Biomedical subjects

M P Frank

Publications and source records attributed to M P Frank.

6 recordsLinked to original sources

PubMed2005

Maternal serum soluble fms-like tyrosine kinase 1 concentrations are not increased in early pregnancy and decrease more slowly postpartum in women who develop preeclampsia.

OBJECTIVE: We measured maternal serum soluble fms-like tyrosine kinase 1 concentrations across pregnancy and immediately postpartum in women who developed preeclampsia and normal pregnant women. STUDY DESIGN: This was a nested case control study of 113 normal pregnant women and 55 women with preeclampsia. RESULTS: Serum soluble fms-like tyrosine kinase 1 concentrations increased similarly in early pregnancy in both groups. Mean serum soluble fms-like tyrosine kinase 1 concentrations were increased in women who developed preeclampsia, compared with normal pregnant women, and this increase was most pronounced in severe preeclampsia. However, many women with preeclampsia had soluble fms-like tyrosine kinase 1 concentrations similar to normal pregnant women. Lastly, soluble fms-like tyrosine kinase 1 decreased rapidly after delivery, but this decrease was significantly slower in women with severe preeclampsia. CONCLUSION: Increased soluble fms-like tyrosine kinase 1 is not an early-pregnancy event among women who later develop preeclampsia. Increased soluble fms-like tyrosine kinase 1 is more likely to be present in women with severe preeclampsia, but it is not present in all women with preeclampsia. Soluble fms-like tyrosine kinase 1 concentrations decrease more slowly after delivery in women with preeclampsia, consistent with a decreased rate of excretion or continued production.

Adult↗

PubMed2003

Lichenoid reactions of murine mucosa associated with amalgam.

BACKGROUND: In 97% of all patients with oral lichenoid reactions (OLR) associated with dental amalgam a removal of the fillings leads to a decline of the lesions, as a minimum. OBJECTIVES: The aim of this study was to determine if contact allergic or local toxic effects or both may contribute to OLR using an animal model with mercury-sensitive and non-sensitive rats. METHODS: Twenty Brown Norway rats, which have a genetic predisposition for an autoimmune syndrome after exposure to mercury and 20 Lewis rats, not mercury sensitive, were treated as follows: 10 animals of each group were sensitized with a low dose of mercuric chloride. Half of all animals received local exposure of the right buccal mucosa to amalgam (left: control), the others to amalgam alloy free of mercury. All rats were patch tested with an amalgam series. RESULTS: After 20 days of exposure 96% of all animals showed white mucosal lesions restricted to the contact zone of the alloy on the treated side, but only up to 25% had a positive patch test reaction to amalgam or inorganic mercury (INM). The lesions showed no relation to species, alloy, sensitization or patch test reaction. CONCLUSIONS: While allergic mechanisms may contribute to mucosal contact lesions in Brown Norway rats, this is less probable in Lewis rats. Mercury in general appears to be irrelevant in the development of ORL in this study. If this holds true for humans as well, patch testing with an amalgam series may be helpful in a minor fraction of all patients with OLR.

Animals↗

PubMed1983

Electrical stimulation of the cochlear nerve in deafness mice.

The deafness mouse mutant provides a useful animal model for studying the central consequences of complete auditory deprivation during development. The object of this study was to record inferior colliculus-evoked potentials in mutant and control mice, using short electrical pulses to stimulate either the whole cochlea or the cochlear nerve directly. In both experiments, evoked potentials were readily recorded in the mutant and control mice, indicating that some central connections are functional, even though the auditory pathway has received no stimulus-related input throughout development. The results are relevant to the clinical problem of restoring auditory function in the profoundly deaf using peripheral electrical stimulation.

Animals↗

PubMed1982

Preservation of central auditory function in the deafness mouse.

Deafness mice are profoundly deaf from birth as a result of genetically determined cochlear dysfunction. Evoked potentials in response to direct electrical stimulation of the cochlear nerve can readily be recorded in the inferior colliculus of deafness mice, and such responses are larger in amplitude than those in control mice. These observations indicate that at least some central connections become functional in the deafness central auditory pathway in the absence of peripheral stimulation, and are relevant to the general problem of restoring function by direct nerve stimulation in the profoundly deaf.

Animals↗

PubMedDate not supplied

The quivering mutant mouse: hereditary deafness of central origin.

Mice homozygous for the recessive quivering gene are largely unresponsive to sound, although their cochleas appear normal by light microscopy and cochlear hair cells do not degenerate with age. Cochlear potentials and inferior colliculus evoked responses were recorded in quivering mice (qv/qv) and in littermate controls (+/qv or +/+). There were no significant differences between mutants and controls in cochlear microphonic amplitudes or compound action potential thresholds, amplitudes and latencies. However, inferior colliculus evoked responses in mutants were small in amplitude and abnormal in waveform. Latencies were long and thresholds were elevated by at least 50 dB at all frequencies tested. These data suggest that the genetic hearing impairment in quivering mice is retrocochlear.

Action Potentials↗

PubMedDate not supplied

Brainstem responses in the quivering mutant mouse.

The recessive quivering gene in mice produces general neurological abnormalities and deafness. Previous work indicated that cochlear responses (microphonics and compound action potentials) were normal in the quivering (qv/qv) mouse, but inferior colliculus evoked potentials had poor thresholds and abnormal latencies. The object of the present study was to record evoked potentials from the cochlear nucleus (CN) in quivering and control mice, and also to record surface responses. The CN evoked response in control mice consisted of two prominent positive peaks. The first peak appeared normal in the quivering CN, resulting in normal thresholds for detection of the response. However, the second peak in mutants was smaller and of longer latency. Surface responses in quivering showed a normal first wave followed by an abnormal wave pattern. It was concluded that the input from auditory nerve to CN in quivering is probably normal and that the central deficit in quivering is evident at the level of CN.

Animals↗