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Biomedical subjects

B Lennox

Publications and source records attributed to B Lennox.

At least 19 recordsLinked to original sources
PubMed1979

Hormonal and histological studies in a 61XXY bull.

A Friesian bull with bilateral testicular hypoplasia was diagnosed as having a pure 61XXY karyotype. The bull displayed normal sexual behaviour but was azoospermic. At 17 months, the animal's peripheral plasma androgen levels appeared to be lower than normal, and one testicle removed one month later showed small seminiferous tubules totally lacking in germ cells. The Leydig cell volume of this testis was well within the normal range but the tubule length was rather short. At 33 months of age an increase in peripheral plasma androgen levels was noted. In the remaining testis there had been both a considerable rise in Leydig cell volume and a fall in tubule length. These findings may be explained by the interaction of three factors; the effects of the abnormal karyotype, the increased maturity of the animal at 33 months and the reaction of the remaining testis to unilateral castration.

Androgens↗
PubMed1979

Tubule length and Leydig cell volume in the normal bull testis.

Data are presented on the size, Leydig cell content and seminiferous tubule dimensions of the normal bull testis. A method of estimating total tubule length, requiring only the measurement of testis volume and the number of tubule cross-sections in a unit area is described, and its applicability to the bull established. The average bull testis contains about 5.2 km of tubules.

Animals↗
PubMed1979

Comparison of admission criteria and medical school progress: preliminary results from a simple computer system.

The MFSEL system is designed to collect the data on entrants to the Glasgow medical course that was available to the Admissions Committee at the time of selection, and compare it with performance in medical school (and possibly later). The data collection has been made by the Admission Committee's secretary and the programming by a medical member with little previous experience and a minimum of professional help. Computing and data preparation costs have been low. Preliminary analyses indicate that selection has not been biased by the sex, class, or medical parenthood of entrants, and that the Scottish Sixth Year Studies examinations are a reliable predictor for student performance.

Adolescent↗
PubMed1978

Incidence of salivary gland tumours in Scotland: accuracy of national records.

Statistics on discharge diagnoses in Scotland during 1968-74 show the incidence of all tumours of major salivary glands to exceed 40/million population yearly. This is higher than in any other nationality except Canadian Eskimos. Studies in two hospitals showed that numerous errors occurred in reporting these tumours, but the figures were more likely to be too low than too high. Probably eastern Scotland at least has an unusually high incidence, although in other countries using different methods of analysis the reported figures are likely to be low. Statistics based on discharge diagnoses will continue to be neglected in research until the standard of completion of discharge diagnoses improves.

Diagnostic Errors↗
PubMed1975

Correlation of the effects of citric acid cycle metabolites on succinate oxidation by rat liver mitochondria and submitochondrial particles.

1. Succinate dehydrogenase is inhibited by citrate and beta-hydroxy-butyrate in a complex manner, both in mitochondria and submitochondrial particles. Kinetics of inhibition in the particles points to a competitive component in the mechanism involved. 2. Pyruvate, alpha-ketoglutarate, malate, and glutamate stimulate oxidation of succinate by mitochondria. 3. Stimulation by alpha-ketoglutarate and glutamate is not influenced by the presence of rotenone. 4. Stimulation by pyruvate is higher in the absence of rotenone and increases significantly in the presence of K+ and valinomycin. Pyruvate supplies in mitochondria reducing equivalents for malate dehydrogenase operating in the reverse direction-reduction of oxaloacetate to malate. 5. Stimulation by malate is higher in the presence of rotenone.

Animals↗
PubMed1975

Observations on the accuracy of point counting including a description of a new graticule.

The accuracy of point counting as a histometric technique depends very much on the number of points counted, and the number necessary varies greatly with both the level of accuracy required and the proportion the relevant tissue occupies in the section. It is shown that the number of "hits" is a more useful measure than the total number of points counted, and a simple rule derived for determining the number of hits necessary to achieve any necessary degree of accuracy. A method of progressive estimation of accuracy when attempting to measure the proportion of a tissue that is unevenly distributed is also described. The point-counting graticules commonly used, with 25 points, are inadequate with tissue proportions below 10%. A new graticule design, with 100 points optimally distributed, and usable as a 25-point array if required, is illustrated.

Histological Techniques↗
PubMed1974

The value of resits.

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Education, Medical, Undergraduate↗
PubMed1973

M.C.Q.s.

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Education, Medical↗