Feasibility of bremsstrahlung dosimetry for direct dose estimation in patients undergoing treatment with 90Y-ibritumomab tiuxetan.

PURPOSE: Radioimmunotherapy with (90)Y-ibritumomab tiuxetan has been used successfully used in the treatment of CD20-positive non-Hodgkin's lymphoma (NHL). Pretherapy imaging with (111)In-ibritumomab tiuxetan has been used in provisional dosimetry studies. Posttherapy imaging of (90)Y-ibritumomab tiuxetan for clinical use is appealing as it would simplify the data acquisition process and allow measurements of actual doses absorbed during treatment. METHODS: The study included 29 patients with non-Hodgkin's lymphoma, of whom 16 (group I) received a pretherapy (111)In-ibritumomab tiuxetan diagnostic study and (90)Y-ibritumomab tiuxetan treatment 1 week later, and 13 (group II) received only (90)Y-ibritumomab tiuxetan treatment. Planar imaging and blood sampling were performed in all patients. The doses absorbed by organs at risk were calculated using a whole-body average attenuation correction factor (relative dosimetry approach) and, in the case of the (111)In-ibritumomab tiuxetan image sets, also using organ-specific attenuation correction factors (absolute dosimetry method). Red marrow absorbed doses were based on gamma counting of blood samples. RESULTS: The estimated red marrow absorbed doses from (111)In and (90)Y data were equivalent. In all cases, the doses absorbed by organs at risk were found to be within prescribed limits. The relative dosimetry approach applied to both the (90)Y and (111)In data significantly underestimated the doses relative to those obtained with the (111)In absolute dosimetry method which is generally accepted as the reference method (MIRD 16). In the case of (111)In, the relative dosimetry approach values were highly correlated (R(2) = 0.61) with the reference method values. Relative dosimetry estimates may be adjusted multiplying by a correction factor of 2.8. The (90)Y-ibritumomab tiuxetan relative dosimetry data correlated poorly with the reference method values (R (2) = 0.02). CONCLUSION: Based on patient-specific dosimetry, the administered activity may be increased by an average factor of 2.4, indicating that most patients could be undertreated. The relative dosimetry approach based on planar imaging largely underestimates doses relative to reference values. Dosimetry based on planar bremsstrahlung imaging is not a dependable alternative to (111)In dosimetry.

JURL-MK1 (c-kit(high)/CD30-/CD40-) and JURL-MK2 (c-kit(low)/CD30+/CD40+) cell lines: 'two-sided' model for investigating leukemic megakaryocytopoiesis.

Two novel cell lines (JURL-MK1 and JURL-MK2) have been established from the peripheral blood of a patient in the blastic phase of chronic myelogenous leukemia. The cells grow in a single cell suspension with doubling times of 48 h (JURL-MK1) and 72 h (JURL-MK2). Cytogenetic analysis has shown that JURL-MK1 is hypodiploid whereas JURL-MK2 is near triploid and that both cell lines retain t(9;22). Moreover, JURL-MK1 and JURL-MK2 have a bcr/abl-fused gene with the same junction found in the patient's fresh cells, and both cell lines express the b3/a2 type of hybrid bcr/abl mRNA. The morphology and immunophenotype of these cell lines are reminiscent of megakaryoblasts. In both lines, a limited but consistent percentage of cells expresses gpIIbIIIa (CD41a), gpIIIa (CD61) and CD36, with no expression of gplb (CD42b), glycophorin A, hemoglobin and CD34. Both cell lines are clearly positive for CD33, CD43, CD45RO and CD63, while CD13, CD44, CD54, CD30 and CD40 are specific features of JURL-MK2. Among cytokine receptors, CD117/SCF-R is strongly displayed by a large fraction of JURL-MK1 cells but is hardly detectable on about 20% JURL-MK2 cells. Both cell lines are clearly positive for CD25/IL2R alpha, while a marked expression of CD116/GM-CSF-R and CDw123/IL3R alpha is restricted to JURL-MK2. Induction of cell differentiation in vitro has demonstrated that TPA is able to modulate the JURL-MK1 phenotype, causing an increased expression of platelet-associated antigens. The JURL-MK2 phenotype is easily modulated by both TPA and DMSO, which cause an increased expression of CD41a and CD117 accompanied by a decreased expression of CD30. Proliferation studies demonstrated that JURL-MK1 cell growth is enhanced by stem cell factor, while JURL-MK2 proliferation is unaffected by this cytokine. JURL-MK1 and JURL-MK2 are two novel cell lines with divergent biological features, representing a 'two-sided' model for investigating new aspects of megakaryocytopoiesis.

HCV and tumors correlated with immune system: a case-control study in an area of hyperendemicity.

Hepatitis C virus (HCV) is a RNA virus that cannot be integrated with the host genome; it can, however, exert its oncogenetic potential indirectly by contributing to the modulator effects of the host immune system, probably through a capacity to elude the immune system. We have carried out a case controlled study on tumors correlated with the immune system (multiple myeloma, non-Hodgkin lymphoma and Hodgkin disease) and HCV, in a high prevalence area. The relationship between each cancer and HCV infection was assessed by means of odds ratios (ORs) and corresponding 95% confidence intervals. Risks were greater for B-cell non-Hodgkin lymphoma (OR=3.7, 95%CI, 1.9-7.4, P=0.0001) and multiple myeloma (OR=4.5, 95%CI, 1.9-10.7, P=0.0004). Our study is particularly important for public health, since it shows that during the coming years in the South of Italy, because of the high prevalence of HCV, there are good reasons to expect not only an increase of liver cancer, but also an increased incidence of great number of tumors correlated with the immune system.

A study of some pathogenetic aspects of bovine viral diarrhea virus infection.

The cytopathic (CP) strain TVM-2 of bovine virus diarrhea virus (BVDV) induced in calves a severe disease, whereas the calves inoculated with the non-cytopathic (NCP) New York-1 strain, remained clinically normal. When calves were immunosuppressed with dexamethasone (DMS) they underwent an overt, generally fatal disease. This result was obtained with either the CP and the NCP strain of BVDV. It was speculated that the immunosuppressive activity of BVDV could be a property peculiar to certain isolates of the virus.

Optic nerve involvement in acute lymphoblastic leukemia.

Leukemic infiltration of the optic nerve is rare. We describe the diagnostic assessment and the outcome in two adult patients suffering from acute lymphoblastic leukemia with T phenotype. In both cases the leukemic involvement of the eye was observed as an isolated extramedullary relapse followed after several months by hematological relapse. CT and MRI scans were negative, while an A-scan echography of the eye clarified the diagnosis. Early radiotherapy caused recovery of visual acuity in one case. A-scan echography is the most sensitive investigation for the early recognition of ocular localization in acute leukemias.

A phase II trial on alpha-interferon (alpha IFN) effect in patients with monoclonal IgM gammopathy.

Waldenström's macroglobulinemia (WM) is an incurable disorder of B cells. Following occasional reports of response to alpha interferon (IFN) and in view of its effectiveness in hairy cell leukemia, we tested this agent in a relatively large group (n = 88) of patients who had an IgM monoclonal component (MC) greater than 10 g/l. Thirty eight patients had a MC > 30 g/l and were classified as Waldenström's macroglobulinemia (WM), while fifty had either WM in an early stage or an IgM monoclonal gammopathy of undeterminated significance (all of them operationally classified as IgM-MGUS). All patients received IFN 3 MU/day for one month and then 3 times/week. Response to treatment was mainly based on MC reduction in two consecutive determinations (> 50%: major response; 25-50%: minor response). Of 36 evaluable WM patients, 12 had a major and 6 a minor response; of 41 evaluable IgM-MGUS patients, 2 had a major and 6 a minor response. In WM patients with a major response, MC reduction was associated with disappearance of hyperviscosity symptoms, raised Hb level and reduced bone marrow lymphoplasmacytosis. At the dose used, tolerance was excellent in the majority of patients; only 15% withdrew from the study due to side effects. Although single cases and very small series have already been reported, no large study collecting quantitative data on the effects of alpha IFN in WM has been published so far. Our results suggest that IFN treatment is not indicated for patients with a low monoclonal component, while it is of clinical benefit in about 50% of patients with IgM > 30 g/l.

Immunosuppression as a factor in allowing mucosal disease to occur.

In order to verify the role of immunosuppression in the pathogenesis of Bovine Viral Diarrhea Virus (BVDV) infection, two experiments have been carried out. In one experiment, calves previously infected with cytopathogenic (CP) or non-cytopathogenic (NCP) BVDV were treated with dexamethasone (DMS) 30 days later. In the other experiment, calves were simultaneously exposed to BVDV infection and to DMS treatment. In both experiments the DMS treated calves developed a more serious disease which in one calf was fatal. It was speculated that immunosuppression represents one of the most significant "key factors" in the occurrence of the bovine viral diarrhea/mucosal disease in cattle.

The vaccination and challenge with bovine viral diarrhea virus (BVDV) of calves previously infected with a non-cytopathic BVDV.

Four calves were infected with noncytopathic (NCP) New York-1 strain of bovine viral diarrhea virus (BVDV). During the observation period of one month the calves remained clinically normal but the virus was repeatedly recovered from their pharyngeal swabbings and blood. Thirty days following infection the four calves were vaccinated, together with two uninfected calves, with a modified-live vaccine containing cytopathic (CP) BVDV, infectious bovine rhinotracheitis virus and parainfluenza-3 virus. No detrimental effects were observed after vaccination. Forty-three days after vaccination the calves were challenged by exposure either with the CP TVM-2 strain or the NCP New York-1 strain of BVDV. The vaccinated calves remained healthy throughout the 60-day observation period.

A study on neonatal calf diarrhea induced by rotavirus.

This review summarizes the results of a study on rotaviruses isolated from calves affected by neonatal diarrhea. The results indicated that rotavirus infection is widespread and supported the evidence for an etiologic role of these viruses in neonatal diarrhea. Differences in virulence among bovine rotaviruses appeared also to be confirmed. Conventionally reared calves were fully susceptible to the experimental infection induced by rotaviruses originating from heterologous hosts, i.e. monkeys, pigs and rabbits. When rotavirus strains of bovine, simian and rabbit origin were compared by cross neutralization tests, it was found the simian and porcine strains were indistinguishable and both appeared to relate antigenically to the bovine strain. Finally, it was proven that feeding newborn calves with colostrum and first milk of their dams, previously vaccinated with an inactivated adjuvanted rotavirus vaccine, could prevent the neonatal diarrhea from occurring.

Further studies on passive immunization of newborn calves against rotaviral infection.

An inactivated rotavirus vaccine was prepared with an adjuvant which gives a water-in-oil emulsion. The vaccine when injected into cows in their last month of pregnancy, proved to be as effective as the traditional vaccine, prepared with the Freud's incomplete adjuvant, in enhancing the lactogenic immunity. Thus, feeding experimentally infected calves with colostrum and first milk from vaccinated cows prevented diarrhea and reduced significantly rotavirus shedding. Because of its low grade viscosity the water-in-oil emulsifier facilitates inoculation of the vaccine and is therefore recommended as an adjuvant in the preparation of inactivated rotavirus vaccine.

A serologic survey of bovine rotavirus infection in Italy.

Serum neutralization tests conducted by microtiter procedure on 2970 serum samples from calves, heifers and adult cows from representative regions of Italy indicate that rotaviruses, and the infection which they cause, existed in Italy long before the virus was isolated. At the present time the infection is distributed fairly uniformly throughout the cattle population with both sexes and all age groups being equally susceptible.

A study of some biologic properties of Bovid herpesvirus-4.

This article summarizes the results of a study on several strains of Bovid herpesvirus-4 (BHV-4), isolated from cattle. The study had several objectives, namely, to verify (a) the disease-causing potential of the virus, (b) the possibility by BHV-4 to induce a latent infection in the natural host and (c) the entity of the relationships among strains of the virus isolated from different disease syndromes. The following data were obtained: (1) All strains tested were able to replicate in experimentally infected calves; however, only one strain (85/BH 16TV) caused an overt systemic disease. (2) The nervous system as well as the lymphoid structures appeared to be the target organs for replication of the virus. (3) BHV-4, like other herpesviruses, was able to establish latent infection in cattle. (4) When two strains of the virus, isolated from cattle affected by different disease syndromes, i.e. respiratory disease (strain DN-599) or vulvovaginitis (strain 85/BH 16TV), respectively, they resulted to be closely related to each other. In particular, they revealed a similar DNA pattern and both strains were able to cause respiratory disease in calves. Moreover, the two viral strains were mutually protective in that calves were generally found to be refractory to challenge inoculation with either the homologous or the heterologous virus. (5) All BHV-4 strains tested generally failed to evoke a significant production of neutralizing antibody in the experimental calves.

A serological comparison of some animal herpesviruses.

Bovine herpesvirus 1 (BHV-1) isolates (Cooper-type strain 4975 and Oxford) were compared in neutralization tests with the bovine herpesvirus 4 (BHV-4) isolate (85/16 TV) and the herpesviruses of red deer (D2839/1) and goats (E/CH). Hyperimmune antiserum was prepared in rabbits against the plaque-selected viruses and endpoint and kinetic neutralization test were made. BHV-4 was clearly different from the other four viruses. The closely-related BHV-1 strains were also related in these tests to the red deer herpesvirus. The Oxford strain seemed rather closer antigenically than the Cooper-type strain to the red deer herpesvirus. Antiserum to the caprine herpesvirus failed to neutralize either BHV-1 strain or red deer virus, but antiserum to the Cooper-type and red deer herpesviruses did neutralize caprine virus to a limited extent.

Neonatal calf diarrhea induced by rotavirus.

This presentation summarizes the results of a comprehensive study on rotaviruses isolated in Italy from calves and rabbits affected by neonatal diarrhea. The results clearly indicated that rotavirus infection is widespread and supported the evidence for an etiologic role of these viruses in neonatal diarrhea. The evidence of differences in virulence among bovine rotaviruses appeared also to be confirmed. Conventionally reared calves were fully susceptible to the experimental infection induced by three rotaviruses originating from heterologous hosts, i.e. monkeys, pigs and rabbits, respectively. When rotavirus strains of bovine, simian, porcine and rabbit origin were compared by cross neutralization tests, it was found the simian and porcine strains were indistinguishable and both appeared to relate antigenically to the bovine strain. On the other hand, a reciprocal antigenic correlation was found between bovine and rabbit isolates. Finally, it was proven that feeding newborn calves with colostrum of their dams, previously vaccinated with an inactivated rotavirus vaccine, could prevent the neonatal diarrhea from occurring.

The use of a non-specific defence mechanism inducer in calves exposed to bovine herpesvirus-1 infection: preliminary trials.

The efficacy of an immunomodulator, the Baypamun (Bayer AG), was tested in calves which were subsequently exposed to bovine herpesvirus-1 (BHV-1) infection. Two groups of calves, of 8 animals each, were used for two trials. In one trial, 4 calves were treated with the immunomodulator and the remaining 4 were left as untreated controls. Two hours after the first injection of Baypamun, all calves, i.e. the treated and the untreated ones, were challenged with BHV-1. Comparing them to the untreated controls, the calves which were given the immunomodulator developed milder signs of the disease and shed a significantly lower concentration of virus. In the second experiment, 4 calves were given Baypamun and 4 calves were not, as above, but they were not inoculated with BHV-1; however, they were housed together with the calves of the former group (experimentally infected with BHV-1). The 8 calves all became infected but those that had been treated with Baypamun did not show any clinical signs of the disease, whereas the untreated calves underwent a clinical response which was considered to be typical of BHV-1 respiratory infection, as usually seen under natural conditions. In this case the shedding of virus by the calves treated with the immunomodulator also underwent a significant reduction.

Comparative study of two strains of Bovid herpesvirus-4.

Two strains of Bovid herpesvirus-4 (BHV-4), i.e. the prototype strain DN-599, obtained from a steer suffering of a respiratory disease, and the strain 85/BH 16TV, originated from a cow with vulvovaginitis, were compared in studies which included restriction endonuclease analysis, experimental infection and reciprocal cross protection tests. The restriction endonuclease analysis revealed that the resultant DNA patterns of the isolates were generally similar with only a difference in one fragment. The two strains were capable of causing respiratory tract infection in calves, even if they displayed a different level of virulence: the strain 85/BH 16TV being the most virulent while the strain DN-599 the least. The two viral strains were mutually protective in that the calves were generally found to be refractory to challenge inoculation with either the homologous or the heterologous virus. Finally, both viral strains failed to evoke the production of neutralizing antibody in the experimental calves.

Experimental infection of calves with strains of Bovid herpesvirus-4.

Fourteen calves were inoculated intranasally (i.n.) with the viral isolates as follows: 5 with 85/BH 16TV, 1 with 85/BH 17TV, 1 with 85/BH 18TV, 2 with 85/BH 231TN and 5 with 85/BH 232TN. Strain 85/BH 16TV was the only one which caused overt respiratory-like disease in all inoculated calves. Onset of the disease was observed after 7-8 days of incubation and was characterized by fever, depression, nasal discharge and coughing. Virus was isolated from the nasal swabbings of calves obtained from post-infection day (PID) 2-10. The other viral strains did not cause any sign of disease although virus was isolated regularly from the nasal swabbings of the inoculated calves. Virus was recovered from central nervous system tissues of calves that were infected with 85/BH 16TV or 85/BH 232TN strains and were killed on PID 4 or 8. Virus was also isolated from other tissues, such as lymph node, nasal mucosa (PID 8), or lung (PID 4). It was speculated that the nervous system could be one of the target areas of the virus of the naturally occurring infection by BHV-4. This might indicate a possible role of the nervous system (site of latency?) in the pathogenesis of BHV-4 as is the case in certain herpesviral infections of man and the lower animals.

A non-specific defence inducer in preventing clinical signs of infectious bovine rhinotracheitis in calves.

One calf was infected with bovine herpesvirus-1 (BHV-1) and mixed with five other calves, of which one had been vaccinated with a BHV-1 modified live vaccine one month earlier. The other four calves were vaccinated at the time the experimentally infected calf developed the first signs of the disease (fever, depression, nasal discharge), i.e. on post infection day (PID) 2. In addition to the vaccine, two of the four PID 2 vaccinated calves also received a non-specific defence (NSD) inducer (Baypamun, Bayer AG) at the same time as the vaccine. The calf that was vaccinated 1 month before the start of the experiment, as expected, did not show any signs of the disease. Of the remaining four, the two vaccine-only calves experienced a classical form of infectious bovine rhinotracheitis. However, the two calves that had also received the NSD inducer remained generally healthy during the entire observation period of 30 days. It was speculated that the use of a NSD inducer once an outbreak of a respiratory disease has started on a farm could be of significant help in an emergency in reducing the clinical manifestations in those animals that may subsequently be infected.

Experimental infection and cross protection tests in calves with cytopathic strains of bovine rotavirus.

Four cytopathic strains (81/32F, 81/36F, 81/40F, 82/80F) of bovine rotavirus were shown to be pathogenic for conventionally reared newborn calves. Calves were infected orally, using 3 calves for each isolate. All became febrile, were depressed and diarrhoeic. Two calves, one of which in the group of those infected with 81/36F isolate, and the other infected with strain 81/40F, were killed when moribund. A 3rd calf from the 81/36F infected group, died. At necropsy localized lesions of the small intestines, which are considered to be typical of rotavirus infection, were found. Virus was consistently isolated from the fecal samples of the inoculated calves up to 13 days post-inoculation. It was speculated that some differences existed in the virulence of the bovine rotaviruses tested. The cross protection tests revealed that 1 strain (81/36F) might be antigenically more complex than the others.

Reactivation of Bovid herpesvirus 1 and 2 and parainfluenza-3 virus in calves latently infected.

Two experiments were carried out to determine whether Bovid herpesvirus (BHV) 2 is able to induce a recurrent infection in experimentally infected calves. In the first experiment the stress induced by dexamethasone (DMS) treatment failed to reactivate the clinical condition or to induce shedding of BHV2. However, treatment with DMS reactivated a latent BHV1 infection in all calves previously inoculated with BHV2 and also in two noninoculated controls. Probably, because of the interference by BHV1 the study failed to resolve the question as to whether BHV2 could induce a recurrent infection. Consequently, a second experiment was performed using calves devoid of antibody to BHV1 and, therefore, probably, free of virus. By this study it was demonstrated that BHV2 can remain as a latent infection in cattle, which, when immunosuppressed as with DMS, can be reactivated. A finding of considerable interest in this experiment was that in 1 calf a concurrent piroplasma infection was also, unexpectedly, discovered. Recrudescence of latent BHV1 infection was induced by DMS treatment of calves possessing antibody to the virus. The infection once reactivated, was readily transmitted by contact to three other calves devoid of antibody to BHV1. In the same experiment Parainfluenza-3 (PI-3) virus was unexpectedly isolated from all calves. It was speculated that all calves were latently infected with PI-3 virus with concurrent infection by HBV1 acting as a stress inducing PI-3 reactivation. These studies seem to indicate that mixed infections could have an important role in the mechanism involved in the establishment of latent infections and viral reactivation.