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Biomedical subjects

C K Brown

Publications and source records attributed to C K Brown.

At least 19 recordsLinked to original sources

Survival of patients with localized prostate cancer treated with percutaneous transperineal placement of radioactive gold seeds: stages A2, B, and C.

Between 1984 and 1991, a total of 177 patients with adenocarcinoma of the prostate were treated with transcutaneous, transperineal radioactive gold seeds. Of these 177 patients, 20 were determined to have pelvic lymph node involvement and were excluded from this review. The remaining 157 patients received a median radioactivity dose of 164 mCi with a median follow-up of 48 months. Cancer-specific survival at 5 years was 100% for stage A2 and B1, 90% for stage B2, and 76% for stage C cancer. Covariates of grade, total radioactivity administered, age of the patient, and number of seeds implanted did not influence disease-free survival in a statistically significant manner. Significant complications were observed in two patients. The survival rates of patients treated with 198Au seed implantation for localized cancer are equivalent or better when compared to historical data of patients treated with 125I implantation, external beam radiotherapy, combination radioactive gold seed implantation and external irradiation, and radical prostatectomy. In addition, these comparable survival rates using interstitial 198Au seeds may be achieved with less morbidity.

Actuarial Analysis

Discharge instructions: do illustrations help our patients understand them?

STUDY OBJECTIVE: To determine whether the addition of illustrations to discharge instructions improves patient comprehension. DESIGN: Randomized, blinded, prospective study. A blinded investigator asked a series of questions designed to test the participant's comprehension of the discharge instructions. There were 10 possible correct responses. SETTING: Emergency department of a rural Level I trauma center. PARTICIPANTS: Convenience sample of 101 patients discharged with the diagnosis of laceration. INTERVENTIONS: Patients were randomly assigned to receive discharge instructions with (n = 54) or without (n = 47) illustrations. RESULTS: The median number of correct responses was five. Patients with illustrations were 1.5 times more likely to choose five or more correct responses than those without illustrations (65% versus 43%; P = .033). The effect of illustrations varied by demographic group. Among nonwhites (n = 51), patients with illustrations were more than twice as likely to choose five or more correct responses (P = .032). Among patients with no more than a high school education (n = 71), patients with illustrations were 1.8 times more likely to choose five or more correct responses (P = .038). Among women (n = 48), patients with illustrations were 1.7 times more likely to chose five or more correct responses (P = .006). CONCLUSION: The addition of illustrations to discharge instructions for patients who have sustained lacerations improves patient comprehension. There is a large effect among patients who are nonwhite, female, or have no more than a high school education.

Audiovisual Aids

Conference attendance: do we meet the new residency review committee requirements?

STUDY OBJECTIVES: To characterize the attendance at and presenters of conferences given to emergency medicine residents and to determine the ability of emergency medicine residents to attend conferences while working in the emergency department and on off-service rotations. DESIGN: Descriptive study of an anonymous mail survey. PARTICIPANTS: Residency directors of all approved emergency medicine residency programs in the United States. RESULTS: Seventy-six of 95 questionnaires (80%) were returned. We defined "high attendance" at emergency medicine conferences as a reported average of at least 75% attendance by emergency medicine resident physicians. Fifty percent of respondents reported high attendance. Conversely, 17% of programs reported poor attendance, which we defined as an average attendance by 50% or fewer emergency medicine resident physicians. Forty-eight percent of programs reported that emergency medicine faculty conducted more than 50% of the conferences, and 16% reported that the faculty conducted 25% or fewer conferences. Ninety-six percent of programs allowed residents to attend conferences during off-service rotations. Ninety-two percent of programs relieved residents of clinical responsibilities during scheduled shifts in the emergency department so that they might attend lectures. CONCLUSION: We found that a sizable proportion of programs may not have met the new Residency Review Committee requirements for lecture attendance at the time the guidelines were issued. The vast majority of programs met guidelines for relief of clinical duties, and a large proportion of programs exceeded the requirements for percentage of lectures given by emergency medicine faculty.

Emergency Medicine

Subcuticular sutures and the rate of inflammation in noncontaminated wounds.

STUDY OBJECTIVE: To determine whether buried, absorbable, subcuticular sutures increase the degree of inflammation in noncontaminated wounds. DESIGN: Randomized, blinded, prospective trial. SETTING: Laboratory. PARTICIPANTS: Eleven Sprague-Dawley rats weighing 300 to 325 g. INTERVENTIONS: Four wounds were made on each rat. Two wounds on each were closed with three interrupted buried, absorbable, subcuticular sutures 6-0 polyglactin 910 and running 5-0 nylon skin sutures. The other two wounds were closed with running 5-0 nylon skin sutures alone. RESULTS: Fourteen days after the sutures were placed, the animals were killed, and histologic preparations were made from each wound. Each sample was scored on a scale of 0 to 3 for the presence of inflammatory infiltrates, fibroplasia and capillary proliferation, necrosis, exudates, giant cells, and edema. We determined a total wound score by adding the scores from each category. The mean total wound score was 4.46 +/- 2.92 for those closed with buried, absorbable, subcuticular sutures and 4.91 +/- 2.56 for those closed without buried, absorbable, subcuticular sutures. Using the Wilcoxon rank-sum test, we found no statistically significant difference in mean total wound score of wounds closed with and without buried, absorbable, subcuticular sutures (alpha = .01). The probability of detecting a twofold difference in total wound scores was 60% (beta = .40). CONCLUSION: Buried, absorbable, subcuticular sutures do not significantly increase the degree of inflammation in noncontaminated wounds.

Animals

Physician compliance with advanced cardiac life support guidelines.

STUDY OBJECTIVE: To determine compliance with advanced cardiac life support (ACLS) guidelines among ACLS-certified and non-ACLS-certified physicians. DESIGN: Retrospective review of consecutive cardiac arrests between July 1989 and June 1990, including assessment of the resuscitation leaders' ACLS certification. SETTING AND PARTICIPANTS: All nontraumatic prehospital and hospital cardiac arrests in a rural university hospital. RESULTS: Two hundred seven arrests were studied for a total of 436 rhythms with a maximum of 4 rhythms per arrest. There were 78 resuscitations (36.3%) with return of spontaneous circulation. A total of 2,038 interventions were recorded for all rhythms, with 1,320 (64.8%) compliant with ACLS guidelines compared with 718 (35.2%) deviations. Synchronized cardioversion, calcium chloride and sodium bicarbonate were used with significantly higher noncompliance. Ventricular fibrillation had significantly higher mean rhythm deviation scores, whereas scores were significantly lower for sinus rhythm and stable bradycardia (P < .003). Resuscitations led by ACLS-certified and non-ACLS-certified physicians were compared for mean number of deviations per resuscitation attempt, and no differences were found. Resuscitations with return of spontaneous circulation were compared with unsuccessful resuscitations, and there was no difference between groups in controlled deviation scores. No differences could be found between ACLS-certified and non-ACLS-certified physicians for return of spontaneous circulation and survival-to-discharge rates. CONCLUSION: Despite biannual ACLS training of all medical residents and ICU nurses, noncompliance with ACLS guidelines was noted in 35.2% of treatments. We found no correlation between ACLS certification and ACLS guideline compliance.

Cardiopulmonary Resuscitation

Preservation of peristaltic reflex in hypertrophied ileum of guinea pig.

Chronic obstruction of the guinea pig ileum leads to distension and muscular hypertrophy, but how this affects passive biomechanical and nerve-mediated contractions and clearance known as peristaltic reflex is unclear. Ileum of controls had a diameter of 3.0 +/- 1.1 mm and a circular muscle thickness of 37.2 +/- 11.2 microns; 4 wk after placement of a nonconstricting Gore-Tex band, the ileum was distended to 10.0 +/- 0.19 mm, and its muscle had hypertrophied to 195.0 +/- 61.2 microns. Hypertrophied segments exceeded controls in capacity (e.g., 5.1 +/- 1.1 vs. 1.1 +/0 0.2 ml at 6 cm), compliance, and hysteresis. Threshold volumes and pressures that triggered the reflex were 3.3 +/- 1.3 ml and 3.1 +/- 0.01 mmHg in hypertrophied vs. 0.7 +/- 0.2 ml and 1.5 +/- 0.2 mmHg in controls. The diameter increase that triggered the reflex was 1.4 +/- 0.1 mm in hypertrophied segments and 0.6 +/- 0.1 mm in controls. Hypertrophied segments generated fewer contractions of virtually double the amplitude and failed to generate a pressure differential between up- and downstream sites as controls did. Hypertrophied segments generated larger stroke volumes and cumulative clearance than controls. The ratio of antegrade to retrograde clearance was similar in hypertrophied and control segments. The length of the occluding segment in hypertrophied preparations exceeded that of controls. Control contractions indented the antimesenteric border and propagated antegrade from their site of origin; bizarre writhing movements of hypertrophied segments made their contractions difficult to monitor. Thus distension and muscular hypertrophy do not interfere with the ability of the chronically obstructed guinea pig ileum to generate a peristaltic reflex at least as readily and as powerful and as effective in clearing the lumen as controls.

Animals

Bereavement care.

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Family Practice

Strenuous exercise decreases motility and cross-sectional area of human gastric antrum. A study using ultrasound.

Gastric emptying in humans is delayed with strenuous exercise. We used ultrasound imaging in six healthy volunteers to determine whether changes in motility and configuration of the gastric outlet contribute to this delay. After fasting, all individuals ingested chicken broth and garbanzo beans. With subjects sitting upright, transverse and longitudinal real-time views of the gastric antrum were recorded on video tape. In the exercise studies, subjects pedaled an ergometer for 10 min to attain a heart rate of 85% predicted maximum. On a different day, all subjects had an identical study without exercise. The order of performance of exercise and no-exercise studies was randomized. After exercise, contraction frequencies and antral areas were significantly reduced compared to the studies without exercise. In addition, after exercise there was closure of the pylorus and tubular narrowing of the gastric antrum. Closure of the pylorus and decreased gastric antral area and motility may be important in explaining the decrease in gastric emptying that occurs with strenuous exercise.

Adult

The association of HLA-B8, B51, DR2, and multiple sclerosis in pars planitis.

PURPOSE: To establish a human leukocyte antigen (HLA) association in a homogeneous population of patients with pars planitis. METHODS: A strict set of inclusion parameters was established for the diagnosis of pars planitis. Forty patients with pars planitis who met these criteria underwent HLA analysis of class I and II phenotypes. RESULTS: HLA-B8 was present in 15 (37.5%) of 40 patients versus 85 (19.7%) of 431 controls (relative risk, 2.44; P = 0.011). HLA-B51 was present in 9 (22.5%) of 40 patients versus 51 (11.8%) of 431 controls (relative risk, 2.16; P = 0.049). HLA-DR2 was present in 27 (67.5%) of 40 patients versus 121 (28.0%) of 431 controls (relative risk, 5.32; P < 0.0001). HLA-DR2 has been associated with multiple sclerosis (MS). Exclusion of five patients with pars planitis in whom MS subsequently developed did not change the significance of these findings. CONCLUSIONS: The strongest association of pars planitis with HLA-DR2 and the temporal development of MS in some patients with pars planitis further supports an association between pars planitis and MS.

Case-Control Studies

Long-term speech results of cleft palate patients with primary palatoplasty.

This investigation examined the influence of cleft type, type of surgery, age at surgery, and gender on speech proficiency of 204 patients with cleft palate who required only primary palatoplasty. Speech measures were obtained for each subject from at least three annual examinations between the ages of 4 and 16 years. Neither age at surgery nor type of surgery were discriminating factors. The less extensive cleft type, i.e., soft palate only, was associated with greater rates of change in the performance variables than were the other three cleft types. Females showed greater rate changes than males.

Adolescent

Marine trauma, envenomations, and intoxications.

When humans encounter marine creatures a variety of maladies may occur, ranging from dermatitis to life-threatening trauma, allergy, envenomations, or intoxications. The emergency physician should be prepared to recognize quickly and address appropriately the potential life threats, which are primarily neurologic, respiratory, and cardiovascular. A high degree of suspicion for these illnesses is needed. Intoxications may be especially confusing. Although most of the syndromes are self-limited and treatment supportive, time is of the essence if neuromuscular paralysis, hypotension, or respiratory compromise is present. Much folklore exists regarding detection and prevention of these entities and should be regarded as such. The last several decades have seen a marked increase in our knowledge base regarding these fascinating envenomations and intoxications. Research in the next several decades probably will produce a variety of diagnostic and therapeutic tools, which will further our understanding of, and ability to specifically manage, these syndromes.

Animals

The occupational risk of cytomegalovirus infection among day-care providers.

We prospectively studied day-care providers at six day-care centers in south-eastern Iowa to determine their occupational risk for primary cytomegalovirus infection and to define epidemiologic risk factors. Ninety-six (38%) of 252 day-care providers were seropositive for cytomegalovirus by latex agglutination at entry into the study. Among 82 seronegative providers available for follow-up, seven seroconversions occurred at only two of the six participating centers, yielding an annualized seroconversion rate of 7.9%. Median time to seroconversion among these providers was 13 months. Using Kaplan-Meier estimates of risk, we determined that the overall risk of seroconversion among providers at various centers ranged from 0% to 22% by 12 months and from 0% to 40% by 16 months. Risk of cytomegalovirus acquisition by providers was independent of race, age, education, the presence of a child at home, or caring for children younger than 2 or 3 years in the day-care center. However, the risk of seroconversion among day-care providers appeared to parallel rates of cytomegalovirus excretion and acquisition among children at each center.

Adult

The nature of naturally occurring mutations in the hemagglutinin gene of vaccinia virus and the sequence of immediately adjacent genes.

The expression of the vaccinia IHD-J hemagglutinin (HA) gene is regulated by two promoters, an early/late and a second distinct late promoter. The first promoter results in transcripts that begin early and are synthesized throughout the infection. All transcripts from this promoter initiate at the same 5' site. A second promoter is only active late in infection and initiates transcription some distance upstream of the first promoter. We have previously shown that the transcriptional start site controlled by this second, "late only" promoter lies within the coding sequence of an upstream reading frame (p16-ORF), whereas the termination of early transcription of the HA gene utilizes a transcription termination signal (TTTTTNT) located just beyond the coding region of an immediately downstream reading frame (p17-ORF). In order to assist our understanding of HA gene expression, we report here the sequence of these two ORFs adjacent to the HA gene. The HA-ORF itself consists of 945 bp, whereas the upstream p16-ORF consists of 429 bp and the downstream p17-ORF of 453 bp, sufficient to encode polypeptides of 16 and 17 kD, respectively. While many strains of vaccinia are HA+, rabbitpox virus and the variant of vaccinia IHD-J, designated IHD-W, are HA-. We report and compare here the HA gene sequences of wild-type rabbit poxvirus, two spontaneous HA+ revertants of rabbit poxvirus, and the HA- vaccinia strain IHD-W to that of the previously sequenced (1) prototype HA+ IHD-J strain of vaccinia. All differences were found to occur within the HA open reading frame.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence

Intraosseous transfusion in an anesthetized swine model using 51Cr-labeled autologous red blood cells.

Peripheral venous access can often be difficult to obtain in infants and young children. Landmark articles in the 1940s showed that the intraosseous (IO) route was a viable one for resuscitation. While anecdotal reports and clinical experience suggest that blood products can be transfused via the IO route, it has not been specifically studied nor documented. We performed a prospective study to document the feasibility of red blood cell transfusion via the IO space. We studied the rapid infusion of 51Cr-labeled red blood cells via the IO space through an 18-gauge IO needle in three normovolemic immature swine. Serial central venous samples were removed at 30 seconds and at 1, 5, 15, 30, and 60 minutes and analyzed for evidence of radiolabeling. Our results revealed rapid delivery of radiolabeled red blood cells into the central circulation with no evidence of early heomolysis. Highest counts were seen in samples taken at 30 seconds to 1 minute. We conclude that the IO route is a viable means for blood transfusion in a nonhemorrhagic model.

Animals

Molecular characterization of the vaccinia virus hemagglutinin gene.

The vaccinia virus hemagglutinin (HA) is a glycoprotein found on the plasma membrane of infected cells and the envelope of extracellular virus. Two forms of HA (85 and 68 kDa) are detected by immunoblot analysis. Although hemagglutination activity is only readily detectable late in infection, the 85-kDa HA appears early and accumulates throughout infection, whereas the 68-kDa form appears only late in the cycle. Production of the 68-kDa HA but not the 85-kDa HA was inhibited by either cytosine arabinoside or rifampin. Analysis of HA gene expression reveals a complex pattern of expression. The HA gene is transcribed early to yield a 1.65-kb dicistronic early transcript, consisting of the 945-bp HA open reading frame (ORF) fused to a 453-bp downstream ORF. Transcription from this site initiates 7 bases upstream of the AUG initiating codon of the HA ORF. Due to the discrepancy between the calculated size of the HA protein (33 kDa) and that reported for the unglycosylated HA protein derived from in vitro translation (58 kDa), we placed an early transcription termination signal (TTTTTAT) directly downstream of the 945-bp HA ORF. This led to a reduction in size of the early HA mRNA to 1.2 kb, as expected, but had no effect on the formation of either the 85- or 68-kDa protein. Transcripts originating from the early promoter are found throughout the infection cycle. However, after DNA replication, transcription from a second, late promoter ensues. The transcriptional start site of the late promoter is within a consensus TAAATG sequence located 135 bases upstream of the transcriptional start site of the first promoter. The late transcriptional start site is also found within an upstream ORF.

Amino Acid Sequence

Critical evaluation of the cocaine test in the diagnosis of Horner's syndrome.

We evaluated the effectiveness of the cocaine test for diagnosing Horner's syndrome. The test was administered to 119 patients with a diagnosis of Horner's syndrome and to 50 normal subjects. We compared the cocaine-induced anisocoria in the two groups by measuring photographs of the pupils. We found the cocaine test to be highly effective in separating normal subjects from patients with Horner's syndrome. The chances of having Horner's syndrome increased with the amount of cocaine-induced anisocoria. Through the use of logistic regression analysis, we determined the odds ratio of having Horner's syndrome compared with not having it for each 0.1-mm increment of anisocoria measured after cocaine administration. A postcocaine anisocoria value of 0.8 mm gave a mean odds ratio of approximately 1050:1 that Horner's syndrome was present (lower 95% confidence limit = 37:1). We found that simply measuring the postcocaine anisocoria provided a better prediction of Horner's syndrome than taking the trouble to calculate the net change in anisocoria. Odds ratios should help the clinician decide if the result of a cocaine test is indicative of Horner's syndrome.

Adult

Velar-pharyngeal status in cleft palate patients with expected adenoidal involution.

This study was designed to provide information about whether cleft palate patients with hypertrophied adenoids maintain velar-pharyngeal contact during the time of expected adenoidal atrophy. Thirty-nine subjects were selected from a large longitudinal study on the basis of availability of lateral still x-ray films taken in series from 5 to 16 years of age. Ratings of velar-pharyngeal contact and ratings of adenoid size were obtained from the films. The obtained data indicated the expected decrease in adenoid size but also, for the group, maintenance of velar-pharyngeal contact. However, three of the 39 subjects were judged to show loss of such contact during the period of study, and an additional four had surgery for velopharyngeal incompetence after the completion of the study. All seven appeared to show significant deterioration of velopharyngeal status in middle or late adolescence. Implications of these findings are discussed.

Adenoids