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Biomedical subjects

J Craighead

Publications and source records attributed to J Craighead.

7 recordsLinked to original sources

Infrared-mediated thermocycling for ultrafast polymerase chain reaction amplification of DNA.

Interest in improving the speed of DNA analysis via capillary electrophoresis has led to efforts to integrate DNA amplification into microfabricated devices. This has been difficult to achieve since the thermocycling required for effective polymerase chain reaction (PCR) is dependent on an effective contact between the heating source and the PCR mixture vessel. We describe a noncontact method for rapid and effective thermocycling of PCR mixtures in electrophoretic chip-like glass chambers. The thermocycling is mediated through the use of a tungsten lamp as an inexpensive infrared radiation source, with cooling effected with a solenoid-gated compressed air source. With temperature ramping between 94 and 55 degrees C executed in glass microchambers as rapidly as 10 degrees C/s (heating) and 20 degrees C/s (cooling), cycle times as fast as 17 s could be achieved. Successful genomic DNA amplification was carried out with primers specific for the beta-chain of the T-cell receptor, and detectable product could be generated in a fraction of the time required with commercial PCR instrumentation. The noncontact-mediated thermocycling format was not found to be restricted to single DNA fragment amplification. Application of the thermocycling approach to both quantitative competitive PCR (simultaneous amplification of target and competitor DNA) and cycle sequencing reactions (simultaneous amplification of dideoxy terminated fragments) was successful. This sets the stage for implementing DNA thermocycling into a variety of microfabricated formats for rapid PCR fragment identification and DNA sequencing.

DNA↗

Free-standing health care facilities: financial arrangements, quality assurance and a pilot study.

Free-standing health care facilities now deliver many diagnostic and therapeutic services formerly provided only in hospitals. The financial arrangements available to these facilities differ according to whether the services are uninsured or insured. For an uninsured service, such as cosmetic surgery, the patient pays a fee directly to the service provider. For an insured service, such as cataract surgery, the provincial government uses tax revenues to fund the facility by paying it a facility fee and remunerates the physician who provided the service with a professional fee. No comprehensive, proactive quality assurance efforts have been implemented for either these facilities or the clinical practice provided within them. A pilot study involving therapeutic facilities in Ontario has suggested that a large-scale quality improvement effort could be undertaken in these facilities and rigorously evaluated.

Ambulatory Care Facilities↗

Pathogenetic role of HIV infection in Kaposi's sarcoma of equatorial East Africa.

Thirty residents of north-central Tanzania with various forms of Kaposi's sarcoma (KS) were evaluated. The absolute number of peripheral blood OKT4 lymphocytes in patients and Tanzanian control subjects tended to be low (in comparison with healthy young American adults), and many had inverted T4/T8 ratios. Plasma polyclonal beta- and gamma-globulin concentrations were increased in many patients with KS and in control patients in Tanzania with chronic dermatopathies, but not in African hospital employees and patients undergoing elective surgery. Three of nine patients with locally aggressive KS possessed antibodies to human T-cell lymphotropic virus type III/lyphadenopathy-associated virus (HIV), but none had evidence of the acquired immunodeficiency syndrome (AIDS) or the AIDS-related complex. Three patients with disseminated, rapidly progressive KS and high HIV-antibody titers had an immunologic and clinical picture consistent with AIDS. Two of 13 patients with the classic plaque/nodular form of KS had low plasma titers of HIV antibody, but the significance of these serologic findings is not known. The evidence suggests that HIV plays a role in the pathogenesis of some cases of KS in East Africa, but most patients with KS in East Africa have no evidence of overt immunologic deficiency or HIV infection.

AIDS-Related Complex↗

Patient satisfaction as an indicator of quality care in independent health facilities: developing and assessing a tool to enhance public accountability.

The objective of this research was to examine the performance of a brief patient survey about quality of care received in community-based diagnostic and therapeutic facilities. The survey was administered to patients in 44 facilities that were also scheduled for a formal external assessment. The response rate was 53%. Patients generally rated their care positively; 18.5% of patients rated at least 1 item as fair or poor. The amount of information received about risks and complications was rated least favorably; concern and caring shown by staff was rated most favorably. The 10 items which patients rated regarding aspects of quality formed an internally consistent scale (alpha = .93). Patients' ratings were not useful predictors of assessor ratings. Although patients' ratings cannot substitute for expert on-site assessments, they are an important part of a quality management program. The patient survey provides additional, complementary information about components of quality care that are important to them.

Analysis of Variance↗

Health services utilization after induced abortions in Ontario: a comparison between community clinics and hospitals.

The purpose of this study was to compare postabortion health services utilization of hospital abortion patients with community clinic abortion patients using administrative databases. The study was a retrospective cohort study. The study group consisted of patients with induced abortions (n = 41,039) performed in hospitals or community clinics recorded in the 1995 Ontario Health Insurance Plan claims (OHIP) database. An age-matched cohort of 39,220 women who did not undergo induced abortions was selected from the same data source to serve as controls. The main outcome measures were health services utilization indicators constructed from OHIP data within 3 months postabortion from office consultations, emergency room consultations, and hospital admissions. Hospitalization indicators were constructed from Canadian Institute for Health Information hospital discharge data within 3 months postabortion and included data on hospitalizations for infection, certain surgical events, or psychiatric problems. Postabortion health services utilization and hospitalization were higher in the patient population, regardless of service location, than in the age-matched cohort. Within the abortion patient population, hospital day-surgery patients had higher rates of postabortion utilization and hospitalization than did community clinic patients. Multivariate analysis revealed that hospital day surgery patients had a higher risk of subsequent post-abortion hospitalizations for infections (odds ratio [OR] 1.67, 95% confidence interval [CI] 1.23-2.28), surgical events (OR 1.70, 95% CI 1.30-3.24) and psychiatric problems (OR 2.65, 95% CI 1.77-3.98) than community clinic patients. The rates of postabortion health services utilization and risk of hospitalization were lower in community clinic abortion patients than in hospital day-surgery patients. However, it is not possible to fully control for important confounding variables when using these administrative data.

Abortion, Induced↗