Search PubMed⌕ Search

Biomedical subjects

F Giannelli

Publications and source records attributed to F Giannelli.

At least 37 records · Page 2Linked to original sources
PubMed1997

Characterization of the gene (VBP1) and transcript for the von Hippel-Lindau binding protein and isolation of the highly conserved murine homologue.

A single-copy, widely expressed gene of at least 30 kb and six exons was discovered via a hybrid mRNA resulting from an inversion causing hemophilia A. A segment of the 1.7-kb message of this gene has been shown by others to encode a protein (named VBP1) interacting with the product of the von Hippel-Lindau gene and thus is expected to participate in pathways involving this tumor suppressor gene. The mouse VBP1 message we isolated encodes a polypeptide of 160 residues absolutely identical to that of human. Even the 3' untranslated tails of the mRNAs show 68% conservation, and both use the unusual ATTAAA polyadenylation signal. The mouse gene has a single transcription start while the human homologue has two major starts and a minor start. This could result in amino-end extensions of the human protein. A polymorphism with 42% heterozygosity in the United Kingdom population was detected in the 3' tail of the message. VBP1 is unlike other known proteins but a consensus for tyrosine phosphorylation possibly suggests regulation by kinases.

Animals↗
PubMed1997

Haemophilia B: database of point mutations and short additions and deletions, 7th edition.

The seventh edition of the haemophilia B database lists in easily accessible form all known factor IX mutations due to small changes (base substitutions and short additions and/or deletions of <30 bp) identified in haemophilia B patients. The 1535 patient entries are ordered by the nucleotide number of their mutation. Where known, details are given on: factor IX activity, factor IX antigen in circulation, presence of inhibitor and origin of mutation. References to published mutations are given and the laboratories generating the data are indicated.

Databases, Factual↗
PubMed1997

Impaired response to alpha interferon in patients with an inapparent hepatitis B and hepatitis C virus coinfection.

The possibility of hepatitis B virus (HBV) infection in HBsAg-negative patients has been shown. However, an "inapparent" coinfection by HBV in hepatitis C virus (HCV)-positive patients generally is not taken into account in clinical practice. Mechanisms responsible for resistance to interferon (IFN) have not been completely clarified. The aim of this study was to investigate whether an "inapparent" coinfection by HBV in anti-HCV-positive chronic liver disease patients may influence IFN response. Fourteen anti-HCV positive, HBsAg-negative but serum HBV DNA-positive patients by PCR and 111 anti-HCV-positive, HBsAg-negative and HBV DNA (PCR)-negative patients with chronic hepatitis were treated with 3 MU of recombinant alpha-2a IFN 3 times weekly for 12 months. Serum HBV DNA and HCV RNA were determined before treatment, after 6-12 months and in coincidence with ALT flare-up by PCR. HBV PCR was performed using primers specific for the S region of the HBV genome and HCV PCR with primers localised in the 5'NC region of HCV genome. IgM anti-HBc was tested using IMx Core-M Abbott assay. By the end of treatment, ALT values had become normal in 4/14 HBV DNA-positive patients (28%), but all "responders" (4/4) relapsed between 2 and 5 months after therapy. All but one patient were HCV RNA-positive before treatment, 6 were also both HBV DNA and HCV RNA-positive during ALT flare-ups. In 5 patients, only HBV DNA and in 3 patients, only HCV RNA was detected when transaminase values increased. All patients remained HBsAg-negative and anti-HCV-positive. IgM anti-HBc was detected both before treatment and during ALT elevation in 3 patients and only during ALT relapse in 3 others. Of the 111 anti-HCV positive, HBsAg-negative and HBV DNA (PCR)-negative patients with chronic hepatitis, a biochemical response to IFN treatment was observed in 54% of the cases. Relapse of ALT values was observed in 47% of the cases during a follow-up of 1 year after treatment. "Inapparent" HBV/HCV coinfection may be implicated in cases of resistance to IFN treatment. In addition, HBV replication may persist in patients in whom HCV replication was inhibited by IFN treatment. The pathogenic role of HBV in liver disease was confirmed by detection of IgM anti-HBc in some cases; the appearance of these antibodies only after IFN treatment suggests that IFN may exert a selective role in favour of HBV. Further studies will show the effect of different treatment schedules. HBV DNA and/or IgM anti-HBc detection with very sensitive methods may be important both as a prognostic factor and as a tool for better understanding interviral relationships and mechanisms involved in multiple hepatitis virus infections.

Adult↗
PubMed1997

Serum HCV-RNA and liver histologic findings in patients with long-term normal transaminases.

In this study we aimed to correlate liver histology and the presence of hepatitis C virus (HCV) viremia, genotype, and quantity of HCV genome in 19 positive and 11 RIBA II indeterminate patients presenting persistently normal ALT values over 24 months before biopsy. In addition, after biopsy serum ALT values were monitored monthly for a mean follow-up period of 24.8 months, after which patients were reevaluated for RIBA II and the presence of viremia. Sixteen patients (53%) were serum HCV-RNA-positive; 13 of them (68%) were confirmed positive and 3 (27%) indeterminate on RIBA II. Histology of the HCV-RNA-positive patients showed eight cases of CPH (one case of genotype 1a; four cases type 1b; three cases type 2), six cases of CAH (three cases type 1b, three cases type 2), one case of CLH (type not determined), and one case of normal liver (NL) (type 1b). Histology of the HCV-RNA-negative patients showed four cases of CPH, one case of CAH, two cases of CLH, and seven cases of NL. During the follow-up period nine patients (30%) presented slight increases in ALT values (< 2 x N), and in particular, flares of ALT were observed four times in the CAH and five times in the CPH patients, who were all viremic, but never in the NL subjects. These results indicate that subjects positive on RIBA II, but with persistently normal ALT values, had a high probability of being serum HCV-RNA-positive and that almost all these viremic subjects presented histologic signs of liver disease. In contrast, RIBA II indeterminate subjects had a moderate probability of being HCV-RNA-positive, but a number of these may present signs of liver disease. In both cases there was no association with genotype or HCV-RNA serum levels. The other nonviremic cases included subjects with hepatic changes going toward resolution or with normal liver in whom hepatic biopsy can be avoided. Only one case was a true carrier since he was viremic with normal liver and persistently normal ALT values.

Adult↗
PubMed1997

Further evidence for the importance of an androgen response element in the factor IX promoter.

Previous work involving the characterizing of a factor IX promoter mutation (-26 G-->C) of a 21-year-old patient with severe haemophilia B suggested that an androgen response element (ARE) was present in the wild-type factor IX promoter but was disrupted in this patient. However, other theories not involving this ARE have been suggested for the mechanism of recovery in the more typical (Leyden) promoter patients, so that the ARE hypothesis requires further evidence if it is to be accepted. We now present a case history and functional data on another 48-year-old severe haemophilia B patient (UK232) with a different (G-->A) mutation at the same position, -26. This mutation impairs transactivation of the minimal factor IX promoter region (-220-->+43) by HNF4 in transient transfection experiments in HepG2 and HeLa cells. It disrupts binding of both androgen receptor (AR) and HNF4 to oligonucleotides spanning this region (-40-->-9) in competition gel mobility shift assays. It impairs AR/testosterone transactivation of these oligonucleotides (-40-->-9) when tetramerized upstream of a CAT reporter gene in cotransfection assays in HeLa cells. And, finally, no clinical recovery has occurred since puberty. These results strengthen the evidence for the importance of nucleotide -26, both for the normal transcription of the gene in response to HNF4 and for the proposed Leyden recovery mechanism in response to AR and testosterone acting directly through the factor IX ARE.

Adult↗
PubMed1997

Relevance of inapparent coinfection by hepatitis B virus in alpha interferon-treated patients with hepatitis C virus chronic hepatitis.

The aim of the study was to investigate whether an "inapparent" coinfection by hepatitis B virus (HBV) in anti-HCV-positive chronic liver disease patients may influence interferon (IFN) response. Fourteen anti-HCV-positive, hepatitis B surface antigen (HBsAg)-negative but serum HBV-DNA-positive patients and 111 anti-HCV-positive, HBsAg-negative, and HBV-DNA-negative patients with chronic hepatitis were treated with 3 MU of recombinant alpha-2a IFN 3/week for 1.2 months. Serum HBV-DNA and HCV-RNA were determined before treatment, after 6-12 months, and at the time of alanine aminotransferase (ALT) flare-up by HBV polymerase chain reaction (PCR) and HCV PCR, respectively. IgM anti-HBc were tested using the IMx Core-M assay (Abbott Laboratories, North Chicago, IL). By the end of treatment, ALT values had become normal in 4/14 HBV-DNA-positive patients (28%), but all "responders" (4/4) relapsed. IgM anti-HBc was detected both before treatment and during ALT elevation in three patients and only during ALT relapse in another three. In the remaining 111 patients, a biochemical response to IFN treatment was observed in 54% and relapse of ALT values in 47%. "Inapparent" HBV/HCV coinfection may be implicated in cases of resistance to IFN. HBV replication and HBV-related liver damage may persist in patients in whom HCV replication was inhibited by current doses of IFN, as suggested also by the presence of IgM anti-HBc in some cases. Further studies will show the effect of different treatment schedules. HBV-DNA and/or IgM anti-HBc detection with very sensitive methods may be important both as a prognostic factor and as a tool for better understanding of intervirus relationships and mechanisms involved in multiple hepatitis virus infections.

Adult↗
PubMed1997

Kinking of the human internal carotid artery: a statistical study in 100 healthy subjects by echocolor Doppler.

BACKGROUND: Kinking of the internal carotid artery is a rather frequent anomaly. It is still controversial whether it has a clinical relevance, causing cerebral vascular disturbances, or if it is a mere morphologic anomaly. A study concerning its frequency in asymptomatic subjects and an evaluation of its possible correlations were, therefore, considered interesting. METHODS: The internal carotid artery was studied in 100 apparently healthy subjects (50 men and 50 women; age range: 18 to 98 years) with no history of atherosclerotic disease of the supra-aortic trunks, or diabetes mellitus, or hypertension. Each patient underwent color Doppler ultrasonography. RESULTS: In 38 subjects out of 100, and in 53 out of 200 examined arteries (100 right and 100 left arteries), a kinking was found (26.5%). In 23 kinkings (43% of all the kinkings), the maximal systolic velocity (MSV) was greater than 1 m/sec at the level of the kinking. The kinkings were more frequent in women; such prevalence was statistically significant. The frequency of kinkings was uncorrelated with the side of the artery, the age, the body weight, the height and the length of the neck. Moreover, the presence of the kinkings was not significantly correlated with the lumen of the internal carotid artery. CONCLUSIONS: Hypotheses regarding the genesis of the kinkings were discussed, and the embryogenic hypothesis was emphasized. The importance of the MSV in the diagnosis of kinkings was stressed.

Adolescent↗
PubMed1996

A novel DNA inversion causing severe hemophilia A.

Almost half of all cases of severe hemophilia A are caused by recurrent DNA inversions, which disrupt the factor VIII (FVIII) gene. These inversions generally occur between a region of intron 22 (int22h) and one of two homologous copies of this region, located 300 to 400 kb telomeric to the FVIII gene. They are routinely detected by a Bcl I Southern blot assay in which the sizes of two of the three normal hybridization bands are characteristically altered. However, atypical hybridization patterns have been observed, and this report describes the first detailed analysis of a hemophilia A patient with such a pattern. The abnormal result was found to be caused by a novel FVIII inversion involving an extra copy of int22h from a site only 70 to 200 kb telomeric of the FVIII gene. Polymerase chain reaction (PCR) allowed one of the inversion junctions to be analyzed, showing that the int22h sequence at this inversion junction was truncated. This patient and his novel inversion provide further evidence that int22h is associated with instability in Xq28.

Base Sequence↗
PubMed1996

Haemophilia B (sixth edition): a database of point mutations and short additions and deletions.

The sixth edition of the haemophilia B database lists in easily accessible form all known factor IX mutations due to small changes (base substitutions and short additions and/or deletions of <30 bp) identified in haemophilia B patients. The 1380 patient entries are ordered by the nucleotide number of their mutation. Where known, details are given on factor IX activity, factor IX antigen in circulation and origin of mutation. References to published mutations are given and the laboratories generating the data are indicated.

Databases, Factual↗
PubMed1996

The molecular basis of haemophilia A and B.

Most families with haemophilia A or B carry gene defects of independent origin. Haemophilia B is mostly due to small changes in the factor IX gene affecting either its transcription, mRNA maturation, mRNA translation or the fine structure of factor IX. Only 2-3% of patients show gross deletions or rearrangements. The great variety of missense mutations reported to cause haemophilia B indicates that this multidomain protein is highly constrained. Less is known about the factor VIII gene as fully efficient mutation detection procedures only became available in 1991. This, however, led to the discovery that almost half the severe cases of haemophilia A or a fifth of all cases are due to frequently occurring inversions caused by homologous intra-chromosome (-chromatid) recombination between repeated sequences 9.5 kb long. Of the three repeats one is in intron 22 of the factor VIII gene and two are 400-500 kb more telomeric. They are 99.8% similar to each other. The spectrum of the other haemophilia A mutations is similar to that of haemophilia B. Since 1983 mounting evidence has shown that in both haemophilias the nature of the mutation is important in predisposing to the inhibitor complication.

Amino Acid Sequence↗
PubMed1996

Two chimaeric transcription units result from an inversion breaking intron 1 of the factor VIII gene and a region reportedly affected by reciprocal translocations in T-cell leukaemia.

Analysis of mRNA in two haemophilic monozygotic twins offers novel information on the organisation of expressed sequences distal to the coagulation factor VIII gene. These patients show an inversion that, in contrast to the common inversions responsible for 1/5 of all haemophilia A, affects the first rather than intron 22 of the gene. This displaces the most telomeric of the factor VIII exons (exon 1) by approximately 100 kb towards the telomere, and close to the region of the C6.1A gene. This novel inversion creates two hybrid transcription units: one formed by the promoter and first exon of the factor VIII gene followed by a widely expressed sequence; the other by the promoter and coding region of the C6.1A gene plus most of the factor VIII gene (part of intron 1 and exons 2-26). Investigation of this transcription unit reveals that the C6.1A gene has an unsuspected intron in the region coding for the previously described 3'-untranslated tail of the message. Furthermore, exons located beyond the known C6.1A sequence and present in normal transcripts precede exons 2-26 of the factor VIII gene in the hybrid mRNA of the haemophilic twins. The factor VIII sequences in this hybrid mRNA are not expected to be expressed because they lack the first exon, encoding the prepeptide, and follow a translation stop in the C6.1A gene. Leukaemia-related translocations in the C6.1A region suggest that this region may be somewhat unstable.

Base Sequence↗
PubMed1995

Ultrarapid mutation detection by multiplex, solid-phase chemical cleavage.

The chemical cleavage of mismatches in heteroduplexes formed by probe and test DNA detects and locates any sequence change in long DNA segments (approximately 1.8 kb), and its efficiency has been well tested in the analysis of both average (e.g., coagulation factor IX) and large, complex genes (e.g., coagulation factor VIII and dystrophin). In the latter application RT/PCR products allow the examination of all essential sequences of the gene in a minimum number of reactions. We use two specific chemical reactants (hydroxylamine and osmium tetroxide) and piperidine cleavage of the above procedure to develop a very fast mutation screening method. This is based on: (1) 5' or internal fluorescent labeling to allow concurrent screening of three to four DNA fragments and (2) solid-phase chemistry to use a microtiter format and reduce the time required for the procedure, from amplification of sequence to gel loading inclusive, to one person-working-day. We test the two variations of the method, one entailing 5' labeling of probe DNA and the other uniform labeling of both probe and target DNA, by detecting 114 known hemophilia B (coagulation factor IX) mutations and by analyzing 129 new patients. Uniform labeling of both probe and target DNA prior to formation of the heteroduplexes leads to almost two-fold redundancy in the ability to detect mutations. Alternatively, the latter procedure may offer very efficient though less than 100% screening for sequence changes with only hydroxylamine. The full method with two chemical reactions (hydroxylamine and osmium tetroxide) should allow one person to screen with virtually 100% accuracy more than 300 kb of sequence in three ABI 373 gels in 1 day.

Base Sequence↗
PubMed1995

Factor VIII gene inversions in severe hemophilia A: results of an international consortium study.

Twenty-two molecular diagnostic laboratories from 14 countries participated in a consortium study to estimate the impact of Factor VIII gene inversions in severe hemophilia A. A total of 2,093 patients with severe hemophilia A were studied; of those, 740 (35%) had a type 1 (distal) factor VIII inversion, and 140 (7%) showed a type 2 (proximal) inversion. In 25 cases, the molecular analysis showed additional abnormal or polymorphic patterns. Ninety-eight percent of 532 mothers of patients with inversions were carriers of the abnormal factor VIII gene; when only mothers of nonfamilial cases were studied, 9 de novo inversions in maternal germ cells were observed among 225 cases (approximately 1 de novo maternal origin of the inversion in 25 mothers of sporadic cases). When the maternal grandparental origin was examined, the inversions occurred de novo in male germ cells in 69 cases and female germ cells in 1 case. The presence of factor VIII inversions is not a major predisposing factor for the development of factor VIII inhibitors; however, slightly more patients with severe hemophilia A and factor VIII inversions develop inhibitors (130 of 642 [20%]) than patients with severe hemophilia A without inversions (131 of 821 [16%]).

Blotting, Southern↗
PubMed1995

The hemophilias.

Explore the source record for details and available documents.

Amino Acid Sequence↗
PubMed1995

Investigation of the factor VIII intron 22 repeated region (int22h) and the associated inversion junctions.

A region of intron 22 of the factor VIII gene, which contains factor VIII-associated gene A (F8A), is repeated twice more nearer the Xq telomere. It has been proposed that intrachromosomal homologous recombination occurs between the intron 22 repeat and either of the two extragenic copies, resulting in the recurrent inversions that cause almost half of all cases of severe haemophilia A. We have precisely defined the repeated region as 9.5 kb of DNA which we have termed int22h (intron 22 homologous region). The junctions of the inversions examined were shown to represent precise exchanges between the int22h repeats, thus providing conclusive evidence for homologous recombination. The three copies of int22h were compared along 8 kb of their length, using chemical mismatch analysis, and found to be 99.9% similar. The presence of such long, almost identical inverted repeats near the Xq telomere could account for the high frequency at which the inversions occur.

Base Sequence↗
PubMed1994

Direct sequencing of PCR-amplified DNA.

This article describes the direct sequencing of PCR-amplified DNA, a technique that bypasses the problem of replication errors sometimes associated with other PCR procedures. The direct sequencing procedure produces an "average sequence" of all the copies of the target. Any miscopied molecule usually represents only a small proportion of the total. The technique described here is based on the "traditional" ddNTP sequencing method of Sanger et al.

Autoradiography↗
PubMed1994

Haemophilia B: database of point mutations and short additions and deletions, fifth edition, 1994.

The fifth edition of the haemophilia B database lists in easily accessible form all known factor IX mutations due to small changes (base substitutions and short additions and/or deletions of < 30bp) identified in haemophilia B patients. The 1,142 patient entries are ordered by the nucleotide number of their mutation. Where known, details are given on: factor IX activity, factor IX antigen in circulation, and origin of mutation. References to published mutations are given and the laboratories generating the data are indicated.

Databases, Factual↗