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Biomedical subjects

P Palumbo

Publications and source records attributed to P Palumbo.

At least 37 records · Page 2Linked to original sources
PubMed1999

Rapid telomere shortening in children.

Telomere shortening may reflect the total number of divisions experienced by a somatic cell and is associated with replicative senescence. We found that the average rate of telomere shortening in peripheral blood mononuclear cells (PBMCs) obtained longitudinally from nine different infants during the first 3 years of life (270 bp per year) is more than fourfold higher than in adults and does not correlate with telomerase activity. These results show that the rate of telomere loss changes during ontogeny, suggesting the existence of periods of accelerated cell division. Because human immunodeficiency virus (HIV) preferentially infects actively dividing cells, our observation suggesting accelerated cell division in children may provide an explanation for some of the distinctive pathogenic features of the HIV disease in infants, including higher viral loads and more rapid progression to acquired immunodeficiency syndrome (AIDS).

Adult↗
PubMed1999

Carbonaceous grain processing in space and in the laboratory.

Laboratory simulations of carbonaceous grain processing which occurs in space are fundamental to outline an evolutionary pathway for these particles. We consider the UV spectral changes induced in hydrogenated carbon grains by thermal annealing, UV irradiation and ion bombardment. The results give the opportunity to interpret observations in different space environments. In particular, modelling of the optical properties, based on a description of the electronic structure of carbons, indicates small hydrogenated amorphous carbon grains, with different degrees of UV irradiation, as the carrier of the ubiquitous UV interstellar extinction bump.

Carbon↗
PubMed1999

Distinct risk factors for intrauterine and intrapartum human immunodeficiency virus transmission and consequences for disease progression in infected children. Perinatal AIDS Collaborative Transmission Study.

Predictors and prognosis of intrauterine and intrapartum human immunodeficiency virus (HIV) transmission were investigated among 432 children of HIV-infected women in the Perinatal AIDS Collaborative Transmission Study. Timing of transmission was inferred from polymerase chain reaction or viral culture within 2 days of birth. Proportions of infections due to intrauterine transmission were similar among women using (29%) or not using zidovudine (30%). Preterm delivery was strongly associated with intrapartum transmission (relative risk, 3.7; 95% confidence interval [CI], 2.2-6.1), particularly among infants delivered longer after membrane rupture, but was not associated with intrauterine transmission. Progression to AIDS or death increased 2.5-fold (95% CI, 1.1-5.8) among intrauterine infected children, adjusting for preterm delivery, and maternal CD4 cell count. Early transmission appears unlikely to explain instances of zidovudine failure. Preterm infants may be more vulnerable to HIV acquisition at delivery, especially if membrane rupture is prolonged. Intrauterine infection does not appear to increase risk of preterm delivery.

Anti-HIV Agents↗
PubMed1999

A polymorphism in the regulatory region of the CC-chemokine receptor 5 gene influences perinatal transmission of human immunodeficiency virus type 1 to African-American infants.

There are natural mutations in the coding and noncoding regions of the human immunodeficiency virus type 1 (HIV-1) CC-chemokine coreceptor 5 (CCR5) and in the related CCR2 protein (the CCR2-64I mutation). Individuals homozygous for the CCR5-Delta32 allele, which prevents CCR5 expression, strongly resist HIV-1 infection. Several genetic polymorphisms have been identified within the CCR5 5' regulatory region, some of which influence the rate of disease progression in adult AIDS study cohorts. We genotyped 1,442 infants (1,235 uninfected and 207 HIV-1 infected) for five CCR5 and CCR2 polymorphisms: CCR5-59353-T/C, CCR5-59356-C/T CCR5-59402-A/G, CCR5-Delta32, and CCR2-64I. The clinical significance of each genotype was assessed by measuring whether it influenced the rate of perinatal HIV-1 transmission among 667 AZT-untreated mother-infant pairs (554 uninfected and 113 HIV-1 infected). We found that the mutant CCR5-59356-T allele is relatively common in African-Americans (20.6% allele frequency among 552 infants) and rare in Caucasians and Hispanics (3.4 and 5.6% of 174 and 458 infants, respectively; P < 0.001). There were 38 infants homozygous for CCR5-59356-T, of whom 35 were African-Americans. Among the African-American infants in the AZT-untreated group, there was a highly significant increase in HIV-1 transmission to infants with two mutant CCR5-59356-T alleles (47.6% of 21), compared to those with no or one mutant allele (13.4 to 14.1% of 187 and 71, respectively; P < 0.001). The increased relative risk was 5.9 (95% confidence interval, 2.3 to 15.3; P < 0.001). The frequency of the CCR5-59356-T mutation varies between population groups in the United States, a low frequency occurring in Caucasians and a higher frequency occurring in African-Americans. Homozygosity for CCR5-59356-T is strongly associated with an increased rate of perinatal HIV-1 transmission.

5' Untranslated Regions↗
PubMed1998

Impact of zidovudine use on risk and risk factors for perinatal transmission of HIV. Perinatal AIDS Collaborative Transmission Studies.

OBJECTIVES: To evaluate the impact of perinatal zidovudine use on the risk of perinatal transmission of HIV and to determine risk factors for transmission among women using perinatal zidovudine. DESIGN: Prospective cohort study of 1533 children born to HIV-infected women between 1985 and 1995 in four US cities. METHODS: The association of potential risk factors with perinatal HIV transmission was assessed with univariate and multivariate statistics. RESULTS: The overall transmission risk was 18% [95% confidence interval (CI), 16-21]. Factors associated with transmission included membrane rupture > 4 h before delivery [relative risk (RR), 2.1; 95% CI, 1.6-2.7], gestational age < 37 weeks (RR, 1.8; 95% CI, 1.4-2.2), maternal CD4+ lymphocyte count < 500 x 10(6) cells/l (RR, 1.7; 95% CI, 1.3-2.2), birthweight < 2500 g (RR, 1.7; 95% CI, 1.3-2.1), and antenatal and neonatal zidovudine use (RR, 0.6; 95% CI, 0.4-0.9). For infants exposed to zidovudine antenatally and neonatally, the transmission risk was 13% overall but was significantly lower following shorter duration of membrane rupture (7%) and term delivery (9%). The transmission risk declined from 22% before 1992 to 11% in 1995 (P < 0.001) in association with increasing zidovudine use and changes in other risk factors. CONCLUSIONS: Perinatal HIV transmission risk has declined with increasing perinatal zidovudine use and changes in other factors. Further reduction in transmission for women taking zidovudine may be possible by reducing the incidence of other potentially modifiable risk factors, such as long duration of membrane rupture and prematurity.

Adult↗
PubMed1998

Thymic dysfunction and time of infection predict mortality in human immunodeficiency virus-infected infants. CDC Perinatal AIDS Collaborative Transmission Study Group.

The effect of human immunodeficiency virus (HIV)-induced thymic dysfunction (TD) on mortality was studied in 265 infected infants in the CDC Perinatal AIDS Collaborative Transmission Study. TD was defined as both CD4 and CD8 T cell counts below the 5th percentile of joint distribution for uninfected infants within 6 months of life. The 40 HIV-infected infants with TD (15%) had a significantly greater mortality than did the 225 children without TD (44% vs. 9% within 2 years). Infants with TD infected in utero had higher mortality than did those infected intrapartum (70% vs. 37% within 2 years), while no significant difference was noted between infants without TD with either mode of transmission. The TD profile was independent of plasma virus load. Virus-induced TD by particular HIV strains and the time of transmission are likely to explain the variation in pathogenesis and patterns of disease progression and suggest the need for early aggressive therapies for HIV-infected infants with TD.

CD4 Lymphocyte Count↗
PubMed1997

[Local anesthesia in the surgery of inguinal hernia. Technical notes].

Routine use of local anaesthesia associated with tension-free hernioplasty in surgical treatment of inguinal hernia allows an immediate patient walking and prompt discharge from the hospital unit: with this technique 89 cases in two years were operated. The anaesthesia-related discomforts and complications are minimal. The addition of an intravenous sedative (propofol) premis to extend this approach to anxious patients too.

Anesthesia, Local↗
PubMed1997

[Surgery of inguinal hernias in the geriatric patient].

The Authors report a series of 73 elderly patients undergone to Lichtenstein hernioplasty with local anaesthesia. Treatment of inguinal hernia in emergency involves a high mortality; on the contrary, the lack of complications and a very good patient compliance shows that elective repair of inguinal hernia should be preferred and performed in the elderly.

Aged↗
PubMed1996

Lack of increased risk for perinatal human immunodeficiency virus transmission to subsequent children born to infected women.

BACKGROUND: Little is known about whether a woman's risk of transmitting HIV perinatally increases over time and whether the infection outcome of a previous child affects the risk of transmitting HIV to subsequent children. METHODS: We analyzed data from 114 prospectively followed women who gave birth to at least 2 children after becoming infected with HIV to determine the risk for perinatal HIV transmission to these sibling pairs. RESULTS: The median interval between sibling births was 19 months. HIV infection occurred in 19 (17%) older siblings and 20 (18%) younger siblings (P = 0.87). Two (11%) of the 19 children with infected older siblings were infected compared with 18 (19%) of the 95 children with uninfected older siblings (P = 0.86). The risk for transmission to younger siblings was not associated with the interval between deliveries of the two siblings. CONCLUSIONS: These data do not demonstrate that an HIV-infected woman's risk of transmitting HIV perinatally increases with time, although the observed interpregnancy interval was relatively short. The risk for perinatal transmission does not appear to be affected by the infection outcome of previous children. These findings may be useful for counseling HIV-infected women about their risk of transmitting HIV perinatally.

Child↗
PubMed1996

Evaluation of a quality assurance program for quantitation of human immunodeficiency virus type 1 RNA in plasma by the AIDS Clinical Trials Group virology laboratories.

A number of quantitative assays have been developed by using amplification techniques to measure human immunodeficiency virus type 1 RNA in the plasma of infected individuals. The Virology Committee of the AIDS Clinical Trials Group in the Division of AIDS, National Institute of Allergy and Infectious Diseases, has established a quality assurance program (QAP) for quantitative assays of HIV-1 RNA levels in plasma. The primary objective of the QAP was to ascertain that a laboratory could maintain the precision required to have a 90% power to detect a fivefold difference in RNA copy number between two samples in the same batch. To achieve this goal, the QAP required an intra-assay standard deviation of no greater than 0.15 log10 RNA copies per ml. Panels for proficiency testing consisted of coded replicate samples and a common set of standards. To date, 41 laboratories have participated in the program and have used both commercial and in-house assays. We demonstrated that 65% of the laboratories were capable of attaining the necessary level of intra-assay precision. The fitted regressions indicated that the differences among laboratories that used the same kit were generally greater than the differences among population-average regressions for the kits themselves. The use of an external QAP and a common set of standards reduced differences both among laboratories that used the same kit and among laboratories that used different kits. Thus, use of a common set of standards across clinical trial protocols would allow for cross-protocol comparisons.

Clinical Protocols↗
PubMed1996

[Blunt trauma of the larynx: comparative assessment of computerized tomography, conventional radiology, and laryngoscopy].

We report on the retrospective analysis of a series of 11 patients with blunt laryngeal injuries examined with Computed Tomography (CT), conventional radiology and laryngoscopy, to compare the diagnostic yield of each technique. Conventional frontal and lateral radiographs showed subcutaneous emphysema in 5 patients, with soft tissue swelling in 4, and thus failed to assess the degree of damage adequately. Cross-section CT showed cartilaginous injuries in 5 patients and adjacent soft tissue changes in 9, thus allowing rapid and accurate assessment of airway damage even in emergency. Laryngoscopy showed laryngeal mucosal tears in 3 patients, with decreased motion of the left true vocal cord in one patient and of both true vocal cords in another, associated with the upward dislocation of arytenoid cartilage. Moreover, laryngoscopy showed a mucosal tear in the hypopharynx in one patient. Comparative CT and laryngoscopy assessment showed, in two cases, that CT can demonstrate even minimal peripharyngeal and perilaryngeal air images which are suggestive of posttraumatic mucosal tears. Thus, CT appears the most valuable diagnostic tool to study the injured larynx.

Adolescent↗
PubMed1995

PCR analysis of HIV-seronegative, heterosexual partners of HIV-infected individuals.

A cohort of human immunodeficiency virus (HIV)-discordant couples was established to evaluate risk factors associated with heterosexual viral transmission. Polymerase chain reaction (PCR) was utilized to document the HIV-uninfected status among members of discordant heterosexual couples and to rule out immunosilent infection. HIV DNA PCR specific for a gag gene region was performed on peripheral blood mononuclear cell samples from 203 HIV antibody-negative adults who have long-term heterosexual relationships with HIV-infected partners. The results were negative for 200 but consistently positive in three individuals. More extensive evaluation of these three individuals with an additional primer pair specific for the envelope gene, quantitative DNA PCR, multiple additional time points, and variable nucleotide tandem repeat analyses revealed specimen processing problems in two cases but an apparent true positive PCR assay in the third case. This subject remains antibody and PCR negative for a 32-month follow-up period. These results confirm previous studies that document a negligible incidence of occult HIV infection as delineated by PCR in antibody negative heterosexual partners of HIV-infected individuals. Specimen processing errors occur at a low rate (1% in this study) and require careful evaluation. The possibility of transient, aborted infection versus successful infection with a long immunosilent period was observed in a single individual. Definitive resolution of infection status will require long-term evaluation.

Adult↗
PubMed1994

Laboratory findings in HIV infection in infancy.

The incidence of heterosexual HIV transmission continues to increase, especially among women of childbearing age. This has obvious implications for the care of pregnant women and their children, which has become as much a social issue as a medical one. Progress in the development of assays for both HIV diagnosis and clinical evaluation has given us the tools with which to begin dealing with this epidemic. Problems intrinsic to neonatal diagnosis are currently being addressed. In the next few years, assays that achieve rapid diagnosis in infancy should be readily available at reasonable cost. The appropriate utilization of this technology is a matter of active debate.

AIDS Serodiagnosis↗
PubMed1993

[The guaiac test and colorectal pathology. Clinical evaluation].

The paper reports the results of a study carried out in 187 out-patients who were examined for various reasons. A guaiac test was performed in all patients and those with positive results were further examined using more complex methods. The results obtained showed that, due to its high levels of sensitivity and specificity, as well as its low cost, the "Hemoccult test" still represents the most suitable means for the mass-screening of non-selected populations.

Adult↗
PubMed1993

Enzyme immunoassay for detection of human immunodeficiency virus-specific immunoglobulin A antibodies.

Early diagnosis of human immunodeficiency virus (HIV) infection may be difficult in adults with acute or recent HIV infection and in infants with perinatally acquired HIV. Detection of HIV-specific immunoglobulin A (IgA) antibodies in infant serum by Western blot (immunoblot) has been suggested as a reliable method to identify HIV-infected infants, especially those over the age of 6 months, and as an adjunct to diagnosis of acute HIV infection in adults. We developed a simple enzyme immunoassay for detection of HIV-specific IgA, using standard commercially available reagents. Enzyme immunoassay was comparable to Western blot for detection of HIV-specific IgA in sera from adults (n = 216), older children (n = 49), and infants born to HIV-infected mothers (n = 65). Specificity was 100% and sensitivity ranged from 80 to 92%. IgA-enzyme immunoassay is a simple, highly sensitive method for detection of HIV-specific IgA antibodies and is easily adapted to the standard clinical laboratory.

Adolescent↗
PubMed1992

An unusual case of false-positive serology for the human immunodeficiency virus: report from the heterosexual HIV transmission study.

A man was found to have a repeatedly positive enzyme immunoassay (EIA) that was confirmed by a western blot with six positive bands. He was told that he was seropositive for the human immunodeficiency virus (HIV), but subsequent EIAs were negative and western blots were either negative or indeterminant. All other HIV-related studies were unrevealing, and no explanation for the false-positive result was found. We have not absolutely eliminated the possibility of mislabeled specimens, but we believe this to be unlikely. The possibility, albeit infrequent, of concomitant false-positive EIAs and western blots should be kept in mind when formulating public policy with regard to HIV testing.

AIDS Serodiagnosis↗