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Biomedical subjects

J Ling

Publications and source records attributed to J Ling.

At least 19 recordsLinked to original sources
PubMed2006

Transcatheter closure of patent ductus arteriosus with severe pulmonary arterial hypertension in adults.

BACKGROUND: Surgical closure of patent ductus arteriosus (PDA) with severe pulmonary arterial hypertension in adults carries higher risk than in children. OBJECTIVES: To investigate the application of self-expandable occluders for transcatheter closure of PDA associated with severe pulmonary arterial hypertension in adults, and the assessment of immediate and short-term results. METHODS: 29 adult patients (6 men, 23 women) underwent attempted transcatheter closure of PDA at a mean (standard deviation (SD)) age of 31.1 (11.4) years (range 18-58 years) and a mean (SD) weight of 54.1 (7.1) kg (range 42-71 kg). On the basis of haemodynamic and clinical data obtained before and after trial occlusion, the final duct occlusion was determined and carried out. Radiographs of the chest, electrocardiograms and echocardiograms were used for follow-up evaluation of the treatment within 1 day, 1 month and 3-6 months after successful closure. RESULTS: 20 of the 29 patients had successful occlusion (group 1), and 9 patients failed (named group 2). In group 1, in which occlusion was successful, mean (SD) pulmonary arterial pressures decreased markedly after trial occlusion: 78 (19.3) mm Hg (range 50-125 mm Hg) before occlusion and 41 (13.8) mm Hg (range 23-77 mm Hg) after occlusion. Systemic arterial oxygen saturation was found to be >90% in 19 patients and <90% in the remaining patient before inhalation of oxygen, and >95% during inhalation of oxygen or after occlusion in all 20 patients. In group 2, the occlusion was not successful, because in two patients the device was not available; another two patients showed worsening of symptoms. The other five patients showed increased pulmonary arterial pressures after trial closure; their mean (SD) pulmonary arterial pressures increased by 10.3 (6) mm Hg (4-16 mm Hg) after trial occlusion, and systemic arterial oxygen saturation was 85.5% (2.6%) (range 82.6-88%) before inhalation of oxygen and 94.7% (1.7%) (range 90.7-99.1%) during inhalation of oxygen. In group 1, the dimensions of the left atrium, left ventricle and pulmonary artery increased considerably in 3-6-months of follow-up compared with those of preocclusion. CONCLUSIONS: Transcatheter closure is an effective treatment for adults with PDA associated with reversible severe pulmonary arterial hypertension. Further research is needed for the evaluation of long-term results.

Adolescent↗
PubMed2006

Dancing hot on Ecstasy: physical activity and thermal comfort ratings are associated with the memory and other psychobiological problems reported by recreational MDMA users.

BACKGROUND: Non-drug factors such as ambient temperature can heighten the adverse effects of MDMA (3,4-methylendioxymethamphetamine) in animals. We assessed whether dancing and feeling hot on Ecstasy would be associated with more psychobiological problems in recreational users. METHODS: In an internet study, 206 unpaid participants (modal age 16-24) reported that they had used recreational Ecstasy/MDMA. They completed a drug use questionnaire, the Prospective Memory Questionnaire (PMQ), questions about dancing and feeling hot when on Ecstasy, and psychobiological problems afterwards. RESULTS: Those who danced 'all the time' when on Ecstasy, reported significantly more PMQ memory problems than the less intensive dancers. Prolonged dancing was also associated with more complaints of depression, memory problems, concentration and organizational difficulties afterwards. Feeling hot when on Ecstasy was associated with poor concentration in the comedown period, and with mood fluctuation and impulsivity off-drug. PMQ long-term problems demonstrated a significant curvilinear relationship with thermal self-ratings; more memory problems were noted by those who felt very hot, and by those who did not feel hot when on Ecstasy. CONCLUSIONS: Non-drug factors such as dancing and feeling hot are associated with the incidence of psychobiological problems reported by recreational Ecstasy/MDMA users.

Adolescent↗
PubMed2005

Differential experiences of the psychobiological sequelae of ecstasy use: quantitative and qualitative data from an internet study.

Previous work provided preliminary evidence that different patterns of use among ecstasy users may impact on perceived side-effects. Participants recruited via an ecstasy-related bulletin board differed in their responses compared to those recruited via other means. The present investigation compares self-reports of psychobiological difficulties among ecstasy users recruited either via a bulletin board or by alternative methods. Qualitative data included reports of any negative or positive changes attributable to ecstasy use and reasons for cessation of use. An Internet-based design was utilized and 209 volunteers completed the study, 117 of whom were recruited via a bulletin board devoted to discussion of ecstasy. Psychobiological difficulties attributable to ecstasy use varied, with mood fluctuation the most common. Differences between the two groups in the extent to which these problems were reported was found. Bulletin board recruits were less likely to report anxiety or poor concentration, but more likely to report tremors/twitches. For the whole sample, lifetime use was associated more with psychobiologial problems, although this pattern was stronger and more pervasive for the non-bulletin board participants. Bulletin board recruits were more aware of possible negative psychological effects and were more likely to report adopting harm reduction strategies. From the qualitative data three negative consequences of use were identified, the most common of which was "psychological problems". In support of the quantitative findings the likelihood of reporting psychological problems increased with lifetime exposure to ecstasy in both recruitment conditions but interestingly this did not appear to impact on reasons for cessation of use. Participants also reported a number of effects that they regarded as beneficial. Future research should also take these aspects of use into account.

Adolescent↗
PubMed2004

Self-rated everyday and prospective memory abilities of cigarette smokers and non-smokers: a web-based study.

The present study examined self-ratings of two aspects of everyday memory performance: long-term prospective memory-measured by the prospective memory questionnaire (PMQ), and everyday memory-measured by the everyday memory questionnaire (EMQ). Use of other substances was also measured and used as covariates in the study. To ensure confidentiality and to expand the numbers used in previous studies, an Internet study was carried out and data from 763 participants was gathered. After controlling for other drug use and strategy use, the data from the PMQ revealed that smokers reported a greater number of long-term prospective memory errors than non-smokers. There were also differences between light and heavier smokers in long-term prospective memory, suggesting that nicotine may have a dose-dependent impact upon long-term prospective memory performance. There was also a significant ANOVA group effect on the EMQ, although the trend for more memory errors amongst the heavier smokers was statistically only borderline (p=.057). These findings suggest there are selective memory deficits associated with smoking and that long-term prospective memory deficits should be added to the growing list of problems associated with cigarette use.

Adult↗
PubMed2003

Effects of alcohol on subjective ratings of prospective and everyday memory deficits.

BACKGROUND: Research has shown that heavy alcohol use has a detrimental effect on retrospective memory. Less is known about the effect of alcohol on everyday memory. METHODS: This study examined self-ratings of two aspects of memory performance: prospective memory (for example, forgetting to pass on a message) and everyday memory (measured by cognitive failures, such as telling someone a joke that you have told them before). To ensure anonymity and expand on the numbers of participants used in previous studies, data were collected by using the Internet. Data from 763 participants remained after data screening. RESULTS: After controlling for other drug and strategy use, there was clear evidence that differential use of alcohol was associated with impairments in the long-term aspect of prospective memory and with an increased number of cognitive failures. CONCLUSIONS: These results support and extend the findings of previous research: our findings are consistent with the idea that heavy use of alcohol does have a significant and negative effect on everyday cognitive performance. Possible causes of these impairments are discussed.

Adult↗
PubMed2003

Patterns of drug use and the influence of gender on self-reports of memory ability in ecstasy users: a web-based study.

Research indicates that the use of recreational drugs, including MDMA ('ecstasy') can result in impairments in cognitive functioning. Recent evidence, based on accounts of 'on drug' effects and cortical binding ratios suggests that women may be more susceptible to the effects of MDMA; however, no research has explored whether there are differences in the long-term behavioural sequelae of the drug between men and women. In addition, little is known about the profile of functioning of the 'typical' user. The present investigation accessed a large sample of recreational drug users, using the Internet, to obtain self-reports of memory functioning with a view to exploring any differences in self-reported ability amongst male and female users, and the level of difficulty reported by the 'typical' ecstasy user. A web site (www.drugresearch.org.uk) was developed and used for data collection. Prospective memory ability was assessed using the Prospective Memory Questionnaire. Self-report of day-to-day memory performance was investigated using the Everyday Memory Questionnaire. The UEL Drug Questionnaire assessed the use of other substances. The number of mistakes made while completing the questionnaires was also taken as an objective measure of performance errors. Findings, based on datasets submitted from 763 respondents, indicate no differences in self-reports of functioning between male and female participants. An overall dissociation between the effects of cannabis and ecstasy on self-reported memory functioning and on the likelihood of making an error during the completion of the questionnaire was found. Typical ecstasy users were found to report significantly more difficulties in long-term prospective memory and to make more completion errors than users of other substances and drug naive controls. Whilst taking into account the fact that participants were recruited via the World Wide Web and that a number of stringent exclusion criteria were applied to the data, a number of conclusions can be drawn. Recreational drug users perceive their memory ability to be impaired compared to non-users. The type of memory difficulties reported varies depending upon the drug of choice. These difficulties are exacerbated in ecstasy users. Individuals reporting average levels of use of ecstasy are more likely to report memory problems than non-ecstasy drug users or drug free individuals. The deleterious effects of ecstasy are therefore not restricted to heavy or chronic users. No gender differences were detected, suggesting that there may be a dissociation between cognitive impairment and cortical binding worthy of further exploration.

Amphetamine-Related Disorders↗
PubMed2002

Is there a dose response relationship for clodronate in the treatment of tumour induced hypercalcaemia?

Eighty-six patients with tumour induced hypercalcaemia were randomised to 600, 900, 1200 or 1500 mg of intravenous clodronate, according to post hydration serum calcium levels. Sixty-seven were evaluable for response. The overall response rate was 49.3% (95% CI: 36.8-61.8) with no significant difference in response rates, i.e. achievement of normocalcaemia at days 6-9 (corrected serum calcium < or =2.6 mmol l(-1)) across all groups.

Adult↗
PubMed2002

Ecstasy/MDMA attributed problems reported by novice, moderate and heavy recreational users.

RATIONALE: The recreational use of MDMA/Ecstasy (3,4-methylenedioxymethamphetamine) is associated with many psychobiological problems, but there is a paucity of data on how these relate to the level of past use. OBJECTIVES: to assess the incidence of Ecstasy-attributed problems as reported by novice, moderate and heavy users. METHODS: 763 unpaid volunteers took part in a WWW study of recreational drug use. This report is based on the 282 Ecstasy users from that sample, who comprised 109 novice users (1-9 occasions), 136 moderate users (10-99 occasions), and 36 heavy users (+100 occasions). Yes/no responses were automatically recorded to a series of questions covering psychobiological problems experienced when drug-free, which were attributed by the respondents to their Ecstasy use. RESULTS: Depression, memory problems, anxiety, mood fluctuation, poor concentration, infections, tremors/twitches and weight loss, were all significantly associated with the extent of Ecstasy use. Thus memory problems attributed to Ecstasy were reported by 19% of novice users, 52% of heavy users and 73% of heavy users (chi-square 42.74, df=2, p<0.001); many of the other variables showed similar trends. CONCLUSIONS: The incidence of problems attributed to Ecstasy use, is directly related to the number of occasions it has been used.

Anxiety↗
PubMed2001

Randomized, parallel placebo-controlled trial of primaquine for malaria prophylaxis in Papua, Indonesia.

Malaria causes illness or death in unprotected travelers. Primaquine prevents malaria by attacking liver-stage parasites, a property distinguishing it from most chemoprophylactics and obviating 4-week postexposure dosing. A daily adult regimen of 30 mg primaquine prevented malaria caused by Plasmodium falciparum and P. vivax for 20 weeks in 95 of 97 glucose-6-phosphate dehydrogenase (G6PD)-normal Javanese transmigrants in Papua, Indonesia. In comparison, 37 of 149 subjects taking placebo in a parallel trial became parasitemic. The protective efficacy of primaquine against malaria was 93% (95% confidence interval [CI] 71%-98%); against P. falciparum it was 88% (95% CI 48%-97%), and >92% for P. vivax (95% CI >37%-99%). Primaquine was as well tolerated as placebo. Mild methemoglobinemia (mean of 3.4%) returned to normal within 2 weeks. Blood chemistry and hematological parameters revealed no evidence of toxicity. Good safety, tolerance, and efficacy, along with key advantages in dosing requirements, make primaquine an excellent drug for preventing malaria in nonpregnant, G6PD-normal travelers.

Adolescent↗
PubMed2001

The pharmacology of bimatoprost (Lumigan).

Bimatoprost (Lumigan) is a pharmacologically unique and highly efficacious ocular hypotensive agent. It appears to mimic the activity of a newly discovered family of fatty acid amides, termed prostamides. One biosynthetic route to the prostamides involves anandamide as the precursor. Bimatoprost pharmacology has been extensively characterized by binding and functional studies at more than 100 drug targets, which comprise a diverse variety of receptors, ion channels, and transporters. Bimatoprost exhibited no meaningful activity at receptors known to include antiglaucoma drug targets as follows: adenosine (A(1-3)), adrenergic (alpha(1), alpha(2), beta(1), beta(2)), cannabinoid (CB(1), CB(2)), dopamine (D(1-5)), muscarinic (M(1-5)), prostanoid (DP, EP(1-4), FP, IP, TP), and serotonin (5HT(1-7)). Bimatoprost does, however, exhibit potent inherent pharmacological activity in the feline iris sphincter preparation, which is prostamide-sensitive. Bimatoprost also resembles the prostamides in that it is a potent and highly efficacious ocular hypotensive agent. A single dose of bimatoprost markedly reduces intraocular pressure in dogs and laser-induced ocular hypertensive monkeys. Decreases in intraocular pressure are well maintained for at least 24 hr post-dose. Human studies have demonstrated that systemic exposure to bimatoprost is low and that accumulation does not occur. The sclera is the preferred route of accession to the eye. The high scleral permeability coefficient Papp is a likely contributing factor to the rapid onset and long-acting ocular hypotensive profile of bimatoprost.

Amides↗
PubMed2001

Depletion of substance P from rat primary sensory neurons by ATP, an implication of P2X receptor-mediated release of substance P.

Effects of ATP on substance P immunoreactivity were examined in cultured dorsal root ganglion neurons. We found that treatment of dorsal root ganglion neurons with ATP significantly depleted substance P immunoreactivity on the neurites and somata of the neurons. The effects of ATP were significantly inhibited by the purinergic P2 receptor antagonists suramin (30 microM) and pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (10 microM). We also showed that ATP-induced depletion of substance P immunoreactivity from dorsal root ganglion neurons depended on the entry of Ca(2+). In a spinal cord slice preparation, we also found the internalization of neurokinin-1/substance P receptors in many dorsal horn neurons following the application of ATP or alpha,beta-methylene-ATP. Together these results indicate that activation of P2X receptors may result in release of substance P from primary afferent neurons.

Adenosine Triphosphate↗
PubMed2001

A phase II study to establish the efficacy and toxicity of sodium valproate in patients with cancer-related neuropathic pain.

The efficacy and toxicity of sodium valproate for cancer-related neuropathic pain was evaluated in a phase II study at this cancer center. Twenty-five patients entered the study over a 13 month period. Pain was assessed using a pain scale based on the Brief Pain Inventory at days 0, 8 and 15. Nineteen patients completed the two week study period, one patient discontinued treatment because of toxicity, and five discontinued because of progressive disease. The most frequently observed side effects were drowsiness, unsteadiness, nausea, and decreased appetite. Response was defined as a decrease in pain score in the absence of increased need for analgesic medication. The response rate for average pain at day 15 in assessable patients was 55.6% (30.8-78.5%, 95% CI), but response rates varied considerably depending on the mode of analysis. Baseline efficacy data have been gained on which to base future comparative studies against antidepressants.

Adult↗
PubMed2001

The impact of Eysenck's extraversion-introversion personality dimension on prospective memory.

Prospective memory (PM) is memory for future events. PM is a developing area of research (e.g., Brandimonte, Einstein & McDaniel, 1996) with recent work linking personality types and their utilisation of PM (Goschke & Kuhl, 1996; Searleman, 1996). The present study compared 28 extraverts and 28 introverts on their short- and long-term prospective memory using the Prospective Memory Scale developed by Hannon, Adams, Harrington, Fries-Dias & Gibson (1995). The main finding was that extraverts reported significantly fewer errors on short- and long-term PM than introverts, and this difference could not be explained in terms of the number of strategies used to support prospective remembering. These findings are discussed in relation to differences between the personality types.

Adolescent↗
PubMed2001

A prospective survey of the use of dexamethasone on a palliative care unit.

One hundred and six consecutive patients started on glucocorticosteroids (steroids) according to a defined prescription policy were surveyed each week to document the indications for use, any beneficial effect, any toxicity incurred and the reason for stopping. All patients had advanced malignant disease and survived for a median of 40.5 days (range 1-398+ days) from the start of steroid treatment. Fifty-seven per cent of patients completed three or more assessments. The most common specific indications for starting steroids were spinal cord compression, cerebral metastases, lymphangitis carcinomatosa and intestinal obstruction. The most common non-specific indications were anorexia, nausea, low mood, pain and vomiting. The median duration of steroid use was 21.5 days (range 1-89 days). The most common reason for the discontinuation of steroids was death or deteriorating condition. Symptom scores improved at some stage for the majority of patients started on steroids for anorexia, nausea, pain, low mood, vomiting and weakness but not in patients complaining of dyspnoea or poor mobility. The most common side-effects that were most probably attributable to steroid therapy were oral candidosis and proximal myopathy. The benefits of steroids when used according to defined guidelines were thought to outweigh toxicity.

Anti-Inflammatory Agents↗
PubMed2001

Developmental and thermal regulation of the maize heat shock protein, HSP101.

The plant heat stress protein, Hsp101, and the yeast ortholog, Hsp104, are required to confer thermotolerance in plants and yeast (Saccharomyces cerevisiae), respectively. In addition to its function during stress, Hsp101 is developmentally regulated in plants although its function during development is not known. To determine how the expression of Hsp101 is regulated in cereals, we investigated the Hsp101 expression profile in developing maize (Zea mays). Hsp101 protein was most abundant in the developing tassel, ear, silks, endosperm, and embryo. It was less abundant in the vegetative and floral meristematic regions and was present at only a low level in the anthers and tassel at anthesis, mature pollen, roots, and leaves. As expected, heat treatment resulted in an increase in the level of Hsp101 protein in several organs. In expanding foliar leaves, husk leaves, the tassel at the premeiosis stage of development, or pre-anthesis anthers, however, the heat-mediated increase in protein was not accompanied by an equivalent increase in mRNA. In contrast, the level of Hsp101 transcript increased in the tassel at anthesis following a heat stress without an increase in Hsp101 protein. In other organs such as the vegetative and floral meristematic regions, fully expanded foliar leaves, the young ear, and roots, the heat-induced increase in Hsp101 protein was accompanied by a corresponding increase in Hsp101 transcript level. However, anthers at anthesis, mature pollen, developing endosperm, and embryos largely failed to mount a heat stress response at the level of Hsp101 protein or mRNA, indicating that Hsp101 expression is not heat inducible in these organs. In situ RNA localization analysis revealed that Hsp101 mRNA accumulated in the subaleurone and aleurone of developing kernels and was highest in the root cap meristem and quiescent center of heat-stressed roots. These data suggest an organ-specific control of Hsp101 expression during development and following a heat stress through mechanisms that may include posttranscriptional regulation.

Amino Acid Sequence↗
PubMed2001

[Recombinant Salmonella typhimurium anticaries vaccine. II. Construction and confirmation of expressing plasmid carrying a region of S. mutans pac gene].

OBJECTIVE: The objective of this study is to construct prokaryotic expressing plasmids carrying A region of S. mutans pac gene. METHODS: The A region of pac gene was amplified by using PCR from plasmid pPC41 containing S. mutans surface protein pac gene. The new expression plasmid was constructed by using A region of pac gene and expressing plasmids pET17-b and directed cloning technique. The recombinant plasmid was identified by agarose gel electrophoresis after it was cut by using BamHI and EcoRV. RESULTS: The expressing plasmid carrying pac gene A region was acquired. CONCLUSION: The recombinant plasmid provides useful experimental materials for further research work.

Dental Caries↗