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Biomedical subjects

G Martini

Publications and source records attributed to G Martini.

At least 91 records · Page 5Linked to original sources
PubMed1994

Favourable results of treatment of narrowed saphenous vein grafts with Palmaz-Schatz stent implantation.

Although conventional balloon angioplasty of saphenous vein grafts can be performed with an acceptable acute success and complication rate, restenosis remains a major problem. However, this may be overcome by the implantation of Palmaz-Schatz stents. Palmaz-Schatz stent deployment was performed in our institution in 43 patients who were referred for PTCA of stenosed saphenous vein grafts. Thirty-seven were located at the mid-portion of the graft, seven at the ostium and six at the distal anastomosis. Overall, we used 59 standard length (15 mm) Palmaz-Schatz stents and 22 short (7 mm) stents. In 15 lesions (30%) multiple stents were implanted in tandem to treat diffuse disease. Angiographic success was achieved in 47 of the 50 attempted lesions (94%). Major cardiac complications occurred in three patients. Two patients had procedures complicated by the development of a Q wave myocardial infarction, one of whom underwent urgent CABG. One patient died. There was no episode of subacute thrombosis. The angiographic follow-up of 37 lesions (80% of eligible lesions) at a mean time of 5 +/- 2 months (range 1-8) showed a restenosis rate of 11% and residual post-stent diameter stenosis was associated with a significantly higher restenosis rate. However, no restenosis occurred in lesions receiving multiple stents. Clinical follow-up was performed in all patients, and at a mean of 25 months after the procedure, 64% were free from clinical events, including recurrent angina. Palmaz-Schatz stent implantation is an effective and safe procedure to treat narrowed vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Preliminary experience with intravascular ultrasound guided Palmaz-Schatz coronary stenting: the acute and short-term results on a consecutive series of patients.

The purpose of this study was to prospectively test the hypothesis that systemic anticoagulation is not needed following coronary stenting when adequate stent expansion is achieved and documented and other flow limitations eliminated. Intravascular ultrasound (IVUS) was used to confirm adequate stent expansion, which was defined as good plaque compression together with the achievement of an intrastent lumen cross-sectional area (CSA) that was greater than 40% of the average reference vessel CSA. In this prospective study, Palmaz-Schatz coronary stenting was performed on 343 lesions in 263 consecutive patients. Primary stenting was successful in 254 patients (96.6%) and 332 lesions (96.8%). All patients with successful primary stenting underwent IVUS imaging except nine patients (13 lesions) that did not have an IVUS evaluation for technical reasons and three patients (4 lesions) in which IVUS was unsuccessful. The initial IVUS performed after achieving an acceptable angiographic result revealed inadequate stent expansion in 191 patients (79%) and 244 lesions (77%). After further dilatation, final adequate stent expansion was accomplished in 230 patients and 301 lesions. These patients were treated with Ticlopidine 250 mg twice per day for 2 months and did not receive postprocedure anticoagulation. There was one acute stent thrombosis (0.3%) that occurred in a lesion with slow flow and an inadequately expanded stent. There was no subacute stent thrombosis and no bleeding or vascular complications. We conclude that when adequate stent expansion is achieved and confirmed and other flow limiting lesions eliminated, that systemic anticoagulation after the stent procedure is not necessary.

Aged↗
PubMed1994

Management of osteoporosis and Paget's disease. An appraisal of the risks and benefits of drug treatment.

Osteoporosis is a major public health problem occurring primarily among the postmenopausal population. Osteoporosis is a preventable disease, but despite several advances in its prevention, treatment of the established disease to date remains a major challenge to be managed by primary care physicians. Stabilisation of bone mass and prevention of falls are of paramount importance in any therapeutic programme for osteoporotic patients with established vertebral fractures. Drug therapy for osteoporosis can be divided operationally into 2 main categories: those that inhibit bone resorption, and thus reduce bone turnover, and those that stimulate bone formation, exerting an anabolic effect. Therapeutic agents that inhibit bone remodeling would appear to be best suited to those patients with high turnover osteoporosis (about 30%). Included in this category are calcium, vitamin D and its metabolites, gonadal steroids, calcitonin, ipriflavone and bisphosphonates. Although estrogen replacement therapy has been proven to be effective in older females, calcitonin appears to be the treatment of choice for this population since it stabilises or increases bone mass and also has reported analgesic properties. Drugs that stimulate bone remodeling or bone formation would be best suited to patients with low turnover osteoporosis (about 70%). The agent in this class that is widely used is sodium fluoride. New therapies include intermittent injections of synthetic parathyroid hormone, and cyclic bisphosphonates to activate then depress resorption and formation. Any attempts to stabilise the skeleton with any drug regimen must be accompanied by an adequate calcium supply, i.e. 1200 to 1500 mg/day). The theoretical basis of tailoring treatment for osteoporosis to the underlying histology has not yet been fully proven, but there is increasing experimental support to this approach. Drugs that inhibit bone turnover, such as calcitonin, appear to be effective in increasing bone mass for 1.5 to 2 years, about the time it would take to replenish the remodeling space in a patient with high turnover osteoporosis. In contrast, although bone mass appears to increase for as long as 5 years in patients treated with sodium fluoride, there has been no consistent reduction in occurrence of vertebral or hip fractures. Paget' disease of bone is a focal disorder of the skeleton characterised by excessive resorption and subsequently disorganised formation of bone. The aetiology of the disease is unknown. Paget's disease may be mono-ostotic or polyostotic; pain and bone deformities due to enlargement of skeletal segments represent the main clinical aspects. However, in many patients the disease may be asymptomatic.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Development↗
PubMed1993

On the parental origin of the X's in a prenatally diagnosed 49,XXXXX syndrome.

A 49,XXXXX fetus was detected in amniotic fluid cell cultures from a 39-year-old mother. On ultrasonography, growth retardation and bilateral radioulnar synostosis were found. Additional clinical manifestations were mild facial anomalies and hypoplastic ovaries depleted of oocytes. Molecular analysis showed that this aneuploidy arose by successive maternal non-disjunction.

Adult↗
PubMed1993

G6PD haplotypes spanning Xq28 from F8C to red/green color vision.

The most telomeric region of the human X chromosome within band Xq28 consists of a gene-rich region of about 3 Mb which contains the genes for coagulation factor VIIIc, glucose-6-phosphate dehydrogenase (G6PD), and red/green color vision. We have studied five polymorphic sites from this region, in a sample of normal people from the Cosenza province of Southern Italy. These sites, which span a distance of some 350 kb, are in strong linkage disequilibrium. Of the 32 possible haplotypes only 10 were found, and 4 of these account for 80% of all X chromosomes analyzed. In addition, we found that all G6PD-deficient people with the G6PD Mediterranean mutation belong to only two haplotypes. One of these (Med 1) is found only within a small subregion of the area investigated, west of the Appennine mountain range. Most remarkably, all Med 1 G6PD-deficient individuals also had red/green color blindness. The more frequent haplotype (Med 2) is the same in Calabria and in Sardinia, where it accounts for about 90% of the G6PD Mediterranean mutations, despite the fact that gene flow between the populations of Sardinia and Southern Italy must have been limited. These data do not enable us to determine whether the two types of G6PD Mediterranean have arisen through two separate identical mutational events or through a single mutational event followed by recombination. However, the data indicate relatively little recombination over an extended region of the X chromosome and they suggest that the G6PD Mediterranean mutation is recent by comparison to the other polymorphisms investigated.

Adult↗
PubMed1993

Enhanced activity of human G6PD promoter transfected in HeLa cells producing high levels of HIV-1 Tat.

Glucose 6-phosphate dehydrogenase (G6PD) enzyme activity has an important role in the cell defence against oxidative damage produced by hydrogen peroxide, a compound known to activate HIV-1 expression through the intermediate of NF-kappa B. By means of CAT assays, in this paper we show that the Tat protein increases the rate of transcription from the human G6PD promoter in HeLa cells; furthermore, we report a similar effect of Tat on transcription driven from the viral RSV promoter. We did not observe Tat stimulation with the human CMV, SV40 or the basic RSV promoters. Dose-response curves indicate that Tat activates G6PD and RSV through a mechanism different from the major one operating on the HIV-1 LTR promoter. TAR-like structures are not involved, instead a short sequence close to the G6PD transcription start site and the RSV LTR enhancer is a good candidate for mediating the phenomena described in this paper. This sequence has some features in common with the NF-kappa B motif.

Base Sequence↗
PubMed1993

Effects of age and menopause on bone density of entire skeleton in healthy and osteoporotic women.

We studied 885 women to evaluate the effects of age and menopause on bone mineral density (BMD) in both healthy and postmenopausal osteoporotic subjects. The study cohort consisted of 161 healthy premenopausal women (age range 25-54 years), 357 healthy postmenopausal women (35-85 years) and 367 osteoporotic women (41-87 years). Total body and regional (spine, trunk, pelvis, arms, legs) BMD were measured with a dual-energy X-ray (DXA) device (Lunar DPX). Premenopausal BMD values remained essentially unchanged until the first half of the fourth decade, when they decreased. BMD values in both healthy postmenopausal and osteoporotic women were significantly lower than premenopausal values, and continued to decrease statistically after the onset of menopause. The highest Z-score (0.96 +/- 0.92) was found for total body BMD. Higher T-score values were found in osteoporotic than in normal postmenopausal women. In both healthy and osteoporotic postmenopausal women the best fits for BMD changes in total body, spine, trunk, arms and legs were obtained with the natural logarithm of years since menopause; only the pelvis BMD decreased linearly. Multiple regression analysis indicated that postmenopausal BMD changes in both normal and osteoporotic women were linked chiefly to body weight and years since the onset of menopause.

Adult↗
PubMed1993

Surgical repair of an anterior tibialis muscle hernia with Mersilene mesh.

The most frequent muscle hernia of the lower extremities is the anterior tibialis muscle hernia. A number of surgical procedures are available for the treatment of symptomatic anterior tibialis muscle hernias. However, in case of a large fascial defect, their use may be unfeasible or inconvenient. Moreover, current surgical procedures are prone to the risk of an anterior tibial compartment syndrome. The use of a synthetic patch could provide an alternative, particularly for large defects. In this paper we report the repair of a large, symptomatic, long-standing anterior tibialis muscle hernia with polyester mesh (Mersilene) fixed to the edges of the defect (muscular fascia and tibial periosteum). This simple procedure provided excellent functional results and a good cosmetic appearance without complications and sequelae.

Adult↗
PubMed1993

Total body, spine, and femur dual X-ray absorptiometry in spinal osteoporosis.

The aim of this study was to evaluate the ability of dual x-ray absorptiometry (DXA) to discriminate between normal and osteoporotic patients. A total of 152 postmenopausal women entered the study: 73 (aged 61.2 +/- 8 years) had established postmenopausal osteoporosis with one or more vertebral crushes on lateral X-ray of spine, and 79 (aged 59.3 +/- 7.8 years) had no vertebral fractures. Measurements of bone mineral content (BMC) in grams, bone mineral density (BMD) in g/cm2 and body composition (lean and fat mass in grams) of total body, lumbar spine (L2-L4), and femur (neck, trochanter, Ward's triangle) were carried out with a LUNAR DPX densitometer. In all sites, BMD values of osteoporotic patients were significantly lower than those of the control subjects. The higher Z-score was found for total body density (-2.14) followed by L2-L4 (-2.0), femoral neck (-1.93), Ward's triangle (-1.69), and trochanter (-1.4). Only the trochanter Z-score was significantly different compared with the other sites. A fracture threshold was determined for each site from osteoporotic patients and normal controls: with a sensitivity set at 90%, the best specificity was obtained at the lumbar spine and total body sites (89% and 84%, respectively). BMD values were highly related to lean and fat body mass, but bone loss with age was unrelated to soft tissue change. In conclusion, BMD measurements at different skeletal sites enable detection of spinal osteoporosis although sensitivity for femoral areas was less with respect to total body and L2-L4 BMD values.

Absorptiometry, Photon↗
PubMed1993

Genetic heterogeneity of glucose-6-phosphate dehydrogenase deficiency revealed by single-strand conformation and sequence analysis.

We have carried out a systematic study of the molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency on a sample of 53 male subjects from Calabria, in southern Italy. Our sequential approach consisted of the following steps: (1) Partial biochemical characterization was used to pinpoint candidate known variants. The identity of these was then verified by restriction-enzyme or allele-specific oligonucleotide hybridization analysis of the appropriate PCR-amplified fragment. (2) On samples for which there was no obvious candidate mutation, we proceeded to amplify the entire coding region in eight fragments, followed by single-strand conformation polymorphism (SSCP) analysis of each fragment. (3) The next step was M13 phage cloning and sequencing of those individual fragments that were found to be abnormal by SSCP. Through this approach we have identified the molecular lesion in 51 of the 53 samples. In these we found a total of nine different G6PD-deficient variants, five of which (G6PD Mediterranean, G6PD A-, G6PD Coimbra, G6PD Seattle, and G6PD Montalbano) were already known, whereas four are new (G6PD Cassano, G6PD Cosenza, G6PD Sibari, and G6PD Maewo). G6PD Mediterranean is the commonest variant, followed by G6PD Seattle. At least seven of the variants are present, at polymorphic frequencies, in the Calabria region, and some have a nonrandom distribution within the region. This study shows that the genetic heterogeneity of G6PD deficiency in Calabria, when analyzed at the DNA level, is even greater than had been anticipated from biochemical characterization. The sequential approach that we have followed is fast and efficient and could be applied to other populations.

Base Sequence↗
PubMed1992

Measurements of bone mineral density by DXA total body absorptiometry in different skeletal sites in postmenopausal osteoporosis.

In order to evaluate the bone mineral density (BMD) of the entire skeleton and its major anatomical areas, total body DXA absorptiometry was performed in 330 postmenopausal women whose ages ranged from 42-85 years. Sixty-three of them were normal women and constituted the control group (Group 1). Two hundred sixty-seven were patients affected with postmenopausal osteoporosis: 107 osteoporotic patients had vertebral biconcavity deformities of grade 1 (Group 2), and the other 160 had vertebral wedge, biconcavity, and compression deformities of grade 2 (Group 3). Total body absorptiometry was assessed by a DXA system (Lunar DPX). Significant reduction in total body BMD values was observed in patients in Groups 2 and 3 (p less than 0.01): the bone loss was more intense in osteoporotic women of Group 3. The low values of the BMD in osteoporotic patients are, moreover, localized in the areas of spine, arms, and legs; the osteopenia was particularly enhanced in patients with grade 2 vertebral deformities. Multiple linear regression indicated that values of total BMD were significantly related to age and BMI. Receiver operating characteristic (ROC) analysis showed that total BMD provided high sensitivity: At 90% of specificity it was 78% for Group 2 and 89% for Group 3. DXA total body absorptiometry has demonstrated that, in postmenopausal osteoporotic women, the reduction in bone mass is not localized only in the spine, but also involves the appendicular skeleton.

Absorptiometry, Photon↗
PubMed1992

Molecular basis of chronic non-spherocytic haemolytic anaemia: a new G6PD variant (393 Arg----His) with abnormal KmG6P and marked in vivo instability.

More than 80 genetic variants of glucose-6-phosphate dehydrogenase (G6PD) are associated with chronic non-spherocytic haemolytic anaemia (CNSHA). In order to help clarify the molecular basis of this association, we have carried out a detailed biochemical and genetic characterization of two G6PD deficient brothers affected by CNSHA. The G6PD from the two patients has altered electrophoretic mobility, abnormally elevated Michaelis constant (Km) for G6P, and extreme instability in vivo and in vitro. By comparison with published information we found that this is a new G6PD variant which we have designated G6PD Portici. The entire coding region of the gene has been sequenced, and a single point mutation, a G----A transition, was found at position 1178 in exon X, causing a substitution of histidine for arginine at residue 393 in the polypeptide chain. By polymerase chain reaction (PCR) amplification followed by diagnostic restriction enzyme analysis and allele-specific oligonucleotide hybridization we have demonstrated the inheritance of this mutation in the patient's family. Our results support the notion of a causative link between this mutation in the G6PD gene and CNSHA. Our data, in combination with previous data in the literature, suggest that the three-dimensional structure of G6PD is such as to cause interaction in the binding of its two substrates, G6P and NADP.

Adolescent↗
PubMed1992

Metabolic effects of rectal administration of unmodified eel calcitonin in humans.

To evaluate the metabolic effects of unmodified eel calcitonin, nine normal subjects and eleven patients with Paget's disease of the bone entered the study. Eel calcitonin was administered via rectal mucosa at the dosage of 100 and 200 MRCU. Plasma calcium, plasma phosphate and plasma cAMP were measured at a baseline and after 10, 20, 30, 60, 90, 120, 180, 240 min. Rectal administration of 100 MRCU of eel calcitonin decreased plasma calcium and phosphate levels in normal subjects; the hypocalcaemic and hypophosphatemic effects were more marked and statistically significant in Paget's disease patients. Using 200 MRCU of eel calcitonin, statistically significant reductions in plasma calcium levels were observed in controls and in Paget's disease patients. Plasma phosphate decreased after rectal administration of the hormone, but not significantly. A slight but not significant increase in plasma cAMP was observed in normal subjects after the administration of 200 MRCU. These data demonstrate that eel calcitonin administered via rectal mucosa can exert some of the known biologic effects of the peptide.

Administration, Rectal↗
PubMed1992

[Angioplasty in total occlusion of the coronary arteries: the importance of the angiographic variables].

Total coronary occlusions can be treated by coronary angioplasty with a lower success rate when compared to the angioplasty success rate of stenoses. To evaluate factors associated with successful re-opening of total coronary occlusion we evaluated 128 occlusions attempted in 120 patients. We analyzed clinical and angiographic variables. Successful re-opening was obtained in 65% of total occlusions attempted; 1 patient (0.8%) had to undergo emergency coronary artery bypass surgery. Only the morphological characteristics of the occlusions were predictive of success. When total occlusions had a tapered morphology, success was achieved in 87% of the attempts versus 50% of success without tapered morphology (p < 0.001). The success, when the occlusion was associated with the presence of bridging collaterals, was very low (present: 30% success; absent: 71% success, p < 0.005). Success for occlusions longer than 1.5 cm was lower when compared to shorter occlusions (61% vs 78%; p < 0.005). The type of occlusion (absolute, functional), the presence of a branch originating at the level of the occlusion, the duration of the occlusion, the artery and its segment were not predictive of success. Multivariate analysis showed that tapered morphology was the only variable associated with successful re-opening of a total occlusion (87% probability of success when present). We conclude that it is possible to re-open a total coronary occlusion with low complication rate and high primary success rate when careful care is applied with particular attention paid to the morphology of the occlusion.

Adult↗
PubMed1992

[Methods for measuring whole-body adipose tissue: the usefulness of "total body" X-ray densitometry].

"Total body" densitometry, which was first used to determine total-body mineral content, allows, above all in the most recent X-ray (DXA) version, an accurate study to be made of soft tissues in relation to both their adipose and nonadipose components. In addition to being used for overall evaluations, it is possible to use DXA for regional studies of body tissue distribution, thus allowing obesity to be analysed not only in quantitative but also qualitative or more specifically endocrine-metabolic terms. In comparison to other methods DXA is noninvasive, quick to use, low cost and risk free. Given its high accuracy rate it can also be used to monitor patients with demineralizing pathologies, obesity, thinness due to global and/or district edema receiving dietary and/or pharmacological treatment.

Absorptiometry, Photon↗