Rediscovery and systematics of the enigmatic genus Helicostoa reveals a new species of sessile freshwater snail with remarkable sexual dimorphism.

Helicostoa sinensis E. Lamy, 1926 is a unique freshwater gastropod species with a sessile habit. This enigmatic species was first found cemented on river limestones from China about 120 years ago and described together with the genus. It was never collected again and has been considered monotypic. Here, we report the rediscovery of Helicostoa from several rivers in China, and describe a second species of this genus based on a comprehensive study. In addition to the unique sessile habit of both species, the new Helicostoa species presents one of the most remarkable cases of sexual dimorphism within molluscs. Only the adult female is sessile and the original aperture of the female is sealed by shell matter or rock, while an opening on the body whorl takes the function of the original aperture. The male is vagile, with a normal aperture. Our results confirm the recently suggested placement of Helicostoa within the family Bithyniidae. The sessility of Helicostoa species is considered as an adaption to the limestone habitat in large rivers. The extreme sexual dimorphism and secondary aperture of females are considered as adaptations to overcome the obstacles for mating and feeding that come with a sessile life style.

Can fractal dimensions objectivize gastropod shell morphometrics? A case study from Lake Lugu (SW China).

Morphometrics are fundamental for the analysis of size and shape in fossils, particularly because soft parts or DNA are rarely preserved and hard parts such as shells are commonly the only source of information. Geometric morphometrics, that is, landmark analysis, is well established for the description of shape but it exhibits a couple of shortcomings resulting from subjective choices during landmarking (number and position of landmarks) and from difficulties in resolving shape at the level of micro-sculpture.With the aid of high-resolution 3D scanning technology and analyses of fractal dimensions, we test whether such shortcomings of linear and landmark morphometrics can be overcome. As a model group, we selected a clade of modern viviparid gastropods from Lake Lugu, with shells that show a high degree of sculptural variation. Linear and landmark analyses were applied to the same shells in order to establish the fractal dimensions. The genetic diversity of the gastropod clade was assessed.The genetic results suggest that the gastropod clade represents a single species. The results of all morphometric methods applied are in line with the genetic results, which is that no specific morphotype could be delimited. Apart from this overall agreement, landmark and fractal dimension analyses do not correspond to each other but represent data sets with different information. Generally, the fractal dimension values quantify the roughness of the shell surface, the resolution of the 3D scans determining the level. In our approach, we captured the micro-sculpture but not the first-order sculptural elements, which explains that fractal dimension and landmark data are not in phase.We can show that analyzing fractal dimensions of gastropod shells opens a window to more detailed information that can be considered in evolutionary and ecological contexts. We propose that using low-resolution 3D scans may successfully substitute landmark analyses because it overcomes the subjective landmarking. Analyses of 3D scans with higher resolution than used in this study will provide surface roughness information at the mineralogical level. We suggest that fractal dimension analyses of a combination of differently resolved 3D models will significantly improve the quality of shell morphometrics.

[SLC2A2 gene analysis in three Chinese children with Fanconi-Bickel syndrome].

Fanconi-Bickel syndrome (FBS, OMIM 227810), a rare autosomal recessive disorder of carbohydrate metabolism, is caused by SLC2A2 (GLUT2) mutations. The study reported 3 cases of FBS who were confirmly diagnosed by SLC2A2 gene analysis. The three patients showed typical features like glycogen storage disease and proximal renal tubular nephropathy. Homozygous splice-site mutation IVS8+5G>C (c.1068+5 G>C) was found in patient A and homozygous nonsense mutation c.1194T>A (p.Tyr398X) in patient B. Patient C harboured a missense mutation c.380C>A (p.Ala127Asp) and a de novo insertion c.970dupT (p.324TyrfsX392) which was not inherited from her parents. Four mutations were identified in the 3 Chinese FBS patients. Except IVS8+5G>C mutation, the other 3 mutations were novel in Chinese population. To the best of our knowledge, patient C may be the first FBS case worldwide with de novo mutation.

[Effect of aggressive nutritional support on preterm infants during hospitalization].

OBJECTIVE: To explore the effect of aggressive nutritional support in early life on growth of preterm infants during hospitalization. METHOD: Two retrospective cohorts of preterm infants were compared; 81 infants of group A (born between January 1, 2005 and June 30, 2006) and 79 infants of group B (June 1, 2009 and November 30, 2010) with gestational age above 28 weeks and birth weight between 1000 g and 2000 g, transfered to NICU of PUMCH within 12 hours after birth, hospitalized for > or = 2 weeks, who were free of major congenital anomalies and survived to discharge were recruited. The comparison of enteral and parenteral nutrition, growth rate, biochemical indices during hospitalization between these both groups were made. RESULT: Compared to group A, group B was given greater volume of amino acid infusion on the 3(rd) and 7(th) day of life [2.00 (2.00, 2.50) g/kg vs 1.50 (1.50, 2.00) g/kg, 3.00 (2.00, 3.00) g/kg vs 2.00 (1.80, 2.60) g/kg, all P < 0.001], and Consumed more milk and total energy intake on the 3rd day of life [9.41(2.66, 18.74) ml/kg vs 14.47 (4.23, 30.77) ml/kg, P < 0.05, (64.87 ± 16.04) kcal/kg vs (55.62 ± 17.68) kcal/kg, P = 0.001]. Total energy intakes after a week of life were similar between the two groups. More infants received human milk fortifier in group B (62.8% vs 14.3%, P = 0.001). After stratification according to weight, both very low birth weight infants and infants with birth weight between 1500 g and 2000 g in group B grew more rapidly (P < 0.001). The percentage of growth retardation was increased after hospitalization in group A (65.4% vs 40.7%, P < 0.05), there were no statistically significant differences in group B. The mean Z scores at birth were comparable. The mean Z scores by discharge were higher in group B (-1.24 vs -1.54, P < 0.05). Serum albumin, prealbumin and urea values were similar in both groups at birth, but higher in group B after two weeks of life (P < 0.001). Before discharge, Serum albumin, prealbumin, and urea values in group B was higher (P < 0.001). CONCLUSION: Improvements in nutritional practices in early life of preterm infants effectively enhanced the growth and improved the nutritional status of preterm infants during hospitalization.

[Clinical analysis of nosocomial infection in neonatal intensive care units].

OBJECTIVE: Nosocomial infections (NIs) have become a matter of major concern in neonatal intensive care units (NICU). The objectives of this study were to investigate the incidence of nosocomial infections of newborn infants in NICU and to explore the risk factors and strategies of infection control. METHODS: The study enrolled 638 hospitalized newborn infants from Apr 2003 to Dec 2004. The clinical data, such as the clinical manifestation, the condition of colonized bacteria, were collected and analyzed by using SPSS software. RESULT: There were 88 times of nosocomial infections in 74 newborn infants. The overall incidence of nosocomial infections was 11.6%. The mean duration from admission to first episode of NI was 7.98 +/- 4.58 days. The incidence density was 14.9 per 1000 NICU patient-days. Catheter-correlated hematogenous infection rate was 18 per 1000 umbilical or central line-days; the ventilator-associated nosocomial pneumonia rate was 63.3 per 1000 ventilator days. The smaller the gestational age and the lower the birth weight, the higher the incidences of nosocomial infection. The duration of hospitalization was longer in these infected infants than those non-infected infants. Univariate analysis indicated that gestational age < or = 32 W, the parenteral nutrition, birth weight < or = 1500 g and mechanical ventilation, apnea, small for gestational age infant, central venous catheter (P < 0.05) were risk factors for NIs. Multivariate analysis identified 3 independent risk factions: the parenteral nutrition ([OR] = 7.185 [95% CI, 3.399 - 15.188]), birth weight < or = 1500 g ([OR] = 3.310 [95% CI, 1.100 - 9.963]) and mechanical ventilation ([OR] = 2.527 [95% CI, 1.092 - 5.850]). The most common infection was pneumonia (45.4%). The mortality rate of nosocomial infections was 4.1%. Bacterial surveillance was examined by nasopharyngeal and rectal swab culture immediately on hospital admission and then once a week. The incidence rate of NIs was 24.8% in patients whose nasopharyngeal and rectal swab culture indicated bacterial colonization, and 1.9% in patients without bacterial colonization (chi(2) = 79.7, P < 0.001). CONCLUSION: It is important to identify the high risk factors for nosocomial infections in newborn infants in NICU. Reducing the duration of the parenteral nutrition and the virulence manipulation as far as possible and getting the message of individual bacterial colonization in NICU may be conducive to decrease of the incidence of nosocomial infections and provide reference for rational clinical drug administration.