Dopaminergic neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the mouse: an in vivo electrochemical study

The long-term (i.e., 4-5 months) effects of large doses (3 X 50 mg/kg) of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on striatal dopamine-containing afferents were studied in the NMRI strain of mice. Recently improved in vivo electrochemical methods were first used to examine the magnitude, spatial distribution and temporal dynamics of monoamine release initiated via local application of potassium in various regions of the mouse striatum. Immunohistochemical localization of tyrosine hydroxylase and computer-based image analysis were also used to quantitate regional catecholamine-containing nerve fiber densities in the caudate nucleus. The in vivo electrochemical studies showed a statistically significant decrease in the average potassium-evoked release of electroactive species from the MPTP-treated mouse caudate nucleus vs. control. Greater decreases in release were seen in dorsal than in ventral striatum (55% vs. 33%). The average rise time of potassium-evoked release was also significantly prolonged (greater than 50%) after MPTP pretreatment. Histochemical studies showed an overall reduction in the density of dopamine-containing terminals in the drug-treated mice, with a greater loss observed in the more dorsal regions of the caudate nucleus. The experimental data thus support a long-term selective destruction of dorsal vs. ventral dopamine-containing afferents to the striatum by the neurotoxin MPTP in mice.     

Isokinetic plantar flexion endurance. Reliability and validity of output/excitation measurements

The reliability and validity of isokinetic measurement of plantar flexion endurance has been studied by a method previously described by us which utilizes simultaneous measurements of mechanical contractional work (CW) and integrated electromyogram (iEMG). The reliability was gauged by test/re-test with a two year's interval; while validity was assessed by myoelectric power spectrum analyses. The output/input balance (CW/iEMG) remained unchanged for the group as well as inter-individually. Changes in myoelectric power spectrum as function of number of contractions were clearly indicative of fatigue. Under the present conditions fatigue of fast twitch motor units may explain the rapid decreases in output and excitation followed by nearly steady state levels of all registered parameters. As is the case for non-fatigued isokinetic plantar flexions, the motor unit recruitment order appears quite stereotyped during plantar flexion fatigue. The findings of significantly lower mean power spectrum during the first part of each contraction than during the second part may support the size-principle described by Henneman.     

Docetaxel Versus Surveillance After Radical Prostatectomy for High-risk Prostate Cancer: Results from the Prospective Randomised,Open-label Phase 3 Scandinavian Prostate Cancer Group 12 Trial

Background

Adjuvant chemotherapy is standard treatment for other solid tumours, but to date has not proven effective in prostate cancer.

Colorectal Cancer Cells Adhere to Traumatized Peritoneal Tissue in Clusters,An Experimental Study

Purpose/Aim: Colorectal malignity is one of the most common forms of cancer. The finding of free intraperitoneal colorectal cancer cells during surgery has been shown to be associated with poor outcome. The aim of this study was to develop an experimental model designed to investigate adhesion of colorectal cancer cells to the peritoneal surface. Materials and methods: Two human experimental models were developed, the first using cultured mesothelial cells and the second consisting of an ex vivo model of peritoneal tissue. Both models were subjected to standardized trauma, following which labeled colorectal cancer cells (Colo205) were introduced. Adhesion of tumor cells was monitored using microscopy and detection of fluorochromes. Results: The mesothelial cell layers and peritoneal membranes remained viable in culture medium for several weeks. In our experimental model, the tumor cells added were seen to adhere to the edges of the traumatized area in cluster formations. Conclusions: The use of human peritoneal tissue in an ex vivo model would appear to be a potentially useful tool for the study of interaction between human peritoneal membrane and free tumor cells. Experimental surgical trauma increases the ability of tumor cells to adhere to the peritoneal membrane. This ex vivo model should be useful in future studies on biological interactions between peritoneum and tumor cells in the search for novel forms of peritoneal cancer therapy.     

The meaning of traumatic events as described by nurses in ambulance service

Ambulance personnel are working with the injured and dead and are therefore exposed to a variety of stressors that can lead to the development of physical, psychological and social reactions. Stress among ambulance personnel can be regarded as a natural behaviour and reaction when experiencing a traumatic event. The aim of this phenomenological study is to uncover the essence of traumatic events experienced by Swedish ambulance personnel. Knowledge about such events contributes to the awareness of risk for post-traumatic stress symptom and serves as a platform for developing measures to handle such stress. In this study, written stories from 52 of 223 ambulance nurses and ambulance technicians describing an experienced traumatic event, are analysed by the method of van Kaam. Findings indicate that the nurses and technicians have a strong identification with the victims and it is impossible to prepare for events that are unforeseen and meaningless. To handle the overwhelming feelings of identification, the personnel have to gain understanding through talking about those feelings. Therefore it is important that ambulance management, following stressful events, provide the opportunity and time for ambulance personnel to share their feelings. Teaching ways of decreasing identification and emotional involvement with the victim may also be an effective preventive measure.     

Fetal hemolytic anemia and intrauterine death caused by anti-M immunization

BACKGROUND: Antibodies with anti-M specificity are detected in 10 percent of pregnant women with a positive antibody screen, but anti-M is only rarely associated with hemolytic anemia in the fetus. STUDY DESIGN AND METHODS: This study reports on three pregnancies in one family that all resulted in severe fetal anemia. The first fetus died in utero with hydrops fetalis during the 20th gestational week and the second child was delivered after 28 weeks of gestation with hydrops fetalis and a hemoglobin level of 16 g per L whereas the third affected child was treated with intrauterine red cell (RBC) transfusions before delivery at 28 weeks of gestation. RESULTS: The direct antiglobulin test was negative but anti-M in a low titer was detected through the three pregnancies, and its clinical relevance, which initially was uncertain, was confirmed by pronounced in vivo hemolysis in maternal blood of chromate ((51)Cr)-labeled M+ RBCs and normal survival of (51)Cr labeled M- RBCs. CONCLUSION: It is concluded that anti-M immunization in a few cases may cause severe fetal hemolytic anemia and intrauterine death. It remains to be elucidated why a normally clinically insignificant antibody is this aggressive in a small proportion of cases. Because the condition is treatable, anti-M must be considered as a possible cause of fetal anemia and intrauterine death.     

Lateral flow immunoassay using Europium (III) chelate microparticles and time-resolved fluorescence for eosinophils and neutrophils in whole blood

BACKGROUND: A simple point-of-care method for measuring leukocyte counts in a doctor's office or emergency room could be of great importance. We developed a protocol for measuring cell count by disrupting the cell membrane and analyzing specific proteins within the cells and used it to analyze proteins from eosinophils and neutrophils. METHODS: Lateral immunochromatographic (ICR) assays have been developed for eosinophil protein X (EPX) and human neutrophil lipocalin (HNL) as measures of the concentration of eosinophils and neutrophils. The correlation between the lateral ICR assays and cell counting of eosinophils and neutrophils was performed manually and with an automated cell counter. RIA assays measuring the same analytes were also compared with the results from cell counting and lateral ICR assays. RESULTS: The optimized assays showed analytical detection limits below the clinical ranges of 3.36 microg/L and 2.05 microg/L for EPX and HNL, respectively. The recovery was 114.8%-122.8% for EPX and 94.5%-96.9% for HNL. The imprecision was 3%-17% CV for EPX over the whole range and 5%-16% CV for HNL. The correlation coefficients between manually counted cells and lateral ICR assays were 0.9 and 0.83 for EPX and HNL, respectively. CONCLUSION: The numbers of eosinophils and neutrophils in small amounts of blood can be estimated in the point-of-care setting by means of fast lateral ICR assays of EPX and HNL.     

Bacterial contamination of the wound during primary total hip and knee replacement: Median 13 years of follow-up of 90 replacements

Background and purpose

Previous work has shown that despite preventive measures, intraoperative contamination of joint replacements is still common, although most of these patients seem to do well in follow-up of up to 5 years. We analyzed the prevalence and bacteriology of intraoperative contamination of primary joint replacement and assessed whether its presence is related to periprosthetic joint infection (PJI) on long-term follow-up.

Patients and methods

49 primary total hip replacements (THRs) and 41 total knee replacements (TKRs) performed between 1990 and 1991 were included in the study. 4 bacterial swabs were collected intraoperatively during each procedure. Patients were followed up for joint-related complications until March 2011.

Results

19 of 49 THRs and 22 of 41 TKRs had at least 1 positive culture. Coagulase-negative staphylococci and Staphylococcus aureus were the most common organisms, contaminating 28 and 9 operations respectively. Where information was available, bacteria from 27 of 29 contaminated operations were susceptible to the prophylactic antibiotic administered. 13% of samples gathered before 130 min of surgery were contaminated, as compared to 35% collected after that time. 2 infections were diagnosed, both in TKRs. 1 of them may have been related to intraoperative contamination.

Interpretation

Intraoperative contamination was common but few infections occurred, possibly due to the effect of prophylactic antibiotics. The rate of contamination was higher with longer duration of surgery. It appears that positive results from intraoperative swabs do not predict the occurrence of PJI.Periprosthetic joint infection (PJI) is a major complication of joint replacement. 1 year after primary total joint replacement, around 1% of patients have been revised due to deep infection; superficial surgical site infections (SSIs) are more common and occur in around 3% of cases (Jämsen et al. 2010, Dale et al. 2011). PJI is difficult to diagnose and treat and has a severe effect on quality of life (Whitehouse et al. 2002). The number of primary joint replacements will increase (Kurtz et al. 2007), so the incidence of PJI may also rise. Prevention is of key importance. Measures such as laminar air flow and prophylactic antibiotics are effective (Lidwell et al. 1987). Intraoperative contamination is, however, common—occurring in one-fifth to two-thirds of operations. However, the short-term prognosis of most of these patients appears to be good (Davis et al. 1999, Byrne et al. 2007). Intraoperative contamination is usually the cause of early infections, but it may also cause a substantial number of the infections arising more than 2 years after surgery (Phillips et al. 2006). To our knowledge, there have been no studies on intraoperative contamination with over 5 years of follow-up.We studied the prevalence and bacteriology of intraoperative contamination during primary joint replacement and assessed whether the presence of intraoperative contamination is related to PJI on long-term follow-up.     

Epidemiology of fractures in Iceland and secular trends in major osteoporotic fractures 1989–2008

Summary

The incidence of the most common fracture types in Iceland is reported based on individual data from the Reykjavik Study 1967–2008. Time trend is reported for the major osteoporotic fractures (MOS) 1989–2008.

Introduction

This study aims to assess the incidence of all fractures in Iceland, with emphasis on the rate of hip fractures, and compare the incidence with other populations as well as examine the secular changes.

Methods

Individuals from the prospective population-based cohort Reykjavik Study were examined between 1967 and 2008 (follow-up 26.5 years), which consisted of 9,116 men and 9,756 women born in 1907–1935, with age range 31–81 years. First fracture incidence was estimated using life table methods with age as the timescale.

Results

Fracture rate increased proportionally with age between the sexes for vertebral and proximal humerus but disproportionally for hip and distal forearm fractures. The ratio of first fracture incidence between the sexes varied considerably by site: 2.65 for hip fractures and the highest for distal forearm fractures at 4.83. By the age of 75, 36.7 % of women and 21 % of men had sustained a fracture, taking into account competing risk of death. The incidence of hip fractures was similar to results previously published from USA, Sweden, Norway, and Scotland. The incidence of MOS fractures in both sexes decreased over the last decade, except hip fractures in men, which remained unchanged, as reflected in the women/men ratio for the hip, which changed from 2.6 to 1.7.

Conclusion

This study adds information to scarce knowledge on the relative fracture incidence of different fractures. The incidence of MOS fractures increased in the latter part of the last century in both sexes and declined during the last decade, less dramatically for men. This information is important for planning health resources.