Study of developing tracheal cartilage under light microscope

Background: Airway formation is one of the earliest events in development of respiratory system. However, maturation of airway continues well in post-natal life. The trachea has framework of incomplete ring of hyaline cartilage united by fibrous tissue and smooth muscle through which air conduction takes place. The trachea-bronchial mucosa is target for host of airborne toxic agents; bacterial and viral agents, allergens, reactive gases, aerosols, and irritant particles. This fascinates many workers for detailed study of epithelium or lining air passage. Aims and Objectives: The present study was undertaken to document normal developmental microscopic structure of tracheal cartilage in fetuses of different age group (gestational ages between 12th and 40th weeks) and to compare the difference between different age groups. Materials and Methods: Tissues from trachea of various age group fetuses were collected, processed, and stained with H and E and Masson’s trichrome. Results: Development of tracheal cartilage was observed into three trimesters. The 2nd and 3rd trimesters were further divided in the early 2nd (13th–16th weeks), mid-2nd (17th–20th weeks), late 2nd (21st–24th weeks), early 3rd (25th–28th weeks), mid-3rd (29th–32nd weeks), and late 3rd (33rd–40th weeks) phases. Conclusion: Perichondrium of cartilage had shown well-marked outer fibrous layer with increased vascularity by late 2nd to early 3rd trimester. Well-marked inner cellular layer of perichondrium was noticed by 3rd trimester, while cartilage had shown active chondrocytes by late 2nd to early 3rd trimester. At the late 3rd trimester, typical hyaline cartilage had shown chondrocytes in cell nest surrounded by territorial matrix.

Binswanger and the carotid sinus (Historical Note) / Binswanger e o seio carotídeo (Nota Histórica)

The 'carotid sinus' is an arterial dilatation placed usually at the beginning of the internal carotid artery. The medial wall of this dilatation appears modified, with a reduction of the media, and an increase of the adventitia, besides containing nervous terminations, forming thus a sensorial structure. This dilatation was possibly first observed by John Bell (1808), and clearly described and named by Cruveilhier (1834). However, many authors credited the initial finding to Burns (1811), followed by a number of researchers, as Luschka (1862), Manson (1866), Meyer (1876), Schäfer (1878), most with a view related to aneurysm formation, but some seeing the formation as a normal trait. Finally, Binswanger (1879) reaffirmed that the dilatation meant a normal feature of the region, based on his own observations, and on the opinion of some forerunners. Besides, he was the first to classify this dilatation regarding the variability of its localization. The thinning of this region was initially identified by Meyer (1876) and detailed by Binswanger (1879), at bare eye visual inspection and on microscopic examination, observing there an important reduction of the width of the tunica media. Despite Meyer's effort, and mostly Binswanger's, the microscopic findings are incipient, what can be explained by the limitations of the histological techniques at the time. However, there is no doubt that Binswanger and his forerunners provided important information for the upcoming research, comprising the structure, innervation, and function of this formation.

O 'seio carotídeo' é uma dilatação arterial situada geralmente no início da artéria carótida interna. A parede medial dessa dilatação apresenta-se modificada, com redução da média e aumento da adventícia, além de conter terminações nervosas, constituindo assim uma estrutura sensorial. Essa dilatação foi possivelmente observada primeiro por John Bell (1808) e claramente descrita e denominada por Cruveilhier (1834). Entretanto, muitos autores creditam o achado inicial a Burns (1811), seguido por numerosos pesquisadores, como Luschka (1862), Manson (1866), Meyer (1876), Schäfer (1878), a maioria com olhar relacionada à formação de aneurisma, mas alguns vendo a formação como uma característica normal. Finalmente, Binswanger (1879) reafirmou que a dilatação representava um aspecto normal da região, baseado em observações próprias e na opinião de alguns de seus antecessores. Além disso, foi o primeiro a classificar essa dilatação quanto a variabilidade de sua localização. O adelgaçamento dessa região foi identificado inicialmente por Meyer (1876) e detalhado por Binswanger (1879), à inspeção visual a olho nu e ao exame microscópico, observando lá uma importante redução da espessura da túnica média. Apesar do esforço de Meyer e sobretudo de Binswanger, os achados microscópicos são incipientes, o que pode ser explicado pelas limitações das técnicas histológicas daquele tempo. Todavia, não há dúvida que Binswanger e seus precursores proveram importante informação para as pesquisas que se sucederam, compreendendo a estrutura, inervação e função dessa formação.

On the molecular drug design from viewpoint of precision medicine / 药学学报

Precision medicine (PM) involves the application of "omics" analysis and system biology to analyze the cause of disease at the molecular level for targeted treatments of individual patient. Based on the targeted treatment PM is closely related to pharmaceuticals, which, as a therapeutic means and supply front, mainly embody the two aspects:drug discovery/development, and clinical administration. Innovation of new molecular entities with safety and specific efficacy is the prerequisite and guarantee for the PM practice; on the other hand, the outcome and clues in clinical PM feedback to new drug research. PM and drug research/application are interdependent and promote each other. Aimed at precision medicine, drug discovery and development involve well-known contents:the discovery and validation of targets, the association between target functions and indications (proof of concept), lead discovery and optimization, the association between preclinical investigations and clinical trials, the lean of industrialization and pharmacoeconomics. At the molecular level the therapeutic efficacy originates from the interactive binding between specific atoms or groups of the drug molecule and the complementary atoms or groups of the macromolecular target in three-dimensional space. The strict arrangement of such critical atoms, groups, or fragments reflect specific features for a precise binding to the corresponding target. An alteration of amino acid residues in mutational targets leads to the change in conformation of the target protein, and an accurate structure of drug is necessary for binding to the mutant species and avoiding off-targeting effect. For the tailoring of clinical treatment to the individual patient design and development of various new molecular entities are critical for treatment choice according to the molecular features of biological markers of patients. This article provides some examples and methods of drug design and development in the new period.

Microscopic Characteristics of Lower Eyelid Retractors in Koreans

PURPOSE: To identify the microscopic characteristics of lower eyelid retractors in Korean individuals and to elucidate age-related changes in lower eyelid retractors. METHODS: Eighteen Korean lower eyelids from formalin-fixed cadavers were stained with Masson's trichrome. Specimens were divided into two groups based on age at death (group A, 65 years), and the microscopic findings were analyzed and compared by light microscopy. RESULTS: The capsulopalpebral fascia (CPF) had distinct junctions and no fusion with orbital septum in 14 eyelids (77.8%). The CPF was fused with the orbital septum in only two eyelids (11.1%). Although not significant, the inferior tarsal muscle was closer to the tarsus in group A (1.24 +/- 0.71 mm) than group B (2.14 +/- 1.18 mm, p = 0.07), and the tarsal height tended to be longer in group B (4.71 +/- 0.55 mm) than group A (4.16 +/- 1.01 mm, p = 0.20). Tarsal fatty infiltration was more evident in group B. CONCLUSIONS: The CPF was rarely fused with the orbital septum in our sample of Korean lower eyelids. Although we did not identify any remarkable age-related changes in lower eyelid structures, there was a tendency for the lower retractor to loosen from the tarsus and for increased fatty infiltration in the lower eyelids from elderly individuals.

Microscopic Characteristics of Lower Eyelid Retractors in Koreans

PURPOSE: To identify the microscopic characteristics of lower eyelid retractors in Korean individuals and to elucidate age-related changes in lower eyelid retractors. METHODS: Eighteen Korean lower eyelids from formalin-fixed cadavers were stained with Masson's trichrome. Specimens were divided into two groups based on age at death (group A, 65 years), and the microscopic findings were analyzed and compared by light microscopy. RESULTS: The capsulopalpebral fascia (CPF) had distinct junctions and no fusion with orbital septum in 14 eyelids (77.8%). The CPF was fused with the orbital septum in only two eyelids (11.1%). Although not significant, the inferior tarsal muscle was closer to the tarsus in group A (1.24 +/- 0.71 mm) than group B (2.14 +/- 1.18 mm, p = 0.07), and the tarsal height tended to be longer in group B (4.71 +/- 0.55 mm) than group A (4.16 +/- 1.01 mm, p = 0.20). Tarsal fatty infiltration was more evident in group B. CONCLUSIONS: The CPF was rarely fused with the orbital septum in our sample of Korean lower eyelids. Although we did not identify any remarkable age-related changes in lower eyelid structures, there was a tendency for the lower retractor to loosen from the tarsus and for increased fatty infiltration in the lower eyelids from elderly individuals.