Effects on hemodynamic enhancement and discomfort of a new textile electrode integrated in a sock during calf neuromuscular electrical stimulation.

PURPOSE: To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES). METHODS: Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (measurement level I = ML I), and an additional mean 4 mA intensity (ML II), utilizing TTE and MPE. PVV was measured with Doppler ultrasound in the popliteal and femoral veins at baseline, ML I and II. Discomfort was assessed with a numerical rating scale (NRS, 0-10). Significance was set to p < 0.05. RESULTS: TTE and MPE both induced significant increases in PVV from baseline to ML I and significantly higher increases to ML II, in both the popliteal and femoral veins (all p < 0.001). The popliteal increases of PVV from baseline to both ML I and II were significantly higher with TTE versus MPE (p < 0.05). The femoral increases of PVV from baseline to both ML I and II were not significantly different between TTE and MPE. TTE versus MPE resulted at ML I in higher mA and NRS (p < 0.001), and at ML II in higher mA (p = 0.005) while NRS was not significantly different. CONCLUSION: TTE integrated in a sock produces intensity-dependent increases of popliteal and femoral hemodynamics comparable to MPE, but results in more discomfort at plantar flexion due to higher current required. TTE exhibits in the popliteal vein higher increases of PVV compared to MPE. TRIAL REGISTRATION: Trial_ID: ISRCTN49260430. Date: 11/01/2022. Retrospectively registered.

Population-based study of patients with primary Sjögren's syndrome and lymphoma: lymphoma subtypes, clinical characteristics, and gender differences.

Objective: To examine lymphoma subtypes, clinical characteristics, and gender differences in patients with primary Sjögren's syndrome (pSS) and lymphoma in a population-based setting.Method: Patients with Sjögren's syndrome and lymphoma diagnoses were identified by linkage of the Swedish Patient Register 1964-2007 with the Cancer Register 1990-2007. Clinical data were collected from medical records and lymphoma tissues were re-examined. The lymphoma subtype distribution was compared with the Swedish Lymphoma Register.Results: We identified 105 pSS patients with lymphoma. Diffuse large B-cell lymphoma (DLBCL) (32%) and marginal zone lymphoma [MZL including mucosa-associated lymphoid tissue (MALT) lymphoma] (31%) were the most common lymphoma subtypes. The proportion of DLBCL was not increased compared to the general population reference (32%, p = 1), in contrast to MZL (general population 5%, p < 0.0001). Compared to DLBCL, MALT lymphoma was diagnosed at a younger age (55 vs 67 years, p = 0.0001), and earlier after patient-reported sicca onset (7 vs 18 years, p = 0.0001) and pSS diagnosis (2 vs 9 years, p = 0.0005). Sixteen of the pSS-lymphoma cases were men (15%), twice the proportion in general pSS populations. Compared to women, men had a shorter median time from pSS diagnosis to lymphoma diagnosis (1 vs 8 years, p = 0.0003) and more often had lymphoma in the salivary glands (56% vs 29%, p = 0.04).Conclusion: DLBCL and MZL are common in pSS patients, but only MZL/MALT lymphoma occurs at an increased relative frequency in pSS compared to the general population. The study supports increased awareness of signs of lymphoma in men in the first years after pSS diagnosis.

Can Brief Email Guidance Enhance the Effects of an Internet Intervention for People with Problematic Alcohol Use? A Randomized Controlled Trial.

BACKGROUND: Some research suggests that internet interventions aimed at people with problematic alcohol use are more effective when provided with guidance from a therapist or coach. Purpose/Objectives: This trial intended to compare the effects of a previously evaluated internet intervention for people with problematic alcohol use when delivered with or without brief email guidance. Methods: Using online advertising, 238 participants, 18 years or older, were recruited and randomized to receive access to the Internet intervention Alcohol Help Center with or without brief email guidance from a health educator. The guidance consisted of at least four structured, slightly individualized emails delivered during the first two weeks after randomization. Participants were followed up at 3 and 6 months. Results: Number of log-ins did not differ significantly between groups throughout the follow-up period. The follow-up rate at 6 months was 47.0%. Generalized estimating equations run on the primary (standard drinks in preceding week/heavy drinking days in preceding week) and secondary outcome variables (AUDIT, AUDIT-C, quality of life) revealed no significant differences between the interventions on any of the outcomes. Conclusions/Importance: The study does not provide support for any added benefits of providing brief guidance via email in an internet intervention for problem drinkers.

Comparison of patients with and without pre-existing lymphoma at diagnosis of primary Sjögren's syndrome.

OBJECTIVE: In the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren's syndrome (pSS), pre-existing lymphoma is not an exclusion criterion for pSS diagnosis, as in earlier criteria. We aimed to explore whether there are differences between pSS patients with and without pre-existing lymphoma at pSS diagnosis. METHOD: Patients with ICD-7-10 codes for Sjögren's syndrome (SS) and a diagnosis of malignant lymphoma before or after SS diagnosis were identified by linking the Swedish Patient Register 1964-2007 with the Cancer Register 1990-2007 (n = 224). Clinical data were collected from medical records. Lymphoma diagnoses were evaluated by tissue review. Characteristics of pSS patients with and without pre-existing lymphoma were compared. RESULTS: We identified 107 patients with pSS as the reason for an SS diagnosis code and a verified lymphoma. Of these, 18 (17%) had a pre-existing lymphoma at pSS diagnosis, defined as lymphoma diagnosed before or within 6 months of pSS diagnosis. Male gender (39% vs 10%, p = 0.006), enlarged lymph nodes during the pSS disease (61% vs 27%, p = 0.01), mucosa-associated lymphoid tissue (MALT) lymphoma (50% vs 22%, p = 0.02), and salivary gland lymphoma (61% vs 26%, p = 0.006) were more common in patients with a pre-existing lymphoma at pSS diagnosis. Other pSS characteristics were similar. CONCLUSION: In a substantial proportion of patients, particularly in men, pSS remains undiagnosed until after lymphoma diagnosis. The study highlights the importance of pSS investigation in patients with lymphoma, especially MALT lymphoma, in the salivary glands.

Reduced expression of TRIM21/Ro52 predicts poor prognosis in diffuse large B-cell lymphoma patients with and without rheumatic disease.

OBJECTIVE: TRIM21 (also known as Ro52) is an autoantigen in rheumatic disease and is predominantly expressed in leucocytes. Overexpression is associated with decreased proliferation, and the TRIM21 gene maps to a tumour suppressor locus. We therefore investigated the expression of TRIM21 in patients with diffuse large B-cell lymphoma (DLBCL) and its potential usefulness as a prognostic biomarker. MATERIALS AND METHODS: TRIM21 expression levels were assessed by immunohistochemistry in lymphoma biopsies from three cohorts of patients with DLBCL: 42 patients with rheumatic disease treated with a cyclophosphamide, vincristine, doxorubicin and prednisone (CHOP)-like regimen, 76 CHOP-treated and 196 rituximab-CHOP-treated nonrheumatic patients. Expression was correlated with clinical and biomedical parameters. TRIM21 expression was assessed in relation to lymphocyte proliferation by quantitative PCR and correlated with (3) H-thymidine incorporation and propidium iodine staining. RESULTS: TRIM21 expression levels differed in the lymphomas compared to normal lymphoid tissue, with reduced expression correlating with shorter overall survival in all three cohorts. In the two larger cohorts, progression-free survival was assessed and was also found to correlate with TRIM21 expression. The association was independent of commonly used clinical prognostic scores, lymphoma subtype and several previously reported prognostic biomarkers. In agreement with this clinical observation, we noted an inverse correlation between TRIM21 expression and proliferation of leucocytes in vitro. CONCLUSIONS: We show that loss of TRIM21 expression is associated with more aggressive lymphoma and increased proliferation, whereas maintenance of TRIM21 expression is associated with better prognosis in patients with DLBCL. Based on our findings, we suggest that TRIM21 should be considered as a novel biomarker for lymphoma characterization and for predicting patient survival.

Donor or recipient origin of posttransplant lymphoproliferative disorders following solid organ transplantation.

Previous studies of donor or recipient origin of posttransplant lymphoproliferative disorders (PTLDs) following solid organ transplantation (SOT) have either been small or with selected patient groups. We studied tumor origin in a population-based cohort of 93 patients with PTLD following SOT. Tumor origin of PTLD tissue was analyzed by fluorescence in situ hybridization of the sex chromosomes in cases of sex mismatch between donor and recipient (n = 41), or HLA genotyping in cases of identical sex but different HLA type (n = 52). Tumor origin of PTLD could be determined in 67 of the 93 cases. All 67 PTLDs were of recipient origin. They were found in recipients of kidney (n = 38), liver (n = 12), heart (n = 10) and lung (n = 7). The most common recipient-derived lymphomas were monomorphic B-cell PTLDs (n = 45), monomorphic T cell PTLDs (n = 9), indolent lymphomas (n = 6), and polymorphic PTLD (n = 4). Half of the recipient-derived PTLDs were Epstein-Barr virus-positive. Twelve of the recipient-derived PTLDs were located in the grafts: in four cases exclusively and in eight cases in combination with disseminated disease outside the graft. Tumor origin was indeterminable in 26 cases, probably due to low DNA quality. We conclude that the vast majority of PTLDs after SOT was of recipient origin.

Dose-densified chemoimmunotherapy followed by systemic central nervous system prophylaxis for younger high-risk diffuse large B-cell/follicular grade 3 lymphoma patients: results of a phase II Nordic Lymphoma Group study.

BACKGROUND: Many patients with aggressive B-cell lymphomas and high clinical risk score still die of lymphoma after conventional R-CHOP chemoimmunotherapy. We hypothesized that intensified chemoimmunotherapy including systemic central nervous system (CNS) prophylaxis improves outcome and reduces the incidence of CNS-related events. PATIENTS AND METHODS: Inclusion criteria were age 18-65 years, primary diffuse large B-cell lymphoma or grade III follicular lymphoma without clinical signs of CNS disease and negative cerebrospinal fluid cytology, age-adjusted International Prognostic Index 2-3 and WHO performance score 0-3. Treatment consisted of six courses of R-CHOEP-14 followed by a course of high-dose cytarabine and a course of high-dose methotrexate. Primary end point was failure-free survival (FFS) at 3 years. RESULTS: A total of 156 eligible patients with a median age of 54 years (range 20-64) were included. Three toxic deaths were observed. Three-year overall survival (OS) and FFS rates (median observation time 52 months for survivors) were 81% and 65%, respectively. Seven patients experienced CNS relapse, all within 6 months. CONCLUSIONS: The results are promising with favorable 3-year OS and FFS rates, a low toxic death rate and a lower than expected number of CNS events. CNS progression might be further reduced by earlier CNS prophylaxis. CinicalTrials.gov. identifier NCT01502982.

Gene expression and copy number profiling of follicular lymphoma biopsies from patients treated with first-line rituximab without chemotherapy.

The Nordic Lymphoma Study Group has performed two randomized clinical trials with chemotherapy-free first-line treatment (rituximab +/- interferon) in follicular lymphoma (FL), with 73% of patients alive and 38% without any need of chemotherapy after 10.6 years median follow-up. In order to identify predictive markers, that may also serve as therapeutic targets, gene expression- and copy number profiles were obtained from 97 FL patients using whole genome microarrays. Copy number alterations (CNAs) were identified, e.g. by GISTIC. Cox Lasso Regression and Lasso logistic regression were used to determine molecular features predictive of time to next therapy (TTNT). A few molecular changes were associated with TTNT (e.g. increased expression of INPP5B, gains in 12q23/q24), but were not significant after adjusting for multiple testing. Our findings suggest that there are no strong determinants of patient outcome with respect to GE data and CNAs in FL patients treated with a chemotherapy-free regimen (i.e. rituximab +/- interferon).

A closer look at non-Hodgkin's lymphoma cases in a national Swedish systemic lupus erythematosus cohort: a nested case-control study.

OBJECTIVE: To investigate risk factors for non-Hodgkin's lymphoma (NHL) and analyse NHL subtypes and characteristics in patients with systemic lupus erythematosus (SLE). METHODS: A national SLE cohort identified through SLE discharge diagnoses in the Swedish hospital discharge register during 1964 to 1995 (n = 6438) was linked to the national cancer register. A nested case control study on SLE patients who developed NHL during this observation period was performed with SLE patients without malignancy as controls. Medical records from cases and controls were reviewed. Tissue specimens on which the lymphoma diagnosis was based were retrieved and reclassified according to the WHO classification. NHLs of the subtype diffuse large B cell lymphoma (DLBCL) were subject to additional immunohistochemical staining using antibodies against bcl-6, CD10 and IRF-4 for further subclassification into germinal centre (GC) or non-GC subtypes. RESULTS: 16 patients with SLE had NHL, and the DLBCL subtype dominated (10 cases). The 5-year overall survival and mean age at NHL diagnosis were comparable with NHL in the general population-50% and 61 years, respectively. Cyclophosphamide or azathioprine use did not elevate lymphoma risk, but the risk was elevated if haematological or sicca symptoms, or pulmonary involvement was present in the SLE disease. Two patients had DLBCL-GC subtype and an excellent prognosis. CONCLUSIONS: NHL in this national SLE cohort was predominated by the aggressive DLBCL subtype. The prognosis of NHL was comparable with that of the general lymphoma population. There were no indications of treatment-induced lymphomas. Molecular subtyping could be a helpful tool to predict prognosis also in SLE patients with DLBCL.

The G(-248)A polymorphism in the promoter region of the Bax gene does not correlate with prognostic markers or overall survival in chronic lymphocytic leukemia.

The G(-248)A polymorphism in the promoter region of the Bax gene was recently associated with low Bax expression, more advanced stage, treatment resistance and short overall survival in B-cell chronic lymphocytic leukemia (CLL), the latter particularly in treated patients. To investigate this further, we analyzed 463 CLL patients regarding the presence or absence of the G(-248)A polymorphism and correlated with overall survival, treatment status and known prognostic factors, for example, Binet stage, VH mutation status and genomic aberrations. In this material, similar allele and genotype frequencies of the Bax polymorphism were demonstrated in CLL patients and controls (n=207), where 19 and 21% carried this polymorphism, respectively, and no skewed distribution of the polymorphism was evident between different Binet stages and VH mutated and unmutated CLLs. Furthermore, no difference in overall survival was shown between patients displaying the G(-248)A polymorphism or not (median survival 85 and 102 months, respectively, P=0.21), and the polymorphism did not influence outcome specifically in treated CLL. Neither did the polymorphism affect outcome in prognostic subsets defined by VH mutation status or genomic aberrations. In conclusion, the pathogenic role and clinical impact of the Bax polymorphism is limited in CLL.

Rheumatoid Arthritis and Risk of Malignant Lymphoma: Is the Risk Still Increased?

OBJECTIVE: Patients with rheumatoid arthritis (RA) are at increased risk of malignant lymphomas with a strong correlation with RA disease severity. Given the changes in RA therapy over recent decades, this study was undertaken to assess whether lymphoma risk remains increased, and if so, to explore risk predictors and lymphoma subtypes. METHODS: We identified 12,656 cases of incident RA in the Swedish Rheumatology Quality Register 1997-2012 and obtained information on therapy and inflammatory activity during the first year after diagnosis. Each patient was matched to 10 population comparator subjects. Through linkage to the Swedish Cancer Register, lymphomas, including subtypes, were identified. We assessed hazard ratios (HRs) using Cox regression. RESULTS: Overall, the HR for lymphoma was increased in RA, to 1.6 (95% confidence interval [95% CI] 1.2-2.1). Taking RA duration into account, risks did not appear to have declined over successive calendar years of RA diagnosis. Neither use of methotrexate the first year after RA diagnosis nor ever use of tumor necrosis factor inhibitors (TNFi) increased lymphoma risk (HR 0.9 [95% CI 0.4-1.9]). Use of oral corticosteroids the first year after RA diagnosis was associated with a reduced risk (HR 0.5 [95% CI 0.3-0.9]). Inflammatory activity during the first year after RA diagnosis did not predict future lymphoma risk. Chronic lymphocytic leukemia occurred less frequently, and Hodgkin's lymphoma occurred more frequently, in RA patients than in the general population. CONCLUSION: The average lymphoma risk in recently diagnosed RA is similar in magnitude to that reported in historical cohorts. Standard antirheumatic treatment including TNFi did not predict future lymphoma risk. Distribution of lymphoma subtypes warrants further investigation.

Isozymes of acid esterase and acid phosphatase in permanent human hematopoietic cell lines.

Net enzyme activities of normal human blood cells were measured, and isoelectric focusing patterns of acid esterase (AcE) (EC 3.1.1.6) and acid phosphatase (AcP) (EC 3.1.3.2) were compared with corresponding data obtained for two acute T-lymphoblastic leukemia cell lines (JM, Molt-4), one acute B-lymphoblastic leukemia cell line (Ball-1), one acute non-B-non-T-lymphoblastic leukemia cell line (KM 3), and one promyelocytic leukemia cell line (HL-60). The AcE isozymes, found in the individual blood cell types, were regularly expressed by the corresponding cell lines. AcP was regularly expressed by lines HL-60 and KM 3, but lines JM, Molt-4, and Ball-1 showed additional isozymes and/or reduction of the intensity of the typical isozymes found in the presumed normal counterparts. This phenomenon resulted partly in an obscuration of the typical isozyme patterns. Our study documents the applicability of isozyme mapping to the characterization of permanent hematopoietic cell lines. The results suggest that long-term culture conditions can repress phenotypic properties and/or derepress gene activities.

Bimodal differentiation prospectives for promyelocytes.

In accordance with the long-range goal to demonstrate the direct derivation of blood monocytes from promyelocytes in human bone marrow, the promyelocytic cell line HL-60 in the present study was differently stimulated with various inducers for the purpose of documenting its capability to evolve into granulocytes or monocytes-macrophages. Each differentiation line was monitored with the use of marker enzymes, antigens, and cell-specific monoclonal antibodies. In addition, studies were done on normal human bone marrow and leukemias. The results provided strong evidence for the close cytogeneic relationship of granulocytes and monocytes and for a common progenitor at the maturation stage of promyelocytes-myelocytes for both cell lineages.

Phorbol ester and B cell-stimulatory factor synergize to induce B-chronic lymphocytic leukemia cells to simultaneous immunoglobulin secretion and DNA synthesis.

This paper discusses the response of two B cell-type chronic lymphocytic leukemia (B-CLL) clones, 173 and 183, to the phorbol ester TPA combined with a B cell-stimulatory factor (BSF) derived from a T helper cell hybridoma (MP6). Previous studies with 173 and 183 cells have consistently shown that TPA alone induces differentiation but no proliferation. However, when the two clones were exposed to TPA plus BSF-MP6, not only differentiation but also DNA synthesis was observed. Compared with TPA exposure alone, the fraction of cells with induced lymphoblastoid-plasmacytoid morphology increased and Ig secretion was enhanced. By a 1-hr TPA pulse followed by BSF-MP6, the DNA synthesis was further augmented, but less maturation was observed. T cell and monocyte removal, using cell sorting, showed that the DNA synthesis induced was independent of these cell types, also under serum-free conditions. Quantitation of several cell cycle-associated surface Ags showed that the 4F2, Ba, Bac-1, and cD23 Ags increased while the CD37 decreased in expression upon addition of BSF-MP6. We conclude that B-CLLs are inducible by TPA and BSF-MP6 not only to differentiation, but also to DNA synthesis even under serum-free conditions in vitro. The results furthermore suggest that the very low proliferation activity in B-CLL tumors in vivo may reflect a relative deficiency of proper growth and differentiation factors or a subnormal response of B-CLL cells to such factors.

Feasibility of the fluorometric microculture cytotoxicity assay (FMCA) for cytotoxic drug sensitivity testing of tumor cells from patients with acute lymphoblastic leukemia.

The automated fluorometric microculture cytotoxicity assay (FMCA) was used for chemotherapeutic drug sensitivity testing of fresh and cryopreserved tumor cells from patients with acute lymphoblastic leukemia (ALL) at diagnosis and relapse. The technique success rate was 87% for fresh and 81% for cryopreserved samples. Up to 16 different cytotoxic drugs were routinely tested, but neither asparaginase nor methotrexate produced dose-response related cell kill. FMCA data showed good correlation to the well established Disc assay and the drug sensitivity reported by the FMCA was in good agreement with known clinical activity. Samples from children and initial ALL tended to be more drug sensitive than those from adults and ALL at relapse, respectively. For 36 samples clinical outcome was correlated to the quartile position in comparison to all other samples for the most in vitro active drug actually given to the patient. For patients with samples in the first, second, third, and fourth quartiles, the probabilities of complete remission were 89, 57, 38, and 0%, respectively. Using the median value as cut-off line, the sensitivity and specificity of the assay were 87 and 62%, respectively. It is concluded that the FMCA with a minimum of effort and with high success rate report clinically relevant drug sensitivity profiles for ALL.

Increased serum levels of interleukin-9 correlate to negative prognostic factors in Hodgkin's lymphoma.

Hodgkin's lymphoma (HL) is characterised by an unbalanced cytokine secretion. Many of these cytokines have been implicated in the regulation of malignant and infiltrating cells. Interleukin-9 (IL-9) has been described to act in an autocrine fashion in HL, stimulating proliferation of the malignant cells. To investigate the potential clinical implication of this observation, a novel ELISA method was used to examine the serum levels of IL-9 in lymphoma patients. High levels of IL-9 were found in the sera from patients with HL (18/44), but not in the sera from non-Hodgkin's lymphoma patients (3/21) or healthy controls. The highest serum IL-9 levels, up to 3350 pg/ml, were observed in the nodular sclerosis subtype, and there was a correlation between IL-9 levels and the negative prognostic factors advanced stage, B-symptoms, low blood Hb and high erythrocyte sedimentation rate. Furthermore, there was no correlation between serum levels of IL-9 and IL-13, a cytokine where serum levels have been speculated to be of clinical importance. This is the first report showing that IL-9 can be measured in serum samples. A novel correlation between increased serum IL-9 levels, HL and clinical features is shown, suggesting that IL-9 is a candidate factor contributing to the development of HL.

Stem cell factor, but not flt3 ligand, induces differentiation and activation of human mast cells.

We have examined the effect of human ligand for the flt3/flk2 tyrosine kinase receptor on the differentiation of human mast cells in suspension cultures. We also explored the effect of flt3 ligand (FL) on the human mast cell line HMC-1 and mRNA expression of flt3/flk2 on in vitro developed human mast cells and HMC-1. The growth of cord blood mononuclear cells in suspension cultures was increased when cells were cultured in the presence of FL compared with cells cultured in the presence of stem cell factor (SCF). When SCF and FL were combined, the total cell growth was increased further. Our data show that Fl by itself neither induced differentiation of mast cells nor acted in the SCF-dependent differentiation of human cord blood-derived mast cells (CBMC). Furthermore, no effects of FL were found on the proliferation of HMC-1 cells or the induction of early-immediate response genes in HMC-1 cells. In addition, neither HMC-1 cells nor CBMC expressed mRNA for flt3. As has been shown before, SCF and FL have little biological effect on their own but synergize well with a number of other hematopoietic growth factors. This study shows that a major difference between FL and SCF is that only SCF affects the differentiation and activation of mast cells.

Enrichment of epidermal Langerhans cells: studies with a monolayer technique and flow cytometry sorting.

Langerhans cells were enriched from epidermal cell suspensions by a monolayer technique based on the association of Langerhans cells with solid matrix-bound anti-Ia antibodies or by flow cytometry sorting of fluorescein-isothiocyanate labeled anti-Ia reactive cells. The monolayer technique gave a moderate enrichment (15-37%) whereas considerably higher purity (73-87%) was obtained by flow cytometry sorting. The identity of the enriched anti-Ia reactive cells as Langerhans cells was established by histochemical techniques or electron microscopy. The monolayer-enriched Langerhans cells could function as stimulating cells in the mixed leukocyte culture reaction and as antigen-presenting cells.

Predicting malignancy grade with PET in non-Hodgkin's lymphoma.

UNLABELLED: Our goal was to determine whether PET with 11C-methionine and/or 18FDG could predict malignancy grade in non-Hodgkin's lymphoma (NHL). METHODS: Twenty-three patients with high-grade, low-grade or transformed low-grade NHL were investigated. Standardized uptake values (SUV), transport rate and mass influx values were calculated both for the whole tumor [mean regions of interest, (ROI)] and for the tumor area with the highest levels of activity, comprising four contiguous pixels within each tumor and designated as a hot spot. RESULTS: Both 11C-methionine and 18FDG detected all tumors. In addition, 18FDG discriminated between high- and low-grade NHL, whereas 11C-methionine did not. With 18FDG, three transformed low-grade NHLs behaved in an intermediate manner. All quantitative uptake values correlated well with each other for both tracers, except for the mean ROI SUV and transport rate of 11C-methionine. Quantifications of mean ROI uptake and hot spots were strongly correlated. CONCLUSION: The results of this study together with previous findings from other studies indicate that 18FDG but not 11C-methionine can predict malignancy grade in NHL. Further studies with a larger series of patients are needed.

Low cytidine deaminase levels in human hematopoietic cell lines.

Purine and pyrimidine enzyme profiles of human cell lines have been investigated. A novel observation was the finding that most of the cell lines showed very low or undetectable levels of cytidine (deoxycytidine) deaminase, while they possessed pyrimidine 5'-nucleotidase, cytidine and deoxycytidine kinase activities. Most cell lines showed high levels of adenosine deaminase and purine nucleoside phosphorylase activities and low levels of purine 5'-nucleotidase. We propose that high adenosine deaminase and purine nucleoside phosphorylase activities and low cytidine deaminase activity may be of importance for immature hematopoietic cells in order to ensure a balanced synthesis of the DNA precursors.