Hematopoiesis in aged female mice devoid of thyroid hormone receptors.

Hypothyroidism is often associated with anemia and immunological disorders. Similar defects are found in patients and in mice with a mutated dominant-negative thyroid hormone receptor α (TRα) and in knockout mice devoid of this receptor, suggesting that this isoform is responsible for the effects of the thyroid hormones in hematopoiesis. However, the hematological phenotype of mice lacking also TRß has not yet been examined. We show here that TRα1/TRß-knockout female mice, lacking all known thyroid hormone receptors with capacity to bind thyroid hormones, do not have overt anemia and in contrast with hypothyroid mice do not present reduced Gata1 or Hif1 gene expression. Similar to that found in hypothyroidism or TRα deficiency during the juvenile period, the B-cell population is reduced in the spleen and bone marrow of ageing TRα1/TRß-knockout mice, suggesting that TRß does not play a major role in B-cell development. However, splenic hypotrophy is more marked in hypothyroid mice than in TRα1/TRß-knockout mice and the splenic population of T-lymphocytes is not significantly impaired in these mice in contrast with the reduction found in hypothyroidism. Our results show that the overall hematopoietic phenotype of the TRα1/TRß-knockout mice is milder than that found in the absence of hormone. Although other mechanism/s cannot be ruled out, our results suggest that the unoccupied TRs could have a negative effect on hematopoiesis, likely secondary to repression of hematopoietic gene expression.

Benzylamine and Thenylamine Derived Drugs Induce Apoptosis and Reduce Proliferation, Migration and Metastasis Formation in Melanoma Cells.

Melanomas are heterogeneous and aggressive tumors, and one of the worse in prognosis. Melanoma subtypes follow distinct pathways until terminal oncogenic transformation. Here, we have evaluated a series of molecules that exhibit potent cytotoxic effects over the murine and human melanoma cell lines B16F10 and MalMe-3M, respectively, both ex vivo and in animals carrying these melanoma cells. Ex vivo mechanistic studies on molecular targets involved in melanoma growth, migration and viability were evaluated in cultured cells treated with these drugs which exhibited potent proapoptotic and cytotoxic effects and reduced cell migration. These drugs altered the Wnt/ß-catenin pathway, which is important for the oncogenic phenotype of melanoma cells. In in vivo experiments, male C57BL/6 or nude mice were injected with melanoma cells that rapidly expanded in these animals and, in some cases were able to form metastasis in lungs. Treatment with anti-tumor drugs derived from benzylamine and 2-thiophenemethylamine (F10503LO1 and related compounds) significantly attenuated tumor growth, impaired cell migration, and reduced the metastatic activity. Several protocols of administration were applied, all of them leading to significant reduction in the tumor size and enhanced animal survival. Tumor cells carrying a luciferase transgene allowed a time-dependent study on the progression of the tumor. Molecular analysis of the pathways modified by F10503LO1 and related compounds defined the main relevant targets for tumor regression: the activation of pro-apoptotic and anti-proliferative routes. These data might provide the proof-of-principle and rationale for its further clinical evaluation.

Liver Growth Factor (LGF) Upregulates Frataxin Protein Expression and Reduces Oxidative Stress in Friedreich's Ataxia Transgenic Mice.

Friedreich's ataxia (FA) is a severe disorder with autosomal recessive inheritance that is caused by the abnormal expansion of GAA repeat in intron 1 of FRDA gen. This alteration leads to a partial silencing of frataxin transcription, causing a multisystem disorder disease that includes neurological and non-neurological damage. Recent studies have proven the effectiveness of neurotrophic factors in a number of neurodegenerative diseases. Therefore, we intend to determine if liver growth factor (LGF), which has a demonstrated antioxidant and neuroprotective capability, could be a useful therapy for FA. To investigate the potential therapeutic activity of LGF we used transgenic mice of the FXNtm1MknTg (FXN)YG8Pook strain. In these mice, intraperitoneal administration of LGF (1.6 µg/mouse) exerted a neuroprotective effect on neurons of the lumbar spinal cord and improved cardiac hypertrophy. Both events could be the consequence of the increment in frataxin expression induced by LGF in spinal cord (1.34-fold) and heart (1.2-fold). LGF also upregulated by 2.6-fold mitochondrial chain complex IV expression in spinal cord, while in skeletal muscle it reduced the relation oxidized glutathione/reduced glutathione. Since LGF partially restores motor coordination, we propose LGF as a novel factor that may be useful in the treatment of FA.

The nuclear corepressor 1 and the thyroid hormone receptor ß suppress breast tumor lymphangiogenesis.

Vascular Endotelial Growth Factors C and D (VEGF-C and VEGF-D) are crucial regulators of lymphangiogenesis, a main event in the metastatic spread of breast cancer tumors. Although inhibition of lymphangiogenic gene expression might be a useful therapeutic strategy to restrict the progression of cancer, the factors involved in the transcriptional repression of these genes are still unknown. We have previously shown that Nuclear Receptor Corepressor 1 (NCoR) and the thyroid hormone receptor ß1 (TRß) inhibit tumor invasion. Here we show that these molecules repress VEGF-C and VEGF-D gene transcription in breast cancer cells, reducing lymphatic vessel density and sentinel lymph node invasion in tumor xenografts. The clinical significance of these results is stressed by the finding that NCoR and TRß transcripts correlate negatively with those of the lymphangiogenic genes and the lymphatic vessel marker LYVE-1 in human breast tumors. Our results point to the use of NCoR and TRß as potential biomarkers for diagnosis or prognosis in breast cancer and suggest that further studies of these molecules as potential targets for anti-lymphangiogenic therapy are warranted.

The Thyroid Hormone Receptors Inhibit Hepatic Interleukin-6 Signaling During Endotoxemia.

Decreased thyroidal hormone production is found during lipopolysaccharide (LPS)-induced endotoxic shock in animals as well as in critically ill patients. Here we studied the role of the thyroid hormone receptors (TRs) in activation of STAT3, NF-κB and ERK, which play a key role in the response to inflammatory cytokines during sepsis. TR knockout mice showed down-regulation of hepatic inflammatory mediators, including interleukin 6 (IL-6) in response to LPS. Paradoxically, STAT3 and ERK activity were higher, suggesting that TRs could act as endogenous repressors of these pathways. Furthermore, hyperthyroidism increased cytokine production and mortality in response to LPS, despite decreasing hepatic STAT3 and ERK activity. This suggested that TRs could directly repress the response of the cells to inflammatory mediators. Indeed, we found that the thyroid hormone T3 suppresses IL-6 signalling in macrophages and hepatocarcinoma cells, inhibiting STAT3 activation. Consequently, the hormone strongly antagonizes IL-6-stimulated gene transcription, reducing STAT3 recruitment and histone acetylation at IL-6 target promoters. In conclusion, TRs are potent regulators of inflammatory responses and immune homeostasis during sepsis. Reduced responses to IL-6 should serve as a negative feedback mechanism for preventing deleterious effects of excessive hormone signaling during infections.

Autoregulatory loop of nuclear corepressor 1 expression controls invasion, tumor growth, and metastasis.

Nuclear corepressor 1 (NCoR) associates with nuclear receptors and other transcription factors leading to transcriptional repression. We show here that NCoR depletion enhances cancer cell invasion and increases tumor growth and metastatic potential in nude mice. These changes are related to repressed transcription of genes associated with increased metastasis and poor prognosis in patients. Strikingly, transient NCoR silencing leads to heterochromatinization and stable silencing of the NCoR gene, suggesting that NCoR loss can be propagated, contributing to tumor progression even in the absence of NCoR gene mutations. Down-regulation of the thyroid hormone receptor ß1 (TRß) appears to be associated with cancer onset and progression. We found that expression of TRß increases NCoR levels and that this induction is essential in mediating inhibition of tumor growth and metastasis by this receptor. Moreover, NCoR is down-regulated in human hepatocarcinomas and in the more aggressive breast cancer tumors, and its expression correlates positively with that of TRß. These data provide a molecular basis for the anticancer actions of this corepressor and identify NCoR as a potential molecular target for development of novel cancer therapies.

NOD1 receptor is up-regulated in diabetic human and murine myocardium.

Type 2 diabetes has a complex pathology that involves a chronic inflammatory state. Emerging evidence suggests a link between the innate immune system receptor NOD1 (nucleotide-binding and oligomerization domain 1) and the pathogenesis of diabetes, in monocytes and hepatic and adipose tissues. The aim of the present study was to assess the role of NOD1 in the progression of diabetic cardiomyopathy. We have measured NOD1 protein in cardiac tissue from Type 2 diabetic (db) mice. Heart and isolated cardiomyocytes from db mice revealed a significant increase in NOD1, together with an up-regulation of nuclear factor κB (NF-κB) and increased apoptosis. Heart tissue also exhibited an enhanced expression of pro-inflammatory cytokines. Selective NOD1 activation with C12-γ-D-glutamyl-m-diaminopimelic acid (iEDAP) resulted in an increased NF-κB activation and apoptosis, demonstrating the involvement of NOD1 both in wild-type and db mice. Moreover, HL-1 cardiomyocytes exposed to elevated concentrations of glucose plus palmitate displayed an enhanced NF-κB activity and apoptotic profile, which was prevented by silencing of NOD1 expression. To address this issue in human pathology, NOD1 expression was evaluated in myocardium obtained from patients with Type 2 diabetes (T2DMH) and from normoglycaemic individuals without cardiovascular histories (NH). We have found that NOD1 was expressed in both NH and T2DMH; however, NOD1 expression was significantly pronounced in T2DMH. Furthermore, both the pro-inflammatory cytokine tumour necrosis factor α (TNF-α) and the apoptosis mediator caspase-3 were up-regulated in T2DMH samples. Taken together, our results define an active role for NOD1 in the heightened inflammatory environment associated with both experimental and human diabetic cardiac disease.

Efecto de la maca peruana (lepidium meyenii) y de la melatonina sobre el desarrollo testicular del ratón expuesto a hipoxia hipobárica continua / Effect of peruvian maca (lepidium meyenii) and melatonin on testicular development of mice exposed to continuous hypobaric hypoxia

El estudio de la hipoxia hipobárica (HH) determina un problema de salud pública y laboral en poblaciones que habitan en zonas de altura. La disminución del oxígeno afecta a diferentes órganos, incluyendo el testículo. El organismo responde frente a la hipoxia estimulando la angiogénesis, el flujo sanguíneo testicular e incrementa la temperatura intraescrotal, lo cual produce un daño de la espermatogénesis. Nuestro estudio valoró el efecto que produce la HH sobre el testículo del ratón. Se utilizó una cámara hipobárica regulada a 4.200 metros sobre el nivel del mar (msnm), en periodos de hipoxia durante 8,3; 16,6 y 24,9 días, en comparación a un grupo control en normoxia (500 msnm). En estos tres grupos, a unos ratones se administró melatonina, a otros maca (Lepidium meyenii) y a otros la combinación de melatonina y maca. Los objetivos fueron evaluar si la ingesta de maca protege al testículo, reduciendo el daño generado por la hipoxia, y determinar un posible efecto sinérgico de la melatonina y de la maca. La exposición a HH continua produjo una disminución del diámetro de los túbulos seminíferos y del lumen tubular; además, el seminograma demostró una reducción del recuento espermático, un aumento de la teratozoospermia y una reducción de la calidad del ADN espermático. La administración de maca aislada o la combinación de maca y melatonina en animales sometidos a HH produjo una notable mejoría de los parámetros relacionados con la función de los espermatozoides, siendo significativos la disminución del número de espermatozoides con morfología anormal y de la compactación del DNA, alcanzando en algunos casos valores próximos a los de los animales normóxicos. Los datos del presente modelo de HH corroboran los excelentes beneficios que la ingesta de maca tiene sobre la capacidad reproductiva de poblaciones que viven en áreas geográficas de grandes alturas.

Hypobaric hypoxia (HH) is a decisive factor in human health in populations that reside at high altitude levels. Low oxygen rate affects most tissues and organs, including the testis. In humans, hypoxia stimulates angiogenesis, testicular blood flow and increases intrascrotal temperature which determines negative effects on sperm production. Our study researched the effects of HH in mice testicle. Mice were housed in a hypobaric chamber with a setting at 4,200 m above sea level during three different periods of hypoxia (8.3, 16.6 and 24.9 days). Control groups were housed at normoxic conditions (500 m above sea level). Hypoxic mice were treated with melatonin, maca plant (Lepidium meyenii) and melatonin and maca combination. The aim of present study was to determine if maca consumption protects testis against harmful effects of hypoxia and to determine a possible synergistic effect between melatonin and maca administration. In this article we have demonstrated that hypoxia produces a considerable decrease of seminiferous tubules diameter and lumen diameter. Moreover, seminogram showed a reduced sperm count, increased teratozoospermia and a reduction of DNA quality. The HH mice treatment with maca or maca-melatonin combination showed statistically significant improvement at sperm function parameters, and in the reduction of sperm morphology abnormalities and DNA compaction, in some cases attaining rates closer to those registered in normoxic mice. Our experimental data corroborates that maca consumption improves reproductive capacity of populations that inhabit high altitude regions.

Sterile inflammation in acetaminophen-induced liver injury is mediated by Cot/tpl2.

Cot/tpl2 (MAP3K8) activates MKK1/2-Erk1/2 following stimulation of the Toll-like/IL-1 receptor superfamily. Here, we investigated the role of Cot/tpl2 in sterile inflammation and drug-induced liver toxicity. Cot/tpl2 KO mice exhibited reduced hepatic injury after acetaminophen challenge, as evidenced by decreased serum levels of both alanine and aspartate aminotransferases, decreased hepatic necrosis, and increased survival relative to Wt mice. Serum levels of both alanine and aspartate aminotransferases were also lower after intraperitoneal injection of acetaminophen in mice expressing an inactive form of Cot/tpl2 compared with Wt mice, suggesting that Cot/tpl2 activity contributes to acetaminophen-induced liver injury. Furthermore, Cot/tpl2 deficiency reduced neutrophil and macrophage infiltration in the liver of mice treated with acetaminophen, as well as their hepatic and systemic levels of IL-1α. Intraperitoneal injection of damage-associated molecular patterns from necrotic hepatocytes also impaired the recruitment of leukocytes and decreased the levels of several cytokines in the peritoneal cavity in Cot/tpl2 KO mice compared with Wt counterparts. Moreover, similar activation profiles of intracellular pathways were observed in Wt macrophages stimulated with Wt or Cot/tpl2 KO damage-associated molecular patterns. However, upon stimulation with damage-associated molecular patterns, the activation of Erk1/2 and JNK was deficient in Cot/tpl2 KO macrophages compared with their Wt counterparts; an effect accompanied by weaker release of several cytokines, including IL-1α, an important component in the development of sterile inflammation. Taken together, these findings indicate that Cot/tpl2 contributes to acetaminophen-induced liver injury, providing some insight into the underlying molecular mechanisms.

Bladder autoaugmentation with protective autologous uterine flap. Experimental study in the rat.

INTRODUCTION: Enterocystoplasties are associated to complications. We developed a surgical technique for bladder autoaugmentation using autologous uterine flap in the rat, to try and improve the post-surgical evolution. METHODS: 36 female Wistar rats were randomly allocated into following groups: Group 1: Control (n = 12) for analytical parameters, Group 2: Sham-operation hysterocystorrhaphy (n = 12) and Group 3: Bladder autoaugmentation with autologous uterine flap (n = 12). Two weeks after surgery ultrasound examination of the bladder was performed. At 8 weeks and 24 weeks, blood and urine samples were taken. Post-mortem evaluation was performed and urogenital apparatus removed for gross and microscopic examination. The statistical analysis was done using the Kruskall-Wallis and the extension of the Fisher's exact test. Significance was set at 5% (p < 0.05). RESULTS: Serum chemistry, blood count and peripheral blood smears, electrolytes and urinary parameters were all within the normal range for the rat. No abnormal findings were observed during ultrasound examination. There was no mortality or other surgical complications. Post-mortem evaluation revealed no dilation of bladder, uterus or upper urinary tract. Uroliths were not observed. Histology of the augmented area demonstrated an excellent union between the bladder and the protective uterine flap. A normal urothelial layer was maintained. CONCLUSIONS: The use of autologous uterine flap to perform bladder autoaugmentation in the rat proved a safe and suitable surgical technique to augment the bladder. The major advantage is the avoidance of the complications observed in other surgical techniques for bladder augmentation, like enterocystoplasties, where gastrointestinal tract epithelium is incorporated into the urinary tract.

Histerocystoplasty: a novel surgical procedure in the rat.

BACKGROUND: Enterocystoplasties are associated to complications. To avoid them, different types of tissue templates have been used to augment the bladder and induce native bladder regeneration. MATERIALS AND METHODS: A novel surgical technique for bladder reconstruction using autologous uterine tissue was evaluated in a rat model. Forty-two female Wistar rats were randomly allocated into three groups: sham-operation hysterocystorrhaphy (n = 12), hysterocystoplasty (n = 18), and control (n = 12). Two weeks after surgery, ultrasound examination of the bladder was performed. At 2, 4, or 6 mo after surgery, the rats were anesthetized and blood and urine samples were taken. They were then euthanized and post-mortem and histologic examination were performed. Ultrasound examination, analytical parameters and weight control, as well as gross and histologic examination were performed in all the operated animals. The statistical analysis was performed using Kruskal-Wallis and the extension of Fisher's exact tests. Significance was set at 5% (P < 0.05). RESULTS: Serum chemistry, blood count and peripheral blood smears, electrolytes, and urinary parameters were all within the normal range for the rat. Histologic sections of the surgically augmented zone between the bladder and uterine horn demonstrated urothelial epithelization, providing adequate coverage of the transition area in 72.22% of the rats that underwent hysterocystoplasty. CONCLUSIONS: The hysterocystoplasty was technically viable in all the cases and proved to be an easy and safe surgical model for bladder reconstruction. All animals were healthy after surgery and all systemic parameters analyzed were within normal physiologic range for the rat.

Short and long term fate of human AMSC subcutaneously injected in mice.

AIM: To study the ability of human adipose-derived mesenchymal stem cells (AMSCs) to survive over the short and long term, their biodistribution and their biosafety in vivo in tumor-prone environments. METHODS: We subcutaneously injected human AMSCs from different human donors into immunodeficient SCID mice over both short- (2 and 4 mo) and long- (17 mo) term in young, and aged tumor-prone mice. Presence of human cells was studied by immunohistochemistry and polymerase chain reaction analysis in all organs of injected mice. RESULTS: Subcutaneously injected AMSCs did not form teratomas at any time point. They did not migrate but remained at the site of injection regardless of animal age, and did not fuse with host cells in any organ examined. AMSCs survived in vivo for at least 17 mo after injection, and differentiated into fibroblasts of the subdermic connective tissue and into mature adipocytes of fat tissue, exclusively at the site of injection. CONCLUSION: Our results support the assertion that AMSC may be safe candidates for therapy when injected subcutaneously because of their long term inability to form teratomas.

The thyroid hormone receptors as tumor suppressors.

In addition to the well-known role of the thyroid hormone receptors (TRs) in growth, development and metabolism, there is increasing evidence that they have profound effects on cell proliferation and malignant transformation. TRs repress transcriptional induction of cyclin D1 by the ras oncogene and block transformation and tumor formation by Ras-transformed fibroblasts in nude mice. Mutant receptors that do not bind coactivators are able to display these actions, whereas receptors defective in corepressors binding are unable to antagonize the responses to the ras oncogene. Furthermore, expression of TRß1 in hepatocarcinoma and breast cancer cells abolishes anchorage-independent growth and migration, blocks responses to growth factors and represses expression of prometastatic genes, reducing tumor growth and strongly inhibiting invasiveness, extravasation and metastasis formation in euthyroid mice. By contrast, when cells are inoculated into hypothyroid host, tumor growth is retarded, but tumors are more invasive and metastatic growth is enhanced. Increased aggressiveness and tumor growth retardation was also observed with parental cells that do not express TRs, showing that changes secondary to hypothyroidism can modulate tumor progression and metastatic growth independently of the presence of TRs on the tumor cells. Finally, increased malignancy of skin tumors is found in mice lacking TRs, further demonstrating the role of these receptors as inhibitors of tumor progression and suggesting that they represent a potential therapeutic target in cancer.

Cot/tpl2 (MAP3K8) mediates myeloperoxidase activity and hypernociception following peripheral inflammation.

Cot/tpl2 (also known as MAP3K8) has emerged as a new and potentially interesting therapeutic anti-inflammatory target. Here, we report the first study of Cot/tpl2 involvement in acute peripheral inflammation in vivo. Six hours after an intraplantar injection of zymosan, Cot/tpl2(-/-) mice showed a 47% reduction in myeloperoxidase activity, concomitant with a 46% lower neutrophil recruitment and a 40% decreased luminol-mediated bioluminescence imaging in vivo. Accordingly, Cot/tpl2 deficiency provoked a 25-30% reduction in luminol-mediated bioluminescence and neutrophil recruitment together with a 65% lower macrophage recruitment 4 h following zymosan-induced peritonitis. Significantly impaired levels of G-CSF and GM-CSF and of other cytokines such as TNFα, IL-1ß, and IL-6, as well as some chemokines such as MCP-1, MIP-1ß, and keratinocyte-derived chemokine, were detected during the acute zymosan-induced intraplantar inflammatory response in Cot/tpl2(-/-) mice. Moreover, Cot/tpl2 deficiency dramatically decreased the production of the hypernociceptive ligand NGF at the inflammatory site during the course of inflammation. Most importantly, Cot/tpl2 deficiency significantly reduced zymosan-induced inflammatory hypernociception in mice, with a most pronounced effect of a 50% decrease compared with wild type (WT) at 24 h following intraplantar injection of zymosan. At this time, Cot/tpl2(-/-) mice showed significantly reduced NGF, TNFα, and prostaglandin E(2) levels compared with WT littermates. In conclusion, our study demonstrates an important role of Cot/tpl2 in the NGF, G-CSF, and GM-CSF production and myeloperoxidase activity in the acute inflammatory response process and its implication in inflammatory hypernociception.

Hypothyroidism enhances tumor invasiveness and metastasis development.

BACKGROUND: Whereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development, the relationship between thyroid hormone levels and human cancer is a controversial issue. It has been reported that hypothyroidism might be a possible risk factor for liver and breast cancer in humans, but a lower incidence of breast carcinoma has been also reported in hypothyroid patients METHODOLOGY/PRINCIPAL FINDINGS: In this work we have analyzed the influence of hypothyroidism on tumor progression and metastasis development using xenografts of parental and TRbeta1-expressing human hepatocarcinoma (SK-hep1) and breast cancer cells (MDA-MB-468). In agreement with our previous observations tumor invasiveness and metastasis formation was strongly repressed when TRbeta-expressing cells were injected into euthyroid nude mice. Whereas tumor growth was retarded when cells were inoculated into hypothyroid hosts, tumors had a more mesenchymal phenotype, were more invasive and metastatic growth was enhanced. Increased aggressiveness and tumor growth retardation was also observed with parental cells that do not express TRs. CONCLUSIONS/SIGNIFICANCE: These results show that changes in the stromal cells secondary to host hypothyroidism can modulate tumor progression and metastatic growth independently of the presence of TRs on the tumor cells. On the other hand, the finding that hypothyroidism can affect differentially tumor growth and invasiveness can contribute to the explanation of the confounding reports on the influence of thyroidal status in human cancer.

Thyroid hormone receptor beta1 acts as a potent suppressor of tumor invasiveness and metastasis.

Loss of thyroid hormone receptors (TR) is a common feature in some tumors, although their role in tumor progression is currently unknown. We show here that expression of TRbeta1 in hepatocarcinoma and breast cancer cells reduces tumor growth, causes partial mesenchymal-to-epithelial cell transition, and has a striking inhibitory effect on invasiveness, extravasation, and metastasis formation in mice. In cultured cells, TRbeta1 abolishes anchorage-independent growth and migration, blocks responses to epidermal growth factor, insulin-like growth factor-I, and transforming growth factor beta, and regulates expression of genes that play a key role in tumorigenicity and metastatic growth. The receptor disrupts the mitogenic action of growth factors by suppressing activation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling pathways that are crucial for cell proliferation and invasiveness. Furthermore, increased aggressiveness of skin tumors is found in genetically modified mice lacking TRs, further demonstrating the role of these receptors as inhibitors of tumor progression. These results define a novel role for the thyroid hormone receptor as a metastasis suppressor gene, providing a starting point for the development of novel therapeutic strategies for the treatment of human cancer.

[Photodynamic therapy in urology. Biologic and pathologic mechanisms of action]. / La terapia fotodinámica en urologia. Mecanismos de acción biológicos y patológicos.

Photodynamic Therapy (FDT) is a minimally invasive therapeutic modality extraordinarily useful. In urology, FDT is very useful and may be applied through endoscopes or directly, with excellent results obtained for the diagnosis and treatment of bladder tumors, in the treatment of prostate cancer and its recurrences, and in the treatment of dermatological premalignant lesions and carcinomas of the penis. FDT is founded on the use of photosensitizing products which selectively accumulate in tumor tissues. The irradiation of these tissues with a proper wavelength light (generally in the red region of the visible spectrum lambda > or = 600 nm) produces the formation of oxygen reactive species with cytotoxic effects leading to selective death of neoplastic cells, and tumor regression. The main advantage of FDT is the restriction of cellular damage to the irradiation area, with the associated decrease of secondary effects on healthy tissues near the tumor, on the contrary to what happen with other conventional therapies for some tumors of the urinary tract. Moreover, FDT may be used in combination with radiotherapy and chemotherapy.

Leydig cell tumor and hyperplasia: a review.

We describe the role of Leydig cells in normal, hyperplastic and neoplastic testis. Recent acquisitions on etiology and pathobiology of Leydig cell proliferations, unusual microscopic presentations and clinical and morphologic features predictive of malignancy are reported.

[Unilateral essential hematuria: diagnosis, endoscopic treatment, and new diagnostic-therapeutic algorithm]. / Hematuria esencial unilateral: diagnostico, tratamiento endoscopico y nuevo algoritmo diagnostico-terapeutico.

OBJECTIVES: To perform a long-term evaluation of 15 patients with unilateral essential hematuria, with the aim of determining the causes of bleeding and the response to endoscopic treatment. To design a diagnostic-therapeutic algorithm for patients with unilateral essential hematuria. METHODS: We retrospectively review the clinical data of 15 patients with unilateral essential hematuria evaluated by rigid ureterorenoscopy (15 cases), flexible ureteropyelocalycoscopy (15 cases) and percutaneous nephroscopy (3 cases). In 4 patients electric fulguration of the pyelocalicial lesions was carried out. RESULTS: 14 of the 15 patients were successfully treated endoscopically. Only one patient presented recurrence of the hematuria. Mean follow-up time was 64 months (4-168 months). No patient suffered any relevant complication secondary to the endoscopic treatment. CONCLUSIONS: The cause of bleeding in patients with unilateral essential hematuria is determined only in a few, but endoscopic treatment is successful in a high percentage of cases. We consider that upper urinary tract endoscopy, mainly flexible ureteropyelocalycoscopy, has strongly impacted the diagnosis and treatment of essential unilateral hematuria. We present a new diagnostic-therapeutic algorithm, based on the usefulness of flexible instrumentation.

Primary testicular lesions are associated with testicular germ cell tumors of adult men.

The present study aims to establish the nature and frequency of testicular lesions in the parenchyma adjacent to testicular germ cell tumors (TGCT) to improve understanding of the factors involved in the development of testicular cancer. Fifty-three cases of TGCT that were fixed in both neutral-buffered formalin and Bouin solution, allowing for the nuclear characterization of Sertoli cells (SCs), were included in this study. In each case, at least 3 sections of different areas of preserved parenchyma surrounding the TGCT were studied. We found Leydig cell hyperplasia, microlithiasis, angiopathy, adenomatous hyperplasia of the rete testis, SC nodules, SC dysgenesis and involution, SC-only tubules, tubular atrophy, adluminal compartment lesions, hypospermatogenesis associated with spermatocyte sloughing, spermatogonial maturation arrest, and hypertrophic and multinucleated spermatogonia. These lesions were found in regions both adjacent and far away from the tumoral mass, and abnormal seminiferous tubules were found intermingled with those showing complete spermatogenesis, suggesting that these lesions are primary and existed before the development of the tumor. Our study suggests that SCs might play a more important role in the development of testicular tumors than previously thought. Our data supports the hypothesis that there is an abnormal differentiation of SCs, caused either by genetic anomalies or by environmental agents during fetal life. This abnormal SC differentiation may cause not only primary spermatogenesis failure and spermatogenesis arrest at different levels, but may also contribute to the poor differentiation of gonocytes into spermatogonia. The abnormal gonocyte differentiation might favor the development of dysplastic germ cells that may later transform into intratubular germ cell neoplasia, unclassified type.