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Biomedical subjects

C Laroche

Publications and source records attributed to C Laroche.

At least 19 recordsLinked to original sources
PubMed1992

Frequency selectivity in workers with noise-induced hearing loss.

This study was undertaken in order to document, in a group of subjects affected by a noise-induced hearing loss, the relation between the loss of auditory sensitivity and the loss of frequency selectivity at mid-frequencies, namely 1000 and 3000 Hz. Auditory filter shapes were estimated using the notched noise method. Twelve notch widths were tested, six symmetrical and six asymmetrical with respect to the signal frequency; the spectral level of the noise was set at 50 dB SPL. Data were collected with 22 noise-exposed workers having different degrees of hearing loss. The findings indicate that above a certain degree of hearing loss, which seems to be around 30 dB HL, frequency selectivity tends to decrease linearly with increase in loss of sensitivity. Even when the degree of hearing loss is similar in origin and in magnitude, there is a wide variation among subjects in auditory filter bandwidth. Based on the data collected in this study, it is not possible to adequately predict the auditory filter bandwidth of an individual from hearing threshold levels.

Acoustic Stimulation↗
PubMed1991

Bedside assessment of phrenic nerve function in infants and children.

Phrenic nerve damage is widely recognized after cardiac operations and is associated with an increased morbidity and mortality. Retrospective studies in children have estimated a prevalence of phrenic damage of between 0.5% and 2.2%, but all these studies have limited their investigations to patients who have clinical problems postoperatively, and they have all used clinical or radiologic methods to diagnose the damage. These methods are indirect and hard to evaluate, making the accurate early diagnosis of phrenic nerve damage very difficult. Measurement of phrenic nerve conduction time (phrenic latency) allows direct evaluation of phrenic function and integrity, making it potentially much more specific than indirect methods. Using a simplified method of direct phrenic nerve stimulation, we have developed a method of measuring phrenic latency at the bedside in infants and children. A 1 Hz electrical stimulus is applied over the phrenic nerve in the neck and a diaphragmatic electromyogram from the seventh and eighth intercostal spaces is displayed on a storage oscilloscope. Phrenic latency can be measured directly from the screen. Using these methods we have now studied 37 children (aged 2 days to 15 years) before and after cardiac operations. Mean phrenic latency was 5.4 +/- 1.0 msec on the right and 5.4 +/- 1.0 msec on the left. Prolongation of phrenic latency by more than 2 msec was found in seven of 66 postoperative measurements (10.6%). These patients had a substantially worse postoperative course. We believe this technique to be an important contribution to the diagnosis of postoperative phrenic nerve damage, and one that can help in clinical practice to elucidate an important cause of postoperative morbidity and mortality.

Adolescent↗
PubMed1990

Unsuspected myasthenia gravis presenting as respiratory failure.

A patient developed respiratory failure after surgical removal of a recurrent thymoma, which necessitated removal of part of the diaphragm. The respiratory failure was due to previously undiagnosed myasthenia gravis, which had selectively affected the respiratory muscles.

Azathioprine↗
PubMed1990

Tracheobronchial clearance in patients with bilateral diaphragmatic weakness.

Tracheobronchial clearance was measured in seven patients with bilateral diaphragmatic weakness using a noninvasive objective radioaerosol technique. The data were compared with those from seven healthy nonsmoking control subjects matched for physical characteristics and studied under the same experimental conditions; the control subjects were drawn from a data bank of healthy subjects and were matched to the patients for age, sex, and the initial distribution of their radioaerosol deposition. Pulmonary function indices (FEV1, FVC, PEFR, and MMFR25-75) for the patients were all significantly (p less than 0.01) reduced compared with those for the control subjects. The initial topographic distribution of the radioaerosol within the lungs of the patients and control groups was similar: alveolar deposition [mean (SD)] was 36.4 (6.7) versus 41.0 (4.0)%, and penetration index was 0.56 (0.08) versus 0.56 (0.03), respectively. Tracheobronchial clearance of deposited radioaerosol over a 6-h observation period after inhalation showed a marked reduction (p less than 0.02) in the patients: area under the clearance curve (between zero and 6 h) was 262 (80)% h for the patients and 142 (41)% h for the healthy control subjects. These data suggest that in patients with bilateral diaphragmatic weakness, mucociliary clearance is depressed, or that reduced mechanical movement of the lungs can itself impair clearance of secretions from the lungs. Impaired clearance from either cause may contribute to an increased incidence of chest infections in severe respiratory muscle weakness.

Adult↗
PubMed1989

The growth of and recovery from TTS in human subjects exposed to impact noise.

It is now recognized that temporary threshold shift (TTS) grows to an asymptotic level (ATS) after a prolonged exposure to steady-state and intermittent noise. Few studies have been conducted to verify this process of acquisition for impact noise. However, results obtained on animals have demonstrated that an asymptote is reached after 1-2 h of exposure. These results have been confirmed in the present study on four human subjects using a 470-ms (B duration) impact noise at a rate of 1 pps. The above pattern of acquisition has been retested on two subjects exposed to the same impact for periods of 15-150 min. An ATS of 15-20 dB was measured (Lp = 102-104 dBA) after 30-60 min of exposure. Recovery curves were determined for each exposure duration. They appeared to follow a logarithmic function of post-exposure time. It took from 30-50 min for one subject and from 4-5 h for the other to completely recover. The time for total recovery did not seem to vary as a function of exposure time. Implications are drawn for damage risk criteria and for the study of the effects of impact noise on hearing.

Auditory Fatigue↗
PubMed1988

Psychological aspects of ultrasound imaging during pregnancy.

The psychological impact of ultrasound examination on expectant parents is assessed through direct observation, interviews and the administration of a questionnaire to a large group of parents. The examination was a positive and reassuring experience for most parents. Among a wide array of variables that could account for the effects of the exam, the results were the most important. Women viewing their first ultrasound, specially primiparae were more moved. The results did not confirm that there is a traumatic effect when viewing precedes quickening. Contrary to previous reports, fathers were as emotionally involved as the mothers. The presence of the father seemed also to have a beneficial effect on the mother. One-half of parents wanted to know the sex of the fetus before birth. These findings are discussed, along with implications for problems arising from introduction of new technologies during pregnancy.

Adult↗
PubMed1987

Children of parents with manic-depressive illness: a follow-up study.

Thirty-seven offspring from 21 families with a manic-depressive parent were studied 3 to 7 years following initial evaluation. The study examined both pedigree information and psychosocial variables including parental, marital and overall adjustment, measures of chronicity and severity of parental illness and family assessment measures in relationship to offspring functioning. Nine of the 37 offspring (24%) received a positive DSM-III diagnosis, which is a similar percentage of positive diagnosis of children as we found previously. The diagnoses clustered in the affective illness spectrum. When the presence of affective traits was considered, there was evidence for continuity of psychopathology in most cases. Associations between offspring psychopathology and both non-specific and specific parental risk factors are discussed.

Adolescent↗
PubMed1986

[2 cases of AIDS in patients with hemophilia A].

The authors report the first two cases of lethal AIDS in haemophilia A in France. One French case of AIDS in haemophilia B has already been reported. The diagnosis was based on the observation of opportunist infections associated with severe depression of cell-mediated immunity in both cases. The possibility of active transmission of the LAV retrovirus by factor VII concentrate is discussed. This raises the problem of the signification of anti-LAV antibodies in haemophiliac patients and the control of products used for the treatment of haemophilia.

Acquired Immunodeficiency Syndrome↗
PubMed1986

[Septic arthritis caused by Campylobacter fetus].

The ten published cases of septic arthritis due to Campylobacter fetus and two more recent cases, one of which was a delayed septic complication of a total hip replacement, are discussed. In 83% of cases, febrile monoarthritis occurred which in 7 out of the 12 cases involved an already diseased joint in a subject over 70 years of age (half of the patients), who was frequently alcoholic and presented either cancer or hepatic cirrhosis and/or diabetes. Hyperleukocytosis of the blood was variable (55% of cases). The joint fluid, which contained a high level of deteriorated polynuclear cells, was routinely cultured on an enriched medium in an anaerobic or microerophilic atmosphere and in 10 out of 12 cases Campylobacter fetus was isolated within 15 days, even in the absence of previous antibiotic therapy. The arthritis, which showed little sign radiographically of destructiveness, was cured, leaving no sequellae in most cases. Treatment usually involved ampicillin or the tetracyclines, either alone or in association with the aminoglycosides.

Aged↗
PubMed1985

[Septicemia in cirrhotic patients].

The clinical features of 22 patients with cirrhosis of the liver complicated by septicaemia were studied retrospectively and compared with a control group of 52 patients with septicaemia without cirrhosis. The incidence of septicaemia was higher in the cirrhotic group (4.25 p. 100) than in the control group (0.64 p. 100). The overall incidence of cirrhosis in patients with septicaemia was 19 p. 100. Nine of the 22 cirrhotic patients and 16 patients in the control group died. Prognostic factor common to both groups of patients were: shock, coma, delayed apyrexia and the isolation of more than one infecting organism on blood culture. Poor prognostic factors specific to the cirrhotic patients were the presence of ascites, especially if infected, and signs of hepatocellular failure.

Aged↗