Folinic acid improves verbal communication in children with autism and language impairment: a randomized double-blind placebo-controlled trial.

We sought to determine whether high-dose folinic acid improves verbal communication in children with non-syndromic autism spectrum disorder (ASD) and language impairment in a double-blind placebo control setting. Forty-eight children (mean age 7 years 4 months; 82% male) with ASD and language impairment were randomized to receive 12 weeks of high-dose folinic acid (2 mg kg-1 per day, maximum 50 mg per day; n=23) or placebo (n=25). Children were subtyped by glutathione and folate receptor-α autoantibody (FRAA) status. Improvement in verbal communication, as measured by a ability-appropriate standardized instrument, was significantly greater in participants receiving folinic acid as compared with those receiving placebo, resulting in an effect of 5.7 (1.0,10.4) standardized points with a medium-to-large effect size (Cohen's d=0.70). FRAA status was predictive of response to treatment. For FRAA-positive participants, improvement in verbal communication was significantly greater in those receiving folinic acid as compared with those receiving placebo, resulting in an effect of 7.3 (1.4,13.2) standardized points with a large effect size (Cohen's d=0.91), indicating that folinic acid treatment may be more efficacious in children with ASD who are FRAA positive. Improvements in subscales of the Vineland Adaptive Behavior Scale, the Aberrant Behavior Checklist, the Autism Symptom Questionnaire and the Behavioral Assessment System for Children were significantly greater in the folinic acid group as compared with the placebo group. There was no significant difference in adverse effects between treatment groups. Thus, in this small trial of children with non-syndromic ASD and language impairment, treatment with high-dose folinic acid for 12 weeks resulted in improvement in verbal communication as compared with placebo, particularly in those participants who were positive for FRAAs.

Determining the composition of the vacuum-liquid interface in ionic-liquid mixtures.

The vacuum-liquid interfaces of a number of ionic-liquid mixtures have been investigated using the combination of reactive-atom scattering with laser-induced fluorescence detection (RAS-LIF), selected surface tension measurements, and molecular dynamics (MD) simulations. The mixtures are based on the widespread 1-alkyl-3-methylimidazolium ([Cnmim]+) cation, including mixed cations which differ in chain length or chemical functionality with a common anion; and different anions for a common cation. RAS-LIF results imply that the surface compositions exhibit a general form of non-stoichiometric behaviour that mimics the well-known Henry's and Raoult's laws at low and high mole fraction, respectively. The extended Langmuir model provides a moderately good single-parameter fit, but higher-order terms are required for an accurate description. The quantitative relationship between RAS-LIF and surface tension, which probes the surface composition only indirectly, is explored for mixtures of [C2mim]+ and [C12mim]+ with a common bis(trifluoromethylsulfonyl)imide ([NTf2]-) anion. Extended Langmuir model fits to surface tension data are broadly consistent with those to RAS-LIF; however, several other common approaches to extracting surface compositions from measured surface tensions result in much larger discrepancies. MD simulations suggest that RAS-LIF faithfully reports on the alkyl-chain exposure at the surface, which is only subtly modified by composition-dependent structural reorganisation.

Incidence rates and trends of hip/femur fractures in five European countries: comparison using e-healthcare records databases.

Hip fractures represent a major public health challenge worldwide. Multinational studies using a common methodology are scarce. We aimed to estimate the incidence rates (IRs) and trends of hip/femur fractures over the period 2003-2009 in five European countries. The study was performed using seven electronic health-care records databases (DBs) from Denmark, The Netherlands, Germany, Spain, and the United Kingdom, based on the same protocol. Yearly IRs of hip/femur fractures were calculated for the general population and for those aged ≥50 years. Trends over time were evaluated using linear regression analysis for both crude and standardized IRs. Sex- and age-standardized IRs for the UK, Netherlands, and Spanish DBs varied from 9 to 11 per 10,000 person-years for the general population and from 22 to 26 for those ≥50 years old; the German DB showed slightly higher IRs (about 13 and 30, respectively), whereas the Danish DB yielded IRs twofold higher (19 and 52, respectively). IRs increased exponentially with age in both sexes. The ratio of females to males was ≥2 for patients aged ≥70-79 years in most DBs. Statistically significant trends over time were only shown for the UK DB (CPRD) (+0.7% per year, P < 0.01) and the Danish DB (-1.4% per year, P < 0.01). IRs of hip/femur fractures varied greatly across European countries. With the exception of Denmark, no decreasing trend was observed over the study period.

Antidepressant prescribing in five European countries: application of common definitions to assess the prevalence, clinical observations, and methodological implications.

PURPOSE: Drug utilization studies have applied different methods to various data types to describe medication use, which hampers comparisons across populations. The aim of this study was to describe the time trends in antidepressant prescribing in the last decade and the variation in the prevalence, calculated in a uniform manner, in seven European electronic healthcare databases. METHODS: Annual prevalence per 10,000 person-years (PYs) was calculated for 2001-2009 in databases from Spain, Germany, Denmark, the United Kingdom (UK), and the Netherlands. Prevalence data were stratified according to age, sex, antidepressant type (selective serotonin re-uptake inhibitors [SSRIs] or tricyclic antidepressants [TCAs]) and major indications. RESULTS: The age- and sex-standardized prevalence was lowest in the two Dutch (391 and 429 users per 10,000 PYs) and highest in the two UK (913 and 936 users per 10,000 PYs) populations in 2008. The prevalence in the Danish, German, and Spanish populations was 637, 618, and 644 users per 10,000 PY respectively. Antidepressants were prescribed most often in 20- to 60-year-olds in the two UK populations compared with the others. SSRIs were prescribed more often than TCAs in all except the German population. In the majority of countries we observed an increasing trend of antidepressant prescribing over time. Two different methods identifying recorded indications yielded different ranges of proportions of patients recorded with the specific indication (15-57% and 39-69% for depression respectively). CONCLUSION: Despite applying uniform methods, variations in the prevalence of antidepressant prescribing were obvious in the different populations. Database characteristics and clinical factors may both explain these variations.

Evaluation of an endoscopic suturing device for transoral outlet reduction in patients with weight regain following Roux-en-Y gastric bypass.

BACKGROUND AND STUDY AIMS: A dilated gastrojejunal anastomosis (GJA) is thought to be associated with weight regain in patients with Roux-en-Y gastric bypass (RYGB). Due to a high rate of perioperative morbidity, surgical revision is not generally performed. The aim of this study was to assess the technical feasibility, safety, and early outcomes of a procedure using a commercially available endoscopic suturing device to reduce the diameter of the GJA. PATIENTS AND METHODS: This was a retrospective analysis of 25 consecutive patients who underwent transoral outlet reduction (TORe) for dilated GJA and weight regain. An endoscopic suturing device was used to place sutures at the margin of the GJA in order to reduce its aperture. On chart review, clinical data were available at 3, 6, and 12 months. RESULTS: Patients had regained a mean of 24 kg from their weight loss nadir and had a mean body mass index of 43 kg/m2 at the time of endoscopic revision. Average anastomosis diameter was 26.4 mm. Technical success was achieved in all patients (100 %) with a mean reduction in anastomosis diameter to 6 mm (range 3 - 10 mm), representing a 77.3 % reduction. The mean weight loss in successful cases was 11.5 kg, 11.7 kg, and 10.8 kg at 3, 6, and 12 months, respectively. There were no major complications. CONCLUSION: This case series demonstrated the technical feasibility, safety, and efficacy of performing gastrojejunostomy reduction using a commercially available endoscopic suturing device. This technique may represent an effective and minimally invasive option for the management of weight regain in patients with RYGB.

Anti-tissue factor short hairpin RNA inhibits breast cancer growth in vivo.

In breast cancer, there is a correlation between tissue factor (TF) expression, angiogenesis and disease progression. TF stimulates tumour angiogenesis, in part, through up-regulation of vascular endothelial growth factor (VEGF). Therefore, this study aimed to establish whether TF stimulates angiogenesis and tumour progression directly and independent of VEGF up-regulation. Initially, the effects of TF and VEGF were assessed on endothelial cell migration (Boyden chamber) and differentiation (tubule formation on Matrigel). Subsequently, MDA-MB-436 breast cancer cells, which produce high levels of both TF and VEGF (western blot analysis), were established in vivo, following which tumours were treated three times per week for 3 weeks with intra-tumoural injections of either anti-VEGF siRNA, anti-TF shRNA, the two treatments combined, or relevant controls. Both VEGF and TF significantly stimulated endothelial cell migration and tubule formation (P < 0.02). Breast cancer xenografts (MDA-MB-436) treated with TF or VEGF-specific agents demonstrated significant inhibition in tumour growth (VEGFsiRNA 61%; final volume: 236.2 ± 23.2 mm(3) vs TFshRNA 89%; 161.9 ± 17.4 mm(3) vs combination 93%; 136.3 ± 9.2 mm(3) vs control 400.4 ± 32.7 mm(3); P < 0.005). Microvessel density (MVD), a measure of angiogenesis, was also significantly inhibited in all groups (MVD in control = 29 ± 2.9; TFshRNA = 18 ± 1.1; VEGFsiRNA = 16.7 ± 1.5; both = 12 ± 2.1; P < 0.004), whereas the proliferative index of the tumours was only reduced in the TFshRNA-treated groups (control = 0.51 ± 0.011; TFshRNA = 0.41 ± 0.014; VEGFsiRNA = 0.49 ± 0.013; both = 0.41 ± 0.004; P < 0.008). These data suggest that TF has a direct effect on primary breast cancer growth and angiogenesis, and that specific inhibition of the TF-signalling pathway has potential for the treatment of primary breast cancer.

Genetic evidence for two species of elephant in Africa.

Elephants from the tropical forests of Africa are morphologically distinct from savannah or bush elephants. Dart-biopsy samples from 195 free-ranging African elephants in 21 populations were examined for DNA sequence variation in four nuclear genes (1732 base pairs). Phylogenetic distinctions between African forest elephant and savannah elephant populations corresponded to 58% of the difference in the same genes between elephant genera Loxodonta (African) and Elephas (Asian). Large genetic distance, multiple genetically fixed nucleotide site differences, morphological and habitat distinctions, and extremely limited hybridization of gene flow between forest and savannah elephants support the recognition and conservation management of two African species: Loxodonta africana and Loxodonta cyclotis.

Use of ultrasound-guided axillary node core biopsy in staging of early breast cancer.

The aim of this study was to see how effective ultrasound-guided needle biopsy was at detecting lymph node involvement in patients with early breast cancer. Patients with newly diagnosed invasive breast cancer underwent axillary ultrasound (US) where lymph node size and morphology were noted. A core biopsy (CB) was undertaken of any node greater than 5 mm in longitudinal section. Patients with benign CBs proceeded to sentinel lymph node (SLN) biopsy, whereas those with malignancy underwent axillary lymph node dissection (ALND). US and CB findings were correlated with final surgical histology in all cases. One hundred and thirty-nine patients were examined, of whom 52.5% had lymph node metastases on final histology. One hundred and twenty-one patients (87%) underwent axillary node CB. The overall sensitivity of CB for detecting lymph node metastases was 53.4% (60.3% for macrometastases; 26.7% for micrometastases). The US morphological characteristics most strongly associated with malignancy were absence of a hilum and a cortical thickness greater than 4 mm. However, one third of patients with normal lymph node morphology had nodal metastases, and only 12% of these were diagnosed on CB. CB of axillary lymph nodes can diagnose a substantial number of patients with lymph node metastases, allowing these patients to proceed directly to ALND, avoiding unnecessary SLN biopsy.

Evolution of the male-determining gene SRY within the cat family Felidae.

In most placental mammals, SRY is a single-copy gene located on the Y chromosome and is the trigger for male sex determination during embryonic development. Here, we present comparative genomic analyses of SRY (705 bp) along with the adjacent noncoding 5' flank (997 bp) and 3' flank (948 bp) in 36 species of the cat family Felidae. Phylogenetic analyses indicate that the noncoding genomic flanks and SRY closely track species divergence. However, several inconsistencies are observed in SRY. Overall, the gene exhibits purifying selection to maintain function (omega = 0.815) yet SRY is under positive selection in two of the eight felid lineages. SRY has low numbers of nucleotide substitutions, yet most encode amino acid changes between species, and four different species have significantly altered SRY due to insertion/deletions. Moreover, fixation of nonsynonymous substitutions between sister taxa is not consistent and may occur rapidly, as in the case of domestic cat, or not at all over long periods of time, as observed within the Panthera lineage. The former resembles positive selection during speciation, and the latter purifying selection to maintain function. Thus, SRY evolution in cats likely reflects the different phylogeographic histories, selection pressures, and patterns of speciation in modern felids.

Disposition of acetaminophen at 4, 6, and 8 g/day for 3 days in healthy young adults.

The objective of this study was to determine the disposition and tolerability of 1, 1.5, and 2 g acetaminophen every 6 h for 3 days. Group I healthy adults received acetaminophen (4 then 6 g/day) or placebo; Group II received acetaminophen (4 then 8 g/day) or placebo. Acetaminophen and metabolites were measured in plasma and urine. Hepatic aminotransferases were measured daily. At steady state, acetaminophen concentrations were surprisingly lower than predicted from single-dose data, although sulfate formation clearance (fCL) was lower as expected, indicating cofactor depletion with possible sulfotransferase saturation. In contrast, glucuronide fCL was unexpectedly higher, strongly suggesting glucuronosyltransferase induction. This is the first evidence that acetaminophen induces its own glucuronidation. No dose-dependent differences were detected in fCL of thiol metabolites formed via cytochrome P4502E1. Hepatic aminotransferases stayed within reference ranges, and the incidence and frequency of adverse events were similar for acetaminophen and placebo. Although dose-dependence of acetaminophen disposition was reported previously, this study shows a novel finding of time-dependent disposition during repeated dosing. Unexpected increases in glucuronide fCL more than offset decreases in sulfate fCL, thus increasing acetaminophen clearance overall. Thiol metabolite fCL remained constant up to 8 g/day. These findings have important implications in short-term (3 day) tolerability of supratherapeutic acetaminophen doses in healthy adults.

The effect of acetaminophen (four grams a day for three consecutive days) on hepatic tests in alcoholic patients--a multicenter randomized study.

BACKGROUND: Hepatic failure has been associated with reported therapeutic use of acetaminophen by alcoholic patients. The highest risk period for alcoholic patients is immediately after discontinuation of alcohol intake. This period exhibits the largest increase in CYP2E1 induction and lowest glutathione levels. Our hypothesis was that common liver tests would be unaffected by administration of the maximum recommended daily dosage of acetaminophen for 3 consecutive days to newly-abstinent alcoholic subjects. METHODS: Adult alcoholic subjects entering two alcohol detoxification centers were enrolled in a prospective double-blind, randomized, placebo-controlled trial. Subjects were randomized to acetaminophen, 4 g/day, or placebo for 3 consecutive days. The study had 95% probability of detecting a 15 IU/L difference in serum ALT. RESULTS: A total of 443 subjects were enrolled: 308 (258 completed) received acetaminophen and 135 subjects (114 completed) received placebo. Study groups did not differ in demographics, alcohol consumption, nutritional status or baseline laboratory assessments. The peak mean ALT activity was 57 +/- 45 IU/L and 55 +/- 48 IU/L in the acetaminophen and placebo groups, respectively. Subgroup analyses for subjects presenting with an elevated ALT, subjects fulfilling a diagnosis of alcoholic hepatitis and subjects attaining a peak ALT greater than 200 IU/L showed no statistical difference between the acetaminophen and control groups. The one participant developing an increased international normalized ratio was in the placebo group. CONCLUSION: Alcoholic patients treated with the maximum recommended daily dose of acetaminophen for 3 consecutive days did not develop increases in serum transaminase or other measures of liver injury. Treatment of pain or fever for 3 days with acetaminophen appears safe in newly-abstinent alcoholic patients, such as those presenting for acute medical care.

Thyroid dysfunction in children with autism spectrum disorder is associated with folate receptor α autoimmune disorder.

Folate receptor α (FRα) autoantibodies (FRAAs) are prevalent in autism spectrum disorder (ASD). FRAAs disrupt folate transport across the blood-brain barrier by binding to the FRα. Thyroid dysfunction is frequently found in children with ASD. We measured blocking and binding FRAAs and thyroid-stimulating hormone (TSH), free thyroxine (T4) (FT4), total triiodothyronine (T3) (TT3), reverse T3 (rT3), thyroid-releasing hormone (TRH) and other metabolites in 87 children with ASD, 84 of whom also underwent behaviour and cognition testing and in 42 of whom FRAAs, TSH and FT4 were measured at two time points. To better understand the significance of the FRα in relation to thyroid development, we examined FRα expression on prenatal and postnatal thyroid. TSH, TT3 and rT3 were above the normal range in 7%, 33% and 51% of the participants and TRH was below the normal range in 13% of the participants. FT4 was rarely outside the normal range. TSH concentration was positively and the FT4/TSH, TT3/TSH and rT3/TSH ratios were inversely related to blocking FRAA titres. On repeated measurements, changes in TSH and FT4/TSH ratio were found to correspond to changes in blocking FRAA titres. TSH and the FT4/TSH, TT3/TSH and rT3/TSH ratios were related to irritability on the Aberrant Behavior Checklist and several scales of the Social Responsiveness Scale (SRS), whereas TT3 was associated with SRS subscales and TRH was related to Vineland Adaptive Behavior Scale subscales. The thyroid showed significant FRα expression during the early prenatal period, although expression decreased significantly in later gestation and postnatal thyroid tissue. The results of the present study suggest that thyroid dysfunction in ASD may be related to blocking FRAA. The high expression of FRα in the early foetal thyroid suggests that foetal and neonatal exposure to maternal FRAAs could affect the development of the thyroid and may contribute to the pathology in ASD.

Peroral endoscopic reduction of dilated gastrojejunal anastomosis after Roux-en-Y gastric bypass: a possible new option for patients with weight regain.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is an effective treatment for severe obesity. However, many patients regain weight over time. The mechanisms for this are unclear, and several factors may contribute, including dilation of the gastrojejunal anastomosis. This study aimed to assess the feasibility of endoscopic gastrojejunal anastomotic tightening and to determine the effect of tightening on body weight. METHODS: Eight patients with significant weight regain and dilated gastrojejunal anastomosis after RYGB were included in this pilot study. Sutures were placed endoscopically at the rim of the anastomosis. When tightened, the sutures formed tissue placations, reducing the size of the anastomotic aperture. RESULTS: The average preprocedure body mass index (BMI) was 40.5, and the patients had regained a mean of 24 kg from their post-RYGB nadir. The average pouch length was 5.7 cm, and the average anastomotic diameter was 25 mm. The average postreduction diameter was 10.0 mm (68% reduction). Six of the eight patients showed weight loss (mean, 10 kg) at 4 months. Repeat procedures were performed for three patients who had lost 4, 5, and 9 kg, respectively with the initial procedure. After the second anastomotic reduction, the final diameters were, respectively, 14, 5, and 5 mm. The first patient did not have further weight loss. The remaining two patients showed a total weight loss of 19 and 20 kg, respectively, at 5 months. All 11 reductions were accomplished without significant complication. The average postreduction BMI was 37.7, and the percentage of excess weight loss was 23.4%. CONCLUSION: Peroral endoscopic suturing to tighten dilated gastrojejunal anastomoses appears technically feasible and safe. This procedure is associated with variable but significant weight loss, and preliminary results suggest that it may offer a new treatment option for postbypass weight regain in selected patients.

T-lymphocyte profiles in FIV-infected wild lions and pumas reveal CD4 depletion.

Feline immunodeficiency virus (FIV) is a lentivirus related to human immunodeficiency virus (HIV) that causes feline AIDS in the domestic cat (Felis catus). Serological surveys indicate that at least 25 other species of cat possess antibodies that cross-react with domestic cat FIV. Most infected nondomestic cat species are without major symptoms of disease. Long-term studies of FIV genome variation and pathogenesis reveal patterns consistent with coadaptation of virus and host in free-ranging FIV-Ple-infected African lions (Panthera leo) and FIV-Pco-infected pumas (Puma concolor) populations. This report examined correlates of immunodeficiency in wild and captive lions and pumas by quantifying CD5(+), CD4(+), and CD8(+) T-cell subsets. Free-ranging FIV-Ple-infected lions had immunofluorescence flow cytometry (IFC) profiles marked by a dramatic decline in CD4(+) subsets, a reduction of the CD4(+)/CD8(+) ratio, reduction of CD8(+)beta(high) cells, and expansion of the CD8(+)beta(low) subset relative to uninfected lions. An overall significant depletion in CD5(+) T-cells in seropositive lions was linked with a compensatory increase in total CD5(-) lymphocytes. The IFC profiles were altered significantly in 50% of the seropositive individuals examined. The FIV-Pco-infected pumas had a more generalized response of lymphopenia expressed as a significant decline in total lymphocytes, CD5(+) T-cells, and CD5(-) lymphocytes as well as a significant reduction in CD4(+) T-cells. Like lions, seropositive pumas had a significant decline in CD8(+)beta(high) cells but differed by not having compensatory expansion of CD8(+)beta(low) cells relative to controls. Results from FIV-infected lions and pumas parallel human and Asian monkey CD4(+) diminution in HIV and SIV infection, respectively, and suggest there may be unrecognized immunological consequences of FIV infection in these two species of large cats.

Busulfan-glutathione conjugation catalyzed by human liver cytosolic glutathione S-transferases.

We have examined the catalytic activity of glutathione S-transferases (GST) in the conjugation of busulfan with glutathione (GSH) in human liver cytosol, purified human liver GST, and cDNA-expressed GST-alpha 1-1. Human liver microsomes and cytosol were incubated with 40 microM busulfan and 1 mM GSH. Cytosol catalyzed the formation of the GSH-busulfan tetrahydrothiophenium ion (THT+) in a concentration-dependent manner, whereas microsomes lacked activity. The total and spontaneous rates of THT+ formation increased with pH (pH range, 6.50-7.75), with the maximum difference at pH 7.4. Due to the limited aqueous solubility of busulfan, a K(m) for busulfan was not determined. The intrinsic clearance (Vmax/K(m)) of busulfan conjugation was 0.167 microliter/min/mg with 50-1200 microM busulfan and 1 mM GSH. GSH Vmax and K(m) for busulfan conjugation were 30.6 pmol/min/mg and 312 microM, respectively. Ethacrynic acid (0.03-15 microM) inhibited cytosolic busulfan-conjugating activity with 40 microM busulfan and 1 mM GSH. Enzyme-mediated THT+ formation was decreased 97% by 15 microM ethacrynic acid with no effect on the spontaneous reaction. In incubations with affinity-purified liver GST and GST-alpha 1-1, the intrinsic clearance for busulfan conjugation was 0.87 and 2.92 microliters/min/mg, respectively. Busulfan is a GST substrate with a high K(m) relative to concentrations achieved clinically (1-8 microM).

Oxidation of cyclophosphamide to 4-hydroxycyclophosphamide and deschloroethylcyclophosphamide in human liver microsomes.

We have investigated the formation of 4-hydroxycyclophosphamide (HCY) and deschloroethylcyclophosphamide (DCCY) from cyclophosphamide (CY) in human liver microsomes. For HCY, the estimated values (mean +/- SD; n = 3) of Km1 and Km2 were 0.095 +/- 0.072 and 5.09 +/- 4.30 mM, and the estimated values of Vmax1 and Vmax2 were 0.138 +/- 0.070 and 1.55 +/- 0.50 nmol/min/mg protein. For DCCY, Km1 and Km2 were 0.046 +/- 0.017 and 8.58 +/- 5.84 mM, and Vmax1 and Vmax2 were 0.006 +/- 0.003 and 0.274 +/- 0.214 nmol/min/mg protein. At CY concentrations of 0.1, 0.7, and 5 mM, HCY respectively accounted for 95.7 +/- 1.3, 95.1 +/- 2.4, and 90.7 +/- 2.7% of the total products of CY (HCY + DCCY; n = 6). In a separate experiment, 98.7 +/- 11.9% (n = 3) of CY loss could be accounted for by the formation of HCY at 0.1 mM CY. On the basis of cytochrome P450 (CYP) isoform-specific chemical inhibitor and cDNA-expressed human P450 isozyme studies, CYP2C9 and CYP3A4/5 seemed to be the major P450 isoforms responsible for HCY formation at low (0.1 mM) and high (0.7 and 5 mM) concentrations of CY, respectively. Although orphenadrine inhibition was observed in human liver microsomes (which has been taken to indicate CYP2B6 catalysis), orphenadrine inhibited cDNA-expressed CYP3A4 formation of HCY to the same extent observed in human liver microsomes, and the addition of orphenadrine to incubations containing sulfaphenazole (a specific inhibitor of CYP2C9) or troleandomycin (a specific CYP3A inhibitor) did not increase inhibition beyond that observed with sulfaphenazole or troleandomycin alone. Similar studies indicated that CYP3A4/5 was the major P450 isoform responsible for DCCY formation at high (0.7 and 5 mM) concentrations of CY. The P450 isoform responsible for DCCY formation at 0.1 mM CY could not be identified due to its very low formation rate.

Phase Ib trial of pentoxifylline and ciprofloxacin in patients treated with interleukin-2 and lymphokine-activated killer cell therapy for metastatic renal cell carcinoma.

The dose of interleukin 2 (IL-2) which can be administered to cancer patients is limited largely by a capillary leak syndrome. Pentoxifylline (PTX) is a methylxanthine which reduces IL-2 toxicity in animals. Ciprofloxacin (Cipro) modifies the metabolism of methylxanthines and, when coadministered with PTX, increases levels of PTX and certain of its metabolites. We conducted a phase Ib trial in patients receiving IL-2 and lymphokine-activated killer cell (LAK) cell therapy for metastatic renal cell carcinoma to identify the maximum tolerated dose of PTX which could be coadministered with Cipro in this setting. Eighteen patients received IL-2 (Roche) by continuous infusion at 6 x 10(6) units/m2/day on days 1-5 and underwent leukapheresis on days 7-9. LAK cells were infused on days 12-14. IL-2 was administered at 2 x 10(6) units/m2/day on days 10-20. Cohorts of patients received PTX at 2.5 (n = 3), 3.1 (n = 6), 3.9 (n = 6), and 4.9 (n = 3) mg/kg by 30 min i.v. infusion every 4 h on days 0-5 and 10-20 and Cipro (500 mg p.o. every 12 h) on days 1-5 and 10-20. Toxicity was compared with that observed in 33 historical control patients who received 37 cycles of an identical regimen of IL-2/LAK without PTX/Cipro. PTX at 2.5-3.9 mg/kg and Cipro were well tolerated. The maximum tolerated dose of PTX was 3.9 mg/kg. Dose-limiting emesis (n = 1) and atrial fibrillation (n = 2) occurred at 4.9 mg/kg and were reversible. Two complete, one partial and one minor, responses were observed. Patients treated with 3.9 mg/kg PTX received 95.0% of the planned dose of IL-2 as compared to 72.8% in the control patients (P < 0.025), primarily due to a lower incidence of azotemia and metabolic acidosis in PTX/Cipro recipients than had been seen in the historical control patients. The results of this study demonstrate that PTX/Cipro can be administered to patients receiving IL-2/LAK without apparent loss of therapeutic efficacy. Moreover, PTX/Cipro recipients exhibited less toxicity than historical controls. Therefore, treatment with PTX/Cipro may allow delivery of higher doses of IL-2, which might induce more responses in IL-2-responsive tumors and regression of tumors unresponsive to conventional doses of IL-2.

Age-dependent tetrahydrothiophenium ion formation in young children and adults receiving high-dose busulfan.

Busulfan, a bifunctional alkylating agent, is a mainstay of myeloablative preparative regimens before hematopoietic stem cell transplantation. The apparent oral clearance of busulfan expressed relative to body surface area is 2-3-fold higher in children 1-4 years old than it is in adults. The first step in busulfan elimination is the formation of a tetrahydrothiophenium ion (THT+) in a glutathione S-transferase-catalyzed reaction. We present computer simulations that demonstrate that the ratio of the AUC of THT+ to that of busulfan over 6 h [(AUC(THT+)/AUC(BU))(0-->6)] is highly correlated (r2 = 0.805) with the determinants of THT+ formation and is virtually independent of the determinants of its elimination (r2 = 0.0201). We compared (AUC(THT+)/AUC(BU))(0-->6) determined in 14 children (0.5-4 years) to that of 11 adults (12-54 years) and found a 1.5-fold elevation in the area ratio (P = 0.0098) and a similarly significant increase in busulfan apparent oral clearance expressed relative to body surface area (P = 0.042). The only common explanation for the elevated busulfan apparent oral clearance and (AUC(THT+)/AUC(BU))(0-->6) is an enhanced ability of children to metabolize busulfan through glutathione conjugation.

Systemic lidocaine enhancement of hyperthermia-induced tumor regression in transplantable murine tumor models.

Previously, we reported that local lidocaine infusion of a CA 755 mammary adenocarcinoma growing in C57BL X DBA/2 F1 mice, when combined with local heating for 1 hr in a 43.5 degrees water bath, significantly increased survival and inhibited tumor growth more than heating alone. Because of its clinical implications, systemic lidocaine was tested in the above model system and in a murine fibrosarcoma tumor model. An equivalent supraadditive, tumor-inhibitory effect of heat and lidocaine was obtained with both systemically and intratumor-administered lidocaine. The serum levels of lidocaine necessary to achieve tumor regression were within the therapeutic range for the control of arrhythmia in humans. Several treatment schedules, varying the mode of drug delivery, were evaluated. The effects of treatment on tumor growth characteristics were analyzed using an extension of the Cox survival model.