Foveal pit morphological changes in asymptomatic carriers of the G11778A mutation with Leber’s hereditary optic neuropathy

AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.

Traveling wave solutions for a discrete diffusive epidemic model with asymptomatic carriers

This paper mainly concerns about the traveling wave solution(TwS)for a discrete diffusive epidemic model with asymptomatic carriers.Analysis of the model shows that the minimum wave speed c*exists if a threshold is greater than one.With the help of sub-and super-solutions,we find that the condition for the existence of TWS is R>1 and wave speed c>c^(*).Further,we prove that the TwS connects two different boundary steady states.Through the arguments with Laplace transform,we show there is no TWS for the model if R>1 and o<c<c^(*)or R≤1.

Distribution of Plasmodium spp.infection in asymptomatic carriers in perennial and low seasonal malaria transmission settings in West Africa

countries in West Africa remain a hotspot for malaria with all age groups at risk.Asymptomatic carriers of Plasmodium spp.are important sources of infections for malaria vectors and thus contribute to the anchoring of the disease in favourable eco-epidemiological settings.The objective of this study was to assess the asymptomatic malaria case rates in Korhogo and Kaedi,two urban areas in northern Côte d’Ivoire and southern Mauritania,respectively.Methods:Cross-sectional surveys were carried out during the rainy season in 2014 and the dry season in 2015 in both settings.During each season,728 households were randomly selected and a household-based questionnaire was implemented to collect demographic and epidemiological data,including of malaria preventive methods used in communities.Finger-prick blood samples were obtained for biological examination using microscopy and rapid diagnostic tests(RDTs).Results:Overall,2672 households and 15858 consenting participants were surveyed.Plasmodium spp.infection was confirmed in 12.4%(n=832)and 0.3%(n=22)of the assessed individuals in Korhogo and Kaedi,respectively.In Korhogo,the prevalence of asymptomatic malaria was 10.5%(95%CI:9.7-11.2)as determined by microscopy and 9.3%(95%CI:8.6-10.0%)when assessed by RDT.In Kaedi,asymptomatic malaria prevalence was 0.2%(95%CI:0.1-0.4%)according to microscopy,while all RDTs performed were negative(n=8372).In Korhogo,asymptomatic malaria infection was significantly associated with age and season,with higher risk within the 5-14 years-old,and during the rainy season.In Kaedi,the risk of asymptomatic malaria infection was associated with season only(higher during the dry season;crude OR(cOR):6.37,95%CI:1.87-21.63).P.falciparum was the predominant species identified in both study sites representing 99.2%(n=825)in Korhogo and 59.1%(n=13)in Kaedi.Gametocytes were observed only in Korhogo and only during the rainy season at 1.3%(95%CI:0.7-2.4%).Conclusions:Our findings show a low prevalence of clinical malaria episodes with a significant proportion of asymptomatic carriers in both urban areas.National policies for malaria infections are focused on treatment of symptomatic cases.Malaria control strategies should be designed for monitoring and managing malaria infections in asymptomatic carriers.Additional measures,including indoor residual spraying,effective use of long-lasting insecticidal nets is strongly needed to reduce the number of Plasmodium spp.infections in Korhogo and Kaedi.

Differential gene expression between asymptomatic HBV carriers and normal adults

BACKGROUND: There are more than 100 million wa symptomatic HBV carriers (ASCs) in China and they are at a high risk of developing liver disease, which creates a serious health problem. But more than 90% of normal adults clear virus from primary HBV infection, so the difference of gene expression between ASCs and normal adults determines the differential outcomes. To identify differentially expressed genes in ASCs compared to normal adults, we used suppression subtractive hybridization to compare gene expression. METHODS: cDNA subtracted libraries were constructed by suppression subtracted hybridization from peripheral blood monocytes of ASCs and normal adults, the subtracted clones were prescreened by dot blot hybridization, and the levels of genes of interest were confirmed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: One hundred and two and 96 positive clones were acquired from the A-N and N-A libraries, respectively, and 14 and 11 clones were identified by dot blot hybridization in the A-N and N-A libraries. Two genes were confirmed as differentially expressed between a set of ASC and normal adult samples by real-time RT-PCR. CONCLUSIONS: Differentially expressed genes in peripheral blood mononuclear cells between ASCs and normal adults were isolated by suppression subtractive hybridization, and included some new genes. Of the upregulated genes in ASCs, checkpoint suppressor I is associated with DNA damage-induced cell cycle arrest. Perforin I is associated with inflammation. The information about such alterations in gene expression could be useful for elucidating the mechanisms of ASC pathogenesis.

Liver test abnormalities in asymptomatic and mild COVID-19 patients and their association with viral shedding time

BACKGROUND Asymptomatic infections and mild symptoms are common in patients infected with the Omicron variant,and data on liver test abnormalities are rare.AIM To evaluated the clinical characteristics of asymptomatic and mild coronavirus disease 2019(COVID-19)patients with abnormal liver test results.METHODS This retrospective study included 661 laboratory-confirmed asymptomatic and mild COVID-19 patients who were treated in two makeshift hospitals in Ningbo from April 5,2022 to April 29,2022.Clinical information and viral shedding time were collected,and univariate and multivariate logistic regression models were performed in statistical analyses.RESULTS Of the 661 patients,83(12.6%)had liver test abnormalities,and 6(0.9%)had liver injuries.Abnormal liver tests revealed a reliable correlation with a history of liver disease(P<0.001)and a potential correlation with male sex and obesity(P<0.05).Elevated alanine aminotransferase was reliably associated with obesity(P<0.05)and a history of liver disease(P<0.001).Elevated aspartate transaminase(AST)was reliably correlated with a history of liver disease(P<0.001),and potentially correlated with age over 30 years(P<0.05).There was a reliable correlation between AST≥2×the upper limit of normal and a longer viral shedding time,especially in mild cases.CONCLUSION Obesity and a history of liver disease are risk factors for liver test abnormalities.Being male and an older age are potential risk factors.Attention should be given to liver tests in asymptomatic and mild COVID-19 patients,which has crucial clinical significance for evaluating the viral shedding time.

Photoreceptor changes in Leber hereditary optic neuropathy with m.G11778A mutation

·AIM:To evaluate the functional and structural changes of photoreceptors in patients and asymptomatic carriers with Leber hereditary optic neuropathy(LHON)using fullfield electroretinography(FERG)and optical coherence tomography(OCT).·METHODS:Individuals diagnosed with LHON at the Renmin Hospital of Wuhan University and their family members were included in this cross-sectional observational study.The FERG a-wave amplitude of affected patients and asymptomatic carriers was analyzed.The thickness of the outer nuclear layer(ONL),inner and outer segment(IS/OS)and total photoreceptors in the macular fovea and parafovea were measured.·RESULTS:This study included 14 LHON patients(mean age:20.00±9.37y),12 asymptomatic carriers(mean age:39.83±6.48y),and 14 normal subjects(mean age:24.20±1.52y).The FERG results showed that the darkadapted 3.0 electroretinography and light-adapted 3.0 electroretinography a-wave amplitudes of patients and carriers were significantly decreased(P<0.001).The ONL and photoreceptors layers were slightly thicker in patients than in normal subjects(P<0.05),whereas they were thinner in carriers(P<0.05).There were no differences in IS/OS thickness among the groups(P>0.05).·CONCLUSION:Photoreceptors function is significantly impaired in LHON-affected patients and asymptomatic carriers.Meanwhile,photoreceptors morphology is slightly altered,mainly manifesting as a change in ONL thickness.

Fatal hemophagocytic lymphohistiocytosis-induced multiorgan dysfunction secondary to Burkholderia pseudomallei sepsis: A case report

BACKGROUND Burkholderia pseudomallei(B.pseudomallei)is a short,straight,medium-sized Gramnegative bacterium that mostly exists alone,without a capsule or spores,has more than three flagella at one end,and actively moves.B.pseudomallei confers high morbidity and mortality,with frequent granulocytopenia in B.pseudomallei sepsisrelated deaths.However,mortality may be related to hemophagocytic lymphohistiocytosis(HLH)secondary to B.pseudomallei infection.CASE SUMMARY A 12-year-old female was referred from a local hospital to the pediatric intensive care unit with suspected septic shock and fever,cough,dyspnea,and malaise.After admission,supportive symptomatic treatments including fluid resuscitation,anti-infective therapy,mechanical ventilation,and a vasoactive drug maintenance cycle were carefully initiated.The patient became unconscious,her blood pressure could not be maintained even under the exposure of vasoactive drugs,and she experienced cardiorespiratory arrest.The patient died due to ineffective high-quality in-hospital cardiopulmonary resuscitation.A subsequent bone marrow smear examination revealed extensive phagocytosis,and the blood culture was positive for B.pseudomallei.Family history revealed a sibling death from B.pseudomallei sepsis 5 years earlier.CONCLUSION The higher mortality rate in patients with B.pseudomallei sepsis may be related to secondary HLH after infection,wherein multiorgan dysfunction syndrome may be directly related to infection or immune damage caused by secondary HLH.Patients with B.pseudomallei can be asymptomatic and can become an infective source.

Estimated prevalence and viral transmissibility in subjects with asymptomatic SARS-CoV-2 infections in Wuhan,China

The role of subjects with asymptomatic SARS-CoV-2 infection in the current pandemic is notwell-defined.Based on two different approaches to estimate the culminative attack rate(seroprevalence of antibodies against SARSCoV-2,and a four compartment mathematical model)and the reported number of patients with COVID-19,the ratio of asymptomatic versus symptomatic SARS-CoV-2 infection was estimated to be 7(95%CI:2.8–12.4)in Wuhan,Hubei,China,the first epicenter of this pandemic,which has settled with no new cases.Together with detailed recording of the contact sources in a cohort of patients,and applying the estimations to an established mathematical model,the viral transmissibility of the subjects with asymptomatic SARS-CoV-2 infection is around 10%of that of the symptomatic patients(95%CI:7.6%–12.3%).Public health measures/policies should address this important pool of infectious source in combat against this viral pandemic.

SARS-CoV-2 reinfection in two patients who have recovered from COVID-19

Dear Editor,The duration of immune protection against SAR-CoV-2 reinfection in patients who have recovered from COVID-19 is a critical unanswered question.To determine the long-term clinical and virologic outcome in patients who have recovered from COVID-19,we prospectively followed 220 patients with COVID-19 admitted to Renmin Hospital of Wuhan University between 15 January and 15 February 2020 who recovered and were followed up until 15 July 2020.

Deterministic epidemic model for (SVC_(Sy)C_(Asy)IR) pneumonia dynamics, with vaccination and temporal immunity

Streptococcus pneumonia is one of the leading causes of mobility and mortality in children under 6 years and the elderly especially in developing countries in which Ghana,the study area is not an exception.In this paper,a model of the spread and control of bacterial pneumonia that include symptomatic carriers,asymptomatic carriers and vaccination is formulated and analyzed to determine the effect of the vaccination intervention.Analysis of the system show that the disease free equilibrium is stable if and only if the basic reproductive number R0<1.For R01,the endemic equilibrium is globally stable and the disease persist.Numerical simulation on the system show that with effective vaccine intervention pneumonia infection can be eradicated in the long term.