Decreased in vivo metabolism of drugs in chronic renal failure

Chronic renal failure (CRF) is associated with a decrease in renal excretion of drugs, but its effects on the liver metabolism of xenobiotics are poorly defined. The objectives of this study were to determine the effects of CRF on hepatic cytochrome P450 (CYP450) and its repercussions on in vivo hepatic metabolism of drugs. Two groups of rats were studied: control paired-fed and CRF. CRF was induced by subtotal nephrectomy. Total CYP450 activity and protein expression of several CYP450 isoforms (CYP1A2, CYP2C11, CYP3A1, CYP3A2) were assessed in liver microsomes. In vivo cytochrome P450 activity was evaluated with breath tests using substrates for different isoenzymes: caffeine (CYP1A2), aminopyrine (CYP2C11), and erythromycin (CYP3A2). Creatinine clearance was reduced by 60% (P <. 01) in rats with CRF. Compared with control paired-fed rats, total CYP450 activity was reduced by 40% in rats with CRF. Protein expression of CYP2C11, CYP3A1, and CYP3A2 was considerably reduced (more than 45%, P <.001) in rats with CRF, whereas the levels of CYP1A2 were unchanged. In rats with CRF, there was a 35% reduction in the aminopyrine (CYP2C11) and the erythromycin (CYP3A2) breath tests compared with control animals (P <.001). The caffeine (CYP1A2) breath tests remained comparable to controls. Creatinine clearance correlated with the aminopyrine and erythromycin breath tests (r(2) = 0.73 and r(2) = 0.81, respectively, P <.001). In conclusion, CRF is associated with a decrease in total liver CYP450 activity in rats (mainly in CYP2C11, CYP3A1, and CYP3A2), which leads to a significant decrease in the metabolism of drugs.

Effect of calcium antagonists on rat liver during extended cold preservation-reperfusion

BACKGROUND

Nisoldipine, a calcium antagonist, has been reported to improve the quality of grafted rat livers. We thus assessed the protective effect of two calcium antagonists, nisoldipine and nickel, during extended cold ischemia-reperfusion.

METHODS

Rat livers were isolated and perfused before or after 24 hr of cold ischemia in University of Wisconsin solution (4 degrees C) with or without nisoldipine or nickel. Sinusoidal endothelial cell and hepatocyte functions were measured by hyaluronic acid and taurocholate elimination, respectively.

RESULTS

Similar alterations in hepatocyte and sinusoidal cell functions were found in all groups after cold ischemia with or without calcium antagonists. In a second set of experiments, liver transplantation was performed in two groups of rats with livers stored under identical conditions with or without nisoldipine. Seven of 12 animals (62.5%) in both groups survived for over 10 days after 24-hr preservation in University of Wisconsin solution. Survival rates were similar in both groups.

CONCLUSIONS

Calcium antagonists do not appear to have a direct protective effect on sinusoidal endothelial cell and hepatocyte functions, nor on the overall liver preservation after extended cold preservation-reperfusion.

Hepatic sinusoidal fibrosis induced by cholesterol and stilbestrol in the rabbit: 2. Hemodynamic and drug disposition studies

We assessed hepatic functions and systemic and splanchnic hemodynamics in a new model of hepatic sinusoidal fibrosis. Fibrosis was induced by the simultaneous administration for 8 weeks of diethyl-stilbestrol (DES) (10 mg twice weekly, subcutaneously) and cholesterol-supplemented diet (1%) in rabbits. A marked and progressive impairment of hepatic function was observed during the 8 weeks of treatment with a significant decrease in indocyanine green (ICG) systemic clearance (-89%; P < .001) and aminopyrine elimination (-69%; P < .001). In fibrotic animals, hyperdynamic circulation was found with an increased cardiac output (+73%, P < 0.01) and a decreased peripheral vascular resistance (-50%; P < .005), as evaluated by the microsphere technique in animals that were awake. The total portal venous inflow was not significantly modified in fibrotic rabbits. However, since there was a marked increase in the liver weight, the portal venous inflow was significantly decreased when expressed per gram of liver weight (-30%; P < .05). In contrast, the hepatic artery blood flow was markedly increased, even when expressed per gram of liver weight (+95%; P < .01). Portal pressure was significantly increased in treated rabbits (from 7.4 +/- .4 to 14.4 +/- .6 mm Hg, P < .01). This new experimental model could prove useful to evaluate the influence of extensive perisinusoidal fibrosis on exchanges between plasma and hepatocytes, particularly of protein-bound substances.

Neuronal expression of human immunodeficiency virus type 1 env proteins in transgenic mice: distribution in the central nervous system and pathological alterations

It is now well documented that human immunodeficiency virus type 1 (HIV-1) induces encephalopathy in patients with AIDS. In vitro studies have implicated the envelope protein (gp120) as a factor which causes neuronal death. To better evaluate the role and elucidate the mechanisms of gp120 neurotoxicity, we have developed transgenic mice carrying a segment of the HIV-1 genome that expresses the viral gp160 protein under the control of the human neurofilament light gene promoter. In two separate lines of transgenic mice, the Env protein was found to be expressed in several nuclei of the brain stem and in the anterior horns of the spinal cord. The two lines showed identical patterns of Env expression. Neuropathological evaluation revealed numerous abnormal dendritic swellings in the immunostained motor neuron structures. Large and numerous neuritic swellings were also prominent in the nucleus gracilis and in the gracilis and cuneate fascicles. In addition, reactive astrocytosis was observed in several immunoreactive areas of the central nervous system. These transgenic mice offer a unique model to further investigate the role of HIV-1 Env protein in neuronal toxicity and to help elucidate the mechanisms that are involved.

Cold ischemia-reperfusion injury of the liver. Role of the liver donor nutritional status in rats

To verify the role of donor nutritional status on the quality of liver preservation after cold storage, we assessed hepatocyte and liver endothelial cell viabilities and functions in an isolated perfused rat liver model. Livers from fed and fasted Wistar rats were isolated and perfused either immediately after liver harvesting or after a 24-hr cold (4 degrees C) preservation in University of Wisconsin solution. Hyaluronic acid (150 ng/ml) and taurocholate (11.5 micrograms/ml) were infused into the reservoir, and their eliminations were assessed to evaluate liver endothelial cell function and hepatocyte function, respectively. Liver viability was estimated by intrahepatic resistance, oxygen consumption, bile secretion, and lactate dehydrogenase release. In addition, cell viabilities were evaluated by trypan blue staining. In fed-rat livers, glycogen content did not differ before or after the cold preservation, although a reduction was observed during the subsequent perfusion period. Liver glycogen content in fed rats was markedly higher than in the fasted rats at each time point studied. In fasted and fed rats, liver viability parameters and hepatocyte function were moderately altered, whereas liver endothelial cell function was markedly impaired after cold preservation. However, feeding had no influence on either hepatocyte or liver endothelial cell functions which were similarly altered in both nutritional conditions. The present data show that the nutritional status of liver donors does not play an important role in the preservation of liver endothelial cells after cold ischemia-reperfusion and, thus, should not affect the overall resistance of livers to hypothermic-ischemic injury.

Liver function improvement following increased portal blood flow in cirrhotic rats

BACKGROUND/AIMS

Liver microcirculation in cirrhosis is characterized by development of intrahepatic shunts and capillarization of sinusoids secondary to cell necrosis and deposition of new collagen, resulting in both decreased drug elimination and increased vascular resistance with portal hypertension. The aim of this study was to examine the effects of increased portal blood flow on hepatic microcirculation and drug elimination in 13 perfused livers from cirrhotic rats.

METHODS

Intrahepatic resistance was assessed under basal conditions (21.2 +/- 0.3 mL/min) and 1 hour after doubling the flow (41.6 +/- 1.0 mL/min). A multiple indicator dilution technique was used at both flow rates to measure sinusoidal volume, albumin and sucrose extravascular volumes, and cellular water volume. Hepatic elimination of labeled taurocholate and propranolol was also measured, and the recovery of 15-microns microspheres was used to evaluate large intrahepatic shunts.

RESULTS

After doubling the flow, intrahepatic resistance decreased by 31%. Sinusoidal and extravascular volume increased significantly without a change in microsphere recovery. However, there was a marked increase in taurocholate and propranolol elimination by cirrhotic livers. Moreover, during high flow, significant correlations were found between changes in albumin extravascular volume and taurocholate and propranolol elimination.

CONCLUSIONS

Increased portal blood flow in cirrhotic rats induces a decrease in intrahepatic resistance without changes in intrahepatic shunting and improves drug elimination by the liver without deleterious effects on hepatocyte viability.

Systemic and splanchnic haemodynamic effects of pentifylline in rats with portal hypertension

1. The systemic and splanchnic haemodynamic effects of pentifylline (40 mg/kg body weight intravenously) were assessed in rats with portal hypertension associated either with CCl4-induced cirrhosis (n = 13) or portal vein ligation (n = 13). 2. Heparinized catheters were placed into the portal vein, inferior vena cava, aorta and left ventricle with exits from the neck. Haemodynamic studies were performed 4 h after consciousness was regained. Cardiac output and regional blood flows were measured using radiolabelled microspheres and the reference sample method in seven rats in each group; portal-systemic shunting was measured using microsphere injection in the ileo-colic vein in six rats in each group. 3. Forty-five minutes after injection, pentifylline had no effect on mean arterial pressure, cardiac output, peripheral resistance, portal venous flow, hepatic artery flow or portal-systemic shunting in either group of rats with portal hypertension. The drug lowered portal pressure (-18%) in cirrhotic rats, but not in portal-vein-ligated rats. 4. These data demonstrate that pentifylline lowers portal pressure in cirrhotic rats without affecting portal venous flow and portal-systemic shunting; this effect is possibly mediated by changes in intrahepatic resistance related to the effects of pentifylline on blood viscosity and/or on intrahepatic vasomotor tone.

The effect of alcohol-induced hepatomegaly on portal hypertension in cirrhotic rats

Male Sprague-Dawley rats with CCl4-induced cirrhosis (confirmed by increased collagen content and light microscopy) were fed either ethanol (Group A, n = 9) or isocaloric carbohydrate diet (Group B, n = 8) for 4 weeks. Histologic and hemodynamic measurements were obtained in the awake state before (time 1) and after the 4 weeks of diet (time 2). Portal-systemic shunts were evaluated using radiolabelled microspheres. Liver weight was increased in Group A (16.5 +/- 0.5 vs. 14.2 +/- 0.5 g, mean +/- SE, p less than 0.005) as was the ratio of liver weight over total body weight (3.41 +/- 0.05 vs. 2.86 +/- 0.09%, p less than 0.0001, +19.2%). Hepatocytes surface area was increased in the ethanol group (357 +/- 9 vs. 294 +/- 7 microns 2, p less than 0.0001). In Group B, only 9 +/- 2% of hepatocytes had steatosis as opposed to 69 +/- 3% of centronodular and 34 +/- 3% of perinodular hepatocytes in Group A (p less than 0.001). Portal pressure remained stable in both groups (time 1 (A) 16.9 +/- 0.8, (B) 15.8 +/- 1.1 mmHg, n.s.; time 2 (A) 15.9 +/- 0.7, (B) 15.8 +/- 0.6 mmHg, n.s.). Portal-systemic shunts did not change with time or diet (time 1 (A) 10.6 +/- 3.7%, (B) 4.1 +/- 2.1%, n.s.; time 2 (A) 13.4 +/- 5.9%, (B) 10.8 +/- 4.3%, n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Combined treatment of portal hypertension with ritanserin and propranolol in conscious and unrestrained cirrhotic rats

We recently reported that ritanserin, a 5-hydroxytryptamine receptor antagonist, induced significant reduction of portal pressure in cirrhotic rats. In this study, we investigated the hemodynamic effects of a combination of propranolol and ritanserin in conscious and unrestrained cirrhotic rats. Heparinized catheters exiting from the neck were placed into the portal vein, inferior vena cava, aorta and left ventricle. Cardiac output and regional blood flows were measured with radiolabeled microspheres and the reference-sample method. Serial hemodynamic studies were performed 4 hr after rats awakened (basal), 1 hr after administration of ritanserin (0.63 mg/kg body wt, intravenously) and after intravenous propranolol infusion (0.33 mg/kg/min for 15 min) in nine cirrhotic rats. Similar measurements were obtained in a control group of eight cirrhotic rats treated with the solvents of ritanserin and propranolol. Ritanserin caused significant reduction of portal pressure (-19%). Portal-venous inflow and splanchnic arteriolar resistances remained unchanged, whereas portal-venous resistances were slightly but significantly lowered (-17%); and ritanserin had no effects on systemic hemodynamics. The addition of propranolol resulted in further reduction of portal pressure (-24%); the final reduction after combined therapy was -38%. Propranolol induced a marked decrease in cardiac output (-31%) and portal-venous inflow (-30%). It also caused a significant increase in splanchnic arteriolar resistance (+39%), but did not magnify the ritanserin-induced decrease of portal-venous resistance. The combined therapy did not modify the mean arterial pressure. Our results show that the effects of ritanserin on portal pressure--probably mediated by a reduction of intrahepatic and/or portocollateral resistances--can be potentiated by propranolol, which lowers the portal-venous inflow.

Evaluation of infection with human immunodeficiency virus type 1 by using nonisotopic solution hybridization for detection of polymerase chain reaction-amplified proviral DNA

A convenient assay combining solution hybridization and enzyme immunoassay for DNA-RNA hybrids (polymerase chain reaction-enzyme immunoassay [PCR-EIA]) was developed to detect human immunodeficiency virus type 1 (HIV-1) provirus amplified by the PCR and was compared with oligomer hybridization with 32P-labeled SK19. In PCR-EIA, a fragment of the HIV-1 gag gene from peripheral blood mononuclear cells was first amplified with primer pair SK38/SK39 or O1/O2. PCR-amplified material was reacted in solution with a biotinylated RNA probe. Biotinylated hybrids were measured in a microtiter-plate EIA with antibiotin antibody and a beta-D-galactosidase-conjugated monoclonal antibody to DNA-RNA hybrids. Ten copies of HIV-1 DNA could be detected by PCR-EIA by using two different sets of primers. HIV-1 DNA was detected in 104 of 108 peripheral blood mononuclear cell samples by using SK38/39 and oligomer hybridization, in 104 of 108 samples by using SK38/SK39 and PCR-EIA, and in 104 of 108 samples by using O1/O2 and PCR-EIA. HIV-1 provirus was detected in 107 of 108 samples by using a combination of two sets of primers. One sample from a seropositive patient was negative in all three PCR assays, and six samples gave discordant results between primer pairs. Six of the latter samples scored negative in a PCR for beta-globin but became positive when the sample was diluted before amplification. When applied to clinical samples, PCR-EIA generated results similar to those of an isotopic assay for detection of amplified DNA.

Ritanserin decreases portal pressure in conscious and unrestrained cirrhotic rats

We have recently demonstrated that ritanserin, a serotonin 5-hydroxytryptamine receptor antagonist void of systemic effects, caused a significant reduction of portal pressure in conscious cirrhotic dogs. The mechanism by which ritanserin lowers portal pressure is poorly defined. We investigated the splanchnic and systemic hemodynamic effects of ritanserin (0.63 mg/kg body wt i.v., a dose known to completely inhibit binding of 5-hydroxytryptamine to its receptors), in conscious and unrestrained cirrhotic rats (n = 13). Heparinized catheters were placed into the portal vein, inferior vena cava, aorta, and left ventricle with exit from the neck. Hemodynamic studies were performed 4 h after consciousness was regained. Cardiac output and regional blood flows were measured using radiolabeled microspheres and the reference sample method. Sixty minutes after administration, ritanserin caused a significant reduction of portal pressure (-17%) with minimal changes in portal venous inflow (+3%). Portal vascular resistance decreased significantly (-23%), whereas splanchnic arteriolar resistance was similar before and after ritanserin. A significant increase in mean arterial pressure (+5%) and cardiac output (+22%) was observed. Our results suggest that ritanserin lowers portal pressure through a mechanism separate from portal venous inflow. This effect could be due to changes in intrahepatic or on portocollateral resistances, or both. These findings support the potential use of this new agent in the treatment of portal hypertension.

The photolysis of ethylene at 193 nm

The photolysis of ethylene has been studied at pressures from 50 to 3000 Torr using a pulsed ArF excimer laser at 193.3 nm. Major products were acetylene, n-butane, 1-butene, ethane, and 1,3-butadiene, with smaller amounts of propane, propene, methane, and allene. Quantum yields varied with pressure and reaction time; the latter dependence is ascribed to secondary photolysis of butene and butadiene. The reaction products are accounted for by three primary processes:[Formula: see text]followed by reactions of H, [Formula: see text] and C2H5 radicals. The vibrationally excited C2H3radical can decompose to H + C2H2 or can be stabilized by collision. The pressure dependence of the quantum yields of the primary processes [1]–[3] is complex, and a photodissociation mechanism involving several intermediates and excited states of ethylene is presented to account for the present results and previous measurements at 185 nm. Keywords: ethylene, uv photolysis.

Efficacy of incorporating cyclosporine into liposomes to reduce its nephrotoxicity

A preparation of cyclosporine (CsA) in liposomes was tested in the rat to evaluate its effectiveness in reducing CsA nephrotoxicity. The drug was injected intravenously in unilaterally nephrectomized Lewis rats at a daily dose of 25 mg/kg for 14 days, either in a cremophore solution (eight rats) or in a preparation of liposomes (eight rats). Another group of four animals received the cremophore solution alone. Overall, rats treated with the CsA-liposome preparation had reduced toxicity, exhibiting better survival rates and less weight loss than those treated with the CsA-cremophore. Incorporating CsA into liposomes induced a statistically significant (p less than 0.05) reduction in the otherwise progressive increase of serum creatinine during week 2 of the experiment. Following administration of CsA-liposome preparation, epithelial cells of the proximal renal tubules appeared morphologically normal, without evidence of vacuolization, which is characteristic of CsA nephrotoxicity and was seen in the CsA-cremophore group. Although the exact mechanism is not clearly understood, it is likely that the tissue distribution of CsA, when incorporated into liposomes, is modified in favour of the reticuloendothelial cells, thereby sparing highly sensitive, but non-target organs such as the kidneys.

Maternal and neonatal outcome in pregnancies with no risk factors

Between November 1979 and April 1984, 790 consecutive pregnant women who considered themselves as having a "normal" pregnancy were followed in private practice from 9 weeks' gestation until 6 weeks post partum. The women had no pre-existing disease or problem classified as a risk to the pregnancy at the time of their first visit, had a singleton pregnancy and gave birth at Notre-Dame Hospital, Montreal. Maternal complications occurred during the course of pregnancy in 181 women (23%). Complications were mostly related to obstetric conditions (10%), such as preterm labour, intrauterine growth retardation (IUGR) and antepartum hemorrhage, or to medical conditions (12%), the most prevalent of which was hypertension (77% of medical conditions). Neonatal complications occurred in 183 infants (23%). The corrected perinatal death rate was 2.5 per 1000. Prematurity, IUGR and dysmaturity/postmaturity accounted for nearly half of the complications. Hyperbilirubinemia occurred in 7% of the cases. Among women without any maternal complications during pregnancy, the frequency rate of neonatal complications was 19%, compared with 23% among the entire group of 790 women. Our results suggest that the absence of maternal complications does not protect the infant from a neonatal complication. Further refinement is needed to identify markers of obstetric, medical and neonatal complications in pregnancies with no risk factors.

Hemolytic uremic syndrome in renal allografted patients treated with cyclosporin

The classical triad of hemolytic uremic syndrome (microangiopathic hemolytic anemia, severe thrombopenia, and renal failure) developed de novo in three of our renal transplanted patients under cyclosporin A treatment. The predominant morphologic findings in the grafts consisted of glomerular and arteriolar thrombosis as well as arteriolonecrosis, all features of the syndrome. In one instance, ischemic bowel disease supervened after graft removal and was associated with persistent low grade microangiopathic process. De novo hemolytic uremic syndrome has been reported in patients treated with cyclosporin A following bone marrow or liver transplantation as well as in a few renal graft recipients. This peculiar form of cyclosporin A nephrotoxicity should not be confused with acute rejection of the renal transplant.

Blood transfusions and survival after colectomy for colorectal cancer

This study was carried out to determine the effect of perioperative blood transfusions on the survival of patients operated on for colorectal cancers. Cox's regression analysis was applied to 281 patients operated for cure of Dukes' stage A, B or C disease. Other variables studied were age, sex, tumour location, and preoperative hemoglobin, lymphocyte and albumin values. Perioperative deaths, pre- and postoperative immunodepression, neoplasia in situ, nonresections and stage D disease were excluded. It was found that the number of units of blood transfused had a strong influence on the prognosis of patients with colorectal cancer, particularly colonic cancers, but the effect could not be demonstrated when rectal cancers were studied separately, perhaps because of the small number of cases. The mechanism of action of blood transfusions seems to be independent of the other analysed variables. The authors suggest that perioperative blood transfusions may have an immunomodulatory effect in patients with colonic cancer, as already shown in recipients of transfused kidney allografts.

[Complications of the treatment of cervix neoplasms by radiotherapy]

Of 939 patients treated by radiotherapy for carcinoma of the cervix at the hôpital Notre-Dame in Montreal, between 1979 and 1981, 275 (29.3%) had digestive, urologic, gynecologic, vascular, osseous and cutaneous complications. Surgery was necessary to treat 73 complications in 55 patients (5.9%): 42 digestive (25 occlusions, 13 fistulas and 4 perforations); 22 urologic (16 occlusions, 5 fistulas, 1 hemorrhage); 6 gynecologic (3 hemorrhage and 3 uterine necrosis); 1 cutaneous, 1 vascular and 1 osseous necrosis. No direct correlation was found between the incidence of the complications and certain predisposing factors such as the type of radiotherapy, patients' age, stage of the disease and gynecologic surgery before radiotherapy. However, there was a strong correlation between the incidence of complications and the dose of radiotherapy and the need for gynecologic surgery after radiotherapy. High morbidity was observed in the 55 patients treated surgically: they had to undergo a mean of 2.36 operations each, 2.98 general anesthetics, 1.81 hospitalizations (mean duration 75.7 days); 21 had one or more definitive stomas. The death rate was 5.45%. Surgical treatment was individualized. Limited resections were performed for occlusions, fistulas and perforations whenever it was technically feasible to treat digestive and urologic complications. A bypass procedure was used when resection would have been too extensive or dangerous. The majority of rectal lesions were treated by colostomy and a Hartmann procedure.

Mitomycin-C nephrotoxicity: a clinico-pathologic study of 17 cases

The potential nephrotoxicity of Mitomycin-C (MMC) was studied in 17 autopsies from patients treated with this drug, usually in association with other anti-neoplastic agents. Renal functional deterioration was present in seven cases while urinalysis showed an overt proteinuria and hematuria in six and four instances, respectively. Four of these patients also developed a severe microangiopathic hemolytic anemia (MAHA) and thrombopenia. Histological examination did not reveal residual tumor in three of them. However renal lesions similar to those observed in the hemolytic-uremic syndrome (HUS) were associated with glomerular mesangiolytic changes and nuclear atypias in glomerular and tubular cells. Immunofluorescence and ultrastructural studies confirmed these findings. In other patients, variable degrees of cellular atypias and of mesangiolysis were observed. The severity of the glomerular, vascular, and tubular lesions correlated with the total dosage of MMC received. The nephrotoxic potential of MMC seems to be delayed in onset and dose related.

A prospective study of blood pressure in pregnancy: prediction of preeclampsia

A prospective study of blood pressure recording was conducted in 1000 patients, at each antenatal visit, with the use of an automatic random-zero sphygmomanometer. In 46 patients, among 808 primigravid women, who developed preeclampsia, the diastolic and mean blood pressures were significantly elevated compared to values at the first antenatal visit (p less than 0.01, 9 to 12 weeks). This difference was sustained throughout pregnancy until delivery by at least 10 mm Hg as compared to pressures in the normotensive group. Sensitivity for predicting preeclampsia early in pregnancy with an elevated blood pressure measurement (130 to 135/80 to 85 mm Hg) ranged from 16% to 57% while specificity ranged from 75% to 98%. The results substantiate an early vasospasm (9 to 12 weeks) in those women destined to develop preeclampsia.

Adriamycin and adriamycin-DNA nephrotoxicity in rats

The early nephrotoxicity of free and DNA-bound adriamycin (ADR) was compared in left nephrectomized rats. Free ADR induced progressive renal failure within 3 weeks, in association with renal changes characterized by severe tubular distention and vacuolization of podocytes in glomeruli. On the contrary, renal function remained normal and renal lesions were discrete in animals treated with ADR bound to DNA. Thus, the binding of ADR to DNA seems to reduce the early nephrotoxicity of free ADR.

Microangiopathic hemolytic anemia, renal failure, and noncardiogenic pulmonary edema: a chemotherapy-induced syndrome

Following gastrectomy for locally advanced adenocarcinomas, three patients developed microangiopathic hemolytic anemia and renal failure shortly after completing courses of adjuvant chemotherapy with mitomycin and 5-FU. These complications progressed despite cessation of chemotherapy, and all three patients died of noncardiogenic pulmonary edema precipitated in two cases by blood transfusions. At autopsy, two patients had no residual carcinoma and all had a diffuse microangiopathy involving mainly the kidneys and lungs. There was intimal hyperplasia of many arterioles sometimes associated with complete occlusion of the lumen, prominent nuclear atypia in many capillary cells, and numerous capillary fibrin thrombi. Direct immunofluorescence studies revealed extensive fibrinogen-fibrin deposits in the vascular lesions. Chemotherapy-induced microangiopathic hemolytic anemia and renal failure may predispose patients to fatal episodes of noncardiogenic pulmonary edema that can be triggered by blood transfusions.

Beneficial effects of methylprednisolone on urinary excretion of lysosomal enzymes in acute renal ischemia

An experimental model of canine normothermic renal ischemia was used to determine whether lysosomal urinary enzyme excretion reflects the extent of ischemic cellular injury, as assessed by subsequent renal function (serum creatinine level) and morphologic changes. The value of a lysosomal membrane-stabilizing agent (methylprednisolone) in protecting kidneys from ischemic damage by preventing lysosomal enzyme release was assessed. Results showed conclusively that urinary enzyme activities of beta-galactosidase and N-acetyl-beta-glucosaminidase are valuable indicators of renal cellular damage and functional outcome after ischemic injury, and that methylprednisolone at a dose of 30 mg/kg, given intravenously 1 hour before a 1-hour period of normothermic ischemia, protects the kidney both biologically and morphologically, by reducing the excretion of lysosomal enzymes after revascularization.

Comparative toxicity of adriamycin and adriamycin-DNA in rats

Adriamycin (ADR) can be linked to DNA without loss of its antitumoral activity while reducing the acute toxicity of free ADR (Deprez--DeCampeneere et al., 1979, 1980). However, the potential chronic toxic effects of both forms of ADR are poorly documented. For such a study, it is necessary to establish the sequence of treatment allowing the administration of a sufficient amount of drugs to induce chronic toxicity and a schedule leading to prolonged survival of animals. In this study, 24 Lewis rats were injected twice a week during four weeks with either free or DNA-linked ADR, and three dose levels were tested: 4, 2 and 1 mg/kg. Our results indicated that the total cumulative dose of ADR should not exceed 8 mg/kg over one month, if prolonged survival is desired. The binding of ADR to DNA seemed also to reduce the acute toxic effects induced by free ADR, in rats. However, such a beneficial effect was not observed when the chronic nephrotoxicity was considered since characteristic renal lesions were observed in all long-term survivors, whatever the dose and the form of ADR received.

Effectiveness of the adriamycin-DNA complex in kidney allograft immunosuppression

The chemotherapeutic effectiveness of the lysosomotropic Adriamycin-DNA complex has been demonstrated experimentally. This study evaluated the immunosuppressive activity of the complex on renal allografts in rats of the Buffalo-Lewis strain. Six rats receiving no treatment served as a control. Five rats received DNA along (at a dose equivalent to that in the complex), seven received the Adriamycin-DNA complex (molar ratio of DNA mononucleotide to Adriamycin, 20:1) and five were given free Adriamycin. Adriamycin, free or linked to DNA, was injected as follows: 2 mg/kg on days 2, 6 and 9 and 1 mg/kg on day 13 after transplantation. The Adriamycin-DNA complex prevented renal allograft rejection in the early postoperative period, by delaying for more than a week, the increase in serum creatinine levels in animals receiving transplants. Histologic examination of renal grafts in these rats confirmed the reduced severity of acute cellular rejection. There was also functional and morphologic evidence of reduced toxicity of Adriamycin when linked to DNA. The beneficial effect of such a drug should be attributed to its lysosomotropic mechanism of activity.

Glomerular fibrinolytic activity during nephrotoxic nephritis

The glomerular fibrinolytic activity (GFA) was measured during the development of glomerulonephritis induced by the intravenous injection of horse or rabbit antiglomerular basement membrane antibodies in rats either untreated or preimmunized with horse or rabbit Ig. A variety of nephritides was produced ranging from proteinuria with no or mild changes in glomerular architecture to severe diffuse proliferative glomerulonephritis with close to 100% crescent formation. GFA was measured on preparations of isolated glomeruli using a radioassay based on lysis of 125I fibrin adsorbed on a solid phase. In some experiments a fibrin plaque technique was also used. Both methods clearly demonstrated a marked increase in GFA with a good correlation between the two sets of results when the glomerular architecture is preserved. The increase in GFA is related both to the severity of the nephritis estimated by the percentage of glomeruli showing crescent formation and to the extent of the fibrin deposits. The results therefore indicate that the persistence of fibrin in the glomeruli and particularly in crescents is not due to a loss of GFA.