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Biomedical subjects

R Bowman

Publications and source records attributed to R Bowman.

At least 19 recordsLinked to original sources
PubMed2006

Why we need a population-based approach to clinical indicators for cancer: a case study using microscopic confirmation of lung cancer in Queensland.

An important function of clinical cancer registries is to provide feedback to clinicians on various performance measures. To date, most clinical cancer registries in Australia are located in tertiary academic hospitals, where adherence to guidelines is probably already high. Microscopic confirmation is an important process measure for lung cancer care. We found that the proportion of patients with lung cancer without microscopic confirmation was much higher in regional public hospitals (27.1%) than in tertiary hospitals (7.5%), and this disparity remained after adjusting for age, sex and comorbidities. The percentage was also higher in the private than in the public sector. This case study shows that we need a population-based approach to measuring clinical indicators that includes regional public hospitals as a matter of priority and should ideally include the private sector.

Academic Medical Centers↗
PubMed2005

Delay in presentation to hospital for surgery for congenital and developmental cataract in Tanzania.

BACKGROUND: Childhood cataract is a leading cause of blindness in children in eastern Africa. High quality surgical services have been established at a few tertiary facilities in the region; however, there appears to be delay in presentation to hospital. METHODS: Parents or guardians of all children presenting to KCMC Hospital or CCBRT Hospital with congenital (recognised since birth or within the first year) or developmental (cataract leading to reduction in vision after 1 year of age) cataract were interviewed regarding the actions taken (and timing of these) before coming to hospital. Demographic information was also collected. For analysis children were grouped as either late presenters (more than 12 months after recognition) or not late presenters (within 12 months of recognition) and predictors of late presentation were assessed. RESULTS: Among 178 children (74 congenital cataract and 104 developmental cataract) analysed, the mean delay between recognition by the caregiver and presentation to hospital was 34 months, almost 3 years. The median delay was 18 months-9 months for congenital cataract and 24 months for developmental cataract. Long delay in presentation was associated with having developmental cataract, living far from the hospital, and low socio-educational status of the mother. Among children with congenital cataract, having another sibling increased the likelihood of early presentation. CONCLUSION: Delay in presentation remains a significant problem for children needing surgery for congenital or developmental cataract. Parents who have multiple children may be more likely to seek early treatment, possibly because their expectations of achievable sight at a young age are based on previous experience of their older children. Educational efforts should aim to reach the most "unreachable" (those living the furthest from the hospital and having the lowest socio-educational status of the mother).

Cataract↗
PubMed2004

A double-blind randomized controlled trial investigating the effectiveness of topical bupivacaine in reducing distress in children following extractions under general anaesthesia.

OBJECTIVE: This study was designed to investigate the effectiveness of topical bupivacaine (0.25%) in reducing postoperative distress following extraction of teeth under general anaesthesia in children. DESIGN: The study was a double-blind randomized controlled trial. SETTING: The study was conducted in a dental hospital. SAMPLE: The sample comprised 135 children aged between 2 and 12 years of age who were undergoing outpatient general anaesthesia for simple dental extractions. METHODS: The children were randomly allocated to one of two groups: the bupivacaine group (the study group) comprised 68 children whilst the sterile water group (the control group) comprised 67. Following the extraction of their teeth, children had swabs soaked in the appropriate solution placed over the exposed teeth sockets. A five-point face scale was employed by an independent observer to evaluate the distress for each child. Evaluation of distress was made preoperatively, on recovery from the general anaesthetic, and again, 15 min following recovery from the anaesthetic. RESULTS: There were no statistically significant differences between the mean distress scores for the bupivacaine and sterile water groups preoperatively, postoperatively or 15 min postoperatively. For both groups, however, there were significant increases in distress scores between the preoperative and 15 min postoperative assessment scores. CONCLUSION: Extraction of teeth under general anaesthesia does cause distress in children. There is no evidence that topical bupivacaine reduces this distress when compared to sterile water.

Ambulatory Surgical Procedures↗
PubMed2000

Visual prognostic value of the pattern electroretinogram in chiasmal compression.

BACKGROUND/AIMS: The visual loss associated with compression of the optic chiasm by pituitary tumours may be transient or permanent, possibly related to the extent of irreversible retrograde degeneration to the retinal ganglion cells. The pattern electroretinogram (PERG) N95 component is thought to rise in relation to retinal ganglion cell function and hence may be a potential prognostic indicator for visual function following decompressive surgery. METHODS: The notes and electrodiagnostic records of 72 eyes from 36 patients with chiasmal compression were retrospectively analysed. RESULTS: The postoperative change in visual field was found to be associated with the PERG N95:P50 ratio (p=0.01). Improvement in visual field was shown by a greater proportion of eyes with a normal N95:P50 ratio (65%) than with an abnormal ratio (27%). No change in visual field occurred in 26% of the eyes with a normal N95:P50 ratio compared with 67% of those with an abnormal ratio. Only 8% of eyes showed a worsening of visual field following surgery, in similar proportions for eyes with normal and abnormal N95:P50 ratios. There was no significant relationship with visual acuity. CONCLUSION: The PERG is a useful visual prognostic indicator in the preoperative assessment of chiasmal compression.

Adult↗
PubMed1998

Lack of evidence for systemic toxicity following topical chloramphenicol use.

There has been considerable controversy regarding the safety of topical chloramphenicol in ophthalmic practice. The evidence for associated haematopoietic toxicity in idiosyncratic and dose-dependent forms was reviewed. The 7 cases of idiosyncratic haematopoietic reactions associated with topical chloramphenicol reported in the literature are refutable evidence for the existence of such a response. In Scotland, despite extensive prescription of topical chloramphenicol, the incidence of acquired aplastic anaemia was found to be low, as were associated reports of blood dyscrasias throughout the UK. The epidemiology of acquired aplastic anaemia failed to make an association with topical chloramphenicol use. High-performance liquid chromatography (minimum detection limit 1 mg/l) was used to investigate whether serum accumulation of chloramphenicol occurred after topical therapy in 40 patients. The mean dose of chloramphenicol eye drops used after 1 week of treatment was 8.0 mg, and after 2 weeks, 15.3 mg. As expected, chloramphenicol failed to accumulate to detectable levels. This supported the view that topical chloramphenicol was not a risk factor for inducing dose-related bone marrow toxicity. Calls for the abolition of treatment with topical chloramphenicol based on current data are not supported.

Adult↗
PubMed1996

The fiberoptic intraparenchymal cerebral pressure monitor in 244 patients.

BACKGROUND: The fiberoptic intraparenchymal pressure monitor has been shown to provide reliable data in patients monitored for a short period of time. An analysis of a large population, including patients monitored for a prolonged period such as weeks, has never been performed. METHODS: We conducted a retrospective study in which we evaluated the fiberoptic intraparenchymal cerebral pressure monitor for complications and accuracy. RESULTS: The fiberoptic intraparenchymal cerebral pressure (ICP) monitor was used in 244 patients since 1988. Pathology included trauma in 180, intracerebral hemorrhage (ICH) in 19, aneurysmal subarachnoid hemorrhage in 16, arteriovenous malformations in 10, cerebral edema in 12, and tumor in 7. The mean length of monitoring was 7 days with 49 patients (20%) monitored 1-2 days, 105 (43%) monitored 3-6 days, 48 monitored for 7-10 days (20%), and 42 (17%) monitored from 10-24 days. Seventy-four patients also had ventriculostomies and there was strong correlation with the ICP monitor (p < 0.001). Complications from insertion were 2 patients (0.8%) with ICH, both with hepatic dysfunction. In the group monitored greater than 6 days, 34 patients (38%) required at least one catheter change due to upward drift of the ICP. Fiberoptic breakage requiring replacement was documented in 41 patients (16%). An insertion-site infection occurred in one case monitored for 23 days. Two infected bone flaps occurred that had a monitor placed in the flap. There were no cases of bacterial meningitis or cerebral abscess. CONCLUSIONS: The monitor is easy, safe, and reliable to use with a very low rate of infection. Coagulopathic patients may best be monitored by an alternative method.

Brain Edema↗
PubMed1996

In vitro bacterial adherence to hydrogel and poly(methyl methacrylate) intraocular lenses.

PURPOSE: To compare the in vitro adherence of Staphylococcus epidermidis to poly-(hydroxyethyl methacrylate) (polyHEMA) or hydrogel intraocular lenses (IOLs) and poly(methyl methacrylate) (PMMA) IOLs. SETTING: Lions Eye Institute, Perth, Western Australia. METHODS: One-piece hydrogel lenses and one-piece PMMA lenses were suspended for 60 minutes in standardized suspensions of a well-characterized strain of S. epidermidis and then sonicated in a known quantity of balanced salt solution to remove the adherent bacteria. Quantitative cultures of the sonicates were performed and the results analyzed statistically. RESULTS: The mean bacterial adherence of S. epidermidis to the PMMA IOLs (58,400 CFU) was more than 20 times greater than that to the hydrogel IOLs (1953 CFU). The difference was statistically significant (P < .001). CONCLUSIONS: Adherence of S. epidermidis to hydrogel IOLs is significantly lower than to PMMA IOLs. This suggests that the risk of postoperative endophthalmitis after cataract extraction and IOL implantation may be lower with the use of hydrogel IOLs.

Bacterial Adhesion↗
PubMed1996

Intraocular pressure changes after peribulbar injections with and without ocular compression.

AIM: Two prospective studies were carried out in order to investigate (1) the rise in intraocular pressure (IOP) following peribulbar anaesthesia with a fixed volume of anaesthetic agent administered by a single surgeon, and (2) the efficacy of ocular compression with the Honan balloon for lowering IOP. Glaucomatous eyes were excluded from both studies. METHODS: In study group 1, 36 eyes of 36 patients undergoing cataract and/or implant surgery each received peribulbar injections consisting of 5 ml of anaesthetic from an inferotemporal site through the conjunctiva and a further 5 ml from a medial injection through the caruncle. IOP values were measured immediately before and after the injections and then after a variable period of external ocular compression. In study group 2, 20 eyes of 20 patients undergoing cataract surgery received peribulbar injections of local anaesthetic as above. IOP values were measured immediately before and after the injections and after 20 minutes without ocular compression. After a further 20 minute period with ocular compression the IOP was again measured. RESULTS: In study group 1, the mean immediate rise in IOP induced by the injections was 11.44 (95% confidence interval 8.97-13.90) mm Hg. The mean change in IOP after ocular compression was an overall fall of 2.42 (0.49-4.34) mm Hg from the pre-injection value. In study group 2, the mean injection induced rise in IOP was 9.45 (6.90-12.00) mm Hg. The mean fall in IOP during the first 20 minutes without ocular compression was 2.85 (1.20-4.50) mm Hg. During the second 20 minutes with ocular compression the mean fall in intraocular pressure was 11.05 (8.14-14.96) mm Hg. CONCLUSIONS: There is a large and individually variable rise in IOP following peribulbar anaesthesia. Ocular compression with the Honan balloon is effective in reversing this rise even when the initial rise is large.

Anesthesia, Local↗
PubMed1995

Polymerase chain reaction for the detection of toxigenic Corynebacterium diphtheriae.

Several conventional methods have been described for the detection of Corynebacterium diphtheriae toxin, including Elek immunodiffusion, tissue culture using VERO cells and guinea pig inoculation. All these methods have the disadvantage of being either slow to complete or technically demanding, particularly when performed infrequently. We examined 64 strains of C. diphtheriae by PCR and Elek immunodiffusion, and strains showing a positive result in either assay were inoculated into guinea pigs. Seven isolates were positive in both Elek and PCR assays and subsequently positive in guinea pig inoculation assay. One isolate was negative in Elek testing but positive in PCR assay and guinea pig inoculation. All other isolates were negative in both Elek and PCR assays. The PCR assay is rapid with cycling and detection complete within 3-4 hrs of receipt of strains. PCR has now become the routine method for detection of C. diphtheriae toxin in our laboratory.

Animals↗
PubMed1995

Comparison between image and flow cytometry. A priori factors that influence technique.

Comparisons between flow cytometry (FCM) and image cytometry (ICM) have found a high concordance rate in pancreatic tissue, with some discrepancies between the two procedures. This study utilized 40 cases of chronic pancreatitis, primary pancreatic adenocarcinoma and metastatic pancreatic adenocarcinoma to determine the concordance rate between the two procedures. The reasons for discrepancies were identified and subsequently used to establish methods for a priori determination of which procedure to use. Using the FACSCAN flow cytometer and the CAS 200 on appropriately stained specimens that were disaggregated from 50-micron sections, we achieved a concordance rate of r = .878 (P < .01) after removing outliers. Thirty-one of 40 cases matched DNA content, and 9 cases had discrepant results. These discrepant cases were evaluated with factor analysis, in part because initial observations suggested that the variables evaluated could be combined into unifying concepts. The nine measured variables were compressed into three factors, which accounted for 68% of the variation observed between the two methods. Readily evaluated features, on a case-by-case basis, including tumor/nontumor ratios, accounted for the largest proportion of this variation. These findings suggest that tumor/nontumor cell ratios in hematoxylin-eosin-stained sections may provide adequate a priori information to direct the choice of either FCM or ICM to measure DNA ploidy in pancreatic tissue.

Adenocarcinoma↗