Evaluation of the degradation of two bioabsorbable interference screws: an in-vivo study in sheep

PURPOSE

To evaluate in-vivo degradation of two bioabsorbable interference screws.

METHODS

Twenty-two crossbred Santa Inês ewes were used. A poly-DL-lactide (PDLLA) screw (70%/30%) was inserted in the right pelvic limb, and a PDLLA screw (70%) + β-tri-calcium phosphate (β-TCP) (30%) in the left pelvic limb. Animals were euthanized at one, four, seven and a half and 18 months after surgery. Plain radiography, computed tomography (CT), microCT, and histological analysis were accomplished.

RESULTS

PDLLA screw was hypodense at all evaluation moments, but with progressive density increase along the central axis, whereas PDLLA/β-TCP was initially hyperdense and progressively lost this characteristic. No adverse reactions were observed on histological evaluation.

CONCLUSIONS

The inclusion of β-TCP favors screw degradation since the PDLLA/β-TCP screws evidenced a more intense degradation process than the PDLLA screws at the last evaluation. PDLLA screws showed higher bone production, evident around the screw thread, inside the lateral perforations, and in the central canal, whereas the PDLLA/β-TCP screws presented less bone tissue at the implantation site.

Serological survey and DNA screening of Leptospira spp. in free-living adult tufted capuchin monkeys (Cebus apella nigritus) in a forest reserve Southeast São Paulo State, Brazil

BACKGROUND

Leptospirosis is an important anthropozoonosis. The study investigated the presence of anti-Leptospira antibodies and detection of Leptospira spp DNA in the urine as well as the biochemical profile in Neotropical wild primates living in a forest reserve from Southeast São Paulo State, Brazil.

METHODS

Blood samples were obtained from 50 adult tufted capuchin monkeys (Cebus apella nigritus). Urine samples were obtained only from male primates. The screening for antibodies against Leptospira spp was evaluated by microscopic agglutination test (MAT). Leptospira DNA in the urine was evaluated by polymerase chain reaction (PCR) considering the target gene LipL32. Biochemical profile was evaluated by using a spectrophotometer.

RESULTS

The MAT results included 39 (78%) serum reactive animals with the proportions of 28/39 males and 11/39 females. The most frequent reactive serogroups were Icterohemorrhagiae, Canicola, and Autumnalis. All urine samples were negative for leptospiral DNA. There were no significant differences between sexes for aspartate aminotransferase (AST) and alkaline phosphatase values, but alanine aminotransferase (ALT), creatinine, glucose, and urea were significantly higher in males.

CONCLUSIONS

Tufted capuchin monkeys were sera reactive against leptospirosis. Prevalence was similar for the 2 sexes. Leptospiral DNA was not detected in the urine of sera reactive primates tested by the MAT method. ALT, creatinine, glucose, and urea values were higher in male animals.

120 Use of fixable dyes to analyze equine sperm membrane integrity and acrosome reaction after A23187 treatment

Conventional IVF is not successful in the horse, and current work is focused on factors affecting sperm capacitation in this species. Challenges arise in assessing equine sperm incubated in media containing capacitation promotors, as some of these factors cause sperm head-to-head binding (aggregation). Our preliminary microscopic findings showed that sperm aggregates are largely of viable sperm, whereas nonviable sperm individualize. Thus, data obtained using technologies that analyse only individual cells and gate out aggregates, such as flow cytometry, may not accurately represent the study population. We developed a fixable live/dead/acrosome staining protocol (LD-PSA) that minimizes sperm aggregation. The aim of this study was to evaluate the percentage of viable and acrosome-reacted equine sperm after A23187 treatment, using either LD-PSA or a standard staining protocol (PI-PSA). Sperm from 9 ejaculates were suspended in Hanks’ balanced salt solution (HBSS) and exposed for 10min at 37°C to vehicle (V) or to 10 µM A23187 (C10). The sperm were washed, resuspended in HBSS medium with added lactate and pyruvate and containing 7mgmL−1 of bovine serum albumin (BSA), and assessed immediately (0h) or incubated at 37°C for 2h (the period needed for equine sperm to respond to A23187). Motility was analysed using computer-assisted semen analysis. Each treatment was stained by PI-PSA: propidium iodide and fluorescein isothiocyanate-Pisum sativum agglutinin (PSA) in DPBS; and by LD-PSA: Live/Dead Fixable Red, paraformaldehyde 2%, Triton×1%, and FITC-PSA in Dulbecco's phosphate-buffered saline with Accumax (Stem Cell Technologies), a commercial proprietary cell agglutination inhibitor, before flow cytometric analysis. Differences were analysed using repeated-measures two-way ANOVA. The% total motile sperm (TMOT) for V and C10 treatments were 76.3±3.0 and 71.2±4.7 at 0h (P>0.05), and 70.5±14.8 and 2.4±0.8 at 2h (P<0.05). On flow cytometry, the percentage of events outside the gate for V sperm (0h and 2h combined) was 31.9% in PI-PSA and 21.9% in LD-PSA samples (P<0.01). Measured viability in V samples was significantly lower when stained with PI-PSA than with LD-PSA at 0h (49.2±4.6 vs. 67.1±4.9) and tended to be lower (P=0.07) at 2h (44.0±4.9 vs. 55.1±2.8). Notably, the viability recorded in PI-PSA was 26 percentage points lower than was the TMOT at both 0h and 2h, indicating nonrepresentative results, as nonviable sperm should not be motile. By LD-PSA, this difference was 9 points at 0h and 15 points at 2h. Vehicle sperm showed significantly higher AR values in PI-PSA than in LD-PSA at 0h (30.4±4.0 vs. 17.7±2.4) and 2h (41.9±4.5 vs. 24.0±1.8), as did C10 sperm at 0h (28.9±2.7 vs. 18.0±2.5). The lower values for viability than total motility likely reflect agglutination of viable sperm and thus their exclusion from analysis on flow cytometry. The anti-clumping measures employed in the LD-PSA protocol were associated with increased correspondence of measured viability with TMOT. Thus, LD-PSA may offer a more accurate technique to assess viability and acrosome status of equine sperm incubated in capacitating conditions.

121 Effect of pentoxifylline on motility of good- and poor-quality frozen-thawed equine sperm

Equine semen used for intracytoplasmic sperm injection (ICSI) is typically frozen-thawed and may be of poor quality. To prepare sperm for ICSI, semen is typically centrifuged to remove freezing extender. However, centrifugation can cause damage to sperm, which is especially meaningful if sperm quality is already poor. We evaluated a method for selection of sperm without centrifugation, using a “swim-over” technique, and assessed the effect of pentoxifylline, a phosphodiesterase inhibitor that increases sperm motility in other species. To mimic poor-quality semen, we thawed frozen semen (1×) and re-froze it three additional times (4×). Aliquots (0.25 µL; 50,000 sperm) of 1× or 4× semen were placed at the bottom of the right leg of an “H,” made using 15µL of medium by tracing a template placed below a Petri dish. The medium used (Hanks’ balanced salt solution with 40mg mL BSA and added lactate and pyruvate) contained different concentrations of pentoxifylline (0, 0.5, 1, 2 or 4mgmL−1). One µL of medium was removed from the tip of the left arm of the H after 15 and 30min incubation, and the number of sperm were counted. In a second study, we evaluated the effect of pentoxifylline on sperm motility parameters using computer-assisted sperm motility analysis. After thawing, 1× and 4× semen was washed to remove freezing extender and resuspended in the same medium but with 7mgmL−1 bovine serum albumin (BSA), containing the different pentoxifylline concentrations. In Study 1, the number of collected sperm did not differ significantly for 1× sperm exposed to 0 to 4mgmL−1 pentoxifylline (means of 15 to 23 sperm at 15min, and 18 to 25 sperm at 30min). Similarly, in 4× frozen semen, there was no significant difference in number of collected sperm between 0mgmL−1 and 2 or 4mgmL−1 pentoxifylline concentrations (<1 to 6 at 15 min; 5 to 6 at 30min). In Study 2, at 0min,% total motility was significantly higher in 1 and 2mgmL−1 pentoxifylline than in 0mgmL−1 for 1× sperm (47.8±1.7 and 49.3±1.9, vs. 32.1±3.9, respectively; P=0.018) and significantly higher for 1, 2, and 4mgmL−1 pentoxifylline than for 0mgmL−1 for 4× sperm (3.9±0.9, 5.7±0.4, and 8.2±0.5, vs. 1.2±0.4; P=0.0001). Similar results were found at 15 and 30min for 1×, and at 15min for 4×. Pentoxifylline at 1 to 4mgmL−1 significantly increased the percentage of progressive motility in 1× sperm at 30min (17.8±1.3, 21.8±2.7, and 20.3±1.2, vs. 10.0±0.4; P=0.002) and, at 4mgmL−1, increased the percentage of progressive motility in 4× sperm at 0min (1.43±0.1 vs. 0.2±0.1; P=0.005) and 15min (1.4±0.2 vs. 0.1±0.0; P=0.0001). Exposure of poor-quality semen to pentoxifylline at 4mgmL−1 improved total and progressive motility but did not increase the recovery of motile sperm in a swim-over collection preparation.

139 Effect of protein and calcium ionophore A23187 concentration on hyperactivated motility and acrosome status of stallion sperm

In vitro fertilization does not occur readily in the horse. Fertilization can be achieved using sperm treated with the calcium ionophore A23187 (CaI), but rates are low and variable. In order to fertilize, it is thought that the sperm must show hyperactivated motility and undergo the acrosome reaction. The presence of protein in the media is thought to suppress the effect of CaI, but protein is needed for maintenance of sperm motility. Therefore, the objective of this study was to assess the effect of CaI in the presence or absence of protein on the acrosome and on hyperactivated motility of equine sperm. For this purpose, sperm from 4 stallions were exposed for 10min at 37°C to vehicle or to 1 (C1), 5 (C5) or 10 (C10) μM CaI, with (BSA) or without (N) 7mg mL−1 BSA. The sperm were then washed and incubated at 37°C for 2h. Total and hyperactivated motility were measured by computer-assisted semen analysis. Sperm were considered hyperactivated if curvilinear velocity was >180μm s−1, amplitude of lateral head displacement was >12μm, linearity was <30% and fractal dimension value was >1.3. The percentage of live acrosome-reacted sperm was measured by flow cytometry after staining with propidium iodide and Pisum sativum agglutinin. Data were analysed by repeated-measures 2-way ANOVA. Results were expressed as mean±standard error. Total motility in C5 and C10 treatments was significantly decreased in relation to control (BSA-vehicle) starting at 30min of incubation (35.42±13.57 to 28.20±13.10% v. 71.72±9.21%, respectively; P<0.05). Hyperactivated motility was significantly lower in C10, C5 and N-C1 than in control after 2h of incubation (1.46±0.64v. 3.10±0.58%, respectively). Live acrosome-reacted sperm were significantly higher (P<0.05) for BSA-C5 (14.04±1.99%) and BSA-C10 (14.85±2.52%) than for control (7.50±1.62%) after 2h of incubation. The exposure to sperm of concentrations ≥5μM CaI was associated with loss of motility from 30min of incubation on. However, 2h of incubation after ≥5 μM CaI in the presence of BSA were needed to increase the percentage of live acrosome-reacted sperm. This mismatch between motility and acrosome response helps to clarify the reasons for the variable effect of sperm CaI treatment on equine IVF. Further studies measuring calcium influx and assessing the effect of sperm pre-incubation on CaI response are needed to explore mechanisms for equine in vitro sperm capacitation.

Etiology of chronic urticaria: the Ecuadorian experience

Background

The purpose of this study was to identify chronic urticaria (CU) etiologies and treatment modalities in Ecuador. We propose that the sample distribution fits the expected one, and that there is an association between the etiology and its treatment.

Methods

We performed a retrospective study involving 112 patients diagnosed with CU using a Checklist for a complete chronic urticaria medical history. Demographic and clinical variables were collected. The etiology of CU was classified using the EAACI/GA2LEN/EDF/WAO guideline. Descriptive analyses were performed for demographical and clinical variables. Chi square tests were applied to analyze the fit of distribution and the independence of variables. P values less than 0.05 were considered significant.

Results

Among all the patients, 76.8% were diagnosed with chronic spontaneous urticaria (CSU), of which 22.3% had a known etiology or possible exacerbating condition. Food allergy was identified as the most common accompanying condition in patients with CSU (10.7%) (p < 0.01).. On the other hand, 23.2% inducible urticarias (CIndU) were indentified; dermographism was the most common (10.7%) (p < 0.01).

Regarding treatment regimens, sg-H1-antihistamines alone represented the highest proportion (44.6%). The combination of any H1-antihistamine plus other drug was a close second (42.0%) (p < 0.01). Almost 48% of CSUs of unknown etiology were treated with any antihistamine plus another drug. In patients with known etiology, sg-antihistamines alone (44.0%) was the most common management. In addition, 53.8% of CIndUs were treated with sg-antihistamines alone. Though, these associations were not statistically significant.

Conclusion

CSU is the most frequent subtype of CU. Modern non-sedating antihistamines in licensed doses are the drug of choice. Nevertheless, a great proportion of patients require the addition of another type of medication.

What kind of information and communication technologies do patients with COPD prefer to use? A cross-sectional study in Latin America

The aim of the present study was to assess the frequency of uses and preferences of information and communication technologies (ICTs) among Latin American chronic obstructive pulmonary disease (COPD) patients. We conducted an anonymous cross-sectional survey study on Latin American COPD patients. The adapted version of the Michigan questionnaire was employed in eligible outpatients in different cities of Latin America. We categorized age and educational levels into three groups. The time passed since COPD diagnosis was categorized as ≤5 years and >5 years. χ² and crude and adjusted logistic regressions were performed. A total of 256 patients were enrolled with a mean age of 68.7 years old. The most recurrently used ICTs were short message service (SMS; 47.1%) and WhatsApp (30.7%) for receiving COPD information. Moreover, SMS (85.8%) and Facebook (36.1%) were rated as useful for asking physicians information about COPD. Regression analysis showed that the best predictor for patients using ICTs, for any purpose, was higher education (undergraduate or graduate school). Understanding the preferences of ICTs among COPD patients could help improve patient’s outcomes through developing applications in response to specific requirements of each patient.

Experimental constraints on shear mixing rates and processes: implications for the dilution of submarine debris flows

Submarine debris flows show highly variable mixing behaviour. Glacigenic debris flows travel hundreds of kilometres along the sea floor without undergoing significant dilution. However, in other locations, submarine slope failures may transform into turbidity currents before exiting the continental slope. Rates and processes of mixing have not been measured directly in submarine flow events. Our present understanding of these rates and processes is based on experimental and theoretical constraints. Significant experimental and theoretical work has been completed in recent years to constrain rates of shear mixing between static layers of sediment and overlying turbulent flows of water. This work was driven by a need to predict transport of fluid mud and the erosion of cohesive mud beds in shallow water settings such as estuaries, docks and shipping channels. These experimental measurements show that the critical shear stress necessary to initiate shear mixing (around 0.1 to 2 Pa) is typically several orders of magnitude lower than the yield strength of the debris. Shear mixing should initiate at relatively low velocities (about 10–200 cm s−1) on the upper surface of a submarine debris flow, at even lower velocities at its head (about 1–10 cm s−1), and play an important role in mixing over-ridden water into the debris flow. Addition of small amounts of mud (approximately 3% kaolin) to a sand bed dramatically reduces the rate of mixing at its boundary, and changes the processes by which sediment is removed. Estimates are presented for rates of shear mixing at a given flow velocity, and for the critical velocity necessary for hydroplaning or a transition from laminar to turbulent flow. Although these estimates are crude, and highlight the need for further experimental work, they illustrate the potential for highly variable mixing behaviour in submarine flow events.

European Resuscitation Council Guidelines 2000 for Basic Paediatric Life Support. A statement from the Paediatric Life Support Working Group and approved by the Executive Committee of the European Resuscitation Council

The European Resuscitation Council (ERC) last issued guidelines for Paediatric Life Support (PLS) in 1998 [1]. These were based on the "Advisory Statements" of the International Liaison Committee on Resuscitation (ILCOR) published in 1997 [2]. Following this, the American Heart Association, together with representatives from ILCOR, undertook a series of evidence-based evaluations of the science of resuscitation which culminated in the publication of "Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" in August 2000 [3,4]. The Paediatric Life Support Working Party of the European Resuscitation Council has considered this document and the supporting scientific literature and has recommended changes to the ERC Basic PLS guidelines. These are presented in this paper. There have been few major changes to the ERC recommended guidelines as some of the changes agreed in "Guidelines 2000" had already been introduced into Europe subsequent to the 1998 ILCOR "Advisory Statements" (Fig. 1).

European Resuscitation Council Guidelines 2000 for Advanced Paediatric Life Support. A statement from Paediatric Life Support Working Group and approved by the Executive Committee of the European Resuscitation Council

The European Resuscitation Council (ERC) last issued guidelines for Paediatric Life Support (PLS) in 1998 [1]. These were based on the "Advisory Statements" of the International Liaison Committee on Resuscitation (ILCOR) published in 1997 [2]. Following this, the American Heart Association, together with representatives from ILCOR, undertook a series of evidence-based evaluations of the science of resuscitation which culminated in the publication of "Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" in August 2000 [3,4]. The Paediatric Life Support Working Party of the European Resuscitation Council has considered this document and the supporting scientific literature and has recommended changes to the ERC Advanced PLS guidelines. These are presented in this paper. There have been few major changes to the ERC recommended guidelines as some of the changes agreed in "Guidelines 2000" had already been introduced into Europe subsequent to the 1998 ILCOR "Advisory Statements" (Fig. 1).

Silicosis and tuberculosis: a proposed radiographic classification of tuberculosis to accompany the ILO international classification of radiographs of pneumoconioses

A significant proportion of workers exposed to silica dust are at risk of developing tuberculosis (TB). The higher the International Labor Organization (ILO) category of silicosis, the greater the TB risk. Subtle radiographic presentations of TB may be the initial manifestation of TB, particularly in the absence of sputum identification of TB bacilli. A proposed TB x-ray-reading form in addition to the ILO categorization of silicosis is offered. The implementation of a standardized TB x-ray-reading approach should alert the clinician to indolent TB lesions.

Documentation practices of nurses in long-term care

Documentation of nursing care is an important source of reference and communication between nurses and other health care providers. This article describes a study of the documentation practices of nurses in a long-term care institution. Results revealed a number of positive aspects of nurses' documentation practices and areas requiring modification or change which could be facilitated through redesigning the documentation system. Implications for professional practice are discussed, which include the need for a concise, non-duplicating system of documentation, and the importance of nursing documentation in support of evidence-based practice.

Voluntary total fasting in political prisoners--clinical and biochemical observations

Thirty-three political prisoners on hunger strike (voluntary total fast--VTF) for 6-24 days were admitted to two hospitals in Johannesburg in 1989. They had been detained without trial for 4-32 months. Sound doctor-patient relationships were established by emphasis of the principle of full patient participation in clinical decision-making at every level, by rejection of police interference in patient care, and by refusal to discharge subjects back into detention. Depression and abdominal pains were the predominant symptoms. In 6 lean subjects with complete data the expected initial period of rapid weight loss was not observed. Before hospitalisation most subjects became dehydrated from inadequate fluid intake and an apparent absence of thirst. Serum creatinine concentrations were a better indication of dehydration than serum urea levels. Mild hyponatraemia was found in one-third of patients. Refeeding after 6-27 days of VTF was initiated with a dilute lactose-free formula diet, and was uncomplicated. Close clinical monitoring of subjects during VTF is essential, and it is recommended that prisoners should be admitted to hospital at 10% of weight loss, if not before. The health care of prisoners can best be provided by professionals independent of the police and prison services.

Comparative activities of rabbit complements of different ages using an in-vitro marrow purging model

In order to determine the best time to obtain complement for use in marrow purging in vitro, we have used 51Cr-release and limiting dilution assays (LDA) to evaluate the ability of serum from rabbits 20-30 (25d), 30-40 (35d) and 40-50 (45d) days old to lyse a series of neoplastic target cells in the presence of complement activating antibodies. Utilizing a limiting dilution assay (LDA) to measure log depletion of tumor cells in a 20-fold excess of normal bone marrow, treatment with monoclonal antibody and 25d complement depleted at least 4 logs of leukemia or lymphoma cells. 35d and 45d complements were approximately one log less effective. When normal bone marrow alone was treated with either J5 (CD10) antibody alone, each complement alone or a combination of J5 antibody with each complement, there was no significant depletion of hematopoietic progenitors in any subgroup. These results suggest that complement from 20-30 day old rabbits should be used for the purpose of ex-vivo purging due to its highly sensitive and specific activity.