Ricardo Paniagua

Effects of immobilization on fetal bone development. A morphometric study in newborns with congenital neuromuscular diseases with intrauterine onset

SummaryThe effects of immobilization on fetal bone development were studied through postmortem radiographs in 11 newborns with congenital neuromuscular diseases (CNMD) of intrauterine onset. Quantitative parameters were determined in the following bones: tibia, femur, humerus, radius, 3rd lumbar vertebra, and 5th rib. Thirty stillborns or newborns of similar gestational age and deceased from causes other than neuromuscular or related diseases were used as controls. No significant differences in bone lengths were observed between both groups. However, external diameters, cortex thicknesses, and cortical areas values were significantly lower in newborns with CNMD than in the control group. In newborns with CNMD, the medullary diameter of long bones showed good correlation with gestational age. However, this diameter was greater than that expected according to the reduced external diameter. These results suggest that intrauterine immobilization induces a decrease in mechanical usage of bone, mainly influencing bone modeling and probably bone remodeling. No changes were observed in longitudinal bone growth. Bones showed osteopenia and mechanical defects and were prone to fractures. In summary, reduced immobilizationin utero produces bone osteoporosis of the fetus.

Changes in the long bones due to fetal immobility caused by neuromuscular disease. A radiographic and histological study.

The long bones in eleven newborn infants who had neuromuscular disease were studied and were found to be thin, hypomineralized, and elongated. In most of the bones, there were multiple diaphyseal or metaphyseal fractures, or both. By light microscopy, the outstanding findings were fractures through the growth plate and diaphysis and thinning of the cortices. The etiology of the fractures and the insufficient substance of the bone is the reduction in the intrauterine motion of the fetus, which leads to fragility of the bones and contractures of the joints. The severity of the alterations may have been related to the time of the onset of the abnormalities and to the duration and degree of the intrauterine akinesia.

Testicular microlithiasis in 2 children with bilateral cryptorchidism.

Testicular microlithiasis, associated with bilateral cryptorchidism, is studied in 2, 6-year-old children. In case 1 autopsy revealed that 60 per cent of the seminiferous tubules contained completely calcified microliths. Similar mineralized concretions also were found in different areas of the cerebrum and cerebellum. In the testicular biopsy obtained from case 2, 30 per cent of the seminiferous tubules contained microliths showing different degrees of calcification. The study of such calcifications supports the hypothesis that the mineralization process occurs according to the following stages: 1) accumulation of cellular debris in the tubular lumen, 2) deposit of concentric rings of glycoprotein material surrounding the central core and 3) calcification of the glycoprotein lamellar material. The presence of similar concretion in the nervous system as well as the lung in other reported cases suggests that microlithiasis could be a systemic disease.

The p38 transduction pathway in prostatic neoplasia

It has been proposed that, among other cellular responses, TNF‐α induces not only cell death, but also cell proliferation by activation of p38. It has also been reported that IL‐1‐α favours cell proliferation by p38 activation. The aim of the present study was to evaluate upstream (α‐PAK, MEK‐6) and downstream (Elk‐1 and ATF‐2) components of the p38 transduction pathway in normal prostate, benign prostatic hyperplasia (BPH), and prostate carcinoma (PC). Immunohistochemical and western blot analyses were performed in 20 samples of normal prostate, 47 samples of BPH, and 27 samples of PC. In all normal prostates, immunoreactivity for p‐Elk‐1 and p‐ATF‐2 was observed in epithelial cell nuclei, but no expression of α‐PAK or MEK‐6. In BPH, there was expression of α‐PAK (cytoplasm) and MEK‐6 (cytoplasm), while the proportions of lesions that were immunoreactive for p‐Elk‐1 (nucleus and cytoplasm) and p‐ATF‐2 (nucleus) decreased. In PC, the percentages of cells that were immunoreactive for α‐PAK (cytoplasm) or MEK‐6 (cytoplasm) rose slightly in comparison with BPH, while the percentages of cells that were immunoreactive for p‐Elk‐1 (nucleus and cytoplasm) or p‐ATF‐2 (nucleus and cytoplasm) were much higher than in BPH. It is concluded that overexpression of α‐PAK, MEK‐6, p38, p‐Elk‐1, and p‐ATF‐2 in BPH, and more intensely in PC, enhances cell proliferation. In BPH, such proliferation is triggered by IL‐1 and in part counteracted by the TNF‐α/AP‐1 pathway, which promotes apoptosis. In PC, proliferation is triggered by IL‐1 and TNF‐α (the TNF‐α/AP‐1 pathway is diverted towards p38 activation). Since in a study of the same patients immunoexpression of IL‐1α and IL‐1RI was previously observed to be increased in PC, inhibition of p38 is a possible target for PC treatment, as this inhibition would both decrease IL‐1‐induced cell proliferation and increase TNF‐α‐induced cell death. Copyright

Hyperplasia and the immature appearance of sertoli cells in primary testicular disorders

Testicular biopsy specimens from adult patients affected with cryptorchidism, Klinefelters syndrome, and Del Castillos syndrome were examined by light and electron microscopy. The study revealed a high proportion of testes showing seminiferous tubules with hyperplasia of Sertoli cells (from 25 to 45 cells per transverse tubular section). These cells had an immature appearance and showed a pseudostratified distribution. The nucleus was round to ovoid and regular in outline, with a smaller nucleolus than that of mature Sertoli cells. The cytoplasm showed less development of the endoplasmic reticulum as well as of the secondary lysosomes and lipid droplets than that in mature Sertoli cells. Characteristic features of these immature Sertoli cells were abundant cytoplasmic microfilaments, elaborate interdigitations between adjacent cells, and extensive tight junctions, from basement membrane to lumen. In the cryptorchid testes, a more immature Sertoli cell was found to constitute the majority of the cells in hypoplastic zones. In Klinefelters and Del Castillos syndromes as well as in cryptorchid testes to a lesser degree, a transitional type of cell-from immature to mature-was also observed. These observations suggest that Sertoli cells in these primary testicular disorders reflect a congenital deficiency producing abnormal development.

Immunohistochemical analysis of the IL-6 family of cytokines and their receptors in benign, hyperplasic, and malignant human prostate

Interleukin‐6 (IL‐6) and its receptor have been implicated in prostate cancer progression. Because other members of the IL‐6 family such as leukaemia inhibitory factor (LIF) and oncostatin M (OSM) share gp130, the signal transduction subunit of their receptors, interpretation of the data without considering the expression of these cytokines and their specific receptor subunits could be misleading. The immunohistochemical pattern of the IL‐6 family and their receptor subunits in normal prostate, benign prostatic hyperplasia (BPH), and prostatic carcinoma (PC) was investigated. In normal prostates, gp130 and OSMRα were detected exclusively in the stroma and LIFRβ was very scarce. While IL‐6 was scarcely immunolocalized to the basal cells of the epithelium, OSM was detected in the stroma and LIF in both the epithelium and the stroma. This suggests an autocrine role for this family of cytokines in the stroma of normal prostates. In BPH, gp130 and OSMRα were detected both in the epithelium and in the stroma, whereas LIFRβ was localized only to the epithelium. IL‐6 localized preferentially to the epithelium, OSM to the stroma, and LIF to both compartments. Therefore, in addition to the autocrine role in the stroma, IL‐6 and OSM may play a paracrine role from the stroma to the epithelium in BPH. In PC, gp130 and OSMRα were detected both in the epithelium and in the stroma, increasing with rising Gleason grade, whereas LIFRβ was localized exclusively to the epithelium of low Gleason grade carcinomas. IL‐6, LIF, and OSM localized in all cell types, with immunostaining increasing with Gleason grade. These data suggest an autocrine role for these cytokines in the epithelial cells of PC. The distinct pattern of expression of LIFRβ exclusively in low Gleason grade carcinomas makes LIFRβ a candidate for malignancy diagnosis. The role of OSM mainly in high Gleason grade carcinomas makes OSM a putative target for prostate cancer therapy. Copyright

Nestin, a neuroectodermal stem cell marker molecule, is expressed in Leydig cells of the human testis and in some specific cell types from human testicular tumours.

The intermediate filament protein nestin is predominantly expressed in some stem/progenitor cells and appears to be a useful molecular tool to characterise tumours originating from precursor cells of neuroectodermal and mesenchymal lineages. Leydig cells originate in the adult testis by differentiation from stem cells and express a variety of neural and neuroendocrine markers. The possible expression of the neural stem cell marker nestin in Leydig cells and testicular tumour cells was determined by analysing the patterns of nestin expression in normal and pathological human testes by Western blot and immunohistochemical methods. In normal testis, nestin was found in some vascular endothelial cells, a subset of peritubular spindle-shaped cells and some Leydig cells; spermatogenic and Sertoli cells were unstained. In normal Leydig cells, nestin was distributed in the perinuclear cytoplasm and accumulated in the crystalloids of Reinke with ageing. In non-tumour pathologies (cryptorchidism, impaired spermatogenesis), the seminiferous tubules were immunonegative, whereas hyperplastic Leydig cells showed cytoplasmic immunolabelling. In testicular malignancies, nestin was localised in the Sertoli cells of the seminiferous tubules affected with intratubular germ cell neoplasia, in the hyperplastic Leydig cells associated with these tumours and in some components (mesenchymal and neuroepithelial cells) of teratomas; spermatocytic and non-spermatocytic seminomas were unstained. Some vascular endothelial cells were immunolabelled in all tumour samples. Thus, nestin is expressed in a population of normal and hyperplastic Leydig cells and in Sertoli cells in the presence of intratubular germ-cell neoplasia. Nestin may be a good marker for identifying components of testicular teratomas.

A quantitative morphological study of human Leydig cells from birth to adulthood

SummaryHuman testicular specimens were obtained from biopsies and autopsies covering the period from birth to adulthood. The number of testosterone-containing Leydig cells was determined using the peroxidase-anti-peroxidase method. This number decreased markedly from 3–6 months of age to the end of the first year of life and, up to 6 years of age, only a small number of testosterone-containing cells was found. From 6 years onwards the number of Leydig cells progressively increased. Ultrastructural examination revealed four types of Leydig cells: (1) fetal-type Leydig cells (from birth to 1 year of age) with round nuclei, abundant smooth endoplasmic reticulum and mitochondria with tubular cristae; (2) infantile-type Leydig cells (from birth to 8–10 years of age), showing a multilobated nucleus, moderately abundant smooth endoplasmic reticulum, some lipid droplets and mitochondria with parallel cristae; (3) prepubertal, partially differentiated Leydig cells (from 6 years of age onwards) with regularly-outlined round nuclei, abundant smooth endoplasmic reticulum, mitochondria with tubular cristae, and some lipid droplets and lipofuscin granules; and (4) mature adult Leydig cells (from 8–10 years of age onwards). The ultrastructure of the infantile-type Leydig cells and the lack of delay between the disappearance of the fetal-type Leydig cells and the appearance of infantile-type Leydig cells suggest that fetal-type Leydig cells give rise to the infantile-type Leydig cells. Before puberty, myofibroblast-like precursor cells differentiate into the prepubertal, partially differentiated Leydig cells, which complete their differentiation into the adult Leydig cells.

Mast Cells in the Human Testis and Epididymis from Birth to Adulthood

Mast cells are a constant cell-type in the connective tissues of the human testis and epididymis from birth to adulthood. Ultrastructural study shows that these cells are similar to those found in other connective tissues. Histometric studies revealed that the number of mast cells in the interstitium, mediastinum and albuginea of the testis as well as in the epididymal connective tissue increases slightly during infancy, decreases during childhood, and then increases again at puberty. Increases at puberty are particularly evident in both the testicular interstitium and the epididymis. During adulthood, the number of mast cells progressively decreases in all testicular and epididymal connective tissues. Changes in mast cell number may be related to changes observed in the development of testicular connective tissue which occurs primarily during infancy and puberty.

Interleukin-1 (IL-1α and IL-1β) and its receptors (IL-1RI, IL-1RII, and IL-1Ra) in prostate carcinoma

The principal components of the interleukin‐1 (IL‐1) family are two secreted factors (IL‐1α and IL‐1β), two transmembrane receptors (IL‐1RI [biologically active] and IL‐1RII [inert receptor]), and a natural antagonist receptor of IL‐1 function (IL‐1Ra). Changes in the expression pattern of these IL‐1 members have been reported to be related to disease progression. The objective of the current study was to evaluate these changes in prostatic tissue by means of immunohistochemistry and Western blot analysis.