Younger onset myeloperoxidase-specific antineutrophil cytoplasmic antibody- (MPO-ANCA) related glomerulonephritis accompanied with nephrotic syndrome

It is known that nephrotic syndrome rarely accompanies myeloperoxidase-specific antineutrophil cytoplasmic antibody- (MPO-ANCA) related glomerulonephritis. We present a case of younger onset MPO-ANCA-related glomerulonephritis accompanied with nephrotic syndrome in a female patient. It was diagnosed through the renal biopsy and the detection of a high titer of MPO-ANCA and steroid therapy (intravenous steroid pulse therapy and oral administration), anticoagulant therapy and antiplatelet therapy were initiated. Since her nephrotic syndrome persisted in spite of the decrease of MPO-ANCA, we conducted a second renal biopsy. We found active necrotizing crescentic glomerulonephritis with a small deposition of immunoglobulin and fibrinogen on the glomeruli. To suppress her disease activity, we administered second steroid-pulse therapy and MPO-ANCA titer disappeared. However, as her nephrotic syndrome, which was accompanied by severe hyperlipidemia, persisted, we tried to treat her using low-density lipoprotein (LDL) apheresis. It was effective temporarily, but she finally fell into end-stage renal failure. We discuss here the possibility of double nephropathy by considering her clinical and renal pathologic features.

Ex vivo gene transfer of basic fibroblast growth factor improves cardiac function and blood flow in a swine chronic myocardial ischemia model

We previously reported adenovirus-mediated ex vivo gene transfer of basic fibroblast growth factor (bFGF) as a new treatment for leg ischemia. This time, we tested this method on a swine myocardial ischemia model, seeking the possibility of its application for ischemic heart disease. An ameroid constrictor was placed around the proximal left circumflex branch of pigs to induce myocardial ischemia. Simultaneously, a skin section was harvested and fibroblasts were cultured. Fibroblasts were then infected with adenovirus vector containing a bFGF cDNA with a secretory signal sequence (bFGF group, n=8) or a LacZ cDNA (control group, n=8). At 28 days after constrictor implantation, 2.5 x 10(6) fibroblasts were administered into each of the right and left coronary arteries. The injected fibroblasts accumulated in the myocardium without causing myocardial ischemia. Echocardiography, electromechanical mapping and coronary arteriography were conducted just before and 28 days after fibroblast injection, and regional left ventricular myocardial blood flow was measured 28 days after fibroblast injection. These evaluations revealed that the bFGF group exhibited significant development of collateral vessels and improvement of myocardial contraction in the ischemic area compared with the control group. We believe that this method is a promising treatment strategy for ischemic heart disease.

A case of an ABO-incompatible renal transplant with abundant intratubular basement membrane immune deposits

We present a case of a 30-year-old man who received an ABO-incompatible renal transplant from his mother in 1996 after haemodialysis for 3 years. Although his renal function was stable, a renal biopsy was performed while he was in hospital for treatment of herpes zoster in 1999. Light microscopy provided no evidence of obvious acute or chronic rejection but a double contour pattern was observed in many tubular basement membranes (TBM). Immunofluorescence microscopy revealed deposits of IgG and C3 on the TBM in the absence of glomerular deposition. Massive electron-dense deposits were observed clearly by electron microscopy within TBM, revealing splitting and lamellation. This implies that the deposits resulted from the formation of immune complexes, but not from anti-TBM antibody. Although the role of TBM deposits in tubular injury is controversial, careful observation of patients with such deposits may be required because of their potential ability to induce immune reactions.

Fibrinogens Kosai and Ogasa: Bbeta15Gly-->Cys (GGT-->TGT) substitution associated with impairment of fibrinopeptide B release and lateral aggregation

We found two heterozygous dysfibrinogenemias, designated fibrinogen Kosai and fibrinogen Ogasa. Kosai was associated with arteriosclerosis obliterans but Ogasa showed no bleeding or thrombotic tendencies. The plasma fibrinogen concentrations from the two propositi (Ogasa and Kosai) were much lower when determined by the thrombin-time method (0.94 and 1.06 g L(-1), respectively) than when determined by the immunological method (2.87 and 2.72 g L(-1), respectively). We performed DNA sequencing and functional analyses to clarify the relationship between the structural and functional abnormalities. Genetic analysis of PCR-amplified DNA from the propositi identified the heterozygous substitution Bbeta15Gly-->Cys (GGT-->TGT). Western blotting analysis of purified fibrinogen revealed the existence of albumin-fibrinogen complexes. Functional analyses indicated that compared with the normal control, the propositi's fibrinogen released only half the normal amount of fibrinopeptide B and showed markedly impaired polymerization. In addition, the observation of thinner fibers in fibrin clots (by scanning electron microscopy) indicated markedly defective lateral aggregation in the variant fibrinogens. The impaired functions may be due to the substitution of Cys for Bbetao15Gly plus the existence of some additional disulfide-bonded forms.

Infrainguinal arterial reconstruction for limb salvage in patients with end-stage renal disease

OBJECTIVES

to evaluate the efficacy of infrainguinal bypass for limb-threatening ischaemia in patients with end-stage renal disease (ESRD).

MATERIALS AND METHODS

from 1991 through 2000, 28 limbs in 22 patients with ESRD received 33 infrainguinal bypasses, while 65 limbs in 57 patients with functioning kidneys underwent 77 bypasses for limb salvage. The prevalence of diabetes is higher in the ESRD group (p = 0.03).

RESULTS

perioperative mortality and patient survival rate in the follow-up period were significantly poorer in patients with ESRD (18% vs 0%; p = 0.001, and 45% vs 85%, p < 0.001, respectively). Most causes of death were related to atherosclerosis or respiratory diseases. In spite of no significant difference in 2-year primary and secondary graft patency rates and limb salvage between the ESRD and non-ESRD groups (76% vs 83%; p = 0.12, 85% vs 91%; p = 0.06, and 83% vs 93%; p = 0.06, respectively), two cases of early limb loss occurred as a result of uncontrolled infection in the ESRD group. In contrast to autogenous conduits, nonautogenous conduits revealed a poorer outcome in ESRD patients (p = 0.03).

CONCLUSIONS

perioperative mortality and patient survival rate were significantly poorer in the ESRD group. Preoperative full evaluation of myocardial and brain ischaemia, revascularisation with autogenous conduits, appropriate treatment of wound infection, and strict follow-up for accompanying diseases may be needed in these patients.

Effective antibiotic treatment of methicillin-resistant Staphylococcus aureus-associated glomerulonephritis

BACKGROUND

A new type of glomerulonephritis following a methicillin-resistant Staphylococcus aureus (MRSA) infection has been reported. The purpose of this study is to elucidate the clinicopathological features and the responsiveness to treatment of the disease.

METHODS

We studied the treatment of 8 patients with glomerulonephritis related to MRSA infection. We observed the eight cases and analyzed clinical features, laboratory findings and histopathological data.

RESULTS

On admission, all patients had no renal abnormalities. One to four months after suffering from MRSA infection, severe proteinuria and hematuria developed. Renal biopsy specimens revealed moderate to severe mesangial proliferative glomerulonephritis with various degrees of crescent formation. Immunofluorescence studies showed IgA and C3. Antibiotic therapy was performed in six cases, resulting in successfully reducing the proteinuria in parallel with the decreased activity of MRSA infection in five cases. The other 2 cases received corticosteroid treatment after complete cessation of MRSA infection, but they had a relapse of MRSA infection and later died from sepsis.

CONCLUSIONS

These results suggested that MRSA-associated glomerulonephritis might respond to antibiotic treatment in most cases. This also indicated that special care must be taken in the application of steroid therapy for the glomerulonephritis with crescents, even though the MRSA infection has gone into an inactive state.

MPO-ANCA-positive slowly progressive glomerulonephritis with focal tuft necrosis and crescents

A 37-year-old woman had been found to have proteinuria in October 1996. About 8 months later, the first renal biopsy was performed, revealing focal segmental necrotizing and crescentic glomerulonephritis. At that time, serum creatinine was 1.0 mg/dl and urinary protein 3+. In October 1999, laboratory tests revealed positivity for MPO-ANCA and a serum creatinine level of 1.42 mg/dl, anemia and proteinuria of 2+. A second renal biopsy showed almost the same histological findings. Accordingly, a diagnosis of MPO-ANCA positive glomerulonephritis was made. This patient was thought to be a rare case of MPO-ANCA-positive slowly progressive glomerulonephritis presenting focal segmental tuft necrosis and crescents.

A case of mixed membranous nephropathy and purpura nephritis

We report the case of a 71-year-old man with mixed glomerular lesions, membranous and necrotizing changes. The patient had abdominal pain and purpurat on the extremities and trunk, followed by melena, and after admission to hospital, proteinuria and occult blood were noted. Laboratory findings were negative for autoimmune disease and viral hepatitis. Renal biopsy showed segmental necrotizing changes and mesangial proliferation with spike formation. Immunofluorescence revealed a granular deposition of IgA predominantly in the mesangial area in contrast to the granular IgG deposition along the glomerular capillary loops. Moreover, electron-microscopically, mesangial as well as subepithelial electron-dense deposits were observed. These data suggest that the patient had 2 distinct types of glomerulonephritis simultaneously: idiopathic membranous nephropathy and purpura nephritis.

Quantitative RT-PCR analysis demonstrates that synthesis of the recombinant fibrinogen is dependent on the transcription and synthesis of gamma-chain

BACKGROUND

The purpose of this study was to examine the relationship between the production of secreted fibrinogen and the synthesis of gamma-chain mRNA.

METHODS

We transfected a gamma-chain expression vector into Chinese hamster ovary cells already expressing both Aalpha- and Bbeta-chains of fibrinogen and measured fibrinogen output concentrations by ELISA. We quantified both gamma-chain and Bbeta-chain mRNA concentrations using the recently developed TaqMan fluorogenic detection system.

RESULTS

The concentration of secreted fibrinogen into the media positively correlated with the amount of fibrinogen contained in the cell lysates. Additionally, quantitative mRNA assays revealed that the fibrinogen concentration in the cell lysates correlated well with the concentration of gamma-chain mRNA (r=0.7077, p<0.01) but not with the concentration of Bbeta-chain mRNA (r=0.0224, NS).

CONCLUSIONS

These results demonstrate that the amount of recombinant fibrinogen produced in cells transfected with the gamma-chain vector, also expressing normal Aalpha- and Bbeta-chains, is dependent on the transcription of gamma-chain mRNA. Namely, in this recombinant expression system using a two-step transfection procedure, gamma-chain synthesis is the rate-limiting factor for fibrinogen production. This quantitative method to measure mRNA may prove very useful for further in vivo analysis of fibrinogen gene transcription.

Oxygen saturation measurement of calf muscle during exercise in intermittent claudication

OBJECTIVES

to evaluate the oxygen saturation of the calf muscle measured by means of spatially resolved spectroscopy (SRS) in claudicants.

METHODS

a total of 150 legs in 84 consecutive patients with calf claudication were studied by SRS. Oxygen saturation (SmO(2)) and the relative changes in oxygenated haemoglobin (HbO(2)) and deoxygenated haemoglobin (Hb) of the gastrocnemius muscle were measured during a treadmill walking test (2.4 km/h, 12%, 5 min).

RESULTS

exercise was associated with a decrease in HbO(2) and an increase in Hb. There was no difference in SmO(2) at rest among all groups. The decrease oxygen saturation correlated well with the severity of symptoms of IC.

CONCLUSION

muscle oxygen saturation measurement by SRS can be used clinically to provide objective information regarding the severity of IC.

Enzymatically deglycosylated human IgA1 molecules accumulate and induce inflammatory cell reaction in rat glomeruli

BACKGROUND

Previously, we have been able to isolate IgA1 from IgA nephropathy (IgAN) patients, that could accumulate in rat glomeruli (glomerulophilic IgA1). The 'glomerulophilic IgA1' was determined to be under-O-glycosylated in its hinge region, suggesting that under-O-glycosylation in the IgA1 hinge region plays a role in its glomerular deposition in IgAN. To confirm this, the accumulation of enzymatically under-glycosylated IgA1 in rat kidney was examined.

METHODS

Human IgA1 was isolated from healthy individuals by Jacalin-affinity chromatography. Desialylated (deS IgA1) or further degalactosylated IgA1 (deS/deGal IgA1) molecules were then prepared using neuraminidase and beta-galactosidase. Two or five mg of IgA1 were injected into the left renal artery of Wistar rats. The rats were sacrificed at various time intervals (3, 9, 24 h) and the perfused part of the renal cortex was removed for immunofluorescence and for light and electron microscopy.

RESULTS

Distinct amounts of deS IgA1 and deS/deGal IgA1 were observed in rat glomeruli. On the other hand, untreated IgA1 molecules (native IgA1) did not show any obvious accumulation. In rats injected with under-glycosylated IgA1, accumulation of polymorphonuclear cells (PMN) was also observed.

CONCLUSIONS

These results confirmed that under-glycosylation of IgA1 played an important role in the glomerular accumulation of IgA1, which was followed by infiltration of PMN into glomeruli.

Comparison of two spatially resolved near-infrared photometers in the detection of tissue oxygen saturation: poor reliability at very low oxygen saturation

Two spatially resolved oximeters, NIRO-300 and OM-200, were compared with regard to the measurement of oxygen saturation values in two forearm muscle groups at rest and during arterial occlusion in nine healthy volunteers. There was a significant correlation between the muscle oxygen saturation values obtained at rest using the two oximeters (n=33, r(2)=0.43, P<0.0001), whereas these values were significantly different during arterial occlusion. Thus, although there was good agreement between muscle oxygen saturation values measured using the two oximeters, the operating range of the tissue oximeters should be recognized and indicated.

Coronary revascularization in Japan. Part 1: survey of facilities during 1997

Coronary artery disease is one of the major causes of morbidity and mortality in industrialized countries, including Japan. Increasing numbers of patients have been treated with percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), but there is little information in Japan concerning the use of revascularization therapy and the facilities. The Japanese Coronary Intervention Study (JCIS) Group conducted a nationwide survey on coronary revascularization procedures and facilities during 1997. A questionnaire was mailed to the presidents or designated delegates of 8,253 laboratories in 7,986 hospitals that had departments of internal medicine and/or cardiovascular medicine and to 578 facilities in 558 hospitals identified by the PCI survey as performing CABG and/or registered in the annual survey carried out by the Japanese Association for Thoracic Surgery. A total of 109,788 PCIs were performed at 1,023 laboratories, and 17,667 CABGs at 477 facilities. PCI and CABG numbers per 10(6) population were 870 and 140, respectively. The ratio of PCI to CABG was 6.2. The numbers of PCI laboratories and CABG facilities per 10(6) population were 8.1 and 3.8, respectively. The majority of PCI laboratories and CABG facilities had a small annual volume: 44% of PCI laboratories and 77% of CABG facilities had annual volumes of 50 or less. Only half of the PCI laboratories had surgical backup on-site. Despite the small volume for each facility, coronary revascularization, especially PCI, is highly utilized in Japan.

Coronary revascularization in Japan. Part 2: comparison of facilities between 1997 and 1999

A nation-wide survey on the procedures and facilities of coronary revascularization, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) conducted by the Japanese Coronary Intervention Study (JCIS) group during 1997 revealed that PCI is more often used than CABG and is mainly carried out in low-volume facilities without surgical backup. The present study aimed to investigate the temporal changes in the usage of revascularization therapies and facilities from 1997 to 1999. A questionnaire was mailed in 1998 to the delegates of 1,086 PCI and 582 CABG facilities identified by the previous survey, and 89% of PCIs surveyed and 94% of CABGs surveyed reported back. The number of PCI procedures had increased by 19% from 97,831 to 116,479 and that of CABG procedures also increased by 21% from 16,374 to 19,846. The ratio of PCI to CABG was 5.9 in 1999, showing no significant change from 6.0 in 1997. In parallel, the number of PCI and CABG facilities increased from 888 to 941 and from 442 to 453, respectively. The use of coronary stents and other interventional devices increased during these 2 years. Coronary stents were used regardless of the annual procedural volume of the facilities, whereas other interventional devices, directional and rotational coronary atherectomy, were used mainly in the high-volume laboratories (p<0.01). Beating-heart, off-pump CABG had increased from 2% to 11% of total cases. Continued monitoring of trends in PCI and CABG facilities and procedures will be needed for nation-wide assessment of the use of new technology.

Glomerular expression of alpha-smooth muscle actin reflects disease activity of IgA nephropathy

To elucidate the relationship between histological disease states and clinicopathological features in immunoglobulin A nephropathy (IgAN), 90 needle-biopsy specimens diagnosed as IgAN were analyzed. The specimens were divided into four groups according to histological grade and stage index. Immunohistochemical features of alpha-smooth muscle actin (alpha-SMA), macrophages positive for myeloid/histiocyte antigen (MAC387), and expression of type I, III and IV collagens were all examined. Glomerular expression scores of alpha-SMA and the degree of intraglomerular macrophage infiltration were highest in the active and non-sclerotic groups. Type I and IV collagens were significantly more abundant in the sclerotic groups than in the active groups. Type III collagen was strongly expressed in both the active and sclerotic groups. Double immunolabeling of alpha-SMA and intercellular adhesion molecule (ICAM)-1 revealed that ICAM-1 was expressed around the alpha-SMA-positive mesangial area. In multivariate analysis, the glomerular expression score of alpha-SMA was mostly correlated with histological grading in the 10 clinicopathological parameters. Type IV collagen score was mostly correlated with histological staging. These results suggest that glomerular alpha-SMA expression reflects the histological activity of IgAN. Immunohistological staining of alpha-SMA is valuable to estimate the degree of disease activity in IgAN.

Delayed recurrence of teratoid cyst 17 years after enucleation

This report describes a teratoid cyst showing delayed recurrence 17 years after enucleation. A brief discussion concerning disease recurrence is also provided.

Structural fragility of blood vessels and peritoneum in calponin h1-deficient mice, resulting in an increase in hematogenous metastasis and peritoneal dissemination of malignant tumor cells

We have observed weak expression of calponin h1, which stabilizes the actin filament system, in blood vessels within human malignant tumors. This observation suggested that because of a deficiency in stabilization by calponin h1, the structure of blood vessels in malignant tumors is fragile compared with blood vessels in normal tissues. We therefore generated calponin h1-deficient (CN(-/-)) mice to examine the effect of calponin h1 on the integrity of the barrier system in blood vessels against cancer metastasis. The CN(-/-) mice exhibited morphological fragility of the tissues, including the uterus and blood vessels. In particular, we frequently observed bleeding into the surrounding tissue from blood vessels of the ocular fundus in CN(-/-) mice. In addition, mesothelial cells, which usually express calponin h1 in normal (CN(+/+)) mice, were retracted in the CN(-/-) mice. When fluorescein was injected i.v. into mice, the CN(-/-) mice exhibited a greater and more rapid leakage of fluorescein from the blood vessels of the ocular fundus compared with the CN(+/+) mice. In the CN(-/-) mice receiving i.v. inoculations of B16 melanoma cells, significantly more metastatic nodules were formed in the lung than in the CN(+/+) mice. When B16 melanoma cells were injected i.p., the severity of peritonitis carcinomatosa was greater in CN(-/-) than in CN(+/+) mice. These results indicate that calponin h1 plays an important role in the regulation of the integrity of the blood vessels and peritoneum, which in turn is an important factor influencing the frequency of cancer metastasis. The CN(-/-) mice, which exhibit fragile blood vessels and peritoneum, could serve as sensitive and useful host models to investigate cancer metastasis.

Extracranial carotid aneurysm in Takayasu's arteritis

Extracranial carotid aneurysm caused by Takayasu's arteritis is extremely rare. We have experienced six cases of extracranial carotid aneurysm among 106 cases of Takayasu's arteritis that were treated surgically in the past 50 years. We herein review these cases and discuss the surgical indications and postoperative course of this rare disease. We report original observations about extracranial carotid aneurysm in Takayasu's arteritis.

Overexpression of eNOS in the RVLM causes hypotension and bradycardia via GABA release

In this study, we examine the role of NO located in the rostral ventrolateral medulla (RVLM) in the control of blood pressure and the activity of the sympathetic nervous system. To determine the effect of an increase in NO production in the RVLM on blood pressure in conscious rats, adenovirus vectors encoding either endothelial NO synthase (AdeNOS) or beta-galactosidase (Adbetagal) were transfected into the bilateral RVLM. The local expression of endothelial NO synthase (eNOS) protein in the RVLM was confirmed by immunohistochemical staining for the eNOS protein and by Western blot analysis. Mean arterial blood pressure (MAP) and heart rate, which were monitored using a radio-telemetry system, were significantly decreased in the AdeNOS-treated group from day 5 to day 10 after the gene transfer. Urinary norepinephrine excretion was decreased on day 7 after the gene transfer in the AdeNOS-treated group. Microinjection of either N(G)-monomethyl-L-arginine (L-NMMA) or bicuculine, a gamma-amino butyric acid (GABA) receptor antagonist, into the RVLM at day 7 after the gene transfer increased MAP to significantly greater levels in the AdeNOS-treated group. However, microinjection of kynurenic acid into the RVLM on day 7 after the gene transfer did not alter MAP levels in either group. GABA and glutamate levels in the RVLM, when measured by in vivo microdialysis, were significantly increased in the AdeNOS-treated group. These results suggest that the increase in NO production caused by the overexpression of eNOS in the bilateral RVLM decreases blood pressure, heart rate, and sympathetic nerve activity in conscious rats. Furthermore, these responses may be mediated by an increased release of GABA in the RVLM.

Rare complication of saccular aneurysm and histological dissection: an autopsy study of 5865 elderly cases

The purpose of this study was to examine complicated lesions of saccular aneurysm and dissection. We investigated the ascending aortae in 5865 consecutive elderly autopsy cases, and 5 cases (0.085%) of aortic saccular aneurysms associated with dissection at the edges were selected. Their edges characteristically protruded like a shelf, which histologically consisted of an inner part of the dissected media. All patients were female and their mean age was 76.8 (67-89) years. The aneurysmal walls at the center showed severe fragmentation and disappearance of the elastic lamellae of the remaining outer media. Thus, partial sections of these lesions were not sufficient but cross-sections of the whole diseased regions including the edges were essential for diagnosis. One patient had 3 saccular aneurysms and an adjacent shallow depression, which we called "healed microscopic dissection". Histologically, it showed disappearance of the inner media and was replaced by fibrosis in continuation from the intima. This lesion showed no findings of intramural hemorrhage or thrombus, and thus it will differ from organized thrombi in the dissected false lumen. Another patient presented had an aneurysmal rupture which resulted in cardiac tamponade. This case implies the need for surgical treatment of this entity.

Transcatheter arterial chemoembolization therapy combined with percutaneous ethanol injection for unresectable large hepatocellular carcinoma: an evaluation of the local therapeutic effect and survival rate

BACKGROUND/AIMS

This study was undertaken to evaluate the effectiveness of combination therapy with transcatheter arterial chemoembolization followed by percutaneous ethanol injection in patients with unresectable large hepatocellular carcinoma by comparing the use of this combined regimen with transcatheter arterial chemoembolization alone.

METHODOLOGY

Six hundred and thirty-one consecutive patients with hepatocellular carcinoma lesions observed from Jan 1989 to Dec 1999 (11 years) at the Internal Medicine Department, Saga Prefectural Hospital Koseikan were retrospectively enrolled in the study. The series included 120 patients with large unresectable hepatocellular carcinoma lesions, the largest of which were greater than 3 cm in largest dimension. Fifty-two patients underwent a single transcatheter arterial chemoembolization followed by percutaneous ethanol injection, which were compared with 68 patients treated by transcatheter arterial chemoembolization alone. Both groups of patients with hepatocellular carcinoma did not differ regarding the base-line characteristics. The overall survival rates and recurrence ratio of initially treated lesions were compared in both groups.

RESULTS

On overall survival rates by the Kaplan-Meier method, three- and five-year survival in the transcatheter arterial chemoembolization and percutaneous ethanol injection group (59.0%, 32.1%) proved to be significantly longer than those in the transcatheter arterial chemoembolization group (27.1%, 17.0%). In addition, during the follow-up local recurrence in the combination group (23.1%) was significantly lower than that in the transcatheter arterial chemoembolization group (50.0%).

CONCLUSIONS

The combined treatment with transcatheter arterial chemoembolization and percutaneous ethanol injection proved to be more effective and safer. Furthermore, a lower incidence of local recurrence was observed than transcatheter arterial chemoembolization alone which resulted in an increased survival of the patients associated with unresectable large hepatocellular carcinoma lesions.

Non-anastomotic midgraft stenosis of a knitted Dacron graft after arterial reconstruction. Report of a case

Midgraft stenosis of the prosthesis after bypass surgery has seldom been reported. A man presented with an ischemic ulcer of the left foot. He had undergone bilateral femoropopliteal bypass surgery as well as left-sided iliofemoral bypass surgery with a knitted Dacron graft. The graft in his left thigh was occluded. A knitted Dacron conduit with 8-mm diameter was interposed between the iliofemoral bypass graft and the left profunda femoris artery, and graft-popliteal jumping bypass surgery was added. The postoperative angiogram showed a short-segmental severe stenosis of the interposed graft neighboring the proximal anastomosis. Repeat surgery showed that the stenotic lesion was located separately from the anastomosis. This midgraft stenosis was considered to consist of dissection of pseudointima associated with the intraoperative procedures. In cases of repeat surgery around the inguinal ligament, procedures should be performed with great care.

Noise-enhanced heart rate and sympathetic nerve responses to oscillatory lower body negative pressure in humans

By injecting noise into the carotid sinus baroreceptors, we previously showed that heart rate (HR) responses to weak oscillatory tilt were enhanced via a mechanism known as "stochastic resonance." It remains unclear, however, whether the same responses would be observed when using oscillatory lower body negative pressure (LBNP), which would unload the cardiopulmonary baroreceptors with physically negligible effects on the arterial system. Also, the vasomotor sympathetic activity directly controlling peripheral resistance against hypotensive stimuli was not observed. We therefore investigated the effects of weak (0 to approximately -10 mmHg) oscillatory (0.03 Hz) LBNP on HR and muscle sympathetic nerve activity (MSNA) while adding incremental noise to the carotid sinus baroreceptors via a pneumatic neck chamber. The signal-to-noise ratio of HR, cardiac interbeat interval, and total MSNA were all significantly improved by increasing noise intensity, while there was no significant change in the arterial blood pressure in synchronized with the oscillatory LBNP. We conclude that the stochastic resonance, affecting both HR and MSNA, results from the interaction of noise with the signal in the brain stem, where the neuronal inputs from the arterial and cardiopulmonary baroreceptors first come together in the nucleus tractus solitarius. Also, these results indicate that the noise could induce functional improvement in human blood pressure regulatory system in overcoming given hypotensive stimuli.