Micropapillary carcinoma of the parotid gland arising in mucinous cystadenoma

We describe a 45-year-old man who had a 2-year history of a slowly enlarging tumor in the left parotid gland. Histologically, the tumor was a mucinous cystadenoma with focal apocrine differentiation, which revealed a widespread invasive micropapillary adenocarcinoma component. A rim of lymphoid tissue surrounded the margins of the micropapillary carcinoma. The invasive micropapillary adenocarcinoma component was morphologically identical with the invasive micropapillary carcinoma of the mammary gland. The tumor is different from so-far recognized salivary gland tumor entities. Received: 25 October 1999 / Accepted: 13 June 2000     

Verification of the exponential model of body temperature decrease after death in pigs

The authors have conducted a systematic study in pigs to verify the models of post-mortem body temperature decrease currently employed in forensic medicine. Twenty-four hour automatic temperature recordings were performed in four body sites starting 1.25 h after pig killing in an industrial slaughterhouse under typical environmental conditions (19.5-22.5 degrees C). The animals had been randomly selected under a regular manufacturing process. The temperature decrease time plots drawn starting 75 min after death for the eyeball, the orbit soft tissues, the rectum and muscle tissue were found to fit the single-exponential thermodynamic model originally proposed by H. Rainy in 1868. In view of the actual intersubject variability, the addition of a second exponential term to the model was demonstrated to be statistically insignificant. Therefore, the two-exponential model for death time estimation frequently recommended in the forensic medicine literature, even if theoretically substantiated for individual test cases, provides no advantage as regards the reliability of estimation in an actual case. The improvement of the precision of time of death estimation by the reconstruction of an individual curve on the basis of two dead body temperature measurements taken 1 h apart or taken continuously for a longer time (about 4 h), has also been proved incorrect. It was demonstrated that the reported increase of precision of time of death estimation due to use of a multiexponential model, with individual exponential terms to account for the cooling rate of the specific body sites separately, is artifactual. The results of this study support the use of the eyeball and/or the orbit soft tissues as temperature measuring sites at times shortly after death. A single-exponential model applied to the eyeball cooling has been shown to provide a very precise estimation of the time of death up to approximately 13 h after death. For the period thereafter, a better estimation of the time of death is obtained from temperature data collected from the muscles or the rectum.     

Influence of D-glucose on lipid solid support membrane system as attempt for biosensing of medically relevant molecules

The influence of D-glucose on a lipid solid support system with the aid of impedance spectrocopy as a preliminary attempt for the biosensing of medical relevant molecules was studied. In spite of some shortcomings, s-BLM's proved to be an appropriate model for the study of lipid membrane-D-glucose interactions. The shortcomings were the roughness of the metal support, and the lack of homogeneity in the monolayer or multilayer lipid structures.     

Effects of neutrophil, natural killer cell, and macrophage depletion on murine Clostridium piliforme infection.

Clostridium piliforme infection (Tyzzer's disease) induces enterohepatic disease in many domestic and laboratory animals. Murine susceptibility to Tyzzer's disease varies with host strain, age, and immune status However, little is known about the role of the immune system in control of this disease. To investigate the role of host immunity in Tyzzer's disease, mice were depleted of either neutrophils, natural killer cells, or macrophages by antibody administration or chemotherapy. After depletion, DBA/2 mice, which are naturally susceptible to C. piliforme, or naturally resistant C57BL/6 mice were inoculated intravenously with C. piliforme. Animals were euthanized 3 days postinoculation and evaluated for gross and histologic lesions and hepatic bacterial load. In juvenile DBA/2 or C57BL/6 mice, depletion of either neutrophils or natural killer cells increased severity of disease. In adult mice, depletion of natural killer cells significantly increased severity of Tyzzer's disease in the resistant (C57BL/6) but not in the susceptible (DBA/2) strain. Macrophage depletion did not alter the course of infection in either mouse strain. These studies indicate an important role for neutrophils and natural killer cells in the pathogenesis of murine Tyzzer's disease. The role of macrophages in murine C. piliforme infection will require further evaluation.     

Long-lived alphaMUPA transgenic mice show reduced SOD2 expression, enhanced apoptosis and reduced susceptibility to the carcinogen dimethylhydrazine

Calorie restriction (CR) extends the life span of various species through mechanisms that are as yet unclear. Recently, we have reported that mitochondrion-mediated apoptosis was enhanced in alphaMUPA transgenic mice that spontaneously eat less and live longer compared with their wild-type (WT) control mice. To understand the molecular mechanisms underlying the increased apoptosis, we compared alphaMUPA and WT mice for parameters associated with SOD2 (MnSOD), a mitochondrial antioxidant enzyme that converts superoxide radicals into H(2)O(2) and is also known to inhibit apoptosis. The SOD2-related parameters included the levels of SOD2 mRNA, immunoreactivity and enzymatic activity in the liver, lipid oxidation and aconitase activity in isolated liver mitochondria, and the sensitivity of the mice to paraquat, an agent that elicits oxidative stress. In addition, we compared the mice for the levels of SOD2 mRNA after treatment with bacterial lipopolysaccharides (LPS), and for the DNA binding activity of NFkappaB as a marker for the inflammatory state. We extended SOD2 determination to the colon, where we also examined the formation of pre-neoplastic aberrant crypt foci (ACF) following treatment with dimethylhydrazine (DMH), a colonic organotypic carcinogen. Overall, alphaMUPA mice showed reduced basal levels of SOD2 gene expression and activity concomitantly with reduced lipid oxidation, increased aconitase activity and enhanced paraquat sensitivity, while maintaining the capacity to produce high levels of SOD2 in response to the inflammatory stimulus. alphaMUPA mice also showed increased resistance to DMH-induced pre-neoplasia. Collectively, these data are consistent with a model, in which an optimal fine-tuning of SOD2 throughout a long-term regimen of reduced eating could contribute to longevity, at least in the alphaMUPA mice.     

The role of IL-18 and IL-12 in the modulation of matrix metalloproteinases and their tissue inhibitors in monocytic cells

The matrix metalloproteinases (MMP) are enzymes crucial for the physiological patrol as well as pathological chemotaxis of immune cells to target tissues. The present study examined differential effects of pro-inflammatory [IL-18, IL-12 and tumor necrosis factor (TNF)-alpha] versus anti-inflammatory (IL-4) cytokines on the modulation of MMP and their endogenous tissue inhibitors (TIMP) expression in the U937 cell line. IL-18 and IL-12 separately and synergistically enhanced MMP-2, while TNF-alpha led to the elevation of MMP-9. All pro-inflammatory cytokines enhanced MT1-MMP expression and IL-4 suppressed TNF-alpha-induced MMP-9 expression. This study demonstrated that elevated IL-18 and IL-12, and related pro-inflammatory activity, may be associated with aberrant MMP activity, suggesting modulation of MMP expression using IL-12 and IL-18 antagonists as future therapeutic strategies to attenuate inflammatory and autoimmune disorders.