During a study of fascicle abscission in Pinus taeda L., tyloses were observed to occlude tracheids of both proximal and distal abscission scars. The tyloses represent the protrusion of ray parenchyma cells into tracheid lumens. Multiple tyloses often arise from a given parenchyma cell and can enter multiple tracheids. Tyloses occur as part of an abscission process that also includes the presence of Type II cells (programmed to enlarge during abscission in the presence of ethylene) and rupture of tracheids-features common to abscission in angiosperms.

Cardiovascular disease is a common comorbidity associated with an aging population. However, there is a unique group of individuals whose age-defying qualities are still being investigated. This retrospective chart review analyzed various cardiac and metabolic health parameters to characterize the prevalence of heart failure and metabolic derangements in individuals aged 90 years old or older in central Arkansas. Only 236 of the 291 patients in our study cohort had blood pressures recorded. Of these, 50% had systolic blood pressures ≥140 mmHg. Additionally, 77% had pulse pressures ≥50 mmHg. Of the 96 patients with BNP data, 44% had values ≥300 pg/mL. There was a slight positive correlation between aging and HDL cholesterol, while there was a negative correlation between aging and both total cholesterol and LDL cholesterol. A majority of our patients had both elevated systolic blood pressures and elevated pulse pressures. A majority also had high BNP values, indicative of some degree of heart failure. Additionally, atrial fibrillation was a common arrhythmia identified on EKG. However, these oldest of the old patients had fewer documented metabolic derangements. These findings lay important groundwork for further investigation into lifestyle and genetic components that allow them to live exceptionally long with such comorbidities.

Digiovanni-Kinsley et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Heart failure and dementia are common age-related conditions. Heart failure and associated comorbidities of hypertension and arrhythmias may impact cognition. Retrospective data of 311 patients averaging 98 (±3.2) years who received treatment at the University of Arkansas for Medical Sciences were analyzed for diagnoses, prescribed medications and health conditions relevant to heart failure, hypertension, arrhythmias and dementia. 74% of the subjects were white, non-Hispanic, 24% were African American, and 2% were of unknown ethnicity. 83% were women and 17% were men. Only 251 (81%) of the reviewed charts had blood pressures recorded, of whom 43% (n=114) had systolic pressures >140mmHg. Furthermore, 50% (n=156) of patients had heart failure, and 29% (n=89) had dementia. Of those with dementia, 35% had an arrhythmia. For those without a diagnosis of dementia or any treatment for dementia, 25% had an arrhythmia. Heart failure and arrhythmias have not been well studied as an etiological factor for dementias. In our cohort, the presence of heart failure diagnoses was not different in those with dementia versus those without dementia. However, more patients with dementia had arrhythmias versus those without dementia, suggesting that arrhythmias may contribute to cognitive decline, even in the oldest old. Approximately 70% of the arrhythmias were atrial fibrillation. We did not have data on the management of these arrhythmias and whether anticoagulants were being used appropriately, especially for atrial fibrillation. Nevertheless this highlights the importance of close management of arrhythmias for maintaining cognitive health in older adults.