OBJECTIVES: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China. METHODS: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (n=1 189) and non-EUGR (n=1 325). The clinical features were compared between the two groups, and the incidence of EUGR and risk factors for EUGR were examined. RESULTS: The incidence of EUGR was 47.30% (1 189/2 514) evaluated by weight. The multivariate logistic regression analysis showed that higher weight growth velocity after regaining birth weight and higher cumulative calorie intake during the first week of hospitalization were protective factors against EUGR (P<0.05), while small-for-gestational-age birth, prolonged time to the initiation of total enteral feeding, prolonged cumulative fasting time, lower breast milk intake before starting human milk fortifiers, prolonged time to the initiation of full fortified feeding, and moderate-to-severe bronchopulmonary dysplasia were risk factors for EUGR (P<0.05). CONCLUSIONS It is crucial to reduce the incidence of EUGR by achieving total enteral feeding as early as possible, strengthening breastfeeding, increasing calorie intake in the first week after birth, improving the velocity of weight gain, and preventing moderate-severe bronchopulmonary dysplasia in VPIs.
Female ; Fetal Growth Retardation ; Gestational Age ; Hospitalization ; Humans ; Incidence ; Infant ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Prospective Studies ; Risk Factors

Objective To investigate the presence and genetic background of 16S rRNA methylase gene and Aminoglycoside modifying enzymes(AMEs) genes in Klebsiella pneumoniae isolated from the People's Liberation Army 98th HospitaI,Huzhou district,Zhejiang province,China.Methods 25 strains of Klebsiella pneumoniae were isolated from the inpatienta between September,2005 and April,2006.6 kinds of 16S rRNA methylase gene (including armA,rmtA,rmtB,rmtC,rmtD and npmA ),6 kinds of AMEs genes [ including aac (3)-Ⅰ,sac (3)-Ⅱ,sac (6')-Ⅰ,aac (6')-Ⅱ,ant (3")-Ⅰand ant(2")-Ⅰ],intI1,intI2,intI3,mercuric reductase gene merA (merA gene were the collective genetic markers of transposona of Tn21 and Tn501 ) and tnpA ( tnpA gene were the collective genetic markers of transposons of Tn1,Tn2,Tn3 and Tn1000) were analyzed by PCR and verificated by DNA sequencing.Results In 25 strains of Klebsiella pneumoniae,the positive rate of genes of rmtB,sac (3)-Ⅱ,sac (6')-Ⅰ,ant(3")-Ⅰ and intI1 were 60.0%(15/25),4.0%(1/25),48.0%(12/25),60.0%(15/25) and 96.0%(24/25),respectively.The rest 12 kinds of genes were all tested negative.The total positive rate of 6 kinds of AMEs gene was 84.0%(21/25).Conclusion There were very high positive rate on both genes of rmtB and AMEs genotypes in Klebsiella pneumoniae isolated from inpatients,and this was the first report of the emergence of 16S rRNA methylase gene rmtB in Klebsiella pneumoniae identified in Zhejiang province,China.

AIMTo study the characteristics of neural information encoding of the epileptic networks involved caudate-putamen(CPu) and the hippocampi induced by tetanization of the right CPu in rats.

METHODSExperiments were performed on 59 SD rats. Acute or chronic tetanization of the right CPu (ATRC or CTRC) (60Hz,0.4-0.6 mA, 2 s) was used to induce rat epilepsy.

RESULTS(1) The bursting or primary unit afterdischarges of single neurons were asymmetric in dual hippocampi induced by the ATRC. (2) Continuous sharp waves were observed in ipsilateral or contralateral CPu induced by the CTRC. The oscillatory network seizures with phase shift appeared between two sharp waves in ipsilateral CPu. The frequency of oscillatory waves was negatively correlated with the time and fluctuated from 70 Hz to 110 Hz, then to 35 Hz, and finally to 30 Hz. (3) In the contralateral side primary network after discharges in the CPu were induced by the CTRC. Therefore, the characteristic primary network afterdischarges could be shifted from the CPu or to the HPC, but amplified. On the other hand, HPC sharp waves could be depressed when the CPu network seizures occurred.

CONCLUSIONThe reestablishment of CPu-hippocampal epileptic networks could be transhemispherically promoted by over-activation of the right CPu network, in which bilateral hippocampal neuronal network and CPu neural network were involved in some particular pathophysiological information encoding.

Animals ; Caudate Nucleus ; metabolism ; Epilepsy ; physiopathology ; Hippocampus ; metabolism ; Male ; Neurons ; metabolism ; Putamen ; metabolism ; Rats ; Rats, Sprague-Dawley

AIMTo investigate the regulatory network of hippocampal-systemic arterial blood pressure during epileptic network reestablishment.

METHODS7.2 microg picrotoxin (PTX) was microinjected into the right HPC (RHPC) to induce rat epilepsy. Contralateral hippocampal EEG, single unit discharges, femoral artery blood pressure and ECG were recorded simultaneously.

RESULTSPTX might induce: (1) A resemblance interspike intervals (ISI) spot distribution of long duration neuronal burst and unit after discharges in contralateral HPC. (2) Delayed the initiation time of hippocampal neuronal bursts coupled with arterial blood pressure depression. (3) Hippocampal neuronal burst or unit after discharges coupled complexly with arterial blood pressure depression. (4) Resemblance hippocampal EEG interpeak intervals (IPI) and neuronal firing ISI spot distribution coupled with arterial blood pressure depression.

CONCLUSIONDuring contralateral hippocampal epileptic network reestablishment after microinjection of PTX to the RHPC, the function of the hippocampal-arterial blood pressure regulatory network could be modulated by characteristic network and neuronal temporal code patterning.

Animals ; Blood Pressure ; physiology ; Electrocardiography ; Electroencephalography ; Epilepsy ; physiopathology ; Hippocampus ; physiology ; physiopathology ; Male ; Rats ; Rats, Sprague-Dawley

The purpose of the present work was to study the effect of acute tetanization of the right caudate putamen nucleus (ATRC) on single neuronal interspike intervals (ISIs) in both laterodorsal thalamic nuclei (LDi), and electroencephalogram (EEG) wave interpeak intervals (IPIs) in both hippocampi (HPCi). Experiments were performed on 21 male Sprague-Dawley rats weighing 150~250 g. The seizures were induced by the ATRC (60 Hz, 2 s, 0.4~0.6 mA). Quadruple recordings were simultaneously carried out: two for single unit recordings from both LDi, and two for EEG recordings from both HPCi. The ATRC induced: (1) An interactive epileptic electrical network reconstructed in bilateral HPCi, which was driven by primary afterdischarges of single LD neuron. (2) A symmetric mirror-like ISI spot distribution of the LD neuronal firing before and after tetanus. (3) Gradually prolonged LD neuronal discharge intermittence was coherent with synchronous hippocampal EEG activities on the contralateral side. (4) Single LD neuronal spikes were phase- and time-locked to 20~25 Hz gamma oscillations in contralateral HPC. It suggests a particular temporal code patterning of single LD neuronal firing and its relationships to hippocampal EEG wave code in time series, the latter implies the LD neuronal encoding mechanisms of ATRC-induced epileptic electrical network in bilateral HPCi.
Action Potentials ; physiology ; Animals ; Caudate Nucleus ; physiology ; Electric Stimulation ; methods ; Electroencephalography ; Epilepsy ; etiology ; physiopathology ; Hippocampus ; physiology ; Lateral Thalamic Nuclei ; physiology ; Male ; Nerve Net ; physiology ; Neurons ; physiology ; Rats ; Rats, Sprague-Dawley ; Reaction Time ; physiology

The purpose of the present work was to study hippocampal cellular electrophysiology involved in cortical epileptic networks reorganized by acute tetanization (60 Hz, 2 s, 0.4-0.6 mA) of the right posterior dorsal hippocampus (ATPDH). Experiments were performed on 35 adult male Sprague-Dawley rats. The ATPDH was used to establish epilepsy model. Four-channel recordings were done simultaneously, two channels for single unit recordings from bilateral hippocampi and other two channels for electrocorticogram (ECoG) or hippocampal electroencephalogram (EEG) recordings on the bilateral sides. The ATPDH bilaterally induced: (1) Epileptic ECoG activities that were originated from single unit afterdischarges of ipsilateral hippocampal neuron, followed by single unit afterdischarges of contralateral hippocampal neuron, finally produced seizure-like oscillations in the contralateral and ipsilateral ECoG. (2) 4-10 Hz rhythmic ECoG oscillations and 100-250 Hz hippocampal EEG oscillations, and asymmetric electrical activities of bilateral hippocampal neurons. (3) The hippocampal neuronal bursting that appeared its interspike interval (ISI) spot distribution in an irregular circular shape. The ipsilateral circular shape ISI distribution was more regular and occurred often, which was time-locked with the sinusoidal pattern of maximum peaks of hippocampal oscillatory trains. The results imply that the epileptic networks are reorganized bilaterally between ECoG and hippocarnpal EEG by the ATPDH. The hippocampal neuronal firing temporally encodes its information, in particular, the irregular circular shape ISI distribution during epileptic network reorganization.

AIMTo investigate the neural network and cellular mechanisms of hippocampal epileptogenesis contralateral or ipsilateral to the side of acute tetanization (60 Hz, 2 s, 0.4 - 0.6 mA) of the posterior dorsal hippocampus (ATPDH).

METHODS10 trains of the ATPDH were administered into the CA1 basal dendritic region of the right hemisphere at an interval of 10 minutes.

RESULTS(1) The firing rate of CA1 single neuron in the right or the left hippocampus was inhibited respectively after the ATPDH, and the effects weakened gradually while the trains of the ATPDH increased. The inhibited firing rate and the transformed firing pattern from tonic one to clonic one were more obvious at the side contralateral to the stimulation (62.94% +/- 3.68%, 36.61% +/- 3.14%, P < 0.01). (2) Synchronous primary afterdischarges of depth EEG and single unit discharges were more commonly observed at the side ipsilateral to the ATPDH (P < 0.01). (3) Primary or secondary hippocampal network afterdischarges at high frequency were only found in CA1 region ipsilateral to the ATPDH. (4) Secondary afterdischarges of CA3 basal dendritic neural network were completely synchronized with those of subicular single neuron, which reoccurred and persisted several hours.

CONCLUSIONIt is possible that post-inhibition bursting of single neuron and recurrent network seizures in the hippocampus contralateral to the artificial focus be the important manifestation of the formation of "epileptic networks" across from one hemisphere to another.

Animals ; Electric Stimulation ; Hippocampus ; physiology ; Male ; Neural Pathways ; physiology ; Rats ; Rats, Sprague-Dawley ; Seizures ; etiology

AIMThe electrographic and behavioral kindling effects were induced by chronic tetanization of the right caudate-putamen (CPu) to study the target-behavior expression involved in the CPu or hippocampus (HPC) network abnormalities.

METHODSExperiments were performed on 58 SD rats. Tetanization (60Hz,0.4 - 0.6mA, 2s) was delivered into the CPu or the HPC, once a day, for 7-12 days. Animal behaviors were observed every day and depth electrographs were recorded at the beginning or at the end of the experiments.

RESULTSChronic tetanization of the CPu or of the HPC induced: (1) Rhythmic sharp waves in the CPu and paroxysmal epileptiform events in the HPC electrographs. (2) Primary behavioral seizures, secondary behavioral seizures, and kindling effects, including wet dog shakes (WEDS), rearing, face washing, immobility, chewing and head nodding. (3) Lower rate of primary WEDS (P < 0.01), and higher rate of secondary WEDS (P < 0.01) in the CPu-tetanized rats. (4) Longer silent period of behavioral seizures before kindling appeared in the CPu-tetanized rats.

CONCLUSIONKindling effects in the CPu-tetanized rats resembles those in the HPC-tetanized rats. The CPu might participate in the origin of epileptic focus and be involved in reestablishment of limbic epileptic networks, which may be responsible for the target-behavioral seizures.

Animals ; Behavior, Animal ; Caudate Nucleus ; Electric Stimulation ; Epilepsy ; physiopathology ; Kindling, Neurologic ; Male ; Rats ; Rats, Sprague-Dawley ; Seizures ; physiopathology

The purpose of the present work was to study the role of unilateral hippocampal neural network in hippocampal epileptogenesis and its cellular mechanisms. Experiments were performed on 45 Sprague-Dawley adult rats. Acute tetanization (60 Hz, 2 s, 0.4 - 0.6 mA) of the right posterior dorsal hippocampus (ATPDH) was used to induce hippocampal epilepsy. The single unit discharges and the depth electrographs were synchronously recorded with a glass microelectrode and a pair of stainless concentric electrodes in the ipsilateral anterior dorsal hippocampus (HPC). The results demonstrated that: (1) some primary unit after-discharges were synchronized with electrographic after-discharges in the anterior dorsal HPC network after eight or nine tetanic trains were administered. Others desynchronized with 5 - 90 Hz primary depth electrographic after-discharges; (2) primary electrographic after-discharges were driven by primary unit after-discharges in the anterior dorsal HPC; (3) primary unit after-discharges were induced by brief primary electrographic after-discharges; and (4) plasticity of primary electrographic after-discharges and inhibition of single neuron firing were induced by repetitive ATPDH. The results suggest that hippocampal pathophysiologic network along the temporal-septal axis of the HPC is re-established by the repetitive ATPDH. There are plastic interactions between single neurons and its network during this re-establishment, which may be involved in the generation of "seizure oscillation". Over-activation of an intrinsic inhibition of the HPC along its temporal-septal axis might be involved in hippocampal network epileptogenesis.
Animals ; Electric Stimulation ; Epilepsy, Temporal Lobe ; physiopathology ; Evoked Potentials ; Hippocampus ; physiopathology ; Male ; Nerve Net ; physiopathology ; Neurons ; physiology ; Rats ; Rats, Sprague-Dawley

The purpose of this work was to study the characteristics of rat brain abnormalities at two hemispheres at the early stage of electrogenic epilepsy. Experiments were performed on 37 male Sprague-Dawley rats. Chronically repetitive tetanization (60 Hz, 2 s, 0.4 - 0.6 mA) was used to stimulate the right dorsal hippocampus (DHPC) of the rat brain once a day for 2, 4, 6, 8 or 10 d, respectively. The T(2) weighted magnetic resonance image (T(2)-WI) were obtained from each experimental rat at the end of the experiments. Histological sections were obtained after experimentation. The results showed that the main pathologic changes at the early stage of epilepsy included: (1) T(2)-WI hyperintensification, the histological enlargement of lateral ventricle (LV) and pathological hyperplasia of ventricular choroidea plexus occurred. The pathological hyperplasia was symmetric in two hemispheres, but the LV enlargement was not. (2) Histologically enlarged LV area showed a resemblance to T(2)-WI hyperintensive area. Compared with the control rats, large T(2)-WI hyperintensive area (P=0.0259; P=0.0184; P=0.0184; P=0.0404; P=0.0259) and histologically enlarged LV area (P=0.0210; P=0.01; P=0.0100; P=0.0152) were present in chronically tetanized rats. (3) Dynamic characteristics of histologically enlarged LV area resembled to those of T(2)-WI hyperintensity area in chronically tetanized rats at different stimulating day. Lateralization of T(2)-WI hyperintensity was in accordance with that of T(2)-WI abnormal area and of histologically enlarged LV. These abnormalities were severe on the contralateral side on the stimulating day 6, or on the ipsilateral side on the stimulating day 10. These results imply characteristic propagation of brain abnormalities crossing to the opposite hemisphere at the early stage of an electrogenic rat epilepsy.
Animals ; Cerebral Cortex ; pathology ; physiopathology ; Electric Stimulation ; Epilepsy ; etiology ; pathology ; physiopathology ; Hippocampus ; physiopathology ; Magnetic Resonance Imaging ; Male ; Rats ; Rats, Sprague-Dawley ; Time Factors