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Background: Advanced prostate cancer is a phenotypically diverse disease that evolves through multiple clinical courses. PSA level is the most widely used parameter for disease monitoring, but it has well-recognized limitations. Unlike in clinical trials, in practice, clinicians may rely on PSA monitoring alone to determine disease status on therapy. This approach has not been adequately tested., Methods: Chemotherapy-naive asymptomatic or mildly symptomatic men (n=872) with metastatic castration-resistant prostate cancer (mCRPC) who were treated with the androgen receptor inhibitor enzalutamide in the PREVAIL study were analyzed post hoc for rising versus nonrising PSA (empirically defined as >1.05 vs ⩽1.05 times the PSA level from 3 months earlier) at the time of radiographic progression. Clinical characteristics and disease outcomes were compared between the rising and nonrising PSA groups., Results: Of 265 PREVAIL patients with radiographic progression and evaluable PSA levels on the enzalutamide arm, nearly one-quarter had a nonrising PSA. Median progression-free survival in this cohort was 8.3 months versus 11.1 months in the rising PSA cohort (hazard ratio 1.68; 95% confidence interval 1.26-2.23); overall survival was similar between the two groups, although less than half of patients in either group were still at risk at 24 months. Baseline clinical characteristics of the two groups were similar., Conclusions: Non-rising PSA at radiographic progression is a common phenomenon in mCRPC patients treated with enzalutamide. As restaging in advanced prostate cancer patients is often guided by increases in PSA levels, our results demonstrate that disease progression on enzalutamide can occur without rising PSA levels. Therefore, a disease monitoring strategy that includes imaging not entirely reliant on serial serum PSA measurement may more accurately identify disease progression.

Background: We investigated the impact of skeletal-related events (SREs) on health-related quality of life (HRQoL) in patients with metastatic castration-resistant prostate cancer (mCRPC) in phase III trials of enzalutamide versus placebo., Methods: Patients with mCRPC experiencing at least one SRE during AFFIRM and PREVAIL were assessed for trajectory-adjusted mean change in HRQoL by first SRE using Functional Assessment of Cancer Therapy-Prostate (FACT-P; AFFIRM, three domains, and PREVAIL, nine domains) and EQ-5D (PREVAIL) instruments., Results: First SREs caused HRQoL deterioration in both trials. Spinal cord compression had the largest impact, with clinically meaningful reductions in seven of nine FACT-P domains in PREVAIL and all three in AFFIRM (mean (95% confidence interval (CI)) change in FACT-P total score -16.95 (-26.47, -7.44) and -9.69 (-16.10, -3.27), respectively). In PREVAIL, first SREs caused clinically meaningful declines in EQ-5D utility index, irrespective of category; spinal cord compression had the largest impact (mean (95% CI) change -0.24 (-0.39, -0.08)). In AFFIRM, FACT-P and FACT-General total scores showed clinically meaningful declines after radiation/surgery to bone., Conclusions: SREs were associated with clinically meaningful functional declines in the daily lives of patients with mCRPC. Spinal cord compression had the largest impact on HRQoL.

Gastrointestinal ischemia after allogeneic bone marrow transplantation is a rare complication not well-described in the literature. Herein we retrospectively review charts of four patients who developed intestinal ischemia after allogeneic bone marrow transplantation at our institution. The patients were found to be predominately younger males who presented with nonspecific abdominal pain. Graft-versus-host disease was a common finding among all patients. Laboratory values suggestive of microangiopathy were present in two patients. Obesity and hypertriglyceridemia were cardiovascular risk factors found in these patients. The development of thrombotic microangiopathy and cardiovascular risk factors after allogeneic bone marrow transplantation may predispose patients to gastrointestinal ischemia and may portend a poor prognosis., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Autologous hematopoietic stem cell (HSC) transplant is an effective treatment for patients with hematological malignancies. Unfortunately, 15-30% of patients fail to mobilize a sufficient number of HSCs for the transplant. Plerixafor is now used as a salvage mobilization regimen, with good success. We describe here a risk-based approach for the use of plerixafor, based on the circulating CD34(+) cell count and the CD34(+) cell dose collected after 4 days of G-CSF, that identifies potential poor HSC mobilizers upfront. A total of 159 patients underwent HSC collections using this approach. Of these, 55 (35%) were identified as high risk owing to low CD34(+) cell number or low yield on day 1 of collection, and received plerixafor on the subsequent days of collection. Of the 159 patients, 151 (95%) were able to provide adequate collections with the first mobilization attempt in a median of 1.7 days using this approach. Of the eight who failed initial mobilization, 5 successfully underwent re-mobilization with plerixafor and G-CSF and 3 (1.9%) were mobilization failures. This approach helped to control the overall cost of HSC collections for our BMT program by decreasing the need for remobilization, reducing the number of collection days and avoiding the use of plerixafor in all patients.

Intestinal perforation in the setting of posttransplantation microangiopathy (TMA) is a very rare event and might be considered a terminal event of intestinal microangiopathy (i-TMA), a rather rarely recognized posttransplantation complication, as it overlaps with the more common intestinal graft-versus-host disease (GVHD). Cases of i-TMA described in literature occurred within with first 100 days posttransplantation or shortly thereafter. In this report, we describe a case of late-onset intestinal perforation that occurred in the setting of systemic microangiopathy more than a year after allogeneic transplantation. In our case, the patient poorly responded to treatment secondary to refractory mircoangiopathy., (Published by Elsevier Inc.)

BK virus (BKV) reactivation occurs in 50% of allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Standardized antiviral management of BKV infection has not been established. In order to develop a uniform guideline, a treatment algorithm for the management of symptomatic BKV replication was implemented for our allo-HSCT population. This is a retrospective analysis of patients treated according to the protocol between January 2008 and January 2009. Eighteen patients developed symptomatic BKV replication a median of 43 days after allo-HSCT. All patients had BK viruria and 12 patients had BK viremia in addition to viruria. Patients with isolated viruria were treated with intravenous (IV) low-dose cidofovir (0.5-1mg/kg IV weekly) until symptom resolution. In patients with BK viremia, therapy was continued until virological clearance was achieved in the blood. Four patients also received intravesical instillation of cidofovir per physician discretion. Thirteen of 18 (72%) patients with viruria and 8 of 12 (75%) patients with viremia responded to treatment. Three patients developed transient renal dysfunction. Low-dose cidofovir is safe and effective in allo-HSCT recipients. In absence of randomized prospective data, an institutional algorithmic protocol removes variance in practice pattern and derives data that may be used for research and improved patient care., (© 2010 John Wiley & Sons A/S.)

Blastic plasmacytoid dendritic cell (BPDC) neoplasm is a rare but clinically aggressive tumor known to be derived from the precursors of plasmacytoid dendritic cells (CD123+) with a high frequency of cutaneous and bone marrow involvement. Though majority of the patients initially respond to multi-agent chemotherapy, most would relapse within a year. We hereby report a patient with disseminated cutaneous BPDC with marrow involvement diagnosed by typical histo-pathological and flow-cytometric findings. He was subsequently treated with leukemia type induction regimen followed by allogeneic stem cell transplantation in first complete remission. He is now 18 months posttransplantation with continued remission with full donor chimerism. We recognize that BPDC with marrow involvement behaves like acute myeloid leukemia and aggressive treatment followed by stem cell transplantation may lead to long-term remission in selected cases.

GVHD is partly mediated by host APCs that activate donor T cells. Extracorporeal photopheresis (ECP) can modulate APC function and benefit some patients with GVHD. We report the results of a study using ECP administered before a standard myeloablative preparative regimen intended to prevent GVHD. Grades II-IV acute GVHD developed in 9 (30%) of 30 recipients of HLA-matched related transplants and 13 (41%) of 32 recipients of HLA-matched unrelated or HLA-mismatched related donor transplants. Actuarial estimates of overall survival (OS) at day 100 and 1-year post transplant were 89% (95% CI, 78-94%) and 77% (95% CI, 64-86%), respectively. There were no unexpected adverse effects of ECP. Historical controls receiving similar conditioning and GVHD prophylaxis regimens but no ECP were identified from the database of the Center for International Blood and Marrow Transplant Research and multivariate analysis indicated a lower risk of grades II-IV acute GVHD in patients receiving ECP (P=0.04). Adjusted OS at 1 year was 83% in the ECP study group and 67% in the historical control group (relative risk 0.44; 95% CI, 0.24-0.80) (P=0.007). These preliminary data may indicate a potential survival advantage with ECP for transplant recipients undergoing standard myeloablative hematopoietic cell transplantation.

Allogeneic stem cell transplantation (ASCT) has improved leukemia-free survival (LFS) in many but not all patients with acute leukemia. This is an eight-year follow-up to our previous study showing a survival advantage to patients with an increased gammadelta T cells following ASCT. gammadelta T cell levels were collected prospectively in 153 patients (acute lymphoblastic leukemia (ALL) n = 77; acute myelogenous leukemia (AML) n = 76) undergoing partially mismatched related donor ASCT. Median age was 22 years (1-59), and 62% of the patients were in relapse at transplant. Patient-donor human leukocyte antigen (HLA) disparity of three antigens was 37% in the graft-versus-host disease (GvHD) and 29% in the rejection directions. All patients received a partially T cell-depleted graft using T10B9 (n = 46) or OKT3 (n = 107). Five years LFS and overall survival (OS) of patients with increased gammadelta compared to those with normal/decreased numbers were 54.4 vs 19.1%; P < 0.0003, and 70.8 vs 19.6% P < 0.0001, respectively, with no difference in GvHD (P = 0.96). In a Cox multivariate analysis, normal/decreased gammadelta (hazard ratio (HR) 4.26, P = 0.0002) and sex mismatch (HR 1.45 P=0.049) were associated with inferior LFS. In conclusion, gammadelta T cells may facilitate a graft-versus-leukemia (GvL) effect, without causing GvHD. Further evaluations of this effect may lead to specific immunotherapy for patients with refractory leukemia.

Background: Immunological and clinical effects of post-transplant growth factor administration have not been well studied. This report describes the outcome and immune functions of a total of 50 HLA-matched related donor allogeneic blood stem-cell transplantation patients who received post-transplant G-CSF (10 microg/kg) or placebo., Methods: Immune status, including number of lymphocyte subsets and their functions, and serum immunoglobulin levels and clinical status--including GvHD, rate of relapse, event-free survival, and overall survival--were determined in the patients enrolled in this study., Results: Twenty-eight patients survived 1 year after transplant, and 15 patients had available results to compare immune function by randomization assignment. At 12 months post-transplant, immune parameters in G-CSF versus placebo groups showed no statistically significant differences in number of circulating lymphocyte subsets CD3, CD4, CD8, CD19 and CD56 in the two groups. There was no significant (NS) difference in immunoglobulin IgG, IgA and IgM levels, NK or LAK cell-mediated cytotoxicity levels, and mitogen-induced proliferation between post-transplant G-CSF and placebo group. In addition, the analyses of immune parameters at earlier time-points on Days 28, 100, 180, and 270 revealed that, except for LAK cytotoxicity at Day 100, there was no differences between the two groups. Fourteen of 26 patients are alive in the G-CSF arm and nine of 24 in the placebo arm. Median follow-up of surviving patients is 43 months. Four year overall and event-free survival in the G-CSF and the placebo group were 53% and 35% (NS), and 44% and 36% (NS) respectively. Bacterial or fungal infections were the cause of six of 12 deaths in the G-CSF arm (all bacterial) and of four of 15 deaths in the placebo arm (two deaths from Aspergillus) (P=0.26). Two patients relapsed in the G-CSF arm and three in the placebo arm. Four year cumulative incidences of relapse were 8% versus 13% in G-CSF versus placebo arms, respectively, (NS). Chronic GvHD developed in 14 of 19 100-day survivors after G-CSF (11 extensive stage), and in 17 of 20 (14 extensive stage) in the placebo arm. The 4-year cumulative incidence of chronic GvHD was 56% [95% confidence interval (CI) 24-88%] after G-CSF and 71% (95% CI 48-94%) after placebo; this difference was not statistically significant (log rank P=0.41)., Conclusion: In summary, there were no significant immunological or alterations in clinical benefit of post-transplant G-CSF administration in T-replete allotransplant recipients.

ABX-CBL, an immunoglobulin M murine monoclonal antibody, recognizes CD147 and initiates cell killing through complement-mediated lysis. In a dose-finding trial, 27 patients with steroid-refractory acute graft-versus-host disease (GVHD) received ABX-CBL at 0.01 (presumed no effect dose), 0.1, 0.2, or 0.3 mg/kg per day, and an additional 32 patients were given ABX-CBL at 0.2 or 0.15 mg/kg per day. All patients had undergone allogeneic transplantation for malignant or nonmalignant disorders and received GVHD prophylaxis, generally with methotrexate- and cyclosporine-containing regimens. None responded to methylprednisolone, given for a minimum of 3 days. ABX-CBL was started 20 to 236 (median, 47) days after transplantation; it was given for 7 consecutive days and was followed by 2 infusions per week for 2 more weeks. Among 51 patients evaluable for efficacy, 26 (51%) responded, including 13 with complete responses (CR) and 13 with partial responses (PR). CR lasting 14 days or longer or PR lasting 7 days or longer occurred in 21 (41%; 8 CR, 13 PR) patients, including 19 of 43 (44%) patients who received 0.1 to 0.3 mg/kg ABX-CBL and 2 of 8 (25%) patients given 0.01 mg/kg per day. Myalgias at doses 0.2 mg/kg or greater were dose limiting and resolved without sequelae. Causes of death included organ failure, progressive GVHD, and infection. No death was attributed to ABX-CBL. At 6 months after the initiation of ABX-CBL therapy, 26 (44%) patients were surviving. These results are encouraging. Further studies on the use of ABX-CBL in the management of GVHD are warranted.

Study Objective: To evaluate the pharmacokinetics and use of intravenous human cytomegalovirus immune globulin (CytoGam) in allogeneic bone marrow transplantation (BMT)., Design: Prospective, nonrandomized, nonblinded, single-center study., Setting: University teaching hospital., Patients: Five consecutive patients with hematologic malignancies receiving partially mismatched related donor BMT with a uniform conditioning regimen including total body irradiation and chemotherapy., Intervention: Serum immunoglobulin and cytomegalovirus (CMV) titers were measured before and 24 hours after the first CytoGam infusion on day -6 during the conditioning regimen., Measurements and Main Results: These levels were measured every 5 days, and a second dose was administered when the CMV titer returned to 25-50% of the 24-hour level. The half-life of CytoGam was approximately 7 days., Conclusion: We believe this is the first report of CytoGam's half-life in allogeneic BMT. The information may prove vital in a future study in which the agent's potential beneficial effects can be maximized.

Aim: The use of indomethacin in treatment of hydramnios was evaluated., Subjects & Methods: Twelve patients with symptomatic hydramnios were treated with indomethacin (2.2- 3.0 mg/kg body weight/day)., Results: The treatment was started at a gestational age of 31.17-/+7.94 weeks and continued for 3.74-/+2.3 weeks. Eleven patients responded to the therapy both subjectively and objectively and pregnancies were prolonged by 4.6-/+3.1 weeks (range 0.1-10 weeks). Five women had term deliveries. Six patients had a favourable perinatal outcome. Four patients who had a known congenital anomaly in the foetus, delivered stillborn babies or had an early neonatal death. One patient who did not follow up after commencing therapy delivered a full-term stillbirth. One patient delivered within 1 day of starting therapy. Indomethacin therapy caused no maternal complications., Conclusion: Indomethacin was effective in the management of hydramnios and preventing it's complications.

Allogeneic BMT offers the possibility of cure for a variety of hematopoietic malignancies, but disease relapse remains a major cause of treatment failure. This report describes two cases in which flow cytometric cell sorting (FACS) and molecular chimerism analysis were combined to increase the sensitivity of minimal residual disease (MRD) detection. In the first case this approach was used to demonstrate that a suspicious phenotype was not recurrent leukemia, thus preventing the use of potentially toxic therapy. In the second case the recurrence of a leukemia which was undetectable by conventional analysis was confirmed. The potential benefits of combining these MRD detection methods are discussed.

Patients who relapse post-ABMT are usually resistant to conventional therapy, and a potentially curative therapy with allogeneic BMT is limited due to availability of a matched donor. To assess whether such patients can be salvaged using partially mismatched related donors (PMRD), eight patients age 6-50 years old underwent PMRD-BMT. All patients ALL (n = 3) and AML (n = 5) were in relapse 7-31 months after first BMT. Donors (1-3 Ag mismatch) were selected from family members. Conditioning included TBI, etoposide, Ara-C and cytoxan (n = 3), or busulfan, thiotepa, and etoposide (n = 5). GVHD prophylaxis consisted of partial T cell depletion followed by systemic immunosuppression. All evaluable patients established sustained engraftment by day 18. Severe regimen-related toxicity was evident in the gastrointestinal and hepatic systems (6/8 and 4/8, respectively), the latter associated with poor outcome (P < 0.014). Acute but not chronic GVHD, grade > or = II occurred in 3/7 patients. Four of eight patients are disease-free, maintaining longer remission than following their first BMT (14 vs 9 months). In conclusion, our data shows that PMRD-BMT is a feasible option for patients who relapse post-BMT and use of such alloreactive grafts may be appropriate earlier in the disease course of high risk patients.

TCR-beta (T cell receptor-beta chain) transgenic mice have altered lymphocyte development. TCR-beta transgenic mice are hyporesponsive to alloantigens in vivo and are deficient in gamma delta T cells. In order to begin a study of the relationship between a deficiency of alloreactive gamma delta cells and the defective function of in vivo alloantigen recognition, we analysed the gamma delta T cell development in TCR-beta mice. The presence of the TCR-V beta 8.2 chain transgene is associated with inhibition of gamma chain gene rearrangement. In order to determine how the presence of the TCR-beta transgene affects gamma delta T cell development, gamma delta T cells were studied in the skin, intestine and spleen. TCR-beta mice have dramatically reduced numbers of gamma delta T cells in the spleen and moderately reduced numbers of gamma delta T cells among intestinal intraepithelial lymphocytes. In contrast, these mice have normal numbers of gamma delta dendritic epidermal cells (DEC). These selective deficits could be due to the developmental regulation of transgene transcription during fetal life. We examined transcription of the TCR-beta transgene in the fetal thymus and found that the TCR-beta transgene is first transcribed at high levels on day 16 of fetal life, after DEC have already migrated from the thymus to the epidermis. Furthermore, mRNA from the transgene was detected in DEC, ruling out the formal possibility that DEC bear a gamma delta receptor only because they are incapable of expressing the transgene.(ABSTRACT TRUNCATED AT 250 WORDS)

SENCAR mice, developed by selective breeding for high susceptibility to skin carcinogenesis by initiation with 7,12-dimethylbenz[a]anthracene and promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA), form squamous papillomas in approximately 20% of animals treated repeatedly with TPA, without chemical initiation. DNA from eight skin tumors produced by a TPA-only protocol and four cell lines derived from these tumors was amplified by polymerase chain reaction and analyzed by discriminative oligonucleotide hybridization using oligomers specific for various c-rasHa gene codon 61 sequences. Five tumors and three cell lines had CAA (wild-type) to CGA mutations. In addition, one tumor had a CAA to CTA mutation, for a total of six of eight tumors having an activating mutation at this codon. Two tumors and one cell line had no codon 61 mutations detectable by this method. Since tumors derived from promotion-only protocols presumably originated from constitutively initiated cells, we examined tumor-free skins of untreated newborn and eight-month-old retired breeders and of 78-88-week-old SENCAR mice of both sexes, which were treated with TPA for 10 weeks starting at age 16-28 weeks and were untreated thereafter. Only the wild-type c-rasHa gene codon 61 sequence was seen, suggesting that the constitutively initiated cell population, if present, is below the limit of detection by this method.

Cytokines are believed to cause a number of inflammatory diseases. We have investigated the role of 3 inflammatory cytokines, IL-1, IL-2, and TNF alpha, during graft-versus-host disease (GVHD), a paradigm disease of cytokine dysregulation in vivo. Measuring cytokine mRNA transcripts with a quantitative polymerase chain reaction technique, we demonstrate that IL-1 transcript levels are increased several hundred-fold in GVHD target organs, whereas TNF alpha transcripts increase only 4- to 6-fold. Kinetic studies during the first month after transplant unexpectedly show that GVHD never induces IL-2 transcripts in the skin and only induces IL-2 transcripts in the spleen during the first week, whereas levels of IL-1 transcripts continue to increase throughout the entire 4 weeks. Administration of an IL-1 receptor antagonist after the termination of the IL-2 response and after the establishment of GVHD significantly increases long-term survival, confirming the central role of IL-1 as an effector molecule of GVHD and suggesting new therapeutic strategies for this disorder.

Graft-versus-host disease (GVHD) is known to cause profound dysregulation of the immune system, although its effector mechanisms are poorly understood. We now describe an effector lymphocyte of unusual phenotype in the skin of mice with GVHD. This cell is of donor origin and expresses several T-cell surface proteins including Thy-1, CD2, and CD4 but does not express CD8, CD3, NK1.1, or macrophage antigens. Mononuclear cells of this phenotype are the predominant lymphocyte in the epidermis of mice with GVHD 3 weeks after transplant but are not detected in transplanted mice without GVHD. Isolation and transfer of these lymphocytes into secondary recipients causes epidermal damage characteristic of GVHD. These data demonstrate that CD4+ CD8- CD3- lymphocytes are an important effector population that can be amplified outside the thymus and that can mediate target organ damage of GVHD.

Graft-versus-host disease (GVHD) is the major complication of allogeneic bone marrow transplantation (BMT). Dysregulation of inflammatory monokines such as tumor necrosis factor alpha (TNF alpha) has been noted in both clinical and experimental GVHD. We present evidence that interleukin-1 (IL-1), another inflammatory monokine, is an important mediator of GVHD. Expression of the gene for IL-1 alpha as well as the gene for TNF alpha is increased in the skin of mice with GVHD. Inhibition of IL-1 function by the in vivo administration of IL-1 receptor antagonist (IL-1ra) reduces the immunosuppression and mortality of GVHD without impairing the engraftment of hematopoietic stem cells. GVHD thus appears to be a systemic inflammatory process in which monokines, especially IL-1, appear to be important mediators. Inhibition of IL-1 by IL-1ra represents a novel approach to the understanding and control of GVHD.

Success of programs to screen newborns for sickle cell disease depends on timely follow-up. Education regarding fever and splenic palpation, and initiation of prophylactic penicillin therapy, will reduce morbidity and mortality and should occur prior to 4 months of age. However, contacting parents to permit implementation of care may be difficult, particularly in large urban populations; only nine (36%) of 25 infants recently identified as having sickle cell disease arrived at our institution for initial appointments. Medical providers must be aware of medical and legal obligations related to follow-up of newborns with sickle cell disease to prevent untoward events in "missed cases."

Three lactate-dehydrogenase-deficient mutants of serotype c S. mutans were made by using, as parents, two serotype c strains that produced unusually large amounts of ethanol, acetic acid, and acetoin, and very little lactic acid, when grown in broth containing a limiting amount of glucose. The mutants, obtained with N-methyl-N'-nitro-N-nitrosoguanidine, were stable during 12 weeks of daily subculture in broth. Crude cell-free extracts of the mutants had less than 1% of the LDH-specific activity of their parent strains. The serotype c mutants resembled serotype g mutants in having molar growth yields at least as high as those of their parents. However, in contrast to the g mutants, the c mutants produced cell crops (cell mass per ml medium) that were as high as those of their parent strains.

A case of positive cord blood direct antiglobulin test (DAT) due to anit-Le(a) is described. The infant who was Le(a + b-) had no evidence of hemolytic disease.

A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.