Knee dislocation: treatment of high-velocity knee dislocation

BACKGROUND: We report the outcomes of patients treated with a new arthroscopic treatment modality for knee dislocation after high-velocity trauma. METHODS: Twenty-three patients (12 men, 11 women; 25 knees) with traumatic knee dislocation were treated with this technique. Under arthroscopy with gravity inflow irrigation, the ruptured posterior cruciate ligament was reconstructed with a patellar bone-tendon-bone graft, and the anterior cruciate ligament was debrided subacutely. The collateral ligament, meniscus, and capsules were repaired through additional incisions. RESULTS: The average interval between injury and surgery was 11.1+/-5 days (range, 5 to 25 days). After a mean follow-up period of 27.2+/-7.86 months, the mean extension was 1+/-2 degrees and the average flexion was 129.6+/-4.91 degrees. The mean Lysholm score was 84. There were no major complications. CONCLUSION: Arthroscopic posterior cruciate ligament reconstruction seems to be an effective treatment for traumatic knee dislocation.     

A genome-wide scan for a simulated data set using two newly developed methods

A genome-wide scan of a simulated data set for fictitious disease genes was conducted using both semiparametric and nonparametric methods. The semiparametric model-based method, which tests for linkage/linkage disequilibrium separately and together, correctly identified all three underlying disease loci along with two false positives through the linkage analysis. However, the nonparametric model-free method which tests combined linkage/linkage disequilibrium, failed to yield any results due to the lack of linkage disequilibrium information in the data.     

The spatial organization of apical junctional complex-associated proteins in feline and human corneal endothelium

PURPOSE: Previous studies suggest that proteins associated with the apical junctional complex (AJC) play essential roles in the development, maintenance and regulation of barrier function in transport epithelium and vascular endothelium. The goal of this study is to identify and determine the spatial organization of several major AJC-associated proteins in normal human and feline corneal endothelium. METHODS: Fresh corneal tissue was obtained from 4 recipient buttons removed during penetrating keratoplasty (two from keratoconus patients, and two from patients with post-traumatic stromal scarring) as well as from 16 cat eyes. En bloc double- and triple-labeling of corneas was performed using phalloidin, and mouse, rat or rabbit antibodies to ZO-1, occludin, pan-cadherin, alpha-catenin, beta-catenin and plakoglobin (gamma-catenin). The 3-D localization of the proteins was then determined in situ using laser confocal microscopy. RESULTS: Similar staining patterns were obtained for the corneal endothelium of normal cat corneas and fresh human buttons. Apically, f-actin was arranged into dense peripheral bands (DPB) in individual cells that were separated from those in adjacent cells. Diffuse phalloidin staining also extended from the DPB into the cytoplasm apically. Although weaker, phalloidin staining also appeared to be associated with the basolateral cell borders. The adherens junction protein, cadherin, formed a thin pericellular band at the apical cell junctions between the DPB. In addition, cadherin staining also appeared to extend along the basolateral cell borders in a convoluted pattern. Staining for alpha-catenin, beta-catenin and plakoglobin each showed a nearly identical organization as cadherin. ZO-1 formed a single apical band that was localized between the DPB; however, no basolateral ZO-1 staining was detected. Interestingly, the distribution of ZO-1 was discontinuous around the cell, with the largest gaps occurring at the Y-junctions between adjacent endothelial cells. Positive staining for occludin was not detected in either human or feline corneal endothelium. CONCLUSIONS: The composition and organization of the AJC of corneal endothelium appears to be different from that of classical transport epithelia; these findings may be related to functional differences between these two cell types.     

Effects of nonsteroidal anti-inflammatory drugs and prostaglandins on osteoblastic functions.

It has been reported that nonsteroidal anti-inflammatory drugs (NSAIDs) suppress bone repair and bone remodeling but only mildly inhibit bone mineralization at the earlier stage of the repair process. We proposed that the proliferation and/or the earlier stage of differentiation of osteoblasts may be affected by NSAIDs. This study was designed to investigate whether NSAIDs affect the proliferation and/or differentiation of osteoblasts and whether these effects are prostaglandin (PG) mediated. The effects of PGE1 and PGE2, indomethacin, and ketorolac on thymidine incorporation, cell count, intracellular alkaline phosphatase (ALP) activity, and Type I collagen content in osteoblast-enriched cultures derived from fetal calvaria were evaluated. The results showed that both PGs and NSAIDs inhibited DNA synthesis and cell mitosis in a time- and concentration-dependent manner. However, intracellular ALP activity and Type I collagen content were stimulated at an earlier stage of differentiation in osteoblasts. These results suggested that (i) the inhibitory effect of ketorolac on osteoblastic proliferation contributes to its suppressive effects on bone repair and remodeling in vivo; (ii) PGEs and NSAIDs may be involved in matrix maturation and biologic bone mineralization in the earlier stage of osteoblast differentiation; and (iii) the effects of ketorolac and indomethacin on cell proliferation and differentiation may not be through the inhibition of the synthesis of PGE1 or PGE2.     

CHO/hPEPT1 cells overexpressing the human peptide transporter (hPEPT1) as an alternative in vitro model for peptidomimetic drugs

The present study characterized Chinese hamster ovary cells overexpressing a human intestinal peptide transporter, CHO/hPEPT1 cells, as an in vitro model for peptidomimetic drugs. The kinetic parameters of Gly-Sar uptake were determined in three different cell culture systems such as untransfected CHO cells (CHO-K1), transfected CHO cells (CHO/hPEPT1) and Caco-2 cells. Vmax in CHO/hPEPT1 cells was approximately 3-fold higher than those in Caco-2 cells and CHO-K1 cells, while Km values were similar in all cases. The uptake of beta-lactam antibiotics in CHO/hPEPT1 cells was three to twelve fold higher than that in CHO-K1 cells, indicating that CHO/hPEPT1 cells significantly enhanced the peptide transport activity. However, amino acid drugs also exhibited high cellular uptake in both CHO-K1 and CHO/hPEPT1 cells due to the high background level of amino acid transporters. Thus, cellular uptake study in CHO/hPEPT1 cells is not sensitive enough to distinguish the peptidyl drugs from amino acid drugs. The potential of CHO/hPEPT1 cells as an in vitro model for peptidomimetic drugs was also examined through the inhibition study on Gly-Sar uptake. Peptidomimetic drugs such as beta-lactam antibiotics and enalapril significantly inhibited Gly-Sar uptake whereas the nonpeptidyl compounds, L-dopa and alpha-methyldopa, did not compete with Gly-Sar for cellular uptake within the therapeutic concentrations. In conclusion, the present study demonstrates the further characterization of CHO/hPEPT1 cells as an uptake model as well as inhibition study and suggests their utility as an alternative in vitro model for drug candidates targeting the hPEPT1 transporter.     

Functional expression of the bovine herpesvirus 1 alkaline deoxyribonuclease (UL12) inEscherichia coli

Summary Sequence analysis within the unique long segment of the bovine herpesvirus 1 (BHV-1; infectious bovine rhinotracheitis virus) genome identified an open reading frame whose deduced protein product of 487 amino acids exhibited homology to alkaline deoxyribonucleases (DNases) of other herpesviruses. To determine this BHV-1 gene product has nuclease activity, the gene designated UL12 was inserted into the vector pET-28a(+) and expressed inEscherichia coli as an oligohistidine-tagged protein. Upon induction with isopropyl -D-thiogalactopyranosideE. coli BL21 (DE3) [pLysS] cells carrying this recombinant plasmid produced a 57-kDa protein, the molecular mass of which was in accordance with the prediction from the DNA sequence. The recombinant UL12 protein purified by nickel-chelating affinity chromatography exhibited both exonuclease and endonuclease activity, each with an alkaline pH optimum.     

Persisting axonal degeneration in the hippocampus after transection of the fimbria-fornix

Degeneration within the hippocampus was examined at the light microscopic level using the Gallyas silver stain two, four or nine months after bilateral transection of the fimbria-fornix and commissural connections. At two or four months after the lesion the strata oriens and radiatum of the subicular end of the CA1 subfields were strongly argyrophilic as was the inner third of the molecular layer of the dentate gyrus. At nine months post-lesion argyrophilia diminished but clearly persisted in the same layers. Electron microscopic examination revealed a large number of electron-dense axon terminals in the argyrophilic areas, most of them making asymmetric synaptic contacts with dendritic spines. These findings suggest that at least a portion of the Schaffer collaterals of the CA3 pyramidal cells and associational collaterals of hilar neurons were in a process of acute degeneration at all time points after the initial surgical trauma. This persistent synaptic reorganization of intrahippocampal circuits may be related to abnormal electrical activity observed several months after fimbria-fornix transection.     

Accuracy of a rapid 10-minute carbon-14 urea breath test for the diagnosis of Helicobacter pylori-associated peptic ulcer disease

Urease in the human gastric mucosa is a marker for infection with Helicobacter pylori (HP), an organism which is associated with peptic ulcer disease. To detect gastric urease, we examined 184 patients (144 males, 40 females; mean age: 49.8±15.6 years) with suspected peptic ulcer disease. Fasting patients were given orally 5 Ci of carbon-14 labelled urea. From each patient only one breath sample was collected in hyamine at 10 min. The amount of ¹⁴C collected at 10 min was expressed as follows: [(DPM/mmol CO₂ collected)/(DPM administered)] × 100 × body weight (kg). The presence of HP colonization was determined by examination of multiple endoscopic prepyloric antral biopsy specimens subjected to culture or a rapid urease test. For the purpose of this study, HP-positive patients were defined as those with characteristic bacteria as indicated by a positive result of either the culture or the rapid urease test; HP-negative patients were defined as those with negative findings on both the culture and the rapid urease test. Of the 184 cases, 99 (53.8%) were positive for HP infection, and 85 (46.2%), negative. The sensitivity and specificity of the rapid 10 min ¹⁴C-urea breath test for the diagnosis of HP-associated peptic ulcer disease were evaluated by a receiver operating characteristic (ROC) curve with a variable cut-off value from 1.5 to 4.5. When a cut-off value of 1.5 was selected, the sensitivity was 100% and the specificity, 83.5%; when a cut-off value of 4.5 was selected, the sensitivity was 54.5% and the specificity, 97.6%. Correspondence to: Chia-Hung Kao     

Heterotopic ossification around the hip in spinal cord-injured patients. A long-term follow-up study.

Twenty patients with spinal cord injury complicated by ossification around the hip were followed for eighteen months or more. The bone scan, roentgenogram, level of alkaline phosphatase, and range of hip motion of each patient were analyzed. The average follow-up was forty months. The heterotopic ossification usually did not mature until after one and one-half years. The roentgenograms were of no value in judging its maturity. The bone scan correlated well with the results of the alkaline phosphatase testing in judging maturity of the ossification. We concluded that before operative resection, a patient should have a normal level of alkaline phosphatase, decreasing activity on the bone scans, and a restriction of motion to less than 50 degrees of hip flexion.     

Stability of Interleukin 1β (IL-1β) in Aqueous Solution: Analytical Methods,Kinetics, Products,and Solution Formulation Implications

The thermal stability of IL-1 in aqueous solution as a function of temperature (5–60°C), pH (2–9), buffer (acetate, citrate, tris, and phosphate), and cyroprotectants (sugars, HSA) was investigated in this study. The analytical methodologies included RP-HPLC, SEC, ELISA, IEF-PAGE, SDS-PAGE, and bioassay. The degradation and inactivation of IL-1 at or above 39°C were attributed to autoxidation of the two cysteine residues in the denatured protein, followed by hydrophobic/covalent aggregation and precipitation. At or below 30°C, IEF- and SDS-PAGE results suggest a possible deamidation reaction. The difference in mechanism of degradation precludes the prediction of formulation shelf life from accelerated temperature data. Nonetheless, the good stability observed at 5°C suggests that a solution formulation may be feasible for IL-1.