Biomedical subjects

Y Collan

Publications and source records attributed to Y Collan.

At least 91 records · Page 5Linked to original sources

PubMed1986

Toxicity of richterite in hemolysis test and macrophage cultures.

Richterite is a fibrous mineral associated with apatite deposits in eastern Finland. Fibre size features suggest potential toxicity but no data is available of fibrogenic effects on human lungs. The toxicity of richterite in a hemolysis test and in lung macrophage cultures was studied. In the hemolysis test richterite-rich samples showed the same degree of hemolysis as titanium dioxide whereas anthophyllite, crocidolite, chrysotile, wollastonite and quartz samples had distinctly higher degree of hemolysis. In the macrophage toxicity assay the percentage of dead cells was counted, and LDH, ASAT and acid phosphatase were determined from the culture medium. In this assay richterite showed lower toxicity than anthophyllite, crocidolite, chrysotile or quartz but gave higher values than titanium dioxide. Wollastonite showed similar level of toxicity. Differences were statistically highly significant. The results suggest that richterite (with wollastonite) belongs to a group of fibrous minerals which have distinctly smaller biological effect than traditional asbestos minerals.

Animals↗

PubMed1986

Mushroom poisoning due to Cortinarius speciosissimus: electron microscope study in rats.

The effects of a poisonous mushroom, Cortinarius speciosissimus, on rat kidney were studied by transmission electron microscopy. Suspension of dried mushroom (500 mg/kg body weight) was administered as a single dose directly into the esophagus. The kidneys were fixed by perfusion, and both cortex and medulla were sampled. C. speciosissimus toxin acted primarily on the epithelial cells of the proximal tubules. No changes were seen in the glomeruli. First ultrastructural changes were observed at 2 days in the renal cortex. The most prominent damage occurred at 5 days, when most of the proximal tubular cells appeared necrotic. Dark bodies (diameter 0.15-0.5 micron) spaced by 25-45 nm were frequently found in the damaged tubular cell nuclei. Regeneration of the tubular cells was seen at 10 days. After 2 months, increased amount of collagen fibres were seen between tubules. The nuclear changes in the damaged tubular cells and the slowly manifesting toxicity suggest that C. speciosissimus toxin acts on nuclei or nucleoli and/or metabolic pathways associated with them.

Animals↗

PubMed1986

Ethylenethiourea and nabam induced alterations of function and morphology of thyroid gland in rats.

Male Wistar rats were given 0-200 mg/l of nabam and 0-300 mg/l of ethylenethiourea (ETU) in drinking water ad libitum for 28 d to study their effect on thyroid gland function and morphology. Blood samples for RIA hormone assays (T3, T4, TSH) were taken and thyroids of each rat were dissected out for routine light and electron microscopic analysis after sacrifice performed under CO2 anesthesia. Nabam (8.4-30.5 mg/kg bw/d) inhibited dose-dependently T4-secretion and increased T3-secretion, but had no effect on basal TSH-secretion. ETU (10.6-23.4 mg/kg bw/d) inhibited dose-dependently T4- and T3-secretion. ETU also increased basal TSH-secretion tenfold, obviously due to the lack of negative feedback by T4 and T3. Light microscopic analysis revealed neither nabam nor ETU induced morphological alterations in thyroids. Both but especially ETU induced, ultrastructural changes, namely increased number of myelin bodies, dilatation of the rough endoplasmic reticulum, and increased vacuolization in the epithelial cells of thyroid follicles. The functional alterations are obviously connected with, and preceed slight ultrastructural degenerative changes in thyroid follicle epithelial cells even at low doses of nabam, and ETU, after a short-term oral administration.

Animals↗

PubMed1986

Histopathological and morphometrical analysis applied to skin changes in NMRI mice induced by dithranol (anthranil) and its acyl analogs.

Histology and morphometric changes in skin lesions of NMRI mice caused by dithranol and its acyl analogs, with and without pretreatment with dimethylbenzanthracene (DMBA) are described. The course of neoplastic progression seems to have three distinct phases (normal skin, hyperplasia, papilloma), each characterized by typical architectural and cellular changes. The parameters reflecting the nuclear size increased in the above order and the differences between the groups were highly significant. Nuclear shape changes did not take place, as shown by the almost constant form factor. The study demonstrates the value of the morphometric methodology in characterizing quantitative nuclear changes in mouse skin models.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1986

A method for measuring the orientation ("beat direction") of respiratory cilia.

We have created a method for measuring the orientation of cilia in the respiratory epithelium. Ciliary orientation is the direction perpendicular to the plane defined by the central tubules of the cilia and is an estimate of ciliary beat direction. Ciliary orientation can be estimated by measuring the angle between the plane defined by the central tubules and a reference line. The standard deviation of these measurements describes the variation present in the beat directions of the cilia. The reference line must be so chosen that the majority of measurements falls at about the middle of the 0 degree-180 degrees range. We tested measurements by using both a glass angle measure and a semiautomatic image analyzer (IBAS I). The latter approach was faster and more reproducible. We made our measurements of normal tissues on samples obtained from two healthy adult non-smokers. Measurements were made in four areas of each sample, with 59-110 cilia in each. The differences between the maximum and minimum angles of the ciliary orientation in the same area varied from 167.9 degrees to 85.4 degrees from the reference line. The standard deviation varied from 18.0 degrees to 35.4 degrees and we consider this to be a normal variation in ciliary orientation. Of the cilia, 57% were within a standard deviation of 20 degrees.

Adult↗

PubMed1986

Periodic acid-Schiff stain as a prognostic indicator in serous and mucinous ovarian tumors.

The prognostic significance of periodic acid-Schiff (PAS) stain in 112 serous: 43 benign, 25 borderline and 44 malignant cystadenomas: and in 106 mucinous: 60 benign, 32 borderline and 14 malignant cystadenomas of the ovary were investigated. The amount of positively stained mucin was estimated morphometrically. The outcome of most patients with benign or borderline lesion was good. One patient with benign mucinous cystadenoma died, however, of pseudomyxoma peritonei and another patient with borderline mucinous cystadenoma died of peritoneal carcinosis. Other patients were alive and free of the disease after a follow-up of 1-14 years, or had died of causes unrelated to the ovarian disease. Abundant PAS positive mucin predicted a longer survival both in serous and in mucinous malignant tumors. The 5-year survivals for the serous cystadenocarcinomas with and without PAS positive mucin were 21% and 13%, respectively (not statistically significant). For mucinous cystadenocarcinomas with mucin value over and below the median, the 5-year survival rates were 57% and 14%, respectively (P less than 0.10). High PAS positivity in both serous and mucinous cystadenocarcinomas clearly indicated better prognosis, although statistical significance was not achieved. Thus, further studies are needed for final evaluation of the prognostic significance of the PAS stain in these ovarian tumors.

Cystadenocarcinoma↗

PubMed1986

Congenital dermoid cysts of the tongue.

A case of large dermoid cyst in the tongue in a 3 1/2-month-old child is presented. Histologically it was an epidermoid cyst. Typically corresponding cysts are diagnosed during the first four months of life. When the cyst was punctured, some keratin escaped and caused a granulation tissue reaction with granulocytes between the muscles of the tongue. The cyst was treated by marsupialization. No abnormality in the shape or function of the tongue was seen after 24 months.

Dermoid Cyst↗

PubMed1986

A 6-month dermal toxicity test with dithranol and butantrone in miniature swine.

Continuous topical administration of dithranol and butantrone for 6 months caused different irritation profiles in miniature swine. In paraffin wax sticks in white petrolatum, butantrone gave rise to much less initial irritation than dithranol, but after 2-3 weeks the situation had equalized. In gel formulations, butantrone was initially more irritant than dithranol. The vehicles themselves induced significant irritation. Signs of skin hyperplasia (parakeratosis and acanthosis) and inflammation were frequent histopathological findings at the end of the study, but no malignant changes were found. Dithranol and butantrone did not produce any chemical, hematological or serious histological abnormalities during the treatment, suggesting a lack of systemic toxicity. No evidence of systemic absorption was found. This long-term study did not predict delayed irritation of butantrone observed in about 1/3 of the psoriatic patients after treatment for 1-2 months.

Administration, Topical↗

PubMed1986

Quantitation of staining for amyloid in histological sections: sources of variation, correlation analysis, and interstain reproducibility.

Five pathologists estimated with point counting the amount of amyloid in heart muscle autopsy samples from 19 patients who suffered from amyloidosis. The serial sections had been stained with 5 different methods. The different variation sources involved in a quantitative study on amyloid and the interstain reproducibility between the results given by these 5 stains were analyzed. The volume fractions of amyloid after different stains were subjected to correlation analysis. In our test system about a third (34%) of the variation was due to the point counting method. Sirius red had the lowest and Congo red the highest variation due to point counting, since Sirius red gave the most intense staining and highest volume fractions for amyloid. The volume fractions were lowest in Congo red. About 40% of the total variation was composed of the field variation. This variation includes the variation due to variation between fields, field selection and subjective intraobserver variation. Sirius red showed the smallest field variation in respect to the total variation. Congo red, on the other hand, had the highest variation. The variation caused by pure interobserver variation is presented by the difference between total variation and the calculated field variation. This was largest with Sirius red and smallest with Congo red. The pure interobserver variation accounted for about 26% of the total variation. The high reproducibility with Sirius stain is most probably due to the high volume fractions of positively stained material after this stain, not to low interobserver variation. Congo red seems to have low interobserver variation. The senior pathologists were more reliable in measuring the amyloid deposits than the junior pathologists as suggested by interstain reproducibility and variation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amyloid↗

PubMed1986

Evaluation of carcinoembryonic antigen and periodic acid-Schiff stains in the diagnosis of serous and mucinous ovarian tumors: morphometrical study.

108 serous and 104 mucinous neoplasms of the ovary, classified according to the criteria of the World Health Organization, were studied with periodic acid-Schiff (PAS) method for mucin and glycogen, and with immunoperoxidase method for carcinoembryonic antigen (CEA). The amount of epithelium, the number of mitoses, and the staining positivities were quantitated morphometrically and the parameters were evaluated using the discriminant analysis. In general, CEA scores were higher in mucinous than in serous tumors and higher in malignant tumors than in their benign or borderline counterparts. High PAS positivities were found both in serous and mucinous borderline lesions. Mitotic activity correlated with the malignancy of the tumors. The best discriminator, however, was the amount of epithelium. The results show that simple morphometry with standard stains is an efficient method in the first-line classification of these tumors. The quantitation of CEA and PAS stains may be helpful in cases in which histological criteria do not allow definite classification.

Adenocarcinoma, Mucinous↗

PubMed1986

Multivariate classifications of transitional cell tumors of the bladder: nuclear abnormality index and pattern recognition analysis.

The authors report their experiences in applying two types of computer-aided multivariate classification systems in transitional cell tumors of the bladder. The systems are based on nuclear changes in urothelial papillary lesions. 19 out of 54 parameters, selected on the basis of the overlapping area between contiguous grades and the monotonic function, were combined mathematically to obtain the nuclear abnormality index. This index expresses the progressive nuclear abnormalities as a single number on a continuous scale from 0.5 to 2.6. The standard deviation (SD) of the 10 largest nuclear area values in the lower half of epithelial thickness (L), the mean perimeter (L), the SD of the roundness factor in the upper half of epithelial thickness (U), the SD of the logarithm of area (L) and the percentage of round nuclei (U) represent the smallest, the most discriminant and the least correlated set of features for the pattern recognition analysis. The latter shows an agreement of 92% between computer and histologic classifications-estimated by applying Bayes theorem. A good correlation exists between nuclear abnormality index and computer grading by pattern recognition analysis.

Carcinoma, Transitional Cell↗

PubMed1986

Observer variation in interactive computerized morphometry.

The validity of a test system in morphometric histopathology depends on the variation sources involved. Biological variation is one of the variation sources, but is also the object to be studied with morphometry. We studied the variation sources in interactive computerized morphometry in two test systems involving two different commercially available image analyzers. The measurements were made on nuclei in a microscopic field of 5 transitional cell tumors (papilloma and WHO grade I-III carcinomas) of the urinary bladder. It turned out that different observers selected a variable number of nuclei for measurements, the coefficient of variation (CV) in the number of nuclei being 11-11.5%. Mean CV in nuclear perimeter measurements was 4.4-4.8%, and in nuclear area measurements 8.2-8.6%. The variation in measurements by 1 observer was smaller, the CV values being 2.8% for the number of nuclei, 1.2% for nuclear perimeter, and 2.4% for nuclear area. The results showed that interobserver variation can be considerable in these systems. It is suggested that special sampling rules should be tested with the idea of finding the relevant approach with the smallest interobserver variation.

Carcinoma, Transitional Cell↗

PubMed1985

Prevalence of polyps in an autopsy series from areas with varying incidence of large-bowel cancer.

The results of this multicentre autopsy study emphasize the relationship between the prevalence of adenomas and the incidence of large-bowel cancer. The highest proportion of autopsies with adenomas was observed in the area with the highest incidence of large-bowel cancer. The segmental distribution of adenomas within the colon was found to be similar to the site distribution of cancer. However, the lowest proportion of adenomas was found in the rectum, the segment in which cancer is most frequent. The latter finding suggests that either the adenoma-carcinoma sequence is a less important pathway in the pathogenesis of rectal cancer, or that more rectal than colonic adenomas become malignant. The high proportion of hyperplastic polyps in the rectum, and statistically significant regional differences following the same patterns as the incidence of rectal cancer suggest that there could be at least an indirect relationship between hyperplastic polyps and cancer of the rectum. Adenomas of both colon and rectum were more frequent in men than in women, contrary to findings with colon cancer. However, as for colon cancer, the sex ratio of adenomas changed with age, from slightly below unity in persons under 65, to above unity for those aged 65 and over. A major difficulty that emerged was the histological identification of "polyps" because of the degree of autolysis of epithelial cells in the mucous membrane, and this difficulty largely contributed to the poor consistency of histological reporting. Regular consistency surveys of histological preparations should be recommended in any type of multicentre study in which histological examination is included.

Adult↗

PubMed1985

Reproducibility of morphometric measurements of amyloid after various staining methods.

Four histologic staining methods used for detecting amyloid (Congo red, viewed in both normal and polarized light, Sirius red, Crystal violet and Thioflavine T) were applied to heart muscle autopsy samples from 19 patients who suffered from amyloidosis. The amount of amyloid present was evaluated with morphometry (point counting) by five pathologists, and the interobserver reproducibility and variation of point counting in these staining methods were analyzed. The Sirius red method showed the least variation and was the most suitable stain for demonstrating amyloid with respect to reproducibility. Thioflavine T showed the greatest variation and was the least suitable stain with respect to reproducibility. The range of variation was considerable in all staining methods. The results show that stains differ in their specificity and sensitivity in staining amyloid, observers differ in their interpretation of staining results and certain stains result in more uniform interpretations than do others.

Amyloid↗

PubMed1985

Reproducibility and variation of morphometric analysis of carcinoembryonic antigen staining in histopathology. The influence of standardized microscopic fields.

Using morphometric methods, five pathologists analyzed the positive staining for carcinoembryonic antigen (CEA) in sections from 17 ovarian tumors, with the intraclass correlation coefficient (ICC) and the mean values of the coefficients of variation (CV) used to assess reproducibility and variation. First, field and point scores for epithelium and mucin were estimated using 25 randomly selected square fields in sections from each of the tumors. The ICC range in the whole sample field was 0.53 to 0.81 (slight to substantial reproducibility) while the mean values of CV were 0.50 to 0.75. Second, the results of using random and standardized individual fields for the measurements were studied in three tumors. In random fields, the ICC was 0.57 to 0.71 (slight to moderate reproducibility) and the mean values of CV were 0.53 to 0.65. The corresponding values in standardized fields were 0.71 to 0.73 (moderate reproducibility) and 0.41 to 0.57, respectively. The results show that the variation is smaller and the degree of reproducibility higher in standardized fields. Considerable variation remains, however, revealing human factors as an important source of variation in practical morphometry.

Carcinoembryonic Antigen↗

PubMed1985

Stereology and morphometry in histopathology. Principles of application.

The role of stereology and morphometry (including image analysis) in histopathology is considered. Diagnostic histopathology has its own character, which should be considered when quantitative methods are applied. Three different types of studies in histopathology can be distinguished: prospective, retrospective and routine diagnostic studies. The variation in these studies is due to differences in the methods and differences in how the methods are applied. The overall variation is smallest in prospective studies and largest in routine diagnostic studies. Statistical classification of the overall variation does not cover all relevant aspects of the situation in which we study the sample from one individual patient. In that situation, we do not get support from the samples of other patients. In fact, we should speak about group morphometry (statistical morphometry) when samples from several patients are studied and diagnostic morphometry when the sample from one individual patient is under investigation. In the former case, simple morphometric methods may be applicable (the researcher is interested in mean values). In the latter case, one would often like to analyze the sample in more detail. This is why the diagnostic situation may benefit from computerized image analysis, which allows collection of large amounts of data in a short time. On the other hand, the great variation between the pathologic and the normal can allow the use of simple methods. The above basic principles need be considered before morphometric and stereologic methods are applied. These methods are simple in practice and they should be included in the training of all pathologists.

Biopsy↗

PubMed1984

Morphometry in pathology: another look at diagnostic histopathology.

Histopathology is crucial for diagnostic and therapeutic decisions in many disease states. The created classifications, however, have not always allowed explicit recognition of diagnostic categories. So, considerable intra- and interobserver variations are possible under diagnostic circumstances. Better reproducibility can be reached by applying other than traditional methods. These include morphometry as well as special stains, electron microscopy and immunohistochemistry. Morphometry is basic in that in detects structural and morphological aberrations in samples prepared by other methods and without doubt brings the element of accuracy to support the diagnostic decision. Morphometric approach includes item classification and grading, point counting and intersection counting methods, and the use of various semiautomatic or automatic instruments. In statistical morphometry morphometrical parameters are collected from several disease cases. Such data reinforced with prognostic follow-ups are the basis for disease classification. Diagnostic morphometry, on the other hand, tries to study the sample of one individual and give relevant data for diagnostic decisions. Morphometric methods allow estimation of the limits of possible performance in histopathology, estimation of human performance in the diagnostic process and estimation of the influence of interfering human factors. Diagnostic decisions as well as decisions linked with therapy are basically probabilistic. Also the data collected by diagnostic morphometry should be linked with probabilistic estimates of the prognostic relevance of the findings. Education of histopathology should be developed to meet these demands, both at elementary medical level and at postgraduate medical level. Education of morphometry can be incorporated into the medical curricula as shown by the experience at the University of Kuopio where aspects of morphometry are taught during histopathology course and special postgraduate courses have been arranged.

Diagnosis↗

PubMed1984

Ultrastructure of human respiratory cilia: a study based on serial sections.

Ultrastructure of human respiratory cilia was studied in ultrathin serial sections and in random fields of sections. The apex of the cilium had dense gray material under the plasma membrane, where the "central" pair of tubules (often slightly eccentrically placed) and the single peripheral tubules ended. Thereafter the cilium thickened gradually about 1 micron below the apex and after that remained reasonably constant. At about 0.5 micron below the apex was a transformation zone (0.1 micron long), where both double and single peripheral tubules were seen. Dynein arms were not seen in the transformation zone but occurred approximately 0.1 micron below it. In a cilium, one peripheral double tubule was absent in the transformation zone but was seen about 0.2 micron below. This resulted in an artificial 8 + 2 pattern in a few sections. In cross sections at levels with peripheral double tubules the mean of the minor axes of the cilia was 0.198 +/- 0.009 micron (+/- SD) calculated from the serial sections of one patient. In 20 patients the variation was greater and the mean was higher: 0.210 +/- 0.042 micron (+/- SD).

Adult↗