Protective effect of elastase on cis-platinum-induced renal toxicity.

The protective effects of elastase (Ela) and fosfomycin against renal toxicity of cis-diamminedichloroplatinum (II) (CDDP) were evaluated in an experimental study using rats. When Ela was used concomitantly with CDDP, the elevation of urinary N-acetyl-beta-D-glucosaminidase levels in the early phase and the sharp fall in these levels in the latter phase were prevented. It was also found that the blood urea nitrogen levels and serum creatinine levels were significantly lowered. Histologically, atrophic and necrotic changes in the tubular epithelium were prevented. The total serum platinum levels showed no change with the addition of Ela; however, the platinum levels in the renal tissues were significantly reduced. These results suggested that Ela is effective against platinum deposits in the renal tissues, particularly in the tubular epithelium, thus protecting the kidneys. On the other hand, fosfomycin demonstrated no such positive results suggestive of a protective effect on the renal function parameters or during histological observation.     

Protective effect of Andrographis paniculata and andrographolide on cyclophosphamide-induced urothelial toxicity

The protective effect of Andrograhis paniculata and andrographolide (ANDLE) against cyclophosphamide (CTX)-induced urothelial toxicity was investigated in this study. Pretreatment of Swiss albino mice with A paniculata extract (10 mg/dose/animal intraperitoneally [ip]) and ANDLE (500 microg/dose/animal ip) could significantly reduce CTX (1.5 nmol/kg body weight)-induced urothelial toxicity. Morphological and histopathological analysis of urinary bladder of CTX-treated mice showed severe inflammation and dark coloration, whereas A paniculata and ANDLE-treated mice showed almost normal bladder morphology. Elevation of urinary protein level (7.33 +/- 0.3 g/L) by CTX administration was reduced by A paniculata (3.78 +/- 0.4 g/L) and ANDLE treatment (4.19 +/- 0.1 g/L). Urinary urea N2 level, which was elevated after 48 hours of CTX administration (24.25 +/- 0.2 g/L) was found to be reduced by the treatment with A paniculata (14.19 +/- 0.5 g/L) and ANDLE (15.79 +/- 0.4 g/L). A decreased level of reduced glutahione (GSH) content in liver (2.81 +/- 0.1 nmol/mg protein) and bladder (1.20 +/- 0.2 nmol/mg protein) after CTX administration was also increased by the treatment with A paniculata (liver: 5.78 +/- 0.3 nmol/mg protein; bladder: 2.96 +/- 0.2 nmol/mg protein) and ANDLE (liver: 5.14 +/- 0.3 nmol/mg protein; bladder: 2.84 +/- 0.2 nmol/mg protein). Production of the proinflammatory cytokine, tumor necrosis factor-alpha, which was elevated during CTX administration, was found to be inhibited by A paniculata and ANDLE treatment. The lowered level of interleukin-2 and interferon-gamma during CTX treatment was elevated by the administration of A paniculata and ANDLE.     

Pharmacokinetics and metabolism of sodium 2-mercaptoethanesulfonate in the rat

The synthetic low-molecular-weight thiol, 2-mercaptoethanesulfonate (mesna), exerts efficient protection against oxazaphosphorine-induced urothelial toxicity by binding the renally excreted and concentrated toxic metabolite(s). In this study, the pharmacokinetics and metabolism of mesna and its disulfide form (dimesna) have been investigated in the intact rat and in several in vitro systems, including isolated perfused organs, freshly isolated cells, and subcellular fractions; the mechanism of reduction of dimesna to form the pharmacologically active thiol mesna has been further studied with purified enzyme preparations. The results may be summarized as follows: (a) After p.o. administration, mesna and dimesna are both absorbed from the intestine, and dimesna undergoes reduction to mesna during intestinal absorption; (b) when present in plasma, mesna is rapidly oxidized to dimesna by a metal-dependent reaction; (c) mesna and dimesna pass unchanged through the hepatic vasculature, are not taken up into liver cells, and are not excreted in bile; (d) in the kidney, dimesna is filtered through the glomeruli and subsequently reabsorbed, whereupon reduction to the pharmacologically active thiol form occurs in the renal tubular epithelium, and the thiol is then reexcreted into the tubular lumen; (e) reduction of dimesna to mesna occurs in intestinal and renal epithelial cells by a mechanism involving the cytosolic enzymes thiol transferase and glutathione reductase. Thus, the formation of the pharmacologically active thiol form from dimesna is associated with the consumption of equimolar concentrations of reduced glutathione.     

Acute systemic toxicity of combined cis-diamminedichloroplatinum and hyperthermia in the rat

To investigate the previously observed increased morbidity and mortality of combined cis-diamminedichloroplatinum (cis-DDP) and hyperthermia, BD IX rats were given 4 mg/kg cis-DDP i.p., waterbath hind leg heating (44°C, 60 min) with resultant whole body hyperthermia, or combined treatment with or without systemic cooling. Cardiac blood and histopathologic sections of kidney, small intestine and liver were examined in rats sacrificed 2, 3 and 5 days after and femur bone marrow 5 days after treatment. In a separate experiment, the effect of systemic hyperthermia on renal function was tested.The most significant finding was a marked increased in cis-DDP induced renal damage by systemic hyperthermia, expressed as elevated creatine levels and quantitatively enhanced proximal tubular necrosis. As both system hyperthermia and cis-DDP can result in primarily altered renal haemodynamics, it is postulated that relative tubular epithelial hypoxia and increased tubular exposure time to cis-DDP due to reduced tubular filtrate flow rate are likely mechanisms for the increased toxicity.     

Protective effect of Thuja occidentalis against radiation-induced toxicity in mice

The effect of Thuja occidentalis against damage induced by gamma radiation was studied. Whole-body exposure of Swiss albino mice to gamma-rays (6 Gy) reduced the total white blood cell count to 1900 cells/mm(3) on the third day, which was elevated to 2050 cells/mm(3) by the administration of alcoholic extract ofT occidentalis (5 mg/dose/animal, intraperitoneally). Six animals from each group were killed after 2, 7, and 11 days of irradiation to detect the bone marrow cellularity and radiation-induced toxicity. The number of bone marrow cells and alpha-esterase positive cells in control animals after 11 days was reduced to 12.2 x 10(6) cells/femur and 693.5/4000 cells, respectively. In T occidentalis-treated animals, bone marrow cellularity was increased to 16.9 x 10(6) cells/femur and alpha-esterase positive cells were 940/4000 cells, a nearly normal level. Alcoholic extract of T occidentalis reduced the elevated levels of GPT and alkaline phosphatase in liver and serum after irradiation. The lipid peroxidation levels were also lowered in the irradiated animals treated with the Thuja extract.     

Inhibition of cis-diamminedichloroplatinum (II) — induced renal toxicity in the rat

Summary The hydroxyl-containing dithiocarbamates, sodium (di(hydroxyethl)-dithiocarbamate (NaY) and sodium N-methyl, N-dithiocarboxy-D-glucamine (NaG), appear to possess definite advantages over sodium diethyldithiocarbamate (DDTC) in reducing the cis-dichlorodiammineplatinum (Cis-Pt)-induced renal damage in rats given Cis-Pt as an IV bolus of 7.5 mg/kg 1 h before the IP administration of the dithiocarbamate. Renal damage, as estimated by blood urea nitrogen (BUN) values and serum creatinine levels, was less at all times up until sacrifice in animals given naY or NaG than in those given DDTC.An even more effective method for suppression of Cis-Pt renal toxicity is to use a combination of procedures. The most efficacious combination involves a 24-h pretreatment with DDTC or NaG plus acetazolamide and normal saline hydration 30 min before administration of Cis-Pt, followed by post-treatment with NaG. With this combination therapy renal function can be almost completely spared. Although DDTC or NaG pretreatment is highly effective when used in conjunction with NaG post-treatment, DDTC or NaG pretreatment alone has no renal sparing effect on renal function or renal platinum accumulation.In experiments in which antidotes were given 1 h after Cis-Pt and the animals were followed up for 75 days, a chronic interstitial nephritis at 75 days, suggesting a persistent cell-mediated immune response to Cis-Pt-induced renal damage, may be the basis for chronically abnormal renal function resulting from Cis-Pt. Treatment with all three dithiocarbamates, NaY, NaG, and DDTC, reduced the intensity of this cellular reaction and also reduced platinum levels in the kidneys.Although NaY and NaG are effective heavy metal chelators and renal function is spared and kidney platinum levels are substantially reduced by the dithiocarbamates, no parallel loss of antineoplastic activity by Cis-Pt on the rat Walker carcinoma was observed. Since the dithiocarbamates have no known human toxicity that would disqualify their clinical use, phase 1 clinical trials are indicated.This work was supported in part by the Natural Sciences Committee of the College of Arts and Sciences, Vanderbilt University     

Influence of methylprednisolone on antitumor effect of cis-diamminedichloroplatinum (II)

To elucidate the influence of methylprednisolone (MPL) on the antitumor effect of cis-diamminedichloroplatinum (II) (CDDP), experimental chemotherapy of CDDP with or without MPL was performed. A human breast carcinoma, MX-1 serially transplanted into nude mice was treated with CDDP in doses of 1.5 and 3.0 mg/kg in schedule of q4d X 3 ip. KKN-1, a syngeneic fibrosarcoma of BALB/c transplanted into BALB/c +/+ or BALB/c nu/nu mice, was treated with CDDP in doses of 3 or 6 mg/kg in schedule of qd X 1 ip. In the combination of MPL, 20 mg of MPL per kg was administered ip three hours before CDDP treatment. Although some decrease of antitumor effect of CDDP was observed by combination with MPL, no statistically significant difference was noted between group given CDDP alone and those given CDDP plus MPL. It was concluded that the use of MPL is reasonable to prevent the severe emesis caused by CDDP when this adverse effect is resistant to other antiemetic agents.     

Modification of the bone marrow toxicity of cis-diamminedichloroplatinum(II) in mice by diethyldithiocarbamate

It has been shown that cis-platinum-induced nephrotoxicity in rats can be inhibited by diethyldithiocarbamate (DDC). We report here the bone marrow protective properties of DDC in hybrid (C57BL X BALB/c) mice exposed to single and fractionated doses of cis-platinum. Relatively nontoxic doses of DDC afford maximum protection, using that dose of cis-platinum that would result in the death of 50% of the mice within 9 days as an end point (dose-limiting gut toxicity in mice), when injected 0.5 to 2 hr following i.p. cis-platinum treatment. Survivals of colony-forming units in spleen, nucleated bone marrow cells, and peripheral white blood cell were used to assess the bone marrow protective properties of DDC following both single and fractionated doses of cis-platinum. A dose modification factor of 3.2 (based on colony-forming units in spleen survival) was obtained when DDC (1000 mg/kg) was injected into mice 0.5 hr after graded doses of cis-platinum. When fractionated doses of cis-platinum were used (6 mg/kg on Days 0, 10, 20, and 30), the survival of colony-forming units in spleen was markedly enhanced if the animals were rescued with DDC 0.5 hr following each cis-platinum dose. When bone marrow cellularity was measured immediately before and 2 days after each dose of cis-platinum, a similar pattern of depression and recovery was noted whether DDC was present or not; however, the depression was less marked in mice rescued with DDC. When peripheral white blood cell counts were monitored, the nadir and recovery were similar in the presence or absence of DDC; however, recovery occurred sooner in the animals that had received DDC. Our data support the ability of DDC to modify the bone marrow toxicity of cis-platinum in normal mice. Experiments are in progress in tumor-bearing animals exploring the differential protection afforded by DDC between bone marrow and tumor.     

Protective effect of amifostine against toxicity of paclitaxel and carboplatin in non-small cell lung cancer

Aim: In this study we determined the protective role of amifostine against the side effects of the combination of paclitaxel and carboplatin in patients with non-small cell lung cancer (NSCLC). Patients and Methods: Chemo-naive patients with NSCLC were eligible. Thirty-eight patients were randomized to receive paclitaxel 175 mg/m² and carboplatin AUC=6 with amifostine 910 mg/m² (group B) or chemotherapy alone (group A). The occurrences of hematologic, neurologic, cardiologic toxicities, and ototoxicity were evaluated. Results: All patients completed the six scheduled cycles of therapy. A total of 114 cycles of chemotherapy was given in both groups. Neutropenia grade 3–4 was observed in 11 cycles (9.6%) in group A and 19 cycles (16.6%) in group B (p=0.16). Paresthesia grade 1 or 2 was observed in 18 of 19 patients of group A and in 8 of 19 patients of group B, following the sixth cycle of chemotherapy (p=0.018). Two patients of group B and nine patients of group A suffered from sensory motor impairment grade 2 (p=0.029). There was no clinical evidence in any patient for deterioration in cardiac function. Asymptomatic and transient sinus bradycardia or ventricular premature beats developed in four patients. None of the patients reported vertigo, tinnitus, or hearing loss. Conclusion: The addition of the amifostine to the combination of paclitaxel and carboplatin may prevent or reduce the incidence of neurotoxicity in the treatment of NSCLC. Amifostine does not appear to have a preventive role in neutropenia.     

High-dose 7-hydroxymethotrexate: Acute toxicity and lethality in a rat model

To elucidate mechanisms for methotrexate (MTX)-induced renal and hepatic toxicity, we investigated the acute effects of bolus plus continuous infusion of up to 0.4 g/kg 7-hydroxymethotrexate (7-OH-MTX) in the rat. We demonstrate for the first time in any species the occurrence of acute lethal toxicity within a few hours after 7-OH-MTX administration. Serum concentrations of 7-OH-MTX measured at the time of death were 1.4 mM (mean), about one-half of those achieved in some patients after infusion of high-dose MTX (HD-MTX) in the clinic. The data suggest an approximate LD50 (the dose lethal to 50% of the study population) of 0.3 g/kg and a steep dose/ lethality curve for 7-OH-MTX. Moreover, acute renal and hepatic toxicity occurred as evidenced by severe morphological findings and increased serum levels of creatinine and liver transaminases. In all rats subjected to continuous infusion of 7-OH-MTX, yellow microscopic precipitations were apparent in the kidney tubules. Crystallization was also seen in bile ducts of the liver in some of the rats. These results further support that the formation of 7-OH-MTX is disadvantageous and that reported attempts to prevent its formation during MTX treatment are warranted.     

Biochemical consequences of 5-fluorouracil gastrointestinal toxicity in rats; effect of high-dose uridine

Selective protection of the normal host tissues from the toxic effects of anticancer agents would allow the use of higher, probably more effective, doses of the drugs. It has been demonstrated that delayed high-dose uridine administration after 5-fluorouracil decreases the extent of myelosuppression and causes faster regeneration of the bone marrow. We studied the biochemical consequences of the gastrointestinal toxicity caused by 5-fluorouracil and the potential of high-dose uridine treatment to influence these adverse effects. 5-Fluorouracil caused dose-related decreases in the biochemical parameters (thymidine kinase, sucrase, maltase, alkaline phosphatase) selected as early markers of the impaired metabolic activity of the intestinal mucosa. The nadir of the biochemical changes was reached between 24 h and 72 h after 5-fluorouracil treatment, and complete regeneration of the mucosa took 6–7 days. Delayed high-dose uridine administration failed to mitigate the severity of the gastrointestinal damage that ensued after 5-fluorouracil treatment, but caused significantly earlier regeneration of the mucosa.     

Effect of diethyldithiocarbamate on toxicity of doxorubicin, cyclophosphamide and cis-diamminedichloroplatinum (II) on mice haemopoietic progenitor cells

DBA/2NCr1BR F1 mice received a single i.v. injection of doxorubicin (4.32, 7.20 or 12.00 mg kg-1), cyclophosphamide (70, 120 or 200 mg kg-1) or cis-diamminechloroplatinum (5.4, 9.0 or 15.0 mg kg-1), alone or 2 h before an i.p. injection of 1,000 mg kg-1 of diethyldithiocarbamate (DDTC). Twenty-four hours after, survival of bone marrow colony forming units-spleen and granulocyte-macrophage colony forming cells, was determined. On the whole, administration of DDTC reduced the toxic effect of the three anticancer drugs on haemopoietic progenitors. The effect was in general more evident at the lower than at the higher doses of the antitumour drugs.     

Evaluation of the effect of furosemide on ultrafilterable platinum kinetics in patients treated with cis-diamminedichloroplatinum

Summary It has been reported that furosemide can prevent platinum nephrotoxicity by dilution of the toxic drug in the tubule or by another unknown mechanism. To evaluate its influence on ultrafilterable platinum pharmacokinetics, we undertook a randomized prospective trial of cis-diamminedichloroplatinum (CDDP) (80 mg/m² by a 20-min infusion) administered to 20 patients with hydration-induced diuresis. Ten patients received 20 mg/m² furosemide 1 h before CDDP administration, and 10 patients received no diuretic drug. Plasma and urinary pharmacokinetics of platinum and creatinine were compared in both groups of patients. Plasma total and ultrafilterable platinum was always higher in the furosemide group. However, protein binding, urinary concentrations, cumulative urinary excretion, renal clearance and creatinine clearance/renal clearance ratio (fractional clearance) were not statistically different. Moreover, the fractional clearance was successively lower, equal and higher than one in both groups. These results suggest that: (1) furosemide probably causes water depletion leading to a rise in plasma concentrations; (2) its protection by a pharmacokinetic interaction is doubtful, since all other parameters (especially urinary parameters) are not significantly modified; (3) renal clearance and fractional clearance suggest a bidirectional transport of platinum in the tubule not influenced by the diuretic drug.     

Studies on hemotoxicity of cyclophosphamide, doxorubicin and cis-diamminodichloroplatinum combined with sodium-2-mercaptoethane sulfonate

The possible protective action of sodium-2-mercaptoethanesulfonate (mesna) on hemotoxicity induced by anticancer drugs was tested in normal mice. Mesna (100 mg/kg b.w.) was injected i.v. 1 h before the i.v. administration of cyclophosphamide (10, 120, and 200 mg/kg b.w.), doxorubicin (4.32, 7.2, and 12 mg/kg b.w.) and cis-diamminedichloroplatinum (5.4, 9, and 15 mg/kg b.w.). Results show that in this experimental model mesna does not seem to protect against toxicity of the tested anticancer drug on hemopoietic progenitor cells.     

The effect of captopril on renal function in patients during the first cis-diamminedichloroplatinum II infusion

Summary On the assumption that hemodynamic changes in renal blood flow are the initial expression of cis-diamminedichloroplatinum (CDDP)-related nephrotoxicity, we treated patients with metastatic non-seminomatous testicular carcinoma during CDDP infusion with captopril. This angiotensin-converting enzyme inhibitor significantly attenuated the initial decrease in effective renal plasma flow and can probably be used to protect the kidneys against CDDP-induced nephrotoxicity.     

Adverse effect of cis-diamminedichloroplatinum II (CDDP) on porphyrin metabolism in man

Summary The possible effect of cisplatin on porphyrin metabolism was studied in 25 patients with various malignancies treated with high-dose cis-diamminedichloroplatinum. Haematocrit, red blood cells, haemoglobin, white blood cells, platelets and reticulocytes together with coproporphyrin and protoporphyrin in red blood cells were determined before each course of chemotherapy in all patients. In addition, coproporphyrin, uroporphyrin, -aminolevulinic acid, and porphobilinogen were determined in the urine just before and 24 h after each course of treatment.Cisplatin administration was followed by a significant suppression of coproporphyrin and protoporphyrin in red blood cells and coproporphyrin, uroporphyrin, -aminolevulinic acid and porphobilinogen in urine. The changes observed paralleled similar changes in haematocrit, red blood cells and haemoglobin, strongly suggesting that cisplatin-induced anaemia may be due to a blocking effect of the drug affecting one or more enzymatic steps in the biosynthesis of porphyrins and haem. A moderate fall in the white blood cell count and a mild fall in platelets together with a steady increase of reticulocytes were also observed during treatment.     

The effect of tumor size and lymph node status on breast carcinoma lethality

BACKGROUND: It has long been known that both tumor size and the presence of malignant disease in the regional lymph nodes are indicators of outcome for patients with invasive breast carcinoma; however, the way in which these two characteristics could be integrated into an overall assessment of prognosis has not been obvious. METHODS: Kaplan-Meier survival estimates (15 years) according to tumor size and lymph node status were obtained for women with invasive breast carcinoma who were observed at the University of Southern California/Van Nuys Breast Center (Van Nuys, California) or at Massachusetts General Hospital (Boston, Massachusetts). RESULTS: To isolate the individual contributions to death made by tumor size and lymph node status, data were sorted according to both of these variables. For women with tumors of equivalent size, lethality increased with increasing number of positive lymph nodes, such that there was an extra approximately 6% chance of death associated with each positive lymph node. For women with equivalent lymph node status, tumor size was associated with increased lethality, such that each millimeter of tumor diameter was associated with an additional approximately 1% chance of death. The overall lethality was equal to the sum of the contribution from lymph node status and the contribution from tumor size, and this finding led to the creation of a new technique (the Size+Nodes method) for predicting outcome. CONCLUSIONS: The Size+Nodes method was shown to be capable of accurately estimating the risk of death due to invasive breast carcinoma from information on the size of the primary tumor and the number of positive lymph nodes. In addition, this method was used to stratify women into groups according to breast carcinoma lethality. In contrast, classification of women according to lymph node positivity, T status, or disease stage created groups with wide and overlapping levels of lethality.