Loss of heterozygosity of DNA repair gene, hOGG1, in renal cell carcinoma but not in renal papillary adenoma.

The kidney is constantly exposed to free radicals due to its active metabolism and processing of toxic metabolites. Among 20 or so free radical-induced DNA lesions, 8-oxoquanine is the most abundant and is potentially mutagenic if not sufficiently removed. The human 8-oxoquanine DNA glycosylase 1 (hOGG1) gene repairs 8-oxoguanine and resides at 3p25-26, which has frequent loss of heterozygosity (LOH) in clear cell-renal cell carcinoma (CC-RCC). Even though some studies found similar genetic alterations between renal papillary adenomas (PA) and papillary RCC (PRCC), no studies have been conducted to compare the alterations of hOGG1 gene in PA, PRCC and CC-RCC. To further explore the relationship between CC-RCC, PRCC and PA at the genetic level LOH of hOGG1 gene was investigated in these three groups. It was found that 8/8 PRCC (100%) and 8/9 CC-RCC (88%) had evidence of hOGG1 LOH, whereas all four PA (0%) were devoid of hOGG1 LOH. It is concluded that deletion of hOGG1 gene occurs commonly in PRCC and CC-RCC but not in renal cortical PA. Further studies are warranted to further explore the exact roles of hOGG1 gene in the development and progression of RCC.

First-receiver hospital decontamination: an 8-step approach to a progressive and practical program.

The effectiveness of hospital decontamination programs begins with planning, preparation, and practice. A well-thought-out hospital decontamination program encompasses complexities that are not always apparent. In disaster situations, the victim, hospital, patients, and staff are placed at serious risk if untrained, unprepared employees perform emergency decontamination procedures at the hospital-receiving site. The authors describe 8 steps to developing an emergency preparedness program and team with decontamination capabilities to facilitate emergency response in the first-receiver hospital.

Molecular detection of Campylobacter jejuni in archival cases of acute appendicitis.

The role of enteric bacteria in the pathogenesis of acute appendicitis is a controversial subject. Campylobacter jejuni has been previously demonstrated in a minority of cases of acute appendicitis using microbiological or immunohistochemical methods, notably in cases where inflammation was limited to the mucosa/submucosa. Our goal was to evaluate cases of acute appendicitis for C. jejuni DNA using molecular methods, and to compare our findings to the histologic features. In total, 50 archival cases of acute appendicitis were selected, and PCR was performed using primers targeting a 286-bp fragment of the mapA gene specific to C. jejuni. Twenty histologically unremarkable appendectomy specimens served as negative controls. Cases were reviewed with attention to particular histological features including mucosal ulceration, cryptitis, depth of inflammatory infiltrate, and the presence of mural necrosis. Of acute appendicitis cases, 22% (11/50) were positive for C. jejuni DNA by PCR analysis. Control cases were negative for C. jejuni DNA. All patients presented with signs and symptoms typical of acute appendicitis. Of the C. jejuni positive cases, only 27% contained acute inflammation limited to the mucosa/submucosa, whereas the remainder had mural or transmural inflammation; therefore, the histological features of C. jejuni-positive acute appendicitis cases were indistinguishable from C. jejuni-negative cases. In summary, C. jejuni DNA was detected in a significant percentage (22%) of acute appendicitis cases, a much higher percentage than previous studies using other methodologies. As C. jejuni is an enteric pathogen that does not exist as a commensal or nonpathogenic organism, the presence of C. jejuni DNA implies current or recent infection. Further study is needed to determine whether the presence of C. jejuni DNA in acute appendicitis indicates appendiceal involvement by C. jejuni enteritis, or if there is a true causative role for C. jejuni in acute appendicitis.

Molecular diagnosis of Campylobacter jejuni infection in cases of focal active colitis.

Campylobacter jejuni (CJ) is the most commonly isolated stool pathogen in the United States. Biopsy findings are typically those of focal active colitis (FAC), a nonspecific pattern usually indicating infection or adverse drug effect that is characterized by focal cryptitis and preservation of crypt architecture. We developed a molecular test for CJ that can be performed on routinely processed gastrointestinal biopsy specimens, and assessed what percentage of patients with biopsy findings of FAC have molecular evidence of CJ infection. One hundred and ten colon biopsies diagnosed as FAC were retrieved from three institutions. Polymerase chain reaction (PCR) was performed following DNA extraction; primers were designed to target a 286-bp fragment of the mapA gene that is specific to CJ. Pure genomic DNA derived from cultures served as the positive control; reagent blanks and 50 normal colon specimens served as negative controls. Nineteen percent (21/110) of the FAC biopsies were positive for CJ DNA by PCR analysis. Fourteen CJ-positive patients presented with diarrhea, 3 presented with gastrointestinal bleeding, and 3 had incidental FAC found on screening colonoscopy. Ten patients had abnormal colonoscopic findings, including erythema (4), ulcers (4), colitis (1), and hemorrhage (1). As CJ is an enteric pathogen that is not present in the gut as a commensal organism, the presence of CJ DNA suggests current or recent previous infection in these patients. CJ infection should be considered in patients with diarrhea and colon biopsies showing FAC. Furthermore, PCR analysis performed on fixed, routinely processed colon biopsies is an excellent diagnostic method for detection of this organism.

Molecular biogrouping of pathogenic Yersinia enterocolitica: development of a diagnostic PCR assay with histologic correlation.

Yersinia enterocolitica (YE) is associated with several inflammatory gastrointestinal disorders. Pathogenic YE organisms are classified as biogroup 1B (high-virulence [HV] serovars) or biogroups 2 through 5 (low virulence [LV]). We developed the first molecular assay designed to distinguish between these groups and correlated the molecular results with histologic patterns of inflammation. Eleven known pathogenic YE culture isolates (6 biogroup 1B and 5 biogroups 2-5) and 6 YE-positive archival cases were subjected to polymerase chain reaction analysis using primer pairs targeting a strain-dependent variable region, allowing discrimination between biogroups with a single assay. All 11 known culture isolates were confirmed. Of the 6 archival cases, 4 were LV, and 2 were HV. Histologic correlation revealed granulomatous inflammation in the LV cases and suppurative inflammation in the HV cases. This novel assay is useful for diagnosis using culture samples and archival tissues. It also could yield important information correlating YE epidemiology, pathogenesis, and morphology because these preliminary data suggest that LV strains may be associated with chronic granulomatous processes and HV strains with suppurative inflammation.

Mycobacteria other than Mycobacterium tuberculosis are not present in erythema induratum/nodular vasculitis: a case series and literature review of the clinical and histologic findings.

Erythema induratum (EI)/nodular vasculitis (NV) is characterized by recurrent crops of tender oedematous nodules on the lower legs. A lobular panniculitis with granulomatous inflammation, vasculitis, focal necrosis and septal fibrosis is present. Mycobacterium tuberculosis DNA has been detected in some lesions by means of polymerase chain reaction (PCR). Ten cases of EI/NV were found. H&E slides were reviewed. PCR assays for M. tuberculosis and mycobacteria other than M. tuberculosis (MOTT) were performed. PCR did not reveal M. tuberculosis (0%) or MOTT (0%) DNA, with positive controls, indicating the reliability of the assays. Among the MOTT, cutaneous infections are most commonly caused by M. marinum. Subcutaneous tuberculoid granulomas may be seen with M. kansasii, M. marinum, M. scrofulaceum and M. avium complex. M. gordonae, M. szulgai and M. malmoense rarely cause cutaneous infections. M. simiae, M. gastri and M. asiaticum are probably not cutaneous pathogens. M. tuberculosis and MOTT DNA was not found in EI/NV. EI/NV has diverse aetiologies with varying pathogeneses leading to similar histologic changes. The cases analysed may not have had an infectious aetiology. However, in EI/NV, performance of PCR for MOTT as well as M. tuberculosis complex may still be beneficial, particularly in cases from immunocompromised hosts.

Cat-scratch disease: historic, clinical, and pathologic perspectives.

Cat-scratch disease (CSD) initially was described in 1931, but the etiologic agent (Bartonella henselae) was not elucidated until decades later. This disease is the most common cause of chronic lymphadenopathy among children and adolescents, characteristically manifesting as subacute regional lymphadenitis with an associated inoculation site due to a cat scratch or bite, often accompanied by fever. The hallmark histologic lesion is granulomatous inflammation with a central stellate microabscess. Numerous atypical manifestations of CSD have been described, and these often lack the characteristic superficial lymphadenopathy and inoculation site papule. These atypical forms may be misdiagnosed initially as other infectious processes or neoplasms. We present a review of the history and epidemiologic features of CSD, describe common and unusual clinicopathologic manifestations, and discuss current diagnostic modalities.

Histologic and molecular diagnosis of tularemia: a potential bioterrorism agent endemic to North America.

Francisella tularensis (FT), a zoonotic bacterium that causes tularemia, has received attention as a possible bioterrorism threat. We developed a PCR assay for use in fixed, processed tissues, which are safer to handle and allow archival testing. PCR analysis for a 211-bp fragment of the FT lipoprotein gene was performed on tissues from 16 cases of tularemia. In all, 14/15 cases with intact DNA (93%) were positive for FT by PCR. Frequent histologic findings in PCR-positive tissues included irregular microabscesses and granulomas in liver, spleen, kidney, and lymph nodes, and necrotizing pneumonia. Unusual cases featuring suppurative leptomeningitis and gastrointestinal ulcers were also seen. As this disease is endemic in North America, and has been identified as a potential bioterroristic threat, awareness of the clinicopathologic spectrum of disease and available detection methods is increasingly important. This PCR assay, the first designed for use in processed tissues, is an excellent method for diagnosis of tularemia.

Pathogenic Yersinia DNA is detected in bowel and mesenteric lymph nodes from patients with Crohn's disease.

Previously, we detected pathogenic (invasive) DNA in the appendices of two patients who later developed Crohn's disease (CD). This subsequent investigation is the first to evaluate a series of specimens from CD patients for the presence of pathogenic DNA. A total of 54 intestinal resection specimens from 52 patients with confirmed CD were evaluated. Lesional tissue was tested by polymerase chain reaction analysis for the presence of genes occurring only in pathogenic Primer pairs are specific for each species, with no known cross reactions with other bacteria. Forty normal bowel specimens, 30 cases of acute appendicitis, and 50 cases of various active colitides served as disease controls. Medical records were reviewed following polymerase chain reaction and histologic evaluation. A total of 17 of 54 resections (31%) contained DNA by polymerase chain reaction. Mesenteric lymph nodes were also positive in eight of these cases. All controls were negative. -positive patients had carried the diagnosis of CD for a median of 10 years before resection (range 1 month to 40 years). We report the first documentation of DNA in a series of CD cases. Further studies are needed, including serial study, over time, of -positive CD patients, as well as prospective studies of newly diagnosed CD patients for evidence of infection. Like previous studies associating infectious organisms with CD, much work remains to elucidate whether the presence of DNA is an epiphenomenon or actually a factor in the pathogenesis of CD.

Fatal meningitis and encephalitis due to Bartonella henselae bacteria.

Bacterial infection due to Bartonella henselae commonly develops in children and young adults following cat/dog contacts and/or cat/dog scratches. Regional lymphadenopathy is its most common clinical expression. However, encephalitis and Parinaud's syndrome (oculoglandular syndrome) have also been reported as has systemic illness. A review of the international literature in all languages revealed no fatal complications in immunocompetent hosts. A four-year-old white child with no underlying illness began to have seizure-like activity. She was taken to a local hospital and subsequently transferred to a medical center. The child was treated aggressively for seizures and fever of unknown origin. However, her condition rapidly declined and she died without a specific diagnosis. At autopsy there was marked cerebral edema with no gross evidence of acute meningitis. Microscopic exams revealed multiple granulomatous lesions as well as a meningitis and encephalitis. A variety of cultures and stains were negative for acid fast and fungal organisms. Warthin-Starry stains of involved tissue including brain and liver revealed pleomorphic rod shaped bacilli consistent with Barronella henselae. Analysis of brain tissue with polymerase chain reaction (PCR) and Southern blot for the deoxyribonucleic acid (DNA) was definitive for DNA of Bartonella henselae bacteria.