Subconjunctival injection of human umbilical cord mesenchymal stem cells alleviates experimental allergic conjunctivitis via regulating T cell response

BACKGROUND

T helper 2 (Th2) cells are thought to play critical roles in allergic conjunctivitis (AC). They release inflammatory cytokines to promote an allergic response in AC. Due to individual heterogeneity and long-term chronic management, current therapies do not always effectively control AC. Mesenchymal stem cells (MSCs) have been shown to be effective in treating allergy-related disorders, but it is unclear how exactly the Th2-mediated allergic response is attenuated. This study aims to elucidate the therapeutic effect and mechanism of the human umbilical cord MSCs (hUCMSCs) in a mouse model of experimental AC (EAC).

METHODS

A mouse EAC model was established by inoculating short ragweed (SRW) pollen. After the SRW pollen challenge, the mice received a single subconjunctival or tail vein injection of 2 × 106 hUCMSCs, or subconjunctival injection of hUCMSCs conditioned medium (hUCMSC-CM), and dexamethasone eye drops was used as positive control; subsequent scratching behavior and clinical symptoms were assessed. Immunostaining and flow cytometry were carried out to show allergic reactions and the activation of CD4 + T cell subsets in the conjunctiva and cervical lymph nodes (CLNs). Gene expression was determined by RNA-seq and further verified by qRT-PCR and Western blot. Co-culture assays were performed to explore the regulatory role of hUCMSCs in the differentiation of CD4 + naive T cells (Th0) into Th2 cells.

RESULTS

Subconjunctival administration of hUCMSCs resulted in fewer instances of scratching and lower inflammation scores in EAC mice compared to the tail vein delivery, hUCMSC-CM and control groups. Subconjunctival administration of hUCMSCs reduced the number of activated mast cells and infiltrated eosinophils in the conjunctiva, as well as decreased the number of Th2 cells in CLNs. After pretreatment with EAC mouse serum in vitro to mimic the in vivo milieu, hUCMSCs were able to inhibit the differentiation of Th0 into Th2 cells. Further evidence demonstrated that repression of Th2 cell differentiation by hUCMSCs is mediated by CRISPLD2 through downregulation of STAT6 phosphorylation. Additionally, hUMCSCs were able to promote the differentiation of Th0 cells into regulatory T cells in CLNs of EAC mice.

CONCLUSIONS

Subconjunctival injection of hUCMSCs suppressed the Th2-allergic response and alleviated clinical symptoms. This study provides not only a potential therapeutic target for the treatment of AC but also other T cell-mediated diseases.

An Approach Toward Assessing Head-and-Neck Lymphedema Using Tissue Dielectric Constant Ratios: Method and Normal Reference Values

Background: There are multiple methods to quantitatively assess limb lymphedema, but quantitative methods to assess external lymphedema in persons with head-and-neck lymphedema are quite limited. Quantification in this difficult condition currently uses multiple time-consuming head, face, and neck metric measurements, the accuracy of which is unclear. Thus, there is an important need for a new approach that is sufficiently convenient yet accurate to quantify head-and-neck lymphedema. The approach adopted was to use tissue dielectric constant (TDC) measurements that depend on tissue water, at neck and a submental area, and normalize these to TDC values at the forearm as a way to develop subject-independent indices. Methods and Results: TDC was measured in 60 self-reported healthy nonlymphedematous adults (34 female, 18-81 years, 18.5-45.7 Kg/m²) at two neck sites and one arm site bilaterally and at a submental area. Neck-to-arm-index (NAI) and submental-to-arm-index (SAI) ratios were calculated. TDC values (mean ± standard deviation [SD]) for neck, submental, and arm were, respectively, 37.4 ± 6.9, 35.9 ± 7.7, and 30.1 ± 4.6. Mean NAI and SAI values were 1.253 ± 0.222 and 1.214 ± 0.296 respectively. Head-and-neck lymphedema thresholds calculated as mean + 2.5 SD were for NAI and SAI 1.80 and 1.95, respectively. Conclusions: An approach to help quantify and track head-and-neck lymphedema using TDC neck and/or submental values normalized to a person's forearm TDC values indicates threshold values between 1.80 and 1.95. These ratios, denoted as NAI and SAI, are suggested for use to detect and track changes in lymphedema status based on a patient's changing indices associated with lymphedema treatment.

Lymph Vessel Thrombus Detection in Cervical Lymphedema: A Case Series

Although thrombosis in the terminal part of thoracic duct has been described in patients with head and neck cancer and upper vein thrombosis, normally medical imaging is not successful in depicting such lymphatic thrombosis. This case series is about three patients with acute onset of cervical lymphedema following minor trauma or exceptional physical strain. Using high-resolution ultrasound, it was possible to detect a thrombus formation in the terminal parts of the thoracic duct or the lymph duct. Within a few weeks all patients recovered without relapse for several years.

Robot-Assisted Neck Dissection Through a Modified Facelift Incision

Objectives:

The aim of this study is to describe the feasibility as well as oncologic outcomes of robot-assisted neck dissection (RAND) through a modified facelift incision in an American population.

Study Design:

Retrospective case series.

Setting:

University tertiary care hospital.

Methods:

All patients who underwent RAND between November 2012 and December 2014 were included. Medical records were reviewed for demographics, medical histories, staging, operative information, postoperative hospital course and complications, and oncologic outcomes.

Results:

There were 11 RANDs identified among 10 patients. Five patients had known nodal metastasis at the time of surgery. Two patients had been previously irradiated. The average time of surgery was 284.4 ± 72.3 minutes, including other associated procedures. The average lymph node yield was 28.5 ± 9.3 nodes. There were no major complications. Average follow-up was 19.4 months. There was 1 supraclavicular recurrence in a previously irradiated patient. All patients are currently alive and without evidence of disease.

Conclusions:

Robot-assisted neck dissection is a safe and feasible procedure that can be performed by surgeons with familiarity with neck dissection and robot-assisted surgery and who have been trained in RAND. Appropriate oncologic outcomes can be obtained in a patient wishing to avoid a noticeable scar.

Treatment and outcomes of head and neck oedema referrals to a hospital-based lymphoedema service

A retrospective review of all head and neck cancer-related lymphoedema (HNCRL) referrals from 1 October 2009 to 30 September 2013 was undertaken. HNCRL referrals significantly increased over a 4-year period. Lymphoedema clinic records were manually examined for the presentation of HNCRL, treatments provided, and outcomes. Some 207 HNCRL referrals were received, increasing by 251% from 2009 to 2013. A total of 110 men and 50 women were assessed and treated over the 4 years; 67% were discharged, 26% continued treatment/monitoring by clinic; 8% are deceased. The average time to discharge reduced from 16 to 5 months. From the results, it seems that self-management with exercise and counter-pressure/compression is very effective and the requirement for manual lymph drainage is reduced. There is increased patient engagement with effective self-care. Provision of appropriate education and information facilitated simple, effective self-management. This reduced treatment time, shortened time to discharge and released valuable practitioner time to treat patients with complex oedema.

Generalized lymphedema associated with neurologic signs (GLANS) syndrome: a new entity?

BACKGROUND

Primary lymphedema in children, especially generalized disease with facial involvement, is rare.

OBJECTIVE

We sought to report 3 childhood cases of lymphedema with associated neurologic findings and to provide a pathophysiologic explanation for this association.

METHODS

Clinical observations, electroencephalography, and neuroimaging studies were evaluated. Microcomparative genomic hybridization was performed in 1 case.

RESULTS

The 3 children had primary lymphedema of all 4 limbs and the face. This was confirmed by lymphoscintigraphy, which showed hypoplasia of vessels and hypofixation of lymph nodes. They had nonspecific neurologic disorders and electroencephalography abnormalities, without intellectual deficit. Neuroimaging revealed normal findings. Microcomparative genomic hybridization in 1 patient revealed no cytogenetic anomaly. The outcome was fatal in 1 case with development of visceral lymphedema and coma.

LIMITATIONS

Genetic studies were performed in only 1 case.

CONCLUSION

These observations suggest that neurologic assessment and electroencephalography are indicated for patients with lymphedema of the limbs and face to identify this syndrome.