Citations

AbstractMosaic chromosomal abnormalities are relatively common. However, mosaicism may be missed due to multiple factors including failure to recognize clinical indications and order appropriate testing, technical limitations of diagnostic assays, or sampling tissue (s) in which mosaicism is either not present, or present at very low levels. Blood leukocytes have long been the “gold standard” sample for cytogenetic analysis; however, the culturing process for routine chromosome analysis can complicate detection of mosaicism since the normal cell line may have a growth advantage in culture, or may not be present in the cells that produce metaphases (the lymphocytes). Buccal cells are becoming increasingly utilized for clinical analyses and are proving to have many advantages. Buccal swabs allow for simple and noninvasive DNA collection. When coupled with a chromosomal microarray that contains single nucleotide polymorphic probes, analysis of buccal cells can maximize a clinician's opportunity to detect cytogenetic mosaicism. We present three cases of improved diagnosis of mosaic aberrations using buccal specimens for chromosomal microarray analysis. In each case, the aberration was either undetectable in blood or present at such a low level it likely could have gone undetected. These cases highlight the limitations of certain laboratory methodologies for identifying mosaicism. We also present practice implications for genetic counselors, including clinic workflow changes and counseling approaches based on increasing use of buccal samples.

Recently, a FDA Safety Communication warned of a dose-dependent risk for QTc prolongation with citalopram, which is metabolized by CYP2C19 of the cytochrome P450 system. We investigate associations between citalopram and escitalopram dose, serum concentration, CYP2C19 phenotype, and QTc. We undertook a retrospective chart review of citalopram or escitalopram patients with the inclusion criteria of consistent medication dose, CYP2C19 phenotype (extensive metabolizers [EM], intermediate metabolizers [IM], poor metabolizers [PM]), and QTc interval on ECG. We further identified 42 citalopram users with citalopram serum concentration measurements and ECG. Regression and one-way ANOVA were used to examine the relationship between citalopram dose, citalopram serum concentration, CYP2C19 phenotype, and QTc interval. Of 75 citalopram patients, the EM group had significantly shorter QTc intervals than a combined IM+PM group (427.1±23.6 ms vs. 440.1±26.6 ms, one-tailed t-test, p=0.029). In the 80 escitalopram cohort, there was no significant difference in QTc between phenotype groups. There was no statistical correlation between citalopram ( p=0.62) or escitalopram ( p=0.30) dose and QTc. QTc was not associated with citalopram serum level ( p=0.45). In contrast to the FDA warning, this study found no association between citalopram/escitalopram dose and QTc. However, PM of the drug tended to have longer QTc intervals. Our findings suggest cytochrome P450 genotyping in select patients may be helpful to guide medication optimization while limiting harmful effects.

Background Constant flow and concentration CO2 has previously been efficacious in attenuating ventilatory oscillations in periodic breathing (PB) where oscillations in CO2 drive ventilatory oscillations. However, it has the undesirable effect of increasing end-tidal CO2, and ventilation. We tested, in a model of PB, a dynamic CO2 therapy that aims to attenuate pacemaker-induced ventilatory oscillations while minimising CO2 dose. Methods First, pacemakers were manipulated in 12 pacemaker recipients, 6 with heart failure (ejection fraction (EF)=23.7±7.3%) and 6 without heart failure, to experimentally induce PB. Second, we applied a real-time algorithm of pre-emptive dynamic exogenous CO2 administration, and tested different timings. Results We found that cardiac output alternation using pacemakers successfully induced PB. Dynamic CO2 therapy, when delivered coincident with hyperventilation, attenuated 57% of the experimentally induced oscillations in end-tidal CO2: SD/mean 0.06±0.01 untreated versus 0.04±0.01 with treatment (p<0.0001) and 0.02±0.01 in baseline non-modified breathing. This translated to a 56% reduction in induced ventilatory oscillations: SD/mean 0.19±0.09 untreated versus 0.14±0.06 with treatment (p=0.001) and 0.10±0.03 at baseline. Of note, end-tidal CO2 did not significantly rise when dynamic CO2 was applied to the model (4.84±0.47 vs 4.91± 0.45 kPa, p=0.08). Furthermore, mean ventilation was also not significantly increased by dynamic CO2 compared with untreated (7.8±1.2 vs 8.4±1.2 L/min, p=0.17). Conclusions Cardiac pacemaker manipulation can be used to induce PB experimentally. In this induced PB, delivering CO2 coincident with hyperventilation, ventilatory oscillations can be substantially attenuated without a significant increase in end-tidal CO2 or ventilation. Dynamic CO2 administration might be developed into a clinical treatment for PB. Trial Registration number ISRCTN29344450.

Background and Objectives: Online university students are a growing population whose health has received minimal attention. The purpose of this cross-sectional Internet survey was to identify risk factors for the health status among online university students. Methods: This online survey collected data from 301 online university students through a large, US-based participant pool and LinkedIn. Health status was measured using 3 elements of health-related quality of life (HRQOL): self-rated overall health (SRH), unhealthy days, and recent activity limitation days. All 3 measures were dichotomized. Results: The odds of poor SRH were higher for people who reported a body mass index in the overweight and obese categories (odds ratio [OR] = 2.99, P < .05) and for those who reported being smokers (OR = 2.52, P = .03). The odds of frequent unhealthy days were lower for those who made more than $35 000 compared with those who reported making less (OR = 0.50, P = .03) and those who exercised 4 or more times a week compared with those who exercised less (OR = 0.28, P < .05). The odds of frequent activity limitation were lower for those who reported an income of more than $35 000 (OR = 0.29, P = .04) and higher for persons who reported belonging to “other” race (OR = 14.75, P = .00). Conclusions: Universities might fruitfully target health promotion programs for online students who are low income, in disadvantaged racial groups, who are overweight, smoke, and who do not exercise.

Targeting a kinase common to both the EGFR and TNFα signaling pathways may prevent drug resistance in glioblastoma.

Guidelines for the treatment of pulmonary arterial hypertension (PAH) recommend sequential add‐on therapy for patients who deteriorate or fail to improve clinically. However, it is not known whether these patients also benefit from transitioning from inhaled prostacyclins to parenteral prostacyclins. We sought to characterize PAH patients receiving inhaled treprostinil who were transitioned to parenteral treprostinil. We conducted a multicenter retrospective study at 7 PAH centers and collected reasons, methods, safety, and outcome of patients transitioned from inhaled treprostinil to parenteral treprostinil. Twenty‐six patients with pulmonary hypertension in group 1, 4, or 5 transitioned from inhaled treprostinil to parenteral treprostinil (10 intravenous, 16 subcutaneous). Twenty‐four patients were also on one or two oral therapies. Reasons for transition were clinical deterioration, lack of clinical improvement, and pregnancy (19, 6, and 1 patients, respectively). Transitions occurred in hospital, clinic, or home (17, 7, and 2 patients, respectively). Parenteral infusion was started after the last inhaled treatment at maintenance dose (13 patients), after the inhaled therapy was downtitrated to 18 μg (6 patients), or with an overlap of inhaled downtitration with parenteral uptitration (7 patients). The transition was safe; side effects included symptoms of prostacyclin overdose. Patients were followed for 3–18 months. At 3 months, 8 patients improved, 17 maintained their functional class, and 1 continued to deteriorate. In conclusion, selected PAH patients can be safely transitioned from inhaled treprostinil to parenteral treprostinil using a variety of methodologies in different settings with the expectation that patients will improve or at least remain clinically stable.

Summary The presence of clonal circulating plasma cells (c PC s) remains a marker of high‐risk disease in newly diagnosed multiple myeloma (MM) patients. However, its prognostic utility in MM patients with previously treated disease is unknown. We studied 647 consecutive patients with previously treated MM seen at the Mayo Clinic, Rochester who had their peripheral blood evaluated for c PC s by multi‐parameter flow cytometry. Of these patients, 145 had actively relapsing disease while the remaining 502 had disease that was in a plateau and included 68 patients in complete remission (CR) and 434 patients with stable disease. Patients with actively relapsing disease were more likely to have clonal c PC s than those in a plateau ( P < 0·001). None of the patients in CR had any clonal c PC s detected. Among patients whose disease was in a plateau, the presence of clonal c PC s predicted for a worse median survival (22 months vs. not reached; P = 0·004). Among actively relapsing patients, the presence of ≥100 c PC s predicted for a worse survival after flow cytometry analysis (12 months vs. 33 months; P < 0·001). Future studies are needed to determine the role of these findings in developing a risk‐adapted treatment approach in MM patients with actively relapsing disease.