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Biomedical subjects

E Gardner

Publications and source records attributed to E Gardner.

At least 19 recordsLinked to original sources

Prognostic factors in ossiculoplasty: a statistical staging system.

OBJECTIVE: To determine factors that predict hearing results using a standard prosthesis system. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: All patients undergoing ossiculoplasty with the Dornhoffer HAPEX partial and total ossicular replacement prostheses (PORP and TORP) from February 1995 to May 1999 who had documented postoperative follow-up and no congenital atresia or stapes fixation. A total of 185 patients (200 ears), 105 men and 80 women, were evaluated. INTERVENTIONS: Ossiculoplasty with the Dornhoffer prostheses. MAIN OUTCOME MEASURES: Hearing results using a four-frequency pure-tone average air-bone gap (PTA-ABG). Multivariate statistical analysis determined the effect of mucosal status, ossicular chain status, and type of reconstruction techniques on hearing. RESULTS: The PTA-ABGs were 13.4+/-8.1 dB and 14.0+/-8.4 dB for the PORPs (n = 114) and TORPs (n = 86), respectively, which was not statistically different. When the malleus handle was present (n = 126), the PTA-ABG was 11.6+/-6.2 dB, compared with 16.9+/-10.1 dB when it was absent (n = 74), which was statistically significant (p < 0.05). Mucosal fibrosis, drainage, revision ear surgery, and type of surgical procedure had a significant detrimental impact on hearing. The type of pathologic process (perforation vs. cholesteatoma) had no significant impact on hearing results. CONCLUSIONS: The revised staging system, the Ossiculoplasty Outcome Parameter Staging Index, more adequately predicts hearing outcome in this series of 200 cases.

Adolescent↗

5-HT receptor knockout mice: pharmacological tools or models of psychiatric disorders.

The molecular diversity of cloned serotonin receptor subtypes in the brain makes it difficult to understand the specific modulatory roles played by different receptors. In order to understand the role of the 5-HT1B receptor subtype in behavior and neuropsychiatric disorders, we have been studying genetic knockout mice lacking the 5-HT1B receptor. The 5-HT1B knockout mice show evidence of increased aggression and impulsivity, behavioral patterns that are also associated with reduced 5-HT function. They also show reduced or absent locomotor stimulation to some serotoninergic drugs, indicating that the locomotor effects of these drugs require the 5-HT1B receptor. However, in some cases, data obtained with knockout mice conflicts with the pharmacological data. The 5-HT1B receptor knockout mice show a phenotype of increased vulnerability to drugs of abuse such as cocaine. However, pharmacological studies suggest that 5-HT1B stimulation enhances the effects of cocaine, while 5-HT1B blockade can attenuate some of the effects of cocaine. Compensations that enhance dopamine function appear to be responsible for the drug-vulnerable phenotype of 5-HT1B receptor knockout mice. By studying these compensations and changes in neural function, we can learn more about the fundamental mechanisms underlying addiction. The 5-HT1B knockout mice should be considered a model for the disease state of vulnerability to drugs of abuse, rather than a direct pharmacological model of 5-HT1B receptor function.

3,4-Dihydroxyphenylacetic Acid↗

Nutrients and the surgical patient: current and potential therapeutic applications to clinical practice.

Malnutrition and weight loss are associated with alterations in cellular physiology and organ function, which are of importance for the surgical patient. Pre-operative weight loss can lead to increased post-operative morbidity and mortality. This review addresses the following questions: (a) what effects can key nutrients have on the immune system, metabolism and wound healing in man, and which may be of potential benefit to the surgical patient? (b) can clinically beneficial effects be demonstrated if patients receive nutritional supplementation with one of these key nutrients? (c) what effects does nutritional supplementation with combinations of these nutrients have on clinical outcomes?

Humans↗

The status of health technology assessment worldwide. Results of an international survey.

Health technology assessment (HTA) has increasingly become a valuable tool to examine effectiveness, quality of care, patient outcomes, and cost-effectiveness of health care technologies. In 1994 and 1995, a survey was conducted to document the scope of worldwide HTA activities; 103 organizations from 24 countries responded. This paper summarizes the results of this international survey, including a description of each country's program, types of technologies assessed, methodologies used, and dissemination approaches. Results for Canada, the United States, and European and other countries are presented separately.

Canada↗

Effects of functional electrical stimulation on the joints of adolescents with spinal cord injury.

Nineteen adolescent subjects with complete spinal cord injuries resulting in paraplegia or tetraplegia participated in a functional electrical stimulation (FES) program consisting of computerized, controlled exercise and/or weight bearing. The effects of stimulated exercise and standing/walking on the lower extremity joints were prospectively studied. Plain radiographs and MRIs were obtained prior to and following completion of the exercise and standing and walking stages. In addition, the joints of five subjects were studied with synovial biopsies, arthroscopy, and the analysis of serum and synovial fluid for a 550 000 dalton cartilage matrix glycoprotein (CMGP). Pre-exercise joint abnormalities secondary to the spinal cord injury improved following the stimulation program. None of the subjects developed Charcot joint changes. Upon standing with FES, one subject with poor hip coverage prior to participation developed hip subluxation which required surgical repair. No other detrimental clinical effects occurred in the lower extremity joints of subjects participating in an FES program over a 1-year period.

Adolescent↗

Examination of steroid-induced changes in LHRH gene transcription using 33P-and 35S-labeled probes specific for intron 2.

We previously demonstrated that estrogen, but not progesterone, induces a increase in LHRH messenger RNA levels between 0800 and 1200 h in numerous of the rostral preoptic area/organum vasculosum of the lamina terminalis (rPOA/OVLT). To determine whether these changes are a result of increased transcription, we used in situ hybridization histochemistry to examine the temporal effects of estradiol (E2) and progesterone on cellular levels of intron-2-containing LHRH heteronuclear RNA transcripts. To make our method sufficiently sensitive to detect changes in these levels, we used 33P/35S probes to minimize both background and grain stacking over labeled cell nuclei. We found that levels of LHRH heteronuclear RNA rose between 0800 and 1000 in OVX, E2-treated rats, remained elevated at 1200 h, and declined by 1400 h. Progesterone did not affect these E2-induced changes. Our results suggest that an E2-dependent signal initiates LHRH gene transcription in neurons of the rPOA/OVLT hours before LHRH release begins and that progesterone does not affect this signal.

Animals↗

Research grants.

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Financing, Government↗

A multiple interval physical map of the pericentromeric region of human chromosome 10.

Five intervals in the pericentromeric region of human chromosome 10 have been defined using a panel of somatic cell hybrids carrying portions of the chromosome. The map positions of twelve markers, consisting of four genes and eight anonymous DNA segments, have been localized by assignment to one of the five intervals. Several other markers could be placed in specific intervals by genetic linkage to assigned loci. When previously published data are incorporated, the summary map of the pericentromeric region encompasses thirty-two loci in bands 10p11.2-q11.2.

Base Sequence↗

Specific mutations of the RET proto-oncogene are related to disease phenotype in MEN 2A and FMTC.

We have analysed 118 families with inherited medullary thyroid carcinoma (MTC) for mutations of the RET proto-oncogene. These included cases of multiple endocrine neoplasia types 2A (MEN 2A) and 2B (MEN 2B) and familial MTC (FMTC). Mutations at one of 5 cysteines in the extracellular domain were found in 97% of patients with MEN 2A and 86% with FMTC but not in MEN 2B patients or normal controls. 84% of the MEN2A mutations affected codon 634. MEN 2A patients with a Cys634 to Arg substitution had a greater risk of developing parathyroid disease than those with other codon 634 mutations. Our data show a strong correlation between disease phenotype and the nature and position of the RET mutation, suggesting that a simple, constitutive activation of the RET tyrosine kinase is unlikely to explain the events leading to MEN 2A and FMTC.

Base Sequence↗

Haplotype analysis of MEN 2 mutations.

Multiple endocrine neoplasia type 2 (MEN 2) is a dominantly inherited cancer syndrome which affects thyroid C cells, and with variable frequency, the adrenal medulla, parathyroid and enteric autonomic ganglia. The syndrome is due to germline mutation in the receptor tyrosine kinase gene, RET. We have recently shown an unexpected correlation between one particular RET mutation, cys634-->arg, and the probability of parathyroid involvement in families with MEN 2A. Here we use haplotype analysis in the families to show that this correlation is not explained by a single founder chromosome which carries both the cys634-->arg mutation and a separate allele conferring susceptibility to parathyroid abnormality, but is probably due to the cys634-->arg mutation itself. The results also indicate that new mutations to MEN 2 are not infrequent.

Amino Acid Sequence↗

Point mutation within the tyrosine kinase domain of the RET proto-oncogene in multiple endocrine neoplasia type 2B and related sporadic tumours.

The susceptibility loci for the three multiple endocrine neoplasia (MEN) type 2 syndromes have been mapped to the region of chromosome 10q11.2 containing the RET proto-oncogene, which codes for a receptor tyrosine kinase. The majority of MEN 2A and familial medullary thyroid carcinoma results from missense mutations within one of five cysteine codons in the extracellular domain of the RET proto-oncogene. We now report a missense mutation, resulting in the substitution of a threonine for a methionine at codon 918 in the tyrosine kinase catalytic domain, in the germline of 26 of 28 apparently distinct families with MEN 2B. DNA from five of 13 apparently sporadic MTC and one of 12 apparently sporadic phaeochromocytomas harboured a similar mutation, but the corresponding germline DNA was wildtype in each case.

Adenoma↗

Medical physics.

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Diagnosis, Computer-Assisted↗

The feasibility and efficacy of early discharge planning initiated by the admitting department in two acute care hospitals.

To determine the feasibility and efficacy of early discharge planning, initiated by admitting department personnel, a randomized, controlled trial was undertaken in 2 acute care, university-affiliated hospitals. The intervention tested was referral of patients by admitting personnel to nursing, social work, physiotherapy, occupational therapy, or dietary services for potential discharge planning. A 1-page, 65-item questionnaire was designed to identify patients for referral to the various allied health services. A copy of this was sent to the appropriate service, according to predefined criteria. The questionnaire took an average of 4 min to complete. The criteria used were highly predictive of length of stay, the most important being age, followed by living outside St. John's, admission within the previous 3 months, emergency admission, and being in need of community services. In Hospital A, the cases (n = 421) referred for early discharge planning had significantly shorter length of stay (Mantel-Cox, p = 0.03) than controls (n = 420), who were identical for all factors predictive of prolonged length of stay. The reduction in length of stay amounted to a mean of 0.8 d. In Hospital B (n = 758), the intervention was less effective because of a lower proportion of patients with factors associated with prolonged hospital stay and, perhaps, because of inadequate implementation of the program. We conclude that identification, by admitting department personnel, of patients who may benefit from early discharge planning is feasible. This process will reduce length of hospital stay, but its effectiveness is dependent on case mix variables and enthusiastic implementation of the program.

Acute Disease↗

1993 up & comers.

The achievements of the healthcare industry in the 21st century will depend on the quality of its leadership. In recognition of the contributions of the new generation of healthcare executives, MODERN HEALTHCARE salutes its 1993 Up & Comers. They are a group of healthcare professionals, all 40 or younger, who have refused to be restricted by the ways of the past. Instead, they have contributed to efforts to improve the quality of medical care, expand access to the system and reconfigure the delivery system. The group, whose accomplishments are outlined in the following pages, were selected from a field of nearly 50 candidates nominated by MODERN HEALTHCARE's editorial staff and magazine readers.

Adult↗