Mechanism and outcomes of recreational and sports-related open globe injuries.

OBJECTIVES: To describe the mechanisms and visual outcomes of recreational and sports-related open globe injuries (OGIs). METHODS: A retrospective case series of eyes experiencing OGI secondary to recreational and sports-related activities at Memorial Hermann Hospital - Texas Medical Center (MHH-TMC) from January 1st, 2010 through March 31st, 2015 was conducted. Exclusionary criteria included no documented ophthalmologic examination upon presentation and repairs performed by services other than ophthalmology. A two-tailed t-test and Fisher's exact test were utilized to assess for statistical significance (p < 0.05). RESULTS: A total of 20 eyes from 20 patients experiencing OGIs secondary to recreational and sports-related activities were included. Thirteen eyes (65 %) presented with OGIs from penetrating objects while seven eyes (35 %) had injuries from blunt injuries. Males comprised most of the total study group (17 of 20 patients), and zone 3 injuries were the most common location of OGI. While eyes with OGIs from blunt trauma underwent evisceration/enucleation procedures more frequently than OGIs from penetrating mechanisms (71% vs 23 %) (p = 0.10), the final visual outcomes were similarly poor between groups. Only three eyes in this series experienced an improvement from baseline VA; all three eyes had lacked initial findings consistent with severe injury. CONCLUSIONS: Recreational and sports related OGIs most commonly occur in zone 3 and in young males, regardless of injury type. OGIs due to both penetrating and blunt trauma mechanisms implicate poor functional outcomes, but the absence of certain presenting injury features may indicate possibility of eventual visual recovery.

Incidence of implantable Collamer lens-induced cataract.

OBJECTIVE: Although the literature on the implantable Collamer lens (ICL) suggests an increasing rate of anterior subcapsular cataract (ASC) development with increasing age and decreasing anterior chamber depth (ACD), the exact correlation is not known. We performed a retrospective observation study of 1653 eyes and calculated the incidence of ICL removal with cataract extraction and intraocular lens placement (CE-IOL) as a result of ASC, in correlation to patient's age and ACD. DESIGN: Retrospective observation study. SETTING: The Gimbel Eye Centre, Calgary, Alberta, Canada. METHODS: We analyzed ICL V4 model (Visian ICL; STAAR Surgical, Monrovia, CA) implanted in 1653 eyes with myopia from 2000 to 2012 at the Gimbel Eye Centre, Calgary. Myopic patients aged 19 years and older with no history of cataracts were included. The rate of ICL removal with cataract extraction was calculated. Parameters such as age, sex, refractive sphere, refractive cylinder, length of follow-up, and ACD were collected. Cataract-free survival with comparison of FDA and non-FDA cohorts was conducted using Kaplan-Meier survival curves with the log-rank test. In addition, covariates adjusted hazards ratios and 95% confidence intervals were calculated using Cox regression. RESULTS: Of the 1653 eyes included in this study, a total of 46 eyes underwent ICL removal with CE-IOL. The length of follow-up varied between 2 and 14 years. CONCLUSIONS: This retrospective study demonstrated that the rate of developing ASCs positively correlated with age and negatively correlated with ACD.

Outcomes related to burn-related child abuse: a case series.

Nationally, approximately 10% of child abuse cases involve burning, and up to 20% of pediatric burn admissions involve abuse or neglect. Historically, these cases have been more difficult to prosecute than nonburn cases for multiple reasons. Between 1995 and 1999, there were 285 pediatric (under 18) patients admitted to the Spectrum Health Regional Burn Center. Of these cases, 18 of the alleged perpetrators were legally investigated for suspicion of child abuse, and 7 received punitive sentences. We found that men tended to be prosecuted and convicted more often than women and that cases involving multiple instances of injury tended to be prosecuted more frequently. Similarly, we found that cases involving more severe injuries tended to be prosecuted more successfully. There are many psychological and social factors involved in handling burn abuse cases. However, by successful prosecution of these crimes, victims tend to fare better both socially and psychologically.

Epipen as an alternative to glucagon in the treatment of hypoglycemia in children with diabetes.

OBJECTIVE: Fear of a severe hypoglycemic reaction is a major obstacle to achieving near-normal plasma glucose levels. Although parenteral glucagon is effective in treating these reactions, it is cumbersome to use, causes severe nausea, and is impractical in the school setting. Epinephrine is available as a premixed injection (Epipen) that may be used by all care providers. Using Epipen to treat hypoglycemia may be an effective, safe, and easy-to-use alternative to glucagon. RESEARCH DESIGN AND METHODS: Ten children (age 11.7 +/- 2.4 years) with type 1 diabetes were studied on two occasions. After an overnight equilibration period, hypoglycemia was induced via an insulin pump (1 mU x kg(-1) x min(-1)). At a blood glucose level of 2.8 mmol/l, either glucagon (1 mg) or epinephrine (0.3 mg), in random order, was administered intramuscularly and responses were monitored. RESULTS: Plasma free insulin concentrations were similar in both studies. Plasma glucose levels increased by 1.7 +/- 0.2 mmol/l (mean +/- SEM) in 10 min and by 2.6 +/- 0.2 mmol/l in 15 min with administration of glucagon and were not consistently increased with administration of epinephrine (P < 0.01). Peak glucagon concentrations after administration of glucagon were >60-fold higher than basal concentrations. After administration of epinephrine, peak epinephrine levels were 20-fold higher than basal concentrations. CONCLUSIONS: Epinephrine does not seem to be an adequate substitute for glucagon in the treatment of severe hypoglycemia. The effectiveness of glucagon in reversing hypoglycemia and its side effects of nausea and vomiting are likely related to the markedly supraphysiologic plasma levels achieved with the standard intramuscular dose.

Augmentation of alimentary insulin secretion despite similar gastric inhibitory peptide (GIP) responses in juvenile obesity.

Insulin secretion rates are greater after oral glucose than after parenteral administration of an equivalent glucose load. This augmented beta-cell secretory response to an oral glucose load results from the release of mainly two gut hormones: gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1, which potentiate glucose-induced insulin secretion. Because of their insulinotropic action, their abnormal secretion may be involved in the pathogenesis of the hyperinsulinemia of childhood obesity. In this study, we used the hyperglycemic clamp with a small oral glucose load to assess the effect of childhood obesity on GIP response in seven prepubertal lean and 11 prepubertal obese children and in 14 lean adolescents and 10 obese adolescents. Plasma glucose was acutely raised to 11 mM by infusing i.v. glucose and kept at this concentration for 180 min. Each subject ingested oral glucose (30 g) at 120 min, and the glucose infusion was adjusted to maintain the plasma glucose plateau. Basal insulin and C-peptide concentrations and insulin secretion rates (calculated by the deconvolution method) were significantly greater in obese children compared with lean children (p < 0.001). Similarly, during the first 120 min of the clamp, insulin secretion rates were higher in obese than lean children. After oral glucose, plasma insulin, C-peptide, and insulin secretion rates further increased in all four groups. This incretin effect was 2-fold greater in obese versus lean adolescents (p < 0.001). Circulating plasma GIP concentrations were similar at baseline in all four groups and remained unchanged during the first 120 min of the clamp. After oral glucose, plasma GIP concentrations rose sharply in all groups (p < 0.002). Of note, the rise in GIP was similar in both lean and obese children. In conclusion, under conditions of stable hyperglycemia, the ingestion of a small amount of glucose elicited equivalent GIP responses in both lean and obese children. However, despite similar GIP responses, insulin secretion was markedly augmented in obese adolescents. Thus, in juvenile obesity, excessive alimentary beta-cell stimulation may be independent of the increased release of GIP.

Ultrawideband radiation and pentylenetetrazol-induced convulsions in rats.

New non-ionizing pulsed systems using ultrawideband (UWB) require safety assessment before they can be used by either military or civilian communities. The development of directed energy weaponry intended for use against electronically vulnerable targets, as well as ground-probing radar systems, have used fast-rise-time high-peak-power electromagnetic pulses characteristic of UWB emitters. It has been postulated that these ultrashort pulses might produce electromagnetic transients resulting in tissue damage. Several challenges to this notion have been posed, however. One report found that rats exposed to UWB after receiving a convulsant drug tended toward longer latency to the onset of convulsions than the no-exposure group. Although not statistically significant, the presence of this trend prompted the present study. An ED99 dose of the convulsant pentylenetetrazol (PTZ) or saline was given just before UWB or sham exposure and resultant seizure activity was recorded. The data from the current study show no effect of UWB exposure on PTZ-induced seizure activity, thereby not supporting the tissue damage concerns, at least for the exposure parameters used here.

Community-based screening for childhood lead poisoning. Identification of risk factors and susceptible populations in Duluth.

The purpose of this matched case-controlled study was to identify local risk factors and susceptible populations for childhood lead poisoning in Duluth, Minnesota. We mailed questionnaires to the parents of 20 children with known elevated capillary lead levels > or = 10 micrograms/dL; 76 age-matched controls had capillary lead levels < 10 micrograms/dL. The study identified these risk factors for elevated capillary lead levels in children: not attending daycare, having nonwhite parents, living in rental property in central Duluth, and moving with family three or more times in the previous five years. We conclude that these risk factors are related to socioeconomics. Minority children and children living in poverty in the Duluth area should be screened for lead poisoning according to the Centers for Disease Control and Prevention screening guidelines for high-risk lead exposure.

Effect of once weekly treatment with 3,4-methylenedioxymethamphetamine on schedule-controlled behavior in rats.

The present study examined the effects of 3,4-methylenedioxymethamphetamine (MDMA), before and after once a week dosing, on the behavior of rats responding under a fixed ratio 20 schedule of reinforcement. Acutely, cumulative doses of MDMA dose-dependently decreased responding when compared to a series of water injections. Rats were then separated into two groups, one of which received only weekly MDMA ('paired') while the other received an additional injection of water each week ('unpaired'). Weekly dosing with MDMA resulted in significantly increased responding at low doses in the paired group but not in the unpaired group. When water injections were readministered there was a significant increase in responding in both groups. During the weekly regimen, locomotor activity also increased significantly over time after both water and MDMA injections. In conclusion, it appears that even weekly dosing with a small amount of MDMA can have long-lasting effects that are manifested in both operant and spontaneous behavior and that may be mediated by a conditioning mechanism.

Risperidone treatment of children and adolescents with pervasive developmental disorders: a prospective open-label study.

OBJECTIVE: To investigate the short-term safety and efficacy of risperidone in the treatment of children and adolescents with pervasive developmental disorders. METHOD: This was a 12-week, prospective, systematic, open-label trial that included 18 subjects (15 boys and 3 girls) with a mean age of 10.2 +/- 3.7 years. The sample included 11 subjects with autistic disorder, 3 with Asperger's disorder, 1 with childhood disintegrative disorder, and 3 with pervasive developmental disorder not otherwise specified. Fourteen subjects had comorbid mental retardation. Behavioral ratings were obtained during two baseline visits and again after 12 weeks of risperidone treatment. RESULTS: The optimal dose of risperidone for the 18 subjects was 1.8 +/- 1.0 mg/day. On the basis of the global improvement item of the Clinical Global Impression Scale, 12 of 18 subjects were considered responders. Significant improvement was seen in measures of interfering repetitive behavior, aggression and impulsivity, and some elements of impaired social relatedness. The most common side effect was weight gain (range 10 to 35 lb). CONCLUSIONS: These preliminary results suggest that risperidone may be effective for improving interfering behavioral symptoms in some children and adolescents with pervasive developmental disorders. Double-blind, placebo-controlled studies are needed before definitive statements of safety and efficacy can be made.

Co-existence of severe insulin resistance and hyperinsulinaemia in pre-adolescent obese children.

To determine the time course of changes in insulin action and secretion that occur early during the development of obesity, we studied children before the onset of puberty. The reason for choosing the prepubertal stage of development is that it is metabolically characterized by both a high sensitivity to insulin and low glucose stimulated insulin responses. Fifteen obese preadolescents (8 male/7 female, age 10 +/- 0.4 years, body mass index (BMI) 31 +/- 1.2 kg/m2 Tanner Stage I) with a duration of obesity of less than 5 years and 10 non-obese preadolescents (6 male/4 female, age 10 +/- 0.4 years, BMI 18 +/- 0.9 kg/m2) matched for gender were studied. In a cross-sectional analysis, we compared responses in obese preadolescents, with those in obese adolescents and obese adults with a longer duration of obesity. The euglycaemic hyperinsulinaemic clamp with 1-13C-glucose (Hot Ginf) and indirect calorimetry were used to quantitate insulin action and the hyperglycaemic clamp used to assess beta-cell function. Insulin-stimulated glucose uptake measured at two physiological levels of hyperinsulinaemia (approximately 180 and 480 pmol) was reduced by 20 and 45% in all three groups of obese compared to non-obese subjects (p < 0.01). Defects in oxidative and non-oxidative glucose metabolism were observed in all three groups of obese subjects at the higher insulin infusion rate. The ability of insulin to inhibit lipid oxidation was impaired in all three obese groups at both levels of hyperinsulinaemia. Increases in basal and glucose-stimulated insulin levels during the hyperglycaemic clamp mirrored the reductions in glucose uptake during the insulin clamp in all obese groups. These results indicate that insulin resistance and hyperinsulinaemia co-exist in preadolescent children with moderate to severe obesity.

Fat distribution and cardiovascular risk factors in obese adolescent girls: importance of the intraabdominal fat depot.

The regional distribution of body fat has repeatedly been found to be a significant and independent risk factor for cardiovascular disease in both obese men and women. To determine whether abnormalities in the lipid-lipoprotein profile and systolic and diastolic blood pressure are related to specific fat depots early in the course of obesity, we used magnetic resonance imaging to measure accurately intraabdominal and subcutaneous fat masses in 14 obese [body mass index (BMI; in kg/m2) 30 +/- 1.3] and 10 nonobese (BMI: 21 +/- 0.5) adolescent girls matched for age and Tanner stage of development. Intraabdominal and subcutaneous fat depots were two- to threefold greater in obese than in nonobese girls (P < 0.01). Total cholesterol, triacylglycerol, low-density-lipoprotein (LDL) cholesterol, basal insulin, and systolic and diastolic blood pressure were significantly higher in obese adolescent girls than in control subjects. In obese girls, intraabdominal fat but not BMI or waist-to-hip ratio was highly correlated with basal insulin (r = 0.55, P < 0.04), triacylglycerols (r = 0.53, P < 0.03), and high-density-lipoprotein (HDL) cholesterol (r = -0.54, P < 0.04). Femoral adipose tissue was inversely related to triacylglycerol (r = -0.51) and LDL cholesterol (r = -0.56, P < 0.05) concentrations in obese girls. The study indicates that early in the natural history of obese adolescent girls, cardiovascular risk factors are related to the amount of intraabdominal fat.

Time course of discriminative stimulus effects of bretazenil and chlordiazepoxide in rats.

The time course of the discriminative stimulus effects of a benzodiazepine partial agonist, bretazenil, and a benzodiazepine full agonist, chlordiazepoxide, were determined in rats after administration of two doses of either drug. As in man, bretazenil was considerably shorter-acting than chlordiazepoxide, with 0% drug-appropriate responding at the 2-h time point after the training dose of 7 mg/kg and < 20% drug-appropriate responding at 9 h after the 14 mg/kg dose. With chlordiazepoxide, responding on the water-appropriate lever did not occur in all rats until 7 h after administration of the training dose of 7 mg/kg, compared to 17 h after administration of 14 mg/kg. Although there was considerable individual variability with both drugs, it would appear that the drug discrimination procedure can be a valuable tool for studying the time course of the interoceptive effects of psychoactive drugs.

Development of pre-isogenic lines for rice blast-resistance by marker-aided selection from a recombinant inbred population.

To increase the available set of near-isogenic lines (NILs) for blast-resistance in rice, we have developed a general method for establishing NILs from populations of fixed recombinants that have been used for gene mapping. We demonstrated the application of this method by the selection of lines carrying genes from the rice cultivar Moroberekan. Moroberekan is a West African japonica cultivar that is considered to have durable resistance to rice blast. Multiple genes from Moroberekan conferring complete and partial resistance to blast have previously been mapped using a recombinant inbred (RI) population derived from a cross between Moroberekan and the highly and broadly susceptible indica cultivar CO39. To analyze individual blast-resistance genes, it is desirable to transfer them individually into a susceptible genetic background. This RI population, and the associated data sets on blast reaction and restriction fragment length polymorphism (RFLP) genotypes, were used for selection of lines likely to carry individual blast-resistance genes and a minimum number of chromosomal segments from Moroberekan. Because skewed segregation in the RI population favored CO39 (indica) alleles, resistant lines carrying 8.7-17.5% of Moroberekan alleles (the proportion expected after two or three backcrosses) could be selected. We chose three RI lines carrying different complete resistance genes to blast and two RI lines carrying partial resistance genes to blast as potential parents for the development of NILs. These lines were subjected to genetic analysis, which allowed clarification of some issues that could not be resolved during the initial gene-mapping study.

Chronic bretazenil produces tolerance to chlordiazepoxide, midazolam, and abecarnil.

The purpose of the present study was to determine if chronic treatment with a nonsedative benzodiazepine partial agonist would confer tolerance to the rate-decreasing effects of other benzodiazepine ligands in a fixed-interval procedure in rats. A separate group of rats was treated chronically with the sedative benzodiazepine full agonist, chlordiazepoxide, for comparison. It was hypothesized that tolerance would develop rapidly to chlordiazepoxide due to loss of reinforcement density at rate-decreasing doses and that there would probably be cross-tolerance to other rate-decreasing benzodiazepine ligands such as midazolam and abecarnil. Because bretazenil does not produce rate decreases, however, it was not expected that tolerance would be found to chlordiazepoxide, midazolam, or abecarnil. After 8-12 weeks of chronic treatment with either chlordiazepoxide or bretazenil, however (final dose of benzodiazepine = 30 mg/kg/day), tolerance was found to the rate-decreasing effects of chlordiazepoxide, midazolam, and abecarnil in both groups. It is concluded that such tolerance was most likely due to a saturation of benzodiazepine receptors by this high-affinity partial agonist.

A behavioral comparison of Nexus, cathinone, BDB, and MDA.

The effects of 4-bromo-2,5-dimethoxyphenethylamine (Nexus), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxyphenyl-2-butanamine (BDB), and cathinone were studied in the newly hatched chicken and compared to the effects of d-amphetamine and three hallucinogens in the same species. Cathinone, a psychomotor stimulant in man (6), produced effects that were qualitatively similar to effects seen after administration of d-amphetamine (i.e., distress vocalization, wing extension, inability to stand, and loss of righting reflex). BDB, a compound with unknown activity in man, and two known hallucinogens, Nexus (5) and MDA (1), produced effects in the chicken that are common to both stimulants and hallucinogens in this species. For example, both MDA and BDB produced abnormal body posture that was identical to that reported after administration of hallucinogens such as lysergic acid diethylamide (LSD) and harmine (11). Nexus, on the other hand, produced rigid penguin-like posture, an effect seen in the chicken after administration of another hallucinogen, mescaline (12). BDB also produced bursting forward movements, an effect commonly observed after LSD and harmine. Our findings suggest that the young chicken can be used as an alternative, nonmammalian, model for predicting classification of new compounds.

Structure-activity relationships of BDB and its monomethyl and dimethyl derivatives.

The purpose of the present study was to evaluate the behavioral effects of 3,4-methylenedioxyphenyl-2-butanamine (BDB), N-methyl BDB (MBDB), and N,N-dimethyl BDB (MMBDB) in the newly hatched chicken. The primary amine, BDB, produced effects that are commonly seen in the chicken after administration of both hallucinogens and psychomotor stimulants (i.e., distress vocalization, tremor, and wing extension). It also produced abnormal body posture and bursting forward locomotion, effects elicited only by hallucinogens. Loss of righting reflex also occurred at the highest (16 mg/kg) dose of BDB, and this effect is typical of d-amphetamine but has not been reported for hallucinogens. The monomethylated derivative of BDB, MBDB, was less potent than BDB, and the N,N-dimethyl analogue of BDB, MMBDB, had no effect on behavior at the doses tested.

Behavioral and developmental effects of two 3,4-methylenedioxymethamphetamine (MDMA) derivatives.

The effects of 3,4-methylenedioxymethamphetamine (MDMA or 'ecstacy') and two structurally related compounds, N-methyl-1-(3,4-methylenedioxyphenyl)-1-ethanamine (MDM1EA) and N-methyl-1-(3,4-methylenedioxyphenyl)-3-butanamine (HMDMA) were examined in two preparations: (i) a drug discrimination procedure in MDMA-trained rats and (ii) the chicken embryo, for determination of the direct effects of these compounds on the developing organism. The highest doses of MDM1EA and HMDMA partially substituted for MDMA, whereas higher (30-60 mg/kg) doses of HMDMA evoked clonic seizures in a separate group of rats. In chicken embryos MDMA had no effect on body, brain or liver weight, while the highest dose of MDM1EA decreased body weight and the 2 lowest doses of HMDMA increased body weight. All doses of HMDMA decreased liver weight (expressed as % body weight) when compared with contemporaneous water-treated controls. Taken together, the results of these experiments suggest that structurally related compounds share some stimulus properties with MDMA and may therefore share abuse liability. Furthermore, both MDMA-related compounds produced adverse effects on the developing organism, whereas MDMA did not.

Chlordiazepoxide, but not bretazenil, produces acute dependence, as evidenced by disruptions in schedule-controlled behavior.

The purpose of the present study was to determine whether the full benzodiazepine (BDZ) agonist chlordiazepoxide (CDAP) and the partial BDZ agonist bretazenil would produce acute dependence in rats, as evidenced by disruptions in fixed-interval responding during precipitated abstinence withdrawal. Doses of CDAP and bretazenil administered acutely were 10, 75, and 100 mg/kg; flumazenil (1-56 mg/kg) was administered 1, 2, 4, or 18 h later. Withdrawal, defined as a significant decrease in fixed-interval responding, was only seen when a high dose of flumazenil was administered 18 h after 100 mg/kg of CDAP. These results support those of others (5) who found that high (75-450 mg/kg) doses of CDAP were required to produce acute physical dependence. That bretazenil did not produce acute physical dependence supports the findings of others (20,23) who report that chronic administration of bretazenil does not result in physical dependence.