Neurofilament heavy chain-like messenger RNA and protein are present in benign prostate and down-regulated in prostatic carcinoma.

Differences in gene expression between benign and malignant human prostate specimens were investigated using the differential display technique. RNA samples from paired benign and malignant areas microdissected from opposite sides of the same prostate gland were used for reverse transcription PCR. A 477-bp band was identified that was consistently present in benign prostate but absent or diminished in intensity in malignant tissue. This band was cloned, and the sequence demonstrated 99% identity with a region in the fourth exon of the human neurofilament heavy chain gene (NF-H). Northern blotting with a cDNA probe derived from this band confirmed the presence of a similarly sized message of approximately 3.9 kb in both prostate and brain, and reverse transcription PCR using primers specific to an upstream region of exon 4 confirmed NF-H-like mRNA expression in benign prostatic tissue. Immunostaining with a monoclonal antibody to NF-H showed a positive reaction in benign prostatic epithelial cells but complete absence of staining in prostatic cancer cells. These data demonstrate the presence of a NF-H-like gene product in normal prostatic epithelial cells that is down-regulated or absent in prostatic carcinomas.

Reliability of differential PCR for the detection of EGFR and MDM2 gene amplification in DNA extracted from FFPE glioma tissue.

A series of 43 human gliomas, consisting of 30 glioblastomas, 7 anaplastic astrocytomas, 3 low grade astrocytomas, 2 ependymomas, and 1 oligodendroglioma, was studied for amplification of the epidermal growth factor receptor (EGFR) and mouse double minute 2 (MDM2) genes. DNA extracted from formalin-fixed, paraffin-embedded tissue sections was analyzed by differential PCR and the results were compared with slot blot examination of DNA extracted from frozen tissue from the same neoplasms. Twelve glioblastomas (40%) showed amplification of the EGFR gene, and overexpression of EGFR was evident in each of these tumors as indicated by the immunoperoxidase technique. Two of the tumors with EGFR gene amplification also revealed amplification of the MDM2 gene, while one additional glioblastoma revealed MDM2 amplification only. A 100% concordance in the detection of amplification was observed between differential PCR and slot blot analysis; consequently, these results indicate that differential PCR using DNA extracted from archival tissue sections is a reliable method of demonstrating gene amplifications in glial tumors.

Auditory brain-stem potentials with unilateral pontine hemorrhage.

Although there have been extensive anatomical and physiological studies in animals, the actual neural sources, or even the laterality, of some components of auditory brain-stem evoked potentials in humans are uncertain. We studied these responses in a 56-year-old patient who had a clearly demarcated pontine hemorrhage on the right side. The patient was somnolent, with dense left hemiplegia and signs of involvement of right cranial nerves V, VI, and VII. Stimulation of the left ear (ie, contralateral to the lesion) evoked a normal series of waves with clearly resolved positive components peaking at 2.0, 3.3, 4.8 (wave IV), and 6.0 ms (wave V). Stimulation of the right ear (ie, ipsilateral to the lesion) evoked only waves I, III, and IV. These results suggest that a pathway ipsilateral to the stimulated ear is necessary and sufficient for generation of auditory wave V and that wave IV is generated in bilateral pathways.

Two-site monoclonal antibody quantitative ELISA for toxic shock syndrome toxin-1.

A two-site monoclonal antibody (MAB) quantitative enzyme-linked immunosorbent assay (ELISA) was developed that enables quantitation of toxic shock syndrome toxin-1 (TSST-1) down to 0.25 ng/ml and detection of TSST-1 to 0.06 ng/ml. Interference by Staphylococcus protein A was eliminated by incorporating normal rabbit serum into the test sample diluent. In the process of selecting an MAB pair for a two-site 'sandwich'-type ELISA, the MABs were screened for inhibition or common epitope binding. Some MABs that reacted with antigen that was adsorbed to a polystyrene well would not bind to antigen that was presented in a more natural configuration, as in the case of antigen immobilized by trapping antibody. Conversely, MABs that reacted with antigen that was immobilized by another antibody did not all function as trapping antibodies when adsorbed directly to a polystyrene surface. ELISAs that used polyclonal antibodies in the capture mode and MAB conjugate as the second antibody were generally more sensitive than were those that used polyclonal antibodies for both capture and indicator functions. MAB screening and selection schemes should be carefully designed to evaluate MABs in the mode in which they will be used in the final assay.

Non-isotopic in situ hybridization method for mitochondria in oncocytes.

We used in situ hybridization to specifically identify mitochondria in a series of formalin-fixed, paraffin-embedded oncocytic lesions. Digoxigenin-labeled DNA probes were generated by the polymerase chain reaction (PCR), with primers designed to amplify a mitochondrion-specific 154 BP sequence within the ND4 coding region. Probes were hybridized with mitochondrial DNA under stringent conditions. Oncocytes were strongly and consistently stained, reflecting the high copy number of mitochondrial DNA within these cells. Because of the presence of endogenous biotin within mitochondria, digoxigenin is preferable to biotin as a label for detection of mitochondria.

Analysis of cyclin dependent kinase inhibitors in malignant astrocytomas.

The cyclin-dependent kinase inhibitors p16, p21, and p27 in human brain, and brain tumors were examined to explore clinicopathologic correlations. Western analysis and immunohistochemistry was performed and correlated retrospectively with the patients clinical characteristics. A trend was found between increased progression-free survival and p27 expression. There was no correlation between p27 expression and age or gender. The expression of p27 in malignant gliomas may have prognostic value. In addition, an investigation of the therapeutic benefit of overexpression of this cyclin-dependent kinase inhibitor is warranted given reports of diminished malignant potential of tumors expressing p27.

Tumor suppressor gene alterations in malignant gliomas: histopathological associations and prognostic evaluation.

We have examined a series of 135 gliomas for alterations of the p53, CDKN2A (p16) and PTEN tumor suppressor genes (TSGs) in order to evaluate the incidence of their inactivation as a function of tumor malignancy and cellular differentiation, and to examine potential associations with patient outcome. The composition of this series, classified using WHO criteria, is as follows: 27 grade 2 tumors (11 astrocytomas, 12 oligoastrocytomas, 4 oligodendrogliomas), 42 grade 3 tumors (22 astrocytomas, 16 oligoastrocytomas, 4 oligodendrogliomas), and 66 grade 4 tumors (63 astrocytomas and 3 oligoastrocytomas). Similar frequencies of p53 mutation were observed among grade 2 (37.0%), and grade 3 tumors (38.1%), as well as between astrocytomas and mixed tumors. CDKN2A and PTEN mutations were clearly associated with increasing tumor malignancy (occurring in 0% of grade 2 tumors, 14.3% and 4.8% respectively of grade 3 tumors, and 27.3% and 30.3% respectively of grade 4 tumors) and were observed at substantially higher rates among astrocytomas. For the tumor suppressor genes examined, there was no relationship between the occurrence of any two TSG inactivation events. With regard to outcome, the p53 genetic status showed no significant relationship with patient survival. The CDKN2 and PTEN alterations were negative prognostic indicators of survival when evaluated in all 135 gliomas, but failed to predict outcome when evaluated in either of the high grade (3 or 4) tumor groups.

Potential risks in retrovenous revascularization of the myocardium.

Retrovenous perfusion of the myocardium via the coronary sinus and cardiac veins was one of the earliest attempted forms of myocardial revascularization. Although coronary artery revascularization has almost completely replaced venous revascularization as the procedure of choice, the latter approach is still occasionally performed. We present two cases of hemorrhage within viable and nonviable myocardium noted at autopsy in patients who had undergone retrovenous revascularization hours before death. The two cases illustrate a complication of this procedure that has not previously been emphasized.

Extraadrenal myelolipoma. A report of two cases.

Two cases of extraadrenal myelolipoma with unusual clinicopathologic features are described. The patient in case 1 had multifocal myelolipomas, involving both the lung and retroperitoneum, that mimicked malignancy, and the patient in case 2 had a single diffuse retroperitoneal myelolipoma without circumscription. Of possible etiologic significance is the fact that both patients were treated with exogenous steroids.

Metastatic follicular thyroid carcinoma masquerading as a chordoma.

A 61-year-old Caucasian man presented with otalgia, dysarthria, and weight loss. Neurological examination revealed palatal hypomotility, and weakness of the facial and tongue muscles. Magnetic resonance imaging of the head demonstrated the presence of a soft tissue mass in the clivus. Histologic examination of resected tumor disclosed well-differentiated thyroid follicles that invaded the local osseous tissues. Physical examination and radioiodine images of the thyroid gland were normal. The serum thyroglobulin concentration was markedly elevated (1011 ng/mL). A 0.9-cm well-differentiated benign-appearing left thyroid lobe follicular neoplasm with a thick fibrous capsule was found following diagnostic thyroidectomy. This report illustrates that clinically significant distant metastases can arise from occult follicular thyroid neoplasms that, according to standard histologic criteria, are benign. The presence of a thick fibrous capsule, even in the absence of vascular or capsular invasion, may identify follicular neoplasms that have metastatic potential.

Social "facilitation" as challenge and threat.

The authors conducted an experiment to test a theoretical explanation of social facilitation based on the biopsychosocial model of challenge and threat. Participants mastered 1 of 2 tasks and subsequently performed either the mastered (i.e., well-learned) or the unlearned task either alone or with an audience while cardiovascular responses were recorded. Cardiovascular responses of participants performing a well-learned task in the presence of others fit the challenge pattern (i.e., increased cardiac response and decreased vascular resistance), whereas cardiovascular responses of participants performing an unlearned task in the presence of others fit the threat pattern (i.e., increased cardiac response and increased vascular resistance), confirming the authors' hypotheses and the applicability of the biopsychosocial model of challenge and threat to explain these results.

Perceiver threat in social interactions with stigmatized others.

The extent to which stigmatized interaction partners engender perceivers' threat reactions (i.e., stigma-threat hypothesis) was examined. Experiments 1 and 2 included the manipulation of stigma using facial birthmarks. Experiment 3 included manipulations of race and socioeconomic status. Threat responses were measured physiologically, behaviorally, and subjectively. Perceivers interacting with stigmatized partners exhibited cardiovascular reactivity consistent with threat and poorer performance compared with participants interacting with nonstigmatized partners, who exhibited challenge reactivity. In Experiment 3, intergroup contact moderated physiological reactivity such that participants who reported more contact with Black persons exhibited less physiological threat when interacting with them. These results support the stigma-threat hypothesis and suggest the utility of a biopsychosocial approach to the study of stigma and related constructs.

WHO-sponsored international collaborative study to evaluate methods for subtyping Listeria monocytogenes: restriction fragment length polymorphism (RFLP) analysis using ribotyping and Southern hybridization with two probes derived from L. monocytogenes chromosome.

Seven laboratories participated in a WHO-sponsored international collaborative study, to evaluate methods for subtyping Listeria monocytogenes, by performing restriction fragment length polymorph sm (RFLP) analysis-based subtyping of an international study set of 80 strains of L. monocytogenes that included 22 epidemiologically related groups. The RFLP analysis was done by Southern hybridization with one of two types of probes found in multiple copies on the chromosome of L. monocytogenes. Six laboratories performed ribotyping. These laboratories used EcoRI enzyme to restrict the L. monocytogenes DNA and ribosomal RNA or DNA as the probe for Southern hybridizations. The seventh laboratory used Ncil to restrict the DNA, and two probes, one randomly cloned and the other containing repeat sequences cloned from L. monocytogenes DNA. The overall discriminating power of ribotyping, as estimated by calculation of Simpson's index of diversity, ranged from 0.83 to 0.88 for the six laboratories. The discriminating power of the combination of two probes used by Laboratory 7 was 0.91. Ribotyping and the cloned probes used by Laboratory 7 discriminated poorly between serotype 4b strains. Neither method identified three atypical strains (identified by other subtyping methods) included in three apparently epidemiologically related groups. Ribotyping did not discriminate between strains of serotypes 4b and 4b(X) in one epidemiologically related group of strains; one cloned probe used by Laboratory 7 discriminated between these strains. Intra-laboratory reproducibilities for the seven laboratories ranged from 80.0 to 100%. as determined by their abilities to correctly identify 11 pairs of duplicate strains included in the study set. Inter-laboratory reproducibilities were generally very good considering that no attempt was made to standardize protocols used by the participants.

Focal polypoid ischemia of the colon: atheroemboli presenting as a colonic polyp.

Cholesterol emboli are known to imitate a variety of disease processes, thereby leading to delayed diagnosis. We describe a patient with a localized polypoid mass of the colon without endoscopic evidence of generalized ischemic colitis. Histologic evaluation revealed this polyp to be the result of localized ischemia with identifiable submucosal atheroemboli. Localized polyp formation appears to be a rare manifestation of atheroemboli; consequently, focal ischemia, caused by atheroemboli, should be added to the differential diagnosis of polyps of the colon.

Multiple sclerosis mimicking primary brain tumor.

Surgical biopsy specimens of multiple sclerosis plaques have been only infrequently reported, and the scanty descriptions of these specimens have generally emphasized the inflammatory nature of the lesion. We present surgical specimens from four patients with multiple sclerosis on whom biopsies were performed because of clinical features mimicking brain tumor. Both general pathologists and neuropathologists involved with these cases experienced difficulty in arriving at the correct diagnosis. In all four cases, the lesions were remarkably uniform in microscopic appearance, consisting of monotonous sheets of gemistocytic astroglia interspersed by numerous foamy macrophages. In sections stained with hematoxylin-eosin, the most helpful diagnostic features were the even distribution of the foamy macrophages and the absence of associated necrosis. In each case, the diagnosis was confirmed with special stains that disclosed total destruction of myelin sheaths with relative preservation of axons. Significant inflammatory infiltration was present in only one of five biopsy specimens.

Extramammary Paget's disease. Arising in knee region in association with sweat gland carcinoma.

We report a case of extramammary Paget's disease (EMPD) arising in the knee region in association with an underlying sweat gland carcinoma. Inguinal lymph node metastases were present initially. Paget's cells, intradermal tumor cells, and metastatic tumor cells showed similar reactions to a variety of histochemical stains and positive results with immunohistochemical staining using carcinoembryonic antigen (CEA). Control sections in cases of Bowen's disease and superficial, spreading malignant melanoma showed a negative staining reaction with CEA, providing further evidence that this technique is useful in distinguishing Paget's disease (PD) from histologically similar conditions. We provide a summary of previous cases of EMPD arising in unusual locations and a brief consideration of possible mechanisms of the origin of PD.

Intrasellar pituicytoma in a patient with other endocrine neoplasms.

Considered a neoplasm of pituicytes, pituicytoma is a rare and distinct type of glioma that arises in the suprasellar space and within the sella turcica. Only 12 previously reported cases of pituicytoma are documented in the literature. We report an intrasellar pituicytoma in a 66-year-old man presenting with symptoms and radiologic appearance indistinguishable from a nonfunctional pituitary adenoma. The patient also had a medical history significant for parathyroid adenomas and follicular carcinoma of the thyroid. The intrasellar tumor had morphologic features of a pituicytoma, with interlacing fascicles and a storiform pattern much like a benign fibrous histiocytoma. Immunoreactivity for S100 was strong, but the tumor lacked intercellular collagen type IV. The differential diagnosis of a low-grade spindle cell lesion of the sellar space is discussed, and the literature is reviewed. A summary of the clinical and pathologic features of this case, as well as the 12 previously reported cases, is presented.

Low-grade astrocytomas arising from the pineal gland.

Two cases of low-grade astrocytoma arising from the pineal gland are described in this report. These rare lesions have only been reported on two previous occasions to arise distinctly from the pineal gland. Histologically, one tumor was consistent with a juvenile pilocytic astrocytoma, while the other was consistent with a fibrillary astrocytoma. The pathological features, clinical implications, and treatment of low-grade astrocytomas in the pineal region are discussed.

An approach to the evaluation of hemostasis.

Effective hemostasis may be adequately and quickly evaluated using tests that are readily available in the usual hospital laboratory. This evaluation includes peripheral smear for platelet morphology and number, platelet count, bleeding time, activated partial thromboplastin time (aPTT), prothrombin time (PT), and clot retraction. Normal results of these tests exclude all but the mildest disturbances of hemostasis.

Multiple myeloma: presenting as a neurological disorder.

A case is reported of multiple myeloma presenting with signs and symptoms of paraplegia in a patient with a history of hypertension and remote cerebral vascular accident. The laboratory findings of hyperproteinemia and uricemia suggest a protein synthesizing abnormality. This case emphasizes that most patients with protein abnormality should be investigated by protein electrophoresis and immunoelectrophoresis.Unusual clinical presentation of multiple myeloma may result in an erroneous diagnosis unless proper investigation in the appropriate line is made.