The effect of poisoned and notional vaccinated buffers on possum (Trichosurus vulpecula) movements: minimising the risk of bovine tuberculosis spread from forest to farmland

Context. Vaccination of brushtail possums (Trichosurus vulpecula) has been proposed as a cost-effective alternative to lethal control for preventing potentially bovine tuberculosis (Tb)-infected possums from crossing forested buffer zones that abut farmland. Aim. Evaluation of these two management option requires an estimation of the buffer width required to reduce the risk of disease spread to an acceptable level. Methods. The movements of two groups of adult and subadult possums were monitored for up to 12 months in the Kaimanawa Range, North Island of New Zealand, using GPS technology. One group was in untreated forest immediately adjacent to a recently poisoned forest buffer, and the second group was 2 km further into untreated forest, which mimicked a vaccinated buffer with no reduction in possum abundance. Key results. Close to the poisoned buffer, where the initial population density was 0.49–1.45 ha–1, adult possum home ranges averaged 10.2 ha in the summer immediately after control and 9.5 ha in the following winter. Two kilometres into the untreated forest, where the density was >3 ha–1, the corresponding values were only 3.5 ha and 2.8 ha. Over the first 6 months of monitoring, a ~350-m wide poisoned buffer would have contained 95% of movements by adult possums, as well as movements by most individuals, but a ~150-m wide vaccinated buffer would have been as effective. Equivalent results for the subsequent 6-month period were ~450 m and ~200 m for poisoned and vaccinated buffers, respectively. Movements by possums were not biased in the direction of the population ‘vacuum’ created by the poisoning operation. When subadult possums were included in the analysis, buffer widths of ~500–600 m for both poisoning and vaccination would be required to contain 95% of new den site locations. Conclusions and implications. Detailed data on possum movements provide a means for agencies managing Tb to specify the width of a buffer, subject to an acceptable level of risk that it could be breached by a potentially infected possum. As well as depending on the width of a treated buffer, the final cost-effectiveness of vaccination compared with poisoning will depend on the relative cost of applying the two control techniques, and the frequency of application required either to prevent Tb from establishing (in the case of vaccination) or to suppress possum density (in the case of lethal control).

Durable responses with the antiangiogenic metronomic regimen RT-PEPC in elderly patients with recurrent mantle cell lymphoma (MCL)

8525

Background: Targeting tumor microenvironment and angiogenesis is a novel therapeutic strategy in lymphoma. Two putative anti-angiogenic regimens, RT (rituximab with thalidomide) and PEPC oral metronomic chemotherapy (prednisone, etoposide, procarbazine and cyclophosphamide) are clinically active. We report phase II safety, activity, and angiogenic profiling data with the novel combination RT-PEPC in elderly patients with recurrent MCL. Methods: RT-PEPC includes an induction phase (mo 1–3) of daily thalidomide (50 mg) and PEPC with weekly rituximab x 4. A maintenance phase (mo 4 until progression) continues with daily thalidomide (100 mg), PEPC dosing titrated to ANC > 1K/ul, and rituximab q 4 months. Endpoints included safety, efficacy, and FACT-G quality of life (QoL) assessment. Translational studies assessed the angiogenic phenotypes of tumor cells, and dynamic levels of circulating endothelial and hematopoietic progenitors in response to treatment. Results: Twenty-five pts (19 males) were enrolled, with 22 evaluable (3 never received rx). At study entry, median age (N=25) was 68 yrs (range 52–81), 24 (96%) had stage ≥ III, 16 (64%) had LDH > nl, and 18 (72%) IPI 3–5. The median number of prior therapies was two (range 1 to 7), and 15 pts (60%) progressed on bortezomib. At a median followup of 30 months, overall response rate was 73% (32% CR/CRu, 41% PR, N=22). Median PFS was 12 months, and median OS 22 months. Four CRs of 4+, 28+, 46+ and 48+ months are ongoing. Toxicities included gr 1–2 fatigue, rash and neuropathy as well as cytopenias (by design) including gr 1–2 thrombocytopenia (56%) and gr 3/4 neutropenia (56%). Two thrombotic events and 5 episodes of gr 3–4 infection were observed. QoL was maintained or improved on treatment. Correlative studies demonstrated pre-therapy autocrine angiogenic loop in tumor cells evidenced by expression of VEGFA and VEGFR1. Circulating levels of hematopoietic and endothelial progenitor cells decreased on rx in responders. Conclusions: RT-PEPC has significant and durable clinical activity in MCL, with manageable toxicity and maintained QoL. Novel low-intensity anti-angiogenic approaches warrant further evaluation in MCL and other NHL subtypes, potentially as initial therapy in elderly patients.

[Table: see text]

Operational impact of DDT reintroduction for malaria control on Anopheles arabiensis in Mozambique

ABSTRACT With the increase in indoor residual spraying in many internationally and nationally funded malaria control programs, and affirmation by World Health Organization (WHO) that DDT is appropriate for use in the absence of longer lasting insecticide formulations in some malaria endemic settings, DDT has been reintroduced as a major malaria control intervention in Africa. Indoor residual spraying with DDT was reintroduced into Mozambique for malaria control in 2005, and it is increasingly becoming the main insecticide used for malaria vector control in Mozambique. The selection of DDT in Mozambique is evidence-based, taking account of the susceptibility of Anopheles arabiensis (Patton) and Anopheles gambiae (Giles) s.s. to all the available insecticide choices, as well as relative costs of the insecticide and the logistical costs of spraying. Before this time in Mozambique, DDT was replaced by h-cyhalothrin in 1993. Resistance occurred quickly to this insecticide, and in 2000 the pyrethroid was phased out and the carbamate bendiocarb was introduced. Low-level resistance was detected by biochemical assay to bendiocarb in 1999 in both Anopheles funestus (Giles) and An. arabiensis, although this was not evident in WHO bioassays of the same population. In the 2000-2006 surveys the levels of bendiocarb resistance had been selected to a higher level in An. arabiensis, with resistance detectable by both biochemical and WHO bioassay. The insecticide resistance monitoring program includes assessment of field populations by standard WHO insecticide susceptibility assays and biochemical assays. Monitoring was established in 1999, and it was maintained as part of an operational monitoring and evaluation program thereafter.

Combined PET and low-dose, noncontrast CT scanning obviates the need for additional diagnostic contrast-enhanced CT scans in patients undergoing staging or restaging for lymphoma

BACKGROUND

Positron emission tomography (PET) is more accurate than computed tomography (CT) in staging and restaging of lymphoma, but both are considered necessary. Increasingly, PET is carried out with a low-dose CT scan. Many patients undergo both PET/CT and standard diagnostic CT. The clinical utility of performing both studies in patients with lymphoma was evaluated.

PATIENTS AND METHODS

Patients with lymphoma who underwent concurrent PET/CT and diagnostic CT (a scan pair) were identified, and findings detected in either scan but not both were documented. Discrepancies were considered significant if they were related to either lymphoma or another disease process which potentially required intervention.

RESULTS

Eighty-seven scan pairs were identified. PET/CT detected additional lesions over diagnostic CT in 30 patients, of which 11 demonstrated increased clinical stage. Lymphoma therapy changed based on PET/CT in two patients, and one occult rectal cancer was detected. In contrast, diagnostic CT detected five relevant findings, including two incidental findings (venous thrombosis) and three patients with splenic lesions, none of which could be confirmed as lymphoma. No patient had change of stage or lymphoma therapy based on diagnostic CT.

CONCLUSION

In our series, diagnostic CT did not add value to staging or restaging of lymphoma when carried out concurrently with PET/CT.

Oral combination chemotherapy for refractory/relapsed lymphoma with the PEP-C (C3) regimen (daily prednisone, etoposide, procarbazine, cyclophosphamide): Low-dose continuous metronomic multidrug therapy

8064

Background: Oral daily low dose chemotherapy (metronomic therapy) may maintain continuous sequential drug levels to impact endothelial cell viability (anti-angiogenesis) or to overcome drug resistance. Methods: We retrospectively reviewed data on 97 patients with refractory/relapsed Hodgkin's and non-Hodgkin's lymphoma treated with the PEP-C (C3) regimen, which consists of oral prednisone (20 mg in am), cyclophosphamide (50 mg at noon), etoposide (50 mg at dinner) and procarbazine (50 mg at h.s.with an oral anti- emetic). Medications were administered daily until the white blood cell count fell to less than 3000/dl, when treatment was held until recovery from the nadir. Treatment was then reinstituted on a daily, alternate day, or fractionated weekly basis (e.g. 5 of 7 days) based on patient tolerance. Doses given per day were constant. Results: All patients had been previously treated, with 80% having received 2 or more prior therapies and 57% with 3 or more previous regimens. Overall, 69 patients (71%) achieved a response. Responses by histology were: follicular (n=26) 92%, mantle cell (n=22) 82%, marginal zone (n=14) 71%, small lymphocytic (n=12) 67%, Hodgkin's lymphoma (n=9) 44%, diffuse large B cell (n=9) 33%, and T cell (n=5) 40%. Time on therapy of responding patients ranged from 3 weeks to 48 months (median 9 months, mean 11 months). Toxicity was predominantly myelosuppression, with hospitalization for infection occurring in 10 patients. Five patients developed H. zoster. Gastrointestinal effects prompting cessation of therapy occurred in 6 subjects, and 2 patients developed hematuria. Conclusions: Low dose, continuous (metronomic) combination chemotherapy with PEP-C is an easily administered, generally well- tolerated and effective treatment for relapsed/refractory lymphoma, particularly in indolent and mantle cell histologies.

No significant financial relationships to disclose.

CHOP-R + bortezomib as initial therapy for diffuse large B-cell lymphoma (DLBCL)

8031

Background: Bortezomib is a proteasome inhibitor with anti-tumor activity in B cell malignancies. These effects, which may relate to NF-kappaB associated pathways, could sensitize tumor cells to standard chemotherapy-based regimens and enhance efficacy. We report findings of a phase I/II trial of dose-escalated bortezomib + standard CHOP-rituximab in DLBCL patients (accrual of the MCL cohort of this study remains ongoing). Methods: Patients with previously untreated DLBCL (n=40) received CHOP-21 + rituximab (375 mg/m2 each cycle) plus bortezomib at 0.7 mg/m2 (Arm 0, n=4), 1.0 mg/m2 (Arm 1, n=8) or 1.3 mg/m2 (Arm 2, n=28 including phase I and all phase II) on days 1 and 4 of each cycle Results: Median age (n=40) was 58 years (range 21–86), thirty-five subjects (88%) had stage III/IV disease at study entry, and 29 (73%) had elevated serum lactate dehydrogenase (LDH). Patients generally had unfavorable baseline international prognostic index (IPI) scores of 2 in 16 subjects (40%) and 3–5 in 19 subjects (48%). Median follow-up is 21 months (range 9 - 35 months). Treatment was generally well tolerated. Peripheral neuropathy occurred in 22 subjects (55%), with 45% grade 1, 5% grade 2 and 5% grade 3. Grade 4 hematologic toxicity included thrombocytopenia (15%) and leukopenia (15%). Four subjects (3 over age 75 and all with high risk IPI) died prior to first response assessment. Intent to treat (ITT) overall response rate (n=40) is 90% with 68% CR/CRu. For the evaluable subset (n=36), ORR was 100% with CR/CRu 75%. Kaplan-Meier estimate (n=40) of 2-year progression-free survival is 72%. Of all 19 enrolled (ITT) patients in the high-intermediate or high-risk IPI groups, 14 (74%) were alive without progression at last assessment. Correlation of outcome with cell of origin type (activated B cell vs germinal center) is ongoing. Conclusions: Bortezomib can be administered with acceptable toxicity in conjunction with CHOP-R chemotherapy. Efficacy findings with this combination regimen in newly-diagnosed DLBCL are encouraging and warrant further study.

No significant financial relationships to disclose.

Low doses of humanized anti-CD20 antibody, IMMU-106 (hA20), in refractory or recurrent NHL: Phase I/II results

8032

Background: An open-label, multicenter study has shown that the humanized anti-CD20 antibody, IMMU-106 (hA20), which has framework regions of epratuzumab, has a good safety and efficacy profile in NHL pts when administered once-weekly × 4 at different doses. The trial is now focused on confirming the efficacy of lower doses (80–120 mg/m2/wk × 4). Methods: A total of 68 pts (35 male, 33 female; age 34–84) received hA20 at 750 (N=3), 375 (N=27), 200 (N=11), 120 (N=21), or 80 mg/m2 (N=6). They had follicular (FL, N=47) or other (N=21) B-cell NHL, were predominantly stage III/IV (N=47) at study entry, and had received 1–8 prior treatments (median, 2), including 1 (N=40) or more (N=21) rituximab regimens (without progression within 6 months). Results: Sixty- six pts completed all 4 infusions; 1 pt progressed during treatment and withdrew, while another pt with hives and chills after prior rituximab discontinued treatment after a similar episode at 1st infusion. hA20 was generally well tolerated, with shorter infusion times (typically 2 h initially and 1 h subsequently) at lower doses. Drug-related adverse events were transient, Grade 1–2, most occurring only at 1st infusion, and there was no evidence of HAHA in 54 pts now evaluated. Mean antibody serum levels increased with dose and infusions; serum clearance at 375 mg/m2 appears similar to rituximab. Currently, 48 pts with at least 12 wks follow-up were evaluated by Cheson criteria: 32 FL pts had 15 (47%) OR's with 7 (22%) CR/CRu's, even after 2–4 prior rituximab-regimens, and 17 non-FL pts had 6 (38%) OR's, with 1 CRu in a marginal zone NHL pt. At a median follow-up of 11 mo., 9/21 pts with ORs are continuing responses, including 4 long-lived responses (15–20 mo). The evaluated pts include 17 pts at 120 mg/m2 who had 5 (29%) ORs with 3 (17%) CR/CRu's. Responses at 80 mg/m2 remain to be evaluated, but B-cell depletion occurs after the 1st infusion even at this low dose. Conclusions: hA20 appears well-tolerated, with no evidence of significant adverse events other than minor infusion reactions, even at short infusion times. B-cell depletion and responses have occurred at all doses evaluated, with no clear-cut evidence of a dose-response. As such, the study is continuing to confirm the efficacy of lower doses.

No significant financial relationships to disclose.

Characterisation of a dendritic cell subset in synovial tissue which strongly expresses Jak/STAT transcription factors from patients with rheumatoid arthritis

OBJECTIVES

To characterise the phenotype of the putative dendritic cells strongly expressing Jak3 and STAT4, which have been previously identified in the synovial tissue of patients with active rheumatoid arthritis (RA).

METHODS

Synovial biopsy specimens were obtained at arthroscopy from 30 patients with active RA (42 synovial biopsies). Immunohistological analysis was performed using monoclonal antibodies to detect dendritic cell subsets, including activation markers and cytokines relevant to dendritic cell function. Co-localisation of cell surface markers and cytokines was assessed primarily using sequential sections, with results confirmed by dual immunohistochemistry and immunofluorescence with confocal microscopy.

RESULTS

The dendritic cells identified in RA synovial tissue that strongly express Jak3 also strongly express STAT4 and STAT 6 and are correlated with the presence of serum rheumatoid factor. These cells are not confined to a single dendritic cell subset, with cells having phenotypes consistent with both myeloid- and plasmacytoid-type dendritic cells. The activation status of these dendritic cells suggests that they are maturing or mature dendritic cells. These dendritic cells produce IL12 as well as interferon alpha and gamma.

CONCLUSIONS

The close correlation of these dendritic cells with the presence of serum rheumatoid factor, a prognostic factor for worse disease outcome, and the strong expression by these cells of components of the Jak/STAT transcription factor pathway suggest a potential therapeutic target for the treatment of RA.

Prediction of response to therapy with clarithromycin/lenalidomide/dexamethasone (BIRD) in multiple myeloma using FDG-PET

17530

Background: End points based on functional imaging data hold promise to better define and stratify response. As a metabolic imaging modality, FDG-PET can characterize tumor aggressiveness and thus can serve as an early surrogate for therapy response. The combination therapy with BIRD augments tumor mass reduction and improves response in patients with multiple myeloma (MM). The purpose of this study is to determine the value of pre-therapy FDG-PET in predicting therapy response in MM patients undergoing BIRD therapy. Methods: A total of 13 patients with MM (mean age: 60 ± 11) underwent a whole body FDG-PET scan at initial staging prior to BIRD therapy. FDG uptake was qualitatively evaluated in 5 different patterns:minimally diffuse (score 1), focal (score 2), multifocal (score 3), diffuse (score 4) and extramedullary (score 5). Standardized uptake values (SUVmax) were obtained in osseous and extramedullary lesions for quantitative evaluation. Mean SUVmax were also calculated in 14 representative anatomic sites in the axial and appendicular skeleton in 20 age-matched control patients with no osseous malignancy. Ratios of the mean lesion SUVmax to the mean SUVmax in corresponding osseous sections from the control group were calculated. A score was obtained for each patient to reflect disease extent or severity by adding the ratios for each individual lesion. The qualitative and quantitative scores were correlated with the standard response criteria. Results: The results are summarized in the following Table . The pre-therapy qualitative and quantitative scores correlated well with the percent therapy response to BIRD regimen (r = −0.58, p = 0.04 and r = −0.53, p = 0.06, respectively). Conclusions: The pre-therapy FDG-PET scoring system we have developed appears to correlate with the subsequent therapy response to BIRD regimen. Expanded number of patients are warranted to confirm the results of this study.

[Table: see text]

No significant financial relationships to disclose.

FDG-PET predicts disease burden in multiple myeloma

7619

Background: Because of the clinical and biologic heterogeneity of multiple myeloma, staging systems have been developed based on recognition of various prognostic factors. The recent integration of FDG-PET into the diagnostic algorithm may also have prognostic implications. Our aim was to evaluate the value of FDG-PET in determining the extent of disease as a staging tool in MM and to compare PET results with the established staging systems and laboratory data. Methods: Thirty seven patients with MM (mean age: 62±12) underwent a whole body FDG-PET scan at initial staging prior to therapy. FDG uptake was qualitatively scored in the following patterns: minimally diffuse (score 1), focal (score 2), multifocal (score 3), diffuse (score 4) and extramedullary (score 5). Standardized uptake values (SUVmax) were obtained in 780 osseous and extramedullary sites for quantitative evaluation. Additionally, mean SUVmax was calculated in 14 representative anatomic sites in the axial and appendicular skeleton in 20 age-matched control patients with no osseous malignancy. Ratios of the mean lesion SUVmax to the mean SUVmax of corresponding osseous sections from the control group were calculated. A score was obtained for each patient to reflect disease severity by adding the ratio for each lesion. Qualitative and quantitative results were correlated with the tumor burden (paraproteins, free light chains in the serum) and staging scores of Durie-Salmon (D-S) and the international staging systems (ISS). Results: There was good correlation between the quantitative score and both D-S staging and the ISS. However, correlation was stronger with the D-S system compared to that with ISS (r=0.44, p=0.007 vs. r=0.33, p=0.06). There was also good correlation between the quantitative score and the tumor burden (r=0.37, p<0.05). The qualitative scoring system produced a good correlation with the tumor burden (r=0.35, p<0.05). There was no correlation between the qualitative scoring system and D-S staging or ISS (P>0.05). Conclusions: FDG-PET is useful in assessing the extent of disease as a staging tool at initial diagnosis in MM. The scoring system we have developed appears to correlate with the established staging systems and the level of free light chains which may contribute to the prognostic evaluation of patients with MM.

No significant financial relationships to disclose.

Phase I/II results of a second-generation humanized anti-CD20 antibody, IMMU-106 (hA20), in NHL

7530

Background: The humanized anti-CD20 antibody, IMMU-106 (hA20), has similar murine CDRs to rituximab, but the remaining framework is identical to humanized anti-CD22 IgG1 antibody, epratuzumab, whose safety and short infusion times have been reported. Methods: An open-label, multicenter, phase I/II, dose escalation study was conducted in adult patients with recurrent NHL to establish the safety, tolerance, PK, and immunogenicity (HAHA) of hA20 administered weekly x 4. Thirty-four patients have now received hA20 at 120 (n = 7), 200 (n = 6), 375 (n = 18) or 750 mg/m2 (n = 3). These were predominantly stage III/IV patients (n = 27) with follicular lymphoma (N = 23) who received 1–7 prior treatments (median, 2), including 1 (N = 22) or more (N = 9) rituximab regimens (without progression within 6 months). Results: Thirty-three patients completed all 4 hA20 infusions. Median infusion times at 375 mg/m2 were 3.1 h for 1st infusion, 2.0–2.3 h for subsequent infusions, and were generally shorter at lower doses. Fourteen patients (14%) had transient events, predominantly grade 1–2 events at 1st infusion. Antibody levels increased with hA20 dose; at 375 mg/m2, mean serum half-lives after 1st and 4th infusions were 3.4 ± 1.7 and 12.3 ± 3.9 days, respectively. With median follow-up now 3–6 months, peripheral blood B-cell depletion persists, HAHA evaluations are negative, and 14/23 patients (61%) with response assessments have objective responses by Cheson criteria. All 6 CR/CRu’s (23%) were in follicular lymphoma, occurred at all dose levels even at 120 mg/m2 (including patients with 2–4 prior rituximab-containing regimens ), and with 5/6 continuing. Conclusions: The tolerability, relatively short infusion times, and CR/CRu’s in patients with follicular lymphoma who relapsed after rituximab-containing regimens is encouraging. This study is continuing to assess response durability and to determine the optimal hA20 dose for subsequent studies.

[Table: see text]

Clarithromycin, lenalidomide and dexamethasone combination therapy as primary treatment of multiple myeloma

7545

Background: Lenalidomide (Revlamid [R]) is the leading clinical compound in a new group of drugs called IMiDs. Our group demonstrated that clarithromycin (Biaxin [Bi]) augments tumor mass reduction and improves responses in patients (pts) receiving low-dose thalidomide and/or dexamethasone (D). We report the results of the combination of Bi plus R plus D (BiRD) in newly diagnosed MM. Methods: A phase II trial designed to accrue 50 pts. A 2-stage design rejects a CR rate of < 10% (alt >30%). Between Nov. 2004 and Jan. 2006, 46 pts have been accrued of which 40 pts are eligible for evaluation. R is given po at 25 mg daily on days 1–21 of a 28-day cycle. D is given po at 40 mg once weekly. Bi is given po at 500 mg bid. Pts receive low dose aspirin (ASA)(81mg) qd as thrombosis (TE) prophylaxis. Responses are defined according to modified EBMTR criteria. Analysis is by intent-to-treat. Patient Selection: Median age: 62.5 years (36–80), Male/Female 25/15, Hgb: 10.6 g/dL (7.2–15.1), Plt 234 k/uL (51–526), β2m: 3 mg/L (0.8–12.8), CRP: 0.6 mg/dL (0.12–14.2), creat: 1.1 mg/dL (0.6–3.1), albumin 3.5 g/dL (2.3–4.9). SD stage IIIa: 48%, stage IIIb: 10% and IIa: 42%. ISS stage I: 50%, stage II: 25% and stage III: 25%. Cytogenetics and FISH: trisomy 11 (10 pts), tetrasomy 11 (3 pts), del13q14 (14 pts), t (4,14) (1pt), t (11,14) (3 pts). Results: Of the 40 evaluable pts, 38 (95%) have achieved an objective response (>PR) within 3–4 months of Rx with the remaining pts continuing to respond. Seventeen pts (43%) had a >90% reduction of the initial paraprotein. Nearly one third of pts have achieved either a CR (10/40) or a nCR (2/40-continuing on Rx). CR has been confirmed in all pts by normalization of free light chain levels and ratio. The remaining 26 pts (65%) achieved a PR. Of those pts who achieved a PR, 5/26 pts (19%) had >90% reduction in the initial paraprotein. Nineteen pts have experienced grade ≥3 adverse events. Heme toxicities: anemia (11%), neutropenia (9%) and thrombocytopenia (9%). Non-heme toxicities (NHT) include TE in 7 patients (15%) 2 of them fatal. Four of the TE events were while off ASA. Other NHT include myopathy (6%), GI (4%), and mood (4%). Conclusions: BiRD therapy is a safe and highly effective primary therapy for symptomatic, treatment-naïve MM.

[Table: see text]

FDG-PET versus Thallium-201 SPECT in the evaluation of putative CNS lymphoma in AIDS patients

1537

Background: The evaluation of CNS lesions in AIDS patients is challenging as both CNS lymphoma and non-neoplastic lesions can have similar clinical presentations and imaging findings. Both Tl-201 SPECT and FDG PET imaging have been used to differentiate malignancy from infection. This study investigates the accuracy of FDG PET compared to Tl-201 SPECT in the diagnosis of CNS lymphoma in patients with AIDS-associated CNS lesions. Methods: Nine patients with AIDS who were found to have rim enhancing brain lesions on MRI underwent both Tl-201 SPECT and FDG PET imaging prior to diagnosis. Diagnosis was made by stereotactic brain biopsy in 6 pts and clinical follow-up in the remaining 3. FDG PET of the brain was performed using a dedicated PET/CT instrument (GE Discovery) 1 hour after 444 MBq FDG. Brain SPECT was performed on a dual head gamma camera (GE Hawkeye) with 185 MBq Tl-201. Images were reviewed along with MRI for anatomic correlation by 2 experienced nuclear medicine physicians blinded to the diagnosis. Results: 43 MRI lesions in 9 patients were evaluated. Clinically, 5 pts (18 lesions) were diagnosed with lymphoma (4 biopsy proven, 1 with known history of lymphoma), and 4 pts (25 lesions) were diagnosed with toxoplasmosis (2 with negative biopsies for malignancy, 2 with clinical course consistent with toxoplasmosis). FDG PET had true positive results for lymphoma in 5 of 5 pts, while Tl-201 SPECT was true positive in only 2 of 5. FDG PET had true negative results in 4 of 4 pts with toxoplasmosis, while Tl-201 had false positive results in 2 of 4. FDG PET had positive and negative predictive values of 100%, while Tl-201 SPECT had PPV 50% and NPV 40%. On a lesion basis, PET showed increased uptake of FDG in 8 of 18 brain lesions in patients with lymphoma, while SPECT showed increased uptake of Tl-201 in 4 of 18 lesions. Tl-201 was positive in 2 lesions in patients diagnosed with toxoplasmosis, while FDG had no false positive lesions. Conclusion: In this limited study, FDG PET proved to be superior to Tl-201 SPECT in the differentiation of CNS lymphoma from toxoplasmosis (overall accuracy 100% vs 44%, respectively). With the increasing availability of FDG PET, this test should probably supplant Tl-201 SPECT as the study of choice following conventional imaging (CT, MRI) of CNS lesions in AIDS patients.

No significant financial relationships to disclose.

Insecticide resistance in Anopheles funestus (Diptera: Culicidae) from Mozambique

Malaria control in southern Mozambique is currently by indoor residual carbamate insecticide treatment, with pyrethroid-treated bed-nets distributed to pregnant women and children under five in northern Mozambique. The susceptibility of Anopheles funestus s.s. to pyrethroid, carbamate, organochlorine, and organophosphorus insecticides was determined by World Health Organization adult mosquito susceptibility tests at 19 localities in Mozambique, from March 2000 to July 2002. Biochemical assays were carried out on mosquitoes from the same families to detect shifts in the quantity or activity of enzyme families involved in insecticide detoxification. An. funestus from all localities remained fully susceptible to DDT and the organophosphorus insecticide malathion. A high level of pyrethroid resistance was detected in An. funestus populations in southern Mozambique. An. funestus outside Maputo province were still susceptible to pyrethroids. An. funestus from six localities also were resistant to carbamate insecticides propoxur and bendiocarb. Both pyrethroid and carbamate resistance occurred in five of these six localities. Mosquitoes from five of the localities with elevated p450 estimates, compared with the insecticide-susceptible Durban strain, were pyrethroid-resistant. The only exception to this trend was Mozal, which had elevated p450 estimates but full pyrethroid susceptibility by bioassay. The lack of cross-resistance between pyrethroids and DDT in Mozambican An. funestus suggests that a kdr-type target site resistance mechanism has not been selected. Low levels of insecticide-insensitive acetylcholinesterase, the target site for carbamates and organophosphates, were found in all populations tested. The high level of metabolically based pyrethroid resistance has implications for current malaria control programs in Mozambique.

Insecticide resistance in Anopheles arabiensis and Anopheles gambiae from Mozambique

Malaria control in the southern part of Mozambique is currently by indoor residual spraying with a carbamate insecticide and by pyrethroid-treated bed-nets distributed to pregnant women and children under five in northern Mozambique. The susceptibility of Anopheles gambiae s.s. and Anopheles arabiensis Patton to pyrethroid, carbamate, organochlorine, and organophosphorus insecticides was determined by World Health Organization adult mosquito susceptibility tests at 17 localities in Mozambique, from March 2000 to July 2002. Biochemical assays were carried out on mosquitoes from the same families to detect shifts in the quantity or activity of enzyme families involved in insecticide detoxification. An. gambiae s.s. from all localities remained fully susceptible to DDT and the organophosphorus insecticide malathion. A low level of pyrethroid resistance was detected in populations in southern Mozambique. Populations outside Maputo province were still susceptible to pyrethroids. Low level resistance to the carbamate propoxur also was detected in An. arabiensis from two localities. Mosquitoes from five of the localities had elevated p450 estimates, compared with the insecticide susceptible Durban strain. The lack of cross-resistance between pyrethroids and DDT in Mozambican populations suggests that a kdr-type target site resistance mechanism has not been selected. Increased frequencies of insecticide insensitive acetylcholinesterase, the target site for carbamates and organophosphates, were found in 16 of the populations tested. Although vector control with bendiocarb is not being compromised by the presence of the acetylcholinesterase mechanism alone, the high level of insensitive acetylcholinesterase unless sensibly managed may have long-term implications for malaria control programs in Mozambique.

Renal prothrombin mRNA is significantly decreased in a hyperoxaluric rat model of nephrolithiasis

Although urinary prothrombin fragment 1 (UPTF1) possesses several hallmarks expected of a regulatory protein in urolithiasis, its precise role remains unknown. To determine the relationship between renal prothrombin (PT), the parent molecule of UPTF1, and lithogenesis, this study quantified and compared levels of renal PT mRNA in healthy rats (n = 10) and rats rendered lithogenic (n = 10) by ingestion of 0.75% ethylene glycol for 8 weeks. Studies included morphological and histological examination of the kidneys with scanning electron microscopy of the urinary filtrates of control and experimental animals. Haematuria and calcium oxalate (CaOx) crystals occurred in the urine of all experimental rats, but not in those of controls. Histological examination showed birefringent nephroliths and associated damage in kidneys of lithogenic rats, which were not seen in the control group. The amounts of total RNA extracted from both groups of rats were similar, but the median ratio of PT to beta-actin transcript of 11.14 x 10(-4) (10.65 x 10(-4) +/- 2.24 x 10(-4)) in the control rats was significantly (p < or = 0.001) reduced to 6.47 x 10(-4) (6.57 x 10(-4) +/- 2.72 x 10(-4)) in the lithogenic group. These results demonstrate that renal PT mRNA is reduced by approximately 42% in lithogenic rats and confirm the existence of a direct association between renal PT synthesis and calculogenesis. Attempts to compare renal PT and urinary levels of PTF1 were unsuccessful because of interference from hepatic PT circulating in the blood, haematuria, and the presence of urinary CaOx crystals. This is the first report of a significant reduction in the renal expression of a urinary protein well documented to inhibit CaOx crystal growth and aggregation in undiluted human urine in vitro.

The Jak-STAT pathway in rheumatoid arthritis

BACKGROUND

Modulation of Jak-STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis (IA).

OBJECTIVE

To examine the effect of successful disease-modifying antirheumatic drug (DMARD) treatment on the expression of Jak-STAT in a cohort of patients with active rheumatoid arthritis.

METHODS

Synovial tissue biopsy specimens from 16 patients with active rheumatoid arthritis, taken before and after initiation of DMARD treatment, were examined for the presence of janus kinase (Jak)3, signal transducer and activator of transcription (STAT)1, STAT4 and STAT6 expression using immunohistochemistry.

RESULTS

Successful treatment with DMARDs results in reduction in STAT1 expression in the lining, and STAT1 and STAT6 in the sublining of rheumatoid arthritis synovial tissue. Although the overall expression of STAT4 and Jak3 was not significantly altered by DMARD treatment, there was a significant reduction in the expression of the STAT4 and Jak3 bright cells, thought to be an activated dendritic cell subpopulation.

CONCLUSION

Results show that Jak3, STAT1, STAT4 expression and STAT6 sublining expression decrease in response to successful treatment of rheumatoid arthritis with standard DMARDs. Therefore, altering the expression of these pathways may represent an alternative treatment option, either through promoting up-regulation of inhibitory pathways, or suppressing inflammatory paths.

Measuring the quality of referral letters about patients with upper gastrointestinal symptoms

BACKGROUND

General practitioners state the reason for referring patients in referral letters. The paucity of information in these letters has been the source of criticism from specialist colleagues.

OBJECTIVE

To invite general practitioners to set standards for referral letters to gastroenterologists and to apply these standards to actual referral letters to one specialist gastroenterology unit.

METHODS

A scoring schedule was designed based on the responses to a questionnaire survey of a large sample of all general practitioners in one locality. Altogether 350 consecutive letters to a district general hospital about patients referred for an upper gastrointestinal specialist opinion were subsequently scored using the schedule.

RESULTS

102 practitioners responded to the survey. Their responses imply that colleagues assess and record findings on 18 potential features of upper bowel disease. In practice most referral letters address fewer than six features of upper bowel disease. The mean number of positive features of upper gastrointestinal disease reported in each letter was one.

CONCLUSIONS

This study reported a failure to meet "peer defined" standards for the content of referral letters set by colleagues in one locality. Referral letters serve many purposes, however, encouraging full documentation of specific clinical findings may serve to increase the pre-referral assessments performed in practice.

Neurophysiological and subjective profile of marijuana with varying concentrations of cannabinoids

This study investigated the contribution of different cannabinoids to the subjective, behavioral and neurophysiological effects of smoked marijuana. Healthy marijuana users (12 men, 11 women) participated in four sessions. They were randomly assigned to a low or a high delta9-tetrahydrocannabinol group (THC; 1.8% versus 3.6%). In the four sessions under blinded conditions subjects smoked marijuana cigarettes containing placebo (no active cannabinoids), or cigarettes containing THC with low or high levels of cannabichromene (CBC; 0.1% versus 0.5%) and low or high levels of cannabidiol (CBD; 0.2% versus 1.0%). Dependent measures included subjective reports, measures of cognitive task performance and neurophysiological measures [electroencephalographic (EEG) and event-related potential (ERP)]. Compared to placebo, active THC cigarettes produced expected effects on mood, behavior and brain activity. A decrease in performance, reduction in EEG power and attenuation of ERP components reflecting attentional processes were observed during tests of working memory and episodic memory. Most of these effects were not dose-dependent. Varying the concentrations of CBC and CBD did not change subjects' responses on any of the outcome measures. These findings are consistent with previous studies indicating that THC and its metabolites are the primary active constituents of marijuana. They also suggest that neurophysiological EEG and ERP measures are useful biomarkers of the effects of THC.

Expression of Jak3, STAT1, STAT4, and STAT6 in inflammatory arthritis: unique Jak3 and STAT4 expression in dendritic cells in seropositive rheumatoid arthritis

BACKGROUND

Modulation of Jak-STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis.

OBJECTIVE

To document Jak-STAT expression in a cohort of patients with active rheumatoid arthritis (RA), spondyloarthritis (SpA), and osteoarthritis (OA) and compare these subsets with normal synovial tissue.

METHODS

Synovial tissue biopsy specimens from patients with RA, OA, and SpA and histologically normal tissue (n = 10 in each arthritis group) were examined for the presence of Jak3, STAT1, STAT4, and STAT6 expression using immunohistochemistry. Phenotyping was performed using immunohistochemistry and immunofluorescence. Clinical and serological characteristics of patients with RA expressing Jak3-STAT4 were assessed.

RESULTS

STAT1, STAT4, and Jak3 protein expression was generally increased in inflammatory arthritis. In contrast, STAT6 expression was relatively heterogeneous. A subpopulation of CD1a positive dendritic cells unique to seropositive patients with RA was detected. These cells showed intense protein expression for Jak3, STAT4, and STAT6.

CONCLUSION

CD1a positive dendritic cells intensely express Jak3, STAT4, and STAT6 in seropositive RA tissue and may be an alternative marker for dendritic cells in their early stages of activation as well as providing a tool for identifying RA at the level of the synovium. Jak3 inhibition may be a potential therapeutic target to prevent dendritic cell maturation in RA. STAT1 expression is increased in inflammatory arthritis, suggesting that its pro-apoptotic and anti-inflammatory effects cannot effectively counteract inflammation. STAT6 expression is heterogeneous in synovium, suggesting a possible homoeostatic role in addition to any anti-inflammatory effects.

Isolated pulmonary hypertension in scleroderma

BACKGROUND

Isolated pulmonary hypertension (PHT) is now the most frequent cause of disease-related death in limited cutaneous scleroderma, the commonest disease variant of this disabling connective tissue disorder. Endothelin-1 receptor antagonists provide symptomatic benefit but to date have not been shown to prolong survival.

AIM

To determine the frequency, disease characteristics and survival of symptomatic patients with isolated PHT in our cohort of scleroderma patients.

METHODS

Systematic review of the clinical course of all patients registered on the South Australian Scleroderma Register, a population-based register of 374 living and 234 deceased patients with scleroderma.

RESULTS

Thirty-four patients were identified with isolated PHT, the majority with limited scleroderma. From our deceased register, we estimate that >11% of patients with this limited variant will develop this complication. Isolated PHT occurs as a late-stage complication approximately 20 years after the first symptoms of scleroderma. Patients with isolated PHT were characterized by the presence of multiple telangiectasia, reduced nailfold capillary density, digital ulceration, gross reduction of diffusing capacity for carbon monoxide and echocardiographic evidence of elevated pulmonary artery pressure. Survival was significantly shortened as compared with those patients without this complication (P=0.002), with a mean survival of 2.5 years from symptomatic onset of PHT.

CONCLUSION

Isolated PHT occurs as a late-stage complication in > or =11% of patients with limited cutaneous scleroderma and leads to rapid death from right heart failure. The early use of endothelin-1 receptor antagonists may change the natural history of this fatal complication.

CD20-negative large-cell lymphoma with plasmablastic features: a clinically heterogenous spectrum in both HIV-positive and -negative patients

BACKGROUND

Plasmablastic lymphoma (PBL) has been described as a rapidly progressive and almost invariably fatal CD20- VS38c+ diffuse large-cell lymphoma with plasmablastic features, almost exclusively involving the jaw and oral mucosa in HIV-positive patients.

METHODS

From 2001 to 2003 we evaluated 12 men with PBL, and report the pathology, clinical findings, treatment and outcome. Six of 12 were HIV-positive while among the others, one was post-renal transplant, one had ulcerative colitis and four had no known immunodeficiency.

RESULTS

Tumor growth pattern, in general, showed cohesiveness and a starry-sky pattern; the morphology varied from typical plasmablastic to centroblastic cells. Partial immunophenotypes were (+/total): CD138, 11 of 12 (91.7%); MIB1 10 of 11 (4+, range 75-95%); p63/VS38c, nine of 10 (90%); EBV, eight of 11 (73%); LCA(CD45), two of 12 (16.7%); HHV8/LANA, zero of 10; ALK, zero of seven; and CD20, zero of 12. Three had stage IE and nine stage IV disease. Nine of 12 had an intermediate/high International Prognostic Index or high-risk disease. Computed tomography and positron emission tomography scan in four of 12 revealed extensive bone metastases. Eight of 12 are alive after treatment, with a median follow-up of 11+ months (range 1-24). Of the HIV-positive patients, five of six are alive with a median follow-up of 17 months.

CONCLUSIONS

It appears that PBL are heterogenous in terms of clinical presentation and morphology. The outcome presented here is superior to that originally reported.

Plasticity of face processing in infancy

Experience plays a crucial role for the normal development of many perceptual and cognitive functions, such as speech perception. For example, between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the ability to discriminate among foreign speech sounds declines. However, a recent investigation suggests that some experience with non-native languages from 9 months of age facilitates the maintenance of this ability at 12 months. Nelson has suggested that the systems underlying face processing may be similarly sculpted by experience with different kinds of faces. In the current investigation, we demonstrate that, in human infants between 6 and 9 months of age, exposure to non-native faces, in this case, faces of Barbary macaques (Macaca sylvanus), facilitates the discrimination of monkey faces, an ability that is otherwise lost around 9 months of age. These data support, and further elucidate, the role of early experience in the development of face processing.

Female preponderance in congenital adrenal hyperplasia due to CYP21 deficiency in England: implications for neonatal screening

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase (CYP21) deficiency causes symptoms ranging from life-threatening neonatal adrenal crises to minimal virilization in adulthood. The relationship between CYP21 genotype and phenotypic markers in a non-screened population of 73 CAH children (44 female, 29 male; 54 white, 19 Asian) treated at the Royal Manchester Children's Hospital was investigated and ethnic and sex differences assessed. The patients were categorized according to the mutation on the mildest allele. The age at the time of diagnosis differed significantly between the groups (p = 0.02): all 25 Null and 25 of 26 of the I2 splice patients were diagnosed during the neonatal period, whereas 7 of 11 I172N patients were diagnosed late. Degree of female genital virilization, 17-hydroxyprogesterone level at diagnosis, and fludrocortisone requirement during the 1st year of treatment correlated with the genotype, although Asian Null patients required more fludrocortisone than their white counterparts (p = 0.055). There was an equal sex ratio in both the I2 splice (12 female/14 male) and I172N (5 female/6 male) groups. However, in the Null group, the ratio was 4.0 (20 female/5 male; p = 0.003), suggesting that some Null male infants perish before being clinically detected to have CYP21 deficiency. Our findings strongly support the need for implementation of a neonatal screening programme for CAH in the UK which may reduce the male infant mortality.