Active surveillance of low-grade prostate cancer using the SurACaP Criteria: A multi-institutional series with a median follow-up of 10years.

PURPOSE: To report on the oncological outcomes of active surveillance (AS) in low-grade prostate cancer (PCa) patients using the French SurACaP protocol, with a focus on long-term outcomes. METHODS: This multicenter study recruited patients with low-grade PCa between 2007 and 2013 in four referral centers in France. The cohort included patients meeting the SurACaP inclusion criteria, i.e., aged ≤75years, with low-grade PCa (i.e., ISUP 1), clinical stage T1c/T2a, PSA ≤10ng/mL and ≤3 positive cores and tumor length ≤3mm per core. The SurACaP protocol included a digital rectal examination every six months, PSA level measurement every three months for the first two years after inclusion and twice a year thereafter, a confirmatory biopsy in the first year after inclusion, and then follow-up biopsy every two years or if disease progression was suspected. Multiparametric magnetic resonance imaging (mpMRI) was progressively included over the study period. RESULTS: A total of 86 consecutive patients were included, with a median follow-up of 10.6 years. Only one patient developed metastases and died of PCa. The estimated rates of grade reclassification and treatment-free survival at 15 years were 53.4% and 21.2%, respectively. A negative mpMRI at baseline and a negative confirmatory biopsy were significantly associated with a lower risk of disease progression (P<0.05). CONCLUSIONS: AS using the French SurACaP protocol is a safe and valuable strategy for patients with low-risk PCa, with excellent oncological outcomes after more than 10 years' follow-up. Future studies are crucial to broaden the inclusion criteria and develop a personalized, risk based AS protocol with the aim of de-escalating follow-up examinations. LEVEL OF EVIDENCE: Grade 4.

Active surveillance in favorable intermediate-risk prostate cancer: A single-center experience.

PURPOSE: To report the long-term oncological outcomes of active surveillance (AS) in selected patients with favorable intermediate-risk (IR) prostate cancer (PCa). METHODS: A retrospective database review of two academic centers was conducted to identify favorable IR PCa patients initially managed by AS between 2014 and 2022. Favorable IR PCa was defined by the presence of one single element of IR disease (i.e., PSA 10-20ng/mL, Gleason Grade Group [GG] 2, or cT2b). All patients were diagnosed and followed up according to a contemporary scheme, including MRI and image-guided biopsies. The primary endpoint was metastasis-free survival. RESULTS: A total of 57 patients met our inclusion criteria and the median follow-up was 56months. During follow-up, there were no cases of metastasis or death due to PCa, but 6 deaths due to competing causes. A total of 25 (44%) and 6 patients (11%) had definitive treatment and GG 3 reclassification during follow-up, respectively. In multivariable Cox hazard regression analysis, the risk of undergoing definitive treatment was significantly associated with PSA density>0.15 (HR: 4.82, 95% CI: 1.47 to 15; P=0.01) and PI-RADS 4-5 lesions on mpMRI (HR: 2.48, 95% CI: 1.06 to 5.19; P=0.006). Interestingly, tumor burden (P=0.3) and GG (P=0.7) on biopsy were not associated with definitive treatment. CONCLUSIONS: AS is a safe and valuable strategy for well-selected patients with favorable IR prostate cancer, with excellent oncological outcomes after five years' follow-up.

Chorionic gonadotropin secretion is associated with an inhibition of follicular growth and an improvement in oocyte competence for in vitro maturation in the mare.

This study reports the follicular growth and oocyte competence for in vitro maturation and fertilization under the influence of circulating eCG. Three to 7 successive ultrasound-guided follicular punctures were performed on 4 pregnant mares from Day 23 until Day 75 of pregnancy and on 5 control mares whose embryonic vesicle was crushed on Day 22. All follicles larger than 5 mm were punctured 24 h after the largest follicle reached 18 mm. Expanded cumulus oocyte complexes (COCs) were stained at recovery to analyze the nuclear stage. Compact COCs were cultured in vitro for 46 h and either stained or processed for in vitro fertilization (IVF) and stained 26 h after IVF. In the control group, no mares showed an increase in eCG levels, whereas all the pregnant mares had concentrations higher than 100 ng/ml from Day 37. The number of follicles flushed during each puncture attempt significantly decreased with time for 3 of 4 pregnant mares. No significant change in this number was observed for the 5 control mares. The maturation rate of the oocytes from follicles 10-14 mm was significantly higher in the pregnant vs. the control group (14 of 17, 82%, vs. 13 of 30, 43%). The difference was not significant for the oocytes from follicles smaller than 9 mm or larger than 15 mm. After IVF, no oocyte was fertilized. The results led us to conclude that eCG is associated with an inhibition of follicular growth and an improvement in oocyte competence for in vitro maturation.

High-performance liquid chromatography/electrospray mass spectrometry for the analysis of modified bases in DNA: 7-(2-hydroxyethyl)guanine, the major ethylene oxide-DNA adduct.

A method was developed for the analysis of 7-(2-hydroxyethyl)guanine (7HEG), the major DNA adduct formed after exposure to ethylene oxide (EO). The method is based on DNA neutral thermal hydrolysis, adduct micro-concentration, and final characterization and quantification by HPLC coupled to single-ion monitoring electrospray mass spectrometry (HPLC/SIR-ESMS). The method was found to be selective, sensitive, and easy to handle with no need for enzymatic digestion or previous sample derivatization. Detection limit was found to be close to 1 fmol of adduct injected (10(-10) M), thus allowing the detection of approximately three modified bases on 10(8) intact nucleotides in blood sample analysis. Quantification results are shown for 7HEG after calf thymus DNA and blood exposure to various doses of EO, in both cases obtaining clear dose-response relationships.

Molecular components of the B-cell antigen receptor complex of the IgM class.

The antigen receptors on mature B lymphocytes are membrane-bound immunoglobulins of the IgM and IgD classes whose cross-linking by polyvalent antigens results in B-cell proliferation and differentiation. How these membrane-bound immunoglobulin chains, which lack a cytoplasmic tail, generate a cell activation signal is not at present known. We now show that the IgM molecule is non-covalently associated in the membrane of B cells with two proteins of relative molecular mass 34,000 (Mr 34 K; IgM-alpha) and 39 K (Ig-beta) which form a disulphide-linked heterodimer. Surface expression of IgM seems to require the formation of an appropriate complex between IgM and the heterodimer. A transfection experiment indicates that IgM-alpha is the product of mb-1, a B-cell specific gene encoding a transmembrane protein with sequence homology to proteins of the T-cell antigen receptor-CD3 complex.

A novel germ-line JK transcript starting immediately upstream of JK1.

Germ-line transcripts of the immunoglobulin (Ig) and T cell receptor loci are thought to be involved in the control of V gene rearrangement by rendering these loci accessible to the recombinases. We have analyzed the transcriptional activity of germ-line K alleles in two bone marrow-derived Abelson-murine leukemia virus transformed pre-B cells: 300-19, a null cell line, and P8 a mu-producing line. We found a novel germ-line JK transcript starting immediately upstream of JK1 and spliced to CK. The potential role of this transcript in the opening of the Ig K locus as well as in the ordered usage of JK segments is discussed.

A novel 34-kd protein co-isolated with the IgM molecule in surface IgM-expressing cells.

Plasmacytoma cells, transfected with a vector encoding a membrane-bound IgM molecule, do not show cell surface IgM expression, although complete IgM molecules are assembled intracellularly. The isolation of a surface IgM-positive variant allowed us to analyse molecular requirements of surface IgM expression. Only in surface IgM-positive cells, a 34-kd protein (B34) was found to be associated with IgM. B34 is a glycoprotein which forms a disulphide-linked homodimer. The surface IgM-positive variant cell line expressing B34 also contains transcripts of the pre-B and B cell specific mb-1 gene. The data are discussed in the context of a possible IgM-antigen receptor complex.

Cin4, an insert altering the structure of the A1 gene in Zea mays, exhibits properties of nonviral retrotransposons.

A wild-type allele of the A1 gene of Zea mays contains a 1.1-kb-long insert termed Cin4-1, which alters the structure of the transcription unit compared to other A1 alleles. The Cin4-1 element is a member of a family of elements occurring in 50-100 copies in the maize genome. Genomic cloning and sequence analysis of several family members and their flanking regions allowed classification of Cin4 as a nonviral retrotransposon. Individual Cin4 elements terminate in an oligo(A) track of variable size (6-11 residues) at their 3'-end. The 5'-ends of family members are heterogeneously truncated with respect to the longest Cin4 element. Cin4 elements are flanked by small direct duplications, the size of which varies between 3 and 16 bp. On the basis of a comparison of the target sequence and the sequence of Cin4 we suggest and discuss a model of the mechanism of Cin4 integration via in situ cDNA synthesis on an RNA template. The longest Cin4 element analysed so far has two non-overlapping open reading frames (ORFs) comprising 2793 nucleotides (ORF1) and 3489 nucleotides (ORF2). The putative 1163 amino acid long Cin4 protein derived from the sequence of ORF2 has the capacity to encode a reverse transcriptase-like protein and a DNA-binding domain. The conservation pattern of these two domains and the overall organisation of Cin4 is similar to that detected in nonviral retrotransposons in animals. The origin and function of Cin4 are discussed.

Supernatant from a cloned helper T cell stimulates resting B cells to express transferrin and IL-2 receptors.

We describe the properties of the supernatant from a murine cloned helper T cell (clone 52.3) which is able to polyclonally activate most resting B cells in the absence of any additional stimulus. We hypothesize that an activity which we call BCAF (B-cell-activating factor(s] exists in our supernatant which can activate resting B cells alone or in conjunction with other lymphokines. In the present report, we investigate changes in the surface antigen pattern induced on resting B cells by BCAF-containing supernatant. Analysis of the cells by flow cytometry shows that transferrin receptor and IL-2 receptor expression increase on a large fraction of B cells after 2 days of activation by the T-helper-cell clone supernatant. Monoclonal anti-transferrin receptor antibody inhibits cell division but does not affect blastogenesis, while IL-2 has no effect in our experimental system. Our present results confirm that BCAF-containing supernatants can act on most resting B cells and replace helper T cells in inducing B-cell activation and proliferation.

Influence of transposable elements on the structure and function of the A1 gene of Zea mays.

The structure of the A1 gene of Zea mays was determined by sequencing cDNA and genomic clones. The gene is composed of four exons and three short introns. The 40.1-kd A1 protein is an NADPH-dependent reductase. Germinal derivatives of the mutable a1-m1 allele with either recessive or wild-type phenotype have been isolated. Sequence analysis of these revertant alleles indicates that frame-shift mutations abolish A1 gene function, whereas one additional amino acid within the protein sequence still allows wild-type gene expression. The presence of a second, promoter-like structure, upstream of the functional A1 gene promoter is discussed with respect to its possible involvement in differential expression of the A1 gene. The structure of the a1-m2 8004, 3456 and 4412 alleles, featuring distinguishable phenotypes in the presence of Spm(En), was also determined. In all alleles the 1080-bp-long inhibitor (I) element is located 15 bp upstream of the CAAT box of the A1 gene promoter. The unusual response of a1-m2 alleles to trans-active signals of the Spm(En) element is discussed with respect to the position of the I inserts. Also presented are data on the structure and insertion sites of transposable elements determined by cloning and sequencing of the mutable a1 alleles a1-mpapu, a1-mr 102 and a1-ml.

B cell activating factor(s) (BCAF) containing supernatant can induce all classes of immunoglobulin and IgG switches in resting B cells.

We have previously shown (L. Leclercq et al., Proc. Nat. Acad. Sci. 1984, 81:6491) that the supernatants of activated T helper cells can stimulate resting B cells to proliferate and to express early activation markers. The corresponding activity has been called B Cell Activating Factor or BCAF. Here we show that BCAF-containing supernatants can induce resting B cells to produce immunoglobulins of all isotypes as measured by enzyme linked immunoabsorbent assay. The isotype pattern obtained is similar to the one obtained when TH cells are cocultured with unprimed resting B cells. Furthermore, BCAF-containing supernatants induce IgG switches as measured by the secretion of IgG3, IgG1, IgG2a and IgG2b immunoglobulin by cell sorted surface IgG- resting B cells. These investigations confirm that BCAF-containing supernatants can act on resting B cells.

Supernatant from a cloned helper T cell stimulates most small resting B cells to undergo increased I-A expression, blastogenesis, and progression through cell cycle.

Helper T cell clone 52.3 supernatant (52.3 SN) was previously shown to be able to stimulate gradient-purified murine resting B cells in the absence of any additional stimulus. However, the proportion of cells that were accounting for the thymidine uptake and the Ig production was unknown. In this paper, we have studied induced changes that can be measured at the single cell level, and have thus determined the frequency of resting B cells that respond to 52.3 SN. Results indicate that 52.3 SN induces an increased I-A expression and a cell size enlargement on virtually all resting B cells. A significant proportion (30%) of these cells later becomes large blasts. Acridine orange staining revealed that in the presence of 52.3 SN a large fraction of the resting B cells undergoes the G0 to G1 transition. Furthermore, 52.3 SN is able to induce at least 20% of the cells to continue through the cell cycle into S phase as indicated by propidium iodide staining of DNA. Finally, a fraction of the 52.3 SN-stimulated cells differentiate to Ig-producing cells. Our present results suggest that resting B cells express functional receptors for some lymphokines and that these lymphokines can act in the absence of membrane Ig occupancy. Our findings further support the existence of a B cell-activating factor acting in a MHC-unrestricted manner and responsible for the entry of resting B cells into cell cycle. The relationship between this factor and other lymphokines is discussed.

Antigen-specific major histocompatibility complex-restricted helper T cell clones are sufficient to induce unprimed B cells to switch and to secrete IgG and IgA in a primary in vitro polyclonal response.

To investigate the role of helper T (Th) cells in the regulation of the production of the various immunoglobulin (Ig) classes and subclasses, we have used poly (Glu60 Ala30Tyr10) (GAT)-specific, major histocompatibility-complex-restricted Th cell clones to stimulate unprimed B cells. The T cells used in these studies were Thy-1+, Lyt-1+, Lyt-2- and lacked Fc receptor for IgM, IgG and IgA, and the unprimed splenic B cells were selected by the fluorescence-activated cell sorter for their lack of expression of surface (s)IgG and by panning for their lack of expression of sIgA. We have taken advantage of the ability of some antigen-specific major histocompatibility complex (MHC)-restricted Th cell clones to polyclonally activate unprimed B cells in vitro in the presence of high doses of antigen. We have shown that under these conditions, an antigen-specific MHC-restricted Th cell clone is sufficient to induce the switch of sIgG- sIgA- unprimed B cells to IgG and IgA, as well as the expansion of these cells and their differentiation into IgG and IgA-secreting cells. Isotype-specific Th cells thus do not seem to be an absolute requirement for the production of the various IgG subclasses and of IgA.

Differential requirements for the production by a T helper clone of the lymphokines involved in the induction of polyclonal proliferation and differentiation of unstimulated B lymphocytes.

Antigen-activated T helper (TH) cells secrete into their supernatant various lymphokines that are able to drive B cells to proliferate and to differentiate into Ig-secreting cells. In this report, we compared the production of these two types of activities by a TH clone. We found that B cell proliferating activity was released by TH cells under conditions in which T cell proliferation and the release of the B cell differentiating activity were totally blocked by anti-L3T4 monoclonal antibody GK1.5. The release of these two activities also dissociated during the reversion of T cells to the resting state after activation with antigen. Two weeks after activation, the T cell clone still secreted B cell proliferating activity, but did not secrete B cell differentiating activity. Three to four weeks after activation, neither activity was produced. The data suggest that the genes coding for these two activities are independently regulated in activated T cells. The implications of these observations concerning B lymphocyte development are discussed.

Regulation of IgM expression by adjuvant activated splenic suppressor T cells.

Adjuvant-activated Lyt-2 positive suppressor T cells (Ts) are able to inhibit the expression of IgM plaque-forming cells (PFC) during a primary in vitro response to sheep red blood cells. Under the same experimental conditions these suppressor T cells do not affect a secondary IgM PFC response against SRBC. Activated Ts cells were also found to suppress the spontaneous IgM secretion of cultured B cells as well as the IgM production of B cells stimulated by lipopolysaccharide or by supernatant from a T-helper-cell clone.

Antigen-specific helper T-cell clone supernatant is sufficient to induce both polyclonal proliferation and differentiation of small resting B lymphocytes.

Gradient-purified resting B lymphocytes can be polyclonally stimulated by antigen-specific major histocompatibility complex (MHC)-restricted helper T lymphocytes as well as by antigen-activated helper T-cell supernatant. In contrast to what has been described so far, we show that helper T-cell supernatant (in the absence of any other added stimulus, such as that provided by anti-mu antibodies) is sufficient to induce both proliferation of resting B cells and their differentiation into IgM-secreting cells. The stimulation induced by the helper T-cell supernatant takes place in serum-free medium and is not MHC-restricted. Our findings strongly support the existence of a B-cell activating factor acting on the resting B cell and causing it to enter the G1 phase of the cell cycle in a MHC-unrestricted manner.

In vitro induction and expression of interleukin 2 receptor in a clonal T helper cell differentiation model.

Induction and expression of interleukin 2 (IL 2) receptor have been studied using a poly( Glu60 Ala30 Tyr10 ) (GAT)-specific T cell clone of mouse origin. This clone (52-3) has been characterized and it exhibits functional properties of T helper (TH) cells: it leads to a specific anti-DNP response in the presence of DNP-GAT and DNP-primed B cells and it secretes biological activities which can induce polyclonal B cell proliferation and IgM secretion. In vitro this clone mimics the activation stages of normal T lymphocytes and can be obtained under two states of differentiation. depending on the antigen-specific signal provided by antigen-presenting cells (APC). The expression of IL 2 receptor by this clone has been studied by (i) its response to IL 2, (ii) its capacity to absorb IL 2 bioactivity, and (iii) its reactivity with monoclonal antibody 7D4 specific for mouse IL 2 receptor. All the results indicate that the unstimulated state does not express the IL 2 receptor while the activated state does. Clone 52-3 has been compared with clone 14-1.6 that derives from a TH cell line and expresses the IL 2 receptor constitutively. 52-3 offers a good experimental model for studying in vitro, in a clonal TH cell population, the detailed mechanism of IL 2 receptor induction.

Public idiotopes and/or internal images in the anti-poly(Glu60Ala30Tyr10) response: analysis by monoclonal antibodies.

From BALB/c mice immunized with BALB/c polyclonal anti-GAT antibodies, we have obtained monoclonal antiidiotypic antibodies directed against public idiotopes expressed following GAT (Glu60Ala30Tyr10) immunization in all individuals of all mouse strains tested. Nine monoclonal anti-Id antibodies were studied in detail. One of these monoclonals recognizes only polyclonal anti-GAT antibodies; the other eight recognize polyclonal anti-GAT antibodies and monoclonal anti-GAT antibodies. The distribution of the structures recognized by the different monoclonal anti-Id on a battery of twenty monoclonal anti-GAT antibodies allows a definition of two families of public idiotopes. The significance of the existence of these two families is discussed in light of the hypothesis recently proposed by Jerne et al. (EMBO J., 1982, 1, 243-247) who consider that the induction of internal images of antigen during immunization leading to the production of antiidiotypic reagents is responsible for the existence of public idiotopes. Our present results may be interpreted to indicate that even though certain monoclonal anti-Id reagents could be internal images of the antigen, the others do, in fact, recognize public idiotopes. Therefore, the notion of internal image does not exclude the existence of public idiotypic specificities.

Idiotype expression and fine specificity of Glu60Ala30Tyr10-specific T proliferating cells.

The fine specificity of anti-Glu60Ala30Tyr10 (GAT) and anti-Glu60Ala40 (GA) proliferating cells was studied. T cells primed with GAT proliferate both to GAT and GA and GA-primed T cells proliferate also to GA and GAT. This cross-reactivity was unexpected given the results previously reported on the fine specificity of anti-GAT antibodies. The effect on the proliferation of BALB/c lymph node cells (LNC) of a syngeneic anti-idiotypic serum, prepared in BALB/c against anti-GAT antibodies, was studied. Two major points are made in this paper: (i) the in vitro addition of the anti-idiotypic serum in cultures containing GAT-primed LNC and GAT enhances the proliferation of GAT-specific T cells; (ii) the anti-idiotypic serum is effective in priming in vivo LNC which then acquire the capacity to proliferate specifically with GAT in vitro. These results further confirm the existence of idiotype-like determinants on T cells.