Can wall shear-stress topology predict proliferative vitreoretinopathy localization following pars plana vitrectomy?

We numerically study the fluid dynamics of oil tamponade in models of vitrectomized eyes prompted by a subset of daily activities corresponding to movements on the horizontal plane with the patient in a standing position. Bulk flow features are related to near-wall flow topology and transport at the retinal surface through a wall shear-stress-based analysis. Proliferative VitreoRetinopathy (PVR) is the leading cause of retinal re-detachment occurring in about 20% of all cases due to the accumulation of inflammatory cells in discrete retinal regions. Signalling soluble mediators stimulate inflammatory cells' chemotaxis and studying their distribution across the retinal surface may acquire clinical relevance. In all the investigated cases, persistent and elongated regions along the retina, potentially prone to accumulate chemo-attractants and cells are observed. Gradients of soluble inflammation mediators present in the aqueous are known responsible for the so-called epithelial-mesenchymal transition that initiates PVR and favours recurrent retinal detachment prompting the proliferation of inflammatory cells with collagen matrix deposition and its contraction. The surgical apposition of encircling scleral buckling elements, known for over a century to influence PVR formation and localization, modifies the attracting regions, possibly causing an accumulation of molecules and cells along approximately vertical lines that follow the rising menisci due to the cerclage indentation. The resulting spatial pattern is compatible with clinical observations. This study may open toward rational analyses of near-wall transport to predict PVR pathogenesis by relating biochemical accumulation in certain areas of the retina to clinical conditions.

[Relevance and therapeutic implications of dysplasia in the follow-up of ulcerative rectocolitis]. / Significato ed implicazioni terapeutiche della displasia nel controllo della rettocolite ulcerosa.

Long standing ulcerative colitis (UC) is a condition capable of malignant transformation. Even if the rate of occurrence of carcinoma differs considerably among the various series, there is general agreement that it can be detectable in advance through the finding of glandular dysplasia. The Authors examine such a problem in a series of 27 patients submitted to clinical and endoscopic follow-up from 1984 to 1989. During this study a total of 237 rectosigmoidoscopies, 83 colonoscopies and 71 histologic exams were performed. At the outset mild or moderate dysplasia was found in 5 cases (18%). However, in the follow-up no evidence of dysplasia was detectable in 4 of the 5 cases. In the remaining case dysplasia was present only in one control. It was not found in the subsequent two histologic examinations. In our limited experience the incidence of dysplasia was not significant enough to require a prophylactic proctocolectomy. Instead a frequent and thorough endoscopic follow-up is recommended.

[Chronic gastritis. A study of 151 cases diagnosed using gastric biopsy]. / Gastriti croniche. Studio di 151 casi diagnosticati con biopsia gastrica.

With the aim to detect a correlation between endoscopic aspects and histological features of chronic gastritis, the Authors have analysed retrospectively a series of 151 cases where endoscopic alterations were likely due to chronic gastritis and in all cases multiple biopsies were performed. A possible correlation between endoscopy, histology and occurrence of intestinal metaplasia has been carefully evaluated. Only in chronic atrophic gastritis a certain relationship between endoscopic features and histologic diagnosis was detectable: in the same cases a high incidence of intestinal metaplasia was found as well, independently from the severity of endoscopic and/or histologic aspects. The Authors discuss the controversial problems in terminology and endoscopic definition of chronic gastritis.

[Prognostic value of CEA in postoperative monitoring of colorectal cancers]. / Valore prognostico del CEA nel monitoraggio post-operatorio dei carcinomi del colon-retto.

The prognostic value of CEA for the purposes of postoperative monitoring assessed in 45 patients with cancer of the colon and rectum. Values were obtained 1-36 months after surgery in all operable cases. Means were also evaluated statistically at various follow-up times. In patients who relapsed, values stayed significantly higher for up to 6 months after surgery than in those who did not. Cockran's method showed that the prognostic significance of this difference 6 months after surgery was p less than 0.05.

[Critical remarks on medullary cancer of the thyroid]. / Considerazioni critiche sul carcinoma midollare della tiroide.

Medullary carcinoma of the thyroid (MCT) is a rather uncommon neoplasia that must be correctly identified to allow a proper therapy. The Authors on the basis of their own series consisting of 223 surgically treated tumors of the thyroid, report 4 cases of MCT. In none of these cases the diagnosis was made before surgery. It is therefore stressed, to achieve an early diagnosis, the usefulness of the careful appraisal of the clinical data and of the complete biochemical and histo-pathological evaluation of each suspicious case. Such a policy allows to exclude all possibility of doubt.