Anti-diuretic action of a CAPA neuropeptide against a subset of diuretic hormones in the disease vector Aedes aegypti.

The mosquito Aedes aegypti is a vector responsible for transmitting various pathogens to humans, and their prominence as chief vectors of human disease is largely due to their anthropophilic blood feeding behaviour. Larval stage mosquitoes must deal with the potential dilution of their haemolymph in freshwater, whereas the haematophagus A. aegypti female faces the challenge of excess ion and water intake after a blood meal. The excretory system, composed of the Malpighian tubules (MTs) and hindgut, is strictly controlled by neuroendocrine factors, responsible for the regulation of diuresis across all developmental stages. The highly studied insect MTs are influenced by a variety of diuretic hormones and, in some insects, anti-diuretic factors. In the present study, we investigated the effects of AedaeCAPA-1 neuropeptide on larval and adult female A. aegypti MTs stimulated with various diuretic factors including serotonin (5-HT), a corticotropin-related factor (CRF) diuretic peptide, a calcitonin-related diuretic hormone (DH31) and a kinin-related diuretic peptide. Overall, our findings establish that AedaeCAPA-1 specifically inhibits secretion of larval and adult MTs stimulated by 5-HT and DH31, whilst having no activity on MTs stimulated by other diuretic factors. Furthermore, although AedaeCAPA-1 acts as an anti-diuretic, it does not influence the relative proportions of cations transported by adult MTs, thus maintaining the kaliuretic activity of 5-HT and natriuretic activity of DH31 In addition, we tested the effects of the second messenger cGMP in adult MTs. We established that cGMP has similar effects to AedaeCAPA-1, strongly inhibiting 5-HT- and DH31-stimulated fluid secretion, but with only minor effects on CRF-stimulated diuresis. Interestingly, although AedaeCAPA-1 has no inhibitory activity on kinin-stimulated fluid secretion, cGMP strongly inhibited fluid secretion by this diuretic hormone, which targets stellate cells specifically. Collectively, these results support that AedaeCAPA-1 inhibits select diuretic factors acting on the principal cells and this probably involves cGMP as a second messenger. Kinin-stimulated diuresis, which targets stellate cells, is also inhibited by cGMP, suggesting that another anti-diuretic factor in addition to AedaeCAPA-1 exists and may utilize cGMP as a second messenger.

Isolated Recurrent Pleural Effusions in a Patient With Rheumatoid Arthritis in Remission for Nine Years: A Case Report.

The development of pleural effusion in patients with active rheumatoid arthritis is a relatively common entity, yet it is uncommon in patients without clinical arthritis and other clinical features of disease flare-ups. This case report describes a 58-year-old patient with rheumatoid arthritis treated with sulfasalazine who developed recurrent large pleural effusion without clinical arthritis, after being in remission for nine years. Laboratory results showed neutrophilic leukocytosis, along with elevated inflammatory markers. Fluid analysis was suggestive of sterile exudative fluid, and adenosine deaminase of pleural fluid was negative. Culture and acid-fast bacilli of pleural fluid were both negative. Fluid cytology did not reveal any malignant cells. Chest X-ray showed right-sided pleural effusion, with underlying atelectasis. The clinical intervention included thoracentesis, piperacillin-tazobactam 4g q8 hr., prednisolone 10 mg, and sulfasalazine 1.5g. Upon hospital discharge, he was prescribed oral prednisolone 5 mg for two days, and colchicine 0.5 mg daily. After seven days, he presented with a recurrence of his symptoms and an X-ray revealed a new right-sided large pleural effusion. On the second admission, sulfasalazine was suspended, and he was switched to methotrexate. A remarkable improvement in the patient's condition was noted with an unremarkable X-ray and remained stable three months post-discharge on his following appointments as well. This report necessitates the need for the early diagnosis of a rheumatoid arthritis flare-up and the appropriate timely switch to the disease-modifying agent for better disease control.

Comprehensive description of the prevalence, serological and clinical characteristics, and visceral involvement of systemic sclerosis (scleroderma) in a large cohort from the United Arab Emirates Systemic Sclerosis Registry.

Systemic sclerosis is an autoimmune condition characterized by a wide range of clinical presentations. Registries may serve to expand understanding about systemic sclerosis and aid in patient care and follow-up. The objective of this study was to analyze the prevalence of systemic sclerosis in a large cohort from the United Arab Emirates Systemic Sclerosis Registry and find the significant similarities and differences between the different subsets. All scleroderma patients in the United Arab Emirates were included in this multicenter national retrospective analysis. Data on demographics, comorbidities, serological characteristics, clinical aspects, and treatment were collected and analyzed, highlighting the most common traits identified. A total of 167 systemic scleroderma patients from diverse ethnic backgrounds were enrolled. Overall, 54.5% (91/167) of the patients were diagnosed with diffuse cutaneous systemic sclerosis, and 45.5% (76/167) with limited cutaneous systemic sclerosis. The prevalence of systemic sclerosis was 1.66 per 100,000 for the total registry and 7.78 per 100,000 for United Arab Emirates patients. Almost all patients in the diffuse cutaneous systemic sclerosis and limited cutaneous systemic sclerosis groups tested positive for the immunofluorescence antinuclear antibody. Antibodies against Scl-70 were significantly more associated with diffuse cutaneous systemic sclerosis, whereas anticentromere antibodies were significantly more associated with the limited cutaneous systemic sclerosis group (p < 0.001). Sclerodactyly, shortness of breath, and digital ulcers were more common in diffuse cutaneous systemic sclerosis patients compared with the limited cutaneous systemic sclerosis subtype in terms of clinical symptoms and organ involvement. Telangiectasia was much more common in the limited cutaneous systemic sclerosis group. Furthermore, diffuse cutaneous systemic sclerosis patients had more lung fibrosis (interstitial lung disease) than limited cutaneous systemic sclerosis patients (70.5% vs 45.7%), and pulmonary arterial hypertension was twice as common in limited cutaneous systemic sclerosis patients as it was in diffuse cutaneous systemic sclerosis patients. Local registries are paramount to understanding the clinical/serological characteristics of scleroderma. This study emphasizes the importance of raising disease awareness and distinguishing between the various systemic sclerosis subsets to implement patient-tailored strategies for early detection, better management, and higher quality of care.

Paternal asthma is a predictor for childhood asthma in the consanguineous families from the United Arab Emirates.

Consanguinity is known to increase the burden of genetic disorders among offspring. However, the effect of consanguinity on a complex disorder like childhood asthma has not been studied previously. Therefore, we explored this relationship by studying the asthma prevalence in children between 6 and 14 years of age among the local Arab families of the United Arab Emirates (UAE) where consanguinity is known to be highly prevalent. A total of 1136 children from 295 families met our inclusion criteria. The prevalence of childhood asthma was higher among children in consanguineous families (43.3%) compared to non-consanguineous (22.6%, p < 0.001). There was a significant correlation between the degree of consanguinity and the number of asthmatic children per family (p = 0.0002). Girls from consanguineous families had proportionately more asthma (42.9%, p < 0.001) compared to boys (23.1%, p = 0.539). Paternal asthma in consanguineous families increased asthma risk for both boys and girls (p = 0.021 for boys, p < 0.001 for girls), while maternal asthma had no significant impact on asthma in offspring. Prevalence of childhood asthma was significantly higher in consanguineous families. The significant asthma predictors for girls from the consanguineous families were the degree of consanguinity and paternal asthma. The only predictor for boys was paternal asthma. These interesting observations merit further studies on both larger samples and in other consanguineous communities for confirmation.