Examining Immunotherapy Response Using Multiple Radiotracers

Molecular Imaging and Biology - Cancer immunotherapy has shown huge potential in the fight against cancer, but only a small proportion of patients respond successfully to treatment. Non-invasive...     

Voice Disorders in Occupations with Vocal Load in Slovenia

Aim

The aim of this paper is to compare the prevalence of voice disorders and the risk factors for them in different occupations with a vocal load in Slovenia.

Methods

A meta-analysis of six different Slovenian studies involving teachers, physicians, salespeople, catholic priests, nurses and speech-and-language therapists (SLTs) was performed. In all six studies, similar questions about the prevalence of voice disorders and the causes for them were included.

Results

The comparison of the six studies showed that more than 82% of the 2347 included subjects had voice problems at some time during their career. The teachers were the most affected by voice problems. The prevalent cause of voice problems was the vocal load in teachers and salespeople and respiratory-tract infections in all the other occupational groups. When the occupational groups were compared, it was stated that the teachers had more voice problems and showed less care for their voices than the priests. The physicians had more voice problems and showed better consideration of vocal hygiene rules than the SLTs. The majority of all the included subjects did not receive instructions about voice care during education.

Conclusions

In order to decrease the prevalence of voice disorders in vocal professionals, a screening program is recommended before the beginning of their studies. Regular courses on voice care and proper vocal technique should be obligatory for all professional voice users during their career. The inclusion of dysphonia in the list of occupational diseases should be considered in Slovenia as it is in some European countries.     

Magnetic resonance imaging findings of internal derangement in temporomandibular joints without a clinical diagnosis of temporomandibular disorder

The purpose of this study was to assess the prevalences of magnetic resonance (MR) imaging findings of internal derangement (ID) in temporomandibular joints (TMJs) without a specific clinical diagnosis of temporomandibular disorder (TMD), and to investigate whether in this TMJ group the variable of pain may be linked to MR imaging findings of ID. The study comprised 109 patients, who were assigned a clinical uni- or bilateral TMJ-related diagnosis of 'absence of TMD'. Bilateral sagittal and coronal MR images were obtained subsequently to establish the prevalence of TMJ ID. An MR imaging diagnosis of ID was found in 99 (55.9%) of the 177 TMJs investigated. About 30.3% of the closed mouth-related TMJ positions characterized by disc displacement presented with anterior disc displacement, while 27.3% had anterolateral and 25.3% anteromedial disc displacement. Analysis of the data revealed the presence of TMJ pain to be associated with significantly more MR imaging diagnoses of disc displacement without reduction than disc displacement with reduction (P < 0.05), while there was no significant difference in the prevalences of ID and those of absence of ID (P > 0.05). Using chi-square analysis, no significant relationship was found between the presence of TMJ pain and the MR imaging diagnosis of TMJ ID (P=0.93). Use of the kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of ID (kappa=0.01). The results suggest TMJs with a clinical diagnosis of 'absence of TMD' to be associated with a high rate of IDs, while in these instances the clinical variable of TMJ pain may have no effect on prevalences of MR imaging diagnoses TMJ ID. The data confirm the aspect of clinical diagnostic criteria as an unreliable instrument in predicting MR imaging diagnoses of TMJ ID.     

Adherent cell inhibition of human leukemic in vitro agar clonal growth by short-term cell-to-cell contact

The effects of peripheral blood adherent cells from normal donors on human myeloid leukemic cluster growth in agar were studied. A prior co- incubation of nonadherent leukemic cells with adherent cell monolayers from 9 out of 10 donors in liquid cultures over a 4-hr period was sufficient to reduce subsequent leukemic growth in semisolid agar cultures. Inhibition was seen with adherent to leukemic cell ratios of as low as 0.5:1. Conversely, identical numbers of adherent cells in agar cultures but separated from the leukemic cells enhanced growth more than the cultures containing human placental conditioned media alone. Because leukemic cell exposure to adherent cells was brief, a cytotoxic mechanism appeared likely; however, this could not be detected by 51Cr release. Human peripheral blood adherent cells not activated by any in vitro mechanism suppress clonal growth of human myeloid leukemic cells by a mechanism requiring cell to cell contact. Examination of the inhibition of clonal growth appears to be more sensitive than 51Cr release as an indicator of adherent cell effects on myeloid leukemia.     

Production of interleukin-1 by bone marrow myeloma cells

Plasma cells isolated from bone marrow (BM) aspirates of 12 patients with multiple myeloma (MM) and nine patients with monoclonal gammopathy of undetermined significance (MGUS) were analyzed for production of cytokines with bone-resorbing activity, such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and lymphotoxin (LT). Culture supernatants of plasma cells from MM, but not from MGUS or normal donor, invariably contained high amounts of IL-1-beta and lower amounts of IL-1-alpha. With a single exception, TNF/LT biologic activity was not detected in the same supernatants. IL-6 was present in two of five supernatants tested. Normal B lymphocytes released both IL-1 and TNF/LT activities for four days after activation in vitro; however, production of these cytokines ceased at the final stage of plasma cell. Unexpectedly, the mRNA extracted from MM plasma cell hybridized with TNF- and LT- specific, as well as IL-1-specific probes, although the culture supernatants did not contain detectable TNF/LT biologic activity. When tested in the fetal rat long bone assay, MM plasma cell supernatants displayed a strong osteoclast-activating factor (OAF) activity, which was greatly reduced but not completely abolished by neutralizing anti- IL-1 antibodies. Anti-TNF or anti-LT antibodies were ineffective in the same test. We conclude that the IL-1 released in vivo by malignant plasma cells has a major role in pathogenesis of lytic bone lesions of human MM.     

Factor IX and prothrombin in amniotic fluid and fetal plasma: constraints on prenatal diagnosis of hemophilia B and evidence of proteolysis

Potential limitations of prenatal diagnosis of hemophilia B, as compared to hemophilia A, include (1) occurrence of far more frequent defects with abnormal circulating antigen, (2) lower levels of factor IX in fetal plasma at 16 to 20 weeks gestation, and (3) the presence of factor IX antigen in amniotic fluid. In addition, proteolysis could occur, especially with amniotic fluid contamination of fetal plasma. A sensitive polyclonal immunoradiometric assay for factor IX antigen was used to characterize the range of levels in amniotic fluids and fetal plasma samples. To assess for altered forms, factor IX species were compared to those of a homologous clotting factor, prothrombin. Fourteen postmortem abortus blood samples from fetuses of 14 to 23 weeks gestation had factor IX antigen levels that averaged 5.1 U/dL and ranged from 1.7 to 15 U/dL. Amniotic fluid factor IX antigen averaged 2.9 U/dL, with a range from 1.4 to 8.5 U/dL in 19 separate amniocentesis samples. Thus, in a male fetus at risk of hemophilia B and with a low circulating level of gene product, mixture of fetal plasma with amniotic fluid could severely limit prenatal diagnosis, assuming that the amniotic fluid factor IX is of maternal origin. Despite rapid processing of amniotic fluid samples, the prothrombin was extensively cleaved, suggesting that it had been activated in vivo. On gel electrophoresis of amniotic fluid samples, however, factor IX was only minimally cleaved. In the postmortem fetal blood specimens, prothrombin was partially cleaved. On crossed-immunoelectrophoresis, fetal plasma prothrombin showed decreased migration in calcium, compared to EDTA, indicative of mature gamma-glutamyl carboxylation. The latter presumably resulted from fetal hepatic synthesis.     

Role of cyclic nucleotides in rapid platelet adhesion to collagen

Adhesion of human platelets to type I collagen under arterial flow conditions is extremely fast, being mediated primarily by the alpha 2 beta 1 integrin (glycoprotein Ia/IIa). We have investigated the involvement of cyclic nucleotides in platelet adhesion to soluble native collagen immobilized on Sepharose beads using a new microadhesion assay under arterial flow conditions. To prevent platelet stimulation by thromboxanes and adenosine diphosphate (ADP), experiments were performed with aspirin-treated platelets in the presence of ADP-removing enzyme systems such as creatine phosphate/creatine phosphokinase or apyrase. Rapid reciprocal changes in platelet adenosine 3'5'-cyclic monophosphate (cAMP) and guanosine 3'5'-cyclic monophosphate (cGMP) occurred during adhesion. cAMP levels in adherent platelets were 2.4-fold lower than in effluent platelets or in static controls, whereas cGMP levels were increased 2.4-fold. These results suggest that contact between platelets and collagen stimulates guanylate cyclase and inhibits adenylate cyclase. This occurs in the absence of the platelet release reaction. We also studied short-term effects of agents that regulate cyclic nucleotide synthesis, prostaglandin E1 (PGE1) and sodium nitroprusside (SNP). After only 3.8 seconds at 10 to 30 dyne/cm2, PGE1 (10 mumol/L) increased cAMP 16.4- fold, whereas SNP (50 mumol/L) increased cGMP ninefold and caused a 3.2- fold increase in cAMP. Both PGE1 and SNP rapidly (< 5 seconds) inhibited platelet adhesion in a dose-dependent manner that was correlated with the increase in cyclic nucleotides. Our data suggest that cAMP and cGMP play a regulatory role in the initial phases of platelet adhesion to collagen mediated by the alpha 2 beta 1 integrin receptor.     

Circulating monoclonal B cells expressing P glycoprotein may be a reservoir of multidrug-resistant disease in multiple myeloma

Multiple myeloma is basically an incurable cancer. Most patients respond initially to chemotherapy with reduction in bone marrow (BM) plasma cells and monoclonal Ig levels, but the disease nearly always recurs and becomes refractory to therapy. The objective of this study was to characterize the expression of the multidrug transport pump, P- glycoprotein 170 (P-gp), in myeloma. The great majority of B cells from peripheral blood mononuclear cells (PBMCs) in myeloma express P-gp, detected by the monoclonal antibody MRK-16. P-gp+ blood B cells exhibit extensive DNA hyperdiploidy, suggesting replicative abnormality characteristic of malignant growth. We speculate these represent a stem cell population in myeloma. The proportion of B cells expressing P-gp was comparable among untreated myeloma patients and those treated with chemotherapy, biologic response modifiers, or off treatment. Among BM cells, P-gp was absent or low in untreated myeloma patients but was expressed at high levels on BM cells from patients previously treated with chemotherapy. For untreated patients the majority of B/plasma cells expressing P-gp are located in PBMCs, not the BM cells. Flow cytometric analysis of rhodamine 123 dye efflux indicated a functional P-gp that was efficiently blocked by verapamil or cyclosporin A (CsA). Both the CD11bhi CD19+ B cells and the T cells in myeloma PBMCs had active CsA-inhibited dye efflux, but monocytes lacked the ability to efflux dye. Nearly all CD38hi plasma cells from myeloma BM cells retained dye, indicating their lack of a functional transport pump. Thus, PBMC B cells may be the predominant set of drug-resistant tumor cells. Myeloma PBMC B cells were cultured with Adriamycin with or without CsA and drug toxicity evaluated by the induction of apoptosis, using flow cytometry to quantitate DNA disruption. No apoptosis was detectable at 0.01 microgram/mL adriamycin, the in vivo steady-state level, with or without CsA. With 0.1 microgram adriamycin, no apoptosis was detectable in the absence of CsA, but with CsA, 66% of B cells initiated DNA disruption, whereas most T cells were spared. This work suggests that currently used drug dosages are too low to effect P-gp+ B- cell death, even in the presence of CsA. We suggest that blood B cells comprise a highly drug-resistant subset of the myeloma B lineage that escapes conventional chemotherapy and may underlie the almost uniform fatal relapse in myeloma patients.