Mandibular bone regeneration with autologous adipose-derived mesenchymal stem cells and coralline hydroxyapatite: experimental study in rats.

The purpose of this paper was to investigate the bone regeneration effect of autologous adipose tissue mesenchymal stem cells (ATMSC) in a small animal model. Twelve Wistar rats were given bilateral critical-size defects in the mandible. The defects were filled with coralline hydroxyapatite alone or combined with autologous undifferentiated ATMSC obtained from the dorsal fat pad. Studies were conducted at three and six weeks. Descriptive histology and histomorphometry revealed a significant (p < 0.05) increased bone regeneration values in the cell-treated defects at both three and six weeks. ATMSC promoted the formation of new bone in the central areas of the defects and in the scaffold micropores, both in a higher state of maturation. Autologous undifferentiated ATMSC enhanced bony healing of mandibular critical-size defects in rats when implanted with a coralline hydroxyapatite scaffold.

Isolation of Endothelial Progenitor Cells from Human Umbilical Cord Blood.

The existence of endothelial progenitor cells (EPCs) in peripheral blood and its involvement in vasculogenesis was first reported by Ashara and colleagues1. Later, others documented the existence of similar types of EPCs originating from bone marrow2,3. More recently, Yoder and Ingram showed that EPCs derived from umbilical cord blood had a higher proliferative potential compared to ones isolated from adult peripheral blood4,5,6. Apart from being involved in postnatal vasculogenesis, EPCs have also shown promise as a cell source for creating tissue-engineered vascular and heart valve constructs7,8. Various isolation protocols exist, some of which involve the cell sorting of mononuclear cells (MNCs) derived from the sources mentioned earlier with the help of endothelial and hematopoietic markers, or culturing these MNCs with specialized endothelial growth medium, or a combination of these techniques9. Here, we present a protocol for the isolation and culture of EPCs using specialized endothelial medium supplemented with growth factors, without the use of immunosorting, followed by the characterization of the isolated cells using Western blotting and immunostaining.

Graded balloon dilation atrial septostomy in severe primary pulmonary hypertension. A therapeutic alternative for patients nonresponsive to vasodilator treatment.

OBJECTIVES: We sought to investigate the acute hemodynamic effects of graded balloon dilation atrial septostomy (BDAS) and to define the long-term impact of this procedure on New York Heart Association functional class and survival in adult patients with primary pulmonary hypertension (PPH). BACKGROUND: Current treatment strategies for patients with severe and refractory PPH are limited by either technical difficulties and high mortality or cost. METHODS: We studied 15 patients with severe PPH. BDAS was successfully performed in all patients by crossing the interatrial septum with a Brockenbrough needle, followed by progressive dilation of the orifice with a Mansfield balloon in a hemodynamically controlled, step-by-step manner. RESULTS: BDAS caused an immediate significant fall in right ventricular end-diastolic pressure and in systemic arterial oxygen saturation and an increase in cardiac index. One patient died, and 14 survived the procedure and significantly improved their mean functional class (from 3.57 +/- 0.6 to 2.07 +/- 0.3 [mean +/- SD], p < 0.001). Exercise endurance (6-min test) also improved from 107 +/- 127 to 217 +/- 108 m (p < 0.001). Because of spontaneous closure, BDAS was repeated in four patients. The survival rate among patients who survived the procedure was 92% at 1, 2 and 3 years, which is better than that for historical control PPH patients (73%, 59% and 52%, respectively). CONCLUSIONS: With careful monitoring, BDAS is a safe and useful palliative treatment for selected patients with severe PPH.

Ultrastructure and electrical activity of the rat neurohypophysis.

Ultrastructural and electrophysiological studies of the rat neurohypophysis was carried out following stimulation to cause vasopressin release. Unit activity was investigated with microelectrodes, filtered, integrated, and recorded simultaneously with blood pressure in a polygraph. The basal unit activity was challenged by perfusing the hypothalamus and pituitary gland with hypertonic, hypotonic, and isotonic solutions through the internal carotid and by bleeding. Posterior lobes were fixed in osmium tetroxide and stained with uranyl acetate for electron microscopy. Single unit activity from the neural lobe showed mostly a continuous pattern of activity with a rate of discharge (RD) of 7 to 30 pulses per 10 s during control periods. Following hypertonic stimulation, out of 20 units studied, 35% increased, 10% decreased, and 55% did not change their RD. The effect of bleeding was studied in 34 units. Following the withdrawal of 1 ml of blood from the jugular vein, 29% increased, 32% decreased, and 38% did not change their RD. It is concluded that the existence in the neurohypophysis of fibers which are excited or inhibited by stimuli known to cause vasopressin release supports the hypothesis of the existence of a modulatory mechanism for neuropeptide release in the neural lobe.

Brainstem cells of origin of the cervical vagus and cardiopulmonary nerves in the neonatal pig (Sus scrofa).

The distribution of the cells of origin of the cervical vagus and cardiopulmonary nerves has been studied in neonatal piglets (Sus scrofa) ranging in age from 1 to 60 days. Cardiopulmonary nerves were identified physiologically and anatomically prior to injection of horseradish peroxidase (HRP) into the nerves. Following injection of HRP into the cervical vagus nerve retrogradely labeled neurons were present in the dorsal motor nucleus of the vagus nerve (DMV), the nucleus of the solitary tract, the nucleus ambiguus (NA), ventrolateral to the NA and in an intermediate zone between the DMV and the NA. Two unique clusters of neurons were also retrogradely labeled after injections into the vagus nerve. One group was located lateral to the most caudal levels of the DMV and extended as far caudally as the C1 spinal segment. The second distinctive group was located ventrolateral to the nucleus ambiguus in a cell column identified as the ventrolateral nucleus ambiguus (VLNA). After injections of HRP into cardiopulmonary nerves, the majority of neurons were found in the VLNA and the distinct clusters of neurons in this cell column were particularly heavily labeled. Small numbers of cells were labeled in the DMV and NA and none were labeled in the solitary nucleus after cardiopulmonary nerve injections. There were no apparent age-related differences in the degree or distribution of retrograde labeling. The distribution of neurons in the medulla oblongata projecting into cardiopulmonary nerves in the piglet is similar to that described in other species, i.e., the nucleus ambiguus, particularly its ventrolateral cell column, is the primary site of cardiomotor neurons. In addition, in the piglet there is a morphologically distinct cluster of cells related to the heart, and possibly the lungs, which does not appear to be present in other species.