Risk prediction model for early outcomes of revascularization for chronic limb-threatening ischaemia.

BACKGROUND: Quantifying the risks and benefits of revascularization for chronic limb-threatening ischaemia (CLTI) is important. The aim of this study was to create a risk prediction model for treatment outcomes 30 days after revascularization in patients with CLTI. METHODS: Consecutive patients with CLTI who had undergone revascularization between 2013 and 2016 were collected from the JAPAN Critical Limb Ischemia Database (JCLIMB). The cohort was divided into a development and a validation cohort. In the development cohort, multivariable risk models were constructed to predict major amputation and/or death and major adverse limb events using least absolute shrinkage and selection operator logistic regression. This developed model was applied to the validation cohort and its performance was evaluated using c-statistic and calibration plots. RESULTS: Some 2906 patients were included in the analysis. The major amputation and/or mortality rate within 30 days of arterial reconstruction was 5.0 per cent (144 of 2906), and strong predictors were abnormal white blood cell count, emergency procedure, congestive heart failure, body temperature of 38°C or above, and hemodialysis. Conversely, moderate, low or no risk in the Geriatric Nutritional Risk Index (GNRI) and ambulatory status were associated with improved results. The c-statistic value was 0.82 with high prediction accuracy. The rate of major adverse limb events was 6.4 per cent (185 of 2906), and strong predictors were abnormal white blood cell count and body temperature of 38°C or above. Moderate, low or no risk in the GNRI, and age greater than 84 years were associated with improved results. The c-statistic value was 0.79, with high prediction accuracy. CONCLUSION: This risk prediction model can help in deciding on the treatment strategy in patients with CLTI and serve as an index for evaluating the quality of each medical facility.

Clinical outcomes after infrainguinal bypass grafting for critical limb ischaemia in patients with dialysis-dependent end-stage renal failure.

OBJECTIVE: To assess and risk-stratify the medium-term clinical outcomes after infrainguinal bypass grafting (IBG) to treat critical limb ischaemia (CLI) in patients with end-stage renal disease. METHODS: This was a retrospective single-centre study. Between April 2007 and March 2011, 112 limbs from 89 patients were studied. In particular, amputation-free survival (AFS), 30 day mortality, freedom from major adverse limb events (MALE), limb salvage, and overall survival were examined. The aim was to identify outcome predictors. RESULTS: Eight patients (9%) died within 30 days of IBG. The only positive predictor of 30-day mortality was an ejection fraction (EF) < 40% (hazard ratio [HR] 5.57, 95% confidence interval [CI] 1.16-26.83; p = .03). The mean follow-up duration was 14 months. The 1- and 2-year AFS rates were 64% and 43%, respectively, and the rates of freedom from MALE were 81% and 77%, respectively. In addition, the 1- and 2-year limb salvage rates were 89% and 85%, and the survival rates were 68% and 50%, respectively. Non-ambulatory status was negatively associated with AFS (HR 3.04, 95% CI 1.59-5.82; p < .01), freedom from MALE (HR 4.98, 95% CI 1.91-12.96; p < .01), and limb salvage (HR 5.18, 95% CI 1.47-18.30; p = .01). The other negative predictors of overall survival were a serum albumin level <3.0 g/dL (HR 2.26, 95% CI 1.12-4.58; p = .02) and an EF <40% (HR 2.24, 95% CI 1.05-4.79; p = .04). CONCLUSION: Patients with CLI on dialysis enjoyed satisfactory freedom from MALE and limb salvage, but survival and AFS were significantly less than reported for IBG in patients with CLI who did not receive dialysis. In addition, patients with an EF <40%, lower serum albumin (<3.0 g/dL), or non-ambulatory status experienced particularly poor clinical outcomes after IBG.

Processing of CD109 by furin and its role in the regulation of TGF-beta signaling.

CD109 is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein, whose expression is upregulated in squamous cell carcinomas of the lung, esophagus, uterus and oral cavity. CD109 negatively regulates transforming growth factor (TGF)-beta signaling in keratinocytes by directly modulating receptor activity. In this study, we further characterized CD109 regulation of TGF-beta signaling and cell proliferation. We found that CD109 is produced as a 205 kDa glycoprotein, which is then processed in the Golgi apparatus into 180 kDa and 25 kDa proteins by furin (furinase). 180 kDa CD109 associated with GPI-anchored 25 kDa CD109 on the cell surface and was also secreted into the culture medium. To investigate whether furinase cleavage of CD109 is necessary for its biological activity, we mutated arginine 1273 in the CD109 furinase cleavage motif (amino acid 1270-RRRR-1273) to serine (R1273S). Interestingly, CD109 R1273S neither significantly impaired TGF-beta signaling nor affected TGF-beta-mediated suppression of cell growth, although it was expressed on the cell surface as a 205 kDa protein. Consistent with this finding, the 180 kDa and 25 kDa CD109 complex, but not CD109 R1273S, associated with the type I TGF-beta receptor. These findings indicate that processing of CD109 into 180 kDa and 25 kDa proteins by furin, followed by complex formation with the type I TGF-beta receptor is required for the regulation of TGF-beta signaling in cancer cells and keratinocytes.

Development of a method to analyze single cell activity by using dielectrophoretic levitation.

In cell fusion and genetic recombination, although the activity of single cells is extremely important, there is no method to analyze single cell activity. Development of a quick analyzing method for single cell activity is desired in various fields. Dielectrophoresis (DEP) refers to the force exerted on the induced dipole moment of an uncharged dielectric and/or conductive particle by a nonuniform electric field. By applying DEP, we obtained experimentally a relationship between the cell activity and the dielectric property, Re[K(omega)], and examined how to evaluate the single cell activity by measuring Re[K(omega)] of a single cell. A cone and plate electrode geometry was adapted in order to achieve the feedback-controlled DEP levitation. The single cell is exposed to a nonuniform field induced by the cone and plate electrode, and a more polarizable cell is moved to the direction of the cone electrode by the DEP force. The cell settles in the position where the DEP force and gravity are balanced by controlling applied voltage. This settled position, measured on the center axis of the cone electrode, depended on the dielectric constant of the cell. From these results, the relationship between the specific growth rates in cell growth phase and the dielectric properties Re[K(omega)] was obtained. Furthermore, the effect on the cell activity of various stresses, such as concentration of carbon dioxide, temperature, etc., was examined.

Sensory nerve-dominant nerve degeneration and remodeling in the mutant mice lacking complex gangliosides.

Gangliosides, sialic acid-containing glycosphingo-lipids, are enriched in the mammalian nervous system. Since mutant mice with disrupted beta1,4-N-acetylgalactosaminyl-transferase (GM2/GD2 synthase) were generated, there have been several studies on the pathology of the mutant mice, i.e. mild functional disorders and Wallerian degeneration in the peripheral nervous system. To further analyze the chronological alteration in the mutant mice, we examined the peripheral and CNS mainly with morphological approaches, such as electron microscopy and immunohistochemistry. Accordingly with the sensory dysfunction, neural degeneration, glial proliferation and synaptic remodeling in the dorsal horn of the spinal cord were found in adult mice. Thick astrocytic processes with densely packed glial filaments were extended among the neuropils and around blood vessels. Morphological changes in the synaptic vesicles and modes of synaptic contacts with central terminals were detected, suggesting synaptic remodeling following the degeneration. These results suggest that complex gangliosides are essential in the maintenance of integrity in architecture and function of the nervous system, lack of which results in neural degeneration in a sensory nerve-dominant manner.

Laparoscope-assisted distal gastrectomy for early gastric cancer in a 76-year-old man with situs inversus totalis.

We report a case of a 76-year-old man with situs inversus totalis (SIT) who developed early gastric cancer. He was successfully treated by laparoscope-assisted distal gastrectomy for the gastric cancer. This case suggests that patients with SIT with malignancy could also undergo laparoscopic surgery. To the best of our knowledge, no case of laparoscopic surgery for malignant neoplasms associated with SIT has been reported in the English literature. We therefore believe this is the first case report.

Differential effects of protein kinase C on human vascular smooth muscle cell proliferation and migration.

Vascular smooth muscle cell (SMC) migration and proliferation contribute to intimal hyperplasia, and protein kinase C (PKC) may be required for both events. In this report, we investigated the role of PKC in proliferation and migration of SMC derived from the human saphenous vein. Activation of PKC by phorbol-12,13-dibutyrate (PDBu) or (-)-indolactam [(-)-ILV] increases SMC proliferation. Downregulation of PKC activity by prolonged incubation with phorbol ester or inhibition of PKC with chelerythrine in SMC diminished agonist-stimulated proliferation. In contrast, stimulation of PKC with PDBu or (-)-ILV inhibited basal and agonist-induced SMC chemotaxis. Moreover, downregulation of PKC or inhibition with chelerythrine accentuated migration. We postulated that the inhibitory effect of PKC on SMC chemotaxis was mediated through cAMP-dependent protein kinase (protein kinase A, PKA). In support of this hypothesis, we found that activation of PKC in SMC stimulated PKA activity. The cAMP agonist forskolin significantly inhibited SMC chemotaxis. Furthermore, the inhibitory effect of PKC on SMC chemotaxis was completely reversed by cAMP or PKA inhibitors. In search of the PKC isotype(s) underlying these differential effects of PKC in SMC, we identified eight isotypes expressed in human SMC. Only PKC-alpha, -beta I, -delta, and -epsilon were eliminated by downregulation, suggesting that one or more of these four enzymes facilitate the observed phorbol ester-dependent effects of PKC in SMC. In summary, we found that PKC activation enhances proliferation but inhibits migration of human vascular SMC. These differential effect of PKC on vascular cells appears to be mediated through PKC-alpha, -beta I, -delta, and/or -epsilon.

Intrahepatic pseudoaneurysm after surgical hemostasis for a delayed hemorrhage due to blunt liver injury: report of a case.

We report herein a case of delayed hemorrhage occurring after blunt hepatic trauma which was further complicated by an intrahepatic pseudoaneurysm. The delayed hemorrhage with free rupture occurred 2 weeks after the injury and the pseudoaneurysm developed 8 weeks after surgical hemostatic intervention for the delayed hemorrhage. The pseudoaneurysm was successfully treated by transcatheter arterial embolization. This rare case is reported to demonstrate the possibility of delayed catastrophic complications occurring after blunt liver injury and to point out the necessity of continued surveillance until the liver has completely healed.

Critical limb ischemia in a patient with von Recklinghausen's neurofibromatosis. Report of a case.

A 42-year-old woman complicated with neurofibromatosis underwent both balloon percutaneous transluminal angioplasty (PTA) of the iliac artery and femoropopliteal (FP) bypass grafting for critical lower limb ischemia. Seven months after the initial intervention, a recurrence of stenosis in the iliac artery and at the anastomoses of the FP bypass necessitated both PTA and a repeat thrombectomy and finally resulted in the amputation of her left thigh. This is a rarely documented case of chronic arterial occlusion associated with neurofibromatosis, in which the prognosis of arterial reconstruction for such patients is suggested to be poor.

Reoperation for graft failure of femoropopliteal bypass with externally supported knitted Dacron prosthesis.

BACKGROUND: Aggressive reoperation for failing or failed femoropopliteal (FP) bypass has been affirmative despite graft material. There has been no report regarding results of reoperation for FP bypass with externally supported knitted Dacron prosthesis (EXS). The aim of this study is to justify aggressive reoperation of FP bypass with EXS and to examine risk factors affecting the result of reoperation. METHODS: A retrospective review was performed on 204 patients undergoing 212 FP bypasses (with EXS between January 1982 and December 1997 and 34 FP EXSes of 32 patients underwent reoperation for graft failure until March 1998. The cumulative graft patency (GP) and limb salvage (LS) rate after first reoperation for 34 FP bypass EXS were calculated and the importance of each perioperative factor on GP or LS was estimated by uni- and multivariate analysis. RESULTS: Reoperated 34 FP EXSes included 12 failing and 22 failed grafts and 14 limbs with failed grafts underwent reoperation for limb salvage. The GP of 34 grafts and LS of 14 limbs rate were 58 and 67% at 2 years, respectively. Univariate analysis identified graft thrombosis (2 years GP; failing graft: failed graft=78: 48%) and continuance of smoking (2 years LS; smoker: non-smoker=43: 100%) as a significant risk factor of GP and IS, respectively, neither of which was significant by multivariate analysis. CONCLUSIONS: Early diagnosis and treatment, before graft thrombosis, can lead to superior durability of GP and discontinuance of smoking is important for LS.

Penetration by a huge abdominal aortic aneurysm into the lumbar vertebrae: report of a case.

We report herein the case of a 64-year-old man who underwent urgent surgery for a huge abdominal aortic aneurysm (AAA) with severe lumbago. At surgery, a defect in the posterior wall of the AAA, through which the adjacent lumbar vertebrae was seen after removal of intraluminal thrombi, was encountered with no evidence of blood leakage. This is a rare case of AAA that eroded the posterior wall and exposed the vertebrae.

Para-anastomotic aneurysms: incidence, risk factors, treatment and prognosis.

BACKGROUND: The purpose of this retrospective study was to analyze the incidence, risk factors, treatment, and prognosis of para-anastomotic aneurysms. METHODS: During the period between January, 1980 and August, 1996, 511 patients underwent surgical operations for arterial diseases with grafts and were followed for more than 30 days (average: 3.5 years). The number of anastomoses was 1445 in all. Until October, 1996, 18 para-anastomotic aneurysms had been detected in 13 patients. By Kaplan-Meier's method, the incidence of para-anastomotic aneurysms at 5, 10, and 15 years was 0.8, 6.2, and 35.8%, respectively. Univariate analysis indicated that arteriosclerosis obliterans, hypertension, thromboendarterectomy and an anastomosis in the groin were significant risk factors, while stepwised multivariate analysis revealed only hypertension as significant. The mean interval from the primary operation to the diagnosis was 79 months. Ten aneurysms were operated and seven were produced by dehiscence of the anastomotic line, namety anastomotic aneurysms, and three were juxta-anastomotic aneurysms with intact anastomotic lines. Eight patients underwent resection or exclusion of the aneurysm and reconstruction with a new graft and two patients underwent a replacement of the aneurysmal autovein patch to a Dacron one and aneurysmorrhaphy of the parent aneurysmal artery. RESULTS: No recurrence has been detected. In eight patients who were followed conservatively, two died of rupture and renal failure following acute arterial occlusion. CONCLUSIONS: Since para-anastomotic aneurysms can lead to fatal complications, an enlarging or symptomatic aneurysm should be treated promptly.

Infected abdominal aortic aneurysm caused by Campylobacter fetus subspecies fetus: report of a case.

A 45-year old man with fever, abdominal pain, and a pulsating mass underwent an aneurysmectomy, with in situ reconstruction using a bifurcated knitted Dacron graft, for a saccular abdominal aortic aneurysm (AAA). A culture taken postoperatively grew Campylobacter fetus subspecies fetus. The administration of antibiotics sensitive to this organism was continued for 3 months, and no infection has been encountered in the 1 year since his operation. This is only the 13th documented case of AAA infected by C. fetus subspecies fetus.

Fifteen-year experience in axillofemoral bypass with externally supported knitted Dacron prosthesis in a Japanese hospital.

BACKGROUND: Recently, several reports in the United States have demonstrated remarkable improvement in the patency of axillofemoral (AXF) bypass with an externally supported prosthesis. The purpose of this study was to review the prognoses regarding graft patency, limb salvage, and survival of patients who underwent AXF bypass grafting with an externally supported, knitted Dacron prosthesis (EXS) in a Japanese hospital and to analyze what factors affected the graft patency. METHODS: The clinical records of 81 patients with arteriosclerosis obliterans (ASO) who underwent 47 axillounifemoral bypasses and 34 axillobifemoral bypasses with EXS were retrospectively checked and, by uni- and multivariate analysis, perioperative factors were evaluated. RESULTS: The cumulative primary and secondary patency rates of AXF bypass grafts were 81% and 88%, 73% and 80%, and 70% and 77% at 3, 5, and 7 years, respectively, with no change thereafter. Limb salvage rate was 100%. The operative mortality was 3.7% and the survival rate was 63%, 41%, and 35% at 3, 5, and 7 years, respectively. The risk factors adversely affecting the patency were age (younger than 75 years), poor distal runoff, and preoperative leukocyte count (more than 8,000/microL) by univariate analysis, none of which were significant by stepwise multivariate analysis. CONCLUSIONS: AXF bypass using EXS was an acceptable procedure in ASO patients at high risk for conventional anatomic bypass or with limited life expectancy, and there was no significant risk factor that independently affected the patency.

LDL apheresis for arteriosclerosis obliterans with occluded bypass graft: change in prostacyclin and effect on ischemic symptoms.

To study the mechanism of efficacy of low-density lipoprotein (LDL) adsorption for arteriosclerosis obliterans (ASO), eight ASO patients without indication for bypass surgery underwent LDL apheresis twice a week for 5 weeks and the change in prostaglandin 12 (PGI2) and thromboxane A2 (TXA2) due to LDL apheresis was measured. The concentration of 6-keto-PGF1alpha, a metabolite of PGI2, in systemic venous blood significantly increased from 10.4 +/- 1.8 to 42.0 +/- 10.6 pg/mL (P<0.05) after one session of LDL apheresis, while no significant change of TXB2, a metabolite of TXA2, was encountered. The ratio of 6-keto-PGF1alpha/TXB2 also rose dramatically from 0.213 +/- 0.044 to 0.522 +/- 0.128 (P<0.05). In five patients, the ischemic clinical symptoms improved and both the concentration of 6-keto-PGF1alpha and the ratio of 6-keto-PGF1alpha/TXB2 increased significantly, whereas in three patients there was no effect on clinical symptoms and neither parameter changed. These results suggest that elevated production of PGI2 from vascular cells due to LDL apheresis might contribute to improvement of ischemic symptoms.

Intermittent claudication associated with persistent sciatic artery: report of two cases.

Two elderly women complaining of intermittent claudication complicated with persistent sciatic artery are herein reported. A direct femoral arteriogram showed hypoplasty of the superficial femoral artery and an unnatural anatomical relationship between the distal superficial femoral artery and the proximal popliteal artery, thus suggesting the presence of persistent sciatic artery. The diagnosis of persistent sciatic artery was finally made based on the aortography findings including the iliac arterial system and computed tomography (CT) scan. Magnetic resonance imaging (MRI) was helpful to demonstrate the entire image of this anomaly in cases with non-thrombolized sciatic artery. These diagnostic methods were useful in designing the optimal surgical strategy. The first case with a gluteal pulsating mass underwent exclusion of the persistent sciatic artery including the aneurysm through a retroperitoneal approach with a combination of femorotibial bypass, while the second case with thrombosed persistent sciatic artery only underwent femoropopliteal bypass. To recognize such a rare lesion, awareness of the differential diagnosis is important, and to provide appropriate treatment, an accurate whole image including adequate angiography, a CT scan, and magnetic resonance imaging is necessary.

Mitogen-activated protein kinase and proliferation of human vascular smooth muscle cells.

The intracellular messenger mitogen-activated protein kinase (MAPK) is activated in vascular smooth muscle cells (SMC) by various growth factors as well as by agonists that have no proliferative effect. We explored the hypotheses that SMC proliferation is associated with a specific pattern of MAPK activation by evaluating the kinetics of MAPK activation and tyrosine phosphorylation and the intracellular location of MAPK in SMC following addition of agonists of varying mitogenic potential. A peak in MAPK activation and tyrosine phosphorylation occurred 3-10 min after the addition of agonists to SMC derived from human saphenous vein (early phase), followed by a plateau of activity, which was variable in duration (late phase). A correlation was not found between mitogenicity and the degree to which MAPK became activated or tyrosine phosphorylated in the early phase. However, the duration of MAPK activation and tyrosine phosphorylation correlated strongly with the ability of agonists to stimulate SMC proliferation. Nuclear translocation of MAPK was associated with SMC proliferation, although the degree to which each agonist induced nuclear translocation did not parallel its mitogenic potential. The relative dependency of all three events on protein kinase C differed for each agonist and was greater in the late versus the early phase. Thus, in human SMC, nuclear translocation of MAPK and prolonged activation and tyrosine phosphorylation of MAPK are associated with growth factor-induced mitogenesis.

Requirement for protein kinase C activation in basic fibroblast growth factor-induced human endothelial cell proliferation.

The intracellular signaling mechanisms that mediate basic fibroblast growth factor (bFGF)-induced angiogenesis have not been fully identified. In particular, whether activation of the intracellular enzyme protein kinase C (PKC) is necessary or sufficient for bFGF-induced mitogenesis of human endothelial cells is not clear. Accordingly, the effect of bFGF stimulation on the Ca2+ increase and PKC activity of normal human endothelial cells (HEC) was studied, as was the effect of inhibition of PKC and the distribution of PKC isoenzymes in these cells. The addition of bFGF to cultured HEC increased overall PKC activity in the absence of an increase in intracellular Ca2+ and markedly stimulated their proliferation, as did the addition of PKC-activating phorbol esters. bFGF-induced proliferation was prevented by the PKC inhibitors chelerythrine and H-7 and by downregulation of PKC after prolonged incubation with phorbol esters. In contrast, these inhibitors did not prevent HEC proliferation induced by epidermal growth factor. Because of the failure of bFGF to increase Ca2+, we determined whether bFGF-induced proliferation could be mediated by novel or atypical PKC isoenzymes (which are not regulated by Ca2+). Investigation of the isoenzyme distribution of confluent and subconfluent HEC by immunoblotting, Northern transfer analysis, and polymerase chain reaction of reverse-transcribed RNA revealed the presence of several novel and atypical isoenzymes (PKC-delta, -eta, -theta, and -zeta) as well as small amounts of the conventional (Ca(2+)-regulated) isoenzymes PKC-alpha and -beta. Activation of PKC by bFGF, in the absence of an increase in intracellular Ca2+, suggests that one or more of these Ca(2+)-independent PKC isoenzymes are both necessary and sufficient for HEC proliferation after bFGF.

Preliminary evaluation of a technique for inhibiting intimal hyperplasia: implantation of a resorbable luminal collagen membrane.

Pharmacologic control of intimal hyperplasia has been attempted through oral and intravenous administration of smooth muscle cell inhibitors. We report a more direct method of altering arterial healing using a novel bioresorbable membrane that can be applied to the lumen of an artery or anastomosis following endarterectomy or vascular reconstruction. Following a standard balloon injury, the infrarenal aortas of 3 kg female New Zealand white rabbits were opened and a thin membrane composed of collagen/chondroitin 6-sulfate copolymer was sutured to the posterior wall of each artery. Animals were killed at intervals of up to 3 months. All arteries remained patent. By 24 hours the membrane had become infiltrated with fibrin and red blood cells. An inflammatory response ensued and by 8 days the membrane was filled with mononuclear cells. At 3 months only a small remnant of the membrane remained. Intimal hyperplasia developed throughout the injured aorta. However, the hyperplastic response beneath the membrane was no greater than that observed in the adjacent injured aorta. A bioresorbable membrane can be sutured into the lumen of a small-diameter vessel without inducing thrombosis and without locally increasing intimal hyperplasia. A prosthesis of this type might be used to deliver inhibitors of smooth muscle cell proliferation and migration to the injured arterial wall.