Human amniotic fluid promotes retinal pigmented epithelial cells' trans-differentiation into rod photoreceptors and retinal ganglion cells

To evaluate the effect of human amniotic fluid (HAF) on retinal pigmented epithelial cells growth and trans-differentiation into retinal neurons, retinal pigmented epithelium (RPE) cells were isolated from neonatal human cadaver eye globes and cultured in Dulbecco's modified Eagle's medium-F12 supplemented with 10% fetal bovine serum (FBS). Confluent monolayer cultures were trypsinized and passaged using FBS-containing or HAF-containing media. Amniotic fluid samples were received from pregnant women in the first trimester of gestation. Cell proliferation and death enzyme-linked immunosorbent assays were performed to assess the effect of HAF on RPE cell growth. Trans-differentiation into rod photoreceptors and retinal ganglion cells was also studied using immunocytochemistry and real-time polymerase chain reaction techniques. Primary cultures of RPE cells were successfully established under FBS-containing or HAF-containing media leading to rapid cell growth and proliferation. When RPE cells were moved to in vitro culture system, they began to lose their differentiation markers such as pigmentation and RPE65 marker and trans-differentiated neural-like cells followed by spheroid colonies pertaining to stem/progenitor cells were morphologically detected. Immunocytochemistry (ICC) analysis of HAF-treated cultures showed a considerable expression of Rhodopsin gene (30% Rhodopsin-positive cells) indicating trans-differentiation of RPE cells to rod photoreceptors. Real-time polymerase chain reaction revealed an HAF-dose-dependant expression of Thy-1 gene (RGC marker) and significant promoting effect of HAF on RGCs generation. The data presented here suggest that HAF possesses invaluable stimulatory effect on RPE cells growth and trans-differentiation into retinal neurons. It can be regarded as a newly introduced enriched supplement in serum-free kinds of media used in neuro-retinal regeneration studies.     

Alteration of rat hippocampal neurogenesis and neuronal nitric oxide synthase expression upon prenatal exposure to tamoxifen

The present study delineates the effect of tamoxifen on neuronal density and expression of neuronal nitric oxide synthase (nNOS) in hippocampal nerve cells during prenatal and postnatal periods in rats. Pregnant rats were administered with tamoxifen one day prior to labor (E21) and on the childbirth day (E22). Hippocampi of embryos at E22 and newborns at postnatal days of 1, 7, and 21 (P1, P7, and P21) were investigated. Density of the neurons in areas of the developing hippocampus including cornu ammonis (CA1, CA3), dentate gyrus, and subiculum were studied. Our findings show that the number of pyramidal neurons was significantly decreased in CA1 and subiculum of tamoxifen-treated rats in E22, P1, and P7. We found that cellular density was lower in early stages of development, however, cellular density and thickness gradually increased during the development particularly in the third week. We found that nNOS expression was decreased in E22, P1, and P7 in animals treated with tamoxifen. The present study shows that tamoxifen affects development and differentiation of postnatal rat hippocampus, CA1 neurons, and nNOS expression.     

Traumatic pseudoaneurysms of the liver and spleen in children: is routine screening warranted?

Background

Although blunt injury to the spleen and liver can lead to pseudoaneurysm formation, current surgical guidelines do not recommend follow-up imaging. Controversy exists regarding the clinical implications of these traumatic pseudoaneurysms as well as their management.

Methods

Retrospective review of children treated nonoperatively for isolated blunt liver and spleen trauma between 1991 and 2008 was undertaken. Patient demographics, grade of injury, and follow-up Doppler ultrasound results were obtained.

Results

Three hundred sixty-two children were identified. One hundred eighty-six of them had splenic injuries, and 10 (5.4%) developed pseudoaneurysms. They were associated with grade III (3/39 [8%]) and grade IV (7/41 [17%]) injuries. In 7 patients, the pseudoaneurysm thrombosed spontaneously. Angiographic embolization was required in 2 children, and one underwent emergency splenectomy for delayed hemorrhage. Of the 176 patients who had liver injuries, 3 (1.7%) developed pseudoaneurysms. All 3 were associated with grade IV injuries (3/11 [27%]). One child underwent early embolization, while 2 developed delayed hemorrhage requiring emergent treatment.

Conclusions

Pseudoaneurysm development after blunt abdominal trauma is associated with high-grade splenic and liver injuries. Routine screening of this group of patients before discharge from hospital may be warranted because of the potential risk of life-threatening hemorrhage.     

Preoperative oral dextromethorphan vs. clonidine to prevent tourniquet-induced cardiovascular responses in orthopaedic patients under general anaesthesia

BACKGROUND AND OBJECTIVE: Preoperative oral dextromethorphan and intravenous clonidine attenuate arterial pressure and heart rate increases during tourniquet inflation under general anaesthesia. The effect of preoperative oral clonidine on these variables has not been investigated. METHODS: We designed this study to compare the effect of preoperative oral dextromethorphan or clonidine on haemodynamic changes during tourniquet inflation in 75 patients undergoing lower limb surgery under general anaesthesia. Patients were randomly assigned into three groups: dextromethorphan 30 mg (n = 25), clonidine 3 microg kg(-1) (n = 25) and placebo (n = 25). Anaesthesia was maintained with isoflurane 1.2% and N2O 50% in oxygen with endotracheal intubation. Dextromethorphan, clonidine or placebo was given orally in a double-blinded fashion 90 min before induction of anaesthesia. Systolic, diastolic and mean arterial pressure and heart rate were measured at 0, 30, 45, 60 min after the start of tourniquet inflation, before tourniquet release and 20 min after tourniquet deflation. RESULTS: Systolic, diastolic and mean arterial pressure were significantly lower in the clonidine group compared with control after 45, 60 min tourniquet inflation and before tourniquet release (P < 0.05). Twenty minutes after deflation, diastolic and mean arterial pressure in the control group were still increased and significantly higher compared with the clonidine group (P < 0.05). Development of more than a 30% increase in systolic arterial pressure during tourniquet inflation was more frequent in the control group than in the other groups. CONCLUSIONS: Preoperative oral clonidine 3 microg kg(-1) significantly prevented tourniquet-induced systemic arterial pressure increase in patients under general anaesthesia better than oral dextromethorphan.     

Recent trends in hospital utilization for acute myocardial infarction and coronary revascularization in the United States

Medical advances may be shifting patients with coronary artery disease away from the hospital setting despite an aging United States population. We explored this possibility using national inpatient data to estimate the number and population-based rates of hospitalization for acute myocardial infarction (AMI) and coronary revascularization from 2002 to 2005. Our primary data source was the Acute Care Tracker database, a proprietary administrative database that contains data on approximately 6 million discharges per year from 458 hospitals across the United States. Using the Acute Care Tracker database, we estimated the annual number and population-based rates of hospitalization for AMI (transmural, subendocardial) and coronary revascularization (percutaneous coronary intervention [PCI] and coronary artery bypass grafting [CABG]). Hospitalizations for AMI steadily decreased from 661,000 to 591,000 per year between 2002 and 2005, primarily due to decreases in transmural AMI. Hospitalizations for coronary revascularizations during this period varied between 794,000 and 815,000 per year, with the number of PCIs increasing and the number of CABGs decreasing. In addition, rates of hospitalization for AMI decreased from 309 to 266 per 100,000 persons between 2002 and 2005, with rates of transmural AMI decreasing substantially from 118 to 87 per 100,000 persons. Rates of hospitalization for coronary revascularization also decreased from 382 to 358 per 100,000 during this period, primarily due to decreases in CABG. In conclusion, the number and rates of hospitalization for AMI and coronary revascularization in the United States are decreasing.     

Bowel-defect disproportion in gastroschisis: does the need to extend the fascial defect predict outcome?

Background/purpose  

Validated outcome prediction for gastroschisis (GS) permits early risk stratification. The aim of our study was to determine whether the need for GS defect extension: (a) correlates with bowel injury severity at birth, and (b) predicts outcome.