Prognostic value of machine learning for acute heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

At onset of acute heart failure (AHF), various clinical fundamental parameters including vital sign, laboratory data, or initial treatment were investigated, and we can roughly estimate the prognosis. However, machine learning method for prediction of the prognosis was not studied.

Purpose

To elucidate prognostic value of machine learning for AHF comparing conventional statistical model.

Methods

We enrolled consecutive 300 patients with AHF (79.5 ± 12.1 years, 158 Males). Patients with acute coronary syndrome, mechanical circulatory support cases, and cardio-pulmonary arrest cases were excluded. The patients were randomly divided into 80% (240 cases) and 20% (60 cases), and the former was used as train data, and the latter as validation data. Objective variable was set as cardiac death in one year. First, logistic regression analysis with Akaike’s information criterion (AIC) was performed, and extracted predictive parameters. The predictive model for the cardiac prognosis was constructed by cut-off value of ROC curve analysis of propensity score was calculated. Next, machine learning (random forest method and deep learning) to build predictive model was performed with the predictors. Finally, accuracy of each predictive model was compared.

Results

Thirty cases showed cardiac death in one year. Logistic regression with AIC extracted 8  predictors, and the cut off-value of propensity score with the 6 parameters was 0.110. The accuracy was 0.714 and area under ROC (AUROC) was 0.836. Conversely, random forest method demonstrated the accuracy as 0.927, AUROC 0.860. On deep learning, the accuracy was 0.937 and AUROC 0.901. 

The top 4 high feature importance of random forest were Cl/red blood cell count/pH/Anion Gap. However, accuracy of those predictors was lower than that of machine learning.

Conclusion

Machine learning was a powerful tool to predict cardiac prognosis of AHF, comparing with conventional statistical model. Abstract Figure. Statistical model

Diagnostic performance of deep learning on 12-leads electrocardiography for recurrence after pulmonary vein isolation in patients with persistent atrial fibrillation

Background

Several patients with persistent atrial fibrillation (per-AF) suffer from recurrence after pulmonary vein isolation (PVI). Various methods to predict the recurrence were tried, but deep learning on 12-leads electrocardiography (ECG) after PVI was not studied.

Purpose

To elucidate diagnostic performance of deep learning on 12-leads ECG after PVI in patients with per-AF

Methods

We enrolled consecutive 109 patients with per-AF who underwent PVI (68.8±10.0 years, 83 males) excluding failure cases. We defined recurrence in 3–12 months after PVI. From the ECG just after PVI, five beats of each lead were sampled separately. Deep learning (convolutional neural network on bitmap ECG image) was performed by transfer learning of Inception-Resnet-V2 model. Gradient weighted class activation color mapping (GradCam) was performed to detect convolutional importance in the lead.

Results

Thirty-six patients showed recurrence in the period. Lead II (accuracy 0.701), aVR (0.690) were the top 2 leads of prediction, which showed larger accuracy than statistical accuracies of Non PV foci = SVC (accuracy = 0.541) and left atrial diameter >50mm (0.596). In lead II, GradCam spotlighted strong convolution of latter half of P wave in recurrent case, and former half of P wave and T wave in no-recurrent case.

Conclusions

Deep learning on ECG was a powerful tool to predict recurrence of per-AF after PVI.

Funding Acknowledgement

Type of funding sources: None. Results of deep learningResults of GradCam

Prediction for cardiac prognosis in patients with congestive heart failure by machine learning on dual-isotope myocardial semiconductor SPECT

Background

Dual-isotope (low doze 201TlCl and 123I-β-methyl-P-iodophenyl-pentadecanoic acid (BMIPP)) single photon emission computed tomography (SPECT) is utilized to estimate myocardial damage in patients with congestive heart failure (CHF). However, predictive model construction on the SPECT for cardiac death by machine learning was not studied.

Purpose

To elucidate predictive value of machine learning model on dual-isotope SPECT for CHF.

Methods

We enrolled consecutive 310 patients who admitted with CHF (77.1±3.1 years, 164 males). After initial treatment, they underwent electrocardiography gated SPECT and observed in median 507 days [IQR: 165, 1032]. Multivariate Cox regression analysis for cardiac death was performed, and predictive model was constructed by ROC curve analysis and machine learning (Random Forest and Deep Learning). The accuracies (= [True positive + True negative] / Total) of the prediction models were compared with ROC curve model.

Results

Thirty-six patients fell into cardiac death. Cox analysis showed Age, left ventricular ejection fraction (LVEF), summed rest score (SRS) of BMIPP, and mismatch score were significant predictors (Hazard ratio: 1.068, 0.970, 1.032, 1.092, P value: <0.001, 0.014, 0.002, <0.001, respectively). ROC curve analysis of them revealed the accuracy of the cut-off value was 0.479–0.773. Conversely, machine learning model demonstrated higher accuracy for cardiac death (Random Forest: 0.895, Deep Learning: 0.935). The top 4 feature importance of the random forest were LVEF (0.299), SRS BMIPP (0.263), Age (0.262), and mismatch score (0.160).

Conclusion

Machine learning model on SPECT was superior to conventional statistic model for predicting cardiac death in patients with CHF.

Funding Acknowledgement

Type of funding source: None

The comparison of the chronic-phase vascular healing between bioabsorbable and durable polymer drug eluting stent by using optical coherence tomography

Background

Bioabsorbable polymer drug eluting stents (BP-DESs) were designed to reduce a vascular inflammatory reaction compared to durable polymer drug eluting stents (DP-DESs). However, few studies have compared vascular responses to BP-DESs and DP-DESs.

Methods

We enrolled 88 consecutive patients with single culprit coronary artery lesions (31 lesions with acute coronary syndrome) undergoing a single stent-implantation. BP-DESs and DP-DESs were implanted in 50 (57%) and 38 patients (43%), respectively. All lesions underwent optical coherence tomography examination at chronic phase and intrastent OCT findings at the follow-up were evaluated in every 1-mm cross-sections (CSs).

Results

A total of 1887 CSs (BP-DES: 1096, DP-DES: 791) were analyzed. The median period of follow-up OCT was 293 (250–374) days. There were no differences in the patient, lesion, and initial clinical presentation of acute coronary syndrome (ACS). BP-DESs had significantly higher percent neointimal hyperplasia area, defined as neointimal hyperplasia area divided by stent area x 100 (18.4±9.0% vs. 16.1±9.9%, p<0.001), fewer malapposed struts (1.7% vs. 3.9%, p=0.005), fewer uncovered struts (3.6% vs. 5.8%, p=0.02) but higher frequency of superficial low intensity neointima (LIN) (7.7% vs. 3.4%, p<0.001). Multivariate logistic analysis showed that BP-DES (OR: 2.5, 95% CI: 1.49–4.08, p<0.001) and the initial clinical presentation of ACS (OR: 2.31, 95% CI: 1.47–3.62, p<0.001) are independent predictive factors for LIN.

Conclusion

BP-DESs showed homogenous neointimal growth and complete stent coverage quantitatively. Meanwhile, the significant relationships of BP-DES with LIN may suggest that the neointimal quality remains immature in BP-DESs in this period.

Funding Acknowledgement

Type of funding source: None

Optical coherence tomography findings in healed vulnerable plaques in patients with coronary artery disease

Background

Histopathological analysis or intracoronary image assessment of healed plaques (HPs) has been reported both in acute coronary syndrome (ACS) and stable angina pectoris (SAP) patients. However, background characteristics or lesion morphologies of HPs could not be fully clarified and their differences according to the clinical status remain undetermined.

Purpose

We sought to investigate the clinical and morphological characteristics and compare their differences among ACS and SAP patients in order to clarify the clinical significance in HPs lesions.

Methods

We enrolled consecutive 201 patients with 213 native coronary artery lesions (139 lesions with SAP, 42 ST elevation-ACS (STE-ACS) and 32 non-ST elevation ACS (NSTE-ACS) undergoing pre-intervention optical coherence tomography (OCT). HPs was defined as layered phenotype on OCT. Clinical and angiography characteristics and lesion morphologies on OCT were assessed.

Results

HPs were observed in 110 lesions (51.6%) and their prevalence were not different according to the clinical status (SAP:55.1%, STE-ACS:38.1%, NSTE-ACS:56.3%, p=0.14). Lesions with HPs had higher frequencies of angiography-eccentric lesions (62.7% vs. 35.9%, p<0.001) and OCT-macrophages (65.5% vs. 43.1%, p<0.001), and greater OCT-lumen area stenosis (%-AS) (77.1±10.2% vs. 73.6±10.6%, p=0.01) than those without HPs. Of lesions with HPs, OCT-thin-cap fibroatheroma (SAP 14.4%, STE-AC43.8%, NSTE-ACS 16.7%, p=0.03), plaque rupture (5.3%; 37.5%; 11.1%, p<0.001) and thrombus (6.6%, 75.0%, 22.2%, p=0.007) were more frequently observed in STE-ACS than in SAP patients, whereas OCT-microvessels were more frequent in SAP than in ACS patients (19.7%, 0.0%, 0.0%, p=0.02). Other OCT findings such as macrophages, cholesterol crystal, multiple layered phenotype, and %-AS were not significantly different according to the clinical status. Multivariate logistic regression analysis identified the angiography-eccentric lesions (odds ratio (OR): 2.97, 95% confidence intervals (CI): 1.68–5.25, p<0.001) and OCT macrophages (OR 2.41, 95% CI 1.36–4.27, p=0.003) as independent related factors for the existence of HPs.

Conclusions

The present study showed that HPs lesions had eccentric and large plaque burden, and persistent plaque inflammations regardless of clinical status, which might lead to future coronary events.

Funding Acknowledgement

Type of funding source: None

Optical coherence tomography and coronary angioscopy assessment of healed vulnerable plaque components in patients with coronary artery lesions undergoing elective percutaneous coronary intervention

Background

Many vulnerable plaques would progress without clinical events and might result in healed plaques (HPs). Histopathological or intracoronary image assessment of HPs has been reported. However, the morphological characteristics of HPs remain unclear yet.

Purpose

We sought to assess the healed vulnerable plaque components in patients with coronary artery lesions using optical coherence tomography (OCT) and coronary angioscopy (CAS).

Methods

We enrolled 47 patients with 50 native coronary artery lesions with angiographical severe stenosis (>90% diameter-stenosis) and without severe calcification (36 lesions with stable angina pectoris (SAP) and 14 acute coronary syndrome (ACS)) undergoing pre-intervention OCT and CAS. HPs was defined as layered phenotype on OCT. Lesion morphologies and plaque characteristics in lesions with HPs were assessed using OCT and CAS images.

Results

HPs were observed in 27 lesions (54.0%) and their prevalence were similar among each clinical status (SAP 52.8%, ACS 57.1%, p=1.00). Lesions with HPs had higher prevalence of OCT-macrophage (88.0% vs. 52.0%, p=0.01), CAS-red thrombus (88.8% vs. 52.2%, p=0.004) and CAS-low grade-yellow plaque (grade 1) (55.6% vs. 21.7%, p=0.02) than those without. SAP lesions with HPs had higher prevalence of CAS-yellow plaque (35.3% vs. 5.9%, p=0.09) and OCT-thin-cap fibroatheroma (42.1% vs. 5.9%, p=0.04) than SAP without HPs. ACS lesions with HPs had less CAS-red thrombus (0.0% vs. 50.0%, p=0.03) and OCT-plaque rupture (12.5% vs. 66.7%, p=0.04) than ACS without HPs. Multivariate logistic regression analysis revealed that OCT-macrophages (odds ratio (OR): 6.65, 95%-confidence intervals: 1.07–41.5, p=0.043), CAS-red thrombus (OR 8.77, 95% CI 1.33–57.8, p=0.02), and low grade-yellow plaque (OR 13.05, 95% CI 1.97–86.5, p=0.008) were independently related with the existence of HPs lesions. Combination of these 3 factors showed a high predictive value of OCT-HPs lesions (90.9%).

Conclusions

HPs lesions showed the lower lesion vulnerability than common ACS lesions but had more intraplaque inflammatory condition compared with common SAP lesions. Combined CAS and OCT examination might be useful to clarify the plaque components of HPs lesions in vivo, leading to help us understand the clinical significance of HPs.

Funding Acknowledgement

Type of funding source: None

Differences of ST level at J-point on 12-lead electrocardiography can distinguish takotsubo syndrome and acute anterior myocardial infarction

Background

Qualitative difference of ST elevation/depression on 12-leads electrocardiography (ECG) at onset was reported in patients with Takotsubo syndrome (TTS) and acute anterior myocardial infarction (ant AMI). However, quantitative difference of those was not elucidated.

Purpose

To investigate differences of ST level at J point on ECG between TTS and ant AMI by automated calculating system.

Methods

We firstly enrolled consecutive 40 patients of TTS, and among 500 ant AMI patients, one to two random matching was done by their age and gender. Finally, 40+80 patients (74.5±11.2 years, 87 females) were enrolled. ECG at onset of both group was measured by automated system (ECAPs12c: Nihon-Koden).

Results

ST level of TTS at J-point in I/II/V4–6 lead was significantly elevated comparing to that of ant AMI. Conversely, Conversely, significant ST depression in aVR and no ST elevation in V1 of TTS was observed in TTS. Logistic regression analysis revealed that ST elevation in I lead and no ST elevation in V1 lead showed high odds ratio and low P value.

Conclusion

Automated measured ST level at J-point was a powerful tool to distinguish TTS and ant AMI at onset.

Funding Acknowledgement

Type of funding source: None

Diagnostic performance of 18-leads electrocardiography to distinguish takotsubo syndrome and acute anterior myocardial infarction

Background

Electrocardiographic (ECG) features on acute phase of Takotsubo syndrome (TTS) is recognized to mimic that of acute anterior myocardial infarction (ant AMI). However, the difference of synthesized 18-leads ECG of both diseases was not elucidated.

Purpose

To elucidate diagnostic performance of 18-leads ECG to distinguish TTS and acute anterior AMI.

Methods

We firstly enrolled consecutive 40 patients of TTS, and among 500 ant AMI patients, one to two matching was done by their age and gender. Finally, 40+80 patients (74.5±11.2 years, 87 females) were enrolled, and ECG at onset of both group was estimated. Because of multicollinearity, all significant differences were compared by machine learning (Random Forest method).

Results

Prevalence of Q wave had no difference. Conversely, ST depression in TTS and ST elevation in ant AMI were significant differences in V7–9 leads. T-wave polarity of V3R-V9 leads were significantly different (flat T-wave in TTS and positive in ant AMI). Machine learning revealed T wave polarity in V7 lead had the highest feature importance.

Conclusion

18-leads ECG at onset had powerful diagnostic performance to distinguish the two diseases.

Funding Acknowledgement

Type of funding source: None

P4386Prognostic value of pressure-strain curve analysis by echocardiography for cardiac death in patients with congestive heart failure

Background

Pressure-strain curve analysis (PS-curve) is novel method of echocardiographic evaluation for left ventricular (LV) systolic myocardial work including the effect of blood pressure. However, the prognostic value of PS-curve for prospective cardiac death in patients with congestive heart failure (CHF).

Purpose

To elucidate the prognostic value of PS-curve analysis for cardiac death in patients with CHF.

Methods

We enrolled 63 consecutive sinus-rhythm patients with CHF admission who were evaluated by PS-curve analysis before discharge (76.0±13.3 years, 39 males). Endpoint was set as all cardiac death.

Results

Observation period was median 327 days [25%: 91, 75%: 656 days], and the longest period was 1004 days. Five patients died for cardiac causes. Multivariate Cox regression analysis (stepwise regression) revealed diastolic blood pressure (BP) and global constructive work (GCW) were independent predictors (Hazard ratio: 0.854, 0.996, P value: 0.016, 0.019, respectively). ROC curve analysis demonstrated GCW ≤601 had high diagnostic performance for cardiac death (specificity 0.891, sensitivity 0.800, area under ROC 0.824). Kaplan-Meyer curve analysis indicated the group with GCW ≤601 was worse cardiac prognosis (Logrank P<0.001).

Cox Hazard Regression Analysis Univariate Multivariate (stepwise regression) Hazard Ratio 95% CI P Hazard Ratio 95% CI P BP systole (mmHg) 0.915 0.85–0.99 0.026 BP diastole (mmHg) 0.915 0.84–0.99 0.043 0.854 0.75–0.97 0.016 LVDd (mm) 1.064 1.01–1.12 0.025 NA LVDs (mm) 1.066 1.01–1.12 0.016 LVEF (%) 0.963 0.91–1.02 0.221 LAD (mm) 1.197 1.06–1.36 0.005 GWE 0.937 0.88–0.99 0.041 GWI 0.998 0.99–0.99 0.041 NA GCW 0.998 0.99–0.99 0.037 0.996 0.99–0.99 0.019 GWW 0.996 0.98–1.01 0.502 Considering multicollinearity, we excluded GWI and LVDd (correlation coefficient: GWI and GCW = 0.979, LVDd and LVDs = 0.942).

Conclusion

Pressure-strain curve analysis had powerful predictive value for cardiac death in patients with CHF.

P5643Simple 12-leads electrocardiography can predict cardiac death in patients with complete left bundle branch block

Background

Patients with complete left bundle branch block (CLBBB) generally fall in two categories: CLBBB with good prognosis and poor prognosis. However, a simple electrocardiography (ECG) was considered impossible to predict the two categories.

Purpose

To elucidate the possibility of 12-leads ECG for predicting cardiac prognosis in patients with CLBBB

Methods

To estimate myocardial damage and left ventricular function, the ECG was performed with semiconductor SPECT simultaneously. Among consecutive 5864 patients who underwent ECG gated SPECT, finally 103 sinus-rhythm patients were enrolled. The observed period of them was median 632 days, and primary endpoint was set as cardiac death.

Results

Eight patients fell into cardiac death. Cox univariate analysis showed ventricular activation time (VAT: duration from onset of Q wave to peak of R wave) in V1 lead, T wave amplitude in aVR (aVR T-amp), and multiple fragmented QRS (At least 2 fQRS in LV anterior/inferior/lateral wall), and left ventricular ejection fraction, standard deviation of phase analysis (Phase SD), and summed rest score were significant predictors. After optimization of all significant continuous predictors by ROC curve analysis, all the significant predictors were analyzed by multivariate Cox analysis (stepwise regression). VAT in V1 (Hazard ratio: 4.594, P=0.034), aVR T-amp ≥-85microV (HR: 11.11, P=0.029), and Phase SD≥48.7 (HR6.047, P=0.035) were independent predictors. Kaplan-Meyer curve analysis demonstrated VAT V1≥70 and aVR T amp≥-85 showed the worst prognosis (P=0.008).

Cox Regression after Optimization by ROC Univariate Multivariate (Stepwise regression) HR 95% CI P HR 95% CI P VAT I ≥70 6.861 1.759–26.76 0.006 4.594 1.126–18.75 0.034 T amp in aVR ≥−85 27.34 3.458–216.2 0.002 11.11 1.274–96.85 0.029 Multiple fQRS 3.836 1.081–13.61 0.037 LVEF ≤37% 7.250 1.874–28.04 0.004 SD ≥48.7 17.30 3.671–81.57 <0.001 6.047 1.133–32.28 0.035 SRS≥17 4.178 1.206–14.48 0.024 SD: standard deviation of histogram by phase analysis of SPECT; SRS: summed rest score by myocardial perfusion analysis of SPECT.

Conclusion

Simple 12-leads ECG could predict the prognosis of patients with CLBBB.

[Clinical characterization of blaIMP positive gram-negative rods isolated cases]

We detected the metallo-beta-lactamase gene blaIMP positive strains of the gram-negative rods (GNR) isolated in Oita Medical University Hospital between 1993 and 1999 and studied the clinical characteristics of patients infected or colonized with blaIMP positive GNR. 25 strains (20 Pseudomonas aeruginosa and 5 Serratia marcescens) were detected and most of them were isolated from urinary samples after 1997. In the studies of antimicrobial susceptibility, some strains had sensitivity to aztreonum or imipenem although most of the strains showed multidrug resistance. When blaIMP positive GNR were isolated from patients, these strains were thought to have caused infection in 88% of the patients. About half of the patients were over 65 years old and had malignant diseases. Most of the patients had inserted urinary tract catheters, intratracheal tube or intravernous catheters. It was suggested that the insertion of the catheters were related to infection of blaIMP positive GNRs. Two patients were not treated with any antibiotics before the isolation of blaIMP positive GNRs although more than half of the patients were administered carbapenems and cephems. Most of strains were isolated in the same department and showed the same genotype by pulsed field gel electrophoresis.

Studies of mass infant screening for Wilson disease by urinary ceruloplasmin

We found a 4-year-old boy in the screened cohort, who showed a low ceruloplasmin (CP) in urine (17 ng/mg-creatinine) and in blood (0.6 mg/dl), but his urine copper was in the normal range. Furthermore this child was diagnosed as Wilson disease (WD) by genetic analysis. Although no significant correlation was observed between urine and blood levels of CP, it is conceivable that WD may be accompanied by very low concentration of urine CP.

[Recent knowledge allowing diagnosis and treatment of deep-seated trichosporonosis]

Deep-seated trichosporonosis is a lethal opportunistic infection in immunocompromised patients. For the rapid diagnosis of this condition, we developed a novel nested-PCR assay that detects DNA specific for clinically important strains of Trichosporon in serum of patients with disseminated trichosporonosis. In this assay, two sets of oligonucleotide primers were derived from the sequence of 26 S ribosomal RNA genes of T. asahii. The specific fragment was amplified from T. asahii and T. mucoides but not from other microorganisms. In a retrospective study using serum samples of patients with disseminated trichosporonosis, the specific fragment was detected in 64% (7 of 11). To treat this infection, we studied the efficacy of rhG-CSF alone and in combination with antifungal agents against disseminated trichosporonosis in neutropenic mice. The results suggested that rhG-CSF might be a useful immunomodulator against Trichosporon infections and the therapeutic outcome might be better when used in combination with antifungal agents.

[A case of pulmonary manifestation associated with myelodysplastic syndrome]

A 69-year-old woman with myelodysplastic syndrome (MDS) was admitted to our hospital because of recurrent fever and pulmonary infiltration shadows. On the seventh day of hospitalization, she had an attack of high fever and cough and laboratory tests revealed an elevated leukocyte count and elevated serum C-reactive protein. Chest radiographs showed infiltration shadows in the right middle and lower lung fields. Because a diagnosis of bacterial pneumonia was initially suggested, she was treated with antibiotics. However, the infiltration shadows on the chest radiograph had not improve, so bronchofiberscopy was performed. Analysis of fluid obtained by bronchoalveolar lavage (BAL) showed an increase in the total cell count, predominantly in lymphocytes and neutrophils. A transbronchial biopsy specimen showed infiltration of numerous neutrophils with necrosis under the bronchial epithelium, and edematous septa were infiltrated with numerous neutrophils and lymphocytes. BAL, blood, urine, bone marrow, and sputum cultures were all free of bacteria, mycobacteria and fungi. Interstitial infiltration by numbers of neutrophils associated with MDS was diagnosed and steroid treatment was performed.

[A small cell lung cancer shadow resembling beads on chest radiographs]

We present a case of small cell lung cancer whose shadow resembles bead son chest radiographs. An 81-year-old woman who had been receiving treatment from her doctor for pulmonary emphysema and chronic respiratory failure consulted our department because a small nodular shadow had been detected radiographically in the right lower lung field. The bead-like shadows in the radiographs and tomograms extended from the periphery of the right lower lobe to the pulmonary hilum. This case of small cell lung cancer appeared in chest radiographs to have an unusual shape.

Experimental model of progressive disseminated trichosporonosis in mice with latent trichosporonemia

Trichosporon asahii and Trichosporon mucoides are the most common strains of fungi that cause disseminated trichosporonosis, a severe opportunistic infection in immunocompromised hosts. We have previously established a nested PCR assay using serum samples for detection of both strains. Here we describe a new experimental animal model for investigating the underlying mechanisms of disseminated trichosporonosis. T. asahii (OMU239, a clinical isolate from a patient with acute myelogenous leukemia) and 8-week-old ICR male mice were used in all experiments. A suspension of T. asahii (3 x 10(6) CFU/animal) was injected into the caudal vein of each mouse after immunosuppression with cyclophosphamide (200 mg/kg of body weight/day for 2 days) and prednisolone (30 mg/kg/day for 1 day). Mice were then divided into four subgroups (R0, R1, R2, and R3) based on the time of reimmunosuppression. The latter was performed using the same drugs 1 week (group R1), 2 weeks (group R2), and 3 weeks (group R3) after fungal infection. Reimmunosuppression was not performed in group R0. The 5-week-survival rates of mice after T. asahii infection were 0% for group R1, 50% for group R2, 80% for group R3, and 80% for group R0. There was a significant difference in the survival rates between group R1 and either group R0 or R3 (P < 0.05). Fungal clearance in peripheral blood and various organs of group R1 and R2 was delayed relative to that of group R0 but was similar to the control in group R3 in spite of reimmunosuppression. Our results suggest that the critical period for the development of disseminated trichosporonosis in our model is shorter than 3 weeks after T. asahii infection. We concluded that mice during this critical period were in a state of latent trichosporonemia. Comparison of the survival rates suggests that the nested PCR assay was more useful than blood culture and glucuronoxylomannan antigen assay in the detection of this latent trichosporonemia.

[A case of tuberculous peritonitis diagnosed by ultrasonography-guide peritoneal biopsy]

The diagnosis of tuberculous peritonitis is quite difficult because the symptoms are not specific for the disease and the incidence of occurrence are relatively rare. We report a case of tuberculous peritonitis diagnosed by ultrasonography-guided peritoneal biopsy. A 64-year-old male was admitted to our hospital because of fever, dyspnea and abdominal pain. Laboratory findings revealed an elevated ESR (53 mm/1 hr.) and positive CRP. The tuberculin skin test was negative. The chest radiograph revealed bilateral pleural effusion. Abdominal ultrasonographic examination and computed tomography showed ascitic fluid, thickening of the mesentery and peritoneum, and inflammatory pseudotumor of the omentum. Ascitic fluid was exudate with a high lymphocyte count and elevated ADA (184 IU/l). Microbiological studies with the fluid were negative. Peritoneal biopsy guided by ultrasonography was performed, and the specimens showed central caseous necrosis surrounded by epitheloid cells and acid-fast bacilli were demonstrated. The size of the pseudotumor, pleural effusion and ascites decreased after antituberculous chemotherapy with corticosteroid was given. Diagnosis of tuberculous peritonitis has often been made by laparotomy or laparoscopy. In a case of this kind, percutaneous peritoneal biopsy guided by ultrasonography is safe and useful.

[Primary pulmonary cryptococcosis with endobronchial lesion]

A 19-year old man was admitted to our hospital with fever and productive cough. Chest X-ray films revealed multiple nodular shadows accompanied by a fusing tendency in the right middle field. A diagnosis of bacterial pneumonia was indicated, and the patient was treated with antibiotics. However, because this failed to resolve the nodular shadows, bronchofibroscopy was performed. Examination with a fiberoptic bronchoscope revealed an elevated lesion in the truncus intermedius. Histopathologic examination of a specimen obtained by transbronchial biopsy revealed cryptococcal organisms with the infiltration of monocytes. These findings yielded a diagnosis of pulmonary cryptococcosis with endobronchial lesion. After 6 months of treatment with fluconazole, the multiple nodular shadows disappeared. Comparison of bronchoscopic findings before and after fluconazole treatment clearly demonstrated the efficacy of the therapy.

PCR detection of DNA specific for Trichosporon species in serum of patients with disseminated trichosporonosis

Deep-seated trichosporonosis is a lethal opportunistic infection that disseminates rapidly and widely in immunocompromised patients, and early diagnosis is crucial for the treatment of this infection. We developed a novel nested-PCR assay that detects DNA specific for clinically important strains of Trichosporon in serum samples from patients with disseminated trichosporonosis. In this assay, two sets of oligonucleotide primers were derived from the sequence of 26S rRNA genes of Trichosporon asahii. The specific fragment was amplified from T. asahii and T. mucoides, but not from other microorganisms, including some other basidiomycetous fungi (Cryptococcus, Malassezia, Rhodotorula, and Sporobolomyces). Target DNA was detected by the nested PCR with as little as 5 fg of the extracted DNA of T. asahii. In a study using 11 clinical samples, the specific fragment was detected by the nested PCR in 64% (7 of 11) of sera from patients with histologically diagnosed disseminated trichosporonosis, while glucuronoxylomannan antigen was detected in only 54% (6 of 11) of the samples. Our new nested-PCR assay using serum samples can be performed repeatedly throughout the course of the disease. In addition, not only can it be used for early diagnosis of trichosporonosis, but it may also be beneficial for monitoring its progress or response to therapy.

Comparison of PCR, (1-->3)-beta-D-glucan and galactomannan assays in sera of rats with experimental invasive aspergillosis

We compared PCR, galactomannan detection assay using a latex agglutination test and (1-->3)-beta-D-glucan detection assay in detecting infection in rats experimentally infected with Aspergillus fumigatus. On day 2 after inoculation, (1-->3)-beta-D-glucan and nested PCR were positive for 80%, while galactomannan detection assay was positive for 60%. In addition, the positive result of nested PCR (87.5%) was higher than those of galactomannan detection assay (75%) and (1-->3)-beta-D-glucan (71.4%) on day 3 after inoculation. The sensitivity of nested PCR was superior to those of galactomannan detection assay and (1-->3)-beta-D-glucan detection assay. The three diagnostic tests were compared with histopathological findings, and the sensitivity of three diagnostic tests was correlated with histopathological changes. In addition, the elevated levels of (1-->3)-beta-D-glucan paralleled the development and progression of pulmonary aspergillosis. Our results indicate that a combination of two or three of these tests seems to provide a rapid diagnosis of invasive aspergillosis and assist in the evaluation of the development and severity of invasive aspergillosis.

Evaluation of PCR for detection of DNA specific for Aspergillus species in sera of patients with various forms of pulmonary aspergillosis

Pulmonary aspergillosis is classified into invasive, saprophytic, and allergic forms. In this study, we evaluated the usefulness of PCR for differentiating between different forms of aspergillosis or in monitoring disease activity during treatment by detecting DNA specific for Aspergillus species in the serum. Nested PCR was used to detect Aspergillus DNA in the sera of 30 patients with various forms of pulmonary aspergillosis. The results were compared with those of latex agglutination tests for detecting galactomannan antigen. We also examined the serial changes in the results of nested PCR during and after treatment of a subgroup of patients with invasive pulmonary aspergillosis with amphotericin B. The highest proportion of positive nested PCR results were in patients with invasive aspergillosis (10 of 12; 83%), while patients with pulmonary aspergilloma had the lowest frequency of positive tests (1 of 9; 11%). These results suggested that the sensitivity of the nested PCR depends on the extent of invasion by Aspergillus species. Serial assays showed that the results of nested PCR became negative shortly after commencement of antifungal treatment and that such changes did not correlate with clinical responsiveness to treatment. Our results indicate the potential usefulness of nested PCR with serum samples for the diagnosis of invasive aspergillosis and the detection of a shift in the status of infection from a noninvasive type to invasive aspergillosis. However, the results of the nested PCR did not correlate with the response to antifungal treatment.

[Evaluation of new method for diagnosis of opportunistic fungal infection]

New methods for the possible presence DNA specific for Aspergillus or Trichosporon species were developed. In aspergillus PCR, Aspergillus l8S rRNA encoding gene was amplified from five strains of Aspergillus species by the nested PCR but not from other microorganisms. Results of preliminary investigation of this method demonstrated efficient detections of Aspergillus species in serum samples of rats model of aspergillosis and 29 patients with invasive aspergillosis. In trichosporon PCR, Trichosporon 26S rRNA encoding gene was amplified from two strains of Trichosporon species, and detected by the nested PCR in 64 % of serum samples of patients with trichosporonosis, while glucuronoxylomannan antigen was detected in 55 % of samples. The high sensitivity and specificity of the nested PCR indicate that the assay can provide early diagnosis with sufficient accuracy to be clinically useful for patients with opportunistic fungal infection.

[Clinical study on mechanism of Pneumocystis carinii pneumonia by polymerase chain reaction]

Pneumocystis carinii is a human respiratory pathogen which causes fatal pneumonia in patients under immunosuppressed or immune deficient conditions. Recent work have documented the usefulness of the polymerase chain reaction (PCR) method in the detection of P. carinii from clinical samples. Therefore, we described our experience in using PCR method in the detection of P. carinii from respiratory samples. In our study, bronchial washing or BALF were good for diagnosis of P. carinii pneumonia (PCP) by PCR. However, PCR method in the detection of P. carinii from swab or sputum was too sensitive because small numbers of P. carinii organisms might be insignificant in causing the disease. It might reveal colonization or asymptomatic carrier state in the upper respiratory tract. Therefore, our result suggested that colonization or asymptomatic carrier state in the upper respiratory tract could eventually evolve into PCP. This would also facilitate basic progress in the pathology or epidemiology of P. carinii infection. In addition, an usefulness of prophylactic therapy for PCP was documented by PCR.

[Pulmonary dirofilariasis associated with pleural effusion]

A 61-year-old man was admitted to our hospital because of a long history of productive coughing. A chest roentgenogram and CT scan showed a right-sided pleural effusion. The effusion fluid was blood-stained but showed no cytological evidence of malignancy. Marked eosinophilia was found in blood and in the pleural effusion fluid. Ouchterlony's double-diffusion test done with the patients serum and pleural effusion fluid in agarose showed specific bands toward Dirofilaria immitis antigen, and this specificity was confirmed with an enzyme linked immunosorbent assay inhibition test. The final diagnosis was pulmonary dirofilariasis, and the patient responded to diethylcarbamazine.

[Case report: subcutaneous abscess and thoracic empyema caused by Alcaligenes xylosoxidans]

Alcaligenes xylosoxidans is a glucose-nonfermentative gram-negative rod which usually exists in the environment. This organism while causing pneumonia, sepsis, meningitis and urinary tract infection in the compromised host, rarely causes thoracic empyema. We report a case of thoracic empyema and subcutaneous abscess due to A. xylosoxidans. A 74-year-old male, who had undergone right total pneumonectomy for chronic necrotizing pulmonary aspergillosis a year ago, was admitted to our hospital because of fever. CT scans of the chest revealed a subcutaneous abscess and empyema. Empyema and subcutaneous pus were aspirated. Culture of materials produced A. xylosoxidans. There was no significant change on symptoms and examinations despite therapy with PIPC 4 g/day and thoracic drainage. Finally, surgical treatment was required and the patient was cured.

[Detection of Aspergillus species DNA in serum samples of the patients with non-invasive pulmonary aspergillosis]

We investigated the possible presence of Aspergillus species DNA in serum samples of two patients diagnosed as having non-invasive pulmonary aspergillosis by a nested polymerase chain reaction (PCR) method. The nested PCR results were negative in serum samples of the patients with chronic necrotizing pulmonary aspergillosis and pulmonary aspergilloma. When left pneumothorax happened to the patient with chronic necrotizing pulmonary aspergillosis and bronchial washing was performed to the patient with pulmonary aspergilloma, the nested PCR results turned positive. We consider this method useful for the diagnosis of semi-invasive stage of pulmonary aspergillosis. However, further prospective evaluation with a large clinical sample is required.

[Detection of DNA specific for Aspergillus species in serum samples from two patients with invasive pulmonary aspergillosis]

We investigated the possible presence of DNA specific for Aspergillus species in serum samples of two patients who were strongly suspected for invasive pulmonary aspergillosis (IPA) by a nested polymerase chain reaction (PCR) method. Both patients were diagnosed as having acute myelogenous leukemia and treated with induction chemotherapy. During chemotherapy-induced granulocytopenia, they complained of high fever, and the chest X-rays indicated infiltration shadows in their lungs. They were treated with antibiotics intravenously, but no clinical improvement was observed. As the results of the nested PCR were positive at the acute stage of infection, amphotericin B i.v. and granulocyte colony stimulating factor s.c. administrations were started in both cases. In case 1, the infectious disease improved and the nested PCR results turned negative after treatment. In case 2, in spite of the progression of the disease, the nested PCR results turned negative during treatment. Although we consider this method very useful for the diagnosis of IPA, further prospective evaluation with a large clinical population sample is required.

PCR detection of DNA specific for Aspergillus species in serum of patients with invasive aspergillosis

We investigated the possible presence of DNA specific for Aspergillus species in serum samples of patients with invasive aspergillosis (IA) by the nested PCR method. Fourteen strains of fungi including 5 strains of Aspergillus species and 10 strains of common bacteria were used for examination of specificity and sensitivity of the nested PCR. Two sets of oligonucleotide primers were derived from the sequence of the variable regions V7 to V9 of the 18S rRNA genes of Aspergillus fumigatus. The specific fragment was amplified from five strains of Aspergillus species in the single and nested PCR but not from other microorganisms. Target DNA was detected by the nested PCR with as little as 50 fg of the extracted DNA of A. fumigatus. We investigated the detection of DNA specific for Aspergillus species in serum samples of a murine model of aspergillosis and 20 patients with IA. The specific fragment was detected by the nested PCR in 71% of serum samples of infected mice and 70% of serum samples of patients with IA, while galactomannan antigen was detected in 43 and 60% of samples, respectively. The high sensitivity and specificity of the nested PCR indicate that the assay can provide early diagnosis with sufficient accuracy to be clinically useful for immunocompromised patients with IA.

[Endobronchial actinomycosis]

A 63-year-old man was admitted to our hospital with obstructive pneumonia. The chest X-ray film and computed tomogram showed an infiltrative shadow in the right lower lung field. Examination with a fiberoptic bronchoscope showed a mass in the right basal bronchus. These findings suggested the diagnosis of lung cancer with obstructive pneumonia. Histopathological examination of a specimen obtained by transbronchial biopsy revealed sulfur granules with infiltration of neutrophils, which led to the diagnosis of endobronchial actinomycosis. After three months of treatment with penicillin, the mass disappeared. Comparison of bronchoscopic findings before and after penicillin treatment clearly showed the efficacy of therapy.

[Detection and quantitation of cytomegalovirus DNA in plasma from patients with cytomegalovirus pneumonia]

Detection and semiquantitation of cytomegalovirus (CMV) DNA in plasma from 17 immunocompromised patients with CMV pneumonia diagnosed histopathologically, 15 CMV seropositive patients without CMV pneumonia and 24 CMV-seropositive healthy volunteers were evaluated, using the polymerase chain reaction (PCR). CMV DNA was detected in plasma from all of 17 patients with CMV pneumonia, from 1 of 15 patients without CMV disease, but from none of healthy volunteers. One patient without CMV disease exhibited positive CMV DNA by PCR 2 days before death. Plasma CMV DNA was negative at the time of admission in all patients, however, it became positive 1-28 days (mean, 14 days) before the onset of CMV pneumonia in 16 patients. The amount of viral DNA in plasma were 10(3) - 10(5) copies/ml (mean, 10 (4.0) copies/ml) when first detected by PCR. At the onset of CMV pneumonia, they were 10(4)-10(6)(mean, 10(5.3) copies/ml), and increased with disease progression and decreased with disease improvement because of treatment with antiviral agents. We succeeded in detection of CMV DNA in plasma before the development of CMV pneumonia, and showed the amount of viral DNA reflected the extent of active CMV pneumonia. Thus, PCR amplification of CMV DNA in plasma is a useful tool for early diagnosis and monitoring of immunocompromised patients.

[Microbiological and clinical study of fungemia between 1981 and 1992]

Fungi were isolated from 113 (14.2%) of 789 patients with positive blood cultures at Oita Medical University Hospital between 1981 and 1992. The rates of fungemia increased in recent years, 13.9% (1981-1985), 12.1% (1986-1988) and 16.9% (1989-1992). The isolated fungi were Candida parapsilosis (25.7%), C. albicans (24.8%), C. tropicalis (14.2%), Trichosporon beigelii (10.6%), C. glabrata (8.0%) and so on. The major fungi were T. beigelii and C. glabrata in patients with hematologic malignancies, whereas they were C. albicans and C. parapsilosis in patients with non-hematologic diseases and C. glabrata increased in both groups. Prophylactic or emiric administration of antifungal agents probably influenced the difference of the causative organisms in the two groups.

[A case of pulmonary lymphangiomyomatosis diagnosed by biopsy of retroperitoneal tumor and treated with hormonal therapy]

A 34-year-old woman was admitted to our hospital because of exertional dyspnea and ascites. Chest roentgenogram showed hyperinflation of the lung and diffuse reticular shadows. Abdominal CT showed retroperitoneal tumors. Ascites was considered to be chylous. These findings strongly suggested the diagnosis of pulmonary lymphangiomyomatosis. Under lumbar anesthesia, laparotomy was performed, and the histological finding of the retroperitoneal tumor revealed angiomyoma. Bilateral oophorectomy was performed. Medroxyprogesterone at 15 mg/day was administered postoperatively. In advanced cases of this disease, open lung biopsy or even transbronchial lung biopsy is often avoided because of severe cardiopulmonary dysfunction. However, such cases associated with retroperitoneal tumor, laparotomy is quite useful not only in making the diagnosis but also in the treatment of this disease.

[A case of smoldering adult T-cell leukemia complicated by various pulmonary infections]

A 46-year-old man was admitted to Oita Medical College Hospital on October 16, 1987, because of cough and sputum. Chest X-ray and chest CT films showed diffuse reticulonodular shadow. The specimens obtained by transbronchial lung biopsy revealed cysts of pneumocystis carinii. Abnormal lymphocytes with lobulated nuclei were found 2-7% of peripheral leucocytes. The anti HTLV-I antibody was positive. According to these data, we diagnosed the patient as smoldering adult T cell leukemia with pneumocystis carinii pneumonia. The abnormal shadow on chest X-ray disappeared after SMX-TMP and pentamidine treatment. After about 1 year, he was again admitted for high fever. Chest X-ray showed infiltration with cavity in right upper lobe. Streptococcus pneumoniae was isolated from the sputum. The infiltration shadow on chest X-ray disappeared after antibiotics treatment. However, multiple nodular shadow appeared on the chest X-ray and ATL cell infiltration was found in the specimens of transbronchial lung biopsy. ATL cells in peripheral blood also increased and serum LDH and Calcium levels were markedly high. According to these data, we diagnosed the patient as having a ATL crisis. Although chemotherapy for ATL was started, the ATL, cell infiltration shadow on the chest X-ray enlarged, and bilateral diffuse patchy shadows was appeared on the chest X-ray. He died of respiratory failure on April 26, 1989. Cytomegalovirus pneumonia and ATL cell infiltration were revealed by necropsy.

The projection linkage between the spinal dorsal horn neurons and both the solitary tract and dorsal column nuclei

Electrical stimulation of the solitary tract nucleus (SN) and dorsal column nuclei (DCN) as well as microelectrode recording from the lumbal spinal dorsal horn have been used to find and identify the axonal projection of and the afferent innervation on the spinal neurons of pentobarbital-anesthetized rats. A total of 92 neurons was recorded and identified mainly in laminae III-V of the lumbar spinal dorsal horn. Of them, 38 neurons were activated antidromically from stimulation of both the SN and DCN. The other 54 neurons responded synaptically to both the SN and DCN stimulations. The initial antidromic responses of 8 neurons in the first group were followed by one or more responses synaptically driven from the SN and/or DCN stimulation. Conduction velocities were in the range of A delta fibers, but faster in the antidromic responses and slower in the synaptic responses. These results indicate that (i) some spinal neurons issue branched axons of larger-sized A delta fibers and double project to both the SN and DCN; (ii) some of these double projection neurons receive in turn smaller A delta fiber innervation from the SN and/or DCN; and (iii) some other neurons in the spinal cord are dually innervated by smaller A delta fibers originating from both nuclei.

Physiological identification and property of afferents from the masseter muscle to the caudal part of the trigeminal nucleus in rat

The present study was to identify the physiological properties of the afferent fibers from the masseter muscle to the caudal part of the spinal trigeminal nucleus of rat using a microelectrode technique. When electrical stimulation was applied to the masseter muscle, the evoked potentials were recorded with a shorter latency (the S-response) or a longer latency (the L-response). The threshold current intensity of the S-response was lower than that of the L-response. There were statistical significant differences between the S-response and the L-response in latency and in threshold current intensity. Both the S- and L-responses could follow by stimulation of low frequencies (10 to 30 Hz), indicating that the evoked responses were the component of the secondary neuron activities. On the anatomical and physiological assumption, the conduction velocities of the S- and the L-responses were calculated and they were in the range of that of A-delta fibers. We also observed that both the S- and the L-responses could not follow high frequency stimulation of the masseter muscle. This effect may reflect the phenomenon of fatigue in the finely myelinated fibers or polymodal nociceptors. Thus, the present study suggested the involvement of the afferents from the masseter muscle to the spinal trigeminal nucleus in the transmission and the relay of the masticatory muscle pain.

Suppression of the tail flick reflex by electroacupuncture delivered at the intra- and extrasegmental needling points

Electroacupuncture effects conveyed by A beta afferent nerve impulses from the different dermatomes, the Zusanli and the Hoku, was compared using the tail flick reflex in lightly anesthetized rats. The Zusanli stimulation decreased the EMG activity, but the threshold temperature did not change. These effects were not antagonized by naloxone (1 mg/kg). The Hoku stimulation also produced the suppression of the EMG activity without the increase of the threshold temperature. However, these effects were antagonized by naloxone (1 mg/kg). These results suggest that intrasegmental stimulation presynaptically inhibits the input of the noxious message in the spinal cord through the non-opiate system, while extrasegmental stimulation presynaptically inhibits this input through the opiate system.