Stem/progenitor cells in fetuses and newborns: overview of immunohistochemical markers.

Microanatomy of the vast majority of human organs at birth is characterized by marked differences as compared to adult organs, regarding their architecture and the cell types detectable at histology. In preterm neonates, these differences are even more evident, due to the lower level of organ maturation and to ongoing cell differentiation. One of the most remarkable finding in preterm tissues is the presence of huge amounts of stem/progenitor cells in multiple organs, including kidney, brain, heart, adrenals, and lungs. In other organs, such as liver, the completely different burden of cell types in preterm infants is mainly related to the different function of the liver during gestation, mainly focused on hematopoiesis, a function that is taken by bone marrow after birth. Our preliminary studies showed that the antigens expressed by stem/progenitors differ significantly from one organ to the next. Moreover, within each developing human tissue, reactivity for different stem cell markers also changes during gestation, according with the multiple differentiation steps encountered by each progenitor during development. A better knowledge of stem/progenitor cells of preterms will allow neonatologists to boost preterm organ maturation, favoring the differentiation of the multiple cells types that characterize each organ in at term neonates.

Multimodal management of stages III-IVa malignant thymoma.

PURPOSE: The optimal therapy for locally advanced malignant thymoma is controversial. We review our experience with a multimodal approach in 63 consecutive cases. PATIENTS AND METHODS: Forty-three patients had stage III and 20 stage IVa disease. Surgery with radical intent was initially performed in 30 cases, while 33 cases not amenable to radical surgery underwent neoadjuvant treatment (radiotherapy in 8 and chemotherapy in 25) before surgical reassessment. All patients, whether or not surgically resected, received radiation therapy. RESULTS: Radical resection (RR) was performed in 20 patients ab initio (all stage III) and in 12 patients after neoadjuvant treatment (eight stage III and four stage IVa). With the addition of patients radically operated with neoadjuvant treatment, the radical resection rate increased from 46 to 65% in stage III patients, and from 0 to 20% in those with stage IVa disease, respectively. Radical surgery was associated with longer progression free survival and overall survival according to both univariate analysis ( P< 0.001 and P<0.01, respectively) and multivariate analysis after adjustment for age, gender, histology and disease stage ( P<0.001 and <0.02, respectively). Progression free survival (median 56.9 months) was slightly lower in patients undergoing radical surgery after neoadjuvant approaches than in those radically resected ab initio (median not achieved), but overall survival (median not achieved) was similar in both groups. Subtotal surgical resection promoted complete response to subsequent radiation therapy. This condition significantly correlated with a better outcome. CONCLUSIONS: Complete surgical resection is an independent prognostic parameter in locally advanced thymoma treated with a multimodal approach. Preoperative treatment to increase the complete resection rate could improve the overall survival of these patients.

Association of Maedi Visna virus with Brucella ovis infection in rams.

Maedi Visna Virus (MVV) is the etiological agent of a systemic disease of sheep, which causes lesions in lungs, the central nervous system, joints, and mammary glands. It has been speculated that the association with Brucella ovis may lead to the venereal shedding of the virus. In this work, samples of epididymis from ten rams positive for MVV and infected experimentally with Brucella ovis, were subjected to liquid-phase PCR, immunohistochemistry (IHC) and in situ PCR tests, aimed at identifying the pathogens in a tissue context. IHC was carried out using a monoclonal antibody raised against p28 MVV protein and a polyclonal antibody to B. ovis. Liquid phase- and in situ PCR were designed to amplify a portion of MVV proviral DNA Pol sequence. In the animals showing B. ovis-related histopathological changes, IHC clearly demonstrated a positivity for B. ovis and MVV in interstitial and epithelial ductal cells. In situ PCR assessed the presence of MVV proviral DNA in macrophages and elements inside the epithelium. The unaffected and reagent control samples constantly gave negative results. Taken together, these data demonstrate that MVV may affect ovine epididymis, apparently taking advantage of the concurrent infection by B. ovis. The tropism of MVV for the epididymal epithelial cells, may be responsible for its excretion with the semen.

Tissue kallikrein and bradykinin B2 receptors in the reproductive tract of the male rat.

The setting of a local tissue kallikrein kinin system (tKKS) within the reproductive organs of the male rat was investigated by analysing bradykinin subtype 2 receptor (B2R) gene expression and cellular distribution of B2R protein and the kinin-liberating protease tissue kallikrein (tK). Reverse transcription-polymerase chain reaction showed B2R expression in testis, epididymis and prostate from prepubertal and sexually mature rats. In mature testis, in situ hybridization and immunohistochemistry localized B2R mRNA and protein besides endothelial cells of blood vessels exclusively on pachytene spermatocytes and round and elongated spermatids. B2R expression within the seminiferous tubules was found to be dependent on the stage of the spermatogenic cycle. In pre-pubertal rat testis, B2R mRNA and protein were additionally located in peritubular cells. In the testis, specific staining for tK occurred in addition to endothelial cells of blood vessels on the acrosomal cap of round and elongated spermatids. This immunostaining was also stage-dependent. In the epididymis, tK was detected on epithelial cells near the apical surface. The stage-dependent specific expression of tK and bradykinin B2Rs in developing germ cells and peritubular cells suggests a potential role of the tKKS in the local regulation of spermatogenesis and seminiferous tubule function.

Endogenous jaagsiekte sheep retrovirus RNA is expressed by different cell types in ovine foetus and placenta.

The endogenous retroviruses are inherited elements transmitted trough the germline of most animal species and their biological role is still controversial. Ovine Pulmonary Carcinoma (OPC) represents a good model for studying the interactions of endogenous retroviruses with their exogenous counterparts. The type D exogenous retrovirus known as Jaagsiekte Sheep Retro-Virus (JSRV) is necessary and sufficient to cause OPC in domestic and wild sheep, but both affected and unaffected animals host in their genome 15 to 20 copies of related endogenous retroviruses named endogenous JSRV (enJSRV). In this study we evaluated the expression of enJSRV gag sequences in ovine foetal and placental tissues. RNA in situ hybridisation was performed on tissue sections of thymi, lymph nodes and lungs from ovine foetuses and related placentas, taken at a late stage of development. Reverse transcriptase-in situ polymerase chain reactions were also carried out on placental samples to better define the involved cells. In foetal tissues, specific signals were observed in the thymus medulla, lymph nodes and, at a lesser extent, in foetal bronchiolar cells. In the placental tissues, positive areas were detected in various cell types in the sincythium-and cyto-trophoblast. These data demonstrate that en JSRV RNA is largely expressed in a broad spectrum of cells including tissues which are critical for the development of the immune system.

Chromosomal abnormalities and microsatellite instability in sporadic endometrial cancer.

Defective DNA mismatch repair and nonfunctional mechanisms controlling the proper progression of the cell cycle have been proposed as being responsible for the genomic instability and accumulation of karyotypic alterations in endometrial cancer (EC). To assess whether numerical chromosomal anomalies (aneuploidy) and microsatellite instability (MSI) might be representative of distinctive tumour behaviour, paraffin-embedded tissue samples from 86 patients with sporadic EC were evaluated by both fluorescence in situ hybridisation (FISH) and microsatellite analysis, using free nuclei and genomic DNAs (respectively). Approximately one-third of the tumours analysed (24/74; 32%) exhibited MSI, whereas 38/86 (44%) of the EC samples displayed aneuploidy. The majority of the unstable cases (15/24; 63%) were from advanced-stage patients. Conversely, 23 (61%) out of the 38 tumours with aneuploidy were from early-stage patients. No apparent correlation was found between MSI and aneuploidy, whereas the immunohistochemical (IHC) analysis revealed that inactivation of the MLH1 mismatch repair gene may be involved in the majority of the MSI+ sporadic ECs. No genetic or cytogenetic alteration analysed here seems to add any significant predictive value to the stage of disease.

Gemcitabine plus cisplatin in the treatment of patients with advanced non-small cell lung cancer: a phase II study.

BACKGROUND: Lung cancer is the leading cause of cancer death in men worldwide; most cases are not suitable for radical surgery at diagnosis and palliative treatment remains the primary goal of therapy. Cisplatin and gemcitabine are among the most active cytotoxic agents for the treatment of non-small cell lung cancer (NSCLC): they have non-overlapping toxicity and preclinical studies have demonstrated their potential synergistic interaction. PATIENTS AND METHODS: The aims of the present study were to assess the activity and tolerability of cisplatin 80 mg/m2 on day 1, combined with gemcitabine 1000 mg/m2 on days 1 and 8, administered every 3 weeks. A total of 46 consecutive patients with advanced NSCLC entered this study; all of them were evaluable for toxicity and for activity. RESULTS: According to an intent-to-treat analysis, 15 patients attained a partial response (33%), 9 (20%) obtained a disease stabilisation and 22 (47%) progressed. This regimen appeared to be modestly toxic, with grades 3-4 leukopenia and thrombocytopenia observed in 10% and 6% of cases respectively; grade 3 vomiting appeared in 12 patients (26%) and grade 3 mucositis in 1 patient. The median time-to-progression and overall survival were 200 and 400 days, respectively. CONCLUSION: Our study of gemicitabine + cisplatin on stage IV NSCLC patients achieved favourable results in terms of toxicity and overall survival.

Low dose carboplatin (AUC 4.5) combined with vinorelbine in the treatment of advanced non-small cell lung cancer: a single institution phase II study.

Platinum compounds and vinorelbine (VNB) are active in the treatment of non-small cell lung cancer (NSCLC), but moderate toxicity has been reported. The aims of the present study were to assess activity and tolerability of low dose carboplatin (CBDCA): 4.5 AUC according to Calvert formula on day 1, combined with vinorelbine: 25 mg/m2 on days 1 and 8, administered every 4 weeks. Eighty-five advanced NSCLC patients entered the study; all of them were evaluable for toxicity and 83 were evaluable for activity. According to an intent to treat analysis, 26 patients attained a partial response (30.5%; 95% CI 20.5-40.5), 27 (31.7%) obtained a disease stabilization and 30 (35%) progressed. This regimen appeared to be modestly toxic, grade 3-4 leukopenia and thrombocytopenia were observed in less than 5% of cases and grade 2 neuropathy in 10% of cases. Median time to progression and overall survival were 7 and 9 months, respectively. In conclusion, low dose CBDCA (administered following Calvert's formula) and VNB combination is an active and very well tolerated cytotoxic regimen in the treatment of advanced NSCLC. The application of the Calvert formula may have contributed to limit the side effects related to CBDCA.