Patterns of verbal learning and memory in traumatic brain injury

CVLT and WMS-R Digit Span variables were used to calculate indexes of seven specific short- and long-term memory processes: working memory span and central executive functions, and long-term memory encoding, consolidation, retention, retrieval, control abilities. Scores on these indexes were then cluster-analyzed to determine whether subtypes of memory performance exist that correspond to deficits in these theoretical memory constructs. Parallel analyses were conducted with two large samples (N = 150 and N = 151) of individuals who had sustained a traumatic brain injury (TBI). Findings showed that TBI results in subgroups of memory disorders with specific deficits in consolidation, retention, and retrieval processes. Control problems (keeping track of list versus non-list items) only appeared in conjunction with retrieval deficits. Working memory span and central executive functioning (i.e., the ability to manipulate information in working memory) do not appear to be deficits characteristic of TBI as no such clusters emerged in the analyses. By using specific indexes of memory processes, and in contrast to previous studies, patterns of memory dysfunction were found that correspond to deficits in theoretically meaningful memory constructs.

Low birth weight and reduced renal volume in Aboriginal children

Low birth weight predisposes to renal disease in Aboriginal adults. This could be due to reduced nephron numbers, which might be reflected in lower kidney volumes, at least early in life. In this study we evaluated the association of birth weight with renal volume in 174 children and in adolescents 5 to 18 years old in an Aboriginal community with high rates of renal disease. Their mean birth weight was 2.9 kg, and 19% had been low birth weight (<2.5 kg). Kidney dimensions were measured by ultrasound by a single observer, and kidney volume (KV) was calculated from the formula KV (mL) = length x (depth 1 + depth 2)/2 x 0.523. Combined kidney volume, corrected for body surface area (corrKV), was independent of age and averaged 240 +/- 45 mL/1.73 m(2). The average corrKV was significantly lower (by about 20 mL) in low birth weight children than in those with "normal" birth weight. There was a difference of 32 mL in combined corrKV between children in the lowest versus the highest quintile of birth weight. Disparities in calculated kidney volume were driven more by lower kidney depth than length in low birth weight children. We conclude that low birth weight children have lower renal volumes than children of higher birth weights, after correction for current body size. This conclusion is compatible with the theory that intrauterine growth retardation is associated with reduced nephron endowment. The susceptibility to renal disease associated with low birth weight in this population might be mediated in part through this mechanism.

A novel serine protease inhibition motif involving a multi-centered short hydrogen bonding network at the active site

We describe a new serine protease inhibition motif in which binding is mediated by a cluster of very short hydrogen bonds (<2.3 A) at the active site. This protease-inhibitor binding paradigm is observed at high resolution in a large set of crystal structures of trypsin, thrombin, and urokinase-type plasminogen activator (uPA) bound with a series of small molecule inhibitors (2-(2-phenol)indoles and 2-(2-phenol)benzimidazoles). In each complex there are eight enzyme-inhibitor or enzyme-water-inhibitor hydrogen bonds at the active site, three of which are very short. These short hydrogen bonds connect a triangle of oxygen atoms comprising O(gamma)(Ser195), a water molecule co-bound in the oxyanion hole (H(2)O(oxy)), and the phenolate oxygen atom of the inhibitor (O6'). Two of the other hydrogen bonds between the inhibitor and active site of the trypsin and uPA complexes become short in the thrombin counterparts, extending the three-centered short hydrogen-bonding array into a tetrahedral array of atoms (three oxygen and one nitrogen) involved in short hydrogen bonds. In the uPA complexes, the extensive hydrogen-bonding interactions at the active site prevent the inhibitor S1 amidine from forming direct hydrogen bonds with Asp189 because the S1 site is deeper in uPA than in trypsin or thrombin. Ionization equilibria at the active site associated with inhibitor binding are probed through determination and comparison of structures over a wide range of pH (3.5 to 11.4) of thrombin complexes and of trypsin complexes in three different crystal forms. The high-pH trypsin-inhibitor structures suggest that His57 is protonated at pH values as high as 9.5. The pH-dependent inhibition of trypsin, thrombin, uPA and factor Xa by 2-(2-phenol)benzimidazole analogs in which the pK(a) of the phenol group is modulated is shown to be consistent with a binding process involving ionization of both the inhibitor and the enzyme. These data further suggest that the pK(a) of His57 of each protease in the unbound state in solution is about the same, approximately 6.8. By comparing inhibition constants (K(i) values), inhibitor solubilities, inhibitor conformational energies and corresponding structures of short and normal hydrogen bond-mediated complexes, we have estimated the contribution of the short hydrogen bond networks to inhibitor affinity ( approximately 1.7 kcal/mol). The structures and K(i) values associated with the short hydrogen-bonding motif are compared with those corresponding to an alternate, Zn(2+)-mediated inhibition motif at the active site. Structural differences among apo-enzymes, enzyme-inhibitor and enzyme-inhibitor-Zn(2+) complexes are discussed in the context of affinity determinants, selectivity development, and structure-based inhibitor design.

Relative distribution of tumour cells and reactive cells in follicular lymphoma

Follicular lymphoma is the most common low-grade B-cell lymphoma. It is characterized by at least a partial follicular growth pattern in the majority of cases, by the morphological resemblance of the tumour cells to follicle centre centroblasts and centrocytes, and by the distinctive expression of Bcl-2 protein as a consequence of a translocation between chromosomes 14 and 18, resulting in the juxtaposition of Bcl-2 and the immunoglobulin heavy chain locus. It is not known whether the follicular growth pattern of follicular lymphoma is a consequence of properties of the tumour cells, or whether the tumour cells invade and gradually occupy a niche generated by a normal T-cell-dependent B-cell response. This study has identified cases of follicular lymphoma in which the tumour cells are apparent within a normal reactive germinal centre background. The reactive background has been investigated in these cases and also in cases showing a more characteristic appearance, in which entire malignant follicles appear to be Bcl-2-positive, as assessed by microdissection and analysis of clonality by the polymerase chain reaction (PCR). A reactive oligoclonal background was observed in all cases studied, characteristic of a normal follicle centre response. These data suggest that the progression of follicular lymphoma is dependent on the normal germinal centre microenvironment. Disruption of this dependence might be considered as a novel therapeutic strategy.

" 'Just think of TB and Asians', that's all I ever hear": medical learners' views about training to work in an ethnically diverse society

The case for being able to respond effectively to cultural and ethnic diversity in health care is attracting increasing debate in medical education. However research exploring the perspectives of learners is lacking.

AIMS

We sought medical learners' perceptions and their perceived training needs in relation to cultural and ethnic diversity in health care.

METHODS

A series of nine focus group interviews was conducted with 55 medical learners, including undergraduate students in a UK medical school and a group of postgraduate general practitioners in training. Interview data were analysed using qualitative methods.

RESULTS

Participants had a broad but superficial awareness of multicultural issues. This focused upon "difference" with students emphasizing their need to acquire knowledge of different beliefs and practices. Current teaching was perceived as inadequate and limited largely to ethnic patterns of disease. Most felt a need for greater training. They regarded development of particular communication skills, such as working with interpreters as helpful. Beyond avoiding stereotyping, learners rarely identified reflecting upon their attitudes or the issue of racism as important. Students anticipated a range of potential problems for further training, but sought learning that was relevant, practically oriented and stimulating.

CONCLUSIONS

The study points to learners' experience of inadequate training but suggests a willingness to learn more. The possible predominance of a "difference" perspective might drive a narrow focus upon learning cultural knowledge at the expense of promoting a balance with self-reflection upon attitudes and developing generic skills. Educators might heed learners' views about how they should be taught successfully.

Wrestling with ethnic diversity: toward empowering health educators

The importance of training health professionals for work in an ethnically diverse society is increasingly recognized. However, health educators may lack confidence or experience in delivering such teaching, contributing to a self-perpetuating inertia.

OBJECTIVES

To identify current experience and challenges perceived by educators of different health professionals, and to facilitate and debate the development of teaching in this field.

METHODS

Educators (n=61) from 42 different organizations, participated in facilitated workshops in three different UK settings. They included clinician teachers of medical undergraduates and postgraduates, and educators of nurses, primary care and hospital physicians, physiotherapists, occupational therapists and paramedical staff. Opportunities were provided for educators to discuss experiences; to participate as "learners" in examples of interactive training exercises; to anticipate challenges they might encounter in developing and providing training themselves; and to discuss ways of negotiating them. Qualitative data generated from the workshops were analysed for common themes.

RESULTS

Participants had received little relevant training themselves. For many, the workshops provided a first formal opportunity to consider their own responses to ethnic diversity in health care. Current provision of such training in their institutions was limited. Educators lacked specific training to facilitate the learning of others in this field. They wrestled with a wide range of issues: from critical dilemmas about the philosophy of teaching, through to the practicalities and personal challenges of face to face teaching. Strategies to address these were generated that may merit consideration.

CONCLUSION

Educators will need help to overcome their uncertainty in approaching this topic and be empowered to develop training. Developing teachers' own awareness and skills, followed by appropriate support, are likely to be prerequisites for successful training.

Physician intervention and patient risk perception among smokers with acute respiratory illness in the emergency department

BACKGROUND

Acute Respiratory Illness accounts for over 12 million visits to emergency departments in the United States each year. Between one-fourth and one-half of these patients are smokers. We examined the frequency of physician intervention for smoking cessation among acute respiratory illness patients in the emergency department, and examined the influence of physician intervention on patients' perceived risk from smoking and motivation to quit.

METHODS

This study was conducted in the emergency department of a large inner-city hospital. Adult smokers (n = 63) presenting with symptoms of acute respiratory illness were surveyed by exit interview while in the emergency department. The frequency and extent of physician interventions for smoking were examined using the Agency for Health Care Policy and Research guidelines as a model. We also assessed patients' perceptions of risk from smoking, the presence of other household smokers, and the patients' motivation to quit.

RESULTS

Emergency department physicians provided incomplete and inconsistent intervention for smoking. While most patients reported being asked if they smoked, only half of smokers were advised to quit. Only 9% were offered any assistance with quitting. Risk perception was generally low, however, the majority of smokers were willing to receive on-site smoking cessation counseling while in the emergency department.

CONCLUSIONS

The small sample size in this study requires that results be interpreted with caution. However, the findings of this study suggest that the emergency department setting may provide a unique "teachable moment" in which to initiate smoking cessation counseling for this high-risk population.

Somatic hypermutation and B-cell lymphoma

During the B-cell response to T-cell-dependent antigens, the B cells undergo a rapid proliferative phase in the germinal centre. This is accompanied by the introduction of mutations into the immunoglobulin (Ig) variable region (V) genes. The B cells are then selected according to the affinity of the encoded immunoglobulin for antigen, resulting in affinity maturation of the response. Analysis of mutations in IgV genes has given insight into the history of individual B cells and their malignancies. In most cases, analysis of mutations confirms classifications of B-cell lineage designated by studies of cellular morphology and surface antigen expression. However, of particular interest is the subdivision of groups of malignancies by analysis of somatic hypermutation. It is now apparent that there are two subsets of chronic lymphocytic leukaemia (CLL), one with a low load of mutations and poor prognosis. and one with a heavy load of mutations with a much more favourable prognosis. In addition, in Burkitt's lymphoma, sporadic and endemic subtypes are now considered possibly to have a different pathogenesis, reflected in differences in the numbers of mutations. Hodgkin's disease, which was a mystery for many years, has now been shown to be a B-cell tumour. Although in many cases the Ig genes are crippled by somatic hypermutation, it is thought that failure to express Ig is more likely to be associated with problems of transcription. It has been proposed that the distribution of mutations in a B-cell lymphoma can be used to determine whether a lymphoma is selected. We have investigated the load and distribution of mutations in one group of lymphomas--marginal zone B-cell lymphomas of mucosa-associated lymphoid tissues (MALT-type lymphoma), which are dependent on Helicobacter pylori for disease progression, to investigate the limits of information that can be derived from such studies. Comparison of the load of mutations demonstrates that these tumours have approximately the same load of mutations as normal mucosal marginal zone B cells from the Peyer's patches and mucosal plasma cells. This is consistent with the origin of these cells from mucosal marginal zone B cells with plasma cell differentiation. To investigate selection in MALT lymphomas we compared a region of the framework region three in ten MALT lymphomas which use the V(H4) family, with the same codons in groups of V(H4) genes that are out of frame between V and J. The latter accumulate mutations but are not used and are not selected. A group of V(H4) genes are in-frame between V and J were also included for comparison. There were no obvious differences in the distribution of mutations between the groups of genes; the same hot spots and cold spots were apparent in each. In the MALT lymphomas, selection was apparent in the framework regions only and the tendency was to conserve. We therefore feel that there is selection to conserve antibody structure and that this does not reflect selection for antigen. We do not believe that antigen selection can be deduced reliably from sequence information alone. It is possible that somatic hypermutation could be a cause of malignancy since it has been shown that the process may generate DNA strand breaks and is known to be able to generate insertions and deletions. Such events may mediate the translocation of genes--a process that is pivotal in the evolution of many lymphomas.

Using real patients in problem-based learning: students' comments on the value of using real, as opposed to paper cases, in a problem-based learning module in general practice

OBJECTIVES

To explore the feasibility and value of using real patients as trigger material in problem-based learning (PBL).

DESIGN

A questionnaire was given to all students participating in a PBL module including a question about 'the added value of using real, as opposed to paper cases', in problem-based learning. Resources used by students and assessment of feasibility were recorded by the course tutors.

SETTING

A 7-week student-selected problem-based module in general practice in the fourth-year undergraduate medical curriculum, University of Newcastle upon Tyne.

SUBJECTS

69 students participating in the module over 2 years.

RESULTS

All students valued the use of real patients. A total of 10 categories were identified, all congruent with accepted educational principles for effective adult learning. Real patients stimulated the use of a very wide range of resources and imaginative presentation of what had been learned.

CONCLUSION

Real patients are potent trigger stimuli in problem-based learning. The use of real patients in this general practice-based module presented no organizational or ethical difficulties. Their use should be considered more widely.

Ligation of alpha4ss1 integrin on human intestinal mucosal mesenchymal cells selectively Up-regulates membrane type-1 matrix metalloproteinase and confers a migratory phenotype

Human intestinal lamina propria mesenchymal cells show high surface expression of the alpha4ss1 integrin. Ligation of alpha4ss1 on mesenchymal cell lines with an activating monoclonal anti-alpha4 antibody or vascular cell adhesion molecule-immunoglobulin (VCAM-IgG) leads to the appearance of activated forms of gelatinase A in culture supernatants, and the de novo expression of activated membrane type-1-matrix metalloproteinase (MT1-MMP). In functional assays, signaling through alpha4ss1 results in an increased capacity of mesenchymal cells to migrate through an artificial extracellular matrix, an effect inhibitable by excess tissue inhibitor of metalloproteinase-2. In organ cultures of human intestine, VCAM-IgG also up-regulates MT1-MMP, and in mucosal ulcers of inflammatory bowel disease patients, MT1-MMP transcripts are abundant, coincident with expression of VCAM-1 on cells at the ulcer margin. Collectively these results suggest that alpha4ss1-induced up-regulation of MT1-MMP may be a crucial factor in the migration of mesenchymal cells into ulcer beds during restitution of diseased gut mucosa.

Clarifying the concepts of confidence and competence to produce appropriate self-evaluation measurement scales

INTRODUCTION

This paper reviews the literature on self-evaluation and discusses the findings of a small-scale qualitative study which explored the terms 'confidence' and 'competence' as useful measures in a self-evaluation scale. Four pre-registration house officers took part in interviews and completed a provisional instrument to assess their perceived competence.

FINDINGS

Competence and confidence are useful terms for house officers expressing beliefs about their ability to perform their job but the terms should not be used synonymously. In our study, 'competent' represented what individuals knew about their ability and was based on the individual's previous experience of the task. 'Confident' described a judgement which influenced whether an individual was willing or not to undertake an activity. Confidence was not necessarily based on known levels of competence and therefore performance of tasks which were unfamiliar to the house officer also involved the assessment of risk. The authors give examples of task and skill scales which may be useful in the process of self-evaluation by pre-registration house officers.

CONCLUSIONS

The authors suggest that the process of assessing oneself is complicated, and by its very nature can never be objective or free from the beliefs and values individuals hold about themselves. Therefore self-evaluation instruments are best used to help individuals analyse their work practices and to promote reflection on performance. They should not be used to judge the 'accuracy' of the individual's evaluation.

Patient-oriented learning: a review of the role of the patient in the education of medical students

AIM

To explore the contribution patients can make to medical education from both theoretical and empirical perspectives, to describe a framework for reviewing and monitoring patient involvement in specific educational situations and to generate suggestions for further research.

METHODS

Literature review.

RESULTS

Direct contact with patients can be seen to play a crucial role in the development of clinical reasoning, communication skills, professional attitudes and empathy. It also motivates through promoting relevance and providing context. Few studies have explored this area, including effects on the patients themselves, although there are examples of good practice in promoting more active participation.

CONCLUSION

The Cambridge framework is a tool for evaluating the involvement of patients in the educational process, which could be used by curriculum planners and teachers to review and monitor the extent to which patients are actively involved. Areas for further research include looking at the 'added value' of using real, as opposed to simulated, patients; more work on outcomes for patients (other than satisfaction); the role of real patients in assessment; and the strengths and weaknesses of different models of patient involvement.

Sequence analysis of light chain genes from human intestinal plasma cells demonstrates that lambda genes are almost all in-frame and highly mutated and most kappa genes are highly mutated when in-frame and minimally mutated when out-of-frame

Around 80 % of immunoglobulin (Ig)-producing cells in man are located in the gut, with a preponderance of IgA- and IgM-producing cells that express heavily mutated IgVH genes. Here we describe the characteristics of Ig light chain genes isolated from human ileal and colonic lamina propria plasma cells. We focused on the properties of the two most commonly used light chain families, Vkappa1 and Vlambda2. Out-of-frame lambda rearrangements were very rare, suggesting that these lambda light chains may have undergone sequential rearrangements until successful conformation was achieved. This has not been observed in the human peripheral B cell population. The in-frame lambda gene rearrangements were highly mutated, with a frequency of mutation that was indistinguishable from that observed in many groups of heavy chain variable regions used by intestinal plasma cells. The in-frame kappac chain rearrangements were also highly mutated, but contained a subgroup of genes (27.3 %) that showed over 98 % homology with the germ-line gene. The majority of unused kappa chain genes were unmutated. A strong tendency for preferential mutation of G over C nucleotides was observed. Detailed analysis of the sequences in which the biases were observed suggested that this was likely to be due to selection, rather than a characteristic of the mechanism introducing the mutations.

Practice development in cancer care: self-help for men with testicular cancer

This article describes a joint initiative between health professionals and men who had had testicular cancer to set up a self-help group. The aims of this group were, and still are, to provide information and support and to instigate professional education.

Motion processing in autism: evidence for a dorsal stream deficiency

We report that motion coherence thresholds in children with autism are significantly higher than in matched controls. No corresponding difference in form coherence thresholds was found. We interpret this as a specific deficit in dorsal stream function in autism. To examine the possibility of a neural basis for the perceptual and motor related abnormalities frequently cited in autism we tested 23 children diagnosed with autistic disorder, on two tasks specific to dorsal and ventral cortical stream functions. The results provide evidence that autistic individuals have a specific impairment in dorsal stream functioning. We conclude that autism may have common features with other developmental disorders and with early stages of normal development, perhaps reflecting a greater vulnerability of the dorsal system.