The Origin of a New Progenitor Stem Cell Group in Human Development.

The observation of two precursor groups of the early stem cells (Groups I and II) leads to the realization that a first amount of fetal stem cells (Group I) migrate from the AMG (Aortal-Mesonephric-Gonadal)-region into the aorta and its branching vessels. A second group (Group II) gains quite a new significance during human development. This group presents a specific developmental step which is found only in the human. This continuation of the early development along a different way indicates a general alteration of the stem cell biology. This changed process in the stem cell scene dominates the further development of the human stem cells. It remains unclear where this phylogenetic step first appears. By far not all advanced mammals show this second group of stem cells and their axonal migration. Essentially only primates seem to be involved in this special development.

Zuckerkandl's organ improves long-term survival and function of neural stem cell derived dopaminergic neurons in Parkinsonian rats.

Transplantation of neural stem cells (NSC) derived dopamine (DA) neurons has emerged as an alternative approach to fetal neural cell transplantation in Parkinson's disease (PD). However, similar to fetal neural cell, survival of these neurons following transplantation is also limited due to limited striatal reinnervation (graft with dense neuronal core), limited host-graft interaction, poor axonal outgrowth, lack of continuous neurotrophic factors supply and principally an absence of cell adhesion molecules mediated appropriate developmental cues. In the present study, an attempt has been made to increase survival and function of NSC derived DA neurons, by co-grafting with Zuckerkandl's organ (a paraneural organ that expresses neurotrophic factors as well as cell adhesion molecules); to provide continuous NTF support and developmental cues to transplanted DA neurons in the rat model of PD. 24 weeks post transplantation, a significant number of surviving functional NSC derived DA neurons were observed in the co-transplanted group as evident by an increase in the number of tyrosine hydroxylase immunoreactive (TH-IR) neurons, TH-IR fiber density, TH-mRNA expression and TH-protein level at the transplantation site (striatum). Significant behavioral recovery (amphetamine induced stereotypy and locomotor activity) and neurochemical recovery (DA-D2 receptor binding and DA and DOPAC levels at the transplant site) were also observed in the NSC+ZKO co-transplanted group as compared to the NSC or ZKO alone transplanted group. In vivo results were further substantiated by in vitro studies, which suggest that ZKO increases the NSC derived DA neuronal survival, differentiation, DA release and neurite outgrowth as well as protects against 6-OHDA toxicity in co-culture condition. The present study suggests that long-term and continuous NTF support provided by ZKO to the transplanted NSC derived DA neurons, helped in their better survival, axonal arborization and integration with host cells, leading to long-term functional restoration in the rat model of PD.

Paraganglioma de glomus carotídeo derecho / Paraganglioma of glomus carotid right

Los Paragangliomas son tumores de cabeza y cuello poco frecuentes, histológicamente benignos, vascularizados, de crecimiento lento pudiendo ser cromafines o no. Se originan en los paraganglios extra adrenales de la cabeza neural, se presentan con mayor frecuencia en abdomen, su porcentaje de metástasis es bajo. Es más frecuente en el caso femenino, tiene una sobrevida libre de enfermedad de hasta 15 años. El diagnóstico se establece por clínica, tomografía, resonancia magnética y medicina nuclear, antiguamente se utilizaba la arteriografía carotídea. El tratamiento ideal es cirugía, sólo los casos avanzados, recidivantes o enfermedad metastásica deben recibir radioterapia. En este trabajo se describe la evolución clínico patológica de un caso de paraganglioma en cuerpo carotídeo derecho, el cual se maligniza sin cambios histológicos de importancia en corto período de evolución. Se plantea el tratamiento con Metaiodobenzilguanidina I-131 ya utilizada en otras lesiones similares con buena respuesta e influencia positiva en la sobrevida.

Perinatal development of galanin-like immunoreactivity in chromaffin tissues of the rabbit.

We have analyzed the perinatal development of galanin-like immunoreactivity (GAL-LI) and catecholamines (CA) in the paraaortal paraganglia (PGGL) and adrenal glands. In the PGGL, the tissue content of GAL-LI was highest on the day of birth and decreased postnatally. The fetal levels were lower than at birth. In contrast, the content of CA in the PGGL increased with age. In the adrenal glands, the contents of both GAL-LI and CA also increased with age. During the first postnatal week the contents of both GAL-LI and CA in the PGGL were markedly higher than in the adrenal glands. Chromatographic analysis of GAL-LI in extracts of fetal and postnatal rabbit PGGL, respectively, indicated that most of the GAL-LI from both age groups co-eluted with synthetic porcine GAL. An additional, apparently more polar, component was also detected at both ages, which may represent a differently processed form of the peptide. The high content of GAL-LI in the PGGL at birth may reflect an enhanced synthesis associated with birth.

Ultrastructure and possible function of an atrial paraganglion not directly related to atrial ganglion in the albino mouse.

The ultrastructure of a paraganglion found in right atrium of albino mouse close to the superior cava vein is described. A capillary, which occupied the central part of the paraganglion, was surrounded by three chromaffin cells. Two other chromaffin cells were also present, but neither nerve fibers nor nerve endings were seen. The possible physiological role of paraganglia is discussed.