Biomedical subjects

K Low

Publications and source records attributed to K Low.

3 recordsLinked to original sources

PubMed1987

Infant hearing screening: program implementation and validation.

Congenital and early-onset hearing losses were discovered in 6.1% of 975 Intensive Care Nursery (ICN) graduates. The methods used were neonatal screening by Crib-O-Gram (COG) and high risk register, in combination with repeated behavioral hearing tests at 1 to 3 years. This 7-year longitudinal study had follow-up hearing evaluations for a remarkably high 84% of all subjects. Significant losses that interfered with speech and language development (1000 to 8000 Hz average loss greater than 45 dB HL bilaterally) were found in 4.3% of infants. COG in combination with subsequent behavioral hearing screening was a sensitive strategy for detecting significant hearing loss: only one child was missed with this combination. Alone, COG sensitivity to significant hearing losses was 79.3%, but would have been higher had a stricter passing criterion been adopted. Behavioral hearing screenings detected bilateral hearing losses of even mild (greater than 20 dB HL) degree. Sensitivity to significant hearing losses was 82.6% and would have been improved if test frequencies greater than 3000 Hz were included in the screen. Even if screening failure occurred at 1 year of age, the age of actual confirmation of hearing loss depended on severity of the loss and ear involvement. Significant hearing losses were confirmed earlier than less severe or unilateral losses. Although behavioral screenings could be done during the first year of life, continued follow-up was required to detect progressive hearing losses.

Acoustic Stimulation↗

PubMed1985

Growth kinetics of hybridoma cells: (1) The effects of varying foetal calf serum levels.

The growth kinetics, i.e. growth rate, cell yield and antibody production, of two murine hybridoma cell lines have been studied in several commercial media at different FCS levels in static 25 cm2 flask cultures. Reduction of FCS levels from 10% to 5% did not affect significantly the antibody yield whereas at 2% and 1% FCS levels growth rate, cell and antibody yield were reduced significantly in all media. Considerable differences were noted in the maximum cell populations obtained in the different media, with IMDM producing the highest cell and antibody yields; IMDM greater than HiGem greater than DME greater than RPMI. The cell lines did not grow in the absence of FCS but did grow in the presence of basal medium supplemented with insulin and transferrin at 10 mg per L. Both cell lines were stable during several months' passage in this medium. A supplement containing human albumin or BSA at 1 g per L combined with the insulin and transferrin (10 mg per L) could replace 1% FCS in DME without significantly affecting the cell yields of B6.

Animals↗

PubMed1985

Growth kinetics of hybridoma cells: (2) The effects of varying energy source concentrations.

Commercial media used for the growth of hybridoma cells contain different glucose concentrations. We have attempted to establish the optimal levels of glucose required for maximum hybridoma cell yields by studying the energy source metabolism of two murine hybridoma cell lines in several commercial media in static 25 cm2 flask cultures. The glucose and lactate quotients and growth yields from glucose of the two cell lines were similar in all media. Glucose limited growth in DME containing lg/L. Glucose supplementation to 2g/L in DME significantly increased cell and antibody yields. When fructose was used as a substitute for glucose the fructose quotient of one cell line was found to be similar to its glucose quotient whereas that of the other cell line was significantly reduced compared to its glucose quotient.

Animals↗