419 research outputs found
Muscle pathology in myotonic dystrophy: light and electron microscopic investigation in eighteen patients
Myotonic dystrophy (DM) is the most common muscular dystrophy in adults.
Two known genetic subtypes include DM1 (myotonic dystrophy type 1) and
DM2 (myotonic dystrophy type 2). Genetic testing is considered as the only
reliable diagnostic criterion in myotonic dystrophies. Relatively little is known
about DM1 and DM2 myopathology. Thus, the aim of our study was to characterise
light and electron microscopic features of DM1 and DM2 in patients with
genetically proven types of the disease. We studied 3 DM1 cases and 15 DM2
cases from which muscle biopsies were taken for diagnostic purposes during
the period from 1973 to 2006, before genetic testing became available at our
hospital. The DM1 group included 3 males (age at biopsy 15–19). The DM2
group included 15 patients (5 men and 10 women, age at biopsy 26–60). The
preferential type 1 fibre atrophy was seen in all three DM1 cases in light microscopy,
and substantial central nucleation was present in two biopsies.
Electron microscopy revealed central nuclei in all three examined muscle biopsies.
No other structural or degenerative changes were detected, probably due to the
young age of our patients. Central nucleation, prevalence of type 2 muscle fibres,
and the presence of pyknotic nuclear clumps were observed in DM2 patients in
light microscopy. Among the ultrastructural abnormalities observed in our DM2
group, the presence of internal nuclei, severely atrophied muscle fibres, and lipofuscin
accumulation were consistent findings. In addition, a variety of ultrastructural
abnormalities were identified by us in DM2. It appears that no single ultrastructural
abnormality is characteristic for the DM2 muscle pathology. It seems, however,
that certain constellations of morphological changes might be indicative of
certain types of myotonic dystrophy. (Folia Morphol 2011; 70, 2: 121–129
Evaluation of the urinary nuclear matrix protein (NMP22) as a tumour marker in bladder cancer patients
Studies of unicellular micro-organisms Saccharomyces cerevisiae by means of Positron Annihilation Lifetime Spectroscopy
Results of Positron Annihilation Lifetime Spectroscopy (PALS) and microscopic
studies on simple microorganisms: brewing yeasts are presented. Lifetime of
ortho - positronium (o-Ps) were found to change from 2.4 to 2.9 ns (longer
lived component) for lyophilised and aqueous yeasts, respectively. Also
hygroscopicity of yeasts in time was examined, allowing to check how water -
the main component of the cell - affects PALS parameters, thus lifetime of o-Ps
were found to change from 1.2 to 1.4 ns (shorter lived component) for the dried
yeasts. The time sufficient to hydrate the cells was found below 10 hours. In
the presence of liquid water an indication of reorganization of yeast in the
molecular scale was observed.
Microscopic images of the lyophilised, dried and wet yeasts with best
possible resolution were obtained using Inverted Microscopy (IM) and
Environmental Scanning Electron Microscopy (ESEM) methods. As a result visible
changes to the surface of the cell membrane were observed in ESEM images.Comment: Nukleonika (2015
Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector
In this paper we present prospects for using the J-PET detector to search for
discrete symmetries violations in a purely leptonic system of the positronium
atom. We discuss tests of CP and CPT symmetries by means of ortho-positronium
decays into three photons. No zero expectation values for chosen correlations
between ortho-positronium spin and momentum vectors of photons would imply the
existence of physics phenomena beyond the Standard Model. Previous measurements
resulted in violation amplitude parameters for CP and CPT symmetries consistent
with zero, with an uncertainty of about 10-3. The J-PET detector allows to
determine those values with better precision thanks to a unique time and
angular esolution combined with a high geometrical acceptance. Achieving the
aforementioned is possible due to application of polymer scintillators instead
of crystals as detectors of annihilation quanta.Comment: in Nukleonika 201
Beam profile investigation of the new collimator system for the J-PET detector
Jagiellonian Positron Emission Tomograph (J-PET) is a multi-purpose detector
which will be used for search for discrete symmetries violations in the decays
of positronium atoms and for investigations with positronium atoms in
life-sciences and medical diagnostics. In this article we present three methods
for determination of the beam profile of collimated annihilation gamma quanta.
Precise monitoring of this profile is essential for time and energy calibration
of the J-PET detector and for the determination of the library of model signals
used in the hit-time and hit-position reconstruction. We have we have shown
that usage of two lead bricks with dimensions of 5x10x20 cm^3 enables to form a
beam of annihilation quanta with Gaussian profile characterized by 1 mm FWHM.
Determination of this characteristic is essential for designing and
construction the collimator system for the 24-module J-PET prototype.
Simulations of the beam profile for different collimator dimensions were
performed. This allowed us to choose optimal collimation system in terms of the
beam profile parameters, dimensions and weight of the collimator taking into
account the design of the 24 module J-PET detector.Comment: 14 pages, 9 figure
PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix
The polystyrene dopped with 2,5-diphenyloxazole as a primary fluor and
2-(4-styrylphenyl)benzoxazole as a wavelength shifter, prepared as a plastic
scintillator was investigated using positronium probe in wide range of
temperatures from 123 to 423 K. Three structural transitions at 260 K, 283 K
and 370 K were found in the material. In the o-Ps intensity dependence on
temperature, the significant hysteresis is observed. Heated to 370 K, the
material exhibits the o-Ps intensity variations in time.Comment: in Nukleonika 201
Zmiany histopatologiczne w biopsji mięśnia u 31 chorych z mutacjami w genie kodującym kalpainę 3
Background and purpose
At present, more than 20 different forms of limb-girdle muscular dystrophies (LGMDs) are known (at least 7 autosomal dominant and 14 autosomal recessive). Although these different forms show some typical phenotypic characteristics, the existing clinical overlap makes their differential diagnosis difficult. Limb-girdle muscular dystrophy type 2 (LGMD2A) is the most prevalent LGMD in many European as well as Brazilian communities and is caused by mutations in the gene CAPN3. Laboratory testing, such as calpain immunohistochemistry and Western-blot analysis, is not totally reliable, since up to 20% of molecularly confirmed LGMD2A show normal content of calpain 3 and a third of LGMD2A biopsies have normal calpain 3 proteolytic activity in the muscle. Thus, genetic testing is considered as the only reliable diagnostic criterion in LGMD2A.
Material and methods
In an attempt to find a correlation between genotype and muscle pathology in limb-girdle muscular dystrophy 2A we performed histopathological investigation of a group of 31 patients subdivided according to the type of pathologic CAPN3 gene mutation.
Results
In all biopsies typical features of muscular dystrophy such as fiber necrosis and regeneration, variation in fiber size and fibrosis were noted. Lobulated fibers were often encountered in the muscle biopsies of LGMD2A patients. Such fibers were more frequent in patients with 550delA mutation.
Conclusions
These findings may be helpful in establishing diagnostic strategies in LGMD.Wstęp i cel pracy
Dotychczas opisano ponad 20 różnych form dystrofii obręczowo-kończynowej (limb girdle muscular dystrophy – LGMD) (co najmniej 7 rodzajów o dziedziczeniu autosomalnym dominującym oraz 14 o dziedziczeniu autosomalnym recesywnym). Pomimo że część z tych chorób można różnicować na podstawie obrazu klinicznego, diagnostykę utrudnia często podobieństwo objawów. Dystrofia obręczowo–kończynowa typu 2A (limb-girdle muscular dystrophy type 2 – LGMD2A), najczęstsza dystrofia mięśniowa w wielu społecznościach (np. w Europie i Brazylii), spowodowana jest przez mutacje w genie kalpainy 3 (CAPN3). Badanie immunohisto-chemiczne kalpainy czy też metodą Western blot nie są wystarczające do ustalenia właściwego rozpoznania (w odpowiednio 1/3 i 20% potwierdzonych genetycznie LGMD2A badania te wypadają prawidłowo). Podstawę rozpoznania tej miopatii stanowi badanie genetyczne.
Materiał i metody
W pracy przedstawiono wyniki badania zależności między genotypem a analizą histopatologiczną biopsji mięśnia u 31 chorych na LGMD2A. Chorzy podzieleni zostali na grupy według wyników badania genetycznego genu CAPN3 odpowiedzialnego za tę chorobę.
Wyniki
We wszystkich badanych biopsjach stwierdzano typowe zmiany dystroficzne, takie jak obecność włókien martwiczych i regenerujących, zróżnicowaną wielkość włókien oraz włóknienie. Włókna o nierównomiernym rozkładzie barwień na enzymy oddechowe (lobulated fibers) były często obserwowane w biopsjach chorych z LGMD2A. Tego typu włókna szczególnie często występowały u chorych z mutacją 550delA.
Wnioski
Wyniki pracy wnoszą nowe informacje ułatwiające diagnostykę LGMD
- …