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Biomedical subjects

W F Todd

Publications and source records attributed to W F Todd.

At least 19 recordsLinked to original sources
PubMed1997

The natural history of acute Charcot's arthropathy in a diabetic foot specialty clinic.

The aim of this longitudinal study was to report on the clinical characteristics and treatment course of acute Charcot's arthropathy at a tertiary care diabetic foot clinic. Fifty-five diabetic subjects, with a mean age of 58.6 +/- 8.5 years, were studied. All patients were treated with serial total contact casting until quiescence. Following casting and before transfer to prescription footwear, patients were eased into unprotected weightbearing via a removable cast walker. This cohort was followed for their entire treatment course and for a mean 92.6 +/- 33.7 weeks following return to shoes. Pain was the most frequent presenting complaint in these otherwise insensate patients (76%). The mean duration of casting was 18.5 +/- 10.6 weeks. Patients returned to footwear in a mean 28.3 +/- 14.5 weeks. Nine per cent of the population had bilateral arthropathy. These subjects were casted significantly longer than the unilateral group (p < 0.02). Surgery was performed on 25 % of patients, with approximately two-thirds of these procedures involving plantar exostectomies and one-third fusions of affected joints. Patients receiving surgery remained casted significantly longer than non-surgical patients (p < 0.05). Additionally, men were casted longer than women (p < 0.008). Acute Charcot's arthropathy requires prompt, uncompromising reduction in weightbearing stress. Our data show that the ambulatory total contact cast is very effective for this. Regardless of the specific treatment method instituted, it is imperative that appropriate and aggressive treatment be undertaken immediately following diagnosis to help prevent progression to a profoundly debilitating, limb-threatening deformity.

Acute Disease↗
PubMed1997

Infrared dermal thermometry for the high-risk diabetic foot.

BACKGROUND AND PURPOSE: The purpose of this study was to compare skin temperatures in patients with asymptomatic peripheral sensory neuropathy, patients with neuropathic ulcers, and patients with Charcot's arthropathy using the contralateral limb as a control. SUBJECTS: On a retrospective basis, patients with diabetes (N = 143) were divided into three groups: patients with asymptomatic sensory neuropathy (n = 78), patients with neuropathic foot ulcers (n = 44), and patients with neuropathic fractures (Charcot's arthropathy) (n = 21). METHODS: We evaluated the subjects' skin temperatures with a portable hand-held infrared skin temperature probe at the time pathology was initially identified and at subsequent clinical visits for an average of 22.1 months (SD = 6.4). Skin temperatures of the contralateral foot were measured as a control. RESULTS: There were differences in skin temperature between the affected foot and the contralateral (i.e., nonaffected) foot among the patients with Characot's arthropathy (8.3 degrees F) and the patients with neuropathic ulcers (5.6 degrees F), with no difference identified among the patients with asymptomatic sensory neuropathy. Five patients with neuropathic ulcers experienced reulceration a mean of 12.2 months (SD = 6.4) after initial healing, with a corresponding increase in skin temperature. (89.6 degrees +/- 1.2 degrees F versus 82.5 degrees +/- 2.9 degrees F) at the clinic visit immediately preceding reinjury. CONCLUSION AND DISCUSSION: The data suggest that monitoring of the corresponding contralateral foot site may provide clinical information before other clinical signs of injury can be identified.

Aged↗
PubMed1997

The natural history of acute Charcot's arthropathy in a diabetic foot specialty clinic.

The aim of this longitudinal study was to report on the clinical characteristics and treatment course of acute Charcot's arthropathy at a tertiary care diabetic foot clinic. Fifty-five diabetic subjects, with a mean age of 58.6 +/- 8.5 years, were studied. All patients were treated with serial total contact casting until quiescence. Following casting and before transfer to prescription footwear, patients were eased into unprotected weightbearing via a removable cast walker. This cohort was followed for their entire treatment course and for a mean 92.6 +/- 33.7 weeks following return to shoes. Pain was the most frequent presenting complaint in these otherwise insensate patients (76%). The mean duration of casting was 18.5 +/- 10.6 weeks. Patients returned to footwear in a mean 28.3 +/- 14.5 weeks. Nine per cent of the population had bilateral arthropathy. These subjects were casted significantly longer than the unilateral group (p < 0.02). Surgery was performed on 25% of patients, with approximately two-thirds of these procedures involving plantar exostectomies and one-third fusions of affected joints. Patients receiving surgery remained casted significantly longer than non-surgical patients (p < 0.05). Additionally, men were casted longer than women (p < 0.008). Acute Charcot's arthropathy requires prompt, uncompromising reduction in weightbearing stress. Our data show that the ambulatory total contact cast is very effective for this. Regardless of the specific treatment method instituted, it is imperative that appropriate and aggressive treatment be undertaken immediately following diagnosis to help prevent progression to a profoundly debilitating, limb-threatening deformity.

Acute Disease↗
PubMed1996

Evaluation and treatment of the infected foot in a community teaching hospital.

More inpatient hospital days are used for the care of diabetic foot infection than for any other diabetic sequela. Both the number of lower extremity amputations and the overall treatment cost of treating diabetic infections may be reduced by using a team approach in the care of the infected diabetic pedal wound. The authors propose an evaluation and treatment protocol of infected pedal ulcerations in an urban, community teaching institution when admitted to an established, multidisciplinary diabetic foot care team. The hospital course of 111 patients admitted with a primary diagnosis of infected pedal ulceration are retrospectively reviewed. Results revealed an average-length hospital stay of 7.4 days with a 96% limb-salvage rate. The authors suggest that in the treatment of the infected pedal wound, a diabetic foot care team with a well developed treatment protocol may yield a consistently favorable outcome and a cost-effective hospital course.

Diabetic Foot↗
PubMed1995

1995 William J. Stickel Bronze Award. Prevalence of mixed infections in the diabetic pedal wound. A retrospective review of 112 infections.

This retrospective study reviewed the culture results of 112 admissions to a multidisciplinary diabetic foot care team with a primary diagnosis of infected diabetic pedal ulceration. An average of 1.5 +/- 0.9 species per patient (P < 0.0001) were isolated. Eighty-nine percent of wounds cultured grew two or fewer organisms. Anaerobic species were isolated in only 5% of all cultures. Of these isolates, the distinction between anaerobic colonization and true anaerobic infection is made. Results suggest that aggressive early hospitalization, coupled with aggressive intraoperative debridement, may yield less microbiologically complex infections that may be controlled with less expensive narrow spectrum antibiotic therapy. Diagnosis of the infected pedal ulceration of a patient with diabetes is a clinical one. If this diagnosis is combined with appropriate surgical intervention, microbiologic correlation, and antimicrobial therapy, the result may be a less complex hospital course and improved outcome.

Adult↗
PubMed1995

Contralateral limb during total contact casting. A dynamic pressure and thermometric analysis.

The authors draw attention to the importance of evaluation of the contralateral limb when treating unilateral sequelae secondary to distal symmetrical polyneuropathy. Plantar pressure measurements of the contralateral limb during total contact casting are reviewed. The results of thermometric evaluation before and after initiation of repetitive stress were reviewed. The results suggest that the patient walking in a total contact cast may experience a reduced focal pressure on the contralateral limb when compared with uncasted walking and three-point walking with crutches. Dermal thermometry may be a highly sensitive tool in evaluating even mild increases in repetitive stress. To explain this decrease in contralateral stress, the authors examine the features inherent to the total contact cast and propose the concept of proprioceptive stability.

Casts, Surgical↗
PubMed1995

Potential risks of accommodative padding in the treatment of neuropathic ulcerations.

In order to appropriately treat the pedal diabetic wound, the treatment plan must have as its central focus the elimination or reduction of foci of stress. The purpose of this study is to analyze the off-weighting ability of aperture pads in an effort to help the practitioner choose an appropriate and effective stress relieving modality. Patients were fitted and measured while ambulating using 3 different accommodative modalities. Utilizing an electronic measurement system for the recording of pressure distribution, the plantar pressure of each subject was recorded. Measurements taken during accommodative padding were compared with the same foot or corresponding site during unpadded ambulation. The data indicates that when apertures are created in an attempt to off-weight a given ulceration or area of stress, an area of increased vertical pressure is created at the periphery of the ulceration; and that while the central aspect of the aperture pad seems to off-weight the area, the periphery bears an undue amount of vertical stress, thus amplifying shear forces and tearing of tissue as the metatarsal moves proximally during gait. We therefore conclude that none of the devices reviewed are ideal for off-weighting the plantar neurotrophic wound.

Adult↗
PubMed1994

Presentations of diabetic feet.

Those afflicted with diabetes mellitus have high rates of morbidity and mortality owing to the many complications of the disease. The complications can manifest themselves as ophthalmic, renal, vascular, neurologic, and pedal diseases. Unfortunately, the most often overlooked or neglected complications involve the feet. It is estimated that in the United States foot disease is five times more prevalent in diabetic patients than in those without diabetes. In fact, 20% of all diabetic patients admitted to hospitals in the United States are admitted for foot disease, with foot and ankle ulcers being the most common presentation.

Diabetes Complications↗
PubMed1993

Evaluation and control of worker exposure to fungi in a beet sugar refinery.

A study of worker exposure to airborne fungi was undertaken in a sugar beet refinery to evaluate the level of exposure and to determine if controls could be implemented that would lower these exposures. A previous study at this refinery identified one worker who reacted on challenge testing to the moldy but not the fresh sugar beet pulp, had specific Immunoglobulin G to Aspergillus niger, and specific Immunoglobulin E to Aspergillus. Also, two employees were diagnosed with occupational asthma. In the study reported here, two field surveys were conducted, the first during the sugar production campaign (January) and the second during postproduction cleanup and maintenance (June). Approximately 65 personal and area air samples were collected on polycarbonate filters and the culturable fungal spores were identified and enumerated. This study showed high exposure of pellet loaders and pellet silo workers to various species of Aspergillus. Other fungal species that might pose a health hazard were detected. Exposures to fungi during the postproduction cleanup and maintenance phase were much higher than those measured during the production campaign. Engineering controls that would reduce employee exposure are discussed.

Air Microbiology↗
PubMed1992

Evaluation of eight bioaerosol samplers challenged with aerosols of free bacteria.

The need to quantify airborne microorganisms in the commercial microbiology industry (biotechnology) and during evaluations of indoor air quality, infectious disease outbreaks, and agriculture health investigations has shown there is a major technological void in bioaerosol sampling techniques to measure and identify viable and nonviable aerosols. As commercialization of microbiology increases and diversifies, it is increasingly necessary to assess occupational exposure to bioaerosols. Meaningful exposure estimates, by using area or environmental samplers, can only be ensured by the generation of data that are both precise and accurate. The Andersen six-stage viable (microbial) particle sizing sampler (6-STG) and the Ace Glass all-glass impinger-30 (AGI-30) have been suggested as the samplers of choice for the collection of viable microorganisms by the International Aerobiology Symposium and the American Conference of Governmental Industrial Hygienists. Some researchers consider these samplers inconvenient for evaluating industrial bioprocesses and indoor or outdoor environments. Alternative samplers for the collection of bioaerosols are available; however, limited information has been reported on their collection efficiencies. A study of the relative sampling efficiencies of eight bioaerosol samplers has been completed. Eight samplers were individually challenged with a bioaerosol, created with a Collison nebulizer, of either Bacillus subtilis or Escherichia coli. The samplers were evaluated under controlled conditions in a horizontal bioaerosol chamber. During each experimental run, simultaneous samples were collected with a reference AGI-30 to verify the concentration of microorganisms in the chamber from run to run and day to day.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1990

The application of dustiness tests to the prediction of worker dust exposure.

Laboratory bench tests, known as dustiness tests, have been used to evaluate and compare the potential of various powders to cause occupational dust exposure. Dustiness tests are used to develop products with reduced dust emissions. The correlation between dustiness test results and dust exposures was evaluated at two bag dumping and bag filling operations. At one bag dumping and one bag filling operation, there was evidence of a relationship between dustiness test results and dust exposures. In one case, regression analysis showed that dust exposures could be predicted to within nearly one order of magnitude. The variability in this prediction was caused by the inherent variability in the occupational dust exposures. In the other case, there was evidence of a correlation after the data had been adjusted for the effect of varying drop height. At the remaining two operations, no correlation between dust exposures and dustiness test results were observed. These results indicate that the relevance of dustiness tests to occupational dust exposure needs to be evaluated at each site. Because a better option does not exist, manufacturers should continue to use empirical dustiness tests to develop better products in the laboratory. The conclusions reached in the laboratory need to be validated by dust exposure measurements in the field, however.

Air Pollutants, Occupational↗
PubMed1989

Abnormal biomechanics of flatfoot deformities and related theories of biomechanical development.

The flatfoot deformity has been investigated over this century by many leading authorities with regard to its etiologies and pathogenesis. A large number of articles in the early orthopedic literature concerning the flatfoot deformity defined the primary abnormalities of the structure without strong emphasis on its relationship to abnormal functional etiologies leading to the pathogenesis of the deformity. This article emphasizes abnormal biomechanics and theories of development.

Biomechanical Phenomena↗
PubMed1985

Styrene vapor control systems in FRP yacht plants.

The production of large (greater than 25-ft) fiber-reinforced plastic (FRP) yachts has presented problems of styrene exposure in excess of the Occupational Safety and Health Administration permissible exposure level (OSHA PEL) of 100 ppm. Also, the National Institute for Occupational Safety and Health (NIOSH) is currently recommending a 10-hour workshift, 40-hour workweek time weighted average (TWA) of 50 ppm for styrene. Meeting this challenge will require a system of engineering, work practice, personal protective equipment, and monitoring control measures. NIOSH has performed a study of the engineering controls in three FRP yacht plants. Work practices and the use of personal protective equipment (PPE) were also considered in the evaluation. The three systems evaluated included a dilution system, a local ventilation system, and a push-pull ventilation system. The cost of constructing and operating these systems was not evaluated in this study. Study results indicated that each type of ventilation system can meet the present PEL of 100 ppm styrene; however, it is not certain that these systems can meet a lower PEL of 50 ppm styrene.

Air Pollutants, Occupational↗
PubMed1984

Control of styrene vapor in a large fiberglass boat manufacturing operation.

An evaluation of a control system for worker protection from styrene vapor was performed at a manufacturer of large fiberglass reinforced plastic yachts. The manufacturing operations included five tiltable boat hull mold stations. Each station had a floor air slot located beneath the mold which was exhausting about 17 000 CFM. The building had an overall ventilation rate of 10-15 air changes per hour. An attempt was made to improve the performance of this control system by blowing air into the hull mold and by blocking air flow from the back of the mold to induce greater flow from the front of the mold. Consecutive short term breathing zone samples were collected in an effort to show the effect of different job tasks and work modes on exposures. ANOVA was performed to determine levels of significance of several variables. A significant exposure difference was found between right and left tilts of the 46-foot hull mold. The TWA styrene exposure values for the 3-day period of the 4 hull lamination workers were low, ranging from 17 ppm to 25 ppm, and demonstrating that styrene levels can be effectively controlled by means of strategically located high volume exhaust vents for the process studied.

Acetone↗