MRC1 and LYVE1 expressing macrophages in vascular beds of GNAQ p.R183Q driven capillary malformations in Sturge Weber syndrome

Sturge-Weber syndrome (SWS), a neurocutaneous disorder, is characterized by capillary malformations (CM) in the skin, brain, and eyes. Patients may suffer from seizures, strokes, and glaucoma, and only symptomatic treatment is available. CM are comprised of enlarged vessels with endothelial cells (ECs) and disorganized mural cells. Our recent finding indicated that the R183Q mutation in ECs leads to heightened signaling through phospholipase Cβ3 and protein kinase C, leading to increased angiopoietin-2 (ANGPT2). Furthermore, knockdown of ANGPT2, a crucial mediator of pro-angiogenic signaling, inflammation, and vascular remodeling, in EC-R183Q rescued the enlarged vessel phenotype in vivo. This prompted us to look closer at the microenvironment in CM-affected vascular beds. We analyzed multiple brain histological sections from patients with GNAQ-R183Q CM and found enlarged vessels devoid of mural cells along with increased macrophage-like cells co-expressing MRC1 (CD206, a mannose receptor), CD163 (a scavenger receptor and marker of the monocyte/macrophage lineage), CD68 (a pan macrophage marker), and LYVE1 (a lymphatic marker expressed by some macrophages). These macrophages were not found in non-SWS control brain sections. To investigate the mechanism of increased macrophages in the perivascular environment, we examined THP1 (monocytic/macrophage cell line) cell adhesion to EC-R183Q versus EC-WT under static and laminar flow conditions. First, we observed increased THP1 cell adhesion to EC-R183Q compared to EC-WT under static conditions. Next, using live cell imaging, we found THP1 cell adhesion to EC-R183Q was dramatically increased under laminar flow conditions and could be inhibited by anti-ICAM1. ICAM1, an endothelial cell adhesion molecule required for leukocyte adhesion, was strongly expressed in the endothelium in SWS brain histological sections, suggesting a mechanism for recruitment of macrophages. In conclusion, our findings demonstrate that macrophages are an important component of the perivascular environment in CM suggesting they may contribute to the CM formation and SWS disease progression.

CD45 Is Sufficient to Initiate Endothelial-to-Mesenchymal Transition in Human Endothelial Cells-Brief Report

BACKGROUND

Endothelial-to-mesenchymal transition (EndMT) is a dynamic process in which endothelial cells acquire mesenchymal properties and in turn contribute to tissue remodeling and growth. Previously, we found EndMT associated with mitral valve adaptation after myocardial infarction. Furthermore, mitral valve endothelial cells collected at 6 months post-myocardial infarction expressed the pan-leukocyte marker CD45 and EndMT markers. Additionally, mitral valve endothelial cells induced to undergo EndMT with TGF (transforming growth factor)-β1 strongly coexpressed CD45 but not CD11b or CD14. Pharmacologic inhibition of the CD45 PTPase (protein tyrosine phosphatase) domain in mitral valve endothelial cells blocked TGFβ-induced EndMT. This prompted us to speculate that, downstream of TGFβ, CD45 induces EndMT.

METHODS

We activated the endogenous CD45 promoter in human endothelial colony forming cells (ECFCs) using CRISPR (cluster regularly interspaced short palindromic repeats)/inactive Cas9 (CRISPR-associated protein 9) transcriptional activation. Bulk RNA sequencing was performed on control ECFCs and CD45-positive ECFCs to identify transcriptomic changes. Three functional assays-cellular migration, collagen gel contraction, and transendothelial electrical resistance-were conducted to assess mesenchymal properties in CD45-positive ECFCs.

RESULTS

Activation of the endogenous CD45 promoter in ECFC and 3 additional sources of endothelial cells induced expression of several genes implicated in EndMT. In addition, CD45-positive ECFCs showed increased migration, a hallmark of EndMT, increased collagen gel contraction, a hallmark of mesenchymal cells, and decreased cell-cell barrier integrity, indicating reduced endothelial function.

CONCLUSIONS

CD45 is sufficient to incite an EndMT phenotype and acquisition of mesenchymal cell properties in normal human ECFCs. We speculate that CD45, through its C-terminal PTPase domain, initiates signaling events that drive EndMT.

S2 Heart Sound Detects Aortic Valve Calcification Independent of Hemodynamic Changes in Mice

Background

Calcific aortic valve disease (CAVD) is often undiagnosed in asymptomatic patients, especially in underserved populations. Although artificial intelligence has improved murmur detection in auscultation exams, murmur manifestation depends on hemodynamic factors that can be independent of aortic valve (AoV) calcium load and function. The aim of this study was to determine if the presence of AoV calcification directly influences the S2 heart sound.

Methods

Adult C57BL/6J mice were assigned to the following 12-week-long diets: (1) Control group (n = 11) fed a normal chow, (2) Adenine group (n = 4) fed an adenine-supplemented diet to induce chronic kidney disease (CKD), and (3) Adenine + HP (n = 9) group fed the CKD diet for 6 weeks, then supplemented with high phosphate (HP) for another 6 weeks to induce AoV calcification. Phonocardiograms, echocardiogram-based valvular function, and AoV calcification were assessed at endpoint.

Results

Mice on the Adenine + HP diet had detectable AoV calcification (9.28 ± 0.74% by volume). After segmentation and dimensionality reduction, S2 sounds were labeled based on the presence of disease: Healthy, CKD, or CKD + CAVD. The dataset (2,516 S2 sounds) was split subject-wise, and an ensemble learning-based algorithm was developed to classify S2 sound features. For external validation, the areas under the receiver operating characteristic curve of the algorithm to classify mice were 0.9940 for Healthy, 0.9717 for CKD, and 0.9593 for CKD + CAVD. The algorithm had a low misclassification performance of testing set S2 sounds (1.27% false positive, 1.99% false negative).

Conclusion

Our ensemble learning-based algorithm demonstrated the feasibility of using the S2 sound to detect the presence of AoV calcification. The S2 sound can be used as a marker to identify AoV calcification independent of hemodynamic changes observed in echocardiography.

Incremental cost of venous thromboembolism in trauma patients with contraindications to prophylactic anticoagulation: a prospective economic study

Venous thromboembolism (VTE) is common in patients after major trauma. Attributable cost of VTE and whether this is related to the severity of injury have not been thoroughly investigated. We aimed to define the hospitalization costs of VTE and assess whether the costs were related to the severity of injury in this prospective economic study. Cost data of each patient enrolled in the da Vinci trial were drawn from hospital finance departments and standardized to 2020 Australian dollars (A$); and Injury Severity Score and Trauma Embolic Scoring System were used to quantify the severity of injury. Of the 223 patients who had complete financial cost data available until day-90 follow-up, 37 (16.6%) developed VTE, including upper limb (n = 3) and lower limb deep vein thrombosis (n = 25), pulmonary embolism (n = 7) and clots entrapped in a vena cava filter. The median total radiology (A$4307) as well as the hospitalization costs (A$138,526) of those who had VTE were significantly higher than those without VTE (A$1210; p < 0.001 and A$105,842; p = 0.023, respectively). The incremental hospitalization cost attributable to VTE was most apparent among those who had sustained extremely severe injuries, and estimated to be between A$43,292 (95% confidence interval [CI] 12,624-73,961, p = 0.006) and 41,680 (95%CI 7766-75,594, p = 0.016) after adjusted for Trauma Embolic Scoring System and Injury Severity Scores, respectively. VTE was common after major trauma and incurred a substantial incremental financial cost to the healthcare system, especially among those who had extremely severe injuries.

Clinicians' perceptions of medical student teaching in a tertiary hospital

BACKGROUND

Medical student placements in teaching hospitals are a cornerstone for gaining clinical experience. However, the ever-evolving nature of health care has also changed the delivery of student education. Few studies have examined clinicians' perspectives toward teaching students in this setting. We sought to explore the attitudes of clinicians involved in teaching medical students at an Australian tertiary hospital.

METHODS

Clinicians were invited by email to complete an anonymous online survey developed using a combination of questions from previously validated surveys. The questions utilized 5-point Likert scale statements and were based around the themes of "personal purpose and enjoyment of teaching" and "barriers and challenges to teaching." Results for each question are presented as frequency and percentage.

RESULTS

Of 490 invited, 67 (13.7%) consultant clinicians from various specialties responded. The majority (&gt;92%) enjoy teaching and see it as part of their work. However, approximately half thought that medical student teaching was under-recognized and half did not have adequate time to teach due to workload. Approximately 60% responded that there was insufficient time to get to know students to provide feedback and approximately 40% indicated that the scope of student knowledge and desired outcomes are not clearly defined by medical schools.

DISCUSSION

Our contemporary survey identifies modifiable factors which should be targeted. If these factors are addressed successfully, it may allow the hospital and university medical school to harness the valuable resource of clinical teachers. This could enhance the medical student experience and promote a culture of teaching and learning in hospitals.

Pigmentation Affects Elastic Fiber Patterning and Biomechanical Behavior of the Murine Aortic Valve

The aortic valve (AoV) maintains unidirectional blood distribution from the left ventricle of the heart to the aorta for systemic circulation. The AoV leaflets rely on a precise extracellular matrix microarchitecture of collagen, elastin, and proteoglycans for appropriate biomechanical performance. We have previously demonstrated a relationship between the presence of pigment in the mouse AoV with elastic fiber patterning using multiphoton imaging. Here, we extended those findings using wholemount confocal microscopy revealing that elastic fibers were diminished in the AoV of hypopigmented mice (Kit^Wv and albino) and were disorganized in the AoV of K5-Edn3 transgenic hyperpigmented mice when compared to wild type C57BL/6J mice. We further used atomic force microscopy to measure stiffness differences in the wholemount AoV leaflets of mice with different levels of pigmentation. We show that AoV leaflets of K5-Edn3 had overall higher stiffness (4.42 ± 0.35 kPa) when compared to those from Kit^Wv (2.22 ± 0.21 kPa), albino (2.45 ± 0.16 kPa), and C57BL/6J (3.0 ± 0.16 kPa) mice. Despite the striking elastic fiber phenotype and noted stiffness differences, adult mutant mice were found to have no overt cardiac differences as measured by echocardiography. Our results indicate that pigmentation, but not melanocytes, is required for proper elastic fiber organization in the mouse AoV and dictates its biomechanical properties.

Effect of rectal washout on local recurrence of rectal cancer in the era of total mesorectal excision: Meta-analysis

INTRODUCTION

Presence of intraluminal viable cancer cells implanting into the anastomosis has been proposed as a potential cause for developing local recurrence in patients undergoing anterior resection for rectal cancer. Rectal washout has been proposed as a method to prevent this from happening. There have been conflicting reports in literature regarding the effect of rectal washout on local recurrence. We aim to look at the role of rectal washout in preventing local recurrence of rectal cancer in patients undergoing total or tumor-specific mesorectal excision (TME).

MATERIALS AND METHODS

A literature review of studies evaluating the role of rectal washout on rectal cancer local recurrence was performed using PubMed, Scopus, EMBASE and non-English language literature search using CiNii (Japanese) and CNKI (Chinese). Inclusion criteria were use of TME, comparison of rectal washout with no washout, and evaluation of local recurrence as outcome.

RESULTS

Four studies were identified according to inclusion criteria. The meta-analysis showed a protective effect of rectal washout on local recurrence (OR 0.45 95% CI 0.45-0.75). However, one of the studies included had more than 90% weightage. Excluding this study from analysis showed no difference on local recurrence with rectal washout (OR 0.94, 95% CI 0.37-2.36).

CONCLUSION

The effect of rectal washout on rectal cancer local recurrence in patients who undergo TME is questionable and needs to be evaluated further by prospective studies.

Validation of the geriatric trauma outcome scores in predicting outcomes of elderly trauma patients

BACKGROUND

Using three patient characteristics, including age, Injury Severity Score (ISS) and transfusion within 24 h of admission (yes vs. no), the Geriatric Trauma Outcome Score (GTOS) and Geriatric Trauma Outcome Score II (GTOS II) have been developed to predict mortality and unfavourable discharge (to a nursing home or hospice facility), of those who were ≥65 years old, respectively.

OBJECTIVES

This study aimed to validate the GTOS and GTOS II models. For the nested-cohort requiring intensive care, we compared the GTOS scores with two ICU prognostic scores - the Acute Physiology and Chronic Health Evaluation (APACHE) III and Australian and New Zealand Risk of Death (ANZROD).

METHODS

All elderly trauma patients admitted to the State Trauma Unit between 2009 and 2019 were included. The discrimination ability and calibration of the GTOS and GTOS II scores were assessed by the area under the receiver-operating-characteristic (AUROC) curve and a calibration plot, respectively.

RESULTS

Of the 57,473 trauma admissions during the study period, 15,034 (26.2%) were ≥65 years-old. The median age and ISS of the cohort were 80 (interquartile range [IQR] 72-87) and 6 (IQR 2-9), respectively; and the average observed mortality was 4.3%. The ability of the GTOS to predict mortality was good (AUROC 0.838, 95% confidence interval [CI] 0.821-0.855), and better than either age (AUROC 0.603, 95%CI 0.581-0.624) or ISS (AUROC 0.799, 95%CI 0.779-0.819) alone. The GTOS II's ability to predict unfavourable discharge was satisfactory (AUROC 0.707, 95%CI 0.696-0.719) but no better than age alone. Both GTOS and GTOS II scores over-estimated risks of the adverse outcome when the predicted risks were high. The GTOS score (AUROC 0.683, 95%CI 0.591-0.775) was also inferior to the APACHE III (AUROC 0.783, 95%CI 0.699-0.867) or ANZROD (AUROC 0.788, 95%CI 0.705-0.870) in predicting mortality for those requiring intensive care.

CONCLUSIONS

The GTOS scores had a good ability to discriminate between survivors and non-survivors in the elderly trauma patients, but GTOS II scores were no better than age alone in predicting unfavourable discharge. Both GTOS and GTOS II scores were not well-calibrated when the predicted risks of adverse outcome were high.

The impact of COVID-19 on transfusion-dependent thalassemia patients of Karachi, Pakistan: A single-center experience

Objectives

With the advent of COVID-19 in Pakistan, the already fragmented blood transfusion services (BTS) received a severe blow, putting the lives of transfusion-dependent thalassemia children on stake. This study aimed to assess the impact of the COVID-19 on blood transfusion therapy (BTT) of thalassemia patients and suggest ways to ensure safe and reliable blood supplies amid such health crises.

Material and methods

A retrospective, cross-sectional study was conducted from October 2019 (before COVID-19) to July 2020 (during COVID-19) based on the data provided by a thalassemia center, named Help International Welfare Trust, Karachi, Pakistan. SPSS version 24.0 was used for the data analysis. Data were described in the form of means and percentages.

Results

There was a significant reduction in the consumption of PRBCs bags after the emergence of COVID-19 (P = 0.002). Moreover, the number of thalassemia patients receiving BTT was dropped by 10.56% during the pandemic. There was a strong negative correlation observed between the rising cases of COVID-19 in Pakistan and the number of patients missing their therapy sessions (r = −0.914, P = 0.030). A considerable decline in the reserves of all Rhesus-negative blood groups amid the COVID-19 outbreak was also observed.

Conclusion

The COVID-19 pandemic adversely affected the already suboptimal care catered to thalassemia patients in Karachi, Pakistan. The fear of the virus contraction coupled with the lockdown and restricted mobility has disrupted the entire transfusion chain from donor to the recipient. Collaborated efforts by the government and healthcare authorities are essential to ensure sufficient blood for thalassemia patients amid the pandemic.

Effectiveness of Laparoscopic Skills Workshop on Enhancing Knowledge and Skills of Surgical Residents and Its Comparison with DOPS (Direct Observation of Procedural Skills) Scores: Prospective Cohort Study

INTRODUCTION

Simulation-based surgical skills workshops are commonly used in the surgical training programs to enhance the knowledge and psychomotor skills of the residents, but there is scarcity of objective data on their effectiveness. The aim of our study was to explore if a 1-day laparoscopic skills workshop enhanced the knowledge and skills of surgical residents in minimal access surgery and if it had any correlation with the Direct Observation of Procedural Skills (DOPS) scores.

METHODS

This was a quasi-experimental, single-arm, repeat measure, prospective cohort study design. Thirty-three residents from general surgery and obstetrics/gynecology programs of Aga Khan University participated in the study. A daylong laparoscopic skills workshop consisting of lectures, videos, and hands-on practice was offered. The pre-workshop knowledge and skills scores of residents were assessed and compared with immediate post-workshop scores and scores of repeat assessment at 2 months. The scores of DOPS on laparoscopic procedures before and after the workshop were also compared.

RESULTS

The results of our study indicated that mean post-workshop (p < 0.001) and interval scores (p < 0.001) for both cognitive and psychomotor skills were significantly higher compared with mean pre-workshop scores. Similarly, post-workshop DOPS scores were significantly higher (p < 0.011) compared with pre-workshop DOPS scores.

CONCLUSIONS

One-day laparoscopic skills workshop resulted in significant improvement in knowledge and psychomotor skills of the surgical residents. The skills gained from the workshop also resulted in improvement of DOPS scores reflecting the transfer of skills to real-life performance.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT03982927.

Laboratory-Confirmed Metformin-Associated Lactic Acidosis

Introduction Metformin is considered the first line oral hypoglycaemic agent for the treatment of type 2 diabetes. We report three cases of prospectively identified laboratory confirmed metformin-associated lactic acidosis admitted to our intensive care unit. Case 1 72-year-old female presented with lactic acidosis; pH 6.7, lactate 22.6mmol/L with elevated Metformin levels of 4.9mg/L. Case 2 56-year-old female presented with lactic acidosis; pH 7.2 and lactate 14.8mmol/L. Metformin levels elevated at 3.9mg/L. Case 3 72-year-old female presented with lactic acidosis, pH 6.95 and lactate of 27.6mmol/L with elevated Metformin levels of 48.7mg/L. Results All three cases were admitted to the intensive care unit to receive supportive care. Despite CVVHD, two patients died. Discussion Metformin is considered the first line oral hypoglycaemic agent. Confirmation of this diagnosis often proves difficult due to the scarcity of laboratory testing. Our case series highlights the issues of inappropriate prescription in specific patient populations.

Evaluation of the trauma triage accuracy in a Level 1 Australian trauma centre

OBJECTIVES

To assess the rate of undertriage of major trauma patients and to assess factors contributing to undertriage in a modern Australian Level 1 trauma centre.

METHODS

A retrospective case series of 600 consecutive major trauma (injury severity score [ISS] >15) patients admitted to Royal Perth Hospital (RPH) during 2015 was performed. Data were compiled via the prospectively maintained hospital trauma registry for all patients admitted with a major trauma during the study period. Results were analysed for patient demographics, mechanism and outcomes. The primary outcome of the study was to determine the rate of undertriage of major trauma at RPH by establishing whether or not the trauma team activation page was correctly sent at the time of patient arrival based on hospital criteria.

RESULTS

The average age of patients in the study population was 46.5 (±21.5) years and the mean ISS was 24.7 (±9.3). The most common mechanism of injury was falls, motor vehicle accidents and motorbike accidents. One hundred and sixty-nine patients (28%) did not have trauma team activation on arrival to the ED. Among these patients, 132 did not fulfil the RPH trauma activation criteria. The remaining 37 patients (6.1%) did meet the criteria and were considered undertriaged. Subgroup analysis showed a statistically significant difference in age between the patients who had trauma team activation (42.7 ± 19.5 years) and those who did not (55.9 ± 23.3 years).

CONCLUSION

In this cohort of major trauma, a 6.1% undertriage performance of the triage tool was observed. Sub-analysis of the data showed that elderly patients were more likely to be undertriaged.

Stem Cell Cytoskeletal Responses to Pulsatile Flow in Heart Valve Tissue Engineering Studies

Heart valve replacement options remain exceedingly limited for pediatric patients because they cannot accommodate somatic growth. To overcome this shortcoming, heart valve tissue engineering using human bone marrow stem cells (HBMSCs) has been considered a potential solution to the treatment of critical congenital valvular defects. The mechanical environments during in vitro culture are key regulators of progenitor cell fate. Here, we report on alterations in HBMSCs, specifically in their actin cytoskeleton and their nucleus under fluid-induced shear stresses of relevance to heart valves. HBMSCs were seeded in microfluidic channels and were exposed to the following conditions: pulsatile shear stress (PSS), steady shear stress (SS), and no flow controls (n = 4/group). Changes to the actin filament structure were monitored and subsequent gene expression was evaluated. A significant increase (p < 0.05) in the number of actin filaments, filament density and angle (between 30° and 84°), and conversely a significant decrease (p < 0.05) in the length of the filaments were observed when the HBMSCs were exposed to PSS for 48 h compared to SS and no flow conditions. No significant differences in nuclear shape were observed among the groups (p > 0.05). Of particular relevance to valvulogenesis, klf2a, a critical gene in valve development, was significantly expressed only by the PSS group (p < 0.05). We conclude that HBMSCs respond to PSS by alterations to their actin filament structure that are distinct from SS and no flow conditions. These changes coupled with the subsequent gene expression findings suggest that at the cellular level, the immediate effect of PSS is to initiate a unique set of quantifiable cytoskeletal events (increased actin filament number, density and angle, but decrease in filament length) in stem cells, which could be useful in the fine-tuning of in vitro protocols in heart valve tissue engineering.

Serial lipase for pancreatitis: not enough evidence

BACKGROUND

Lipase is both a sensitive and specific marker for diagnosing pancreatitis. However, the benefit of serial lipase in both monitoring and defining prognosis remains undetermined. This systematic review was conducted to further evaluate this potential application. In addition, this review also looked into the benefits of serial lipase in the subgroup of traumatic pancreatitis.

METHODS

PubMed, Cochrane Library and Google Scholar were systematically searched for related articles, between January 1995 and December 2015, according to Preferred Reporting Items for Systematic Reviews and Meta-analyses standards. Data was extracted and analysed by two authors.

RESULTS

Seven studies were included in the final analysis: six retrospective and one prospective studies were identified. Five studies (all retrospective) concluded no benefits in serial lipase for prognostication, while two studies identified serial lipase as a beneficial prognostic factor for acute pancreatitis. Of the included studies, only two involved traumatic pancreatitis (both dedicated to the paediatric population).

CONCLUSION

The evidence supporting or opposing serial lipase as a prognostic factor for pancreatitis is weak and consists mainly of retrospective analyses. The only prospective data identified suggested benefits to serial lipase in prognosis. Further prospective studies evaluating the prognostic value of serial lipase in the adult population with both traumatic and non-traumatic pancreatitis are required given the paucity of available evidence.

A "sweet-spot" for fluid-induced oscillations in the conditioning of stem cell-based engineered heart valve tissues

Fluid-induced shear stresses are involved in the development of cardiovascular tissues. In a tissue engineering framework, this stimulus has also been considered as a mechanical regulator of stem cell differentiation. We recently demonstrated that the fluid-oscillating effect in combination with a physiologically-relevant shear stress magnitude contributes to the formation of stem cell-derived de novo heart valve tissues. However, the range of oscillations necessary to induce favorable gene expression and engineered tissue formation is unknown. In this study, we took a computational approach to establish a range of oscillatory shear stresses that may optimize in vitro valvular tissue growth. Taking a biomimetic approach, three physiologically-relevant flow waveforms from the human: (i) aorta, (ii) pulmonary artery and (iii) superior vena cava were utilized to simulate pulsatile flow conditions within a bioreactor that housed 3 tissue specimens. Results were compared to non-physiological pulsatile flow (NPPF) and cyclic flexure-steady flow (Flex-Flow) conditions. The oscillatory shear index (OSI) was used to quantify the fluid-induced oscillations occurring on the specimen surfaces. The range of mean OSI under the physiological conditions investigated was found to be 0.18 ≤ OSI ≤ 0.23. On the other hand, NPPF and Flex-Flow environments yielded a mean OSI of 0.37 and 0.11 respectively, which were 46% higher and 45% lower than physiological conditions. Moreover, we subsequently conducted OSI-based human bone marrow stem cell (HBMSC) culture experiments which resulted in preferential valvular gene expression and phenotype (significant upregulation of BMP, KLF2A, CD31 and α-SMA using an OSI of 0.23 in comparison to a lower OSI of 0.10 or a higher OSI of 0.38; p < .05). These findings suggest that a distinct range or a "sweet-spot" for physiological OSI exists in the mechanical conditioning of tissue engineered heart valves grown from stem cell sources. We conclude that in vitro heart valve matrix development could be further enhanced by simultaneous exposure of the engineered tissues to physiologically-relevant magnitudes of both fluid-induced oscillations and shear stresses.

Surgical management of inflammatory bowel disease: A low prevalence, developing country perspective

OBJECTIVE

To determine the outcomes of surgical management of inflammatory bowel disease.

METHODS

The retrospective case series was conducted at Aga Khan University Hospital, Karachi, and comprised medical record of adult patients operated between January 1986 and December 2010 for inflammatory bowel disease. Outcomes consisted of complications till last follow-up and 30-day mortality (disease or procedure related). Functional status of patients with ileal pouch was determined via telephone. SPSS 16 was used to analyse data.

RESULTS

Of the 36 patients whose records were reviewed, 21(58%) were males, and body mass index was less than 23 in 34(91%). A total of 27(75%) patients underwent elective surgery for their condition. Ileal pouch was formed in 9(25%). Overall mortality was 14(38.8%). Overall incidence of complications was 26(72%), with wound infection being the most common early morbidity in 11(30.5%). Late morbidity included pouchitisin 4/9 (44.9%) and strictures 2/36 (5.5%).On telephonic follow-up, 6 of the remaining 7patients (85%) with ileal pouch were satisfied with the functional results of the procedure.

CONCLUSIONS

The retrospective case series represents results from a developing country with low prevalence of inflammatory bowel disease and hence limited experience.

P4-01-04: Effects of CYP2D6 Phenotype and Drug Adherence on Tamoxifen Metabolite Levels

Background

Although the activity of cytochrome P450 2D6 (CYP2D6), the enzyme responsible for conversion of tamoxifen (TAM) to its most important active metabolite endoxifen, varies significantly with genotype. Routine genotype testing in patients on TAM has recently been discouraged. Conflicting results in publications regarding the prognostic utility of this test remain unexplained. Confounding factors could be lack of predicted correlation between CYP2D6 genotype and TAM active metabolites, or variability of patient compliance

Methods: Consecutive breast cancer patients on TAM were asked to enroll in a study to examine the relationship between CYP 2D6 phenotype, patient-reported treatment adherence, and TAM metabolites levels. Patients were genotyped for CYP2D6 polymorphisms using long-range PCR allele-specific amplification and single-nucleotide primer extension assay. From the genotypes, four phenotype groups were defined: Ultra rapid Metabolizer (UM), Extensive Metabolizer (EM), Intermediate Metabolizer (IM) and Poor Metabolizer (PM). Plasma was collected after at least 6 weeks of TAM (20 mg daily). The parent drug TAM, as well as 4-hydroxy N-desmethyl tamoxifen (endoxifen), 4 hydroxy tamoxifen (4OHtam) and N-desmethyl-tamoxifen (NDtam), were determined by Liquid Chromatography tandem mass-spectrometry (LC-MS/MS). Patients also completed a questionnaire about ethinicity, side effects, concurrent medications and tamoxifen adherence. Correlation between metabolite/TAM ratio and phenotype was tested by Spearman correlation test. Relationship between metabolite levels and adherence was tested by Wilcoxon rank sum test. Chi square test was used to compare proportions.

Results: Of the 100 patients enrolled there were 62 Caucasians, 25 Asians, 4 Africans and 6 Unknown. We found a strong correlation between ratio of endoxifen/TAM and phenotype (p &lt;.0001) (Table 1) Over a 2 week period 68 never missed a TAM dose, 25 missed 1–2 times, 2 missed 3–5 times and 2 &gt; 5times (2 missing data). In EM group we found significantly lower levels of TAM (p &lt;.0001), NDtam (p=.008), 4OHtam (p=.003) in less adherent patients. A trend to decreased levels was also shown for endoxifen (p=.081). No associations were found between adherence or phenotype activity and side effects.

Pancreaticoduodenectomy: a developing country perspective

OBJECTIVE

To review retrospectively, the resultsof Whipple's procedure from 1986 to December 2009 at the Aga Khan University Hospital.

METHODS

Patient's case notes were reviewed to extract information related to demographics, clinical and laboratory data, operative procedure and post operative period. Surgical mortality was defined as death within 30 days of procedure.

RESULTS

Hundred and twenty one patients underwent a successful pancreaticoduodenectomy during this period. There were 78 males and 43 females. Most presented with clinical features of obstructive jaundice. Perioperative evaluation in the majority included an abdominal ultrasound and contrast enhanced CT scan. A preoperative ERCP was performed in 64 (53%) patients and a stent was placed in 32 (26%). Stent related sepsis was noted in 8 patients (25%). Eighty four (69%) patients underwent a standard resection, 31% had a pylorus preserving procedure. The commonest pathology was adeno-carcinoma located in the pancreatic head or periampullary area. Post operative morbidity was noted in 54% of patients, the commonest being chest infection (20%) followed by delayed gastric emptying and pancreatic anastomotic leak. There were 12 perioperative deaths giving a surgical mortality of 10%.

CONCLUSION

To our understanding this is the largest series of consecutive pancreaticoduodenectomies reported in Pakistan. Our morbidity and mortality rates compare favourably with international centers of similar yearly case volume. There is a need to establish regional centers to effectively manage complex disease conditions and improve the standard of care offered to our patients.

Abstract P6-12-01: A Meta Analysis of Risk of Cardiovascular Events in Patients with Metastatic Breast Cancer (MBC) Treated with Anti Vascular Endothelial Growth Factor (VEGF) Therapy — Bevacizumab

Background and objectives: Bevacizumab, used in combination with chemotherapy has demonstrated efficacy in randomized trials in MBC. Hypertension, congestive heart failure and cardiomyopathy have been reported in trials of bevacizumab in breast cancer. The aim of this systematic review and meta analysis is to determine the overall risk of grade 3-4 hypertension (HTN), left ventricular dysfunction (LVD) and venous (VT) and arterial thromboembolic events (ATE) related to Bevacizumab in patients with MBC.

Methods: We selected randomized phase III trials which compared chemotherapy with or without bevacizumab in MBC as first or second line therapy. Data extraction was carried out from results published in the literature or from conference proceedings of the selected studies. For the analysis, we used a fixed-effects and random effects models to calculate the pooled event-based relative risk ratios (RR) with 95% confidence interval (CI). The Cochran's Q statistic and I2 statistics were first calculated to assess the heterogeneity among the proportions of the included trials. We collected all grade 3-4 events reported in these trials in relation to cardiovascular events: HTN, LVD, congestive heart failure, cardiomyopathy, VT and ATE.

Results: Five trials were included in the meta-analysis: E2100, AVADO, RIBBON-1, RIBBON-2 and Miller et al study (capecitabine alone or plus bevacizumab in previously treated MBC). In total 2126 patients received chemotherapy in combination with bevacizumab and 1444 chemotherapy alone. When there was tendency for heterogeneity, random-effects models were used. Thromboembolic events were pooled together as VT and ATE as information was not clear in some of the reported studies. CHF and cardiomyopathy were considered for LVD events in the Miller study as LVD was not reported. Patients treated with bevacizumab-containing regimens had a RR for HTN of 10.32 (95% CI, 4.23- 24.79; p&lt;.0001), RR for LVD 2.58 (95% CI, 1.06 - 6.32; p=0.04) and RR for VT and ATE of 1.71 (95% CI, 0.81- 3.60; p=0.16) as shown in figure 1.

Conclusion: HTN is a recognized side effect of bevacizumab therapy. The risk of LVD is also significantly higher with bevacizumab therapy (RR 2.58) as shown in this pooled analysis, but the risk of thrombotic events is not increased.

Figure available in online version.

Evaluation of therapeutic control in a Pakistani population with hypertension

RATIONALE, AIMS AND OBJECTIVES

Cardiovascular diseases (CVD) are increasing at an alarming rate in South Asia. High blood pressure is a modifiable risk factor for CVD. In this study, we evaluated the control of blood pressure and the prevalence of cardiovascular risk factors in patients with hypertension.

METHOD

A cross-sectional study was conducted in 50 primary health care centres throughout Pakistan. Individuals with a documented history of hypertension, receiving pharmacological therapy, were enrolled and evaluated for the control of their blood pressure.

RESULTS

The recommended therapeutic control of hypertension (systolic blood pressure <140 mmHg, diastolic blood pressure <90 mmHg) was seen in only 6.4% of the study participants. Values of both the mean systolic and diastolic blood pressures in all subjects were higher than the desired therapeutic levels (P<0.001). There was a high prevalence in the study population of established but modifiable risk factors of CVD, such as smoking (30.5%), hypercholesterolemia (59.5%) and sedentary lifestyle (43.5%). Lack of therapeutic control of systolic blood pressure was found significantly associated with age, hypercholesterolemia and sedentary lifestyle (P<0.05).

CONCLUSIONS

Patients being treated at primary health care centres in Pakistan have inadequate control of high blood pressure. Evidence-based continuous education of primary health care physicians is a necessary intervention for optimizing treatment strategies and achieving better therapeutic control of hypertension in our population.

The Pakistan Risk of Myocardial Infarction Study: a resource for the study of genetic, lifestyle and other determinants of myocardial infarction in South Asia

The burden of coronary heart disease (CHD) is increasing at a greater rate in South Asia than in any other region globally, but there is little direct evidence about its determinants. The Pakistan Risk of Myocardial Infarction Study (PROMIS) is an epidemiological resource to enable reliable study of genetic, lifestyle and other determinants of CHD in South Asia. By March 2009, PROMIS had recruited over 5,000 cases of first-ever confirmed acute myocardial infarction (MI) and over 5,000 matched controls aged 30-80 years. For each participant, information has been recorded on demographic factors, lifestyle, medical and family history, anthropometry, and a 12-lead electrocardiogram. A range of biological samples has been collected and stored, including DNA, plasma, serum and whole blood. During its next stage, the study aims to expand recruitment to achieve a total of about 20,000 cases and about 20,000 controls, and, in subsets of participants, to enrich the resource by collection of monocytes, establishment of lymphoblastoid cell lines, and by resurveying participants. Measurements in progress include profiling of candidate biochemical factors, assay of 45,000 variants in 2,100 candidate genes, and a genomewide association scan of over 650,000 genetic markers. We have established a large epidemiological resource for CHD in South Asia. In parallel with its further expansion and enrichment, the PROMIS resource will be systematically harvested to help identify and evaluate genetic and other determinants of MI in South Asia. Findings from this study should advance scientific understanding and inform regionally appropriate disease prevention and control strategies.

The impact of a contaminated city water supply on an emergency department

In March 2007 Galway City and County's water supply was officially contaminated by cryptosporidiosis. The medical and nursing staff at the city's only Emergency Department had noted a rise in an atypical form of gastroenteritis in the preceding months. A retrospective audit of 11,723 charts from January 1st 2007 to 22nd March (day after contamination was confirmed) was performed to identify these patients. The number of potential gastroenteritis cases was 185 (incidence 1.6%), with a peak five weeks before the outbreak was confirmed. Half the patients were aged between 20 and 34. Pain (80%), nausea or vomiting (74%) and diarrhoea (66.5%) were the most frequent symptoms. The mean duration of symptoms at presentation was 2 days. Stool samples were sent for nine patients and four of these were tested for Cryptosporidium. Over a quarter (28.6%) of patients were admitted and almost three-quarters (69.7% +/- 7%) had a residential address in the affected area. Difficulty exists in the early identification of new outbreaks and many of the affected patients are not detected using routine surveillance or current capture methods.

Attitudes towards genetic diagnosis in Pakistan: a survey of medical and legal communities and parents of thalassemic children

OBJECTIVES

It was the aim of this study to assess the attitudes of doctors, medical students, lawyers, parliament members and parents of thalassemic children towards genetic diagnosis in Pakistan.

STUDY DESIGN

A cross-sectional descriptive survey was conducted among representative samples.

RESULTS

Five hundred and seventy doctors, 49 lawyers, 178 medical students, 89 parents of thalassemic children and 16 members of parliament (MPs) were included in the survey. The groups showed considerable difference in their attitudes towards different aspects of the issue. A large proportion (88.5%) agreed to the idea of genetic diagnostic screening, especially the parents of thalassemic patients. Premarital carrier screening was favored by 77% of the respondents. Prenatal screening was most favored by the parents of thalassemic children (94.4%). Likewise, a majority of parents of thalassemic children were in favor of abortion in case of an affected fetus. Genetic self-screening was also favored most by the parents of thalassemic patients (78.2%). Only 24% of the doctors favored making genetic screening mandatory, whereas 63% of the parents agreed to the idea.

CONCLUSION

Attitudes regarding genetic diagnosis are markedly different among various societal groups in Pakistan. The parents of the affected children strongly favor genetic screening as does the medical community, though not as strongly as the parents. The legislative groups, particularly the MPs, are reserved in their support. Genetic diagnosis can help decrease the disease burden in the future. However, it raises a number of ethical issues, which need to be addressed. It is important to educate the population about potential benefits as well as ethical dilemmas involved so that the general public is able to make the right decisions for themselves and their families.

Patterns of participation of patients in cancer clinical trials in Ireland

BACKGROUND

In the United States the overall participation in cancer clinical trials (CCT) is less than 3% [Avis et al. in J Clin Oncol 24:1860-1867 (2006); Lara et al. in J Clin Oncol 19:1728-1733 (2001)]. In Europe there is little data on participation in such trials.

AIM

We aim to gather information on factors influencing CCT enrolment in Ireland.

METHODS

From November 2005 to 28 February 2006 all consecutive patients considered for systemic therapy were assessed for eligibility re participation in available CCTs.

RESULTS

A total of 290 patients were included. Overall 2.4% of patients were recruited to one of the available CCTs. The main reasons for failure of trial recruit were: no trial for cancer type (60%), no trial for stage (21%), ineligible by trial criteria (16.1%), patient declined (0.3%), and physician discretion (2.6%). Only one patient, who was otherwise eligible, declined entry into a clinical trial.

CONCLUSIONS

Irish patients with cancer are very willing to participate in CCTs. Current levels of recruitment compare favourably with international levels.

Febrile neutropenia in paediatric peripheral blood stem cell transplantation, in -vitro sensitivity data and clinical response to empirical antibiotic therapy

OBJECTIVE

To find the in-vitro sensitivity data and clinical response in order to determine the changes required in empiric antibiotic therapy for management of febrile neutropenia in paediatric patients undergoing peripheral blood stem cell transplantation.

DESIGN

A descriptive study.

PLACE AND DURATION OF STUDY

Paediatric bone marrow transplant unit at Bismillah Taqee Institute of Health Sciences and Blood Disease Center from September 1999 to May 2004.

PATIENTS AND METHODS

All patients were treated according to institutional protocol for febrile neutropenia. Empirical antibiotics include Ceftriaxone and Amikacin. In non-responders, changes made included Imipenem and Amikacin, Piperacillin Tazobactum/Tiecoplanin or Vancomycin/Cloxacilin/Ceftazidime. In non-responders, amphotaracin was added until recovery.

RESULTS

Out of 52 patients, 5 did not develop any fever; in the remaining 47 patients there were 57 episodes of febrile neutropenia. The mean days of febrile episodes were 4.71 (range 3-8). Fever of unknown origin (FUO) occurred in 31 (54.3%) episodes. Microbiologically documented infection (MDI) occurred in 17 (29.8%) episodes of fever. Clinically documented infection (CDI) occurred in 9 (15.7%) episodes. Gram-negative organisms were isolated in 10 while gram-positive organisms in 7. Klebseilla, S. aureus were the most common isolates. Empirical therapy was effective in 12 of the 33 (36%) episodes. Out of 28, 26 (92%) responded to Imipenem/Amikacin as second line therapy while those who received any other second line combination, only 11 out of 22 (50%) showed response. Systemic Amphotericin was used in 4 patients, 2 responded. Infection related mortality rate was 4%.

CONCLUSION

Gram-negative infections predominated, Imipenem/ Amikacin found to be most effective therapy while a low mortality rate is recorded in our setting suggesting good infection control.

Proteinchip(R) surface enhanced laser desorption/ionization (SELDI) mass spectrometry: a novel protein biochip technology for detection of prostate cancer biomarkers in complex protein mixtures

Improving early detection, diagnosis, treatment monitoring and prognosis of cancer will require rapid and high throughput detection, identification, and measurement of multiple biomarkers. In this study, we demonstrate the versatility of the innovative SELDI ProteinChip(R) MS technology for the rapid, reproducible and simultaneous identification of four well-characterized prostate cancer-associated (PCA) biomarkers, prostate specific antigen (free and complexed forms), prostate specific peptide, prostate acid phophatase and prostate specific membrane antigen in cell lysates, serum and seminal plasma. Proteins corresponding to the mass of these biomarkers could readily be captured and detected using either chemically defined or antibody coated ProteinChip(R) arrays. Several (yet to be identified) proteins were found upregulated in cell lysates of pure populations of PCA cells procured by laser capture microdissection (LCM) when compared with mass spectra of normal cell lysates. Coupling LCM with SELDI provides tremendous opportunities to discover and identify the signature proteins associated with each stage of tumor development. Collectively, these observations demonstrate the potential of SELDI for the discovery and simultaneous detection of and clinical assay development for PCA biomarkers in complex biological mixtures.

Correlations between p21 expression and clinicopathological findings, p53 gene and protein alterations, and survival in patients with endometrial carcinoma

The p21 protein inhibits cyclin-dependent kinases and mediates cell-cycle arrest and cell differentiation. It is induced by wild-type p53, but not by mutant p53. This study of 75 patients with endometrial carcinoma investigates the relationship between p21 expression and the functional status of p53, and the usefulness of p21 as a prognostic marker. Correlations were determined between p21 immunoreactivity, p53 overexpression as examined by immunohistochemistry, p53 DNA mutations as examined by polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) analysis, and clinicopathological features, including the clinical outcome. Immunoreactivity for p21 and p53 mutations were detected in 47 (62.7 per cent), 37 (49 per cent), and 23 (31 per cent) patients, respectively. There were no significant correlations between the presence or absence of p21 immunoreactivity and p53 overexpression and DNA mutations. Survival curves revealed that patients with p53 overexpression tended to have a poorer prognosis than those without p53 overexpression (P = 0.104), that patients with p53 mutations had a significantly worse prognosis than those without mutations (P = 0.035), and that patients with p21 expression tended to have a better prognosis than those without p21 expression (P = 0.074). Immunohistochemical analysis of p21 was not useful for evaluating the functional status of p53 in patients with endometrial carcinoma. Both p21 expression and p53 abnormalities were considered as prognostic indicators in patients with endometrioid endometrial carcinoma.

K-ras point mutations in endometrial carcinoma: effect on outcome is dependent on age of patient

Mutations involving the K-ras proto-oncogene are believed to play an important role in the mechanism of tumorigenesis for many human cancers and occur in 10-30% of endometrial carcinomas. In the present study 221 cases of endometrioid endometrial carcinoma obtained from Japanese patients with average follow-up of 41 months were examined for point mutations in codon 12 of K-ras through use of the polymerase chain reaction. In 103 cases lymph node dissection had been performed. K-ras mutations were significantly associated with the presence of lymph node metastases (P < 0.04). Since endometrial carcinoma in premenopausal women generally behaves less aggressively than tumors of similar histologic grade arising in postmenopausal patients, we evaluated the effect of K-ras mutation on outcome in patients stratified into three different age categories (<53 years, premenopausal; 54-59 years, perimenopausal; >60 years, postmenopausal). In the postmenopausal age group (>60 years), the presence of K-ras mutations was statistically significantly associated with patients who died or experienced recurrence (41.2% vs 13.0%; P < 0.03). This was related to a dramatic (greater than eightfold; P = 0.011) increase in the likelihood of adverse outcome between the premenopausal and postmenopausal states for patients whose tumors contained mutant K-ras. These findings point to a possible role for K-ras activation in the mechanism(s) responsible for more aggressive clinical behavior of endometrioid endometrial cancer that is observed in postmenopausal patients.

Rhabdoid cells in peritoneal fluid. A case report

BACKGROUND

Rhabdoid tumor is an aggressive, malignant renal neoplasm of infants. Many extrarenal sites have been documented.

CASE

A poorly differentiated carcinoma of the ovary with rhabdoid features occurred in a 36-year-old woman. The peritoneal fluid contained numerous malignant cells with rhabdoid features. Electron microscopy and immunocytochemistry corroborated the rhabdoid nature of the cells.

CONCLUSION

Rhabdoid cells can be distinguished from other neoplasms with similar cytologic features by ancillary studies and clinical history.

Genetics of colorectal and breast cancer

Colorectal and breast cancers account for a significant number of deaths due to malignant neoplasia. Laboratory medicine plays an important role in the diagnosis and management of these tumors through the application of histopathology, immunohistochemistry, and serologic identification of tumor markers. Approximately 5% to 10% of colorectal and breast cancers result from an inherited predisposition. The genes responsible for most genetically transmitted cancers have been identified, and the application of findings from molecular pathology are being evaluated. This article reviews the genetic changes that occur as a result of somatic mutation and inherited or germline mutations.

High incidence of point mutation in K-ras codon 12 in carcinoma of the fallopian tube

BACKGROUND

Adenocarcinoma of the fallopian tube is a rare tumor with a poor prognosis. Whether these carcinomas possess any genetic changes that contribute to their malignant behavior is unknown and to date few studies regarding the molecular pathogenesis of these tumors have been reported. In adenocarcinoma of the endometrium, mutations in the first exon of K-ras, although relatively infrequent, were observed to be an independent risk factor for poor clinical outcome.

METHODS

Eight patients with adenocarcinoma of the fallopian tube were examined for mutations in the 12th codon of K-ras. DNA was obtained from single sections of paraffin embedded tumor tissue and the first exon of K-ras was amplified by the polymerase chain reaction. Point mutations were assayed using a nonradioactive restriction fragment length polymorphism technique.

RESULTS

The eight patients in this study varied in clinical stage from I-IV and were all treated with surgery and chemotherapy. Six of eight of the patients died and one of the surviving patients had metastases in the vertebrae. K-ras point mutations were detected at codon 12 in seven of the eight tumors (87.5%).

CONCLUSIONS

K-ras mutations occurred with high frequency in this series of eight patients with fallopian tube carcinoma, suggesting that mutations of this protooncogene could play an important role in the molecular pathogenesis of this lesion.

Ras oncogene activation during hepatocarcinogenesis in B6C3F1 male mice by dichloroacetic and trichloroacetic acids

Dichloroacetic (DCA) and trichloroacetic (TCA) acids, two major by-products formed during chlorine disinfection of drinking water, increase the incidence of tumors in B6C3F1 mice by 6- and 3-fold respectively. In order to understand better the mechanism by which these two compounds induce liver tumors, the incidence and spectrum of mutations in the K- and H-ras proto-oncogenes in these tumors were analyzed. DNA from spontaneous, DCA- and TCA-induced liver tumor from B6C3F1 male mice was evaluated for point mutations in exons 1, 2 and 3 of the two genes by single-stranded conformation polymorphism. Results demonstrated a similar incidence of mutations for exon 2 of H-ras in spontaneous carcinomas (58%), and in carcinomas induced by DCA 3.5 g/l (50%), 1.0 g/l (48%) and TCA 4.5 g/l (45%). Only four showed mutations in the other exons of Hras or in K-ras. Sequence analysis of spontaneous tumor samples with second exon H-ras mutations revealed a change in codon 61 from CAA to AAA in 80% and CAA to CGA in 20% of tumors. In contrast, tumors with H-ras mutations from DCA-treated mice revealed a H-61 change from CAA to AAA in 21% at 3.5 g/l and 16% at 1.0 g/l. CAA to CGA was observed in 50% of tumors from mice given DCA 3.5 or 1.0 g/l, and CAA to CTA was present in 29% and 34% of the two dosage groups respectively. Interestingly, TCA showed the same mutational spectrum as the spontaneous liver tumors. The data indicates that induction of liver carcinoma by DCA and TCA involves activation of the H-ras proto-oncogene at a frequency similar to that observed in spontaneous tumors. However, the mechanism(s) for including hepatocellular carcinoma does not appear to be identical for DCA and TCA.

Comparison of PCR with southern hybridization for the routine detection of immunoglobulin heavy chain gene rearrangements

The development of a reliable polymerase chain reaction (PCR) technique for the routine detection of clonal immunoglobulin heavy chain (IgH) gene rearrangements would represent an attractive alternative to Southern hybridization analysis because of the relative simplicity of PCR protocols, and because the requirements for both quality and quantity of DNA would be considerably less stringent. To assess the utility of PCR for the routine detection of clonal IgH gene rearrangements, samples from 123 adult patients were evaluated and analysis by PCR amplification using IgH Framework 1 or Framework 3 variable region consensus primers was compared with analysis by restriction endonuclease digestion and Southern hybridization with genomic, IgH probes. The authors found that 90% of IgH genes found to be rearranged by Southern hybridization are detected by the PCR technique. An additional 9 patient samples had clonal IgH gene rearrangements that were detectable by PCR alone. Eight of these nine patients had a history of a clonal hematopoietic process at either the morphologic or molecular level, and six had a history of a B-cell malignancy. It is likely that these specimens contained clonal lymphoid populations undetected by the Southern hybridization technique. Thus, the diagnostic sensitivity and specificity of the PCR method for the detection of B-cell tumors were 91% and 95%, respectively. The combination of improved analytical sensitivity and specimen flexibility of the IgH PCR assay could make it the method of choice for the routine detection of clonal IgH gene rearrangements, if minor improvements in the diagnostic sensitivity of the assay can be achieved.

Prognostic significance of p53 overexpression in endometrial cancer

Abnormalities of p53, a tumor suppressor gene, have been considered to play an important role in tumorigenesis. Clinically, overexpression of p53 has been reported to correlate with poor prognosis in several types of tumors. In this study, we examined 221 cases of endometrioid endometrial carcinoma for overexpression of p53 using immunohistochemistry in patients with a median follow-up of 41 months. Immunohistochemical analysis was performed with monoclonal antibody pAb1801. Overexpression of p53 was detected in 47 of 221 cases (21.3%). There was a statistically significant correlation between p53 overexpression and poor prognosis (P < .0001). In the early stages of cancer (stages 1 and 2), p53 was overexpressed in 11 of 22 patients (50%) who died or had a recurrence during follow-up. In contrast, overexpression was detected in only 14.7% of the 156 disease-free patients during the same period (P < .0001). In advanced stages (stages 3 and 4), tumors from patients with recurrent disease had a higher frequency of overexpression (41.2%; 7 of 17) than those of disease-free patients (23.1% 6 of 26). However, the difference between these frequencies was not statistically significant. In multivariate analysis using the Cox proportional hazard model, p53 overexpression was an independent risk factor when compared with clinical stage, nuclear grade, and patient age. Our results indicate that p53 immunohistochemical evaluation of the most common form of endometrial cancer may be useful in identifying cases of aggressive carcinoma, especially in the early stages.

Sequential analysis of K-ras mutations in aberrant crypt foci and colonic tumors induced by azoxymethane in Fischer-344 rats on high-risk diet

Forty Fischer-344 male rats were given a high-risk diet (HRD) that was high in fat, low in fiber and low in calcium. After 4 weeks, the rats were given two weekly s.c. injections of azoxymethane (AOM, 15 mg/kg body wt), and remained on the same diet till death. Eight rats were killed at 12 weeks and again at 20 weeks in order to microdissect aberrant crypt foci (ACF) containing four or more crypts/focus from their colons. The remaining 24 rats were killed at 30 weeks to harvest colonic tumors. The polymerase chain reaction (PCR) was used to amplify specific DNA segments in the K-ras gene from ACF and colonic tumors. The PCR-amplified DNAs were sequenced to identify the point mutations in codons 12 and 13. All the mutations detected in the ACF and colonic tumors were G to A transitions in the second position of codon 12. These mutations were present in the ACF of 2/8 (25%) and 3/8 (37%) rats at 12 and 20 weeks respectively. The mutations were present in colonic tumors of 7/24 (29%) rats. These results provide important evidence for the significance of K-ras mutations in ACF (> 4 crypts/focus) as early markers of malignant potential in the colons of F344 rats exposed to AOM while receiving a high-risk western style diet.

Clinical implications of K-ras mutations in malignant epithelial tumors of the endometrium

Tumorigenesis in humans and experimental animals appears to involve the activation of ras protooncogenes for a number of organ systems and seems to be important to the development of the metastatic phenotype in several model systems. Clinically, the presence of activated ras protooncogenes has been reported to be a negative prognostic factor in the myelodysplastic syndrome and in adenocarcinoma of the lung. In the present study we examined 49 cases of endometrial carcinoma for mutations in the first exon of K-ras using the polymerase chain reaction and direct sequencing. Mutations in codon 12 or 13 of K-ras were detected in 6 of 49 cases (12.2%). These six cases consisted of five endometrioid endometrial carcinomas, each of which had a mutation in codon 12, and one case of clear cell carcinoma, which had a mutation in codon 13. In our study the presence of mutations in K-ras appeared to be an unfavorable prognostic factor. Three of six patients with the mutation died during follow-up, while only 7% of the 43 patients without K-ras mutations expired during this same period. In multivariate analysis using the Cox proportional hazard model, K-ras activation appeared to be an independent risk factor when compared with clinical stage, depth of myometrial invasion, and patient age. Thus, our findings support the hypothesis that K-ras protooncogene activation plays an important role in determining the aggressiveness of endometrial carcinoma.

Cardiac myocytes and dendritic cells harbor human immunodeficiency virus in infected patients with and without cardiac dysfunction: detection by multiplex, nested, polymerase chain reaction in individually microdissected cells from right ventricular endomyocardial biopsy tissue

Two hundred fifteen patients infected with human immunodeficiency virus (HIV) participated in a prospective longitudinal study of HIV-related heart disease. Evaluation included signal-averaged electrocardiography and echocardiography. Fifteen patients underwent endomyocardial biopsy, 5 had cardiovascular symptoms and 10 did not. Cardiac myocytes or dendritic cells were prepared by individual cell microdissection to sort them from other cell types such as interstitial cells or circulating blood elements. HIV proviral sequences were amplified in samples of 15 to 20 cells of each type by multiplex, nested, polymerase chain reaction and hybridized to 32P-labeled probes specific for regions within the gag and pol genes of HIV-1. The results showed the presence of HIV sequences in myocytes of 2 of 5 patients with cardiac symptoms and in 6 of 10 without. Thus, symptomatic HIV cardiomyopathy did not appear to be a direct consequence of the virus on myocardial cells. In dendritic cells, HIV sequences were detected in 5 of 5 patients with cardiac symptoms and in 8 of 10 with apparently normal ventricular function. Furthermore, dendritic cells were somewhat more numerous in the myocardium of symptomatic than asymptomatic patients. Our studies are the first to directly detect the HIV genome in purified cardiac myocytes from patients with and without cardiac dysfunction. Our findings do not support a direct role of the virus in myocardial dysfunction. However, the results do suggest that the interstitial dendritic cells may be involved in some manner in the development of cardiac dysfunction observed in HIV-infected patients.

Comparison of sensitivity for human cytomegalovirus of the polymerase chain reaction, traditional tube culture and shell vial assay by sequential dilutions of infected cell lines

Although traditional tube culture (TTC) is still considered by many as the 'gold standard' for the laboratory diagnosis of human cytomegalovirus (HCMV), the shell vial assay (SVA) offers greater speed of detection. This technique utilizes immunofluorescence (IF) to detect early or immediate early nuclear antigens (IEA). The detection capabilities of these two tests were compared with the polymerase chain reaction (PCR), a technique that amplifies enzymatically selected DNA target sequences. Serial dilutions of crude culture harvests from 2 HCMV strains, Towne and a clinical urine isolate, were made up to 1:1 000,000. Ten-microliters aliquots of the original sample and each dilution were tested by PCR, TTC and SVA. For PCR, the nested-primer approach was used. Outer primers delimited a 721-bp sequence contained within the 2nd to 4th exons of the immediate-early protein. Inner nest primers delimited a 167-bp sequence in the third exon, detected by a 32P-labelled probe. The results show that: (1) control samples which contained all PCR reagents but no DNA were uniformly negative; (2) radiolabelled-probe detection (RPD) of PCR products is, on average, 100 x more sensitive than detection by ethidium bromide; (3) PCR is, on average, 100 x more sensitive than evaluation of cytopathic effect (CPE) in the TTC; (4) the predictive value of a negative SVA result is low compared to PCR.

Nested polymerase chain reaction assay for the detection of cytomegalovirus overcomes false positives caused by contamination with fragmented DNA

The polymerase chain reaction (PCR) technique offers a promising alternative to tissue culture for the rapid and sensitive detection of cytomegalovirus (CMV) infection. However, high levels of background amplification detected in samples containing water but no DNA make interpretation of borderline positive samples extremely difficult and reduce the sensitivity of the assay. The signal from amplification of water or positive samples can be eliminated by DNase treatment, but not by filtration through anisotropic membrane, autoclaving, or ultraviolet irradiation. A lag time of 10 to 12 cycles is observed before the reactions with water will show product formation by liquid hybridization detection. The use of nested PCR eliminates the background and, in serial dilutions of a positive sample, shows a 500- to 1000-fold increase in sensitivity by liquid hybridization detection. We suggest that the background signal is arising from small fragments of DNA, which may be produced by autoclaving viral culture material. Such fragments would escape filtration, and overlapping fragments of DNA can prime one another to form complete mosaic sequences that will then amplify. Nested PCR, appropriately controlled for the number of cycles at each step, should successfully overcome such false positives caused by fragmented DNA, no matter if the contamination occurs at the collection site, in processing, or at the facility performing the test.