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Biomedical subjects

N Sims

Publications and source records attributed to N Sims.

11 recordsLinked to original sources
PubMed2006

Hand volume estimates based on a geometric algorithm in comparison to water displacement.

Assessing changes in upper extremity limb volume during lymphedema therapy is important for determining treatment efficacy and documenting outcomes. Although arm volumes may be determined by tape measure, the suitability of circumference measurements to estimate hand volumes is questionable because of the deviation in circularity of hand shape. Our aim was to develop an alternative measurement procedure and algorithm for routine use to estimate hand volumes. A caliper was used to measure hand width and depth in 33 subjects (66 hands) and volumes (VE) were calculated using an elliptical frustum model. Using regression analysis and limits of agreement (LOA), VE was compared to volumes determined by water displacement (VW), to volumes calculated from tape-measure determined circumferences (VC), and to a trapezoidal model (VT). VW and VE (mean +/- SD) were similar (363 +/- 98 vs. 362 +/-100 ml) and highly correlated; VE = 1.01VW -3.1 ml, r=0.986, p<0.001, with LOA of +/- 33.5 ml and +/- 9.9 %. In contrast, VC (480 +/- 138 ml) and VT (432 +/- 122 ml) significantly overestimated volume (p<0.0001). These results indicate that the elliptical algorithm can be a useful alternative to water displacement when hand volumes are needed and the water displacement method is contra-indicated, impractical to implement, too time consuming or not available.

Adult↗
PubMed2005

Foot volume estimates based on a geometric algorithm in comparison to water displacement.

Assessing lower extremity limb volume and its change during and after lymphedema therapy is important for determining treatment efficacy and documenting outcomes. Although leg volumes may be determined by tape measure and other methods, there is no metric method to routinely assess foot volumes. Exclusion of foot volumes can under- or overestimate therapeutic progress. Our aim was to develop and test a metric measurement procedure and algorithm for practicing therapists to use to estimate foot volumes. The method uses a caliper and ruler to measure foot dimensions at standardized locations and calculates foot volume (VM) by a mathematical algorithm. VM was compared to volumes measured by water displacement (Vw) in 30 subjects (60 feet) using regression analysis and limits of agreement (LOA). Vw and VM (mean +/- sd) were similar 857 +/- 150 ml vs. 859 +/- 154 ml, and were highly correlated VM = 1.00Vw + 1.67 ml, r = 0.965, p < 0.001. The LOA for absolute volume differences and percentages were respectively +/- 79.6 ml and +/- 9.28 %. These results indicate that this metric method can be a useful alternative to water displacement when foot volumes are needed, but the water displacement method is contraindicated, impractical to implement, too time consuming or is not available.

Adult↗
PubMed2005

Transcutaneous oxygen tension in arms of women with unilateral postmastectomy lymphedema.

Previous reports suggest that skin blood flow is reduced in arms of women with lymphedema due to breast cancer treatment. Since tissue oxygenation depends on blood flow, we sought to determine if transcutaneous oxygen tension (TcPO2) is also reduced and if so, if therapy that reduces edema has a beneficial effect. TcPO2 was measured in fibrotic areas of affected arms and in corresponding sites on non-affected arms of 15 women with unilateral arm lymphedema before and after CDP therapy sequences. Fibrosis was assessed by indentation recovery times (IRT) after applying an indenter-like device to tissue. Volumes and edema percentages were determined from circumferences using automated software calculations. Treatment significantly (p < 0.01) reduced arm edema from 28.6 +/- 22.9% to 18.1 +/- 17.7% (mean +/- SD) and fibrotic segment edema from 42.6 +/- 30.1% to 25.0 +/- 20.4%, and softened fibrotic tissue judged by reductions in IRT (88.7 +/- 60.7 sec vs. 23.1 +/- 38.8 sec, p < 0.001). TcPO2 did not differ between arms initially and did not change with treatment, being 60.1 +/- 8.8 mmHg at the start and 61.8 +/- 9.2 mmHg at the end of treatment. Thus, despite significant amounts of initial edema, TcPO2 was not initially less in affected arms nor was it changed by therapy that improved both edema and fibrosis.

Aged↗
PubMed2000

Quantitative and functional characterization of muscarinic receptor subtypes in insulin-secreting cell lines and rat pancreatic islets.

Expression of muscarinic receptors in rat islets, RINm5F cells, and INS-1 cells was established by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantified by RNase protection. Both methods indicated that m3 and m1 receptors were expressed approximately equally in the various cellular preparations and to a much greater extent than the m5 subtype. However, the cell lines, especially RINm5F cells, expressed less of a given receptor subtype than did islets. Immunohistochemistry indicated that m3 receptors were expressed throughout the islet core. Binding studies using the radiolabeled muscarinic receptor antagonist QNB demonstrated a maximal binding capacity of INS-1 cells of 23.0+/-2.9 fmol/mg protein. Functional analyses were undertaken using INS-1 cells stably transfected with either m1 or m3 receptor cDNAs. Overexpression of either receptor did not affect basal responses but markedly enhanced maximal responses to the muscarinic receptor agonist carbachol. Although maximal hydrolysis of phosphatidylinositol 4,5-bisphosphate (Ptd InsP2) was twofold greater in m1-transfectants as compared with m3-transfectants, cell lines overexpressing either receptor gave essentially equivalent secretory responses to a full range of carbachol doses. The results demonstrate that both m1 and m3 muscarinic receptors are well expressed in pancreatic beta-cells, functionally linked to signaling pathways, and capable of initiating insulin secretion with equal potencies.

Animals↗
PubMed1991

A flexible system for vital signs monitoring in hospital general care wards based on the integration of UNIX-based workstations, standard networks and portable vital signs monitors.

The article describes a study conducted on general surgical and thoracic surgical floors of a 1000-bed hospital to assess the impact of a new network for portable patient care devices. This network was developed to address the needs of hospital patients who need constant, multi-parameter, vital signs surveillance, but do not require intensive nursing care. Bedside wall jacks were linked to UNIX-based workstations using standard digital network hardware, creating a flexible system (for general care floors of the hospital) that allowed the number of monitored locations to increase and decrease as patient census and acuity levels varied. It also allowed the general care floors to provide immediate, centralized vital signs monitoring for patients who unexpectedly became unstable, and permitted portable monitors to travel with patients as they were transferred between hospital departments. A disk-based log within the workstation automatically collected performance data, including patient demographics, monitor alarms, and network status for analysis. The log has allowed the developers to evaluate the use and performance of the system.

Boston↗
PubMedDate not supplied

The effect of anesthetic patient education on preoperative patient anxiety.

BACKGROUND AND OBJECTIVES: Preoperative time spent with patients has been abbreviated with the advent of same-day admission requirements and outpatient surgery. This study was conducted to evaluate the effects that materials mailed to the home relating to anesthetic-focused patient education may have on preoperative patient anxiety. METHODS: Patients scheduled for a total hip arthroplasty or for a total knee arthroplasty were screened via telephone for inclusion in a prospective, randomized study. Patients were asked about their access to a video cassette recorder/player (VCR) and their limitations regarding hearing or vision. Subjects were randomly assigned to either the intervention group and received two pamphlets and a video describing general and regional anesthesia or to the usual care group. All subjects were mailed a preoperative demographic questionnaire and a State Trait Anxiety Inventory (STAI), as developed by CD Spielberger. Questionnaires were completed at least 96 hours prior to admission and again preoperative on the day of surgery. RESULTS: Of 236 patients screened, 26 had no access to a VCR, 6 were hearing or visually impaired, and 4 declined participation. Of 200 subjects randomized, 134 completed both sets of questionnaires and thus form the basis of this report. A statistically significant difference between the subjects who received the video and pamphlets and the usual care subjects was detected with respect to change in STAI-assessed anxiety from baseline to immediately prior to surgery (P = .035). The intervention subjects experienced a smaller mean increase in anxiety. Forty-nine percent of the usual care subjects expressed interest in having additional information. CONCLUSIONS: Increase in preoperative anxiety is diminished when additional anesthesia information in printed and video format is made available. Useful information can be provided to patients to view or read prior to surgery.

Aged↗
PubMedDate not supplied

Biophysical effects of water and synthetic urine on skin.

OBJECTIVE: Pressure ulcers often occur at sites subjected to pressure and wetness. Although skin wetness is a risk factor for pressure ulcers,the mechanisms and effects of wetness versus urine constituents on skin breakdown is unclear. The hypothesis that wetness reduces skin hardness and, thereby, increases vulnerability of underlying blood vessels to pressure-induced flow reductions was tested in this study. DESIGN: Pads saturated with water and with a water solution mixed with the main chemical constituents of urine (synthetic urine; s-urine) were applied to forearm skin of 10 healthy subjects for 5.5 hours. Skin hardness, blood flow change caused by 60 mm Hg of pressure, erythema, and temperature were compared among dry, water, and s-urine test sites. PARTICIPANTS: 10 healthy women. SETTING: Research Center, Nova Southeastern University, Health Professions Division, Fort Lauderdale, FL. MAIN RESULTS: S-urine and water caused significant reductions in initial hardness and caused greater initial perfusion decreases during pressure load when compared with dry sites. Skin temperature and erythema were lower at wet sites when compared with dry sites. CONCLUSIONS: The findings of this study are consistent with the concept that sustained skin wetness increases vulnerability to pressure-induced blood flow reduction. The effect appears to be mainly dependent on wetness, but urine constituents may exacerbate the effect. In addition, wetness-related skin cooling may play a role. In the healthy subjects studied, the blood flow decrease was not sustained due to perfusion recovery under pressure. Skin wetness would likely have more sustained effects in patients with compromised recovery mechanisms. Measures to diminish skin exposure to wetness in these patients, whatever the wetness source, are an important consideration in a multifaceted strategy to reduce the risk of pressure ulcers.

Administration, Cutaneous↗
PubMedDate not supplied

Assessment of limb volume by manual and automated methods in patients with limb edema or lymphedema.

OBJECTIVE: Limb edema and lymphedema due to chronic venous insufficiency or mastectomy and radiotherapy negatively effects patient well-being, lifestyle, tissue blood flow, oxygenation, and wound healing. Assessment of the efficacy of volume reduction therapy requires adequate estimation of progressive limb-segment volume changes, which are usually done manually with a tape measure. This study investigated the possibility that an optoelectronic automated method--a potentially less time-consuming and less operator-dependent method--might provide adequate limb volume assessment. DESIGN: A total of 184 manual and automated measurements of limb volume were made in 62 consecutive patients with limb edema of the legs (n = 142) and arms (n = 42). SETTING: Clinical center. RESULTS: Comparisons between automated and manual methods showed that inter-method volume estimates were highly correlated (4.14 +/- 0.54% for legs; 6.97 +/- 1.18% for arms). In patients with unilateral edema, the affected limb's percentage of edema was virtually identical when estimated by each method. CONCLUSION: These findings show that the automated method of measuring limb volume is a useful alternative in suitable patients in clinical and research applications.

Anthropometry↗