Temporary Removal Research Articles

Use of the laryngeal mask airway in a patient with a difficult airway during supra-stoma granuloma removal

To the Editor: Supra-stoma granuloma can be treated effectively via rigid bronchoscopy.1 General anesthesia is required and ventilation can be controlled through the bronchoscope’s side port or a cuffed tracheostomy tube. However, rigid bronchoscopy may be impossible in patients with a difficult airway. We describe a modified surgical approach of supra-stoma granuloma removal and our anesthetic management in a patient with a difficult airway. A 60-yr-old patient had speech limitation due to a tracheostomy tube and supra-stoma granuloma. She had a difficult airway, which made two attempts at rigid bronchoscopy abort. To improve her speech, the surgeons planed to remove the granuloma directly through the tracheostomy stoma, followed by insertion of a Montgomery T-tube. However, the tracheostomy tube would be removed and no secure airway existed during the procedure. Under total iv anesthesia, a cuffed tracheostomy tube was first used for ventilation. We inserted a laryngeal mask airway (LMA) as a conduit to introduce the flexible fibrescope, and found the trachea was partially occluded. We then tried to ventilate through the LMA after temporary removal of the tracheostomy tube and occlusion of the stoma, and found that ventilation was possible. The peak inspiratory pressure was 35 cm H2O for a tidal volume of 400 mL with minimal air leakage. We then decided to hyperventilate the lungs via the LMA (HV-LMA) between surgical manipulations, during periods when the airway could not be accessed. After a period of hyperventilation, the surgeons removed the tracheostomy tube and proceeded with removal of the granuloma through the stoma. When the oxygen saturation (SpO2) declined below 95%, HV-LMA was performed. Surgery continued after the SpO2 reached 99%. The procedure lasted about ten minutes and the SpO2 was kept above 92%. In this patient, the success of HV-LMA depended both on partial obstruction by the granuloma, and an excellent seal with the LMA. In a previous report, leak pressure was found to be 29 cm H2O (SD 6) for the ProSeal LMA and 19 cm H2O (SD 4) for the classic LMA.2 The patient’s narrow oropharyngeal/hypopharyngeal space might explain the excellent seal observed. To prevent stomach inflation and aspiration, we used a stethoscope over the epigastrum to monitor stomach inflation. Fortunately, granuloma removal was brief and only two periods of HV-LMA were required, attenuating the risk of gastric inflation. Nevertheless, we were well prepared and would have reinserted a cuffed tracheostomy tube for conditions like uncontrolled airway bleeding, inability to ventilate, or unstable vital signs.

Review: A Classical sacred miscellany

Antonio Salieri lived a long life, from 1750 to 1825. Although primarily associated with opera in Vienna, from the mid-179os onwards he devoted most of his compositional energies to liturgical music, completing about loo works. Rather surprisingly, he composed only four Masses with orchestral accompaniment, all intended for the Hofkapelle, where he was Kapellmeister. The Mass in D minor was completed in July 1805, during the French occupation of Austria and the temporary removal of the court from Vienna. It may be tempting to link the choice of key, D minor, with the unease with which it is associated in Haydn's 'Nelson' Mass or with the melancholy and power of Mozart's Requiem, but Salieri's Mass spends most of its time in the tonic major. As Jane Schatkin Hettrick points out, the title 'Mass in D minor' is a humdrum consequence of contemporary cataloguing practice, and not an indication of a governing mood. This observation is typical of the authoritative editorial hand that is evident throughout the volume. The Mass is carefully placed in its historical context, and performers, as well as future editors of other works in the Hofkapelle repertory, will benefit from Hettrick's experienced observations on musical shorthand, copying practices and performance practice (including size of vocal forces and the make-up of the organ). Unusually, much of the continuo organ part was fully written out by Salieri, providing a useful model for other liturgical music of the period; generally it is much sparser than one typically hears in modern performances of this repertory, with a good deal of two-part writing. Hettrick is also sensitive to Salieri's personality as a composer of liturgical music. As she observes, he was one of those who regarded Haydn's sacred compositions as overdone; indeed, the Mass has a caution that one would not have expected from such an experienced composer of opera. Vocal lines hardly ever burgeon, and the open theatricality of Haydn's late Masses-evident too in contemporary Masses by Michael Haydn and Hummel-is avoided. Hettrick suggests that this understated style reflected the preferences of the emperor, Franz II, and her commentary on the individual movements sensitively relates the music to a range of contemporary comments on judicious style in church music. Leopold Ferdinand Schwerdt was born in Lower Austria in the 1770s, but from 18o6 spent most of his working life in Laibach (Ljubljana), a distant corner of the Austrian territories, but one whose musical practices reflected those of the broader Viennese tradition.

14 SYNCHRONIZATION OF OVULATION IN ANESTROUS NELORE COWS TREATED WITH HORMONAL PROTOCOL WITHOUT PROGESTERONE OR PROGESTAGENS

Postpartum anestrous cows are usually treated with progesterone/progestagen protocols in order to induce ovulation and sustain pregnancy. In the present work, the efficiency of a protocol (modified GPE), in which temporary calf removal (TCR) and/or administration of eCG, replaced the use of progesterone/progestagens, was evaluated in anestrous animals. Anestrous Nelore cows (40 to 60 days postpartum, n = 22) were randomly allocated to two groups: GPE/eCG and TCR/GPE/eCG. At a random stage of the estrous cycle (D0), animals from Group GPE/eCG were treated with GnRH (50 �g, licereline, i.m., Gestran Plus�; Tecnopec, Sao Paulo, Brazil) and seven days later (D7) they received PGF2� (150 mcg, d-cloprostenol, i.m., Prolise�) and eCG (300 UI, i.m., Novormon�). On D8, estradiol benzoate (EB, 1 mg, Estrogin�; Tecnopec) was administered, and 30 to 36 h afterwards all cows were inseminated at fixed-time (FTAI), without estrus detection. The animals from group TCR/GPE/eCG received the same treatment described above, but with temporary calf removal (during 48 h) before beginning hormonal treatments. The ovaries were examined by ultrasonography (Aloka SSD 500, 7.5 MHz probe) before (D-12, D-2), during (D0, D7, D8), and after (D9, D10, D11, D17, D60) hormonal treatments. The absence of CL, during the ultrasonography performed before starting the treatments, was the criterion used to classify the cows as in postpartum anestrus. Administration of GnRH (D0) induced ovulation (determined by the presence of CL on D7) in 6 of 11 cows (54.5%) from Group GPE/eCG and TCR/GPE/eCG. In relation to synchronization of ovulation after EB administration, in Group GPE/eCG, two cows (18.1%) ovulated until 12 h after FTAI, and four (36.3%) 12 h afterwards (24 h after FTAI). In Group TCR/GPE/eCG, one cow (9%) ovulated approximately 6 h before FTAI, two (18.1%) 12 h after FTAI, and two (18.1%) 12 h afterwards. Preovulatory follicles had a diameter of 11.0 � 1.3 and 11.5 � 2.6 mm in Groups GPE/eCG and TCR/GPE/eCG, respectively. Pregnancy rates, determined by ultrasonograpy 40 to 46 days after FTAI, were 27.2% (3/11) and 45.4% (5/11), respectively. The results indicate that association of TCR with protocol GPE/eCG did not improve synchronization of ovulation or pregnancy rates (P > 0.005). However, increase in pregnancy rates was observed in another experiment with a large number of animals (Pinheiro et al. 2005 Reprod. Fert. Dev. 17, 161, abstr), in which cows from Group TCR/GPE/eCG had higher pregnancy rates (51.5%; 34/66) when compared to animals from Group GPE/eCG (28.3%, 21/74; P < 0.05). This work was supported by FAPESP and by fellowships for A. F. Souza and V. G. Pinheiro from CNPq, Brazil.

18 DO TEMPORARY CALF REMOVAL AND/OR EQUINE CHORIONIC GONADOTROPIN ADMINISTRATION INCREASE PREGNANCY RATES IN LACTATING NELORE COWS TREATED WITH A PROGESTERONE-RELEASE INTRAVAGINAL DEVICE?

Reports indicate that either temporary calf removal or equine chorionic gonadotropin administration can increase the efficiency (pregnancy rate) of hormonal treatments with progestins during postpartum anestrus. This experiment evaluated effects of TCR and/or eCG administration in a protocol with progesterone that is frequently used for fixed-time artificial insemination (FTAI) in cows during postpartum anestrus. The protocols were tested at three farms in lactating Nelore cows (40 to 70 days post-partum, n = 361) with body condition scores from 2.5 to 3.0 (0- to 5-point scale). At a random stage of the estrous cycle (Day 0), animals received a basic PEPE (progesterone-estrogen-prostaglandin-estrogen) protocol with insertion of an intravaginal device with 1.0 g progesterone (DIB�, Syntex, Buenos Aires, Argentina) and an i.m. injection of 2.5 mg of estradiol benzoate (EB, Estrogin�, Farmavet, S�o Paulo, Brazil). Eight days later (Day 8) cows were treated i.m. with 150 mg D-cloprostenol (PGF2� Prolise�, ARSA S.R.L., Buenos Aires, Argentina), and the DIB was removed. Twenty-four hours after DIB removal, cows received 1.0 mg EB i.m. and 30 to 36 h later all animals were FTAIed without estrus detection. Cows were allocated randomly to four groups: PEPE, PEPE/TCR, PEPE/eCG, and PEPE/TCR/eCG. In Group PEPE/TCR, calves were removed temporarily for 54 h (from DIB removal until FTAI). In Group PEPE/eCG, animals received PEPE treatment plus one dose i.m. of 300 UI eCG (Novormon�, Syntex) following PGF2� administration (Day 8). In Group PEPE/TCR/eCG, animals were treated as in protocol PEPE/TCR plus eCG on D8. All animals were examined by ultrasonography (Aloka SSD 500, 7.5 MHz probe) 10 days before and at the beginning of hormonal treatment in order to detect anestrous cows (absence of corpus lutcum in both exams). Pregnancy diagnosis was performed by ultrasonography 30 days after FTAI. The data were analyzed by logistic regression. The following variables were considered in the model and did not affect pregnancy rates: farms, inseminators, and semen (sire). A total of 75% of the animals were in anestrus (absence of CL) and the pregnancy rates were similar (P > 0.05) among the four groups: PEPE (43/85 = 50.6%), PEPE/TCR (42/98 = 42.9%), PEPE/eCG (41/88 = 46%), and PEPE/TCR/eCG (39/90 = 43.3%). The results indicate that in Nelore cows, in postpartum anestrus and good body condition, TCR and/or eCG administration do not improve the efficiency (pregnancy rate) of the PEPE protocol. This work was supported by FAPESP. V.G.P. and A.F.S. received fellowships from CNPq, Brazil.

23 PREGNANCY RATE IN NELORE COWS AFTER TEMPORARY CALF REMOVAL, AND USE OF HORMONAL PROTOCOLS WITH eCG

Both temporary calf removal (TCR) and administration of eCG are potentially useful to improve pregnancy rates in animals treated with fixed-time artificial insemination (FTAI) protocols. In the present work, two experiments were performed to compare the efficiency of eCG and/or TCR in FTAI protocols, with or without exogenous progesterone. In experiment 1, lactating Nelore cows (40 to 70 days post-partum, n = 220) were allocated to two Groups. At a random stage of the estrous cycle (Day 0), animals from Group GPE (GnRH/PGF2α/Estradiol)/eCG were treated with GnRH (50 mg lecireline, i.m.; Gestran Plus®; Tecnopec, Sao Paulo, Brazil). Seven days later (Day 7) they received PGF2α (150 mg D-cloprostenol, i.m.; Prolise®, Tecnopec) and eCG (300 UI, i.m.; Novormon®, Syntex). On Day 8 estradiol benzoate (EB, 1 mg, Estrogin®, Tecnopec) was administered, and 30–36 h later the animals were inseminated (FTAI). In Group DIB (bovine intravaginal device)/eCG an intravaginal progesterone-releasing device (1.0 g, DIB®, Syntex, Buenos Aires, Agrentina; Day 0) was inserted into the vagina of cows and EB (2.5 mg, i.m.) was given in parallel. Eight days later (Day 8), eGC (300 UI, i.m.) and D-cloprostenol (150 mg) were administered. Then the DIB was removed. Twenty-four hour after DIB removal, cows were treated with EB (1.0 mg, i.m.), and 30–36 h later the animals were inseminated (FTAI). Ultrasonographic evaluation of ovaries was performed in all experiments 10 days before and at the beginning of the treatments or TCR, in order to detect the presence of CL. Cows from Group DIB/eCG showed higher pregnancy rates than those from Group GPE/eCG (58%, 72/124 vs. 39.5%, 38/96, respectively, P < 0.01). Furthermore, only in Group GPE/eCG were pregnancy rates higher in animals with CL (47.6%, 20/42) when compared to those without CL (33%, 18/54, P < 0.05). In a second experiment, a possibly beneficial effect of TCR on GPE/eCG protocol was tested in lactating Nelore cows (40 to 70 days postpartum, n = 140). Animals of Group GPE/eCG (control) were treated as described above, whereas calves were removed for 48 h from cows in Group RTB/GPE/eCG prior to hormonal treatments. Lactating Nelore cows having their calves removed showed a significant increase in pregnancy rates compared to those without TCR (51.2%, 34/66 v. 28.4%, 21/74, respectively, P < 0.01), in both situations: animals with CL (54.8%, 17/31 v. 33.3%, 11/33, respectively, RTB/GPE/eCG v. GPE/eCG) or without CL (48.5%, 17/35 v. 24.3%, 10/41, respectively, RTB/GPE/eCG v. GPE/eCG). In conclusion, these results indicate that addition of eCG to the GPE protocol was not efficient enough to produce comparable results to those obtained with DIB/eCG protocol. However, calf removal before the GPE/eCG treatment increased pregnancy rates in cycling or anestrous (without CL) lactating Nelore cows.

Effects of temporary nest box removal on maternal behaviour and pup survival in caged rabbits ( Oryctolagus cuniculus)

Free nest access is widely used in the management of commercial breeding units for fattening rabbits, but potentially counteracts the doe's behavioural goal of a closed nest entrance, leading to repeated nest visits without nursing and attempts to close the entrance due to an overtaxed adaptability. Due to injuries, crushing and hypothermia caused by such behavioural problems, pup mortality can be more than 20% under these circumstances. To study the effect of nest access on doe's nest related behaviour, pup mortality and pup weight, three groups of 10 does each had either free access (‘F’), controlled access with the entrance closed with a sliding door (‘S’) or controlled access with the nest box removed outside nursing time (‘R’). In groups with controlled access, nursing was admitted for 15 min each morning from day 1 to 15. Behavioural data were achieved from does rearing a second litter (7 does per group) and included the general activity and the frequency, intensity and temporal distribution of nest approaches, including investigations of the nest entrance (‘entrance checks’) or of the nest and pups (‘nest checks’) and nesting activities (nest opening and closing behaviour). Data on pup mortality, causes of death and pup weights were gained from 62 litters over three consecutive reproductive cycles. Over 24 h, group F showed significantly more short nest approaches than group R, whereas group S performed significantly more medium length approaches than group R and more long approaches than R and F. In the hour after nursing and outside nursing hours, group F showed significantly more nest checks than S and R. Group S performed significantly more entrance checks in the hour after nursing, more nesting activities before and outside nursing and the highest general activity. Outside nursing hours, group R showed the lowest frequency of nest approaches and nesting activities. Nesting activities were distributed over almost all 24 h a day in groups F and S, whereas they were more restricted to nursing time in group R. Pup mortality and weaning weights did not differ significantly between groups.

Extra-abdominal versus intra-abdominal repair of the uterine incision at caesarean section

Different techniques have been described to reduce morbidity during caesarean section. After the baby has been born by caesarean section and the placenta has been extracted, temporary removal of the uterus from the abdominal cavity (exteriorisation of the uterus) to facilitate repair of the uterine incision has been postulated as a valuable technique. This is particularly so when exposure of the incision is difficult and when there are problems with haemostasis. Several clinical trials have been done, with varying results, including substantial reduction in the rate of postoperative infection and morbidity with extra-abdominal closure of the uterine incision, and less associated peri-operative haemorrhage. Subsequent studies suggest that the method of placental removal rather than method of closure of the uterine incision influences peri-operative morbidity. To evaluate the effects of extra-abdominal repair of the uterine incision compared to intra-abdominal repair. We searched the Cochrane Pregnancy and Childbirth Group trials register (September 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2003), MEDLINE (1966 to July 2003) and PubMed (1966 to 2003). Randomised controlled trials involving a comparison of uterine exteriorisation with intra-abdominal repair of the uterine incision in women undergoing caesarean section. Two reviewers independently assessed the trials identified for inclusion. We compared categorical data using relative risks and 95% confidence intervals and continuous data using the weighted mean difference with 95% confidence intervals. We tested for statistical heterogeneity between trials using the I squared test. Where no significant heterogeneity (greater than 50%) existed, we pooled data using a fixed effect model. If significant heterogeneity existed, a random effects model was used. Six studies were included, with 1294 women randomised overall, and 1221 women included in the analysis. There were no statistically significant differences between the groups in most of the outcomes identified, except for febrile morbidity and length of hospital stay. With extra-abdominal closure of the uterine incision, febrile morbidity was lower (relative risk 0.41, 95% confidence interval (CI) 0.17 to 0.97), and the hospital stay was longer (weighted mean difference 0.24 days, 95% CI 0.08 to 0.39). There is no evidence from this review to make definitive conclusions about which method of uterine closure offers greater advantages, if any. However, these results are based on too few and too small studies to detect differences in rare, but severe, complications.

Managerial decisions as experiments: an opportunity to determine the ecological impact of boat-generated waves on macrobenthic infauna

A previous correlative study showed that assemblages of macrobenthic infauna and abundances of common taxa on intertidal mudflats differed between a no-wash zone, where ferries had to minimize production of wash, and places where the production of wash was unrestricted (wash zone). This suggested that boat-generated waves (wash) are important in determining the structure of these assemblages. Causality between wash and the observed patterns could not, however, be unambiguously established, due to the absence of ‘before’ data. Here, a managerial decision to stop ferry services on the upper Parramatta River, Sydney, Australia during the 2000 Olympics was used as the basis for a manipulative experiment to examine the effects of changes in the amount of wash on these fauna. It was hypothesized that if wash is important in structuring infaunal assemblages, assemblages in the wash zone would become more similar to those of the no-wash zone following removal of the disturbing force, i.e. the ferry service. Similarly, if the smaller abundances of capitellids, nereids and spionids in the wash zone are caused by this disturbance, abundances should increase in the wash zone during the stoppage and decrease following the return of services. As hypothesized, assemblages within the wash zone became more similar to those of the no-wash zone following the temporary removal of the ferry services. Following the return of ferries, assemblages changed back towards (although not reaching) their previous state. Abundances of the polychaete families Nereididae, Capitellidae and Spionidae also increased at some sites during the cessation, although this pattern was not found in all sites and there was no general response to the cessation of wash as had been predicted. These results indicate that wash is important in structuring assemblages of macrobenthic infauna, although responses of individual taxa are more idiosyncratic. More importantly, they show that manipulations, resulting from managerial decisions, can be treated as testable hypotheses and utilized by scientists as experiments to test for causal relationships.

Temporary removal of navel piercing jewelry for surgery and imaging studies.

Navel piercings are becoming increasingly popular among adolescents. Body piercing jewelry must be removed before surgery, because electrical burns can occur with electrocauterization. Also, piercing jewelry creates artifacts during magnetic resonance imaging. Even temporary piercing jewelry removal may lead to closure of the subcutaneous tract; therefore, temporary replacement with a nonmetallic spacer is indicated. This report describes a simple, safe, effective method for perioperative temporary replacement of navel piercing jewelry with a universally available, nonmetallic, sterile, intravenous catheter. The umbilical piercing jewelry of 5 adolescent female patients was removed before surgical or radiologic interventions by using the following technique: 1) disinfecting the piercing and umbilical area with 70% isopropyl alcohol, 2) opening the piercing jewelry by removing the bead from the bar, 3) placing the tip of a tight-fitting intravenous catheter (14 or 16 gauge, without the needle) over the threaded tip of the bar, 4) advancing the intravenous catheter caudally, pushing the piercing out of the skin tract, and 5) removing the jewelry and leaving the intravenous catheter in the subcutaneous skin tract as a spacer. After the intervention, the piercing jewelry was reinserted by following the described steps in reverse order. The patients were evaluated after 1 week, for assessment of any adverse effects, including infection. With this method, piercing jewelry removal and reinsertion required <2 minutes for all patients. No procedural complications were noted. All jewelry was reinserted successfully after the procedure. The intravenous catheter left in situ did not interfere with surgery, and it did not produce any artifacts or adverse effects during magnetic resonance imaging. Follow-up evaluations at 1 week demonstrated no signs of irritation, infection, or other side effects of the procedure for any of the patients. Periprocedural removal of navel piercing jewelry with this new technique proved to be quick, feasible, and safe. Piercings in other locations on the body may be replaced for surgery or imaging studies in the same way, with minor modifications.

Retrograde mastoidectomy with canal wall reconstruction: a follow-up report.

To evaluate long-term results of retrograde mastoidectomy with canal wall reconstruction as a single-stage technique for cholesteatoma removal. Retrospective case review. Tertiary referral center. Forty-six patients, representing 50 ears (20 pediatric and 30 adult), who had undergone surgery for cholesteatoma removal with said technique and had an average follow-up of 7.8 years. Temporary removal of the upper canal wall, in association with a retrograde-type mastoidectomy, for full exposure and extirpation of the disease, followed by reconstruction of the canal defect using cymba cartilage. Preoperative and short- and long-term postoperative audiogram, obtained as four-frequency pure-tone average air-bone gap. Complications, including presence of recurrent or residual cholesteatoma, need for tube insertion, perforation, and poor hearing requiring revision surgery, were also reported and correlated with the patient's tobacco use. The average preoperative, short-term postoperative, and long-term postoperative pure-tone average air-bone gap was 25.6+/-11.2 dB, 11.0+/-5.7 dB, and 12.4+/-6.4 dB, respectively. There were significant differences between the pre- and postoperative values (p < 0.5), but there was no significant difference between short- and long-term hearing results. Recurrent cholesteatomas were seen in eight ears (16%); pressure-equalizing tube insertion was performed postoperatively in nine ears (18%); a perforation was seen in one ear (2%); and two ears (4%) had poor hearing results requiring second-look surgery. The long-term complication rate of smokers was 79% (15 of 19), compared with 16% (5 of 31) for nonsmokers. This single-stage technique for cholesteatoma removal and canal wall reconstruction showed acceptable long-term results, but tobacco use was associated with a higher long-term complication rate.

INFLUENCE OF DENSITY ON THE SPATIAL BEHAVIOR OF FEMALE THIRTEEN-LINED GROUND SQUIRRELS, SPERMOPHILUS TRIDECEMLINEATUS

We tested the hypotheses that intrasexual aggression among female thirteen-lined ground squirrels (Spermophilus tridecemlineatus) varies with female density and that females defend home burrows and surrounding areas. Independent of density, females used and maintained 1 home burrow preferentially. The frequencies of aggressive encounters and displays initiated by females in high-density populations were 6 and 4 times higher, respectively, than that initiated by females living at low density. In high-density populations, the average overlap of female home ranges was only 13% of home range area, suggesting female defense of these areas (territoriality). Furthermore, most aggressive encounters were initiated when females were within their territory borders. Females displaced opponents in 80.6% of these encounters, whereas they prevailed in only 26.3% of aggressive encounters initiated outside of territory borders. In experiments involving the temporary removal of individual females, 1 or more neighboring females began using the territory of the removed female, and the frequency of both encounters and displays increased during removals. Upon their return, removed females reestablished their original territories by displacing the responding neighbors. Our results indicate that female S. tridecemlineatus defend territories surrounding a home burrow site, and that intrasexual aggression relegates some females to less preferred areas.

Generalized estimators of avian abundance from count survey data

I consider modeling avian abundance from spatially referenced bird count data collected according to common protocols such as capture-recapture, multiple observer, removal sampling and simple point counts. Small sample sizes and large numbers of parameters have motivated many analyses that disregard the spatial indexing of the data, and thus do not provide an adequate treatment of spatial structure. I describe a general framework for modeling spatially replicated data that regards local abundance as a random process, motivated by the view that the set of spatially referenced local populations (at the sample locations) constitute a metapopulation. Under this view, attention can be focused on developing a model for the variation in local abundance independent of the sampling protocol being considered. The metapopulation model structure, when combined with the data generating model, define a simple hierarchical model that can be analyzed using conventional methods. The proposed modeling framework is completely general in the sense that broad classes of metapopulation models may be considered, site level covariates on detection and abundance may be considered, and estimates of abundance and related quantities may be obtained for sample locations, groups of locations, unsampled locations. Two brief examples are given, the first involving simple point counts, and the second based on temporary removal counts. Extension of these models to open systems is briefly discussed.

19POSTPARTUM ANESTROUS TREATMENT WITH INTRA-VAGINAL PROGESTERONE DEVICE OR CALF REMOVAL FOR 120 HOURS IN SUCKLED CROSSBRED DUAL PURPOSE COWS

Postpartum anestrus is the main reproductive problem that affects crossbred cattle production in Venezuela. (Soto et al., 2002 Theriogenology 57, 1503–1510; Soto et al., 2000 Revista Científica FCV-LUZ 10, 391–398). In order to reduce the postpartum anestrus and lower the calving to conception interval, 167 crossbred (Bos indicus×Bos taurus) anestrous cows between 90 and 130 days postpartum with body condition score 3 (scale 1–5) were randomly allotted to one the following treatments: 1) PH (n=59), intravaginal sponge (IS) impregnated with 250mg of medroxyprogesterone acetate (MAP) during 7 days+50mg of MAP and 5mg of 17β-estradiol (17β-E) i.m. at the day of sponge insertion (Day 0), plus 500 IU of eCG i.m. at Day 5 and1.5mg of 17β-E i.m. at Day 8 (PREGNAHEAT-E, VIATECA, Villa del Rosario, Venezuela); 2) CR (n=57), 120-h temporary calf removal; and 3) CG (n=20), control group. Work was performed in a commercial farm located in a subhumid tropical forrest region. Estrus, first service conception and pregnancy rate were analyzed by chi-square analysis. The intervals to conception were analyzed using analysis of variance (GLM) and the means was compared by least square means method. To evaluate the treatment effect, the interval to conception of each pregnant cow during the first 100 days were considered for the analysis. This interval (days) was significantly (P≤0.05) higher in the PH treatment (155.9±7.3) compared to control (174.4±8.1) but no differences were shown between PH and CR (161.0±7.8). Other results are shown in Table 1. PH treatment improved the estrus and pregnancy rates and shorten the interval to conception indicating that this is a promising anestrous treatment for suckled crossbred dual purpose cows under tropical conditions. Table 1. Reproductive performance of postpartum anestrous suckled cows treated with intravaginal progesterone or temporary calf removal

Arene Substitution Involving Temporary Incorporation and Removal of Carbon Tethers via Carbopalladation and Decarbopalladation

Arene Substitution Involving Temporary Incorporation and Removal of Carbon Tethers via Carbopalladation and Decarbopalladation

Follicular growth and ovulation in postpartum beef cows following calf removal and GnRH treatment

This study investigated the effects of calf removal (CR) and gonadotrophin releasing hormone (GnRH) administration on the duration of the postpartum anoestrous period in suckled beef cows. Experiment 1 involved 20 multiparous suckled cows that were assigned to each of two treatments on Day 61 postpartum: (i) unlimited access to their calves (C; n=10) and (ii) calf removal for a period of 96 h (CR96, n=10). Experiment 2 involved 24 multiparous cows that were assigned to each of two treatments on Day 63 postpartum: (i) CR96 ( n=12); and (ii) CR96 plus 250 μg of GnRH administered on the day before calf return (CR96+GnRH, n=12). Experiment 3 was a 3×2 factorial experiment, involving 48 multiparous cows assigned to the experiment on Day 58 postpartum. The factors were C, CR96 and calf removal for 144 h (CR144), and 0 or 250 μg GnRH administered on the day prior calf return. In Experiment 1, the number of cows that ovulated within 12 days of calf removal was higher ( P<0.05) in CR96 group (3/9) compared to the C group (0/10). In Experiment 2, all 12 cows in the CR96+GnRH group ovulated. In contrast only 4/12 cows in the CR96 group ovulated in response to calf removal. The diameter of the ovulatory follicle tended ( P=0.06) to be smaller in CR96+GnRH cows (9.8±0.3 mm) than in CR96 cows (11.3±0.9 mm). The maximum diameter attained by the corpus luteum (CL) also tended ( P=0.08) to be smaller for cows in the CR96+GnRH than for cows in the CR96 group (12.1±2.4 mm versus 16.7±7.5 mm, respectively). Plasma progesterone concentrations 12 days after calf removal tended ( P=0.06) to be lower in CR96+GnRH cows than in CR96 cows (0.66±0.1 ng/ml versus 2.00±1.1 ng/ml, respectively). Few cows in the CR96+GnRH group regained normal cyclical activity and the interval from onset of calf removal to conception was longer ( P<0.05) compared to cows in the CR group (52.2±5.7 days versus 20.0±6.6 days). In Experiment 3, 5/8 cows on the CR144 group and all 8 cows in the CR144+GnRH group ovulated. However, the interval from CR to conception was similar for all treatments. Temporary (96–144 h) calf removal, particularly in combination with GnRH treatment, can induce a high proportion of beef cows to ovulate, but the restoration of oestrous cycles may not be achieved.

Forcing Chromatin

Forcing Chromatin

RESOURCE-DEPENDENT INTERACTIONS AND THE ORGANIZATION OF DESERT ANT COMMUNITIES

Resources influence consumer physiology, behavior, population growth, interspecific interactions, and community structure. To understand fully the influence of resources on interactions among consumer populations and community structure, it may be necessary to understand the influence of resources on individual behavior. In the first part of this study, we examined how resource type influenced foraging behavior and interactions in a guild of omnivorous desert ants. Cafeteria experiments showed that Myrmecocystus depilis, M. mimicus, and Aphaenogaster cockerelli prefer protein resources to seed resources. However, A. cockerelli collects mostly seed resources, and M. depilis and M. mimicus collect mostly protein resources when faced with competition from one another. A temporary removal experiment showed that the effect of M. mimicus and M. depilis on A. cockerelli depended on resource type. At protein resources, Myrmecocystus foragers tended to displace A. cockerelli foragers, but at seed resources, there ...

Antinutritional effects of fumonisin B 1 and pathophysiological consequences

Due to its structural similarity with sphingosine, fumonisin B 1 (FB 1) inhibits ceramide synthase (a key enzyme of sphingolipid biosynthesis) leading to an intracellular accumulation of sphingoid bases with a consequent increase of sphinganine/sphingosine (SA/SO) ratio. In adult male rats, dietary exposure to fumonisin induces a significant increase in both SA concentrations and SA/SO ratio in kidney, but not in liver and brain, as well as a significant reduction of body weight gain. Regarding the brain, the developing rat is more sensitive to FB 1 than the adult rat. FB 1 treatment produces in the forebrain and brainstem: (i) an increase in SA levels and SA/SO ratio, (ii) a reduction in myelin deposition, and (iii) an impairment of 2′,3′-cyclic nucleotide 3′-phosphohydrolase (CNP) activity. FB 1 effects on myelin are similar to those produced by starvation (temporary removal of pups from dam during postnatal period), thus suggesting that hypomyelination could be due, at least partly, to a nutritional deficiency. Finally, FB 1 reduces the uptake of folate in different cell lines. The resulting folate deficiency could explain the association of FB 1 exposure with neural tube defects.

FLOW EVALUATION OF STENTS IN CAROTID ARTERY MODELS

Age-related macular degeneration (AMD) is the leading cause of legal blindness in the western nations beyond 50 years of age. The most frequent cause for severe visual loss is the growth of neovascular membrances from the choroid into the subretinal space. This usually results in irreversible degeneration of the overlying retina. Surgical removal of the membrane is feasible, however, usually results in functional loss of apposing retinal photoreceptors since retinal pigment epithelial (RPE) cells are removed concurrently due to their tight adherence to the neovascular complex. Therefore, various attempts have been undertaken to fill the resulting RPE cell defect with either heterologous or autologous RPE cell transplants. So far cell survival, function and subsequent visual function has been disappointing. To minimize trauma and resulting dedifferentiation harvesting in the eye and transplantation in whole sheets and without temporary removal from the eyes would be desirable. This may be achieved by isolating grafts consisting of choroid, Bruch's membrance and RPE cells from the peripheral retina and transplantation of this graft under the neurosensory retina after removal of the choroidal neovascularization. However, the choroidal component of such a graft would be expected to interfere with diffusion of metabolites to and from the retina. Therefore, outcome would be expected to be better if the choroidal tissue would be removed before translocation. In preclinical experiments we used a 308 nm UV AIDA excimer laser to microablate choroidal tissue from such a graft in human donor eyes.

Safety and security policies on psychiatric acute admission wards: results from a London-wide survey.

Very little research evidence is available regarding current safety and security procedures on acute psychiatric wards. This includes controversial areas such as the temporary removal of personal property, the searching of patients and visitors, the use of alarms and modern technology, and locking of entrances to regulate those entering and leaving. This is also despite widening dismay over increasing violence within a variety of hospital settings, the comparatively high risk of physical assault faced by mental health professionals and an abundance of literature and training in regards to violence management and prevention. To gain an understanding of current safety and security measures, a London-wide survey of acute admission wards was undertaken revealing a wide variety of measures and policies in operation. Over 100 NHS and private wards were sent questionnaires; there was a response rate of 70%. Results show that a significant proportion of acute admission wards are now locked at all times and a small proportion of units have 24-hour security/reception staff on-site and a low level of modern technology usage such as CCTV and electronic access systems. There is wide variation in items banned, restrictions placed on inpatients, and the searching of patients and visitors. Two independently varying emphases of ward security policies were identifiable, the first aimed at preventing harm to patients using door security, banning of item and restrictions on inpatients. The other is aimed at reducing risks to staff via searching of patients, use of security guards and sophisticated alarm systems. There is some preliminary evidence that these security policies are differentially associated with levels of absconding and violent incidents. Further research to guide practice is urgently required.