[Association, differences, and applications of three commonly used statistical indicators: risk ratio, hazard ratio, and odds ratio].

Relative Risk (RR), Hazard Ratio (HR), and Odds Ratio (OR) are commonly used statistical measures in the field of public health to assess the magnitude of the effect of exposure factors on outcomes. These indicators have different calculation principles and implications in public health. However, a few researchers misused or misinterpreted RR, HR, and OR values when interpreting study results. Therefore, this article explores the relationships and differences among these measures, as well as the correct selection and application of RR, HR, and OR in both cohort study and case-control study.

[Community-acquired infection of external nose caused by enterobacter cloacae: a case report].

Summary A 29-year-old negro woman was admitted with external nasal pain and swelling for 5 weeks. The incision and drainage was done and a few of pus were drained out. CT scan showed the possibility of infectious lesions with nasal soft tissue swelling and increased density. The diagnosis was external nasal cellulitis, and the causative bacteria were enterobacter cloacae.

An efficient algorithm for computing fixed length attractors based on bounded model checking in synchronous Boolean networks with biochemical applications.

Genetic regulatory networks are the key to understanding biochemical systems. One condition of the genetic regulatory network under different living environments can be modeled as a synchronous Boolean network. The attractors of these Boolean networks will help biologists to identify determinant and stable factors. Existing methods identify attractors based on a random initial state or the entire state simultaneously. They cannot identify the fixed length attractors directly. The complexity of including time increases exponentially with respect to the attractor number and length of attractors. This study used the bounded model checking to quickly locate fixed length attractors. Based on the SAT solver, we propose a new algorithm for efficiently computing the fixed length attractors, which is more suitable for large Boolean networks and numerous attractors' networks. After comparison using the tool BooleNet, empirical experiments involving biochemical systems demonstrated the feasibility and efficiency of our approach.

Expression of mel gene improves the UV resistance of Bacillus thuringiensis.

AIMS: To improve ultraviolet (UV) resistance of Bacillus thuringiensis for increasing the duration of the Bt product applied in the field, a genetically engineered strain Bt TD841 that produced both melanin and Cry1A protein was constructed, and its UV resistance was evaluated in the laboratory. METHODS AND RESULTS: Melanin quantitative analysis revealed that the recombinant strain Bt TD841 could synthesize 0.15 mg melanin ml(-1) sporulated culture. Atomic force microscopy confirmed the production of diamond crystal and SDS-PAGE results showed the expression of the 130 kDa Cry1A protein. Bioassay results demonstrated that the LC(50) value of Bt TD841 was 3.69 microl ml(-1) against Helicoverpa armigera and the UV resistance of this recombinant was enhanced 9.7-fold compared to its parental strain Bt HC42 after 4-h UV irradiation. CONCLUSION: Expression of the mel gene can significantly increase UV resistance of B. thuringiensis. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on genetically engineered Bt strain with co-expression of melanin and the insecticidal crystal proteins gene, and the results may offer a practical solution for improving the photoprotection of Bt products in field application.

The synergistic activity between Cry1Aa and Cry1c from Bacillus thuringiensis against Spodoptera exigua and Helicoverpa armigera.

AIMS: To investigate the interaction between two crystal proteins, Cry1Aa and Cry1C, for future development of biopesticides based on Bacillus thuringiensis, toxicities of the two individual proteins and in combinations have been determined against Spodoptera exigua and Helicoverpa armigera larvae, and synergism between the proteins has been evaluated using synergistic factor. METHODS AND RESULTS: SDS-PAGE showed that Cry1Aa and Cry1C proteins could be expressed in acrystalliferous B. thuringiensis 4Q7 strain, with molecular weights of 135 and 130 kDa respectively. The bioassay results indicated a synergistic activity between Cry1Aa and Cry1C against S. exigua and H. armigera, and the highest toxicities could be observed in the combination of Cry1Aa and Cry1C at a ratio of 1 : 1. CONCLUSION: The two toxins, Cry1Aa and Cry1C, interact synergistically to exhibit higher toxicity against S. exigua and H. armigera. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the investigation on the synergistic activity between two B. thuringiensis Cry1 toxins. It can be applied to the rational design of new generations of B. thuringiensis biopesticides and to strategies for management of resistant insects.

Construction of acetate auxotrophs of Neisseria meningitidis to study host-meningococcal endotoxin interactions.

To facilitate studies of the molecular determinants of host-meningococcal lipooligosaccharide (endotoxin) interactions at patho-physiologically relevant endotoxin concentrations (i.e. < or =10 ng/ml), we have generated acetate auxotrophs NMBACE1 from encapsulated Neisseria meningitidis (serogroup B, strain NMB) and NMBACE2 from an isogenic bacterial mutant lacking the polysialic acid capsule. Growth of the auxotrophs in medium containing [(14)C]acetate yielded (14)C-lipooligosaccharides containing approximately 600 cpm/ng. Gel sieving resolved 14C-lipooligosaccharide-containing aggregates with an estimated molecular mass of > or =20 x 10(6) Da (peak A) and approximately 1 x 10(6) Da (peak B) from both strains. Lipooligosaccharides in peaks A and B had the same fatty acid composition and SDS-polyacrylamide gel electrophoresis profile. 14C-Labeled capsule copurified with (14)C-lipooligosaccharides in peak B from NMBACE1, whereas the other aggregates contained only 14C-lipooligosaccharide. For all aggregates, lipopolysaccharide-binding protein and soluble CD14-induced delivery of lipooligosaccharides to endothelial cells and cell activation correlated with disaggregation of lipooligosaccharides. These processes were inhibited by the presence of capsule but unaffected by the size of the aggregates. In contrast, endotoxin activation of cells containing membrane CD14 was unaffected by capsule but diminished when endotoxin was presented in larger aggregates. These findings demonstrate that the physical presentation of lipooligosaccharide, including possible interactions with capsule, affect the ability of meningococcal endotoxin to interact with and activate specific host targets.

Parvalbumin immunoreactive Cajal-Retzius and non-Cajal-Retzius neurons in layer I of different cortical regions of human newborn.

Neurons of layer I play an important role in the development of the basic structural and functional organization of the mammalian cerebral cortex. Basic data, however, concerning the spatial and temporal distribution of the neuron populations in layer I are still limited, especially for human material. The present study investigates the distribution of Cajal-Retzius (CR) and non Cajal-Retzius (NCR) neurons in thirteen cortical areas in the newborn human in terms of their relative density and possible subtypes. Neuronal populations were identified by immunohistochemistry for parvalbumin. Three main results are reported. First, parvalbumin-immunoreactive (Parv-ir) CR cells were observed in all of the neocortical areas examined. These areas also had a Parv-ir horizontal fiber plexus in deep layer I, confirming to the horizontal plexus classically associated with CR neurons. Second, many Parv-ir CR cells showed clear signs of degeneration. Third, in addition to the large CR cells, smaller Parv-ir NCR neurons occurred in many of the neocortical areas examined. These were morphologically heterogeneous and may represent several subtypes. By sampling across several areas, we were able to establish that these NCR cells occurred at higher density in primary sensory areas 3, 1, 17, and 41. Because of this variability in density of Parv-ir NCR cells, the ratio of Parv-ir CR to Parv-ir NCR cells is selectively lower in primary sensory areas. Recent investigations in somatosensory cortex of early postnatal rat report complex spatiotemporal patterns of correlated spontaneous activity among neurons in layer I (Schwartz et al. 1998). An interesting possibility is that regional variability in this activity may play a major role in the organization of cortical circuitry in different areas.

[Naloxone suppresses ischemic arrhythmias via potentiating baroreflex].

AIM: To study the relationship between the anti-arrhythmia action of naloxone (Nal) and its effect on baroreflex sensitivity (BRS). METHODS: Acute myocardial infarction was produced by ligating coronary artery in Sprague-Dawley rats. Ventricular extrasystole (VE), tachycardia (VT), and fibrillation (VF) were recorded on ECG. The slopes of linear regression (b) from systolic blood pressure and cardiac cycle after intravenous injection (i.v.) of phenylephrine 2 micrograms was taken as the BRS. The area of infarct was estimated after TTC staining. RESULTS: Nal 0.5 mg i.v., intracisternal injection (i.c.) of Nal 0.1 mg, and i.c. beta-endorphin (beta-End) antiserum 10 microL suppressed the ischemic arrhythmias, arrhythmia score was 1.8 +/- 1.1 (Nal i.v.) vs 3.8 +/- 2.1 (Saline i.v.); 1.7 +/- 1.5 (Nal i.c.) vs 4.0 +/- 2.6 (Artificial CSF i.c.) and 1.7 +/- 1.6 (beta-End antiserum i.c.) vs 4.1 +/- 2.0 (Serum i.c.) (P < 0.05) and potentiated the BRS, BRS was 4.2 +/- 1.8 (Nal i.v.) vs 2.9 +/- 0.8 (saline i.v.); 4.5 +/- 1.7 (Nal i.c.) vs 2.8 +/- 0.7 (Artificial CSF i.c.) and 4.4 +/- 1.1 (beta-End antiserum i.c.) vs 3.0 +/- 0.9 (Serum i.c.) (P < 0.05). BRS showed negative relations to the arrhythmia scores with r of -0.69 for i.v Nal, -0.72 for i.c. Nal, and -0.67 for i.c. beta-End antiserum (P < 0.05). CONCLUSION: Nal suppressed ischemic arrhythmias via antagonization of beta-endorphin and potentiation of BRS.

[Effects of captopril on platelet-derived growth factor ligand and receptor gene expression of vascular wall after balloon angioplasty].

A predominant fibromuscular plaque was produced by balloon catheter denuding angioplasty of both iliac arteries and feeding cholesterol in 16 New Zealand white rabbits. Balloon angioplasty was performed in model animals. Captopril-treated (n = 8, captopril 12.5 mg.kg-1/d) group which received captopril 7 days before to 4 wk after angioplasty were examined by dot blot hybridization. The results showed that captopril can inhibit platelet-derived growth factor ligand and receptor gene expression of vascular wall after balloon angioplasty.

The effect of mangxiao (natrii sulphas) in the relief of stasis and swelling after implantation of cardiac pacer.

Sixteen patients with local stasis and swelling after implanting cardiac pacemaker were treated with Mangxiao (Natrii Sulphas) on the implanted local surface for 4-14 days. The effect was satisfactory. Reopening of the skin for the cleaning of the stasis and swelling and removal of the pacemakers could thus be avoided in these patients. The mechanism of action of Mangxiao in relieving stasis and swelling was studied preliminarily.

Assessment of Nd:YAG laser via metal cap and sapphire tip delivery system. An experimental and clinical investigation.

Sixteen segments of normal human aorta were irradiated by Nd:YAG laser beam delivered via domestically made metal cap and sapphire tip fibre systems. It was found that the metal tip fibre caused more target tissue damage and adhesion than the sapphire tip fibre. The sapphire tip fibre caused an ablation crater with a smoother edge, less carbonization layer and smaller thermal necrotic zone than the metal tip did. The metal cap and sapphire tip fibre were applied to 2 cases of iliac artery stenosis and 5 cases of coronary stenosis, all showing an immediate ablation.

Prenatal development of GABA-immunoreactive neurons in the human striate cortex.

The prenatal development of neurons immunoreactive to gamma-aminobutyric acid (GABA) in the striate cortex (area 17) of human foetuses aged from 14 weeks to term was studied immunocytochemically. In the 14 week foetus GABA-immunoreactive cells occurred in all layers of area 17 with the highest density in the marginal zone (MZ), subplate (SP), deep intermediate zone (IZ) and ventricular zone (VZ). The cortical plate (CP), which gives rise to most of the definitive adult cortical layers, had relatively low concentrations of GABAergic cells. By 17 weeks the density in the proliferative VZ had declined. At 20 weeks some of the adult layers were recognisable; the density of GABA-positive neurons was now highest in the definitive cortex, especially the deep layers (layers VI and V), was lower in the superficial cortical plate, and was lowest in IZ, where the white matter would form. The peak of GABA-immunoreactive neuronal density continued to move superficially during development, and was in layer IVc by 30 weeks. The laminar distribution stabilised from 30 weeks with three dense bands: in layer IVc and superficial V, layer IVa, and layers II and superficial III. The tangential distribution of GABAergic neurons was determined in two older brains (32 and 39 weeks) and no unequivocal spatial periodicity was observed in this plane. The mean cross-sectional area of GABAergic neurons in area 17 increased with foetal age, and also increased from superficial to deep layers at each age. Most GABA-immunoreactive neurons in younger brains contained immunonegative or weakly positive nuclei and had few visible processes, while in the older brains most neurons contained positive nuclei and had more visible processes. The proportion of GABA-immunoreactive bipolar cells declined during development while that of multipolar cells increased. GABAergic neurons thus differentiate early in human foetal striate cortex. They are initially most numerous in the proliferative layers deep to the developing definitive cortex; from 20 weeks of gestation, their peak moves superficially into the maturing deep layers (VI and V) and a stable laminar distribution is attained by 30 weeks, with peaks in layers II/IIIm, IVa and IVc/V. There is no obvious horizontal periodic distribution before term.

Factors influencing ablation of atherosclerotic plaque with argon laser.

The ablative effect of argon laser delivered fibreoptically in vitro on 234 segments of atherosclerotic human aorta was studied. The variables such as energy density, type of atheroma and immersion media were included, and all irradiated specimens were subsequently submitted to histological examination and crater volumes in mm3 to micrometer measurements under light microscope. The results showed 1) a linear relationship between energy dose and crater volume in fibrous atheroma, 2) significantly greater damage or surrounding in the higher energy dose groups, 3) a lower dose response in calcified tissue than in fatty streaks or fibrous atheroma, and 4) immersion of tissue in blood during ablation resulted in a significantly greater dose response than immersion in plasma or saline, and the corresponding surrounding tissue damage was greatest when immersed in blood. Thus, argon laser is both effective and predictable in response during ablating of atheromatous tissue. The efficacy of the process is dependent on immersion medium, while the degree of surrounding tissue damage is dependent on energy dose.

Adenosine triphosphate liposomes: encapsulation and distribution studies.

Four methods for encapsulating adenosine triphosphate (ATP) in liposomes were evaluated. Optimum entrapment required emulsifying ATP with the lipids used to form the liposome membrane in a high-speed homogenizer followed by evaporating the organic solvent with vigorous stirring. Under these optimum conditions ATP entrapment was 38.9%; i.e., the dosage form contained 38.9 g of ATP per 100 g of lipid. The distribution of positively charged liposomes loaded with ATP was studied in dogs with experimentally induced myocardial infarction. Intravenous injection of positively charged ATP liposomes caused accumulation of ATP in myocardial infarct tissue. Myocardial infarct tissue has reduced blood flow; since positively charged liposomes accumulated in infarct tissue, liposomes may be a drug delivery system for this disease state.

A clinical investigation with Holter's monitoring of the antiarrhythmic effect of adonisidum.

The authors studied 24 cases of refractory premature beats by giving 0.1 adonisidum twice daily with Holter's monitoring. It was found that adonisidum was effective in 12 cases (P less than 0.001), or 50%. In another 8 patients adonisidum or mexiletine alone were ineffective for premature beats. However, when these patients were treated with both mexiletine and adonisidum, they responded with no exception (P less than 0.001). All 7 cases monitored with one hour Holter recording responded to adonisidum (P less than 0.001). As adonisidum tends to slow the heart rate, it is especially indicated for patients suffering from premature beats with increased heart rate, and should be used with caution in cases with slow heart rate or A-V block.

Periodicity of GABA-containing cells in primate prefrontal cortex.

The tangential distribution of GABA-containing cells was examined in the principal sulcus of the frontal lobe in 12 macaque monkeys. Following immunostaining with GABA antisera all immunoreactive cells were charted and their distribution analyzed with both statistical and spectral density methods. In addition, a gapless series of sections was used to generate a 2-dimensional reconstruction of cell disposition in the tangential plane parallel to the pia. Our findings indicate that the GABA cells are not distributed uniformly across the cortex, as is commonly believed, but that their density is characterized by 2 independent sinusoidal fluctuations: a high-frequency component with a period ranging from 150 to 250 micron superimposed upon a lower-frequency component with a period of 1000-1275 micron. The half-cycle of the low-frequency component (roughly 625 micron) is very similar to the dimensions of afferent and efferent columns in the principal sulcus, while the half-cycle of the higher-frequency component (approximately 125 micron) is closer in size to that of the functionally defined columns of neurons found in regions of sensory cortex that share common physiological properties. To our knowledge, these findings are the first indication that inhibitory local circuit neurons are not uniformly or randomly distributed, but exhibit periodicities that may be related to the columnar, functional and architectural organization of the cortex.