Finding "Zombies" in Your Database by Confirming Vital Status.

The Alaska Cancer Registry (ACR) conducted a study to identify and correct the vital status of certain cases in its database. These cases were reported as deceased by the original reporting health care facility but were not identified as being deceased using routine death resources. Cases incorrectly reported as deceased are referred to here as "zombies," as they are the "living dead" in the registry database. Zombie cases are problematic as they contribute toward artificially high mortality rates and artificially low survival rates. They are the opposite of "immortals," a term used in the literature to indicate cases that are alive in the registry database but are actually deceased. To start the study, ACR first linked its registry database to the state mortality database, the Social Security Death Index (SSDI), and the National Death Index (NDI). ACR has 3 non-North American Association of Central Cancer Registries (NAACCR) flag fields indicating the status of the linkage with these 3 data sources. ACR was able to identify zombie candidates by selecting deceased cases that did not successfully link with any of these 3 mortality data sources. After all 3 linkages were completed, ACR identified 20 zombie candidates out of 19,590 deceased cases. ACR researched these patients in several state-specific databases and found that 14 of them were true zombies and changed their vital status to alive. Of the remaining 6 deceased cases, 3 died out of country, 2 died in state, and 1 died out of state. ACR recommends that other state registries consider adding these 3 non-NAACCR mortality database flag fields, as they would make searching for zombie cases fairly routine. It would also serve as a way to perform a quality control check on deceased cases that accidentally become alive again after consolidation with a new facility source record.

The capsule of Bacillus anthracis protects it from the bactericidal activity of human defensins and other cationic antimicrobial peptides.

During infection, Bacillus anthracis bacilli encounter potent antimicrobial peptides (AMPs) such as defensins. We examined the role that B. anthracis capsule plays in protecting bacilli from defensins and other cationic AMPs by comparing their effects on a fully virulent encapsulated wild type (WT) strain and an isogenic capsule-deficient capA mutant strain. We identified several human defensins and non-human AMPs that were capable of killing B. anthracis. The human alpha defensins 1-6 (HNP-1-4, HD-5-6), the human beta defensins 1-4 (HBD-1-4), and the non-human AMPs, protegrin, gramicidin D, polymyxin B, nisin, and melittin were all capable of killing both encapsulated WT and non-encapsulated capA mutant B. anthracis. However, non-encapsulated capA mutant bacilli were significantly more susceptible than encapsulated WT bacilli to killing by nearly all of the AMPs tested. We demonstrated that purified capsule bound HBD-2, HBD-3, and HNP-1 in an electrophoretic mobility shift assay. Furthermore, we determined that the capsule layer enveloping WT bacilli bound and trapped HBD-3, substantially reducing the amount reaching the cell wall. To assess whether released capsule might also play a protective role, we pre-incubated HBD-2, HBD-3, or HNP-1 with purified capsule before their addition to non-encapsulated capA mutant bacilli. We found that free capsule completely rescued the capA mutant bacilli from killing by HBD-2 and -3 while killing by HNP-1 was reduced to the level observed with WT bacilli. Together, these results suggest an immune evasion mechanism by which the capsule, both that enveloping the bacilli and released fragments, contributes to virulence by binding to and inhibiting the antimicrobial activity of cationic AMPs.

Stomach Cancer Incidence and Mortality Trends among Circumpolar Nations.

BACKGROUND: Stomach cancer incidence and mortality rates are declining across circumpolar nations, but the burden may not be distributed equally across subpopulations, including Indigenous peoples. Our objective was to examine stomach cancer incidence and mortality trends across circumpolar populations. METHODS: Cancer incidence and mortality data from 1999-2016 were obtained from the Canadian Cancer Registry, Canadian Vital Statistics, CDC WONDER, NORDCAN, Northwestern Russian cancer registries, and National Cancer Reports. The direct method was used to calculate 10-year rolling age-standardized incidence and mortality rates to the world (WHO 2000-2025) and 2011 Canadian standard populations. Standardized incidence rate ratios (SRR) were calculated. Data were stratified by sex, year, and region. U.S. data were broken down by race [White; American Indian/Alaska Native (AIAN)]. Race data were not available from non-U.S. cancer registries. RESULTS: Most populations showed declining incidence and mortality rates over time. Incidence rates among Greenland males and females, Alaska AIAN males and females, and Northern Canadian both sexes were elevated compared with regional counterparts and remained stable. The largest male SRR was observed among Alaska AIAN versus Alaska Whites [SRR = 3.82; 95% confidence interval (95% CI), 2.71-5.37]. The largest female SRR was observed among Alaska AIAN versus Alaska Whites (SRR = 4.10; 95% CI, 2.62-6.43). CONCLUSIONS: Despite stomach cancer incidence and mortality rates declining overall, some northern and Indigenous populations experience elevated and stable incidence and mortality rates. IMPACT: There is a need to address disparities observed among circumpolar subpopulations. Given similarities in incidence, mortality, and risk factor prevalence across circumpolar regions, addressing disparities could benefit from coordinated international action.

Misclassification of sex in central cancer registries.

BACKGROUND: Intrarecord edits on site-sex combinations are a standard tool to identify errors in the coding of sex in cancer registry data. However, the percentage of sex-specific cancers, like cervix, is low (20 percent of total invasive cases). Visual review and follow-back to improve the quality of the sex coding is labor intensive and typically only performed as a special project on subsets of data. The New York State Cancer Registry (NYSCR) created an edit for identifying potential sex misclassification in cancer registry data and has made its components available for use through the North American Association of Central Cancer Registries (NAACCR). The edit uses the most popular male and female first names based on decade of birth to identify potentially miscoded cases. This paper provides a summary of 3 independently conducted assessments of the sex edit at the central cancer registry level and includes a focus on misclassification of sex for breast cancer. METHODS: The sex edit was applied in 3 state cancer registries: Alabama, Alaska, and Florida. Alabama applied the edit to their entire database for 1996-2004 (N = 190,614) and compared the results to external databases available to most cancer registries. Alaska applied the edit to their entire database (N = 46,645) and were able to compare the results to 2 unique, state-based databases (Alaska Permanent Fund Dividend database and State Troopers database). Florida applied the sex edit to a sample of sites (n = 953,074) with particular attention to breast cancer. RESULTS for breast cases were compared to results from an a priori quality control project on Florida male breast cancer cases. Using the Florida data, issues specific to male breast cancer were evaluated. RESULTS: In Alabama, 45 percent of 977 cases flagged as potentially miscoded sex were determined to be miscodes. In Alaska, 19 percent of 88 cases flagged as potentially miscoded sex were determined to be miscodes but the percent of miscoded cases identified by the edit more than doubled in the most recent years of data. For the Florida male breast cancer comparison, the sex edit correctly identified 729 of 903 cases known to be miscoded (81 percent) and was unable to assign a potential sex on the remaining 174 cases-but did not incorrectly flag any cases as miscodes. IMPLICATIONS: The sex edit is a useful tool for identifying cases that require further review to confirm the reported sex code is correct. However, it only assesses 69 percent to 84 percent of cases based on name and, of those flagged, only 19 percent to 45 percent are true misclassifications. But for breast cancer, a site with a skewed male to female ratio, the verified misclassification rate was 100 percent of the male breast cancer cases flagged as potential females. The proper application of the sex edit can improve the quality of the sex variable and can greatly reduce the impact of miscoded sex on gender-skewed sites like male breast cancer.

The role of neutrophils and monocytic cells in controlling the initiation of Clostridium perfringens gas gangrene.

Clostridium perfringens is a common cause of the fatal disease gas gangrene (myonecrosis). Established gas gangrene is notable for a profound absence of neutrophils and monocytic cells (phagocytes), and it has been suggested that the bactericidal activities of these cells play an insignificant role in controlling the progression of the infection. However, large inocula of bacteria are needed to establish an infection in experimental animals, suggesting phagocytes may play a role in inhibiting the initiation of gangrene. Examination of tissue sections of mice infected with a lethal (1 x 10(9)) or sublethal (1 x 10(6)) inoculum of C. perfringens revealed that phagocyte infiltration in the first 3 h postinfection was inhibited with a lethal dose but not with a sublethal dose, indicating that exclusion of phagocytes begins very early in the infection cycle. Experiments in which mice were depleted of either circulating monocytes or neutrophils before infection with C. perfringens showed that monocytes play a role in inhibiting the onset of gas gangrene at intermediate inocula but, although neutrophils can slow the onset of the infection, they are not protective. These results suggest that treatments designed to increase monocyte infiltration and activate macrophages may lead to increased resistance to the initiation of gas gangrene.

Poly-gamma-glutamate capsule-degrading enzyme treatment enhances phagocytosis and killing of encapsulated Bacillus anthracis.

The poly-gamma-d-glutamic acid capsule confers antiphagocytic properties on Bacillus anthracis and is essential for virulence. In this study, we showed that CapD, a gamma-polyglutamic acid depolymerase encoded on the B. anthracis capsule plasmid, degraded purified capsule and removed the capsule from the surface of anthrax bacilli. Treatment with CapD induced macrophage phagocytosis of encapsulated B. anthracis and enabled human neutrophils to kill encapsulated organisms. A second glutamylase, PghP, a gamma-polyglutamic acid hydrolase encoded by Bacillus subtilis bacteriophage PhiNIT1, had minimal activity in degrading B. anthracis capsule, no effect on macrophage phagocytosis, and only minimal enhancement of neutrophil killing. Thus, the levels of both phagocytosis and killing corresponded to the degree of enzyme-mediated capsule degradation. The use of enzymes to degrade the capsule and enable phagocytic killing of B. anthracis offers a new approach to the therapy of anthrax.

Type IV pili-dependent gliding motility in the Gram-positive pathogen Clostridium perfringens and other Clostridia.

Bacteria can swim in liquid media by flagellar rotation and can move on surfaces via gliding or twitching motility. One type of gliding motility involves the extension, attachment and retraction of type IV pili (TFP), which pull the bacterium towards the site of attachment. TFP-dependent gliding motility has been seen in many Gram-negative bacteria but not in Gram-positive bacteria. Recently, the genome sequences of three strains of Clostridium perfringens have been completed and we identified gene products involved in producing TFP in each strain. Here we show that C. perfringens produces TFP and moves with an unusual form of gliding motility involving groups of densely packed cells moving away from the edge of a colony in curvilinear flares. Mutations introduced into the pilT and pilC genes of C. perfringens abolished motility and surface localization of TFP. Genes encoding TFP are also found in the genomes of all nine Clostridium species sequenced thus far and we demonstrated that Clostridium beijerinckii can move via gliding motility. It has recently been proposed that the Clostridia are the oldest Eubacterial class and the ubiquity of TFP in this class suggests that a Clostridia-like ancestor possessed TFP, which evolved into the forms seen in many Gram-negative species.

Effects of Clostridium perfringens alpha-toxin (PLC) and perfringolysin O (PFO) on cytotoxicity to macrophages, on escape from the phagosomes of macrophages, and on persistence of C. perfringens in host tissues.

Clostridium perfringens is the most common cause of clostridial myonecrosis (gas gangrene). Polymorphonuclear cells (PMNs) appear to play only a minor role in preventing the onset of myonecrosis in a mouse animal model of the disease (unpublished results). However, the importance of macrophages in the host defense against C. perfringens infections is still unknown. Two membrane-active toxins produced by the anaerobic C. perfringens, alpha-toxin (PLC) and perfringolysin O (PFO), are thought to be important in the pathogenesis of gas gangrene and the lack of phagocytic cells at the site of infection. Therefore, C. perfringens mutants lacking PFO and PLC were examined for their relative cytotoxic effects on macrophages, their ability to escape the phagosome of macrophages, and their persistence in mouse tissues. C. perfringens survival in the presence of mouse peritoneal macrophages was dependent on both PFO and PLC. PFO was shown to be the primary mediator of C. perfringens-dependent cytotoxicity to macrophages. Escape of C. perfringens cells from phagosomes of macrophage-like J774-33 cells and mouse peritoneal macrophages was mediated by either PFO or PLC, although PFO seemed to play a more important role in escape from the phagosome in peritoneal macrophages. At lethal doses (10(9)) of bacteria only PLC was necessary for the onset of myonecrosis, while at sublethal doses (10(6)) both PFO and PLC were necessary for survival of C. perfringens in mouse muscle tissue. These results suggest PFO-mediated cytotoxicity toward macrophages and the ability to escape macrophage phagosomes may be important factors in the ability of C. perfringens to survive in host tissues when bacterial numbers are low relative to those of phagocytic cells, e.g., early in an infection.

Multiple effects on Clostridium perfringens binding, uptake and trafficking to lysosomes by inhibitors of macrophage phagocytosis receptors.

Clostridium perfringens is a Gram-positive, anaerobic bacterium that is the most common cause of gas gangrene (clostridial myonecrosis) in humans. C. perfringens produces a variety of extracellular toxins that are thought to be the major virulence factors of the organism. However, C. perfringens has recently been shown to have the ability to survive in a murine macrophage-like cell line, J774-33, even under aerobic conditions. In J774-33 cells, C. perfringens can escape the phagosome and gain access to the cytoplasm. Since the receptor that is used for phagocytosis can determine the fate of an intracellular bacterium, we used a variety of inhibitors of specific receptors to identify those used by J774-33 cells to phagocytose C. perfringens. It was found that the scavenger receptor and mannose receptor(s) were involved in the phagocytosis of C. perfringens. In the presence of complement, the complement receptor (CR3) was also involved in the binding and/or uptake of C. perfringens. Since the receptor inhibition studies indicated that the scavenger receptor played a major role in phagocytosis, C. perfringens binding studies were performed with a Chinese hamster ovary (CHO) cell line expressing the mouse SR-A receptor. The cell line expressing the SR-A receptor showed a significant increase in C. perfringens binding in comparison to the non-transfected CHO cells. In the absence of opsonizing antibodies, the Fc receptor was not used to phagocytose C. perfringens. Forcing the macrophages to use a specific receptor by using combinations of different receptor inhibitors led to only a slight increase in co-localization of intracellular C. perfringens with the late endosome-lysosome marker LAMP-1. Carbohydrate analysis of C. perfringens strain 13 extracellular polysaccharide confirmed the presence of mannose and negatively charged residues of glucuronic acid, which may provide the moieties that promote binding to the mannose and scavenger receptors, respectively.