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Biomedical subjects

M Bartlett

Publications and source records attributed to M Bartlett.

At least 19 recordsLinked to original sources
PubMed2002

Survey of faecal parasites in patients from western Kenya.

Faecal specimens were collected from patients complaining of diarrhoea and abdominal or epigastric discomfort at two hospitals. Information obtained by questionnaires completed at the time of specimens collection, included demographic and clinical data. Specimens were preserved in 10% formalin and polyvinyl alcohol (PVA) and examined, as wet mounts and stained with Wheatley's Trichrome, Weber, modified acid-fast and hot safranin stains. One hundred patients were examined, in 30 of them parasites were detected. The most common organism identified was Cryptosporidium parvum, in specimens of five patients, followed by Entamoeba histolytica/E. dispar in four patients. The recently described "emerging parasites" were detected. Helminth eggs were found in two patients only. HIV status was not known for most of the patients, and the parasites commonly proliferate in the immuno-compromised individuals were not frequently found.

AIDS-Related Opportunistic Infections↗
PubMed2001

Optimal susceptibility testing conditions for detection of azole resistance in Aspergillus spp.: NCCLS collaborative evaluation. National Committee for Clinical Laboratory Standards.

The most important role of susceptibility testing is to identify potentially resistant isolates for the agent being evaluated. Standard testing guidelines recently have been proposed for antifungal susceptibility testing of filamentous fungi (molds). This collaborative (eight centers) study evaluated further newly proposed guidelines (NCCLS, proposed standard M38-P, 1998) and other testing conditions for antifungal susceptibility testing of Aspergillus spp. to itraconazole and three new triazoles, posaconazole (SCH56592), ravuconazole (BMS-207147), and voriconazole. MICs of itraconazole, posaconazole, ravuconazole, and voriconazole for 15 selected isolates of three species of Aspergillus (A. fumigatus, A. flavus, and A. terreus) with well documented in vitro, clinical, or animal data were determined in each center by using four medium formulations (standard RPMI-1640 [RPMI], RPMI with 2% dextrose, antibiotic medium 3 [M3], and M3 with 2% dextrose) and two criteria of MIC determination (complete [MIC-0s] and prominent [MIC-2s] growth inhibition) at 24, 48, and 72 h. The highest reproducibility (92 to 99%) was seen with the standard RPMI and M3 media. Moreover, the distinction between itraconazole-resistant (MICs of >8 microg/ml for clinically resistant strains) and -susceptible (MICs of 0.03 to 1 microg/ml) isolates, as well as between a voriconazole-resistant laboratory mutant and other isolates (voriconazole MICs of 2 to >8 versus 0.12 to 2 microg/ml), was more consistently evident with the standard RPMI medium and when MIC-0s were determined at 48 h. These results provide further refinement of the testing guidelines for susceptibility testing of Aspergillus spp. and warrant consideration for inclusion in the future NCCLS document M38-A.

Antifungal Agents↗
PubMed2001

Lyme borreliosis in rhesus macaques: effects of corticosteroids on spirochetal load and isotype switching of anti-borrelia burgdorferi antibody.

Experimental Borrelia burgdorferi infection of rhesus monkeys is an excellent model of Lyme disease and closely parallels the infection in humans. Little is known about the interaction of host immunity with the spirochete in patients with chronic infection. We hypothesized that rapid development of anti-B. burgdorferi antibody in immunocompetent nonhuman primates (NHPs) is the major determinant of the reduction of the spirochetal load in Lyme borreliosis. This hypothesis was tested by measurement of the spirochetal load by PCR in association with characterization of the anti-B. burgdorferi humoral immune response in immunocompetent NHPs versus that in corticosteroid-treated NHPs. Although anti-B. burgdorferi immunoglobulin G (IgG) antibody was effectively inhibited in dexamethasone (Dex)-treated NHPs, anti-B. burgdorferi IgM antibody levels continued to rise after the first month and reached levels in excess of IgM levels in immunocompetent NHPs. This vigorous production of anti-B. burgdorferi IgM antibodies was also studied in vitro by measurement of antibody produced by B. burgdorferi-stimulated peripheral blood mononuclear cells. Despite these high IgM antispirochetal antibodies in Dex-treated NHPs, spirochetal loads were much higher in these animals. These data indicate that Dex treatment results in interference with isotype switching in this model and provide evidence that anti-B. burgdorferi IgG antibody is much more effective than IgM antibody in decreasing the spirochetal load in infected animals.

Animals↗
PubMed2000

Development and evaluation of a molecular viability assay for Pneumocystis carinii.

Despite recent declines in incidence, Pneumocystis carinii pneumonia (PCP) remains the most commonly occurring opportunistic illness among persons with AIDS in the United States. While P. carinii DNA has been detected in patient respiratory specimens and in air samples collected from various indoor environments housing PCP patients, the viability of these organisms is unknown. For this reason, we have developed and evaluated a molecular viability assay for P. carinii. This method is based upon the detection of P. carinii mRNA by a reverse transcription-PCR that employs specific primers from a member of the heat shock protein 70 family. Under optimal assay conditions, these primers were capable of detecting as few as 100 viable trophozoites as determined by ethidium bromide staining, while no signal was obtained from 10(6) trophozoites killed by heat, desiccation, or UV radiation. This assay was also capable of distinguishing P. carinii from other common fungi present in the air. Therefore, this molecular viability assay may be useful in conjunction with standard bioaerosol collection devices and procedures for the detection of viable P. carinii collected from various indoor environments. It may also be useful in confirming the presence of viable trophozoites in respiratory specimens collected by noninvasive techniques from putatively infected individuals.

Air Pollution, Indoor↗
PubMed2000

Combined optical and fluorescence imaging for breast cancer detection and diagnosis.

In this article, we present a novel approach that combines the best aspects of both endogenous optical imaging and exogenous fluorescent lifetime and yield imaging for breast cancer detection and diagnosis. Using this approach, spatial distributions of optical properties, fluorescence lifetime, and yield in tissue can be reconstructed from measured excitation and emission data at the surface of the breast tissue by regularized inverse algorithms. We show images from simulated data, as well as images from experimental data using tissue-like phantom materials in the laboratory.

Algorithms↗
PubMed2000

A cluster of leptospirosis among abattoir workers.

In early December 1998, the Northern Rivers Public Health Unit (north-eastern New South Wales) was alerted to a possible cluster of leptospirosis cases by the supervising scientist of the Western Pacific Region World Health Organization/Food and Agricultural Organization Collaborating Centre for Reference and Research on Leptospirosis. Investigation revealed a cluster of eight leptospirosis cases diagnosed during October and November 1998. All were employees of a local meat works. Leptospira serovars isolated included pomona and hardjo. Symptoms included headache, fever, muscle pain, sore eyes, abdominal pain, vomiting, jaundice, and rash. Five of the eight cases were hospitalised. The infection could not be traced to any particular source. Unfortunately, records of stock killed during the exposure periods were not available. All cases reported exposure to large volumes of animal urine during the course of their work. Protective clothing provided included an apron, gloves, and rubber boots. All of the patients said they wore rubber boots and seven of the eight wore the apron provided. Only two patients reported wearing gloves, the remainder thought these were too difficult to work in.

Abattoirs↗
PubMed1999

Detection of rat Pneumocystis carinii proteinases and elastase and antipneumocystis activity of proteinase inhibitors in vitro.

Proteinases play an important role in survival of microorganisms and in pathogenicity of diseases. By using a modified SDS-gelatin-polyacrylamide gel system, proteinases of rat-P.carinii were detected as bands of proteolytic digestion after electrophoresis. P.carinii organisms obtained from dexamethasone immunosuppressed transtracheally infected rats were cultured in spinner flask suspension cultures to minimize host cell contamination. At pH 8.3, seven Pc-specific proteolytic bands were detected in three clusters of different molecular weights clearly different from host cell patterns. By using a range of pH, various preparations of organisms and both infected and uninfected culture media, proteolytic activities have been partially characterized. Elastase secretion has been assessed based on elastin digestion model. Proteinase inhibitors have been tested for their ability to inhibit P.carinii growth in HEL299 short-term monolayer cultures. Results indicate that proteolytic activities are involved in the proliferation of microorganisms since leupeptin exerted in vitro antipneumocystis activity while aprotinin enhanced P.carinii growth.

Animals↗
PubMed1999

Cilioretinal artery occlusion with central retinal vein occlusion.

BACKGROUND: Combined cilioretinal artery and retinal vein occlusions are infrequently documented retinal vascular disorders of speculative origin. Occlusion of the cilioretinal artery is believed to result from either mechanical compression of the artery as a result of an increase in venous pressure or from a reduction in perfusion pressure in both the cilioretinal and retinal arteries. The ophthalmoscopic and angiographic features of this condition are reviewed. CASE REPORTS: Two cases of cilioretinal artery occlusion after central retinal vein occlusion are presented, one of which evolved to the development of iris neovascularization. DISCUSSION: The incidence of cilioretinal artery occlusions due to central retinal vein occlusions is infrequently reported in the literature. Excluding those with chronic cystoid macular edema, most patients have a favorable visual outcome. It is possible that the incidence of combined cilioretinal artery and central retinal vein occlusions is grossly underestimated.

Adult↗
PubMed1999

Lipoprotein(a), essential fatty acid status and lipoprotein lipids in female Australian vegetarians.

In the present study we investigated serum lipoprotein(a) [Lp(a)] levels, plasma lipids, the serum phospholipid polyunsaturated fatty acid profile and correlates of serum Lp(a) in healthy free-living female vegetarians (n=50) and omnivores (n=24) to assess differences which may have implications for cardiovascular risk. Dietary saturated fat and total plasma cholesterol were significantly lower in the vegetarians compared with omnivores. The mean serum Lp(a) concentration was lower in the vegetarians (171 mg/l) than in the omnivores (247 mg/l). The serum Lp(a) concentration was significantly negatively correlated with carbohydrate intake (as % of energy), and positively correlated with plasma total cholesterol. Compared with the omnivores, the vegetarians had significantly lower concentrations of 20:3,n-6, 20:4,n-6, 22:5,n-6, 20:5,n-3, 22:6,n-3 and total n-6 and n-3 polyunsaturated fatty acids, and a lower n-3/n-6 polyunsaturated fatty acid ratio, in serum phospholipids. Lower concentrations of plasma total cholesterol, serum phospholipid total fatty acids, total saturated fatty acids and arachidonic acid, and a tendency towards a lower serum Lp(a) concentration, in vegetarians may have beneficial effects on cardiovascular disease risk. However, the decreased concentration of serum phospholipid n-3 polyunsaturated fatty acids may potentially promote thrombotic risk. Based on the present data, it would seem appropriate for omnivores to reduce their dietary intake of total fat and saturated fat in order to decrease their plasma cholesterol, and vegetarians should perhaps increase their dietary intake of n-3 polyunsaturated fatty acids, and thus improve the balance of n-3/n-6, in order to reduce any thrombotic tendency that might increase their generally low risk of cardiovascular disease.

Adult↗
PubMed1998

The effect of a teledermatology program on rural referral patterns to dermatologists and the management of skin disease.

Teledermatology can be defined as the use of imaging and telecommunications technologies to provide skin care services at a distance. The potential value of teledermatology is especially great in rural and medically underserved areas that do not have, or cannot support, providers specializing in the diagnosis and management of skin diseases. Rural patients and primary care providers should be able to use teledermatology as a greatly simplified and potentially less expensive means of referral to an urban dermatologist. In an effort to gauge the impact of a simple teledermatology system on referral patterns and the management of rural patients with skin disorders, we studied baseline rates of referral to dermatologists from five primary care clinics in rural Oregon. Economical, easy-to-use teledermatology systems were subsequently installed, and the effects on patient referral and management were recorded over time. The interim results suggest that primary care providers (PCPs) are reluctant to refer patients with skin conditions, even when the primary care providers confidence in the correct diagnosis and treatment plan for that condition are relatively low. The installation of a teledermatology system increases the number of patients referred for specialist evaluation dramatically, even while the number of in-person visits to specialists fell. Although diagnostic agreement between dermatologists and primary care providers was mixed, a marked difference was found in their recommended treatment plans. A number of cases were found in which use of the telemedicine technology system resulted in reversing conditions that had been poorly controlled for a number of years prior to teleconsultation. This work is important as an indicator that referral rates to dermatologists may be inappropriately low in rural areas of the U.S., and that use of teledermatology may improve this trend.

Dermatology↗
PubMed1997

Total quality management in accredited New South Wales hospitals: a public/private comparison.

Analysis of data collected in a 1994-95 survey of accredited New South Wales hospitals examined the adoption of key elements of total quality management practice in the public and private sectors. In a number of areas of practice widely considered to be central to a hospital's total quality management efforts, there was no statistically significant difference between the two sectors. Where differences existed, total quality management practices more likely to be adopted by public hospitals were limited in their scope and likely to be explained by structural peculiarities. In contrast, private hospitals were more likely to adopt practices more critical to the successful implementation of total quality management.

Accreditation↗
PubMed1997

Multicenter evaluation of proposed standardized procedure for antifungal susceptibility testing of filamentous fungi.

A multicenter study was conducted to expand the generation and analysis of data that supports the proposal of a reference method for the antifungal susceptibility testing of filamentous fungi. Broth microdilution MICs of amphotericin B and itraconazole were determined in 11 centers against 30 coded duplicate pairs of Aspergillus spp., Fusarium spp., Pseudallescheria boydii, and Rhizopus arrhizus. The effect of inoculum density (approximately 10(3) and 10(4) CFU/ml), incubation time (24, 48, and 72 h), and procedure of MIC determination (conventional and colorimetric [Alamar Blue] evaluation of growth inhibition) on intra- and interlaboratory agreement was analyzed. Based on intra- (97 to 100%) and interlaboratory (94 to 95%) agreement for both drugs, the overall optimal testing conditions identified were determination of colorimetric MICs after 48 to 72 h of incubation with an inoculum density of approximately 10(4) CFU/ml. These testing conditions are proposed as guidelines for a reference broth microdilution method.

Antifungal Agents↗
PubMed1996

Total quality management practices in the NSW hospital system--an overview.

A two-phase descriptive study involving a questionnaire survey was undertaken during 1994 and 1995 to evaluate the extent of implementation of total quality management practices in New South Wales hospitals accredited by the Australian Council on Healthcare Standards. A survey response rate of 72 per cent was attained. Results indicated that most hospitals were aware of and consciously implemented aspects of the total quality management philosophy in some way. There is little evidence that whole systems have embraced the total quality management approach as a fully integrated endeavour.

Community-Institutional Relations↗
PubMed1995

Contraceptive implant use among inner city teens.

PURPOSES: This study develops a clinical profile of urban teens who selected Norplant for contraception; determines which variables identify the subjects most likely to be compliant with the method; and determines the most common reasons for early termination of use. METHODS: Demographic and health history data and reasons for termination of use were collected prospectively for 122 inner city teens who received Norplant. Life table analysis and the Mantel-Haenszel procedure were used to investigate differences between Norplant retainers and terminators. RESULTS: The sample consisted of black and Hispanic teens between the ages of 13-19 years, the majority of whom had one or more children and were in school. One and two year retention rates were 71% and 62%. The highest removal rates occurred during the 3-6 month interval after insertion. A significant finding was that teens who have experienced induced abortion were more likely to retain Norplant. Common reasons for termination of use included general and social concerns, including pregnancy desire. CONCLUSIONS: Norplant retention rates for this teen sample were greater than the compliance rates reported for other conventional methods. Similar to noncompliance with oral contraceptives, discontinuance of the method was most likely to occur in the first 6 months of use. A history of induced abortion identifies those teens most likely to retain Norplant, suggesting that these teens might evaluate contraceptive risks and benefits differently than those with no abortion history. Pregnancy desire was a common reason for terminating Norplant use.

Adolescent↗