Barriers and strategies for oral medication adherence among children and adolescents with Type 2 diabetes

AIMS

Examine barriers for taking glucose-lowering oral medications, associated baseline characteristics, strategies used, and the adherence impact in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study.

METHODS

We studied youth prescribed oral diabetes medications over two years (N = 611, 583, and 525 at 6, 12, and 24 months). Clinicians documented barriers (e.g. forgetting, routines, other concerns) in the subsample that reported missed doses (N = 423 [69.2%], 422 [72.4%], and 414 [78.9%] at 6, 12, and 24 months, respectively). Adherence strategies were also assessed (e.g. family, schedule, reminder device) using standard questions. Logistic regression was used to analyze associations with medication adherence.

RESULTS

Those missing doses were not different from the total sample (61.5% female, 13.9 ± 2.0 years, >80% racial/ethnic minorities). No baseline demographic or clinical predictors of barriers to medication adherence were identified. Among those for whom barriers were assessed, "forgetting" with no reason named (39.3%) and disruptions to mealtime, sleep, and schedule (21.9%) accounted for the largest proportion of responses. Family support was the primary adherence strategy identified by most youth (≥50%), followed by pairing the medication regimen with daily routines (>40%); the latter strategy was associated with significantly higher adherence rates (p = 0.009).

CONCLUSIONS

Family supported medication adherence was common in this mid-adolescent cohort, but self-management strategies were also in evidence. Findings are similar to those reported among youth with other serious chronic diseases. Prospective studies of multi-component family support and self-management interventions for improving medication adherence are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00081328.

Englerin A Agonizes the TRPC4/C5 Cation Channels to Inhibit Tumor Cell Line Proliferation

Englerin A is a structurally unique natural product reported to selectively inhibit growth of renal cell carcinoma cell lines. A large scale phenotypic cell profiling experiment (CLiP) of englerin A on ¬over 500 well characterized cancer cell lines showed that englerin A inhibits growth of a subset of tumor cell lines from many lineages, not just renal cell carcinomas. Expression of the TRPC4 cation channel was the cell line feature that best correlated with sensitivity to englerin A, suggesting the hypothesis that TRPC4 is the efficacy target for englerin A. Genetic experiments demonstrate that TRPC4 expression is both necessary and sufficient for englerin A induced growth inhibition. Englerin A induces calcium influx and membrane depolarization in cells expressing high levels of TRPC4 or its close ortholog TRPC5. Electrophysiology experiments confirmed that englerin A is a TRPC4 agonist. Both the englerin A induced current and the englerin A induced growth inhibition can be blocked by the TRPC4/C5 inhibitor ML204. These experiments confirm that activation of TRPC4/C5 channels inhibits tumor cell line proliferation and confirms the TRPC4 target hypothesis generated by the cell line profiling. In selectivity assays englerin A weakly inhibits TRPA1, TRPV3/V4, and TRPM8 which suggests that englerin A may bind a common feature of TRP ion channels. In vivo experiments show that englerin A is lethal in rodents near doses needed to activate the TRPC4 channel. This toxicity suggests that englerin A itself is probably unsuitable for further drug development. However, since englerin A can be synthesized in the laboratory, it may be a useful chemical starting point to identify novel modulators of other TRP family channels.

Outcome of renal transplantation in adult patients with augmented bladders

OBJECTIVE

We studied the long-term renal graft functions, survivals, and complications among patients with augmented bladders.

PATIENTS AND METHODS

Between 1976 and 2008, we performed 6/2600 renal transplantations in patients with augmented bladders. The mean patient age was 52 years. The cause of end-stage renal disease was chronic interstitial kidney disease in all patients, being secondary to lower urinary tract dysfunction. The etiology of bladder dysfunction was tuberculosis in 4 cases, bladder exstrophy in 1, and myelomeningocele in 1. Enterocystoplasty had been performed at a mean of 19 years prior to transplantation. The ureter was implanted into the native ureter in 5 cases and the bowel segment in 1 case.

RESULTS

With a mean follow-up of 56 months (range, 20-100 months), the overall graft survival was 50%. Three grafts were lost due to venous thrombosis (n = 1), and chronic allograft nephropathy (n = 2) at 37 and 100 months posttransplantation. No patient died during follow-up. Mean serum creatinine was 1.44 mg/dL with Modification of Diet in Renal Disease (MDRD) clearance of 76 mL/min/1.73 m(2). One fistula that caused obstructive uropathy and 2 cases of migration of a double J catheter were among the surgical complications. These patients showed a mean of 7 episodes of uncomplicated urinary infections. Only 1 patient was rehospitalized due to a complicated urinary tract infection.

CONCLUSIONS

Patients with enterocystoplasty and renal transplantation show a greater risk of urinary tract infections, albeit mostly uncomplicated. Despite this, the long-term results are acceptable.

[Anatomy, physiology and clinical relevance of the connecting tubule]

The cortical distal nephron is the site of fine regulation of salt and water excretion by peptide and mineralocorticoid hormones and the site for specific actions of diuretics. Some data suggest that sodium reabsorption and potassium secretion in the distal convoluted tubule and the connecting tubule (CNT) are sufficient to maintain the sodium and potassium balance, with little or no contribution of the collecting duct. The homeostatic role of the sodium and potassium transport systems in the collecting duct can be questioned, especially in conditions where dietary sodium intake is high and potassium intake is low compared with the physiological needs of the organism. The functional expression of epithelial sodium channels (ENaC) in the CNT is sufficient for furosemide-stimulated urinary acidification and identifies the CNT as a major segment in electrogenic urinary acidification. In the outer renal cortex, the CNT returns to the glomerular hilus and contacts the renal afferent arterioles (Af-Art). This morphology is compatible with a cross-talk between the CNT and Af-Art. This novel regulatory mechanism of the renal microcirculation may participate in the vasodilatation observed during high salt intake, perhaps by antagonizing tubuloglomerular feedback. In conclusion, the cortical distal nephron appears to be a complex site for several physiological mechanisms; it is mainly involved in salt and fluid homeostasis and in acid-base balance maintenance. Furthermore, the CNT segment appears to promote a CNT-Af-Art feedback loop.

[Pendrin: physiology, molecular biology and clinical importance]

Pendrin, first identified in 1997, belongs to a superfamily of anion transporters localized in the thyroid gland, inner ear and kidney. Immunohistochemical studies have shown that pendrin is expressed at the apical surface of follicular thyroid cells, where it acts as a Cl-/I- exchanger regulating the chloride transport from the cytoplasm to the colloid space. In the inner ear, pendrin has been found in the stria vascularis of the cochlea and in the endolymphatic duct and sac, where it functions as a Cl- /HCO-3 exchanger. Finally, pendrin is expressed in the kidney, where it is localized in the apical membrane of type-B intercalated cells and non-A, non-B intercalated cells of the cortical collecting ducts and connecting tubules, where it again acts as a Cl /HCO-3 exchanger regulating the acid-base status and chloride homeostasis. Pendrin is encoded by the PDS gene, which is mapped on chromosome 7 (7q22-31.1). Mutations of PDS lead to the Pendred syndrome, a genetic disorder transmitted as an autosomal recessive trait characterized by sensorineural deafness and goiter. It is reasonable to hypothesize that patients affected by Pendred's syndrome may have disturbances of renal function, especially in the regulation of electrolytes and acid-base balance in stress conditions.

Congenital amegakaryocytic thrombocytopenia--report of a new c-mpl gene missense mutation

A 44-month old girl with congenital amegakaryocytic thrombocytopenia, already with pancytopenia, underwent an unrelated allogeneic cord blood transplantation with recovery of normal blood cell counts. The patient was a compound heterozygote for two c-mpl missense mutations inherited from both parents, one of them, a G578A exon 4 mutation leading to a cysteine to tyrosine replacement of codon 193, previously unreported.

Inhibition of water intake by the central administration of IL-1beta in rats: role of the central opioid system

In the present study we investigated, the effect of third ventricle injections of IL-1beta on water intake, in rats, induced by three different physiological stimuli: dehydration induced by water deprivation, hypernatremia associated with hyperosmolarity induced by intragastric salt load, and hypovolemia produced by subcutaneous polytethyleneglycol administration. Central administration of IL-1beta at the doses of 4 and 8 ng reduced water intake in all three conditions studied. Third ventricle injections of IL-1beta (8 ng) were unable to diminish water intake in the groups of rats pretreated with central injections of the non-selective opioid antagonist naloxone (10 microg) in the three different conditions studied. Furthermore, the central administration of IL-1beta was neither able to modify the intake of a 0.1% saccharin solution when the animals were submitted to a "dessert test" nor to induce any significant locomotor deficit in the open-field test. These results suggest that the central activation of interleukin-1 receptors by IL-1beta is able to impair the thirst-inducing mechanisms triggered by the physiological stimuli represented by dehydration, hyperosmolarity and hypovolemia. These results lead us to conclude that the antidipsogenic effects observed following central administration of IL-1beta require the functional integrity of the brain opiatergic system.

Role of the central opioid system in the inhibition of water and salt intake induced by central administration of IL-1β in rats

In the present study we investigated, the effect of third ventricle injections of IL-1beta on water and salt intake in fluid-deprived and sodium-depleted rats. Central administration of IL-1beta significantly reduced water and salt intake in fluid-deprived animals and decreased salt intake in sodium-depleted rats. The antidipsogenic and antinatriorexic effects elicited by the central administration of IL-1beta were suppressed by pretreatment with central injections of the non-selective opioid antagonist naloxone (10 mug) in the two different experimental protocols used here (water deprivation and sodium depletion). In addition, central administration of IL-1beta failed to modify the intake of a 0.1% saccharin solution when the animals were submitted to a "dessert test" or to induce any significant locomotor deficit in the open-field test. The present results suggest that the activation of the central interleukinergic component by IL-1beta impairs the increase in water and salt intake induced by water deprivation and the enhancement in sodium appetite that follows sodium depletion. The data also support the conclusion that the antidipsogenic and antinatriorexic effects resulting from the activation of the central interleukinergic component rely on an opioid-dependent, naloxone-blockable system.

Ancestim (recombinant human stem cell factor, SCF) in association with filgrastim does not enhance chemotherapy and/or growth factor-induced peripheral blood progenitor cell (PBPC) mobilization in patients with a prior insufficient PBPC collection

Up to a third of autologous transplantation candidates fail to mobilize hematopoietic progenitors into the peripheral blood with chemotherapy and/or growth factor treatment, thus requiring innovative mobilization strategies. In total, 20 cancer patients unable to provide adequate PBPC products after a previous mobilization attempt were treated with ancestim (20 microg/kg/day s.c.) and filgrastim (10 microg/kg/day s.c.). In 16 patients, the pre-study mobilization was with filgrastim alone. Eight patients underwent single large volume leukapheresis (LVL) and 12 multiple standard volume leukaphereses (SVL) in both mobilizations. Pairwise comparison of peripheral blood CD34(+) cell concentrations on the day of first leukapheresis failed to document synergism - median CD34(+)/microl of 3.2 (<0.1 to 15.4) and 4.5 (1-28.56) for the pre-study and on-study mobilizations (P = 0.79, sign test), and 4.2 (<0.1-15.4) and 5 (1-28.56), respectively, for the 16 patients previously mobilized with filgrastim alone (P = 1, sign test). The number of CD34(+) cells/kg collected per unit of blood volume (BV) processed was similar in both mobilizations - median 0.1 x 10(6)/kg/BV and 0.09 x 10(6)/kg/BV, respectively (P = 1, sign test). In this phase II study, the combination of ancestim and filgrastim did not allow adequate PBPC mobilization and collection in patients with a previous suboptimal PBPC collection.

Advantages and limits of robot-assisted laparoscopic surgery: preliminary experience

BACKGROUND

In the last few years, robotics has been applied in clinical practice for a variety of laparoscopic procedures. This study reports our preliminary experience using robotics in the field of general surgery to evaluate the advantages and limitations of robot-assisted laparoscopy.

METHODS

Thirty-two consecutive patients were scheduled to undergo robot-assisted laparoscopic surgery in our units from March 2002 to July 2003. The indications were cholecystectomy, 20 patients; right adrenalectomy, two points; bilateral varicocelectomy, two points; Heller's cardiomyotomy, two points; Nissen's fundoplication, two points; total splenectomy, one point; right colectomy, one point; left colectomy, 1 point; and bilateral inguinal hernia repair, one point. In all cases, we used the da Vinci surgical system, with the surgeon at the robotic work station and an assistant by the operating table.

RESULTS

Twenty-nine of 32 procedures (90.6%) were completed robotically, whereas three were converted to laparoscopic surgery. Conversion to laparoscopy was due in two patients to minor bleeding that could not be managed robotically and to robot malfunction in the third patient. There were no deaths. Median hospital stay was 2.2 days (range, 2-8).

CONCLUSIONS

The main advantages of robot-assisted laparoscopic surgery are the availability of three-dimensional vision and easier instrument manipulation than can be obtain with standard laparoscopy. The learning curve to master the robot was >or= 10 robotic procedures. The main limitations are the large diameter of the instruments (8 mm) and the limited number of robotic arms (maximum, three). We consider these technical shortcomings to be the cause for our conversions, because it is difficult to manage bleeding episodes with only two operating instruments. The benefit to the patient must be evaluated carefully and proven before this technology can become widely accepted in general surgery.

Regression of infancy hemangiomas with recombinant IFN-alpha 2b

Interferon-alpha (IFN-alpha) has antitumor and antiangiogenic effects. The purpose of this work was to evaluate its efficacy and safety in the treatment of infancy hemangioma and to monitor the appearance of anti-IFN antibodies in these patients. Thirty-nine children (29 girls) aged 1.5-158 months, with 19 younger than 1 year and 9 older than 5, were treated with 3 x 10(6) IU/m(2) IFN-alpha 2b, subcutaneously (s.c.) daily. Inclusion criteria were life-threatening or life-limiting hemangioma and parents' informed consent. Regression was considered if tumor size diminished by 50% or more. Of the 38 patients who completed 6 months of treatment, 27 (71.1%) had regression and 11 (28.9%) had stable disease. No patient experienced progression. Regression was more frequent (100%) among patients between 1 and 5 years old, but it was particularly important (68%) among those under 1 year old, when spontaneous regression is rare. The main side effects were the IFN-related flulike syndrome (79%), increase in serum alanine aminotransferase (ALT) (28%), anorexia (19%), and mild inflammation at the injection site (19%). There was no effect on psychomotor or physical development. On the contrary, 1 patient with neurologic symptoms improved remarkably, including seizure disappearance. Eight patients developed anti-IFN-alpha 2 neutralizing antibodies, and 7 of them responded to IFN treatment. IFN-alpha 2b is a safe and efficacious treatment of infancy hemangioma. Further work should look for other treatment schedules and ways of administration and carefully monitor anti-IFN neutralizing antibodies, which does not seem to interfere with response.

HGF/SF and its receptor c-MET play a minor role in the dissemination of human B-lymphoma cells in SCID mice

The MET protooncogene, c-MET, encodes a cell surface tyrosine kinase receptor. The ligand for c-MET is hepatocyte growth factor (HGF), also known as scatter factor (SF), which is known to affect proliferation and motility of primarily epithelial cells. Recently, HGF/SF was also shown to affect haemopoiesis. Studies with epithelial and transfected NIH3T3 cells indicated that the HGF/SF-c-MET interaction promotes invasion in vitro and in vivo. We previously demonstrated that HGF/SF induces adhesion of c-MET-positive B-lymphoma cells to extracellular matrix molecules, and promoted migration and invasion in in vitro assays. Here, the effect of HGF/SF on tumorigenicity of c-MET-positive and c-MET-negative human B-lymphoma cell lines was studied in C.B-17 scid/scid (severe combined immune deficient) mice. Intravenously (i.v.) injected c-MET-positive (BJAB) as well as c-MET-negative (Daudi and Ramos cells) B-lymphoma cells formed tumours in SCID mice. The B-lymphoma cells invaded different organs, such as liver, kidney, lymph nodes, lung, gonads and the central nervous system. We assessed the effect of human HGF/SF on the dissemination of the B-lymphoma cells and found that administration of 5 microg HGF/SF to mice, injected (i.v.) with c-MET-positive lymphoma cells, significantly (P = 0.018) increased the number of metastases in lung, liver and lymph nodes. In addition, HGF/SF did not significantly influence dissemination of c-MET-negative lymphoma cells (P = 0.350 with Daudi cells and P= 0.353 with Ramos cells). Thus the effect of administration of HGF/SF on invasion of lymphoma cells is not an indirect one, e.g. via an effect on endothelial cells. Finally, we investigated the effect of HGF/SF on dissemination of c-MET-transduced Ramos cells. In response to HGF/SF, c-MET-transduced Ramos cells showed an increased migration through Matrigel in Boyden chambers compared to wild-type and control-transduced Ramos cells. The dissemination pattern of c-MET-transduced cells did not differ from control cells in in vivo experiments using SCID mice. Also no effect of HGF/SF administration could be documented, in contrast to the in vitro experiments. From our experiments can be concluded that the HGF/SF-c-MET interaction only plays a minor role in the dissemination of human B-lymphoma cells.

[The use of peripheral blood progenitor cells as an autologous hematopoietic support in high-dose chemotherapy. I. The rationale and results]

We review the rationale for PBPC transplantation and the results reported in the literature. In order to prolong complete remissions and increase cure rates, high-dose chemotherapy is frequently used in the treatment of selected neoplasias. Hematological toxicity can be overcome by the infusion of autologous hemopoietic progenitors. Recently, peripheral blood is being used as the preferred source for hemopoietic progenitors, since it allows faster hematopoietic recoveries when compared to progenitors harvested from bone marrow. An adequate graft is defined by its content in clonogenic progenitors (mainly CFU-GM) and CD34 positive cells; these two parameters need to be accurately determined by specific laboratory methods. PBPC grafts are harvested using cell separators during leukaphereses; to increase efficiency, hemopoietic progenitors are first mobilized into the circulation with growth factors and or chemotherapy. PBSC transplantation may have procedure-associated toxicity related to the mobilization, harvest or reinfusion of the graft.

[The use of peripheral blood progenitor cells as an autologous hematopoietic support in high-dose chemotherapy. II. The experience of the Hematological Intensive Care Unit of the IPOFG. Franciso Gentil Portuguese Institute of Oncology]

We report the results of PBPC collection by large-volume leukaphereses and the hematologic recovery after high-dose chemotherapy supported by autologous PBPC reinfusion in a series of cancer patients treated at the Hematological Intensive Care Unit (UCHI) (Portuguese Institute of Oncology, Lisbon). Large volume leukaphereses were used to increase the efficacy of the PBPC collection. This modification of the standard apheresis technique allowed the harvesting, in only one session, of enough progenitors to proceed to transplantation in nearly 2/3 of patients and without significant toxicity. From December 1993 until September 1997, 95 autologous PBSC transplants were performed at the UCHI; 45% were performed in solid tumor patients and 55% in patients with hematologic malignancies. Hematologic recovery was similar to that published in the literature and related to the number of CD34+ cells infused. Patients supported with bone marrow in addition to PBPC showed delayed hematopoietic recovery, probably because the bone marrow harvest was only performed when an insufficient number of PBPC had been collected (2 x 10(6) CD34+ cells/Kg). The speed of hematological recovery differed per diagnosis, being higher in multiple myeloma and solid tumor patients and lower in Hodgkin's disease patients.

Protein S-nitrosating agents

A series of peptidyl N-nitrosoanilines were designed, synthesized, and evaluated as inactivators of cysteine protease papain. These new compounds exhibited different inhibitory activities toward cysteine protease papain in a time- and concentration-dependent manner with second-order rate constants (ki/KI) ranging over two orders of magnitude from 0.604 M-1 sec-1 (1) to 100.36 M-1 sec-1 (7). Formation of the S-NO bond in papain is corroborated by evidence obtained from spectroscopic analyses. The fact that S-nitrosylated enzyme can regain its activity upon addition of thiol compounds such as glutathione makes this class of compounds suitable as templates for the development of potent reversible and covalent cysteine protease inhibitors.

Hepatocyte growth factor/scatter factor (HGF/SF) is produced by human bone marrow stromal cells and promotes proliferation, adhesion and survival of human hematopoietic progenitor cells (CD34+)

The fate of hematopoietic progenitor cells (HPCs) in the bone marrow (BM) microenvironment is determined by two different interactions: 1) they adhere (via integrins) to both extracellular matrix molecules and BM stromal cells; and 2) stromal cells produce cytokines that influence their survival, proliferation, differentiation, and mobilization. The ligands for the protein tyrosine kinase receptors c-KIT and FLT3/FLK2, stem cell factor (SCF), and FL are produced by BM stromal cells and are known to affect several facets of hematopoiesis. We studied another protein tyrosine kinase receptor, c-MET, and its ligand hepatocyte growth factor (HGF), also known as scatter factor (SF), which play a similar role in hematopoiesis. c-MET mRNA is expressed in immature human BM HPCs (CD34+CD33- or CD34+CD38-), but not in more mature HPCs (CD34+CD33+ or CD34+CD38+). The ligand HGF/SF is predominantly produced by BM stromal cells at both the mRNA and protein levels. We confirmed functionally that HGF/SF alone has no effect on proliferation of HPCs, but that when combined with granulocyte/macrophage colony-stimulating factor (GM-CSF) or interleukin-3 it acts as a synergistic proliferative factor, although not as potently as kit-ligand or FLT-3/FLK-2 ligand. Furthermore, HGF/SF promotes adhesion of HPCs to immobilized fibronectin. HGF/SF-induced adhesion to fibronectin is probably caused by activation of the integrins alpha4beta1 and alpha5beta1, insofar as we were able to block this interaction by using monoclonal blocking antibodies directed against these integrin subunits. Addition of the tyrosine-phosphorylation inhibitor genistein inhibited HGF/SF-induced adhesion, supporting the idea that HGF/SF-induced effects are the result of signaling via the receptor c-MET after ligand binding. The enhanced adhesion of HGF/SF to fibronectin proved to be beneficial for the maintenance of the colony-forming potential of HPCs. HGF/SF alone and especially in combination with fibronectin prolongs survival of GM colony-forming cells in liquid culture. Our data indicate that HGF/SF is a polyfunctional cytokine in the BM microenvironment. It is produced by human BM stromal cells and directly or indirectly promotes proliferation, adhesion, and survival of human HPCs.

Hepatocyte growth factor/scatter factor (HGF/SF) affects proliferation and migration of myeloid leukemic cells

Hepatocyte growth factor (HGF), also known as scatter factor (SF), is produced by mesenchymal cells, including bone marrow (BM) stromal cells, and has mitogenic and motogenic effects on a variety of cell types. Recently, a role has been assigned to HGF/SF and its receptor, c-MET, in both normal and malignant hemopoiesis. We investigated the function of HGF/SF on hemopoietic mononuclear cells (MNC) from patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) with circulating blasts. In contrast to results with normal MNC, HGF/SF alone stimulated the proliferation and colony formation of MNC from these patients. MNC from some (4/13) of the AML patients also produced HGF/SF (0.1-0.2 ng/ml/day), while we could not detect HGF/SF in cultures from normal MNC. Furthermore, it appeared that HGF/SF induced migration of leukemic cells in Boyden using KG1a cells as a model for leukemic blasts. The membranes dividing the two compartments of the Boyden chambers were coated with fibronectin. HGF/SF significantly promoted migration in 3/5 samples of MDS patients and in 5/7 samples of AML patients. Supernatant of human BM stromal cells, which is chemoattractive for normal human hemopoietic progenitor cells, also promoted migration of MNC from 4/5 MDS patients and 6/7 AML patients. Since HGF/SF is one of the growth factors produced by BM stromal cells, a neutralizing antibody directed against HGF/SF was added to the BM stroma supernatant, which reduced migration significantly in 2/3 MDS and in 3/6 AML responders to BM stroma supernatant. In conclusion, HGF/SF promotes proliferation and migration of hemopoietic cells from AML and MDS patients in vitro and may therefore contribute to the malignant potential of these cells.

HTLV Tax gene expression in patients with lymphoproliferative disorders

AIMS

To study the expression of the human T lymphotropic virus (HTLV) Tax gene in peripheral blood mononuclear cells.

METHODS

Blood was collected from 72 patients with lymphoproliferative disorders. Serum from all patients was assayed for antibodies directed against HTLV-I structural proteins by ELISA and western blotting. RNA was purified from fresh blood cells and amplified by reverse transcription polymerase chain reaction (RT-PCR). After Southern blotting, the PCR products were hybridised with a 32P end-labelled probe specific for the Tax gene.

RESULTS

All samples were seronegative. A specific band for the Tax gene was found in five samples. Each of the patients positive for Tax gene expression had a different type of lymphoproliferative disorder.

CONCLUSIONS

Infection by HTLV-I cannot be assessed solely by immunological assays, particularly when only disrupted virions are used. Sensitive molecular biology assays are essential for detecting viral gene expression in fresh blood cells.