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Biomedical subjects

G Bucci

Publications and source records attributed to G Bucci.

At least 19 recordsLinked to original sources
PubMed2002

Ultrastructural basis for the efficiency of an ileal orthotopic neobladder 27 years after surgery.

The morphological and functional basis of the excellent clinical outcome of ileal orthotopic neobladders are largely unknown. Only long-term follow-up studies will provide an adequate answer to this unsettled question. We have studied a patient who underwent this type of surgery over 27 years ago. Besides an important secretive adaptation we have found, at the ultrastructural level, that the monolayered epithelium does not show signs of true metaplasia and that changes had occurred in the intercellular junctions, namely that desmosomes are significantly increased. Although limited to a single case, these features, if confirmed by further observations, suggest a working hypothesis for the understanding of the definitive phenotypic adaptation of the ileal epithelium to the new aggressive environment.

Aged↗
PubMed2000

Delineation of genetic zones in the European Norway spruce natural range: preliminary evidence.

We applied geostatistics to previously reported chloroplast simple sequence repeats (cpSSR) haplotype frequency data from 95 European Norway spruce populations to provide preliminary evidence about the following issues: (i) delineation of genetically homogeneous regions ('genetic zones'); (ii) prediction of their haplotype frequencies and definition of related criteria to be applied for provenance identification and certification of seedlots; (iii) identification of putative allochthonous stands; and (iv) construction of a continental-scale 'availability map' of the intraspecific biodiversity for Norway spruce. Direct evidence of large-scale geographical structure over the European natural range was obtained, detecting both geographical clines and stationary patterns. The increase of the mean genetic divergence by geographical distance (up to approximately 1800 km apart) provided a strong hint that geographical distance is a major factor of differentiation in Norway spruce. Haplotype frequency surfaces were obtained by applying ordinary kriging to sampling frequency data. Cluster analysis carried out on haplotype frequency surfaces revealed a fair discrimination among 16 genetic zones, with an accuracy of 0.916. Dendrogram analysis carried out on the predicted mean haplotype frequency confirmed a fairly good separability of the genetic zones detected. Reclassification of populations by discriminant analysis confirmed the robustness of the genetic subdivision obtained. Combining the information from discriminant analysis and cross-validation of sampling points, three populations likely to be of nonlocal origin were identified. The application of geostatistical analysis to genetic marker data is discussed in relation to breeding activities and to the formulation of appropriate conservation strategies.

Cluster Analysis↗
PubMed2000

Chloroplast microsatellite analysis reveals the presence of population subdivision in Norway spruce (Picea abies K.).

Three chloroplast microsatellites (cpSSRs), previously sequence characterized and for which paternal inheritance was tested and confirmed, were used to assess their usefulness as informative markers for phylogeographic studies in Norway spruce (Picea abies K.) and to detect spatial genetic differentiation related to the possible recolonization processes in the postglacial period. Ninety-seven populations were included in the survey. Some 8, 7, and 6 different size variants for the three cpSSRs, respectively, were scored by analysing 1105 individuals. The above 21 variants combined into 41 different haplotypes. The distribution of some haplotypes showed a clear geographic structure and seems to be related to the existence of different refugia during the last glacial period. The analysis of chloroplast SSR variation detected the presence of two main gene pools (Sarmathic-Baltic and Alpine--Centre European) and a relatively low degree of differentiation (RST of about 10%), characteristic of tree species with large distribution and probably influenced by an intensive human impact on this species. Based on our data, we were not able to detect any evidence concerning the existence of additional gene pools (e.g., from Balkan and Carpathian glacial refugia), though we cannot exclude the existence of genetic discontinuity within the species' European range. A large proportion of population-specific haplotypes were scored in this species, thus indicating a possible usefulness of these markers for the identification of provenances, seed-lots, and autochthonous stands.

DNA, Chloroplast↗
PubMed1999

Comparing the effects of nasal synchronized intermittent positive pressure ventilation (nSIPPV) and nasal continuous positive airway pressure (nCPAP) after extubation in very low birth weight infants.

In this study we hypothesized that nasal synchronized intermittent positive pressure ventilation (nSIPPV) would provide more ventilatory support than nasal continuous positive airway pressure (nCPAP) in the immediate post-extubation period in very low birth weight (VLBW) infants. We tested this hypothesis by comparing the effects of these two ventilatory techniques on ventilation, gas exchange, and patient inspiratory effort in 11 preterm infants immediately after extubation. All neonates studied (BW: 1141+/-(SEM) 53 g; GA: 28.1+/-(SEM) 0.5 wks) had received mechanical ventilation because of respiratory distress at birth and were extubated by day 14 of life. Nasal SIPPV and nCPAP were applied in random order to each infant after extubation so that each was his/her own control. Both nCPAP and nSIPPV were delivered at end-expiratory pressures (PEEP) of 3 cm H2O. Inspiratory times (Ti) and peak inspiratory pressures set during nSIPPV were the same as those used at the time of extubation. Recordings lasted 45 min in each mode of ventilation. Tidal volume (Vt), minute volume (Ve), respiratory rate (RR), airway pressure (Paw), transcutaneous PO2 (TcPO2) and PCO2 (TcPCO2) as well as phasic esophageal pressure deflections (Pe), as an estimate of inspiratory effort, were measured. The measurements obtained during both modes of ventilation indicated significant differences between the two techniques. Indeed, application of nSIPPV was associated with a statistically significant increase in Vt and Ve. In addition, Pe decreased by 30% during nSIPPV (P<0.01). TcPCO2 was statistically significantly lower during nSIPPV than nCPAP, and RR as well. These data therefore suggest that nSIPPV may provide more ventilatory support than nCPAP in the post-extubation period with less patient inspiratory effort.

Humans↗
PubMed1999

Histological adaptation of orthotopic ileal neobladder mucosa: 4-year follow-up of 30 patients.

OBJECTIVE: For 4 years we have monitored the histological evolution of ileal neobladders in a single cohort of 30 patients in order to systematically describe the histological changes occurring after surgery. The aim of the study was to evaluate the long-term evolution of many histological parameters with functional relevance as to the metabolic outcome of the reservoirs. METHODS: Ileal samples were collected during surgery and by random biopsies during cystoscopy 6, 12, 18, 24, 36 and 48 months later. At each step qualitative and quantitative assessment of the histological and cytological conditions of the samples was carried out. RESULTS: Morphological changes develop relatively early but the situation tends to level out in about 1 year. The morphological changes are topographically uneven and, although mucosal flattening becomes progressively prevalent, areas with shortened villi persist indefinitely. Goblet cells prevail over enterocytes and the secretive pattern shifts towards sialomucins. The overall replication rate decreases initially but tends to restore in 1 year. Dysplasia or atrophy were never recorded. CONCLUSIONS: The 4-year systematic follow-up revealed a typical histological adaptation pattern in the ileal neobladder without signs of dysplasia. The changes seem to be induced by the aggressive environment and develop in the time lag required for functional adaptation of the epithelium.

Adult↗
PubMed1998

Histomorphology of an ileal orthotopic neobladder: 24 Year's follow-up.

No morphological data are so far available about long-term (over 15 years) adaptation and outcome of ileal neobladders. In this single case report we have studied a 72-year-old man who underwent reconstruction of an ileal neobladder 24 years ago. The ileal epithelium shows changes toward a colonic aspect with villous atrophy and increased goblet cell number although, as in normal ileum, sialomucins are the most abundant secretory products. Neuroendocrine cells are reduced to a few elements of a single morphological class. Even in the presence of a low apoptotic rate reduced cell proliferation causes mucosal thinning. These adaptive mechanisms grant an excellent clinical and functional result even beyond 20 years after surgery. It is suggested that ileal neobladder can constitute an important model for the study of epithelial differentiation control.

Aged↗
PubMed1997

Ureaplasma urealyticum and pulmonary outcome in a neonatal intensive care population.

OBJECTIVE: To determine whether the presence of Ureaplasma urealyticum in the respiratory tracts of very low birth weight infants is associated with increased risk of pneumonia, radiographic evidence of severe bronchopulmonary dysplasia during the second or third week of life (precocious) and oxygen dependency at 36 weeks of corrected postnatal gestational age. METHODS: From October, 1993, to January, 1996, all infants who met the following entry criteria were enrolled in the study: birth weights < or = 1500 g; admission to the NICU within 24 h after birth; evidence on admission of respiratory distress; and no prior antibiotic treatment. Infants were cultured for mycoplasmas, viruses, chlamydiae and aerobic and anaeroic bacteria. RESULTS: Ninety-four critically ill newborns constituted our study cohort. Within 7 days of birth more infants with U. urealyticum infection showed radiographic features of pneumonia (53.1%, 25 of 47) than infants without U. urealyticum infection (21.2%, 10 of 47). Infants with U. urealyticum were more likely to have radiographic evidence of precocious bronchopulmonary dysplasia than those without this isolate (22.5%, 9 of 40 vs. 2.3%, 1 of 42). The relative risk of oxygen dependency at 36 weeks of corrected age in U. urealyticum-positive infants was 11.0 times that in U. urealyticum-negative infants (95% confidence interval, 1.6 to 75.5). Association of U. urealyticum and chronic lung disease at this age was not weakened after adjustments were made in a multivariate analysis for other significant risk factors including gestational age and presence of a patent ductus arteriosus. CONCLUSIONS: Isolation of U. urealyticum from respiratory tracts is associated with radiographic changes compatible with pneumonia within 7 days of birth, precocious bronchopulmonary dysplasia and severe pulmonary outcome.

Bronchopulmonary Dysplasia↗
PubMed1995

Pneumocystis carinii pneumonia in preterm infants: report of two cases successfully diagnosed by non-bronchoscopic bronchoalveolar lavage.

We present two cases of Pneumocystis carinii pneumonia in apparently immunocompetent preterm infants presenting with unexplained respiratory distress associated with a predominantly interstitial process on the chest radiograph. Definite diagnosis was promptly established on the detection of cyst forms in the lung fluid obtained by non-bronchoscopic bronchoalveolar lavage, and a favourable outcome was achieved.

Bronchoalveolar Lavage↗
PubMed1994

Apoptosis is dependent on intracellular zinc and independent of intracellular calcium in lymphocytes.

Changes in intracellular Ca2+ concentration ([Ca2+]i) are believed to have a crucial role in triggering apoptosis, the process whereby cells are eliminated during tissue turnover, hormone-mediated tissue reabsorption, clonal selection in the thymus, T cell-mediated cytotoxic reactions, and many other physiological and pathological processes. In the present report we have explored the role of intracellular Ca2+ and Zn2+ in the regulation of apoptosis in peripheral blood lymphocytes (PBL). Unless they were stimulated by a mitogen, e.g., phytohemagglutinin (PHA), PBL showed typical apoptotic changes (nuclear condensation and DNA fragmentation) after a 48- to 72-h culture. Neither a sustained nor a transient increase in [Ca2+]i induced by the Ca2+ ionophore ionomycin in the presence or absence of extracellular Ca2+, respectively, was able to trigger DNA fragmentation. On the contrary, [Ca2+]i chelation to a level 10- to 20-fold lower than physiological resting levels induced DNA cleavage into nucleosome-size DNA fragments. DNA cleavage was also induced by incubation in the presence of the intracellular, membrane-permeant Zn2+ chelator N,N,N',N'-tetrakis(2-pyridyl-methyl)ethylenediamine. Total intracellular Zn2+ content was increased by mitogenic stimulation with PHA and decreased by treatment of PBL cultures with dexamethasone or extracellular ATP, stimuli known to trigger apoptosis in lymphocytes. Our results suggest that Zn2+ rather than Ca2+ could be a key intracellular regulator of apoptosis.

Apoptosis↗
PubMed1993

Segregation analysis of random amplified polymorphic DNA (RAPD) markers in Picea abies Karst.

The reliability of arbitrarily primed amplification products was tested. The segregation analysis of 266 amplification products obtained using 17 different 10-mer oligonucleotides in 34 megagametophytes from a single tree of Picea abies was carried out. Fifty-four out of the 165 variable bands fit the 1:1 segregation ratio expected for Mendelian traits. The segregation ratio of a subset of six RAPD markers in five other individuals from the same population confirmed their genetic nature. Our results strengthen the evidence previously reported that RAPDs markers can be considered Mendelian traits useful in the detection of genetic variability among both different individuals and populations.

Base Sequence↗
PubMed1992

Chlamydia trachomatis in neonatal respiratory distress of very preterm babies: biphasic clinical picture.

We observed 12 very preterm infants (10 males) with a peculiar respiratory syndrome characterized by early onset soon after birth and by a biphasic course. The severe first phase was characterized by a clinical pattern mimicking the idiopathic respiratory distress syndrome of prematurity. Gradually, respiratory symptoms decreased and assisted ventilation with oxygen therapy was reduced. In the second phase, a significant worsening of respiratory signs and the appearance of apneic spells were observed. Chest X-ray showed hypoexpansion of the lungs and the prevalence of a fine reticular pattern. Chlamydia trachomatis was identified in this second phase in conjunctival and pharyngeal swabs and/or on tracheal aspirates. Our data suggest that in the very preterm infants, chlamydial infection shows different clinical and laboratory features if compared with Chlamydia trachomatis pneumonia of infants born at term.

Anti-Bacterial Agents↗
PubMed1992

[Mortality and care level of very low birth weight newborn infants. A population study].

A population study on 314 very low birth weight infants (VLBW) was carried out in 1987 in the Lazio Region of Italy to investigate the relation between the availability at birth of neonatal intensive care and infant mortality. Fifty-two percent of VLBW infants did not survive the first year of life. The mortality Odds Ratios, adjusted for four potential confounding variables, did not show a beneficial effect of Maternity units with neonatal intensive care (level 3) compared with those with special (level 2) and normal care (level 1). The overall high crude mortality rate together with the homogeneity of odds ratios among the different levels of care suggest that, when a regionalized perinatal care system is missing, as in Lazio region, the availability of neonatal intensive care, per se, does not improve the survival on this group of infants.

Female↗