Anastomosis formation and nuclear and protoplasmic exchange in arbuscular mycorrhizal fungi.

We observed anastomosis between hyphae originating from the same spore and from different spores of the same isolate of the arbuscular mycorrhizal fungi Glomus mosseae, Glomus caledonium, and Glomus intraradices. The percentage of contacts leading to anastomosis ranged from 35 to 69% in hyphae from the same germling and from 34 to 90% in hyphae from different germlings. The number of anastomoses ranged from 0.6 to 1.3 per cm (length) of hyphae in mycelia originating from the same spore. No anastomoses were observed between hyphae from the same or different germlings of Gigaspora rosea and Scutellospora castanea; no interspecific or intergeneric hyphal fusions were observed. We monitored anastomosis formation with time-lapse and video-enhanced light microscopy. We observed complete fusion of hyphal walls and the migration of a mass of particles in both directions within the hyphal bridges. In hyphal bridges of G. caledonium, light-opaque particles moved at the speed of 1.8 +/- 0.06 microm/s. We observed nuclear migration between hyphae of the same germling and between hyphae belonging to different germlings of the same isolate of three Glomus species. Our work suggests that genetic exchange may occur through intermingling of nuclei during anastomosis formation and opens the way to studies of vegetative compatibility in natural populations of arbuscular mycorrhizal fungi.

[Microcalcifications associated with in situ ductal breast carcinoma. Mammographic and histological correlations with morphometric evaluation]. / Microcalcificazioni associate a carcinoma mammario duttale in situ. Correlazioni mammografiche e istologiche con valutazioni morfometriche.

This study includes 33 cases of ductal carcinoma in situ and its aim is to detect and classify microcalcifications according to their appearance, mammographically, histologically and morphometrically. From the histological point of view, intraductal carcinomas are classified following the criteria proposed by Holland et al. The types of carcinoma examined reveal the presence of different microcalcifications. The calcifications associated with G1 carcinomas appear as highly compact morphometrically, fine or mainly so mammographically and laminated or mixed histologically; no granular calcifications are observed. On the other hand, calcifications associated with type G2 appear as coarse mammographically, granular histologically and scarcely compact morphometrically. Finally, G3 carcinomas mainly reveal by mammography vermicular calcifications (in a few cases associated with fine ones). Granular calcifications are predominant on histological examination while morphometry shows the poorest level of compactness.

[Intravascular malignant lymphoma: report of a case]. / Linfoma maligno intravascolare: descrizione di un caso.

The authors describe a case of malignant intravascular angiotropic lymphoma presenting an atypical clinical and radiological picture. After postmortem examination, the histologic test performed on various organs showed massive proliferation of mononucleate neoplastic cells inside small and intermediate-sized vessels without involvement of the surrounding parenchyma. The immunohistochemical exams performed permitted the identification of the above-mentioned cells as lymphoid elements belonging to phenotype B. A bilateral papillar renal necrosis was detected. This necrosis, not mentioned by the preceding literature, was, in all probability, caused by alterations of the microcirculation.

[Fournier's gangrene: description of a case]. / Gangrena di Fournier: descrizione di un caso.

Fournier's gangrene, named after the french dermatologist who was the first to described it in 1883, is a necrotizing fasciitis which affects men's external genitalia and more rarely women's. In most cases the clinical onset is sudden, characterized by fever and local tumefaction rapidly evolving into gangrene. The most credited aetiology is infective and one or more aerobic and/or anaerobic micro-organisms are supposed to be the cause. The pathogenesis involves an endarteritic obliterative process affecting the small vessels of the superficial branch of the internal pudendal artery.

Spontaneous rupture of a pancreatic pseudocyst into the portal vein.

Spontaneous rupture of a pancreatic pseudocyst into the portal vein is described. This has been previously reported in only five cases. Diagnosis was made by computed tomography (CT) and was confirmed by CT-guided transhepatic portography.