Evaluating problem-based learning in a multilingual student population

OBJECTIVES: The University of Natal Medical School in South Africa provides training for a student body composed of two groups: one with English as a first language and the other with an African language as a first language and English as the second. A new methodology was developed to evaluate an innovative course using modified problem-based learning techniques in this heterogeneous environment. DESIGN: The learning model proposed required achieving a balance of three components: content, enquiry/learning process and social interaction/group process. A multidimensional system, felt to be consistent with this educational philosophy, was developed using seven different quantitative and qualitative techniques. SETTING: The University of Natal Medical School. SUBJECTS: First-year multilingual medical students. RESULTS: The results revealed that social interaction was highly successful in reducing barriers between the student groups and between students and facilitators. However, the emphasis on group participation may have overshadowed the enquiry process, leading to superficial discussions of problems and feelings of repetitiveness. During the course students and facilitators expressed concern that the innovative assessments used did not assess the course content adequately. While the group presentations and projects were useful exercises for consolidation and group interaction, they did not enable facilitators to identify struggling students. CONCLUSIONS: The outcome of the evaluation stressed the need of achieving an appropriate balance both in the curriculum and assessments of the three components of the learning model, particularly in a setting where student backgrounds and language ability differ. Multidimensional methodology is needed for effective evaluation that promotes critical reflection.     

Prevalence and clinical relevance of Blastocystis hominis in diverse patient cohorts

The pathogenicity of Blastocystis hominis is extensively debated in the medical literature. Therefore, we did a prevalence study to investigate the association between the presence of several intestinal parasites and gastrointestinal symptoms in diverse patient cohorts. The study population consisted of 1216 adults, including immunocompromised patients, institutionalized psychiatric or elder subjects, immigrants from developing countries, travellers to developing tropical countries and controls. Several variables for each risk group were considered. Stools specimens, collected in triplicate, were processed by the same technicians. Clinical data about each subject were provided by standardized questionnaires. The presence of gastrointestinal symptoms were related to the presence of any parasite. In addition, on the basis of microbiological results, five subgroups of subjects were evaluated. The results showed a high prevalence of parasites in all the risk groups. Immunocompromised status, recent arrival from developing countries and the presence of behavioural aberrations were significantly related to presence of parasites. B. hominis was the parasite most frequently detected in each studied group. B. hominis showed a significant correlation with gastrointestinal symptoms only when detected in the group including subjects with a severe immunodepression. Immunodepression seems to be a factor of primary importance of the pathogenic role of B. hominis.     

Serosurvey of wild rodents for Rickettsioses (spotted fever, murine typhus and Q fever) in Java Island, Indonesia

The prevalence of antibodies against spotted fever group rickettsia (SFGR), murine typhus and Q fever were investigated in wild rats captured in Indonesia. Sera of 327 rats were collected from Jakarta and Boyolali on Java Island. The prevalences of antibodies against SFGR and murine typhus were 128 (39.1%) and 48 (14.7%), respectively. Antibodies against Q fever were not detected in these serum samples. Antibodies against SFGR were found in all species of rats (20.8–51.9%). The antibody positive rate against murine typhus in Rattus norvegicus (38.0%) was significantly higher than that in other rat species (0–4.8%, p < 0.01). The antibody positive rates against SFGR and murine typhus in rats captured in Jakarta were significantly higher than those in rats captured in Boyolali (p < 0.01). In this survey, all species of rats had antibodies against SFGR, indicating that the 4 species of tested rats (R. norvegicus, R. rattus, R. exulans, R. tiomanicus) were infected with SFGR and that SFGR may infest the whole of Java Island. Most of the rats that were antibody-positive against murine typhus were captured in Jakarta. Therefore, R. norvegicus and R. rattus are likely to be important hosts of murine typhus in Jakarta. The antibody-positive rates against SFGR and murine typhus in rats captured in the dry season were significantly higher than those in rats captured in the rainy season. This may coincide with the active periods of ticks and fleas in Indonesia.     

Blutgruppenantigenexpression in papillären karzinomen der schilddrüse Eine immunhistochemische und klinische studie über das Vorkommen von Lewis-, AB0- und verwandten antigenen

Zusammenfassung In einer immunhistochemischen Arbeit wurden 104 papilläre Schilddrüsenkarzinome auf das Vorkommen von Blutgruppenantigenen des AB0- und Lewis-Systems sowie verwandter, tumorassoziierter Antigene mit Typ-1- und Typ-2-Grundstruktur untersucht. Folgende Strukturen wurden im Gewebe nachgewiesen: CA-50 (sialinierter Typ-1-Vorläufer), CA-19-9 (Sialyl-Le^a), Le^a, Le^b, A, B, H, Le^x, Sialyl-Le^x und Le^y. Während gesundes, adultes Schilddrüsengewebe keine Blutgruppenantigene exprimierte, waren die papillären Karzinome durch die progressive Expression dieser Strukturen gekennzeichnet. Die meisten Tumoren reagierten mit dem C-50-Antikörper (84%), während deutlich weniger Gewebe das CA-19-9-Antigen aufwiesen (38%). Die Typ-2-Strukturen Le^x (47%) und Le^y (13%) wurden deutlich seltener gefunden als die korrespondierenden Typ-1-Antigene Le^a (71%) und Le^b (62%). Die Vorbehandlung mit Neuraminidase verstärkte die Le^a- und Le^x-Färbeergebnisse in 27 bzw. 44 Fällen. Von den A-, B-, und H-Antigenen wurden die A-Determinanten am häufigsten nachgewiesen (24%). In vergleichenden Untersuchungen von Serienschnitten der gleichen Tumoren wurde eine Koexpression mehrerer Typ-1-Antigene im denselben Tumorarealen festgestellt. Karzinome mit Expression von Typ-1- und Typ-2-Strukturen wiesen häufig eine komplementäre Antigenexpression in verschiedenen Bereichen der Gewebe auf. Einige Tumoren exprimierten Typ-1- und Typ-2-Strukturen auch in den gleichen Zellen, jedoch in verschiedenen Bereichen der jeweiligen Zellen.In 68 Fällen wurde eine Follow-up-Untersuchung durchgeführt. Die Beobachtungszeiträume lagen zwischen 12 und 217 Monaten. In 13 Fällen rezidivierte der Tumor, 7 dieser Patienten verstarben an dem Tumorleiden. Die meisten Rezidive traten bei Patienten auf, deren Tumoren die Grenzen des Organs überschritten hatten (pT4, n=19), während keines der pT1-Karzinome (n=20) zu einem Rezidiv geführt hatte. Während Lymphknotenmetastasen in 39 Fällen auftraten, wiesen 6 Patienten Fernmetastasen auf. Die klinischen Ergebnisse wurden mit den Färbeergebnissen korreliert. Es bestand kein Zusammenhang zwischen Antigenexpression und Tumordifferenzierung. Die pT4-Tumoren zeigten eine signifikant stärkere Expression der CA-50-, CA-19-9-, Le^a und Sialyl-Le^x-Strukturen. Karzinome mit Le^y-Expression wiesen signifikant häufiger Metastasen auf. Le^y, H-Typ-1 und H-Typ-2 traten häufiger in rezidivierenden Tumoren auf. Im Gegensatz dazu waren alle Patienten, deren Karzinom das A-Antigen exprimierte, fernmetastasen- und rezidivfrei (n=14). In der multiplen Regressionsanalyse wies der Faktor Fernmetastasierung die größte prognostische Relevanz auf, während im Vergleich dazu die Färbeergebnisse statistisch von untergeordneter Bedeutung waren.

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Blood group antigen expression in papillary carcinoma of the thyroid — An immunohistochemical and clinical study on the occurrence of Lewis-, AB0, and derived antigens

Nine monoclonal antibodies, lectin from Ulex europaeus and neuraminidase enzyme were employed to demonstrate the occurrence of type 1 and type 2 blood group antigens in 104 cases of papillary carcinoma of the thyroid. The reagents applied, recognize the following blood group related antigens: CA-50 (sialylated type 1 precursor), CA-19-9 (sialylated Le^a), Le^a, Le^b, A, B, H, Le^x, sialylated Le^x, and Le^y.Immunohistochemical studies revealed that papillary carcinoma of the thyroid, in contrast to histologically normal thyroid tissue, is characterised by a progressive expression of blood group antigens. Most tumours (84%) reacted with C-50 antibody, whereas only a minority of the tissues demonstrated the CA-19-9 antigen (38%). Type 2 structures Le^x (47%) and Le^y (13%) were found less often than their corresponding type 1 isomers Le^a (71%) and Le^b (62%). Desialylation with neuraminidase increased the Le^a and Le^x staining intensity in 27 and 44 cases, respectively. of the A, B, H antigens the A determinants encountered most frequently (24%).Comparative examinations of sequential sections of the same tumour revealed coexpression of type 1 antigens in the same areas. In carcinomas showing type 1 and type 2 antigen reactivity, a complementary distribution of the structures in different tumour areas was often demonstrated. Some tumours presented combined type 1 and type 2 antigen expression in the same cells, however, in distinct areas within the cell.A follow-up examination was carried out in 68 of the 104 cases. The observation time ranged from 12 to 217 months. Thirteen patients suffered from recurrence, of which 7 died. While lymphatic metastases occurred in 39 tumours, distant metastases were detected in 6 patients. Most of the recurrences were found in patients with tumour classification pT4 (n=19), whereas none of the pT1 carcinomas (n=20) showed recurrence.The clinical results were compared to the blood group antigen expression results. There was no correlation between antigen expression and differentiation degree of the tumour. The pT4 tumours showed a significant higher expression of the CA-50, CA-19-9, Le^a and Sialyl Le^x structures. Carcinomas expressing the Le^y antigen were associated with a significant higher level of metastasizing capacity. The Le^y, H type 1 and H type 2 antigens occurred more frequently in recurrent tumours (n=14). In contrast, none of the patients whose carcinomas expressed the Aantigens (n=14) suffered from a recurrence or hematogenous metastasis.Multiple stepwise regression analysis was carried out to check the importance of each staining and clinical factor. In this analysis, distant metastasis was the most important parameter, whereas the staining results were of minor statistical importance.

     

The therapist's use of self and cultures in children's psychotherapy groups

This paper presents a model for understanding decisions that a therapist makes concerning the use of the self as a therapeutic tool in children's psychotherapy groups. The parameters within which a therapist uses self is directly related to the development of the group's culture. It is proposed that two complementary cultures develop within children's groups, one, indigenous peer culture, strictly of the children's making and the other, therapeutic group culture, created by the therapist in collaboration with group members. Having taken the time to learn a group's indigenous peer culture the therapist can use its metaphors to speak to the children in their own language; eventually it will be possible to engage them in collaboratively building a meaning system which is uniquely designed to address their psychotherapeutic needs. Initially, when indigenous peer culture is predominant, the therapist uses self more receptively in order to connect with the children through empathic immersion, holding intolerable affects and developmental time travel; as treatment progresses and a therapeutic group culture is slowly constructed, the therapist may use him/her self for more change directed interventions through role modeling, confrontation and self disclosure.Chief Psychologist and Coordinator, Children's Clinical Services, Brookline Community Mental Health Center and Instructor, Psychiatry (Psychology), Harvard Medical School and private practice in Brookline and Newton Massachusetts.     

Psychoeducational groups to teach children sexual abuse prevention skills

A series of studies on sexual abuse prevention are presented to highlight important clinical and research issues. In a multi-modal evaluation conducted by the author, elementary children who participated in three group sessions using the Feeling Yes, Feeling No prevention program increased significantly in knowledge and the ability to discriminate unsafe from safe situations. Gains were maintained over a one-year follow-up period. Approximately 5% of the children disclosed sexually abusive experiences. Participating children also exhibited no more anxiety or behavior problems after the program than control children. A second study evaluated the relative efficacy of prevention programs for children conducted by teachers vs. expert consultants. Children in each trainer condition demonstrated equivalent knowledge gains and made equivalent numbers of disclosures. Clinical research by other authors is reviewed to highlight important issues in prevention groups with preschoolers and adolescents, the impact of prevention education on feelings about sexuality, and behavioral effects of prevention programs. Finally, the incorporation of prevention education into psychotherapeutic groups for child victims is discussed.     

Experimental vaccinia virus meningoencephalitis in adult albino mice: Virological,light microscopic and ultrastructural studies

Summary Adult NMRI mice were inoculated intracerebrally with 1.5–5×10² pfu of the neurovirulent strain Ma1 of vaccinia virus. The animals usually became diseased on day 3 and died on day 5 or 6 p.i. Infectivity assay studies on the mouse brains yielded a steeply rising viral titer comparable with that exhibited by several other so-called neurovaccinia strains after intracerebral inoculation. Histological studies revealed a patchy leptomeningitis most apparent over the basal brain surface. Mononuclear elements of varied size were the most common infiltrate cells in the meningitic lesions. These often showed a pronounced hemorrhagic and necrotizing character. In some places, the cellular infiltrates within the subarachnoid space extended along the perforating vessels into the superficial cerebral cortex. By electron microscopy, all essential stages of virus morphogenesis including the discharge of mature virions could be seen in numerous mononuclear phagocytes and adventitial cells. In contrast to this, no unequivocal neuroectodermal cell showed morphologic evidence of productive viral infection. Likewise, no endothelia or vascular myocytes were encountered which contained newly formed virus particles. However, alterations of the walls of blood vessels and signs of disturbed vascular permeability were a frequent finding in the meningeal foci of inflammation as well as in and around the track left by the inoculating needle. Another ultrastructural feature of the meningitic lesions was the widespread occurrence of degenerating or disintegrating infiltrate cells both infected and uninfected ones.The virologic and morphologic findings observed in this model of experimental vaccinia virus meningo-encephalitis are discussed with regard to data previously published by other authors. The propensity of strain Ma1 of vaccinia virus (and most probably of other so-called neurovaccinia strains) for replication in mesenchymal cells in particularly emphasized.     

Reduced platelet MAO activity in healthy male students with blood group O

The association between the two genetic markers of affective disorders, ABO blood group system and platelet MAO (monoamine oxidase) activity was studied in 70 healthy young males. The platelet MAO activity of subjects with blood type O was significantly lower than that of subjects with blood type A and with blood types A + B AB + B together. This finding could constitute a "bridge" between the two genetic approaches to affective disorders.     

Peptide formation in the presence of metal ion protecting groups

A quantitative study of the degree of racemization induced by the [(NH₃)₅Co-(III)-] protecting group when bound to the C-terminal of the amino acids Leu, Phe, and His, as has been carried out. Racemization was determined by forming the diastereomeric cobalt dipeptides [(Leu)(AA)Co(III)(NH3)₅] where AA = L-Leu, L-Phe, and L-His; after cobalt removal (using NaBH₄), the peptide diastereomers were analyzed quantitatively using an amino acid analyzer. No racemization was observed within experimental error (0.3%) as a result of the substitution of the [(NH3)₅Co(III)-] group on the amino acids and peptides studied.     

Mathematical aspects of the paternity index I=X/Y,especially in relation to the chance of non-exclusion of non-fathers

Summary In a previous paper the author mentioned some aspects of the paternity index I (=X/Y): Among false triplets the frequency of those with I equal to or higher than an (observed) I value of I ^x is considerably lower than 1/I ^x; among false triplets the mean value of I is equal to 1, and among non-excluded non-fathers it is equal to the inverse of the chance of non-exclusion; among true triplets the mean value of 1/I (=i) is equal to the chance of non-exclusion of non-fathers. In a statistical material rather strong deviations from some of these expectations were observed.In the present paper further characteristics of the distribution of I values were taken into consideration, and especially those that should hold if lnI would fit in with a normal distribution. It was supposed that with the aid of such a distribution the deviations mentioned above could be recognized as chance variability. It appears, however, that neither the logarithms of the paternity index, nor those of the zygosity index of twins (chosen as an analogous model that is more easily analysable than the paternity index) are really normally distributed. This, in turn, makes that estimates of probability of paternity, based on such a supposition, are of doubtful reliability. Besides it is concluded that also for other reasons other estimates than Essen-Möller's W (or I or i), as probability of first type errors, lead in practice to conclusions that are equally subdue to a priori suppositions as are W values and may be, in fact, much more erroneous than those.Special attention is paid to the statistical analysis of paternity studies with more than one alleged father, and it is concluded that in such cases the general formula that may be considered to be equivalent with Essen-Möller's formula for one-man paternity cases, i.e., W=X/(X+Y) or I/(I+1), must be W ₁=I ₁/(I+n); W ₂=I ₂/(I+n) etc. and certainly not W ₁=I ₁/(I+1); W ₂=I ₂/(I+1) etc.Dedicated to Prof. Dr. Erik Essen-Möller on the occasion of his 80th birthday