Collection of blood mononuclear cells by leukapheresis for transplantation in a yucatan miniature swine model

A large animal model is needed to evaluate new apheresis technologies. These technologies include novel methods of harvesting the blood mononuclear cell population which contains the hematopoietic stem cells needed to restore hematopoiesis in recipients of hematopoietically lethal therapy and the use of cytokines to provide a safe and predictable method of manipulating these circulating hematopoietic stem cells. We describe the methods used to collect mononuclear cells by leukapheresis from Yucatan miniature swine. These animals are of sufficient size to tolerate the procedures and have many physiologic and hematologic similarities to man. They are of good temperament and are easily trained. Long-term venous access was obtained using single lumen silicone rubber catheters placed in the inferior vena cava. The animals were apheresed while fully awake using a Haemonetics Model V50 machine and a modified lymphocyte collection protocol. The procedure was highly efficient for the collection of mononuclear cells and a 10 pass procedure yielded a product which contained 19.7 × 10⁹ mononuclear cells, 10.7 × 10⁹ granulocytes, and 17 ml of erythrocytes in a volume of approximately 100 ml. This product can be cryopreserved and used for subsequent transplantation. The content of four apheresis procedures provides hematopoietic reconstitution of lethally irradiated swine on a time scale equivalent to transplantation of optimal numbers of bone marrow cells. © 1992 Wiley-Liss, Inc.     

NMR Microscopy of Single Neurons Using Spin Echo and Line Narrowed 2DFT Imaging

NMR microimages of single neural cells were acquired at 500 MHz using a conventional spin echo pulse sequence and a line-narrowing sequence that eliminates susceptibility effects. The data show that any contribution to the measured T₂ relaxation rate arising from diffusion in local field inhomogeneities using spin echo sequences at high fields and high spatial resolution is relatively small. We conclude that the measured T₂ difference between the nucleus and cytoplasm in these cells represents primarily a true T₂ relaxation effect arising from the interactions of water with macromolecules in the two compartments and does not result from microsusceptibility differences. These observations have implications regarding water compartmentation in single cells and the interpretation of the MR characteristics of tissues in vivo.     

Graft irradiation abrogates graft-versus-host disease in combined pancreas-spleen transplantation

A model of combined pancreas-spleen transplantation (PST) was studied in LBN F1 recipients of Lewis grafts in order to evaluate the efficacy of pretransplant graft irradiation in preventing lethal graft-versus-host disease (GVHD). Recipients of unmodified PST uniformly developed severe GVHD and died (MST = 16.7 +/- 3.8 days). Whole body donor irradiation with either 500 or 250 rad prevented lethal GVHD. Similarly, ex vivo graft irradiation with either 1000 or 500 rad also resulted in normal weight gain, graft function, and host survival for the 6-week study period. Conversely, delay of graft irradiation until 3 days after transplantation failed to prevent this complication (MST = 15.8 +/- 3.7 days). Recipients of irradiated grafts displayed glucose tolerance tests that were identical to those in the control group indicating that the doses of radiation employed in these experiments were not deleterious to islet function. Irradiated spleen grafts appeared histologically normal at 6 weeks after transplantation. Cells derived from these grafts failed to stimulate lymph node enlargement in a popliteal lymph node assay for GVHD, suggesting that these spleens may have become repopulated with host cells. These experiments confirm that PST has the potential to cause lethal GVHD and suggest that pretransplant graft irradiation may be used to prevent its occurrence.     

Imaging of cerebral blood flow markers in Huntington''s disease using single photon emission computed tomography.

Single photon emission computed tomography (SPECT) imaging of six Huntington's disease patients revealed a striking reduction in regional uptake of cerebral blood flow markers in vivo. Similar changes were found in one patient with "early stage" disease. The findings are compared with parallel magnetic resonance imaging (MRI) studies, and in one case, results of postmortem examination.     

Critical evaluation of the short "Z" bunionectomy

The authors reviewed 120 "short Z" bunionectomy operations and, on the basis of available clinical and radiographic data, selected 50 osteotomies in 36 patients for review. Follow-up averaged 21 months and ranged from 13 to 26 months. Excellent and good results were found in 92%, while fair and poor results were obtained in 8% of patients. Although seven fractures occurred in the 50 osteotomy sites, most of these resolved without sequellae after appropriate treatment.     

Association of the dopamine receptor D4 (DRD4) gene 7-repeat allele with children with attention-deficit/hyperactivity disorder (ADHD): an update.

Polymorphisms of the dopamine receptor D4 gene DRD4, 11p15.5, have previously been associated with attention-deficit/hyperactivity disorder (ADHD) [Bobb et al., 2005; Am J Med Genet B Neuropsychiatr Genet 132:109-125; Faraone et al., 2005; Biol Psychiatry 57:1313-1323; Thapar et al., 2005; Hum Mol Genet 14 Spec No. 2:R275-R282]. As a follow up to a pilot study [see Castellanos et al., 1998; Mol Psychiatry 3:431-434] consisting of 41 probands and 56 controls which found no significant association between the DRD4 7-repeat allele in exon 3 and ADHD, a greatly expanded study sample (cases n = 166 and controls n = 282) and long term follow-up (n = 107, baseline mean age n = 9, follow-up mean age of n = 15) prompted reexamination of this gene. The DRD4 7-repeat allele was significantly more frequent in ADHD cases than controls (OR = 1.2; P = 0.028). Further, within the ADHD group, the 7-repeat allele was associated with better cognitive performance (measured by the WISC-III) (P = 0.013-0.07) as well as a trend for association with better long-term outcome. This provides further evidence of the role of the DRD4 7-repeat allele in the etiology of ADHD and suggests that this allele may be associated with a more benign form of the disorder.     

Prenatal detection of D trisomy

The second instance of a prenatally diagnosed fetus of D trisomy is reported in a 45-year-old woman. The fetus had bilateral hare lip and cleft palate, arrhinencephaly, and numerous other malformations.