Basic Science Considerations in Primary Total Hip Replacement Arthroplasty

Total Hip Replacement is one of the most common operations performed in the developed world today. An increasingly ageing population means that the numbers of people undergoing this operation is set to rise. There are a numerous number of prosthesis on the market and it is often difficult to choose between them. It is therefore necessary to have a good understanding of the basic scientific principles in Total Hip Replacement and the evidence base underpinning them. This paper reviews the relevant anatomical and biomechanical principles in THA. It goes on to elaborate on the structural properties of materials used in modern implants and looks at the evidence base for different types of fixation including cemented and uncemented components. Modern bearing surfaces are discussed in addition to the scientific basis of various surface engineering modifications in THA prostheses. The basic science considerations in component alignment and abductor tension are also discussed. A brief discussion on modular and custom designs of THR is also included. This article reviews basic science concepts and the rationale underpinning the use of the femoral and acetabular component in total hip replacement

Pain perception in schizophrenia: influence of neuropeptides, cognitive disorders, and negative symptoms

Małgorzata Urban-Kowalczyk,1 Justyna Pigońska,2 Janusz Śmigielski3 1Department of Affective and Psychotic Disorders, Medical University of Łódź, Łódź, Poland; 2Department of Neurology and Movement Disorders, Medical University of Łódź, Łódź, Poland; 3Department of Geriatrics, Healthy Ageing Research Centre (HARC), Medical University of Łódź, Łódź, Poland Objectives: The causes and nature of insensitivity to pain in schizophrenia remain unknown. The role of endorphins and the association of cognitive dysfunction and negative symptoms are postulated.Methods: In this study, 43 patients with schizophrenia, five first-degree relatives, and 34 healthy controls were examined. Participants’ plasma concentrations of substance P, β-endorphin, and calcitonin gene-related peptide (CGRP) were assessed. In patients, the Trail-Making Test, the Color Reading Interference Test (Stroop test), and the Positive and Negative Syndrome Scale Negative Syndrome subscale (PANSS N) test were performed. We also evaluated pain threshold using nociceptive reflex (RTIII) testing.Results: The mean β-endorphin concentration was about 20% higher in patients than in healthy controls (P<0.05). CGRP concentrations were significantly higher in patients than in controls (5.34 ng/mL versus 4.16 ng/mL; P<0.01). Subjects treated with antipsychotic polytherapy had higher concentrations of CGRP than did patients treated with second-generation antipsychotic monotherapy (5.92 ng/mL versus 5.02 ng/mL; P<0.05). There were no correlations between any biochemical parameters and Trail-Making Test, Stroop test, and PANSS N scores. There were no differences in RTIII among study groups. Strong negative correlation (P<0.001) was found between PANSS N scores and subjective pain threshold on the right lower limb.Conclusion: The insensitivity to pain in schizophrenia is a complex phenomenon that is probably not related to changes in nociceptive pathways. Increase in β-endorphin level may be related to this issue, but it is uncertain if such concentration ensures analgesic effect. It is unknown if patients with schizophrenia in fact experience less pain. Cognitive impairment and excess negative symptoms may strongly influence the patient’s expression of pain. Keywords: schizophrenia, endorphin, substance P, calcitonin gene-related peptide, working memory, negative symptom

Comparison of beta-endorphin and CGRP levels before and after treatment for severe schizophrenia

Małgorzata Urban-Kowalczyk,1 Janusz Śmigielski,2 Dominik Strzelecki1 1Department of Affective and Psychotic Disorders, 2Department of Geriatrics, Healthy Aging Research Centre (HARC), Medical University of Lodz, Lodz, Poland Objectives: Links between endorphins and dopaminergic transmission have not been fully explored in schizophrenia. Both endorphins excess and deficiency were postulated. CGRP is probably involved in dopaminergic transmission. The aim of this study was the evaluation of beta-endorphin (BE) and CGRP blood concentrations before and after treatment of severe schizophrenia. Methods: Seventy patients treated with various antipsychotics, with severe symptoms of schizophrenia (51 with positive symptoms, 19 with negative symptoms), 15 first-degree relatives, and 44 healthy controls were included in the study. BE and CGRP blood concentrations were measured during patients severe schizophrenia and in their stable mental state after treatment. The results were compared with relatives and controls. Results: BE and CGRP concentrations in patients with negative symptoms were higher than in relatives and in controls. BE levels in patients with positive symptoms were lower than in patients with negative symptoms (P<0.0000) and controls (P<0.0006). No significant changes in CGRP concentration were found in patient samples. CGRP levels in these samples were independent of treatment, but they were significantly higher than in relatives and controls. After the treatment, BE level decreased in patients with negative symptoms (P<0.0001) and increased in patients with positive symptoms (P<0.0000). No differences in BE concentration between patients in stable mental state, their relatives, and controls were found. Conclusion: Effective antipsychotic treatment results in “normalization” of BE level. Specific changes in BE concentration could be involved in dopaminergic transmission and related to some symptoms of schizophrenia. Keywords: schizophrenia, negative symptoms, neuroleptics, β-endorphin, CGR

Odor perception and hedonics in chronic schizophrenia and in first episode psychosis

Małgorzata Urban-Kowalczyk,1 Dominik Strzelecki,1 Janusz Śmigielski,2 Magdalena Kotlicka–Antczak1 1Department of Affective and Psychotic Disorders, Medical University of Łódź, Łódź, Poland; 2State Higher Vocational School in Konin, Konin, Poland Background and purpose: The study evaluated olfactory performance and pleasantness rating of odors in patients with first episode psychosis (FEP) and chronic schizophrenia (SCH) with regard to the severity of psychopathological symptoms and plasma β-endorphin concentration.Patients and methods: Twenty patients with FEP, 27 with SCH and 29 healthy individuals, were recruited to the research . The University of Pennsylvania Smell Identification Test (UPSIT), subjective odor hedonic judgment and plasma levels of β-endorphin (BE) assay were performed in all participants. Results: Individuals with SCH revealed higher BE concentration than other study groups (P=0.000). All patients identified pleasant odors poorer than controls, however, SCH made more identification errors (P=0.000) than those with FEP. Moreover, participants with FEP rated pleasant odors as more pleasant than individuals with chronic schizophrenia and healthy controls (P=0.009). Nevertheless, higher β-endorphin level was related with lower scores in pleasant odor identification (Rs=–0.452; P=0.046) and more severe psychotic symptoms in FEP sample. Chronic schizophrenia patients did not demonstrate any relationship between symptom severity, odor identification performance and β-endorphin concentration. No relationship was found between BE concentration and hedonic judgment of the presented odors among all study groups. Chronically ill subjects identified odors significantly more poorly than those with first episode psychosis. Deficits in identifying pleasant odors might not be the only potential risk factor for undergoing chronic, recurrent schizophrenia. All patients subjectively overrated pleasant odors. Those with SCH and more severe negative symptoms made significantly more identification errors. Conclusion: The endogenous morphine system deregulation is observed in first episode psychosis as well as in chronic schizophrenia. In first episode schizophrenia higher beta-endorphin concentration is related to pleasant odor identification deficit. Keywords: olfaction, negative symptoms, endogenous opioids, schizophreni

Large-scale mitogenomic analysis of the phylogeography of the Late Pleistocene cave bear

The cave bear (Ursus spelaeus) is one of the Late Pleistocene megafauna species that faced extinction at the end of the last ice age. Although it is represented by one of the largest fossil records in Europe and has been subject to several interdisciplinary studies including palaeogenetic research, its fate remains highly controversial. Here, we used a combination of hybridisation capture and next generation sequencing to reconstruct 59 new complete cave bear mitochondrial genomes (mtDNA) from 14 sites in Western, Central and Eastern Europe. In a Bayesian phylogenetic analysis, we compared them to 64 published cave bear mtDNA sequences to reconstruct the population dynamics and phylogeography during the Late Pleistocene. We found five major mitochondrial DNA lineages resulting in a noticeably more complex biogeography of the European lineages during the last 50,000 years than previously assumed. Furthermore, our calculated effective female population sizes suggest a drastic cave bear population decline starting around 40,000 years ago at the onset of the Aurignacian, coinciding with the spread of anatomically modern humans in Europe. Thus, our study supports a potential significant human role in the general extinction and local extirpation of the European cave bear and illuminates the fate of this megafauna species