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Biomedical subjects

K Baker

Publications and source records attributed to K Baker.

At least 127 records · Page 7Linked to original sources
PubMed1985

Efficacy and pharmacokinetics of febantel and ivermectin in red deer (Cervus elaphus).

A trial was conducted to determine the efficacy and pharmacokinetics of fehantel and ivermectin in six month-old red deer calves (C. eluphus). Five calves received febantel by mouth at 7.5 mg/kg, five received a subcutaneous injection of ivermectin at 200 microg/kg and five were controls. All calves were killed seven days later and total lung and gastrointestinal worm counts carried out. Febantel was 85 and 99.8% efficient in removing immature and mature Dictyocaulus viviparus, respectively, and ivermectin was 100% efficient in both cases. There was no gastro-intestinal nematodes in any of the treated calves, compared to an average of 619 in the control calves. The metabolism of febantel resulted in plasma levels of fenbendazole, oxfendazole and sulphone for which the common curves fitted by compartmental model peaked at values (standard errors)-of 0.46 (0.03), 0.41 (0.02) and 1.73 (0.07) mg/l after approximately five, nine, and thirteen hours and were undetectable at 30,72 and 120 hours respectively. There was considerable variation among animals in response to ivermectin. The fitted common curve had a peak plasma level of 15.8 (0.08) microg/l at 20 hours after injection, which had dropped to 7.9 (1.1) microg/l seven days after injection. It was estimated that after 15 days plasma levels of ivermectin would not be detectable. It is concluded that the injectable form of ivermectin tested is a highly efficient anthelmintic in deer, and that plasma levels persist for over a week after subcutaneous injection. Fehantel is very efficient against mature D. viviparus in deer, but its reduced efficiency against immature D. viviparus may relate to the deer;s ability to metabolise and excrete benzimidazoles more quickly than sheep and cattle.

Journal Article↗
PubMed1984

Echocardiographic evidence of left ventricular bands in infants and children.

M-mode and two-dimensional echocardiographic studies were carried out on 100 consecutive neonates, infants and children to evaluate the incidence of left ventricular chordae or bands. These fibromuscular structures were noted in 61 subjects and were seen to traverse both the long and short axes of the left ventricle. Although a single left ventricular band was usually noted, several subjects had multiple bands. These bands were seen in normal subjects and in patients with a wide variety of congenital cardiac lesions. Distortion of left ventricular geometry was noted in one subject. Identification of these linear echoes is essential to allow differentiation of left ventricular bands from true anatomic left ventricular outflow tract obstruction or septal thickening.

Adolescent↗
PubMed1984

Family-focused cardiac rehabilitation. A role supplementation program for cardiac patients and spouses.

A review of the literature yields general agreement among investigators regarding the responses of both patients and spouses to a cardiac event. Anxiety, depression, low self-esteem, marital and sexual dysfunction, and psychosomatic symptoms have been consistently documented up to 1 year following a myocardial infarction or cardiac surgery. Although the patient's physiologic status sets limits on the potential level of recovery, psychosocial variables are new recognized as playing a critical role in the rehabilitation process for both patients and their families. Our 3-year experience with patient-spouse groups supports the view that spouses must be involved throughout the rehabilitative process and that effective participation is provided within the context of a role supplementation program. Such a program facilitates direct and consistent communication as well as flexibility within and between roles. Both end points are critical to the re-establishment of family equilibrium and the ultimate recovery of the cardiac patient.

Adaptation, Psychological↗
PubMed1983

The type A behaviour pattern and physique.

This study examines the possibility that Type A behaviour is related to physique, and thus, is secondary to physique as a risk factor for coronary heart disease (CHD). Scores on a modified version of the 1966 Jenkins Activity Survey were correlated with a number of physical parameters. Age was found to have the highest correlation of -0.177. When the effects of age were adjusted for, only 7.1% of variation in JAS scores was explained by the body measurements used to define physique. In addition, when high and low scorers on the JAS were compared, no significant differences were found between the groups on any of the body measurements. Since this study found no significant relationship between JAS scores and physique, the results do not controvert the supposition that Type A behaviour is an independent risk factor for CHD.

Adult↗
PubMed1983

Synchrony in mother-infant interaction: a possible neurophysiological base.

The extent to which mothers and their infants can synchronize their activity levels and cycles of engagement and disengagement has been seen as fundamental to healthy affective development in the infant. Ten mothers and their infants were studied to consider the possibility of a neurophysiological base to synchronization potential. The infants' neurophysiological capacities were examined within two to three days of birth using the Brazelton Neonatal Behavioural Assessment Scale. The same infants and their mothers were assessed in their interactions after three months. The mothers' physiological responses to stimulation also were examined. Significant correlations were found between neonatal responsivity to stimuli and motor maturity, maternal stimulus screening capacity and the nature of the mother-infant interaction at three months. In particular, infants who were more socially responsive and attentive to stimuli had mothers with a greater capacity for 'screening out' redundant stimuli. Moreover, these same dyads spent more time in social engagement and had fewer cycles of disengagement. These findings, together with other studies, suggest that particular neurophysiological capacities of mothers and infants may be more conducive to the synchronization of their interactions than others. This raises the possibility that the chaotic asynchrony observed in clinically diagnosed mother-infant disturbances may have a neurophysiological base.

Acoustic Stimulation↗
PubMed1983

Effect of motilin on the opossum upper gastrointestinal tract and sphincter of Oddi.

We studied the effect of motilin on myoelectric activity of the sphincter of Oddi (SO) and upper gastrointestinal tract in conscious opposums. In 17 animals, bipolar electrodes were implanted on the gastric antrum, SO, duodenum, and jejunum. Subsequent 8-h recordings reconfirmed our previous findings that SO spike burst rate changed with interdigestive cycles of the gastrointestinal migrating myoelectric complex (MMC), becoming maximal during passage of phase III activity through the duodenum. In eight animals, peak motilin levels were shown to occur concurrently with maximal SO spike burst rate and MMC phase III activity in the duodenum. Motilin infusion (0.3 and 0.9 micrograms X kg-1 X h-1), given for 30-60 min starting 10 min after duodenal phase III, elicited premature MMC activity that originated in the stomach. Maximal SO activity occurred coincident with passage of premature phase III activity through the duodenum. Pulse intravenous doses of motilin (25-1,600 ng/kg) generally caused an immediate increase in spike burst activity in the gastric antrum, duodenum, and SO that lasted 3-5 min and was often followed by a premature MMC, usually starting in the antrum and progressing through the duodenum and jejunum. Increases in SO spike burst rate also occurred concurrent with motilin-induced, premature duodenal phase III. Motilin given at 5-60% of the duodenal MMC cycle length elicited premature MMCs at 10-60% of the cycle, but no premature MMCs were elicited by any of the motilin doses at the 5% intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Ampulla of Vater↗
PubMed1982

Evaluation of left ventricular performance in infants and children using radionuclide angiography.

Eight quantitative first-pass (FP) radionuclide angiograms were performed in six children with left ventricular (LV) dysfunction without associated LV outflow obstruction and one infant with obstructive cardiomyopathy (CM) to define regional and global LV function. All patients (3 months to 15 years) had clinical findings of congestive heart failure. Echocardiographic evaluation was performed within 24 hours of the FP study. LV ejection fraction (LVEF), regional ejection fraction index (REFI), LV wall motion perimeters, transit time, and curve analysis were evaluated. Ejection fraction by FP-RNA was compared to echo in all patients. FP-RNA derived end-diastolic and end-systolic LV perimeters were compared to corresponding contrast angiographic definition of LV wall boundaries. FP-LVEF ranged from 23-44% in 6 patients with non-obstructive CM and was 79% in 1 patient with obstructive CM. REFI revealed diffuse hypokinesis in 6 patients with nonobstructive CM, with additional apical akinesis in 1 patient. The infant with obstructive CM had hyperdynamic wall motion. These data compared favorably with echo EF and angiographic assessment of LVEF and wall motion.

Adolescent↗
PubMed1982

Some origins of the 'difficult' child: the Brazelton scale and the mother's view of her new-born's character.

Thirty-two mothers and their new-born babies were studied in order to consider, in a limited way, the manner in which a mother comes to attribute personality traits to her infant. The child's expected 'difficulty' was rated by means of a standardized inventory. In addition, a semi-structured interview was conducted with the mother, and her baby was examined by means which have been described by Brazelton. The circumstances of birth were taken from hospital records. Mothers who did not expect the child to be difficult showed a 'general flexibility' which probably related to coping ability. Babies who were seen as unlikely to be difficult had high scores on 'state control' and 'physiological response to stress'. These measures include ratings for habituation and seem to reflect an efficient means of dealing with stimuli. These infantile factors did not correlate with the maternal one, suggesting that a genetic explanation of the findings was not likely. The effect of the circumstances of birth was not strong, but medication level seemed important. The transcripts of the mothers' interviews were consistent with the view that the mother's assessment of her infant's character was not only influenced by a fine observation of the infant's behaviour but also by something like 'projective identification'. The transcripts also suggested that mechanisms which have been seen as important in the development of identity in adolescence may be operating from the first days of life.

Adolescent↗
PubMed1976

Effect of luteinizing hormone releasing hormone on plasma levels of luteinizing hormone, oestradiol and testosterone in the male dog.

An injection of luteinizing hormone releasing hormone (LH-RH) increased plasma LH and testosterone concentrations in the male dog, but no significant increase in plasma oestradiol-17beta levels was observed. Repeated injections of LH-RH produced an increase in plasma LH levels but there was a progressive decline in the response with each injection. The concentration of plasma testosterone reached a maximum within 40 min of the first injection of LH-RH and remained constant thereafter while plasma oestradiol concentration gradually increased with successive injections of LH-RH.

Animals↗