Smoking impairs molecular response, and reduces overall survival in patients with chronic myeloproliferative neoplasms: A retrospective cohort study.

The effects of smoking on the molecular response (MR) and overall survival (OS) in patients with chronic myeloproliferative neoplasms (MPNs) have not been investigated before. We analysed a historical cohort of 498 consecutive patients diagnosed with MPNs. Moreover, we analysed a subgroup of 270 consecutive patients with MPNs with > 1 measurement of the JAK2V617F variant allele frequency. The data were analysed using Kaplan-Meier plots and Cox regression analysis, along with linear regression models. In all patients, the rate of MR was significantly higher in never-smokers compared with current smokers in the univariate model (HR, 1·9; 95% CI, 1·1-3·3; P = 0·033) and the multivariate model (HR, 1·9; 95% CI, 1·1-3·5; P = 0·029). Similar findings were observed with different cut-off values for a partial MR. A subgroup analysis including only interferon-α2-treated patients showed similar results. In multivariate analyses, the OS was significantly better for never-smokers (HR, 0·46; 95% CI, 0·29-0·75; P = 0·002) than current smokers. The differences were more pronounced in the pegylated interferon-α2-treated patients. However, no significant interaction of interferon-α2 treatment was observed. In conclusion, we found that tobacco smoking reduced the rate of MR and OS in patients with MPNs. Cessation of smoking should be encouraged.

Nucleotide Composition of Human Ig Nontemplated Regions Depends on Trimming of the Flanking Gene Segments, and Terminal Deoxynucleotidyl Transferase Favors Adding Cytosine, Not Guanosine, in Most VDJ Rearrangements.

The formation of nontemplated (N) regions during Ig gene rearrangement is a major contributor to Ab diversity. To gain insights into the mechanisms behind this, we studied the nucleotide composition of N regions within 29,962 unique human VHDJH rearrangements and 8728 unique human DJH rearrangements containing exactly one identifiable D gene segment and thus two N regions, N1 and N2. We found a distinct decreasing content of cytosine (C) and increasing content of guanine (G) across each N region, suggesting that N regions are typically generated by concatenation of two 3' overhangs synthesized by addition of nucleoside triphosphates with a preference for dCTP. This challenges the general assumption that the terminal deoxynucleotidyl transferase favors dGTP in vivo. Furthermore, we found that the G and C gradients depended strongly on whether the germline gene segments were trimmed or not. Our data show that C-enriched N addition preferentially happens at trimmed 3' ends of VH, D, and JH gene segments, indicating a dependency of the transferase mechanism upon the nuclease mechanism.

Chronic appendicitis: two case reports.

BACKGROUND: Chronic appendicitis is a condition unfamiliar to many physicians and is often referred to as a controversial diagnosis. This can give rise to diagnostic delay. CASE PRESENTATION: We present two cases of chronic appendicitis: a Caucasian female aged 21 years and a Caucasian male aged 34 years. The patients had different clinical presentations, which led the initial investigations in very different directions-tropical infectious disease and possible malignancy, respectively. In both cases, radiological imaging was the key investigation leading to the final surprising diagnosis. CONCLUSION: With these two case stories, we wish to draw attention to chronic appendicitis as a possible differential diagnosis in younger patients with chronic or recurrent abdominal pain, particularly if the pain is located in the lower abdomen and is accompanied by fever.

High mortality among patients with severe COVID-19 and Do Not Intubate orders.

INTRODUCTION: Moderate to severe respiratory distress among patients with COVID-19 is associated with a high mortality. This study evaluated ventilator support and mortality by Do Intubate (DI) or Do Not Intubate (DNI) orders. METHODS: This was a retrospective study of patients with COVID-19 and a supplemental oxygen requirement of ≥ 15 l/min. The patients were divided into two groups corresponding to the first and second wave of COVID-19 and were subsequently further divided according to DI and DNI orders and analysed regarding need of ventilator support and mortality. RESULTS: The study included 178 patients. The mortality was 24% for patients with DI orders (n = 115) and 81% for patients with DNI orders (n = 63) increasing to 98% (n = 46) for patients with DNI orders and very high flow oxygen requirements (≥ 30 l/min.). From the first to the second wave of COVID-19, the use of constant continuous positive airway pressure (cCPAP) increased from 71% to 91% (p less-than 0.001), whereas the use of mechanical ventilation decreased from 54% to 28% (odds ratio = 0.38 (95% confidence interval: 0.17-0.85)). CONCLUSION: The mortality was high for patients with DNI orders and respiratory distress with very high levels in supplemental oxygen in both the first and second wave of COVID-19 despite an increase in use of cCPAP and treatment with dexamethasone and remdesivir during the second wave. Hence, careful evaluation on transition to palliative care must be considered for these patients. FUNDING: none. TRIAL REGISTRATION: The study was approved by the Danish Patient Safety Authority (record no. 31-1521-309) and the Regional Data Protection Centre (record no. P-2020-492).