Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Morphological lymphocytic reaction, patient prognosis and PD-1 expression after surgical resection for oesophageal cancer

BACKGROUND

Immune checkpoint inhibitors, such as antibody against programmed cell death protein (PD-1), have demonstrated antitumour effects in patients with malignancies, including oesophageal cancer. A lymphocytic reaction observed by pathological examination is a manifestation of the host immune response to tumour cells. It was hypothesized that a stronger lymphocytic reaction to tumours might be associated with favourable prognosis in oesophageal cancer.

METHODS

Using a database of resected oesophageal cancers, four morphological components of lymphocytic reactions (peritumoral, intranest, lymphoid and stromal) to tumours were evaluated in relation to clinical outcome, PD-1 expression by immunohistochemistry and total lymphocyte count in blood.

RESULTS

Resected oesophageal cancer specimens from 436 patients were included in the study. Among the four morphological components, only peritumoral reaction was associated with patient prognosis (multivariable P for trend <0·001); patients with a higher peritumoral reaction had significantly longer overall survival than those with a lower reaction (multivariable hazard ratio 0·48, 95 per cent c.i. 0·34 to 0·67). The prognostic effect of peritumoral reaction was not significantly modified by other clinical variables (all P for interaction >0·050). Peritumoral reaction was associated with total lymphocyte count in the blood (P < 0·001), supporting the relationship between local immune response and systemic immune competence. In addition, higher morphological peritumoral reaction was associated with high PD-1 expression on lymphocytes in tumours (P = 0·034).

CONCLUSION

These findings should help to improve risk-adapted therapeutic strategies and help stratify patients in the future clinical setting of immunotherapy for oesophageal cancer.

Clinical utility of exhaled carbon monoxide in assessing preoperative smoking status and risks of postoperative morbidity after esophagectomy

Whereas smoking constitutes a significant risk factor for postesophagectomy morbidity, there is no reliable method to assess the smoking status of patients prior to the procedure. Since exhaled carbon monoxide (CO) is an indicator of recent smoking, this paper hypothesizes that this is a useful parameter in assessing current smoking status and may help predict morbidity following esophagectomy. Sixty-nine patients, who had undergone elective three-incision esophagectomy with two- or three-field lymphadenectomy for esophageal cancer, were prospectively studied between February 2015 and September 2017. At surgical admission, they were asked about their smoking history, their exhaled CO levels were evaluated, and they were grouped into three based on their CO levels. These were 0 parts per million (ppm), >0 and <7 ppm, and ≥7 ppm. Their postoperative morbidity was also assessed. Approximately 13.5% of the patients showed high levels of exhaled CO ≥ 7 ppm, despite preoperatively reporting smoking cessation for over a month. Morbidities of the Clavien-Dindo classification (CDc) ≥ II increased as exhaled CO levels increased and severe morbidity of CDc ≥ IIIb frequently was observed in patients with exhaled CO levels ≥7 ppm. The logistic regression analysis showed that exhaled CO level ≥7 ppm was an independent risk factor for severe postesophagectomy morbidity. Overall, the results of this study suggest that exhaled CO levels may be useful in estimating current smoking status and that it may also help give an estimation of the risk of postesophagectomy morbidity.

Minimally invasive esophagectomy may contribute to long-term respiratory function after esophagectomy for esophageal cancer

Evidence suggests that minimally invasive esophagectomy has several advantages with regard to short-term outcomes, compared to open esophagectomy in esophageal cancer patients. However, the impact of minimally invasive esophagectomy on long-term respiratory function remains unknown. The objective of this study is to assess the association between use of the minimally invasive esophagectomy and long-term respiratory dysfunction in esophageal cancer patients after esophagectomy. This retrospective single institution study using prospectively collected data included 87 consecutive esophageal cancer patients who had undergone esophagectomy. All patients underwent a respiratory function test before, and one year after esophagectomy. Logistic regression analysis was used to compute the hazard ratio for long-term respiratory dysfunction. Minimally invasive esophagectomies were performed in 53 patients, and open esophagectomies in 34 patients. The two groups showed no significant differences in terms of postoperative complications and postoperative course. Nor were any differences observed between the two groups in terms of volume capacity (L) and forced expiratory volume 1.0 (L) before esophagectomy (P > 0.34). However, one year after esophagectomy, the decreases in volume capacity and forced expiratory volume 1.0 were significantly less in the minimally invasive esophagectomy group than in the open esophagectomy group (P = 0.04 and P = 0.007, respectively). Multivariate analyses revealed that minimally invasive esophagectomy was an independent favorable factor for maintenance of forced expiratory volume 1.0 (hazard ratio = 0.17, 95% confidence interval 0.04-0.71; P = 0.01). Minimally invasive esophagectomy may be an independent favorable factor for maintenance of long-term respiratory function in esophageal cancer patients after esophagectomy.

Pyloroplasty may reduce weight loss 1 year after esophagectomy

Weight loss after esophagectomy is common and is associated with unfavorable prognosis. However, the clinical features and surgical methods that influence postesophagectomy weight loss are not well characterized. This study aims to determine those features (especially the surgical methods) that may affect postoperative weight loss. We reviewed 221 esophageal cancer patients who had undergone esophagectomy at Kumamoto University Hospital (Kumamoto, Japan) between November 2012 and June 2015. Among these, we recruited 106 patients who had undergone transthoracic esophagectomy with gastric conduit reconstruction, had no cancer recurrence within 1 year, and no missing follow-up data. We tabulated the body weight changes and risk factors associated with weight loss exceeding 10% at 1-year postesophagectomy. The mean body weights at baseline and 1-year postsurgery were 60.3 kg (standard error (SE): 0.91) and 52.6 (SE: 0.91), respectively. One year postsurgery, the body weights had changed as follows: mean: -12.2%; median: -12.9%; standard deviation: 9.06; range: -36.1-18.56%; interquartile range: -10.5 to -14.0%. In the multivariate logistic regression analysis, the absence of pyloroplasty was the sole risk factor for more than 10% weight loss (OR: 3.22; 95% CI: 1.08-11.9; P = 0.036). Our data suggest that pyloroplasty with esophagectomy can overcome the post-surgical weight loss.

Monitoring sputum culture in resected esophageal cancer patients with preoperative treatment

Pneumonia is a major cause of postesophagectomy mortality and worsens the long-term survival in resected esophageal cancer patients. Moreover, preoperative treatments such as chemotherapy or chemoradiotherapy (which have recently been applied worldwide) might affect the bacterial flora of the sputum. To investigate the association among preoperative treatments, the bacterial flora of sputum, and the clinical and pathological features in resected esophageal cancer patients, this study newly investigates the effect of preoperative treatments on the bacterial flora of sputum. We investigated the association among preoperative treatments, the bacterial flora of sputum, and clinical and pathological features in 163 resected esophageal cancer patients within a single institution. Pathogenic bacteria such as Candida (14.1%), Staphylococcus aureus (6.7%), Enterobacter cloacae (6.1%), Haemophilus parainfluenzae (4.9%), Klebisiella pneumoniae (3.7%), Methicillin-resistant Staphylococcus aureus (MRSA) (3.7%), Pseudomonas aeruginosa (2.5%), Escherichia coli (1.8%), Streptococcus pneumoniae (1.8%), and Haemophilus influenzae (1.2%) were found in the sputum. The pathogen detection rate in the present study was 34.3% (56/163). In patients with preoperative chemotherapy and chemoradiotherapy, the indigenous Neisseria and Streptococcus species were significantly decreased (P= 0.04 and P= 0.04). However, the detection rates of pathogenic bacteria were not associated with preoperative treatments (all P> 0.07). There was not a significant difference of hospital stay between the sputum-monitored patients and unmonitored patients (35.5 vs. 49.9 days; P= 0.08). Patients undergoing preoperative treatments exhibited a significant decrease of indigenous bacteria, indicating that the treatment altered the bacterial flora of their sputum. This finding needs to be confirmed in large-scale independent studies or well-designed multicenter studies.

Use of PIXE/PIGE for sequential Ca and F measurements in root carious model

The progress of caries has conventionally been evaluated by checking changes in mineral density using transverse microradiography (TMR). Recent advances have seen development of a new measurement system, using in-air micro proton induced X-ray/gamma-ray emission (PIXE/PIGE). PIXE/PIGE enables analysis of distributions and concentrations of multiple mineral elements in a carious lesion. The aim of this study was to evaluate the effectiveness of PIXE/PIGE for investigating the development of root caries. In summary, we successfully established a multi-elemental sequential measuring method using in-air micro-PIXE/PIGE to identify the dynamic distributions and concentrations of Ca and F in human root dentin. The PIXE/PIGE potentially offers a useful advantageous technique for studying carious development by using as a combination with conventional techniques such as TMR and Micro-computed tomography (µCT).

Prognostic and clinical impact of sarcopenia in esophageal squamous cell carcinoma

Recently, depletion of skeletal muscle mass (sarcopenia) has been linked to poor prognosis in several types of cancers, but has not been investigated in esophageal squamous cell carcinoma (ESCC). This retrospective study investigates the relationship between sarcopenia and clinical outcome in ESCC patients treated by surgical resection or definitive chemoradiation therapy (dCRT). The study was retrospectively conducted in a single academic hospital in Kumamoto, Japan, and involved 325 ESCC patients (256 surgical cases and 69 dCRT cases) treated between April 2005 and April 2011. Skeletal muscle mass was quantified by radiologic measures using standard computed tomography scans. The skeletal muscle tissue in the 325 ESCC patients was distributed as follows: mean: 47.10; median: 46.88; standard deviation (SD): 7.39; range: 31.48-71.11; interquartile range, 46.29-47.90. Skeletal muscle tissue was greater in male patients than in female patients (P < 0.0001), but was independent of other clinical and tumor features. Sarcopenia was not significantly associated with overall survival (log rank P = 0.54). Lymph node involvement significantly altered the relationship between sarcopenia and survival rate (P for interaction = 0.026). Sarcopenia significantly reduced the overall survival of patients without lymph node involvement (log rank P = 0.035), but was uncorrelated with overall survival in patients with lymph involvement (log rank, P = 0.31). The anastomosis leakage rate was significantly higher in the sarcopenia group than in the non-sarcopenia group (P = 0.032), but other surgical complications did not significantly differ between the two groups. Sarcopenia in ESCC patients without lymph node involvement is associated with poor prognosis, indicating sarcopenia as a potential biomarker for identifying patients likely to experience an inferior outcome. Moreover, sarcopenia was associated with anastomosis leakage but no other short-term surgical outcome.

Modified gastric pull-up reconstructions following pharyngolaryngectomy with total esophagectomy

Reconstruction following pharyngolaryngectomy with total esophagectomy is a challenging surgery to perform. Between April 2008 and August 2012, three types of modified gastric pull-up reconstruction procedures, including a gastric tube creation combined with a free jejunal transfer (n = 7), elongated gastric tube creation with vascular anastomoses (n = 2) and pedunculated gastric tube creation with Roux-en-Y anastomosis (n = 5), were performed after pharyngolaryngectomy with total esophagectomy. To clarify feasibility of these reconstructive methods, we retrospectively analyzed the short-term outcomes. There were no graft failures. Salivary fistulae were observed in two cases after high pharyngoenteral anastomoses due to oropharyngeal extension of hypopharyngeal cancers. Overall morbidity rate was 21.4%, and no deaths occurred. Although the operation time was shortest for pedunculated gastric tube reconstructions, morbidity rates were similar among all methods. All three types of modified gastric pull-up reconstruction procedures can be performed safely. We can choose one of these methods according to the tumor status and the patient condition, understanding advantages and disadvantages of each procedure.

Plasma CD147 reflects histological features in patients with lupus nephritis

OBJECTIVE

A glycosylated transmembrane protein, CD147, has been implicated in regulating lymphocyte responsiveness and leukocyte recruitment. As lupus nephritis (LN) often follows a relapsing-remitting disease course, accurate understanding of the disease activity would be extremely helpful in improving prognosis. Unfortunately, neither clinical nor serological data can accurately reflect the histological features of LN. The present study investigated whether CD147 can accurately predict pathological features of LN.

METHODS

Plasma and spot urine samples were collected from 64 patients who underwent renal biopsy between 2008 and 2011. Disease activity for LN tissues was evaluated using the biopsy activity index, and compared to levels of biomarkers including CD147.

RESULTS

In LN tissues, CD147 induction was striking in injured glomeruli and infiltrating inflammatory cells, but not in damaged tubules representing atrophy. Plasma CD147 levels accurately reflected the histological disease activity. However, prediction using a single molecule would be quite difficult because of the complex pathogenesis of LN. The diagnostic accuracy of multiplex parameters indicated that the combination including plasma CD147 might yield excellent diagnostic abilities for guiding ideal LN therapy.

CONCLUSION

Plasma CD147 levels might offer useful insights into disease activity as a crucial biomarker in patients with LN.

Radiofrequency ablation for pulmonary metastases from esophageal squamous cell carcinoma

Radiofrequency ablation (RFA) is increasingly being used for the treatment of intrathoracic malignancies. Although RFA has been found to be promising in the treatment of lung metastases from some types of neoplasms, little is known concerning its clinical significance in the treatment of pulmonary metastasis from esophageal squamous cell carcinoma (ESCC). This retrospective study evaluated the feasibility, safety, and effectiveness of computed tomography-guided RFA for pulmonary metastasis from ESCC. A series of 10 ESCC patients with 17 pulmonary tumors were included. Correct placement of the ablation device into the target tumor proved to be feasible in all tumors (100%). The mean visual analog scale score, with values that ranged from 0 (no pain) to 10 (worst pain possible), was 1. This suggested that this procedure was well tolerated. No procedure-related deaths occurred. A pneumothorax needing drainage was a major complication in two patients. Local control of ablated tumor lasting for at least 1 year was achieved in 10 (83%) of 12 assessable tumors. Although locoregional recurrences developed in two tumors, these lesions could be recontrolled by repeat treatment with RFA. Three patients died of recurrent disease. The predicted 1- and 2-year overall survival rates after lung RFA were 77.8% and 62.2%, respectively. Percutaneous computed tomography-guided RFA yielded relatively high levels of local control in patients with pulmonary metastases from ESCC and was associated with an acceptable level of complications. It was concluded that a prospective study will be necessary to evaluate the effectiveness of a combination of systemic therapy and RFA for ESCC lung metastases.

CD44s signals the acquisition of the mesenchymal phenotype required for anchorage-independent cell survival in hepatocellular carcinoma

Background:

Circulating tumour cells (CTCs) have an important role in metastatic processes, but details of their basic characteristics remain elusive. We hypothesised that CD44-expressing CTCs show a mesenchymal phenotype and high potential for survival in hepatocellular carcinoma (HCC).

Methods:

Circulating CD44⁺CD90⁺ cells, previously shown to be tumour-initiating cells, were sorted from human blood and their genetic characteristics were compared with those of tumour cells from primary tissues. The mechanism underlying the high survival potential of CD44-expressing cells in the circulatory system was investigated in vitro.

Results:

CD44⁺CD90⁺ cells in the blood acquired epithelial–mesenchymal transition, and CD44 expression remarkably increased from the tissue to the blood. In Li7 and HLE cells, the CD44^high population showed higher anoikis resistance and sphere-forming ability than did the CD44^low population. This difference was found to be attributed to the upregulation of Twist1 and Akt signal in the CD44^high population. Twist1 knockdown showed remarkable reduction in anoikis resistance, sphere formation, and Akt signal in HLE cells. In addition, mesenchymal markers and CD44s expression were downregulated in the Twist1 knockdown.

Conclusions:

CD44s symbolises the acquisition of a mesenchymal phenotype regulating anchorage-independent capacity. CD44s-expressing tumour cells in peripheral blood are clinically important therapeutic targets in HCC.

Influence of preoperative docetaxel, cisplatin, and 5-fluorouracil on the incidence of complications after esophagectomy for resectable advanced esophageal cancer

A limited number of patients with resectable advanced esophageal cancer can be cured by surgery alone. Although a regimen that consists of docetaxel, cisplatin, and 5-fluorouracil (DCF) is a potential preoperative chemotherapy (PCT) option for squamous cell carcinoma of the esophagus, the influence of DCF on subsequent esophagectomies remains unclear. A total of 80 patients who received preoperative DCF chemotherapy, and 174 patients who did not receive any preoperative treatment were retrospectively analyzed. There were no treatment-related deaths. No delays in surgery due to adverse events related to DCF were reported. Although patients who received PCT had significantly more advanced cancers and worse preoperative conditions, the incidence rates of complications did not increase. Although the frequency of severe complications was significantly higher in patients who received PCT, this treatment was not an independent factor for the occurrence of severe complications. PCT with DCF did not negatively affect subsequent esophagectomies with regard to the frequency of complications.

Methylation levels of LINE-1 in primary lesion and matched metastatic lesions of colorectal cancer

Background:

LINE-1 methylation level is a surrogate marker of global DNA methylation. LINE-1 methylation in primary colorectal cancers (CRCs) is highly variable and strongly associated with a poor prognosis. However, no study has examined LINE-1 methylation levels of metastatic CRCs in relation to prognosis or assessed the heterogeneity of LINE-1 methylation level within the primary CRCs.

Methods:

Pyrosequencing was used to quantify LINE-1 methylation level in 42 liver metastases, 26 matched primary tumours, and 6 matched lymph node (LN) metastases. KRAS, BRAF, and PIK3CA mutation status and microsatellite instability (MSI) status were also examined.

Results:

The distribution of LINE-1 methylation level in liver metastases was as follows: mean, 67.3; range, 37.1–90.1. Primary tumours showed LINE-1 methylation levels similar to those of matched liver and LN metastases. The difference in LINE-1 methylation level between superficial areas and invasive front areas was within 7.0 in all six cases evaluated. Prognostic impact of LINE-1 hypomethylation in liver metastases on overall survival was not observed. The concordance rate was 94% for KRAS, 100% for BRAF, 88% for PIK3CA, and 97% for MSI.

Conclusion:

Alteration of LINE-1 methylation level may occur in early CRC tumorigenesis, and the LINE-1 methylation level is relatively stable during CRC progression.

Echocardiographic characteristics and causal mechanism of physiologic mitral regurgitation in young normal subjects

BACKGROUND

It has become evident that mitral regurgitation (MR) is not uncommon in healthy subjects, and Doppler color flow mapping is a technique that imparts important information relevant to its detection.

HYPOTHESIS

Using transthoracic echocardiography, this study evaluated the mechanism of physiologic MR in young normal subjects using transthoracic echocardiography.

METHODS

The study population consisted of 48 young normal subjects (mean 21 +/- 5 years) with MR (physiologic MR group), 40 age-matched young normal subjects (mean 20 +/- 5 years) without MR (control group), 45 patients (mean 41 +/- 15 years) with mitral valve prolapse with MR (MVP group), and 27 patients (mean 59 +/- 13 years) with ruptured chordae tendineae (rupture group).

RESULTS

Men were predominant in the rupture group, whereas there were no significant gender differences in the other three groups. Left ventricular end-diastolic dimension and left atrial systolic dimension were slightly smaller in the physiologic MR group than in the control group, but were significantly smaller than those in the MVP and rupture groups. The ratio of the maximum anteroposterior diameter to the maximum transverse diameter on chest radiography and the ratio of the short- to long-axis diameter of the left ventricular cavity at end diastole, determined from two-dimensional short-axis echocardiogram, were significantly lower in the physiologic MR group than in the other three groups. Mitral regurgitation occurred more frequently at the posteromedial commissural site in the physiologic MR and MVP groups, whereas there was no preference for location in the rupture group. Early systolic MR was often observed in the physiologic MR group, whereas pansystolic MR was common in the MVP and rupture groups.

CONCLUSION

As a causal mechanism for physiologic MR detected in young normal subjects, "flattening" of the thorax during growth may cause morphologic abnormalities of the left atrial and ventricular cavities, resulting in spatial imbalance of the mitral complex and resulting in malcoaptation of the valve.

Arterial reconstruction in Buerger's disease: by-pass to disease-free collaterals

BACKGROUND

Arterial reconstructions for ischemia in patients with Buerger's disease are technically challenging. This retrospective review was conducted to identify the critical factor for a successful outcome in bypass surgery for Buerger's disease.

METHODS

DESIGN OF STUDY

retrospective review.

SETTING

University hospital, hospitalized patients.

PATIENTS

since 1993, we performed 10 arterial reconstructions in 8 patients with Buerger's disease. There were 8 tibial artery bypasses and 2 collateral artery bypasses. One bypass was performed in the upper extremity.

INTERVENTIONS

bypass surgery with autogenous vein graft.

MAIN OUTCOMES MEASUREMENTS

graft patency.

RESULTS

Over a mean follow-up period of 41.8 months, there were 3 graft occlusions. Of these, 2 were of bypasses to a patent but diseased tibial artery. One graft was occluded due to a toe stenosis which had been previously detected. The 2 collateral artery bypasses were patent at the last follow-up.

CONCLUSIONS

In Buerger's disease, distal arterial reconstruction is frequently necessary to prevent ischemic limb loss. Collateral artery bypass is an option when the main arteries are affected by the disease. A patent but diseased artery should be avoided as a target for reconstruction.

Staged vascular reconstruction along with repeatedly performed angiography to prevent ischemic limb loss with Buerger's disease: report of a case

An aggressive approach to vascular reconstruction should be adopted in patients with Buerger's disease and peripheral ischemia who are often young and otherwise active. A patient with severe Buerger's disease is reported who was treated successfully by complete vascular reconstruction with staged bypass surgery while also performing repeated angiography to preserve the foot function. A 48-year-old man with Buerger's disease presented with necrosis of the foot. Angiography showed occlusion of the right distal external iliac artery and no runoff below the knee. Repeated angiography after performing a lumbar sympathectomy demonstrated patency of the distal portion of the deep femoral artery. Angiography was again performed after a reconstruction of the deep femoral artery and patency of the anterior tibial artery was observed. A staged bypass operation on the tibial artery was therefore able to achieve a prompt healing of both the toe ulcers and plantar wound.

Inflammatory solitary iliac artery aneurysms: a report of two cases

Inflammatory abdominal aortic aneurysms are associated with atherosclerosis, which are characterized by specific clinical manifestation. We treated two patients with unilateral solitary iliac artery aneurysms with perianeurysmal fibrosis which compressed the ureter resulting in ipsilateral hydronephrosis. After the iliac artery aneurysm was repaired with a prosthetic graft, the hydronephrosis resolved. Microscopically, there was clear evidence of atherosclerosis in one case. There was a characteristic inflammatory reaction around the adventitia in both aneurysms. Localized iliac perianeurysmal fibrosis has not been particularly described. The clinicopathologic similarities between these cases and inflammatory abdominal aortic aneurysms suggest the same pathogenesis.

Identification of the critical spinal arteries with F wave-polysynaptic response complex monitoring: an experimental study

PURPOSE

The main cause of paraplegia after surgery for descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms is spinal cord ischemia caused by ligation of the critical spinal arteries that are associated with the great radicular artery (GRA). In this experimental study, we attempted to identify the critical spinal arteries with F wave-polysynaptic response complex (FPC) monitoring. The FPC, which we are using as a monitor of spinal cord ischemia, is myogenic potentials evoked by the tibial nerve stimulation through the anterior horn cells.

METHOD

In 18 rabbits, infrarenal lumbar arteries were clamped until there was an FPC amplitude reduction (FPCAR) of at least 60%. The rabbits were classified according to the number of arteries clamped to produce the FPCAR (group A, 1 artery; group B, 2 arteries; group C, 3 arteries). Selective angiography of each lumbar artery was performed in all rabbits.

RESULTS

An FPCAR was observed in all 18 rabbits. In all nine rabbits in group A, the FPCAR was caused by the clamping of one particular lumbar artery. The GRA was shown by means of selective angiography to originate directly from this lumbar artery. In the nine rabbits in groups B and C, 11 FPCARs were observed. Of these, nine FPCARs in nine rabbits were caused by the clamping of lumbar arteries that included the vessel from which the GRA originated.

CONCLUSION

Temporary clamping of lumbar arteries with FPC monitoring can be used as a means of detecting the critical spinal arteries from which the GRA originates.

Kindling of the midbrain periaqueductal gray in rats

We investigated the role of midbrain periaqueductal gray matter (PAG) in the manifestation of generalized seizures by administering electrical stimulation to this area in rats. Electrical stimulation of 60 Hz biphasic square pulses of a 1-s duration administered to the PAG-induced convulsive responses in the following order: (1) Type I, running (stimulus intensity; range 50--200 microA, mean 73.1 microA) without afterdischarge (AD), (2) Type IIa, running (stimulus intensity; range 50--300 microA, mean 111.8 microA) with AD at the PAG and the amygdala (AMY), and (3) Type IIb, generalized tonic--clonic seizures (GTCS) (stimulus intensity; range 50--250 microA, mean 182.1 microA) with AD at the PAG and AMY. Twenty daily PAG stimulations at the non-GTCS inducing threshold failed to produce kindling. However, 20 daily PAG stimulations at the GTCS threshold produced progressive AD spread involving the motor cortex, and progressive changes in the behavioral seizure pattern. These findings indicate that the PAG can be effectively kindled. However, PAG kindling has no apparent influence on subsequent AMY kindling.

HET0016, a potent and selective inhibitor of 20-HETE synthesizing enzyme

The present study examined the inhibitory effects of N-hydroxy-N'-(4-butyl-2-methylphenyl)-formamidine (HET0016) on the renal metabolism of arachidonic acid by cytochrome P450 (CYP) enzymes. HET0016 exhibited a high degree of selectivity in inhibiting the formation of 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE) in rat renal microsomes. The IC(50) value averaged 35+/-4 nM, whereas the IC(50) value for inhibition of the formation of epoxyeicosatrienoic acids by HET0016 averaged 2800+/-300 nM. In human renal microsomes, HET0016 potently inhibited the formation of 20-HETE with an IC(50) value of 8.9+/-2.7 nM. Higher concentrations of HET0016 also inhibited the CYP2C9, CYP2D6 and CYP3A4-catalysed substrates oxidation with IC(50) values of 3300, 83,900 and 71,000 nM. The IC(50) value for HET0016 on cyclo-oxygenase activity was 2300 nM. These results indicate that HET0016 is a potent and selective inhibitor of CYP enzymes responsible for the formation of 20-HETE in man and rat.

Causes of late mortality in patients with disabling intermittent claudication

The long-term prognosis of patients suffering from intermittent ischemic claudication is reportedly worse than that of the normal population. The outcome of patients with ischemic claudication admitted to hospital was reviewed retrospectively to identify the causes of late death. The cumulative survival rates for patients with claudication were 94.6% at 1 year, 79.4% at 3 years, 67.3% at 5 years and 37.4% at 10 years. The 3 major causes of death, that is, ischemic heart disease, malignancy, and cerebrovascular accident, were equally common. The younger patients tended to die of ischemic heart disease, whereas the older patients died of cerebrovascular accidents. Malignancies caused a similar number of late deaths in all age groups. These results suggest that specific care should be given to patients with intermittent claudication based on the age-related causes of death.

Convulsive seizures induced by N-methyl-D-aspartate microinjection into the mesencephalic reticular formation in rats

Effects of microinjections of a single 2 or 10 nmol dose of N-methyl-D-aspartate (NMDA) into the unilateral mesencephalic reticular formation (MRF) on behavior and electroencephalogram were examined in rats (n=18) during a 15 min period (Exp. 1), and subsequent effects of sound stimulation with key jingling applied at 15, 30, and 45 min after the injections were observed (Exp. 2). The microinjections of 2 nmol dose of NMDA (n=10) induced hyperactivity (9 of 10 rats) and running/circling (8 of 10 rats) in Exp. 1, and hyperactivity (3 of 10 rats) in Exp. 2. Moreover, the microinjections of 10 nmol dose of NMDA (n=8) induced not only hyperactivity (8 of 8 rats) and running/circling (7 of 8 rats) but also generalized tonic-clonic seizures (GTCS) (5 of 8 rats) in Exp. 1; these seizure patterns were also elicited by sound stimulation in Exp. 2. The seizure patterns were accompanied by electroencephalographic seizure discharges in the MRF and the motor cortex. In contrast, the control group rats (n=10) which received a single dose of saline microinjection into the unilateral MRF showed no behavioral or electroencephalographic changes in both Exp. 1 and 2. These findings suggest that the MRF has an important role in the development of GTCS, which follows hyperactivity and running/circling, and that potentiation of excitatory neurotransmission in the MRF participates in the development of audiogenic seizures as well as GTCS.

Anomalies of inferior vena cava and left renal vein: risks in aortic surgery

Although most aortic surgery is now routinely performed without incident, major venous anomalies can cause unexpected bleeding. In the last 6 years, 4 of 166 patients undergoing abdominal aortic surgery at our institution were found to have a major venous anomaly, including a double inferior vena cava (2), a preaortic iliac vein confluence (1), and a circumaortic renal collar (1). The 3 men and 1 woman had a mean age of 62.3 years (range, 56 to 68 years). All four patients underwent surgery for an abdominal aortic aneurysm. Preoperative imaging revealed all of the venous anomalies except for the renal collar. Unexpected venous injuries complicated the operation in one patient who had a double inferior vena cava and an inflammatory abdominal aortic aneurysm and in the patient with the circumaortic renal collar. Major venous anomalies are rarely encountered in patients undergoing aortic surgery. Preoperative assessment and intraoperative awareness are important to prevent unexpected venous injuries. Patients with an anomaly of the left renal vein and an inflammatory abdominal aortic aneurysm are at a particularly high risk.

Dendritic translocation of the rat ferritin H chain mRNA

To elucidate the mechanism regulating the selective transport of mRNAs to synaptic sites, we compared the synaptosomal mRNAs with those from the forebrain using the differential display method. The ferritin H chain mRNA was found to be highly enriched in the synaptosomes. In situ hybridization for the ferritin H chain mRNA in the cultured dissociated neurons and in the hippocampal brain slices demonstrated its existence in the dendritic region. These data clearly indicate the selective translocation of the ferritin H chain mRNA into the dendrites and suggested the local expression of ferritin at the synapse.

Rupture of infected pseudoaneurysms in patients with implantable ports for intra-arterial infusion chemotherapy

Intra-arterial hepatic chemotherapy via implantable reservoirs is being used increasingly. In our department, five patients have undergone emergency surgery since 1991 because of rupture of an infected pseudo-aneurysm at the site of entry of the catheter. Surgical procedures included removal of the catheter and the reservoir, and closure of the affected artery with or without reconstruction. Of these patients, three (60%) died from uncontrollable sepsis. The poor prognosis emphasizes the need, in patients with carcinoma, for strict aseptic technique and hemostasis at the time of catheter placement, and for careful device maintenance.

Simultaneous repair of arch and abdominal aortic aneurysms. A simple new technique using a temporary bypass graft

OBJECTIVE

Atherosclerotic aneurysms in the aortic arch are associated with abdominal aortic aneurysms in up to 37% of cases. We have developed a single-stage approach to the repair of both aneurysms using a temporary bypass.

SUBJECTS

Since November 1996, 5 patients underwent simultaneous repair of aneurysms in the aortic arch and in the infrarenal abdominal aorta, using a new temporary bypass graft technique. Entire arch replacement with simultaneous abdominal aortic aneurysmectomy was performed in one patient. The other 4 patients underwent distal hemi-arch replacement distal from the orifice of the brachiocephalic artery with simultaneous repair of the abdominal aortic aneurysm.

METHOD

For the entire arch replacement procedure, blood flow to all major branches of the aortic arch was established using a bifurcated graft. This graft anastomosed to the ascending aorta was used as the proximal inflow of the temporary bypass graft. For the hemi-arch replacement procedure, the proximal inflow segment of the temporary bypass graft was anastomosed to the brachiocephalic artery. In both cases, the distal outflow segment of the temporary bypass graft was the graft used for repair of the abdominal aortic aneurysm. In order to prevent any clamp injury, Teflon felt was tightly wrapped around the aorta before the clamp was applied.

RESULTS

Evaluation of the hemodynamic parameters measured during cross-clamping of the aortic arch revealed stable distal perfusion to the visceral organs and no excessive increase in cardiac afterload. All patients had an uneventful postoperative course and were discharged within 1 month of surgery.

CONCLUSION

Our temporary bypass method is recommended for simultaneous replacement of aneurysms in the aortic arch and the abdominal aorta.

Retrocaval ureter and preaortic iliac venous confluence in a patient with an abdominal aortic aneurysm

Anomalous anatomic location of a large venous system poses a potential hazard in aortic operations. We encountered a patient with an infrarenal abdominal aortic aneurysm who was also found at preoperative contrast-enhanced computed tomography to have a retrocaval right ureter and a preaortic iliac vein confluence. This combined anomaly has not previously been reported except for one postmortem case. As abdominal aortic surgery is currently performed routinely, care must be taken to avoid injury to surrounding organs due to rare anatomic anomalies.

Molecular typing of methicillin-resistant Staphylococcus aureus in a university teaching hospital

Plasmid analysis and pulsed-field gel electrophoresis (PFGE) were used to study the epidemiologic relationship among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at Tokyo Medical and Dental University Hospital. We found that 263 of 276 MRSA isolates had plasmids, which could be classified into 30 different patterns according to the number and plasmid molecular weight. Strains which harboured a single plasmid of approximately 13.4 Mds in molecular weight were the most numerous (55.7% of the isolates). These strains were isolated from 14 of 17 hospital wards. The largest number of strains with this plasmid pattern (33 strains) were isolated from a single ward. PFGE typing was then performed to further confirm the relationships among these 33 strains. The PFGE banding patterns of these strains were highly similar. The antibiogram profiles of these strains were also correlated with the PFGE pattern. Thus, the results suggest that these strains are epidemiologically related and spread throughout the ward. Combined plasmid analysis and PFGE were effective for discriminating the various MRSA isolates.

HSP90 has neurite-promoting activity in vitro for telencephalic and spinal neurons of chick embryos

We purified a protein from the extract of denervated chick muscle. The protein had neurite-promoting activity in vitro for the chick telencephalic neurons and spinal neurons. Partial amino acid sequencing and immunoblotting revealed that the protein was chick heat shock protein 90 (HSP90). Commercially available bovine HSP90 and recombinant chick HSP90 expressed in Escherichia coli also showed the same activity. Since HSP10 (GroES) and HSP60 (GroEL) exhibited no activity for neurite outgrowth in the same culture, this activity was specific to HSP90 among the heat shock proteins.

Abdominal aortic aneurysm repair with arterial branch reconstruction: utility of the temporary bypass technique

Between June 1992 and May 1996, five patients underwent an abdominal aortic aneurysm (AAA) repair with concomitant arterial branch reconstruction. All of the patients were males ranging in age from 55 to 66 years (mean: 61.6 years). The operations were performed for a localized abdominal aortic dissection, a pseudoaneurysm after patch angioplasty of a supraceliac AAA, a pararenal AAA, a total AAA with retrograde descending thoracic aortic dissection, and a supraceliac AAA after an infrarenal AAA repair. All patients underwent bilateral renal artery (RA) reconstruction. Three patients also had a concomitant reconstruction of the superior mesenteric artery ad celiac axis. The renal arteries were preferentially reconstructed. Visceral circulation during aortic cross-clamping was maintained via a temporary bypass circuit. A temporary division of the left renal vein was necessary in two patients. Overall, the mean renal ischemia time was 17.2min (range: 10 to 32 min). There was one perioperative death due to sepsis from a graft infection. Another patient died 6 months postoperatively due to pyothorax. One patient required postoperative hemodialysis for 1 month. Based on the above findings, the temporary bypass technique is thus considered to be useful for maintaining physiologic organ perfusion during aortic clamping without the need to use any complicated devices.