Chronic Nodular Prurigo: An Update on the Pathogenesis and Treatment

Chronic nodular prurigo (CNPG) is a recalcitrant chronic itchy disorder that affects the quality of life. It can be triggered by multiple etiologies, such as atopic dermatitis, diabetes, and chronic renal diseases. The mechanisms of CNPG are complicated and involved the interaction of the cutaneous, immune, and nervous systems. Diverse immune cells, including eosinophils, neutrophils, T cells, macrophages, and mast cells infiltrated the lesional skin of CNPG, which initiated the inflammatory cytokines and pruritogens release. In addition, the interaction between the immune cells and activated peripheral sensory nerve fibers by neurotransmitters caused neuroinflammation in the skin and intractable itch. This itch-scratch vicious cycle of CNPG results in disease exacerbation. CNPG is difficult to treat with traditional therapies. Recently, great advances have been made in the pathophysiology of both inflammation and pruritus transmission in CNPG. In this review, we summarize the updated mechanisms and novel therapies for CNPG.

Increased Epidermal Nerve Growth Factor without Small-Fiber Neuropathy in Dermatomyositis

Small-fiber neuropathy (SFN) is suggested to be involved in the pathogenesis of some types of autoimmune connective tissue diseases. SFN with a reduction in epidermal nerve fibers might affect sensory fibers and cause neuropathic symptoms, such as pruritus and pain, which are common in both dermatomyositis (DM) and cutaneous lupus erythematosus (CLE). Nerve growth factor (NGF) has been recognized as important in nociception by regulating epidermal nerve fiber density and sensitizing the peripheral nervous system. The present study aimed to investigate whether SFN was associated with the cutaneous manifestations of DM and CLE. We also investigated the relationship between SFN and axon guidance molecules, such as NGF, amphiregulin (AREG), and semaphorin (Sema3A) in DM and CLE. To explore the molecular signaling, interleukin (IL)-18 and IL-31, which have been implicated in the cutaneous manifestation and neuropathic symptoms in DM, were examined in keratinocytes. Our results revealed that intraepidermal nerve fiber density (IENFD) was unchanged in patients with DM, but significantly reduced in IENFD in patients with CLE compared with healthy control. Increased epidermal expression of NGF and decreased expression of Sema3A were demonstrated in patients with DM. Furthermore, IL-18 and IL-31 both induced the production of NGF from keratinocytes. Taken together, IL-18 and IL-31 mediated epidermal NGF expression might contribute to the cutaneous neuropathic symptoms in DM, while SFN might be important for CLE.

Autoimmune Connective Tissue Diseases-Related Pruritus: Proper Diagnosis and Possible Mechanisms

Pruritus is a well-known bothersome symptom among skin disorders, especially inflammatory skin disorders. Lately, a high prevalence of pruritus in patients with autoimmune connective tissue diseases (ACTDs) has been revealed. Patients with ACTDs may suffer from varying degrees of pruritus, which affect their quality of life. However, it is rarely recognized both by patients and physicians. Meanwhile, pruritus is not only a symptom but is also related to the disease severity of some ACTDs. The pathophysiology of ACTD related pruritus is ambiguous. This review summarizes the features and possible mechanisms of ACTD-related pruritus, which might lead to proper diagnosis and treatment.

Blunt Traumatic Cardiac Rupture Presenting as Massive Haemothorax

Cardiac rupture following blunt thoracic trauma in motor vehicle crash generally causes death at scene, and is rarely diagnosed preoperatively. However, early emergency thoracotomy in the emergency department (ED) or operating room might reduce the mortality but the benefit is still controversial. A haemodynamically unstable 28-year-old woman following motor vehicle crash was detected to have right haemothorax on chest X-ray. Thoracic computed tomography (CT) revealed additional lung contusions and multiple bone fractures. She developed cardiac arrest during open thoracotomy and had restored spontaneous circulation after open-chest cardiopulmonary resuscitation (CPR). This report highlights that CT scan in haemodynamically unstable patients could delay surgical control of the injury. Open-chest CPR can be life-saving for blunt chest injury developing cardiac arrest. (Hong Kong j.emerg.med. 2015;22:320-323)

Expression of sex-determining genes in the scalp of men with androgenetic alopecia

BACKGROUND

The regulation of the cutaneous steroidogenesis in patients with androgenetic alopecia remains largely unclear.

OBJECTIVE

The purpose of this study was to quantify the expression of the sex-determining genes in different scalp areas.

METHODS

Paired scalp specimens from frontal and occipital scalp areas of 10 patients were examined by real-time RT-PCR for mRNA expression and of 40 patients (mean age 34.9 years, range 22-58) by Western blotting for protein analysis.

RESULTS

The SOX-9 mRNA was most abundant in the skin, while SF-1 mRNA was sparsely detected. The protein levels of DAX-1, SRY and WT-1 were significantly higher in the bald scalp (p=0.003, 0.004 and 0.03, respectively). Only the SRY expression showed a positive correlation with the baldness severity in Norwood-Hamilton classification (p=0.024). There was no association between patient's age and the protein levels. Immunostaining of SOX-9 was detected in the outer root sheath keratinocytes of hair follicles but not in the dermal papillae.

CONCLUSION

Further study on a larger population, including normal subjects and female patients, is needed to confirm the pathogenic role of sex-determining genes in androgenetic alopecia.

Developing an NLP and IR-based algorithm for analyzing gene-disease relationships

OBJECTIVES

High-throughput techniques such as cDNA microarray, oligonucleotide arrays, and serial analysis of gene expression (SAGE) have been developed and used to automatically screen huge amounts of gene expression data. However, researchers usually spend lots of time and money on discovering gene-disease relationships by utilizing these techniques. We prototypically implemented an algorithm that can provide some kind of predicted results for biological researchers before they proceed with experiments, and it is very helpful for them to discover gene-disease relationships more efficiently.

METHODS

Due to the fast development of computer technology, many information retrieval techniques have been applied to analyze huge digital biomedical databases available worldwide. Therefore we highly expect that we can apply information retrieval (IR) technique to extract useful information for the relationship of specific diseases and genes from MEDLINE articles. Furthermore, we also applied natural language processing (NLP) methods to do the semantic analysis for the relevant articles to discover the relationships between genes and diseases.

RESULTS

We have extracted gene symbols from our literature collection according to disease MeSH classifications. We have also built an IR-based retrieval system, "Biomedical Literature Retrieval System (BLRS)" and applied the N-gram model to extract the relationship features which can reveal the relationship between genes and diseases. Finally, a relationship network of a specific disease has been built to represent the gene-disease relationships.

CONCLUSIONS

A relationship feature is a functional word that can reveal the relationship between one single gene and a disease. By incorporating many modern IR techniques, we found that BLRS is a very powerful information discovery tool for literature searching. A relationship network which contains the information on gene symbol, relationship feature, and disease MeSH term can provide an integrated view to discover gene-disease relationships.

Nucleotide sequence of a novel arylesterase gene from Vibro mimicus and characterization of the enzyme expressed in Escherichia coli

A gene coding for an arylesterase of Vibrio mimicus was cloned. Sequence determination reveals that the esterase gene has an open reading frame of 600 nucleotides which encodes a protein of M(r) 22,300. The deduced amino acid sequence contain a pentapeptide GDSLS (residues 27-31), which was also found in the phospholipid-cholesterol acyltransferase from Aeromonas hydrophila. Substitution of Ser-29 by alanine or cysteine in the cloned gene abolished the esterase activity in the tributyrin plate assay. On the other hand, the activity was not lost when Ser-31 was changed to alanine. The cloned gene was expressed in Escherichia coli, and the protein purified by a four-step procedure. The purified protein migrated on SDS/PAGE as a single band with an apparent M(r) of 22,100. This enzyme favoured the hydrolysis of several arylesters and was classified as an arylesterase (EC 3.1.1.2). N-Terminal analysis showed that Ser-20 was the first amino acid of the mature secreted protein, suggesting that the N-terminal 19 hydrophobic amino acids served as a signal peptide.

Potentiation of thyrotropin-releasing hormone-stimulated prolactin mRNA levels in GH3 cells by acetylcholine

We have examined the effect of acetylcholine (ACh) pretreatment on the thyrotropin-releasing hormone (TRH) induced prolactin gene expression in GH3 cells, a rat pituitary tumor cell line. Prolonged exposure (greater than 6 h) to ACh enhanced the TRH-induced prolactin mRNA accumulation in a time- and concentration-dependent manner while ACh by itself did not affect the basal prolactin mRNA levels appreciably. Maximal augmentation of the TRH-induced prolactin mRNA accumulation was obtained when cells were pretreated with 10(-5) M ACh for 24 h. The activation was mimicked by carbachol and oxotremorine and was blocked by the simultaneous presence of atropine. Preincubation of GH3 cells with pertussis toxin abolished the augmenting effect of ACh. These results indicate that prolonged exposure to muscarinic receptor agonists may enhance the TRH-stimulated prolactin mRNA expression and a pertussis toxin sensitive G-protein may be involved.

Expression of c-myc proto-oncogene during podophyllotoxin induced IW32 erythroleukemia cell differentiation

The effect of hemin or podophyllotoxin on the differentiation of the erythropoietin (epo)-producing IW32 erythroleukemia cells was investigated. Podophyllotoxin induced IW32 cells to differentiate, and hemin potentiated the differentiation. Hemin had no effect on cell proliferation whereas podophyllotoxin inhibited cell growth. c-myc mRNA levels decreased biphasically by hemin or podophyllotoxin, while the combined treatment of hemin plus podophyllotoxin did not result in the initial decrease in c-myc mRNA level. Our data suggested that down-regulation of c-myc expression was not a prerequisite of IW32 cell differentiation induced by hemin and podophyllotoxin combined.