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Biomedical subjects

G W Procop

Publications and source records attributed to G W Procop.

At least 37 records · Page 2Linked to original sources

Validation of a multicolor interphase fluorescence in situ hybridization assay for detection of transitional cell carcinoma on fresh and archival thin-layer, liquid-based cytology slides.

OBJECTIVE: To evaluate the feasibility of performing multicolor interphase fluorescence in situ hybridization (FISH) on ThinPrep slides of transitional cell carcinoma (TCC). STUDY DESIGN: Slides from 20 voided urine specimens were prepared by the ThinPrep technique (Cytyc, Boxborough, Massachusetts, U.S.A.), pretreated using a pretreatment kit and subjected to hybridization with the multicolor FISH probe UroVysion (Vysis, Downers Grove, Illinois, U.S.A.). Archival slides were placed in xylene, destained in alcohol and washed prior to pretreatment. Urines from patients with cytology-positive, biopsy-proven grade 1 (n = 5), 2 (n = 7) and 3 (n = 5) TCC and negative cytology and biopsy (n = 3) were selected. Freshly prepared (n = 10) and archival (n = 10) slides were used. RESULTS: All carcinoma cases were FISH positive (> 5 cells with complex abnormalities of > or = 2 studied chromosomes per slide). None of the normal samples were aneusomic. Gain of chromosomes 3, 7 and 17 constituted the majority of positive cases. Proper destaining and slight decrease in stringency wash conditions enabled reliable detection of signals in archival cases. CONCLUSION: Routine ThinPrep slides can be used for multicolor interphase FISH analysis of urine cytology specimens. Archival slides provide the opportunity to analyze by FISH the nature of atypical cells identified by cytology. This revised method allows FISH technology more accessibility for routine use in cytology laboratories.

Carcinoma, Transitional Cell↗

Antimicrobial susceptibility of Abiotrophia adiacens and Abiotrophia defectiva.

The susceptibilities of 27 Abiotrophia adiacens (proposed reclassification Granulicatella adiacens comb.nov., Collins & Lawson, 2000) and 12 Abiotrophia defectiva isolates were tested by microdilution in pyridoxal hydrochloride and lysed horse blood supplemented Mueller-Hinton broth. According to NCCLS interpretative criteria for Streptococcus spp. not Streptococcus pneumoniae, the susceptibilities of A. adiacens and A. defectiva were, respectively: penicillin, 55% and 8%; amoxicillin, 81% and 92%; ceftriaxone, 63% and 83%; meropenem, 96% and 100%; and 100% for both species with clindamycin, rifampin, levofloxacin, ofloxacin, quinupristin/dalfopristin, and vancomycin.

Anti-Bacterial Agents↗

Screening and confirmatory testing for extended spectrum beta-lactamases (ESBL) in Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca clinical isolates.

Escherichia coli and Klebsiella spp. were screened for ESBL based on routine susceptibility testing results. Isolates with intermediate or resistant susceptibilities for extended spectrum cephalosporins or aztreonam were reported as probable ESBL producers. By using the NCCLS proposed ESBL confirmatory method, we tested 61 screen-positive isolates from 42 patients, 30 randomly selected susceptible isolates, and 12 isolates with previously characterized beta-lactamases. Ceftazidime contributed to 97% of screen-positive isolates, whereas aztreonam added a single patient isolate. An ESBL was confirmed in 86% of K. pneumoniae, 100% of K. oxytoca, and 20% of E. coli screen-positive single patient isolates. None of the susceptible isolates were shown to produce ESBL. Based on these findings a comment regarding the presence of ESBL seems sufficient for Klebsiella spp. but confirmatory testing is indicated for E. coli. 0.25 microg/mL was used to indicate the presence of ESBL, the specificity of the assay increased to 100%. The NCCLS ESBL phenotypic confirmatory method was reproducible and accurate enough to be used in the clinical laboratory.

Anti-Bacterial Agents↗

Performance of five agar media for recovery of fungi from isolator blood cultures.

We studied the recovery of 1,270 fungal isolates from 176,144 Isolator blood cultures (0.72% positive) on bacterial and fungal media, under routine and differing incubation conditions. Except with Histoplasma capsulatum, chocolate agar incubated for only 3 days proved to be an excellent medium for the recovery of fungi from the Isolator system.

Agar↗

Evaluation of the Alexon-trend ProSpecT Campylobacter microplate assay.

We evaluated stool specimens known to contain or be free of Campylobacter by traditional culture, using the ProSpecT Campylobacter microplate assay (Alexon-Trend, Ramsey, Minn.). This rapid enzyme immunoassay for the detection of Campylobacter-specific antigens demonstrated 96% sensitivity and 99% specificity and is an acceptable alternative method of Campylobacter detection.

Antigens, Bacterial↗

Ciliocytophthoria in clinical virology.

Direct immunofluorescence assays (DFAs) are used in the clinical virology laboratory for the rapid detection of viruses. An assessment of the cellularity of specimens submitted for DFA is necessary for the most effective use of this assay. This assessment ensures that an adequate number of the appropriate cells are present for examination. During this assessment, clinical virologists may encounter unfamiliar cellular elements or cellular fragments. One of these elements, ciliocytophthoria, has been misinterpreted as a parasite in specimens submitted for cytologic testing. We describe a similar case in which a technologist thought that ciliocytophthoria possibly represented a ciliated parasite in a nasopharyngeal specimen sent for respiratory syncytial virus DFA. After a thorough morphologic examination, the staff dismissed the possibility of a ciliated parasite. We confirmed this entity as ciliocytophthoria using morphologic criteria and the Diff-Quik stain. This near misidentification of ciliocytophthoria as a ciliated parasite affords us the opportunity to raise the awareness of clinical virologists about ciliocytophthoria. Additionally, we briefly review useful features for differentiating ciliocytophthoria from the only ciliate parasitic for humans, Balantidium coli. Finally, we present the utility of a commonly used cytologic stain, the Diff-Quik stain, for the confirmation of ciliocytophthoria.

Artifacts↗

Relationship of HHV8 replication and Kaposi's sarcoma after solid organ transplantation.

HHV8 DNA sequences have recently been isolated from all types of Kaposi's sarcomas, and its association in the etiopathogenesis of this tumor has been established. However, little is known about the regulation of HHV8 replication in immunocompromised patients seropositive for this virus, and its impact on the development of Kaposi's sarcoma (KS). Through the study of a heart transplant patient who developed KS and in whom peripheral blood lymphocytes (PBLs) had been prospectively collected before and after transplantation, we have investigated the pathogenesis of HHV8. Our results indicate that (i) HHV8 can reactivate soon after transplantation; (ii) viral replication, as determined by quantification of HHV8 DNA load of PBLs, increases significantly after transplantation; and (iii) increased HHV8 DNA levels in PBLs are associated with the development of KS.

DNA, Viral↗

Diagnostic value of a miracidium in urinary sediment.

Although rarely encountered in the United States, urinary tract schistosomiasis occurs commonly in many countries in the eastern hemisphere. Travel and immigration may contribute to imported cases of schistosomiasis. Excessive morbidity and increased mortality, including the development of urinary-tract squamous-cell carcinoma, are associated with untreated Schistosoma haematobium infection. Therefore, in the appropriate clinical context, all efforts should be made to rule out infectious and readily treatable causes of chronic hematuria. The presence of characteristic eggs in the urinary sediment is the usual means of diagnosing a S. haematobium infection. Additionally, the small and less commonly encountered miracidium stage of S. haematobium may also be present in the urine, which is another means of diagnosing urinary tract schistosomiasis. The present report describes a case in which a miracidium was detected in a fresh, unstained urine specimen. As detection of miracidia can be made in specimens also processed by routine cytologic methods, it behooves cytologists to be aware of this entity for the diagnosis of schistosomiasis.

Adolescent↗

Amplicor enterovirus polymerase chain reaction in patients with aseptic meningitis: a sensitive test limited by amplification inhibitors.

OBJECTIVE: To evaluate the sensitivity and specificity of reverse-transcription polymerase chain reaction (RT-PCR) and routine cell culture for the detection of enterovirus in cerebrospinal fluid. METHODS: Thirty-eight cerebrospinal fluid specimens were included. Cell culture was inoculated immediately and incubated for 14 days. An aliquot was kept frozen for Amplicor RT-PCR. Chart review was performed to determine the validity of the results. RESULTS: Nine of 38 specimens were positive for enterovirus by culture, and 14 were positive by RT-PCR. There were 7 discrepancies between the 2 methods. Six specimens were positive by RT-PCR and negative by the culture method. The 1 culture-positive but RT-PCR--negative specimen was determined to contain PCR inhibitors. All discrepant results were confirmed as true positives by chart review. Patients whose cerebrospinal fluid was negative by both methods had a final diagnosis other than enterovirus infection. CONCLUSION: Amplicor PCR is more sensitive than cell culture (93.3% vs. 60%) and is very specific. With the incorporation of appropriate controls for the detection of amplification inhibitors, RT-PCR could be a valuable tool in the diagnosis of enteroviral meningitis.

Cell Culture Techniques↗

Histologic parameters predictive of mycobacterial infection.

Tissue specimens from a wide variety of anatomic locations are frequently examined for mycobacteria using a combination of cultures and special stains. Auramine-rhodamine (AR) staining is a sensitive method for detecting acid-fast bacilli (AFB) in tissue sections. We reviewed 85 AR-positive and 275 randomly selected AR-negative biopsy specimens collected during the past 2 years at the Mayo Clinic, Rochester, Minn. Pathologic diagnoses and culture results were also reviewed. Biopsy specimens containing necrotizing granulomas yielded the highest positivity rate for AFB (61 [47.7%]), followed by nonnecrotizing granulomas (14 [17.7%]). Poorly formed granulomas (5 [16.1%]) and acute inflammation (5 [15.6%]) were less frequently positive. Cases with fibrotic or hyalinized granulomas, nonspecific chronic inflammation, nonspecific reactive or reparative changes, no significant histologic abnormality, or malignancy failed to disclose AFB. These specimens, which were consistently negative for AFB, were responsible for 25% of the samples submitted. Of the 360 tissue specimens submitted, 166 had a corresponding mycobacterial culture. Mycobacteria were cultured only from the biopsy specimens that contained necrotizing granulomas (38.2%), nonnecrotizing granulomas (32.4%), poorly formed granulomas (30.0%), or acute inflammation (15.8%). Tissues with fibrotic or hyalinized granulomas, nonspecific chronic inflammation, nonspecific reactive or reparative changes, no significant histologic abnormality, or malignancy failed to yield positive cultures. These data suggest that biopsy specimens with these latter diagnoses are inappropriate specimens for mycobacterial culture or AR staining.

Acute Disease↗

Detection and semiquantitative analysis of human herpesvirus 8 DNA in specimens from patients with Kaposi's sarcoma.

Kaposi's sarcoma (KS) is the most common neoplasm in patients with AIDS. Epidemiologic evidence and the recent identification of herpesvirus-like DNA sequences in patients with KS have suggested a role for viral agents in the etiopathogenesis of this disease. It is unclear if these sequences are present in all types of KS and if the copy number of these sequences has a correlation with disease severity (staging). In order to clarify these issues, we retrospectively analyzed, by PCR and Southern blotting, formalin-fixed, paraffin-embedded biopsy specimens from 12 patients previously diagnosed with KS by histopathologic examination of these specimens between the years of 1977 and 1996. We also analyzed tissue samples from these patients taken from dermal sites without KS lesions and control tissues from healthy subjects. Of the 12 patients, 6 had classic KS, 5 had AIDS-associated KS, and 1 had the endemic type of KS. We tested the specimens for other herpesviruses, including cytomegalovirus, human herpesvirus 6 (HHV-6), HHV-7, HHV-8, and Epstein-Barr virus. Of 20 biopsy specimens from patients previously diagnosed with KS, 19 were positive for HHV-8 sequences (95%), while PCR for the DNAs of other herpesvirus agents was negative. Uninvolved tissue from these patients and control tissue from healthy subjects gave negative results for all viruses. Semiquantitative analysis of Southern blots showed higher levels of HHV-8 DNA in those patients with multicentric and visceral involvement than in those patients with localized involvement. In addition, in patients with localized skin disease, the nodular stage had higher levels of HHV-8 DNA than the patch or plaque stages. Our data confirmed that HHV-8 is involved in the etiopathogenesis of all types of KS and that there is a correlation between HHV-8 DNA load and the severity and staging of this disease.

AIDS-Related Opportunistic Infections↗

Diagnostic value of conidia associated with pulmonary oxalosis: evidence of an Aspergillus niger infection.

Bronchoalveolar lavage (BAL) material is commonly received in cytopathology for the exclusion of microorganisms. When crystalline material suggestive of calcium oxalate is present in the specimen, a search for fungal elements should be undertaken. Aspergillus niger is the hyaline mold associated with the presence of oxalate crystals. Commonly fragments of hyphae and occasionally entire conidiophores may be present in BAL specimens from patients with aspergillosis. We report a case of a patient with saprophytic colonization of a bullous/cavitary lesion. The BAL consisted of abundant acute inflammation, crystalline material suggestive of oxalate, and darkly pigmented conidia. Although an extensive search was undertaken, hyphal fragments could not be found. The suspicion of an A. niger infection was confirmed by culture. We believe that even in the absence of hyphal fragments, darkly pigmented, occasionally rough-walled conidia are sufficient evidence to be highly suspicious of an A. niger infection in patients with pulmonary oxalosis.

Aspergillosis↗

Laboratory tests in evaluation of acute febrile illness in pediatric emergency room patients.

The rising costs of health care and the movement for health care reform have focused attention on methods of cost containment. Of routine laboratory and radiologic procedures, complete blood cell count (CBC) and determination of serum electrolyte values rank as high as 2nd and 9th in overall cost. We retrospectively studied use of the clinical laboratory to aid diagnosis of an acute infectious event in a pediatric emergency department population. For 5 months, we reviewed medical records of pediatric patients younger than 15 years brought to the emergency department because of a febrile episode. Of 155 cases reviewed, electrolyte concentrations were determined in 108 patients and CBC in 155. In all patients, either culture or rapid test for streptococcal organisms was performed. In addition, 838 pediatric patients with similar symptoms but who did not undergo laboratory testing were monitored for 100 days. Measures of effectiveness including sensitivity, specificity, positive and negative predictive values, and likelihood ratio were used to correlate specific laboratory findings with antibiotic therapy, serious bacterial disease, and culture positivity. Electrolyte abnormalities were found largely to be dismissed clinically, with the major clinical response consisting of parental education about hydration. The CBC profile was evaluated, with white blood cell count (WBC) indicator limits of > 10,000, > 10,000 but < 15,000, and > 15,000/mm3, and differentiated into absolute neutrophil count, neutrophil percent, and band cell percent. Temperature was evaluated as an independent variable. Insofar as serious bacterial disease and culture positivity, sensitivity was uniformly low (70%), and specificity was only marginably acceptable for WBC > 15,000 (77%). Both positive predictive values and likelihood ratio were low with respect to predicting either serious bacterial disease or culture positivity, emphasizing the limited usefulness of these clinical laboratory measurements. The best hematologic predictors of serious bacterial disease or culture positivity were obtained with automated hematologic analyzers and exceeded manual differential measurement of neutrophil percent and band cell percent. In addition, we correlated the administration of antibiotics with the various hematologic parameters and discovered that WBC > 15,000, regardless of cause, almost uniformly resulted in treatment (positive predictive value, 93.5%; likelihood ratio, 5.60). These findings support the use of automated hematology analyzer-derived measurements and question the use of manual differential counts, unless specific issues are to be addressed. Furthermore, the findings seem to support more reliance on clinical impression and less on laboratory values.

Acute Disease↗

Immunoperoxidase and immunofluorescent staining of Rickettsia rickettsii in skin biopsies. A comparative study.

OBJECTIVE: To compare immunofluorescent and immunoperoxidase staining of Rickettsia rickettsii in skin biopsies of patients suspected of having Rocky Mountain spotted fever (RMSF). DESIGN: Immunofluorescent staining results for R rickettsii from skin biopsies of patients suspected of having RMSF were obtained by computer and chart review. Immunoperoxidase staining for R rickettsii was performed on formalin-fixed, paraffin-embedded skin biopsies from the same patient population. PATIENTS: Twenty-six patients who were clinically suspected of having RMSF were included in this study. Skin biopsies of these patients were examined for evidence of RMSF by immunofluorescence and routine histology. MAIN OUTCOME MEASURES: The sensitivity and specificity of both immunofluorescent and immunoperoxidase staining techniques were calculated. The chi 2 method was used to assess significance. RESULTS: Both tests were highly significant for the detection of R rickettsii (P < .01). The sensitivity and specificity of the immunofluorescent and immunoperoxidase staining techniques for the identification of RMSF were identical. No significant difference between these tests was identified (P > .05). CONCLUSION: The sensitivity and specificity of immunofluorescent and immunoperoxidase staining of R rickettsii in routinely processed, paraffin-embedded skin biopsies of patients suspected of having RMSF are identical. Although not as rapid as the immunofluorescent technique, immunoperoxidase staining of R rickettsii has advantages over the immunofluorescent technique; these include easier antigen localization and concomitant viewing of the corresponding histopathology.

Biopsy↗