Two-stage deep neural network for diagnosing fungal keratitis via in vivo confocal microscopy images.

Timely and effective diagnosis of fungal keratitis (FK) is necessary for suitable treatment and avoiding irreversible vision loss for patients. In vivo confocal microscopy (IVCM) has been widely adopted to guide the FK diagnosis. We present a deep learning framework for diagnosing fungal keratitis using IVCM images to assist ophthalmologists. Inspired by the real diagnostic process, our method employs a two-stage deep architecture for diagnostic predictions based on both image-level and sequence-level information. To the best of our knowledge, we collected the largest dataset with 96,632 IVCM images in total with expert labeling to train and evaluate our method. The specificity and sensitivity of our method in diagnosing FK on the unseen test set achieved 96.65% and 97.57%, comparable or better than experienced ophthalmologists. The network can provide image-level, sequence-level and patient-level diagnostic suggestions to physicians. The results show great promise for assisting ophthalmologists in FK diagnosis.

Expression and characterization of thymine-DNA glycosylase from Aeropyrum pernix.

The recombinant thymine-DNA glycosylase (TDG) from Aeropyrum pernix (A. pernix) was expressed in Escherichia coli. The enzymatic activity of recombinant A. pernix TDG (ApeTDG) was characterized using oligonucleotides containing a thymine/uracil base as substrate. ApeTDG had distinct glycosylase activity on T/G mismatch. The optimal temperature and pH for thymine removal were 65-70 degrees C and pH 7.0-8.5, respectively. High concentration of NaCl inhibited the thymine removal. Divalent ions had different influence on the thymine removal by ApeTDG. Ca(2+) and Mg(2+) had no inhibition on the enzymic activity, but Ni(2+), Co(2+), Cu(2+), Mn(2+), and Zn(2+) completely inhibited the excision reaction. As derived from a hyperthermophilic archaea, ApeTDG protein was heat-resistant at 75 degrees C. ApeTDG also had a relatively weak DNA glycosylase activity on uracil base, with the following order: U/C>U/G approximately U/T>U/U approximately U/I approximately U/AP approximately U/->U/A. Additional mismatch located at 3' of T/G had less inhibition on the thymine removal than that located at 5' of T/G, and two additional mismatches located at each side of T/G completely inhibited the excision of thymine. Together, these data suggest that ApeTDG is a TDG protein with weak UDG activity.

Avascular osteonecrosis after treatment of SARS: a 3-year longitudinal study.

OBJECTIVE: To investigate the relationship between avascular osteonecrosis (AVN) and corticosteroid treatment given to patients with severe acute respiratory syndrome (SARS). METHODS: Longitudinal study of 71 former SARS patients (mainly health care workers) who had been treated with corticosteroids, with an observation time of 36 months. Magnetic resonance images (MRI) and X-rays of hips, knees, shoulders, ankles and wrists were taken as part of the post-SARS follow-up assessments. RESULTS: Thirty-nine per cent developed AVN of the hips within 3-4 months after starting treatment. Two more cases of hip necrosis were seen after 1 year and another 11 cases of AVN were diagnosed after 3 years, one with hip necrosis and 10 with necrosis in other joints. In total, 58% of the cohort had developed AVN after 3 years of observation. The sole factor explaining AVN in the hip was the total dose of corticosteroids received. CONCLUSION: The use of corticosteroids in SARS has been debated; opinions conflict about whether the immediate benefits in terms of saving lives compensate for the adverse effects, including AVN.