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Background: The use of liver allografts from an older donor (OD) (age>50 years) is a widespread strategy to manage the disparity between supply and demand of organs for liver transplantation. This study determines the effect of OD allografts on fibrosis progression and graft survival after liver transplantation in patients with and without infection caused by hepatitis C virus (HCV)., Methods: All patients undergoing liver transplantation at our center from March 1998 to December 2001 were analyzed. Protocol liver biopsies were performed at 1, 16, and 52 weeks after transplantation and yearly thereafter. One liver pathologist scored all biopsy specimens for modified hepatic activity index (0-18) and fibrosis (0-6)., Results: A total of 402 patients (167 with HCV and 235 without HCV) underwent liver transplantation during the study period. Among patients with HCV, baseline characteristics of OD recipients were similar to younger donor (YD) (age<50 years) recipients. In patients with HCV, graft survival was shorter in OD graft recipients than in YD recipients (P<0.001). In patients without HCV, graft survival was independent of donor age. In patients with HCV, a fibrosis score of 3 or greater was present in 17% of OD recipients at 4 months and in 26% at 12 months after transplantation, compared with 8% of YD recipients at 4 months and 13% at 12 months (P<0.001)., Conclusions: Liver transplantation with OD grafts is associated with rapid progression of fibrosis and decreased graft survival in patients with HCV, but not in patients without HCV. OD grafts should be considered preferentially for patients without HCV.

Background: The Roux-en-Y loop is an effective procedure for biliodigestive drainage. However, up to 15% of patients suffer from postoperative cholangitis or blind loop syndrome. A new technique to prevent motility abnormalities has been developed., Methods: Male Lewis rats were used to compare gastric emptying and transit in the small bowel after either a standard Roux-en-Y anastomosis or a new biliodigestive anastomosis technique which involves creating an "uncut" jejunal loop with luminal occlusion. Unoperated rats served as controls. (99)Technetium HIDA and (111)Indium-tagged amberlite were respectively used to investigate small bowel transit and gastric emptying., Results: Histopathology showed distinctive abnormalities only in the liver of conventional Roux-en-Y animals. No recanalization of the obliterated gut lumen occurred in uncut Roux animals. Distribution of (99)Tc-HIDA and (111)In showed were similar in both groups. Gastric emptying is slowed in both groups., Conclusions: The uncut proximal jejunum loop is a good alternative to the conventional Roux-en-Y loop and showed preserved small bowel motility and adequate jejunal transit. Gastric emptying is slowed in both groups.

In this study we exchanged portions of the poliovirus type 1 (PV1) hydrophobic domain within the membrane-associated polypeptide 3AB for the analogous sequences from human rhinovirus 14 (HRV14). The sequence exchanges were based upon a previous report in which the 22 amino acid hydrophobic region was subdivided into two domains, I and II, the latter of which was shown to be required for membrane association (J. Biol. Chem. 271 (1996), 26810). Using these divisions, the HRV14 sequences were cloned into the complete poliovirus type 1 cDNA sequence. RNAs transcribed from these cDNAs were transfected into HeLa cell monolayers and used in HeLa cell-free translation/replication assays. The data indicated that 3AB sequences from PV1 and HRV14 are interchangeable; however, the substitutions cause a range of significant RNA replication defects, and in some cases, protein processing defects. Following transfection of RNAs encoding the domain substitutions into HeLa cell monolayers, virus isolates were harvested, and the corresponding viral RNAs were sequenced. The sequence data revealed that for the carboxy-terminal domain substitutions (domain II), multiple nucleotide changes were identified in the first, second, and third positions of different codons. In addition, the data indicated that for one of the PV1/HRV14 chimeras to replicate, compensatory mutations within poliovirus protein 2B may be required.

Intestinal histamine-degrading enzymes diamine oxidase (DAO) and histamine N-methyltransferase (HNMT) activities are relatively constant per individual and bowel segment, and they reflect the functional integrity of the intestinal mucosa. It was, therefore, hypothesised that a decrease in these enzymes could be indicative of acute rejection of an intestinal allograft. Enzymatic activities of DAO and HNMT were determined in mucosal biopsies of isogeneic (Lewis-to-Lewis, n=48) and allogeneic (Brown Norway-to-Lewis, n=48) heterotopic small bowel transplants in a rat model at various time periods. Allograft recipients were not given any immunosuppression. While no changes in enzyme activities were observed in isografts up to day 8 following transplantation, significantly reduced activities of both enzymes were found in all allografts 6-8 days after transplantation. Activities of both DAO and HNMT exhibited a strong negative correlation with the histological rejection score ( P<0.01). We can conclude that DAO and HNMT activities in gut mucosa are reliable quantitative markers of acute intestinal allograft rejection in the rat that support histopathological analysis.

Background: Hepatic vitamin E may have a protective effect against hepatocyte injury; therefore, vitamin E replacement or supplementation may be beneficial in patients with cirrhosis. However, serum vitamin E may not correlate with hepatic vitamin E stores, making decisions regarding treatment difficult based on serum levels alone. The specific aims of this study were to determine hepatic concentrations of vitamin E and to determine whether serum levels of vitamin E correlate with hepatic vitamin E stores in cirrhotics., Methods: A prospective study of cirrhotics undergoing orthotopic liver transplantation (OLT) was completed. Serum and hepatic levels of vitamin E were measured by high-performance liquid chromatography. Statistical analysis was performed using rank sum tests and Spearman's rank correlation coefficient., Results: Fifty cirrhotics (33 males, 17 females; mean age of 53 years) were studied. The control group (25 males, 25 females; mean age of 47 years) consisted of the liver donors. The median serum levels of vitamin E in controls and cirrhotics were 5.95 and 7.8 mg/L, respectively (p = .009). The median hepatic levels (0.10 mg/g) in the control and cirrhotic groups were similar (p = .037). There was a significant correlation between serum and hepatic vitamin E levels in cirrhotics (R = 0.335; p = .017)., Conclusions: A positive correlation exists between serum and hepatic concentrations of vitamin E in cirrhotics, therefore making serum vitamin E levels a useful reference for treatment using exogenous vitamin E.

Background: Bacterial infection is a frequent, morbid, and mortal complication of liver transplantation. Selective bowel decontamination (SBD) has been reported to reduce the rate of bacterial infection after liver transplantation in uncontrolled trials, but benefits of this intervention have been less clear in controlled studies., Methods: Eighty candidates for liver transplantation were randomly assigned in a double-blinded fashion to an SBD regimen consisting of gentamicin 80 mg+polymyxin E 100 mg+nystatin 2 million units (37 patients) or to nystatin alone (43 patients). Both treatments were administered orally in 10 ml (increasing to 20 ml, according to predefined criteria), four times daily, through day 21 after transplantation. Anal fecal swab cultures were performed on days 0, 4, 7, and 21. Rates of infection, death, and charges for medical care were assessed from day 0 through day 60., Results: More than 85% of patients in both treatment groups began study treatment more than 3 days before transplantation. Rates of infection (32.4 vs. 27.9%), death (5.4 vs. 4.7%), or charges for medical care (median $194,000 vs. $163,000) were not reduced in patients assigned to SBD. On days 0, 4, 7, and 21, growth of aerobic gram-negative flora in fecal cultures of patients assigned to SBD was significantly less than that of patients taking nystatin alone; growth of aerobic gram-positive flora, anaerobes, and yeast was not significantly different., Conclusion: Routine use of SBD in patients undergoing liver transplantation is not associated with significant benefit.

Background: Serum vitamin A (retinol) levels may not correlate with hepatic vitamin A stores in patients with cirrhosis; thus, supplementation of vitamin A based on serum levels may have a detrimental effect. Our aim was to determine whether serum levels correlate with hepatic stores in cirrhotic patients., Methods: A prospective study of patients with cirrhosis undergoing orthotopic liver transplantation was completed. Serum and hepatic levels of vitamin A were measured by high-performance liquid chromatography. Statistical analysis was performed using rank sum tests and Spearman rank correlation coefficients., Results: Fifty cirrhotic patients (33 men and 17 women, mean age 53 years) were compared with a control group (25 men and 25 women, mean age 47 years) of liver donors. Median serum levels of retinol were 259 microg/L in controls and 166 microg/L in cirrhotic patients (p < .001). Median hepatic levels of retinol were 25 microg/g in controls and 27.5 +/- g/g in cirrhotic patients (p not significant). Total hepatic vitamin A levels (retinol plus retinyl esters) were 471 microg/g in controls and 244 microg/g in cirrhotic patients (p = .028). Serum retinol did not correlate with total hepatic vitamin A stores in cirrhotic patients (rs = .10, p = .332)., Conclusions: Serum retinol and total hepatic vitamin A stores are lower in cirrhotic patients than in controls. However, because levels of serum retinol do not correlate with hepatic vitamin A levels, the decision to prescribe vitamin A replacement for patients with cirrhosis should not be made solely on the basis of serum retinol levels.

The translation of picornavirus genomic RNAs occurs by a cap-independent mechanism that requires the formation of specific ribonucleoprotein complexes involving host cell factors and highly structured regions of picornavirus 5' noncoding regions known as internal ribosome entry sites (IRES). Although a number of cellular proteins have been shown to be involved in picornavirus RNA translation, the precise role of these factors in picornavirus internal ribosome entry is not understood. In this report, we provide evidence for the existence of distinct mechanisms for the internal initiation of translation between type I and type II picornavirus IRES elements. In vitro translation reactions were conducted in HeLa cell cytoplasmic translation extracts that were depleted of the cellular protein, poly(rC) binding protein 2 (PCBP2). Upon depletion of PCBP2, these extracts possessed a significantly diminished capacity to translate reporter RNAs containing the type I IRES elements of poliovirus, coxsackievirus, or human rhinovirus linked to luciferase; however, the addition of recombinant PCBP2 could reconstitute translation. Furthermore, RNA electrophoretic mobility-shift analysis demonstrated specific interactions between PCBP2 and both type I and type II picornavirus IRES elements; however, the translation of reporter RNAs containing the type II IRES elements of encephalomyocarditis virus and foot-and-mouth disease virus was not PCBP2 dependent. These data demonstrate that PCBP2 is essential for the internal initiation of translation on picornavirus type I IRES elements but is dispensable for translation directed by the structurally distinct type II elements.

Experiments using laser-heated diamond anvil cells show that methane (CH4) breaks down to form diamond at pressures between 10 and 50 gigapascals and temperatures of about 2000 to 3000 kelvin. Infrared absorption and Raman spectroscopy, along with x-ray diffraction, indicate the presence of polymeric hydrocarbons in addition to the diamond, which is in agreement with theoretical predictions. Dissociation of CH4 at high pressures and temperatures can influence the energy budgets of planets containing substantial amounts of CH4, water, and ammonia, such as Uranus and Neptune.

Intestinal failure can result from large resections of small intestine (short bowel syndrome) and from failure of normal intestinal motility. The medical management of short bowel syndrome centers around appropriate diet and use of specific medications including experimental trophic factors. Enteral tubes and prokinetic medications can be successfully used to treat patients with intestinal failure as a result of abnormal intestinal motility. Small bowel transplantation may be a treatment option in certain patients with intestinal failure. This article reviews the management of intestinal failure with a recent update on small bowel transplantation.

Three multicenter studies have shown that the addition of mycophenolate mofetil (MMF) to an immunosuppressive regime consisting of cyclosporin A (CSA) and prednisone (PRED) decreases the incidence of acute rejection episodes when compared with azathioprine (AZA) or placebo (1-3). In those patients receiving 3 g/d of MMF, the highest dose used in the studies, there was a trend towards an increased incidence of cytomegaloviral sepsis (CMV). We postulated therefore that MMF may represent an independent risk factor for the development of CMV infection in patients receiving renal allografts and MMF at our institution. Having altered the triple drug regime from CSA, AZA (2-2.5 mg/kg/d) and PRED to CSA, MMF (2 g/d) and PRED in July 1995, we elected to study all patients undergoing kidney transplantation for the 33-month period January 1994-September 1996, by undertaking a case control analysis to determine independent risk factors for the development of CMV infection, as defined by CMV viremia or tissue-invasive CMV. Three CMV disease-free control patients were matched to each case, these patients having been randomly selected from the entire pool of patients in the observation period. There were 31 CMV case patients and 102 control patients. Univariate analysis indicated that gender, a concomitant pancreas transplant, acute rejection and CMV seropositivity in the donor were risk factors. However, multivariate analysis indicated that only acute rejection and donor CMV seropositivity were independently linked (p < 0.05) to CMV disease in this sample. Specifically, the odds ratio (OR) for CMV disease between MMF and AZA was 1.0 (95% confidence interval (CI): 0.46-2.18). Therefore, in this case control study we find no evidence that MMF at a dose of 2 g/d is an independent risk factor for primary CMV viremia or tissue invasion in renal allograft recipients.

To meet the data-processing requirements for protocol-based decision support, a clinical data-management system must be capable of creating high-level summaries of time-oriented patient data, and of retrieving those summaries in a temporally meaningful fashion. We previously described a temporal-abstraction module (RESUME) and a temporal-querying module (Chronus) that can be used together to perform these tasks. These modules had to be coordinated by individual applications, however, to resolve the temporal queries of protocol planners. In this paper, we present a new module that integrates the previous two modules and that provides for their coordination automatically. The new module can be used as a standalone system for retrieving both primitive and abstracted time-oriented data, or can be embedded in a larger computational framework for protocol-based reasoning.

Sequence and structure comparisons with homologous trypsin-like serine proteases have predicted the S1-specificity pocket in picornavirus 3C proteinases. In this study, we examine the putative roles of such residues in poliovirus 3C substrate recognition. Single amino acid substitutions at 3C residues Thr-142, His-161, Gly-163, Gly-164, and Ala-172 were introduced into near full-length poliovirus cDNAs, and protein processing was examined in the context of authentic 3C cis cleavage activity. Our data are consistent with residues Thr-142, His-161, Gly-163, and Gly-164 acting as important determinants of 3C substrate specificity and support published models of 3C protein structure. An in vivo analysis of mutant viruses containing individual amino acid substitutions at 3C residues Thr-142 and Ala-172 suggests that such residues are important determinants for viral RNA replication. In addition, bacterially expressed, recombinant 3CD polypeptides containing amino acid substitutions at Thr-142 and Ala-172 show altered RNA binding properties in mobility shift assays that use a synthetic RNA corresponding to the poliovirus 5'-terminal sequences.

Recent studies have suggested that oxygen-derived free radicals play an important role in ischemia-reperfusion injury of the spinal cord. In other organ systems, reperfusion injury has been reduced by limiting the availability of oxygen in the reperfusion phase. The purpose of this study was to test the effect of normovolemic hemodilution and gradual reperfusion on spinal cord function after aortic cross-clamping in 84 New Zealand White rabbits. All animals underwent 21 min of infrarenal aortic cross-clamping in the conscious state by means of a previously placed aortic occlusion device and were randomized to four groups. Group 1 animals were hemodiluted to a mean (s.e.m.) hematocrit of 28(2)% by extracting 25% of the effective blood volume and reinfusing the plasma component after centrifugation concurrently with a volume of normal saline three times that of the discarded red cells. Group 2 animals (controls) were bled similarly but both plasma and red cells were reinfused, resulting in a mean (s.e.m.) hematocrit of 38(2)%. In the next two groups, distal aortic flow was recorded via an implantable Doppler device. After cross-clamping, flow was returned gradually over 45 min in animals of group 3, and abruptly in group 4. Animals were observed for 5 days and neurologic function was graded by an independent observer. Paraplegia at 5 h after clamping occurred in 75% of animals in group 1 versus 32% in group 2 (P < 0.05), and in 33% of group 3 versus 28% in group 4 (not significant). Of those animals showing initial neurologic recovery, delayed-onset paraplegia was seen in 100% in group 1 versus 87% in group 4 (not significant), and in 50% of group 3 versus 92% of group 4 (P < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

The replication of a picornavirus genomic RNA is a template-specific process involving the recognition of viral RNAs as target replication templates for the membrane-bound viral replication initiation complex. The virus-encoded RNA-dependent RNA polymerase, 3Dpol, is a major component of the replication complex; however, when supplied with a primed template, 3Dpol is capable of copying polyadenylated RNAs which are not of viral origin. Therefore, there must be some other molecular mechanism to direct the specific assembly of the replication initiation complex at the 3' end of viral genomic RNAs, presumably involving cis-acting binding determinants within the 3' noncoding region (3' NCR). This report describes the use of an in vitro UV cross-linking assay to identify proteins which interact with the 3' NCR of human rhinovirus 14 RNA. A cellular protein(s) was identified in cytoplasmic extracts from human rhinovirus 14-infected cells which had a marked binding preference for RNAs containing the rhinovirus 3' NCR sequence. This protein(s) showed reduced cross-linking efficiency for a 3' NCR with an engineered deletion. Virus recovered from RNA transfections with in vitro transcribed RNA containing the same 3' NCR deletion demonstrated a defective replication phenotype in vivo. Cross-linking experiments with RNAs containing the poliovirus 3' NCR and cytoplasmic extracts from poliovirus-infected cells produced an RNA-protein complex with indistinguishable electrophoretic properties, suggesting that the appearance of the cellular protein(s) may be a common phenomenon of picornavirus infection. We suggest that the observed cellular protein(s) is sequestered or modified as a result of rhinovirus or poliovirus infection and is utilized in viral RNA replication, perhaps by binding to the 3' NCR as a prerequisite for replication complex assembly at the 3' end of the viral genomic RNA.

Purpose: This study was undertaken to evaluate whether neurologic outcome after aortic cross-clamping in rabbits could be improved with perioperative infusion of the hydroxyl radical scavenger dimethylthiourea and, if so, to determine whether it is effective during the period of ischemia, reperfusion, or both., Methods: In 41 New Zealand White rabbits, a snare occlusion device was placed at operation around the infrarenal aorta and tunneled into a subcutaneous position. Animals were then allowed to recover and, 48 hours later, randomized into four groups. In each group, the infrarenal aorta was occluded by tightening the snare in the awake animal. In groups 1, 2, and 3, cross-clamp time was 21 minutes. Group 1 (control) animals received saline solution, whereas group 2 (preclamp 21) received dimethylthiourea 750 mg/kg intravenously just before aortic clamping. In group 3 (prerep 21), dimethylthiourea was given just before reperfusion. Group 4 received dimethylthiourea before clamping, with cross-clamp time extended to 31 minutes. A second dose of saline solution or dimethylthiourea was given 12 hours after clamping in controls and the three treatment groups, respectively. Animals were observed for 5 days, and final neurologic recovery was graded by an independent observer. Animals were then killed, and their spinal cords were removed for histologic examination., Results: Complete paraplegia and marked histologic spinal cord injury at 5 days were seen in 91% (10/11) of group 1 (control) animals, whereas all animals in group 2 (preclamp 21) showed neurologic recovery (p < 0.0001). In group 3 (prerep 21), the final paraplegia rate was 50% (5 of 10), in group 4 (preclamp 31), 100% (10 of 10)., Conclusions: Our results suggest that hydroxyl radicals play an important role in ischemia-reperfusion injury of the spinal cord and that treatment with dimethylthiourea can prevent paraplegia after 21 minutes of aortic cross-clamping in rabbits.

Purpose: We verified the hypothesis that selective deep hypothermia of the spinal cord during double thoracic aortic clamping can prevent postoperative paraplegia in dogs., Methods: Normal saline solution was circulated from the cisterna magna through an extracorporeal perfusion system consisting of a reservoir, a pump, and a heat exchanger, back into the subarachnoid space at the level of the medullary cone at a rate of 25 ml/min, starting 30 minutes before clamping, and ending after removal of the clamps. The thoracic aorta was cross-clamped below the left subclavian artery and above the diaphragm for a period of 45 minutes. Cerebrospinal fluid, intracranial, and central venous pressure and aortic pressure proximal, between, and distal to the clamps were continuously recorded. In five dogs, temperature of the circulating normal saline solution at the inflow level was maintained at 2 degrees +/- 1.5 degrees C (group 1), in five controls at 37 degrees +/- 0.8 degrees C (group 2). Five dogs underwent continuous cerebrospinal fluid drainage starting before clamping until sacrifice (group 3). Dogs were observed for up to 4 days, and neurologic function was graded by an independent observer with the Tarlov scale. Animals were then killed, and their spinal cords were prepared for microscopic examination., Results: Hemodynamic parameters were not significantly different between groups. All dogs in groups 2 and 3 were paraplegic with histologic evidence of spinal cord infarction. All animals in group 1 were neurologically normal without microscopic evidence of infarction (p < 0.005)., Conclusions: Selective deep hypothermia of the spinal cord prevents paraplegia after 45 minutes of double aortic clamping in dogs. Cerebrospinal fluid drainage was not effective in preventing paraplegia in this model.

Translation initiation by internal ribosome binding is a recently discovered mechanism of eukaryotic viral and cellular protein synthesis in which ribosome subunits interact with the mRNAs at internal sites in the 5' untranslated RNA sequences and not with the 5' methylguanosine cap structure present at the extreme 5' ends of mRNA molecules. Uncapped poliovirus mRNAs harbor internal ribosome entry sites (IRES) in their long and highly structured 5' noncoding regions. Such IRES sequences are required for viral protein synthesis. In this study, a novel poliovirus was isolated whose genomic RNA contains two gross deletions removing approximately 100 nucleotides from the predicted IRES sequences within the 5' noncoding region. The deletions originated from previously in vivo-selected viral revertants displaying non-temperature-sensitive phenotypes. Each revertant had a different predicted stem-loop structure within the 5' noncoding region of their genomic RNAs deleted. The mutant poliovirus (Se1-5NC-delta DG) described in this study contains both stem-loop deletions in a single RNA genome, thereby creating a minimum IRES. Se1-5NC-delta DG exhibited slow growth and a pinpoint plaque phenotype following infection of HeLa cells, delayed onset of protein synthesis in vivo, and defective initiation during in vitro translation of the mutated poliovirus mRNAs. Interestingly, the peak levels of viral RNA synthesis in cells infected with Se1-5NC-delta DG occurred at slightly later times in infection than those achieved by wild-type poliovirus, but these mutant virus RNAs accumulated in the host cells during the late phases of virus infection. UV cross-linking assays with the 5' noncoding regions of wild-type and mutated RNAs were carried out in cytoplasmic extracts from HeLa cells and neuronal cells and in reticulocyte lysates to identify the cellular factors that interact with the putative IRES elements. The cellular proteins that were cross-linked to the minimum IRES may represent factors playing an essential role in internal translation initiation of poliovirus mRNAs.

Th dynamics of the setting expansion of gypsum-bonded investment is complicated by many variables and not well understood. The purposes of this study were to examine the fluid mechanics of the flow of investment during setting and to determine if the presence of wax patterns influences effective setting expansion. Mesial-occlusal-distal (MOD) inlay wax patterns were invested at six different radial positions and four different axial positions in plastics casting rings. Total expansion was determined by using xeroradiography. Combined results of radial expansion data at different axial and radial locations within casting rings suggest that expansion of gypsum-bonded investment may represent a variant of the laminar flow of a viscous fluid.

Effective radial setting expansion of wax patterns in a gypsum-bonded investment is influenced by many factors, especially by the diameter of the cylindrical casting ring. The hypothesis tested was that the ratio of the volume of the casting rings to the volume of the ring liner is a primary determinant of radial setting expansion. Mesio-occlusodistal inlay wax patterns were invested individually in plastic casting rings of different lengths and diameters and imaged using xeroradiography. Effective setting expansion was determined in 34-mm-long, 28-mm-diameter rings and used as a predictor of expansion in rings of different sizes. Experimental setting expansion results did not differ significantly from the predicted values.

It has been traditional either to cast invested wax patterns immediately after the investment has set or to store the invested patterns in a humidor for casting later. This study compared the fit of MOD inlays to parent dies after casting immediately following set of the investment, after casting 1 hour following the setting of the investment in air, storage in a humidor for 7 days, and after storage in air for 7 days. The only significant differences in fit were in the group stored in a humidor, and then only at the axiogingival junctions.

It was previously demonstrated that flaring of MOD inlay castings was inversely proportional to the diameters of casting rings. The purpose of this study was (1) to determine if radial setting expansion of investment was primarily responsible for the inverse proportion and (2) to characterize further the fluid mechanics of setting expansion by determination of setting expansion in casting rings of different lengths and diameters. Eight sets of ten MOD inlay wax patterns with radiopaque markers at the axiogingival and axiopulpal junctions were individually invested in plastic casting rings in two groups: (A) 28 mm diameter and 30 mm, 32 mm, 34 mm, and 42 mm long; and (B) 28 mm, 40 mm, 51 mm, and 60 mm diameter and 34 mm long. All specimens were imaged (by xeroradiography) at specific intervals during the setting reaction; dimensions were measured on the images at each interval. In casting rings of different lengths, no significant differences (p greater than 0.05) were found in total effective setting expansion. Because setting expansion in the 28-mm-diameter rings was from 1.3% to 1.5% and diminished proportionately in rings of increasing diameter, setting expansion of investment appears to be the primary determinant of mold expansion. In casting rings of different diameters, significant differences (p less than 0.001) were found in total expansion in an apparent inverse proportion (p less than 0.001). Changes in dimension at intervals were strongly associated with time, and with time combined with diameter (p less than 0.001).

LEW recipients of ACI vascularized hind limb allografts were analyzed for lymphoid chimerism by a complement-dependent cytotoxicity assay using antisera produced across this strain combination. In assessing the technique, two LEW recipients of sublethal irradiation (400 rad), ACI bone-marrow allografts, and CsA exhibited mixed lymphoid chimerism 23 days posttransplant. Short-term CsA-treated CTA recipients that were assayed at various times following transplantation and underwent subacute rejection did not demonstrate any significant mixed lymphoid chimerism. Long-term CsA-treated CTA recipients that were assayed at various times prior to 100 days posttransplant also did not demonstrate any significant mixed lymphoid chimerism. However, following extensive CTA survival (greater than 100 days) significant mixed donor-host lymphocyte chimerism became evident in the peripheral blood, and in one recipient a large quantity of donor bone marrow remained viable in the ACI limb allograft at necropsy (greater than 200 days posttransplant). The development of donor-host lymphocyte chimerism and a wasting syndrome that followed long-term CTA survival was suggestive of GVHD.