The Dallol Geothermal Area, Northern Afar (Ethiopia)-An Exceptional Planetary Field Analog on Earth

The Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperature_Dallol: 36-38°C) and most acidic natural systems (pH_Dallol ≈0) on Earth. Spectacular geomorphologies and mineral deposits produced by supersaturated hydrothermal waters and brines are the result of complex interactions between active and inactive hydrothermal alteration of the bedrock, sulfuric hot springs and pools, fumaroles and geysers, and recrystallization processes driven by hydrothermal waters, degassing, and rapid evaporation. The study of planetary field analog environments plays a crucial role in characterizing the physical and chemical boundaries within which life can exist on Earth and other planets. It is essential for the definition and assessment of the conditions of habitability on other planets, including the possibility for biosignature preservation and in situ testing of technologies for life detection. The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars. The work presented in this paper is an overview of the Dallol volcanic area and its hydrothermal field that integrates previous literature with observations and results obtained from field surveys and monitoring coupled with sample characterization. In so doing, we highlight its exceptional potential as a planetary field analog as well as a site for future astrobiological and exploration programs.

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.

Early prenatal diagnosis of concordant posterior urethral valves in male monochorionic twins

The association between monozygotic twins and posterior urethral valves (PUV) in postnatal life has been thoroughly described. In the fetus, the prenatal recognition of PUV is feasible. However, it has been repeatedly reported in singletons but never in monochorionic twins. We describe two cases of early prenatal diagnosis of concordant PUVs in monochorionic twins. In one of the sets, the expression of the disease was different for each twin.

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.

Split notochord syndrome variant: prenatal findings and neonatal management

Spilt notochord syndrome is an extremely rare form of spinal dysraphism characterized by a complete cleft of the spine and a persistent communication between endoderm and ectoderm. A variant of split notochord syndrome was diagnosed in a 25-week-old fetus showing a prolapsed congenital colostomy and a spinal cystic lesion. The final diagnosis included protruding colon segment, imperforate anus with a rectourethral fistula and lipomyelomeningocele. The ultrasound features of the condition and the post-natal management are discussed. The neonate was successfully treated with a posterior sagittal anorectoplasty, while the lipomyelomeningocele was resected at a later stage.

Prenatal diagnosis of hemifacial microsomia and ipsilateral cerebellar hypoplasia in a fetus with oculoauriculovertebral spectrum

Oculoauriculovertebral spectrum, or Goldenhar syndrome, is characterized by varying degrees of prevalently unilateral underdevelopment of craniofacial structures (orbit, ear, mandible) and spinal anomalies. We report the prenatal ultrasonographic diagnosis made at 24 weeks' gestation in a family with a negative history. The prenatal diagnosis was suspected due to the presence of marked hemifacial microsomia and moderate ipsilateral cerebellar hemisphere hypoplasia in the absence of facial clefting.

Genetic prenatal RET testing and pregnancy management of multiple endocrine neoplasia Type II A (MEN2A): a case report

Multiple endocrine neoplasia 2A (MEN 2A) is an inherited dominant syndrome characterised by medullary thyroid carcinoma, adrenal pheochromocytoma and hyperparathyroidism due to specific RET proto-oncogene mutations. Fertile MEN 2A women are at risk of complicated pregnancy because of unrecognised pheochromocytoma and transmission of RET mutation to the progeny. This condition may cause psychological distress in affected pregnant patients and their families. Here we describe the genetic prenatal testing, the pregnancy management and obstetric outcome in a MEN 2A patient with a right side adrenal hyperplasia and elevated calcitonin levels, a condition suspicious for possible recurrence of pheochromocytoma. We confirm that maternal or fetal complications are rare when MEN 2A diagnosis is made before pregnancy and an accurate monitoring is instituted. Furthermore, our results indicate that prenatal testing for RET mutations is highly recommended in making decisions and assuring parents on the lifelong risk of tumors. This will avoid the psychological distress that can further complicate the pregnancy of affected women.

Pena-Shokeir phenotype with variable onset in three consecutive pregnancies

The Pena-Shokeir phenotype represents an autosomal recessive syndrome characterized by neurogenic arthrogryposis, facial anomalies and pulmonary hypoplasia. Prenatal diagnosis of this disease has been reported prospectively and in cases with positive family history. We describe here a patient who has had three consecutive pregnancies affected by the Pena-Shokeir syndrome. In these pregnancies, the onset of the arthrogryposis varied between the 12th and the 18th week of gestation. Therefore, the possibility of a variable chronological development of the main diagnostic feature of the syndrome, arthrogryposis, has to be taken into proper consideration while counseling families with a positive history for the Pena-Shokeir phenotype.

The association between congenital heart disease and Down syndrome in prenatal life

OBJECTIVE

To assess the relationship between congenital heart disease (CHD) and Down syndrome (DS) in utero.

DESIGN

Retrospective case series.

SUBJECTS

Fifty-two fetuses with a cytogenetic diagnosis of DS managed at our Fetal Cardiology Unit in the study period. In particular, two populations of fetuses with DS were studied: a group of 41 DS fetuses referred to our unit for fetal echocardiography due to the chromosomal anomaly and a second group of 274 fetuses referred because of suspected CHD, 11 of which were found to have DS.

METHODS

All fetuses were submitted to detailed ultrasound evaluation of fetal anatomy. Associated extracardiac anomalies, and presence and type of CHD, were recorded for all fetuses. Karyotyping was obtained by means of cordocentesis or amniocentesis. Necropsy or neonatal echocardiograms were sought for confirmation of the prenatal diagnosis.

RESULTS

In the group of 41 fetuses with known DS, the incidence of CHD was 56% ([atrioventricular septal defect (AVSD) 44%, ventricular septal defect (VSD) 48%], the remainder having other heart defects). Conversely, considering the incidence of DS in fetuses with CHD, 43% of all AVSDs (53% of AVSD with normal visceral situs) were associated with DS, whereas none of the 39 cases of VSD was associated with trisomy 21. Ventricular septal defects were diagnosed only in fetuses referred to our center with a known diagnosis of aneuploidy.

CONCLUSIONS

We have confined that more than half of the fetuses with DS bear a CHD, which is an AVSD in 44% of cases. Conversely, 43% of fetuses with an AVSD have trisomy 21. For VSDS, the situation is controversial, due to the relatively low detection level of this heart defect at the routine mid-trimester obstetric scan.