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Biomedical subjects

M A Thomson

Publications and source records attributed to M A Thomson.

70 records · Page 4Linked to original sources
PubMed1979

Ammon's horn commissural responses in young rabbits.

Different responses evoked by stimulation of contralateral hippocampus at various levels are examined in new-born rabbits up to 1 month of age. Commissural fibres coming from the CA3-CA4 reach the contralateral regio superior (CA1) essentially at the st. oriens levels. CA1 responses elicited by stimulation of the contralateral CA1 in the st. oriens (commissural CA3 fibres) or in the st. radiatum (Schaffer's collaterals) are present at any age. For the regio inferior (CA3-CA4), the distribution of commissural fibres is more diffuse. Before 5--6 days, CA3-CA4 fields do not respond to a contralateral stimulation and do not give contralateral responses, showing that fibres and cells are not yet organized.

Animals↗
PubMed1979

Haemolytic anaemia of pregnancy.

Haemolytic anaemia apparently induced by pregnancy is reported in an otherwise healthy woman, with a negative family history. Folate deficiency, haemoglobinopathies, enzymopathies, hereditary spherocytosis, paroxysmal nocturnal haemoglobinuria, interstitial haematomata, hypertensive toxaemia, auto-immunity and infections were excluded. The autohaemolysis test showed increased lysis in the presence of added glucose. This abnormality was corrected by insulin when excess glucose was present, but not by insulin alone. It is suggested that this patient's erythrocytes may have been altered by placental lactogen and/or prolactin in such a way as to make them abnormally dependent on insulin for the uptake of glucose.

Adult↗
PubMed1975

[Maturation of interhippocampal responses. Report and localization of inhibitory and excitatory synapses in the horn of Ammon of the young rabbit].

Extracellular recording from hippocampal areas of new-born rabbits up to 3 months of age was carried out to examine the responses evoked by stimulation of the contralateral alveus of CA1. In CA1, the extracellular potential fields show a positive wave whose amplitude is maximal at the somata of the pyramidal cells at any age. This positive wave has the same latency as an inhibitory postsynaptic potential induced in the same conditions and presumably represents inhibition at this level. In stratum oriens and at the top of stratum pyramidale, this positive wave is accompanied by ripples (at a frequency of about 200 c/sec) that are produced by basket cells. These ripples exhibit a very small amplitude up to 10 days of age. This positivity decreases in the depth towards the apical dendrite, reverses at the beginning of stratum radiatum and becomes rapidly negative. A second positive wave with ripples could be recorded from the layer of deep pyramidal cell somata belonging to the underlying CA3-CA4, only after 7 days. It is concluded that, in both the new-born and the adult rabbit, inhibitory synaptic action from contralateral stimulation is present on or close to the pyramidal cell somata, whereas excitatory action is located in the apical dendrites near the main branching.

Age Factors↗
PubMedDate not supplied

The relationship between changing values of pregnancy-associated plasma protein-A in late pregnancy and the onset of labour.

The pattern of change of PAPP-A was established in three separate groups of patients. Day-to-day change from the 38th week was measured in six healthy patients whose pregnancies ended in spontaneous labour. The slow fluctuations of PAPP-A suggest that values found in labour are a consequence of events prior to the onset of labour. Increases of PAPP-A during the last few days of pregnancy and into labour were compared in patients going into labour spontaneously and patients who were induced. The induced patients showed a sharper increase in PAPP-A during this interval than the spontaneous onset group. A comparison at an earlier stage of pregnancy of PAPP-A increase was made between normal pregnancies going into labour on or before 280 days and those who went into labour later. Between 31 +/- 1 and 35 +/- 1 weeks, those who delivered in the earlier group showed a sharper rise in PAPP-A. It seems likely that the behaviour of PAPP-A in late pregnancy is the consequence of uterine activity and it seems unlikely that an increasing level of PAPP-A in itself has anything to do with the initiation of spontaneous labour.

Female↗
PubMedDate not supplied

Group/hospital affiliation: possible barriers to medical staff integration.

Group practice administrators are understandably concerned about the drawbacks and the benefits of formal affiliation of their groups with hospitals or other healthcare institutions. An administrator may wonder: "Should we align ourselves with this particular institution at this time?" or "What kinds of formal arrangements should we enter into?" A good administrator is also a good negotiator, and as such, will try to consider and include the opinions of the other participants in actions involving his group. When considering affiliation with an organization, the administrator will try to understand the drawbacks and the benefits as seen from the other side of the fence.

Group Practice↗
PubMedDate not supplied

Nutritional growth retardation is associated with defective lung growth in cystic fibrosis: a preventable determinant of progressive pulmonary dysfunction.

Evidence for a relationship between nutritional growth retardation in cystic fibrosis (CF) and progressive pulmonary dysfunction was evaluated by a prospective longitudinal study of changes in nutritional growth parameters, in relation to changes in pulmonary function data, in 61 moderately affected CF patients, aged 5-17 yr, during the equilibrated phase of lung growth. Age, sex, initial and serial weight and height Z scores, body cell mass (BCM) by total-body potassium (TBK) analysis, and changes in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), excluding data during pulmonary exacerbations, were analyzed by multiple regression analyses. The only significant predictor of change in FVC (best-fit model) was change in BCM, expressed as TBK (g/yr), TBK for age (percentage predicted), and TBK for height (percentage predicted) (p < 0.01). Standard anthropometric variables were not predictive. No reliable predictive model emerged for changes in FEV1. Relative decline in TBK for age was strongly predictive of decline in FVC (percentage predicted) accounting for 23% of this change. Patients with normal growth of the BCM had significantly less decline in FVC than those with retarded growth of the BCM (a fall of 2.5 vs. 6.8%/yr, p < 0.01). Impaired growth of the metabolically active BCM appears to be associated with progressive lung dysfunction in CF, possibly mediated by impaired lung growth. Achieving optimal nutrition and growth may minimize the progressive decline in pulmonary function commonly seen in this disease.

Adolescent↗