"KAIZEN" method realizing implementation of deep-learning models for COVID-19 CT diagnosis in real world hospitals

Numerous COVID-19 diagnostic imaging Artificial Intelligence (AI) studies exist. However, none of their models were of potential clinical use, primarily owing to methodological defects and the lack of implementation considerations for inference. In this study, all development processes of the deep-learning models are performed based on strict criteria of the "KAIZEN checklist", which is proposed based on previous AI development guidelines to overcome the deficiencies mentioned above. We develop and evaluate two binary-classification deep-learning models to triage COVID-19: a slice model examining a Computed Tomography (CT) slice to find COVID-19 lesions; a series model examining a series of CT images to find an infected patient. We collected 2,400,200 CT slices from twelve emergency centers in Japan. Area Under Curve (AUC) and accuracy were calculated for classification performance. The inference time of the system that includes these two models were measured. For validation data, the slice and series models recognized COVID-19 with AUCs and accuracies of 0.989 and 0.982, 95.9% and 93.0% respectively. For test data, the models' AUCs and accuracies were 0.958 and 0.953, 90.0% and 91.4% respectively. The average inference time per case was 2.83 s. Our deep-learning system realizes accuracy and inference speed high enough for practical use. The systems have already been implemented in four hospitals and eight are under progression. We released an application software and implementation code for free in a highly usable state to allow its use in Japan and globally.

Isolated sphenoid sinus opacification is often asymptomatic and is not referred for otolaryngology consultation

Isolated sphenoid sinus opacifications (ISSOs) are clinically important because they can lead to serious complications. However, some patients with ISSOs are asymptomatic, and not all patients are properly referred to the otolaryngology department. Because past studies of ISSOs focused only on patients who received treatment, in this study we selected ISSO cases based on radiology reports, then determined whether these patients had symptoms and were appropriately referred for specialty care. We conducted a retrospective analysis of data collected from patients who underwent computed tomography or magnetic resonance imaging from January 2007 to March 2017 at Osaka General Medical Center. We searched for the terms “sphenoid” or “sphenoidal” using F-REPORT to identify patients who had a sphenoid disease. We checked all selected images and diagnosed ISSOs. Examination of 1115 cases revealed 223 cases of ISSOs, of whom 167 (74.9%) were asymptomatic. We categorized patients with ISSOs into four groups: inflammation, mucocele, fungal diseases, and unclassifiable; the final category was used when edges were irregular or complete opacity was encountered. In the unclassifiable group, the majority of cases required otolaryngology consultation, but 37 of 47 unclassifiable patients did not have an otolaryngology visit. ISSOs are often identified by chance on imaging tests performed by non-otolaryngologists. However, our study revealed that many patients with ISSOs who should be treated by otolaryngologists were not referred to the otolaryngology department. Accordingly, it is important to promote awareness of the disease among other types of clinicians.

Serum immunoglobulin G antibody titer to Fusobacterium nucleatum is associated with unfavorable outcome after stroke

Stroke can be a cause of death, while in non-fatal cases it is a common cause of various disabilities resulting from associated brain damage. However, whether a specific periodontal pathogen is associated with increased risk of unfavorable outcome after stroke remains unknown. We examined risk factors for unfavorable outcome following stroke occurrence, including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset (favorable = score 0 or 1; unfavorable = score 2-6). The associations of risk factors with unfavorable outcome, including serum titers of IgG antibodies to 16 periodontal pathogens, were examined. Logistic regression analysis showed that the initial National Institutes of Health stroke scale score [odds ratio (OR) = 1·24, 95% confidence interval (CI) = 1·18-1·31, P < 0·001] and C-reactive protein (OR = 1·29, 95% CI = 1·10-1·51, P = 0·002) were independently associated with unfavorable outcome after stroke. Following adjustment with those, detection of the antibody for Fusobacterium nucleatum ATCC 10953 in serum remained an independent predictor of unfavorable outcome (OR = 3·12, 95% CI = 1·55-6·29, P = 0·002). Determination of the antibody titer to F. nucleatum ATCC 10953 in serum may be useful as a predictor of unfavorable outcome after stroke.

The identification of raft-derived tau-associated vesicles that are incorporated into immature tangles and paired helical filaments

AIMS

Neurofibrillary tangles (NFTs), a cardinal pathological feature of neurodegenerative disorders, such as Alzheimer's disease (AD) are primarily composed of hyper-phosphorylated tau protein. Recently, several other molecules, including flotillin-1, phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2] and cyclin-dependent kinase 5 (CDK5), have also been revealed as constituents of NFTs. Flotillin-1 and PtdIns(4,5)P2 are considered markers of raft microdomains, whereas CDK5 is a tau kinase. Therefore, we hypothesized that NFTs have a relationship with raft domains and the tau phosphorylation that occurs within NFTs.

METHODS

We investigated six cases of AD, six cases of other neurodegenerative diseases with NFTs and three control cases. We analysed the PtdIns(4,5)P2-immunopositive material in detail, using super-resolution microscopy and electron microscopy to elucidate its pattern of expression. We also investigated the spatial relationship between the PtdIns(4,5)P2-immunopositive material and tau kinases through double immunofluorescence analysis.

RESULTS

Pretangles contained either paired helical filaments (PHFs) or PtdIns(4,5)P2-immunopositive small vesicles (approximately 1 μm in diameter) with nearly identical topology to granulovacuolar degeneration (GVD) bodies. Various combinations of these vesicles and GVD bodies, the latter of which are pathological hallmarks observed within the neurons of AD patients, were found concurrently in neurons. These vesicles and GVD bodies were both immunopositive not only for PtdIns(4,5)P2, but also for several tau kinases such as glycogen synthase kinase-3β and spleen tyrosine kinase.

CONCLUSIONS

These observations suggest that clusters of raft-derived vesicles that resemble GVD bodies are substructures of pretangles other than PHFs. These tau kinase-bearing vesicles are likely involved in the modification of tau protein and in NFT formation.

[Effects of exposure frequency and background information on preferences for photographs of cars in different locations]

This study examined the influence of familiarity and novelty on the mere exposure effect while manipulating the presentation of background information. We selected presentation stimuli that integrated cars and backgrounds based on the results of pilot studies. During the exposure phase, we displayed the stimuli successively for 3 seconds, manipulating the background information (same or different backgrounds with each presentation) and exposure frequency (3, 6, and 9 times). In the judgment phase, 18 participants judged the cars in terms of preference, familiarity, and novelty on a 7-point scale. As the number of stimulus presentations increased, the preference for the cars increased during the different background condition and decreased during the same background condition. This increased preference may be due to the increase in familiarity caused by the higher exposure frequency and novelty resulting from the background changes per exposure session. The rise in preference judgments was not seen when cars and backgrounds were presented independently. Therefore, the addition of novel features to each exposure session facilitated the mere exposure effect.

Association between Cardiac Function and Pulmonary Function in Hypertensive Patients

OBJECTIVE: This study examined the association between cardiac function and pulmonary function in hypertensive patients. METHODS: Hypertensive patients without overt cardiovascular disease were enrolled ( n = 43; mean ± SD age 71 ± 9 years). Pulmonary function was measured by the percentage of predicted forced vital capacity (%FVC) and the ratio of 1 s forced expiratory volume (FEV1) to FVC (FEV1/FVC ratio). Left ventricular ejection fraction (LVEF) and the ratio of peak early diastolic transmitral flow (E) to peak early diastolic mitral annular velocity (e′) (E/e′ ratio) were assessed using echocardiography. RESULTS: Multiple linear regression analysis revealed that E/e′ was independently associated with %FVC and that LVEF was independently associated with FEV1/FVC ratio. Both LVEF and FEV1/FVC ratio were significantly lower in hypertensive former or current smokers than in hypertensive never smokers. CONCLUSIONS: Subclinical cardiac dysfunction was independently associated with reduced pulmonary function in hypertensive patients. Hypertensive patients with decreased pulmonary function may need preventive care to prevent the progression of heart failure.

Aortic root dilatation as a marker of subclinical left ventricular diastolic dysfunction in patients with cardiovascular risk factors

Consensus is lacking about the clinical importance of aortic root dilatation in assessment of the risk of cardiovascular disease. In this study, correlations between aortic root diameter and echocardiographic features of left ventricular (LV) diastolic function were investigated in 333 patients with at least one cardiovascular risk factor (hypertension, diabetes or dyslipidaemia) and preserved LV systolic function. Aortic root diameter was measured by M-mode echocardiography, and LV diastolic function was evaluated by measuring the peak velocity of early (E) and late (A) diastolic transmitral blood flow and peak early diastolic mitral annular velocity (E') by Doppler echocardiography. Linear regression analysis showed that, in men, age was not related to aortic root diameter but hypertension and LV hypertrophy were, whereas the converse was true in women. The parameters E, E/A ratio and E', were related to aortic root diameter in both sexes. Stepwise multiple regression analysis confirmed that E in women and E' in men were independently associated with aortic root diameter. It is concluded that aortic root dilatation might be a useful marker of subclinical LV diastolic dysfunction. Patients with preserved systolic function showing aortic root dilatation should, therefore, be given preventative therapy against LV diastolic heart failure.

Differences in Left Ventricular Diastolic Dysfunction between Eccentric and Concentric Left Ventricular Hypertrophy in Hypertensive Patients with Preserved Systolic Function

Left ventricular (LV) hypertrophy (LVH) may be eccentric or concentric (2 × LV posterior wall thickness relative to LV end-diastolic dimension ≤ 0.42 or > 0.42, respectively). The LV diastolic function between age-matched hypertensive patients with eccentric and concentric LVH was compared in the present study. Echocardiography was used to measure LV mass index (LV mass/body surface area; LVMI) as an index of LVH. LV diastolic function was assessed by measurements of peak early transmitral flow velocity ( E)/peak late transmitral flow velocity ( A) (the E/A ratio), peak early diastolic mitral annular velocity ( e′) and the E/e′ ratio. Although LVMI, E/A and e′ did not differ between the two groups, E/e′ was significantly higher (worse) in patients with concentric LVH (13.4 ± 5.4) than in those with eccentric LVH (11.1 ± 3.6). Among hypertensive patients with LVH, those with concentric LVH may, therefore, have more severe LV diastolic dysfunction than those with eccentric LVH even if their LVMIs, which reflect the degree of LVH, are similar.

Blockade of AT1 receptors protects the blood-brain barrier and improves cognition in Dahl salt-sensitive hypertensive rats

BACKGROUND

The present study tested the hypothesis that inappropriate activation of the brain renin-angiotensin system (RAS) contributes to the pathogenesis of blood-brain barrier (BBB) disruption and cognitive impairment during development of salt-dependent hypertension. Effects of an angiotensin II (AngII) type-1 receptor blocker (ARB), at a dose that did not reduce blood pressure, were also examined.

METHODS

Dahl salt-sensitive (DSS) rats at 6 weeks of age were assigned to three groups: low-salt diet (DSS/L; 0.3% NaCl), high-salt diet (DSS/H; 8% NaCl), and high-salt diet treated with ARB, olmesartan at 1 mg/kg.

RESULTS

DSS/H rats exhibited hypertension, leakage from brain microvessels in the hippocampus, and impaired cognitive functions, which were associated with increased brain AngII levels, as well as decreased mRNA levels of tight junctions (TJs) and collagen-IV in the hippocampus. In DSS/H rats, olmesartan treatment, at a dose that did not alter blood pressure, restored the cognitive decline, and ameliorated leakage from brain microvessels. Olmesartan also decreased brain AngII levels and restored mRNA expression of TJs and collagen-IV in DSS/H rats.

CONCLUSIONS

These results suggest that during development of salt-dependent hypertension, activation of the brain RAS contributes to BBB disruption and cognitive impairment. Treatment with an ARB could elicit neuroprotective effects in cognitive disorders by preventing BBB permeability, which is independent of blood pressure changes.

Hyperglycemia suppresses ABCA1 expression in vascular smooth muscle cells

Hyperglycemia is a major risk factor for atherosclerotic disease. The ATP-binding cassette transporter A1 (ABCA1) functions as a pivotal regulator of lipid efflux from cells to apolipoproteins and is thus involved in lowering the risk of atherosclerosis. In this study, we have examined the glucose-mediated regulation of the ABCA1 gene expression in vascular smooth muscle cells. ABCA1 expression was examined by real-time polymerase chain reaction (PCR), Western blot analysis, and reporter gene assay. The results showed that the expression of the ABCA1 mRNA and protein decreased after the cells were treated with 22.4 mM glucose for 48 h. The transcriptional activity of the ABCA1 promoter paralleled the endogenous expression of the ABCA1 gene. Next, we used inhibitors of certain signal transduction pathways to demonstrate that the glucose-induced ABCA1 suppression is sensitive to the p38-mitogen-activated protein kinase (MAPK) inhibitors. The expression of a constitutively active form of p38-MAPK in the cells inhibited the ABCA1 promoter activity, irrespective of the presence of glucose. A dominant-negative mutant of p38-MAPK abrogated the inhibitory effect of glucose on the ABCA1 promoter activity. These results indicate that the glucose-induced suppression of ABCA1 expression is partially mediated by the activation of the p38-MAPK pathway.

The expression of P-glycoprotein is increased in vessels with blood-brain barrier impairment in a stroke-prone hypertensive model

AIMS

We previously reported that the blood-brain barrier (BBB) function was impaired in vessels in the hippocampus in 3-month-old stroke-prone spontaneously hypertensive rats (SHRSP). In this study, we examined gene and protein expressions of P-glycoprotein, a representative efflux transporter of cerebral vessels, in the BBB-damaged hippocampal vessels of SHRSP and in the vessels of Wistar Kyoto (WKY) rats as controls, to clarify roles of the efflux transporter in the BBB-damaged vessels.

METHODS

The expression of P-glycoprotein in hippocampal and cortical samples was examined by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunoelectron microscopic techniques.

RESULTS

Real-time RT-PCR and Western blotting analyses revealed that the gene and protein expressions of P-glycoprotein were increased in the hippocampal samples of 3-month-old SHRSP compared with hippocampal samples of 3-month-old WKY rats or with cortical samples of SHRSP. The gene expression of P-glycoprotein was also increased in the hippocampal samples of 4-week-old SHRSP. Immunoelectron microscopic examination revealed that immunosignals of P-glycoprotein were seen in the luminal and ab-luminal cytoplasmic membranes of endothelial cells and the basal lamina, that the labelling density of P-glycoprotein in the vessel wall was higher in the hippocampus of 3-month-old SHRSP than in other groups and that the immunosignals of P-glycoprotein were occasionally co-located with those of albumin.

CONCLUSIONS

These findings indicate that the expression of P-glycoprotein is increased in BBB-damaged hippocampal vessels in hypertensive SHRSP compared with those in WKY rats.

Angiotensin type 1 receptor blockage improves ischemic injury following transient focal cerebral ischemia

Following cerebral ischemia, i.v. infusion of angiotensin II increases cerebral edema and mortality. Angiotensin type 1 receptor blockage should therefore improve acute cerebral ischemia. Left middle cerebral artery occlusion (120 min) followed by reperfusion was performed with the thread method under halothane anesthesia in Sprague-Dawley rats. Olmesartan (angiotensin type 1 receptor blocker; 0.01 or 0.1mumol/kg/h) was infused i.p. for 7 days following middle cerebral artery occlusion followed by reperfusion. Stroke index score, infarct volume, specific gravity, and brain angiotensin II and matrix metalloproteinases were quantified in the ischemic and non-ischemic hemispheres. Olmesartan treatment improved stroke index score, infarct volume, and cerebral edema in our cerebral ischemia model. In particular, stroke index score, infarct volume, and cerebral edema were reduced even with a low dose of olmesartan that did not decrease blood pressure. Paralleling these effects on cerebral ischemia, olmesartan treatment also reduced the reactive upregulation in brain angiotensin II, matrix metalloproteinase-2, matrix metalloproteinase-9, and membrane type 1-matrix metalloproteinase in the ischemic area. Angiotensin type 1 receptor stimulation may be one of the important factors that cause cerebral edema following cerebral ischemia, and that its inhibition may be of therapeutic advantage in cerebral ischemia.

Guttate morphoea in human T-cell lymphoma/lymphotrophic virus type-1 (HTLV-1) infection

A 62-year-old Japanese man presented with multiple small atrophic macules on the trunk and extremities. The lesions were discrete, oval in shape and enclosed by lilac ring. They were distributed in a Christmas tree distribution, reminiscent of pityriasis rosea. Skin biopsy showed increased collagen fibres in the dermis and invading subcutaneous tissue. The clinico-pathological features were consistent with guttate morphoea, a rare variant of localized scleroderma. Serological tests revealed a positive reaction to human T-cell lymphoma/lymphotropic virus type-1 infection.

Angelman syndrome associated with oculocutaneous albinism due to an intragenic deletion of the P gene

Angelman syndrome (AS) is a neurodevelopmental disorder characterized by mental retardation, speech impairment, ataxia, and happy disposition with frequent smiling. AS results from the loss of expression of a maternal imprinted gene, UBE3A, mapped within 15q11-q13 region, due to different mechanisms: maternal deletion, paternal UPD, imprinting center mutation, and UBE3A mutation. Deletion AS patients may exhibit hypopigmentation of skin, eye, and hair correlating with deletion of P gene localized in the distal part of Prader-Willi (PWS)/AS region. Our patient presented developmental delay, severe mental retardation, absence of speech, outbursts of laughter, microcephaly, ataxia, hyperactivity, seizures, white skin, no retinal pigmentation, and gold yellow hair. His parents were of African ancestry. The SNURF-SNRPN methylation analysis confirmed AS diagnosis and microsatellite studies disclosed deletion with breakpoints in BP2 and BP3. All of the 25 exons and flanking introns of the P gene of the patient, his father, and mother were investigated. The patient is hemizygous for the deleted exon 7 of the P gene derived from his father who is a carrier of the deleted allele. Our patient manifests OCA2 associated with AS due to the loss of the maternal chromosome 15 with the normal P allele, and the paternal deletion in the P gene. As various degrees of hypopigmentation are associated with PWS and AS patients, the study of the P gene in a hemizygous state could contribute to the understanding of its effect on human pigmentation during development and to disclose the presence of modifier pigmentation gene(s) in the PWS/AS region.

Association of SPINK5 gene polymorphisms with atopic dermatitis in the Japanese population

BACKGROUND

Netherton's syndrome (NS) is an autosomal recessive disorder characterized by trichorrhexis invaginata ('bamboo hair'), congenital ichthyosiform erythroderma and an atopic diathesis. NS has recently been shown to be due to a defect in the SPINK5 gene, encoding LEKTI, a 15-domain serine protease inhibitor. SPINK5 maps to chromosome 5q31-q32, and has been suggested to be a locus predisposing to atopy in general. Recently, coding polymorphisms in SPINK5 exons 13 and 14 have been reported to be associated with atopy, asthma and atopic dermatitis (AD).

OBJECTIVES

To examine whether these polymorphisms are also associated with AD in Japan.

METHODS

We characterized eight polymorphisms in SPINK5 exons 13 and 14 in 124 Japanese patients with AD and 110 healthy controls. The polymorphisms we examined were IVS12-26C-->T, IVS12-10A-->G, 1103A-->G (Asn368Ser, in exon 13), 1156G-->A (Asp386Asn, in exon 13), 1188T-->C (His396His, in exon 13), IVS13-50G-->A, 1258G-->A (Glu420Lys, in exon 14) and IVS14+19G-->A.

RESULTS

We found significant associations between seven of these polymorphisms and AD in Japanese patients.

CONCLUSIONS

This study confirms the previous suggestion of an association between SPINK5 and AD.

Combined use of percutaneous ethanol injection and radiofrequency ablation for the effective treatment of hepatocelluar carcinoma

Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) therapy are currently used for the treatment of hepatocellular carcinoma (HCC). The purpose of this study was to evaluate the usefulness of combination therapy of PEI and RFA (PEI-RFA). Seventy-three patients with biopsy-proven HCC and liver cirrhosis underwent RFA after a bolus injection of ethanol into HCC. The volume of coagulated necrosis in the liver caused by PEI-RFA was estimated and compared with that by RFA alone. Coagulated necrosis areas in the liver of patients treated with PEI-RFA were significantly larger than those of patients treated with RFA alone. In PEI-RFA group, the volume of coagulated necrosis was significantly correlated with the amounts of ethanol injected into HCC. No major complications were observed during and after the PEI-RFA treatment. These results indicate that PEI-RFA is more effective than RFA alone and can make dramatic improvement of therapeutic effects in RFA therapy for HCC with fewer sessions of treatments. Therefore, PEI-RFA is considered to be a practical and promising option and may open up new avenues for the treatment of HCC.

Plaque rupture on the carotid artery observed by Doppler ultrasonography--a case report

Plaque rupture may play an important role in acute cerebral events. Recent technological advances in ultrasonographic systems provide a feasible diagnostic modality of atherosclerotic lesion by clearly visualizing flow conditions and vessel morphology. A 58-year-old man with chronic renal failure underwent duplex Doppler ultrasound in which ruptured plaque on carotid arterial wall was imaged. Color Doppler imaging showed that the plaque shoulder at the proximal site was hit by forward flow to the brain and ruptured. Curling flow in the inner space of the plaque was observed. Carotid arteriography at the corresponding site of ruptured plaque revealed the space within the plaque similarly contrasted. A magnetic resonance imaging of brain performed after identifying plaque rupture revealed small cerebral infarcts at the cerebral cortex. Plaque rupture could be demonstrated by color Doppler imaging at the proximal edge of plaque and curling flow in the intraplaque space may have released small thrombi to vessel lumen. Plaque rupture of the carotid artery may play an important role in the development of small cerebral infarction.

Association of plasma adrenomedullin with carotid atherosclerosis in chronic ischemic stroke

Adrenomedullin is a potent vasodilator peptide exerting anti-atherosclerotic actions in vitro. We investigated the impact of the severity of atherosclerosis on plasma mature-adrenomedullin (m-AM) levels in 38 patients with chronic ischemic stroke. The variables of carotid artery atherosclerosis assessed using ultrasound measurement, blood pressure, and risk factors were related to m-AM levels. Severe atherosclerosis was associated with a further elevation of the increased m-AM level in patients with high systolic blood pressure. Even in patients with fewer risk factors, the presence of severe atherosclerosis was associated with an increased m-AM level. Thus, atherosclerosis elevates m-AM independent of the blood pressure level or presence of risk factors.

Angiotensin-converting enzyme inhibition with enalapril slows progressive intima-media thickening of the common carotid artery in patients with non-insulin-dependent diabetes mellitus

BACKGROUND AND PURPOSE

Whether angiotensin-converting enzyme (ACE) inhibitors have any clinically significant antiatherogenic effects in humans remains unproven. We undertook a prospective randomized clinical trial of 98 patients with non-insulin-dependent diabetes mellitus (NIDDM) to examine the efficacy of ACE inhibition with enalapril for preventing intima-media (IM) thickening of the carotid wall as measured ultrasonographically.

METHODS

Ninety-eight NIDDM patients were randomly assigned either to enalapril at 10 mg/d (n=48) or to a control group (n=50); the planned duration of the trial was 2 years. All patients were seen at baseline (study entry) and 2 subsequent formal annual evaluations, in addition to standard clinical management for NIDDM. IM thickening and vascular lumen diameters were determined for all patients on the basis of baseline and 2 subsequent annual evaluations with carotid ultrasonography. We performed an intent-to-treat analysis to assess changes in IM thickening over the course of the study.

RESULTS

Annual IM thickening measurements of the right and left common carotid arteries were 0.01+/-0.02 and 0.01+/-0.02 mm/y in the enalapril-treated group and 0.02+/-0.03 and 0.02+/-0.02 mm/y in the control group, respectively (P<0.05). From regression analysis, annual IM thickening was found to be predicted by enalapril use, sex, and insulin use (F(3,94)=3.86, P=0.012). When we controlled for these other variables, enalapril use reduced annual IM thickening of right and left common carotid arteries by 0.01+/-0.004 mm/y relative to the control group over the course of this study.

CONCLUSIONS

Long-term treatment with an ACE inhibitor (enalapril) slows progressive IM thickening of the common carotid artery in NIDDM patients.

Rapid differential endogenous plasminogen activator expression after acute middle cerebral artery occlusion

BACKGROUND AND PURPOSE

During focal cerebral ischemia, the microvascular matrix (ECM), which participates in microvascular integrity, is degraded and lost when neurons are injured. Loss of microvascular basal lamina antigens coincides with rapid expression of select matrix metalloproteinases (MMPs). Plasminogen activators (PAs) may also play a role in ECM degradation by the generation of plasmin or by MMP activation.

METHODS

The endogenous expressions of tissue-type plasminogen activator (tPA), urokinase (uPA), and PA inhibitor-1 (PAI-1) were quantified in 10-microm frozen sections from ischemic and matched nonischemic basal ganglia and in the plasma of 34 male healthy nonhuman primates before and after middle cerebral artery occlusion (MCA:O).

RESULTS

Within the ischemic basal ganglia, tissue uPA activity and antigen increased significantly within 1 hour after MCA:O (2P<0.005). tPA activity transiently decreased 2 hours after MCA:O (2P=0.01) in concert with an increase in PAI-1 antigen (2P=0.001) but otherwise did not change. The transient decrease in free tPA antigen was marked by an increase in the tPA-PAI-1 complex (2P<0.001). No significant relations to neuronal injury or intracerebral hemorrhage were discerned.

CONCLUSIONS

The rapid increase in endogenous PA activity is mainly due to significant increases in uPA, but not tPA, within the ischemic basal ganglia after MCA:O. This increase and an increase in PAI-1 coincided with latent MMP-2 generation and microvascular ECM degeneration but not neuronal injury.

Thrombin inhibition attenuates neurodegeneration and cerebral edema formation following transient forebrain ischemia

The disturbance of microcirculation following cerebral ischemia leads to an enlargement of cerebral infarct volume. Endogenous thrombin may play a role in this disturbance of microcirculation following cerebral ischemia. Therefore, the inhibition of thrombin may improve neurodegeneration and the accumulation of cerebral edema following cerebral ischemia in gerbils. The effects of thrombin inhibitor (argatroban) on cerebral ischemia were investigated in comparison with thromboxane A2 synthase inhibitor (ozagrel) and cyclooxygenase inhibitor (aspirin) following bilateral common carotid artery occlusion and reperfusion (CCA:O/R) in male Mongolian gerbils. This study consisted of three experiments: (1) morbidity and survival ratio (n=40 for each), (2) histopathology (n=12 for each), and (3) mean arterial blood pressure, local cerebral blood flow (CBF), and cerebral specific gravity (n=8 for each). Argatroban treatment improved survival ratio and stroke index, and decreased ischemically injured cell numbers in cortex and hippocampus and cerebral edema in cortex compared with aspirin and saline, in concert with the fast recovery of local CBF without reactive hyperemia following bilateral CCA:O/R. Ozagrel treatment also improved those factors compared with saline, in concert with the fast recovery of local CBF with reactive hyperemia. Aspirin treatment improved survival ratio and stroke index, and decreased ischemically injured cell numbers in cortex. Thrombin inhibition with argatroban decreases neurodegeneration and cerebral edema following bilateral CCA:O/R in gerbils.

Assessment of the presence and severity of esophagogastric varices by splenic index in patients with liver cirrhosis

PURPOSE

To determine whether spleen size is related to the severity of esophageal varices or associated gastric varices and liver functions in patients with cirrhosis.

METHOD

The authors retrospectively studied spleen size on CT (splenic index [SI] = length x width x height of the spleen), liver functions, and the results of esophagogastric endoscopy in 110 patients with cirrhosis. They also analyzed SI in 112 controls.

RESULTS

In controls, body weight, height, and age affected the SI. The SI in patients with uncompensated cirrhosis was greater compared with the SI in those with well-compensated disease (p = 0.0363). The SI in patients with esophageal varices was greater than in patients without esophageal varices (p<0.0001), but patients with and without gastric varices had similar SI values. The SI in patients with the red color signs (red wale marking, cherry red spot, and hematocystic spot) on esophageal varices or with risky varices (enlarged tortuous varices with beady, nodular, or tumor shape associated with red color signs) was greater than in patients without these signs (p = 0.0029 and p = 0.0030, respectively).

CONCLUSION

The SI is a good indicator of the severity of esophageal varices and hepatic functional reserve in patients with cirrhosis.

Alteration in left ventricular diastolic filling and accumulation of myocardial collagen at insulin-resistant prediabetic stage of a type II diabetic rat model

BACKGROUND

Considerable controversy exists regarding impairment of cardiac function in diabetes mellitus (DM). We investigated the serial changes in left ventricular (LV) histopathology and LV filling dynamics in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which have been established as an animal model of type II DM.

METHODS AND RESULTS

In 54 OLETF and 54 non-DM rats, body weight, blood pressure, heart rate, and transmitral pulsed Doppler examinations were performed from 5 to 47 weeks of age. An oral glucose tolerance test was performed at 10, 20, and 30 weeks of age. The hearts were excised for histopathology, including immunohistochemistry and histomorphometry of collagen, and measurement of hydroxyproline at baseline and each stage of developing DM. In the prediabetic stage (15 weeks of age), in which fast blood glucose remained normal, OLETF rats manifested mild obesity, postprandial hyperglycemia, and hyperinsulinemia, and early diastolic transmitral inflow exhibited prolonged deceleration time (OLETF, 59+/-10 ms versus non-DM, 49+/-8 ms, P<0.01) and low peak velocity (OLETF, 73+/-11 cm/s versus non-DM, 88+/-11 cm/s, P<0.01). Histopathology revealed extracellular fibrosis and abundant transforming growth factor-beta(1) receptor II in LV myocytes of OLETF rats. At 15 weeks of age, the ratio of collagen area/visual field of LV wall in OLETF rats (8.3+/-1.3%) was larger than that in non-DM rats (4.9+/-1.8%, P<0.0001), and the collagen content/dry tissue weight ratio of heart was significantly higher in OLETF (2. 0+/-0.5 mg/g) than non-DM (1.3+/-0.2 mg/g, P<0.01) rats.

CONCLUSIONS

A metabolic abnormality present in the prestage of type II DM may produce LV fibrosis and alteration in cardiac function.

Low-cost soft-copy display accuracy in the detection of pulmonary nodules by single-exposure dual-energy subtraction: comparison with hard-copy viewing

This study endeavored to clarify the usefulness of single-exposure dual-energy subtraction computed radiography (CR) of the chest and the ability of soft-copy images to detect low-contrast simulated pulmonary nodules. Conventional and bone-subtracted CR images of 25 chest phantom image sets with a low-contrast nylon nodule and 25 without a nodule were interpreted by 12 observers (6 radiologists, 6 chest physicians) who rated each on a continuous confidence scale and marked the position of the nodule if one was present. Hard-copy images were 7 x 7-inch laser-printed CR films, and soft-copy images were displayed on a 21-inch noninterlaced color CRT monitor with an optimized dynamic range. Soft-copy images were adjusted to the same size as hard-copy images and were viewed under darkened illumination in the reading room. No significant differences were found between hard- and soft-copy images. In conclusion, the soft-copy images were found to be useful in detecting low-contrast simulated pulmonary nodules.

Effects of troglitazone on collagen accumulation and distensibility of aortic wall in prestage of non-insulin-dependent diabetes mellitus of Otsuka Long-Evans Tokushima Fatty rats

We investigated the effect of troglitazone (TG) on aortic distensibility and histopathology at the preclinical stage in the non-insulin-dependent diabetes mellitus (NIDDM) model. Twenty male diabetic and 20 male nondiabetic rats were each divided into two groups: treated-DM, untreated-DM, treated-nonDM, and untreated-nonDM. TG (0.2%) was mixed in chow in the treated groups. From age 5 to 15 weeks, fast blood glucose and insulin were monitored. At 15 weeks, oral glucose tolerance test results, aortic wall histopathology, and collagen content were studied, and intravascular ultrasound images and aortic pressure were recorded. Aortic diameter was measured during the cardiac cycle, and the stiffness parameter beta was calculated. Blood glucose (mg/dl) 2 h after loading in treated-DM (139+/-20) was normalized (untreated-DM, 188+/-27; p<0.05). Insulin concentration (ng/ml) in treated-DM (3.2+/-0.4) was lower than that in untreated-DM (8.1+/-1.5; p<0.01). At 15 weeks, beta in untreated-DM (2.4+/-0.8) was larger than those in untreated-nonDM (1.5+/-0.4; p<0.0001) and in treated-DM (1.9+/-0.4, p = 0.0081). Aortic wall collagen (mg/g dry weight) increased in untreated-DM (32.8+/-3.3) as compared with treated-DM (28.1+/-3.8; p = 0.048). Histomorphometry showed decreased medial area (mm2) in treated-DM (0.55+/-0.05) compared with untreated-DM (0.78+/-0.12; p<0.0001). This study suggests that TG may prevent metabolic abnormalities and the deterioration of aortic distensibility at an early prediabetic stage.

Alteration in aortic wall stiffness and accumulation of collagen during the prediabetic stage of type II diabetes mellitus in rats

Aortic damage during the prediabetic stage of diabetes mellitus (DM) was investigated in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, as an animal model of type II DM. In 30 OLETF and 30 nonDM rats, an oral glucose tolerance test was performed at 10, 20 and 30 weeks of age. At 15 and 30 weeks, intravascular ultrasound images and aortic pressure were recorded and the stiffness parameter beta was calculated. The aortic walls were excised at 5, 15 and 30 weeks for histopathology and the measurement of hydroxyproline. At 10 weeks, blood glucose (mg/dl) and insulin concentrations (ng/ml) of the OLETF rats (2h; 168+/-30 and 0.82+/-0.15) were significantly high (nonDM: 118+/-15; p = 0.02 and 0.16+/-0.64; p = 0.003). At the prediabetic stage (15 weeks), beta in the OLETF rats (2.5+/-0.9) was larger than in nonDM rats (1.4+/-0.4; p = 0.0006), and the collagen (hydroxyproline) content/dry weight (mg/g) of the aortic wall was significantly higher in OLETF (33.5+/-3.1) than in nonDM rats (28.7+/-3.5; p<.05). Histopathological examination showed that from 15 weeks of age the medial wall thickness increased gradually. In the prediabetic stage, collagen accumulation may contribute to impairment of aortic wall stiffness in the OLETF rats, which would accelerate the aging process in the aortic wall.

Induced hypertension treatment to improve cerebral ischemic injury after transient forebrain ischemia

The effect of induced hypertension treatment on cerebral ischemia is still controversial. We investigated the preferred blood pressure manipulation level and pressor agent required to reduce cerebral ischemic injury following transient forebrain ischemia induced by bilateral occlusion of the common carotid arteries in anesthetized gerbils. Following 60-min cerebral ischemia, we evaluated the preferred blood pressure manipulation level and pressor agent required to treat cerebral ischemic injury after reperfusion by examining the effects of different levels of mean arterial blood pressure (MABP), increased with phenylephrine or angiotensin II or decreased by blood withdrawal, on cerebral blood flow (CBF), survival ratio, cerebral edema, and brain energy metabolism following transient forebrain ischemia in gerbils. Mild phenylephrine-induced hypertension treatment (21+/-4 mmHg) during post-cerebral ischemia-reperfusion improved the survival ratio and reduced cerebral edema, which was also associated with an increase in local CBF and a recovery of brain energy metabolism. However, intense phenylephrine-induced hypertension, angiotensin II-induced hypertension, or hypotension worsen the survival rate and produced extra cerebral edema, that were also associated with deterioration of brain energy metabolism. These results demonstrate that a mild induced hypertension with phenylephrine (21+/-4 mmHg above the baseline level) results in reduction of the cerebral edema and improves the survival ratio and brain energy metabolism. Furthermore, angiotensin II may have neurotoxic effect to use as the pressor agent for induced hypertension after cerebral ischemia.

Pancreatic invasion as the prognostic indicator of duodenal adenocarcinoma treated by pancreatoduodenectomy plus extended lymphadenectomy

Pancreatoduodenectomy has become the standard procedure in resection of the duodenal adenocarcinoma, and some adjuvant therapies can be added to obtain further improvement in postoperative outcome. However, for patient selection, it is necessary to have a predictive indicator showing, if possible before laparotomy, which instances are noncurable by surgery alone or need adjuvant therapies.

METHODS

A retrospective analysis was made for 24 consecutive patients whose duodenal adenocarcinoma were treated by pancreatoduodenectomy plus a wide range of lymphadenectomies without any adjuvant therapies at Osaka Medical Center for Cancer and Cardiovascular Diseases. Patient survival rates were related to macroscopic and microscopic findings and to findings obtained by preoperative imaging techniques.

RESULTS

The overall survival rate was 69% at 3 years and 57% at 5 years; locoregional recurrence was the primary cause of death. Although the 5-year survival rate was 44% in patients with nodal involvement and 76% in those without, this difference did not reach statistical significance (P = .079). Instead, invasion into the pancreatic parenchyma at a macroscopic level was the most significant prognostic factor; the 5-year survival rate was 78% in the 16 patients without and 16% in the 8 patients with pancreatic invasion (P = .0047). Invasion into the pancreas correlated well with the angiographic findings; the 5-year survival rate was 25% in patients whose angiograms delineated the pancreatic invasion and 83% in patients whose angiograms did not (P = .0084).

CONCLUSION

When duodenal adenocarcinoma was treated by pancreatoduodenectomy plus a wide range of lymphadenectomy, pancreatic invasion at a macroscopic level was most associated with patient survival. Pancreatic invasion was well delineated by the preoperative angiogram, which would be helpful in patient selection.

[A measure to continue intra-arterial infusion chemotherapy long-term for locally advanced pancreatic cancer]

For locally advanced non-resectable cancer of the pancreas, we have routinely performed intra-arterial chemotherapy: Each catheter is placed in the splenic artery and gastroduodenal artery during laparotomy, and a mixture of Methotrexate and Angiotensin-II is infused within 30 minutes. This treatment is repeated weekly at our outpatient clinic as long as possible. However, obstruction of the catheter or corresponding artery is the major cause of interruption of treatment. The present paper reports a case in which intra-arterial chemotherapy was possible by repeated catheterization for the catheter obstruction. A 54-year-old woman with non-resectable pancreatic cancer underwent catheter placement during laparotomy, but they became occluded one month later. Another catheter was placed into the common hepatic artery by the Seldinger method. After this catheter was occluded again, another catheter was placed into the inferior pancreaticoduodenal artery via the superior mesenteric artery by the Seldinger method. By repeating this catheter placement, we succeeded in continuing the intra-arterial chemotherapy, and the patient has remained alive (30 postoperative months) without losing her quality of life.

Interferon therapy in LKM-1 positive patients with chronic hepatitis C: follow-up by a quantitative radioligand assay for CYP2D6 antibody detection

BACKGROUND/AIMS

Liver/kidney microsomal type 1 (LKM-1) antibodies described by indirect immunofluorescence using frozen sections of kidney, stomach and rat liver define a group of patients with type 2 autoimmune hepatitis. Sera react with a non-glycosylated 50-kD protein of the endoplasmic reticulum, which was recently identified as cytochrome P4502D6 (CYP2D6). LKM-1 antibodies may also be associated with hepatitis C virus infection (HCV+/LKM-1+). For this subset of patients, the choice of steroids or interferon alpha therapy may be difficult because of the association of hepatitis C virus infection and autoimmune manifestations. Recently we developed a quantitative immunoprecipitation radioligand assay using 35S-methionine-labeled CYP2D6 protein produced by in vitro transcription and translation reaction. This method detects antibodies against linear and conformational epitopes in both AIH-2 and HCV+/LKM-1+ patients. The aim of this study was to analyze the time-course of HCV+/LKM-1+ patients, applying our radioligand assay over a long follow-up.

METHODS

We studied five patients who were positive for CYP2D6 antibodies from among 235 chronic hepatitis C virus hepatitis patients (2.1%) treated with interferon alpha for a minimal follow-up of 2 years. We analyzed LKM-1 antibody titer sequentially by radioligand assay, HCV RNA titer and alanine aminotransferase activity in these patients.

RESULTS

We found no aggravation of liver disease in this group of patients. Three of these patients showed a sustained biochemical and virological response after interferon. Two others responded partially to interferon therapy. Alanine aminotransferase levels and HCV-RNA decreased during interferon therapy in responder patients. CYP2D6 antibodies did not change in three responder patients during follow-up. One responder patient decreased CYP2D6 antibody level by radioligand assay, but indirect immunofluorescence titers showed a similar pattern. One partial responder patient decreased CYP2D6 antibody level but was negative by indirect immunofluorescence.

CONCLUSIONS

Our results show that patients with hepatitis C virus who are positive for CYP2D6 antibodies may be treated with interferon, and respond in the same way as CYP2D6 antibody negative patients. Radioligand assay could be helpful for monitoring HCV+/LKM-1+ patients receiving interferon therapy.

Spiral CT during pharmacoangiography with angiotensin II in patients with pancreatic disease. Technique and diagnostic efficacy

PURPOSE

To compare the diagnostic efficacy of pancreatic pharmacoangiographic CT using angiotensin II with conventional angiographic CT.

MATERIAL AND METHODS

Eighteen patients with space-occupying pancreatic disease were examined in this study. Pharmacoangiographic CT was performed with a 1-3 micrograms/6-ml solution of angiotensin II injected through a catheter into the celiac artery during spiral CT.

RESULTS

In 17 of the 18 (94%) patients, the area of pancreatic parenchymal enhancement was the same or larger at pharmacoangiographic CT than at conventional angiographic CT. The attenuation value of the pancreatic parenchyma was significantly increased at pharmacoangiographic CT (p = 0.0010). Although the attenuation value of tumors was also increased on images obtained after the injection of angiotensin II, the tumor-to-pancreas contrast was significantly greater at pharmacoangiographic CT (p = 0.0479). The mean differences in attenuation between tumor and pancreas at angiographic CT with and without angiotensin II were respectively 182 HU and 115 HU.

CONCLUSION

Pharmacoangiographic CT with angiotensin II proved superior to conventional angiographic CT in the diagnosis of pancreatic disease. We therefore recommend it as a supplementary technique at the angiographic examination of patients with suspected pancreatic tumor.

Double phase CT arteriography of the whole liver in the evaluation of hepatic tumors

PURPOSE

Our goal was to evaluate the contribution of double phase CT arteriography (CTA) of the whole liver to differentiate hepatic tumors from false-positive areas on CT during arterial portography (CTAP).

METHODS

In 38 candidates for surgical resection of hepatic tumors, both CTAP and double phase CTA were performed. A total of 68 perfusion defects were identified at CTAP. Of 68 perfusion defects, 47 were found to represent hepatic tumors [hepatocellular carcinoma (HCC), n = 31; hepatic metastasis, n = 13; cholangiocarcinoma n = 2; focal nodular hyperplasia, n = 1]. The other 21 perfusion defects were defined as perfusion abnormalities in which focal hepatic masses had not been identified at surgery or pathologic analysis. The phase one CTA scanning started 12 s after the beginning of the injection of contrast material, and the phase two CTA scanning started 20 s after the end of the phase one CTA, with 60 ml of contrast agent (150 mg I/ml) injected at a rate of 2 ml/s.

RESULTS

On phase one CTA, only 1 lesion in 31 HCCs showed rim enhancement and 26 HCCs (84%) had rim enhancement on phase two CTA. Twelve lesions (80%) of the hepatic metastases and cholangiocarcinomas had rim enhancement on phase one CTA and 11 lesions (73%) showed rim enhancement on phase two CTA. Twenty-one perfusion abnormalities on CTAP did not show rim enhancement on either phase one or phase two CTA.

CONCLUSION

Double phase CT arteriography of the whole liver was useful to differentiate hepatic tumors from perfusion abnormalities on CTAP.

[Unruptured intracranial aneurysms: evaluation with high-resolution MR angiography with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE)]

Forty-one patients with suspected intracranial aneurysms were evaluated by conventional three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) or high-resolution 3D TOF MRA with magnetization transfer contrast (MTC) and tilted optimized nonsaturating excitation (TONE). Correlative study was done with conventional angiography in all patients. 3D TOF MRA detected 30 of 36 aneurysms depicted at conventional angiography. The overall rate of sensitivity for the detection of aneurysms was 83%. Unruptured aneurysms were unlikely to occur in the anterior communicating artery (3%), but were frequently found at the bifurcation of the middle cerebral artery (33%). Conventional MRA showed 7 of 9 aneurysms demonstrated at catheter angiography. The rate of sensitivity of conventional MRA for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 0% and 100%, respectively. High resolution MRA with MTC and TONE demonstrated 23 of 27 aneurysms detected by catheter angiography. Sensitivities of high resolution MRA with MTC and TONE for aneurysms smaller than 5 mm and greater than or equal to 5 mm were 71% and 100%, respectively. Our results indicate that high-resolution 3D TOF MRA with MTC and TONE can provide precise, accurate depiction of intracranial aneurysms larger than or equal to 5 mm.

Nimodipine improves brain energy metabolism and blood rheology during ischemia and reperfusion in the gerbil brain

Whether nimodipine improves cerebral blood flow (CBF) and metabolism in cerebral ischemia remains a controversial issue. We investigated the effect of nimodipine on CBF, brain energy metabolism, using a laser-Doppler flowmeter and in vivo 31phosphorus nuclear magnetic resonance (31P NMR) spectroscopy, and blood rheology during forebrain ischemia and reperfusion in gerbils. Eighty-three adult gerbils received nimodipine (1 micrograms/kg/min), or an equal volume of the vehicle, or saline, over 60 min prior to a transient forebrain ischemia for 60 min. We measured sequential changes in phosphocreatine (PCr) / inorganic phosphate (Pi) ratio, beta-ATP/Pi ratio, and intracellular pH (pHi) during ischemia and reperfusion by 31P NMR spectroscopy, and the measurement of whole blood viscosity (WBV) at 60 min after reperfusion. CBF was measured continuously throughout the study by a laser-Doppler flowmeter. During forebrain ischemia, PCr/Pi and beta-ATP/Pi ratios were higher significantly in the nimodipine-treated group (p < 0.05 and 0.01) than in the vehicle- or saline-treated groups. During reperfusion, PCr/Pi and beta-ATP/Pi ratios recovered significantly only in the nimodipine-treated group (p < 0.05 and 0.01). The WBV at high shear rate (562.5 s-1) lowered significantly in the nimodipine-treated group (p < 0.05) compared with the vehicle- or saline-treated group. CBF was higher significantly only during administration of nimodipine in the nimodipine-treated group (p < 0.01) than other groups. Nimodipine improved brain energy metabolism and blood rheology during forebrain ischemia and reperfusion in the gerbil brain.

Duration threshold of induced hypertension on cerebral blood flow, energy metabolism, and edema after transient forebrain ischemia in gerbils

We have investigated whether there is a duration threshold for the effects of phenylephrine-induced hypertension on CBF, brain energy metabolism, and cerebral parenchymal specific gravity (SG) following transient forebrain ischemia in gerbils. Sixty gerbils were randomly assigned to one of the four treatment groups: one control group and three groups subjected to an increase of 25 mm Hg in MABP induced by treatment, 30 min after reperfusion, with phenylephrine for 15 min, 30 min, or 60 min. The local CBF was measured continuously, and the SG was evaluated 120 min after reperfusion. Sequential changes in brain energy metabolism, as shown by the ratio of phosphocreatine to inorganic phosphate (Pi), the beta-ATP/Pi ratio, and intracellular pH, were also measured. The 15-min induced hypertension regimen was most suited to the recovery of brain energy metabolism, which was associated with an increase in local CBF and a decrease in cerebral edema. These results demonstrate that a suitable duration can be chosen to optimize the beneficial effects of phenylephrine-induced hypertension on ischemic brain injury following transient forebrain ischemia.

[Hepatic resection with "wrapping therapy" for advanced hepatocellular carcinoma uncontrolled by arterial embolization]

We report a 70-year-old male patient who had successful hepatic resection with "Wrapping therapy" for advanced hepatocellular carcinoma (HCC) uncontrolled by arterial embolization. His laboratory tests were as follows: Alb: 4.7 (g/dl), T. Bil:0.9 (mg/dl), ICG R15:26.8 (%), PT: > 100%, AFP:33 (ng/ml), HCV-Ab:(-), HBs-Ag:(-). Hepatic angiogram showed a 20 cm sized tumor in the left lobe and many large and small tumors in the right lobe. He received chemoembolization (TAE) five times during seven months. At the time of the fifth hepatic angiogram, TAE was assessed as ineffective because of the resulting collateral feeding arteries. Thus, he underwent left lobectomy, partial resection of the right lobe, and partial "Wrapping therapy" for the regions including foci supplied with parasitic branch. Afterwards, he had TAE two times. One year and five months after the procedure, he is still alive without signs of recurrence.