Transforming growth factor-beta is involved in the pathogenesis of dialysis-related amyloidosis

BACKGROUND

Advanced glycation end product-modified beta2-microglobulin (AGE-beta2m) is an important component of dialysis-related amyloidosis (DRA). Its presence induces monocyte chemotaxis and the release of the proinflammatory cytokines through macrophage activation. Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine that also has chemotactic activity for monocytes at very low (0.1 to 10 pg/mL) concentrations and inhibits proinflammatory cytokine production of macrophages. In this study, we investigated the role of TGF-beta in the pathogenesis of DRA.

METHODS

We performed an immunohistochemical study of DRA tissues (8 cases) to confirm the existence of TGF-betas and their receptors; we also performed a chemotaxis assay of human monocytes as well as enzyme-linked immunosorbent assay (ELISA) of TGF-beta1, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-1 receptor antagonist (IL-1Ra) in the supernatant of human monocyte-derived macrophage cell culture under varying conditions of incubation with TGF-beta1, AGE-beta2m, and TGF-beta1 antibody additions.

RESULTS

There was positive staining for TGF-betas (types 1, 2, and 3) and their receptors (types I, II, and III) in infiltrated macrophages (CD68+), synovial lining cell, as well as vascular walls around amyloid deposition. AGE-beta2m also induced TGF-beta1 production by macrophages in a dose-dependent manner (410 +/- 80 pg/mL at 12.5 microg/mL, 621 +/- 62 pg/mL at 25 microg/mL, and 776 +/- 62 pg/mL at 50 microg/mL of AGE-beta2m). AGE-beta2m induced significant TNF-alpha and IL-1Ra production by macrophage. The addition of exogenous TGF-beta1 (0.1 to 10 ng/mL) decreased AGE-beta2m-induced TNF-alpha production and increased IL-1Ra production in a dose-dependent fashion. IL-1beta production was not effected by any experimental conditions. In chemotaxis assay, anti-TGF-beta1 antibody (0.1 to 10 microg/mL) attenuated AGE-beta2m-induced monocyte chemotaxis.

CONCLUSIONS

These results provide the first evidence to our knowledge for the presence of TGF-beta in DRA tissue, as well as the stimulatory action of AGE-beta2m on tissue macrophages. In turn, TGF-beta suppresses the proinflammatory activation of macrophages, suggesting a dual role for TGF-beta in the inflammatory process of DRA. These observations may provide a pathophysiologic link between TGF-beta and DRA.

Effects of a parathyroidectomy on the immune system and nutritional condition in chronic dialysis patients with secondary hyperparathyroidism

BACKGROUND

Parathyroid hormone (PTH) has an adverse effect on the immune system and may cause immunologic disorders in patients with chronic renal failure. The in vivo effects of a parathyroidectomy on the immunologic parameters was examined.

METHODS

Thirty-four patients under dialysis therapy received a parathyroidectomy (PTx) for secondary hyperparathyroidism (HPT). They were prospectively studied regarding serum immunoglobulins, complements, CD markers, and serum soluble IL-2 receptor (sIL-2R) until 12 months after PTx.

RESULTS

The serum levels of IgG, IgA and IgM showed significant increase until 12 months after PTx (P<0.001, respectively). C3, C4, and CH50 also indicated significant increase at 12 months after PTx. In cellular immunity, only serum sIL-2R showed significant increase 2 weeks after PTx (P = 0.028). The hematocrit and serum albumin also improved significantly at 12 months.

CONCLUSIONS

PTx showed beneficial effects on humoral immunological markers. The effects are probably due to the remarkable PTH reduction and partly improved nutritional state after PTx.

Coinfection of Spodoptera exigua and Spodoptera frugiperda cell lines with the nuclear polyhedrosis viruses of Autographa californica and Spodoptera exigua

The Autographa californica multinucleocapsid nuclear polyhedrosis virus (AcMNPV) has a broad host range among Lepidoptera. In contrast, the Spodoptera exigua MNPV (SeMNPV) can replicate efficiently only in S. exigua larvae or S. exigua-derived cell lines. In this study, we examined the coinfection of S. exigua Se301 and Spodoptera frugiperda IPLB-SF21AEII (Sf21) cell lines with SeMNPV and AcMNPV recombinant (Ac360-501beta-gal) which was constructed for expression of beta-galactosidase under control of the polyhedrin promoter. Coinfection led to the restriction as the level of late gene expression, nonoccluded virus production, and DNA replication of Ac360-501beta-gal in both Se301 and Sf21 cell lines. In contrast, Ac360-501beta-gal supported the SeMNPV replication in Sf21 cells. Occurrence of recombinants, between Ac360-501beta-gal and SeMNPV, with expanded host range was not observed in coinfected Sf21 cells. This suggests that Ac360-501beta-gal supports the SeMNPV replication through trans-activation.

Acute renal failure due to hypokalemic rhabdomyolysis in Gitelman's syndrome

A 46-year-old-male developed acute renal failure (ARF) secondary to hypokalemic rhabdomyolysis. Potassium supplementation restored renal function following improvement of the rhabdomyolysis. After recovery from ARF, further evaluation disclosed he had hypokalemic metabolic alkalosis, normotensive hyperreninemia, hyperaldosteronism, renal hypomagnesemia, hypocalciuria and hyperplasia of the juxtaglomerular apparatus which are a diagnostic set of disorders in Gitelman's syndrome, a variant of Bartter's syndrome. This is the first reported case of ARF due to hypokalemic rhabdomyolysis associated with Gitelman's syndrome.

Replication of Spodoptera exigua nucleopolyhedrovirus in permissive and non-permissive lepidopteran cell lines

The Spodoptera exigua multinucleocapsid nucleopolyhedrovirus (SeMNPV) was inoculated to eight lepidopteran cell lines derived from Spodoptera exigua (Se301), Spodoptera frugiperda (SF21AEII), Spodoptera littoralis (CLS-79), Spodoptera litura (SpLi-221), Pseudaletia separata (LeSe-11), Trichoplusia ni (hi-5), Plutella xylostella (PXL/C) and Bombyx mori (BmN4). The productive infection of SeMNPV was observed only in Se301 cells. However, a dot-blot hybridization analysis revealed that SeMNPV DNA replicated in five non-permissive cell lines: SF21AEII, CLS-79, SpLi-221, hi-5 and BmN4. In addition, the virus-infected hi-5 and BmN4 cells displayed morphological changes. In contrast, CLS-79 cells inoculated with SeMNPV showed membrane blebbing at 20 hrs post inoculation (p.i.) and fragmentation of genomic DNA. All that indicated that the infected CLS-79 cells underwent apoptosis. These findings indicate that the SeMNPV replication was restricted at various points in dependence upon each cell line.

Early development of Epstein-Barr virus-associated T-cell lymphoma after a living-related renal transplantation

We herein report a case of Epstein-Barr virus (EBV)-associated T-cell lymphoma that developed within a month after a kidney transplantation. The recipient was a 37-year-old man who had evidence of a previous EBV infection. Cyclosporine, methylprednisolone, and azathioprine were used for immunosuppression, and acute rejection was treated with high-dose methylprednisolone. The lactate dehydrogenase level started to increase on day 24 and thereafter peaked on day 37 while also demonstrating progressive jaundice and a bleeding tendency. A transplant nephrectomy was done on day 37; however, the patient could not recover and eventually died of respiratory failure as a result of diffuse pulmonary edema. A pathological examination of the resected kidney revealed a diffuse proliferation of large atypical lymphoid cells in the parenchyma. Immunohistochemically, the tumor cells were positive for CD45 and T-cell marker, CD45RO, but negative for B-cell markers. EBV-encoded RNA was demonstrated within the neoplastic cells by in situ hybridization.

Echocardiographic evaluation in long-term continuous ambulatory peritoneal dialysis compared with the hemodialysis patients

In dialysis patients, the prevalence of severe left ventricular (LV) hypertrophy and systolic failure, important predictors of cardiovascular morbidity and mortality, has been reported to be very high. Therefore, we investigated cardiac function in 17 long-term CAPD patients (dialysis duration: 76.5 +/- 13.2 months; L-CAPD) by echocardiography and pulsed Doppler, and then compared with 16 short-term CAPD patients (dialysis duration: 28.9 +/- 11.9 months; S-CAPD), 21 long-term hemodialysis patients (dialysis duration: 165.1 +/- 52.7 months; L-HD), and 22 short-term hemodialysis patients (dialysis duration: 71.3 +/- 28.9 months; S-HD), except for the cases with diabetes mellitus, ischemic heart disease, cardiac surgery or overt congestive heart failure. We selected 13 normotensive patients with normal kidney function as normal control group matched for sex and age (Control). Concerning with L-CAPD, S-CAPD, L-HD, and S-HD, these four groups were matched for age and original diseases. We examined blood pressure (BP), cardiothoracic rate (CTR), antihypertensive (AHT) drugs and laboratory data. Wall thickness, left atrium, ventricular chamber size, ejection fraction (EF) and left ventricular mass (LV mass) [Devereux et al. 1986] were measured by echocardiograph. Peak early diastolic flow velocity (E), peak atrial filling velocity (A), A/E ratio and deceleration time of peak early diastolic flow velocity (DT) were calculated by analyzing transmitral flow, recorded by pulsed Doppler. BP control, CTR and EF were significantly worse in L-CAPD than in other patient groups. A/E as one of parameters for cardiac diastolic function was significantly higher in L-CAPD than in HD patients. LVMI (LV mass index: LV mass/body surface area) was significantly higher in L-CAPD than in other groups. LVMI in CAPD patients was shown to be significantly worse as time goes. Volume control by itself without AHT drugs could achieve good BP control in the long-term CAPD patients who were changed to maintenance hemodialysis because of peritoneal sclerosis. We concluded that LV hypertrophy and systolic dysfunction tend to progress in CAPD patients as time goes on. Also it is suggested that the cause of cardiac dysfunction in CAPD patients was mainly based on poor BP control probably due to overhydration, and therefore, appropriate volume control in CAPD patients is especially important.

Properties of a new picorna-like virus of the brown-winged green bug, plautia stali

A picorna-like virus was isolated from the brown-winged green bug, Plautia stali. The virus was named Plautia stali intestine virus (PSIV) based on the multiplication site of the virus in the infected insects. PSIV is a spherical particle with a diameter of 30 nm. Particles of PSIV were found to contain a 9.1-kb single-stranded RNA. Polyacrylamide gel electrophoresis of purified PSIV particles revealed three major (33, 30, 26 kDa), one medium (35 kDa), and one minor (4.5 kDa) structural proteins. The molar ratios of the proteins suggested that the 35-, 33-, 30-, 26-, and 4.5-kDa proteins corresponded to VP0, VP1, VP2, VP3, and VP4 of vertebrate picornaviruses. Immunological assays indicated that PSIV and Nezara viridula virus-1, which is a picorna-like virus of the green stinkbug in South Africa, were serologically distinct. PSIV was detected in the intestine with enzyme-linked immunosorbent assay but not in the salivary glands, fat bodies, Malpighian tubules, and reproductive organs of viruliferous P. stali. The virus was also detected on the surface of the eggs and in the feces of infected insects. These results suggest that excrement of infected insects are the primary inoculum of the virus in a colony of P. stali. The nonviruliferous adults of P. stali usually survive a few months in laboratory, while the average of adulthood lifetime in viruliferous P. stali was about 13 days. PSIV also infected two other stinkbugs, Nezara viridula and Halyomorpha halys. Copyright 1998 Academic Press.

Systemic lupus erythematosus in a patient with remitting minimal change nephrotic syndrome

Minimal change nephrotic syndrome (MCNS) developed in a 17-year-old female and spontaneously remitted. One month later the nephrotic syndrome relapsed. Prednisolone therapy, 60 mg/day, was started and resulted in a full remission within a week and the prednisolone dose was subsequently tapered. Seven months later, when 10 mg/day of prednisolone was being administered, she developed erythematous rash with photosensitivity and polyarthralgia without exacerbation of the nephrotic syndrome, and fulfilled four of the American College of Rheumatology criteria for classification of systemic lupus erythematosus (SLE). Avoidance of direct sunlight ameliorated the erythematous rash and the polyarthralgia disappeared even though the prednisolone dose was decreased further. This is the first reported case of SLE developed in a patient with remitting MCNS.

Acute hemorrhagic gastritis associated with acetazolamide intoxication in a patient with chronic renal failure

Acetazolamide (Diamox) is a carbonic anhydrase inhibitor commonly used in patients with glaucoma in order to reduce intraocular pressure. Acetazolamide (AZ) is mostly excreted in the urine, therefore, the blood levels of AZ often tend to increase in patients with chronic renal failure. We experienced a case of chronic renal failure in a patient suffering from acute hemorrhagic gastritis associated with AZ intoxication. A 66-year-old female with chronic renal failure was referred to our hospital because of drowsiness and an acute deterioration of renal function. She had been treated with AZ, 500 mg per every day for eleven days for the treatment of glaucoma. Laboratory studies showed leukocyturia, thrombocytopenia, severe anemia, and tarry stools. The serum concentration of AZ was elevated to a maximum of 76.5 mg/ml. She was thus diagnosed as having AZ intoxication. On further examination, acute extensive hemorrhagic gastritis was also found by gastroscopy. Despite of the administration of intensive therapies, she died of disseminated intravascular coagulation (DIC) and septic shock due to bone marrow depression 6 days after admission. It is generally known that excessive blood levels of AZ inhibit not only the gastric juices but also prostaglandin levels and HCO3- excretion in the gastric mucosal barrier. We thus concluded that an excessive dose of AZ had probably destroyed the gastric mucosal barrier or thrombocytopenia due to bone marrow disorder and thus eventually led to the development of hemorrhagic gastritis. As far as we know, this is the first case report of acute hemorrhagic gastritis associated with AZ intoxication. Even though AZ tends to strongly bind to plasma protein and its clearance is generally poor by hemodialysis (HD), in our patient, HD was observed to be rather effective since the clearance of AZ was 45.8 ml/min on HD and 66 ml/min on direct hemoperfusion (DHP). DHP often reduces the number of platelets, also DHP needs a lot of heparin, therefore, we should have performed HD alone instead of DHP. In patients with an impaired renal function, AZ should therefore be administered very carefully in order to avoid an accumulation of the drug. In addition, HD alone should be used to remove any excessive amounts of AZ from the blood.

Dialysis-related amyloidosis of the tongue in long-term hemodialysis patients

Dialysis-related amyloidosis (DRA) predominantly occurs in the osteoarticular structures. However, according to studies in the increasing number of long-term hemodialysis patients, DRA has also been systemically found to appear in the other tissues and organs as well. In this study, we investigated lingual amyloidosis in relation to systemic DRA. A total of 472 patients were studied who were on regular hemodialysis for more than 10 years, including 103 patients for more than 20 years. Eight of these patients (7 males and 1 female, mean age 59 +/- 8 years, range 46 to 68 years) developed lingual amyloidosis, seemingly as a result of beta2-microglobulin (beta2m) deposits. All patients demonstrating lingual amyloidosis had been treated with regular hemodialysis for more than 20 years (mean HD duration 23.6 +/- 1.4 years), and its morbidity was 7.8% in the 103 patients and 20% (6 patients) in the 30 patients treated for more than 23 years with hemodialysis. Hemodialysis (HD) duration with bioincompatible unsubstituted cellulose membranes in the 8 patients was longer than that in the control group without lingual amyloidosis (P < 0.05). Lingual amyloid nodules were whitish-yellow in color and varied in size, at least over 1 mm in diameter. Their consistency was firmer than the intact tongue. The location of the amyloid nodules could be classified into two types: (1) diffuse type (diffusely distributed over the tongue), and (2) lateral type (localized only in the lateral side of the tongue). Five of the eight patients with lingual amyloidosis complained of functional disturbances in the tongue, such as abnormal taste, or difficulty in mobility and articulation. No macroglossia was observed in any of these cases. It was thus concluded that DRA of the tongue is a very rare complication, occurring in the late stage of long-term hemodialysis patients, that disturbs their quality of life.

Laparoscopic splenectomy for splenic hamartoma

Advances in imaging techniques have made pre-operative diagnosis of splenic tumors possible. A case of successful laparoscopic splenectomy for splenic hamartoma is described here and the indications of this technique are discussed.

Superficial repositioning of the artery for chronic hemodialysis: indications and prognosis

Superficial repositioning of the artery (SRA) is a modality of the blood access operation for chronic hemodialysis that has been previously used in cases of cardiac failure. We performed 42 SRAs from 1986 to 1993; thereafter, we retrospectively investigated the operative indications, postoperative complications, and long-term results. Superficial repositioning of the artery was indicated for the lack of an appropriate vein (17 cases; 40%), frequent and early access failure due to arteriovenous fistula or polytetrafluoroethylene grafts (six cases; 14%), venous hypertension (five cases; 12%), and cardiac failure (two cases; 5%). The patency rates of the SRAs were 87% at 3 years and 58% at 4.5 years. There was some difficulty in finding the returning veins in five of 28 functioning SRAs (18%). The SRA is thus considered to be a secondary-selected blood access operation; however, it also may be used as an efficient blood access for an extended period of time without any serious complications.

The use of a pig liver xenograft for temporary support of a patient with fulminant hepatic failure

A 26-year-old female patient with fulminant hepatic failure and a history of autoimmune hepatitis was heterotopically transplanted with a pig hepatic xenograft to provide temporary metabolic support prior to transplantation with a human donor organ. Circulating natural antipig antibodies were removed prior to transplantation by plasmapheresis and ex vivo en bloc perfusion of the donor pig kidneys. The liver xenograft functioned after transplantation as measured by active bile production, stabilization of prothrombin levels, and reduction in the circulating levels of lactic acid and the enzymes AST and ALT. Despite the removal of greater than 90% of the recipient's natural xenoantibodies prior to transplantation, the levels of antibody rapidly returned and were associated with antibody and complement-mediated rejection of the donor graft. Immunohistochemical evidence of graft rejection could be detected by the deposition of antibody, complement components including properdin, and endothelial swelling as early as 3 hr posttransplantation. These lesions progressed in severity and were accompanied by evidence of thrombosis and ischemic necrosis of the liver xenograft by 34 hrs posttransplantation. The main portal vein, hepatic artery, and vena cava were patent. The placement of the liver graft did not result in any improvement in the neurological status of the patient and she died 34 hr after xenografting due to irreversible brain damage. The information derived from this case has renewed interest in the clinical use of bioartificial devices and whole organ perfusion using xenogeneic tissue for temporary bridging of patients prior to allografting.

The inhibitor cytokine interleukin-1 receptor antagonist synergistically augments cyclosporine immunosuppression in a rat cardiac allograft model

Interleukin-1 receptor antagonist (IL-1ra) competes with IL-1 for binding of the IL-1 receptor, but does not elicit a cellular immune response. This study was designed to evaluate the effectiveness of IL-1ra in the immune and inflammatory responses to rat heart allografts. Experimental design was as follows: Group I HTx was syngeneic, BN to BN. The remaining groups were DA (RT 1a) to BN (RT 1n) allogeneic HTx. Group II was transplanted without immunosuppression. Group III received a low-dose IL-1ra regimen via osmotic pump into the peritoneum. Group IV recipients were similarly treated with a higher dose IL-1ra regimen. Group V rats received subtherapeutic cyclosporine (CsA) therapy while Group VI was treated with both CsA and low-dose IL-1ra. Group I rats survived indefinitely. Group II rats rejected their grafts at 5.33 +/- 1.37 days. Group III grafts survived for 7.16 +/- 0.48 days, and Group IV grafts for 8.16 +/- 0.75 days, both significantly longer than in Group II (P < 0.01). Group V animals treated with low-dose CsA had graft survival of 7.7 +/- 1.6 days, but combined therapy with CsA and IL-1ra in Group VI yielded significantly prolonged graft survival of 17.2 +/- 1.3 days (P < 0.0001). Histologic examination in treated recipients revealed delayed appearance of mononuclear cell infiltration. IL-1ra-treated recipients all demonstrated significantly reduced numbers of graft-infiltrating leukocytes; all phenotype subsets were equally affected. This study demonstrates the effectiveness of IL-1ra, in combination with low-dose CsA, in reducing the inflammatory response and rejection in the transplant setting.

Differential patterns of reaction of human natural antibodies to pig hepatocytes and vascular endothelium

We have recently conducted a series of experiments to characterize the pattern of reaction of human natural antibodies (NA) with individual pig liver cells. Pooled normal human serum (PHS) was incubated with cultured pig hepatocytes (HEP), aortic endothelial cells (AEC), and portal endothelial cells (PEC), and the reaction of NA to different cell types was measured by antibody-mediated cytotoxic (MTT assay), antibody binding (ELISA), and flow cytometric analysis. The human NA displayed a differential pattern of binding with hepatocytes exhibiting a more limited expression of xenoantigen expression than either aortic or portal endothelial cells. These differences in reaction patterns were also noted for Western blot analysis of individual cell membrane extracts. Preincubation of the pig cells with anti-pig MHC antibodies did not inhibit the binding of human IgM natural antibodies to the pig cells. Comparison of the pattern of NA absorption following the use of bioartificial liver support in patients with acute hepatic failure demonstrated limited ability of pig hepatocytes to absorb substantial amounts of NA. These studies indicate that pig hepatocytes are less vulnerable to NA cytotoxicity than pig vascular endothelial cells and that pig vascular endothelial cells express xenoantigens that are unique and not found on hepatocytes.

Regeneration-induced accelerated rejection in reduced-size liver grafts

Liver regenerative processes are associated with enhanced expression of alloantigens. Accordingly, we tested the hypothesis that such enhanced surface expression of alloantigens during regeneration of reduced-size liver grafts is associated with accelerated rejection. Our OLT model was LEW (RT1) to BN (RT1n), with donor liver resected by 50%. The study group consisted of reduced-size allografts. Control groups were syngeneic reduced-size isografts and full-size allografts. Reduced-size isograft recipients survived indefinitely. Both isografts and allografts regenerated to their prereduction size within 12 days. Recipients of reduced-size allografts died of accelerated rejection within 12.2 +/- 0.8 days, significantly earlier than recipients receiving full-size allografts (36.2 +/- 4.1 days, P < 0.01). The accelerated rejection in the regenerating allografts was mediated both by cellular and humoral mechanisms, evidenced by earlier lymphocytic invasion of the graft, enhanced donor MHC class II expression, and the emergence of IgM antibodies, directed specifically against donor endothelial antigens. These data suggest that regeneration of reduced-size allografts is accompanied by accelerated cellularly and humorally mediated alloreactivity. Recipients of reduced-size allografts may, therefore, benefit from more potent immunosuppression during the period of active liver regeneration.

The prevention of accelerated cardiac allograft rejection in sensitized recipients after treatment with brequinar sodium

Brequinar sodium (BQR) is a novel immunosuppressive agent that is highly effective in preventing B lymphocyte-mediated antibody production. We have examined the effects of BQR treatment in sensitized recipients on graft survival, donor-specific antibody responses (IgM and IgG), and the appearance of immunopathological lesions present in the grafts. LEW rat recipients were sensitized with single ACI skin graft on day 7 and received heterotopic ACI cardiac grafts on day 0. The recipients rejected the cardiac grafts in an accelerated fashion at day 2.5 post-transplantation, compared to day 7.0 in unsensitized recipients. The animals were treated with low (3 mg/kg/day) or high (12 mg/kg/3x weekly) doses of BQR during skin graft sensitization and/or after challenge with ACI heart allografts. All groups treated with BQR showed significant prolongation of graft survival in the sensitized recipients. The best survival was observed following high-dose BQR therapy during both sensitization and effector phases (median survival time = 40.0 days, P << 0.001). Daily treatment with BQR (3 mg/kg/day) prevented IgM (but not IgG) antibody responses. Treatment with higher doses of BQR (12 mg/kg/3x weekly) before and after skin graft sensitization was effective in preventing both IgM and IgG production. In general, BQR treatment resulted in effective suppression of anti-donor antibody responses, stable graft function, and a reduction in the severity of the acute vascular lesions in the graft. The effectiveness of BQR in preventing accelerated graft rejection when used at 12 mg/kg/3x weekly was comparable to that seen with treatment of sensitized animals with CsA at 15 mg/kg/day for 30 days. Daily treatment with cyclophosphamide at 5 or 15 mg/kg/day was ineffective for preventing graft rejection in sensitized recipients. These results indicated that BQR may provide an important addition to treatment protocols designed to prevent transplantation rejection in presensitized patients. BQR has the ability to significantly inhibit host cellular and humoral immune responses to the donor graft and this facet of the immunosuppressive activity of the drug may be responsible for preventing this aggressive form of rejection.

Pig aortic endothelial cell antigens recognized by human IgM natural antibodies

Human-to-pig xenoantibodies may constitute a major obstacle to the successful use of pigs as xenograft donors for human transplantation. Our studies demonstrate that normal human serum contains antibodies, primarily IgM, that are cytotoxic for pig aortic endothelial cells (PAECs). These antibodies bind to several antigens isolated from PAECs, lymphocytes, platelets, red blood cells, and the kidney. Absorption of human serum with pig lymphocytes removes the cytotoxic activity to PAECs and some, but not all, of the IgM antibodies capable of binding in an ELISA assay to the PAECs. The cytotoxic antibodies are inactivated by 2-mercaptoethanol, suggesting that they are primarily IgM. Whole cell extracts of PAEC, lymphocytes, platelets, red blood cells, and kidney were prepared and analyzed by Western blots to establish the cellular distribution of the xenoantigens that react with human IgM in pooled human serum. Results showed that several of the most intensely stained bands migrated between 24 and 66 kDa. High molecular weight bands (> 100 kDa) were observed only in kidney, platelet, and PAEC preparations. Human IgM xeniantibodies also reacted strongly in Western blots to endothelial cell membranes proteins with molecular weights of 62, 48, 42, 36, 34, 28, and 26 kDa. Absorption of human serum with pig lymphocytes removes IgM binding to all bands except for a 34-kDa Treatment of the PAEC membrane proteins with proteinase K disrupts the binding of the human IgM antibodies. Similar treatment with glycosidase F) resulted in a decrease in molecular weight of the 28- and 26-kDa bands, suggesting that these xenoantigens are glycoproteins and that antibody binding to some xenoantigens may not require glycosylation.

Removal of natural human xenoantibodies to pig vascular endothelium by perfusion of blood through pig kidneys and livers

We have examined the nature of the binding of human xenoantibodies to pig liver and kidney vascular endothelium. Our results demonstrate that human serum contains IgM and IgG xenoantibodies that bind to pig vascular endothelium, and that the pattern of antibody binding is similar for both livers and kidneys. Immunohistochemical analysis of pig kidneys after perfusion with human blood demonstrated the binding of both IgM and IgG xenoantibodies, complement (C3), and fibrinogen to the vascular and glomerular endothelium. An ELISA assay of the perfusate after perfusion of 500 ml of human blood through a single pig kidney for 60 min demonstrated a significant reduction in the amount of human IgM (67%) and IgG (55%) binding to pig aortic endothelium. Similar perfusion experiments conducted with pig livers were associated with minimal immunohistochemical evidence of the binding of human xenoantibodies to liver vascular endothelium. Immunofluorescence staining for IgM, IgA, C3, and C1q was negative or minimally positive in the liver vascular endothelium. Sinusoidal endothelium were weakly positive for IgG and fibrinogen. The perfusion of the pig liver with human blood was, however, associated with a significant reduction in the subsequent binding of IgM and IgG to pig kidney vascular endothelium. Pig liver perfusion was also responsible for the removal of both IgM and IgG xenoantibodies capable of reacting with pig aortic endothelium, as measured by an ELISA assay of the perfusate. These results suggest that both pig kidney and livers are capable of absorbing the xenoantibodies that may be responsible for mediating a hyperacute rejection of pig xenografts and that the distribution of the target antigens for these antibodies is similar in the two organs.

Liver adenosquamous carcinoma invading the esophagogastric junction - a case-report and a review of the literature

A case of adenosquamous carcinoma of the liver involving the esophago-gastric junction is reported. The preoperative diagnosis of a submucosal tumor of the cardia of the stomach was made following a barium meal study, gastrofiberscopy, ultrasonography, and computed tomography. At surgery, a tumor was found measuring 6x5 cm in diameter and involving the left lobe of the liver, lower esophagus and cardia of the stomach, and the origin of the tumor was unclear. Post-operative histopathology revealed that the tumor contained two different malignant components of glandular and squamous cells. An adenosquamous carcinoma originating in the liver was suspected, since the cancer cells did not involve the esophago-gastric mucosa and were mainly located in the S2 of the liver. Despite aggressive adjuvant chemotherapy, the patient died of a recurrence in the liver seven months later. This seems to be the first documentation of adenosquamous carcinoma of the liver invading the esophago-gastric junction.

The prolongation of concordant hamster-to-rat cardiac xenografts by brequinar sodium

Brequinar sodium (BQR) prevents cell proliferation by virtue of its inhibition of de novo pyrimidine biosynthesis. The immunosuppressive activity of BQR is highly effective in prolonging heart, liver, and kidney allograft survival in the rat. In these experiments, we have tested the ability of BQR to prevent the rejection of concordant cardiac xenografts. LEW inbred rats transplanted with heterotopic hamster hearts were treated orally with brequinar sodium as a single agent. The survival of the cardiac xenografts was significantly prolonged with a variety of treatment regimens. The most effective treatment was the daily oral administration of BQR at 3 mg/kg. At this level, the median graft survival was approximately 25 days. Four animals had hamster heart xenografts that functioned for more than 90 days. The prolonged survival of the xenografts was associated with relatively constant plasma drug levels of approximately 1 to 3 micrograms/ml and a marked suppression of IgM production. At rejection, there was a significant rise in IgM levels compared with those of recipients with stable xenografts. In vitro MLR responses were effectively inhibited by BQR, with an IC50 of 0.08 microgram/ml. The results of these experiments demonstrate that BQR is a new immunosuppressive agent that is highly effective as a single agent in prolonging the survival of hamster-to-rat cardiac xenografts. The prolonged xenograft survival is associated with effective suppression of rat antihamster antibody production, suggesting that brequinar sodium may be an important addition to multidrug immunosuppressive regimes designed to prevent B and T lymphocyte-mediated immune responses.

Endothelial Function in Thrombosis and Thrombolysis

The localization of tissue factor (TF) in atherosclerotic plaques of human aortas was immunohistochemically examined using rabbit anti-IgG against recombinant TF, which was expressed in E. coli. TF, the initiator of the extrinsic coagulation pathway, was ubiquitously present in atherosclerotic intima, and was expressed mainly by macrophages, but not by endothelial cells. It has been suggested that some macrophages in atherosclerotic intima co-express both molecules of TF and platelet-derived growth factor-B chain. We have developed a morphometrically quantitative in vitro assay for angiogenesis, using endothelial cultures on collagen gel incorporating plasminogen. With this method, we have obtained findings suggesting that plasminogen and plasminogen activators (PAs), especially urokinase-type PA (uPA) derived from endothelial cells, enhance angiogenic activity, probably by increasing endothelial migration. uPA was immunohistochemically observed to be primarily cell-associated on the focal contract areas, probably via its receptors on endothelial cells. These findings may support the hypothesis that the activation and regulation of the pericellular fibrinolysis system is closely related to angiogenesis.

Extracellular and cell-associated localizations of plasminogen activators and plasminogen activator inhibitor-1 in cultured endothelium

The extracellular localizations of urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) were examined in cultured bovine capillary endothelial cells (BCEs) by an immunofluorescence method using BCEs treated with or without saponin and focal contact preparations. The specific immunofluorescence of cell surface uPA showed a patchy or strand-like distribution and was colocalized with vinculin strands indicating that uPA secreted from BCEs was mainly deposited at the cell surface of focal contacts. BCEs at a subconfluent density showed a higher intensity of specific immunofluorescence for uPA than when they were at a confluent density. tPA was observed over the dorsal surface of cultured BCEs and accentuated at their margins, suggesting that tPA was diffusely distributed on the luminal surface of BCEs in vivo. PAI-1 was distributed in the extracellular matrix under cultured BCEs. These findings suggest that uPA and PAI-1 are located under BCEs participating in the regulation of proteolytic activities provoked by plasminogen-PAs-plasmin system in vivo. The localization of tPA appears to be consistent with its function, which is to maintain the fluidity of the blood and to initiate thrombolysis in vivo.

Successful surgical treatment of hepatocellular carcinoma invading into biliary tree

A 41-year-old woman was admitted to hospital with obstructive jaundice. Computed tomography showed a large mass in the right hepatic lobe and marked dilatation of the biliary tree in the left lateral segment of the liver. Angiography showed evidence of neovascularity. Percutaneous transhepatic cholangiography revealed complete obstruction of the common bile duct just below the bifurcation. The serum level of alpha-fetoprotein on admission was 1,080,000 ng/ml. These findings suggested to us a primary hepatocellular carcinoma invading the intrahepatic bile duct. Extended right lobectomy and hepaticojejunostomy for bile drainage was carried out. The patient is doing well 3 years after surgery. Hepatocellular carcinoma (HCC) invading to the portal vein is not so rare, but invasion into the bile duct is much less common. In 1947, Mallory described a single case of HCC invading the gallbladder and obstructing extrahepatic bile ducts. In 1975, Lin termed this HCC "Icteric type hepatoma". The incidence of such HCC in Japan was reported to be 1.9-9%. Obstructive jaundice is a clinical manifestation of the terminal stage in HCC. We describe here our treatment of a woman with HCC invading the common bile duct. Right extended lobectomy and reconstruction of hepaticojejunostomy were effective.

[Hypoxemia of liver cirrhosis--an autopsy case study]

41 year-old male with liver cirrhosis accompanying severe hypoxemia was presented. Shortly after the diagnosis of liver cirrhosis, he suffered from exertional dyspnea and cyanosis. Though home oxygen therapy had been prescribed for 2 years, hypoxemia gradually progressed accompanied by persistent cough, mucous sputa and intermittent fever. The chest X-ray revealed bilateral interstitial shadow particularly localized in lower lung fields. The arteriovenous shunt ratio was shown to be 24% by oxygen method. Perfusion lung scan using 99mTc-labeled MAA revealed perfusion defects in bilateral lung fields and radionuclide uptake was strongly demonstrated in the kidneys. These clinical data suggested that severe hypoxemia was probably due to multiple arteriovenous shunt. With further progression of hypoxemia for 4 months, he died of hepatic failure and pulmonary infection. Autopsy showed Miyake's type B cirrhosis. Multiple pleural and subpleural arteriolar nevi were demonstrated grossly and microscopically. There were no arteriovenous malformations demonstrated after injection of barium-gelatin solution into the pulmonary artery. Histologically, irregularly dilated vessels were found in the lung parenchyma beneath the pleura and filled with blood and injection material. These clinical and pathological findings provided evidence that the mechanism of arterial desaturation was pulmonary arteriovenous shunting due to liver cirrhosis.

Sustained arterial injury and progression of atherosclerosis

In this paper the following findings were described: 1) Murine arteriosclerosis induced by immune challenge was ultrastructurally characterized by intimal monocyte-macrophage recruitment and minor endothelial alterations; 2) Atherosclerotic lesions of human coronary arteries exhibited frequently segmental or patchy neovascularization, probably representing a response to intimal injury as an example of repair process. Newly formed blood vessels in the intima were derived from both adventitial and luminal endothelial growth; 3) Angiogenesis in vitro was related to the activation of fibrinolytic system especially via the autocrine production of u-PA from endothelial cells, and this process was modulated by cytokines and TGF beta. These findings add more evidence for the hypothesis that the chronic inflammation-repair process plays an essential role in the initiation and progression of atherosclerosis.

Surgical manipulation of VX2 carcinoma in the rabbit liver evokes enhancement of metastasis

To search for possible untoward effects of surgical manipulation of a malignant tumor, a series of experiments was carried out using VX2 carcinoma of rabbits. Fourteen days after inoculation of VX2 carcinoma into the liver, the rabbits were separated into two groups: Group I, manual manipulation during relaparotomy; and Group II, relaparotomy alone without manual manipulation of the tumor. After these procedures, the tumor was surgically removed and histologic examinations were made. The incidence of vascular permeation of liver tumor cells into the hepatic vein was significantly higher in Group I (P less than 0.01). On the 14th day after resection of the tumor, the number of metastatic nodules in the lungs was significantly increased in Group I (P less than 0.01). Survival time of rabbits after resection of tumor was significantly shorter in Group I (P less than 0.01). These results are taken to mean that manual manipulation of a tumor may well enhance metastasis.

A role of fibrinolytic activity in angiogenesis. Quantitative assay using in vitro method

The functional role of the fibrinolytic system in capillary growth was investigated using bovine capillary endothelial cells (BCEs) cultured on a Type I collagen gel matrix, into which the cells migrated to form capillary-like tubular structures. The length of the tubes formed were measured morphometrically using an image analyzer in the absence and presence of fibrinolytic proteases, namely plasminogen, plasminogen activators (PAs) and PA inhibitor (PAI). The addition of plasminogen (25 micrograms/ml) to the gel matrix significantly increased the length of BCE tubes found on the 9th day of culture (p less than 0.01), with a dose-dependent tendency. The simultaneous addition of a basic fibroblast growth factor (bFGF, 10 ng/ml) enhanced this tube formation as early as the 3rd day of culture (p less than 0.01). Cultured BCEs secreted both tissue-type and urokinase-type PAs (tPA and uPA) and PAI-1 into the culture medium, and the secretion of both PAs was enhanced by the addition of bFGF. However, the secreted tPA was composed mostly of an inactive form of tPA.PAI-1 complex, and the PA activity was derived mostly from uPA. Inhibitors of plasmin suppressed the enhancing effect of plasminogen on angiogenesis. In addition, anti-uPA IgG markedly inhibited the enhancing effect of plasminogen on the 4th and 7th days of culture (p less than 0.01), whereas anti-tPA IgG showed an inhibitory tendency only on the 4th day of culture (p less than 0.05). These findings indicate that the plasminogen-PAs system, especially uPA synthesized and secreted by BCEs, plays an important role in regulating angiogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)