Interstitial cells of Cajal in dysmotility in intestinal ischemia and reperfusion injury in rats

BACKGROUND: Intestinal ischemia and reperfusion (I/R) injury is an obligatory occurrence in small bowel transplantation. I/R may impair the normal gastrointestinal motility. Interstitial cells of Cajal (ICC) are known as pacemaker cells in the gastrointestinal tract. The aim of this study was to assess the role of ICC in the gastrointestinal motility in a rat model of I/R injury. MATERIALS AND METHODS: Wistar rats were subjected to 30- or 80-min intestinal ischemia by occluding the mesenteric vessels followed by reperfusion. Small intestinal segments were resected at 12 h or 4 days. The spontaneous mechanical activity was evaluated by organ bath technique. Immunopositivity of c-Kit and PGP9.5 at the level of the myenteric plexus was evaluated as markers of ICC and enteric nerves, respectively. RESULTS: In the bowel segment with 80-min ischemia followed by 12-h reperfusion, muscles showed a 25% reduction (P < 0.05) in the frequency of contractions compared to that with 30-min ischemia followed by 12-h reperfusion, whereas amplitude of contractions was not significantly different. This change was associated with a 70% decrease (P < 0.01) of c-Kit immunopositivity. These changes of intestinal motility pattern and distribution of c-Kit-positive cells were both recovered from 80-min ischemia followed by 4 days reperfusion. In contrast, the immunopositivity of PGP9.5 was not affected in any I/R injury group. CONCLUSIONS: Transient functional changes in ICC were induced by prolonged I/R injury but they recovered after 4 days, suggesting a central role of ICC in both disrupting and restoring the normal gastrointestinal motility in I/R injury.     

Interstitial cells of Cajal as precursors of gastrointestinal stromal tumors

Interstitial cells of Cajal (ICC) are implicated in the regulation of gut peristalsis and are immunostained by antibodies against Kit (CD117), a tyrosine kinase receptor. Most gastrointestinal mesenchymal tumors (GIMTs) are of uncertain histogenesis, although many are CD34-positive. CD34 was found to colocalize with vimentin (Vim) and the Kit-positive networks of cells within and around neural plexi, indicating that ICC can be Vim- and CD34-positive. ICCs appear to be the only Kit+CD34+Vim+ cell in the gut. Formalin-fixed, paraffin-embedded tissues from 43 GIMTs were immunostained for Kit, CD34, Vim, PGP 9.5 (PGP, a neural marker), muscle-specific actin (MSA), and other markers including desmin (Des). Eight tumors were myoid (MSA+Des+Vim-Kit-CD34-), and one was a schwannoma (PGP+S100+Vim+Kit-CD34-), but 34 tumors were of uncertain histogenesis (gastrointestinal stromal tumors, GIST), exhibiting neither a complete myoid nor a schwannian immunophenotype. All 34 were Vim+, and 33/34 were either Kit (n = 30) or CD34 (n = 23) immunoreactive. Of these 34 GIST, 24 were negative for all myoid and neural markers, 6 were PGP+S100-, and 4 were MSA+Des-. The Kit+CD34+Vim+ immunophenotype of GIST suggests that they originate from, or have differentiated into, ICC-like cells; the term ICC tumor (ICCT) is suggested. Kit is a more sensitive marker than CD34 for ICCT, but both are required in tumor identification. All clinically malignant GISTs were pathologically malignant (size, mitoses) but also showed loss of either CD34 or Kit. "Blind" examination of electron micrographs in 10 tumors showed them to be heterogeneous. Some had features seen in normal ICC, but cells could not be positively identified as being adult ICC. GIMT may therefore be classifiable into those with pure myoid, schwannian (or neural) differentiation, but the majority are of ICC origin or show ICC differentiation immunophenotypically (ICCT).     

Localization of protein gene product 9.5 immunoreactivity in derivatives of the human Wolffian duct and in prostate cancer

BACKGROUND: Protein gene product 9.5 (PGP 9.5) has been considered to be a neuronal marker, but it is also present in extraneuronal tissues, e.g., the human mammary gland and rat epididymis. Its presence and distribution in the developing and adult male human genital tract have been unknown. METHODS: Immunohistochemical reactions were performed on human embryonic and postnatal specimens of the male genital tract, using commercial monoclonal and polyclonal antibodies. RESULTS: PGP 9.5 immunoreactivity was found in the Wolffian duct of human embryos (55-85 mm crown-rump length). Strong reactivity was observed in mesonephric tubular cells and at the apical rim of Wolffian duct cells. Owing to their PGP 9.5 immunoreactivity, these cells could also be identified on the surface of the embryonic verumontanum, extending from the orifices of the Wolffian duct to a small stretch of the urogenital sinus. There they contrasted sharply against non-Wolffian cells. In the adult human genital tract, PGP 9.5 immunoreactive material was present in the supranuclear portion of some epithelial cells of the epididymal efferent ductules, in isolated cells of the ejaculatory ducts, and in prostate cancer specimens. In the ejaculatory ducts, the PGP 9.5-immunoreactive cells were free of immunoreactivity for semenogelin, the major secretory product of the ejaculatory-vesicular-ampullary complex, and they also lacked chromogranin A-immunoreactivity. In prostate cancer specimens, PGP 9.5 immunoreactivity was never observed in secretory cells (immunoreactive for prostate-specific antigen), but was restricted to neuroendocrine cells, where it occurred either alone or coexpressed with chromogranin A-immunoreactivity. CONCLUSIONS: PGP 9.5-immunoreactivity is prenatally distributed in the Wolffian duct and its derivations; postnatally, it is restricted to a few cells derived from the initial and terminal segment of the Wolffian duct, and to neuroendocrine cells in prostate cancer specimens.     

The role of amniotic fluid in fetal nutrition

The contribution of amniotic fluid to fetal growth and gastrointestinal tract development was studied in a rabbit model. In the fetal rabbit, at 23 days gestation, 3 conditions were surgically produced: (1) prevention of swallowing of amniotic fluid by esophageal ligation (n = 8); (2) esophageal ligation but insertion of an esophageal cannula distally to allow continuous infusion into the stomach of bovine amniotic fluid to mimic fetal swallowing (n = 7); and (3) sham operation (n = 7). Fetuses were delivered by Caesarean section at 28 days gestation. Esophageal ligation resulted in significant reductions of birth weight and crown-rump length and a trend to decreased liver weight when compared to sham operated controls. Additionally, marked reductions in gastric and intestinal tissue weight and gastric acidity were found following esophageal ligation. These reductions in both somatic and gastrointestinal tract growth and gastric function were reversed by infusion of amniotic fluid intragastrically. We conclude that amniotic fluid provides 10% to 14% of the nutritional requirements of the normal fetus, and that amniotic fluid contains a potent and as yet undefined gastrointestinal tract trophic factor.     

Ontogeny of fetal rabbit upper gastrointestinal motility.

BACKGROUND: The gastrointestinal (GI) tract performs the digestion, propulsion, and absorption of nutrients both pre- and postnatally, although little is known about the development of fetal motility. We evaluated the development of GI motility using a novel fetal rabbit model. METHODS: Nine pregnant rabbits were obtained and three litters were studied at day 24 (n = 24), 27 (n = 29), and 30 (n = 24) of their 31-day gestation. Under ultrasound guidance fetal position was identified, a spinal needle was percutaneously inserted into each fetal stomach, and fluorescein, labeled with color-coded microspheres, was injected. Two hours later, fetuses were delivered and weighed, and the small intestine was harvested. The absolute length of fluorescein traveled was measured by ultraviolet light optical density and the percentage motility was calculated by dividing the absolute length of fluorescein traveled by the total small intestinal length. RESULTS: All injected fetuses survived. The length of fluorescein traveled significantly increased from day 24 (8.1 +/- 2.1 cm) to day 27 (18.8 +/- 4.6 cm) and 30 (22.6 +/- 5.2 cm). The length of fluorescein traveled significantly correlated with body weight on day 27 and 30. Calculated percentage motility significantly increased from day 24 to 30. However, percentage motility showed no correlation with fetal weight. CONCLUSIONS: This study describes a novel rabbit model for the assessment of in vivo fetal GI motility. Motility matured during the last third of gestation when assessed by the absolute length of fluorescein travel and the percentage motility. These results confirm that late-gestation fetuses have developed sufficient motility to propel potential nutrients, drugs, or gene therapy vectors to the small intestinal absorptive surface area.     

Marked morphological differences in the myenteric plexus between the mesenteric and antimesenteric sides of small bowel in premature infants

BACKGROUND: The gastrointestinal tract appears morphologically prepared for oral feeding by the end of the second trimester, but many of the physiological processes required for efficient enteral nutrition are not developed fully until 33 to 34 weeks' gestation. Myenteric plexus is well recognized as an important regulator of peristaltic activity. Whole-mount preparation technique produces a 3-dimensional picture to better show the neuronal networks branching and interconnections. The aim of this study was to investigate neurone density and morphology of the myenteric plexus in premature infants using whole-mount technique. METHODS: Full-thickness small and large bowel specimens were collected at autopsy from 6 premature babies (gestational age, 26 to 32 weeks) who died without evidence of gastrointestinal disease. Whole-mount preparation of the myenteric plexus was made and stained with NADPH-diaphorase and Acetylcholinesterase (AChE) histochemistry. The stained myenteric network was measured with a computer image analysis system. Controls included 4 full-term babies who died of nongastrointestinal disease. RESULTS: In premature infants there were striking differences in neuronal density of myenteric plexus in the mesenteric and antimesenteric border of small bowel. The differences in neuronal density in mesenteric and antimesenteric border of small bowel gradually became less striking as the gestation progressed with no differences evident at gestational age 32 weeks. CONCLUSIONS: This study shows for the first time that the neurone density of myenteric plexus is significantly higher in the mesenteric border of the small bowel compared with antimesenteric border in premature infants. The marked morphological differences observed in neurone density in the small bowel of premature infants may contribute to immature small bowel activity.     

Fetal esophageal transplantation in rats: a treatment option for long-gap esophageal atresia

PURPOSE: The aim of this study is to determine if fetal esophageal transplantation can create viable esophageal tissue that may be used for treating long gap esophageal atresia. METHODS: Fetuses of gestational age 19 to 20 days were obtained by hysterotomy of pregnant 15-week-old Lewis rats. A 10-mm long segment of esophagus was obtained from each fetus by thoracolaparotomy and transplanted by wrapping it in a pouch created in the distal omentum of a 5-week-old Lewis rat (syngeneic transplantation: n = 15). Transplanted fetal esophageal grafts were harvested 10 days post-transplantation and fixed in 10% formalin and embedded in paraffin. H&E was used for histological examination, and PGP 9.5 (a neuronal antibody) was used for immunohistochemistry. Esophageal segments obtained from 10-day-old Lewis rats were used as controls. RESULTS: Thirteen of 15 (87%) grafts were transplanted successfully. The successfully transplanted graft could be mobilized to the thoracic cavity without tension or compromising of vascularity, because of the long omental pedicle. H&E staining and PGP 9.5 immunohistochemistry showed normal esophageal structure with intact esophageal nervous system, comparable with control specimens. CONCLUSIONS: Fetal esophageal transplantation produces viable esophageal tissue that may find application for treating long gap esophageal atresia providing rejection can be controlled adequately.     

Sympathetic reinnervation of rat kidney grafts

BACKGROUND: Reinnervation occurs in many transplanted tissues and organs. Sympathetic reinnervation in rat kidney grafts was investigated. METHODS: Rats were syngeneically transplanted with a kidney and bilaterally nephrectomized. Reinnervation was assessed by immunohistochemical staining for neuron-specific protein gene product 9.5 (PGP 9.5) and by tissue norepinephrine measurements in grafts removed 1.5 (n=6), 3 (n=7), 6 (n=8), and 9 (n=7) months after transplantation. RESULTS: PGP 9.5-positive neural structures were significantly reduced in grafts removed 1.5 and 3 months after transplantation compared with native kidneys with slightly increased numbers at 6 and 9 months after transplantation. Median transplant norepinephrine concentrations remained at approximately 3% compared with native kidneys until 9 months after transplantation. CONCLUSIONS: In transplanted rat kidneys, some reinnervation occurs in the hilum within 9 months after transplantation. This is not accompanied by a significant recovery of norepinephrine concentration in renal tissue indicating persistent sympathetic denervation.     

Distribution of neuropeptide Y-containing nerves in the neurogenic and non-neurogenic detrusor

OBJECTIVE: To evaluate the role of neuropeptide Y in the detrusor of patients with neurogenic detrusor overactivity (NDO), as it has an important role in the neural regulation of the lower urinary tract by exerting differential effects on the release of cholinergic and adrenergic transmitters via autoinhibition and heterosynaptic interactions. MATERIALS AND METHODS: Detrusor biopsies were obtained from 38 patients; 31 had video-urodynamically verified NDO, caused by meningomyelocele in 17 or spinal cord injury in 14. Seven had stress urinary incontinence (SUI) and this group served as a control. All specimens were fixed, paraffin wax-embedded, sectioned and stained with a monoclonal antibody against neuropeptide Y and a general nerve marker protein-gene-product 9.5 (PGP 9.5). The number of PGP 9.5- and neuropeptide Y-containing nerves was quantified by a standardized evaluation using image-analysis software. RESULTS: The median (range) number of neuropeptide Y-containing nerves in the neurogenic detrusor, at 0.273 (0.126-0.639) per muscle cell nucleus (MCN), was significantly lower (P = 0.014) than that in patients with SUI, at 0.383 (0.267-0.728). In the neurogenic detrusor the number of PGP 9.5-positive nerves, at 0.278 (0.054-0.641)/MCN was also lower (P = 0.111) than in patients with SUI, at 0.368 (0.258-0.497). The ratio of neuropeptide Y to PGP 9.5 counts per biopsy did not differ between the groups (P = 0.628). CONCLUSIONS: The number of PGP 9.5-positive nerves was not significantly and the number of neuropeptide Y-containing nerves was significantly reduced in patients with NDO. This may have been caused by transynaptic nerve degeneration of the detrusor, as described by in patients with spinal cord injury. As neuropeptide Y inhibits the contractile response of the detrusor the reduction of neuropeptide Y-containing nerves may play a role in the development and persistence of DO.     

Intestinal neuronal dysplasia-like pathology in Ncx/Hox11L.1 gene-deficient mice

BACKGROUND/PURPOSE: Ncx/Hox11L.1-deficient (Ncx-/-) mice specifically created by the authors had mega-ileo-ceco-colon (mega-ICC) with a caliber change in the proximal colon. The authors studied the nerve distribution in the bowel of these Ncx-/- mice to determine the cause of their bowel dysmotility. METHODS: Four-week-old Ncx-/- mice (n = 10; 5 with mega-ICC, 5 without mega-ICC) were killed and the bowel harvested. Half of each specimen was snap frozen for AchE and NADPH-diaphorase histochemistry, and the other half were fixed with 10% formalin for H&E staining and immunohistochemistry using PGP9.5 antibody (a marker for neurons), C-kit antibody (a marker for intestinal pacemaker cells), and stem cell factor antibody (a marker for C-kit ligand). Age-matched wild-type normal mice (n = 5) served as controls. RESULTS: In the ileum, cecum, and proximal colon from all Ncx-/- mice (irrespective of the association of mega-ICC), typical findings of human intestinal neuronal dysplasia (IND) ie, obvious hyperganglionosis in neuronal plexuses on PGP9.5 immunohistochemistry, ectopic ganglia in the mucosal and muscular layers on AchE histochemistry, and ghostlike ganglia on NADPH-diaphorase histochemistry were found. Likewise, in normal caliber distal colon from these mice, the distribution of ganglion cells, C-kit, and stem cell factor was normal. In control specimens, there was no ectopic ganglia or hyperganglionosis. CONCLUSIONS: These findings suggest that the Ncx/Hox11L.1 gene is required for the proper innervation of the enteric nervous system in mice, and our deficient strain may be useful as a model for studying IND in humans.     

Differences in gut integrity following abdominal surgery according to the magnitude of the surgical stress

BACKGROUND: An increase in serum diamine oxidase (DAO) activity reflects intestinal mucosal damage. This was used to estimate the effect of surgical stress after elective abdominal surgery on gut integrity. METHODS: Patients with gastrointestinal tract cancers were placed in either group T (transthoracic esophagectomy for esophageal cancer, n = 9) or group L (laparotomy, n = 10). The serum DAO activity was measured pre-operatively, and on postoperative days 1, 3, and 8. RESULTS: Transthoracic esophagectomy was associated with a more extensive stress than the operations in group L, as measured by the intra-operative blood loss, the amount of blood transfused, and the operative time (P = 0.007, P = 0.0002, P = 0.0011, respectively). Following surgery, the serum DAO activity was decreased markedly in all patients in group T. In contrast, the activity was unchanged in group L (P = 0.04). CONCLUSIONS: The severity of the surgical insult plays a significant role in the decrease in serum DAO activity. These results suggest that surgical stress influences gut integrity following elective abdominal surgery.     

The influence of gestational age and mode of delivery on infants with gastroschisis.

BACKGROUND/PURPOSE: It has been proposed that preterm and prelabor cesarean section may improve the outcome of infants with gastroschisis. The purpose of this study is to examine the impact of gestation and delivery method on infants with gastroschisis. METHODS: The medical records of 60 infants with gastroschisis treated at a tertiary care center from 1985 through 1995 were reviewed retrospectively. The gestational age, the mode of delivery, the type of operative repair, and the length of hospital stay were recorded for each patient. RESULTS: Infants born vaginally were more likely to require silo stage repair than those delivered by cesarean section (21 of 29 v. 11 of 31, P<.01). Infants born vaginally also had longer hospital stay than those delivered by cesarean section (53 v. 39 days, P = .19). Infants born before 33 weeks' of gestation stayed longer in the hospital than those born after 33 weeks. After 33 weeks' gestation, infants had similar hospital stay regardless of the gestational age. CONCLUSIONS: Cesarean section delivery was beneficial for infants with gastroschisis. Preterm delivery did not shorten the length of hospital stay. The role of elective cesarean section delivery at term should be considered for infants with gastroschisis diagnosed antenatally.     

Parallel changes in bladder suburothelial vanilloid receptor TRPV1 and pan-neuronal marker PGP9.5 immunoreactivity in patients with neurogenic detrusor overactivity after intravesical resiniferatoxin treatment

OBJECTIVE: To compare PGP9.5 and transient receptor potential vanilloid receptor (TRPV1) suburothelial immunoreactivity between controls and patients with spinal neurogenic detrusor overactivity (NDO) before and after treatment with intravesical resiniferatoxin, as suburothelial PGP9.5-staining nerve fibres decrease in patients with spinal NDO who respond to intravesical capsaicin, and TRPV1 is present on these suburothelial nerve fibres in normal and overactive human urinary bladder. PATIENTS AND METHODS: Patients with refractory NDO were enrolled in a prospective, randomized, parallel-group, double-blind, placebo-controlled trial using escalating doses of resiniferatoxin to a maximum of 1 micro mol/L. Flexible cystoscopic bladder biopsies obtained at baseline, 4 weeks after each instillation and at the time of maximum clinical response were compared with biopsies taken from control subjects. Frozen sections were incubated with rabbit antibodies to TRPV1 and PGP9.5, and assessed using standard immunohistochemical methods. PGP9.5 nerve density was analysed using a nerve-counting graticule by an observer unaware of sample origin. Another two independent observers unaware of each other's results used a random grading scale to evaluate TRPV1 nerve fibre density and intensity. The immunohistochemistry results were compared with histology findings (haematoxylin-eosin), and the Mann-Whitney test used to assess any differences (P < 0.05 significant) and the Pearson test for correlation. RESULTS: There were eight controls and 20 patients with spinal NDO, 14 (five clinical responders and nine not) who received the maximum dose of resiniferatoxin. There were more PGP9.5 and TRPV1 nerve fibres in patients with NDO than in controls (P = 0.007 and 0.002, respectively). Immunoreactivity before resiniferatoxin was similar in both groups for both PGP9.5 and TRPV1. In responders there were fewer PGP9.5 and TRPV1-positive fibres after treatment (P = 0.008 for each) but no change in those not responding. Changes after treatment for TRPV1 correlated well with those for PGP9.5 (r = 0.88, P < 0.001). CONCLUSIONS: The decrease of PGP9.5 and TRPV1 immunoreactive nerve fibres in responders to resiniferatoxin (to levels in control tissues) suggests that the increased numbers of nerve fibres in patients with NDO are mainly of sensory origin and express TRPV1. As baseline nerve fibre values were similar in responders and nonresponders, an additional factor may account for the difference in treatment outcome.     

Immunohistochemical studies on the distribution of nerve fibers in the human prostate with special reference to the anterior fibromuscular stroma

BACKGROUND: Although the anterior fibromuscular stroma (AFMS) comprises up to one third of the total bulk of the prostate, its physiological function remains unknown. We recently reported the possible contribution of the AFMS to micturition. The aim of this study is to reveal the differences in the distribution of innervation between the AFMS and the other regions of the prostate. METHODS: We performed immunohistochemical stainings using antibodies such as protein gene product (PGP) 9.5, tyrosine hydroxylase(TH), neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP). Morphometric analysis was made to examine the density of peripheral nerve fibers containing PGP 9.5, TH, NPY, and VIP by using a computer-assisted imaging system. RESULTS: The number of PGP 9.5-immunoreactive (IR) nerve fibers and the smooth muscle in the AFMS decreased from the base to the apex of the prostate. TH-IR nerve fibers were more abundant in the AFMS than in the transition zone. NPY- and VIP-IR nerve fibers were less numerous in the AFMS than in the peripheral zone. CONCLUSIONS: This study is the first to demonstrate that the AFMS has peculiar neuronal innervation. We observed significantly different innervation in the AFMS compared with the other regions of the prostate.     

Morphological basis for back pain: the demonstration of nerve fibers and neuropeptides in the lumbar facet joint capsule but not in ligamentum flavum.

The innervation of lumbar facet capsule and ligamentum flavum was investigated using antisera to a general neuronal marker protein gene product (PGP) 9.5 and to peptide markers of sensory nerves (calcitonin gene-related peptide [CGRP] and substance P) and autonomic nerves (vasoactive intestinal polypeptide [VIP] and C-flanking peptide of neuropeptide Y [CPON]). In the facet capsule (n = 14), PGP 9.5 and CGRP-immunoreactive nerves occurred in 12 and five specimens, respectively, both around blood vessels and as free fibers in the stroma. Free fibers immunoreactive for substance P or VIP were noted in three and five specimens, whereas in nine specimens there were CPON-immunoreactive nerves located perivascularly. There was no immunoreactivity in the ligamentum flavum. This study provides further evidence that the facet capsule but not the ligamentum flavum has substantial innervation by sensory and autonomic nerve fibers and has a structural basis for pain perception.     

Maturation of insulin response to glucose during human fetal and neonatal development. Studies with perifusion of pancreatic isletlike cell clusters

The insulin release in response to glucose was studied in perifused isletlike cell clusters (ICCs) obtained from human fetal or neonatal pancreases at various stages of development: 12-15 gestational wk (n = 7), 17-20 wk (n = 13), 22.5 wk (n = 2, 1 diabetic pregnancy), and 26-44 wk (n = 6, postnatal samples). The ICCs were stimulated with 20 mM glucose and subsequently with 10 mM theophylline plus 20 mM glucose as a viability test. Insulin release increased to a detectable level (greater than 0.1 pg.ICC-1.min-1) during glucose stimulation in four of seven of the youngest fetuses. At 17-20 wk the basal rate of insulin release had increased by at least 15-fold above the detection limit (1.5 pg.ICC-1.min-1), and glucose promoted a sustained monophasic response that was on the average 1.6-fold higher than the basal level. The response was significant (P less than .05) in 9 of 13 experiments. With postnatal ICC (gestational age 26-44 wk), an early-phase peak response was observed in 5 of 6 experiments. The mean rates of insulin release after 5-12 min of glucose stimulation were 4.8 pg.ICC-1.min-1 in newborn infants and 2.1 pg.ICC-1.min-1 in 17- to 20-wk fetuses. The corresponding mean relative insulin responses (stimulated to basal) were 3.3-fold (range 1.1-7.5) and 1.6-fold (1.0-3.4), respectively (P less than .05, Mann-Whitney U test). The results suggest that the human fetal pancreas is already responsive to glucose during the first half of gestation, but the biphasic insulin release does not start to mature until the postnatal phase.     

Placental transfer of fentanyl in early human pregnancy and its detection in fetal brain

We have investigated the transfer of fentanyl across the early human placenta in 38 women (8-14 weeks' gestation) undergoing termination of pregnancy. After administration of a bolus dose of fentanyl 2 micrograms kg-1 at induction of anaesthesia, maternal blood n = 38), placenta (n = 38), amniotic fluid (n = 38) and fetal brain (n = 7) samples were collected and assayed for fentanyl by radioimmunoassay. Fentanyl was detected in all placental and fetal brain samples but not in amniotic fluid. There was a rapid decrease in fentanyl concentrations in maternal serum after the bolus but placental concentrations had not started to decline 30 min later. There was no difference in placental drug concentrations at different gestational ages. These data suggest that there is rapid transfer of fentanyl to the fetus in early pregnancy and that the drug remains in fetal tissue for some time after the initial dose is given to the mother.      

Outcomes of infants born at 23 and 24 weeks' gestation with gut perforation

PurposeThe provision of neonatal intensive care to infants born at 23 or 24 weeks' gestation poses medical, surgical and ethical challenges. Gastrointestinal perforation is a well-recognized complication of preterm birth, occurring most often as a result of necrotizing enterocolitis (NEC) or spontaneous intestinal perforation (SIP). Given the risk of morbidity and mortality in these ‘periviable’ infants, this complication may prompt transition from active management to palliative care. In our institution, the surgical care of periviable infants with gut perforation has not been dictated by gestational age. This study reports our outcomes.MethodsA retrospective cohort analysis of integrated neonatal medical and surgical care of all infants born between 23^{+ 0} and 24^{+ 6} weeks' gestation admitted to a tertiary level neonatal intensive care unit (NICU) during a 16 year period (2002–2017).ResultsA total of 198 periviable neonates (73 born at 23 weeks' gestation and 125 born at 24 weeks) were admitted during the 16-year period; most were inborn with only 26 retrieved from regional centers. Twenty-six of these infants developed gut perforation: 14 SIP, 8 NEC, 3 esophageal perforation and one after reduction of an incarcerated inguinal hernia. Twelve (46%) periviable infants with gut perforation survived to discharge home, seven of whom had no/mild disability at 2–3 years corrected gestational age. Of the 198 periviable infants admitted to NICU, 116 (58%) were alive at a corrected gestational age of 2–3 years and 29 of the 56 (51%) assessed had mild or no disability.ConclusionsIn the setting of combined medical and surgical care in a tertiary level NICU almost half of all periviable infants with a gut perforation survived, many with no/mild disability at 2–3 years corrected gestational age. Rigid protocols that rely on gestational age alone to guide treatment are not appropriate. These results support the contention that, when possible, extremely preterm infants should be born and cared for in units with combined medical and surgical expertise.Level of evidenceLevel III cohort study.     

Asthma is associated with preterm birth but not with small for gestational age status among a population-based cohort of Medicaid-enrolled children <10 years of age

BACKGROUND: Few population-based studies have evaluated the association between birth weight or gestation and subsequent clinically significant asthma. METHODS: Birth records of 37 349 Alaska residents <10 years of age who were enrolled in Medicaid for at least 365 days during 1999-2002 were linked to a Medicaid billing file. The occurrence of asthma and lower respiratory infections during the study period was categorised on the basis of standard International Classification of Diseases 9th Revision codes. The association between gestational age or small for gestational age status and asthma outcomes was adjusted for recent history of lower respiratory infection, years of Medicaid enrolment, age at enrolment and a variety of birth-related factors. RESULTS: Among children <5 years of age, the adjusted odds ratio (OR) for developing asthma decreased by 5.5% (95% confidence interval (CI) -0.2 to 10.9) and 7.9% (95% CI 5.2 to 10.4) per additional week of gestational age for children without and with any lower respiratory tract infection, respectively. For children > or =5 years of age, the adjusted OR for developing asthma decreased by 3.4% (95% CI -2.8 to 9.8) and 3.7% (95% CI -2.0 to 9.2) per additional week of gestation for those without and with lower respiratory tract infection, respectively. Among all children with asthma, the adjusted OR for hospitalisation due to asthma decreased by 6.9% (95% CI 2.1 to 11.5) for each additional week of gestational age. Small for gestational age status was not significantly associated with asthma outcomes. CONCLUSIONS: Preterm birth but not small for gestational age status predicted subsequent asthma outcomes. Adverse effects of preterm birth on asthma outcomes persist beyond age 5 years.     

The radial alveolar count method of Emery and Mithal: a reappraisal 2--intrauterine and early postnatal lung growth.

The radial count method of Emery and Mithal was applied to the lungs of 37 infants of gestational age 19-42 weeks. The method could be used satisfactorily to evaluate airspace-containing lungs, whether alveolated or non-alveolated (saccule-containing). There was a progressive increase in complexity of terminal lung units throughout gestation, and a smooth transition was effected at 1 month of age between the radial counts of the intrauterine cohort and those of a separate group used to study postnatal lung growth. In the intrauterine and early postnatal group radial count results correlated very closely with the total gestational age (gestational age plus survival time after birth) of the child (r = +0.93). Prior inflation of the lungs affected the radial counts of alveolated lungs much more than those of saccule-containing lungs, so that results correlated most closely with those of Emery and Mithal in the period up to 34 weeks' gestation. Radial count estimation correlated better with total gestational age, crown-rump length, body weight, and fixed lung volume than did any other morphometric parameter assessed. The radial count method provides a reliable index of lung growth in intrauterine and early postnatal development.