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Biomedical subjects

C Pozzi

Publications and source records attributed to C Pozzi.

At least 19 recordsLinked to original sources
PubMed2003

Integration of a barley (Hordeum vulgare) molecular linkage map with the position of genetic loci hosting 29 developmental mutants.

The first step in positional gene cloning is the integration into available molecular maps of genetic loci for which mutant alleles exist. We report the placement of 29 barley developmental mutants on a restriction fragment length polymorphism-amplified fragment length polymorphism (RFLP-AFLP) map. The mapping procedure used homozygous mutant F(2) plants in an iterative process: once a mutant linked AFLP was found, primer combinations were successively selected to generate AFLP fragments more tightly linked to the mutant locus. The mutants considered were adp, als, aur-a1, aur-a2, br1, br2, bra-d7, cul3, cul5, cul15, cul16, den6, den8, dub1, hex-v3, hex-v4, int-c5, K, li, lig-a2, lk2, lk5, sld1, sld4, tr, trd, unc, uc2 and uz. The 29 mutant loci were linked to the closest molecular markers by distances ranging from 0 to 23 cM, with an average value of 3.8 cM away. Since the efficiency of the mapping procedure is a function of the density of molecular markers, the RFLP-AFLP map of Castiglioni et al was further integrated with new AFLPs using 87 doubled haploid lines derived from the barley cross Igri x Danilo. A total of 819 mapped AFLP marker loci are now available in the combined map.

Chromosome Mapping↗
PubMed2002

Molecular linkage maps of Vitis vinifera L. and Vitis riparia Mchx.

Two linkage maps for grape (Vitis spp.) have been developed based on 81 F(1) plants derived from an interspecific cross between the wine cultivar Moscato bianco (Vitis vinifera L.) and a Vitis riparia Mchx. accession, a donor of pathogen resistance traits. The double pseudotest-cross mapping strategy was applied using three types of molecular markers. The efficiency of SSRs to anchor homologous linkage groups from different Vitis maps and the usefulness of AFLPs in saturating molecular linkage maps were evaluated. Moreover, the SSCP technique was developed based on sequence information in public databases concerning genes involved in flavonoid and stilbene biosynthesis. For the maternal genetic map a total of 338 markers were assembled in 20 linkage groups covering 1,639 cM, whereas 429 loci defined the 19 linkage groups of the paternal map which covers 1,518 cM. The identification of 14 linkage groups common to both maps was possible based on 21 SSR and 19 AFLP loci. The position of SSR loci in the maps presented here was consistent with other published mapping experiments in Vitis.

Base Sequence↗
PubMed2001

Patterns and symmetries in leaf development.

The leaf is a coordinated mosaic of developmental domains, which are evident from leaf inception on the flanks of the apical meristem. The subdivision of the meristem into molecularly defined domains is regulated by the interactions of a number of gene products and by receptor kinase-mediated signals. The acquisition of symmetry axes in the emerging leaf is a process coordinated by hormones (such as auxin and cytokinins) and the expression of classes of genes (such as the knox and the ARP, as1/rs2/phan, genes). As with simple leaves, the architecture of compound leaves is defined by spatial/temporal gradients of regulatory gene functions: complexity results from the interplay between leaf differentiation processes and genes maintaining a partial level of indeterminacy in the developing primordium. Boundaries between regions with different molecular 'addresses' are considered, in plants as in Drosophila, as organizing centres for lateral organ development.

Body Patterning↗
PubMed2000

Cloning, mapping and expression analysis of barley MADS-box genes.

Six MADS-box cDNA clones were isolated by heterologous screening from a barley inflorescence cDNA library. Based on sequence comparison to known MADS-box genes, the barley MADS-box (BM) genes were grouped into three distinct phylogenetic subclasses of the MADS-box gene family. The three MADS-box genes BM3, BM5 and BM8 share similarities with genes of the SQUAMOSA (SQUA) subgroup, while BM7 and BM9 belong to the AGAMOUS-LIKE 2 (AGL2) subgroup. BM1 resembles MADS-box genes described as solitary sequences or orphan genes. Expression analysis of the barley MADS-box genes revealed expression patterns that are not characteristic of the barley MADS-box genes of the SQUA subgroup. while expression of BM7 and BM9 was largely as expected for the AGL2 subgroup. BM1 is mainly expressed in vegetative tissues and its primary transcript undergoes alternative splicing such that the corresponding mRNAs differ by two codons. The genes BM1, BM3 and BM8 were mapped by analysis of single-nucleotide polymorphisms onto barley chromosomes 4, 2 and 7, respectively.

Alternative Splicing↗
PubMed2000

Genetics of mutations affecting the development of a barley floral bract.

Two groups of mutants that affect the morphology of the lemma, a floral bract of barley, are described. The first comprises phenotypes associated with mutant alleles of calcaroides loci. On the lemma of these mutants, a well-organized neomorphic structure is formed, termed the sac. We provide a morphological description of wild-type (WT) and mutant lemmas, based on scanning electron microscopy (SEM), showing that both consist of similar tissues, but that the mutant is characterized by reversed growth polarity. The sac is a unique structure among grasses, and it is remarkable that recessive mutations at five different genetic loci lead to the same organ. The second group of mutants carry recessive alleles of two leafy lemma genes, both of which are necessary to cause the transformation of the lemma into a structure having all characteristics of a vegetative leaf, as shown by SEM analysis. The presence of sheath, blade, and ligule in the mutant lemma suggests that wild-type lemma development is interrupted at a leaf-like stage. The genes cal a, b, C, d, 23, lel1, and lel2 have now been mapped at precise positions on linkage groups 2, 7, 7, 3, 7, 5, and 7, respectively. The mutants considered in this article are unaffected in other floral organs. A model for lemma development is suggested.

Hordeum↗
PubMed2000

On the origin and domestication history of Barley (Hordeum vulgare).

Remains of barley (Hordeum vulgare) grains found at archaeological sites in the Fertile Crescent indicate that about 10,000 years ago the crop was domesticated there from its wild relative Hordeum spontaneum. The domestication history of barley is revisited based on the assumptions that DNA markers effectively measure genetic distances and that wild populations are genetically different and they have not undergone significant change since domestication. The monophyletic nature of barley domestication is demonstrated based on allelic frequencies at 400 AFLP polymorphic loci studied in 317 wild and 57 cultivated lines. The wild populations from Israel-Jordan are molecularly more similar than are any others to the cultivated gene pool. The results provided support for the hypothesis that the Israel-Jordan area is the region in which barley was brought into culture. Moreover, the diagnostic allele I of the homeobox gene BKn-3, rarely but almost exclusively found in Israel H. spontaneum, is pervasive in western landraces and modern cultivated varieties. In landraces from the Himalayas and India, the BKn-3 allele IIIa prevails, indicating that an allelic substitution has taken place during the migration of barley from the Near East to South Asia. Thus, the Himalayas can be considered a region of domesticated barley diversification.

Base Sequence↗
PubMed2000

Molecular analysis of homeotic genes involved in barley development.

Ectopic expression of the barley homeobox gene BKn-3 conditions the development of epiphyllous flowers by de novo meristem formation. Various strategies are being described in an effort to identify genes whose products interact with the BKn-3 gene product or BKn-3 regulatory regions.

Chromosome Mapping↗
PubMed1999

Corticosteroids in IgA nephropathy: a randomised controlled trial.

BACKGROUND: IgA nephropathy is progressive in most cases and has no established therapy. In this randomised trial, we assessed the efficacy and safety of a 6-month course of steroids in this disorder. METHODS: Between July, 1987, and September, 1995, we enrolled 86 consecutive patients from seven renal units in Italy. Eligible patients had biopsy-proven IgA nephropathy, urine protein excretion of 1.0-3.5 g daily, and plasma creatinine concentrations of 133 micromol/L (1.5 mg/dL) or less. Patients were randomly assigned either supportive therapy alone or steroid treatment (intravenous methylprednisolone 1 g per day for 3 consecutive days at the beginning of months 1, 3, and 5, plus oral prednisone 0.5 mg/kg on alternate days for 6 months). The primary endpoint was deterioration in renal function defined as a 50% or 100% increase in plasma creatinine concentration from baseline. Analyses were by intention to treat. FINDINGS: Nine of 43 patients in the steroid group and 14 of 43 in the control group reached the primary endpoint (a 50% increase in plasma creatinine) by year 5 of follow-up (p<0.048). Factors influencing renal survival were vascular sclerosis (relative risk for 1-point increase in score 1.53, p=0.0347), female sex (0.22, p=0.0163), and steroid therapy (0.41, p=0.0439). All 43 patients assigned steroids completed the treatment without experiencing any important side-effects. INTERPRETATION: A 6-month course of steroid treatment protected against deterioration in renal function in IgA nephropathy with no notable adverse effects during follow-up. An increase in urinary protein excretion could be a marker indicating the need for a second course of steroid therapy.

Administration, Oral↗
PubMed1999

Can prolonged treatment improve the prognosis in adults with focal segmental glomerulosclerosis?

Eighty nephrotic adults with focal segmental glomerulosclerosis (FSGS) and plasma creatinine lower than 3 mg/dL were given corticosteroids (53 patients) or immunosuppressive agents (27 patients) for a median of 16 and 75 weeks, respectively. Forty-two patients responded with complete remission (29 patients, 36%) or partial remission (13 patients, 16%). Twenty-six patients who did not respond were treated again. Two patients obtained complete remission and 13 partial remission. The probability of remission was associated with treatment with corticosteroids (P = 0.0001; RR, 3. 93; 95% CI, 2.00 to 7.72), absence of arterial hypertension (P = 0. 0023; RR, 2.59; 95% CI, 1.41 to 4.79), and a percentage of hyaline glomeruli lower than 5% (P = 0.0152; RR, 2.04; 95% CI, 1.15 to 3.64). The probability of being alive at 110 months without doubling of plasma creatinine was 69%. The risk of renal insufficiency was correlated with mesangial proliferation (P = 0.0025; RR, 5.50; 95% CI, 1.82 to 16.60) and with interstitial fibrosis (P = 0.0231; RR, 4. 44; 95% CI, 1.23 to 16.08) at initial biopsy. Considering partial or complete remission as a time-dependent variable, only the lack of remission (P = 0.0027; RR, 7.23; 95% CI, 1.98 to 26.33) and mesangial proliferation (P = 0.0069; RR, 4.59; 95% CI, 1.52 to 13. 88) were correlated with renal failure. Major side effects were observed in 11 patients (5 infections, 1 peptic ulcer, 2 diabetes, 3 neoplasias). This study shows that 70% of nephrotic adults with FSGS may obtain complete or partial remission and maintain stable renal function for about 10 years when given a prolonged therapy with corticosteroids or immunosuppressive drugs.

Adrenal Cortex Hormones↗
PubMed1999

Chemokine expression by subchondral bone marrow stromal cells isolated from osteoarthritis (OA) and rheumatoid arthritis (RA) patients.

We analysed the spontaneous and cytokine-stimulated production and expression in vitro of IL-8, GROalpha, MCP-1, RANTES, MIP-1alpha, MIP-1beta, by subchondral bone marrow stromal cells (BMSC) isolated from RA, OA, post-traumatic (PT) patients and normal donors (ND). BMSC were cultured in vitro in the presence or absence of IL-1beta and tumour necrosis factor-alpha (TNF-alpha), and assessed for chemokine production, expression and immunolocalization. BMSC from different sources constitutively released MCP-1, GROalpha and IL-8, but not MIP-1alpha or MIP-1beta, while BMSC from ND constitutively released only IL-8 and MCP-1. IL-8, GROalpha and RANTES production in basal conditions was significantly higher in RA patients than in ND. RANTES production was also higher in OA and RA than in PT patients. The combination of TNF-alpha and IL-1beta synergistically increased the production of all chemokines tested except for RANTES. Reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated that all chemokines not detectable in the supernatants were expressed at the mRNA level. Chemokine immunostaining was localized around the nuclei. This work demonstrates that BMSC from subchondral bone produce chemokines and indicates that these cells could actively participate in the mechanisms directly or indirectly causing cartilage destruction and bone remodelling.

Adult↗
PubMed1999

Proinflammatory cytokines and chemokine production and expression by human osteoblasts isolated from patients with rheumatoid arthritis and osteoarthritis.

OBJECTIVE: To evaluate whether subchondral osteoblasts (OB) are involved in the production of cytokines and chemokines in rheumatic diseases. METHODS: OB were isolated from subchondral bone of rheumatoid arthritis (RA), osteoarthritis (OA) and post-traumatic (PT) patients, cultured in vitro in the presence or absence of interleukin 1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), and assessed for the production, immunolocalization, and mRNA expression of proinflammatory cytokines (IL-1alpha, IL-1beta, TNF-alpha) and alpha and beta chemokines [IL-8, growth related gene product (GRO-alpha), monocyte chemoattractant protein 1 (MCP-1), RANTES, and macrophage inflammatory proteins MIP-1alpha, MIP-1beta]. RESULTS: Cultured OB from different patients did not release IL-1alpha, IL-1beta, or TNF-alpha, and constitutively secreted IL-8, GRO-alpha, and MCP-1, while RANTES, MIP-1alpha, MIP-1beta were undetectable or near the lower level of sensitivity of the immunoenzymatic assay. GRO-alpha was significantly higher in RA than in OA and PT patients. IL-1beta and TNF-alpha alone or in combination strongly stimulated chemokine release by OB. Only RANTES production was not increased by the combination of the 2 cytokines. IL-1alpha, IL-1beta, and TNF-alpha were expressed as cytoplasmic proteins and were not secreted by OB even after stimulation. CONCLUSION: OB from subchondral bone release chemokines that could be involved in the mechanisms that directly or indirectly cause bone remodelling and cartilage destruction.

Aged↗
PubMed1999

[Acute biliary pancreatitis. Therapeutic trends].

BACKGROUND: Treatment of biliary pancreatitis includes suppression of the biliary cause by cholecystectomy and common bile duct clearance. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy for eradication of biliary stones and laparoscopic cholecystectomy (L.C.) for residual gallbladder stones would be ideal but were once considered to be contraindicated by most surgeons. The timing of definitive biliary tract surgery and the role of ERCP have been the focus of discussion in recent years. METHODS: During a two-year study period 51 patients with acute biliary pancreatitis were studied. Seven patients (14%) underwent emergency laparotomy, necrosectomy, cholecystectomy, exploration of the common bile duct and T-tube insertion, because unstable clinical conditions, with evidence of pancreatic and peripancreatic necrosis on CT-scan. Elective open cholecystectomy and CBD exploration were performed in 7 patients after the resolution of acute pancreatitis during the same hospital admission. RESULTS: Early ERCP and L.C. were associated with favourable outcomes. 33 patients underwent ERCP preoperatively: 17 within 72 hours of admission and 16 after signs of clinical improvement. Laparoscopic cholecystectomy performed 3-25 days after admission was successful in 27 of 29 patients. Postsphincterectomy bleeding occurred in one patient and was treated successfully by endoscopic epinephrine injection. For median hospital stay and recurrence there were statistical differences between early and delayed ERCP. CONCLUSIONS: ERCP and sphincterectomy have a certain role in conjunction with laparoscopic cholecystectomy in the management of patients with acute biliary pancreatitis, particularly in institutions where there is easy access to expert interventional endoscopic techniques. This policy should reduce the risk of cholangitis and recurrent pancreatitis.

Acute Disease↗
PubMed1998

Different pattern of cytokine production and mRNA expression by lymphoid and non-lymphoid cells isolated from human palatine tonsil.

To investigate the cytokines involved in the interaction between circulating (B and T lymphocytes) and non-circulating (stromal cells) elements present in lymphoid tissue, highly purified populations were isolated from human tonsils and the cytokine production and mRNA expression (interleukin-1 alpha, -2, -4, -5, -6, -8, -10, leukocyte inhibitory factor, granulocyte-macrophage colony-stimulating factor, and interferon-gamma) were assessed both by immunoassay and reverse transcriptase polymerase chain reaction under resting conditions and after activation with tumor necrosis factor-alpha. Under basal conditions most cytokines were not detected, except for interleukin-8 which was produced by T lymphocytes and lymphoid cells. Activation by tumor necrosis factor-alpha induced interleukin-8 production by B lymphocytes. Tonsillar T lymphocytes expressed mRNA for interleukin-1 alpha, -8, -10, -4, leukocyte inhibitory factor, and interferon-gamma, only interleukin-4 was expressed by resting peripheral blood T lymphocytes. Tonsillar B lymphocytes were mRNA positive for interleukin-1 alpha, -8, -10, leukocyte inhibitory factor, and interferon-gamma, these were not expressed by peripheral blood B lymphocytes. Stromal cells constitutively produce interleukin-6 whose levels increased 5 times upon tumor necrosis factor-alpha activation Granulocyte-macrophage colony-stimulating factor and interleukin-8 were detected only after tumor necrosis factor-alpha activation. Only stromal cells constitutively express interleukin-6 and granulocyte-macrophage colony-stimulating factor and show a cytokine pattern different from that described for other non-lymphoid cells, such as follicular dendritic cells. These data indicate that in the human tonsil population, lymphoid and non-lymphoid cells can be distinguished by different patterns of cytokine expression.

Child, Preschool↗
PubMed1998

Exposure of prehospital providers to violence and abuse.

INTRODUCTION: Before 1994, violence toward EMS personnel was informally recognized but was the subject of only limited scientific investigation. Confrontations with EMS personnel in the out-of-hospital workplace appear to involve verbal and physical assaults, injuries, disabilities, and mental stresses and often seem to go unreported. Without formal recognition of violent encounters, EMS agencies are unlikely to implement appropriate policies, procedures, or training to deal with this issue. This article focuses on quantifying the current existence of violence toward EMS personnel, as well as violence-related policies and appropriate training at EMS agencies. METHODS: A survey was administered to a convenience sample from the Albuquerque Fire Department. Surveys were completed by 331 respondents. Validity was measured per question response. Descriptive statistics analyzed question responses. RESULTS: Ninety percent of the 331 EMS personnel who responded stated that an assault or violent action had been directed toward them during their EMS work career. In a forced choice ranking of the 13 most stressful parts of their EMS job, abusive and violent situations were listed as the number 1 stressor. According to 71% of respondents, no clear protocols existed to handle abusive situations. Seventy-one percent of respondents reported that abusive situations were considered a "part of their job" and that they lacked the training to learn how to protect themselves. After experiencing an assault, 80% of respondents felt angry and 69% felt irritable. DISCUSSION: Prehospital providers will encounter violent and abusive situations while on the job. Violence-related policies, associated training, and reporting systems were not in place for the Albuquerque Fire Department in 1995. With a 90% exposure to violence, combined with the lack of training or policies about violence, the potential for work-related injuries and liabilities is evident. Management personnel need violence education to understand the scope of the problem. Violence reporting should be consistent and be encouraged, according to "Guidelines for Preventing Workplace Violence for Health Care and Social Workers" from the Occupational Safety and Health Administration.

Clinical Competence↗
PubMed1998

An AFLP-based procedure for the efficient mapping of mutations and DNA probes in barley.

A strategy based upon AFLP markers for high-efficiency mapping of morphological mutations and DNA probes to linkage groups in barley is presented. First, 511 AFLP markers were placed on the linkage map derived from the cross Proctor x Nudinka. Second, loci controlling phenotypic traits were assigned to linkage groups by AFLP analysis, using F2 populations consisting of 30-50 mutant plants derived from crosses of the type "mutant x Proctor" and "mutant x Nudinka." To map DNA probes, 67 different wild-type barley lines were selected to generate F2 populations by crossing with Proctor and Nudinka. F2 plants that were polymorphic for a given RFLP fragment were classified into genotypic classes. Linkage of the RFLP polymorphism to 1 of the 511 AFLP loci was indicated by cosegregation. The use of the strategy is exemplified by the mapping of the mutation branched-5 to chromosome 2 and of the DNA probes Bkn2 and BM-7 to chromosomes 5 and 1, respectively. Map expansion and marker order in map regions with dense clustering of markers represented a particular problem. A discussion considering the effect of noncanonical recombinant products on these two parameters is provided.

Alleles↗