Experimental ischemic liver injury and regeneration over 3 months: Histological observations in the rat

Liver histopathology of segmental portal ischemia occuring over a long-term period has not been previously described. For these reasons histological changes in the rat liver were studied from 1 h to up to 90 days after a left lateral and middle segmental portal obstruction. Within 3 h, the hepatocytes showed glycogen depletion in Rappaport zones 1 and 2 and pericentral and central lobular congestion of sinusoids and veins, whereas within 3 days, vein thrombosis appeared in the center of the lobule and liver necrosis was observed in Rappaport zones 2 or 3 or both, followed by restitutio ad integrum of the liver lobule morphology after 20-40 days. These results can be explained in light of two conditions occurring in the rat liver: (i) the peculiar low sensitivity of the liver to O-2 debit and the protective or vasoactive effects used during hypoxia; and (ii) the sinusoidal network as a collateral source of the hepatic vascular system. Therefore, morphological assessment of this arteriolar and sinusoidal system, implicated in assuring efficient collateral blood supply in the rat liver with portal ischemia, is essential for understanding the mechanisms behind a natural and timely repair of ischemic injuries in the human liver

lnununohistochernical detection of cel1-cycle associated markers on paraffin ernbedded and formalin fixed needle biopsies of prostate cancer: correlation of p120 protein expression with AgNOR, PCNA/Cyclin, Ki-67/MIB1 proliferation-scores and Gleason gradings.

Paraffin embedded and formalin fixed needle biopsies of prostate cancer (PC) were used to immunocytochemically detect the p120 nucleolar protein in relation to the Gleason histological gradings (GHG), the labelling indices of proliferating nuclear immunocytochemical markers (PCNA/Cyclin, Ki-67/MIB1) and the argyrophilic nucleolar region (AgNOR) rate. The twenty-six cases of PC (6 from large histological samples and 20 from needle biopsies) were equally distributed into low ( or = 7) GHG groups. The p120 nucleolar protein immunocytochemical reaction was randomly expressed in large histological sections but uniformly distributed without gaps in needle biopsy sections. Only on the latter were quantitative values of PCNA/Cyclin (23.2 in low and 45.3 in high GHG), Ki-67/MIB1 (13.8 in low and 43.3 in high GHG) and AgNOR (5.0 in low and 7.5 in high GHG) related to those of p120 nucleolar protein (0.8 in low and 3.8 in high GHG). The values of all these cell cycle markers increased from low to high GHG of PC, all four reaching high statistical significance between the two groups (ANOVA-two tailed p < 0.0001). The PCNA/Cyclin index showed a higher positivity than the Ki-67/MIB1 index in PC with low GHG but not in PC with high GHG. In conclusion, paraffin embedded and formalin fixed PC needle biopsies exhibit a higher diagnostic PCNA/Cyclin than Ki-67/MIB1 index for cases presenting differentiated features, whereas p120 nucleolar protein detection seems to be a suitable marker of poorer outcome of PC

PROLIFERATING CELL NUCLEAR ANTIGEN CYCLIN IN INCIDENTAL CARCINOMA OF THE PROSTATE

Monoclonal antibody to proliferating cell nuclear antigen (PCNA) has been used to identify the growth fraction in ten cases of benign prostatic hyperplasia (BPH), in 20 prostatic microcarcinomas (PMC) and in 30 cases of infiltrating prostatic carcinoma (PC). Ten year follow-up was available on all cases by means of clinical, serological, radiological and echographic examinations. The percentage of PCNA-staining nuclei was independently counted by two observers. Statistical analysis showed significant differences between PCNA/cyclin score of BPH and PMC without recurrences with respect to those of PMC with progression and of PC. PCNA immunostaining may represent a reliable method for assessing cellular proliferative activity. It may be used as a more powerful diagnostic hallmark of PMC than patterns of non-malignant microglandular proliferation and is also a useful additional test for assigning histological grades to PMC and PC. Statistical analysis indicated that PCNA/cyclin index was an independent significant prognostic indicator of predicting malignant progression (P less-than-or-equal-to 0.01) and survival rates (P less-than-or-equal-to 0.05) of PC and PMC (> 5 mm diameter)

Proliferating cell nuclear antigen/cyclin in incidental carcinoma of the prostate.

Monoclonal antibody to proliferating cell nuclear antigen (PCNA) has been used to identify the growth fraction in ten cases of benign prostatic hyperplasia (BPH), in 20 prostatic microcarcinomas (PMC) and in 30 cases of infiltrating prostatic carcinoma (PC). Ten year follow-up was available on all cases by means of clinical, serological, radiological and echographic examinations. The percentage of PCNA-staining nuclei was independently counted by two observers. Statistical analysis showed significant differences between PCNA/cyclin score of BPH and PMC without recurrences with respect to those of PMC with progression and of PC. PCNA immunostaining may represent a reliable method for assessing cellular proliferative activity. It may be used as a more powerful diagnostic hallmark of PMC than patterns of non-malignant microglandular proliferation and is also a useful additional test for assigning histological grades to PMC and PC. Statistical analysis indicated that PCNA/cyclin index was an independent significant prognostic indicator of predicting malignant progression (P 5 mm diameter)

Histological study on sinus lift grafting by Fisiograft and Bio-Oss

The work aims to provide a histological investigation of Fisiograft(R) a PLA/PGA copolymer, used as filler for bone defects in humans. The study was performed on biopsies of sinus lifts where Bio-Oss(R) and Fisiograft(R) gel were applied as graft material. Bone regeneration was satisfactory in all sinus lifts, even when Fisiograft(R) was applied alone. Due to remarkable osteoclast activity, Bio-Oss(R) granules were cleared from the majority of biopsy cores. At histology, Fisiograft(R) gel appeared as globes enveloped by fibroblasts, displaying an epithelial-like cell appearance. Due to its solubility in solvents, undegraded Fisiograft(R) (recorded for 7 months or more) did not stain whereas degraded Fisiograft(R) stained positive. The loose connective tissue, that surrounded Fisiograft(R), and bone contained isolated mastocytes. Bone grew inside the loose connective and often reached the surface of Fisiograft(R) by intervening cells. The results seem to indicate that Fisiograft(R) may be considered both a polymer useful for fastening bone substitutes inside a defect and in addition a material capable of prompting bone regeneration, with or without the use of a bone substitute. In addition to space-former and space-maintainer functions, Fisiograft(R) shows potential bone stimulation function, which may be labelled as osteopromotive capability

Rabbit bone behavior after orthodontic and pulsed low-frequency electromagnetic field treatments

The effect of low-frequency pulsed electromagnetic fields (PEMF) on bone was studied after an orthodontic treatment. A spring was positioned between the incisors and the first molar on both sides of the rabbit mandible for 14 days. A PEMF treatment was performed 6 h/day on the right side only. A greater distance between the first and the second molar was recorded in the PEMF treated side with respect to the left side. In addition, analysis of undecalcified sections shows a lower number and width of erosion cavities and a greater amount of newly formed (fluorescent) bone on the right side. In conclusion, PEMF treatment not only appears to increase bone formation, as previously reported in the literature, but, acting on osteoclast activity, also seems to improve bone quality during orthodontic treatment

MELANOSIS (PIGMENTED MELANOCYTOSIS) OF THE PROSTATE GLAND.

A case of stromal melanosis of the prostate gland is reported. Ultrastructurally, dendritic processes and melanosomes, but no basal lamina were observed in melanin-containing cells. In similar cases, characterized by the diffuse distribution of stromal pigmented melanocytes, the term "pigmented melanocytosis" rather than "blue naevus" appears more appropriate