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Biomedical subjects

C Gennari

Publications and source records attributed to C Gennari.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Usefulness of online bibliographic research in biomedical research, with an application to the epidemiologic study of genetic osteopathy].

The bibliographic research online is an useful means of recovering information in all the subjects, particularly in the field of biomedicine. In fact, this instrument allows researchers to get information in a rapid, complete and up-to-date way. The aim of the present review is to describe the usefulness of the bibliographical research online in the field of the genetic osteopathies. These are rare disorders: so, their own rarity makes the bibliographical research online necessary to carry out a large and effective comparison of experiences. The obtained results are amply reported in the manuscript. For instance, we verified that chondrodysplasias are the diseases most represented in the literature, while melorheostosis the disorder less mentioned. Moreover, we evidenced that some hereditary disorders of connective tissue, such as Marfan's syndrome, osteogenesis imperfecta and Ehlers-Danlos syndrome, are strongly influenced by race, sex and age.

Bibliometrics↗
PubMed1999

Novel reverse-turn mimics inhibit farnesyl transferase.

Reverse-turn inducing bicyclic lactams were incorporated into the substrate sequence recognized by farnesyl transferase to create inhibitors of RAS farnesylation. While the free peptides did not show any effect on the farnesylation, their Fmoc-protected counterparts impede the transformation of RAS with IC50's in the low micromolar range.

Alkyl and Aryl Transferases↗
PubMed1999

Risk factors for hip fracture in men from southern Europe: the MEDOS study. Mediterranean Osteoporosis Study.

The aims of this study were to identify risk factors for hip fracture in men aged 50 years or more. We identified 730 men with hip fracture from 14 centers from Portugal, Spain, France, Italy, Greece and Turkey during the course of a prospective study of hip fracture incidence and 1132 age-stratified controls selected from the neighborhood or population registers. The questionnaire examined aspects of work, physical activity past and present, diseases and drugs, height, weight, indices of co-morbidity and consumption of tobacco, alcohol, calcium, coffee and tea. Significant risk factors identified by univariate analysis included low body mass index (BMI), low sunlight exposure, a low degree of recreational physical activity, low consumption of milk and cheese, and a poor mental score. Co-morbidity including sleep disturbances, loss of weight, impaired mental status and poor appetite were also significant risk factors. Previous stroke with hemiplegia, prior fragility fractures, senile dementia, alcoholism and gastrectomy were associated with significant risk, whereas osteoarthrosis, nephrolithiasis and myocardial infarction were associated with lower risks. Taking medications was not associated with a difference in risk apart from a protective effect with the use of analgesics independent of co-existing osteoarthrosis and an increased risk with the use of anti-epileptic agents. Of the potentially 'reversible' risk factors, BMI, leisure exercise, exposure to sunlight and consumption of tea and alcohol and tobacco remained independent risk factors after multivariate analysis, accounting for 54% of hip fractures. Excluding BMI, 46% of fractures could be explained on the basis of the risk factors sought. Of the remaining factors low exposure to sunlight and decreased physical activity accounted for the highest attributable risks (14% and 9% respectively). The use of risk factors to predict hip fractures had relatively low sensitivity and specificity (59.6% and 61.0% respectively). We conclude that lifestyle factors are associated with significant differences in the risk of hip fracture. Potentially remediable factors including a low degree of physical exercise and a low BMI account for a large component of the total risk.

Aged↗
PubMed1999

Osteogenesis imperfecta: bone turnover, bone density, and ultrasound parameters.

We studied 21 patients (11 men and 10 women) with osteogenesis imperfecta (OI) and 21 age- and sex-matched controls. In all patients we measured serum levels of total alkaline phosphatase (ALP), type I procollagen carboxy-terminal propeptide (PICP), osteocalcin (BGP), urinary excretion of hydroxyproline (HOP/Cr), and pyridinoline crosslinks (Pyr/Cr). Bone mineral density was measured at the distal radius (BMD-R) and at the lumbar spine (BMD-LS) by dual X-ray absorptiometry (DXA). Ultrasound parameters were also performed at the calcaneous with the Achilles device and at the phalanxes with DBM Sonic 1200. A significant reduction (P < 0.001) in BMD and in ultrasound parameters was found in OI patients compared with normals. PICP was significantly reduced in the OI patients compared with controls (P < 0.001); other markers of bone turnover were higher in OI than in controls, but the difference did not reach the statistical significance. A significant correlation (P < 0.05) was found between PICP and BMD at the lumbar spine and between PICP and ultrasound parameters at the calcaneous. On the basis of our data, we conclude that patients with OI show low values of BMD and ultrasound parameters; therefore in these patients, not only is bone mass disturbed but also bone quality. The reduced levels of PICP in OI patients confirm that most OI patients have defects in collagen I biosynthesis. These defects may contribute to the fragility of OI bone by interfering with complete mineralization and/or normal tissue structure. PICP may be considered a useful marker in the clinical management of OI.

Absorptiometry, Photon↗
PubMed1999

Bone turnover and the response to alendronate treatment in postmenopausal osteoporosis.

This study investigated whether bone turnover influences the response to alendronate in women with postmenopausal osteoporosis. One hundred postmenopausal osteoporotic women were randomized to receive either alendronate (10 mg/day) plus calcium (1000 mg/day) (n = 50) or calcium alone (n = 50). Vertebral and radial bone density, measured by DXA, and markers of bone turnover were assessed at baseline and after 1 and 2 years. At the end of treatment, alendronate users showed an increase of 5.0% and 2.3%, respectively, at the lumbar spine and ultradistal radius; in the group treated only with calcium, bone mineral density (BMD) decreased by 1.6% at the lumbar spine and 1.3% at the ultradistal radius. The difference between the two groups was significant (P < 0.001). The patients were divided into high (HT) or low (LT) bone turnover groups, as assessed by 24-hour whole body retention (WBR%) of (99m)Tc-methylene-diphosphonate. The response to alendronate treatment was greater in HT patients compared with LT patients. In fact, at the end of the study period, BMD at the lumbar spine had increased by 7.9% in HT patients and by 3.0% in LT patients; the difference between the two groups was significant (P < 0.001). No significant difference between the two groups was found for BMD at the ultradistal radius. In conclusion, the present study demonstrates that 2-year treatment with alendronate has highly positive effects on bone mass at both the lumbar spine and ultradistal radius. The increase in bone mass, especially at the axial level, is influenced by bone turnover. Therefore, the evaluation of bone turnover may be useful in predicting the response to alendronate treatment.

Absorptiometry, Photon↗
PubMed1999

Quantitative ultrasound in the assessment of skeletal status in uremic patients.

Renal osteodystrophy (ROD) can be characterized by both high (HT) and low (LT) bone turnover states. Although bone biopsy remains the "gold standard" to diagnose ROD, noninvasive tools for the diagnosis and follow-up of such bone disease are desirable. Recently, ultrasound (US) techniques, proposed to assess skeletal status, have been shown to be correlated not only with bone density but also with bone quality. We have investigated 98 patients on chronic hemodyalisis (HD) and 98 healthy, sex- and age-matched subjects. Amplitude-dependent speed of sound (AD-SOS) and ultrasound bone profile score (UBPS) at phalanxes and speed of sound (SOS), broadband ultrasound attenuation (BUA), and a quantitative ultrasound index (QUI/stiffness) at the heel were performed in both groups. In all subjects intact parathyroid hormone (PTH), total alkaline phosphatase (T-ALP), bone isoenzyme alkaline phosphatase (B-ALP), and carboxy-terminal telopeptide of type I collagen (ICTP) were assessed. All US parameters were significantly lower in the hemodialysis group than in control subjects. Moreover, among US parameters only AD-SOS and UBPS showed a significant correlation with PTH, T-ALP, and B-ALP. Dialytic age showed a modest, but significant correlation only with US parameters at the phalanxes. On the basis of bone biochemical markers, we considered a group with high and a group with normal to low bone turnover. AD-SOS and UBPS, but not SOS, BUA, and stiffness were significantly (p < 0.01) lower in the high bone turnover than in low bone turnover group. Furthermore, in the high bone turnover group, parameters of the US phalanxes strongly correlated with B-ALP. Our results seem to demonstrate that US parameters are a useful tool in the assessment of skeletal status in patients on maintenance dialysis.

Adult↗
PubMed1999

Association of tibolone and fluoride displays a pronounced effect on bone mineral density in postmenopausal osteoporotic women.

A double-blind, placebo-controlled, randomized, prospective two-center study was carried out to assess the effects of tibolone + fluoride versus placebo + fluoride therapy on trabecular and cortical bone in postmenopausal osteoporotic women. Ninety-four subjects (mean age 61.1 years, postmenopausal 13.5 years on average) with low bone mineral density (BMD) at baseline were randomized to 2.5 mg of tibolone (Org OD 14, Livial) plus 26.4 mg of fluoride (Fluocalcic) or placebo plus 26.4 mg of fluoride daily over 2 years; 55 (58.5%) subjects completed the study, the main reason for discontinuation being untoward gastrointestinal effects. BMD at the lumbar spine was measured by both dual photon absorptiometry (DPA) and dual-energy X-ray absorptiometry (DXA), and at the hip by DXA at 6-month intervals. Baseline values (DXA, g/cm2) for tibolone + fluoride and placebo + fluoride groups were 0.733 and 0.744 for the lumbar spine, and 0.761 and 0.788 for the hip. Change from baseline and percentage change from baseline were calculated for the intent-to-treat and completers groups. An analysis of variance (ANOVA) model or Wilcoxon test was used for statistical evaluation. There was a mean increase in BMD at the lumbar spine measured by DPA of 25.3% and 12.3% in tibolone + fluoride and placebo + fluoride groups, respectively (p = 0.01); with DXA, respective changes were 32.6% and 14.0% (p = 0.013). Data on BMD at the hip showed mean increases of 7.9% and 2.6% for the tibolone + fluoride and placebo + fluoride groups, respectively. We conclude that combined tibolone + fluoride treatment induces a highly significant increase in BMD at the lumbar spine without simultaneous loss of the cortical bone allowing for a meaningful reduction of the fluoride dose when given in combination with tibolone.

Absorptiometry, Photon↗
PubMed1999

Food allergy and Helicobacter pylori infection.

BACKGROUND: Most antigens reach the immune system through mucosae. Gastrointestinal mucosa is a barrier for alimentary antigens. Inflammatory processes, such as Helicobacter pylori-associated gastritis, could alter the integrity of the gastric barrier, increase the mucosal permeability, and enhance crossing of food antigens which may stimulate allergic reactions. PURPOSE: The aim of this study was to establish whether patients with symptomatic food allergy and detectable immunoglobulin E (IgE) to alimentary antigens were infected by Helicobacter pylori more often than controls, and to determine the phenotype of the infecting Helicobacter pylori. PATIENTS AND METHODS: Thirty-eight consecutive patients with symptomatic food allergy and serum IgE to alimentary antigens, and 53 consecutive age-matched controls (subjects without food allergy and detectable levels of IgE anti-alimentary antigens) living in the same area and attending the same institution were investigated serologically to determine the prevalence of Helicobacter pylori infection, and an immune response to CagA, a marker of the most pathogenic strains. IgE to alimentary allergens were measured by a commercial kit. RESULTS: The prevalence of Helicobacter pylori infection in patients with food allergy and controls was similar (42.1% and 47.1%, respectively). Anti-CagA antibodies in Helicobacter pylori-infected persons were detected in 62.5% of patients with food allergy, and 28.0% of controls (p = 0.030, odds ratio = 4.29, RR = 2.23). The mean IgE level to the most common alimentary antigens was increased in CagA-positive, with respect to the CagA-negative, patients. CONCLUSIONS: The enhanced mucosal and inflammatory lesions commonly found in individuals infected by CagA-positive Helicobacter pylori strains could increase the epithelial permeability and render non-selective the passage of allergens which, in atopic persons, could directly stimulate an IgE response. Infection by CagA-positive Helicobacter pylori may increase the risk of food allergy.

Adolescent↗
PubMed1999

The infection by Helicobacter pylori strains expressing CagA is highly prevalent in women with autoimmune thyroid disorders.

UNLABELLED: H. pylori infection is putatively associated with extra-digestive disorders and may also play a role in the development of autoimmune thyroid diseases (ATD). It was recently found that monoclonal antibodies to an H. pylori strain with cagA-positivity reacted with follicular cells of the thyroid gland, and that an H. pylori organism possessing the cag pathogenicity island carried a gene encoding for an endogenous peroxidase. The aims of this study was (1); To ascertain whether the infection by strains endowed with an increased inflammatory potential (those expressing CagA) could further enhance the risk of developing ATD (2); To verify the possible existence of an immune cross-reactivity between autoantibodies to peroxidase and thyroglobulin and H. pylori antigens (3). To establish whether thyroid colloid antigens could cross-react with an anti-H. pylori serum. The study was partly designed retrospectively. We examined 41 consecutive women with ATD, and, as a control, 33 consecutive age- and socio-economic class-matched women without autoimmune thyroid disorders, living in the same area as patients, occurred at the same institution in the same period (six months). Both patients and controls were examined serologically for H. pylori infection and CagA status by Western blotting. Some serum samples were absorbed with H. pylori to determine whether the antibody levels decreased. Colloid proteins were resolved electrophoretically and matched with a hyperimmune serum raised in rabbits against a CagA-positive H. pylori. Thirty-two patients (78.0%) tested seropositive for H. pylori infection, vs. 16 controls (48.4%) (P = 0.008, OR = 3.78, RR = 1.61). The prevalence of anti-CagA antibodies was 71.8% in infected patients, and 50% in infected controls (P = 0.161, n.s.). The overall prevalence of infection by CagA-positive H. pylori was significantly higher in patients with ATD (23/41, or 56.0%) than that in controls (8/33, or 24.2%) (P = 0.006, OR = 3.99, RR = 2.31). The other tests gave negative or inexplicable results. IN CONCLUSION: CagA-positive H. pylori infection increases the risk of ATD development.

Adolescent↗
PubMed1999

CagA-positive Helicobacter pylori infection may increase the risk of food allergy development.

The aim of this study was to test whether patients with symptomatic food allergy and significant levels of immunoglobulin E (IgE) to alimentary antigens were more likely infected by H. pylori, especially by strains expressing the CagA protein, with respect to controls. A group of 38 patients with symptomatic food allergy and 53 age-matched controls were examined serologically for H. pylori infectious status, and for CagA seropositivity. IgE to alimentary allergens were measured by a commercial kit. The prevalence of H. pylori infection in patients with food allergy and controls was similar (42.1%, and 48.3%, respectively). However, anti-CagA antibodies in H. pylori-infected persons were detected in 62.5% of patients with food allergy, and 28% of controls (P = 0.030, odds ratio = 4.29). The mean level of IgE to the most common alimentary antigens in serum samples from infected patients with anti-CagA antibodies was significantly higher than in CagA-negative infected patients: 3.28 kU/L (SD 3.93), vs. 1.99 kU/L (SD 1.53), P = 0.002, 95% confidence interval = 0.61 to 2.53). Infection by CagA-positive H. pylori increases the risk of developing food allergy.

Adolescent↗
PubMed1998

Secondary osteoporosis.

Generalized osteoporosis currently represents a heterogeneous group of conditions with many different causes and pathogenetic mechanisms, that often are variably associated. The term "secondary" is applied to all patients with osteoporosis in whom the identifiable causal factors are other than menopause and aging. In this heterogeneous group of conditions, produced by many different pathogenetic mechanisms, a negative bone balance may be variably associated with low, normal or increased bone remodeling states. A consistent group of secondary osteoporosis is related to endocrinological or iatrogenic causes. Exogenous hypercortisolism may be considered an important risk factor for secondary osteoporosis in the community, and probably glucocorticoid-induced osteoporosis is the most common type of secondary osteoporosis. Supraphysiological doses of corticosteroids cause two abnormalities in bone metabolism: a relative increase in bone resorption, and a relative reduction in bone formation. Bone loss, mostly of trabecular bone, with its resultant fractures is the most incapacitating consequence of osteoporosis. The estimated incidence of fractures in patients prescribed corticosteroid is 30% to 50%. Osteoporosis is considered one of the potentially serious side effects of heparin therapy. The occurrence of heparin-induced osteoporosis appeared to be strictly related to the length of treatment (over 4-5 months), and the dosage (15,000 U or more daily), but the pathogenesis is poorly understood. It has been suggested that heparin could cause an increase in bone resorption by increasing the number of differentiated osteoclasts, and by enhancing the activity of individual osteoclasts. Hyperthyroidism is frequently associated with loss of trabecular and cortical bone; the enhanced bone turnover that develops in thyrotoxicosis is characterized by an increase in the number of osteoclasts and resorption sites, and an increase in the ratio of resorptive to formative bone surfaces, with the net result of bone loss. Despite these findings, the occurrence of pathological fractures in patients with hyperthyroidism is relatively low, and probably due to the fact that deficiencies in bone mass may be reversed by treatment of the thyroid disease. Most, but not all, studies on insulin-dependent diabetes mellitus (IDDM) report an association with osteopenia. In IDDM, the extent of bone loss is usually slight, which helps explain the discrepancy between the frequency of decreased bone mineral density, and the frequency of osteoporotic fractures in long-standing diabetes. Contradictory results have been obtained in non-insulin-dependent diabetes mellitus (NIDDM) patients. Increased rates of bone loss at the radius and lumbar spine were demonstrated either in patients with two-thirds gastric resection and Billroth II reconstruction, or in those with one-third resection and Billroth I anastomosis, and the metabolic bone disease following gastrectomy may consist also of osteomalacia or mixed pattern of osteoporosis-osteomalacia, with secondary hyperparathyroidism. Miscellaneous causes of secondary osteoporosis are also immobilization, pregnancy and lactation, and alcohol abuse.

Adult↗
PubMed1998

Bisphosphonates and osteoporosis treatment in Italy.

A treatment against osteoporosis can be considered efficacious only when its beneficial effects on bone remodeling, bone mass, and osteoporotic fracture incidence are proven. As for any treatment, proven efficacy must be combined with proven safety. This review analyzes published data on efficacy and safety of alendronate, clodronate and etidronate, the bisphosphonates currently marketed in Italy for osteoporosis treatment. Different studies have shown that alendronate, clodronate and etidronate reduce bone turnover, and increase bone mineral density in postmenopausal osteoporotic patients. Prospective, double blind, multicenter studies reported a reduction in osteoporotic fracture incidence for alendronate and etidronate. Fracture incidence reduction by clodronate, on the other hand, was shown only in an open label study. Finally, a reduction in fracture incidence by etidronate was shown in a large retrospective postmarketing study. Postmarketing surveillance evidenced that osteomalacia, a suspected side effect of etidronate treatment, does not occur at the currently used dose regimens. Postmarketing surveillance of alendronate has recently raised some concern regarding possible severe esophageal damage during alendronate treatment, especially when the drug is not taken according to the manufacturer's instructions.

Aged↗
PubMed1998

Usefulness of ultrasound in Sudeck's atrophy of the foot.

Quantitative ultrasound (QUS) of bone has been proposed as an inexpensive and radiation-free device method of assessing skeletal status. QUS has been widely used in the assessment of osteoporosis. Until now only few data are available on the usefulness of QUS in different disorders, such as Sudeck's atrophy. To evaluate the ability of QUS in the diagnosis and monitoring of regional osteoporosis, we investigated 19 patients (12 women and 7 men, age range 30-65 years) with osteoporosis of the foot (Sudeck's atrophy), as evidenced by X-ray study and Technetium-99 bone scan. In all patients we measured speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness of the calcaneus using Lunar Achilles Ultrasound, both in the affected and unaffected foot. Bone mineral density at the lumbar spine, by DXA (Hologic QDR 1000), was also performed. QUS was repeated after 3 and 6 months of treatment with salmon calcitonin (100 IU I.M. every second day). At baseline, SOS, BUA, and stiffness, expressed as T-score, were -1.9, -2.4, and -2.4 in unaffected feet and -2.9, -5.1, and -4.3, respectively, in affected feet. The difference between the unaffected and affected foot was significant for SOS, BUA, and stiffness (P < 0.001). No significant difference was found in QUS parameters in the unaffected foot during the study period. After 3 and 6 months of treatment, SOS increased in the affected foot by 0.2% and 0.3%, BUA increased by 6. 2% and 8.2%, and stiffness by 7.5% and 11.1%, respectively. In conclusion, BUA and stiffness seem to be influenced more than SOS by Sudeck's atrophy; QUS, namely, BUA and stiffness, significantly increase with calcitonin treatment. In conclusion, QUS is a sensitive tool in the diagnosis of Sudeck's atrophy of the foot and is adequate for measuring improvement in bone status following treatment.

Adult↗
PubMed1998

Age-related decline of bone mass and intestinal calcium absorption in normal males.

Although about 25% of all hip fractures occur in men, little is known about the pattern of their age-related bone loss and its main determinants. The aim of this cross-sectional study was to evaluate the age-related changes of intestinal calcium absorption, bone mass, and bone turnover in normal men. In 70 normal males (age 17-91 years), we measured spinal and forearm bone density (FBD) (by DXA), fractional intestinal calcium absorption (by oral test), serum immunoreactive parathyroid hormone (PTH), dietary calcium intake (diet records), biochemical markers of bone turnover (serum alkaline phosphatase (ALP), osteocalcin, urine calcium, creatinine, and hydroxyproline), and 1,25(OH)2D3 serum levels. Vertebral bone density (VBD) showed a modest decline before age 50 and a greater decline after age 50, whereas FBD presented a significant decrease with advancing age starting at age 40, suggesting a predominant age-related cortical bone loss. Intestinal calcium absorption (47CaFA) and serum 1,25(OH)2D3 also presented an age-related decline similar to FBD. Simple correlation analysis revealed that age was significantly related to 47CaFA (r = 0.60), calcium intake (r = 0.32), VBD and FBD (r = 0.79 and 0.63, respectively), serum 1,25(OH)2D3 (r = 0.69), and serum iPTH (r = 0.72). No significant correlation was found between age and biochemical markers of bone remodeling. Partial correlation and stepwise variable selection analyses, using 47CaFA and bone mass as dependent variables, showed that in normal males, serum 1,25(OH)2D3 and dietary calcium intake were the main contributors (64%) to 47CaFA variability, whereas only age accounted for 63% of VBD and age and dietary calcium accounted for 45% of FBD variability. These results indicate that bone loss in men accelerates after age 50 years and that among other factors, intestinal calcium malabsorption and 1,25(OH)2D3 serum levels play a role.

Adolescent↗