Scaphoid nonunion reconstructed with vascularized bone-grafting pedicled on 1,2 intercompartmental supraretinacular artery and external fixation

BACKGROUND

Vascularized bone-grafting pedicled on 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) has been recommended as a treatment alternative for established scaphoid nonunion complicated with proximal pole avascular necrosis (AVN). Previous reports focused the studies on the union rate and the revascularization of the transferred graft. However, the postoperative wrist stiffness still a challenging problem and remaining to be solved. The purpose of our study was to determine whether the combination of vascularized bone-grafting pedicled on 1,2 ICSRA and wrist external fixator immobilization provides a more effective strategy for treating established scaphoid nonunion complicated with AVN and improving postoperative range of motion (ROM) of the injured wrist.

PATIENTS AND METHODS

We retrospectively reviewed a consecutive series of 11 patients who had cases of established scaphoid nonunion involving AVN of the proximal pole were treated with vascularized bone-grafting pedicled on 1,2 1,2 ICSRA, internal fixation, and wrist external fixator immobilization. Procedure of wrist arthrolysis was performed before vascularized bone graft transferring. Preoperative and postoperative evaluation included measurement of clinical (wrist ROM and grip strength), radiographic (intrascaphoid angle, scapholunate angle) and functional (Mayo wrist score) parameters.

RESULTS

Osseous union was achieved in all of the 11 cases within an average period of 11.4 weeks. On an average 6.1 years follow-up, there were three excellent, six good and two fair results. Significant improvements were found for Mayo wrist score, wrist ROM, and grip strength (p < 0.01). Intrascaphoid angle and scapholunate angle were significantly improved postoperatively, and there was no significant difference between the postoperative values and the values at the last follow-up. Early functional rehabilitation of the injured wrist under the protection of the fixator did not result in displacement of the transferred graft.

CONCLUSIONS

The results of the present investigation support the use of the vascularized bone graft pedicled on 1,2 ICSRA in the treatment of scaphoid nonunion complicated with proximal pole AVN. Procedures of wrist arthrolysis and early institution of wrist functional rehabilitation under the protection of the external fixator play important role in the restoration of range of motion of the injured wrist.  

A comparison of the thresholding strategies of micro-CT for periodontal bone loss: a pilot study

OBJECTIVES

Micro-CT provides three-dimensional details and has been widely used for biomedical assessments. This study aimed to determine the most appropriate threshold method for quantitatively assessing the dynamics of periodontal destruction.

METHODS

Inflammation was induced by submerging a silk ligature in the sulcus of the maxillary second molars of rats, and the animals were killed prior to ligature placement and after 7 and 21 days. The maxillae were examined for the bone resorptive activities by micro-CT, histology and tartrate-resistant acid phosphatase staining. The imaging threshold was determined by CT phantom, global and local algorithms. A bone fraction measurement from each threshold-determining technique was compared with histomorphometry. The reliability and reproducibility were examined by the intraclass correlation coefficient (ICC) and the coefficient of variation.

RESULTS

Significant reduction of inflammatory infiltration (p < 0.01) and active osteoclastic resorption (p < 0.05) from Day 7 to Day 21 were noted. High inter- and intraexaminer agreement were demonstrated in both histomorphometric and micro-CT assessments (ICC > 0.98). The algorithm-based technique demonstrated stronger correlation to histomorphometry than phantom-based thresholds, and the highest agreement was presented by the local algorithm (ICC > 0.96). This, however, was considerably computationally expensive.

CONCLUSIONS

The local threshold-determining algorithm is suggested for examining inflammation-induced bone loss. Further investigation will be aimed at enhancing computational efficiency.

The diagnostic value of a multivariate logistic regression analysis model with transvaginal power Doppler ultrasonography for the prediction of ectopic pregnancy

OBJECTIVE

A multivariate logistic regression analysis model for predicting ectopic pregnancy in women with pregnancy of unknown location was designed and evaluated clinically.

METHODS

Endometrial thickness, symmetry, resonance, pattern of echogenicity, helicine artery blood flow and blood flow resistance index (RI) in 129 patients with suspected early ectopic pregnancy were assessed by transvaginal power Doppler ultrasonography. Variables significant in univariate logistic regression analysis were included in a multivariate predictive logistic regression analysis model.

RESULTS

The final predictive model included three factors: endometrial thickness≤9 mm; a multilayered endometrial echogenicity pattern with prominent outer and midline hyperechogenic lines and an inner hypoechogenic region; and visible endometrial arterial blood flow. The area under the receiver operating characteristic curve of the model was 0.980. When RI was >0.65 and the predictive probability>0.50, diagnostic accuracy was high. The model correctly diagnosed 52/55 (94.5%) clinically confirmed ectopic pregnancy cases.

CONCLUSION

This multivariate predictive logistic regression analysis model has clinical value for the differential diagnosis of early ectopic pregnancy when the pregnancy location is unknown.

Traumatic forequarter amputation associated acute lung injury (ALI): report of one case

One case of traumatic forequarter amputation associated acute lung injury (ALI) was presented. A discussion reviewing the treatment guidelines for this devastating injury, and pointing out the importance of supporting the lung and preventing the development of acute respiratory distress syndrome (ARDS) was included.

Optimal ultrasonic array focusing in attenuative media

This paper presents a parametric study on the efficiency of ultrasound focusing in an attenuative medium, using phased arrays. Specifically, an analytical model of ultrasound wave focusing in a homogeneous, isotropic and attenuative fluid with point sources is presented. Calculations based on the model have shown that in an attenuative medium, an optimum frequency exists for the best focusing performance for a particular size of aperture and focal distance. The effect of different f numbers on the focusing performance in the attenuative medium is further investigated. The information obtained from the analytical model provides insights into the design and installation of a phased transducer array for energy efficient wave focusing.

Prospective assessment of C4d deposits on circulating cells and renal tissues in lupus nephritis: a pilot study

Complement activation plays a key role in the pathogenesis of lupus nephritis (LN), a severe complication of systemic lupus erythematosus (SLE). We prospectively evaluated 15 LN subjects and two control groups: 13 non-SLE renal subjects (control A) and 239 SLE subjects without LN (control B). All had C4d levels on circulating erythrocytes (E-C4d), reticulocytes (R-C4d) and platelets (P-C4d) measured by flow cytometry, while C4d deposition in renal tissue was semiquantitatively assessed in LN subjects and control A using immunoperoxidase staining. Compared with control A, LN biopsies had higher glomerular-C4d scores (p = 0.003), which were associated with more frequent granular glomerular immunofluorescence staining and electron dense deposits (p < 0.001). Compared with control A and B groups, LN subjects had higher E-C4d (p = 0.002 and p = 0.005) and R-C4d levels (p = 0.002 and p = 0.008), respectively. LN subjects were more likely to have P-C4d compared with control A (p = 0.016). In LN, only E-C4d correlated with National Institutes of Health (NIH) activity index (r = 0.55, p = 0.04). In conclusion, LN biopsies showed frequent glomerular-C4d staining associated with immune complex deposits. LN subjects had higher E-C4d and R-C4d levels compared with both control groups. E-C4d levels also correlated with NIH activity index. These findings suggest a potential role of C4d on circulating cells as a biomarker for lupus nephritis.

Enhancement of antitumor activity of the anti-EGF receptor monoclonal antibody cetuximab/C225 by perifosine in PTEN-deficient cancer cells

Mutational inactivation or deletion of the phosphatase and tensin homologue deleted on chromosome 10 (PTEN)/MMAC1/TEP gene in human cancer cells leads to a constitutively active status of the phosphatidylinositol 3-kinase/Akt pathway in the cells and has been linked to the lack of responses of the cells to the epidermal growth factor (EGF) receptor-targeted therapeutics. Akt is strongly inhibited by perifosine, an orally active alkyl-lysophospholipid currently being evaluated as an anti-cancer agent in phase 1 and 2 clinical trials. To determine whether perifosine may enhance the antitumor activity of the anti-EGF receptor monoclonal antibody cetuximab/C225 in PTEN-deficient cancer cells, we exposed MDA468 breast cancer cells (which contain mutated PTEN gene) and PC3 prostate cancer cells (in which the PTEN gene is deleted) to perifosine and cetuximab, alone and in combination. Treatment of the cells with perifosine reduced baseline levels of phosphorylated Akt, phosphorylated p44/42 mitogen-activated protein kinase (MAPK) and p38MAPK, and increased baseline levels of phosphorylated stress-activated protein kinase (SAPK)/c-jun NH(2)-terminal kinase (JNK). A 72-h exposure of the MDA468 and PC3 cells to perifosine alone resulted in cell death in a dose-dependent manner, which was enhanced by cetuximab. Addition of subtoxic doses of perifosine to cetuximab treatment also enhanced the cetuximab-induced growth inhibition. The combination treatment enhanced the inhibition of phosphorylation of Akt, p44/42MAPK and p38MAPK, but offset the phosphorylation of SAPK/JNK that was activated by perifosine treatment alone. Taken together, the data showed that perifosine enhances the antitumor activity of cetuximab in PTEN-deficient cancer cells. Further evaluation of the combination treatment in preclinical and clinical studies is warranted.

Palm print image recovery and de-noising via multi-channel wavelet filter bank

In this paper, a 3-channel wavelet transform method is introduced to recover palm print images following serious deformation. The deformation processing is actually a kind of digital re-sampling. A filter bank consisting of three filters is implemented for wavelet decomposition of the palm print image, and then a procedure of binary interpolation is performed after the image is reconstructed by another filter bank consisting of another three filters. The design of multi-channel wavelet filter bank is based on the Quadrature Mirror Filter (QMF) method. Because the noise is caused by the Morie stripe, the images are further de-noised after the geometry deformation is addressed. Acceptable results have been obtained.

HMG-CoA reductase inhibition reverses LCAT and LDL receptor deficiencies and improves HDL in rats with chronic renal failure

Dyslipidemia is a prominent feature of chronic renal failure (CRF) and a major risk factor for atherosclerosis and the progression of renal disease. CRF-induced dyslipidemia is marked by hypertriglyceridemia and a shift in plasma cholesterol from HDL to the ApoB-containing lipoproteins. Several studies have demonstrated a favorable response to administration of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors (statins) in CRF. This study was intended to explore the effect of statin therapy on key enzymes and receptors involved in cholesterol metabolism. Accordingly, CRF ( nephrectomized) and sham-operated rats were randomized to untreated and statin-treated (rosuvastatin 20 mg·kg−1·day−1) groups and observed for 6 wk. The untreated CRF rats exhibited increased total cholesterol-to-HDL cholesterol ratio, diminished plasma lecithin:cholesterol acyltransferase (LCAT) and the hepatic LDL receptor, elevated hepatic acyl-CoA:cholesterol acyltransferase (ACAT), and no change in hepatic HMG-CoA reductase, cholesterol 7α-hydroxylase, or HDL receptor (SRB-1). Statin administration lowered HMG-CoA reductase activity, normalized plasma LCAT, total cholesterol-to-HDL cholesterol ratio, and hepatic LDL receptor but did not significantly change either plasma total cholesterol, hepatic cholesterol 7α-hydroxylase, total ACAT activity, or SRB-1 in the CRF animals. Statin administration to the normal control rats led to significant increases in plasma LCAT and hepatic LDL receptor, significant reductions of total cholesterol-to-HDL cholesterol ratio, hepatic HMG-CoA reductase activity, and cholesterol 7α-hydroxylase abundance with virtually no change in plasma cholesterol concentration. Thus administration of rosuvastatin reversed LCAT and LDL receptor deficiencies and promoted a shift in plasma cholesterol from ApoB-containing lipoproteins to HDL in CRF rats.

Spectral integration in primary auditory cortex: Laminar processing of afferent input, in vivo and in vitro

Auditory cortex neurons integrate information over a broad range of sound frequencies, yet it is not known how such integration is accomplished at the cellular or systems levels. Whereas information about frequencies near a neuron's characteristic frequency is likely to be relayed to the neuron by lemniscal thalamocortical inputs from the ventral division of the medial geniculate nucleus, we recently proposed that information about frequencies spectrally distant from characteristic frequency is mainly relayed to the neuron via "horizontal" intracortical projections from neurons with spectrally-distant characteristic frequencies [J Neurophysiol 91 (2004) 2551]. Here we test this hypothesis by using current source density analysis to determine if characteristic frequency and spectrally-distant non-characteristic frequency stimuli preferentially activate thalamocortical and horizontal pathways, respectively, in rat auditory cortex. Characteristic frequency stimuli produced current source density profiles with prominent initial current sinks in layers 3 and 4--the termination zone of lemniscal inputs from medial geniculate nucleus. In contrast, stimuli three octaves below characteristic frequency produced initial current sinks mainly in the infragranular layers. Differences between current source density profiles were only apparent for initial current sinks; profiles for longer-latency current sinks evoked by characteristic frequency and non-characteristic frequency stimuli overlapped to a greater degree, likely due to shared mechanisms of intracortical processing or to longer-latency thalamocortical contributions (lemniscal and nonlemniscal). To identify current source density profiles produced by activation of lemniscal thalamocortical inputs alone, we utilized the mouse auditory thalamocortical slice preparation. Electrical stimulation of the medial geniculate nucleus in vitro produced major current sinks in cortical layers 3/4, and excitation spread horizontally from this point throughout primary auditory cortex to produce current sinks in multiple cortical layers. These data support the hypothesis that relay of thalamocortical information throughout auditory cortex via horizontal intracortical projections may be the basis of broad spectral integration in vivo.

Onset and rate of striatal atrophy in preclinical Huntington disease

BACKGROUND

Huntington disease (HD) is characterized by striatal atrophy that begins long before the onset of motor symptoms.

OBJECTIVE

To determine when striatal atrophy begins, the extent and rate of atrophy before diagnosis of motor symptoms, and whether striatal atrophy can predict when symptom onset will occur.

METHODS

Caudate and putamen volumes were measured on MRI scans of 19 preclinical subjects with the HD gene expansion who were very far (9 to 20 years) from estimated onset, and on serial scans from 17 preclinical subjects, six of whom were diagnosed with HD within 5 years after the initial scan.

RESULTS

Striatal volumes were significantly smaller for the subjects who were very far from estimated onset than for age-matched control subjects. Statistical models fit to the longitudinal data suggest that rate of caudate atrophy becomes significant when subjects are approximately 11 years from estimated onset and rate of putamen atrophy becomes significant approximately 9 years prior to onset. In the six incident cases, caudate and putamen were approximately one-third to one-half of normal volume at diagnosis, and caudate volume alone was able to predict with 100% accuracy those subjects who would be diagnosed within 2 years of imaging.

CONCLUSIONS

Striatal atrophy begins many years prior to diagnosable HD, and assessment of atrophy on MRI may be very useful in both predicting HD onset and in tracking progression in future therapeutic trials in preclinical subjects.

ACAT inhibition reverses LCAT deficiency and improves plasma HDL in chronic renal failure

Chronic renal failure (CRF) is associated with increased risk of arteriosclerotic cardiovascular disease and profound alteration of plasma lipid profile. Uremic dyslipidemia is marked by increased plasma concentration of ApoB-containing lipoproteins and impaired high-density lipoprotein (HDL)-mediated reverse cholesterol transport. These abnormalities are, in part, due to acquired LCAT deficiency and upregulation of hepatic acyl-CoA:cholesterol acyltransferase (ACAT). ACAT catalyzes intracellular esterification of cholesterol, thereby promoting hepatic production of ApoB-containing lipoproteins and constraining HDL-mediated cholesterol uptake in the peripheral tissues. In view of the above considerations, we tested the hypothesis that pharmacological inhibition of ACAT may ameliorate CRF-induced dyslipidemia. 5/6 Nephrectomized rats were treated with either ACAT inhibitor IC-976 (30 mg.kg(-1).day(-1)) or placebo for 6 wk. Sham-operated rats served as controls. Key cholesterol-regulating enzymes, plasma lipids, and creatinine clearance were measured. The untreated CRF rats exhibited increased plasma low-density lipoprotein (LDL) and very LDL (VLDL) cholesterol, unchanged plasma HDL cholesterol, elevated total cholesterol-to-HDL cholesterol ratio, reduced liver microsomal free cholesterol, and diminished creatinine clearance. This was accompanied by reduced plasma LCAT, increased hepatic ACAT-2 mRNA, ACAT-2 protein and ACAT activity, and unchanged hepatic HMG-CoA reductase and cholesterol 7alpha-hydroxylase. ACAT inhibitor raised plasma HDL cholesterol, lowered LDL and VLDL cholesterol, and normalized total cholesterol-to-HDL cholesterol ratio without changing total cholesterol concentration (hence, a shift from ApoB-containing lipoproteins to HDL). This was accompanied by normalizations of hepatic ACAT activity and plasma LCAT. In conclusion, inhibition of ACAT reversed LCAT deficiency and improved plasma HDL level in CRF rats. Future studies are needed to explore the efficacy of ACAT inhibition in humans with CRF.

Downregulation of hepatic acyl-CoA:diglycerol acyltransferase in chronic renal failure

Chronic renal failure (CRF) is associated with hypertriglyceridemia and elevated plasma VLDL and IDL concentrations. These events can be due to either increased production or depressed catabolism of triglyceride-rich lipoproteins. Several studies have documented downregulation of lipoprotein lipase, hepatic triglyceride lipase, and the VLDL receptor, leading to depressed clearance and elevated plasma concentration of triglyceride-rich lipoproteins and their remnants in CRF. However, the effect of CRF on the triglyceride biosynthetic pathway has not been explored. Diglycerol acyltransferase (DGAT) is a microsomal enzyme that joins acyl-CoA to 1,2 diacylglycerol and, as such, constitutes the final step in triglyceride biosynthesis. Two distinct forms of DGAT (DGAT-1 and -2) have thus far been identified. The present study was undertaken to examine the effect of CRF on DGAT gene expression and activity in the liver, which is the source of endogenous triglycerides in the circulation. Male Sprague-Dawley rats were studied 8 wk after 5/6 nephrectomy (CRF) or sham operation. DGAT-1 and DGAT-2 mRNA abundance and DGAT activity were quantified. The CRF group showed reduced creatinine clearance, elevated plasma triglycerides, and VLDL concentrations. This was accompanied by significant reductions in hepatic DGAT-2 mRNA abundance (P < 0.01) and total DGAT activity (P < 0.1), pointing to diminished hepatic triglyceride production capacity in CRF animals. In conclusion, CRF results in significant downregulation of hepatic DGAT gene expression and activity. Given the critical role of DGAT in triglyceride biosynthesis, the present study points to diminished, not increased, hepatic triglyceride synthetic capacity in CRF rats.

Roles of the PI-3K and MEK pathways in Ras-mediated chemoresistance in breast cancer cells

Activated Ras utilises several downstream pathways, including the mitogen-activated protein kinase (MAPK) kinase (MEK)/MAPK pathway and the phosphoinositide 3-kinase (PI-3k)/Akt pathway, to promote cell proliferation and to inhibit apoptosis. To investigate which pathway plays a major role in Ras-induced drug resistance to chemotherapeutic agents in breast cancer cells, we transfected MCF7 breast cancer cells with a constitutively active H-RasG12V and examined the toxicities of three commonly used breast cancer chemotherapeutic agents, paclitaxel, doxorubicin, and 5-fluorouracil in these cells under the conditions that PI-3K or MEK were selectively inhibited by their respective specific inhibitors or dominant negative expression vectors. We found that Ras-mediated drug resistance is well correlated with resistance to apoptosis induced by anticancer agents in MCF7 breast cancer cells. Although inhibition of MEK/MAPK or PI-3K/Akt can each enhance the cytotoxicity of paclitaxel, doxorubicin, or 5-fluorouracil, inhibition of the PI-3K/Akt pathway seems to have a greater effect than inhibition of the MEK/MAPK pathway in reversing Ras-mediated drug resistance. Our results indicate that the PI-3K pathway may play a more important role in receptor tyrosine kinase-mediated resistance to chemotherapy and suggest that PI-3K/Akt might be a critical target molecule for anticancer intervention in breast cancer.

[Differences of nitric oxide synthase expression and activity between splanchnic arterial and venous vessels of cirrhotic rats]

OBJECTIVE

To understand the implication of differences of nitric oxide synthase (NOS) expression and activity between splanchnic arterial and venous vessels in the pathogenesis of portal hypertension.

METHODS

Cirrhosis was induced in 100 Wistar rats by subcutaneously administration of carbon tetrachloride. NOS localization, activity and gene expression in the mesenteric artery and the portal vein vessels of both cirrhotic and normal rats were investigated by immunohistochemistry, chemoluminescence and reverse transcription-polymerase chain reaction, respectively.

RESULTS

There was inducible NOS enzyme isoform in al1 layers of splanchnic vessels of cirrhotic rats, whereas endothelial NOS isoform largely in vascular endothelia. NOS activity and its mRNA expression all were significantly increased in cirrhotic rats when compared with normal rats (P<0.05 or 0.01).Moreover, the activities of general and constitutive NOS and the expression of endothelial NOS mRNA in cirrhotic rats were significantly higher in the mesenteric artery than in the portal vein (P<0.01).

CONCLUSIONS

Enhanced expression and activity of endothelial NOS enzyme isoform may be mainly responsible for increased NO production of splanchnic vessels in cirrhotic rats, and the differences of NOS expression and activity between the mesenteric artery and the portal vein vessels may be one of the pathogeneses of portal hypertension in which NO might be involved.

Mechanisms of bradykinin-mediated Ca(2+) signalling in canine cultured corneal epithelial cells

Experiments were designed to differentiate the mechanisms of bradykinin receptors mediating the changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) in canine cultured corneal epithelial cells (CECs). Bradykinin and Lys-bradykinin caused an initial transient peak of [Ca(2+)](i) in a concentration-dependent manner, with half-maximal stimulation (pEC(50)) obtained at 6.9 and 7.1, respectively. Pretreatment of CECs with pertussis toxin (PTX) or cholera toxin (CTX) for 24 h did not affect the bradykinin-induced [Ca(2+)](i) changes. Application of Ca(2+) channel blockers, diltiazem and Ni(2+), inhibited the bradykinin-induced Ca(2+) mobilization, indicating that Ca(2+) influx was required for the bradykinin-induced responses. Addition of thapsigargin (TG), which is known to deplete intracellular Ca(2+) stores, transiently increased [Ca(2+)](i) in Ca(2+)-free buffer, and subsequently induced Ca(2+) influx when Ca(2+) was readded to this buffer. Pretreatment of CECs with TG completely abolished bradykinin-induced initial transient [Ca(2+)](i), but had slight effect on bradykinin-induced Ca(2+) influx. Pretreatment of CECs with 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole (SKF96365) and 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122) inhibited the bradykinin-induced Ca(2+) release and Ca(2+) influx, consistent with the inhibition of receptor-gated Ca(2+) channels and phospholipase C (PLC) in CECs, respectively. These results demonstrate that bradykinin directly stimulates B(2) receptors and subsequently Ca(2+) mobilization via a PTX-insensitive G protein in canine CECs. These results suggest that bradykinin-induced Ca(2+) influx into the cells is not due to depletion of these Ca(2+) stores, as prior depletion of these pools by TG has no effect on the bradykinin-induced Ca(2+) influx that is dependent on extracellular Ca(2+) in CECs.