Structure-Activity Relationships and Therapeutic Applications of Retinoids in View of Potential Benefits from Drug Repurposing Process

Vitamin A, an essential micronutrient, is integral to various biological processes crucial for organismal development and maintenance. Dietary sources of vitamin A encompass preformed retinol, retinyl esters, and provitamin A carotenoids. Retinoic acid (RA), a key component, plays pivotal roles in vision, cell proliferation, apoptosis, immune function, and gene regulation. Drug repurposing, an effective strategy for identifying new therapeutic applications for existing drugs, has gained prominence in recent years. This review seeks to provide a comprehensive overview of the current research landscape surrounding retinoids and drug repurposing. The scope of this review encompasses a comprehensive examination of retinoids and their potential for repurposing in various therapeutic contexts. Despite their efficacy in treating dermatological conditions, concerns about toxicity persist, driving the search for safer and more potent retinoids. The molecular mechanisms underlying retinoid activity involve binding to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), leading to transcriptional regulation of target genes. This review seeks to shed light on the possibilities for repurposing retinoids to cover a wider spectrum of therapeutic uses by exploring recent scientific progress. It also aims to offer a more comprehensive understanding of the therapeutic prospects of retinoids and the broader impact of drug repositioning in contemporary medicine.

Immunohistochemical Analysis of the Ligamentum Mucosum is the Key to Understand its Clinical Usefulness

Ligamentum Mucosum(LM) is a ligamentous structure within the synovial layer of the knee joint capsule. For a long time LM was perceived as the vestigial remnant from the embryological development of the knee. Being treated as an irrelevant structure LM was often the first victim of shaver during arthroscopy. However, last years have shown increased interest in this structure due to its potentially significant clinical role. Our aim was to classify LM based on its morphological characteristics and examine its microanatomy using immunohistochemical analysis to reveal the potential clinical value for surgeons. We have examined sixteen fresh frozen lower limbs, 6 females (mean age 83.1 ± 3.4 years) and 10 males (mean age 84.2 ± 6.8 years). Classical histological H+E stain was routinely conducted. Subsequently, CD31 antibody (DAKO, Monoclonal Mouse Anti-Human, Clone JC70A) was used to mark vascular epithelium. Monoclonal Mouse Anti-Human Neurofilament Protein (NFP) antibody (DAKO, Clone 2F11) was used to expose the nerves. Moreover, we have conducted arthroscopic visualizing and suturing LM to the torn ACL during routinely performed arthroscopic suturing of the ACL. The dissection process has revealed that LM was present only in 75% of cases. Histological examination confirmed the presence of longitudinal collagen fiber bundles in all samples. Tiny nerves were confirmed by NFP, along the subsynovial layer in all samples. CD-31 immunostain revealed the presence of many vascular vessels along the entire ligament, especially well developed at its distal end. Our study has revealed that LM contains rich vascular network. Thus, it may be a donor for the revascularization process after ACL tear or reconstruction which may improve the recovery. Another great advantage of the LM is the presence of nerves along the subsynovial layer, hopefully they may serve as the source of reinnervation and hence better clinical outcome. Based on our results we believe that seemingly irrelevant LM may be very useful during surgical procedures in the knee region. Suturing LM to the ACL may not only prevent the infrapatellar fat pad from subluxation but also improve the blood flow and reinnervation of the injured ACL. Until now there are only a few studies examining microanatomy of the LM. This basic knowledge may serve as the foundation for surgical procedures. Hopefully our findings may be useful for surgeons while planning surgical procedures or clinicians while diagnosing patients who suffer anterior knee pain.

Microanatomical study of arachnoid granulations and meningeal architecture around Meckel's cave

Although the microanatomy of Meckel's cave (MC) has been well studied, there are still controversies regarding the meningeal architecture of the space. Moreover, there are only general mentions of the arachnoid granulations near MC in just a few sources. This study is aimed at determining the frequency, location, and anatomical variability of the main clusters of arachnoid granulations around MC. The dissection involved 26 isolated specimens of MC fixed in formalin (neutral buffered, 10%). This number included five freshly harvested specimens examined histologically. Additional paraffin block with MC horizontal section was taken from our neuroanatomical collection. Carefully selected anatomical and histological techniques were applied to assess the complex relationships between the arachnoid granulations and adjacent structures. Arachnoid granulations were found around MC in all specimens with different anatomical variations. The main clusters of arachnoid granulations were close to the trigeminal ganglion and its divisions. The dorsolateral wall of MC was a thick layer formed by interweaving bundles of collagen fibers arranged in various directions. The entire MC was surrounded by a dural sleeve (envelope). This sleeve separated MC from the lateral sellar compartment. At its anterior (rostral) end, it formed a cribriform area pierced by individual fascicles of the trigeminal nerve's primary divisions. The connective tissue forming the sleeve was not only continuous with the epineurium but also shifted to the perineuria surrounding individual nerve fascicles. The meningeal architecture around MC has a complex and multilayer arrangement with a collagenous sleeve closely related to the trigeminal ganglion. Arachnoid granulations are typically found around MC.

Gross and Micro-Anatomical Study of the Cavernous Segment of the Abducens Nerve and Its Relationships to Internal Carotid Plexus: Application to Skull Base Surgery

The present study aims to provide detailed observations on the cavernous segment of the abducens nerve (AN), emphasizing anatomical variations and the relationships between the nerve and the internal carotid plexus. A total of 60 sides underwent gross-anatomical study. Five specimens of the AN were stained using Sihler’s method. An additional five specimens were subjected to histological examination. Four types of AN course were observed: a single nerve along its entire course, duplication of the nerve, division into separate rootlets at the point of contact with the cavernous part of the internal carotid artery (ICA), and early-branching before entering the orbit. Due to the relationships between the ICA and internal carotid plexus, the cavernous segment of the AN can be subdivided into a carotid portion located at the point of contact with the posterior vertical segment of the cavernous ICA and a prefissural portion. The carotid portion of the cavernous AN segment is a place of angulation, where the nerve always directly adheres to the ICA. The prefissural portion of the AN, in turn, is the primary site of fiber exchange between the internal carotid plexus and either the AN or the lateral wall of the cavernous sinus.

The abducens nerve: its topography and anatomical variations in intracranial course with clinical commentary

BACKGROUND

The sixth cranial nerve (CN VI) - or the abducens nerve - in humans supplies only the lateral rectus muscle. Due to its topographic conditions, including angulations and fixation points along its course from the brainstem to the lateral rectus muscle, the CN VI is vulnerable to injury. Every case of CN VI palsy requires precise diagnostics, which is facilitated by an understanding of the anatomy. The present article's aims include a detailed study of the intracranial course of the CN VI, determination of occurrence of its particular anatomical variations, as well as presentation of some essential anatomical conditions which may conduce to CN VI palsy. Special emphasis was put on the correlation between craniometric measurements and a particular variation of the CN VI, which complements the data that can be found in literature.

MATERIALS AND METHODS

Twenty randomly selected specimens of cadaveric heads fixed in a 10% formalin solution were studied. The study used 40 specimens of the CN VI in order to examine its course variations within the section between the pontomedullary sulcus and the superior orbital fissure.

RESULTS

Detailed analysis of the CN VI topography and anatomy in its intracranial course revealed 3 anatomical variations of the nerve in the studied specimens. Variation I, found in 70% of cases, covers those cases in which the CN VI was found to be a single trunk. Those cases in which there was a branching of the CN VI exclusively inside the cavernous sinus were classified as variation II, occurring in 20% of cases. Cases of duplication of the CN VI were classified as variation III, found in 10% of the specimens. In 75% of cases of CN VI duplication one of the nerve trunks ran upwards from the petrosphenoidal ligament, outside Dorello's canal.

CONCLUSIONS

The CN VI throughout its intracranial course usually runs as a single trunk, however, common variations include also branching of the nerve in the cavernous sinus or duplication. Topographic relations of the CN VI with adjacent structures account for the risk of injuries which may be caused to the nerve as a result of a disease or surgical procedures.

Example of human individual identification from World War II gravesite

This paper presents the procedure elaborated by our team which was applied to the mode of identification of Red Army soldiers who were taken as prisoners by the German Army during World War II and deceased in captivity. In the course of our search the unmarked burial of ten Soviet prisoners of war was found. Historical, anthropological and genetic research conducted by us led to the personal identification of nine of them, including two by means of DNA analysis.

[Herpangina and erythema multiforme in a three-year boy]

The dentist can be confronted with a vesiculobullous lesion of the oral mucosa are a symptoms of herpes infection (herpangina) of throat. Human enteroviruses (HEVs) are a major cause of herpangina. Herpangina is an acute viral infection caused by certain viruses Coxsackie, is spread by respiratory droplets. The infection is mainly encountered in young children. Oral lesions rarely more than 7 days; treatment is symptomatic. Viral throat infections may accompany various skin rashes, such as erythema multiforme (which can also occur without any connection with a viral infection). At work was presented a case of 3-year-old boy with herpes symptoms of sore throat and mild forms of erythema multiforme.

Current management of congenital diaphragmatic hernia

The treatment of congenital diaphragmatic hernia (CDH) still represents a challenge, even for the specialised multidisciplinary teams in centres that provide treatment for CDH. Despite significant progress in the fields of pathophysiology, prenatal diagnosis, surgical techniques and intensive care, CDH is a disease still burdened with a high mortality. Due to the paucity of randomised studies, there are no standard guidelines for treatment. The present review looks at existing diagnostic and therapeutic principles based on the available literature.

Atypical abdominal lacerated wound--differentiation from an incised wound

In the Department of Forensic Medicine, Medical University in Lodz, there was performed an autopsy of a man with an extensive defect of the abdominal integument and perineum. The inspection of the body at the site it was found together with the deposition of the deceased man's concubine suggested the possibility of criminal degloving of the body using a sharp-edged tool with superimposed injuries inflicted by a dog. Autopsy findings combined with results of additional tests (microscopic examination of tissue sections, ethyl alcohol level determination) allowed for verification of the investigation hypothesis, exclusion of a criminal act and demonstrating dog-inflicted injuries as the cause of death.

[Multiple organ failure in a severely malnourished patient with chromosome aberration]

BACKGROUND

Pneumonia and malnutrition are two of the biggest killers in childhood, as defined by the World Health Organisation. Although common in the developing world, these conditions can also be observed in more advanced countries, as a result of negligence and lack of proper care in disabled children. We describe a case in which severe malnutrition resulted in multiple organ failure.

CASE REPORT

A 16-yr-old retarded girl with +14q chromosome aberration, was admitted to hospital because of severe anaemia and dyspnea. She was extremely malnourished. Her body weight was 32 kg with a height of 152 cm (BMI 13.9). Her Hb concentration was 1.12 mmol L(-1), Ht 7%, and RBC 0.93 T L(-1). RBC transfusion resulted in transfusion-related acute lung injury (TRALI) and multiple organ failure. She was treated with mechanical ventilation, inotropic support and parenteral nutrition, complicated by the refeeding syndrome and gastrointestinal haemorrhage. After recovery, a gastrostomy was performed, but due to gastric retention she required a laparotomy for adhesiolysis.The girl recovered and remains under home care.

DISCUSSION

In a case of a girl with retardation, multiple organ failure resulting from ten years of malnutrition was observed. She was especially difficult to treat because of a prolonged dysfunction of homeostasis, hypoproteinemia, hypophosphatemia and SIRS. Such patients require careful treatment in ICU settings.

[Identification of the site of skeletal remains from World War II]

The objective of the present article is to show the model of processing in case of discovering a WW II grave with skeletal remains and to discuss the possibilities of personal identification of the victims. In many similar cases, it is impossible to employ genetic methods because of lack of samples for comparison. The shown procedure proved to be efficient in spite of the fact that more than 60 years passed since the date of death.

[Dermatology of neonatal period--skin diseases undemanding of treatment]

The skin of newborns differs from adult skin in many aspects. It is in the developing age which makes it difficult to fulfill it's correct function. There are diseases which appear in the first month of the infants life and require treatment. Mild local therapy may be administered or extensive moisturization of skin changes. Common mild and easy passing skin syndromes are: vernix caseosa, cutis marmarotta, hyperplasia sebacea, milia, acne neonatorum, erythema toxicum neonatorum, transient neonatal pustular melanosis, and neonatal dermalia pustulosis.

[Anaphylactic shock leading to death in a young woman after oral administration of metamizole (Pyralginum-Polfa)--case report]

The purpose of the report was to describe a case of anaphylactic shock in a 22-year-old woman after administration of one tablet of metamizole (pyralginum-Polfa). The patient died, notwithstanding intensive treatment applied rapidly. The patient had been treated for bronchial asthma for a few years. There had been no side effects after repeated administration of metamizole before.

[Estimation of the printing preparations from the gingival pockets on the styrophlex straps with application of telemicroscopy]

Printing preparations from the gingival pockets coloured by means of Shorr's method and secretion of pocket fluid have been estimated in 33 patients before and after balneological treatment. A telemicroscope has been used to estimate the preparations. The preparations have been analyzed in the linear enlargement of 1500 times using a network consisting of 35 fields of the dimensions of 3 cm x 3 cm (20 microns x 20 microns in the preparation) marked on a monitor screen. It has been that the sample representative for the whole preparation is contained in the band lying along its centre long axis and it occupies 6.33% of the preparation surface. Correlation between the number of granulocytes and the number of fields with granulocytes and the height of the granulocytar infiltration and between the number of granulocytes in the printing preparation and the excretion of the pocket fluid has been demonstrated in patients before treatment.

[Influence of intraoral douches over the parodontium state and leucocytes activity in patients treated in the sanatorium of Swieradow Zdroj]

Using the following indices: gingival--GI, of gingivorrhoea--GBI, of parodontium--PI and of dental deposit--DI and the measure of the gingival pockets' depth and pocket fluid clinical estimation has been performed in 33 men with parodontium inflammation before and after the set 15 balneological procedures. Leucocytes and other morphotic elements in the pockets have been estimated on Styrophlex straps. Examinations of the peripheral blood have comprised NBT spontaneous test and stimulated by concanavalin, phagocytosis and chemotaxis. After treatment considerable clinical improvement, decrease in pocket fluid excretion reduction in the number of granulocytes and increase in epithelial cells' percentage in the gingival pockets as well as existence of disturbances in granulocytes function of the peripheral blood expressed by reduced chemotaxis and phagocytosis have been found.