jansen.

At least 289 records · Page 16Linked to original sources
PubMed1981

Splenectomy in hairy cell leukemia: a retrospective multicenter analysis.

To study the effect of splenectomy in hairy cell leukemia, we initiated a retrospective multicenter analysis. A series of 391 patients, contributed by 22 centers (median: 15 cases per center, range 2--130), was analyzed. Since comparison of the data from these centers showed few significant differences, the data were pooled. Factors that proved to have prognostic value at the time of diagnosis was significantly longer in the splenectomy group (n = 225) than in the nonsplenectomy group (n = 166) (P less than 0.0001). When subgroups were analyzed, no difference in survival time was found between splenectomized and splenectomized patients having an age greater than 60 years, symptoms greater than 12 months, spleens less than 4 cm under costal margin, hemoglobin levels greater than 12 g/dl, neutrophils greater than 500/mm3, or platelets greater than 100,000/mm3. After the operation, the platelet count usually increased to acceptable values, whereas the neutrophil count increased less often. Patients with Hb greater than 11 g/dl, neutrophils greater than 1,000/mm3, and platelets greater than 100,000/mm3 after splenectomy, survived longer than patients with a less complete response to the operation (P less than 0.01). In patients with definite splenomegaly and pancytopenia, splenectomy seems to be beneficial. However, in patients without distinctly enlarged spleens, other therapeutical modalities should be considered.

Adult↗
PubMed1981

Malignant lymphoma of true histiocytic origin: histiocytic sarcoma. A morphological, ultrastructural, immunological, cytochemical and clinical study of 10 cases.

Ten tumors of true histiocytic origin (Histiocytic Sarcoma) are presented. The tumor cells were identified as histiocytes by immunological, cytochemical and ultrastructural criteria (cytoplasmic lysozyme activity, presence of C3 and Fc gamma receptor, strong acid phosphatase and alpha-naphthyl acetate esterase activity, presence of lysosomes, absence of cell junctions and evidence of phagocytosis). The tumors identified in this way showed the following histological characteristics: diffuse proliferation of large tumor cells with ample cytoplasm, containing granular or occasionally diffuse diastase resistant PAS positive material, erythrophagocytosis, and haemosiderin pigment. The large or enormous nuclei were irregular, with occasional deep indentations, sharply defined nuclear membrane, coarse chromatin and conspicuous nucleoli. Despite the uniformity of these criteria differences in presence of alpha 1-antitrypsin, alpha 1-antichymotrypsin and 5 Nucleotidase activity and the number of lysosomes in the cytoplasm were found. The findings are suggestive of a spectrum of cytological in these Histiocytic Sarcomas. The clinical picture ranged from monolocalization in a lymphoid organ to that of a diffuse Malignant Histiocytosis. The relationship between good response to therapy and complete remission and the absence of alpha 1-antitrypsin and a high number of lysosomes is discussed.

Adult↗
PubMed1981

Anti-thymocyte globulin (ATG) can eliminate platelet refractoriness.

Of the 14 patients with aplastic anaemia treated in our hospital with anti-thymocyte globulin (ATG), four were refractory to random platelets before therapy due to the presence of leucocyte antibodies. In contrast to the ten nonrefractory patients in whom no success was obtained, three of the four refractory patients showed haematological improvement after ATG. Additionally, two patients could be substituted again with random platelets. The other two hardly needed platelet-transfusions after ATG, and they were given HLA-compatible platelets. To determine the degree of immunosuppression, these four patients were tested for the presence of antibodies against leucocytes and two endemic viruses, i.e., mumps and rubella virus. Before ATG, all sera reacted with almost the whole leucocyte testpanel. After treatment, the leucocyte antibodies disappeared completely in three patients. In one patient there was no dramatic change. In all patients, however, the antibody-titre against the mumps and rubella viruses remained constant and there was only a slight decrease in total IgG content in the three "suppressed" patients. We conclude that it might be worthwhile to study systematically the selective immuno-suppressive effect of ATG.

Adult↗
PubMed1981

Histologic evaluation of probe penetration during clinical assessment of periodontal attachment levels. An investigation of experimentally induced periodontal lesions in beagle dogs.

The purpose of this study was to evaluate histologically the extent and characteristics of the penetration of a periodontal probe during clinical assessment of loss of periodontal attachment in three different situations: (1) experimental mild gingivitis, (2) experimental severe periodontal inflammation and (3) experimental moderate periodontal inflammation. Mild gingivitis was obtained by merely allowing plaque to accumulate on the teeth. Severe periodontal inflammation was created using copper bands for a period of 3 weeks followed by placement of cotton ligatures for another 11 weeks. Moderate periodontal inflammation group was obtained by allowing the experimental defects to recover for a period of 3 to 31 weeks. At different times gutta percha imitations of a thin periodontal probe were inserted into the pockets using a gentle but unknown force. Histologic observation in 30 specimens showed that epithelium was always present around the probe tip, in most instances forming a continuous layer of epithelial cells. Histometrical analysis showed that in mild gingivitis the probe tip failed to reach the apical termination of the junctional epithelium (mean = -0.84 mm). In severe periodontal inflammation the tip of the probe went past this point (mean = +0.50 mm), while in moderate periodontal inflammation the probe tip came closest to the apical termination of the junctional epithelium (mean = -0.05 mm). It is concluded that the epithelial lining of a pocket stays intact, even in severe periodontal inflammation where the probe tip is situated apical to the apical termination of the junctional epithelium, indicating that during clinical probing the periodontal tissues are compressed and displaced but not perforated. It is also concluded that in beagle dogs the extent of probe penetration in experimentally inflamed periodontal tissues is dependent upon the degree of inflammation.

Animals↗
PubMed1981

Microscopic evaluation of pocket depth measurements performed with six different probing forces in dogs.

This study investigates the relationship between probing force and probe penetration into the periodontal tissues in pockets with overt gingivitis and in pockets with minimal gingival inflammation. In eight dogs experimental periodontal tissue breakdown was induced during a period of 14 weeks. The dogs were then distributed over two groups of four dogs each. In group the dogs were subjected to meticulous tooth cleaning once every day for a period of 3 weeks. The dogs in the second group did not receive any oral hygiene measures. Next, wooden probes were inserted, mesial and distal to each premolar. In each dog six different probing forces were used. Microscopic examination showed that, in the brushed group, epithelium was always present between the probe tips and the connective tissue. In the nonbrushed group presence of epithelium was found in 21 of 23 specimen. In both groups of dogs it was found that, with increasing probing forces, the location of the tips of the probes changed from a position occlusal to the most coronal connective tissue fibers to a position apical to the most coronal connective tissue fibers. With light probing forces it appeared that in the nonbrushed group the tips of the probes were located more apically. When greater probing forces were used, no differences between the brushed and the nonbrushed group were found. It is suggested that, using a probe of 0.63 mm in diameter, the optimal force level for clinical pocket measurements is about 0.75 N, or in other words, the optimal probing pressure is about 240 N/cm2.

Animals↗
PubMed1981

Anti-thymocyte globulin effective in the treatment of aplastic anemia does not stimulate granulocyte precursor cells.

To find out whether the preparations of anti-lymphocyte or anti-thymocyte globulin (ATG), successfully used in our center for the treatment of patients with aplastic anemia, were stimulatory for hematopoietic precursor cells, we studied the effect on CFUC in 30 normal bone marrow samples. Although in 2 out of 30 cases stimulation was observed, the overall result for both the horse anti-lymphocyte globulin and the rabbit anti-thymocyte globulin was dose-dependent and complement-dependent inhibition. Neither in the absence, nor in the presence of complement was there any indication of consistent stimulation of CFUC. When bone marrow was depleted of E-rosette forming cells, the incubation of the depleted fraction with ATG did not result in stimulation. The incubation of the E-rosette positive fraction with ATG, followed by the addition of these treated cells to untreated E-rosette depleted cells was equally ineffective in giving any stimulation of CFUC. Our data suggest that the effect of ATG in the treatment of aplastic anemia is not due to direct stimulation of hematopoietic precursor cells.

Anemia, Aplastic↗
PubMed1980

Probing force in relation to probe penetration into the periodontal tissues in dogs. A microscopic evaluation.

In four beagle dogs, periodontal tissue breakdown was experimentally induced around the upper left premolars (P1, P2 and P3). Wooden probes were inserted mesially and distally to each premolar. Six different probing forces were used in each dog. Microscopic examination showed: 1) the presence of an intact layer of epithelium between the probe tip and the connective tissue in 21 of 23 specimens. 2) an increasing compression of the connective tissue with increasing probing force, without penetration of the probe tip into the connective tissue.

Animals↗
PubMed1980

Extreme potassium loss in a patient with severe graft versus host disease.

A 19-year-old male, suffering from post-hepatitis aplastic anaemia, was transplanted with bone marrow cells from his HLA-identical, MLC non-reactive brother. Haematological recovery ensued, but the patient also developed grade IV graft-versus-host disease (GVHD). In addition to involvement of skin, liver and gut, the kidney seemed affected by GVHD since the patient has hypokalaemia and severe hyperkaluria. Other causes of urinary potassium loss were excluded. The amount of potassium loss correlated well with the severity of the GVH-reaction. Although coagulation disorders prohibited a kidney biopsy, the clinical course suggested GVHD to be the cause of the urinary potassium loss.

Adult↗