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Biomedical subjects

B B Jalaludin

Publications and source records attributed to B B Jalaludin.

12 recordsLinked to original sources
PubMed2005

Technology enhancements and changes in radiotherapy throughput in New South Wales.

AIMS: To assess the effect that the age of linear accelerators and recent changes in technology have had on linear accelerator throughput in New South Wales, Australia. MATERIALS AND METHODS: Duration was measured (time of patient entry into the treatment room to time of exit) of each radiotherapy treatment fraction delivered on each linear accelerator over a 5-day period. Patient-, treatment- and equipment-based variables were collected for all treatment fractions, and assessed for their effect on fraction duration. Comparisons were made between these data and similar productivity data collected from a study carried out in 1996. Since the sample sizes for both the study periods were large enough, the distributions of the means were assumed normal (Central Limit Theorem). Specific analyses were carried out to assess the affect that new technologies, such as automatic field-sequencing (AFS) and multi-leaf collimator (MLC), have had on fraction duration. RESULTS: A total of 12 892 treatment fields and 4316 treatment fractions were delivered on 27 linear accelerators over 135 days. Comparison between the 2003 and 1996 productivity data showed an increase in the mean number of patients treated per hour by 11% and fields treated per hour by 31%. The mean number of fields treated per fraction increased by 15%. The mean fraction duration was reduced by 13% for linear accelerators of less than the median age of 7 years that were equipped with MLC/AFS, or both, compared with older linear accelerators without AFS and MLC. This reduction was more obvious for complex techniques, such as four-field breast treatments (27% decrease in fraction duration). The mean number of fields treated per hour was 43% more on the newer machines equipped with AFS and MLC. CONCLUSIONS: An increase in productivity has been observed between the 1996 and 2003 study periods, as measured by patients or fields per hour, despite an increase in treatment complexity as measured by fields per fraction. The application of AFS and MLC, and the use of newer linear accelerators, significantly shortened the mean duration per fraction for the common treatment techniques.

Hospital Departments↗
PubMed2005

The development of a new basic treatment equivalent model to assess linear accelerator throughput.

AIMS: The basic treatment equivalent (BTE) model was developed in 1996 in an attempt to improve the measurement of linear accelerator throughput in radiotherapy. This study aimed to assess the effect of treatment set-up and patient characteristics on fraction duration, to update the BTE model and to determine the better throughput measure between fields per hour and BTE per hour. MATERIALS AND METHODS: Stopwatch measurements of the duration of each radiotherapy treatment fraction delivered on each linear accelerator in participating New South Wales radiation oncology departments over a 5-day period in 2003 were undertaken. Patient, equipment and staff data were collected to assess the effect of these variables on fraction duration. A new BTE equation was derived, including the most significant variables. Statistical comparison of fields and BTE per unit time was made to assess the better predictor of fraction duration. RESULTS: Data collected on 27 linear accelerators in 13 departments included a total of 135 days of linear accelerator operation, 4316 fractions and 12 892 treatment fields. Seventeen factors significantly influenced fraction duration (P < 0.01). These accounted for 46% of the total variance in the models. The eight most influential predictors of prolonged fraction duration were included in the BTE model. These were as follows: high number of fields, high number of port films/electronic portal imaging, absence of automatic field-sequencing and multi-leaf collimation, high number of junctions, use of bolus and first fraction of a treatment course. The BTE per hour was shown to be a better predictor of throughput than fields per hour. CONCLUSIONS: The BTE model is a better measure of linear accelerator throughput. It incorporates weightings for treatment and patient factors that significantly influenced fraction duration. This measure could be routinely collected by the radiation oncology departments and included in the electronic radiotherapy information systems.

Data Collection↗
PubMed2001

Non-multiresistant and multiresistant methicillin-resistant Staphylococcus aureus in community-acquired infections.

OBJECTIVE: To survey Staphylococcus aureus strains isolated from patients presenting from the community, comparing clinical features and antibiotic sensitivity profiles between multiresistant and non-multiresistant methicillin-resistant and methicillin-sensitive isolates. DESIGN: Retrospective case series. PARTICIPANTS AND SETTING: Patients who presented to emergency or dermatology departments in hospitals served by the South Western Sydney Area Health Service between 1 May 1998 and 30 April 1999. All patients with methicillin-resistant S. aureus (MRSA) and the first 100 with methicillin-sensitive S. aureus were eligible. MAIN OUTCOME MEASURES: Patient demographic characteristics; risk factors; clinical presentation; treatment; outcome; and isolate antibiotic susceptibility. RESULTS: 139 patients were eligible, and 122 had clinical records available. Ten of these 122 (8%) had multiresistant MRSA, 26 (21%) non-multiresistant MRSA and 86 (70%) methicillin-sensitive S. aureus. Among patients with non-multiresistant MRSA, 29% (7/24) were born in New Zealand, Samoa or Tonga, a higher proportion than among those with multiresistant MRSA or methicillin-sensitive S. aureus (P= 0.03). Nearly half (44%) of non-multiresistant MRSA strains were community-acquired in patients with no risk factors. Two-thirds of patients with non-multiresistant MRSA (17/26) presented with cellulitis or abscess, and 58% (11/19 evaluable patients) required surgical treatment. CONCLUSIONS: Non-multiresistant MRSA strains are common, especially among people born in New Zealand, Samoa or Tonga, and are usually community acquired. Medical practitioners should routinely swab all staphylococcal lesions for culture and sensitivity.

Adult↗
PubMed2001

Epidemiology of asthma in children. Who gets asthma and why?

BACKGROUND: Asthma is a common disease in childhood which results in a substantial burden of illness in Australia. This is manifest by distressing symptoms, impact on quality of life and role performance and health service utilisation. OBJECTIVE: This article reviews the current literature on the epidemiology of asthma in children. It particularly focuses on the prevalence, trends in prevalence, risk factors and causes of asthma. The emphasis is on common questions that parents of children with asthma would like answered by their general practitioners. DISCUSSION: We know something about some of the risk factors for asthma and a little about the mechanisms for the development of asthma. Despite the paucity of knowledge about the causes of asthma, some positive steps can be taken to prevent it. Allergic or asthmatic parents, whose children have a high risk of developing asthma, can be advised to avoid smoking during pregnancy and avoid environmental tobacco smoke exposure after the child is born, to undertake house dust mite control strategies, to breastfeed their babies for at least three months and subsequently to provide their child with a nutritious, balanced diet.

Asthma↗
PubMed2000

A randomized trial of two acellular pertussis vaccines (dTpa and pa) and a licensed diphtheria-tetanus vaccine (Td) in adults.

A single blinded randomized controlled trial to compare the reactogenicity and immunogenicity of adult formulated dTpa and monovalent pa vaccines with a licensed Td vaccine. Five hundred and forty-eight healthy adults aged 19-70 years received a single injection of dTpa or separate injections of pa or Td (with the alternate vaccine 1 month later). Local and systemic reactions were monitored for 15 days after each vaccination. Serum antibody levels were measured immediately prior to and 1 month after vaccination. Antibody levels were measured 12 months after vaccination in 100 subjects. There was no difference in the total frequency of symptoms and signs between subjects receiving any of the three vaccines. There was a significantly lower incidence of local reactions following pa (60%) than dTpa (80%, P=0.002) or Td (93%, P=0.0008). The incidence of clinically significant (Grade 2 or 3) swelling (> or =20 mm) was higher for Td (20%, P=0.002) than for dTpa (11%) or for pa (2%), however, there were no other significant differences in the incidence of Grade 2 or 3 reactions between the vaccines. A high anti-pertussis seroconversion rate (>97%) against all the studied pertussis antigens was seen 1 month after vaccination with dTpa and pa. A total of 96 and 99% of subjects receiving dTpa and Td, respectively, had anti-diphtheria titres > or =0.01 IU/ml, and all but one subject had anti-tetanus titres > or =0.1 IU/ml after 1 month. Twelve months after vaccination the majority (90-100%) of the subjects were still seropositive for each antigen and although GMTs had decreased they were substantially higher than pre-vaccination levels. The dTpa vaccine was well tolerated and capable of eliciting an immune response against all the antigens in a broad spectrum of the adult population and could potentially replace Td for routine boosters in adults.

Adhesins, Bacterial↗
PubMed2000

Use of "preventer" medications and written asthma management plans among adults with asthma in New South Wales. NSW Health Department Asthma Data Working Group.

OBJECTIVES: (1) To measure the extent of use of preventer medications (ie, inhaled corticosteroids or cromones) and possession of written asthma management plans (AMPs) among people with asthma in New South Wales in 1997. (2) To assess factors associated with underuse of preventer medications and AMPs. DESIGN AND SETTING: A cross-sectional survey by computer-assisted telephone interviews of a stratified random sample of the adult population of New South Wales, Australia. PARTICIPANTS: People aged 16 to 54 years with asthma diagnosed by a doctor and causing symptoms or requiring treatment in the preceding year (n = 1,372). RESULTS: Although 55.2% of survey participants had used preventer medications in the preceding year, only 27.8% had used them regularly. Only 34.7% had a written AMP. Preventer medications were judged to be indicated for 54% of the study population, but only 42.5% of this group had used them regularly (43.1% had a written AMP). Younger adults were less likely to use preventer medications regularly, but there was no difference in use of preventer medications by sex, urban/rural residence, or manner of purchasing reliever medications (either on prescription or "over the counter"). Past smokers used preventers more commonly than current smokers, with never smokers having an intermediate prevalence of regular preventer use. Age, sex, urban/rural residence, and manner of purchasing reliever medications were not related to the possession of an AMP. CONCLUSION: Despite the trend towards increased use of preventer medications and written AMPs during the 1990s, undertreated asthma remains a major public health problem in Australia.

Adolescent↗
PubMed2000

Survey of pertussis morbidity in adults in western Sydney.

OBJECTIVE: To estimate morbidity due to Bordetella pertussis infection in a representative population of Australian adults. DESIGN: Telephone survey using structured questionnaire. PARTICIPANTS: Adults (aged 20 years and over) notified with pertussis to a public health unit in western Sydney between 1 December 1997 and 31 May 1998. MAIN OUTCOME MEASURES: Duration of cough; time to improvement; symptoms and complications; time to diagnosis; health resource use; lost work days. RESULTS: Of 90 eligible patients, 73 (81%) completed questionnaires. Cough lasted a median of 60 days, but persisted over 90 days in 20 people (27%). Presentation was within a median of seven days of symptom onset, but diagnosis of pertussis took a median of 21 days. Participants reported a mean of 3.7 general practitioner visits and 1.2 prescription drugs. Of those employed, 17 (35%) missed more than five work days (range, 0-93 days). CONCLUSIONS: B. pertussis infection in adults can result in prolonged, significant disruption to social and working life. Results suggest that, in 1998, there were more than 8000 general practitioner visits and 15,000 lost work days caused by pertussis in Australian adults.

Adult↗
PubMed2000

Acute effects of low levels of ambient ozone on peak expiratory flow rate in a cohort of Australian children.

BACKGROUND: We enrolled a cohort of primary schoolchildren with a history of wheeze (n = 148) in an 11-month longitudinal study to examine the relationship between ambient ozone concentrations and peak expiratory flow rate. METHODS: Enrolled children recorded peak expiratory flow rates (PEFR) twice daily. We obtained air pollution, meteorological and pollen data. In all, 125 children remained in the final analysis. RESULTS: We found a significant negative association between daily mean deviation in PEFR and same-day mean daytime ozone concentration (beta-coefficient = 0.88; P = 0.04) after adjusting for co-pollutants, time trend, meteorological variables, pollen count and ALTERNARIA: count. The association was stronger in a subgroup of children with bronchial hyperreactivity and a doctor diagnosis of asthma (beta-coefficient = -2.61; P = 0.001). There was no significant association between PEFR and same-day daily daytime maximum ozone concentration. We also demonstrated a dose-response relationship with mean daytime ozone concentration. CONCLUSIONS: Moderate levels of ambient ozone have an adverse health effect on children with a history of wheezing, and this effect is larger in children with bronchial hyperreactivity and a doctor diagnosis of asthma.

Air Pollutants↗
PubMed1999

Risk factors for asthma deaths: a population-based, case-control study.

OBJECTIVES: To investigate risk factors for death from asthma using a case-control study design with two control groups. METHODS: Cases (n = 42) comprised subjects aged 10-59 years who died from asthma. Two control groups were selected: a random sample of asthmatics from the community (n = 132) and age and sex matched patients recently admitted to hospital for asthma (n = 89). We obtained information from proxies of cases and controls, and their general practitioners, by a structured telephone survey. Matched and unmatched logistic regression analyses were used to determine odds ratios for risk factors for asthma deaths. RESULTS: Compared to community controls, important risk factors for asthma deaths included indicators of asthma severity, use of three or more groups of asthma medications, more extensive use of health services for asthma, poor compliance with asthma medications and regularly missing hospital and general practitioner appointments for asthma. Compared to hospital controls, risk factors for asthma deaths were previous visits to emergency department for asthma, knowledge about asthma medications and regularly missing general practitioner appointments. CONCLUSIONS: In this study, severity of asthma, increased health service utilisation and suboptimal asthma self-management were associated with increased risks for asthma death. IMPLICATIONS: People with severe asthma or poorly controlled asthma have a greater risk of dying from their asthma. Both clinicians and non-clinicians managing asthma should regularly assess the appropriateness of management to prevent deaths.

Adolescent↗