Hydrocephalus and pregnancy: the medical implications of maternal shunt dependency.
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Adult↗
Biomedical subjects
S L Kinsman
Publications and source records attributed to S L Kinsman.
The cost of preventable conditions in adults with spina bifida.
Adults with spina bifida are at risk of developing secondary health conditions that are causally related to the primary condition and are to some degree preventable. By investigating preventable secondary conditions in adults with spina bifida, we can determine the burden of care that might be reduced if preventive strategies were developed. We audited hospitalizations of adults with spina bifida to gain insight into serious secondary conditions in this population. We reviewed all admissions of adults with spina bifida to a large American tertiary care center (Johns Hopkins Hospital; Baltimore, Maryland) over 11 years. We determined the discharge diagnoses for each admission and the hospital costs associated with admission. We defined preventable secondary conditions in this adult population and calculated the percentage of total admissions and of total costs for these secondary conditions. The patient population consisted of spina bifida patients 18 years and over admitted from January 1982 to December 1992, including 59 females and 39 males. 77 of our patients were identified as white, 20 as black, and 1 as "other". Patient age ranged from 18 to 61 years with an average age of 25.8 years. There were 353 admissions and admissions per patient ranged from 1 to 25 over the 11-year period. The average number of admissions per patient was 3.6 and the average length of stay for all admissions was 11.2 days. Of the 353 total admissions, 166 (47.0%) were due to potentially preventable secondary conditions such as serious urologic infections, renal calculi, pressure ulcers, and osteomyelitis. For admissions due to these secondary conditions, the average length of stay was 12.5 days. The total hospital costs, excluding professional fees, were $175,885, $247,355, and $437,262 for 1990, 1991, and 1992 respectively. Permanent loss of function resulting from secondary conditions, not investigated in this study, can also be a source of long-term financial and psychological cost to the patient. This study found a high number of patients with multiple admissions and that many admissions qualified as potentially preventable. More information is needed if we are to understand the factors associated with secondary health conditions in adults with spina bifida. We need to investigate the roles played by physician and patient knowledge, attitudes, and behaviors in contributing to patient outcome.
Adolescent↗
RNA editing of a human glutamate receptor subunit.
AMPA receptors are comprised of individual subunits, and the divalent cation permeability of assembled AMPA receptors is determined by a single amino acid residue in the second transmembrane region of the GluR-B subunit. At this site, GluR-B subunits contain an arginine while other AMPA receptor subunits contain glutamine. Interestingly, the murine gene for GluR-B actually specifies a glutamine at the divalent cation permeability site. The appearance of arginine and not glutamine in the mature GluR-B protein is thought to be a result of RNA editing of the GluR-B messenger RNA. In that AMPA receptors are thought to mediate the bulk of fast excitatory signalling within the mammalian central nervous system, this process of RNA editing may play a pivotal role in normal neural function by mediating divalent cation permeability of AMPA receptors. Disruptions of RNA editing could lead to phenotypically altered AMPA receptors, with implications for pathogenic brain processes. We report that the human GluR-B gene sequence is also edited such that there is a difference between the human GluR-B gene and the complementary DNA (cDNA), as demonstrated both with allele-specific polymerase chain reaction (PCR) and restriction enzyme digestion of PCR products. Thus, as in the rodent brain, RNA editing of an AMPA receptor subunit appears to be an important process in the human brain. Disruptions of RNA editing may have neuropathological consequences.
Base Sequence↗
A reverse transcription-polymerase chain reaction study of p75 nerve growth factor receptor gene expression in developing rat cerebellum.
The actions of the neurotrophins are mediated through specific receptors. Nerve growth factor (NGF), the prototypic neurotrophin, binds to receptors of both high and low affinity. A protein 75 kDa in size (p75NGFR) binds NGF, as well as brain-derived neurotrophic factor and neurotrophin 3, with low affinity. Recent investigations suggest that this protein may also be a component of the high affinity NGF receptor complex. To study gene expression of the p75NGFR molecule, we used a sensitive reverse transcription-polymerase chain reaction (RT-PCR) assay to measure levels of its messenger RNA (mRNA) in small samples of total RNA. The assay is based on using a shortened p75NGFR cRNA as an internal RNA standard to control for variability in reverse transcription and polymerase chain amplification. We measured p75NGFR mRNA levels in the rat cerebellum during ontogeny to further study the transient developmental increase in receptor gene expression known to occur in this brain region during the early postnatal period. We found that p75NGFR mRNA levels were most abundant at postnatal day 2, and then declined to lower levels throughout postnatal development and in the adult. Northern blot analysis of the same total RNA samples used in our RT-PCR assay verified that p75NGFR expression is highest in the early postnatal period. These results confirm those of previous studies accomplished with much larger amounts of RNA using ribonuclease protection or northern blot assays. The use of an RT-PCR assay that utilized an internal standard also controls against changes in RNA complexity which can affect the measurement of message abundance across developmental stages.(ABSTRACT TRUNCATED AT 250 WORDS)
Aging↗
Urolithiasis associated with the ketogenic diet.
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Age Factors↗
Mauthner axon diameter and impulse conduction velocity decrease with growth of goldfish.
Conduction velocities of antidromically evoked impulses along the goldfish Mauthner axon were found to be inversely correlated with body length. To test the hypothesis that such a relation is accompanied by a reduction in axonal diameter with increasing fish size, Mauthner axon diameters were measured. A parabolic relationship with respect to body length was obtained, axonal diameter being maximal in 9.5 cm fish. To our knowledge, this is the first report of a decrease in conduction velocity and axonal size during growth of an organism were functioning of the cell is maintained.
Aging↗
Efficacy of the ketogenic diet for intractable seizure disorders: review of 58 cases.
The ketogenic diet was developed in the 1920s as a treatment for intractable childhood seizures when few antiepileptic drugs (AEDs) were available. There are still children whose seizures are refractory even to modern therapy, but use of the ketogenic diet appears to be waning. At Johns Hopkins, we continue to believe that the diet is very effective and well accepted by patients and families. To reevaluate our opinion of the efficacy and acceptability of this form of therapy in patients cared for in the 1980s with the newer AEDs, we analyzed the records of 58 consecutive patients who had been started on the diet. Before using the diet, 80% of the patients had multiple seizure types and 88% were treated with multiple AEDs; these children were among our most intractable patients. Despite this, seizure control improved in 67% of patients with the ketogenic diet, and actuarial analysis indicated that 75% of these improved patients continued the diet for at least 18 months. Sixty-four percent had AEDs reduced, 36% became more alert, and 23% had improved behavior. The improvement in these patients with intractable seizures and the length of time that families maintained the regimen indicate that the ketogenic diet continues to have a very useful therapeutic role in selected patients and their families.
Adolescent↗