Relaxometric investigations and MRI evaluation of a liposome-loaded pH-responsive gadolinium(III) complex

Accurate measurement of the tissue pH in vivo by MRI may be of clinical value for both diagnosis and selection/monitoring of therapy. To act as pH reporters, MRI contrast agents have to provide responsiveness to pH that does not require prior knowledge of the actual concentration of the contrast agent. This work deals with the use of a paramagnetic gadolinium(III) complex, loaded into liposomes, whose relaxometric properties are affected by the pH of the medium. In this system, the amphiphilic metal complex, which contains a moiety whose protonation changes the coordination properties of the metal chelate, experiences a different intraliposomial distribution depending on the pH conditions. The pH of the solution can be unambiguously identified by exploiting the peculiar characteristics of the resulting NMRD profiles, and a ratiometric pH-responsive method has been set up by comparing the relaxation enhancement at different magnetic field strengths.

Prenatal diagnosis of congenital rubella infection and ultrasonography: a preliminary study

AIM

The aim of this study was to analyze the role of ultrasonography in the prenatal diagnosis of women with confirmed rubella infection in pregnancy.

METHODS

We performed a retrospective, population-based study on 175 women referred to our Centre of Infectious Disease in Pregnancy of AOU Federico II for rubella infection, in the period between January 1999 and December 2009. In confirmed cases of infection we performed periodic ultrasonographic assessment of fetal anatomy looking for prenatal findings of rubeovirus infection. Neonatal outcomes were collected.

RESULTS

Among 175 women, 48 (27.4%) were confirmed cases, in 83 (47.4%) cases rubella infection remain suspected. The remaining 44 (25.1%) women were excluded to having rubella infection in pregnancy. No defined probable cases were found. Among children born to mother with confirmed rubella infection, 9 (18.7%) resulted infected by rubella virus. In particular 6 newborns (66% of the affected) were asymptomatic, two babies showed incomplete congenital rubella syndrome (CRS), due to the presence of deafness in the absence of other congenital abnormalities without showing any USG findings. Only one baby showed a complete CRS: USG prenatal rubella infection findings were IUGR, polydramnios, cardiomegaly, defects of atrial septum, hepatosplenomegaly, ascites, echogenic bowel, placentomegaly. USG specificity and sensitivity was 100% and 11% respectively.

CONCLUSION

USG has an important role in the detection rubella intrauterine infection in case of severe abnormalities. The obstetricians should understand the limitations of ultrasound in detection of deafness and minor abnormalities.

Prenatal diagnosis of β-thalassemia: nuchal translucency in affected fetuses

AIM

Thalassemia syndromes are a group of blood disorders inherited in autosomal recessive manner. Prenatal diagnosis of disease is based on invasive procedures. Fetuses affected by homozygous thalassemia are not reported to be anemic. We studied their nuchal translucency (NT) measurements to identify as an ultrasonographic marker of disease and highlight any correlations.

METHODS

Between April 2006 and July 2010 NT test was offered to women referred to our center for prenatal diagnosis of thalassemia. All the NT tests were performed in the time of chorionic villus sampling (CVS), according to the standards of the Fetal Medicine Foundation. Measurements of fetuses affected by homozygous thalassemia were compared with normal fetuses.

RESULTS

A total of 55 fetuses were recruited. Of these, 15 were confirmed to be affected by homozygous thalassemia and 40 resulted to be carriers of thalassemia trait. Neither abnormal karyotype or structural abnormalities were detected and all the NT measurement were normal. NT was not different between the affected and normal fetuses.

CONCLUSION

NT is not a marker of homozygous thalassemia in fetuses at risk. Invasive procedures remain the only available methods for diagnosis.

First-trimester ultrasound determination of chorionicity in twin pregnancy

OBJECTIVE

To determine the accuracy of ultrasound at 11-14 weeks' gestation in the diagnosis of chorionicity in twin pregnancy.

METHODS

This was a retrospective observational study of data obtained between 1999 and 2010. At the first-trimester routine ultrasound scan, chorionicity was assigned according to the number of placental masses and T or λ-signs for a single placental mass. Chorionicity was confirmed by histology or discordant sex at birth.

RESULTS

A total of 648 pregnancies were assigned chorionicity by first-trimester ultrasound during the study period. Chorionicity was ascertained in 613 cases, either by histology (n = 340) or discordant sex (n = 273). Chorionicity was correctly assigned by ultrasound at 11-14 weeks in 612 of 613 pregnancies (accuracy 99.8%). Sensitivity and specificity for determining monochorionicity were 100% and 99.8%, respectively.

CONCLUSIONS

First-trimester ultrasound can be used to determine chorionicity reliably by noting the number of placental masses and T or λ-signs. Determination of twin chorionicity is important and should be completed in the first trimester.

Uterine artery Doppler screening for pre-eclampsia: comparison of the lower, mean and higher first-trimester pulsatility indices

OBJECTIVES

A previous study suggested that the lower uterine artery pulsatility index (PI) is a better predictor of pre-eclampsia than is either the mean or higher indices. The aim of this study was to assess the relative value of these three indices for the prediction of pre-eclampsia in the first trimester of pregnancy.

METHODS

This was a prospective study of 6221 singleton pregnancies. Uterine artery PI was obtained at the time of the 11-14-week nuchal translucency scan and receiver-operating characteristics curves for the lower, mean and higher PI value of the two uterine arteries in the prediction of pre-eclampsia were calculated.

RESULTS

There were 178 cases of pre-eclampsia. The associations between uterine artery PI and pre-eclampsia were stronger for early (requiring delivery < 34 weeks' gestation) and preterm (requiring delivery < 37 weeks) pre-eclampsia compared to pre-eclampsia at any gestation. There was no significant difference in the strength of the association between lower, mean and higher PI for pre-eclampsia at any gestation.

CONCLUSIONS

First-trimester uterine artery PI is strongly associated with the development of early and preterm pre-eclampsia. Lower, mean and higher uterine artery PIs are comparable in screening for pre-eclampsia. Any differences that exist between the lower, mean and higher uterine artery indices are unlikely to have a significant impact on screening sensitivities.

Sensitivity of higher, lower and mean second-trimester uterine artery Doppler resistance indices in screening for pre-eclampsia

OBJECTIVES

First-trimester Doppler studies have reported that the lower uterine artery (UtA) resistance index (RI) is better for the prediction of pre-eclampsia (PE) than is either the mean or higher indices. The aim of this study was to determine if this relationship is true in the second trimester.

METHODS

This was a retrospective study of 24 859 singleton pregnancies. During the study period second-trimester UtA Doppler assessment was routinely available to all nulliparous women and to parous women at increased risk of PE. UtA-RI was obtained at the time of the anomaly scan. Receiver-operating characteristics curves for the lower, mean and higher UtA-RI for the prediction of PE were calculated.

RESULTS

There were 1037 cases of PE. There were significant associations between UtA-RI and PE, the association being stronger for early and preterm than late or term PE. There was no significant difference in the strength of the association between lower, mean and higher RI with PE at any gestation.

CONCLUSION

Performance of UtA-RI in predicting PE is no different for the lower, higher or mean RI of the two UtAs. The most likely explanation for the discrepancy with first-trimester studies is that the placental-side effect on Doppler indices may change with advancing gestational age and progressive trophoblast development and invasion.

Detecting treatment response in a model of human breast adenocarcinoma using hyperpolarised [1-13C]pyruvate and [1,4-13C2]fumarate

BACKGROUND

The recent introduction of a dynamic nuclear polarisation technique has permitted noninvasive imaging of tumour cell metabolism in vivo following intravenous administration of (13)C-labelled cell substrates.

METHODS

Changes in hyperpolarised [1-(13)C]pyruvate and [1,4-(13)C(2)]fumarate metabolism were evaluated in both MDA-MB-231 cells and in implanted MDA-MB-231 tumours following doxorubicin treatment.

RESULTS

Treatment of MDA-MB-231 cells resulted in the induction of apoptosis, which was accompanied by a decrease in hyperpolarised (13)C label flux between [1-(13)C]pyruvate and lactate, which was correlated with a decrease in the cellular NAD(H) coenzyme pool. There was also an increase in the rate of fumarate conversion to malate, which accompanied the onset of cellular necrosis. In vivo, the decrease in (13)C label exchange between pyruvate and lactate and the increased flux between fumarate and malate, following drug treatment, were shown to occur in the absence of any detectable change in tumour size.

CONCLUSION

We show here that the early responses of a human breast adenocarcinoma tumour model to drug treatment can be followed by administration of both hyperpolarised [1-(13)C]pyruvate and [1,4-(13)C(2)]fumarate. These techniques could be used, therefore, in the clinic to detect the early responses of breast tumours to treatment.

Prevalence and characteristics of symptomatic and asymptomatic tuboovarian masses in women with HIV: an ultrasonographic study

HIV-positive women with pelvic inflammatory disease have been reported to have an increased prevalence of tuboovarian masses (TOMs). The aim of this study was to assess the prevalence of asymptomatic ultrasonographic TOMs in women with HIV and to identify associated factors in order to formulate a selective ultrasonographic screening strategy. Two-hundred and four HIV outpatients underwent transvaginal ultrasonography. Eight (3.9%) had a diagnosis of TOM (5 were asymptomatic). Two profiles of patients at risk for TOM were identified who could be considered for selective screening strategies: the 'long-term infected' (age>35 years, diagnosis of HIV infection more than 5 years ago, HIV clinical category C, CD4 counts below 200/mm(3), >5 lifetime partners and on antiretroviral therapy) and the 'recently diagnosed with HIV' (African ethnicity, age 25-35, HIV diagnosis in the previous year, >5 lifetime partners, HIV clinical category C and not on antiretroviral therapy).

Fetal borderline cerebral ventriculomegaly: clinical significance and management

AIM

The aim of this study was to evaluate the clinical significance and the management of fetal borderline lateral cerebral ventriculomegaly.

METHODS

Fetuses with a sonographic diagnosis of lateral cerebral ventriculomegaly isolated or associated to other fetal malformations were followed monthly and a review of the English-language literature was made.

RESULTS

Of 86 fetuses analyzed, 30 suffered from hydrocephaly (monolateral, bilateral), 56 showed also several other malformations . Chromosomal aberrations is possible also in case of isolated hydrocephaly. Neurological sequelae, mostly a mild to moderate delay in cognitive and/or motor development, is present in 10% of the cases.

CONCLUSIONS

In most cases, isolated borderline lateral cerebral ventriculomegaly has no consequence. However, the risk of cerebral maldevelopment, delayed neurological development and, possibly, chromosomal aberrations is increased. The optimum management of these cases remains uncertain.

Prenatal diagnosis of placental chorioangioma: our experience

Placental chorioangioma is the most common benign tumor of placenta. The relationship of vascularized chorioangiomas to adverse pregnancy outcome is well recognized. We report 3 cases of placental chorioangioma. Hypervascularization of the lesions in all patients and the immune hydrops with adverse fetal outcome in 2 cases are the complications of our mini-series. Ultrasonography and Doppler ultrasonography findings were useful in establishing the prenatal diagnosis and the prognosis.

Successful ICSI in a case of severe asthenozoospermia due to 93% non-specific axonemal alterations and 90% abnormal or absent mitochondrial sheaths

The use of IVF and intracytoplasmic sperm injection (ICSI) to treat male infertility due to severe asthenozoospermia in cases of electron microscopically confirmed axonemal abnormalities has been reported. However, even with these sophisticated technologies, very few pregnancies and births have been achieved with ejaculated spermatozoa in infertility due to this condition. The existence of sperm-derived defects preclude normal embryo development, and another reason for low success rates may be that the most commonly used method for selecting viable spermatozoa for ICSI is sperm motility, which is absent in affected men. Consequently, the likelihood of selecting non-viable spermatozoa for ICSI is higher in these cases. This report describes a case of a pregnancy achieved by ICSI with ejaculated spermatozoa containing 93% non-specific axonemal alterations and 90% abnormal or absent mitochondrial sheaths. A total of 14 oocytes was obtained from the 31-year-old patient in her first IVF treatment cycle. Three of the 13 matured (metaphase II) oocytes were inseminated conventionally, and the other 10 metaphase II oocytes were submitted to ICSI. None of the oocytes inseminated conventionally were fertilized. Of the 10 oocytes submitted to ICSI, four zygotes and cleavage embryos resulted. Three embryos were transferred on day 3, and a successful pregnancy was achieved. One gestational sac, together with regular heart activity, was recorded by ultrasonography at 8 weeks of gestation. A pregnancy is currently ongoing.

Pregnancy following a difficult transfer: a case report

Traumatic embryo transfers impact negatively on pregnancy rates. This study reports a clinical pregnancy obtained by transferring a blastocyst developed from a 72-h embryo, which had been retained on the catheter in a difficult transfer. A total of five oocytes was obtained from the 32-year-old patient in her first IVF treatment. Only one zygote and cleavage embryo resulted. A traumatic and bloody transfer was performed on day 3. The unique embryo was retained on the catheter. The embryo was left in culture medium until the blastocyst stage was achieved. A second transfer was performed and a successful pregnancy was achieved after transferring this blastocyst. A healthy baby was born. The results of the present report suggest that in cases of difficult transfers, waiting for the blastocyst stage might allow a second, non-traumatic transfer to be performed without embryos and cervix under the effects of stress.

DNA polymerases II and V mediate respectively mutagenic (-2 frameshift) and error-free bypass of a single N-2-acetylaminofluorene adduct

The NarI sequence represents a strong mutation hot spot for -2 frameshift mutations induced by N-2-acetylaminofluorene (AAF), a strong chemical carcinogen. Only when bound to the third (underlined) guanine (5'-GGCGCC-->GGCC) can AAF trigger frameshift mutations, suggesting the involvement of a slipped replication intermediate with a two-nucleotide bulge. While base substitutions induced by UV light or abasic sites require DNA polymerase V (Pol V; umuDC), the AAF-induced -2 frameshift pathway requires DNA polymerase II, the polB gene product. Interestingly, error-free bypass of the G-AAF adduct requires Pol V. The genes encoding both Pol II and Pol V are induced by the SOS regulon, a co-ordinated cellular response to environmental stress. A given lesion, G-AAF, can thus be bypassed by two SOS-controlled DNA polymerases (II and V), generating mutagenic (-2 frameshifts) and error-free replication products respectively. Therefore both Pol II and Pol V can compete for the blocked replication intermediate in the vicinity of the lesion and engage in replication by transiently replacing the replicative DNA Pol III. Our data suggest that, in order to cope with the large diversity of existing DNA lesions, cells use a single or a combination of translesional DNA polymerases to achieve translesion synthesis.

All three SOS-inducible DNA polymerases (Pol II, Pol IV and Pol V) are involved in induced mutagenesis

Most organisms contain several members of a recently discovered class of DNA polymerases (umuC/dinB superfamily) potentially involved in replication of damaged DNA. In Escherichia coli, only Pol V (umuDC) was known to be essential for base substitution mutagenesis induced by UV light or abasic sites. Here we show that, depending upon the nature of the DNA damage and its sequence context, the two additional SOS-inducible DNA polymerases, Pol II (polB) and Pol IV (dinB), are also involved in error-free and mutagenic translesion synthesis (TLS). For example, bypass of N:-2-acetylaminofluorene (AAF) guanine adducts located within the NAR:I mutation hot spot requires Pol II for -2 frameshifts but Pol V for error-free TLS. On the other hand, error-free and -1 frameshift TLS at a benzo(a)pyrene adduct requires both Pol IV and Pol V. Therefore, in response to the vast diversity of existing DNA damage, the cell uses a pool of 'translesional' DNA polymerases in order to bypass the various DNA lesions.

A 12q13 translocation involving the HMGI-C gene in richter transformation of a chronic lymphocytic leukemia

We report a case of Richter transformation of a chronic lymphocytic leukemia with a 12q13 translocation involving the HMGI-C gene. Fluorescence in situ hybridization analysis with the use of two different cosmid pools spanning the entire HMGI-C region showed that the breakpoint on chromosome 12 was located in the HMGI-C gene, presumably within intron 3. In fact, the 3' region of HMGI-C had been translocated to a derivative chromosome 6. This translocation was not visible at the cytogenetic level. Immunohistochemical analysis performed on the bone marrow smear demonstrated the expression of the HMGI-C protein specifically in the blasts, suggesting that the aberrant expression of the HMGI-C gene might have an important role in the process of leukemogenesis.

Effects of organic acids on lipid synthesis and ecdysis in Triatoma infestans eggs

Medium chain fatty acids are known inhibitors of the activity of lipogenic enzymes at the transcriptional level. Mature Triatoma infestans eggs incorporate [14C]-acetate into phospholipid (PL), triacylglycerol (TG), and free fatty acid (FFA) fractions. In the presence of sodium octanoate (SO) or sodium phenylethylpropionate (PHEP), lipid synthesis is inhibited in a dose-dependent manner. When eggs are incubated in vivo with [14C]-acetate, the usual fatty acid products are largely palmitic and oleic acids. However, in the presence of SO (5-10 mM), the elongation of [14C]-acetate units is interrupted at [14C] eight total carbons. Eggs incubated in vivo with [14C]-SO, accumulate most of the label in the FFA fraction. SO (> 0.1 mM) but not sodium hexanoate (SH), inhibits the activity of microsomal and cytosolic fatty acid synthetases (FAS's), measured as [14C]-malonyl-CoA incorporation. PHEP (1 mM) and SO (10 mM) also produce major alterations in egg hatching and survival of the emerged insects, after a 1 h immersion bioassay.

Entomopathogenous fungi degrade epicuticular hydrocarbons of Triatoma infestans

Studies were undertaken to analyze the ability of entomopathogenous fungi to degrade insect hydrocarbons. Strains of Beauveria bassiana and Metarhizium anisopliae pathogenic to the blood-sucking bug Triatoma infestans were grown on hydrocarbon and non-hydrocarbon insect lipid extracts and on synthetic hydrocarbon-enriched media as the sole carbon source. Entomopathogenous fungi were shown to utilize hydrocarbons as the only carbon source for their growth. Insect-derived hydrocarbons served more efficiently as metabolic fuel rather than synthetic compounds of similar structure. [3H]n-Pentacosane, [11,12-3H]3,11-dimethylnonacosane, and [14C]n-hexadecane were catabolized into different amounts of polar lipids, free fatty acids, and acylglycerols. In experiments using the branched alkane, labeled hydrocarbons of different chain length than the precursor were also synthesized. Evidence of complete catabolism was obtained by a significant release of 14CO2 from [1-14C]n-hexadecane. 14CO2 production might be used as a simple method to compare hydrocarbon utilization by fungal strains. These data demonstrate that entomopathogenous fungi are able to transform a variety of hydrocarbon structures into different lipid products, part of which may be subsequently utilized for energy production and for the biosynthesis of cellular components. These data are the first evidence of hydrocarbon catabolism and synthesis in entomopathogenous fungi.