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Biomedical subjects

H C Bauer

Publications and source records attributed to H C Bauer.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cytological diagnosis of bone tumours.

We evaluated the diagnostic accuracy of fine-needle aspiration biopsy in a prospective study of 300 patients with previously undiagnosed bone lesions. Patients with suspected local recurrence of a primary bone tumour or a metastatic lesion of a previously diagnosed malignancy were excluded. Fine-needle aspiration biopsy was performed under radiological control as an outpatient procedure. The series was grouped into three major categories: 1) benign bone lesions including infections; 2) primary malignant bone tumours; and 3) metastases including lymphomas and myelomas. We compared the cytological diagnosis with the final diagnosis as assessed by histological examination and/or the clinical and radiological features. Material considered conclusive for cytological diagnosis was obtained from 251 of the 300 patients. Of the 49 failures, there were 24 aspirates with insufficient cellular yield and 25 in which a diagnosis could not be made although the cytological material was adequate in quantity. Most of the inconclusive aspirates (36/49) were obtained from benign bone lesions. The diagnosis was correct in 239 (95%) of the 251 cases providing adequate cytological material. There were eight (3%) falsely benign diagnoses, one (0.3%) falsely malignant, and three cases in which we were unable to differentiate between sarcoma and a metastasis. Chondrosarcoma (2/12) gave the greatest diagnostic difficulty and Ewing's sarcoma the least (0/9). There were no decisive errors of treatment. All falsely benign or malignant diagnoses were questioned, and led to open biopsy since they did not correlate with the clinical and radiological features. Our study suggests that fine-needle aspiration biopsy is a valid option for the diagnosis of bone tumours. It is a simple outpatient procedure which gives sufficient cytological material for the correct diagnosis in 80% of cases. As with histological analysis of material from open biopsy, the cytological assessment must agree with the clinical and radiological findings.

Adolescent↗
PubMed1995

Sequence of the porcine full-length cDNA encoding ribosomal protein rpS12.

The full-length cDNA encoding the porcine ribosomal protein rpS12 was shown to be differentially expressed in endothelial and smooth muscle cells. A cDNA clone containing the entire rpS12 sequence was isolated from growth-stimulated capillary endothelial cells by use of subtractive hybridization and differential screening. The porcine rpS12 cDNA coding region exhibits 94% identity to the rat rpS12 and 92% to the human rpS12 cDNAs.

Amino Acid Sequence↗
PubMed1995

Ontogenic expression of the erythroid-type glucose transporter (Glut 1) in the telencephalon of the mouse: correlation to the tightening of the blood-brain barrier.

Since Glut 1 was shown to be highly abundant in brain microvessels, its distribution during early developmental stages seems of importance in respect to the timing of blood-brain barrier (bbb) formation in the developing CNS. Here we have followed the temporal expression of the erythroid-type glucose transporter Glut 1 in the telencephalon of the embryonic and newborn mouse, beginning at the 9th intrauterine day. Glut 1 immunofluorescence staining was done on cryosections using a rabbit polyclonal antiserum to purified human erythrocyte glucose transporter. Endothelial cells resp. capillaries were detected by staining with a rhodamin-coupled Bandeiraea simplicifolia lectin (BSL). In parallel, the developmental tightening of the embryonic bbb was assessed by perfusion of mouse embryos with Trypan blue and horse radish-peroxidase. At E9, prior to the onset of intraneural neovascularization, strong Glut 1 immunoreactivity was found in the whole neuroectoderm but only minor staining was seen in the perineural domain. Glut 1 expression remained uniformly distributed in the intraneural tissue at E10, the beginning of intraneural neovascularization in the mouse. From E11 onwards, Glut 1 immunoreactivity was invisible in neuroepithelial cells, but appeared tightly associated with intraneural capillaries. Perfusion of E12 embryos using trypan blue solution and HRP revealed that most parts of the CNS and spinal cord were impermeable to the tracer substances at that stage. Thus, we suggest that the bbb is established very early in CNS development, probably in the course of intraneural neovascularization. In addition, our data indicate that the restriction of Glut 1 expression to the intraneural capillaries reflects the onset of bbb function in the mouse embryo.

Animals↗
PubMed1995

Heterogeneity of smooth muscle-associated proteins in mammalian brain microvasculature.

In the brain, the microvascular system is composed of endothelial cells surrounded by a layer of pericytes. The lack of smooth muscle cells in this tissue suggests that any contractile function must be performed by one or both of these cell types. The present study was undertaken in order to identify cells in terminal blood vessels that contain smooth muscle-like contractile machinery. Endothelial cells were reactive with antibodies against smooth muscle myosin but showed no other smooth muscle-related features. In contrast, pericytes of intact microvessels showed a pattern of protein expression similar to that of smooth muscle cells. Pericytes also behaved in tissue culture like cultured smooth muscle cells, with regard to the changes in expression of smooth muscle-related proteins. These data confirm the close relationship between smooth muscle cells and pericytes, and point to their contractile function in the brain microvessels.

Animals↗
PubMed1995

Near-haploidy in two malignant fibrous histiocytomas.

Cytogenetic analysis of two malignant fibrous histiocytomas (MFH) revealed near-haploid clones in both tumors. One tumor had only 23 chromosomes, the lowest chromosome number so far detected in human neoplasia, and showed several structural rearrangements: 23, X, der(1)t(1;?;8)(q42;?;q13), +del(7)(p11),der(8)t(8;13)(q13;q12), inv(9)(p24q21), r(10)(p15q26), -13, der(14)t(14;22)(p13;q11), -15, +r. The other MFH had only numerical changes: 28,X, +5, +18, +20, +21, +22/56, idemx2. With the present two cases, four of 78 MFHs studied in our laboratory have been near-haploid, suggesting that this otherwise rare phenomenon in neoplasia may be relatively common in MFH.

Female↗
PubMed1995

Long-term adjuvant interferon treatment of human osteosarcoma. A pilot study.

During the period from 1971 to 1990 all osteosarcoma patients referred to the Karolinska Hospital without signs of metastases received human leukocyte interferon (IFN) as adjuvant treatment. Patients referred between 1985 and 1990 were given more intensive human leukocyte IFN treatment, i.e. a standard dose of 3 MU s.c. daily for 3-5 years. These 19 patients, all followed for 5 years, were included in a pilot study which entailed patients with central localization where radical surgery was not feasible. Metastases developed in 9 patients, of whom 3 had local recurrences. Sixty-three percent are free of disease at 5 years. Side-effects were negligible and long-term toxicity practically non-existent. It is suggested that a randomized multicenter IFN trial should be instituted on patients with poor prognosis receiving chemotherapy and/or that IFN treatment should be combined with other therapeutic modalities--irradiation, chemotherapy or anti-angiogenic substances--in osteosarcoma.

Bone Neoplasms↗
PubMed1995

Survival after surgery for spinal and extremity metastases. Prognostication in 241 patients.

We assessed the survival after surgery in 153 patients with extremity metastases and 88 with spinal metastases. The survival rate for the whole series of 241 patients was 0.30 at 1 year, 0.15 at 2, and 0.08 at 3 years. The 1-year survival rate was the same for the extremity metastases group and the spinal group. Univariate analysis showed that 1-year survival was related to metastatic load, site of primary tumor, and presence of pathologic fracture. Multivariate regression analysis showed that pathologic fracture, visceral or brain metastases, and lung cancer were negative prognostic variables. Solitary skeletal metastases, breast and kidney cancer, myeloma, and lymphoma were positive variables. A prognostication model based on these variables stratified the patients into 3 groups with a 1-year survival ranging from 0.5 to 0.0. These prognostic variables can be used for differentiating the treatment of cancer patients with pathologic fracture or epidural compression.

Adult↗
PubMed1995

Low risk of recurrence of enchondroma and low-grade chondrosarcoma in extremities. 80 patients followed for 2-25 years.

We analyzed the clinical course in 40 patients with enchondroma and 40 with low-grade chondrosarcoma of the extremities after a median follow-up of 7 years. 13 patients with enchondroma and 2 with chondrosarcoma had only open biopsy and they had no signs of further progression of the lesions. Among 23 patients with enchondroma and 23 with chondrosarcoma who were treated by intralesional curettage, 3 had local recurrences. The 10-year local recurrence rate was 0.04 in the enchondroma group and 0.09 in the chondrosarcoma group. There were no metastases. The results imply that enchondroma and low-grade chondrosarcoma of the extremities should be treated with limited surgery. The morbidity associated with en bloc resection and reconstruction can apparently be obviated without jeopardizing the limb or survival.

Adolescent↗
PubMed1995

Giant-cell tumours with fracture at diagnosis. Curettage and acrylic cementing in ten cases.

Between 1971 and 1991 we treated 98 patients with giant-cell tumours, 15 of whom presented with a pathological fracture. They were most common around the knee (12). Nine fractures were intra-articular. The tumours were treated by curettage and acrylic cementing (10), excision and endoprosthesis (1), excision and allograft (1), curettage and autologous graft (2) or by resection of the fibular head (1). Four patients had local recurrence, three of whom were cured by repeat curettage and cementing. Pathological fracture through a giant-cell tumour is not a contraindication to treatment by curettage and acrylic cementing.

Adolescent↗
PubMed1994

Local recurrence of soft tissue sarcoma a risk factor for late metastases. 379 patients followed for 0.5-20 years.

We performed a retrospective analysis of 379 adult patients treated for soft tissue sarcoma. None had metastasis at the time of diagnosis and all were treated surgically. Patients who developed metastatic disease before the local recurrence were excluded. The 8-year metastasis-free survival rate in the group of 261 patients with local tumor control was 0.72, compared to 0.67 in the 118 patients with local recurrence (P 0.2). Multiple regression analysis showed that high-grade malignancy and large tumor size were risk factors for metastases. Local recurrence was not a risk factor. However, when patients with small and/or low-grade tumors were analyzed separately, local recurrence emerged as a risk factor. In this group of patients, the 8-year survival rate was 0.87 for those with local control and 0.64 for those with local recurrence (P 0.004). Local recurrence appears to be a risk factor for the development of late metastases in patients who otherwise have a low risk of metastases.

Adolescent↗
PubMed1994

Diluted and undiluted Mercox severely destroy unfixed endothelial cells. A light and electron microscopic study using cultured endothelial cells and tadpole tail fin vessels.

Mercox is a methylmethacrylate-based resin which is widely used for vascular corrosion casting with subsequent scanning electron microscopic analysis. In the present study the effect of undiluted and diluted Mercox (4 + 1; volume + volume; Mercox: monomeric methyl-methacrylate (MMA); 0.02 g catalyst MA/ml Mercox) and methyl-methacrylate with and without catalyst MA (0.625 g/10 ml MMA) on fixed and unfixed endothelial cells was studied. Light microscopy (LM) of cultured capillary endothelial cells (ECs), which were replicated with diluted or undiluted Mercox shows degranulation and membrane perturbation of ECs, while no morphological changes occur in glutaraldehyde-prefixed ECs. Scanning electron microscopy (SEM) of replicas (= resin blocks) polymerized on prefixed ECs reveals unchanged ECs and replicas show many details. Unfixed ECs are destroyed and replicas reveal aberrant features. Transmission electron microscopy (TEM) of prefixed and unfixed ECs (cultured endothelial cells, endothelial cells of perfusion prefixed and of unfixed tadpole tail fin vessels) substantiates LM and SEM findings. Prefixed ECs resist Mercox without fine structural changes, while unfixed cells undergo destruction. It is recommended to fix vessels prior to casting. Extravasations in micro-vessels are considered to be caused by focal chemical destruction of endothelial cells.

Animals↗
PubMed1994

MR imaging of benign peripheral nerve sheath tumors.

In a retrospective, nonblind review of MR imaging of 15 benign peripheral nerve neoplasms in 13 patients, the signal pattern of the tumors (including contrast-enhanced images) and stage were assessed. One lesion was subcutaneous, 9 intramuscular, 2 intermuscular and 3 extracompartmental. One lesion was located to the trunk, 5 to the upper extremity and 9 to the lower. The signal on T1-weighted spin-echo images was homogeneous isointense compared to adjacent muscle in 11 lesions and in 2 slightly hyper- and in 2 slightly hypointense. T2-weighted spin-echo images, acquired in all but one examination, showed a hyperintense signal, homogeneous in 8 and centrally inhomogeneous in 6 lesions. Postcontrast T1-weighted images of 11 lesions showed a strong signal, with an inhomogeneous enhancement in the center of the lesion similar to that obtained in T2-weighted images. In 2 cases there were signal characteristics indicating bleeding in the tumor. In one lesion both the nonenhanced and contrast-enhanced T1-weighted images showed a hypointense signal in the tumor center suggestive of intramuscular myxoma. All lesions were well delineated without reactive edema. In all cases, anatomic tumor location was correctly assessed. Although the findings were not pathognomonic for neurinoma, MR imaging provided valuable information confirming the clinical and cytologic assessments.

Adult↗
PubMed1993

Neovascularization and the appearance of morphological characteristics of the blood-brain barrier in the embryonic mouse central nervous system.

Vascularization and expression of blood-brain barrier (bbb)-associated morphological characteristics during the embryonic development of the mouse central nervous system (CNS) was studied by ultrastructural analysis. At embryonic day 9 (E9) capillaries were only found in the perineural mesenchymal tissue. These capillaries showed fenestrations, and pericyte like cells (PC) were found joined to the vessel walls. Around E10 endothelial cells (EC) together with PC started invading the intraneural section. At this stage, the immigrating endothelial cells lost their fenestrations and exhibited numerous, partly extended junctional complexes, which appeared 'tight' in some places. A first intraneural anastomotic plexus was observed at E10, as evidenced by the presence of blood cells in all capillary lumens. While the number of junctional complexes remained constant in intraneural capillaries, the frequency of pinocytotic vesicles decreased significantly from E10 to E17. These findings indicate that from the first day of intraneural vascularization onwards, the morphological properties of the bbb are present in the early embryonic mouse cerebral cortex.

Animals↗
PubMed1993

Cytogenetic findings in 33 osteosarcomas.

Thirty-three osteosarcomas (OS) were analyzed cytogenetically. Clonal chromosome changes were detected in 17 cases. Six tumors had chromosome numbers in the diploid range, 6 in the triploid range, 1 in the tetraploid range and 1 in the pentaploid range, while 3 tumors had multiple clones with different ploidy levels. Including the present 17 tumors, a total of 27 OS with clonal aberrations have been reported. The recognizable structural rearrangements in these 27 tumors clustered to chromosome arms 1p, 1q, 3p, 3q, 7q, 11p, 17p and 22q. Chromosome bands 1q11, 1q21, 1q42 and 7q11 were the most frequently rearranged, and the most common numerical rearrangements were -3, -10, -13 and -15. Supernumerary ring chromosomes, in 2 tumors as the sole change, were found in all 3 parosteal OS, which is in agreement with the findings in 1 previously reported parosteal OS. The association between ring formation and parosteal morphology represents the first cytogenetic-morphologic entity among OS.

Adolescent↗
PubMed1993

Aberrations of chromosome segment 12q13-15 characterize a subgroup of hemangiopericytomas.

BACKGROUND: In later years, several characteristic acquired chromosomal aberrations have been identified in mesenchymal tumors. Many of these aberrations, either alone or with histopathologic and clinical data, are useful in diagnosis. The cytogenetic profile of hemangiopericytomas has been poorly investigated. METHODS: Short-term cultures from four spindle cell tumors were cytogenetically analyzed. RESULTS: Clonal acquired chromosome aberrations were found in three of the four tumors: inv(12) (q14q24) in a malignant hemangiopericytoma, a supernumerary der(3)t(3;12) (p21-23;q13-15) in a benign hemangiopericytoma, and t(6;12;19) (p21;q13;p13) in a spindle cell sarcoma that was histologically a malignant hemangiopericytoma or a synovial sarcoma. The fourth tumor, a malignant hemangiopericytoma, had a normal karyotype. The tumors with inv(12) and t(6;12;19) had subclones with trisomy 5 in addition to the structural changes. CONCLUSIONS: The current findings and the literature data indicate that a subgroup of hemangiopericytomas is characterized by rearrangement of chromosome segment 12q13-15.

Adult↗
PubMed1993

Adjuvant interferon treatment in human osteosarcoma.

An update of the adjuvant trial on osteosarcoma in Sweden comparing patients receiving natural interferon (IFN) alpha with a high-dose chemotherapy group and a nonadjuvant group is presented. The overall survival for the IFN group is 49%, for the chemotherapy group 54%, and for the nonadjuvant group 35%. Trial evaluation was complicated by group differences with respect to various clinicopathologic features of prognostic significance. The role of IFN in the treatment of osteosarcoma can still not be established.

Bone Neoplasms↗