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Biomedical subjects

M Lorentzen

Publications and source records attributed to M Lorentzen.

36 records · Page 2Linked to original sources
PubMed1983

Histological findings following oestrogen treatment of hereditary haemorrhagic telangiectasia. A controlled double-blind investigation.

In a controlled investigation of 22 patients with hereditary haemorrhagic telangiectasia, an evaluation has been carried out of the connective tissue content of muco-substances prior to and after treatment with oral oestrogen (oestradiol valerate 4 mg. daily). The clinical condition of the patients, all of whom had haemorrhagic anaemia, was evaluated by the frequency of epistaxis and by blood analyses. No effect of treatment could be demonstrated by means of histochemical, clinical or laboratory methods.

Adult↗
PubMed1983

Comparative studies of the function and morphology of 111In- and 51Cr-labelled human platelets.

Comparative studies of the aggregability in vitro and ex vivo, and of the surface/volume ratio of 111In- and 51Cr-labelled human platelets were carried out. The ADP-induced aggregation in vitro of 111In-platelets was superior to that of 51Cr-platelets, as was that of 51Cr-platelets labelled in plasma as compared to 51Cr-platelets labelled in buffer. These differences seemed to be reversed in vivo, as identical collagen-induced aggregation responses were observed ex vivo when comparisons were made between 111In- and 51Cr-platelets, and between labelled and unmanipulated platelets. Morphometric determination of the surface/volume ratios of the labelled platelets indicated a higher degree of platelet activation of 51Cr-platelets labelled in buffer as compared to those labelled in plasma. In this respect, no difference seemed to be present between 111In- and 51Cr-platelets. The results of the ex vivo aggregation studies were unaffected by the time spent by the platelets in the circulation within 24 h post-injection, by platelet isolation yield, and by the medium used in 51Cr-labelling. Our results indicate that it will be possible to conduct comparative studies of simultaneously induced aggregation ex vivo of different platelet populations labelled with 111In and 51Cr.

Blood Platelets↗
PubMed1982

Function and morphology of 111-In-labelled platelets. In vitro, in vivo and ex vivo studies.

111In-labelled human platelets were aggregated with ADP and subjected to ultrastructural morphometric analysis. In addition, the hemostatic function in vivo and the ultrastructural morphology ex vivo of rabbit platelets were examined. The platelet isolation and labelling procedures exerted no certain influence on the aggregation response, and platelet surface/volume calculations did not indicate that platelet activation had taken place. Bleeding time experiments in rabbits indicated that the hemostatic effectiveness of the labelled platelets was unimpaired. Transfused 111In-labelled platelets isolated from the recipient rabbits exhibited fewer electromicroscopic signs of platelet activation than the same platelets prior to transfusion. Our results indicate that the described procedure for isolation and 111In-labelling of platelets induces only insignificant damage to the platelets.

Adult↗
PubMed1981

Metastases to the breast from extramammary carcinomas.

Metastases to the breast from extramammary carcinomas are rare. Only about 200 cases are reported in the literature. Fifteen additional cases are presented here and the literature is reviewed. Two of the patients has primary thyroid carcinoma, two adenocarcinoma of the colon, three bronchogenic carcinoma, four malignant melanoma, one a squamous cell carcinoma of the oesophagus, one an adenocarcinoma of the stomach, one a renal cell carcinoma and one a carcinoid of the terminal ileum. In three cases the breast lesion was the first manifestation of an extramammary cancer. Six of the patients died of disseminated cancer shortly after the breast metastasis was diagnosed. Although breast metastasis may be suspected clinically, exact histological diagnosis is important in order to avoid unnecessary surgical treatment and to guide further therapy.

Adult↗
PubMed1981

Xanthogranulomatous pyelonephritis. An immunohistochemical and ultrastructural study on the occurrence of bacteria and bacterial antigen.

Nine kidneys with typical xanthogranulomatous pyelonephritis (XP) involvement were investigated on the occurrence of bacteria, bacterial fragments and antigen, in light microscopy using Gram staining and immunohistochemistry, and by electron microscopy. The present study did not reveal any occurrence of bacteria, bacterial fragments or antigen. It is concluded that the xanthogranulomatous reaction in man represents a resorption phenomenon, and not an immunological reaction to bacteria or bacterial antigen.

Animals↗
PubMed1980

Giant cell tumor of the ovary.

A 31 year old woman with primary sterility was found, at operation, to have endometriosis of the Fallopian tubes and a giant cell tumor of the ovary, histologically indistinguishable from giant cell tumor of bone. The tumor is considered to be primary and benign, with a follow-up period of 4 1/2 years and no signs of recurrence or malignancy.

Adult↗
PubMed1980

Congenital ependymoblastoma.

An ependymoblastoma with widespread dissemination within the central nervous system of a stillborn, premature male infant is reported.

Brain Neoplasms↗
PubMed1980

Quantitative studies of the gastrin-producing cells of the human antrum. A methodological study.

The antral gastrin-producing cells (G-cells) have been identified by the indirect immunoperoxidase technique in two antrum preparations removed due to a recurrent duodenal and gastric ulcer. Morphometric principles were applied to the G-cells with determination of their volume density, numerical density, and mean cell volume. The study showed that within-observer variation, between-observer variation and within-patient variation were negligible, provided at least 200 G-cells were counted. A biopsy material can be used, as well as larger tissue blocks, when this minimum sample size is respected. A method for estimating the total G-cell population and the total G-cell volume in the antrum was developed. In the antrum removed due to a gastric ulcer the number of G-cells was 190 x 10(6) and their total volume 176 mm3.

Cell Count↗
PubMed1980

Xanthogranulomatous pyelonephritis.

Evaluation of clinical, radiological and pathological data from 10 adult patients with xanthogranulomatous pyelonephritis has been carried out. There are no pathognomonic diagnostic features, but the majority of patients present with a previous history of recurrent urinary tract disorders. Obstruction and infection are essential pathogenetic factors, but it is suggested that immunologic factors are also play a part. The treatment is nephrectomy, as correct diagnosis cannot be established preoperatively, and as the condition is often misinterpreted as renal carcinoma. A definite diagnosis can only be obtained from pathologic examination with demonstration of the characteristic inflammatory xanthogranulomatous reaction.

Adenocarcinoma↗
PubMed1979

Urinary bladder tumours in children. Case report of inverted papilloma.

A short review is given of tumours of the urinary bladder in children, and the first case of an inverted papilloma in a child is reported. The tumour was situated in the trigone of the bladder and was successfully extirpated, with no recurrence at follow-up 9 months later. It was histologically typical of these tumours. The 105 patients described in the literature had an average age of 55 years, whereas the present case is the first to be described arising during the first two decades of life. The most frequent symptoms of such tumours are haematuria and urinary obstruction. It is suggested that the treatment of choice is transurethral excision. The term Brunnian adenoma is recommended for use with this tumour, in order to avoid the impression given by the name papilloma of the bladder, that the tumour is malignant.

Age Factors↗
PubMed1978

Rhabdomyosarcoma of the larynx. Report of two cases and a review of the literature.

The rhabdomyosarcoma is a relatively rare tumour form. Two cases in the larynx--a site which is extremely rare--are reported. So far, only 9 cases have been described and documented, and of one of our cases seems to be the first of the alveolar type found at this site. Diagnostic and differential-diagnostic considerations are discussed. Hoarseness is the commonest and earliest symptom. As stated by most authors, the treatment should be radical operation, often with laryngectomy, supplemented by irradiation and chemotherapy.

Adolescent↗
PubMed1977

The incidence of malignant transformation in giant pigmented nevi.

151 patients with benign giant pigmented nevi registered in the Danish Health system during the 60-year period 1915-75 were retrieved via the national register. A questionnaire was sent to all surviving patients asking for information about their health and especially whether they had had any treatment or had observed any changes in the nevus. All of the patients replied to the questionnaire. No patients had been cured from malignancy or were alive with known malignancy. Three patients had died from malignant melanoma during the period of observation. These case histories are reported. It is calculated that 4.6% of the patients with congenital giant nevi should be expected to develop malignant melanoma provided the incidence is the same in all age groups. Some uncertainty remains on account of the limited number of cases and an unsettled question about a higher incidence in childhood.

Adult↗