Extensive Centrilobular Necrosis Research Articles

Acute Liver Failure Associated with Influenza A Virus Infection: an Autopsy Case Report

An 84-year-old man with chronic renal failure, anemia, and diabetes was admitted for hemodialysis initiation. His vital signs were stable until the eighteenth hospital day, before acquiring an influenza A virus infection. Three days later, he died of septic shock with severe liver impairment. His leukocyte count, prothrombin time (PT-INR), and liver enzyme levels such as aspartate transaminase and alanine aminotransferase, were significantly increased. Hypercytokinemia was also observed. Autopsy revealed bilateral diffuse pneumonia with neutrophil infiltration. The liver showed extensive centrilobular hepatocyte necrosis. Immunohistochemistry for influenza A nucleoprotein revealed positivity in the ciliated columnar epithelium of the bronchi and negativity in the trachea, lungs, and liver. Hypoxic hepatitis is characterized by an abrupt and massive increase in aminotransferase levels (＞ 20 times upper normal limit) due to anoxic centrilobular hepatocyte necrosis. The occurrence of hypoxic hepatitis requires a pre-existing, chronic condition, such as anemia, causing reduced oxygen supply to the liver, followed by an acute decrease in hepatic oxygen supply, such as septic shock. Therefore, this report suggests that hypoxic hepatitis can be an important causative factor for acute liver failure associated with influenza virus infection.

The liver in systemic disease: Sepsis and critical illness.

The liver in systemic disease: Sepsis and critical illness.

Diethylnitrosamine (DEN)-induced carcinogenic liver injury in mice.

The toxic properties of various nitrosamines in animals and humans are well established. The parenteral or oral administration of the smallest quantities of diethylnitrosamine (DEN) or dimethylnitrosamine (DMN) results in severe liver damage. Most prominent are intense neutrophilic infiltration, extensive centrilobular haemorrhagic necrosis, bile duct proliferation, fibrosis, and bridging necrosis that ends in hepatocarcinogenesis. Due to the robustness of the induced hepatic alterations, the application of DEN in rodents has become an attractive experimental model for studies aimed at understanding the pathogenetic alterations underlying the formation of liver cancer, which represents one of the most common malignancies in humans worldwide. However, several studies have shown that the hepatocarcinogenic effects of nitrosamines might vary with the genetic background of the animals, their sex, their age, and other factors that might impact the outcome of experimentation. We present general guidelines for working with DEN, and a detailed protocol that allows the establishment of highly reproducible liver cancer in mice. The outcome of liver injury after the application of DEN in mice, as estimated by the formation of cirrhosis and cancer, appears to be a suitable animal model for the analysis of some aspects and processes that promote the pathogenesis of hepatocellular carcinoma in humans.

HEPATOPROTECTIVE ACTIVITY OF ENHYDRA FLUCTUANS LOUR. AERIAL PARTS AGAINST CCL4 INDUCED HEPATOTOXICITY IN RATS

Enhydra fluctuans Lour. a n edible herbaceous vegetable plant and widely used in torpidity of liver and in nervous diseases. The different extracts (Pet - Ether extract, Chloroform extract and Ethanol extract) of Enhydra fluctuans aerial parts were studied for its hepatoprotective effect on CCl 4 induced hepatotoxic rats. The extracts were referred as PEEF, CEF and EEF respectively. In the toxicity study, all the extrac ts did not produce any mortality ev en at the highest dose (2000mg/kg) so 200mg/kg dose was taken as the tested dose. The extracts were found to decrease signifi cantly CCl 4 - induced elevation of SGOT, SGPT, bilirubin and total cholesterol at the dose of 200mg/kg body weight. But it increased HDL - cholesterol level and liver weight with respect to CCl 4 toxic rats. Histopathological profiles of CCl 4 - induced hepatotoxic liver revealed extensive centrilobular necrosis extending to other necrotic areas, ballooning degeneration with steatosis. The pr otective effect of PEEF, CEF and EEF (200 mg/kg, p.o.) were confirmed by histopathological examination of liver section of control, CCl 4 - induced and extracts treated groups of rats. Though all the extracts showed remarkable effect . EEF (200mg/kg, p.o.) tre ated rats exhibited a significant improvement of hepatocellular architecture over CCl 4 - induced group as evident from considerable reduction in necrosis and steatosis which is comparable with the standard drug Silymarin ( 25mg/kg, p.o.). K EYWORDS : Enhydra f luctuans Lour., Hepatoprotective activity, Carbon Tetra chloride, Biochemical studies, Histopathology.

Purinergic Receptor Antagonist A438079 Protects Against Acetaminophen-Induced Liver Injury by Inhibiting P450 Isoenzymes, Not by Inflammasome Activation

Acetaminophen (APAP) overdose is the most frequent cause of acute liver failure in the western world. Controversy exists regarding the hypothesis that the hepatocyte injury is amplified by a sterile inflammatory response, rather than being the result of intracellular mechanisms alone. A recent study suggested that the purinergic receptor antagonist A438079 protects against APAP-induced liver injury by preventing the activation of the Nalp3 inflammasome in Kupffer cells and thereby preventing inflammatory injury. To test the hypothesis that A438079 actually affects the intracellular signaling events in hepatocytes, C57Bl/6 mice were treated with APAP (300 mg/kg) and A438079 (80 mg/kg) or saline and GSH depletion, protein adduct formation, c-jun-N-terminal kinase (JNK) activation, oxidant stress, and liver cell necrosis were determined between 0 and 6 h after APAP administration. APAP caused rapid GSH depletion, extensive protein adduct formation in liver homogenates and in mitochondria, JNK phosphorylation and mitochondrial translocation of phospho-JNK within 2 h, oxidant stress, and extensive centrilobular necrosis at 6 h. A438079 significantly attenuated GSH depletion, which resulted in a 50% reduction of total liver and mitochondrial protein adducts and substantial reduction of JNK activation, mitochondrial P-JNK translocation, oxidant stress, and liver injury. The same results were obtained using primary mouse hepatocytes. A438079 did not directly affect JNK activation induced by tert-butyl hydroperoxide and GSH depletion. However, A438079 dose-dependently inhibited hepatic P450 enzyme activity. Thus, the protective effect of A438079 against APAP hepatotoxicity in vivo can be explained by its effect on metabolic activation and cell death pathways in hepatocytes without involvement of the Nalp3 inflammasome.

Mitogen-activated Protein Kinase Phosphatase (Mkp)-1 Protects Mice against Acetaminophen-induced Hepatic Injury

c-Jun N-terminal kinase (JNK) activation promotes hepatocyte death during acetaminophen overdose, a common cause of drug-induced liver failure. While mitogen-activated protein kinase (MAPK) phosphatase (Mkp)-1 is a critical negative regulator of JNK MAPK, little is known about the role of Mkp-1 during hepatotoxicity. In this study, we evaluated the role of Mkp-1 during acute acetaminophen toxicity. Mkp-1⁺/⁺ and Mkp-1⁻/⁻ mice were dosed ip with vehicle or acetaminophen at 300 mg/kg (for mechanistic studies) or 400 mg/kg (for survival studies). Tissues were collected 1-6 hr post 300 mg/kg dosing to assess glutathione levels, organ damage, and MAPK activation. Mkp-1⁻/⁻ mice exhibited more rapid plasma clearance of acetaminophen than did Mkp-1⁺/⁺ mice, indicated by a quicker decline of plasma acetaminophen level. Moreover, Mkp-1⁻/⁻ mice suffered more severe liver injury, indicated by higher plasma alanine transaminase activity and more extensive centrilobular apoptosis and necrosis. Hepatic JNK activity in Mkp-1⁻/⁻ mice was higher than in Mkp-1⁺/⁺ mice. Finally, Mkp-1⁻/⁻ mice displayed a lower overall survival rate and shorter median survival time after dosing with 400 mg/kg acetaminophen. The more severe phenotype exhibited by Mkp-1⁻/⁻ mice indicates that Mkp-1 plays a protective role during acute acetaminophen overdose, potentially through regulation of JNK.

Diagnostic Challenges in the Evaluation of Hepatic Grafts From Donors With HELLP Syndrome: Case Report and Review of the Literature

HELLP syndrome (hemolysis, elevated liver function tests, low platelets) is a rare complication of pregnancy that can result in severe complications such as hepatic infarction, subcapsular liver hematomas, and maternal brain death from cerebral hemorrhage. Recently, several investigators have described cases of successful transplantation using livers procured from donors who suffered brain death as a result of HELLP syndrome. However, this new class of marginal liver donors must be approached with caution. We report the case of a 28-year-old pregnant woman who suffered brain death due to HELLP syndrome and was subsequently evaluated for potential liver donation. Although her transaminitis and other liver function tests were markedly improving during the final days of her hospital course, her liver demonstrated segments of necrosis during attempted procurement, and the histology revealed extensive centrilobular necrosis. This case suggests that peak values of serum transaminases, as well as partial resolution of transaminitis, appear to have limited predictive ability in determining the suitability of the hepatic graft for transplantation. Thus, donors with HELLP syndrome should be approached with caution, even in the setting of laboratory values suggesting minimal or resolving hepatic injury. Furthermore, there should be an additional emphasis on obtaining and reviewing histology of the potential graft to determine its suitability for transplantation.

A Mouse Model of Severe Halothane Hepatitis Based on Human Risk Factors

Halothane (2-bromo-2-chloro-1,1,1-trifluoro-ethane) is an inhaled anesthetic that induces severe, idiosyncratic liver injury, i.e., "halothane hepatitis," in approximately 1 in 20,000 human patients. We used known human risk factors (female sex, adult age, and genetics) as well as probable risk factors (fasting and inflammatory stress) to develop a murine model with characteristics of human halothane hepatitis. Female and male BALB/cJ mice treated with halothane developed dose-dependent liver injury within 24 h; however, the liver injury was severe only in females. Livers had extensive centrilobular necrosis, inflammatory cell infiltrate, and steatosis. Fasting rendered mice more sensitive to halothane hepatotoxicity, and 8-week-old female mice were more sensitive than males of the same age or than younger (4-week-old) females. C57BL/6 mice were insensitive to halothane, suggesting a strong genetic predisposition. In halothane-treated females, plasma concentration of tumor necrosis factor-alpha was greater than in males, and neutrophils were recruited to liver more rapidly and to a greater extent. Anti-CD18 serum attenuated halothane-induced liver injury in female mice, suggesting that neutrophil migration, activation, or both are required for injury. Coexposure of halothane-treated male mice to lipopolysaccharide to induce modest inflammatory stress converted their mild hepatotoxic response to a pronounced, female-like response. This is the first animal model of an idiosyncratic adverse drug reaction that is based on human risk factors and produces reproducible, severe hepatitis from halothane exposure with lesions characteristic of human halothane hepatitis. Moreover, these results suggest that a more robust innate immune response underlies the predisposition of female mice to halothane hepatitis.

The crucial protective role of glutathione against tienilic acid hepatotoxicity in rats

To investigate the hepatotoxic potential of tienilic acid in vivo, we administered a single oral dose of tienilic acid to Sprague–Dawley rats and performed general clinicopathological examinations and hepatic gene expression analysis using Affymetrix microarrays. No change in the serum transaminases was noted at up to 1000 mg/kg, although slight elevation of the serum bile acid and bilirubin, and very mild hepatotoxic changes in morphology were observed. In contrast to the marginal clinicopathological changes, marked upregulation of the genes involved in glutathione biosynthesis [glutathione synthetase and glutamate-cysteine ligase (Gcl)], oxidative stress response [heme oxygenase-1 and NAD(P)H dehydrogenase quinone 1] and phase II drug metabolism (glutathione S-transferase and UDP glycosyltransferase 1A6) were noted after 3 or 6 h post-dosing. The hepatic reduced glutathione level decreased at 3–6 h, and then increased at 24 or 48 h, indicating that the upregulation of NF-E2-related factor 2 (Nrf2)-regulated gene and the late increase in hepatic glutathione are protective responses against the oxidative and/or electrophilic stresses caused by tienilic acid. In a subsequent experiment, tienilic acid in combination with l-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of Gcl caused marked elevation of serum alanine aminotransferase (ALT) with extensive centrilobular hepatocyte necrosis, whereas BSO alone showed no hepatotoxicity. The elevation of ALT by this combination was observed at the same dose levels of tienilic acid as the upregulation of the Nrf2-regulated genes by tienilic acid alone. In conclusion, these results suggest that the impairment of glutathione biosynthesis may play a critical role in the development of tienilic acid hepatotoxicity through extensive oxidative and/or electrophilic stresses.

Acute Fatal Acetaminophen Overdose Without Liver Necrosis

Two unusual cases of suicidal overdose of acetaminophen (paracetamol) without the usual extensive centrilobular necrosis of the liver are reported. Both cases were subjected to comprehensive drug screening by immunoassay, and a combination of gas chromatography with mass spectrometry, nitrogen detection, and electron capture detection. Acetaminophen was detected in both cases. No other drugs were detected in case #1, and only a small amount of olanzapine (<0.1 mg/L) was detected in case #2. No anatomical cause of death was identified in either case. If untreated, the normal outcome of a large acetaminophen overdose would be massive hepatic necrosis with delayed death and low blood and tissue acetaminophen concentrations. In contrast, particularly high postmortem acetaminophen concentrations were measured in both our cases with little hepatic tissue damage. For case #1, femoral blood acetaminophen 1280 mg/L, vitreous 878 mg/L, and liver 729 mg/kg; in case #2, cardiac blood 1220 mg/L, vitreous 779 mg/L, liver 3260 mg/kg, and gastric 11,500 mg/500 g. Acetaminophen was measured using high performance liquid chromatography with UV detection (254 nm) using 3-hydroxyacetanilide as the internal standard. The very high concentrations of acetaminophen is these cases but relatively little hepatic damage suggests an alternative, possibly cardiac, mechanism of death.

Mitochondrial alterations in livers of Sod1−/− mice fed alcohol

Chronic alcohol consumption induced liver injury in Cu,Zn-superoxide dismutase-deficient mice (Sod1−/−), with extensive centrilobular necrosis and inflammation and a reduction in hepatic ATP content. Mechanisms by which ethanol decreased ATP in these mice remain unclear. We investigated alterations in mitochondria of Sod1−/− mice produced by chronic ethanol treatment. These mitochondria had an increase in State 4 oxygen consumption with succinate and especially with glutamate plus malate compared to mitochondria from pair-fed Sod1−/− mice or mitochondria from wild-type mice fed dextrose or ethanol. This uncoupling was associated with a decrease in ADP/O and respiratory control ratios, a decline in mitochondrial membrane potential, enhanced mitochondrial permeability transition, and decreased aconitase activity. Total thiols and uncoupling protein 2 levels were elevated in the pair-fed Sod1−/− mitochondria, perhaps an adaptive response to oxidant stress. However, no such increases were found with the ethanol-fed Sod1−/− mitochondria, suggesting a failure to develop these adaptations. The mitochondria from the ethanol-fed Sod1−/− mice had elevated levels of cleaved Bax, Bak, Bcl-xl, and adenine nucleotide translocator. Immunoprecipitation studies revealed increased association of Bax and Bak with the adenine nucleotide translocator. ADP-ATP exchange was very low in the ethanol-fed Sod1−/− mitochondria. These results suggest that ethanol treatment of Sod1−/− mice produces uncoupling and a decline in Δψ, swelling, increased association of proapoptotic proteins involved in the permeability transition, and decreased adenine nucleotide translocator activity, which may be responsible for the decline in ATP levels and development of necrosis in this model of alcohol-induced liver injury.

Ca2+cytochemical changes of hepatotoxicity caused by halothane and sevoflurane in enzyme-induced hypoxic rats

To investigate the relation between hepatotoxicity of halothane and sevoflurane and altered hepatic calcium homeostasis in enzyme-induced hypoxic rats. Forty-eight rats were pretreated with phenobarbital and randomly divided into six groups (eight in each group) and exposed to O(2)/ N(2)/1.2 MAC anesthetics for 1 h: normal control (NC), 21% O(2)/79% N(2); hypoxic control (HC), 14% O(2)/86%N(2); normal sevoflurane (NS), 21% O(2)/ N(2)/1.2MAC sevoflurane; hypoxic sevoflurane (HS), 14% O(2)/ N(2)/1.2MAC sevoflurane; normal halothane (NH)21%O(2)/79%N(2)/1.2MAC halothane; hypoxic halothane (HH), 14% O(2)/N(2)/1.2MAC halothane. Liver specimens and blood were taken 24 h after exposure to calcium and determined by EDX microanalysis. The liver of all rats given halothane (14% O(2)) had extensive centrilobular necrosis and denaturation. Morphologic damage was accompanied with an increase in serum glutamic pyruvic transminase. In groups NH and HH, more calcium was precipitated in cytoplasm and mitochondria. These results suggest that halothane increases cytosolic Ca(2+) concentration in hepatocytes. Elevation in Ca(2+) concentration is implicated in the mechanism of halothane-induced hepatotoxicity. sevoflurane is less effective in affecting hepatic calcium homeostasis than halothane.

Alcohol-induced liver injury in mice lacking Cu, Zn-superoxide dismutase

Because alcoholic liver disease has been linked to oxidative stress, we investigated the effect of a compromised antioxidant defense system, Cu, Zn-superoxide dismutase (Sod1) deficiency, on alcohol-induced liver injury. C57BL/129SV wild-type (Sod1(+/+)) and Sod1 knockout (Sod1(-/-)) mice were fed dextrose or ethanol (10% of total calories) liquid diets for 3 weeks. Histologic evaluation of liver specimens of Sod1(-/-) mice fed ethanol showed the development of liver injury ranging from mild to extensive centrilobular necrosis and inflammation. Sod1(+/+) mice fed ethanol showed mild steatosis; both Sod1(+/+) and Sod1(-/-) mice fed the dextrose diet had normal histology. Alanine transaminase levels were significantly elevated only in Sod1(-/-) mice fed ethanol. Cytochrome P450 2E1 (CYP2e1) activity was elevated about 2-fold by ethanol in Sod1(+/+) and Sod1(-/-) mice. Ethanol consumption increased levels of protein carbonyls and lipid peroxidation aldehydic products in the liver of Sod1(-/-) mice. Hepatic adenosine triphosphate (ATP) content was reduced dramatically in Sod1(-/-) mice fed ethanol in association with a decrease in the mitochondrial reduced glutathione (GSH) level and activity of MnSOD. Immunohistochemical determination of 3-nitrotyrosine (3NT) residues in liver sections of the Sod1 knockout mice treated with ethanol showed a significant increase of 3NT staining in the centrilobular areas. In conclusion, a rather moderate ethanol consumption promoted oxidative stress in Sod1(-/-) mice, with increased formation of peroxynitrite, protein carbonyls, and lipid peroxidation and decreased mitochondrial GSH and MnSOD. We speculate that the increased oxidative stress causes mitochondrial damage and reduction of ATP content, leading to alcoholic liver injury. This model may be useful in further mechanistic studies on alcohol-induced liver injury.

A NO-releasing derivative of acetaminophen spares the liver by acting at several checkpoints in the Fas pathway.

NCX-701 is a nitric oxide (NO)-releasing acetaminophen (APAP) derivative. In the present study we demonstrated that NCX-701 is as effective as APAP in controlling body temperature in a rat model of endotoxin-induced fever. Liver toxicity is a major complication of APAP overdosing. To investigate whether NCX-701 is hepatotoxic, BALB/C mice were injected with 100 - 500 mg kg(-1) APAP or NCX-701 alone or in combination (i.e. 500 mg kg(-1) of both compounds). Our results demonstrated that although APAP caused a dose-dependent liver injury, NCX-701 was completely devoid of liver toxicity. At the dose of 500 mg kg(-1) APAP caused an approximately 40 fold increase of AST plasma levels and extensive centrilobular necrosis. APAP and NCX-701 share the same metabolic pathway as demonstrated by the time-course of APAP-glucuronide concentrations in plasma and liver. NCX-701 was safe in mice with pre-existing chronic liver disease. Indeed, while C57BL6 transgenic mice expressing the hepatitis B virus (HBV) at the age of 8 months were significantly more susceptible to liver damage induced by APAP (500 mg kg(-1)) than their congenic littermates, treating HBV-transgenic mice with NCX-701, 500 mg kg(-1), caused no damage. Co-administration of NCX-701 at the dose 500 mg kg(-1) to mice treated with APAP, 500 mg kg(-1), completely protected against liver damage induced by APAP. APAP, but not NCX-701, upregulated liver Fas and Fas Ligand mRNA expression in vivo. Incubating mouse hepatocytes with APAP, but not with NCX-701, increased cell surface Fas expression and sensitized hepatocytes to death induced by challenge with a Fas-agonistic antibody. Collectively, these observations suggest that APAP toxicity is Fas mediated and that NCX-701 spares the liver by acting at several checkpoints in the Fas pathway.

Modulation of macrophage functioning abrogates the acute hepatotoxicity of acetaminophen

Acetaminophen is a mild analgesic and antipyretic agent that is safe and effective when taken in therapeutic doses. Ingestion of overdoses, however, may lead to acute liver failure accompanied by centrilobular degeneration and necrosis. Although the toxicity of acetaminophen is generally thought to be caused by direct interaction of its reactive metabolites with cellular macromolecules, recent studies have suggested that nonparenchymal cells also may contribute to tissue injury indirectly through the release of cytotoxic mediators. We analyzed the potential role of hepatic macrophages in acetaminophen hepatotoxicity by examining the effects of modulating the activity of these cells on tissue injury. Treatment of male Long Evans Hooded rats with acetaminophen (800 mg/kg) was found to induce extensive centrilobular hepatic necrosis. Pretreatment of the rats with either dextran sulfate or gadolinium chloride, two inhibitors of hepatic macrophage functioning, completely blocked hepatic necrosis, as well as increases in serum transaminase levels induced by acetaminophen. Interestingly, treatment of rats with the macrophage activator, lipopolysaccharide (LPS), also reduced tissue injury induced by acetaminophen. To exclude the possibility that the effects of gadolinium chloride, dextran sulfate, or LPS were due to alterations in acetaminophen metabolism, we analyzed the effects of these agents on various pharmacokinetic properties of this analgesic. Dextran sulfate and gadolinium chloride had no effect on the half-life of a low dose of acetaminophen (20 mg/ kg), or on the activity of any of its individual pathways of metabolism, including the formation of acetaminophenmercapturic acid. LPS treatment of rats caused a general depression of acetaminophen metabolism involving all of the known pathways of metabolic clearance, resulting in a decrease in the blood half-life of the drug. However, the fraction of the dose converted to the toxic metabolite (NAPQI) was not different from that ob served in rats given acetaminophen alone. Collectively, these data indicate that the protection afforded the animals by pretreatment with macrophage modulators was not due to suppression of the formation of NAPQI and hence support the hypothesis that macrophages may contribute directly to acetaminophen hepatotoxicity by an independent mechanism.

Modulation of macrophage functioning abrogates the acute hepatotoxicity of acetaminophen

Acetaminophen is a mild analgesic and antipyretic agent that is safe and effective when taken in therapeutic doses. Ingestion of overdoses, however, may lead to acute liver failure accompanied by centrilobular degeneration and necrosis. Although the toxicity of acetaminophen is generally thought to be caused by direct interaction of its reactive metabolites with cellular macromolecules, recent studies have suggested that nonparenchymal cells also may contribute to tissue injury indirectly through the release of cytotoxic mediators. We analyzed the potential role of hepatic macrophages in acetaminophen hepatotoxicity by examining the effects of modulating the activity of these cells on tissue injury. Treatment of male Long Evans Hooded rats with acetaminophen (800 mg/kg) was found to induce extensive centrilobular hepatic necrosis. Pretreatment of the rats with either dextran sulfate or gadolinium chloride, two inhibitors of hepatic macrophage functioning, completely blocked hepatic necrosis, as well as increases in serum transaminase levels induced by acetaminophen. Interestingly, treatment of rats with the macrophage activator, lipopolysaccharide (LPS), also reduced tissue injury induced by acetaminophen. To exclude the possibility that the effects of gadolinium chloride, dextran sulfate, or LPS were due to alterations in acetaminophen metabolism, we analyzed the effects of these agents on various pharmacokinetic properties of this analgesic. Dextran sulfate and gadolinium chloride had no effect on the half-life of a low dose of acetaminophen (20 mg/kg), or on the activity of any of its individual pathways of metabolism, including the formation of acetaminophen-mercapturic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Fulminant Hepatic Failure Possibly Related to Ciprofloxacin

To report a case of hepatic failure in a patient who was receiving oral ciprofloxacin. Case reports, review articles, and relevant laboratory studies identified by MEDLINE. Data were abstracted from pertinent published sources by one author and reviewed by the remaining authors. A 66-year-old man was admitted for hip arthroplasty and developed fulminant hepatic failure during oral ciprofloxacin therapy. Ciprofloxacin was started on postoperative day 13 for treatment of a urinary tract infection. Over the next three days he became confused and hypoglycemic. His prothrombin time increased to greater than 90 s. Serum aspartate aminotransferase and alanine aminotransferase concentrations were markedly elevated. The patient died on postoperative day 20. Postmortem examination of the liver revealed extensive centrilobular necrosis. A skin biopsy was consistent with a drug reaction. It is unknown whether the patient had received a quinolone compound in the past or had a history of exposure to hepatotoxins. It cannot be concluded that ciprofloxacin directly caused hepatic failure in this patient. It is possible that the drug evoked a hypersensitivity reaction or exacerbated a preexisting hepatotoxicity. A detailed patient history and evaluation of hepatic function should be obtained prior to initiating ciprofloxacin therapy. A nonquinolone antimicrobial may be a safer alternative for patients with hepatic dysfunction.

23Na- and 31P-NMR studies of perfused mouse liver during nitrogen hypoxia.

The effects of nitrogen hypoxia on isolated perfused mouse livers from fed mice were studied at 37 degrees C using 23Na and 31P nuclear magnetic resonance (NMR) spectroscopy. The paramagnetic shift reagent, dysprosium-triethylenetetraminehexaacetic acid, was used to distinguish intracellular from extracellular sodium. The area of the intracellular sodium resonance remained relatively constant over the first 30 min of hypoxia and then increased by a factor of approximately 2 relative to controls over the next 30 min. High-energy phosphate metabolites were measured using 31P-NMR. The beta-ATP resonance decreased to zero, and the intracellular pH decreased from 7.3 to 6.9 during 60 min of hypoxia. Liver enzyme activity in the effluent exiting the liver increased in direct proportion to the length of hypoxia up to 56 min. The sodium, ATP, and enzyme changes during hypoxia were correlated with histological and electron-microscopic findings. The morphology of liver specimens exposed to 30 min of hypoxia was close to normal, whereas extensive centrilobular and midlobular necrosis was seen in specimens subjected to 60 and 90 min of hypoxia. The effect of 30 min of reoxygenation after 15, 30, 45, 60, and 90 min of hypoxia was also studied. The level of beta-ATP recovery depended on the duration of hypoxia. For 60 min of hypoxia followed by reoxygenation, beta-ATP recovered to only 20% of control values. The morphology of hypoxic livers after 30 min of reoxygenation was similar to livers subjected to hypoxia alone.

Hepatic dysfunction accompanying acute cocaine intoxication

We identified 39 patients with acute cocaine intoxication and rhabdomyolysis over an 8-year period. Twenty-three of the patients (59%) demonstrated biochemical evidence for hepatic dysfunction. Sixteen of these patients had severe liver injury as defined by an alanine aminotransferase (ALT) of greater than 400 U/l (group A). Seven had an ALT between 36-399 U/l (group B) and 16 showed no evidence of liver injury (group C). In contrast to those with normal ALT, the clinical course of the group A patients was more often accompanied by profound hypotension (44 vs. 0%, p less than 0.025), disseminated intravascular coagulation (50 vs. 0%, p less than 0.005), hyperpyrexia (75 vs. 25%, p less than 0.025) and acute renal failure (81 vs. 0%, p less than 0.001). Seven of the group A patients expired (44%). Histologic examination of liver tissue obtained from post-mortem samples demonstrated extensive centrilobular and midzonal necrosis in three cases and panlobular necrosis in two others. A mild lymphocytic infiltrate with bile duct proliferation was present in each specimen. We conclude that cocaine intoxication can be accompanied by liver dysfunction which is most likely multifactorial; the presence of severe dysfunction identifies a patient with potentially significant morbidity and mortality.

Biochemical and functional effects of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) on the heart of female rats

Biochemical, functional and morphologic effects of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) on the hearts of female rats were examined. Six days after the treatment of rats with TCDD, the blood pressures and resting heart rates were significantly less than in control animals. Treated animals were also less responsive to the effects of the β-1 agonist, (−)isoproterenol. No histopathologic changes were observed in the heart although extensive centrilobular necrosis occurred in the liver after TCDD administration. Serum levels of thyroxine were 66% less than in control animals. Marked lipid peroxidation was produced in the liver with small but significant increases occurring in the heart. TCDD administration had no effect on catalase activity in the heart, but produced a 20% decrease in superoxide dismutase activity relative to control animals. The effects of TCDD on cardiac function do not appear to be due to a direct action of the xenobiotic on the heart but possibly to a down-regulation of β-receptors in the heart as a result of the hypothyroid state.