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Biomedical subjects

J Knop

Publications and source records attributed to J Knop.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Radiotherapy of solitary and multiple eosinophilic granulomas of bone (stage I)].

Between 1957 and 1990 15 patients with solitary (stage Ia by Greenberger) and 2 patients with multiple (stage Ib) eosinophilic granuloma of the bone were treated by radiotherapy in 18 locations after previous surgery. The doses applied varied from 6 Gy to 42 Gy (median for patients under 18 years: 8 Gy, for patients over 18 years: 30 Gy). Median follow-up was 9 years (range, 0.3-33 years). Local control rate and survival were 100%. Three patients with granuloma developed a second granuloma within 13 years after primary diagnosis (two bone manifestations, one cutaneous manifestation). Long-term follow-up of patients with solitary eosinophilic granuloma is necessary.

Adolescent↗
PubMed1991

[Eosinophilic cellulitis--clinical and histological aspects].

Eosinophilic cellulitis (Wells' syndrome) is a rare skin disease whose aetiology is still unknown. The onset is acute, and different disease stages may exist simultaneously during the course. Histological examination shows flame figures as a characteristic, but not pathognomonic, feature. In later stages the infiltrate adopts granulomatous characteristics. Malignant haematological disorders, which frequently occur with this disease, should be excluded.

Cellulitis↗
PubMed1990

Scintigraphic evaluation of tumor regression during preoperative chemotherapy of osteosarcoma. Correlation of 99mTc-methylene diphosphonate parametric imaging with surgical histopathology.

The effect of preoperative chemotherapy (PCT) on the uptake of 99mTc-labeled diphosphonates into tumor bone was quantitatively assessed from serial scan studies of 30 osteosarcomas and correlated with the histomorphological changes determined from the surgical specimens. The parametric images of the tumor blood pool and labeled methylene diphosphonate (99mTc-MDP) plasma clearance by the tumor bone enabled a sensitive distinction to be made preoperatively between a good (greater than 90% tumor cell destruction) and a poor (less than 90% tumor cell destruction) tumor response. Overall accuracy in presurgical prediction of tumor regression was found to be 88% and 96% for the blood pool and 99mTc-MDP clearance measurements, respectively (P less than or equal to 0.0004). In addition, it proved possible to localize resisting areas of viable tumor up to 1.0 cm in diameter. Even at the half-way stage of PCT, a poor response could be reliably predicted (overall accuracy 91% and 100%, respectively; P less than or equal to 0.011). Therefore, 99mTc-MDP parametric imaging is a highly sensitive and specific modality for an objective and accurate assessment of tumor regression during PCT of osteosarcoma.

Adolescent↗
PubMed1990

Immunologic effects of interferon.

Interferons can be defined as a family of induced proteins sharing the capacity to exert pleiotropic effects on cell functions and to render cells resistant to virus infection. They are activating genes coding for a number of enzymes, most of which have not yet been characterized, and also by enhancing the synthesis of cell surface components. This enables interferons to modulate the immune response at different levels. This article will focus on the effects of interferon on antigen presentation, regulation of the immune response, activation of macrophage functions, and on its role in the pathogenesis of some diseases.

Animals↗
PubMed1990

Antigens of the major histocompatibility complex in patients with chronic discoid lupus erythematosus.

The frequencies of the major histocompatibility complex class I, class II and class III antigens were determined in 130 patients (88 women and 42 men) with chronic discoid lupus erythematosus, and compared with those of 764 healthy controls. A significant increase in HLA-B7 (38.0% in the patients vs. 25.8% in the control group), HLA-B8 (29.5% vs. 17.4%), HLA-Cw7 (58.9% vs. 26.1%), HLA-DR2 (46.9% vs. 29.7%), HLA-DR3 (32.0% vs. 19.4%), HLA-DQw1 (76.6% vs. 60.5%), and a decrease in HLA-A2 (41.9% vs. 55.7%) was found. The calculated relative risk values for the respective antigens markedly increased when two or more antigens were present in one patient, with a maximum relative risk value of 7.4 for the combinations of HLA-Cw7, DR3, DQw1 and HLA-B7, Cw7 and DR3, which were found in 17.2% of the patients and in only 2.3% of the controls.

Chronic Disease↗
PubMed1990

Childhood antecedents of antisocial behavior: parental alcoholism and physical abusiveness.

Hierarchical logistic regression was used to assess the independent and interactive effects of paternal alcoholism and physical child abuse on antisocial behavior in young adult men. Men with alcoholic fathers (N = 131) did not report or exhibit more antisocial behavior than comparison subjects (N = 70). Men with physical abuse histories, however, reported more aggressive and antisocial behaviors during a clinical interview and were rated by a clinical interviewer as more likely to act out aggression. Arrest records did not distinguish the groups. There was no evidence that paternal alcoholism and childhood victimization interacted to increase the risk of antisocial behavior.

Acting Out↗
PubMed1990

Fat-storing hamartoma of dermal dendrocytes. Clinical, histologic, and ultrastructural study.

A 30-year-old man is described who since birth had a peculiar symmetrical red-brown micronodular cutaneous plaque. Within the slightly raised plaque, small firm nodules were palpable. Histologic examination revealed phagocytic cells with the appearance of histiocytes between the collagen fibers of the reticular dermis. Immunohistochemical and electron microscopic examination confirmed that the cells of the plaque were dermal dendrocytes with phagocytic activities. The existence of the lesion since birth, the phagocytosis of lipid droplets by the cells, and the lack of associated metabolic disturbances suggest a fat-storing hamartoma of dermal dendrocytes that does not correspond to a known fat-storing or fat-producing tumor.

Adult↗
PubMed1989

[Forensic examination in cases of rape and attempted rape reported to the police. A study of a new procedure used in the municipality of Copenhagen].

Increasing recognition of the late psychological sequelae of rape has resulted in alteration in the practice of medico-legal investigation in the Municipality of Copenhagen with the offer of psychological treatment free of charge. During a period of two years, 100 women were examined and 20% of these accepted psychological treatment. The percentage of women seeking psychological treatment was greatest among those who were examined in the new premises attached to the psychiatric clinic of the University Hospital. These premises satisfy a number of needs but are not optimal. A recent committee publication proposes a special clinic for victims of sexual assaults not only the women who have reported the case to the police but also those who have not reported it. A department such as this must be considered to be the optimal solution for solution of the requirements of victims of rape. The 20 women who received psychological treatment presented psychological symptoms of the same type and degree as described in other investigations, and these symptoms were not found to have any definite relation to the nature of the rape, its violence or defensive actions made by the women. As compared with the frequency of psychological sequelae described in the literature, only few women sought psychological aid. The explanation of this may be problems in organization at the commencement of the new arrangement.

Adolescent↗
PubMed1989

Induction of procoagulant activity in human epidermal cells.

We have studied the induction of procoagulant activity (PCA) by lipopolysaccharide (LPS) in cultured human epidermal cells. Single cell suspensions of epidermal cells were prepared from surgical specimens and stimulated for 24 h with LPS (100 micrograms/ml). PCA was determined by one-stage clotting assay. Stimulation of the epidermal cells with LPS resulted in a significant reduction of the clotting time (approx. 30%) as compared with the nonstimulated controls. Further analysis of the induced PCA showed that it did not require factors of the intrinsic pathway of the clotting cascade (factors XI and XII). Similarly, PCA was not affected by factor IX-deficient plasma but required factors II, VII, and X for its full expression. PCA was inactivated by treatment with phospholipase C but not by heating to 56 degrees C. These data indicate that the epidermal cell PCA resembles tissue factor-like activity, activating the extrinsic clotting pathway. Elimination of Langerhans' cells from the epidermal cell suspension by antibody and complement-mediated lysis did not result in a reduction of PCA in the remaining epidermal cells, indicating that keratinocytes were most likely the producer cells. Induction of PCA on the cell membrane surface of epidermal cells may be an early event resulting in the initiation of a local inflammatory reaction.

Blood Coagulation Factors↗
PubMed1988

Ultrastructural cytochemical visualization of chromium in the skin of sensitized guinea pigs.

Using a modified sulfide silver method for electron microscopy, the intraepidermal and intracellular localization of epicutaneously applied potassium dichromate was investigated at varying times in sensitized and nonsensitized guinea pigs. The hapten penetrated rapidly into the epidermis. There was a homogeneous extra- and intracellular staining of the keratinocytes in the upper epidermis. The basal and suprabasal cells, by contrast, exhibited a predominant extracellular and plasma membrane localization of the silver grains. This membrane staining pattern was also observed in the Langerhans cells showing cellular and endocytotic activation in the sensitized animals. No specific cellular uptake of the hapten by the Langerhans cells was found. These results demonstrate that the epicutaneous application of chromate resulted in a characteristic intraepidermal distribution which may be related to the epidermal conversion of the hexavalent chromate to the immunogenic trivalent form. Moreover, the absent intracellular localization of the hapten in the activated Langerhans cells supports the notion that contact allergens can be presented to T cells without prior intracellular processing.

Animals↗
PubMed1988

Pattern reversal visual evoked potentials after alcohol administration among men at risk for alcoholism.

The P100 component of the pattern reversal visual evoked potential was used to compare men at high risk for alcoholism and control subjects before and after a low (0.5 g/kg) dose of ethanol. The high risk and control subjects did not differ in age, self-reported ethanol consumption, or estimates of ethanol metabolism rates, but changes in the occipital P100 latency differentiated them following ethanol administration. The P100 latency changes that distinguished high risk from control subjects were lateralized and provide preliminary evidence that perceptual visual stimulus processing is differentially affected in the two groups following ethanol administration.

Adult↗
PubMed1988

[Roentgen morphology of bone metastases of breast cancer as affected by antineoplastic therapy].

The changes in bone metastases from carcinoma of the breast induced by treatment have been analysed from their radiological appearances in a series of 58 patients and for an average period of 7.2 years. Indicators of regression are recalcification or re-ossification of primary osteolyses (46.8%), the development of marginal sclerosis round the defect (15.9%) and lack of progression over a period of 9 to 12 months (11.6%). Decreased sclerosis in primary osteosclerotic metastases (9.4%) may also be evidence of regression. Primary osteolytic/osteosclerotic metastases behave similar as osteolytic lesions. Recurrence or progress of tumour produces new metastases (39.6%), progressive osteolysis (26.6%), sclerosis (7.3%) and increased tumour size (15.4%).

Adult↗
PubMed1988

Ultrastructural localization of 2,4-dinitrophenyl groups in mouse epidermis following skin painting with 2,4-dinitrofluorobenzene and 2,4-dinitrothiocyanatebenzene: an immunoelectron microscopical study.

The ultrastructural localization of 2,4-dinitrophenyl (DNP) groups in mouse epidermis after epicutaneous application of the contact sensitizer 2,4-dinitrofluorobenzene (DNFB) and the tolerogen 2,4-dinitrothiocyanatebenzene (DNTB) was investigated at varying times using immunoelectron microscopy with the protein A - gold technique. After application of DNFB, there was a homogenous cytoplasmic labeling of all epidermal cells. The intracellular localization of the DNP groups was not restricted to cytoplasmic organelles belonging to the endocytotic - lysosomal system. The numerous endocytotic organelles, Birbeck granules, and lysosomes of the Langerhans cells (LCs) typically observed after application of contact sensitizers also did not show an increased number of gold particles. Skin painting with DNTB resulted in a similar distribution and time-course of immunolabeling, but this compound did not induce cellular and the endocytotic activation of LCs as seen after DNFB application. These results demonstrate that contact sensitizers do not require specific cellular uptake and intracellular processing by the endocytotic - lysosomal compartment of the LCs before membrane presentation. However, a cellular and endocytotic activation of the LCs by haptens may be an important mechanism for T effector cell activation.

Animals↗