Search PubMed⌕ Search

Biomedical subjects

A Penttila

Publications and source records attributed to A Penttila.

At least 19 recordsLinked to original sources
PubMed1997

Incidence of disorders of spermatogenesis in middle aged finnish men, 1981-91: two necropsy series.

OBJECTIVE: To investigate if the incidence of disorders of spermatogenesis and testicular tissue morphology have changed in middle aged Finnish men over 10 years. DESIGN: Two necropsy series completed in 1981 and in 1991. SETTING: Department of Forensic Medicine, University of Helsinki, Finland. SUBJECTS: 528 men, aged 35 to 69 years, subjected to medicolegal necropsy. MAIN OUTCOME MEASURES: Scoring of spermatogenesis and morphometric analysis of testicular tissue components. Individual risk factors for testicular disorders obtained by postmortem blind interviews with acquaintances. RESULTS: Normal spermatogenesis was found in 41.7% of the men (mean age 53.1 years). Between 1981 and 1991, the ratio of normal spermatogenesis decreased significantly (odds ratio 3.5; 95% confidence interval 2.5 to 5.1) from 56.4% to 26.9%, with a parallel increase in the incidence of partial and complete spermatogenic arrest (2.1; 1.4 to 2.9 and 2.9; 1.7 to 5.0, respectively). During this period, the size of seminiferous tubules decreased, the amount of fibrotic tissue increased, and the weight of testicles decreased significantly. Alterations in testicular characteristics over time could not be explained by changes in body mass index, smoking, alcohol drinking, or exposure to drugs. CONCLUSIONS: The incidence of normal spermatogenesis decreased among middle aged Finnish men from 1981 to 1991, and the incidence of disorders of spermatogenesis and pathological alterations in testicles increased. Deteriorating spermatogenesis may thus be one important factor in the explanation of declining sperm counts observed worldwide.

Adult↗
PubMed1997

Driver suicides.

BACKGROUND: To study driver suicides, all motor vehicle driver fatalities in Finland from 1987 to 1991 were analysed. METHOD: Cases were collected from all driver fatalities (n = 1419), as those that accident investigation teams considered possible suicides (n = 99). Drivers committing suicide classified according to ICD-9 by two forensic pathologists were selected as cases (n = 84). Drivers of unintentional motor vehicle fatalities served as the control group. RESULTS: While 5.9% of all driver fatalities were classified as suicides, the figure given in the official statistics was 2.6%. Driver suicides accounted for 1.2% of all suicides. Fifty per cent of driver suicides were committed by men aged between 15 and 34 years. The victims had often suffered from life-event stress, mental disorders and had alcohol misuse problems. The cases were usually head-on collisions between two vehicles with a large weight disparity. CONCLUSIONS: Misclassification of driver suicides does not significantly influence the total suicide rate. However, people who commit suicide by this method could often be recognised, and prevention of these events would improve traffic safety.

Accidents, Traffic↗
PubMed1995

Trends and availability of suicide methods in Finland. Proposals for restrictive measures.

BACKGROUND: Trends and availability of the methods used for suicide in Finland were analysed in order to base proposals for prevention of access to methods. METHODS: Finnish suicides from 1947 to 1990 were analysed by sex, age, time period and suicide method using confidence intervals for rates, chi 2 test for trends and suicide risks for different medicines. RESULTS: Suicide rate by parathion, a highly lethal pesticide and commonly used for suicide in the 1950s, decreased after its availability was restricted, but this was offset by an increased rate by other methods. Since 1982, the suicide risk for antidepressants and neuroleptics increased coincident with their availability, although that for barbiturates remained stable but high despite a reduction in availability. Suicide risk for antidepressants other than tricyclics decreased despite increased availability. CONCLUSION: Restriction of a method reduces its use for suicide, but other methods tend to replace it. Restrictive measures should focus on some specific situations. Antidepressants other than tricyclics are recommended for the treatment of suicidal depressive patients.

Adolescent↗
PubMed1988

Increased serum acetate as a marker of problem drinking among drunken drivers.

727 consecutive drunken drivers were studied for laboratory markers of excessive alcohol consumption. Serum gamma-glutamyltransferase and alanine aminotransferase showed no differences and aspartate aminotransferase and blood alcohol concentration only small differences between groups of first and repeating drunk driving offenders. The best laboratory test to differentiate the repeating offenders with probably more serious alcohol problems from the first offenders was in our material serum acetate, the mean serum acetate level of the repeating offenders being highly significantly (P less than 0.001) higher than that of the first offenders or nonalcoholic controls. Serum acetate also differentiated first offenders from nonalcoholic controls (P less than 0.001). Our results suggest that serum acetate could be used for the screening of problem drinking among drunken drivers.

Acetates↗
PubMed1987

Drinking and driving: choosing the legal limits.

The legal limit for drinking and driving in Britain is 80 mg/dl (17.4 mmol/l) of alcohol in the blood. This was chosen 20 years ago on the basis of studies that have recently been reanalysed. Changes in public opinion, the results of recent research, and the evaluation of other countermeasures, such as random breath testing, show that there are good grounds for revising the legal limit downwards. It is suggested that the legal limit should be reduced from 80 mg/dl to 50 mg/dl (10.9 mmol/l) and random breath testing introduced as in most Nordic countries. A zero limit is proposed for learner and first year drivers, who are likely to have accidents even with low concentrations of alcohol in their blood.

Accidents, Traffic↗
PubMed1987

Drinking and driving: success of random breath testing in Finland.

Since the introduction of random breath testing in Finland in 1977 the drinking and driving rate has halved, and there has been an appreciable reduction in the rates of death and injury from road accidents associated with drinking. The results of Finnish studies indicate that random breath testing deters social drinkers and detects problem drinkers. Problem drinkers are more likely to be driving in morning traffic, when vulnerable road users such as children are about, and are more likely to be detected by random breath testing than by any other police activity. Random breath testing is a popular measure and has not only saved lives but has paid for itself by savings in health service and other resources. Introducing random breath testing into Britain could save at least 400 lives a year. The main recommendation of the Blennerhassett report of 1976--discretionary testing--is compared with the success of random breath testing in Finland.

Accidents, Traffic↗
PubMed1979

Studies on cell surface conformation following injury. II. Scanning and transmission electron microscopy of cell surface changes following anoxic injury in Ehrlich ascites tumor cells.

Exposure of Ehrlich ascites tumor cells to anoxia resulted in rapid and characteristic conformational changes of cell surface topography. Combined scanning and transmission E/M studies revealed rapid alterations including simplification of the cell surface configuration with disappearance of microvilli which were replaced with formation of blebs and recesses at the cell periphery. These surface changes were accompanied by characteristic organelle alterations inside the cells which in this and other cellular systems have been shown to be reversible. Later, the cell surface topography became smoother and monotonic with small blebs and cribriform invaginations in addition to larger eruptions of the cell periphery. Combined transmission E/M studies revealed fragmentation of cellular membrane systems and lysis of organelles indicating the irreversible phase of anoxic injury. The rapid conformational surface changes encountered in Ehrlich ascites tumor cells following anoxia suggest the important role of the plasma membrane and its unfolding as a virtually instantaneous response of the cells to this injury.

Animals↗
PubMed1977

Optical properties of normal and injured cells. Application of cytographic analysis to cell viability and volume studies.

A cell spectrophotometer (Cytograf Model 6300 A, Bio/Physics Systems, Inc.) was tested in a cytotoxic assay using Ehrlich ascites tumor cells as a model system. Several cellular conditions associated with volume expansion, staining of cellular components and fixation of cells were applied and the magnitude of the scattering and extinction signals were tested in these diverse cellular conditions. The magnitude of the scattering pulse of a cell spectrophotometer was found to be greatly dependent on the staining color and intensity of cellular components with vital dyes or following osmium tetroxide fixation. When the absorption wavelength of the vital dye was close to the wavelength used in the cell spectrophotometer (about 630 nm), dead stained and living nonstained cell populations were completely separated from each other. The magnitude of the extinction pulse was greatly dependent on the state (normal, injured cells) and staining intensity (vital dye staining, osmium fixation) of cellular components. The magnitude of the extinction pulse was reduced from that in normal cells when cells were treated with p-chloromercuribenzene sulfonic acid or in a hypotonic solution that caused a marked volume expansion of injured cells. When cells were fixed with a mixture containing glutaraldehyde and osmium tetroxide the cellular components of normal and injured cells turned black and in these conditions the magnitude of the extinction signal was in a linear correlation to the cross-sectional area of cells. In the present study, the cell spectrophotometer proved to be an efficient method for estimation of cellular viability, based on different scattering properties of cells, offering the advantages of high speed and precision. Demonstration of the use of a variety of vital dyes having diverse extinction properties with capabilities to differentiate between living and dead cells has indicated the potential use of the cell spectrophotometer in cytotoxic assay. Modification of the magnitude of the extinction signal in the cell spectrophotometer also shows great promise for accurate automated size determination of both normal and injured cells. Previously, determination of the size of injured cells has been beset with methodologic errors.

4-Chloromercuribenzenesulfonate↗
PubMed1975

Studies on the modification of the cellular response to injury. II. Electron microscopic studies on the protective effect of acidosis on anoxic injury of Ehrlich ascites tumor cells.

Extracellular acidosis (ph 5.9 to 6.5) was found to be significantly retard the subcellular response of Ehrlich ascites tumor cells (EATC) to anoxic injury. The cells initially showed a reversible stage of cell injury with diffuse mitrochondrial condensation and swelling of endoplasmic reticulum (ER) at pH 7.9 by 1 h, while by 3 h at this pH all cells showed high amplitude and intramatrical flocculent densities of mitochondria, and fragmentation of membrane systems. At pH 7.4 cells were normal at 15 min., the mitochondria were condensed as above by 1 h, some cells still showed condensed mitochondria and dilated ER while others showed high amplitude swelling of mitochondria by 3 h and all cells showed irreversible changes by 4 h. At pH 5.9 to pH 6.5 mitochondria remained condensed until 3 h and only by 6 h did some cells show high amplitude swelling, whereas most cells showed persistent mitrochondrial condensation. Not until 8 h did all cells show high amplitude swelling of mitochondria. Furthermore, ultrastructural differences in the pattern of necrosis were seen at the lower pH values consisting of greater density of the cell sap, irregularly dispersed flocculent densities in apposition to fragmented cytoplasmic membranes and in mitochondria, and more prominent persistent clumping of nuclear chromatin.

Acidosis↗
PubMed1975

Effects of fixation and postfixation treatments on volume of injured cells;.

The effects of fixation with glutaraldehyde (GA), formaldehyde (FA), glutaraldehyde-formaldehyde (GA-FA), flutaraldehyde-osmium tetroxide (GA-Os04) and osmium tetroxide (OsO4) on cel volume were studied in control, p-chloromercuribenzene sulfonic acid (PCMBS)-treated and hypotonically-treated Ehrlich ascites tumor cells. Among the variables investigated were concentration of the tixative agent, osmolity of the buffer, total osmolaity of the fixation solution, osmolaltity of the postfixation buffer and the time of fixation and postfixation treatment; in addition, the effects of adding calcium and high molecular weight compounds to the fixative solution were studied. When the effects of standard fixatives on control, PCMBS- and hypotonically-treated cells were compared, marked differences were apparent in the behavior of control and injured cells. Control cells retained near prefixation volume in 3% GA and 3% GA-1% OsO4, swelled in 4% FA or 1% OsO4 and phosphate buffer (tkrp), whereas tpcmbs (310 mosM KRP)- and hypotonically-treated cells (103 mos M KRP) shrank in all aldehyde fixatives but swelled in 1% OsO4. Reducing the buffer osmolality had similar effects on control and injured cells although, there were variations in degree...

Animals↗
PubMed1975

Studies on the modification of the cellular response to injury. III. Electron microscopic studies on the protective effect of acidosis on p-chloromercuribenzene sulfonic acid-(PCMBS) induced injury of Ehrlich ascites tumor cells.

Extracellular acidosis (pH 6.5) was found to significantly retard the response of Ehrlich ascites tumor cells (EATC) to direct plasma membrane injury with the non-penetrating organic mercurial compound, p-chloromercuribenzene sulfonic acid (PCMBS). Treatment of cells with 1 mM PCMBS resulted in loss of viability of all cells by 45 minutes at pH 7.4, and by 90 minutes at pH 6.5. Pregression of cellular changes through the various stages of cell injury at the ultrastructural level was correspondingly slower at pH 6.5. The results support the concept that stage 3 of cell injury, associated with condensed mitochondria, dilated ER and swollen cell sap is compatible with cell survival, while stage 5 with high amplitude swelling of mitochondria, fragmentation of membrane systems, and beginning of karyolysis is characteristic of irreversible injury. All cells entered stage 3 at 7.5 minutes at pH 7.4, while essentially all cells entered stage 5 by 45 minutes. At pH 6.5, stage 3 was maintained for 45 minutes and 100% of the cells entered stage 5 by 90 minutes. Although the mechanism of the protection against PCMBS-induced injury is not known, the present electron microscopical results are compatible with the hypothesis that the extracellular acidosis acts to partially stabilize plasma membrane, perhaps by interaction with sulfhydryl (SH) groups.

Acidosis↗
PubMed1975

Studies on modification on the cellular response to injury.

Extracellular acidosis (pH 6.6) has been found to delay the lethal effect of p-chloromercuribenzene sulfonic acid on Ehrlich ascites tumor cells. At pH 6.6, 50 per cent of the cells died within approximately 80 minutes, compared with approximately 10 minutes at pH 7.5 or approximately 5 minutes at pH 8.0. It was also observed that low pH produced a dissociation between potassium loss, ATP levels, cell volume, and cell death. The possible mechanism of this effect is discussed; it is our hypothesis that it involves proton interactions with plasma membrane components which either affect available membrane sulfhydryl groups or otherwise stabilize the cell membrane against loss of semipermeable characteristics and cellular lysis.

4-Chloromercuribenzenesulfonate↗
PubMed1974

Extracellular acidosis protects Ehrlich ascites tumor cells and rat renal cortex against anoxic injury.

The present study indicates that extracellular acidosis protects Ehrlich ascites tumor cells and rat kidney cortex cells against injury from anoxia. Parameters measured included cell potassium, adenosine 5'-triphosphate, and uptake of vital dyes. Cells survived longer at a pH of 5.6 to 6.5 than at a pH of 7.4; pH 7.9 was most detrimental. These findings indicate that production of protons by anoxic cells may be a protective feedback mechanism.

Anaerobiosis↗