Preauricular pilomatrixoma: a diagnostic pitfall

Although pilomatrixomas are well known to dermatologists and dermatopathologists, surgeons encountering these lesions over the parotid gland frequently do not consider this benign neoplasm in the differential diagnosis. Presentation of a subcutaneous preauricular lesion, coupled with an erroneous cytologic diagnosis of malignancy, can potentially result in histologic "overdiagnosis" and more aggressive therapy than is required for these benign hair follicle neoplasms. A case is reported to illustrate this potential diagnostic trap, and a series of 206 cases collected at the University Hospital of Zurich from 1975 to 1987 is reviewed.     

Smoking.

Cigarette smoking remains a major health problem in not only the United States but the world. The dependency-producing effects of nicotine are well documented. Primary prevention, preventing the initiation of smoking, is receiving increased attention in the field of health education. Secondary prevention, smoking cessation, is showing promising results. Perhaps the goal of a smoke-free America by 2000 is not a "pipe dream" after all.     

A comparison of dementia in Alzheimer's disease and multiple sclerosis

We compared results of comprehensive neuropsychological testing in 42 patients with clinically diagnosed Alzheimer's disease (AD) and in an equal number of patients with clinically definite chronic-progressive multiple sclerosis. Age, sex, and education were controlled using demographically corrected T scores based on a large normal sample. Both groups showed significant impairment on the test battery, but the degree of dementia was more severe in the patients with AD. A deviation score analysis, controlling for overall level of cognitive impairment, revealed significant differences between the groups. Alzheimer's disease was associated with relatively greater impairment of learning, memory, and verbal skills, whereas the MS group showed greater relative impairment of attention, incidental memory, and psychomotor functions. These data suggest that both the degree and pattern of mental impairement differ in patients with AD and patients with multiple sclerosis. Our results support a distinction between "gray matter" and "white matter" dementia, and may help clarify the issue of "cortical" vs "subcortical" dementia by demonstrating neuropsychological differences based on secure neuropathologic distinctions.     

Comparing tobacco cigarette dependence with other drug dependencies. Greater or equal 'difficulty quitting' and 'urges to use,' but less 'pleasure' from cigarettes

About 1000 persons seeking treatment for alcohol or drug dependence were asked, relative to cigarettes, about the difficulty of quitting the use of the substance for which they were seeking treatment, the strength of their strongest urges to use, and the pleasure they derived from use. Fifty-seven percent said that cigarettes would be harder to quit using than their problem substance. These ratings were related to the level of cigarette dependence and the perceived difficulty of quitting the use of the problem substance. The alcohol-dependent persons were about four times more likely than the drug-dependent persons to say that their strongest urges for cigarettes were at least as great as their strongest urges for their problem substance. Cigarettes were generally rated as less pleasurable than alcohol or other drugs. Thus, experiential experts on dependence judge cigarette dependence as at least as "addictive" as other drug use, but not as pleasurable, indicating important similarities and differences between cigarette dependence and other forms of dependence on psychoactive substances.     

Analysis of orthologous gene expression between human pulmonary adenocarcinoma and a carcinogen-induced murine model

Human adenocarcinoma (AC) is the most frequently diagnosed human lung cancer, and its absolute incidence is increasing dramatically. Compared to human lung AC, the A/J mouse-urethane model exhibits similar histological appearance and molecular changes. We examined the gene expression profiles of human and murine lung tissues (normal or AC) and compared the two species' datasets after aligning approximately 7500 orthologous genes. A list of 409 gene classifiers (P value <0.0001), common to both species (joint classifiers), showed significant, positive correlation in expression levels between the two species. A number of previously reported expression changes were recapitulated in both species, such as changes in glycolytic enzymes and cell-cycle proteins. Unexpectedly, joint classifiers in angiogenesis were uniformly down-regulated in tumor tissues. The eicosanoid pathway enzymes prostacyclin synthase (PGIS) and inducible prostaglandin E(2) synthase (PGES) were joint classifiers that showed opposite effects in lung AC (PGIS down-regulated; PGES up-regulated). Finally, tissue microarrays identified the same protein expression pattern for PGIS and PGES in 108 different non-small cell lung cancer biopsies, and the detection of PGIS had statistically significant prognostic value in patient survival. Thus, the A/J mouse-urethane model reflects significant molecular details of human lung AC, and comparison of changes in orthologous gene expression may provide novel insights into lung carcinogenesis.     

Evaluation of three disk tests for identification of enterococci, leuconostocs, and pediococci.

Simple rapid tests for presumptive identification of catalase-negative non-beta-hemolytic cocci (i.e., enterococci, leuconostocs, and pediococci) have not previously been available. Seven hundred thirty-four strains of aerobic and facultatively anaerobic, catalase-negative, non-beta-hemolytic gram-positive cocci were tested for susceptibility to vancomycin (Vans) by a screening procedure and production of leucine aminopeptidase (LAPase) and pyrrolidonylarylamidase (PYRase) in disk tests. Three unique patterns of activity in response to the three disks (30 micrograms of vancomycin, PYRase, and LAPase) can be used to presumptively identify the vancomycin-resistant (Vanr) enterococci (Vanr and PYRase and LAPase positive), leuconostocs (Vanr and PYRase and LAPase negative), and pediococci (Vanr, PYRase negative, and LAPase positive). The results indicate that, together with Gram stain characteristics and the catalase test, the vancomycin, LAPase, and PYRase disk tests can be used to presumptively identify Vanr strains of enterococci as well as Leuconostoc and Pediococcus strains from human infections.     

Development of a rat model for respiratory infection with Bordetella pertussis.

Considerable effort directed toward designing a safe and effective vaccine for Bordetella pertussis in which the cellular and/or acellular antigens necessary to confer immunity are known has been hampered by lack of information on the pathogenesis of the natural infection. The study presented here describes an animal model of lung infection by B. pertussis encased in agar beads in adult (200- to 220-g) male Sprague-Dawley rats. At 3 and 7 days after inoculation with phase I B. pertussis, organisms could be recovered from the lungs of rats; however, organisms were not recoverable at days 10 and 14 but reappeared in lung homogenates at day 21. Histopathological examination revealed findings similar to those seen in human disease. At day 3, a mild lymphocytic infiltrate was present in the bronchi, with progressive lymphoid hyperplasia peribronchially. By day 7, a necrotizing inflammation of the tracheobronchial mucous membranes, characterized by both mononuclear and polymorphonuclear cells, was noted. Phase III B. pertussis organisms were not recoverable from the lungs of inoculated rats at day 3 after inoculation, nor were histological changes noted in these animals. Clinical findings in phase I B. pertussis-infected rats included hypoglycemia, circulating lymphocytosis, and paroxysms in which air was forcibly expelled from the mouth or nose.     

An analysis of myeloma plasma cell phenotype using antibodies defined at the IIIrd International Workshop on Human Leucocyte Differentiation Antigens.

Fresh bone marrow from 43 cases of myeloma and three cases of plasma cell leukaemia has been phenotyped both by indirect immune-rosetting and, on fixed cytospin preparations, by indirect immunofluorescence. Both clustered and unclustered B cell associated antibodies from the IIIrd International Workshop on Human Leucocyte Differentiation Antigens were used. The results confirm the lack of many pan-B antigens on the surface of myeloma plasma cells, i.e. CD19-23, 37, 39, w40. Strong surface reactivity is seen with CD38 antibodies and with one CD24 antibody (HB8). Weak reactions are sometimes obtained with CD9, 10 and 45R. On cytospin preparations CD37, 39 and w40 are sometimes weakly positive, and anti-rough endoplasmic reticulum antibodies are always strongly positive. Specific and surface-reacting antiplasma cell antibodies are still lacking.     

Detection of smallpox virus DNA by LightCycler PCR

A 300-bp plasmid fragment of the hemagglutinin gene was used as target DNA to develop a rapid real-time LightCycler (Roche Applied Science, Indianapolis, Ind.) PCR assay for laboratory detection of smallpox virus. PCR primers and probes were designed specifically for detection of smallpox virus DNA, but all viruses of the genus Orthopoxvirus tested could be detected by use of the hemagglutinin gene target sequence. Base pair mismatches in the 204-bp amplicon allowed discrimination of cowpox virus (melting temperature [T(m)], 56.40 degrees C), monkeypox virus (T(m), 56.24 degrees C), and vaccinia virus (T(m), 56.72 degrees C), including the Dryvax vaccine strain, from smallpox virus (T(m), 62.45 degrees C) by melting curve analysis. The analytical sensitivity was 5 to 10 copies of target DNA per sample. The assay was specific for members of the genus Orthopoxvirus; the DNAs of herpes simplex virus and varicella-zoster virus were not detected by the smallpox virus LightCycler PCR.     

Comparison of a new rapid test (TestPack Rotavirus) with standard enzyme immunoassay and electron microscopy for the detection of rotavirus in symptomatic hospitalized children.

We compared a new, rapid, qualitative test for rotavirus (TestPack Rotavirus; Abbott Laboratories, North Chicago, Ill.) with another enzyme immunoassay (Pathfinder Rotavirus; Kallestad Laboratories, Inc., Austin, Tex.) and electron microscopy to determine its clinical utility in a population of symptomatic hospitalized children. In the first part of the study, 100 frozen stool samples were tested. The results after resolution with a blocking reagent showed a sensitivity of only 50% and a specificity of 88% for TestPack Rotavirus. In the second part of the study, we tested TestPack Rotavirus on 100 fresh, unfrozen samples. The results (sensitivity/specificity) were as follows: TestPack Rotavirus, 95/90%; Pathfinder Rotavirus, 84/98%; direct electron microscopy, 63/100%. Although it was not as sensitive or specific as immune electron microscopy, TestPack Rotavirus was more sensitive than direct electron microscopy or Kallestad Pathfinder Rotavirus. TestPack Rotavirus represents a rapid, qualitative method for the detection of rotavirus in stools of symptomatic children.