Effect of vagotomy on biliary-tract motor activity in the opossum

In this study, we evaluated the effect of truncal vagotomy in the opossum on changes in gallbladder and sphincter-of-Oddi (SO) contractile activity that occur normally during fasting and after a meal. In six animals, bipolar electrodes were implanted on the SO, gastric antrum, duodenum, and jejunum. A catheter secured in the gallbladder fundus was used to monitor gallbladder volume. After control studies, truncal vagotomy and pyloroplasty were done in each animal. Before vagotomy, the SO exhibited cyclic changes in spike-burst rate, from 2 to 5/min, that were synchronized with corresponding phases of the duodenal MMC cycle. The gallbladder exhibited partial emptying during the second half of the duodenal MMC cycle with refilling during the first half of the next cycle. By two weeks after vagotomy, the MMC-related changes in SO and gallbladder contractile activity were normal. In contrast, vagotomy retarded the increase in SO spike-burst rate and delayed as well as diminished the pronounced gallbladder emptying that normally occurs after a meal. The same effects were observed for changes in SO and gallbladder activity induced by intraduodenal infusion of Isocal. After vagotomy, the SO and gallbladder exhibited exaggerated responses to intravenous infusion of CCK-OP or motilin. We conclude that truncal vagotomy in the opossum does not affect the fasting pattern of SO and gallbladder contractile activity, but it significantly alters the normal postprandial pattern of enhanced SO spike-burst rate and pronounced gallbladder emptying. The precise mechanism(s) whereby vagotomy produces these changes remains to be determined.

Radionuclide bone imaging findings in recurrent calvarial infarction in sickle cell disease

A patient with sickle cell disease developed bi-parietal calvarial infarctions, and subsequently developed bi-frontal calvarial infarctions. The findings on [99mTc]MDP bone imaging showed decreased activity in the parietal and frontal regions during the phase of acute infarction and increased activity in the parietal region during the later healing phase. Thus the findings on radionuclide bone imaging in cortical infarcts will depend upon the stage of the condition.

Role of SecA and SecY in protein export as revealed by studies of TonA assembly into the outer membrane of Escherichia coli

The growth of secAts or secYts mutants at the restrictive temperature has been shown to inhibit the export of many outer membrane proteins. We report here that in two secAts strains the rate of incorporation of newly synthesized protein into both inner and outer membrane fractions decreased by about 70% at the restrictive temperature. The export of the outer membrane protein TonA was used as a model system in which to study the effects of SecA or SecY inactivation. pre-TonA that accumulated at the restrictive temperature was found to co-sediment with the outer membrane fraction. However, the precursor was sensitive to protease and did not float up a sucrose gradient with the membrane fractions. It was therefore concluded that pre-TonA was not integrated into the outer membrane fraction but probably accumulated in the cytoplasm. Studies on the rate of processing of pre-TonA, pulse-labelled at the restrictive temperature then chased at the permissive temperature, revealed differences between secA and secY mutants. In the secAts mutant the great majority of cytoplasmic pre-TonA was not apparently processed to the mature form, whereas in the secYts mutant significant amounts of precursors were rapidly chased into mature TonA, which appeared in the outer membrane. These results suggest that SecA and SecY may act sequentially in the export of proteins to the outer membrane. In particular these data indicate that SecA is required to maintain pre-TonA in a translocationally competent form prior to interaction with the SecY export site.

Release of a chimeric protein into the medium from Escherichia coli using the C-terminal secretion signal of haemolysin

Recently, we have identified a novel topogenic sequence at the C terminus of Escherichia coli haemolysin (HlyA) which is essential for its efficient secretion into the medium. This discovery has introduced the possibility of using this secretion system for the release of chimeric proteins from E. coli directly into the medium. We have now successfully fused this C-terminal signal to a hybrid protein containing a few residues of beta-galactosidase and the majority of the E. coli outer membrane porin OmpF lacking its own N-terminal signal sequence. We find that this chimeric protein is specifically translocated across the inner and outer membranes and is released into the medium. In addition, we have further localized the HlyA secretion signal to the final 113 amino acids of the C terminus. In fact, a specific secretion signal appears to reside at least in part within the last 27 amino acids of HlyA.

The use of Epstein-Barr virus transformation for the establishment of class II positive cord blood cells for use in analysis of maternal sera

The use of Epstein-Barr virus transformed cord blood cells to detect maternal antibodies to neonatal class II DR and DQ antigens and to allotype the reacting cells is described.

Abnormal steroid excretion in gestational trophoblastic disease complicated by ovarian theca-lutein cysts

Serum and urine steroids were examined in two subjects with trophoblastic disease accompanied by large ovarian theca-lutein cysts and compared with those from 10 patients with trophoblastic disease but without palpable cysts. In the patients without cysts normal values were obtained for serum oestradiol, progesterone, 17 alpha-hydroxyprogesterone and androstenedione, and for urinary total oestrogens, pregnanediol, pregnanetriol, and 17-oxosteroids. Nineteen urinary steroid metabolites, quantified by capillary gas-liquid chromatography, were either within reference limits or marginally raised. In several cases relatively minor increases in serum testosterone and cortisol and urinary free cortisol were observed. In contrast, the subjects with cysts showed pronounced excesses of androgen metabolites, 17 alpha-hydroxypregnenolone, pregnanediol, and pregnanetriol, and both exhibited a similar pattern of unusual additional metabolites. The profiles superficially resembled those seen in 21-hydroxylase deficiency adrenogenital syndrome, but there were important discrepancies reflecting known differences in ovarian and adrenal steroid metabolism. Chemotherapy led to decline of human chorionic gonadotrophin concentrations, regression of the cysts, and return to normal of the steroid profile. Excess steroids in the patients with cysts may have originated in the ovary rather than in the trophoblastic tissue.

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.

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.

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)

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.

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.

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.

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.