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Biomedical subjects

R M Anderson

Publications and source records attributed to R M Anderson.

At least 361 records · Page 20Linked to original sources
PubMed1977

Septum primum defect repair.

Two technical maneuvers in septum primum defect repair have resulted in improved mitral valve function and security against heart block. One maneuver, critical to restoring mitral competence, is accurate reconstruction of the leading edge of the mitral valve. A second maneuver, suturing the septal defect patch at its inferior aspect to the mitral valve near the annulus instead of to the inferior septal defect margin or to the tricuspid annulus, eliminates the hazard of atrioventricular node or bundle injury.

Heart Block↗
PubMed1977

Correction of anomalous subdiaphragmatic inferior vena caval drainage of the right pulmonary veins (scimitar syndrome).

Correction of anomalous infradiaphragmatic inferior vena caval drainage of the right pulmonary veins can be repaired under conventional cardiopulmonary bypass by placing a circumferential tape below the diaphragm between the hepatic veins and the scimitar vein entrance. During repair, creation of an atrial septal defect in the distorted septal-left atrial junction of scimitar syndrome is facilitated by first incising the anteromedial aspect of the fossa ovalis to better delineate the optimal posterolateral margin. A case history illustrates the technique.

Child↗
PubMed1977

Hemolysis due to chemical contamination of clinical perfusion apparatus.

A chemical contaminant found on the interior surface of the extracorporeal apparatus manufactured by the William Harvey Corporation was believed to have caused severe hematuria in 2 children. The biological activity of the contaminant was tested by mixing 50 ml of whole blood in contaminated cardiotomies; after 5 minutes of exposure lysis of one-sixth of the red blood cells was found. This hemolytic agent was concluded to be bisphenol A dissolved in an organic solvent, but the mechanism of contamination was never found.

Benzhydryl Compounds↗
PubMed1977

Experimental investigations on the behaviour of the cercariae of an ectoparasitic digenean Transversotrema patialense: general activity patterns.

The activity patterns of the cercariae of Transversotrema patialense have been examined by monitoring the behaviour of individual larvae. Records of three different behavioural modes, namely active, tail-first swimming, passive dropping and resting periods were made separately. The age- and temperature-dependence of the activity patterns during the spontaneously active life of the cercariae were examined and estimates made of the absolute speeds of swimming and dropping. Through the temperature range 25--32 degrees C, the spontaneously active life of cercariae declined from about 18 h to about 6 h. Within this interval, after an initial period of high activity rates, a gradual decline in activity followed. The decline was a result of a decreasing frequency of swimming events rather than any change in the durations of such events. The neural control and energetic significance of the cercarial activity patterns are discussed.

Animals↗
PubMed1976

Development of onion bulb neuropathy in the Tremebler mouse. Morphometric study.

The Trembler mouse is a neurological mutant showing dominant inheritance. The periopheral nerves show a delay in myelination, segmental demyelination and the development of an onion bulb neuropathy. Using electron microscopy a comparative morphometric study of nerve fibres in the sciatic nerve in normal and Trembler mice was made. The animals ranged in age from 3 days to adult. The following features were noted: 1. Mean axon diameters of the Trembler mice were smaller than normal at all ages. 2. Myelination was delayed and myelin was thinner than normal in the Trembler mice. 3. The ratio of myelin thickness to axon diameter was reduced in Trembler mice. 4. There were no significant quantitative or qualitative differences observed between middle and distal levels of Trembler nerves. The balance of evidence from these findings and the previous morphological studies is in keeping with the suggestion that the primary lesion resides in the Schwann cell.

Age Factors↗
PubMed1976

Seasonal variation in the population dynamics of Caryophyllaeus laticeps.

The biological parameters which generate seasonal fluctuations in the size of populations of Caryophyllaeus laticeps are examined in detail. A mathematical model is formulated to describe the dynamics of the adult parasite within the fish host Abramis brama, and the predictions of the model are compared with observed population data. The seasonality of parasite population size is shown to be caused by the combined effects of a temperature dependent mortality rate and flucate of larval parasites. The observed overdispersed distribution of adult parasite numbers within the host population is shown to be generated by variability in feeding habits between individual members of the fish population. The theoretical population model is used as a framework for the investigation of, among other factors, the comparative influences of the immigration and death rates on the dynamics of the adult parasite, the future behaviour of the system under altered environmental conditions and the importance of chance effects in the dynamics of individual parasite populations within a single host. The stability of the dynamics of the complete life-cycle of C. laticeps is discussed in relation to the inherent biological complexity of host/helminth parasite interactions.

Animals↗
PubMed1976

The influence of duration of circulatory arrest at 20 degrees C on cerebral changes.

In infants and piglets subjected to periods of circulatory arrest at 20 degrees C there was close correlation between duration of arrest and delay in return of electroencephalographic activity. Post mortem studies demonstrated histological evidence of brain damage in patients after circulatory arrest at 20 degrees C. Similar histological changes were demonstrated in piglets, including some who had complete E.E.G. and clinical recovery from circulatory arrest.

Animals↗
PubMed1975

An experimental study of the survival characteristics, activity and energy reserves of the hexacanths of Hymenolepis diminuta.

Similar survival characteristics were demonstrated for hexacanths of Hymenolepis diminuta incubated in Tyrode's solution with or without a glucose supplement (0-50 mg/ml). The survival rate of hexacanths in all media tested was shown to be age-dependent and led to a maximum life-span of approximately 11 h. The amount of energy reserves, as measured by microdensitometric determination of PAS+ material, declined rapidly in time to a plateau at approximately 8 h. Residual PAS+ matter present beyond that period was interpreted as structural and thus non-utilizable material. The rate of activity as measured by hook movements declined more rapidly, and continuous hook cycles were rarely observed after 2 h and ceased after 4 h. A close correlation was demonstrated between the decline in PAS+ material and the total number of hook cycles completed per unit of time. The quantitative results on survival, energy reserves and activity are discussed in relation to the penetration of hexacanths into the haemocoele of the intermediate host.

Culture Media↗
PubMed1975

Intercostal muscle biopsy in human neuromuscular disease. Histochemical and electron microscopic studies.

External intercostal muscle biopsies were examined histochemically and by electron microscopy. The use of this muscle allowed correlation with physiological and pharmacological studies on the same specimens. Changes observed in musclar dystrophy and motor neurone disease resembled those previously described in biopsied limb muscle and underline the particular usefulness of this preparation in the study of human neuromuscular disease.

Adenosine Triphosphatases↗