Pediatric burns in the Bedouin population in southern Israel

Burn trauma is an important public health concern, with increased risk for burns in children. A cross-sectional study was performed to describe the epidemiological characteristics and risk factors for burns in hospitalized Bedouin children in Soroka University Medical Center during the years 2001–2002. In a population of 558 hospitalized burn-injured patients, 282 Bedouin children were identified. Two hundred and sixty five patients (94.0%) had burns involving less than 20% of the body surface area. Cause of the burns was scald in 190 patients (67.4%), fire in 80 patients (28.4%), chemical in 8 patients (2.8%), and explosion in 2 patients (0.7%). Two female patients (0.7%) aged 11 and 17 years died of their burns that were caused by fire. The mean length of hospitalization was 9.8 days. Pediatric burn injury has become a significant public health problem in the Bedouin population of the Negev. To reduce the burden of burn injury, it is necessary to increase current efforts in prevention of burns.

Burns at the soroka university medical center - a two-year experience

Background. Burn trauma is a major public health concern, with increased risk for burns in children. Objectives. To characterize the profile of injured burn patients and to identify patients who are prone to burn injury. Methods. This is a cross-sectional study including all patients who were admitted to the Burns and Plastic Surgery Department, Soroka University Medical Center, Israel, between 1 January 2001 and 31 December 2002. Results. Five hundred and fifty-eight patients with a mean age of 15.4 yr (SD, 19.5 yr) were included in the study. There were 348 male patients (62.4%). The cause of the burns was scalding in 314 patients (56.3%), flame in 177 (31.7%), chemicals in 31 (5.6%), explosion in 20 (3.6%), and electricity in four (0.7%). There were 325 Bedouin patients (58.2%) and 221 Jewish patients (39.6%). In Bedouins, 235 patients (72.3%) were children below 5 yr, compared to 59 Jewish patients (26.7%) (p < 0.001). Eighteen burn patients (3.2%) expired. A multivariate analysis demonstrated that age and percentage of body surface area involved in the burn were significantly associated with mortality. Conclusions. The epidemiological characteristics of the burned population in Soroka University Medical Center are described. Burn injury has become a principal public health problem, particularly in Bedouin children.

Pancreatic small cells: Analysis of quiescence, long-term maintenance and insulin expression in vitro

We have previously identified a novel population of small cells in human and canine pancreas characterized by immature morphology, quiescence, and a glucose-responsive insulin secretion. Based on their immature phenotype and predominant presence in small islets, we have hypothesized that small cells serve as islet progenitors. This hypothesis remains untested, however, due to persistent quiescence and scarcity of small cells in vitro. We have recently developed a culture medium that allowed for modest small cell proliferation. In this study we characterized the expression of genes potentially involved in small cell growth regulation by Q-RT-PCR. Our results suggest that quiescence of small cells correlates with up-regulation of Cdk inhibitors p27(Kip1), p16(INK4a) and p21(CIP1), PTEN, Hep27 and Foxo1a and with down-regulation of c-Myc and the receptors for EGF, FGF2 and HGF. The exit from quiescence correlates with activation of EGFR expression and down-regulation of p27(Kip1) and p16(INK4a). We also report here that small cells can be maintained in long-term non-adherent cultures preserving insulin and glucagon production for up to 208 days. Therefore, expansion of small cells in vitro may have a significant potential for the treatment of diabetes. This study is an important step in understanding the mechanisms involved in small cell growth regulation, which is required to fully evaluate their functional potential.

Evidence for the homeostatic regulation of induced beta cell mass expansion

AIMS/HYPOTHESIS

Diabetes results from an insufficient insulin-secreting beta cell mass. Restoration of beta cell mass through pharmaceutically induced endogenous beta cell mass expansion may revolutionise diabetes therapy. However, it remains to be determined whether the induced beta cell mass expansion is under homeostatic regulation.

METHODS

Beta cell mass expansion rates were derived from three separate studies of continuous stimulation of islet neogenesis, including the partial duct obstruction of euglycaemic Syrian hamsters, administration of a pentadecapeptide with the same amino acid sequence as residues 104-118 of islet neogenesis-associated protein (INGAP(104-118)) to euglycaemic Syrian hamsters, as well as to euglycaemic CD-1 mice. The incidence of islet neogenesis, average beta cell size, and beta cell replication and apoptotic rates were determined.

RESULTS

Partial duct obstruction led to a approximately 2.5-fold increase in endocrine tissue at day 56 (p<0.05). From day 0 to day 7 the average rate of change of islet area was 12.7% per day, and this rate decreased to 5.3% per day from day 7 to day 42, and to 2.8% per day from day 42 to day 56. Administration of INGAP(104-118) to adult hamsters led to a 31% increase in total beta cell mass at day 30 (p=0.031). From day 0 to day 10 the average rate of beta cell mass expansion was 148 mug/day, whereas from day 10 to day 30 it decreased to 45 mug/day. INGAP(104-118) administration to adult CD-1 mice resulted in an approximately twofold increase in beta cell mass after 31 days (p=0.021). However, at day 90, there was no significant difference vs age-matched control mice (p=0.30), even though the neogenic beta cell mass was approximately fourfold greater (p=0.026). Beta cell replication was decreased by 56% (p<0.048), whereas beta cell apoptosis was fourfold greater (p<0.003) in 90-day INGAP(104-118)-treated mice compared with age-matched control mice.

CONCLUSIONS/INTERPRETATION

These data indicate that in the presence of ongoing islet neogenesis, homeostatic regulatory mechanisms intervene to regulate beta cell mass according to the prevailing metabolic requirements.

Autocrine insulin action activates Akt and increases survival of isolated human islets

AIMS/HYPOTHESIS

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway plays a critical role in promoting the survival of pancreatic beta cells. Akt becomes activated in isolated human islets following overnight culture despite significant levels of cell death. The aim of the current study was to identify the cause of the observed increase in Akt phosphorylation in isolated islets. We hypothesised that a factor secreted by the islets in culture was acting in an autocrine manner to activate Akt.

METHODS

In order to identify the stimulus of the PI3K/Akt pathway in culture, we examined the effects of different culture conditions on Akt phosphorylation and islet survival during the immediate post-isolation period.

RESULTS

We demonstrated that islet-conditioned medium induced Akt phosphorylation in freshly isolated human islets, whereas frequent medium replacement decreased Akt phosphorylation. Following overnight culture, islet-conditioned medium contained significantly elevated levels of insulin, indicating that insulin may be responsible for the observed increase in Akt phosphorylation. Indeed, treatment with an anti-insulin antibody or with inhibitors of insulin receptor/IGF receptor 1 kinase activity suppressed Akt phosphorylation, leading to decreased islet survival. In addition, dispersion of islets into single cells also suppressed Akt phosphorylation and induced islet cell death, indicating that islet integrity is also required for maximal Akt phosphorylation.

CONCLUSIONS/INTERPRETATION

Our findings demonstrate that insulin acts in an autocrine manner to activate Akt and mediate the survival of isolated human islets. These findings provide new information on how culturing islets prior to transplantation may be beneficial to their survival by allowing for autocrine activation of the pro-survival Akt pathway.

Energy dependence of directed flow over a wide range of pseudorapidity in Au + Au collisions at the BNL Relativistic Heavy Ion Collider

We report on measurements of directed flow as a function of pseudorapidity in Au + Au collisions at energies of square root of SNN = 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the BNL Relativistic Heavy Ion Collider. These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.