Follicle-like model by granulosa cell encapsulation in a barium alginate-protamine membrane.

Granulosa cells from bovine and porcine ovaries were cultured either in monolayer or in follicle-like barium alginate capsules for 6 days. Morphological investigation by electron scanning microscopy indicated that culture in a three-dimensional (3D) system allows self-organization of spherical-polyhedral shape cells. The luteinization index (progesterone:17beta-estradiol ratio) was significantly higher for monolayer cells than for the 3D cell culture system, confirming the results of morphological analysis and indicating more physiological growth. The encapsulated 3D culture system appears to be a promising way of obtaining in vitro maturation and development of follicles and oocytes.

beta amyloid-induced disruption of ionic balance: studies on the isolated frog labyrinth.

The beta-amyloid peptide (A beta) is a key player in the pathogenesis of Alzheimer's disease. Although its mechanisms of action are not fully elucidated, a disruption of ionic homeostasis has been suggested, and A beta aggregation in fibrils seems correlated to its toxic potential. In the present work, we studied the effects of different A beta fragments on the activity of frog ampullar nerve fibers. Our results show that A beta fragments are able to reduce ampullar nerve responses, with a potency correlated to their fibrillogenic capability. This study may have clinical implications, since vestibular problems are often reported in Alzheimer patients, and provide a model for the dissection of A beta effects in a simple multicomponent system.

CG5/Dx human breast cancer cell line: characterization of a new doxorubicin-resistant variant.

By continuous exposure of CG5 human breast cancer cell line to increasing doxorubicin (Dx) concentrations, a multidrug-resistant (MDR) subline (CG5/Dx) was obtained. The resistant variant showed P-glycoprotein (P-gp) expression and a lower intracellular doxorubicin level than the parental cells. CG5/Dx cells were 19.4 fold more resistant to Dx than CG5 cells and showed a cross-resistance to some structurally related and unrelated compounds. Differences in kinetics, biological and ultrastructural features between the two cell lines were investigated. The CG5/Dx cells grew more slowly, produced higher CEA levels and showed a reduced progesterone receptor (PgR) content than the parental cells. Ultrastructural studies revealed differences involving, polyribosomes, rough endoplasmic reticulum, [mitochondria] and cytoskeleton.

Unexpected finding of barium sulphate on the surface of a microspinal catheter.

During a study with a scanning electron microscope to evaluate the structure of microspinal catheter after its removal from subarachnoid space, we found an unusual case. The observation with the microscope of the tip of a catheter removed at the end of an operation for hip replacement in a old female showed the presence of grounded particles with a crystal shape covering the outer surface. Further analysis of this material with an Energy-Dispersive Spectrometer (EDS) showed that it was barium. The patient performed a large bowel barium enema 8 months earlier for a painful syndrome to the lower abdomen. Authors rule out the contamination from the skin and suggest two possible mechanisms of passage of barium from blood to cerebrospinal fluid (CSF) and so to the surface of the catheter.

[Hormone replacement therapy and cardiovascular diseases: different populations, different risks]. / Terapia ormonale sostitutiva e malattie cardiovascolari: popolazioni differenti, rischi differenti.

Observational studies indicate that oral hormone replacement therapy (HRT) in menopause is associated with a 20-40% reduction of coronary risk. Population risk/benefit analyses on mortality after large-scale HRT use indicate that excess deaths can be counted when coronary heart disease is relatively less frequent than breast cancer before age 60 (as occurs in Italy). The decline in mortality trends for coronary heart disease support a word for caution for a large scale use of HRT in the next years even in those populations for which a relative advantage is presently estimated.

The differentiation of human adipose-derived stem cells (hASCs) into osteoblasts is promoted by low amplitude, high frequency vibration treatment.

Several studies have demonstrated that tissue culture conditions influence the differentiation of human adipose-derived stem cells (hASCs). Recently, studies performed on SAOS-2 and bone marrow stromal cells (BMSCs) have shown the effectiveness of high frequency vibration treatment on cell differentiation to osteoblasts. The aim of this study was to evaluate the effects of low amplitude, high frequency vibrations on the differentiation of hASCs toward bone tissue. In view of this goal, hASCs were cultured in proliferative or osteogenic media and stimulated daily at 30Hz for 45min for 28days. The state of calcification of the extracellular matrix was determined using the alizarin assay, while the expression of extracellular matrix and associated mRNA was determined by ELISA assays and quantitative RT-PCR (qRT-PCR). The results showed the osteogenic effect of high frequency vibration treatment in the early stages of hASC differentiation (after 14 and 21days). On the contrary, no additional significant differences were observed after 28days cell culture. Transmission Electron Microscopy (TEM) images performed on 21day samples showed evidence of structured collagen fibers in the treated samples. All together, these results demonstrate the effectiveness of high frequency vibration treatment on hASC differentiation toward osteoblasts.

Hepatocellular mitochondrial alterations in patients with chronic hepatitis C: ultrastructural and biochemical findings.

OBJECTIVE: Hepatitis C virus (HCV) infection is associated with increased lipoperoxidation, which may lead to interference with mitochondrial function with possible depletion of mitochondrial DNA (mtDNA). We correlated the ultrastructural findings of liver biopsy specimens with the lipoperoxidation markers and contents of mtDNA in chronic hepatitis C (CHC) patients with a different HCV genotype. METHODS: Liver biopsy samples obtained from 75 CHC patients were processed for histological and electron microscopic examination. Twenty-two subjects without known liver disease served as controls. Hepatic glutathione in its reduced (H-GSH) and oxidized (H-GSSG) forms were determined from biopsy specimens by high-performance liquid chromatography. Plasmatic and lymphocytic GSH and erythrocytic malonyldialdehyde (MDA) were also determined, along with the ratio between mtDNA and nuclear DNA (nDNA). RESULTS: Ultrastructural alterations of the mitochondria were documented in 23 patients with genotype 1b, compared with 15 patients with genotype 2a/2c (p = 0.020) and seven patients with genotype 3a (p < 0.001). A significant depletion of H-GSH and lymphocytic GSH, an increase of H-GSSG and MDA, and a reduction of the mtDNA/nDNA ratio were documented in patients with genotype 1b, compared with patients with genotype 2a/2c and 3a and with controls. CONCLUSIONS: In patients with genotype 1b frequent ultrastructural alterations of the mitochondria may be observed, and the depletion of mtDNA in these patients may represent the expression of a greater impairment of the process of oxidative phosphorylation. An increased production of free radicals in patients with genotype 1b may influence the evolution of the liver disease by enhancement of the cytopathic effect of HCV.