NPY hyperinnervation in Hirschsprung's disease: both adrenergic and nonadrenergic fibers contribute.

In Hirschsprung's disease, the aganglionic bowel is characterized by an absence of ganglion cells and an increased number of adrenergic and presumed cholinergic nerve fibers. In addition, a severe derangement of peptide-containing nerve fibers is encountered including a hyperinnervation of neuropeptide Y (NPY)-containing fibers. Using immunochemical and immunocytochemical methods, we examined the nature of the NPY-containing nerve fibers contributing to the hyperinnervation. The concentration of NPY was markedly increased in the aganglionic segment. Coexistence of NPY, vasoactive intestinal peptide (VIP), and the adrenergic enzyme tyrosine hydroxylase (TH) showed small populations of nerve fibers containing NPY/TH, NPY/VIP, or TH alone in ganglionic intestine. Numerous nerve fibers stored VIP but lacked NPY. These fibers did not contain TH, indicating that all VIP-containing fibers are nonadrenergic. In the aganglionic intestine there was a marked increase in the number of nerve fibers storing NPY/TH and NPY/VIP, whereas the fibers storing VIP alone were reduced in number. A small number of nerve fibers storing NPY alone occurred in the hypertrophic nerve bundles. NPY/VIP-containing nerve fibers were particularly numerous in the mucosa in aganglionic intestine, which may be of interest in the diagnosis of Hirschsprung's disease allowing the use of mucosal biopsy specimens. Thus, the proliferating NPY-containing nerve fibers in the aganglionic intestine seem to comprise three different populations, one adrenergic and two nonadrenergic, one of which contains in addition VIP.     

Sodium/iodide-symporter: distribution in different mammals and role in entero-thyroid circulation of iodide

The sodium (Na+)/iodide (I-)-symporter (NIS) is abundantly expressed and accumulates iodide in thyroid follicular cells. The NIS is also found in extrathyroidal tissues, particularly gastric mucosa. Controversies exist on the localization of extrathyroidal NIS. We have studied the presence of both NIS peptide and NIS messenger RNA (mRNA) in the digestive tract and thyroid from different mammals. The role of gastric NIS is enigmatic and we aimed to unravel its possible involvement in iodide transport. Methods: Distribution and expression of NIS were studied using immunocytochemistry and in situ hybridization. Iodide transport in the gastrointestinal tract was measured after oral or intravenous (i.v.) administration of 125I to rats with or without ligation of the pylorus. Results: All thyroid follicular cells in rat and mouse expressed NIS, whereas a patchy staining was noted in man, pig and guinea-pig. Gastric mucosa surface epithelium in all species and ductal cells of parotid gland in guinea-pig, rat and mouse expressed NIS. In parietal cells and in endocrine cells of intestines and pancreas NIS immunoreactivity but no NIS mRNA was found. Studies of 125I uptake showed marked iodide transport from the circulation into the gastric lumen. Conclusions: The localization of NIS varies slightly among mammals. To establish expression of NIS in a particular cell type the need to correlate the presence of both NIS protein by immunocytochemistry and NIS mRNA by in situ hybridization is emphasized. An entero-thyroidal circulation of iodide mediated principally by gastric NIS, but possibly also by NIS in salivary glands is suggested.     

Pituitary adenylate cyclase activating peptide: a novel vasoactive intestinal peptide-like neuropeptide in the gut.

Pituitary adenylate cyclase activating peptide (PACAP) is a vasoactive intestinal peptide (VIP)-like hypothalamic peptide occurring in two forms, PACAP-27 and the C-terminally extended PACAP-38. The predicted rat and human PACAP sequence is identical to the isolated ovine one. In the present study, the occurrence and distribution of PACAP-like peptides were examined in the gut of several species by immunocytochemistry and immunochemistry using an antibody raised against PACAP-27. PACAP-like immunoreactivity was observed in nerve fibers in the gut wall of all species examined (chicken, mouse, rat, hamster, guinea-pig, ferret, cat, pig, sheep and man). In the chicken and human gut, immunoreactive fibers were numerous in all layers. In the other species examined the fibers were predominantly found in the myenteric ganglia and smooth muscle. Delicate PACAP-immunoreactive fibers were seen in the gastric mucosa of mouse, rat, hamster and man but not in the other species examined. The chicken proventriculus harbored numerous PACAP-immunoreactive endocrine cells which were identical with the serotonin-containing cells storing gastrin-releasing peptide. PACAP-immunoreactive nerve cell bodies were numerous in the submucous ganglia and moderate in number in the myenteric ganglia of the human gut. They were few in the intramural ganglia of the other species examined. Extrinsic denervation (performed on segments of rat and guinea-pig small intestine) did not visibly affect the PACAP innervation, indicating an intramural origin of most PACAP-immunoreactive fibers. Double immunostaining for VIP and PACAP revealed co-existence of the two peptides in nerve cell bodies and nerve fibers of the human and chicken gut and in fibers in the gastric mucosa of mouse and rat. In all other species examined and in all other locations in the gut PACAP-immunoreactive nerve cell bodies and nerve fibers were distinct from those storing VIP; many of them contained gastrin-releasing peptide instead. Immunochemistry revealed PACAP-like peptides in gut extracts of all species studied; upon high performance liquid chromatography the immunoreactive material co-eluted with synthetic PACAP-27. The distribution of PACAP-immunoreactive nerve cell bodies and nerve fibers in the gut wall suggests their involvement in the regulation of both motor and secretory activities.     

Interventional treatment of children with portal hypertension secondary to portal vein occlusion.

PURPOSE: To present methods and results of interventional treatment of children with portal hypertension (PH) secondary to portal vein occlusion (PVO). MATERIAL AND METHODS: Five children, four boys and one girl, 8 - 14 years old, with symptomatic PH secondary to PVO were treated. All children had one or more episodes of bleeding from oesophageal varices, enlarged spleen and thrombocytopenia. Partial embolisation of the spleen was performed in four children. Attempts to recanalize the occluded part of the portal vein were done in all children using transjugular (n = 4), transhepatic (n = 4) and transsplenic (n = 3) approaches. RESULTS: All procedures were carried out without serious complications and were followed by normalisation of the platelet count, decrease in splenic size and disappearance of bleeding. Recanalisation of the occluded portal vein with a stent was possible in one child and partial stent recanalisation was possible in another child. Transjugular intrahepatic portosystemic shunt (TIPS) with partly extrahepatic, intraperitoneal route was created in one patient. All children were scheduled for follow-up. During the observation time of 22 months (5 - 46 months), additional balloon dilation and placement of new stents were necessary in two children. CONCLUSION: Interventional procedures are valuable in the treatment of children with symptoms secondary to PVO. Treatment should be customized and scheduled follow-ups of the patients are necessary.     

The host defense peptide LL‐37 is detected in human parotid and submandibular/sublingual saliva and expressed in glandular neutrophils

The human host defense peptide, LL‐37, is an important player in the first line of defense against invading microorganisms. LL‐37 and its precursor, hCAP18, have been detected in unstimulated whole saliva but no reports showing hCAP18/LL‐37 in isolated, parotid, and/or submandibular/sublingual saliva have been presented. Here, we measured the levels of hCAP18/LL‐37 in human parotid and submandibular/sublingual saliva and investigated the expression of hCAP18/LL‐37 in parotid and submandibular gland tissue. Parotid and submandibular/sublingual saliva was collected from healthy volunteers, and the levels of hCAP18/LL‐37 in saliva were analyzed by dot blot, ELISA, and western blotting. Cellular expression of hCAP18/LL‐37 in human parotid and submandibular glands was investigated by immunohistochemistry. Immunoreactivity for hCAP18/LL‐37 was detected in both parotid and submandibular/sublingual saliva of all individuals. The concentration of hCAP18/LL‐37 was similar in parotid and submandibular/sublingual saliva, and was determined by densitometric scanning of each dot and normalization to the total protein concentration of each sample, and by ELISA. Double immunohistochemistry revealed that intravascular neutrophils of both parotid and submandibular glands express hCAP18/LL‐37. For the first time, we demonstrate hCAP18/LL‐37 in isolated human parotid and submandibular/sublingual saliva and expression of hCAP18/LL‐37 in glandular intravascular neutrophils, indicating that neutrophils of the major salivary glands contribute to the LL‐37 content of whole saliva.     

Adrenocorticotropin and corticotropin-releasing hormone tests in preterm infants

The short ACTH test is used in evaluating the hypothalamo-pituitary-adrenal axis (HPA-axis) in preterm neonates after dexamethasone treatment. This test mainly examines primary adrenal suppression but is also used as a method to test secondary adrenal insufficiency because long-term deprivation of ACTH causes atrophy of the adrenal cortex. The CRH test, on the other hand, directly examines the function of the pituitary. We tested 18 infants in the neonatal intensive care unit with both the ACTH test and the CRH test to determine which of these two tests more reliably demonstrates HPA-axis suppression. One patient had normal responses both in the ACTH test and in the CRH test when the limit of 360 nmol/L was used as a sign of proper cortisol secretion. In four cases the patients' cortisol secretion would have been regarded as normal by the low-dose ACTH test, whereas the CRH test did not show an adequate cortisol response. In conclusion, the ACTH test did not reliably indicate HPA-axis suppression after a short (<2 weeks) course of dexamethasone therapy in this study. Therefore, whether the infant is or will be under acute stress after short glucocorticoid treatment, ensuring adequate cortisol secretion with the CRH test should be considered.     

Neuropeptides in the human appendix

At present our knowledge of enteric peptide-containing neurons in man is limited. In this study we have used human appendices removed at surgery to examine the peptidergic innervation by immunocytochemistry, immunochemistry, and pharmacological in vitro experiments. Immunocytochemistry revealed a variety of peptide-containing nerve fiber populations in the human appendix. VIP/PHI-, VIP/PHI/NPY-, SP/NKA-, galanin-, and enkephalin-containing nerve fibers were numerous; CGRP- and GRP-containing nerve fibers were moderate in number, while only scattered NPY-, enkephalin/BAM-, and somatostatin-containing nerve fibers could be found. No CCK-, dynorphin A-, or dynorphin B-immunoreactive nerve fibers could be detected. The coexistence of VIP/PHI, SP/NKA, and enkaphalin/BAM can be anticipated from the known sequence of their respective precursors. However, the coexistence of VIP/PHI and NPY was unexpected but corroborates previous observations in other species. Interestingly, SP and CGRP did not seem to coexist in nerve fibers of the human appendix. Immunochemistry (RIA and HPLC) confirmed the presence of VIP, NPY, SP, galanin, CGRP, GRP, enkephalin, and somatostatin. Motor activity studies suggest that acetylcholine plays a major role in the electrically evoked contractions, since atropine suppressed these contractions. Galanin (10(-8)-10(-6) M) and GRP (10(-9)-10(-7) M) caused concentration-dependent contractions that were unaffected by tetrodotoxin and thus probably reflect a direct action on smooth muscle receptors. GRP (10(-9) M) enhanced the electrically induced cholinergic contraction (to 193 +/- 24%), while met-enkephalin (10(-6) M) reduced it (to 54 +/- 6%). Both peptides failed to affect the contractile response to exogenous acetylcholine and probably act to modulate the release of acetylcholine. NPY, VIP, CGRP, SP, and somatostatin failed to induce contraction or to affect the electrically evoked contractions.     

In Vivo Evaluation and Dosimetry Estimate for a High Affinity Affibody PET Tracer Targeting PD-L1

Molecular Imaging and Biology - In vivo imaging of programmed death ligand 1 (PD-L1) during immunotherapy could potentially monitor changing PD-L1 expression and PD-L1 expression heterogeneity...     

The degree of fetal metformin exposure does not influence fetal outcome in gestational diabetes mellitus

The purpose of the study was to examine in vivo placental transfer of metformin, its association with neonatal outcome in metformin-treated gestational diabetes (GDM) patients, and influence of metformin exposure on maternal glycemic control and weight gain. Two hundred and seventeen GDM patients were randomized to metformin or insulin in Turku University Hospital, Finland. Metformin concentrations were determined by mass spectrometry in maternal serum at 36 gestational weeks (gw) and at birth, and in umbilical cord blood. Main outcome measures were birth weight, gw at birth, umbilical artery pH and neonatal hypoglycemia, maternal weight gain, HbA1c and fructosamine concentration. Median umbilical cord/maternal serum metformin concentration ratio was 0.73. There were no differences in birth weight measured in grams or SD units (p = 0.49), or gw at birth (p always ≥0.49) between insulin- and metformin-treated patients stratified by trough metformin concentration tertiles measured at 36 gw. Rate of neonatal hypoglycemia (p = 0.92) and umbilical artery pH value (p = 0.78) was similar in insulin- and metformin-treated patients stratified by cord metformin concentration tertiles. Maternal glycemic control was similar in metformin concentration tertiles at 36 gw. Maternal weight gain was 223 g greater per week (p = 0.038) in the lowest metformin tertile compared to other tertiles combined. Maternal and fetal exposure to metformin is similar. Maternal or fetal metformin concentrations do not predict maternal glycemic control or neonatal outcome, but low maternal exposure may lead to greater maternal weight gain.