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M Nykänen

Publications and source records attributed to M Nykänen.

11 recordsLinked to original sources
PubMed2005

Localization of M2 muscarinic receptor protein in parvalbumin and calretinin containing cells of the adult rat entorhinal cortex using two complementary methods.

We investigated parvalbumin (PV) and calretinin (CR) containing interneurons in the rat entorhinal cortex. RNA amplification following single cell dissection of immunohistochemically labeled cells from layers II to VI revealed that PV cells, in contrast to CR cells, express the m2 muscarinic receptor (M2AchR) protein. Double immunostaining to confirm the results of RNA amplification indicated that the majority of PV cells contain M2AchR protein, whereas only a small proportion of CR cells do. In contrast, a large number of layer I CR cells, which are mostly Cajal-Retzius cells, were positive for M2AchR. RNA amplification following dissection of these cells also revealed that they contain the M2AchR protein. These findings emphasize that there are significant differences in the expression of different proteins, even among similar neuronal types in the same brain region. This highlights the importance of accurately collecting single cells, and knowledge of anatomical details in molecular biological studies.

Animals↗
PubMed2004

Predicting aggressive outcome in T1N0M0 breast cancer.

Despite the excellent overall prognosis, unpredictable breast cancer recurrences and deaths also occur among T1N0M0 patients. We have evaluated clinically applicable methods for identifying aggressive outcome in T1N0M0 breast cancer. The material is based on aggressive T1N0M0 invasive ductal and lobular carcinomas diagnosed in Turku University Hospital and Jyväskylä Central Hospital, Finland, during 1987-1997. We studied all the T1N0M0 breast cancers that had led to recurrency or death (n=21, 95% T1cN0M0) during the follow-up period (4-14 years). The study is based on statistical analyses of matched case-control data in which the prognostic factors of each individual patient with aggressive disease were compared with control patients (n=45) individually matched by tumour size, age at diagnosis, histological type of tumour and length of follow-up. The cancer cases were examined for clinically applicable conventional and immunohistochemical pathologic prognostic factors. High Ki-67 immunopositivity was the strongest prognosticator of breast cancer death or recurrence in T1N0M0 breast cancer. Also, high p53 immunopositivity, low oestrogen receptor immunopositivity and Her-2/neu oncogene amplification by chromogen in situ hybridisation were reliable indicators of unfavourable outcome. Our statistical methods also allowed us to determine for the present material a range of clinical significance for each immunohistochemical prognostic feature with the associated relative risk for breast cancer death and recurrence. The paper suggests guidelines for predicting aggressive outcome in T1N0M0 breast cancer.

Adult↗
PubMed1998

Purification of filaggrin from human epidermis and measurement of antifilaggrin autoantibodies in sera from patients with rheumatoid arthritis by an enzyme-linked immunosorbent assay.

BACKGROUND: The so-called antikeratin antibody (AKA) and the antiperinuclear factor (APF) that recognize proteins related to human epidermal filaggrin belong to the most specific serological markers of rheumatoid arthritis (RA). However, assays for the detection of AKA and APF are currently based on immunofluorescence, a method that is subject to arbitrary interpretation and inadequate standardization of the substrates. METHODS: Proteins extracted from human epidermis were separated by reversed-phase high-performance liquid chromatography (HPLC). Filaggrin-containing fractions, identified in immunoblotting by monoclonal antifilaggrin antibodies, were then subjected to gel filtration HPLC and, finally, to a second reversed-phase HPLC step. Tryptic digestion, amino acid sequencing and mass spectrometry were used to confirm the identity of the purified protein. Filaggrin was used as antigen in enzyme-linked immunosorbent assay (ELISA) to measure IgG class antifilaggrin antibodies. RESULTS: The filaggrin preparation obtained gave a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, binding monoclonal antifilaggrin antibody in immunoblotting. Amino acid sequences of all 10 tryptic peptides analyzed were shown to originate from human filaggrin. Antifilaggrin antibody levels exceeded the 99th percentile level of 100 middle-aged blood donors in 26/55 (47%) RA sera. At a similar cutoff level 28/55 (51%) of the RA sera were positive in the AKA test. Of the 26 antifilaggrin-positive sera, 21 were also AKA-positive. CONCLUSION: Human filaggrin can be purified by standard biochemical techniques, despite the heterogeneity of the protein, and used in ELISA for testing autoantibodies to filaggrin. The sensitivity of the assay equals that of the AKA test.

Adult↗
PubMed1996

In vitro establishment of lytic and nonproductive infection by herpes simplex virus type 1 in three-dimensional keratinocyte culture.

The F strain of herpes simplex virus type 1 (HSV-1) was tested for its ability to produce lytic or nonproductive infection in squamous epithelial cells cultured in a three-dimensional organotypic tissue culture. For the tissue culture, we used HaCat cells (immortalized skin keratinocytes) and normal fibroblasts derived from the skin. The cultures were infected with HSV-1 (5 PFU) either when the epithelial cells had grown as a monolayer with a confluence of 80% on the collagen fibroblast gel or 30 min after lifting of the epithelial cells into the air-liquid interface. The cultures were collected 1 week after inoculation. Typical cytopathic effects of HSV infection (ballooning and reticular degeneration with multinucleate giant cells) were seen only in those cultures in which the epithelial cells were infected before lifting. The presence of HSV was confirmed by DNA and RNA in situ hybridization and PCR. No morphological changes were found in cultures infected after lifting into the air-liquid interface. No infectious virus was recovered either from cells or culture supernatant. However, these cultures were positive for HSV DNA on PCR and showed expression of the LAT gene by in situ hybridization and Northern blot (RNA) hybridization. The present results indicate that both nonproductive and lytic HSV infection can be produced in vitro and the outcome of the infection depends on the time of viral inoculation in relation to epithelial maturation.

Animals↗
PubMed1995

Pulsed ultrasound treatment of the painful shoulder a randomized, double-blind, placebo-controlled study.

To study the effect of pulsed ultrasound in shoulder pains, 35 patients were treated with pulsed ultrasound and 37 patients with placebo ultrasound in a double-blind design. The therapy was given during inpatient rehabilitation, 10-12 treatments over 3-4 weeks. Treatment time was 10 minutes, frequency 1.0mHz, on-off ratio 1:4 and intensity 1.0w/cm2. Follow-ups were done after 4-12 months. No differences (p < 0.05) in outcomes were found between the groups after the treatment period or at follow-ups. These results discourage the adding of pulsed ultrasound therapy with the variables used to the conservative treatment of the painful shoulder.

Adult↗
PubMed1993

Improved immunoturbidimetric method for rheumatoid factor testing.

The performance of two immunoturbidimetric modifications for rheumatoid factor (RF) testing, which differ with respect to the means of complement inactivation (heat treatment and inactivation with polyvinyl sulphonate), were compared in serum samples from 87 patients with rheumatoid arthritis (RA) and from 403 healthy subjects. IgM-rheumatoid factor titres were also measured with an enzyme linked immunosorbent assay (ELISA). Both immunoturbidimetric tests gave positive reactions (rheumatoid factor > or = 20 IU/ml) in 74 out of the 87 (85%) RA sera. In cases with high RF concentrations the results after chemical inactivation tended to be slightly higher compared with heat inactivation. In healthy subjects rheumatoid factor was detected in 19/403 (4.7%) sera using heat inactivation and in 22/403 (5.5%) sera with chemical inactivation of complement. Interrun coefficient of variation in the chemical inactivation assay was 4.4%; with the heat inactivation method it was 8.1%. In the ELISA, a marginally better correlation was noted in the results obtained using chemical inactivation. Inactivation of complement by means of polyvinyl sulphonate offers the advantage of easier test performance and better reproducibility, and the results may reflect more accurately true rheumatoid factor concentrations.

Adult↗
PubMed1980

Loose connective tissue of rat rete testis. Fine structure, postnatal development and effect of efferent duct ligation.

Fine structure, postnatal development and reaction to efferent duct ligation of the loose connective tissue of the rat rete testis were studied by light and electron microscopy. The loose connective tissue of adult rats consists of elongate fibroblasts in a homogenous ground substance, together with some Leydig cells, lymphocytes, macrophages and mast cells. During postnatal development this tissue increases in amount, while the interstitial areolar tissue decreases. The "looseness" of the tissue becomes more evident between days 22 and 27, and may reflect an increase in hydration. Efferent duct ligation for 15 min to five days has no effect on the histological appearance of the tissue.

Animals↗
PubMed1980

Morphology of the rat rete testis in experimental autoimmune orchitis.

The role of the rete testis and related structures in the development of experimental autoimmune orchitis (EAO) was studied in adult inbred Sprague-Dawley rats. Histology and electron microscopy showed focal perivascular infiltration and an increase in the number of mast cells and polymorphonuclears. Often there were vacuolated macrophages. These changes were first observed two weeks after the beginning of immunization, but they did not clearly precede lesions in seminiferous tubules. Increased amounts of cellular debris appeared in rete cavities, suggesting damage to germinal epithelium. Lanthanum tracer studies of immunized rats showed local lesions in the blood-testis barrier of the seminiferous tubules but did not indicate spreading of lesions from the rete testis. Efferent duct ligation of immunized rats for 24 h did not increase the frequency of lesions. The present observation do not support the theory that the rete testis is the route of spreading of EAO.

Animals↗
PubMed1980

On the microscopic anatomy of the rete testis a scanning electron microscopic and light microscopic study.

The microscopic anatomy of the transitional zone of the seminiferous tubules, the tubuli recti and the rete testis in adult rats was studied with histological serial sections, semithin sections and scanning electron microscopy. In paraffin section most transitional zones of the seminiferous tubules seemed to be obliterated by the modified Sertoli cells. Thinner plastic sections showed always a lumen, however. PAS--positive material, thought to represent masses of degenerating spermatozoa surrounded by Sertoli cell nuclei was found in 20% of transitional zones. About 80% of the tubuli recti had an initial widening which surrounded the bulging Sertoli cell bodies of the transitional zones. The intratunical rete consisted of five to seven intercommunicating channels, usually of small caliber. One wide communication was regularly present, however. The extratesticular rete was usually formed of two wide cavities. From their subdivisions the five to seven ductuli efferentes arose. The rete epithelium varied from very thin squamous to cuboidal and even columnar. The epithelial cells contained a flagellum surrounded by peripheral microvilli. Loose connective tissue was found under the epithelium of all parts of the rete.

Animals↗
PubMed1979

Fine structure of the transitional zone of the rat seminiferous tubule.

An electron microscopic study was made on the structure of the testicular transitional zone (TZ) in the adult rat. The TZ proper consists of modified Sertoli cellss, with only a few spermatogonia and macrophages, surrounding distally a very narrow lumen. The TZ Sertoli cells have nuclei with a somewhat coarser matrix and more peripheral heterochromatin than Sertoli cell nuclei of the nearby seminiferous tubules, and the electron density of the cytoplasm varies from cell to cell. Smooth endoplasmic reticulum is abundant, but usually there are also scattered ribosomal rosettes and an occasional profile of rough endoplasmic reticulum. Microtubules are very numerous in the columnar portion of the cell, and laminar structures seemingly joining the cell surfaces are sometimes seen. Lipid droplets and lysosmal structures are frequent cellular components in proximal TZ Sertoli cells. Empty intracellular vacuoles are abundant, sometimes arranged around areas of smooth endoplasmic reticulum. Occasionally, membrane-limited fine granules and vacuoles are seen within Sertoli cells and also in the TZ lumen, suggesting a possible secretory activity by these cells. The apical processes of the Sertoli cells form large vacuolar structures, and in the basal parts of the epithelium vacuoles with capillary-like appearance are frequently seen. Phagocytosis of germinal cells by the Sertoli cells occurs in the proximal region of the TZ. Round waste bodies in contact with the Sertoli cell apices protruding into the tubulus rectus, are also common. The tunica propria of the TZ is thickened and somewhat wrinkled, and in the proximal region the myoid cell layer loses its continuity and is replaced by fibroblasts. The epithelium of the tubulus rectus adjacent to the TZ consists of several overlapping epithelial cells. The typical junctional complexes between TZ Sertoli cells appear to be impermeable to the lanthanum tracer.

Animals↗