The effect of zinc on the damage of primary cultured hippocampal neurons induced by corticosterone (CORT) was studied. Neuronal injury and expression of NMDA receptor subunits (NR1,NR2A,NR2B) mRNA were detected by using in situ staining and RT-PCR, respectively. Neurons treated with 5 micromol/L CORT for 24 h showed decreased survival rates and increased apoptotic rates compared with the controls; co-application of CORT and 10 or 100 micromol/L Zn(2+) attenuated apoptotic rates while 250 micromol/L Zn(2+) worsened CORT-induced neuronal injury. Expression of NR1, NR2B mRNA in neurons treated by 5 micromol/L CORT for 24 h was significantly increased, while those concurrently added with 10 or 100 micromol/L Zn(2+) showed no changes. No statistic difference in NR2A mRNA was obtained under any treatment. These results suggest that zinc can bilaterally regulate neuronal injuries induced by CORT, among while NMDA receptors probably play an important role.
Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Cells, Cultured ; Corticosterone ; pharmacology ; Hippocampus ; pathology ; Neurons ; pathology ; Neuroprotective Agents ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Receptors, N-Methyl-D-Aspartate ; biosynthesis ; classification ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Zinc ; pharmacology

OBJECTIVETo explore the regulatory effect of arginine on the secretion of hepatic insulin-like growth factor-1 (IGF-I), and the mechanism of enhancing the immune function by arginine.

METHODSWistar rats were randomly divided into normal control (NC), wound control (WC), and wound with arginine (Arg) groups, with 8 rats in each group. The rats in WC and Arg groups were inflicted with soft tissue trauma on the back. The rats in Arg group were fed a diet supplemented with 5% arginine for one week, while those in NC and WC groups were fed with glycine. The serum contents of arginine, ornithine, growth factor (GH), NO and IGF-I were determined 7 days after feeding. T cell proliferation and IGF-I mRNA expression in hepatic tissue were also measured. Meanwhile, the rat hepatocytes were cultured in serum-free medium containing different concentrations of arginine. The supernatant was collected for the determination of IGF-I level.

RESULTS1). There was no obvious difference of the serum level of arginine and ornithine between NC and WC groups (P > 0.05), but the contents of them were obviously higher in the Arg group compared with other two groups (P < 0.01). 2). No difference in the serum GH level was found among all the groups (P > 0.05), but the serum NO content in WC and Arg groups was significantly lower than that in NC group (P < 0.01), and the serum IGF-I content in WC group decreased obviously compared with that in NC group (P < 0.01). 3). The thymocyte proliferation rate in WC group was also markedly lower than that in NC group (P < 0.01), but that in Arg group was improved compared with WC group (P < 0.01). 4). The expression of hepatic IGF-I mRNA: The relative value of IGF-I mRNA was 1.19 +/- 0.06, 1.08 +/- 0.06 and 1.29 +/- 0.06 in NC, WC and Arg, respectively, while the value in WC was lower than that in NC (P < 0.05) group, and that in Arg group was much higher than that in WC group (P < 0.01). 5). The IGF-I level in the supernatant of cultured hepatocytes: When Arg concentration was 0.0750, 0.7500, 7.5000 mmol/L in the culture medium, the IGF-I level in the supernatant of hepatic cell medi-um was obviously higher than that in the medium without arginine (P < 0.01). Although IGF-I level decreased in the culture medium with arginine in the dose of 37.5000 mmol/L, it was still obviously higher than that in the medium without arginine (P < 0.01).

CONCLUSIONArginine could also produce the immune enhancing effect by stimulating hepatic IGF-I secretion.

Animals ; Arginine ; pharmacology ; Enteral Nutrition ; Insulin-Like Growth Factor I ; metabolism ; Liver ; drug effects ; secretion ; Male ; Rats ; Rats, Wistar ; Soft Tissue Injuries ; metabolism ; therapy

OBJECTIVETo study the aerodynamics of the normal human nasal cavity under different ambient temperatures.

METHODSBased on CT scanning, a model of a healthy adult's nasal cavity was established using computational fluid dynamics software from Fluent. Airflow in this model was simulated and calculated at ambient temperatures of 0 °C, 24 °C, and 37 °C during periodic breathing.

RESULTSAmbient temperature only had an impact on the temperature in the nasal cavity during the inspiratory phase, and the temperature distribution was not symmetrical in the inspiratory acceleration and deceleration phases. The ambient temperature significantly affected airflow speed in main nasal passages during the inspiratory process, but had little impact on flow status (proportion and streamline of airflow in different nasal passages). Temperature differences increased the irregular air movement within sinuses. The anterior nasal segment, including the area between the valve and the head of the middle turbinate, was the most effective part of the nasal airway in heating the ambient air.

CONCLUSIONSOur findings describe the effects of ambient temperature on airflow parameters in the nasal cavity within a single respiratory cycle. This data is more comprehensively and accurately to determine the relationship between nasal cavity aerodynamics and physiological functions.

Adult ; Air Movements ; Female ; Humans ; Models, Theoretical ; Nasal Cavity ; physiology ; Temperature

AIMTo observe the effects of stress on Glu uptake and NMDAR of hippocampus synaptosome in rats with different zinc status.

METHODSStress model was established by photoelectric stimulus. The behaviors of rats were tested in open-field case. 3H-L-Glu was taken as radioligand to detect the NMDAR binding. Glu uptake was determined with radioimmunoassay.

RESULTSCompared with CT rats, ZD rats performed less movement in open-field test, both Bmax of NMDAR and 3H-L-Glu uptake of hippocampus in these rats were significantly decreased. Compared with corresponding non-stressed groups, the stressed groups appeared longer latency and less movement in open-field test. Increased Bmax of NMDAR and decreased 3H-L-Glu uptake were observed in all stressed rats, but only in SZD rats these indices showed statistical difference.

CONCLUSIONAbnormal behaviors of rats induced by photoelectric stress were observed in open-field test, which was more serious in zinc deficiency rats. It is supposed that the Glu-NMDAR pathway is involved in the process of stress reaction. As it shows in our experiment, the changes of Bmax of NMDAR and 3H-L-Glu uptake of hippocampus synaptosome seems to be a part of the mechanisms of stress action.

Animals ; Glutamic Acid ; metabolism ; Hippocampus ; drug effects ; metabolism ; Male ; Rats ; Rats, Wistar ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Stress, Physiological ; Zinc ; pharmacology

OBJECTIVETo compare the characteristics of normal nasal airflow during periodic breathing and steady-state breathing.

METHODSFluent software was used to simulate the nasal cavity and paranasal sinus structures following CT scanning of a normal adult subject. Air flow velocity, pressure, distribution and streamlines were calculated and compared during periodic breathing and steady-state breathing.

RESULTSThe same flux, the performance of nasal airflow on 15.600 s of periodic breathing and steady-state expiratory (entrance flow was 697.25 ml/s) were as follows: air flow in the common and middle meatus accounted for more than 50% and 30% of total nasal cavity flow during two respiratory status. Flow velocity and pressure of nasal cavity and each paranasal sinus were extremely similar. The flow trace during two respiratory status in the inferior and lower part of the common meatus were predominately straight in form.Flow were parabolic in the middle and superior meatus and the middle and upper parts of the common meatus. The flow trace of nasal airflow on 16.495 s of periodic breathing had wide areas vortex in nasopharynx and limen nasi, the average speed was 0.0706 m/s, while the entrance flow 7.62 ml/s stable state of the left nasal expiratory, the average speed was 0.0415 m/s, the flow trace was similar to 697.25 ml/s.

CONCLUSIONThe same flow, except in the junction of the respiratory cycle, the performance of normal nasal airflow during periodic breathing and steady-state breathing were similar.

Adult ; Female ; Humans ; Nasal Cavity ; physiology ; Respiration ; Respiratory Mechanics ; Tomography Scanners, X-Ray Computed

Small intestinal hemangioma is a rare condition that can be divided histologically into capillary, cavernous or mixed types, among which the cavernous type is the most common. Here we report a case of small intestinal cavernous hemangioma with chronic hemorrhage in 44-year-old man. The patient complained of weakness and dizziness for 2 years that aggravated 1 month before admission accompanied by intermittent melena. Laboratory tests suggest severe anemia, and computed tomography, gastroscopy and colonoscopy all revealed signs of anemia. Capsule endoscopy detected small intestinal erosions, bleeding lesions and prominent neoplasms. An exploratory laparotomy was performed, in which the segment of the jejunum with lesions was resected. Pathological examination of the resected jejunum identified the neoplasm as cavernous hemangioma of the small intestine, which was the cause of severe anemia.

BACKGROUNDStreptococcus pneumoniae (S. pneumoniae) is a major causative agent of severe infections, including sepsis, pneumonia, meningitis, and otitis media, and has become a major public health concern. We report the pneumococcal serotype and sequence type (ST) distribution, and antimicrobial resistance of 39 S. pneumoniae strains from seven hospitals in China.

METHODSBlood/cerebrospinal fluid (CSF) and sputum isolates from patients were analyzed to determine S. pneumoniae serotypes by polymerase chain reaction (PCR) and the Neufeld Quellung reaction, the multilocus sequence types (MLST) by PCR and sequencing, and susceptibility to antimicrobial agents by the VITEK Gram Positive Susceptibility Card.

RESULTSA total of 39 isolates were collected including 21 blood/CSF and 18 sputum isolates. Conventional serotyping by the Quellung reaction required 749 reactions. In contrast, PCR based typing needed only 106 PCR reactions. The most frequent serotypes from the blood/CSF isolates were 14 (38.1%), 19A (14.3%), 23F (9.5%), and 18C (9.5%). In the sputum isolates the most frequent serotypes were 19F (33.3%), 23F (16.7%), 19A (11.1%), and 3 (11.1%). The incidence of penicillin resistance in the blood/CSF and sputum isolates was 66.7% and 55.6%, respectively. Statistical analysis showed that patients = 5 years old had a higher resistance to penicillin when they compared with the patients = 65 years old (P = 0.011). Serotypes 14, 19A and 19F were significantly associated with penicillin resistance (P < 0.001). ST320, ST271, and ST876 isolates showed high resistant rates to several antibiotics including penicillin (P = 0.006). All of the isolates of serotype 19A were resistant to both penicillin and erythromycin, and they were all multi-drug resistant (MDR) isolates.

CONCLUSIONSThe specificity and sensitivity of multiplex-PCR are good, and this method represents a substantial savings of time and money, and can be widely used in the laboratory and clinical practice. Data from this research showed an extremely high prevalence of penicillin resistance and an increasing prevalence of multi-drug resistant (MDR) rate in S. pneumoniae. A distinctive emergence of serotype 19A was observed which was also associated with the increasing prevalence of antimicrobial resistance. Therefore, nationwide surveillance of pneumococcal resistance and serotypes is strongly warranted.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Drug Resistance, Multiple, Bacterial ; Humans ; Infant ; Microbial Sensitivity Tests ; Middle Aged ; Molecular Typing ; methods ; Multilocus Sequence Typing ; methods ; Pneumococcal Infections ; microbiology ; Serotyping ; Streptococcus pneumoniae ; classification ; drug effects

BACKGROUNDStaphylococcus aureus (S. aureus) remains as an important microbial pathogen resulting in community and nosocomial acquired infections with significant morbidity and mortality. Few reports for S. aureus in lower respiratory tract infections (LRTIs) have been documented. The aim of this study was to explore the molecular epidemiology of S. aureus in LRTIs in China.

METHODSA multicenter study of the molecular epidemiology of S. aureus in LRTIs was conducted in 21 hospitals in Beijing, Shanghai and twelve other provinces from November 2007 to February 2009. All the collected S. aureus strains were classified as minimum inhibitory concentration (MIC), mecA gene, virulence genes Panton-Valentine Leukocidin (PVL) and γ-hemolysin (hlg), staphylococcal cassette chromosome mec (SCCmec) type, agr type, and Multilocus Sequence Typing (MLST).

RESULTSTotally, nine methicillin-sensitive S. aureus (MSSA) and 29 methicillin-resistant S. aureus (MRSA) strains were isolated after culture from a total of 2829 sputums or bronchoalveolar lavages. The majority of MRSA strains (22/29) had a MIC value of ≥ 512 µg/ml for cefoxitin. The mecA gene acting as the conservative gene was carried by all MRSA strains. PVL genes were detected in only one S. aureus strain (2.63%, 1/38). The hlg gene was detected in almost the all S. aureus (100% in MSSA and 96.56% in MRSA strains). About 75.86% of MRSA strains carried SCCmec III. Agr type 1 was predominant (78.95%) among the identified three agr types (agr types 1, 2, and 3). Totally, ten sequence type (ST) of S. aureus strains were detected. A new sequence type (ST1445) was found besides confirming ST239 as the major sequence type (60.53%). A dendrogram generated from our own MLST database showed all the bootstrap values ≤ 50%.

CONCLUSIONOur preliminary epidemiology data show SCCmec III, ST239 and agr type 1 of S. aureus as the predominant strains in LRTIs in Mainland of China.

Alleles ; Anti-Bacterial Agents ; therapeutic use ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Humans ; Microbial Sensitivity Tests ; Prospective Studies ; Respiratory Tract Infections ; epidemiology ; Staphylococcal Infections ; epidemiology ; Staphylococcus aureus ; drug effects ; pathogenicity

Objective:To discuss the problems existing in the implementation of the Chinese health industry standard WS 523-2019 by testing SPECT device.Methods:Under the WS 523-2019 standards, a total of 10 SPECT devices were tested with regard to their SPECT reconstructed spatial resolution (SRSR), system planar sensitivity (SPS), system spatial resolution (SSR), whole body system spatial resolution (WSSR), intrinsic uniformity (IU), intrinsic count rate performance (ICR), intrinsic spatial resolution (ISR) and intrinsic spatial linearity(ISL).Result:Under the requirements of WS 523-2019 standards for qualified limits, there are 3 devices with ISL unqualified and the rest of the performances qualified. The new standards basically can meet the clinical requirements and reflected the overall performance of SPECT.Conclusions:The distance between the radiation source and the surface of the detector has great influence on the spatial resolution.In the measurement of ISL, there must be a lead grid separately in the x and y directions. The lead grids with the parallel slits shall be positioned on the detector with the center slit centered on the detector. It is suggested to add rotation center in the new standards.

BACKGROUNDAcinetobacter baumanii (A. baumanii ) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs).

METHODSTwo thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods.

RESULTSTotally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-Ia was found in 23 strains, and the aac-6'-Ib gene in 19 strains. aac-3-Ia and aac-6'-Ib genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype.

CONCLUSIONSA. baumanii can carry multiple drug-resistant genes at the same time and result in multi-drug resistance. Aminoglycoside-modifying enzyme genes could be hibernating in aminoglycoside sensitive strains without expressing their phenotype.

Acinetobacter ; genetics ; metabolism ; pathogenicity ; Acinetobacter Infections ; microbiology ; Bacterial Proteins ; genetics ; Bronchoalveolar Lavage Fluid ; microbiology ; Drug Resistance, Multiple, Bacterial ; genetics ; Humans ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Respiratory Tract Infections ; microbiology ; Sputum ; microbiology