Modified Photodynamic Therapy Treatment of Central Serous Chorioretinopathy.

PURPOSE: Central serous chorioretinopathy (CSC) is a condition characterized by serous detachment of the neurosensory retina at the level of the retinal pigmented epithelium (RPE) as a result of leakage from the choriocapillaris. The pathophysiology of CSC is not completely understood rendering treatment and management decisions more complex. When an observational approach and topical medical therapy are unsuccessful, a surgical intervention may be necessary. Here, we examine the role of modified photodynamic therapy (PDT) in recurrent CSC with multiple points of RPE leakage. CASE REPORT: A 37-year-old male patient presented a case of recurrent CSC in the left eye. After an initial presentation of a large area of submacular fluid, near complete resolution was seen in 8 weeks using a topical NSAID protocol and close monitoring. Two weeks later, a second serous neurosensory detachment larger than the first occurred. The recurrent CSC was successfully treated with focal grid laser photocoagulation and modified PDT resulting in complete resolution and return of visual function 4 months after the initial presentation. CONCLUSIONS: CSC is a multifactorial condition with the potential to severely impair daily visual function. Spectral domain optical coherence tomography retinal imaging has provided a remarkable tool in the diagnosis and monitoring of CSC. The addition of FA and ICG can create a highly precise picture of the subretinal fluid. Although most patients will spontaneously resolve, a subset of patients may benefit from medical therapy including topical nepafenac 0.1%. A smaller subset will require surgical intervention. Modified PDT with ICG-guided laser photocoagulation has a growing body of evidence as an effective treatment for recurrent CSC. Modified PDT may be the best course of action for chronic, non-resolving RPE leakage for both paramacular and foveal leaks leading to minimization of adverse visual effects.

Effect of different pretreatments on functional properties of African catfish (Clarias gariepinus) skin gelatin.

Pretreatments with different types of alkali and acid were compared to determine their effects on gelatin extraction from African catfish (Clarias gariepinus) skin. The study was divided into three parts. In the first part, the skins were only treated with alkaline (Ca(OH)2 or NaOH) solution or pretreated with acetic acid solution. For second part, combination of alkali and acid pretreatment was carried out. For the third part, the skins were first treated with NaOH solution, followed by the treatment with acetic acid, citric acid or sulfuric acid solution. Functional properties including the yield of protein recovery, gel strength, viscosity, pH and viscoelastic properties were determined on gelatins obtained with different pretreatment conditions. Pretreatment with alkali removed noncollagenous proteins effectively, whilst acid pretreatment induced some loss of collagenous proteins. Combination of alkali and acid pretreatment not only removed the noncollagenous proteins and caused a significant amount of swelling, but also provided the proper pH condition for extraction, during which some cross-linkages could be further destroyed but with less breakage of intramolecular peptide chains. Pretreatment of catfish skins with 0.2 N NaOH followed by 0.05 M acetic acid improved yield of protein recovery, gel strength, viscosity, melting temperature and gelling temperature of gelatin extract.

Optimization and physical properties of gelatin extracted from pangasius catfish (Pangasius sutchi) bone.

In the present study, to establish the optimum gelatin extraction conditions from pangasius catfish (Pangasius sutchi) bone, Response Surface Methodology (RSM) with a 4-factor, 5-level Central Composite Design (CCD) was conducted. The model equation was proposed with regard to the effects of HCl concentration (%, X1), treatment time (h, X2), extraction temperature (°C, X3) and extraction time (h, X4) as independent variables on the hydroxyproline recovery (%, Y) as dependent variable. X 1 = 2.74 %, X 2 = 21.15 h, X 3 = 74.73 °C and X 4 = 5.26 h were found to be the optimum conditions to obtain the highest hydroxyproline recovery (68.75 %). The properties of optimized catfish bone gelatin were characterized by amino acid analysis, SDS-PAGE, gel strength, TPA and viscosity in comparison to bovine skin gelatin. The result of SDS-PAGE revealed that pangasius catfish bone gelatin consisted of at least 2 different polypeptides (α1 and α2 chains) and their cross-linked chains. Moreover, the pangasius catfish bone gelatin was found to contain 17.37 (g/100 g) imino acids (proline and hydroxyproline). Pangasius catfish bone gelatin also indicated physical properties comparable with that of bovine and higher than those from cold water fish gelatin. Based on the results of the present study, there is a potential for exploitation of pangasius catfish bone for gelatin production. Furthermore, RSM provided the best method for optimizing the gelatin extraction parameters.

Characterisation and evaluation of nano gelcoat degradations in marine environment.

Nanotechnology has been extensively explored and exploited for developing functional and smart coating systems with significant performance enhancement. In this context, a development of novel characterisation methodology for surface quality evaluation of diverse coating systems at nano and micro scales has great importance and significance. In this study, nano particles were introduced into conventional gelcoat system in an attempt to achieve improved coating quality and enhanced anti-blistering performance. Accelerated gelcoat ageing in a marine environment was carried out by maintaining constant contact with water using a purpose built jig at 65 degrees C. The progressive ageing of samples has been monitored and evaluated by visual observation, nano-indention test, surface roughness and profile measurement. It was observed that the addition of nano-clays led to an increase in hardness. Although the ageing of various coating systems resulted in a reduction in hardness, the degree of hardness change due to ageing for all nano-coating was significantly less than for coating system without nano-clays. The coating degradations were further characterised by reduced surface homogeneity in terms of standard deviations of hardness. The accelerated ageing induced coating degradations were also quantified by surface profile and roughness measurement in which a stylus profilometer was employed to scan different locations of the coatings. It showed significant differences in surface roughness of different coatings systems and incremental degradations as a function of ageing durations. It has demonstrated that anti-blistering gelcoat systems can be developed by introducing chemically modified nano-clays into conventional gelcoat systems for marine applications.

Contrasting reactive oxygen species and transition metal concentrations in combustion aerosols.

The presence of reactive oxygen species (ROS) and 10 transition metals (Ag, Cd, Co, Cu, Fe, Mn, Ni, Ti, V and Zn) in both the acid-soluble and water-soluble fractions of fine particles of combustion origin were determined. ROS was analyzed using the dichlorofluorescin fluorescence technique. Particles emitted from on-road vehicles, gas cooking, incense burning, and cigarette smoke were characterized along with those in the background air of outdoor and indoor environments. In addition, this study evaluated the possible relationships between ROS and individual transition metals. It is found that cigarette smoke which had the highest concentration of metals also contained the highest concentration of ROS. Regression analysis performed showed that water-soluble metals including Cd, Co, Cu, Fe, Mn, and Ni showed better correlation with ROS concentration as compared to acid-soluble (total) metals. The findings demonstrated that water-soluble metals could be one of the species influencing ROS formation in ambient air.

Risk assessment of exposure to indoor aerosols associated with Chinese cooking.

Cooking is an important source of indoor aerosols in residential homes and buildings with non-smokers, and thus has public health implications. However, limited information is currently available in the published literature on the physical and chemical characteristics of aerosols produced by gas cooking. Consequently, a comprehensive study was carried out to investigate the physical (number and mass concentrations and size distributions) and chemical (metals) properties in a typical Chinese food stall in Singapore where stir-frying in a wok is the most common cooking method using gas stove. To assess the contribution of cooking activities to indoor particle concentrations, aerosol measurements were performed in two distinct time periods, i.e., during cooking and non-cooking hours. The average mass concentrations of fine particles (PM(2.5)) and metals increased by a factor of 12 and 11, respectively, from 26.7 and 1.5microgm(-3) during non-cooking hours to 312.4 and 15.6microgm(-3) during cooking hours. The average number concentration was also elevated by a factor of 85, from 9.1x10(3)cm(-3) during non-cooking hours to 7.7x10(5)cm(-3) during cooking hours. Real-time particle measurements showed that about 80% of the particles associated with cooking are ultrafine particles in terms of particle counts. To evaluate the potential health threat due to inhalation of air pollutants released from gas cooking, the health risk estimates based on exposure and dose-response assessments of metals were calculated for a maximally exposed individual. The findings indicate that the indoor air quality existing at the food stall may pose adverse health effects over long-term exposure to cooking emissions.

Oligodendroglial tumor chemotherapy using "decreased-dose-intensity" PCV: a Singapore experience.

The authors propose "decreased-dose-intensity" PCV (procarbazine, lomustine [CCNU], and vincristine) chemotherapy for Asian patients with oligodendroglial tumors. In this study, all seven patients with oligodendroglioma (OD) and eight with anaplastic oligodendroglioma (AO) had objective responses or stable disease. Median progression-free survival was greater than 29 months (OD) and 36.5 months or greater (AO); 86% of patients with OD and 63% with AO remain progression-free. Twenty-four Common Toxicity Criteria Grade 3/4 adverse events were noted.

Case reports of two biopsy-proven patients with Creutzfeldt-Jakob disease in Singapore.

INTRODUCTION: Creutzfeldt-Jakob disease (CJD) is the most common transmissible human subacute spongiform encephalopathy. There is limited literature on CJD in Southeast Asia. We describe the clinical course and diagnostic evaluation of 2 Singapore patients with biopsy-proven CJD. CLINICAL PICTURE: Two patients presented with non-specific symptoms such as withdrawal, forgetfulness, asthenia, giddiness and insomnia. Both patients had spontaneous myoclonic jerks and impairment of multiple neurologic systems (visual, pyramidal, cerebellar and neurocognitive systems). Magnetic resonance imaging and electroencephalography provided helpful supportive evidence. Diagnosis of CJD was established on brain biopsy. Histological features included spongioform degeneration, neuronal cell loss and astrocytosis. TREATMENT/OUTCOME: Treatment remains palliative. Deterioration in their clinical condition was relentless, progressing to a totally dependent state within 10 to 12 months. CONCLUSION: The early features of CJD can be varied and non-specific. It is important for physicians from different specialties to be cognisant of the clinical manifestations of CJD and the appearance of supportive and definitive investigations.

Severe amphethamine-induced bruxism: treatment with botulinum toxin.

While chewing and grinding movements have been observed in amphetamine addicts, recognition and management of this problem have rarely been highlighted. Botulinum toxin (BTX) has previously been demonstrated to be effective for bruxism associated with movement disorders, such as cranial-cervical dystonia. However, there is little information on its use in tardive bruxism. Here we report an amphetamine addict who presented with medically intractable bruxism, and discuss its pathophysiology and successful treatment with BTX.

Antibiotics versus control for toxoplasma retinochoroiditis.

BACKGROUND: Acute toxoplasma retinochoroiditis causes transient symptoms of ocular discomfort and may lead to permanent visual loss. Antibiotic treatment primarily aims to reduce the risk of permanent visual loss, recurrent retinochoroiditis, and the severity and duration of acute symptoms. There is uncertainty about the effectiveness of antibiotic treatment. OBJECTIVES: The objective of this review was to compare the effects of antibiotics versus placebo or no treatment for toxoplasma retinochoroiditis. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register - CENTRAL/CCTR, which contains the Cochrane Eyes and Vision Group Specialised Register (Cochrane Library Issue 2, 2001), MEDLINE (1966 to August 2001), EMBASE (1980 to September 2001), Dissertation Abstracts (1861 to June 2001), LILACS (1982 to 1998), Pascal (1984 to March 2000), proceedings of the Association for Research in Vision and Ophthalmology (1980 to 2001), international symposia on uveitis, and reference lists of review articles. Pharmaceutical companies were contacted for unpublished trials. SELECTION CRITERIA: We included randomised controlled trials that compared any systemic antibiotic treatment against placebo or no treatment. Trials that included immunocompromised patients were excluded. DATA COLLECTION AND ANALYSIS: The primary outcomes for this review were visual acuity at least three months after treatment and risk of recurrent retinochoroiditis. Secondary outcomes were improvement in symptoms and signs of intraocular inflammation, size of lesion and adverse events. Effect measures were pooled using a random effects model. MAIN RESULTS: Three trials, which randomised a total of 173 participants, met the inclusion criteria. All trials were methodologically poor. None reported the effect of treatment on visual acuity. Two studies reported results for recurrent retinochoroiditis: one (124 participants) found a significant reduction in participants with chronic recurrent disease who were treated for 14 months: relative risk 0.28 (95% confidence interval 0.10 to 0.78); the other (20 participants) found no evidence of an effect in participants with acute toxoplasma retinochoroiditis (relative risk 1.00, 95% confidence interval 0.07 to 13.87). Two studies reported an improvement in intraocular inflammation in treated compared with untreated participants and one study reported no difference. Two studies found an increased risk of adverse events in treated participants. REVIEWER'S CONCLUSIONS: There is a lack of evidence to support routine antibiotic treatment for acute toxoplasma retinochoroiditis. There is weak evidence to suggest that long-term treatment of patients with chronic recurrent toxoplasma retinochoroiditis may reduce recurrence. Placebo controlled trials of patients with acute and chronic toxoplasma retinochoroiditis affecting any part of the retina are required to determine the effectiveness of antibiotic treatment.

Redefining therapeutic success with virtual reality exposure therapy.

The success rate for treating phobias with in vivo exposure is high. Unfortunately, few phobics (less than 15-20%) ever seek treatment. Virtual reality (VR) exposure therapy is also proving to be highly effective. The present surveys assessed 162 students high in fear of spiders. In Study 1, when asked to choose between multisession in vivo exposure vs. multisession VR exposure therapy, 81% chose VR. In Study 2, comparing one-session in vivo versus multisession VR exposure therapy, 89% chose VR. Results suggest that VR exposure therapy may prove valuable for increasing the number of phobics who seek treatment.

Trimethoprim/sulfamethoxazole-induced toxic epidermal necrolysis.

OBJECTIVE: To report a case of toxic epidermal necrolysis (TEN) associated with trimethoprim/sulfamethoxazole (TMP/SMX). CASE SUMMARY: A 34-year-old Asian woman developed a severe, desquamating mucocutaneous reaction (TEN) after six days of taking TMP/SMX to treat a presumed urinary tract infection (UTI). DISCUSSION: TMP/SMX is often recommended as first-line therapy for UTIs, sinusitis, bronchitis, and as prophylaxis and treatment for Pneumocystis carinii pneumonia. TEN is a rare, but severe condition associated with sulfonamide use. This article describes a typical case and offers an opportunity for review of this potentially serious reaction. CONCLUSIONS: Sulfonamides are often implicated in the majority of drug-induced cases of TEN. This case report illustrates the typical presentation of sulfonamide-induced TEN with a prodrome, characteristic rash, mucous membrane lesions, and systemic involvement. Practitioners should be aware of this rare adverse effect and closely observe patients for cutaneous manifestations or complaints. Any suspected drug should be discontinued if clinical evaluation leads to the suspicion of Stevens-Johnson syndrome or TEN.

Restless legs syndrome in an Asian population: A study in Singapore.

In face-to-face interviews, we examined 157 consecutive individuals aged 55 years and older, selected from the general population in Singapore, and 1,000 consecutive individuals aged 21 years and older, from a primary healthcare center. Based on the IRLSSG criteria, the prevalence of restless leg syndrome (RLS) was 0.6% and 0.1%, respectively.

Perceptions of an old female eyewitness: is the older eyewitness believable?

Young adults rated an old female witness (82 years) to be less competent but more honest than a young female witness (28 years). The effect of age stereotyping on believability was assessed indirectly by using a variant of Loftus' misinformation paradigm. Regression analysis showed that the more competent a witness was perceived as being, the more influential was the misinformation she provided. This was true, however, only when the witness was young because the relatively lower competence of the old witness was associated with nonsignificant misinformation effects. These data suggest that negative beliefs associating incompetence with old age may compromise the believability of older eyewitnesses.

Social influences on reality-monitoring decisions.

A modified Asch (1951) conformity paradigm was used to study the impact of social influence on reality-monitoring decisions about new items. Subjects studied pictures of some objects and imagined others. In a later test phase, they judged whether items had been perceived in the study phase, had been imagined, or were new. Critically, for some items, the subjects were informed of a confederate's response before rendering a judgment. Although the confederate was always correct when they responded to old items, for new items, the confederate responded perceived, imagined, or new, or did not respond (baseline). In two experiments, we show that memory for new items was influenced by an erroneous response of the confederate. Social conformity was reduced by undermining the credibility of the confederate (Experiments 1A and 1B), and the confederate's influence was evident even after there was only a 20-min delay between study and test (Experiment 2), when the subjects were 87% accurate on new baseline items. These experiments reveal the power of social influence on reality-monitoring accuracy and confidence.

Angiotensin II receptor blockers for the treatment of hypertension.

The rising incidence of stroke, congestive heart failure (CHF) and end stage renal disease (ESRD) has signalled a need to increase awareness, treatment and control of hypertension. There continues to be a need for effective antihypertensive medications since hypertension is a major precursor to various forms of cardiovascular disease. The renin-angiotensin (AT) aldosterone system (RAAS) is a key component to the development of hypertension and can be one target of drug therapy. Angotensin II (ATII) receptor blockers (ARBs) are the most recent class of agents available to treat hypertension, which work by by inhibiting ATII at the receptor level. Currently, national consensus guidelines recommend that ARBs should be reserved for hypertensive patients who cannot tolerate angiotensin converting enzyme (ACE) inhibitors (ACEIs). ARBs, however, are moving to the forefront of therapy with a promising role in the area of renoprotection and CHF. Recent trials such as the The Renoprotective Effect of the Angiotensin-Receptor Antagonist Irbesartan in Patients with Nephropathy Due to Type 2 Diabetes Trial (IDNT), the Effect of Irbesartan on the Development of Diabetic Nephropathy in Patients with Type 2 Diabetes (IRMA2), and The Effects of Losartan on Renal and Cardiovascular Outcomes in Patients with Type 2 Diabetes and Nephropathy (RENAAL) study have demonstrated the renoprotective effects of ARBs in patients with Type 2 diabetes. The Valsartan Heart Failure Trial (Val-HeFT) adds to the growing body of evidence that ARBs may improve morbidity and mortality in CHF patients. As a class, ARBs are well tolerated and have a lower incidence of cough and angioedema compared to ACEIs. This article reviews the differences among the ARBs, existing efficacy data in hypertension, and explores the role of ARBs in CHF and renal disease.