Convolutional Neural Network to Stratify the Malignancy Risk of Thyroid Nodules: Diagnostic Performance Compared with the American College of Radiology Thyroid Imaging Reporting and Data System Implemented by Experienced Radiologists

BACKGROUND AND PURPOSE

Comparison of the diagnostic performance for thyroid cancer on ultrasound between a convolutional neural network and visual assessment by radiologists has been inconsistent. Thus, we aimed to evaluate the diagnostic performance of the convolutional neural network compared with the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) for the diagnosis of thyroid cancer using ultrasound images.

MATERIALS AND METHODS

From March 2019 to September 2019, seven hundred sixty thyroid nodules (≥10 mm) in 757 patients were diagnosed as benign or malignant through fine-needle aspiration, core needle biopsy, or an operation. Experienced radiologists assessed the sonographic descriptors of the nodules, and 1 of 5 American College of Radiology TI-RADS categories was assigned. The convolutional neural network provided malignancy risk percentages for nodules based on sonographic images. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated with cutoff values using the Youden index and compared between the convolutional neural network and the American College of Radiology TI-RADS. Areas under the receiver operating characteristic curve were also compared.

RESULTS

Of 760 nodules, 176 (23.2%) were malignant. At an optimal threshold derived from the Youden index, sensitivity and negative predictive values were higher with the convolutional neural network than with the American College of Radiology TI-RADS (81.8% versus 73.9%, P = .009; 94.0% versus 92.2%, P = .046). Specificity, accuracy, and positive predictive values were lower with the convolutional neural network than with the American College of Radiology TI-RADS (86.1% versus 93.7%, P < .001; 85.1% versus 89.1%, P = .003; and 64.0% versus 77.8%, P < .001). The area under the curve of the convolutional neural network was higher than that of the American College of Radiology TI-RADS (0.917 versus 0.891, P = .017).

CONCLUSIONS

The convolutional neural network provided diagnostic performance comparable with that of the American College of Radiology TI-RADS categories assigned by experienced radiologists.

Histogram analysis of greyscale sonograms to differentiate between the subtypes of follicular variant of papillary thyroid cancer

AIM

To evaluate the diagnostic value of histogram analysis using ultrasound (US) to differentiate between the subtypes of follicular variant of papillary thyroid carcinoma (FVPTC).

MATERIALS AND METHODS

The present study included 151 patients with surgically confirmed FVPTC diagnosed between January 2014 and May 2016. Their preoperative US features were reviewed retrospectively. Histogram parameters (mean, maximum, minimum, range, root mean square, skewness, kurtosis, energy, entropy, and correlation) were obtained for each nodule.

RESULTS

The 152 nodules in 151 patients comprised 48 non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTPs; 31.6%), 60 invasive encapsulated FVPTCs (EFVPTCs; 39.5%), and 44 infiltrative FVPTCs (28.9%). The US features differed significantly between the subtypes of FVPTC. Discrimination was achieved between NIFTPs and infiltrative FVPTC, and between invasive EFVPTC and infiltrative FVPTC using histogram parameters; however, the parameters were not significantly different between NIFTP and invasive EFVPTC.

CONCLUSION

It is feasible to use greyscale histogram analysis to differentiate between NIFTP and infiltrative FVPTC, but not between NIFTP and invasive EFVPTC. Histograms can be used as a supplementary tool to differentiate the subtypes of FVPTC.

Can probiotics enhance vaccine-specific immunity in children and adults?

The growing use of probiotics by the general public has heightened the interest in understanding the role of probiotics in promoting health and preventing disease. General practitioners and specialists often receive inquiries from their patients regarding probiotic products and their use to ward off systemic infection or intestinal maladies. Enhanced immune function is among the touted health benefits conferred by probiotics but has not yet been fully established. Results from recent clinical trials in adults suggest a potential role for probiotics in enhancing vaccine-specific immunity. Although almost all vaccinations are given during infancy and childhood, the numbers of and results from studies using probiotics in pediatric subjects are limited. This review evaluates recent clinical trials of probiotics used to enhance vaccine-specific immune responses in adults and infants. We highlight meaningful results and the implications of these findings for designing translational and clinical studies that will evaluate the potential clinical role for probiotics. We conclude that the touted health claims of probiotics for use in children to augment immunity warrant further investigation. In order to achieve this goal, a consensus should be reached on common study designs that apply similar treatment timelines, compare well-characterised probiotic strains and monitor effective responses against different classes of vaccines.

Antimelanogenic effects of luteolin 7-sulfate isolated from Phyllospadix iwatensis Makino

BACKGROUND

Abnormal deposition of melanin may cause an aesthetic skin problem; therefore, the control of unwanted excessive melanin synthesis is the major goal of cosmetic research.

OBJECTIVES

To identify novel tyrosinase (TYR) inhibitors from marine plants and examine their cellular antimelanogenic effects.

METHODS

The extracts of 50 marine plants endemic to Korea were screened against human TYR. Active constituents were then isolated from the selected plant extracts that showed potential and their chemical structures elucidated. Furthermore, their antimelanogenic effects were examined using murine melanoma B16/F10 cells and human epidermal melanocytes (HEM).

RESULTS

Among the tested extracts, that of Phyllospadix iwatensis Makino exhibited the strongest human TYR inhibitory activity. The active constituents were purified from the butanol fraction of the P. iwatensis extract and identified as hispidulin 7-sulfate and luteolin 7-sulfate. Luteolin 7-sulfate inhibited human TYR more strongly than hispidulin 7-sulfate, luteolin, hispidulin and arbutin. Furthermore, luteolin 7-sulfate showed lower cytotoxicity than luteolin in both B16/F10 cells and HEM. Luteolin 7-sulfate attenuated cellular melanin synthesis more effectively in B16/F10 cells and HEM stimulated by α-melanocyte-stimulating hormone and l-tyrosine than arbutin.

CONCLUSIONS

This study demonstrates that luteolin 7-sulfate isolated from P. iwatensis is a human TYR inhibitor with advantageous antimelanogenic properties, and would be useful for development as a therapeutic agent for the control of unwanted skin pigmentation.

A risk-adapted approach using US features and FNA results in the management of thyroid incidentalomas identified by 18F-FDG PET

PURPOSE

To assess the risk of malignancy of thyroid incidentalomas found on 18F-FDG PET/CT by US features and cytologic results, and to evaluate the clinical usage of a combination of US features and cytology for post-FNA management of thyroid incidentalomas on 18F-FDG PET/CT.

MATERIALS AND METHODS

From September 2006 to December 2008, 132 patients with 134 thyroid incidentalomas detected on 18F-FDG PET/CT who had undergone US and US-FNA were included in this study. We evaluated the malignancy rate of thyroid incidentalomas in different subgroups subdivided by US features and US-FNA cytology results. Several variables were compared between the benign and malignant group.

RESULTS

The risk of malignancy was 58.2 % (78/132) in thyroid incidentalomas on 18F-FDG PET/CT. Age, gender, and tumor size were not significantly different between the malignant and benign group.  Malignancy rate of thyroid incidentalomas was significantly higher in the suspicious malignant (88.9 %) than in the probably benign group (11.3 %) on US (p < 0.001). Malignancy rates were high in thyroid nodules with "malignancy", "suspicious for malignancy", or "follicular neoplasm" on cytologic results, regardless of US features. However, malignancy rates of thyroid incidentalomas with "unsatisfactory" or "benign" results on cytology were higher in the suspicious malignant (75 %, 12.5 %, respectively) than in the probably benign (0 %) group on US. 

CONCLUSIONS

This study demonstrated that the risk of malignancy was high in thyroid incidentalomas on 18F-FDG PET/CT even without suspicious US features. However, there was no malignancy in nodules with no suspicious US features and benign cytology. Based on these results, we concluded that US may not replace FNA in the diagnosis of PET incidentalomas, and that a follow-up may be considered of thyroid incidentalomas with benign cytology and no suspicious US features.

Interobserver variability and diagnostic performance in US assessment of thyroid nodule according to size

PURPOSE

To evaluate the interobserver variability for US assessments of thyroid nodules and analyze the diagnostic performances of US assessments in thyroid nodules according to nodule size.

MATERIALS AND METHODS

This was an IRB-approved retrospective study with waiver of informed consent. A total of 400 surgically-confirmed thyroid nodules were included. Nodules were divided into 4 groups by size; group 1 (nodule size < 5 mm), group 2 (5 mm ≤ nodule size < 10 mm), group 3 (10 mm ≤ nodule size < 20 mm), and group 4 (nodule size ≥ 20 mm). Three experienced (7 - 10 years) radiologists retrospectively reviewed the US images. Agreement of each US descriptor and final US assessment, and diagnostic performances were calculated in each group and compared.

RESULTS

Composition represented substantial or good agreement (k = 0.719 - 0.89). Margin showed the lowest agreement (k = 0.322 - 0.365). Individual kappa values for final assessment according to nodule size were as follows: group 1 (k = 0.674), group 2 (k = 0.596), group 3 (k = 0.674), and group 4 (k = 0.673). Specificity, PPV, and accuracy were significantly different among the groups with different size (p value < 0.05) and lowest in group 1. NPV, specificity, PPV and accuracy except PPV of observer 3 increased with nodule size (p < 0.05).

CONCLUSION

Interobserver agreements were relatively good (k = 0.637) in final US assessment regardless of nodule size in experienced radiologists. High false-positive rate was observed in US assessment in nodules less than 5 mm in maximum diameter.

Is US-guided core needle biopsy (CNB) enough in probably benign nodules with interval growth?

PURPOSE

To investigate whether ultrasound-guided 14-gauge core needle biopsy (US-CNB) is efficient in the diagnosis of probably benign lesions showing interval growth on follow-up US. 

MATERIALS AND METHODS

From March 2008 to August 2009, 116 breast lesions in 113 women (mean age: 41.2 years, range: 19 - 63 years) which were initially assessed as category 3 showing interval growth on follow-up US underwent US-CNB, and subsequent US-guided vacuum-assisted excision, surgical excision or follow-up US for at least 12 months. Diagnostic performances of US-CNB were evaluated with histopathologic results and follow-up US as standard reference. Clinical features of the patient and lesions characteristics including follow-up interval (I), the most increased diameter (D), D per I, increased volume (%V) and %V per I were calculated and compared.

RESULTS

Of the 116 lesions, 4 lesions were diagnosed as malignancy and 112 as benign on final pathology. Malignancy rate of probably benign lesions showing interval growth was 3.4 % (4/116). Incorrect biopsy rate was 0.9 % (1/116). Palpability or newly developed suspicious US features were more associated with malignancy, 75.0 to 13.4 % and 50.0 to 25.9 %, respectively, but without significance (p = 0.063 and 0.290). Significant differences were seen in average rank when comparing between benign and malignancy in D, %V, D per follow-up interval (I), and %V/I (p = 0.037, 0.017, 0.043 and 0.009, respectively).

CONCLUSION

US-CNB is an efficient diagnostic method for probably benign lesions showing interval growth, with discordant biopsy rate of 0.9 %.

Comparison of the underestimation rate in cases with ductal carcinoma in situ at ultrasound-guided core biopsy: 14-gauge automated core-needle biopsy vs 8- or 11-gauge vacuum-assisted biopsy

OBJECTIVE

The objective of this study was to compare the underestimation rate of invasive carcinoma in cases with ductal carcinoma in situ (DCIS) at percutaneous ultrasound-guided core biopsies of breast lesions between 14-gauge automated core-needle biopsy (ACNB) and 8- or 11-gauge vacuum-assisted biopsy (VAB), and to determine the relationship between the lesion type (mass or microcalcification on radiological findings) and the DCIS underestimation rate.

METHODS

We retrospectively reviewed imaging-guided biopsies of breast lesions performed from February 2003 to August 2008. 194 lesions were diagnosed as DCIS at ultrasound-guided core biopsy: 138 lesions in 132 patients by 14-gauge ACNB, and 56 lesions in 56 patients by 8- or 11-gauge VAB. The histological results of the core biopsy samples were correlated with surgical specimens. The clinical and radiological findings were also reviewed. The histological DCIS underestimation rates were compared between the two groups and were analysed for differences according to the clinical and radiological characteristics of the lesions.

RESULTS

The DCIS underestimation rate was 47.8% (66/138) for 14-gauge ACNB and 16.1% (9/56) for VAB (p<0.001). According to the lesion type on sonography, DCIS underestimation was 43.4% (63/145) in masses (47.6% using ACNB and 15.8% using VAB; p=0.012) and 24.5% (12/49) in microcalcifications (50.0% using ACNB and 16.2% using VAB; p=0.047).

CONCLUSION

The underestimation rate of invasive carcinoma in cases with DCIS at ultrasound-guided core biopsies was significantly higher for ACNB than for VAB. Furthermore, this difference does not change according to the lesion type on ultrasound. Therefore, ultrasound-guided VAB can be a useful method for the diagnosis of DCIS lesions presented as either mass or microcalcification.

Value of specimen radiographs in diagnosing multifocality of thyroid cancer

BACKGROUND

Specimen radiography has been used widely to evaluate the complete excision of calcified breast lesions but has not been evaluated for thyroid cancer.

METHODS

Specimen radiographs were evaluated retrospectively to identify additional cancers that were demonstrated only as calcifications. Receiver operating characteristic curve analysis was performed to compare the combination of specimen radiography and ultrasonography versus ultrasonography alone for detecting multifocality.

RESULTS

Some 122 thyroid cancer specimens were obtained from 122 patients between January and April 2008. Specimen radiography detected 27 cancers (18.5 per cent) not detected by ultrasonography. Diagnoses were changed after evaluation of specimen radiographs in three of these patients. The area under the curve of the combination of specimen radiography and ultrasonography was significantly higher than that of ultrasonography alone (P = 0.005).

CONCLUSION

Specimen radiography is a potentially useful tool for diagnosing cancer type and predicting the extent of thyroid cancer.

Diagnosis of breast cancer at dynamic MRI in patients with breast augmentation by paraffin or silicone injection

AIM

To determine the diagnostic performance of dynamic magnetic resonance imaging (MRI) for breast cancer in breasts augmented with liquid paraffin or silicone injection.

MATERIALS AND METHODS

Among 62 patients with breast augmentation by liquid paraffin or silicone injection who had undergone dynamic breast MRI at our institution, 27 women, who had pathological diagnosis or at least 1-year MRI follow-up, were included in this retrospective study and their MRI images were reviewed. For enhancing lesions on MRI, the morphological features, enhancement kinetics, and BI-RADS assessment category were analysed. The lesion characteristics at MRI were correlated with the final diagnosis based on the histopathological result or at least 1-year MRI follow-up.

RESULTS

Of the 27 patients, 17 enhancing lesions in 13 patients were found on MRI. All six lesions that were confirmed as malignancy showed suspicious morphological findings and type 2 or 3 enhancement kinetics, assigned to BI-RADS category 4 or 5. Of the remaining 11 benign lesions, 10 showed benign-favouring morphological findings, and all showed type 1 enhancement kinetics, assigned to BI-RADS category 2 or 4.

CONCLUSION

In patients with breasts injected with foreign material, MRI was used to successfully diagnose malignant breast lesions and could be the diagnostic method of choice. Analysis of the morphological and kinetic features at MRI in conjunction with clinical findings is essential.

Clinical outcomes of multicenter domino kidney paired donation

Domino kidney paired donation (KPD) is a method by which an altruistic living nondirected donor (LND) is allocated to a pool of incompatible donor-recipient pairs (DRP) and a series of KPDs is initiated. To evaluate the feasibility and clinical outcomes of multicenter domino KPD, we retrospectively analyzed a cohort of DRPs who underwent domino KPD between February 2001 and July 2007 at one of 16 transplant centers. One hundred seventy-nine kidney transplants were performed, with 70 domino chains initiated by altruistic LND. There were 45 two-pair chains, 15 three-pair chains, 7 four-pair chains, 2 five-pair chains and 1 six-pair chain. A majority of donors were spouses (47.5%) or altruistic LNDs (39.1%). DRPs with a blood type O recipient or an AB donor comprised 45.9% of transplanted DRPs. HLA mismatch improved in transplanted donors compared to intended donors in pairs enrolled to improve HLA mismatch (3.4 +/- 0.7 vs. 4.8 +/- 1.0, p < 0.001). One-year and 5-year graft survival rates were 98.3% and 87.7%, respectively, with a median follow-up of 46 months. One-year and 5-year patient survival rates were 97.2% and 90.8%, respectively. In conclusion, multicenter domino KPD could multiply the benefits of donation from LNDs, with patients and graft survival rates comparable to those seen with conventional KPD.

Zooming method (x 2.0) of digital mammography vs digital magnification view (x 1.8) in full-field digital mammography for the diagnosis of microcalcifications

The purpose of this study was to determine whether the interpretation of microcalcifications assessed on images zoomed (x 2.0) from digital mammograms is at least equivalent to that from digital magnification mammography (x 1.8) with respect to diagnostic accuracy and image quality. Three radiologists with different levels of experience in mammography reviewed each full-field digital mammography reader set for 185 patients with pathologically proven microcalcification clusters, which consisted of digital magnification mammograms (MAGs) with a magnification factor of 1.8 and images zoomed from mammograms (ZOOM) with a zoom factor of 2.0. Each radiologist rated their suspicion of breast cancer in microcalcific lesions using a six-point scale and the image quality and their confidence in the decisions using a five-point scale. Results were analysed according to display methods using areas under the receiver operating characteristic curves (A(z) value) for ZOOM and MAGs to interpret microcalcifications, and the Wilcoxon matched pairs signed rank test for image quality and confidence levels. There was no statistically significant difference in the level of suspicion of breast cancer between the ZOOM and MAG groups (A(z) = 0.8680 for ZOOM; A(z) = 0.8682 for MAG; p = 0.9897). However, MAG images were significantly better than ZOOM images in terms of visual imaging quality (p < 0.001), and the confidence level with MAG was better than with ZOOM (p < 0.001). In conclusion, the performance of radiologists in the diagnosis of microcalcifications using ZOOM was similar to that using MAGs, although image quality and confidence levels were better using MAGs.

Diffuse sclerosing variant of papillary carcinoma of the thyroid: ultrasound features with histopathological correlation

AIM

To evaluate the ultrasound (US) features of the diffuse sclerosing variant of papillary carcinoma (DSVPC) of the thyroid, with histopathological correlations.

MATERIALS AND METHODS

The US and histopathological findings of six patients with surgically proven DSVPC of the thyroid were retrospectively assessed.

RESULTS

Most of cases showed diffuse, scattered microcalcifications with or without associated masses and underlying heterogeneous hypoechogenicity at the site of the DSVPC in the thyroid. At ultrasound, scattered microcalcifications and heterogeneous hypoechogenicity seen in the DSVPC correlated to psammoma bodies and lymphocytic infiltration at histopathological review.

CONCLUSION

DSVPC of the thyroid usually manifested as diffuse scattered microcalcifications and associated suspicious mass on ultrasound. These findings are not specific for the DSVPC of the thyroid. However, in relatively young patients with suspicious masses associated with underlying diffuse scattered microcalcifications on US, the possibility of DSVPC should be included in differential diagnosis.

Pioglitazone, a synthetic ligand for PPARγ, induces apoptosis in RB-deficient human colorectal cancer cells

No published data are available about the expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and the role of PPARgamma in retinoblastoma protein (RB)-deficient human colorectal cancer (CRC) cells (SNU-C4 and SNU-C2A). Our aim was to investigate whether PPARgamma is expressed in SNU-C4 and SNU-C2A cells and to elucidate possible molecular mechanisms underlying the effect of pioglitazone, a synthetic ligand for PPARgamma, on cell growth in these cell lines. RT-PCR and Western blot analysis showed that both human CRC cell lines expressed PPARgamma mRNA and protein. Pioglitazone inhibited the cell growth of both cell lines through G2/M phase block and apoptosis. In addition, pioglitazone caused a down-regulation of the X chromosome-linked inhibitor of apoptosis (XIAP), Bcl-2, and cyclooxygenase-2 (COX-2) under conditions leading to PPARgamma down-regulation. These results suggest that pioglitazone may have therapeutic relevance or significance in the treatment of human CRC, and the down-regulation of XIAP, Bcl-2, and COX-2 may contribute to pioglitazone-induced apoptosis in these and other RB-deficient cell lines and tumors.

The impact of donor and recipient age on the outcome of kidney transplantation

BACKGROUND

As survival has improved in the general population over the last few decades, the age of patients participating in renal transplantation has also increased. This study sought to investigate the impact of donor and recipient age as predictors of long-term graft survival in renal transplantation.

MATERIALS AND METHODS

We analyzed transplantation outcomes in 598 patients who received renal transplants from 1979 to 2002. Patients were divided into 4 groups according to their age at renal transplantation. Group A (donor age <50 years, recipient age >50 years, n = 19/3.2%); group B (donor age >50 years, recipient age <50 years, n = 153/25.5%); group C (donor age <50 years, recipient age >50 years, n = 69/11.6%), and group D (donor age <50 years, recipient age <50 years, n = 357/59.8%). Univariate analysis to assess the effect of donor and recipient age as predictor factors of graft outcome was complimented by Kaplan-Meier and log-rank methods to assess graft survival with P < 1.05 considered significant.

RESULTS

In the elderly donor group, graft survival was 92.8% at 1 year and 85.6% at 3 years; in the younger donor group, they were 93.4% and 90.2%, respectively, a difference that was statistically significant (P = .02). Univariate analysis of age factors showed a significant reduction in graft survival among recipients who received kidneys transplants from donors older than 50 years, although recipient age >50 years was not found to be an independent risk factor. The incidence of acute rejection was 24.6% in the elderly donor group and 23.5% in the younger donor group (P = not significant). Among the 4 groups, the best result was group D with 1-year and 3-year graft survival rates of 93.3% and 90.5%, respectively, but this result was not statistically significant.

CONCLUSIONS

These results may help the design for transplantation strategies for kidneys procured from elderly donors and for allocation to elderly recipients.

The impact of sex and age matching for long-term graft survival in living donor renal transplantation

BACKGROUND

Deficient functional renal mass leads to progressive renal injury owing to the detrimental effects of glomerular hyperfiltration. Therefore, renal transplant mass is an important determinant of outcome.

MATERIALS AND METHODS

We retrospectively analyzed 614 living donor renal transplantations performed from 1979 to 2002. Patients were divided into 4 groups according to donor-recipient gender differences: group 1 (male to male), group 2 (male to female), group 3 (female to male), and group 4 (female to female). We analyzed the clinical and immunological data to compare the 4 groups with respect to long-term graft survival, age gender, acute rejection episodes an HLA matching. We used the Kaplan-Meier method with the log-rank test to assess graft survival.

RESULTS

The actuarial graft survival rate was 86.24% at 5 years for donors younger than 50 years of age compared with 73.15% for those older than 50 years (P = .0000). The graft survival from younger donors than recipients was 85.23% at 5 years compared with 80.35% for older donors (P = .0213). The graft survival of group 3 (female donor to male recipient) was 75.12% at 5 years compared with 85.72%, 85.33%, and 83.16% for groups 1, 2, and 4, respectively (P = .0165). The main parameters significantly associated with graft survival were donor age (P = .0000), acute rejection episode (P = .0000), donor gender (P = .0215). HLA-DR matching (P = .0516), and donor and recipient age matching (P = .0213).

CONCLUSIONS

The results suggest that the sex and age matching between donors and recipients should be considered as a criterion in the choice of donor and recipient pairs for living donor renal transplantation.

WITHDRAWN: The Impact of Gender and Age Matching for Long-Term Graft Survival in Living Donor Renal Transplantation

In renal transplantation, donor age and allograft size are known to have an important influence on the outcome of the graft reflecting functional renal mass. Women tend to have smaller kidneys with 17% fewer nephrons than male kidneys. The number of glomeruli per kidney as well as the mean glomerular volume closely correlate with kidney weight and negatively correlate with subject age. We evaluated the impact of gender and age matching in living-donor renal transplantation on long-term graft survival.

MATERIALS AND METHODS

Four groups were discerned among 614 renal transplants, according to donor and recipient gender: Group 1 was male donor to male recipient; Group 2 was male donor to female recipient; Group 3 was female donor to male recipient; and Group 4 was female donor to female recipient. We analyzed long-term graft survival and risk factors between the four groups as well as according to age matching. Statistical significance was determined by the Kaplan-Meier method and log rank test (P < .05).

RESULT

The graft survival rates at 1, 3, 5, and 10 years were 92.62%, 88.13%, 82.37%, and 76.07%, respectively. The risk factors affecting long-term graft survival were donor age, donor gender, acute rejection rate, and HLA-DR matching. Among the four groups, the graft survival rates of Group 3 (female donor to male recipient) were significantly different from the other groups (P = .0165). Also, the long-term graft survival rates according to age differences were significantly different between older donors than recipients and younger donors than recipients in each group (P = .0213).

CONCLUSION

The importance of inadequate renal mass is magnified in high-risk recipients. Age matching could perhaps improve the results of transplantation, particularly when kidneys from older donors are used. Consideration of age and gender as criteria for the choice of donors and recipients may be considered in organ allocation.

Long-Term Graft Outcome of Living Donor Renal Transplantation: Single Center Experience

The number of potential renal transplant recipients far exceeds the number of cadaveric donors. For this reason, living-related donors (LRD) and living-unrelated donors (LURD) have been used to decrease the cadaveric donor shortage. We analyzed 571 living donor transplants for 25 years in our center.

MATERIALS AND METHODS

From 1978 to 2003, 571 patients underwent LRD (n = 253), or LURD (n = 318) kidney transplantation. The patients were divided into precyclosporine era (from 1978 to 1987, n = 44; era I), cyclosporine era (from 1988 to 1997, n = 367, era II), and cyclosporine plus mycophenolate-mofetil era (from 1998 to 2003, n = 160, era III). We compared the graft survival rate of the recipients according to the immunosuppressants, analyzing the variables of donor and recipient age, sex, HLA matching, and acute rejection rate. We also compared long-term survival rates between LRD and LURD.

RESULTS

The 1- and 10-year graft survival rates of all patients were 93.4% and 77.4%, respectively. The 1- and 10- year graft survival rates were 75.0% and 36.3% in era I; and 94.8 % and 80.2% in era II. The 1- and 5-year graft survival rates were 96.6% and 93.3% in era III (P < .001). The occurrence rate of an acute rejection episode was 11.4% (era I), 21.8% (era II), and 14.4% (era III) (P = .056). The 1- and 5-year graft survival rates were 92.3% and 81.7% among LRD transplants, and 94.2% and 86.9% among LURD transplants, respectively (P = .122).

DISCUSSION

The graft survival rates of living-donor transplants are improving due to advances in patient care and new immunosuppressive agents.

Analysis of Allograft Biopsy Specimens in Renal Transplants With Proteinuria: Is Proteinuria a Culprit of Graft Loss?

It has been proposed that proteinuria occurring after renal transplantation may be not only a marker but also a culprit of allograft dysfunction. We retrospectively analyzed the data from 55 patients who underwent transplant renal biopsy for proteinuria and/or azotemia occurring beyond 1 year after transplantation. Proteinuria was considered as significant when > or = 30 mg/dL, and the results of transplant biopsy were categorized according to the Banff 97 classification. Logistic regression was used to estimate odds ratios (OR) for graft loss associated with proteinuria and transplant pathology. The patients were followed for 86.0 +/- 32.8 months after transplantation, and transplant biopsy was performed at 54.1 +/- 31.0 months. Proteinuria at 1 year after transplantation noted in 29.1% of patients was not significantly associated with graft loss (OR = 1.94, 95% CI from 0.59 to 6.41). In addition, proteinuria at the time of transplant biopsy was not significantly associated with graft loss. Chronic allograft nephropathy was the most frequent transplant pathology. Only glomerulonephritis was significantly associated with proteinuria at the time of the transplant biopsy. On the other hand, graft loss was significantly associated with the presence of proteinuria both at 1 year after transplant biopsy and at the final follow-up. These results suggest that posttransplantation proteinuria is an important marker of graft dysfunction, but is not predictive of graft loss in biopsy-proven cases. Appropriate management guided by the results of a transplant biopsy may improve the outcome.

Pulmonary vascular dilation induced by L-ARGININE: correlation with induction of endothelial nitric oxide synthase in a rabbit model

PURPOSE

To determine whether oral administration of L-ARGININE induces pulmonary vascular dilation, and if this pulmonary vascular dilation correlates with induction of endothelial nitric oxide synthase (eNOS) in a rabbit model.

MATERIAL AND METHODS

Seven rabbits were fed with L-ARGININE dissolved in tap water. The degree of pulmonary vascular dilation was determined using thin-section computed tomography and the concentration of serum nitrite was measured. They were compared with four control animals. The pulmonary vascular dilation was correlated to serum levels of nitrite. Lung tissues were examined for induction of eNOS by immunohistochemistry.

RESULTS

An increased degree of pulmonary vascular dilation was found in the L-ARGININE-fed group compared to the control group (P<0.05). Serum levels of nitrite in the L-ARGININE-fed group were higher than those in the control group (P<0.05). Pulmonary vascular dilation correlated with serum levels of nitrite (r2=0.95, P<0.05). Induction of eNOS was increased in the L-ARGININE-fed group.

CONCLUSION

The administration of L-ARGININE causes pulmonary vascular dilation, which is most likely mediated via nitric oxide through increased induction of eNOS in a rabbit model.

Enhancement of phospholipase D activity by overexpression of amyloid precursor protein in P19 mouse embryonic carcinoma cells

It has been shown that phospholipase D (PLD) activity is stimulated by the beta-amyloid protein in neuronal cells. The aim of this study was to determine whether overexpression of the amyloid precursor protein (APP) affects the activity and the level of PLD expression in P19 embryonic carcinoma cells. We observed that the unstimulated basal PLD activity was higher in wild-type APP(695)-transfected cells than in non-transfected control cells. The protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), has been shown to activate PLD. PMA-stimulated PLD activity was 3-fold higher in the APP overexpressing cells than in the control cells. P19 cells express two distinct PLD isozymes, PLD1 and PLD2. The level of PLD2 expression was increased by APP overexpression. Although the PKC inhibitor, GF109203X, inhibited PMA-stimulated PLD activity, it did not affect the high basal PLD activity induced by APP overexpression. Neuronal differentiation of the P19 cells by retinoic acid did not affect the basal or PMA stimulated-PLD activity. Interestingly, APP overexpression in the differentiated P19 cells also led to an increase in PLD activity. The PLD activity of the P19 cells is apparently regulated by amyloid protein through both PKC-dependent and -independent mechanisms.

Endogenous production of nitric oxide by vascular endothelial growth factor down-regulates proliferation of choriocarcinoma cells

The trophoblast-like choriocarcinoma cell line BeWo expresses a receptor for vascular endothelial growth factor (VEGF) and proliferates in response to VEGF. Nitric oxide (NO) seems to play a key role in the VEGF-induced proliferation of endothelial cells but the NO mechanistic regulation of VEGF-stimulated trophoblast proliferation is presently unclear. We assessed the effect of exogenous VEGF on BeWo cell proliferation by [3H]thymidine incorporation. The VEGF-induced proliferation of BeWo cells was significantly increased by the NO synthase (NOS) inhibitor, N(omega)-nitro-l-arginine methyl ester (L-NAME), but was inhibited by the NO donor, sodium nitroprusside. Treatment of the cells with 10 ng/ml of VEGF increased not only eNOS expression but also NO production. The extracellular signal-regulated kinase (Erk) of the mitogen-activated protein kinase (MAPK) family was activated by VEGF as demonstrated by the phosphorylation of Erk in Western blots. The effects of VEGF on NO production and the expression of endothelial NOS (eNOS) were attenuated by treating BeWo cells with the selective inhibitor of MAPK kinase, PD98059. VEGF-stimulated proliferation of BeWo cells was inhibited by the tyrosine kinase inhibitor genistein but increased by PD98059. Other kinase inhibitors, including LY294002 (phosphoinositide 3-kinase inhibitor) and SB203580 (P38 MAPK inhibitor), had no effect on the proliferation of the cells and NO production. These results indicate that endogenous NO production down-regulates the VEGF-stimulated proliferation of BeWo cells and that the activation of Erk plays an important role in this mechanism.

Telomere length changes in patients with aplastic anaemia

To investigate telomere changes in patients with aplastic anaemia (AA) and clinical factors influencing the telomere dynamics, telomere length (TL) was measured in peripheral blood mononuclear cells using Southern blot analysis of 42 patients with AA and 39 healthy normal controls. Nineteen patients received supportive treatment only, while the remaining 23 patients received immunosuppressive therapy with anti-thymocyte globulin or anti-lymphocyte globulin +/- cyclosporin A. In AA patients, TL was on average 1.41 kb shorter than that of age-matched normal controls (P < 0.001). In patients treated with immunosuppression, the mean TL of non-responders was significantly shorter than that of age-matched normal controls (P < 0.001), while no difference in TL was detected in responders compared with controls. Positive correlation was observed between the extent of telomere shortening, the severity of neutropenia (P = 0.05) and the degree of mean corpuscular volume elevation (P = 0.005) at the time of the study. However, there was no correlation with time elapsed since diagnosis (P = 0.214). These findings suggest that haematopoietic stem cells in patients with AA rapidly lose TL at the onset of the disease. The TL shortening may reflect the severity of impairment of haematopoiesis.

Response to high-dose intravenous immune globulin as a valuable factor predicting the effect of splenectomy in chronic idiopathic thrombocytopenic purpura patients

This study was conducted to verify whether the response to high-dose intravenous immune globulin (IVIG) was related to the effect of splenectomy in chronic idiopathic thrombocytopenic purpura (ITP) patients. A total of 79 patients over 16 years of age were enrolled in this study. The response to the treatment was classified on the basis of the platelet count as no response (NR, <50 x 10(9)/l), incomplete response (IR, (50-150) x 10(9)/l), and complete response (CR, >150 x 10(9)/l). The response was evaluated after the infusion of high-dose IVIG, within 2 weeks after splenectomy (immediate response), and during a follow-up period of more than 6 months after splenectomy (sustained response), respectively. 58 patients (73.4%) showed responses (CR or IR) to high-dose IVIG. After splenectomy, immediate responses were observed in 73 patients (92%). The response to high-dose IVIG had no relationship with the immediate response to splenectomy (P = 0.333). A follow-up evaluation was possible with 58 patients; 6 patients with NR in immediate responses did not show any response during the follow-up period, and 17 patients relapsed within 6 months after immediate responses, so 35 patients (60.3%) had sustained responses. Responders to IVIG had significantly higher sustained response rates to splenectomy than non-responders (62% vs. 38%, P = 0.001). These results indicate that the response to high-dose IVIG could be a valuable factor predicting the sustained response to splenectomy in chronic ITP patients.

Radiologic findings of metastatic signet ring cell carcinoma to the breast from stomach

Two Korean women (41 and 23-years of age) presented with painful breast enlargement and redness. The involved breast was confirmed as metastatic signet ring cell carcinoma. Although metastatic signet ring cell carcinoma of the breast shows similar clinical symptoms to inflammatory breast cancer, the difference between the two is that this malignancy showed no microcalcifications or mass on radiographic findings (mammograms and US). Therefore, after the confirmation of signet ring cell carcinoma of the breast has been made, metastatic signet ring cell carcinoma should be considered if there are no microcalcifications or masses evident on radiographic findings.

Technetium-99m MDP bone scintigraphic findings of hypercalcemia in accelerated phase of chronic myelogenous leukemia

Hypercalcemia in accelerated phase of chronic myelogenous leukemia (CML) is very rare. Its pathogenesis is considered humoral hypercalcemia of malignancies mediated by parathyroid hormone-related protein (PTHrP). In severe hypercalcemia, calcifications in kidneys, skin, vessels, heart, and stomach may occur. Our two cases were admitted because of severe hypercalcemia in accelerated phase of CML. On Tc-99m methylene diphosphonate (MDP) bone scintigraphies, a marked tracer accumulation was seen in the lung, heart, stomach and kidney. We report increased tracer accumulation of multiple organs on Tc-99m MDP bone scintigraphy in two rare hypercalcemic patients with CML.

Dexamethasone enhances phospholipase D activity in M-1 cells

Phospholipase D (PLD) is an enzyme involved in signal transduction and widely distributed in mammalian cells. The signal transduction pathways and role for phospholipid metabolism during hormonal response in cortical collecting duct remain partly undefined. It has been reported that dexamethasone increases transepithelial transport in M-1 cells that are derived from the mouse cortical collecting duct. We investigated the expression and activity of PLD in M-1 cells. Basal PLD activity of M-1 cells cultured in the presence of dexamethasone (5 microM) was higher than in the absence of dexamethasone. Dexamethasone and ATP activated PLD in M-1 cells but phorbol ester did not stimulate PLD activity. Vasopressin, bradykinin, dibutyryl cyclic AMP, and ionomycin were ineffective in activating PLD of the cells. The PLD2 isotype was detected by immunoprecipitation but PLD1 was not detected in M-1 cells. Addition of GTPgammaS and ADP-ribosylation factor or phosphatidylinositiol 4,5-bisphosphate to digitonin-permeabilized cells did not augment PLD activity. In intact cells PLD activity was increased by sodium oleate but there was no significant change between dexamethasone treated- and untreated cells by oleate. These results suggest that at least two types of PLD are present in M-1 cells and PLD plays a role in the corticosteroid-mediated response of cortical collecting duct cells.

Cytokines secreted by lymphokine-activated killer cells induce endogenous nitric oxide synthesis and apoptosis in DLD-1 colon cancer cells

IL-2-activated killer lymphocytes (LAK cells) secrete inflammatory cytokines such as interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNFalpha) that can induce nitric oxide (NO) synthesis. We evaluated whether LAK cells could activate NO synthesis in human cancer cells. LAK cells and their culture supernatants induced NO synthesis in DLD-1 colon cancer cells in a dose-dependent manner. NO synthesis was inhibited completely by blocking antibodies to IFN-gamma, demonstrating a key role for this LAK cell cytokine in regulating NO synthesis. The addition of TNFalpha antibodies resulted in partial inhibition. Induction of iNOS mRNA and protein expression in DLD-1 cells was detected. Endogenous NO production inhibited DLD-1 cell proliferation and induced apoptosis, processes that were inhibitable by the NO synthase inhibitor N(G)-monomethyl-l-arginine. Our study has identified a novel, non-contact-dependent LAK cell cytotoxic mechanism: induction of growth inhibition and programmed cell death due to endogenous NO synthesis in susceptible human cancer cells.

Immunoglobulin G infusion treatment for women with recurrent spontaneous abortions and elevated CD56+ natural killer cells

We aimed to investigate the clinical effect of intravenous immunoglobulin G (IVIg) treatment in recurrent aborters with elevated peripheral blood CD56+ NK cell levels while on lymphocyte immunization, anticoagulation and prednisone treatment, with respect to subsequent live birth and reproductive outcome. Thirty-three women with recurrent abortions achieved alloimmune recognition after lymphocyte immunizations. All had autoimmune abnormalities and received preconception anticoagulation and prednisone treatment. At the time of positive pregnancy testing, 18 women with normal NK cell levels (<12%) and 6 with elevated NK cell levels (>12%) continued anticoagulation and prednisone treatment, and 9 with elevated NK cell level initiated additional IVIg treatment. The live birth rates of women with elevated NK cell level (>12%) who initiated post-conception IVIg treatment in addition to anticoagulation and prednisone (100.0%), women with normal NK cell levels (<12%) who continued anticoagulation and prednisone (83.3%) and women with elevated NK cell level (>12%) who continued anticoagulation and prednisone (33.3%) are significantly different (P=0.0065). Prevalence of intrauterine growth retardation and preterm delivery among 3 study groups were not different. In conclusion, post-conception IVIg treatment significantly improves reproductive outcome in women with elevated CD56+ NK cells with pregnancy who received preconception lymphocyte immunization, anticoagulation and prednisone treatment.

Downregulation of phospholipase D by protein kinase A in a cell-free system of human neutrophils

Agents which elevate cellular cAMP are known to inhibit the activation of phospholipase D (PLD) in human neutrophils. The PLD activity of human neutrophils requires protein factors in both membrane and cytosolic fractions. We have studied the regulation of PLD by the catalytic subunit of protein kinase A (cPKA) in a cell-free system. cPKA significantly inhibited GTPgammaS-stimulated PLD activity but had no effect on phorbol ester-activated PLD activity. Pretreatment of plasma membranes with cPKA and ATP inhibited subsequent PLD activation upon reconstitution with untreated cytosol. RhoA, which is known to be a plasma membrane activator of PLD, was dissociated from PKA-treated plasma membrane by addition of cytosol. Plasma membrane-associated RhoA in human neutrophils was phosphorylated by cPKA. The PKA-phosphorylated form of RhoA was more easily extracted from membranes by RhoGDI than the unphosphorylated form. These results suggest that inhibition of neutrophil PLD by PKA may be due to phosphorylation of RhoA on the plasma membrane.

The effects of two new antagonists of secretory PLA2 on TNF, iNOS, and COX-2 expression in activated macrophages

Phospholipase A2 (PLA2) regulates eicosanoid and platelet-activating factor production. It also plays an important role in the regulation of critical mediators in inflammatory diseases in which PLA2 activity is significantly enhanced during sepsis and multiple organ failure. Therefore, inhibitors of PLA2 activity offer themselves as target substances in the development of anti-inflammatory drugs. We identified 2 biflavonoids, bilobetin and ginkgetin, that can inhibit PLA2 activity. In experiments using 2-linol-[1-14C]PE as substrate both substances potently inhibited several kinds of type II 14-kDa PLA2 while inhibiting type I 14-kDa PLA2 to a lesser extent. We tested these PLA2 inhibitors for their ability to inhibit the production of tumor necrosis factor alpha (TNFalpha) and 2 enzymes, inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) in an assay system using lipopolysaccharide (LPS)-stimulated Raw264.7 macrophages. In Raw264.7cells, bacterial LPS induced the production of COX-2 and iNOS proteins as well as TNFalpha. The inhibitors consistently inhibited the production of TNFalpha in a dose-dependent manner. Moreover, treatment of the macrophages with bilobetin and ginkgetin shut down the production of nitrite, one of the stable end products of NO released into the culture supernatant. The decrease in NO products was accompanied by a decrease in iNOS protein level as assessed by Western blot probed with specific anti-iNOS antibody. Both inhibitors also reduced the expression of COX-2 protein in the LPS-stimulated cells, which coincided with the reduction in iNOS protein. These results, therefore, suggest that these two sPLA2 inhibitors may be useful for inhibiting the production of inflammatory cytokine and NO production in inflammatory diseases.

Lipoblastoma of the parietal pleura in a 7-month-old infant

A 7-month-old infant boy with pleural lipoblastoma is presented. The diagnosis was confirmed by operation. Radiologic findings consisted of a pleura-based mass with well-defined margin. The main differentiation is from liposarcoma, which is extremely rare in children under 3 years of age.

IGF-I and TGF-beta2 have a key role on regeneration of nitric oxide synthase (NOS)-containing nerves after cavernous neurotomy in rats

The molecular mechanism of nitric oxide synthase (NOS)-containing nerve regeneration is still unknown. It is believed that growth factors are involved in this phenomenon. We investigated the change of NOS containing nerve fibers and the mRNA expression of insulin like growth factor (IGF)-I, nerve growth factor (NGF), transforming growth factor (TGF)-alpha, TGF-beta1, TGF-beta2, TGF-beta3, vascular endothelial growth factor (VEGF), endothelial NOS (eNOS) and neuronal NOS (nNOS) on the penis after cavernous nerve neurotomy in rats. Male rats were divided into four groups: (1) sham operation (n = 14); (2) unilateral neurotomy of a 5 mm segment of the cavernous nerve (n = 21); (3) unilateral neurotomy with growth hormone (n = 14); and (4) bilateral neurotomy (n = 21). Electrostimulation of the intact cavernous nerve or pelvic ganglion were performed at one, three and six months. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining and immunohistochemistry were used to identify NOS in the penis. The gene expression for growth factors, eNOS and nNOS were investigated in corporal tissue by reverse transcriptase-polymerase chain reaction (RT-PCR). One month after neurotomy, both unilateral and bilateral neurotomy groups showed significant decreases in NOS-containing nerve fibers on the dorsal and intracavernosal nerves on the side of neurotomy. Significantly lower mRNA expression of nNOS, IGF-I and TGF-beta2, higher mRNA expression of eNOS and VEGF189 were shown in these groups. At three months, the number of NOS-containing nerve fibers in the unilateral neurotomy group increased only slightly, while the GH-treated group showed a significant increase. At six months, those in the intracavernosal nerve only increased in a significant amount (P < 0.0001), however mRNA expression of nNOS, IGF-I and TGF-beta2 showed a significant increase as early as at three months. After bilateral neurotomy, the NOS-positive nerve fibers in the dorsal and intracavernosal nerve were significantly decreased at one month and remained so at six months; no erectile response could be elicited by pelvic ganglion stimulation. In the unilateral neurotomy group at six months, more NOS-positive neurons in the pelvic ganglia were found on the intact side than on the side of the neurotomy (P < 0.003), indicating that the regeneration derived from pelvic ganglion neurons on the intact side. Furthermore, electrostimulation in the unilateral neurotomy group revealed a greater maximal intracavernosal pressure and a shorter latency period at six months than at one month (P < 0.014, P < 0.001, respectively). These data suggest that IGF-I and TGF-beta2 may play a key role in the regeneration of nNOS-containing nerve fibers in the dorsal and intracavernosal nerves, and eNOS increases temporarily in the intracavernous involving VEGF189 after unilateral cavernous nerve injury.

The role of growth factor on regeneration of nitric oxide synthase (NOS)--containing nerves after cavernous neurotomy in the rats

Nitric oxide synthase (NOS) containing nerve regeneration can be seen six months after unilateral cavernous nerve neurotomy in rats. However, its molecular mechanism is still unknown. It is believed that growth factors are involved in this phenomenon. In this study we investigated the change of NOS containing nerve fibers and the RNA expression of insulin like growth factor (IGF)-I, nerve growth factor (NGF), transforming growth factor (TGF)-alpha, TGF-beta 1, TGF-beta 2. TGF-beta 3 and NOS on the penis after cavernous nerve neurotomy in rats. Male rats were divided into three groups: (1) sham operation (N = 10); (2) unilateral neurotomy of a 5 mm segment of the cavernous nerve (N = 15); and (3) bilateral neurotomy (n = 15). Electrostimulation of the intact cavernous nerve or pelvic ganglion was performed at one, three and six months. Nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was used to identify NOS in the penile nerve fibers. The gene expression for growth factors and bNOS was investigated in corporal tissue by reverse transcriptase-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. One month after neurotomy, both unilateral and bilateral neurotomy groups showed a significant decrease in NOS-containing nerve fibers on the dorsal and intracavernosal nerves on the side of neurotomy, and a significantly lower mRNA expression of bNOS, IGF-I and TGF-beta 2. At three months, the number of NOS-containing nerve fibers in the unilateral neurotomy group increased only slightly but at six months those in the intracavernosal nerve increased in a significant amount (P < 0.0001), however mRNA expression of bNOS, IGF-I and TGF-beta 2 showed a significant increase as early as at three months. After bilateral neurotomy, the NOS-positive nerve fibers in the dorsal and intracavernosal nerve were significantly decreased at one month and remained so at six months; no erectile response could be elicited by pelvic ganglion stimulation. In the unilateral neurotomy group at six months, more NOS-positive neurons in the pelvic ganglia were found on the intact side than on the side of the neurotomy (P < 0.003), indicating that the regeneration derives from pelvic ganglion neurons on the intact side. Furthermore, electrostimulation in the unilateral neurotomy group revealed a greater maximal intracavernosal pressure and a shorter latency period at six months than at one month (P < 0.014, P < 0.001, respectively). These data suggest that IGF-I and TGF-beta 2 may play a key role in regeneration of NOS-containing nerve fibers in the dorsal and intracavernosal nerves after unilateral cavernous nerve injury.

Comparisons of prognostic scoring systems for myelodysplastic syndromes: a Korean multicenter study

We have conducted a multicenter collaborative retrospective analysis to evaluate clinical characteristics and to compare prognostic scoring systems of 149 Korean patients with myelodysplastic syndromes (MDS). The median age of the patients was 53 years (range 17-82 years) with high of the patients being younger than 40 years. Median survival was 22.6 months, and 25 patients (17%) progressed to acute myelogenous leukemia (AML) with a median interval of 6 months (range 1-45 months). Major independent variables assessed by multivariate analysis were FAB subtypes and bone marrow (BM) blast percentages for survival and BM blast percentages for AML transformation. To compare the various scoring systems in the prediction for survival and transformation to AML, FAB, Sanz and Bournemouth scoring systems were applied to all patients, while the international prognostic scoring system (IPSS), Lille and Toyama scoring systems were applied to 91 patients. The Sanz scoring system (P < 0.0001), FAB classification (P < 0.0001), IPSS (P < 0.001), and Toyama scoring system (P < 0.005) were highly predictive for survival showed greater discrimination than that of the other systems. For AML transformation, the IPSS (P < 0.0001), Toyama scoring system (P < 0.0001), FAB classification (P < 0.0001), and Lille scoring system (P < 0.005) successfully discriminated risk groups. Although the prognostic factors and the distribution of age were different from those in Western reports, the IPSS and Toyama scoring system were applicable for predicting survival and leukemic transformation in Korean patients with MDS.

Trp-Lys-Tyr-Met-Val-D-Met stimulates superoxide generation and killing of Staphylococcus aureus via phospholipase D activation in human monocytes

Among the phagocytic leukocytes, monocytes have the important role of clearing out parasitic microorganisms. They accomplish this through production of toxic metabolites of oxygen. Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm), a peptide that stimulates phosphoinositide (PI) hydrolysis in human leukocytes, including monocytes, binds to a unique cell surface receptor and stimulates superoxide generation, killing of Staphylococcus aureus, and activation of phospholipase D (PLD) in human monocytes. Preincubation of the cells with a PI-specific phospholipase C (PLC) inhibitor (U-73122), protein kinase C inhibitor (GF109203X), or intracellular Ca2+ chelator (BAPTA/AM) before the peptide stimulus totally inhibits the peptide-induced PLD activation and superoxide generation. On the other hand, tyrosine kinase inhibitor genistein only partially inhibits the peptide-induced processes. The peptide-induced bacteria killing activity shares regulatory mechanisms for PLD activation with the superoxide generation, which is inhibited in the presence of 1-butanol. We suggest that the peptide stimulates PLD downstream of PLC activation and PLD activation in turn is essential for the peptide-induced immunological functions such as the superoxide generation and killing of bacteria by human monocytes.

Immunopathology of the implantation site utilizing monoclonal antibodies to natural killer cells in women with recurrent pregnancy losses

PROBLEM

Placental lesions of 71 women with documented recurrent spontaneous abortions of unknown etiology were evaluated using immunohistochemical staining.

METHOD OF STUDY

Placental tissue blocks (less than 12 weeks gestation) from prior pregnancy losses were obtained, recut, and analyzed utilizing monoclonal antibody to identify the trophoblast (cytokeratin 8/18) and natural killer (NK) cells (CD57) at the implantation site. The following features were evaluated: trophoblast invasion pattern; syncytium formation; vasculitis and thromboembolism of decidual vessels; decidual inflammation; decidual necrosis; fibrin deposition at the decidual necrosis site; mononuclear-cell infiltration in villi and intervillous space; perivillous fibrin deposition; trophoblast morphology; and quantitation of CD57+ NK cells within the decidual tissue near the implantation site. Controls consisted of 20 healthy women with no history of recurrent pregnancy losses, who had their pregnancies electively terminated.

RESULTS

Of the women studied, 29.6% demonstrated elevated CD57+ NK cells at the implantation site (P = 0.030), 54.1% had inadequate cytotrophoblast invasion depth (P = 0.000), 44.1% demonstrated inadequate syncytium formation (P = 0.004), and 33.9% presented thromboembolism in decidual vessels (P = 0.025).

CONCLUSION

Some women with recurrent spontaneous abortions demonstrate abnormal placental lesions at the implantation site. Immunopathologic evaluation of the placental implantation site that terminated in a spontaneous abortion may reveal the immunopathogenesis of previous pregnancy losses.

Natural killer (NK) cell subsets and NK cell cytotoxicity in women with histories of recurrent spontaneous abortions

PROBLEM

Natural Killer (NK) cell measurement and NK cytotoxicity are two measurements for assessing the cellular immune response. Both of the techniques have been reported to be prognostic for women with recurrent spontaneous abortion (RSA). We evaluated the two methods to determine the relationship of the two assays. Because both methods portend to evaluate the same process, the previous clinical data suggested that the methods evaluate the same phenomena. We undertook these studies to determine whether simple NK cell counts may be sufficient in the evaluation of NK activity in RSA.

METHOD OF STUDY

The NK cell cytotoxicity at effector-to-target ratios of 50:1 and 25:1 was determined using a flow cytometric NK cell cytotoxicity assay. These values were then correlated with the percentages and absolute counts of three peripheral blood NK cell subsets.

RESULTS

The data indicate that the flow cytometric assay is reproducible and precise and can be successfully used to evaluate patient samples. Linear regression analysis indicated a lack of correlation between peripheral blood NK cell cytotoxicity and percentages or absolute counts of CD56+CD16+, CD56+CD16- or CD3+CD56+ lymphocyte subsets (range of correlation coefficients, 0.1-0.3).

CONCLUSIONS

NK cell cytotoxicity and peripheral blood NK cell values measure different aspects of NK cells and do not correlate. These data indicate that simple enumeration of NK cells may not be sufficient in the evaluation of NK cells in RSA.

Calyculin A modulates activation of the NADPH-oxidase in Me2SO-differentiated HL-60 cells

Human promyelocytic leukemia cells (HL-60) have been used as a model system in which to study the effects of protein phosphatase inhibitors on NADPH-oxidase activation. Since O2- is generated by NADPH-oxidase, we examined the effect of calyculin A pretreatment on oxidase activation in response to various agonists. When Me2SO-differentiated HL-60 cells were treated with calyculin A prior to the addition of phorbol 12-myristate 13-acetate (PMA), O2- production was inhibited; however, calyculin A enhanced O2- production by N-formyl-methionyl-leucyl-phenylalanine (FMLP). The decreased O2- production seen with calyculin A pretreatment followed by PMA may be due to diminished translocation of the p47-phox and p67-phox, cytosolic components of the oxidase, and inhibition of arachidonic acid release. Interestingly calyculin A pretreatment followed by either agonist significantly enhanced mitogen-activated-protein kinase (MAPK) activity. The differential effects of pretreatment with calyculin A on subsequent oxidase stimulation elicited by FMLP or PMA provide further evidence for substantial heterogeneity in the activation of the respiratory burst.