Mitochondrial C5aR1 activity in macrophages controls IL-1β production underlying sterile inflammation

While serum-circulating complement destroys invading pathogens, intracellularly active complement, termed the “complosome,” functions as a vital orchestrator of cell-metabolic events underlying T cell effector responses. Whether intracellular complement is also nonredundant for the activity of myeloid immune cells is currently unknown. Here, we show that monocytes and macrophages constitutively express complement component (C) 5 and generate autocrine C5a via formation of an intracellular C5 convertase. Cholesterol crystal sensing by macrophages induced C5aR1 signaling on mitochondrial membranes, which shifted ATP production via reverse electron chain flux toward reactive oxygen species generation and anaerobic glycolysis to favor IL-1β production, both at the transcriptional level and processing of pro–IL-1β. Consequently, atherosclerosis-prone mice lacking macrophage-specific C5ar1 had ameliorated cardiovascular disease on a high-cholesterol diet. Conversely, inflammatory gene signatures and IL-1β produced by cells in unstable atherosclerotic plaques of patients were normalized by a specific cell-permeable C5aR1 antagonist. Deficiency of the macrophage cell-autonomous C5 system also protected mice from crystal nephropathy mediated by folic acid. These data demonstrate the unexpected intracellular formation of a C5 convertase and identify C5aR1 as a direct modulator of mitochondrial function and inflammatory output from myeloid cells. Together, these findings suggest that the complosome is a contributor to the biologic processes underlying sterile inflammation and indicate that targeting this system could be beneficial in macrophage-dependent diseases, such as atherosclerosis.

Identifying individuals with multiple non-communicable disease risk factors in Kenya: a latent class analysis

OBJECTIVES

Non-communicable diseases (NCDs) are the leading causes of death globally. In Kenya, the number of deaths resulting from NCDs is projected to surpass malaria and tuberculosis by 2030. Studies in Kenya show increasing NCDs; the aim of the present study is to examine the clustering of NCDs and risk factors in Kenya.

STUDY DESIGN

This is a cross-sectional study using data from the 2015 Kenya STEPwise Survey.

METHODS

This study examined relationships between NCDs (e.g. obesity, hypertension and diabetes) and health behaviours (e.g. sedentary activity, and fruit and vegetable consumption). Survey probability weights, which estimated the sampling design effect, were applied to consider the sampling units, and stratifications were used during sampling so that the results could be generalisable to the national adult Kenyan population. In total, 4350 adults were included in the study sample.

RESULTS

Overall, 24.43% of participants were classified as having hypertension, 1.88% as having type 2 diabetes, and 27.94% were classified as being overweight or obese. The best-fit model was a four-class solution. Class 1 is best described as 'young with high NCD risk' and had the highest sedentary activity. Class 2 is best described as 'poor rural with lower NCD risk' with a high chance of smoking and alcohol consumption. Class 3 is best described as 'rural with high NCD risk' and had the highest fruit and vegetable consumption. Class 4 is best described as 'wealthy young urban dwellers with high NCD risk' with a high chance of alcohol consumption and smoking. Individuals in Class 4 had the highest chance (40%) of being overweight/obese, a 2% chance of type 2 diabetes and a 23% chance of having hypertension.

CONCLUSIONS

NCDs are clustered in groups with high-risk behaviours. The group with the highest chance of having NCDs also had the highest chance of engaging in high-risk behaviours. The findings of this study suggest that smoking and alcohol consumption increase NCD risk in rural areas. Tailored and targeted interventions are needed to curb the increasing NCD prevalence in Kenya.

The C3-like molecule CD109 controls Th1 versus Th17 induction in CD4+ T cells

Recent workdefined an unexpected and critical role for intracellular/autocrine active complement in human Th1 biology. Specifically, autocrine stimulation of CD46via TCR-induced C3b generation is needed for IFN-γ production by human CD4+ T cells. Thus, CD46-deficient patients are unable to generate normal Th1 responses. Analysis of the CD46-driven gene signature in Th1 cells revealed CD109 as a direct target of CD46. Indeed, T cells from CD46 deficient patients and from healthy donors in which CD46 expression was ablated via CRISPR-Cas9 technology failed to upregulate CD109. CD109 is aGPI-linked surface protein, mostly expressed on non-immune cells, and belongs to the complement C3 protein family. Though CD109 has been reported as a major negative regulator of TGF-β receptor signaling, direct functional activity for of CD109 on T cells remains unexplored.

Knock-out of CD109 in human CD4+ T cells with CRISPR-Cas9 technology induced uncontrolled Th1 and Th17 activation upon in vitro stimulation under non-skewing conditions. Similarly, CD4+T cells from Cd109−/− mice displayed augmented Th1 and Th17 in vitro responses and caused significantly more tissue pathology and weight loss in a T cell-transfer colitis model. Surprisingly, on T cells, CD109 does not restrain IFN-γ and/or IL-17 induction via modulation of TGF-β receptor activity. Instead, CD109 engages with a non-canonical costimulatory molecule and controls stemness- and metabolism-related signaling pathways.

Together, these data suggest that the complement-related protein CD109 serves as an important and novel molecular switch on CD4+ T-cells, where it regulates the balance between Th1 and Th17-induction pathways.

From the lecture theatre to your digital device: Reflections on the production of educational podcasts within undergraduate psychiatry training

Introduction

The COVID-19 pandemic has highlighted a need for engaging online resources to enrich psychiatry training for undergraduate medical students. Podcasting is a well-established digital communication platform utilised daily in a myriad of capacities, including education. A group of medical students were tasked with creating their own educational podcasts covering specific aspects of psychiatry.

Objectives

Each pair was set a sub-topic of psychiatry and utilised software to produce educational resources. The objective of this project was to reflect upon production as well as explore the efficacy of podcasting as a tool within undergraduate training.

Methods

The medical students conducted research and contacted experts within the field to contribute to their podcasts. The majority of the students then conducted reviews of the literature surrounding podcasting within medical education, which informed the production of their own podcasts. From this, it was discussed how this project could impact future practice, and indicated that podcasts may become crucial asynchronous learning tools in medical education.

Results

Literature review and first-hand experience of podcast production enabled the students to appreciate the advantages of podcasting and the potential for its widespread future applications. Their wider reading revealed that podcast-using study participants outperformed or matched their peers in assessments, and overwhelmingly enjoyed using podcasts over traditional teaching methods.

Conclusions

The use of podcasting can complement traditional psychiatry training and appeal to a generation of digital natives that prefer this learning style. Podcast production is also an excellent revision method, highlighting the advantages of peer-to-peer education in both learning and increasing engagement with psychiatry.

Disclosure

No significant relationships.

Complement's favourite organelle-Mitochondria?

The complement system, well known for its central role in innate immunity, is currently emerging as an unexpected, cell‐autonomous, orchestrator of normal cell physiology. Specifically, an intracellularly active complement system—the complosome—controls key pathways of normal cell metabolism during immune cell homeostasis and effector function. So far, we know little about the exact structure and localization of intracellular complement components within and among cells. A common scheme, however, is that they operate in crosstalk with other intracellular immune sensors, such as inflammasomes, and that they impact on the activity of key subcellular compartments. Among cell compartments, mitochondria appear to have built a particularly early and strong relationship with the complosome and extracellularly active complement—not surprising in view of the strong impact of the complosome on metabolism. In this review, we will hence summarize the current knowledge about the close complosome–mitochondria relationship and also discuss key questions surrounding this novel research area.

Diapedesis-Induced Integrin Signaling via LFA-1 Facilitates Tissue Immunity by Inducing Intrinsic Complement C3 Expression in Immune Cells

Intrinsic complement C3 activity is integral to human T helper type 1 (Th1) and cytotoxic T cell responses. Increased or decreased intracellular C3 results in autoimmunity and infections, respectively. The mechanisms regulating intracellular C3 expression remain undefined. We identified complement, including C3, as among the most significantly enriched biological pathway in tissue-occupying cells. We generated C3-reporter mice and confirmed that C3 expression was a defining feature of tissue-immune cells, including T cells and monocytes, occurred during transendothelial diapedesis, and depended on integrin lymphocyte-function-associated antigen 1 (LFA-1) signals. Immune cells from patients with leukocyte adhesion deficiency type 1 (LAD-1) had reduced C3 transcripts and diminished effector activities, which could be rescued proportionally by intracellular C3 provision. Conversely, increased C3 expression by T cells from arthritis patients correlated with disease severity. Our study defines integrins as key controllers of intracellular complement, demonstrates that perturbations in the LFA-1-C3-axis contribute to primary immunodeficiency, and identifies intracellular C3 as biomarker of severity in autoimmunity.

Integrins meet complement: The evolutionary tip of an iceberg orchestrating metabolism and immunity

Immunologists have recently realized that there is more to the classic innate immune sensor systems than just mere protection against invading pathogens. It is becoming increasingly clear that such sensors, including the inflammasomes, toll-like receptors, and the complement system, are heavily involved in the regulation of basic cell physiological processes and particularly those of metabolic nature. In fact, their "non-canonical" activities make sense as no system directing immune cell activity can perform such task without the need for energy. Further, many of these ancient immune sensors appeared early and concurrently during evolution, particularly during the developmental leap from the single-cell organisms to multicellularity, and therefore crosstalk heavily with each other. Here, we will review the current knowledge about the emerging cooperation between the major inter-cell communicators, integrins, and the cell-autonomous intracellularly and autocrine-active complement, the complosome, during the regulation of single-cell metabolism. LINKED ARTICLES: This article is part of a themed issue on Canonical and non-canonical functions of the complement system in health and disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.14/issuetoc.

Diapedesis and LFA-1 mediate tissue immune cell effector activity via intrinsic complement C3 licensing

Intracellularly generated and autocrine-functioning complement component C3 is a critical integral part of normal human CD4+ Th1 and cytotoxic CD8+ T cells responses. Increased or decreased intracellular C3 result in autoimmunity and infections, respectively. The mechanisms regulating intracellular C3 expression are, however, undefined. By comparing transcriptomes from blood and tissue, we identified the complement system, including C3, as one of the most significantly enriched biological pathways in tissue-occupying cells of human macrophages, CD4+ and CD8+ T cells. By leveraging a novel C3 reporter mouse, we confirmed that C3 gene transcription is a feature of immune cells in tissues, is induced during trans-endothelial diapedesis, and is dependent on the integrin intercellular adhesion molecule (ICAM)-1 liganding lymphocyte function-associated antigen (LFA)-1. Consequently, monocytes and T cells from patients with leukocyte adhesion deficiency (LAD)-1 had reduced C3 and diminished effector activities, which could be rescued proportionally by normalization of intracellular C3. In synovia of patients with rheumatoid arthritis (RA), C3 transcript expression by CD4+ T cells was linearly associated with disease severity and acted as a biomarker distinguishing inflamed versus uninflamed RA. Our study defines the integrin network as a novel and key controller of intracellular complement, demonstrates that perturbations in the LFA-1–C3 axis contribute to primary human immunodeficiency and identifies T cell C3 production as a biomarker of the severity of autoimmunity.

Cholesterol crystals use both extracellular and intracellular complement to increase NLRP3 signalling pathways in atherosclerosis

During atherosclerosis, cholesterol precipitates into cholesterol crystals (CC) in the vessel wall which trigger plaque inflammation. In the present, study we examined the relation between complement, NLRP3 signalling pathways and CC in patients with coronary artery disease and carotid atherosclerosis. We analysed plasma, peripheral blood mononuclear cells (PBMC) and carotid plaques from patients with different degrees of atherosclerosis applying ELISAs, multiplex, qPCR, immunohistochemistry, gene profiling and bioinformatics. Transcripts of IL-1β and NLRP3 were increased and correlated in PBMC from patients with acute coronary syndrome. Immunohistochemistry of carotid plaques showed pronounced accumulation of C1q and terminal C5b-9 complement complex (TCC) around CC-clefts. Transcripts of C5aR1, C5aR2 and C3aR1 were increased in carotid plaques compared to control arteries. Priming of carotid plaques ex vivo with C5a and TNF followed by CC incubation resulted in pronounced upregulation of NLRP3 inflammasome components. Importantly, we found that intracellular “C5 system” is a major contributor of CC induced IL-1β in human macrophages through the action of C5aR1 present on mitochondria. Mechanisms underlaying the role of intracellular C5 in this process will be described. The data suggest that CC formation is an important extracellular and intracellular complement activator which in turn results in IL-1β expression and activation of NLRP3 in atherosclerotic plaques.

The C3-like molecule CD109 controls Th1 versus Th17 induction in CD4+ T cells

Recent work defined an unexpected and critical role for intracellular/autocrine active complement in human Th1 biology. Specifically, autocrine stimulation of CD46 via TCR-induced C3b generation is needed for IFN-γ production by human CD4+T cells. Analysis of the CD46-driven gene signature in Th1 cells revealed CD109, a C3-like surface protein known to regulate TGF-β signaling, as a direct target of CD46. We confirmed that T cells from patients with CD46 deficiency, which suffer from recurrent infection due to reduced Th1 responses, and from healthy donors knocked-out for CD46 via CRISPR-Cas9 technology failed to upregulate CD109. CD109 is expressed on keratinocytes, endothelial and stem cells and overexpression is connected with cancer but its function on T cells remains unexplored.

In vitro activation of mouse Cd109−/− CD4+ T-cells showed a strong increase of Th1- and Th17-related cytokines compare to their WT counterpart. In line with this observation, Cd109−/− mouse CD4+ T cells showed an increase in IL-17A+ and IFN-γ+/IL-17A+ T cell numbers in vivo and caused significantly more weight loss and disease pathology in a T cell-transfer colitis model. Although CD109 is known to regulate TGF-β signaling, our RNA-sequencing analysis of activated Cd109−/− mouse T cells revealed that this molecule is restraining Th17 induction rather via impact on cell cycle and apoptosis related pathways, which we are investigating now.

Together, these data suggest that the complement-related protein CD109 serves as an important and novel molecular switch on CD4+ T-cells, where it regulates the balance between Th1 and Th17-induction pathways.

Complement receptor CD46 co-stimulates optimal human CD8+ T cell effector function via fatty acid metabolism

The induction of human CD4+ Th1 cells requires autocrine stimulation of the complement receptor CD46 in direct crosstalk with a CD4+ T cell-intrinsic NLRP3 inflammasome. However, it is unclear whether human cytotoxic CD8+ T cell (CTL) responses also rely on an intrinsic complement-inflammasome axis. Here we show, using CTLs from patients with CD46 deficiency or with constitutively-active NLRP3, that CD46 delivers co-stimulatory signals for optimal CTL activity by augmenting nutrient-influx and fatty acid synthesis. Surprisingly, although CTLs express NLRP3, a canonical NLRP3 inflammasome is not required for normal human CTL activity, as CTLs from patients with hyperactive NLRP3 activity function normally. These findings establish autocrine complement and CD46 activity as integral components of normal human CTL biology, and, since CD46 is only present in humans, emphasize the divergent roles of innate immune sensors between mice and men.

Molecular Analysis of Healing at a Bone-Implant Interface

While bone healing occurs around implants, the extent to which this differs from healing at sites without implants remains unknown. We tested the hypothesis that an implant surface may affect the early stages of healing. In a new mouse model, we made cellular and molecular evaluations of healing at bone-implant interfaces vs. empty cortical defects. We assessed healing around Ti-6Al-4V, poly(L-lactide-co-D,L,-lactide), and 303 stainless steel implants with surface characteristics comparable with those of commercial implants. Our qualitative cellular and molecular evaluations showed that osteoblast differentiation and new bone deposition began sooner around the implants, suggesting that the implant surface and microenvironment around implants favored osteogenesis. The general stages of healing in this mouse model resembled those in larger animal models, and supported the use of this new model as a test bed for studying cellular and molecular responses to biomaterial and biomechanical conditions.

Revision cartilage cell transplantation for failed autologous chondrocyte transplantation in chronic osteochondral defects of the knee

The management of failed autologous chondrocyte implantation (ACI) and matrix-assisted autologous chondrocyte implantation (MACI) for the treatment of symptomatic osteochondral defects in the knee represents a major challenge. Patients are young, active and usually unsuitable for prosthetic replacement. This study reports the results in patients who underwent revision cartilage transplantation of their original ACI/MACI graft for clinical or graft-related failure. We assessed 22 patients (12 men and 10 women) with a mean age of 37.4 years (18 to 48) at a mean of 5.4 years (1.3 to 10.9). The mean period between primary and revision grafting was 46.1 months (7 to 89). The mean defect size was 446.6 mm(2) (150 to 875) and they were located on 11 medial and two lateral femoral condyles, eight patellae and one trochlea. The mean modified Cincinnati knee score improved from 40.5 (16 to 77) pre-operatively to 64.9 (8 to 94) at their most recent review (p < 0.001). The visual analogue pain score improved from 6.1 (3 to 9) to 4.7 (0 to 10) (p = 0.042). A total of 14 patients (63%) reported an 'excellent' (n = 6) or 'good' (n = 8) clinical outcome, 5 'fair' and one 'poor' outcome. Two patients underwent patellofemoral joint replacement. This study demonstrates that revision cartilage transplantation after primary ACI and MACI can yield acceptable functional results and continue to preserve the joint.

Nutritional status and dietary intake of children with acute leukaemia during induction or consolidation chemotherapy

BACKGROUND

The assessment of nutritional status among paediatric patients is important for the planning and execution of nutritional strategies that strive to optimise the quality of life and growth among sick children. The present study aimed to evaluate the nutritional status and dietary intake among children with acute leukaemia.

METHODS

This cross-sectional study included 53 paediatric patients aged 3-12 years old, who were diagnosed with either acute lymphoblastic leukaemia or acute myelogenous leukaemia and were undergoing chemotherapy treatments (induction or consolidation phase). Patients were matched for sex, age (±6 months) and ethnicity with healthy children as controls. Weight, height, body mass index, waist circumference, mid-upper arm circumference, triceps skinfold thickness, mid-upper arm muscle area and fat area were determined. Dietary intake was assessed using 3-day food records.

RESULTS

Anthropometric variables were generally higher among patients compared to controls, although the differences were not statistically significant (P > 0.05). The prevalence of overnutrition among patients according to body mass index-for-age, waist circumference-for-age, mid-upper arm circumference-for-age and triceps skinfold-for-age were 24.5%, 29.1%, 17.0% and 30.2%, respectively. Mean energy [5732 ± 1958 kJ (1370 ± 468 kcal) versus 6945 ± 1970 kJ (1660 ± 471 kcal), P < 0.01], protein (50.0 ± 19.7 g versus 62.3 ± 22.3 g, P < 0.01) and fat (43.6 ± 18.9 g versus 58.3 ± 16.7, P < 0.001) intakes of patients were significantly lower than controls.

CONCLUSIONS

The prevalence of being overweight and obesity in children with acute leukaemia was higher despite lower energy intake compared to controls. Studies assessing physical activity, the complex interaction and the effects of treatment drugs are warranted to better manage malnutrition among paediatric patients.

Higher cytotoxic capacity in peripheral blood of sarcoidosis patients (P3135)

BACKGROUND. Sarcoidosis is a granulomatous disease of unknown etiology, mainly affecting the lungs, where greatly increased numbers of CD4+ T cells typically are seen. However, CD8+ T cells can sometimes make up the majority of cells recovered by bronchoalveolar lavage (BAL). Previous studies have extensively studied Th1 cytokine-producing T cells and established their role in the pathological process. Little is however known about cytotoxic cells in sarcoidosis. METHODS: Peripheral blood (from 17 sarcoidosis patients and 11 healthy controls) and BAL fluid (from 19 patients and 4 controls) was obtained. Flow cytometric analysis of cell subsets was performed after staining with antibodies against the surface molecules CD3, CD4 and CD8 as well as antibodies against the cytotoxic intracellular mediators perforin, granzyme B and granulysine. The PBMC cytotoxic activity was quantified with the 51Cr release assay. RESULTS: Sarcoidosis patients had a significantly higher percentage of both perforin+ (p &lt; 0.001) and granzyme B+ (p &lt; 0.05) CD8+ T cells in blood. In BAL, however, a tendency in the opposite direction was seen. Higher cytotoxic activity was observed in PBMC from patients with sarcoidosis compared to controls. CONCLUSION: Cytotoxic cells, including CD8+ T cells, may be involved in the propagation or regulation of the inflammatory process in sarcoidosis, but further studies are needed to delineate their role in this disease.

Prime-boost vaccination with rBCG/rAd35 enhances CD8⁺ cytolytic T-cell responses in lesions from Mycobacterium tuberculosis-infected primates

To prevent the global spread of tuberculosis (TB) infection, a novel vaccine that triggers potent and long-lived immunity is urgently required. A plasmid-based vaccine has been developed to enhance activation of major histocompatibility complex (MHC) class I-restricted CD8⁺ cytolytic T cells using a recombinant Bacille Calmette-Guérin (rBCG) expressing a pore-forming toxin and the Mycobacterium tuberculosis (Mtb) antigens Ag85A, 85B and TB10.4 followed by a booster with a nonreplicating adenovirus 35 (rAd35) vaccine vector encoding the same Mtb antigens. Here, the capacity of the rBCG/rAd35 vaccine to induce protective and biologically relevant CD8⁺ T-cell responses in a nonhuman primate model of TB was investigated. After prime/boost immunizations and challenge with virulent Mtb in rhesus macaques, quantification of immune responses at the single-cell level in cryopreserved tissue specimen from infected organs was performed using in situ computerized image analysis as a technological platform. Significantly elevated levels of CD3⁺ and CD8⁺ T cells as well as cells expressing interleukin (IL)-7, perforin and granulysin were found in TB lung lesions and spleen from rBCG/rAd35-vaccinated animals compared with BCG/rAd35-vaccinated or unvaccinated animals. The local increase in CD8⁺ cytolytic T cells correlated with reduced expression of the Mtb antigen MPT64 and also with prolonged survival after the challenge. Our observations suggest that a protective immune response in rBCG/rAd35-vaccinated nonhuman primates was associated with enhanced MHC class I antigen presentation and activation of CD8⁺ effector T-cell responses at the local site of infection in Mtb-challenged animals.

Predominance of G to A codon 12 mutation K-ras gene in Dukes' B colorectal cancer

INTRODUCTION

K-ras gene mutations in codons 12 and 13 are one of the earliest events in colon carcinogenesis.

METHODS

DNA was extracted from 25 mg of tumour tissue (n = 70) that were taken from tumour mass and pairs with normal epithelial tissue distant from the tumour of colorectal cancer patients. Exon 1 and exon 2 of the K-ras gene were amplified. Hotspot mutations were detected using polymerase chain reaction-based single-strand conformation polymorphism method and confirmed by direct DNA sequencing analysis.

RESULTS

Mutations were identified in 14 out of the 70 (20%) colorectal carcinoma tissues. Single-base transition from GGT to GAT (glycine to aspartate) in codon 12 was detected in nine samples, while three samples presented with GGC to GAC transition in codon 13. Patients with large adenoma had a 12-fold higher likelihood of K-ras mutations (odds ratios [OR] 12.31; 95% confidence intervals [CI] 1.81-83.76). Tumours located at the left colon were more likely to present with K-ras mutations (OR 4.54; 95% CI 0.96-21.54).

CONCLUSION

Our study showed a high frequency of G to A transition of codon 12 mutation of the K-ras gene, with significant correlation with tumour size and tumour location.

An unusual cause of confusion and hyponatraemia in an elderly patient

A large proportion of patients presenting on the acute medical take are frail and elderly and a significant proportion of these will have symptoms such as confusion, reduced mobility and electrolyte disturbances. These symptoms are typically attributed either to the iatrogenic effects of prescribed medications, disturbances in fluid balance and possible infective causes. We describe the case of a gentleman who presented with delirium, reduced mobility and hyponatraemia who was subsequently found to have pituitary failure secondary to pituitary apoplexy.

Pregnancy complicated by maternal cardiac disease: a review of 274 patients

The outcome of 274 viable pregnancies in 229 patients with cardiac disease that delivered at the King Fahad Hospital, Al-Khobar, Saudi Arabia, between 1982 and 1998 was reviewed. The incidence was 0.6% of deliveries. Rheumatic heart disease complicated 208 (75.9%) pregnancies, congenital heart lesion in 49 (17.9%) and the remaining 17 (6.2%) pregnancies were a miscellaneous group that included supraventricular tachycardia, ectopic beats, ischaemic heart disease and cardiomyopathies. The NYHA grading was between 1-2 in 243 (88.7%) pregnancies antenatally. Thirty-one patients developed heart failure, most commonly in the antenatal period, 29 of whom were of Grade 1-2. One mother in the series died from heart failure following a cesarean section. She had had a mitral valvotomy before pregnancy and was categorised as Grade 2, antenatally. The perinatal mortality rate was 14.6/1000 deliveries in the study group. Prophylactic antibiotics were given to all the patients an hour before delivery. There were two instances of bacterial endocarditis in the series.

Obstetric complications and perinatal outcome in triplet pregnancies

The incidence of multiple pregnancies with more than two fetuses has significantly increased since the introduction of ovulation agents and assisted reproductive technologies. Over a 15-year period there were 35 triplet pregnancies beyond 24 weeks that delivered at the King Fahad Hospital, an incidence of 1 in 1,099 deliveries. Early diagnosis is important for improving the rate of fetal salvage in triplet pregnancy. These pregnancies were managed on an outpatient basis. Prophylactic interventions were not utilised. A total of 91% of the pregnancies had at least one antenatal complication, pre-term labour being the most common (80%) followed by anaemia (43%). The average gestational age at delivery was 31.7 weeks (SD 4.2 weeks). A total of 94.3% of the patients were delivered by lower segment caesarean section. The mean birth weight of the neonates was 1,552 g (SD 510 g) and mean 5-min Apgar score was 7.6 (SD 0.8). The corrected perinatal mortality rate in the study was 152/1,000. Pregnancy outcome did not vary with birth order or mode of conception. Higher rate of pre-term births among triplet pregnancies make considerable demands on the neonatal intensive care unit. All methods of assisted reproduction should aim at prevention of multifetal pregnancies.

Coronary artery to pulmonary artery fistulae with multiple aneurysms: radiological features on dual-source 64-slice CT angiography

Coronary artery fistula is a rare vascular anomaly in which there is abnormal communication between the coronary artery and the great vessels or cardiac chambers. We report the case of a 66-year-old man with two separate coronary artery to pulmonary artery fistulas (one of which demonstrated multiple aneurysms), which were diagnosed on dual-source 64-slice coronary CT and reconfirmed by coronary catheter angiography.

Overexpression of WNT2 and TSG101 genes in colorectal carcinoma

Colorectal carcinoma (CRC) arises as a result of mutational activation of oncogenes coupled with inactivation of tumour suppressor genes. Mutations in APC, K-ras and p53 have been commonly reported. In a previous study by our group, the tumour susceptibility gene 101 (TSG101) were found to be persistently upregulated in CRC cases. TSG101 was reported to be closely related to cancers of the breast, brain and colon, and its overexpression in human papillary thyroid carcinomas and ovarian carcinomas had previously been reported. The wingless-type MMTV integration site family member 2 (WNT2) is potentially important in the Wnt/beta-catenin pathway and upregulation of WNT2 is not uncommon in human cancers. In this study, we report the investigation for mutation(s) and expression pattern(s) of WNT2 and TSG101, in an effort to further understand their role(s) in CRC tumourigenesis. Our results revealed no mutation in these genes, despite their persistent upregulation in CRC cases studied.

Interleukin-12p40 overexpression promotes interleukin-12p70 and interleukin-23 formation but does not affect bacille Calmette-Guérin and Mycobacterium tuberculosis clearance

Interleukin (IL)-12p40, a subunit of IL-12p70 and IL-23, has previously been shown to inhibit IL-12p70 activity and interferon-gamma (IFN-gamma) production. However, recent evidence has suggested that the role of IL-12p40 is more complex. To study the contribution of IL-12p40 to immune responses against mycobacterial infections, we have used transgenic (tg) mice overexpressing IL-12p40 under the control of a major histocompatibility complex-II promoter. The IL-12p40 transgene was expressed during steady state at concentrations of 129 +/- 25 ng/ml of serum and 75 +/- 13 ng per spleen, while endogenous IL-12p40 was hardly detectable in control littermates. Bacille Calmette-Guérin (BCG) infection strongly induced the expression of IL-12p40 transgene in infected organs, and IL-12p40 monomeric and dimeric forms were identified in spleen of IL-12p40 tg mice. Excessive production of IL-12p40 resulted in a 14-fold increase in IL-12p70 serum levels in tg mice versus non-transgenic mice. IL-23 was also strongly elevated in the serum and spleens of IL-12p40 tg mice through BCG infection. While IFN-gamma and tumour necrosis factor protein levels were similar in IL-12p40 tg and non-transgenic mice, Th2 type immune responses were reduced in IL-12p40 tg mice. The number of BCG granulomas and macrophage expressing inducible nitric oxide synthase were similar in IL-12p40 tg and non-transgenic mice. IL-12p40 tg mice were as resistant as non-transgenic mice to BCG and Mycobacterium tuberculosis infections as they could efficiently control bacillary growth. These data show that high amounts of IL-12p40 promotes IL-12p70 and IL-23 formation, but that does not affect T helper 1 type immune responses and granuloma function, thus leading to normal mycobacterial clearance in infected organs.

Design and in vitro testing of a floatable gastroretentive tablet of metformin hydrochloride

Metformin hydrochloride, which is better absorbed in the upper intestine, was formulated as a floating (buoyant) matrix tablet using a gas generating agent (sodium bicarbonate) and a gel forming hydrophilic polymer (hydroxypropyl methylcellulose). The formulation was optimized on the basis of floating ability and in vitro drug release. The resulting formulation produced robust tablets with optimum hardness, consistent weight uniformity and low tablet friability. All tablets but one exhibited satisfactory (gradual and near complete) drug release and buoyancy. In vitro drug release tests of these tablets indicated controlled sustained release of metformin hydrochloride and 96-99% released at the end of 8 h. Two formulations of fabricated tablets containing metformin hydrochloride (500 mg), sodium bicarbonate (75 mg), hydroxypropyl methylcellulose-K 4M (170-180 mg), citric acid (between 15 and 20 mg) and polyvinyl pyrrolidone K90 (32-40 mg) with hardness between 6.8 to 7.5 kg/cm2 showed a floating time of more than 8 h and promising drug release results. The release followed the Higuchi kinetic model, indicating diffusion dominated drug release.

Comparison of myeloperoxidase detection by flow cytometry using two different clones of monoclonal antibodies

INTRODUCTION

Myeloperoxidase (MPO) is present in azurophilic granules which appear in the promyelocyte stage of differentiation and is expressed in granulomonocytic cells. MPO is usually detected by cytochemistry. The demonstration of peroxidase in at least 3% of bone marrow blasts defines an acute leukaemia as acute myeloblastic leukaemia (AML). MPO is important in distinguishing acute myeloblastic leukaemia (AML) from acute lymphoblastic leukaemia (ALL). It is difficult to diagnose AML with minimal evidence of myeloid differentiation (AML- M0) by conventional light microscopy. However, these AML-M0 blasts can be detected by monoclonal antibodies. Anti-MPO recognizes the enzymatically inactive precursor forms of MPO. There are a few commercially available monoclonal antibodies against MPO. In this study, we evaluated two monoclonal antibodies against MPO from different commercial sources.

METHODS

Anti-MPO were purchased from Dako (Denmark) and Becton Dickinson, BD (California, USA). MPO detection was done using the permeabilisation-staining technique, followed by analysis with flow cytometer (FASCalibur, California, USA).

RESULTS

63 cases of acute leukaemias (38 ALL and 25 AML) were studied. Anti-MPO by Dako showed that 12/38 (31.6%) of ALL cases were positive, but all these cases were clear-cut negative for anti-MPO from BD. 24/38 (63.2%) of these ALL cases were associated with aberrant expression of myeloid antigens. However, only 8/24 (33.3%) cases with aberrant myeloid antigen expression showed positive reaction to anti-MPO (Dako). 23/25 (92%) of AML showed concordance results for both anti-MPO by Dako and BD.

CONCLUSION

Anti-MPO is a useful and reliable marker for the diagnosis of AML. However, this study had demonstrated that results vary with the monoclonal antibody used in ALL cases. Anti-MPO (Dako) had shown false positive result in 31.6% of ALL cases whereas anti-MPO (BD) had shown consistent negative result in ALL cases.

Rapid diagnosis of active tuberculosis by detecting antibodies from lymphocyte secretions

In the present study, we investigated the tuberculosis (TB) diagnostic performance of an assay on the basis of detection of TB-specific antibodies from peripheral blood mononuclear cells (PBMCs), to determine whether antibodies in lymphocyte secretions obtained from PBMCs would better reflect active disease than antibodies in serum. PBMCs from patients with and without TB cultured in various concentrations for different times were assessed. Immunoglobulin G (IgG) specific for antigen (bacille Calmette-Guérin [BCG] vaccine and purified protein derivative [PPD]) was measured in lymphocyte secretions. Patients with active TB had higher BCG- or PPD-specific IgG antibody responses than patients without TB or healthy subjects (P=.001). This method can be used as a quick diagnostic aid to facilitate rapid detection of TB cases.

Agranulocytosis--a case report

Drug induced agranulocytosis is a rare condition. Yet one hundred and five drugs have been claimed to be associated with agranulocytosis and this list has since been updated. Some drugs are associated with relatively high risk. Dapsone is one of the drugs that was associated with a sufficiently high incidence of fatal agranulocytosis. It was withdrawn from use as prophylaxis against malaria. Here we present a case of a 27 years old female who had suffered from agranulocytosis after taking Dapsone, Amitriptyline and Oflacin for treatment of Dermatitis Herpetiformis.