The loss of ions from Venus through the plasma wake.

Venus, unlike Earth, is an extremely dry planet although both began with similar masses, distances from the Sun, and presumably water inventories. The high deuterium-to-hydrogen ratio in the venusian atmosphere relative to Earth's also indicates that the atmosphere has undergone significantly different evolution over the age of the Solar System. Present-day thermal escape is low for all atmospheric species. However, hydrogen can escape by means of collisions with hot atoms from ionospheric photochemistry, and although the bulk of O and O2 are gravitationally bound, heavy ions have been observed to escape through interaction with the solar wind. Nevertheless, their relative rates of escape, spatial distribution, and composition could not be determined from these previous measurements. Here we report Venus Express measurements showing that the dominant escaping ions are O+, He+ and H+. The escaping ions leave Venus through the plasma sheet (a central portion of the plasma wake) and in a boundary layer of the induced magnetosphere. The escape rate ratios are Q(H+)/Q(O+) = 1.9; Q(He+)/Q(O+) = 0.07. The first of these implies that the escape of H+ and O+, together with the estimated escape of neutral hydrogen and oxygen, currently takes place near the stoichometric ratio corresponding to water.

SERENA: Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo.

The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase.

Four new cases of inverted terminal duplication: a modified hypothesis of mechanism of origin.

We present 4 recently diagnosed cases of inverted tandem duplication with involvement of the respective terminal band. Based on these 4 cases and review of the literature, the term "inverted terminal duplication" is proposed to designate specifically the type of inverted tandem duplication which involves the terminal band. A modification of the previous hypothesis of mechanism of origin is advanced. It is speculated further that a telomeric deletion of a meiotic chromosome followed by a U-type reunion of the chromatids, considered to be the first steps of the proposed mechanism of origin, may not be a rare gonadal event.

Confirmation of centromeric fusion in 7p/1q translocation associated with myelodysplastic syndrome.

Fluorescence in situ hybridization (FISH) using chromosome 1- and chromosome 7-specific centromeric alpha-satellite probes was performed on the bone marrow (BM) cells of a patient with myelodysplastic syndrome (MDS) who had been treated for lymphoma and whose BM karyotype was initially considered to be 46,XY,-7,+der(1)t(1;7)(p11;p11). FISH results suggested the presence of both chromosome 1 and chromosome 7 centromeres in the rearranged chromosome. Thus, the correct karyotype should be written as 46,XY,-7,+der(1;7)(q10;p10).

Supernumerary isochromosome 4p in ANLL-M4 myelomonocytic type is associated with favorable prognosis.

A case of an acute non-lymphocytic leukemia of M4 type with a supernumerary isochromosome (4p) in 100% of the initial bone marrow metaphase cells is reported. The origin of the extra chromosome is verified by the fluorescence in situ hybridization technique using a whole chromosome 4 painting probe. A possible favorable prognosis of the ANLL-M4 case showing a supernumerary isochromosome (4p) is cautiously emphasized.

The ABL/BCR fusion gene on chromosome 9 in Ph-negative chronic myelogenous leukemia: a case for vigilance in fluorescence in situ hybridization interpretation.

We report cytogenetic, fluorescence in situ hybridization (FISH), and molecular analysis in a case of Ph-negative chronic myelogenous leukemia patient with ABL/BCR fusion gene on chromosome 9 and a disparate FISH signal pattern using two commercially available bcr/abl probes (Vysis, Inc. and Oncor, Inc.). Cytogenetic analysis revealed a 46,XX normal female karyotype. FISH studies using Vysis LSI bcr/abl probe in interphase cells demonstrated a BCR/ABL fusion pattern, similar to that of m-BCR/ABL fusion found in acute lymphoblastic leukemia. However, examination of metaphases revealed the ABL/BCR fusion signal on one of the chromosomes 9, an ABL signal on the other chromosome 9, and two BCR signals of different sizes on each of the chromosomes 22. Subsequently, a FISH study with the Oncor major (M)-bcr/abl translocation probe confirmed the ABL/BCR fusion signal on chromosome 9 in addition to an ABL signal and a BCR signal located on chromosomes 9 and 22, respectively. Molecular studies (RT-PCR) revealed a rearrangement of the M-BCR region and expression of a chimeric bcr/abl mRNA of b3a2 configuration. This case suggests that it is imperative to have a full understanding of both the capabilities and the limitations of bcr/abl translocation probes and that FISH interphase signals should be confirmed on metaphase spreads for accurate diagnosis.

Ocular findings in partial trisomy 10q syndrome.

We examined three siblings with partial trisomy 10q born to a mother carrying a balanced translocation between chromosomes 4 and 10. Our patients had many of the phenotypic abnormalities characteristic of this syndrome, and their chromosomal abnormality was confirmed by karyotypes of peripheral blood lymphocytes. Two ophthalmoscopic abnormalities not previously reported in this syndrome were noted in our patients. One child had bilateral enlarged, gray optic disks with elevated, blurred margins and distended retinal vessels. Another child had bilateral punctate yellow deposits scattered around the macula and optic disk.

Trisomy 22 mosaicism with normal blood chromosomes. Case report with literature review.

A female infant with growth failure, microcephaly, hypertelorism, epicanthal folds, preauricular pit, congenital heart defect, hypotonia, and delayed development is reported. Trisomy 22 mosaicism (46,XX/47,XX,+22) was found in cultured skin fibroblasts but not in blood lymphocytes. Trisomy restricted to skin fibroblasts is uncommon.

The magnetic memory of Titan's ionized atmosphere.

After 3 years and 31 close flybys of Titan by the Cassini Orbiter, Titan was finally observed in the shocked solar wind, outside of Saturn's magnetosphere. These observations revealed that Titan's flow-induced magnetosphere was populated by "fossil" fields originating from Saturn, to which the satellite was exposed before its excursion through the magnetopause. In addition, strong magnetic shear observed at the edge of Titan's induced magnetosphere suggests that reconnection may have been involved in the replacement of the fossil fields by the interplanetary magnetic field.

Composition and dynamics of plasma in Saturn's magnetosphere.

During Cassini's initial orbit, we observed a dynamic magnetosphere composed primarily of a complex mixture of water-derived atomic and molecular ions. We have identified four distinct regions characterized by differences in both bulk plasma properties and ion composition. Protons are the dominant species outside about 9 RS (where RS is the radial distance from the center of Saturn), whereas inside, the plasma consists primarily of a corotating comet-like mix of water-derived ions with approximately 3% N+. Over the A and B rings, we found an ionosphere in which O2+ and O+ are dominant, which suggests the possible existence of a layer of O2 gas similar to the atmospheres of Europa and Ganymede.

De novo concurrent 5p deletion and distal 17q duplication identified by fluorescence in situ hybridization (FISH).

A de novo case of unbalanced 5p/17q translocation showing a concurrent 5p deletion and distal 17q duplication has initially eluded a definitive cytogenetic identification based on chromosome banding patterns and clinical features. But it is subsequently unequivocally identified by fluorescence in situ hybridization technique using various whole chromosome painting probes.

Evidence of chromosome 9 origin of the euchromatic variant band within 9qh.

Fluorescence in-situ hybridization studies using a whole chromosome 9 painting probe were performed on three individuals from two different families, who carry a chromosome 9 variant with an extra band within the elongated 9qh region. The results confirm the euchromatic nature of the extra band, and provide evidence that it is of chromosome 9 origin. This variant band, which may not be very rare, thus possibly results from a duplication of a segment of 9qh plus band p12 or part of band q21.

Mother-baby psychiatric units in Australia - the Victorian experience.

This article reviews the women admitted to Mother Baby Psychiatric Units in 2002, in the State of Victoria, Australia, looking at characteristics of postpartum disorders with respect to admission and outcome in a region with a high number of mother-baby unit beds relative to other Australian regions and other cities. Differences among units are noted, including the differential impact of whether the unit is associated with a psychiatric service or an obstetric service. This includes length of stay and referral patterns. Details of diagnosis, admission and outcome are compared to similar admissions in the United Kingdom, with similar factors predictive of poor outcome, defined as separation from the infant. Mother-Baby Units have an important potential role in improving these outcomes, with longer-term studies of these women needed.

45,X/46,XY/47,XY, +21 mosaicism in a hypogonadal phenotypic male.

A phenotypically normal male was found to have a chromosomal complement of 45,X/46,XY/47,XY, +21. This mosaic pattern has been reported only twice before. Although the patient had apparently fathered two children, he now has progressive impotence, absence of sperm in the seminal fluid, atrophic testes, almost complete absence of germ cells in testicular biopsies, high plasma LH and FSH, and a low normal testosterone. There were no physical characteristics of Turner's or Down's syndromes except for dermatoglyphic features commonly associated with the latter. These observations in this patients emphasise the value of chromosomal studies in multiple tissues in cases of mosaicism with atypical clinical features.