A phase I and pharmacokinetic study of intraperitoneal topotecan

Purpose: To evaluate the feasibility and pharmacology of intraperitoneal (IP) topotecan. Patients and methods: Fifteen patients with recurrent ovarian cancer in a phase I trial were treated with escalating IP topotecan doses (5–30 mg/m2) for pharmacokinetic analysis. Results: Dose limiting toxicity (DLT) was acute hypotension, chills and fever at the 30 mg/m2 dose level. Haematological toxicity and abdominal pain were mild for all dose levels studied. Pharmacokinetics: Peak plasma levels of total topotecan were reached at 2.7 ± 1.1 h after IP instillation. The apparent V ss was 69.9 ± 25.4 L/m2, plasma clearance 13.4 ± 2.5 L/h/m2 and plasma T1/2 3.7 ± 1.3 h. The plasma AUC was correlated with the dose (R = 0.95, P < 0.01). The plasma AUC ratio of lactone versus total topotecan (lactone + carboxy-forms) increased with the dose from 16% to 55%, (R = 0.84, P < 0.01). Peritoneal total topotecan was cleared from the peritoneal cavity at 0.4 ± 0.3 L/h.m2 with a T1/2 = 2.7 ± 1.7 h. The mean peritoneal/plasma AUC ratio for total topotecan was 54 ± 34. Conclusion: A substantial dose of topotecan can be delivered by the IP route, achieving cytotoxic plasma levels of topotecan, with acceptable toxicity. The recommended dose for further phase II trials is 20 mg/m2 IP, which enables combination with active doses of other cytotoxic drugs, in view of its limited myelotoxicity when given by this route. © 2001 Cancer Research Campaign http://www.bjcancer.co

Suspected Lynch syndrome associated MSH6 variants: A functional assay to determine their pathogenicity

Lynch syndrome (LS) is a hereditary cancer predisposition caused by inactivating mutations in DNA mismatch repair (MMR) genes. Mutations in the MSH6 DNA MMR gene account for approximately 18% of LS cases. Many LS-associated sequence variants are nonsense and frameshift mutations that clearly abrogate MMR activity. However, missense mutations whose functional implications are unclear are also frequently seen in suspected-LS patients. To conclusively diagnose LS and enroll patients in appropriate surveillance programs to reduce morbidity as well as mortality, the functional consequences of these variants of uncertain clinical significance (VUS) must be defined. We present an oligonucleotide-directed mutagenesis screen for the identification of pathogenic MSH6 VUS. In the screen, the MSH6 variant of interest is introduced into mouse embryonic stem cells by site-directed mutagenesis. Subsequent selection for MMR-deficient cells using the DNA damaging agent 6-thioguanine (6TG) allows the identification of MMR abrogating VUS because solely MMR-deficient cells survive 6TG exposure. We demonstrate the efficacy of the genetic screen, investigate the phenotype of 26 MSH6 VUS and compare our screening results to clinical data from suspected-LS patients carrying these variant alleles

Evaluating Comprehensibility of 157 Patient-Reported Outcome Measures (PROMs) in the Nationwide Dutch Outcome-Based Healthcare Program:More Attention for Comprehensibility of PROMs is Needed

IntroductionPatient-reported outcomes measures (PROMs) are increasingly prevalent in healthcare and used for shared decision-making and healthcare quality evaluation. However, the extent to which patients with varying health literacy levels can complete PROMs is often overlooked. This may lead to biased aggregated data and patients being excluded from studies or other PROM collection initiatives. This cross-sectional study evaluates the comprehensibility of 157 well-known and widely used PROM scales using a comprehensibility checklist.MethodsPairs of two independent raters scored 157 PROM scales designed for adults included in the 35 sets of outcome information developed as part of the Dutch Outcome-Based Healthcare Program. The PROM scales were scored on the eight comprehensibility domains of the Pharos Checklist for Questionnaires in Healthcare (PCQH). Interrater agreement of domain ratings was assessed using Intraclass Correlation Coefficients or Cohen's kappa. Subsequently, final ratings were established through discussion and used to evaluate the domain-specific comprehensibility rating for each PROM scale.ResultsComprehensibility of a large number of PROM scales (n = 157), which cover a wide range of diseases and conditions across Dutch medical specialist care, was assessed. While most PROM scales were written at an accessible language level, with minimal use of medical terms, instruction clarity, number of questions, and response options emerged as significant issues, affecting a substantial proportion of PROM scales. Interrater agreement was high for most domains of the PCQH.ConclusionThis study highlights the need for greater attention to the comprehensibility of PROMs to ensure their accessibility to all patients, including those with low health literacy. The PCQH can be a valuable tool in PROM development in addition to qualitative methods and in selection processes enabling comparison of comprehensibility between PROMs. However, the PCQH needs further development and validation for these purposes. Enhancing the comprehensibility of PROMs is essential for their effective incorporation in healthcare evaluation and decision-making processes

Shared Decision Making in Health Care Visits for CKD:Patients’ Decisional Role Preferences and Experiences

Rationale &amp; Objective: Research on shared decision making (SDM) in chronic kidney disease (CKD) has focused almost exclusively on the modality of kidney replacement treatment. We explored what other CKD decisions are recognized by patients, what their preferences and experiences are regarding these decisions, and how decisions are made during their interactions with medical care professionals. Study Design: Cross-sectional study. Setting &amp; Participants: Patients with CKD receiving (outpatient) care in 1 of 2 Dutch hospitals. Exposure: Patients’ preferred decisional roles for treatment decisions were measured using the Control Preferences Scale survey administered after a health care visit with medical professionals. Outcome: Number of decisions for which patients experienced a decisional role that did or did not match their preferred role. Observed levels of SDM and motivational interviewing in audio recordings of health care visits, measured using the 4-step SDM instrument (4SDM) and Motivational Interviewing Treatment Integrity coding tools.Analytical Approach: The results were characterized using descriptive statistics, including differences in scores between the patients’ experienced and preferred decisional roles. Results: According to the survey (n = 122) patients with CKD frequently reported decisions regarding planning (112 of 122), medication changes (82 of 122), or lifestyle changes (59 of 122). Of the 357 reported decisions in total, patients preferred that clinicians mostly (125 of 357) or fully (101 of 357) make the decisions. For 116 decisions, they preferred a shared decisional role. For 151 of 357 decisions, the patients’ preferences did not match their experiences. Decisions were experienced as “less shared/patient-directed” (76 of 357) or “more shared/patient-directed” (75 of 357) than preferred. Observed SDM in 118 coded decisions was low (median 4; range, 0 – 22). Motivational interviewing techniques were rarely used. Limitations: Potential recall and selection bias, and limited generalizability. Conclusions: We identified multiple discrepancies between preferred, experienced, and observed SDM in health care visits for CKD. Although patients varied in their preferred decisional role, a large minority of patients expressed a preference for shared decision making for many decisions. However, SDM behavior during the health care visits was observed infrequently. Plain-Language Summary: Shared decision making (SDM) may be a valuable approach for common chronic kidney disease (CKD) decisions, but our knowledge is limited. We collected patient surveys after health care visits for CKD. Patients most frequently experienced decisions regarding planning, medication, and lifestyle. Three decisional roles were preferred by comparable numbers of patients: let the clinician alone decide, let the clinician decide for the most part, or “equally share” the decision. Patients’ experiences of who made the decision did not always match their preferences. In audio recordings of the health care visits, we observed low levels of SDM behavior. These findings suggest that the preference for “sharing decisions” is often unmet for a large number of patients.</p

<i>C-elegans</i> model identifies genetic modifiers of alpha-synuclein inclusion formation during aging

Inclusions in the brain containing alpha-synuclein are the pathological hallmark of Parkinson's disease, but how these inclusions are formed and how this links to disease is poorly understood. We have developed a &lt;i&gt;C-elegans&lt;/i&gt; model that makes it possible to monitor, in living animals, the formation of alpha-synuclein inclusions. In worms of old age, inclusions contain aggregated alpha-synuclein, resembling a critical pathological feature. We used genome-wide RNA interference to identify processes involved in inclusion formation, and identified 80 genes that, when knocked down, resulted in a premature increase in the number of inclusions. Quality control and vesicle-trafficking genes expressed in the ER/Golgi complex and vesicular compartments were overrepresented, indicating a specific role for these processes in alpha-synuclein inclusion formation. Suppressors include aging-associated genes, such as sir-2.1/SIRT1 and lagr-1/LASS2. Altogether, our data suggest a link between alpha-synuclein inclusion formation and cellular aging, likely through an endomembrane-related mechanism. The processes and genes identified here present a framework for further study of the disease mechanism and provide candidate susceptibility genes and drug targets for Parkinson's disease and other alpha-synuclein related disorders

Mechanical Ventilation and the Titer of Antibodies as Risk Factors for the Development of Transfusion-Related Lung Injury

Purpose. Onset of transfusion-related acute lung injury (TRALI) is suggested to be a threshold-event. Data is lacking on the relation between titer of antibodies infused and onset of TRALI. We determined whether onset of TRALI is dependent on the titer of MHC-I antibodies infused in a combined model of ventilator-induced lung injury and antibody-induced TRALl. Methods. BALB/c mice were ventilated for five hours with low (7.5 ml/kg) or high (15 ml/kg) tidal volume. After three hours of MV, TRALI was induced by infusion of 0.5 mg/kg, 2.0 mg/kg or 4.5 mg/kg MHC-I antibodies. Control animals received vehicle. After five hours of MV, animals were sacrificed. Results. MV with high tidal volumes resulted in increased levels of all markers of lung injury compared to animals ventilated with low tidal MV. In ventilator-induced lung injury, infusion of 4.5 mg/kg of antibodies further increased pulmonary wet-to-dry ratio, pulmonary neutrophil influx and pulmonary KC levels, whereas infusion of lower dose of antibodies did not augment lung injury. In contrast, mice ventilated with low tidal volumes did not develop lung injury, irrespective of the dose of antibody used. Conclusions. In the presence of injurious MV, onset of TRALI depends on the titer of antibodies infused

A biological question and a balanced (orthogonal) design: the ingredients to efficiently analyze two-color microarrays with Confirmatory Factor Analysis

BACKGROUND: Factor analysis (FA) has been widely applied in microarray studies as a data-reduction-tool without any a-priori assumption regarding associations between observed data and latent structure (Exploratory Factor Analysis). A disadvantage is that the representation of data in a reduced set of dimensions can be difficult to interpret, as biological contrasts do not necessarily coincide with single dimensions. However, FA can also be applied as an instrument to confirm what is expected on the basis of pre-established hypotheses (Confirmatory Factor Analysis, CFA). We show that with a hypothesis incorporated in a balanced (orthogonal) design, including 'SelfSelf' hybridizations, dye swaps and independent replications, FA can be used to identify the latent factors underlying the correlation structure among the observed two-color microarray data. An orthogonal design will reflect the principal components associated with each experimental factor. We applied CFA to a microarray study performed to investigate cisplatin resistance in four ovarian cancer cell lines, which only differ in their degree of cisplatin resistance. RESULTS: Two latent factors, coinciding with principal components, representing the differences in cisplatin resistance between the four ovarian cancer cell lines were easily identified. From these two factors 315 genes associated with cisplatin resistance were selected, 199 genes from the first factor (False Discovery Rate (FDR): 19%) and 152 (FDR: 24%) from the second factor, while both gene sets shared 36. The differential expression of 16 genes was validated with reverse transcription-polymerase chain reaction. CONCLUSION: Our results show that FA is an efficient method to analyze two-color microarray data provided that there is a pre-defined hypothesis reflected in an orthogonal design