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Biomedical subjects

R Ali

Publications and source records attributed to R Ali.

At least 55 records · Page 3Linked to original sources

Binding of SLE autoantibodies to native poly(I), ROS-poly(I) and native DNA: a comparative study.

Reactive oxygen species (ROS) are implicated in a variety of human diseases. The formation of pathogenic anti-DNA antibodies in systemic lupus erythematosus (SLE) has been extensively investigated. ROS-modified DNA has been found to be a better antigen for anti-DNA antibodies found in SLE sera. A comparative binding of SLE autoantibodies with native poly(I), ROS-poly(I) and nDNA has been studied. Affinity-purified SLE IgG exhibited a high degree of specificity towards the ROS-modified poly(I) in comparison to native DNA and native poly(I), reiterated visually by gel retardation assay. The data suggested that hydroxyl radical-modified nucleic acids like RNA and DNA might be agent for the induction of circulating SLE anti-DNA autoantibodies.

Antibodies, Antinuclear↗

Emergency medicine in China: redefining a specialty.

The People's Republic of China (PRC) is developing a unique system of emergency medical facilities based on its own conditions, adapting elements of both North American and European models, as well as creating some of its own. This ongoing evolution of a system for provision of emergency medical care reflects a society that is itself in rapid transition. There have been great strides in the advancement of this specialty over the last two decades. China now has an Emergency Medicine (EM) association, training programs, and specialty journals. Nevertheless, although an organizational framework now exists, development of EM in China as a whole can be said to be at an early stage. The number of trained practitioners is still small, and EMS providers are generally not trained or integrated except in a few large cities. By all estimates, the pace of growth of EM in China will continue to accelerate as China's economy and demographics approach those of the west, but the final form they will take is still uncertain.

Cause of Death↗

Antigenicity of poly(I) and ROS-poly(I) and their recognition of human anti-DNA autoantibodies.

The effect of hydroxyl radicals on polyinosinic acid [poly(I)] was studied. Strand breaks, base alteration and a decrease in absorbance at 248 nm (lambda max) were observed upon *OH modification of poly(I). The broad antigen specificity of the induced anti-poly(I) and anti-ROS-poly(I) antibodies showed diverse antigen binding characteristics similar to those of SLE autoantibodies. Recognition of both poly(I) and ROS-poly(I) by human SLE anti-DNA autoantibodies was observed. The possible significance of these findings in the etiology of SLE has been discussed.

Animals↗

Nipah virus infection among abattoir workers in Malaysia, 1998-1999.

BACKGROUND: An outbreak of encephalitis primarily affecting pig farmers occurred during 1998-1999 in Malaysia and was linked to a new paramyxovirus, Nipah virus, which infected pigs, humans, dogs, and cats. Because five abattoir workers were also affected, a survey was conducted to assess the risk of Nipah infection among abattoir workers. METHODS: Workers from all 143 registered abattoirs in 11 of 13 states in Malaysia were invited to participate in this cross-sectional study. Participants were interviewed to ascertain information on illness and activities performed at the abattoir. A serum sample was obtained to test for Nipah virus antibody. RESULTS: Seven (1.6 %) of 435 abattoir workers who slaughtered pigs versus zero (0%) of 233 workers who slaughtered ruminants showed antibody to Nipah virus (P = 0.05). All antibody-positive workers were from abattoirs in the three states that reported outbreak cases among pig farmers. Workers in these three states were more likely than those in other states to have Nipah antibody (7/144 [4.86%] versus 0/291 [0%], P < 0.001) and report symptoms suggestive of Nipah disease in pigs admitted to the abattoirs (P = 0.001). CONCLUSIONS: Nipah infection was not widespread among abattoir workers in Malaysia and was linked to exposure to pigs. Since it may be difficult to identify Nipah-infected pigs capable of transmitting virus by clinical symptoms, using personal protective equipment, conducting surveillance for Nipah infection on pig farms which supply abattoirs, and avoiding handling and processing of potentially infected pigs are presently the best strategies to prevent transmission of Nipah virus in abattoirs.

Abattoirs↗

Crossreactivity of SLE autoantibodies with 70 kDa heat shock proteins of Mycobacterium tuberculosis.

Heat shock proteins (hsp) may be involved in the initiation and perpetuation of autoimmune diseases. In order to investigate the possible role of hsp and other intracellular proteins of Mycobacterium tuberculosis in the autoantibody production in SLE, the immuno-crossreactivity of SLE autoantibodies with Mycobacterium tuberculosis sonic extract and hsp-70 kDa was investigated. These proteins showed significant binding with Protein A-Sepharose isolated SLE IgG. Western blotting of hsp-70 with SLE IgG showed strong recognition, suggesting possible involvement of hsp and other intracellular proteins of Mycobacterium tuberculosis in the autoantibody induction in SLE.

Animals↗

Antigen binding characteristics of antibodies against hydroxyl radical modified thymidine monophosphate.

Reactive oxygen species (ROS) are formed in living organisms during normal metabolic reactions as well as under different environmental stresses. In this study, thymidine monophosphate (TMP) was exposed to hydroxyl radical (OH) and challenged in rabbits. TMP and OH-modified TMP were found to be nonimmunogenic. The TMP was linked to bovine serum albumin (BSA) by carbodiimide reaction, and then modified with the OH. The neoantigens, TMP-BSA, and ROS-TMP-BSA conjugates induced highly specific antibodies against immunogens. Induced antibodies exhibited appreciable cross-reactivity with various polynucleotides and nucleic acids. In this respect, the induced antibodies resembled the diverse antigen-binding characteristics of naturally occurring systemic lupus erythematosus (SLE) anti-DNA autoantibodies.

Animals↗

Opioid antagonists and adrenergic agonists for the management of opioid withdrawal.

BACKGROUND: Managed withdrawal, or detoxification, is not in itself a treatment for opioid dependence, but it is a required first step for many forms of longer-term treatment. It may also represent the end point of an extensive period of treatment such as methadone maintenance. As such, managed withdrawal is an essential component of an effective treatment system. This review is one of a series that aims to assess the evidence as to the effectiveness of approaches to managing opioid withdrawal. OBJECTIVES: To assess the effectiveness of interventions involving the combined use of opioid antagonists an adrenergic agonists to manage the acute phase of opioid withdrawal. SEARCH STRATEGY: Multiple electronic databases, including Medline, Embase, Psychlit, Australian Medical Index and Current Contents, were searched using a strategy designed to retrieve references broadly addressing the management of opioid withdrawal. Reference lists of retrieved studies, reviews and conferences were handsearched. SELECTION CRITERIA: Studies that were included: involved administration of an opioid antagonist in combination with an alpha2 adrenergic agonist; had modification of the signs and symptoms of withdrawal as the aim of the intervention; involved participants who had been diagnosed as primarily opioid dependent and were undergoing clinically managed withdrawal; had as their primary focus the acute phase of withdrawal; reported detail of the type and dose of drugs used and the characteristics of study participants; reported information on the nature of withdrawal symptoms experienced, the occurrence of side effects OR rates of completion of withdrawal; and were randomized or quasi-randomized controlled clinical trials or prospective controlled cohort studies comparing the combination of opioid antagonists and adrenergic antagonists with another form of treatment. (The findings of prospective single group studies or case series, and controlled studies without a comparison treatment modality were considered in the narrative component of the review without being identified as included studies). DATA COLLECTION AND ANALYSIS: Potentially relevant studies were assessed for inclusion by one reviewer (LRG). Inclusion decisions were confirmed by consultation between all three reviewers. Included studies were assessed by all reviewers. One reviewer (LRG) undertook data extraction with the process confirmed by consultation between all three reviewers. Three studies compared treatment using an opioid antagonist-clonidine combination with treatment using clonidine only. This review incorporates data tables comparing maximum withdrawal scores and numbers of participants completing withdrawal for these three studies.. The capacity for data analysis is limited by differences in the assessment outcomes in the three studies and the likelihood of allocation bias in one study. Consequently, meta-analysis has not been undertaken to combine the findings of the three studies. MAIN RESULTS: Three studies (four reports) met the criteria for inclusi on in analytical components of this review. Six further studies were identified that managed withdrawal using opioid antagonists in combination with adrenergic agonists, but which did not meet the inclusion criteria (four were single group studies, 2 were controlled studies but did not include a comparison treatment modality). Findings of these studies are considered in narrative components of the review. Naltrexone was the primary opioid antagonist used to induce withdrawal. The most common approach was to administer naltrexone once a day, using an initial dose of 12.5mg, usually on day one or day two of treatment. Doses of clonidine were generally in the range of 01.-0.3mg three times a day. Five studies provided treatment on an outpatient basis, but all studies provided extended care on the day naltrexone was first administered. (ABSTRACT TRUNCATED)

Adrenergic alpha-Agonists↗

Buprenorphine for the management of opioid withdrawal.

BACKGROUND: Managed withdrawal, or detoxification, is not in itself a treatment for opioid dependence, but it is a required first step for many forms of longer-term treatment. It may also represent the end point of an extensive period of treatment such as methadone maintenance. As such, managed withdrawal is an essential component of an effective treatment system. This review is one of a series that aims to assess the evidence as to the effectiveness of the variety of approaches to managing opioid withdrawal. OBJECTIVES: To assess the effectiveness of interventions involving the short-term use of buprenorphine to manage the acute phase of opioid withdrawal. SEARCH STRATEGY: Multiple electronic databases, including Medline, Embase, Psychlit, Australian Medical Index and Current Contents, were searched using a strategy designed to retrieve references broadly addressing the management of opioid withdrawal. Reference lists of retrieved studies, reviews and conference abstracts were handsearched. SELECTION CRITERIA: We included randomised or quasi-randomised controlled clinical trials or prospective controlled cohort studies comparing buprenorphine (treatment 10 days or less) with another form of treatment. Studies were required to provide detailed information on the type and dose of drugs used and the characteristics of patients treated. Studies were also required to provide information on the nature of withdrawal signs and symptoms experienced, the occurrence of adverse effects OR rates of completion of the withdrawal episode. DATA COLLECTION AND ANALYSIS: Potentially relevant studies were assessed for inclusion by one reviewer (LG). Inclusion decisions were confirmed by consultation between reviewers. Included studies were assessed by all reviewers. One reviewer (LG) undertook data extraction with the process confirmed by consultation between all three reviewers. MAIN RESULTS: Five studies met the criteria for inclusion in the review. No data tables are included in this review and no meta-analysis has been undertaken because of differences in treatment regimes and the assessment of outcomes in these studies. Four studies compared buprenorphine with clonidine. All found withdrawal to be less severe in the buprenorphine treatment group. In three of these studies all participants were withdrawing from heroin. Participants in one study were withdrawing from methadone, with doses reduced to 10mg/day prior to treatment with buprenorphine. Three of the studies commented on residual symptoms experienced by participants treated with buprenorphine to manage heroin withdrawal. Aches, restlessness, yawning, mydriasis, tremor, insomnia, nausea and mild anxiety were reported as being experienced by some participants. Rates of completion of withdrawal were able to be calculated for all studies included in the review but the definition of completion varied between studies. Rates ranged from 65% to 100%. None of the studies included in the review reported adverse effects. However, approximately approximately Lintzeris 1999a approximately approximately (a single-group study which therefore did not meet the inclusion criteria) reported 50% of participants withdrawing from heroin experienced headaches, 28% sedation, 21% nausea, 21% constipation, 21% anxiety, 17% dizziness and 17% itchiness during withdrawal. These adverse effects were most common in the first 2-3 days of treatment and then subsided. In four of the five studies treatment was undertaken on an inpatient basis. Only approximately approximately O'Connor 1997 approximately approximately provided outpatient treatment. However, two studies that did not meet the inclusion criteria ( approximately approximately Diamant 1998 approximately approximately and approximately approximately Lintzeris 1999a approximately approximately ) also provided outpatient treatment. The findings of these studies support the feasibility of heroin withdrawal being managed with buprenorphine on an outpatient basis

Acute Disease↗

Glucocorticoids enhance the expression of the basolateral Na+:HCO3- cotransporter in renal proximal tubules.

BACKGROUND: Studies have shown that glucocorticoids enhance HCO3- reabsorption in proximal tubules. Functional and molecular studies indicate that HCO3- reabsorption in proximal tubules is mediated via luminal H(+)-ATPase and Na+/H+ exchanger (NHE-3), and basolateral Na+:HCO3- cotransporter (NBC) acting in series. The purpose of these experiments was to examine the effect of adrenal steroids on NBC-1 and NHE-3 expression and activity in rat renal proximal tubules. METHODS: Rats were injected subcutaneously with dexamethasone (100 mu/day) or deoxycorticosterone acetate (30 mg/kg), potent glucocorticoid, or mineralocorticoid analogues, respectively. Animals were sacrificed after two or four days, and NBC-1 and NHE-3 mRNA expression and activities were measured in cortex and proximal tubules. RESULTS: Northern hybridizations indicated that cortical NBC-1 mRNA expression increased by approximately 92% in rats treated with dexamethasone for four days (N = 6, P < 0.03) but not two days. NHE-3 mRNA expression remained unchanged. NBC and NHE-3 activities were measured as the Na-dependent pHi recovery from an acid load in the presence or absence of HCO3-, respectively, and appropriate inhibitors in proximal tubule suspensions loaded with BCECF. NBC activity increased by approximately 80% in rats treated with dexamethasone for four days (P < 0.01, N = 5) but not two days. NHE-3 activity increased by 34 and 42% in rats treated with dexamethasone for two and four days, respectively (P < 0.05 and P < 0.02 for each group vs. control). Treatment with deoxycorticosterone acetate did not alter NBC-1 expression. CONCLUSION: Glucocorticoids at pharmacologic concentrations enhance the mRNA expression and functional activity of renal proximal tubule NBC-1. Enhanced NBC and NHE-3 activities could result in increased HCO3- reabsorption in proximal tubule and could contribute to the maintenance of metabolic alkalosis in pathophysiologic states associated with increased glucocorticoid production.

Animals↗

The impact of cannabis decriminalisation in Australia and the United States.

This paper summarises and compares the impacts of cannabis decriminalisation measures in two countries. In Australia, an expiation model of decriminalisation succeeded in avoiding the imposition of criminal convictions for many offenders, but substantial numbers of offenders received criminal convictions because of a general "net-widening" in cannabis offence detections, and the failure of many offenders to pay expiation fees and thus avoid criminal prosecution. Despite these problems, the expiation approach has been cost-effective, reducing enforcement costs without leading to increased cannabis use. In the United States, cannabis decriminalisation similarly reduced enforcement costs, with enforcement resources generally redirected toward trafficking and other illicit drugs. There were no increases in cannabis use or substantial problems that could be ascribed to decriminalisation. The implications for other countries are discussed, with particular attention to the importance of implementation issues, monitoring, and evaluation. Although decriminalisation has succeeded in reducing enforcement and other costs without increasing the problems associated with cannabis use, the same impacts would not necessarily result from the legalisation of cannabis or the decriminalisation of other illicit drugs.

Adult↗

The aging paradox: free radical theory of aging.

There are more than 300 theories to explain the aging phenomenon. Many of them originate from the study of changes that accumulate with time. Among all the theories, the free radical theory of aging, postulated first by Harman, is the most popular and widely tested, and is based on the chemical nature and ubiquitous presence of free radicals. This review aims to recapitulate various studies on the role of free radicals in DNA damage-both nuclear as well as mitochondrial-the oxidative stress they impose on cells, the role of antioxidants, the presence of autoantibodies, and their overall impact on the aging process.

Aging↗

A review of biological indicators of illicit drug use, practical considerations and clinical usefulness.

AIMS: To examine a range of biological indicators of illicit drug use, including blood, urine, hair and saliva, addressing both technological and practical issues relating to their application and interpretation. METHODS: The review process involved an examination of key reference texts and literature from the scientific fields of analytical and clinical toxicology. FINDINGS: Urine remains the biological tool of choice for qualitative detection of illicit drug use in a clinical setting, while quantitative accuracy remains strictly the domain of blood. The growing sophistication of laboratory analysis may additionally make possible the routine use of hair sampling which can provide a much longer time frame for assessment. Breath, saliva, sweat or breast milk remain possibilities in the future. CONCLUSIONS: Accurate interpretation of the screening tests within a clinical setting alongside other relevant information remains the key to the usefulness of any test.

Biomarkers↗

Human anti-DNA autoantibodies and induced antibodies against ROS-modified-DNA show similar antigenic binding characteristics.

Alterations in DNA structure by hydroxyl radical modification was characterized by UV spectroscopy, Tm, nuclease S1 digestibility and base modification. In view of indicted role of oxygen free radicals in human diseases, an attempt has been made to precisely compare the antigen binding properties of induced antibodies against hydroxyl radical modified DNA with those of naturally occurring anti-DNA autoantibodies. Antibodies induced against ROS-DNA showed diverse antigen binding characteristics which were comparable with those derived from SLE patients. The immune IgG recognized native DNA, heat denatured DNA, and synthetic polynucleotides in B-/B-like conformations. IgG isolated from SLE sera showed preference for ROS-DNA in competition-inhibition assay. The antigenic diversity of induced antibodies and preference of circulating anti-DNA autoantibodies for ROS-DNA over that of native DNA demonstrates the possible role of modified DNA antigens in the pathogenesis of SLE.

Antibodies, Antinuclear↗

Antigen binding characteristics of experimentally-induced antibodies against hydroxyl radical modified native DNA.

Hydroxyl radical, generated by UV irradiation of hydrogen peroxide caused damage to native calf thymus DNA leading to strand breaks, base modification and decrease in melting temperature. The ROS-DNA was highly immunogenic in goat. The antibody activity was inhibited to the extent of 89% with the immunogen as inhibitor. Antigenic specificity of anti-ROS-DNA antibodies by competition ELISA showed multiple cross-reactivity, recognizing B-, A- and allied conformations. The immune complex formation with native and ROS-DNA was substantiated by band shift assay. A striking observation, is the enhanced recognition of ROS-thymine and ROS-poly(dT) by the induced antibodies. These investigations suggest that ROS might be the plausible candidate for the presentation of unique epitopes on ROS-DNA, in particular of thymine, inducing antibodies cross-reacting with native DNA and play an important role in the pathogenesis of SLE.

Animals↗

A strategy for reducing maternal mortality.

A confidential system of enquiry into maternal mortality was introduced in Malaysia in 1991. The methods used and the findings obtained up to 1994 are reported below and an outline is given of the resulting recommendations and actions.

Adolescent↗

Binding of human anti-DNA autoantibodies to reactive oxygen species modified-DNA and probing oxidative DNA damage in cancer using monoclonal antibody.

The binding of native and reactive oxygen species-modified DNA (ROS-DNA) to circulating antibodies in the serum of patients with various types of cancer has been investigated by competition enzyme-linked immunosorbent assay. Fifteen sera of 35 showed reactivity with native and/or ROS-DNA. Eleven of these showed higher binding to ROS-DNA (36-64% inhibition), whereas 1 showed higher reactivity with native DNA (nDNA) (42% inhibition). Three sera reacted with both native and ROS-DNA almost equally. Oxidative lesions in human genomic DNA were immunochemically detected using an anti-ROS-DNA monoclonal antibody (MAb) probe. Two of 3 DNA isolates from blood of breast cancer patients, 1 of 3 from lung cancer and 1 of 2 each from hepatocellular cancer and cancer of the gallbladder were reactive with the MAb. Higher recognition of ROS-DNA by circulating antibodies and DNA isolated from cancer patients by the MAb indicates increased oxidative stress leading to DNA damage. Our results suggest that ROS modification of DNA probably alters its immunogenicity leading to the generation of antibodies to ROS-DNA, probably by the activation of autoreactive cells. The induced antibodies against modified DNA are cross-reactive to native DNA.

Adult↗