Horn Cells Research Articles

Comparison of posterior root remnant cells and horn cells of the medial meniscus

ABSTRACT Purpose/Aim of the study Previous studies have noted distinctions between medial meniscus posterior root and horn cells. However, the characteristics of root remnant cells have not been explored in detail. The purpose of this study was to evaluate the gene expression levels, proliferation, and resistance to mechanical stress of remnant and horn cells. Materials and Methods Medial meniscus tissue samples were obtained from patients who underwent total or uni-compartmental knee arthroplasty. Cellular morphology, sry-type HMG box 9, type II collagen, and chondromodulin-I gene expression levels were analyzed. Collagen synthesis was assessed by immunofluorescence staining. Proliferation analysis after 4 h-cyclic tensile strain was performed. Results Horn cells displayed triangular morphology, whereas root remnant cells appeared fibroblast-like. sry-type HMG box 9 mRNA expression levels were similar in both cells, but type II collagen and chondromodulin-I mRNA expressions were observed only in horn cells. The ratio of type II collagen-positive cells in horn cells was about 10-fold higher than that in root remnant cells, whereas the ratio of sry-type HMG box 9-positive cells was similar. A significant increase in proliferation was observed in root remnant cells compared to that in horn cells. Further, under cyclic tensile strain, the survival rate was higher in root remnant cells than in horn cells. Conclusions Medial meniscus root remnant cells showed higher proliferation and resistant properties to cyclic tensile strain than horn cells and showed no chondromodulin-I expression. Preserving the medial meniscus posterior root remnant during pullout repair surgery might maintain mechanical stress-resistant tissue and support healing.

Differences between the root and horn cells of the human medial meniscus from the osteoarthritic knee in cellular characteristics and responses to mechanical stress

BackgroundMany histological, mechanical, and clinical studies have been performed on the medial meniscus posterior root attachment, as it often tears in patients with osteoarthritic knee. Medial meniscal root repair is recommended in clinical situations; however, to date, no studies have examined the differences between meniscal root and horn cells. The aim of this study was, therefore, to investigate the morphology, reaction to cyclic tensile strain, and gene expression levels of medial meniscal root and horn cells. MethodsMeniscal samples were obtained from the medial knee compartments of 10 patients with osteoarthritis who underwent total knee arthroplasty. Root and horn cells were cultured in Dulbecco's modified Eagle's medium without enzymes. The morphology, distribution, and proliferation of medial meniscal root and horn cells, as well as the gene and protein expression levels of Sry-type HMG box 9 and type II collagen, were determined after cyclic tensile strain treatment. ResultsHorn cells had a triangular morphology, whereas root cells were fibroblast-like. The number of horn cells positive for Sry-type HMG box 9 and type II collagen was considerably higher than that of root cells. Although root and horn cells showed similar levels of proliferation after 48, 72, or 96 h of culture, more horn cells than root cells were lost following a 2-h treatment with 5% and 10% cyclic tensile. Sry-type HMG box 9 and α1(II) collagen mRNA expression levels were significantly enhanced in both cells after 2- and 4-h cyclic tensile strain (5%) treatment. ConclusionsMedial meniscal root and horn cells have distinct morphologies, reactions to mechanical stress, and cellular phenotypes. Our results suggest that physiological tensile strain is important to activate extracellular matrix production in horn cells.

Expression and Localization of p80 Interleukin-1 Receptor Protein in the Rat Spinal Cord

The biological effects of interleukin (IL)-1 are mediated by two distinct receptors, the p80 or type I (IL-1RI) and p68 or type II (IL-1RII) receptors. Because IL-1RII has a short, 29-amino acid cytoplasmic domain which may not be sufficient for signaling, there is considerable evidence indicating that IL-1 may signal exclusively through the IL-1RI receptor. Here, we report the expression, distribution, and cellular localization of the IL-1RI protein in the adult rat spinal cord in vivo and embryonic spinal cord in vitro. We found that IL-1RI was expressed in both the gray and white matter throughout the entire length of the spinal cord and was localized in neurons of the anterior horn, astrocytes, oligodendrocytes, and central canal ependymal cells. Interestingly, resting microglia were negative for IL-1RI. In primary cultures obtained from the embryonic day (E) 15 rats, IL-1RI was expressed in neurons, astrocytes, and oligodendrocytes as well as microglia. These data provide both in vivo and in vitro evidence that neurons and glial cells express the IL-1RI proteins. The differential expression of IL-1RI in the developing, but not mature, microglia may indicate the difference of these cells in response to IL-1 stimuli during maturation. The distribution and cellular localization of IL-1RI proteins in the spinal cord provide a molecular basis for understanding the reciprocal interaction between the immune and the central nervous systems.

Characteristics of Claw Horn Microstructure and the Effect of Flooring Systems on Horn Quality

Introduction: Interactions between horn quality and flooring systems significantly impact on claw health. Poor horn quality is associated with reduced milk yield, painful lesions or slaughtering. Horn quality is determined by horn cells, intercellular cement and hoof horn architecture, i.e. the structure and arrangement of the horn tubules. Soft and elastic flooring systems have been reported to have a positive influence on the microstructure of hoof horn.Aims: We wanted to correlate the microstructure of claw horn to the horn quality in a large number of samples and detect influences of the flooring system on hoof horn microstructure.Methods: Samples were obtained from two different studies: 40 cows from Hohenheim/Germany kept on slatted floor and subsequently on rubber mats for 4 months; 1000 cows from 11 farms in Luxembourg, kept on concrete floor. From all samples 7 μm‐sections were cut and stained with the PAS‐reaction. Morphometry was done with the LuciaG©‐software (Nikon GmbH, Düsseldorf, Germany) and statistical analysis was performed with SPSS® (SPSS Inc., Chicago, IL, USA). Parameters measured were area, minimal and maximal diameter of both medulla and cortex of horn tubules. Statistical analysis included: tubules per visual field, area per visual field, total medulla area, total cortex area and the limiting values of diameters.Results: Luxembourg samples showed consistency of tubule‐parameters between both dates; all farms showed an average number ranging from 13.36 to 14.79 tubules per visual field. Hohenheim horn from the hard flooring showed 19.9 and horn of the same animals kept on rubber floor showed 20.5 tubules per visual field. Maximum diameter of hard‐floor horn is 55 μm whereas 45 μm in animals kept on rubber floor.Conclusions: The results show that genetic/individual differences take smaller influence on horn quality than housing systems. These outcomes provide evidence for the economical and animal welfare benefit of soft and elastic flooring systems. Further research will focus on correlation of biodata, such as physiological state, lactation, age, and claw horn microstructure.This work was supported by Biopsytec/Rheinbach.

Premature keratinocyte death and expression of marker proteins of apoptosis in human skin after UVB exposure.

Epidermal keratinocytes undergo a process of terminal differentiation or cornification that in many aspects resembles apoptosis. It is characterized by the elimination of cell nuclei within the granular layer, whereas the cytoplasm is transformed into horn cells. Premature death of keratinocytes can be induced by extrinsic factors such as UV irradiation. We investigated the time-dependent expression of apoptotic marker proteins in the skin of one healthy human volunteer after irradiation with a fourfold minimal erythema dose (MED) of UVB. The data were supplemented by including healthy skin areas of biopsies from patients UVB-irradiated for therapeutic reasons. Punch biopsies were analysed by in situ end-labelling (ISEL) for DNA strand breaks and by immunohistochemistry for expression of p53, bcl-2, active caspase-3 and its proform, and deoxyribonuclease I (DNase I). Keratinocytes with pyknotic nuclei were first detected 6 h after UVB exposure, and apoptotic keratinocytes (sunburn cells) 12 h after exposure. These aggregated to sunburn bodies after 24 h. In control skin, nuclei with DNA strand breaks were only occasionally detected in the granular layer but 6 h after UVB irradiation in the spinous layer. After 12 h, many sunburn cells were ISEL-positive and positively stained for active caspase-3, P53, and DNase I. Morphometric evaluation of the immunohistochemical data demonstrated that maximal upregulation of P53, DNase I and activation of caspase-3 occurred 12 h after irradiation and in advance of the peak of apoptotic cell death reached after 24 h as verified by ISEL. In contrast, strong Bcl-2 immunostaining appeared restricted to presumed melanocytes and basal cells but was not increased after UVB irradiation.

Intraoperative brain mapping techniques in neuro-oncology.

Intraoperative brain mapping techniques are utilized in neuro-oncology to maximize the extent of tumor resection and seizure control, and minimize the operative morbidity. Direct stimulation mapping of the cortex and subcortical descending motor pathways will localize the rolandic cortex, dominant language speech zones and motor tracts in the internal capsule, cerebral peduncle and corticospinal tract/anterior horn cells. Electrocorticography identifies epileptogenic areas that histologically are distinctly devoid of neoplastic infiltration. Seizure control is maximal when seizure foci are resected in addition to the tumor nidus.

Post-Herpetic Neuralgia

The pathological features associated with post-herpetic neuralgia require further study. We report here 5 cases, 3 with severe post-herpetic neuralgia (PHN) and 2 with no persistent pain. The findings of dorsal horn atrophy and cell, axon and myelin loss with fibrosis in the sensory ganglion were found only in patients with persistent pain. Marked loss of myelin and axons in the nerve and/or sensory root were found in cases with and without pain. Some evidence is presented for a more generalized subacute or chronic inflammatory process which may explain the clinical features of some patients. Further studies will be necessary to fully describe the morbid anatomy of this disorder.

Keratoma hereditaria mutilans: Report of a case with successful surgical treatment

A case of constriction band at the fingers arising from keratosis palmoplantaris is reported. Excision of the band and closure of wound by Z-plasties resulted in complete relief of clinical symptoms and vascular insufficiencies. Histologic examination revealed the variability of this skin lesion even in the same patient. The sparsity of keratohyaline matrix in the horn cells in the skin may contribute to the constriction ring formation.

Squamous differentiation in carcinoma in situ of the cervix uteri. A cyto-histological correlation of malignant intraepithelial lesions with invasive carcinoma.

Cervical biopsies from 97 women with malignant cells in cervical scrape smears have been studied. Forty-eight patients had invasive squamous carcinoma, and 49 had intraepithelial lesions. Of these, six had dedifferentiated carcinoma in situ, nine had the differentiated lesions generally known as ;severe dysplasia', and 29 had both; the severity of the dysplasia remained doubtful in five patients. The ;severe dysplasia' was compared with invasive carcinoma. A cellular analysis of the biopsies showed that the two categories have a number of features in common, chiefly the presence of atypical and normal mitoses, nucleoli, horn cells, and giant cells. The stratification of the epithelium in ;severe dysplasia' is invariably abnormal and the architecture closely resembles that of invasive carcinoma. The cells in the smears from ;severe dysplasia' are similar to those in invasive carcinoma. It is suggested on the basis of these observations that a ;severe dysplasia' should be interpreted as a differentiated carcinoma in situ.