Clinical course of asymptomatic deep vein thrombosis after total knee arthroplasty in Japanese patients.

PURPOSE: The purpose of the present study was to follow up Japanese patients with deep vein thrombosis (DVT) after total knee arthroplasty (TKA) and also to examine factors associated with residual thrombus within the sixth postoperative month. METHODS: DVT evaluation was performed by noninvasive venous ultrasonography. We retrospectively reviewed 88 Japanese patients (88 knees) receiving primary unilateral TKA, who had no preoperative DVT. We examined the influence of the following four factors on postoperative DVT: (1) patient factors (age, sex, body height, body weight, and body mass index), (2) surgical factors (operation time, bleeding amount, avascularization time, and anesthesia method), (3) postoperative factors (bleeding amount, period to ambulation, period of venous foot pump use, and ratio of graduated compression stocking use), and (4) DVT conditional factors (location, length, number of vein branches, and the presence of >5 mm vasodilatation). RESULTS: The total prevalence of venous thromboembolism (VTE) was 62.5% (55 of the 88 patients). Among the 55 VTE patients, the rates of distal and proximal DVT were 96.4% and 3.6%, respectively. Bilateral DVT was found in 34.5%, while unilateral DVT on the surgical and nonsurgical sides were 52.7% and 12.7%, respectively. Asymptomatic pulmonary embolism was 1.8%. DVT was exacerbated in five patients (11.9%), of whom three showed additional thrombus formation. The remaining two patients had thrombus elongation or propagation from distal to proximal veins. In comparisons between thrombus-unresolved and -resolved groups within the sixth postoperative month, statistical significances were found in the incidence of bilateral DVT (50.0% vs. 15.4%, p = 0.02) and unilateral DVT (43.8% vs. 76.9%, p = 0.02). On the other hand, operation time (107.0 ± 17.3 min vs. 94.5 ± 11.9 min, p = 0.01) and avascularization time (99.8 ± 17.6 min vs. 88.0 ± 11.5 min, p = 0.01) in bilateral DVT patients were significantly longer than in unilateral ones. CONCLUSION: Our results suggest that an extended operation and avascularization time may be a risk factor for bilateral DVT and residual thrombus over 6 months.

Skin perfusion pressure measurement to assess improvement in peripheral circulation after arterial reconstruction for critical limb ischemia.

AIM: To assess the utility of skin perfusion pressure (SPP) measurement in evaluating the outcome of vascular constructions for critical limb ischemia (CLI) patients. METHODS: We retrospectively studied 19 lower limbs in 18 patients who underwent arterial reconstruction for CLI from whom SPP measurements had been obtained pre- and postoperatively between 2008 and 2010. Six limbs whose ulcers had healed postoperatively were classified into group H, 7 limbs whose ulcers had not healed into group U, and 6 limbs without ulcers into group N. SPP values were compared among these groups. RESULTS: The preoperative SPP values in all groups were <30 mmHg, without significant differences among the groups. The SPP values in groups H and N significantly improved after operation, and those in group U were significantly lower than those in the other groups. CONCLUSIONS: SPP measurement before and after arterial reconstruction is useful to assess improvement in tissue circulation and to predict the likelihood of wound healing. An SPP value ≥30 mmHg was considered necessary for wound healing, supporting the findings of the few reports in the literature on the usefulness of SPP for assessing vascular reconstruction effects on ulcer wound healing.

Skin Perfusion Pressure is a Useful Tool for Evaluating Outcome of Ischemic Foot Ulcers with Conservative Therapy.

OBJECTIVES: This study intended to confirm whether skin perfusion pressure (SPP) could predict the outcome of ischemic wound healing. PATIENTS AND METHODS: Sixty-two limbs in 53 patients with conservative therapy were enrolled in this study. A SPP value of 40 mmHg was adopted as the criterion for making clinical decisions. The outcome one month after SPP measurement was classified as "improved" (diameter of ulcer decreased ≥ 20% or demarcation of gangrene became well defined) or "no change or worse" (others), and the fate of wound was classified as "healed" or "not healed". The evaluated influential factors on the outcome at one month included age, sex, presence of arteriosclerosis obliterans, collagen disease, hypertension, diabetes mellitus, hemodialysis, wound infection, wound management, and SPP ≥ 40 mmHg. RESULTS: Using a criterion of SPP ≥ 40 mmHg, the outcome at one month could be predicted with a sensitivity: of 75.0%, a specificity: of 82.6%, and an accuracy: of 80.6%. The receiver operating characteristic curve indicated our criterion to be appropriate. Logistic regression analysis showed SPP ≥ 40 mmHg to be an independent factor (P < 0.0001) with the odds ratio of 14.2 (95% CI 3.6-55.8). CONCLUSIONS: SPP, using a cutoff value of 40 mmHg, can predict the ischemic wound healing with conservative therapy.

An ingenious design for peptide vaccines.

For humoral immunization, it may be possible to make effective and safe peptide vaccines for various diseases by selection of proper B-cell epitopes. However, a lack of T-cell epitopes on short peptides, such as those associated with major histocompatibility complex (MHC)-restriction, is a major problem for peptide vaccine development. We propose a solution for the design of peptide vaccines that involves induction of broadly reactive T-cell epitopes via agretopes. The strategy involves positioning multi-agretope type peptides on the N-terminal side of a di-lysine linker and B-cell epitopes on the C-terminal side. The addition of the arginine-glysine-aspartate (RGD)-motif to the N terminus of the peptide enhances its immunogenicity, and enables nasal immunization without adjuvants.

RGD motif enhances immunogenicity and adjuvanicity of peptide antigens following intranasal immunization.

The use of peptides for various aspects of medical science has been a significant advance. Peptide-based vaccines are promising, but weak immunogenic potency is impeding the clinical application. We have remarkably enhanced the immunogenicity of peptide antigens by addition of motifs that bind to cell attachment proteins, such as arginine-glysine-aspartate (RGD), to the amino acid sequence. The modified peptides induced antigen-specific serum antibodies by intranasal immunization without adjuvants. RGD, an integrin-binding motif was the strongest, among several molecules tested in this experiment, giving an average of 10 times enhancement of antibody titers when incorporated into several peptide antigens. The peptides also acted as an efficient adjuvant following the intranasal immunization with protein antigens. Our data support the feasibility of developing peptide vaccines and peptide adjuvants for intranasal vaccination.