Pain and somatic symptoms are sequelae of sexual assault: results of a prospective longitudinal study.

BACKGROUND: Cross-sectional studies have shown that chronic musculoskeletal pain and somatic symptoms are frequently reported by sexual assault (SA) survivors; however, prospective studies examining pain and somatic symptoms in the months after SA have not been performed. METHODS: Women SA survivors 18 years of age or older who presented for care within 48 h of SA were recruited. Pain in eight body regions (head and face, neck, breast, arms, abdomen, back, genital and pelvic, and legs) and 21 common somatic symptoms (e.g., headache, nausea, insomnia, persistent fatigue) were assessed (0-10 numeric rating scale in each body region) at the time of presentation, 1-week, 6-week and 3-month interview. Post-traumatic stress disorder (PTSD) symptoms were assessed at the 6-week and 3-month interview. RESULTS: Clinically significant new or worsening pain (CSNWP) symptoms were common among study participants 6 weeks after SA [43/74, 58% (95% CI, 47-69%)] and 3 months after SA [40/67, 60% (95% CI, 48-71%)] and generally occurred in regions not experiencing trauma. Women SA survivors also experienced an increased burden of many common somatic symptoms: 8/21 (38%) and 11/21 (52%) common somatic symptoms showed a significant increase in severity 6 weeks and 3 months after SA, respectively. Correlations between PTSD, CSNWP and somatic symptoms were only low to moderate, suggesting that these outcomes are distinct. CONCLUSIONS: New and/or clinically worsening pain and somatic symptoms, lasting at least 3 months, are sequelae of SA. Further studies investigating pain and somatic symptoms after SA are needed.

Increased susceptibility to erythrocyte C5b-9 deposition and complement-mediated lysis in chronic renal failure.

BACKGROUND: Decreased red blood cell survival contributes to the anemia of chronic renal failure patients. Because patients on chronic dialysis therapy are frequently exposed to excessive complement activation, we investigated the susceptibility of this patient population to erythrocyte C5b-9 deposition, complement-mediated lysis, and ghost formation. METHODS: We developed a flow cytometric assay using antibodies to both glycophorin and the C5b-9 complex to detect C5b-9 deposition on intact erythrocytes and erythrocyte ghosts. Serum C5b-9 levels and C5b-9 deposition on erythrocyte ghosts were measured by enzyme-linked immunosorbent assay. RESULTS: A significant increase in C5b-9 deposition on intact erythrocytes was demonstrated in patients with advanced chronic renal failure (2.2 +/- 0.5%) and in patients on chronic maintenance hemodialysis (2.3 +/- 0.4%) compared with normal volunteers (0.9 +/- 0.1%, P = 0.005 vs. chronic renal failure, P < 0.001 vs. chronic hemodialysis patients). There was also a significantly higher percentage of C5b-9-positive erythrocyte ghosts in patients with advanced chronic renal failure (20.6 +/- 5%) and in chronic hemodialysis patients (15.5 +/- 3.1%) compared with normal controls (2.6 +/- 0.9%, P < or = 0.001 vs. advanced chronic renal failure and chronic hemodialysis patients). Treatment of erythrocyte preparations with cobra venom factor, which activates the complement cascade, resulted in dramatic increases in the percentages of C5b-9-positive erythrocyte ghosts in patients with chronic renal failure (49.9 +/- 6.9%) and in chronic hemodialysis patients (45.0 +/- 4.2%) compared with normal volunteers (22.3 +/- 2.7%, P < 0.001 vs. chronic renal failure and chronic hemodialysis patients). Erythrocyte membrane expression of the complement regulatory proteins CD59 and CD55 did not significantly differ between normal controls and hemodialysis patients. Plasma C5b-9 levels after cobra venom factor stimulation were higher in chronic renal failure patients (538 micrograms/ml) compared with normal controls (345 micrograms/ml, P < 0.001). CONCLUSIONS: Patients with chronic renal failure and on hemodialysis therapy are susceptible to erythrocyte C5b-9 deposition with subsequent lysis and ghost formation. Susceptibility to complement-mediated erythrocyte injury may contribute to the anemia of chronic renal disease.

Elevated plasma glycocalicin levels and decreased ristocetin-induced platelet agglutination in hemodialysis patients.

A bleeding diathesis caused by platelet dysfunction is a major cause of morbidity and mortality in patients with uremia. Platelet adhesion to vascular subendothelium is defective in uremia and depends on the interactions of the platelet glycoprotein (GP) Ib/IX complex with the vascular wall. We measured levels of platelet surface GPIb, platelet surface GPIX, plasma glycocalicin (a product of enzymatic cleavage of GPIb), and ristocetin-induced platelet agglutination (RIPA) in patients undergoing chronic hemodialysis compared with patients undergoing peritoneal dialysis and healthy controls. Patients undergoing chronic maintenance hemodialysis have higher levels of platelet surface expression of GPIb (187+/-10 fluorescent units; P < 0.001) than either healthy controls (120+/-4 fluorescent units; P < 0.001) or patients undergoing peritoneal dialysis (127+/-5 fluorescent units; P < 0.001). Similar changes were observed in platelet surface GPIX. Plasma glycocalicin levels were elevated in chronic hemodialysis patients (71+/-5 nmol/L) compared with healthy controls (36+/-3 nmol/L; P < 0.001). Plasma glycocalicin levels also increased progressively throughout the hemodialysis procedure. The slope of RIPA was significantly lower in chronic hemodialysis patients (46+/-3) than in either healthy controls (67+/-4; P < 0.05) or peritoneal dialysis patients (62+/-2; P < 0.05). In conclusion, patients undergoing chronic maintenance hemodialysis have increased plasma glycocalicin levels and decreased RIPA, which may contribute to diminished platelet adhesion to vascular subendothelium and increased bleeding associated with uremia.

Increased reticulated platelets in dialysis patients.

The purpose of this study was to measure the percent reticulated platelets and platelet counts in patients on chronic hemodialysis, peritoneal dialysis and normal volunteers. The relationship between the percent reticulated platelets and the platelet count can then be used to determine the rate of platelet turnover. Platelet rich plasma was obtained, platelets were fixed and incubated with thiazole orange and analyzed for the percent reticulated platelets by flow cytometry. Normal controls had a mean of 2.77 +/- 0.17% reticulated platelets while peritoneal dialysis patients had a mean percent reticulated platelets of 6.92 +/- 0.68 (P < 0.00001). Chronic hemodialysis patients had a mean percent reticulated platelets of 8.21 +/- 0.36 (P < 0.00001 vs. normal controls and P = 0.05 vs. peritoneal dialysis patients). Platelet counts did not differ significantly among the three groups. The identity of reticulated platelets was confirmed in experiments measuring platelet specific glycoproteins, experiments using RNase, and in mixing experiments with normal and uremic platelets and plasma. We conclude that dialysis patients have a marked increase in circulating reticulated platelets compared to normal controls, indicating accelerated platelet turnover. Increased platelet activation and turnover may contribute to the qualitative platelet dysfunction observed in dialysis patients.

Soluble complement receptor 1 inhibits both complement and granulocyte activation during ex vivo hemodialysis.

Hemodialysis with cellulosic membranes results in both complement and granulocyte activation. We investigated the effects of soluble complement receptor 1 (sCR1), a potent complement inhibitor, on both complement and granulocyte activation in an ex vivo model of dialysis. Measurements were made of complement activation (radioimmunoassay for C3a desArg) as well as granulocyte activation (flow cytometric measurements of reactive oxygen species production, granulocyte CD11b/CD18 (MAC-1) expression and CD62L (L-selectin) expression). sCR1 completely abolished the generation of plasma C3a desArg during ex vivo hemodialysis. Without sCR1, C3a desArg levels rose from 968 +/- 373 ng/ml to 4961 +/- 40 ng/ml by the end of the ex vivo procedure (p < 0.001). sCR1 also completely inhibited MAC-1 upregulation and L-selectin shedding from granulocytes during ex vivo hemodialysis. With sCR1 there was still a statistically significant increase in granulocyte reactive oxygen species production (from 2.42 +/- 0.1 fluorescence channels to 6.47 +/- 0.7 fluorescence channels, p < 0.01) but a 50% inhibition when compared with experiments without sCR1 (3.15 +/- 0.5 to 11.2 +/- 1.9, p < 0.01). We conclude that sCR1 completely abolishes complement activation and changes in granulocyte cell adhesion molecules during ex vivo hemodialysis with cellulosic membranes. sCR1 partially inhibits granulocyte reactive oxygen species formation.

HPLC and 31P NMR characterization of the reaction between antitumor platinum agents and the phosphorothioate chemoprotective agent S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721).

In prior studies, we examined the effects of the radioprotective and chemoprotective agent WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] on the in vivo biotransformation of the cisplatin [cis-diamminedichloroplatinum(II)] analog ormaplatin [(d,I)trans-1,2-diaminocyclohexanetetrachloroplatinum(IV), Pt(dach)Cl4, (formerly called tetraplatin)]. Those data suggested that a direct interaction between WR-2721 and ormaplatin and/or the corresponding Pt(II) drug, Pt(dach)Cl2, may be occurring in vivo. This would be in contrast to the generally accepted hypothesis that WR-2721 is a prodrug that must first be converted by alkaline phosphatase to a free thiol compound, WR-1065, before any appreciable reactivity would be evident. However, the major biotransformation product observed in the peritoneal fluid, plasma, and all tissues was Pt(dach)(WR-1065). We report here on further investigations into the in vitro reactivity of Pt(dach) compounds with WR-2721 and WR-1065. Separation of reaction products resulting from incubation of Pt(dach)(malonato) with either WR-2721 or WR-1065 under physiological conditions gave profiles that were indistinguishable by reverse phase HPLC and cation exchange HPLC at two different pHs. 31P NMR characterization of the dephosphorylation of WR-2721 revealed essentially no loss of inorganic phosphate for up to 24 hr when incubated in unbuffered water at 30 degrees. In contrast, when incubated with a 1:1 molar ratio of cisplatin under the same conditions, the WR-2721 signal was decreased markedly in the first 5 min, and had disappeared almost completely by 1 hr. The signal corresponding to inorganic phosphate increased in parallel to the decrease in the WR-2721 signal. No intermediate formation of a complex containing both platinum and phosphate could be detected at any time. These data suggest that the reaction between WR-2721 and platinum complexes results in rapid dephosphorylation of WR-2721, and, consequently, that the reaction products formed with either WR-2721 or WR-1065 and Pt(II) complexes are identical.

Effect of the chemoprotective agent WR-2721 on disposition and biotransformations of ormaplatin in the Fischer 344 rat bearing a fibrosarcoma.

The effects of the phosphorothioate agent, WR-2721, have been investigated with respect to the biotransformations of ormaplatin in the Fischer 344 rat bearing a transplanted fibrosarcoma. A number of different paradigms of dosing route and schedule for the administration of the two agents have been investigated. In the first group of experiments, WR-2721 (200 mg/kg, i.p.) was administered 30 min before ormaplatin (12.5 mg/kg, i.p.), and then peritoneal fluid, plasma, and tissues were harvested at 30 min after the ormaplatin administration. Our results suggest that a significant interaction between WR-2721 and ormaplatin is occurring in the peritoneal cavity. The interaction was evident in terms of both effects on distribution and disposition of total platinum and in alterations of the profiles of biotransformation products formed in the various tissues and fluids. Plasma protein binding of ormaplatin was decreased by 50% in the presence of WR-2721. Total platinum in the spleen was decreased by 66% and in the liver by 50%. There were no trends among the findings that would indicate any selectivity between tumor and nontumor tissue with respect to the effects of WR-2721 on the parameters measured. Subsequent investigations examined the effects of dosing the WR-2721 by the i.v. route while continuing with the i.p. administration of the ormaplatin. WR-2721 was administered either 30 or 5 min before the ormaplatin, and the plasma and tissues were harvested at 15, 30, or 60 min after ormaplatin administration. The reverse-phase HPLC peak, which behaved chromatographically as a Pt(dach)(WR-1065) standard, was less prominent after the i.v. administration of WR-2721 than it was after i.p. administration under any of the paradigms tested. There was again no evidence for selectivity between tumor and nontumor tissue in the findings from any of the paradigms. It is concluded that if WR-2721 is capable of selectively protecting nontumor tissue from the toxicities of platinum-based chemotherapy, it is doing so by some mechanism other than its selective uptake into normal tissue and subsequent nonspecific inactivation of any reactive cytosolic platinum species formed. Other possible mechanisms are briefly discussed.

Organ-specific biotransformation of ormaplatin in the Fischer 344 rat.

We examined the intracellular biotransformation products of ormaplatin [(d,l-trans)1,2-diaminocyclohexanetetrachloroplatinum(IV)] (formerly called tetraplatin) in liver, kidney, spleen, small intestine, and plasma of the adult male Fischer 344 rat. Previous studies have established that the rank order of ormaplatin toxicity in Fischer 344 rats is spleen approximately gastrointestinal tract > kidney >> liver. Animals were given tritium-labelled drug i.v. at 12.5 mg/kg, and tissues were harvested 30 min later. The kidney was found to concentrate total and cytosolic platinum to a greater extent than any of the other tissues. The absolute amount of cytosolic platinum, in micrograms per gram tissue, that was irreversibly bound to protein and/or other macromolecules was also greatest in the kidney. However, when the amount bound was expressed as a percentage of the total cytosolic platinum, the kidney was significantly lower than any other tissue. Of the various low molecular mass platinum biotransformation species characterized, by far the most abundant were complexes of platinum with the sulfur-containing molecules cysteine, methionine, and glutathione (GSH). There was more of the methionine complex in the blood plasma than in any of the tissues except for the spleen. No significant differences among the tissues were detected for the dichloro, cysteine, methionine, or the GSH complexes. The tritium-labelled diaminocyclohexane (DACH) carrier ligand appeared to remain stably bound to the platinum while in the plasma, as there was less free DACH ligand detected in plasma ultrafiltrate than in any tissue ultrafiltrate. Among the tissues, the free DACH levels were in the range of 20% of the radioactivity recovered from the HPLC column and were not significantly different. Consequently, neither biodistribution nor tissue-specific biotransformation of ormaplatin provides a ready explanation for the tissue specificity of ormaplatin toxicity in Fischer 344 rats. However, in kidney there was much less of the reactive PtCl2(DACH) species than has previously been reported for the corresponding Pt(NH3)2Cl2 species in cisplatin-treated rats. Thus, these data suggest a possible explanation for differences in nephrotoxicity induced by cisplatin versus that by ormaplatin.

Effects of aprotinin on complement and granulocyte activation during ex vivo hemodialysis.

Hemodialysis with cellulosic membranes results in complement activation, granulocytopenia, and granulocyte activation. To further investigate the relationship between complement activation and granulocyte activation, we developed a model of ex vivo hemodialysis with blood flow, dialysate flow, and dialysate composition similar to in vivo hemodialysis. We used this model to investigate the effects of aprotinin, a potent serine protease inhibitor frequently used as an anti-inflammatory agent during cardiopulmonary bypass surgery, on both complement and granulocyte activation. Seven normal human volunteers were phlebotomized for ex vivo hemodialysis on two occasions each, one with and once without 800,000 kallikrein inhibitor units of aprotinin added to the circuit. Measurements were made of complement activation (radioimmunoassay for C3a desArg and C5a desArg), as well as granulocyte activation (flow cytometric measurements of reactive oxygen species (ROS) production, granulocyte CD11b-CD18 [MAC-1, CR3] expression, and CD62-L [L-selectin] expression). Statistically significant elevations in C3a desArg levels occurred by 10 minutes and reached a maximum of 5,367 +/- 712 ng/mL by 60 minutes after the initiation of ex vivo hemodialysis. Plasma C5a levels were elevated to 236 +/- 32 ng/mL at 60 minutes compared with 45 +/- 15 ng/mL predialysis. Aprotinin was able to significantly inhibit dialysis-induced C3a generation (peak 2,456 +/- 572 ng/mL at 60 minutes) as well as C5a generation (86 +/- 23 ng/mL at 60 minutes). During ex vivo hemodialysis, there was also a significant increase in granulocyte ROS production, MAC-1 upregulation, and L-selectin downregulation. Changes in granulocyte activation were not affected by the administration of aprotinin.(ABSTRACT TRUNCATED AT 250 WORDS)

Kt/V, nutritional parameters, serum cortisol, and insulin growth factor-1 levels and patient outcome in hemodialysis.

Despite many technical advances in dialysis care, morbidity and mortality in chronic hemodialysis patients in the United States remains high. In this study, we analyzed the effects of Kt/V, nutritional parameters (serum albumin level, triceps skin-fold thickness, mid-arm muscle circumference, and normalized protein catabolic rate), and predialysis serum cortisol and insulin growth factor-1 levels on predicting morbidity and mortality. The cohort studied consisted of 52 patients recruited from a single outpatient dialysis facility. Cox proportional hazards modeling indicated that only Kt/V predicted subsequent mortality (P = 0.02), while both predialysis cortisol levels (P = 0.03) and Kt/V (P = 0.03) predicted hospitalization. Kaplan-Meier analysis demonstrated that the ability of cortisol levels to predict hospitalization was largely confined to the group with values greater than 22 micrograms/dL predialysis. High serum cortisol levels were correlated with low serum albumin levels and a trend toward low triceps skin-fold thickness and higher normalized protein catabolic rate, suggesting a catabolic state. Both predialysis serum cortisol and insulin growth factor-1 levels were higher than those in age- and sex-matched normal human controls. These results demonstrate the importance role of Kt/V in predicting subsequent hospitalization rates and mortality, and that high predialysis serum cortisol levels correlate with a high hospitalization rate.

Intradialytic granulocyte reactive oxygen species production: a prospective, crossover trial.

By the use of flow cytometric techniques, this prospective, randomized crossover study was designed to analyze intradialytic granulocyte reactive oxygen species (ROS) formation in whole blood with complement-activating and noncomplement-activating hollow fiber membranes. Dialysis with a complement-activating membrane resulted in a 6.5-fold increase in granulocyte hydrogen peroxide production 15 min after dialysis initiation and remained significantly elevated (P < 0.01) through the first 30 min with this membrane in comparison to both predialysis values and simultaneous values with a noncomplement-activating membrane. Further studies demonstrated that blood obtained at 15 min with a complement-activating membrane generated significantly less granulocyte ROS production in response to Staphylococcus aureus incubation than blood obtained either predialysis or at the same time in dialysis with a noncomplement-activating membrane. Both complement-activating and noncomplement-activating dialysis membranes caused slightly decreased granulocyte responsiveness to phorbol myristate acetate. It was concluded that hemodialysis with complement-activating membranes results in increased granulocyte ROS production and decreased responsiveness to S. aureus challenge during the dialysis procedure. These results document the potential role of ROS in hemodialysis-associated pathology and susceptibility to infection.

Detection of granulocyte reactive oxygen species formation in whole blood using flow cytometry.

We have developed a technique for analysis of granulocyte reactive oxygen species formation in whole blood using flow cytometry and two color immunofluorescence. This technique relies upon the use of specific fluorescent dye (LDS-751) to stain nucleated cells, eliminating erythrocytes from analysis. Using LDS-751, forward angle light scatter, and 90 degrees side scatter, a granulocyte gate, monocyte gate, and lymphocyte gate were identified. Analysis with multiple FITC conjugated monoclonal antibodies demonstrated greater than 95% purity of a flow cytometrically identified granulocyte population in whole blood without physical manipulation of the blood. Utilizing 2'7' dichlorofluorescein diacetate (DCFH-DA), we were able to measure granulocyte intracellular reactive oxygen species production. Dose response curves were obtained for the effect of granulocyte agonists phorbol myristate acetate, FMLP, and heat fixed Staphylococcus aureus on reactive oxygen species production. The techniques described in this paper should be useful for measuring granulocyte activation in vivo with flow cytometry.

In vivo and in vitro effects of helenalin on mouse hepatic microsomal cytochrome P450.

Helenalin, a natural plant product with significant antitumor activities, decreased male BDF1 mouse hepatic microsomal cytochrome P450 contents in vivo and in vitro. A single i.p. dose of 25 mg helenalin/kg body weight significantly (P less than 0.05) decreased microsomal cytochrome P450 contents and inhibited cytochrome P450-dependent mixed-function oxidase activities within 1-2 hr post-exposure. Helenalin (1.0 mM) decreased microsomal cytochrome P450 contents in vitro by 11% in the absence of NADPH and by 32% in the presence of NADPH. These in vitro and in vivo decreases in cytochrome P450 were accompanied by comparable decreases in total microsomal heme contents. Helenalin (1.0 mM) increased mouse hepatic microsomal oxygen consumption and NADPH utilization by 3.2 and 5.4 nmol/min/mg protein respectively. Helenalin (1.0 mM) significantly (P less than 0.05) increased microsomal lipid peroxidation in vitro, and this helenalin-induced increase in lipid peroxidation was inhibited completely by the addition of 0.05 mM EDTA. However, microsomal cytochrome P450 contents were equally affected by helenalin in the presence or absence of EDTA, suggesting that lipid peroxidation did not contribute to the helenalin-induced decrease in cytochrome P450. The addition of 0.05 mM hemin to microsomes treated in vitro with 1.0 mM helenalin resulted in a 58% recovery of cytochrome P450 contents. This ability of hemin to reconstitute cytochrome P450 in helenalin-treated microsomes suggests that helenalin produced a selective loss of heme from the cytochrome P450 holoprotein, and that the resulting cytochrome P450 apoprotein remained intact after helenalin treatment. The increased loss of microsomal cytochrome P450 produced by helenalin in the presence of NADPH suggests that a helenalin metabolite may be responsible for heme loss and the in vitro destruction of cytochrome P450.

Comparisons of tetrachloro(d,l-trans)1,2-diaminocyclohexane-platinum(IV) biotransformations in the plasma of Fischer 344 rats at therapeutic and toxic doses.

Plasma biotransformations of tetrachloro(d,l-trans)1,2-diaminocyclohexaneplatinum(IV) (tetraplatin) were determined in vivo at both therapeutic (3 mg/kg) and toxic (12 mg/kg) doses in Fischer 344 rats. Tetraplatin was rapidly converted to dichloro(d,l-trans)1,2-diaminocyclohexaneplatinum(II) [PtCl2(dach)]. This conversion was complete at the earliest time measured (7.5 min) at the therapeutic dose, but some unreacted tetraplatin was detectable in the circulation at the toxic dose. Three other major biotransformation products were observed in plasma: (d,l-trans)1,2-diaminocyclohexaneaquachloroplatinum(II) [Pt(H2O)(Cl)(dach)]+, the Pt-methionine complex, and another biotransformation product tentatively identified as either the Pt-cysteine or Pt-ornithine complex. Several other minor plasma biotransformation products were detected. Two of these were most likely formed intracellulary from tetraplatin. Two or more other platinum complexes appeared to lack the diaminocyclohexane carrier ligand and were most likely formed intracellulary by trans-labilization of the carrier ligand. Tetraplatin, PtCl2(dach), and [Pt(H2O)(Cl)(dach)]+ all rapidly disappeared from the circulation. The other biotransformation products were persistent through at least 3 h and could be responsible for the delayed toxicity of tetraplatin. Although some minor differences were observed between tetraplatin biotransformations at the toxic vs therapeutic doses, most biotransformation products were simply present at much greater concentrations at the toxic dose than at the therapeutic dose. Thus, our data suggest that dose-dependent differences in tetraplatin toxicity are probably attributable to the amount, rather than the type, of biotransformation products present in the plasma.

Effects of diethyldithiocarbamate (DDTC) on the plasma biotransformations of tetrachloro(d,l-trans)-1,2-diaminocyclohexaneplatinum(IV) (tetraplatin) in Fischer 344 rats.

We have studied the effects of diethyldithiocarbamate (DDTC) on the biotransformations of toxic doses of tetrachloro (d,l-trans)1,2-diaminocyclohexaneplatinum(IV) (tetraplatin) in Fischer 344 rats. In animals not treated with DDTC, tetraplatin was rapidly converted to dichloro(d,l-trans)1,2-diaminocyclohexaneplatinum(II) [PtCl2(dach)]. Subsequent biotransformations included the transient formation of the (d,l-trans)1,2-diaminocyclohexane-aquachloroplatinum(II) [Pt(H2O)(Cl)(dach)]+ complex, followed by formation of the platinum (Pt)-methionine and either Pt-cysteine or Pt-ornithine complexes. Significant amounts of free (d,l-trans) 1,2-diaminocyclohexane (dach) were observed in plasma as a result of intracellular trans-labilization reactions. DDTC caused a marked decrease in both total and protein-bound platinum in the circulation. A significant increase in the plasma concentration of free dach was also observed as a result of formation of the Pt(DDTC)2 complex. Some of the free dach could have arisen from intracellular reactions with DDTC, but the displacement of platinum from plasma proteins was more than sufficient to account for the increase in free dach in the circulation. DDTC treatment also decreased plasma concentrations of tetraplatin, PtCl2(dach), [Pt(H2O)(Cl) (dach)]+, the Pt-methionine complex, and one unidentified biotransformation product, but had no effect on the Pt-cysteine (or Pt-ornithine) complex. These effects of DDTC on protein-bound platinum and low-molecular-weight biotransformation products in plasma may contribute to the decrease in tetraplatin toxicity seen in DDTC-treated rats.

Renal, hepatic, cardiac and thymic acute toxicity afforded by bis(helenalinyl)malonate in BDF1 mice.

Bis(helenalinyl)malonate [BHM], a pharmacologically active sesquiterpene lactone potentially useful as an antineoplastic agent, proved to be less toxic than its parent compound, helenalin. Its LD50 in BDF1 mice, i.p. was more than twice that of helenalin. Its lower toxicity allowed a higher therapeutic dose (15 mg/kg/day vs. 8 mg/kg/day for helenalin) which, in turn, afforded a greater T/C% (261 vs. 161). When BHM was employed at its therapeutic dose of 15 mg/kg/day, no marked toxicity was evident after three daily doses. However, continuation of treatment at this level led to both kidney and liver toxicity as measured by clinical chemistry parameters. Histological lesions in the thymus and kidney were demonstrated within 48 h at 25 mg/kg as a single dose. Apparently the toxicity was delayed with BHM but accumulated over time. Transient cardiotoxicity occurred with the drug and the agent was suspected of causing intestinal blockage.

Reduction of tetrachloro(dl-trans)1,2-diaminocyclohexaneplatinum(IV) (tetraplatin) toxicity by the administration of diethyldithiocarbamate (DDTC), S-2(3-aminopropylamino)ethylphosphorothioic acid (WR-2721), or sodium selenite in the Fischer 344 rat.

Diethyldithiocarbamate (DDTC), S-2(3-aminopropylamino)ethylphosphorothioic acid (WR-2721), and sodium selenite have all been shown to effectively reduce cisplatin toxicity. As a result, we have investigated the efficacy of these compounds to reduce the toxicity associated with tetrachloro(dl-trans)1,2-diaminocyclohexaneplatinum(IV) (tetraplatin), a second-generation platinum compound recently approved for phase I/II clinical trials. The dose-limiting toxicities associated with tetraplatin (16.5 mg/kg) in the Fischer 344 male rat were nephrotoxicity, myelosuppression, and gastrointestinal toxicity. The nephrotoxicity in Fischer 344 rats was effectively reduced by treatment with either DDTC (750 mg/kg ip) 0.5 hr after tetraplatin or WR-2721 (200 mg/kg ip) 0.5 hr before tetraplatin as determined by blood urea nitrogen and creatinine values. Diarrhea was evident in 95% of the rats treated with tetraplatin alone while it was not evident in any of the DDTC- or WR-2721-protected rats. Only DDTC was moderately effective in preventing tetraplatin-induced decreases in platelet and lymphocyte counts. Histopathology confirmed DDTC protection of renal, intestinal, and lymphoid tissues and WR-2721 protection of renal and intestinal tissues. Sodium selenite was ineffective in reducing tetraplatin-induced damage when administered 4 hr before tetraplatin at doses of 0.5, 1.0, or 2.0 mg/kg. The results suggest that DDTC may allow for increased dosages of tetraplatin by ameliorating the toxic side effects of the drug. WR-2721 may also have some usefulness in tetraplatin therapy, but it does not reduce as wide a variety of toxic side effects as DDTC.

Role of thiol agents in protecting against the toxicity of helenalin in tumor-bearing mice.

Helanalin, a sesquiterpene lactone antineoplastic agent, is toxic at therapeutic doses in murine tumors. The toxicity has been assumed to be correlated with the binding of the drug to cellular thiol groups. Studies were undertaken to increase the intracellular level of GSH in the liver, kidney and other tissues to eliminate the toxicity of helenalin in vivo. Combination of helenalin 8 mg/kg/day i.p.) with L-cysteine (100 mg/kg/day), beta-mercaptoethanolamine (20 mg/kg/day), 18-beta-glycyrrhetinic acid (15 mg/kg/day), or 4,4'-diaminodiphenylsulfone (10 mg/kg/day) afforded improvement in survival of mice bearing P-388 lymphocytic leukemia. However, other thiol-elevating agents, anti-oxidants, intracellular buffering agents, and cardiac treatment drugs were not effective. Hydrocortisone, Cortef, treatment with helenalin afforded improvement in life expectancy. Reduced glutathione (GSH) and non-protein sulfhydryl (NPS) levels were not reduced in the liver, kidney, or circulating red blood cells (rbc) by helenalin treatment. After three days treatment of mice with helenalin, GSH levels were reduced and NPS levels elevated in P-388 tumor cells. Administration of L-cysteine, beta-mercaptoethanolamine, 4,4'-diaminodiphenylsulfone, or 18-beta-glycyrrhetinic acid alone caused no alteration in liver GSH but elevated NPS levels; P388 cell GSH and NPS levels were lowered. Combination of any of these agents, after three days, with helenalin afforded increases in P-388 cell GSH and NPS levels. This data would suggest that helenalin toxicity is not related to the lowering of GSH or NPS levels in critical tissues of mice.