[Clinical features of coronavirus disease 2019 in children aged <18 years in Jiangxi, China: an analysis of 23 cases]

OBJECTIVE

To study the clinical features of coronavirus disease 2019 (COVID-19) in children aged <18 years.

METHODS

A retrospective analysis was performed from the medical data of 23 children, aged from 3 months to 17 years and 8 months, who were diagnosed with COVID-19 in Jiangxi, China from January 21 to February 29, 2020.

RESULTS

Of the 23 children with COVID-19, 17 had family aggregation. Three children (13%) had asymptomatic infection, 6 (26%) had mild type, and 14 (61%) had common type. Among these 23 children, 16 (70%) had fever, 11 (48%) had cough, 8 (35%) had fever and cough, and 8 (35%) had wet rales in the lungs. The period from disease onset or the first nucleic acid-positive detection of SARS-CoV-2 to the virus nucleic acid negative conversion was 6-24 days (median 12 days). Of the 23 children, 3 had a reduction in total leukocyte count, 2 had a reduction in lymphocytes, 2 had an increase in C-reactive protein, and 2 had an increase in D-dimer. Abnormal pulmonary CT findings were observed in 12 children, among whom 9 had patchy ground-glass opacities in both lungs. All 23 children received antiviral therapy and were recovered.

CONCLUSIONS

COVID-19 in children aged <18 years often occurs with family aggregation, with no specific clinical manifestation and laboratory examination results. Most of these children have mild symptoms and a good prognosis. Epidemiological history is of particular importance in the diagnosis of COVID-19 in children aged <18 years.

[Clinical features of coronavirus disease 2019 in children aged <18 years in Jiangxi, China: an analysis of 23 cases]

OBJECTIVE

To study the clinical features of coronavirus disease 2019 (COVID-19) in children aged <18 years.

METHODS

A retrospective analysis was performed from the medical data of 23 children, aged from 3 months to 17 years and 8 months, who were diagnosed with COVID-19 in Jiangxi, China from January 21 to February 29, 2020.

RESULTS

Of the 23 children with COVID-19, 17 had family aggregation. Three children (13%) had asymptomatic infection, 6 (26%) had mild type, and 14 (61%) had common type. Among these 23 children, 16 (70%) had fever, 11 (48%) had cough, 8 (35%) had fever and cough, and 8 (35%) had wet rales in the lungs. The period from disease onset or the first nucleic acid-positive detection of SARS-CoV-2 to the virus nucleic acid negative conversion was 6-24 days (median 12 days). Of the 23 children, 3 had a reduction in total leukocyte count, 2 had a reduction in lymphocytes, 2 had an increase in C-reactive protein, and 2 had an increase in D-dimer. Abnormal pulmonary CT findings were observed in 12 children, among whom 9 had patchy ground-glass opacities in both lungs. All 23 children received antiviral therapy and were recovered.

CONCLUSIONS

COVID-19 in children aged <18 years often occurs with family aggregation, with no specific clinical manifestation and laboratory examination results. Most of these children have mild symptoms and a good prognosis. Epidemiological history is of particular importance in the diagnosis of COVID-19 in children aged <18 years.

Constitutive nuclear NF kappa B/rel DNA-binding activity of rat thymocytes is increased by stimuli that promote apoptosis, but not inhibited by pyrrolidine dithiocarbamate

Rat thymocytes spontaneously undergo apoptotic death in cell culture, and are also sensitive to the induction of apoptosis by various stimuli. We show that unstimulated thymocytes constitutively express a p50-containing nuclear factor kappa B (NF kappa B)/rel DNA-binding activity in their nuclei. When the cells were fractionated by density-gradient centrifugation this activity was found to be most pronounced in immature CD4+8+ thymocytes, the cell population that undergoes selection by apoptosis in vivo and that is most sensitive to external inducers of apoptosis in vitro. The intensity of the NF kappa B/rel protein-DNA complex was significantly enhanced 30 min after exposing thymocytes to methylprednisolone or etoposide, two agents well known to induce apoptosis in these cells. Expression of this DNA-binding activity therefore correlates with the subsequent occurrence of apoptosis. By analogy to other systems, it has been suggested that antioxidants such as pyrrolidine dithiocarbamate (PDTC) inhibit thymocyte apoptosis by preventing the activation of an NF kappa B/rel transcription factor. However, we have found that etoposide induces a very similar enhancement of the NF kappa B/rel DNA-binding activity in the presence or absence of PDTC, despite a pronounced inhibition of apoptotic DNA fragmentation in the former situation. Dithiocarbamates therefore do not exert their anti-apoptotic activity in thymocytes by inhibiting the activation of this transcription factor.

Chelation of intracellular zinc triggers apoptosis in mature thymocytes

BACKGROUND

Thymocyte apoptosis has been shown to be regulated by intracellular levels of cations. Elevation of [Ca2+]i can induce cell death by apoptosis, whereas, Zn2+ prevents it.

EXPERIMENTAL DESIGN

A membrane permeable metal ion chelator, N,N,N'N',-tetrakis (2-pyridylmethyl)ethylenediamine (TPEN), was used to examine the role of intracellular zinc in thymocyte (rat and human) apoptosis. Characteristics of apoptosis that were assessed included: chromatin degradation into oligosomal-sized fragments and nuclear condensation. The necessity for protein synthesis in TPEN-induced apoptosis was ruled out using the inhibitors, cycloheximide and emetine. Metal ion specificity for TPEN was established by competition with exogenous cations. FACS analysis was employed to determine the phenotype of the TPEN-sensitive thymocyte populations.

RESULTS

TPEN induced DNA fragmentation within 4 hours of exposure before the onset of cell death (6 hours). Addition of equimolar exogenous Zn2+ or Cu2+, but not Mn2+ or Fe2+, at the initiation of culture prevented TPEN-induced apoptosis. A membrane impermeable chelator, diethylenetriaminepentaacetic acid, did not induce thymocyte apoptosis indicating that chelation of intracellular Zn2+ was required to trigger DNA fragmentation. The identity of the critical intracellular Zn(2+)-binding site(s) is currently unknown, but it appears that increased thymocyte [Ca2+]i may displace Zn2+ from these intracellular sites. TPEN treatment resulted in the depletion of thymocytes having a mature phenotype with respect to CD3, CD4, and CD8. Moreover, lymph node cells were more sensitive to TPEN than thymocytes.

CONCLUSIONS

These experiments show that Zn2+ chelation has disparate effects on immature and mature T cells, and suggest that zinc availability controls the cell death or selection pathway during thymopoiesis.