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Biomedical subjects

G Calabrese

Publications and source records attributed to G Calabrese.

At least 37 records · Page 2Linked to original sources
PubMed2000

Audiogenic seizures susceptibility in transgenic mice with fragile X syndrome.

PURPOSE: To evaluate their susceptibility to audiogenic seizures, five groups of knockout mice with various forms of fragile X genetic involvement [hemizygous males (n = 46), and homozygous (n = 38) and heterozygous females (n = 45), and their normal male (n = 45) and female (n = 52) littermates] were studied. METHODS: All mouse groups were tested at ages 17, 22, 35, and 45 days. Audiogenic seizure susceptibility was scored, and the analysis of variance was used for the evaluation of the effects of age and genetic condition on seizure severity score (SSS). RESULTS: All groups of knockout fragile X mice exhibited SSSs significantly higher than those observed in their wild-type littermates; among knockout mice, hemizygous males and homozygous females showed the highest SSSs. Hemizygous males showed higher SSSs with increasing age, from 17 to 45 days; homozygous females showed a peak at age 22 days, followed by a decrease; finally, heterozygous females had their highest SSSs at age 17 days. CONCLUSIONS: This study demonstrates that an increased susceptibility to audiogenic seizures is present in fragile X knockout mice at all the ages tested. These results support the validity of this animal model also for epilepsy and seizures in the human fragile X syndrome.

Acoustic Stimulation↗
PubMed2000

Characterization of a new TSPY gene family member in Yq (TSPYq1).

We investigated subinterval 6E on the human Y chromosome, a region frequently deleted in infertile males. YAC yOX17, mapped within subinterval 6E by STS-PCR, was analyzed for the presence of new genes. TSPYq1, a member of the TSPY multi-copy gene family, was isolated and characterized from a yOX17 cosmid subclone. PCR and FISH analysis performed on normal subjects and on patients with microdeletions of Yq suggested the presence of multiple copies of TSPY in Yq.

Amino Acid Substitution↗
PubMed2000

[Radiologic diagnosis of spondylodiscitis: role of magnetic resonance].

PURPOSE: To report the Magnetic Resonance Imaging (MRI) features of acute and chronic spontaneous spondylodiscitis as well as any typical patterns which can be useful for the differential diagnosis between pyogenic and tuberculous forms. MATERIAL AND METHODS: Eleven patients affected with spontaneous spondylodiscitis were selected for the study; they were 7 men and 4 women ranging in age 33-87 years (mean: 64). We excluded the patients with iatrogenic spondylodiscitis. MR images were acquired with a superconductive magnet at 1.5, with the following sequences: sagittal PD and T2-weighted TSE, sagittal T1-weighted SE, axial PD and T2-weighted TSE for the lumbar spine, axial T2-weighted GRE for the cervical and dorsal spine and axial and sagittal T1-weighted SE after contrast agent (gadolinium DTPA) injection. MR images were reviewed by three experienced radiologists and morphological and signal intensity changes of vertebral body and disk were recorded on a standard form. In 9 patients it was possible to compare MR to CT findings. RESULTS: At the time of our observation all patients reported pain at the spine level, associated with fever and weight loss in 50% of cases and with increased values of the inflammatory markers. Three patients had infectious diseases in other organs and 2 were diabetics. Biopsy was performed in two cases only and demonstrated Staphylococcus aureus in one and Mycobacterium tuberculosis in the other patient. MRI allowed the correct diagnosis to be made in all cases, demonstrating the pathological involvement of the paravertebral structures and into the spinal canal earlier and more accurately than CT. A common finding in pyogenic and tuberculous spondylodiscitis was the low signal of the subcortical bone marrow on T1-weighted sagittal images, which enhanced after Gd-DTPA administration and became intermediate or high on T2-weighted images. Moreover, the steady high signal intensity of the disk on T2-weighted images and its contrast enhancement on T1-weighted images is typical for an acute inflammatory process. CONCLUSIONS: Based on our personal experience and literature data, we believe MRI to be the most sensitive technique for the diagnosis of spondylodiscitis in the acute phase, whereas it is comparable to CT in the chronic stage of the disease. At present MRI does not allow to differentiate pyogenic from tuberculous forms.

Acute Disease↗
PubMed2000

[Plasma levels of homocysteine in patients on hemodiafiltration].

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases, and is a common finding in patients on regular dialysis treatment. Hemodialysis lowers homocysteine plasma levels in variable amounts, and it was also suggested that folic acid and vitamin B12 supplements can reduce such levels. The purpose of the present study was to evaluate homocysteine plasma levels in patients on hemodiafiltration who received vit. B12 and folate supplements such as to keep their plasma levels in the normal range. METHODS: A retrospective study was carried out in a group of 36 patients on hemodiafiltration, who received routinely folate and vit. B12 supplements i.v. Pre-dialysis plasma levels of folate and vit. B12 and pre-postdialysis homocysteine concentration were evaluated. The latter was correlated with other parameters. RESULTS: The present study confirmed high homocysteine levels in patients on RDT and their reduction due to dialysis, demonstrated a weak negative correlation of pre-dialysis homocysteine with vit. B12 plasma level, but no correlation with folic acid. CONCLUSIONS: This study showed a good efficiency of hemodiafiltration using high permeability membranes on homocysteine removal, whereas the negative correlation between folate and homocysteine plasma level was not confirmed.

Aged↗
PubMed1999

Zinc sulfate supplementation improves thyroid function in hypozincemic Down children.

In subjects affected by trisomy 21 (Down syndrome), hypothyroidism is the most common endocrinological deficit. Plasma zinc levels, which are commonly detected below the normal range in Down patients, are related to some endocrinological and immunological functions; in fact, zinc deficiency has been shown to impair immune response and growth rate. Aims of this study were to evaluate (1) the role of zinc deficiency in subclinical hypothyroidism and (2) thyroid function changes in Down children cyclically supplemented with zinc sulfate. Inverse correlations have been observed between age and triiodotironine (T3) and between zinc and thyroid-stimulating hormone (TSH); higher TSH levels have been found in hypozincemic patients at the beginning of the study. After 6 mo of supplementation, an improvement of thyroid function (TSH levels: 3.96 +/- 1.84 vs 2.64 +/- 1.33 mUI/mL basally and after 6 mo, respectively) was observed in hypozincemic patients. In the second cycle of supplementation, a similar trend of TSH was observed. At the end of the study, TSH significantly decreased in treated hypozincemic subjects (4.48 +/- 1.93 vs 2.96 +/- 1.20 mUI/mL) and it was no longer different in comparison to normozincemic patients. We suggest zinc supplementation to the diet in hypozincemic Down children as a simple and useful therapeutic tool.

Adolescent↗
PubMed1999

X/Y translocation in a family with Leri-Weill dyschondrosteosis.

An X/Y translocation associated with Leri-Weill dyschondrosteosis (LWD) was detected in a boy and in his mother. FISH analysis with specific probes for SHOX and SRY displayed no signal on the der(X), while one signal for SHOX was detected on the normal X chromosome in the mother, and one signal each for SHOX and SRY was detected on the normal Y chromosome in the proband.

Adult↗
PubMed1999

Nonalcoholic compounds of wine: the phytoestrogen resveratrol and moderate red wine consumption during menopause.

The literature on the natural sources of resveratrol, a phytochemical substance found in grapes and wine, is reviewed herein. Its structure is similar to that of diethylstilbestrol and, like other authors, we consider that resveratrol might be a phytoestrogen. We analyzed the populations who ingest this substance, as well as the known biological effects of phytoestrogens in humans. The literature on the effects of resveratrol on female reproduction, osteoporosis and cancer was assessed using relevant case reports and cohort studies, as well as randomized trials and review articles. We conclude that phytoestrogens exhibit physiological effects in humans and that these estrogenic actions increase the biological reactions produced by moderate red wine consumption with meals.

Clinical Trials as Topic↗
PubMed1999

Loss of the SHOX gene associated with Leri-Weill dyschondrosteosis in a 45,X male.

A male patient is reported with a 45,X karyotype and Leri-Weill dyschondrosteosis (LWD). FISH analysis with SHOX and SRY gene probes was carried out. One copy of both SHOX and SRY was detected in interphase nuclei, clarifying the origin of LWD and the male phenotype. Molecular results suggested that the 45,X karyotype arose through two independent events. The first occurred at paternal meiosis leading to an unequal crossing over between the short arms of the X and Y chromosomes. As a consequence, the SRY gene was translocated onto Xp, thereby explaining the male phenotype of the patient. The second event probably occurred at maternal meiosis or at the early stages of the zygote resulting in the loss of the maternal X chromosome.

Adolescent↗
PubMed1998

A quarter of men with idiopathic oligo-azoospermia display chromosomal abnormalities and microdeletions of different types in interval 6 of Yq11.

Cytogenetic investigations and molecular analysis of the Y chromosome by the polymerase chain reaction amplification of sequence-tagged sites (STS-PCR) technique were performed in 126 patients affected by idiopathic oligo-azoospermia following accurate selection of cases. Seventeen patients evidenced an abnormal karyotype. Fourteen patients with a normal karyotype had microdeletions of the Y chromosome within interval 6. In azoospermic patients microdeletions were scattered along different subintervals, while in oligozoospermic patients they were clustered in subinterval 6E. The size of the deletion was not apparently related to the severity of the disease. These results suggest that cytogenetic analysis and the STS-PCR technique can detect a genetic cause of infertility in about one-quarter of patients with idiopathic oligo-azoospermia.

Adult↗
PubMed1998

Correlation between apoptosis and TP53 status in osteosarcoma.

Samples of 18 osteosarcomas were examined for the occurrence of apoptosis and TP53 status. Apoptosis was investigated by an in situ nick translation technique on paraffin-embedded samples. It was found that apoptosis rarely occurs in osteosarcoma at the early stage of disease, whereas it is frequently activated when tumors are treated with antiblastic drugs. The analysis of the TP53 gene showed no mutation at diagnosis; whereas, during disease progression, four cases showed TP53 mutations. The authors discuss the relation between apoptosis, TP53 status, and therapy.

Adolescent↗
PubMed1998

Hepatitis C virus heteroduplex tracking assay for genotype determination reveals diverging genotype 2 isolates in Italian hemodialysis patients.

A heteroduplex tracking assay (HTA) was developed for genetic analyses of the hepatitis C virus (HCV) using single-stranded probes from the core (C)/E1 region. Nucleotide sequencing of reverse transcriptase (RT)-PCR products from 15 Italian dialysis patients confirmed the specificity and accuracy of the HTA genotyping method, which identified 5 of 15 (33.3%) 1b, 7 of 15 (46.7%) 3a, and 3 of 15 (20%) type 2 infections. The genotypes of an additional 12 HCV antibody-positive blood donors from different geographical locations were also in agreement with the genotypes determined by the Inno-LiPA HCV II kit (Innogenetics) and/or restriction fragment length polymorphism (RFLP). Isolates which had between 35 to 40% nucleotide divergence from control subtype 1a, 1b, 2a, 2b, or 3a standards could be typed. Surprisingly, HTA detected one 1b-2 coinfection which was missed by DNA sequencing. Three samples that were designated non-2a or 2b type 2 by HTA were found to be type 2a by both RFLP and direct nucleotide sequencing of the 5' untranslated region. The genetic distance between patient type 2 and control 2a, 2b, and 2c isolates indicated that a new subtype was present in the population being studied. Serotyping (RIBA serotyping strip immunoblot assay kit) of 23 dialysis patients showed that the genotype could be determined in 6 of 8 (75%) C/E1 RT-PCR-negative and 15 of 23 (65.2%) RT-PCR-positive samples, indicating that the two tests complement each other.

Blood Donors↗
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↗