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Biomedical subjects

E Saunders

Publications and source records attributed to E Saunders.

At least 19 recordsLinked to original sources
PubMed2001

Antihypertensive efficacy and safety of losartan alone and in combination with hydrochlorothiazide in adult African Americans with mild to moderate hypertension.

BACKGROUND: African Americans with hypertension, particularly those with more severe blood pressure elevations, are generally less responsive to monotherapy from any antihypertensive class. These patients usually require treatment with drugs from > or = 2 antihypertensive classes to achieve adequate blood pressure control. OBJECTIVE: The purpose of this study was to assess the antihypertensive efficacy and safety of losartan alone and in combination with hydrochlorothiazide (HCTZ) in African American adults with mild to moderate hypertension. METHODS: In this 12-week, multicenter, double-blind, randomized, parallel-group, placebo-controlled study, African American patients were randomized in a 3:3:1 ratio to I of 3 treatment groups: placebo, losartan monotherapy (50 to 150 mg), or losartan plus HCTZ (50/0 to 50/12.5 to 100/25 mg). Doses were titrated at weeks 4 and 8 if sitting diastolic blood pressure (SiDBP) was > or = 90 mm Hg. Safety was assessed by determining the incidence of clinical and laboratory Adverse events and evaluating mean changes in pulse, body weight, electrocardiographic parameters, and laboratory test results. RESULTS: A total of 440 patients were randomized-188 to placebo, 193 to losartan monotherapy, and 59 to losartan/HCTZ; 391 completed the study. At week 12, the response rate with losartan monotherapy was 45.8%, with a significant (P < or = 0.01) lowering in mean SiDBP by 6.6 mm Hg compared with placebo; the response rate with placebo was 27.2%, with a mean SiDBP reduction of 3.9 mm Hg. Sitting systolic blood pressure (SiSBP) was significantly lowered with losartan monotherapy, by 6.4 mm Hg, compared with placebo (reduction of 2.3 mm Hg). The response rate with losartan/ HCTZ was 62.7%, with reductions in SiSBP and SiDBP of 16.8 mm Hg and 10.8 mm Hg, respectively (P < or = 0.01 vs placebo and losartan monotherapy). The incidence of clinical adverse events was comparable in the 3 treatment groups. CONCLUSIONS: The results of this study suggest that in African American patients, losartan monotherapy was significantly more effective than placebo in lowering SiSBP and SiDBP. Moreover, the losartan/ HCTZ combination regimen resulted in significant and clinically meaningful additional reductions in SiSBP and SiDBP compared with losartan monotherapy or placebo. Losartan monotherapy and the losartan/HCTZ regimens were generally as well tolerated as placebo.

Black or African American↗
PubMed2001

Psychophysics of a prototype peri-modiolar cochlear implant electrode array.

Psychophysical measurements were performed in three hearing-impaired adult subjects implanted with a CI22 cochlear prosthesis (Cochlear Ltd.) fitted with a developmental peri-modiolar electrode array. The array was manufactured with a curvature approximating that of the inner wall of the scala tympani but, after straightening and insertion, lay on average about half way between the inner and outer walls of the scala. All subjects were tested with bipolar stimulation; two were also tested with monopolar, employing the most basal electrode as the return. Maximum comfortable level and threshold reduced with decreasing distance of electrode from the modiolus, whereas dynamic range increased. The linearity of the loudness growth function did not vary significantly with electrode position but the function was more non-linear for lower maximum comfortable levels. Current level discrimination, normalized with respect to dynamic range, improved with decreasing distance of electrode from the modiolus in two subjects. Pitch varied regularly with insertion depth of the stimulated electrode for bipolar stimulation in two subjects and also for monopolar stimulation in one subject. Electrode discrimination was enhanced by closeness to the modiolus. Whereas the forward masking patterns for bipolar stimulation of electrodes close to the modiolus had a sharp double-peaked structure, those for monopolar stimulation were flatter and had a single peak.

Adult↗
PubMed2001

The contour electrode array: safety study and initial patient trials of a new perimodiolar design.

OBJECTIVE: The aim of these studies was to investigate the insertion properties and safety of a new intracochlear perimodiolar electrode array design (Contour). BACKGROUND: An electrode array positioned close to the neural elements could be expected to reduce stimulation thresholds and might potentially reduce channel interaction. METHODS: Two sequential studies were conducted. In study 1, the Contour electrode array was inserted in 12 human temporal bones. After cochlear surface preparation, the position of the array was noted and the basilar membrane was examined for insertion damage. On the basis of the outcome of this temporal bone study, study 2 investigated the Contour array, mounted on a Nucleus CI-24 M device and implanted in three adult patients. RESULTS: Study I showed that in 10 temporal bones, the Contour array was positioned close to the modiolus, and the basilar membrane was intact. In the two remaining bones, the arrays had pierced the basilar membrane and were positioned in the scala vestibuli apical to the penetration. Statistical analysis showed an equivalent probability of insertion-induced damage of the two array designs. In study 2, image analysis indicated that the Contour electrodes were positioned closer to the modiolus than the standard Nucleus straight array. Lower T and C levels, but higher impedance values, were recorded from electrodes close to the modiolus. Initial speech perception data showed that all patients gained useful open-set speech perception, two patients achieving scores of 100% on sentence material 3 months postoperatively. CONCLUSIONS: The temporal bone studies showed the Contour electrode array to be generally positioned closer to the modiolus than the standard Nucleus straight array, and to have an equivalent probability of causing insertion-induced damage.

Acoustic Impedance Tests↗
PubMed2001

The role of radiographic phase-contrast imaging in the development of intracochlear electrode arrays.

OBJECTIVE: This study describes the application of a new radiographic imaging modality, phase-contrast radiography, to in vitro human temporal bone imaging and investigates its use in the development of new electrode arrays for cochlear implants. BACKGROUND: The development of perimodiolar electrode arrays for cochlear implants requires detailed information from postoperative radiologic assessment on the position of the array in relation to the cochlear structures. Current standard radiographic techniques provide only limited details. MATERIALS AND METHODS: Nucleus standard electrode arrays and perimodiolar Contour electrode arrays were implanted into the scala tympani of 11 human temporal bones. Both conventional and phase-contrast radiographs were taken of each temporal bone for comparative purposes. RESULTS: Phase-contrast imaging provides better visualization of anatomic details of the inner ear and of the structure of the intracochlear electrode array, and better definition of electrode location in relation to cochlear walls. CONCLUSION: Phase-contrast radiography offers significant improvement over conventional radiography in images of in vitro human temporal bones. It seems to be a valuable tool in the development of intracochlear electrode arrays and cochlear implant research. However, this new radiographic technique still requires certain computational and physics challenges to be addressed before its clinical use can be established.

Cochlea↗
PubMed2000

The rapidity of drug dose escalation influences blood pressure response and adverse effects burden in patients with hypertension: the Quinapril Titration Interval Management Evaluation (ATIME) Study. ATIME Research Group.

BACKGROUND: Antihypertensive medication doses are typically increased within several weeks after initiation of therapy because of inadequate blood pressure (BP) control and/or adverse effects. METHODS: We conducted a parallel-group clinical trial with 2935 subjects (53% women, n=1547) aged 21 to 75 years, with Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure VI stages 1 to 2 hypertension, recruited from 365 physician practices in the southeastern United States. Participants were randomized either to a fast (every 2 weeks; n=1727) or slow (every 6 weeks; n=1208) drug titration. Therapy with quinapril, an angiotensin-converting enzyme inhibitor, was initiated at 20 mg once daily. The dose was doubled at the next 2 clinic visits until the BP was lower than 140/90 mm Hg or a dose of 80 mg was reached. RESULTS: Pretreatment BP averaged 152/95 mm Hg. Patients with stage 2 hypertension reported more symptoms than those with stage 1. The BP averaged 140/86, 137/84, and 134/83 mm Hg in the slow group compared with 141/88, 137/85, and 135/84 mm Hg in the fast group at the 3 respective clinic visits. The BP control rates to lower than 140/90 mm Hg at the 3 clinic visits were (slow, fast, respectively) 41.3%, 35.7% (P<.001); 54.3%, 51.5% (P=.16); and 68%, 62.3% (P=.02). In the fast group, 10.7% of participants experienced adverse events vs 10.8% in the slow group; however, 21.0% of adverse events in the fast group were "serious" vs only 12% in the slow group. CONCLUSION: Slower dose escalation of the angiotensin-converting enzyme inhibitor quinapril provides higher BP control rates and fewer serious adverse events than more rapid drug dose escalation.

Adult↗
PubMed2000

Hypertension, chronotherapy, and patient management.

This article highlights information from a symposium held at the 1999 National Conference for Nurse Practitioners, Washington, D.C., November 11, 1999, sponsored by The Nursing Institute and supported by an unrestricted educational grant from Schwarz Pharma Inc. "Hypertension" was the first topic and was discussed by Elijah Saunders, MD, FACC, FACP. "Medical Chronobiology and Chronotherapy" was the second topic and was discussed by Michael H. Smolensky, PhD. The third topic, "The Nurse Practitioner and the Hypertensive Patient," was discussed by Helen C. Noel, ANP, PhD. Dr. Noel also served as chair of the symposium.

Adult↗
PubMed2000

Efficacy and safety of cerivastatin and pravastatin in the treatment of primary hypercholesterolemia.

In this randomized, double-blind, parallel group study, the efficacy and safety of cerivastatin (0.3 mg) and pravastatin (20 mg) were compared in 402 patients with primary hypercholesterolemia with and without documented coronary heart disease or peripheral vascular disease. After 8 weeks of treatment, cerivastatin provided significantly greater reductions than pravastatin in low-density lipoprotein (LDL)-cholesterol (31.1% vs. 26.0%; p < 0.0001) and total cholesterol (21.1% vs. 17.8%; p < 0.0001). A greater proportion of patients treated with cerivastatin than pravastatin achieved > 30% and > 40% reductions from baseline in LDL-cholesterol. Both agents also increased high density lipoprotein-cholesterol and reduced triglycerides. Overall, 65.1% of patients treated with cerivastatin and 63.3% of patients with pravastatin achieved LDL-cholesterol goals defined by the National Cholesterol Education Program. Both drugs were well tolerated, with most adverse events being mild. These results demonstrate that cerivastatin (0.3 mg) is a highly effective 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, which enables a large proportion of patients to achieve clinically meaningful reductions in LDL-cholesterol.

Adolescent↗
PubMed1998

Renin status does not predict the anti-hypertensive response to angiotensin-converting enzyme inhibition in African-Americans. Trandolapril Multicenter Study Group.

The angiotensin-converting enzyme (ACE) inhibitor trandolapril, a non-sulfhydryl prodrug which is hydrolysed into trandolaprilat, was studied in 322 hypertensives of African-American descent using a double-blind, randomised, placebo-controlled, parallel study design. Following 6 weeks of double-blind treatment with placebo or 0.25 to 16 mg/day trandolapril, an analysis of drug effect on trough blood pressure (BP) stratified by age, gender, weight, pre-treatment plasma renin activity, and trandolaprilat concentration was performed. Two mg was the lowest effective trandolapril dose, whereas doses above 4 mg did not significantly reduce trough BP. Reduction in BP did not correlate with trough plasma trandolaprilat concentration. Pre-treatment plasma renin activity was not a reliable indicator of anti-hypertensive response, as similar reductions in BP occurred even in patients with the lowest renin levels. There were no observable differences based on age, gender or measurements of the renin-angiotensin-aldosterone axis. In conclusion, neither age, gender or plasma renin activity influenced anti-hypertensive response to angiotensin-converting enzyme inhibition in African-Americans.

Aged↗
PubMed1997

Strength of core build-up materials in endodontically treated teeth.

PURPOSE: To compare the in vitro strength of a reinforced glass ionomer and a light-cured glass ionomer used as an alternative to amalgam in core construction to restore endodontically treated mandibular molar teeth. MATERIALS AND METHODS: The root canals of 120 extracted human mandibular molar teeth were prepared chemomechanically and obturated with laterally condensed cold gutta-percha. The crown of each tooth was sectioned leaving only one cusp standing. Gutta-percha was removed from the pulp chamber in all teeth. The volume of the pulp chamber was measured and the teeth ranked in ascending order of chamber volume. The specimens were divided into six groups of 20, allocating teeth with similar chamber volumes into each group. In three of the groups, gutta-percha was removed from the coronal 3-4 mm of each root canal. The teeth were restored with one of three materials, a cermet cement (Ketac-Silver), a resin-reinforced glass ionomer (Vitremer), or amalgam (Contour). Core preparation was carried out after 48 hours, reducing each core height to 6 mm. The specimens were thermocycled for 24 hours and then mounted in dental stone. A control group of 20 unrestored human mandibular molars was mounted in cold cure acrylic. Each tooth was tested in a Nene machine with a compressive load applied at 90 degrees to the occlusal surface at a crosshead speed of 5 mm/minute. RESULTS: There was no statistically significant difference between the experimental groups (P > 0.05), but the control group was significantly stronger (P < 0.001). Extension of core material into the coronal root canal system did not increase the fracture resistance of any of the experimental materials. Regression analysis of the results revealed no correlation between the volume of the pulp chamber and the load to fracture.

Cermet Cements↗
PubMed1996

A new antihypertensive strategy for black patients: low-dose multimechanism therapy.

Hypertension poses serious health risks for blacks because this population presents with earlier onset and more severe forms of the disease than do nonblacks. Although diuretics are the cornerstone of antihypertensive therapy In the black population, investigators have expressed concern about adverse metabolic effects, such as hypokalemia, produced by the high doses of diuretics traditionally prescribed for blacks. Recent evidence suggests that black patients may respond equally well to the new generation of cardioselective beta-blockers and angiotensin-converting enzyme inhibitors, particularly when these agents are used together with a diuretic. A new low-dose multimechanism agent that combines the cardioselective beta-blocker bisoprolol fumarate with hydrochlorothiazide, a benzothiazine diuretic, is now available for first-line therapy for hypertension. Results of two US multicenter trials--including a subset analysis of black patients--indicate that the once-daily agent is highly effective in reducing diastolic and systolic blood pressure throughout a 24-hour period in both black and nonblack patients. The agent is well tolerated in blacks and non-blacks and has a side-effect profile comparable to placebo. Because of its efficacy and safety in black patients, bisoprolol fumarate/-hydrochlorothiazide is an appropriate therapeutic option for first-line therapy of hypertension in the black population.

Black or African American↗
PubMed1995

Hypertension in minorities: blacks.

Hypertension is known to occur much more frequently in blacks than in the general population, roughly 33% to 50% more frequently. In addition, severe hypertension occurs 3 to 7 times more commonly in blacks than whites and is associated with an excessive amount of target organ damage. Thus, damage to the heart, kidneys, and cerebral structures may occur as much as three to five times more frequently in blacks than the general population and is associated with a much greater mortality. Because of differences in clinical presentation, delays in entering the medical care system, and some pathophysiologic features specific for the black population, treatment becomes somewhat more challenging and should be tailored for this population. Because of economic factors often found in minority populations, inexpensive effective drugs such as diuretics and beta-blockers, which are preferred drugs according to the JNC-V, often should be given first consideration in this population. However, calcium channel blockers seem to be quite effective in this group, equal to in the white population, although they are somewhat more expensive. Angiotensin converting enzyme inhibitors, if given in proper dosage and especially with low dose diuretics, are also quite effective in this population. Tissue specific angiotensin converting enzyme inhibitors may be more effective, but further studies are needed. Studies have shown that effective treatment of the black population, in spite of the differences and the more challenging situation, can result in improved survival and reduction in morbidity and mortality from the various complications.

Black People↗
PubMed1995

Differing mechanisms of action of angiotensin-converting enzyme inhibition in black and white hypertensive patients. The Trandolapril Multicenter Study Group.

The antihypertensive effect of the angiotensin-converting enzyme inhibitor trandolapril administered in doses of 1, 2, and 4 mg/d was compared in 207 white patients and 91 black patients with mild to moderate hypertension following a double-blind, randomized, placebo-controlled, parallel study design. Trandolapril is a prodrug that is rapidly hydrolyzed to its active diacid metabolite, trandolaprilat. After 6 weeks of double-blind treatment, trandolapril lowered baseline sitting diastolic pressure in both white and black patients. A comparison of the antihypertensive response of the two populations revealed that the black patients required between two and four times the dose of trandolapril to obtain a response similar to that observed in the white patients. A dose of 1 mg/d trandolapril resulted in a 6.1 mm Hg mean decrease in baseline sitting diastolic pressure for white patients; a similar response (-6.5 mm Hg) was observed in the black patients at 4 mg/d. In contrast to the population differences in blood pressure, the decreases in angiotensin-converting enzyme activity were similar for both populations. An evaluation of trandolaprilat levels revealed that there were no racial differences in the trandolaprilat concentrations required to achieve a given degree of angiotensin-converting enzyme inhibition. Therefore, it appears that the antihypertensive response of black patients is not completely explained by a reduction in angiotensin-converting enzyme activity. The lack of response at a lower dose but increasing response at a higher dose could reflect another vasodepressor activity of trandolapril or just be evidence of reduced sensitivity of high blood pressure in blacks to angiotensin-converting enzyme inhibition.

Aldosterone↗
PubMed1992

Effect of dose rate on the survival of irradiated human skin fibroblasts.

The survival of cells in density-inhibited, confluent cultures maintained at 37 degrees C was examined following exposure to 137Cs gamma rays at low dose rates (0.023 or 0.153 Gy/h) or to 60Co gamma rays at a single high dose rate (0.70-0.75 Gy/min). Cells from an ataxia telangiectasia (AT) homozygote showed no dose-rate effect, whereas a three- to fivefold increase in D0 was observed for all other cell strains exposed at low dose rates. The magnitude of the dose-rate effect did not differ significantly among cells from persons with hereditary retinoblastoma, basal cell nevus syndrome, or AT-heterozygote compared with normal cell strains, and was not related to the size of the shoulder (extrapolation number) of the survival curve. Furthermore, no differences in the capacity for the repair of potentially lethal damage during confluent holding were observed among these latter cell strains.

Ataxia Telangiectasia↗
PubMed1991

The safety and efficacy of terazosin in the treatment of essential hypertension in blacks.

Terazosin, a new selective alpha 1-adrenergic receptor antagonist, has been found to be an effective antihypertensive agent. In a series of studies, the safety and efficacy of terazosin, alone and in combination with other antihypertensive agents, were evaluated in 1180 black patients with mild to moderate essential hypertension. Terazosin was effective in lowering blood pressure when administered alone (in dosages of 1 to 80 mg/day) and when prescribed (in dosages of 1 to 20 mg/day) in combination with other antihypertensive agents. In elderly black patients, terazosin, 1 to 10 mg daily, was as effective in lowering blood pressure as propranolol (40 to 120 mg twice daily). Changes (mean +/- SE) in sitting diastolic blood pressure from baseline were -8.1 +/- 1.4 mm Hg for terazosin and -5.0 +/- 1.5 mm Hg for propranolol. Terazosin (5 mg) combined with methyclothiazide (2.5 to 5 mg) produced a significantly greater (p less than 0.01) antihypertensive effect than that of terazosin alone. Changes (mean +/- SE) in standing diastolic blood pressure from baseline were -7.9 +/- 2.0 mm Hg for terazosin alone, -15.1 +/- 2.1 mm Hg for terazosin plus 2.5 mg of methyclothiazide, and -15.0 +/- 2.0 mm Hg for terazosin plus 5 mg of methyclothiazide. Terazosin had a favorable effect on serum lipid levels and appeared to compensate for the negative lipid effects associated with diuretics and beta-blockers when used in combination with these agents. Terazosin, alone and combined with other antihypertensive agents, was well tolerated with minimal side effects in black hypertensive patients.

Adrenergic alpha-Antagonists↗