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Biomedical subjects

G Calabrese

Publications and source records attributed to G Calabrese.

At least 55 records · Page 3Linked to original sources
PubMed1998

Prostanoid production in endothelial and Kupffer liver cells from monocrotaline intoxicated rats.

UNLABELLED: A single dose of monocrotaline, a pyrrolizidine alkaloid, was injected into rats in order to produce 25 (Group I) and 45 (Group II) days later a progressive and so called delayed liver injury. The present study investigated the prostanoid production of Kupffer cells and endothelial cells separated from Monocrotaline and saline (Group III) injected rat livers. Kupffer cells: formation of 6 keto Prostaglandin F1 alpha, the major prostacycline metabolite, gradually decreased in Groups I vs II (P < 0.01) and in both Groups I and II vs Controls (P < 0.01). In addition Prostaglandin F2 alpha showed a significant increase in Groups I and II when compared to Group III, (P < 0.001), and Thromboxane B2 was present in both Groups of Monocrotaline treated animals, while it was not detectable in the control Group III. Endothelial cells: 6 keto Prostaglandin F1 alpha decreased in Groups 1 vs II. This differences was significant when compared, and compared to controls (Group III, P < 0.001). Prostaglandin E2 was detected only in Groups I and II. Prostaglandin F2 alpha and Thromboxane B2 could not be detected in any Group. Ultramicroscopy showed morphological cell damage in nonparenchymal cells in Monocrotaline intoxication in Group II, rats sacrificed 45 days after the injection, while it shows normal features in those treated animals sacrificed 25 days after the injection, as well as in control group. CONCLUSION: A single Monocrotaline injection produces, 25 and 45 days later, severe and progressive alterations in the prostanoid production in Kupffer and Endothelial cells, while ultramicroscopic alterations was only observed 45 days after the injection of Monocrotaline. A decreased production of vasodilators and the presence of vasoconstrictor prostanoids that can participate in the production of the circulatory derangements enhancing liver injury and portal hypertension were also observed.

Animals↗
PubMed1998

Benign versus secondary-progressive multiple sclerosis: the potential role of proton MR spectroscopy in defining the nature of disability.

PURPOSE: We determined the clinical utility of proton MR spectroscopy in defining the extent of disability in benign versus secondary-progressive multiple sclerosis (MS). METHODS: Thirty patients with clinically definite MS, including 16 patients with benign MS and 14 with secondary-progressive MS, and a group of 13 healthy volunteers were studied with combined stimulated-echo acquisition mode proton MR spectroscopy and MR imaging (all patients received contrast material). RESULTS: Acute enhancing lesions of benign and secondary-progressive MS were characterized by a reduction in N-acetylaspartate (NAA)/choline and NAA/creatine and an increase in inositol compounds/creatine as compared with normal white matter. Such variations were also detected in chronic unenhancing lesions in patients with secondary-progressive MS, although they were not found in chronic unenhancing lesions in patients with benign MS. Chronic lesions of the two forms of the disease have significative differences in NAA and inositol signals. CONCLUSION: Proton MR spectroscopy is able to show metabolic changes occurring in the white matter of patients with MS. Such changes differ according to the phase (acute versus chronic) and the clinical form (benign versus secondary-progressive) of the disease.

Adult↗
PubMed1998

Progressive brain failure after diffuse hypoxic ischemic brain injury: a serial MR and proton MR spectroscopic study.

The findings at sequential MR imaging and proton MR spectroscopy of a patient with profound hypoxic-ischemic brain injury are reported. The pattern of structural and biochemical changes observed closely reflected the known evolution of postasphyxic brain degeneration. Particularly noteworthy were the sharp decrease of cortical N-acetylaspartate in the acute phase, suggesting the severity of the neuronal insult, and the subsequent progressive increase of choline, paralleling the delayed degeneration of white matter.

Adult↗
PubMed1998

[Magnesium hydroxide in idiopathic calcium nephrolithiasis].

BACKGROUND: While in vitro the protective effect of magnesium on calcium oxalate crystallization is well known, its clinical relevance in calcium nephrolithiasis is still debated. Therefore, the clinical and metabolic effects of magnesium hydroxide therapy were evaluated in calcium stone formers. METHODS: Nine patients (7 M, 2 F), selected for a low urinary magnesium excretion (uMg 56 +/- 12 mg/day), were given Mg hydroxide (500 mg/day), with clinical and metabolic controls at 3, 12 and 18 months. RESULTS: Urinary Mg/uCreat increased throughout the study; uOx/uCreat decreased significantly; uCa/uCreat increased but not significantly. The stone recurrence rate decreased from 0.75 to 0.11 stones/year/patient, throughout the study period. The decrease of uOx is considered a more important risk factor in calcium stone patients than a similar uCa change; it may be due to a reduced intestinal Ox absorption, for the formation of insoluble and not absorbed Mg oxalate. CONCLUSION: In conclusion, Mg hydroxide therapy was encouraging in patients with calcium nephrolithiasis and low uMg; nevertheless a longer period of treatment is needed to confirm these data.

Calcium↗
PubMed1998

Platelet endothelial cell adhesion molecule-1 expression during mouse postimplantation development.

With the aim to analyze the ontogeny of the mouse endothelium, monoclonal antibody (mAb) MEC 13.3 was used for the immunohistochemical staining of frozen sections of different stages of mouse embryo development. This mAb specifically recognizes membrane reinforcement of endothelial cells (EC) from mouse blood vessels, indicating the expression of a molecule related to the murine form of PECAM-1/CD31. The present study reports the expression of the murine PECAM-1/CD31 antigen, observed with the peroxidase-antiperoxidase technique, in a single cell type, with a typical non-differentiated morphology at an early stage of mouse postimplantation embryos. A progressive increase in the number of this cell type was observed in the early stages of murine development, but few were detected at mature stages. On the other hand, EC in days 9.5, 14.5 and 19.5 postcoitum embryos were also recognized by the same mAb MEC 13.3 allowing the recognition of a cell type related directly or indirectly to vascular network development.

Animals↗
PubMed1998

Prenatal diagnosis using the triple test.

METHODS: A screening study performed on 2,803 pregnant women using the "triple test" is reported. RESULTS: Nine hundred and twenty-one had a high prior risk, having > 35 years while, after the screening, only 201 women had a positive test at risk higher than 1:270, and underwent to amniocentesis. The detection rate (DR) for all abnormalities was 91% while for Down's syndrome (DS) it was 87.5% and for neural tube defects 85.5%. Foetal abnormalities were detected in 20 cases (1:10) while 181 were false positive cases (6.5%), of which 151 for DS (5.4%). False negative were observed only in 2 cases within 2,339 at term pregnancies. CONCLUSIONS: The authors retain that high DR is related to the exactness of determination of gestation age calculated by scan and to the homogeneity of the examined population.

Adult↗
PubMed1997

p53 loss and point mutations are associated with suppression of apoptosis and progression of CML into myeloid blastic crisis.

A longitudinal investigation using fluorescence in situ hybridization (FISH) analysis, PCR-SSCP, and in situ detection of apoptosis by the terminal deoxynucleotidyl Transferase (TdT) method was carried out on 13 chronic myelogenous leukemia (CML) patients to study the p53 gene behavior and the apoptotic process during the course of the disease. At diagnosis, FISH showed no loss of the p53 gene on interphase nuclei, and no point mutation was detected by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) and sequencing. During the disease course, FISH analysis showed a significative loss of allele (LOA) rate for the p53 gene in eight patients that in seven cases was associated with a suppression of apoptotic process and the progressive expansion of the p53+/p53- clone. DNA sequencing showed in two of these eight patients a point mutation on the other allele, consisting in the formation of a stop codon in one case, and in a frameshift mutation in the other. Six patients had a myeloid blastic crisis (BC), five a lymphoid BC, and the other two an erythroid and an undifferentiated BC, respectively. All patients with myeloid BC and the one with undifferentiated BC disclosed a progressive expansion of the clone with p53 loss that was associated with a significant reduction in apoptosis. On the contrary in the 5 patients with lymphoid BC no significant p53 LOA rate was observed during the course of the disease. In these patients apoptotic process also persisted in the acute phase although in a lower rate as compared to CP.

Adolescent↗
PubMed1997

UFD1L, a developmentally expressed ubiquitination gene, is deleted in CATCH 22 syndrome.

The CATCH 22 acronym outlines the main clinical features of 22q11.2 deletions (cardiac defects, abnormal facies, thymic hypoplasia, cleft palate and hypocalcemia), usually found in DiGeorge (DGS) and velo-cardio-facial (VCFS) syndromes. Hemizygosity of this region may also be the cause of over 100 different clinical signs. The CATCH 22 locus maps within a 1.5 Mb region, which encompasses several genes. However, no single defect in 22q11.2 hemizygous patients can be ascribed to any gene so far isolated from the critical region of deletion. We have identified a gene in the CATCH 22 critical region, whose functional features and tissue-specific expression suggest a distinct role in embryogenesis. This gene, UFD1L, encodes the human homolog of the yeast ubiquitin fusion degradation 1 protein (UFD1p), involved in the degradation of ubiquitin fusion proteins. Cloning and characterization of the murine homolog (Ufd1l) showed it to be expressed during embryogenesis in the eyes and in the linear ear primordia. These data suggest that the proteolytic pathway that recognizes ubiquitin fusion proteins for degradation is conserved in vertebrates and that the UFD1L gene hemizygosity is the cause of some of the CATCH 22-associated developmental defects.

Adaptor Proteins, Vesicular Transport↗
PubMed1997

Clustering of Y chromosome deletions in subinterval E of interval 6 supports the existence of an oligozoospermia critical region outside the DAZ gene.

Y chromosome molecular analysis was performed using the STS-PCR technique in 50 patients with oligozoospermia. Microdeletions of interval 6 of the Y chromosome were detected in seven patients, in six of whom subinterval E was affected. All patients retained the RBM1 and DAZ genes, while in one deletion involved the SPGY gene. The size of the deletion was not apparently related to the severity of the disease. These results suggest the presence of an oligozoospermia critical region on the Y chromosome within subinterval E of interval 6.

Adult↗
PubMed1997

Two newborns with chromosome 4 imbalances: deletion 4q33-->q35 and ring r(4)(pterq35.2-qter).

Two patients are reported who presented with 4q deletion and r(4), respectively. Cytogenetic and FISH analysis defined the breakpoints respectively at bands 4q33-->q35 proximal to the telomere, and 4pter and 4q35.2 qter. Moreover in both cases rearranged chromosomes maintained telomeric sequences. The first patient showed some clinical features of deletion 4q and a pointed 5th finger, a characteristic finding in deletion 4q31-->qter. The second patient had mild dysmorphism associated with growth retardation.

Chromosome Deletion↗
PubMed1996

Complex chromosome translocations of standard t(8;21) and t(15;17) arise from a two-step mechanism as evidenced by fluorescence in situ hybridization analysis.

The authors report the results of cytogenetic and fluorescence in situ hybridization (FISH) analysis performed on complex chromosome translocations (CCTs) of t(8;21) and t(15;17) standard translocations associated with two M2 subtypes of acute myeloid leukemia (AML-M2) and four acute promyelocytic leukemia (APL), respectively. In one of two AML-M2 patients FISH analysis showed part of chromosome 21 on the der(8) and material from this chromosome on the der(21) and on chromosome 1 at band p32, suggesting that the t(8;21) occurred as the primary step. In the second AML-M2 patient. FISH displayed part of chromosome 21 on the der(8) and material from this chromosome on the der(21) but not on the third rearranged chromosome. Therefore, it is unclear whether chromosome 2 was rearranged secondary to the standard t(8;21). In four APL patients, FISH analysis showed material derived from chromosome 17 on the der(15). Moreover, in two patients with an i(17q) FISH disclosed material from chromosome 15 at the ends of both arms of the i(17q), suggesting that it occurred after the standard t(15;17). In the remaining two APL patients, FISH showed material from chromosome 15 on the der(17) and on chromosome 21 at band q22 in one case, and material of the p arm of chromosome 17 on chromosome 4 at band q11 in the other, demonstrating that in these two cases the first mutation also had been the t(15;17). Therefore, FISH analysis revealed that CCTs in five patients were secondary changes which occurred after standard t(8;21) and t(15;17), thus clarifying the hierarchy of the cytogenetic events, their role in the pathogenesis of the disease, and the associated clinic-hematologic findings.

Adult↗
PubMed1996

Otoneurological study in workers exposed to styrene in the fiberglass industry.

Twenty workers exposed to styrene and acetone in small fiberglass factories were monitored for 8 h using passive dosimeters. Urine samples were collected at the end of the workshift and before the start of work on the next morning. The 8-h time-weighted average exposure values for styrene and acetone ranged from 14 to 416 mg/m3 and from 70 to 277 mg/m3, respectively. The sum of styrene metabolites, mandelic acid and phenylglyoxylic acid (MA + PGA), in the next-morning urine samples ranged from 81 to 943 mg/g creatinine. Different test sensitivity was identified in the otoneurological battery: it was low for audiometric tests and ABR, and relatively high for vestibular tests. The vestibular system seems partially sensitive to the toxic effects of styrene in the absence of clinical signs and symptoms. The actual exposure levels for styrene cannot be considered devoid of functional subclinical consequences.

Acetone↗
PubMed1996

Proton magnetic resonance spectroscopy and intracranial tumours: clinical perspectives.

Proton magnetic resonance spectroscopy (1H-MRS) was applied to characterize intracranial tumours of different hystological types. Seventy patients with intracranial neoplasms were studied before receiving surgery, radiotherapy or chemotherapy. All tumours were characterized by reduced or absent N-acetylasparate and increased signal from choline-containing compounds. Distinctive patterns were observed only for primitive brain neoplasms; high-grade gliomas were differentiated from low-grade ones by higher levels of choline-containing compounds. The metabolic aspects of metastatic lesions were similar to high-grade gliomas. These results, together with the limitations of 1H-MRS and future applications are reviewed.

Adenoma↗
PubMed1996

Non-invasive early prenatal molecular diagnosis using retrieved transcervical trophoblast cells.

Fetal DNA was recovered from 17 of 39 (44%) transcervical cell (TCC) samples obtained between 7 and 9 weeks of gestation by endocervical canal flushing. Trophoblast retrieval was adequate for polymerase chain reaction (PCR) amplification of Y chromosome-specific DNA sequences and detection of paternal-specific microsatellite alleles. The fetal sex predicted by PCR in TCCs was confirmed in all cases by karyotype analysis of chorionic villi at 10 weeks of gestation. The absence of the disease-associated paternal alleles in TCC samples from two pregnancies at risk for spinal muscular atrophy and myotonic dystrophy predicted unaffected fetuses in agreement with subsequent results on chorionic villi and newborns' leukocytes. A trisomy 21 fetus was diagnosed in TCCs using fluorescent in situ hybridization (FISH) and semi-quantitative PCR analysis of superoxide dismutase-1 (SOD 1). Present experience indicates that TCC sampling is a promising technique for early prenatal monitoring of Mendelian disorders and chromosome aneuploidy.

Adult↗
PubMed1996

Diagnosis of DiGeorge syndrome in nuclei released from archival autoptic heart specimens using fluorescence in situ hybridization.

Seven formalin-fixed, paraffin-embedded heart specimens set up at autopsy performed from 3 to 18 years before analysis of newborns in which DiGeorge syndrome (DGS) was suspected were evaluated by fluorescence in situ hybridization (FISH) using a DGS region-specific probe and a control probe on nuclei released from thick sections. The diagnosis was confirmed in four of the six specimens, which provided valuable results, and in none of the controls. This study supports the feasibility and usefulness of FISH genotyping of archival autoptic material, which improves and assists the counselling procedures.

Autopsy↗
PubMed1996

Molecular studies in three patients with isodicentric Y chromosome.

Three patients carrying an isodicentric (idic) Y chromosome associated with a mosaic 45,X cell line were studied using molecular techniques. Genotype-phenotype correlations suggested an effect of the 45,X cell line on sexual differentiation. A relationship was established between instability of the idic(Y) chromosome and localization of the breakpoint on Yq, and between azoospermia and deletion of interval 6 on Yq.

Adult↗