Methionine adenosyltransferase activity in cultured cells and in human tissues.

We have investigated methionine adenosyltransferase activity (MAT) in extracts of a variety of normal and malignant human tissues and cultured cell lines. MAT activity assayed from 17 different cultured cell lines varied to a great extent. Ramos (human, Burkitt's lymphoma) and EL4 (mouse, T cell lymphoma) cells showed MAT activity near 300 pmol/mg per min. Daudi (human, Burkitt's lymphoma) and almost all monolayer cells had MAT activity below 100 pmol/mg per min. Human peripheral blood lymphocytes had MAT activity of 36 pmol/mg per min. The MAT activity of the cell lines can be related to doubling time: cell lines with short doubling times have much higher MAT activity than other cell lines. A large variation in MAT activity in different human tissues was observed. In autopsy samples MAT activity was highest in the brain and in the colon. Malignant tissue samples gave much higher MAT activity than normal tissues. Lung cancer (carcinoma squamocellulare pulmonis) had MAT activity of 30.7 pmol/mg per min, while in normal lung it was 2.4 pmol/mg per min.

Distribution of parvalbumin-immunoreactive cells and fibers in the human amygdaloid complex.

The calcium-binding protein, parvalbumin, was localized immunohistochemically in the human amygdaloid complex. Neuronal cell bodies and fibers that are immunoreactive to parvalbumin were observed in most of the amygdaloid nuclei and cortical areas. Three types of immunoreactive aspiny neurons, ranging from small spherical cells (type 1) to large multipolar cells (type 2) and fusiform cells (type 3), were observed. The densities of the types of neurons that were parvalbumin-immunoreactive varied in the different regions of the amygdala. The highest densities of parvalbumin-immunoreactive neurons were observed in the lateral nucleus, in the magnocellular and intermediate divisions of the basal nucleus, in the magnocellular division of the accessory basal nucleus and in the amygdalohippocampal area. The regions containing the lowest density of parvalbumin-immunoreactive cells were the paralaminar nucleus, the parvicellular division of the basal nucleus, the central nucleus, the medial nucleus and the anterior cortical nucleus. In general, the distribution of immunoreactive fibers and terminals paralleled that of immunoreactive cells. Parvalbumin-immunoreactive varicose fibers formed basket-like plexi and cartridges around the unstained neurons, which suggests that parvalbumin is located in GABAergic basket cells and chandelier cells, respectively. The distribution of parvalbumin-immunoreactive profiles in the human amygdaloid complex was similar to, rather than different from that previously reported in the monkey amygdala (Pitkänen and Amaral [1993] J. Comp. Neurol. 331:14-36). This study provides baseline information about the organization of GABAergic inhibitory circuitries in the human amygdaloid complex.

Comparison of different ways of presenting the results of biochemical analyses of human coronary arteries.

Three methods of expressing the results of biochemical analyses of normal and atherosclerotic human coronary intima-medias were compared by calculating the results per unit area of vessel surface to obtain the content, per unit weight of dry defatted tissue (d.t.) to obtain the concentration, and per unit weight of organic d.t. to obtain the inorganic salt-corrected concentration. The content reflects the amount of a substance in an anatomically defined portion of the arterial wall, whereas the concentration gives the amount of the substance relative to a defined mass of arterial tissue. Since calcium salts form a sizable portion of fibrous plaques, concentrations become overcorrected in the oldest age groups. For example, there was an unexpected age-related decrease of collagen concentration in fibrous plaques-containing coronary arteries while its content and inorganic salt-corrected concentration increased. In studies involving arterial biochemical analyses it is appropriate to calculate the results in terms of both the content and the concentration. If severely affected specimens are studied, it is recommendable also to use the inorganic salt-corrected concentration, especially when different age groups are compared with one another.

Atherosclerosis and biochemical composition of coronary arteries in Finnish men. Comparison of two populations with different incidences of coronary heart disease.

Men in Eastern Finland show a substantially higher rate of coronary heart disease (CHD) than men in the Western part of the country. To study possible differences in the biochemical composition and atherosclerotic involvement of coronary arteries between these two populations, we analyzed major lipid and non-lipid components of coronary arteries from 15- to 60-year-old Finnish men after accidental death. The material consisted of 59 age-matched pairs from East and West Finland, respectively, collected at successive autopsies during 1979-1983. The coronary arteries from East Finland contained significantly more esterified cholesterol and a higher percentage of oleate in cholesteryl esters. The findings were most conspicuous under the age of 40 years, and imply a higher degree of atherosclerosis together with an increased rate of intracellular cholesterol esterification in coronary arteries in Eastern as compared with Western Finland. The vessels from East Finland also tended to contain more free cholesterol and raised lesions, but the differences were not statistically significant. No major regional differences were seen in total phospholipids, phospholipid subfractions, DNA, calcium, collagen, total protein, or glycosaminoglycans.

Macrophages, smooth muscle cells, endothelial cells, and T-cells express CD40 and CD40L in fatty streaks and more advanced human atherosclerotic lesions. Colocalization with epitopes of oxidized low-density lipoprotein, scavenger receptor, and CD16 (Fc gammaRIII).

CD40-CD40L receptor-ligand interaction plays a central role in antigen presentation, immunological reactions, and in T-cell and macrophage activation. Since all these mechanisms are important for the pathogenesis of atherosclerosis, we studied the expression profile of CD40-CD40L in different types of human atherosclerotic lesions using double immunostaining techniques with cell type-specific antibodies. Normal human intima did not contain CD40 or CD40L immunoreactivity. From type-II lesions (fatty streaks) to advanced type-VI lesions (complicated plaques), colocalization of CD40 and CD40L was observed in T cells (CD3+ cells), macrophages (CD68+ cells), and smooth muscle cells (HHF35+ cells). No correlation was found between the lesion type and CD40-CD40L expression. Positive lesions had dense infiltrations of macrophages and macrophage-derived foam cells together with T cells. The most intensive immunoreactivity for the CD40 receptor and its ligand CD40L was found in macrophage- and T-cell-rich pockets, where both cell types were in close contact with each other. The majority of macrophages, and especially those of macrophage-derived foam cells, were positive for both CD40 and CD40L. A small subset of the lesion macrophage population (10-20%) consisted of cells positive only for either CD40 or CD40L, suggesting the presence of a subpopulation of macrophages more active in inflammatory processes than in lipid uptake. Intimal smooth muscle cells in and around the macrophage-rich areas as well as some of the medial smooth muscle cells near the lesions stained positive for CD40 and CD40L. Moderate to faint expression of these proteins was also found in endothelium. In addition, CD40-CD40L immunoreactivity colocalized with epitopes characteristic of oxidized low-density lipoprotein, scavenger receptor class A, and CD16 (Fc gammaRIII), thus suggesting the involvement of CD40-CD40L and these pathogenetic mediators in foam cell formation, progression of atherosclerotic lesions, and differentiation of immunologically active subsets of macrophages. These results support the hypothesis that CD40-CD40L interaction is involved in atherogenesis and that it might provide a target for future therapeutic interventions.

Calretinin-immunoreactive terminals make synapses on calbindin D28k-immunoreactive neurons in the lateral nucleus of the human amygdala.

A double-labeling immunohistochemical procedure and correlated light and electron microscopy were used to examine if calretinin-immunoreactive terminals make synapses on calbindin D28k-positive cells. In the lateral nucleus of the human amygdala, calretinin terminals make symmetric-like synapses on the somata and proximal dendrites of calbindin D28k-labeled cells. Our data provide the first evidence that neurons which contain two different calcium-binding proteins form synaptic contacts with each other in the human amygdala.

Biochemical and histochemical evaluation of tryptase in various human tissues.

The distribution of tryptase in various human tissue high-salt extracts (skin, lung, pancreas, liver, kidney, and spleen) was studied. Tryptase activity was compared with tissue histamine concentration, chymase activity, and cathepsin D, and histamine-N-methyltransferase (HMT) activities. Tryptase activity, found biochemically in tissue extracts, was localized in tissue sections by an enzyme-histochemical method using peptide 4-methoxy-2-naphthylamide substrates and Fast Garnet GBC as the chromogen. The highest levels of tryptase activity were found in lung and skin extracts. Liver, kidney, and spleen extracts displayed only a little activity. The distribution of histamine was similar to that of tryptase, whereas distributions of cathepsin D and HMT were quite different from that of tryptase. High-salt extracts of lung contained no detectable chymase activity, but in skin extracts this activity was high. Using an enzyme-histochemical method, the tryptase activity in tissue sections seemed solely to be confined to cells, which were granular and Giemsa positive after the red azo dye had been removed with Tween 20. Skin and lung sections contained the highest number of positively stained cells. The inhibition properties of tryptase, found in both tissue extracts and sections, and the substrate profile in tissue sections were identical. Human leukocyte preparation was negative for tryptase when stained enzyme-histochemically. The present results suggest that tryptase in human tissues is found only in the mast cells. The enzyme seems to be identical in the various human tissues studied because the different high-salt extracts were immunologically cross-reactive when tested with a rabbit polyclonal antibody against skin tryptase.

The role of the forensic pathologist in the investigation of fatal traffic accidents--the Finnish system.

In Finland about one-half of the fatal traffic accidents are investigated by special Boards of Inquiry. The cumulating data serves multidisciplinary sciences, juridical and insurance purposes and legislation. The participating physicians benefit from the systematic work of the Boards in many ways. As an example of the results a list of causes of accidents is shown.

Intra-familial child homicide in Finland 1970-1994: incidence, causes of death and demographic characteristics.

The purpose of this study was to investigate all child homicides for the 25-year period, 1970-1994 in Finland and to analyse the specific characteristics of the filicide cases. A total of 292 child homicides occurred during this period. In 201 (69%) cases the offender was a parent or a stepparent of the child. Altogether, 173 (59%) of the victims were boys and 119 (41%) were girls. For the closer examination of the filicide cases we excluded the neonaticide and homicide-suicide cases. Consequently, we report on 70 filicide victims. Of these victims, 42 (60%) were boys and 28 (40%) were girls. Twenty six (37%) of the children were killed before the age of 1 year and 53 (79%) before the age of 5 years. The offender was the mother in 43 (61%) cases and the father or the stepfather in 26 (37%) cases. The victims of the mothers were younger than those of the fathers. The most frequent causes of death were head injuries, drowning and suffocation. The most common means of assault were battering, drowning and strangulation. One in two of the fatally battered children had a documented history of previous abuse.

Forensic osteological investigations in Kosovo.

A team of Finnish forensic experts performed investigations of alleged mass graves in Kosovo under the mandate of the European Union (EU). Human skeletal remains from two locations were examined. The remains contained three almost complete skeletons, and individual bones and bone fragments, part of which were burned. Injuries, pathological changes, and findings for identification purposes were examined and documented using standard methods of forensic pathology and osteology. Gunshot injuries were found in some cases, but reliable determination of the cause and manner of death was not possible. A discrepancy arose between the number of victims reported in information received from the presiding district court, and results of the investigations. The estimation of the minimum number of victims was mostly acquired by DNA analysis.

Forensic investigations in Kosovo: experiences of the European Union Forensic Expert Team.

The international community has intervened ethnic hostilities in Kosovo, the Federal Republic of Yugoslavia. A team of Finnish forensic experts worked in December 1998 and January 1999 in Kosovo under the mandate of the European Union. The team investigated human remains from three locations of alleged ethnic violence. Concerning the events in Klecka, Volujak and Racak, the International Criminal Tribunal for the former Yugoslavia received documents of great gravity. The standard methods of forensic pathology were complemented with radiological, forensic odontological, physical anthropological and molecular genetic investigations.