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Biomedical subjects

B Young

Publications and source records attributed to B Young.

At least 19 recordsLinked to original sources
PubMed1992

Interstate differences in incidence and mortality from melanoma. A re-examination of the latitudinal gradient.

OBJECTIVE: To investigate the patterns of cutaneous malignant melanoma (CMM) mortality in Australia. DESIGN: A descriptive analysis of melanoma incidence and mortality in Australia supplemented by a case series analysis of melanoma survival. Melanoma mortality rates were based on tabulations supplied by the Australian Bureau of Statistics for the years 1969-1989. Melanoma incidence rates were based on State cancer registry records for the years 1977-1990. The case series survival analysis was based on detailed individual records from the population-based cancer registries in Tasmania and South Australia. MAIN OUTCOME MEASURES: The level of and rise in melanoma mortality rates during 1969-1989 in Australia; the five-year survival rates for Tasmanian and South Australian cases; and male:female incidence ratios related to latitude. RESULTS: We found annual increases in melanoma mortality rates of 2.5% in men (P < 0.0001) and 1.1% in women (P < 0.0001) for all Australia. The five-year survival rates (with 95% confidence intervals [CI]) were: 67% (59%-75%) for Tasmanian men; 79% (76%-83%) for South Australian men; 80% (74%-86%) for Tasmanian women and 88% (86%-91%) for South Australian women. A change in the male:female incidence ratio with latitude was also found--women have significantly higher incidence rates at higher latitudes, but similar rates to men at lower latitudes. CONCLUSIONS: The age standardised mortality from CMM for the period 1969 to 1989 shows little variation by State for women, despite a considerable range in latitude. CMM mortality in men is increasing at a faster rate than that in women. Between 1982 and 1987 the male:female incidence ratio in high latitudes in the Southern Hemisphere showed an excess of cases in women, a finding which we believe has not been reported before.

Aged↗
PubMed1992

Activation of the alternative complement pathway accompanies disease flares in systemic lupus erythematosus during pregnancy.

OBJECTIVE: To assess the activity of systemic lupus erythematosus (SLE) during pregnancy and to distinguish it from preeclampsia. METHODS: We prospectively measured the complement activation products Ba, Bb, SC5b-9, and C4d, as well as the conventional complement determinants C3, C4, and CH50, during pregnancy in 14 patients with SLE and 10 women with preeclampsia. RESULTS: Four of the 14 SLE patients were considered to have disease flares, 3 occurring in the second trimester and 1 postpartum. In these patients, significant abnormalities of Ba, Bb, SC5b-9, and CH50 were noted. In contrast, measures of C4d did not distinguish between pregnant patients who had flares and those whose SLE remained stable. Although decreased values of C3 were rarely seen in the patients with stable disease, normal values of C3 during lupus pregnancy were not reliably associated with stable disease. Three of 10 non-SLE patients with preeclampsia had elevated levels of Ba; however, in each case, the CH50 level was close to or within the normal range. This was in sharp contrast to the findings observed in the 4 patients with active SLE, in whom high levels of plasma Ba were always associated with low CH50 values. Moreover, the ratio of CH50 to Ba was significantly lower in the patients with lupus flares than in the non-SLE patients with preeclampsia. CONCLUSION: While a decline in the CH50 level alone could otherwise be attributed to decreased synthesis of complement components, these data demonstrate that ongoing activation of the alternative complement pathway can accompany disease flares in pregnant women with SLE.

Complement Activation↗
PubMed1992

Problem-based learning: an effective educational method for a surgery clerkship.

Problem-based learning (PBL) has been implemented during the clinical years in a few medical schools. The purpose of this study is to determine whether PBL provides a better education than traditional methods. Students in the first and third rotations (n = 42) went through the traditional clerkship, which utilized Socratic teaching (SI), while students in the second and fourth rotations (n = 36) were taught by the PBL method. Two performance measures were used to assess clerkship effectiveness. One was a modified essay examination (MEE) administered as part of the departmental evaluation. The other was the NBME-II exam and its surgery subsection NBME-II-S. The MEE was designed to measure six dimensions of the problem-solving process. The NBME-II was utilized to measure knowledge. Unpaired t tests were used to identify statistically significant group differences. The PBL group performed significantly better on two MEE dimensions: (1) differential diagnosis formation (PBL, 92.5 +/- 0.8; SI, 89.1 +/- 0.5; P < 0.01) and (2) interpretation of clinical data (PBL, 93.3 +/- 0.6; SI, 91.6 +/- 0.4; P < 0.03). A third dimension, ordering appropriate lab and diagnostic studies, approached significance (P = 0.057), and the PBL group performed better. On the NBME-II there was not a significant difference between the two groups. However, the trend (P = 0.059) was for the PBL group to score higher on the NBME-II-S (PBL mean: 502 +/- 15; SI mean: 468 +/- 12). When overall achievement was controlled for, the PBL group performed significantly better than the SI group (P = 0.046) on the NBME-II-S.(ABSTRACT TRUNCATED AT 250 WORDS)

Education, Medical↗
PubMed1992

Undergraduate surgical education for the twenty-first century.

This article addresses the problems associated with current undergraduate surgical education and discusses the requirements necessary for its improvement during the third and fourth years of medical school. It asserts that, coincident with the emphasis on faculty research and publication and expanded resident patient care duties, teaching, particularly medical student teaching, has assumed a very low priority. Third-year medical students are attached to surgical teams, where their education is haphazard and disorganized. Furthermore, because any teaching that occurs is teacher oriented rather than student centered, knowledge is accumulated passively and is not well retained. Traditional evaluation using shelf multiple choice examinations and ward ratings by residents and faculty may provide inaccurate assessments of the students' performance. The undergraduate surgical education program should be directed by a faculty member who has been grounded in educational techniques and research and supported by a department chairman committed to bettering the program. In the clerkship, medical students should be assigned to faculty rather than to services and should be presented problems that require solution. Students also should be provided with the resources to solve the problems and should be given sufficient time to solve them. Some operating room experience and bedside teaching should occur during the clerkship. A variety of evaluation and testing methods based on the learning objectives of the clerkship should be used. Third-year students should not be promoted until they have demonstrated their acquisition of appropriate knowledge and skills.(ABSTRACT TRUNCATED AT 250 WORDS)

Education, Medical, Undergraduate↗
PubMed1992

Developing students' cognitive skills in a problem-based surgery clerkship.

In 1989-90, 57 students in a new program for the third-year surgery clerkship at the University of Kentucky College of Medicine participated either in a control group (22 students) receiving a traditional method of instruction (Socratic instruction, SI) or in an experimental group (35 students) taking part in problem-based learning (PBL) sessions. The two groups' performances on six evaluative instruments designed to test either their factual knowledge or their knowledge application (i.e., clinical problem-solving skills) were compared. The measures of factual knowledge were associated with higher scores for the SI group on two quizzes; scores were not significantly different on another quiz and on a cumulative final examination. The measures of knowledge application (administered at the end of the clerkship) were associated with higher scores for the PBL group: scores were significantly higher on a modified essay examination and approached significance on a standardized-patient examination. The authors conclude that their results (1) have important similarities to those of previous research suggesting that a PBL format is essentially equivalent to a traditional curricular format in improving students' factual knowledge and (2) support the hypothesis that PBL is superior in improving clinical problem-solving skills.

Clinical Clerkship↗
PubMed1992

Nutrition and brain injury.

The patient with head injury must overcome central and systemic insults. In addition to the head injury itself, the patient suffers a systemic metabolic response to injury. Both of these insults can affect the patient's ability to survive and recover. During the past decade, investigators have described the systemic metabolic result identified by hypermetabolism, hypercatabolism, the acute-phase response, decreased immunocompetence, hyperglycemia, increased counterregulatory hormone levels, increased ventricular fluid and serum cytokine levels, and altered gastric function. During the next decade, investigators will attempt to modulate this response by manipulating the types of nutrients administered, use of pharmacologic and physiological agents, and administration of growth factors.

Brain Injuries↗
PubMed1991

Mutations in a nonconserved sequence of the Tetrahymena ribozyme increase activity and specificity.

The RNA substrate-binding site of the Tetrahymena ribozyme is connected to the catalytic core by the joining region J1/2. Although J1/2 is not conserved among group I introns, small insertions or deletions in this sequence have dramatic effects, enhancing the turnover number and sequence specificity of ribozyme-catalyzed RNA cleavage. Measurements of rate constants for individual steps in the reaction have revealed the basis of these improvements. Ironically, the higher turnover and specificity both result from decreased affinity for RNA, rather than better cleavage. These results provide evidence that the nonconserved J1/2 sequence positions the RNA substrate to optimize tertiary interactions and ensure cleavage at the position corresponding to the 5' splice site. The wild-type RNA is well adapted to its biological function, and its limitations in multiple turnover can be corrected by mutation.

Animals↗
PubMed1991

Ras mutations in United Kingdom examples of oral malignancies are infrequent.

Point mutations in codons 12, 13 or 61 of the oncogenes Ha-ras, Ki-ras or N-ras have been identified in human malignancies of many types. Using the PCR (polymerase chain reaction) technique for DNA amplification in vitro and stringent probing of the amplified DNA on dot blots with a library of specific oligonucleotides, we have screened for the presence of ras mutations in oral and para-oral malignancies and some associated lesions. The material, from UK patients, consisted of 22 oral squamous-cell carcinomas including 5 neck metastases, 1 oral mucosal dysplasia, 1 proliferative verrucous leukoplakia, 1 antral and 1 tonsillar carcinoma, 1 basal-cell carcinoma, 1 salivary adenocarcinoma, 1 salivary adenoid cystic carcinoma and 1 lung adenocarcinoma metastatic to the gingiva. Genomic DNA was extracted from tissues which were fresh or preserved in liquid nitrogen. Two DNA samples contained point mutations in codon 61 of Ki-ras. One of these mutations was in the lymphocytes infiltrating a retromolar SCC. The other mutation (CAA to CAU; substitution of glutamine by histidine) was in the lung adenocarcinoma metastasis. The absence of ras mutations in the epithelium of primary oral squamous-cell carcinomas is of considerable interest as other work in our Department on Indian cases of oral carcinomas associated with chewing tobacco (quid) revealed that 35% of these had a codon 12, 13 or 61 mutation in Ha-ras. While ras activations arising from point mutations may occur in a high proportion of oral malignancies associated with chewing tobacco (quid), this was not the case in UK oral malignancies, even where tobacco was smoked.

Aged↗
PubMed1991

A student-centered, problem-based surgery clerkship.

In the academic year 1989-90, the department of surgery at one college of medicine revised its third-year clerkship to focus on students' learning decision-making skills and critical thinking (cognitive skills) and acquiring knowledge about surgery. Learning to perform procedures and tasks (psychomotor skills) would be accomplished in the required fourth-year acting internships. Problem-based learning (PBL) was chosen as the clerkship's primary instructional method. Comprehensive student and program evaluation systems were established. The response by faculty and students has been very positive. Students believe that the new clerkship has helped them increase their abilities in resource use, time management, and retention of knowledge. Faculty have noted students' increased eagerness and enthusiasm for learning.

Clinical Clerkship↗
PubMed1991

C-reactive protein: a critical review.

We have reviewed the literature to determine the value of C-reactive protein (CRP) measurements in the diagnosis and management of a wide range of conditions. CRP levels are of value in 6 clinical situations: (a) monitoring the response to antibiotic treatment in patients with known bacterial infections, (b) in obstetric patients with premature rupture of membranes, a rise in CRP can give early warning of intrauterine infections, (c) differentiation between active disease and infections in patients with systemic lupus and ulcerative colitis where the level of response to active disease has been previously established, (d) as a measure of disease activity and response to disease-modifying drugs in rheumatoid arthritis, (e) early detection of complications in postoperative patients, (f) in differentiating between infection and graft-versus-host-disease in bone marrow transplant patients. CRP levels have been used in an attempt to differentiate between bacterial and viral infections in various clinical situations, however the published literature does not support this role.

Acute-Phase Proteins↗
PubMed1991

Altered gastric emptying in the head-injured patient: relationship to feeding intolerance.

Most patients with moderate to severe head injury initially do not tolerate enteral feedings postinjury. This intolerance is more prolonged than that found in patients suffering other types of trauma. The authors prospectively evaluated 12 patients with moderate to severe head injury (Glasgow Coma Scale score between 4 and 10) throughout their hospitalization for liquid gastric emptying as a possible mechanism for intolerance to enteral feeding. During Week 1, the majority of patients displayed a delay in gastric emptying. Patients also displayed an abnormal biphasic response (gastric emptying faster than normal during the early stage but prolonged later). By Week 2, many patients still had delayed and abnormal biphasic responses to gastric emptying. By Week 3, an improvement was observed with the majority of patients exhibiting rapid gastric emptying, but delays and abnormal biphasic responses were still seen. Patients who initially had rapid or normal gastric emptying tolerated full-strength full-rate feedings significantly earlier compared with those who experienced delayed gastric emptying (8.5 +/- 0.5 days vs. 13.7 +/- 3.2 days, p less than 0.001). All patients tolerated full-strength full-rate feedings by Day 16 postinjury (range 7 to 16 days) except the two patients who displayed delayed gastric emptying for prolonged periods of time (mean 25 days). This is the first study to longitudinally evaluate gastric emptying following head injury. The authors suggest that patients with moderate to severe head injury often experience alterations in gastric emptying which may affect their ability to tolerate enteral feedings.

Adolescent↗
PubMed1991

Update on sports nutrition.

Adequate nutrition is vital to peak athletic performance. Insufficient energy and fluids can hinder ability to compete. Physicians and dietitians must emphasize nutrition's importance to athletes. Sports nutrition follows the same principles as good nutrition.

Dietary Carbohydrates↗
PubMed1991

Metabolic management of the patient with head injury.

Patients with severe head injury have a disruption in metabolic homeostasis that includes increased energy expenditure and increased protein catabolism. These changes have been suggested to occur secondary to steroid administration, immobility, and other factors. A review of investigations indicates that the head injury itself causes these metabolic changes, although steroid administration can further alter plasma amino acid changes. Altered plasma amino acid profiles after head injury may have an effect on substrate availability to the brain, bacterial translocation, and overall nitrogen balance. Patients with severe head injury have increased skeletal muscle efflux of amino acids. Lack of nutrient supplementation in these patients is associated with increased morbidity and mortality. Enteral nutrition is the preferred mode of feeding but often is not tolerated in the patient with head injury. Parenteral nutritional support can be given to these patients without worsening cerebral edema.

Amino Acids↗
PubMed1991

Increased plasma and ventricular fluid interleukin-6 levels in patients with head injury.

The cytokine interleukin-6 (IL-6) plays a major role in initiating the acute phase response, especially in the production of acute phase reactants such as C-reactive protein. The objectives of this study were to determine whether plasma or ventricular fluid IL-6 levels were elevated at time of admission after head injury and whether plasma IL-6 levels related temporally to clinical improvement of levels of acute phase reactants. Thirty patients with Glasgow Coma Scale (GCS) scores of 3 through 10 were observed for 15 days after head injury. Peak elevation of plasma IL-6 occurred on admission (85 +/- 12 U/ml; normal level is less than 2 U/ml) and then decreased during the hospital course to a level of 29 +/- 4 U/ml on day 15. Plasma IL-6 levels decreased significantly faster in patients with admission peak 24-hour GCS scores of 8 through 10 compared with patients with GCS score less than 8 (p less than 0.01). Patients had markedly elevated and variable ventricular fluid IL-6 levels on admission (mean 3880 +/- 2022 U/ml; normal, less than 2 U/ml). A temporal relationship was found between plasma IL-6 levels and multiple acute phase reactants thought to be mediated by IL-6. We conclude that plasma and ventricular fluid levels of IL-6 are elevated after head injury and that plasma IL-6 level is temporally related to acute phase reactants and clinical improvement. We suggest that IL-6 may play an etiologic role in many of the metabolic or nutritional sequelae of head injury.

Adolescent↗
PubMed1990

A randomized trial of surgery in the treatment of single metastases to the brain.

To assess the efficacy of surgical resection of brain metastases from extracranial primary cancer, we randomly assigned patients with a single brain metastasis to either surgical removal of the brain tumor followed by radiotherapy (surgical group) or needle biopsy and radiotherapy (radiation group). Forty-eight patients (25 in the surgical group and 23 in the radiation group) formed the study group; 6 other patients (11 percent) were excluded from the study because on biopsy their lesions proved to be either second primary tumors or inflammatory or infectious processes. Recurrence at the site of the original metastasis was less frequent in the surgical group than in the radiation group (5 of 25 [20 percent] vs. 12 of 23 [52 percent]; P less than 0.02). The overall length of survival was significantly longer in the surgical group (median, 40 weeks vs. 15 weeks in the radiation group; P less than 0.01), and the patients treated with surgery remained functionally independent longer (median, 38 weeks vs. 8 weeks in the radiation group; P less than 0.005). We conclude that patients with cancer and a single metastasis to the brain who receive treatment with surgical resection plus radiotherapy live longer, have fewer recurrences of cancer in the brain, and have a better quality of life than similar patients treated with radiotherapy alone.

Adult↗