Evaluation of the practice of reprocessing ORs in German hospitals from an infection prevention and control perspective.

BACKGROUND: The aim of this study was to analyze the cleaning and disinfection of operating rooms (ORs) status quo focusing on hygiene plans in German hospitals. METHODS: In 2016, a structured online survey was sent to infection prevention and control (IPC) specialists at the cost calculation hospitals of the Institute for the Hospital Remuneration System (InEK) and all university hospitals in Germany (n = 365). RESULTS: With a response rate of 27.4%, 78% stated that written hygiene plans were available. After cleaning and disinfecting an OR with a "septic" patient, 55% waited until surfaces were dry before reusing in accordance with national recommendations, 27% waited > 30 min. Additionally, 28% of hospitals had ORs only for "septic" patients. In 56% "septic" patients were only operated on at the end of the program. Postoperative monitoring of patients with bacteria with special IPC requirements took place in the post anesthesia care unit (PACU) (29%), operating room (OR) (52%), intensive care unit (ICU) (53%), and in the intermediate care unit (IMC) (19%). DISCUSSION AND CONCLUSIONS: Despite written hygiene plans in place the partly long duration of OR nonuse time following IPC measures, the consistent continued use of stratification for "septic" patients and the postoperative follow-up care of patients with colonizing/infecting bacteria with special IPC requirements in the OR and high care areas represent relevant potential for improvement.

Maximum intensity breast diffusion MRI for BI-RADS 4 lesions detected on X-ray mammography.

AIM: To investigate an abbreviated, contrast-agent free diffusion-weighted (DW) breast magnetic resonance imaging (MRI) protocol that provides a single image for the radiologist to read in order to non-invasively examine Breast Imaging-Reporting and Data System (BI-RADS) 4 lesions detected using breast cancer screening X-ray mammography. MATERIALS AND METHODS: This retrospective evaluation within a institutional review board-approved, prospective study included 115 women (mean 57 years, range 50-69 years) with BI-RADS 4 findings on X-ray mammography and indication for biopsy over a period of 15 months. Full diagnostic breast MRI (FDP) was performed prior to biopsy (1.5 T). Maximum intensity breast diffusion (MIBD) images were generated from DW images (b = 1,500 mm/s2, 3 mm section thickness) of the breast. MIBD and T2-weighted (T2W) images were read by two radiologists and compared to the diagnostic accuracy of an expert reading of the FDP with histopathology as the reference standard. The acquisition time of MIBD and T2W MRI was about 7 minutes. RESULTS: MIBD MRI provided a diagnostic accuracy of 87.93% (95% confidence interval [CI]: 80.58-93.24%) for R1 and 89.66% (95% CI: 82.63-94.54%) for R2. Expert reading of the FDP revealed a similar accuracy of 86.2% (95% CI: 78.67-91.43%). The positive predictive value (PPV) could be increased from 36.2% (95% CI: 28.02-45.28; X-ray mammography alone) to a mean PPV of 80.89% (R1 79.17%, R2 82.16%) using MIBD MRI. Mean reading time was 30 seconds (25%/75 percentile 24.5-41.25). CONCLUSIONS: MIBD MRI might be of supplemental value if added to the work-up of BI-RADS 4 X-ray mammography screening findings. MIBD MRI might help reduce the false-positive rate prior to biopsy for reference lesions at only limited expense of measurement and reading time.

Can Routine Imaging After Neoadjuvant Chemotherapy in Breast Cancer Predict Pathologic Complete Response?

BACKGROUND: This study evaluated breast imaging procedures for predicting pathologic complete response (pCR = ypT0) after neoadjuvant chemotherapy (NACT) for breast cancer to challenge surgery as a diagnostic procedure after NACT. METHODS: This retrospective, exploratory, monocenter study included 150 invasive breast cancers treated by NACT. The patients received magnetic resonance imaging (MRI), mammography (MGR), and ultrasound (US). The results were classified in three response subgroups according to response evaluation criteria in solid tumors. To incorporate specific features of MRI and MGR, an additional category [clinical near complete response (near-cCR)] was defined. Residual cancer in imaging and pathology was defined as a positive result. Negative predictive values (NPVs), false-negative rates (FNRs), and false-positive rates (FPRs) of all imaging procedures were analyzed for the whole cohort and for triple-negative (TN), HER2-positive (HER2+), and HER2-negative/hormone-receptor-positive (HER2-/HR+) cancers, respectively. RESULTS: In 46 cases (31%), pCR (ypT0) was achieved. Clinical complete response (cCR) and near-cCR showed nearly the same NPVs and FNRs. The NPV was highest with 61% for near-cCR in MRI and lowest with 44% for near-cCR in MGR for the whole cohort. The FNRs ranged from 4 to 25% according to different imaging methods. The MRI performance seemed to be superior, especially in TN cancers (NPV 94%; FNR 5%). The lowest FPR was 10 % in MRI, and the highest FPR was 44% in US. CONCLUSION: Neither MRI nor MGR or US can diagnose a pCR (ypT0) with sufficient accuracy to replace pathologic diagnosis of the surgical excision specimen.

Endocytosis of cholera toxin in GERL-like structures of murine neuroblastoma cells pretreated with GM1 ganglioside. Cholera toxin internalization into Neuroblastoma GERL.

Cholera toxin (CT), covalently attached to horseradish peroxidase (HRP), is a specific cytochemical marker for GM1 ganglioside (GM1) and retains the ability of the native toxin to raise levels of cyclic AMP in avian erythrocytes. Using a cytochemical stain for HRP, we found that 9% of control cultured murine neuroblastoma cells bound cholera toxin-horseradish peroxidase conjugates (CT-HRP) on their surfaces after incubations for 1 h at 4 degrees C. Exogenous GM1, the natural receptor of CT, becomes associated in the culture medium with the plasma membranes of these cells so that 96% of cells are stained. Cells preincubated with GM1 at 4 degrees C were exposed to CT-HRP for 1 h at 4 degrees C. After washing, cells were incubated at 37 degrees C for 30 min-24 h. Endocytosis of CT-HRP occurred within 30 min and CT-HRP remained, throughout the 24-h period, in tubules, vesicles, and cisternae often found near the Golgi apparatus; this aggregate of peroxidase-positive elements probably corresponds to Golgi apparatus-endoplasmic reticulum-lysosomes (GERL) of neurons. In metaphase cells, CT-HRP was observed in aggregates of vesicles and tubules clustered near the centriole. Conjugates of HRP with subunit B, the GM1 binding component of CT, were internalized by cells pretreated with GM1 as was CT-HRP. The 9% of neuroblastoma cells binding CT-HRP in the absence of exogenous GM1 internalized the ligand in a manner indistinguishable from that of the treated cells. These findings indicate that, in neuroblastoma cells, a system of vesicles, tubules, and cisternae, analogous to GERL of neurons, is the primary recipient of adsorptive endocytosis of CT bound to endogenous or exogenously introduced GM1.

Internalization of lectins in neuronal GERL.

Conjugates of ricin agglutinin and phytohemagglutinin with horseradish peroxidase (HRP) were used for a cytochemical study of internalization of their plasma membrane "receptors" in cultured isolated mouse dorsal root ganglion neurons. Labeling of cells with lectin-HRP was done at 4 degrees C, and internalization was performed at 37 degrees C in a culture medium free of lectin-HRP. 15-20 min after incubation at 37 degrees C, lectin-HRP receptor complexes were seen in vesicles or tubules located near the plasma membrane. After 1-3 h at 37 degrees C, lectin-HRP-receptor complexes accumulated in vesicles and tubules corresponding to acid phosphatase-rich vesicles and tubules (GERL) at the trans aspect of the Golgi apparatus. A few coated vesicles and probably some dense bodies contained HRP after 3-6 h of incubation at 37 degrees C. Soluble HRP was not endocytosed under the conditions of this experiment or when it was present in the incubation medium at 37 degrees C. Internalization of lectin-HRP-receptor conjugates was decreased or inhibited by mitochondrial respiration inhibitors but not by cytochalasin B or colchicine. These studies indicate that lectin-labeled plasma membrane moieties of neurons are endocytosed primarily in elements of GERL.

Pathways involved in fluid phase and adsorptive endocytosis in neuroblastoma.

The endocytosis of ricin, horseradish peroxidase (HRP), and a conjugate of ricin-HRP by monolayer cultures of murine neuroblastoma was studied using morphological and biochemical techniques. The binding of (125)I-ricin and (125)I-ricin-HRP to cells at 4 degrees C, as a function of ligand concentration, was a saturable process. The apparent affinity constants, determined at equilibrium, were 2.8 X 10(6) M(-1) for ricin and 1 x 10(6) M(-1) for ricin-HRP. The number of binding sites per cell was 8 x 10(7) and 3 x 10(7) for the lectin and the conjugate, respectively. The binding of (125)I-ricin to monolayers as not proportional to cell density. We found reduced binding at higher cell concentrations, suggesting a decrease in the accessibility of the ligand for the receptor site or fewer sites with increasing cell population. Neuroblastoma cells have an acid-phosphatase-positive network of cisternae and vesicles near the Golgi apparatus (GERL). Ricin-HRP undergoes endocytosis in vesicles and cisternae corresponding to GERL, and in residual bodies (dense bodies). The cellular uptake of ricin-HRP was 100-200 times greater than free HRP and there was no stimulation of fluid phase endocytosis by ricin. When monolayers were exposed to concentrations of native HRP 100-fold that of the conjugate, cellular uptake of peroxidase was comparable, but HRP was localized only in residual bodies and never in elements of GERL. These results support the conclusion that GERL is involved in the adsorptive endocytosis of ricin-HRP, while residual bodies are involved in the bulk uptake of HRP. In addition, the binding, uptake, and possible recycling of (125)I- subunit B (the binding subunit) of ricin and of (125)I-ricin was examined by quantitative electron microscope autoradiography. Both ricin and its binding subunit displayed similar autoradiographic grain distributions at 4 degrees C, and there was no evidence of their breakdown or recycling to the plasma membrane during endocytosis for 2 h.

Plasma membrane and internalized immunoglobulins of lymph node cells studied with conjugates of antibody or its Fab fragments with horseradish peroxidase.

Normal rat and mouse lymphoid cells were incubated at 0 degrees -4 degrees C for 1 h with purified rabbit or sheep antirat (mouse) immunoglobulin (Ig)-horseradish peroxidase (PO) conjugates or with Fab fragments of antibody coupled with peroxidase. Cells were subsequently washed and incubated in fresh medium, without labeled antibody or Fab fragments for 5-30 min at 20 degrees or 37 degrees C. With the use of the diaminobenzidine (DAB) method, distribution of peroxidase was studied in the light and electron microscopes. Fab fragments of antirat Ig antibody were iodinated with (125)I and subsequently coupled with horseradish PO. Plasma membrane and internalized immunoglobulins were detected by electron microscope autoradiography and peroxidase cytochemistry. Single- (Fab-PO), and double- ([(125)I]Fab-PO) labeled lymphoid cells showed identical patterns of surface or internal distribution of immunoglobulins. In the electron microscope, Fab-PO conjugates at 0 degrees -4 degrees C resulted in a diffuse specific staining of the plasmalemma of lymphocytes and plasma cells. Most of the small dark lymphocytes (T cells?) did not show plasma membrane Ig. Macrophages did not show plasmalemma staining, but displayed nonspecific cytoplasmic staining after incubation at 20 degrees or 37 degrees C with antibody or Fab-PO conjugates. Lymphocytes and plasma cells, after incubation with antibody-PO conjugates at 0 degrees -4 degrees C, had patchy deposits of oxidized DAB on their plasma membranes. Macrophages, similarly treated, had no plasmalemmal staining. Patch and cap formation on the plasma membrane of lymphocytes and plasma cells was seen regularly after antibody-PO incubation at 37 degrees C. Internalization patterns were different in lymphocytes and plasma cells. In lymphocytes, peroxidase staining was observed in small round or oval vesicles clustered at one pole of the cell (30 min at 37 degrees C). In plasma cells, peroxidase staining was seen in clusters of tubules resembling the Golgi apparatus. Internalization of plasma membrane IgG was less pronounced after antibody-PO labeling as compared to Fab-PO labeling.

Quantitative ultrastructural autoradiographic studies of iodinated plasma membranes of lymphocytes during segregation and internalization of surface immunoglobulins.

Rat spleen lymphocytes were iodinated (125 I) with lactoperoxidase. Quantitative autoradiographic studies on cells fixed immediately after iodination showed 19-24% of intracytoplasmic grains at 3HD and over from the plasma membrane. Normalization of grain density distribution and comparison of resulting curves with the universal curve of grain scatter of 125 I showed that a significant percentage of intracytoplasmic grains (36%) originates from intracytoplasmic labeled sources rather than from scattering from the heavily labeled plasma membrane. Damaged cells had a threefold grain density than intact cells. Radioactivity counts in sliced polyacrylamide gels of iodinated cells revealed 65-72% of total radioactivity in five peaks of apparent mol wt of 44, 50, 57, 90 and 195 thousand daltons. Segregation and internalization of anti-immunoglobulin-Ig-horseradish peroxidase (HRP) complexes from the iodinated plasma membrane proteins of lymphocytes was studied with quantitative autoradiography (125 I) and peroxidase cytochemistry; 64% of grains at 1.5HD (1,500 A) from the plasma membrane were within the cap zone, and 36% of grains remained outside the capped immunoglobulins; 45-57% of grains internalized together with Fab-anti-Ig-Ig-HRP, and 68% of grains internalized together with anti-Ig-Ig-HRP. These studies indicate that (a) iodination of rat spleen lymphocytes results in a significant internal labeling and that (b) immunoglobulins segregate into caps and internalize together with other iodinated plasma membrane proteins while a significant percentage of iodinated proteins (36%) are excluded from the immunoglobulin caps or internalization sites (32-55%).

Endosomes and Golgi vesicles in adsorptive and fluid phase endocytosis.

We studied with morphometric methods the endocytosis by pheochromocytoma cells of a conjugate of wheat germ agglutinin with ferritin (WGA-Ft) and of horseradish peroxidase (HRP). Quantitative studies indicated that WGA-Ft was cleared slowly from cell surfaces and that it was not recycled to the surface. Cells labeled with WGA-Ft for 15 min at room temperature were washed and incubated in medium containing HRP for 15 or 30 min at 37 degrees C. The greatest proportion of labeled vesicles and tubules contained only WGA-Ft (83.4% at 15 min and 85.3% at 30 min). A very small fraction of labeled vesicles and tubules contained only HRP (0.2% at 15 min and 0.9% at 30 min). Vesicles and tubules at the Golgi apparatus were labeled almost exclusively with WGA-Ft (97% at 15 min and 30 min); the rest had both labels. Most labeled lysosomes contained both labels (80.1% at 15 min and 80.8% at 30 min). Of the remainder more contained WGA-Ft alone (20% at 15 min and 10.9% at 30 min), then HRP alone (none at 15 min and 8.2% at 30 min). In contrast to the various and varying patterns of labeling with WGA-Ft and HRP of the other organelles studied, the vast majority of endosomes contained both markers (94.1% at 15 min and 100% at 30 min); the rest contained WGA-Ft only. These results demonstrate that endosomes are recipients of both fluid phase and adsorptive endocytosis markers; these findings are consistent with the hypothesis that endosomes mediate the sorting out and subsequent intracellular traffic of membrane bound and fluid phase markers. Cisterns of the Golgi apparatus did not contain WGA-Ft; in sharp contrast, when WGA-HRP was used, the cisterns of the Golgi apparatus consistently contained HRP.

Endocytosis of exogenous GM1 ganglioside and cholera toxin by neuroblastoma cells.

Cholera toxin (CT) covalently linked to horseradish peroxidase (HRP) is a specific cytochemical marker for its receptor, the monosialoganglioside GM1. The binding and endocytosis of exogenous [3H]GM1 by cultured murine neuroblastoma cells (line 2A [CCl-131] ), which contain predominantly GM3, was examined by quantitative electron microscope autoradiography. The relationship between exogenous receptor, [3H]GM1, and CT HRP was studied in double labeling experiments consisting of autoradiographic demonstration of [3H]GM1 and cytochemical visualization of HRP. Exogenous [3H]GM1 was not degraded after its endocytosis by cells for 2 h at 37 degrees C. Quantitative studies showed similar grain density distributions in cells treated with [3H]GM1 alone and in cells treated with [3H]GM1 followed by CT-HRP. Qualitative studies conducted in double labeling experiments showed autoradiographic grains over the peroxidase-stained plasma membrane, lysosomes, and vesicles at the trans aspect of the Golgi apparatus. The findings indicate that exogenous glycolipid is associated with the plasmid membrane of deficient cells and undergoes endocytosis. The quantitative ultra-structural autoradiographic studies are consistent with the hypothesis that the spontaneous endocytosis of exogenous [3H]GM1 controls the subsequent uptake of CT-HRP.

Transneuronally transported wheat germ agglutinin labels glia as well as neurons in the rat visual system.

Following intraocular injection in adult rats of 125I-labeled wheat germ agglutinin (I-WGA), the ultrastructural distribution of label in the superior colliculus and lateral geniculate was examined by electron microscope autoradiography. Three days after injection, 5.4% of the label in the lateral geniculate was associated with neuronal perikarya, and 3.6% was associated with glial perikarya. The corresponding figures for the superior colliculus were 5.1% and 0.8%. When the data were expressed as number of grains per micron 2 cytoplasm, there was no statistically significant difference between the grain density over neuronal or glial cytoplasm in either the lateral geniculate or the superior colliculus. A statistical analysis of the distance between the silver grains and the cell membranes showed that in both neurons and glia, the observed labeling was the product of internalized I-WGA and not the result of scatter from the neuropil or from label bound to the surface of the cells. These results indicate that much of the WGA released from axons and axon terminals is not confined to a specific "transsynaptic" pathway, but produces a generalized labeling of nearby cells, much like a microinjection of WGA into the region.

A quantitative electron microscopic study of the intracellular localization of wheat germ agglutinin in retinal neurons.

Previous work has established that, following endocytosis, wheat germ agglutinin, like a number of other plasma membrane bound ligands, is transported to the Golgi apparatus-complex. Previous studies that provided qualitative information about the intracellular distribution of internalized wheat germ agglutinin used techniques that precluded any quantitative conclusions about the relative magnitude of the labeling of endosomes, lysosomes, and the Golgi apparatus-complex. Using quantitative ultrastructural autoradiography, this study compares the time course and relative magnitude of labeling of various intracellular compartments to the labeling in the Golgi area. Fifteen minutes after intraocular injection, wheat germ agglutinin is confined to the inner surface of the retina and the immediate subsurface neuropil with little labeling of the retinal ganglion cell perikarya. Thirty minutes after injection, the plasma membrane (6.97 +/- 1.17), endosomes (10.27 +/- 3.98), smooth vesicles and tubules (1.94 +/- 1.66), and lysosomes (2.42 +/- 1.21) of the retinal ganglion cells are labeled, while the Golgi apparatus-complex is not labeled (0.29 +/- 0.25). (Figures in parentheses are the calculated relative radioactive source density +/- the standard deviation.) The relative labeling density of the plasma membrane and endosomes decreases somewhat during the next 90 minutes (plasma membrane, 4.76 +/- 0.67; endosomes, 7.23 +/- 2.02), while the labeling density of smooth vesicles and tubules and of lysosomes rises (smooth vesicles and tubules, 5.56 +/- 0.94; lysosomes, 7.76 +/- 1.56). The Golgi apparatus-complex, which is unlabeled at 30 minutes, is weakly labeled at 2 hours (1.26 +/- 0.28). The fact that the lysosomes are already labeled at 30 minutes while the Golgi apparatus-complex is unlabeled at that time indicates that the transport of wheat germ agglutinin to the Golgi apparatus-complex is a relatively late phenomenon, and suggests that the bulk of the wheat germ agglutinin destined for lysosomes does not pass through the Golgi apparatus-complex.

A simple solution to a technical complication in "piggyback" liver transplantation.

"Piggyback" orthotopic liver transplantation is a technical modification of the standard technique that has found favor with a number of surgeons. One possible complication is that of venous outflow obstruction, which presents as an acute Budd-Chiari syndrome. If not rapidly corrected, it is almost inevitable that the newly implanted graft will fail. Additionally, severe portal hypertension and general infradiaphragmatic venous stasis may compound the damage. We find that anastomosing the donor infrahepatic vena cava to the recipient suprarenal vena cava in an end-to-side fashion is an excellent way to correct the problem.

Hepatic artery thrombosis after pediatric liver transplantation--a medical or surgical event?

Hepatic artery thrombosis (HAT) is one of the most serious complications after orthotopic liver transplantation, and is associated with a high morbidity and mortality. This study retrospectively reviewed 66 liver transplants in children under the age of 10 years during a year-long period at a single institution. A total of 28 perioperative variables were analyzed to identify responsible factors of HAT. Of the 66 children, 18 (26%) developed HAT within 15 days after the transplant (HAT group); 29 (42%) had an uneventful postoperative course (control group). To avoid the possible influence of other complications 19 patients were excluded. Of the variables compared between the 2 study groups, three surgical factors (diameter of the hepatic artery--greater or less than 3 mm; type of arterial anastomosis--end-to-end versus the use of an iliac graft or aortic conduit; and number of times the anastomosis was redone--one versus more than one), were found to be significantly different (P less than .05) between HAT and control groups. Two medical factors also were significantly different: the use of intraoperative transfusion of fresh frozen plasma (FFP) and the administration of postoperative prophylactic anticoagulant treatment. A heparin and dextran-40 protocol appeared to be effective in preventing HAT (P less than .02). Moreover, after multivariate analysis, anticoagulation therapy was demonstrated to be the major independent variable influencing HAT. A better definition of factors responsible for the occurrence of HAT is required. This study should help in formulating effective methods to decrease the incidence of this dreaded complication after liver transplantation.

Interferon-alpha and ribavirin for the treatment of recurrent hepatitis C after liver transplantation.

BACKGROUND: Initial studies utilizing interferon-alpha and ribavirin for the treatment of recurrent hepatitis C virus (HCV) infection after liver transplantation showed promising results. Here we report our single-center experience using this combination therapy. METHODS: Liver transplant recipients with recurrent HCV (elevated serum aminotransferases, positive serum HCV RNA, and biopsy-proven hepatitis without rejection) received interferon-alpha (1.5-3 million units subcutaneously three times a week) and ribavirin (400-1000 mg p.o. daily) for 12 months or more. Serum aminotransferases, HCV RNA, and severity of hepatitis were followed. RESULTS: Thirty-two patients have been treated for at least 3 months, including 13 who have been on 12 or more months of therapy. Three died from allograft failure due to recurrent HCV. Dose reductions of interferon-alpha and/or ribavirin occurred in 22 patients. Thirteen had their medications permanently discontinued for severe adverse effects. Twenty-six patients (81%) had a biochemical response (BR; normalization of serum aminotransferases) after 3 months. End-of-treatment and sustained BR were 77% and 71%, respectively. Mean viral loads decreased 68-77%; however, only three patients became serum HCV RNA negative. After 12 months of therapy, no histological improvement was observed in 11 patients who were biopsied. Patients who received mycophenolate mofetil or daclizumab had a less likelihood of achieving a BR. CONCLUSIONS: A significant number of patients did not tolerate interferon-alpha or ribavirin. Although BR was excellent and mean viral loads decreased significantly, virological clearance was poor and no histological improvement was noted. A more efficacious treatment with less adverse effects for recurrent HCV after liver transplantation is needed.

Efficacy of tacrolimus as rescue therapy for chronic rejection in orthotopic liver transplantation: a report of the U.S. Multicenter Liver Study Group.

BACKGROUND: A study was performed by 17 different U.S. liver transplantation centers to determine the safety and efficacy of conversion from cyclosporine to tacrolimus for chronic allograft rejection. METHODS: Ninety-one patients were converted to tacrolimus a mean of 319 days after liver transplantation. The indication for conversion was ongoing chronic rejection confirmed by biochemical and histologic criteria. Patients were followed for a mean of 251 days until the end of the study. RESULTS: Sixty-four patients (70.3%) were alive with their initial hepatic allograft at the conclusion of the study period and were defined as the responder group. Twenty-seven patients (29.7%) failed to respond to treatment, and 20 of them required a second liver graft. The actuarial graft survival for the total patient group was 69.9% and 48.5% at 1 and 2 years, respectively. The actuarial patient survival at 1 and 2 years was 84.4% and 81.2%, respectively. Two significant positive prognostic factors were identified. Patients with a total bilirubin of < or = 10 mg/dl at the time of conversion had a significantly better graft and patient survival than patients converted with a total bilirubin > 10 mg/dl (P=0.00002 and P=0.00125, respectively). The time between liver transplantation and conversion also affected graft and patient survival. Patients converted to tacrolimus < or = 90 days after transplantation had a 1-year actuarial graft and patient survival of 51.9% and 65.9%, respectively, compared with 73.2% and 87.7% for those converted > 90 days after transplantation. The mean total bilirubin level for the responder group was 7.1 mg/dl at the time of conversion and decreased significantly to a mean of 3.4 mg/dl at the end of the study (P=0.0018). Thirteen patients (14.3%) died during the study. Sepsis was the major contributing cause of death in most of these patients. CONCLUSIONS: Our results suggest that conversion to tacrolimus for chronic rejection after orthotopic liver transplantation represents an effective therapeutic option. Conversion to tacrolimus before development of elevated total bilirubin levels showed a significant impact on long-term outcome.

Resolution of diaminobenzidine for the detection of horseradish peroxidase on surfaces of cultured cells.

The resolution of indirect immunoperoxidase methods for localizing antigens on the surface of plasma membranes of cultured cells was tested using dissociated monolayer cultures of ciliary ganglion neurons prelabeled with cationic ferritin. Clusters of ferritin were produced on the cell surface by warming the cells to 37 degrees C after the ferritin, rabbit anti-ferritin, and goat anti-rabbit immunoglobulin coupled to horseradish peroxidase had all been applied. Intense 3,3'-diaminobenzidine tetrahydrochloride (DAB) staining was limited to the regions immediately surrounding the ferritin clusters. The lateral spread of the DAB reaction product beyond the outer ferritin particles in each cluster averaged 54-81 nm in four experiments. A second type of increased density, coinciding with the thickness of the plasma membrane, was also seen. These stained plasma membranes extended 161-339 nm from the ferritin clusters.

Identification of a novel protein (G210) specific to the Golgi apparatus.

A monoclonal antibody, 3C9, has enabled the detection of a novel Golgi-specific protein in bovine tissues. Immunohistochemical studies at the light microscopic level have detected the 3C9 antigen only in certain cells: exocrine pancreas, gut epithelium, and thymus epithelium. Examination of gut and pancreas by immunoelectron microscopy showed a localization exclusive to the Golgi apparatus. The relative molecular weight of the antigen detected by immunoblotting is 210,000 daltons. The antigen is not extracted from microsomal membranes of bovine gut epithelium by sodium carbonate solutions. Furthermore, the 3C9 antigen enters into the detergent phase when Triton X-114 partitioning methods are used. These data strongly suggest that this novel antigen is an intrinsic membrane protein, resident in the Golgi apparatus of certain cells. Moreover, they enhance the hypothesis that the distribution of enzymes and polypeptides in the Golgi apparatus is cell specific.

Detection of plasma cell immunoglobulins in tissue sections optimally fixed for ultrastructural immunocytochemistry.

We describe the ultrastructural localization of plasma cell immunoglobulins in vibratome sections of popliteal lymph nodes. Fixation with glutaraldehyde-paraformaldehyde gave better tissue and antigen preservation than paraformaldehyde or periodic acid lysine-paraformaldehyde; biotinylated Fab fragments of sheep anti-mouse IgG-streptavidin-biotinylated horseradish peroxidase (HRP) or Fab-HRP conjugates gave similar results. With both immunoreagents, excellent tissue preservation and antigen detection was observed in the first layer of cells sectioned with the vibratome. Conjugates of anti-mouse IgG with HRP did not show any staining. Peroxidase stain was observed in the nuclear envelope, cisternae of the rough endoplasmic reticulum, and the Golgi apparatus complex. In the Golgi apparatus, staining was seen consistently in cisternae of the cis face and in adjacent vesicles; the trans cisternae showed weak or no stain, and adjacent vesicles, "coated" vesicles, and granules were not stained. This study shows that high quality of tissue preservation and antigen detection, by both light and ultrastructural immunocytochemistry, is feasible in tissue fixed with glutaraldehyde-paraformaldehyde followed by vibratome sectioning and immunostaining with Fab-biotin-streptavidin-biotin-HRP, or Fab-HRP.

Immunocytochemical visualization of the Golgi apparatus in several species, including human, and tissues with an antiserum against MG-160, a sialoglycoprotein of rat Golgi apparatus.

We used a monoclonal antibody (10A8), derived from mice immunized with fractions enriched in Golgi apparatus of rat brain neurons, to isolate an intrinsic membrane sialoglycoprotein of 160 KD from rat brain. By immunoelectron microscopy the sialoglycoprotein, named MG-160, was localized in medical cisternae of the Golgi apparatus of neurons, glia, adenohypophysis, and cultured rat pheochromocytoma (PC 12). The monoclonal antibody (MAb) reacted only with rat tissues. Because the epitope(s) recognized by a monoclonal antibody may be restricted, localization of an antigen by a single MAb may not reflect the extent of the distribution of antigen in various species and tissues. Therefore, to further investigate the presence and localization of MG-160 or of an antigenically related protein in several species and tissues, we used a polyclonal antiserum raised against MG-160 purified by antibody (10A8) affinity chromatography. Immunoblots of crude microsomal fractions from rat brain probed with the antiserum against MG-160 showed two to three prominent bands of approximately 160, 150, and 68 KD. Immunoblots of crude microsomal fractions from human, chicken, and frog brains showed prominent bands of 130-140 and 68 KD. Immunoblots of crude membrane fractions from Saccharomyces cerevisiae showed prominent bands of approximately 110-120 and 80 KD. Light microscopic immunocytochemical studies with frog, chicken, mouse, rat, rabbit, bovine, and human brains and with several other rat and human tissues showed a staining pattern consistent with the Golgi apparatus. Immunoelectron microscopy with rat and human brain and with rat myocardium and pituitary showed prominent and exclusive staining of cis, medial, and occasionally trans cisternae of the Golgi apparatus. The cisternae of the trans Golgi network were not stained. These findings are consistent with the hypothesis that a polypeptide related to MG-160 is present in the Golgi apparatus of several tissues in human, rodents, chicken, and frog and possibly in Saccharomyces cerevisiae. The antiserum to MG-160 represents a reliable reagent for immunohistochemical visualization of the Golgi apparatus in brain and several other human tissues obtained at autopsy, fixed with Bouin's, and embedded in paraffin.