Preload and friction in an implant-abutment-screw complex including a carbon-coated titanium alloy abutment screw: an in vitro study.

PURPOSE: An experimental approach was designed to measure the preload force, the coefficient of friction and the component of the tightening torque that is needed to surmount the thread-friction in an implant-abutment-screw complex that includes a carbon-coated screw. With the determined preload values the coefficient of friction was calculated. METHODS: 25 unused complexes, containing an implant, an abutment and a carbon-coated titanium alloy abutment screw, were tested. A custom load frame with two load cells and associated electronics was used. The threads were not lubricated. All abutment screws were torqued ten times to 25 Ncm. The produced preload values and a force that was proportional to the thread-friction component of the tightening torque were recorded. RESULTS: Mean preload values decreased significantly with the number of repetitions (p < 0.0001) from initially 329.9 N ± 33.3 (range 255.7 to 383.9) to 253.7 N ± 36.8 (range 200.1 to 332.5) for the last tightening procedure. The corresponding change in the calculated coefficient of friction was 0.33 ± 0.04 (range 0.28 to 0.43) to 0.44 ± 0.07 (range 0.32 to 0.56). For the thread-friction no corresponding trend for consecutive tightening repetitions could be noticed. CONCLUSIONS: In the investigated implant-abutment units, repeated use of a coated abutment screw appears to increase the friction of the screw head and thereby decrease the preload. These results indicate that a pre-used coated implant-abutment-screw will fail reaching optimal screw preload.

Peripheral venous or tibial intraosseous access for medical emergency treatment in the dental office?

BACKGROUND: The anterior tibia has been recommended as emergency vascular access site if the intravenous route cannot be used. OBJECTIVE: This study aims to evaluate the peripheral venous and anterior tibial intraosseous puncture as alternatives for dentists, using a human and a cadaver model.Method One group of dental students performed a venipuncture by using a standard catheter device (n = 21) on other students. Another group (n = 24) used the Vidacare EZ-IO intraosseous kit on a cadaver tibia with india ink as a tracer. Success rates as well as the time needed for a successful puncture were recorded. RESULTS: 28.5% of venous and 83.3% of intraosseous punctures were successful. The relative risk of venous cannulation failure was 3.4 (95% CI 1.6-7.2; p = 0.0005). A successful venous access could be performed within 163 ± 23.2 seconds (mean ± SD), a tibial intraosseous access within 30 ± 27.8 seconds (p = 0.0003). CONCLUSIONS: Within the limitation of this study, it can be demonstrated that the chances to perform a successful vascular access for inexperienced dentists may be higher when using the tibial intraosseous route for emergency intravascular medication.

An Assessment of HIV-Infected Patients Dying in Care for Deceased Organ Donation in a United States Urban Center.

Organ transplantation is an acceptable option for human immunodeficiency virus (HIV)-infected patients with end-stage kidney or liver disease. With worse outcomes on the waitlist, HIV-infected patients may actually be disproportionately affected by the organ shortage in the United States. One potential solution is the use of HIV-infected deceased donors (HIVDD), recently legalized by the HIV Organ Policy Equity (HOPE) Act. This is the first analysis of patient-specific data from potential HIVDD, retrospectively examining charts of HIV-infected patients dying in care at six HIV clinics in Philadelphia, Pennsylvania from January 1, 2009 to June 30, 2014. Our data suggest that there are four to five potential HIVDD dying in Philadelphia annually who might yield two to three kidneys and three to five livers for transplant. Extrapolated nationally, this would approximate 356 potential HIVDD yielding 192 kidneys and 247 livers annually. However, several donor risk indices raise concerns about the quality of kidneys that could be recovered from HIVDD as a result of older donor age and comorbidities. On the other hand, livers from these potential HIVDD are of similar quality to HIV-negative donors dying locally, although there is a high prevalence of positive hepatitis C antibody.

Severe vitamin C deficiency in a critically ill adult: a case report.

Scurvy, a severe form of vitamin C deficiency, killed scores of people until its cause and treatment were firmly established at the end of the eighteenth century. Since then, cases have surged periodically around the world, mostly in developing countries and during times of war and famine. In developed countries, scurvy is still endemic and evidence is growing that vitamin C deficiency might affect up to 30 percent of the population. Low socio-economic status, alcoholism, severe psychiatric illness leading to poor nutrition and critical illness are significant risk factors. We hereby report the case of a patient admitted in a Swiss intensive care unit of a tertiary teaching hospital and presenting with clinical signs and symptoms of severe vitamin C deficiency.

Anatomical Position of Four Different Transobturator Mesh Implants for Female Anterior Prolapse Repair.

Purpose: Polypropylene mesh implants are frequently used for pelvic floor reconstruction in women. Yet they vary in size and fixation. The purpose of this study is to compare four mesh products with regard to their anatomical positioning and functionality within the pelvic floor, to determine whether each mesh fits equally well in a female cadaver. Methods: One female pelvis was dissected, opening the retropubic space exposing the endopelvic fascia and demonstrating the arcus tendineus fasciae pelvis (ATFP). Anatomical parameters were measured before and after implanting four meshes via the transobturator approach. Results: The anterior fixation of the ATFP was found to be 5 mm lateral to the symphysis in this cadaver. The endopelvic fascia covered 54.6 cm2. The obturator nerve was located 35 mm from the white line. The distance of the proximal and lateral points of mesh fixation from the ischial spine or ATFP varied from 0 to 25 mm. The meshes varied in size and anatomical positioning. Conclusion: These observations demonstrate the necessity of developing optimally sized meshes and appropriate introducer techniques that can provide sufficient vaginal support. Surgeons, furthermore, need profound knowledge of anatomy, the patient's pelvic floor defect and the meshes available on the market.

Effects of conjugated linoleic acids fed to dairy cows during early gestation on hematological, immunological, and metabolic characteristics of cows and their calves.

The aim of the present experiment was to test the stimulation ability of peripheral blood mononuclear cells (PBMC) expressed as stimulation index (SI) of newborn calves and of their dams fed a control fat supplement (CON, n=6) or 50 and 100g/d of a CLA-containing fat supplement (CLA50, n=5, and CLA100, n=6, respectively) during the preceding lactation period for 182 d after calving. The total intake of cis-9,trans-11 and trans-10,cis-12 CLA by groups CLA50 and CLA100 amounted to 4 and 8 g/d each, respectively. For this purpose, blood was collected immediately after parturition from calves before and after colostrum intake, and from cows after parturition and 21 d later. The SI was related to the fatty acid composition of erythrocyte and milk lipids and to various hematological and clinical-chemical parameters. Retrospective evaluation revealed that depletion time (i.e., the individual period elapsed between the day of terminating the feeding of the experimental diet in the preceding lactation period and the day of calving) ranged from 190 to 262 d, which corresponded to fetal exposure times of 19 to 102 d. The SI from cows increased significantly by 77 and 55%, within 21 d after calving according to the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) and Alamar Blue assays, respectively. However, feeding of 50 g of the CLA product failed to demonstrate this increase in the MTT assay. Moreover, SI was significantly lower for calves whose dams belonged to the CLA50 group, whereas stimulation ability was comparable for the PBMC from calves whose mothers were treated with CON and CLA100. Plasma metabolites (total bilirubin, total cholesterol, glucose, nonesterified fatty acids, 3-ß-hydroxybutyrate, total protein, and albumin) and hematological parameters (hematocrit, white blood cell profile) were not significantly influenced by dietary treatments of the cows in the preceding lactation period. Although the fatty acid pattern of erythrocyte lipids of cows remained uninfluenced, that of calves showed alterations due to the feeding type of their dams. For example, C16:0 increased significantly from 14.4 to 16.9% of total fatty acid methyl esters, whereas cis-9,trans-11 CLA increased slightly from 0.11 to 0.15% at the same time in calves when their mothers were fed the CLA100 instead of the CON diet. Fatty acid profile of colostrum was significantly different from that of milk after 3 wk for most of the detected fatty acids, but was not influenced by diet type. In conclusion, feeding a CLA-containing fat supplement during the preceding lactation and gestation period exerted effects on the stimulation ability of PBMC from cows and calves for the subsequent parturition. However, CLA dose effects were inconsistent and require further investigation.

[End of life care in intensive care units]. / Accompagnement de fin de vie aux soins intensifs.

In intensive care units, death occurs after a medical decision of treatment limitation in a great majority of patients. In this context, taking care of the patient and his relatives is ethically, practically and emotionally complex. End of life is a well known factor of conflict, burnout and stress among medical and nursing teams in the ICU. The recommendations described in the following article are expected to clarify the roles and practices of the professionals involved in end of life procedures in the ICU.

Recombinant hirudin for cardiopulmonary bypass anticoagulation: a randomized, prospective, and heparin-controlled pilot study.

BACKGROUND: Lepirudin, a recombinant hirudin, is a direct acting thrombin inhibitor that has been used as a heparin alternative in patients with heparin-induced thrombocytopenia requiring on-pump cardiac surgery. To evaluate the efficacy, safety, and clinical utility of lepirudin as a cardiopulmonary bypass (CPB) anticoagulant, we compared lepirudin with heparin in a routine CPB setting. METHODS: Twenty patients were randomly assigned to receive lepirudin (0.25 mg/kg b. w. bolus and 0.2 mg/kg b. w. added to the CPB priming) or heparin (400 U/kg b. w. bolus) with protamine reversal. Lepirudin and heparin anticoagulation during CPB was monitored using the ecarin clotting time or ACT, respectively and additional lepirudin (5 mg) or heparin (5000 U) boluses were administered. RESULTS: The CPB circuit was performed in both groups without thromboembolic complications. Median blood loss during the first 36 hours was statistically higher ( P = 0.007) in the lepirudin group (1.226 +/- 316 ml) compared to the heparin group (869 +/- 189 ml). One patient of the lepirudin group developed pulmonary embolism 24 hours after surgery. This patient was tested homozygous for the FV-Leiden mutation. CONCLUSION: Lepirudin provides effective CPB anticoagulation but induces a higher postoperative blood loss than heparin. Lepirudin should be restricted to patients undergoing CPB who cannot be exposed to heparin.

Effects of the Fusarium toxin deoxynivalenol on tissue protein synthesis in pigs.

The Fusarium toxin deoxynivalenol is known to be a potent protein synthesis inhibitor according to research in different in vitro and in vivo systems. However, the significance of this toxic feature was not yet evaluated for the pig. Therefore, an experiment was carried out to measure porcine tissue protein synthesis employing the so-called flooding dose technique using [(2)H(5)]-phenylalanine as tracer. A total of 25 male castrated pigs (initial weight of 23kg) were used. Seventeen pigs were fed the control diet (control) and eight the Fusarium toxin-contaminated diet (chronic oral deoxynivalenol (DON)) for approximately 4wks. Pigs recruited from the control group were treated with acute oral (n=7) and intravenous (i.v.) DON (n=5), and were exposed to the toxin once on the day of protein synthesis measurement. The DON-dose given prior to the beginning of protein synthesis measurement amounted to 2, 77, 83 and 53microg DONkg(-1) live weight for the control group, chronic oral DON-group, acute oral DON-group and acute i.v. DON-group, respectively. Protein synthesis expressed as fractional synthesis rate (FSR) was significantly reduced in kidneys, spleen and ileum of DON-exposed pigs with effects being less pronounced in the acute oral DON-group. FSR of liver, skeletal and heart muscle, mesenteric lymph nodes, duodenum, jejunum, jejunal mucosa cells, pancreas and lung were not affected by DON.

Research note: Effects of deoxynivalenol on immunohistological parameters in pigs.

TheFusarium toxin deoxynivalenol (DON) is known to exert immunomodulatory effects. Numerous studies in mice demonstrated that dietary exposure leads to an upregulation of polymeric serum immunoglobulin A (IgA) suggesting the mucosal immune system as a primary target while at the cellular level T cells and macrophages are involved in this process.The present study aimed to verify these effects in pigs. A total of 24 male pigs were subjected to four treatments, a control group fed a diet devoid of DON, a chronically exposed group receiving a diet containing contaminated wheat (5.7 mg DON/kg diet), an acute orally exposed group receiving only one meal (550 g) of the contaminated feed and an acute intravenous exposed group receiving 53 µg DON/kg body weight. Cryosections of the spleen and the jejunum of the pigs were immunohistologically stained for IgA+, CD3+, CD4+ and CD8+ cells. The number of positive stained cells did not differ significantly between the treatment groups and the control group of any of the specimen.

The efficacy of a modified aluminosilicate as a detoxifying agent in Fusarium toxin contaminated maize containing diets for piglets.

Two feeding experiments with female weaned piglets were carried out applying a complete two by two factorial design to investigate the effects of the dietary inclusion of 500 g/kg Fusarium toxin contaminated maize (8.6 mg/kg deoxynivalenol (DON); 1.2 mg/kg zearalenone (ZON)) and of 4 g/kg aluminosilicate (AS) as a detoxifying agent. The resulting four diets were fed ad libitum to a total of 80 piglets (20 piglets per group, allotted to a total of 20 pens) covering a live weight range of 10.5 +/- 1.3 to 27.5 +/- 4.4 kg in experiment 1, and to a total of 48 piglets (12 piglets per group, allotted to 12 pens) covering a live weight range of 9.7 +/- 1.8 to 21.4 +/- 4.8 kg in experiment 2. The animals of experiment 1 were slaughtered on days 34-36 of feeding the experimental diets. The mycotoxin analyses revealed that the control maize also contained considerable concentrations of Fusarium toxins, but the differences in DON and ZON concentrations between control and contaminated diets were sufficiently high to demonstrate both dose-related toxin effects. Voluntary feed intake and live weight gain of the animals were significantly reduced by the inclusion of Fusarium toxin contaminated maize into the diets in both experiments, while a significantly decreased feed to gain ratio was found in experiment 1. Furthermore, the relative weight of the uterus, stomach and heart of the animals fed the contaminated maize containing diets were significantly increased. Serum albumin concentrations and the activity of GLDH were significantly reduced by the inclusion of the contaminated maize. The addition of AS to the Fusarium toxin contaminated diets did not prevent or alleviate any of the mentioned effects. Moreover, the feed intake tended to be decreased by this supplementation in both experiments, while a significantly decreased feed to gain ratio was indicated for this factor in experiment one as well. The serum concentration of albumin and the activities of ASAT and gammaGT were significantly increased if AS was present in the diets while serum concentration of cholesterol and alpha-tocopherol were decreased significantly or in tendency, respectively. The concentrations of retinol and retinyl esters in liver and serum were not altered by the treatments. The analysed concentrations of zearalenone (ZON) and its metabolites in the bile fluid clearly indicated the differences in dietary ZON concentrations and showed that AS was ineffective in preventing the absorption of the toxin from the gastrointestinal tract. Also, serum concentrations of DON reflected the DON intake prior to sampling. However, there were no differences between groups fed diets with or without AS which also suggests the inefficacy of the tested AS in preventing the DON absorption. The present investigations failed to demonstrate a detoxifying capacity of the tested additive and emphasize the general necessity for a critical verification of detoxifying agents in vivo.

Functional pathology of the ovaries and uteri of premature female piglets exposed to distinct amounts of zearalenone.

The objective of this study was to investigate the effects of four different concentrations (groups II-V) of orally administered zearalenone (ZON) over a feeding period of 35 days on parts of the genital tract of 75 day-old female piglets in comparison to a control group (I). In order to determine possible dose related characteristics for a ZON intoxication in ovaries and uteri, histomorphological (HE and Azan stained slides) and immunohistochemical methods [expression patterns of estrogen (ER) and progesterone (PR) receptor, proliferating cell nuclear antigen (PCNA)] were carried out. Using these methods, there were no obvious (immuno-) histomorphological differences within the treatment groups or in comparison to the control group. Nevertheless, compared to the group I, statistical analyses of all parameters investigated revealed significance only in the increased mitotic activity of muscle cells in the uterinelamina muscularis in treatment group V.

The effect of increasing concentrations of Fusarium toxins in piglet diets on histological parameters of the uterus and vagina.

The effects of feeding diets containing 0.01, 0.06, 0.15, 0.22 and 0.42 mg zearalenone and 0.2, 0.8, 1.0, 1.9 and 3.9 mg deoxynivalenol per kg, originating from Fusarium toxin contaminated maize, on the uterus of 50 prepubertal piglets (10 pigs per treatment; BW 32.6+/-5.4 kg; approximately 70 days of age) were investigated. The mean weight of the uteri of animals receiving the most highly contaminated diet was significantly increased at the time of slaughtering. The histological investigation showed no marked differences between the feeding groups. Histometrical parameters of the surface epithelium of the uterus, of the uterine glands and the vaginal epithelium were not altered by the treatment.

In vitro studies on the evaluation of mycotoxin detoxifying agents for their efficacy on deoxynivalenol and zearalenone.

A simple in vitro system was developed to study the efficacy of commercially available mycotoxin detoxifying agents and adsorbing substances as feed additives to detoxify deoxynivalenol (DON) and zearalenone (ZON) in situ. The in vitro model simulates the conditions (pH, temperature and transit time) of the porcine gastrointestinal tract, as pigs react most sensitively to these mycotoxins. The commercially available products were not effective in detoxifying DON and ZON under the applied conditions, while activated carbon was able to bind both toxins and cholestyramine, and a modified aluminosilicate showed good adsorption abilities for ZON. Data obtained in dose dependency studies showed an estimated adsorption capacity of cholestyramine and the modified aluminosilicate of 11.7 and 5.7 g ZON/kg detoxifying agent. The in vitro system deployed in the present study was demonstrated to be a simple, helpful tool in screening substances for their ability to detoxify DON and ZON under the simulated conditions of the porcine gastrointestinal tract. Nonetheless in vivo experiments are indispensable to proof the efficacy.

On the toxicokinetics and the metabolism of deoxynivalenol (DON) in the pig.

Eleven castrated male pigs weighing 88.1 +/- 3.9 kg on average were adapted to a diet containing DON (4.2 mg DON/kg) over a period of 7 days. Feed was given restrictively with 1.1 kg per meal (two meals per day). On the day of measurement, all pigs were slaughtered at different time intervals following the morning meal containing DON (1, 2, 3, 4, 5, 6, 8, 15, 18 and 24 h after feeding), with the exception of one pig which was slaughtered unfed. DON and de-epoxy-DON were analysed in serum and digesta from consecutive segments of the digestive tract (stomach, small intestine divided into three parts of a similar length, caecum, colon, rectum). DON was rapidly and nearly completely absorbed while passing through the stomach and the proximal small intestine. Maximum serum concentration appeared 4.1 h after the DON-containing meal and half of the systemically absorbed DON was eliminated after 5.8 h. De-epoxy-DON appeared in increasing proportions from the distal small intestine and reached approximately 80% of the sum of DON plus de-epoxy-DON in faeces collected from the rectum. It was concluded that de-epoxydation of DON, which primarily occurs in the hindgut, probably does not contribute much to a detoxification in the pig.

Effects of graded levels of Fusarium toxin contaminated wheat in diets for fattening pigs on growth performance, nutrient digestibility, deoxynivalenol balance and clinical serum characteristics.

A dose response study was carried out with pigs in order to examine the effects of increasing dietary deoxynivalenol (DON)-concentrations on performance, clinical serum characteristics, nutrient digestibility and DON-metabolism. For this purpose, wheat contaminated naturally with Fusarium toxins was incorporated into pig diets at increasing proportions to give calculated dietary DON-concentrations of 0, 2.3 and 4.6 mg/kg during the starter period of phase 1 (14 d) of the experiment, and 0/0, 1.2/1.4, 2.3/3.7 mg/kg starter/grower diet during phase 3 (56 d) of the experiment. Each diet was tested on 16 pigs of both sexes with an initial average live weight of approximately 28 kg. A recovery phase (phase 2, 21 d) was intercalated between phase 1 and 3 of the growth experiment where all groups were fed with the uncontaminated control diet since some pigs exposed to the highest dietary DON-concentration during phase 1 nearly completely refused the offered feed. Affected pigs completely recovered during this phase. In phase 3, when diets with lower DON-concentrations were fed, no differences in performance could be detected. Serum clinical characteristics (enzymes indicating liver damage, total protein, immunoglobulins) did not respond to increasing DON-concentration in the diets. DON-concentration in serum increased in a dose-response-related manner as dietary DON-concentration increased. However, this parameter was not or only weakly correlated to any of the examined performance parameters or serum characteristics. Also, nutrient digestibility of the diets and N-retention were not affected by treatments with the exception of crude fat digestibility which was not consistently influenced. Concentration of DON and its metabolite de-epoxy-DON increased in urine with increasing dietary DON-concentration in a strongly linearly related fashion. The proportion of the excretion of de-epoxy-DON of the total urinary excretion of DON plus de-epoxy-DON rose linearly up to approximately 4%. Total recovery of DON plus de-epoxy-DON as percentage of DON-intake varied between 45 and 57% and was not influenced by dietary DON-concentration. Only a very small fraction of approximately 0.1% of ingested DON was recovered in faeces.

In vivo detoxification of Fusarium toxins.

Fusarium toxins are of great practical relevance in animal feeding since they may occur in toxicologically relevant concentrations. Therefore, many attempts have been made to find ways to detoxify contaminated feedstuffs or diets in order to cope with the problem. The supplementation of contaminated diets with detoxifying agents seems to be easily feasible, and in vitro results seem to be convincing. According to the Guideline 87/153/EEC of the Council of the European Communities, efficacy has to be proven by using an experimental design justified by the claims for use of the additive. In a review of the literature, only a few studies investigated specific parameters that could clearly reflect the claimed mode of action of the additives, and those demonstrated no measurable detoxifying effects. The majority of investigations focused on rather non-specific performance parameters, while many of these applied incomplete experimental designs. Nevertheless, most of the experiments did not demonstrate preventive effects. It is concluded that testing of currently available detoxifying agents did not follow the Council Directive in style and since the claim for their use was not proven. The application of complete two by two factorial experimental designs, the investigation of mycotoxins and/or metabolites in physiological samples as specific parameters and the verification of the specificity of the detoxifying agent is recommended for future in vivo investigations.

Effects of graded levels of Fusarium toxin contaminated maize in diets for female weaned piglets.

A dose response study was carried out with piglets to examine the effects of increasing amounts of Fusarium toxins in the diet on performance, clinical serum characteristics, organ weights and residues of zearalenone (ZON) and deoxynivalenol (DON) and their metabolites in body fluids and tissues. For this purpose, Fusarium toxin contaminated maize (1.2 mg ZON and 8.6 mg DON per kg maize) was incorporated into a maize based diet for piglets at 0, 6, 12.5, 25 and 50% at the expense of control maize. The experimental diets were tested on 100 female piglets allotted to 20 boxes (five animals per box) covering a body weight range of 12.4 +/- 2.2 kg to 32.5 +/- 5.6 kg. Voluntary feed intake and, consequently, body weight gain of the animals receiving the highest proportion of Fusarium toxin contaminated maize were significantly decreased while the feed conversion ratio was not affected by the treatment. The mean weight of the uterus related to the body weight of the animals of the same group was increased by almost 100% as compared to the control. For this group, significantly decreased values of total serum protein were determined, while the serum activity of the liver enzyme glutamate dehydrogenase and the serum concentration of the follicle stimulating hormone were decreased for all treatment groups receiving 6% contaminated maize or more in the diet. Serum concentrations of immuneglobulins were not consistently altered by the treatment. Corresponding to the dietary exposure, increasing concentrations of ZON and alpha-zearalenol were detected in the bile fluid, liver and in pooled urine samples. The metabolite beta-zearalenol was detected only in bile fluid. The total concentration of ZON plus its metabolites in bile fluid correlated well with the diet contamination (r = 0.844). DON was found in serum, bile fluid and pooled urine samples while de-epoxy-DON was detected only in urine. The serum concentration of DON correlated well with the respective toxin intake 3-4 h prior to slaughtering (r = 0.957). For all mentioned analyses of residues it has to be noted that toxin residues were detectable even if negligible concentrations were present in the diet.