Activation of nervous system development genes in bone marrow derived mesenchymal stem cells following spaceflight exposure.

Stalled cell division in precursor bone cells and reduced osteoblast function are considered responsible for the microgravity-induced bone loss observed during spaceflight. However, underlying molecular mechanisms remain unraveled. Having overcome technological difficulties associated with flying cells in a space mission, we present the first report on the behavior of the potentially osteogenic murine bone marrow stromal cells (BMSC) in a 3D culture system, flown inside the KUBIK aboard space mission ISS 12S (Soyuz TMA-8 + Increment 13) from March 30 to April 8, 2006 (experiment "Stroma-2").

Osteoblast and osteoclast differentiation in an in vitro three-dimensional model of bone.

There is increasing interest in developing new in vitro tissue models using typical tissue engineering approaches. This study was designed to (1) develop a novel three-dimensional (3D) in vitro model of bone by seeding murine primary osteoblasts and osteoclast precursors on a resorbable porous ceramic scaffold based on silicon-stabilized tricalcium phosphate (Skelite), and (2) investigate bone cell interactions in a 3D environment mimicking an in vivo condition and compare it to traditional two-dimensional (2D) cultures. Murine primary osteoblasts from C57Bl6/J mice and osteoclast precursors from C57Bl/6-Tg(ACTB-EGFP)1Osb/J mice were co-cultured on 3D Skelite scaffolds and on standard plastic culture dishes.

Clonal granulocytes in polycythaemia vera and essential thrombocythaemia have shortened telomeres.

Summary The purpose of this study was to evaluate telomere length in peripheral blood granulocytes and mononuclear cells collected from 22 women with polycythaemia vera (PV) and essential thrombocythaemia (ET). PV and ET are chronic myeloproliferative diseases whose heterogeneity of stem cell origin and clonal development has been established through analysis of X-chromosome inactivation patterns. The results from clonality assay and determination of telomere length show that only clonal granulocytes have shortened telomeres.

High telomerase activity in granulocytes from clonal polycythemia vera and essential thrombocythemia.

Essential thrombocythemia (ET) and polycythemia vera (PV) are chronic myeloproliferative disorders that share the involvement of a multipotent progenitor cell and dominance of the transformed clone over normal hematopoiesis. On the other hand, the heterogeneity of these diseases with respect to clonal development from a common progenitor has been well established. To identify useful prognostic indicators, we analyzed telomerase activity (TA), a known marker of neoplastic proliferation, in granulocytes (PMNs) and mononuclear cells (MNCs) from 22 female patients with ET and PV.

Pancreatic intraductal sampling during ERCP in patients with chronic pancreatitis and pancreatic cancer: cytologic studies and k-ras-2 codon 12 molecular analysis in 47 cases.

Background: A preoperative tissue diagnosis of pancreatic cancer is desirable but difficult to obtain.

Methods: Pancreatic brush cytology, salvage cytology, and collection of pancreatic juice were attempted prospectively during ERCP in 34 patients with pancreatic cancer and 11 with chronic pancreatitis. K-ras-2 codon 12 was analyzed for presence and type of point mutations.

K-ras2 activation and genome instability increase proliferation and size of FAP adenomas.

The possible role of K-ras2 mutations and aneuploidy toward increase of proliferation and adenoma size in Familial Adenomatous Polyposis (FAP) adenomas is not known. The present study addresses these issues by investigating 147 colorectal adenomas obtained from four FAP patients. The majority of adenomas had size lower than or equal to 10 mm (86%), low grade dysplasia (63%), and were preferentially located in the right colon (60%).

Intratumor heterogeneity of K-ras2 mutations in colorectal adenocarcinomas: association with degree of DNA aneuploidy.

Detailed information about intratumor K-ras2 mutations in colorectal adenocarcinomas and a possible association with DNA content heterogeneity is still lacking. DNA diploid and aneuploid subclones, detected among multiple histologically selected primary sectors (57 superficial and 40 deep) and 9 lymph node metastases, were flow cytometrically sorted and separately submitted to codons 12-13 K-ras2 mutation spectrum analysis. DNA aneuploidy was absent among 20 near and 20 distant mucosa sites and present in 7/9 lymph node metastases and in 17/19 primary tumors (90%).

K-ras-2 G-C and G-T transversions correlate with DNA aneuploidy in colorectal adenomas.

Background/aims: K-ras-2 mutations and DNA content heterogeneity represent early events of human colorectal tumor progression. The aim of the study was to investigate if specific K-ras-2 mutations in 58 human sporadic adenomas were correlated with DNA aneuploidization and cell proliferation.

Methods: Multiparameter flow cytometry, based on scatter parameters and DNA content, was performed using 4,6-diamidino-2-phenilindole-2-hydrochloride-stained nuclei obtained from adenoma fragments with either mild-moderate or severe dysplasia.

High incidence of H-ras oncogene mutations in squamous cell carcinoma of lip vermilion.

Nine specimens of well-differentiated squamous cell carcinoma of the lip vermilion have been analyzed for the presence of H-ras oncogene mutations, using the technique of hybridization with synthetic oligonucleotide probes on in vitro amplified tumour DNA. Five specimens harbored mutations: four in codon 12 and one in codon 13. This high incidence (55%) of mutated H-ras genes suggests that their activation may play an important role in lip tumour development and may be connected to the exposure to chemical and/or physical carcinogens.

Effects of a modified CMF treatment (cyclophosphamide, methotrexate and 5-fluorouracil) on hematopoietic tissues and Yoshida sarcoma in rats.

Effects of a modified CMF treatment on hematopoietic tissue and an implanted tumor were studied in rats. The modification of the treatment refers to the application of cyclophosphamide 24 h after methotrexate and 5-fluorouracil. The study was done on Wistar rats bearing Yoshida sarcoma in the ascites form.

H-ras gene mutations in salivary gland pleomorphic adenomas.

The DNA from 17 specimens of pleomorphic adenoma of the salivary glands was screened for the presence of ras gene mutations, which are known to be involved in the pathogenesis of various human neoplasias. By a sensitive method of hybridization with synthetic oligonucleotide probes on in vitro amplified tumor DNA, point mutations, mainly in codon 12 of the H-ras gene, were detected in six tumor specimens (35%). This high incidence of mutated ras genes suggests that their alteration may play a role in the pathogenesis of pleomorphic adenomas.

DNA-ploidy analysis within selected regions of colorectal adenomas containing carcinoma.

In order to better understand the relationship of DNA ploidy, dysplasia, early cancer, and colorectal tumor progression, 11 colorectal adenomas containing carcinoma invading the submucosa were investigated using DNA flow cytometry. Multiple frozen samples were taken from the selected sectors corresponding to adenoma tissue with low-grade dysplasia, high grade dysplasia and early cancer. Sampling accuracy was performed under histologic examination by multiple cryostatic sections.

Humoral stimulating activities in post-cyclophosphamide rat sera and their purified fractions.

Enhanced humoral, stimulating activities (HSAs) of post-cyclophosphamide (CY) sera and their purified fractions, acting on mitogen activated T-lymphocytes, were detected in Wistar rats after treatment by high single doses of the aplasia producing alkylating cytostatic drug CY. These activities, monitored in vitro, were partially purified from post-CY sera, collected 2, 4, and 7 days after treatment, yielding fractions with higher humoral stimulating activity. The preliminary purification included molecular cutting by Amicon-Diaflo filters (1-30 kDa pore size range) and gel-filtration on Sephadex G-50 and G-75.

Labelling of leukocytes with 99mTc-HMPAO for scintigraphy of inflammatory lesions and abscesses.

A simplified and efficient procedure for 99mTc-HMPAO-labelling of leukocytes is described. For this purpose, the pH and concentration of the 99mTc-HMPAO preparation was modified. Leukocytes were isolated from a 20 mL mixture of patient blood, 5 mL ACD and 0.

The effect of the rat-cyclophosphamide serum on the rat hematopoietic tissue recovery, previously damaged by cyclophosphamide or by gamma-irradiation.

The effect of post-cyclophosphamide serum (post-CY serum) humoral activity in vivo, on the rat hematopoietic regeneration after damage either by cyclophosphamide (CY) or by gamma-irradiation was investigated. Three experimental groups of rats were studied. The first group was treated by a single high dose of CY (200 mg/kg), the second group was whole body irradiated by 6.