Showing papers by "University of Siena published in 1990"

Estrogen preserves a normal intestinal responsiveness to 1,25-dihydroxyvitamin D3 in oophorectomized women.

Abstract: Estrogen treatment improves calcium malabsorption induced by surgical or natural menopause, but the mechanisms involved are still under debate, with both increased production of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and improved peripheral responsiveness to the steroid having been proposed To address this issue, we studied the effect of short term administration of 1,25-(OH)2D3 (1 μg/day for 7 days) on intestinal fractional absorption of 47Ca (47Ca FA) and vertebral bone density, measured by dual photon absorptiometry, in 14 premenopausal women (aged 31–50 yr) before and 6 months after oophorectomy After surgery, patients were randomly allocated to a 6-month treatment with either conjugated estrogens (0625 mg/day; n = 7) or placebo (n = 7) Oophorectomy caused a decrease in both basal 47Ca FA (−408 ± 234%; P = 0004) and vertebral bone density (−721 ± 120%; P < 0001) in the placebo group Estrogen replacement prevented these changes and increased basal serum 1,25-(OH)2D3 (+103 ± 109%; P = 004

A case-control study of gastric cancer and diet in Italy: II. Association with nutrients

Abstract: A case-control study involving interviews with 1,016 gastric cancer (GC) patients and 1,159 population-based controls in high- and low-risk areas was conducted to evaluate dietary factors and their contribution to the marked geographic variation in mortality from this cancer within Italy. Risks of GC were found to vary significantly with estimated nutrient intake. Risk rose with increasing consumption of nitrites and protein, and decreased in proportion to intake of ascorbic acid, beta-carotene, alpha-tocopherol, and vegetable fat. The associations with nitrite and beta-carotene tended to fade, however, in multivariate analyses adjusting for intake of other nutrients. Ascorbic acid showed the strongest geographic gradient, with highest consumption in low-risk areas. The findings suggest that the protective effects we previously reported for consumption of fresh fruit, fresh vegetables and olive oil may be linked to the vitamins C and E contained in these foods. The findings are consistent with the hypothesis that N-nitroso compounds are involved in GC risks, since elevated risks were apparent for agents (nitrites, protein) that promote nitrosation, while decreased risks were found for nutrients (ascorbic acid and alpha-tocopherol) which inhibit the process.

Studies on the biological effects of ozone 1. Induction of interferon gamma on human leucocytes.

Abstract: In this study we have investigated the effects of ozone on human blood, as well as on resuspended buffy coats and Ficoll-purified mononuclear cells. Samples were exposed at different ozone concentrations (from 2.2 micrograms to 108 micrograms/ml) for 30 sec and then incubated for different times at 37 degrees C in a 95% air-5% CO2 humidified atmosphere. Supernatants were collected and frozen at-20 degrees C until tested for interferon (IFN) activity. We have determined that the ozone concentration is critical for lymphokine induction. In fact, while low concentrations (2.2 micrograms/ml) are effective in lymphocytes, they do not induce IFN in either whole or diluted (1:1) human blood, or resuspended buffy coats. In such cases levels as high as 42 micrograms/ml are required. On the other hand, a very high ozone concentration (108 micrograms/ml) is not effective and probably toxic. Maximal IFN production occurs 72-96 h after ozone exposure, and the kinetics of IFN release is similar to that after Staphylococcal Enterotoxin B addition. Because ozonization of blood is a medical procedure followed in several countries for treatment of viral diseases, this study can open a new field of investigation that may yield useful results both in biological and practical terms.

Pathogenesis of posterior capsular opacification. Part I. Epidemiological and clinico-statistical data.

Abstract: We examined 895 eves having extracapsular cataract surgery; 403 had an intraocular lens (IOL) implanted and 492 did not. The incidence of posterior capsular opacification was 7.69% in the eyes with an IOL and 14.23% in the eyes without an IOL. If we exclude complicated cataracts from the cases that did not have an IOL, the incidence of posterior capsular opacification decreases to 9.06%. Various models of implanted IOLs showed different incidences of posterior capsular opacification: For J-looped lenses the incidence was 11.02%; for Frezzotti-Caporossi lenses, 7.35%. The follow-up Nvas too short for soft lenses. The Frezzotti-Caporossi lens can he inserted with the convex side either anterior or posterior. A statistical evaluation shows that the reverse optic or posterior convex orientation in the bag caused a lower incidence of posterior capsular opacification (3.01%).

Hodgkin's disease and CD30-positive anaplastic large cell lymphomas--a continuous spectrum of malignant disorders. A quantitative morphometric and immunohistologic study.

Abstract: The authors have examined cellular areas of lymphoma tissue in 28 cases of Hodgkin's disease (HD) or anaplastic large cell lymphoma (ALCL, 'Ki-1 cell lymphoma') to evaluate the boundaries between the two entities. Methods applied included conventional histology; test point analysis; semiautomated morphometry of nuclear profile features of Reed-Sternberg and other atypical large cells (RSALCs); and immunohistochemistry of these elements on all paraffin sections and, in 15 cases, on frozen sections. Mean nuclear profile morphotypes of RSALCs per case varied independently of immunophenotype and histologic diagnosis. Conversely, immunohistochemistry demonstrated significant, although not consistent, preferential positivities of these CD30+ elements for CD15 in HD, and for epithelial membrane antigen (EMA) and CD43 in ALCLs. In the latter, RSALCs also exhibited a tendency for CD45 and CD45RO positivity and for the expression of T-cell-associated antigens. However, there were considerable overlaps. This continuous spectrum of RSALC nuclear profile morphotypes and immunophenotypes, ranging from HD over questionable cases, intermediate between HD and ALCL, to ALCLs, was paralleled by differences in the reactive component of lymphomas. Lymphocytes and granulocytes were significantly deficient in ALCLs.

Effects of androgen treatment in impotent men with normal and low levels of free testosterone.

Abstract: The relation between sexual function and serum free testosterone (fT) levels, which represent the active fraction of circulating testosterone, was evaluated. Two groups of impotent male subjects with mild hypogonadism were treated with oral testosterone undecanoate (TU); these men presented with tT/luteinizing hormone (LH) ratio and tT levels at the lower limits of normal. The first group had serum fT below 6.6 ng/ml, considered the lower normal value, according to our laboratory method, whereas the second group had normal fT limits. Administration of TU improved sexual function only in impotent men with low fT levels, but not in subjects with normal fT levels, even though the tT levels and the tT/LH ratio of the two groups were not significantly different. The results of our study suggest the presence of a minimun serum fT threshold, lying near the lower normal range, which determines the male sexual function. Moreover, serum fT levels were a more sensitive index than tT for identifying impotent men who can be successfully treated with androgens.

Pathogenesis of posterior capsular opacification Part II: Histopathological and in vitro culture findings

Abstract: The most interesting sources of information about the pathogenesis of posterior capsular opacification seem to be histopathological studies and in vitro tissue cultures. Since our surgical technique is extracapsular cataract extraction, the explants we used for tissue culture consisted of the anterior capsule epithelial sheet without the equatorial germinative zone. We successfully overcame several problems by using the autologous plasma clot culture method. This medium, considered the optimal one for this type of culture, allowed us to study the heterogeneous behavior of the epithelial cells in culture. Using the plasma clot culture method, we were able to demonstrate in vitro fibroblastic transformation of the epithelial cells. Histopathological findings of particular cases of posterior capsule opacification and immunohistochemistry of the human lens are also reported.

Characterization by high performance liquid chromatography (HPLC) of the solubilization of phosphorus in iron ore by a fungus

Abstract: The value of iron ore is adversely affected by phosphorus in concentrations over 0.03% by weight. The present research concerns the use of metabolic products of aPenicillium-like fungus to leach insoluble phosphates (hydroxyapatite) from ores. Ion chromatography was used to measure metabolism of glucose into acidic fragments. The rate and products of glucose degradation depended on both the chemical composition of the growth medium (buffered or not) and incubation conditions (shaken or quiescent). The principal products were identified as oxalic acid and isomers of propylene dicarboxylic acid, mainly itaconic acid. Continued, slow metabolism of itaconic acid generates more oxalic acid. Aliphatic acids were not detected. Both iron ore phosphate and calcium phosphate were partially solubilized by either the spent broth or aqueous oxalic acid. Solubilization of ore phosphorus was greatly assisted by hydrochloric acid added to the spent broth in small increments. The data suggest biological alternatives to costly leaching procedures that use only mineral acids.

Centriole and centrosome cycle in the early Drosophila embryo.

Abstract: Centriole and centrosome cycles were examined by indirect immunofluorescence and electron microscopy techniques in the early Drosophila embryo. The centrosomes, which are already divided at interphase, appear as compact spheres during prophase and metaphase, expand and flatten from anaphase to telophase and split into two units in late telophase. Centriole separation starts in late metaphase, becomes evident in anaphase and increases during telophase. Procentrioles appear during the following interphase.

Chromium(VI)-resistant yeast isolated from a sewage treatment plant receiving tannery wastes.

Abstract: A Cr(VI)-resistant yeast, designated strain DBVPG 6502, was isolated from a sewage treatment plant receiving wastes from tannery industries in Italy. The strain was tentatively identified as a species of Candida based on morphological and physiological analyses. This strain was highly resistant to Cr(VI) when compared with eight other yeast species, growing at Cr(VI) concentrations of up to 500 micrograms/ml (10 mM). This resistance was constitutive. The Cr(VI)-resistant yeast did not reduce Cr(VI) to Cr(III) species under aerobic conditions. The yeast showed very little accumulation of Cr(VI). Consequently, the mechanism of resistance of the yeast to Cr(VI) appears to involve reduced accumulation of Cr, as has been shown in Cr(VI)-resistant bacteria.

Improved cardiac performance with human calcitonin gene related peptide in patients with congestive heart failure

Abstract: Study objective – The aim of the study was to assess the cardiovascular effects of human calcitonin gene related peptide (CGRP) in patients with congestive heart failure. Design – The effects of CGRP II (or β), 12.5 μg·h−1, given by intravenous infusion for 24 h to digitalised patients with congestive heart failure, were assessed by measurement of cardiac functional indices. Patients – Five patients (four female) were studied. Age was 73-82 years. Three were in New York Heart Association phase III and two in phase IV. Measurements and main results – The pre-ejection period to left ventricular ejection time ratio and the QT distance adjusted for heart rate were lowered by 21% and 4% respectively. The left ventricular shortening index was raised by 43%. The arterial pressure and heart rate did not change consistently. Conclusion – Calcitonin gene related peptide improves myocardial contractility in patients with congestive heart failure. This is the first time this has been shown.

Measurement of cutaneous colour and assessment of skin type.

Abstract: Skin colour was evaluated in summer in 91 Caucasian volunteers by means of a Minolta Chroma Meter CR-200, a colour analyser for measuring the reflective colour of surfaces by the tristimulus system. All the subjects were classified for skin type according to Fitzpatrick and minimal erythema dose determined. The skin colour of the buttock was taken to be the constitutive skin colour, and that of the cheek the facultative skin colour. It was found that the chromaticity of exposed skin was noticeably different from that of unexposed skin, being situated to the right of the latter in the chromaticity diagram. This means that skin that is usually exposed to the sun has a more intense red component, presumably because of increased vascularization. Exposed skin also showed lower reflectance (Y) or lightness (L*) than unexposed skin, probably because of pigmentation. Hence delta Y and delta L* give an approximate idea of the tanning capacity of each subject. delta Y and delta L* of skin types II and III were greater than delta Y and delta L* of skin type IV. This means that, with chronic exposure to sunlight, even fair skin can achieve a reasonable pigmentation. It is concluded that constitutive skin colour is a more meaningful parameter than facultative skin colour in assessing skin type.

Intraneural Synovial Cyst of the Peroneal Nerve: Report of Two Cases and Review of The Literature

Abstract: We report two cases of peroneal nerve compression caused by an intraneural synovial cyst and discuss the pathogenesis, clinical and electrophysiological diagnosis, and treatment of these uncommon lesions in the light of the salient published work on the subject.

Hydrocephalus, bronchiectasis, and ciliary aplasia.

Abstract: A girl presented in the neonatal period with hydrocephalus, bronchiectasis, and ciliary aplasia. A common defect both in respiratory tract cilia and in ventricular ependyma cilia may explain the association of the two diseases.

Extended generalized quadrangles

Abstract: Extended generalized quadrangles (roughly, connected structures whose every residue is a generalized quadrangle) are studied in some detail, especially those which are uniform or strongly uniform. Much basic structure theory is developed, many examples are given, and something approaching characterization is given for many types.

A fibrillar elastic apparatus around human lymph capillaries.

Abstract: A fibrillar elastic apparatus around the wall of human lymph capillaries is demonstrated by means of histochemical and ultrastructural techniques. This apparatus consists of three interlinked components listed here in order of increasing distance from the capillary wall: 1) oxytalan fibres connected to the abluminal surface of the endothelial cells, known also as “anchoring filaments” and consisting of bundles of microfibrils; 2) elaunin fibres consisting of microfibrils and a small amount of elastin; and 3) typical elastic fibres consisting of microfibrils and abundant elastin. The microfibrillar constituent has similar ultrastructural features in the three components of the elastic apparatus. Microfibrils have a diameter of 12–14 nm, an electrontransparent core and a wall with 3–5 electron-dense subunits and oblique cross striations with a period of 15–17 nm. Microfibrils are the common element of the three components of the elastic apparatus and they link them to one another and to the elastic network of the perivascular connective tissue. An elastic apparatus was not found around blood capillaries and it can thus provide a histological marker to identify lymph capillaries. The possible role of the lymphatic elastic apparatus in the physiological activity of the lymphatic absorbing network is discussed and it is proposed that its disconnection from the elastic network of the tissue may promote pathological conditions such as lymphoedema or diseases related to impaired immune responses.

Harmomegathic characters of Pteridophyta spores and Spermatophyta pollen

Abstract: Spore and pollen grain volume decrease after meiotic cleavage and starts to increase during exine and intine formation; with dehydration volume decreases again. In the atmosphere pollen volume accomodates according to relative humidity. The mechanisms leading to and regulating dehydration of the sporangia and anthers, the stationary phase during dispersal, and hydration are species specific. They vary between taxonomic groups and are influenced by the environment. Pollen adhesion occurs only in angiosperms and is a prerequisite for pollen hydration; the opposite is true for gymnosperms. The environment of the landing site determines physical recognition which enables proper hydration to take place. Another instance of physical recognition is found in fern spores before germination, and involves temperature and light quality. Chemical recognition appears only in Spermatophyta. The water for rehydration is provided in different was in pteridophytes, gymnosperms and angiosperms, and the molarity of the hydrating solutions varies. In vitro hydration tests have demonstrated that Pteridophyta spores achieve maximum size in water, whereas the optimum media for gymnosperms and angiosperms have sucrose concentrations of 5–50 g/l. The volume of Spermatophyta pollen grains decreases during germination but that of Pteridophyta spores increases. The increase percentages in volume from the dry to the hydrated state vary between species and depend on the hydration site and the spore/grain itself. The internal factors are: hydration of the intine, selective permeability of the plasma membrane, hydration state of the cytoplasm, and accomodating power of the walls. Different devices regulate these volumetric changes in angiosperm pollen grains, e.g., furrows and apertures. Harmomegathic devices are less variable in gymnosperm that in angiosperm pollen, and even less variable in the pteridophytes.

Long-term treatment with calcitriol in postmenopausal osteoporosis

Abstract: In order to assess the long-term effects of calcitriol treatment in postmenopausal osteoporotic patients, 1.0 micrograms/d of calcitriol was administered in two divided doses for 1 to 8 years to 270 women with symptomatic, histologically proven postmenopausal osteoporosis. No calcium supplementation was given. Clinically, the treatment resulted in substantial relief from pain, with improvement of ambulancy. Intestinal calcium absorption, which was lower than normal at baseline, increased significantly and remained higher than the baseline value as long as calcitriol was administered. Urinary calcium absorption also increased, but hypercalcemia occurred, exceptionally and transiently, in only a few patients. Urinary hydroxyproline excretion did not increase, indicating that hypercalciuria was not of resorptive origin. Total-body density, determined by dual-photon total-body absorptiometry in 56 patients, showed an increase after 18 to 24 months of therapy in most cases. The occurrence of nontraumatic, clinically relevant fractures decreased noticeably as compared with the period preceding calcitriol treatment. No change occurred in renal function, and no renal stones developed. Calcitriol was an effective and safe treatment of postmenopausal osteoporosis.