Biomedical subjects

Y Collan

Publications and source records attributed to Y Collan.

At least 181 records · Page 10Linked to original sources

PubMed1979

Mortality among Finnish doctors, 1953-1972.

The mortality with respect to the total population of Finnish physicians during the period 1953 to 1972 has been analysed and compared with the corresponding statistics for the general Finnish population, for Finnish foundry workers, and for American physicians. It was found that the overall mortality was lower for male physicians than that for the general population or for foundry workers, but was clearly higher than that for American physicians. Male physicians did not exhibit any major differences from the general population with regard to cardiovascular diseases and suicide, but had a lower mortality from malignant neoplasms, accidents and "other diseases" (including infectious diseases). The explanation of cancer mortality being lower than expected among male physicians was mainly to be found in a deficit in lung cancer. Although female physicians had higher life expectancy than male physicians and the female general Finnish population, they did not show any clear deficit for cancer. In respect of all specialists, surgical specialists had the lowest mortality; general practitioners had the highest mortality. Most of these variations were attributable to differences in coronary mortality, but mortality from lung cancer was also remarkably low among surgeons. Differences of a similar type were also found between occupational sub-categories; private practitioners had the highest, and research workers and central hospital physicians the lowest mortality figures. The lower cancer mortality among male physicians, as contrasted with the general population, is probably attributable to differences in smoking habits; about 22% of male physicians smoked in 1973, whereas earlier studies by others have indicated that the corresponding proportion was about 50% in the general population. In contrast, the differences in mortality between different specialist categories probably arises from other factors, since Finnish physicians reportedly display a relatively homogeneous smoking pattern.

Adult↗

PubMed1979

Effects of intermittent styrene inhalation, ethanol intake and their combination on drug biotransformation in rat liver and kidneys.

The modifying effects of daily ethanol ingestion in the drinking water as a 15 % solution (v/v) on drug biotransformational changes induced by inhalation exposure to styrene (300 ppm or 1260 mg/m3, 6 h daily, 5 d/week, up to 17 weeks) were studied in rat liver and kidney. The drug hydroxylation activities (7-ethoxycoumarin O-deethylase and 2,5-diphenyloxazole hydroxylase) both in liver and in kidneys were increased more by ethanol ingestion than by styrene inhalation. When administered in combination, styrene and ethanol exerted mostly an additive enhancing effect. However, hepatic NADPH-cytochrome c reductase activity was reduced both in styrene and in ethanol-treated rats. Hepatic styrene oxide hydratase activity was virtually unaffected by styrene treatments. The depression of glutathione concentration in liver was greater after styrene-ethanol than after styrene treatment alone. The hepatic UDPglucuronosyltransferase activity was enhanced slightly both in styrene and in styrene-ethanol rats. The binding affinity of styrene towards cytochrome P-450 was increased after styrene inhalation as shown by lowered K8 values. The perirenal fat concentration of styrene showed a rough inverse relationship to the overall monooxygenation activities in liver and kidney. Despite the additively induced enzyme activities in styrene-ethanol-treated rats the accumulation of styrene in fat of these animals was on the whole somewhat greater, suggesting that these two solvents in vivo also have mutual inhibitory effects on biotransformation.

Animals↗

PubMed1978

Electron Microscopy of Nephropathia Epidemica. Glomerular changes.

Electron microscopical changes in the glomeruli in 20 kidney biopsies from 18 patients, who were suffering from or had lately suffered from Nephropathia epidemica were studied. Various kinds of deposits were seen. Under the endothelial cells there were collections of light flocculent material. Small dark deposits were seen in the mesangium at the mesangial cell processes, inside the thickened basement membrane, and occasionally on the epithelial side of the membrane. Large deposits were seen around mesangial cells in the mesangium. Deposits were less numerous than in chronic immune complex diseases. The intramembranous or subepithelial deposits were associated with "moon craters", membranous convoluted structures or membrane debris. Granular extracellular mesangial material, round extracellular particles and intraendothelial microtubular inclusions were occasionally seen. In two of our cases occasional capsular epithelial cells showed numerous myelin bodies. Typical viruses were not seen in the glomeruli. The findings are in accord with the short period of scanty immune complex deposition in the glomeruli in the clinically active phase of Nephropathia epidemica.

Adolescent↗

PubMed1978

Ultrastructural features of spiral ganglion cells. A study of patients with hearing loss of varying origins.

Fresh specimens of the acoustic nerve that were obtained during vestibular neurectomy or acoustic neuroma removal were studied for structure of the spiral ganglion cells. These were large, round or oval cells with many cytoplasmic organelles and were surrounded by Schwann cells. Schwann cells formed a single layer or perikaryal sheath and the cells were thus unmyelinated. In one case the specimen contained part of the spiral ganglion, but in six others spiral ganglion cells were found outside of Rosenthal's canal, among the myelinated nerve fibers. In three cases the ear was deaf due to cochlear insult, but the nerve fibers and ganglion cells showed no retrograde degeneration. The neurophysiologic features of the cochlear nerve should be considered because unmyelinated ganglion cells may have a different conduction capacity in comparison with thickly myelinated cells.

Adult↗

PubMed1978

Pathologic features of the cochlear nerve in profound deafness.

Cochlear nerves transected in the internal meatus were studied in six totally deaf ears and in one ear with profound deafness. In five ears deafness had followed surgical procedures in the oval window, in one it was the result of a mumps infection, and one was probably due to a virus infection or a vascular lesion. In four cases there was no great reduction in the nerve fiber population and the ultrastructure appeared normal. In three nerves there was a reduction in the number of nerve fibers, interfibrillar fibrosis, and disorganized material or extensive degenerative changes in the myelin sheaths. In all specimens artificial myelin changes were seen that apparently resulted from manipulation of the specimens at removal. Analysis of these cochlear nerves suggests that retrograde degeneration after severe cochlear insults may not be as frequent as has been thought on the basis of animal studies.

Adult↗

PubMed1978

Eighth nerve in acoustic neuromas. Special reference to superior vestibular nerve function and histopathology.

Eighth nerve specimens were removed during acoustic neuroma surgery, and findings were related to cochlear and especially to superior vestibular nerve function as studied by conventional caloric testing in 21 cases. The origin of the tumor was in eight cases the inferior and in two cases the superior vestibular nerve, and in eight cases the vestibular nerve without more specific localization. In three advanced cases the exact site of origin could not be determined. Leaving age-related changes out of account, the utricle and horizontal canal ampulla appeared normal in all ears except one in which the ampulla was replaced by tumor tissue. In 11 ears the superior vestibular nerve was histologically intact and three of these ears also showed normal caloric responses. In seven ears there was a canal paresis, and in three no reaction was obtained. The ten ears with partial or total nerve invasion by tumor either showed a weak reaction or no response at all. It is likely that an early conduction block arises in both cochlear and vestibular nerves, and reduced reactions to appropriate stimuli do not warrant conclusions that the numbers of anatomically intact nerve fibers possibly are reduced.

Adult↗

PubMed1978

Cochlear nerve in neurilemomas. Audiology and histopathology.

Correlative data between the histopathologic changes in the cochlear nerve and audiologic findings are reported in 16 cases of neurilemomas. Poor speech discrimination, positive or absent recruitment, excessive adaptation, or separation of forward vs reverse continuous tone Bekesy tracings did not correlate with the number of preserved nerve fibers. There were several cases with profound hearing loss in which the nerve fiber population approached normal. Histologically, pathologic changes included dilated fibers and increased interfibrillary collagen. In many specimens the fibers were further apart than normally, especially in the immediate vicinity of the tumor, and many lay between tumor cells. The tumor-nerve interface was usually gradual and no abrupt change appeared at the transition from the nerve to the tumor, the Schwann cells appearing to continue as tumor cells. Nonspecific changes apparently due to specimen handling were seen in some areas of most specimens.

Adult↗

PubMed1978

Hereditary gingival hyperplasia and physical maturation.

In a family with eight children, six of the children suffered from gingival hyperplasia. Dental age was determined for five of the affected children. In four it was retarded in relation to chronologic age, but within normal limits. The skeletal age of the same five children was retarded by more than 2 standard deviations. The heights of three of these five children were clearly below the 2.5th percentile height curve. The two most retarded children were examined by pediatricians. No hematologic changes or evidence of malabsorption from the alimentary tract could be found. It is suggested that in this family retardation of physical development may be linked with gingival hyperplasia.

Adolescent↗

PubMed1978

Hereditary fibrous hyperplasia of the gingiva with varying penetrance and expressivity.

A kindred affected with hereditary fibrous hyperplasia of the gingiva with varying penetrance and expressivity is described. Most of the affected members were short in stature. The pedigree strongly suggested an autosomal dominant mode of inheritance. The penetrance of the trait varied, and three unaffected persons had transmitted the disease to their offspring. There were two modes of expression. The mild form showed only bilateral rugose thickening of the palate, whereas the severe form showed gingival hyperplasia in addition to changes in the palatal mucosa. The changes were already present at birth. Histological examination showed large amounts of alcian blue-positive extracellular material in the subepithelial connective tissue of the hyperplastic mucosa. Loose collagen-poor connective tissue with alcian blue-positive extracellular material and dense collagen-rich connective tissue in the rugose projections of the palatal mucosa were often segregated.

Adolescent↗

PubMed1978

Electron microscopy of exfoliated cells of human oral mucosa.

Exfoliated cells of the human buccal mucosa were studied in 35 adults. All cells showed signs of necrosis: condensation of nuclear chromatin, dilated mitochondria with flocculent densities, dilation of endoplasmic reticulum, ribosomes detached from the endoplasmic membranes, aggregates of degenerated organelles in the cytoplasm, and discontinuity of nuclear and plasma membranes. Desmosomes were preserved in cells exfoliated in groups, but in single cells the former sites of desmosomes were only occasionally identified. The cells contained filaments about 150 A in diameter, often arranged in bundles around aggregates of degenerated organelles. Ruthenium red stained the glycocalyx of the epithelial cells and the capsule of accompanying bacteria. The glycocalyx did not appear to contribute to binding the bacteria to cell surfaces. The findings are discussed in the light of recent studies on cell necrosis, and culminate in a hypothesis to explain exfoliation of cells of the oral epithelium.

Adolescent↗

PubMed1978

Renal sequelae to nephropathia epidemica.

Clinical data and renal biopsy findings were studied in 9 patients 4-5 years after the acute phase of Nephropathia epidemica. Laboratory data suggested slightly depressed tubular function, but glomerular function was normal. Light microscopy of renal biopsy specimens showed slight residual interstitial fibrosis and occasionally atrophic tubuli, tubular casts, increased number of hyalinized glomeruli, and minor changes in other glomeruli. Two specimens showed fibrotic scars in the cortex. Electron microscopy revealed degenerative changes in the glomeruli, arterioles and tubules. The immunohistochemical study showed no fixed immunoglobulins in the kidney. The study shows that practically complete and lasting clinical recovery follows the acute phase of Nephropathia epidemica and that the disease does not leave diagnostic structural changes in the kidneys.

Adult↗

PubMed1978

Familial syndrome with panhypopituitarism, hypoplasia of the hypophysis, and poorly developed sella turcica.

Two sisters who died at the age of 2.5 years and 5 weeks are described. Both showed signs of panhypopituitarism. At necropsy, no hypophysis could be found in the first child and a rudimentary and partly ectopic hypophysis was found in the other. Both children had a flat, poorly developed sella turcica, and the sellar anomaly could be seen in skull x-rays. These patients represent a hereditary syndrome characterised by neonatal panhypopituitarism, hypoplasia of the pituitary gland, and flat sella turcica.

Child, Preschool↗

PubMed1978

Revision of light-microscopic kidney biopsy diagnosis in glomerular disease.

Paraffin-embedded kidney biopsies sent to our laboratory in 1967 were re-embedded in Epon and studied with electron and light microscopy (1-micrometer thick sections). Of 28 biopsies with enough material 18 were cases with clinical suspicion and symptoms of glomerular disease. In electron microscopy all of these were shown to be of glomerular origin by demonstrating either dark deposits in or at the basement membrane, or amyloid fibrils, or areas with retraction of the foot processes of the epithelial cells. Original light microscopy in 1967 had given proof of glomerular origin in 9 of these 18 cases. Light microscopy of plastic sections of these originally paraffin-embedded biopsies was also helpful in diagnosis and showed deposits in 9 out of 14 cases with ultrastructural deposits. The study shows that considerable benefits can be gained through re-embedding biopsies in plastic, especially in cases with minor alterations.

Adult↗

PubMed1978

Transitional cell tumours of the urinary bladder. The histological grade (WHO) and the clinical stage (UICC).

Correlation of histological grade (WHO) with clinical stage (UICC) of transitional epithelial tumours of the bladder has been evaluated in 130 patients. A moderate statistically highly significant positive correlation was established (Pearson's r 0.37--0.75 and eta correlation ratio coefficient 0.49--0.81 in various subsets of the material). Transurethral biopsies gave on average 0.53 lower histological grade than open operative biopsies of the same tumours. The data show that the information contained in histological grade and clinical stage is parallel and support the idea that histological diagnosis of transitional cell carcinoma is possible also in the absence of histological evidence of invasion.

Aged↗

PubMed1978

Oesophageal diverticula. A follow-up study of 34 patients.

Of the 34 patients treated surgically for oesophageal diverticula during a 17-year yperiod, 14 had Zenker's and 20 thoracic diverticula. In addition to three diverticular perforations, the selection of the patients for surgery was based on major symptomatology and roentgenological retention in the diverticulum. The most usual method was a simple diverticulectomy. One patient was lost because of an oesophagopleural fistula, while non-lethal complications occurred in 10 patients. Twenty-nine patients were available for the follow-up study, which was made, on an average, 5.5 years postoperatively. Four had died of other causes. Seventeen patients regarded the results as good and 11 as acceptable. A roentgenological recurrence was detected after six Zenker's and four thoracic diverticulectomies by using the hypotonic double contrast method. Most recurrences caused only minor symptoms, if any. Two new diverticula were found in addition to the recurrences. Only one patient was reoperated on, while the slight discomfort felt by the others was not considered an indication for surgery.

Adult↗

PubMed1978

Nephropathia epidemica: immunohistochemical study of pathogenesis.

Renal immunohistochemistry was studied in 21 patients with Nephropathia epidemica, a benign hemorrhagic fever endemic in northern Europe. Between days 4 and 25 after the onset of fever, scanty but distinct deposits containing immunoglobulins and C3 were detected in glomeruli and tubules. The occurrence of deposits was verified with electron microscopy. It is concluded that an immune complex mechanism plays a part in the pathogenesis of this disease. It is also evident that the febrile period coincides with the presence of immune complexes in the circulation.

Adolescent↗

PubMed1978

Electron microscopy of nephropathia epidemica. Renal tubular basement membrane.

Tubular basement membranes in kidney biopsies from 18 patients with nephropathia epidemica were studied by electron microscopy. Both in the cortex and in the medulla there was splitting of the basement membrane. Thickened basement membrane around occasional tubules contained membrane vesicles, usually empty but also with a core and a diameter of approximately 180 nm. Membranous convoluted structures and light finely fibrillar areas in the basement membranes were seen. Splitting of the basement membrane was most prominent in the medulla, and the membrane was filled with round to oval particles 55 to 470 nm in diameter. Of the possible mechanisms of damage at the basement membrane level in this disease, the findings suggest liberation of antigen from the tubular cells and reaction of circulating antibodies with the antigen in the basement membrane.

Adolescent↗

PubMed1978

Ectopic liver.

Abnormally positioned liver tissue is rare but can occasionally cause clinical symptoms. The four main types are: 1. Accessory liver lobe that can reach a considerable size and is attached to the liver by a stalk. 2. Small accessory liver lobe which is attached to the liver but is usually small, about 10-30 g in weight. 3. Ectopic liver which is situated outside the liver without any connection with it. It is usually attached to the gallbladder or intra-abdominal ligaments. 4. Microscopic ectopic liver which is found occasionally in the wall of the gallbladder. The literature is reviewed and two cases of ectopic liver are described.

Adult↗