Prolactin and Prolactin-inducible protein (PIP) in the pathogenesis of primary acquired nasolacrimal duct obstruction (PANDO)

Role of paranasal abnormalities and systemic inflammation on primary acquired nasolacrimal duct obstruction

BACKGROUND

To determine the paranasal changes and inflammatory markers that may cause primary acquired nasolacrimal duct obstruction (PANDO) and to determine their relationship with success rates on different types of surgeries.

MAIN BODY

We retrospectively reviewed the blood sample and computed tomography (CT) results on 92 patients who underwent dacryocystorhinostomy (DCR) surgery for PANDO and 82 healthy controls. Age, gender, paranasal abnormalities, hemogram values, International Normalized Ratio (INR) values, type of surgery, and recurrence rate were recorded; systemic Immune-inflammation Index (SII), neutrophil-to-lymphocyte ratio (NLR), monocytes-to- lymphocyte ratio (MLR) and platelet-to-lymphocyte ratio (PLR) were calculated in both groups. In the case group, total white blood cells, monocytes, and INR values were significantly lower (p < 0.05). Platelet, lymphocyte, neutrophil, PLR, MLR, NLR, and SII values did not differ significantly between the control and case groups (p > 0.05). There was no significant difference in the CT results between the groups (p > 0.05). No correlation was found between CT findings and inflammatory markers. Dacryocystitis (DC) was seen in 20% of patients and they were all in the case group. No correlation was found between recurrence rate and age, gender, type of surgery, CT findings, and blood results (p > 0.05). The recurrence rate was significantly higher in patients with bilateral PANDO and with DC (p < 0.05).

SHORT CONCLUSION

The incidence of PANDO may not be directly related to paranasal abnormalities and systemic inflammation. Low INR values may cause obstruction in the nasolacrimal duct. Age, gender, type of surgery, CT findings, and inflammation level do not affect the success of the surgery.

Two-electron oxidized polyphenol chemistry-inspired superhydrophilic drug-carrying coatings for the construction of multifunctional nasolacrimal duct stents

Nasolacrimal duct obstruction due to infection, inflammation, or excessive fibroblast proliferation may result in persistent tearing, intraocular inflammation, or even blindness. In this study, surface engineering techniques are applied to nasolacrimal duct stents for the first time. Based on the functioning of marine mussels, "one-pot" and "stepwise" methods were employed to construct a novel multifunctional superhydrophilic PDA/RAP coating using dopamine and rapamycin. Micron-sized rapamycin crystals combined with nano-sized polydopamine particles form a micro-nano topographical structure. Therefore, acting synergistically with in situ-generated hydrophilic groups (amino, carboxyl, and phenolic hydroxyl), they impart excellent and long-lasting superhydrophilicity to the nasolacrimal duct stent. The PDA/RAP coating effectively maintained the stability of the initial microenvironment during stent implantation by inhibiting the onset of acute inflammation and infection during the early stages of implantation. Meanwhile, the rapamycin crystals, supported by the superhydrophilic platform, exhibited a sustained-release capability that helped them to better exert their anti-inflammatory, antibacterial, and anti-fibroblast proliferative properties, ensuring conducive conditions for the rapid repair of nasolacrimal duct epithelial cells, verified by a series of experiments. In conclusion, the PDA/RAP hydrophilic coating has anti-inflammatory, antifibrotic, antibacterial, and antithrombotic properties, offering a new strategy to address restenosis following clinical nasolacrimal duct stent implantation.

Nasolacrimal Duct Coronary Stent Recanalization (NCR): First Cadaver Experience and Its Potential as an Alternative to DCR

PURPOSE

To investigate the feasibility of implanting a drug-eluting cobalt-chromium alloy coronary stent in the nasolacrimal ducts (NLDs) of human cadavers.

METHODS

The pilot study was carried out in 5 NLDs of 4 adult human cadavers. Sirolimus-eluting coronary stents of 2 mm in width and lengths of 8 and 12 mm, which were mounted on balloon catheters, were used. Following dilatation of the NLDs, the balloon catheters were introduced into the NLDs under direct endoscopy guidance. The stents were delivered following dilatation of the balloon to 12 ATMs and secured in a locked (spring out) position. The balloon is then deflated and securely extubated. The dacryoendoscopy confirmed the stent position. The lacrimal system was then dissected to assess several key parameters like the uniformity of the NLD expansion, anatomical interactions of the NLD mucosa with the stent rings and struts, integrity of the soft and bony NLD, stent movement on mechanical push and pull, and ease of manual removal.

RESULTS

The cobalt-chromium alloy coronary stents could be delivered with ease and secured in the cadaveric NLDs. Its position was confirmed by a dacryoendoscopy and later by the direct NLD dissection. The NLD was uniformly dilated 360° with a wide and uniform lumen. NLD mucosa was noted to be uniformly distributed in spaces between the stent rings without influencing the expanded lumen. Following the lacrimal sac's dissection, the NLD stent showed significant resistance to downward movement but could be easily retrieved with forceps. The 12-mm stents could reach the near total length of the NLD with good luminal expansion. The integrity of the bony and soft-tissue NLD was maintained. The learning curve is shallow if the surgeon is adept with the techniques of balloon dacryoplasty.

CONCLUSION

Drug-eluting cobalt-chromium alloy coronary stents can be precisely deployed and secured within the human NLDs. The study is the first of its kind to demonstrate the technique of NLD coronary stent recanalization in human cadavers. It is a step forward in the journey to evaluate their use in patients with primary acquired NLD obstructions and other NLD disorders.

Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO)

Primary acquired nasolacrimal duct obstruction, or PANDO, is a common adult lacrimal drainage disorder. The current treatment modality of dacryocystorhinostomy to bypass the obstructed nasolacrimal duct has excellent outcomes. However, the understanding of the disease etiopathogenesis needs to be revisited. There are not many studies that specifically assessed any hypothesis or ones that convincingly put forth the presumed or confirmed interpretations regarding the PANDO pathogenesis or the mechanisms or pathways involved therein. Histopathological evidence points to recurrent inflammation of the nasolacrimal duct, subsequent fibrosis, and the resultant obstruction. The disease etiopathogenesis is considered multifactorial. Several implicated suspects include anatomical narrowing of the bony nasolacrimal duct, vascular factors, local hormonal imbalance, microbial influence, nasal abnormalities, autonomic dysregulation, surfactants, lysosomal dysfunction, gastroesophageal reflux, tear proteins, and deranged local host defenses. The present work reviewed the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO) to gain insights into the present state of the understanding and the high-value translational implications of precisely decoding the disease etiology.

Microbial distributions in the conjunctiva and lacrimal sacs of patients with chronic dacryocystitis in a tertiary hospital

BACKGROUND

The aim was to clarify the distributions of bacteria in the conjunctival sac and lacrimal sac in patients with chronic dacryocystitis.

METHODS

In total, 297 (322 eyes) chronic dacryocystitis patients who underwent nasal endoscopic dacryocystorhinostomy (EN-DCR) were included. Conjunctival sac secretions from the affected eye were collected preoperatively, and lacrimal sac retention fluid from the affected side in the same patient was collected intraoperatively. Bacterial culture and drug sensitivity testing were performed to determine bacterial distributions.

RESULTS

In total, 127 bacterial isolates (49 species) were detected in 123 eyes in the conjunctival group, with a positivity rate of 38.2% (123/322); 85 bacterial isolates (30 species) were detected in 85 eyes in the lacrimal sac group, with a positivity rate of 26.4% (85/322). The positivity rates were significantly different (P = 0.001) between two groups. The gram-negative bacilli proportion in the lacrimal sac group (36/85, 42.4%) was significantly higher than that in the conjunctival sac group (37/127, 29.2%) ( P = 0.047). Positive conjunctival sac secretion culture (123/322) was significantly associated with increased ocular secretion (281/322, 87.3%) (P = 0.002). Among the culture-positive bacteria in the conjunctival sac group and the lacrimal sac group, 30/127, 23.6% and 43/127, 26.7% and 21/85, 24.7% and 20/85, 23.5% were resistant to levofloxacin and tobramycin, respectively.

CONCLUSIONS

This study illustrated differences in bacterial distributions between conjunctival sac secretions and retained lacrimal sac fluid in chronic dacryocystitis patients, with a higher proportion of gram-negative bacilli in lacrimal sac secretions. The ocular surface flora in chronic dacryocystitis patients is partially resistant to levofloxacin and tobramycin, which need to be considered by ophthalmologists.

[Disorders of lacrimal drainage: the way from theory to practice]

The article summarizes the results of research conducted over the past decade concerning the current problems of dacryology, analyzes the improvements made to the methods of diagnostics used in disorders of lacrimal passages on the basis of modern imaging and functional studies, describes the techniques aimed at improving the clinical effectiveness of the intervention, as well as drug and non-drug methods of intraoperative prevention of excessive scarring in the area of the artificial ostium. The article also analyzes the experience of using balloon dacryoplasty in relapses of tear duct obstruction after dacryocystorhinostomy, and presents the modern minimally invasive surgical techniques, including nasolacrimal duct intubation, as well as balloon dacryoplasty and endoscopic plastic surgery of the ostium of the nasolacrimal duct. Additionally, the work lists the fundamental and applied tasks of dacryology and outlines promising directions of its development.

Quantitative analysis of both lacrimal glands in unilateral primary acquired nasolacrimal duct obstruction, based on three-dimensional fast spin echo-Cube-Flex

OBJECTIVE

To investigate whether unilateral primary acquired nasolacrimal duct obstruction (PANDO) changes the volume and water fraction of both lacrimal glands, using three-dimensional fast spin echo (3D-FSE)-Cube-Flex images, and to identify whether the lacrimal gland is a target organ in this disease.

METHODS

3D-FSE-Cube-Flex images of both lacrimal glands in 25 healthy volunteers and 31 patients with unilateral PANDO were retrospectively reviewed. The differences in volume and water content in the lacrimal glands between the controls, non-PANDO side, and PANDO side groups were examined. Moreover, the associations between magnetic resonance imaging (MRI) parameters and disease duration were assessed with correlation analysis.

RESULTS

The lacrimal gland volumes were not significantly different between the PANDO and non-PANDO side groups, compared to the control group (P = 0.484). However, the gland volumes tended to be increased bilaterally in patients with PANDO. In contrast, the gland water fractions in the PANDO and non-PANDO side groups were significantly higher than those in the control group (P = 0.009 and P = 0.014, respectively), and similar between the non-PANDO and PANDO side groups (P = 0.897). No correlation was found between the disease duration and the gland MRI parameters (volume and water fraction).

CONCLUSIONS

Both lacrimal glands are affected by unilateral PANDO. A change in the water fraction of these glands appears to precede the change in volume and may be a sensitive early indicator.

Identification of key genes and pathways in chronic rhinosinusitis with nasal polyps and asthma comorbidity using bioinformatics approaches

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and asthma comorbidity (ACRSwNP) present severe symptoms and are more likely to relapse. However, the pathogenesis of ACRSwNP is not fully understood. The aim of this study was to explore the underlying pathogenesis of ACRSwNP using bioinformatics approaches. ACRSwNP-related differentially expressed genes (DEGs) were identified by the analysis of the GSE23552 dataset. The clusterProfiler R package was used to carry out functional and pathway enrichment analysis. A protein–protein interaction (PPI) network was built using the STRING database to explore key genes in the pathogenesis of ACRSwNP. The bioinformatics analysis results were verified through qRT-PCR. The Connectivity Map (CMap) database was used to predict potential drugs for the treatment of ACRSwNP. A total of 36 DEGs were identified, which were mainly enriched in terms of regulation of immune response and detection sensory perception of taste. Thirteen hub genes including AZGP1, AQP9, GAPT, PIP, and PRR4 were identified as potential hub genes in ACRSwNP from the PPI network. Analysis of the GSE41861 dataset showed that upregulation of CST1 in nasal mucosa was associated with asthma. qRT-PCR detection confirmed the bioinformatics analysis results. Tacrolimus and spaglumic acid were identified as potential drugs for the treatment of ACRSwNP from the CMap database. The findings of this study provide insights into the pathogenesis of ACRSwNP and may provide a basis for the discovery of effective therapeutic modalities for ACRSwNP.

Prolactin Inducible Protein, but Not Prolactin, Is Present in Human Tears, Is Involved in Tear Film Quality, and Influences Evaporative Dry Eye Disease

Purpose

Decreased production of the aqueous component of the tear film is an important cause of the development of dry eye disease (DED). Tear production is influenced by hormones and hormone-like factors. Prolactin (PLR), a multifunctional pituitary gland hormone, is regularly present in the lacrimal gland of rats and rabbits. In humans, serum PLR concentration correlates with tear quality. To gain deeper insights of possible effects of PRL, prolactin receptor (PRLR) and prolactin inducible protein (PIP), we analyzed the three proteins in the human lacrimal apparatus and in reflex tears of healthy volunteers as well as patients suffering from DED.

Methods

Gene expression of PRLR and PIP was analyzed by RT-PCR in cadaveric human lacrimal gland and ocular surface tissues, immortalized human corneal epithelial cells (HCE and hTEPI) and human Meibomian gland epithelial cells (HMGECs). At the protein level, the expression and localization of PRL, PRLR and PIP in formalin-fixed paraffin sections of the lacrimal apparatus were studied by immunohistochemistry. In addition, tear fluid from DED patients and healthy volunteers was analyzed by ELISA to determine the concentration of PRL and PIP.

Results

RT-PCR analyses revealed gene expression of PRLR and PIP in human tissue samples of cornea, lacrimal glands, and eyelids, whereas only PIP, but not PRLR, was detectable in immortalized corneal epithelial cells. Immunohistochemistry revealed for the first time the expression and localization of PRL, PRLR, and PIP in human tissues of the lacrimal apparatus and at the ocular surface. PRL and PRLR were detectable in corneal epithelium, lacrimal glands, and Meibomian glands. Reflex tears from DED patients revealed significantly increased PIP concentrations, whereas PRL was undetectable in tears of DED patients and healthy volunteers.

Conclusion

PRL, PRLR, and PIP are found in the lacrimal apparatus and on the ocular surface. PIP, but not PRL, is present in human tears and appears to be involved in the physiology of tear film quality. Our clinical data revealed that PIP may affect tear quality, but further functional analyses are needed to fully elucidate the effects of PRL and PIP-associated factors in tear secretion as well as in the connection of DED.