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Biomedical subjects

H Laaff

Publications and source records attributed to H Laaff.

At least 19 recordsLinked to original sources
PubMed1992

[HMB 45 positive balloon cells in combined nevi].

The combined naevus is made up of two components, one resembling a melanocytic naevus, the other a blue naevus. Clinically, these naevi do not give any obvious cause for concern. Histological examination shows that the combined naevus consists of a superficial melanocytic naevus and a deep-seated spindle cell blue naevus. There is a rare variant in which the pigmented spindle cells of the "blue" naevus are replaced by large balloon cells varying in melanin content. These combined naevi, because of the large cells with abundant cytoplasm, closely resemble malignant melanoma. As a further aid to diagnosis we used the monoclonal antibody HMB 45. In our study, the vesicular cells in all seven combined naevi examined reacted strongly with HMB 45. It is suggested that HMB 45 is not always helpful in differentiating between melanoma and naevi.

Antibodies, Monoclonal↗
PubMed1992

[Cutaneous angiosarcoma after telecobalt irradiation].

Cutaneous angiosarcomas are rare neoplasms. They occur most frequently on areas of skin exposed to sunlight in the elderly, or in long-standing lymphoedema (Stewart-Treves syndrome). Radiation is an important aetiological factor. With only 1 exception, the 34 published cases of cutaneous angiosarcoma on the trunk were caused by irradiation of internal tumours, occurring between 4 and 50 years after the irradiation treatment. The prognosis quoad vitam is poor. The tumours should be removed surgically. When they are inoperable, irradiation is an alternative therapeutic option. The aim of this paper is to show the histological differential diagnosis of cutaneous angiosarcomas and to demonstrate problems with the treatment.

Abdomen↗
PubMed1992

[Grzybowski type eruptive keratoacanthomas and ectropion. A therapeutic problem].

Eruptive Grzybowski-type keratoacanthoma is a rare variant of multiple keratoacanthoma and is not accompanied by internal malignancies. Up to now only 16 cases of eruptive Grzybowski-type keratoacanthoma have been described in the literature. Eruptive and solitary keratoacanthomas cannot be distinguished histologically. The multiplicity of skin lesions may be due to a genetic background. Our patient presented with multiple eruptive keratoacanthomas, ectropion and a mask-like face. Conservative treatment, e.g. with etretinate, did not lead to any improvement of symptoms in this case. Therefore surgical therapy was recommended for the patient's ectropion.

Adult↗
PubMed1991

Immunohistochemical investigation of dermal capillaries in chronic venous insufficiency.

Skin biopsies from the area of the medial malleolus of 24 patients with chronic venous insufficiency, of 5 patients without signs or history of chronic venous insufficiency and of seven corpses without manifestation of chronic venous insufficiency, were sectioned and stained with hematoxylin and eosin and with Ki-67, a monoclonal antibody expressed in the nuclei of proliferating cells. Hematoxylin- and eosin-stained sections of all specimens were assessed blindly to determine the state of capillary increase in stasis dermatosis. Twenty-four patients were found to have different stages of stasis dermatosis. During the examination of the Ki-67 frozen sections, close attention was paid to the capillary bed of all sections for any Ki-67-positive nuclei in capillary cells. None of the three groups showed positive staining of nuclei in capillary cells. This finding proves that there is no capillary proliferation, but an elongation and distension of the capillaries.

Adult↗
PubMed1991

Immunohistochemical investigation of pericytes in chronic venous insufficiency.

Patients with chronic venous insufficiency show typical glomerulum like alterations of cutaneous capillaries. Objective of this study was to determine any changes of the alignment of pericytes around cutaneous capillaries in CVI patients. Skin biopsies from the area of the medial malleolus were taken from 42 patients with CVI, 5 healthy individuals and 11 cadavers without history of CVI. Sections were stained with HHF35, anti alpha and gamma muscle actin with the avidin-biotin-peroxidase method (ABC) and anti vimentin with the alkaline phosphatase anti-alkaline phosphatase technique (APAAP). The stage of stasis dermatosis was assessed and sections were examined for pericyte changes. Among the collective of 42 patients with CVI, 31 patients showed slight or severe pericyte changes, 11 patients were without changes. None of the sections from cadavers or healthy patients showed any pericyte changes. Pericytes are among other functions possibly involved in microvasculature regulation and wound healing. Thus destruction of the pericyte envelope might lead to microcirculatory dysfunction. This could be one of the causes that lead to leg ulcers in CVI.

Actins↗
PubMed1990

Pericapillary fibrin cuff: a histological sign of venous leg ulceration.

The incidence of pericapillary fibrin cuffs was investigated in 49 biopsies of venous leg ulcers and 67 biopsies of leg ulcers of non-venous etiology. Pericapillary fibrin cuffs were seen in 28 biopsies (57.1%) of venous leg ulcers, but only in 11 biopsies (16.4%) of non-venous leg ulcers. In the venous leg ulcers pericapillary fibrin cuffs occurred predominantly near the ulcer surface and around dilated capillaries. Dilation of the capillaries and inflammation probably contribute more to the pathogenesis of pericapillary fibrin cuffs than venous hypertension.

Capillaries↗
PubMed1990

[Cutaneous myofibroma--late manifestations].

Infantile myofibromatosis is a rare, but nevertheless well-known, entity that was first described in 1954 in Stout's classic article on juvenile fibromatosis. Usually the tumour mass is noted at birth or during the first weeks of life. Solitary lesions are at least twice as common as multiple lesions. A case of a 17-year-old woman with a tumour macroscopically resembling a basal cell epithelioma is presented. This tumour did not develop until the patient was 17 years old and cannot be distinguished histologically from an infantile myofibroma. Because of the very late appearance of this tumour the term "cutaneous myofibroma" is proposed for it. In young patients with a basal cell epithelioma-like lesion the diagnosis of cutaneous myofibroma has to be considered.

Adolescent↗
PubMed1989

[ACPA reaction in atypical Wegener's disease. Diagnostic test].

Clinical and biopsy findings in six patients (aged 29-64 years), suspected of having Wegener's granulomatosis, were not diagnostic. Cardinal signs were skin necroses, isolated deficits of cranial nerves, sudden amaurosis, renal failure with shunt sepsis and lung opacities suspicious of tumour. Only positive tests for anti-cytoplasmatic antibodies (ACPA) in serum made the diagnosis and led to appropriate treatment. This simple yet highly specific immunofluorescence test should be performed in every case of vasculitis of uncertain cause, even if typical clinical signs of Wegener's granulomatosis are at first absent.

Adult↗
PubMed1989

[Pulmonary changes in AIDS].

We reviewed retrospectively the clinical records of 28 patients with AIDS staged group IV according to CDC-criteria. Among these, 19 had pulmonary disease: most of them (n = 17) had pneumocystis carinii pneumonia (Pcp). 12/17 patients with proven Pcp displayed typical x-ray findings with diffuse perihilar interstitial infiltration sparing lung periphery. 3/17 had atypical features and 2 normal chest x-ray findings. These data are important to identify patients with pulmonary complications of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Intracavitary high-dose-rate-afterloading-radiotherapy in the esophagus of the pig].

The tolerance of sound esophageal mucosa to intracavitary high dose rate afterloading contact therapy with unique doses of 6 Gy and 12 Gy, respectively, was investigated in 15 pigs. Whereas no macroscopic or microscopic alterations of the mucosa are found after 6 Gy, a unique application of 12 Gy produces most severe side effects such as vascular occlusion due to fibrosis of the intima, formation of fistulas, and perforations of the esophagus wall. Future investigations will have to aim at the elaboration of schemes for dosage and fractionation.

Animals↗
PubMed1989

[Histopathologic changes in several opportunistic infections in AIDS].

Opportunistic infections are frequent in AIDS patients, particularly in the last phase of the disease, when they occur both singly and in combination with other conditions (for example KAPOSI's sarcoma). These opportunistic infections are the cause of death in over 90% of cases. Their incidence ist proof of cellular immunodeficiency. Based on our observations (17 cases at the two institutes since 1984) we present and discuss the histopathological changes of some important opportunistic infections (notably Pneumocystis carinii pneumonia, Mycobacteriosis (MAI), Cryptosporidium Cytomegalovirus and Toxoplasmosis gondii infection).

Acquired Immunodeficiency Syndrome↗
PubMed1988

Involvement of tumor necrosis factor in endotoxin-triggered neutrophil adherence to sinusoidal endothelial cells of mouse liver and its modulation in acute phase.

Tumor necrosis factor (TNF) has been shown to mediate lipopolysaccharide-induced neutrophil adhesion to liver sinusoidal endothelium in vivo. Female NMRI mice received either 5 micrograms lipopolysaccharide (R595) per animal alone (model A) or together with 116 mumol D-galactosamine (model B). One hour after injection, TNF activity in the serum was detectable to an equal extent in both models. Neutrophils in the liver, which had been identified by chloroacetate esterase staining of liver sections and quantitated by light microscopy, started to increase at 1 h and were elevated 10-fold above baseline at 6 h after application in (A) and (B). If 0.5 micrograms TNF instead of lipopolysaccharide was injected alone (model C) or together with D-galactosamine (model D), neutrophil influx into the liver was comparable to that observed in (A) or (B). Alanine aminotransferase activity in the serum was nearly normal in (A) and (C) 6 h after injection, while it reached levels up to 50-fold above baseline in models (B) and (D). This reflects the well-known D-galactosamine sensitization against lipopolysaccharide or TNF. Furthermore, degranulation of a large number of intrasinusoidal neutrophils could be observed 9 h after lipopolysaccharide-galactosamine injection. The administration of 116 mumol D-galactosamine per animal alone led neither to a measurable TNF activity in the serum nor to an increase in alanine aminotransferase activity or number of liver neutrophils. If the animals had received 50 microliter turpentine subcutaneously 24 h prior to lipopolysaccharide, TNF or D-galactosamine injection, the induced acute-phase reaction suppressed the increase of liver neutrophils in all models. Acute-phase reaction also prevented neutrophil degranulation and the rise of alanine aminotransferase in (B) to a great extent, while serum TNF activity was only minimally affected. It is concluded that TNF mediates neutrophil adhesion to the sinusoidal endothelium in vivo and that acute-phase reactants prevent lipopolysaccharide- or TNF-induced neutrophil influx into the liver.

Adjuvants, Immunologic↗
PubMed1988

[Castleman's lymphoma. Differential diagnosis of mediastinal tumors].

This report describes two cases of Castleman's disease (male 48 yrs, female 33 yrs). Two intrathoracic lymphomas were accidentally discovered during routine x-ray examination. Histologically, follicular hyperplasia, prominent interfollicular vascularity and sheets of mature plasma cells (intermediate variant) were seen. The etiology of this benign lymphoma remains unknown. Its significance lies in its differential diagnosis from malignant tumours.

Adult↗
PubMed1976

Bone formation by cancer metastases: case report and review of literature.

The formation of heterotopic bone tissue in malignant tumors or in their metastases is extremely rare. In a 60 years old male patient with bronchogenic carcinoma (adenocarcinoma) extensive bone formation was observed within multiple metastases in the skeletal muscles. On the basis of the microscopic findings, the mechanism of bone formation by malignant tumors is discussed. Obviously, proliferation of local mesenchymal tissue and differentiation of mesenchymal cells to osteoblasts is induced by the tumor cells.

Adenocarcinoma↗