Absent spermatogenesis despite early bilateral orchidopexy in 17-ketoreductase deficiency

We describe a 26-year-old patient with 17-ketoreductase deficiency who was raised as a male from 8 months and whose left testis was brought down at the age of 2.5 years and the right testis at the age of 4. Despite the early orchidopexy and not significantly decreased serum testosterone, he was sterile, and biopsy of the testes at the age of 26 revealed absence of spermatogenesis. This case indicates that the absence of spermatogonia in previously reported patients whose testes remained undescended until a later age could not be attributed solely to cryptorchidism. We suggest that decreased intratesticular testosterone due to steroidogenic defect in the developing testis mainly contributes to the arrest of spermatogenesis.     

Parturition in horses is dominated by parasympathetic activity of the autonomous nervous system

External and internal stressors prolong parturition in different species. At parturition, sympathoadrenal activation should be avoided because an increased sympathetic tone may cause uterine atonia via β₂-receptors. We hypothesized that at physiological parturition, horses are under parasympathetic dominance, and stress-response mechanisms are not activated during delivery of the foal. To evaluate stress responses, heart rate, heart rate variability, catecholamines, and cortisol were analyzed in mares (n = 17) throughout foaling. Heart rate decreased from 2 hours before (51 ± 1 beats/minute) to 2 hours after delivery (41 ± 2 beats/minute; P < 0.05). Heart rate variability variables, standard deviation of the beat-to-beat interval, and root mean square of successive beat-to-beat differences, changed over time (P < 0.05) with the highest values within 15 minutes after delivery. The number of mares with atrioventricular blocks and the number of atrioventricular blocks per mare increased over time (P < 0.01) and were significantly elevated from 15 minutes before to 45 minutes after birth of the foal. Salivary cortisol concentrations increased to a maximum at 30 minutes after delivery (25.0 ± 3.4 ng/mL; P < 0.01). Plasma epinephrine and norepinephrine concentrations showed significant fluctuations from rupture of the allantochorion to expulsion of the fetal membranes (P < 0.01) but were not markedly elevated at any time. In conclusion, mares give birth under high parasympathetic tone. Cortisol release during and after foaling is most likely part of the endocrine pathways regulating parturition and not a labor-associated stress response.     

Brain area-specific effect of TGF-beta signaling on Wnt-dependent neural stem cell expansion

Regulating the choice between neural stem cell maintenance versus differentiation determines growth and size of the developing brain. Here we identify TGF-beta signaling as a crucial factor controlling these processes. At early developmental stages, TGF-beta signal activity is localized close to the ventricular surface of the neuroepithelium. In the midbrain, but not in the forebrain, Tgfbr2 ablation results in ectopic expression of Wnt1/beta-catenin and FGF8, activation of Wnt target genes, and increased proliferation and horizontal expansion of neuroepithelial cells due to shortened cell-cycle length and decreased cell-cycle exit. Consistent with this phenotype, self-renewal of mutant neuroepithelial stem cells is enhanced in the presence of FGF and requires Wnt signaling. Moreover, TGF-beta signal activation counteracts Wnt-induced proliferation of midbrain neuroepithelial cells. Thus, TGF-beta signaling controls the size of a specific brain area, the dorsal midbrain, by antagonizing canonical Wnt signaling and negatively regulating self-renewal of neuroepithelial stem cells.     

Ontogenese des Beutefangverhaltens beim Steinkauz(Athene noctua)

Zusammenfassung 34 handaufgezogene Steinkäuze wurden unter Laborbedingungen nach ihrem Alter bei der Erstdarbietung lebender Beute, Geschlecht, Beutegröße bei den 20 ersten Beutedarbietungen und Gruppengröße miteinander verglichen. Als Beute wurden lebende, tote unbewegte und tote künstlich bewegte Mäuse, Vögel und Evertebraten und Attrappen angeboten. Die vollständige Beutefanghandlung trat nach einem Reifungsprozeß auf, welcher mehrere Stadien umfaßte und im Mittel im Alter von 62–76 Tagen abgeschlossen war. Die Beutefanghandlung beim adulten Steinkauz besteht aus obligatorischen Anteilen (Fixieren, Annäherung, Schlagen der Beute und Endhandlung-Freßakt oder/und Deponieren der Beute) und fakultativen Anteilen (z. B. Gefiedersträuben, Manteln). Die Ausprägung der einzelnen Anteile hängt von der internen Situation des Kauzes (Alter, Hungerzustand) oder/und von externen Faktoren (Beutegröße bzw. -abwehr, Nahrungskonkurrenz) ab. Gefiedersträuben erwies sich als Drohverhalten gegenüber Beute und Nahrungskonkurrenten, Beuteabdecken beim Schlagen (Manteln) als Drohverhalten gegenüber der Beute und das Beuteabdecken nach dem Schlagen (Brutstellung) als Drohgebärde gegenüber Nahrungskonkurrenten. Die Käuze unterschieden nicht zwischen aktiver und artifizieller (bloßer Ortsveränderung) Bewegung der Beute. Innerhalb eines bestimmeten Größenbereiches löste jede Art optisch erfaßter Beutebewegung die Beutefanghandlung aus.

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Ontogenetic development of catching and handling prey in the Little Owl (Athene noctua)

Summary 34 captive-raised little owls were compared in laboratory conditions according to the date of their first presentation with living prey, sex, the size of the prey during the first 20 presentations and the size of the group. Mice, birds and invertebrates (coleopters, hymenopters, lumbricides, etc.), which were either alive, dead and inert or dead and artificially moved, were presented as prey. The complete act of catching prey appeared after a process of maturing covering several stages. This process was concluded at an average age of 62 to 76 days. The act of catching prey of an adult owl consists of necessary components (locating the prey, approach, attacking the prey and final act-eating or/and storing the prey) and non-obligatory components (e.g. ruffling feathers or covering prey with the wings). These components can appear in one of several possible forms depending on the internal situation of the owl (age, state of hunger) or/and on external factors (size of prey or resistance on the part of the prey, competition for food). The owl's ruffling the feathers proved to be a threat behaviour towards the prey and competitors for food. The owl's covering prey with its wings when attacking it appeared as a threat behaviour towards the prey, and its covering prey with the wings after attacking it was a threat behaviour towards competitors for food. The beating of wings on a prey still moving (only in large prey) merely served the purpose of retaining balance. The owls did not distinguish between real and artificial movement of the prey. Within a specific size range of prey every kind of movement perceived triggered off the act of catching the prey. A reaction to the form of the prey alone occured according to a process of conditioning, in part depending on the preference of a certain kind of prey.

     

Task Type Affects Location of Language-Positive Cortical Regions by Repetitive Navigated Transcranial Magnetic Stimulation Mapping

Objectives

Recent repetitive TMS (rTMS) mapping protocols for language mapping revealed deficits of this method, mainly in posterior brain regions. Therefore this study analyzed the impact of different language tasks on the localization of language-positive brain regions and compared their effectiveness, especially with regard to posterior brain regions.

Methods

Nineteen healthy, right-handed subjects performed object naming, pseudoword reading, verb generation, and action naming during rTMS language mapping of the left hemisphere. Synchronically, 5 Hz/10 pulses were applied with a 0 ms delay

Results

The object naming task evoked the highest error rate (14%), followed by verb generation (13%) and action naming (11%). The latter revealed more errors in posterior than in anterior areas. Pseudoword reading barely generated errors, except for phonological paraphasias.

Conclusions

In general, among the evaluated language tasks, object naming is the most discriminative task to detect language-positive regions via rTMS. However, other tasks might be used for more specific questions.     

Comprehensive Reference Ranges for Hematology and Clinical Chemistry Laboratory Parameters Derived from Normal Nigerian Adults

Background

Interpretation of laboratory test results with appropriate diagnostic accuracy requires reference or cutoff values. This study is a comprehensive determination of reference values for hematology and clinical chemistry in apparently healthy voluntary non-remunerated blood donors and pregnant women.

Methods and findings

Consented clients were clinically screened and counseled before testing for HIV, Hepatitis B, Hepatitis C and Syphilis. Standard national blood donors’ questionnaire was administered to consented blood donors. Blood from qualified volunteers was used for measurement of complete hematology and chemistry parameters. Blood samples were analyzed from a total of 383 participants, 124 (32.4%) males, 125 (32.6%) non-pregnant females and 134 pregnant females (35.2%) with a mean age of 31 years. Our results showed that the red blood cells count (RBC), Hemoglobin (HB) and Hematocrit (HCT) had significant gender difference (p = 0.000) but not for total white blood count (p>0.05) which was only significantly higher in pregnant verses non-pregnant women (p = 0.000). Hemoglobin and Hematocrit values were lower in pregnancy (P = 0.000). Platelets were significantly higher in females than men (p = 0.001) but lower in pregnant women (p = 0.001) with marked difference in gestational period. For clinical chemistry parameters, there was no significant difference for sodium, potassium and chloride (p>0.05) but gender difference exists for Bicarbonate (HCO3), Urea nitrogen, Creatinine as well as the lipids (p<0.05). Total bilirubin was significantly higher in males than females (p = 0.000). Significant differences exist for all chemistry parameters between pregnant and non-pregnant women in this study (p<0.05), except Amylase and total cholesterol (p>0.05).

Conclusions

Hematological and Clinical Chemistry reference ranges established in this study showed significant gender differences. Pregnant women also differed from non-pregnant females and during pregnancy. This is the first of such comprehensive study to establish reference values among adult Nigerians and difference observed underscore the need to establish reference values for different populations.     

Endocytosis and vesicle trafficking during tip growth of root hairs

Summary. The directional elongation of root hairs, “tip growth”, depends on the coordinated and highly regulated trafficking of vesicles which fill the tip cytoplasm and are active in secretion of cell wall material. So far, little is known about the dynamics of endocytosis in living root hairs. We analyzed the motile behaviour of vesicles in the apical region of living root hairs of Arabidopsis thaliana and of Triticum aestivum by live cell microscopy. For direct observation of endocytosis and of the fate of endocytic vesicles, we used the fluorescent endocytosis marker dyes FM 1-43 and FM 4-64. Rapid endocytosis was detected mainly in the tip, where it caused a bright fluorescence of the apical cytoplasm. The internalized membranes proceeded through highly dynamic putative early endosomes in the clear zone to larger endosomal compartments in the subapical region that are excluded from the clear zone. The internalized cargo ended up in the dynamic vacuole by fusion of large endosomal compartments with the tonoplast. Before export to these lytic compartments, putative early endosomes remained in the apical zone, where they most probably recycled to the plasma membrane and back into the cytoplasm for more than 30 min. Endoplasmic reticulum was not involved in trafficking pathways of endosomes. Actin cytoskeleton was needed for the endocytosis itself, as well as for further membrane trafficking. The actin-depolymerizing drug latrunculin B modified the dynamic properties of vesicles and endosomes; they became immobilized and aggregated in the tip. Treatment with brefeldin A inhibited membrane trafficking and caused the disappearance of FM-containing vesicles and putative early endosomes from the clear zone; labelled structures accumulated in motile brefeldin A-induced compartments. These large endocytic compartments redispersed upon removal of the drug. Our results hence prove that endocytosis occurs in growing root hairs. We show the localization of endocytosis in the tip and indicate specific endomembrane compartments and their recycling. Correspondence and reprints: Institute of Botany, Slovak Academy of Sciences, Dubravska cesta 14, 845 23 Bratislava, Slovak Republic.