[Experimental study on developmental changes of synaptic currents in V1B cortical layer Ⅳ pyramidal neurons in C57BL/6J mice]

Objective: To investigate the developmental changes of miniature excitatory and inhibitory postsynaptic currents (mEPSCs and mIPSCs) of layer Ⅳ pyramidal neurons in the primary visual cortex binocular zone (V1B) of C57BL/6J wild-type mice at different developmental stages. Methods: Sixteen male C57BL/6J mice of specific-pathogen-free grade were selected and divided into 4 groups according to their postnatal age: P14 group (before and after eye opening), P28 group (the peak of the critical period), P35 group (the end of the critical period), and P130 group (fully adult). Whole-cell patch-clamp technique was used to record the frequency and amplitude of mEPSCs and mIPSCs of layer Ⅳ pyramidal neurons in V1B of each group, and to analyze their differences and changes. Results: The frequency of mEPSCs of layer Ⅳ pyramidal neurons in V1B of mice in the four groups was statistically different (F=9.46, P<0.001), with the P35 group being higher than the P28 group [P28 and P35 groups were (8.72±1.34) and (13.28±4.05) Hz, t=3.39, P=0.012], and the P130 group being lower than the P35 group [P35 and P130 groups were (13.28±4.05) and (5.82±1.98) Hz, t=5.21, P<0.001]; the amplitude of mEPSCs of layer Ⅳ pyramidal neurons in V1B of mice in the four groups was not statistically different (F=2.84, P=0.055). The frequency of mIPSCs of layer Ⅳ pyramidal neurons in V1B of mice in the four groups was statistically different (F=8.14, P<0.001), with the P130 group being higher than the P14 group [P14 and P130 groups were (5.22±1.33) and (12.03±3.94) Hz, t=4.678, P<0.001]; the amplitude of mIPSCs of layer Ⅳ pyramidal neurons in V1B of mice in the four groups was statistically different (F=7.06, P=0.001), with the P35 group being higher than the P28 group [P28 and P35 groups were (20.07±3.56) and (28.47±5.98) pA, t=3.66, P=0.006], and the P130 group being lower than the P35 group [P35 and P130 groups were (28.47±5.98) and (20.32±3.55) pA, t=3.33, P=0.014]. Conclusions: The excitatory synaptic development of layer Ⅳ pyramidal neurons in V1B of mice is in a vigorous growth state during development and gradually weakens with age, while the inhibitory synaptic development gradually strengthens with increasing postnatal age, and both of them rapidly develop during the critical period.

[Epidemiological and pathogenic features of a bacillary dysentery outbreak in a boarding school caused by Shigella sonneri]

Objective: To investigate the etiologic and epidemiologic features of an infectious diarrhea outbreak in a boarding school in Fuyang city, Anhui province. Methods: Traceability hypothesis of this study was tested according to the epidemiological characteristics of the cases. Feces, anal swabs, water samples and food residues related to the patients and chefs were collected for pathogen isolation and detection. Biochemical identification, virulence gene detection, drug susceptibility test, PFGE and multilocus sequence typing were performed. Results: The incidence rate (3.41%) of different dormitory buildings within the water supply area by shallow wells was higher than that (0.98%) of the deep wells, with statistical significance (χ(2)=17.215, P<0.001). Sixteen strains belonged to the Shigella Sonneri family were isolated from the patient's samples, and all carrying the ipaH gene. Seven strains belonged to sen and ial genes. Set1 gene that did not appear in all the 16 strains were highly resistant to ampicillin, tetracycline, compound xinnomine, cefazoline, cefotaxime, gentamicin, naphthidinic acid and streptomycin, including 9 strains to doxycycline. The pulse field pattern of the 16 strains of Shigella sonneri appeared the same, with the ST type as ST152. Conclusion: When combined data from the etiological and epidemiological investigation, it was confirmed that Shigella sonneri was the pathogen of this outbreak, and water from the shallow wells might be responsible for the source of infection.

[Serological study on inhibitory function of shenkang injection on glomerular mesangial cell]

OBJECTIVE

To explore the intensity of inhibitory function of Shenkang injection (SKI), a Chinese herbal recipe, and benazepril on the proliferation of human glomerular mesangial cell (MC).

METHODS

The effect of SKI and benazepril on the proliferation of human MC was observed by using the cultured MC in vitro and serum pharmacological assay.

RESULTS

Both SKI and benazepril could inhibit the proliferation of human MC, but in equal dosage consistency, SKI showed a better inhibitory effect than that of benazepril.

CONCLUSION

MC is the important target cell for the action of SKI, the inhibiting on proliferation might be one of the essential mechanisms of SKI in retarding glomerulosclerosis.