[A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020]

OBJECTIVES

To investigate the clinical characteristics and prognosis of pneumococcal meningitis (PM), and drug sensitivity of Streptococcus pneumoniae (SP) isolates in Chinese children.

METHODS

A retrospective analysis was conducted on clinical information, laboratory data, and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.

RESULTS

Among the 160 children with PM, there were 103 males and 57 females. The age ranged from 15 days to 15 years, with 109 cases (68.1%) aged 3 months to under 3 years. SP strains were isolated from 95 cases (59.4%) in cerebrospinal fluid cultures and from 57 cases (35.6%) in blood cultures. The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87) and 27% (21/78), respectively. Fifty-five cases (34.4%) had one or more risk factors for purulent meningitis, 113 cases (70.6%) had one or more extra-cranial infectious foci, and 18 cases (11.3%) had underlying diseases. The most common clinical symptoms were fever (147 cases, 91.9%), followed by lethargy (98 cases, 61.3%) and vomiting (61 cases, 38.1%). Sixty-nine cases (43.1%) experienced intracranial complications during hospitalization, with subdural effusion and/or empyema being the most common complication [43 cases (26.9%)], followed by hydrocephalus in 24 cases (15.0%), brain abscess in 23 cases (14.4%), and cerebral hemorrhage in 8 cases (5.0%). Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old, with rates of 91% (39/43) and 83% (20/24), respectively. SP strains exhibited complete sensitivity to vancomycin (100%, 75/75), linezolid (100%, 56/56), and meropenem (100%, 6/6). High sensitivity rates were also observed for levofloxacin (81%, 22/27), moxifloxacin (82%, 14/17), rifampicin (96%, 25/26), and chloramphenicol (91%, 21/23). However, low sensitivity rates were found for penicillin (16%, 11/68) and clindamycin (6%, 1/17), and SP strains were completely resistant to erythromycin (100%, 31/31). The rates of discharge with cure and improvement were 22.5% (36/160) and 66.2% (106/160), respectively, while 18 cases (11.3%) had adverse outcomes.

CONCLUSIONS

Pediatric PM is more common in children aged 3 months to under 3 years. Intracranial complications are more frequently observed in children under 1 year old. Fever is the most common clinical manifestation of PM, and subdural effusion/emphysema and hydrocephalus are the most frequent complications. Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates. Adverse outcomes can be noted in more than 10% of PM cases. SP strains are high sensitivity to vancomycin, linezolid, meropenem, levofloxacin, moxifloxacin, rifampicin, and chloramphenicol.

[A multicenter epidemiological study of acute bacterial meningitis in children]

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.

[A survey of attitudes to and demands on internship in graduates majoring in preventive medicine in 6 colleges and universities in China]

Objective: To understand the internship of students majoring in preventive medicine in 6 colleges and universities in China, and provide reference suggestions for the improvement of internship arrangement. Methods: By using the method of combined clustering and convenient sampling, the fifth grades students majoring in preventive medicine in six universities in the eastern, central and western China were surveyed by using questionnaires to collect the information of their attitudes (to) and suggestions for clinical and public health internships. Results: A total of 596 students were surveyed. In terms of the benefits of clinical internship and public health internship, students who thought that the internship was fruitful accounted for >88%, and more students thought that reform is needed in clinical internship compared with public health internship. In clinical internship, the students through that the time arrangement was not appropriate enough (95, 39.58%), the content should be more detailed and in-depth (73, 30.42%) and the content did not conform to the professional direction (54, 22.50%). In public health internship, the students thought that the time arrangement was not appropriate (77, 45.56%), the content should be more detailed and standardized (65, 38.46%) and the types of internship bases should be more diversified (20, 11.83%). Conclusions: The undergraduates majoring in preventive medicine felt to be benefited from clinical practice and public health internships and thought they are of necessity. At the same time, there are still many problems which needs to be improved in the two types of internships. It is necessary to make joint efforts from students, teachers, colleges and practice bases to promote the continuous improvement of undergraduate internship.

[Management programs on diabetes among Chinese adults in the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases]

Objective: To understand the current situation on management of diabetes mellitus patients aged 35 and above in the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases, in China. Methods: Local residents, aged 18 years and above were randomly selected by a complex, multistage, probability sampling method. Face-to-face questionnaire survey was carried out between November and December 2016. Rates regarding prevalence, treatment and management of diabetes were calculated, and influencing factors of diabetes were analyzed by using the non-conditional logistic regression model. Results: A total of 3 213 residents aged ≥35 years were included in this study, of which 11.48% (369/3 213) reported that they had ever been informed by a doctor or other health worker that their blood sugar level was high or being diabetic. The rate of self-reported treatment among the diabetic patients was 83.20% (307/369). Rates on overall management and standardized management were 69.92% (258/369) and 53.66% (198/369), respectively. Higher rates were seen in residents aged 55 to 64 years, 76.32% for overall management and 59.65% for standardized management. Through multiple logistic regression analysis, we found that standardized management for diabetes was much higher in the Demonstration Areas located in the eastern areas (OR=2.942, 95%CI: 1.547-5.594), or patients with characteristics including high implementation score (OR=3.499, 95%CI: 1.865-6.563), already signed family doctors (OR=5.661, 95%CI: 3.237-9.899), or without hypertension (OR=1.717, 95%CI: 1.010- 2.920). Residents who were living in the first and second batch areas of implementation or responding to the NCDs with positive attitude were more likely to accept standardized management. Conclusion: Prevention and management programs on diabetes had met the requirements set for the Demonstration Areas which had promoted the specific implementation and further development of standardized management on diabetes.

[Study on the overall implementation status of the National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases]

Objective: To understand the current overall status of implementation on the National Demonstration Areas of Comprehensive Prevention and Control of Non-communicable Diseases. Methods: According to the scheme design of the questionnaires, all the National Demonstration Areas were involved in this study. For each National Demonstration Areas, eight departments were selected to complete a total of 12 questionnaires. Results: Scores related to the implementation of the National Demonstration Areas accounted for 71.8% of the total 170 points. Based on the scores gathered from this study, the 23-items-index-system that represented the status of project implementation was classified into seven categories. Categories with higher percentile scores would include: monitoring (88.0%), safeguard measures (75.0%), health education and health promotion (75.0%). Categories with lower percentile scores would include: the national health lifestyle actions (67.7%), community diagnosis (66.7%), discovery and intervention of high-risk groups (64.7%), and patient management (60.9%). There were significant differences noticed among the eastern, central and western areas on items as safeguard measures, health education/promotion, discovery and intervention of high-risk groups. In all, the implementation programs in the eastern Demonstration Areas seemed better than in the central or western regions. As for the 23 items, five of the highest scores appeared on policy support, mortality surveillance, tumor registration, reporting system on cardiovascular/cerebrovascular events, and on tobacco control, respectively. However, the lowest five scores fell on healthy diet, patient self-management program, oral hygiene, setting up the demonstration units and promotion on basic public health services, respectively. The overall scores in the eastern region was higher than that in the central or the western regions. The scores in the central and western regions showed basically the same. Conclusions: The overall status of implementation on the National Demonstration Areas was satisfactory. Future attention should be focusing on patient management as well as discovery and intervention of high-risk groups, which also presented the lowest scores, in this survey.

Kawasaki disease in children: Epidemiology, clinical symptoms and diagnostics of 231 cases in 10 years

The present study was a retrospective analysis of the dynamic changes and clinical characteristics of 231 cases of Kawasaki disease (KD) in pediatric patients admitted to the People's Hospital of Inner Mongolia between January 2003 and December 2012. A total of 37.23% of the cases occurred in the first 5 years, compared with 62.77% in the latter 5 years. The age distribution ranged from 3 months to 10 years, with a peak age of <1 year. The male-to-female ratio was 2.12:1, and the reoccurrence rate was 1.3%. Among the patient cohort, 7.8% were Mongolian children. The most common clinical symptom was fever (87.6%), while perianal skin peeling was the most rare (14.1%). With regard to the analyzed biomarkers, 90.4% of patients had abnormal platelet (PLT) counts; the next highest abnormality rates were associated with erythrocyte sedimentation rate (ESR) (74.46%) and white blood cell (WBC) counts (59.74%), followed by levels of C-reactive protein (CRP) (57.58%), creatinine kinase-MB (40.26%) and hemoglobin (Hb) (38.53%). In conclusion, the present study has found that approximately two-thirds of cases of KD over a 10-year period occurred in the latter 5 years. Changes in a number of experimental indicators, including PLT, ESR and WBC, could be used in the diagnosis of the condition and to reflect the success of the clinical treatment.

[Relationship between heat stress suppression of neuroapoptosis and activation of nuclear kappa B in primary cultured rat cerebellar granule cells]

It has been well demonstrated that heat stress response (HSR) plays a crucial role in protecting cells from injury induced by various pathological stimuli. However, the protective mechanism of HSR is only poorly understood. The object of this article was to further investigate the relationship between the protective role of heat stress response and activation of NF-kappa B in primary cultured rat cerebellar granule cells. Heat stress was induced by hyperthermia (43+/-0.5 degrees centigrade), and DNA binding activity of NF-kappa B was determined with electrophoretic mobility shift assay (EMSA). Neuroapoptosis was measured by Hoechst 33258, agarose gel electrophoresis and flow cytometry (FCM) analysis. The results showed that the neurons treated with low potassium for l6 h could induce neuroapoptosis and promote the activity of nuclear kappa B. Heat stress treatment for 30, 60 and 90 min could suppress neuroapoptosis and the activity of nuclear kappa B induced by low potassium in a time-dependent manner. Activation of NF-kappa B using 100 nmol/L phorbol 12-myristate l3-acetate (PMA) could promote antiapoptotic action of heat stress response. In contrast, when NF-kappa B activation was inhibited by 10 micromol/L pyrrolidine dithiocarbamate derivatives (PDTC), heat stress did not provide protection against cell apoptosis induced by low potassium. The results suggest that the neuroprotection of heat stress has no relation to the suppression of NF-kappa B activity, and activation of NF-kappa B may promote antiapoptotic action of heat stress.

Antagonistic action of caffeine against LY294002-induced apoptosis in cerebellar granule neurons

AIM

To study the effect of caffeine on apoptosis induced by inhibition of 1-phosphatidylinositol 3-kinase in cerebellar granule neurons.

METHODS

Cerebellar granule neurons culture, agar gel electrophoresis, and stress-activated protein kinase (SAPK)/c-Jun N-terminal protein kinase (JNK) assay kit to measure SAPK/JNK activity.

RESULTS

LY294002 evoked apoptosis concentration-dependently in cerebellar granule neurons. But death resulting from LY294002 was prevented by caffeine in a concentration-dependent manner. The survival effect of caffeine was not affected by inhibitors of ryanodine-sensitive Ca2+ release, nor was it inhibited by L-type channel blockers and N-methyl-D-aspartate (NMDA) receptor blocker. In addition, RP-cAMP, H89, and KN62 were not able to inhibit the protective effect of caffeine. Phosphorylation of c-Jun was necessary for the induction of apoptosis induced by LY294002 in cerebellar granule neurons. But caffeine directly inhibited the activation of JNK and decreased phospho-c-Jun in granule neurons.

CONCLUSION

Caffeine inhibited the activation of JNK and decreased the phosphorylation of c-Jun to protect granule neurons from LY294002-induced apoptosis.

Morphological behaviour of osteoblasts on diamond-like carbon coating and amorphous C-N film in organ culture

Similar to diamond-like carbon (DLC) coating, amorphous carbon nitride (C-N) films can be extremely hard and wear-resistant. They may serve as candidates for the solution to the problem of aseptic loosening of total hip replacements. Morphological behaviour of osteoblasts on silicon, DLC-coated silicon and amorphous C-N film-deposited silicon in organ culture was investigated by scanning electron microscopy. Cells on the silicon wafers were able to attach, but were unable to follow this attachment with spreading. In contrast, the cells attached, spread and proliferated on the DLC coatings and amorphous C-N films without apparent impairment of cell physiology. The morphological development of cells on the coatings and films was similar to that of cells in the control. The preliminary results support the biocompatibility of DLC coating and are encouraging for the potential biomedical applications of amorphous C-N film.

Microstructure and micromechanical properties of the mid-diaphyses of human fetal femurs

The microstructure, composition and the micromechanical properties across the thickness of femoral mid-diaphyses from 14 to 26 week human fetuses have been investigated. Scanning electron microscopy and transmission electron microscopy were employed to examine structural changes with maturation. The fetal bones consist of layers of woven bone. From young to old fetuses and from outer to inner bone layers, the collagen fibrils become more cross-linked, densely packed and change from disordered to an ordered arrangement. The collagen fibril bundles are also more preferentially oriented and change from a chiefly circumferential to longitudinal direction. The sizes of the apatite crystals also increase with age. The Ca/P ratio remains constant around 1.55 for all the bone layers except the outmost layer which is lower than 1.2. An nano-indenter was used to evaluate the microhardness and elastic modulus of each bone layer. The increase of microhardness and elastic modulus correlates with the maturation of bone. The mechanical properties of the mid-diaphyses of human fetal femurs are anisotropic, which is due to the preferential orientation of collagen fibrils.

Microstructures of external periosteal callus of repaired femoral fracture in children

In order to understand further the mechanism of bone fracture repair, and thus to innovate better operative treatment for bone fracture and to design new implant materials for bone repair, microstructures of external periosteal callus (EPC) of repaired femoral fracture in both children and adults were investigated by using a scanning electron microscope, transmission electron microscopy, and an X-ray microdiffractometer. The repair time after the fractures in children and adults is on average 155 and 370 days, respectively. Collagen fibrils making up children's EPC (CEPC) are underdeveloped and insufficiently mineralized by hydroxyapatite (HA), while those from adults' EPC (AEPC) are similar to normal bone. A lot of particles loaded by brushite (DCPD) minerals were found among the collagen fibrils of CEPC. The main mineral phases in CEPC consist of DCPD and HA, while only HA exists in AEPC. Deposition of DCPD minerals could have compensated for the insufficient mineralization of the collagen fibrils of CEPC, thereby making fractured bone repair more rapidly in children than in adults.