A Phase 1 Trial of Salvage Stereotactic Body Radiation Therapy for Radiorecurrent Prostate Cancer After Brachytherapy

PURPOSE

NCT03253744 is a phase 1 trial with the primary objective to identify the maximum tolerated dose (MTD) of salvage stereotactic body radiation therapy (SBRT) in patients with local prostate cancer recurrence after brachytherapy. Additional objectives included biochemical control and imaging response.

METHODS AND MATERIALS

This trial was initially designed to test 3 therapeutic dose levels (DLs): 40 Gy (DL1), 42.5 Gy (DL2), and 45 Gy (DL3) in 5 fractions. Intensity modulation was used to deliver the prescription dose to the magnetic resonance imaging and prostate-specific membrane antigen-based positron emission tomography imaging-defined gross tumor volume while simultaneously delivering 30 Gy to an elective volume defined by the prostate gland. This phase 1 trial followed a 3+3 design with a 3-patient expansion at the MTD. Toxicities were scored until trial completion at 2 years post-SBRT using Common Terminology Criteria for Adverse Events version 5.0. Escalation was halted if 2 dose limiting toxicities occurred, defined as any persistent (>4 days) grade 3 toxicity occurring within the first 3 weeks after SBRT or any grade ≥3 genitourinary (GU) or grade 4 gastrointestinal toxicity thereafter.

RESULTS

Between August 2018 and January 2023, 9 patients underwent salvage SBRT and were observed for a median of 22 months (Q1-Q3, 20-43 months). No grade 3 to 5 adverse events related to study treatment were observed; thus, no dose limiting toxicities occurred during the observation period. Escalation was halted by amendment given excellent biochemical control in DL1 and DL2 in the setting of a high incidence of clinically significant late grade 2 GU toxicity. Therefore, the MTD was considered 42.5 Gy in 5 fractions (DL2). One- and 2-year biochemical progression-free survival were 100% and 86%, representing a single patient in the trial cohort with biochemical failure (prostate-specific antigen [PSA] nadir + 2.0) at 20 months posttreatment.

CONCLUSIONS

The MTD of salvage SBRT for the treatment of intraprostatic radiorecurrence after brachytherapy was 42.5 Gy in 5 fractions producing an 86% 2-year biochemical progression-free survival rate, with 1 poststudy failure at 20 months. The most frequent clinically significant toxicity was late grade 2 GU toxicity.

A Phase 1 Trial of Focal Salvage Stereotactic Body Radiation Therapy for Radiorecurrent Prostate Cancer

PURPOSE

NCT03253744 was a phase 1 trial to identify the maximum tolerated dose (MTD) of image-guided, focal, salvage stereotactic body radiation therapy (SBRT) for patients with locally radiorecurrent prostate cancer. Additional objectives included biochemical control and imaging response.

METHODS AND MATERIALS

The trial design included 3 dose levels (DLs): 40 Gy (DL1), 42.5 Gy (DL2), and 45 Gy (DL3) in 5 fractions delivered ≥48 hours apart. The prescription dose was delivered to the magnetic resonance- and prostate-specific membrane antigen imaging-defined tumor volume. Dose escalation followed a 3+3 design with a 3-patient expansion at the MTD. Toxicities were scored until 2 years after completion of SBRT using Common Terminology Criteria for Adverse Events, version 5.0, criteria. Escalation was halted if 2 dose-limiting toxicities occurred, defined as any persistent (>4 days) grade 3 toxicity occurring within the first 3 weeks after SBRT and any grade 3 genitourinary (GU) or grade 4 gastrointestinal (GI) toxicity thereafter.

RESULTS

Between August 2018 and May 2022, 8 patients underwent salvage focal SBRT, with a median follow-up of 35 months. No dose-limiting toxic effects were observed on DL1. Two patients were enrolled in DL2 and experienced grade 3 GU toxicities, prompting de-escalation and expansion (n = 6) at the MTD (DL1). The most common toxicities observed were grade ≥2 GU toxicities, with only a single grade 2 GI toxicity and no grade ≥3 GI toxicities. One patient experienced biochemical failure (prostate-specific antigen nadir + 2.0) at 33 months.

CONCLUSIONS

The MTD for focal salvage SBRT for isolated intraprostatic radiorecurrence was 40 Gy in 5 fractions, producing a 100% 24-month biochemical progression free survival, with 1 poststudy failure at 33 months. The most frequent clinically significant toxicity was late grade ≥2 GU toxicity.

Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Local failure after definitive radiation treatment of lymph-node positive prostate cancer: supporting the use of novel imaging techniques to personalize treatment options

Patients with lymph-node positive prostate cancer are often treated with external beam radiotherapy with androgen deprivation therapy¹, but are expected to have a high rate of biochemical failure. Recently, MRI and molecular imaging have afforded the opportunity to elucidate otherwise occult sites of recurrence after conventional imaging. We present an unusual case of local failure within the prostate after definitive radiation treatment of lymph-node positive prostate cancer, in which advanced imaging allowed for a potentially curative salvage treatment option.

Real-world experience with the all-oral, interferon-free regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir for the treatment of chronic hepatitis C virus infection in the German Hepatitis C Registry

Real-world studies are relevant to complement clinical trials on novel antiviral therapies against chronic hepatitis C; however, clinical practice data are currently limited. This study investigated effectiveness and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r)±dasabuvir (DSV)±ribavirin (RBV) for treatment of HCV genotype (GT) 1 and GT4 infection in a large real-world cohort. The German Hepatitis C Registry is an observational cohort study prospectively collecting clinical practice data on direct-acting antiviral therapies. Patients with GT1/4 infection treated with OBV/PTV/r±DSV±RBV were analysed. Effectiveness was assessed by sustained virologic response in 558 patients who reached post-treatment week 12 (SVR12). Safety is reported in 1017 patients who initiated treatment. Of the patients, 892 (88%) had GT1 and 125 (12%) had GT4 infection. Prior treatment experience and cirrhosis were reported in 598 (59%) and 228 (22%) patients, respectively. Overall, SVR12 (mITT) was 96% (486/505) in GT1- and 100% (53/53) in GT4 patients. SVR12 rates were high across subgroups including patients with cirrhosis (95%, 123/129), patients with moderate to severe renal impairment (100%, 34/34), and subgroups excluded from registrational trials like patients ≥70 years (96%, 64/67) and failures to prior protease inhibitor treatment (96%, 46/48). Adverse events (AEs) and serious AEs were reported in 52% (525/1017) and 2% (21/1017) of patients, respectively, and led to treatment discontinuation in 1.5% (15/1017) of patients. OBV/PTV/r±DSV±RBV was effective and generally well tolerated for treatment of HCV infection in clinical practice.

Effect of Prostate Magnetic Resonance Imaging/Ultrasound Fusion-guided Biopsy on Radiation Treatment Recommendations

PURPOSE

Targeted magnetic resonance imaging (MRI)/ultrasound fusion prostate biopsy (MRI-Bx) has recently been compared with the standard of care extended sextant ultrasound-guided prostate biopsy (SOC-Bx), with the former associated with an increased rate of detection of clinically significant prostate cancer. The present study sought to determine the influence of MRI-Bx on radiation therapy and androgen deprivation therapy (ADT) recommendations.

METHODS AND MATERIALS

All patients who had received radiation treatment and had undergone SOC-Bx and MRI-Bx at our institution were included. Using the clinical T stage, pretreatment prostate-specific antigen, and Gleason score, patients were categorized into National Comprehensive Cancer Network risk groups and radiation treatment or ADT recommendations assigned. Intensification of the recommended treatment after multiparametric MRI, SOC-Bx, and MRI-Bx was evaluated.

RESULTS

From January 2008 to January 2016, 73 patients received radiation therapy at our institution after undergoing a simultaneous SOC-Bx and MRI-Bx (n=47 with previous SOC-Bx). Repeat SOC-Bx and MRI-Bx resulted in frequent upgrading compared with previous SOC-Bx (Gleason score 7, 6.7% vs 44.6%; P<.001; Gleason score 8-10, 2.1% vs 38%; P<.001). MRI-Bx increased the proportion of patients classified as very high risk from 24.7% to 41.1% (P=.027). Compared with SOC-Bx alone, including the MRI-Bx findings resulted in a greater percentage of pathologically positive cores (mean 37% vs 44%). Incorporation of multiparametric MRI and MRI-Bx results increased the recommended use and duration of ADT (duration increased in 28 of 73 patients and ADT was added for 8 of 73 patients).

CONCLUSIONS

In patients referred for radiation treatment, MRI-Bx resulted in an increase in the percentage of positive cores, Gleason score, and risk grouping. The benefit of treatment intensification in accordance with the MRI-Bx findings is unknown.

Elevated water temperature increases the levels of reo-like virus and selected innate immunity genes in hemocytes and hepatopancreas of adult female blue crab, Callinectes sapidus

Seasonal changes in water temperature directly affect the aquatic ecosystem. The blue crab, Callinectes sapidus, inhabiting the Chesapeake Bay has been adapted to seasonal changes of the environmental conditions. In this, the animals halt their physiological process of the growth and reproduction during colder months while they resume these processes as water temperatures increase. We aimed to understand the effect of the elevated temperatures on a disease progression of reo-like virus (CsRLV) and innate immunity of adult female C. sapidus. Following a rise in water temperature from 10 to 23 °C, CsRLV levels in infected crabs rose significantly in hemocytes and multiple organs. However, in hemocytes, the elevated temperature had no effect on the levels of three innate immune genes: Cas-ecCuZnSOD-2, CasPPO and CasLpR three carbohydrate metabolic genes: CasTPS, CasGlyP; and CasTreh and the total hemocyte counts (THC). Interestingly, the hemocytes of CsRLV infected animals exposed to 23 °C for 10 days had significantly elevated levels of Cas-ecCuZnSOD-2 and CasTPS, compared to those of the uninfected ones also exposed to the same condition and compared to hatchery-raised females kept at 23 °C. Despite the lack of changes in THC, the types of hemocytes from the animals with high CsRLV levels differed from those of uninfected ones and from hatchery animals kept at 23 °C: CsRLV-infected crabs had hemocytes of smaller size with less cytosolic complexity than uninfected crabs. It therefore appears that the change in temperature influences rapid replication of CsRLV in all internal tissues examined. This implies that CsRLV may have broad tissue tropism. Interestingly, the digestive tract (mid- and hindgut) contains significantly higher levels of CsRLV than hemocytes while hepatopancreas and ovary have lower levels than hemocytes. Innate immune responses differ by tissue: midgut and hepatopancreas with upregulated Cas-ecCuZnSOD-2 similar to that found in hemocytes. By contrast, hepatopancreas showed a down-regulated CasTPS, suggesting carbohydrate stress during infection.

Real-life experience with first generation HCV protease inhibitor therapy in Germany: The prospective, non-interventional PAN cohort

BACKGROUND AND AIMS

The efficacy and safety of peginterferon alfa-2a (PEG-IFN) plus ribavirin (RBV) and either boceprevir (BOC) or telaprevir (TVR), and physician adherence to treatment algorithms were evaluated in patients included in an ongoing non-interventional study (PAN) enrolling adults with chronic hepatitis C virus (HCV) infection managed in German office-based practices.

METHODS

The analysis included HCV genotype 1-infected, treatment-naïve and treatment-experienced patients treated with BOC or TVR. Demographic, treatment history, virological response, safety, and patient management data were collected.

RESULTS

Of a total 1087 patients, 58.1 % achieved sustained virological responses (SVR). Response rates were higher in treatment-naïve (BOC 55 %; TVR 63.4 %) and prior relapse patients (BOC 63.2 %; TVR 74.5 %) versus previous null-responders (BOC 14.3 %; TVR 25 %). The most commonly reported adverse event overall was fatigue (60.6 %); 45.8 % patients experienced hemoglobin < 10 g/dL. Patients with cirrhosis had lower rates of SVR versus those without (42.9 % vs. 60.7 %, respectively), and had a higher incidence of serious adverse events (SAEs) (16.7 % vs. 8.6 %, respectively) and treatment discontinuation (44.6 % vs. 25.2 %, respectively). According to recommended response-guided treatment algorithms, about 70 % of patients were managed appropriately, 11/10 % (BOC/TVR) received unnecessarily extended therapy, and 19/7 % (BOC/TVR) received inappropriately shortened therapy.

CONCLUSIONS

The efficacy and safety of BOC- and TVR-based triple therapy in this large, "real-world" cohort were largely comparable to that reported in pivotal clinical trials, although SVR rates were lower overall. Recommended futility or treatment extension rules were violated in a substantial proportion of patients with potential implications for response, adverse events and costs.

BODIPY-phenylacetylene macrocycle motifs for enhanced light-harvesting and energy transfer applications

BODIPY-phenylacetylene macrocyclic hybrids are reported, where energy transfer is observed from the phenylacetylene unit to the BODIPY core.

Significant impact of patient age on outcome after liver resection for HCC in cirrhosis

OBJECTIVE

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The majority of patients with HCC have cirrhosis. Beside liver transplantation the resection is an established curative treatment option for patients with HCC in cirrhosis. However, the long term success is limited by a high tumor recurrence rate. Furthermore, by many patients surgical resection is restricted by poor liver function. The purpose of this study was to investigate the influence of patient age on long term outcome after liver resection in patients with HCC in cirrhotic liver. Further purpose was to define the potential prognostic factors.

PATIENTS AND METHODS

The outcome of 141 patients with liver cirrhosis after curative resection was analyzed using a prospective database. Only patients with postoperative histological assurance of HCC were included in the database. Patients with fibrolamellar HCC were excluded.

RESULTS

By patients below 70 years of age the 1-, 3- and 5-year survival rates were 78.5%, 56.5% and 47.1%. By patients over 70 years the 1-, 3- and 5-year survival rates were 59.9%, 40.3% and 6.7%. Cumulative survival of the total collective was significant influenced by patient age, Clavien grade, positive lymph vessels, mechanical ventilation and BMI. The overall postoperative morbidity was 44.7%. No intraoperative deaths were observed, but 11 patients (8 older than 70 and 3 younger than 70 years) died during the hospital stay. Clavien grade correlated with preoperative increased GGT, need for intraoperative blood and fresh frozen plasma transfusion.

CONCLUSIONS

Patient age and postoperative complications are more relevant for the outcome than many tumor factors, especially by patients over 70 years of age. In contrast, the prognosis of patients below 70 years of age is significantly better and a 5 year survival rate above 50% could be shown in our patients. However, by carefully selected elderly patients with HCC in cirrhosis an acceptable long term survival is reachable.

Treatment of hepatocellular carcinoma with sorafenib - focus on special populations and adverse event management

Sorafenib, a receptor tyrosine kinase-inhibitor with anti-proliferative and anti-angiogenic activity, is currently the only approved systemic treatment for patients with hepatocellular carcinoma. It inhibits downstream signaling of VEGFR-2, PDGFR, c-Kit receptors and BRAF. Over the last four years comprehensive experience with sorafenib in this indication has been accumulated. In this review we discuss the current data on the use of sorafenib in patients with advanced HCC including special patient populations such as patients with impaired liver function, patients after transplantation, and others. The most frequent side-effects and practical tips on how to manage them are discussed in detail. In addition, we summarize the current experimental data on the use of sorafenib in combination treatment, e. g., together with transarterial chemoembolisation or other targeted agents.

Ischemic-type biliary lesions after ortothopic liver transplantation: diagnosis with magnetic resonance cholangiography

PURPOSE

To determine the accuracy of magnetic resonance (MR) cholangiography for detection of ischemic-type biliary lesions (ITBL) following orthotropic liver transplantation (OLT).

MATERIALS AND METHODS

MR cholangiography was performed in 16 patients with established diagnosis of ITBL following OLT. Two blinded observers reviewed all images in consensus and recorded diagnostic features including presence of intrahepatic and extrahepatic biliary strictures, dilatations, beading, pruning, and filling defects. Sensitivity, specificity, positive predictive value, and accuracy of MR cholangiography were calculated. Final diagnosis was established at endoscopic retrograde cholangiography.

RESULTS

MR cholangiography proved to be a valuable tool for the detection of stenoses and dilatations in patients with ITBL following OLT. Sensitivity of the different diagnostic features ranged between 71% and 100%, specificity between 50% and 100%, accuracy between 81% and 100%, and positive predictive value between 87% and 100%.

CONCLUSION

MR cholangiography proved to be an accurate imaging technique to noninvasively detect biliary complications in patients with ITBL after OLT.

CD154, a marker of antigen-specific stimulation of CD4 T cells, is associated with response to treatment in patients with chronic HCV infection

CD4 T-cell function is crucial for the eradication of HCV, and insufficient function is observed in chronic carriers. The monitoring of T-cell responses is complicated by the scarcity of antigen-specific T cells and the relative inefficiency of virus-specific T cells to produce effector cytokines. CD154 is a marker of activation expressed on T cells induced through their T-cell receptor. We analysed CD4 T-cell responses in 72 patients with chronic or resolved HCV infection (23 treatment naïve, 49 treatment experienced, including 16 who had achieved a sustained response). In an additional prospective protocol, 20 of the chronically infected patients were analysed before and after 8-12 weeks of combination therapy with peg-interferon-α and ribavirin. T-cell responses were measured by detecting the expression of CD154 and Th1 cytokines after stimulation with recombinant HCV proteins and were correlated with pretreatment status and outcome of therapy. Broader T-cell responses were observed in treatment naïve than in experienced patients, while the outcome of a preceding therapy regimen did not influence T-cell responses. In the prospective cohort, an on-treatment increase in CD154+ cytokine- T-cell activity was associated with response to treatment, while a decrease was observed in nonresponders. Stronger antigen-independent activity of CD154+ cytokine+ T cells was observed in responders than in nonresponders. Our data indicate that CD154 as a marker of activation of CD4 T cells is a suitable tool for the analysis of T-cell responses in patients with HCV infection.

[Strategies for the prevention of hepatocellular carcinoma in the context of chronic viral hepatitis]

Liver cirrhosis induced by HBV and HCV infections is the main risk factor for the development of hepatocellular carcinoma (HCC). Therefore, prevention of chronic infection with hepatitis viruses and prevention of the development of cirrhosis are essential for the primary prevention of HCC. A consequent vaccination program for HBV is suitable to reduce the rate of infections and the HCC-associated mortality. Since no vaccine is available for HCV, the reduction of risky behaviour and the improvement of hygiene standards are the mainstays for prevention of HCV. An efficient antiviral therapy aimed at the durable suppression of the viral load reduces the risk of progression to cirrhosis and development of HCC in precirrhotic stages of chronic HBV or HCV infections. In cirrhotic patients, the risk of developing HCC remains elevated even if a sustained virological response is achieved, thus requiring further screening with the intention of the early detection of HCC. It is too early to judge whether virological nonresponders profit from continued antiviral therapy. Therefore, the early diagnosis of chronic HBV or HCV infection is the single most important factor for the prevention of HCC. Secondary prevention after surgical resection or local ablative therapy may reduce the frequency of late recurrence. Liver transplantation is today the most effective measure of secondary prevention for selected patients with HCC. Due to its antiproliferative effects, the immunosuppressive drug sirolimus may play a role for secondary prevention of HCC following transplantation.

Association of TLR7 single nucleotide polymorphisms with chronic HCV-infection and response to interferon-a-based therapy

An efficient immune response against hepatitis C virus (HCV) is necessary to clear infection. As HCV is a single-stranded RNA virus, a role for TLR7 in the immune response against HCV is possible, and early clinical studies have demonstrated an antiviral effect of TLR7 stimulation. We tested the hypothesis that genetic variations of TLR7 are associated with chronic HCV-infection and outcome of therapy. The prevalence of three TLR7 variations was analysed in 978 patients with chronic HCV-infection, 898 patients with chronic liver disease of other aetiologies, and in 203 healthy controls. The prevalence of TLR7 variations was correlated with the response to interferon-alpha-based treatment in 544 patients with chronic HCV-infection. We analysed TLR7 polymorphisms by melting curve analysis and reconstructed haplotypes. The c.32A>T variation was over-represented in female patients with chronic HCV-infection compared to patients with other chronic liver diseases and to healthy controls (P < 0.05). In contrast, c.2403 G>A was less prevalent in male patients with chronic HCV-infection (P < 0.05). No association was observed for the third variant, c.1-120T>G. Haplotype analysis confirmed the differential distribution of TLR7 variants between the groups. Within the group of female patients with chronic HCV-infection, c.32T was predictive of an unfavourable outcome of interferon-alpha therapy (P < 0.05). This study reports the association of TLR7 variants with chronic HCV-infection and with the response to interferon-alpha therapy in patients with chronic HCV-infection. Our results suggest that variations of TLR7 impair the immune response to HCV and imply a gender-specific effect of this X-chromosomal variation.

Expression of a recombinant preproendothelin-1 gene in arteries stimulates vascular contractility

Endothelin (ET)-1 is a potent vasoconstrictor peptide that is elevated in cardiovascular diseases. However, the biological function of ET-1 gene expression within arteries in vivo has not been determined. The effects of ET-1 gene expression were investigated using gene-transfer methods on porcine vascular cells in vitro and porcine arteries in vivo. Transfection of vascular cells with a vector encoding for human preproendothelin-1 cDNA (pVR-ppET) resulted in significant increase in active ET-1 levels in culture supernatant compared with nontransfected cells (P < 0.05). This supernatant contracted rat aortic strips at concentrations 10-fold lower than synthetic ET-1 protein, which was inhibited by the ET-A receptor antagonist BQ-123. Transfection of pVR-ppET into pig iliofemoral arteries resulted in an increase in contractile responses to angiotensin I compared with control vessels (P < 0.05), in contrast to serotonin, phenylephrine, synthetic ET-1, and angiotensin II. A mitogenic effect of recombinant ET-1 on intimal cell growth was not observed. These findings demonstrate that expression of a recombinant ET-1 gene in vivo augments vascular contractility due to an increased sensitivity to angiotensin I, suggesting a role for ET-1 in the pathogenesis of cardiovascular diseases.

Interleukin-10 increases Bcl-2 expression and survival in primary human CD34+ hematopoietic progenitor cells

Bcl-2 expression has been shown in hematopoietic progenitor cells. Through the use of Bcl-2 specific antisense oligonucleotides we herein report the biologic importance of Bcl-2 expression in primary human CD34+ hematopoietic progenitor cells committed to the myeloid lineage. In bone marrow or peripheral blood derived CD34+ cells Bcl-2 specific antisense decreased cell survival and inhibited the outgrowth of mixed myeloid colonies. A short-term overnight pretreatment of CD34+ cells with 25 mumol/L of Bcl-2 antisense in liquid culture completely ablated the growth of granulocyte-macrophage colony-forming cells (GM-CFC) in a subsequent 14 days methylcellulose colony assay. Control experiments using corresponding Bcl-2 sense or nonsense oligonucleotides did not significantly impair cell survival or growth of GM-colony-forming unit. Western blot analyses revealed the Bcl-2 antisense dependent inhibition of expression of the Bcl-2 protein in CD34+ progenitor cells. Furthermore, regulation of Bcl-2 expression by various cytokines including interleukin-10 (IL-10) was studied. IL-10's effects on the formation of mixed myeloid colonies were examined in the absence or presence of Bcl-2 specific antisense. In the absence of Bcl-2 antisense IL-10 significantly extended the colony forming potential of mixed myeloid colonies to 14 days. In the presence of Bcl-2 antisense rhIL-10 completely restored GM-CSF driven colony growth. Fluorescent microscopy, Western blot analysis, and reverse transcriptase-polymerase chain reaction revealed the IL-10 dependent increase in cellular expression of Bcl-2 protein and Bcl-2 mRNA transcripts in CD34+ cells. Thus these results show that Bcl-2 expression is necessary for the formation of GM-CSF-dependent colony growth in vitro and that rhIL-10 increases Bcl-2 expression and survival in primary human CD34+ hematopoietic progenitor cells that are committed to the myeloid lineage.

Umbilical cord blood: an alternative to the transplantation of bone marrow stem cells

Recent in vitro analyses of human UCB have demonstrated the potential of UCB as a source for haematopoietic stem and progenitor cell harvest. Clinical data have further indicated that UCB can be given in vivo to fully and partially HLA-matched siblings or non-familial recipients for marrow reconstitution in genetic disorders as well as malignancies. In comparison to adult peripheral blood, UCB displayed decreased immune responses to alloantigens and was enriched in the numbers of CD34+ progenitor cells with high proliferative and long-term marrow reconstituting potential. Cord blood banks now store large transplantable resources of UCB that are analysed with respect to immunological parameters. Cryopreserved UCB cells may fill the gap in finding a stem-cell transplant for patients who lack a matched related or unrelated donor when a bone marrow transplant is needed.

Serological (Em2-ELISA) and parasitological examinations of fox populations for Echinococcus multilocularis infections

Serum or body fluid samples of 1,006 foxes were investigated in an ELISA for antibodies against a highly sensitive and specific antigen (Em2-antigen) of Echinococcus multilocularis. Parasitological examinations of the intestines and simultaneous serological examinations were carried out in 505 foxes: A group of 98 blue foxes (Alopex lagopus) from Norwegian fox farms did not contain intestinal stages of E. multilocularis and was clearly sero-negative in Em2-ELISA. On the other hand in red foxes (Vulpes vulpes) originating from European areas known to be endemic for E. multilocularis the following average prevalence rates were found: 244 foxes from Southern Germany, E. multilocularis prevalence 55% and sero-prevalence 60%; 139 foxes from Austria, E. multilocularis prevalence 4% and sero-prevalence 12%. Serological identification of individual foxes with or without intestinal E. multilocularis infection was not possible. Only serological (no parasitological) examination in 402 foxes originating from endemic areas in Switzerland resulted in a sero-prevalence rate of 37%. Sero-prevalence was only 6% and 4% in 54 and 26 other foxes, respectively, originating from Swiss and German areas where E. multilocularis has not yet been reported. Negative control Norwegian (farmed) silver foxes (n = 43) were all sero-negative. The specificity of the Em2-ELISA was confirmed by negative Em2-serologies with sera from dogs infected with intestinal and tissue dwelling helminth species (with the exception of two from 24 dogs infected with E. granulosus).(ABSTRACT TRUNCATED AT 250 WORDS)

Immunogenic epitopes of the p55 chain of the IL-2 receptor. Relationships to high-affinity IL-2 binding and modulation of the p55 chain

Monoclonal antibodies were used to determine the relationships between epitopes on the p55 chain of the IL-2 receptor and high-affinity IL-2 binding. Five monoclonal antibodies to the human P55 chain of the IL-2 receptor were induced by immunizing mice with murine L cells that were transfected with human p55 cDNA. Since the p55 chain is the only human antigen expressed on these cells, all antihuman MABs thus generated were directed against this molecule. These antibodies were used to map epitopes on the p55 chain and determine their relationship to high-affinity IL-2 binding. Extensive flow cytometric studies with these MABs and a large panel of other anti-p55 MABs revealed three major patterns of competition. Type I MABs compete with anti-Tac extensively but not with antibodies of other groups. Type II MABs do not block anti-Tac but do block 7E11. Type III MABs do not block either type I or type II antibodies. 125I-IL2 competition studies under high-affinity conditions revealed that types I and II MABs inhibit IL-2 binding. Type III MABs can be resolved into two subgroups, one that inhibits IL-2 binding and one that does not. Together these data suggest that there are at least four distinct immunogenic epitopes on the human p55 chain, with three epitopes related to IL-2 binding. The competitive component evident by a change in Kd on the Scatchard plots suggests that all three epitopes are close to or part of the IL-2-binding site of the p55 chain. The noncompetitive component, as evidenced by the lower number of high-affinity IL-2 receptors induced by these antibodies, suggests that the same epitopes are also close to the site(s) of interaction between the p55 and p70 chains to form the high-affinity receptor. These studies indicated that the IL-2-binding site and site of interaction between the p55 and p70 chains are close together or identical. Modulation studies revealed that one type II antibody (7E11) modulates the p55 chain in the absence of IL2 and the p70 chain, thus revealing that modulation of the p55 chain can occur by an active process, and not merely passively comodulate by the p70 chain upon IL-2 binding. Modulation of the p55 chain alone has no proliferative effect on IL-2-responsive T lymphoblasts. Potentially this antibody-dependent modulation may be used to deliver toxin to activated lymphocytes.

[The importance of the position of the adenosine linkage in NAD+ for its coenzyme activity via lactate dehydrogenase (author's transl)]

We report on the chemical preparation of the NAD+ analog P1, P2-(5'-beta-nicotinamideribofuranosyl-3"-adenosyl)-diphosphate (N3"AD+) by applying the 1,1'-carbonyldiimidazole activation method. The importance of how adenosine is linked to the nicotinamide mononucleotide phosphoriboride (NMNPR+) moiety is discussed with respect to the coenzyme activity in the lactate dehydrogenase catalyzed reaction.

beta-Nicotinamide-alpha-adenine dinucleotide. Synthesis and properties of a coenzyme analog

It was not possible to synthesize beta-nicotinamide-alpha-adenine dinucleotide (NalphaAD) via the NAD pyrophosphorylase-catalyzed reaction of beta-nicotinamide mononucleotide and alpha-adenosine-5'-O-triphosphate. It was therefore prepared by reacting a mixture of beta-nicotinamide mononucleotide and alpha-adenosine-5'-O-monophosphate in aqueous pyridine, using N,N'-dicyclohexylcarbodiimide as condensing agent. NalphaAD can replace NAD in the lactate-dehydrogenase-catalyzed oxidation of lactate to pyruvate with LDH 4M from hog muscle as well as LDH 4H from pig heart. Km values are found to be about one order of magnitude higher for NalphaAD than for NAD. The turnover number for NalphaAD with LDH 4H is similar to that of NAD (95%), whereas it is reduced to one third (35%) in the reaction with LDH 4M. Experiments findings are discussed on the lines of a NAD-equivalent conformation of NalphaAD in the holoenzyme complex.