Search PubMed⌕ Search

Biomedical subjects

S Gnudi

Publications and source records attributed to S Gnudi.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Experimental osteoporosis caused by estrogen deficiency in rats. Role of a lactose, L-arginine and L-lysine combination in the prevention and therapy].

The role of a lactose, L-arginine and L-lysine association in the treatment of osteoporosis was evaluated in an in vivo model. Fifty Sprague Dawley female rats, 10 months age, were divided into 5 groups: 10 non-ovariectomized animals sacrificed at the beginning of the study (I group); 10 ovariectomized animals (OVX) without treatment and sacrificed at three months (II group); 10 OVX animals without treatment sacrificed at 6 months; 10 OVX animals treated starting from the I post-operative day with the association for three months (IV group, prevention) and 10 OVX animals treated like those of the IV group starting three months after surgery (V group, therapy). Animals were sacrificed in general anesthesia according to the scheduled times for radiologic, densitometric, histologic and mineralogic investigations. Preliminary results, which will need further researches, seem to show a progressive reduction of bone mass after ovariectomy in 10 months female rat and that the pharmacological association given as therapy (V group) may be able to lessen the reduction of bone mineral content.

Animals↗
PubMed1996

[Femoral densitometry as potential preoperative indicator for cementation of hip prosthesis].

This work suggests a densitometric protocol for femoral studies in arthrosic patients candidate to total hip arthroplasty. The protocol was applied retrospectively to 60 cases to investigate its possible future use as a tool for the preoperative planning of prosthetic stem fixation techniques-i.e., cemented vs. uncemented. The well-known standard procedures for femoral densitometric studies by dual-energy X-ray absorptiometry (DXA), are usually applied to the femoral neck, Ward's triangle and the greater trochanter. Unfortunately, these analyses lose their significance if applied to arthrosic hips, and arthrosis is the main condition requiring total hip arthroplasty. Our protocol for femoral studies in arthrosic patients includes the preoperative analysis of 7 regions of interest in the proximal shaft, similar to Gruen's regions. In vivo precision tests show variation coefficients ranging 0.9-3.7%. The protocol was applied to a series of 60 arthrosic patients who were submitted to total hip arthroplasty by the same surgical staff. Twenty of them were implanted a cemented stem and the other 40 an uncemented ("press-fit") stem. Densitometric results were communicated only after surgery, to avoid any bias on the normal decision-making process usually used to choose the fixation technique for the prosthetic stem. The two groups of cemented vs. uncemented stems had different distribution of densitometric values. Therefore, the information obtained with femoral densitometric studies preoperatively can play a major role in the choice between cemented and uncemented stems. Moreover, if femoral densitometric studies are carried out preoperatively, their results can be closely related to periprosthetic tissue remodeling and implant follow-up.

Adult↗
PubMed1995

Ultrasound in the evaluation of osteoporosis: a comparison with bone mineral density at distal radius.

It is proven that, from a technical point of view, ultrasound transmission velocity (UTV) measurement can easily be taken at the distal end of the radius. The reproducibility of UTV is good (coefficient of variation 0.3% intraoperator and 0.5% interoperator). 248 normal and 65 osteoporotic women were then studied to establish the range of UTV values and to compare the ability of UTV and bone mineral density (BMD) measurement, taken at the same skeletal sites, to detect osteoporotic fragility. Osteoporosis was defined by the presence of atraumatic vertebral fractures on an X-ray of the spine. Ultrasound velocity averaged 1570.5 +/- 43.3 m s-1 in normal and 1519.2 +/- 15.2 m s-1 in osteoporotic women; the difference is also statistically significant (p < 0.01) for BMD. Both BMD and UTV decline after menopause and are significantly correlated with age. A weak correlation (r = 0.68) was found between UTV and BMD; this supports the thesis that ultrasound velocity measures bone mass as well as other fragility components of bone distinct from the decrease of mass. Receiver operating characteristic (ROC) curve analysis showed that UTV discriminates between normal and osteoporotic patients at least as well as radial BMD, indicating that UTV is a new available diagnostic modality which can be used to screen osteoporotic subjects.

Adult↗
PubMed1993

Morphological and structural characteristics of the myopathic bone.

The aim of the present paper was to study the myopathic bone both from the morphological and structural viewpoints. To this end, samples from 8 patients affected by different neuromuscular diseases (DMD, SMA and CMD) have been examined. Thus, by SEM analysis a quantitative reduction of the trabeculae and an increase in porosity of the myopathic bone were found and also, by diffractometric analysis, the presence of pathologic crystalline phases (beta-TCP and beta-TCP-Mg).

Adolescent↗
PubMed1993

Osteoporosis by ovariectomy: calcitonin effect in an experimental model on the rat.

The authors evaluate the efficacy of the aminosuberic derivative of eel calcitonin (eCT) in preventing post-ovariectomy osteoporosis in adult rats. The drug is administered in a dose of 0.5 U.I./day for four months starting from the moment of the ovariectomy. The results show that the treatment is efficacious in preventing bone mass loss due to ovariectomy and that the action of the drug does not bring about alterations in the normal crystalline structure of the bone.

Alkaline Phosphatase↗
PubMed1993

[Prevention of post-ovariectomy osteoporosis in the rat. Comparative study of synthetic salmon calcitonin and eel calcitonin aminosuberic analogue].

The authors evaluate the efficacy of salmon calcitonin and aminosuberic analogue of eel calcitonin in the prevention of post-oophorectomy osteoporosis in rats. Both drugs, administered at the same dosage, are equally effective in preventing oophorectomy bone loss in rats. Besides, plasma biochemical evaluations demonstrate that calcitonins reduce bone turnover in treated rats, compared with control oophorectomized ones.

Absorptiometry, Photon↗
PubMed1993

Home parenteral nutrition for the management of chronic intestinal failure: a 34 patient-year experience.

Home parenteral nutrition (HPN) was used for the treatment of 18 patients with chronic intestinal failure (CIF): short bowel syndrome (9), extensive intestinal disease (4), motility disorder (4), entero-enteric fistulas (1). The underlying diseases were: chronic inflammatory (7), mesenteric vascular (4), scleroderma (2), pseudo-obstruction (2), malignancy (2), radiation enteritis (1). HPN was more effective on protein-calorie nutritional status than on fluid and electrolyte balances. About two-thirds of the patients achieved full or partial social rehabilitation. During the 6 months before HPN, there were 20 hospitalizations (mean stay: 55 days). During HPN (mean length of treatment: 22 months/patient) there were 16 hospitalizations (mean stay: 22 days), 8 of which were caused by HPN complications (sepsis and deep vein thrombosis; overall incidence of catheter-related complications: 0.411 per patient-year). Bone demineralization, liver abnormalities and biliary stones developed, respectively, in 57%, 28% and 11% of the cases. The underlying intestinal condition played a role in their pathogenesis. The annual cost of HPN ranged from 40 (Hospital Pharmacy Service) to 80 (commercial firm) million lire per patient. To sum up, HPN improves the nutritional status and the quality of life of patients with CIF, and the risk of complications is acceptable. The medical and social advantages are considered to offset the cost of the technique.

Adult↗
PubMed1993

[Effect of high and low doses of methotrexate (MTX) on bone mass in subjects treated for osteosarcoma of the limbs].

Twenty-three patients with highly malignant localized osteosarcoma receiving neoadjuvant chemotherapy with MTX randomly administered at high (7500 mg/m2) and low (750 mg/m2) doses underwent serial densitometric controls at the start of treatment and after 18 and 36 months. Increasing BMC levels at both examination points were observed in all subjects examined over time, but, contrary to findings in the control group, this increase was not statistically significant using the paired T test. Significantly lower BMC levels in relation to the control group were only found in the group treated with high doses of MTX at MDP but not PM. Reduced density at MDP alone, a site in which trabecular bone is prevalent, shows that MTX predominantly acts at the level of the latter in line with its greater sensitivity to the action of osteopenic agents.

Adolescent↗
PubMed1992

SEM and chemical micro-analysis in a failed total knee prosthesis.

Authors performed SEM and EDS analyses in a cemented removed knee prosthesis demonstrating the average values of mineral elements in the bone surrounding the prosthesis. The composition of the metallic prosthesis surface in different microareas was also studied.

Alloys↗
PubMed1991

[Ultrasound in the diagnosis of fragilitas ossium].

Recently, a proposal has been made to evaluate bone fragility in osteoporotic women by measuring ultrasound transmission velocity at the patella. Theoretically, sound transmission velocity depends on both bone mass and other factors which are not mass-dependent--e.g. bone architecture. Ultrasound transmission technique was thus tested for the capability of evaluating bone fragility factors, which are not mass-dependent, in the screening of osteoporotic women. To this purpose, the sound velocity at the patella of 31 healthy women was compared with that of 62 osteoporotic women with spontaneous vertebral fractures having similar bone mineral content. In 31 cases bone mineral content was similar to that of healthy women at the middle radius, and in 31 at the distal radius. Sound transmission velocity was significantly lower in osteoporotic than in healthy women. Fifty-two per cent of healthy women was correctly selected by US, relative to the risk threshold, versus 13% with bone mineral densitometry. This finding suggests that US is capable of distinguishing normal from osteoporotic women having similar bone mineral content, which means that non-mass-dependent factors may affect US velocity in the bone. Since the measurement were taken in various sites, different for US and bone densitometry, our results need confirmation in further studies where measurements are taken in the same sites.

Bone Density↗
PubMed1991

Influence of the fluoride ion in the stability of bone hydroxyapatite achieved in patients after the fluo-calcic therapy.

It has been proposed that fluoride ion might actively enter into the basic structural framework of the bone, within its main constituent, the hydroxyapatite (HA), by substituting systematically the OH- ion in the crystal chemical formula Ca5[(PO4)3OH]. Accurate compositional studies have become necessary in order to explain an eventual stabilizing effect. Loss in weight (TG) and chemical reaction (DTG) while varying the temperature have been carried out for the first time on specimens under normal conditions and after fluo-calcic treatment, in parallel with accurate chemical compositional determinations by atomic absorption analysis. Our investigation shows that the new structure present after treatment is mechanically stable and proves more resistant to osteolytic processes.

Bone Neoplasms↗
PubMed1990

Bone mineral alterations and Mg content in aging.

The authors propose to determine whether the quantity of bone mass reduction linked to aging is accompanied by qualitative modifications of the mineral structure. To this end, 18 samples of cancellous bone from the femoral heads of two groups of patients (Groups A & B), were examined. Group A was made up of 8 old osteopenic patients suffering from fracture of the femur neck (age 62-84). Group B consisted of 10 young non-osteopenic subjects (age 34-53). Through chemical analysis a statistically significant percentage increase in Mg++ was noted in Group A and, by X-Ray diffraction, significant presence of beta-TCP. Mineral structure alterations occur in the process of aging of the skeletal tissue.

Adult↗
PubMed1990

The importance of urinary hydroxyproline and serumal osteocalcin in the evaluation of post-menopausal osteoporosis.

Forty-nine women aged 49 to 65 who had been in menopause for more than fifteen years were selected on the basis of densitometric data and clinical symptomatology. Twenty-four of these suffered from severe backaches and had a bone mineral content (B.M.C.) level inferior by at least three standard deviations to the average level according to the standards of our laboratory; these women were diagnosed with severe osteoporosis. The remaining twenty-five subjects were asymptomatic with a B.M.C. between one and two SD from the average; these were diagnosed with moderate asymptomatic osteopenia. A control group was formed by ten apparently healthy women of childbearing age. The women with severe osteoporosis showed a significantly lower level of serumal osteocalcin (Student t Test: P less than 0.05) than the control group, while no significant difference was observed between the latter and the women with moderate asymptomatic osteopenia. The level of hydroxyproline was significantly higher (Student t Test: P less than 0.01) in both groups of menopausal women than in the control group. This data shows that the increase in the level of urinary hydroxyproline characterizes menopause independent of the severity of bone loss. On the other hand, low levels of osteocalcin mainly appear in menopausal women who show severe skeletal demineralization. As a result, we feel that the urinary hydroxyproline/osteocalcin ratio is shown to be useful in both evaluating the risk of post-menopausal osteoporosis and monitoring it.

Adult↗
PubMed1990

Evaluation of the relative rates of bone mineral content loss in postmenopause due to both estrogen deficiency and ageing.

To evaluate the relative rates of bone mineral content loss in postmenopause due to both estrogen deficiency and ageing, three groups of women were studied by computerized bone densitometry at the radius mid-point and at the distal point, modified according to the Abwrey technique. All women were in apparent good health and never had estrogen therapy. In the first group there were 64 women aged between 30 and 50 who were ovariectomized between 25 and 35 years of age. The second group was made up of 309 women between 50 and 55 years. In the third group there were 136 women aged 30-50 with normal ovaric function. The ordinary functions of linear polynomial regression were used to describe the variations in density with age. The percentage of postmenopausal bone loss was determined by calculating the BMC value at the start of the menopause and again twenty years later, according to the linear regression equation of postmenopausal period of each group of women in the study. The women who had natural menopause showed an average bone loss per year of 1.63% at the mid radius and 1.0% at the distal point. The ovariectomized women had an average loss of 0.85% at the mid point and 0.66% at the distal point. No significant decrease of bone mass was found before menopause. From a comparison between the two groups of women with analogous periods of menopause, it comes out that, during the first 20 years of natural menopause, estrogen deficiency is responsible for 52.5%-66.4% of the bone mineral loss, the remaining amount being attributable to other causes, connected with ageing. Estrogen deficiency is therefore, the principal factor causing bone mineral loss in natural menopause.

Adult↗
PubMed1988

Densitometric analysis in in vivo evaluation of synthetic salmon calcitonin activity.

In women suffering from post-menopausal osteoporosis, we evaluated the effectiveness of two cyclic treatments with synthetic salmon calcitonin over a whole year, using an average daily dose of 16 and 32 IU, respectively. This treatment was compared with treatment with oral calcium carbonate. The results, evaluated by peripheral densitometry of the radius, showed a 3.2% loss of bone mineral content (BMC) in the women treated only with calcium carbonate, a loss of 1% in those treated with an average dose of 16 IU/day of calcitonin and an increase of 4% in the women treated with an average dose of 32 IU/day (an increase just above the statistically significant limit using the paired t-test). An average dose of 32 IU/day probably represents the minimum effective dose of calcitonin required to produce a significant increase in bone mineral mass, when used according to a sequential scheme.

Aged↗