Drug-induced liver injury secondary to increased levonorgestrel exposure in a patient taking ritonavir

We report the first published case of a drug induced liver injury (DILI) presumed secondary to a drug-drug interaction between ritonavir and levonorgestrel progestogen-only emergency contraception (POEC). Our patient is a 25-year-old female living with human immunodeficiency virus (HIV), taking antiretroviral therapy (ART) containing tenofovir alafenamide/emtricitabine and darunavir/ritonavir. She was found to have elevated transaminases at a routine clinic appointment consistent with hepatocellular DILI. Further investigation found the most likely cause of this was a drug-drug interaction (DDI) between the ritonavir component of her ART and recent use of levonorgestrel POEC 3 days earlier. Evidence suggests that ritonavir increases levonorgestrel exposure, yet our patient received double the usual dose as per dispensing guidance at the time. We review the pharmacokinetics of ritonavir-levonorgestrel DDIs and highlight the need for consistent guidelines on this topic.

Increased BMI and Type 2 diabetes are the main predictors of NAFLD and advanced fibrosis in liver biopsies of patients with HIV mono-infection

BACKGROUND

Liver disease is an important cause of morbidity and mortality in people living with HIV (PLWH), of which non-alcoholic fatty liver disease (NAFLD) is an increasingly recognised cause. There is limited data investigating NAFLD in HIV mono-infection and histologically defined disease. We aimed to identify who is at risk of fibrosis, NAFLD and NASH among PLWH, and explore the diagnostic accuracy of non-invasive markers of fibrosis.

METHODS

Retrospective cross-sectional international multicentre study including patients with HIV mono-infection, without chronic viral hepatitis or other known causes of chronic liver disease, who underwent liver biopsy for abnormal liver biochemistry and/or clinical suspicion of liver fibrosis.

RESULTS

One hundred and sixteen patients from 5 centres were included. Sixty-three (54%) had NAFLD, of whom 57 (92%) had NASH. Overall, 36 (31%) had advanced fibrosis (≥F3) and 3 (3%) cirrhosis. Of the 53 cases without NAFLD, 15 (28%) had advanced fibrosis. Collagen proportionate area (CPA) was similar between cases with and without NAFLD (3% vs 2%). Body mass index (BMI) was independently associated with NAFLD (aOR 1.2 95% CI 1.08-1.34), and type 2 diabetes was independently associated with advanced fibrosis (aOR 3.42 95% CI 1.00-11.71)). The area under the curve for advanced fibrosis was 0.65 and 0.66 for both NAFLD Fibrosis Score (NFS) and FIB-4. Cut-off values of -1.455 (NFS) and 1.3 (FIB-4) have negative predictive values of 0.80 and 0.82, respectively.

CONCLUSION

Advanced fibrosis is strongly associated with type 2 diabetes in PLWH. Serological markers require further optimisation.

Spleen stiffness measurements using point shear wave elastography detects noncirrhotic portal hypertension in human immunodeficiency virus

To assess the utility of spleen stiffness as a diagnostic tool in individuals with human immunodeficiency virus (HIV) and non-cirrhotic portal hypertension (NCPH).The Philips EPIQ7, a new point shearwave elastography (pSWE) technique, was used to assess liver and spleen stiffness in 3 patient groups. Group 1: HIV and NCPH (n = 11); Group 2: HIV with past didanosine (ddI) exposure without known liver disease or NCPH (n = 5); Group 3: HIV without known liver disease or ddI exposure (n = 9).Groups were matched for age, HIV chronicity, and antiretroviral treatment (including cumulative ddI exposure in Groups 1 and 2). Differences in liver and spleen stiffness (in kPa) between groups were analyzed using the Mann-Whiney U test.Liver and spleen stiffness were both significantly higher in NCPH versus ddI-exposed (P = .019 and P = .006) and ddI-unexposed controls (P = .038 and P < .001). Spleen stiffness was more effective than liver stiffness at predicting NCPH, area under receiver operating characteristic (AUROC) 0.812 versus 0.948. Combining the 2 variables improved the diagnostic performance, AUROC 0.961. The optimal cut-off for predicting NCPH using splenic stiffness was 25.4 kPa, with sensitivity 91%, specificity 93%, positive predictive value (PPV) 91%, negative predictive value (NPV) 93%, positive likelihood ratio 12.73, negative likelihood ratio 0.10. Spleen and liver stiffness scores were strongly correlated (P = .0004, 95% confidence interval [CI] 18, 59).Elevated spleen stiffness is observed in HIV with NCPH and can be quantified easily using pSWE with high diagnostic accuracy. Novel strategies such as pSWE for longitudinal monitoring of patients with HIV and NCPH should be considered.

Magnetic Resonance Imaging of Cerebral Small Vessel Disease in Men Living with HIV and HIV-Negative Men Aged 50 and Above

We assessed whether HIV status was associated with white matter hyperintensities (WMH), a neuroimaging correlate of cerebral small vessel disease (CSVD), in men aged ≥50 years. A cross-sectional substudy was nested within a larger cohort study. Virologically suppressed men living with HIV (MLWH) and demographically matched HIV-negative men aged ≥50 underwent magnetic resonance imaging (MRI) at 3 Tesla. Sequences included volumetric three-dimensional (3D) T1-weighted, fluid-attenuated inversion recovery and pseudocontinuous arterial spin labeling. Regional segmentation by automated image processing algorithms was used to extract WMH volume (WMHV) and resting cerebral blood flow (CBF). The association between HIV status and WMHV as a proportion of intracranial volume (ICV; log-transformed) was estimated using a multivariable linear regression model. Thirty-eight MLWH [median age 59 years (interquartile range, IQR 55-64)] and 37 HIV-negative [median 58 years (54-63)] men were analyzed. MLWH had median CD4⁺ count 570 (470-700) cells/μL and a median time since diagnosis of 20 (14-24) years. Framingham 10-year risk of cardiovascular disease was 6.5% in MLWH and 7.4% in controls. Two (5%) MLWH reported a history of stroke or transient ischemic attack and five (13%) reported coronary heart disease compared with none of the controls. The total WMHV in MLWH was 1,696 μL (IQR 1,229-3,268 μL) or 0.10% of ICV compared with 1,627 μL (IQR 1,032-3,077 μL), also 0.10% of ICV in the HIV-negative group (p = .43). In the multivariable model, WMHV/ICV was not associated with HIV status (p = .86). There was an age-dependent decline in cortical CBF [-3.9 mL/100 mL/min per decade of life (95% confidence interval 1.1-6.7 mL)] but no association between CBF and HIV status (p > .2 in all brain regions analyzed). In conclusion, we found no quantitative MRI evidence of an increased burden of CSVD in MLWH aged 50 years and older.

Differences in the variability of cerebral proton magnetic resonance spectroscopy (1H-MRS) measurements within three HIV-infected cohorts

INTRODUCTION

Cerebral functional impairment remains prevalent in effectively treated HIV-infected subjects. As the results of formal cognitive testing are highly variable, surrogate markers to accurately measure cerebral function parameters are needed. Such markers include measurement of cerebral metabolite ratios (CMR) using proton magnetic resonance spectroscopy (1H-MRS). However, data on the inter-subject variability of CMR are sparse. Our aim was to assess inter-subject variability in CMRs within three different HIV-infected cohorts.

METHODS

Cerebral 1H-MRS was performed using a Phillips Achieva™ 1.5 Tesla magnetic resonance scanner in HIV-infected subjects as follows: 12 subjects before (group 1) and after intensification of antiretroviral therapy with maraviroc (group 2) and 13 subjects with acute viral hepatitis C (HCV) co-infection (group 3). The coefficients of variation (CV) for CMRs in each group were determined and compared using non-parametric tests to determine whether the inter-subject variability differed significantly. All baseline characteristics between the groups were similar.

RESULTS

Overall CVs for all CMRs in groups 1, 2 and 3 were 32.3%, 33.2% and 23.4%, respectively (group 1 vs. 2, p=0.863; group 1 vs. 3, p=0.076). On testing for differences in variability between individual CMRs, two metabolites in the right basal ganglia (RBG) had statistically significantly different CVs when comparing group 1 with group 3: N-acetyl aspartate/creatine (NAA/Cr), p=0.029 and myo-Inositol/creatine (mI/Cr), p=0.016.

CONCLUSION

The variability of 1H MRS-measurable CMRs in HIV-infected individuals was lower in those with acute HCV co-infection (group 3).We can conclude that the use of these CMRs in 1H MRS imaging in patients with HIV/acute HCV co-infection is more reliable to assess cerebral function than in patients with HIV infection alone. This has implications for future sample size estimations.

HIV-1 CNS in vitro infectivity models based on clinical CSF samples

BACKGROUND

The concentration of antiretrovirals in CSF is often utilized as a surrogate for CNS drug exposure. This measurement does not consider pharmacodynamic or combinative effects of ART. We have developed a novel endpoint measurement to assess antiretroviral activity of CSF from subjects on ART.

METHODS

CSF samples were obtained from patients receiving tenofovir/emtricitabine (245/200 mg once daily) with either rilpivirine (25 mg once daily) or lopinavir/ritonavir/maraviroc (400/100/150 mg twice daily) and HIV-uninfected controls. Antiviral activity of ART-containing CSF was assessed in cell cultures using PBMCs and neuro-derived glial (U87) and astrocyte (373) cell lines. Infectivity model half-maximal inhibitory concentration (IMIC50) values were calculated and expressed as -log2IMIC50. Results were correlated with CSF antiretroviral concentrations.

RESULTS

Compared with controls, CSF from both ART studies demonstrated in vitro antiretroviral activity in all models. CSF antiretroviral activity of patients on lopinavir/ritonavir/maraviroc was significantly greater than that of patients on rilpivirine [-log2IMIC50 (95% CI) 4.82 (4.74-4.89) versus 3.43 (3.33-3.54) in PBMCs, 3.06 (2.98-3.15) versus 2.56 (2.46-2.65) in U87 cells and 6.00 (6.11-5.88) versus 4.90 (5.09-4.72) in 373 cells, respectively]. Positive correlations were observed for individual CSF antiretroviral activity in different cellular models with CSF concentrations of rilpivirine (P = 0.040 in 373 cells) and lopinavir (P = 0.048 in 373 cells), but not maraviroc.

CONCLUSIONS

Antiviral activity of CSF from patients on ART was successfully calculated and was greater with a regimen containing four active drugs compared with three active drugs. The use of neuro-derived cell lines alongside PBMCs to assess the effect of ART on CSF may act as a useful future clinical research tool.

Drug hypersensitivity in clonal mast cell disorders: ENDA/EAACI position paper

Mastocytosis is a clonal disorder characterized by the proliferation and accumulation of mast cells (MC) in different tissues, with a preferential localization in skin and bone marrow (BM). The excess of MC in mastocytosis as well as the increased releasability of MC may lead to a higher frequency and severity of immediate hypersensitivity reactions. Mastocytosis in adults is associated with a history of anaphylaxis in 22-49%. Fatal anaphylaxis has been described particularly following hymenoptera stings, but also occasionally after the intake of drugs such as nonsteroidal anti-inflammatory drugs, opioids and drugs in the perioperative setting. However, data on the frequency of drug hypersensitivity in mastocytosis and vice versa are scarce and evidence for an association appears to be limited. Nevertheless, clonal MC disorders should be ruled out in cases of severe anaphylaxis: basal serum tryptase determination, physical examination for cutaneous mastocytosis lesions, and clinical characteristics of anaphylactic reaction might be useful for differential diagnosis. In this position paper, the ENDA group performed a literature search on immediate drug hypersensitivity reactions in clonal MC disorders using MEDLINE, EMBASE, and Cochrane Library, reviewed and evaluated the literature in five languages using the GRADE system for quality of evidence and strength of recommendation.

Cerebral function in perinatally HIV-infected young adults and their HIV-uninfected sibling controls

BACKGROUND

Perinatally acquired HIV-infected (PaHIV) young adults undergo neurodevelopment in the presence of HIV infection and antiretroviral therapy, which may lead to neurocognitive (NC) impairment. Knowledge of NC function in this group is sparse and control data lacking. We compared cerebral function in young adults with PaHIV infection to aged matched HIV negative family controls.

METHODS

16-25-year-old PaHIV young adults (Group 1, n = 33) and HIV-uninfected family controls (Group 2, n = 14) were recruited. Cerebral function was evaluated by: a computerized battery assessing NC function (CogState(TM)), International HIV Dementia Scale (IHDS) and the prospective and retrospective memory questionnaire (PRMQ). Eight cases and four controls also underwent (1)H cerebral magnetic resonance spectroscopy ((1)H-MRS) scanning measuring basal ganglia (BG) metabolites. Cases and controls were compared.

RESULTS

Group 1 mean (SD) CD4 count; 444 (319) cells/μl, plasma HIV viral load < 50 in 55%. There were no statistically significant differences between study groups in NC function or IHDS results (P>0.27 all observations). PRMQ scores were significantly higher (42 versus 35, P = 0.02) and MRS BG inflammatory-metabolites (choline- and myo-inositol- to creatine ratios) were significantly greater in Group 1 versus Group 2 (0.83 versus 0.63, P = 0.02 and 3.43 versus 3.03.P = 0.09 respectively). No significant association between PRMQ score and MRS metabolites was observed (P = 0.89).

CONCLUSION

Statistically significant differences in cerebral function parameters were observed in PaHIV young adults compared to a well-matched control population. The cognitive deficit observed, in memory, rather than fine motor function, differs from the cerebral impairment often reported in HIV-infected adults.

Effects of different antiretroviral agents on cerebral function in HIV-infected individuals

Since the advent of effective antiretroviral therapy, the incidence of severe HIV-associated brain disease has declined dramatically; however, more subtle forms of cerebral impairment, known as HIV-associated neurocognitive disorders, are becoming increasingly recognized. Some of the risk factors for this impairment are well described and include nadir CD4+ cell count. However, the effects of different antiretroviral agents on cerebral function are only beginning to be unraveled. Overall, there are clear beneficial effects on neurocognitive function from antiretroviral therapy. Recent data suggest that some antiretroviral agents have more potent effects on improving cerebral function, whereas other antiretroviral agents may even be associated with direct cerebral toxicities.

Antiretroviral therapy CNS penetration and HIV-1-associated CNS disease

OBJECTIVE

The impact of different antiretroviral agents on the risk of developing or surviving CNS disease remains unknown. The aim of this study was to investigate whether using antiretroviral regimens with higher CNS penetration effectiveness (CPE) scores was associated with reduced incidence of CNS disease and improved survival in the UK Collaborative HIV Cohort (CHIC) Study.

METHODS

Adults without previous CNS disease, who commenced combination antiretroviral therapy (cART) between 1996 and 2008, were included (n = 22,356). Initial and most recent cART CPE scores were calculated. CNS diseases were HIV encephalopathy (HIVe), progressive multifocal leukoencephalopathy (PML), cerebral toxoplasmosis (TOXO), and cryptococcal meningitis (CRYPTO). Incidence rates and overall survival were stratified by CPE score. A multivariable Poisson regression model was used to identify independent associations.

RESULTS

The median (interquartile range) CPE score for initial cART regimen increased from 7 (5-8) in 1996-1997 to 9 (8-10) in 2000-2001 and subsequently declined to 6 (7-8) in 2006-2008. Differences in gender, HIV acquisition risk group, and ethnicity existed between CPE score strata. A total of 251 subjects were diagnosed with a CNS disease (HIVe 80; TOXO 59; CRYPTO 56; PML 54). CNS diseases occurred more frequently in subjects prescribed regimens with CPE scores ≤ 4, and less frequently in those with scores ≥ 10; however, these differences were nonsignificant. Initial and most recent cART CPE scores ≤ 4 were independently associated with increased risk of death.

CONCLUSION

Clinical status at time of commencing cART influences antiretroviral selection and CPE score. This information should be considered when utilizing CPE scores for retrospective analyses.

Pharmacokinetic and safety profile of raltegravir and ribavirin, when dosed separately and together, in healthy volunteers

BACKGROUND

Treatment of chronic hepatitis C virus (HCV) infection in HIV-1-co-infected individuals remains challenging due to numerous factors, including drug-drug interactions. The aim of this study was to assess the safety and pharmacokinetic (PK) profile of raltegravir and ribavirin when dosed separately and together.

METHODS

Fourteen healthy volunteers [mean (standard deviation) age 35 (10) years, 71% male] entered this phase 1 PK study and received single-dose ribavirin (800 mg) on day 1 (phase 1). Following a washout period, subjects received raltegravir (400 mg twice daily) on days 15-19 (phase 2) and single-dose ribavirin (800 mg) with raltegravir (400 mg) on day 20 (phase 3). Intensive PK sampling was undertaken on days 1, 19 and 20 and differences in geometric mean ratios (GMRs) for PK parameters between study periods were assessed.

RESULTS

No statistically significant differences in PK parameters were observed for raltegravir between phases 2 and 3. A statistically significant decrease in maximum plasma concentration (C(max)) and an increase in time to maximum plasma concentration (T(max)) were observed for ribavirin in phase 3 compared with phase 1 [GMR (95% confidence interval) 0.79 (0.62-1.00) and 1.39 (1.08-1.78), respectively], whereas no significant differences in other ribavirin PK parameters were observed between study phases. No clinically significant safety concerns were reported.

CONCLUSIONS

The PK profile of ribavirin is altered when administered with raltegravir (reduced C(max) and increased T(max)), with no safety concerns identified. This is unlikely to be of clinical significance or have an impact on the antiviral effects of ribavirin in HIV-1- and HCV-co-infected subjects.

The British HIV Association national audit on the management of subjects co-infected with HIV and hepatitis B/C

The aim of this work was to survey current service provision and adherence to the British HIV Association (BHIVA) guidelines for the management of HIV and hepatitis B/C co-infected patients in the UK. Sites were invited to complete a survey of local care arrangements for co-infected patients. A case-note audit of all co-infected attendees during a six-month period in 2009 was performed. Data including demographics, clinical parameters, hepatitis disease status, antiretroviral and hepatitis B/C therapy were collected. Using BHIVA guidelines as audit standards, the proportion of sites and subjects meeting each standard was calculated. One-hundred and forty sites (75%) responded and data from 973 eligible co-infected patients were submitted. Approximately a third of sites reported not re-checking hepatitis serology or vaccination titres annually. Of all co-infected patients, 122 (13%) were neither vaccinated nor immune to hepatitis A and 26 (5%) of patients with hepatitis C were neither vaccinated nor naturally immune to hepatitis B. Of HBsAg-positive subjects, 25 (6%) were receiving lamivudine as the sole drug with antihepatitis B activity. In the UK, the management of HIV and hepatitis B/C co-infection remains highly variable. Optimizing the care of this high-risk patient group is a priority.

HIV-associated central nervous system diseases in the recent combination antiretroviral therapy era

BACKGROUND AND PURPOSE

Data describing the incidence and survival of HIV-related central nervous system diseases (CNS-D) in recent years are sparse.

METHODS

Between 1996 and 2007, adult subjects without previous CNS-D within a large UK cohort were included (n=30,954). CNS-D were HIV encephalopathy (HIVe), progressive multifocal leucoencephalopathy (PML), cerebral toxoplasmosis (TOXO) and cryptococcal meningitis (CRYP). Associations between demographic, clinical and laboratory parameters with incidence and survival of CNS-D were evaluated using Poisson regression analysis and Kaplan-Meier techniques.

RESULTS

Six hundred and thirteen new CNS-D occurred in 574 subjects (HIVe:187, PML:113, TOXO:184, CRYP:129). Incidence of all CNS-D declined from 13.1 per 1000 PY in 1996/1997 to 1.0 per 1000 PY in 2006/2007 (P=0.0001). Current CD4+ cell count below 200 cells/ul and plasma HIV RNA above 100,000 copies/ml were independently associated with the development of CNS-D. Calendar year 1996/1997, older age, prior AIDS diagnosis and PML diagnosis were significantly associated with shorter survival.

CONCLUSIONS

An ongoing decline in the incidence of CNS-D has been observed in very recent years. Mortality following such a diagnosis remains high.

Increased level of arginase activity correlates with disease severity in HIV-seropositive patients

Infection with human immunodeficiency virus (HIV) results in a chronic infection that progressively impairs the immune system. Although depletion of CD4(+) T cells is frequently used to explain immunosuppression, chronicity of infection and progressive loss of CD4(+) T cells are not sufficient to fully account for immune dysregulation. Arginase-induced l-arginine deprivation is emerging as a key mechanism for the down-regulation of immune responses. Here, we hypothesized that the level of arginase activity increases with disease severity in HIV-seropositive patients. We determined the levels of arginase activity in peripheral blood mononuclear cells from HIV-seropositive patients and uninfected control participants. Our results show that peripheral blood mononuclear cells from HIV-seropositive patients with low CD4(+) T cell counts expressed statistically significantly higher levels of arginase activity, compared with patients with high CD4(+) T cell counts or uninfected control participants. Furthermore, we found a statistically significant correlation between high level of arginase activity and high viral load in HIV-seropositive patients.

Does acute hepatitis C infection affect the central nervous system in HIV-1 infected individuals?

Central nervous system (CNS) manifestations of chronic hepatitis C virus (HCV) and chronic human immune deficiency virus-1 (HIV-1) infections have been reported, but the impact of acute HCV infection on the CNS is unknown. A total of 10 individuals with chronic stable HIV-1 with documented acute HCV (HCV-RNA polymerase chain reaction positive and HCV antibody negative, group 1) underwent cerebral proton magnetic resonance spectroscopy (MRS) using acquisition parameters to quantify myo-inositol/creatine (mI/Cr) ratio in the right basal ganglia (RBG). Two matched control groups also underwent MRS; group 2: ten with chronic HIV-1 and no evidence of HCV, and group 3: ten with no evidence of HIV or HCV. Subjects also underwent computerized neurocognitive assessments (CogState). RBG mI/Cr ratio in group 1 (acute HCV in a background of HIV) was significantly lower than that in groups 2 and 3 [2.90 (+/-0.7) vs 3.34 (+/-0.4) and 3.43 (+/-0.4), mean (SD) for group 1 vs 2 and 3 respectively, P = 0.049], with 50% of subjects in group 1 having a mI/Cr ratio below the lowest observed ratio in either of the other groups. On neurocognitive testing, significant defects in the monitoring domain were observed in group-1, compared with matched controls (P = 0.021). Acute HCV in HIV-1 infected subjects is associated with CNS involvement. Clinicians should be vigilant of early CNS involvement when assessing subjects with acute HCV.

Clinical implications of antiretroviral pharmacokinetics and pharmacodynamics in the CNS

The prevalence of HIV-associated brain disease remains high in the combination antiretroviral era. Factors associated with the development of HIV-associated neurocognitive impairment remain poorly understood. The selection of an antiretroviral regimen that can successfully penetrate the CNS compartment and control cerebrospinal fluid HIV replication may prove a crucial strategy in preventing the emergence and progression of HIV-associated neurocognitive impairment. Different antiretroviral agents and drug classes vary in their ability to penetrate the CNS. In this review, data on the CNS penetration of antiretrovirals are evaluated, including the clinical studies examining their relevance. Prospective studies examining the effect of different treatment strategies on CNS clinical outcomes are needed.

Does chronic stress lead to increased rates of recurrences of genital herpes - a review of the psychoneuroimmunological evidence?

Summary:

It is a commonly expressed expert view that stress is associated with frequent recurrences of genital herpes (GH) but the evidence for this is poor and it is often asserted that stress is the result of GH rather than any other cause. We have reviewed the recent literature on this topic, restricting evidence to only prospective studies. We have further combined and integrated this evidence with both human and animal work in the psychoneuroimmunological field to come up with suggestive evidence that recurrence rates of GH are indeed associated with antecedent chronic stress/depression, whatever might be the cause. We further discuss the psychoneuroimmunological underpinning of the systemic features of the recurrent GH prodrome. Recommendations about holistic management of recurrent GH that include both pharmacological and psychological therapies are given.

Cocaine, ethanol, and cocaethylene cardiotoxity in an animal model of cocaine and ethanol abuse

OBJECTIVES

Simultaneous abuse of cocaine and ethanol affects 12 million Americans annually. In combination, these substances are substantially more toxic than either drug alone. Their combined cardiac toxicity may be due to independent effects of each drug; however, they may also be due to cocaethylene (CE), a cocaine metabolite formed only in the presence of ethanol. The purpose of this study was to delineate the role of CE in the combined cardiotoxicity of cocaine and ethanol in a model simulating their abuse.

METHODS

Twenty-three dogs were randomized to receive either 1) three intravenous (IV) boluses of cocaine 7.5 mg/kg with ethanol (1 g/kg) as an IV infusion (C+E, n = 8), 2) three cocaine boluses only (C, n = 6), 3) ethanol infusion only (E, n = 5), or 4) placebo boluses and infusion (n = 4). Hemodynamic measurements, electrocardiograms, and serum drug concentrations were obtained at baseline, and then at fixed time intervals after each drug was administered.

RESULTS

Two of eight dogs in the C+E group experienced cardiovascular collapse. The most dramatic hemodynamic changes occurred after each cocaine bolus in the C+E and C only groups; however, persistent hemodynamic changes occurred in the C+E group. Peak CE levels were associated with a 45% (SD +/- 22%, 95% CI = 22% to 69%) decrease in cardiac output (p < 0.05), a 56% (SD +/- 23%, 95% CI = 32% to 80%) decrease in dP/dt(max) (p <.006), and a 23% (SD +/- 15%, 95% CI = 7% to 49%) decrease in SVO(2) (p < 0.025). Ventricular arrhythmias were primarily observed in the C+E group, in which four of eight dogs experienced ventricular tachycardia.

CONCLUSIONS

Cocaine and ethanol in combination were more toxic than either substance alone. Co-administration resulted in prolonged cardiac toxicity and was dysrhythmogenic. Peak serum cocaethylene concentrations were associated with prolonged myocardial depression.

Etiologic factors in progression of carotid stenosis: a 10-year study in 905 patients

PURPOSE

The purpose of this study was to determine the etiologic factors in the progression of carotid stenosis.

METHODS

We performed prospective serial duplex scan surveillance of 1470 carotid arteries in 905 asymptomatic patients during a 10-year period, with an average follow-up interval of 29 months and an average of 3.0 scans per carotid artery. Vascular laboratory and hospital records were used to collect risk factor information. The data were analyzed with proportional hazards modeling.

RESULTS

We examined several demographic, clinical, and laboratory risk factors that were chosen because of their potential relevance to atherosclerotic disease. These factors were analyzed with univariate proportional hazards modeling, in which time to progression of stenosis was the outcome variable. The six significant predictors (P <.05) were age, sex, systolic pressure, pulse pressure (systolic pressure - diastolic pressure), total cholesterol, and high-density lipoprotein (HDL). All, except HDL, were positive predictors of time to disease progression. With multivariate modeling, only pulse pressure and HDL remained as significant independent predictors of stenosis progression. The risk ratio for a 10-mm Hg rise in pulse pressure was 1.12, and the risk ratio for a 10-mg/dL decrease in HDL was 1.20.

CONCLUSION

In this large cohort of patients who were followed prospectively for carotid stenosis, pulse pressure and HDL were found to be the key risk factors for carotid stenosis progression. The fact that pulse pressure superseded systolic pressure in multivariate modeling may shed light on the biology of carotid plaque progression. Further, our identification of these modifiable risk factors may help in the design of therapeutic trials for the prevention of progression of carotid atherosclerosis.

Cocaine-induced wide complex dysrhythmia

Cocaine is a local anesthetic with the potential to induce dysrhythmia due to direct myocardial sodium channel antagonism similar to class I antidysrhythmic drugs. The hallmark of myocardial sodium channel poisoning is wide complex dysrhythmia, and the current accepted treatment is intravenous bicarbonate. Wide complex dysrhythmio due to cocaine in the absence of myocardial infarction is rare, and optimum management is undefined. We report three cases of acute cocaine intoxicating during which patients developed wide complex dysrhythmia consistent with sodium channel poisoning. In one case, wide complex tachycardia resolved without direct treatment. In the other cases, wide complex dysrhythmia resolved following intravenous bicarbonate therapy directed at reversing sodium channel blockade.

Adjuvant hormonal treatment with peptide YY or its analog decreases human pancreatic carcinoma growth

BACKGROUND

Recent studies have revealed decreased pancreatic cancer cell growth upon administration of peptide YY (PYY). We examined whether adjuvant treatment with PYY or its synthetic analog, BIM-43004, would decrease human pancreatic adenocarcinoma growth.

MATERIALS AND METHODS

Human pancreatic ductal adenocarcinomas, MiaPaCa-2 and BxPC-3, were cultured and assessed for growth by MTT assay. Pancreatic cancer cells received 500 pmol of PYY or BIM-43004 for 24 hours prior to 5-fluorouracil (5-FU; 10 micrograms/mL) and leucovorin (40 micrograms/mL) administration. Cell membrane epidermal growth factor (EGF) receptors were analyzed by Western blotting after exposure to peptides and chemotherapy.

RESULTS

Cancer cell growth was reduced in all groups receiving hormonal pretreatment (23% PYY/5-FU/leucovorin versus control; 27% BIM-43004/5-FU/leucovorin versus control) as compared with groups receiving 5-FU and leucovorin only (16% versus control). The EGF receptor expression was reduced by 30% in cells treated with PYY/5-FU/leucovorin and by 45% in cells treated with BIM/5-FU/leucovorin as compared with control cells without treatment.

CONCLUSION

Human pancreatic cancer cell growth is further decreased when pretreated with PYY or its synthetic analog prior to chemotherapy.

Assay of apolipoproteins A-1 and B by immunoturbidimetry: detection of individuals at risk for atherosclerotic artery disease

Recent evidence has suggested that the levels of Apolipoprotein A-1 and B in plasma are better indicators of the risk of atherosclerotic artery disease than plasma lipids. This study describes the measurement of plasma Apolipoprotein A-1 and B by immunoturbidimetry in patients with atherosclerotic artery disease and in normal controls. Apoprotein B and the ratio of Apoprotein A-1/Apoprotein B were found to be the best discriminators between the two groups.