Protein profiling of non-malignant and malignant ascites by SELDI-TOF MS: proof of principle.

Ascites is a common clinical symptom in liver cirrhosis, inflammatory disorders of the abdomen and a major late manifestation of metastatic malignancies. Standard cytopathological techniques and immunocytochemistry have specificities and sensitivities of approximately 95 and 60%, respectively for the presence of tumor cells. Development of faster and more accurate screening methods would be of great clinical utility. In this work we examined differential analysis of the unbound proteins in the supernatant of ascites fluid by Protein-Chip SELDI mass spectrometry. There were 21 tumor cell-positive and 34 tumor cell-negative samples. We used principal component analysis coupled with linear regression applied to the mass spectra of the samples to distinguish between the sample groups. Two sample sets for statistical analysis were created after randomization, a training set with 37 samples and a validation set with 18 samples resulting in a specificity of 93% and a sensitivity of 83% on the training set. The validation set yielded a specificity and sensitivity of 75%. This study suggests that SELDI-TOF mass spectrometry appears to have great potential as a surrogate diagnostic tool to evaluate effusion specimens.

Telomerase is a highly sensitive and specific molecular marker in fine-needle aspirates of breast lesions.

PURPOSE: Telomerase has been detected in a majority of human malignant tumors, making telomerase activity (TA) one key difference between mortal and immortal cells. In this study, we evaluated in blind-trial fashion the association of TA with cytologic and final clinical/pathologic diagnosis in fine-needle aspirates (FNAs) of breast lesions. MATERIALS AND METHODS: In 172 FNAs, including 80 samples that were cytologically malignant, 18 that were atypical but not diagnostic for malignancy, and 74 that were cytologically benign, TA was determined by a modified nonradioactive telomeric repeat amplification protocol (TRAP) assay. Final diagnosis was made by pathologic examination of follow-up surgical material available for all the cytologically malignant samples, a majority of the cytologically atypical samples, and a portion of the cytologically benign samples. RESULTS: TA was detected in 85 of 172 samples. Comparison of the cytologic and histologic diagnoses with TA showed that 80 of 87 samples from patients with breast cancer were telomerase-positive, resulting in a sensitivity of 92%. TA was found in four of five FNAs from carcinomas that were considered cytologically atypical but not diagnostic for malignancy. Eighty of 85 samples from patients with benign breast lesions were telomerase-negative, revealing a specificity of 94%. The five positive cases in this group were all fibroadenomas with low TA. Among the 18 cases with a cytologic diagnosis of atypia, there was a strong positive relationship between TRAP findings and histologic diagnosis. CONCLUSION: The detection of TA in FNAs of breast lesions is a highly sensitive and specific marker of malignancy and may be used as an adjunct in cases with an equivocal cytologic diagnosis.

Frequent hypermethylation of the 5' CpG island of E-cadherin in esophageal adenocarcinoma.

PURPOSE: E-cadherin, a M(r) 120,000 transmembrane glycoprotein, mediates calcium-dependent intercellular adhesion that is essential for normal tissue homeostasis. Loss of E-cadherin occurs in a variety of epithelial tumors and is correlated with invasion and metastasis. In esophageal adenocarcinoma, reduction of E-cadherin expression has been demonstrated previously, but mutations of the gene (CDH1) are rare. EXPERIMENTAL DESIGN: In this study, we used a nested PCR approach to examine the methylation status of the 5' CpG island of E-cadherin in esophageal specimens obtained from individuals with and without a history of esophageal cancer. RESULTS: In four individuals without esophageal cancer, E-cadherin was completely unmethylated in normal squamous cell-lined esophageal mucosa. In contrast, in patients with esophageal adenocarcinoma, E-cadherin was methylated in 26 of 31 (84%) tumor specimens. In the majority of cases, matched normal tissue (esophagus or stomach) from each patient was completely unmethylated. By immunostaining, methylated tumor samples demonstrated heterogeneously decreased membranous E-cadherin staining. CONCLUSIONS: These data suggest that epigenetic silencing via aberrant methylation of the E-cadherin promoter is a common cause of inactivation of this gene in esophageal adenocarcinoma.

Genetic alterations in chronic ulcerative colitis-associated adenoma-like DALMs are similar to non-colitic sporadic adenomas.

Recent molecular studies have shown that there are differences in the prevalence and timing of certain molecular events between chronic ulcerative colitis (CUC)-associated dysplastic lesions and non-CUC-related sporadic adenomas. However, little is known regarding the molecular features of a specific subtype of CUC-related dysplasia-associated lesion or mass (DALM) that clinically, endoscopically, and pathologically resemble sporadic adenomas, and whether these lesions can be separated from non-CUC-related sporadic adenomas on the basis of their molecular genotype. Therefore, the purpose of this study was to evaluate loss of heterozygosity (LOH) of 3p, APC, and p16 in a specific group of CUC-associated "adenoma-like" DALMs and to compare the results of this tumor with those in a well-defined group of CUC-associated non-adenoma-like DALMs and non-CUC-associated sporadic adenomas. Polypectomy or resection specimens from 21 CUC patients with an adenoma-like DALM, 8 CUC patients with at least one nonadenoma-like DALM (12 lesions in total), and 23 non-CUC patients with a sporadic adenoma were evaluated for LOH of 3p, APC, and p16 by PCR analysis. The results were compared among the three different study groups and correlated with the clinical features of the patients and the pathology of their tumors. Chronic ulcerative colitis-associated adenoma-like DALMs showed LOH of 3p in five of 18 (28%) cases. This value was not significantly different from the 5% of non-CUC sporadic adenomas (p = 0.14) that were positive. However, 50% of CUC-associated non-adenoma-like DALMs were positive for LOH of 3p, and this value was significantly higher (p = 0.01) than the other groups. The frequency of LOH of APC did not differ significantly between the three patient groups (33%, 33%, and 43% in the three groups, respectively). Similar to the 3p results, CUC-associated adenoma-like DALMs and non-CUC-associated sporadic adenomas showed a similar low frequency of positivity for LOH of p16 (5% and 4%, respectively) in comparison to 56% of CUC-associated non-adenoma-like DALMs (p = 0.003). For all markers, no significant differences were detected in the CUC-associated adenoma-like DALM group between lesions that occurred within colitis compared with those that occurred in areas not involved by colitis. Chronic ulcerative colitis-associated non-adenoma-like DALMs have a different molecular genotype than CUC-related adenoma-like DALMs and non-CUC sporadic adenomas. Our data also suggests that the latter two groups of neoplasms may in fact represent a similar, if not identical, pathogenetic entity.

Cell-cycle kinetics of permanent glioma-cells measured by pulse labeling with bromodeoxyuridine.

Cell phase distribution and cycle kinetics of six human glioblastoma cell lines were characterized after labelling with 5-Bromo-2-deoxyuridine (BrdUrd). Cycle time (T(c)), DNA synthesis time (T(s)), and potential doubling time (T(pot)) were compared with the actual doubling time (T(d)) of the growing cell population. Mathematical estimates closely correlated with T(d). Low labelling index (LI) correlated with short T(s) and vice versa. T(s) and LI allowed grouping of the cell lines in two clusters. The mean number of silver stained nucleolar organizer regions (mAgNORs) and percentage of cells with more than five AgNORs (pAgNOR) were counted. AgNORs closely related to LI. Low mAgNORs and pAgNORs correlated with fast T(s) among the clustered cell lines.

Mutations of the STK11 gene in sporadic gastric carcinoma.

Gastric carcinoma may occur sporadically or in association with hereditary diseases, such as Peutz-Jehgers syndrome (PJS). The PJS gene (named STK11 or LKB1) was mapped to 19p13.3 and recently cloned. Germ-line mutations of the gene have been detected in familial PJS patients and are predicted to predispose STK11 carriers to the development of a wide range of gastrointestinal and other neoplasms. To elucidate the etiological role of the STK11 gene in sporadic gastric carcinoma tumorigenesis, we analyzed 28 gastric carcinomas (22 of intestinal type and 6 of diffuse type) for STK11 gene mutations. STK11 gene mutations were detected in 3 of 28 gastric carcinomas but were not seen in the corresponding germ-line DNA sequence. In one tumor, a missense mutation, C-to-T transition, was detected at codon 324 resulting in proline to leucine substitution; in the other two, silent mutations were detected at codons 106 and 350, respectively. While these results suggest that somatic STK11 mutations are not common in sporadic gastric carcinomas, they may occur in a subset of these tumors.

Utilization of molecular genetics in the differentiation between adrenal cortical adenomas and carcinomas.

Distinction between benign adrenal cortical proliferative lesions and adrenal cortical carcinoma has been approached by a combination of histological, immunohistochemical, and macroscopical parameters. Modern imaging studies allow detection of small adrenal cortical lesions that may be incorrectly diagnosed. Differentiation between benign and malignant tumors of the adrenal cortex was attempted by microdissection of nine cases of adrenal cortical hyperplasia, 10 cortical adenomas, and 18 adrenal cortical carcinomas with subsequent polymerase chain reaction (PCR) amplification for loss of heterozygosity (LOH) of five microsatellites of putative tumor suppressor gene loci: p53 gene (17p), the neuroblastoma candidate gene (1p), the p16 gene (9p), the von Hippel Lindau gene (3p), and the retinoblastoma gene (13q). None of the hyperplastic lesions or cortical adenomas showed LOH of any of the gene markers used. Conversely, genetic changes were observed in 61% (11 of 18) of the cases of carcinoma. Forty-four percent of the lesions showed LOH for p53 (7 of 16). LOH of 1p, 3p, and 9p were seen in 22%, 22%, and 26%, respectively. LOH of the retinoblastoma gene was seen in 80% or four of five of the informative cases studied. We conclude that LOH studies may be used to distinguish malignant from nonmalignant adrenal cortical proliferations. Relative infrequency of LOH in 3p may furthermore help to differentiate adrenal lesions from clear cell carcinomas of the kidney.

Comparison of genetic alterations in colonic adenoma and ulcerative colitis-associated dysplasia and carcinoma.

Carcinoma is an important complication of ulcerative colitis (UC) and develops from dysplastic precursor lesions. Genetic changes involved in the malignant transformation have not been fully characterized. We studied 19 cases of UC with high-grade dysplasia (HGD) and eight samples of associated carcinoma (CA). Microdissection of normal epithelium, epithelium at the site of chronic inflammation, HGD, and CA was performed. Polymerase chain reaction (PCR) amplification for loss of heterozygosity (LOH) of the following polymorphic microsatellites of putative tumor suppressor gene loci was done: APC (5q), DCC (18q), p16 (9p), p53 (17p), and 8p12. To compare genetic alterations, 22 typical adenomas of the colon were studied with the markers for APC and pl6 gene loci. The results indicated that LOH of p16 and p53 were present in nondysplastic epithelium, HGD, and CA. However, the LOH in nondysplastic epithelium was detected in some associated HGD, but not all. Whereas LOH of p16 was present in 7 of 14 cases of HGD (50%), it was noted in only 1 of 22 adenomas (5.0%). LOH in the APC and DCC gene loci in UC was noted in HGD with associated CA, but LOH of APC was not present either in cases of nondysplastic epithelium or in HGD alone. Conversely, LOH in APC was present in 4 of 19 colonic adenomas. We conclude that LOH of p53 and p16 in nondysplastic epithelium may be associated with chronic reparative processes. These changes may lead to susceptibility to further genetic damage involving the APC and DCC gene loci in the development of dysplasia and progression of CA in UC. The low frequency of LOH in the p16 gene (9p) in adenomas compared with dysplasia in UC combined with infrequent LOH in APC gene loci in cases of pure dysplasia in UC may support this combination of markers as a clinical test for the differentiation of polypoid dysplasia from adenomas in UC.

A germline hMSH2 alteration is unrelated to colonic microsatellite instability in patients with ulcerative colitis.

Recently, a polymorphism in the hMSH2 DNA mismatch repair gene has been associated with the development of dysplasia in ulcerative colitis (UC) patients. This polymorphism is of interest because DNA mismatch repair defects result in alterations in microsatellite stability. The current study was designed to determine whether this hMSH2 polymorphism associates with the development of microsatellite instability and dysplasia in UC patients. The hMSH2 genotype of 96 UC patients was determined by direct DNA sequencing. In addition, we examined 363 samples of colonic mucosa from 93 of these UC patients for microsatellite mutation by polymerase chain reaction (PCR) at eight loci. Three cases had insufficient DNA for microsatellite instability studies. The hMSH2 polymorphism was identified in 13 of the 96 patients examined (13.5%). The polymorphism was observed in 7 of 46 patients with dysplasia (15.2%), and in 6 of 50 patients without dysplasia (12.0%). Microsatellite instability was identified in 35 tissue samples (25 regenerative, one indefinite for dysplasia, eight dysplasias, and one invasive carcinoma) from 26 patients. Two patients with microsatellite instability had the hMSH2 alteration. The 11 remaining patients had the hMSH2 polymorphism, but no evidence of microsatellite mutations with any of the markers tested. We were unable to confirm the previously reported findings that the specific germline hMSH2 alteration represents a marker for increased risk of dysplasia in patients with UC, nor is it responsible for the development of microsatellite instability in these patients.

Loss of heterozygosity of the von Hippel Lindau gene locus in polypoid dysplasia but not flat dysplasia in ulcerative colitis or sporadic adenomas.

Carcinoma in ulcerative colitis (UC) develops from dysplastic precursor lesions, which include flat dysplasia (FD) and polypoid dysplasias (PD). PD may present as single or multiple polypoid structures or as plaque-like lesions that, independent of histological grade, are an indication for colectomy. PDs are histologically similar to adenomas and may not be readily distinguished by light microscopy. It is not known whether FD and PD are different entities, or whether they represent etiologically similar lesions with different morphological expression. We microdissected 25 cases of UC with PD and 19 samples of FD with surrounding chronic colitis (CC) in UC. Loss of heterozygosity (LOH) at the von Hippel Lindau (vHL) gene locus and the putative tumor suppressor genes APC, INK4A (9p16), and p53 was studied. LOH of the vHL gene, INK4A (9p16), and APC was also studied in 11 sporadic adenomas of the colon. LOH at the vHL locus was present in 50% of the samples of PD and in 12% of the samples of FD. LOH was seen in CC close to PD and FD in 26% and 12% of cases, respectively. No adenoma showed LOH of the vHL gene markers studied. LOH in p53 was seen in PD in 16% cases and in FD in 42% cases and in CC close to PD and FD in 0% and 14% cases, respectively. LOH patterns between PD and FD of the markers for APC and 9p16 were not different. LOH in APC was seen in two of five cases of adenoma. We conclude that PD and FD share genetic alterations in APC and 9p16 genes. More frequent involvement of the VHL gene in PD and surrounding CC and involvement of p53 in HGD and CC in FD may represent genetic differences between the development of PD and FD and may be the cause of the different morphology. The infrequency of LOH at the vHL locus in adenomas versus PD may serve as a discriminator between adenomas and PD in diagnostically problematic cases.

Distinction between dysplasia-associated lesion or mass (DALM) and adenoma in patients with ulcerative colitis.

Polyps with epithelial dysplasia in ulcerative colitis (UC) represent either dysplasia-associated lesions or masses (DALMs) or sporadic adenomas. DALMs are frequently associated with associated carcinoma and are an indication for colectomy. Removal of the polyp is treatment of choice for sporadic adenomas. Differentiating between these 2 lesions is not always easy. The goal of this study was to distinguish DALMs from adenomas in patients with UC on a genetic basis. We evaluated genetic alterations in DALMs and compared them with a previously published set of dysplastic polyps in patients with UC that were considered adenomas for the following reasons: (1) polyps were located outside of current active disease; (2) polyps had histological features of sporadic adenomas; and (3) patients displayed a uneventful follow-up after polypectomy (UC-adenomas). In addition, adenomas not associated with UC were studied. Genetic alterations on chromosome 3p were assessed for the markers D3S1766, D3S2409, and D3S2387. LOH with or without microsatellite instability was found in 70%, 37%, and 57% of cases of DALM, respectively. In contrast, UC-adenomas lesions exhibited genetic alterations in 8.3%, 11.7%, and 15.3% for the respective markers. Spontaneous adenomas exhibited genetic alterations in 10.5%, 7.1%, and 0% of cases, which were not significantly different from the UC-adenoma results. These results indicate that UC-adenomas are genetically and biologically similar to sporadic adenomas and that UC-adenomas may biologically represent sporadic adenomas, supporting on a genetic basis the criteria chosen to diagnose adenomas in UC. Genetic markers on chromosome 3p may be useful in the differential diagnosis between DALM and UC-adenomas.

A prospective analysis of the frequency, location, and curability of ectopic (nonpancreaticoduodenal, nonnodal) gastrinoma.

BACKGROUND: Extrapancreatic, extraduodenal and extralymphatic (ectopic) gastrinomas have been reported only rarely. The frequency, locations, and surgical outcome of these lesions are unknown. METHODS: From 1982 to 1997, 215 patients with Zollinger-Ellison syndrome were evaluated prospectively at the National Institutes of Health and 142 patients (66%) underwent standardized surgical exploration and resection. Eight patients (5.6%) (six men and two women; mean age, 41 years) had primary gastrinoma located in ectopic sites. Long-term follow-up was derived from a prospective database. RESULTS: Ectopic gastrinoma tissue was identified and resected in the liver (three patients), common bile duct (one patient), jejunum (one patient), omentum (one patient), pylorus (one patient), and ovary (one patient). Seven patients (88%) were cured biochemically after resection and five patients (63%) have sustained cures, with a mean follow-up of 7.5 years (range, 0.4 to 11.7 years). One patient with a jejunal primary gastrinoma had a biochemical recurrence at 2 years, and another with a primary hepatic gastrinoma had a recurrence 6 years after resection. A patient with a pyloric primary gastrinoma was not cured. CONCLUSIONS: Extraduodenal, extrapancreatic, and extranodal gastrinomas are encountered in 5.6% of patients who undergo exploration with curative intent. If no gastrinoma is found in the usual locations, other ectopic sites should be examined carefully. Resection of these primary ectopic tumors can lead to durable biochemical cures.

Expression of survivin, YB-1, and KI-67 in sporadic adenomas and dysplasia-associated lesions or masses in ulcerative colitis.

Sporadic adenomas are said to exhibit an orderly growth pattern with a reversal of proliferative and apoptotic cell distribution as compared with normal colonic crypts. Dysplastic polyps of patients with ulcerative colitis (UC) may represent dysplasia-associated lesions or masses (DALM) with a high associated cancer risk, or, alternatively, may represent sporadic adenomas. Histologic criteria to differentiate between sporadic adenomas and DALM have not focused on the balance between cell renewal and cell loss. The expression of the novel anti-apoptosis gene product, survivin, and the proliferation markers, Ki-67 and Y-box binding protein (YB-1), were investigated by immunohistochemical localization in sporadic adenomas and DALM lesions of patients with UC. In adenomas, KI-67 was expressed preponderantly at the luminal aspect of the polyp, whereas its expression was diffuse in DALM. Survivin was detected diffusely in both adenomas and DALM. YB-1 showed positive staining in the deep aspect of adenomatous glands but only to a minor degree at the surface, whereas both deep and diffuse expression patterns of YB-1 were seen in DALM. The authors conclude that DALM and sporadic adenomas exhibit different patterns of cellular proliferation and that molecular markers of cell proliferation, Ki-67 and YB-1, may be useful to distinguish sporadic adenomas from DALM. However, the similar expression of survivin suggests that the underlying mechanisms that regulate apoptotic cell death are uniform in these lesions.

Polypoid dysplasias in ulcerative colitis and sporadic adenomas: genetic approach to the differential diagnosis (review).

Development of carcinoma in cases of ulcerative colitis is initiated out of regions of dysplasia. Dysplasia may present as single or multiple flat lesions, or as polypoid dysplasia (DALM-lesion). Dysplasia in DALM lesions may not be readily differentiated from that of sporadic adenomas by light microscopy. Such distinction, however, dictates therapeutic strategies. Since colectomy is treatment of choice in DALM lesions but removal of a sporadic adenoma is sufficient therapy, several attempts have been made to find markers to differentiate the two lesions. In recent years molecular genetic studies have demonstrated different genetic alterations in the dysplasia-carcinoma event in ulcerative colitis versus sporadic colorectal carcinoma, which may in fact help to differentiate the two entities. The diagnostic tools to differentiate DALM from sporadic adenomas are briefly described and a specific emphasis is given to the molecular genetic studies which may help in defining the specific entities.

Evaluation of the c-Met immunostain to detect malignant cells in body cavity effusions.

The cytologic diagnosis of malignant cells in serous effusions can be difficult. A wide variety of immunostains and other diagnostic techniques have been studied but without widespread acceptance of one staining panel or technique. Expression of the tyrosine kinase c-Met has been associated with several malignancies but not with benign mesothelium. We investigated the diagnostic value of the c-Met immunostain in serous effusions. Cell block material from 76 cases of unequivocally benign or malignant effusions were studied. Cases were stained with c-Met using the avidin-biotin complex method following antigen retrieval. The presence of strong granular cytoplasmic staining that was distinct from background staining was considered positive. Positive cells were identified in 38 of 42 (90%) malignant cases and in 18 of 34 (53%) benign cases. Typically, benign cases contained only individual positive cells, but positive cell clusters were also identified. The c-Met immunostain lacks sufficient specificity to be clinically useful in this cytologic setting. The expression of c-Met in benign mesothelium may reflect mesothelial proliferation.

Collecting duct carcinomas of the kidney: a comparative loss of heterozygosity study with clear cell renal cell carcinoma.

Origin of collecting duct carcinomas (CDC) of the kidney is not entirely known, although it is thought that they originate from the distal collecting duct system, whereas clear cell renal cell carcinoma (cRCC) may originate from the proximal tubular epithelium. In cRCC, the von Hippel Lindau gene (vHL) is damaged in almost 100% of cases; the frequency of vHL deletions in CDC is not known. Loss of heterozygosity (LOH) of CDC and cRCC of vHL (3p), p16 (9p), p53 (17p) and the retinoblastoma (RB) gene (13q) was studied to evaluate possible genetic differences between the two. LOH of the vHL was seen in 77.7% of cRCC and in 55% of CDC. P16 was lost in 33% of cRCC and in 50% of CDC. LOH in p53 was observed in 0/8 cases of cRCC compared to 18.7% in CDC. LOH in 13q was seen in 25% of both CDC and cRCC. The high LOH rate of the vHL gene in CDC has not been observed previously. The findings indicate that CDC and cRCC share certain genetic alterations, including frequent deletion of the vHL gene. CDC is not clearly related to cRCC but may be of heterogeneous origin.

Comparison of p53 immunoexpression with allelic loss of p53 in ulcerative colitis-associated dysplasia and carcinoma.

We correlated p53 overexpression with allelic deletion of p53 in ulcerative colitis (UC) with high grade dysplasia (HGD, n=12) and carcinoma (CA, n=8). Sections were immunostained against p53 and epithelium was microdissected on consecutive sections with subsequent amplification for LOH of p53 (17p). Staining with anti-p53 was positive in HGD (9 of 12) and CA (7 of 8). Percent positive cells were less in HGD than in CA. LOH of p53 was present in HGD (5 of 12) and CA (5 of 7). Of cases with <10% of positive cells, including negative cases, 50% also showed LOH. These results suggest that most cases with prominent p53 overexpression but also significant numbers of cases with weak or negative expression have associated allelic p53 deletion. We conclude that i) immunohistochemical stains but not LOH for p53 correlate with progression of dysplasia to carcinoma, ii) p53 immunohistochemistry appears to more accurately predict biologic behavior of dysplasia and carcinoma in UC compared to allelic deletion studies alone. Further microdissection studies are necessary to evaluate the possibility of different carcinoma risk in patients with low percentage of p53 overexpression and associated LOH.

Identification of lymphatic vessels in malignant, adenomatous and normal colonic mucosa using the novel immunostain D2-40.

Distribution of lymphatic vessels in normal and neoplastic colon has been previously analyzed with electron microscopic techniques, as reliable antibodies have not been available for selective lymph vessel staining. A novel monoclonal antibody, D2-40, is recently available to differentiate lymphatic vessels from blood vessels. In this study, we analyzed the distribution of lymphatic vessels in normal colon, adenomas with and without superficial stalk invasion and invasive carcinomas without identifiable polypoid precursor lesions. In contrast to previous studies, we found lymphatic vessels in superficially misplaced stalk stroma in adenomas, and closely associated with early invasive epithelial nests in invasive lesions. Lymphatic vessels were identified within the lamina propria of the in situ aspect of in invasive tumors. We conclude that lymphatic vessel structures are seen more superficially in adenomas and invasive carcinomas than previously described. Since intramucosal carcinomas in adenomas do not metastasize, these lymph vessels may be immature or not communicate with deeper lymphatics. Proliferation and distribution of lymphatic vessels may be related to prognosis and early metastasis.

Ultra fast identification of Aspergillus species in pulmonary cytology specimens by in situ hybridization.

The cytologic diagnosis of pulmonary aspergillosis infection is typically made on a presumptive basis and later confirmed by fungal culture, which may take up to one week to complete. An in situ hybridization (ISH) probe specific for Aspergillus for use in surgical pathology specimens has been developed which has not been used on cytology preparations. We describe a supra-threshold adapted testing (STAT) in situ hybridization test for cytology specimens, which takes less than one hour to finish. We performed ISH on three cases of culture-proven pulmonary aspergillosis and one case with Aspergillus fungal forms but negative cultures to test the feasibility of using this same Aspergillus probe on cytology specimens. Four patients with pulmonary aspergillosis were initially diagnosed by cytologic examination of their respective specimens. The presumptive diagnosis was confirmed by culture to be Aspergillus fumigatus on three cases. ISH on both cytology cytospin and Thin-Prep specimens was performed using an rRNA Aspergillus specific probe. All four cytology specimens exhibited positive staining with the Aspergillus probe. Most, but not all, fungal hyphae were stained with the probe. Even though ISH is more expensive than culture, in situ hybridization can be performed in less than one hour on cytology specimens and may be beneficial for patients in selected clinical circumstances.

A fast non-fluorescent staining method for the detection of primed in situ synthesis products.

For the assessment of chromosomal numeral aberrations in cells, the method of choice is fluorescent in situ hybridisation (FISH) or, a newly introduced technique, oligonucleotide primed in situ hybridisation (PRINS). In the PRINS method labeled nucleotides are incorporated into newly synthesized DNA mediated through the Taq polymerase. Both PRINS and FISH reactions are visualized with a fluorescent light detection system. We present a method whereby PRINS products can be reliably and rapidly visualized by a streptavidin DAB detection system.