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Biomedical subjects

E Harrington

Publications and source records attributed to E Harrington.

At least 55 records · Page 3Linked to original sources
PubMed1992

Leukocyte scanning with 111In is superior to magnetic resonance imaging in diagnosis of clinically unsuspected osteomyelitis in diabetic foot ulcers.

OBJECTIVE: To compare the accuracies of MRI and leukocyte scanning in diagnosing clinically unsuspected osteomyelitis in diabetic foot ulcers. RESEARCH DESIGN AND METHODS: A prospective study of 16 diabetic foot ulcers in 12 patients, including both ambulatory and hospitalized patients, was performed at a university medical center. Pedal images were obtained by leukocyte scanning with [111In]oxyquinoline and MRI. Definitive diagnosis of osteomyelitis then was determined by bone biopsy for culture and histology. RESULTS: Biopsy-proven osteomyelitis was present in 7 (44%) of the 16 foot ulcers. The diagnosis was suspected clinically in 0%. Leukocyte scanning was 100% sensitive, whereas MRI was only 29% sensitive in diagnosing osteomyelitis in diabetic foot ulcers. Specificities were 67 and 78%, respectively. The positive and negative predictive values (70 and 100%, respectively) for the leukocyte scan also were greater than those of MRI (50 and 58%, respectively). CONCLUSIONS: Leukocyte scanning is superior to MRI in detecting clinically unsuspected osteomyelitis in diabetic foot ulcers.

Biopsy↗
PubMed1991

Unsuspected osteomyelitis in diabetic foot ulcers. Diagnosis and monitoring by leukocyte scanning with indium in 111 oxyquinoline.

OBJECTIVE: The prevalence of osteomyelitis in diabetic foot ulcers is unknown. Early diagnosis of this infection is critical, as prompt antibiotic treatment decreases the rate of amputation. We therefore assessed the prevalence of osteomyelitis in 35 diabetic patients with 41 foot ulcers. We compared results of roentgenograms, leukocyte scans with indium In 111 oxyquinoline, and bone scans with the diagnostic criterion standards of bone histologic and culture findings. Leukocyte scans were repeated at 2- to 3-week intervals during antibiotic treatment. DESIGN: Cohort study. SETTING: Institutional and private, ambulatory and hospitalized patients. PATIENTS: Consecutive sample of 54 diabetic patients. Thirty-five patients with 41 foot ulcers were included. RESULTS: As determined by bone biopsy and culture, osteomyelitis was found to underlie 28 (68%) of 41 diabetic foot ulcers. Only nine (32%) of the 28 cases were diagnosed clinically by the referring physician. Underscoring the clinically silent nature of osteomyelitis in these ulcers, 19 (68%) of 28 occurred in outpatients, 19 (68%) of 28 occurred in ulcers not exposing bone, and 18 (64%) of 28 had no evidence of inflammation on physical examination. All patients with ulcers that exposed bone had osteomyelitis. Of the imaging tests, the leukocyte scan had the highest sensitivity, 89%. In patients with osteomyelitis, the leukocyte scan image intensity decreased by 16 to 34 days of antibiotic treatment and normalized by 36 to 54 days. CONCLUSION: The majority of diabetic foot ulcers have an underlying osteomyelitis that is clinically unsuspected. Leukocyte scans are highly sensitive for diagnosing osteomyelitis in diabetic foot ulcers and may be useful for monitoring the efficacy of antibiotic treatment. We recommend that diabetic patients with foot ulcers that expose bone should be treated for osteomyelitis. Diabetic patients with foot ulcers that do not expose bone should undergo leukocyte scanning, which eliminates the risk of bone biopsy in diagnosing osteomyelitis and allows for the diagnosis and treatment of this well-known but often silent precursor of lower extremity amputation.

Diabetes Mellitus, Type 2↗
PubMed1990

Clasp retention and composites: an abrasion study.

An in vitro test for screening the abrasion resistance and abrasivity of composite resins when used to provide tooth undercuts for removable partial denture clasps is described. In the present study nine composite resins were tested against wrought stainless steel round clasps. The results indicated that the abrasion of any of the composites tested was unlikely to cause a noticeable loss of retention in the clinical situation. However, there was marked abrasion of the clasps by two of the composites which would be likely to be clinically relevant.

Analysis of Variance↗
PubMed1989

Pressures produced in vitro during intraligamentary anaesthesia.

An in vitro investigation measured the pressures produced by an Astra type aspirating syringe (modified Sterling) and a pressure syringe (Ligmaject) during periodontal ligament injections. A pressure transducer (0-6.9 MPa) was adapted to record the pressures generated within both syringes, with the output of the transducer connected to a microcomputer. Thirty-five clinicians (male: female ratio 3:2) were instructed in the technique of the periodontal ligament injection and the pressures that they produced from both syringes were recorded. Measurements of both the peak and time averaged pressures were obtained from computer print-outs of the recordings. Significantly higher pressures (P less than 0.01) were produced with the pressure syringe than with the aspirating syringe. It was also found that male operators produced significantly (P less than 0.1) higher pressure with the aspirating syringe, although there was no significant sex difference (P greater than 0.1) between the pressures recorded with the pressure syringe. Recordings from the pressure syringe revealed that either a multiple high pressure technique or a steady pressure technique was used, the former producing significantly (P less than 0.01) higher pressures.

Anesthesia, Dental↗
PubMed1989

Ultrasonic debonding of composite-retained restorations.

Ultrasonic chisels are used clinically to remove composite-retained bridges from one or both abutment teeth. Displacement amplitude measurements at the tip of the two designs available showed that the curved chisel was twice as powerful as the straight chisel. Investigations were undertaken to assess the efficiency of these chisels in vitro. Cast metal retainers were made, which incorporated particulate roughening of the fitting surface and these were bonded with a composite luting cement to extracted premolar teeth. Ten clinicians were asked to remove the retainers from the teeth and their application forces were measured. Clinicians were able to apply the highest force with the straight chisel design. The time taken to remove the retained restorations under increasing application forces and different power settings of the two chisels was then measured. Optimal time for removal of the retainers (ie with 5-10 minutes' exposure) required the use of high displacement amplitudes of the chisel, together with high application forces. Scanning electron microscopy of the failed bond revealed that composite was removed in those areas where the chisel was applied to the tooth. However, there was a disproportionate amount of tooth surface damage compared to that inflicted upon the metal retainer.

Composite Resins↗
PubMed1989

The determination of elastic recovery of impression materials at the setting time.

One of the prime requisites of an elastomeric impression material is that it should possess adequate elastic recovery on removal from undercut areas. Most standard methods of measuring elastic recovery rely on the preparation of specimens in moulds. The specimens are subsequently removed and subjected to compressive or tensile stresses several minutes after the setting time. The equipment described in this paper has been developed to enable elastic recovery values to be determined at times in the vicinity of the setting time. A shear strain is induced in the material for a short time and the resulting recovery recorded graphically. Results indicate that there is a significant improvement in elastic recovery from just prior to until just after the setting time.

Chemical Phenomena↗
PubMed1989

Rigidity of elastomeric impression materials.

The rigidity of an impression material should be less than a certain value in order that excessive forces are not required when taking impressions of undercut areas. Conversely, the impression should be sufficiently rigid to withstand the weight of stone whilst pouring the cast without distortion. This paper describes a method of determining elastic modulus values at times as early as the setting time of the material. Results indicate that the elastic modulus values increase from the setting time to 30 min after the start of mix. Values are presented for a representative range of elastomeric impression materials.

Chemical Phenomena↗
PubMed1989

Consistency, working time and setting time of elastomeric impression materials.

This paper describes the development of an instrument for determining consistency, working time and setting time of elastomeric impression materials. The operating principle involves the application of a fixed compressive strain and the resulting stress is measured. This instrument has been called a Comprheometer. Temperature control is achieved by water circulation so that simulated room or open-mouth temperatures can be used. Values of consistency and working time are presented for a range of elastomeric materials at room temperature. Also, setting times determined under oral conditions are recorded.

Chemical Phenomena↗
PubMed1988

Treatment of ischemia due to "steal" by arteriovenous fistula with distal artery ligation and revascularization.

Three cases are described of upper extremity ischemia occurring after the creation of fistulas (AVFs) (one case) and bridge AVFs (two cases) for hemodialysis access. All three cases were successfully treated with ligation of the artery immediately distal to the origin of the AVF in conjunction with a reversed saphenous vein bypass. The latter was constructed from the artery proximal to the origin of the fistula to the artery distal to the site of ligation. Preoperative and postoperative hemodynamic measurements and complete disappearance of symptoms indicated that this procedure corrected the ischemic steal phenomenon. Angioaccess function was not affected in these three cases, thereby allowing continuation of its use immediately after corrective surgery and for follow-up periods of 1 month, 6 months, and 8 years.

Adult↗
PubMed1980

Cryptogenic hepatic abscess in two uncompromised children.

A pre-mortem diagnosis of cryptogenic liver abscess in children is rare, but this diagnosis must be considered in the evaluation for pyrexia of unknown origin. Two previously healthy children were suspected of harboring liver abscesses. Radioisotopic, sonographic, and angiographic evidence supported the clinical diagnosis. Operative drainage was performed in each case. No source for either abscess was found and no cause established. Anaerobic bacteria, microaerophilic streptococcus and Fusobacterium necrophorum, each in pure culture, were retrieved on culture of the pus from each child's abscess. Experience gleaned from these two cases emphasizes the possibility of an hepatic abscess existing in the uncompromised child with fever of unknown origin. A cryptogenic hepatic abscess may occur in a child with only mild gastrointestinal complaints and in a child with sickle cell disease. Recovery is attributed to suspicion of diagnosis, prompt investigation, operative drainage, effective culture technique with isolation of organism and appropriate antibiotic coverage.

Adolescent↗
PubMed1978

The cavity sealing ability of composite restorations subjected to thermal stress.

An artificial caries technique, using a diffusion controlled acidified gel, was used to create in vitro artificial lesions adjacent to composite restorations. Prior to gel immersion, test specimens were temperature-cycled in a machine designed specifically for this purpose. Examination of control specimens showed little evidence of leakage, the presence of a cavity wall lesion being used as an indication of leakage. Compared to the controls, the test specimens showed either a reduction or no change in leakage pattern. It is suggested that thermal percolation may not be of clinical significance in relation to composite restorations.

Absorption↗
PubMed1977

An apparatus for the simultaneous demineralization of fifty-four specimens.

An apparatus designed to demineralize 54 specimens simultaneously is described. A drum with built-in specimen holders rotates continuously through a bath of acid, allowing a free exchange of demineralizing fluid over the specimens. Individual specimens can be easily introduced or withdrawn from the apparatus without disturbing others.

Evaluation Studies as Topic↗