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Biomedical subjects

M Jacobsen

Publications and source records attributed to M Jacobsen.

At least 91 records · Page 5Linked to original sources
PubMed1981

Quartz and pneumoconiosis in coalminers.

In a routine survey of 623 miners in one colliery, 21 men, an unusually high number, showed radiological progression of simple pneumoconiosis in spite of generally low exposures to mixed coalmine dust. Comparison of the dust exposures of the 21 men with those of matched controls without pneumoconiosis showed highly significant differences in the proportion of quartz in the mixed dust to which they had been exposed. Quartz exposure may be an important factor in the development and rapid progression of coalworkers' pneumoconiosis. Some indication of the levels of quartz exposure which are likely to be hazardous is given.

Air Pollutants, Occupational↗
PubMed1981

Distribution of tumor-associated antigens in the various histologic components of germ cell tumors of the testis.

The various histologic components of 39 germ cell tumors of the testis were studied with indirect labeled immunoperoxidase technique for the presence of the following tumor-associated antigens: alpha-fetoprotein (AFP), alpha 1-antitrypsin (A1AT), chorionic gonadotropin (HCG), specific pregnancy beta 1-glycoprotein (SP1), human placental lactogen (HPL), carcinoembryonic antigen (CEA), and ferritin (Fe). Embryonal carcinoma components were positive for AFP in 9/16, for A1AT in 6/16, for CEA in 2/16, and for Fe in 14/16. All yolk-sac tumor components were positive for AFP and Fe, and 8/13 contained A1AT and 2/13 CEA. Epithelium in teratoid components was positive for AFP in 5/14 cases, for A1AT in 8/14, for CEA in 7/14, and for Fe in 8/14. Syncytial trophoblast in choriocarcinoma components and syncytial giant cells were all positive for HCG, SP1 and HPL. In addition, tumor giant cells in two nonseminomatous tumors and in one seminoma contained HCG. Otherwise, all pure seminomas were negative for all antigens, except for Fe, which was positive in 12/16 cases. Demonstration of this functional aspect of germ cell tumors of the testis may clarify problems of classification and elucidate histogenesis. Furthermore, immunohistochemical demonstration of tumor-associated antigens is of value in the management of the patient as an indicator of which tumor markers should be used for monitoring the treatment. In addition, the presence of tumor-associated antigens may be used in prognostic evaluation.

Antigens, Neoplasm↗
PubMed1981

Classification of chest radiographs for epidemiological purposes by people not experienced in the radiology of pneumoconiosis.

Under controlled conditions 16 people (eight non-medical) inexperienced in the radiology of occupational lung diseases repeatedly classified 300 selected chest radiographs using the 1971 ILO U/C International Classification of Radiographs of Pneumoconioses. Eight experienced medical readers had previously classified 220 of the selected radiographs for profusion of small rounded opacities. Variability among readers was greater in experimental panels than among the experienced readers. But the average consistency between pairs of novice readers in their use of the 12 categories of profusion for the same radiographs was similar (about 29%) to the average consistency among the experienced readers. Subsequent work with nine of the participants showed that eight of them were able to produce classifications of coal miners' chest radiographs that correlated well with estimates the miners' exposures to respirable coal mine dust. It is concluded that the ILO classification scheme provides a sound descriptive system for recording the appearances of chest radiographs. Under controlled conditions the scheme may be used for epidemiological studies by those with no specialist knowledge or clinical experience. This presupposes that the radiographs concerned will have been examined previously for diagnostic purposes by a suitable qualified physician.

Adolescent↗
PubMed1981

An immunohistochemical study of a series of plasma proteins in the early human conceptus.

A 20-day-old human conceptus was studied by the indirect immunoperoxidase technique for the presence of a series of plasma proteins: prealbumin (PA), albumin (ALB), alpha-fetoprotein (AFP), alpha 1-antitrypsin (A1AT), carcioembryonic antigen (CEA), immunoglobulin G (IgG), ferritin (FER), transferrin (TR), fetal haemoglobin (HbF), human chorionic gonadotropin (HCG), human placental lactogen (HPL) and pregnancy specific beta 1-glycoprotein (SP1). In the embryo only FER and TR were found. The yolk sac was positively stained for several proteins: PA, ALB, AFP, A1AT, IgG, FER, TR and HbF were demonstrated in the endodermal cells and PA, ALB, IgG and TR in the mesothelial cells. The syncytiotrophoblast of the chorionic villi were heavily stained for all the placental proteins. HCG and HPL were additionally demonstrated in the cytotrophoblast. The Hofbauer cells of the chorionic and villous stroma stained positively for A1AT and FER. TR appeared as a characteristic band on the apical surface of the syncytiotrophoblast. The findings indicate that the yolk sac is the principle source of some of the plasma proteins also in the very early conceptus and the assumption that the yolk sac is the functional antecedent of the liver is supported. The distribution of the various placental proteins is in accordance with the present knowledge that the syncytiotrophoblast is the major site of synthesis of these proteins. Finally correlation of functional aspects of embryonic structures and germ cell tumours is recommended.

Blood Proteins↗
PubMed1980

The effect of fixation and trypsinization on the immunohistochemical demonstration of intracellular immunoglobulin in paraffin embedded material.

Using an indirect labelled immunoperoxidase technique the influence of fixation time on the antigenicity of intracellular immunoglobulin in lymphoid tissue fixed in buffered formalin has been investigated. Within a fixation period of 96 hours a decrease of 15% of stainable immunoglobulin containing cells was found, for every 24 hours the fixation time was prolonged. By comparing sections from tissue fixed in buffered formalin and selected fixatives (Lillie's AAF, Bouin's fluid, Clarke's fluid and 96% ethanol 1% acetic acid (E--A) processed at 4 degrees C and at 25 degrees C) an increased number of stained immunoglobulin containing cells was found in tissue fixed in Lillie's AAF, Bouin's fluid, Clarke's fluid and E--A processed at 4 degrees C. No difference was found between tissue fixed in buffered formalin and E--A processed at 25 degrees C. In addition the effect of pretreatment of the sections with trypsin on the number of stainable immunoglobulin containing cells was investigated. Trypsinization of sections from formalin fixed material increased the number of stainable cells substantially. No essential effect was seen on tissue fixed in Lillie's AAF and Bouin's fluid. In contrast trypsin treatment of sections from tissue fixed in Clarke's fluid and E--A completely destroyed the tissue. No differences were observed between different immunoglobulin classes examined as regards the effect of fixation time, fixatives and trypsinization.

Cell Count↗
PubMed1980

Pulmonary blastoma. A clinico-pathological study of eleven cases.

Eleven cases of pulmonary blastoma are presented, the largest series reported from one department to date. The frequency of pulmonary blastoma was found to be 0.5 per cent of all primary lung cancers. The variegated histologic appearance of the tumour and the diverging metastatic pattern are described in detail. In light of the complex histological picture and the biological behavior a suggestion of the histogenesis of pulmonary blastoma is attempted.

Aged↗
PubMed1979

Immunohistochemical evidence for an intracellular localization of plasma proteins in human foetal choroid plexus and brain.

The intracellular distribution of plasma proteins in human foetal choroid plexus and brain was investigated by immunohistochemistry. Small groups of cells or single scattered cells in the epithelial layer of the choroid plexus exhibited positive staining for alpha-fetoprotein, albumin and transferrin, whereas prealbumin was found in the majority of the epithelial cells. Numerous nerve cells in the cerebral wall and in various brain stem nuclei were positively stained for alpha-fetoprotein, albumin and prealbumin. All appropriate controls were negative. The presence of plasma proteins within choroid plexus epithelial cells suggest that these proteins are transported from blood to CSF by a transcellular route across the choroid plexus epithelium. The intracellular distribution of plasma proteins in developing neurons may indicate that these proteins play some important role in neuronal differentiation or development.

Blood Proteins↗
PubMed1979

[26 years of research in pneumoconiosis in the field of British coal mines. Contribution of that research to the epidemiology of pulmonary disorders in miners].

Events leading to the start of the Pneumoconiosis Field Research in 1953 are reviewed. Research methods are outlined, progress is described, and the main results are summarised. Three medical surveys were conducted at approximately five-year intervals in 24 coal mines. A further two quinquennial surveys took place at 10 of them, thus completing 20 years' observations. Individual miners' exposures to dust have been measured throughout the periods of study and earlier exposures have been estimated. The dust exposure have been expressed as cumulative timeweighted mass concentrations of dust in the respirable range. Correlations have been demonstrated between this index of exposure and (a) risks of developing various degrees of simple pneumoconiosis, (b) the occurrence of chronic bronchitis symptoms, (c) level of breathing capacity, and (d) among miners with no pneumoconiosis, mortality attributed to respiratory diseases generally, chronic bronchitis and emphysema in particular, and to cancers of the digestive organs. Exposures to quartz amounting to less than about 10 per cent of mixed coal mine dust do not generally affect the probability of developing simple pneumoconiosis. But there is evidence that some miners may show unusual radiological changes over ten years when exposed to dust with a relatively high quartz content. Current work includes continuation of mortality studies and follow-up surveys of miners no longer working at the research collieries. The inter-disciplinary nature of the research team is emphasized and there are suggestions for further work on unresolved problems.

Coal Mining↗
PubMed1979

Immunohistochemical demonstration of intracellular immunoglobulin in formalin fixed, paraffin embedded sections, as staining method in diagnostic work.

52 specimens from 34 patients with multiple myeloma and 3 cases with reactive plasmacytosis were stained by the 2-step labelled or 3-step unlabelled immunoperoxidase (IP) technique for demonstration of intracellular immunoglobulin in order to test the utility of these methods as staining methods in routine diagnostic work. The specificity of the methods was high as agreement between IP staining and serumanalysis for M-component was achieved in 27 out of 28 cases, where complete serumanalysis were available. Interpersonal variation in interpretation of the staining results was low. With optimal dilutions of antisera the evaluations of the examiners were concordant in 51 out of 52 specimens. By comparing the different tissue specimens the best result was obtained with iliac bone biopsies both concerning IP staining and morphological preservation. No difference was observed between results obtained by the 2-step labelled and 3-step unlabelled IP techniques.

Bone Neoplasms↗