Biomedical subjects

C W Newman

Publications and source records attributed to C W Newman.

At least 19 recordsLinked to original sources

PubMed1992

Effect of full-fat or defatted rice bran on serum cholesterol.

Rice bran has been shown to lower serum cholesterol in hamsters. Leghorn cockerel chicks were fed 60% full-fat rice bran (FFRB) and corn/soy (CS) diets with 0.5% added cholesterol. Both diets contained 18% protein. All reported parameters are on blood serum. Significant differences (p less than 0.05) were found in total cholesterol (TC), triglycerides (TG), high-density and low-density lipoprotein cholesterol (HDL and LDL). In a second study, chicks were fed FFRB, defatted rice bran (DFRB), and CS diets balanced for 18% protein, 14.47% total dietary fiber and 10.78% lipid with 0.5% added cholesterol. Both TC and TG were significantly lower (p less than 0.05) in chicks fed FFRB and CS diets. Significant differences were found in HDL values for all diets with FFRB exhibiting the highest mean value (155 mg/dl) and CS exhibiting the lowest mean value (114 mg/dl). All diets were significantly different (p less than 0.05) in LDL, with mean values of 249, 318 and 275 mg/dl for FFRB, DFRB and CS, respectively. FFRB appears to increase HDL and to lower LDL in chicks, but does not always affect TC, whereas DFRB may increase all three serum lipid components.

Animals↗

PubMed1992

Barley beta-glucans alter intestinal viscosity and reduce plasma cholesterol concentrations in chicks.

Ninety-six 14-d-old male broiler chicks were divided into three dietary groups and fed a corn-soybean meal diet, a barley diet with beta-glucanase and that diet without beta-glucanase. All diets contained 4 g cholesterol/kg. Average daily body weight gain, plasma total cholesterol concentration, LDL cholesterol concentration and digestibility of lipids and protein were lowest (P < 0.05) in the chicks fed the barley diet without beta-glucanase and highest (P < 0.05) in the chicks fed corn-soybean meal diet. Supplementation of the barley diet with beta-glucanase resulted in greater (P < 0.05) average daily weight gain, plasma total and LDL cholesterol concentrations and digestibility of lipids. Viscosity of small intestinal digesta was greatest in chicks fed barley, lowest in those fed the corn-soybean diet and intermediate in chicks fed enzyme-treated barley. Significant (P < 0.01) negative correlations occurred between viscosity of the small intestinal contents and average daily weight gain, plasma total and LDL cholesterol concentrations, and digestibility of lipids and protein. A lower concentration of insoluble beta-glucans in small intestinal digesta of the chicks fed barley supplemented with beta-glucanase compared with the chicks fed the unsupplemented barley diet reflects hydrolytic activity of the supplemental beta-glucanase in the diet.

Animal Feed↗

PubMed1992

Barley diets with different fat sources have hypocholesterolemic effects in chicks.

Saturated fat is known to elevate serum cholesterol, whereas soluble dietary fiber has a hypocholesterolemic effect. The objective of this study was to compare the effects of barley and wheat diets supplemented with five fat sources on lipid metabolism in chicks. In two separate experiments, broiler chicks were fed isonitrogenous diets containing 23% protein, 11.4% dietary fiber and 10% dietary fat for 17 d. Diets contained 60% either hull-less barley or red spring wheat, with either palm oil, dehydrated egg yolk, butter, tallow or corn oil. Growth, feed efficiency, plasma lipids, liver cholesterol, and fecal fat and dry matter were measured. All chicks fed wheat grew faster and had greater food efficiency than those fed barley. All barley-fed chicks had lower (P less than 0.0001) total plasma cholesterol concentration (3.1 to 4.0 mmol/L) than those fed wheat (6.0 to 11.3 mmol/L). Chicks fed palm oil with wheat had the highest total cholesterol, 11.3 mmol/L. Liver cholesterol concentration was higher (P less than 0.0001) for all wheat-fed chicks (22.8-86.4 mmol/g) compared with those fed barley (6.7 to 12.2 mmol/g). Fecal crude fat was higher (P less than 0.05) for chicks fed barley, and excreta dry matter was lower for barley-fed chicks. Results indicate that the high soluble fiber content of this barley exerts a hypocholesterolemic effect in chicks regardless of dietary fat source, possibly mediated through lowered fat absorption.

Animals↗

PubMed1992

The effects of stimulus frequency and recording site on the amplitude and latency of multichannel cortical auditory evoked potential (CAEP) component N1.

Magnetoencephalographic (MEG) applications in auditory evoked field (AEF) recordings have demonstrated that both tonotopicity and amplitopicity exist in the auditory cortex. The present study was conducted to determine whether previously reported characteristics of the AEF could be identified in multichannel cortical auditory evoked potential N1e (e.g., the electrical correlate of the magnetically recorded N1m) component recordings. Multichannel auditory evoked potentials from 11 young normal adults were collected after monaural tone burst stimuli of 250, 1000, and 4000 Hz. Results demonstrated that N1e amplitudes after stimulation at 250 Hz were significantly larger than those obtained after stimulation at 1000 or 4000 Hz. These frequency-specific differences existed for latency as well. Responses obtained after stimulation at 250 Hz were, on the average, 13 msec longer than those obtained after stimulation at 1000 or 4000 Hz. Also, contralateral latencies were significantly shorter than ipsilateral latencies. Although the significant frequency-specific amplitude results support the findings of previous investigators, the frequency-related latency differences have not been described. An explanation of these differences may exist in the spatial differences in the reception areas for low- and high-frequency tones in the primary auditory cortex.

Acoustic Stimulation↗

PubMed1992

Occurrence of auditory evoked field (AEF) N1M and P2M components in a sample of normal subjects.

A great deal of information about the characteristics of components N1m and P2m of the auditory evoked cortical fields (AEFs) has accumulated since the late 1970s. However, a number of fundamental issues have not been addressed. For instance, some previous investigators have suggested that P2m is present consistently in normals, whereas others suggest that when present, P2m is small in amplitude. Preliminary observations in this laboratory suggested that P2m is not observed consistently in normal subjects. Therefore, the specific aim of this investigation was to estimate the frequency of occurrence of the contralaterally recorded N1m and P2m after stimulation of right and left ears in normal subjects. Results demonstrated N1m to be present in all circumstances. Consistent with our preliminary observations, P2m was often absent, and moreso after stimulation of the left ear.

Adult↗

PubMed1991

Growth and lipid metabolism as affected by feeding of hull-less barleys with and without supplemental beta-glucanase.

Three hull-less barleys, Washonupana (WSNP), Waxbar (WXB), and Bangsa (BGS), were fed to broiler chicks in 21% protein diets containing 0.5% cholesterol in replicate trials. A corn-based diet, with added cholesterol, served as a control. Alternate diets were supplemented with beta-glucanase (ENZ). beta-glucan content ranged from 4.9% to 6.1% and soluble dietary fiber (SDF) from 3.6% to 7.5% in the barleys. Data from the two trials were pooled for statistical analysis by the SAS General Linear Models procedure. In body weight gain, chicks fed WSNP-ENZ were lower (P less than 0.05) than all other treatments. The beta-glucanase supplement to the WXB and BGS barley tended to improve gains, but the differences were not significant for either barley. Feed to gain ratios were lowest (P less than 0.0001) for corn fed chicks and lower (P less than 0.05 to P less than 0.0001) for those fed the barley + ENZ diets compared to barley -ENZ. Chicks fed barley diets had lower (P less than 0.05) total serum cholesterol (TSC) and LDL-cholesterol than those fed corn diets, regardless of ENZ supplementation. For chicks on barley -ENZ diets, TSC levels for WSNP, WXB, and BGS were 146, 152, and 142 mg/dl respectively and for chicks on barley + ENZ diets, 218, 200, and 178 mg/dl. LDL-cholesterol levels followed the same trend and there was little difference in serum triglycerides. The BGS + ENZ lowered TSC 30% from the corn control compared to 10.7% and 18% for WSNP + ENZ and WXB + ENZ, suggesting additional hypocholesterolemic factors, possibly tocotrienol and SDF other than 1----3, 1----4 beta-D-glucans.

Animals↗

PubMed1991

Auditory evoked cortical magnetic field (M100-M200) measurements in tinnitus and normal groups.

Recently, Hoke et al. (1989) and Pantev et al. (1989) demonstrated that the auditory evoked cortical magnetic field (AECMF) M100 component was larger, and M200 was smaller and occurred later in subjects with unilateral tinnitus compared with normal subjects. These group amplitude differences resulted in an M200/M100 amplitude ratio that was smaller for the subjects with tinnitus. The purposes of the present investigation were to: 1) extend the observations of Hoke et al. (1989), and, 2) determine whether contralateral AECMF differences existed following stimulation of the non-tinnitus and tinnitus ears of patients with tinnitus. Neuromagnetic AECMF recordings were recorded from 25 young normal hearing and 14 patients with unilateral tinnitus and hearing loss. The results failed to support the findings of Hoke et al. (1989). Specifically, there is no evidence suggesting that the M100 amplitude is larger, the M200 latency later, or, the M200/M100 amplitude ratios smaller, when the two samples are compared. Additionally, there were no differences in the amplitudes or latencies of M100 or M200 when results from stimulation of the tinnitus and non-tinnitus ears of tinnitus subjects were compared.

Adult↗

PubMed1991

The effects of rate, sequencing, and memory on auditory processing in the elderly.

Auditory sequencing, rate, and memory were evaluated in three age groups with a series of subtests that require the identification of tones (Repetition Test; Tallal & Piercy, 1973). The older elderly group (M age = 80), but not the younger elderly group (M age = 70), performed significantly (p less than .05) poorer than the young adult group (M age = 25) when auditory memory of 4 and 5 tones was required and when the interstimulus interval was decreased. Performance was not related to hearing sensitivity, thus suggesting that changes in the auditory mechanism that occur with age may encompass more than a loss of hearing sensitivity. Moreover, performance on the Repetition Test did correlate with memory for digits, which indicates a relationship between auditory processing and higher cortical functions.

Acoustic Stimulation↗

PubMed1991

Test-retest reliability of the hearing handicap inventory for adults.

The test-retest reliability of the Hearing Handicap Inventory for Adults (HHIA) was assessed on a sample of 28 hearing-impaired adults. Reliability estimates were obtained to set the stage for using the HHIA as an outcome measure in aural rehabilitation. The test-retest reliability was quite high (r = 0.97) and the standard error of measurement was low for the HHIA and its screening version (HHIA-S). In light of the psychometric adequacy, the HHIA and HHIA-S have potential as indices of hearing aid benefit in hearing-impaired adults.

Adult↗

PubMed1991

Probe-tube measurements of ALDs: uniformity, linearity and frequency response differences.

A Madsen IGO 1000 was used to assess six assistive listening devices (ALDs) (Sound Plus Infrared, Minicon Induction Floor Loop, Phonic Ear Phonear, Radio Shack Realistic Personal Amplifier, Williams Sound PockeTalker with induction neck loop and Williams Sound PockeTalker permanently wired) worn by a single subject. In situ measures determined product uniformity of three samples of each of the same ALDs, volume control linearity, ear coupling effects on canal resonance and frequency response differences. ALDs were generally uniform, although the two PockeTalker models showed gain variability at all frequencies. Frequency response changes controlled by high boost switches in the Realistic were also found not to be uniform. The earbud had almost no effect on canal resonance, while lightweight headphones caused a slight loss of canal resonance. Non-telecoil coupled devices had broader/flatter responses than telecoil coupled devices. Average differences between telecoil and non-telecoil coupling were minimal. Probe-tube measurements were found to be a feasible means of assessing ALDs in situ.

Acoustic Impedance Tests↗

PubMed1991

Differences in superficial and deep source contributions to middle latency auditory evoked potential Pa component in normal subjects and patients with neurologic disease.

Multichannel brain-mapped middle latency auditory evoked potential (MLAEP) data obtained from 15 normal subjects and three neurologically impaired subjects using the common average reference (CAR) were converted off-line to source current density (SCD). This technique is sensitive to activity generated in the superficial cerebral cortex. The SCD maps were subtracted from the CAR maps (CAR-SD). The derived CAR-SD maps are believed to represent the proportion of scalp-recorded activity that is generated deep to the cerebral cortex. Topographic analysis of this data manipulation technique supports the hypothesis that Pa originated from within the temporal lobes bilaterally as well as from a deeper subcortical system.

Adult↗

PubMed1991

Practical method for quantifying hearing aid benefit in older adults.

Self-assessment handicap scales are gaining recognition as objective measures of audiologic intervention, including benefit derived from hearing aid use. A short form of the Hearing Handicap Inventory for the Elderly (HHIE-S) comprised of 10 items (5 emotional and 5 social/situational) was administered to 91 new hearing aid users prior to and 3 weeks following hearing aid provision. A significant reduction in perceived emotional and social/situational effects of hearing impairment was observed following this brief interval of hearing aid use. The magnitude of hearing aid benefit was not affected by pure-tone sensitivity or word recognition ability. Further, a 95 percent confidence interval was established for the HHIE-S (9.3 points) in order to determine a true change in self-perceived handicap and pre- and post-hearing aid fitting for a given subject. Our findings support the use of the HHIE-S as an expedient approach for quantifying hearing aid benefit in a busy clinical practice.

Aged↗

PubMed1991

Balance function test correlates of the Dizziness Handicap Inventory.

Balance Function test data alone cannot capture the reaction that a patient has to balance system disease. The present investigation examined the relations among components of the balance function examination (electronystagmography, rotational testing, and platform posturography) and self-perceived dizziness handicap, as quantified by the Dizziness Handicap Inventory (DHI). The DHI is a 25-item self-assessment scale designed to quantify the functional, emotional, and physical effects of dizziness and unsteadiness. The DHI was administered to 367 patients seen consecutively for balance function evaluations. The results indicated that the largest proportion of significant correlations existed between DHI and the sensory organization subtests of platform posturography. Further, greater perceived handicap was documented for patients with (1) spontaneous nystagmus and (2) decreased postural stability quantified by evaluating the inter-relations among vestibular, visual, and proprioceptive systems (posturography).

Activities of Daily Living↗

PubMed1990

The development of the Dizziness Handicap Inventory.

Conventional vestibulometric techniques are inadequate for quantifying the impact of dizziness on everyday life. The 25-item Dizziness Handicap Inventory (DHI) was developed to evaluate the self-perceived handicapping effects imposed by vestibular system disease. The development of the preliminary (37 items) and final versions (25 items) of the DHI are described. The items were subgrouped into three content domains representing functional, emotional, and physical aspects of dizziness and unsteadiness. Cronbach's alpha coefficient was employed to measure reliability based on consistency of the preliminary version. The final version of the DHI was administered to 106 consecutive patients and demonstrated good internal consistency reliability. With the exception of the physical subscale, the mean values for DHI scale scores increased significantly with increases in the frequency of dizziness episodes. Test-retest reliability was high.

Activities of Daily Living↗

PubMed1990

The decomposition of the middle latency auditory evoked potential (MLAEP) Pa component into superficial and deep source contributions.

The results of recent investigations have suggested that the Middle Latency Auditory Evoked Potential (MLAEP) Pa component derives its physiological origins from both cortical and subcortical sources. The purpose of the present investigation was to determine if support for this hypothesis could be obtained from the off-line manipulation of the topographically recorded Pa component. The multichannel MLAEP from 15 normal hearing, neurologically intact subjects was collected following monaural left and right ear click stimulation. Data was originally collected using the linked ear reference and was subsequently re-referenced using the common average reference (CAR). These mapped data were converted off-line to source current density using the source derivation (SD) technique described by Hjorth (1975, 1980). This technique is sensitive to current activity that is generated in the superficial cerebral cortex. These SD maps of the MLAEP were subsequently subtracted from the CAR maps of the MLAEP. The derived CAR-SD maps are believed to represent that activity that is generated deep to the cerebral cortex (Hjorth and Rodin 1988). Interpretation of the mapped data have demonstrated support for the hypothesis that Pa is generated by a minimum of two systems including: 1) bilateral sources located in the posterior temporal lobes, and 2) a deeper midline generator system.

Acoustic Stimulation↗

PubMed1990

The Hearing Handicap Inventory for Adults: psychometric adequacy and audiometric correlates.

The Hearing Handicap Inventory for the Elderly (HHIE) was modified for use with younger hearing-impaired adults (less than 65 years of age). Similar to the HHIE, the Hearing Handicap Inventory for Adults (HHIA), is a 25-item self-assessment scale composed of two subscales (emotional and social/situational). Replacement questions from the HHIE which form the HHIA focus on the occupational effects of hearing loss. For 67 hearing-impaired adults, the HHIA demonstrated high internal consistency reliability and a low standard error of measurement. Audiometric correlates of the HHIA revealed weak, yet statistically significant relationships with pure-tone sensitivity and supra-threshold word recognition ability. These findings support the use of self-report handicap measures with adults in that audiometric measures alone are insufficient in describing a patient's reaction to their hearing loss.

Adolescent↗

PubMed1990

Sensitivity and specificity of the head-shaking test for detecting vestibular system abnormalities.

The head-shaking nystagmus (HSN) test has been reported to be a sensitive screening test for the presence of peripheral and central vestibular system disease. Previous investigations have utilized few subjects who were drawn from well-defined patient populations. The purpose of the present investigation was twofold: first, to determine the prevalence of HSN in a large unselected population of dizzy patients seen in an otology and neurotology practice, and second, to determine the sensitivity and specificity of this evaluation in the detection of vestibular system abnormalities as reflected by results of electronystagmography and rotary chair testing. The results of the investigation have suggested that the HSN test has a 27% sensitivity and an 85% specificity. The HSN test yields an acceptable number of false positives (15%) and an unacceptably large number of false negatives (73%).

Dizziness↗

PubMed1990

Infant hearing screening 1984 to 1989: the Henry Ford Hospital experience.

From 1984 to 1989 the Infant Hearing Screening (IHS) program at Henry Ford Hospital identified 1,300 infants as being "at risk" for hearing loss. The prevalence of significant sensorineural hearing loss in this sample was 1.4%. Additionally, 80 infants who passed the IHS program and reached 3 years of age were found to have normal hearing sensitivity by conventional audiometric techniques (ie, no false-negative predictions). There were three false-positive predictions. It was discovered that infants of low birthweight (ie, less than 1,500 g) were three times more likely to fail IHS than those whose weight exceeded 1,500 g. A higher return rate was found for infants failing an initial hearing screening conducted in the neonatal intensive care unit in comparison to those screened as outpatients one week postdischarge. The sensitivity and specificity of behavioral observation audiometry were 43% and 92%, respectively, when brainstem auditory-evoked potentials was used as the criterion validity measure.

Audiology↗