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D Wong

Publications and source records attributed to D Wong.

At least 37 records · Page 2Linked to original sources
PubMed2005

A pilot study on the use of a perfluorohexyloctane/silicone oil solution as a heavier than water internal tamponade agent.

AIMS: To report a prospective two centred non-comparative interventional pilot study of a solution of perfluorohexyloctane and silicone oil (Densiron-68) as a heavier than water internal tamponade. METHODS: 42 consecutive patients were recruited. The indications include proliferative vitreoretinopathy, retinal detachments arising from inferior retinal breaks, and inability to posture. RESULTS: The success rate with one operation using Densiron was 81% and with further surgery 93%. At the end of the study all tamponade agents were removed in 90% of patients. Visual acuity improved from mean logMAR of 1.41 (SD 0.64) to 0.94 (SD 0.57), p = 0.001. There was little evidence of dispersion and excessive inflammation. CONCLUSION: This new tamponade agent is being compared to conventional silicone oil in a prospective international randomised trial.

Adult↗
PubMed2004

Amphetamines for schizophrenia.

BACKGROUND: It is estimated that between 10% and 65% of people with schizophrenia use illicit drugs such as amphetamines. This group have an increased rate of hospitalisation, homelessness, unemployment and suicide compared with those with schizophrenia who do not abuse drugs. OBJECTIVES: To evaluate the effects of amphetamines for people with schizophrenia in terms of clinically meaningful outcomes, cognitive functioning and physiological tests. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group's Register (February 2002). SELECTION CRITERIA: We included all randomised controlled trials investigating the effects of amphetamines on people with schizophrenia, compared with a placebo intervention. DATA COLLECTION AND ANALYSIS: Working independently, we selected and critically appraised studies, extracted data and analysed on an intention-to-treat basis. Where possible and appropriate we calculated risk ratios (RR) and their 95% confidence intervals (CI), with the number needed to treat (NNT). For continuous data we calculated Weighted Mean Differences (WMD). MAIN RESULTS: We included four short studies with a total of 83 participants. Data were few and poorly reported. The results indicated a reduction of negative symptoms for people allocated to amphetamines (n = 16, 1 RCT, WMD -3 CI -5.02 to -0.98). No such effect was found for positive symptom change (n = 16, 1 RCT, WMD 0 CI -4.46 to 4.46). Compared with placebo, amphetamines significantly increased metabolism in the left and right cerebellum (n = 23, 1 RCT, WMD 0.12 CI 0.06 to 0.18; n = 23 1 RCT, WMD 0.12 CI 0.06 to 0.18) and left striatum (n = 23, 1 RCT, WMD 0.14 CI 0.00 to 0.28) and also significantly decreased metabolism in the left dorsolateral prefrontal cortex (n = 23, 1 RCT, WMD -0.09 CI -0.17 to -0.01). REVIEWERS' CONCLUSIONS: Understandably amphetamines are rarely formally evaluated in randomised studies and therefore unpublished work in this area is likely to exist. Addition of more studies may clarify reasons why people with schizophrenia persist in taking these harmful stimulants.

Amphetamine-Related Disorders↗
PubMed2004

Depot bromperidol decanoate for schizophrenia.

BACKGROUND: Antipsychotic drugs are the mainstay treatment for schizophrenia. Long-acting depot injections of drugs such as bromperidol decanoate are extensively used as a means of long-term maintenance treatment. OBJECTIVES: To assess the effects of depot bromperidol versus placebo, oral antipsychotics and other depot antipsychotic preparations for people with schizophrenia in terms of clinical, social and economic outcomes. SEARCH STRATEGY: Relevant trials were identified by searching Biological Abstracts (1982-1999), Cochrane Library (Issue 2, 1999), Cochrane Schizophrenia Group's Register (May 1999), EMBASE (1980-1999), MEDLINE (1966-1999) and PsycLIT (1974-1999). References of all identified trials were inspected and Janssen-Cilag was contacted in order to identify more trials. An update search was undertaken in October 2003. The Schizophrenia Groups trials register is based on regular searches of BIOSIS Inside; CENTRAL; CINAHL; EMBASE; MEDLINE and PsycINFO; the hand searching of relevant journals and conference proceedings, and searches of several key grey literature sources. A full description is given in the Group's module. SELECTION CRITERIA: All randomised trials focusing on people with schizophrenia where depot bromperidol, oral antipsychotics or other depot preparations were sought. Primary outcomes were death, clinically significant change in global function, mental state, relapse, hospital admission, adverse effects and acceptability of treatment. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers and cross-checked. Fixed effects relative risks (RR) and 95% confidence intervals (CI) were calculated for dichotomous data. Weighted or standardised means were calculated for continuous data. Where possible, the number needed to treat statistic (NNT) was calculated. Analysis was by intention-to-treat. MAIN RESULTS: Four controlled clinical trials were included (total n=117). We identified a single small study of six months duration comparing bromperidol decanoate with placebo injection. Similar numbers left the study before completion (n=20, 1 RCT, RR 0.4 CI 0.1 to 1.6) and there was no clear differences between bromperidol decanoate and placebo for a list of adverse effects (n=20, 1 RCT, RR akathisia 2.0 CI 0.21 to 18.69, RR increased weight 3.0 CI 0.14 to 65.9, RR tremor 0.33 CI 0.04 to 2.69). When bromperidol decanoate was compared with fluphenazine depot we found no important change on global outcome (n=30, RR no clinical important improvement 1.50 CI 0.29 to 7.73). People allocated to fluphenazine decanoate and haloperidol decanoate had less relapses than those given bromperidol decanoate (n=77, RR 3.92 Cl 1.05 to 14.60, NNH 6 CI 2 to 341). People allocated bromperidol decanoate required additional antipsychotic medication somewhat more frequently than those taking fluphenazine decanoate and haloperidol decanoate but the results did not reach conventional levels of statistical significance (n=77, 2 RCTs, RR 1.72 CI 0.7 to 4.2). The use of benzodiazepine drugs was very similar in both groups (n=77, 2 RCTs, RR 1.08 CI 0.68 to 1.70). People left the bromperidol decanoate group with the same frequency as those allocated other depots (n=97, 3 RCTs, RR 1.92 CI 0.8 to 4.6). Anticholinergic adverse effects were equally common between bromperidol and other depots (n=47, RR 3.13 CI 0.7 to 14.0) and additional anticholinergic medication was needed with equal frequency in both depot groups, although results did tend to favour the bromperidol decanoate group (n=97, 3 RCTs, RR 0.80 CI 0.64 to 1.01). The incidence of movement disorders was similar in both depot groups (n=77, 2 RCTs, RR 0.74 CI 0.47 to 1.17). REVIEWERS' CONCLUSIONS: Currently, minimal poorly reported trial data suggests that bromperidol decanoate may be better than placebo injection but less valuable than fluphenazine or haloperidol decanoate. If bromperidol decanoate is available it may be a viable choice, especially when there are reasons not to use fluphenazine or haloperidol decanoate. Well-conducted and reported randomised trials are needed to inform practice in Belgium, Germany, Italy and the Netherlands.

Antipsychotic Agents↗
PubMed2004

Impact of clay minerals on sulfate-reducing activity in aquifers.

Previous studies have shown that sulfate-reduction activity occurs in a heterogeneous manner throughout the terrestrial subsurface. Low-activity regions are often observed in the presence of clay minerals. Here we report that clays inhibit sulfate reduction activity in sediments and in a pure culture of Desulfovibrio vulgaris. Clay minerals including bentonite and kaolinite inhibited sulfate reduction by 70-90% in sediments. Intact clays and clay colloids or soluble components, capable of passing through a 0.2-microm filter, were also inhibitory to sulfate-reducing bacteria. Other adsorbent materials, including anion or cation exchangers and a zeolite, did not inhibit sulfate reduction in sediments, suggesting that the effect of clays was not due to their cation-exchange capacity. We observed a strong correlation between the Al2O3 content of clays and their relative ability to inhibit sulfate reduction in sediments (r2 = 0.82). This suggested that inhibition might be a direct effect of Al3+ (aq) on the bacteria. We then tested pure aluminum oxide (Al2O3) and showed it to act in a similar manner to clay. As dissolved aluminum is known to be toxic to a variety of organisms at low concentrations, our results suggest that the effects of clay on sulfate-reducing bacteria may be directly due to aluminum. Thus, our experiments provide an explanation for the lack of sulfate-reduction activity in clay-rich regions and presents a mechanism for the effect.

Aluminum Oxide↗
PubMed2004

Rolling over in infants: age, ethnicity, and cultural differences.

A preliminary cross-sectional study of 72 Hong Kong Chinese infants suggested that these infants learn to roll from supine-to-prone before rolling from prone-to-supine i.e. the opposite to teaching in most western texts. Three-hundred and sixty mothers were recruited postpartum and asked to record, on a chart, information related to the developmental milestone of rolling over for their infants (49% male) during the next 9 months. Telephone reminders were given at 4 and 8 months and, by the end of the study, information had been obtained from 240 mothers (67% of original sample, 51% male infants). Mean ages of rolling over were 5.1 months (SD1.5) for supine-to-prone and 5.7 months (SD1.3) for prone-to-supine. Age of rolling over from supine-to-prone was not influenced by usual sleep position, infant's sex, mother's intention to breastfeed infant, number of siblings, marital status, main daytime caregiver, or feeding method over 9 months. Hong Kong Chinese infants roll from supine-to-prone before they roll from prone-to-supine.

Adult↗
PubMed2004

Exfoliative cytology as a diagnostic test for basal cell carcinoma: a meta-analysis.

BACKGROUND: Exfoliative cytology is only occasionally used in clinical practice to diagnose basal cell carcinoma (BCC). OBJECTIVES: To systematically review the literature examining exfoliative cytology as a diagnostic tool for BCC and to meta-analytically summarize the accuracy of this test. METHODS: Diagnostic test meta-analysis. A computerized database search was made of MEDLINE (1966-2000) and EMBASE (1950-2000) using appropriately indexed terms. Hand searches of relevant journals were made. Bibliographies of relevant articles were further explored. Histopathology was used as the reference standard. A summary receiver-operating characteristic curve analysis was performed using the statistical package Meta-Test version 0.6 (J. Lau, New England Medical Center, Boston, MA, U.S.A., 1997). RESULTS: Eight primary studies (seven English language and one Italian language) fulfilled the inclusion criteria. The pooled sample included 1261 BCCs. These studies varied greatly in methodological quality and were, in general, poor. A meta-analysis showed the pooled sensitivity to be high at 97%[95% confidence interval (CI) 94-99]. Consequently, only 3% of BCCs included were misdiagnosed as non-BCC by cytology. The corresponding pooled specificity was 86% (95% CI 80-91). CONCLUSIONS: Exfoliative cytology probably has a high diagnostic accuracy for BCC. However, large, better designed and better reported studies are needed to ascertain the true accuracy of this technique. In the interim, this test should be considered in specific subgroups of patients in whom even a 2-mm punch biopsy may be considered inappropriate, e.g. a cosmetically sensitive site in a young person. Similarly, it should be considered when a BCC is to be treated without a diagnostic biopsy being taken, e.g. with cryotherapy.

Basal Cell Carcinoma↗
PubMed2004

Case selection in macular relocation surgery for age related macular degeneration.

BACKGROUND: To date there has been no randomised controlled trial demonstrating the safety and efficacy of macular relocation surgery (MRS) for age related macular degeneration (AMD). Vision can be improved in some patients and made worse in others despite successful surgery or because of complications. PURPOSE: To determine which patients would benefit from MRS. METHODS: Twenty nine patients with exudative AMD took part in a prospective, non-comparative, interventional study. Macular relocation surgery involved phacoemulsification, vitrectomy, 360 degrees retinotomy, excision of choroidal neovascular membrane, and macular relocation using an infusion of 5-fluorouracil and low molecular weight heparin as adjuvant to prevent proliferative vitreoretinopathy. Patients underwent protocol refraction preoperatively and six-monthly postoperatively by designated optometrists. Preoperative fundus fluorescein angiograms were read by masked observers and the lesions were classified according to a set protocol. The main outcome measures were visual improvement, final vision of better than 20/400, reading speed, critical print size. Logistic and multiple stepwise linear regressions were used to identify independent factors which predicted the main outcomes. RESULTS: Preoperative visual acuity (20/120 or worse) and lesion type (predominantly classic or submacular haemorrhage) were significantly associated with visual improvement (coefficient of regression B = 26.8, p<0.001 and B = 14.9 with p = 0.045 respectively). There were no significant independent factors which predicted a final distance logMAR visual acuity of 1.3 (20/400) or any arbitrary definition of blindness. CONCLUSIONS: The study showed that it was possible to select cases that were more likely to experience an improvement in vision following MRS.

Aged↗
PubMed2004

Tamponade efficiency of perfluorohexyloctane and silicone oil solutions in a model eye chamber.

BACKGROUND/AIM: As no single tamponade agent yet fulfils all the requirements of a long term inferior tamponade, attempts have been made to mix tamponade materials. This study investigated perfluorohexyloctane (F(6)H(8)) and silicone oil solutions designed to take advantage of the high specific gravity and interfacial tension of the F(6)H(8) and the high viscosity of silicone oil. METHODS: Solutions of three different densities were examined (1.01, 1.03 and 1.06 g/cm(3)) inside transparent chambers made of surface modified poly(methylmethacrylate) (PMMA). RESULTS: Compared to F(6)H(8), the solutions had poorer contact with hydrophilic surface of the chambers. The higher the specific gravity of the solution, the better was the contact. The solution with a specific gravity 1.01 g/cm(3) is probably of no use clinically. CONCLUSION: The model eye chamber made of surface modified PMMA is an efficient way of screening and choosing solutions with promising physical properties. Solutions of silicone oil with F(6)H(8) in other proportions or with other semifluorinated alkanes may be of interest.

Chemical Phenomena↗
PubMed2003

Characterization of microbial activities and U reduction in a shallow aquifer contaminated by uranium mill tailings.

A characterization of the Shiprock, NM, uranium mill tailing site focused on the geochemical and microbiological factors governing in-situ uranium-redox reactions. Groundwater and aqueous extracts of sediment samples contained a wide concentration range of sulfate, nitrate, and U(VI) with median values of 21.2 mM, 16.1 micro M, and 2.7 micro M, respectively. Iron(III) was not detected in groundwater, but a median value of 0.3 mM in sediment extracts was measured. Bacterial diversity down gradient from the disposal pile reflected the predominant geochemistry with relatively high numbers of sulfate- and nitrate-reducing microorganisms, and smaller numbers of acetogenic, methanogenic, nitrate-dependent Fe(II)-oxidizing, Fe(III)-reducing, and sulfide-oxidizing bacteria. In aquifer slurry incubations, nitrate reduction was always preferred and had a negative impact on sulfate-, Fe(III)-, and U-reduction rates. We also found that sulfate-reduction rates decreased sharply in the presence of clay, while Fe(III)-reduction increased with no clear impact on U reduction. In the absence of clay, iron and sulfate reduction correlated with concentrations of Fe(III) and sulfate, respectively. Rates of U(VI) loss did not correlate with the concentration of any electron acceptor. With the exception of Fe(III), electron donor amendment was largely unsuccessful in stimulating electron acceptor loss over a 2-week incubation period, suggesting that endogenous forms of organic matter were sufficient to support microbial activity. Our findings suggest that efforts to accelerate biological U reduction should initially focus on stimulating nitrate removal.

Bacteria↗
PubMed2003

Pancreatic cancer: preliminary experience with sodium iodide fluorodeoxyglucose positron emission tomography in Australia.

Previous studies of fluorodeoxyglucose positron emission tomography (FDG-PET) in pancreatic cancer have used Bismuth Germinate detector systems. This preliminary Australian study aims to confirm the accuracy of FDG-PET in pancreatic cancer using a dedicated sodium iodide (NaI) PET system. Fifteen consecutive patients underwent FDG-PET using a GE QUEST dedicated NaI PET scanner. The indications were the characterization of a pancreatic mass seen on CT or ultrasonographic imaging (nine cases), diagnosis or exclusion of recurrent disease following surgery and adjuvant therapy (four cases) and presurgical staging of primary pancreatic cancer (two cases). The final diagnosis was determined from histology or, when no histology was available, by radiological and clinical follow up. The FDG-PET accurately characterized eight out of nine pancreatic masses (seven were true negative, one was true positive and one was false positive). Of the four cases performed to determine recurrent disease, three were accurately diagnosed (two true negatives and one true positive). In the fourth case, PET accurately detected a liver metastasis but did not detect the local recurrence. Results in the two cases where PET was performed for preoperative staging comprised one true positive and one false negative. Sodium iodide FDG-PET is useful in the diagnosis of pancreatic cancer, particularly in the presence of a previously detected mass.

Fluorodeoxyglucose F18↗
PubMed2003

Trypan blue staining of internal limiting membrane and epiretinal membrane during vitrectomy: visual results and histopathological findings.

AIMS: To report on the use of trypan blue (TB) 0.06% for staining the internal limiting membrane (ILM) and epiretinal membrane (ERM) during vitrectomy and report on their histology. METHOD: 14 consecutive patients with idiopathic macular hole or macular pucker (seven patients each) were prospectively recruited for ILM or ERM peel respectively. After pars plana vitrectomy and induction of posterior vitreous detachment, 0.5 ml TB 0.06% in phosphate buffered saline (VisonBlue) was injected over the posterior pole in an air filled eye and left for 2 minutes. The stained tissue was peeled with intraocular forceps. Specimens were evaluated using histochemical and immunohistochemical methods. RESULTS: The average follow up was 4.4 months. Internal limiting membranes and epiretinal membranes were stained satisfactorily in all cases and removed successfully. Eight patients (57%) had improvement of 2 or more Snellen lines. All seven macular holes closed. In the ERM cases, no residual membranes were observed clinically, at the latest follow up. No complications relating to the use of the dye were encountered intraoperatively or postoperatively. Of the 14 procedures, nine (four macular hole and five macular pucker) yielded sufficient tissue for histopathological evaluation. Histological and immunohistological assessment revealed that the morphology of these specimens was similar to that observed in macular hole ILM and macular pucker ERM removed without the aid of dye. CONCLUSION: TB staining facilitated the identification and delineation of ILM and ERM removal during the surgical management of macular holes and macular pucker. The visual outcome of this series and the specimens removed suggest they are no different from those without TB staining. Its use in posterior segment appears to be safe but further studies are required to investigate its long term safety.

Adult↗
PubMed2003

Macular relocation after photodynamic therapy for recurrent choroidal neovascular membrane: visual results and histopathological findings.

BACKGROUND/AIMS: The findings in a patient treated with photodynamic therapy (PDT) followed by macular relocation surgery (MRS) are presented. METHODS: Histopathological evaluation of the choroidal neovascular membrane (CNV) specimen including immunohistochemical assessment. RESULTS: Microscopy revealed one CNV area that was richly vascular with attached retinal pigment epithelial cell monolayer and another area that was made up of densely collagenous avascular tissue with adherent fragments of Bruch's membrane and glial elements. CONCLUSION: The findings suggest that the PDT treated part of the CNV may have been adherent to the neuroretina and may have contributed to the formation of the macular hole. Caution is advised when considering MRS for CNV previously treated PDT.

Aged↗
PubMed2002

Solitary pulmonary nodules: accuracy and cost-effectiveness of sodium iodide FDG-PET using Australian data.

This study uses Australian data to confirm the accuracy of dedicated sodium iodide (NaI) fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in evaluating indeterminate solitary pulmonary nodules (SPNs) and to determine the conditions under which PET could play a cost-effective role in this evaluation. Ninety-two patients from two Australian hospitals in different states underwent FDG-PET for evaluation of an SPN. Observed values for prior probability of malignancy and diagnostic accuracy of PET were applied to previously published decision tree models using published Australian health care costs. The accuracy of FDG-PET was 93% with a sensitivity of 92% and a specificity of 95%. The prior probability of malignancy (0.54), PET sensitivity and PET specificity indicated cost savings per patient of up to EUR 455 (Adollars 774) based on a PET cost of EUR 706 (Adollars 1,200). PET would remain cost-effective for levels of prior probability up to 0.8-0.9 and a PET cost of EUR 736-1,161 (Adollars 1,252-Adollars 1,974). It is concluded that NaI PET is accurate, cost saving and cost-effective for the characterisation of indeterminate pulmonary nodules in Australia. Comparison with previous reports from the United States confirms that FDG-PET can remain cost-effective despite population differences in medical costs, disease prevalence and PET diagnostic performance.

Aged↗