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Biomedical subjects

L Martelli

Publications and source records attributed to L Martelli.

At least 19 recordsLinked to original sources
PubMed2004

Lack of evidence for mutations or deletions in the CDKN2A/p16 and CDKN2B/p15 genes of Brazilian neuroblastoma patients.

Neuroblastoma, the most common extracranial tumor in childhood, has a wide spectrum of clinical and biological features. The loss of heterozygosity within the 9p21 region has been reported as a prognostic factor. Two tumor suppressor genes located in this region, the CDKN2B/p15 and CDKN2A/p16 (cyclin-dependent kinase inhibitors 2B and 2A, respectively) genes, play a critical role in cell cycle progression and are considered to be targets for tumor inactivation. We analyzed CDKN2B/p15 and CDKN2A/p16 gene alterations in 11 patients, who ranged in age from 4 months to 13 years (male/female ratio was 1.2:1). The most frequent stage of the tumor was stage IV (50%), followed by stages II and III (20%) and stage I (10%). The samples were submitted to the multiplex PCR technique for homozygous deletion analysis and to single-strand conformation polymorphism and nucleotide sequencing for mutation analysis. All exons of both genes were analyzed, but no deletion was detected. One sample exhibited shift mobility specific for exon 2 in the CDKN2B/p15 gene, not confirmed by DNA sequencing. Homozygous deletions and mutations are not involved in the inactivation mechanism of the CDKN2B/p15 and CDKN2A/p16 genes in neuroblastoma; however, these two abnormalities do not exclude other inactivation pathways. Recent evidence has shown that the expression of these genes is altered in this disease. Therefore, other mechanisms of inactivation, such as methylation of promoter region and unproperly function of proteins, may be considered in order to estimate the real contribution of these genes to neuroblastoma genesis or disease progression.

Adolescent↗
PubMed2004

Is MUC1 polymorphism associated with female infertility?

The transmembrane mucin glycoprotein (MUC1) has an anti-adhesive role, and functions to maintain a non-receptive uterine state. A polymorphic variation of the MUC1 gene has been associated with female infertility due to suspected failure of embryo implantation, based on the significant greater size of the lower allele observed in infertile women. The aim of this study was to confirm this preliminary observation using long polymerase chain reaction (PCR), which has amplified the 60-bp polymorphic variable number of tandem repeat (VNTR) associated to the binding domain of the MUC1 glycoprotein. DNA samples were obtained from 20 women, 10 fertile and 10 infertile, and the VNTR region was amplified through a long PCR procedure. The VNTR size range from 1.6 to 2.9 kb (22-44 motifs). The average size for the lower allele was 1.69 kb for both groups, and for the upper allele was 2.35 and 2.49 kb (P > 0.05) for fertile and infertile groups respectively. The VNTR polymorphism of the MUC1 gene was not associated with female infertility, although its significance cannot be discarded. It is suggested that other regulatory molecules and signals may interact with the MUC1 gene variations, favouring endometrial receptivity and embryo attachment.

Alleles↗
PubMed1998

Three new cases of spondylocarpotarsal synostosis syndrome: clinical and radiographic studies.

Spondylocarpotarsal synostosis syndrome (SSS) or congenital synspondylism is a recently delineated clinical entity. At least 15 patients have been reported. We present 3 new patients, 2 of whom were sibs born to first-cousin parents. All of our patients had multiple synostoses involving cervical, thoracic and/or lumbar vertebral bodies and carpal/tarsal bones, scoliosis/lordosis, and short stature. Sensorineural deafness was found in 2 of the 3 patients. Analysis of clinical manifestations suggests clinical variability and genetic heterogeneity in SSS. Of a total of 18 SSS patients, 10 were five pairs of sibs from five families, with first-cousin consanguinity of parents in 3, indicating that at least one type of SS is an autosomal-recessive disorder.

Abnormalities, Multiple↗
PubMed1997

[Pharmaco economics aspects of antibiotic therapy for AIDS patients in department of infectious disease].

The financial budget for public health care in Italy has been more and more restricted in the last few years, but, on the other hand, the care of AIDS patients is still very expensive and antibiotic therapy plays an important role in the management and cost of these patients. The antibiotic therapies and related costs have been evaluated in 99 patients affected by AIDS (59 pts), ARC (28 pts) or HIV serum positive (12 pts), all hospitalized or treated in Day Hospital for different bacterial infections in 1995 at the Department of Infectious Diseases, Ospedale Maggiore, Bologna, for a total of 7733 days of antibiotic therapy. The average cost for antibiotic therapy was about 400,000 Italian Lira, with no significant difference depending on the stage of HIV related disease. The crude cost for antibiotic treatment was not particularly high, but the high frequency of adverse events, registered in these patients, required additional medical support and/or a prolonged hospital stay, which increased substantially the total cost of management of bacterial infections.

English Abstract↗
PubMed1996

SRY-negative true hermaphrodites and an XX male in two generations of the same family.

Two 46,XX true hermaphrodites and one XX male without genital ambiguities are reported. They coexist in two generations of the same pedigree, with paternal transmission and in the absence of SRY (sex-determining region, Y chromosome). These familial cases provide evidence to support the hypothesis that these disorders are alternative manifestations of the same genetic defect, probably an autosomal dominant mutation (with incomplete penetrance) or an X-linked mutation (limited by the presence of the Y chromosome).

Adult↗
PubMed1996

An expert system based on causal knowledge: validation on post-cardiosurgical patients.

A new expert system for the analysis of post-cardiosurgical patients in Intensive Care Units is described, and a preliminary validation performed. The inference engine employs a hybrid reasoning method which integrates quantitative and qualitative simulation techniques in an original manner. The long-term knowledge consists of a causal network which reproduces the main relationships between physiological quantities involved in the course after cardiac surgery. Emphasis has been given to respiratory and metabolic, as well as cardiovascular quantities both in the systemic and pulmonary circulations. Preliminary system validation has been performed on a set of 40 cardiosurgical patients, previously classified either at normal-risk (17 patients) or at high-risk (23 patients) by means of statistical classification techniques. In most cases, predictions of the expert system substantially agree with those provided by the more traditional statistical method. The system, however, is also able to furnish detailed explanations on the possible physiological causes responsible for the patient status. In particular, simulation results indicate that a reduction in the cardiac index (19 cases) and an increase in the oxygen utilization coefficient (19 cases) are the most critical alterations in the high-risk patients. The system imputes the reduced cardiac index to a rise in total systemic resistance (15 high-risk patients), a decrease in cardiac strength (2 high-risk patients) or an insufficient filling volume of the systemic circulation (4 high-risk patients). Furthermore, in 6 high-risk patients the depressed cardiac outflow occurs with a reduction in the arterial oxygen content, mainly imputable to an insufficiency of blood hemoglobin content. Finally, two examples of the complete expert system explanatory capabilities are shown with reference to a pair of high-risk patients and discussed.

Blood Circulation↗
PubMed1995

[Role of slime in the pathogenesis of pulmonary infections].

Microorganisms have proved to produce an amorphous substance that adheres to surfaces of several medical devices like intravenous catheters and endotracheal tubes. We investigated the presence of slime in endotracheal tubes in our Intensive Care Unit (ICU) in 12 patients. We found in this study no correlation between the strain of bacteria on the surface of endotracheal devices and those responsible for pneumonia.

Adult↗
PubMed1994

Migrating motor complex recorded spontaneously and induced by motilin and erythromycin in an ex vivo rabbit intestinal preparation.

We investigated basal motility and the motor effects of motilin, erythromycin, and prostigmine on segments of rabbit gastrointestinal tract removed from extrinsic neural and vascular pathway and immersed in an oxygenated organ bath. Motility was recorded by means of four strain gauges sutured on the serosal surface of the segment. During basal recording, clusters of duodenal contractions that propagated distally, resembling phase III activity of migrating motor complex, were seen. Motilin (10(-6) M) and erythromycin (10(-6) M) induced a propagated cluster of contractions similar to the phase III recorded during the basal period. Prostigmine (10(-6) M) induced a simultaneous increase in gastric and small intestinal motility. Atropine (10(-5) M) prevented the motor effect of motilin, erythromycin, and prostigmine. Thus, MMCs do not appear to require central input for initiation and propagation. Motilin and erythromycin stimulate MMCs through an enteric cholinergic mechanism; therefore, the previously reported smooth muscle receptors for both substances were not apparent in the ex vivo preparation.

Animals↗
PubMed1993

Prenatal diagnosis of Charcot-Marie-Tooth disease type 1A by multicolor in situ hybridization.

Genetic heterogeneity within the most common genetic neuropathy, Charcot-Marie-Tooth disease (CMT) results in about 70% slow nerve conduction CMT1 and 30% normal nerve conduction CMT2. Autosomal dominant CMT1A on chromosome 17p11.2 represents about 70% of CMT1 cases and about 50% of all CMT cases. Three different size CMT1A duplications with variable flanking breakpoints were characterized by multicolor in situ hybridization and confirmed by pulsed field gel electrophoresis and quantitative polymerase chain reaction (PCR) amplification. These different size duplications result in the same CMT1A phenotype confirming that trisomy of a normal gene region results in CMT1A. The smallest duplication does not include the 409 locus used previously to screen for CMT1A duplications. Direct analysis of interphase nuclei from fetuses and at-risk patients by multicolor in situ hybridization to a commonly duplicated CMT1A probe is informative more often than polymorphic PCR analysis, faster than pulsed field gel electrophoresis (PFGE), and faster, more informative, and more reliable than restriction enzyme analysis. CMT1B restriction enzyme analysis of CMT pedigrees without CMT1A is expected to diagnose another 8% of at-risk CMT1 patients (total: 78%).

Amniocentesis↗
PubMed1992

Urinary excretion of thromboxane and prostacyclin metabolites during chronic low-dose aspirin: evidence for an extrarenal origin of urinary thromboxane B2 and 6-keto-prostaglandin F1 alpha in healthy subjects.

In vivo biosynthesis of thromboxane and prostacyclin is currently evaluated by measuring urinary excretion of selected metabolites. Urinary thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) (non-enzymatic hydrolysis products of thromboxane and prostacyclin) are thought to derive from renal biosynthesis of the parent compounds, while enzymatic metabolites such as 2,3-dinor-TXB2 and 2,3-dinor-6-keto-PGF1 alpha appear to be mainly derived from systemic (platelet) thromboxane and (vascular) prostacyclin, respectively. Using immunoaffinity extraction and high-resolution gas chromatography-negative ion chemical ionization mass spectrometry (HRGC-NICIMS), we measured the paired excretion of non-enzymatic and enzymatic metabolites of thromboxane and prostacyclin in healthy subjects before, during and after an eight-day schedule of oral low-dose aspirin (30 mg/day), a treatment known to inhibit platelet and perhaps vascular but not renal cyclooxygenase. Low-dose aspirin cumulatively reduced urinary excretion of TXB2 and 2,3-dinor-TXB2 (about 80% inhibition on day 8 of aspirin treatment, P less than 0.01), as well as 6-keto-PGF1 alpha and 2,3-dinor-6-keto-PGF1 alpha (about 45% inhibition on day 8 of aspirin treatment, P less than 0.01). Excretion of all metabolites recovered slowly after aspirin withdrawal. Urinary PGE2, taken as an index of renal cyclooxygenase activity, was not inhibited by aspirin. A highly significant correlation was found between paired excretion values of non-enzymatic vs. enzymatic metabolites of thromboxane and prostacyclin in all individuals studied (TXB2 vs. 2,3-dinor-TXB2 (r = 0.91 +/- 0.03); 6-keto-PGF1 alpha vs. 2,3-dinor-6-keto-PGF1 alpha (r = 0.92 +/- 0.06], irrespective of aspirin treatment. TXB2/2,3-dinor-TXB2 and 6-keto-PGF1 alpha/2,3-dinor-6-keto-PGF1 alpha mean ratios remained unchanged throughout the experiment. These data do not support the view that urinary TXB2 and 6-keto-PGF1 alpha derive mainly from renal biosynthesis in healthy subjects, but rather suggest that they may represent a fraction of systemic (platelet) thromboxane and (vascular) prostacyclin escaping metabolism. These data also suggest that chronic low-dose aspirin may partly inhibit vascular prostacyclin in addition to platelet thromboxane biosynthesis.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

[Echography and venous pathology].

When performed by a well-trained operator, ultrasonic exploration of the deep veins has a more than 90% sensitivity and specificity in the diagnosis of deep vein thrombosis. Despite technical problems in the ileal and sural regions, it is the first examination to be carried out in patients with clinical signs of venous thrombosis. In distal thrombosis of the leg and calf ultrasonography might even be more sensitive than phlebography. In superficial phlebitis ultrasounds can be used to evaluate the extent of thrombosis. In varicose vein disease, they are also a crucial element in the choice of treatment.

Humans↗
PubMed1990

[Thrombosis of the gastrocnemic veins. A clinical entity].

Among deep venous thromboses of the calf, isolated gastrocnemic vein thrombosis is a rare condition. Its main characteristics could be extracted from 5 cases. Following a positional or mechanical triggering factor, the diagnosis is suggested by pain localized to the calf. Ultrasonography shows the intraluminal thrombus better than phlebography, since the gastrocnemic veins, which bypass the larger deep veins, can be opacified only after a garrot is placed above the knee. The thrombus may extend to the popliteal vein, with a risk of pulmonary embolism and post-phlebitis disease. Treatment consists of anticoagulants and elastic bandage.

4-Hydroxycoumarins↗
PubMed1989

Prostaglandin and thromboxane synthesis by human intracranial tumors.

Prostaglandin (PG) and thromboxane (TX) production by homogenates of human intracranial tumors (33 gliomas, 32 meningiomas, six brain metastases) and "normal" brain (n = 26) from tumor-bearing patients was studied. PGF2 alpha, PGE2, PGD2, 6-keto-PGF1 alpha (the hydrolysis product of PGI2) and TXB2 (the hydrolysis product of TXA2) were determined by high-resolution gas chromatography-mass spectrometry after ex vivo metabolism of endogenous arachidonic acid. Prostanoid profiles (relative abundance of each metabolite) were different for gliomas and meningiomas, but similar for gliomas and their nontumoral counterpart, i.e., "normal" brain. Mean overall prostanoid production was significantly higher in gliomas (539 +/- 95) and meningiomas (523 +/- 69) than in "normal" brain (198 +/- 23). Prostanoid synthesis significantly increased with anaplastic grade (glioblastomas greater than anaplastic astrocytomas greater than slow-growing astrocytomas greater than "normal" brain), while profiles did not substantially change (TXB2 was the most and 6-keto-PGF1 alpha the least abundant product). Meningioma profiles showed no marked prevalence of any particular metabolite and no major differences between histological subgroups. All brain metastases from different carcinomas (n = 5) showed a prevalence of TXB2 and PGE2 and very low PGD2 synthesis.

Arachidonic Acid↗
PubMed1975

[Behaviour of blood digoxin, determined by the radioimmunity method, in patients with renal failure (author's transl)].

The authors used radioimmunity to study blood digoxin behaviour in patients with normal renal function and with variable BUN. The computerized and mathematically considered data showed that digitalic intoxication occurs with higher digoxin blood levels in patients with renal failure than in normal renal function cases. In the first case, moreover, it occurs sooner than in the second one, and the total digoxin dose is smaller than in normal patients. We have found that the large range of digosin blood levels is vital in deciding the therapeutic and toxic dose; that may be done, for most cases, following the estimate of the theoretical saturation dose using our method.

Aged↗