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Biomedical subjects

L D Broemeling

Publications and source records attributed to L D Broemeling.

At least 19 recordsLinked to original sources
PubMed2001

Coronary artery calcium, coronary artery disease, and diabetes.

Diabetes is a known risk factor for cardiovascular disease, which is the leading cause of death in the US. Most sufferers are unaware that they have coronary artery disease, and death is often quite sudden. Electron beam computed tomography (EBCT) is a non-invasive procedure that detects coronary artery disease (CAD) by measuring the amount of coronary artery calcium (CAC). We employ this procedure to study the effect of diabetes on CAC. EBCT was employed to measure the amount of coronary artery calcium in a population of 3389 patients referred to the Spokane Coronary Artery Center. This was a cross-sectional study. The average and median CAC values were computed for two groups of patients, namely those with diabetes and those without. Patients were also divided by gender and five age groups (0-39, 40-49, 50-59, 60-69, and >69 years). The mean and median CAC values were much larger for those with diabetes compared to those without for all age groups and in both sexes. Both men and women with diabetes have a greater plaque burden, when compared to a population with coronary artery disease with no history of diabetes. This plaque burden is greater in males than in females. CAC may play a useful role in following the progression of CAD in patients with diabetes, as well as evaluating the influence of risk factor intervention and diabetic control.

Adolescent↗
PubMed2001

Risk factors and coronary artery disease for asymptomatic women using electron beam computed tomography.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death for men and women in the United States. In 1995, 58,200,000 people were estimated to have the disease, claiming 960,592 lives, while 481,287 people died of coronary artery disease (CAD). Most people are unaware they have CAD, and death is often quite sudden. With more women surviving to old age, the absolute number of women dying from CVD exceeds that of men. METHODS: The study is cross-sectional. Electron beam computed tomography (EBCT) was employed to measure the amount of coronary artery calcium (CAC), a marker for CAD, in a population of patients referred to the Spokane Coronary Artery Center. A questionnaire was administered at the time of the patient's visit, when exposure to traditional risk factors was assessed. The effect of traditional risk factors on CAC was then determined. RESULTS: The effect of past smoking on CAC was evident, the effect of total cholesterol on CAC was moderate, while a history of hypertension appears to have an effect on the disease for older women. CONCLUSIONS: EBCT measurements of CAC can detect the effect of traditional risk factors on CAD and can be used to manage the disease in women.

Adult↗
PubMed2000

A bayesian analysis for spatial processes with application to disease mapping.

In epidemiology, maps of disease rates and disease risk provide a spatial perspective for researching disease aetiology. For rare diseases or when the population base is small, the rate and risk estimates may be unstable. We propose using a Bayesian analysis based on the conditional autoregressive (CAR) process that will spatially smooth disease rates or risk estimates by allowing each site to 'borrow strength' from its neighbours. Covariates may be included in the model in such a way as to establish a possible association between risk factors and disease incidence. Bayesian inferences are implemented from a direct resampling scheme where large samples are generated from the various posterior distributions. The methodology is demonstrated with a simulation that assesses the effect of sample size and the model parameters on inferences for the parameters. Our approach is also used to spatially smooth district lip cancer rates in Scotland using the CAR model with a covariate that allows for exposure to sunlight.

Bayes Theorem↗
PubMed1997

A Bayesian analysis of regression models with continuous errors with application to longitudinal studies.

We employ a regression model with errors that follow a continuous autoregressive process to analyse longitudinal studies. In this way, unequally spaced observations do not present a problem in the analysis. We employ a Bayesian approach, where our inferences are based on a direct resampling process that generates values from the posterior distribution of the parameters of the model. We illustrate these Bayesian inferences with an analysis of a longitudinal study that involves the regression of foetal head circumference on menstrual age. Using these same data, we contrast the Bayesian approach with a maximum likelihood technique.

Bayes Theorem↗
PubMed1997

Dietary L-histidine regulates murine skin levels of trans-urocanic acid, an immune-regulating photoreceptor, with an unanticipated modulation: potential relevance to skin cancer.

Solar ultraviolet-B radiation (UVB; 290-320 nm) causes skin cancer and suppresses cell-mediated immunity, preventing the rejection of UV-induced tumors. One mechanism initiating UV suppression involves the trans to cis photoisomerization of urocanic acid (UCA), a histidine derivative found in the stratum corneum. The addition of L-histidine to nonpurified mouse diet has been shown to increase skin trans-UCA levels and sensitivity to UVB immune suppression. Specially formulated L-histidine diets (0.40-64 g/kg) fed to BALB/c mice that were monitored over a 19-wk period resulted in an unexpected modulation of skin trans-UCA. ANOVA revealed a group-time interaction, providing initial evidence that the skin levels of trans-UCA were modulating up and down in all groups except the control group (6.4 g/kg diet). We observed that both high (64 g/kg diet) and low (0.4 g/kg diet) levels of dietary L-histidine resulted in the increase of skin trans-UCA to levels significantly higher than those recorded in the control group. In mice fed these histidine levels, skin trans-UCA increased to between 2.9 and 3.6 nmol/mg skin (64 g/kg diet, over 5 wk; 0.4 g/kg diet, over 8 wk) and then decreased to approximately 1.69 nmol/mg skin, the base-line level (64 g/kg diet, over 11 wk; 0.4 g/kg diet, over 17 wk). The increase in trans-UCA levels in mice with low L-histidine intake may be the result of protein malnutrition, consistent with weight loss observed in those mice. The modulation of trans-UCA levels in skin by dietary L-histidine has not been previously described; its role in skin cancer development is under investigation.

Administration, Oral↗
PubMed1996

Beneficial effect of Aloe on wound healing in an excisional wound model.

Recent evidence from in vitro and in vivo experiments suggests that topical antimicrobials may be toxic to fibroblasts and keratinocytes and retard wound healing. The purpose of this study was to determine the effects of Aloe, a potential wound-healing agent, on wound contraction in excisional wounds treated with topical antimicrobials. Sprague-Dawley rats were prepared with four 1.5 cm2 dorsal defects through the skin and panniculus. The animals were divided into five groups (n = 10 per group): (1) Aloe, (2) NaOCl solution (0.025%), (3) mafenide acetate, (4) mafenide acetate + Aloe, and (5) control. Wounds were treated topically for 14 days 3 times a day. Serial standard photographs and serial wound planimetry were performed weekly. Following healing, the breaking strength of each resultant scar was determined using an Instron tensiometer. Kruskal-Wallis, ANOVA, and multiple comparison methods were used for data analysis. Aloe and NaOCl solution significantly accelerated wound contraction (p < 0.05). In the mafenide acetate + Aloe group, contraction was similar to the control, whereas the mafenide acetate alone retarded wound healing. The addition of Aloe in combination and alone in wounds increased the breaking energy when compared to controls (p < 0.05). Aloe appears to expedite wound contraction and neutralize the wound retardant effect seen with the topical mafenide acetate alone. This effect appears to be due to an increased collagen activity, which is enhanced by a lectin, consequently improving the collagen matrix and enhancing the breaking strength.

Aloe↗
PubMed1996

Radiological and clinical criteria for the management of epidural hematomas in children.

OBJECTIVE: Modern neuroimaging and intensive care permit precise delineation and specific treatment of head injury. Children sustaining cranial trauma associated with epidural hematoma (EDH) represent a heterogeneous group with a variety of clinical outcomes. Treatment consists of simple observation or surgical evacuation. We attempted to define radiological characteristics of the EDH patients that underwent surgical evacuation. METHODS: We reviewed the records and computed tomography scans of 33 children sustaining cranial trauma associated with EDH treated at the Children's National Medical Center between October 1990 and August 1994. The radiological and clinical characteristics of children treated surgically (n = 13) and nonsurgically (n = 20) were compared. RESULTS: Mass effect, a temporal clot location, thickness, length and volume of the clot, and midline shift (p < 0.05) differed significantly between groups. The most important radiological parameters in determining the therapeutic intervention were thickness, midline shift, mass effect, and EDH location. A thickness of the EDH > 18 mm, a midline shift >4 mm, and moderate or severe mass effect correctly predicted therapy in 29 out of 33 patients. By adding the location as a fourth parameter, therapy was accuratly predicted in 31 of 33 patients. Mechanism of injury, interval from injury to initial computed tomography scan, age, sex, Glasgow coma score on admission, or lengths of hospital and intensive care unit stays were not significantly different between groups. CONCLUSION: Although radiological criteria predict surgical intervention for larger EDH, patients harboring intermediate-size EDH will continue to require careful individualized clinical judgement.

Child↗
PubMed1995

Long-term reduction in bone mass after severe burn injury in children.

OBJECTIVE: Because burn victims are at risk of having bone loss, a cross-sectional study was undertaken to determine whether severe burn injury had acute and long-term effects on bone mass or on the incidence of fractures in children. METHODS: Dual-energy x-ray absorptiometry of the lumbar portion of the spine was performed on 68 children: 16 moderately burned (15% to 36% of total body surface area) and 52 age-matched severely burned (> or = 40% of total body surface area). Twenty-two severely burned children were hospitalized and studied within 8 weeks of their burn, and 30 others were studied approximately 5 years after discharge. In the severely burned group, both hospitalized and discharged, serum and urine were analyzed for calcium, phosphorus, intact parathyroid hormone, osteocalcin, and type I collagen telopeptide. RESULTS: Sixty percent of severely burned patients had age-related z scores for bone density less than -1, and 27% of severely burned patients had age-related z scores for bone density less than -2 (p < 0.005, for each). In the moderately burned group, 31% of patients had z scores less than -1 (p < 0.005 vs normal distribution), but only 6% had z scores less than -2 (p value not significant). There was evidence of increased incidence of fractures after discharge in the severely burned patients. Biochemical studies were compatible with a reduction in bone formation and an increase in resorption initially, and with a long-term persistence of low formation. CONCLUSION: We conclude that acute burn injury leads to profound and long-term bone loss, which may adversely affect peak bone mass accumulation.

Acute Disease↗
PubMed1993

Association of rhinovirus infection with poor bacteriologic outcome of bacterial-viral otitis media.

Viruses--both alone and in combination with bacteria--have been shown to be a cause of acute otitis media (AOM). Moreover, the presence of virus in middle ear fluid (MEF) interferes with the bacteriologic response to antibiotic treatment in AOM. We studied various factors related to the eradication of bacteria from the MEF of infants and children who had AOM associated with a combination of bacteria and viruses. Of 622 cases of AOM diagnosed and treated between 1985 and 1991, 71 were due to such a combination. Bacteria were eradicated from MEF by 2-4 days of antibiotic treatment in 50 (70%) of these 71 cases; in the remaining 21 cases, the originally identified bacteria persisted or a new pathogenic bacterial species was detected after such treatment. These two groups of cases were compared with respect to the patients' age, sex, race, history of recurrent AOM, duration of respiratory symptoms, and compliance; the type of antibiotic treatment administered; the type of pathogenic bacteria and viruses identified in MEF; the presence of single or multiple pathogens; and the laterality of the disease. The only difference noted was in the type(s) of virus found in MEF. The presence of rhinovirus was associated with a higher rate of bacteriologic failure than was that of respiratory syncytial virus, parainfluenza virus, influenza virus, or other viruses. Our data suggest that the bacteriologic response to antibiotic treatment in bacterial-viral AOM may depend in part on the type(s) of virus present in MEF.

Anti-Bacterial Agents↗
PubMed1993

Application of basic fibroblast growth factor may reverse diabetic wound healing impairment.

This study examines the effect of application of basic fibroblast growth factor (bFGF) on the wound healing impairment seen in streptozotocin-induced diabetic (SD) rats compared with control nondiabetic (NL) animals. Under general anesthesia, a 6-cm dorsal incision was made through the skin and panniculus carnosus. Both the NL and SD wounds were injected with 0.1 ml of one of the following three solutions: saline, vehicle, and 10 micrograms of bFGF. The wounds were closed with interrupted sutures of 4-0 nylon. The animals were returned to their cages and sacrificed at 7, 10, 14, or 21 days later. Breaking strength of the wound was analyzed by using an Instron Tensiometer 4201 to assay for relative collagen maturation. Data among groups were compared using an analysis of variance. At 7 and 10 days, all NL wounds were stronger than all SD wounds. By 14 days there was no statistically significant difference in breaking strength between the bFGF-SD wounds and all subgroups of NL wounds. The bFGF-SD subgroup was statistically significantly stronger than the saline-SD (p < 0.02) and vehicle-SD (p < 0.01) wounds. At 21 days the bFGF-SD wounds were statistically significantly stronger than the vehicle-SD wounds to a confidence level of p < 0.001. These findings indicate that application of bFGF may reverse the impairment seen in diabetic wound healing.

Animals↗
PubMed1993

Measuring intrasubject variability: use of the jacknife in doubly labeled water experiments.

The doubly labeled water technique measures energy expenditure; however, very little has appeared in the literature regarding estimation of the intrasubject variation. By use of a statistical resampling procedure called the jackknife, the standard deviation of the determination of energy expenditure in each subject is evaluated. Jackknife methods exploit the regression techniques that are already used with the doubly labeled water technique and are very easy to implement. Estimates of sample sizes for future experiments can easily be done with the jackknife. These formulas give the number of determinations of isotopic enrichment of hydrogen and oxygen over time that are needed to achieve a given degree of accuracy in estimating energy expenditure. An example with two human subjects illustrates the methodology of the jackknife.

Body Water↗
PubMed1992

The safety and effect of topically applied recombinant basic fibroblast growth factor on the healing of chronic pressure sores.

The first randomized, blinded, placebo-controlled human trials of recombinant basic fibroblast growth factor (bFGF) for pressure sore treatment were performed. Three different concentrations of bFGF in five dosing schedules were tested for safety using hematology, serum chemistries, urinalysis, absorption, antibody formation, and signs of toxicity. Efficacy was evaluated by wound volumes, histology, and photography. No toxicity, significant serum absorption, or antibody formation occurred. In six of eight subgroups, there was a trend toward efficacy with bFGF treatment. When all subgroups were combined, comparison of the slopes of the regression curves of volume decrease over initial pressure sore volume demonstrated a greater healing effect for the bFGF-treated patients (p < 0.05). Histologically, bFGF-treated wound sections demonstrated increased fibroblasts and capillaries. More patients treated with bFGF achieved > 70% wound closure (p < 0.05). Blinded observers were able to distinguish differences in visual wound improvement between bFGF and placebo groups. These data suggest that bFGF may be effective in the treatment of chronic wounds.

Administration, Topical↗
PubMed1992

The effect of denervation on soft-tissue infection pathophysiology.

Pressure is the sine qua non in the etiology of pressure sores; however, ischemia, denervation, edema, and infection also have been implicated. The role of denervation in tissue infection was studied in an isolated in vivo ovine flap model. Twenty-six adult ewes, divided into three groups, had 29 island pedicle flaps raised on their buttocks. In group I, the cutaneous nerve remained intact, while group II had its nerve divided acutely. Group III had prolonged denervation, where the nerve was divided 7 days before flap elevation. All flaps received intradermal inoculations of 10(7) Staphylococcus aureus. Ninety-six hours later, quantitative bacteriology showed counts of 10(7), 10(7), and 10(9) colony-forming units (CFU) per gram of tissue in groups I, II, and III, respectively. Septic foci were larger in group III, and there was a significant increase in tissue edema between groups I and III. A 25-fold increase in bacterial counts seen in the prolonged denervation group may help explain why neurologically injured patients are more susceptible to infection and pressure ulcerations.

Abscess↗