Unusual Trajectory Research Articles

A transient CD15 immunoreactive sling in the developing mouse cerebellum

The distribution of the 3-fucosyl-N-acetyl-lactosamine (FAL, CD15) epitope in the developing mouse cerebellum was examined with the aid of immunohistochemistry of paraffin sections. CD15 immunoreactivity first appeared at E15 as a discrete bundle of processes lying beneath, and slightly within, the deeper layers of the external granular layer. By E17, when the cerebellar anlagen had completed their midline fusion, these processes could be traced from the germinal trigone at the lateral limits of the cerebellar anlage around the posterior cerebellar midline to the opposite germinal trigone. By P2, this sling was no longer apparent and CD15 immunoreactivity was confined to astrocytes in the cerebellar white matter, surrounding the deep cerebellar nuclei.The CD15 immunoreactive processes pursue an unusual trajectory through the developing cerebellum, unlike any other previously described axonal or glial process bundle in the cerebellum. From its trajectory and association with the ventricular surface it seems that this structure, which we have named the transverse cerebellar sling, is composed of glial processes, although it was not immunoreactive for S-100 or glial fibrillary acidic protein. The transient appearance of this sling encircling the posterior cerebellum is suggestive of a role in prenatal cerebellar morphogenesis.

MZ twinning: chance or determinism? An essay in nonlinear dynamics (chaos).

Classically, researchers considered monozygotic twinning (MZT) a random phenomenon. This paper tests the hypothesis with the aid of nonlinear dynamics techniques. The latter can tell true randomness from chance-like variation. Chaos, the endpoint of the threshold state of a nonlinear deterministic system, can mimic constrained randomness. From a practical standpoint, recognizing chaos in a time series data set means that the paradigmatic multifactorial model of causation is essentially ruled out. Specifically, time series of MZ, DZ, and single maternities were analysed. First, spectral analysis was used to uncover periodicities embedded in the series. Second, a singular value decomposition was undertaken to reduce noise from the series. Third, phase space attractors were drawn up that describe the 'asymptotic' trajectory of the system at any time. Results suggested that DZ, MZ, and single maternities shared a similar 32-year periodicity. Owing to two interwoven similar periodicities, the single-maternity cycle kinetics proved to be faster than that of DZ's. The MZ series was the only one to display secondary interacting harmonics, thus eliciting a rather unusual trajectory in the bidimensional phase space. The MZ time points were not spread in a haphazard fashion; on the contrary, a fine structure was present that did not reduce to a limit cycle such as the one characterizing the DZ- or the single-maternity trajectory. It was concluded that a complex nonlinear dynamic underlies MZ twinning. Therefore, calling for extrinsic causes to account for what appears to be random variation overtime would be pointless. MZ twinning should rather be traced to a limited number of intrinsic and deterministic interacting system components. The most likely candidates are presented and discussed.

New cases of orangoid hand: Carpopetal main lines of the palm

New cases of orangoid hand are described in two unrelated, normal, Spaniard women. This dermatoglyphic particularity is characterized by an unusual trajectory of the main lines of the palm, which tend to the proximal border of the palm, therefore a new terminology is proposed: ‘carpopetal main lines’.

Mediastinal traversing fatal oesophageal injury from an unusual trajectory: A case report and review of literature

Oesophageal perforation is a potentially lethal clinical condition. Penetrating thoracic oesophageal injury is associated with increased morbidity and mortality, especially if the interval between the injury and commencement of treatment is delayed beyond 24 h. We present a 20-year-old man with a 2 weeks history of mediastinal traversing thoracic oesophageal injury and secondary right empyema following assault. The injury was a stab using a long knife with an entry point at the upper left arm which took an unusual trajectory to traverse the left hemithorax and the mediastinum to penetrate the oesophagus in the right hemithorax. He was resuscitated and thoracotomy was done where the perforation was repaired and the lung decorticated, but he sustained cardiac arrest and could not be resuscitated. Delayed time interval between the time of oesophageal injury and the commencement of treatment is a key determinant of patients' outcome. Prompt diagnosis and institution of treatment significantly reduce the morbidity and mortality associated with oesophageal perforation.