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Biomedical subjects

J Morissette

Publications and source records attributed to J Morissette.

70 records · Page 4Linked to original sources
PubMed1980

Hearing loss among miners claiming compensation.

Otological and audiological evaluations were performed on 278 miners claiming compensation for noise-induced hearing loss (NIHL). Of the total sample, 28.7% had to be excluded as cases of nonmining NIHL. Of the cases of diagnosed as NIHL, approximately 50% showed an actual hearing impairment as based on a low fence of 25 dB for the average hearing levels at 0.5, 1, and 2 kHz, and 63% as based on the average hearing levels at 0.5, 1, 2, and 3 kHz for exposures of 15 to 49 years. No significant difference in NIHL was apparent except at 2 kHz between subjects exposed to intermittent vs intermittent-continuous noise. It was difficult to differentiate NIHL from sensorineural losses of other causes and impossible to apply an adequate correction factor for presbycusis.

Adult↗
PubMed1980

Thyroxine-binding globulin capacity and concentration evaluated from blood spots on filter-paper in a screening program for neonatal hypothyroidism.

We describe a simple method for evaluating thyroxine-binding globulin capacity and concentration from a single 1-cm blood spot on filter-paper used in a screening program for neonatal hypothyroidism. This method permits prompt diagnosis of about 90% of the infants with thyroxine-binding globulin deficiency in our abnormal low-thyroxine, low-thyrotropin population. There was excellent equivalence between results obtained by our method and by the method of Chopra et al. (J. Clin. Endocrinol. Metab. 35:565, 1972), and minimal overlap between the population with low thyroxine-binding globulin and the low-thyroxine, normal thyrotropin population. We recommend this method to all programs in which a primary thyroxine measurement is used in screening for congenital hypothyroidism.

Blood Specimen Collection↗
PubMed1979

Blood thyroxine concentration is lower in low-birth-weight infants.

From out data bank, we analyzed results for thyroxine concentration in blood samples spotted on filter paper from different age groups (one to nine days postpartum) of our low-birth-weight and normal population. It was significantly lower in the low-birth-weight infants in almost all the age groups, and in both groups it significantly declined after postnatal day 5. The influence of weight is more important in the low-birth-weight population, but does not completely explain the smaller values. The results indicate that blood samples used in screening for congenital hypothyroidism in the neonate should be taken on postnatal days 3 to 5, and if a recall specimen is collected on days 5 to 9, one should expect the thyroxine concentration in the second specimen to be lower than in the first.

Aging↗
PubMed1978

Modification of a screening program for neonatal hypothyroidism.

From our experience in the screening of 212,000 newborn infants, we have devised a flow chart for processing T4 and TSH measurements obtained from initial filter paper blood spots. To date, all infants with thyroid dysfunction or TBG deficiency have been detected. Of the population screened, 1.84% require a spot TSH determination, and 1.1% require repeat determinations of T4.

Filtration↗
PubMed1978

Polystyrene tube immunoradiometric assay for human alpha1-fetoprotein, and its use for mass screening.

We describe a two-site immunoradiometric assay for human alpha1-fetoprotein, with use of antibody-coated polystyrene tubes as solid phase. The sensitivity, precision, and simplicity of this system make it eminently suitable for mass-screening purposes. We currently use it for neonatal detection of hereditary tyrosinemia in the Province of Quebec; measurements are made on blood spotted and dried on paper. This system could be well suited for other mass surveys, such as prenatal screenings for fetal abnormalities.

Amino Acid Metabolism, Inborn Errors↗
PubMed1977

The inbreeding coefficients of the Hadza.

A systematic tabulation is provided of the frequency of different types of inbreeding in the Hadza. Genealogical information was obtained for 931 individuals, alive and dead. Inbreeding was encountered with 165 individuals. There were 49 different types of inbred genealogy. No attempt was made to calculate an average inbreeding coefficient and the reasons for this are given in the text.

Consanguinity↗
PubMed1976

Factors influencing results for thyroxine concentration in blood, as measured in paper filter spots in a screening program for neonatal hypothyroidism.

To reduce the number of false-positives in our screening program for neonatal hypothyroidism, we investigated the effect of age, body weight, and interval between sampling and analysis on results for filter paper spot thyroxine determination. The statistical analysis included an analysis of covariance. The age of the infant did not influence the results, the interval influenced them minimally, but weight did require a correction factor of about 0.16 ng/kg below the mean weight. This correction factor should reduce our false-positives from 0.75% to 0.60%. Furthermore, because all hypothyroid infants had results that fell more than 2.8 SD below the geometric mean, we intend to measure thyrotropin concentrations in the blood eluate of all the spots with a thyroxine concentration below that cut-off point.

Body Weight↗
PubMedDate not supplied

A craniometric study of bicoronal craniosynostosis (BCC).

We compared 20 cases of bicoronal craniosyntosis (BCC) using the linear and angular values of the normal statistical material for the same age and sex. The skull in BCC is significantly shortened and flattened but with normal width. The height of the frontal arch (FNBR) is significantly decreased. The base of the skull is depressed with angle AB2 significantly increased, and angle NTNO significantly decreased and, even in some cases, with negative angular values. This is inducing a sinking of LEA (length from N to T), and in some cases LEA is lower than the line LNO (distance from N to O). The cephalic index (CI) was significantly increased, and the calculated cranial capacity (CC) was significantly decreased. Bregma (BR) is moving anteriorly in BCC, inducing an anterior movement of the calvaria with a bulge around BR. In this anterior movement we designate lack of positive occipital rotation. In BCC there is an evident lack of positive occipital rotation. Superimposing our drawings on the reference line NBA, we found for the first time a movement of anatomical landmarks similar to that observed in the negative occipital rotation in vestibular orientation.

Cephalometry↗
PubMedDate not supplied

A craniometric study of sagittal craniosynostosis (SC).

Twenty cases of sagittal craniosynostosis (SC) were compared with the linear and angular values of the normal statistical material for the same age and sex. There were significantly increased values of the length of the skull (LI) and the height of the frontal arch (FNBR) and significantly decreased width (WI) and height of the skull (HI) as well as the depth of the cerebellar fossa (PEP). The length of the anterior cerebral fossa (LEA) remained within normal limits and the distance BRPI between bregma (BR) and the internal protuberance (PI) was within normal limits or increased. The angular value of the basal angle (angle NT-BA, AB2) decreased significantly and the angle NTNO (angle between the lines NT and NO) and the angle BRTPI (the angle between the lines TBR and TPI) were significantly increased. The cephalic index (CI) was significantly decreased. The cranial capacity (CC) is normal or decreased. There is demonstrated an occipital over-rotation of the skull.

Cephalometry↗