Severe Neutropenia and Hepatotoxicity After Carbimazole Drug Therapy for Hyperthyroidism in a Pediatric Patient: A Case Report

BACKGROUND Hyperthyroidism is an overproduction of thyroid hormones. Carbimazole is an anti-thyroid medication used to treat hyperthyroidism in adults and children. It is a thionamide associated with rare adverse effects such as neutropenia, leukopenia, agranulocytosis, and hepatotoxicity. Severe neutropenia is a life-threatening event characterized by a sharp drop in absolute neutrophil count. Severe neutropenia can be treated by discontinuation of the precipitating medication. Administration of granulocyte colony-stimulating factor provides longer protection against neutropenia. Elevated liver enzymes indicate hepatotoxicity, which usually normalize after discontinuation of the offending medication. CASE REPORT A 17-year-old girl was treated with carbimazole since the age of 15 for hyperthyroidism secondary to Graves' disease. She initially received 10 mg of carbimazole orally twice daily. After 3 months, the patient's thyroid function reflected residual hyperthyroidism and was then up-titrated to 15 mg orally in the morning and 10 mg orally in the evening. She presented to the emergency department reporting fever, body aches, headache, nausea, and abdominal pain for 3 days. She was diagnosed with severe neutropenia and hepatotoxicity induced by carbimazole after 18 months of dose modification. CONCLUSIONS In hyperthyroidism, it is important to maintain patients in a euthyroid state for a long period to minimize the autoimmunity and hyperthyroid relapse, which often requires long-term use of carbimazole. However, severe neutropenia and hepatotoxicity are rare and serious adverse effects of carbimazole. Clinicians should be aware of the importance to discontinuation of carbimazole, administration of granulocyte colony-stimulating factors, and supportive treatment to reverse the consequences.

Students engagement using polls in virtual sessions of physiology, pathology, and pharmacology at King Saud bin Abdulaziz University for Health Sciences during COVID-19 pandemic: a cross-sectional study

BACKGROUND

Active involvement of students in class using technology is associated with effective learning and understanding. This work intended to analyze the impact of interactive teaching on medical students' engagement, learning, performance, understanding and attendance in virtual classes of physiology, pathology, and pharmacology during COVID-19 pandemic.

METHODS

A descriptive cross-sectional study was carried out at college of medicine at King Saud bin Abdulaziz University for Health Sciences (KSAU-HS) in Riyadh during January-April 2022. Third- and fourth-year medical students filled a self-reported questionnaire that assessed students' engagement, understanding, performance, and attendance during the sessions of three courses within the curriculum. The Chi-square test or Fisher's exact test was used to compare the difference between the survey responses.

RESULTS

A total of 184/234 questionnaires were completed and returned, with an overall response rate of 78.6%. Fifty-five percent of the participants were involved at least more than 5 times in polls during the class. Majority (86.9%), of the students agreed on enjoying participation in polls during the class, and 88.9% recommended the utilization of the polls again. Participation in polls improved understanding and performance of 88%, and 63% of students respectively. In addition, 38% were neutral regarding attendance improvement and spending more time for the class. Around 53% students agreed that polls improved their grades.

CONCLUSION

In conclusion, this study showed that there is an impact of using interactive polls in virtual classes in medical students at KSAU-HS. It is recommended to continue using polls in all subjects in on-site sessions. This will be a great preface step toward switching the traditional teaching to the interactive teaching using flipped classroom strategy in the future.

Do Parental Comorbidities Affect the Severity of Autism Spectrum Disorder?

Background Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by defective social communication and interaction with a repetitive pattern of monotonous or stereotyped behavior. Although the exact etiology of ASD is unknown, many factors may be implicated in the development of ASD. We aimed to determine the correlation between specific parental factors and Autism Treatment Evaluation Checklist (ATEC) scores. Methods This cross-sectional study was conducted at the Prince Nasser Bin Abdulaziz Center for Autism, Autism Center for Excellence, and Academy of Special Education for Autism in Riyadh, Saudi Arabia. We enrolled children diagnosed with ASD and their parents from these centers. Data were collected through self-administered questionnaires to the patients' parents. Results All included children were <18 years old. In total, 71 (92.2%) children were male and six (7.8%) were female. Further, 77 (100%) patients were diagnosed with autistic disorder. Children of consanguineous parents, underweight mothers and obese fathers, mothers with a history of depression during pregnancy, and mothers aged ≥31 years during pregnancy tend to have a higher mean ATEC score. The health domain was the most significantly correlated with ATEC scores, with a Pearson correlation of 0.880. In linear regression analysis, only maternal depression during pregnancy was significantly correlated with ATEC scores. Conclusion Our patients had a mean ATEC score of 86.2. The health domain was the most significantly correlated with ATEC scores, with a Pearson correlation of 0.880. Linear regression analysis revealed that consanguinity, parental chronic disease, parental allergy, smoking, drug use during pregnancy, paternal and maternal body mass index (BMI), and sibling number were not significantly correlated with ATEC scores (P=0.701, 0.693, 0.133, 0.874, 0.982, 0.255, 0.778, and 0.502, respectively). However, maternal depression during pregnancy was significantly correlated with ATEC scores (P=0.055).

Stimulation of synthesis and release of brain-derived neurotropic factor from intestinal smooth muscle cells by substance P and pituitary adenylate cyclase-activating peptide

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a neurotrophin present in the intestine where it participates in survival and growth of enteric neurons, augmentation of enteric circuits, and stimulation of intestinal peristalsis and propulsion. Previous studies largely focused on the role of neural and mucosal BDNF. The expression and release of BDNF from intestinal smooth muscle and the interaction with enteric neuropeptides has not been studied in gut.

METHODS

The expression and secretion of BDNF from smooth muscle cultured from the rabbit intestinal longitudinal muscle layer in response to substance P (SP) and pituitary adenylate cyclase-activating peptide (PACAP) was measured by western blot and enzyme-linked immunosorbent assay. BDNF mRNA was measured by reverse-transcription polymerase chain reaction.

KEY RESULTS

The expression of BNDF protein and mRNA was greater in smooth muscle cells (SMCs) from the longitudinal muscle than from circular muscle layer. PACAP and SP increased the expression of BDNF protein and mRNA in cultured longitudinal SMCs. PACAP and SP also stimulated the secretion of BDNF from cultured longitudinal SMCs. Chelation of intracellular calcium with BAPTA (1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) prevented SP-induced increase in BDNF mRNA and protein expression and SP-induced secretion of BDNF.

CONCLUSIONS & INFERENCES

Neuropeptides known to be present in enteric neurons innervating the longitudinal layer increase the expression of BDNF mRNA and protein in SMCs and stimulate the release of BDNF. Considering the ability of BDNF to enhance smooth muscle contraction, this autocrine loop may partially explain the characteristic hypercontractility of longitudinal muscle in inflammatory bowel disease.

Hypercontractility of intestinal longitudinal smooth muscle induced by cytokines is mediated by the nuclear factor-κB/AMP-activated kinase/myosin light chain kinase pathway

Recent studies have identified AMP-activated kinase (AMPK) as a target of Ca(2+)/calmodulin-dependent kinase kinase (CaMKKβ) and a negative regulator of myosin light-chain (MLC) kinase (MLCK). The present study examined whether a change in expression or activity of AMPK is responsible for hypercontractility of intestinal longitudinal muscle during inflammation or in response to proinflammatory cytokines. In mouse colonic longitudinal muscle cells, acetylcholine (ACh) stimulated AMPK and MLCK phosphorylation and activity and induced MLC20 phosphorylation and muscle contraction. Blockade of CaMKKβ with STO609 (7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid acetate) inhibited AMPK and MLCK phosphorylation and augmented MLCK activity, MLC20 phosphorylation, and smooth muscle cell contraction. In muscle cells isolated from the colon of TNBS (2,4,6-trinitrobenzenesulfonic acid)-treated mice or from strips treated with interleukin-1β or tumor necrosis factor-α, nuclear factor κB was activated as indicated by an increase in p65 phosphorylation and IκBα degradation, and AMPK was phosphorylated at a cAMP-dependent protein kinase (PKA)-specific site (Ser(485)) that is distinct from the stimulatory CaMKKβ site (Thr(172)), resulting in attenuation of ACh-stimulated AMPK activity and augmentation of MLCK activity and muscle cell contraction. Inhibition of nuclear factor-κB activity with MG-132 (carbobenzoxy-L-leucyl-L-leucyl-L-leucinal Z-LLL-CHO) or PKA activity with myristoylated PKA inhibitor 14-22 amide blocked phosphorylation of AMPK at Ser(485) and restored MLCK activity and muscle cell contraction to control levels. The results imply that PKA released from IκBα complex phosphorylated AMPK at a PKA-specific site and inhibited its activity, thereby relieving the inhibitory effect of AMPK on MLCK and increasing MLCK activity and muscle cell contraction. We conclude that hypercontractility of intestinal longitudinal muscle induced by inflammation or proinflammatory cytokines is mediated by nuclear factor κB/PKA-dependent inhibition of AMPK and activation of MLCK.

Changes in the expression of smooth muscle contractile proteins in TNBS- and DSS-induced colitis in mice

Thin filament-associated proteins such as calponin, caldesmon, tropomyosin, and smoothelin are thought to regulate acto-myosin interaction and thus, muscle contraction. However, the effect of inflammation on the expression of thin filament-associated proteins is not known. The aim of the present study is to determine the changes in the expression of calponin, caldesmon, tropomyosin, and smoothelin in colonic smooth muscle from trinitrobenzene sulphonic acid (TNBS)- and dextran sodium sulphate (DSS)-induced colitis in mice. Expression of h-caldesmon, h2-calponin, α-tropomyosin, and smoothelin-A was measured by qRT-PCR and Western blot. Contraction in response to acetylcholine in dispersed muscle cells was measured by scanning micrometry. mRNA and protein expression of α-actin, h2-calponin, h-caldesmon, smoothelin, and α-tropomyosin in colonic muscle strips from mice with TNBS- or DSS-induced colitis was significantly increased compared to control animals. Contraction in response to acetylcholine was significantly decreased in muscle cells isolated from inflamed regions of TNBS- or DSS-treated mice compared to control mice. Our results show that increase in the expression of thin filament-associated contractile proteins, which inhibit acto-myosin interaction, could contribute to decrease in smooth muscle contraction in inflammation.