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Biomedical subjects

D H Brown

Publications and source records attributed to D H Brown.

At least 37 records · Page 2Linked to original sources
PubMed1998

Education of medical practitioners in otitis media management.

OBJECTIVE: Medical education generally is so complex today, compared to just 50 years ago, that we unfortunately brush over the education of common conditions and their management in favour of more esoteric and complicated disease. Otitis media (OM) is no exception, and now more than ever, we must strive to find innovative ways to convey the mandatory information to medical students and practising physicians as we approach the millennium. This article addresses the problems of teaching the essential information and management skills needed by medical practitioners by reviewing what has gone on in the past, updating the present situation, and suggesting new strategies for the future.

Child↗
PubMed1997

Ring chromosome X in a child with manifestations of Kabuki syndrome.

A female patient with the karyotype 45,X/46, X, r(X)(p11.2 q13) and severe developmental delay, prominent fingertip pads, long palpebral fissures, short stature, and history of hypotonia had a phenotype reminiscent of Kabuki syndrome. We hypothesized that overexpression of X chromosome-derived sequences might be associated with the Kabuki-like phenotype observed. The nature and parental origin of this small-ring X were ascertained using a combination of genotyping with microsatellite markers and quantitative Southern blotting. PCR-based genotyping demonstrated heterozygosity at X-linked loci SBMA (Xq11-q12) and DXS227 (Xq13.1). Hemizygosity was observed at several loci: DMD STR-49 (Xp21.2), DXS1003 (Xp11.23), DXS988 (Xp11.21), DXS101 (Xq21.3), FMR-1 (Xq27.3), and DXYS64 (Xq28). This ring X chromosome is paternally derived since only maternal alleles are inherited at three informative microsatellite loci. Results of FISH and RT-PCR experiments indicate that the XIST locus is missing in the ring X chromosome and not expressed. These data indicated a large deletion of the X chromosome consistent with a small-ring X chromosome with approximate breakpoints near p11.2 and q13. These results are comparable to the observation of others where an atypically severe phenotype has been associated with the presence of an r(X), or small mar(X).

Abnormalities, Multiple↗
PubMed1997

Oromandibular reconstruction with the fibular free flap. Analysis of 50 consecutive flaps.

OBJECTIVE: To evaluate the results and functional outcome associated with fibular free flap reconstruction of orofacial and mandibular defects. DESIGN: We conducted a retrospective analysis of 50 consecutive fibular free flaps during a 3-year period. Forty patients were available for follow-up, which ranged from 4 to 39 months. SETTING: Academic tertiary care referral medical center. PATIENTS: Fifty consecutive mandibular reconstructions using the fibular free flap were performed on 47 patients. Thirty-five patients (74%) underwent primary reconstruction. Sixty-six percent of the mandibular defects were anterior or combined anterolateral types; the remainder were pure lateral defects. In 38 patients (81%), a skin paddle was included with the flap to provide either a mucosal lining or skin cover, whereas in only 9 patients (19%), bone was used alone. MAIN OUTCOME MEASURES: Factors reflecting functional properties and processes as well as complications of the upper aerodigestive tract were evaluated clinically and radiographically. RESULTS: Four flaps required reexploration as emergencies, and none were successfully salvaged (8.5% failure). Three patients underwent further free vascularized fibula transfer with 1 failure. During follow-up, swallowing was normal in 25 patients (64%), oral continence was normal or almost normal in 26 patients (67%), and speech was normal or easily intelligible in 35 patients (90%). Aesthetic results were excellent or acceptable in 37 patients (95%). CONCLUSIONS: Our results reveal that the vascularized fibular free flap is very suitable with an excellent success rate for reconstructing both the composite or simple long-spanned mandibular defect. The overlying skin island is reliable and provides lining or coverage for intraoral and extraoral defects. Superior functional cosmetic results are expected in the majority of patients, while donor site morbidity is minimal.

Adult↗
PubMed1997

Community-acquired notifiable infectious diseases in a pediatric hospital: effect on infection control work load.

In a study of the impact of notifiable communicable disease admissions on infection control work load, we found notifiable disease cases to be responsible for less than 10% of admissions but 27% of infection control ward visits and to require extensive community liaison. Measures of work load based on nosocomial infections alone will underestimate infection control activity considerably.

Child↗
PubMed1997

Stabilized expression of mRNA is associated with mycobacterial resistance controlled by Nramp1.

Control of innate resistance to the growth of mycobacteria is mediated by a gene termed Nramp1. Although the role of the protein product of Nramp1 in mediating resistance to mycobacterial growth is not known, the effect of the gene is pleiotropic and it has been suggested that the gene controls macrophage priming for activation. We have found that the functional capacity of macrophages from Mycobacterium bovis BCG-susceptible mice can be suppressed by corticosterone, while the function of macrophages from BCG-resistant mice remains unaffected. In this study, we show that corticosterone differentially affects the stability of mRNAs of several recombinant gamma interferon (rIFN-gamma)-induced genes. Treatment of macrophages from BCG-susceptible mice with corticosterone accelerates the decay of Nramp1 mRNA. The mRNA of IFN-gamma-induced genes of macrophages from BCG-resistant mice was more stable than the mRNA of macrophages from BCG-susceptible mice in the presence or absence of corticosterone. The results of this investigation suggest that Nramp1 acts by stabilizing the mRNA of genes associated with macrophage activation, thus accounting for the functional differences that have been attributed to these macrophage populations.

Animals↗
PubMed1997

Penetrating and blunt neck trauma: 10-year review of a Canadian experience.

OBJECTIVES: To determine if selective management of blunt and penetrating neck trauma is still appropriate in Canadian tertiary care centres because of differences in trauma demographics. A key secondary objective was a descriptive analysis of the Canadian head and neck trauma patient population and outcomes. DESIGN: A retrospective case series. SETTING: An academic tertiary care centre. PATIENTS: All 85 patients admitted between 1982 and 1992 with a diagnosis of blunt (19) or penetrating (66) neck trauma. INTERVENTIONS: Emergent neck explorations (29 patients), selective nonoperative management (20 patients) and elective neck exploration (17 patients). MAIN OUTCOME MEASURES: Hospital stay, complication rate, rate of negative exploration (elective management, emergent exploration) and rate of secondary exploration (selective management), and outcome and complication rate. The entire population was described demographically. RESULTS: In 66 patients the injuries were penetrating, with the majority being of low kinetic energy. The patients who underwent elective mandatory exploration were comparable to those who underwent selective nonoperative management. The length of stay in hospital for the selective group was significantly less (p = 0.0008), and no patient in this group required later operative management of a missed injury. However, 41% of patients who underwent elective mandatory neck exploration had no significant injury. The complication rate in the two groups was similar. CONCLUSIONS: The patients managed selectively had no difference in outcome from those who underwent mandatory elective exploration. In Canada, because of the lower incidence of high-morbidity zone I and zone III injuries and the high incidence of low kinetic energy trauma with a predilection to zone II, the surgeon may consider a selective approach where appropriate.

Adolescent↗
PubMed1997

Informed consent in head and neck surgery: how much do patients actually remember?

OBJECTIVE: This study was conducted to evaluate the effectiveness of informed consent in head and neck surgery by testing patient recall of potential complications from thyroidectomy, parathyroidectomy, and parotidectomy. DESIGN: A prospective design was used. SETTING: The setting was an academic tertiary care centre. METHODS: Fifty-four patients undergoing thyroidectomy, parathyroidectomy, or parotidectomy were consented by verbal contact by the operating surgeon with a specific preoperative checklist of complication and side effects. One week to 2 months after consent, the patients were surveyed for recall of potential complications. MAIN OUTCOME MEASURES: Rate of recall was related to various parameters including patient age, sex, level of education, occupation, and length of time from the consent interview to the recall interview. RESULTS: The overall recall rate for all procedures was 48%. Those patients who recalled over 50% of the complications were younger (p = .04) and better educated (p = .04). The gender of the patients did not appear to influence recall success (p = 1.00), even when facial scar or paralysis was considered. CONCLUSION: A significant relationship exists between education level and patient age and the rate of patient recall of potential complications of surgery.

Adult↗
PubMed1996

Ambulatory care certificate program for pharmacists.

An ambulatory care certificate program tailored to meet the educational needs of Department of Veterans Affairs (VA) and Navy pharmacists is described. In 1992, the College of pharmacy, University of Illinois at Chicago, worked with the VA and the Navy to design an ambulatory care certificate program for pharmacists in VA and Navy hospitals. The pilot course consisted of 103 hours of didactic and experiential education. The 10 didactic modules covered both disease management and clinical skills. The experiential component incorporated pharmaceutical care steps as applied to therapeutic areas taught in the course. Although the pilot course met most of the original objectives, several unanticipated problems emerged, including distance learning issues, the number of hours for completing the course requirements, learner variance, the impact of institutional support on participants' academic success, participants' difficulty in assimilating education into practice, and difficulty with the clinical evaluation tool developed for the course. The course was modified over the next year to address these problems. Now in its fourth year, the course is offered nationally to the VA and the Department of Defense. In the first three years, 72 of 99 enrolled pharmacists completed the course. An ambulatory care certificate program helps Navy and VA pharmacists develop patient care skills.

Ambulatory Care↗
PubMed1996

Stable transformation and regulated expression of an inducible reporter construct in Candida albicans using restriction enzyme-mediated integration.

To allow the regulated expression of cloned genes in Candida albicans, a plasmid was constructed using the inducible promoter of the C. Albicans MAL2 gene. To demonstrate that the MAL2 promoter could regulate cloned genes placed under its control, a fusion construct was made with the coding sequence of the C. albicans URA3 gene. This plasmid was introduced into a Ura- strain of C. albicans using the process of restriction enzyme-mediated integration (REMI). This procedure involves the transformation of the BamHI-linearized plasmid in the presence of BamHI enzyme. The majority of transformants generated contained insertions of the plasmid at chromosomal BamHI sites. All transformants examined were inducible for URA3 expression, which was determined by growth analysis and by measuring the level of URA3 gene product activity. The URA+ phenotype of the transformants was stable during growth under nonselective conditions. This system offers the advantages of stable transformation, easy recovery of integrated DNA, and inducible expression of genes in C. albicans.

Base Sequence↗
PubMed1996

Myoepithelial cells actively proliferate during atrophy of rat parotid gland.

Despite limited supporting evidence, salivary gland myoepithelial cells are said to be differentiated cells with little or no capacity to replicate; they presumably develop from stem cells. This study investigated the proliferative potential of myoepithelial cells with an antibody to proliferating cell nuclear antigen and a rat model. This model involved clamping of the parotid duct causing atrophy of the gland and then releasing the duct followed by gland regeneration. Rats were sacrificed at time points during atrophy and regeneration phases and the number and location of cycling myoepithelial cells assessed. Cycling myoepithelial cells were identified with double immunohistochemical staining, cycling cells with proliferating cell nuclear antigen-positive nuclei within muscle-specific actin-positive cytoplasm (the latter identified with antibody HHF35). The results show that baseline proliferative rates of myoepithelial cells in both the resting and fully regenerated gland ranged from 0.3% to 2%, similar to rates for other major cell types in the normal rat gland. A peak myoepithelial cell proliferative rate of 23% occurred at day 5 during the atrophy phase. Rates during the regenerative phase were not significantly different than the baseline levels. Similarities of rat and human parotid gland and the definite proliferative capacity of myoepithelial cells indicates that these specialized cells must be considered one of the potential progenitor cells for human salivary gland tumors.

Actins↗
PubMed1996

Tobacco, alcohol, and oral cancer: the patient's perspective.

It is well known that smoking, chewing tobacco, and alcohol play a significant role in the etiology of oral cancer. Although this is common knowledge in the medical community, it appears that patients are not aware of this association. We performed a prospective study on all patients newly diagnosed with oral cancer and a control group without any head and neck cancer. Patients completed a questionnaire assessing their awareness of these causative factors. Other parameters measured as possible influences of patient perception included patient age, sex, smoking status, education level, occupation, and place of residence. Patients were also questioned about their knowledge of the causes of lung cancer to allow for comparison. A total of 134 patients were questioned, with 22 of the patients assigned to the oral cancer group and the second group being comprised of 112 patients without head and neck cancer. Only 20 patients (14.9%) were aware of the causative factors of oral cancer. There was no significant difference in the knowledge of causation when comparing the cancer and control group. The patient age, sex, smoking status, or place of residence did not affect their knowledge of the causes of oral cancer. There was a highly significant difference between patients of different education levels and occupations, with the more educated and higher level occupations being better informed about the causes of oral cancer. In contrast, the majority of patients were aware of smoking as a causative factor in the development of lung cancer. The results from this study demonstrate a serious lack of knowledge in the general population of known causes of oral cancer. The relevant issues are discussed and recommendations are made.

Adolescent↗
PubMed1996

Value of nasal radiographs in nasal trauma management.

OBJECTIVE: To assess the value of routinely acquiring plain nasal radiographs in patients following nasal trauma both clinically and cost effectively. DESIGN: A questionnaire was devised to determine the factors that influence physicians to order nasal x-rays and whether or not the results of these radiographs influence management. SETTING: The questionnaire was distributed to the otolaryngology staff and residents, emergency physicians, and family physicians affiliated with the University of Toronto. METHODS: Descriptive statistics were employed. MAIN OUTCOME MEASURES: Percentages of reasons for ordering nasal x-rays and their part in treatment management. RESULTS: The commonest reasons for ordering nasal x-rays in these cases included perceived severity of injury and detection of unsuspected facial fractures, as well as presumed need for medicolegal documentation. CONCLUSIONS: Nasal x-rays are not of substantial medicolegal value and do not play a role in the treatment of the patient. Nasal radiographs are not a cost-effective investigation in the management of trauma to the nose, and their routine use should be abandoned.

Cost-Benefit Analysis↗
PubMed1996

Evaluation of vocal function in unilateral vocal fold paralysis following thyroplastic surgery.

Perceptual, acoustic, and aerodynamic measures of vocal function were examined, pre- and post-treatment, in nine patients who had received thyroplastic (type I) surgery for unilateral vocal fold paralysis. Following thyroplasty, the patients showed significant improvements in the following perceptual and acoustic measures of vocal function: perceived breathiness, maximum phonation time, s/z ratio, vocal shimmer, and signal-to-noise ratio. Significant post-treatment changes were also observed in the following aerodynamic measures of phonation: air pressure, average airflow, laryngeal resistance, and breath group duration. These findings suggest that a combination of perceptual, acoustic, and aerodynamic measures of vocal function may be useful for comparing the relative effectiveness of different treatment procedures (i.e., thyroplasty vs. Teflon injection) in unilateral vocal fold paralysis.

Adult↗
PubMed1996

Transjugular intrahepatic portosystemic shunt: efficacy for the treatment of portal hypertension and impact on liver transplantation.

Variceal bleeding (VB) and ascites refractory to diuretics (RA) represent a significant cause of morbidity and mortality in patients with portal hypertension. Transjugular intrahepatic portosystemic shunts (TIPS) have been used effectively in patients with these complications, especially those individuals awaiting orthotopic liver transplantation (OLT). From April 1992 to July 1995, 41 adult patients underwent an attempt at TIPS placement for refractory VB or ascites at Cedars-Sinai Medical Center. Technical success was achieved in 37 of 41 cases (90.3%) with only two technical complications. Immediate control of hemorrhage and significant improvement of ascites was obtained in 91.9% and 83.5% of the patients, respectively. Six patients (16.2%) died within a week of TIPS placement due to uncontrollable ascites and multiorgan failure. Four of 31 patients (12.9%) developed mild to moderate grades of hepatic encephalopathy that was controlled with lactulose. Rebleeding from recurrent portal hypertension was noted in 5 of 31 cases (16.1%). Shunt stenosis or occlusion was seen in 7 of 31 cases (22.6%) at an average of 6.3 months following TIPS placement. Six patients underwent OLT within an average of 87 days after TIPS. These results indicate that TIPS appears to be an effective method for treatment of refractory VB and RA, especially for patients who are poor candidates for a surgical shunt or awaiting OLT. However, TIPS may not be considered a definitive solution for all patients with portal hypertension because of its current rate of shunt occlusion or stenosis.

Adult↗