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C Dani

Publications and source records attributed to C Dani.

At least 55 records · Page 3Linked to original sources
PubMed1999

Risk factors for the development of respiratory distress syndrome and transient tachypnoea in newborn infants. Italian Group of Neonatal Pneumology.

Respiratory distress syndrome (RDS) and transient tachypnoea (TT) are the most frequent acute respiratory diseases in the newborn. This study investigated the risk factors for RDS and TT in newborn infants. A population of 63,537 newborns was enrolled in a 12-month survey in Italy, 734 (1.15%) affected by RDS and 594 (0.93%) affected by TT. Multivariate regression analysis of maternal and perinatal data and the calculation of odds ratios (with 95% confidence intervals) were performed. It was demonstrated that gestational age, birthweight, maternal age, elective and emergency caesarean section (CS), and male sex were risk factors for RDS, while gestational age, maternal diseases, twinning, birthweight, operative vaginal delivery, elective and emergency CS, and male sex were risk factors for TT. The data confirm previous reports and demonstrate that advanced maternal age is a risk factor for RDS, while ruling out maternal diseases as independent risk factors for RDS.

Adult↗
PubMed1999

A role for preadipocytes as macrophage-like cells.

Several lines of evidence have supported a link betweeen adipose tissue and immunocompetent cells. This link is illustrated in obesity, where excess adiposity and impaired immune function have been described in both humans and genetically obese rodents. In addition, numerous factors involved in inflammatory response are secreted by both preadipocytes and macrophages. Here we show that proliferating preadipocytes in cell lines and primary cultures, develop phagocytic activity toward microorganisms. This is demonstrated by phagocytosis assays and confocal microscopy. This function disappears when preadipocytes stop proliferating and differentiate into adipocytes. After phagocytosis, preadipocytes show microbicide activity via an oxygen-dependent mechanism. In addition, preadipocytes as well as adipocytes are stained with MOMA-2, a marker of monocyte-macrophage lineage, but are negative for specific mature macrophage markers (F4/80 and Mac-1). These results suggest that preadipocytes could function as macrophage-like cells and raise the possibility of a potential direct involvement of adipose tissue in inflammatory processes.

Adipocytes↗
PubMed1999

Embryonic stem cell-derived adipogenesis.

Key events leading to terminal differentiation of preadipocytes into adipocytes have been characterized in the recent years. However, master genes that commit progression from multipotent mesenchymal stem cell to the adipoblast stage of development have not yet been identified. The use of embryonic stem (ES) cells as a route to study early events in adipogenesis and to characterize factors involved in the decision of stem cells to follow the adipogenic pathway is described in this paper. The capacity of lif-/- and lifr-/- ES cells to undergo adipocyte differentiation is reported as an application of mutant ES cells to study gene function during the development of adipose cells.

Adipose Tissue↗
PubMed1998

Paracrine induction of stem cell renewal by LIF-deficient cells: a new ES cell regulatory pathway.

The propagation of pluripotential mouse embryonic stem (ES) cells is sustained by leukemia inhibitory factor (LIF) or related cytokines that act through a common receptor complex comprising the LIF receptor subunit (LIF-R) and the signal transducer gp130. However, the findings that embryos lacking LIF-R or gp130 can develop beyond gastrulation argue for the existence of an alternative pathway(s) governing the maintenance of pluripotency in vivo. In order to define those factors that contribute to self-renewal in ES cell cultures, we have generated ES cells in which both copies of the lif gene are deleted. These cells showed a significantly reduced capacity for regeneration of stem cell colonies when induced to differentiate, confirming that LIF is the major endogenous regulatory cytokine in ES cell cultures. However, self-renewal was not abolished and undifferentiated ES cell colonies were still obtained in the complete absence of LIF. A differentiated, LIF-deficient, parietal endoderm-like cell line was derived and shown to support ES cell propagation via production of a soluble, macromolecular, trypsin-sensitive activity. This activity, which we name ES cell renewal factor (ESRF), is distinct from members of the IL-6/LIF family because (i) it is effective on ES cells lacking LIF-R; (ii) it is not blocked by anti-gp130 neutralizing antibodies; and (iii) it acts without activation of STAT3. ES cells propagated clonally using ESRF alone can contribute fully to chimaeras and engender germline transmission. These findings establish that ES cell pluripotency can be sustained via a LIF-R/gp130-independent, STAT-3 independent, signaling pathway. Operation of this pathway in vivo could play an important role in the regulation of pluripotency in the epiblast and account for the viability of lifr -/- and gp130 -/- embryos.

Animals↗
PubMed1998

Acute neonatal respiratory distress in Italy: a one-year prospective study. Italian Group of Neonatal Pneumology.

A prospective multicentre 12-month survey of neonatal respiratory disorders in 63 537 Italian infants was performed to evaluate the incidence of acute neonatal respiratory disorders and of the main related complications. A total of 1427 developed respiratory disorders (2.2%), 208 of whom died (14.6%). The incidence of respiratory distress syndrome was 1.16%, with a case fatality rate (CFR) of 24%; that of transient tachypnoea was 0.93%, with a CFR of 1.3%. The rates of meconium aspiration syndrome, persistent pulmonary hypertension and pneumonia were 0.06%, 0.02% and 0.07%, with CFRs of 10.3%, 38.5% and 21.7%, respectively. The occurrences of the main complications in affected newborns were: bronchopulmonary dysplasia 5.6%, necrotizing enterocolitis 1.7%, patent ductus arteriosus 9.8%, 3 degrees and 4 degrees grade intraventricular haemorrhage 6.8% and air leak 4.9%. It was concluded that the incidence of acute neonatal respiratory disorders and the main related complications was lower than that reported two decades ago and that the CFR of acute neonatal respiratory disorders had increased. These results may be the consequences of (i) progress in the management of high-risk pregnancies, (ii) an increased number of viable infants with extremely low birth weight and (iii) diffusion of antenatal treatment with corticosteroids which, in this series, seemed to reduce the morbidity but not the mortality in the high-risk infants.

Acute Disease↗
PubMed1998

Epidemiology of neonatal acute respiratory disorders. A multicenter study on incidence and fatality rates of neonatal acute respiratory disorders according to gestational age, maternal age, pregnancy complications and type of delivery. Italian Group of Neonatal Pneumology.

A prospective 3-month survey of neonatal respiratory disorders in 17,192 Italian infants born in 65 hospitals, located in 17 Italian regions representative of northern, central and southern Italy, was performed to evaluate the incidence of neonatal acute respiratory disorders and their risk factors. The prematurity rate was 7.3%, while the extremely low birth weight (< 1,000 g) and very low birth weight (< 1,500 g) rates were 0.58% and 0.99%, respectively. Four hundred and ninety-one infants (2.8%) developed respiratory signs. Lethality or specific fatality rate (SFR) for acute respiratory disorders with regard to the overall study population was 0.45%. The male/female ratio of affected infants was 1.3:1. Among affected newborns the case fatality rate (CFR) for respiratory disorders was 15.88% (78/491) and was higher in males than in females (2:1), in infants with a gestational age of < or = 28 weeks (60%) and birth weights of < 1,000 g (50%). Moreover, the SFR was higher (p < 0.05) in the infants of mothers older than 34 years. SFR was 3.0% in intrauterine growth-retarded infants, 3.6% in the first twin and 3.2% in the second twin. An Apgar score of < or = 3 at 5 min was strongly related to the incidence of respiratory disorders (47.1%). The antenatal prevention of neonatal respiratory distress syndrome with maternal corticosteroid treatment was performed in 84% of newborns (< 32 weeks) with respiratory problems in northern Italy, and about 25% and 38% in central and southern Italy, respectively. The CFR was double in southern Italy as compared with northern and central Italy. Prematurity, low birth weight and a low Apgar score (< or = 3) at 1 and 5 min as well as a maternal age of > 34 years are risk factors for acute respiratory disorders.

Acute Disease↗
PubMed1997

Antenatal ambroxol treatment does not prevent the respiratory distress syndrome in premature infants.

UNLABELLED: The effectiveness of ambroxol in the prevention of neonatal respiratory distress syndrome and in reducing the need for intermittent mandatory ventilation and oxygen therapy was studied in 88 mothers whose infants was born between 24 and 34 weeks of gestation and who were randomized either for treatment with ambroxol (group A = 42) or served as control (group B = 46). There were no significant differences in the mean gestational age, birth weight or Apgar score between the two groups. We found no significant differences in occurrence of respiratory distress syndrome (55% vs 45%), in support by intermittent mandatory ventilation (71% vs 72%) or oxygen therapy (74% vs 75%) at 12 h of age between groups A and B. CONCLUSION: This study does not suggest the efficacy of antenatal ambroxol treatment both for the prevention of neonatal respiratory distress syndrome and for the reduction of its severity.

Ambroxol↗
PubMed1997

Leptin gene is expressed in rat brown adipose tissue at birth.

The ob gene product leptin is secreted from adipose tissue. Leptin has dramatic effects on food intake and energy expenditure in rodents. Brown adipose tissue is the first form of adipose tissue to appear during development, and is present at birth in most species. The development of a leptin feedback system in early life and the relative role of the brown and white adipose tissues have not yet been revealed. We have investigated the expression of ob/leptin mRNA in brown adipose tissue around birth and with respect to feeding. Northern blotting analysis and in situ hybridization experiments demonstrated the presence of leptin mRNA in brown adipose tissue at 0, 18, and 24 h after birth. The leptin mRNA level was decreased at 8 h postpartum in fed animals and at 18 or 24 h in the absence of feeding. In addition, circulating leptin was detected in the plasma of newborn rats at 0, 10, or 24 h after birth, whereas it was not detectable in 10 h-old animals that did not suckle at their mother. The presence at birth of ob mRNA and circulating leptin, as well as the early effect of suckling on ob mRNA levels, suggests the precocious involvement of leptin in the control of food intake.

Adipose Tissue, Brown↗
PubMed1997

Differentiation of embryonic stem cells into adipocytes in vitro.

Embryonic stem cells, derived from the inner cell mass of murine blastocysts, can be maintained in a totipotent state in vitro. In appropriate conditions embryonic stem cells have been shown to differentiate in vitro into various derivatives of all three primary germ layers. We describe in this paper conditions to induce differentiation of embryonic stem cells reliably and at high efficiency into adipocytes. A prerequisite is to treat early developing embryonic stem cell-derived embryoid bodies with retinoic acid for a precise period of time. Retinoic acid could not be substituted by adipogenic hormones nor by potent activators of peroxisome proliferator-activated receptors. Treatment with retinoic acid resulted in the subsequent appearance of large clusters of mature adipocytes in embryoid body outgrowths. Lipogenic and lipolytic activities as well as high level expression of adipocyte specific genes could be detected in these cultures. Analysis of expression of potential adipogenic genes, such as peroxisome proliferator-activated receptors gamma and delta and CCAAT/enhancer binding protein beta, during differentiation of retinoic acid-treated embryoid bodies has been performed. The temporal pattern of expression of genes encoding these nuclear factors resembled that found during mouse embryogenesis. The differentiation of embryonic stem cells into adipocytes will provide an invaluable model for the characterisation of the role of genes expressed during the adipocyte development programme and for the identification of new adipogenic regulatory genes.

Adipocytes↗
PubMed1997

Adverse effects of prenatal glucocorticoid treatment in the preterm infant.

Several studies suggest that glucocorticoids given to the mother at risk for preterm delivery, reduce the incidence of respiratory distress syndrome, intraventricular hemorrhage, bronchopulmonary dysplasia and mortality. Only 20% of pregnancies at risk for preterm delivery are actually treated with steroids: this reluctance may be due to the theoretical adverse effect of this therapy in the mother and the newborn. Our aim was to review the studies performed during the past two decades to assess the risk/benefit ratio of antenatal steroid treatment in the preterm infant.

Animals↗
PubMed1996

Expression of ob gene in adipose cells. Regulation by insulin.

The product of the recently cloned mouse obese (ob) gene is likely to play an important role in a loop regulating the size of the adipose tissue mass. The hormonal regulation of the ob gene could affect adiposity. To investigate this point, the effect of insulin on ob gene expression was examined in cells of the 3T3-F442A preadipocyte clonal line. ob mRNA is absent from exponentially growing, undifferentiated cells as well as from confluent preadipose cells. Terminal differentiation of preadipose to adipose cells leads to the expression of ob mRNA detected by a sensitive and quantitative ribonuclease protection assay. In adipose cells, the level of ob mRNA is sensitive to insulin in the nanomolar range of concentrations with an increase from an average of 1 copy to 5-10 copies/cell. The effect of insulin was fully reversible and takes place primarily at a transcriptional level. The ob mRNA shows a rapid turnover, with a half-life of approximately 2 h in the absence or presence of insulin. The level of secreted Ob protein is also regulated by insulin. These results indicate that the ob gene is expressed in mature fat cells only and support the possibility that insulin is an important regulator of ob gene expression.

3T3 Cells↗
PubMed1995

Increased expression in adipocytes of ob RNA in mice with lesions of the hypothalamus and with mutations at the db locus.

The gene product of the recently cloned mouse obese gene (ob) is important in regulating adipose tissue mass. ob RNA is expressed specifically by mouse adipocytes in vivo in each of several different fat cell depots, including brown fat. ob RNA is also expressed in cultured 3T3-442A preadipocyte cells that have been induced to differentiate. Mice with lesions of the hypothalamus, as well as mice mutant at the db locus, express a 20-fold higher level of ob RNA in adipose tissue. These data suggest that both the db gene and the hypothalamus are downstream of the ob gene in the pathway that regulates adipose tissue mass and are consistent with previous experiments suggesting that the db locus encodes the ob receptor. In db/db and lesioned mice, quantitative differences in expression level of ob RNA correlated with adipocyte lipid content. The molecules that regulate expression level of the ob gene in adipocytes probably are important in determining body weight, as are the molecules that mediate the effects of ob at its site of action.

Adipocytes↗
PubMed1995

Oxygen saturation in premature neonates with bronchopulmonary dysplasia in a hammock.

Premature neonates with bronchopulmonary dysplasia (BPD) frequently present borderline hypoxemia and the risk for oxygen desaturation may increase in relation to the posture. Our aim was to see if infants with BPD experience severe hypoxemia (SaO2 < 85%) in a hammock, a 'containing' posture considered advantageous to neuromotor and relational development of the preterm. Fifteen pulse oximetry recordings (Ohmeda B105 3760 Pulse Oximeter) were obtained in 15 subjects (range of gestational age and postnatal age 27-30 and 33-48 weeks, respectively; range of birth weight and body weight at entrance to the study 0.64-1.35 and 0.97-2.24 kg, respectively) before, during and after placement in a hammock; each testing period lasted 15 min, and each baby served as his or her own control. BPD preterm infants were receiving oxygen therapy by continuous flow standard nasal cannulas (FiO2 > 25%, < 40%). The analysis of the data, that have a rough gaussian distribution, indicates a worsening of SaO2 in the hammock position. In fact, mean +/- SEM, median and range of the SaO2 values in pre- and posthammock position are comparable, but are significantly different at 99.9% confidence level (CL) in prehammock vs. hammock posture and at 98% CL in posthammock vs. hammock posture. Moreover, the percent of time with SaO2 < 85% during the periods recorded increased about 10 +/- 5% in a hammock (24 +/- 4%), in comparison to pre- (14 +/- 3%) and posthammock position (15 +/- 3%). These results suggest that oxygen-dependent BPD preterm infants in the hammock posture may experience severe hypoxemia that in part limits the possible advantages of the 'containment'.

Bronchopulmonary Dysplasia↗
PubMed1995

Methylxanthines increase renal calcium excretion in preterm infants.

To determine the effect of a short course of methylxanthines on renal function and on urinary calcium excretion, 20 premature neonates affected by apnea or moderate respiratory distress syndrome were randomly assigned to either a theophylline treatment or to a caffeine treatment group. The protocol included a 24-hour pretreatment study period (I) and a subsequent 24-hour period (II) following 5 days of theophylline (loading dose 5 mg/kg i.v., maintenance dose 2.5 mg/kg/12 h) or caffeine (loading dose 10 mg/kg i.v., maintenance dose 2.5 mg/kg/12 h) administration. Pre- and postxanthine treatment serum sodium, potassium, calcium and phosphorus remained stable, while serum creatinine decreased significantly (p < 0.05). Furthermore, from period I to period II, sodium urine excretion, fractional Na excretion and creatinine clearance remained statistically comparable in both study groups, along with a significant increase (p < 0.05) in calciuria, urinary Ca/creatinine and urinary Ca/Na. Predose caffeine and theophylline serum levels, assessed on the 5th day of treatment, were 12.8 +/- 1.8 and 7.9 +/- 1.7 micrograms/ml, respectively. Compared to control healthy untreated prematures, the studied premature infants showed a statistically significant increase in urine calcium excretion (10- to 15-fold), which was more evident in the theophylline group. Our data suggest further investigation to determine the long-term renal effects of methylxanthines in premature neonates, to improve assessment of the risk of nephrocalcinosis and osteopenia, in particular in association with various diuretic therapies.

Caffeine↗
PubMed1995

"Silent" patent ductus arteriosus and bronchopulmonary dysplasia in low birth weight infants.

We conducted a clinical study on the antecedents of bronchopulmonary dysplasia (BPD) in 290 premature RDS infants with < or = 1.75 kg birth weight (BW). They were enrolled in a prospective trial of indomethacin treatment for "silent" patent ductus arteriosus (PDA), screened by 2-D echocardiographic and pulsed Doppler evaluation on the third day of life. The trial took place at the NICU of the Pediatric Department of Padua University between January 1987 and December 1991. Out of 290 infants screened, 96 had evidence of "silent" PDA (33%) and 77 responded to indomethacin treatment (80%). Comprehensively 79 (27%) developed BPD, and from these the incidence of BPD was statistically increased in infants with "silent" PDA, 47 out of 96 (49 +/- 9%), with respect to 32 out of 194 (16 +/- 3%) preterm infants without PDA. Statistical analysis showed that in preterm infants with "silent" PDA the development of BPD was correlated at 99% C.L. to their low BWs (mean BW = 1.13 kg): in fact the mean and the mode of BW distributions were statistically lower in the presence of BPD, 1.03 kg versus 1.24 kg, and 0.88 kg versus 1.65 kg respectively. Moreover, the preterm infants with "silent" PDA unresponsive to the first course of indomethacin and/or submitted later to surgical closure, presented a statistically lower BW with respect to the early responders, 1.06 kg versus 1.18 kg, and at the same time a statistically higher incidence of BPD (63 +/- 20% versus 43 +/- 9%). From these data we conclude that, although "silent", PDA increase per se the incidence of BPD, even if benefits from an early induced closure. Furthermore, a lower BW of infants affected by "silent" PDA represents a contributing factor to the development of BPD.

Bronchopulmonary Dysplasia↗
PubMed1994

Dicistronic targeting constructs: reporters and modifiers of mammalian gene expression.

To investigate the activity of candidate regulatory molecules in mammalian embryogenesis, we have developed a general strategy for modifying and reporting resident chromosomal gene expression. The picornaviral internal ribosome-entry site was incorporated into gene targeting constructs to provide cap-independent translation of a selectable marker from fusion transcripts generated following homologous recombination. These promoterless constructs were highly efficient and have been used both to inactivate the stem-cell-specific transcription factor Oct-4 and to introduce a quantitative regulatory modification into the gene for a stem-cell maintenance factor, differentiation-inhibiting activity. In addition, the inclusion of a beta-galactosidase reporter gene in the constructs enabled accurate and sensitive detection of cellular sites of transcription. This has allowed visualization of putative "stem-cell niches" in which sources of elevated expression of differentiation-inhibiting activity were localized to the differentiated cells surrounding colonies of stem cells.

Animals↗
PubMed1994

Ketotifen in the management of infants with bronchopulmonary dysplasia.

Ketotifen, a histamine (H1) antagonist, inhibits PAF-induced eosinophil accumulation and airway hyperreactivity. Bronchopulmonary dysplasia (BPD) is a complex disorder in which bronchial hyperreactivity is usually present. An open randomized trial was carried out with this agent in infants with chronic BPD who were followed up for 6 months. The efficacy of the drug was evaluated according to respiratory symptom and medication scores, in which numerical values were assigned to various other antiasthmatic agents used to control wheezing. No adverse clinical or biochemical sequelae were noted during treatment. The mean respiratory symptom and mean medication scores were significantly higher worse in the control group in comparison with the infants treated with ketotifen.

Bronchopulmonary Dysplasia↗