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Biomedical subjects

A Lucas

Publications and source records attributed to A Lucas.

At least 343 records · Page 19Linked to original sources
PubMed1982

[Plasma catecholamines in dogs during cold exposure and muscular exercise at the same level of energy expenditure].

Plasma epinephrine, norepinephrine and substrate concentrations (glycemia, free fatty acids (FFA), lactic acid) have been compared in same dogs exposed to cold then made to perform a running test. Under both conditions energy expenditure was increased to the same level for each dog, approximately 7 fold the metabolic rate at rest: 1. Catecholamines were increased in cold exposed as well as in running dogs. However plasma epinephrine and norepinephrine concentrations were respectively 2,5 and 3 times higher during cold exposure than they were during muscular exercise. 2. Under both conditions hyperglycemia was observed; however it was more noticeable during cold exposure than during running. Lactic acid increased under both conditions but average concentrations were not significantly different. FFA were increased only during cold exposure. 3. It may be concluded that for the the same level of energy expenditure a greater degree of involvement of the adrenal medulla and sympathetic nervous system is to be found during cold exposure than during exercise. This difference may partly explain that the relative contribution of substrates to the energy expenditure could be different during cold exposure and muscular exercise.

Animals↗
PubMed1982

Thoracic empyema.

Explore the source record for details and available documents.

Adolescent↗
PubMed1981

Differences in the pattern of milk intake between breast and bottle fed infants.

Two hundred and nine 6-day-old healthy term infants were test weighed either during bottle feeding (n= 77) or breast feeding (n=132). Cross-sectional data collection avoided repeated interruptions of individual feeds. Bottle fed infants (fed ad libitum) and breast fed infants consumed a similar feed volume (respectively, 67 +/- 2 ml versus 75 +/- 6ml, mean +/- S.E.M.) over a similar period of time (mean 25 min); yet the pattern of milk flow during feeding was significantly different in the two groups. In bottle fed infants, there was a linear pattern of milk intake over the first 10 min of feeding, by which time 81% of the feed has been consumed, contrasting with a biphasic intake pattern in breast fed infants in whom a total 84% of the feed was consumed either in the first 4 min or between 15 and 19 min after the start of the feed. It is speculated that these differences in the pattern of milk intake could influence the physiological responses to feeding and might account for differences between breast and bottle fed infants in gut hormonal responses to milk feeds.

Bottle Feeding↗
PubMed1981

Effect of sodium nitroprusside on postoperative blood loss in the cardiac surgical patient.

Sodium nitroprusside (SNP) is known to inhibit platelet aggregation and has been implicated in postoperative hemorrhagic complications. Because it is a useful agent for treating postoperative hypertension and low cardiac output in the cardiac surgical patient, the authors retrospectively reviewed the course of 53 patients undergoing open heart procedures on cardiopulmonary bypass. Twenty-three patients received SNP and 30 did not. There were no differences in baseline hematological or clotting profiles, liver functions, bypass or cross-clamping times or heparin/protamine requirements between the two groups. Analysis revealed no significant differences between the groups in blood product requirements, actual mediastinal drainage, or postoperative measurements of routine clotting parameters. Although biochemical inhibition of platelet aggregation can be demonstrated, the use of SNP in the cardiac surgical patient has no apparent clinical effects which sould detract from its utility in treating hypertension or low cardiac output.

Cardiac Output, Low↗
PubMed1981

Treatment of preinvasive disease of the cervix by cone biopsy.

During the years 1952--1977, 646 patients with abnormal cervical cytology underwent one biopsy (595) or ring biopsy of the cervix. The histological diagnoses were invasive carcinoma 20 (3%) microinvasive carcinoma 16 (2%), carcinoma in situ and severe dysplasia 418 (65%), other dysplasias 149 (23%). The remainder, 43 (7%) had no demonstrable abnormality. Following biopsy 41 (7%) patients with non-invasive disease had abnormal cytology within a year of biopsy. A further 12 (2%) developed abnormal cytology after one year. These recurrences occurred up to 12 years after the initial treatment, and in one patient invasive squamous carcinoma has developed.

Biopsy↗
PubMed1981

Metabolic and endocrine responses to a milk feed in six-day-old term infants: differences between breast and cow's milk formula feeding.

There is little information on the metabolic and endocrine responses to milk feeding in the neonatal period particularly in relation to the model of nutrition and composition of the milk. Plasma concentrations of insulin, glucagon and gastric inhibitory polypeptide (GIP) together with blood levels of glucose, ketone bodies, pyruvate, lactate and glycerol were measured pre- and post-prandially in 79 health six-day-old term infants who had been either breast fed or fed on a modified cow's milk formula (Cow and Gate Premium) from birth. Formula fed infants had a greater insulin and GIP response to feeding and their basal and postprandial blood ketones were considerably lower than in breast fed infants. In addition a significantly greater post feed rise in both lactate and pyruvate concentrations was observed with formula feeding. These results may have significant implications regarding infant feeding and postnatal metabolism.

Animals↗
PubMed1981

Plasma neurotensin in term and preterm neonates.

The new ileal peptide neurotensin has not been studied hitherto in the human neonate. Plasma concentrations of neurotensin were measured by radioimmunoassay in 276 healthy term or preterm infants either at birth or pre- or post-prandially during the neonatal period. In addition, a group of 10 6-day-old preterm infants were studied who had never been enterally fed on account of hyaline membrane disease. Plasma neurotensin values were obtained also in 12 healthy fasting adults. Term infants had higher plasma neurotensin concentration than preterm infants at birth. Both groups showed a significant postnatal surge in basal (pre-prandial) neurotensin concentrations exceeding adult values, but no postnatal neurotensin elevation was found in the unfed group. In preterm infants, who were studied further into the neonatal period than term infants, there was a progressive increase in the rise of neurotensin following a milk feed, with a massive neurotensin response by 24 days of age. In 6-day-old term infants, the neurotensin response to bottle feeding was significantly greater than to breast feeding. These findings add further weight to the concept that neurotensin may be of physiological importance as a gut hormone. The high neurotensin levels and large feed responses seen in neonates may indicate a unique role for neurotensin in early life.

Bottle Feeding↗
PubMed1981

The control of the adaptation of the human neonate to postnatal nutrition.

Major changes occur in the function of several physiological systems after birth which enable the neonate to adapt to postnatal nutrition. It is suggested that the secretion of gut and pancreatic hormones in response to enteral feeding has a key role in triggering a cascade of developmental changes in gut structure and function, and in the relation of pancreatic endocrine secretion to intermediary metabolism. Evidence to support this hypothesis is presented.

Acclimatization↗
PubMed1980

Emergency laparotomy immediately after coronary bypass.

Eight patients required emergency laparotomy in the immediate postoperative period after coronary artery bypass (CAB). Cardiac complications were few and minor. Sepsis was the major cause of mortality. In the two patients who died, delay in operative management contributed to their deaths. The lack of cardiac causes of morbidity and mortality in our series and others suggests that a stable postoperative coronary bypass patient represents a better surgical risk than the same patient preoperatively. Therefore, aggressive management, including early laparotomy, for suspected intra-abdominal pathology after CAB is recommended to avoid uncontrollable sepsis and death.

Abdomen, Acute↗
PubMed1980

Breast-feeding and plasma oxytocin concentrations.

The patterns of response of oxytocin to a breast feed were studied in 10 mothers in the first week post partum. The initiation of lactation did not appear to be related to release of oxytocin. In established lactation an oxytocin response did not appear to be essential for adequate milk flow and did not occur always at the time of peak milk flow. The only factor identified that positively correlated with release of oxytocin was multiparity. In those subjects who showed a response the hormone was released in surges, some of which persisted in the circulation for less than one minute. These findings cast some doubt on the conventional view that release of oxytocin is essential for satisfactory milk flow during breast-feeding.

Breast Feeding↗
PubMed1980

Breast vs bottle: endocrine responses are different with formula feeding.

Differences in pancreatic and gut-hormone release between breast-fed and bottle-fed infants have not been documented although these hormones may play a key role in postnatal adaptation. In a study of 77 six-day-old healthy term infants, bottle-fed neonates ('Cow and Gate Premium') had significant changes in plasma-concentrations of insulin, motilin, enteroglucagon, neurotensin, and pancreatic polypeptide after feeding, whereas in breast-fed infants these changes were reduced or absent. Basal levels of gastric inhibitory polypeptide, motilin, neurotensin, and vasoactive intestinal peptide were also higher in the bottle-fed infants than in those who were breast-fed. These findings may partly explain differences in the deposition of subcutaneous fat and in stool frequency between breast-fed and bottle-fed neonates.

Bottle Feeding↗
PubMed1980

Maximum oxygen consumption in dogs during muscular exercise and cold exposure.

Maximum oxygen consumption for a short exhaustive work (Ex VO2 max) and for a severe cold stress (C VO2 max) were investigated in 8 dogs. Heart rate, plasma catecholamines and substrate concentrations were measured under both conditions. Mean C VO2 max was lower than mean Ex VO2 max. Heart rate and plasma lactate were also lower during cold exposure than during exercise. Average plasma epinephrine concentrations were not significantly different and average plasma norepinephrine concentrations were similar under C VO2 max and Ex VO2 max conditions. A positive correlation was found between plasma lactate and epinephrine concentrations measured under both conditions. It may be assumed that maximum oxygen consumption during muscular exercise is higher than during shivering thermogenesis. This difference does not seem to be due to differences in the involvement of the sympathico-adreno-medullary system.

Animals↗
PubMed1980

A human milk formula.

In view of the possible deficits in the energy value and protein content of human milk when used for feeding low birth weight preterm neonates, a method has been devised suitable for use in a human milk bank for making milk formulae from human milk products. Human milk formula (HMF) is produced by adding, to whole human milk, human cream, obtained by separation by centrifugation, together with salt-free and lactose-free human milk protein, extracted by simple dialysis and freeze-drying. This human milk formula is, therefore, enriched in energy, human milk fat, protein and salts (which may be added), to approach the current concept of an ideal milk formula(e) for preterm infants. In addition, the increased concentration of antimicrobial proteins achieved in HMF may offset any losses in these proteins caused by pasteurisation.

Dietary Fats↗