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Biomedical subjects

D G Armstrong

Publications and source records attributed to D G Armstrong.

At least 37 records · Page 2Linked to original sources
PubMed2001

The effects of ulcer size and site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers.

AIMS: The outcome of foot ulcers is affected by wound depth, infection, ischaemia and glycaemic control. The aim of this study was to determine the effects of ulcer size, site, patient's age, sex and type and duration of diabetes on the outcome of diabetic foot ulcers. METHODS: Diabetic patients with new foot ulcers presenting during a 12-month period had demographics and ulcer characteristics recorded at presentation. Ulcers were followed-up until an outcome was noted. RESULTS: One hundred and ninety-four patients (77% males) with a mean (+/- SD) age and duration of diabetes of 56.6 +/- 12.6 and 15.4 +/- 9.9 years, respectively, were included in the study. The majority of ulcers were neuropathic (67.0%) and present on the forefoot (77.8%) with a median (interquartile range) area of 1.5 (0.6-4.0) cm2. Amputations were performed for 15% of ulcers; 65% healed; 16% remained unhealed and 4% of patients died. The median (95% confidence interval) time to healing was 10 (8.8-11.6) weeks. Ulcer area at presentation was greater in the amputation group compared to healed ulcers (3.9 vs. 1.2 cm2, P < 0.0001). Ulcer area correlated with healing time (rs = 0.27, P < 0.0001) and predicted healing (P = 0.04). Patient's age, sex, duration/type of diabetes, and ulcer site had no effect on outcome. CONCLUSIONS: Ulcer area, a measure of ulcer size, predicts the outcome of foot ulcers. Its inclusion into a diabetic wound classification system will make that system a better predictor of outcome.

Age Factors↗
PubMed2001

Electric stimulation as an adjunct to heal diabetic foot ulcers: a randomized clinical trial.

OBJECTIVE: To evaluate high-voltage, pulse-galvanic electric stimulation as an adjunct to healing diabetic foot ulcers. DESIGN: Randomized, double-blind, placebo-controlled pilot trial. SETTING: University medical center. PATIENTS: Forty patients with diabetic foot ulcers, consecutively sampled. Twenty patients each assigned to treatment and placebo groups. Five patients (2 treated, 3 placebo) withdrew because of severe infection. INTERVENTIONS: Electric stimulation through a microcomputer every night for 8 hours. The placebo group used identical functioning units that delivered no current. Additional wound care consisted of weekly débridements, topical hydrogel, and off-loading with removable cast walkers. Patients were followed for 12 weeks or until healing, whichever occurred first. MAIN OUTCOME MEASURES: Proportion of wounds that healed during the study period. Compliance with use of device (in hr/wk), rate of wound healing, and time until healing. RESULTS: Sixty-five percent of the patients healed in the group treated with stimulation, whereas 35% healed with placebo (p = .058). After stratification by compliance, a significant difference was identified among compliant patients in the treatment group (71% healed), noncompliant patients in the treatment group (50% healed), compliant patients in the placebo group (39% healed), and noncompliant patients in the placebo group (29% healed, linear-by-linear association = 4.32, p = .038). There was no significant difference in compliance between the 2 groups. CONCLUSION: Electric simulation enhances wound healing when used in conjunction with appropriate off-loading and local wound care.

Diabetic Foot↗
PubMed2001

Effect of dietary energy and protein on bovine follicular dynamics and embryo production in vitro: associations with the ovarian insulin-like growth factor system.

Heifers were assigned either low or high (HE) levels of energy intake and low or high concentrations of dietary crude protein. The effect of these diets on the plasma concentrations of insulin, insulin-like growth factor (IGF)-I, and urea on follicular growth and early embryo development is described. We propose that the observed dietary-induced changes in the ovarian IGF system increase bioavailability of intrafollicular IGF, thus increasing the sensitivity of follicles to FSH. These changes, in combination with increased peripheral concentrations of insulin and IGF-I in heifers offered the HE diet, contribute to the observed increase in growth rate of the dominant follicle. In contrast to follicular growth, increased nutrient supply decreased oocyte quality, due in part to increased plasma urea concentrations. Clearly a number of mechanisms are involved in mediating the effects of dietary energy and protein on ovarian function, and the formulation of diets designed to optimize cattle fertility must consider the divergent effects of nutrient supply on follicular growth and oocyte quality.

Animals↗
PubMed2001

Wound microbiology and associated approaches to wound management.

The majority of dermal wounds are colonized with aerobic and anaerobic microorganisms that originate predominantly from mucosal surfaces such as those of the oral cavity and gut. The role and significance of microorganisms in wound healing has been debated for many years. While some experts consider the microbial density to be critical in predicting wound healing and infection, others consider the types of microorganisms to be of greater importance. However, these and other factors such as microbial synergy, the host immune response, and the quality of tissue must be considered collectively in assessing the probability of infection. Debate also exists regarding the value of wound sampling, the types of wounds that should be sampled, and the sampling technique required to generate the most meaningful data. In the laboratory, consideration must be given to the relevance of culturing polymicrobial specimens, the value in identifying one or more microorganisms, and the microorganisms that should be assayed for antibiotic susceptibility. Although appropriate systemic antibiotics are essential for the treatment of deteriorating, clinically infected wounds, debate exists regarding the relevance and use of antibiotics (systemic or topical) and antiseptics (topical) in the treatment of nonhealing wounds that have no clinical signs of infection. In providing a detailed analysis of wound microbiology, together with current opinion and controversies regarding wound assessment and treatment, this review has attempted to capture and address microbiological aspects that are critical to the successful management of microorganisms in wounds.

Anti-Bacterial Agents↗
PubMed2001

Functional status of persons with diabetes-related lower-extremity amputations.

OBJECTIVE: It is reasonable to predict that diabetes-related lower-extremity amputations have a detrimental impact on quality of life. However, we are unaware of any study in the medical literature describing the functional level of diabetic patients with amputations. The objective of this study was to evaluate amputations among diabetic patients and to determine the functional level of these patients with the Sickness Impact Profile (SIP). RESEARCH DESIGN AND METHODS: We enrolled 124 patients with diabetes. Case subjects (n = 35) were defined as patients who had undergone amputation of the lower-extremity, and control subjects (n = 89) were defined as patients who had not undergone amputation. Study participants received a standard history and physical examination. RESULTS: Both the physical dimension scores (33.5 +/- 14.9 vs. 22.3 +/- 14.7, P < 0.001) and the total SIP scores (27.6 +/- 9.9 vs. 22.5 +/- 10.3, P = 0.013) were significantly higher for amputees. However, the psychosocial dimension scores were not significantly different between case and control subjects (14.9 +/- 8.9 vs. 15.2 +/- 10.0, P > 0.05). Post hoc analysis showed that the group of patients who had undergone transtibial amputation had a significantly higher total impairment score than patients who had not undergone amputation (P = 0.039). This is in contrast to patients with toe or midfoot amputations, for whom total impairment scores were not significantly higher than those for the control subjects. Interestingly, bilateral amputees did not have significantly higher scores on either SIP dimension compared with unilateral amputees. CONCLUSIONS: These findings exemplify the detrimental physical and psychosocial health status of patients with diabetes-related lower-extremity amputation.

Activities of Daily Living↗
PubMed2001

Graftskin, a human skin equivalent, is effective in the management of noninfected neuropathic diabetic foot ulcers: a prospective randomized multicenter clinical trial.

OBJECTIVE: We assessed in a randomized prospective trial the effectiveness of Graftskin, a living skin equivalent, in treating noninfected nonischemic chronic plantar diabetic foot ulcers. RESEARCH DESIGN AND METHODS: In 24 centers in the U.S., 208 patients were randomly assigned to ulcer treatment either with Graftskin (112 patients) or saline-moistened gauze (96 patients, control group). Standard state-of-the-art adjunctive therapy, which included extensive surgical debridement and adequate foot off-loading, was provided in both groups. Graftskin was applied at the beginning of the study and weekly thereafter for a maximum of 4 weeks (maximum of five applications) or earlier if complete healing occurred. The major outcome of complete wound healing was assessed by intention to treat at the 12-week follow-up visit. RESULTS: At the 12-week follow-up visit, 63 (56%) Graftskin-treated patients achieved complete wound healing compared with 36 (38%) in the control group (P = 0.0042). The Kaplan-Meier median time to complete closure was 65 days for Graftskin, significantly lower than the 90 days observed in the control group (P = 0.0026). The odds ratio for complete healing for a Graftskin-treated ulcer compared with a control-treated ulcer was 2.14 (95% CI 1.23-3.74). The rate of adverse reactions was similar between the two groups with the exception of osteomyelitis and lower-limb amputations, both of which were less frequent in the Graftskin group. CONCLUSIONS: Application of Graftskin for a maximum of 4 weeks results in a higher healing rate when compared with state-of-the-art currently available treatment and is not associated with any significant side effects. Graftskin may be a very useful adjunct for the management of diabetic foot ulcers that are resistant to the currently available standard of care.

Adolescent↗
PubMed2001

Off-loading the diabetic foot wound: a randomized clinical trial.

OBJECTIVE: To compare the effectiveness of total-contact casts (TCCs), removable cast walkers (RCWs), and half-shoes to heal neuropathic foot ulcerations in individuals with diabetes. RESEARCH DESIGN AND METHODS: In this prospective clinical trial, 63 patients with superficial noninfected, nonischemic diabetic plantar foot ulcers were randomized to one of three off-loading modalities: TCC, half-shoe, or RCW. Outcomes were assessed at wound healing or at 12 weeks, whichever came first. Primary outcome measures included proportion of complete wound healing at 12 weeks and activity (defined as steps per day). RESULTS: The proportions of healing for patients treated with TCC, RCW, and half-shoe were 89.5, 65.0, and 58.3%, respectively. A significantly higher proportion of patients were healed by 12 weeks in the TCC group when compared with the two other modalities (89.5 vs. 61.4%, P = 0.026, odds ratio 5.4, 95% CI 1.1-26.1). There was also a significant difference in survival distribution (time to healing) between patients treated with a TCC and both an RCW (P = 0.033) and half-shoe (P = 0.012). Patients were significantly less active in the TCC (600.1 +/- 320.0 daily steps) compared with the half-shoe (1,461.8 +/- 1,452.3 daily steps, P = 0.04). There was no significant difference in the average number of steps between the TCC and the RCW (767.6 +/- 563.3 daily steps, P = 0.67) or the RCW and the half-shoe (P = 0.15). CONCLUSIONS: The TCC seems to heal a higher proportion of wounds in a shorter amount of time than two other widely used off-loading modalities, the RCW and the half-shoe.

Casts, Surgical↗
PubMed2001

Continuous activity monitoring in persons at high risk for diabetes-related lower-extremity amputation.

This study evaluated the magnitude and location of activity of diabetic patients at high risk for foot amputation. Twenty subjects aged 64.6 +/- 1.8 years with diabetes, neuropathy, deformity, or a history of lower-extremity ulceration or partial foot amputation were dispensed a continuous activity monitor and a log book to record time periods spent in and out of their homes for 1 week. The results indicate that patients took more steps per hour outside their home, but took more steps per day inside their homes. Although 85% of the patients wore their physician-approved shoes most or all of the time while they were outside their homes, only 15% continued to wear them at home. Focusing on protection of the foot during in-home ambulation may be an important factor on which to focus future multidisciplinary efforts to reduce the incidence of ulceration and amputation. The ability to continuously monitor the magnitude, duration, and time of activity ultimately may assist clinicians in dosing activity just as they dose drugs.

Aged↗
PubMed2001

Is diabetic foot care efficacious or cost effective?

The incidence of diabetes-related lower extremity amputations continues to increase in the developed and developing world, costing nearly $2 billion and an estimated 2,600 patient-years of hospital stay per year in the United States alone. However, the federal government and private healthcare providers fail to place preventative intervention high on their respective healthcare policy agendas. This manuscript briefly evaluates literature that might support or refute the value of structured, regular care of the diabetic foot and wound. Although the literature is still glaringly sparse, an emerging body of research supports the fact that aggressive, proactive care may result in fewer lower extremity amputations and possibly a higher quality and quantity of life for patients with diabetes.

Amputation, Surgical↗
PubMed2000

Improvement in healing with aggressive edema reduction after debridement of foot infection in persons with diabetes.

BACKGROUND: Infected foot wounds in patients with diabetes are the most common reason for diabetes-related hospital admission in the United States. Nonhealing foot wounds are the major precipitant of lower-extremity amputation in the diabetic population. HYPOTHESIS: The null hypothesis was that there would be no difference in proportion of healing with or without use of a foot-level mechanical compression device. DESIGN: Twelve-week, double-blind, randomized, controlled trial. SETTING: A university teaching hospital and related clinics. PATIENTS: One hundred fifteen patients with diabetes, 74% male, with foot infections requiring incision and debridement. INTERVENTION: All patients received either a functioning or placebo (nonfunctioning) foot compression device (Kinetic Concepts Inc, San Antonio, Tex). Patients and investigators were blinded to the functionality of the device. PRIMARY OUTCOME MEASURE: Proportion of wound healing in each group. RESULTS: There was a significantly higher proportion of healing in the active group than in the placebo group (39 [75%] of 52 patients vs 23 [51%] of 45; chi(2) = 6.0; P<.02; odds ratio, 2.9; 95% confidence interval, 1. 2-6.8). In the placebo group, there was no difference in proportion of healing between those identified as compliant (>/=50 hours of use per week) vs noncompliant (P =.10). In patients receiving active units, more patients in the compliant subgroup experienced wound healing (P<.03). When compared as a whole, there was a significant trend toward an increasing proportion of healing from the placebo-noncompliant to the placebo-compliant to the active-noncompliant to the active-compliant groups (chi(2)(trend) = 8.3; P<.005). CONCLUSIONS: Edema reduction achieved in this study by way of a pump and wrap system may increase the proportion of wound healing in patients after debridement of foot infections in patients with diabetes. Furthermore, the data suggest a potential association between increased compliance with use of the device and an increased trend toward wound healing. Arch Surg. 2000;135:1405-1409

Debridement↗
PubMed2000

Reliability of digital videometry and acetate tracing in measuring the surface area of cutaneous wounds.

PURPOSE: The purpose of this study was to evaluate the reliability of digital videometry and acetate tracing in the measurement of cutaneous wound area. METHODS: Four clinicians used both digital videometry and acetate tracing to measure five wounds that were artificially created on a cadaver specimen. In addition, the clinicians used an analog centimeter ruler to determine a rough estimate of the area of each wound. The wounds were measured a total of five times with each measurement instrument using a non-sequential repeat measures design. Associations between the three wound measurement techniques were examined with Pearson correlation coefficients. In addition, intraclass correlation coefficients (ICC) were calculated for each pair of the three measurement techniques. RESULTS: Correlation between the measurement systems for all raters combined yielded Pearson r-values of 0.93 for ruler and acetate, 0.95 for ruler and digital and 0.97 for acetate and digital. Furthermore, the average measure ICC between acetate and digital was 0.94, between acetate and ruler was 0.76 and between digital and ruler was 0.57. CONCLUSION: These results suggest that wound area measurements obtained using digital videometry and acetate tracing are very similar and both techniques can be used interchangeably in either clinical or research settings.

Acetates↗
PubMed2000

Angiogenesis in the human corpus luteum: localization and changes in angiopoietins, tie-2, and vascular endothelial growth factor messenger ribonucleic acid.

In the menstrual cycle, extensive angiogenesis accompanies luteinization. During luteolysis, endothelial cells die, whereas in a conceptual cycle, the corpus luteum (CL) persists, and endothelial cell survival is extended. A main stimulator for angiogenesis is vascular endothelial growth factor (VEGF), while the angiopoietins (Ang-1 and Ang-2) may be important modulators. The aim of this study was to investigate the localization of Ang-1, Ang-2, their common receptor Tie-2, and VEGF messenger ribonucleic acid (mRNA) at the different stages of the functional luteal phase and after rescue by hCG. Ang-1 mRNA was uniformly expressed at a low level throughout the CL. The signal was highest during the early luteal phase. In contrast, Ang-2 mRNA expression was localized strongly to individual granulosa and thecal luteal and endothelial cells. Administration of hCG was associated with an increase in the Ang-2 mRNA area of expression and grain density in individual luteal and endothelial cells. The Tie-2 receptor mRNA was localized in endothelial cells, and the area of expression was highest during the early luteal phase and during luteal rescue. VEGF mRNA was found exclusively in granulosa luteal cells, and the area of expression was highest in corpora lutea during simulated pregnancy. These results begin to characterize the molecular regulation of the divergent processes involved in luteal angiogenesis during luteinization, luteolysis, and rescue in the human and imply that the angiopoietins are involved during the initial angiogenic phase and in luteal rescue.

Adult↗
PubMed2000

Expression of mRNA encoding IGF-I, IGF-II and type 1 IGF receptor in bovine ovarian follicles.

IGFs regulate gonadotrophin-stimulated proliferation and differentiation of granulosa and theca cells in vitro. However, the detailed pattern of mRNA expression of IGFs in bovine follicles remains controversial. The objectives of this study were therefore to describe the temporal and spatial pattern of expression of mRNA encoding IGF-I, IGF-II and the type 1 IGF receptor in bovine follicles in vivo. The expression of mRNA encoding IGF-II was detected in theca tissue from around the time of antrum formation up to and during the development of dominance. No IGF-II mRNA expression was detected in granulosa cells. In the majority of follicles we were unable to detect mRNA encoding IGF-I in either granulosa or theca tissue from follicles at any stage of development. Occasionally low amounts of mRNA encoding IGF-I were detected in the theca externa and connective tissue surrounding some follicles. Type 1 IGF receptor mRNA was detected in both granulosa and theca cells of preantral and antral follicles. Expression was greater in granulosa tissue compared with theca tissue. We also measured IGF-I and -II mRNA in total RNA isolated from cultured granulosa and theca cells using reverse transcriptase PCR. In contrast to the in vivo results, IGF-II mRNA was detected in both granulosa and theca tissue. IGF-I mRNA was detected in theca tissue and in very low amounts in granulosa cells. Using a specific IGF-I RIA we were unable to detect IGF-I immunoreactivity in granulosa conditioned cell culture media. Using immunohistochemistry we detected IGF-I immunoreactivity in some blood vessels within the ovarian stroma. We conclude from these results that IGF-II is the principal intrafollicular IGF ligand regulating the growth of bovine antral follicles. In preantral follicles the expression of mRNA encoding type 1 IGF receptor but absence of endogenous IGF-I or -II mRNA expression, highlights a probable endocrine mechanism for the IGF regulation of preantral follicle growth.

Animals↗
PubMed2000

Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial.

OBJECTIVE: Diabetic foot ulceration is a preventable long-term complication of diabetes. A multicenter prospective follow-up study was conducted to determine which risk factors in foot screening have a high association with the development of foot ulceration. RESEARCH DESIGN AND METHODS: A total of 248 patients from 3 large diabetic foot centers were enrolled in a prospective study. Neuropathy symptom score, neuropathy disability score (NDS), vibration perception threshold (VPT), Semmes-Weinstein monofilaments (SWFs), joint mobility, peak plantar foot pressures, and vascular status were evaluated in all patients at the beginning of the study. Patients were followed-up every 6 months for a mean period of 30 months (range 6-40), and all new foot ulcers were recorded. The sensitivity, specificity, and positive predictive value of each risk factor were evaluated. RESULTS: Foot ulcers developed in 95 feet (19%) or 73 patients (29%) during the study. Patients who developed foot ulcers were more frequently men, had diabetes for a longer duration, had nonpalpable pedal pulses, had reduced joint mobility, had a high NDS, had a high VPT, and had an inability to feel a 5.07 SWE NDS alone had the best sensitivity, whereas the combination of the NDS and the inability to feel a 5.07 SWF reached a sensitivity of 99%. On the other hand, the best specificity for a single factor was offered by foot pressures, and the best combination was that of NDS and foot pressures. Univariate logistical regression analysis yielded a statistically significant odds ratio (OR) for sex, race, duration of diabetes, palpable pulses, history of foot ulceration, high NDSs, high VPTs, high SWFs, and high foot pressures. In addition, 94 (99%) of the 95 ulcerated feet had a high NDS and/or SWF which resulted in the highest OR of 26.2 (95% CI 3.6-190). Furthermore, in multivariate logistical regression analysis, the only significant factors were high NDSs, VPTs, SWFs, and foot pressures. CONCLUSIONS: Clinical examination and a 5.07 SWF test are the two most sensitive tests in identifying patients at risk for foot ulceration, especially when the tests are used in conjunction with each other. VPT measurements are also helpful and can be used as an alternative. Finally, foot pressure measurements offer a substantially higher specificity and can be used as a postscreening test in conjunction with providing appropriate footwear.

Adult↗