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Biomedical subjects

J W Gerrard

Publications and source records attributed to J W Gerrard.

At least 19 recordsLinked to original sources
PubMed1994

Familial resemblance for immunoglobulin levels.

The familial resemblance for immunoglobulin A, D, E, G, and M levels was investigated with family data collected in Canada and the U.S., entertaining both multifactorial and single gene hypotheses. Significant familial effects were found for each of the immunoglobulins, and there was significant support for a major gene hypothesis for IgA and IgD levels. Whereas there have been several reports suggesting a major gene determinant for IgE levels, including that from our own Canadian study, analysis of the U.S. sample suggested that a multifactorial component parsimoniously explained the observed familial resemblance.

Analysis of Variance↗
PubMed1994

Neuropharmacological evaluation of movement disorders that are adverse reactions to specific foods.

Three cases are reported of patients who had episodic movement disorders triggered by foods or components of the diet. In the first patient, the movement consisted of shaking the head from side to side that was triggered by milk and a number of other foods. In the second patient, the movement consisted of a repeated shrugging of the shoulders that was triggered by egg and coffee. In the third, the movement consisted of rhythmic contractions of the arms and legs that were triggered by aspartame. The first patient agreed to participate in a study in which she drank 250 ml of skim milk, an amount sufficient to trigger head shaking, after pretreatment with drugs known to alter neurotransmission across beta-adrenergic, dopaminergic, GABAergic or purinergic synapses. At the doses used, propranolol and diazepam had no effect on the milk evoked movement disorder. Levodopa (plus carbidopa) blocked the reaction to milk. Haloperidol, salbutamol and theophylline by themselves triggered a reaction similar to that evoked by milk. These observations suggest that, in susceptible individuals, foods can trigger movement disorders through an action on dopamine and other neurotransmitter pathways in the brain. A videotape of the reactions of the first two patients is available.

Adult↗
PubMed1994

Phenylketonuria revisited.

This article describes the parts played by Bickel, Hickmans, Gerrard, and Woolf in the preparation of a formula low in phenylanine and in the treatment of the first child with phenylketonuria (PKU) with a low phenylalanine diet. As the child whom they were treating was 2 years old, and was already appreciably retarded mentally, the apparent improvement in her mental status was ascribed, by their medical colleagues, to the extra attention that the child was receiving and not to the biochemical changes noted in her blood.

Child, Preschool↗
PubMed1990

Sex-linked determinants for IgM?

Evidence for a sex-linked determinant of immunoglobulin M levels was sought using correlational and commingling analyses in a sample of 174 randomly selected nuclear families. While mean IgM levels in females were approximately 25% higher than that in males, the pattern of familial correlations did not follow the expectations under a sex-linked model, and there was no commingling in the distribution of IgM levels as expected when a trait is under the influence of a major gene.

Canada↗
PubMed1989

Commingling in the distributions of immunoglobulin levels.

Commingling in the distributions of five immunoglobulins from a Canadian sample of 810 Caucasians and IgE from a US sample of 935 Caucasians was investigated. For both the Canadian and US samples significant commingling was found in the child's but not the adult's IgE distribution. Contrary to expectations based upon the major gene hypothesis for IgM, we found no evidence for commingling in the IgM distribution. Finally, the distributions of IgA, IgD and IgG all evidenced significant commingling that may be the result of a single gene effect or the operation of a discrete environmental effect.

Adult↗
PubMed1986

IgE-mediated allergy to peanut, cow's milk, and egg in children with special reference to maternal diet.

Nineteen children with IgE-mediated allergy associated with strongly positive prick skin tests and RASTs to peanut or cow's milk and/or egg were studied. Seventeen of the children had been breast fed, ten had been exclusively breast fed for a minimum of 5 months. Reactions to these foods occurred on first exposure to the food in all but one instance, suggesting that in 18 instances sensitization had occurred antenatally or via the breast. A retrospective inquiry indicated that most of the mothers had had a generous intake of the food(s) to which their children were sensitized, but mothers of sensitized children did not consume more of these foods than the mothers of non-sensitized children; moreover, avoidance of the foods (peanut in two instances and egg in one) did not ensure freedom from sensitization to peanut and/or egg. Breast feeding by itself cannot be guaranteed to protect against the development of food allergy.

Anaphylaxis↗
PubMed1985

Demonstration of a common major gene with pleiotropic effects on immunoglobulin E levels and allergy.

Atopic disease is generally recognized to be familial, although specific genetic components have yet to be identified. High levels of a unique class of immunoglobulins, immunoglobulin E (IgE), have been shown to be associated with allergies. Several investigators have reported evidence indicating a recessive regulatory locus where an individual with the homozygous recessive genotype has persistently elevated levels of IgE. Willcox and Marsh [1978] have proposed a hypothesis relating IgE production and liability to become allergic. A test of this hypothesis was carried out in the present study. Bivariate segregation analysis of IgE levels and allergy was performed on 173 nuclear families, and the results indicate that an IgE regulatory locus contributes to the familial transmission of allergy. The results are further discussed in the context of the Willcox and Marsh hypothesis.

Adult↗
PubMed1984

Failure to thrive in the contented breast-fed baby.

This paper describes nine babies who appeared contented yet failed to thrive while being exclusively breast-fed. In each case the mother felt that her child was satisfied with the feedings. Following appropriate management all the infants were above the 80th percentile for both weight and weight for length. Five infants had achieved 110% to 120% and three more than 120% of the expected weight for length. This tendency to become overweight might be explained by inactivity or a defect in appetite control.

Body Height↗
PubMed1984

Food intolerance.

Explore the source record for details and available documents.

Food Hypersensitivity↗
PubMed1984

Familial infantile cortical hyperostosis in a large Canadian family.

Infantile cortical hyperostosis is a rare proliferative bone disease affecting infants under the age of 6 months. In 1961 a large family of French-Canadian origin in which 14 children in three generations were affected was described. Since then 20 new cases have been found in this family. This is the largest familial aggregation of this disease reported in the literature to date. On the basis of the findings in this pedigree, the familial form of the disease appears to be transmitted by a single autosomal dominant gene with incomplete penetrance and variable expressivity.

Abnormalities, Multiple↗
PubMed1984

Fragile (X) X-linked mental retardation. II. Frequency and replication pattern of fragile (X)(q28) in heterozygotes.

The frequency of cytologic expression and the replication pattern of the fragile (X) [fra(X)] were investigated in 28 fra(X) heterozygotes, of which 25 agreed to psychological assessment. One-third of the heterozygotes in this study are mentally retarded. The intellectually impaired carriers had a higher frequency of fra(X) and a higher proportion of early-replicating fra(X) than the normally intelligent carriers. The early-replicating fra(X) accounted for 39% of the variability in IQ and the late-replicating fra(X) for 12%. Age had a minimal inverse effect on fra(X) expression and replication pattern. Thus, it appears that mental retardation in females heterozygous for the fra(X) may largely be a function of the proportion of cells with an early-replicating, active X chromosome possessing the fragile site.

Adolescent↗
PubMed1983

Fragile (X) X-linked mental retardation I: relationship between age and intelligence and the frequency of expression of fragil (X)(q28).

Members of eight Saskatchewan families with fragile (X) X-linked mental retardation were studied in an attempt to relate frequency to age and intelligence. The mean IQ of 37 affected men was 35 (range 10-66). The mean IQ of 32 carriers was 88 (range 57-119), and the mean IQ of 13 females who remain at risk for being carriers, have no affected sons, and who failed to demonstrate the fra(X) was 100 (range 78-126). We demonstrated a significant inverse relationship between age and frequency of the fra(X) in carriers and in affected males. However, we demonstrated a more highly significant inverse relationship between frequency of the fra(X) and IQ in carriers but to a lesser extent in affected males. Of 32 carriers, only 3 (9.4%) did not demonstrate the fra(X) after addition of 5-fluoro-2'-deoxyuridine (FUdR) to the folic acid and thymidine-reduced culture medium. From these data we would recommend that chromosome studies in individuals at risk for fra(X) X-linked mental retardation be carried out at the youngest age and that the addition of FUdR to culture medium is useful in carrier identification. It is clear that, in at least the carriers, a lower expression of the fra(X) is highly significantly correlated to higher intelligence.

Adolescent↗
PubMed1983

Alpha 1-antitrypsin phenotypes in Canadian Metis.

Alpha 1-antitrypsin phenotyping was performed on serum of 344 Metis living in an isolated northern Saskatchewan community. Only PiM and PiMZ phenotypes were observed with phenotype frequencies of 98.5 and 1.5 respectively. Gene frequencies were 0.993 for PiM and 0.007 for PiZ. The low frequency of non-M phenotypes is similar to that in another population of North American natives, the Eskimos of Igloolik as well as Finnish and Norwegian Lapps.

Canada↗
PubMed1983

Sensitization to substances in breast milk: recognition, management and significance.

Details are given of the presenting symptoms in 73 breast fed babies sensitive to traces of food in breast milk, most commonly cow's milk, taken by their mothers. They are contrasted with the findings in formula fed babies with cow's milk allergy whose symptoms are precipitated by large amounts of antigen. It is concluded that there are at least two types of food allergy. One is IgE-mediated and is triggered by trace amounts of antigen. The other is not IgE-mediated and is triggered by large amounts of antigen.

Breast Feeding↗
PubMed1983

Food allergy: two common types as seen in breast and formula fed babies.

Cow's milk allergy can develop in both breast and formula fed babies. The allergy developing in breast fed babies is triggered by trace amounts of antigen, tends to cause severe reactions and may persist for several years. The allergy developing in formula fed babies is triggered by large amounts of antigen, is not associated with either positive prick tests or with anaphylactic reactions and often subsides spontaneously.

Adult↗
PubMed1981

IgD levels in white and Metis communities in Saskatchewan.

Levels of serum IgD have been measured in white and Metis (Cree Indian) communities in Saskatchewan. IgD levels in the Metis were, on average, 10 times as high as those in the white population. In both groups IgD levels rose rapidly to reach, by the age of two years, levels which did not differ significantly from those found in the adult. From the age of two to three years, levels in the populations remained relatively constant with time, although levels in any of individual may rise or fall over a three-year period by factors ranging from 10 to 20.

Adolescent↗