Subcommissural organ-Reissner's fiber complex of the teleost Clarias batrachus responds to GABA treatment

Subcommissural organ (SCO) is a highly specialized ependymal gland located in the roof of the third ventricle. The secretory products of the SCO, which condense to form Reissner's fiber (RF), were recently found to cross-react with the anti-calcitonin antibody. To understand the mechanisms regulating the formation of the RF and the possible function of these discrete structures, we studied the response of the SCO-RF complex to intracranially administered GABA, using immunocytochemical labeling with anti-calcitonin antibody. Although the SCO-RF complex of control fish was intensely immunostained, 1 h after GABA treatment, the ependymal cells revealed partial loss of immunoreactivity; the RF showed occasional loss of immunoreactivity with its diameter increased by about 56% of the control value. Following 2 h of GABA treatment, the SCO revealed dramatic loss of calcitonin-like immunoreactivity from the ependymal cells. The RF showed a dual response in this group, while in some segments the RF appeared conspicuously thick, elsewhere it appeared thin. The mean diameter was, however, not significantly different from the normal. Following 4 h of GABA treatment, while calcitonin-like immunoreactive material made its reappearance in the SCO, the RF diameter was uniformly reduced to about 35% of the control value. The responses by the RF as well as the SCO to intracranially administered GABA were blocked by pretreatment with bicuculline, a GABA(A) receptor antagonist. The results suggest that GABA, acting via GABA(A) receptors, may trigger the release of secretory material from the SCO and induce histomorphological changes in the RF indicative of discharge of stored material.     

Recent advances in diagnosis and management of pulmonary hypertension in chronic lung disease

Pulmonary hypertension with elevated pulmonary vascular resistance is a common cardiovascular complication associated with increased morbidity and mortality in preterm infants with chronic lung disease. Injury to the developing pulmonary circulation results in structural and functional abnormalities of the pulmonary vasculature. Animal studies have demonstrated that disruption of angiogenesis may contribute to the failure of normal alveolarisation in chronic lung disease. Levels of vascular endothelial growth factor in bronchoalveolar lavage fluid are lower in infants with chronic lung disease compared to preterm controls. Supplemental oxygen is commonly used to prevent and treat pulmonary hypertension, although optimal arterial oxygen saturation levels remain uncertain. Other vasodilators such as inhaled nitric oxide appear promising, but as yet have not been evaluated in the form of randomised controlled trials. Further studies are required to investigate the long-term effectiveness of pulmonary vasodilator therapy.     

FMRFamide-like immunoreactive nervus terminalis innervation to the pituitary in the catfish, Clarias batrachus (Linn.): demonstration by lesion and immunocytochemical techniques.

Certain thick FMRFamide-like immunoreactive fibers arising from the ganglion cells of nervus terminalis in the olfactory bulb of Clarias batrachus can be traced centripetally through the medial olfactory tract, telencephalon, lateral preoptic area, tuberal area, and hypothalamohypophysial tract to the pituitary. Following 6 days of bilateral olfactory tract transection, the immunoreactivity in the thick fibers, caudal to the lesion site, was partially eliminated, whereas after 10 and 14 days, it was totally abolished in the processes en route to the pituitary. The results indicate a direct innervation of the pituitary gland by the FMRFamide-like peptide containing fibers of the nervus terminalis.     

ASO Visual Abstract: Time to Surgical Treatment and Facility Characteristics as Potential Drivers of Racial Disparities in Breast Cancer Mortality: Delay,Facilities, and Breast Cancer Mortality

Annals of Surgical Oncology -     

Combination of positional therapy with positive airway pressure for titration in patients with difficult to treat obstructive sleep apnea

Sleep and Breathing - Positional therapy has been described as add-on therapy to a mandibular advancement device, but the efficacy of combination of positional therapy and positive airway pressure...     

Risk factors for pancreatic fistula after stapled gland transection

The objective of this study was to identify risk factors for pancreatic fistula (PF) after stapled transection in distal pancreatectomy (DP). Patients undergoing DP using a stapler for transection between 2005 and 2009 were identified from a pancreatic resection database. Variables examined included patient and tumor characteristics, staple size, and the use of mesh reinforcement. Univariate and multivariate regression analyses were performed to identify risk factors for postoperative PF. One hundred forty-nine had stapled transection, and of these, 25 (17%) had mesh reinforcement. The overall morbidity and mortality rates were 28 per cent and less than 1 per cent; 34 (23%) were diabetic. The rate of clinically significant PF was 14 per cent. On univariate analysis, diabetes (P = 0.04), a firm pancreas (P = 0.03), use of mesh staple line reinforcement (P = 0.02), use of a 4.1-mm staple cartridge (P = 0.01), and blood loss greater than 100 mL (P = 0.01) were associated with higher pancreatic fistula rates. On multivariate analysis, only the presence of diabetes (OR, 4.17; 95% CI, 1.1-15.3; P = 0.03) and the use of a 4.1-mm cartridge (OR, 8.57; 95% CI, 1.2-60.2; P = 0.03) were independently associated with pancreatic fistula formation. Stapled pancreatic transection provides an acceptable PF rate after DP. Diabetes and staple size influence PF rates. In our experience, use of mesh staple line reinforcement did not reduce the incidence of PF after stapled transection.     

Identification of the cell types in the rostral pars distalis of the pituitary gland of the catfish, Clarias batrachus (Linn)

The cells in the rostral pars distalis (RPD) of the hypophysis of the catfish, Clarias batrachus were distinguished into 2 types by tinctorial affinities, and their functional significance was ascertained experimentally. The lead haematoxylin (PbH)-positive cells of the RPD, herein referred to as the cell type 1, are in the form of a 3-8 cell layer thick palisade along the border between the neurohypophysis (NH) and the RPD. Administration of metopirone caused significant stimulatory changes in these cells, whereas injection of ACTH, hydrocortisone or dexamethasone resulted in marked regression suggesting their ACTH-secreting nature. The type 2 cells constitute a major part of the RPD and are erythrosinophilic in nature. They showed regressive changes after immersion of the catfish in sodium chloride solution and distilled water, and a similar change was observed after injection of prolactin which indicates their prolactin-secreting nature.     

Neuropeptide Y in the forebrain of the adult male cichlid fish Oreochromis mossambicus: distribution, effects of castration and testosterone replacement

We studied the organization of the neuropeptide Y (NPY)-immunoreactive system in the forebrain of adult male cichlid fish Oreochromis mossambicus and its response to castration and testosterone replacement by using morphometric methods. Immunoreactivity for NPY was widely distributed in the forebrain, and the pattern generally resembled that in other teleosts. Whereas immunoreactivity was conspicuous in the ganglia of nervus terminalis (NT; or nucleus olfactoretinalis), a weak reaction was detected in some granule cells in the olfactory bulb and in the cells of area ventralis telencephali pars lateralis (Vl). Moderately to intensely immunoreactive cells were distinctly seen in the nucleus entopeduncularis (NE), nucleus preopticus (NPO), nucleus lateralis tuberis (NLT), paraventricular organ (PVO), and midbrain tegmentum (MT). NPY fibers were widely distributed in the forebrain. Castration for 10/15 days resulted in a drastic loss of immunoreactivity in the cells of NE (P<0.001) and a significant decrease (P<0.01) in their cell nuclear size. However, cell nuclei of the NT neurons showed a significant increase in size. A highly significant reduction in the NPY-immunoreactive fiber density (P<0.001) was observed in several areas of the forebrain. Although testosterone replacement reversed these changes, fibers in some areas showed supranormal responses. Immunoreactive cells in Vl, NPO, NLT, PVO, and MT and fiber density in some other areas did not respond to castration. We suggest that the NPY-immunoreactive elements that respond to castration and testosterone replacement may serve as the substrate for processing the positive feedback action of the steroid hormone.     

Concentrations of cardiac troponin T in neonates with and without respiratory distress

AIMS: To establish a practical postnatal reference range for cardiac troponin T in neonates and to investigate concentrations in neonates with respiratory distress. METHODS: Prospective investigation in a tertiary neonatal unit, recruiting infants with and without respiratory distress (sick and healthy infants respectively). Concentrations of cardiac troponin T were compared between sick and healthy infants, accounting for confounding variables. RESULTS: A total of 162 neonates (113 healthy and 49 sick infants) had samples taken. The median (interquartile range) cardiac troponin T concentration in the healthy infants was 0.025 (0.01-0.062) ng/ml, and the 95th centile was 0.153 ng/ml. There were no significant relations between cardiac troponin T and various variables. The median (interquartile range) cardiac troponin T concentration in the sick infants was 0.159 (0.075-0.308) ng/ml. This was significantly higher (p < 0.0001) than in the healthy infants. In a linear regression model, the use of inotropes and oxygen requirement were significant associations independent of other basic and clinical variables in explaining the variation in cardiac troponin T concentrations. CONCLUSIONS: Cardiac troponin T is detectable in the blood of many healthy neonates, but no relation with important basic and clinical variables was found. Sick infants have significantly higher concentrations than healthy infants. The variations in cardiac troponin T concentration were significantly associated with oxygen requirement or the use of inotropic support in a regression model. Cardiac troponin T may be a useful marker of neonatal and cardiorespiratory morbidity.