BACKGROUND: Microbial screening is required for all cord blood units (CBUs). Four gram-positive contaminants were documented to survive cryopreservation poorly and isolation of other contaminants were reported.
METHODS: Forty-eight contaminated CBUs detected with either Staphylococcus epidermidis, Corynebacterium species, Peptostreptococcus or Streptococcus species before cryopreservation were used in this study. CBUs were processed, DMSO-infused and microbial screened before cryopreservation. Post-thaw microbial screening was achieved using 1 and 10 ml inoculants in BACTEC culture bottles. Positive bottles were subjected for microbial identification and results were compared with those from pre-freeze.
RESULTS: A higher rate of microbial contamination was found using the 10 ml inoculant. Screening of 11 CBUs did not detect any contaminants while 30 CBUs screened detected more than one unknown contaminants and majority of contaminants were identified to be gram-negative species.
CONCLUSION: A higher inoculation volume used at post-thaw for microbial screening improves contamination detection but leads to the loss of precious cord blood. Some contaminants did not survive cryopreservation or were not identified due to their low microbial levels. Contrasting contaminants found at post-thaw suggest the improvements made in detection and identification of contaminants over the years.
MATERIALS AND METHODS: This was a cross sectional study with 64 arms from 32 patients (34 neuropathic, 30 nonneuropathic). Diagnosis was confirmed by nerve conduction study and electromyography. The ulnar nerves were evaluated with 15MHz small footprint linear array transducer. The ulnar nerve CSA was measured at three levels with arm extended: at medial epicondyle (ME), 5cm proximal and 5cm distal to ME. Results from the neuropathic and nonneuropathic arms were compared. Independent T-tests and Pearson correlation tests were used. P value of less than 0.05 was considered significant.
RESULTS: Mean CSA values for the UN at levels 5cm proximal to ME, ME and 5cm distal to ME were 0.055, 0.109, 0.045 cm(2) respectively in the neuropathic group and 0.049, 0.075, 0.042 cm2 respectively in the non-neuropathic group. The CSA of the UN at the ME level was significantly larger in the neuropathic group, with p value of 0.005. However, there was no statistical difference between the groups at 5cm proximal and distal to the ME, with p values of 0.10 and 0.35 respectively.
CONCLUSION: There is significant difference in CSA values of the UN at ME between the neuropathic and non-neuropathic groups with mean CSA value above the predetermined 0.10cm(2) cut-off point. High-resolution ultrasonography is therefore useful to diagnose and follow up cases of elbow UNN.