Dolutegravir resistance in Malawi’s national HIV treatment program

Dolutegravir HIV drug resistance (HIVDR) data from Africa remain sparse. We reviewed HIVDR results of Malawians on dolutegravir-based antiretroviral therapy (November 2020–September 2021). Of 6462 eligible clients, 33 samples were submitted to South Africa, 27 were sequenced successfully, and 8 (30%) had dolutegravir HIVDR. Malawi urgently requires adequate HIVDR testing capacity.

Thyroid and Parathyroid Neoplasms with Lipomatous Stroma: Report of Three Cases and Review of the Literature

Introduction/Objective

Tumors with mixed adipose tissue and epithelial components are rare in thyroid and parathyroid glands. Most of them are benign and referred to as adenolipoma (or lipoadenoma). A handful of malignant tumors of thyroid follicular cell origin have been reported with abundant adipose tissue known as thyroid carcinoma with lipomatous stroma (TCLS). Adenolipomas of thyroid or TCLS are usually manifested as large thyroid nodules and evaluated by fine needle aspiration biopsy (FNAB) which frequently yield low-cellularity samples due to abundant adipose tissue. On FNAB, the adipose tissue usually interpreted as contamination of subcutaneous or perithyroid origin. Similarly, adenolipomas of the parathyroid are not frequently identified because of presence of adipose tissue which is a feature associated with normal parathyroid glands. Therefore, these tumors are not often correctly diagnosed preoperatively. For that reason, pathologist should report additional cases about this rare entity to increase our understanding and to decrease preoperative diagnostic error.

Methods

We report three cases of thyroid and parathyroid tumors with abundant adipose tissue with sonographic, cytologic and histologic features along with literature review.

Results

Among the reported cases in the literature and our cases; 10 out of 17 cases of thyroid carcinoma with lipomatous stroma are papillary thyroid carcinomas (58.8%), 3 out of 17 cases are papillary microcarcinomas (17.6%), 2 out of 17 cases are noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) (11.7%), and 2 out of 17 cases are minimally invasive follicular carcinomas (11.7%). No cases of poorly differentiated or anaplastic thyroid carcinomas have been reported.

Conclusion

Lipomatous stroma in thyroid carcinoma appears to be associated with differentiated carcinomas since no reported cases of poorly differentiated or anaplastic thyroid carcinomas are present to our knowledge. Although the presence of fatty tissue does not appear to alter the prognosis of these lesions, the question of the histogenesis of the adipose component is intriguing. Awareness of this unusual feature and increased utilization of multimodal approaches in the evaluation of this entity may increase preoperative detection and the understanding of the histogenesis and its possible significance.

The influence of whole-body vibration on heart rate, stride length, and bone mineral content in the mature exercising horse

Research in humans suggests whole-body vibration (WBV) aids in maintaining bone mineral content (BMC) yet results in the horse are less favourable. Anecdotally, WBV is reported to reduce pain and improve performance. This study was designed to test the effect of WBV on exercising horses, hypothesising that WBV would lower heart rate (HR) during treatment, increase BMC, modify markers of bone metabolism, and increase stride length. Eleven horses were randomly assigned into control (CON, n=5) or WBV (VIB, n=6) groups for a 28-day treatment period. Both groups exercised for 1 h, 6 d/wk on a mechanical exerciser. VIB horses received 50 Hz WBV for 45 min, 5 days/wk. Third metacarpal radiographs were taken at 0 and 28 days, and BMC determined via radiographic bone aluminium equivalence (RBAE). Blood samples taken at day 0 and 28 were analysed for serum pyridinoline cross-links (PYD) and osteocalcin (OC). Heart rate was analysed on day 23 for 4 horses per group. Stride length was determined while trotting in hand on day 0 and 28. No influence of WBV on RBAE of any bone cortices, PYD or OC was observed (P>0.10); stride length was also unaffected (P=0.88). A period effect was observed for a decrease in RBAE of the lateral cortex (P=0.01), and a trend towards a decrease was noted in total density (P=0.05), likely an effect of stalling. Compared to baseline, ΔHR declined during treatment (P=0.06) in VIB (-4.8±2.8 bpm) compared to control CON (3.0±2.8 bpm). The results suggest, in normal exercising horses, WBV does not increase BMC, influence markers of bone metabolism, or increase stride length.

OP0045 DELINEATION OF A PROINFLAMMATORY CYTOKINE PROFILE TARGETED BY JAK1/2 INHIBITION USING BARICITINIB IN A PHASE 2 SLE TRIAL

Background:

Given the unmet clinical needs in systemic lupus erythematosus (SLE), including poor disease control and drug toxicities, new therapies are needed. In a phase 2, randomized, placebo-controlled, double-blind study (JAHH), once-daily baricitinib (bari) resulted in significant clinical improvement in patients (pts) with active SLE versus PBO. Bari inhibits JAK1 and JAK2 signalling, and in turn may affect STAT1, STAT2, STAT4 pathways. Therefore, bari has the potential to simultaneously impact several pro-inflammatory immune cytokines implicated in the pathogenesis of SLE, including IFN-α, IFN-γ, IL-6, IL-12, and IL-23.

Objectives:

The objectives of the current study were: 1) to examine baseline serum cytokines in the JAHH phase 2 clinical trial for correlations with clinical or immunologic assessments; 2) to determine if changes in serum cytokine levels were associated with bari treatment.

Methods:

Pts enrolled in the JAHH phase 2 trial received daily treatment with PBO, bari 2 mg, or bari 4 mg through week 24. Serum samples were collected at baseline (week [wk] 0), wk 12, and wk 24) from SLE pts (n=270) and 50 sex- and age-matched controls. Samples were analyzed for: IL-2, IL-3, IL-5, IL-6, IL-10, IL-17A, IL-21, IL-12/23p40, IL-12p70, GM-CSF, IFN-α and IFN-γ using ultrasensitive quantitative assays. IFN gene signature, autoantibodies, C3 and C4 were measured as previously described [1].

Results:

At wk 0, serum IL-17A, IL-12/23p40, IL-6, IFN-γ and IFN-α were readily detectable. IL-12/23p40 was detectable in 100% of pts vs. 100% of controls, IFN-γ in 89% of pts vs. 66% of controls, IL-6 in 53% of pts vs. 12% of controls and in IFN-α 41% of pts vs. 2% of controls; detection of serum IL-2, GM-CSF, IL-5, IL-10 and IL-17A was variable (Fig 1). At baseline (wk 0), IL-12/23p40 was positively correlated with SLEDAI and IFN gene signature and negatively correlated with serum C4. IL-6 was positively correlated with joint swelling, joint tenderness, IFN-γ and C3. Serum IFN-α was positively correlated with serum IFN-γ, anti-Sm and anti-RNP, and the IFN gene signature (Fig 2). Treatment with bari 4 mg (Fig 1B) significantly decreased serum IL12/23p40 and IL-6 cytokine levels at wk 12 (p<0.05) but not serum IFN-α or IFN-γ levels (Fig 1B).

Figure 1.

* p = 0.015; ** p = 0.001; Abbreviations: LLOQ, Lower limit of quantification.

Figure 2.

Abbreviations: Anti-dsDNA, Anti-double stranded DNA; Anti-RNP, Anti-ribonucleoprotein; CLASI, Cutaneous lupus erythematosus disease area and severity index; SLEDAI, SLE disease activity index.

Conclusion:

Bari 4 mg treatment was associated with statistically significant decreases of serum IL-12/23p40 and IL-6 at week 12 which continued through week 24. Serum IFN-α or IFN-γ were not reduced with bari treatment. Thus, bari 4 mg simultaneously impacted multiple pro-inflammatory cytokines implicated in the pathogenesis of SLE.

References:

[1]Hoffman RW, et al.Arthritis Rheumatol.2017;69(3):643-654.

Disclosure of Interests:

Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin, Michelle A Petri Grant/research support from: GSK, Eli Lilly and Company, Consultant of: Eli Lilly and Company, Josef S. Smolen Grant/research support from: AbbVie, AstraZeneca, Celgene, Celltrion, Chugai, Eli Lilly, Gilead, ILTOO, Janssen, Novartis-Sandoz, Pfizer Inc, Samsung, Sanofi, Consultant of: AbbVie, AstraZeneca, Celgene, Celltrion, Chugai, Eli Lilly, Gilead, ILTOO, Janssen, Novartis-Sandoz, Pfizer Inc, Samsung, Sanofi, Daniel Wallace Consultant of: Amgen, Eli Lilly and Company, EMD Merck Serono, and Pfizer, Brenda Crowe Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Ernst Dow Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Richard E Higgs Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Guilherme Rocha Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Robert Benschop Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Maria Silk Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Stephanie de Bono Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Robert Hoffman Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Damiano Fantini Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company

A phase I study of panobinostat and ruxolitinib in patients with primary myelofibrosis (PMF) and post--polycythemia vera/essential thrombocythemia myelofibrosis (post--PV/ET MF)

Ruxolitinib, a selective JAK1/JAK2 inhibitor, is the current first line therapy for myelofibrosis (MF), which reduces symptomatology and splenomegaly, but does not clearly modify disease course. Panobinostat, a histone deacetylase inhibitor, was shown to be safe and tolerable in phase I and II trials and demonstrated clinical activity in approximately a third of treated patients. Combination therapy of ruxolitinib and panobinostat showed synergistic activity in a preclinical MF model, which prompted clinical evaluation of this combination in both ruxolitinib naïve and treated MF patients. Herein, we report the results of an investigator-initiated, dose escalation, phase I trial of ruxolitinib and panobinostat in 15 patients with primary MF and post-polycythemia vera/essential thrombocythemia MF. This combination treatment proved to be safe and tolerable without dose limiting thrombocytopenia and a maximum tolerated dose of both agents in combination was not determined. The majority of patients maintained stable disease with this combination treatment and 40 % attained a clinical improvement (spleen n = 5, anemia n = 1) by modified IWG-MRT at the end of 6 cycles. This is one of the first attempts of rationally designed, JAK inhibitor-based, combination therapy studies and exemplifies the feasibility of such an approach in patients with advanced MF.

Which positive factors give general practitioners job satisfaction and make general practice a rewarding career? A European multicentric qualitative research by the European general practice research network

BACKGROUND

General Practice (GP) seems to be perceived as less attractive throughout Europe. Most of the policies on the subject focused on negative factors. An EGPRN research team from eight participating countries was created in order to clarify the positive factors involved in appeals and retention in GP throughout Europe. The objective was to explore the positive factors supporting the satisfaction of General Practitioners (GPs) in clinical practice throughout Europe.

METHOD

Qualitative study, employing face-to-face interviews and focus groups using a phenomenological approach. The setting was primary care in eight European countries: France, Belgium, Germany, Slovenia, Bulgaria, Finland, Poland and Israel. A thematic qualitative analysis was performed following the process described by Braun and Clarke. Codebooks were generated in each country. After translation and back translation of these codebooks, the team clarified and compared the codes and constructed one international codebook used for further coding.

RESULTS

A purposive sample of 183 GPs, providing primary care to patients in their daily clinical practice, was interviewed across eight countries. The international codebook included 31 interpretative codes and six themes. Five positive themes were common among all the countries involved across Europe: the GP as a person, special skills needed in practice, doctor-patient relationship, freedom in the practice and supportive factors for work-life balance. One theme was not found in Poland or Slovenia: teaching and learning.

CONCLUSION

This study identified positive factors which give GPs job satisfaction in their clinical practice. This description focused on the human needs of a GP. They need to have freedom to choose their working environment and to organize their practice to suit themselves. In addition, they need to have access to professional education so they can develop specific skills for General Practice, and also strengthen doctor-patient relationships. Stakeholders should consider these factors when seeking to increase the GP workforce.

Abstract P6-20-06: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Dann S, Chionis J, Eisele K, Zhang Q, Liu C, Yuan J, Miller N, Murray B, Xu M, Solowiej J, Wei P, Weinrich S, Sutton S, Behenna D, Ninkovic S, Hoffman R, Freeman-Cook K, Jessen B, Huser N, Zhang C, Visswanathan R, Boras B, VanArsdale T, White MA. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-20-06.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Environmental Toxins Found Historically in the Polycythemia Vera Cluster Area and their Potential for Inducing DNA Damage

In 2006, the Agency for Toxic Substances and Disease Registry received a request to determine whether a cluster of polycythemia vera patients existed in a northeast Pennsylvania community. A significant cluster of PV cases was identified at the nexus of three counties near several hazardous waste sites. The current study evaluated the potential for a select number of environmental contaminants previously detected in the cluster area to induce DNA damage using in vitro assays with hematopoietic stem-cell derived progenitor cells.

CD34+ cells were isolated from normal cord blood samples and were cultured for 48–72 hours to generate erythroid progenitor cells. Eighteen compounds were chosen for the assay; arsenic trioxide, benzo(a)pyrene, benzene, methylene chloride, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), trichloroethylene, potassium chloride, ethylbenzene, benzo[k]fluoranthene, styrene, cadmium chloride, hydroquinone, 1,1,1-trichloroethane, sodium cyanide, manganese chloride, chromium oxide, lead oxide, and sodium arsenite. Genotoxicity of the compounds was determined using the comet assay, and toxicity determined via the cell viability assay.

Using the comet assay, 16 compounds at 10 nM concentration, induced a significant amount of DNA damage compared to the control. When evaluating whether a dose-dependent relationship was present, seventeen of the eighteen compounds led to greater DNA damage with increasing exposure concentrations. 2,3,7,8-TCDD was particularly potent, inducing DNA damage in virtually all cells at 1 μM. In conclusion, most of the toxins evaluated using the comet assay showed potential to induce DNA damage in hematopoietic cells, and the genotoxic effects were dose-dependent.

Gestational Outcome in Thrombophilic Women with Recurrent Pregnancy Loss Treated by Enoxaparin

Inherited and acquired thrombophilia are associated with recurrent pregnancy loss (RPL). We have evaluated the efficacy and safety of the low molecular weight heparin enoxaparin in 50 women, (mean age 26 ± 3 years) with RPL (>3 losses in 1st, >2 losses in 2nd and >1 loss in 3rd trimester) who were found to harbor thrombophilia. Twentyseven had a solitary thrombophilic defect, and twenty-three women had combined thrombophilic defects: 17 – two defects and 6 – three defects. Following diagnosis of thrombophilia, sixty-one subsequent pregnancies were treated with the low molecular weight heparin enoxaparin throughout gestation until 4 weeks after delivery. Dosage was 40 mg/day in women with solitary defect and 80 mg/day in combined defects. Aspirin, 75 mg daily was given in addition to enoxaparin to women with antiphospholipid syndrome. Forty-six out of 61 (75%) gestations treated by enoxaparin resulted in live birth compared to only 38/193 (20%) of the untreated pregnancies in these 50 women prior to diagnosis of thrombophilia (p <0.00001). In 23 women without a single living child following 82 untreated gestations, antithrombotic therapy resulted in 26/31 (84%) successful deliveries (p <0.0001). In 20 women with a prior living child, antithrombotic therapy improved successful delivery from 33/86 (38%) to 20/21 (95%) (p <0.0001). Enoxaparin dose of 40 mg/day resulted in live birth in 24/35 (69%) of gestations, compared to 19/23 (83%) gestations in women treated with 80 mg/day (p = 0.37). Only one thrombotic episode and one mildbleeding episode were noticed during enoxaparin therapy. Enoxaparin is safe and effective in prevention of pregnancy loss in women with inherited and acquired thrombophilia.

Multicenter phase 2 study of combination therapy with ruxolitinib and danazol in patients with myelofibrosis

Myelofibrosis is a myeloproliferative neoplasm that is characterized by splenomegaly, profound symptom burden, and cytopenias. JAK inhibitor therapy offers improvements in splenomegaly, symptom burden, and potentially survival; however, cytopenias remain a significant challenge. Danazol has previously demonstrated improvements in myelofibrosis-associated anemia. We conducted a phase II clinical trial evaluating the efficacy and tolerability of combination therapy with ruxolitinib, an oral JAK inhibitor, and danazol. Fourteen intermediate or high-risk MF patients were enrolled at 2 institutions. Responses per IWG-MRT criteria were stable disease in 9 patients (64.2%) clinical improvement in 3 (21.4%) all of which were spleen responses, partial response in 1 (7.1%) and progressive disease in 1 (7.1%). Despite limited IWG-MRT response, stabilization of anemia and thrombocytopenia was demonstrated. In JAK inhibitor naïve patients, 4/5 (80%) had stable or increasing hemoglobin. Of the 9 patients on prior JAK inhibitor, 5 patients (55.5%) and 8 patients (88.9%) had stable or increasing hemoglobin or platelet levels, respectively. Adverse events possibly related included grade 3 or greater hematologic toxicity in ten patients (71.4%) and non-hematologic toxicity in two patients (14.3%). Although combination therapy did not lead to increased hematologic response per IWG-MRT criteria, hematologic stabilization was observed and may be clinically useful.

Polymeric Surface Modifications of Tantalum Stents

Purpose:

To compare two kinds of polymer-coated tantalum stents with bare tantalum stents (control) to determine if the coatings can improve thromboresistance.

Methods:

Twenty-seven Fontaine-Dake stents were balloon expanded in three 8-mm × 80-cm.polytetrafluoroethylene (PTFE) grafts; 9 stents were bare tantalum (T); 9 were coated with polyetherurethane (PL); and 9 were coated with parylene (PA). There were 9 stents placed in each graft as follows: 3 tantalum, 3 polyetherurethane, and 3 parylene. In swine whose platelets had been radiolabeled with indium 111, the ends of each stented graft were connected to 14F femoral and venous sheaths to create an ex vivo fistula. Each graft was exposed to blood for 30, 60, and 120 minutes. At the end of each test period, the stented grafts were disconnected from the sheaths, flushed with saline until clear, and then flushed with formalin. The stents were removed from the grafts, and a radionuclide well counter recorded radionuclide counts from each stent type at each period of blood contact. These values were converted to platelet density per 1000 mUm2. Stents were then photographed and scanned with electron microscopy (EM) for qualitative analysis. Possible significant differences in platelet adhesion with the three types of stents (both between stent groups and within stent groups) were examined using a two-tailed Student's f-test.

Results:

There were significantly fewer platelets adsorbed on PA versus T at all time periods (p < 0.005); on PL versus T at 60 and 120 minutes (p < 0.005); and on PA versus PL at 30 and 120 minutes (p < 0.0005). There was no significant difference in platelet density within each stent group (p = 0.1). Mean platelet density (number of platelets per 1000 mUm2 ± SD) was as follows: at 30 minutes: T = 1891 ± 965; PL = 373 ± 193; and PA = 27 ± 3; at 60 minutes: T = 6226 ± 1621; PL = 1573 ± 793; and PA = 1185 ± 710; at 120 minutes: T = 5307 ± 591; PL = 3164 ± 318; and PA = 180 ± 100. Gross inspection of the 120-minute groups demonstrated focal areas of thrombus on T, less on PL, and none on PA. Scanning EM demonstrated extensive platelet accumulation covering T at all time periods, less on PL, and even less on PA.

Conclusions:

Polymeric surface modification of tantalum stents with parylene and/or polyetherurethane can improve the acute thromboresistance of these devices; parylene appears to be the more thromboresistant of the two coatings.

Myeloma and thrombotic complications

Multiple myeloma (MM) is a hematological malignancy with high risk for thrombosis. While venous thromboembolism is more common, myeloma patients can also present with arterial thrombosis. Risk factors responsible for this complication can be patient-related, myeloma- and treatment-related. Thromboprophylaxis is indicated along with specific therapeutic regimens employed in myeloma patients. This review will cover potential risk factors for thrombosis in patients with multiple myeloma, prevention recommendations and treatment strategies in this clinical setting.

Histoculture and the immunodeficient mouse come to the cancer clinic - rational approaches to individualizing cancer-therapy and new drug-evaluation (review)

Originating from the experiments of Alexis Carrel, tissues in culture were originally grown in three dimensions and maintained important in vivo-like structural and functional properties. However, in modem times, monolayer cell culture methods have become predominant despite losses of structural and functional properties of the cells. Strangeways, Fell, Leighton, Sutherland and others have designed various methods of three-dimensional culture using cellulose supports, mesh supports, collagen gel or sponge supports and floatation that allow tissues to maintain many in vivo-like properties such as native architecture, differentiated functions, gene regulation, invasive properties and drug sensitivities which are very different than cells in monolayer cultures. Collagen-sponge-gel-supported histoculture has been shown to support the growth and native three-dimensional architecture of both tumor and normal tissue, often for long periods of time. This method of histoculture was utilized to develop a chemosensitivity assay for individual cancer patients by assessing the effects of drug on the patients' histocultured tumor. Various end points to measure drug response have been utilized in histoculture, including [H-3]thymidine incorporation measured by histological autoradiography and the use of vital dyes to indicate cell viability. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) end point was applied to the histoculture assay in an attempt to increase in vitro-in vivo correlation. The chemosensitivities of 16 human tumor lines were determined in vitro by the histoculture assay, and retrospectively correlated to their in vivo chemosensitivity as xenografts in nude mice. The overall correlation rate of the efficacy results of the drug-response assay to in vivo chemosensitivities was 89.8%, with 90.0% true-positive and 89.7% true-negative rates, 81.7% sensitivity and 94.6% specificity, thereby indicating potential clinical use for tumor histoculture with the MTT end point. The data reviewed and analyzed here thus indicate that three-dimensional culture systems offer much more realistic model systems for evaluating potential new cancer agents and individualized treatment such as predictive drug-response testing. The 'MetaMouse' model developed in our laboratory allows direct 'onplantation' of intact patient surgical cancer specimens orthotopically to athymic 'nude' mice with high-level expression of local growth on the target organ and high metastatic potential. Eight MetaMouse human cancer models are reviewed including those for the colon, bladder, lung, stomach, prostate, ovary, pancreas and head and neck. The human tumors growing and metastasizing in the mice reflect the clinical situation and should be useful for new drug evaluation and development of strategies for individual treatment. The combined technologies of histoculture and MetaMouse thus offer an integrated in vitro-in vivo system for preclinical evaluation of experimental and standard cancer therapy.

Patient-like nude-mouse and scid-mouse models of human lung and pleural cancer (review)

Lung cancer is one of the leading causes of cancer-related adult deaths in the world, and its incidence is rising. Patients with malignant pleural effusions are considered to be in the advanced-stage of malignant disease or in the terminal stage. For both, the lack of efficacy of non-surgical treatment modalities is related to the lack of suitable animal models for new drug discovery. Models based on athymic nude mice have been used for human cancer research. However, s.c. or i.m. xenografts usually do not metastasize, or do so at low frequencies. Conversely, human tumor cells orthotopically implanted in the corresponding organs of nude mice result in much higher metastatic rates. By avoiding disruption of tumor integrity, we have found that orthotopic implantation of histologically-intact patient specimens leads to models better reflecting the original behavior of human cancer than models constructed by orthotopic injection of cell suspensions. With the development of a novel thoracotomy procedure, we have constructed 'patient-like' models of lung cancer (SCLC and NSCLC) with regional spread and distant metastases mimicking the clinical features of these diseases. Moreover, by implantation of histologically-intact human tumor tissue in the parietal or visceral pleura of nude mice, we were able to construct models of early- and advanced-pleural cancer, respectively. Indeed, symptoms and survival of pleural-implanted mice closely resemble the clinical situation showing a statistically-significant difference in survival between parietal- and visceral-pleural implanted mice, the latter representing an advanced-stage cancer. Thus such models, reflecting clinical features, should be of great value in the development of new drugs and treatment strategies.