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Biomedical subjects

A Frattini

Publications and source records attributed to A Frattini.

At least 19 recordsLinked to original sources

Liposome-delivered angiostatin strongly inhibits tumor growth and metastatization in a transgenic model of spontaneous breast cancer.

The possibility to inhibit tumor growth by interfering with the formation of new vessels, which most neoplasias depend on, has recently raised considerable interest. An angiogenic switch, in which proliferating cells acquire the ability to direct new vessel formation, is thought to be an early step in the natural history of solid tumors. Using a transgenic model of breast cancer, which shows many similarities to its human counterpart, including ability to metastasize, we targeted angiostatin production to an early stage of tumor formation. Liposome-delivered angiostatin considerably delayed primary tumor growth and, more importantly, inhibited the appearance of lung metastases. These findings can be relevant to the design of therapeutic intervention in humans.

Angiostatins↗

Defects in TCIRG1 subunit of the vacuolar proton pump are responsible for a subset of human autosomal recessive osteopetrosis.

Osteopetrosis includes a group of inherited diseases in which inadequate bone resorption is caused by osteoclast dysfunction. Although molecular defects have been described for many animal models of osteopetrosis, the gene responsible for most cases of the severe human form of the disease (infantile malignant osteopetrosis) is unknown. Infantile malignant autosomal recessive osteopetrosis (MIM 259700) is a severe bone disease with a fatal outcome, generally within the first decade of life. Osteoclasts are present in normal or elevated numbers in individuals affected by autosomal recessive osteopetrosis, suggesting that the defect is not in osteoclast differentiation, but in a gene involved in the functional capacity of mature osteoclasts. Some of the mouse mutants have a decreased number of osteoclasts, which suggests that the defect directly interferes with osteoclast differentiation. In other mutants, it is the function of the osteoclast that seems to be affected, as they show normal or elevated numbers of non-functioning osteoclasts. Here we show that TCIRG1, encoding the osteoclast-specific 116-kD subunit of the vacuolar proton pump, is mutated in five of nine patients with a diagnosis of infantile malignant osteopetrosis. Our data indicate that mutations in TCIRG1 are a frequent cause of autosomal recessive osteopetrosis in humans.

Alternative Splicing↗

Identification and genomic organization of a gene coding for a new member of the cell adhesion molecule family mapping to Xq25.

The gene coding for a new member of the Immunoglobulin (Ig)-like domain-containing molecule superfamily has been identified and mapped to the human Xq25 chromosomal band. It contains 12 Ig-like domains in two clusters of 5 and 7 motifs, respectively, separated by a linker segment, followed by a transmembrane and a cytoplasmic region. The gene is conserved in mammals and is expressed in muscle, heart, brain, testis, and pancreas with transcripts of different length, suggesting that it is subjected to alternative processing. The transcript is assembled from 19 exons which are distributed along approx. 20kb; each Ig-like domain is contained in distinct exons which constitute the unit of repeated genomic duplications. Elucidation of the IGDC1 genomic structure will allow the investigation of the basis of its alternative transcription and of its possible involvement in diseases mapped to the Xq25 interval.

Alternative Splicing↗

Partial V(D)J recombination activity leads to Omenn syndrome.

Genomic rearrangement of the antigen receptor loci is initiated by the two lymphoid-specific proteins Rag-1 and Rag-2. Null mutations in either of the two proteins abrogate initiation of V(D)J recombination and cause severe combined immunodeficiency with complete absence of mature B and T lymphocytes. We report here that patients with Omenn syndrome, a severe immunodeficiency characterized by the presence of activated, anergic, oligoclonal T cells, hypereosinophilia, and high IgE levels, bear missense mutations in either the Rag-1 or Rag-2 genes that result in partial activity of the two proteins. Two of the amino acid substitutions map within the Rag-1 homeodomain and decrease DNA binding activity, while three others lower the efficiency of Rag-1/Rag-2 interaction. These findings provide evidence to indicate that the immunodeficiency manifested in patients with Omenn syndrome arises from mutations that decrease the efficiency of V(D)J recombination.

Amino Acid Sequence↗

In vitro and in vivo antisense-mediated growth inhibition of a mammary adenocarcinoma from MMTV-neu transgenic mice.

Oncogene-bearing transgenic mice develop various kinds of tumors depending on both the regulatory sequences and the specific oncogene used. These mice not only help to clarify the pathogenetic pathways leading to tumor formation, but can also be useful as models to test novel therapeutic strategies, including gene therapy. We have previously reported the establishment of an MMTV-neu (ErbB-2) transgenic mouse lineage, in which 100% of females develop breast tumors with many features similar to their human counterparts; these tumors are due to the over-expression of the activated rat neu oncogene in the mammary gland. From one such mouse we established a cell line of mammary adenocarcinoma named MG1361. We report here that the growth of this cell line can be inhibited in vitro and in vivo by transfection of a plasmid vector carrying an antisense anti-neu construct. This inhibitory effect is specific, as it is related to the expression of the antisense transgene (determined by RT-PCR), and to a reduction in neu mRNA and protein, as determined by Northern and Western blot analyses. Moreover, inoculation of cells carrying the antisense or the control vector in nude mice demonstrated that the morphological and biochemical effects elicited by the antisense construct resulted in a significantly slower rate of in vivo growth of tumor xenografts. Finally, significant mammary tumor growth inhibition was obtained after liposome-mediated direct inoculation of the same antisense vector in tumors spontaneously arising in MMTV-neu mice. Taken together, these findings suggest that targeting neu expression by an integrated large anti-neu antisense segment affects the in vivo growth of these tumors.

Adenocarcinoma↗

Identification of a new member (ZNF183) of the Ring finger gene family in Xq24-25.

Four genes were mapped to the Xq24-25 region by searching the EST and the non-redundant database with short tracts of genomic sequences. These were random STSs present in the STS database or sequences derived from CpG islands (EagI-based STSs). One of the four matches corresponded to the full length transcript from the intronless glutamate dehydrogenase gene. The second was the human homolog of the bovine NADH ubiquinone oxidoreductase MWFE subunit gene (GDB symbol: NDUFA1). The other two, ZNF183 and ITBA4, were novel genes whose function cannot directly be inferred from their sequence analysis. However, a known motif, the C3HC4 Ring finger domain, shared by various tumor suppressors, DNA repair genes and cytokine receptor-associated molecules, is present at the C terminus of the ubiquitously expressed ZNF183 gene. ITBA4 is expressed at various levels in different tissues and is alternatively processed in brain. Similarity search did not detect any significant match in databases. These results, together with others previously reported by our laboratory, suggest that comparison of genomic and transcribed sequences which are continuously accumulating in databases, can provide 'virtual' mapping of a substantial number of ESTs to the specific genomic region which the STSs have been derived from.

Amino Acid Sequence↗

[Major complications of percutaneous nephrolithotripsy (PCNL). Analysis of our cases].

The major complications occurred in 140 cases of percutaneous nephrolithotomy, from March 1988 to December 1996 are studied. They were: 1 important hemorrhage with secondary nephrectomy, 1 intestinal fistula resolved with parenteral therapy, 1 hyponatriemic syndrome which required an intraperitoneal drainage and 1 global kidney functional exclusion after 3 months. Etiopathogenesis and suggestions for prevention are discussed as well as the necessity of adequate training.

Aged↗

Computer gene mapping by Eagl-based STSs.

The rapid pace at which the human genome project has proceeded has greatly benefited from two classes of short sequence tags, genomic (STS) and transcribed (EST), which are listed in two separate databases. Usually, STSs are random genomic sequences derived only for mapping purposes, while ESTs represent transcribed sequences that have to be mapped one by one. Here, we propose a way of establishing links between these two sets of sequences, allowing the automatic mapping of EST sequences by simple comparison with relatively nonrandom STSs. We suggest that EagI-based STSs derived by selected genomic portions organized in YAC contigs can automatically finely map a relevant portion of the ESTs, partially bridging the gap between the two sets of sequences and saving a great amount of time in mapping efforts. To test this principle, we have selected 330 high-quality STSs derived from the Xq24-qter region and used them for transcript searches by comparing them to the EST as well as to the nonredundant database. This search detected four known genes and two additional EST clones. In contrast, when the same databases were searched with a set of 53 sequences derived from the same chromosomal region around EagI sites, 7 known genes and 6 additional ESTs were found. These findings, together with data obtained from simulation analysis on long sequences in the same chromosomal region, suggest that EagI-based STSs can partially bridge the gap between STSs and ESTs.

Chromosome Mapping↗

The ZNF75 zinc finger gene subfamily: isolation and mapping of the four members in humans and great apes.

We have previously reported (Villa et al. (1993), Genomics 18: 223) the characterization of the human ZNF75 gene located on Xq26, which has only limited homology (less than 65%) to other ZF genes in the databases. Here, we describe three human zinc finger genes with 86 to 95% homology to ZNF75 at the nucleotide level, which represent all the members of the human ZNF75 subfamily. One of these, ZNF75B, is a pseudogene mapped to chromosome 12q13. The other two, ZNF75A and ZNF75C, maintain an ORF in the sequenced region, and at least the latter is expressed in the U937 cell line. They were mapped to chromosomes 16 and 11, respectively. All these genes are conserved in chimpanzees, gorillas, and orangutans. The ZNF75B homologue is a pseudogene in all three great apes, and in chimpanzee it is located on chromosome 10 (phylogenetic XII), at p13 (corresponding to the human 12q13). The chimpanzee homologue of ZNF75 is also located on the Xq26 chromosome, in the same region, as detected by in situ hybridization. As expected, nucleotide changes were clearly more abundant between human and orangutan than between human and chimpanzee or gorilla homologues. Members of the same class were more similar to each other than to the other homologues within the same species. This suggests that the duplication and/or retrotranscription events occurred in a common ancestor long before great ape speciation. This, together with the existence of at least two genes in cows and horses, suggests a relatively high conservation of this gene family.

Amino Acid Sequence↗

Characterization and fine localization of two new genes in Xq28 using the genomic sequence/EST database screening approach.

Two new genes were identified and mapped by searching the EST databases with genomic sequences obtained from putative CpG islands of the rodent-human hybrid X3000. Previous mapping of these CpG islands in the proximity of the host cell factor (HCFC1) and GdX genes automatically localized these two new genes to Xq28 in the interval between the L1 cell adhesion molecule (L1CAM) and the glucose-6-phosphate dehydrogenase (G6PD) loci. Both genes are relatively short, contain an ORF of 261 and 105 amino acids, respectively, and are ubiquitously expressed. Combining sequencing of selected CpG islands, derived from hybrids containing small portions of the human genome, with an EST database search is an easy method of identifying and mapping new genes to specific regions of the genome.

Amino Acid Sequence↗

The complete sequence of the host cell factor 1 (HCFC1) gene and its promoter: a role for YY1 transcription factor in the regulation of its expression.

We report here the complete sequence of the Host Cell Factor (HCFC1) gene, including two kilobases of the 5'-flanking region and 5.9 kb of the first intron. The upstream and 5'-untranslated regions contain several putative transcriptional factor binding sites and a 17-nt-long repeated element (SiSa element) present in six regularly spaced copies, of which five are perfectly identical, while the sixth has a transition substitution (CT for TC) at nucleotides 13 and 14. Four copies are contained in the flanking region, the fifth is at the beginning of the mRNA (position +9), and the sixth is at position 195 of the mRNA. This 17-bp element contains at its 5' side an octamer sequence known to bind the Yin/Yang 1 (YY1) transcription factor; another YY1 binding octamer is present at the end of the first intron. The promoter also contains several Sp1 binding sites, some of which are located very close to SiSa elements. We demonstrate that YY1 binds to the 5' half of the SiSa element, whose 3' region binds in gel shift experiments an additional, as yet unidentified nuclear factor. Therefore the YY1 binding site in HCFC1 overlaps the site of a second factor, as has been described in several YY1-site-containing promoters. This suggests that HCFC1 expression might be regulated by the reciprocal interaction of several transcription factors.

Base Sequence↗

The chromosome localization and the HCF repeats of the human host cell factor gene (HCFC1) are conserved in the mouse homologue.

The gene encoding the human host cell factor (HCFC1) has recently been cloned and mapped to Xq28. HCFC1 codes for a family of related polypeptides that apparently arise from posttranslational processing. Six extremely conserved 19-amino-acid (aa)long motifs, unique to HCFC1 and located in the middle of the protein, could play a role in this processing or could be instrumental to the physiological role of the protein. Aternatively, these repeats could have arisen from recent duplications and may not have any specific function. To resolve this issue, we cloned the homologous region from the mouse HCFC1 gene and demonstrated that the 19-aa motifs are extremely conserved in sequence, number, and genomic organization, while the "linker" region between the third and fourth repeat is not. This suggests an important function for these repeats. In addition, by RT-PCR analysis of human RNA and comparison to the human genomic sequence, an alternative transcript including a 44-aa in-frame insertion, deriving from the 3' end of intron 18, was found. The significance of this alternative transcript is unknown, since it was not detectable in the mouse. The mouse HCFC1 gene maps to a region syntenic to Xq28, and, as in human, is in close proximity to the Renin-binding protein gene, in a 100-kb region also including the Licam and Vasopressin receptor type 2 genes.

Amino Acid Sequence↗

[Gittes' pubovaginal suspension in the treatment of stress urinary incontinence (SUI)].

Since the 1993, a series of 22 women with stress urinary incontinence underwent bladder neck suspension, according to Gittes (pubovaginal suspension). No patients had preoperative detrusor instability or intrinsic sphincter dysfunction; 14 pts had a significant cystocele (II-III degree). We followed up 20 pts at 6 months: 9 pts (45%) were cured, 3 were significantly improved and 8 were not improved. Disappearance or marked improvement of moderate or severe cystocele wasn't confirmed in all pts. No serious complications were recognized. We believe that this procedure is quick and easy to perform with low morbidity and is useful where the indication is correct: patients with stress incontinence without significant anterior vaginal wall prolapse.

Aged↗

Mutations of Jak-3 gene in patients with autosomal severe combined immune deficiency (SCID).

Severe combined immune deficiency (SCID) represents a heterogenous group of hereditary diseases. Mutations in the common gamma-chain (gamma c), which is part of several cytokine receptors including those for interleukin (IL)-2, IL-4, IL-7, IL-9 and IL-15, are responsible for X-linked SCID, which is usually associated with a lack of circulating T cells and the presence of B lymphocytes (T- B+ SCID). The gene(s) responsible for autosomal recessive T- B+ SCID is still unknown. The Jak-3 protein kinase has been found to associate with the gamma c-chain-containing cytokine receptors. Therefore Jak-3 or other STAT proteins with which it interacts are candidate genes for autosomal recessive T- B+ SCID. Here we investigate two unrelated T- B+ SCID patients (both from consanguineous parents) who have homozygous mutations in the gene for Jak-3. One patient carries a mutation (Tyr100-->Cys) in a conserved tyrosine residue in the JH7 domain of Jak-3 which is absent in more than 150 investigated chromosomes. The other patient carries a homozygous 151-base-pair deletion in the kinase-like domain, leading to a frameshift and premature termination. Both mutations resulted in markedly reduced levels of Jak-3. These findings show that abnormalities in the Jak/STAT signalling pathway can account for SCID in humans.

B-Lymphocytes↗

The human genes encoding renin-binding protein and host cell factor are closely linked in Xq28 and transcribed in the same direction.

The Xq28 chromosomal band represents a C+G-rich region onto which several genes have been mapped. In most cases, the exact relationship between the mapped genes has not yet been established, and neither the regulatory nor the spacer regions between the various transcription units have been defined. In the region around the L1CAM gene (encoding L1 cell adhesion molecule), the transcription units appear, from preliminary analyses, to be quite compact. By sequencing the region at the 3' end of the recently found host cell factor 1-encoding gene (HCFC1), we report that the renin-binding protein-encoding gene (RBP) major transcription start point lies 2763 bp downstream from the 3' end of HCFC1 and that both are transcribed in the same direction from the telomere to the centromere.

Base Sequence↗

[Rouxel-Coadou method of ileal neobladder: clinico-functional considerations].

Twelve patients are submitted to orthotopic ileal neobladder, performed using staplers. The simplicity and speed of automatic stapling devices in the Rouxel-Coadou's surgical technique are reported. All patients underwent clinical and urodynamic evaluation at 3, 6, 12 months, after surgery (mean follow-up 6 months). They preferred complete daytime continence and 2 pts/4 night-time continence too. At one year, postvoid residual volume was absent, mean neobladder capacity was 450 ml and mean pressure at maximum capacity was 30-40 cm H2O. These preliminary results indicate that this technique guarantees a low-pressure reservoir with good capacity and compliance.

Adult↗

[The current role of surgery in renal calculi].

We report our experience on 63 patients submitted to kidney stone surgery, between january '88 and june '94, at the Division of Urology, in Parma (Italy). Nowadays percutaneous lithotripsy (PCNL) and extracorporeal shock wave lithotripsy (ESWL) permit the resolution of lithiasic disease in more than 90% of the cases; in fact, the incidence of open surgery in only about 1-12%. At the present, the role of traditional surgery is also directed to resolution of damages of endourological and extracorporeal failures, as post-traumatic events. We want to emphasize, as now, that essential surgical approach to kidney surgery is lacking in the aim of young urologists training.

Contraindications↗