Safety of the application of Rigidfix cross-pin system via different tibial tunnels for tibial fixation during anterior cruciate ligament reconstruction

BACKGROUND

We investigate the safety of the application of the Rigidfix cross-pin system via different tibial tunnels in the tibial fixation during anterior cruciate ligament (ACL) reconstruction.

METHODS

Five adult fresh cadaver knees were fixed with the Rigidfix cross-pins in the tibial fixation site during ACL reconstruction. Two different tibial tunnel groups were established: in group A, the tunnel external aperture was placed at the 25° angle of coronal section; in group B, the tunnel external aperture was placed at the 45° angle of coronal section. The guide was placed at the plane 0.5 mm below articular facet through the tibial tunnel, with three rotation positions set at 0°, 30°, and 60° slopes. The incidences of iatrogenic injuries at tibial plateau cartilage (TPC), medial collateral ligament (MCL), and patellar tendon in three different slope angles were calculated in groups A and B and the results were analyzed by using chi square test.

RESULTS

The iatrogenic injuries at MCL, TPC, and patellar tendon could occur after the Rigidfix cross-pin system was placed 5 mm below tibial plateau cartilage for ACL reconstruction. The incidences of TPC injury (χ² = 5.662, P = 0.017) and MCL injury (P = 0.048, Fisher exact probability method) were significantly lower in group A than in group B. However, the incidence of patellar tendon injury showed no significant difference between these two groups (χ² = 0.120, P = 0.729).

CONCLUSIONS

When the Rigidfix cross-pin system is used for ACL reconstruction at the tibial fixation site, the external aperture of tibial tunnel should not be placed at the excessively posterosuperior site, to avoid MCL and TPC injuries.

Evaluating the efficacy of recombinant human bone morphogenic protein-2 in the treatment of alveolar clefts with autologous bone grafting using computer-aided engineering techniques

Recent studies have indicated the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) to be a viable adjunctive to alveolar cleft reconstruction owing to its osteoinductive capacity. This study aimed to evaluate the efficacy of rhBMP-2 in the treatment of alveolar cleft with autologous bone grafts by precise volumetric analysis. Twenty-six patients (aged 8-14) with unilateral alveolar clefts were enrolled in this comparative study. Patients were divided into two groups: the iliac crest bone graft (ICBG) was placed at the side of the cleft in the control group (ICBG group), and rhBMP-2 was mixed with the ICBG in the rhBMP-2 group (BMP group). Helical computed tomographic images were obtained preoperatively and 12 months postoperatively. The datasets were reconstructed as three-dimensional (3D) images using Mimics software and processed using Geomagic Wrap. The newly formed bone of the alveolar cleft was segmented by identifying the differences between preoperative and postoperative 3D images. In the ICBG group, the volume of newly formed bone ranged from 0.25 to 0.88 cm³, and the mean (SD) bone formation percentage was 42.01% (15.57%). In the BMP group, the volume of newly formed bone ranged from 0.34 to 1.09 cm³, and the bone formation mean (SD) percentage was 55.79% (11.84%). There was a statistically significant difference between the two groups in terms of the postoperative percentage of bone formation (p = 0.022). Thus, rhBMP-2 combined with an autologous bone graft is a promising technique to improve the results of secondary alveolar bone grafting.

[Value of European Organisation for Research and Treatment of Cancer score system for predication of immediate postoperative intravesical instillation of pirarubicin after transurethral resection of non-muscle invasive bladder cancer]

Objective: To assess value of immediate postoperative intravesical instillation of pirarubicin after transurethral resection (TURBT)of non-muscle invasive bladder cancer. Methods: 484 patients diagnosed with non-muscle-invasive bladder cancer admitted to the Second Affiliated Hospital of Kunming Medical University were divided into two groups after transurethral resection of bladder tumor. 285 patients received postoperative intravesical instillation of pirarubicin within 6 hours after the surgery, 199 patients received first instillation of pirarubicin at 10 days after the surgery, after that, all the patients received routine bladder perfusion chemotherapy. Patients who received intravesical instillation of pirarubicin within 6 hours were defined as immediate intravesical instillation group and the other patients as the control group. Based on the European Organisation for Research and Treatment of Cancer risk tables, scores of recurrence and progression of patients were calculated and then stratified into risk groups accordingly. Recurrence and progression rates of the immediate intravesical instillation group were analyzed and then compared with the corresponding reference of the risk tables. Results: The 1-year and 5-year recurrence rate of patients with EORTC table scoring 0 in the immediate intravesical instillation group were significantly lower than that of the EORTC reference group (5.3% and 14.0% vs 15.0% and 31.0%, P<0.05). 1-year recurrence free rate between the immediate intravesical instillation group and the control group in patients scoring 1-4 was significantly different (81.3% vs 76.7%, P=0.014). However, 1-year recurrence free rate of the immediate intravesical instillation group was comparable with that of the control group in patients scoring 5-9, 10-17(P>0.05), which is quite close to the EORTC reference. The probability rates of 1-year and 5-year progression of the 285 patients who received immediate intravesical instillation group did not show significant difference with the EORTC reference. On multivariate analysis, previous recurrence, tumor grade G2-3, tumor multiplicity, delay of immediate intravesical instillation were independent risk factors of recurrence(P<0.05). Conclusions: With the help of EORTC recurrence risk table stratifying the patients into different risk groups, our study showed that delay of immediate postoperative intravesical instillation of chemotherapy after TURBT was an independent risk factor of post-surgery recurrence of tumor. Moreover, patients with EORTC scoring 1-4 might obtain greatest benefits.

[Determination of relative elements of hard metal in workplace air and urine by inductive coupled plama]

Objective: To establish a rapid detection method regarding the air conditions of workplace and the workers' urine included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds based on inductively coupled plasma mass spectrometry (ICP-MS) . Methods: The experiment adopts ICP-MS to deter-mine those metals in workshop air and workers urine, evaluate the detection's limitation, the precision and accuracy of the method. Using the membrane filter and urine freeze - dried metal standard material to verify this method. Results: Each element of correlation coefficient was greater than 0.999. The recovery rate of air samples was 91.6%~104.6%, within-batch RSD precision was 1.41%~3.50%, between-run precision was 1.28%~4.31%, urine samples recovery rate was 93.0%~102.6%, within - batch RSD precision was 1.25%~3.56%, between - run precision was 1.58%~4.67%, According to the method every element was within the scope of the standard reference, it was also showed that the established method is accurate and reliable. Conclusion: ICP-MS is an effective and feasible method to detect the workshop air and the workers' urine which included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds.

Unconventional interplay between heterovalent dopant elements: Switch-and-modulator band-gap engineering in (Y, Co)-Codoped CeO2 nanocrystals

We report the experimental observation and theoretical explanation of an unconventional interplay between divalent Co and trivalent Y dopants, both of which incur oxygen vacancies in the CeO₂ host that has predominantly tetravalent Ce cations. The Co dopant atoms were experimentally found to act as a switch that turns on the dormant effect of Y-modulated band-gap reduction. As revealed by density functional theory (DFT) calculations with structures verified by synchrotron-radiation x-ray measurements, a Co 3d band that hybridizes with Ce 4f band was lowered due to reduced O 2p repulsion arising from oxygen vacancies incurred by Y doping and therefore gave rise to the observed band-gap narrowing effect. Such switch-and-modulator scheme for band-gap engineering in nanocrystal materials can lead to important applications in environmental protection and solar energy harvesting technologies.

Phase transformation and enhanced photocatalytic activity of S-doped Ag2O/TiO2 heterostructured nanobelts

Ag2O/TiO2 nanobelt heterostructures have been found to possess high ultraviolet photocatalytic activity, but a poor cycling performance. After a S-doping treatment, the obtained Ag2O/Ag2S2O7/TiO2 heterostructured nanobelts exhibited an enhanced and stable photocatalytic activity under both ultraviolet and visible light irradiation, which was exemplified by photo-degradation of organic pollutants and photocurrent response measurements. Meanwhile, the crystal structure and phase transformation of Ag2O, Ag2S2O7 and Ag2S were studied by XRD and XPS measurements.

2,2,2-Trifluoro-N-(4-methyl-2-oxo-2H-chromen-7-yl)acetamide

In the title molecule, C12H8F3NO3, the trifluoromethyl group is rotationally disordered over three orientations in a 0.5:0.3:0.2 ratio. In the crystal, N—H...O hydrogen bonds link the molecules related by translation into chains along thecaxis. The crystal packing exhibits π–π interactions between the pyran rings of neighboring molecules [centroid–centroid distance = 3.462 (4) Å] and short C...O contacts of 3.149 (4) Å.

7-Diethyl-amino-2-oxo-2H-chromene-3-carbaldehyde

In the title compound, C(14)H(15)NO(3), all non-H atoms except for those of the methyl and the disordered ethyl groupare approximately co-planar, the largest deviation from the mean plane being 0.0223 (13) Å at the N atom. In the crystal, the packing of mol-ecules through weak inter-molecular C-H⋯O hydrogen-bonding inter-actions leads to the formation of layers parallel to bc plane. Within these layers, there exist slipped π-π stacking inter-actions between symmetry-related fused rings [centroid-centroid distances = 3.527 (3) and 3.554 (3), slippage = 0.988 and 1.011 Å, respectively]. One ethyl group is disordered over two sets of sites with site-occupation factors of 0.54 and 0.46.

Quantitative trait loci analysis of swine meat quality traits

A QTL study was performed in large half-sib families to characterize the genetic background of variation in pork quality traits as well as to examine the possibilities of including QTL in a marker-assisted selection scheme. The quality traits included ultimate pH in LM and the semimembranosus, drip loss, and the Minolta color measurements L*, a*, and b* representing meat lightness, redness, and yellowness, respectively. The families consist of 3,883 progenies of 12 Duroc boars that were evaluated to identify the QTL. The linkage map consists of 462 SNP markers on 18 porcine autosomes. Quantitative trait loci were mapped using a linear mixed model with fixed factors (sire, sex, herd, month, sow age) and random factors (polygenic effect, QTL effects, and litter). Chromosome-wide and genome-wide significance thresholds were determined by Peipho's approach, and 95% Bayes credibility intervals were estimated from a posterior distribution of the QTL position. In total, 31 QTL for the 6 meat quality traits were found to be significant at the 5% chromosome-wide level, among which 11 QTL were significant at the 5% genome-wide level and 5 of these were significant at the 0.1% genome-wide level. Segregation of the identified QTL in different families was also investigated. Most of the identified QTL segregated in 1 or 2 families. For the QTL affecting ultimate pH in LM and semimembranosus and L* and b* value on SSC6, the positions of the QTL and the shapes of the likelihood curves were almost the same. In addition, a strong correlation of the estimated effects of these QTL was found between the 4 traits, indicating that the same genes control these traits. A similar pattern was seen on SSC15 for the QTL affecting ultimate pH in the 2 muscles and drip loss. The results from this study will be helpful for fine mapping and identifying genes affecting meat quality traits, and tightly linked markers may be incorporated into marker-assisted selection programs.

Toll-like receptor 2 gene polymorphism and its relationship with SCS in dairy cattle

Toll-like receptor 2 (TLR2) plays an important role in the innate immune response to a variety of pathogens. In this study, bovine TLR2 gene was taken as a candidate gene for mastitis resistance. Through PCR-SSCP analysis and sequencing, three missense mutations at T385 G, G398A, and G1884A were detected in the coding region that encoded extracellular domain. Altogether 240 dairy cattle of three breeds (Holstein, Simmental, and Sanhe cattle) were genotyped and allele frequencies were determined. The effects of TLR2 polymorphisms on somatic cell score (SCS) were analyzed and significant association was found between T385 G and SCS. The mean of genotype GG was significantly lower than those of genotype TT and TG. No significant associations were found with SCS for G398A and G1884A. Information provided in this research will be useful in further studies to determine the role of TLR2 gene in the mastitis resistance.

Hyaluronic acid-poly-D-lysine-based three-dimensional hydrogel for traumatic brain injury

Brain tissue engineering in the postinjury brain represents a promising option for cellular replacement and rescue, providing a cell scaffold for either transplanted or resident cells. In this article, a hyaluronic acid (HA)-poly-D-lysine (PDL) copolymer hydrogel with an open porous structure and viscoelastic properties similar to neural tissue has been developed for brain tissue engineering. The chemicophysical properties of the hydrogel with HA:PDL ratios of 10:1, 5:1, and 4:1 were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectrometry. Neural cells cultured in the hydrogel were studied by phase-contrast microscope and SEM. The incorporation of PDL peptides into the HA-PDL hydrogel allowed for the modulation of neuronal cell adhesion and neural network formation. Macrophages and multinucleated foreign body giant cells found at the site of implantation of the hydrogel in the rat brain within the first weeks postimplantation decreased in numbers after 6 weeks, consistent with the host response to inert implants in numerous tissues. Of importance was the infiltration of the hydrogel by glial fibrillary acidic protein-positive cells-reactive astrocytes-by immunohistochemistry and the contiguity between the hydrogel and the surrounding tissue demonstrated by SEM. These findings indicated the compatibility of this hydrogel with brain tissue. Collectively, the results demonstrate the promise of an HA-PDL hydrogel as a scaffold material for the repair of defects in the brain.

Hyaluronic acid hydrogel as Nogo-66 receptor antibody delivery system for the repairing of injured rat brain: in vitro

Nogo-66 and NgR are important receptors inhibiting neuronal regeneration and therefore are targets for treating CNS injury. Antagonists of this receptor including blocking antibodies are potential therapeutic agents for CNS axonal injuries such as spinal cord and brain trauma. A new antibody (IgG) releasing system has been developed by covalently attaching IgG to the biodegradable hyaluronic acid (HA) hydrogel via the hydrolytically unstable hydrazone linkage, aiming to deliver the antibody of CNS regeneration inhibitors to the injured brain. In this paper we describe the synthesis, physico-chemical characteristics and test results of biological activity of antibody released from hyluronic acid hydrogel. To form the conjugates the antibody is attached to the polymer backbone using a condensation reaction between aldehyde group of the antibody and hydrazide group of the HA hydrogel. Furthermore, pH sensitive linkage-hydrozone has been formed between hydrogel and antibody. The amount of conjugated antibodies can reach 135 microg antibody/mg hydrogel in the dry state. At low pH, the antibodies released quite fast. However, the antibodies released much slower in neutral and alkaline environment. The bioactivity of antibody released from hydrogel was retained as demonstrated by indirect immunofluorescence technique.

A comparison of fructosamine and HbA1c for home self-monitoring blood glucose levels in type 2 diabetes

BACKGROUND

Optimal glycemic control is believed to be essential in patients with diabetes to minimize any long-term complications. Measurement of the levels of glycated protein, such as fructosamine and glycated hemoglobin (HbA1c), is the most reliable method for assessing a period of glycemic control. This prospective study was performed to investigate whether fructosamine or HbA1c could provide a reliable index of glycemic control in type 2 diabetes.

METHODS

Twenty-five patients with type 2 diabetes were studied at four-week intervals. Their fasting, preprandial and postprandial blood glucose levels were checked by glucometer twice a week for 16 weeks. Serum fructosamine and HbA1c were measured on every visit. The correlation of fructosamine and HbA1c with self-monitoring of blood glucose (SMBG) values in the previous 1 to 16 weeks prior to their measurements were calculated.

RESULTS

Both fructosamine and HbA1c were significantly correlated with SMBG values from one week to 16 weeks prior to measurements. The correlation between fructosamine and SMBG was stronger in the prior 3 to 6 weeks. The correlation between HbA1c and SMBG was higher in the previous 4 to 12 weeks with the peak falling in the previous 8-10 weeks. Except for the previous one week, all the correlations were significantly stronger between HbA1c and SMBG than between fructosamine and SMBG.

CONCLUSIONS

In type 2 diabetes, serum fructosamine assay can better reflect average blood glucose concentration over the previous 3 to 6 weeks and HbA1c is better reflective over the previous 8 to 10 weeks. HbA1c measurement correlates more significantly with home capillary blood glucose levels than the fructosamine assay, even over the previous 2 to 3 weeks.

Experimental and computational studies of the relative flow field in a centrifugal blood pump

The relative flow field within the impeller passage of a centrifugal blood pump had been examined using flow visualization technique and computational fluid dynamics. It was found that for a seven-blade radial impeller design, the required flow rate and static pressure rise across the pump could be achieved but the flow field within the blades was highly undesirable. Two vortices were observed near the suction side and these could lead to thrombus formation. Preliminary results presented in this article are part of our overall effort to minimize undesirable flow patterns such flow separation and high shear stress regions within the centrifugal blood pump. This will facilitate the future progress in developing a long-term clinically effective blood pump.

[HPLC determination of PAHs from electric power plant by UVD-FLD connected in series]

An HPLC method of UVD-FLD connected in series was used to detect naphthalene, biphenyl, fluorene, phenanthrene, anthracene, fluoranthene, 2-methyl-anthracene, chrysene, benzanthracene, benzfluoranthene [b], benzfluoranthene[k], benzopyrene PAH compounds in electricity plant environment. A CLC-ODS column (150 mm x 6.0 mm i.d.) with acetonitrile-water(85:15, V/V) as mobile phase and UV detector set at 250 nm and fluorescent detector set at lambda ex295 nm and lambda em427 nm were used. These 12 PAHs can be separated completely by this method. The earlier eluted eight PAHs were detected by UVD and the rest were detected by FLD. The minimum detectable concentrations of the 12 PAHs were 0.002 mg/L-0.1 mg/L. Satisfactory results were obtained in the analysis of PAH compounds in waste water, flue gas and flyash from several electric power plant in Hunan Province.

Effects of rhM-CSF expressed in silkworm on cytokine productions and membrane molecule expressions of human monocytes

AIM

To study the effects of recombinant human macrophage colony-stimulating factor (rhM-CSF) expressed in silkworm on cytokine productions and membrane molecule expressions of monocytes.

METHODS

The rhM-CSF was added to the human peripheral blood monocyte cultures and 3 d later, the culture supernatants and cells were collected, respectively. TNF-alpha, IL-6, IL-8, and IFN-alpha levels in the supernatants were detected by biological activity test or ELISA and expressions of CD11b, CD16, HLA I, and HLA II on the cellular surface were examined by the method of alkaline phosphatase anti-alkaline phosphatase complex (APAAP).

RESULTS

The rhM-CSF promoted TNF-alpha, IL-6, and IL-8 inductions of monocytes and increased the percentages of CD11b, CD16, HLA I, and HLA II molecule expression on monocytes.

CONCLUSION

The rhM-CSF plays a role in monocyte function up-regulation and has a certain practical value in immunological therapy.

Analytical investigation of leakage flow in disk clearance of a magnetically suspended centrifugal impeller

Leakage flow through the disk clearance of a magnetically suspended centrifugal blood pump is essential for a good washout. An analytical approach, based on the theory of lubrication, is used to predict the leakage volume flow rate, nondimensional radial velocity, nondimensional mean pressure distribution, and comparative shear stress distribution for different disk clearance geometry under varying rotational speeds. The results showed that nondimensional mean pressure distribution and nondimensional radial velocity distribution along the clearance are independent of rotational speed. The flow through the gap depends on a nondimensional parameter S that denotes the ratio of centrifugal forces to the head generating capability of the impeller. It was found that an impeller having a lower S has less possibility of flow reversals in the gap, and gap with maximum height at the outside radius also is more susceptible to flow reversals at the impeller surface. The comparative shear stress within the gap reveals that, in general, the scalar stress is below 500 N/m2.

Effects of corticotrophin on pain behavior and BDNF, CRF levels in frontal cortex of rats suffering from chronic pain

AIM

To investigate the effects of corticotrophin (Cor) on corticotropin-releasing factor (CRF), brain-derived neurotrophic factor (BDNF), and its functional receptor trkB in the frontal cortex of complete Freud's adjuvant (CFA)-induced arthritic rats.

METHODS

The chronic pain rat model was modified and pain behaviour scores were assessed. BDNF-immunoreactivity (IR), trkB-IR, and CRF mRNA-positive neurons were measured by immunohistochemistry and in situ hybridization methods.

RESULTS

Compared with control rats, pain behavior scores, BDNF-IR, CRF mRNA-positive, trkB-IR, and BDNF/CRF mRNA double-labeling neurons in the contralateral frontal cortex of the arthritic rats increased significantly at 24 h after injection of CFA (P < 0.05), and these effects were decreased markedly by i.p. injection of Cor (P < 0.05). The decrease in pain behavior and BDNF-IR, CRF mRNA levels in frontal cortex of arthritic rats due to Cor were partly prevented by adrenalectomy (ADX).

CONCLUSION

The increment in BDNF and CRF levels in the contralateral frontal cortex of arthritic rats may be inhibited by corticotrophin.

Effects of intra-hippocampal injection of interleukin-2 on pain threshold and formaldehyde-induced substance P-like immunoreactivity in periaqueductal gray and spinal cord

AIM

To study the effects of intra-hippocampal injection of interleukin-2 (IL-2) on the substance P-like immunoreactivity (SP-LI) in both periaqueductal gray (PAG) and spinal cord, and on pain threshold in rats.

METHODS

Immunohistochemistry technique was used and the paw withdrawal threshold to radiant heat was measured.

RESULTS

Microinjection of hIL-2 480 U in hippocampus (Hip) increased the pain threshold (93% +/- 57%, P < 0.01). Injection of formaldehyde (For) in one hindpaw decreased SP-LI neuron number on both sides of PAG (2.9 +/- 2.8 vs 22.1 +/- 0.7, 12.3 +/- 2.0 vs 22.4 +/- 1.0, P < 0.01) and increased SP-LI in ipsilateral spinal cord (0.836 +/- 0.015 vs 0.59 +/- 0.09, P < 0.01). Microinjection of hIL-2 480 U in Hip inhibited the effects of For on the SP-LI on both sides of the PAG (11.3 +/- 2.3 vs 2.9 +/- 2.8, 16.9 +/- 3.4 vs 12.3 +/- 2.0, P < 0.05) and spinal cord (0.71 +/- 0.03 vs 0.836 +/- 0.015, P < 0.01). The combination of intraperitoneal injection of corticotropin and intra-hippocampal injection of IL-2 increased the number of SP-LI neurons in PAG furtherly as compared with IL-2 240 U alone (13.6 +/- 3.6 vs 7.6 +/- 4.3, P < 0.05).

CONCLUSION

The analgesic effects of intra-hippocampal injection of IL-2 are mediated, possibly, via the increased of SP in PAG and the decrease of SP in the spinal cord. There is a synergetic relation between IL-2 and corticotropin.

Intrathecal injection of corticotropin inhibited nitric-oxide synthase-positive neuron increase in rat spinal cord after formalin-induced hyperalgesia

AIM

To study the effects of corticotropin (Cor) on formalin-induced hyperalgesia and the change of nitric-oxide synthase (NOS)-positive neurons in spinal dorsal horn in rats.

METHODS

Measurement of pain intensity rating (PIR), NADPH-d histochemistry, and Fos immunohistochemistry were adopted.

RESULTS

The increases of NOS-positive neurons, Fos, NOS/Fos double labelling neurons of the spinal dorsal horn and the PIR after formalin injection were markedly inhibited by intrathecal injecting (ith) Cor (0.5-1.5 U), which were obviously attenuated by L-arginine (Arg, 5-15 nmol, ith), the substrate of NOS.

CONCLUSION

Cor inhibits formalin-induced hyperalgesia by the decrease of NOS-positive neurons in the spinal dorsal horn of rats.

[Effect of ACTH on the expression of somatostatin and c-fos in the spinal cord and formalin evoked pain response]

In the present study, the effect of ACTH on the expression of somatostatin and c-fos in the spinal cord and formalin induced pain responses in rats were studied using immunohistochemistry and in situ hybridization. The results showed that subcutaneous injection of formalin in the right hindpaw increased c-fos-like immunoreactivity (FLI), somatostatin-like immunoreactivity (Som-LI), Som-LI/FLI and perprosomatostatin mRNA (PPS-mRNA) in neurones of right spinal dorsal horn and significantly enhanced pain intensity rating. ACTH decreased the FLI,Som-LI, Som-LI/FLI and PPS-mRNA levels of the spinal cord evoked by formalin. The decrease of c-fos or Som level due to intrathecal injection of ACTH in rats with chronic pain was prevented by injection of cyproheptadine, but not by bicuculline and naloxone. The results indicate that the serotonin receptor may be involved in ACTH induced analgesia.

[Effect of corticotrophin on formaldehyde-induced somatostatin of spinal cord in rats]

AIM

To study the effect of corticotrophin (Cor) on somatostatin (Som) and its synthesis in spinal dorsal horn induced by formaldehyde in rats.

METHODS

Using double immunohistochemical stainings, and in situ hybridization.

RESULTS

Two hours after s.c. formaldehyde (5%, 200 microL) in one hindpaw of rats, the neurons of c-fos-like immunoreactivity (FLI), somatostatin-like immunoreactivity (Som-LI), Som-LI/FLI, and perprosomatostatin mRNA (PPS-mRNA) in ipsilateral spinal dorsal horn were increased obviously, as compared with the control group. The FLI and Som-LI of spinal cord were not changed by i.p. Cor. Cor (25 or 12.5 U.kg-1, i.p.) inhibited the formaldehyde-evoked FLI, Som-LI, Som-LI/FLI, and PPS-mRNA of spinal cord in a dose-dependent manner. The decrease of c-fos or Som level due to i.p. Cor in rats of chronic pain was prevented by raphe nuclei injected cyproheptadine, but not by bicuculline, naloxone, or phentolamin injected to raphe nuclei.

CONCLUSION

The formaldehyde-evoked c-fos expression, Som, and Som synthesis of spinal cord were suppressed by Cor through the serotonin receptor of raphe nuclei.

[Effects of morphine on the formalin induced IL-2R beta mRNA expression of rat hippocampus]

Using method of in situ hybridization, the effects of subcutaneous injection (s.c.) of formalin (For) into one hindpaw (hyperalgesia) on IL-2R beta mRNA expression in hippocampus (Hip) were studied. In addition, the effects of coadministration of morphine (i.p.) or ACTH (i.p.) with For (s.c.) were studied also. It was found that IL-2R beta mRNA was present in normal rat's Hip, intensely in granular cells of dentate gyrus and CA1-CA4 neurons. Subcutaneous injection of For increased IL-2R beta mRNA from 6 h to at least 24 h, reaching a peak at 12 h. Coadministration with morphine enhanced the effects of For on IL-2R beta mRNA expression, but no significant change was found with coadministration of ACTH. The above results suggest that IL-2R might be involved in pain modulation.

[Effect of corticotropin on formalin-evoked c-fos expression of spinal cord and receptors analysis in rat]

AIM

To study the effect of corticotropin (Cor) on c-fos expression induced by formalin in spinal cord of rat and the role of receptors.

METHODS

Using immunohistochemistry and adrenalectomy.

RESULTS

Cor inhibited the formalin-evoked c-fos expression in rat spinal cord in a dose-dependent manner. No obvious effect was seen by i.p. Cor 10 U.kg-1, but 25 U.kg-1 reduced the evoked c-fos expression, that was blocked by phentolamine, naloxone, or verapamil, but not much changed by adrenalectomy.

CONCLUSION

The formalin-evoked c-fos expression of rat spinal cord was suppressed by Cor through the alpha-adrenergic receptors, opiate receptors and calcium, but no relation to adrenal glands.

[Somatostatin and electroacupuncture inhibited c-fos expression in spinal cord of arthritic rats]

AIM

To observer the effect of intrathecal injection of somatostatin (Som) associated with electroacupuncture (EA) at "Jiaji" points on c-fos protein expression of spinal cord in pain rats.

METHODS

Rats with adjuvant arthritis were used as pain model and the c-fos-like immunoreactivity (FLI) was detected by immunohistochemistry.

RESULTS

The c-fos protein expression induced by arthritis were found in all of the I-X laminae of ipsilateral spinal cord of rats, and most of the labeled cells were located in the laminae I-II and V-VI. Som and EA suppressed the c-fos expression and the lessening of FLI cells in the spinal cord.

CONCLUSION

Pathological pain following arthritis activated pain sensitive neurons (PSN) and evoked c-fos expression in spinal cord, Som and EA suppressed activities of these PSN, producing the effect of analgesia.

[Determination of sinomenine HCl in serum and urine by HPLC and its pharmacokinetics in normal volunteers]

A RP-HPLC method was developed to determine the concentrations of sinomenine HCl in serum and urine and its pharmacokinetics was studied in healthy volunteers. C18H37 column was eluted with the mobile phase of acetonitrile--0.01 mol.L-1 sodium phosphate monobasic--N, N, N', N'-tetramethylenediamine (46:54:0.22 v/v, pH 6.9) and the ultraviolet absorbance was monitored at 263 nm. Triazolan was used as internal standard. The calibration curves were linear in the range of 6-480 ng.ml-1 in serum and 0.06-3 micrograms.ml-1 in urine, with mean recoveries of 75.46% and 91.38% respectively. The lowest detectable limits were 4 ng.ml-1 in serum and 40 ng.ml-1 in urine and the RSD for the intra-day and inter-day were less than 5%. A single oral dose of 80 mg sinomenine HCl tablet was given to 8 healthy male volunteers. The concentrations of sinomenine HCl in serum and urine were determined. The serum concentration--time curve was found to fit a two-compartment open model with first order elimination. The pharmacokinetic parameters were: T1/2 alpha 0.791 +/- 0.491 h, T1/2 beta 9.397 +/- 2.425 h, Tmax 1.040 +/- 0.274 h, Cmax 246.604 +/- 71.165 ng.ml-1, AUC 2651.158 +/- 1039.050 ng.h.ml-1, CL 0.033 +/- 0.010 ng.ml-1.

Tree structured wavelet transform segmentation of microcalcifications in digital mammography

A novel multistage algorithm is proposed for the automatic segmentation of microcalcification clusters (MCCs) in digital mammography. First, a previously reported tree structured nonlinear filter is proposed for suppressing image noise, while preserving image details, to potentially reduce the false positive (FP) detection rate for MCCs. Second, a tree structured wavelet transform (TSWT) is applied to the images for microcalcification segmentation. The TSWT employs quadrature mirror filters as basic subunits for both multiresolution decomposition and reconstruction processes, where selective reconstruction of subimages is used to segment MCCs. Third, automatic linear scaling is then used to display the image of the segmented MCCs on a computer monitor for interpretation. The proposed algorithms were applied to an image database of 100 single view mammograms at a resolution of 105 microns and 12 bits deep (4096 gray levels). The database contained 50 cases of biopsy proven malignant MCCs, 8 benign cases, and 42 normal cases. The measured sensitivity (true positive detection rate) was 94% with a low FP detection rate of 1.6 MCCs/image. The image details of the segmented MCCs were reasonably well preserved, for microcalcification of less than 500 microns, with good delineation of the extent of the microcalcification clusters for each case based on visual criteria.

Microstructural investigation of the early external callus after diaphyseal fractures of human long bone

Microstructures of the early external callus after diaphyseal fractures of human long bone were investigated by using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. It was found that the main structural framework of the human early callus consists of disordered, mineralized collagen fibrils with a small fraction of regions of ordered collagen fibrils. X-ray diffraction analyses show that hydroxyapatite containing some carbonate impurity has been the dominant crystalline phase in the human early callus. In addition, a small amount of brushite phase was detected. Selected area diffraction analyses indicated that hydroxyapatite microcrystals were embedded in microfibrils with a diameter of 4.5 nm and well-banded fibrils, whereas brushite particles of 15-20 nm in an irregular shape were located in the noncollagenous organic matter around the nonmineralized, ordered collagen fibrils. The spatial distribution of the brushite particles in the human early callus was for the first time determined. The brushite particles probably serve as the reservoir of calcium and phosphate ions for subsequent mineralized periods rather than the precursor of hydroxyapatite.

Markov random field for tumor detection in digital mammography

A technique is proposed for the detection of tumors in digital mammography. Detection is performed in two steps: segmentation and classification. In segmentation, regions of interest are first extracted from the images by adaptive thresholding. A further reliable segmentation is achieved by a modified Markov random field (MRF) model-based method. In classification, the MRF segmented regions are classified into suspicious and normal by a fuzzy binary decision tree based on a series of radiographic, density-related features. A set of normal (50) and abnormal (45) screen/film mammograms were tested. The latter contained 48 biopsy proven, malignant masses of various types and subtlety. The detection accuracy of the algorithm was evaluated by means of a free response receiver operating characteristic curve which shows the relationship between the detection of true positive masses and the number of false positive alarms per image. The results indicated that a 90% sensitivity can be achieved in the detection of different types of masses at the expense of two falsely detected signals per image. The algorithm was notably successful in the detection of minimal cancers manifested by masses </=10 mm in size. For the 16 such cases in the authors' dataset, a 94% sensitivity was observed with 1.5 false alarms per image. An extensive study of the effects of the algorithm's parameters on its sensitivity and specificity was also performed in order to optimize the method for a clinical, observer performance study.

Structure of artificial enamel lesions after topical applications of high-concentration sodium fluoride solution in vitro

A three-layer structure, including a columnar layer (CL), a buffer layer, and unaffected intact enamel, was successively formed from the outer to the inner part of artificial enamel lesions (AEL) by topical applications of a high-concentration acidic sodium fluoride solution (10,000 ppm, pH 5.6) in vitro. The AEL was produced in bovine enamel that was decalcified for 5 days in a lactic acid gel system. The morphological observations by using scanning electron microscopy showed that the CL was made of columnar deposits of small globules about 0.5 microns in diameter. It was observed for the first time that small globules filled the demineralized interprismatic regions in the buffer layer. The unaffected intact enamel was protected from further demineralization under the acidic condition. Structure and composition of the CL were investigated by using X-ray diffraction and X-ray photoelectron spectroscopy. In the CL the atomic ratio was Ca:P = 12.6 and Ca:F = 0.75, and the small globules were mainly a mixture of polycrystalline calcium fluoride and hydroxyapatite. For comparison, the sound enamel and the AEL attained by applications of 0 and 100 ppm acidic sodium fluoride solutions (pH 5.6) were also investigated. The formation mechanism of the three-layer structure and the related cariostatic effects are discussed.

Digital mammography: M-channel quadrature mirror filters (QMFs) for microcalcification extraction

Multiresolution methods are reported for feature extraction in breast cancer screening using digital mammography. The initial application is directed at the detection of microcalcification clusters (MCCs). Quadrature mirror filter (QMF) banks, using both two and three channel are proposed for the first time for both multiresolution decomposition and reconstruction. These filters are specifically tailored for automatic extraction of MCCs. The QMF multiresolution methods are compared to two channel tree structured wavelet transforms (TSWTs) methods previously reported. The QMF filters are preceded by an advanced tree structured nonlinear filter for noise suppression, prior to feature extraction, in order to minimize the false positive (FP) detection rate in digital mammography. The relative performance of these methods were evaluated using both simulated images and fifteen representative digitized mammograms containing biopsy proven microcalcification clusters. Similar high sensitivity (true positive (TP) detection rate (100%) and high specificity (0.6 average false positive (FP) MCC's/image) were observed, substantially better than more traditional approaches using single scale filters. The three channel QMF method, however, demonstrated better detail preservation of MCC's extracted compared to the two channel method. Detail preservation is important for the characterization of MCC's or individual microcalcifications in cancer screening.

Tree-structured non-linear filter and wavelet transform for microcalcification segmentation in digital mammography

A novel algorithm was developed for computer aided diagnosis of microcalcification clusters in digital mammography. The method includes: (a) tree-structured central weighted median filters with variable shape windowing to suppress image noise but preserve image details; (b) a quasi range dispersion edge detector to increase edge contrast and definition; and (c) tree-structured wavelets for calcification segmentation. The preliminary evaluation of the method on nine mammograms showed that 100% sensitivity can be achieved at the expense of four false positive clusters per image. Research is ongoing for further optimization of the algorithm to reduce the number of false alarms and establish its clinical value.

[Changes of the 5-HT content in hippocampus, midbrain-pons, spinal cord and concentration of blood glucose after intraperitoneal injection of ACTH in rats]

Effects of ACTH on the content of 5-HT in the hippocampus, midbrain-pons, and spinal cord and the concentration of blood glucose in rats by spectrofluorometric assay and glucose oxidase method were studied. ACTH ip 10 IU.kg-1 or 20 IU.kg-1 significantly increased the content of 5-HT in the hippocampus, midbrain-pons and spinal cord and blood glucose level, both in a dose-dependent manner; para-chloroaphetamine, p-Cpa 4 mg icv markedly reduced the 5-HT in these brain regions and spinal cord and the blood glucose level (P less than 0.01); the level of 5-HT and blood glucose were not significantly altered after icv p-Cpa+ip ACTH; adrenalectomy+ip ACTH markedly increased the 5-HT content in the brain regions and spinal cord, but the blood glucose was decreased (P less than 0.01); and 5-HT was markedly decreased by sc alloxan tetrahydrate+ip ACTH, but blood glucose did not decrease (P greater than 0.05). Thus, ACTH may influence the blood glucose level through central nervous system 5-HT, and the change of 5-HT may be related to the insulin (secretion).

[Relation between changes in monoamine transmitters and brain edema after thermal burns in rats]

The HPLC with electro-chemical detector was employed to determine the change in monoamine transmitters and their metabolites murine hypothalamus, brainstem and spinal cord after burn. Also the pathological changes after burn in three brain parts was observed with photomicrograph and electromicrograph. The results show that: the monoamine contents were increased remarkably 5 min after burn, and even 360 min after burn, the monoamine contents were still higher than before the burn. The changes however, were different in the three brain parts. Edema appeared 5 min after burn in the three parts, and it was more evident in the hypothalamus. After icv phentolamine and CPA, edema was decreased. These results suggest that brain edema after thermal burn is related to changes in monoamine transmitters of CNS, mediated by receptor and 5-HT synthesis.

[Effect of intraventricular injection of somatostatin on pain threshold, and contents of the monoamines, xanthine, hypoxanthine in rats brain]

Using HPLC with electrochemical detection, we found that icv somatostatin (Som) 5 or 10 micrograms increased rat's pain threshold and contents of 5-HT and 5-HIAA in hippocampus, hypothalamus and brainstem, except the 5-HIAA content of brainstem in Som 5 micrograms group. However, the changes of NE among above three areas of brain were different, the NE contents of hypothalamus and brainstem significantly increased while that of hippocampus markedly decreased. After icv Som 20 micrograms, hypoxanthine and xanthine in hippocampus and hypothalamus decreased significantly, but encephaledema occurred. Som 40 micrograms icv caused necrotic changes of neurons in brain.

Observation of the phase transition in the growth of a biomineralized calcium carbonate

Transmission electron microscope studies of the cellular nucleation sites of a biomineralized calcium carbonate(aragonite) in the lamellar nacreous layer of the bivalvia Cristaria plicata (Leach) shell showed that the low density calcium particles were confined within some large vesicles of the bivalve mantle cells on which the crystalline aragonite phases were deposited. These vesicles served as the nucleation sites for the growth of the crystals. The crystalline phases at the first few lamellae were mostly imperfect while the whole nacreous layer acquitted itself into a highly oriented biomineralized aragonite. The structure of the vesicles is addressed in detail.

[Serotonin of hippocampus and hypothalamus taking part in the analgesic effect of adrenocorticotropic hormone in rats]

The effects of ip intra-PAG injection of ACTH on serotonin (5-HT), norepinephrine (NE) contents of hippocampus and hypothalamus and pain threshold were investigated. The results showed: (1) After ip ACTH, the pain threshold, the contents of 5-HT of the two brain regions and the NE content of hippocampus were markedly elevated. Prior destruction of periaqueductal gray (PAG), the elevation of pain threshold and the increase of the 5-HT contents of two brain regions due to ip ACTH were completely abolished, while the effect of ACTH in elevating NE content of hippocampus still persisted. (2) After intra-PAG injection of ACTH, the pain threshold and the 5-HT contents in hippocampus and hypothalamus were significantly increased, however, the NE levels in hippocampus and hypothalamus showed no significant changes. The analgesic effect of the intra-PAG injection of ACTH was prevented by icv LSD, but not by naloxone, atropine, hexamethonium and phentolamine. (3) After icv ACTH, the pain threshold did not change. These results suggest that the serotoninergic system may be activated by PAG for mediation of ACTH-induced analgesia.

[Thoracoscopy using flexible fiberoptic bronchoscopy--a preliminary report of experimental and clinical studies]

The preliminary experience on thoracoscopy with fiberoptic bronchoscope through a trocar designed by the authors for the purpose of studying its diagnostic implication and safety was reported. Structures in the pleural cavity of 8 dogs, being examined for 16 times, could be clearly perceived and taken for biopsy with exact localization. This technique was also carried out in 5 patients suffering from pleural effusion, mediastinal mass and periphery lung disease of unknown cause. After the examination, diagnosis was made as mesothelioma in 2 cases and non-specific pleurisy, malignant lung tumor with mediastinal lymphatic node metastasis and pulmonary benign tumor in the remaining 3 cases respectively. It was observed that its respiratory and circulatory effects were negligible as there were only transient fever in all the cases and local subcutaneous emphysema in one case with prompt recovery without treatment. Thoracoscopy is a technique easy to operate, safe, less traumatic and gives accurate diagnosis in clinical practice.

Paraplegia caused by local spinal cord ischemia. An animal spinal cord ischemia model

Local spinal cord ischemia model was established in 11 adult dogs. The anterior spinal artery, posterior spinal artery and radicular artery were cauterized with bipolar cautery. Ischemia of this segment of spinal cord was thus produced followed by paraplegia. The pathological findings of this spinal cord segment were softening and necrosis. The establishment of this animal model of segmental spinal cord ischemia is beneficial to scientific research in basic medicine and clinical practice.