Microbiome-preserving antibiotics for the treatment of Clostridioides difficile infection: a systematic review and meta-analysis

BACKGROUND

Newer antibiotics that specifically target Clostridioides difficile while preserving the host microbiome have emerged to treat C. difficile infection (CDI): cadazolid, fidaxomicin, ridinilazole, and surotomycin. The aim of the present study was to perform a systematic review and meta-analysis of efficacy for each antibiotic.

METHODS

Only randomized clinical trials of patients being treated for Clostridioides disease infection were included. Studies were sought in MEDLINE, EMBASE, the Cochrane Register of Controlled Trials, ClinicalTrials.gov, and the World Health Organization clinical trials register portal (up to December 9, 2022). Sustained clinical cure was the outcome of treatment comparison, defined as the resolution of diarrhea without recurrence. Vancomycin was the standard treatment comparator. Meta-analysis was performed for each antibiotic. The overall certainty of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE)-classified as either high, moderate, low, or very low.

RESULTS

Fourteen eligible studies were included in the meta-analysis with 4837 patients from 773 sites. Cadazolid did not increase sustained clinical cure relative to vancomycin (risk ratio (RR) 1.04, 95% confidence intervals (CI) 0.96-1.13; moderate-certainty evidence). Fidaxomicin demonstrated a significant increase (RR 1.14, 95% CI 1.07-1.21; low-certainty evidence). In one phase 2 study, ridinilazole demonstrated a significant increase in sustained clinical cure (RR 1.71, 95% CI 1.01-2.91; very low-quality evidence). Surotomycin did not show significant improvement (RR 1.05, 95% CI 0.96-1.14; moderate-certainty evidence).

CONCLUSIONS

Fidaxomicin (in seven studies) demonstrated significant improvement in achieving sustained clinical cure. A limitation of this study may that more studies are needed to compare fidaxomicin with other antibiotics.

Antibiotic prophylaxis in colorectal surgery: are oral, intravenous or both best and is mechanical bowel preparation necessary?

BACKGROUND

The benefit of adding oral antibiotic prophylaxis (OA) to intravenous prophylaxis (IV) in elective colorectal surgery to prevent surgical site infection (SSI) and whether the benefit of OA requires a mechanical bowel cleansing (MBP) are assessed in a systematic review. Meta-analyses compare randomized trials of IV versus IV plus OA, both with MBP; OA versus IV plus OA, both again with MBP; OA plus IV in studies randomizing patients to MBP or no MBP; and IV versus IV plus OA in patients with no MBP.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched for eligible studies from 1965 to April 1, 2020. The outcome assessed was SSI, superficial and deep, but not organ space. For each included study, risk of bias was assessed using the Cochrane Risk of Bias tool version 1. For each comparison, meta-analysis was performed from data from eligible studies to obtain a summary effect and heterogeneity using RevMan. Sensitivity analyses were performed excluding studies of poor quality. Certainty of evidence was assessed using GRADE for each comparison.

RESULTS

Sixty-one studies published in 1971-2020 from 55 publications reporting 12,297 patients were eligible for inclusion. A total of 36 studies compared IV to OA plus IV with MBP. The risk ratio (RR) and 95% confidence interval (CI) for SSI with oral and IV vs. IV alone are 0.47, 0.40-0.56. The RR in 19 studies for IV plus OA versus OA alone is 0.48, 0.38-0.62. The RR for OA plus IV with MBP versus without MBP in 5 studies is 1.17, 0.84-1.64. The RR for OA plus IV versus IV alone when no bowel prep was used in two studies is 0.36, 0.18-0.72. RRs were similar in sensitivity analyses. The GRADE is high for the first two comparisons, moderate for the 3rd, and low for the 4th due to imprecision and heterogeneity.

CONCLUSIONS

Combined OA and IV is superior to either alone in preventing SSI. The certainty of evidence is such that further research is unlikely to alter this relationship when MBP is used. In randomized trials of MBP, OA plus IV shows no benefit from MBP versus no MBP. The last comparison shows in just two studies that as in the first meta-analysis, but in the absence of MBP, combined OA plus IV is also superior to IV alone.

Introgression of novel genetic diversity to improve soybean yield

KEY MESSAGE

Exotic soybean germplasm can be used to increase novel genetic diversity and yield potential of cultivars. Modern North American soybean (Glycine max [L.] Merr.) cultivars have been derived from only a few ancestors. The objectives of this research were to develop breeding lines with novel genetic diversity that were equivalent to the yield of a commercial cultivar parent and within those lines identify regions of novel genetic diversity that were not present in the Corteva Agriscience elite soybean germplasm pool. Nine lines created from diverse germplasm (USDA-ARS breeding program at the University of Illinois) were crossed to a RM34Elite parent to develop populations and sublines for yield testing. Across yield tests at 30 locations conducted between 2014 and 2016, eleven breeding lines were identified that were equivalent to or significantly higher in yield when compared to the RM34Elite parent. Among the eleven final lines, the introgressed novel haplotypes that were not present in current Corteva Agriscience soybean germplasm occupied an estimated 0.8-10.0% of the genome. JH-2665, the highest yielding line across 3 years of testing, yielded 280 kg/ha more than the RM34Elite parent and had an estimated 8.6% of the genome containing novel diversity haplotypes. JH-2665 had 96 regions of novel diversity introgression ranging from 1 to 12 cM in size, with six regions over 6 cM in length. The methods reported demonstrate how high-yielding lines with novel genetic diversity can be developed. This material will be useful for expanding the genetic diversity needed to improve genetic gain in future soybean cultivar development.

Cesarean delivery to prevent anal incontinence: a systematic review and meta-analysis

BACKGROUND

Cesarean delivery (CD), is increasingly recommended as a mode of delivery that prevents the anal incontinence (AI) that arises in some women after vaginal delivery (VD). The assessment of the efficacy of CD in this regard was the subject of this systematic review.

METHODS

Searches were conducted in Medline, EMBASE and the Cochrane Library. Both randomized (RCTs) and non-randomized trials (NRTs) comparing the risk of sustained fecal and/or flatus incontinence after VD or CD were sought from 1966 to 1 January, 2019. Studies were eligible if they assessed AI more than 6 months after birth, and had statistical adjustment for at least one of the three major confounders for AI: age, maternal weight or parity. In addition, each study was required to contain more than 250 participants, more than 50 CDs and more than 25 cases of AI. Data after screening and selection were abstracted and entered into Revman for meta-analysis. Analyses were done for combined fecal and flatus incontinence (comAI), fecal incontinence (FI), gas incontinence (GI), CD before or during labor, time trend of incontinence after delivery, assessment of both statistical and clinical heterogeneity, parity and late incident AI.

RESULTS

Out of the 2526 titles and abstracts found, 24 eligible studies were analyzed, 23 NRTs and one RCT. These included women with 29,597 VDs and women with 6821 CDs. Among the primary outcomes, VD was found not to be a significant predictor of postpartum comAI compared to CD in 6 studies, incorporating 18,951 deliveries (OR = 0.74; 0.54-1.02). VD was also not a significant predictor of FI in 14 studies, incorporating 29,367 deliveries, (OR = 0.89; 0.76-1.05). VD was not a significant predictor of GI in six studies, incorporating 6724 deliveries (OR = 0.96; 0.79-1.18). The strength of the grading of recommendations, assessment, development and evaluations (GRADE) evidence for each of these was low for comAI and moderate for FI and GI (upgrade for lack of expected effect). Time trend FI showed incontinence at 3 months often resolved at 1 year. Other secondary analyses assessing parity, delayed incidence of FI, clinical and statistical heterogeneity, spontaneous VD only, late risk of incidence of AI, and CD in or prior to labor all had similar results as in the primary outcomes.

CONCLUSIONS

There are three components of pelvic floor dysfunction that are thought to be caused by VD and hopefully prevented by CD: AI, urinary incontinence and pelvic floor prolapse. Of these, AI was not found to be reliably prevented by CD in this review.

Correction to: Topical antimicrobial prophylaxis in colorectal surgery for the prevention of surgical wound infection: a systematic review and meta-analysis

Unfortunately, an author name (Nuzhat Iqbal) was missed out in the original publication. The complete updated author list is given below.

Topical antimicrobial prophylaxis in colorectal surgery for the prevention of surgical wound infection: a systematic review and meta-analysis

BACKGROUND

Among the techniques investigated to reduce the risk of surgical wound infection or surgical space infection (SSI) in patients having colorectal surgery are topical application of antimicrobials (antibiotics and antiseptics) to the open wound or immediately after closure. The aim of the present study was to perform a systematic review of the literature on those treatments, with the exception of antibiotic ointments applied to closed skin, which are adequately assessed elsewhere, and a meta-analysis.

METHODS

Only randomized trials of patients having only colorectal surgery were included in this review. Studies were sought in MEDLINE, EMBASE, the Cochrane Register of Controlled Trials, Clinical Trials.gov, and the World Health Organization Internet clinical trials register portal. In addition, reference lists of included studies and other published reviews were screened. Meta-analysis was performed for all included studies and subgroup analyses done for each individual intervention. Risk of bias was assessed for each included study, paying particular attention to the preoperative antibiotic prophylaxis used in each study. Sensitivity analyses were done to investigate heterogeneity of the analyses, excluding those studies with a significant risk of bias issues. Absolute risk reduction (RR) was calculated. The overall quality of the evidence for each individual intervention was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, and was classified as high, moderate, low or very low.

RESULTS

A total of 30 studies are included in this review with 5511 patients, 665 of whom had SSI. The interventions included: 10 studies of gentamicin impregnated sponge or beads wound inlays, 4 studies of chlorhexidine impregnated suture, 11 studies of direct wound lavage or powder application or injection of antibiotics before closure, 4 studies of ionized silver dressing applied to the closed skin, and 1 study of vitamin E oil applied to the open wound. All but one study used preoperative antibiotic prophylaxis in addition to topical procedures, although, in some studies, the systemic antibiotic prophylaxis was not the same between groups or varied significantly from the recommended guidelines. Use of gentamycin sponge did not decrease SSI (RR 0.93, 95% CI 0.75-1.16; low-quality evidence) even after including only the studies of abdominal wounds (RR 1.02, 95% CI 0.80-1.30; low-quality evidence). However, sensitivity analysis excluding studies at high risk of bias decreased the heterogeneity and increased the effect of the prophylaxis for all wounds (RR 0.5, 95% CI 0.33-0.78; low-quality evidence) and for abdominal wounds only (RR 0.38, 95% CI 0.20-0.72; moderate-quality evidence). Chlorhexidine impregnated suture showed no effect on SSI (RR 0.79, 95% CI 0.56-1.10; low-quality evidence) and an increased efficacy after sensitivity analysis (RR 0.42, 95% CI 0.22-0.79; low-quality evidence). Antibiotic lavage showed a significant decrease in SSI (RR 0.45, 95% CI 0.26-0.79; low-quality evidence) which increased after sensitivity analysis (RR 0.33, 95% CI 0.15-0.72; moderate-quality evidence). Application of silver dressing to the closed wound resulted in a decrease of SSI (RR 0.55, 95% CI 0.35-0.85; moderate-quality evidence). The one study of topical vitamin E oil applied to the open wound showed a significant risk reduction (RR 0.22, 95% CI 0.05-0.98; low-quality evidence).

CONCLUSIONS

Each of these interventions appears to be effective in decreasing SSI, but the number of studies for each is small and the quality of evidence is very low to moderate. Within the various outcomes of GRADE assessment, even a moderate classification suggests that further studies may well have very different results.. No randomized trials exist of combinations of two or more of the above interventions to see if there is a combined effect. Future studies should make sure that the antibiotic used preoperatively is uniform within a study and is consistent with the current guidelines. Deviation from this leads to a significant heterogeneity and risk of bias.

Dendritic Cell Trafficking and Function in Rare Lung Diseases

Dendritic cells (DCs) are highly specialized immune cells that capture antigens and then migrate to lymphoid tissue and present antigen to T cells. This critical function of DCs is well defined, and recent studies further demonstrate that DCs are also key regulators of several innate immune responses. Studies focused on the roles of DCs in the pathogenesis of common lung diseases, such as asthma, infection, and cancer, have traditionally driven our mechanistic understanding of pulmonary DC biology. The emerging development of novel DC reagents, techniques, and genetically modified animal models has provided abundant data revealing distinct populations of DCs in the lung, and allow us to examine mechanisms of DC development, migration, and function in pulmonary disease with unprecedented detail. This enhanced understanding of DCs permits the examination of the potential role of DCs in diseases with known or suspected immunological underpinnings. Recent advances in the study of rare lung diseases, including pulmonary Langerhans cell histiocytosis, sarcoidosis, hypersensitivity pneumonitis, and pulmonary fibrosis, reveal expanding potential pathogenic roles for DCs. Here, we provide a review of DC development, trafficking, and effector functions in the lung, and discuss how alterations in these DC pathways contribute to the pathogenesis of rare lung diseases.

A systematic review and meta-analysis of the treatment of anal fissure

BACKGROUND

Anal fissure has a very large number of treatment options. The choice is difficult. In an effort to assist in that, choice presented here is a systematic review and meta-analysis of all published treatments for anal fissure that have been studied in randomized controlled trials.

METHODS

Randomized trials were sought in the Cochrane Controlled Trials Register, Medline, EMBASE and the trials registry sites clinicaltrials.gov and who/int/ictrp/search/en. Abstracts were screened, full-text studies chosen, and finally eligible studies selected and abstracted. The review was then divided into those studies that compared two or more surgical procedures and those that had at least one arm that was non-surgical. Studies were further categorized by the specific interventions and comparisons. The outcome assessed was treatment failure. Negative effects of treatment assessed were headache and anal incontinence. Risk of bias was assessed for each study, and the strength of the evidence of each comparison was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

RESULTS

One hundred and forty-eight eligible trials were found and assessed, 31 in the surgical group and 117 in the non-surgical group. There were 14 different operations described in the surgical group and 29 different non-surgical treatments in the non-surgical group along with partial lateral internal sphincterotomy (LIS). There were 61 different comparisons. Of these, 47 were reported in 2 or fewer studies, usually with quite small patient samples. The largest single comparison was glyceryl trinitrate (GTN) versus control with 19 studies. GTN was more effective than control in sustained cure (OR 0.68; 95% CI 0.63-0.77), but the quality of evidence was very poor because of severe heterogeneity, and risk of bias due to inadequate clinical follow-up. The only comparison to have a GRADE quality of evidence of high was a subgroup analysis of LIS versus any medical therapy (OR 0.12; CI 0.07-0.21). Most of the other studies were downgraded in GRADE due to imprecision.

CONCLUSIONS

LIS is superior to non-surgical therapies in achieving sustained cure of fissure. Calcium channel blockers were more effective than GTN and with less risk of headache, but with only a low quality of evidence. Anal incontinence, once thought to be a frequent risk with LIS, was found in various subgroups in this review to have a risk between 3.4 and 4.4%. Among the surgical studies, manual anal stretch performed worse than LIS in the treatment of chronic anal fissure in adults. For those patients requiring surgery for anal fissure, open LIS and closed LIS appear to be equally efficacious, with a moderate GRADE quality of evidence. All other GRADE evaluations of procedures were low to very low due mostly to imprecision.

NK cell activating receptor ligand expression in lymphangioleiomyomatosis is associated with lung function decline

Lymphangioleiomyomatosis (LAM) is a rare lung disease of women that leads to progressive cyst formation and accelerated loss of pulmonary function. Neoplastic smooth muscle cells from an unknown source metastasize to the lung and drive destructive remodeling. Given the role of NK cells in immune surveillance, we postulated that NK cell activating receptors and their cognate ligands are involved in LAM pathogenesis. We found that ligands for the NKG2D activating receptor UL-16 binding protein 2 (ULBP2) and ULBP3 are localized in cystic LAM lesions and pulmonary nodules. We found elevated soluble serum ULBP2 (mean = 575 pg/ml ± 142) in 50 of 100 subjects and ULBP3 in 30 of 100 (mean = 8,300 pg/ml ± 1,515) subjects. LAM patients had fewer circulating NKG2D⁺ NK cells and decreased NKG2D surface expression. Lung function decline was associated with soluble NKG2D ligand (sNKG2DL) detection. The greatest rate of decline forced expiratory volume in 1 second (FEV₁, -124 ± 30 ml/year) in the 48 months after enrollment (NHLBI LAM Registry) occurred in patients expressing both ULBP2 and ULBP3, whereas patients with undetectable sNKG2DL levels had the lowest rate of FEV₁ decline (-32.7 ± 10 ml/year). These data suggest a role for NK cells, sNKG2DL, and the innate immune system in LAM pathogenesis.

Genetic architecture of cyst nematode resistance revealed by genome-wide association study in soybean

BACKGROUND

Bi-parental mapping populations have been commonly utilized to identify and characterize quantitative trait loci (QTL) controlling resistance to soybean cyst nematode (SCN, Heterodera glycines Ichinohe). Although this approach successfully mapped a large number of SCN resistance QTL, it captures only limited allelic diversity that exists in parental lines, and it also has limitations for genomic resolution. In this study, a genome-wide association study (GWAS) was performed using a diverse set of 553 soybean plant introductions (PIs) belonging to maturity groups from III to V to detect QTL/genes associated with SCN resistance to HG Type 0.

RESULTS

Over 45,000 single nucleotide polymorphism (SNP) markers generated by the SoySNP50K iSelect BeadChip (http// www.soybase.org ) were utilized for analysis. GWAS identified 14 loci distributed over different chromosomes comprising 60 SNPs significantly associated with SCN resistance. Results also confirmed six QTL that were previously mapped using bi-parental populations, including the rhg1 and Rhg4 loci. GWAS identified eight novel QTL, including QTL on chromosome 10, which we have previously mapped by using a bi-parental population. In addition to the known loci for four simple traits, such as seed coat color, flower color, pubescence color, and stem growth habit, two traits, like lodging and pod shattering, having moderately complex inheritance have been confirmed with great precision by GWAS.

CONCLUSIONS

The study showed that GWAS can be employed as an effective strategy for identifying complex traits in soybean and for narrowing GWAS-defined genomic regions, which facilitates positional cloning of the causal gene(s).

Intersubgeneric hybridization between Glycine max and G. tomentella: production of F₁, amphidiploid, BC₁, BC₂, BC₃, and fertile soybean plants

KEY MESSAGE

This paper describes methods for unlocking genetic treasure from wild perennial Glycine species of Australia for soybean improvement. The genetic resources of the ca. 26 species of the genus Glycine subgenus Glycine have not been exploited to broaden the genetic base of soybean (Glycine max; 2n = 40). The objectives of this study were to develop methods for producing F1, amphidiploid, BC1, BC2, BC3, and fertile soybean plants from crosses of soybean and the genus Glycine subgenus Glycine species, in order to utilize the subgenus Glycine germplasm in soybean breeding. Soybean cultivars were hybridized with six accessions of 78-chromosome G. tomentella as well as one accession each of 40-chromosome G. tomentella, G. argyrea and G. latifolia. They were chosen because they exhibit resistance to soybean rust. We were successful in producing fertile soybean from soybean cv. 'Dwight' and 78-chromosome G. tomentella accession PI 441001, while other hybrids were discontinued either at F1 or amphidiploid stage. The F1 seeds aborted prior to reaching maturity, so developing seeds from 19 to 21 day old pods were cultured aseptically in various media formulations. Seed maturation and multiple embryo generation media were developed. F1 plants with shoots and roots (2n = 59) were transplanted to pots in greenhouse. Amphidiploid (2n = 118) plants were backcrossed to 'Dwight'. BC1 (2n = 79) plants were propagated through in vitro and 43 mature BC2F1 seeds were harvested. Fifteen surviving BC2F1 plants were morphologically distinct, sterile, and had chromosome numbers ranging 2n = 56-59. Chromosome numbers of the BC3F1 plants ranged 2n = 40-49. Derived fertile soybeans were first planted in the field in 2008 and are being evaluated for yield, resistance to pathogens and pests and tolerance to salt through material transfer agreement.

Identification of positive yield QTL alleles from exotic soybean germplasm in two backcross populations

Increasing seed yield is an important breeding goal of soybean [Glycine max (L.) Merr.] improvement efforts. Due to the small number of ancestors and subsequent breeding and selection, the genetic base of current soybean cultivars in North America is narrow. The objective of this study was to map quantitative trait loci (QTL) in two backcross populations developed using soybean plant introductions as donor parents. The first population included 116 BC(2)F(3)-derived lines developed using "Elgin" as the recurrent parent and PI 436684 as the donor parent (E population). The second population included 93 BC(3)F(3)-derived lines developed with "Williams 82" as the recurrent parent and PI 90566-1 as the donor parent (W population). The two populations were evaluated with 1,536 SNP markers and during 2 years for seed yield and other agronomic traits. Genotypic and phenotypic data were analyzed using the programs MapQTL and QTLNetwork to identify major QTL and epistatic QTL. In the E population, two yield QTL were identified by both MapQTL and QTLNetwork, and the PI 436684 alleles were associated with yield increases. In the W population, a QTL allele from PI 90566-1 accounted for 30 % of the yield variation; however, the PI region was also associated with later maturity and shorter plant height. No epistasis for seed yield was identified in either population. No yield QTL was previously reported at the regions where these QTL map indicating that exotic germplasm can be a source of new alleles that can improve soybean yield.

Surgical management of anal fistulae: a systematic review

OBJECTIVE

The anal fistula has been a common surgical ailment reported since the time of Hippocrates but little systematic evidence exists on its management. We aimed to systematically review the available studies relating to the surgical management of anal fistulas.

METHOD

Studies were identified from PubMED, EMBASE, Cochrane Controlled Trials Register, ClinicalTrials.Gov and Current Controlled Trials. All uncontrolled, nonrandomized, retrospective studies, duplications or those unrelated to the surgical management of anal fistulas were excluded.

RESULTS

The search strategy revealed 443 trials. After exclusions 21 randomized controlled trials remained evaluating: fistulotomy vs fistulectomy (n = 2), seton treatment (n = 3), marsupialization (n = 2), glue therapy (n = 3), anal flaps (n = 3), radiosurgical approaches (n = 2), fistulotomy/fistulectomy at time of abscess incision (n = 5) and intra-operative anal retractors (n = 1). Two meta-analyses evaluating incision and drainage alone vs incision + fistulotomy were obtained.

CONCLUSION

Marsupialization after fistulotomy reduces bleeding and allows for faster healing. Results from small trials suggest flap repair may be no worse than fistulotomy in terms of healing rates but this requires confirmation. Flap repair combined with fibrin glue treatment of fistulae may increase failure rates. Radiofrequency fistulotomy produces less pain on the first postoperative day and may allow for speedier healing. Major gaps remain in our understanding of anal fistula surgery.

Landmark research in legumes

Legumes are members of the family Fabaceae or Leguminosae and include economically important grain legumes, oilseed crops, forage crops, shrubs, and tropical or subtropical trees. Legumes are a rich source of quality protein for humans and animals. They also enrich the soil by producing their own nitrogen in symbiosis with nitrogen-fixing bacteria. International centers and national institutes collect, maintain, distribute, and produce high-yielding legumes (grain-pulses, oilseeds, forages, nutraceuticals, medicinal shrubs, and trees). Legume breeders are confined within the primary gene pools (GP-1) in their varietal improvement programs and have not exploited secondary gene pools (GP-2), tertiary gene pools (GP-3), or quaternary gene pools (GP-4). Legumes are also an excellent source of timber, medicine, nutraceuticals, tannins, gums, insecticides, resins, varnish, paints, dyes, and eco-friendly by-products such as soy diesel. Three forage crops, Medicago truncatula , Lotus japonicus , and Trifolium pratense , are model legumes for phylogenetic studies and genome sequencing. This paper concludes that a “protein revolution” is needed to meet the protein demands of the world.

Surgery for faecal incontinence in adults

BACKGROUND

Faecal incontinence is a debilitating problem with significant medical, social and economic implications. Treatment options include conservative, non-surgical interventions (e.g. pelvic floor muscle training, biofeedback, drugs, sacral nerve stimulation) and surgical procedures. A surgical procedure may be aimed at correcting an obvious mechanical defect, or augmenting a functionally deficient but structurally intact sphincter complex or replace an absent/non-functioning sphincter.

OBJECTIVES

To assess the effects of surgical techniques for the treatment of faecal incontinence in adults who do not have rectal prolapse. Our aim was firstly to compare surgical management with non-surgical management and secondly, to compare the various surgical techniques.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group Specialised Trials Register (31 January 2006), the Cochrane Colorectal Cancer Group trials register (31 January 2006), the Cochrane Central Register of Controlled Trials (2006, Issue 1), PubMed (1 January 1950 to 31 January 2006) and EMBASE (1 January 1998 to 31 January 2006) were undertaken. The British Journal of Surgery (January 1995 to May 2006) Colorectal Diseases (January 2000-May 2006) and the Diseases of the Colon and Rectum (January 1995 to May 2006) were specifically handsearched. The proceedings of the Association of Coloproctology meeting held from 1999 to 2006 were perused. Reference lists of all relevant articles were searched for further trials.

SELECTION CRITERIA

All randomised or quasi-randomised trials of surgery in the management of adult faecal incontinence (other than surgery for rectal prolapse).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies from the literature searches, assessed the methodological quality of eligible trials and extracted data. The three primary outcome measures were: change or deterioration in incontinence, failure to achieve full continence, and the presence of faecal urgency.

MAIN RESULTS

Nine trials were included with a total sample size of 264 participants. Two trials included a group managed non-surgically. One trial compared levatorplasty with anal plug stimulation, one compared artificial bowel sphincter with best supportive care; numbers were small in both trials. The artificial bowel sphincter insertion was followed by significant improvements in at least one primary outcome but with high rates of significant morbidity. Seven studies compared different surgical interventions. These included anterior levatorplasty versus postanal repair, anterior levatorplasty versus total pelvic floor repair, total pelvic floor versus postanal repair, end to end versus overlap sphincter repair, overlap repair with or without a defunctioning stoma or with or without biofeedback, total pelvic floor repair versus repair plus internal sphincter plication and neosphincter formation versus total pelvic floor repair. Only one comparison had more that one trial (total pelvic floor versus postanal repair-44 participants) and no comparison showed any statistically significant difference in primary outcome measures, with wide confidence intervals.

AUTHORS' CONCLUSIONS

Despite more studies being included in this update, the continued small number of relevant trials identified together with their small sample sizes and other methodological weaknesses continue to limit the usefulness of this review for guiding practice. It was impossible to identify or refute clinically important differences between the alternative surgical procedures. Larger rigorous trials are still needed. However, it should be recognised that the optimal treatment regime may be a complex combination of various surgical and non-surgical therapies.

Free-air carbon dioxide enrichment of soybean: influence of crop variety on residue decomposition

Elevated atmospheric CO2 can result in larger plants returning greater amounts of residue to the soil. However, the effects of elevated CO2 on carbon (C) and nitrogen (N) cycling for different soybean varieties have not been examined. Aboveground residue of eight soybean [Glycine max (L.) Merr.] varieties was collected from a field study where crops had been grown under two different atmospheric CO2 levels [370 micromol mol(-1) (ambient) and 550 micromol mol(-1) (free-air carbon dioxide enrichment, FACE)]. Senesced residue material was used in a 60-d laboratory incubation study to evaluate potential C and N mineralization. In addition to assessing the overall effects of CO2 level and variety, a few specific variety comparisons were also made. Across varieties, overall residue N concentration was increased by FACE, but residue C concentration was only slightly increased. Overall residue C to N ratio was lower under FACE and total mineralized N was increased by FACE, suggesting that increased N2 fixation impacted residue decomposition; total mineralized C was also slightly increased by FACE. Across CO2 levels, varietal differences were also observed with the oldest variety having the lowest residue N concentration and highest residue C to N ratio; mineralized N was lowest in the oldest variety, illustrating the influence of high residue C to N ratio. It appears (based on our few specific varietal comparisons) that the breeding selection process may have resulted in some varietal differences in residue quality which can result in increased N or C mineralization under elevated CO2 conditions. This limited number of varietal comparisons indicated that more work investigating varietal influences on soil C and N cycling under elevated CO2 conditions is required.

Response of Commercially Developed Soybean Cultivars and the Ancestral Soybean Lines to Fusarium solani f. sp. glycines

Sudden death syndrome, caused by Fusarium solani f. sp. glycines, has caused severe damage to soybean production in recent years. One way to control sudden death syndrome is with resistant cultivars. Over a 3-year period, 2,335 publicly and privately developed soybean entries were inoculated and evaluated for their response to F. solani f. sp. glycines under greenhouse conditions. The entries were compared with the susceptible check, Great Lakes 3302 (GL3302), and the moderately resistant checks, plant introductions (PIs) 520733 and 567374. Thirty-eight entries were identified with moderate levels of resistance. Based on foliar ratings, there were no differences (P < 0.05) between the Roundup Ready and conventional cultivars. In all, 90 ancestral lines that represent 99% of the genes in modern U.S. cultivars and 55 lines found in the pedigrees of public cultivars reported to have some resistance were evaluated for their response to F. solani f. sp. glycines. Nine ancestral lines (Aoda, Kim, Jackson, Sioux, Mammoth Yellow, T117, PI 171450, PI 54615-1, and PI 71506) and 12 cultivars or experimental lines (Ina, D83-3349, LN98-4340, LN83-2356, Hartwig, Harosoy, Bedford, Merit, Cutler, Calland, Hill, and Evans) had disease ratings not significantly different (P < 0.05) from PI 520733 or PI 567374. PI 54610, a putative ancestral line, also was found to be moderately resistant.

Selected Soybean Plant Introductions with Partial Resistance to Sclerotinia sclerotiorum

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a major soybean (Glycine max) disease in north-central regions of the United States and throughout the world. Current sources of resistance to Sclerotinia stem rot express partial resistance, and are limited in number within soybean germ plasm. A total of 6,520 maturity group (MG) 0 to IV plant introductions (PIs) were evaluated for Sclerotinia stem rot resistance in the United States and Canada in small plots or in the greenhouse from 1995 to 1997. Selected PIs with the most resistance were evaluated for resistance in the United States and Canada in replicated large plots from 1998 to 2000. The PIs in the MG I to III tests in Urbana, IL were evaluated for agronomic traits from 1998 to 2000. The selected PIs also were evaluated with an excised leaf inoculation and petiole inoculation technique. After the 1995 to 1997 evaluations, all but 68 PIs were eliminated because of their susceptibility to Sclerotinia stem rot. In field tests in Urbana, higher disease severity in selected MG I to III PIs was significantly (P< 0.05) associated with taller plant heights and greater canopy closure. All other agronomic traits evaluated were not associated or were inconsistently associated with disease severity. MG I to III PIs 153.282, 189.931, 196.157, 398.637, 417.201, 423.818, and 561.331 had high levels of resistance and had canopies similar to the resistant checks. The resistance ratings from the petiole inoculation technique had a high and significant (P< 0.01) correlation with disease severity in the MG I and II field tests. The partially resistant PIs identified in this study can be valuable in incorporating Sclerotinia stem rot resistance into elite germ plasm.

Evaluation of Glycine max Germ Plasm for Resistance to Fusarium solani f. sp. glycines

Sudden death syndrome, caused by Fusarium solani f. sp. glycines, has caused increased losses in soybean production in recent years. This study was done to identify potential sources of resistance to sudden death syndrome. Using a greenhouse screening procedure, 6,037 soybean plant introductions (PIs) were compared with a susceptible check, Great Lakes 3302, and two moderately resistant checks, PI 520.733 and PI 567.374, for resistance to sudden death syndrome. Only 57 PIs had foliar disease ratings that were not significantly different from PI 567.374 (P ≤ 0.05) 3 weeks after inoculation. Six PIs had lower ratings than PI 567.374 at 4 weeks after inoculation, while none had lower area under the disease progress curve (AUDPC) values. When comparing the PIs to PI 520.733, 209 PIs had foliar disease ratings not significantly different from PI 520.733 (P ≤ 0.05) 3 weeks after inoculation. Eight PIs had significantly lower disease severity ratings 4 weeks after inoculation, and 38 PIs had significantly lower AUDPC values than PI 520.733. Additionally, root lesion lengths were measured 4 weeks after inoculation and ranged from 25.2 to 41.5 mm for all the PIs; none of the entries had smaller lesion lengths than the susceptible check Great Lakes 3302. The correlation between lesion length and disease foliar severity rating was not significant. There also were no plant morphological characteristics (i.e., flower color or seed coat color) associated with higher sudden death syndrome foliar symptoms. Eighteen PIs previously identified as moderately resistant with differing agronomic traits were inoculated with five different isolates of Fusarium solani f. sp. glycines. Results indicated that resistance in these 18 PIs was effective against all five isolates of Fusarium solani f. sp. glycines. Isolate Mont-1 caused the greatest disease severity ratings. These PIs that exhibited low foliar severity ratings may provide new sources of resistance for the development of new sudden death syndrome-resistant lines and cultivars.

Risk of disease in siblings of patients with hereditary hemochromatosis

BACKGROUND

Parents of hereditary hemochromatosis (HH) homozygote patients, who are predominantly HH heterozygotes, have been found to have an increased risk of colonic neoplasia, diabetes, stroke death, stomach cancer and leukemia. The health histories of siblings of HH patients are reported.

METHODS

Individuals homozygous for HH were mailed questionnaires concerning the health histories of their siblings. Spouses of the HH homozygotes were asked to complete accompanying questionnaires concerning their siblings. The frequencies of serious illness and, when specified, each reported disease were determined by zygosity, odds ratios and 95% confidence intervals estimated.

RESULTS

Data were available for 279 siblings known to be HH homozygotes (HHs), and 1,265 other siblings of HH patients, who are predominantly hemochromatosis heterozygotes (HHhet). Controls consisted of 1,338 spouse siblings in whom only the general population prevalence of HH homozygosity and heterozygosity existed. Odds ratios comparing HH strata to controls were elevated for serious illness (1.12 in HHhet, 1.71 in HHs), diabetes (0.78, 2.45), arthritis (2.10, 1.69), and hepatoma (1.06, 11.96).

CONCLUSIONS

There was a significant trend for increased risk of serious illness among siblings of HH patients with increasing exposure to the HH gene, especially for diabetes, arthritis and hepatoma.

Response of Ancestral Soybean Lines and Commercial Cultivars to Rhizoctonia Root and Hypocotyl Rot

Rhizoctonia root and hypocotyl rot is a common disease of soybean caused by Rhizoctonia solani. There are no commercial cultivars marketed as resistant to Rhizoctonia root and hypocotyl rot, and only a few sources of partial resistance to this disease have been reported. Ninety ancestral soybean lines, maturity groups (MGs) 000 to X, and 700 commercial cultivars, MGs II to IV, were evaluated for resistance to R. solani under greenhouse conditions. Most of the ancestral lines and cultivars evaluated were susceptible; however, 21 of the ancestral lines and 20 of the commercial cultivars were partially resistant. Of the 21 ancestral lines, CNS, Mandarin (Ottawa), and Jackson are in the pedigree of cultivars previously reported as being partially resistant to R. solani. In an additional study, dry root weights of 21 soybean cultivars were evaluated after inoculation with R. solani. Variation in dry root weight occurred among cultivars, but there was not a significant (P = 0.05) correlation between dry root weight and disease severity.

The landing of the NEAR-Shoemaker spacecraft on asteroid 433 Eros

The NEAR-Shoemaker spacecraft was designed to provide a comprehensive characterization of the S-type asteroid 433 Eros (refs 1,2,3), an irregularly shaped body with approximate dimensions of 34 x 13 x 13 km. Following the completion of its year-long investigation, the mission was terminated with a controlled descent to its surface, in order to provide extremely high resolution images. Here we report the results of the descent on 12 February 2001, during which 70 images were obtained. The landing area is marked by a paucity of small craters and an abundance of 'ejecta blocks'. The properties and distribution of ejecta blocks are discussed in a companion paper. The last sequence of images reveals a transition from the blocky surface to a smooth area, which we interpret as a 'pond'. Properties of the 'ponds' are discussed in a second companion paper. The closest image, from an altitude of 129 m, shows the interior of a 100-m-diameter crater at 1-cm resolution.

Iron and colorectal cancer risk: human studies

Some reports have associated iron with cancer risk, particularly of the colorectum. This review will focus on the human studies that have investigated this association. Comparative studies were sought in which people with and without colorectal neoplastic lesions, either cancers or adenomatous polyps, were assessed for iron exposure. Iron exposure variables included dietary iron intake, iron vitamin supplementation, body iron stores as measured by ferritin or transferrin saturation, and gene status for hereditary hemochromatosis. Medline was searched for published reports using the key words iron, cancer, colon, rectum, ferritin, transferrin, and hemochromatosis. In addition, the Cochrane Library was searched for relevant studies and several authors were contacted to investigate their awareness of unpublished studies. Studies were categorized by study design and ranked for quality of innovation in design, sample size, and thoroughness of iron status ascertainment. Thirty-three studies were reviewed in 26 publications. Of the larger studies, approximately three-quarters supported the association of iron, in all three strata of exposure, with colorectal neoplasia risk. Because iron is broadly supplemented in the American diet, the benefits of iron supplementation need to be measured against the long-term risks of increased iron exposure, one of which may be increased risk of colorectal cancer.

Is hereditary hemochromatosis a balanced polymorphism: an analysis of family size among hemochromatosis heterozygotes

BACKGROUND/AIMS

Hereditary hemochromatosis (HH) has a homozygote frequency of 0.5% and a heterozygote frequency of 13%, which suggests that hemochromatosis might be a balanced polymorphism. Evidence for this was sought by assessing reproductive success among hemochromatosis heterozygotes through determining their family size and incidence of miscarriage when compared to nongene carriers.

METHODOLOGY

A cohort was defined in which the exposure variable was heterozygosity for hereditary hemochromatosis. Heterozygotes were identified by mailing individuals homozygous for hereditary hemochromatosis questionnaires concerning the number of siblings born alive and the number of miscarriages suffered by their mothers (predominantly heterozygotes, or HHH). Spouses of the hereditary hemochromatosis homozygotes were asked to complete accompanying questionnaires concerning their mothers (CONT).

RESULTS

Five hundred and ninety-six responses were received from hereditary hemochromatosis homozygotes and 532 responses from spouses of the hereditary hemochromatosis homozygote respondents. The mothers of the hereditary hemochromatosis homozygote respondents had a mean family size of 3.699. The mothers of the unexposed spouse controls a mean family size of 3.639 (P = 0.66 by ANOVA). One hundred and twenty-three of the HHH mothers suffered a total of 201 miscarriages, whereas 94 of the CONT mothers suffered 147 miscarriages (P = 0.38 by ANOVA).

CONCLUSIONS

In this cohort, no evidence among hemochromatosis heterozygotes of reproductive advantage and therefore heterozygous advantage by this mechanism was seen.

Repair of fistulas-in-ano using fibrin adhesive: long-term follow-up

PURPOSE

Fibrin adhesive has been successfully used to treat fistulas-in-ano, but long-term data have been lacking. We report the results of our 18-month study examining the repair of fistulas-in-ano using autologous and commercial fibrin adhesive.

METHODS

A 79-patient, prospective, non-randomized clinical trial was performed in which fibrin adhesive was used to repair fistulas-in-ano. Twenty-six patients were treated with autologous fibrin tissue adhesive made from their own blood, and 53 patients were treated with commercial fibrin sealant. In the operating room the patient underwent an examination under anesthesia, with an attempt to identify the primary and secondary fistula tract openings. The fistula tract was then curetted. Fibrin adhesive was injected into the secondary fistula tract opening until adhesive was seen coming from the primary opening. A petroleum jelly gauze was then applied over both the primary and secondary openings, and the patient was sent home. Follow-up visits occurred one week, one month, three months, and one year later.

RESULTS

Fourteen of 26 (54 percent) patients treated with autologous fibrin tissue adhesive made from their own blood had complete closure of their fistulas after a one-year follow-up, whereas 34 of 53 (64 percent) patients treated with commercial fibrin sealant had closure of their fistulas. Most treatment failures occurred within the first 3 months, but late failures were seen as far as 11 months postoperative.

CONCLUSIONS

Fibrin tissue adhesive offers a unique mode of managing fistulas-in-ano, which is surgically less invasive, but recurrences up to one year later are being seen. Longer follow-up and further research is recommended for improvement.

Dermal island-flap anoplasty for transsphincteric fistula-in-ano: assessment of treatment failures

PURPOSE

The aim of this study was to assess the treatment failures of island-flap anoplasty for fistula-in-ano, a procedure designed to treat fistula without sphincter division.

METHODS

Data concerning all patients having dermal island-flap anoplasty for the treatment of transsphincteric fistula were reviewed. Variables assessed were age, gender, radial fistula location, cause, Crohn's disease, previous fistula operations, other complicating illnesses, internal sphincter closure, simultaneous use of fibrin adhesive injection, and use of combined dermal and rectal flap for large fistulas. Postoperative data collected included persistence of the distal tract, recurrence of the fistula, and treatment of the recurrence. Recurrence (or persistence) of the fistula was the dependant variable and each risk factor for recurrence was assessed using chi-squared analyses.

RESULTS

Seventy-three flaps were performed in 65 individuals. Recurrence developed 17 times in 13 individuals. Recurrence was more likely to occur in males, patients who have had previous treatment of fistulas, patients with large fistulas requiring combined flaps, and patients who had simultaneous fibrin glue injection. Patients with Crohn's disease and individuals having internal sphincter closure had fewer recurrences. Factors reaching statistical significance included closure of the internal sphincter, the use of fibrin glue, and cause of the fistula.

CONCLUSION

No specific anatomic or demographic characteristic is sufficiently associated with failure to exclude any patient from the operation. Closure of the internal sphincter should be done as part of the procedure and fibrin glue injection should not be done simultaneously.

Repair of chronic anorectal fistulae using commercial fibrin sealant

HYPOTHESIS

Commercially produced fibrin sealant can be used to completely close both simple and complex fistulae in ano.

METHODS

A 29-patient prospective nonrandomized clinical trial was performed. In the operating room, the patient underwent an examination with anesthesia and the primary and secondary fistula tract openings were attempted to be identified. The fistula tract was curetted and fibrin sealant was injected into the secondary fistula tract opening until fibrin sealant was seen coming from the primary opening. A petroleum jelly gauze was then applied over the secondary opening and the patient was sent home. Follow-up visits were scheduled for 1 week, 1 month, 3 months, and 1 year later.

RESULTS

Twenty-nine consecutive patients received fibrin sealant injections for their fistulae in ano, with a mean follow-up of 6 months. Two patients had a history of Crohn disease (regional enteritis) and 2 patients had human immunodeficiency virus infection. Overall, 17 (68%) of 25 patients have had successful closure of their fistula with 4 patients lost to follow-up. Two patients required reinjection with fibrin sealant, and neither of these subsequently had closure. One of the 2 patients with Crohn disease had closure, as well as 1 human immunodeficiency virus-positive patient. In addition, there has been no evidence of incontinence or complications related to the use of fibrin sealant in this procedure.

CONCLUSIONS

Initial results in the treatment of chronic anorectal fistulae using commercial fibrin sealant are optimistic, but require further support through longer follow-up data. Fibrin sealant treatment of anorectal fistulae offers a unique mode of management which is safe, simple, and easy for the surgeon to perform. By using fibrin sealant, the patient avoids the risk of fecal incontinence and the discomfort of prolonged wound healing that may be associated with fistulotomy.

Evidence that a dodecamer duplication in the gene HOPA in Xq13 is not associated with mental retardation

A recent study suggested that a dodecamer duplication in exon 42 of the HOPA gene in Xq13 may be a significant factor in the etiology of X-linked mental retardation. In an effort to investigate this possibility, we determined the incidence of the dodecamer duplication in cohorts of non-fragile X males with mental retardation from three countries, cohorts of fragile X males from two countries, 43 probands from families with X-linked mental retardation and control cohorts from three countries. The duplication was found in 3.6-4.0% of male patients from two non-fragile X groups (Italy and South Carolina), in 1.2% from another non-fragile X group (South Africa), but in no male patients from families with X-linked mental retardation (South Carolina). The dodecamer duplication was also found in several white males with fragile X syndrome from France (5%) and South Africa (22.2%). Additionally, the duplication was found in 1.5% of South Carolinian newborn males, 2.5% South Carolinian male college students, 5% Italian male controls and 4.5% of the white South African controls. None of the black South African non-fragile X individuals with mental retardation, the fragile X or the control samples tested carried the duplication, suggesting that the duplication is rare in the black South African population. The incidence of the duplication was not significantly different between any of the groups in the study. Therefore, results of our studies in four different populations do not corroborate the findings of the previous study, and indicate that the HOPA dodecamer duplication does not convey an increased susceptibility to mental retardation.

Stoma complications: the Cook County Hospital experience

PURPOSE

A retrospective analysis of enteric stomas performed at Cook County Hospital was undertaken to evaluate stoma complications per stoma type and configuration and operating service. In addition, we attempted to identify factors predictive of increased enteric stoma complications.

METHODS

From 1976 to 1995, data cards on 1,616 patients with stomas were compiled by Cook County Hospital enteric stomal therapists. Data card information included age, gender, weight, early and late stoma complications, emergency status, operating service, type and configuration of the stoma, and whether the patient was seen preoperatively by an enteric stomal therapist. Data were then analyzed using a logistic regression model to identify those variables that influenced the rate of complications.

RESULTS

There were 553 (34 percent) patients with complications. Among the total complications, 448 (28 percent) occurred early (<1 month postoperative), and 105 (6 percent) occurred late (>1 month). The most common early complications were skin irritation (12 percent), pain associated with poor stoma location (7 percent), and partial necrosis (5 percent). The most common late complications were skin irritation (6 percent), prolapse (2 percent), and stenosis (2 percent). The enteric stoma with the most complications was the loop ileostomy (75 percent). The enteric stoma with the least complications was the end transverse colostomy (6 percent). The general surgery service had the most complications (47 percent), followed by gynecology (44 percent), surgical oncology (37 percent), colorectal (32 percent), pediatric surgery (29 percent), and trauma (25 percent). Age, operating service, enteric stoma type and configuration, and preoperative enteric stomal therapist marking were found to be variables that influenced stoma complications.

CONCLUSIONS

Complications from enteric stoma construction are common. Preoperative enteric stoma site marking, especially in older patients, and avoiding the ileostomy, particularly in the loop configuration, can help minimize complications.

Meta-analysis of operative techniques for fissure-in-ano

PURPOSE

Operative techniques commonly used for fissure-in-ano include anal stretch, open lateral sphincterotomy, closed lateral sphincterotomy, posterior midline sphincterotomy, and to a lesser extent dermal flap coverage of the fissure. Reports of direct comparisons among these techniques are variable in their results and for the most part underpowered. A rigorous analysis of the combined reports was therefore undertaken to determine whether a preferred technique for fissure surgery can be elucidated.

METHODS

MEDLINE was searched for all published reports using the key words "surgery" and "anal fissure." All reports in which there was a direct comparison between at least two operative techniques were reviewed, and when more than one report existed for any given pair, that report was included in the meta-analysis. If crude data were not presented in the report, the authors were contacted, and crude data were obtained. The two most commonly used end points in these reports were persistence of the fissure and postoperative incontinence of flatus. These are the only two end points included in the meta-analysis. The meta-analysis was performed using Epi-Info software obtained from the Centers for Disease Control and Prevention (www.cdc.gov).

RESULTS

Seventeen publications fulfilled the criteria of the study, encompassing 2,727 patients. Significant differences were found for both persistence and incontinence to flatus when comparing anal stretch to all forms of sphincterotomy. No significant difference was found comparing open to closed lateral internal sphincterotomy for persistence or incontinence. Posterior midline sphincterotomy was not significantly different from lateral sphincterotomy related to persistence or incontinence.

CONCLUSION

Internal anal sphincterotomy is superior to anal stretch and should probably be performed in the lateral location, although both the open and closed techniques seem equally efficacious.

Technical manual for manufacturing autologous fibrin tissue adhesive

PURPOSE

The aim of this article is to provide a concise and simple technical manual for manufacturing autologous fibrin tissue adhesive derived from the precipitation of fibrinogen using a combination of ethanol and freezing for surgery.

METHODS

All materials and equipment needed to manufacture ethanol-based autologous fibrin tissue adhesive are listed. In addition, step-by-step instructions are provided to allow for easy and rapid fibrin adhesive production.

RESULTS

Ethanol-based autologous fibrin tissue adhesive can be manufactured in under 60 minutes. Furthermore, at our institution the startup cost for manufacturing ethanol-based autologous fibrin tissue adhesive was under $2,500.00.

CONCLUSION

Ethanol-based autologous fibrin tissue adhesive is a safe, reliable, and easily manufactured autologous fibrin tissue adhesive that can be made by a trained technician in any blood bank, pharmacy, or surgical laboratory.

Universal versus selective gestational diabetes screening: application of 1997 American Diabetes Association recommendations

OBJECTIVE

We sought to evaluate the impact of the 1997 American Diabetes Association gestational diabetes mellitus screening guidelines applied to a universally screened population.

STUDY DESIGN

A retrospective analysis of 18,504 women universally screened for gestational diabetes mellitus at Mayo Clinic, Rochester, between January 1, 1986, and December 31, 1997, was performed. Diabetic screening consisted of plasma glucose determination 1 hour after a 50-g oral glucose challenge. Diagnosis of gestational diabetes mellitus was based on National Diabetes Data Group criteria.

RESULTS

Of 564 cases of gestational diabetes mellitus diagnosed during the study period, 17 (3.0%) would have been missed under the 1997 American Diabetes Association selective screening guidelines while exempting only 10% of this predominantly white population from screening. Screening only women >/=25 years old would have detected 90.4% of gestational diabetes mellitus cases, whereas the addition of the remaining 3 screening criteria combined would have detected only an additional 6.6% of cases.

CONCLUSIONS

The proportion of patients with gestational diabetes mellitus that would remain undiagnosed under the 1997 American Diabetes Association screening guidelines would be relatively small in our population. However, implementation of these guidelines would decrease the number of screens by only 10% while adding significant complexity to the screening process. Youth appears to be the most significant protective factor for gestational diabetes mellitus in our population.

Determination of factors responsible for the declining incidence of colorectal cancer

INTRODUCTION

After rising for 13 years in the United States, the incidence of colorectal cancer began to fall in 1986 and has continued to drop since then. This report contains an analysis of the pattern of declining colorectal cancer risk by colorectal subsite, race, and gender and a time trend investigation of suspected risk modifiers of colorectal cancer.

METHOD

Colorectal cancer incidence data were obtained from the Surveillance, Epidemiology, and End Results Public Use Files from 1973 to 1994. The following exposure variables were assessed, focussing principally on the period 1970 to 1980: dietary fat, fiber, ethanolic beverages, vitamin A, vitamin C, iron, calcium, estrogen, aspirin, energy intake, body mass index, serum cholesterol, body iron stores, cholecystectomy, constipation, cigarette use, physical activity, and colonoscopic polypectomy. Data sources used in these analyses were principally National Health and Nutrition Examination Surveys I, II, and III.

RESULTS

After 1985 colorectal cancer incidence declined predominantly in the distal colorectum almost equally in both white males and white females. Some exposures remained unchanged or trended in the wrong direction (dietary fat, calcium, ethanol, energy intake, physical activity, overweight prevalence, and cholecystectomy). Others did not apply equally to both genders (estrogen, aspirin, ethanol, calcium, and cholecystectomy). Others may become significant in the future, such as aspirin, estrogen, or calcium, because their supplementation is now prevalent, but were not in 1970 to 1975. Of all the risk factors or interventions assessed, the one most consistent with the observed pattern of change is increased use of colonoscopic polypectomy.

CONCLUSION

The best method to diminish the incidence of colorectal cancer today may be to increase the use of screening colonoscopy and polypectomy.

Carcinoma in situ of the colorectum: SEER trends by race, gender, and total colorectal cancer

BACKGROUND AND OBJECTIVES

To determine if Americans of African origin (blacks) have less access to colonoscopic polypectomy than Americans of European origin (whites), the rate of carcinoma in situ of the colorectum (CIS), a disease more similar to benign adenoma of the colorectum than invasive cancer in its symptomatology, discovery, and treatment, was determined in the United States from 1973 to 1994. The hypothesis being tested is that CIS will be far less common in blacks than in whites and that rates of CIS should be increasing in whites from 1973 to 1994.

METHODS

CIS and invasive carcinoma of the colorectum incidence data were obtained from Surveillance, Epidemiology, and End Results (SEER) Public Use Files from 1973 through 1994. Rates were age adjusted and proportions determined by division of CIS rates for each subsite by total carcinoma rates, for each year, race, and gender. The colorectum was divided anatomically in this analysis at the junction of the descending and sigmoid colon.

RESULTS

The relationships between male/female and black/white CIS incidence rates were broadly similar to invasive cancer rates over the 21 years of SEER, demonstrating a white male predominance for distal disease, a black male predominance for proximal disease, and a decline in incidence since 1988. CIS as a proportion of total colorectal cancer increased in all races and genders from 1973 to 1987, but then declined in all groups.

CONCLUSIONS

The majority of CIS is excised by endoscopic resection. Therefore, this might be considered a surrogate population for those individuals who have colonoscopic resection of benign adenomas. It is this latter treatment that has been hypothesized to be the cause for the declining incidence of invasive colorectal cancer. However, data presented herein do not support this hypothesis.

Repair of fistulas-in-ano using autologous fibrin tissue adhesive

PURPOSE

Our goal was to determine if autologous fibrin tissue adhesive derived from the precipitation of fibrinogen using a combination of ethanol and freezing, could be used to completely close both simple and complex fistulas-in-ano.

METHODS

A 26-patient pilot study was performed in which 100 ml of a patient's blood was drawn 90 minutes before surgery. Autologous fibrin tissue adhesive was prepared. In the operating room the patient underwent an examination under anesthesia, and the primary and secondary fistula tract openings were attempted to be identified. The fistula tract was curetted, and autologous fibrin tissue adhesive was injected into the secondary fistula tract opening until fibrin glue was seen coming from the primary opening. A petroleum jelly gauze was then applied over the secondary opening, and the patient was sent home. Follow-up visits were scheduled for one week, one month, three months, and one year later.

RESULTS

Twenty-six patients received autologous fibrin tissue adhesive fistula injections, with a mean follow-up of 3.5 months. Initial results were encouraging. Twenty-one of 26 patients (81 percent) had successful initial closure of their fistulas. Two of five failures were injected a second time, and one closed, giving an overall successful closure rate of 85 percent (22/26 patients). Of five patients who failed, mean time to failure was 3.8 weeks. In addition, there was no evidence of infection or complications related to the procedure.

CONCLUSION

Our initial results are optimistic and require further support through longer follow-up data. Fibrin glue treatment of anorectal fistulas offers a unique mode of management that is safe, simple, and easy for the surgeon to perform. By using autologous fibrin tissue adhesive the patient avoids the risk of anal incontinence and the discomfort of prolonged wound healing which may be associated with fistulotomy.

Time trends in distal colorectal cancer subsite location related to age and how it affects choice of screening modality

BACKGROUND AND OBJECTIVES

A time trend analysis of colorectal cancer (CRC) incidence in the distal colorectum as a proportion of total CRC is presented for the period 1977-1994 as a function of age, to determine the age at which Americans might best be served by screening fiberoptic sigmoidoscopy.

METHODS

CRC incidence rates were obtained for each anatomic subsite from SEER Public Use Files for 1977, 1986, and 1994. The colorectum was divided anatomically for these analyses at the junction of the descending colon and sigmoid colon. Incidence in the distal colorectum was divided by total CRC incidence to determine the proportion of CRC in that age/race/gender/year cohort located in the distal colorectum.

RESULTS

The proportion of distal CRC among African Americans was without a clear trend as they grew older in each of the years of observation and in both genders. However, in whites, with increasing age, the proportion of distal disease declined progressively in both genders, with the greatest decline in 1994. Distal CRC became less prevalent than proximal at about age 72 years in white women and at age 82 in white men in 1994.

CONCLUSIONS

As the white population becomes older, and for African Americans of all ages, more total colon screening modalities are needed, although at the onset of recommended screening, among 50- to 60-year-olds, fiberoptic sigmoidoscopy would appear efficacious.

Sequelae of unrecognized gestational diabetes

OBJECTIVE

Prior studies have suggested that macrosomia is the only morbid condition associated with gestational diabetes and that this association is the result of confounding by maternal obesity rather than a result of gestational diabetes itself. We sought to determine whether unrecognized gestational diabetes is an independent predictor of macrosomia and other perinatal morbid conditions after controlling for confounding variables.

STUDY DESIGN

A retrospective analysis of 472 consecutive cases of gestational diabetes diagnosed between 24 and 30 weeks' gestation was undertaken including 16 prospectively identified but clinically unrecognized cases, 297 cases treated with diet alone, and 76 treated with diet plus insulin. Unrecognized cases were matched to 64 nondiabetic controls for race, age, body mass index, parity, pregnancy weight gain, and gestational age at delivery.

RESULTS

In the unrecognized gestational diabetes group versus the nondiabetic control versus gestational diabetes diet groups rates of large for gestational age infants (44% vs 5% vs 9%, p < 0.0005), macrosomia (44% vs 8% vs 15%, p < 0.01), shoulder dystocia (19% vs 3% vs 3%, p < 0.05), and birth trauma (25% vs 0% vs 0.3%, p < 0.001) were all significantly increased. These differences remained significant after controlling for maternal age, race, parity, body mass index, pregnancy weight gain, and gestational age at delivery.

CONCLUSIONS

This study suggests that unrecognized gestational diabetes increases risks of large for gestational age infants, macrosomia, shoulder dystocia, and birth trauma independent of maternal obesity and other confounding variables. Clinical recognition and dietary control of gestational diabetes are associated with a reduction in these perinatal morbid conditions.

Response of Soybean Accessions from Provinces in Southern China to Phytophthora sojae

Phytophthora rot, caused by Phytophthora sojae, is a damaging disease of soybean (Glycine max (L.) Merr.) throughout the soybean-producing regions of the world. The discovery of new sources of resistance in soybean is vital in maintaining control of Phytophthora rot, because races of the pathogen have been discovered that can attack cultivars with commonly used resistance genes. The objectives of this study were to investigate the distribution and diversity of Phytophthora-resistant soybean in southern China and identify sources that confer resistance to multiple races for implementation into breeding programs. Soybean accessions obtained from southern China were evaluated for their response to races 1, 3, 4, 5, 7, 10, 12, 17, 20, and 25 of P. sojae using the hypocotyl inoculation technique in the greenhouse at Urbana, Illinois in 1996 and 1997. Accessions were identified that confer resistant responses to multiple races of the pathogen. These accessions may provide sources of resistance for control of Phytophthora rot of soybean in the future. The majority of the accessions with resistance to eight or more of the ten races tested were from the provinces of Hubei, Jiangsu, and Sichuan in southern China. Based on the evaluated accessions, these provinces appear to be valuable sources of Phytophthora-resistant soybean.