School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland, 1142, New Zealand.
Published: February 2019
AI Article Synopsis
Article Abstract
Background: Collenchyma cells occur widely in eudicotyledons and provide mechanical support for growing organs. At maturity, the cells are elongated and have thick, non-lignified walls, which in celery contain cellulose and pectic polysaccharides, together with xyloglucans and heteroxylans and heteromannans. A previous study suggested that at least some of the collenchyma cell wall in celery is laid down after expansion has stopped and is thus secondary. In the present study, we re-examined this. We used chemical analysis and immunomicroscopy to determine changes in the polysaccharide compositions of these walls during development. Additionally, solid-state NMR spectroscopy was used to examine changes in polysaccharide mobilities during development.
Results: We showed the collenchyma walls are deposited only during cell expansion, i.e. they are primary walls. During cell-wall development, analytical and immunomicroscopy studies showed that within the pectic polysaccharides there were no overall changes in the proportions of homogalacturonans, but there was a decrease in their methyl esterification. There was also a decrease in the proportions of the (1 → 5)-α-L-arabinan and (1 → 4)-β-D-galactan side chains of rhamnogalacturonan I. The proportions of cellulose increased, and to a lesser extent those of xyloglucans and heteroxylans. Immunomicroscopy showed the homogalacturonans occurred throughout the walls and were most abundant in the middle lamellae and middle lamella junctions. Although the (1 → 4)-β-D-galactans occurred only in the rest of the walls, some of the (1 → 5)-α-L-arabinans also occurred in the middle lamellae and middle lamella junctions. During development, the location of the xyloglucans changed, being confined to the middle lamellae and middle lamella junctions early on, but later occurred throughout the walls. The location of the heteroxylans also changed, occurring mostly in the outer walls in young cells, but were more widely distributed in mature cells. Solid-state NMR spectroscopy showed that particularly cellulose, but also homogalacturonans, decreased in mobility during development.
Conclusions: Our studies showed that celery collenchyma cell walls are primary and that during their development the polysaccharides undergo dynamic changes. Changes in the mobilities of cellulose and homogalacturonans were consistent with the cell walls becoming stiffer as expansion ceases.
We describe a new species of the Cyrtodactylus irregularis complex based on six adult specimens from Phu Cat District, Binh Dinh Province, Vietnam. Cyrtodactylus binhdinhensis sp. nov.
Background: Reconstruction of the lids is a significant challenge for ocular plastic surgeons as it requires the greatest functional and cosmetic outcomes. This study aimed to share the experience of Tenzel rotational flap in upper and lower lid reconstruction of anterior lamella at a tertiary eye care hospital of Karachi, Pakistan.
Methods: 10 patients with upper and lower eyelid defects over a period of 6 months were a part of this prospective interventional clinical study.
Purpose: Anatomical associations between the frontal sinus and anterior skull base must be carefully understood in preoperative imaging to minimize surgical complications. This study aims to investigate the relationship between frontal sinus volume and lateral lamella angle.
Methods: 150 computed tomography scans of paranasal sinuses (300 sides) were retrospectively reviewed.
Lower eyelid function and appearance depend on the complex anatomic relationship between the soft tissue lamellae, supportive tarsoligamentous sling, and bone. Aging in the lower lid area may be caused by changes in the anterior lamella (skin and orbicularis oculi muscle), middle lamella (orbital septum and lower lid fat pads), posterior lamella (tarsus, lower eyelid retractors, and conjunctiva), tarsoligamentous sling (lateral retinaculum), or any combination of the previously described.
The study analyzed 87 patients who had malignant skin tumors on the lower eyelid between 2018 and 2022, focusing on their demographic details and tumor characteristics.
Basal cell carcinoma was the most common tumor type (86%), with a mean patient age of 73.5 years, and no significant difference was observed between male and female incidences (p=0.97).
For reconstructing eyelid defects, various strategies were used, including local flaps for small to medium defects and more advanced techniques for larger ones, with a specific focus on the anterior and posterior lamellae.
