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Biomedical subjects

G D'Onofrio

Publications and source records attributed to G D'Onofrio.

At least 19 recordsLinked to original sources
PubMed2005

[Postpartum hemorrhage].

Postpartum hemorrhage, frequently due to uterine atony, is an important cause of maternal death and morbidity. The knowledge of causes, of antenatal and intrapartum risk factors and of physiopathological changes in hemodynamics and coagulation during pregnancy are essential for the management of the condition. At the present time, many efforts are made to organize a multidisciplinary approach to this complication of delivery involving clinical and laboratory staffs, since the rapid correction of hypovolemia, the diagnosis and treatment of defective coagulation, the surgical and pharmacological control of bleeding are mandatory. Several medical options have been developed and the surgical management includes traditional and newer conservative procedures with variable success rates. The developments in the treatment of postpartum hemorrhage may reduce hysterectomy that is to be considered the last resort to resolve the hemorrhage in some cases. In the modern management of postpartum hemorrhage protocols and guidelines should be available in every delivery room.

Embolization, Therapeutic↗
PubMed2004

Effect of dexamethasone on tracheobronchial aspirate fluid cytology and pulmonary mechanics in preterm infants.

The changes induced on respiratory mechanics and on tracheobronchial aspirate fluid (TAF) cytology by dexamethasone courses started at two different postnatal ages in preterm infants at risk of chronic lung disease (CLD) were reported in this clinical trial designed in two phases. The first phase of the study included 20 neonates with birth weight < or = 1,250 g and gestational age < or = 32 weeks, who were oxygen and ventilator dependent on the 10th day of life. They were randomly assigned to the moderately early dexamethasone (MED) group or to the control group. The second phase of the study included 20 neonates with the same characteristics, oxygen and ventilator dependent on the 4th day of life, randomly assigned to the early dexamethasone (ED) group or to the control group. Both treated groups received dexamethasone intravenously for 7 days (0.5 mg/kg/day for the first 3 days, 0.25 mg/kg/day for the next 3 days, and 0.125 mg/kg/day for the last day of treatment). The control groups received no steroid treatment. A significantly lower absolute cell count and percentage of neutrophils (PMN) in the TAF and significantly higher dynamic lung compliance (Cdyn) values were observed in both the MED treated compared to the untreated infants and the ED treated infants compared to the control group. Moreover these changes were more precocious in the ED Group compared to the MED Group. Our study suggests that dexamethasone could be more efficacious in reducing effects of ventilator-induced lung injury in preterm infants at high risk of CLD when started earlier.

Age Factors↗
PubMed2003

Efficacy of granulocyte transfusions for neutropenia-related infections: retrospective analysis of predictive factors.

BACKGROUND: The transfusion of G-CSf-primed granulocytes (GTX) might represent an important treatment option for neutropenia-related infections unresponsive to conventional antimicrobial therapies and to recombinant hematopoietic growth factors. However, few studies to date have identified the factors that can predict clinical outcome and the patient populations who are likely to benefit most from GTX. The primary endpoint of the present retrospective study was to evaluate the efficacy of GTX in 22 patients with hematological malignancies who developed neutropenia-related bacterial and fungal infections that were unresponsive to appropriate antimicrobial therapies. METHODS: Peripheral blood granulocytes were collected by continuous-flow leukapheresis from HLA-identical siblings after priming with G-CSF. The response to GTX was classified as 'favorable' if clinical symptoms and signs of infection resolved or 'unfavorable' if clinical symptoms and signs of infection were unchanged or worsened. Control of infection at Day 30 after the enrollment in the GTX program was considered as the outcome variable in multiple regression analysis. RESULTS: Two patients died of infection before receiving the granulocyte concentrates. Bacterial infections (monomicrobial or mixed bacteremias) were documented in 11 patients, whereas fungal infections (fungemia or focal fungal infections) were diagnosed in seven patients. In two patients, no infecting agent could be isolated (clinical infection). Control of infection at Day 30 after the first GTX was achieved in 10 of 20 assemble patients. Overall, 54% of patients with bacterial infections had a favorable response, compared with 57% of patients with fungal infections. No differences in terms of survival were found when comparing patients with bacterial and those with fungal infections at a median follow-up 90 days from the first GTX. In univariate analysis, disease status before GTX, e.g., complete or partial remission, and spontaneous recovery of the neutrophil count were significantly associated with control of infection. when multivariate regression models were formed, the recovery 0.5 x 10 (9)/L PMN was the only parameter that significantly and independently correlated with a favorable response to GTX. DISCUSSION: GTX can be used to successfully treat bacterial as well as fungal infections in severely neutropenic patients when administered early after the onset of febrile neutropenia in patients with remission of the underlying disease and who are likely to recover marrow function.

Adult↗
PubMed2002

Phosphatidylserine exposure in platelet concentrates during the storage period: differences between the platelets collected with different cell separators.

BACKGROUND AND OBJECTIVES: Platelet alterations occur during the production and storage of platelet concentrates, the so called "storage lesion". We studied the platelet alterations during the storage period in apheresis concentrates, employing flow cytometry for phosphatidylserine (PS) detection on platelets during the five days of storage. MATERIAL AND METHODS: Twenty-seven single donor platelet concentrates harvested with the Cobe Trima, Baxter Amicus, or Haemonetics MCS+ were analyzed for PS exposure by flow cytometry on the day of production (day 1) and on days 3 and 5 of storage. Furthermore PS expression was analyzed in platelet donors' blood samples withdrawn before plateletpheresis. RESULTS: PS expression on platelets gave the following median values: in blood donors before apheresis it was 1.12% (0.13-1.78) in platelets concentrates on the first day (2 h after apheresis) 2.06% (0.66-15.2), the third day 6.57% (1.98-51.13) and the fifth day 23.04% (3.86-80.23). All differences between median values of PS expression in blood samples before apheresis, and platelets concentrates on days 1, 3 and 5 of storage, are statistically significant. The expression of PS in platelet concentrates was analyzed in relation to the blood cell separator used for the collection procedure and showed the following results: on day 1 the median values of PS in platelet concentrates collected with the three different blood cell separators, Trima, Cobe and MCS, did not show statistically significant differences. On day 3, the platelets concentrates collected with the Trima and with the MCS showed differences that were statistically significant. Those were respectively 10.59% (4.56-51.13) and 3.53% (1.98-12.61), p = 0.005. The PS expression in platelet concentrates collected with the Trima and MCS showed differences that are also statistically significant on day 5 at respectively 32.4% (9.61-80.23) and 8.57% (3.86-48.42), p = 0.005. CONCLUSIONS: PS exposure in platelet concentrates on days 3 and 5 rise to levels that could compromise the quality of the platelet units. Improvements in standardized platelet quality controls, and in platelet collection systems are required to reduce the storage lesions in platelets concentrates.

Adult↗
PubMed2002

Clinically significant autoimmune hemolytic anemia with a negative direct antiglobulin test by routine tube test and positive by column agglutination method.

In two to five percent of cases of autoimmune hemolytic anemia (AIHA),the patient's RBCs are negative in the direct antiglobulin test (DAT). We describe a patient with AIHA with a negative DAT when tested by the traditional tube test but with a strongly positive one when tested by column agglutination. When the DAT was repeated by tube test using 4 degrees Celsius saline washes, it became positive. This phenomenon has been observed when low-affinity antibodies are involved in AIHA. The patient's history and serologic findings are detailed in this report.

Journal Article↗
PubMed2001

Translational selection on codon usage in Xenopus laevis.

A correspondence analysis of codon usage in Xenopus laevis revealed that the first axis is strongly correlated with the base composition at third codon positions. The second axis discriminates between putatively highly expressed genes and the other coding sequences, with expression levels being confirmed by the analysis of Expressed sequence tag frequencies. The comparison of codon usage of the sequences displaying the extreme values on the second axis indicates that several codons are statistically more frequent among the highly expressed (mainly housekeeping) genes. Translational selection appears, therefore, to influence synonymous codon usage in Xenopus.

Amino Acids↗
PubMed2000

The compositional transition between the genomes of cold- and warm-blooded vertebrates: codon frequencies in orthologous genes.

The genomes of the ancestors of mammals and birds underwent a compositional change in which the gene-richest regions increased their GC levels. Here we investigated this compositional transition by analyzing the levels of G and C in third codon positions, as well as the codon frequencies of orthologous genes from human, chicken and Xenopus. The results may be summed up as follows: (i) GC-poor genes, that did not undergo the compositional transition, showed only minor differences in orthologous sets from Xenopus, human and chicken; this is remarkable in view of the very many nucleotide substitutions that occurred over the long evolutionary times separating these species; (ii) GC-rich genes, that underwent the compositional transition, showed large differences between Xenopus and warm-blooded vertebrates, but not between chicken and human. In other words, the independent changes that occurred in avian and mammalian genes, on the average, were the same.

Amino Acids↗
PubMed2000

Second codon positions of genes and the secondary structures of proteins. Relationships and implications for the origin of the genetic code.

The nucleotide frequencies in the second codon positions of genes are remarkably different for the coding regions that correspond to different secondary structures in the encoded proteins, namely, helix, beta-strand and aperiodic structures. Indeed, hydrophobic and hydrophilic amino acids are encoded by codons having U or A, respectively, in their second position. Moreover, the beta-strand structure is strongly hydrophobic, while aperiodic structures contain more hydrophilic amino acids. The relationship between nucleotide frequencies and protein secondary structures is associated not only with the physico-chemical properties of these structures but also with the organisation of the genetic code. In fact, this organisation seems to have evolved so as to preserve the secondary structures of proteins by preventing deleterious amino acid substitutions that could modify the physico-chemical properties required for an optimal structure.

Chemical Phenomena↗
PubMed2000

Clinical characteristics as predictors of recurrent alcohol-related seizures.

OBJECTIVE: To determine whether clinical data available in the emergency department can accurately predict a subset of patients at low risk of developing recurrent seizures following one or more initial alcohol-related seizures in the out-of-hospital arena. METHODS: This was a retrospective secondary analysis of data obtained from the placebo arms of two prospective, randomized trials of drug treatments for the prevention of recurrent alcohol-related seizures. Subjects with and without one or more recurrent alcohol-related seizures during the study period were compared according to the following characteristics: 1) age, 2) gender, 3) daily ethanol consumption, 4) years of ethanol abuse, 5) previous alcohol-related seizure, 6) previous seizure of other etiology, 7) temperature, 8) heart rate, 9) systolic blood pressure, 10) diastolic blood pressure, 11) respiratory rate, and 12) ethanol level. Data were analyzed with t-tests and chi-square where appropriate. RESULTS: One hundred five placebo-treated patients were analyzed and 31 (30%) developed recurrent alcohol-related seizures. None of the listed characteristics were statistically different between the two groups except for the initial ethanol level. Subjects with an ethanol level higher than 100 mg/dL were less likely (0%) to develop recurrent seizures than patients with a level equal to or below 100 mg/dL (36%) (p < 0.01). CONCLUSIONS: An initial ethanol level higher than 100 mg/dL was significantly associated with a low risk for recurrent alcohol-related seizures during the observation period. No other low-risk clinical characteristics could be identified.

Adult↗
PubMed2000

Women in academic emergency medicine.

OBJECTIVE: To evaluate the achievement of women in academic emergency medicine (EM) relative to men. METHODS: This study was a cross-sectional mail survey of all emergency physicians who were employed at three-fourths full-time equivalent or greater at the 105 EM residency programs in the United States from August 1997 to December 1997. The following information was obtained: demographics, training and practice issues, roles and responsibilities in academic EM, percentage of time spent per week in clinical practice, teaching, administrative and research activities, academic productivity, and funding. RESULTS: Of the 1,575 self-administered questionnaires distributed by the office of the chairs, 1,197 (76%) were returned. Two hundred seventy-four (23%) of the respondents were women, and 923 (77%) were men. There was a significant difference noted between men and women in all demographic categories. The numbers of respondents who were nonwhite were extremely small in the sample and, therefore, the authors are hesitant to draw any conclusions based on race/ethnicity. There was no difference in training in EM between men and women (82% vs 82%, p = 0.288), but a significantly higher proportion of male respondents were board-certified in EM (84% vs 76%, p < 0.002). Women in academic EM were less likely to hold major leadership positions, spent a greater percentage of time in clinical and teaching activities, published less in peer-reviewed journals, and were less likely to achieve senior academic rank in their medical schools. CONCLUSIONS: These findings mirror those of most medical specialties: academic achievement of women in academic EM lags behind that of men. The paucity of minority physicians in academic EM didn't permit analysis of their academic achievements.

Academic Medical Centers↗
PubMed1999

The correlation of protein hydropathy with the base composition of coding sequences.

The "universal correlation" (D'Onofrio, G., Bernardi, G., 1992. A universal compositional correlation among codon positions. Gene 110, 81-88.) that holds between and or ( values are the average values of the coding sequences of each genome analyzed) at both the inter- and intra-genomic level, was re-analyzed on a vastly larger dataset. The results showed a slight, but significant, difference in the vs. correlations exhibited by prokaryotes and eukaryotes. This finding prompted an analysis of the correlation between and the amino acid frequencies in the encoded proteins, which has shown that positive correlations exist between values of coding sequences and the hydropathy of the corresponding proteins. These correlations are due to the fact that hydrophobic and amphypathic amino acids increase, whereas hydrophilic amino acids decrease with increasing values. Hydropathy values of prokaryotic proteins are systematically higher than those of eukaryotes, but the slopes of the regression lines are identical. The lower hydrophobicity of eukaryotic proteins is due to differences in the amino acid composition. In particular, the twofold higher cysteine (and disulfide bond) level of eukaryotic proteins compared to prokaryotic proteins most probably compensates for their lower hydrophobicity. This supports the viewpoint that hydrophobicity plays a structural and functional role as far as protein stability is concerned.

Amino Acids↗
PubMed1999

Correlations of nucleotide substitution rates and base composition of mammalian coding sequences with protein structure.

We investigated the relationships between the nucleotide substitution rates and the predicted secondary structures in the three states representation (alpha-helix, beta-sheet, and coil). The analysis was carried out on 34 alignments, each of which comprised sequences belonging to at least four different mammalian orders. The rates of synonymous substitution were found to be significantly different in regions predicted to be alpha-helix, beta-sheet, or coil. Likewise, the nonsynonymous rates also differ, although expectedly at a lower extent, in the three types of secondary structure, suggesting that different selective constraints associated with the different structures are affecting in a similar way the synonymous and nonsynonymous rates. Moreover, the base composition of the third codon positions is different in coding sequence regions corresponding to different secondary structures of proteins.

Animals↗
PubMed1999

Different hydrophobicities of orthologous proteins from Xenopus and human.

A compositional transition was previously detected by comparing orthologous coding sequences from cold- and warm-blooded vertebrates (see Bernardi, G., Hughes, S., Mouchiroud, D., 1997. The major compositional transitions in the vertebrate genome. J. Mol. Evol. 44, S44-S51 for a review). The transition is characterized by higher GC levels (GC is the molar ratio of guanine+cytosine in DNA) and, especially, by higher GC3 levels (GC3 is the GC level of third codon positions) in coding sequences from warm-blooded vertebrates. This transition essentially affects GC-rich genes, although the nucleotide substitution rate is of the same order of magnitude in both GC-poor and GC-rich genes. In order to understand the evolutionary basis of the changes, we have compared the hydrophobicity of orthologous proteins from Xenopus and human. Although the differences are small in proteins encoded by coding sequences ranging from 0 to 65% in GC3, they are large in the proteins encoded by sequences characterized by GC3 values higher than 65%. The latter proteins are more hydrophobic in human than in Xenopus.

Amino Acid Sequence↗
PubMed1999

Evolutionary genomics of vertebrates and its implications.

The discovery that the vertebrate genomes of warm-blooded vertebrates are mosaics of isochores, long DNA segments homogeneous in base composition, yet belonging to families covering a broad spectrum of GC levels, has led to two major observations. The first is that gene density is strikingly non-uniform in the genome of all vertebrates, gene concentration increasing with increasing GC levels. (Although the genomes of cold-blooded vertebrates are characterized by smaller compositional heterogeneities than those of warm-blooded vertebrates and high GC levels are not attained, their gene distribution is basically similar to that of warm-blooded vertebrates.) The second observation is that the GC-richest and gene-richest isochores underwent a compositional transition (characterized by a strong increase in GC level) between cold- and warm-blooded vertebrates. Evidence to be discussed favors the idea that this compositional transition and the ensuing highly heterogeneous compositional pattern was due to, and was maintained by, natural selection.

Animals↗
PubMed1999

Lorazepam for the prevention of recurrent seizures related to alcohol.

BACKGROUND AND METHODS: Alcohol abuse is one of the most common causes of seizures in adults. In a randomized, double-blind study, we compared lorazepam with placebo for the prevention of recurrent seizures related to alcohol. Over a 21-month period, we studied consecutive patients with chronic alcohol abuse who were at least 21 years of age and who presented to the emergency departments of two hospitals in Boston after a witnessed, generalized seizure. The patients were randomly assigned to receive either 2 mg of lorazepam in 2 ml of normal saline or 4 ml of normal saline intravenously and then observed for six hours. The primary end point was the occurrence of a second seizure during the observation period. RESULTS: Of the 229 patients who were initially evaluated, 186 met the entry criteria. In the lorazepam group, 3 of 100 patients (3 percent) had a second seizure, as compared with 21 of 86 patients (24 percent) in the placebo group (odds ratio for seizure with the use of placebo, 10.4; 95 percent confidence interval, 3.6 to 30.2; P<0.001). Forty-two percent of the placebo group were admitted to the hospital, as compared with 29 percent of the lorazepam group (odds ratio for admission, 2.1; 95 percent confidence interval, 1.1 to 4.0; P=0.02). Seven patients in the placebo group and one in the lorazepam group were transported to an emergency department in Boston with a second seizure within 48 hours after hospital discharge. CONCLUSIONS: Treatment with intravenous lorazepam is associated with a significant reduction in the risk of recurrent seizures related to alcohol.

Adult↗
PubMed1999

Factor V Leiden and allogeneic bone marrow transplantation: chimerism as a confounding factor in genetic test interpretation.

Factor V Leiden is one of the most common genetic conditions predisposing to venous thrombosis. Diagnosis is currently made by plasma activity assay for activated protein C (APC) resistance or polymerase chain reaction (PCR)-based DNA assay. The occurrence of factor V Leiden is reported in a patient affected by acute myeloid leukaemia submitted to allogeneic bone marrow transplantation from an HLA identical sister. The donor was not affected by the factor V mutation. The patient did not develop thrombosis during induction and consolidation chemotherapy and the post-transplantation course was not complicated by thrombosis or veno-occlusive disease. At engraftment, PCR analysis showed the disappearance of factor V Leiden. Genetic tests on DNA after allogeneic marrow transplantation should be carefully interpreted as a result of donor chimerism.

Bone Marrow Transplantation↗
PubMed1999

Highly fluorescent reticulocyte count predicts haemopoietic recovery after immunosuppression for severe aplastic anaemia.

Highly fluorescent reticulocyte (HFR) counts are the most reliable and sensitive index of haemopoietic recovery after bone marrow or peripheral blood stem cell transplantation. We report the behaviour of HFRs during haemopoietic recovery in two patients who were affected by severe aplastic anaemia (SAA) and treated with horse antithymocyte globulin (ATG), cyclosporin A (CsA) and granulocyte colony-stimulating factor (G-CSF). A HFR value > 5% of the total reticulocyte count, a reticulocyte count > 30 x 10(9)/l, and a polymorphonuclear (PMN) count > 0.5 x 10(9)/l were found after 9 and 8, 20 and 46, and 16 and 22 days, respectively, after the end of ATG. HFR recovery to > 5% anticipated the rise of PMN > 0.5 x 10(9)/l by at least 7 and 14 days, respectively. Thus, HFR evaluation could be used as a reliable and early marker of response to immunosuppression in severe aplastic anaemia.

Adolescent↗