Transplantation of CD34 human cells into mice with severe combined immunodeficiency results in functional T cells 4 weeks after transplantation.

OBJECTIVE: Our purpose was to determine whether transplantation of fetal human CD34(+) cells into mice with severe combined immunodeficiency results in functional T cells. STUDY DESIGN: The cells used in this study were isolated from fetal human liver tissue obtained after elective termination of normal 18- to 24-week pregnancies. Women with medical conditions that could confound the outcome were excluded. Cells were labeled with fluorochrome-conjugated antibodies that recognized CD34 or other cell surface antigens. The cells were then sorted with the use of a fluorescein-activated cell sorter. The human sorted cells were injected intraperitoneally in mice with severe combined immunodeficiency. Four groups of mice were studied: group 1, injected with 10(5) CD34(+) cells (n = 17); group 2, injected with 10(5) CD34(-) cells (n = 14); group 3, injected with 10(6) unsorted cells (n = 19); and group 4, sham-injected with phosphate-buffered saline solution as controls (n = 14). At 1, 2, and 4 weeks after transplantation, the peripheral blood monocytes of the study mice were analyzed for functional T cells. Aliquots of cells (10(5)) were incubated for 48 hours with 0, 5, 10, and 20 micrograms of phytohemagglutinin. Thereafter the cells were treated with 1 microCi of tritiated thymidine. Subsequently the incorporation of tritiated thymidine was determined by liquid scintillation counting. RESULTS: Cells from mice transplanted with either unsorted cells, sorted CD34(+) cells, or CD34(-) cells showed a response to phytohemagglutinin that varied with time and with the mitogen concentration. Even though unsorted fetal human liver cells had a maximal response at 2 weeks, this posttransplantation response was not statistically significant. CD34(+) cell response to phytohemagglutinin was significant at 4 weeks after transplantation. CD34(-) cells also had a peripheral blood cell response at 4 weeks after transplantation; however, this response was not statistically significant. In addition, all mice transplanted with fetal human liver cells had some functional T cells at 4 weeks; however, this response was statistically significant only for CD34(+) cells. CONCLUSION: Transplantation of either sorted CD34 (positive or negative) cells or unsorted fetal human liver cell preparations into mice with severe combined immunodeficiency results in functional T cells. However, only the mice with transplanted CD34(+) cells demonstrated a statistically significant response.

Blunted fetal response to vibroacoustic stimulation following chronic exposure to propranolol.

A recent, prospective randomized trial has suggested that long-term use of prophylactic beta-adrenergic blocking agents may slow the rate of aortic dilation in those patients with Marfan's syndrome exhibiting evidence of existing dilation. Accordingly, administration of such medication from the midtrimester onward has been advocated in these patients. Acute oral administration of propranolol (80 mg) has been shown to depress fetal heart rate response to vibroacoustic stimulation. We present a case in which chronic administration of propranolol 150 mg/day to a patient with Marfan's syndrome with existing aortic root dilation was associated with repeated abnormal intrapartum fetal heart rate responses to vibroacoustic stimulation. Subsequent delivery of a nonhypoxic, nonacidotic infant suggests that maternal administration of beta-blockers should be considered in the interpretation of results of fetal vibroacoustic stimulation. This case also supports that in similar clinical presentations, ultrasonographic confirmation of the fetal startle response, or alternatively observation of the resulting fetal recoil may be utilized rather than the fetal heart rate, which may be modulated by maternal medications.

Immunophenotypic characterization of human fetal liver hematopoietic stem cells during the midtrimester of gestation.

OBJECTIVE: Our purpose was to define the extent to which gestational age influences the number of fetal liver cells that coexpress phenotypic markers associated with hematopoietic stem cells and major histocompatibility antigens. STUDY DESIGN: Fetal liver cells from abortuses of 9 to 24 weeks of gestation were studied (n = 61). Low-density nucleated liver cells were isolated on a discontinuous density gradient and subsequently incubated with antibodies that recognize markers of hematopoietic stem cells (i.e., CD33, CD34, CDw90, CD117, and CD123). Human leukocyte antigen class I (A, B, C) and class II (DR) antigens were also determined on these cells. Each sample was analyzed by immunocytochemistry and flow cytometry. Analysis of variance was used for statistical analysis. RESULTS: Of the markers measured, only the percentage of CD123-positive cells increased significantly with gestational age (p < 0.01). The percentage of triple-positive cells (CD34+, CD117+, and CD123+) increased with age but did not reach significance (p = 0.05). Human leukocyte A, B, and C antigens were expressed on all nucleated cells from 9 to 24 weeks of gestation. Human leukocyte DR antigen, however, was expressed only on 50% of these cells. The percentage of cells that expressed both hematopoietic stem cell markers and DR antigen did not vary with gestational age. CONCLUSIONS: From 9 to 24 weeks of gestation the number of human fetal liver hematopoietic stem cells that coexpress major histocompatibility antigens increases with advancing gestational age, largely because the percentage of these cells remains constant while the liver mass increases.

[Ureteral replacement using an ileal graft of reduced diameter. A preliminary report]. / Le remplacement urétéral par un greffon iléal de diamètre réduit. Rapport préliminaire.

Extensive or even complete loss of the ureter of a functioning kidney makes it impossible to restore the normal continuity of the urinary tract by any available surgical technique. An ileal loop of appropriate length, anastomosed to the bladder with its entire lumen, is the only tissue suitable for replacing this missing ureter; this results in the formation of a megaureter or a vesical diverticulum which, although contractile, presents dimensions and conditions of anastomosis which predispose to the development of vesico-ileal reflux and a risk of torpid infection and dangerous reabsorption of the urine. We consider that it would be useful to use the ileum to create a contractile, reduced calibre tube with properties similar to those of the ureter. This technique, which has rare indications, is feasible as illustrated by the 5 cases reported here, corresponding to 7 uretero-ileoplasties modelled according to this technique. Results were satisfactory with a follow up of 6-24 months.