330 research outputs found
Limiting distribution and error terms for the number of visits to balls in non-uniformly hyperbolic dynamical systems
We show that for systems that allow a Young tower construction with
polynomially decaying correlations the return times to metric balls are in the
limit Poisson distributed. We also provide error terms which are powers of
logarithm of the radius. In order to get those uniform rates of convergence the
balls centres have to avoid a set whose size is estimated to be of similar
order. This result can be applied to non-uniformly hyperbolic maps and to any
invariant measure that satisfies a weak regularity condition. In particular it
shows that the return times to balls is Poissonian for SRB measures on
attractors.Comment: 28 page
Sperm DNA damage in relation to lipid peroxidation following freezing-thawing of boar semen
This study investigated the relationships between lipid peroxidation (LPO) and sperm DNA damage following freezing-thawing of boar semen in different extenders. The comet assay was used to measure the extent of sperm DNA damage in a cryoprotectant-free extender or in cryoprotectant-based extenders after single and repeated freezing and thawing. As well as an analysis of sperm motion characteristics, mitochondrial function, membrane integrity, and lipid peroxidation (LPO) were assessed simultaneously with the measurements of sperm DNA damage. Consistent positive significant correlations were found between sperm DNA damage and LPO after freezing-thawing. Comet assay measurements showed that cryo-induced sperm DNA damage was more marked in the cryoprotectant-free extender, irrespective of freezing cycle. The frequency of sperm cells with damaged DNA increased with repeated freezing and thawing in the cryoprotectant-based extenders. Except for sperm DNA damage, there were no consistent associations between post-thaw sperm LPO and sperm quality characteristics. It could be suggested that the increased LPO of membrane phospholipids is associated with higher susceptibility of boar spermatozoa to cryo-induced DNA damage.Keywords: Comet assay measurements, cryopreservation, extenders, spermatozo
The influence of detemir - a long acting analogue of insulin - on the metabolic homeostasis of diabetic patients. Observational study
WSTĘP. Celem niniejszej pracy była ocena wyrównania
metabolicznego u chorych na cukrzycę typu 1 i typu 2,
leczonych intensywną insulinoterapią, z zastosowaniem
długodziałającego analogu insuliny detemir.
MATERIAŁ I METODY. Do badania zakwalifikowano
17 chorych na cukrzycę typu 1 i 11 chorych na cukrzycę
typu 2, u których podstawowym leczeniem
była dotychczas intensywna insulinoterapia, oparta
głównie na insulinie NPH w skojarzeniu z szybkodziałającymi
analogami insuliny (86%). W ramach
intensyfikacji leczenia insulinę podstawową zastąpiono
insuliną detemir. Po obserwacji trwającej 3-6
miesięcy oceniano wpływ zmiany terapii na glikemię
na czczo, glikemię poposiłkową, stężenie HbA1c,
incydenty hipoglikemii, masę ciała. Do oceny statystycznej
używano testu McNemary (p*) oraz testu T
dla prób powiązanych (p**).
WYNIKI. Oceniając glikemię na czczo w całej badanej
grupie chorych na cukrzycę typu 1 i typu 2, u 36%
uzyskano znamienną statystycznie (p* < 0,013) znaczącą
poprawę stężenia glukozy na czczo. Wiązało
się to z 25-procentowym (p* < 0,039) zwiększeniem
stabilności glikemii na czczo. Zastosowanie analogu
długodziałającego detemir jako insuliny stanowiącej
bazę łącznie z analogami szybkodziałającymi (86%) w ramach intensywnej insulinoterapii przyczyniło
się do wzrostu o 32% (p* < 0,039) liczby chorych
z prawidłową glikemią poposiłkową. Skutkiem
lepszego wyrównania metabolicznego cukrzycy
w całej badanej grupie było znamienne statystycznie
obniżenie o 1,7% (p** < 0,001) stężenia HbA1c.
Zastosowanie insuliny detemir doprowadziło do
17-procentowej redukcji odsetka chorych z incydentami
hipoglikemii, w tym również epizodami hipoglikemii
nocnych. U prawie 1/3 pacjentów zarówno
z cukrzycą typu 1, jak i typu 2 doszło do zmniejszenia
masy ciała.
WNIOSKI. W wyniku zastosowania długodziałającego
analogu insuliny detemir uzyskano poprawę wyrównania
metabolicznego cukrzycy wyrażającą się:
obniżeniem glikemii na czczo i normalizacją glikemii
poposiłkowych, obniżeniem stężenia HbA1c,
zmniejszeniem częstości incydentów hipoglikemii,
a także redukcją masy ciała.BACKGROUND. The aim of this work is to estimate
the metabolic homeostasis in cases of type 1 and
type 2 diabetes, treated with intensive insulinotherapy,
with the use of detemir - a long acting analogue
of insulin.
MATERIAL AND METHODS. The research included 17
patients with type 1 diabetes and 11 patients with
type 2 diabetes. These patients were so far treated with intensive insulinotherapy, using NPH insulin and
short acting analogues of insulin (86%). In order to
intensify the treatment basic insulin was supplanted
with detemir insulin. After 3-6 months of observation
the influence of the change in therapy was
evaluated. The evaluation included fasting plasma
glucose concentration, post-prandial glucose concentration,
HbA1c concentration, number of hypoglycemia
incidences, body weight. The statistic assessment
was performed with the use of the McNemara test
(p*) and the T test for associated samples (p**).
RESULTS. In the group, 36% of case showed a statistically
significant (p* < 0.013) decrease in FPG followed
by a 25% (p < 0.039) improvement in FPG
stability. Using detemir as the basic insulin together
with short acting analogues (86%) in intensive insulinotherapy,
caused a 32% (p* < 0.039) increase in
the number of patients with normal post-prandial
glucouse concentration. Resulting from better metabolic
homeostasis in the whole research group,
there was a statistically significant decrease of HbA1c
by 1.7% (p** < 0.001). The use of detemir led to
a 17% reduction in the number of hypoglycemia incidences,
including night hypoglycemia. One third of
patients in the whole group reduced body weight.
CONCLUSIONS. The use of detemir led to an improvment
in metabolic homeostasis, manifesting in:
decrese in FPG and regulation of post-prandial glycemia,
lower HbA1c concentration, lower of hypoglycemia
incidences and decrease in body weight
The neuronal structure of the preoptic area in the mole and the rabbit: Golgi and Nissl studies
The present studies were carried out on the brains of the adult mole and rabbit.
The preparations were made by means of the Golgi technique and the Nissl
method. Two types of neurons were distinguished in the preoptic area (POA) of
both species: bipolar and multipolar. The bipolar neurons have oval, fusiform or
round perikarya and two dendritic trunks arising from the opposite poles of the
cell body. The dendrites bifurcate once or twice. The dendritic branches have
swellings, single spine-like and filiform processes. The multipolar neurons usually
have triangular and quadrangular perikarya and from 3 to 5 dendritic trunks.
The dendrites of the mole neurons branch sparsely, whereas the dendrites of
the rabbit neurons display 2 or 3 divisions. On the dendritic branches varicosities
and different protuberances were observed. The general morphology of the
bipolar and multipolar neurons is similar in the mammals studied, although the
neurons of the rabbit POA display a more complicated structure. Their dendritic
branches show more divisions and possess more swellings and different processes
than the dendrites of the neurons of the mole POA. Furthermore, of the
multipolar neurons only the dendrites in POA of the rabbit were observed to
have a rosary-like beaded appearance
A morphometric comparative study of the lateral geniculate body in selected placental mammals: the common shrew, the bank vole, the rabbit, and the fox
The lateral geniculate body (LGN) was morphometrically examined and compared
in representatives of four mammalian orders (Insectivora, Rodentia, Lagomorpha,
and Carnivora). In each studied species, the lateral geniculate body
was divided into two distinct parts: the dorsal nucleus (LGNd) and the ventral
nucleus (LGNv). The lateral geniculate body of the common shrew and the
bank vole are very similar in appearance and nuclear pattern. The dorsal and
ventral nuclei of these two species also have the most similar statistical characteristics.
The lateral geniculate body of the fox has the most complicated morphology
and multilayered structure. A significant disproportion was observed
between the sizes of both geniculate nuclei in the fox, where the dorsal nucleus
definitely surpassed the ventral nucleus in terms of volume. With the exception
of the fox, the neuronal density of the LGN nuclei was negatively correlated
with the volumes of the LGN. The mean neuronal size of the LGNd and
LGNv, which was the resultant of the length, width, area, and circumference
of the soma, grew correlatively to the volumes of these nuclei. In all examined
species, somas of the LGNd neurons are distinctly larger and have more similar
shapes than the LGNv perikarya. In addition, the numerical density of neurons
in the ventral nucleus is significantly higher than in the dorsal nucleus. All these
morphometric parameters clearly differentiate the LGNd from the LGNv
A morphometric study of the preoptic area of the guinea pig
The aim of the study was to provide the topography and morphometric characteristics
of the preoptic area (POA) of the guinea pig. The study was carried
out on the brains of sexually mature guinea pigs of both sexes. A uniform
procedure was followed in the study of the paraffin-embedded brain tissue
blocks of males and females. The blocks were cut in the coronal plane into
50 mm sections and stained according to the Nissl method. The guinea pig POA
consists of four parts: the medial preoptic area (MPA), lateral preoptic area
(LPA), periventricular preoptic nucleus (PPN), and median preoptic nucleus
(MPN). The topography and general structure of POA parts are similar in males
and females. However, the PPNa cells of females are more intensely stained
and are more densely packed than the PPNa cells of males. For morphometric
analysis, the MPA and LPA as well as PPN and MPN were considered respectively
as uniform structures, namely MPA-LPA and PPN-MPN. The statistical
analysis showed that the volume of the PPN-MPN was larger in males than in
females, whereas the MPA-LPA volume did not differ between the sexes. Moreover,
the numerical density and the total number of neurons were statistically
larger in males than in females in both the MPA-LPA and PPN-MPN. The parameters
describing POA neurons were larger for MPA-LPA neurons in comparison
with the PPN-MPN neurons. However, in this respect no sex differences
were observed in both studied complexes. Folia Morphol 2010; 69, 1: 15-2
The nerve cells of the neostriatum in the common shrew (Sorex araneus) and bank vole (Clethrionomys glareolus): a Golgi comparative study
The studies were carried out on 12 brains derived from adult representatives of two mammalian orders, Insectivora and Rodentia. The neostriatum was compared in the common shrew (Sorex araneus) and bank vole (Clethrionomys glareolus).
Three main types of striatal neuron were distinguished in the common shrew and five types of neurons in the bank vole. The fifth type of bank vole neurons was additionally divided into two subtypes with respect to dendritic pattern
The neuronal structure of the dorsal nucleus of the lateral geniculate body in the common shrew (Sorex araneus) and the bank vole (Clethrionomys glareolus): Golgi and Nissl studies
The topography and neuronal structure of the dorsal nucleus of the lateral geniculate
body (GLd) of the common shrew and the bank vole are similar. The
lateral geniculate body of both the species examined has a homogeneous structure
and no observable cytoarchitectonic lamination. On the basis of the shape
of the dendritic arbours as well as the pattern of dendritic arborisations the
following two types of neurons were distinguished. Type I “bushy” neurons that
have multipolar or round perikarya (common shrew perikarya 9–12 µm, bank
vole perikarya 10–13 µm), with 4–6 short thick dendritic trunks that subdivide
into many bush-like branches. The dendritic trunks are smooth, in contrast to
the distal branches, which are covered with numerous spine-like protrusions of
different lengths and forms. An axon emerges from the soma, sometimes very
close to one of the primary dendrites. The type I neurons are typically projection
cells that send their axons to the primary visual cortex. These neurons predominate
in the GLd of both species. Type II neurons, which have an elongated
soma with primary dendrites arising from opposite poles of the perikaryon (common
shrew perikarya 8–10 µm, bank vole perikarya 9–11 µm). The dendritic
arbours of these cells are less extensive and their dendrites have fewer spines
than those of the type I neurons. Axons were seldom observed. The type II
neurons are presumably interneurons and are definitely less numerous than the
type I neurons
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