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Biomedical subjects

I M MacDonald

Publications and source records attributed to I M MacDonald.

45 records · Page 3Linked to original sources
PubMed1987

Linkage relationships of X-linked choroideremia to DXYS1 and DXS3.

Choroideremia is a distinct blinding condition with an X-linked pattern of inheritance. We have analyzed two RFLPs, DXS3 and DXYS1, for linkage with the choroideremia locus (TCD) within three kindreds. A maximum LOD score of 3.98 was obtained at theta = 0.14 for TCD:DXS3. The summed maximum LOD score from this study and from previously published TCD:DXYS1 data is 5.23 at theta = 0.05. Contrary to previous reports, the present data demonstrate that these two RFLPs are not tightly linked to the choroideremia gene locus.

Choroid↗
PubMed1987

Gene mapping of X-linked choroideremia with restriction fragment-length polymorphisms.

Choroideremia is a sex-linked chorioretinal disorder that causes blindness in affected males. The gene for choroideremia has recently been localized by means of recombinant DNA technology to a region of the X chromosome, Xq13-22. We have used two DNA probes, both specific for this region, to study three affected families. The results of linkage analysis of restriction fragment-length polymorphisms (RFLPs) revealed by these probes suggest that in the three families the gene for choroideremia may not be as closely linked to the region of the X chromosome as was previously reported. The estimated degree of linkage between an informative RFLP and the disorder should be considered before predictive testing is offered to people at risk in affected families.

Adult↗
PubMed1987

Norrie's disease in a French-Canadian kindred: attempt to detect carriers by DNA analysis.

In a French-Canadian kindred four male cousins are affected with Norrie's disease, a rare X-linked recessive disorder. Three have university education, and the fourth has some developmental delay. Only one is microcephalic. All have mild to severe hearing deficit, although only three were aware of their hearing loss. Linkage analysis of DNA from family members with the probe L1.28 failed to detect female carriers.

Adult↗
PubMed1984

Corneal pathology and aniridia associated with partial trisomy 2q, due to a maternal (2;6) translocation.

A newborn with partial trisomy 2q, due to a maternal (2;6) translocation is presented. The baby had microcephaly, a prominent forehead, hypertelorism, a broad nose with a flat nasal bridge, a long philtrum, micrognathia, and low set ears which are common to cases with partial 2q trisomy. Additional findings of aniridia and marked corneal pathology are reported.

Chromosomes, Human, 1-3↗
PubMed1981

Inhibition of whole blood antibody dependent cellular cytotoxicity by heat aggregated human IgG.

Inhibition of the whole blood antibody dependent cellular cytotoxicity (ADCC) of a lymphoblastoid cell line by heat aggregated human IgG (HAI) is described. Optimal sensitising antibody and effector cell concentrations were established to permit the detection of 0.1 microgram/ml HAI. Conditions which avoid the ADCC inhibitory effects of normal human sera were defined. Twelve paired normal human sera were stored at -70 degrees C for prolonged (greater than 3 years) and shorter (less than 6 months) periods of time. Sensitised sheep red cells were used to determine complement depletion in serum dilutions heated at 40 degrees C, 45 degrees C, 50 degrees C. Concentrations of human IgG (1 000-0.1 microgram/ml) were prepared in foetal calf serum before heating at 63 degrees C for 30 min to aggregate the IgG. ADCC inhibitory activity, frequently characteristic of normal human serum was minimised (less than 10%) when sera were stored at -70 degrees C and heated to 50 degrees C for 30 min to inactivate serum complement. This assay provides an economical, reproducible and sensitive test for the detection of circulating IgG complexes.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1980

Human renal allograft rejection is predicted by serial determinations of antibody-dependent cellular cytotoxicity.

The early recognition and prompt treatment of rejection may minimise damage to renal allografts. Preliminary studies showed whole blood effector cell function in a constant antibody-dependent cellular cytotoxicity (ADCC) assay system to be suppressed in recipients with stable renal function. To investigate the possible role of ADCC in the rejection process, serial estimates were performed in 29 consecutive recipients of cadaveric kidneys. The generation of ADCC, as measured in vitro, preceded the biochemical confirmation of an impending rejection episode by 3 to 5 days for 31 of 33 episodes experienced by 23 recipients. Statistical analysis (X2) demonstrated a highly significant correlation between ADCC generation as measured in vitro and subsequent episodes of graft rejection. In contrast, six recipients who did not experience rejection episodes during the first 3 months postgrafting showed no evidence of ADCC activity. Thus, ADCC may be used to identify rejection earlier than has previously been possible.

Antibodies↗
PubMed1977

High dosage haloperidol in chronic schizophrenia.

In a double blind chlorpromazine-controlled trial, high dosage haloperidol (100 mg daily) given for three months, appreciably improved the mental state of male chronic 'drug resistant' schizophrenic inpatients in the rehabilitation/long-stay unit of one psychiatric hospital. The results of a three-month follow-up suggested that the improvement could be maintained in some patients on lower doses of the drug. Serious extrapyramidal side effects were not seen at high doses. However, the majority of patients on haloperidol showed a deterioration in ward behaviour, possibly related to drowsiness, and developed raised serum alkaline phosphatase levels. These side effects disappeared in the follow-up period when either the drug was discontinued or the dose of haloperidol reduced.

Adult↗
PubMedDate not supplied

The effect of topical cysteamine drops on reducing crystal formation within the cornea of patients affected by nephropathic cystinosis.

We studied the usefulness of topical cysteamine ophthalmic drops in reducing crystal formation within the corneas of patients affected by nephropathic cystinosis. A dosage of 0.3% cysteamine given four times daily was chosen as a more manageable method than a previously reported protocol of hourly administration of 0.11% drops. No reduction in crystal formation was observed in our patients; they were followed for seven months.

Administration, Topical↗