Analysis of body condition indices reveals different ecotypes of the Antillean manatee.

Assessing the body condition of wild animals is necessary to monitor the health of the population and is critical to defining a framework for conservation actions. Body condition indices (BCIs) are a non-invasive and relatively simple means to assess the health of individual animals, useful for addressing a wide variety of ecological, behavioral, and management questions. The Antillean manatee (Trichechus manatus manatus) is an endangered subspecies of the West Indian manatee, facing a wide variety of threats from mostly human-related origins. Our objective was to define specific BCIs for the subspecies that, coupled with additional health, genetic and demographic information, can be valuable to guide management decisions. Biometric measurements of 380 wild Antillean manatees captured in seven different locations within their range of distribution were obtained. From this information, we developed three BCIs (BCI1 = UG/SL, BCI2 = W/SL3, BCI3 = W/(SL*UG2)). Linear models and two-way ANCOVA tests showed significant differences of the BCIs among sexes and locations. Although our three BCIs are suitable for Antillean manatees, BCI1 is more practical as it does not require information about weight, which can be a metric logistically difficult to collect under particular circumstances. BCI1 was significantly different among environments, revealing that the phenotypic plasticity of the subspecies have originated at least two ecotypes-coastal marine and riverine-of Antillean manatees.

Thermoregulation in larval aggregations of carrion-feeding blow flies (Diptera: Calliphoridae).

The growth and development of carrion-feeding calliphorid (Diptera: Calliphoridae) larvae, or maggots, is of great interest to forensic sciences, especially for estimation of a postmortem interval (PMI). The development rate of calliphorid larvae is influenced by the temperature of their immediate environment. Heat generation in larval feeding aggregations (=maggot masses) is a well-known phenomenon, but it has not been quantitatively described. Calculated development rates that do not include internally generated temperatures will result in overestimation of PMI. Over a period of 2.5 yr, 80 pig, Sus scrofa L., carcasses were placed out at study sites in north central Florida and northwestern Indiana. Once larval aggregations started to form, multiple internal and external temperatures, and weather observations were taken daily or every few days between 1400 and 1800 hours until pupation of the larvae. Volume of each aggregation was determined by measuring surface area and average depth. Live and preserved samples of larvae were taken for species identification. The four most common species collected were Lucilia coeruleiviridis (=Phaenicia) (Macquart) (77%), Cochliomyia macellaria (F.) (8.3%), Chrysomya rufifaces (Macquart) (7.7%), and Phormnia regina (Meigen) (5.5%). Statistical analyses showed that 1) volume of a larval mass had a strong influence on its temperature, 2) internal temperatures of masses on the ground were influenced by soil temperature and mass volume, 3) internal temperatures of masses smaller than 20 cm3 were influenced by ambient air temperature and mass volume, and 4) masses larger than 20 cm3 on the carcass had strongly regulated internal temperatures determined only by the volume of the mass, with larger volumes associated with higher temperatures. Nonsignificant factors included presence of rain or clouds, shape of the aggregation, weight of the carcass, species composition of the aggregation, time since death, or season.

Contextualizing counterintuitiveness: how context affects comprehension and memorability of counterintuitive concepts.

A number of anthropologists have argued that religious concepts are minimally counterintuitive and that this gives them mnemic advantages. This paper addresses the question of why people have the memory architecture that results in such concepts being more memorable than other types of concepts by pointing out the benefits of a memory structure that leads to better recall for minimally counterintuitive concepts and by showing how such benefits emerge in the real-time processing of comprehending narratives such as folk tales. This model suggests that memorability is not an inherent property of a concept; rather it is a property of the concept, the context in which the concept is presented, and the background knowledge that the comprehendor possesses about the concept. The model predicts how memorability of a concept should change if the context containing the concept were changed. The paper also presents the results of experiments carried out to test these predictions.

Volume of Larvae Is the Most Important Single Predictor of Mass Temperatures in the Forensically Important Calliphorid, Chrysomya megacephala (Diptera: Calliphoridae).

Calliphorid species form larval aggregations that are capable of generating heat above ambient temperature. We wanted to determine the relationship between volume, number of larvae, and different combinations of instars on larval mass heat generation. We compared different numbers of Chrysomya megacephala (F.) larvae (40, 100, 250, 600, and 2,000), and different combinations of instars (∼50/50 first and second instars, 100% second instars, ∼50/50 second and third instars, and 100% third instars) at two different ambient temperatures (20 and 30 °C). We compared 13 candidate multiple regression models that were fitted to the data; the models were then scored and ranked with Akaike information criterion and Bayesian information criterion. The results indicate that although instar, age, treatment temperature, elapsed time, and number of larvae in a mass were significant, larval volume was the best predictor of larval mass temperatures. The volume of a larval mass may need to be taken into consideration for determination of a postmortem interval.

Development of the Oriental Latrine Fly, Chrysomya megacephala (Diptera: Calliphoridae), at Five Constant Temperatures.

Chrysomya megacephala (Fabricius) is a forensically important fly that is found throughout the tropics and subtropics. We calculated the accumulated development time and transition points for each life stage from eclosion to adult emergence at five constant temperatures: 15, 20, 25, 30, and 35 °C. For each transition, the 10th, 50th, and 90th percentiles were calculated with a logistic linear model. The mean transition times and % survivorship were determined directly from the raw laboratory data. Development times of C. megacephala were compared with that of two other closely related species, Chrysomya rufifacies (Macquart) and Phormia regina (Meigen). Ambient and larval mass temperatures were collected from field studies conducted from 2001-2004. Field study data indicated that adult fly activity was reduced at lower ambient temperatures, but once a larval mass was established, heat generation occurred. These development times and durations can be used for estimation of a postmortem interval (PMI).

Statin discontinuation and mortality in an older adult population with traumatic brain injury: A four-year, multi-centre, observational cohort study.

INTRODUCTION: Statin discontinuation has been investigated in a wide range of diseases and injuries, but there is a paucity of data in the older adult population with traumatic brain injury (TBI). The purpose of this study was to re-examine the extent to which early discontinuation of pre-injury statin (PIS) therapy increases the risk of poor patient outcomes in older adult patients suffering a TBI. METHODS: This was a retrospective observational cohort study of adult trauma patients with a blunt TBI across three trauma centres over four years. Patients were excluded because of no PIS use, age <55years, or a hospital length of stay (LOS) less than three days. Patients found to be intentionally discontinued from statin therapy within 48h of hospital admission for injury-related reasons were excluded. The primary and secondary outcomes were in-hospital mortality and a hospital LOS ≥1 week. Outcomes were analysed using logistic regression. RESULTS: There were 266 patients in the continuation group, and 131 in the discontinuation group. The statin discontinuation group had a significantly higher proportion of patients with a moderate or severe head injury, intubation in emergency department (ED), and disposition to the intensive care unit or operating room. Overall, 23 (6%) patients died while in the hospital. After adjusting for ED Glasgow coma scale, the odds of dying in the hospital were not significantly larger for patients having been discontinued from PIS, compared to those who were continued (OR=1.75, 95%CI=0.71-4.31, p=0.22). Among patients who received an in-hospital statin, the median (interquartile range) time between hospital admission and first administration of statin medication did not differ between patients who died and those who survived (22.8h [10.96-28.91] vs. 22.9h [11.67-39.80], p=0.94). There were no significant differences between study groups in the proportion of patients with a hospital length of stay >1 week (continuation=29% vs. discontinuation=36%, p=0.19). CONCLUSION: We did not observe a significantly increased odds of in-hospital mortality following PIS discontinuation, compared to PIS continuation, in an older adult population with TBI. It remains to be seen whether statin discontinuation is a proxy variable for injury severity, or whether it exerts deleterious effects after injury.

Extrapyramidal side effects in chlorpromazine recipients: emergence according to benztropine prophylaxis.

The frequency of extrapyramidal symptoms (EPS) attributed to chlorpromazine among 86 patients who received benztropine for the prevention of EPS (9.3%) was similar to that of the 568 patients who received chlorpromazine alone (10.6%). The data in this small sample indicated that the prophylactic use of benztropine had no effect in reducing the rate of EPS.

Hypotension due to chlorpromazine. Relation to cigarette smoking, blood pressure, and dosage.

The frequency of hypotension attributed to orally administered chlorpromazine hydrochloride was compared among 187 nonsmokers, 223 "light" smokers, 87 "intermediate" smokers, and 18 "heavy" smokers. Hypotension attributed to the drug occurred in10%, 8%, 5% and 0%, respectively. Other factors found to be independently related to hypotension were high diastolic blood pressure on admission and high dosage of chlorpromazine. The results suggest that smoking status, dosage, and blood pressure must be evaluated in order to estimate the likelihood that a patient may become hypotensive after receiving chlorpromazine.

Human variability in hepatic glutathione S-transferase-mediated conjugation of aflatoxin B1-epoxide and other substrates.

Hepatic cytosolic fractions prepared from 14 human donors were analysed for glutathione S-transferase (GST) activity towards synthetic aflatoxin B1-8,9-epoxide (AFBO). In addition, GST-AFBO activity of pooled human liver cytosols was compared with rat, hamster, and mouse liver cytosol GST-AFBO activities. Consistent with previous studies, human liver cytosolic GSTs exhibited little activity towards AFBO. Hepatic GST-AFBO activities of rat, hamster, and mouse were 48-, 56-, and 312-fold greater, respectively, than observed for human liver using synthetic AFBO, and 70-, 465-, and 3545-fold greater, respectively, than observed for human liver using microsomally-generated AFBO. Furthermore, there was a 58-fold variation in hepatic GST-AFBO activities among the 14 human samples using synthetic AFBO as a substrate. Large interindividual variations were also observed with respect to GST activities towards bromosulfophthalein (BSP, 92-fold variation) and 3,4-dichloronitrobenzene (DCNB, 36-fold variation). Lesser interindividual variations were observed with respect to human liver GST activities towards benzo(a)pyrene-4,5-oxide (BaPO, 9-fold variation), 1-chloro-2,4-dinitrobenzene (CDNB, 8.5-fold variation), cumene hydroperoxide (CHP, 5-fold variation), and p-nitrophenyl acetate (NPA, 4-fold variation). No correlation was found among GST-AFBO activities and the presence of GST mu as determined by enzyme-linked immunosorbent assay (ELISA) or GST-trans-stilbene oxide (TSO) catalytic activity. Our observations support those of previous studies indicating that human liver cytosolic GSTs are relatively ineffective at conjugating AFBO. Furthermore, our data indicate that humans exhibit large inter-individual differences with respect to hepatic cytosolic GST conjugation of AFBO and certain other GST substrates.

Cigarette smoking in relation to the risk of myocardial infarction in young women. Modifying influence of age and predisposing factors.

We evaluated the relation between myocardial infarction (MI) and cigarette smoking in women 30 to 49 years of age. Among 318 women who had survived recent first infarctions and 1272 age-matched controls, the proportions of cigarette smokers were 83% and 54%, respectively (p < 0.001). The estimated relative risk rose progressively with amount smoked: compared with women who had never smoked, the estimate was 1.8 for smokers of less than 15 cigarettes per day and 6.9 for smokers of 35 or more cigarettes per day. At each level of smoking, the relative increase in risk was greater at younger ages and among those not apparently predisposed from other factors. Although MI is a rare disease in young women, our data indicate that the risks faced by those who smoke heavily are appreciable.

Evaluation of haptoglobin phenotype 0-0 in cirrhotic and non-cirrhotic hospital populations.

The haptoglobin phenotypes of 3,332 individuals, consisting of 2,930 caucasians and 402 negroes living in the greater Boston area, were determined. Of these, 3,222 were hospitalized medical patients fully documented regarding diagnoses. One hundred and twentyeight of the total population studied were shown to exhibit starch gel anhaptoglobinaemia (3.7%). Re-evaluation on acrylamide gel of 118 0-0 samples revealed that the majority (94%) were derived from patients exhibiting hypohaptoglobinaemia rather than anhaptoglobinaemia.

Effects of dietary oltipraz and ethoxyquin on aflatoxin B1 biotransformation in non-human primates.

Following aflatoxin B1 (AFB) exposure, rats readily develop liver tumors. However, treatment of rats with a variety of compounds, including the synthetic dithiolthione oltipraz and the antioxidant ethoxyquin, protects these rodents from AFB-induced hepatocarcinogenesis. Several epidemiological studies strongly suggest that AFB is also a causative agent of liver cancer in humans. However, relatively little is known about the efficacy of cancer chemoprevention in human and non-human primates. To this end, we examined the effects of chemopreventive agents on AFB metabolism in non-human primates. Hepatic aflatoxin B1 metabolism profiles of macaque (Macaca nemestrina) and marmoset (Callithrix jacchus) monkeys were determined and compared to humans. Quantitatively, the oxidative metabolism of this mycotoxin was similar in the three primate species. In contrast to macaques, both humans and marmosets lacked AFB-glutathione conjugating activity. It was concluded that marmosets resembled human AFB metabolism more closely than the macaques, and therefore, marmoset monkeys were chosen for this study. Eleven adult male marmosets were randomly assigned to three groups. Animals received the synthetic dithiolthione oltipraz, the antioxidant ethoxyquin, or vehicle only. In addition, two single doses of AFB were also administered orally before and after animals were treated with aforementioned compounds. Both oltipraz and ethoxyquin induced aflatoxin B1-glutathione conjugating activity in the livers of some but not all marmosets. In addition, 10 microM oltipraz inhibited cytochrome P450-mediated activation of AFB to the ultimate carcinogenic metabolite, aflatoxin B1-8,9-epoxide, in vitro, up to 51%. Furthermore, animals treated in vivo with oltipraz, but not ethoxyquin, exhibited a significant reduction (53% average) in AFB-DNA adduct formation relative to the control animals (p < 0.05). Together, our data suggest that chemoprevention is also effective in primates; however, most likely to a lesser degree than in rodents.

Blurring artifacts in megavoltage radiography with a flat-panel imaging system: comparison of Monte Carlo simulations with measurements.

Originally designed for use at medical-imaging x-ray energies, imaging systems comprising scintillating screens and amorphous Si detectors are also used at the megavoltage photon energies typical of portal imaging and industrial radiography. While image blur at medical-imaging x-ray energies is strongly influenced both by K-shell fluorescence and by the transport of optical photons within the scintillator layer, at higher photon energies the image blur is dominated by radiation scattered from the detector housing and internal support structures. We use Monte Carlo methods to study the blurring in a notional detector: a series of semi-infinite layers with material compositions, thicknesses, and densities similar to those of a commercially available flat-panel amorphous Si detector system comprising a protective housing, a gadolinium oxysulfide scintillator screen, and associated electronics. We find that the image blurring, as described by a point-spread function (PSF), has three length scales. The first component, with a submillimeter length scale, arises from electron scatter within the scintillator and detection electronics. The second component, with a millimeter-to-centimeter length scale, arises from electrons produced in the front cover of the detector. The third component, with a length scale of tens of centimeters, arises from photon scatter by the back cover of the detector. The relative contributions of each of these components to the overall PSF vary with incident photon energy. We present an algorithm that includes the energy-dependent sensitivity and energy-dependent PSF within a ray-tracing formalism. We find quantitative agreement (approximately 2%) between predicted radiographs with radiographs of copper step wedges, taken with a 9 MV bremsstrahlung source and a commercially available flat-panel system. The measured radiographs show the blurring artifacts expected from both the millimeter-scale electron transport and from the tens-of-centimeters length scale arising from the scattered photon transport. Calculations indicate that neglect of the energy-dependent blurring would lead to discrepancies in the apparent transmission of these wedges of the order of 9%.

Nutritional support of the critically ill and injured patient.

The understanding of the importance of nutrition, particularly in the critically ill patient, is based on the known physiologic consequences of malnutrition. It includes respiratory muscle function, cardiac function, the coagulation cascade balance, electrolyte and hormonal balance, and renal function. Nutrition affects emotional and behavioral responses, functional recovery, and the overall cost of health care. The need to identify and treat the malnourished or potentially malnourished patient is a critical aspect of patient management. Much is known of catabolic and hypermetabolic state caused by trauma and burns. The response to injury needs to be mediated. There is much to learn about the intervention of that response through adjuvant nutritional therapy.

Development and cross-validation of a short form impairment index.

The Brain Age Quotient (BAQ) is an actuarial combination of four Halstead-Reitan neuropsychology test battery scores (Category errors. Tactual Performance Test- Total Time, Tactual Performance Test-Location Score and Trails-B Score) and two performance subtests for the Wechsler Adult Intelligence Scale (Block Design and Digit Symbol). The present studies investigated the value of a short form of the BAQ, the Short Form Impairment Index (SFII), composed of the Trails-B Score and two subtests of the Wechsler and also twice cross-validated the short form. Statistical analysis yielded a Pearson r =.90, for both the initial study and each of the cross-validations. Further research and clinical considerations are discussed.

Continuous absorbable suture pattern in the closure of ventral midline abdominal incisions in horses.

A retrospective study was performed to evaluate the healing of ventral midline abdominal incisions, closed with a simple continuous suture pattern using absorbable suture material, in 139 horses and foals. Dehiscence and incisional hernia developed separately in two horses. The low incidence of dehiscence and incisional hernia, compared with their reported incidence following the use of interrupted suture repair, leads the authors to recommend this alternative method of abdominal incision closure in horses. The security of closure is not sacrificed and the advantages of a rapid closure are desirable.

Vascular anatomy and surgical technique for bilateral adrenalectomy in the equid.

The vascular anatomy of the adrenal glands and a surgical technique for bilateral adrenalectomy in the equid are described. Bilateral adrenalectomy was performed in six ponies and one horse via bilateral transcostal retroperitoneal approaches through the 18th rib during a single anesthetic period. Complications included hemorrhage from the right side only and pneumothorax which usually occurred on the right side. One pony died as a result of the surgical technique. Maintenance of adrenal function was accomplished with desoxycorticosterone pivilate and prednisolone.

Cortisol (hydrocortisone) disappearance rate and pathophysiologic changes after bilateral adrenalectomy in equids.

Six ponies and 1 horse were bilaterally adrenalectomized (BADX). The survival time of 2 of the 7 animals after BADX was 24 and 72 hours without supplemental corticosteroids. The cause of death was not related to the surgical technique. The biological half-life of cortisol (hydrocortisone) was estimated to be 2.1 +/- 0.6 hours. The disappearance of cortisol in the horse was found to be biphasic, composed of redistribution and elimination phases. Pathophysiologic changes (ie, increased serum sodium and chloride, increased PCV, and decreased serum potassium) similar to those seen in other species after BADX were found. Clearance of electrolytes was calculated, using the creatinine clearance method. These values were inversely correlated with the changes seen in serum electrolytes.

Sodium retention and cortisol (hydrocortisone) suppression caused by dexamethasone and triamcinolone in equids.

Three ponies and 1 horse were bilaterally adrenalectomized (BADX). The initial hypoadrenal episode after BADX was reversed with 20 mg of dexamethasone (DXM) IM (n = 2) or 20 mg of triamcinolone (TMC) IM (n = 2). Nine hypoadrenal crises were reversed with 20 mg of DXM given IM (n = 4) or 20 mg of TMC given IM (n = 5). Sodium and chloride retention and potassium excretion were documented based on changes in serum electrolytes and urinary excretion. Eight intact adult horses were randomly assigned to 2 groups to study the effects of a single IM injection of DXM (0.044 mg/kg of body weight) or TMC (0.044 mg/kg). Cortisol (hydrocortisone) suppression was found to be maximal (nondetectable amounts of cortisol) by 12 hours in both groups. Cortisol was again detectable in the DXM group at 24 hours after injection and was at pretreatment values at 168 hours. Cortisol was not detectable in the TMC group for 192 hours and did not reach pretreatment values until 336 hours. The duration of the gluconeogenic effect was compared with the duration of cortisol suppression exerted by DXM and TMC in these intact animals. Assuming that the decrease in plasma glucose coincides with the decrease in glucocorticoid activity of the respective steroid, a relative hypoadrenocortical state was found in the animals treated with DXM between the 2nd and 7th day after treatment, whereas this state occurred between the 6th and 14th day after treatment with TMC.