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Biomedical subjects

H E Schaefer

Publications and source records attributed to H E Schaefer.

At least 73 records · Page 4Linked to original sources
PubMed1992

[The solitary pulmonary histoplasmoma].

A 63-year-old man who grows orchids as a hobby, fell ill with weakness and pain in his hips and legs 2 months after his latest trip to South America (Ecuador). The WBC count was 9900/microliters with unremarkable differential count while blood sedimentation rate was raised to 60/100 mm. The chest X-ray demonstrated in the right upper lobe a well-circumscribed coin lesion (3 cm diameter) of soft-tissue density, uncalcified and without cavitation. Computed tomography in addition revealed an enlarged lymph-node at the lower hilar pole, but no mediastinal lymphoma. Bronchoscopy demonstrated narrowing of a subsegmental ostium of the 6th segment on the right. An attempt at transbronchial biopsy failed. As a peripheral bronchial carcinoma was suspected, a posterolateral thoracotomy was performed (4 months after the trip to Ecuador). Rapid histological examination was negative for tumour and the lesion was therefore enucleated. Histologically (Grocott silver staining) a histoplasmoma was diagnosed. Several serum samples were positive for precipitating (M-band) and complement-binding antibodies (titre 12 days preoperatively was 1:16). The postoperative course was without complication. No anti-histoplasma antibodies were demonstrable 1 year postoperatively.

Antibodies, Fungal↗
PubMed1992

Primary thymic carcinoid with Cushing's syndrome.

In a 52-year-old Caucasian man osteopoikilosis had been misdiagnosed roentgenologically 2 years before his death. Gradually he developed Cushing's syndrome and ultimately superior vena caval obstruction. At autopsy a primary thymic carcinoid with extensive osteoblastic bone metastasis was found. Immunohistochemically the tumor was shown to be positive for adrenocorticotropic hormone (ACTH), cytokeratin (KL1), neuron-specific enolase, synaptophysin, chromogranin and glucagon. Remarkably the tumour was negative for serotonin despite high urinary hydroxyindolacetic acid levels. Bilateral hyperplasia of the adrenal cortex was found. The adenohypophysis showed a considerable reduction of ACTH-producing cells and numerous Crooke's cells with a characteristic immunohistochemical pattern.

Adrenal Cortex↗
PubMed1992

[Value of "non-specific" lymphoid infiltrates in bone marrow in high grade malignant peripheral non-Hodgkin's lymphomas].

We studied iliac crest biopsies of 120 patients with extramedullary high-grade Non-Hodgkin's lymphomas (NHL). The bone marrow of 69 patients contained foci of small lymphoid cells, which cytologically differed significantly from the extramedullary NHL and which we termed abnormal lymphoid infiltrates (ALI). The ALIs in 14 out of 25 cases immunohistochemically investigated in more detail were made up of small CD3+ cells optionally intermingled with a minority of CD20+ cells of small to intermediate size. In 10 patients, however, the ALIs satisfied the criteria of a low-grade NHL. In the vicinity of the extramedullary high-grade lymphoma, residues of the corresponding low-grade NHL were identified in up to 7 of 10 cases. We conclude that bone marrow ALIs associated with extramedullary high-grade NHL exhibit at least in part the criteria of a systemic clonal expansion of premalignant lymphoid cells or low-grade NHLs respectively, which gives rise to the final evolution of the extramedullary high-grade NHL.

Antigens, CD↗
PubMed1991

Histopathological studies on the local reactions induced by complete Freund's adjuvant (CFA), bacterial lipopolysaccharide (LPS), and synthetic lipopeptide (P3C) conjugates.

The inflammatory reactions following subcutaneous application of adjuvants revealed characteristic pathological patterns. The injection of complete Freund's adjuvant (CFA) resulted in the formation of large lipid deposits encircled by an inflammatory reaction and concentrically arranged collagen bundles. Bacterial lipopolysaccharide (LPS) caused granulomatous aggregations of mononuclear cells with thrombotic vessel occlusions. Inoculation of the lipopeptide adjuvants induced accumulation of mononuclear cells with only minimal fibrotic changes which were resolved after day 28. Lipopeptide conjugates based on the head group tripalmitoyl-S-glyceryl-cysteinyl-serin (P3CS) can thus be used as effective immunogens and adjuvants without long-term tissue damage.

Animals↗
PubMed1991

Comparison of host responses after intranasal infection of guinea-pigs with Mycoplasma genitalium or with Mycoplasma pneumoniae.

Guinea-pigs were infected intranasally with Mycoplasma genitalium or Mycoplasma pneumoniae. The lung lesions produced by the two mycoplasmas were comparable in extent and histological pattern. Sera of both animal groups taken 2 weeks after infection reacted strongly in the complement fixation test with the M. pneumoniae glycolipid extract. In an ELISA using the respective adherence proteins (P1-protein of M. pneumoniae and MgPa of M. genitalium), strong specific activity, but also considerable cross-reactions were found. Epitope analysis by using overlapping octapeptides of a P1-region immunologically active in human M. pneumoniae infections and of the corresponding MgPa-region revealed six common epitopes but also one M. genitalium and two M. pneumoniae specific determinants. For analysis of a possible pathogenicity of M. genitalium in the human respiratory tract species-specific tests have to be developed.

Administration, Intranasal↗
PubMed1991

[Tumors in immunodeficiency syndromes].

It is the purpose of this review to analyse prevalence and pathogenesis of tumours occurring in the diverse conditions of primary and secondary immunodeficiencies. In general, most states of immunodeficiences are connected with a highly increased tumour risk. However, there is circumstantial evidence that immunodeficiency-related malignancies do not primarily result from an impaired immunosurveillance. With special regard to ataxia-telangiectasia it has been found that congenital chromosomal instability deregulates the maturation of immunocompetent lymphoid cells by interfering with their natural DNA rearrangements and eventually leads to false recombinatory events with oncogenetic consequences in a parallel way. Malignancies in primary common variable or in secondary (e.g. AIDS) immunodeficiency may result from an impaired immunity to oncogenic viruses or from chronic immune damage due to secondary autoimmune disorders.

Acquired Immunodeficiency Syndrome↗
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

The occurrence of beta-glucuronidase in erythrocyte inclusions.

This study presents erythrocytic inclusion bodies exhibiting histochemically a strong beta-glucuronidase activity. The unique occurrence of this enzyme in cells of the erythropoietic series has never been described before and characterizes a novel type of erythrocyte inclusions mainly observed in patients suffering from liver damage but also from myelodysplasia and congenital dyserythropoietic anemia type I. Since it is known that hepatocytes contain high activities of beta-glucuronidase, we supposed a relationship between an increased breakdown of liver cells and the appearance of beta-glucuronidase positive inclusions in the red cells. To prove this hypothesis, we determined the beta-glucuronidase plasma levels of 99 unselected patients suffering from various liver disorders in comparison with 19 healthy controls by use of the umbelliferone technique. Our results indicate that in cases with liver diseases beta-glucuronidase plasma levels are significantly increased as compared with normal persons. The availability of a sufficient amount of beta-glucuronidase, thus, seems to be one prerequisite for the appearance of these inclusions in erythrocytes. As demonstrated by our investigations on congenital dyserythropoietic anemia, in which the red cells also show beta-glucuronidase positive inclusions, another premise seems to be an elevated autophagolysosomal activity in the erythrocytes.

Adult↗
PubMed1989

[Hypophosphatemic osteomalacia in adults].

Hypophosphataemic osteomalacia occurred in a 38-year-old woman. The leading clinical symptom was severe bone pain. X-ray studies demonstrated fractures of the iliac crest and pubic and ischiadic bone, as well as Looser's zones and demineralization of the skeleton. Computerized densitometry of the bone revealed a 31% reduction of hydroxyapatite. Histological evaluation showed nearly absence of osteoclasts and extensive demineralisation of the bone. Hypophosphataemia (0.48 mmol/l), increased urinary phosphate clearance (36 ml/min), reduced renal-tubular reabsorption for phosphate (73%) and increased alkaline phosphatase (355 U/l) were present. Parathyroid hormone and 1,25-dihydroxyvitamin D were normal. No inborn errors, disturbances of the calcium metabolism or paraneoplastic signs could be detected. Defective renal tubular reabsorption of phosphate is likely to be the underlying cause of the disease. Phosphate supplementation and intermittent vitamin D administration remains the therapy of choice.

Adult↗
PubMed1989

Smokers' dysmyelopoiesis--bone marrow alterations associated with cigarette smoking.

Cigarette smoking is frequently associated with leukocytosis (with normal differential count) and polyglobulia in the peripheral blood. Corresponding studies on bone marrow alterations in smokers have not been done until now. We therefore investigated bone marrow trephine biopsies of 32 smoking persons. Biopsies had been mainly performed because of mild peripheral leukocytosis. In all cases we found a moderate increase in granulopoietic cells with a significant shift to the right and a distinct stimulation of phagocytic activity in macrophages. According to cytochemical findings, neutrophils are the major target of this phagocytic activity. We interpret these results as a smoking induced inhibition of locomotion in segmented neutrophils leading to an accumulation of mature polymorphs in the bone marrow with consecutive break-down and phagocytosis of senescent cells. We propose the designation "smokers' dysmyelopoiesis" for these changes.

Adult↗
PubMed1989

Investigations on beta-glucuronidase-positive erythrocytic inclusions.

Novel erythrocytic inclusion bodies, characterized by strong beta-glucuronidase activity, are described. Their physicochemical properties differ substantially from those of known inclusion bodies and they are mainly observed in patients with liver damage. Since these inclusions occur almost exclusively in erythrocytes, the intraerythrocytic beta-glucuronidase must originate from an extraerythrocytic source, perhaps entering erythrocytes via a receptor-mediated endocytotic pathway.

Adult↗
PubMed1988

Beta-glucuronidase and chloroacetate-esterase staining discriminates rat liver sinusoidal endothelial cells from Kupffer cells in primary culture.

Beta-glucuronidase and N-AS-D-chloroacetate esterase cytochemistry have been applied to rat liver sinusoidal endothelial cells and Kupffer cells. Both staining procedures allowed a clear-cut differentiation of either cell type. Kupffer cells which had been stained with beta-glucuronidase showed a positive reaction, whereas sinusoidal endothelial cells were completely negative. If the chloroacetate reaction was used, the former stained diffusely while the latter showed a characteristic granular staining pattern. Identity and purity of sinusoidal endothelial cells and Kupffer cells was validated by transmission and scanning electron microscopy as well as by the pattern of released eicosanoids which is characteristic for either cell type. These two staining techniques are a valuable addition to the peroxidase reaction commonly applied for differentiation.

Animals↗