Diagnosis of thymoma by needle biopsy.

One cutting needle biopsy specimen and six fine needle aspiration biopsy specimens of thymomas were studied in order to define diagnostic criteria for this entity in biopsy material. Two of the cases demonstrated a mixed pattern of epithelial cells and lymphocytes while epithelial cells predominated in four cases and lymphocytes in one. Tumors composed of a conspicuous admixture of benign-appearing epithelial cells and mature lymphocytes were easily diagnosed. Neoplasms composed primarily of one cell type also displayed distinctive cytologic features that correlated with the histopathologic appearance of the resected tumors and permitted a diagnosis. Immunocytochemical demonstration of keratin and T6 proved useful in confirming the biphasic pattern of epithelial cells and cortical thymocytes that is characteristic of thymoma.     

Functional Status Predicts Acute Care Readmissions from Inpatient Rehabilitation in the Stroke Population

Objective

Acute care readmission risk is an increasingly recognized problem that has garnered significant attention, yet the reasons for acute care readmission in the inpatient rehabilitation population are complex and likely multifactorial. Information on both medical comorbidities and functional status is routinely collected for stroke patients participating in inpatient rehabilitation. We sought to determine whether functional status is a more robust predictor of acute care readmissions in the inpatient rehabilitation stroke population compared with medical comorbidities using a large, administrative data set.

Methods

A retrospective analysis of data from the Uniform Data System for Medical Rehabilitation from the years 2002 to 2011 was performed examining stroke patients admitted to inpatient rehabilitation facilities. A Basic Model for predicting acute care readmission risk based on age and functional status was compared with models incorporating functional status and medical comorbidities (Basic-Plus) or models including age and medical comorbidities alone (Age-Comorbidity). C-statistics were compared to evaluate model performance.

Findings

There were a total of 803,124 patients: 88,187 (11%) patients were transferred back to an acute hospital: 22,247 (2.8%) within 3 days, 43,481 (5.4%) within 7 days, and 85,431 (10.6%) within 30 days. The C-statistics for the Basic Model were 0.701, 0.672, and 0.682 at days 3, 7, and 30 respectively. As compared to the Basic Model, the best-performing Basic-Plus model was the Basic+Elixhauser model with C-statistics differences of +0.011, +0.011, and + 0.012, and the best-performing Age-Comorbidity model was the Age+Elixhauser model with C-statistic differences of -0.124, -0.098, and -0.098 at days 3, 7, and 30 respectively.

Conclusions

Readmission models for the inpatient rehabilitation stroke population based on functional status and age showed better predictive ability than models based on medical comorbidities.     

Role of interflash intervals in a firefly courtship (Photinus macdermotti)

The flash code of Photinus macdermotti fireflies has been measured over a temperature range of 16 to 25°C. The code changes in characteristics fashion during different phases of firefly courtship. Males produce rhythmic patrolling flashes while flying, and when answered, shift to courtship flash pairs of significantly shorter interval. Females will answer some consecutive patrolling flashes and normally respond after the second flash of each male courtship pair. A possible behavioural role for the shifting of male patrolling and courtship flash intervals and for the female's response patterns is proposed.