Comparison of polypropylene and polyethylene terephthalate (Dacron) meshes for abdominal wall hernia repair: a chemical and morphological study.

For the first time, by scanning electron microscopy (SEM), polypropylene (PP) excised meshes (ethylene oxide sterilized) for abdominal wall hernia repair have been shown to be greatly damaged physically, independently of the implantation time, while the polyethylene terephthalate (PET), or Dacron, ones (gamma radiation sterilized), did not undergo alterations due to the sterilization process and were not damaged, even after long implantation periods. Fourier-Transform Infrared Spectroscopy (FTIR) study of PP and PET excised meshes, as well as of their extracts with cyclohexane, has shown the presence of species, such as squalene, palmitic and stearic acid, in some cases, cholesterol, transferred from the surrounding tissues to the polymer during the implantation period. In the case of PP meshes, these small organic molecules would reduce physical and mechanical properties of the material. A hypothesis is presented to account for the better behavior (not in the clinical sense) of PET meshes.

Structural alterations of prosthetic meshes in humans.

The use of prosthetic mesh in abdominal wall hernia surgery is a well-accepted practice. What is not settled, however, is the type of prosthesis that best suits the purpose. The narrow choice today means a prosthesis of polyester or polypropylene. These are available in many designs, configuration of weave, thickness of weave and strand, and size of pore. There has been a pervasive feeling that these materials "shrink". To what extent they do has not been accurately defined. This study was designed to measure such "shrinkage". Interestingly, our measurements revealed that prosthetic meshes could "expand" as well as "shrink". The extent to which they do varies between -40% and 58.5%. Whereas it was felt that fibrocyte activity and its eventual scar formation accounted for the "shrinkage" of the mesh, we have discovered that structural alterations in the size of the mesh pores can be affected by distilled water, saline, blood, formalin, bleach, as well as in vivo implantation. Prosthetic meshes are, therefore, not the inert materials they are claimed to be and can expand as well as shrink. We have, unfortunately, not been able to correlate the degree or direction of change to any known parameter.

The biological reaction to polyethylene wear debris can be related with oxidation of the UHMWPE cups.

BACKGROUND: Oxidised UHMWPE due to gamma irradiation in air has a greater susceptibility to wear than non-oxidised UHMWPE (ethylene oxide, EtO). AIM: To evaluate, the biological reaction of loose implants with oxidised and non-oxidised PE components. MATERIALS AND METHODS: Ten loose PE cups sterilised by EtO (group 1) and 13 sterilised by gamma irradiation in air (group 2) were studied. PE wear and oxidation were related to biological reaction. RESULTS: Group 1: PE cups had low wear score and no oxidation. In the oldest implants, a few PE particles and macrophages were observed in the interface membrane. Group 2: PE inserts had medium-to-high PE wear score and variable oxidation. In the interface membrane, the number and total area of PE particles were high and variable; giant cells were more numerous than macrophages. CONCLUSION: Junctional tissues around loose oxidised PE components contain more PE debris and giant cells than membranes around PE components that are not oxidised.

[Squamous carcinoma of the gallbladder. Anatomo-clinical study of a case with reference to oncogene expression]. / Carcinoma squamoso della colecisti. Studio anatomo-clinico di un caso con riferimento all'espressione di oncogeni.

Squamous cell carcinoma of the gallbladder is a rare tumor with an ill-defined clinical course. We report a case of pure squamous carcinoma of the gallbladder with a rapidly fatal outcome. The tumor cells were positive for oncogenes P53, c-Erb B2 and Ki 67. This feature has no comparison with other reported cases of squamous carcinoma of the gallbladder but it is in accordance with oncogene expression in adenocarcinomas.

Poorly differentiated thyroid carcinomas with primordial cell component. A group of aggressive lesions sharing insular, trabecular, and solid patterns.

Poorly differentiated carcinomas of the thyroid share insular, trabecular, and solid histological patterns that are different from those of papillary, follicular, medullary, and anaplastic varieties. We have collected 63 cases of poorly differentiated thyroid carcinomas. Thirty-one tumors (Group A) corresponded to the so-called insular carcinomas, and 32 tumors (Group B) had predominant trabecular and solid or focally follicular patterns in the presence of a minor insular component. The cells characterizing these lesions were relatively small and globoid, with uniform nuclei and intracytoplasmic deposits of thyroglobulin. They were in every respect similar to primordial cells present in the early stages of fetal thyroid development. None of the tumors proved fatal within 6 months, and most responded to radioiodine therapy. Although no differences in survival between the two groups were found, a significantly (p < 0.01) higher percentage of recurrences or distant metastases was observed with Group A tumors. The term primordial cell carcinoma appears appropriate for this type of tumor, which displays characteristic histocytological features and production of thyroglobulin. Clinically, these tumors are aggressive but generally show a slow course and good response to radioiodine therapy.

[Abdominal desmoid tumor]. / I desmoidi addominali.

Two cases of desmoid tumor of the abdominal wall are reported, together with some considerations and a review of the literature; desmoid tumor is an unusual neoplasm which affects women in prevalence. This is an histologically benign neoplasm with no metastatic capacity; however it is highly invasive in the site where it arose, so its treatment can become very difficult. The treatment is by surgical excision that must be as wide as possible, in order to obviate the great incidence of recurrence. The role of radiotherapy, hormone and chemotherapy has not been completely assessed so far.

[Lipoid hyperplasia of the ileocecal valve. A report of 2 cases operated on in the occlusive phase]. / La lipoiperplasia della valvola ileo-ciecale. Osservazione di due casi operati in fase occlusiva.

Two cases of lipomatosis of the ileocaecal valve, causing intestinal obstruction are reported. Surgery was performed on an emergency basis. A careful assessment of clinical and radiological findings is important, in order to distinguish such as a disease from caecal carcinoma. In fact this is a benign disease, for which conservative surgery is indicated.

[Comparative morphological study of the structure of the normal and arteriosclerotic internal mammary, coronary, and renal artery wall]. / Studio comparativo morfologico della struttura della parete delle arterie mammarie interne coronarie e renali indenni ed affette da aterosclerosi.

Morphological comparative study of the normal anatomy of the internal mammary artery, coronary artery and renal artery, and their atherosclerotic alterations. We report in this paper the comparative results of a morphological and morphometrical study of the normal anatomy of the Left Coronary Artery (interventricular descending branch) (LCA), Internal Mammary Artery (IMA) and Renal Artery (RA) and their atherosclerotic alterations in 27 unselected people of both sexes aging from 19 to 76 years (average 59 +/- 14.3). Sections from three different segments of each vessel were examined by measuring the thickness of the intima and media calculated at the maximum intimal thickening. The lumen was also measured at the level of its highest pathological reduction; the same measurements were carried out on sections free from atherosclerotic damage. Then the intima to media ratio was assumed as major indicator of atherosclerosis involvement according to the literature. All these parameters were statistically analysed. With these procedures we found that LCA displayed more severely atherosclerotic changes than IMA. The degree of damage in RA fell in between when compared to the other arteries. The intima to media ratio average was 0.061 mm. (+/- 0.084) in I.M.A.; 0.882 mm. (+/- 0.753) in L.C.A. and 0.272 (+/- 0.315) in RA with statistically significant differences between IMA and LCA (p less than 0.001) and between IMA and RA (p less than 0.001). In the lesion free sections intima to media ratios were 0.178 (+/- 0.90) in LCA, 0.053 (+/- 0.28) in IMA and 0.082 (+/- 0.127) in RA. The difference was statistically significative between LCA and IMA, but not between RA and IMA.(ABSTRACT TRUNCATED AT 250 WORDS)

[Actinic lesions of the small intestine requiring surgery. Case reports]. / Le lesioni attiniche del tenue di pertinenza chirurgica. Contributo casistico.

Radiation enteropathy is a disease that seldom requires surgical treatment, in the chronic variety. We report the findings of four cases we operated in an attempt to identify the weak points of surgery involving a high percentage and morbidity of mortality. NPT (total parenteral nutrition) can favour a positive evolution with total rest of the bowel and with reinstatement of normal nutrition.

[Incidence of atherosclerosis of the internal mammary artery compared with the coronary artery. A study of 22 non-selected autopsy cases]. / Incidenza dell'aterosclerosi sull'arteria mammaria interna rispetto al distretto coronarico. Studio autoptico di 22 casi non selezionati.

In the present work the examination and comparison of the degree of atherosclerotic involvement of the left coronary artery (CDA) and internal mammary artery (AMI) was performed on 22 unselected subjects at necroscopy examination. The maximum age was 77 and the minimal was 25 (average 62.59 +/- 2.47); 13 were male and 9 female. We macroscopically and microscopically examined three sections obtained from three different segments for each vessel. First we macroscopically evaluated the degree of narrowing of the lumen giving a score (+ to +). (Tab. II). Then the sections, 6 micron thick, stained with Haematoxylin-eosine, Alcian blue, PAS and Van Gieson methods were accurately examined at microscope with a graduated eyepiece. The lumen, the intima and the media were measured at the level of maximum thickness of the intima. Then the thickness of intima and the intima to media ratio, accordingly to the literature, were assumed as major indicators of atherosclerosis involvement. The intima to media ratio average was 5.05 (+/- 5.81) in the CDA vs. 0.44 (+/- 0.29) in the AMI (p less than 0.001). The intima in the CDA was 0.86 mm (+/- 0.76) thick (average) vs. 0.09 mm (+/- 0.07) in the AMI (p less than 0.001). These results show a great difference in atherosclerosis involvement which results to be ten times greater in CDA than in AMI in non selected people. Almost the same result is obtained by the measurement of the intima. On the contrary no detectable difference was found between the media of the two vessels.

[Collageno-vascular diseases and interstitial pulmonary fibrosis. An analysis of diagnostic tests]. / Malattie collageno-vascolari e fibrosi interstiziale polmonare. Una analisi dei tests diagnostici.

Collagenovascular diseases, particularly rheumatoid arthritis, LES and scleroderma frequently involve the lung. A group of 15 patients with collagen vasculopathies was analysed with a view to identifying the most suitable invasive and noninvasive tests for the diagnosis of the interstitial fibrosis of the lung that often accompanies such disorders. Among the noninvasive tests only the respiratory function tests (especially DLCO) are adequately sensitive, while chest X-rays, gallium scintigraphy of the lung and ACE are relatively unreliable. Bronchoalveolar lavage is often altered (though the intensity varies considerably) and transbronchial biopsy appears to be the ideal diagnostic examination.

Immunohistochemical and enzyme histochemical contributions to the problem concerning the role of the thymus in the pathogenesis of myasthenia gravis.

Normal fetal and postnatal thymuses, as well as thymuses from patients with myasthenia gravis (MG), were investigated by immunohistochemical and enzyme histochemical techniques and their morphology reviewed. Intrathymic B-cells, detected by ATPase activity, were found to be markedly increased in number in MG thymuses. They were scattered in the medulla and accumulated around the junctional and medullary vessels and Hassall's corpuscles (HCs). Large epithelial cells, singly or within HCs, were found to be unevenly distributed in the medulla of all the thymuses examined. The striated muscle-like nature of some of these cells was revealed by the presence of myoglobin in their cytoplasm. In myasthenics these cells and small developing HCs characteristically surrounded lymph follicles and were in direct contact with the expanded cap of the follicle mantle, without interposition of reticulin fibres. The close association of immune reactive foci (lymphoid follicles, junctional and medullary vessels, and HCs) with structures involved in autoimmune responses in the thymus (muscle-like and true myoid cells, HCs) strongly suggests that the autoimmune reactions against AChR (acetylcholine receptor) and other muscular components, which constitute the basic defects in myasthenia gravis, may begin in the thymus.

Histochemical study on human germinal centre, mantle-zone and extra-follicular area lymphoid cell subpopulations. Immunological and cytochemical correlations with lymphomatous cells, peripheral normal and leukemic lymphocytes.

Tissue sections of lymph nodes, appendices and tonsils, together with smears of immunologically separated peripheral lymphoid cells from a B-CLL and lymphomatous cells from an immunocytoma were submitted to combined enzyme cytochemical investigations with acid alpha-naphthyl acetate esterase (ANAE), beta-glucuronidase (B-G), acid phosphatase (AcPh), adenosine triphosphatase (ATPase), a,d 5'nucleotidase (5'N). T-cells were Acph+, ATPase- and 5'N-. The vast majority of T- and B-cells displayed ANAE and B-G activities with two distinct staining patterns (T-like and B-like pattern). A high proportion of lymphoid cells in the germinal centre (G.C.) and the vast majority of lymphoid cells in the mantle-zone (M.Z.) were shown to belong to B-cell system because of the expression of ATPase and 5'N in their membranes. Some lymphoid cells positive for ANAE and B-G with a B-like pattern and for AcPh were recognizable in the G.C. In the M.Z. only a few lymphoid cells being ANAE+, with a T-like pattern, and AcPh+ were shown to belong to the T-cell system. In contrast, in this zone a high proportion of small lymphoid cells (64% +/- 10%) showed ANAE activity, mostly with B-like pattern. Therefore, these findings indicate that in the M.Z. a high proportion of B-cells ATPase+ and 5'N+ also display ANAE activity. By comparison of the results obtained from lymphoid tissue sections, B-CLL and immunocytoma cell suspensions and normal circulating lymphocytes we can conclude that B-ANAE-positive cells of the M.Z. do not usually appear in the peripheral blood. They circulate in large numbers only in some pathological conditions (like our reported B-CLL). Therefore, B-ANAE-positive lymphoid cells of the mantle, with a B-like staining pattern, include a wide range of subsets which exclude large lymphoid cells and plasma cells.

Myoepithelial cells in lobular carcinoma in situ of the breast: a parallel immunocytochemical and ultrastructural study.

The distribution and morphology of myoepithelial cells in one case of normal breast and in 4 cases of lobular carcinoma in situ (LCIS) were studed by immunoperoxidase and immunofluorescence with anti-actin antisera and by electron microscopy. The actin-rich cells appeared to lay flattened on the basement membrane, or perpendicular to it, or appeared dislodged toward the center of the neoplastic ductules in the different cases. It is proposed that the presence of actin-rich cells inside the neoplastic aggregates represents a process of colonization of lobular carcinoma by myoepithelial cells dislodged from the basement membrane; a differentiation of some neoplastic cells toward myoepithelial elements might also be taken into consideration. The features here described could identify a preinvasive stage of LCIS.

Contraction features in normal and hypodynamic lizard ventricle.

Isometric twitches and intra- and extracellular electrical activity were recorded at various driving rates from lizard ventricles, either in the normal inotropic state, or in a hypodynamic state induced by perfusing at a high flow rate for a long time. Electron micrographs were obtained from hearts fixed immediately after dissection and from preparations perfused in vitro for various periods. It was found that the peak of the steady-state strength-interval relationship shifts towards higher stimulation rates with the development of hypodynamia. Such a change is similar to that induced in normal preparations by perfusing with calcium-poor solutions. The normal strength-interval relationship can be restored in hypodynamic preparations by perfusion with a calcium-rich solution. Also, in the hypodynamic state, the action potential duration is increased and (+ dP/dt)max is decreased, while the shape of the staircases at various stimulation rates is modified. These changes occur in the presence of well-preserved ultrastructural features of the preparation. The results suggest that the twitch tension results from the contribution of two Ca ions fluxes: an early one from a cellular store, and a late one related to the action potential duration. The ultrastructural findings are consistent with the hypothesis that a store, from which a rapid release of calcium occurs, exists in the lizard ventricle. A hypodynamic state would be caused by a reduced calcium affinity of such store, and by a decreased Ca++ influx during the action potential plateau.

Analysis of human lymphocyte cell cycle kinetics in vitro by incorporation into DNA of bromodeoxyuridine.

Human lymphocytes of four donors were cultured for 40 to 76 hours and harvested at 4 hour intervals. They were analysed for the number of 1st, 2nd and 3rd division metaphases using the BrdU-Giemsa technique. All 44 hours cultures showed metaphases only in their 1st division; 2nd division metaphases began to appear in 48 hours cultures and 3rd division metaphases in 64 hours cultures. Another group of lymphocytes from 4 other donors were irradiated and harvested at 72 hours. These cultures showed a decrease in the percentage of 3rd division metaphases, accompanied by an increase in the percentage of 1st division metaphases, proportional to the irradiation dose.