Biomedical subjects

M K Money

Publications and source records attributed to M K Money.

8 recordsLinked to original sources

PubMed1996

Phenotypic patterns of distortion product otoacoustic emission in inbred and F1 hybrid hearing mouse strains.

Distortion product otoacoustic emissions (DPOE) were obtained from five different hearing mouse groups: CBA/J, MOLF/Rk, ct (homozygous normal mice of the curly-tail stock), and the F1 hybrid offspring of the matings CBA/J x dn/dn and MOLF/Rk x dn/dn (dn/dn mice are the curly-tail stock with recessive deafness). The DPOE patterns of the CBA/J and ct strains were similar to each other and different from that of the MOLF/Rk. The two sets of F1 hybrid mice, (CBA/J x dn/dn)F1 and (MOLF/Rk x dn/dn)F1, were found to have significantly larger DPOE amplitudes than their hearing parent strains, MOLF/Rk and CBA/J, respectively. In addition, the DPOE amplitudes were greater for the offspring of the MOLF/Rk x dn/dn cross than for those of the CBA/J x dn/dn cross, even though they were lower for MOLF/Rk than for CBA/J. The distinct features of DPOE patterns among these five groups suggest that DPOE testing can be used for auditory phenotyping.

Animals↗

PubMed1995

Auditory brainstem responses of CBA/J mice with neonatal conductive hearing losses and treatment with GM1 ganglioside.

Exogenous administration of GM1 ganglioside to CBA/J mice with a neonatal conductive hearing loss ameliorates the atrophy of spiral ganglion neurons, ventral cochlear nucleus neurons, and ventral cochlear nucleus volume. The present investigation demonstrates the extent of a conductive loss caused by atresia and tests the hypothesis that GM1 ganglioside treatment will ameliorate the conductive hearing loss. Auditory brainstem responses were recorded from four groups of seven mice each: two groups received daily subcutaneous injections of saline (one group had normal hearing; the other had a conductive hearing loss); the other two groups received daily subcutaneous injections of GM1 ganglioside (one group had normal hearing; the other had a conductive hearing loss). In mice with a conductive loss, decreases in hearing sensitivity were greatest at high frequencies. The decreases were determined by comparing mean ABR thresholds of the conductive loss mice with those of normal hearing mice. The conductive hearing loss induced in the mice in this study was similar to that seen in humans with congenital aural atresias. GM1 ganglioside treatment had no significant effect on ABR wave I thresholds or latencies in either group.

Acoustic Stimulation↗

PubMed1995

Auditory phenotyping of heterozygous sound-responsive (+/dn) and deafness (dn/dn) mice.

Accurate phenotyping of offspring from backcross matings between F1 heterozygous sound-responsive and deafness mice is an important step for the identification of the deafness (dn) gene (Keats et al., 1995). Here, we report the results of auditory phenotyping of backcross offspring who are either sound-responsive or deaf by recording the Preyer reflex elicited by hand clap, auditory brainstem responses (ABRs), and 2f1-f2 distortion product otoacoustic emissions (DPOEs). Our results show that the Preyer reflex observation alone is inadequate for auditory phenotyping; a more precise test such as a click-evoked ABR recording is needed for auditory phenotyping. DPOE recording results in identification of sound-responsive or deaf mice as accurately as the click-evoked ABR testing. In addition, because the DPOE amplitude function is in good agreement with the ABR threshold in frequency sensitivity and specificity for stimulus frequencies between 1 and 16 kHz, the DPOE recording can be considered as an alternate test for auditory phenotyping.

Acoustic Stimulation↗

PubMed1993

Mice heterozygous for the deafness gene have normal auditory thresholds.

Cochlear degeneration in the early postnatal period has been reported as a homozygous recessive mutation in deafness (dn/dn) mice of the curly-tail stock. Heterozygous (+/dn) mice of the same population exhibit hearing when tested by the Preyer reflex, and their cochlear morphology appears normal by light microscopy. However, whether the heterozygote's unmatched recessive deafness allele has deleterious effects not detected by this reflex has not been examined. This study compares the ABR thresholds of presumed homozygous dominant (+/+) and known heterozygous (+/dn) deafness mice, as well as CBA/J mice. Hearing thresholds in the heterozygotes were not significantly different from those of presumed homozygotes or CBA/J mice. A 'generational backtracking' method was used to increase the probability of identifying homozygous (+/+) animals of the curly-tail strain.

Alleles↗

PubMed1990

Relative strength of a new suture technique for fascial closure.

In an attempt to decrease the risk of fascial dehiscence, a new suture technique for fascial closure is proposed, referred to as the "secured" stitch. The secured interrupted stitch is performed by taking a double bite of fascia at each traditional site of fascial puncture. Relative strength of the secured interrupted stitch in comparison with the simple interrupted stitch is determined in samples of fresh bovine fascia. A significantly greater force is required to disrupt fascia repaired with the secured stitch compared with a simple interrupted repair. The secured stitch may afford a greater degree of protection from fascial dehiscence.

Animals↗

PubMed1990

Lower extremity amputation: open versus closed.

Wound breakdown was assessed in 117 amputations for nonhealing lesions and peripheral vascular closure (chi 2 10.34). Nonhealing occurred in 10/63 amputations with primary skin closure when compared with those not closed (p less than .01). All 54 amputation sites treated by the open technique healed without revision. Of 22 toe amputations, the open technique performed in 14 patients required a mean of nine postoperative days; the closed-toe amputation technique performed in 8 patients needed a mean of 5.8 days; the closed-toe amputation requiring revision needed a mean of 36.3 days. Healing rates were significantly different when the wound was left open versus primarily closed (chi 2 8.56 p less than .01). Nineteen transmetatarsal amputations (TMA) were completed; 10 open TMAs required a mean of twenty-four days; 9 closed TMAs required a mean of fifteen days; and revision a mean of eighteen days. Of 51 below-the-knee amputations (BKA), 20 open BKAs required a mean of thirteen days; 3 closed BKAs required a mean of 18.5 days; and 1 revision required two hundred fifty-eight days postoperatively. Twenty-five above-the-knee amputations (AKA) were performed; the 10 open AKAs required a mean of sixteen days; the 15 closed AKAs required a mean of eleven days. There was no significant difference in healing rates of TMA, BKA, or AKA. Healing rates of toe amputations and amputation overall are, however, significantly different. Closed lower extremity amputation wounds require fewer hospital days than open, except if problems in wound healing require revision.

Adult↗

PubMed1989

Transtracheal needle catheter ventilation in complete airway obstruction: an animal model.

Transtracheal needle catheter ventilation (TNCV) may be used as an alternative airway when contraindications to endotracheal intubation exist. A feline model tested the efficacy of low-flow oxygen delivery, and initial data were gathered to define proper catheter calibers to effect adequate oxygenation and ventilation. Cats were anesthetized, trachea intubated, and ventilated for 30 minutes with a pressure-regulated ventilator. Arterial and venous pressures were monitored, and a chest tube was inserted to measure intrathoracic pressures. Arterial blood gas analysis was performed every five minutes during the baseline period. The endotracheal tube was then removed, the trachea cross-clamped, and TNCV instituted. Oxygen flow rates of 1, 3, and 5 L/min were varied with catheter sizes of 14, 16, and 18 g. Data demonstrated that TNCV provided adequate oxygenation and ventilation with flow rates of 3 and 5 L/min with the 14- and 16-g catheters. Satisfactory oxygenation could be obtained with these flow rates with the 18-g catheter, but ventilation was inadequate. Ventilation was unsatisfactory with the 1 L/min flow rate in all catheter sizes. These preliminary data indicate that a minimum catheter:trachea cross-sectional area ratio of 0.03 may be required to obtain oxygenation and ventilation with low-flow oxygen rates of 3 to 5 L/min in cats.

Airway Obstruction↗

PubMedDate not supplied

Measles immunisation coverage in urban slums.

A cross-sectional, community-based study was conducted in 32 slums of Udaipur city to assess the prevalence of missed opportunities for measles immunization, reason for their occurrence and potential impact of avoiding them on measles immunization coverage. Two hundred and sixty-five children, between the age of 9 and 24 months were enlisted for the study, using a practical cluster sampling method. Immunization status of the children, visits to health facilities after 9 months of age and reasons for non-immunization were noted. Missed opportunities for measles immunization was defined as any visit by an eligible child to a health facility, which did not result in his/her vaccination. Measles immunization coverage amongst the study population was 50.61%. The prevalence of missed opportunities for measles immunization was 14.3%. Not offering measles immunization at curative visits (86.9%) was the major reason for missing opportunities. Avoiding all missed opportunities could have increased the measles immunization coverage to 64.9%.

Child, Preschool↗