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Biomedical subjects

M Mclaren

Publications and source records attributed to M Mclaren.

4 recordsLinked to original sources
PubMed2000

Mean platelet volume is a useful parameter: a reproducible routine method using a modified Coulter thrombocytometer.

The principal physiological function of platelets is to promote haemostasis but they also contribute to thrombosis and atherogenesis. Platelet volume is a marker and possibly a determinant of platelet function in that large platelets are more active than normal sized platelets. Mean platelet volume (MPV), a measure of platelet size, reflects changes in either the level of platelet stimulation or the rate of platelet production. For these reasons, we have developed a sensitive instrument to measure platelet volume, which we believe is more reliable and specific than previously used instruments. It is based on a computer-interfaced Coulter Thrombocytometer and a pulse analyser including a high-speed baseline restorer. We have developed a reproducible method to assay MPV and from the histogram derived the median (MED) and the skewness (SK) values. We have looked at the effects of anticoagulant used and time elapse prior to assay. A normal range has been established for MPV which correlates directly with MED and inversely with SK. The MPV decreases with age but there is no difference between genders. We have demonstrated a negative correlation between whole blood platelet number and MPV and MED, and a direct relationship with the SK of the histogram of the platelet volume.

Adolescent↗
PubMed1993

Prevalence of maternal drug use near time of delivery.

Prenatal substance abuse is a problem of growing concern because of the negative effects it has on the health of the woman and developing fetus. To evaluate the prevalence of this problem in our community, anonymous toxicology studies were performed on 1,003 maternal urines. Samples were connected at time of delivery and selection bias was addressed. Results indicated that cocaine or marijuana metabolites were present in 4% of all urines. Among clinic patients, 12.4% tested positive (7.3% cocaine; 5.1% marijuana) and 1.3% tested positive among private patients (0.7% cocaine; 0.7% marijuana). Poor prenatal care was positively associated with substance use regardless of clinic or private care: 50% of those with fewer than three prenatal visits tested positive for cocaine or marijuana compared with 2% of those with more than three prenatal visits. Maternal age < 18 years did not predict substance use. Program planning in Connecticut should progress with these data in mind.

Adolescent↗
PubMed1989

Indices of calcium metabolism in women with hip fractures.

We have assessed indices of calcium metabolism in 41 women with hip fractures and compared them with two elderly control groups. The women with hip fractures had lower serum concentrations of albumin, 25-hydroxyvitamin D and osteocalcin than the controls. Serum concentrations of calcium, alkaline phosphatase and parathyroid hormone, as well as urinary hydroxyproline/creatinine ratios were similar in the three groups of women. The small reduction in serum osteocalcin concentration in fracture patients is consistent with the hypothesis that reduced osteoblast function may contribute to the osteoporosis which results in hip fracture.

Aged↗