A finite element method comparison of wear in two metal-on-metal total hip prostheses.

The contact mechanics of two metal-on-metal (MOM) total hip prostheses was studied by means of the finite element method (FEM). The purpose of the work was to compare two total hip replacements (Durom and Metasul) with regard to the amount of wear debris released. Wear on the bearing surfaces was evaluated following Reye hypotheses from the pressure distribution, computed by means of three-dimensional FEM models; an approximate analytical model based on Hertz contact theory has also been developed and discussed. The results show that in the dry friction condition the Durom joint releases almost twice as much wear volume as produced by the Metasul joint. Therefore, while Durom implants can improve hip stability by increasing the prosthetic impingement-free range of motion (PIF-ROM), Metasul prostheses can be a valuable solution whenever wear represents a critical choice factor.

[Echocardiographic analysis of the left ventricular mass in smokers]. / Analisi ecocardiografica della massa ventricolare sinistra nei fumatori.

A morphometric echocardiographic analysis of left ventricular mass was performed in 110 heavy smokers and 110 controls aged 20-60. Taken as a whole, the smoker group revealed a higher ventricular mass index (88.4 +/- 19.5 v 78.3 +/- 16.8 g/sq m; p less than 0.01). The difference was not significant in the 20-40 age group (78.1 +/- 18.3 v 76.7 +/- 18.1 g/sq m) but was highly significant (p less than 0.001) in the 41-60 age group (96.0 +/- 18.8 v 80.7 +/- 15.8 g/sq m). The increase in mass may be related to increased catecholamine incretion, raised blood viscosity due to increased fibrinogen and haemocrite and to transitory but repeated increases in telesystolic stress caused by the cigarette smoke. The increase in myocardial mass together with other well-known coronary alterations induced by smoking might explain the greater incidence an severity of ischaemic heart disease, not to mention sudden death among heavy smokers.

[Treatment with enalapril maleate in patients with arterial hypertension, pluri-metabolic syndrome and habitual snoring]. / Trattamento con enalapril maleato in pazienti affetti da ipertensione arteriosa, sindrome plurimetabolica, russamento abituale.

The effects of enalapril maleate were studied in a group of 6 patients with arterial hypertension, hypertensive cardiopathy, multiple metabolic disorders and habitual snoring. Earlier treatment with antihypertensive drugs (diuretics, antiadrenergics, calcium antagonists) had been suspended when a marked deterioration was noted in metabolic parameters and plasmatic electrolytes as well as extremely disturbed sleep. The latter is probably attributable to increased respiratory obstruction during the night as a result of the increased hypertonia of the muscles of the upper air ways due to low blood potassium as well as the central and peripheral effects of the antiadrenergic drugs. After the wash-out period there was a marked improvement in laboratory parameters that continued after treatment with enalapril maleate. In particular, apart from a further slight fall in blood cholesterol and uricaemia there was a statistically significant drop in triglyceride levels. The improvement in the laboratory parameters made it possible to reduce the doses of the drugs being taken for the metabolic disorders. A distinct improvement was also noted in the sleep disturbances especially the excessive drowsiness during the day. There was also a statistically significant drop in arterial, systolic, diastolic and mean blood pressure without any significant change in heart beat. The results indicate that enalapril maleate should be the treatment of choice for those patients in whom high blood pressure is accompanied by alterations to the main metabolic parameters and habitual snoring.

[Aspecific bronchial reactivity during pharmacologic treatment of arterial hypertension]. / La reattività bronchiale aspecifica in corso di trattamento farmacologico della ipertensione arteriosa.

The study of 216 hospitalised patients with essential arterial hypertension (108 males and 108 females) revealed a high percentage of essential arterial hypertension associated with other diseases, in particular chronic obstructive lung disease in males. The behaviour of bronchial hyperreactivity was studied in 10 patients by means of inhalation tests with carbachol in order to assess the extent of the condition and its response to antihypertensive treatment with alpha-methyldopa. The result showed that the drug had no effect on bronchial reactivity and is therefore to be recommended even in cases where chronic aspecific lung disease is associated with arterial hypertension.

[Case of voluminous post-traumatic adrenal hematoma with pseudotumorous appearance associated with systo-diastolic arterial hypertension]. / Su un caso di voluminoso ematoma surrenalico post-traumatico con aspetto pseudotumorale associato ad ipertensione arteriosa sisto-diastolica.

A right adrenal post-traumatic haematoma with no symptoms but arterial hypertension was described. Echography, urography and CT suggested a malignant tumor, but surgery only demonstrated the real nature of the supra-renal mass.

[Edematogenic syndrome in diabetics treated with insulin: a little-known complication]. / Sindrome edemigena nei diabetici trattati con insulina: una complicanza poco conosciuta.

Two cases of insulin oedema similar to that of nephrotic syndrome were described. It appeared in two diabetic patients after the beginning of insulin therapy, when glycemia was normalized, as described by other Authors, with a spontaneous tendency to decrease. Pleural and pericardial effusion were also associated. The possible pathogenesis of insulin oedema in the two cases was discussed.

[Nitrendipine, a new calcium antagonist, in the therapy of arterial hypertension]. / La nitrendipina, un nuovo calcio-antagonista, nella terapia dell'ipertensione arteriosa.

Bay e 5009 (nitrendipine) is a new calcium-antagonist that acts mainly on blood vessel smooth muscles. The effects of this drug on hypertensive patients of both sexes was investigated. Nine patients were treated for 42 days at a fixed dosage of 1 tablet/day. A highly significant fall in arterial pressure was obtained (p less than 0.001). Seven patients took 20 mg/day of nitrendipine for 14 days and a significant reduction in A.P. was obtained (p less than 0.001): for the next four weeks, the dosage was increased to 20 mg twice a day when a further decrease in systolic and diastolic A.P. was obtained without the occurrence of side effects. A further five patients were treated for 14 day (20 mg/day). These showed a fall in blood pressure levels (p less than 0.001) but suffered from slight oedema which made it necessary to suspend the treatment. An increase in heart rate was noted in all patients (p less than 0.001). This was due to reflex adrenergic activation. Nitrendipine therefore proved effective as an antihypertensive drug even at a daily dose of only 20 mg.

Evaluation of the structural quality of bone in a case of progressive osteoporosis complicating a Complex Regional Pain Syndrome (CRPS) of the upper limb.

Densitometry is considered to be the gold standard in bone quality assessment. However, since its introduction, the medical community has been aware that mineral density is only one of the factors that influence the bone risk of fracture, which also depends on the bone's trabecular arrangement and, in particular, on the trabecular architecture's load bearing capabilities. At the University of Trieste, in recent years, a test has been developed that simulates the application of compressive loads on trabecular architecture's reconstructions extracted from digital radiographs. In this work, the test is described, and the results obtained by applying the appraisal in a particular case of severe osteoporosis of the hand, complicating a Complex Regional Pain Syndrome (CRPS) type II, are presented. The test was able to quantify the pathological alterations of bone micro-architecture by means of a Structural Index (SI), which was absolutely significant and relevant to the clinical situation. Important research and clinical opportunities of application of the test include accurate evaluation of osteoporotic bone diseases, careful clinical follow-up and monitoring of responses to therapeutic approaches, and, prospectively, reliable quantification of biological damage (forensic field).

Structural analysis of rat bone explants kept in vitro in simulated microgravity conditions.

Skeletal abnormalities reported in humans and laboratory animals after spaceflight, include cancellous osteopenia, decreased cortical and cancellous bone formation, aberrant matrix ultrastructure, decreased mineralization and reduced bone strength. Although considerable effort has been made up to now to understand the skeletal effects of spaceflight, in order to estimate health risk, our knowledge in this area is still largely incomplete. It is widely accepted that the mechanical strength of cancellous bone is related not only to the mineral content, but also to the trabecular micro-architecture arrangement. Three-dimensional numerical analysis of bone volumes has been shown to be an important tool in this field. The Cell Method, a recently introduced numerical method, has been applied to static analysis of structures obtained from 3D reconstruction of micro-computed tomography scans performed at the Elettra Synchrotron facility (Trieste, Italy) in order to quantify changes in trabecular bone architecture. In the present study, the Cell Method model is used to compare the micro-tomographed structure of fragments of rats bone explants (tibial proximal epiphyses) harvested after 3 days and after 1, 2, 3 and 4 weeks of culture in the RCCS bioreactor, which represents the unique existing bioreactor, operating on the Earth's surface, capable of successfully reproducing, in vitro, optimal conditions in order to simulate a microgravity environment. Although preliminary, our results seem to suggest that the exposure of tibial bone explants to simulated microgravity conditions obtained by the RCCS bioreactor, are consistent with skeletal changes observed after spaceflight.

The application of the cell method in a clinical assessment of bone fracture risk.

The aim of this paper is to introduce a new technique for in vivo quantification of bone structure fracture risk. The elastic properties of the architecture obtained from bone digital radiographic images are determined using the cell method. Compression tests are simulated and the results of the numerical analysis are indexed. Such an index is considered to be indicative of the bone structure capabilities. The first clinical validation was carried on at CSMMO, Centro Studi Malattie Metaboliche dell'Osso (Gorizia, Italy), showing that this technique can improve the diagnosis and help a physician in the identification of an actual fracture risk. The examination is not expensive, uses instrumentation that is widely available and therefore could be easily introduced in clinical use as a complement to the current osteoporosis diagnosis methodologies.

[Diagnostic study of 5 cases of allergic asthma due to sensitization to silk allergens in textile workers from the Prato area]. / Indagine diagnostica in 5 casi di asma allergico da sensibilizzazione ad allergeni della seta in lavoratori tessili dell'area pratese.

Five cases of allergic asthma due to sensitivity to silk allergens have been studied. All the patients worked in the Prato textile industry. The presence of specific antibodies against extracts of silk has been shown by the direct RAST and confirmed by the indirect RAST. The onset of the symptoms, with regard to the various stages in the processing of silk, leads one to assume that the allergen involved is sericin.

Clinical efficacy and tolerability of a steady dosage schedule of local nasal immunotherapy. Results of preseasonal treatment in grass pollen rhinitis.

BACKGROUND: Local nasal immunotherapy (LNIT) is an effective and safe alternative to conventional subcutaneous immunotherapy. A specific nasal provocation test (SNPT) could be used to indicate the optimal subclinical dose to carry out LNIT. OBJECTIVE: We hypothesize that LNIT could be carried out with only one predefined dose for all patients, so we have evaluated the efficacy and the tolerability of LNIT administered at steady dosages in patients with seasonal allergic rhinitis. METHODS: Twenty grass pollen-sensitized patients suffering from seasonal allergic rhinitis were studied in a randomized, double-blind, placebo-controlled trial. The treatment was carried out according to a schedule based on the administration of a steady subclinical dosage of the allergenic extract, selected on the basis of the sensitivity threshold of the SNPT. The patients were divided into two groups of 10 people each, which were treated either with grass pollen extract in a hydroglyceric solution or with placebo. RESULTS: During the peak pollen period, with regard to the placebo (P) group, in the grass treated (GT) group a significant decrease of both nasal symptoms (P = .021) and consumption of antihistamines (P = 0.047) was found. Furthermore, only in the GT group was the provocative dose assessed by the SNPT significantly lower (P = .049) at the end of the treatment. In this group of patients an inverse correlation between such provocative dose and the nasal symptom score reported during the peak pollen period was also evidenced (r = 0.708; P = .038). Adverse reactions to LNIT were mild, rare, and did not interfere with the completion of the therapeutic schedule. CONCLUSIONS: Our study indicates that LNIT, when administered at steady dosages, may be proposed as a treatment for grass pollen seasonal allergic rhinitis as it appears to be effective and well tolerated.

Combined therapy with benazepril and amlodipine in the treatment of hypertension inadequately controlled by an ACE inhibitor alone.

In a multicenter, randomized, double-blind, placebo-controlled study, we evaluated the efficacy and tolerability of the combination of benazepril, 10 mg, and amlodipine, 2.5 or 5 mg once daily, compared with benazepril, 10 mg, monotherapy in patients with hypertension inadequately controlled with angiotensin-converting enzyme (ACE)-inhibitor monotherapy. After a 2-week placebo and 4-week single-blind benazepril, 10 mg once daily, run-in period, 448 patients, 213 men and 235 women, aged 24-73 years (mean, 55 years), with mean diastolic blood pressure (DBP) > or =95 and < or =120 mm Hg at the end of the benazepril run-in period, were randomized to receive one of the following treatments once daily for 8 weeks: (a) benazepril, 10 mg, plus placebo (BZ10); (b) benazepril, 10 mg, plus amlodipine, 2.5 mg (BZ10/AML2.5); or (c) benazepril, 10 mg, plus amlodipine, 5 mg (BZ10/AML5). Before the patients were admitted to the trial, at the end of the placebo run-in and the benazepril run-in period and at the end of weeks 4 and 8 of the treatment period, sitting and standing blood pressure (BP), heart rate (HR), and body weight were measured 22-26 h after the intake of the trial medication. Both BZ10/AML2.5 and BZ10/AML5 combinations showed better antihypertensive activity than did BZ10 monotherapy at the terminal visit as demonstrated by (a) the 24-h postdosing sitting and standing systolic BP (SBP) and DBP values, which were statistically lower with combination therapy than with BZ10; (b) the success rate, which was statistically higher with both the combinations (69.2% in the BZ10/AML2.5 and 65.8% in the BZ10/AML5 group) compared with the BZ10 group (40.5%). The tolerability was good in the three treatment groups. No significant abnormal laboratory data were detected. There was no difference in efficacy and safety/tolerability between the BZ10/AML2.5 and BZ10/AML5 groups.