Mandibulofacial dysostosis, microcephaly and thorax deformities in two brothers: a new recessive syndrome?

We report two brothers who presented with mandibulofacial dysostosis, growth retardation, microcephaly, thoracic deformities and conductive hearing loss along with asplenia in one case and aplasia of the gallbladder in the other. The pattern of malformations differs significantly from established syndromes with mandibulofacial dysostosis such as Nager syndrome or Genée-Wiedemann syndrome and also from cerebro-costo-mandibular syndrome. As chromosome analysis revealed normal male karyotypes, we consider this to be a distinct heritable syndrome that may be either autosomal recessive or X-chromosomal recessive.

Swing leg control in human running.

Humans can run within a wide range of speeds without thinking about stabilizing strategies. The leg properties seem to be adjusted automatically without need for sensory feedback. In this work, the dynamics of human running are represented by the planar spring mass model. Within this framework, for higher speeds, running patterns can be stable without control strategies. Here, potential strategies that provide stability over a broader range of running patterns are considered and these theoretical predictions are compared to human running data. Periodic running solutions are identified and analyzed with respect to their stability. The control strategies are assumed as linear adaptations of the leg parameters-leg angle, leg stiffness and leg length-during the swing phase. To evaluate the applied control strategies regarding their influence on landing behavior, two parameters are introduced: the velocity of the foot relative to the ground (ground speed matching) and the foot's angle of approach. The results show that periodic running solutions can be stabilized and that control strategies, which guarantee running stability, are redundant. For any swing leg kinematics (adaptation of the leg angle and the leg length), running stability can be achieved by adapting the leg stiffness in anticipation of the ground contact.

Upright human gait did not provide a major mechanical challenge for our ancestors.

Habitual bipedalism is considered as a major breakthrough in human evolution and is the defining feature of hominins. Upright posture is presumably less stable than quadrupedal posture, but when using external support, for example, toddlers assisted by their parents, postural stability becomes less critical. In this study, we show that humans seem to mimic such external support by creating a virtual pivot point (VPP) above their centre of mass. A highly reduced conceptual walking model based on this assumption reveals that such virtual support is sufficient for achieving and maintaining postural stability. The VPP is experimentally observed in walking humans and dogs and in running chickens, suggesting that it might be a convenient emergent behaviour of gait mechanics and not an intentional locomotion behaviour. Hence, it is likely that even the first hominis may have already applied the VPP, a mechanism that would have facilitated the development of habitual bipedalism.

The influence of gastroschisis on plasmatic coagulation, humoral immunity, and C-reactive protein.

Around the 30th week of gestation, patients with gastroschisis (GS) develop chronic inflammatory reactions on the serosal surface of the eventrated loops of intestine that lead to severe hyperfibrinogenemia and hypercoagulability, particularly if they are born prematurely. This result was found on comparison of coagulation studies from 12 patients with GS with those of 4 patients with omphalocele and of healthy premature babies and term infants. Furthermore, the patients with GS showed marked hypogammaglobulinemia, which might also be responsible for the increased numbers of infections complicating the course of this disease. The hypercoagulability increases the risk of thromboembolic complications and disseminated intravascular coagulation, particularly in combination with the surgical closure of the abdominal wall that is undertaken postnatally or with perinatal complications such as asphyxia. Prophylactic therapy with low-dose heparin is indicated.