Preparing Malaysia for Population Aging through the Advanced Memory and Cognitive Service in Hospital Universiti Sains Malaysia

Improving healthcare and living conditions has led to an increase in life expectancies and challenges of population aging in Malaysia. The Advanced Memory and Cognitive Service builds on integrated healthcare among multidisciplinary specialists to provide holistic and patient-centred healthcare. The service treats older adults experiencing neurocognitive impairment as well as young individuals with complex neurocognitive disorders and thoroughly screens asymptomatic individuals at high risk of developing neurocognitive disorders. This early intervention strategy is a preventive effort in the hope of reducing disease burden and improving quality of life to prepare Malaysia for the forthcoming population aging.

Benzodiazepines for Treatment-Resistant Major Depressive Disorder and Obsessive-Compulsive Disorder With Comorbid Mega Cisterna Magna

This article discusses the case of an adult woman with comorbid major depressive disorder (MDD) and obsessive-compulsive disorder (OCD). Due to her poor response to initial treatment regimens, a brain computed tomography (CT) was performed, revealing mega cisterna magna (MCM). Subsequently, she responded well to the addition of lorazepam, a benzodiazepine, along with fluvoxamine and quetiapine XR. The clinical significance of MCM and MDD-OCD remains partially understood. Thus, this case report aims to contribute to the literature and review the treatment of benzodiazepines in relation to MCM, MDD, and OCD comorbidities.

Dawn of Staging for Head and Neck Soft Tissue Sarcoma: Validation of the Novel 8th Edition AJCC T Classification and Proposed Stage Groupings

PURPOSE/OBJECTIVE(S)

After decades of stagnation, the 8th edition TNM (TNM8) introduced a new T classification for head and neck (HN) soft tissue sarcomas (STS). New size cutoffs of 2 and 4 cm define T1-3, and a novel T4 category is defined by local invasion of adjoining structures. These size cutoffs had been chosen arbitrarily to advance data collection in this unique disease site since literature showed approximately 70% of HN STS did not reach the previous size threshold (5 cm) for the existing T1 category. The definition of the TNM8 T categories also align with mucosal HN cancers. No stage grouping for HN STS was defined since this new classification required more data collection to derive stage groups. This study aims to validate the TNM8 T classification and to propose stage groupings.

MATERIALS/METHODS

Clinical data of all adult (>16 years) HN STS patients treated from 1988 - 2019 with curative intent in our tertiary cancer center were retrieved from a prospective database, and supplemented with chart review. As per TNM8, cutaneous angiosarcoma, embryonal and alveolar rhabdomyosarcoma, Kaposi sarcoma, and dermatofibrosarcoma protuberans were excluded due to their different behavior. Multivariate analysis (MVA) identified prognostic factors for overall survival (OS). Adjusted hazard ratios (AHR) and recursive partitioning analysis (RPA) were used to derive stage groupings. Stage grouping performance for OS was assessed and also compared against the existing TNM8 groups for non-HN STS.

RESULTS

A total of 221 patients (N1: 2; M1: 2) were included. Of the 219 M0 patients, 63% were males; median tumor size was 3.0 cm (range: 0.3-14.0); the proportion of TNM8 T1-T4 were 35%, 34%, 26%, and 5%, respectively. Median follow up was 5.9 years. Five-year OS was 79%. MVA confirmed the prognostic value of T category (T4 HR 7.73, 95% CI 3.62-16.5) and grade (G2/3 vs G1 HR 3.7, 95% CI 1.82-7.53), in addition to age (HR 1.03, 95% CI 1.01-1.04) (all p<0.001) for OS. AHR model derived T1-3_Grade 1 as stage 1; T1-3_Grade 2/3 as stage II; and T4_any Grade or any T_N1 as stage III (Table 1); the corresponding 5-year OS was 93%, 73%, and 38%, respectively. Both patients with M1 died within 1.5 years after diagnosis and M1 disease was designated stage IV. The AHR-grouping outperformed the RPA and non-HN TNM8 stage grouping for hazard consistency, hazard discrimination, percent variance explained, hazard difference, and sample size balance.

CONCLUSION

The novel T4 category introduced in TNM8 is associated with a >7 fold increased risk of death. Grade continues to be a critical prognostic factor in HN STS. The TNM8 HN STS T classifications have been validated, and the proposed new stage groupings with TNM8 incorporating grade have excellent performance for OS.

Outcomes of Head and Neck Cutaneous Angiosarcoma Treated in the IMRT Era

PURPOSE/OBJECTIVE(S)

Clinical behavior, natural history, and varied presentations of cutaneous angiosarcomas of the head and neck region (HN), in conjunction with its rarity, have rendered standardization of treatment elusive. We aimed to assess outcomes and patterns of failure for patients treated with surgery and radiation (Sx+RT), and radiation alone (RT).

MATERIALS/METHODS

A retrospective review of all HN angiosarcoma patients amenable for upfront Sx or RT in our institution between 2004-2018 was completed. Generally, treatment included Sx when feasible, and RT for large or extensive/ill-defined tumors. Demographic, tumor characteristics, local (LC), regional (RC), distant control (DC), and overall survival (OS), as well as patterns (in-field, marginal, out-of-field) of local failure at 5-year were estimated. Univariate analysis (UVA) was conducted to assess association with outcomes.

RESULTS

A total of 33 patients were eligible (14 Sx+RT and 19 RT). Tumor locations were: scalp (16, 48%). face (n = 12, 36%), and overlapping (5, 15%). Lesion types were: nodular (n = 23, 70%), flat (n = 4, 12%) and mixed (n = 6, 18%). Tumor size was larger in the RT group (median: 10.00 vs 2.85 cm, p<0.01). RT and Sx+RT patients had otherwise similar baseline characteristics: median age 74.3; male 70%; and ECOG performance status ≤1 85%. RT dose fractionations ranged from 50-70 Gy in 25-35 fractions in the RT group and 50-66 Gy in 25-33 fractions in the Sx+RT group. Four (12%) patients received neoadjuvant chemotherapy. Median follow up was 5.5 years. Five-year LC, RC, DC, and OS for RT vs Sx+RT groups were 68% vs 85% (p = 0.28); 95% vs 86% (p = 0.89); 79% vs 86% (p = 0.39); and 45% vs 55% (p = 0.71), respectively. The in-field/marginal/out-of-field local failure rate at 5 years were 16% vs 7% (p = 0.46), 26% vs 15% (p = 0.41), and 13% vs 0% (p = 0.24) for the RT vs Sx+RT groups, respectively. UVA showed that scalp location and ulceration/bleeding were strong adverse features for OS. Bone invasion was significantly associated with lower DC (Table). Lesion type (nodular/flat/mixed), tumor size, and treatment type (Sx+RT vs RT), were not significantly associated with LC or pattern of local failure.

CONCLUSION

Scalp tumors, as compared to face, portended poorer prognosis, and ulceration/bleeding and bone invasion were associated with increased distant metastases. Sx+RT was the preferred treatment modality when possible and typically used for smaller and better defined tumors. RT was reserved for larger and extensive/ill-defined disease; despite this, in the IMRT era, RT achieves reasonable rates of control, markedly superior to historical series.

The Brain-Gut Clinic in Hospital Universiti Sains Malaysia: Pioneering New Service to Advance Neuro-Gastroenterology and Motility in Malaysia

Neurogastroenterology and motility is a new but advanced subspecialty within gasteroenterology that cater to difficult, persistent and refractory gut-brain symptoms. Hospital USM has the country's first and new state-of-the art motility lab that was recently launched on the 25 May 2023, and is covered in nationwide media. Another first is the Brain-Gut Clinic, established on the 16 November 2022. The clinic is a new concept that builds on unique multiple disciplines in relation to the gut-brain axis. It is hoped that there will be more awareness on the existence of neurogastroenterology and motility among doctors and community, and that more research can be forthcoming to reduce the disease burden.

Predictors of Mental Health Literacy among Parents, Guardians, and Teachers of Adolescents in West Malaysia

Parents, guardians, and teachers are the informal sources of mental health support that adolescents rely on. Nevertheless, limited mental health knowledge limits their ability and confidence in providing appropriate assistance. This study aims to (1) evaluate the relationship between the roles of parents/guardians and teachers and their responses to discover the common misconceptions on mental health among those providing informal support to adolescents and (2) determine which demographic factors would act as the strongest predictor influencing their mental health literacy (MHL) status. The cross-sectional study recruited 867 parents, guardians, and teachers of adolescents from 24 government secondary schools' parent-teacher associations via multistage stratified random sampling. Parents, guardians, and teachers' MHL were evaluated using the Mental Health Knowledge Schedule-Malay Version (MAKS-M). The collected data were analyzed using Pearson's Chi-squared test to investigate the association between the respondents' roles and responses. Multiple Regression analysis was used to determine the predictors of MHL. The score of MAKS-M for the current study sample is 73.03% (M = 43.82, SD = 4.07). Most respondents responded incorrectly on Items 1 (employment), 6 (help-seeking), 8 (stress), and 12 (grief). Teachers provided more favorable responses on several items than parents and guardians. Finally, younger age, higher income, knowing someone with mental disorders, and having experience of attending formal training on mental health first aid were the significant predictors of MHL. MHL interventions in Malaysia should cater to older adults of lower socioeconomic status and lesser experience in mental health, specifically highlighting the stigmas on mental health help-seeking behaviors, treatment, and employment concerns, plus the recognition of various mental health diagnoses.

The Malay Literacy of Suicide Scale: A Rasch Model Validation and Its Correlation with Mental Health Literacy among Malaysian Parents, Caregivers and Teachers

The 27-item Literacy of Suicide Scale (LOSS) is a test designed to measure the respondent’s suicide knowledge. The purpose of this study is to examine the psychometric properties of the Malay-translated version of the LOSS (M-LOSS) and its association to sociodemographic factors and mental health literacy. The 27-item LOSS was forward–backward translated into Malay, and the content and face validities were assessed. The version was distributed to 750 respondents across West Malaysia. Rasch model analysis was then conducted to assess the scale’s psychometric properties. The validated M-LOSS and the Malay version of the Mental Health Knowledge Schedule (MAKS-M) were then distributed to 867 respondents to evaluate their level of suicide literacy, mental health literacy, and their correlation. Upon Rasch analysis, 26 items were retained. The scale was found to be unidimensional, with generally satisfying separation and reliability indexes. Sex, socio-economic status, and experience in mental health were found to significantly impact the mean score for mental health literacy. This study also found a significant mean difference for suicide literacy across school types. Furthermore, while this study observed a weak but significant negative correlation between age and suicide literacy, no correlation was found between mental health and suicide literacy.

What Are the Common Themes of Physician Resilience? A Meta-Synthesis of Qualitative Studies

In the practice of medicine, resilience has gained attention as on of the ways to address burnout. Qualitative studies have explored the concept of physician resilience in several contexts. However, individual qualitative studies have limited generalizability, making it difficult to understand the resilience concept in a wider context. This study aims to develop a concept of resilience in the context of physicians' experience through a meta-synthesis of relevant qualitative studies. Using a predetermined search strategy, we identified nine qualitative studies among 450 participants that reported themes of resilience in developed and developing countries, various specialties, and stages of training. We utilized the meta-ethnography method to generate themes and a line-of-argument synthesis. We identified six key themes of resilience: tenacity, resources, reflective ability, coping skills, control, and growth. The line-of-argument synthesis identified resilient physicians as individuals who are determined in their undertakings, have control in their professional lives, reflect on adversity, utilize adaptive coping strategies, and believe that adversity provides an opportunity for growth. Resilient physicians are supported by individual and organizational resources that include nurturing work culture, teamwork, and support from the medical community and at home. Our findings suggest that resilience in physicians is dynamic and must be supported not only by physician-directed interventions but also by organization-directed interventions.

Training Characteristics, Personal Factors and Coping Strategies Associated with Burnout in Junior Doctors: A Multi-Center Study

Physician burnout has been recognized as a public health crisis. However, there is a paucity of burnout studies in the context of medical internship. We assessed the prevalence and relationship between various training characteristics, personal variables, resilience, and coping with burnout in a cross-sectional study involving 837 interns from ten hospitals across Malaysian healthcare system. The instrument package included demographic questions, the Connor-Davidson Resilience Scale, Brief COPE and the Copenhagen Burnout Inventory. A total of 754 (90.1%) interns completed the inventories. We found a high prevalence of personal-related (73.3%), work-related (69.1%), and patient-related (43.4%) burnout among Malaysian interns. Multivariable analysis showed female gender (odds ratio (OR):1.50; 95% confidence interval (CI): 1.02-2.20), prior work experience (OR: 1.56; 95% CI: 1.05-2.30), and irregular spirituality routines (OR: 1.97; 95% CI: 1.30-2.99) were associated with increased odds of personal-related burnout. Irregular spirituality routines (OR: 2.24; 95% CI: 1.49-3.37) were associated with work-related burnout, while living with other people (OR: 1.77; 95% CI: 1.15-2.73) was associated with patient-related burnout. Lower resilience levels and avoidant copings were associated with personal-, work-, and patient-related burnout. Burnout prevalence among interns is high. The findings support the value of individual-targeted alongside organizational-targeted intervention in burnout reduction. As burnout is prevalent in both years of internship training, ongoing burnout prevention and wellbeing measures are deemed necessary.

A Critical Appraisal of COVID-19 in Malaysia and Beyond

When the first report of COVID-19 appeared in December 2019 from Wuhan, China, the world unknowingly perceived this as another flu-like illness. Many were surprised at the extreme steps that China had subsequently taken to seal Wuhan from the rest of the world. However, by February 2020, the SARS-CoV-2 virus, which causes COVID-19, had spread so quickly across the globe that the World Health Organization officially declared COVID-19 a pandemic. COVID-19 is not the first pandemic the world has seen, so what makes it so unique in Malaysia, is discussed to avoid a future coronacoma.

Evaluation of Retinal Nerve Fiber Layer Thickness, Electroretinogram and Visual Evoked Potential in Patients with Alzheimer's Disease

OBJECTIVE

To study the retinal nerve fibre layer (RNFL) thickness and visual electrophysiology testing in patients with Alzheimer's disease (AD).

METHODS

A cross-sectional, hospital-based study: 25 AD subjects and 25 controls were recruited. Candidates who fulfil the criteria with normal ocular examinations were made to proceed with scanning laser polarimetry, pattern electroretinogram (PERG), and pattern visual evoked potential (PVEP) examinations of the right eye. RNFL thickness, PERG, and PVEP readings were evaluated.

RESULTS

In AD, the mean of average RNFL thickness was 45.28 μm, SD = 3.61, P < 0.001 (P < 0.05), while the superior RNFL thickness was 54.44 μm, SD = 2.85, P < 0.001 (P < 0.05) and inferior RNFL thickness was 47.11 μm, SD = 4.52, P < 0.001 (P < 0.05). For PERG, the mean P50 latency was 63.88 ms, SD = 7.94, P < 0.001 (P < 0.05) and the mean amplitudes of P50 waves were 1.79 μV, SD = 0.64, P < 0.001 (P < 0.05) and N95 waves were 2.43 μV, SD = 0.90, P < 0.001 (P < 0.05). For PVEP, the mean latency of P100 was 119.00 ms, SD = 9.07, P < 0.001 (P < 0.05), while the mean latency of N135 was 145.20 ms, SD = 8.53, P < 0.001 (P < 0.05). The mean amplitude of P100 waves was 3.71 μV, SD = 1.60, P < 0.001 (P < 0.05), whereas the mean amplitude of N135 waves was 3.67 μV, SD = 2.02, P < 0.001 (P < 0.05). RNFL thickness strongly correlates with PERG readings, with P50 latency R = 0.582, R2 = 0.339, P=0.002 (P < 0.05), amplitude of P50 wave at R = 0.749, R2 = 0.561, P ≤ 0.001 (P < 0.05), and amplitude of N95 wave at R = 0.500, R2 = 0.250, P=0.011 (P < 0.05). No significant difference and correlation were observed on PVEP readings.

CONCLUSION

The mean of the average, superior and inferior RNFL thickness were significantly lower in the AD group compared with control. There is also significant difference of PERG and PVEP parameters between AD and controls. Regression analysis showed average RNFL thickness having significantly linear relationship with the PERG parameters.

Use of Potentially Inappropriate Medications in People With Dementia in Vietnam and Its Associated Factors

This study examined the use of potentially inappropriate medicines that may affect cognition (PIMcog) in people with dementia and its associated factors. Medical records of all outpatients with dementia attending a tertiary hospital in Vietnam between January 1, 2015, and December 31, 2016, were examined. Medicine use was assessed against a list of PIMcog. Variables associated with having a PIMcog were assessed using a multiple logistic regression. Of the 128 patients, 41% used a PIMcog, 39.1% used cholinesterase inhibitors (CEIs) concomitantly with anticholinergics, and 18% used antipsychotics. The number of hospital visits (adjusted odds ratio [OR]: 1.08; 95% confidence interval [CI]: 1.02-1.16) and number of treating specialists (adjusted OR: 0.61; 95% CI: 0.45-0.83) were associated with PIMcog use. This study highlights a high-level use of medicines that can further impair cognition or reduce the effectiveness of CEIs in people with dementia. Efforts to improve quality use of medicines for this population are warranted.

Cultural Construction of Psychiatric Illness in Malaysia

The concept of the cultural construction of illness is important in terms of understanding people's behaviour. In this article, this idea is applied to psychiatric illness in Malaysia to explore how it is informed by sociocultural elements, a process that will help us understand the psychiatric expression and help-seeking behaviour of the country's population.

A frontal external ventricular drain causing a third cranial nerve palsy

This 47-year-old gentleman presented with acute hydrocephalus secondary to a colloid cyst. Bilateral external ventricular drains (EVDs) were inserted. The patient developed a third nerve palsy during post-operative period - cranial imaging demonstrated the tip of an EVD in this vicinity. The palsy recovered completely on slight withdrawal of the EVD.

Some mechanical properties of a highly cross-linked, microwave-polymerized, injection-molded denture base polymer

PURPOSE

The impact strength and the flexural properties of denture base materials are of importance in predicting their clinical performance upon sudden loading. This study compares the impact and transverse strengths and the flexural modulus of three denture base polymers.

MATERIALS AND METHODS

The investigation included a relatively new microwave-polymerized polyurethane-based denture material processed by an injection-molding technique, a conventional microwave-polymerized denture material, and a heat-polymerized compression-molded poly(methyl methacrylate) (PMMA) denture material. Impact strength was determined using a Charpy-type impact tester. The transverse strength and the flexural modulus were assessed with a three-point bending test. The results were subjected to statistical analysis using a one-way analysis of variance and the Scheffé test for comparison.

RESULTS

The impact strength of the microwave-polymerized injection-molded polymer was 6.3 kl/m2, while its flexural strength was 66.2 MPa. These values were lower than those shown by the two compression-molded PMMA-based polymers. The differences were statistically significant. The flexural modulus of the new denture material was 2,832 MPa, which was higher than the conventional heat-polymerized polymer but was comparable to the other microwave-polymerized PMMA-based polymer. The difference in the flexural modulus was statistically significant.

CONCLUSION

In terms of the impact and flexural strengths, the new microwave-polymerized, injection-molded, polyurethane-based polymer offered no advantage over the existing heat- and microwave-polymerized PMMA-based denture base polymers. However, it has a rigidity comparable to that of the microwave-polymerized PMMA polymer.

Alteration of cell-wall composition of Fusarium oxysporum by copper stress

A strain of Fusarium oxysporum tolerated copper in the growth medium at concentrations up to 600 mg/L. The optimum growth was obtained at 200 mg Cu/L. The mycelium acquired a blue color in the presence of copper. The copper content of isolated cell walls obtained from mycelium grown in the presence of 600 mg Cu/L was 1.5 times higher than that of cell walls obtained from mycelium grown at 200 mg Cu/L and it contained 2.2 and 3.3% copper at 200 and 600 mg Cu/L, respectively. The amount of protein and total sugars increased in both the mycelium and its isolated cell walls in the presence of copper in the growth medium, chitin was also increased in the cell wall, reaching its maximum amount at 200 mg Cu/L--about 2.4 times higher than without copper. Most of amino acid concentrations in the cell wall were increased in the presence of 200 mg Cu/L and decreased above this concentration. Isoleucine, leucine, tyrosine, phenylalanine, and arginine showed the highest increase at this concentration. The altered cell walls obtained from mycelium grown at 200 and 400 mg Cu/L could rebind individual metals more than the control cell walls could. Rebinding of individual metals was in the order Zn > Fe > Ni > Cu > Co. Rebinding of copper by isolated cell walls depended on pH and temperature.

The optimum curing cycle for a light- and heat-cured composite inlay material

The transverse bend test and surface microhardness test were used to determine the optimum curing cycle for a light- and heat-cured composite inlay material. Specimens were light-cured (control) and light- and heat-cured using the following temperatures: 50 degrees C for 5 min; 50 degrees C for 10 min; 100 degrees C for 1 min; 100 degrees C for 5 min; 100 degrees C for 10 min; and 100 degrees C for 15 min. Heat-curing in boiling water at 100 degrees C for at least 1 min significantly improved the transverse strength, modulus of elasticity and surface microhardness compared to light-curing only or at 50 degrees C. The curing cycle of 100 degrees C for 5 min is considered the most appropriate.

The effect of filler content and processing variables on dimensional accuracy of experimental composite inlay material

STATEMENT OF PROBLEM

Dimensional accuracy of a composite inlay restoration is important to ensure an accurate fit and to minimize cementation stresses.

PURPOSE OF STUDY

A method was developed to measure dimensional accuracy and stability of a composite inlay.

MATERIAL AND METHODS

A standard Class II (MOD) inlay cavity stainless steel mold was made with six circular indentations placed on the occlusal floor of the cavity and four indentations on each gingival floor to act as datum points in the measurement of linear polymerization shrinkage. The inlay restorations were prepared from an inlay-onlay composite material of different filler contents (50%, 65%, and 79% by weight). For each filler content group, three curing methods were used: light curing only, light curing and heat curing at 100 degrees C for 5 minutes, and light curing and heat curing at 100 degrees C for 5 minutes and then storage in distilled water for 7 days. The accuracy of the MOD inlays was determined by measuring the shrinkage of the restoration on the occlusal floor areas and the gingival seats.

RESULTS

The results demonstrated an inverse linear relationship between filler content and polymerization shrinkage. There was a tendency for the light-curing and heat-curing method to show an increase in polymerization shrinkage. An expansion was recorded between the mesial and distal boxes when the specimens were soaked in water for 7 days.

CONCLUSIONS

This study suggested that the inlay mold limits the physical shrinkage that can occur between the mesial and distal axial walls of the inlay restoration because the inlay cannot shrink to a smaller dimension than the mold. Water sorption then causes hygroscopic expansion, which enlarges the distance between the mesial and distal walls.

Effect of fungistatic agent 2-deoxy-D-glucose on mycotoxins from Penicillium expansum

Mycotoxin production from Penicillium expansum was effected by the 'biocontrol enhancer' 2-deoxy-D-glucose (DOG). Citrinin and gentisyl alcohol were produced in higher amounts, whereas patulin was inhibited, which represents a differential effect on the polyketide metabolic pathway. These effects have implications for the use of DOG in biocontrol.

Cadmium, selenium, and tellurium chelators in Aspergillus terreus

Aspergillus terreus was cultivated on Harrold's medium supplemented with 0.1% (w/v) cadmium chloride as well as on sulfur free medium amended with 0.1% (w/v) sodium selenite and potassium tellurite separately. The cell free extract of the fungus for each treatment was fractionated on a column packed with Sephadex G 75. The results demonstrated the ability of the fungus to synthesize several cadmium, selenium, and tellurium-binding proteins as well as metallothionein. The results suggested the biosynthesis of heavy metals chelators as well. The amino acids composition of a cadmium-binding metallothionein revealed the presence of high levels of both aromatic and sulfur amino acids in the hydrolysate.

Influence of selenium on the efficiency of fungicide action against certain fungi

Aspergillus funiculosus was isolated from rotted banana fruits, whereas Alternaria tenuis and Fusarium sp. were isolated from rotted tomato fruits. The isolated fungi tolerated relatively high levels of the fungicide, Dithane, up to 2560 ppm on solid medium, but grew well at 40 ppm when supplemented with liquid medium. They are able to tolerate selenite up to 2% (w/v) sodium selenite. A. funiculosus showed no growth in the presence of mixture of 2.5 ppm selenium and 20 ppm Dithane, whereas Fusarium sp. failed to grow at 2.5 ppm selenium and 10 ppm Dithane, or at 10 ppm of each. Nevertheless, Alternaria tenuis is more tolerant; it showed growth in the presence of relatively high levels of selenium and Dithane; up to 10 ppm selenium and 40 ppm Dithane, however, its growth was inhibited by the presence of a mixture of both. The results suggested new form of highly active fungicides. Selenium as an essential nutrient at such very low concentrations, as well as the application of very low concentrations of the fungicide, would certainly reduce the hazardous effect of such pollutant in the environment.

Metabolism of selenium in a selenium-dependent bacterium

A selenium-dependent Bacillus sp. is able to grow well up to 3% sodium selenite-containing media. The bacterium completely failed to grow on media devoid of selenium. The presence of selenium in the growth media increased the bacterial contents of proteins, carbohydrates, and lipids. The highest quantities of amino acids were detected at 2% sodium selenite-containing media. The bacterium metabolized selenite into several protein selenoamino acids such as selenomethionine and selenocysteine/selenocystine, as well as nonprotein selenoamino acids, such as selenocystathionine. Several phosphoamino acids were detected in the presence of elevated levels of selenium. The synthesized protein seems not to be affected by the presence of selenium.

Mobilization of selenium by a selenium-dependent bacterium

A selenium-dependent bacterium, Bacillus sp., failed to grow on selenium-free media. However, it is able to grow at high concentrations of sodium selenite containing media up to 3% (w/v). It accumulated extraordinary high quantities of selenium, 432 ppm/mL. The bacterium generated the transformation of inorganic selenium into volatile selenium form(s) into the atmosphere. The biological release of volatile selenium basically depended on several factors: incubation temperature, pH, incubation periods, and substrate concentration. Maximal quantity of the volatile selenium form was obtained at 30 degrees C, pH 7, and 1% (w/v) sodium selenite.

Incorporation of cadmium into proteins in a cadmium tolerant fungi

Aspergillus carbonarius and a strain of Penicillium, a cadmium tolerant fungi, are able to metabolize cadmium chloride up to 2% (w/v). Their amino acids analysis on cadmium free and cadmium chloride containing media indicated certain disorders in their metabolic activities. Cystathionine was only detected in both fungi in the presence of cadmium chloride. However, cadmium was incorporated into several types of low and high molecular weight proteins. The amino acids hydrolyzates of a cadmium containing protein are characterized by the presence of high levels of sulfur amino acids; cysteine and methionine. Ethylasparagine was detected in the hydrolyzate of that cadmium containing protein as well.

Incorporation of tellurium into amino acids and proteins in a tellurium-tolerant fungi

Aspergillus fumigatus, Aspergillus terreus, and Penicillium chrysogenum, a tellurium tolerant fungi, are able to grow on sulfur free medium amended with 0.2% (w/v) tellurite. Tellurium was incorporated into several types of low and high molecular weight proteins. The newly detected telluro-proteins contained an extraordinary high level of tellurium, as well as telluro-cysteine, telluro-cystine, telluro-methionine, and serine.

Influence of cadmium on certain biological activities in a cadmium-tolerant fungi

Aspergillus carbonarius and a strain of Penicillium are able to grow on Harrold's agar media amended with different concentrations of cadmium chloride up to 2.5% (w/v). Considerable quantities of cadmium were absorbed by both fungi. A. carbonarius absorbed more cadmium than the Penicillium sp. did, under the same culturing conditions. In the presence of cadmium, the determined cellular contents of proteins, lipids, and carbohydrates were extraordinary high, whereas the activities of certain enzymes, lipases, amylases, and proteases were inhibited. The fungal rate of growth and sporulations were mostly suppressed. Conidiations were inhibited at lowest concentrations. At 1% Cd Cl2, A. carbonarius produced malformed conidiophores, whereas the Penicillium sp. was less affected. At higher concentrations conidiophores production were entirely suppressed and several hyphal swellings were produced.

Selenium metabolism in a strain of Fusarium

Fusarium sp. was isolated from Sinai soil at Egypt. It showed tendency to tolerate high concentrations of selenium in the form of sodium selenite up to 3.5% (w/v). The microscopic examination revealed some morphological distortions. However, the fungus was capable to circumvent the toxic effect of selenium. The fungus possess strong reducing ability as high quantities of elemental selenium were precipitated within the fungal cells as well as on the surface of the fungal hyphae and spores. The presence of selenium increased the cellular contents of carbohydrates, proteins, and lipids. Labeling studies indicate the incorporation of selenite into certain amino acids: selenocysteine and selenocysteic acid. Moreover, the presence of selenium induced the biosynthesis of several types of low molecular weight proteins. The results demonstrated different modes of detoxification of selenium toxicity.

Selenoprotein in Aspergillus terreus

Aspergillus terreus, a moderately selenium-tolerant fungus, metabolized Se-selenite into several protein seleno-amino acids: selenomethionine and selenocysteine, as well as, nonprotein seleno-amino acids, selenocystathionine, and y-glutamyl selenomethyl selenocysteine. The results indicate the failure of the fungus to discriminate between sulphur and selenium. Selenium was also incorporated into several proteins of different molecular weights, mostly of low molecular weight proteins. Labeled studies showed the presence of high levels of selenomethionine and selenocysteine in the protein hydrolysate. The actual incorporation of protein seleno-amino acids into the fungal protein was proven. The results demonstrated a finding that detracts from previous held views.