HOXD8 suppresses renal cell carcinoma growth by upregulating SHMT1 expression

Amplification of amino acids synthesis is reported to promote tumorigenesis. The serine/glycine biosynthesis pathway is a reversible conversion of serine and glycine catalyzed by cytoplasmic serine hydroxymethyltransferase (SHMT)1 and mitochondrial SHMT2; however, the role of SHTM1 in renal cell carcinoma (RCC) is still unclear. We found that low SHMT1 expression is correlated with poor survival of RCC patients. The in vitro study showed that overexpression of SHMT1 suppressed RCC proliferation and migration. In the mouse tumor model, SHMT1 significantly retarded RCC tumor growth. Furthermore, by gene network analysis, we found several SHMT1-related genes, among which homeobox D8 (HOXD8) was identified as the SHMT1 regulator. Knockdown of HOXD8 decreased SHMT1 expression, resulting in faster RCC growth, and rescued the SHMT1 overexpression-induced cell migration defects. Additionally, ChIP assay found the binding site of HOXD8 to SHMT1 promoter was at the -456~-254 bp region. Taken together, SHMT1 functions as a tumor suppressor in RCC. The transcription factor HOXD8 can promote SHMT1 expression and suppress RCC cell proliferation and migration, which provides new mechanisms of SHMT1 in RCC tumor growth and might be used as a potential therapeutic target candidate for clinical treatment.

Accelerated Epigenetic Aging Mediates the Association between Vitamin D Levels and Knee Pain in Community-Dwelling Individuals

OBJECTIVES

To examine the relationship between Vitamin D status and pain intensity and disability in individuals with and without knee pain, and to examine the role of epigenetics in this relationship.

DESIGN

Cross-sectional analysis of data from the UPLOAD-2 study (Understanding Pain and Limitations in OsteoArthritic Disease-2).

PARTICIPANTS

189 individuals aged 45-65 years and older.

MEASUREMENTS

Serum Vitamin D levels, pain related interference and characteristic pain intensity measures, and the epigenetic clock GrimAge derived from blood analyses.

RESULTS

Lower Vitamin D was associated with advanced epigenetic aging (AgeAccelGrim), greater pain and disability and that (AgeAccelGrim) mediated the relationship between Vitamin D status and self-reported pain (ab = -0.0799; CI [-0.1492, -0.0237]) and disability (ab = -0.0669; CI [-0.1365, -0.0149]) outcomes.

CONCLUSION

These data support the notion that lifestyle factors such as nutrition status play a key role in aging process, as well as the development and maintenance of age-related diseases such as pain. Modifying nutrition status could help promote healthy aging and reduce pain.

[The 485th case: fever of undetermined origin and hypoxemia]

A 49-year-old male was admitted to Peking Union Medical College Hospital presented with fever for more than half a year. The patient was diagnosed as Sjogren's syndrome at local hospital. After oral prednisone 60 mg per day was given, the fever alleviated, but recurred after prednisone tapered to 40 mg/d. Both blood culture and stool culture were positive for Salmonella enteritidis. Antibiotics including ceftazidime, ceftriaxone, cilastatin-imipenem were sequentially administrated for 4 weeks, yet not effective. Although there were not respiratory symptoms or certain abnormalities on high-resolution chest CT, arterial blood gas indicated hypoxemia. Serum lactate dehydrogenase and β2 micro-globulin were elevated, and the lung function test demonstrated significant impairment of diffusion function. Positron emission tomography-computed tomography (PET/CT)scan suggested that high fluorodeoxyglucose uptake was diffusely seen in both lungs. The patient was finally diagnosed as pulmonary intravascular large B-cell lymphoma (IVLBCL) by transbronchial lung biopsy. This case aims to emphasize the differentiation diagnoses of pulmonary intravascular lymphoma from common situations.

[The spectrum of pathogens in 187 cases of pulmonary fungal disease diagnosed by histopathology-a retrospective analysis]

Objective: To investigate the spectrum of pathogens causing lung fungal disease diagnosed by histopathology through histochemical special staining, compared to the fungal culture results, and to further evaluate the diagnostic value of histochemical special staining in pulmonary fungal disease. Methods: We performed a retrospective analysis of 187 cases of pulmonary fungal disease diagnosed by histopathology in Peking Union Medical College Hospital from 2001 to 2015 (including 92 cases with pulmonary resection or open lung biopsy, 33 with percutaneous lung biopsy and 62 ones with fiberoptic bronchoscopic lung biopsy). All cases were treated with hexamine silver, PAS, mucus carmine and acid-fast staining in addition to conventional HE staining. The clinical records and the fungal culture results were reviewed. Results: There were 103 male and 84 female patients, aged from 12 to 70 years [average (48±14) years]. There were 85 cases(45.5%) of pulmonary aspergillosis(including 60 cases of invasive infection and 25 cases of aspergilloma), 51 cases(27.3%) of pulmonary cryptococosis, 6 cases (3.2%)of pulmonary mucormycosis, 3 cases(1.6%) of pulmonary histoplasmosis, 3 cases (1.6%)of pulmonary candidiasis, and 2 cases (1.1%) of pneumocystosis, while in the remaining 37 cases (19.8%) the pathogens could not be clearly classified by microscopy due to limited tissue or degeneration. Among the 88 patients with pulmonary fungal disease diagnosed by histopathology from 2011 to 2015, 35 ones (39.9%) were detected by fungal culture (including lung biopsy, intraoperative swab, blood, bronchoalveolar lavage fluid and sputum, etc.). The diagnostic results of 18 cases were completely consistent between histopathological examination and fungal culture (18/35, 51.4%), while 13 cases (13/35, 37.1%) were diagnosed by histopathology but no fungi were cultured, and in 3 cases (3/35,8.6%) the culture was positive for fungi which could not be classified clearly by histopathology. In another case the pathogen was found to be Cryptococcus histopathologically but the lavage culture grew"candida", but the patient's blood cryptococcal antigen was positive. Conclusions: Among patients with histopathological diagnosis of pulmonary fungal disease, pulmonary aspergillosis was the most common, followed by pulmonary cryptococcosis, pulmonary mucormycosis, pulmonary histoplasmosis, pulmonary candidiasis and pneumocystosis. A small number of cases could not be classified by histopathology through histochemical special staining. There was a high consistency in discovering fungal pathogens between pathological histochemical special staining and culture method, but 37% pulmonary fungal disease diagnosed by histopathology were culture negative. In practice, the role of histochemical special staining in diagnosing pulmonary fungal disease should be paid more attention.

Molecular cloning and characterization of Y-box gene (Rpybx) from Manila clam and its expression analysis in different strains under low-temperature stress

Manila clam, Ruditapes philippinarum, is an economically important marine bivalve species. Y-box proteins are members of the cold shock proteins family and highly conserved from bacteria to humans. In this study, a novel Y-box gene (Rpybx) was cloned from the Manila clam and gene expression profiling was performed on three shell color strains (white, zebra and white zebra) and two wild populations (Southern and Northern) of R. philippinarum. The complete ORF length of Rpybx is 1367 bp, encoding 253 amino acids residues. Based on the amino acid sequence analysis and phylogenetic analysis, the Rpybx gene was identified as a member of the invertebrate Y-box proteins family. Rpybx has a similar tertiary structure to human Y-box protein YB-1. The Rpybx mRNA levels were analyzed by qPCR under acute and gradually varied cold stress. Under acute low-temperature stress, the expression of Rpybx mRNA in gills and hepatopancreas was significantly increased in all selected strains and populations (P < 0.05). The Northern population showed the lowest relative expression level of Rpybx. The expressions of Rpybx were greatly upregulated in gills and hepatopancreas of different stains and populations at 5 or -2°C under gradually varied temperature stress (P < 0.05). The results shed light on the biological function of the Rpybx gene in defending against low-temperature challenge and further exploring the molecular mechanism of cold tolerance and resistance in R. philippinarum.

[Primary carcinoid of ovary: a clinicopathologic analysis of 17 cases]

Objective: To study the clinicopathologic feature, diagnostic strategy and prognostic significance of primary carcinoid of the ovary (PCOTO). Methods: A series of 17 patients previously diagnosed as PCOTO at Department of Pathology, Peking Union Medical College Hospital during the period from 2002 to 2017 were evaluated with clinical data analysis, histopathology and immunohistochemistry, and the patients were followed up and the relevant literatures were reviewed. Results: The age of patients ranged from 24 to 64 years (mean, 42 years). Fourteen patients were found a pelvic mass for a health check-up, and only 3 patients presented with pain in the lower abdomen. The left ovary was involved initially in ten patients, and the right in seven. The major axis of the tumor ranged from 2 to 14 cm. The surface of these tumors was smooth. Seven of the tumors were solid-cystic, 6 were cystic and 4 were solid. Under light microscope, 6 cases were diagnosed as strumal carcinoid, 4 cases were insular carcinoid, 4 cases were trabecular carcinoid, 3 cases were insular and trabecular mixed type carcinoid and 1 case was mucinous carcinoid. The mitotic figures were no more than 1/10 HPF.There were 11 cases complicated with other ovarian tumors, including 10 cases with teratoma, and 1 case with mucinous cystic adenoma. The paraffin-embedded tissues of all cases showed immunoreactivity for NSE and Syn, and the positive propotion of CgA was 10/17. TTF1 was positive in thyroid follicles and negative in strumal carcinoid. The positive index of Ki-67 was no more than 2%. Follow-up of 13 to 188 months showed 16 patients without recurrence and 1 patients were loss to follow-up. Conclusions: PCOTO is very rare. Most of the patients are found with a mass during health check-up in unilateral ovary and without obvious clinical symptoms. Histologically, the tumor always exists with other ovarian tumors, including teratoma and mucinous cystic adenoma, with relatively good prognosis.

[Automated Assessment for Bone Age of Left Wrist Joint in Uyghur Teenagers by Deep Learning]

OBJECTIVES

To realize the automated bone age assessment by applying deep learning to digital radiography （DR） image recognition of left wrist joint in Uyghur teenagers, and explore its practical application value in forensic medicine bone age assessment.

METHODS

The X-ray films of left wrist joint after pretreatment, which were taken from 245 male and 227 female Uyghur nationality teenagers in Uygur Autonomous Region aged from 13.0 to 19.0 years old, were chosen as subjects. And AlexNet was as a regression model of image recognition. From the total samples above, 60％ of male and female DR images of left wrist joint were selected as net train set, and 10％ of samples were selected as validation set. As test set, the rest 30％ were used to obtain the image recognition accuracy with an error range in ±1.0 and ±0.7 age respectively, compared to the real age.

RESULTS

The modelling results of deep learning algorithm showed that when the error range was in ±1.0 and ±0.7 age respectively, the accuracy of the net train set was 81.4% and 75.6% in male, and 80.5% and 74.8% in female, respectively. When the error range was in ±1.0 and ±0.7 age respectively, the accuracy of the test set was 79.5% and 71.2% in male, and 79.4% and 66.2% in female, respectively.

CONCLUSIONS

The combination of bone age research on teenagers' left wrist joint and deep learning, which has high accuracy and good feasibility, can be the research basis of bone age automatic assessment system for the rest joints of body.

Abstract PD2-08: Potential role of prolactin signaling in development and growth of the lobular subtype of breast cancer

Invasive lobular carcinoma (ILC) is the eighth most frequently diagnosed cancer in any organ, and accounts for 8-11% of breast cancer. This histological subtype is characterized by loss of E-cadherin, and favorable prognostic factors, such as low Ki67 and high rates of ER/PR-positive tumors. Only recently is the lobular subtype gaining recognition as a distinct disease, displaying a unique growth pattern, unique molecular changes in addition to loss of E-cadherin, and evidence for late recurrences and reduced response to targeted endocrine therapy. It is widely accepted that a late age at first full term birth (FFTB) increases a women's risk for breast cancer. Interestingly, several published epidemiological studies have shown that the increased risk after a late age at FFTB is preferential for the lobular subtype of breast cancer compared to the ductal subtype. We therefore hypothesized that pregnancy hormones like prolactin play an integral role in the development and progression of ILC. Interrogation of the Cancer Genome Atlas (TCGA) data revealed a high expression of milk protein genes as well as prolactin signaling molecules, specifically Stat5a and Stat5b in lobular carcinomas compared to ductal carcinomas. We developed a lactation score including 7 milk protein genes and found that in the TCGA data set ILC tumors have a significantly higher lactation score than IDC tumors. Additionally, we found that ILC cell lines express increased prolactin receptor mRNA and protein levels compared to IDC cell lines. Prolactin treatment in ILC and IDC cells reveals divergent signaling pathways - prolactin stimulates ERK activation in IDC but not ILC cells. We are currently further delineating the prolactin signaling pathways, and resulting phenotypes, comparing ILC and IDC cells. We expect these experiments to move the field forward by establishing a relationship between prolactin and lobular carcinoma.

Citation Format: Oesterreich S, Katz TA, Logan G, Levine K, Nagle A, Huo Z, Tseng GC, Rui H, Lee AV, Butler LM. Potential role of prolactin signaling in development and growth of the lobular subtype of breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD2-08.

Case-control study of a HLA-G 14-bp insertion-deletion polymorphism in women with recurrent miscarriages

Human leucocyte antigen (HLA)-G is an important molecule for maintaining an immunotolerant foetal-maternal relationship. A 14-bp insertion (+14-bp)/deletion (-14-bp) polymorphism in exon 8 of the 3' untranslated region of the HLA-G gene has been proposed to be associated with HLA-G mRNA stability and the expression of HLA-G. This might play an immunomodulatory role in human pregnancy. In this study, a total of 526 Chinese women were genotyped for the +14-bp/-14-bp polymorphism, including 137 who had recurrent miscarriages (three miscarriages: 86, four or more miscarriages: 51), 138 women who had experienced two abortions and 251 women with normal fertility as controls. The +14-bp homozygote sequence was more prominent among those with recurrent miscarriages (three or more recurrent miscarriages) in contrast to fertile control women. Significant difference was observed in the distribution of +14-bp/+14-bp genotype between controls and the recurrent abortions group with four or more abortions. A 14-bp insertion/deletion polymorphism in exon 8 has a possible role in HLA-G expression in certain cases of recurrent miscarriage. However, additional studies are needed in this regard.

Purification of lectin from larvae of the fly, Musca domestica, and in vitro anti-tumor activity in MCF-7 cells

A new lectin was purified from larvae of the fly, Musca domestica L. (Diptera: Muscidae) (MLL-2, 38 kDa) using affinity chromatography and HPLC. Anti-tumor activity of MLL-2 was demonstrated by its inhibition of proliferation of human breast cancer (MCF-7) cells in a time-and dose-dependent manner. The results of acridine orange staining indicated that MLL-2 caused apoptosis in MCF-7 cells. DNA fragmentation in MCF-7 cells has been detected by TUNEL. Flow cytometric analysis also demonstrated that MLL-2 caused dose-dependent apoptosis of MCF-7 cells through cell arrest at G2/M phase. The MLL-2 induced a sustained increase in concentration of intracellular free calcium. Western blot revealed that MLL-2 induced apoptosis in MCF-7 cells was associated with typical apoptosis proteins in the mitochondrial pathway. In addition, the caspase-3 activity in MCF-7 cells treated with MLL-2 for 48 hours was significantly increased compared to controls (407.4 ± 3.0 vs. 1749.2 ± 6.0, P <0.01). Since MLL-2 induced apoptosis in MCF-7cells the mitochondrial pathway may be the main pathway of antitumor activity.

Thermal Expansivity for sI and sII Clathrate Hydrates

Knowledge of thermal expansivity can aid in the understanding of both microscopic and macroscopic behavior of clathrate hydrates. Diffraction studies have shown that hydrate volume changes significantly (as much as 1.5% over 50 K) as a function of temperature. It has been demonstrated previously via statistical mechanics that a minor change in hydrate volume (e.g., a 1.5% change in volume or 0.5% change in lattice parameter) can lead to a major change in the predicted hydrate formation pressure (e.g., >15% at >100 MPa for methane). Because of this sensitivity, hydrate thermal expansivity measurements, for both Structures I and II with various guests, are needed help quantify volume distortions in hydrate lattices to ensure accurate hydrate phase equilibria predictions. In addition to macroscopic phase equilibria, the thermal expansion of different hydrates can give information about the interactions between the guest molecules and the host lattice. In this work, the hydrate lattice parameters for four Structure I (C2H6, CO2, 47% C2H6 + 53% CO2, and 85% CH4 + 15% CO2) and seven Structure II (C3H8, 60% CH4 + 40% C3H8, 30% C2H6 + 70% C3H8, 18% CO2 + 82% C3H8, 87.6% CH4 + 12.4% i-C4H10, 95% CH4 + 5% C5H10O, and a natural gas mixture) systems were measured as a function of temperature. The lattice parameter measurements were combined with existing literature values. Both sI and sII hydrates, with a few exceptions, had a common thermal expansivity, independent of hydrate guest. Many guest-dependent correlations for linear thermal expansivity have been proposed. However, we present two guest-independent, structure-dependent correlations for sI and sII lattices, which have been developed to express the normalized hydrate lattice parameters (and therefore volume) as a function of temperature.

Antibody response to pneumolysin and to pneumococcal capsular polysaccharide in healthy individuals and Streptococcus pneumoniae infected patients

BACKGROUND

Animal experiments have shown that antibodies against capsular polysaccharide enhance phagocytosis of pneumococcal bacteria and that antibodies against pneumolysin are anti-inflammatory and prevent pneumococcal invasion. It is not known if an antibody response to pneumolysin can be acquired from natural exposure to pneumococcal bacteria or how the concentration of pneumolysin antibody at the mucosal surface compares with that of antibodies against pneumococcal capsular polysaccharide. This study used an equal potency method to measure specific antibody concentrations against pneumolysin and pneumococcal capsular polysaccharides in order to facilitate comparative estimates of concentrations in saliva and serum. The results may provide experimental information as a basis for an improved pneumococcal vaccine strategy.

RESULTS

Healthy individuals had higher IgM and IgG antibody concentrations against capsular polysaccharide than against pneumolysin in both saliva and serum, but for IgA the converse was true. Patients with acute pneumococcal infection had significantly lower concentrations of specific IgG antibodies against both antigens than the healthy group. These patients also had significantly higher concentrations of IgM antibody against both antigens than the healthy control group.

DISCUSSION

Healthy individuals acquire a comparatively lower concentration of antibody to pneumolysin than to pneumococcal capsular polysaccharides from natural exposure to pneumococcal bacteria. Patients infected by pneumococcal bacteria have lower specific IgG antibody concentrations to both antigens than healthy individuals. These findings support the view that pneumolysin could potentially be used as a vaccine. For enhanced effectiveness, it could be used as a supplement to Pneumovax((R))II rather than as a replacement. The two acquired antibodies, i.e. to pneumolysin and to capsular polysaccharide, could then play their protective roles at different stages in the course of pneumococcal infection, and together contribute to an effective immune defence against Streptococcus pneumoniae.

Effect of Pneumovax II vaccination in high-risk individuals on specific antibody and opsonic capacity against specific and non-specific antigen

Pneumovax II vaccine has been used in many countries including the UK for adults in high-risk groups to prevent pneumococcal infections. However, its effectiveness has been a controversial issue. In this study, the specific antibody concentration and opsonic capacity of serum against specific and non-specific antigens were measured in 16 high-risk adults vaccinated with Pneumovax II. The results indicated that 38% of these individuals could make an antibody response to specific antigens post-vaccination; vaccination had a clear effect in increasing the opsonic capacity of serum against specific pneumococcal antigen (S14 serotype) in 31% of patients, but did not have any effect against non-specific antigen. The specific antibody concentration did not significantly positively correlate with the opsonic capacity of serum. Therefore, it is concluded that the protective effect of Pneumovax II vaccination against a specific serotype in high-risk individuals will only be around 30%.

Inflammatory cytokine (interleukin 6 and tumour necrosis factor alpha) release in a human whole blood system in response to Streptococcus pneumoniae serotype 14 and its capsular polysaccharide

Gram-positive bacteria, which lack lipopolysaccharide (LPS), produce a septic-shock-like condition, accompanied by release of pro-inflammatory cytokines. Various components of the bacteria may be responsible for this. We stimulated a whole blood system with heat-inactivated Streptococcus pneumoniae serotype 14 (S14) bacteria, with pneumococcal S14 capsular polysaccharide (PPS S14) and with PPS S14 coated on to latex beads, to compare interleukin 6 (IL-6) and tumour necrosis factor alpha (TNFalpha) production over a six hour period, to ascertain the contribution of PPS to the inflammatory response. This was compared with the response to LPS. After sonication of the bacteria, their PPS content was estimated by an enzyme-linked immunoabsorbent assay, to compare this with the concentration of free PPS needed to generate cytokine release. The whole bacteria elicited a much larger cytokine response than the equivalent amount of PPS alone, whereas the PPS-coated beads gave minimal response. The different cytokine responses to PPS and LPS suggest that there are differences in the receptors and/or signalling pathways for Gram-negative and Gram-positive bacteria. We conclude that the estimated amount of PPS in the bacteria is not enough to account for the large cytokine response we observed. Since PPS could not be shown to contribute significantly to cytokine induction, specific antibodies to PPS would not play any significant role in combating cytokine release associated with pneumococcal infection and possible septic shock. This needs to be considered in production of future vaccines.

Computerized analysis of multiple-mammographic views: potential usefulness of special view mammograms in computer-aided diagnosis

PURPOSE

To investigate the potential usefulness of special view mammograms in the computer-aided diagnosis of mammographic breast lesions.

MATERIALS AND METHODS

Previously, we developed a computerized method for the classification of mammographic mass lesions on standard-view mammograms, i.e., mediolateral oblique (MLO) view and/or cranial caudal (CC) views. In this study, we evaluate the performance of our computerized classification method on an independent database consisting of 70 cases (33 malignant and 37 benign cases), each having CC, MLO, and special view mammograms (spot compression or spot compression magnification views). The mass lesion identified in each of the three mammographic views was analyzed using our previously developed and trained computerized classification method. Performance in the task of distinguishing between malignant and benign lesions was evaluated using receiver operating characteristic analysis. On this independent database, we compared the performance of individual computer-extracted mammographic features, as well as the computer-estimated likelihood of malignancy, for the standard and special views.

RESULTS

Computerized analysis of special view mammograms alone in the task of distinguishing between malignant and benign lesions yielded an Az of 0.95, which is significantly higher (p < 0.005) than that obtained from the MLO and CC views (Az values of 0.78 and 0.75, respectively). Use of only the special views correctly classified 19 of 33 benign cases (a specificity of 58%) at 100% sensitivity, whereas use of the CC and MLO views alone correctly classified 4 and 8 of 33 benign cases (specificities of 12% and 24%, respectively). In addition, we found that the average computer output of the three views (Az of 0.95) yielded a significantly better performance than did the maximum computer output from the mammographic views.

CONCLUSIONS

Computerized analysis of special view mammograms provides an improved prediction of the benign versus malignant status of mammographic mass lesions.

[The influence of resuscitation with solutions containing different concentrations of sodium on the homeostasis of burn patients during the early postburn stage]

OBJECTIVE

To investigate the influence of resuscitation with solutions containing different concentrations of sodium on the homeostasis of burn patients during the early postburn stage.

METHODS

Thirty-five cases of burn patients inflicted with 50% approximately 100% of TBSA including 20% approximately 88% of 3rd degree burn were enrolled in the study. All the patients studied were divided into A[(Na+) = 174 mmol/L] and B [(Na+) = 130 mmol/L] groups according to different concentrations of sodium in the infusion solution. The input of the fluid, plasma crystal osmotic pressure, plasma ratio of albumin to globulin, urine output and pH value and anasarcous degree were observed during 1 to 5 postburn days (PBDs).

RESULTS

The infusion fluid amount per hour in A group was 20 approximately 30 ml less than that in B group within 3 PBDs. The infused sodium amount in A group was more than that in B group within 5 PBDs. The FENa in A group was in normal range within 5 PBDs, while that in B group was lower than normal. This might be related to different infusion amounts of water and sodium.

CONCLUSION

The homeostasis of burn patients could be significantly affected by the water load and the sodium concentration in the resuscitation solution during early postburn stage.

Computerized classification of benign and malignant masses on digitized mammograms: a study of robustness

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate the robustness of a computerized method developed for the classification of benign and malignant masses with respect to variations in both case mix and film digitization.

MATERIALS AND METHODS

The classification method included automated segmentation of mass regions, automated feature-extraction, and automated lesion characterization. The method was evaluated independently with a 110-case database consisting of 50 malignant and 60 benign cases. Mammograms were digitized twice with two different digitizers (Konica and Lumisys). Performance of the method in differentiating benign from malignant masses was evaluated with receiver operating characteristic (ROC) analysis. Effects of variations in both case mix and film digitization on performance of the method also were assessed.

RESULTS

Categorization of lesions as malignant or benign with an artificial neural network (or a hybrid) classifier achieved an area under the ROC curve, Az, value of 0.90 (0.94 for the hybrid) on the previous training database in a round-robin evaluation and Az values of 0.82 (0.81) and 0.81 (0.82) on the independent database for the Konica and Lumisys formats, respectively. These differences, however, were not statistically significant (P > .10).

CONCLUSION

The computerized method for the classification of lesions on mammograms was robust with respect to variations in case mix and film digitization.

Computerized analysis of mammographic parenchymal patterns for breast cancer risk assessment: feature selection

Our purpose in this study was to identify computer-extracted, mammographic parenchymal patterns that are associated with breast cancer risk. We extracted 14 features from the central breast region on digitized mammograms to characterize the mammographic parenchymal patterns of women at different risk levels. Two different approaches were employed to relate these mammographic features to breast cancer risk. In one approach, the features were used to distinguish mammographic patterns seen in low-risk women from those who inherited a mutated form of the BRCA1/BRCA2 gene, which confers a very high risk of developing breast cancer. In another approach, the features were related to risk as determined from existing clinical models (Gail and Claus models), which use well-known epidemiological factors such as a woman's age, her family history of breast cancer, reproductive history, etc. Stepwise linear discriminant analysis was employed to identify features that were useful in differentiating between "low-risk" women and BRCA1/BRCA2-mutation carriers. Stepwise linear regression analysis was employed to identify useful features in predicting the risk, as estimated from the Gail and Claus models. Similar computer-extracted mammographic features were identified in the two approaches. Results show that women at high risk tend to have dense breasts and their mammographic patterns tend to be coarse and low in contrast.

Computerized analysis of lesions in US images of the breast

RATIONALE AND OBJECTIVES

Breast sonography is not routinely used to distinguish benign from malignant solid masses because of considerable overlap in their sonographic appearances. The purpose of this study was to investigate the computerized analyses of breast lesions in ultrasonographic (US) images in order to ultimately aid in the task of discriminating between malignant and benign lesions.

MATERIALS AND METHODS

Features related to lesion margin, shape, homogeneity (texture), and posterior acoustic attenuation pattern in US images of the breast were extracted and calculated. The study database contained 184 digitized US images from 58 patients with 78 lesions. Benign lesions were confirmed at biopsy or cyst aspiration or with image interpretation alone; malignant lesions were confirmed at biopsy. Performance of the various individual features and output from linear discriminant analysis in distinguishing benign from malignant lesions was studied by using receiver operating characteristic (ROC) analysis.

RESULTS

At ROC analysis, the feature characterizing the margin yielded Az values (area under the ROC curve) of 0.85 and 0.75 in distinguishing between benign and malignant lesions for the entire database and for an "equivocal" database, respectively. The equivocal database contained lesions that had been proved to be benign or malignant at cyst aspiration or biopsy. Linear discriminant analysis round-robin runs yielded Az values of 0.94 and 0.87 in distinguishing benign from malignant lesions for the entire database and for the equivocal database, respectively.

CONCLUSION

Computerized analysis of US images has the potential to increase the specificity of breast sonography.

Effect of dominant features on neural network performance in the classification of mammographic lesions

Two different classifiers, an artificial neural network (ANN) and a hybrid system (one step rule-based method followed by an artificial neural network) have been investigated to merge computer-extracted features in the task of differentiating between malignant and benign masses. A database consisting of 65 cases (38 malignant and 26 benign) was used in the study. A total of four computer-extracted features--spiculation, margin sharpness and two density-related measures--was used to characterize these masses. Results from our previous study showed that the hybrid system performed better than the ANN classifier. In our current study, to understand the difference between the two classifiers, we investigated their learning and decision-making processes by studying the relationships between the input features and the outputs. A correlation study showed that the outputs from the ANN-alone method correlated strongly with one of the input features (spiculation), yielding a correlation coefficient of 0.91, whereas the correlation coefficients (absolute value) for the other features ranged from 0.19 to 0.40. This strong correlation between the ANN output and spiculation measure indicates that the learning and decision-making processes of the ANN-alone method were dominated by the spiculation measure. Three-dimensional plots of the computer output as functions of the input features demonstrate that the ANN-alone method did not learn as effectively as the hybrid system in differentiating non-spiculated malignant masses from benign masses, thus resulting in an inferior performance at the high sensitivity levels. We found that with a limited database it is detrimental for an ANN to learn the significance of other features in the presence of a dominant feature. The hybrid system, which initially applied a rule concerning the value of the spiculation measure prior to employing an ANN, prevents over-learning from the dominant feature and performed better than the ANN-alone method in merging the computer-extracted features into a correct diagnosis regarding the malignancy of the masses.

Automated computerized classification of malignant and benign masses on digitized mammograms

RATIONALE AND OBJECTIVES

To develop a method for differentiating malignant from benign masses in which a computer automatically extracts lesion features and merges them into an estimated likelihood of malignancy.

MATERIALS AND METHODS

Ninety-five mammograms depicting masses in 65 patients were digitized. Various features related to the margin and density of each mass were extracted automatically from the neighborhoods of the computer-identified mass regions. Selected features were merged into an estimated likelihood of malignancy by, using three different automated classifiers. The performance of the three classifiers in distinguishing between benign and malignant masses was evaluated by receiver operating characteristic analysis and compared with the performance of an experienced mammographer and that of five less experienced mammographers.

RESULTS

Our computer classification scheme yielded an area under the receiver operating characteristic curve (Az) value of 0.94, which was similar to that for an experienced mammographer (Az = 0.91) and was statistically significantly higher than the average performance of the radiologists with less mammographic experience (Az = 0.81) (P = .013). With the database used, the computer scheme achieved, at 100% sensitivity, a positive predictive value of 83%, which was 12% higher than that for the performance of the experienced mammographer and 21% higher than that for the average performance of the less experienced mammographers (P < .0001).

CONCLUSION

Automated computerized classification schemes may be useful in helping radiologists distinguish between benign and malignant masses and thus reducing the number of unnecessary biopsies.

A glycoprotein pneumococcal conjugate vaccine primes for antibody responses to a pneumococcal polysaccharide vaccine in Gambian children

BACKGROUND

Streptococcus pneumoniae is a major cause of acute respiratory infections and acute bacterial meningitis in children. Pneumococcal polysaccharide vaccines are poorly immunogenic in this highly vulnerable group, but protein polysaccharide conjugate vaccines are likely to be more effective.

OBJECTIVES

To determine whether immunization of infants with a pneumococcal conjugate vaccine induces immunologic memory.

METHODS

Eighty-four Gambian children, who had been vaccinated previously with two or three doses of a pentavalent pneumococcal conjugate vaccine (CRM197) or with a Haemophilus influenzae type b (Hib) conjugate vaccine were immunized when approximately 2 years old with a 23-valent pneumococcal polysaccharide vaccine, and a blood sample was obtained 10 days later. Pneumococcal antibody titers in prevaccination and postvaccination sera were measured by enzyme-linked immunosorbent assay and by an opsonophagocytic assay.

RESULTS

On revaccination with a pneumococcal polysaccharide vaccine, children who had previously received pneumococcal conjugate vaccine had higher antibody concentrations to each of the five polysaccharide components of the conjugate vaccine than did control children. For type 6B polysaccharide, which is poorly immunogenic in young children, postvaccination antibody concentrations were 0.37, 27.6 and 50.9 microg/ml in children who had received no previous pneumococcal immunization or two or three doses of conjugate vaccine, respectively. Type 14 antibodies produced after revaccination were of high avidity and had opsonic activity.

CONCLUSION

Vaccination of young infants with two or three doses of a pneumococcal conjugate vaccine primes the immune system to respond strongly and rapidly on subsequent exposure to pneumococcal polysaccharide.

The glial glutamate transporter in hyperammonemia and hepatic encephalopathy: relation to energy metabolism and glutamatergic neurotransmission

Abnormalities in glutamate metabolism and glutamatergic neurotransmission appear to play a major role in the pathogenesis of hyperammonemia and hepatic encephalopathy. Astrocytes may be involved in these derangements as ammonia has been shown to impair the ability of these cells to take up glutamate. This study presents a northern blot analysis of the GLT-1 glutamate transporter in hyperammonemic rats, and in rats with thioacetamide-induced acute liver failure. Our findings demonstrate a downregulation of GLT-1 mRNA in both conditions. This article examines the potential impact of deficits in glutamate uptake on energy metabolism and glutamatergic neurotransmission in the context of abnormalities in glial-neuronal interactions. We propose that an ammonia-induced abnormality in astroglial glutamate uptake constitutes a critical aspect in the pathogenesis of hepatic encephalopathy and other hyperammonemic conditions.

Severe pneumococcal disease and temporary splenic dysfunction

We report a patient presenting with pneumonia in whom temporary splenic dysfunction was diagnosed by counting pitted red blood cells. This under-recognised condition caused a transient immunosuppression which may have had serious implications for our patient's recovery.

Analysis of spiculation in the computerized classification of mammographic masses

Spiculation is a primary sign of malignancy for masses detected by mammography. In this study, we developed a technique that analyzes patterns and quantifies the degree of spiculation present. Our current approach involves (1) automatic lesion extraction using region growing and (2) feature extraction using radial edge-gradient analysis. Two spiculation measures are obtained from an analysis of radial edge gradients. These measures are evaluated in four different neighborhoods about the extracted mammographic mass. The performance of each of the two measures of spiculation was tested on a database of 95 mammographic masses using ROC analysis that evaluates their individual ability to determine the likelihood of malignancy of a mass. The dependence of the performance of these measures on the choice of neighborhood was analyzed. We have found that it is only necessary to accurately extract an approximate outline of a mass lesion for the purposes of this analysis since the choice of a neighborhood that accommodates the thin spicules at the margin allows for the assessment of margin spiculation with the radial edge-gradient analysis technique. The two measures performed at their highest level when the surrounding periphery of the extracted region is used for feature extraction, yielding Az values of 0.83 and 0.85, respectively, for the determination of malignancy. These are similar to that achieved when a radiologist's ratings of spiculation (Az = 0.85) are used alone. The maximum value of one of the two spiculation measures (FWHM) from the four neighborhoods yielded an Az of 0.88 in the classification of mammographic mass lesions.

[Experimental study of antiinfection effect of topical "moist ointment" in burn wound infection]

A controversy on the therapeutic effect of topical "moist ointment" in burns has been noticed recently. An experimental study is designed for the evaluation of its antibacterial and antiinfection effect. A 20% fullthickness burn wound is produced on SD rat back, and they are seeded with 10(9) CFU of Pseudomonas aeruginosa ATCC-27853. "Moist ointment", cream base, 1% silver sulfadiazine (Ag-SD) cream or 1.2% silver norfloxacin (Ag-FLX) cream is topically applied to the burn wounds at various time interval of 10 min, 8h, 24h, and 48h, after the inoculation of Pseudomonas aeruginosa. Topical therapy lasted for 48h, with dressing change once a day but twice a day for "moist ointment" therapy only. Bacterial counts of subeschar tissue and heart blood culture, and histopathologic study of the wounds are made as laboratory criteria. A modified agar well diffusion (AWD) test is performed as a bacterial inhibitory study using Pseudomonas aeruginosa ATCC-27853, E. coli ATCC-25922, or Staphylococcus aureus ATCC-25923. Results of the study show that Ag-FLX cream has a strong antibacterial effect and Ag-SD cream a moderate effect. However, "moist ointment" and cream base do not show antibacterial effect. Bacterial counts of subeschar tissue and histopathologic study of the infected burn wounds show that more than 70% of the animals in the "moist ointment" group have invasive wound infection, and the incidence of septicemia with Pseudomonas aeruginosa is 50% as determined by blood cultures. The above mentioned results indicate that "moist ointment" has no antibacterial and anti-infection effect.

[Multi-locus DNA fingerprints using oligonucleotide probe (CAC)5/(GTG)5 in the Chinese population]

In order to test the practical applicability of oligonucleotide fingerprinting in China we have investigated unrelated individuals, family members and a pair of twins from the Beijing area using the probe (CAC)5/(GTG)5. Except for the monozygotic twins highly variable banding patterns were demonstrated as expected for the randomly selected individuals but also for the relatives. On the basis of an initial survey of 50 unrelated individuals the calculated probability for obtaining by chance two identical multilocus patterns is very small (less than 1.93 x 10(-13). Therefore it seems reasonable to conclude that like in caucasians, (CAC)5/(GTG)5 fingerprints are completely individual-specific also in this population. Therefore they have already been used successfully for identification purposes and paternity tests in many actual cases.