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Biomedical subjects

E Perrin

Publications and source records attributed to E Perrin.

At least 37 records · Page 2Linked to original sources
PubMed1997

Acoustical recognition of laryngeal pathology using the fundamental frequency and the first three formants of vowels.

The recognition of laryngeal pathology by analysis of the voice is investigated. The fundamental frequency and the first three formants are considered. The recognition strategy is based on comparison with normal ranges calculated over 200 ordinary voices, grouped in ten age classes ranging from 20 to 70 years, for males and females. 220 test voices are studied divided into four groups: normal voices, functional dysphonia, nodules and recurrent nerve palsy. Each subject is marked according to his/her normal range. Parameters (or items) are calculated on the Interactive Laboratory System workstation. The vocalic material is composed of 11 vowels taken from a sentence. Results are given in terms of the number of values out of the normal ranges. Statistical analysis considers both parameter ability and error rates in pathology recognition. Pathology recognition shows the following error percentages: 23% for dysphonia, 14% for nodules and 33% for recurrent nerve palsy. Parameters do not show the same efficiency for voice pathology characterisation. Formants appear to be better than the fundamental frequency.

Adult↗
PubMed1996

Development of cochlear active mechanisms in humans differs between gender.

Despite onset of function early during the third term of gestation, the human auditory system demonstrates continued maturation, thought previously to occur primarily at the neural level. The electromotile properties of outer hair cells appear to contribute substantially to hearing sensitivity and frequency selectivity and lead to the generation of otoacoustic emissions (OAEs). This report demonstrates continued development of cochlear active mechanisms (i.e. end-organ level) after onset of cochlear function, as reflected by OAEs. Significant gender differences also are reported, corresponding to recently observed intersex differences in cochlear length and precursory to gender differences observed in the adult.

Cochlea↗
PubMed1996

Contralateral acoustic stimulation induces a phase advance in evoked otoacoustic emissions in humans.

In 28 normal-hearing human subjects, the medial olivocochlear efferent system was activated by contralateral acoustic stimulation which is able to mimic the inhibitory effects of electrical stimulation of the crossed olivocochlear bundle. A first experiment on 16 subjects demonstrated that a contralateral white noise of 35 dB SL was able to induce temporal changes on transiently evoked otoacoustic emissions in response to clicks of 63 dB SPL. These temporal changes consisted of an advance of click-evoked otoacoustic signals in 87% of cases and is referred to as phase-shift effect. The phase advance, quantified using two signal processing methods in both time and frequency domains, was found to be mainly associated with lower frequencies, with a maximal effect at 1.5 kHz and minimal effects around 3.5 and 4 kHz. In a second experiment, carried out on 12 subjects, a negative relationship was found to exist between the ipsilateral stimulation level (level of clicks ranging from 57 to 69 dB SPL) and the phase-shift effect (PSE). Specifically in the range of levels tested (25-45 dB SL), a linear relationship presenting no obvious saturation effect was observed between the contralateral level and the PSE. The PSE was examined in 6 additional subjects exhibiting pathological symptoms; 2 of 3 individuals, who had no contralateral stapedial reflexes unilaterally, showed the PSE whereas this response was reduced or absent in 3 other subjects in the ear with severed efferents associated with a vestibular neurotomy. The integrity of olivocochlear efferents was, therefore, necessary to obtain a full effect, but the absence of stapedial reflex did not prevent the effect from occurring.

Acoustic Stimulation↗
PubMed1996

Physician compensation models in medical group practice.

This article examines physician compensation models in medical groups and the factors affecting physician compensation and their impact on individual physician behavior and group practice performance. Four categories of physician compensation models are identified: (1) production-based compensation, (2) salary, (3) group-based compensation unrelated to individual physician productivity, and (4) capitation-based compensation. The statistics and the economic incentives of different compensation methods are presented. Finally, the impacts on health resources consumption, charges in medical group procedures for utilization and care management, and quality of care are discussed.

Economic Competition↗
PubMed1996

Cholesterol levels among Japanese Americans and other populations: Seattle Nikkei Health Study.

The purpose of this study was to compare average cholesterol levels between Seattle based Japanese Americans and three other populations: U.S. population, native Japanese population and native Japanese urban workers. A total of 1,466 Japanese Americans (724 men and 742 women) participated in cardiovascular disease screening in the Seattle area during 1989 94. Data sources for comparisons are from the Third National Health and Nutrition Examination Survey for 1988-91, the results of the National Cardiovascular Disease Examination Survey in Japan for 1990, and cardiovascular disease screening conducted by the Epidemiological Arteriosclerosis Research Institute in Japan for 1989. Total cholesterol and triglyceride levels of Seattle Japanese American men and women were highest among the four populations. Among men, high density lipoprotein cholesterol (HDL-C) levels for Seattle Japanese Americans and native Japanese were similar and fell between those of urban Japanese workers and the U.S. population. In women, the average HDL C levels were highest in the Japanese urban workers, second highest in Seattle Japanese Americans, and lowest in both the U.S. population and native Japanese population. These differences in lipid levels may be caused by both genetic and environmental factors, which are now under investigation.

Adult↗
PubMed1996

The role of congruence between patient and therapist in chronic low back pain patients.

OBJECTIVE: To determine the role of congruence in the perception of the evolution of back pain during treatment and in the expectations about the future of back pain problems. Congruence was defined as the agreement between patient and therapist on various aspects of back pain problems and of treatment. DESIGN: Semistructured interviews at the beginning and the end of treatment. SUBJECTS: Seventy-one back pain patients and their therapists (6 chiropractors and 6 rheumatologists). MAIN OUTCOME MEASURES: Synthesized index of congruence based on 24 questions asked of both the patient and his/her therapist. RESULTS: The distribution of the congruence scores indicated a high level of congruence in 39.4% of the cases, an average level in 35.2% and a low level in 25.4%. The results demonstrated that congruence was significantly associated with the perception of an improvement in back pain. This positive perception was nevertheless associated with the expectation of persistence or recurrence of the back pain problem in the future. Noncongruence was correlated with the patient's estimation of a less favorable evolution of the back pain problem during the treatment and with a major difficulty for both the therapist and the patient to express clear expectations about the future of the patient's back pain problem. CONCLUSIONS: Congruence mainly reflects an agreement that the treatment is aimed at the management of a long-term condition rather than at the resolution of the back pain problem. Congruent patients seem to accept living with their back problems, a position shared by their therapists, whereas noncongruent patients do not seem to share this conception of back pain.

Adult↗
PubMed1995

Rapid determination of the ratios of three aromatic residues in peptides by reversed-phase high-performance liquid chromatography with a high-resolution photodiode-array detector.

A method for the simultaneous determination of the ratios of three aromatic residues in peptides by derivative UV spectrophotometry on a spectrophotometer with a resolution of 0.1 nm can be used for the RP-HPLC analysis of peptides because of the recent development of high-resolution photodiode-array detectors (1.2 nm). The difference between the theoretical and experimental ratios of aromatic residues of peptides determined in real time is less than 5%. This method could become a powerful tool for the study of peptides and hydrolysates: A variety of possible applications are discussed.

Amino Acid Sequence↗
PubMed1995

Determination of the ratios of the aromatic amino acid residues by first- or second-derivative UV spectrometry for a simple characterization of peptides.

A method for the simultaneous determination of the ratios of the three aromatic amino-acid residues in peptides was set up in acidic conditions. Binary and ternary mixtures of these amino acids were prepared, and first- and second-derivative spectra then calculated from their 0.1 nm resolution spectra between 240 and 320 nm. Certain spectral bands were chosen to differentiate tyrosine from tryptophan on the first-derivative spectra, and phenylalanine from tyrosine and tryptophan on the second-derivative spectra. Variation of the amplitude of the chosen bands was shown to be a linear function of the ratio of the aromatic amino acids in the mixture. This technique was validated with peptides whose sequence was known. The difference between theoretical and experimentally determined ratios was lower than 10%. Since the results are obtained as ratios, neither the concentration nor the nature of the peptide has to be known. The feasibility of application using a photodiode array detector with high resolution in reversed-phase high-performance liquid chromatography is discussed.

Amino Acid Sequence↗
PubMed1995

[Acoustic characterization of velar insufficiency in young children].

The following study concerns the acoustic parameters marking the difference between the phonation of children with velar incompetency and a corresponding control group. Population is made of 64 children aged 5 and 6; 32 are in the control group and 32 in the pathological group. Each child was required to repeat several words; 10 vowels and 9 consonants were taken from those words. Acoustic signal was recorded and studied using a standard speech assessment work station. 63 parameters for the vowels and 6 for the consonants were studied. Results showed that the best parameters concerned the vowels and that cepstrum coefficients were an efficient tool to perform the separation of the two groups. On the contrary, formants, voice pitch and jitter did not appear to be efficient enough to do this task. It was, then, deduced a check form for velopharyngeal incompetency, form which will be tested in future work.

Case-Control Studies↗
PubMed1994

Acute ammonium dichromate poisoning.

We report the ingestion of ammonium dichromate by a child that resulted in multiple-organ-system failure and death. Exchange transfusion and hemodialysis were ineffective in removing significant amounts of chromium or causing sustained clinical improvement. We suggest that immediate, large doses of the reducing agent ascorbic acid would allow effective reduction of hexavalent chromium with less cellular toxicity.

Chromates↗
PubMed1991

Effect of growth factors on collagen metabolism in cultured human heart fibroblasts.

Using human heart fibroblasts (HHF), we studied the effect of basic fibroblast growth factor (bFGF) and transforming growth factor-beta (TGF-beta) on the gene expression of type I collagen, collagenase and tissue inhibitor of metalloproteinases (TIMP). Initially, treatment of HHF with bFGF alone (10 ng/ml) resulted in elevated secretion of collagenase into the culture medium. Subsequent treatment of HHF with TGF-beta in combination with bFGF suppressed collagenase secretion. Northern blot analysis reinforced this observation by revealing an enhancement of the steady-state mRNA level of collagenase in response to bFGF. In order to examine if the collagenase gene was affected by bFGF at the transcriptional level, transfection experiments were carried out with a plasmid containing collagenase promoter linked to chloramphenicol acetyltransferase gene (CAT). Basic FGF stimulated CAT activity by four-fold, indicating increased promoter activity whereas the combination of TGF-beta and bFGF resulted in decreased CAT activity. TGF-beta was shown to increase type I collagen and TIMP mRNA levels by 2.5- and 2.1-fold, respectively. These results suggest that TGF-beta and bFGF may play a pivotal role in regulating collagen metabolism in HHF.

Cells, Cultured↗
PubMed1990

Prenatal diagnosis of and midtrimester pathology with karyotype 46,XY,del(4)(q22q26). A case report.

A prenatal diagnosis of an interstitial deletion with chromosome 4,46,XY,del(4)(q22q26) was obtained on amniotic fluid cells drawn at 19 weeks' gestation from a 35-year-old gravida. Counseling on the basis of unusual or tenuous data is always difficult, but comparisons with similar deletions in 4q suggested a substantial risk of anomalies. A comparison of the postabortal autopsy findings with those from other reported cases of interstitial deletions of chromosome 4q suggested different pathology with this area of deletion than previously reported for other areas of 4q.

Abnormalities, Multiple↗
PubMed1989

The Medical Outcomes Study. An application of methods for monitoring the results of medical care.

The Medical Outcomes Study was designed to (1) determine whether variations in patient outcomes are explained by differences in system of care, clinician specialty, and clinicians' technical and interpersonal styles and (2) develop more practical tools for the routine monitoring of patient outcomes in medical practice. Outcomes included clinical end points; physical, social, and role functioning in everyday living; patients' perceptions of their general health and well-being; and satisfaction with treatment. Populations of clinicians (n = 523) were randomly sampled from different health care settings in Boston, Mass; Chicago, Ill; and Los Angeles, Calif. In the cross-sectional study, adult patients (n = 22,462) evaluated their health status and treatment. A sample of these patients (n = 2349) with diabetes, hypertension, coronary heart disease, and/or depression were selected for the longitudinal study. Their hospitalizations and other treatments were monitored and they periodically reported outcomes of care. At the beginning and end of the longitudinal study, Medical Outcomes Study staff performed physical examinations and laboratory tests. Results will be reported serially, primarily in The Journal.

Adult↗
PubMed1987

Fetal hemorrhage from umbilical cord hemangioma.

Hemangiomas of the umbilical cord are rare. In this case, an acute, massive fetal hemorrhage from a ruptured umbilical hemangioma occurred after spontaneous rupture of membranes. Ectopic small intestinal mucosa covered the proximal surface of the umbilical cord. Fetal anomalies included a patent vitellointestinal duct remnant and distal ileal atresia. Fetal hemorrhage appears to be another previously unreported and potentially life-threatening complication of umbilical hemangiomas.

Adult↗