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Biomedical subjects

A Nerlich

Publications and source records attributed to A Nerlich.

At least 109 records · Page 6Linked to original sources
PubMed1992

Hyperplastic callus formation in osteogenesis imperfecta.

Osteogenesis imperfecta, an inherited disorder of connective tissues, affects roughly (OI) 4000 people in Germany (11). The main clinical symptoms are fragile bones, progressing skeletal deformities, generalized osteoporosis and short stature. Incidentally, the clinical manifestations can range from perinatal lethal forms to phenotypical normal adults. In many instances the underlying causes of the disease are mutations in gene coding for collagen I, the predominant protein in most connective tissues. Fracture healing is usually not impaired, although in a unique group of OI-patients, a tumor-like hyperplastic callus occurs with excessive deposition of extracellular matrix constituents. Biochemical analysis of the callus is reminiscent of bone from early stages of human development and normal fracture healing (e.g. collagen type composition, degree of posttranslational modification). This underlines that, besides collagen mutations, the regulation of collagen synthesis and their posttranslational processing might be disturbed in patients with hyperplastic callus formation.

Bony Callus↗
PubMed1992

Rotational angioplasty and directional atherectomy to treat complex lesions of the right coronary artery.

A combination of interventional devices including the Rotablator and directional coronary atherectomy (DCA) was used to treat a 39-year-old patient with a complex lesion of the right coronary artery. The devices enabled the recanalization and reconstruction of the diseased vessel without laceration or dissection, leaving a smooth-edged segment. The histological analysis of the tissue obtained from DCA revealed no predictors of restenosis, like highly cellular material or media. Thus, combination of mechanical interventional devices allowed to treat a highly complex lesion without lacerating the vessel and leaving an excellent acute and long-term outcome.

Adult↗
PubMed1992

Collagen type II in Langer-Saldino achondrogenesis: absence of major abnormalities in a less severe case.

Collagen extracted either from cartilage or synthesized in vitro was analyzed to identify possible molecular defects in the cartilaginous matrix of a male fetus suffering from a mild form of type II achondrogenesis (Langer-Saldino). The tissue architecture of the patient's cartilage was markedly altered and showed numerous fibrous vascular canals which were focally stained by antibodies against collagens I and III. Collagen II was present, although heterogenously distributed throughout the cartilaginous matrix. Upon electrophoretic separation, however, the patient's femoral head cartilage showed the presence of collagens II, IX and XI only, which was similar to an age-matched control. The hydroxyproline/hydroxylysine ratio of collagen II of the patient was not significantly different from that of the control. Likewise, the compositions of collagens synthesized by cultured chondrocytes as well as fibroblasts were similar in the patient and the control. The results provide strong evidence that, in the present mild case of Langer-Saldino achondrogenesis, collagen II is expressed and regularly hydroxylated at its lysyl residues. This may indicate that cartilage components other than collagen II may be responsible for the altered tissue organization observed. Along with previous observations, our data suggest that the degree of biochemical matrix alterations may be related to the severity of the clinical phenotype.

Achondroplasia↗
PubMed1991

Human acardiac anomaly: a report of three cases.

We report on three cases of acardia, all of which had to be classified as acardius anceps. The degree of cardiac malformation ranged between a completely missing heart and a malrotation of a relatively well-developed heart. One fetus showed an intermediate form of cardiac malformation with a hypoplastic cor triloculare. Our findings suggest that the defect in cardiac development may take place at different times in early embryogenesis, resulting in differing degrees of cardiac malformation.

Abnormalities, Multiple↗
PubMed1991

Distribution of basement membrane-associated heparan sulfate proteoglycan in idiopathic and AIDS-associated Kaposi's sarcoma.

In the present study we analyzed the immunohistochemical distribution of different major basement membrane (BM) components with special emphasis on the BM-associated heparan sulfate proteoglycan (HSPG) in early and late stages of Kaposi's sarcoma (KS), both of idiopathic and AIDS-associated origin. In early KS all BM components tested were found surrounding the small clefts of tumour vessels. Heparan sulfate proteoglycan showed the weakest and often fragmented pattern of staining. In the late, nodular sarcomatous form of KS individual tumour cells were surrounded by a BM composed of collagen IV, laminin and fibronectin, while heparan sulfate proteoglycan was not detectable in most cases. Neither between idiopathic and AIDS-associated KS nor between cutaneous and visceral lesions were significant differences in the staining pattern. Our findings of a rather selective expression of various BM-components and the known distribution in normal blood and lymphatic capillaries raises the hypothesis that KS-cells may be derived from cells of lymphaticovenous differentiation.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Clinical findings in middle lobe syndrome and other processes of pulmonary shrinkage in children (atelectasis syndrome).

Processes of atelectasis and pulmonary shrinkage are not confined to the right middle lobe. This fact is illustrated by case reports of five of our nine such patients. All cases shared common clinical and morphologic similarities: congenital malformations of the bronchial skeleton, compression, and chronic inflammation produce comparable pulmonary morphology that always includes atelectasis. Atelectasic processes of longer duration require surgical resection; this led to cures in all the authors' patients.

Bronchiectasis↗
PubMed1991

Parvovirus B19 infection of the fetus. Histology and in situ hybridization.

Fetal tissues from 16 spontaneous abortions, two terminations, and one perinatal death, 18 of which were associated with maternal human parvovirus B19 infection, were examined for B19 infection by histology and in situ hybridization using a digoxigenin-labeled B19-DNA probe. In 15 spontaneous abortions and one termination, erythroblasts with intranuclear inclusions (lantern cells) reacted with B19-DNA by in situ hybridization. No internal or external fetal malformations were observed. Because 13 (86.7%) spontaneous abortions with lantern cells occurred between the 20th and 28th weeks of gestation, it is postulated that B19 infection may be a particular threat to the fetus during this stage of gestation.

Adult↗
PubMed1991

Differential basement membrane composition in multiple epithelioid haemangioendotheliomas of liver and lung.

We report a case of epithelioid haemangioendothelioma involving both lung and liver. The tumour cells were positive for factor-VIII-related antigen. Immunohistochemical analysis of various basement membrane components in tumour tissue of lung and liver showed striking differences. In the liver tumour there was selective expression of collagen IV, with minimal and focal amounts of laminin and basement membrane-associated heparan sulphate proteoglycan. In the lung tumour nodules, in contrast, all these basement membrane components were present. These patterns of basement membrane expression closely resemble those of normal liver and lung basement membrane respectively. We suggest that this provides evidence that epithelioid haemangioendothelioma arises from local endothelial cell proliferation and that it supports the assumption of a multicentric rather than metastatic origin when multiple tumour deposits are found.

Aged↗
PubMed1991

Coronary directional atherectomy: rescue for failed balloon angioplasty and treatment of complicated lesions.

Balloon angioplasty of the coronaries is still limited by the problems of acute complication and restenosis. Percutaneous directional atherectomy was conceived as a method to remove obstructive material from within the vessel. After encouraging results were obtained in peripheral vessels, coronary atherectomy has been selectively performed in 25 patients with lesions either not well suited for PTCA [n = 11], or as a bail-out after resistant [n = 2] or failed PTCA [n = 12]. Twenty-one LAD lesions [4 ostial, 13 proximal, 2 mid, and 2 bifurcation] and four right coronary artery [RCA] lesions with a mean length of 9 +/- 6 mm (19 eccentric, and 6 concentric) could be effectively reduced from 90% +/- 12% to 18% +/- 22%. Seventy-five percent of rescue cases could be spared emergency bypass operation. At 6 months, angiographic restenosis has been documented in 3 out of 11 patients studied to date (27%). Histologically, rescue procedures resulted in the removal of obstructing plaque material and only minimal thrombus. The occurrence of two perforations during rescue procedures, although clinically insignificant, emphasizes the need for judicious excision. In summary, directional atherectomy appears to be useful to treat lesions not well suited for PTCA, and important as a bail-out method after failed PTCA.

Adult↗
PubMed1991

[Current status of directional coronary atherectomy in interventional cardiology].

Directional coronary atherectomy (DCA) was used in 74 patients with an average age of 56 years. They were categorized into three different groups depending on the indications for atherectomy. Group I included all patients who had atherectomy as their primary intervention (n = 26), because they were assumed to be unsuitable for PTCA. Group II consisted of patients in whom DCA was used after failed balloon dilatation with unsuccessful but uneventful treatment (n = 20). Group III (n = 28) included cases where DCA was performed as a "rescue" or "bail-out" procedure after failed PTCA resulted in critical ischemia (ECG changes, chest pain, hypotension, and shock). The target lesions were located in LM 2, LAD 52, RCA 16, ACVB 4. The mean length of lesion was 8 mm (2-25 mm). The overall success rate was 94%. The mean stenosis was reduced from 90.6 +/- 10% to 17.2 +/- 14.8% in cases with primary success. The presently available follow-up angiography (n = 31) showed six restenoses. Major complications occurred in seven cases (death: 0, myocardial infarction: 2, CABG within 24 h: 5). Histological analysis revealed highly cellular areal as a major characteristics of a coronary lesion and also of restenotic tissue. Tissue of the lamina elastica was present in 44% and of media in 14%. Thrombus was found only rarely. Ultrastructure showed a significant amount of extracellular matrix in the primary coronary lesions and isolated smooth muscle cells without gap-junctions. RER, mitochondria were typical for the synthesizing type of smooth muscle cell. In restenotic tissue a focal high density of smooth muscle cells with increased synthesizing activity and gap-junctions was present. Endothelial cells (and macrophages) were found only rarely. Furthermore, altered smooth muscle cells from restenotic tissue showed a significantly increased migration and proliferation. Our results show that DCA is a safe and effective technique that can extend the use of percutaneous procedures and provide a promising, nonsurgical option in cases of failed PTCA. Histological analysis revealed a proliferative process as a characteristics of restenosis development.

Angioplasty, Balloon, Coronary↗
PubMed1991

Immunohistochemical localization of extracellular matrix components in human diabetic glomerular lesions.

The immunohistochemical localization of the extracellular matrix was examined in 31 cases with different degrees of human diabetic nephropathy using antisera to human collagen types I, III, IV, V, fibronectin, laminin, and basement-membrane-associated heparan sulfate proteoglycan (HSPG). In normal glomeruli, HSPG was predominantly localized in the glomerular basement membrane and in the mesangium, and to minor extent in the basement membranes of tubules and Bowman's capsule. Collagen IV and laminin were distributed in glomerular basement membrane and mesangium in minor amounts. Interstitial collagens usually do not occur within glomeruli except for collagen V which has a light microscopic glomerular distribution similar to collagen IV. In diabetic diffuse glomerulosclerosis, the enlarged mesangial matrix showed an increased staining reaction for collagen IV, V, laminin, and fibronectin whereas the staining pattern of HSPG was markedly reduced. Early, small nodular lesions in diabetic glomeruli were similarly positive for most of the basement membrane components, whereas HSPG remained absent. With an increase in the diameter of the noduli, however, the staining reaction for all basement membrane components diminished, whereas interstitial collagens V and III, but not collagen I, were present in these noduli in substantial amounts. These initial studies provide evidence that the changes in the glomerular matrix in diabetic nephropathy may be divided into distinct and progressing stages of lesions. The reduced amount of HSPG even in slight, early lesions may represent the morphologic correlate to the impaired filter function of the glomerular basement membrane.

Adult↗
PubMed1990

Percutaneous peripheral atherectomy: angiographic and clinical follow-up of 60 patients.

The Simpson atherectomy catheter was used to treat 60 patients with a total of 94 lesions comprising 63 stenoses (mean length 1.1 +/- 0.5 cm) and 31 occlusions (4.2 +/- 2.9 cm) of the superficial femoral (n = 77), popliteal (n = 8), iliac (n = 8) and anterior tibial (n = 1) arteries. The immediate angiographic success rate was 90% for both occlusions and stenoses, and clinical success was obtained in 82% of patients. The stenoses were reduced from 83 +/- 13% to 17 +/- 18% acutely and to 31 +/- 26% at 6 months; the occlusions were reduced from 100% to 9 +/- 9% initially and to 60 +/- 34% at 6 months. Angiographic restenosis was found in 24% of lesions: 23% in concentric and 11% in eccentric lesions and 47% in total occlusions. At 1 year, 72% of patients had clinically patent arteries with maintained Doppler index and walking distance. Three of four patients undergoing repeat atherectomy had a second restenosis. In summary, the procedure was found to be safe and effective in the treatment of peripheral vascular disease. It appears to be particularly beneficial in the treatment of eccentric stenoses and is not limited by the presence of calcification.

Aged↗
PubMed1990

Primary leiomyosarcoma of the truncus pulmonalis. Report of a case with typical features and unusual metastases.

We present the fatal case of a patient with a primary leiomyosarcoma of the pulmonary trunk. During the patient's clinical course of 2 months, the pulmonary valve and the proximal segment of the truncus pulmonalis had to be removed surgically. At autopsy, we found an extensive local tumour recurrence with an almost complete obliteration of the right ventricular outflow. The right pulmonary artery was subtotally obliterated by a tumour thrombus, and the lungs and both adrenal glands showed extensive tumour metastases. A solitary tumour metastasis within the lumen of the right vena iliaca communis obviously was associated with diagnostic manipulations in the course of heart catheterization.

Blood Vessel Prosthesis↗
PubMed1990

Altered collagen metabolism in osteogenesis imperfecta fibroblasts: a study on 33 patients with diverse forms.

The pattern of collagen metabolism was analysed in fibroblast cultures from patients with diverse forms of osteogenesis imperfecta (OI). Generally, OI fibroblasts show an insufficient collagen synthesis which is most obvious in patients between 2 and 9 years of age during which period control fibroblasts have an elevated collagen synthesis. OI fibroblasts remain on a basal level except for fibroblasts from OI type IV patients which seem to approach normal levels. In addition, OI fibroblasts generally show a slightly increased degradation of newly synthesized collagen which again is most obvious between 2 and 9 years. These differences in collagen degradation, however, only contribute to a minor extent to the lack of net collagen synthesis during early childhood. No correlation could be found between the degree of overmodification of collagen and its degradation since fibroblasts of both OI type I and OI type II have an elevated degradation though only the latter ones produce overmodified collagen molecules. Pulse labelling of collagen with radioactivity labelled sugars was used to distinguish between normal collagen chains or CNBr-derived peptides and those which were overmodified. In all three cases studied (OI II, OI III, OI IV) the entire triple helical domain of alpha 1(I) and alpha 2(I) was overglycosylated. The amount of overmodification, however, was not uniform but rather unique for each patient studied. We assume that the molecular defects in the majority of OI cases may be located in the mechanisms operating on the control of both the age appropriate synthesis of collagen and its degree of post-translational modification.

Cells, Cultured↗