[Maternal deaths due to infections in France 2013-2015]

Over the 2013-2015 period, maternal mortality due to infections accounted for 10 % of direct maternal deaths and 13 % of indirect maternal deaths. Among the 21 deaths from infection, and compared to the last triennium, maternal deaths from genital infection doubled with 11 deaths during the 2013-2015 period. This included 6 cases of puerperal toxic shock syndrome, 4 of which due to Streptococcus A, and 5 cases of sepsis caused by intrauterine infection due to Gram-Negative Bacillus. Indirect maternal deaths due to infections from extragenital sources represented 10 deaths in this triennium, including four influenza infections and three infectious complications of an immunosuppressive state (uncontrolled HIV infection for two patients and CMV encephalitis during an immunosuppressive treatment for one patient). Of these 21 deaths by infectious causes, 6 direct maternal deaths and 9 indirect maternal deaths were considered preventable. The most common preventable factors were those related to medical management (13 times): diagnostic failure or delayed diagnosis leading to a delayed medical treatment, absence of influenza vaccination. The other contributory factors were related to the organization of healthcare (delayed transfer, lack of communication between clincians) as well as factors related to patient social vulnerability.

Prévention et prise en charge de l’infection herpétique au cours de la grossesse et de l’accouchement : recommandations pour la pratique clinique – texte des recommandations (texte court)

OBJECTIVE

Identify measures to diagnose, prevent and treat genital herpes infection during pregnancy and childbirth and neonatal infection.

METHODS

Bibliographic search from Medline, Cochrane Library databases and research of international clinical practice guidelines.

RESULTS

Genital herpes lesion is most often due to HSV2 (LE2). The risk of HSV seroconversion during pregnancy is 1 to 5% (LE2). Genital herpes ulceration during pregnancy in a woman with history of genital herpes corresponds with a recurrence. In this situation, there is no need for virologic confirmation (grade B). In case of genital lesions in a pregnant woman that do not report any genital herpes before, it is recommended to perform a virological confirmation by PCR and HSV type specific IgG (Professional consensus). In case of first episode genital herpes during pregnancy, antiviral treatment with acyclovir (200mg 5 times daily) or valacyclovir (1000mg twice daily) for 5 to 10 days is recommended (grade C). In case of recurrent herpes during pregnancy, antiviral therapy with acyclovir (200mg 5 times daily) or valacyclovir (500mg twice daily) can be administered (grade C). The risk of neonatal herpes is estimated between 25% and 44% in case of initial episode (LE2) and 1% in case of recurrence (LE3) at the time of delivery. Antiviral prophylaxis should be offered for women with first episode genital herpes or recurrent genital herpes during pregnancy from 36 weeks of gestation and until delivery (grade B). In case of a history of genital herpes without episode of recurrence during pregnancy, it is not recommended routinely offer a prophylactic treatment (professional consensus). A cesarean section should be performed if there is a suspicion of first episode genital herpes at the onset of labor (grade B), in the event of premature rupture of the membranes at term (professional consensus), or in case of first episode genital herpes less than 6 weeks before delivery (professional consensus). In case of recurrent genital herpes at the onset of labor, cesarean delivery will be all the more considered if the membranes are intact and vaginal delivery will be all the more considered in case of prolonged rupture of membranes (professional consensus). Neonatal herpes is rare and mainly due to HSV-1 (LE3). In most of the case of neonatal herpes, the mothers have no history of genital herpes (LE 3). In case of suspicion of neonatal herpes, different samples (blood and cerebrospinal fluid) for HSV PCR must be carried out to confirm the diagnosis (professional consensus). Any newborn suspected of neonatal herpes should be treated with intravenous acyclovir (60mg/kgs/day 3 times daily) (grade A) prior to the results of HSV PCR (professional consensus). The duration of the treatment depends on the clinical form (professional consensus) CONCLUSION: There is no formal evidence that it is possible to reduce the risk of neonatal herpes in genital herpes during pregnancy. However, appropriate care can reduce the symptoms associated with herpes, the risk of recurrence term and the cesarean rate performed to decrease the risk of neonatal herpes.

Forty years of achievement in French research on digestive physiology in the pig

The contribution of the research group set up by Rérat in the early 1960s in Jouy-en-Josas, and then expanded to Rennes, is summarised. As digestive processes are a major key to the nutritional status of monogastric animals, original methodologies based on advanced experimental surgery were developed in the pig to quantify the digestion and absorption yield, to know their factors of variation, and to understand their physiological and nutritional consequences. The group also extended its expertise to the control of food intake, the role of the nervous system and regulatory peptides, and several biomedical gut-related topics.

Stereotaxic atlas of the pig brain

A stereotaxic atlas of the pig brain has been established. It consists of 60 frontal and 18 sagittal drawings illustrating Nissl stained sections. A stereotaxic apparatus adapted for the Pig was used to determine the brain coordinates. Radiographic techniques were applied to verify the correct position of the central nervous structures in the apparatus. The zero horizontal plane contains the line joining the recessus preopticus and the posterior commissure (PC) images. These two landmarks were identified by ventriculography. The anterior limit of the PC is used as zero on the stereotaxic atlas. Vertical electrode trajectories implanted at a fixed depth in the brain and at different anterior and lateral levels were used to determine the lateral, vertical and height coordinates in the different planes. Then the brains were perfused and embedded to avoid major displacement of the cerebral structures. Frontal and sagittal serial sections of 100 microns were performed in two different animals. Magnified diagrams of brain sections representing the cellular architecture of the brain structures were produced, some of which are illustrated with photomicrographs. For certain areas, the limits of the nuclei were difficult to determine even when complementary electrophysiological studies were carried out. Each plate is accompanied by a list of abbreviations used to label structures on the plate, together with the terms which they represent. This work should provide a useful anatomical guide for research on the pig brain.

Measurement of gastric emptying by intragastric gamma scintigraphy

Gastric emptying is usually measured in animals and humans by dilution/sampling or external scintigraphy. These methods are either time consuming or require expensive equipment. The capacity of a miniature gamma counter positioned in the stomach to measure emptying of liquid and solid meals was evaluated. In eight conscious pigs fitted with gastric and duodenal cannulae, gastric emptying of saline (500 mL), dextrose (20%, 500 mL), porridge (300 g) and scrambled eggs (300 g), all labelled with 3.5 MBq 99mTC, was evaluated. When positioned in the antrum the probe was unable to quantify gastric emptying. In contrast, measurements of the fractional emptying of saline over 4-min periods by the probe positioned in the corpus and quantification of radioactivity in the duodenal effluent correlated closely (r = 0.88, P < 0.05). Gastric emptying (50% emptying time) of saline and both solid meals measured by the probe was not significantly different from quantification of the duodenal effluent volume. No difference was observed also for the dextrose meal but only while gastric acid secretion was suppressed by omeprazole. We conclude that an intragastric gamma counter permits measurement of gastric emptying of homogeneous meals provided meal stimulation of gastric secretion was not extensive. This was possible probably by monitoring emptying from the proximal stomach.

Proximal gastric distension modifies ingestion rate in pigs

Control of food ingestion related to proximal gastric distension has never been demonstrated in pigs. The aim of this study was to demonstrate its existence. Meal duration, food intake rate and characteristics of non-ingestion periods were evaluated during the ingestion of a 500 g meal with simultaneous balloon distension of the proximal stomach. Distensions were performed either at fixed pressure levels or at fixed volume levels. Five pressure levels and five volume levels were tested in duplicate experiments in random order and on different days in each animal. Pressures equal or above 11 mmHg increased meal duration (656 +/- 12 vs 562 +/- 30 s, 11 mmHg vs control) because of a lower rate of food intake and longer period of non-ingestion. On the contrary, irrespective of the gastric bag volume, isovolumic distensions did not alter feeding behaviour. We concluded that a short term control of food intake exists in pigs.

Influence of jejunal nutrients on transpyloric flow and pyloric resistance in pigs

The effects of small intestinal infusion of nutrients on the transpyloric flow and pyloric resistance were evaluated in anaesthetized pigs. Saline versus isocaloric solutions of dextrose, triglycerides and casein were infused into a jejunal loop during saline gastric loading. Antropyloroduodenal pressures were measured with a sleeve/side-hole manometric assembly and the transpyloric flow with an electromagnetic flowmeter probe. Fundic pressure was maintained constant. Although the overall gastric emptying rate was not affected by nutrients, the stroke volume of the transpyloric flow pulses was significantly increased as a consequence of larger peak flow (dextrose) or longer duration of flow pulses (triglycerides and casein). Pyloric resistance was reduced by all nutrients owing to a change in the temporal relationship between the onset of pyloric pressure events and flow pulses so that flow pulses occurred after pyloric pressure events. In conclusion, under controlled fundic pressure, nutrient infusions decrease pyloric resistance.

Morphometry of the small intestine in pigs with ileo-rectal anastomosis

Ileo-rectal anastomosis (IRA), which is frequently used to measure prececal digestibility in pigs, could induce some disturbances of the normal absorptive function. Our aim was to investigate the effects of different IRA surgical procedures on the main histologic characteristics of the small intestine in pigs. The 4 different IRA procedures compared to intact pigs (INT) were the following: either end to end (EE) or end to side (ES) with or without preservation of the ileocecal valve (EEV, EE, ESV, ES respectively). At 147 d after surgery, samples of the wall of the duodenum, jejunum and ileum were taken under anesthesia and histometric examinations were performed on HE- and PAS-colored sections to estimate changes mainly of mucosa and muscle layers. The values recorded for villus length, crypt depth, and whole thickness of the mucosa suggested that the EE procedures disturb the small intestine less than the ES models. A new parameter, called epithelial quotient and calculated as [(villus length/crypt depth)/mitotic index], was proposed to improve the comparisons. According to this quotient, EE procedures did not significantly affect the mucosa of the whole small intestine. An increased density of goblet cells was recorded in all operated pigs along the small intestine, but mainly in the ileum after EE-IRA. The lymphatic follicle area was reduced. These findings, which were in agreement with a reduced mitotic index in the ileum of EE-pigs, indicated a decreased effect of noxious factors on the small intestinal mucosa in IRA-pigs, especially after the EE-IRA procedure. Some atrophic or hypertrophic effects on the muscle layers were related to the absence or preservation of the ileo-cecal valve. Finally it was concluded that i) there was no major disturbance after IRA, and ii) the end to end procedure was most beneficial for the structural integrity of the small intestine.

Vagal control of pyloric resistance

Pyloric resistance is probably a major factor regulating gastric emptying of liquids, but its nervous control is unknown. The role of efferent vagal pathways in pyloric resistance was evaluated in 13 anesthetized pigs. Pyloric resistance was assessed by simultaneous recording of gastropyloroduodenal motility and transpyloric flow during gastric emptying of saline. Cervical vagotomy suppressed all antral pressure events, increased the number of pressure events localized at the pylorus, and decreased the frequency of the flow pulses (P < 0.05), without affecting either pyloric resistance or the characteristics of flow pulses. Electrical stimulation of the cervical and the thoracic vagi both decreased pyloric resistance by about 60% and increased the stroke volume of flow pulses (P < 0.05). The reduced pyloric resistance was mainly related to an alteration of the temporal relationship between flow pulses and pyloric pressure events. These results indicate that vagal efferents could provide inhibitory inputs to pyloric resistance. A reduction in pyloric resistance contributes to the increased flow rate observed during vagal stimulation.

Vagal control of transpyloric flow and pyloric resistance

Vagal control of pyloric resistance was evaluated in anesthetised pigs by recording gastropyloroduodenal motility and transpyloric flow during emptying of a liquid nonnutrient meal. Vagotomy did not modify pyloric resistance or the characteristics of the flow pulses. Electrical stimulation of the distal stumps of cervical or thoracic vagus nerves decreased pyloric resistance and triggered flow pulses of large stroke volume. This was associated with increased fundic tone and pressurization of the antrum. Phentolamine but not propranolol reduced the responses to vagal stimulation. These observations demonstrate that reduced pyloric resistance is one mechanism by which vagal activation promotes transpyloric flow.

Preliminary results of a magnetic resonance imaging (MRI) study of the pig brain placed in stereotaxic conditions

Magnetic resonance imaging (MRI) of two pig brains was realized. The animals were placed in the stereotaxic conditions currently used in experiments. To allow the positioning of the animal in the MRI instrument, landmarks were previously traced on the snout of the pig. To avoid movements, animals were deeply anesthetized. MRI were taken in frontal, horizontal and sagittal directions. Afterwards, the brains of the pigs were frozen and cut into sections, frontal for one animal and sagittal for the other. Histologic and MR images were compared. The usefulness of this technique is discussed.

Exogenous and endogenous contributions to nitrogen fluxes in the digestive tract of pigs fed a casein diet. III. Recycling of endogenous nitrogen

The aim of the present study was to measure the incorporation of infused 15N in blood fractions, urine, digesta, faeces and in the exocrine pancreatic and biliary secretions, in order to estimate the endogenous part of nitrogen in the ileal digesta and in the faeces of pigs fed a casein diet and to calculate the total endogenous nitrogen secretion as well as its recycling in the digestive tract. For 8 d 11 Large White female pigs (50.1 +/- 1.8 kg) received a continuous infusion of L-[15N]leucine via a catheter in the jugular vein. The 15N-enrichment was measured in several fractions. The 15N-level of the pancreatic juice was higher than that in the biliary secretion, TCA-blood fractions, and urine during the whole experimental period. Using the 15N-isotope dilution method it was found that casein was completely digested up to the terminal ileum and that all the nitrogen in the ileal digesta was of endogenous origin. The total endogenous secretion was estimated at approximately 11 g N/d. The reabsorption of endogenous nitrogen amounted to 79% up to the end of the small intestine and 88% over the whole digestive tract.

Exogenous and endogenous contributions to nitrogen fluxes in the digestive tract of pigs fed a casein diet. II. Ileal and faecal digestibilities and absorption of amino acids

The present work aimed at quantifying nitrogen (N) and amino acid (AA) fluxes in the digestive tract of growing pigs fed a casein diet. In this paper we report on digesta passage at the terminal ileum, on apparent balances at the ileal and faecal levels, and on nutrients appearance in the portal vein. Digesta flow-rate at the terminal ileum was maximum between 6 and 12 h after the meal. About 10% of N and 5% of total AA ingested were recovered within 24 h. AA absorption started 30 min after the meal, and was measurable until 13 to 14 h. The total AA absorbed in 24 h accounted for 128% of the AA ingested. The AA composition of ileal digesta was very different from that of casein, closely resembling that of endogenous proteins. The AA composition of faeces was very close to that of bacterial proteins. The ileal digestibilities of AA, though lower than their faecal values, were very high. This was confirmed by AA absorption balances greater than 100%. These data suggest that casein was almost totally digested by the terminal ileum, and that endogenous AA were substantially reabsorbed. These findings are supported by data on endogenous N recycling (15N), reported in a following paper.

Galanin in porcine vagal sensory nerves: immunohistochemical and immunochemical study

In this work, the presence of galanin was examined by immunohistochemistry, radioimmunoassay and high performance liquid chromatography (HPLC) in porcine nodose ganglia, mainly constituted of cell bodies from the vagal sensory neurons. Galanin-like immunoreactivity (Gal-LI) was revealed in 10 to 15% of the total cell bodies by the indirect immunofluorescent technique of Coons. For comparison, a positive staining was revealed in a few cell bodies of the submucous plexus and in fibers located in the different layers of the ileum. The extractable Gal-LI content in nodose ganglia was 7.2 +/- 0.8 pmol/g wet tissue, which represents a concentration about nine times lower than that found in the ileum. HPLC of extractable material revealed a predominant peak which coeluted with the synthetic peptide. We propose that, in pigs, galanin may play a role in the transmission of visceral information through the vagal afferences.

Exogenous and endogenous contribution to nitrogen fluxes in the digestive tract of pigs fed a casein diet. I. Contributions of nitrogen from the exocrine pancreatic secretion and the bile

The aim of the present work was to study the endogenous contribution of the exocrine pancreatic and biliary secretions to the total endogenous nitrogen production in the pig. Three growing Large White pigs weighing 45 +/- 2.5 kg were fitted with permanent fistulae in the pancreatic duct, the bile duct and the duodenum. They were adapted to a semi-synthetic casein diet for 14 d before surgery. In a 7-d post-operative period and an 8-d experimental period, they were fed the same diet. Secretion rates were recorded, total nitrogen and TCA (trichloroacetic acid) insoluble nitrogen were determined in representative pancreatic juice and bile samples. Daily pancreatic juice and bile flow rates were very similar: 1,850 and 1,820 ml, respectively. The amount of endogenous total nitrogen secreted in the intestinal lumen was 3.6 g per day: 1.9 g N through pancreatic secretion and 1.7 g N through bile secretion. Pancreatic nitrogen increased after meal intake, whilst the kinetics of nitrogen production in the bile were not affected. Throughout the experiment, the mean percentage of TCA insoluble nitrogen was 78.1% in pancreatic juice and 72.3% in bile.

Vagal gastric efferent activity and its reflex changes in conscious sheep

Electromyographical recordings from neck muscles reinnervated by the vagus nerve allowed monitoring of vagal output to the reticulo-rumen in conscious sheep. The vagus nerve was sectioned below the nodose ganglion and its central end anastomosed with the peripheral end of the spinal accessory nerve, which innervates the trapezius and mastoido-humeral muscles. Fifty-three vagal efferent units recorded were identified and classified into seven distinguishable types on the basis of their temporal relationship with gastric movements. With respect to their patterns of discharge during the primary cycles type I to type V units were similar to units of the corresponding types described by Iggo & Leek (1967a) in anaesthetized sheep. Evidence for the hypothesis that each type of gastric unit innervates a distinct region of the reticulo-rumen is strongest for types I and IV. Type I units which exhibited a bimodal pattern of discharge closely associated with reticular motility, are presumed to innervate the reticulum. Some of them, so-called Ib because of their second burst with a long tail and their activity during the secondary cycles, are considered to activate the zone of attachment of the reticulum to the rumen. Type IV units which were active during the ruminal contractions of both primary and secondary cycles are considered to innervate the dorsal rumen. Discharges in these gastric units were observed when gastric motility was partially or totally abolished after administering autonomic blocking drugs for each unit tested (n = 25). They consisted of (i) a shortening of intervals between the onset of two successive bursts, and (ii) an increase in the duration of discharge and the number of potentials in the efferent units. As the abolition of gastric motility led to a decrease of gastric afferent input, these results suggest that the gastric centres are under a permanent inhibitory influence from the afferent drive.

A stereotaxic apparatus for the study of the central nervous structures in the pig

An apparatus has been developed derived from the Horsley-Clarke principle. Specific requirement was to use large breeds of pigs from weaning to adult age (5 to 120 kg). The pig auditory canals are oblique; the measurement of the corresponding angles was achieved by means of two interconnected barrels, used afterwards to fix the ear-bars. The wide variability of the skull morphology led to the systematic use of ventriculography with a liquid of contrast. Consequently the pieces allowing the head fixation in the stereotaxic apparatus were designed to avoid any shadow on the brain area. As it was not always possible to localize the commissura anterior, the anterior border of the recessus preopticus was chosen to determine, together with the commissura posterior, the reference horizontal plane. The antero-posterior coordinates were counted from the anterior border of the commissura posterior. The methodology, which has been tested in a wide range of pigs, is discussed in relation with the methods used for other animal species.

Associative effects between two fibre sources on ileal and overall digestibilities of amino acids, energy and cell-wall components in growing pigs

1. The associative effects of two fibre sources on ileal and overall digestibility of amino acids, energy and cell-wall components were studied by comparing wheat bran and soya-bean hulls in semi-purified diets given to growing pigs. 2. Castrated male pigs were prepared with ileo-rectal anastomosis to measure ileal digestibility, and overall digestibility was measured in pigs without anastomosis. 3. The three diets contained 190 g total fibre/kg dry matter (DM), derived from each fibre source or from a mixture of both fibre sources, so that each source provided half the amount of total fibre, and 170 g crude protein (nitrogen x 6.25)/kg DM by additions of casein. 4. The effects of fibre sources on the ileal digestibility of amino acids were additive for most amino acids; the only significant interactions were found for threonine, methionine and aspartic acid. In contrast with ileal digestibility, systematic negative interactions between fibre sources on overall digestibility of amino acids were noted. 5. There was no interaction between fibre sources in their effects on the digestibility of energy or of cell-wall components, irrespective of the site of digestion. The digestibility values were higher with soya-bean hulls than with wheat bran, especially at the faecal level. 6. It is concluded that ileal digestibility of amino acids provides a better estimate of amino acid availability, as ileal measurements allow a better discrimination between diets than faecal measurements when distinct fibre sources are used alone or in combination at the same total fibre content. In contrast, for energy, the measurement of digestibility at both faecal and ileal levels permits the estimation of the partition of available nutrients between the small and large intestines.

Variations of plasma immunoreactive motilin, pancreatic polypeptide, gastrin and somatostatin along the duodenal motility cycle in the pig

The peripheral plasma concentrations of immunoreactive motilin, pancreatic polypeptide (PP), somatostatin and gastrin were measured in 7 pigs fasted to 24 h and subsequently fed a standard meal. Plasma motilin peaked during the last part of phase II activity of the migrating myoelectric complex (MMC) sequence (25.2 +/- 2.3 pM), the lowest value being recorded during phase I (10.6 +/- 1.5 pM) after a 24 h fast. Plasma motilin remained at a low level during the digestive pattern of duodenal activity, no fluctuation occurring when the first postprandial MMC recurred. At variance analysis, gastrin and PP were not released phasically with MMC in the fasting state, while at autocovariance both peptides tended to fluctuate during the MMC sequence with positive and negative peaks at regular intervals along MMC cycles. No variation of plasma somatostatin was observed in the fasting animals. These findings argue against a major role of circulating PP, gastrin and somatostatin-like components in the control of fasted and post absorptive duodenal motility in pigs while the role of motilin remains equivocal.

Muscular hyperalgesia and hypoalgesia after stimulation of the ureter in rats

Vocalization electric thresholds were measured bilaterally in muscles of the lower back and in the tail after electrical stimulation of the left ureter in rats implanted with electrodes. 'Painful' stimulation immediately produced a hyperalgesia lasting about half an hour in the left lower back muscles and tail, followed by a 10 min hypoalgesia limited to the back muscles. No modification or only a delayed hypoalgesia appeared in the right muscle. Strong but 'non-painful' stimulation produced no effect or gave rise to an immediate hypoalgesia in the left muscle. Weak non-painful stimulation produced a delayed hypoalgesia in the tail.

Biliary and pancreatic secretory component of the migrating myoelectric complex in the pig. Effect on intraduodenal pH

The aim of the present study in the pig was to describe the biliary and pancreatic secretory component of the migrating myoelectric complex (MMC) during the interdigestive period and after feeding, and to examine the effects of the extracorporal diversion of biliary or pancreatic secretions on the MMC and on the cyclical variation of intraduodenal pH. In a first trial six pigs (50.6 +/- 1.6 kg) were fitted with a permanent catheter in the common bile duct (3 pigs) or in the pancreatic duct (3 pigs) to control the flow of these secretions. They also had a duodenal catheter to return the secretions, and antral and duodenal electrodes for simultaneous recording of motility in fasting conditions. In a second trial ten pigs (50.8 +/- 1.5 kg) underwent a similar surgical preparation (5 bile duct and 5 pancreatic duct fistulations). They had, in addition, a duodenal T-shaped cannula (19 cm distal to the pylorus) allowing continuous intraluminal pH recording parallel to the motility recording. Experiments included 4 situations: secretions returned under fed or fasted conditions; by-passed secretions in fed or fasted pigs. The flow of bile and pancreatic juice was very high during irregular spiking activity phases (ISA), peaking at the beginning of regular spiking activity phases (RSA); it was minimal during quiescent phases. The duration of the duodenal MMC and of its 3 constitutive phases was not modified by total extracorporal diversion of bile or pancreatic secretion either in the fed or fasted state. During the interdigestive period the pH was significantly reduced under bile diversion (quiescence: 6.17 vs 7.15; ISA: 4.91 vs 5.94; RSA: 5.40 vs 6.52) as well as under pancreatic juice diversion (quiescence: 5.56 vs 7.18; ISA: 4.21 vs 5.97; RSA: 5.14 vs 6.72). In fed pigs only bile diversion resulted in a small acidification during the postprandial pattern (5.07 vs 5.44) and the consecutive MMC cycles (quiescence: 5.81 vs 6.61; ISA: 4.66 vs 4.92; RSA: 5.11 vs 5.78). Nevertheless the periodicity of pH variation along the MMC cycle was unaffected in bile or pancreatic juice-deprived animals. It is concluded that a true biliary and pancreatic secretory component of MMC exists in the pig, and that these 2 secretions strongly contribute to the neutralization of the duodenal contents. However, the major determinant of the cyclical variation of the intraduodenal pH appears to be the periodicity of the acid gastric outflow.

Contribution of bile and pancreatic juice to the control of pH in the pig duodenum

To evaluate the respective contributions of biliary and pancreatic secretions in the formation of intraduodenal pH, 10 pigs were chronically fistulated in either the common bile duct (5 pigs) or the pancreatic duct (5 pigs). They were all fitted with a permanent catheter into the duodenum for the continuous return of secretion and with a duodenal T-cannula allowing the introduction of a combined glass electrode. pH was recorded over 8-hour periods in fed or fasted pigs in which both secretions were returned or in which either the bile or the pancreatic juice was not restituted. In fed pigs with secretions normally flowing into the duodenum, the pH fluctuated between 4 and 6 during 57% of the recording time; it exceeded 6 during 29% of this period. The rest of the time, it remained between 2 and 4. Bile deprivation did not change the duration of the 4 less than pH less than 6 and 2 less than pH less than 4 ranges, although a slight decrease of the pH greater than 6 time-course was recorded. Deprivation of pancreatic secretion did not induce significant variations of the pH pattern. In fasted pigs with restituted biliary and pancreatic secretions, a pH greater than 6 was recorded for 70% of the 8-hour period. The pH was lower in short periods: 19% (4 less than pH less than 6), 8% (2 less than pH less than 4) and less than 1% (pH less than 2) of the time.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreatic size and enzyme contents after vagal deafferentation in jejunectomised pigs under free or restricted feeding

A factorial experiment was designed to test under different feeding levels the effects of the surgical deprivation of sensory afferences (deafferentation) arising from the gastrointestinal tract, including the intestinal chemosensitivity, on the jejunectomised pig used as a model. Within 28 days, the limited jejunectomy failed to affect the pancreas and the enzyme activities were not affected by the feeding level (within the limit of 70% of ad libitum). It was shown that the deafferentation induced significant reductions in the pancreatic tissue mass and in the various enzyme activities, thus suggesting the possible importance of intestinal sensibility for the pancreas.

[Development of cecal microbial flora following surgical isolation of the large intestine in swine]

An ileo-rectal anastomosis was created in growing pigs. The caecum and colon were left in place and their contents slowly emptied through a cannula located in the distal colon; accordingly, no food arrived in this caeco-colic compartment. Animals were slaughtered 14 to 54 days after the surgical operation. Using a quantitative differential analysis technique, the large intestine microflora were studied upon operation and at slaughter. It was observed that the number of strictly anaerobic bacteria did not vary or only slightly increased according to cell population counts. The most marked variations involved disappearance of the Lactobacillus population in all animals and disappearance of some morphological types of bacteria found in the dominant flora at the beginning of the experiment.

Proteins in the digesta of the pig: amino acid composition of endogenous, bacterial and fecal fractions

When studying digestibility, the respective parts of the exogenous, endogenous and bacterial fractions in the digesta or feces must be measured. The proportions of proteins from different sources may be estimated by comparing their amino acid composition with those of reference sources. This study describes the composition of endogenous and microbial proteins, i.e. meconium of piglet small intestine and colon, axenic piglet feces, bacteria isolated in the feces of pigs receiving a standard (cereal-based) or a purified diet, and pure culture of Escherichia coli. The composition of monoxenic piglet feces and of feces of conventional pigs fed the two types of diets have also been studied. The data on 17 amino acids were used to make overall comparisons of compositions, using the method of X2 distances and factorial correspondance analysis. The composition of exclusively endogenous products differed somewhat from that of samples (mucus, mucosa) usually considered as representative of that fraction. In conventional pigs, the major part of fecal proteins was composed of bacterial protein. Accurate estimation of these was difficult: diaminopimelic acid assay gave an estimate of 65% bacterial protein, while in the same experimental conditions X2 distance gave an estimate of 90%.

Comparative assessment of secretin and motilin responses to graded duodenal acidification in anaesthetised pigs

The effects of graded duodenal acidification on plasma concentration of immunoreactive secretin, and motilin in portal vein (PV) and carotid artery (CA) were investigated in 6 anaesthetised pigs in which the proximal duodenum was excluded and sequentially irrigated with isotonic saline (pH 7.0) and with hydrochloric acid (HCl) delivered at successive rates of 2, 8 and 40 mM H+/40 min (pH of 2.8, 1.9 and 1.0, respectively) under a constant flow of 10 ml/min. The release of secretin was first observed at pH 1.9 (from basal 4.2 +/- 0.3 to a peak of 26.6 +/- 9.8 pM in PV and from 3.4 +/- 0.3 to 6.8 +/- 0.9 pM in CA) and further increased at pH 1.0 (peaks of 60.9 +/- 16.3 in PV and 16.8 +/- 2.6 pM in CA). In contrast, only the highest HCl concentration (pH of effluent: 1.0) induced significant increases of plasma motilin (PV: peak of 25.2 +/- 4.9 for basal 13.3 +/- 1.1 pM, CA: 14.3 +/- 2.4 for basal 10.5 +/- 0.6 pM). A sharp decrease of the plasma secretin and motilin concentration was observed when the venous drainage of the duodenal segment was occluded, followed by a rapid increase when the clamp was released. In the present experimental conditions, duodenal motilin-producing sites were less sensitive to graded luminal acidification than secretin cells. Thus, the release of duodenal motilin in response to variations of luminal pH may be expected to occur primarily from the most proximal part of the duodenum in physiological conditions.