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Biomedical subjects

David Isaacs

Publications and source records attributed to David Isaacs.

At least 19 recordsLinked to original sources
PubMed2006

Antibiotics in childhood pneumonia.

Pneumonia is one of the most common global childhood illnesses. The diagnosis relies on a combination of clinical judgement and radiological and laboratory investigations. Streptococcus pneumoniae remains the most important cause of childhood community-acquired pneumonia. In addition, viruses (including respiratory syncytial virus) and atypical bacteria (Mycoplasma and Chlamydia) are likely pathogens in younger and older children in developed countries. In the minority of cases only, the actual organism is isolated to guide treatment. Antibiotics effective against the expected bacterial pathogens should be instituted where necessary. The route and duration of antibiotic therapy, the role of emerging pathogens and the impact of pneumococcal resistance and conjugate pneumococcal vaccines are also discussed.

Anti-Bacterial Agents↗
PubMed2006

3D fluoroscopy with real-time 3D non-cartesian phased-array contrast-enhanced MRA.

For optimized CE-MRA of the chest and abdomen, the scan time and breath-hold must be coordinated with the arrival of contrast. A 3D fluoroscopy system is demonstrated that performs real-time 3D projection reconstruction acquisition, reconstruction, and visualization using only the standard scanner hardware and operator console workstation. Unlike 2D fluorotriggering techniques, no specification of a monitoring slab or careful placement of the imaging volume is required. 3DPR data are acquired continuously throughout the examination using an eight-channel receiver and 1 s interleaved subframes. The data are reconstructed using 1 s segments for real-time monitoring with 0.8-cm isotropic spatial resolution over the entire torso, allowing full-volume axial, coronal, and sagittal MIPs to be displayed simultaneously with minimal latency. The system later uses the same scan data to generate high-spatial-resolution time-resolved sequences of the breath-hold interval. The 3D fluoroscopy system was validated on phantoms and human volunteers.

Artifacts↗
PubMed2006

Late onset neonatal Gram-negative bacillary infection in Australia and New Zealand: 1992-2002.

BACKGROUND: Late onset neonatal Gram-negative bacillary infection is a significant cause of morbidity and mortality. OBJECTIVE: To determine the incidence and mortality from late onset Gram-negative bacillary infections in neonatal units. METHODS: An 11-year longitudinal prospective surveillance study. Clinicians in 20 neonatal units in Australia and New Zealand collected data. Late onset sepsis was defined as clinical signs of infection starting more than 48 hours after birth, with laboratory evidence supporting sepsis and pure growth of a pathogen from blood and/or cerebrospinal fluid. RESULTS: Overall, 702 of 3113 (22.5%) episodes of late onset sepsis in 681 infants were from Gram-negative bacilli. Overall mortality was 20.8% (142 of 681 infants) and significantly related to maturity, birth weight and infecting organism. Mortality was 25% for infants <30 weeks compared with 11.5% for infants > or =30 weeks gestation (P < 0.0001) and 24.2% for infants with birth weights <1500 g versus 12.7% if > or =1500 g (P < 0.0001). Infection by Pseudomonas aeruginosa was associated with 52.3% mortality (46 of 88 infants), significantly higher than the 13.7% to 23.8% fatality from other Gram-negative bacilli (P < 0.0001). During the surveillance, the late onset Gram-negative bacillary infection rate remained stable at 1.14 per 1000 live births (range 0.87-1.5). Similarly, mortality was unchanged, being 0.25 per 1000 live births (range 0.12-0.43). CONCLUSIONS: Gram-negative bacilli remain important causes of late onset neonatal sepsis, especially among very low birth weight infants, and result in a high mortality, particularly with P. aeruginosa infections.

Age Factors↗
PubMed2006

Attention-deficit/hyperactivity disorder: are we medicating for social disadvantage? (For).

The diagnosis of attention-deficit/hyperactivity disorder (ADHD) is based on well defined criteria, which describe a number of symptoms. It is important to consider the context of the symptoms, in terms of the influence of the child's family and school. Although stimulant medications benefit selected children they may not benefit all children with symptoms of ADHD. The incidence of ADHD increases with social disadvantage. There is a potential danger of using stimulant medication alone to treat children with complex psychosocial problems, associated with social disadvantage, including Aboriginal children. We desperately need better training in the management of ADHD and better access to child psychiatrists.

Attention Deficit Disorder with Hyperactivity↗
PubMed2006

Exposure to open tuberculosis on a neonatal unit.

The mother of a baby on the neonatal intensive care unit was found to have untreated open pulmonary tuberculosis. Tuberculin skin testing and chemoprophylaxis was offered to selected mothers and babies, depending on level of exposure. One of 3 mothers sharing a room with the index mother and 2 of 20 mothers whose babies were on the neonatal unit subsequently converted to tuberculin and were given isoniazid chemoprophylaxis. Isoniazid chemoprophylaxis was given to 13 exposed babies, none of whom tuberculin converted. Two babies were treated empirically for tuberculosis.

Adult↗
PubMed2006

Annual report: Surveillance of adverse events following immunisation in Australia, 2005.

This report summarises Australian passive surveillance data for adverse events following immunisation (AEFI) reported to the Adverse Drug Reactions Advisory Committee for 2005, and describes reporting trends over the six year period 2000 to 2005. There were 839 AEFI records for vaccines received in 2005. This is an annual AEFI reporting rate of 4.1 per 100,000 population, the lowest since 2000 and a 22 per cent decrease compared with 2004 (1,081 records; 5.4 AEFI records per 100,000 population). The decrease was not consistent across age groups. Reporting of AEFI increased for children aged <1 year in 2005 (60.7 versus 50.3 per 100,000 population) and decreased for the 7 to <20 year age group (0.9 versus 8.9 per 100,000 population). Dose-based AEFI reporting rates in 2005 were 11.0 per 100,000 doses of scheduled vaccines for children aged <7 years and 2.0 per 100,000 doses of influenza vaccine for adults aged >18 years. The majority of records described non-serious events while 9 per cent (n=72) described AEFIs defined as serious. There was one report of death in an older person following influenza vaccine and one of non-polio acute flaccid paralysis in an infant, both temporally associated with immunisation. The most frequently reported individual AEFI was injection site reaction in children following a fifth dose of diphtheria-tetanus-acellular pertussis vaccine (79 reports per 100,000 doses). The increase in the population-based AEFI reporting rate for children aged <1 year in 2005 coincided with the introduction of national immunisation programs for conjugate pneumococcal vaccine in January 2005 and inactivated poliovirus vaccine in November 2005. The fall in reporting rates for older children and adolescents follows the completion of the national meningococcal C catch-up program in early 2005. The consistently low reporting rate of serious AEFIs demonstrates the high level of safety of vaccines in Australia.

Adverse Drug Reaction Reporting Systems↗
PubMed2005

Reporting of adverse events following immunization in Australia.

It is an important component of any immunization programme that vaccine safety is monitored by carrying out surveillance for adverse events following immunization (AEFI). Such surveillance can be active or passive. Active surveillance will detect more AEFI, but the vast majority will be minor events. Passive surveillance is probably more appropriate for routine AEFI surveillance, while active surveillance can be used to monitor a new vaccine or to test whether a specific severe event is significantly associated with immunization. Australia has a predominantly passive surveillance system. The system has recently been centralized, providing useful national data on vaccine safety.

Adverse Drug Reaction Reporting Systems↗
PubMed2005

Rebecca's story.

Explore the source record for details and available documents.

Adult↗
PubMed2005

Annual report: surveillance of adverse events following immunisation in Australia, 2004.

This report summarises Australian passive surveillance data on adverse events following immunisation (AEFI) for 2004 and describes reporting trends over the five years, 2000 to 2004. AEFIs are notified to the Adverse Drug Reactions Advisory Committee by state and territory health departments, hospitals, doctors and other health providers, vaccine manufactures, and the public. There were 975 AEFI records for vaccines received in 2004. This is an annual AEFI reporting rate of 4.8 per 100,000 population, the lowest since 2000, and a 33 per cent decrease compared with 2003 (1,460 records; 7.1 AEFI records per 100,000 population). Dose-based AEFI reporting rates in 2004 were 1.8 per 100,000 doses of influenza vaccine for adults aged > or = 18 years and 11.8 per 100,000 doses of scheduled vaccines for children aged < 7 years. The majority of records described non-serious events while nine per cent (n = 88) described AEFIs defined as 'serious'. There were no reports of death related to immunisation. The most frequently reported individual AEFI was injection site reaction in children following a fifth dose of an acellular pertussis-containing vaccine (67 reports per 100,000 doses). The marked reduction in the AEFI reporting rate in 2004 coincided with the removal of the fourth dose of acellular pertussis vaccine, due at 18 months of age, from the vaccination schedule in September 2003 and fewer people receiving meningococcal C vaccine through the national catch-up vaccination program for those aged 1-19 years in 2004, compared with 2003. The consistently low reporting rate of serious AEFIs demonstrates the high level of safety of vaccines in Australia.

Adolescent↗
PubMed2004

The effects of enrofloxacin on decorin and glycosaminoglycans in avian tendon cell cultures.

Tendonitis and tendon rupture have been reported to occur during or following therapy with fluoroquinolone antibiotics. Though the pathogenesis is unknown, several studies suggest that fluoroquinolone antibiotics alter proteoglycan content in soft tissues, including tendons, and thereby alter collagen fibrillogenesis. To better understand the mechanism of action of fluoroquinolones, we studied the effects of enrofloxacin, a widely used fluoroquinolone in veterinary medicine, on avian tendon cell cultures established from gastrocnemius tendons from 18-day-old chicken embryos. We found that cell proliferation was progressively inhibited with increasing concentrations of enrofloxacin. This was accompanied by changes in morphology, extracellular matrix content and collagen fibril formation as detected by electron microscopy. We also observed a 35% decrease in the content of total monosaccharides in enrofloxacin-treated cells. The ratio of individual monosaccharides was also altered in enrofloxacin-treated cells. Enrofloxacin also induced the synthesis of small amounts of keratan sulfate in tendon cells. Moreover we observed enrofloxacin-induced changes in glycosylation of decorin, the most abundant tendon proteoglycan, resulting in the emergence of multiple lower molecular bands that were identifiable as decorin after chondroitinase ABC and N-glycanase treatment of extracts from enrofloxacin-treated cells. Medium conditioned by enrofloxacin-treated cells contained less decorin than did medium conditioned by control cells. We hypothesize that enrofloxacin induces either changes in the number of N-linked oligosaccharides attached to the core protein of decorin or changes in decorin degradation process. In conclusion, our data suggest that enrofloxacin affects cell proliferation and extracellular matrix through changes in glycosylation.

Animals↗