Quantitative proteomics approach for identifying protein–drug interactions in complex mixtures using protein stability measurements

Knowledge about the protein targets of therapeutic agents is critical for understanding drug mode of action. Described here is a mass spectrometry-based proteomics method for identifying the protein target(s) of drug molecules that is potentially applicable to any drug compound. The method, which involves making thermodynamic measurements of protein-folding reactions in complex biological mixtures to detect protein–drug interactions, is demonstrated in an experiment to identify yeast protein targets of the immunosuppressive drug, cyclosporin A (CsA). Two of the ten protein targets identified in this proof of principle work were cyclophilin A and UDP-glucose-4-epimerase, both of which are known to interact with CsA, the former through a direct binding event (K_d ∼ 70 nM) and the latter through an indirect binding event. These two previously known protein targets validate the methodology and its ability to detect both the on- and off-target effects of protein–drug interactions. The other eight protein targets discovered here, which include several proteins involved in glucose metabolism, create a new framework in which to investigate the molecular basis of CsA side effects in humans.     

Giant Mesenteric Lipoma As an Unusual Cause of Abdominal Pain: A Case Report and a Review of the Literature

We report a rare case of giant mesenteric lipoma presenting with colicky abdominal pain. A 29-yr-old woman underwent laparoscopic resection for a giant mesenteric lipoma causing compression of the ileal loop. The resected ileal segment was encased by a giant fatty tissue, and normal mucosal fold patterns of the resected ileum were effaced by the mass. Microscopically, the mass was characterized by homogenous mature adipose tissue without cellular atypia, which was compatible with the diagnosis of a mesenteric lipoma. Despite the benign nature of this tumor, total excision with or without the affected intestinal loop should be considered if intestinal symptoms such as abdominal pain are present.     

The effect of anesthetic techniques on neutrophil-to-lymphocyte ratio after laparoscopy-assisted vaginal hysterectomy

BackgroundSurgical stress can induce postoperative systemic leukocytic alterations, including leukocytosis, neutrophilia, or lymphopenia. The present study investigated whether the anesthetic technique could affect the leukocytic alterations, including neutrophil-to-lymphocyte (N/L) ratio, after gynecologic laparoscopy.MethodsForty patients scheduled for laparoscopy-assisted vaginal hysterectomy were randomly assigned into two groups: PR group, which received total intravenous anesthesia with propofol and remifentanil, and S group, which received inhalational anesthesia with sevoflurane. Differential counts of leukocytes with N/L ratio of peripheral blood were obtained just before induction (T1), at the end of surgery (T2), 2 hours after surgery (T3), and 24 hours (T4) after surgery.ResultsSignificant increase in total leukocytic count, neutrophil count, and N/L ratio, and decrease in lymphocytic count were observed at all time points after surgery in both groups. N/L ratio was significantly lower in group PR compared with group S at T3. The increase of N/L ratio in contrast to the value at T1 was significantly lower at T2 and T3 in group PR compared with that of group S.ConclusionTotal intravenous anesthesia with propofol and remifentanil resulted in transient but salient leukocytic alterations in the peripheral blood in terms of N/L ratio compared with inhalational anesthesia with sevoflurane in laparoscopy-assisted vaginal hysterectomy.     

A kinematic analysis of relative stability of the lower extremities between subjects with and without chronic low back pain

Even though a number of studies have evaluated postural adjustments based on kinematic changes in subjects with low back pain (LBP), kinematic stability has not been examined for abnormal postural responses during the one leg standing test. The purpose of this study was to evaluate the relative kinematic stability of the lower extremities and standing duration in subjects with and without chronic LBP. In total, 54 subjects enrolled in the study, including 28 subjects without LBP and 26 subjects with LBP. The average age of the subjects was 37.8 ± 12.6 years and ranged from 19 to 63 years. The outcome measures included normalized holding duration and relative kinematic stability. All participants were asked to maintain the test position without visual input (standing on one leg with his/her eyes closed and with the contra lateral hip flexed 90°) for 25 s. The age variable was used as a covariate to control confounding effects for the data analyses. The control group demonstrated significantly longer holding duration times (T = −2.78, p = 0.007) than the LBP group (24.6 ± 4.2 s vs. 20.5 ± 6.7 s). For the relative kinematic stability, there was a difference in dominance side (F = 9.91, p = 0.003). There was a group interaction between side and lower extremities (F = 11.79, p = 0.001) as well as an interaction between age and dominance side (F = 7.91, p = 0.007). The relative kinematic stability had a moderate negative relationship with age (r = −0.60, p = 0.007) in subjects without LBP. Clinicians need to understand the effects of age and relative stability, which decreased significantly in the single leg holding test, in subjects with LBP in order to develop effective rehabilitation strategies.     

Characteristics of delayed hemorrhage after endoscopic sphincterotomy

Background and Aims: Hemorrhage is one of the most common complications associated with endoscopic sphincterotomy (EST). Although most hemorrhage occurs immediately after EST, delayed hemorrhage may occur, even several days after EST. We analyzed the incidence, clinical features, treatment and risk factors for delayed hemorrhage following EST. Methods: The medical records of 1549 patients who underwent EST between January 2000 and December 2006 were reviewed retrospectively. Delayed hemorrhage was defined as hemorrhage that developed 24 h after EST. Results: Of the 1549 patients who underwent EST, early hemorrhage during the procedure occurred in 45 patients (2.9%) and delayed hemorrhage occurred in 20 patients (1.3%). The time interval between EST and delayed hemorrhage was 4.8 ± 3.2 days (range, 1–15 days). Major hemorrhage developed in 80% of the patients with delayed hemorrhage. The mean decrease of hemoglobin was 3.5 ± 1.9 g/dL. The presenting symptoms of delayed hemorrhage included melena (80%), postural hypotension (80%), resting tachycardia (45%) and acute cholangitis (20%). All bleeding was successfully controlled by endoscopic treatment. Based on multivariate analysis, chronic kidney disease (CKD), hypertension and ischemic heart disease (IHD) were significant risk factors for delayed hemorrhage. Conclusion: Complete control of intra‐procedural bleeding is an important step in the prevention of late post‐EST hemorrhage. Careful observation for delayed hemorrhage after EST, especially in patients with CKD, hypertension and IHD, is recommended.     

Engineering of a human kringle domain into agonistic and antagonistic binding proteins functioning in vitro and in vivo

Here, we report the development of target-specific binding proteins based on the kringle domain (KD) (∼80 residues), a ubiquitous modular structural unit occurring across eukaryotic species. By exploiting the highly conserved backbone folding by core residues, but using extensive sequence variations in the seven loop regions of naturally occurring human KDs, we generated a synthetic KD library on the yeast cell surface by randomizing 45 residues in the loops of a human KD template. We isolated KD variants that specifically bind to anticancer target proteins, such as human death receptor 4 (DR4) and/or DR5, and that function as agonists to induce apoptotic cell death in several cancer cell lines in vitro and inhibit tumor progression in mouse models. Combined treatments with KD variants possessing different recognition sites on the same target protein exerted synergisitic tumoricidal activities, compared to treatment with individual variants. In addition to the agonists, we isolated an antagonistic KD variant that binds human tumor necrosis factor-α (TNFα) and efficiently neutralizes TNFα-induced cytotoxicity in vitro and in vivo. The KD scaffold with seven flexible loops protruding from the central core was strongly sequence-tolerant to mutations in the loop regions, offering a potential advantage of distinct binding sites for target recognition on the single domain. Our results suggest that the KD scaffold can be used to develop target-specific binding proteins that function as agonists or antagonists toward given target molecules, indicative of their potential use as biotherapeutics.     

Loss of Distal Femur Combined with Popliteal Artery Occlusion: Reconstructive Arthroplasty Using Modular Segmental Endoprosthesis: A Case Report

Severe injury to the knee and the surrounding area is frequently associated with injury to ligaments of the knee joint and structures in the popliteal fossa. This case involved a popliteal artery occlusion, severe bone loss of distal femur, loss of collateral ligaments, and extensor mechanism destruction of the knee. Initially, prompt recognition and correction of associated popliteal artery injury are important for good results after treatment. After successful revascularization, treatment for severe bone loss of distal femur and injury of the knee joint must be followed. We treated this case by delayed reconstruction using modular segmental endoprosthesis after revascularization of the popliteal artery. This allowed early ambulation. At 36 months after surgery, the patient had good circulation of the lower limb and was ambulating independently.     

Second‐look endoscopy with thermal coagulation or injections for peptic ulcer bleeding: A meta‐analysis

Background and Aims: In the management of peptic ulcer bleeding, the benefits of second‐look endoscopic treatment with thermal coagulation or injections in controlling recurrent bleeding is unsure. This study set out to compare efficacy of routine second‐look endoscopy with treatment using either thermal coagulation or injections versus single endoscopy by pooling data from published work. Methods: Full publications in the English‐language published work as well as abstracts in major international conferences were searched over the past 10 years, and six trials fulfilling the search criteria were found. Outcome measurements included: (i) recurrent bleeding; (ii) requirement of surgical intervention; and (iii) mortality. We examined heterogeneity of trials and pooled the effects by meta‐analysis. The quality of studies was graded according to the prospective randomization, methods of patient allocation, the list of exclusion criteria, outcome definitions and the predefined salvage procedures for uncontrolled bleeding. Results: Among 998 patients recruited in these five randomized trials, 119 received routine second‐look endoscopy with thermal coagulation, and 374 received second‐look with endoscopic injection and 505 had single endoscopic therapy. Less recurrent bleeding was reported after thermal coagulation (4.2%) than single endoscopy (15.7%) (relative risk [RR] = 0.29; 95% confidence interval [CI] = 0.11–0.73), but no reduction was reported for the requirement of surgical intervention and all‐cause mortality. Injection therapy did not reduce re‐bleeding (17.6%) when compared to single endoscopy (20.8%; RR = 0.85; 95% CI = 0.63–1.14), requirement for surgery and mortality. Conclusion: Routine second‐look endoscopy with thermal coagulation, but not injection therapy, reduced recurrent peptic ulcer bleeding. There is no proven benefit in reducing surgical intervention and overall mortality.