Cellworks Omics Biology Model (CBM) to predict therapy response and identify biomarkers for all-trans retinoic acid (ATRA) benefit as addition to induction chemotherapy in adults with acute myeloid leukemia (AML)

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Background: ATRA combined with arsenic trioxide revolutionized the treatment of APL. Based on promising in vitro data, several clinical trials evaluated ATRA combinations in non-APL AML, in which some patients seemed to benefit from the addition. Thus, predicting response a priori is imperative to determine the optimal treatment for each patient. The CBM was used to evaluate the impact of initial therapy with ATRA combined with cytarabine, etoposide, idarubicin (ATRA-CEI) to assess the biomarkers responsible for response in adults with AML. Methods: AML patients participating in clinical trial NCT00151242 had their leukemia sequenced as part of the trial, and genomic profiles were used for computational modeling by the CBM, which uses curated data about genomic aberrations from PubMed as input to generate disease-specific protein network maps and predict drug responses. Disease biomarkers unique to each patient were identified using biosimulation. Digital drug simulations were conducted by measuring the effect of ATRA-CEI on a composite cell growth score of cell proliferation, apoptosis and other hallmarks of cancer. ATRA-CEI was mapped to the patient genome along with a mechanism of action and validated based on the genomic profile and its biological consequences. Results: Of 171 patients treated with ATRA-CEI, 107 (63%) responded (R) and 64 did not (NR). A subset of 18 patients with favorable genomic features were found to be NR and their non-response was correctly predicted by CBM in all 18 cases. Mutations of DNMT3A, EZH2, ASXL, FLT-3, and GART amplification emerged as novel biomarkers of ATRA-CEI failure (only 37 of 107 responders (35%) with these findings, compared to 70 of 107 responders (65%) without these findings (p = 0.0027)). DNMT3A, EZH2, ASXL1 loss of function mutations activate FABP5, a key mechanism of ATRA resistance, and also activate ABCC1 (PgP), which reduces the efficacy of etoposide and idarubicin by upregulating MDR1. In general, monosomy 7 is expected to confer ATRA resistance due to the presence of EZH2 and KMT2E gene deletions. Indeed, 18 of 32 patients with monosomy 7 did not respond. However, the 14 who responded had co-occurrence of deletions involving IGFBP3, PMS2, HUS1, CDK5, XRCC2/4, AKR1B10, and others that overcame ATRA resistance associated with monosomy 7 and were identified by CBM. Use of CBM helps avoid unnecessary use of ATRA in patients unlikely to respond (19% of cases) thus reducing toxicity and cost without changing efficacy, and also identifies those likely to respond, even when they have monosomy 7, where non-response is the norm. Conclusions: ATRA benefits a subset of patients with non-APL AML. CBM predicted response using computational modeling of all genetic alternations, which explains its success versus traditional one-gene-one-drug approaches.

Obesity in midlife: lifestyle and dietary strategies

As the rate of obesity increases globally, so does the incidence of other non-communicable diseases such as diabetes, cardiovascular disease, cancer, osteoporosis, osteoarthritis, and dementia, which have been referred to as 'adiposity-based chronic disease'. With timely lifestyle modification such as behavioral changes, implementation of a healthy diet, and proper physical activity, many of these diseases can be prevented. Weight gain is one of the major health concerns of midlife. Midlife body changes are the result of aging, menopause, and other influences unique to menopausal women which interfere with adoption of a healthy lifestyle. Reduced metabolism levels lead to low energy levels, which discourage physical activity. In addition, with the onset of bone loss, menopausal women begin to lose muscle mass and gain more fat, resulting in osteopenic sarco-obesity. Adoption of a healthy lifestyle is a first-line option in the treatment for these midlife changes. Lifestyle medicine offers a broad set of network-based interventions, which need to be brought to the forefront in preventing and managing obesity at all stages. This review article focuses on evidence-based lifestyle changes and their benefits for reducing morbidity and mortality related to obesity and its complications prevalent at midlife and beyond.

Abstract P1-08-07: Withdrawn

This abstract was withdrawn by the authors.

Effect of Picroliv on cadmium-induced hepatic and renal damage in the rat

The therapeutic efficacy of Picroliv-a standardized-was investigated in male rats exposed to CdCl2 (0.5 mg/kg, sc), 5 days/week for 18 weeks. Picroliv at two doses (6 and 12 mg/kg, po) was given to the cadmium (Cd)-administered group for the last 4 weeks (ie, weeks 15 -18). The Cd altered oxidative stress indices, such as increased lipid peroxidation and membrane fluidity, reduced levels of non-protein sulphydryls (NPSHs), and Na-K-ATPase activity in the liver and kidney were found close to the control values by Picroliv treatment, suggesting its antioxidant potential. The hepatoprotective action of Picroliv was evident by its ability to lower the Cd-induced liver function parameters-the serum enzymes, such as alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), g-glutamyl transpeptidase (GGT) and lactate dehydrogenase (LDH). Bile flow and biliary Cd also increased as a result of Picroliv's choleretic property. The Cd-induced serum urea and urinary excretion of proteins, calcium (Ca), Cd and enzymes, such as Nacetyl-b-D-glucosaminidase (NAG) and LDH, were less marked on Picroliv treatment, indicating recovery from nephrotoxicity. Organ uptake of Cd and essential metals by Cd exposure was reduced on Picroliv treatment. Cdinduced hepatic metallothionein (MT) was lowered by Picroliv, whereas renal MT was unaltered. Cd-induced hepatic damage was also minimized. However, the renal morphological changes were marginally protected by Picroliv. The 12-mg Picroliv dose was more effective than the 6-mg dose in causing amelioration of the above parameters. This study has provided clear evidence for the hepato-and renal protective efficacy of Picroliv against experimental Cd toxicity.

Prevention of acute cadmium toxicity by Picroliv

The potential of Picroliv, a herbal extract against acute cadmium (Cd) intoxication, was evaluated in male rats. Biochemical and histopathological profile in rats pretreated with Picroliv (12 mg/kg, oral) followed by a single dose of Cd as cadmium chloride (CdCl2) (3 mg/kg, ip) revealed marked suppression of oxidative stress in liver and testes. The Cd-induced enhanced levels of lipid peroxidation, membrane fluidity and reduced levels of nonprotein sulphydryls and Na+K+ATPase were significantly restored to near normal by Picroliv pretreatment. In addition, the Cd-induced serum levels of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, gamma glutamyl transpeptidase and lactate dehydrogenase were restored to near basal levels. Hepatic and testicular histopathological damage was also minimized. The results strongly suggest definite hepatoand testicular protection by Picroliv. The antioxidant potential of the herbal extract in the major part, and not its chelating property, seems to be responsible for its ameliorative action.

Changing Pattern of Clinical Profile of First Contact Patients Attending Outpatient Services At the General Hospital Psychiatric Units In India Over the Last 50 Years

Introduction

Over the last eight decades, general hospital psychiatric units (GHPUs) have become important mental health service set-ups in India. This period has seen a large number of radical changes in the Indian society. In this background, it is important to know if it had any effects on the patients attending the GHPUs.

Methodology

A total of five hundred subjects, attending a GHPU were recruited prospectively for the study. The subjects were assessed using a semi-structured proforma. A comparison was made with similar studies conducted in GHPU settings over the last 5 decades.

Results

Neurotic, stress related and somatoform disorders was the commonest diagnostic group (33%) followed by psychotic disorders (17%) and mood disorders (15%). The finding is broadly similar to the studies done at different times in the last 5 decades. However, there were lesser number of patients with mental retardation, organic brain syndrome and seizure disorder.

Conclusion

The study highlights the strengths of GHPU set-ups like inter-speciality referrals, fewer stigmas, patients travelling from far off places to seek treatment and involvement of family in the care of mentally ill.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Heparin enhances uptake of platelet factor 4/heparin complexes by monocytes and macrophages

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is an iatrogenic complication of heparin therapy caused by antibodies to a self-antigen, platelet factor (4) and heparin. The reasons why antibodies form to PF4/heparin, but not to PF4 bound to other cellular glycosaminoglycans are poorly understood.

OBJECTIVE

To investigate differences in cellular responses to cell-bound PF4 and PF4/heparin complexes, we studied the internalization of each by peripheral blood-derived monocytes, dendritic cells and neutrophils.

METHODS AND RESULTS

Using unlabeled and fluorescently-labeled antigen and/or labeled monoclonal antibody to PF4/heparin complexes (KKO), we show that PF4/heparin complexes are taken up by monocytes in a heparin-dependent manner and are internalized by human monocytes and dendritic cells, but not by neutrophils. Complexes of PF4/low-molecular-weight heparin and complexes composed of heparin and murine PF4, protamine or lysozyme are internalized similarly, suggesting a common endocytic pathway. Uptake of complexes is mediated by macropinocytosis, as shown by inhibition using cytochalasin D and amiloride. Internalized complexes are transported intact to late endosomes, as indicated by co-staining of vesicles with KKO and lysosomal associated membrane protein-2 (LAMP-2). Lastly, we show that cellular uptake is accompanied by expression of MHCII and CD83 co-stimulatory molecules.

CONCLUSIONS

Taken together, these studies establish a distinct role for heparin in enhancing antigen uptake and activation of the initial steps in the cellular immune response to PF4-containing complexes.

Pigmented villonodular synovitis great toe

A young boy of 14 years. presented with swelling over dorsal aspect of right great toe, which was slightly tender, non fluctuant. It was excised under subarachnoid block. The mass was golden brown in colour encircling the extensor tendon (Extensor Hallucis Longus Tendon). Histopathology reported to be Pigmented Villonodular Synovitis.

Eliciting a policy response for the rising epidemic of overweight-obesity in India

India is experiencing multiple transitions with respect to nutrition patterns, epidemiology and demography. Along with staggering childhood undernutrition, a rapid rise in chronic diseases and their risk factors including overweight-obesity (O-O), among all sections of society, is compounding India's health challenges. We present an overview of the O-O scenario (prevalence, determinants) and profile existing initiatives to address this modifiable risk factor in India. Urgent attention from all sectors, committed resources, policy support and targeted actions are warranted to combat the dual burden of malnutrition. The health systems should be reoriented and strengthened, in addition to enabling actions in other sectors, to address prevention and control of non-communicable diseases and associated risk factors like O-O.

Genetic and chemical knockdown: a complementary strategy for evaluating an anti-infective target

The equity of a drug target is principally evaluated by its genetic vulnerability with tools ranging from antisense- and microRNA-driven knockdowns to induced expression of the target protein. In order to upgrade the process of antibacterial target identification and discern its most effective type of inhibition, an in silico toolbox that evaluates its genetic and chemical vulnerability leading either to stasis or cidal outcome was constructed and validated. By precise simulation and careful experimentation using enolpyruvyl shikimate-3-phosphate synthase and its specific inhibitor glyphosate, it was shown that genetic knockdown is distinct from chemical knockdown. It was also observed that depending on the particular mechanism of inhibition, viz competitive, uncompetitive, and noncompetitive, the antimicrobial potency of an inhibitor could be orders of magnitude different. Susceptibility of Escherichia coli to glyphosate and the lack of it in Mycobacterium tuberculosis could be predicted by the in silico platform. Finally, as predicted and simulated in the in silico platform, the translation of growth inhibition to a cidal effect was able to be demonstrated experimentally by altering the carbon source from sorbitol to glucose.

Oral mucoceles - review of the literature

Oral mucoceles are mucin filled cavities and lined by ductal epithelium or covered by granulation tissue in retention or extravasation type respectively. The extra-vasation type is very common in the minor salivary glands (particularly in the labial glands), but very infrequent in the major salivary glands, whilst most of the retention cyst affect the major salivary glands. Partial obstruction of duct and spillage of mucin following trauma are the chief etiological factors. Though the two lesions are clinically indistinguishable, the patients are typically older than in the case of extra-vasation type. The case history along with heedful clinical examination of the lesion is crucial for diagnosing mucoceles correctly, but to avoid recurrences histopathological examination is mandatory. The surgical approach to mucoceles is the most common mode of treatment amongst various other techniques including cryosurgery, laser and so on.

MRSA screening in the vascular day-case population

INTRODUCTION

The UK Government has prioritised methicillin-resistant Staphylococcus aureus (MRSA) screening and new operational guidance has instructed that all day-case surgical patients should be screened from April 2009. We sought to identify the number of MRSA-positive patients in the vascular day-case population over a 1-year period and to profile this cohort in terms of risk-factors for MRSA. We also sought to identify whether the new guidance from the Department of Health (DH) had resulted in increased screening rates.

PATIENTS AND METHODS

Electronic records and laboratory culture results were prospectively consulted to identify whether patients had been screened and if MRSA had been isolated. Consideration was given to whether any patients had a delayed discharge or subsequent admission with an MRSA-related complication.

RESULTS

Six patients (2.1%) screened MRSA-positive (DH estimate 7%); five were previously known to be MRSA-positive, therefore only 0.36% patients were newly-identified as MRSA-positive. The proportion of patients screened increased from 35% to 72.5% after April 2009, in accordance with DH guidance. Successful decolonisation was proved in two patients (33.3%).

CONCLUSIONS

There is dispute with several of the key assumptions behind the DH's impact assessment justifying an expanded MRSA-screening policy. It is not cost-effective to screen all vascular day-case admissions. We recommend selective screening for patients previously identified as MRSA-positive, or considered high risk.

Case report: successful use of hyperbaric oxygen therapy for a complete scalp degloving injury

We report a case of a complete scalp degloving injury in a 43-year-old previously healthy, tobacco-using female whose hair was caught in a tractor power take-off causing an instantaneous total scalping injury. Microsurgical replantation was started 4 hours after injury with the surgical procedure lasting 4 hours. Only the superficial temporal arteries were reanastomosed with no venous anastomosis possible. Hyperbaric oxygen (HBO2) treatment at 2.5 atmospheres absolute (ATA) for 90 minutes was administered immediately after surgery due to duskiness of the flap. Further HBO2 treatments were administered twice daily for seven days and then once daily for 30 days. Additionally, leech therapy was used for the first ten postoperative days. The patient's right auricle and most of the left auricle were completely lost. Despite the tenuous vascular inflow and initially absent venous drainage, at 3 month follow-up there was reepithelialization of her scalp except for an area of granulation tissue in the occipitoparietal area. At one year follow-up the area of granulation tissue was reduced, but there was no detectable hair growth or nerve function. We propose that HBO2 may facilitate tissue survival in scalp degloving injuries in the face of incomplete surgical revascularization.

Interference by toxic metal ions with zinc-dependent proteins involved in maintaining genomic stability

Metal ions are essential components of biological systems; nevertheless, even essential elements may have toxic or carcinogenic properties. Thus, besides As(III) and Cd(II), also Ni(II) and Co(II) have been shown previously to disturb different types of DNA repair systems at low, non-cytotoxic concentrations. Since some metals exert high affinities for SH groups, we investigated whether zinc finger structures in DNA-binding motifs of DNA repair proteins are potential targets for toxic metal ions. The bacterial formamidopyrimidine-DNA glycosylase (Fpg protein) involved in base excision repair was inhibited by Cd(II), Cu(II) and Hg(II) with increasing efficiencies, whereas Co(II), As(III), Pb(II) and Ni(II) had no effect. Furthermore, Cd(II) still disturbed enzyme function when bound to metallothionein. Strong inhibition was also observed in the presence of phenylselenyl chloride, followed by selenocystine, while selenomethionine was not inhibitory. Regarding the mammalian XPA protein involved in the recognition of DNA lesions during nucleotide excision repair, its DNA-binding capacity was diminished by Cd(II), Cu(II), Ni(II) and Co(II), while Hg(II), Pb(II) and As(III) were ineffective. Finally, the H(2)O(2)-induced activation of the poly(ADP-ribose)polymerase (PARP) involved in DNA strand break detection and apoptosis was greatly reduced by Cd(II), Co(II), Ni(II) and As(III). Similarly, the disruption of correct p53 folding and DNA binding by Cd(II), Ni(II) and Co(II) has been shown by other authors. Therefore, zinc-dependent proteins involved in DNA repair and cell-cycle control may represent sensitive targets for some toxic metals such as Cd(II), Ni(II), Co(II) and Cu(II), as well as for some selenium compounds. Relevant mechanisms of inhibition appear to be the displacement of zinc by other transition metals as well as redox reactions leading to thiol/disulfide interchange.

Modulation of acute cadmium toxicity by Emblica officinalis fruit in rat

The efficacy of Emblica officinalis in modifying the acute cytotoxicity of cadmium in male rats was evaluated. Oral administration of Emblica fruit juice (500 mg/kg, b.w.) for 8 days followed by a single toxic dose of Cd as CdCl2 (3 mg/kg,b.w. ip), considerably reduced the mortality in rats as well as prevented to some extent the cadmium induced histopathological damage in testis, liver and kidneys. Biochemical investigation also revealed reduced levels of Cd induced serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and gamma glutamyltranspeptidase. The enhanced levels of Cd and lipid peroxidation in liver, kidney, and testes and metallothionein and total sulphydryl in liver and kidney by Cd were significantly reduced by Emblica pretreatment. These results suggest cytoprotective potential of Emblica fruit in acute cadmium toxicity which could be due to its multiple role in biological system.

Accuracy of teen and parental reports of obesity and body mass index

OBJECTIVES

Adolescent obesity is becoming an increasing public health problem. This study determines: 1) differences in teen and parental report of obesity, 2) amount of misclassification using body mass index (BMI) from self-reported versus measured height and weight as an indicator of obesity, and 3) whether misclassification varies by gender and socioeconomic status.

DESIGN

Weighted data from 15 483 baseline (T1) youth and parental interviews from the National Longitudinal Study of Adolescent Health were used. Seventy-four percent of teens were reinterviewed 1 year later (T2). Parents reported socioeconomic status indicators and whether their teen was obese. Teens reported height, weight, and weight perception. BMI was calculated from both self-reported height and weight at T1 and T2 and from measured height and weight at T2. Those with a BMI > or =95% corrected for age and gender were considered obese.

RESULTS

At T1, nearly one half of teens (47%) reporting they were very overweight were not obese by BMI. For teens obese by BMI, 19.6% were reported to be obese by both parent and teen, 6.4% by teen only, 29. 9% by parent only, and 44.2% by neither teen nor parent. For those with persistent obesity, teen and/or parental report failed to identify more than one third (34%) as obese; 23.4% were identified by both teen and parent report, 5.4% by teen report only, and 37.2% by parent only. At T2, the correlation between BMI calculated from self-reported versus measured height and weight for the overall population was very strong (r = .92). Specificity of obesity status based on self-reported BMI, compared with obesity status based on measured BMI was .996; sensitivity, .722; positive predictive value, .860; and negative predictive value, .978. Overall, 3.8% of teens were misclassified using self-report measures. Girls were no more likely than boys to be misclassified as obese using BMI from self-reported height and weight.

CONCLUSIONS

Parental report is a better indicator of obesity than teen report of weight status, but parental and teen reports are both poor predictors of adolescent obesity. Using BMI based on self-reported height and weight correctly classified 96% as to obesity status. Thus, studies can use self-reported height and weight to understand teen obesity and its correlates/sequelae.

Dibutyltin dilaurate induced thymic atrophy and modulation of phosphoinositide pathway of cell signalling in thymocytes of rats

A marked dose dependent reduction in thymus weight and its nucleated cell counts with histological alterations was observed in rats exposed to oral dibutyltin dilaurate (DBTL) for 2 weeks at 2, 4, 8 or 16 mg/kg body weight. The incorporation of [3H]-inositol into all the three major phosphoinositides was drastically reduced in thymocytes in a dose dependent manner. Furthermore, the basal and the mitogen (Con A) stimulated [3H]-inositol phosphates generation was diminished significantly in 8 mg DBTL group. However, in vitro incubation of DBTL with thymocytes failed to evoke any change in phosphoinositide hydrolysis. Similarly, a time and dose dependent inhibition in phosphoinositide synthesis with as high as 80% by 10 microM DBTL was exhibited under in vitro conditions. A 130% and 600% enhancement of protein kinase C (PKC) activity in thymocytes was seen in 4 mg and 8 mg DBTL group, respectively. Addition of DBTL to the cell free assay system of thymocytes resulted in a concentration dependent activation of the enzyme activity. A dose dependent increase in intracellular calcium was also evident when DBTL was added to thymocytes under in vitro conditions. These results are of significance and may bear close relationship to the observed thymic atrophy by DBTL.

Influence of dietary iron deficiency on nickel, lead and cadmium intoxication

The influence of dietary iron deficiency on acute nickel, lead or cadmium toxicity as reflected by the induction of hepatic, renal, and intestinal metallothionein (MT), disposition of the metals and alterations in hematological parameters, was investigated in young rats to ascertain whether the toxic effects of these metals modify under anemic conditions. The administration of Cd induced hepatic, renal and intestinal MT while that of Ni or Pb induced hepatic MT only. While dietary Fe deficiency did not affect MT induction by Cd, it enhanced the synthesis of renal and intestinal MT by Ni and Pb. The accumulation of Pb in liver and kidney and that of Cd in liver only, were enhanced by Fe deficiency; the tissue deposition of Ni remained unaffected by Fe deficiency. The induction of hepatic MT by Ni, Pb or Cd appears to be related to the concomitant rise in the hepatic Zn, Ca and Fe levels in normal rats. However, dietary Fe deficiency increased the hepatic Zn in response to Ni or Cd and the hepatic Ca in response to Pb administration.

Influence of dietary iron deficiency on acute metal intoxication

The influence of dietary iron deficiency on acute nickel, lead or cadmium toxicity as reflected by the induction of hepatic, renal and intestinal metallothionein (MT), disposition of the metals, and alterations in hematological parameters was investigated in rats. The administration of cadmium induced the hepatic, renal and intestinal MT while that of nickel or lead induced hepatic MT only. However, dietary iron deficiency did not influence the cadmium induced tissue MT but enhanced the ability of nickel or lead to restore the normal synthesis of renal and intestinal MT lowered under the influence of reduced body iron status. The accumulation of lead in liver and kidney and that of cadmium enhanced in liver only, while tissue deposition of nickel remained unaffected by iron deficiency. The induction of hepatic MT by three metals appears related to the concomitant rise in the hepatic zinc, calcium and iron levels in normal rats. However, dietary iron deficiency increased the hepatic zinc in response to nickel or cadmium and that of heptic calcium in response to lead.

Prevalence of oesophagitis in asthmatics

The exact relation between gastro-oesophageal reflux and asthma remains poorly understood. To determine whether gastro-oesophageal reflux in asthmatics results in oesophagitis, endoscopy and oesophageal biopsy were performed on 186 consecutive adult asthmatics. The presence or absence of reflux symptoms was not used as a selection criterion for asthmatics. Endoscopy was performed by two endoscopists using predefined criteria. All asthmatics had discrete wheezing and either a previous diagnosis of asthma or documented reversible airways obstruction of at least 20%. The oesophageal mucosa was graded as normal if no erosions or ulcerations were present in the tubular oesophagus; as oesophagitis if a mucosal break with exudate (erosions and/or ulcerations) was present; and as Barrett's if specialised (intestinal) columnar epithelium was present. A hiatal hernia was diagnosed if greater than or equal to 2 cm of gastric mucosa appeared above the diaphragm during endoscopy. Thirty nine per cent of the patients with asthma had oesophagitis or Barrett's oesophagus, or both. There was no difference in the oesophageal mucosal status between asthmatics who required and those who did not require bronchodilators. Fifty eight per cent of asthmatics had a hiatal hernia. It is concluded that oesophagitis is common and independent of the use of bronchodilator therapy in asthmatics.

Biochemical response to cadmium. Dose-time effect

Dose- and time-related effects of Cd (II) (0.5 or 1.0 mg/kg, Cd as CdCl2.H2O, subcutaneously, daily for 48 h, 1, 3, or 6 wk) were investigated in rats. A dose-related increase in the activity of plasma alkaline phosphatase (ALP), lactate dehydrogenase (LDH), aspartate aminotransferase (GOT), and alanine aminotransferase (GPT) was evident only at 6 wk, whereas an early rise in ALP and LDH was seen at 3 wk in 1.0 mg Cd group only. The hepatic and renal metallothionein (MT) induction displayed a dose- as well as time-related increase with Cd accumulation. A significant increase in hepatic Zn and renal Cu, no change in hepatic Cu, and a slight increase in renal Zn was observed. Urinary ALP and leucine aminopeptidase (LAP) showed an initial increase at 48 h, thereafter returned to near normal. A second phase of enzymuria (ALP, LAP, GOT, GPT, gamma-glutamyl transpeptidase), proteinuria, and aminoaciduria occurred at 6 wk in a dose-related manner. The urinary excretion of specific renal enzymes appeared closely related to the MT induction and organ Cd levels.

Most asthmatics have gastroesophageal reflux with or without bronchodilator therapy

The relationship between gastroesophageal reflux and asthma has not been clearly defined. We measured the lower esophageal sphincter pressures and studied gastroesophageal reflux patterns over 24 hours using an ambulatory Gastroreflux Recorder (Del Mar Avionics, Irvine, CA) in 44 controls and 104 consecutive adult asthmatics. The presence or absence of reflux symptoms was not used as a selection criterion for asthmatics. All asthmatics had discrete episodes of diffuse wheezing and documented reversible airway obstruction of at least 20%. Patients underwent reflux testing while receiving, if any, their usual asthmatic medications: 71.2% required chronic bronchodilators and 28.8% required no bronchodilators. Compared with controls, asthmatics had significantly decreased lower esophageal sphincter pressures, greater esophageal acid exposure times, more frequent reflux episodes, and longer clearance times in both the upright and supine positions (P less than 0.0001 for all parameters tested). There were no differences in any of the measured reflux parameters between asthmatics who required bronchodilators and those who did not. Thus, the decreased lower esophageal sphincter pressures and increased levels of acid reflux in asthmatics were not entirely caused by the effects of bronchodilator therapy. Receiver-operating characteristic analysis generated reflux values that discriminated asthmatics from controls. More than 80% of adult asthmatics have abnormal gastroesophageal reflux. We conclude that most adult asthmatics, regardless of the use of bronchodilator therapy, have abnormal gastroesophageal reflux manifested by increased reflux frequency, delayed acid clearance during the day and night, and diminished lower esophageal sphincter pressures.

Effect of positions, eating, and bronchodilators on gastroesophageal reflux in asthmatics

Gastroesophageal reflux is common in asthmatics. To determine whether bronchodilators, the supine position, or eating affect gastroesophageal reflux, we performed ambulatory 24-hr pH monitoring on 44 controls and 104 unselected adult asthmatics. All asthmatics had discrete attacks of wheezing and documented reversible airway obstruction of at least 20%. The presence or absence of gastroesophageal reflux symptoms was not used as a criterion for patient selection. Chronic bronchodilator therapy was required by 71.2% of the asthmatics, and was continued during the test. Asthmatics had significantly worse GER than controls during the 3-hr postprandial period, which continued into the nonpostprandial period up to the next meal. Significant differences were present for esophageal mucosal acid contact time, frequency of reflux episodes, and clearance times. During the nonpostprandial periods asthmatics had four times the acid reflux as controls and 19-fold the frequency of prolonged reflux episodes. There were no differences between asthmatics on bronchodilators and those not on bronchodilators in any of the reflux parameters during the upright (postprandial, nonpostprandial) period or supine (sleep) period (P = NS). We conclude that: (1) regardless of the use of bronchodilator therapy, asthmatics have significant GER when asleep and after meals that continues beyond the postprandial period to the next meal; and (2) asthmatics receiving bronchodilators have similar gastroesophageal reflux patterns after eating, in the nonpostprandial period, and when asleep as asthmatics not receiving bronchodilators.

Nickel-selenium interaction-time dependent biochemical alterations and metal decorporation in rats

The influence of selenium on the disposition of nickel and on Ni induced metallothionein levels was studied in female rats. Concomitant administration of Se (6.3 mumol/kg, intraperitoneally) and 63Ni (0.12 mmol/kg subcutaneously) lowered the Ni burden of all the soft organs and the plasma ceruloplasmin levels. Selenium caused no potentiating effect on the Ni induced hepatic MT. However, 3 days later, the lowered MT levels appeared related to the corresponding decrease in hepatic Ni content at day 6. The Ni selenide excretable complex and Ni-selenide protein complex appear to be probable mechanisms of the Ni-Se interaction in the present study.

Interrelationship between iron deficiency and lead intoxication (Part 2)

The influence of dietary iron deficiency, lead exposure or their combination on certain enzymes, and the accumulation of Pb and essential metal levels in vital organs of rats was investigated. Iron deficiency caused alterations in the activity of muscle, hepatic and renal succinate dehydrogenase, and hepatic mitochondrial succinate cytochrome c reductase, whereas Pb exposure had no influence on these enzymes. There was no synergistic effect of the two factors on the activity of the enzymes. However, feeding of a Fe-deficient diet during Pb exposure enhanced the accumulation of Pb in soft tissues and flat bones. The hepatic copper and zinc levels were lowered upon either feeding a Fe-deficient diet or Pb exposure. However, the synergistic effect of the two factors was evident in hepatic Cu, but not in hepatic Zn. The feeding of a Fe-deficient diet decreased liver, kidney, and spleen levels of Fe, whereas Pb exposure decreased kidney and spleen Fe. The synergistic influence of the two factors could be observed only in liver and kidney.

Influence of diethyldithiocarbamate on nickel-induced hepatic metallothionein in rats

The influence of sodium diethyldithiocarbamate (DDC) on 63nickel chloride-induced metallothionein (MT) and alterations in essential metal levels in the liver of rats was investigated. The induction of MT, Zn and Cu levels of the hepatic cytosolic "heat stable fraction" (HSF) by DDC increased with time up to 24 hr. Although MT, Zn and Cu were significantly greater at 17 hr than those at 6.5 hr after 63Ni administration, the Ni level decreased. The treatment with DDC at 6 hr, but not at 10 min, prior to 63Ni administration increased significantly the MT, Zn and Cu contents 17 hr after 63Ni administration over that caused by 63Ni alone at 17 hr., showing a synergistic effect. The induction of hepatic MT by 63Ni or DDC alone was prevented by cycloheximide but not by actinomycin D and seemed to be regulated at the protein synthesis level.

Chelation in metal intoxication. XXIX: Alpha-mercapto-beta-aryl acrylic acids as antidotes to mercury (II) toxicity

alpha-Mercapto-beta-(2-furyl) acrylic acid (MFA), alpha-mercapto-beta-(phenyl) acrylic acid (MPA), alpha-mercapto-beta-(2-hydroxyphenyl) acrylic acid (MHA), alpha-mercapto-beta-(4-methoxyphenyl) acrylic acid (MMA), beta-1,2-phenylene di-alpha-mercapto acrylic acid (1, 2-PDMA) and beta-1, 4-phenylene di-alpha-mercapto acrylic acid (1, 4-PDMA) enhanced faecal excretion and reduced liver, spleen and blood burden of inorganic mercury when administered (0.5 m mol/kg, in two split doses) 24 hr after Hg (II) (1 mg/kg) in rats. MFA, MPA, MHA, and MMA were also effective in lowering renal Hg mainly from the cytosol, without any significant increase in urinary excretion of Hg. The results indicate that all the mono-mercapto acrylic acids including MFA were more effective than di-mercapto acrylic acids and act through the mechanism characteristic of thiol chelators, that is, mobilization of Hg as their complexes, contrary to the reported observation that MFA acts through the induction of metallothionein.

Chelation in metal intoxication. XXVIII: Effect of thiochelators on mercury (II) toxicity: pre- and post treatment

The effect of treatment with alpha-mercapto-beta-(2-furyl)acrylic acid (MFA), N-(N-mercaptopropionyl) glycine (MPG) and N-acetylcysteine (NAC) compared to spironolactone (SPL), a steroid, before and after 203 mercury (II) exposure, on the disposition of Hg and induction of tissue metallothionein (MT), was investigated in rats. The pretreatment with SPL, MFA and MPG enhanced faecal elimination of Hg and reduced its accumulation in liver particularly, the "heat stable fraction" resulting in lowered hepatic MT induction. Neither the renal uptake of Hg nor induction of tissue MT was affected by pre-treatment with the chelating agents; SPL and MFA causing re-distribution of Hg among the renal sub-cellular fractions. The post-Hg exposure treatment with MFA enhanced the faecal and MPG the urinary excretion of Hg. However, both the chelating agents increased the hepatic burden of Hg as reflected in the subcellular fractions and increased MT contents indicating mobilization of Hg from other tissue binding sites. The post-treatment with MPG however, depleted renal Hg as reflected by the sub-cellular distribution, without affecting renal MT levels. The results show that MFA and MPG are more promising preventive than therapeutic agents in Hg intoxication acting as metal chelators.

Chelation in metal intoxication. XXV: Mercaptoacrylic acids as antidotes of lead and nickel toxicity

beta-1,2-Phenylene di-alpha-mercaptoacrylic acid (1,2-PDMA), beta-1,4-phenylene di-alpha-mercaptoacrylic acid (1,4-PDMA) and alpha-mercapto-beta-(2-hydroxyphenyl) acrylic acid (MHA) were synthesized and compared with 2,3-dimercapto-propane-1-sulfonate (DMPS) for their ability to counteract toxic effects of lead and nickel in rats. 1,2-PDMA and DMPS were most effective in enhancing the excretion of metals, restoring most of the metal induced biochemical alterations and reducing the body burden of the metals; These observations confirm that the chelating agents with two adjacent sulfhydryl groups are better than those with non-adjacent SH groups as metal antidotes. The success of MHA in mobilizing the tissue metals and increasing their urinary excretion indicates participation of the hydroxy group on the benzene nucleus besides the SH group of the MHA molecule, in chelation of the metals.

Chelation in metal intoxication XXVI : Influence of thiamine on the therapeutic efficacy of calcium disodium edetate in lead intoxication

The effect of pretreatment and simultaneous treatment with thiamine on therapeutic efficacy of calcium disodium edetate (CaNa2EDTA) in lead intoxication was investigated in rats. The animals exposed to Pb as Pb (CH3COO)2·3 H2O through drinking water (0.1%) for 8 wk were treated with either saline, thiamine-HCl (sc), CaNa2EDTA (ip), or thiamine-HCl plus CaNa2EDTA, for 3 d or thiamine-HCl for 3 d followed by thiamine, then HCl plus CaNa2EDTA for a further 3 d. The Pb exposure caused significant accumulation of Pb in liver, kideny, and brain, inhibition in the activity of blood δ-amino-levulinic acid dehydratase (δ-ALAD), and increase in levels of urinary δ-aminolevulinic acid, homovanillic acid (HVA), vanillyl mandelic acid (VMA), brain HVA and VMA. The brain δ-ALAD and lipomide dehydrogenase remained unaffected by Pb. Thiamine significantly enhanced the urinary excretion of Pb by CaNa2EDTA, but only marginally influenced the efficacy of CaNa2EDTA to either mobilize tissue Pb or reverse the biochemical alterations.