Recurrent primary sclerosing cholangitis after orthotopic liver transplantation: is chronic rejection part of the disease process?

BACKGROUND

The possibility of primary sclerosing cholangitis (PSC) recurrence after liver transplantation has been debated. The aim of this study is to examine whether recurrent PSC and chronic rejection (CR) are different expressions of the same disease process.

METHODS

One hundred consecutive patients receiving 118 grafts for the diagnosis of PSC were reviewed and placed into three groups: group A, recurrent disease, as evidenced by cholangiographic and pathologic findings with radiographic arterial flow to the liver (n=18; 15.7%); group B, those who developed CR (n=15; 13.0%); and group C, all others (n=82; 71.3%). Cholangiograms and histopathologic specimens were examined in a blinded fashion.

RESULTS

Demographic factors were similar, except for age, with a significantly younger age and more episodes of rejection in groups A and B (P<0.03). Group A had a higher incidence of cytomegalovirus hepatitis (P=0.008). Five-year graft survivals for A, B, and C were 64.6%, 33.3%, and 76.1%, respectively (P=0.0001), 5-year patient survivals were 76.2%, 66.7%, and 89.1%, respectively (P=0.0001), and repeat transplantation rates were 27.8%, 46.7%, and 8.5%, respectively (P=0.005). Radiographically, 90% of cholangiograms in patients with recurrent disease showed at least multiple intrahepatic strictures. Histopathologically, patients with recurrent disease and CR shared many features.

CONCLUSIONS

We have described a high incidence of recurrent PSC and CR in patients who received transplants for PSC. Histopathologic analysis suggests that CR and recurrent PSC could represent a spectrum of indistinguishable disease. However, the distinct difference in clinical outcome, as evidenced by an increased repeat transplantation rate and lower graft and patient survival in the CR group, clearly suggests that they are two distinct entities that require very different treatment strategies.

A transmembrane domain-derived peptide inhibits D1 dopamine receptor function without affecting receptor oligomerization

In this study, we show that a peptide based on the sequence of transmembrane domain 6 of the D1 dopamine receptor (D1DR) specifically inhibited D1DR binding and function, without affecting receptor oligomerization. It has been shown that an analogous peptide from the beta2-adrenergic receptor disrupted dimerization and adenylyl cyclase activation in the beta2-adrenergic receptor (Hebert, T. E., Moffett, S., Morello, J. P., Loisel, T. P., Bichet, D. G., Barret, C., and Bouvier, M. (1996) J. Biol. Chem. 271, 16384-16392). Treatment of D1DR with the D1DR transmembrane 6 peptide resulted in a dose-dependent, irreversible inhibition of D1DR antagonist binding, an effect not seen in D1DR with peptides based on transmembrane domains of other G protein-coupled receptors. Incubation with the D1DR transmembrane 6 peptide also resulted in a dose-dependent attenuation of both dopamine-induced [35S]guanosine 5'-3-O-(thio)triphosphate (GTPgammaS) binding and receptor-mediated dopamine stimulation of adenylyl cyclase activity. Notably, GTPgammaS binding and cAMP production were reduced to levels below baseline, indicating blockade of ligand-independent, intrinsic receptor activity. Immunoblot analyses of the D1DR revealed the receptor existed as monomers, dimers, and higher order oligomers and that these oligomeric states were unaffected after incubation with the D1DR transmembrane 6 peptide. These findings represent the first demonstration that a peptide based on the transmembrane 6 of the D1DR may represent a novel category of noncompetitive D1DR antagonists.

Sickle cell adhesion to laminin: potential role for the alpha5 chain

Sickle red blood cell (RBC) adhesion to the endothelium and to exposed, underlying subendothelial proteins is believed to contribute to vascular occlusion in sickle cell disease. Laminin, a major component of the subendothelium, supports significant adhesion of sickle, but not normal RBCs. The purpose of this study was to define the adhesive region for sickle RBCs within a human laminin preparation using a flow adhesion assay designed to mimic physiologic flow through postcapillary venules. Because sickle RBCs did not adhere to the common laminin contaminants entactin or collagen type IV, neither of these proteins are likely to contribute to the observed adhesion to laminin. Known adhesive regions of laminin neither supported nor inhibited sickle RBC adhesion to laminin, suggesting a mechanism of adhesion previously uncharacterized in other laminin adhesion studies. Moreover, sickle RBCs did not adhere to mouse EHS laminin or to human laminin-2 (merosin), eliminating the alpha1, alpha2, beta1, and gamma1 chains as mediators of sickle cell adhesion. The monoclonal antibody 4C7, which binds at or near the G-domain of the laminin alpha5 chain, significantly inhibited sickle RBC adhesion. These results suggest that an adhesive region for sickle RBCs is contained within the laminin alpha5 chain.

Tonsillar carcinoma: analysis of treatment results

OBJECTIVE

Early stage squamous cell carcinoma of the tonsil is amenable to treatment by either surgery or radiation therapy as a single modality, with comparable rates of local control. Unfortunately, manifestation of the disease at an early stage is infrequent, and surgery or radiation alone is less successful in controlling advanced disease. This study was conducted to elucidate the optimal treatment plan for advanced stages of tonsillar carcinoma and to identify significant risk factors for development of recurrence or failure of local control.

METHOD

We reviewed the UCLA experience with treatment of all stages of tonsillar carcinoma between 1970 and 1990.

RESULTS

Actuarial local control rates were 70% for T1, 72% for T2, 50% for T3, and 0% for T4 at 5-year follow-up. Local control and overall survival rates were compared according to the type of treatment rendered for each stage.

CONCLUSIONS

From our analysis we conclude that aggressive combination therapy with surgery and radiation yields significantly higher local control rates for stages 3 and 4 tonsillar carcinomas. The advantages and disadvantages of preoperative versus postoperative radiation therapy are discussed.

Caveat: mycoplasma arginine deiminase masquerading as nitric oxide synthase in cell cultures

We used confluent cultures of dog gallbladder epithelial cells, stimulated by conditioned medium from a culture of human neonatal foreskin fibroblasts, to establish the presence of inducible nitric oxide synthase (NOS, EC 1.14.13.39). Assay was by conversion of radiolabeled arginine to citrulline. By 4 days after addition of the conditioned medium, a relatively high level of activity was observed. However, further study showed that the enzyme did not require addition of the usual cofactors for maximal activity (NADPH, FAD, FMN and tetrahydrobiopterin) and was stable in the absence of anti-proteolytic agents. Our suspicion that this enzyme might not be NOS but arginine deiminase (EC 3.5.3.6) was confirmed by enzyme purification and by the liberation of ammonia during enzyme reaction. This enzyme, which is absent from primates and virtually confined to single-cell organisms, suggested the presence of Mycoplasma, a common contaminant of cell cultures, and it was subsequently confirmed that the fibroblast culture was a source of Mycoplasma. With the widespread interest in nitric oxide and NOS, and common use of the convenient [3H]arginine assay, there is a considerable danger of the two enzymes being confused. At the very least, it is necessary to check for activity in the absence of added cofactors.

Antigen presenting phenotype of Hodgkin Reed-Sternberg cells: analysis of the HLA class I processing pathway and the effects of interleukin-10 on epstein-barr virus-specific cytotoxic T-cell recognition

Approximately 40% of Hodgkin's disease (HD) cases in Western countries carry Epstein-Barr virus (EBV) in the malignant Hodgkin-Reed-Sternberg (H-RS) cells. HLA class I-restricted cytotoxic T lymphocytes (CTLs) with specificity for viral antigens expressed in H-RS cells therefore have therapeutic potential. However, a prerequisite for CTL therapy is that the tumor target be capable of processing and presenting endogenously expressed antigens via the transporter associated with antigen processing (TAP)-dependent HLA class I pathway. We have assessed the antigen-presenting phenotype of H-RS cells in two ways. First, immunohistochemical analysis of 38 HD biopsies showed that H-RS cells were uniformly TAP1/TAP2-positive and expressed HLA class I in the majority (18 of 24, 75%) of EBV-positive cases compared with only 4 of 14 (29%) of EBV-negative cases. Second, using a panel of 5 H-RS cell lines, we showed that 4 of 5 could process and present EBV proteins to HLA class I-restricted EBV-specific CTL clones. Others have reported that human interleukin-10 (IL-10), which is expressed by H-RS cells in the majority of EBV-positive HD cases, can abrogate CTL recognition in some circumstances. However, IL-10 pretreatment of the H-RS lines or of the EBV-specific CTLs had no such effect in this system. These results support the possibility that EBV-specific CTLs may be used to treat virus-positive HD.

The prognostic significance of pre- and posttreatment SCC levels in patients with squamous cell carcinoma of the cervix treated by radiotherapy

PURPOSE

To investigate the prognostic significance of the pre- and posttreatment serum squamous cell carcinoma antigen (SCC) levels in patients with Stage I-IVA squamous cell carcinoma of the cervix primarily treated by radiotherapy.

MATERIALS AND METHODS

401 patients with squamous cell carcinoma of cervix primarily treated with radiotherapy (RT) were included in this study. All had preRT, and 249 patients had postRT serum SCC values. The association of pretreatment SCC level with the clinical parameters, including stage, hemoglobin (Hb) level, age, cell differentiation, and lymph node status, was assessed by univariate and multivariate analysis. The prognostic significance of pretreatment SCC level and these clinical parameters were evaluated. The impact of postRT residual induration and SCC levels on survival was analyzed.

RESULTS

1. PreRT SCC level strongly correlated with stage. After controlling for stage, only SCC levels higher than 10 ng/ml were associated with enlarged lymph nodes shown in CT scan. No association of preRT SCC level with other clinical parameters was found. 2. SCC level higher than 10 ng/ml, but not between 2-10 ng/ml, had significant impact on survival in a multivariate analysis. Stage, Hb levels (<10 g/dl) and positive lymph node shown by CT scan were also independent prognostic factors for survival. No significant difference in failure pattern in terms of local and/or distant sites was found in patients with different SCC levels. 3. Patients with residual induration and/or persistently elevated SCC level at 2-3 months after RT had a significantly higher incidence of treatment failure. Persistently elevated SCC level is a stronger predictor for treatment failure than residual induration by pelvic examination, and is associated with a higher incidence of distant metastasis. One third of patients with initial SCC level higher than 10 ng/ml had persistently elevated SCC.

CONCLUSION

Pretreatment SCC levels higher than 10 ng/ml are an independent predictor for poor prognosis in patients included in this study, and can be used as one of the prognostic factors for selection of patients for intensive treatment. Persistently elevated SCC levels after RT is a strong predictor for treatment failure. A combination of clinical pelvic examination and SCC levels provides useful information for the need of further work-up and management.

Secretory effects of ATP on nontransformed dog pancreatic duct epithelial cells

Extracellular triphosphate nucleotides, such as ATP, may regulate various cellular functions through specific cell surface receptors. We examine in this report the different secretory effects of ATP and analogs on nontransformed dog pancreatic duct epithelial cells (PDEC). We observed that 1) ATP, UTP, adenosine 5'-O-(3-thiotriphosphate), and, to a lesser extent, beta, gamma-methylene-ATP, but not adenosine, stimulated 125I- efflux from PDEC, suggesting a primary role for P2Y2 receptors, 2) ATP-stimulated 125I- efflux was inhibited by 5-nitro-2-(3-phenylpropylamino)benzoic acid, diphenylamine-2-carboxylate, and DIDS, suggesting mediation through Ca2+-activated Cl- channels, 3) ATP stimulated an 86Rb+ efflux sensitive to BaCl2 and charybdotoxin, thus likely occurring through Ca2+-activated K+ channels, 4) serosal or luminal addition of UTP activated apical Cl- conductance and basolateral K+ conductance when nystatin-permeabilized PDEC were studied in an Ussing chamber, suggesting the expression of P2Y2 receptors on both sides of the cell, 5) ATP stimulated mucin secretion, and 6) ATP increases intracellular Ca2+ concentration ([Ca2+]i). In conclusion, ATP and UTP interact with P2Y2 receptors on nontransformed PDEC to increase [Ca2+]i, stimulate mucin secretion, and activate ion conductances; these findings have implications for pancreatic exocrine function in both health and disease, such as cystic fibrosis.

Biliary lipid composition after liver transplantation: effect of allograft function and cyclosporine

Biliary lipid composition and bile flow are altered after orthotopic liver transplantation. Cyclosporine may have additional effects on biliary lipid composition and secretion. We studied the effects of liver transplantation, allograft function, and cyclosporine on biliary lipids in humans. Changes in lipid composition and secretion were correlated with serum cyclosporine levels, clinical events, and allograft function. Bile samples were withdrawn via a T-tube at interval time points in 17 patients during the first 3 months posttransplantation. Total and individual bile acid, cholesterol, and phospholipid were determined using high-performance liquid chromatography. Biliary lipid profiles were then correlated with clinical events, serum cyclosporine levels, and other clinical laboratory values. Biliary lipid concentrations decreased in 3 patients during periods of graft dysfunction (acute cellular rejection, drug-induced hepatitis, and inferior vena caval thrombosis) and increased with resolution of the graft injury. Serum cyclosporine levels were positively correlated with total bile acid, cholesterol, and phospholipid concentrations in bile. There was no relationship between the composition of secreted bile acids and serum cyclosporine levels. Bile acid, cholesterol, and phospholipid secretion were not uncoupled in the presence of cyclosporine. We concluded that (1) a decrease in biliary lipid concentrations may be an indicator of worsened graft function in some allografts; (2) biliary lipid concentrations are correlated with increasing cyclosporine levels; and (3) bile acid composition is unchanged, and uncoupling of secretion of other biliary lipids is not observed in the presence of cyclosporine.

Bile salts stimulate mucin secretion by cultured dog gallbladder epithelial cells independent of their detergent effect

1. Bile salts stimulate mucin secretion by the gallbladder epithelium. We have investigated whether this stimulatory effect is due to a detergent effect of bile salts. 2. The bile salts taurocholic acid (TC) and tauroursodeoxycholic acid (TUDC) and the detergents Triton X-100 (12.5-400 microM) and Tween-20 (0.1-3.2 mM) were applied to monolayers of cultured dog gallbladder epithelial cells. Mucin secretion was studied by measuring the secretion of [3H]N-acetyl-d-glucosamine-labelled glycoproteins. We also attempted to alter the fluidity of the apical membrane of the cells through extraction of cholesterol with beta-cyclodextrin (2.5-15 mM). The effect on TUDC-induced mucin secretion was studied. Cell viability was assessed by measuring lactate dehydrogenase (LDH) leakage or 51Cr release. 3. In contrast with the bile salts, the detergents were not able to cause an increase in mucin secretion without causing concomitant cell lysis. Concentrations of detergent that increased mucin release (>100 microM Triton X-100, >0.8 mM Tween-20), caused increased LDH release. Incubation with beta-cyclodextrin resulted in effective extraction of cholesterol without causing an increase in 51Cr release. However, no effect of the presumed altered membrane fluidity on TUDC (10 mM)-induced mucin secretion was observed. 4. The stimulatory effect of bile salts on mucin secretion by gallbladder epithelial cells is not affected by the fluidity of the apical membrane of the cells and also cannot be mimicked by other detergents. We conclude that the ability of bile salts to cause mucin secretion by the gallbladder epithelium is not determined by their detergent properties.

Dose-response relationship for prophylactic cranial irradiation in small cell lung cancer

PURPOSE

To determine the dose-response relationship for prophylactic cranial irradiation (PCI) in small cell lung cancer, to quantify the growth kinetics of subclinical metastases, and to determine the influence of time-delay in initiating PCI on its utility.

METHODS AND MATERIALS

Published reports of brain relapse rates in small cell lung cancer with and without PCI were collected. The reduction in brain relapse rate as a function of radiation dose was analyzed. The time interval between treatment of the primary tumor and the initiation of PCI was analyzed as a factor potentially influencing dose-response.

RESULTS

A shallow dose-response curve without any threshold in the dose intercept was demonstrated for control of subclinical brain metastases in "early PCI" (delay between initiation of treatment for primary tumor and PCI less than 60 days). By contrast "late PCI" (delay over 60 days) was associated with a significant displacement of the dose intercept. Doses over 30-35 Gy in 2-Gy fractions did not result in a further reduction in brain relapse rate, but there were too few high-dose studies to draw any definite conclusion.

CONCLUSIONS

The nearly linear dose-response relationship for reduction in brain relapses demonstrated for "early PCI" in the range of doses from zero up to 35 Gy given in 2-Gy fractions supports the model of a fairly logarithmically uniform distribution of metastatic cell number within a series of patients. When PCI is delayed, a significant threshold in dose-response was observed, consistent with a fast growth rate of untreated subclinical brain metastases from small cell lung cancer. The exact shape and locations of dose-response curves is not well established by this retrospective analysis of diverse data. A high probability of eliminating brain relapses following PCI requires a dose of about 30-35 Gy in 2-Gy fractions. Control rates in brain can be enhanced if PCI is applied early.

Culture of human main pancreatic duct epithelial cells

Attempts to grow human pancreatic duct epithelial cells in long-term culture have proven difficult. We have developed a system of growing these cells for several passages by adapting methods used to culture dog pancreatic duct cells. Epithelial cells were enzymatically dissociated from the main pancreatic duct and plated onto collagen-coated culture inserts suspended above a human fibroblast feeder layer. After primary culture, the cells were either passaged onto new inserts or plastic tissue culture plates in the absence of collagen. Cells grown on the latter plates were maintained in a serum-free medium. Primary pancreatic duct epithelial cells grow steadily to confluence as a monolayer in the feeder layer system. After primary culture, cells passaged onto new inserts with fresh feeder layer or plastic plates and fed with serum-free medium continued to develop into confluent monolayers for up to four passages. The cells were columnar with prominent apical microvilli, sub-apical secretory vesicles, and lateral intercellular junctions resembling the morphology of normal in vivo epithelial cells. These cells were also positive for cytokeratin 19, 7, and 8 and carbonic anhydrase II, as measured by immunohistochemistry. Metabolically, these cells synthesized and secreted mucin, as measured by incorporation of tritiated N-acetyl-D-glucosamine. In conclusion, we demonstrated that human pancreatic epithelial cells from the main duct can be successfully grown in culture and repeatedly passaged using a feeder layer system, with serum-free medium, and in organotypic cultures.

Protein lipid interaction in bile: effects of biliary proteins on the stability of cholesterol-lecithin vesicles

The nucleation of cholesterol crystals is an obligatory precursor to cholesterol gallstone formation. Nucleation, in turn, is believed to be preceded by aggregation and fusion of cholesterol-rich vesicles. We have investigated the effects of two putative pro-nucleating proteins, a concanavalin A-binding protein fraction and a calcium-binding protein, on the stability of sonicated small unilamellar cholesterol-lecithin vesicles. Vesicle aggregation is followed by monitoring absorbance, and upon addition of the concanavalin A-binding protein fraction the absorbance of a vesicle dispersion increases continuously with time. Vesicle fusion is probed by a fluorescence contents-mixing assay. Vesicles apparently fuse slowly after the addition of the concanavalin A-binding protein, although inner filter effects confound the quantitative measurement of fusion rates. The rates of change of absorbance and fluorescence increase with the concentration of the protein, and the second-order dimerization rate constant increases with both the protein concentration and the cholesterol content of the vesicles. On the other hand, the calcium-binding protein has no effect on the stability of the vesicle dispersion. This protein may therefore affect cholesterol crystal formation not by promoting the nucleation process, but by enhancing crystal growth and packaging. Our results demonstrate that biliary proteins can destabilize lipid vesicles and that different proteins play different roles in the mechanism of cholesterol gallstone formation.

Reconstituted human oral and esophageal mucosa in culture

We have successfully established monolayer and organotypic culture techniques for growing human oral and esophageal epithelial cells. Cells in monolayer culture were grown in serum-free medium, modified from techniques previously reported by our group. The organotypic cultures were grown in a defined medium supplemented with 10% fetal calf serum. Oral and esophageal cells were maintained in keratinocyte basal medium with pituitary extract and other supplements, and 0.05 mM calcium for 7-9 and 9-11 passages, respectively. Both cell types had similar morphology by phase contrast microscopy. When confluent, the cells were predominantly small, basaloid, and uniform and interspersed with larger, differentiated cells. By immunohistochemistry, both cell types in monolayer were positive to AE1, AE3, and 34BE12 antibodies to keratins of stratified epithelia. Oral epithelial cells in monolayer also were positive to 35BH11, representative of simple epithelial keratins, while esophageal cells were not. The esophageal cells were focally positive to K13, while the oral cells were negative. Both were negative for K19. When comparing monolayer to organotypic cultures and to in vivo specimens, there was a significant difference in the expression of keratins. Using organotypic cultures, AE1, AE3, and 34BE12 were strongly positive in both oral and esophageal cells, similar to in vivo tissues. In contrast to monolayers, both were also focally positive for K19. Esophageal cells were strongly positive for K13, while the oral cells were mildly but uniformly positive. Both were negative for keratins of simple epithelia. These two cell culture techniques offer unique opportunities to study the pathobiology, including carcinogenesis, of stable cell systems from the oral and esophageal epithelia.

Acute pancreatitis in marrow transplant patients: prevalence at autopsy and risk factor analysis

Pancreatitis has been described as an infrequent complication of marrow transplantation. This study investigated the prevalence of pancreatitis at autopsy in marrow transplant patients and determined risk factors for its development. We reviewed consecutive autopsy reports from 1991 to 1993. Medical records and laboratory reports were reviewed for analysis of clinical variables. Autopsy findings and clinical variables were correlated with the autopsy diagnosis of pancreatitis. Pancreatitis was found in 51 of 184 (28%) patients at autopsy. Of those with pancreatitis, 35% had abdominal pain, 10% had measurements of serum pancreatic enzymes, and 20% had abdominal imaging studies in the week prior to death. By univariable analysis, risk factors associated with development of pancreatitis included clinical grades 3 and 4 GVHD, GVHD at autopsy, liver GVHD at autopsy, major infection at autopsy, and increasing days of survival. By multivariable analysis, independent risk factors for its development included any GVHD at autopsy, increasing length of survival after transplantation, and major infection at autopsy. We conclude that pancreatitis is a common but often subclinical complication of marrow transplantation. Its development may be associated with a high prevalence of biliary sludge and prolonged treatment of GVHD with cyclosporine and prednisone.

The effect of N-methyl-N'-nitro-N-nitrosoguanidine on cultured dog gallbladder epithelial cells

Normal dog gallbladder epithelial cells in long-term culture were used as a model to study the morphologic, genetic, and secretory processes associated with the progression to cancer formation. Dog gallbladder epithelial cells cultured on collagen-coated plates grew into polarized monolayers, could be passaged repeatedly, and showed the typical morphological profile of well-differentiated columnar epithelial cells. After cells were exposed to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) at 10(-5) mol/L for 48 hours, the treated cells grew on plastic and could be cloned. Flow cytometry revealed emergence of an aneuploid cell subpopulation. In organotypic culture, treated cells showed a pseudostratified appearance, with cellular and nuclear pleomorphism. Large and hyperchromatic nuclei were present as well as increased mitotic rate. The proteins of MNNG-treated dog gallbladder epithelial cells showed increased phosphorylation of tyrosine residues. Treated cells showed a decrease in mucin secretion in response to prostaglandin E2, manifesting an altered pattern of mucin secretion. Transforming growth factor-beta failed to inhibit cell proliferation in the MNNG-treated cells compared with the prominent inhibition in normal cells. Together, the data reflected changes representing preliminary steps on the pathway to develop cancer cells. Our results indicate that carcinogenic chemicals can cause measurable chromosomal and cellular modifications to normal biliary epithelial cells in vitro. This model may be useful in understanding the sequential steps in carcinogenesis and affords an opportunity to study chromosomal damage, cytokinetics, changes in molecular genetic markers, and expression, as well as cell biological function during cellular transformation.

The role of adjuvant radiotherapy in the treatment of resectable desmoid tumors

PURPOSE

Desmoid tumors have a high propensity for local recurrence with surgical resection. There are many reports describing good responses of desmoid tumors to irradiation, but none have clearly established the indications for adjuvant radiotherapy in treating resectable desmoid tumors.

METHODS AND MATERIALS

A retrospective analysis was performed on 61 patients with resectable desmoid tumor(s) who were treated at our institution from 1965 to February of 1992. Five patients had multifocal disease and are analyzed separately. Fifty-six patients had unifocal disease, of which 34 had positive surgical margins. Forty-five of the 56 patients with unifocal disease were treated with surgery alone, while 11 were treated with surgery plus adjuvant radiotherapy. Median follow-up was 6 years. Local control was measured from the last day of treatment, and all cases were reviewed by our Department of Pathology.

RESULTS

Multivariate analysis of the 56 patients with unifocal disease revealed that positive margins independently predicted for local recurrence (p < or = 0.01). Only 3 of 22 patients with clear margins experienced a local recurrence, with a 6-year actuarial local control of 85%. Multivariate analysis of the 34 patients with positive margins revealed that adjuvant radiotherapy independently predicted for improved local control (p = 0.01), and patients with recurrent disease had a slightly higher risk of local recurrence (p = 0.08). The 6-year actuarial local control determined by Kaplan-Meier for patients with unifocal disease and positive margins was 32% (+/-12%) with surgery alone, and 78% (+/-14%) with surgery plus adjuvant radiotherapy (p = 0.02). Subgroup analysis of the patients with positive margins and recurrent disease revealed that those treated with surgery alone had a 6-year actuarial local control of 0% vs. 80% for those treated with surgery plus radiotherapy (p < or = 0.01). Patients with positive margins and primary disease had a trend towards improved local control with adjuvant radiotherapy, but this was not statistically significant. None of the patients treated with radiotherapy developed serious complications or a secondary malignancy.

CONCLUSIONS

Margin status is the most important predictor of local recurrence for patients with resectable, unifocal desmoid tumor. Adjuvant radiotherapy is indicated in the treatment of patients with positive margins following wide excision of recurrent disease. The role of adjuvant radiotherapy in patients with positive margins following resection of primary disease is controversial, and should be based on a balanced discussion of the potential morbidity from radiotherapy compared to the potential morbidity of another local recurrence. Adjuvant radiotherapy is less likely to benefit those with clear margins due to the excellent results for these patients treated with surgery alone. The local control of desmoid tumor in the adjuvant setting is excellent with total doses ranging from 50-60 Gy, with acceptable morbidity. Field sizes should be generous to prevent marginal recurrences, and large volume MRIs of patients with extremity lesions should be used to identify those patients with multifocal disease.

Potential effect of cyclosporin A in formation of cholesterol gallstones in pediatric liver transplant recipients

Recent advancements in liver transplantation have resulted in extended survival both for grafts and recipients. Such improvement, together with the shortage of donor organs has prompted expansion of the donor pool to include less than ideal donors, especially in life-threatening situations. The use of older liver donors has been associated with lower long-term survival. However, potential morbidity such as gallstone formation has not been explored. We analyzed bile composition in a child who developed cholesterol gallstones in the proximal bile duct two years after undergoing emergency liver transplantation with a liver from a 78-year-old donor. Oral administration of ursodeoxycholic acid (ursodiol) shifted the cholesterol composition of the bile from a supersaturated, potentially crystallized state to a liquid (micellar) state. Unlike cyclosporin A, FK506 showed an increase in the proportion of chenodeoxycholic acid and a decrease in the proportion of cholic acid, and thus may exhibit minimal or no hepatotoxic effect. Thus, in donor livers with factors known to be associated with cholesterol gallstone formation (such as age, sex, or obesity), one may consider analyzing the bile composition at the time of procurement. Depending on cholesterol and bile acid composition the use of FK506 with or without addition of ursodeoxycholic acid may be warranted.

Structural mechanisms of bile salt-induced growth of small unilamellar cholesterol-lecithin vesicles

The liver secretes cholesterol and lecithin in the form of mixed vesicles during the formation of bile. When exposed to bile salts, these metastable vesicles undergo various structural rearrangements. We have examined the effects of three different bile salts, taurocholate (TC), tauroursodeoxycholate (TUDC), and taurodeoxycholate (TDC), on the stability of sonicated lecithin vesicles containing various amounts of cholesterol. Vesicle growth was probed by turbidity measurements, quasi-elastic light scattering, and a resonance energy transfer lipid-mixing assay. Leakage of internal contents was monitored by encapsulation of fluorescence probes in vesicles. At low bile salt-to-lecithin ratios (TC/L or TUDC/L < 1), pure lecithin vesicles do not grow, but exhibit slow intervesicular mixing of lipids as well as gradual leakage. At high BS/L (TC/L or TUDC/L > 5), pure lecithin vesicles are solubilized into mixed micelles with a concomitant decrease in the overall particle size. In this regime, extensive leakage and lipid mixing occur instantaneously after exposure to bile salt. At intermediate BS/L (1 < TC/L or TUDC/L < 5), vesicles grow with time, and the rates of both leakage and lipid mixing are rapid. The data suggest that vesicles grow by the transfer of lecithin and cholesterol via diffusion in the aqueous medium. The addition of cholesterol to lecithin vesicles reduces leakage dramatically and increases the amount of BS required for complete solubilization of vesicles. The more hydrophobic TDC induces vesicle growth at a lower BS/L than does TC or TUDC. These results demonstrate the physiologic forms of lipid microstructures during bile formation and explain how the hydrophilic-hydrophobic balance of BS mixtures may profoundly affect the early stages of CH gallstone formation.

APF/CBP, the small, amphipathic, anionic protein(s) in bile and gallstones, consists of lipid-binding and calcium-binding forms

Two very similar small anionic, amphipathic proteins, a phospholipid-binding apoprotein (anionic polypeptide fraction [APF]) and a calcium-binding polypeptide (CBP), are found abundantly in bile and all types of gallstones. The often disparate properties among various preparations of APF/CBP could reflect different sources and separation procedures, leading to partly degraded and/or denatured protein and varied association of bile salts, lipids, bile pigments, and detergents. The present study presents new methods for isolation and purification of APF/CBP, and characterizes the preparations thus obtained. It was found that isolation by selective precipitation of proteins from fresh T-tube bile by added calcium chloride, followed by demineralization with ethylenediaminetetraacetic acid (EDTA), removal of salts, lipids, and some pigment by Sephadex LH-20, and serial ultrafiltration yields the purest preparations. Though free of lipids, bile salts, detergents, and most pigments, these new preparations all show the same 7-kd and 12-kd bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the same major peaks on hydrophobic high-performance liquid chromatography (HPLC), and retain the self-associative, lipid- and calcium-binding functions, typical of older preparations obtained by potentially denaturative procedures. The varied properties among APF/CBP preparations are thus apparently related mainly to their content of different proportions of two major components, lipid-binding APF and calcium-binding CBP. Immunologic cross-reactions indicate common epitopes, and amino acid analyses are also similar, suggesting that APF and CBP may have the same polypeptide backbone, but differ because of posttranslational modification(s). Sufficiently pure APF and CBP have now been obtained to permit possible structural identification by sequencing and molecular biological techniques, though such attempts have thus far been unsuccessful.

Conserved CTL epitopes within EBV latent membrane protein 2: a potential target for CTL-based tumor therapy

In healthy virus carriers, EBV is subject to strong CTL responses that principally target the EBV nuclear Ag (EBNA) 3A, 3B, 3C subset of virus proteins. In vitro-reactivated CTLs of this kind have proved very effective in treating EBV-positive immunoblastic lymphoma, a malignancy that expresses the full range of virus proteins. However, targeting other EBV-positive tumors will require CTLs that recognize some of the subdominant viral Ags since in nasopharyngeal carcinoma and EBV-positive Hodgkin's disease, EBNA1, latent membrane protein (LMP) 1, and LMP2 are the only virus proteins present. Studying healthy virus carriers (Caucasian and Chinese), we identified five CTL target epitopes in LMP2 restricted through HLA alleles particularly common in the southern Chinese population, which is most at risk for nasopharyngeal carcinoma (HLA-A2, 50%; A11, 50%; A24, 30%; and B40, 32%). Furthermore, we analyzed the effect of HLA subtype polymorphism, especially in the context of A2 for which four subtypes are present at significant frequency in the Chinese population. As to virus polymorphism, LMP2 epitope sequences (in contrast to EBNA 3A, 3B, and 3C epitopes) were shown to be antigenically conserved among EBV isolates from different world populations, including viruses present in nasopharyngeal carcinoma and Hodgkin's disease biopsy samples. Thus, nasopharyngeal carcinoma and Hodgkin's disease are predicted to express LMP2 proteins that contain conserved CTL target epitopes restricted through common HLA alleles; boosting responses to these epitopes could form the basis of a CTL-based therapy for these malignancies.

Conserved CTL epitopes within EBV latent membrane protein 2: a potential target for CTL-based tumor therapy

In healthy virus carriers, EBV is subject to strong CTL responses that principally target the EBV nuclear Ag (EBNA) 3A, 3B, 3C subset of virus proteins. In vitro-reactivated CTLs of this kind have proved very effective in treating EBV-positive immunoblastic lymphoma, a malignancy that expresses the full range of virus proteins. However, targeting other EBV-positive tumors will require CTLs that recognize some of the subdominant viral Ags since in nasopharyngeal carcinoma and EBV-positive Hodgkin's disease, EBNA1, latent membrane protein (LMP) 1, and LMP2 are the only virus proteins present. Studying healthy virus carriers (Caucasian and Chinese), we identified five CTL target epitopes in LMP2 restricted through HLA alleles particularly common in the southern Chinese population, which is most at risk for nasopharyngeal carcinoma (HLA-A2, 50%; A11, 50%; A24, 30%; and B40, 32%). Furthermore, we analyzed the effect of HLA subtype polymorphism, especially in the context of A2 for which four subtypes are present at significant frequency in the Chinese population. As to virus polymorphism, LMP2 epitope sequences (in contrast to EBNA 3A, 3B, and 3C epitopes) were shown to be antigenically conserved among EBV isolates from different world populations, including viruses present in nasopharyngeal carcinoma and Hodgkin's disease biopsy samples. Thus, nasopharyngeal carcinoma and Hodgkin's disease are predicted to express LMP2 proteins that contain conserved CTL target epitopes restricted through common HLA alleles; boosting responses to these epitopes could form the basis of a CTL-based therapy for these malignancies.

The gallbladder also secretes

The gallbladder is traditionally regarded as an absorptive organ. There is increasing evidence that the gallbladder mucosa can have a secretory function. We studied a patient with primary sclerosing cholangitis whose gallbladder was excluded from his extrahepatic bile ducts by stricture formation. He was admitted into hospital because of cholecystitis and cholangitis and required separate drainage tubes into his gallbladder and common hepatic duct. This unique combination of drains afforded the opportunity to examine hepatic bile and gallbladder secretion. We analyzed samples for fluid volume, protein, electrolyte concentrations and biliary lipids. The simultaneous, yet separate, drainage from the gallbladder and the liver had a striking difference. The former was colorless to opalescent; the latter always golden brown. Hepatic bile flow was continuous but gallbladder drainage was variable in volume, intermittent, and occurred only after a meal. The gallbladder fluid had no bilirubin, bile salts, cholesterol, or phospholipids and had the ionic profile of an extracellular fluid. It was alkaline and contained abundant bicarbonate. We have shown that the gallbladder can secrete. In addition, these observations may also have important implications in the pathogenesis and prevention of gallbladder sludge and stones.

Zn2+ promotes the self-association of human immunodeficiency virus type-1 integrase in vitro

It has been recently demonstrated that the Mg(2+)-dependent 3'-processing activity of purified human immunodeficiency virus type-1 (HIV-1) integrase is stimulated by the addition of exogenous Zn2+ [Lee, S. P., & Han, M. K. (1996) Biochemistry 35, 3837-3844]. This activation was hypothesized to result from integrase self-association. In this report, we examine the Zn2+ content of purified HIV-1 integrase by atomic absorption spectroscopy and by application of a thiol modification reagent, p-(hydroxymercuri)benzenesulfonate, with a metallochromic indicator, 4-(2-pyridylazo)resorcinol. We find that the Zn2+ content of HIV-1 integrase varies from 0.1 to 0.92 equiv of Zn2+ per monomer depending on the conditions of protein purification. In vitro activity assays, time-resolved fluorescence emission anisotropy, and gel filtration chromatographic analyses all indicate that EDTA yields an apoprotein which is predominantly monomeric and less active with Mg2+. Further, sedimentation equilibrium studies reveal that reconstitution of the apoprotein with Zn2+ results in a monomer-tetramer-octamer transition. These results suggest that Zn2+ promotes a conformation with enhanced oligomerization and thereby stimulates Mg(2+)-dependent 3'-processing. This may also imply that multimers larger than dimers (tetramers and possibly octamers) are required for in vitro activity of integrase in the presence of Zn2+ and Mg2+. It should be noted, however, that the content of Zn2+ did not significantly affect the 3'-processing and strand transfer reactions with Mn2+ in vitro.

Isolation and long-term culture of gallbladder epithelial cells from wild-type and CF mice

Mice with targeted disruption of the cftr gene show pathophysiologic changes in the gallbladder, which correlate with hepatobiliary disease seen in cystic fibrosis patients. As gallbladder epithelium secretes mucin, and as this epithelium consists of a relatively homogenous cell type, study of CFTR function in these cells would be beneficial to delineate the complex cellular functions of this protein. The size and anatomic location of the murine gallbladder makes such studies difficult in vivo. Therefore, the need exists for in vitro models of gallbladder epithelium. We describe a method to isolate and culture murine gallbladder epithelium from wild-type and CF mice. Cells were grown in a monolayer on porous inserts over a feeder layer of fibroblasts. These nontransformed cells can be successively passaged and maintain a well-differentiated epithelial cell phenotype as shown by morphologic criteria, characterized by polarized columnar epithelial cells with prominent microvilli and intercellular junctions. Organotypic cultures showed columnar cells simulating in vivo morphology. This culture system should be valuable in delineating cellular processes relating to CFTR in gallbladder epithelium.