A double-spike MC TIMS measurement procedure for low-amount Ca isotopic analysis of limited biological tissue samples

The application of Ca isotopic analysis in biomedical studies has great potential to identify changes in Ca metabolism and bone metabolism. Reliable measurement of Ca isotope-amount ratios is challenging considering limited Ca amounts and significant procedural blank levels. In this study, Ca purification was performed using the DGA Resin, optimized for low procedural blanks and separation of Ca from matrix elements and isobaric interferences (Na, Mg, K, Ti, Fe, Ba), while maintaining quasi-quantitative recoveries which are sufficient since a ⁴²Ca-⁴⁸Ca double-spike (DS) was applied. Ca isotopic analysis was performed using multicollector thermal ionization mass spectrometry (MC TIMS). The obtained procedural Ca blank of ≤10 ng enables processing of limited Ca amounts down to 670 ng. Data reduction of the measured Ca isotope-amount ratios was performed using an in-house developed software solving the DS algorithm. Data quality was improved by extension of equilibration time of the sample-DS mixture and implementation of a normalization strategy for raw isotopic data. The reported δ(⁴⁴Ca/⁴⁰Ca)_{NIST SRM 915a} of NIST SRM 915a processed as a sample was found to be 0.01 ‰ ± 0.08 ‰ (2 SD, n = 15). Ca isotope-amount ratios of the reference material NIST SRM 1400 (bone ash), NIST SRM 1486 (bone meal), GBW07601 (human hair), and IAPSO (seawater) were in good agreement within uncertainty with literature data. Novel data on additional reference materials for biological tissues (hair) is presented, which might indicate a potential fractionation of Ca incorporated into hair tissue when compared to the blood pool.

An exploratory study of clinical and physiological correlates of problematic social media use in adolescents

Prior validation studies of the Bergen Social Media Addiction Scale (BSMAS) demonstrate its utility for identifying problematic social media use in adolescents. There are knowledge gaps regarding the potential clinical and physiological underpinnings of problematic social media use in adolescents. This cross-sectional, single-visit study examined a sample of depressed (n = 30) and healthy (n = 30) adolescents who underwent clinical assessments of depressive symptom severity, bullying, cyberbullying, self-esteem, salivary measures of stress (cortisol and α-amylase) to identify correlates with adolescent and parental reports of the BSMAS. LASSO-penalized multiple linear regression models were implemented. With respect to the adolescent BSMAS scores in all subjects, the risk of problematic social media increased as depressive symptom severity increased. Depressed female adolescents appeared to have a greater risk. Based on parental BSMAS scores, depression status, depressive symptom severity, cyberbullying score, and salivary cortisol significantly predicted problematic social media use. For the depressed sample, the risk of problematic social media use increased as salivary cortisol increased. No significant predictors of problematic social media usage emerged in the healthy control sample. These preliminary results provide novel insights into clinical and physiological characteristics of problematic social media use in adolescents.

Altered markers of stress in depressed adolescents after acute social media use

Social media use (SMU) is an inherent element in the daily life and neurodevelopment of adolescents, but broad concerns exist regarding the untoward effects of social media on adolescents. We conducted a prospective, cross-sectional study that sought to examine the acute effects of SMU on clinical measures and biomarkers of stress in healthy and depressed adolescents. After at least 24 h of abstinence from social media, depressed adolescents (n = 30) and healthy control adolescents (n = 30) underwent baseline clinical assessment of their prior SMU, depressive symptom severity, self-esteem, and exposure to bullying. Participants provided salivary samples that were analyzed for α-amylase and cortisol levels. After 20 min of unsupervised SMU, saliva analyses and clinical assessments were repeated. After 20 min of SMU, salivary cortisol and α-amylase levels were significantly higher in adolescents with depression but not in healthy control adolescents. Furthermore, small but statistically significant changes in depressive symptom severity occurred in all participants. These changes in depressive symptoms were not clinically meaningful. SMU did not significantly change self-esteem measures among participants. Adolescents with depression appeared to have more physiological reactivity after SMU compared with healthy adolescents. Further research should characterize SMU as a clinical dimension and risk factor among adolescents with depression and other psychiatric disorders.

A Different Breed of Wolf: First Known Case of Wolf–Hirschorn Syndrome with Third-degree Atrioventricular Block Requiring Pacemaker Implantation

We describe a case of a 44-year-old male with a history of Wolf–Hirschorn syndrome (WHS) with seizures and mental retardation who was evaluated for what was thought to be a seizure. He was found to be severely bradycardic with a heart rate of 24 bpm. The electrocardiogram revealed third-degree atrioventricular block and he subsequently underwent an uncomplicated single-chamber pacemaker implantation procedure. This is a unique report given its status as the first described case of bradycardic rhythm abnormalities in a patient with WHS.

Interaction between supplemental zinc oxide and zilpaterol hydrochloride on growth performance, carcass traits, and blood metabolites in feedlot steers

Interactive effects of supplemental Zn and zilpaterol hydrochloride (ZH) were evaluated in feedlot steers ( = 40; 652 kg ± 14 initial BW) to determine their impact on feedlot performance, blood constituents, and carcass traits. The study was conducted as a randomized complete block design with a 2 × 2 factorial treatment arrangement. Steers were blocked by BW and randomly assigned to treatments. Factors consisted of supplemental Zn (60 or 300 mg/kg diet DM) and ZH (0 or 8.33 mg/kg) in the diets. For diets supplemented with 300 mg Zn/kg DM, 60 mg Zn/kg was supplemented as zinc sulfate and 240 mg Zn/kg was supplemented as zinc oxide, and the diet was fed for 24 d. Zilpaterol hydrochloride was fed for 21 d followed by a 3-d withdrawal. Cattle were housed in partially covered individual feeding pens equipped with automatic waterers and fence-line feed bunks and were fed once daily for ad libitum intake. Plasma samples were collected on d 0 and 21 to assess changes in Zn, plasma urea nitrogen (PUN), glucose, and lactate concentrations, and serum samples were collected on d 21 to assess IGF-1 concentration. On d 25, cattle were weighed and transported 450 km to a commercial abattoir for harvest; HCW and incidence of liver abscesses were recorded. Carcass data were collected after 36 h of refrigeration. Data were analyzed as a mixed model with Zn, ZH, and Zn × ZH as fixed effects; block as a random effect; and steer as the experimental unit. No interaction or effects of Zn or ZH were observed for IGF-1 concentration, plasma glucose, or lactate concentrations ( ≥ 0.25). No interaction between Zn and ZH was observed for PUN concentration, but PUN decreased with ZH ( < 0.01). There were no effects of ZH or Zn on ADG, DMI, final BW, feed efficiency, HCW, back fat, KPH, quality grade, or incidence of liver abscesses ( > 0.05). Zinc supplementation tended ( = 0.08) to improve the proportion of carcasses grading USDA Choice. Feeding ZH decreased yield grade ( = 0.05) and tended to increase LM area ( = 0.07). In conclusion, increasing dietary concentrations of Zn does not impact response to ZH, but feeding ZH altered circulating concentrations of PUN.

Finding Prospective Mates by the Parasitoid Wasp Urolepis rufipes (Hymenoptera: Pteromalidae)

Cues from emergence sites may be predictive of mating opportunities if potential mates are slow to disperse after emergence, and particularly if emergence sites are clumped, as in the solitary parasitoid wasp Urolepis rufipes Ashmead. Males emerge before females, and the present study suggests that males may use emergence sites of conspecific males to locate mates. In choice experiments, virgin males spent more time on a male-emerged host (a host from which a male had recently emerged) than on a female-emerged host. Relative to when no host was present, virgin males also marked more in the presence of a male-emerged host, but did not mark more in the presence of a female-emerged host. Females, but not other males, are known to be attracted to male marks. Unlike for males, there was no evidence that females distinguished between male-emerged and female-emerged hosts. Virgin females preferred areas where multiple males had marked over areas where a single male had marked. Such areas had more total marks, yet marks per male did not differ between aggregated and solitary males. Thus, through his own attraction to male-emerged hosts and by marking near other males a male may find and attract females, and with no apparent increase in the cost of attraction.

How does active substance use at psychiatric admission impact suicide risk and hospital length-of-stay?

Despite their high prevalence, little is known about the effects of substance use disorders and active substance use on the suicide risk or length-of-stay of psychiatric inpatients. This study examines the relationship between active substance use at the time of psychiatric hospitalization and changes in suicide risk measures and length-of-stay. Admission and discharge ratings on the Suicide Status Form-II-R, diagnoses, and toxicology data from 2,333 unique psychiatric inpatients were examined. Data for patients using alcohol, tetrahydrocannabinol, methamphetamines, cocaine, benzodiazepines, opiates, barbiturates, phencyclidine, and multiple substances on admission were compared with data from 1,426 admissions without substance use. Patients with substance use by toxicology on admission had a 0.9 day shorter length-of-stay compared to toxicology-negative patients. During initial nurse evaluation on the inpatient unit, these patients reported lower suicide measures (i.e., suicidal ideation frequency, overall suicide risk, and wish-to-die). No significant between-group differences were seen at discharge. Patients admitted with a substance use disorder diagnosis had a 1.0 day shorter length-of-stay than those without, while those with a substance use disorder diagnosis and positive toxicology reported the lowest measures of suicidality on admission. These results remained independent of psychiatric diagnosis. For acute psychiatric inpatients, suicide risk is higher and length-of-stay is longer in patients with substance use disorders who are NOT acutely intoxicated compared with patients without a substance use disorder. Toxicology-positive patients are less suicidal on admission and improve faster than their toxicology-negative counterparts. This study gives support to the clinical observation that acutely intoxicated patients may stabilize quickly with regard to suicidal urges and need for inpatient care.

Acromelic frontonasal dysostosis and ZSWIM6 mutation: phenotypic spectrum and mosaicism

Acromelic frontonasal dysostosis (AFND) is a distinctive and rare frontonasal malformation that presents in combination with brain and limb abnormalities. A single recurrent heterozygous missense substitution in ZSWIM6, encoding a protein of unknown function, was previously shown to underlie this disorder in four unrelated cases. Here we describe four additional individuals from three families, comprising two sporadic subjects (one of whom had no limb malformation) and a mildly affected female with a severely affected son. In the latter family we demonstrate parental mosaicism through deep sequencing of DNA isolated from a variety of tissues, which each contain different levels of mutation. This has important implications for genetic counselling.

Generation of neutral atomic beams utilizing photodetachment by high power diode laser stacks

We demonstrate the use of high power diode laser stacks to photodetach fast hydrogen and carbon anions and produce ground term neutral atomic beams. We achieve photodetachment efficiencies of ∼7.4% for H(-) at a beam energy of 10 keV and ∼3.7% for C(-) at 28 keV. The diode laser systems used here operate at 975 nm and 808 nm, respectively, and provide high continuous power levels of up to 2 kW, without the need of additional enhancements like optical cavities. The alignment of the beams is straightforward and operation at constant power levels is very stable, while maintenance is minimal. We present a dedicated photodetachment setup that is suitable to efficiently neutralize the majority of stable negative ions in the periodic table.

Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition

The objective of this study was to evaluate the efficacy of protecting PUFA within ground flaxseed against ruminal biohydrogenation by encapsulating them in a matrix consisting of a 1:1 blend of ground flaxseed and dolomitic lime hydrate (L-Flaxseed). Crossbreed heifers ( = 462, 346 ± 19 kg) were blocked by weight and randomly assigned to pens. Pens were assigned to 1 of 6 dietary treatments in a randomized complete block design. Treatment 1 consisted of a combination of 54.6% steam-flaked corn (SFC), 30.0% wet corn gluten feed, 8.0% roughage, and supplement (0% flaxseed). In treatments 2 and 3, a proportion of SFC was replaced with 3 and 6% flaxseed, respectively; in treatments 4, 5, and 6, SFC was replaced with 2, 4, or 6% L-Flaxseed, respectively. Cattle were fed for 140 or 168 d and then harvested in a commercial abattoir where carcass data were collected. Approximately 24 h after harvest, carcasses were evaluated for 12th-rib fat thickness, KPH, LM area, marbling score, and USDA yield and quality grades. Samples of LM were also obtained for determination of long-chain fatty acid profiles. Cattle that were fed diets with 4 and 6% L-Flaxseed consumed less feed than other treatments ( < 0.05), which adversely affected ADG. Compared with cattle fed 0% flaxseed, cattle in these treatments had lower final BW (18 and 45 kg less for the 4 and 6% L-Flaxseed treatments, respectively), less ADG (0.16 and 0.48 kg/day less for the 4 and 6% L-Flaxseed treatments, respectively), and lower carcass weights, dressing percentages, LM areas, backfat thicknesses, and marbling scores ( < 0.05). The addition of flaxseed or 2% L-Flaxseed did not affect performance or carcass traits ( > 0.05). Supplementation with flaxseed increased ( < 0.05) the concentration of α-linolenic acid (ALA) in meat (0.173, 0.482, 0.743 mg/g for 0, 3, and 6% flaxseed, respectively). Furthermore, proportionate increases in the ALA content of muscle tissue were 47% greater when flaxseed was encapsulated within the dolomitic lime hydrate matrix (0.288, 0.433, 0.592 mg/g for 2, 4, and 6% L-Flaxseed, respectively). Both products showed a linear response in ALA concentration ( > 99%; increases for Flaxseed and L-Flaxseed of 0.095 and 0.140 mg of ALA/g of tissue for each percentage of flaxseed added). This study indicates that a matrix consisting of dolomitic lime hydrate is an effective barrier to ruminal biohydrogenation of PUFA; however, adverse effects on DMI limit the amounts that can be fed.

Protection of polyunsaturated fatty acids against ruminal biohydrogenation: Pilot experiments for three approaches

Three methods for protection of PUFA against biohydrogenation by ruminal microorganisms were evaluated. In method 1 a blend of ground flaxseed, calcium oxide, and molasses was processed through a dry extruder. In method 2, a blend of ground flaxseed, soybean meal, molasses, and baker's yeast was moistened and prewarmed, allowing enzymes from yeast to produce reducing sugars, and the mixture was subsequently processed through a dry extruder like in method 1. In method 3, ground flaxseed was embedded within a matrix of dolomitic lime hydrate (L-Flaxseed) as a protective barrier against biohydrogenation. Dolomitic lime was mixed with ground flaxseed, water was added, the mixture was blended in a high-speed turbulizer, and the resulting material was then dried to form a granular matrix. Methods 1 and 2 were tested in 1 study (study 1), and method 3 was tested in 2 studies (studies 2 and 3). In study 1, 60 crossbred yearling steers (BW = 475 ± 55 kg) were used in a randomized complete block design experiment. Steers were fed for 12 d with a diet consisting of 48.73% steam-flaked corn, 35% wet corn gluten feed, 12% corn silage, and 4.27% vitamins and minerals (Control). For the other 4 treatments, a portion of wet corn gluten feed was replaced with 5% of unprocessed or extruded mixtures as described for methods 1 and 2. Steers were weighed, and jugular blood samples were taken for analysis of long-chain fatty acids (LCFA) on d 0 and 12 of the study. Both methods failed to improve resistance of PUFA against biohydrogenation (P > 0.1). In study 2, in situ fatty acid disappearance was evaluated for ground flaxseed (Flaxseed) or L-Flaxseed using 6 ruminally fistulated Holstein steers. The proportion of α-linolenic acid (ALA) that was resistant to ruminal biohydrogenation was approximately 2-fold greater for L-Flaxseed than for Flaxseed (P < 0.05). In study 3, 45 steers (269 ± 19.5 kg initial BW) were used in a randomized complete block design. Steers were fed diets containing 0% Flaxseed (No Flaxseed), and in treatments 2 and 3, a portion of flaked corn was replaced with Flaxseed or L-Flaxseed. Animals were weighed and blood samples were taken on d 0, 7, and 14 of the study, and LCFA were analyzed. The use of L-Flaxseed in study 3 increased plasma concentrations of ALA to more than 4 times the level observed in cattle fed unprotected flaxseed, suggesting the dolomitic lime hydrate was effective as a protective barrier against biohydrogenation.

The feasibility and educational value of Hear My Voice, a chaplain-led spiritual life review process for patients with brain cancers and progressive neurologic conditions

Research continues to establish the importance of spirituality for many persons with medical illnesses. This paper describes a pilot study titled, "Hear My Voice," designed to provide an opportunity for persons with progressive neurologic illnesses, including brain tumors and other neurodegenerative diseases, to review and discuss their spirituality with a board-certified chaplain, and to prepare a spiritual legacy document (SLD). First, we provide background information that underscores the importance of such a project for this patient population that is particularly vulnerable to cognitive impairment and communication difficulties. Second, we provide detailed methodology, including the semi-structured interview format used, the development of the SLD, and an overview of responses from participants and investigators. We also describe the quantitative and qualitative approaches to analysis taken with the aim of developing scientific validation in support of the Hear My Voice project.

SunSmart: evaluation of a pilot school-based sun protection intervention in Hispanic early adolescents

The incidence of melanoma is rising among Hispanic populations in the United States. The purpose of this study is to evaluate the impact of a pilot sun safety educational intervention conducted from 2006 to 2012 on Hispanic early adolescents in a high ultraviolet environment. Nineteen schools with high Hispanic enrollment were recruited from urban neighborhoods in Los Angeles. The analytic sample was restricted to students identifying as Hispanic or Latino (n = 777). A mixed effects linear model was used to test mean changes from pre- to posttest on students' sun protection knowledge, attitudes and behaviors. Significant improvements were observed across several cognitive outcomes related to sun protection, including knowledge of and attitudes toward sun protection and self-efficacy to wear sunscreen. However, changes in sun protective behaviors were not achieved. Although some improvements were observed, future studies should identify the factors that motivate sun protection in this population and develop tailored prevention strategies, as improving the sun safe behaviors of Hispanic youths may aid in reducing the risk of melanoma in adulthood in this population.

Manipulation of dietary calcium concentration to potentiate changes in tenderness of beef from heifers supplemented with zilpaterol hydrochloride

Dietary Ca concentrations were manipulated during supplementation of zilpaterol hydrochloride (ZH) to evaluate impact on feedlot performance, carcass characteristics, and beef tenderness using 96 heifers (BW 392 kg ± 3.2). We hypothesized that temporary depletion followed by repletion of dietary Ca before harvest would increase intracellular Ca concentrations, thus stimulating postmortem activity of Ca-dependent proteases to effect changes in tenderness. Heifers were stratified by initial BW and randomly assigned, within strata (block), to treatments consisting of a finishing diet in which Ca was added in the form of limestone (+Ca) or removed (-Ca) during ZH supplementation. Cattle were fed a common diet, including limestone, before ZH supplementation, and 28 d before slaughter, ZH was added to the diet with and without supplemental Ca. Calcium content of the diets during ZH supplementation was 0.74% or 0.19% (diet DM) for +Ca and -Ca, respectively. Zilpaterol hydrochloride was fed for 25 d then removed from the diet 3 d before harvest. The final 3 d before harvest, all cattle were fed Ca at 0.74% of diet DM. Heifers were housed in concrete-surfaced pens with 8 animals/pen (6 pens/treatment). At the end of the finishing phase, animals were weighed and transported to an abattoir in Holcomb, KS. Severity of liver abscesses and HCW were collected the day of harvest, and after 48 h of refrigeration, USDA yield and quality grades, KPH, LM area, and 12th-rib subcutaneous fat thickness were determined. Boneless loin sections were also collected for Warner-Bratzler shear force determination. Removal of Ca did not affect Warner-Bratzler shear force values (P = 0.64). In addition, ADG, DMI, final BW, and feed efficiency were unaffected by treatment (P > 0.05). Carcass measurements also were unaffected by the temporary decrease in dietary Ca (P > 0.05). In conclusion, temporary depletion of dietary Ca during ZH supplementation did not alter beef tenderness, live animal performance, or carcass measurements.

Effects of the Programmed Nutrition Beef Program on feedlot performance and carcass characteristics

The objective of this study was to examine the effects of alternative finishing strategies on feedlot performance and carcass characteristics. Beef steers (64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement. Factor 1 consisted of diet, with cattle fed a conventional (CON) diet or a diet consisting of Programmed Nutrition Beef Program (PN) supplements. The PN treatment included Programmed Nutrition Beef Receiver fed from d 1 through 20 of feeding and Programmed Nutrition Beef Finisher fed from d 21 to harvest. Factor 2 evaluated the presence (EGP+) or absence (EGP-) of exogenous growth promotants (ExGP) in the production system. Steers in the EGP+ treatments were initially implanted with Component E-S, reimplanted with Component TE-IS, and fed 400 mg·animal·dof ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175, and strip loins were removed from 2 carcasses selected at random from each pen for transport to Kansas State University. One 1.27-cm-thick steak was removed from the anterior face for proximate and long-chain fatty acid analysis. There were no diet × ExGP interactions ( > 0.10) for feedlot performance except for DMI ( = 0.02). Steers in the PN/EGP+ treatment consumed more feed than all other treatments ( < 0.05). Both diet and ExGP affected DMI ( < 0.05), with PN and EGP+ steers consuming more feed than their contemporaries. Gain:feed and ADG were unaffected ( > 0.10) by diet, but ExGP improved these measures ( < 0.01). There were no diet × ExGP interactions for carcass characteristics except KPH fat and percentages of yield grade 3 and 4 carcasses ( < 0.05). Diet affected total incidence of liver abscesses because PN steers had a greater ( = 0.05) incidence of liver abscesses than steers in the CON treatment. Diet did not affect the other carcass characteristics ( > 0.10). Use of ExGP increased ( < 0.05) HCW, LM area, and 12th-rib fat but did not affect ( > 0.10) marbling score. Using ExGP reduced the percentage carcasses grading Premium Choice ( < 0.05). No diet × ExGP interactions or diet effects were detected for long-chain fatty acid profiles ( > 0.10). Use of ExGP increased ( < 0.05) the ratio of saturated:unsaturated fatty acids. In summary, the alternative feeding strategy presented in this study produced similar feedlot performance and carcass characteristics compared with a conventional feedlot system.

Effects of the Programmed Nutrition Beef Program on meat quality characteristics

The objective of this study was to examine the effects of alternative finishing strategies on beef steak color and cooked meat characteristics. Beef steers (n = 64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement and initial body weight serving as the blocking factor. Factor 1 consisted of dietary treatment with cattle either being fed a conventional feedlot diet (CON) or a diet that included Programmed Nutrition Beef Program supplements. Cattle in the Programmed Nutrition (PN) treatments were fed in two-stages: 1) the basal diet with Programmed Nutrition Beef Receiver from d 1 to 20 and the basal diet with Programmed Nutrition Beef Finisher from d 21 to harvest. Factor 2 consisted of the inclusion (EGP+) or absence (EGP-) of an exogenous growth promoting program. Steers in the EGP+ treatments were implanted initially with Component E-S, reimplanted with Component TE-IS, and fed 400 mg · d(-1) · steer(-1) of ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175 of feeding and 1 strip loin was removed from 2 carcasses selected at random from each pen for transport to Kansas State University. After 14 d of aging, loins were fabricated into 2.54-cm thick steaks for objective and trained sensory panel measurement of cooked meat characteristics and objective color measurements during 7 d retail display. There were no interactions (P > 0.10) between feeding strategy and exogenous growth promotants for all objective measures of color and cooked meat characteristics. Throughout the display period, PN steaks were darker (P = 0.02) than CON steaks, but surface percentages of oxymyoglobin and metmyoglobin and metmyoglobin reducing ability were unaffected by feeding strategy (P > 0.10). Loins and steaks from PN cattle possessed decreased moisture loss during aging and cooking (P < 0.01). Trained sensory panel evaluation of cooked meat revealed a dietary program × growth promotant interaction for myofibrillar tenderness, connective tissue amount, and overall tenderness (P = 0.01). Compared to the CON/EGP- and PN/EGP- treatments, steaks from the CON/EGP+ and PN/EGP+ treatments were evaluated by panelists as being less myofibrillar and overall tender (P < 0.05). The alternative feeding strategies presented in this study can favorably impact water-holding capacity without negatively compromising retail display discoloration.

Transit effects on fecal Escherichia coli O157 prevalence and coliform concentrations in feedlot cattle

Our objectives were to evaluate the effects of transportation and lairage on fecal shedding of Escherichia coli O157 (E. coli O157), total Escherichia coli, and total coliforms in feedlot cattle, and the relationships between E. coli O157 prevalence and total E. coli population. The study was a randomized complete block design with a split-plot including 2 treatments: a nontransported group, which remained in its pen at all times, and a transported group, which was transported for 1 h in a trailer and subsequently unloaded in a different pen. The experiment was repeated on 3 different days (blocking factor) with 20 steers/d (10 steers/treatment, 60 total). Fecal samples were taken pretransport (h 0) and after 4 and 28 h, lairage from freshly voided fecal pats were taken from each animal. One gram of feces was transferred to a PBS tube, serially diluted, and plated onto Petrifilm for enumeration of total coliforms. Another sample (1 g) was added to gram-negative broth containing cefixime, cefsulodin, and vancomycin, and subjected to immunomagnetic separation. Resulting beads were plated onto MacConkey agar with sorbitol, cefixime, and tellurite. Nonsorbitol fermenting colonies were selected and tested for indole production and O157 antigen agglutination. Results were confirmed using an API 20E kit. Prevalence of E. coli O157 was transient across blocks. E. coli O157 prevalence revealed no treatment × sampling time interaction (P = 0.179) or sampling time effect (P = 0.937), but a tendency for a treatment effect (P = 0.092). Numbers of E. coli and other coliforms did not change across blocks. No effect of treatment (P > 0.7) was observed on total E. coli concentrations or total coliforms. However, tendencies for treatment × sampling time interactions were observed on both populations (P < 0.08), as well as a tendency for a sampling time effect on total E. coli (P = 0.087) and an effect on total coliforms (P = 0.004). Prevalence of E. coli O157 was not correlated with the concentration of total E. coli (P = 0.954). Results suggest that shedding of E. coli O157 and coliforms can vary within a period of 29 h. Greater statistical power and pathogen quantification, as well as hide sampling and stress-related measurements, are needed to be able to conclude on the effects of transport stress on E. coli O157 prevalence and the changes undergone in pathogen shedding patterns after transportation.

Effect of castration method on neurohormonal and electroencephalographic stress indicators in Holstein calves of different ages

As public concern for food animal welfare increases, a need to validate objective pain assessment tools exists in order to formulate animal welfare policies and facilitate regulatory approval of compounds to alleviate pain in livestock in the United States. The aims of this study were (1) to compare the physiological response to pain induced by surgical and nonsurgical (band) castration in calves and (2) to elucidate age-related differences in pain response of calves subjected to different castration methods. Seventy-six Holstein bull calves were blocked by age (≤8-wk and ≥6-mo-old) and randomly assigned to 1 of 4 treatment groups: control (n=20), castration by banding (n=18), cut-and-clamp surgical castration (n=20), and cut-and-pull surgical castration (n=18). Measurements included electroencephalogram, heart rate variability, infrared thermography, electrodermal activity, and concentrations of serum cortisol and plasma substance P before, during, and within 20min following castration. Electroencephalogram recordings showed desynchronization for all treatments, consistent with increased arousal; yet the magnitude of desynchronization was greatest for 6-mo-old calves castrated by cut-and-clamp. Additionally, older calves in the cut-and-pull group showed greater desynchronization than younger calves in the same group. Based on the heart rate variability analysis, 6-mo-old calves in the control or cut-and-pull castration groups showed greater sympathetic tone than younger calves in the same treatment groups. Overall, younger calves showed lower electrodermal activity than older calves. Regardless of treatment, concentrations of cortisol and plasma substance P were greater in 6-mo-old calves relative to their younger counterparts, indicating a more robust response to all treatments in older calves. In summary, neurohormonal and electroencephalographic stress responses of calves to castration were age-specific. Castration by cut-and-clamp showed the most pronounced stress response in 6-mo-old calves. These findings provide evidence that support welfare policies recommending castration at an early age and the use of analgesic compounds at the time of surgical castration especially in older calves. However, the potential long-term negative consequences of early untreated pain must be considered and warrant further investigation.

A simple double-focusing electrostatic ion beam deflector

We have developed an electrostatic, double-focusing 90 degrees deflector for fast ion beams consisting of concentric cylindrical plates of differing heights. In contrast to standard cylindrical deflectors, our design allows for focusing of an incoming parallel beam not only in the plane of deflection but also in the orthogonal direction. The optical properties of our design resemble those of a spherical capacitor deflector while it is much easier and more cost effective to manufacture.

Eelgrass meadows in the California Channel Islands and adjacent coast reveal a mosaic of two species, evidence for introgression and variable clonality

BACKGROUND AND AIMS

Seagrasses are important facilitator species in shallow, soft-bottom marine environments worldwide and, in many places, are threatened by coastal development and eutrophication. One narrow-leaved species (Zostera marina) and one wide-leaved species, variously designated as Z. marina, Z. pacifica or Z. asiatica, are found off the California Channel Islands and adjacent California-Mexico coast. The aim of the present study was to confirm species identification genetically and to link patterns of genetic diversity, connectivity and hybridization among and within the populations with historical sea levels (Ice Age) or the contemporary environment.

METHODS

Samples (n = 11-100) were collected from 28 sites off five California Channel Islands and six sites off the adjacent coast of southern California and Baja California, Mexico. DNA polymorphisms of the rDNA-ITS (internal transcribed spacer) cistron (nuclear), the matK intron (chloroplast) and nine microsatellite loci (nuclear) were examined in a population genetic and phylogeographic context.

KEY RESULTS

All wide-leaved individuals were Z. pacifica, whereas narrow-leaved forms were Z. marina. Microsatellite genotypes were consistent with hybridization between the two species in three populations. The present distribution of Z. pacifica follows a glacial age land mass rather than present oceanographic regimes, but no link was observed between the present distribution of Z. marina and past or present environments. Island populations of Z. marina often were clonal and characterized by low genotypic diversity compared with populations along the Baja California coast. The high level of clonal connectivity around Santa Catalina Island indicated the importance of dispersal and subsequent re-establishment of vegetative fragments.

CONCLUSIONS

The pristine environmental conditions of offshore islands do not guarantee maximum genetic diversity. Future restoration and transplantation efforts of seagrasses must recognize cryptic species and consider the degree of both genetic and genotypic variation in candidate donor populations.

Examining the relative importance of social context referents in predicting intention to change substance abuse behavior using the EASE

There is growing consensus across literatures that more than individual motivation and "will to change" influence whether a client will be able to make and sustain recovery-related changes to prevent drug relapse post-treatment. New areas of inquiry in the substance abuse field have proposed conceptual models that promote an integration of both individual and social context factors, which offer the opportunity for important developments in clinical practice. This study examined the influence of social context referents on clients' intention to change substance abusing behaviors. The Ecological Assessment of Substance abuse Experiences (EASE), an instrument that measures the influence of social context referents on addiction and recovery behaviors, was administered to 302 inpatient and outpatient adults in treatment for substance abuse. Results showed that the number of people in his/her social network favorable towards recovery (Beta=.222); the extent to which one personally identifies with being in recovery (Beta=.339); the perceived importance of people in the client's social network encouraging recovery-related behaviors (Beta=.369); weak beliefs that drugs will lead to positive outcomes (Beta=-.220); and strong beliefs that recovery will lead to positive outcomes (Beta=.307) were all associated with intention to change substance abusing behavior.

Differential effects of 4 types of environmental enrichment on aggressive pecking, feather pecking, feather loss, food wastage and productivity in Japanese quail

1. We examined the effects of 4 types of environmental enrichment (foraging opportunities, structural complexity, sensory stimulation/novelty, and social companionship) on aggressive and feather pecking, feather condition, food wastage, body weight, feed conversion, and egg production in adult Japanese quail. Sex differences were examined where possible. 2. GLM analysis was used to evaluate the effects of enrichment and housing, while test-retest reliability and the stability of measures over 18 d were assessed using partial correlation. 3. Foraging enrichment reduced food wastage. 4. Body weight, feed conversion, and egg production were not affected by enrichment. Rates of aggressive and feather pecking were also not significantly affected, but these behaviours were observed very infrequently in this study. 5. Socially-housed birds had poorer feather condition, lower body weight and less efficient feed conversion than singly-housed birds. Social housing did not affect food wastage. 6. There were not sex differences in feather pecking, feather condition, food wastage, or feed conversion. 7. All measures except feather pecking were reliable over 24 h, but only feather condition and body weight were stable over 18 d. The instability f the behavioural measures over time suggest that enrichment effects may vary with age.

A remote and highly conserved enhancer supports amygdala specific expression of the gene encoding the anxiogenic neuropeptide substance-P

The neuropeptide substance P (SP), encoded by the preprotachykinin-A (PPTA) gene, is expressed in the central and medial amygdaloid nucleus, where it plays a critical role in modulating fear and anxiety related behaviour. Determining the regulatory systems that support PPTA expression in the amygdala may provide important insights into the causes of depression and anxiety related disorders and will provide avenues for the development of novel therapies. In order to identify the tissue specific regulatory element responsible for supporting expression of the PPTA gene in the amygdala, we used long-range comparative genomics in combination with transgenic analysis and immunohistochemistry. By comparing human and chicken genomes, it was possible to detect and characterise a highly conserved long-range enhancer that supported tissue specific expression in SP expressing cells of the medial and central amygdaloid bodies (ECR1; 158.5 kb 5' of human PPTA ORF). Further bioinformatic analysis using the TRANSFAC database indicated that the ECR1 element contained multiple and highly conserved consensus binding sequences of transcription factors (TFs) such as MEIS1. The results of immunohistochemical analysis of transgenic lines were consistent with the hypothesis that the MEIS1 TF interacts with and maintains ECR1 activity in the central amygdala in vivo. The discovery of ECR1 and the in vivo functional relationship with MEIS1 inferred by our studies suggests a mechanism to the regulatory systems that control PPTA expression in the amygdala. Uncovering these mechanisms may play an important role in the future development of tissue specific therapies for the treatment of anxiety and depression.

Total hip arthroplasty with cement and without acetabular bone graft for severe hip dysplasia. A concise follow-up, at a minimum of twenty years, of a previous report

We previously evaluated a cohort of fifty-three patients with severe hip dysplasia (Crowe Type-II, III, or IV subluxation) who underwent a total of sixty-six Charnley total hip arthroplasties. The acetabular component was placed at the anatomic hip center, the superolateral defect was filled with cement, and no bone-grafting was used to supplement the acetabular wall. All but one patient, who was lost to follow-up, were followed until death or for a minimum of twenty years. Radiographic and functional follow-up data were collected prospectively. This retrospective review included twenty-four patients (thirty-four hips) who were alive at a minimum of twenty years following the surgery. Fourteen (22%) of the sixty-five hips underwent revision of a component, with eleven of the revisions performed because of aseptic loosening. Eight of those eleven hips underwent revision because of acetabular loosening alone; two, because of femoral loosening alone; and one, because of loosening of both components. The combined prevalence of revision because of aseptic loosening of the acetabular component and radiographic evidence of failure of the acetabular component was 28% (eighteen hips). With the numbers available, the need for acetabular revision was not associated with the percentage of cement coverage (p = 0.362) or the Crowe classification (p = 0.159). At a minimum of twenty years postoperatively, the survivorship of the acetabular component was 86% +/- 8% with revision because of aseptic loosening as the end point and 82% +/- 10% with revision because of aseptic loosening or radiographic evidence of loosening as the end point. The results that we evaluated at a minimum of twenty years after use of this technique can be compared with the results of other techniques in studies with similar long-term follow-up periods.

Hepatic CYP1A levels and EROD activity in English sole: biomonitoring of marine contaminants in Vancouver Harbour

To assess chemical contaminant stress in the marine environment, ethoxyresorufin-O-deethylase (EROD) activity and cytochrome P450 1A (CYP1A) expression were measured in 88 English Sole (Pleuronectes vetulus) collected during May and June 1999 from four sites in Vancouver Harbour and at an expected reference site outside the harbour. Hepatic microsomes were prepared from the fish and analyzed for total CYP content, EROD activity, and CYP1A protein levels. Hepatic EROD activity and CYP1A protein levels were elevated in fish from two sites in the inner harbour. A comparison with sediment chemistry data showed that fish with increased EROD activity and CYP1A levels came from sites containing relatively high levels of polycyclic aromatic hydrocarbons and polychlorinated biphenyls. Unexpectedly high levels of EROD activity and CYP1A protein were also found in fish from a reference site near Gibsons, in Howe Sound. The elevated EROD activity and CYP1A expression in fish from this site cannot be explained by the chemical analysis data collected.

Characterisation of a beta-tubulin gene from the monogenean parasite, Gyrodactylus salaris Malmberg, 1957

The cDNA and two partial genomic sequences of beta-tubulin genes have been isolated from the monogenean parasite Gyrodactylus salaris. The cDNA sequence is not represented by either of the genomic sequences, implying that at least three isotypes of the gene exist in G. salaris. The sequences show regions of high homology with other helminth beta-tubulin genes. This represents the first isolation of a beta-tubulin gene from a monogenean and contributes to the overall characterisation of these genes within the helminths. This is an important area, as anthelmintic resistance is increasing against benzimidazole drugs that target the beta-tubulin gene. Benzimidazole drugs have been tested successfully against Gyrodactylus parasites, but their use is not widespread. Should it increase, analysis of the beta-tubulin gene may provide a tool for monitoring resistance development and improving management practises. Use of the beta-tubulin gene in the identification of Gyrodactylus species may prove complex due to the presence of different isotypes.

Experience with laparoscopic adrenalectomy in pediatric patients

BACKGROUND

Laparoscopic adrenalectomy (LA) is now being recognized as the standard in the management of benign adrenal pathology in adult patients. Few reports have described the use of this technique in pediatric patients. This study combines experience from 2 institutions with lateral transperitoneal LA in children to analyze our results and the clinical and biochemical response to laparoscopic adrenalectomy in patients with hormonally active adrenal tumors.

METHODS

A bi-institutional retrospective review of all patients undergoing LA between January 1997 and January 2001 was performed. Clinical and biochemical data were obtained during routine follow-up.

RESULTS

Seventeen laparoscopic adrenalectomies were performed during this period. The average operating time was 120 minutes, mean estimated blood loss was 25 mL, the mean size of the adrenal lesion was 4.8 cm, and the mean length of hospitalization was 35 hours. Resolution of clinical and biochemical parameters of adrenal hyperfunction was accomplished in all patients with adrenocortical hyperplasia and pheochromocytoma in postoperative follow-up.

CONCLUSIONS

Laparoscopic adrenalectomy can be performed safely and effectively with a short hospital stay, minimal blood loss, and excellent functional outcome in this age group. The authors believe laparoscopic adrenalectomy is an excellent approach for the management of benign pediatric adrenal pathology.

Minimally invasive bar repair for 'redo' correction of pectus excavatum

BACKGROUND/PURPOSE

A small percentage of patients who have undergone traditional, "Ravitch-type" pectus excavatum repair present with unsatisfactory results and require a second procedure for correction. Reoperative open surgery for pectus excavatum has been associated with extensive dissection and substantial blood loss. The minimally invasive (MIS) bar repair for the correction of pectus excavatum has been gaining acceptance. This study evaluates the authors results with patients who have undergone the MIS bar repair for redo correction of their pectus excavatum.

METHODS

A retrospective chart review of all patients undergoing MIS bar repair between December 1997 and August 2001 was performed. Information about demographics, deformity, operative course, complications, and early outcome was recorded.

RESULTS

Ninety-two patients underwent MIS repair during this period. Ten patients had redo MIS bar repair for unsatisfactory prior open correction. Operating time was 52 minutes for standard patients and 70 minutes for the redo patients (P <.001). Blood loss and postoperative hospitalization were similar between groups.

CONCLUSION

The minimally invasive pectus repair can be performed safely with minimal blood loss and short operating time in patients who have undergone prior unsatisfactory open repair of pectus excavatum and can be an alternative approach to reoperative open repair in these patients.

Kruppel-like factor 4 regulates laminin alpha 3A expression in mammary epithelial cells

Laminin-5, the major extracellular matrix protein produced by mammary epithelial cells, is composed of three chains (designated alpha3A, beta3, and gamma2), each encoded by a separate gene. Laminin-5 is markedly down-regulated in breast cancer cells. Little is known about the regulation of laminin gene transcription in normal breast cells, nor about the mechanism underlying the down-regulation seen in cancer. In the present study, we cloned the promoter of the gene for the human laminin alpha3A chain (LAMA3A) and investigated its regulation in functionally normal MCF10A breast epithelial cells and several breast cancer cell lines. Using site-directed mutagenesis of promoter-reporter constructs in transient transfection assays in MCF10A cells, we find that two binding sites for Kruppel-like factor 4 (KLF4/GKLF/EZF) are required for expression driven by the LAMA3A promoter. Electrophoretic mobility shift assays reveal absence of KLF4 binding activity in extracts from T47D, MDA-MB 231, ZR75-1, MDA-MB 436, and MCF7 breast cancer cells. Transient transfection of a plasmid expressing KLF4 activates transcription from the LAMA3A promoter in breast cancer cells. A reporter vector containing duplicate KLF4-binding sites in its promoter is expressed at high levels in MCF10A cells but at negligible levels in breast cancer cells. Thus, KLF4 is required for LAMA3A expression and absence of laminin alpha3A in breast cancer cells appears, at least in part, attributable to the lack of KLF4 activity.

Management of intestinal atresia in patients with gastroschisis

BACKGROUND/PURPOSE

Intestinal atresia occurs in approximately 10% to 20% of children with gastroschisis and may be missed at the initial closure if a thick peel obscures the bowel. Some investigators have identified intestinal atresia as a significant contributor to morbidity and mortality. The authors reviewed their experience with gastroschisis and intestinal atresia in an attempt to answer the following questions. What is the incidence of this association? How often is the intestinal atresia unrecognized as a result of the peel? What is the optimal management for infants with atresia and gastroschisis, and does the atresia affect morbidity or mortality?

METHODS

The hospital charts and medical records of all patients with gastroschisis treated at our institution from 1969 to present were reviewed thoroughly. Parameters analyzed included gestational age (GA), birth weight (BW), antenatal diagnosis, mode of delivery, type of closure, era of repair, presence of other major anomalies, and development of necrotizing enterocolitis. Morbidity and mortality rates were examined. Characteristics of patients with and without atresia were compared. Chi-squared was used for crosstabular analysis. Sample parameters were compared with Student's t test. P values of less than.05 were considered significant.

RESULTS

A total of 199 babies had gastroschisis and 25 (12.6%) had intestinal atresia. Intestinal atresia was initially unrecognized in 3 patients. Most patients (80%) underwent primary closure of the abdominal wall. Initial stoma formation and delayed anastomosis was performed in 12 (48%) patients, none of whom required prosthetic material for abdominal wall closure. Initial stomas were avoided in 5 patients who required SILASTIC (Dow Corning, Midland, MI) silos. Skin closure alone was used in 2 babies. The level of the atresia was most commonly jejunoileal (20 of 25, 80%). Mean hospital stay was increased in babies with intestinal atresia, 36.2 versus 63.1 days (P <.001).

CONCLUSIONS

Although patients with intestinal atresia did have feeding delays, an increased incidence of adhesive intestinal obstruction, and prolonged hospitalization, neither chi(2) nor logistic regression analysis showed any correlation with mortality. Intestinal repair at the first operation is sometimes possible and depends on the severity of the peel. Delayed repair of the atresia after a period of bowel decompression and parenteral nutrition is preferred, but in certain situations (colonic atresia, necrotic intestine, complicated atresia) may not be possible. The combination of stomas and prosthetic material can be avoided in almost all patients. A management algorithm for patients with atresia and gastroschisis is discussed.

Minimally invasive repair of pectus excavatum: a single institution's experience

BACKGROUND

The Nuss repair of pectus excavatum is a relatively new, minimally invasive surgical (MIS) alternative to the traditional open "Ravitch-type" operation. We have one of the larger single-center experiences to date, and we conducted this clinical study to evaluate our early experience, emphasizing initial outcome and technical modifications designed to minimize complications.

METHODS

A retrospective chart review was performed on 112 patients who underwent 116 pectus excavatum repairs between January 1995 and January 2001. The Nuss procedure was performed in 80 patients, and open repair was performed in 32 patients. Information about demographics, deformity, operative course, complications, and early outcome was recorded.

RESULTS

Operative duration was 143 minutes for the open group and 53 minutes for the Nuss MIS group (P <.001). Blood loss was 6 mL/kg for the open group and 0.5 mL/kg for the MIS group (P <.001). Postoperative hospitalization was 3.2 days for the open group versus 3.7 days for the MIS group (P<.05).

CONCLUSIONS

The MIS pectus repair can be performed safely with minimal blood loss and reduced operative time. Short-term analysis of the quality of repair, including absence of preoperative symptoms, patient satisfaction, and cosmetic appearance are encouraging.

1% lidocaine injection, EMLA cream, or "numby stuff" for topical analgesia associated with peripheral intravenous cannulation

The purpose of this study was to assess patient's perception of pain associated with peripheral intravenous (i.v.) cannulation, using 3 methods of applying local anesthetics. A prospective, randomized, quasi-experimental study was conducted, using a convenience sample of men and women, ASA physical status I, II, or III, undergoing outpatient or same-day surgery. Group 1 received a subcutaneous injection of 1% lidocaine, group 2 received topical EMLA cream for 45 to 60 minutes, and group 3 received treatment with "Numby Stuff" for 40 mA minutes. After the intended analgesic treatment was complete, the patient was asked to rate the pain experienced during the skin-numbing process. An i.v. was then started using an 18-gauge i.v. catheter, and the patient again was asked to rate the amount of pain experienced with the catheter insertion. A visual analog scale was used as the tool of measurement for pain. Results of the study showed that group 1 experienced a higher treatment pain score than either group 2 or group 3, while group 2 experienced a higher pain score when the i.v. was started than either group 1 or group 3. Of the 3 methods tested, results seem to indicate that the Numby Stuff system using iontophoresis is the superior method for decreasing the pain associated with peripheral i.v. cannulation, and application of the analgesic method does not cause significant pain.

Relationship of MTT reduction to stimulants of muscle metabolism

MTT, a positively charged tetrazolium salt, is widely used as an indicator of cell viability and metabolism and has potential for histochemical identification of tissue regions of hypermetabolism. In the present study, MTT was infused in the constant-flow perfused rat hindlimb to assess the effect of various agents and particularly vasoconstrictors that increase muscle metabolism. Reduction of MTT to the insoluble formazan in muscles assessed at the end of experiments was linear over a 30 min period and production rates were greater in red fibre types than white fibre types. The vasoconstrictors, norepinephrine (100 nM) and angiotensin (10 nM) decreased MTT formazan production in all muscles but increased hindlimb oxygen uptake and lactate efflux. Veratridine, a Na(+) channel opener that increases hindlimb oxygen uptake and lactate efflux without increases in perfusion pressure, also decreased MTT formazan production. Membrane stabilizing doses (100 microM) of (+/-)-propranolol reversed the inhibitory effects of angiotensin and veratridine on MTT formazan production. Muscle contractions elicited by stimulation of the sciatic nerve, reversed the norepinephrine-mediated inhibitory effects on MTT formazan production, even though oxygen consumption and lactate efflux were further stimulated. Stimulation of hindlimb muscle oxygen uptake by pentachlorophenol, a mitochondrial uncoupler, was not associated with alterations in MTT formazan production. It is concluded that apart from muscle contractions MTT formazan production does not increase with increased muscle metabolism. Since the vasoconstrictors angiotensin and norepinephrine as well as veratridine activate Na(+) channels and the Na(+)/K(+) pump, energy required for Na(+) pumping may be required for MTT reduction. It is unlikely that vasoconstrictors that stimulate oxygen uptake do so by uncoupling respiration.

Anterior submucous laryngeal cleft

Upper airway obstruction in the newborn is frequently due to congenital laryngeal anomalies. One of these, the posterior laryngeal cleft, is often associated with subglottic stenosis and respiratory difficulty. This discussion of the anterior laryngeal cleft reports findings in an infant who required intubation immediately after birth and survived only 3 days. The anterior cricoid cleft was associated with severe congenital anomalies including congenital tracheal stenosis.

Benzodiazepines protect hippocampal neurons from degeneration after transient cerebral ischemia: an ultrastructural study

The ability of full and partial benzodiazepine receptor agonists to prevent DNA fragmentation and neuronal death after transient cerebral ischemia was investigated in the Mongolian gerbil. Diazepam (10mg/kg, i.p.) or the partial agonist imidazenil (3mg/kg, i.p.) was administered 30 and 90min after transient forebrain ischemia produced by occlusion of the carotid arteries for 5min. Treatment with diazepam completely protected CA1b hippocampal pyramidal neurons in 94% of the animals and partially protected pyramidal neurons in 6% of the animals, as assessed with a standard Nissl stain three and four days after ischemia. DNA fragmentation was examined by the terminal dUTP nick-end labeling (TUNEL) reaction. Prior to cell death, there were no TUNEL-positive neurons in area CA1b. By three days after ischemia, when neuronal degeneration was nearly complete, 14 out of 16 gerbils exhibited a positive TUNEL reaction throughout area CA1b stratum pyramidale. In 13 out of 14 gerbils treated with diazepam, no TUNEL-positive neurons were observed in this region. Imidazenil was less effective than diazepam with respect to both neuroprotection and prevention of DNA fragmentation. Three days after ischemia, six out of eight gerbils treated with imidazenil showed partial to complete neuroprotection. Imidazenil completely prevented DNA fragmentation in only one of the animals; varying degrees of TUNEL reaction persisted in the remainder. To determine whether the neurons protected by diazepam had a normal ultrastructure, gerbils were killed two to 30 days after ischemia and the hippocampal neurons in area CA1b were examined by electron microscopy. Within the first 48h after ischemia, early cytoplasmic changes of varying degrees (e.g., vacuolation, rough endoplasmic reticulum stacking, swollen mitochondria) and electron-dense dendrites were observed in gerbils not treated with diazepam. Degeneration was nearly complete by three days after ischemia. In contrast, pyramidal neuron ultrastructure appeared normal in gerbils that exhibited complete area CA1b neuroprotection (defined at the light microscope level) by diazepam when studied two, seven or 30 days after ischemia. In gerbils with partial protection of area CA1b, most of the remaining neurons exhibited varying degrees of necrosis when studied 30 days after ischemia. No apoptotic bodies were observed. We conclude that: (i) diazepam can fully protect CA1 pyramidal cells from the toxic effects of transient cerebral ischemia; (ii) when diazepam affords only partial neuroprotection, the residual CA1 pyramidal cells exhibit ultrastructural abnormalities consistent with necrotic damage; and (iii) diazepam is a more efficacious neuroprotectant than the partial benzodiazepine receptor agonist, imidazenil.

Evaluation of health status and quality of life after bariatric surgery: comparison of standard Roux-en-Y gastric bypass, vertical banded gastroplasty and laparoscopic adjustable silicone gastric banding

BACKGROUND

This study is a trial to compare the effects and outcomes of three different bariatric procedures performed in two centers. Standard Roux-en-Y gastric bypass was performed by Dr. Norman Samuels in Fort Lauderdale (Florida); vertical banded gastroplasty and laparoscopic adjustable silicone gastric banding were done in Hallein (Salzburg) by Dr. Emanuel Hell and Dr. Karl Miller.

METHODS

In a prospective comparative study 30 matched patients from each group were followed to assess post-operative improvement in health status and quality of life, to compare the three different techniques. The Bariatric Analysis and Reporting Outcome System (BAROS) as described by Oria and Moorehead has been used for evaluation.

RESULTS

The observation time was at least 3 years (3 to 8 years) in each individual case. A significant increase in quality of life and health status in 75% of the surgically-treated patients was observed when compared with a non-operated control group of morbidly obese patients.

CONCLUSIONS

By utilizing BAROS it has been found possible to compare the results of different procedures done by different surgeons with different techniques, utilizing patients from different cultures and with different languages. The results of this comparative study favor the standard gastric bypass for the treatment of morbid obesity. This operation is superior to purely gastric restrictive procedures in weight loss and improvement of quality of life.

Inhibition of laminin-5 production in breast epithelial cells by overexpression of p300

The transcriptional coactivator p300 is essential for normal embryonic development and cellular differentiation. We have been studying the role of p300 in the transcription of a variety of genes, and we became interested in the role of this coactivator in the transcription of genes important in breast epithelial cell biology. From MCF-10A cells (spontaneously immortalized, nontransformed human breast epithelial cells), we developed cell lines that stably overexpress p300. These p300-overexpressing cells displayed reduced adhesion to culture dishes and were found to secrete an extracellular matrix deficient in laminin-5. Laminin-5 is the major extracellular matrix component produced by breast epithelium. Immunofluorescence studies, as well as experiments using normal matrix, confirmed that the decreased adhesion of p300-overexpressing cells is due to laminin-5-deficient extracellular matrix and not due to loss of laminin-5 receptors. Northern blots revealed markedly decreased levels of expression of two of the genes (designated LAMA3 and LAMC2) encoding the alpha3 and gamma2 chains of the laminin-5 heterotrimer in the cells that overexpress p300, whereas LAMB3 mRNA, encoding the third or beta3 chain of laminin-5, was not markedly reduced. Transient transfection experiments with a vector containing a murine LAMA3 promoter demonstrate that overexpressing p300 down-regulates the LAMA3 promoter. In summary, overexpression of p300 leads to down-regulation of laminin-5 production in breast epithelial cells, resulting in decreased adhesion.

Pharmacological and behavioral characterization of cocaine-kindled seizures in mice

RATIONALE

Convulsions associated with cocaine toxicity are a serious aspect of cocaine-related emergency room incidents. Seizures can result from a single high dose of cocaine, and evidence is accumulating that correlates repetitive administration of sub-convulsive doses of cocaine with a decreased seizure threshold, a phenomenon known as pharmacological kindling. A murine model of cocaine kindling has not been characterized.

OBJECTIVES

To determine the necessary and sufficient conditions for generating increased sensitivity to the convulsive and lethal effects of cocaine and to characterize some of the basic pharmacological and behavioral consequences of this phenomenon in mice.

METHODS

Male, Swiss-Webster mice were given repeated injections of cocaine.

RESULTS

Daily administration of 60 mg/kg cocaine produced robust kindling; significant leftward shifts in the dose-effect curves for seizures were observed in cocaine-kindled mice. Cocaine kindling was enduring as these left shifts persisted for at least 20 days, indicating possible permanent synaptic changes. Induction of convulsions per se, utilizing 75 mg/kg cocaine, was not sufficient to engender kindling with a non-optimal dose (40 mg/kg). However, administration of a non-kindling dose of cocaine (40 mg/kg) for as few as four occasions produced increased seizure sensitivity to a 60-mg/kg cocaine challenge. The lethal potencies of cocaine and methamphetamine were significantly increased in cocaine-kindled mice. The baseline locomotor activity of kindled mice was not different from that of non-kindled mice. However, challenge doses of cocaine revealed significant differences in the vertically directed activity of kindled versus non-kindled mice.

CONCLUSIONS

Overall, this study provides a description of important parameters for a model of cocaine kindling in mice that may be useful for the elucidation of mechanisms responsible for the long-term changes in sensitivity to cocaine and the discovery of novel pharmacological treatments.

Molecular pharmacology of Agouti protein in vitro and in vivo

Agouti protein and Agouti-related protein (Agrp) are paracrine signaling molecules that act by antagonizing the effects of melanocortins, and several alternatives have been proposed to explain their mechanisms of action. Genetic crosses in a sensitized background uncover a phenotypic difference between overexpression of Agouti and loss of Mc1r function, demonstrate that a functional Mc1r is required for the pigmentary effects of Agouti, and suggest that Agouti protein can act as an agonist of the Mc1r in a way that differs from alpha-MSH stimulation. In vitro, Agouti protein inhibits melanocortin action by two mechanisms: competitive antagonism that depends on the carboxyterminus of the protein, and downregulation of melanocortin receptor signaling that depends on the aminoterminus. Our findings provide evidence of a novel signaling mechanism whereby alpha-MSH and Agouti protein function as independent ligands that inhibit each other's binding and transduce opposite signals through a single receptor.

The mouse mahogany locus encodes a transmembrane form of human attractin

Agouti protein and agouti-related protein are homologous paracrine signalling molecules that normally regulate hair colour and body weight, respectively, by antagonizing signalling through melanocortin receptors. Expression of Agouti is normally limited to the skin, but rare alleles from which Agouti is expressed ubiquitously, such as lethal yellow, have pleiotropic effects that include a yellow coat, obesity, increased linear growth, and immune defects. The mahogany (mg) mutation suppresses the effects of lethal yellow on pigmentation and body weight, and results of our previous genetic studies place mg downstream of transcription of Agouti but upstream of melanocortin receptors. Here we use positional cloning to identify a candidate gene for mahogany, Mgca. The predicted protein encoded by Mgca is a 1,428-amino-acid, single-transmembrane-domain protein that is expressed in many tissues, including pigment cells and the hypothalamus. The extracellular domain of the Mgca protein is the orthologue of human attractin, a circulating molecule produced by activated T cells that has been implicated in immune-cell interactions. These observations provide new insight into the regulation of energy metabolism and indicate a molecular basis for crosstalk between melanocortin-receptor signalling and immune function.

The performance of subcutaneously injected Fertinex when used as the sole gonadotropin for in vitro fertilization stimulation

OBJECTIVE

To assess the performance of Fertinex (urofollitropin; Serono Laboratories, Norwell, MA) in stimulating the development of multiple follicles and initiating subsequent pregnancy in patients undergoing controlled ovarian hyperstimulation (COH) for IVF.

DESIGN

Prospective observational study.

SETTING

Private assisted reproductive technology (ART) center.

PATIENT(S)

Ninety-three women who underwent an IVF cycle of COH in which Fertinex was used as the sole gonadotropin.

INTERVENTION(S)

The COH protocol included Fertinex with leuprolide acetate down-regulation in the late luteal phase or the early follicular phase. Embryo transfer was performed after 3 days of culture.

MAIN OUTCOME MEASURE(S)

Stimulation parameters, embryologic data, and pregnancy rates (PRs).

RESULT(S)

Ninety-three patients underwent 97 cycles of COH, with a cancellation rate of 13.4%. The clinical PR was 42% per initiation, 49% per retrieval, and 51% per transfer. Shorter stimulation periods, lower estradiol levels either per follicle punctured or per oocyte retrieved, and slower embryo development were observed. Patients responded to Fertinex in three distinct stimulation patterns: escalating response with a peak estradiol level of < or =3,000 pg/mL, escalating response with a peak estradiol level of >3,000 pg/mL, or escalating response characterized by a drop in the estradiol level or a plateau before hCG administration. All three responses had similar PRs.

CONCLUSION(S)

Fertinex can be used successfully as the sole gonadotropin for COH in ART without compromising high PRs. Traditional estradiol response curves or cancellation criteria may not apply when Fertinex is used as the sole gonadotropin for COH in ART.

Compatibility and stability of fentanyl admixtures in polypropylene syringes

OBJECTIVE

To determine the physicochemical stability of fentanyl in combination with midazolam and either hyoscine butylbromide or metoclopramide, and stored in 30 ml polypropylene syringes.

METHODS

Solutions containing approximately 40 microg/ ml of fentanyl in combination with midazolam (approximately 600 microg/ml) and either metoclopramide (approximately 700 microg/l) or hyoscine (approximately 850 microg/ml) were prepared from commercial ampoules of the drugs. The solutions were stored, in triplicate, in the dark at 32 degrees C (to simulate usage conditions) for 10 days, and the concentration of each constituent drug was periodically determined using a stability-indicating high-performance liquid chromatography assay.

RESULTS

The combinations were relatively stable, with all drugs maintaining over 90% of their initial chemical potency for at least 1 week. There were no evident changes in either the physical appearance or pH values of the solutions over the course of the study.

CONCLUSIONS

On the basis of physicochemical stability, polypropylene syringes containing fentanyl with midazolam and either hyoscine butylbromide or metoclopramide can be safely prepared and stored at or below 32 degrees C for periods of up to 1 week prior to use by palliative care patients receiving the drugs via a portable subcutaneous infusion device.

Serotonin inhibition of 1-methylxanthine metabolism parallels its vasoconstrictor activity and inhibition of oxygen uptake in perfused rat hindlimb

The effect of serotonin (5-HT) on the metabolism of infused 1-methylxanthine (1-MX), a putative substrate of capillary endothelial xanthine oxidase (XO), and on the distribution of infused fluorescent microspheres (15 microns) by the artificially constant-flow perfused rat hindlimb preparation was investigated. 1-MX (5-100 microM) caused a slight inhibition of oxygen uptake (Vo2) but was not vasoactive, either alone or with 5-HT. 1-MX was converted to 1-methylurate (1-MU) and this conversion was inhibited by allopurinol and xanthine. 5-HT (0.35 microM), which caused vasoconstriction and decreased Vo2, also inhibited the conversion of 1-MX, indicated by a lowered venous perfusate steady-state 1-MU:1-MX ratio from 1.14 +/- 0.02 to 0.71 +/- 0.02 (P < 0.001), which is equivalent to the rate of conversion decreasing from 0.83 +/- 0.03 to 0.63 +/- 0.05 nmol min-1 g-1. This change closely followed the time course for changes in Vo2 and perfusion pressure and all three changes reversed in parallel when 5-HT was removed. Recoveries of 1-MU plus 1-MX at all times were high (100 +/- 5%). 5-HT did not act to inhibit XO. When compared with vehicle alone, 5-HT had either no effect (plantairs, gastrocnemius white, tibialis, extensor digitorum longus, vastus and thigh), or increased microsphere content (soleus and gastrocnemius red, P < 0.05) of muscles with only bone showing a significant decrease (P < 0.05). Since 5-HT did not inhibit XO or alter the net flow to individual muscles in this constant-flow model, the inhibition of conversion of 1-MX to 1-MU is concluded to be the result of a 5-HT-mediated decrease in the access of 1-MX to capillary XO within individual muscles. Possibilities include the redirection of flow to capillaries either in muscle or in connective tissue closely associated with muscle, where resistance is low and effective surface area is less. 1-MX has potential as a marker for muscle nutritive flow.

Clinical evaluation of the HeartPak. A new pneumatic portable driver for use with the HeartMate Implantable Pneumatic Left Ventricular Assist System

The HeartPak Portable Pneumatic Driver was designed for use with the HeartMate Implantable Pneumatic Left Ventricular Assist Device (IP-LVAS) (Thermo Cardiosystems, Inc., Woburn, MA). The HeartPak measures 48 x 23 x 15 cm, weighs 9.3 kg with batteries, and can be carried by a handle, by a shoulder strap, or on a trolley. Four 12 V batteries provide power for as long as 8 hr. To test the HeartPak in the hospital environment, seven men were studied who were bridge-to-transplant patients (mean age, 59.8 +/- 8.87 years) undergoing HeartMate IP-LVAS therapy. They were supported by the HeartPak for 429 days with a cycle count of 57,826,560. To normalize the mean pump flow rate, we used the body surface area to obtain a pump flow index in each case. The mean flow rate was 2.65 +/- 0.57 L/min/m2 for the HeartPak vs. 2.64 +/- 0.45 L/min/m2 for the HeartMate 1000, the conventional driver previously used in these patients. The only potentially serious problem with the HeartPak was console failure in one case. The patient took appropriate backup measures, and the HeartPak was replaced. In no case did the device cause any adverse effects or interruption of LVAS support. Compared with HeartMate 1000, the HeartPak was more convenient, easier to operate, and allowed better patient mobility.

Genetic studies of the mouse mutations mahogany and mahoganoid

The mouse mutations mahogany (mg) and mahoganoid (md) are negative modifiers of the Agouti coat color gene, which encodes a paracrine signaling molecule that induces a swithc in melanin synthesis from eumelanin to pheomelanin. Animals mutant for md or mg synthesize very little or no pheomelanin depending on Agouti gene background. The Agouti protein is normally expressed in the skin and acts as an antagonist of the melanocyte receptor for alpha-MSH (Mc1r); however, ectopic expression of Agouti causes obesity, possibly by antagonizing melanocortin receptors expressed in the brain. To investigate where md and mg lie in a genetic pathway with regard to Agouti and Mc1r signaling, we determined the effects of these mutations in animals that carried either a loss-of-function Mc1r mutation (recessive yellow, Mc1re) or a gain-of-function Agouti mutation (lethal yellow, Ay). We found that the Mc1re mutation suppressed the effects of md and mg, but that md and mg suppressed the effects of Ay on both coat color and obesity. Plasma levels of alpha-MSH and of ACTH were unaffected by md or mg. These results suggest that md and mg interfere directly with Agouti signaling, possibly at the level of protein production or receptor regulation.