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Biomedical subjects

F Gennari

Publications and source records attributed to F Gennari.

16 recordsLinked to original sources

Mapping of the apple scab-resistance gene Vb.

Apple scab, caused by the fungus Venturia inaequalis, is the major production constraint in temperate zones with humid springs. Normally, its control relies on frequent and regular fungicide applications. Because this control strategy has come under increasing criticism, major efforts are being directed toward the breeding of scab-resistant apple cultivars. Modern apple breeding programs include the use of molecular markers, making it possible to combine several different scab-resistance genes in 1 apple cultivar (pyramiding) and to speed up the breeding process. The apple scab-resistance gene Vb is derived from the Siberian crab apple 'Hansen's baccata #2', and is 1 of the 6 "historical" major apple scab-resistance genes (Vf, Va, Vr, Vbj, Vm, and Vb). Molecular markers have been published for all these genes, except Vr. In testcross experiments conducted in the 1960s, it was reported that Vb segregated independently from 3 other major resistance genes, including Vf. Recently, however, Vb and Vf have both been mapped on linkage group 1, a result that contrasts with the findings from former testcross experiments. In this study, simple sequence repeat (SSR) markers were used to identify the precise position of Vb in a cross of 'Golden Delicious' (vbvb) and 'Hansen's baccata #2' (Vbvb). A genome scanning approach, a fast method already used to map apple scab-resistance genes Vr2 and Vm, was used, and the Vb locus was identified on linkage group 12, between the SSR markers Hi02d05 and Hi07f01. This finding confirms the independent segregation of Vb from Vf. With the identification of SSR markers linked to Vb, another major apple scab-resistance gene has become available; breeders can use it to develop durable resistant cultivars with several different resistance genes.

Ascomycota↗

T-cell engineering by a chimeric T-cell receptor with antibody-type specificity for the HIV-1 gp120.

Immune-based approaches of cell therapy against viral pathogens such as the human immunodeficiency virus type 1 (HIV-1) could be of primary importance for the control of this viral infection. Here, we designed a chimeric cell surface receptor (105TCR) to provide primary human T-lymphocytes with antibody-type specificity for the HIV-1 envelope glycoprotein. This receptor includes the single chain Fv domain of the neutralizing anti-gp120 human monoclonal antibody F105, CD8alpha hinge and the transmembrane and the cytoplasmic domains of TCRzeta. Our results show that 105TCR is expressed at the cellular surface and is capable of recognizing the HIV-1 envelope glycoprotein inducing highly efficient effector T-cell responses, including extracellular signal-regulated kinase phosphorylation and cytokine secretion. Moreover, human primary CD8+ T-lymphocytes transduced by oncoretroviral and lentiviral vectors containing the 105TCR gene are able to mediate in vitro-specific cytolysis of envelope-expressing cells and HIV-1-infected CD4+ T-lymphocytes. These findings suggest that 105TCR is particularly suited for in vivo efficacy studies.

Animals↗

Identification by genome scanning approach (GSA) of a microsatellite tightly associated with the apple scab resistance gene Vm.

For all known major apple scab resistance genes except Vr, molecular markers have been published. However, the precise position of some of these genes, in the apple genome, remains to be identified. Knowledge about the relative position of apple scab resistance genes is necessary to preliminarily evaluate the probability of success of their pyramidization. Pyramidization of different resistance genes into the same genotype is a reliable way to create cultivars with durable apple scab resistance. Applying the genome scanning approach (GSA), we identified the linkage group of the scab resistance gene Vm, derived from Malus micromalus, and we found a new molecular marker tightly associated with the gene. The simple sequence repeat Hi07h02, previously mapped on linkage group 17, cosegregates with the Vm gene (no recombinants in the 95 plants tested). The already published sequence-characterized amplified region Vm marker OPB12(687) was found to be linked at about 5 cM from the resistance gene and, therefore, this marker also maps on linkage group 17 of apple. This is the first report of the discovery of a major apple scab resistance gene on linkage group 17. The advantages of using GSA for the identification of molecular markers for qualitative traits are discussed.

Alleles↗

Sequential liver-kidney transplantation.

The indications for sequential liver and kidney transplantation have not been well defined. Two categories of patients may benefit from this procedure: patients with primary renal disease associated with hepatic disorders (glomerulonephritis, tubulointerstitial nephritis, metabolic diseases, and structural diseases) and patients who develop renal failure after liver transplantation. Chronic renal failure is a frequent long-term complication after liver transplantation. End-stage renal disease develops in 2% to 10% of cases by 10 years after transplantation. Kidney transplantation appears to be a better option than dialysis for the treatment of end-stage renal disease after liver transplantation. In contrast, survival rates, after kidney transplantation are significantly lower among liver transplant patients than primary-only kidney transplant recipients. Considering the donor shortage, kidney transplantation should be cautiously considered in liver transplantation patients. New immunosuppressive drugs and protocols are needed to reduce chronic renal failure after liver transplantation.

Humans↗

Genetically modified immunocompetent cells in HIV infection.

Even in the era of highly active antiretroviral therapy (HAART), gene therapy (GT) can remain a promising approach for suppressing HIV infection, especially if complemented with other forms of pharmacological and immunological intervention. A large number of vectors and targets have been studied. Here we discuss the potential of genetically treated, antigen-specific immunocompetent cells for adoptive autologous immunotherapy of HIV infection. Cellular therapies with gene-modified CD8 and CD4 lymphocytes are aimed at reconstituting the antigen-specific repertoires that may be deranged as a consequence of HIV infection. Even if complete eradication of HIV from the reservoirs cannot be achieved, reconstitution of cellular immunity specific for opportunistic pathogens and for HIV itself is a desirable option to control progression of HIV infection and AIDS pathogenesis better.

AIDS-Related Opportunistic Infections↗

Rational reconstitution of the immune repertoire in AIDS with autologous, antigen-specific, in vitro-expanded CD4 lymphocytes.

HIV infection leads to decrease of CD4 lymphocytes. In particular, loss of CD4 cells specific for opportunistic pathogens results in active opportunistic infections, that are the chief cause of morbidity and mortality in AIDS. Highly active anti-retroviral therapy (HAART) has been shown to have dramatic effects in a large fraction of treated individuals, such as decrease of viral load and increase of CD4 cells. It has not been clearly established, though, whether CD4 cells that appear during HAART represent a functional repertoire (i.e. a CD4 repertoire that encompasses all specificities, including T-cells responding to opportunistic pathogens, as in immunocompetent individuals) or an amplified mirror image of a defective repertoire. Therefore we propose that the immune repertoire can be reconstituted with autologous CD4 lymphocytes collected at early stages of infection, selected for specificity for opportunistic pathogens, expanded and stored for future use when laboratory or clinical signs indicate a depletion of antigen-specific CD4 cells. Since the reinfused CD4 cells are themselves susceptible to HIV infection-replication, we suggest that in vitro gene therapy of these cells may confer a genetic resistance that is permanently maintained in these cells.

Acquired Immunodeficiency Syndrome↗

Living-related liver transplantation: is Doppler sonography sufficient to define the hepatic artery anatomy before surgery?

OBJECTIVE: to evaluate the accuracy of colour Doppler sonography (CDS) in the assessment of the left hepatic arterial supply in living donors before hepatic transplantation. MATERIAL AND METHODS: Pre-operative sonographic Doppler data of the left hepatic artery (LHA) were compared retrospectively with the selective hepatic angiographic data and the intra-operative observations in 60 living donors. RESULTS: Pre-operative Doppler data of the LHA were available in 53 cases and incomplete or absent in seven cases. In 51 cases (96%) the origin of the LHA or an accessory LHA were correctly described at Doppler sonography (44 classical LHA in anatomic position, seven accessory LHA). In 11 cases (21%), Doppler data were insufficient or incorrect to define the arterial supply of the hepatic segments II, III and IV. Doppler studies were unable to determine the length or the diameter of the LHA. CONCLUSION: Doppler sonography seems to be able to define the main left hepatic artery anatomy. Selective hepatic angiography is still indicated to determine the length, diameter and intra-hepatic segmental supply.

Hepatic Artery↗

Early hormonal and surgical treatment of cryptorchidism.

PURPOSE: We investigated the efficacy of early gonadotropin treatment of cryptorchidism for promoting testicular descent and ameliorating testicular histology. MATERIALS AND METHODS: We treated 319 cryptorchid testes in 281 boys 4 months to 3 years old with luteinizing hormone-releasing hormone and human chorionic gonadotropin sequential therapy. Surgery was done on the 207 testes that did not respond to medical treatment. Microscopic biopsies were performed in 134 of these 207 testes. Histological findings were compared to those of 30 cryptorchid testes in boys younger than 1 year who underwent surgery without previous hormonal treatment. RESULTS: Combined luteinizing hormone-releasing hormone and human chorionic gonadotropin treatment induced scrotal descent of a percentage of cryptorchid testes depending on clinical position. Therapeutic success was greater when testes were in a lower position and results were not age dependent. Hormonal treatment of cryptorchidism during the first year of life stimulated spermatogonia maturation. CONCLUSIONS: When administered at the end of age 6 months, hormonal treatment can be considered an effective and timely substitution for gonadotropin and testosterone insufficiency in cryptorchid infants. Therefore, we recommend this therapeutic procedure combined with surgery in the first year of life.

Age Factors↗

The nature of uncoupling by n-hexane, 1-hexanethiol and 1-hexanol in rat liver mitochondria.

We have analyzed the effects of n-hexane, 1-hexanethiol, and 1-hexanol on the coupled respiration of rat liver mitochondria. Incubation of mitochondria with n-hexane, 1-hexanethiol and 1-hexanol resulted in a stimulation, at low concentrations, and an inhibition, at high concentrations, of the state 4 mitochondrial respiration. Three criteria, all based on the comparison with the effect of DNP, have been used to establish whether the stimulation of respiration, at low concentrations of n-hexane, 1-hexanethiol, and 1-hexanol, depends on protonophoric mechanisms. First, the quantitative relationship between the extents of respiratory stimulation and membrane potential depression: a strong decrease of membrane potential was induced by increasing concentrations of DNP and a negligible depression by increasing concentrations of n-hexane or 1-hexanethiol. Only a slight decrease was induced by 1-hexanol. Second, the quantitative relationship between the extents of respiratory stimulation and of proton conductance increase: at equivalent rates of respiration, the enhancement of the proton conductance induced by DNP was very marked, by n-hexane and 1-hexanethiol practically negligible, and by 1-hexanol much smaller than that induced by DNP. Third, in titrations with redox inhibitors of the proton pumps, the pattern of the relationship between proton pump conductance and membrane potential was markedly different from protonophoric and non-protonophoric uncouplers: almost linear in the case of DNP, highly non-linear in the case of n-hexane, 1-hexanethiol and 1-hexanol. These three criteria support the view that n-hexane, 1-hexanethiol, and partially 1-hexanol, uncouple mitochondrial respiration by a non-protonophoric mechanism.

2,4-Dinitrophenol↗

Nature of respiratory stimulation in hyperthyroidism: the redox behaviour of cytochrome c.

Hyperthyroid mitochondria show an increased Km and Vmax in the high affinity phase of cytochrome oxidase kinetics. During inhibitor titrations, cytochrome c shows a different redox behaviour in hyperthyroid with respect to protonophore-treated euthyroid mitochondria. The observations are discussed in terms of a different regulation of electron input and output into the respiratory chain during slip and leak types of uncoupling. In hyperthyroid mitochondria during inhibitor titrations, the pattern of the relationship between uncoupler-induced extra-respiration and membrane potential is highly non-linear. The complex nature of the respiratory stimulation in hyperthyroid mitochondria is discussed.

Animals↗

Non-palpable testes. Orchiopexy in single stage.

From 1986 to 1990, 53 non-palpable testes were treated in the department of Pediatric Surgery and Endocrinology at the Regina Margherita Hospital, Turin, Italy. The reported patients were 45, 8 of them were bilateral with both testes non-palpable, 13 of the remaining patients were right cryptorchid and 24 were left. All patients received medical treatment, by LH-RH nasal spray and HCG, before surgery. None of the non-palpable testes descended by hormone therapy only, so that surgical exploration was always required. In the 53 reported cases, 10 gonads were not found, 13 were atrophic and 30 were abdominal. All abdominal gonads were positioned into the scrotum by orchiopexy in a single stage. Half of the patients underwent operation before the age of 2. Therefore, it is to be pointed out that the younger a patient the shorter his inguinal canal, this facilitates orchiopexy for high, undescended testes. In 10 patients a testicular biopsy was made during surgical procedure. Normal morphology and normal spermatogonia content were observed in the abdominal testes of the patients who had reached the age of 1 year. During the follow-up of the reported patients no upward displacement was observed. Eleven patients underwent postoperative testicular ultrasonography which showed that parenchymal structure of the operated testis was normal and the volume of the testis was slightly smaller than normal. Based on their experience, the authors suggest to correct cryptorchidism before the age of one year, surgical procedure follows immediately after ineffective hormone therapy.

Child, Preschool↗

Surgical treatment of cryptorchidism.

In the last 12 years, 916 cryptorchid testes have been treated sequentially with therapeutic and surgical procedures. Although the age of the boys varied considerably at the time that corrective procedures commenced, the best results were obtained when they were in the first year of life. The testes of the boys at this age who had been treated had a normal histology; this was not the case of those who were treated at an age older than one year.

Age Factors↗

Isolated liver transplantation in an infant with ultrashort gut.

Intestinal function in children with very short bowel syndrome and related intestinal failure may improve after isolated liver transplantation. An infant with an ultrashort gut, ileo-cecal valve, and whole colon received total parenteral nutrition from the first days of life. Enteral feeding failed because of the progressive dilatation of the jejunal portion and motility disorders. He developed early severe cholestatic liver disease (aspartate transferase 186, alanine transferase 103 U/L, serum bilirubin 8.4 mg/dL) and subsequent liver failure. At 8 months of age, he benefited from isolated liver transplantation (left segment graft from living donor). His early posttransplant evolution was characterized by recovery of oral alimentation, improvement of digestive and absorption functions, but he did not achieve TPN-independence. At 20 months, 50% to 60% of his energy needs were covered by parenteral nutrition and he has satisfactory growth indices (3rd percentile for weight and height), reduced stool volume, and frequency. Isolated liver transplantation allowed, in this particular case, time for further intestinal adaptation thereby avoiding the need for intestinal transplantation early in life.

Digestion↗

The pediatric liver transplant program at the Université Catholique de Louvain, Cliniques Saint-Luc, Brussels: overall results in 444 children (1984-1997).

Between 1984 and 1997, a total of 444 children (< 15 years) received an orthotopic liver transplant (OLT) at Saint-Luc University Clinics. Biliary atresia constituted the indication for OLT in 304 cases (68%). Median age (range) at OLT was 2.1 years (0.3-14.5). 177 children (40%) received a whole liver graft, 184 (41%) a reduced-size graft, 26 (6%) a split liver graft, whereas a living-related donor graft was used in 57 children (13%). Most grafts were ABO-identical or -compatible, in 395 cases (89%) and 40 (9%), respectively. Overall actuarial patient survivals at one and five years were 85% and 81%. The overall retransplantation rate was 19%. The results of uni- and multivariate statistical analyses showed a significant impact of year of transplantation (learning curve effect), with a 15% improvement of patient survival between the 1984-7 and the 1995-7 periods (p < 0.002). Results differed according to the indications for OLT, the best survivals being recorded for familial cholestasis, the worst for liver tumor (p = 0.004). Five year patient survival was significantly better after elective OLT (82%), when compared to highly urgent OLT (63%) (p < 0.001). Patient survivals were comparable in the children receiving primary cyclosporin-A microemulsion or tacrolimus immunosuppression, which were significantly higher than in the historical group treated with cyclosporin-A. No impact of the age at OLT, type of graft and ischemic time could be reported. In conclusion, this series illustrates the progressive improvements introduced in our pediatric liver transplant program between 1984 and 1997, including the technical variants allowing pediatric OLT using adult donors as well as the introduction of new immunosuppressive strategies.

Actuarial Analysis↗

[A neonatal ovarian cyst associated with transient endocrine anomalies].

The authors present a case of enormous neonatal ovarian cyst associated with ipoglicemia, ipotiroidism and ipocalcemia. This baby presents also stenosis of the pulmonary artery and congenital dysplasia of the hip. The case is interesting because this type of association is unusual and has not been described before.

Abdomen↗