Surgical site infection rate is lower in laparoscopic than open colorectal surgery

OBJECTIVE

Few studies have investigated whether surgical site infection (SSI) incidence differs between laparoscopic colorectal surgery (LCS) and open colorectal surgery (OCS). This study investigated the SSI incidence using the validated UK SSI Surveillance Service (SSISS) criteria for diagnosing wound infections.

METHOD

Prospective data collection recorded patients' demographics, operative details, antibiotic use, wound evaluation and microbiological wound culture results, for consecutive patients undergoing elective resectional LCS and OCS. Postdischarge surveillance consisted of patient questionnaires sent out at 30 days and the primary care communication.

RESULTS

A total of 122 patients underwent colorectal resections over 1 year (LCS 43; OCS 79). Patients' demographics and operative case-mix were similar for both groups, including body mass index (BMI), diabetic and smoking status. Operative duration was longer in the LCS group compared with OCS group (P = 0.012, Mann-Whitney U-test), but hospital stay was shorter for LCS (P = 0.0001, Mann-Whitney U-test). The SSI rate was significantly lower in the LCS than OCS group (7%vs 25% respectively; P = 0.015, two-tailed Fisher's exact test). BMI > 30 and operation length > 4 h influenced the risk of SSI formation (P < 0.05, chi-squared test). One LCS patient required conversion to a limited laparotomy.

CONCLUSIONS

Surgical site infection incidence is significantly lower following LCS when compared with OCS. Confounding factors in this study include patient selection for LCS and nonrandomization.

Baseline Endogenous Estradiol and the Association of Hormone Therapy with Breast Cancer Risk, the Women's Health Initiative Clinical Trials

Background: The effect of exogenous hormones on breast cancer risk may depend on baseline endogenous levels of estradiol (E2). We investigated whether women with lower E2 levels will have the greatest increase in breast cancer risk during treatment with estrogen plus progestin ((E+P); combined conjugated equine estrogens (CEE) plus medroxyprogesterone acetate) or estrogen-alone ((E-alone); CEE) therapy. Additionally, we examined whether the risk of breast cancer varies by untreated levels of endogenous E2.Methods: We performed an ancillary study within the Women's Health Initiative E+P and E-alone clinical trials. We used a case-only design to test for interactions between untreated levels of E2 and hormone therapy (E+P or E-alone) on breast cancer risk. We measured baseline levels of bioavailable E2 in 346 cases of invasive breast cancer from the E+P trial and 231 cases from the E-alone trial. To estimate the risk of breast cancer by endogenous E2 levels (expressed as quartiles), we used a case-cohort design which included the cases described above in addition to a randomly selected comparison group (N=387; 203 from the E+P and 184 from the E-alone trial). Incident breast cancer cases were identified over an average follow-up of 4.1 years in the E+P trial and 5.4 years in the E-alone trial. All analyses were performed separately for the E+P and the E-alone trials.Results: In the case-only study, the effect of E+P therapy on breast cancer risk did not seem to vary by endogenous E2 quartiles (p-heterogeneity= 0.16). Breast cancer risk associated with E-alone treatment tended to be greater among women with the lowest E2 levels; however this association was not significant (hazard ratio (HR)= 1.44, 95% confidence interval (CI)= 0.79-2.59).Table 1. Effects of E+P and E-alone treatments on breast cancer risk (HR (95% CI)) by quartiles of baseline estradiol: case-only results E+PE-aloneEstradiol  Quartile 11.20 (0.80-1.80)1.44 (0.79-2.59)Quartile 20.88 (0.58-1.34)0.98 (0.58-1.67)Quartile 31.27 (0.81-2.00)0.79 (0.47-1.33)Quartile 40.67 (0.43-1.06)0.92 (0.57-1.49)P-heterogeneity0.160.51P-trend0.160.20 In the case-cohort analysis, higher endogenous E2 levels were associated with increased breast cancer risk (p-trend= 0.01), independent of hormone therapy.Table 2. Effects of baseline estradiol and hormone therapy (E+P vs. E-alone) on breast cancer risk (HR (95% CI)): case-cohort results E+PE-aloneHormone therapy treatment (Reference= placebo group)1.01 (0.96-1.07)0.84 (0.56-1.26)   Estradiol  Quartile 1 (Reference)1.001.00Quartile 21.22 (0.75-2.00)1.30 (0.77-2.17)Quartile 31.41 (0.87-2.32)1.32 (0.77-2.27)Quartile 41.85 (1.12-3.03)2.38 (1.32-4.35)P-trend0.010.01 Conclusion: The risk of breast cancer increases with higher levels of untreated endogenous E2. However, untreated E2 level does not modify the effect of E+P or E-alone therapy on breast cancer risk. Estradiol measurement is unlikely to identify women where hormone therapy may substantially increase the risk of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 906.

Sex Hormones and Risk of Estrogen Receptor (ER)-Positive and ER-Negative Breast Cancer

Background: There is a need for improved breast cancer risk prediction by tumor estrogen receptor (ER) status. Endogenous sex hormone levels are associated with risk of overall breast cancer and the ER-positive subtype. However, the role of estradiol (E2) and testosterone (T) in the development of ER-negative tumors remains unclear. We investigated the associations of circulating levels of endogenous E2 and T with the risk of ER-positive as well as ER-negative breast cancer in postmenopausal women.Methods: We performed a case-cohort study within the Women's Health Initiative- Observational Study of postmenopausal women not taking exogenous hormones (age range: 50-79 years). Baseline endogenous levels of bioavailable E2 and T were measured using radioimmunoassays (University of Southern California, LA, CA) in 196 cases of invasive ER-positive breast cancer, 107 cases of invasive ER-negative cancer, and 560 randomly selected controls. The average follow-up time was 7.3 years.Results: After adjustment for putative risk factors, women with E2 levels in the upper three quartiles had an approximately 2-fold increased risk of ER-positive breast cancer, compared to those with E2 in the lowest quartile. These associations were only modestly decreased after adjustment for T. Higher T levels also indicated increased risk of ER-positive breast cancer; women in the third quartile of T had a 1.7-fold significantly higher risk, compared to those in the first quartile. However, this association was substantially diminished and not significant after controlling for E2.No association was observed between E2 levels and ER-negative cancer. However, women with T levels in the second, third, and fourth quartiles had lower risks of ER-negative cancer in the order of 54% (p= 0.018), 38% (p= 0.13), and 46% (p= 0.05), respectively, compared to women with T in the lowest quartile. These associations did not change materially after adjusting for E2.Table 1. Risk (Hazard Ratio (HR) and 95% CI) of ER-positive and ER-negative breast cancer by E2 and T quartiles ER-positive (HR (95% CI))ER-negative (HR (95% CI)) Model 1*Model 2**Model 1*Model 2*E2    Q11.001.001.001.00Q22.19 (1.25-3.84)2.12 (1.16-3.87)0.57 (0.29-1.12)0.72 (0.34-1.53)Q31.92 (1.10-3.35)1.74 (0.92-3.33)0.75 (0.40-1.42)1.09 (0.51-2.3)Q42.11 (1.21-3.68)1.86 (0.97-3.56)0.88 (0.48-1.62)1.36 (0.60-3.08)P for trend0.020.150.840.44T    Q11.001.001.001.00Q21.01 (0.57-1.78)0.82 (0.44-1.53)0.46 (0.24-0.88)0.45 (0.22-0.92)Q31.72 (1.04-2.84)1.36 (0.75-2.48)0.62 (0.34-1.15)0.56 (0.27-1.18)Q41.45 (0.85-2.46)1.16 (0.62-2.17)0.54 (0.29-1.00)0.44 (0.20-1.00)P for trend0.050.280.100.09*Model1: adjusted for age, race, age at menopause, alcohol use, physical activity, history of needle aspiration, lifetime use of estrogen+progestin, and time since quitting hormone therapy use. **Model2: adjusted for Model1 + sex hormones.Conclusion: Higher endogenous E2 levels were associated with increased risk of ER-positive breast cancer, independent of risk factors and T. In contrast, higher concentrations of endogenous T were related to lower risk of ER-negative breast cancer, independent of risk factors and E2. This is the first study to report an association of testosterone with ER-negative breast cancer. Further studies are needed to confirm this association.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 907.

Co-existence of breast and ovarian cancers in BRCA germ-line mutation carriers

The co-existence of breast and ovarian cancers in the same individual should raise suspicion of a hereditary process. Patients with either BRCA1 or BRCA2 germ-line mutations have an average risk of 39% and 11% respectively of developing ovarian cancer by the age of 70; they have a risk of 35-85% of developing breast cancer in their lifetime. We report here unusual pathologic features in a BRCA2 germ-line mutation carrier recently diagnosed with synchronous breast and ovarian cancers, and summarize the findings in six other women who were diagnosed with ovarian cancer either simultaneously with the diagnosis of breast cancer or at varying times after the diagnosis. While in most instances this may be a coincidental occurrence in highly susceptible individuals, the patient we highlight raises the provocative hypothesis that at times breast cancer metastasizes to the ovaries of mutation carriers and stimulates the development of an ovarian cancer as well as other cancers. In addition, these ovarian cancers may have different mechanisms of metastases predisposing them to travel to unusual sites.

Parastomal hernia prevention using a novel collagen implant: a randomised controlled phase 1 study

BACKGROUND

Parastomal hernias can be prevented or repaired using synthetic mesh; however, reported complications include infection, fibrosis and potential bowel erosion. The study aim was to assess the safety, feasibility and potential efficacy of using a prophylactic collagen implant.

METHODS

Twenty patients undergoing defunctioning stomas were randomised to a conventional procedure or reinforcement with the implant. Follow-up included regular symptom questionnaires, clinical examination, stoma site ultrasound, and serum inflammatory markers.

RESULTS

Ten patients (four males; mean BMI 26.3) had a conventional stoma, and ten (three males; mean BMI 26.3) received the implant. At a median of 6.5 months follow-up, a parastomal hernia was clinically evident in three of ten patients without the implant, and in none of ten patients with the implant. There were no clinical complications, ultrasound evidence of chronic seromas or serological evidence of a systemic inflammatory response.

CONCLUSIONS

Xenogeneic collagen has been demonstrated to aid soft tissue reinforcement. In this study, in contrast to published data relating to the use of conventional synthetic mesh, there were no complications related to infection or the implant's proximity to the bowel. This trial demonstrates that the implant is safe, feasible to use and has the potential to prevent parastomal herniation.

Multiphase CT angiography versus single-phase CT angiography: comparison of image quality and radiation dose

BACKGROUND AND PURPOSE

Conventional CT angiography (CTA) is acquired during only a short interval in the arterial phase, which limits its ability to evaluate the cerebral circulation. Our aim was to compare the image quality and radiation dose of conventional single-phase CTA (SP-CTA) with a multiphase CTA (MP-CTA) algorithm reconstructed from a perfusion CT (PCT) dataset.

MATERIALS AND METHODS

Fifty consecutive patients undergoing head CTA and PCT in 1 examination were enrolled. The PCT dataset was obtained with 40.0-mm-detector coverage, 5.0-mm axial thickness, 80 kilovolt peak (kVp), 180 mA, and 30 mL of contrast medium. MP-CTA was reconstructed from the same PCT dataset with an axial thickness of 0.625 mm by using a new axial reconstruction algorithm. A conventional SP-CTA dataset was obtained with 0.625-mm axial thickness, 120 kVp, 350 mA, and 60 mL of contrast medium. We compared image quality, vascular enhancement, and radiation dose.

RESULTS

SP-CTA and MP-CTA of 50 patients (male/female ratio, 31/19; mean age, 59.25 years) were analyzed. MP-CTA was significantly better than SP-CTA in vascular enhancement (P = .002), in the absence of venous contamination (P = .006), and was significantly higher in image noise (P < .001). MP-CTA used less contrast medium than SP-CTA and could demonstrate hemodynamic information. The effective dose of MP-CTA was 5.73 mSv, which was equal to that in conventional PCT, and it was 3.57 mSv in SP-CTA.

CONCLUSION

It is feasible that MP-CTA may provide both CTA and PCT results. Compared with SP-CTA, MP-CTA provides comparable image quality, better vascular enhancement, hemodynamic information, and more noise with less detail visibility with a lower tube voltage. The radiation dose of MP-CTA is higher than that of SP-CTA, but the dose can be reduced by altering the sampling interval.

Change in surface hardness of enamel by a cola drink and a CPP-ACP paste

OBJECTIVES

This in vitro study used surface microhardness to evaluate whether a paste containing casein phosphopeptide amorphous calcium phosphate (CPP-ACP) can reharden tooth enamel softened by a cola drink, and how different saliva-substitute solutions affect the enamel hardness.

METHODS

Twenty-four bovine incisors, each tooth consisting of treatment and control halves, were immersed in a cola drink (Coke) for 8 min, then placed under a 0.4 mL/min drip with various saliva-substitute solutions. The saliva-substitute solutions were: saliva-like solution (SLS) with 1 ppm fluoride, SLS without fluoride, and Biotene mouthwash. CPP-ACP paste was applied to the treatment halves for 3 min at 0, 8, 24, and 36 h. Knoop microhardness measurements were performed at baseline, after the cola drink immersion, and after 24 and 48 h contact with saliva-substitute solution.

RESULTS

Enamel hardness significantly decreased after immersion in cola drink (ANOVA, p<0.05). After contact with saliva-like solutions for 48 h, those treated with CPP-ACP paste were significantly harder than those untreated regardless of the presence of 1 ppm fluoride in the saliva-like solution (ANOVA, p<0.05). Biotene mouthwash significantly softened the enamel surface (ANOVA, p<0.05). Two-way ANOVA showed significant effects of the CPP-ACP paste application and types of saliva-substitute solutions on the changes in surface hardness of the softened enamel at a significance level of 0.05.

CONCLUSION

The application of CPP-ACP paste with continuous replenishment of saliva-like solution for 48 h significantly hardened enamel softened by a cola drink. Biotene mouthwash softened enamel surface after 48 h contact.

Laparoscopic colorectal surgery - results from 200 patients

OBJECTIVE

Laparoscopic surgery is increasingly being performed for benign and malignant colorectal disease. This study examines the short-term results in a consecutive series of laparoscopic colorectal procedures performed over 2 years.

METHOD

A prospective database was established for all elective patients undergoing laparoscopic colorectal surgery by one surgeon. The main outcome measures assessed were operative duration, conversion rate, length of hospital stay, morbidity and mortality and lymph node harvest.

RESULTS

Two hundred and thirty-one consecutive patients were referred for elective colorectal surgery, with 18 patients excluded from laparoscopic surgery. Thirteen patients had nonresective laparoscopic colorectal procedures for endometriosis and have been excluded from the series. Of 200 patients who underwent a laparoscopic colorectal procedure, 114 (57%) were female, the median age was 67 years (inter-quartile range (IQR) 57-76), and there were 116 malignancies. The most common operations were anterior resection and sigmoid colectomy (n = 82), right hemicolectomy (n = 62) and left hemicolectomy (n = 12). The median operating time was 120 min (IQR 90-150) and 10 patients (5%) required conversion to open surgery. The median lymph node harvest in malignancies was 21 nodes (IQR 15-30) and no positive resection margins were found. There were two deaths and 29 significant complications (14.5%), with seven patients requiring re-operations because of postoperative complications. The median postoperative hospital stay was 4 days (IQR 3-6) and 13 patients (6.5%) were re-admitted within 30 days of hospital discharge.

CONCLUSION

Laparoscopic colorectal surgery is possible for most benign and malignant conditions, with low conversion and complication rates, as well as short hospital stay.

Increased Young's modulus and hardness of Col1a2oim dentin

Mice harboring the Col1a2(oim) mutation (oim) express dentinogenesis imperfecta. To determine the effect of Col1a2 genotype on tissue mechanical properties, we compared Young's modulus and hardness of dentin in the 3 Col1a2 genotypes. Upper incisors were tested by nanoindentation. Genotype had a significant effect on Young's modulus, but there was not a simple mutant allele dosage relationship. The effect of genotype on hardness did not reach significance. Hardness and Young's modulus were greater near the dento-enamel junction than near the pulp chamber. Greater hardness and Young's modulus values near the dento-enamel junction reflected continued mineralization of the dentin following its initial synthesis. Analysis showed the mechanical data to be consistent with Fourier transform infrared and backscattered electron microscopy studies that revealed increased mineralization in oim bone. Analysis of the data suggests that clinical fragility of teeth in oim mice is not due to deficiencies of hardness or Young's modulus, but may be due to defects in post-yield behavior or resistance to fatigue damage.

Gastrointestinal manifestations of chronic granulomatous disease

OBJECTIVE

Chronic granulomatous disease is a rare clinical entity characterized by recurrent infective and inflammatory complications. Patients are usually assigned to specialist centres, but nonspecialist clinicians may be required to treat these patients in the emergency setting. This review serves as a management guide to those clinicians who are faced with patients presenting with gastrointestinal manifestations of chronic granulomatous disease.

METHODS

This review is based on a literature search (Medline and NLM PubMed) with manual cross-referencing of all articles related to gastrointestinal chronic granulomatous disease.

RESULTS

Gastrointestinal tract involvement is present in most affected patients. Clinical presentation can mimic common surgical complications such as colitis, perianal sepsis, gastric outlet obstruction and liver abscess. A history of recurrent infections during childhood is common. Management involves haematological, microbiological, endoscopic and radiological investigations. Treatment modalities include early aggressive empirical antimicrobial therapy for sepsis, immunomodulation for inflammatory complications and surgical drainage of abscesses.

CONCLUSION

Early involvement of a centre with immunological expertise combined with aggressive management of complications significantly improves morbidity and mortality from this rare condition.

The recombinant HLA-B*5518 allele supports the evidence of conserved haplotype association of rare alleles

Allelic polymorphism of the major histocompatibility complex arises mostly from gene recombination. Intralocus gene recombination usually involves short fragments of DNA leading most commonly to single-nucleotide substitutions and rarely involves large fragments. Here, we report a new recombinant human leukocyte antigen (HLA)-B*5518 allele that has arisen via recombination of a large fragment of DNA spanning more than 70 nucleotides. During routine HLA typing of potential volunteer donors for the National Marrow Donor Program((R)), a new HLA-B allele was identified in two donors from Guam. The allele, B*5518, appears to be a product of recombination between B*5502 and B*40. Exons 1, 3, and 4 of the new allele belong to B*5502, whereas part of exon 2 belongs to one of B*40 alleles. Introns 1 and 2 appear to belong to B*55, suggesting that the recombination event may have occurred within the homologous parts of exon 2.

EXternal Pelvic REctal SuSpension (Express procedure) for rectal intussusception, with and without rectocele repair

Background

The results of conventional treatment for rectal intussusception and rectocele are unpredictable. The aim was to develop a less invasive surgical approach and to evaluate outcome in selected patients.

Methods

Seventeen patients (13 women; median age 47 (range 20–67) years) with rectal evacuatory dysfunction and rectal intussusception, 13 of whom had a rectocele, were selected. The intussusception was corrected by external pelvic suspension of the rectum, using collagen strips attached to the rectal wall and pubis. The rectocele was repaired with a collagen patch. Patients were assessed before and 6 months after surgery by symptom and quality of life questionnaires, anorectal physiological investigation and proctography, and were followed up for a median of 12 months.

Results

Sepsis requiring exploration occurred in two patients but there was no extrusion or need to remove the collagen. Of the 15 patients assessed after surgery, total symptom scores were significantly decreased (P &lt; 0·001) and quality of life scores improved (P &lt; 0·001). Proctographically, the degree of intussusception was improved in ten patients; six patients had normal postoperative proctograms. The rectocele was reduced in size in all patients, and was not demonstrable in eight.

Conclusion

An effective procedure for rectal intussusception and rectocele has been developed in a selected group of patients with marked evacuatory symptoms.

External pelvic rectal suspension (the Express procedure) for full-thickness rectal prolapse: evolution of a new technique

OBJECTIVE

The Délorme's operation for rectal prolapse is a safe procedure but has a high recurrence rate. We aimed to develop an operation akin to it, but designed to reduce this deficit.

PATIENTS AND METHODS

Thirty-one consecutive patients with rectal prolapse were included in the study. Initially, a conventional Délorme's procedure was performed and sutures or strips of Gore-Tex were attached circumferentially to the apex of the prolapse, tunneled subcutaneously, and anchored to the external surface of the pelvis. Subsequently, the procedure was modified. Acellular porcine collagen strips were used and buried within the apex without plication of the denuded rectal musculature. Patients were formally assessed preoperatively and four months postoperatively by symptom and quality of life questionnaires and subsequently by regular clinical review.

RESULTS

In the Gore-Tex group (N = 11; males:females = 10:1; mean age, 61 years) three patients underwent suture repair and eight had strip fixation. All suture repairs developed sepsis and one patient had a recurrence. Seven of the strip fixations (88 percent) developed sepsis that resulted in implant extrusion. There was one full-thickness and one mucosal recurrence after a median follow-up of 25 months. In the collagen group (N = 20; males:females = 2:18; mean age, 63 years), sepsis occurred in four patients, requiring surgical intervention in one patient (5 percent) (cf Gore-Tex group, P = 0.002). There was one mucosal and three full-thickness (15 percent) recurrences after a median follow-up of 14 months (cf Gore-Tex group, P = not significant). Significant improvements in symptom and quality of life scores were recorded in both groups at four months.

CONCLUSION

A new, minimally invasive perineal procedure for rectal prolapse has been developed and initial data testify to its relative safety provided collagen is used. It remains to be seen whether long-term recurrence rates will be lower than those of conventional perineal procedures.

Emerging new alleles suggest high diversity of HLA-C locus

Human leukocyte antigen (HLA)-C has only recently emerged as an important transplantation antigen and as a receptor for natural killer cells. Over the last few years, sequence-based typing (SBT) revealed the true diversity of HLA-C locus; however, the frequency at which new alleles are detected still remains high. During routine SBT of 3500 samples for the National Marrow Donor Program, we have identified 20 new HLA-C alleles reported in this article in 26 individuals. New variants have been characterized by direct sequencing of polymerase chain reaction product obtained by allele-specific amplification of potential new alleles. Most of the new alleles carry coding substitutions of residues located within the antigen-binding groove. The substitutions are predominantly located in the alpha2-helix which is consistent with the unique to HLA-C conservation of alpha1-helix. Seven new alleles, or 35%, have been identified in African Americans, two of them in three and four individuals each, suggesting that these alleles may not be rare. This observation reflects the fact that the minority groups, previously under-represented in the HLA research pools subjected to SBT, now begin to emerge as a main source of new HLA-C alleles. This study further confirms that HLA-C locus is at least as polymorphic as HLA-A and HLA-B.

Stress and dysmenorrhoea: a population based prospective study

BACKGROUND

Dysmenorrhoea is the most common gynaecological disorder in women of reproductive age. Despite the association between stress and pregnancy outcomes, few studies have examined the possible link between stress and dysmenorrhoea.

AIMS AND METHODS

Using a population based cohort of Chinese women, the independent effect of women's perceived stress in the preceding menstrual cycle on the incidence of dysmenorrhoea in the subsequent cycle was investigated prospectively. The analysis included 1160 prospectively observed menstrual cycles from 388 healthy, nulliparous, newly married women who intended to conceive. The perception of stress and the occurrence of dysmenorrhoea in each menstrual cycle were determined from daily diaries recorded by the women.

RESULTS

After adjustment for important covariates, the risk of dysmenorrhoea was more than twice as great among women with high stress compared to those with low stress in the preceding cycle (OR = 2.4; 95% CI 1.4 to 4.3). The risk of dysmenorrhoea was greatest among women with both high stress and a history of dysmenorrhoea compared to women with low stress and no history of dysmenorrhoea (OR = 10.4, 95% CI 4.9 to 22.3). Stress in the follicular phase of the preceding cycles had a stronger association with dysmenorrhoea than stress in the luteal phase of the preceding cycles.

CONCLUSION

This study shows a significant association between stress and the incidence of dysmenorrhoea, which is even stronger among women with a history of dysmenorrhoea.

HLA-Cw*1214 allele arisen via recombination between HLA-Cw*070201 and HLA-Cw*120201

Allelic polymorphism of the major histocompatibility complex arises mostly from gene conversion. Intralocus gene conversion usually involves limited fragments of DNA, whereas recombination involving large fragments of DNA is considered to be a rare event. During routine sequencing-based typing of donors for the National Marrow Donor Program, a new HLA-C allele was identified in a Caucasian donor. The allele, HLA-Cw*1214, proved to be the product of recombination between HLA-Cw*070201 and HLA-Cw*120201. Exons 1, 2, the 3' end of exon 3 and exon 4 (with one mismatch) belong to HLA-Cw*120201, whereas part of exon 3 belongs to HLA-Cw*070201. Sequencing with primers based in exon 2 and exon 3 showed that intron 2 of the new allele also belonged completely to HLA-Cw*1202. The recombination event apparently occurred within exon 3 with the first point of recombination somewhere between codons 92 and 134 and the second one between codons 157 and 181.

Use of whole genome amplification and comparative genomic hybridisation to detect chromosomal copy number alterations in cell line material and tumour tissue

We have established that whole genome amplification (WGA), in conjunction with genomic DNA array comparative genomic hybridisation (gaCGH) allows for the identification of genome-wide copy number abnormalities (CNAs) in DNA extracted from both cell line and patient material. To determine the fidelity and reproducibility of WGA to detect copy number imbalances using gaCGH, well characterized cell line genomic DNA was analysed. The gaCGH data obtained from non-amplified DNA and amplified DNA for the neuroblastoma cell line NUB7 and a paediatric medulloblastoma patient was almost identical. In addition, laser capture microdissection (LCM) of prostate tumour cells and subsequent WGA allowed for the detection of a number of CNAs that may not have been identified if DNA had been extracted in bulk from heterogeneous tissue. The results presented here demonstrate the use of WGA for generating sufficient DNA for gaCGH analysis without the introduction of significant sequence representation bias. The combination of amplification and gaCGH using DNA extracted from archival patient material has the potential for permitting the studying of DNA from small cancerous or pre-cancerous foci, which may help to identify potential genomic markers for early diagnosis.

Should we be worried? Investigation of signals generated by an electronic syndromic surveillance system--Westchester County, New York

INTRODUCTION

In January 2003, the Westchester County Department of Health (WCDH) began conducting electronic syndromic surveillance of hospital emergency department (ED) chief complaints. Although methods for data collection and analysis used in syndromic surveillance have been described previously, minimal information exists regarding the responses to and investigations of signals detected by such systems. This paper describes WCDH's experience in responding to syndromic surveillance signals during the first 9 months after the system was implemented.

OBJECTIVES

The objectives of this analysis were to examine WCDH's responses to signals detected by the county's syndromic surveillance system. Specific goals were to 1) review the actual complaints reported by hospital EDs to determine whether complaint data were accurately identified and classified into syndrome categories, and provide feedback from this review to data collection and analysis staff to refine text terms or filters used to identify and classify chief complaints; 2) develop procedures and response algorithms for investigating signals; 3) determine whether signals correlated with reportable communicable diseases or other incidents of public health significance requiring investigation and intervention; and 4) quantify the staffing resources and time required to investigate signals.

METHODS

During January 27-October 31, 2003, electronic files containing chief-complaint data from seven of the county's 13 EDs were collected daily. Complaints were classified into syndrome categories and analyzed for statistically significant increases. A line listing of each complaint comprising each signal detected was reviewed for exact complaint, number, location, patient demographics, and requirement for hospital admission.

RESULTS

A total of 59 signals were detected in eight syndrome categories: fever/influenza (11), respiratory (6), vomiting (11), gastrointestinal illness/diarrhea (8), sepsis (7), rash (7), hemorrhagic events (3), and neurologic (6). Line-listing review indicated that complaints routinely were incorrectly identified and included in syndrome categories and that as few as three complaints could produce a signal. On the basis of hospital, geographic, age, or sex clustering of complaints, whether the complaint indicated a reportable condition (e.g., meningitis) or potentially represented an unusual medical event, and whether rates of hospital admission were consistent with medical conditions, 34 of 59 signals were determined to require further investigation (i.e., obtaining additional information from ED staff or medical providers). Investigation did not identify any reportable communicable disease or other incidents of public health significance that would have been missed by existing traditional surveillance systems. Nine staff members spent 3 hours/week collectively investigating signals detected by syndromic surveillance.

CONCLUSIONS

Standardized sets of text terms used to identify and classify hospital ED chief complaints into syndrome categories might require modification on the basis of hospital idiosyncrasies in recording chief complaints. Signal investigations could be reasonably conducted by using local health department resources. Although no communicable disease events were identified, the system provided baseline and timely objective data for hospital visits and improved communication among county health department and hospital ED staff.