Towards quality assurance of the sentinel node procedure in malignant melanoma patients: a single institution evaluation and a European survey

The status of the regional lymph node (LN) is a critical component in staging patients with malignant melanoma. Biopsy of the first tumour-draining LN (sentinel node, SN) may replace routine elective LN dissection. However, until now, the applied methods have differed widely. Therefore, the aim of this study was to formulate recommendations for the pre-operative identification and intra-operative retrieval of the SN. We present the results of an independent survey of the clinical practice of the SN procedure via a postal questionnaire among 136 nuclear physicians in different institutes throughout 16 European countries. Moreover, the results of the SN procedure in our institution in an open prospective intervention trial in 80 patients with malignant melanoma without palpable LNs are also presented. In our protocol, on average, 6 h prior to surgery, 80 MBq technetium-99m nanocolloid was injected intracutaneously around the circumference of the diagnostic excision scar of the primary melanoma. No additional blue dye procedure was used to judge the accuracy of the radioguided SN procedure on its own. For successful identification of the radiolabelled SN, dynamic and static images were performed and the skin projection of the detected SN was marked with a cobalt-57 source. For intra-operative mapping a hand-held gamma probe was used. Forty of the 83 respondents of the European-wide questionnaire (48%) performed the SN procedure. Although many different regimens are used, the following recommendations could be deduced for the SN procedure in patients with malignant melanoma and non-palpable LNs: (1) local, intradermal injection of 40 MBq 99mTc-nanocolloid around the diagnostic excision scar of the primary melanoma; (2) two-phase LS: dynamic imaging (20 frames of 60 s, 128x128 matrix, LEAP collimator) followed by static images 1-2 h later (180 s per record); (3) intra-operative retrieval of the SN with a gamma probe; (4) histopathological examination of the SN on serial sections. In our trial, surgical retrieval of the SN was successful in 95% of the cases. Dynamic lymphoscintigraphy (LS) contributed to the SN procedure by showing anatomically unpredictable lymph flow to extra-regional SNs (10% of the patients in this study) and multiple SNs. Of the 77 retrieved SNs, 13 contained metastatic disease (17%). Consequently, these patients underwent a formal LN dissection of the affected basin. In conclusion, the SN concept is a rational approach to select patients who could, theoretically, benefit from early LN dissection of the affected basin. Standardisation of the SN procedure will improve the results of this approach, and could be useful for quality control and for making comparisons with other countries in coming years.

Severe hepatic dysfunction after adenovirus-mediated transfer of the herpes simplex virus thymidine kinase gene and ganciclovir administration

The use of so-called 'suicide' genes to activate prodrugs has been effective in animal models for several solid tumor types and is now in phase I and II clinical trials. We have exploited adenovirus vectors (Ad) for transfer and expression of the herpes simplex virus thymidine kinase (HSVtk) gene to render rat colorectal liver metastases sensitive to the anti-herpetic agent ganciclovir (GCV). The efficacy and toxicity of this enzyme-prodrug combination were tested after in situ transduction of rat colorectal tumor cells and after intraportal administration of the vector Ad.CMV.TK. Our results demonstrate the validity of the approach but reveal that hepatic expression of HSVtk, both in tumor bearing and in tumor-free rats, provokes severe liver dysfunction and mortality upon GCV administration. These data show, that in contrast to the common assumption, normally non-mitotic tissues too, can be affected by adenovirus-mediated HSVtk transfer and subsequent GCV treatment. Given the hepatotropic nature of systemically administered adenovirus type 2- and 5-derived vectors, it will be essential to monitor liver functions of patients included in all gene therapy trials involving adenoviral vectors with the HSVtk gene.

Isolated hepatic perfusion with tumor necrosis factor alpha and melphalan: experimental studies in pigs and phase I data from humans

We report our experience with isolated hepatic perfusion (IHP) with tumor necrosis factor (TNF) and melphalan in an experimental pig study and of a phase I study in humans. IHP was performed with inflow catheters in the hepatic artery and portal vein and an outflow catheter in eh caval vein. An extracorporeal venovenous bypass was used. IHP consisted of a 60-min perfusion with hyperthermia (> 41 degrees C). For the pig protocol rhTNF alpha 50 micrograms/kg alone (n = 5) or rhTNF alpha 50 micrograms/kg plus melphalan 1 mg/kg (n = 3) were added. In two control pigs no drugs were added. In the phase I study, patients received melphalan 1 mg/kg with 0.4 mg rhTNF alpha (n = 8) or 0.8 mg rhTNF alpha (n = 1). After the perfusion the liver was washed with Macrodex before vascular continuity was restored. All pigs but one survived the procedure. Systemic leakage was less than 0.02%. Transient, mild liver toxicity was seen in all pigs, including controls, as demonstrated by liver enzyme assays and histology. There was no significant hemodynamic, cardiopulmonary hematological, or renal toxicity. In the phase I clinical study there was leakage in one patient (cumulative leakage 20%). There were three perioperative deaths (one possibly drug-related). All patients demonstrated significant hepatotoxicity. Survival ranged from 6 to 26 months (median 10.3 months). All patients demonstrated a tumor response (partial response 5/6, 1/6 stable disease) with a median duration of 18 weeks. In contrast to our pig program, many problems were encountered in the phase I study. By using both the hepatic artery and portal vein for IHP we encountered more toxicity than expected based on data from the pig program, resulting in fatal coagulative disturbances in one patient who received the second rhTNF alpha dose. Furthermore, local control after one IHP with TNF alpha and melphalan is only temporary.

Observations on initial cell loss after intraportal hepatocyte transplantation of 5'-bromo-deoxy-uridine-labeled hepatocytes

In the present study, attempts are made to improve posttransplant survival of intraportally transplanted hepatocytes in a syngeneic hepatocyte transplantation (HTX) model. Engrafted hepatocytes were detected and quantified after pretransplant labeling with 5'-bromo-deoxy-uridine. In order to enhance the survival percentage, three mechanisms that possibly influence cell survival were manipulated: (1) administration of Matrigel (extracellular-matrix components, Matrigel Basement Membrane Complex, Micronic BV, Lelystad, The Netherlands) in order to improve the environmental conditions of the transplanted hepatocytes; (2) immunosuppression of the recipients by 5 Gy total body irradiation and cyclosporin-A administration (25 mg/kg, 3 x weekly), and (3) Kupffer cell depletion by injection of dichloromethylene-diphosphonate-filled liposomes. The results were analyzed in relation to HTX without treatment. Cell survival was approximately 14% (10 days after HTX), and the transplanted hepatocytes were distributed equally throughout the various recipient liver lobes. However, no increase was attained by Matrigel coadministration, immunosuppression, or Kupffer cell depletion.

Blocking of alpha 1 beta 1 integrin strongly improves survival of hepatocytes in allogeneic transplantation

The survival rate of hepatocytes after allogeneic hepatocyte transplatation (HTX) is low, possibly because of formation of intravascular hepatocyte aggregates. The aim of this study was to determine the role of integrins in intravascular aggregation and intraparenchymal survival of transplanted hepatocytes in a fully allogeneic rat model. First, the expression profile of various integrins was determined on both isolated hepatocytes in vitro and on hepatocyte aggregates in recipient livers after intraportal transplantation of allogeneic hepatocytes. Next, the role of these integrins in hepatocyte aggregation was determined in an in vitro attachment assay on liver sections with function-blocking anti-integrin monoclonal antibodies (mAb). The results showed that anti-alpha 1 beta 1 integrin mAb significantly block hepatocyte attachment to vessel walls and liver parenchyma in vitro. Subsequently, the effect of preincubation of hepatocytes with anti-integrin mAb on their intravascular aggregation and on intraparenchymal survival was studied in an allogeneic HTX model. Preincubation with anti-leukocyte function-associated antigen-1 alpha or anti-beta 2 mAb significantly intravascular hepatocyte aggregation, and anti-leukocyte function-associated antigen-1 alpha mAb enhanced intraparenchymal survival. Preincubation with anti-alpha 1 or anti-beta 1 mAb did not inhibit aggregation but significantly improved survival from 2% to up to 45% at Day 2 after transplantation (p < 0.001). In conclusion, our results suggest that the blocking of alpha 1 beta 1 integrin significantly improves survival of allotransplanted hepatocytes.

[Towards safer and parenchyma-conserving liver resections: experience with three-dimensional reconstructions of spiral CT scan]

New techniques are available for the diagnosis and treatment of liver metastases. Three patients, a male aged 52 and two females aged 70 and 47, developed liver metastases after resection of a colorectal carcinoma. Spiral CT scanning made possible detailed three dimensional imaging of the liver to determine the extension of the metastases and the site of the metastasis in relation to blood vessels and bile ducts. This enabled the surgeon preoperatively to arrive at a balanced operation strategy, with the objectives of radical resection of the metastasis and conservation of sufficient residual liver tissue with minimal morbidity and mortality. In addition, use was made of peroperative clamping of blood vessels to determine the possibility of resecting along anatomical borders. This offers the advantages that less blood is lost and a smaller resection often suffices. In the 3 patients followed respectively a wedge excision of the tumour, a wedge excision combined with a hemihepatectomy and a resection of two segments.

Hepatic lesions: detection with ferumoxide-enhanced T1-weighted MR imaging

PURPOSE

To compare the use of ferumoxide-enhanced T1-weighted gradient-echo (GRE) MR imaging with that of spiral computed tomography during arterial portography (CTAP) and T2-weighted Turbo spin-echo (SE) MR imaging in detection of lesions and of segmental involvement in patients with liver metastases.

MATERIALS AND METHODS

Twenty-two candidates for metastasectomy of the liver underwent spiral CTAP, ferumoxide-enhanced GRE MR imaging, and T2-weighted Turbo SE MR imaging. A total of 176 liver segments were evaluated (57 with and 119 without metastases). The reference standard was laparoscopic sonographic findings. Diagnostic performance of the imaging modalities was assessed for lesion detection and determination of segmental involvement.

RESULTS

The sensitivity for lesion detection with spiral CTAP, ferumoxide-enhanced MR imaging, and T2-weighted MR imaging was 0.96, 0.83, and 0.71, respectively; for segmental analysis, the sensitivity was 0.96, 0.84, and 0.75, respectively, and the specificity was 0.80, 0.99, and 0.92, respectively. All comparisons between sensitivities and specificities were statistically significant (P < .05).

CONCLUSION

Ferumoxide-enhanced T1-weighted GRE MR imaging is superior to T2-weighted SE MR imaging for preoperative detection of lesions and segmental involvement in patients with liver metastases.

Monitoring engraftment of transplanted hepatocytes in recipient liver with 5-bromo-2'-deoxyuridine

For studies on the intrahepatic engraftment of transplanted hepatocytes, labeling of donor cells is necessary. Current labeling techniques enable only short-term monitoring of engraftment. In the present study, we describe the use of 5-bromo-2'-deoxyuridine (BrdU) for a more permanent hepatocyte labeling. BrdU is stably incorporated into replicating DNA; consequently, BrdU labeling was performed in regenerating livers. In 10 Lewis rats, a two-thirds partial hepatectomy was performed, followed by continuous, low-dose BrdU administration. This approach provided a fraction of 89+/-1.5% BrdU-labeled donor hepatocytes, without influencing the efficacy of the ensuing isolation of donor hepatocytes. Subsequently, +/-1 x 10(7) isolated hepatocytes were transplanted either intraportally or intrasplenically into syngeneic recipients, and the engraftment of transplanted cells was evaluated in liver lobes at successive time intervals after transplantation. BrdU-positive hepatocytes could be identified and quantitated in recipient livers up to 180 days after transplantation. Repetitive quantitative assessments over time revealed an initial, drastic loss of transplanted cells (<24 hr), followed by a stabilization at approximately 7% of the injected cells. Histological monitoring showed that during this period (<48 hr) the transplanted cells migrate from the portal venules to the liver parenchyma. In recipient livers a homogeneous lobe distribution of hepatocyte engraftment was found 30 days after both intraportal and intrasplenic transplantation. Moreover, no significant difference between the intrahepatic liver cell engraftment of the two transplantation routes was demonstrated. In conclusion, the BrdU-labeling technique of donor hepatocytes enables long-term histological monitoring and quantitative evaluation of the engraftment of transplanted liver cells in recipient livers.

The diagnostic accuracy of core biopsy in palpable and non-palpable breast lesions

OBJECTIVE

To assess the accuracy of large-core needle biopsy in evaluating palpable and nonpalpable breast lesions.

METHODS AND PATIENTS

Stereotaxic and ultrasound (US) guided core biopsies were performed in 103 breast lesions in 97 patients. Subsequently, all patients underwent surgery. All specimens (core biopsy and surgical) underwent radiography for evaluation of microcalcifications. The histopathologic findings of the core biopsies and the surgical specimens were correlated.

RESULTS

Core biopsies and surgery findings were concordant in 100% of the 27 palpable lesions and in 89% of the 76 nonpalpable lesions. One case of malignancy, ductal carcinoma in situ (DCIS), was not diagnosed by core biopsy. In 102 (99%) of the 103 breast lesions, a correct choice for additional diagnostic procedure or definitive treatment could have been made upon histopathologic findings of core biopsy.

CONCLUSION

Stereotaxic and ultrasound-guided core biopsy are safe, reliable and less traumatic than excisional biopsy. Special attention is necessary when atypical ductal hyperplasia (ADH) or DCIS without invasive carcinoma is found. Radiography of the biopsy specimens for detection of microcalcifications is essential.

Isolated hepatic perfusion in the pig with TNF-alpha with and without melphalan

Isolated limb perfusion with tumour necrosis factor alpha (TNF-alpha) and melphalan is well tolerated and highly effective in irresectable sarcoma and melanoma. No data are available on isolated hepatic perfusion (IHP) with these drugs for irresectable hepatic malignancies. This study was undertaken to assess the feasibility of such an approach by analysing hepatic and systemic toxicity of IHP with TNF-alpha with and without melphalan in pigs. Ten healthy pigs underwent IHP. After vascular isolation of the liver, inflow catheters were placed in the hepatic artery and portal vein, and an outflow catheter was placed in the inferior vena cava (IVC). An extracorporeal veno-venous bypass was used to shunt blood from the lower body and intestines to the heart. The liver was perfused for 60 min with (1) 50 microg kg(-1) TNF-alpha (n = 5), (2) 50 microg kg(-1) TNF-alpha plus 1 mg kg(-1) melphalan (n = 3) or (3) no drugs (n = 2). The liver was washed with macrodex before restoring vascular continuity. All but one pigs tolerated the procedure well. Stable perfusion was achieved in all animals with median perfusate TNF-alpha levels of 5.1 +/- 0.78 x 10(6) pg ml(-1) (+/- s.e.m). Systemic leakage of TNF-alpha from the perfusate was consistently < 0.02%. Following IHP, a transient elevation of systemic TNF-alpha levels was observed in groups 1 and 2 with a median peak level of 23 +/- 3 x 10(3) pg ml(-1) at 10 min after washout, which normalized within 6 h. No significant systemic toxicity was observed. Mild transient hepatotoxicity was seen to a similar extent in all animals, including controls. IHP with TNF-alpha with(out) melphalan in pigs is technically feasible, results in minimal systemic drug exposure and causes minor transient disturbances of liver biochemistry and histology.

Liver and tumour tissue concentrations of TNF-alpha in cancer patients treated with TNF-alpha and melphalan by isolated liver perfusion

In this study we determined the level of tumour necrosis factor alpha (TNF-alpha) in liver and tumour tissue samples obtained from patients with colorectal metastases confined to the liver, who were treated with isolated liver perfusion with TNF-alpha and melphalan. We adapted a standard enzyme-linked immunosorbent assay kit for the quantification of TNF-alpha in serum to measure the amount of this cytokine in solid tissue. For this purpose, we developed a buffer that lysed the tissues without affecting the TNF-alpha present. The minimum detection level was about 2 pg of TNF-alpha per mg tissue. Using this technique, we found a significant increase in the TNF-alpha level after perfusion in the liver tissue of all evaluable patients, which may explain the transient liver toxicity we observed in all patients. In tumour tissue, a significant TNF-alpha increase was observed in one out of five patients. The level of TNF-alpha in all liver tissue samples and some of the tumours after treatment by isolated liver perfusion was much higher than the peak serum concentrations obtained after systemic administration of the maximum tolerated dose of TNF-alpha. Furthermore, we demonstrated that the level of TNF-alpha in the liver tissue samples was about seven to eight times higher than in tumour tissue. We concluded that regional liver treatment resulted in a relatively high local level of TNF-alpha, but also that this cytokine did not preferentially accumulate in tumour tissue.

Gas explosion during colonic surgery

Explosions of the colon as a result of the use of diathermy in the presence of gas mixtures of oxygen, hydrogen and/or methane have been previously described in the literature. This danger is present during colonoscopic polypectomy as well as during colonic surgery. The following case is presented to alert to the potential hazards of bowel gas during electrosurgery.

Correction of an inborn error of metabolism by intraportal hepatocyte transplantation in a dog model

The aims of this study were (1) to assess portal hemodynamics during intraportal hepatocyte transplantation (HTX) in dogs, (2) to evaluate a new method for the detection of transplanted hepatocytes using 5-bromo-2'-deoxyuridine (BrdU) incorporation, and (3) to determine the metabolic effects of HTX on an inborn error of the purine metabolism in dalmatian dogs. HTX was performed by intraportal infusion of freshly isolated allogeneic beagle hepatocytes. Portal flow and pressure were monitored continuously during HTX. For the detection experiments, beagles received hepatocytes that had been exposed to BrdU during regeneration of the donor liver, induced by partial hepatectomy. For metabolic studies, dalmatian dogs were used as recipients. Repetitive HTX was performed. As judged by the portal hemodynamics, the number of hepatocytes that could be infused safely varied from 5 x 1O(8) to 8 x 1O(8) in beagles, to 1 x 10(9) in dalmatians. Transaminase levels showed a 5- to 6-fold increase (P=0.05) after HTX, but normalized within 3 weeks. BrdU-positive cells were identified in the recipient livers 2 weeks after HTX and 5-10% of the total amount of transplanted hepatocytes was retrieved. A significant (P=0.05) decrease in serum uric acid was demonstrated after repeated HTX in dalmatians. In conclusion, (1) intraportal HTX is feasible, but portal hypertension limits the maximum amount of hepatocytes that can be infused in one HTX; (2) BrdU labeling is an attractive method for the detection of transplanted hepatocytes in the recipient liver; and (3) after two consecutive hepatocyte transplantations, a temporary correction of the purine metabolism was accomplished in the dalmatian dog.

[Initial results of immediate reconstruction of the breast following mastectomy]

OBJECTIVE

Evaluation of the results of immediate reconstruction after mastectomy for breast cancer by means of a silicone implant.

DESIGN

Retrospective analysis.

SETTING

Department of Surgical Oncology of the Dr Daniël den Hoed Cancer Centre and Department of Surgery of the Zuiderziekenhuis, Rotterdam, the Netherlands.

METHOD

From September 1990 till July 1993, 37 immediate reconstructions of the breast after mastectomy were performed in 35 patients by means of a silicone implant. Indications for the treatment, consequences for further oncological treatment, additional plastic surgery, and complications of the reconstruction were evaluated.

RESULTS

The indications for mastectomy and immediate reconstruction were local recurrence after breast conservative treatment (6 operations), multifocal disease (8), extensive in situ carcinoma (8), non-radically removed tumour at lumpectomy (5), anticipated poor cosmetics after breast conservative treatment (6), prophylactic ablation of the breast (2), and patient preference (1). 5 patients received adjuvant systemic chemotherapy, which could be administered without delay, and without negative influence on the result of the breast reconstruction. Additional plastic surgical treatment consisting of reconstruction of the areolar complex and correction of the breast symmetry, was performed in 5 and 3 patients respectively. In 8 of the 37 reconstructions (22%) complications were encountered. The main complications were haematoma (2), infection (4), implant removal (3), capsular contracture (2), skin necrosis (2), and luxation of the implant (1).

CONCLUSION

Immediate reconstruction after mastectomy is a valuable treatment modality in breast cancer.

Proliferative response of hepatocytes transplanted into spleen or solid support

Understanding the regenerative behavior of transplanted hepatocytes is of great importance for developing and improving such novel therapeutic strategies as hepatocellular transplantation and ex vivo gene therapy. In this study the proliferative responsiveness of transplanted syngeneic rat hepatocytes was examined in relation to the timing of the administration of a mitogenic stimulus. For this purpose nuclear bromodeoxyuridine incorporation after partial hepatectomy was investigated during the early post-transplant phase. The response of intrasplenically transplanted hepatocytes was compared to that of liver cells engrafted in polytetrafluoroethylene solid supports that had been implanted intraperitoneally 4 weeks prior to transplantation. Nonstimulated, engrafted hepatocytes exhibited a labeling index of approximately 0-1% independent of the transplantation technique used. This "spontaneous" labeling index did not change with time. Partial hepatectomy, executed simultaneously with hepatocyte transplantation through either technique, did not result in significant alteration of this proliferation index. Delayed kinetics were found not to be responsible for this lack of responsiveness. When the mitogenic stimulus was given between 2 and 6 weeks post-transplantation, a significant increase in labeling index was observed in comparison to sham-treated control animals. Maximal labeling indices of approximately 3-4% were found if the stimulus took place at 4 weeks post-transplantation. Both the pattern and the extent of the proliferative response seen in liver cells engrafted in solid supports were similar to the ones found in intrasplenic hepatocytes, indicating adequate vascularization of the supports. This data provides the first description of proliferative response in hepatocytes transplanted by the solid support technique, which may offer an attractive alternative to the intrasplenic route.(ABSTRACT TRUNCATED AT 250 WORDS)

An extracorporeal microscopy perfusion chamber for on-line studies of environmental effects on cultured hepatocytes

The development of bioartificial-hybrid organ support systems is hampered by the lack of knowledge on the effects of different (in vivo) environments on cells during extracorporeal perfusion. In the present study, a perfusion chamber was designed for continuous monitoring of cultured cells during perfusion with media, as well as during plasma perfusion in an extracorporeal circuit. Chamber characterization showed satisfactory thermal and perfusion profiles and no major pH fluctuations. Further testing was performed with hepatocytes that were cultured in between two collagen layers, a configuration which was previously shown to preserve hepatocyte morphology and function for over six weeks of culture. Perfusion of the hepatocytes with culture media did not adversely affect cell morphology and function, provided the perfusion time was < or = 48 hours. Perfusion of the cultures during connection of the chamber to an extracorporeal circuit involving normal rats for six hours resulted in reversible cytoplasmic changes, unaltered cell shapes indices, and a 40 percent increase in albumin secretion rate during the first post-perfusion day, followed by a return to stable control levels. We expect that this chamber will be a valuable tool for on-line studies of cells under (extracorporeal) perfusion conditions and could be used for a large variety of studies on regeneration, reperfusion damage, and detoxification.

Nucleation and growth of ice crystals inside cultured hepatocytes during freezing in the presence of dimethyl sulfoxide

A three-part, coupled model of cell dehydration, nucleation, and crystal growth was used to study intracellular ice formation (IIF) in cultured hepatocytes frozen in the presence of dimethyl sulfoxide (DMSO). Heterogeneous nucleation temperatures were predicted as a function of DMSO concentration and were in good agreement with experimental data. Simulated freezing protocols correctly predicted and explained experimentally observed effects of cooling rate, warming rate, and storage temperature on hepatocyte function. For cells cooled to -40 degrees C, no IIF occurred for cooling rates less than 10 degrees C/min. IIF did occur at faster cooling rates, and the predicted volume of intracellular ice increased with increasing cooling rate. Cells cooled at 5 degrees C/min to -80 degrees C were shown to undergo nucleation at -46.8 degrees C, with the consequence that storage temperatures above this value resulted in high viability independent of warming rate, whereas colder storage temperatures resulted in cell injury for slow warming rates. Cell damage correlated positively with predicted intracellular ice volume, and an upper limit for the critical ice content was estimated to be 3.7% of the isotonic water content. The power of the model was limited by difficulties in estimating the cytosol viscosity and membrane permeability as functions of DMSO concentration at low temperatures.

Retroviral infection and expression of cationic amino acid transporters in rodent hepatocytes

The susceptibility of rodent hepatocytes to infection by mouse type C retroviruses was examined in vivo and in vitro and compared with the expression of two membrane proteins that function as transporters for the cationic amino acids CAT-1 and CAT-2. CAT-1 expression in rodents determines susceptibility to ecotropic retrovirus infection by serving as the virus receptor. Recently, it has been suggested that CAT-2 may be a receptor for amphotropic murine leukemia virus. In the present study, CAT-1 expression was observed in Hepa1, a cell line derived from a murine hepatoma, and in rat hepatocytes propagated on collagen monolayers in vitro but not in intact or regenerating rat liver in vivo. The expression of CAT-1 correlated with susceptibility to infection by an ecotropic retrovirus encoding beta-galactosidase. CAT-2 expression was observed in hepatocytes in vitro and in vivo, consistent with reports of infection of regenerating and cultured hepatocytes by amphotropic retroviruses. However, introduction of murine CAT-2 into nonpermissive Chinese hamster cells was not sufficient to confer susceptibility to amphotropic retrovirus infection, using a protocol that could easily demonstrate CAT-1-dependent infection by an ecotropic virus. Our data establish CAT-1 as a major determinant of ecotropic retrovirus infection in rodent hepatocytes and suggest that CAT-2 is not a receptor for viruses in the amphotropic subgroup.

A stable long-term hepatocyte culture system for studies of physiologic processes: cytokine stimulation of the acute phase response in rat and human hepatocytes

Prior studies on the in vitro hepatic acute phase response have involved either hepatoma cell lines or conventional short-term cultures of primary hepatocytes. No data are available on the response of primary hepatocytes in stable long-term culture systems. In this study, the acute phase response of rat and human hepatocytes in a new long-term culture system was examined in response to interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta), and tumor necrosis factor alpha (TNF-alpha). The cultured cells were sandwiched between two layers of collagen in a (double-gel) configuration which has been shown to preserve both hepatocyte function and morphology over prolonged periods of time. The stability of this culture configuration enabled us to investigate, for the first time, the temporal aspects of the response in addition to the effects of the mediators on protein secretion. Exposure of rat hepatocytes to IL-6 after culture for 16 days resulted in a 2-fold reduction of albumin secretion and a 15-fold increase in the secretion rates of fibrinogen and alpha 2-macroglobulin. In all instances, the peak response occurred at 48 h after IL-6 exposure, and all protein secretion rates returned to pretreatment values within 5 days posttreatment. Changes in the mRNA levels of these proteins in response to IL-6 corresponded with those changes seen with the secreted products, indicating pretranslational regulation. Administration of IL-1 beta to rat hepatocyte produced a similar decline of albumin secretion and a 5-fold increase of fibrinogen secretion, whereas alpha 2-macroglobulin secretion remained undisturbed.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of dimethyl sulfoxide on cultured rat hepatocytes in sandwich configuration

A recently developed sandwich culture system, in which hepatocytes are sandwiched between two layers of collagen, has been shown to be capable of maintaining long-term expression of hepatocellular function (J. C. Y. Dunn et al., Biotechnol. Prog. 7, 237-245, 1991). The development of an adequate technique for the cryopreservation of hepatocytes in such a stable culture configuration would ensure a ready supply of hepatocytes for use in bioreactors or bioartificial liver support devices. This report describes the effects of exposing hepatocytes in sandwich culture to different concentrations of the cryoprotectant dimethyl sulfoxide (Me2SO) at 22 degrees C on Day 7 of culture. Cell function, morphology, and cytoskeletal organization were followed for 14 days after exposure. Hepatocellular morphology and albumin secretion remained normal when cultures were exposed for up to 120 min to predicted final Me2SO concentrations up to 1.33 M. Exposure for less than 60 min to equilibrium concentrations of up to 3.33 M Me2SO did not adversely affect cell morphology or albumin secretion rate, but at the highest concentration (3.33 M), increase of the exposure time to 60 or 120 min resulted in dramatic, irreversible cell damage and loss of function. Actin filament organization was shown to be undisturbed when the cells were exposed to 1.33 M Me2SO for 60 min, but was irreversibly disrupted by exposure to 3.33 M for 120 min. Based on these results, a simple and safe procedure is suggested for the addition of Me2SO to hepatocytes in a sandwich culture configuration and its subsequent removal, which will be valuable for studies on hepatocyte cryopreservation.

Does auxiliary heterotopic liver transplantation reverse hypersplenism and portal hypertension?

In this study, performed to assess the effect of auxiliary heterotopic liver transplantation on portal hypertension and hypersplenism, eight patients with chronic liver disease who underwent the procedure and had functioning grafts for at least 6 months were analyzed. The transplantation resulted in (a) normalization of platelet and leukocyte counts, (b) reduction of splenomegaly by 20% +/- 3% (P less than 0.02), (c) disappearance of ascites, and (d) diminution of esophageal varices in all patients. Intraoperatively, the mean portacaval pressure gradient decreased with 54% +/- 7% after recirculation of the graft (P less than 0.05). In conclusion, a functioning auxiliary heterotopic liver graft decompresses portal hypertension and reverses hypersplenism.

Treatment of manifest and impending pathologic fractures of the femoral neck by cemented hemiarthroplasty

Thirty-four patients with manifest or impending pathologic fractures of the femoral neck were treated between 1971 and 1987. Breast carcinoma was the primary tumor in the majority of patients. All patients were treated with cemented hemiarthroplasty. Twenty-seven patients (79%) could walk at an average of nine days postoperatively. All patients experienced relief of pain. Two superficial wound dehiscences, one loosening of the prosthesis, and two prosthetic dislocations were encountered. Mean survival was 17.6 months overall (12 months for manifest fractures and 40 months for impending fractures). These results indicate that cemented hemiarthroplasty for pathologic fractures is a safe procedure resulting in long-lasting palliation without necessitating postoperative irradiation. The importance of tumor excochleation and the advantages of bone cement are emphasized.