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Although it is currently believed that the vocal ligament of humans undergoes considerable development postnatally, there is no consensus as to the age at which it first emerges. In the newborn infant, the lamina propria has been described as containing a sparse collection of relatively unorganized fibres. In this study we obtained larynges from autopsy of human fetuses aged 7-9 months and used light and electron microscopy to study the collagenous and elastic system fibres in the lamina propria of the vocal fold. Collagen fibres were viewed using the Picrosirius polarization method and elastic system fibres were stained using Weigert's resorcin-fuchsin after oxidation with oxone. The histochemical and electron microscopic observations were consistent, showing collagen populations with an asymmetric distribution across different compartments of the lamina propria. In the central region, the collagen appeared as thin, weakly birefringent, greenish fibres when viewed using the Picrosirius polarization method, whereas the superficial and deep regions contained thick collagen fibres that displayed a strong red or yellow birefringence. These findings suggest that the thin fibres in the central region consist mainly of type III collagen, whereas type I collagen predominates in the superficial and deep regions, as has been reported in studies of adult vocal folds. Similarly, elastic system fibres showed a differential distribution throughout the lamina propria. Their distribution pattern was complementary to that of collagen fibres, with a much greater density of elastic fibres apparent in the central region than in the superficial and deep regions. This distribution of collagen and elastic fibres in the fetal vocal fold mirrors that classically described for the adult vocal ligament, suggesting that a vocal ligament has already begun to develop by the time of birth. The apparently high level of organization of connective tissue components in the newborn is in contrast to current hypotheses that argue that the mechanical stimuli of phonation are essential to the determination of the layered structure of the lamina propria and suggests that genetic factors may play a more significant role in the development of the vocal ligament than previously believed.

The cricoid lumen configuration was elliptic, and its mean area was smaller than that of available endotracheal tubes. This lumen area was most influenced by weight and height.

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-Background: Few studies investigated brain abnormalities in early onset schizophrenia. Objective: To assess computed tomography (CT) abnormalities in patients with childhood or adolescence onset schizophrenia. Method: CT scans of patients with childhood (6 to 11 years old) (N=6) or adolescence (12-17 years old) (N=9) schizophrenia were compared to normal controls. Patients were diagnosed based on the DSM-III-R criteria. Ventricular enlargement was measured by the Ventricle to Brain Ratio (VBR) and Cortical Atrophy (pre-frontal prominence) was measured by the Pre-Frontal Atrophy Index (PFAI).Results: There was a significant difference in VBR, but not in PFAI, between subjects and controls [8.26±2.79, and 5.71±3.26 (p=0.029)], and [2.72±1.77, and 3.21±1.53 (p=0.424)], respectively. There were no differences of VBR and PFAI between children and adolescents with schizophrenia. Conclusion: Compared to controls, patients with child or adolescent onset schizophrenia exhibit more pronounced ventricular enlargement. There were no differences regarding prefrontal atrophy.