Robert DeCresce

Induction of transplantation tolerance by allogeneic donor-derived CD4+CD25+Foxp3+ regulatory T cells

Several studies have shown that recipient-derived CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) are involved in transplantation tolerance. However, it is not clear whether allogeneic donor-derived Tregs are able to regulate T cell alloreactivity after solid organ allograft transplantation. Related studies in experimental bone marrow transplantation have shown that allogeneic donor-derived Tregs are capable of promoting early and long-term allogeneic hematopoietic engraftment, accompanied by tolerance to donor and recipient antigens. However, in these models, donor-derived Tregs are syngeneic with respect to the T responder cells. The role of Tregs in solid organ transplantation models where recipient-derived T responder and donor-derived Tregs are allogeneic has been scarcely studied. In order to determine whether allogeneic Tregs were able to regulate T cell alloreactivity, CD4(+)CD25(-) and CD8(+) T responder cells were cultured with stimulator dendritic cells in several responder-stimulator strain combinations (C57BL/6-->BALB/c, BALB/c-->C57BL/6 and C3H-->BALB/c) in the presence of responder-derived, stimulator-derived or 3rd-party-derived Tregs. Then, the frequency of IFN-gamma+ alloreactive T cells was determined by means of ELISPOT assay. The results of this study demonstrate that, regardless of the responder-stimulator strain combination, both responder-derived and stimulator-derived Tregs, but not 3rd-party-derived Tregs, significantly inhibited CD4(+) and CD8(+) T cell alloreactivity. The effect of allogeneic stimulator-derived Tregs was dependent on IL-10 and TGF-beta and reversed by exogenous IL-2. In vivo experiments in nu/nu recipients reconstituted with CD4(+)CD25(-) T responder and Tregs showed that recipient and donor-derived, but not 3rd-party-derived Tregs, significantly enhanced skin allograft survival. Importantly, T cells from both recipient-derived and donor-derived Treg-reconstituted nu/nu recipients exhibited donor-specific unresponsiveness in vitro. These results show that allogeneic donor-derived Tregs significantly inhibit T cell alloreactivity and suggest their potential use in the induction of transplantation tolerance.

Famotidine treatment of children with autistic spectrum disorders: pilot research using single subject research design

Summary. Using single subject research design, we performed pilot research to evaluate the safety and efficacy of famotidine for the treatment of children with autistic spectrum disorders. We studied 9 Caucasian boys, 3.8–8.1 years old, with a DSM-IV diagnosis of a pervasive developmental disorder, living with their families, receiving no chronic medications, and without significant gastrointestinal symptoms. The dose of oral famotidine was 2 mg/kg/day (given in two divided doses); the maximum total daily dose was 100 mg. Using single-subject research analysis and medication given in a randomized, double-blind, placebo-controlled, cross-over design, 4 of 9 children randomized (44%) had evidence of behavioral improvement. Primary efficacy was based on data kept by primary caregivers, including a daily diary; daily visual analogue scales of affection, reciting, or aspects of social interaction; Aberrant Behavior Checklists (ABC, Aman); and Clinical Global Improvement scales. Children with marked stereotypy (meaningless, repetitive behaviors) did not respond. Our subjects did not have prominent gastrointestinal symptoms and endoscopy was not part of our protocol; thus, we cannot exclude the possibility that our subjects improved due to the effective treatment of asymptomatic esophagitis. The use of famotidine for the treatment of children with autistic spectrum disorders warrants further investigation.

Enhanced Allograft Survival and Modulation of T-Cell Alloreactivity Induced by Inhibition of MMP/ADAM Enzymatic Activity

Recent studies have shown significantly increased expression of matrix metalloproteinases (MMP) and disintegrin‐type metalloproteinases (ADAM) during allograft rejection. In this regard, our previous studies have demonstrated contrasting roles for MMP‐2 and MMP‐9 during allograft rejection: MMP‐2‐deficiency enhanced allograft survival while MMP‐9‐deficiency decreased allograft survival. The aim of this study was to determine the effect of broad‐spectrum MMP/ADAM inhibition on the pathogenesis of allograft rejection. Toward this, heterotopic BALB/c cardiac allografts were transplanted into C57BL/6 recipients treated with MMP/ADAM inhibitors, GM6001 or doxycycline. Systemic MMP/ADAM inhibition significantly enhanced allograft survival. Functioning allografts recovered from MMP/ADAM inhibitor‐treated recipients showed lower cellular infiltration and tissue remodeling than rejected allografts recovered from control recipients. In addition, decreased chemotaxis of CD4+ and CD8+ T cells, B cells and macrophages was observed in vitro in the presence of MMP/ADAM inhibitors. Enhanced T‐cell alloreactivity was also observed ex vivo in MMP/ADAM inhibitor‐treated recipients and in vitro in the presence of MMP/ADAM inhibitors. These observations were associated with enhanced cytokine, chemokine and growth factor production. These results indicate that MMPs and ADAMs play a critical role in the pathogenesis of allograft rejection and may represent novel therapeutic targets for the treatment and/or prevention of this disease.

A prospective evaluation of the effect of sample collection site on intraoperative parathormone monitoring during parathyroidectomy.

BACKGROUND Sample collection site may affect the dynamics of intraoperative parathyroid hormone monitoring (IPM) and influence surgical decisions. METHODS We prospectively studied 45 patients undergoing parathyroidectomy for primary hyperparathyroidism. The IPM cure criterion was a decrease in peripheral vein (PV) parathyroid hormone (PTH) of >50% at 10 minutes after gland excision. PTH samples were collected simultaneously from PV and central vein (CV) and compared for PTH decay, the incidence of >50% PTH decay, and the incidence of normal PTH values after gland excision. RESULTS Mean PTH levels were significantly higher from the CV before and after gland excision. Mean PTH decay 10 minutes after gland excision was 89% PV versus 88% CV, resulting in mean PTH levels of 27 +/- 23 and 39 +/- 35 pg/mL, respectively (P < .0001). At 5 minutes, >50% decay in PTH was present in 98% PV versus 88% CV samples. By 10 minutes, the incidence of >50% PTH decay was equivalent (98%). This yielded normal range PTH levels from the PV versus CV in 90% versus 76% of patients at 5 minutes, 96% versus 89% at 10 minutes, and 95% versus 81% at 20 minutes. Of 45 patients, 44 (98%) are normocalcemic at a mean follow-up of 6.3 months. IPM predicted the single operative failure. CONCLUSIONS CV sampling produces significantly higher PTH levels. Surgeons sampling from a PV may observe a >50% decrease in PTH and normal range PTH values starting 5 minutes after gland excision. Surgeons who sample from the CV and require normalization of PTH levels may have to wait longer and/or continue potentially unnecessary neck exploration.

Intraoperative total serum calcium levels, unlike intraoperative intact PTH levels, do not correlate with cure of hyperparathyroidism.

BACKGROUND Intraoperative intact parathyroid hormone (iPTH) monitoring is useful in the operative management of hyperparathyroidism. Recent studies suggest that measurement of intraoperative total serum calcium (TSC) levels may be a more cost effective and readily available method of intraoperative guidance during neck dissection than iPTH levels, the gold standard. We compared the accuracy of intraoperative TSC to iPTH in predicting surgical cure during parathyroidectomy. PATIENTS AND METHODS From September 1, 2001 to October 31, 2002, 88 parathyroidectomies were performed. iPTH and TSC were measured at the start of the operation, and at 5 and 10 min after gland removal. Data were compared, and trends were analyzed with respect to removal of abnormal parathyroid tissue as confirmed by pathology. One-way analysis of variance was used to determine if decreases in TSC were significant. RESULTS The mean baseline iPTH level (418 +/- 610 pg/ml) dropped by 70% 5 min after removal of the abnormal glands (86 +/- 102 pg/ml) and by 85% at 10 min (39 +/- 39 pg/ml). The mean baseline TSC level (10.0 +/- 0.8 mg/dl) dropped by 4% at 5 min after removal of the abnormal glands (9.6 +/- 0.9 mg/dl) and remained at 4% at 10 min (9.6 +/- 0.8 mg/dl). iPTH dropped by > or =50% in 73 patients (83%) at 5 min and in 87 patients (99%) at 10 min after gland resection. TSC decreased below baseline at 5 min and remained below baseline at 10 min in only 47 patients (54%). In the remaining patients, intraoperative TSC changes were less predictable and did not respond consistently to resection of abnormal glands. CONCLUSIONS The decreases in TSC during parathyroidectomy, if present, are minimal. Unlike iPTH levels, TSC levels do not consistently decrease at 5 and 10 min after gland resection. While attractive in terms of cost and availability, intraoperative TSC levels are not clinically reliable in confirming removal of abnormal parathyroid tissue.

Catecholamine metabolites in the aqueous of retinoblastoma.

The aqueous humor of five patients with histologically proven retinoblastoma were analyzed for the main catabolic products of norephinephrine and epinephrine. In each case, there were no detectable levels of normethanephrine, metanephrine, vanilmandelic acid (VMA), and 3-methoxy, 4-hydroxy phenoglycol. The techniques are sensitive to 1 microgram/ml but will not detect the presence of homovanillic acid (HVA).

Laboratory equipment for the physician's office.

This article discusses the ideal requirements of office laboratory instruments and analyzes the various operating modes and types of reagents. General and specific features of chemistry and hematology analyzers are presented. Lastly, the financial decision-making process is outlined.

Duchenne carriers: lactate dehydrogenase isoenzyme 5 in serum and muscle.

Only two (5.5%) of 36 possible or known carriers of the gene in Duchenne dystrophy showed increased lactate dehydrogenase isoenzyme 5 (LDH-5) (U/L) in serum, while creatine kinase (CK) was increased in ten (27.8%). LDH-5 and CK did not increase simultaneously; in all five known carriers CK activity was abnormal but LDH-5 was normal. In muscle biopsy, LDH-5 was reduced in patients with Duchenne dystrophy (25.6 ± 11.5% of total, mean ± SD; controls 59.9 ± 10.3%; p ≤ 0.01) and in two of nine possible carriers, but as a group the carriers did not differ from controls: (49.9 ± 12.1%; p > 0.05).