Laminin β4 is a constituent of the cutaneous basement membrane zone and additional autoantigen of anti-p200 pemphigoid

BACKGROUND

Anti-p200 pemphigoid is a subepidermal autoimmune blistering disease (AIBD) characterized by autoantibodies against a 200 kDa protein. Laminin γ1 has been described as target antigen in 70% to 90% of patients. No diagnostic assay is widely available for anti-p200 pemphigoid, which might be due to the unclear pathogenic relevance of anti-laminin γ1 autoantibodies.

OBJECTIVE

To identify a target antigen with higher clinical and diagnostic relevance.

METHODS

Immunoprecipitation, mass spectrometry, and immunoblotting were employed for analysis of skin extracts and sera of patients with anti-p200 pemphigoid (n = 60), other AIBD (n = 33), and healthy blood donors (n = 29). To localize the new antigen in skin, cultured keratinocytes and fibroblasts, quantitative real-time polymerase chain reaction and immunofluorescence microscopy were performed.

RESULTS

Laminin β4 was identified as target antigen of anti-p200 pemphigoid in all analyzed patients. It was located at the level of the basement membrane zone of the skin with predominant expression in keratinocytes.

LIMITATIONS

A higher number of sera needs to be tested to verify that laminin β4 is the diagnostically relevant antigen of anti-p200 pemphigoid.

CONCLUSION

The identification of laminin β4 as an additional target antigen in anti-p200 pemphigoid will allow its differentiation from other AIBD and as such, improve the management of these rare disorders.

The chemicals between us-First results of the cluster analyses on anatomy embalming procedures in the German-speaking countries

Hands-on courses utilizing preserved human tissues for educational training offer an important pathway to acquire basic anatomical knowledge. Owing to the reevaluation of formaldehyde limits by the European Commission, a joint approach was chosen by the German-speaking anatomies in Europe (Germany, Austria, Switzerland) to find commonalities among embalming protocols and infrastructure. A survey comprising 537 items was circulated to all anatomies in German-speaking Europe. Clusters were established for "ethanol"-, formaldehyde-based ("FA"), and "other" embalming procedures, depending on the chemicals considered the most relevant for each protocol. The logistical framework, volumes of chemicals, and infrastructure were found to be highly diverse between the groups and protocols. Formaldehyde quantities deployed per annum were three-fold higher in the "FA" (223 L/a) compared to the "ethanol" (71.0 L/a) group, but not for "other" (97.8 L/a), though the volumes injected per body were similar. "FA" was strongly related to table-borne air ventilation and total fixative volumes ≤1000 L. "Ethanol" was strongly related to total fixative volumes >1000 L, ceiling- and floor-borne air ventilation, and explosion-proof facilities. Air ventilation was found to be installed symmetrically in the mortuary and dissection facilities. Certain predictors exist for the interplay between the embalming used in a given infrastructure and technical measures. The here-established cluster analysis may serve as decision supportive tool when considering altering embalming protocols or establishing joint protocols between institutions, following a best practice approach to cater toward best-suited tissue characteristics for educational purposes, while simultaneously addressing future demands on exposure limits.

Brain Regional Differences in Hexanucleotide Repeat Length in X-Linked Dystonia-Parkinsonism Using Nanopore Sequencing

Objective

Our study investigated the presence of regional differences in hexanucleotide repeat number in postmortem brain tissues of 2 patients with X-linked dystonia-parkinsonism (XDP), a combined dystonia-parkinsonism syndrome modified by a (CCCTCT)_n repeat within the causal SINE-VNTR-Alu retrotransposon insertion in the TAF1 gene.

Methods

Genomic DNA was extracted from blood and postmortem brain samples, including the basal ganglia and cortex from both patients and from the cerebellum, midbrain, and pituitary gland from 1 patient. Repeat sizing was performed using fragment analysis, small-pool PCR-based Southern blotting, and Oxford nanopore sequencing.

Results

The basal ganglia (p < 0.001) and cerebellum (p < 0.001) showed higher median repeat numbers and higher degrees of repeat instability compared with blood.

Conclusions

Somatic repeat instability may predominate in brain regions selectively affected in XDP, thereby hinting at its potential role in disease manifestation and modification.

The glenocapsular ligament and the posterosuperior part of the joint capsule of the shoulder are well vascularized

PURPOSE

A detailed structural anatomy of the posterosuperior shoulder capsule and "glenocapsular ligament" is still rather unknown. The purpose of this study was meticulously to investigate and describe the structure and blood supply of the glenocapsular ligament on the posterosuperior shoulder joint capsule.

METHOD

Sixteen fixed and twelve fresh cadaveric shoulder specimens with a mean age of 73.4 (±6.4) years were analysed. Dissection without arterial injection was performed on the 16 fixed specimens-using an alcohol-formalin-glycerol solution. Before dissection, the 12 fresh specimens received of arterial injection a 10% aqueous dispersion of latex solution. After the injection, these shoulders were also fixed in an alcohol-formalin-glycerol solution.

RESULTS

The glenocapsular ligament was found in all 28 specimens. Single or double parallel-running bundles of connective tissue fibres were found to form a capsular-ligamentous structure on the posterosuperior part of the joint capsule. One part of the ligament was mediosuperior, another posterosuperior. The mediosuperior part varied in shape, and in 12 of 28 cases, it was absent. The glenocapsular ligament arose from the supraglenoid tubercle and posterior part of the collum scapulae and inserted into the semicircular humeral ligament. The posterior ascending branch of the circumflex scapular artery directly fed small branches laterally and medially to the joint capsule, supplying the glenocapsular ligament and the deep layer of the joint capsule.

CONCLUSION

The glenocapsular ligament is a constant anatomical structure that consists of one or two different parts. The glenocapsular ligament and the posterosuperior part of the joint capsule appear well vascularized via the posterior ascending branch of the circumflex scapular artery.

CLINICAL RELEVANCE

It is the hope of the authors that this anatomical study can help surgeons who perform open or arthroscopic surgery to the posterior part of the shoulder. Knowledge of the vascular anatomy presented in this study may be especially important when incisions are made to the posterior part of the shoulder, and should minimize the risk of complications.

Biomechanical evaluation of MPFL reconstructions: differences in dynamic contact pressure between gracilis and fascia lata graft

PURPOSE

To evaluate the knee kinematics of the intact, MPFL-ruptured and MPFL-reconstructed knee and, moreover, to compare dynamic patellofemoral contact pressure of the gracilis tendon and the fascia lata as an alternative graft option for reconstruction of the MPFL.

METHODS

Eight paired human cadaveric knees were fixed in a custom-made fixation device. Patellofemoral contact pressure was assessed during a dynamic flexion movement at 15°-30°-45°-60°-75° and 90° using a pressure-sensitive film (Tekscan). The medial patellofemoral ligament was cut, and measurements were repeated. Finally, reconstruction of the MPFL was performed using the gracilis tendon (group I) or a fascia lata graft (group II). Tunnel localization was performed under fluoroscopic control. Grafts were fixed at 30° of flexion, and pressure measurements were repeated.

RESULTS

Incision of the medial patellofemoral ligament significantly reduced patellofemoral contact pressure at 15°, 30° and 45° of knee flexion compared to the intact knee (p < 0.05), whereas reconstruction of the MPFL using either gracilis tendon of the fascia lata was able to restore pressure distributions at 15° and 30° of knee flexion. However, in the hamstring group, reconstruction of the MPFL revealed a significantly reduced contact pressure at 45° of flexion (p = 0.038) compared to the intact knee. In the fascia lata group, a significant reduction in patellofemoral contact pressure was observed after MPFL reconstruction at 45°, 60°, 75° and 90° of knee flexion (p < 0.05).

CONCLUSIONS

Anatomic reconstruction of the MPFL with either a gracilis or a fascia lata graft showed comparable patellofemoral pressure distributions which were closely restored compared to the native knee. Therefore, the fascia lata has shown to be a viable alternative to the gracilis tendon for reconstruction of the MPFL. However, anatomic reconstruction of the MPFL may lead to persistently altered patellofemoral contact pressure during knee flexion compared to the native knee independent of the tested graft.

Blood supply of the subacromial bursa and rotator cuff tendons on the bursal side

PURPOSE

Vascularity of the subacromial bursa and rotator cuff tendons is key factors in the pathogenesis of subacromial bursitis and impingement syndrome, rotator cuff tendinitis, and rotator cuff tears. The purpose of this study was to investigate and describe blood supply to the cranial and caudal parts of the subacromial bursa and the vascularity of the rotator cuff tendons on the bursal side.

METHODS

Fourteen fresh cadaveric shoulders from six females and eight males with a mean age of 71.7 (±10.8) years were studied. Before dissection, an arterial injection of 10% aqueous dispersion of latex was administered. Post-injection, the shoulders were fixed in an alcohol-formalin-glycerol solution.

RESULTS

The cranial and caudal bursa of all specimens was mainly supplied by the thoracoacromial, suprascapular, and anterior and posterior circumflex humeral arteries. The cranial part of the bursa was supplied anteriorly by the thoracoacromial artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third. The caudal part received arterial blood anteriorly from the anterior circumflex humeral artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third of the caudal bursa. In addition, the suprascapular artery branched at the upper surface of the coracohumeral ligament, and the subcoracoid artery branched at the under surface of the same ligament.

CONCLUSION

The subacromial bursa appears well vascularized. The results of the present investigation showed that blood supply to the subacromial bursa at the caudal part and rotator cuff tendons on the bursal side was linked to the same arteries. The subcoracoid artery supplied interval rotator structures close to the caudal bursa. It is the wish of the authors that this meticulous anatomical work will help surgeons in their day-to-day clinical work, e.g. to minimize the risk of complications such as perioperative bleeding.

Mitochondrial gene polymorphisms alter hepatic cellular energy metabolism and aggravate diet-induced non-alcoholic steatohepatitis

Objective

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is associated with an enhanced risk for liver and cardiovascular diseases and mortality. NAFLD can progress from simple hepatic steatosis to non-alcoholic steatohepatitis (NASH). However, the mechanisms predisposing to this progression remain undefined. Notably, hepatic mitochondrial dysfunction is a common finding in patients with NASH. Due to a lack of appropriate experimental animal models, it has not been evaluated whether this mitochondrial dysfunction plays a causative role for the development of NASH.

Methods

To determine the effect of a well-defined mitochondrial dysfunction on liver physiology at baseline and during dietary challenge, C57BL/6J-mt^FVB/N mice were employed. This conplastic inbred strain has been previously reported to exhibit decreased mitochondrial respiration likely linked to a non-synonymous gene variation (nt7778 G/T) of the mitochondrial ATP synthase protein 8 (mt-ATP8).

Results

At baseline conditions, C57BL/6J-mt^FVB/N mice displayed hepatic mitochondrial dysfunction characterized by decreased ATP production and increased formation of reactive oxygen species (ROS). Moreover, genes affecting lipid metabolism were differentially expressed, hepatic triglyceride and cholesterol levels were changed in these animals, and various acyl-carnitines were altered, pointing towards an impaired mitochondrial carnitine shuttle. However, over a period of twelve months, no spontaneous hepatic steatosis or inflammation was observed. On the other hand, upon dietary challenge with either a methionine and choline deficient diet or a western-style diet, C57BL/6J-mt^FVB/N mice developed aggravated steatohepatitis as characterized by lipid accumulation, ballooning of hepatocytes and infiltration of immune cells.

Conclusions

We observed distinct metabolic alterations in mice with a mitochondrial polymorphism associated hepatic mitochondrial dysfunction. However, a second hit, such as dietary stress, was required to cause hepatic steatosis and inflammation. This study suggests a causative role of hepatic mitochondrial dysfunction in the development of experimental NASH.

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C57BL/6J-mt^FVB/N mice (mt-ATP8, nt7778 G/T) display hepatic mitochondrial dysfunction.

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C57BL/6J-mt^FVB/N mice display alterations in hepatic energy metabolism.

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C57BL/6J-mt^FVB/N mice show no spontaneous hepatic steatosis or inflammation.

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C57BL/6J-mt^FVB/N mice are susceptible to diet induced NASH.

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Study demonstrates causative role of mitochondrial dysfunction for NASH development.

Biomechanical evaluation of knee kinematics after anatomic single- and anatomic double-bundle ACL reconstructions with medial meniscal repair

PURPOSE

To evaluate knee laxity after anatomic ACL reconstruction with additional suture repair of a medial meniscus tear.

METHODS

Kinematics of the intact knee were determined in 12 human cadaver specimens in response to a 134-N anterior tibial load (aTT) and a combined rotatory load of 10 Nm valgus and 4 Nm internal tibial rotation (aTTPS) using a robotic/universal force moment sensor testing system. Subsequently, the ACL was resected following the creation of a standardized tear of the medial meniscus, a standard meniscus repair and an ACL reconstruction using an anatomic single-bundle (6) or an anatomic double-bundle technique (6). Knee kinematics were determined following every sub-step.

RESULTS

Significant increase of aTT in the ACL-deficient knee was found (p ≤ 0.001) with a further increase in the ACL-deficient knee with additional medial meniscal rupture (p ≤ 0.001). ACL reconstructions significantly decreased aTT compared with the ACL and meniscus-ruptured knee. No significant differences were seen between the intact knee and the ACL-reconstructed knee with additional meniscal repair (p < 0.05). In response to a simulated pivot shift, aTTPS in the intact knee significantly increased in the ACL-deficient knee and meniscus-ruptured knee (p = 0.005). No significant differences in knee kinematics were found between SB as well as DB ACL reconstruction with additional medial meniscal repair compared with the intact knee. Comparison of SB versus DB ACL reconstruction did not reveal any significant differences in a simulated Lachman test or simulated pivot shift test (n.s.).

CONCLUSIONS

aTT as well as aTTPS significantly increased with ACL deficiency compared with the intact knee; additional medial meniscal rupture further increased aTT. Anatomic ACL reconstruction with medial meniscal repair did not reveal significant differences in knee kinematics compared with the intact knee. Comparison of anatomic SB versus DB ACL reconstruction with additional repair of the medial meniscus did not show significant differences neither in a simulated Lachman nor in a simulated pivot shift test.

Evaluation of local alterations in femoral bone mineral density measured via quantitative CT

The aim of this study was to investigate the accuracy of bone mineral density (BMD) determined by quantitative computed tomography (qCT) based on in situ and ex situ scans of cadavers of variable stature. The influence of surrounding tissue on the quantification of CT images of ex situ scanned femora was investigated in air and in water and compared with the in situ scanned femora. The study showed that the surrounding tissue has an impact on the grey value-based representation of the scanned object as well as on the calibration of BMD, influencing the determination of BMD. Local differences in BMD of up to 17.5% were observed, which might originate from beam hardening artifacts.

A fully 3D approach for metal artifact reduction in computed tomography

PURPOSE

In computed tomography imaging metal objects in the region of interest introduce inconsistencies during data acquisition. Reconstructing these data leads to an image in spatial domain including star-shaped or stripe-like artifacts. In order to enhance the quality of the resulting image the influence of the metal objects can be reduced. Here, a metal artifact reduction (MAR) approach is proposed that is based on a recomputation of the inconsistent projection data using a fully three-dimensional Fourier-based interpolation. The success of the projection space restoration depends sensitively on a sensible continuation of neighboring structures into the recomputed area. Fortunately, structural information of the entire data is inherently included in the Fourier space of the data. This can be used for a reasonable recomputation of the inconsistent projection data.

METHODS

The key step of the proposed MAR strategy is the recomputation of the inconsistent projection data based on an interpolation using nonequispaced fast Fourier transforms (NFFT). The NFFT interpolation can be applied in arbitrary dimension. The approach overcomes the problem of adequate neighborhood definitions on irregular grids, since this is inherently given through the usage of higher dimensional Fourier transforms. Here, applications up to the third interpolation dimension are presented and validated. Furthermore, prior knowledge may be included by an appropriate damping of the transform during the interpolation step. This MAR method is applicable on each angular view of a detector row, on two-dimensional projection data as well as on three-dimensional projection data, e.g., a set of sequential acquisitions at different spatial positions, projection data of a spiral acquisition, or cone-beam projection data.

RESULTS

Results of the novel MAR scheme based on one-, two-, and three-dimensional NFFT interpolations are presented. All results are compared in projection data space and spatial domain with the well-known one-dimensional linear interpolation strategy.

CONCLUSIONS

In conclusion, it is recommended to include as much spatial information into the recomputation step as possible. This is realized by increasing the dimension of the NFFT. The resulting image quality can be enhanced considerably.

Erythema annulare centrifugum: results of a clinicopathologic study of 73 patients

Erythema annulare centrifugum is classified generally into a superficial and a deep type. Whether those types are variants of the same process or unrelated to one another, and whether they represent non-specific patterns or specific clinico-pathologic entities, is controversial. To answer those questions, we analyzed 82 biopsy specimens from 73 patients with a clinical and histopathologic diagnosis of erythema annulare centrifugum, gyrate erythema, or figurate erythema regarding a variety of clinical and histopathologic findings. We found substantial differences between cases with a wholly superficial type and cases with a superficial and deep infiltrate. Clinically, a collarette of scales was seen only in the superficial type. Histopathologically, some findings were much more common in the superficial type (eg, spongiosis, parakeratosis, crusts, edema of the papillary dermis, epidermal hyperplasia) and others in the deep type (eg, sleeve-like arrangement of the infiltrate, melanophages, subtle vacuolar changes at the dermo-epidermal junction, individual necrotic keratinocytes). Whereas cases of the superficial type could be distinguished from differential diagnoses by a variety of clinical and histopathologic findings, most cases of the deep type showed subtle signs of lupus erythematosus. Neither type was associated consistently with any other systemic disease. Because the superficial and the deep type of erythema annulare centrifugum seem to be unrelated to one another, they should not be referred to by the same name. We believe that the term should be reserved for the superficial type because the latter seems to be a specific clinico-pathologic entity. By contrast, most cases of the deep type seem to be annular examples of tumid lupus erythematosus and should be diagnosed that way. If findings militate against the diagnosis of lupus erythematosus, we suggest using a descriptive term that signals non-specificity-namely, deep figurate erythema.

A tumorous type of pulmonary rhabdomyomatous dysplasia

We report an extraordinary case of tumorous type of rhabdomyomatous dysplasia without any other malformation in a fetus of 23 weeks gestation. Histologically, autopsy showed distinctive striated muscle tissue in the upper and middle lobes of the right lung. Unusual in this case, compared with previously published reports, is the absence of further malformations, the occurrence in the apical parts of the lung and the marked degree of rhabdomyomatous dysplasia. The case report is followed by a differential diagnosis, review of the literature and discussion of the pathogenesis.

LE or not LE--that is the question: an unsuccessful attempt to separate lymphocytic infiltration from the spectrum of discoid lupus erythematosus

Lymphocytic infiltration of the skin (LIS) has been claimed to be a distinct entity that differs from discoid lupus erythematosus (DLE) by the lack of epidermal changes, negative immunofluorescence tests, and differences in the composition of the inflammatory cell infiltrate. In studies that sought to distinguish both conditions, however, cases of established lupus erythematosus without epidermal involvement have not been considered. We studied 72 patients with the clinical and histopathologic diagnosis of either LIS or DLE in regard to the same clinical, histopathologic, immunofluorescence, and immunohistochemical criteria. No significant differences were noted between cases with and without epidermal involvement on the one hand and between cases with and without immunofluorescence or clinical findings suggestive of lupus erythematosus on the other. Based on our findings, it is not possible to separate LIS from the spectrum of DLE.

Lichen amyloidosus: a consequence of scratching

BACKGROUND

Lichen amyloidosus (LA) is generally said to be a pruritic type of amyloidosis of unknown cause. Histopathologically, it is characterized by epidermal changes of lichen simplex chronicus and by deposits of amyloid in the papillary dermis that are derived from keratin peptides of necrotic keratinocytes. Chronic scratching is responsible for the development of lichen simplex chronicus and may lead to necrosis of individual keratinocytes.

OBJECTIVE

Our purpose was to evaluate whether chronic scratching may also be responsible for the formation of amyloid in LA.

METHODS

We studied patients with LA in regard to histopathologic findings, onset of pruritus, associated diseases, and response to treatment.

RESULTS

In most cases, pruritus had preceded the skin lesions. Eight of nine patients suffered from diseases other than LA that may be associated with pruritus. Histopathologically, amyloid was confined to areas that also showed signs of lichen simplex chronicus. Systemic treatment with sedating antihistamines and intense local treatment with corticosteroids were found to be effective.

CONCLUSION

LA is considered to be a variant of lichen simplex chronicus in which scratching leads to necrosis of keratinocytes and eventually to the formation of amyloid in the papillary dermis. Because chronic scratching seems to be the cause and not the result of the deposits of amyloid, treatment should be directed at the amelioration of pruritus.

Melanoma in situ versus melanocytic hyperplasia in sun-damaged skin. Assessment of the significance of histopathologic criteria for differential diagnosis

For differentiation of melanoma in situ (MIS) from melanocytic hyperplasia (MH) in sun-damaged skin, several criteria have been proposed. To assess sensitivity and specificity of those criteria, we examined the epidermis adjacent to 50 consecutive basal cell carcinomas and 50 MISs in skin with significant solar elastosis. The most valuable criteria for the diagnosis of MIS, as opposed to MH, were presence of nests of melanocytes, irregular distribution of melanocytes, descent of melanocytes far down adnexal epithelial structures, irregular distribution of pigment, presence of melanocytes above the junction, a high number of melanocytes, pleomorphism of melanocytes, and atypical nuclei of melanocytes. Other criteria, e.g., collapse of cytoplasm around nuclei of melanocytes; flattening of rete ridges; differences in the area, shape, and contour of nuclei of melanocytes as assessed by nuclear morphometry; and presence of melanocytes stained by HMB-45 and Ki-67/MIB-1 monoclonal antibodies, were found to be of low or no value for differential diagnosis.

[Skin infections caused by Mycobacterium gordonae. Case report and review of the literature]

Mycobacterium gordonae is an atypical mycobacterium of very low pathogenic potential. It is widely distributed in soil and water and often detected on the mucous membranes of healthy persons. In recent years, there have been numerous reports of infections by M. gordonae in immunocompromised patients. In contrast, only four cases of skin infections by M. gordonae in immunocompetent patients have been published. We report on another patient without evidence of immunodeficiency who developed an atypical mycobacteriosis after a thorn injury during gardening. M. gordonae was isolated by tissue culture. The skin lesion cleared completely after treatment with doxycycline for three months.

Expression of gp100 in melanoma metastases resected before or after treatment with IFN alpha and IL-2

The melanosomal protein gp100 was recently described as an antigen associated with tumor rejection in adoptive immunotherapy using tumor-infiltrating lymphocytes. In this study, we investigated whether the expression of gp100 in melanoma cells correlates with responsiveness to treatment with interferon-alpha and interleukin-2. Using the monoclonal antibody HMB-45 recognizing gp100, we examined metastatic tissue resected before therapy in 44 patients with melanoma including 9 patients with subsequent complete or partial remission. A very heterogeneous pattern of gp100-expression was found between patients, but the percentage of gp-100 positive cells in different metastases resected from the same patient was rather constant. This suggests that the gp100 expression determined in a single metastasis may be judged as being representative for other metastatic lesions of a patient. We found no correlation between expression of gp100 and responsiveness to subsequent immunotherapy. Our results show that the lack of gp100 before therapy is not associated with decreased responsiveness to subsequent cytokine treatment.

[Differential diagnosis of interface dermatitis]

Interface-dermatitis is defined as a type of cutaneous inflammation in which the dermo-epidermal junction is obscured. It is associated with vacuolar alteration at the dermo-epidermal junction, necrosis of individual keratinocytes, and melanophages in the papillary dermis. Differentiation between the large number of diseases characterized by an interface dermatitis can be accomplished by analysis of the density, localization, and composition of the infiltrate, number and localization of necrotic keratinocytes, and alterations of the epidermis (hyperplastic vs. atrophic). Several methods for a systematic approach to the diagnosis of interface dermatitides have been proposed; an own scheme combining different aspects of those methods is presented.