Integration of geriatrics into a spiral undergraduate medical curriculum in Pakistan: evaluation and feedback of third-year medical students.

BACKGROUND: In the last decades there has been a sharp rise in the elderly population throughout the world. The unique needs of the elderly require a multidisciplinary and comprehensive medical approach. None of the 50 medical schools in Pakistan teach geriatrics in their undergraduate or postgraduate training. This paper discusses the development and implementation of the first geriatric curriculum in a medical school of Pakistan and its effect on knowledge and attitudes of third-year medical students. METHODS: The curriculum was designed through collaboration and approval of various academic departments at the Aga Khan University in Karachi Pakistan. After a review of existing geriatric curricula at other institutions, a problem-based, inter-disciplinary spiral curriculum was designed. Strategy of student and course evaluation was planned and incorporated in the curricular program. No extra resources or funds were used. A component of the new curriculum was assessed by evaluating pre- and post- course knowledge, and seeking feedback from participating third-year students. RESULTS: A significant improvement in mean scores for summed overall knowledge in geriatrics (pre-test mean 4.7 vs. post-test mean 6.4, p value of <0.001; out of a maximum possible of 9 was noted. Breakdown of knowledge mean scores into component areas of knowledge showed a significant increase in understanding in aging demographics (pretest 0.7 vs. post-test 1.7, p value of <0.001), geriatric history taking (pretest 0.64 vs. post-test 0.88, p 0.001) and geriatric assessments (pre- test 1.4 vs. post- test 1.7, p value 0.01). A strong majority (87%) of the students felt that the overall course objectives were achieved. All students were satisfied with the quality of teaching, 90% rating it good or higher. CONCLUSION: An important advance in medical education was achieved via integration of a low cost, spiral geriatrics curriculum in a medical university of Pakistan. We found that introduction of the geriatric curriculum improved the knowledge of third-year medical students. This was our school's initial step towards building professional capacity in response to a rising elderly population.

Late weaning: the most significant risk factor in the development of iron deficiency anaemia at 1-2 years of age.

BACKGROUND: The global prevalence of iron deficiency anaemia in young children is quite high and children between the ages of 1-2 years are at maximum risk. The complications of anaemia are well known, and side effects may go unnoticed and may have an adverse effect on child's life. Therefore, prevention of anaemia becomes enormously important, and the need to look for parameters and predisposing factors that may lead to iron deficiency anaemia in small children is imperative. This study was designed to determine the association of iron deficiency anaemia with late weaning in 1-2 years of children. METHOD: A case control study was conducted from July 1993-July 1995, at the Community Health Centre (CHC), of the Aga Khan University Hospital, at Karachi, Pakistan. The study included 50 cases and 100 controls. A questionnaire was filled by mothers after taking consent. Data was analyzed by chi-square; t-tests, bivariate analysis and multiple logistic regression. RESULTS: Through bivariate analyses, late weaning, family income, mother's education, the numbers of pregnancies, live births and living children, were found to be statistically significant. These variables were run through a multiple logistic regression model and late weaning was found to be the most significant. 60% of cases and 9% of controls were weaned late (p < 0.001). The mean age of weaning was 7.04 months among cases and 4.46 months among controls (p < 0.001). CONCLUSION: Among all the variables studied, late weaning was the most important predictor of iron deficiency anaemia in 1-2 years of age.

Role of immunoglobulin E and mast cells in murine models of asthma.

Immunoglobulin E (IgE) and mast cells are believed to play important roles in allergic inflammation. However, their contributions to the pathogenesis of human asthma have not been clearly established. Significant progress has been made recently in our understanding of airway inflammation and airway hyperresponsiveness through studies of murine models of asthma and genetically engineered mice. Some of the studies have provided significant insights into the role of IgE and mast cells in the allergic airway response. In these models mice are immunized systemically with soluble protein antigens and then receive an antigen challenge through the airways. Bronchoalveolar lavage fluid from mice with allergic airway inflammation contains significant amounts of IgE. The IgE can capture the antigen presented to the airways and the immune complexes so formed can augment allergic airway response in a high-affinity IgE receptor (FcepsilonRI)-dependent manner. Previously, there were conflicting reports regarding the role of mast cells in murine models of asthma, based on studies of mast cell-deficient mice. More recent studies have suggested that the extent to which mast cells contribute to murine models of asthma depends on the experimental conditions employed to generate the airway response. This conclusion was further supported by studies using FcepsilonRI-deficient mice. Therefore, IgE-dependent activation of mast cells plays an important role in the development of allergic airway inflammation and airway hyperresponsiveness in mice under specific conditions. The murine models used should be of value for testing inhibitors of IgE or mast cells for the development of therapeutic agents for human asthma.

Role of immunoglobulin E and mast cells in murine models of asthma

Immunoglobulin E (IgE) and mast cells are believed to play important roles in allergic inflammation. However, their contributions to the pathogenesis of human asthma have not been clearly established. Significant progress has been made recently in our understanding of airway inflammation and airway hyperresponsiveness through studies of murine models of asthma and genetically engineered mice. Some of the studies have provided significant insights into the role of IgE and mast cells in the allergic airway response. In these models mice are immunized systemically with soluble protein antigens and then receive an antigen challenge through the airways. Bronchoalveolar lavage fluid from mice with allergic airway inflammation contains significant amounts of IgE. The IgE can capture the antigen presented to the airways and the immune complexes so formed can augment allergic airway response in a high-affinity IgE receptor (FcepsilonRI)-dependent manner. Previously, there were conflicting reports regarding the role of mast cells in murine models of asthma, based on studies of mast cell-deficient mice. More recent studies have suggested that the extent to which mast cells contribute to murine models of asthma depends on the experimental conditions employed to generate the airway response. This conclusion was further supported by studies using FcepsilonRI-deficient mice. Therefore, IgE-dependent activation of mast cells plays an important role in the development of allergic airway inflammation and airway hyperresponsiveness in mice under specific conditions. The murine models used should be of value for testing inhibitors of IgE or mast cells for the development of therapeutic agents for human asthma

Association of iron deficiency anaemia in children of 1-2 years of age with low birth weight, recurrent diarrhoea or recurrent respiratory tract infection--a myth or fact?

AIMS AND OBJECTIVE: To investigate for the presence or absence of any association between low birth weight, recurrent diarrhoea or recurrent acute respiratory infections with iron deficiency anaemia in Pakistani children aged 1-2 years. METHODOLOGY: From July 1993 to July 1995 a case control study was conducted at the Community Health Centre (CHC). Fifty cases and 100 controls were included. Informed consent was taken from mothers for the blood tests of their children and a questionnaire was administered to them. Data obtained from the completed questionnaires was analyzed by chi-square and t-tests. RESULTS: There was no statistically significant difference in low birth weight (p = 0.712), recurrent diarrhoea or respiratory infections between anaemic and non-anaemic children at 1-2 years age (OR of 1.71 and 1.48 respectively). CONCLUSION: This study does not uphold the belief that low birth weight, recurrent diarrhoea or respiratory infections have a causal association with iron deficiency anaemia in 1-2 years children.

Anti-Galectin-3 IgG autoantibodies in patients with Crohn's disease characterized by means of phage display peptide libraries.

Galectin-3, a member of beta-galactoside-binding lectins, is expressed and secreted by a variety of cell types including human intestinal epithelial cells. The presence of anti-galectin-3 antibody in the sera of patients was analyzed by immunoblotting using recombinant human galectin-3. A substantially higher percentage of sera from Crohn's disease patients contained anti-galectin-3 IgG autoantibodies than from patients with ulcerative colitis, primary biliary cirrhosis, or autoimmune hepatitis and of apparently healthy control volunteers. In Crohn's disease patients the titer of autoantibodies was high and interestingly correlated negatively with disease activity. To characterize and generate artificial epitopes (mimotopes), the anti-galectin-3 monoclonal antibodies A3A12 and B2C10 were used for biopannings of phage display nonapeptide libraries. These mimotopes interfered with the binding of autoantibodies to recombinant and native intestinal epithelial galectin-3. Our data may suggest that galectin-3 mimotopes could be used for the induction of IgG with desired specificity to regulate immune responses in Crohn's disease patients.

Production of dextran from sucrose by a newly isolated strain of Leuconostoc mesenteroides (PCSIR-3) with reference to L. mesenteroides NRRL B-512F.

A newly isolated strain of Leuconostoc mesenteroides (PCSIR-3) produced a different dextran compared with that of L. mesenteroides NRRL B-512F. Different media compositions used for dextran production showed that media containing CaCl(2) produced dextran in higher quantities compared with other media. The viscosity of the dextran produced in different media varied in nature. Dextran from media 1 and 2 was of higher molecular mass compared with that from media 3, 4 and 5. Dextran production is also effected by the sucrose concentration in the media. The higher the initial concentration of sucrose, the higher is the yield of dextran produced per unit volume; however, the percentage conversion of sucrose into dextran decreases. A continuous drop in pH was associated with growth and dextran production. The yield of dextran increases during the growth phase and maximum yield was obtained at the end of the exponential phase. Dextran produced by L. mesenteroides PCSIR-3 is quite different from the dextran produced by NRRL B-512F. Maximum dextran production from L. mesenteroides PCSIR-3 occurs in 18 h compared with 12 h for NRRL B-512F.

The relationship of socio-demographic factors with iron deficiency anaemia in children of 1-2 years of age.

OBJECTIVE: To investigate associations between different socio-demographic factors with iron deficiency anaemia in Pakistani children of 1-2 years of age. METHODOLOGY: A case control study, with 50 cases and 100 controls, was conducted at the Community Health Centre, an outpatient clinic of the Aga Khan University, Karachi, Pakistan, between July 1993-July 1995. Informed consent was taken from mothers for their children's blood tests and a questionnaire was administered to them. The data was analyzed using chi-square, t-tests and logistic regression. RESULTS: The numbers of pregnancies, live births and living children were more among cases than controls but the differences were not statistically significant. Although father's education did not show a significant association (OR 1.35, 95% CI 0.22-8.33), maternal education was significantly associated with the children's anaemic status (OR 3.55, 95% CI 1.40-9.02). The difference in monthly incomes between families of cases and controls was the most significant variable among all those studied (p-value 0.006). CONCLUSION: This study showed that while lack of maternal education and low monthly family incomes are both significantly associated with the development of childhood anaemia, low monthly income is most significant.

Development of allergic inflammation in a murine model of asthma is dependent on the costimulatory receptor OX40.

Asthma is thought to result from an abnormal expansion of CD4 T cells reactive with airborne allergens, and pathology is controlled by several cytokines of the T helper type 2 (Th2) family. The exact molecules which are involved in generating allergen-reactive T cells are not clear. Studies with blocking reagents or knockout animals have shown that the CD28/B7 interaction partially controls development of allergic asthma in mouse models, but may not be the sole molecule involved. In this report, we have investigated the role of the tumor necrosis factor receptor family member OX40 in allergic inflammation using OX40-deficient mice. OX40 has been shown to participate in regulating clonal expansion and memory development of CD4 T cells and may synergize with CD28. Our studies demonstrate that OX40(-/)- mice, primed with the model allergen ovalbumin and challenged through the airways with aerosolized antigen, are severely impaired in their ability to generate a Th2 response characterized by high levels of interleukin (IL)-5, IL-4, and immunoglobulin E. Moreover, OX40(-/)- mice exhibit diminished lung inflammation, including an 80-90% reduction in eosinophilia and mucus production, less goblet cell hyperplasia, and significantly attenuated airway hyperreactivity. These studies highlight the potential importance of OX40 in development of allergic asthma and suggest that targeting OX40 may prove useful therapeutically.

Role for IgE in airway secretions: IgE immune complexes are more potent inducers than antigen alone of airway inflammation in a murine model.

IgE is present in airway secretions from human patients with allergic rhinitis and bronchial asthma. However, the contribution of IgE present locally to the overall airway inflammation is not well understood. We hypothesize that Ag-specific IgE can capture airborne Ags and form immune complexes. These immune complexes may function as potent inducers of immune responses in the lung, contributing to the perpetuation of airway inflammation. BALB/c mice were first sensitized with OVA in alum systemically and then challenged with nebulized OVA. Bronchoalveolar lavage (BAL) fluid from these mice contained significant amounts of IgE, of which >50% was Ag specific. The IgE levels in airway secretions remained elevated for more than 15 days after the termination of Ag exposure. Significant amounts of IgE-OVA immune complexes were detected in BAL fluid from the OVA-challenged mice. For comparison of IgE immune complexes vs Ag alone, we treated OVA-immunized mice with intranasal administration of trinitrophenyl-OVA or trinitrophenyl-OVA-anti-DNP IgE. Those treated with the immune complexes showed significantly higher levels of IL-4 and more pronounced eosinophilia in BAL fluid than did those receiving the Ag alone. The IgE immune complexes did not augment the inflammatory response in high affinity IgE receptor (FcepsilonRI)-deficient mice. We conclude that IgE present in the airways can capture the Ag and that the immune complexes thus formed may augment allergic airway response in an FcepsilonRI-dependent manner. Thus, IgE present in airway secretions may facilitate Ag-mediated allergic airway inflammation.

Center-based prevalence of anxiety and depression in women of the northern areas of Pakistan.

OBJECTIVE: To estimate the prevalence of anxiety and depression in women of the Northern areas. METHODS: A cross-sectional center-based study was conducted at Singal Medical Center (SMC), Gilgit, in the Northern Areas of Pakistan, using the Hospital Anxiety and Depression Scale (HADS). RESULTS: One hundred and twenty women, between the ages of 16 and 60, attended the SMC over a two month period and were included in the study. Using HADS, it was found that 50% of the women had anxiety and/or depression; 25% suffered only from anxiety, 8% from depression and 17% had features of both. CONCLUSION: This study supports the previous studies of stress in remote areas and also contradicts the belief that people who live in the remote rural areas lead stress-free lives or have low rates of psychiatric morbidity (JPMA 50:138, 2000).

Efficient epitope mapping by bacteriophage lambda surface display.

A bacteriophage lambda surface expression system, lambda foo, was used for epitope mapping of human galectin-3. We constructed random epitope and peptide libraries and compared their efficiencies in the mapping. The galectin-3 cDNA was randomly digested by DNase 1 to make random epitope libraries. The libraries were screened by affinity selection using a microtiter plate coated with monoclonal antibodies. Direct DNA sequencing of the selected clones defined two distinct epitope sites consisting of nine and 11 amino-acid residues. Affinity selection of random peptide libraries recovered a number of sequences that were similar to each other but distinct from the galectin-3 sequence. These results demonstrate that a single affinity selection of epitope libraries with antibodies is able to define an epitope determinant as small as nine residues long and is more efficient in epitope mapping than random peptide libraries.

Modulation of functional properties of galectin-3 by monoclonal antibodies binding to the non-lectin domains.

Galectin-3 is a member of a newly defined family of animal lectins, which is composed of three domains: a small amino-terminal domain, a domain containing repeating elements, and a carboxyl-terminal domain containing the carbohydrate-recognition site. Various functions have been described or proposed for this lectin, and it appears that galectin-3 has diverse roles. Murine monoclonal antibodies (MAbs) have been generated from mice hyperimmunized with recombinant human galectin-3 or galectin-3C (the carboxyl-terminal domain), and seven MAbs have been characterized in detail. All MAbs generated against the intact galectin-3 recognize the amino-terminal region of the molecule, as demonstrated by ELISA and immunoblotting using recombinant galectin-3C and galectin-3NR, which contains the amino-terminal domain and all the repeating elements. Their epitopes were all found to be within the first 45 amino acids of galectin-3, as determined by using galectin-3 mutants with a truncated amino-terminal region. However, these MAbs were found to profoundly modulate the lectin activities of galectin-3. The MAb B2C10 inhibited (i) the binding of 125I-labeled galectin-3 to IgE coated on microtiter plates; (ii) the galectin-3's hemagglutination activity; and (iii) galectin-3-induced superoxide production by human neutrophils. Other MAbs, especially A3A12, caused marked potentiation of these activities. The results support our model that the lectin function of galectin-3 is influenced by protein homodimerization resulting from self-association of the amino-terminal region of the molecule. The potentiating activities of some MAbs are probably due to facilitation of dimerization galectin-3, and the inhibitory activity of MAb B2C10 is probably the result of its disruption of the self-association process.

Expression and function of galectin-3, a beta-galactoside-binding lectin, in human monocytes and macrophages.

A family of beta-galactoside-binding animal lectins has recently been designated as galectins. One member of this family, galectin-3, has been known as epsilon BP for its IgE-binding activity and as Mac-2, a macrophage surface antigen, CBP35, CBP30, L-29, and L-34. Although much information has accumulated on the expression of this lectin in murine macrophages and human monocytic cell lines, little is known about the expression and function of this protein in normal human monocytes/macrophages. We now report that galectin-3 is expressed in normal human peripheral blood monocytes and its level increases dramatically as human monocytes differentiate into macrophages upon culturing in vitro. Immunoblot analysis showed that there was a 5-fold increase in the level of galectin-3 after 1 day of culture and greater than a 12-fold increase after 5 days. Immunocytochemical analysis confirmed this progressive increase of galectin-3 expression in cultured monocytes. Immunogold cytochemistry/electron microscopy analysis revealed that galectin-3 was expressed on the surface of human monocytes and that the level of cell surface galectin-3 increased progressively as these cells differentiated into macrophages. The level of galectin-3 in human monocytes/macrophages was modulated by stimuli such as lipopolysaccharide and interferon-gamma, and galectin-3 was secreted when monocytes were stimulated by calcium ionophore A23187 Soluble galectin-3 caused superoxide release from human monocytes; this activity was dependent on the lectin property of galectin-3, as it was inhibitable by lactose. Thus, galectin-3 may modulate the function of this cell type in an autocrine or paracrine fashion through binding to cell surface glycoconjugates.

Activation of rat basophilic leukemia cells by epsilon BP, an IgE-binding endogenous lectin.

IgE-binding protein (epsilon BP) is a beta-galactoside-binding animal lectin identified by its affinity for IgE. We have reported that epsilon BP also binds the mast cell high-affinity IgE receptor (Fc epsilon RI), via lectin-carbohydrate interaction. We have now studied the physiological significance of epsilon BP-IgE-Fc epsilon RI interactions in mast cell activation using rat basophilic leukemia (RBL) cells as the model system. We report here that both unsensitized and IgE-sensitized RBL cells are activated upon exposure to epsilon BP-coated surfaces. Activation of RBL cells by the lectin epsilon BP can be significantly inhibited by appropriate saccharides. Exposure of RBL cells to epsilon BP-coated surfaces caused cell spreading similar to that caused from adherence to fibronectin-coated surfaces. However, epsilon BP by itself caused mediator release whereas fibronectin only potentiated antigen-mediated activation of RBL cells. Under appropriate conditions, epsilon BP, therefore, has the potential to activate mast cells culminating in augmentation of an inflammatory response.

Expression and function of an IgE-binding animal lectin (epsilon BP) in mast cells.

epsilon BP (IgE-binding protein) is a 31,000 M(r) protein originally identified in rat basophilic leukemia (RBL) cells. The protein is composed of two domains with the amino-terminal domain containing a highly conserved repetitive sequence and the carboxyl-terminal domain containing consensus sequences shared by other beta-galactoside-binding soluble lectins. The protein has wide tissue distribution, is found on cell surfaces and in extracellular milieu. By combined efforts from several research groups including ours a multifunctional nature of this lectin began to emerge. This review emphasizes the following characteristics of epsilon BP: (i) epsilon BP is secreted by cells such as macrophages; (ii) like many other lectins, epsilon BP functions at least bivalently; (iii) epsilon BP has specificity for distinct oligosaccharide structures that have a terminal galactose not masked by sialic acids; and (iv) in addition to binding IgE, epsilon BP binds to surfaces of various cell types via lectin-carbohydrate interaction. Importantly, epsilon BP binds to the IgE receptor on mast cells. We propose that epsilon BP can function as a modulatory protein on various cells by cross-linking critical cell surface glycoproteins. The proposed action of epsilon BP on mast cells is presented as a model.

The diploma in family medicine examination; a scientific exercise.

The Diploma in Family Medicine (DFM) Examination is a new certification offered by the College of Physicians and Surgeons of Pakistan, and its Department of Medical Education designed a scientific examination. First, the Expert Advisory Committee for Family Medicine was formed, relevant training objectives were determined, a training programme to achieve the objectives was designed and a valid syllabus was chosen. Then the examination was designed, where the candidates must pass the objective theory papers before taking the clinical examination. The clinical examination consisted of an Objective Structured Clinical Examination (OSCE) and traditional case presentations. The candidates had to pass each of the components, and attain an overall aggregate of 60%. In the first six examinations, 752 candidates sat for the theory examinations, 332 (44.14%) were eligible for the clinical examination, and 170 (23%) passed. If 60% marks obtained in case presentations is taken as the gold standard which is the current CPSP policy and compared to OSCE marks, then 75% marks in OSCE had a sensitivity of 67% and a specificity of 79%.

Epsilon BP, a beta-galactoside-binding animal lectin, recognizes IgE receptor (Fc epsilon RI) and activates mast cells.

IgE-binding protein (epsilon BP) was originally identified in rat basophilic leukemia (RBL) cells by virtue of its affinity for IgE. epsilon BP is now known to be a beta-galactoside-binding lectin containing an S-type carbohydrate recognition domain. It is identical to a macrophage surface antigen, Mac-2, and lectins designated as CBP35, L-34, and RL-29, for which various functions have been suggested. Studies from other groups as well as ours have indicated that epsilon BP is secreted by cells such as macrophages and is present in extracellular fluids. We demonstrated previously that binding sites for epsilon BP are present on the surface of RBL cells. In this report, we show that epsilon BP binds to a small number of glycoprotein species on the surface of RBL cells. Significantly, one of these glycoproteins is the high-affinity IgE receptor (Fc epsilon RI). Preliminary studies showed that epsilon BP causes mediator release from RBL cells, possibly through cross-linking of Fc epsilon RI. The results suggest a function of epsilon BP as an activator of mast cells.