Biomedical subjects

S H Torp

Publications and source records attributed to S H Torp.

At least 19 recordsLinked to original sources

PubMed2005

Ability of navigated 3D ultrasound to delineate gliomas and metastases--comparison of image interpretations with histopathology.

BACKGROUND: The objective of the study was to test the ability of a 3D ultrasound (US) based intraoperative imaging and navigation system to delineate gliomas and metastases in a clinical setting. The 3D US data is displayed as reformatted 2D image slices. The quality of the displayed 3D data is affected both by the resolution of the acquired data and the reformatting process. In order to investigate whether or not 3D US could be used for reliable guidance in tumour surgery, a study was initiated to compare interpretations of imaged biopsy sites with histopathology. The system also enabled concomitant comparison of navigated preoperative MR with histopathology. METHOD: Eighty-five biopsies were sampled between 2-7 mm from the tumour border visible in the ultrasound images. Biopsies were collected from 28 operations (7 low-grade astrocytomas, 8 anaplastic astrocytomas, 7 glioblastomas and 6 metastases). Corresponding cross-sections of preoperative MR T1, MR T2 and intraoperative US were concomitantly displayed, steered by the biopsy forceps equipped with a positioning sensor. The surgeons' interpretation of the images at the electronically indicated biopsy sites were compared with the histopathology of the samples. FINDINGS: The ultrasound findings were in agreement with histopathology in 74% (n = 31) for low-grade astrocytomas, 83% (n = 18) for anaplastic astrocytomas, 77% (n = 26) for glioblastomas and 100% (n = 10) for metastases. Excluding irradiated patients, the results for glioblastomas improved to 80% concurrence (n = 20). As expected tumour cells were found in biopsies outside the US visible tumour border, especially in low-grade gliomas. Navigated 3D US have a significantly better agreement with histopathology than navigated MR T1 for low-grade astrocytomas. CONCLUSION: Reformatted images from 3D US volumes give a good delineation of metastases and the solid part of gliomas before starting the resection. Navigated 3D US is at least as reliable as navigated 3D MR to delineate gliomas and metastases.

Adult↗

PubMed2005

Immunohistochemical detection of epidermal growth factor receptor in human high-grade astrocytomas--a comparison between frozen- and paraffin sections.

The overexpression of epidermal growth factor receptor (EGFR) in human astrocytic tumours is associated with the oncogenesis of these tumours. Ongoing research on diagnostic, prognostic, and therapeutic aspects of this receptor is highly dependent on the development of reliable techniques for the detection of EGFR in tumour tissue. The aim of this study was to assess EGFR expression in human high-grade astrocytomas by means of immunohistochemistry on formalin-fixed, paraffin-embedded sections and to compare these findings with the results of our previous study on frozen sections from these tumours, in which we found about 60% EGFR positivity (10). Four anaplastic astrocytomas and 19 glioblastomas were included in this study. Two different antibodies were used, the monoclonal antibody E30 reactive against the extracellular domain of EGFR and the polyclonal antibody Ab-4 directed against its cytoplasmic domain. With E30, 3 out of 4 anaplastic astrocytomas (75%) and 12 out of 19 glioblastomas (63%) were found to express EGFR whereas Ab-4 demonstrated positive EGFR immunoreactivity in most of the tumours (18/19 glioblastomas and all the 4 anaplastic astrocytomas). In conclusion, immunohistochemistry represents a reliable and convenient technique for the detection of EGFR in tissue sections of human high-grade astrocytomas, and that EGFR immunoreactivity is comparable in frozen- and paraffin sections from these tumours.

Astrocytoma↗

PubMed2004

Hypergastrinaemia induced by partial corpectomy results in development of enterochromaffin-like cell carcinoma in male Japanese cotton rats.

BACKGROUND: Among inbred female cotton rats (Sigmodon hispidus) 25%-50% of the animals develop spontaneous gastric carcinomas, whereas males have an incidence of less than 1%. The carcinomas are enterochromaffin-like (ECL)-cell derived. Animals with gastric carcinomas also have hypergastrinaemia and gastric hypoacidity, but the mechanism behind the hypoacidity is unknown. Carcinomas have been found in all female cotton rats with spontaneous hypergastrinaemia lasting more than 4 months, and a gastrin receptor antagonist prevents the development of carcinoma. The purpose of the present study was to investigate whether induced hypergastrinaemia in male cotton rats would also result in carcinomas. METHODS: Hypergastrinaemia was induced by partial corpectomy of male cotton rats, aiming at removal of 80%-90% of the corpus. A control group was sham-operated. RESULTS: All partially corpectomized animals developed persistent hypergastrinaemia. Six months after the operation, 9 out of 13 partially corpectomized animals developed gastric cancer. In the dysplastic mucosa surrounding the tumours there was an increase in chromogranin A immunoreactive cells, where numerous cells also were stained using the Sevier-Munger technique. Tumour tissue also contained cells that were chromogranin A positive and stained by Sevier-Munger. CONCLUSIONS: ECL-cell carcinomas can be induced in male cotton rats by partial corpectomy. This supports a previous statement that spontaneous carcinomas in female cotton rats are caused by gastric hypoacidity and hypergastrinaemia. In hypergastrinaemic animals, ECL-cell carcinomas develop independently of gender within a relatively short period of time, and cotton rats therefore represent an interesting model for studying gastric carcinogenesis.

Animals↗

PubMed2004

Spontaneous enterochromaffin-like cell carcinomas in cotton rats (Sigmodon hispidus) are prevented by a somatostatin analogue.

Among inbred female cotton rats (Sigmodon hispidus) 25-50% of the animals develop spontaneous gastric carcinomas; the corresponding figure for male cotton rats is approximately 1%. Animals with carcinomas have hypergastrinaemia and gastric hypo-anacidity and the tumours are derived from enterochromaffin-like (ECL) cells. The mechanism behind the hypo-anacidity is unknown. Carcinomas are found in all female cotton rats with hypergastrinaemia lasting more than 4 months and this represents an excellent animal model for studying gastric carcinogenesis. In this study, the somatostatin analogue octreotide was given to female cotton rats to prevent carcinoma development caused by hypergastrinaemia. Twelve female cotton rats were given monthly injections of long-acting octreotide (5 mg i.m.) for 6 months. A control group of 20 animals was not given injections. Of the 20 control animals, 13 developed hypergastrinaemia and histologically invasive carcinomas or dysplasia. Of the 12 animals in the octreotide group, five developed hypergastrinaemia. None of these five animals developed histological cancer (P<0.05), whereas three had dysplasia. However, octreotide did not affect plasma gastrin concentration or antral gastrin mRNA abundance significantly. Dysplasia of the oxyntic mucosa in hypergastrinaemic animals was accompanied by a marked increase in chromogranin A-immunoreactive cells and cells positive for Sevier-Munger staining. The malignant tissue also contained groups of cells with Sevier-Munger staining. In conclusion, octreotide prevented ECL cell carcinomas in hypergastrinaemic cotton rats without lowering the gastrin concentration.

Animals↗

PubMed2003

Determination of proliferation index in neoplasms using different Ki-67 equivalent antibodies.

Paraffin sections from 23 tumours were immunohistochemically stained with the following four Ki-67 equivalent antibodies: monoclonal MIB-1 (DAKO), monoclonal MM1 (Novocastra), polyclonal NCL-Ki-67p (Novocastra), and polyclonal Rah Ki-67 (DAKO). Ki-67 labelling indices were determined by counting in exactly the same area in each case. MIB-1 showed the highest labelling index in 21 of the 23 cases, and the mean MIB-1 index was approximately 30% higher than that of the other antibodies. The differences between MM1, NCL-Ki-67p and Rah Ki-67 were small and non-significant. There was a positive correlation between each of the four antibodies. As these findings may be of importance when the Ki-67 labelling index is used as a criterion for tumour grading or for clinical prognostication, this necessitate identification of the antibody used in every case.

Antibodies, Antinuclear↗

PubMed2002

Comparison of Ki-67 equivalent antibodies.

AIMS: To compare commercially available Ki-67 equivalent antibodies with regard to qualitative and quantitative immunohistochemical staining characteristics. METHODS: The following antibodies were used: monoclonal MIB-1 (Immunotech), monoclonal MM1 (Novocastra), polyclonal NCL-Ki-67p (Novocastra), and polyclonal Rah Ki-67 (Dako). All immunostainings were evaluated in squamous epithelium from formalin fixed and paraffin wax embedded pharyngeal tonsils. Labelling indices (LIs) were recorded twice to test their reproducibility. RESULTS: By application of all four antibodies the nuclear staining could be either diffuse, granular, or a combination of both (classified as granular in this study). The diffuse pattern generally showed a strong or moderate staining intensity, whereas the granular pattern displayed a continuum from strong to very weak, making it difficult to discriminate between positive and negative nuclei. The diffuse staining pattern was seen in approximately 59% of the nuclei with the MIB-1 antibody and in 35-45% when the other antibodies were used. The following mean LIs were recorded: MIB-1, 31%; NCL-Ki-67p, 21%; Rah Ki-67, 17%; and MM1, 14%. The reproducibility was excellent for all four antibodies, with the mean of differences between the two runs of counts ranging from 1.1% to 1.5%. CONCLUSIONS: The four tested Ki-67 equivalent antibodies revealed differences in qualitative and quantitative staining characteristics, which resulted in considerable variations in registered LIs. The MIB-1 antibody appears to have a higher sensitivity for detecting the Ki-67 antigen than the other three tested antibodies. These differences are important to consider when proliferative activity is determined by the Ki-67 LI.

Adult↗

PubMed2001

Proliferative activity in human glioblastomas assessed by various techniques.

Determination of proliferative activity in tumours may be valuable in diagnosis and prognosis. In this study, commonly used proliferation markers were investigated and compared in 12 cases of human glioblastoma. Paraffin sections were incubated with four commercial Ki67-equivalent antibodies, anti-PCNA, and anti-bcl-2. S-phase fraction and mitotic activity were determined as well. The different Ki67 antibodies gave satisfactory immunostainings, though they provided a wide range of proliferation indices (PI) intra- and intertumorally. Correlations between the Ki67 antibodies and the other proliferation markers were, broadly speaking, poor. PCNA immunostaining was hampered by disturbing background staining. Few bcl-2-immunoreactive cells were observed, mainly gemistocytes. Flow cytometric analyses provided reliable S-phase fraction values, and two aneuploid tumours were detected. The mitotic activity was generally high. Thus, mitotic counting remains a convenient method for assessing proliferative activity in astrocytic tumours. Ki67 antibodies are important alternatives, for instance in stereotactic brain biopsies. Under all circumstances, proliferation markers should be used in combination with established histopathological criteria for malignancy in these tumours.

Adult↗

PubMed2000

Fetuses and infants with congenital urinary system anomalies: correlation between prenatal ultrasound and postmortem findings.

OBJECTIVE: Detection of congenital urinary system anomalies is an important part of the prenatal ultrasound examination. The present study compares prenatal ultrasonographic findings and postmortem examinations of fetuses and infants with renal and urinary tract anomalies. DESIGN: Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine (Trondheim, Norway) and autopsy performed during the period 1985-94. Results from the ultrasound examination and autopsy regarding urinary system anomalies were categorized according to the degree of concordance. RESULTS: Urinary system anomalies were found in 112 (27%) of 408 fetuses with congenital anomalies. The renal and/or urinary tract anomaly was the principal reason for induced abortion or cause of death in 50 cases (45%). In 97 (87%) of the 112 cases there was full agreement between the ultrasound observations and the autopsy findings. In five cases the autopsy revealed minor findings not mentioned in the ultrasound report. The main diagnosis was thus correct in 102 cases (91%). In four cases major autopsy findings had not been found by ultrasound examination; in another four, none of the autopsy findings were suspected by ultrasound, and in two, minor ultrasound findings were not confirmed at autopsy. CONCLUSIONS: The accordance between ultrasound diagnoses and postmortem examinations proved to be satisfactory. The close co-operation between ultrasonographers and perinatal pathologists is mutually beneficial. In addition to complementing prenatal diagnosis, postmortem examination is of vital importance for the quality control of ultrasonography in fetal diagnosis and plays an important role in genetic counseling.

Autopsy↗

PubMed2000

A correlative study of prenatal ultrasound and post-mortem findings in fetuses and infants with an abnormal karyotype.

OBJECTIVE: To compare ultrasound and post-mortem findings in 98 fetuses and infants with an abnormal karyotype. DESIGN: Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine (NCFM), an abnormal karyotype, and an autopsy performed during the period 1985-94. RESULTS: Trisomy 18 and 21 were the two most common abnormal karyotypes. The highest number of congenital anomalies was observed in cases with trisomy 13 and 18; congenital heart defects (CHD) were most prevalent among fetuses with trisomy 18. In 80% of cases there was full agreement between the ultrasound and autopsy findings; in another 8% of cases there was nearly complete concordance. Thus, in 88% of cases, the main prenatal sonographic diagnosis was correct. In 6% major autopsy findings were not detected by ultrasound examination, in 1% none of the autopsy findings were detected by routine ultrasound and in 5% ultrasound findings were not verified at autopsy. Where the correlation was related to individual autosomal trisomies, structural anomalies were most often correctly diagnosed in fetuses with trisomy 13, with the main diagnosis correct in all cases; second in accuracy were the ultrasound diagnoses in fetuses with trisomy 21 with the main diagnosis correct in 96%; for trisomy 18 the concordance was less good, with the main diagnosis correct in 71%. CONCLUSION: The present comparison of sonographic diagnoses with post-mortem findings demonstrates good accordance between the two methods. It also demonstrates the importance of awareness of the anomalies known to occur with different aneuploidies.

Aneuploidy↗

PubMed1999

[Telepathology in Mid-Norway].

Telepathology can provide frozen section service to hospitals without a pathology service of their own. Using a dynamic-robotic system with 6 ISDN B-channels (Telemed A200, AM Elektronikk A/S, Oslo, Norway), the pathologists at the University Hospital in Trondheim, Norway during a three-year period from 1995 successfully performed 116 diagnostic sessions for two rural Norwegian hospitals. In 90% of the cases a diagnosis was provided. There was no false positive diagnosis and only 3% false negative cases without clinical consequence. Deferred cases (10%) were mainly due to poor quality of the frozen sections and a conservative attitude among the pathologists. It is concluded that the diagnostic accuracy is good, but for safety reasons telepathology should be offered on a regular basis, so that the skills of the technicians and pathologists involved are kept up. In Mid-Norway, five more hospitals will be included in a telemedicine network comprising eight hospitals in the region.

Attitude of Health Personnel↗

PubMed1999

[Brain stem infection caused by Listeria monocytogenes].

Rhombencephalitis due to Listeria monocytogenes is a serious form of brainstem inflammation. It is difficult to diagnose on the basis of clinical and laboratory findings alone. We describe a fatal case of Listeria monocytogenes rhombencephalitis in a previously healthy female teenager. Clinical and pathogenetic aspects of this condition are discussed.

Adolescent↗

PubMed1999

Comparison of prenatal ultrasound and postmortem findings in fetuses and infants with congenital heart defects.

OBJECTIVE: Detection of congenital heart defects by prenatal ultrasound examination has been one of the great challenges since the investigation for fetal anomalies became part of the routine fetal examination. This prospective study was designed to evaluate the concordance of prenatal ultrasound findings with autopsy examination in a population consisting of both referred women and non-selected pregnant women. DESIGN: Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine and an autopsy performed during the years 1985-94. Results from the ultrasound and autopsy examinations were systematized into categories depending on the degree of concordance. RESULTS: Of 408 infants and fetuses with developmental anomalies, 106 (26%) had congenital heart defects. In 63 (59%) of these 106 cases, the heart defect was the principal reason for the termination of pregnancy or the cause of death. Excluding five cases with a secundum atrial septal defect, there was complete agreement between the ultrasound examination and the autopsy findings in 74 (73%) of 101 cases. In 18 cases, there were minor discrepancies between ultrasound and autopsy findings. The main diagnosis was thus correct in 92 cases (91%). From the first time period (1985-89) to the second (1990-94), the detection rate of all heart defects increased from 48% to 82%. CONCLUSION: This study confirms a good correlation between ultrasound and autopsy diagnoses in fetuses and infants with congenital heart defects. A significant improvement in the detection of heart defects occurred from the first time period to the second and was probably due to increased experience and technical advances.

Abnormalities, Multiple↗

PubMed1998

Comparison of prenatal ultrasound and postmortem findings in fetuses and infants with central nervous system anomalies.

Detection of fetal developmental abnormalities by ultrasound examination of pregnant women has become a specialized field of medicine. Quality control of this field requires detailed examination of aborted fetuses. In 408 fetuses and infants with developmental anomalies, the prenatal ultrasound findings were compared with the post-mortem findings. This study focused on 140 central nervous system (CNS) anomalies. Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine (NCFM) and an autopsy performed during the period 1985-94. Results of the ultrasound and autopsy examinations were systematized into six different categories. Hydrocephaly and anencephaly were the most frequent abnormalities, together accounting for 50% of the CNS anomalies. In 20 cases (14%), the CNS anomalies were associated with other important anomalies or chromosomal aberrations. In 125 of the cases (89%), there was complete concordance between the ultrasound and autopsy diagnoses. Of the 15 CNS cases with discrepancies, seven had nearly complete concordance; if we include these, the correlation was 94%. In conclusion, this study confirms that developmental anomalies in the central nervous system are frequent and that ultrasound diagnoses are in good concordance with the autopsy diagnoses.

Adolescent↗

PubMed1997

Proliferative activity in human glioblastomas: evaluation of different Ki67 equivalent antibodies.

AIMS: Determination of proliferative activity in human gliomas may be of clinical importance. Immunohistochemical estimation of the proliferative index with the prototypic monoclonal antibody Ki67 is often used but has the disadvantage that it must be carried out on frozen material. However, novel Ki67 equivalent antibodies have been developed for use on formalin fixed and paraffin wax embedded tissue. In this study, the prototypic Ki67 antibody and several new Ki67 equivalent antibodies were tested on human glioblastoma tissue. METHODS: Eleven glioblastomas were included in the study. The antibodies used were the prototypic monoclonal Ki67 and the novel Ki67 equivalent antibodies MIB1 (monoclonal), NC-MM1 (monoclonal), NC-Ki67p (polyclonal), and rabbit antihuman Ki67 antigen (polyclonal). The prototypic Ki67 was used on frozen sections and the other Ki67 antibodies on microwave oven heated, formalin fixed and paraffin wax embedded sections. RESULTS: All antibodies exhibited specific granular nuclear staining of weak to strong intensity. In some tumours the labelling indices were within the same range, whereas in others the antibodies elicited divergent values. CONCLUSIONS: All the novel Ki67 equivalent antibodies provided satisfactory staining on paraffin sections. However, a significant spread of labelling indices was recorded in some cases. Therefore, Ki67 immunostaining is encumbered with some degree of uncertainty and requires further optimisation before it can be regarded as a reliable prognostic marker.

Aged↗

PubMed1996

Long-term effects of inhaled nicotine.

Tobacco smoking has been reported to be associated with increased risk of cardiovascular disease and cancer, particularly of the lungs. In spite of extensive research on the health effects of tobacco smoking, the substances in tobacco smoke exerting these negative health effects are not completely known. Nicotine is the substance giving the subjective pleasure of smoking as well as inducing addiction. For the first time we report the effect on the rat of long-term (two years) inhalation of nicotine. The rats breathed in a chamber with nicotine at a concentration giving twice the plasma concentration found in heavy smokers. Nicotine was given for 20 h a day, five days a week during a two-year period. We could not find any increase in mortality, in atherosclerosis or frequency of tumors in these rats compared with controls. Particularly, there was no microscopic or macroscopic lung tumors nor any increase in pulmonary neuroendocrine cells. Throughout the study, however, the body weight of the nicotine exposed rats was reduced as compared with controls. In conclusion, our study does not indicate any harmful effect of nicotine when given in its pure form by inhalation.

Administration, Inhalation↗

PubMed1995

Comparison of different Ki67 antibodies in human glioblastomas.

Aims-To compare immunostaining between the original Ki67 monoclonal antibody and a new polyclonal Ki67 antibody on frozen and paraffin wax sections of human glioblastomas.Methods-Frozen sections and formalin fixed, paraffin wax embedded sections of the same tumour specimens were included in the study (10 cases). Half of the paraffin wax sections were pretreated in a microwave oven. Standard immunohistochemical techniques were used (avidinbiotin peroxidase complex). Five high power fields were examined using an eye-piece graticule, and 500 to 2000 tumour cells were counted. The labelling index was defined as the percentage of positive tumour cells.Results-The Ki67 monoclonal antibody displayed positive immunostaining in all frozen sections (median labelling index 5.9, range 2.6-11.4) whereas only four paraffin wax sections stained positively and only after pretreatment in a microwave oven. The polyclonal Ki67 antibody elicited positive staining in both frozen sections (median labelling index 13.7, range 6.7-21.5) and in paraffin wax sections (median labelling index 12.0, range 2.2-22.7) but only after pretreatment in a microwave oven.Conclusion-The Ki67 monoclonal antibody is not recommended for use on paraffin wax sections of glioma tissues whereas the new polyclonal Ki67 antibody provides satisfactory immunostaining on both frozen and paraffin wax sections.

Journal Article↗

PubMed1993

C-erbB-2/HER-2 protein in human intracranial tumours.

Normal and neoplastic human intracranial tissues were examined by immunohistochemistry for c-erbB-2/HER-2 protein expression. Positive staining was observed in 1/41 gliomas, 1/2 medulloblastomas, 1/1 germinoma, 11/16 meningiomas, 1/3 anaplastic meningiomas and 11/19 metastatic brain carcinomas. No positive staining was observed in normal intracranial tissues. Thus, the expression of the c-erbB-2/HER-2 protein is limited to intracranial tumour tissues, principally meningiomas and metastatic carcinomas to the brain.

Adult↗

PubMed1992

Relationships between Ki-67 labelling index, amplification of the epidermal growth factor receptor gene, and prognosis in human glioblastomas.

The aim of this study was to determine possible relationships between Ki-67 labelling index (Ki-67 LI), amplification of the epidermal growth factor receptor (EGFR) gene, and prognosis in human glioblastomas. Ki-67 LI was determined on cryosections of biopsy specimens of 20 human glioblastomas with a mouse anti-human Ki-67 monoclonal antibody. Amplification of the EGFR gene was determined by slot blot and Southern blot analyses of DNA extracted from the tumour biopsies. The Ki-67 LI was higher in the glioblastoma group with EGFR gene amplification (8 tumours, median value of Ki-67 LI 4.2, range 0.4-24.6) than in those without EGFR gene amplification (12 tumours, median value of Ki-67 LI 0.8, range 0.2-11.8) (0.05 p less than 0.1). The glioblastoma patients with Ki-67 LI greater than 1.5 (10 tumours) had a statistically significant shorter survival than those with Ki-67 LI less than 1.5 (10 tumours) (p less than 0.05). The glioblastoma patients with EGFR gene amplification lived shorter time than those without EGFR gene amplification (p greater than 0.05).

Actuarial Analysis↗