Cell size and actin architecture determine force generation in optogenetically activated cells

Adherent cells use actomyosin contractility to generate mechanical force and to sense the physical properties of their environment, with dramatic consequences for migration, division, differentiation, and fate. However, the organization of the actomyosin system within cells is highly variable, with its assembly and function being controlled by small GTPases from the Rho family. To understand better how activation of these regulators translates into cell-scale force generation in the context of different physical environments, here we combine recent advances in non-neuronal optogenetics with micropatterning and traction force microscopy on soft elastic substrates. We find that, after whole-cell RhoA activation by the CRY2/CIBN optogenetic system with a short pulse of 100 ms, single cells contract on a minute timescale in proportion to their original traction force, before returning to their original tension setpoint with near perfect precision, on a longer timescale of several minutes. To decouple the biochemical and mechanical elements of this response, we introduce a mathematical model that is parametrized by fits to the dynamics of the substrate deformation energy. We find that the RhoA response builds up quickly on a timescale of 20 s, but decays slowly on a timescale of 50 s. The larger the cells and the more polarized their actin cytoskeleton, the more substrate deformation energy is generated. RhoA activation starts to saturate if optogenetic pulse length exceeds 50 ms, revealing the intrinsic limits of biochemical activation. Together our results suggest that adherent cells establish tensional homeostasis by the RhoA system, but that the setpoint and the dynamics around it are strongly determined by cell size and the architecture of the actin cytoskeleton, which both are controlled by the extracellular environment.

3D-printed scaffold combined to 2D osteoinductive coatings to repair a critical-size mandibular bone defect

The reconstruction of large bone defects (12 cm³) remains a challenge for clinicians. We developed a new critical-size mandibular bone defect model on a minipig, close to human clinical issues. We analyzed the bone reconstruction obtained by a 3D-printed scaffold made of clinical-grade polylactic acid (PLA), coated with a polyelectrolyte film delivering an osteogenic bioactive molecule (BMP-2). We compared the results (computed tomography scans, microcomputed tomography scans, histology) to the gold standard solution, bone autograft. We demonstrated that the dose of BMP-2 delivered from the scaffold significantly influenced the amount of regenerated bone and the repair kinetics, with a clear BMP-2 dose-dependence. Bone was homogeneously formed inside the scaffold without ectopic bone formation. The bone repair was as good as for the bone autograft. The BMP-2 doses applied in our study were reduced 20- to 75-fold compared to the commercial collagen sponges used in the current clinical applications, without any adverse effects. Three-dimensional printed PLA scaffolds loaded with reduced doses of BMP-2 may be a safe and simple solution for large bone defects faced in the clinic.

Abstract PD9-07: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with high risk breast cancer (BC): Role of collagen processing and tumor microenvironment

Background: Copper is an important catalytic cofactor in several biological functions and is essential for lysyl oxidase (LOX), a key enzyme in cross-linking collagen, which may play a role in tumor metastasis. We hypothesized that tetrathiomolybdate (TM)-associated copper depletion (CD) would inhibit tumor metastases by altering copper dependent collagen remodeling in the pre-metastatic niche. These results are an update of our previously reported clinical outcomes with longer follow-up and translational outcomes implicating the tumor microenvironment in metastatic transformation of BC. Methods: Pts at high risk for recurrence, node+ triple negative (TNBC) or stage 3/4 BC with no evidence of disease (NED), were enrolled on a phase II study of CD with TM. TM was given to maintain ceruloplasmin (Cp) levels between 8-16 mg/dl for two years (yrs) with an extension phase or until relapse. Median Cp levels were monitored with each cycle. Clinical endpoints included safety/tolerability and progression of disease (POD)/death. Event-free (EFS) and overall survival (OS) were calculated using Kaplan Meier survival analyses. Translational endpoints included markers of collagen cross-linking (LOXL-2), formation (PRO-C3), and degradation (C1M and C6M). Results: Seventy-five pts received 2993 cycles of TM on the primary (24 cycles, 28 days per cycle) and extension study. Median age was 51 yrs (range 29-66). Forty-five pts had stage 2/3 BC, and 30 pts were stage 4 NED. At a median follow-up of 8.4 yrs, the overall EFS was 71.4% and OS was 78.8%. The EFS and OS for the 36 pts with TNBC were 71.7% and 81%, and the EFS and OS for the 39 pts with Luminal/HER2+ BC were 71.2% and 78.6% respectively. TM was well tolerated with grade 3/4 toxicities including: neutropenia (1.9%), febrile neutropenia (0.03%), and fatigue (0.2%). LOXL2 levels were significantly decreased at 12 and 24 cycles compared with baseline (p<0.01) in those who were NED but not in those who had progressive disease (POD). LOXL2 levels were significantly correlated with C1M levels (spearman coefficient -0.34, p=0.02). C1M levels were significantly increased at 5, 11 and 24 cycles as compared with baseline (p<0.01) in those who were NED and were significantly higher as compared to levels in those experiencing POD/death, p<0.05. This difference may be more pronounced in those not achieving adequate CD (<50%) and in luminal/HER2+ BC. Interestingly, the ratio of C1M/PRO-C3 was significantly more elevated over time in those NED as compared to those experiencing POD/death. No associations were found with other collagen markers (PRO-C3 and C6M). Conclusions: TM is safe, well-tolerated and associated with decreased LOXL-2 and increased C1M levels over time in NED pts. This suggests that copper depletion may result in decreased collagen crosslinking and increased collagen degradation over formation, potentially “normalizing” the collagen microenvironment to create an inhospitable environment for tumor metastases. Larger randomized trials in high risk populations with translational outcomes are needed to further investigate the role of collagen processing in the tumor microenvironment and its potential as a biomarker of response.

Citation Format: Liu YL, Bager CL, Willumsen N, Kornhauser N, Cobham M, Andreopoulou E, Cigler T, Moore A, LaPolla D, Fitzpatrick V, Ward M, Warren JD, Mittal V, Vahdat LT. A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with high risk breast cancer (BC): Role of collagen processing and tumor microenvironment [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 PD9-07.

Abstract P1-10-10: Tumor infiltrating lymphocytes (TILS) among high risk for recurrence breast cancer patients treated with tetrathimolybdate (TM)

Background: Tumor infiltrating lymphocytes (TILs) evaluated in the primary tumor biopsy or surgical resection have been well established as having prognostic significance in patients with triple negative breast cancer (TNBC) and HER2+ breast cancer treated with adjuvant chemotherapy (Savas et. al, Nat Rev Clin Oncol 2016). In TNBC, stromal TILs behave as a continuous variable with every 10% increase in TIL resulting in a decrease in risk of recurrence and death. The definition of lymphocyte-predominant breast cancer (LPBC) has been used for tumors that contain 50%–60% TILs and usually have a particularly good outcome (Salgado et al, Ann Oncol 2015). Our group recently demonstrated in a phase II single arm study that tetrathimolybdate (TM), a copper-depleting agent, resulted in improved event free survival (EFS) for TNBC patients compared to historical controls. The 2-year event-free survival (EFS) for stage 2-3 and stage 4 NED was 91% and 67%, respectively. In this analysis, our goal was to explore whether the encouraging results we observed were influenced by enrolling TNBC patients with better prognostic factors at initial diagnosis, namely higher stromal TIL score, in our copper depletion trial.

Methods: Archived primary breast tissue was available from 67 of the 75 patients enrolled in the phase II TM trial. The phase II study included patients with stage II TNBC or stage III or IV NED breast cancer patients, who were treated with TM for 2 years or until relapse. Here we focused on the 30 patients with TNBC. The demographic data for the patients is included in the following table.

Patient DemographicsAge at diagnosisStage at study entryPrior Adjuvant or Neoadjuvant therapyNumber of prior chemotherapy regimens in metastatic setting%Tumor Infiltrating Lymphocytes504Adjuvant110543AAdjuvantn/a30563AAdjuvantn/a20513CNeoadjuvantn/a<5454Adjuvant230514Neoadjuvant210363CAdjuvantn/a20592BAdjuvantn/a60453CAdjuvantn/a<5544Adjuvant130443CNeoadjuvantn/a20474Adjuvant020563CNeoadjuvantn/a10512AAdjuvantn/a10583AAdjuvantn/a20654None25513CNeoadjuvantn/a50503CNeoadjuvantn/a30543CNeoadjuvantn/a10542AAdjuvantn/a20403CNeoadjuvantn/a40604Adjuvant160564None160554Adjuvant010633CNeoadjuvantn/a5424Adjuvant050454Adjuvant110463AAduvantn/a10523CNeoadjuvantn/a10514Adjuvant1<5

The number of TILs in each sample was calculated by an experienced pathologist using published criteria (Salgado et al, Ann Oncol 2015). We used TILs >50% to define LPBC.

Results: Overall, we found that only 3/30 (10%) of TNBC patients had TILs >50%. In addition, 14/30 (46.7%) of TNBC patients had tumors with <10% TILs. The 2-year EFS for the patients with TILs >10% v. <10% was 76.9% v. 69.8%, respectively. (P=0.65)

Conclusions: Only 10% of TNBC patients enrolled in the study had LPBC at diagnosis thus indicating that this cohort was not enriched for patients with immunogenic tumors. When stratified by TILs >10% or <10%, there was no statistically significant difference in EFS. Although the analysis is limited due to the small sample size, it does suggest that the amount of TILs present at initial diagnosis did not influence the overall outcome for patients treated with TM.

Citation Format: Rybstein MD, Nackos E, Kornhauser N, Cigler T, Andreopoulou E, Moore A, Cobham M, Fitzpatrick V, Demaria S, Vahdat LT. Tumor infiltrating lymphocytes (TILS) among high risk for recurrence breast cancer patients treated with tetrathimolybdate (TM) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-10-10.

Abstract P1-10-02: A phase II study of copper-depletion using tetrathiomolybdate in patients with breast cancer at high risk for recurrence: Updated results

Background: Metals have emerged as a viable therapeutic target for a new generation of anti-cancer and anti-metastatic agents. Copper, an essential trace element, serves as an important catalytic cofactor in several biological functions and has emerged as an essential factor in carcinogenesis. Among other elements, bone marrow derived VEGFR2+ endothelial progenitor cells (EPCs) and copper-dependent lysyl oxidase (LOX) are key elements in tumor progression. We hypothesized tetrathiomolybdate (TM)-associated copper depletion (CD) inhibits tumor metastases by reducing the number of EPCs and other copper dependent processes in the pre-metastatic niche. These results are an update of our previously reported study (Chan N, Willis A, Kornhauser N et al. Influencing the Tumor Microenvironment: Phase 2 Study of Copper Depletion with Tetrathiomolybdate in High Risk Breast Cancer and Preclinical Models of Lung Metastases. Clin Cancer Res. October 21, 2016) with longer follow-up.

Methods: A single arm phase II study of breast cancer (BC) patients (pts) at high risk for recurrence, defined as node+ triple negative (TNBC), stage 3 and 4 with no evidence of disease (NED) were enrolled on a trial of CD with TM. TM was given to maintain ceruloplasmin (Cp) levels between 8-16 mg/dl for two years with an extension phase or until relapse. The primary endpoint was a change in EPCs measured by flow cytometry before and during treatment. Secondary endpoints included tolerability, safety, PFS and LOXL-2 levels.

Results: Seventy-five pts received 2778 cycles of TM on the primary and extension study. The primary study treatment duration was 24 cycles (each cycle is 28 days) plus an extension phase. The median age is 51 years (range 29-66). Forty-five pts have stage 2/3 BC and 30 with stage 4 NED. Forty-eight percent of pts are TNBC and 40% of pts are stage 4 NED. Median Cp levels were monitored with each cycle. A decrease from 28 to 16 (p<0.0001) was seen after one cycle. Interestingly, TNBC pts seemed to have a greater decrease from 23.5 to 13 after one cycle. TM was well tolerated with grade 3/4 toxicities including: reversible neutropenia (2.3%), febrile neutropenia (0.04%), fatigue (0.2%). Five-year analysis showed a decrease in EPC's (p=0.004) and LOXL-2 (p<0.001). At a median follow-up of 7.1 years, the EFS for 75 pts is 71.4%. The EFS for 36 pts with TNBC is 71.7%. EFS for stage 2/3 TNBC is 83% and for stage IV TNBC is 59.3%.

Conclusions: TM is safe, well tolerated and appears to affect multiple components of the tumor microenvironment that have been identified in pre-clinical models as important for progression. Ongoing studies in banked specimens are underway to further delineate its effect on copper dependent processes necessary for metastases. Randomized trials are warranted, especially in patients who are at high risk for relapse such as those with TNBC.

Citation Format: Sahota S, Willis A, Kornhauser N, Ward M, Cobham M, Cigler T, Moore A, Andreopoulou E, Fitzpatrick V, Schneider S, Prima N, Wiener A, Ko D, De Laurentiis A, Warren JD, Rubinchik A, Mittal V, Vahdat LT. A phase II study of copper-depletion using tetrathiomolybdate in patients with breast cancer at high risk for recurrence: Updated results [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-10-02.

Abstract P3-02-02: Targeting the tumor microenvironment: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with breast cancer (BC) at high risk for recurrence

Background: Bone marrow derived VEGFR2+ endothelial progenitor cells (EPCs) and copper-dependent pathways, including lysyl oxidase (LOX), are critical components to remodeling the tumor microenvironment and establishing the pre-metastatic niche. In preclinical models, it has been well established that copper depletion (CD) inhibits tumor progression. We hypothesized that TM-associated CD would reduce EPCs and other copper dependent processes in the pre-metastatic niche in BC pts at high risk for relapse. We investigated the relationship between CD and its effect on EPCs and other components of the tumor microenvironment including LOX, an enzyme critical for cross-linkage of collagen and priming the pre-metastatic niche.

Methods: In this single arm, phase II study, BC pts at high risk for recurrence, defined as node+ triple negative (TN), stage 3 and 4 with no evidence of disease (NED) were enrolled on a trial of CD with TM. Pts received oral TM to maintain ceruloplasmin (Cp) between 5-17 mg/dl for 2 years on the primary study. The primary endpoint was change in EPCs measured by flow cytometry before and during treatment with TM. Secondary endpoints included tolerability, safety and effect of copper depletion on other markers including LOX, quantified by ELISA.

Results: We enrolled 75 pts. The study treatment duration was 24 cycles (each cycle is 28 days). Over 2200 cycles have been administered. The median age is 51 (range 29-66). 45 pts have Stage 2/3 BC and 30 are Stage 4 NED. TNBC pts represent 48%, and 40% of pts are Stage 4 NED. Median Cp level decreased from 28 at baseline to 15.5 (p<0.0001) after one cycle. Copper depletion was most efficient in TNBC, with 91% achieving a target CP within 4 weeks. TM was well tolerated and the only grade 3/4 toxicities were reversible neutropenia (3.2%) and anemia (0.0005%). CD was associated with a significant decrease in EPCs (p=0.0014) and LOX (p<0.001). At a median follow-up of 5.4 years, the PFS for all 75 pts from the start of TM treatment was 71%, including a PFS of 90% for all stage 2/3 pts with TNBC. The overall survival of all patients enrolled in the trial is 86%. Relapse after two years is a rare event. Conclusions: TM is safe, well tolerated and appears to affect multiple copper dependent biologic processes in the tumor microenvironment known to be important for tumor progression. This seems to be most striking in TNBC. We believe, further phase III trials in a high risk for relapse population are warranted.

Citation Format: Nackos E, Willis A, Kornhauser N, Ward M, Andreopoulou E, Cigler T, Moore A, Fitzpatrick V, Cobham M, Schneider S, Wiener A, Guillaume-Abraham J, Warren JD, Rubinchik A, Lane M, Mittal V, Vahdat L. Targeting the tumor microenvironment: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with breast cancer (BC) at high risk for recurrence. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-02-02.

Climbing-specific finger endurance: a comparative study of intermediate rock climbers, rowers and aerobically trained individuals

The aim of this study was to compare the climbing-specific finger endurance of climbers, rowers and aerobically leg trained athletes. Twenty-seven males aged 21.2 +/- 2.2 years (mean +/- s) volunteered for the study. The participants were intermediate rock climbers (n = 9), rowers (n = 9) and leg trained athletes (n = 9). Maximal voluntary contraction (MVC) was determined on climbing-specific finger apparatus. Endurance isometric exercise was performed at 40% MVC in three tests performed in a random order: (1) sustained exercise; (2) 6 s exercise, 4 s rest; and (3) 18 s exercise, 12 s rest. Pre- and post-exercise blood pressure and blood lactate concentration, together with post-exercise pain perception, were measured. The climbers had a significantly greater MVC (383 +/- 35.6 N) than the rowers (321 +/- 49.5 N, P = 0.007) and aerobically leg trained athletes (288 +/- 60.6 N, P = 0.001). There were no significant differences between the groups in terms of endurance times for any of the tests. In the test with 18 s exercise and 12 s rest, the climbers showed a significantly higher increase in blood lactate concentration, on average, than the rowers by 0.01-0.89 mmol x l(-1) (P = 0.006); there were no significant differences, on average, in the comparisons of climbers and the leg trained athletes and rowers and the leg trained athletes. There were no significant differences in the average changes in blood pressure from rest to post-exercise between any of the groups. Although the climbers had greater MVC on average than the other two groups, there were no significant differences in average endurance times amongthe groups. These findings suggest that training for rock climbing and participation in rock climbing may result in some specific adaptations. However, we acknowledge that this study is descriptive and there is the possibility that differences between groups could be attributed to self-selection.

Pharmacists' job satisfaction and perceived utilization of skills

The relationship between job satisfaction and perceived utilization of skills among pharmacists practicing in institutional and ambulatory care settings in Arizona was studied, and factors thought to influence pharmacists' perceived utilization of skills were evaluated. Questionnaires on job satisfaction and perceived utilization of skills were mailed to a random sample of 600 pharmacists. Information on workplace factors such as hours worked, practice setting, and job title was collected. A 4-item measure of general job satisfaction and a 10-item measure of perceived utilization of skills were used. Responses were measured on a five-point Likert scale ranging from "strongly disagree" to "strongly agree." The response rate was 35%. There was a significant positive relationship between job satisfaction and perceived utilization of skills and between job satisfaction and adequate staffing, where "staffing" referred to factors such as competence of coworkers and workload. Pharmacists with training beyond a B.S. degree in pharmacy were more satisfied with their job than those whose highest degree was a B.S. in pharmacy. Pharmacists practicing in institutional settings, pharmacists with management titles, and older pharmacists perceived that they were utilizing their skills to a greater extent than did pharmacists practicing in ambulatory care settings, pharmacists with a general staff title, and younger pharmacists. Among a sample of Arizona pharmacists in institutional and ambulatory care settings, job satisfaction was influenced by perceived utilization of skills, staffing, and education; practice setting, job title, and age were significantly related to perceived utilization of skills.

Randomized, double-blind, placebo-controlled dose-ranging study of tirofiban (MK-383) platelet IIb/IIIa blockade in high risk patients undergoing coronary angioplasty

OBJECTIVES

The objectives of this double-blind, placebo-controlled, randomized dose-ranging study were 1) to examine the safety and tolerability of tirofiban (MK-383), a new nonpeptide platelet IIb/IIIa receptor antagonist, on a background of intravenous heparin and aspirin therapy; 2) to study the pharmacodynamics and pharmacokinetics of tirofiban; and 3) to evaluate the incidence of adverse cardiac outcomes (urgent repeat revascularization, myocardial infarction and death) with tirofiban versus placebo in a high risk subset of patients undergoing coronary angioplasty.

BACKGROUND

Abrupt vessel closure complicates 4% to 8% of angioplasty procedures. Recent data have suggested that agents that antagonize the platelet glycoprotein IIb/IIIa receptor may reduce the incidence of adverse ischemic outcomes after coronary angioplasty.

METHODS

Seventy-three patients received tirofiban in three sequential dose panels and 20 patients received placebo. Patients within each panel were randomized to receive either tirofiban or placebo in a 3:1 randomization design. Bolus doses of 5, 10 and 10 microg/kg and continuous infusion (16 to 24 h) doses of 0.05, 0.10 and 0.15 microg/kg per min were administered in panels I, II and III, respectively. Patients received concomitant heparin and aspirin for the angioplasty procedure. Data on patients receiving placebo (heparin and aspirin only) were pooled across panels for comparisons. The pharmacodynamic effect of tirofiban on ex vivo platelet aggregation to 5 micromol/liter adenosine diphosphate (ADP) and bleeding times were measured. Clinical outcomes were assessed in all patients, but the power to detect clinically meaningful differences (a one-third reduction in clinical events) between groups was limited (5%).

RESULTS

Tirofiban was associated with a dose-dependent inhibition of ex vivo ADP-mediated platelet aggregation that was sustained during intravenous infusion and resolved rapidly after drug cessation. Adverse bleeding events, largely related to vascular access site hemorrhage, were slightly increased at the highest dose. Adverse clinical outcomes were infrequent in all patients and were not different among the small number of patients within each group.

CONCLUSIONS

This study establishes a rational and generally well tolerated dosing regimen for administration of tirofiban as adjunctive therapy in high risk angioplasty patients. The impact of tirofiban on adverse clinical outcomes after angioplasty awaits definition by a larger clinical trial.

Effect of multiple doses of losartan on the pharmacokinetics of single doses of digoxin in healthy volunteers

1. Losartan (DuP 753, MK-954) is a novel, potent and highly selective AT1 angiotensin II receptor antagonist. The effect of multiple oral doses of losartan on digoxin pharmacokinetics was evaluated in healthy male subjects. 2. In a double-blind and randomized fashion, subjects received 50 mg losartan or placebo once daily for 15 days in each period. At least 7 days elapsed between the two treatment periods. On days 4 and 11 of each period, subjects also received a single 0.5 mg dose of digoxin intravenously and orally respectively. 3. Eleven of 13 subjects completed the study. Side effects were mild and transient (12 out of 13 subjects reported at least one adverse experience). During the study, no laboratory abnormalities were noted. 4. Multiple oral doses of losartan (50 mg daily) did not affect the pharmacokinetic parameters of 0.5 mg of digoxin i.v. AUC(0.48h) of immunoreactive digoxin during losartan 28.8 +/- 2.9 vs 28.5 +/- 3.9 ng ml-1 h during placebo; not significant, and 96 h urinary excretion [% dose] during losartan 54.0 +/- 7.2 vs 51.9 +/- 6.5% during placebo; not significant). Geometric mean ratios (90% confidence interval) for AUC and urinary excretion were respectively, 1.03 (0.98, 1.08) and 1.09 (0.98, 1.21). 5. Multiple oral doses of losartan did not affect the pharmacokinetic parameters of oral digoxin AUC(0.48 h) during losartan 23.6 +/- 3.7 ng ml-1 h vs 22.4 +/- 2.6 ng ml-1 h during placebo; not significant, Cmax 3.5 +/- 0.7 ng ml-1 with vs 3.1 +/- 0.5 ng ml-1 without losartan; not significant and tmax 0.6 +/- 0.2 h with vs 0.9 +/- 0.7 h without losartan; not significant, and 96 h urinary excretion [% dose] during losartan 51.2 +/- 6.3 vs 46.3 +/- 2.4% during placebo; not significant). Geometric mean ratios (90% confidence interval) for AUC and urinary excretion were respectively, 1.06 (0.98, 1.14) and 1.12 (0.97, 1.28). 6. We conclude that multiple oral doses of losartan (50 mg daily) do not alter the pharmacokinetics of immunoreactive digoxin, following either intravenous or oral digoxin. Furthermore, the co-administration of digoxin with losartan is well tolerated by healthy male volunteers.

Losartan potassium as initial therapy in patients with severe hypertension

This 12-week, open-label study was conducted to gain experience with losartan potassium, an angiotensin II receptor antagonist, in patients with severe hypertension. Patients were either untreated or withdrawn from current therapy for at least 48 h before initiation of losartan 50 mg once daily. Patients were titrated to 100 mg as needed to achieve a goal of sitting diastolic blood pressure (SiDBP) 90 or 95 mm Hg. Hydrochlorothiazide (12.5 mg once daily titrated to 25 mg) was added and followed by either a dihydropyridine calcium channel blocker (CCB) and/or atenolol, if BP was not controlled. A total of 179 patients with a pretreatment mean baseline BP of 172 +/- 17/112 +/- 18 mm Hg enrolled in the trial and BP was recorded 24 h after dosing at baseline and weeks 2, 4, 8 and the final week (10-12 weeks). The mean reductions in SiDBP from baseline were 7.3, 9.3, 15.9 and 18.9 mm Hg, respectively, and these changes from baseline were statistically significant, P < 0.001. At the end of the trial, 22% of patients remained on losartan monotherapy, 30% required the addition of hydrochlorothiazide (HCTZ) and 31% required both HCTZ and a CCB; 11% required HCTZ and atenolol while 4% required HCTZ, a CCB and atenolol; 2% of patients were on regimens not specified by the protocol. SiDBP < 90 mm Hg was achieved in 68 patients by the final visit; 24% of these patients were treated with losartan monotherapy (50 or 100 mg), 41% achieved control with the addition of HCTZ (12.5 or 25 mg) and 24% required triple therapy which included losartan, HCTZ and a CCB. As assessed by the investigator, 25% of the patients in the study had drug-related clinical adverse experiences. Headache was the most frequently reported clinical adverse event (26% of patients). No clinically significant changes in laboratory parameters were observed. It is concluded that losartan potassium can be used as initial therapy for patients with severe hypertension and can be administered concurrently with hydrochlorothiazide, calcium channel blockers and atenolol.

Social work in pediatric oncology: a family needs assessment

When a child is diagnosed with cancer, the family is confronted with meeting both the physical and psychosocial needs of the child and maintaining normal family functioning. This study assessed the perceived psychosocial needs of 77 families who have a child diagnosed with cancer. Preliminary results suggest practical application for social work interventions in specific areas such as the development of an informal support network, enhancement of communication within families concerning the disease, the need for adequate information at various stages of the disease, and continued supportive services for the family.

Trityl monitoring of automated DNA synthesizer operation by conductivity: a new method of real-time analysis

AutoAnalysis is a new method for detecting and quantitating the trityl cation released each cycle on automated DNA synthesizers. The trityl (dimethoxytrityl) cation is removed from the growing oligonucleotide after each base addition and is a useful measure of synthesis efficiency. The traditional absorbance method of collecting each trityl effluent with a fraction collector, followed by dilution with an acid solution and careful quantitation by UV/VIS spectroscopy is costly, tedious and prone to error. The absorbance method for trityl cation analysis must usually wait until the synthesis is complete. Interruption of a failed operation, for a variety of reasons, such as an empty reagent reservoir, is thus not possible. Taking advantage of the conductive properties of the trityl cation, immediate and real-time quantitation is now possible by integrating the total conductance of the flowing stream during the detritylation step after each nucleoside addition in DNA synthesis. A conductivity cell is mounted downstream, past the synthesis column. The conductivity signal is processed and displayed as the current average stepwise yield and overall yield. If the yield drops below a pre-set threshold value because of a failure situation, the synthesizer will interrupt, preserving reagents. AutoAnalysis allows trityl monitoring with complete automation on the Applied Biosystems Models 392 and 394 DNA/RNA Synthesizers.

Alternative fat-restricted diets for hypercholesterolemia and combined hyperlipidemia: feasibility, design, subject recruitment, and baseline characteristics of the dietary alternatives study

Dietary recommendations for the treatment of hypercholesterolemia (HC) emphasize stepwise reductions in fat intake, but there is no agreement on what lower limit is desirable or achievable. These recommendations have applied broadly to persons with HC alone, as well as to those with a combined elevation in triglyceride (TG) and cholesterol, even though they may differ in pathophysiological mechanisms and response. In this paper, we describe the design and feasibility of recruiting and randomizing subjects with HC or combined hyperlipidemia (CHL) to an outpatient dietary intervention study of progressively fat-restricted diets. Diets were designed to contain 30, 26, 22, and 18% of calories from fat; 300, 200, 100, and 100 mg cholesterol/day; and a polyunsaturated/saturated fat ratio of approximately 1.0. Triglyceride and low-density-lipoprotein cholesterol (LDL-C) cutpoints were based on the age-specific 75th percentile value. Over 18 months, 8372 men were screened, yielding 320 HC subjects randomized to the four diets and 211 CHL subjects randomized to the first three diets (because of fewer CHL subjects). At baseline, HC and CHL subjects were similar in age, education, lifestyle, dietary intake, and LDL-C, but CHL subjects were heavier, more hyperglycemic, hyperinsulinemic, and hypertensive.

CONCLUSIONS

Recruiting a large cohort of HC and CHL subjects from an industrial workforce is feasible in a restricted time frame. CHL subjects demonstrate features of the insulin resistance/hypertension syndrome, differing from HC subjects. CHL is sufficiently common relative to HC (2:3) to permit a comparison of dietary responses between the two conditions. Finally, the randomization of HC and CHL subjects to the diets yielded statistically indistinguishable groups, permitting a test of the efficacy of the alternative diets within each hyperlipidemic (HL) category.

The sole source: the Library of Congress National Library Service for the Blind and Physically Handicapped

The Library of Congress National Library Service for the Blind and Physically Handicapped leads a co-operative network of specialized libraries and ancillary agencies that are delivering a successful programme of reading and informational services to blind, visually impaired and handicapped users. Its unique position within the Library of Congress and the benefits which emanate from this relationship are described. This current review outlines and discusses the development, role and functioning of the National Library Service.

Estimating low-density lipoprotein cholesterol by the Friedewald equation is adequate for classifying patients on the basis of nationally recommended cutpoints

We compared low-density lipoprotein cholesterol (LDL) values obtained by the Friedewald formula--i.e., total cholesterol minus high-density lipoprotein (HDL) cholesterol minus very-low-density lipoprotein (VLDL) cholesterol (estimated as triglyceride divided by 5)--with those obtained by lipoprotein fractionation, using 4736 specimens. When triglycerides were less than 2.0 g/L, greater than 90% of estimated LDL cholesterol values were acceptable, within +/- 10% of measured values. At triglyceride concentrations of 2.0-4.0 g/L and 4.0-6.0 g/L, only 72% and 39%, respectively, of the estimates were acceptable. LDL values derived from an alternative formula, estimating VLDL as triglycerides divided by 6, were even less accurate. Nevertheless, the use of estimated LDL for risk classification based on the National Cholesterol Education Program Adult Treatment Panel cutpoints of 1.30 and 1.60 g/L was considered acceptable. At triglyceride concentrations less than or equal to 5.0 g/L, 88% of classifications based on estimated LDL (using triglycerides divided by 5) were concordant with those by measured LDL. Eleven percent of classifications were shifted across one cutpoint, evenly distributed between high and low. Fewer than 1% of classifications, all with Type III hyperlipoproteinemia, were misclassified two cutpoints high. Refinements in the estimation model did not substantially improve LDL estimation or concordance of risk classification.

Estimating low-density lipoprotein cholesterol by the Friedewald equation is adequate for classifying patients on the basis of nationally recommended cutpoints

We compared low-density lipoprotein cholesterol (LDL) values obtained by the Friedewald formula--i.e., total cholesterol minus high-density lipoprotein (HDL) cholesterol minus very-low-density lipoprotein (VLDL) cholesterol (estimated as triglyceride divided by 5)--with those obtained by lipoprotein fractionation, using 4736 specimens. When triglycerides were less than 2.0 g/L, greater than 90% of estimated LDL cholesterol values were acceptable, within +/- 10% of measured values. At triglyceride concentrations of 2.0-4.0 g/L and 4.0-6.0 g/L, only 72% and 39%, respectively, of the estimates were acceptable. LDL values derived from an alternative formula, estimating VLDL as triglycerides divided by 6, were even less accurate. Nevertheless, the use of estimated LDL for risk classification based on the National Cholesterol Education Program Adult Treatment Panel cutpoints of 1.30 and 1.60 g/L was considered acceptable. At triglyceride concentrations less than or equal to 5.0 g/L, 88% of classifications based on estimated LDL (using triglycerides divided by 5) were concordant with those by measured LDL. Eleven percent of classifications were shifted across one cutpoint, evenly distributed between high and low. Fewer than 1% of classifications, all with Type III hyperlipoproteinemia, were misclassified two cutpoints high. Refinements in the estimation model did not substantially improve LDL estimation or concordance of risk classification.

A follow-up study on alcoholics with and without co-existing affective disorder

Three-hundred male alcoholics were selected from consecutive admissions to hospital. They were divided into three diagnostic sub-groups: primary alcoholics; alcoholics with unipolar affective disorder; and alcoholics with bipolar affective disorder. After three follow-up interviews over a 2-year period after hospital discharge, the three sub-groups reported differences in frequency of mood change, amount of treatment received, and hospital attendance, although there were no clear-cut differences in items associated with their alcoholism. There were, however, some indications that bipolar patients functioned at a better level during the follow-up period, particularly those who were older, had a previous history of longer periods of abstinence, and maintained more frequent contact with Alcoholics Anonymous (AA) and their family doctor.

The effect of familiar size at familiar distances

The effect of familial size as a distance cue was tested with familiar objects at familiar distances. Experiment 1 showed that there were no uncontrolled distance cues available and that in their absence the retinal image did not affect depth or size perception. Under these conditions, size and distance judgments were essentially indeterminate and independent of each other. In experiment 2 a paradigm was employed which allowed a direct determination of whether equivalent changes either in size of a familiar object or in its true distance produced equivalent changes in its perceived distance. The results showed that there were no uncontrolled distance cues, and that subjects perceived the familiar object as having its familiar size. Moreover, changing the retinal image of the objects had almost exactly the same effect on their perceived distance as did changing their true distance. Hence, familial size does effectively govern the perception of distance when there are no competing cues.