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Biomedical subjects

M Baldi

Publications and source records attributed to M Baldi.

At least 19 recordsLinked to original sources
PubMed2006

Markers of hypercoagulability and inflammation predict mortality in patients with heart failure.

BACKGROUND AND AIMS: Plasma levels of inflammatory markers are increased in chronic heart failure (HF) and are also subclinical indicators of future HF. Inflammation is strictly correlated with clotting activation, but the association between inflammation, hypercoagulability and prognosis in HF has not been previously reported. METHODS AND RESULTS: Markers of inflammation (interleukin-6; IL-6, and C-reactive protein; CRP) and hypercoagulability (D-dimer; DD, and thrombin-antithrombin III complex; TAT) were prospectively assessed in 214 subjects with New York Heart Association (NYHA) functional class II-IV HF. During a median follow-up of 8.5 months, 32 patients had an event: 13 died and 19 were hospitalized because of worsening of HF. IL-6, DD and TAT levels were all significantly associated with increased risk of death after adjustment for other known HF prognostic factors (age, gender, traditional cardiovascular risk factors, NYHA class, systolic left ventricular function, renal failure, hemoglobin, serum sodium) in a Cox multivariate proportional hazard model (P = 0.003, P = 0.01 and P = 0.02, respectively). When these markers were added simultaneously to the known prognostic factors in a new Cox multivariate model, only DD levels were significant predictors of mortality (hazard ratio [95% confidence interval; CI]: 11 [2.7-45.1], P = 0.001). The Kaplan-Meier curve revealed a significantly better outcome in patients with DD below 450 ng mL(-1). NT-pro-BNP was the only significant predictor of rehospitalization (HR [95% CI]: 5.3 [2.0-13.8], P < 0.001). CONCLUSION: Hypercoagulability and inflammation, as assessed by DD, TAT and IL-6 levels, are associated with an increased mortality risk in HF.

Aged↗
PubMed2005

Strategies and clinical outcome of 250 cycles of Preimplantation Genetic Diagnosis for single gene disorders.

BACKGROUND: We report on our experience with preimplantation genetic diagnosis (PGD) for single gene disorders (SGDs), from 1999 to 2004, describing strategies and overall clinical outcome of 250 cycles in 174 couples for 23 different genetic conditions. METHODS: PGD cycles included 15 for autosomal dominant, 148 for autosomal recessive and 19 for X-linked SGDs. In addition, 68 cycles of PGD for SGDs were performed in combination with HLA matching. The strategy in each case used an initial multiplex PCR, followed by minisequencing to identify the mutation(s) combined with multiplex PCR for closely linked informative markers to increase accuracy. Linkage analysis, using intragenic and/or extragenic polymorphic microsatellite markers, was performed in cases where the disease-causing mutation(s) was unknown or undetectable. RESULTS: In 250 PGD cycles, a total of 1961 cleavage stage embryos were biopsied. PCR was successful in 3409 out of 3149 (92.4%) biopsied blastomeres and a diagnosis was possible in 1849 (94.3%) embryos. Four hundred and twenty-seven embryos were transferred in 211 cycles, resulting in 71 pregnancies (33.6% per embryo transfer), including 15 biochemical pregnancies, six spontaneous miscarriages, two ectopic pregnancies, which were terminated, and nine pregnancies which are still ongoing. The remaining pregnancies were confirmed to be unaffected and went to term without complications, resulting in the birth of 35 healthy babies. CONCLUSIONS: Minisequencing for mutation detection combined with multiplex fluorescence PCR for linkage analysis is an efficient, accurate and widely applicable strategy for PGD of SGDs. Our experience provides a further demonstration that PGD is an effective clinical tool and a useful option for many couples with a high risk of transmitting a genetic disease.

Adult↗
PubMed2005

Array comparative genomic hybridization profiling of first-trimester spontaneous abortions that fail to grow in vitro.

OBJECTIVES: Cytogenetic analysis of spontaneous abortion samples can be limited by culture failure. Failure to grow in vitro has traditionally been suspected to be due to in vivo death of tissue associated with spontaneous abortion (SAB) or simply technical factors of growth in culture. METHOD: We used array comparative genomic hybridization (array CGH) to investigate chromosomal imbalances in products of conception that failed to grow in vitro. RESULTS: Our data on 26 cases of SABs that failed to grow in culture are compared and contrasted with published data on cytogenetic findings following in vitro culture. The results revealed abnormalities uncommonly seen by classic cytogenetic methods. These abnormalities include high rates of double aneuploidy and autosomal monosomy. The data taken together suggest that classic cytogenetics of spontaneous abortion may yield normal karyotypes or selected abnormal karyotypes that permit cell proliferation in vitro while Array CGH detects other abnormalities. CONCLUSION: Array CGH is becoming an important clinical assay for unbalanced chromosome abnormalities whether cells grow in culture or not and in cases of analysis on one or few cells.

Abortion, Spontaneous↗
PubMed2005

Hormonal and metabolic responses to acute ghrelin administration in patients with bulimia nervosa.

Ghrelin is generally influenced by energy balance status and is inversely associated with body mass index (BMI), being reduced in simple obesity, notable exception being Prader Willi syndrome, and elevated in several conditions of undernutrition, including anorexia nervosa (AN). Interestingly, ghrelin levels have also been found elevated in patients with bulimia nervosa (BN) in spite of normal BMI. In humans, intravenous (iv) ghrelin administration induces endocrine (increase in GH, PRL, ACTH and cortisol) and metabolic (increase in glucose and decrease in insulin) effects as well as an increase in appetite and food intake. In AN, ghrelin administration surprisingly leads to a decreased GH response and absence of glycemic variations but normal PRL, ACTH and insulin response. This pattern would reflect a decrease in sensitivity to ghrelin or, alternatively, the metabolic status of AN. To further clarify the function of ghrelin in eating disorders, the endocrine and metabolic response to acute iv ghrelin (1.0 microg/kg) was studied in seven young women with purging BN (BW, BMI, mean+/-SEM: 20.3+/-0.5 kg/m2). Circulating total ghrelin levels were also measured. The results in BW were compared to those recorded in a group of nine healthy women (HW; BMI 22.3+/-2.5 kg/m2). The GH response to ghrelin in BW overlapped with that in HW. Ghrelin administration also led to a similar increase in PRL, ACTH, cortisol and glucose levels in the two groups. Insulin levels were not significantly modified by ghrelin administration in either group. The overlapping endocrine and metabolic response to ghrelin in the two groups occurred with regard to circulating total ghrelin levels which were higher in BW than in HW. In conclusion, BN, a condition of ghrelin hypersecretion, is connoted by a normal endocrine and metabolic response to exogenous ghrelin administration.

Adrenocorticotropic Hormone↗
PubMed2005

Somatopause reflects age-related changes in the neural control of GH/IGF-I axis.

This paper will focus on the hypofunction of GH/IGF-I axis in aging, as the most impressive example of decreased activity as function of age-related changes in the neural control of somatotroph cells. GH secretion undergoes clear age-related variations that are generally mirrored by IGF-I levels, the best marker of GH status. Given the well known positive influence of GH/IGF-I on body composition, structure functions and metabolism, this paper discusses the potential clinical implications, also taking into account evidence showing that, at least in animals, deficiency in GH/IGF-I is somewhat associated to prolonged life. Although somatopause is likely to contribute to age-related changes in body composition, structure functions and metabolism, we are now in front of the paradox of lifelong GH/IGF-I deficiency or resistance resulting in prolonged life expectancy and GH replacement at advanced age, probably exerting anti-aging effects. This evidence questions whether GH deficiency is or not a beneficial adaptation to aging. By answering this question one is not simply finding new phylosophical paradigm but also the rational basis for anti-aging drug interventions.

Aging↗
PubMed2004

Development and clinical application of a strategy for preimplantation genetic diagnosis of single gene disorders combined with HLA matching.

Preimplantation HLA matching has recently emerged as a tool for couples desiring to conceive a potential donor progeny for transplantation in a sibling with a life-threatening disorder. In this paper we describe a strategy optimized for preimplantation genetic diagnosis (PGD) of haemoglobinopathies combined with HLA matching. This procedure involves a minisequencing-based genotyping of HLA regions A, B, C and DRB combined with mutation analysis of the gene regions involved by mutation. Analysis of at least eight polymorphic short tandem repeat (STR) markers scattered through the HLA complex has also been included to detect potential contamination and crossing-over occurrences between HLA genes. The above assay can also be used for preimplantation HLA matching as a primary indication. The strategy was clinically applied for HLA matching in 17 cycles (14 for beta-thalassaemia, one for Wiscott-Aldrich syndrome and two for leukaemia). A reliable HLA genotype was achieved in 255/266 (95.9%) of the blastomeres. In total, 22 (14.8%) embryos were obtained that were HLA-matched with the affected siblings, 14 (9.4%) of which were unaffected and transferred back to the patients. Four clinical pregnancies were obtained, three of which (one twin, two singletons) are ongoing and were confirmed as healthy and HLA-identical with the affected children. Minisequencing-based HLA typing combined with HLA STR haplotyping has been shown to be a reliable strategy for preimplantation HLA matching. The major advantage of this approach is that the validation of a single assay can be done once and then used for the majority of the patients, reducing notably time needed for preclinical set-up of each case.

Blastocyst↗
PubMed2004

Adrenal sensitivity to adrenocorticotropin 1-24 is reduced in patients with autoimmune polyglandular syndrome.

Autoimmune polyglandular syndromes are fairly common diseases that are classified into four constellations based on the clinical clustering of the various component diseases. In types 1, 2, and 4, primary adrenal insufficiency due to an autoimmune process is usually present, but its diagnosis is often delayed because it is difficult to detect in a subclinical phase. It is widely accepted that the classical dose of 250 microg ACTH(1-24) is supramaximal, whereas 0.06 microg has been shown to be one of the lowest ACTH doses that is able to stimulate adrenal secretion in normal young subjects. The aim of this study was to clarify the sensitivity and maximal secretory response of the adrenal gland to ACTH in a group of patients with at least two autoimmune diseases, without clinical signs and symptoms of overt or subclinical hypocortisolism. Cortisol (F), aldosterone (A), and dehydroepiandrosterone (DHEA) responses to the sequential administration of very low and supramaximal ACTH(1-24) doses [0.06 microg followed by 250 microg ACTH(1-24) i.v. at 0 and +60 min] were studied in 18 patients with at least two autoimmune diseases (AP; age, 20-40 yr; body mass index, 22-26 kg/m(2)). The results in the patients were compared with the results recorded in 12 normal age-matched control subjects (CS; age, 22-34 yr; body mass index, 20-25 kg/m(2)). At baseline, ACTH levels in AP were within the normal range but higher (P < 0.05) than in CS, whereas F, A, DHEA, urinary-free F, and plasma renin activity were similar in both groups. F, A, and DHEA responses to ACTH were dose dependent in both groups. However, in AP, F, A, and DHEA levels showed no response to the 0.06- micro g ACTH dose, which, in turn, elicited clear responses (P < 0.01) in CS. On the other hand, F, A, and DHEA responses to 250 microg ACTH in AP were not different from those in CS. In conclusion, patients with autoimmune diseases who displayed a normal basal adrenal function showed a loss of F, A, and DHEA response to the very low ACTH dose, although they were normal responders to the high ACTH dose. These data are likely to indicate that a reduced sensitivity to ACTH in all adrenal zones occurs in patients with different types of autoimmune disease.

Adrenal Cortex Function Tests↗
PubMed2003

Clinical value of preimplantation genetic diagnosis.

The clinical application of preimplantation genetic diagnosis (PGD) has provided an alternative approach for the prevention of affected pregnancies in couples at high reproductive risk. The frequent contribution of genetic factors to infertility problems makes PGD of particular value for assisted reproductive practices. In addition, the selection of euploid embryos for transfer has a strong impact on IVF efficiency as aneuploidies are the main cause of spontaneous abortions and implantation failures. In this study, the clinical outcome in PGD cycles is presented. The list of monogenic disorders for which PGD is performed is rapidly extending and the safety of the procedure has lead to an increasing interest among couples at high reproductive risk. Following PGD for aneuploidy, a higher implantation rate and a lower incidence of spontaneous abortions are obtained in patient categories where aneuploidy is a prominent cause of reproductive failure. In view of these findings, PGD has become an integral part of assisted reproductive techniques for the prevention of affected pregnancies and improvement of IVF efficiency.

Adult↗
PubMed2003

Birth of a healthy female after preimplantation genetic diagnosis for Charcot-Marie-Tooth type X.

The X-linked dominant form of Charcot-Marie-Tooth syndrome (CMTX) is a clinically and genetically heterogeneous hereditary disorder of the peripheral nerves caused by mutations in the GJB1 gene that encodes a gap junction protein named connexin 32 (Cx32). Clinically, CMTX is characterized by peripheral motor and sensory deficit with muscle atrophy. A couple with a previous history of pregnancy termination after being diagnosed positive for CMTX by chorionic villus sampling, was referred for preimplantation genetic diagnosis (PGD). The female partner carried the causative H94Q, characterized by a C-->G substitution in codon 94 of exon 2 of the GJB1 gene. Embryos obtained after intracytoplasmic sperm injection (ICSI) were evaluated for the presence of the mother's mutation using polymerase chain reaction (PCR), followed by mutation analysis performed using the minisequencing method. Amelogenin sequences on the X and Y chromosomes were also co-amplified to provide a correlation between embryo gender and mutation presence. A single PGD cycle was performed, involving nine fertilized oocytes, five of which developed into good quality embryos useful for biopsy. Two unaffected embryos were transferred, resulting in a singleton pregnancy followed by the birth of a healthy female.

Adult↗
PubMed2003

The minisequencing method: an alternative strategy for preimplantation genetic diagnosis of single gene disorders.

We have applied a new method of genetic analysis, called 'minisequencing', to preimplantation genetic diagnosis (PGD) of monogenic disorders from single cells. This method involves computer-assisted mutation analysis, which allows exact base identity determination and computer-assisted visualization of the specific mutation(s), and thus facilitates data interpretation and management. Sequencing of the entire PCR product is unnecessary, yet the same qualitative characteristics of sequence analysis are maintained. The main benefit of the minisequencing strategy is the use of a mutation analysis protocol based on a common procedure, irrespective of the mutations involved. To evaluate the reliability of this method for subsequent application to PGD, we analysed PCR products from 887 blastomeres including 55 PGD cases of different genetic diseases, such as cystic fibrosis, beta-thalassaemia, sickle cell anaemia, haemophilia A, retinoblastoma, and spinal muscular atrophy. Minisequencing was found to be a useful technique in PGD analysis, due to its elevated sensitivity, automation, and easy data interpretation. The method was also efficient, providing interpretable results in 96.5% (856/887) of the blastomeres tested. Fifteen clinical pregnancies resulted from these PGD cases; conventional prenatal diagnosis confirmed all the PGD results, and 10 healthy babies have already been born. Its applicability to PGD could be helpful, particularly in cases in which the mutation(s) involved are difficult to assess by restriction analysis or other commonly used methods.

Blastomeres↗
PubMed2002

Preferential location of sex chromosomes, their aneuploidy in human sperm, and their role in determining sex chromosome aneuploidy in embryos after ICSI.

BACKGROUND: In babies born after ICSI procedures, an increase of de-novo sex chromosome abnormalities has been observed. Several hypotheses have been proposed to explain these findings: an increased rate of sex chromosome aneuploidy in sperm of oligozoospermic men, or a preferential location of the sex chromosomes in the sub-acrosomal region of the sperm nucleus which leads to a reduced DNA decondensation of this region. In order to investigate which theory may be more reliable, we studied the localization of sex chromosomes and their aneuploidy rate in sperm in men undergoing ICSI. METHODS: Using fluorescent in-situ hybridization we studied sex chromosome localization and the aneuploidy rate for sex chromosomes and chromosome 18 in 20 oligospermic men undergoing ICSI and in 10 controls. RESULTS: In 40.94 and 52.92% of cases, the X and Y chromosomes respectively were localized in the sub-acrosomal region of the sperm nucleus compared with only 14.29% of cases of chromosome 18 (P < 0.001). An increase of sex chromosome aneuploidy in sperm of oligospermic men was observed; 2.91 versus 0.69% of controls (P < 0.001). CONCLUSIONS: Sex chromosomes are localized preferentially in the sub-acrosomal region of sperm and sex chromosome aneuploidy rate in the sperm of oligozoospermic men is higher than in controls.

Acrosome↗
PubMed2002

A new molecular and cytogenetic approach to sterility. A review of the literature.

In the therapeutic procedure of conjugal fertility, the use of intracytoplasmic sperm injection (ICSI) has opened new possibilities when conventional in vitro fertilization (IVF) techniques are unsuccessful. Cytogenetic studies showed the presence of genetic anomalies in foetuses conceived with this technique. Starting from these considerations, through a data collection of the literature, the authors report the latest scientific findings on this problem. They show the limits of the knowledge about genetic risks linked to these techniques, increasingly imposing rigorous medical behavior and conscious choices of the couple.

Cytogenetics↗
PubMed2001

Occurrence of thanatophoric dysplasia type I (R248C) and hypochondroplasia (N540K) mutations in two patients with achondroplasia phenotype.

We report two patients with clinical and radiological findings of achondroplasia, who had the most common FGFR3 mutation occurring in thanatophoric dysplasia type I and hypochondroplasia, respectively. Thanatophoric dysplasia is usually a lethal condition, but the patient carrying this mutation is alive and presents a medical history similar to that of patients with achondroplasia. The events leading to such a discrepancy between genotype and phenotype are unclear. These rare cases may influence an appropriate medical and genetic counseling.

Achondroplasia↗
PubMed2001

[Single-slice and multi-slice computerized tomography: dosimetric comparison with diagnostic reference dose levels].

PURPOSE: The absorbed dose during clinical examinations of the head, thorax, abdomen and pelvis performed with a single-slice CT scanner and a new multi-slice CT system was measured and compared. Technical parameters, defined at installation and memorized on the two CT machines relate to a standard-sized patient and were considered the reference standard. Our experimental data were also been compared with the Diagnostic Reference Levels (D.L. 26/5/2000 n.187, Annex V). MATERIAL AND METHODS: We compared the performance of a multi-slice GE LightSpeed QX/i ADVANTAGE to that of a single-slice GE ProSpeed SX. The radiation beam profiles were measured at isocenter using a phosphor plate. Dose measurements were performed, according to the EUR 16262 EN Guidelines, with a 10-cm long CT pencil ionisation chamber and two PMMA phantoms (CEI EN 61223-2-6) for head and body respectively. RESULTS: The obtained (normalised and weighted) computed tomographic dose index (nCTDIW) values were systematically higher for the multi-slice system (up to 36%) and the dose-length product (DLP) values on the multi-slice scanner exceeded the equivalent single-slice DLP values. The values were, however, always lower than DRLs, except in the case of the head multi-slice protocol, the technical parameters of which need to be improved. Our results allowed moreover to calibrate the automatic dose evaluation system of the multi-slice system, which systematically underestimated DLP values. DISCUSSION AND CONCLUSIONS: The comparison showed that the multi-slice scanner delivers a higher dose compared to the single-slice scanner. This is due to the radiation beam profile which is wider than the total active detector width, to the shorter focal spot-to-isocenter distance and to the effective scan length, which is longer than the nominal irradiated volume because the reconstruction algorithm of a multi-slice helical CT image requires the projection data from all detector rows. Nevertheless, the technology of new CT systems equipped with a multiple row detectors array can improve the protection of the patient thanks to very short irradiation time (less than 1 s) and reduced current values. In order to optimize the dose to the patient some acquisition parameters have been adjusted for head examinations.

Radiation Dosage↗
PubMed2000

Sonographic and molecular diagnosis of thanatophoric dysplasia type I at 18 weeks of gestation.

Thanatophoric dysplasia is the most common type of lethal skeletal dysplasia. It can usually be diagnosed with ultrasound, but differential diagnosis with other osteochondrodysplasias is not always possible. Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene have been demonstrated to cause two distinct subtypes of the disorder. We describe a case of thanatophoric dysplasia type I diagnosed at 18 weeks of gestation by ultrasonography. Genomic DNA obtained by chorionic villus sampling showed a C to G substitution at position 746 in the FGFR3 gene, resulting in a Ser249Cys substitution already known to be associated with type I disease. Implications for perinatal management are discussed.

Adult↗
PubMed2000

Tailoring interferon dose and monitoring viral load in hepatitis C virus genotype 1b infected patients: a pilot study.

BACKGROUND AND AIMS: Complete [biochemical and virological) primary response remains the first goal of any antiviral therapy and its early assessment could be particularly useful in the management of the high viral load, genotype 1b infected patients, who have the worst chance of response. We evaluated whether tailoring interferon dose according to pre-treatment viral load and early monitoring of quantitative HCV-RNA could either improve or predict the results of recombinant alpha-2a interferon treatment in these patients. PATIENTS: Fifty-three consecutive genotype 1b HCV-infected patients, stratified in two groups by viral load (cut off 6 MEq/ml), received randomly 6 or 9 MU of recombinant alpha-2a interferon thrice weekly for 6 months, followed by 6 MU for another 6 months. METHODS: HCV-RNA was measured [b-DNA] assay) two months apart prior to therapy, at baseline, after 2 weeks of therapy and monthly thereafter. RESULTS: In the high viraemic group, complete primary response was observed in 80% of patients treated with high dose recombinant alpha 2a interferon and only in 14.3% of low dose treated patients [p<0.03]. In low viraemic patients, complete primary response was 53. 8% in low dose patients and 80% (8 out of 10) in the high dose group. Sustained response was 60% in high viraemic patients treated with high dose and absent in those treated with low dose [p<0.05]. One log viral load decrease at 2 or 4 weeks showed 0.87 and 0.80 positive predictive values, 0.95 and 1.0 negative predictive values with 96% and 100% sensitivities and 83% and 70% specificities. CONCLUSIONS: 6 MU recombinant alpha-2a interferon thrice weekly schedules were completely ineffective in the large majority (85.7%) of patients with viral load above 6 million HCV-RNA copies/ml and the treatment failure could be predicted by lack of one log viral load decrease after 2-4 weeks of treatment.

Adult↗