Potential thioflavin T false positives in lipomembranous changes in adipocytes during systemic amyloidosis diagnosis.

The diagnosis of systemic amyloidosis relies on the detection of amyloid deposition in the tissue, often utilizing biopsy specimens from the abdominal skin owing to their minimal invasiveness. Several amyloid staining methods, including Congo Red, Direct Fast Scarlet (DFS), and Thioflavin T (ThT), have been employed for visualization. Lipomembranous fat necrosis (LFN) is a non-specific reaction pattern of adipose tissue to injury, typically derived from blood insufficiency across a wide range of clinical conditions or diseases. It is characterized by the presence of eosinophilic, crenulated, and/or serpiginous membranes in fat lobules. We encountered a patient in whom ThT yielded suspiciously positive results in amyloidosis screening tests. Furthermore, our retrospective observations suggested that ThT staining was positive for LFN, whereas DFS and Congo red staining yielded negative results. The awareness that LFN can result in false-positive ThT staining during amyloid screening is crucial to avoiding the misdiagnosis of systemic amyloidosis. Furthermore, skin samples should not be collected from areas prone to developing lipomembranous changes. The use of more than two different stains for skin biopsy specimens is recommended.

Multiple magnetic scattering in small-angle neutron scattering of Nd-Fe-B nanocrystalline magnet.

We have investigated the influence of multiple scattering on the magnetic small-angle neutron scattering (SANS) from a Nd-Fe-B nanocrystalline magnet. We performed sample-thickness- and neutron-wavelength-dependent SANS measurements, and observed the scattering vector dependence of the multiple magnetic scattering. It is revealed that significant multiple scattering exists in the magnetic scattering rather than the nuclear scattering of Nd-Fe-B nanocrystalline magnet. It is considered that the mean free path of the neutrons for magnetic scattering is rather short in Nd-Fe-B magnets. We analysed the SANS data by the phenomenological magnetic correlation model considering the magnetic microstructures and obtained the microstructural parameters.

Exchange coupling interaction in L10-FePd/α-Fe nanocomposite magnets with large maximum energy products.

Nanocomposite magnets (NCMs) consisting of hard and soft magnetic phases are expected to be instrumental in overcoming the current theoretical limit of magnet performance. In this study, structural analyses were performed on L1(0)-FePd/α-Fe NCMs with various hard/soft volume fractions, which were formed by annealing Pd/γ-Fe(2)O(3) heterostructured nanoparticles and pure Pd nanoparticles. The sample with a hard/soft volume ratio of 82/18 formed by annealing at 773 K had the largest maximum energy product (BH(max) = 10.3 MGOe). In such a sample, the interface between the hard and soft phases was coherent and the phase sizes were optimized, both of which effectively induced exchange coupling. This exchange coupling was directly observed by visualizing the magnetic interaction between the hard and soft phases using a first-order reversal curve diagram, which is a valuable tool to improve the magnetic properties of NCMs.

Eccrine squamous syringometaplasia and syringomatous hyperplasia in association with linear scleroderma.

It is now well recognized that syringomatous hyperplasia with squamous syringometaplasia is a type of pseudoepitheliomatous hyperplasia responding to a variety of stimuli. We report a case of linear scleroderma with this process. Histopathology of the lesion showed numerous solid and cystic epithelial structures with squamous metaplasia within typical sclerodermatous skin lesions. Although the pathogenesis of the process remains unclear, dermal-derived growth factors in scleroderma and/or the mechanical effect of sclerosis could stimulate the proliferative response of eccrine epithelium. To the best of our knowledge, the association of syringomatous hyperplasia with eccrine squamous syringometaplasia and linear scleroderma has not been described previously.

Aberrant expression of apoptosis-related molecules in psoriatic epidermis.

Apoptosis is a physiological form of cell death that is responsible for the deletion of cells. Epidermal keratinocytes are supposed to be regulated by cell proliferation and cell death leading to structural homeostasis. Psoriatic skin shows marked thickening of the epidermis, suggesting the imbalance of the homeostasis, which might be related to abnormal apoptotic process. We investigated the expression of various apoptosis-related molecules in the psoriatic hyperproliferative epidermis. Real time quantitative RT-PCR analyses revealed that mRNAs of Fas, Bcl-xL, Bax and ICAD (inhibitor of caspase 3-related DNase) of the psoriatic involved epidermis were increased by 4.2-, 2.8-, 2.6- and 5.6-fold, respectively, compared with the uninvolved epidermis. In contrast, Bcl-2 expression in the involved epidermis was one-third suppressed compared with the uninvolved epidermis. No significant difference in the expression of mRNAs of Fas ligand or CAD (caspase 3-related DNase) was detected between the involved and uninvolved epidermis. Western blot analysis and immunohistochemical studies showed compatible results obtained by RT-PCR analyses. Although active caspase 3 was slightly increased in the involved epidermis, apoptotic cells were marginally detected. These results indicate that psoriatic epidermis shows aberrant expression of apoptosis-related molecules representing suppressed apoptotic process, which might be related to characteristic histopathology.