Novel machine-learning analysis of SARS-CoV-2 infection in a subclinical nonhuman primate model using radiomics and blood biomarkers

Detection of the physiological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is challenging in the absence of overt clinical signs but remains necessary to understand a full subclinical disease spectrum. In this study, our objective was to use radiomics (from computed tomography images) and blood biomarkers to predict SARS-CoV-2 infection in a nonhuman primate model (NHP) with inapparent clinical disease. To accomplish this aim, we built machine-learning models to predict SARS-CoV-2 infection in a NHP model of subclinical disease using baseline-normalized radiomic and blood sample analyses data from SARS-CoV-2-exposed and control (mock-exposed) crab-eating macaques. We applied a novel adaptation of the minimum redundancy maximum relevance (mRMR) feature-selection technique, called mRMR-permute, for statistically-thresholded and unbiased feature selection. Through performance comparison of eight machine-learning models trained on 14 feature sets, we demonstrated that a logistic regression model trained on the mRMR-permute feature set can predict SARS-CoV-2 infection with very high accuracy. Eighty-nine percent of mRMR-permute selected features had strong and significant class effects. Through this work, we identified a key set of radiomic and blood biomarkers that can be used to predict infection status even in the absence of clinical signs. Furthermore, we proposed and demonstrated the utility of a novel feature-selection technique called mRMR-permute. This work lays the foundation for the prediction and classification of SARS-CoV-2 disease severity.

A computational study of the thortveitite structure of zinc pyrovanadate, Zn2V2O7, under pressure

We performed a pressure-driven study of zinc pyrovanadate, Zn₂V₂O₇, using the first-principles approach under the framework of density functional theory (DFT). Zn₂V₂O₇ crystalizes in a monoclinic (α-phase) structure with the space group C2/c at ambient pressure. In comparison with the ambient phase, there are four different high-pressure phases, namely β, γ, κ and δ, found at 0.7, 3.8, 4.8 and 5.3 GPa, respectively. The detailed crystallographic analysis as well as their structures is consistent with the theory and experiment reported in the literature. All phases including the ambient phase are mechanically stable, elastically anisotropic and malleable. The compressibility of the studied pyrovanadate is higher than that of the other meta- and pyrovanadates. The energy dispersion of these studied phases reveals that they are indirect band gap semiconductors with wide band gap energies. The band gap energies follow a reduced trend with pressure except the κ-phase. The effective masses for all of these studied phases were computed from their corresponding band structures. The values of energy gaps obtained from the band structures are almost similar to the optical band gap obtained from the optical absorption spectra, as estimated by the Wood-Tauc theory.

Toward the determination of sensitive and reliable whole-lung computed tomography features for robust standard radiomics and delta-radiomics analysis in a nonhuman primate model of coronavirus disease 2019

Purpose

We propose a method to identify sensitive and reliable whole-lung radiomic features from computed tomography (CT) images in a nonhuman primate model of coronavirus disease 2019 (COVID-19). Criteria used for feature selection in this method may improve the performance and robustness of predictive models.

Approach

Fourteen crab-eating macaques were assigned to two experimental groups and exposed to either severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or a mock inoculum. High-resolution CT scans were acquired before exposure and on several post-exposure days. Lung volumes were segmented using a deep-learning methodology, and radiomic features were extracted from the original image. The reliability of each feature was assessed by the intraclass correlation coefficient (ICC) using the mock-exposed group data. The sensitivity of each feature was assessed using the virus-exposed group data by defining a factor R that estimates the excess of variation above the maximum normal variation computed in the mock-exposed group. R and ICC were used to rank features and identify non-sensitive and unstable features.

Results

Out of 111 radiomic features, 43% had excellent reliability ( ICC > 0.90 ), and 55% had either good ( ICC > 0.75 ) or moderate ( ICC > 0.50 ) reliability. Nineteen features were not sensitive to the radiological manifestations of SARS-CoV-2 exposure. The sensitivity of features showed patterns that suggested a correlation with the radiological manifestations.

Conclusions

Features were quantified and ranked based on their sensitivity and reliability. Features to be excluded to create more robust models were identified. Applicability to similar viral pneumonia studies is also possible.

Rooting behaviour and soil properties in different bamboo species of Western Himalayan Foothills, India

Due to extensive root system, connected rhizome bamboos are considered suitable for improving soil properties within a short period, though most of the claims are anecdotal and need to be supported with quantified data. The study evaluates seven bamboo species viz., Bambusa balcooa, Bambusa bambos, Bambusa vulgaris, Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii and Dendrocalamus strictus for their rooting pattern and impact on soil health properties. Coarse and fine root intensity was maximum in B. vulgaris. Coarse root biomass ranged from 0.6 kg m⁻³ in B. nutans to 2.0 kg m⁻³ in B. vulgaris and B. bambos. Fine root biomass ranged from 1.1 kg m⁻³ in B. nutans to 4.5 kg m⁻³ in D. hamiltonii. Contribution of fine roots in terms of intensity and biomass was much higher than coarse roots. Fine root biomass showed declining trend with increase in soil depth in all the species. During sixth year, the litter fall ranged from 8.1 Mg ha⁻¹ in D. stocksii to 12.4 Mg ha⁻¹ in D. hamiltonii. Among soil physical properties significant improvement were recorded in hydraulic conductivity, water stable aggregates and mean weight diameter. Soil pH, organic carbon and available phosphorus under different species did not reveal any significant changes, while significant reduction was observed in total nitrogen and potassium. Significant positive correlation was observed between WSA and iron content. Soil microbial population and enzyme activities were higher in control plot. Considering root distribution, biomass, soil hydraulic conductivity and water stable aggregates, B. bambos, B. vulgaris and D. hamiltonii are recommended for rehabilitation of degraded lands prone to soil erosion.

A225 AGE OF DIAGNOSIS DOES NOT IMPACT LIKELIHOOD OF EXPERIENCING POOR IBD-RELATED OUTCOMES

Aims

The relationship between the age of diagnosis of inflammatory bowel disease (IBD) and adverse disease outcomes has not been well defined. This study aims to determine whether an early age of diagnosis is associated with worse disease outcomes.

Methods

This was a retrospective study of IBD patients seen at McMaster University Medical Centre, in Hamilton, ON, Canada from 2012 to 2018. Patients were classified as having poor outcomes if they had any of the following: (1) two or more bowel resections since diagnosis; (2) two or more hospitalizations for disease exacerbation since diagnosis; or (3) more than three months of corticosteroid use within 24 months of diagnosis. Prior knowledge in combination with forward selection was used to develop a multivariate logistic regression model and identify predictors of poor IBD outcomes. The variables used in the forward selection model included age at diagnosis (less than vs. greater than 25), smoking status, sex, disease duration, and type of IBD.

Results

A total of 617 IBD patients were included in the analysis, of which 356 (57.7%) had Crohn’s disease, 234 (37.9%) had ulcerative colitis, and 27 (4.4%) had IBD-U. The median age at diagnosis was 25 (interquartile range (IQR) 17–37). Median disease duration was 16 years (IQR 11–24). A univariate regression analysis indicated that the odds ratio (OR) of poor outcomes was found to be 0.55 (0.38 - 0.79) for those ≥25 years of age compared to to those <25. In the multivariate regression analysis (Table 1), all of disease duration, smoking status, and IBD type were found to have a significant association with having poor outcomes. Each year of disease duration was associated with an increase in odds of poor outcomes (OR 1.06, 95% CI 1.03–1.09). Active smokers had increased odds of poor outcomes compared to past or never smokers (OR 5.01, 95% CI 1.71–14.68). Patients with ulcerative colitis were less likely to experience poor outcomes compared to Crohn’s disease patients (OR 0.38, 95% CI 0.24–0.57). Age of diagnosis was no longer found to have a significant association with poor outcomes, once adjusted for other co-variates (OR 0.74, 95% CI 0.47–1.15).

Conclusions

Age of diagnosis was not found to have a relationship with occurrence of poor IBD outcomes, after adjustment for co-variates. However, patients with increased disease duration, active smoking status, and Crohn’s disease (compared to UC) were found to have increased odds of poor IBD-related outcomes.

Funding Agencies

None

External beam radiotherapy versus brachytherapy in the management of malignant oesophageal dysphagia: a retrospective study

PURPOSE

Dysphagia is a prominent symptom of oesophageal cancer which may be palliated by stent, external beam radiation (EBRT) or intraluminal brachytherapy (ILBT). Brachytherapy is not widely practised in the UK. The aim of this study was to compare the efficacy of ILBT and EBRT in relieving malignant dysphagia.

METHODS

The radiotherapy database at Northampton Cancer Centre (NCC) was used to identify patients who underwent ILBT or EBRT for malignant dysphagia between 1.1.2008 and 31.3 2010. Data was collected on patient demographics, tumour characteristics, treatment received and dysphagia score pre- and post- treatment. Serial assessment of dysphagia was used to determine the duration of symptomatic improvement. EBRT involved 20-30 Gy in 5-10 fractions. Brachytherapy applicator placement was done by an experienced endoscopist at the high dose rate (HDR) suite and a single treatment dose of 12 Gy was prescribed at 1 cm depth. Oesophageal dilation was performed prior to brachytherapy treatment if needed.

RESULTS

44 patients were included in this study (EBRT: 21; ILBT: 23). Patient characteristics were well balanced between the two groups. The average dysphagia scores in the EBRT group prior to treatment were 3, and at 4, 8 and 16 weeks following treatment they were 3.4, 2.4, 2.1 and 2.1, respectively. The corresponding dysphagia scores in the ILBT group were 3.5 before treatment and 2.2, 2.1 and 2.3 following treatment, respectively. There was significant improvement in dysphagia in both groups at 4 weeks (p<0.0001), and the benefit was sustained after 8 and 16 weeks. No major complications were reported from either EBRT or oesophageal brachytherapy.

CONCLUSION

ILBT is an effective alternative to multifractionated EBRT for palliation of malignant dysphagia providing a convenient one-stop treatment for patients who live a long distance from their cancer centre. Our model of performing the endoscopically guided procedure in the brachytherapy unit is comparable in cost to fractionated EBRT and can be adopted by other centres.

Pancreatic cancer within a UK cancer network with special emphasis on locally advanced non-metastatic pancreatic cancer

AIMS

The outcome of patients with pancreatic cancer from an unselected population within a UK region has not previously been reported. We undertook a review of pancreatic cancer in southeast Wales, with an emphasis on locally advanced non-metastatic pancreatic cancer (LANPC) in an attempt to define a subgroup of patients who would probably benefit from multi-modality treatment.

MATERIALS AND METHODS

Case notes of patients referred to Velindre Hospital between 1 January 2002 and 31 December 2005 were reviewed. Data on patient demographics, tumour characteristics, treatment, treatment response and overall survival were collected. The Log-rank test was used to compare survival between groups and Cox regression was used to evaluate whether age, gender, tumour site and treatment response correlated with overall survival in LANPC.

RESULTS

Of the 354 referrals (complete data on 315 patients), 93% were inoperable and 51% of inoperable patients received active treatment (149/294). One hundred and fourteen patients out of 315 (36%) had LANPC and 72/114 (64%) were fit for active treatment, including chemotherapy (n=66) and chemoradiotherapy (CRT) (n=6). The median survival of patients with LANPC was 7.4 months (95% confidence interval 6.4-8.5). Survival for patients receiving chemotherapy, CRT and no treatment was 9.2 (7.5-10.7), 12.6 (6.1-19.1) and 4.5 (3.7-5.3) months, respectively. Overall survival of patients who had non-progressive disease after initial chemotherapy was significantly better than those who progressed (11.8 vs 6.6 months, P=0.01). Of the 180/315 (57%) patients presenting with metastatic disease, 43% received active treatment. Overall survival of metastatic patients was 2.8 months (2.3-3.2 months); for those receiving active treatment, this was 5.6 months (5.1-6.1 months) and for those receiving active supportive care 1.8 months (1.6-2.0 months).

CONCLUSIONS

In this UK network, about half of the patients received active treatment. Although the overall outcome was poor, that of treated patients was comparable with published studies. For patients with LANPC, the initial response or disease stabilisation on chemotherapy defined a subset of patients who had better outcome. The role of CRT over and above chemotherapy needs to be defined through trials that should include a neoadjuvant 'chemotherapy-only' phase to select out patients who benefit from multi-modality treatment.

Gender sensitization among health providers and communities through transformative learning tools: experiences from Karachi, Pakistan

CONTEXT

Pakistan lags far behind most developing countries in women's health and gender equity. Appropriateness of health care services vis-a-vis the gender specific cultural norms that influence clients' needs are not very visible and are more difficult to monitor. Programs and services need to be sensitively designed to facilitate women's access to physical and social needs. This paper narrates the experience of working with health providers from public and private sectors, community, local government representatives and community-based organizations. Through transformative learning, this endeavour focused on initiating a process of sensitization on gender related health issues for women.

APPROACH

The initiative was primarily based on the use of the following two standardized tools: 'Health Workers for Change' for working with health providers and 'Initiating Women Empowerment for Health' for interacting with the community. Both tools focus primarily on women's health and social issues affecting their health status. The research methodology used was predominantly qualitative, using focus group discussions, participatory rural appraisal and interactive workshops.

IMPLICATIONS

This approach endeavours to sensitize the health service providers to the health needs of female clients and encourages behavioural changes. Simultaneously, it creates an opportunity to raise awareness among women and the community in general regarding appropriate health-seeking behaviour and the timely use of health services. The information collected is evidence for policy makers regarding the gender-based problems faced by women who are seeking health care and it suggests how to overcome these problems.

An audit of outcome of pancreatic cancer in a UK region: Does chemoradiation add to systemic chemotherapy for locally advanced disease

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Background: The benefit of adding radiotherapy to chemotherapy (CT) in patients with locally advanced non-metastatic pancreatic cancer (LANPC) is uncertain with chemoradiation (CRT) being the treatment of choice in the USA and CT alone more common in the UK. To establish the outcome of LANPC treated with CT alone we undertook a review of outcomes of all patients with LANPC referred to a single UK Cancer Network (South East Wales, population 1.5 million) over a 4 year period. Methods: Case notes, radiology and histology reports of patients with LANPC referred to Velindre Cancer Centre between 1.1.2002 and 31.12.2005 were reviewed. Patient and tumour characteristics, treatment type and duration, response to treatment and overall survival were collected. The primary end-point of the study was overall survival. Log-rank was used to compare survival between groups, and Cox regression analysis model was used to evaluate whether age, sex, tumour site and treatment response correlated with overall survival. Results: 357 patients were identified with pancreatic cancer. 116/357 (32.5%) patients had LANPC of which 74/116 (64%) were fit for active treatment. Treatment included primary gemcitabine based CT (n= 68) and CRT (n=6). For patients receiving primary CT median duration of treatment was 3.2 months. The median survival of all patients with LANPC was 7.7 months (95% CI 6.7–8.7). Survival for patients receiving primary CT, CRT and no treatment were 10 (8.5–11.3) months, 10.3 (0–20.7) months and 4.6 (3.8–5.4) months respectively. Survival of 4 patients who received neoadjuvant CT prior to CRT was 12.9 (6.8–19) months. 32 patients (47%) progressed on CT. OS of patients with non-progressive disease was significantly better than those who progressed (12.1 v 6.7 months, p=0.039). Conclusions: In this UK Network, only a small proportion of patients are eligible for active treatment. The outcome of patients treated with CT alone is comparable to published series of CRT. There is an urgent need for a randomised trial to define the additional role of CRT over and above Gemcitabine-based chemotherapy and such trials should include a neo-adjuvant ‘chemotherapy-only’ phase to select out patients most likely to benefit from multi-modality treatment.

No significant financial relationships to disclose.

Capecitabine therapy in advanced gall bladder cancer: A phase II study

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Background: Thymidine phosphorylase (TP) activity is found at higher levels in gall bladder cancer (GBC) tissues than in adjacent healthy tissues. GBC is relatively sensitive to 5-FU. TP activated capecitabine (CAP) mimics the continuous infusion of 5-FU. In view of drug potentiality this present study was initiated. Our aim was to evaluate the therapeutic efficacy and safety of CAP in previously untreated GBC patients (Pts). Methods: It was an open-labelled, single-centred, non-randomised and prospective study. Outcome measures were response rate and type of response for efficacy measurement and safety was measured by adverse events & laboratory blood values (LBV). All LBV were within reference range at baseline. The patients had no prior chemo/ radio therapy or a family history of malignancy; adenocarcinoma (stage III–IV); age 40–70 yrs; male/female: 16/ 30; KPS ≥ 70%. 46 pts were treated with 306 cycles (min 3–max 12) of CAP at a dose of 2500 mg/day in two divided doses from day 1–14 followed by 1-week rest. Results: Median age was 50 yrs. Hand foot syndrome occurred in 17.39% pts, diarrhoea (grade 3 & 4) 21.75% and both 15.21%, all toxicities were manageable. Mean LBV before and after CAP therapy were hemoglobin: 11.38–0.35 g/dl (95% CI, 10.66–2.10); total count of WBC: 9,260–580/mm3 (95% CI, 8,680–9,840); platelet count: 251,000–2,000/mm3 (95% CI, 227,000–275,000) and serum bilirubin: 1.17–0.33 mg/dl (95% CI, 0.5–1.84). The LBV between baseline and after CAP therapy were not statistically significant. Partial response was found in 12 pts (26.08%), stable disease in 26 pts (56.21%), and progressive disease in 8 pts (17.39%). Mean KPS value after therapy was 76% (95% CI, 69–84). Conclusion: This clinical experience indicates that CAP is a convenient choice in phase II chemo naïve GBC pts not adversely affecting haematological values.

No significant financial relationships to disclose.

Resistance to malarial infection is achieved by the cooperation of NK1.1(+) and NK1.1(-) subsets of intermediate TCR cells which are constituents of innate immunity

We previously reported that the major expanding lymphocytes were intermediate TCR (TCR(int)) cells (mainly NK1.1(-)) during malarial infection in mice. Cell transfer experiments of TCR(int) cells indicated that these T cells mediated resistance to malaria. However, TCR(int) cells always contain NK1.1(+)TCR(int) cells (i.e., NKT cells) and controversial results (NKT cells were effective or not for resistance to malaria) have been reported by different investigators. In this study, we used CD1d((-/-)) mice, which almost completely lack NKT cells in the liver and other immune organs. Parasitemia was prolonged in the blood of CD1d((-/-)) mice and the expansion of lymphocytes in the liver of these mice was more prominent after an injection of Plasmodium yoelii-infected erythrocytes. However, these mice finally recovered from malaria. In contrast to B6 mice, CD4(-)8(-) NKT cells as well as NK1.1(-)CD3(int) cells expanded in CD1d((-/-)) mice after malarial infection, instead of CD4(+) (and CD8(+)) NKT cells. These newly generated CD4(-)8(-)NKT cells in CD1d((-/-)) mice did not use an invariant chain of Valpha14Jalpha281 for TCRalpha. Other evidence was that severe thymic atrophy and autoantibody production were accompanied by malarial infection, irrespective of the mice used. These results suggest that both NK1.1(-) and NK1.1(+) subsets of TCR(int) cells (i.e., constituents of innate immunity) are associated with resistance to malaria and that an autoimmune-like state is induced during malarial infection.

Spontaneous down-regulation of Fas-associated phosphatase-1 may contribute to excessive apoptosis in myelodysplastic marrows

In this study, we examined the role of Fas-signaling in the apoptotic pathway in myelodysplastic syndromes (MDS). Ficoll-separated mononuclear cells from 18 bone marrow aspirate specimens obtained from 17 MDS patients, 4 normal healthy donors, and 3 acute myeloid leukemia patients transformed from MDS (t-AML) were studied for mRNA expression of Fas-L, Fas, and the effectors of their signaling, Caspase 1 and Caspase 3, using reverse transcriptase polymerase chain reaction. Fas-L, Fas, and Caspase 1 were detectable in all of the samples in the three groups. Caspase 3 was detectable both in MDS and t-AML specimens but was negligible in normal cells. The apoptotic index (AI%) determined by in situ end labeling of fragmented DNA in 4-hour cultures of mononuclear cells was significantly higher in MDS cells compared to normal or t-AML cells (mean +/- SEM: 2.3% +/- 0.4% in MDS, n = 10 vs. 0.6% +/- 0.2%, n = 4, P = 0.014 in normal cells, and 0.2% +/- 0.2%, n = 3, P = 0.007 in t-AML cells). Treatment of MDS cells with anti-Fas-L antibody suppressed apoptosis (AI%: 2.1% +/- 0.6% in untreated vs. 1.37% +/- 0.5% in treated, n = 6, P = 0.02), indicating functional participation of Fas-signaling in MDS. Further, it was found that Fas-L, Fas, and Caspase 1 mRNA expression remained unchanged in 4 hours. Caspase 3 expression appeared in normal cells after 4 hours and was present at both 0 and 4 hours in MDS and t-AML cells. In contrast to persistent expression in normal and t-AML cells, cells from the 5 MDS patients studied consistently showed significantly lowered or undetectable expression of a negative regulator of Fas, called Fas-associated phosphatase-1 (Fap-1) after 4 hours. Thus, the high AI% in MDS corresponds to a rapid decline in Fap-1. Furthermore, in tumor necrosis factor alpha (TNF-alpha) treated HL60 promyelocytic cells, a definite periodicity in the expression of different mRNAs was observed with upregulation of TNF-alpha itself at 30 minutes, increased expression of Fas and the appearance of Fas-L after 2 hours, and a decrease in Fap-1 expression after 8 hours. These results suggest that TNF-alpha not only induces the effectors of Fas-signaling but also may downregulate the inhibitor. We conclude that a spontaneous and rapid down-regulation of Fap-1, possibly induced by TNF-alpha, a cytokine shown to be present in excess in MDS marrows, may underlie the increased apoptotic death of hematopoietic cells in these patients. Interference with Fap-1 turnover may provide a new therapeutic modality for MDS.

Sequential activation of caspase-1 and caspase-3-like proteases during apoptosis in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a group of hematopoietic disorders characterized by the concomitant presence of peripheral cytopenias and normocellular to hypercellular BM. This paradox has been proposed to be due to the presence of excessive proliferation matched by excessive intramedullary apoptosis of hematopoietic cells. When cultured in vitro MDS BM mononuclear cells (BMMC) undergo apoptosis within 4 h. We measured caspase-1-like and caspase-3-like activity in 22 MDS and 4 normal BM immediately following cell separation or after 4 h culture. When cultured in vitro, MDS BMMC demonstrated an increased apoptotic index within 4 h as measured by in situ end-labeling of fragmented DNA that was matched by a concurrent increase in caspase-3-like specific activity, and the two were significantly correlated. During the 4 h culture, a sequential activation of caspase-1-like and caspase-3-like activities was detected. Caspase-1-like specific activity was detected early and transiently at approximately 15 min, followed by a gradual increase in caspase-3-like-specific activity peaking at 2 h. When the broad-spectrum caspase inhibitor, Z-VAD.FMK, was included in the MDS BM aspirate 4 h culture, apoptosis was attenuated. We conclude that sequential activation of caspase-1-like and caspase-3-like activities may form the central biochemical pathway of apoptosis in BMMC from some MDS patients, and prevention of this process by caspase inhibitors may be of significant therapeutic value for these patients, in whom supportive care continues to be the mainstay of therapy.

Correlation of tumor necrosis factor alpha (TNF alpha) with high Caspase 3-like activity in myelodysplastic syndromes

Increased intramedullary apoptotic death of hematopoietic cells is thought to contribute to the ineffective hematopoiesis in myelodysplastic syndromes (MDS). Furthermore, high amounts of tumor necrosis factor alpha (TNF alpha) have previously been correlated with apoptosis in MDS marrows. The present studies were undertaken to examine the status of two key downstream effectors of TNF alpha signaling, i.e. Caspase 1 and Caspase 3 enzymes, using a fluorometric assay in the bone marrow aspirate mononuclear cells (BMMNC) in relation to apoptotic DNA fragmentation detected by in situ end-labeling (ISEL) of DNA and with localization of TNF alpha in the corresponding biopsies from 14 MDS patients. Both Caspase 1 and 3 were detectable in freshly harvested BMMNC, albeit median Caspase 3 levels (47.5 units/mg protein) being almost 10 times higher than Caspase 1 (4.0 units/mg protein). Upon short-term culture for 4 h in a serum-supplemented medium in vitro a significant increase was seen in Caspase 3 activity (58.8 +/- 13.9 at 0 h vs. 177.8 +/- 55.2 units/mg protein at 4 h, n = 14, P = 0.017) and in percent cells labeled by ISEL (apoptotic index or AI%: 0.76% +/- 0.25% vs. 3.99% +/- 1.1%, n = 14, P = 0.004, respectively). Caspase 1 activity increased after 15 min in culture. Interestingly, TNF alpha levels measured by immunohistochemistry correlated with the net increase in Caspase 3 activity after 4 h (p = 0.517, n = 13, P = 0.07) and the starting levels of Caspase 1 at 0 h correlated with the Caspase 3 levels attained at 4 h (p = 0.593, n = 13, P = 0.033). Additionally when TNF alpha-positive bone marrows (8/14) were compared with the negative marrows (6/14) the Caspase 3 levels were significantly higher in the TNF alpha-positive marrows (189.6 +/- 66.2 vs. 25.0 +/- 14.6 units/mg protein, respectively, P = 0.043). The increase in AI%, though not statistically significant, was also higher in the TNF alpha-positive marrows. Finally in HL60 cells the effects of different Caspase inhibitors and pentoxifylline (PTX) (interferes with lipid signaling of cytokines) on TNF alpha-induced apoptosis were evaluated. TNF alpha treatment significantly increased AI% (P < 0.003) as compared to the untreated controls. A co-treatment with three Caspase inhibitors, zVAD.FMK (inhibitor of Caspases 1 and 3, 10 microM/l), Ac.YVAD.FMK (Caspase 1 inhibitor, 1 microM/l), Ac.DEVD.FMK (Caspase 3 inhibitor, 10 microM/l) as well as PTX (250 microM/l) significantly curtailed the AI% induced by TNF alpha. The present studies thus identify the downstream effectors of TNF alpha-inducible apoptosis in MDS and so also the suppressors of TNF alpha apoptotic signaling. These results may have significant clinical implications in the therapy of MDS in the future.

Biologic characteristics of 164 patients with myelodysplastic syndromes

Rates of proliferation, apoptosis and cytokine expression were measured in bone marrow (BM) biopsies of 164 myelodysplastic syndrome (MDS) patients. There were 107 males and 57 females. Median age was 69 years and 101 had refractory anemia (RA), 17 RA with ringed sideroblasts (RARS), 38 with RA and excess blasts (RAEB) and 8 with RAEB in transformation (RAEB-t). Apoptosis measured by in-situ end labeling (ISEL) was directly related to the number of macrophages (p = 0.028, n = 83). Mean tumor necrosis factor alpha (TNF-alpha) and ISEL positivity were higher in RAEB + RAEB-t patients (p = 0.0554 and p = 0.06 respectively) while hemoglobin was higher for RA + RARS group (p = 0.0472). Patients with high apoptosis had lower white blood cell counts (p = 0.0009), lower percentage of blasts (p = 0.0009) and higher number of macrophages (p = 0.0086). We conclude that measurements of apoptosis, proliferation and cytokine expression provide important biological information which helps to distinguish RA + RARS patients from RAEB + RAEB-t patients, and may be of additive prognostic significance.

Biological characteristics of myelodysplastic syndrome patients who demonstrated high versus no intramedullary apoptosis

Spontaneous intramedullary apoptosis was measured in bone marrow (BM) biopsies of 175 patients with myelodysplastic syndromes (MDS) using in situ end-labeling (ISEL) of fragmented DNA. Two groups of high (n=71) versus low (n =43) levels of apoptosis were identified while 61 patients were ISEL-negative. Semiquantitative assessment of 3 cytokines, the number of macrophages and in vivo labeling indices (LI) were also determined from consecutive sections of the biopsy. Patients with high apoptosis levels tended to have a high LI (p=0.013), more macrophages in their BM biopsies (p=0.006) and higher tumor necrosis factor alpha (TNF-alpha) levels (not significant) compared to patients with no apoptosis. In addition, low risk MDS patients had significantly lower rates of apoptosis (p = 0.047) and lower levels of TNF-alpha (p = 0.055) compared to high-risk MDS patients. We conclude that the genesis of cytopenias in MDS is of multifactorial origin and that cytokine-associated apoptosis clearly identifies a distinct biological subgroup of patients who may benefit selectively by use of anti-cytokine therapies.

Evidence for involvement of tumor necrosis factor-alpha in apoptotic death of bone marrow cells in myelodysplastic syndromes

We previously reported excessive apoptosis and high levels of tumor necrosis factor-alpha (TNF-alpha) in the bone marrows of patients with myelodysplastic syndromes (MDS), using histochemical techniques. The present studies provide further circumstantial evidence for the involvement of TNF-alpha in apoptotic death of the marrow cells in MDS. Using our newly developed in situ double-labeling technique that sequentially employs DNA polymerase (DNA Pol) followed by terminal deoxynucleotidyl transferase (TdT) to label cells undergoing apoptosis, we have characterized DNA fragmentation patterns during spontaneous apoptosis in MDS bone marrow and in HL60 cells treated with TNF-alpha or etoposide (VP16). Clear DNA laddering detected by gel electrophoresis in MDS samples confirmed the unique length of apoptotic DNA fragments (180-200 bp). Surprisingly, however, phenotypically heterogeneous population of MDS cells as well as the homogenous population of HL60 cells showed three distinct labeling patterns after double labeling--only DNA-Pol reaction, only TdT reaction, and a combined DNA Pol + TdT reaction, albeit in different cohorts of cells. Each labeling pattern was found at all morphological stages of apoptosis. MDS mononuclear cells, during spontaneous apoptosis in 4 hr cultures, showed highest increase in double-labeled cells (DNA Pol + TdT reaction). Interestingly, this was paralleled by TNF-alpha-induced apoptosis in HL60 cells. In contrast, VP16 treatment of HL60 cells led to increased apoptosis in cells showing only TdT reaction. The double-labeling technique was applied to normal bone marrow and peripheral blood mononuclear cells after treatment with known endonucleases that specifically cause 3' recessed (BamHI), 5' recessed (PstI), or blunt ended (DraI) double-stranded DNA breaks. It was found that the DNA-Pol reaction in MDS and HL60 cells corresponds to 3' recessed DNA fragments, the TdT reaction to 5' recessed and/or blunt ended fragments, and a combined "DNA Pol + TdT reaction" corresponds to a copresence of 3' recessed with 5' recessed and/or blunt ended fragments. Clearly, therefore, apoptotic DNA fragments, in spite of a unique length, may have differently staggered ends that could be cell (or tissue) specific and be selectively triggered by different inducers of apoptosis. The presence of TNF-alpha-inducible apoptotic DNA fragmentation pattern in MDS supports its involvement in these disorders and suggests that anti-TNF-alpha (or anticytokine) therapy may be of special benefit to MDS patients, where no definitive treatment is yet available.

Tumor necrosis factor-alpha levels decrease with anticytokine therapy in patients with myelodysplastic syndromes

Tumor necrosis factor-alpha (TNF-alpha) levels were measured in the serum (sTNF-alpha) or bone marrow (BM) biopsies of 43 patients with myelodysplastic syndromes (MDS) who subsequently received therapy with a combination of pentoxifylline and ciprofloxacin (PC) with or without dexamethasone (PCD). All 43 patients received only PC therapy for 12 weeks, after which 18 of 36 nonresponders received PCD. A total of 18 of 43 patients showed a hematologic or cytogenetic response or both. BM TNF-alpha levels were semiquantitatively assessed using immunohistochemistry on a scale of 0-8+ and in the serum using enzyme linked immunoassay. The median TNF-alpha for the entire group was 3.0 in BM and 6.9 pg/ml in the serum, and 14 patients had no detectable levels. Responders had higher BM levels (median 3.5 vs. 2.0) than nonresponders, although this was not statistically significant. During PC therapy, a decline in BM TNF-alpha level was seen in the entire group, which was significant at 2 weeks (p = 0.02), 8 weeks (p = 0.001), and 12 weeks (p = 0.0001). Both responders (p = 0.01) and nonresponders (p = 0.03) had a decline at 8 weeks, but at 12 weeks, only the responders continued to show a significant decline (p = 0.03). We conclude that MDS patients with high BM TNF-alpa levels have a better chance of responding to PCD therapy and that the therapy is quite successful in reducing the TNF-alpha levels in a sustained fashion. Future studies need to be directed at identifying agents that would be more potent suppressors of the proapoptotic cytokines in these patients.

Regulation of taurocholate and ursodeoxycholate uptake in hamster hepatocytes by Ca(2+)-mobilizing agents

In isolated hamster hepatocytes, the Ca2+ ionophore A-23187 immediately decreased the uptake rate of taurocholic acid (TCA) by 60-70%, whereas it slowly inhibited that of ursodeoxycholic acid (UDCA) by a maximum of 35-45%, with an inhibition constant (Ki) of 0.36 and 1.93 microM, respectively. In contrast to ionomycin, which mimicked the effect of A-23187, vasopressin inhibited the bile acid uptake rate by 40 and 45%, respectively, only after a 5- to 10-min preincubation. The Na(+)-dependent bile acid transport was exclusively inhibited by these agents, and this inhibition was independent of extracellular Ca2+. However, intracellular Ca2+ depletion with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid or chelation with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid resulted in 40-50% inhibition of the uptake rate of both bile acids. The exogenous protein kinase C activator, phorbol 12-myristate 13-acetate (PMA), but not the nonactive 4 alpha-phorbol, significantly inhibited TCA uptake rate. Although both A-23187 and ionomycin immediately increased and decreased the cellular Na+ and K+ concentration, respectively, neither vasopressin nor PMA had a significant effect on the cellular concentration of these cations, even after a 10-min incubation. Furthermore, the effect of A-23187 and ionomycin on TCA uptake and Na+ flux, respectively, disappeared after a 40-min preincubation, and additional ionophore remained without effect. However, after a 40-min incubation with A-23187, PMA was still able to inhibit TCA uptake. Therefore, A-23187 and ionomycin transiently inhibited Na(+)-dependent uptake of both TCA and UDCA, in part because of transient alteration of the cellular Na+ and K+ concentration. Vasopressin and PMA inhibited Na(+)-dependent bile acid uptake, at least in part, through protein kinase C activation.