Transplantation potential of hematopoietic cells released into the circulation during routine chemotherapy for non-Hodgkin's lymphoma [see comments]

Primitive hematopoietic cells released into the peripheral blood (PB) were studied in 50 patients with high-grade non-Hodgkin's lymphoma enrolled in a phase III trial of intensive weekly chemotherapy (VAPEC- B) alone or with granulocyte colony-stimulating factor (G-CSF). Mononuclear cells numbers were monitored and their in vitro growth potential assessed in clonogenic progenitor cell assays and in long- term culture. Total colony-forming cells (granulocyte-macrophage [GM], burst-forming unit, erythroid [BFU-E], Mix-CFC) were increased 40-fold (median) over baseline with chemotherapy alone and 106-fold with chemotherapy and G-CSF after the final dose. CD34+ cells were increased to a median of 4%, equivalent to that in normal bone marrow (BM) controls. Circulating colony-forming cell levels were maximal when the recovering total white blood cell (WBC) count reached 5 to 10 x 10(9)/L. The timing of the maximum was reproducible in individual patients. Therefore the WBC count can be used as a guide to the timing of leukapheresis. PB cells from normal controls' and patients' prechemotherapy were unable to sustain hemopoiesis in two-stage long- term cultures. In contrast, PB cells collected from patients primed with chemotherapy alone or chemotherapy with G-CSF at the time of predicted maximal colony-forming cell release were able to generate and sustain hematopoiesis in long-term cultures at a level comparable or superior to normal BM. These findings indicate that the use of G-CSF after routine outpatient chemotherapy stimulates maximal release of primitive hemopoietic cells into the circulation, including colony- forming cells and long-term culture-initiating cells. Their numbers are comparable with those in normal BM and are such that a single leukapheresis will usually yield enough cells for hemopoietic reconstitution after myeloablative chemotherapy.     

Acute cholecystitis in pregnancy

Thirty cases of acute cholecystitis in pregnancy were identified during a 12-year period. Twenty-one patients were successfully managed with medical therapy alone. Nine underwent surgical intervention, four after failing medical therapy and five as the initial approach to therapy. Surgical therapy was complicated by preterm labor and delivery in two patients undergoing surgery during the early third trimester. One patient underwent cholecystectomy during the first trimester and subsequently aborted. There were no serious complications in patients undergoing surgery during the second trimester. These data suggest that conservative medical management can be successfully used in most patients with acute cholecystitis in pregnancy.     

Etiology of intestinal damage in gastroschisis. I: Effects of amniotic fluid exposure and bowel constriction in a fetal lamb model

Gastroschisis is often complicated by damage to the herniated small bowel, resulting in motility and absorption disturbances and occasional intestinal necrosis and atresia. To study the pathophysiology of this process, a model of gastroschisis was developed in fetal lambs. At 80 days' gestation, the anterior abdominal wall was partially excised to create a small peritoneal cavity, and the small bowel was extruded through a Silastic ring to create a defect of uniform size. In one experimental group, a tie was placed around the herniated bowel at the level of the abdominal wall to provide gradual constriction as the fetus grew. In a second group, no tie was placed. Control animals had a simple laparotomy and no abdominal wall defect; some also had a constrictor placed around the base of the bowel. The animals were delivered near term, and the bowel was evaluated histologically and by an in-vitro bowel motility assay. Histologic examination showed normal ganglion cells in all groups and no evidence of ischemic injury. A fibrous peel was seen only in bowel exposed to amniotic fluid, with or without a constrictor. Lymphatic and venous dilation, smooth-muscle thickening, and focal mucosal blunting were seen in bowel subjected to chronic obstruction by a constrictor, regardless of whether it was exposed to amniotic fluid. Both constriction of the bowel and amniotic fluid exposure were associated with a decrease in motility; these two effects were independent and additive.(ABSTRACT TRUNCATED AT 250 WORDS)     

Deletion of the distal COOH-terminus of the A2B adenosine receptor switches internalization to an arrestin- and clathrin-independent pathway and inhibits recycling

Background and purpose:

We have investigated the effect of deletions of a postsynaptic density, disc large and zo-1 protein (PDZ) motif at the end of the COOH-terminus of the rat A_2B adenosine receptor on intracellular trafficking following long-term exposure to the agonist 5′-(N-ethylcarboxamido)-adenosine.

Experimental approach:

The trafficking of the wild type A_2B adenosine receptor and deletion mutants expressed in Chinese hamster ovary cells was studied using an enzyme-linked immunosorbent assay in combination with immunofluorescence microscopy.

Key results:

The wild type A_2B adenosine receptor and deletion mutants were all extensively internalized following prolonged treatment with NECA. The intracellular compartment through which the Gln³²⁵-stop receptor mutant, which lacks the Type II PDZ motif found in the wild type receptor initially trafficked was not the same as the wild type receptor. Expression of dominant negative mutants of arrestin-2, dynamin or Eps-15 inhibited internalization of wild type and Leu³³⁰-stop receptors, whereas only dominant negative mutant dynamin inhibited agonist-induced internalization of Gln³²⁵-stop, Ser³²⁶-stop and Phe³²⁸-stop receptors. Following internalization, the wild type A_2B adenosine receptor recycled rapidly to the cell surface, whereas the Gln³²⁵-stop receptor did not recycle.

Conclusions and implications:

Deletion of the COOH-terminus of the A_2B adenosine receptor beyond Leu³³⁰ switches internalization from an arrestin- and clathrin-dependent pathway to one that is dynamin dependent but arrestin and clathrin independent. The presence of a Type II PDZ motif appears to be essential for arrestin- and clathrin-dependent internalization, as well as recycling of the A_2B adenosine receptor following prolonged agonist addition.     

Late gestation fetal magnetic resonance imaging-derived total lung volume predicts postnatal survival and need for extracorporeal membrane oxygenation support in isolated congenital diaphragmatic hernia

Purpose

Magnetic resonance imaging (MRI) has been used as an imaging modality to assess pulmonary hypoplasia in congenital diaphragmatic hernias (CDHs). The objective of this study was to determine if there is a correlation between late gestational fetal MRI-derived total lung volumes (TLVs) and CDH outcomes.

Methods

From 2006 to 2009, 44 patients met criteria of an isolated CDH with a late gestational MRI evaluation. The prenatal TLV (in milliliters) was obtained between 32 and 34 weeks gestation. The measured study outcomes included survival, need for extracorporeal membrane oxygenation (ECMO), and length of stay.

Results

There were 39 left and 5 right CDH patients. The average TLV was significantly lower for nonsurvivors (P = .01), and there was a significant association between lower TLV and the need for ECMO (P = .0001). When stratified by TLV, patients with a TLV of greater than 40 mL had a 90% survival vs 35% survival for a TLV of less than 20 mL. Furthermore, patients with a TLV greater than 40 mL had a lower rate of ECMO use (10%) than patients with a TLV of less than 20 mL (86%). Shorter length of stay was found to correlate with increasing TLV (P = .022).

Conclusion

Late gestation fetal MRI-derived TLV significantly correlates with postnatal survival and need for ECMO. Fetal MRI may be useful for the evaluation of patients who present late in gestation with a CDH.