Analysis of the position of the branches of the ulnar nerve in Guyon’s canal using high-resolution MRI in positions adopted by cyclists

Purpose

To study variations in the anatomical relationships of the branches of the ulnar nerve in Guyon’s canal relative to the hamulus of hamate (HH) in a grip encountered among cyclists.

Materials and methods

Forty-seven wrist examinations were performed on a 3-T MRI (soft antenna, 16 channels) in propeller sequence in the plane perpendicular to the carpus in 28 healthy volunteers in three cycling positions (neutral, hyperextension and ulnar deviation). The positions and distance between the superficial (SB) and deep (DB) branches of the ulnar nerve with respect to the HH were determined on the section passing through the HH.

Results

The mean distances between the SB (d _s) and DP (d _p) and HH were 2.4 and 0.6 mm, respectively. The d _s in hyperextension and ulnar deviation were 2.2 mm (P = 0.3) and 3 mm (P = 0.07), respectively. The d _p in hyperextension and ulnar deviation were 0.3 mm (P = 0.02) and 0.5 mm (P = 0.15), respectively. Hyperextended, 60 % of SB and 40 % of DB were close to the HH, and 26 % of DB came directly in contact with it. In ulnar deviation, 30 % of SB and 29 % of DB approached HH, and 47 % of DB were in contact with it.

Conclusion

This study shows that SB and DB positions of the ulnar nerve vary with respect to the HH depending on the position of the wrist, and such differences may promote Guyon’s canal syndrome in cyclists.

     

An unusual canal in the apical part of a petrous bone--an emissary canal for the superior petrosus sinus?]

A bone canal was found in the apical part of a Pars petrosa, connecting the Sinus petrosus superior and the "Foramen petrobasilare", which is a Foramen emissarium of the Sinus petrosus inferior. This canal was interpreted as a Canalis emissarius of the Sinus petrosus superior.     

Metoptic canal, duplication of the optic canal and Warwick’s foramen in human orbits

The region of the optic strut is sometimes traversed by some minor canals whose incidence and general characteristics have never been studied. As such canals could be the route for vessels that could interfere in the surgery of the orbital apex, we undertook a detailed anatomical study on a vast collection of dry skulls. The examination of 943 dry adult skulls and 360 foetal skulls was carried out to precise the anatomy of canals in the optic strut area, their development and relationships with the optic canal. A canal traversing the optic strut was present in 8.54 % of the orbits. Based on diameter, position within the optic strut, and thickness of the bony plate separating it from the optic canal or from the superior orbital fissure, the canals piercing the optic strut were classified into four types, which include the well-known duplication of the optic canal, different aspects of the metoptic canal and a type of canal that to our knowledge has never been reported. Warwick’s foramen was found in 0.74 % of orbits. The area of the optic strut is the frequent site of canals joining the orbit with the middle cranial fossa. Some of them can host the ophthalmic artery; others could be run by minor vessels which, however, could be the source of annoying bleedings in surgical procedures.     

The potential role for infections in the pathogenesis of autoimmune Addison’s disease

Autoimmune Addison’s disease (AAD), or primary adrenocortical insufficiency, is a classical organ-specific autoimmune disease with 160 years of history. AAD is remarkably homogeneous with one major dominant self-antigen, the cytochrome P450 21-hydroxylase enzyme, which is targeted by both autoantibodies and autoreactive T cells. Like most autoimmune diseases, AAD is thought to be caused by an unfortunate combination of genetic and environmental factors. While the number of genetic associations with AAD is increasing, almost nothing is known about environmental factors. A major environmental factor commonly proposed for autoimmune diseases, based partly on experimental and clinical data and partly on shared pathways between anti-viral immunity and autoimmunity, is viral infections. However, there are few reports associating viral infections to AAD, and it has proved difficult to establish which immunological processes that could link any viral infection with the initiation or progression of AAD. In this review, we will summarize the current knowledge on the underlying mechanisms of AAD and take a closer look on the potential involvement of viruses.     

Histological examination of the potential arrhythmic substrates in the setting of Ebstein’s malformation

Cardiac arrhythmias, notably Wolff-Parkinson-White syndrome, are known to represent a major issue in patients with Ebstein’s malformation of the tricuspid valve. Abnormal conducting circuits, however, can also be produced by pathways extending either from the atrioventricular node or the ventricular components of the atrioventricular conduction axis, direct to the crest of the muscular ventricular septum. We hoped to provide further information on the potential presence of such pathways by investigations of six autopsied examples of Ebstein’s malformation. All were studied by histological sectioning on the full extent of the atrioventricular conduction axis, with limited sectioning of the right atrioventricular junction supporting the inferior and antero-superior leaflets of the deformed tricuspid valve. We used the criteria established by Aschoff (Verhandlungen der Deutschen Gesellschaft für Pathologie, 14, 1910, 3) and Mönckeberg (Verhandlungen der Deutschen Gesellschaft für Pathologie, 14, 1910, 64) over a century ago to define abnormal connections across the atrioventricular junctions, as these definitions retain their validity for the identification of gross myocardial connections across the insulating tissues of the atrioventricular junctions. In one specimen, we found two discrete accessory myocardial connections across the parietal right atrioventricular junction. In all of the hearts, we found so-called nodoventricular connections, and in one heart we also observed a well-formed connection originating from the penetrating atrioventricular bundle. In addition to accessory myocardial connections across the parietal right atrioventricular junction, therefore, our histological findings demonstrate a potential role for direct connections between the atrioventricular conduction axis and the ventricular myocardium in the setting of Ebstein’s malformation.     

Examining the variation in GPs’ referral practice: a cross-sectional study of GPs’ reasons for referral

Background

There is a large variation in referral rates to secondary care among GPs, which is partly unexplained.

Aim

To explore associations between reasons for referral to secondary care and patient, GP, and healthcare characteristics.

Design and setting

A cross-sectional study in Northern Norway.

Method

Data were derived from 44 (42%) of 104 randomly selected GPs between 2008 and 2010. GPs scored the relevance of nine predefined reasons for 595 referrals from 4350 consecutive consultations on a four-level categorical scale. Associations were examined by multivariable ordered and multivariable multilevel logistic regression analyses.

Results

Medical necessity was assessed as a relevant reason in 93% of the referrals, 43.7% by patient preference, 27.5% to avoid overlooking anything, and 14.6% to reassure the patient. The higher the referral rates, the more frequently the GPs referred to avoid overlooking anything. Female GPs referred to reassure the patient and due to perceived deficient medical knowledge significantly more often than male GPs. However, perceived easy accessibility of specialists was significantly less frequently given as a reason for referral by female GPs compared with male GPs. When the GPs scored the referrals to be of lesser medical necessity, male GPs referred significantly more frequently than female GPs to reassure the patient due to patient preference and perceived deficient medical knowledge.

Conclusion

There are striking differences in reasons for referral between Norwegian male and female GPs and between GPs with high and low referral rates, which reflects difficulties in handling professional uncertainty. Referring to reassure the patients, especially when referrals are less medically necessary, may reflect consideration and acquiescence towards the patients.     

Correction to: Anatomical variation in the form of inter‑ and intra‑individual laterality of the calcaneofibular ligament

Anatomical Science International - A correction to this paper has been published: https://doi.org/10.1007/s12565-021-00617-8     

The Guyon��s canal in perspective: 3-T MRI assessment of the normal anatomy, the anatomical variations and the Guyon��s canal syndrome

Purposes

(1) To revisit the anatomical boundaries of the canal, its contents and its two channels, (2) to describe the anatomical variations of the canal??s borders and the variations of its contents, and (3) to discuss the clinical relevance of the Guyon??s canal syndrome.

Methods

Two hundred and fifty MR wrists examinations were reviewed. MR spin echo T1-weighted axial slices were used to analyze the Guyon??s canal. The anatomical boundaries, the cross-sectional area and length of the canal were calculated. The anatomical variations of the canal??s walls and contents and their prevalence were sought. Changes related to Guyon??s canal syndrome were also evaluated.

Results

From the 250 wrists, the anatomy of the Guyon??s canal was normal in 168 (67.2%) wrists; 73 (29.2%) wrists presented with anatomical variations; and 9 (3.6%) wrists had derangements causing Guyon??s canal syndrome. The cross-sectional area of the canal was 33?±?11?mm2 proximally and 45?±?19?mm2 distally. The canal??s length was approximately 40?±?4?mm. Among the 73 wrists with anatomical variations, there were aberrant muscles in 39 (53.4%) wrists, multiple ulnar nerve branching in 22 (30%) cases, increased amount of fat tissue inside the canal in 9 (12.3%) cases and hypoplastic hamulus in 3 (4.1%) cases. There were 9 (3.6%) symptomatic wrists with clinical and radiological features attributed to Guyon??s canal syndrome.

Conclusion

MRI is an excellent modality for the evaluation of the Guyon??s canal.     

Haemangiopericytoma of the thyroid gland in combination with Hashimoto’s disease

We present a hitherto unique case of haemangiopericytoma (HP) of the thyroid gland in a 15-year-old female patient suffering from Hashimotos disease for several months. Since angiogenesis has been discussed to play a major role in both diseases, we examined the expression of vascular endothelial growth factor (VEGF), VEGF receptors (VEGFRs) and platelet-derived growth factor receptors (PDGFRs). Most interestingly, strong expression of PDGFR and was found in spindle-shaped tumour cells and tumour vessels in HP, while VEGF and VEGFR type I and -II were negative in these regions. In contrast, VEGF was expressed in the lymphoid infiltrate of Hashimotos disease. Since PDGFR- is commonly expressed in pericytes, we suggest that the strong expression discovered in this study further supports the view that HP is derived from pericytes. The combination of HP and Hashimotos disease is most probably a coincidental event. However, this case confirms previous reports demonstrating that in patients with Hashimotos disease different neoplasias can occur.     

Crohn’s disease-specific pancreatic autoantibodies are specifically present in ruminants with paratuberculosis: Implications for the pathogenesis of the human disease

Abstract

Mycobacterium avium subspecies paratuberculosis (MAP) induces paratuberculosis (ptb) in ruminants and has clinical and histological features resebling Crohn’s disease (CD). Pancreatic autoantibodies (PAB) targeting glycoprotein 2 (GP2) are specifically found in CD, but it is currently unknown whether these autoantibodies can be found in ruminants with ptb. IgG anti-MAP and anti-GP2 antibodies were tested by ELISA in 286 ruminants (212 sheep and 74 cattle). PAB testing was performed by indirect immunofluorescence (IIF) using anti-sheep or anti-cattle specific antisera. PCR analysis confirmed the presence of MAP in anti-MAP positive samples. Anti-GP2 antibodies were more prevalent in anti-MAP antibody positive (26.9%) than in anti-MAP negative ruminants (8.7%, p?<?0.001). Anti-GP2 antibodies were found in 16/70 (22.9%) anti-MAP positive sheep compared to 10/142 (7%, p?=?0.001) anti-MAP antibody negative and in anti-MAP positive cattle than in negative counterparts (5/8 versus 8/66, p?=?0.003). Absorbance values for anti-GP2 antibodies were higher in cattle than in sheep (mean 21 AU/mL?±?25.4SD versus 12.2 AU/mL?±?23 SD, p?<?0.001). There was no correlation between anti-GP2 and anti-MAP antibody concentrations. Anti-GP2 antibodies persisted up to 1/1000 and showed the characteristic IIF pancreatic pattern seen by anti-GP2 antibody positive CD samples. This is the first study to demonstrate the presence of CD-specific GP2-reactive pancreatic autoantibodies in MAP-infected ruminants. Our data suggest that CD and ptb are characterised by an antigen-driven loss of immunological tolerance to GP2, implying commonalities in the immunopathogenesis of the human and ruminant inflammatory bowel disorder.     

Analysis of the parameters of oxidative stress in patients with Parkinson’s disease

The increasing data provides enough evidences confirming the involvement of free radicals and other reactive oxygen species (ROS) superoxide radical ( ^. O ₂ ^? ), nitric oxide (NO ^. ), hydrogen peroxide (H₂O₂) and hydroxyl radicals ( ^. OH) in a number of physiological and pathological processes. Imbalance between levels of ROS resulting in the body and the capacity of antioxidant defense mechanisms occur oxidative stress (OS). OS is related to a number of structural and functional damages to cells and is involved in the pathogenesis of many diseases, including neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease (PD), amyotrophic lateral sclerosis, and Huntington disease. Defects in oxidative phosphorylation and oxidative damage play an important role in neurodegenerative diseases. The aim of this study was to investigate some biomarkers of OS such as the level of lipid peroxidation measured as malondialdehyde (MDA) reactive products and activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in the blood of PD patients compared with control group of healthy volunteers. By the present research we report higher levels of MDA products and an imbalance in SOD and CAT enzyme activities in PD patients compared to the control group.     

Multimodal MRI of the hippocampus in Parkinson’s disease with visual hallucinations

Visual hallucinations carry poor prognosis in Parkinson’s disease. Here we tested the hypothesis that the hippocampus and visuospatial memory impairment play a central role in the pathology of PD with visual hallucinations. Multimodal magnetic resonance imaging of the brain was carried out in 12 people with PD and visual hallucinations; 15 PD individuals without hallucinations; and 14 healthy controls. Age, gender, cognitive ability, and education level were matched across the three groups. PD patients were taking dopaminergic medication. Hippocampal volume, shape, mean diffusivity (MD), and functional connectivity within the whole brain were examined. Visuospatial memory was compared between groups, and correlations with hippocampal MD, functional connectivity, and the severity of hallucinations were explored. There were no macrostructural differences across groups, but individuals with hallucinations had higher diffusivity in posterior hippocampus than the other two groups. Visuospatial memory was poorer in both PD groups compared to controls, and was correlated with hallucinations. Finally, hippocampal functional connectivity in the visual cortices was lower in those with hallucinations than other groups, and this correlated with visuospatial memory impairment. In contrast, functional connectivity between the hippocampus and default mode network regions and frontal regions was greater in the PD hallucinators compared to other groups. We suggest that hippocampal pathology, which disrupts visuospatial memory, makes a key contribution to visual hallucinations in PD. These findings may pave the way for future studies of imaging biomarkers to measure treatment response in those with PD who are most at risk of poor outcomes.     

Investigation of the Esophageal Rho-kinase Expression in Patients with Barrett’s Esophagus

Abstract

The mechanisms responsible for the malignant transformation in Barrett’s esophagus (BE) are still poorly understood. The authors have evaluated the role of Rho-kinase (ROCK1 and ROCK2) expressions in patients with BE. All patients underwent upper gastrointestinal system endoscopy, which was confirmed histologically. Real-time PCR revealed no marked change in gene expressions of ROCK1 and ROCK2 at mRNA levels in BE when compared to controls. Immunohistochemical and western blot analyses showed no change in ROCK1 and ROCK2 protein expressions in BE. This study demonstrates that Rho-kinase gene and protein expressions are not modified in BE.     

Pretreatment cerebral metabolic activity correlates with antidepressant efficacy of vagus nerve stimulation in treatment-resistant major depression: A potential marker for response?

BackgroundPretreatment brain activity in major depressive disorder correlates with response to antidepressant therapies, including pharmacotherapies and transcranial magnetic stimulation. The purpose of this trial was to examine whether pretreatment regional metabolic activity in selected regions of interest (ROIs) predicts antidepressant response following 12 months of vagus nerve stimulation (VNS) in 15 patients with treatment-resistant major depression (TRMD).MethodsFluorodeoxyglucose positron emission tomography (FDG PET) was used to assess regional mean relative cerebral metabolic rate for glucose (CMRGlu) in four ROIs (anterior insular, orbitofrontal, anterior cingulate, and dorsolateral prefrontal cortices) at baseline (prior to VNS activation). Depression severity was assessed at baseline and after 12 months of VNS using the Hamilton Depression Rating Scale (HDRS), with response defined as ≥ 50% reduction in HDRS from baseline.ResultsBaseline CMRGlu in the anterior insular cortex differentiated VNS responders (n = 11) from nonresponders (n = 4) and correlated with HDRS change (r = .64, p = .01). In a regression analysis, lower anterior insular cortex CMRGlu (p = .004) and higher orbitofrontal cortex CMRGlu (p = .047) together predicted HDRS change (R² = .58, p = .005). In a whole brain, voxel-wise analysis, baseline CMRGlu in the right anterior insular cortex correlated with HDRS change (r = .78, p = .001).LimitationsSample size was small, limiting statistical power; patients remained on their psychiatric medications; study was open-label and uncontrolled.ConclusionsThis preliminary study suggests that pretreatment regional CMRGlu may be useful in predicting response to VNS in TRMD patients.     

A potential therapeutic system for Alzheimer’s disease using adsorbents with alkyl ligands for removal of blood amyloid β

Amyloid beta proteins (Aβ) in the brain are the main cause of Alzheimer’s disease. Peripheral administration of Aβ-binding substances, which may act as a sink for Aβ from the brain, has been reported to reduce brain Aβ. We previously found C16-cellulose beads had high Aβ-removal activity in vitro. In this study, we investigated the optimum surface properties of adsorbents for removal of Aβ in vitro and in humans. Batch analysis was performed with porous cellulose beads or silica beads with or without 2–22 methylene groups. Aβ-removal activity of C16-cellulose beads increased with increasing alkyl chain length. In contrast, with cellulose the amount of Aβ removed by the silica beads decreased with increasing alkyl chain length. Cellulose beads with 16 or 22 methylene groups were best (over 99 % removal) among all the beads tested (p ≤ 0.01). The adsorbent surfaces were analyzed by near-infrared spectroscopy, which revealed that the optimum beads had a sufficiently hydrophobic surface with an appropriate amount of adsorbed water accessible on the surface. Aβ removal efficiency by C16-cellulose beads was investigated for 5 renal failure patients on hemodialysis, resulting in 51.1 ± 6.6 % for Aβ_1–40 and 43.8 ± 4.5 % for Aβ_1–42 (p ≤ 0.01). In conclusion, cellulose beads with 16 or 22 methylene groups and an appropriate amount of adsorbed water were the optimum Aβ adsorbents. The device with C16-cellulose beads had high Aβ removal activity in humans. These adsorbents might be useful for Alzheimer’s disease therapy.     

Paternal lineage of the Berbers from Aurès in Algeria: estimate of their genetic variation

Abstract

Background: Aurès is a vast territory in the east of Algeria, characterised by its traditional Berber settlement which has preserved its language and its rich history; its name goes back to antiquity and before the Roman conquest it was part of the territory of ancient Numidia. The Chaoui people in this region are one of Algeria’s largest Berber groups.

Aim: The aims were to investigate the level of genetic diversity of the Berbers of Aurès through the analysis of the paternal gene pool and to estimate the percentage of genetic variation among different geographical regions and linguistic groups from Algeria.

Subjects and methods: Twenty-three Y-STRs were genotyped in a sample of 218 unrelated males of the Berbers of Aurès. Algorithms were used to estimate the Y-chromosome haplogroups. Genetic distance, non-metric MDS and AMOVA were used to analyse the genetic relationships between sample groups.

Results: The paternal lineage of this sample of the Aurès region did not exhibit strong signals of differentiation with other samples from North-central, Northwest, and South Algeria. However, significant differences were found within this sample, demonstrating a high degree of heterogeneity.

Conclusion: The results demonstrate that Aurès people are isolated and closed, but nevertheless have quite different genetic profiles.     

Efficacy of cilostazol for the treatment of Raynaud’s phenomenon in systemic sclerosis patients

Cilostazol is a selective inhibitor of phosphodiesterase-III with antiplatelet, antithrombotic and vasodilating properties. The aim of our study was to evaluate the effect of the drug on vasculopathy and Raynaud’s phenomenon (RP), in a series of patients with systemic sclerosis (SSc), before and after cilostazol treatment. Twenty-one consecutive SSc patients with moderate or severe RP were enrolled in an open-label study. Cilostazol was administered at the dose of 100 mg twice a day, for 12 months. Evaluations included: daily RP attack diary documenting the frequency and duration of RP episodes, Health Assessment Questionnaire-Disability Index, scleroderma visual analogue scales (VAS), flow-mediated dilation and immunological status, including endothelin 1 and interleukin 6 plasma levels. Thirteen patients completed the study. RP duration and daily number episodes recorded over a 3-week period significantly decreased after cilostazol treatment (p = 0.0049 and p = 0.0067, respectively). VAS score indicated a significant amelioration of the patients’ perception of RP (p = 0.0117), and both baseline and post-ischemic brachial artery diameters were significantly increased after cilostazol treatment, as compared with basal values (p = 0.0119 and p = 0.0076, respectively). None of the patients developed digital ulcers during the study. A significant clinical improvement of RP was recorded in SSc patients undergoing cilostazol treatment. Study results indicate a potential role of cilostazol as oral maintenance therapy in SSc patients with RP.     

Knocking at the brain’s door: intravital two-photon imaging of autoreactive T cell interactions with CNS structures

Since the first applications of two-photon microscopy in immunology 10 years ago, the number of studies using this advanced technology has increased dramatically. The two-photon microscope allows long-term visualization of cell motility in the living tissue with minimal phototoxicity. Using this technique, we examined brain autoantigen-specific T cell behavior in experimental autoimmune encephalitomyelitis, the animal model of human multiple sclerosis. Even before disease symptoms appear, the autoreactive T cells arrive at their target organ. There they crawl along the intraluminal surface of central nervous system (CNS) blood vessels before they extravasate. In the perivascular environment, the T cells meet phagocytes that present autoantigens. This contact activates the T cells to penetrate deep into the CNS parenchyma, where the infiltrated T cells again can find antigen, be further activated, and produce cytokines, resulting in massive immune cell recruitment and clinical disease.