Pancreatic adenocarcinomas with DNA replication errors (RER+) are associated with wild-type K-ras and characteristic histopathology. Poor differentiation, a syncytial growth pattern, and pushing borders suggest RER+.

The clinical and pathological features of carcinomas of the pancreas with DNA replication errors (RER+) have not been characterized. Eighty-two xenografted carcinomas of the pancreas were screened for DNA replication errors using polymerase chain reaction amplification of microsatellite markers. Cases with microsatellite instability in at least two markers of a minimum of five tested were considered RER+. RER status was correlated with histological appearance, karyotype of the carcinomas when available, K-ras mutational status, and patient outcome. Three (3.7%) of the eighty-two carcinomas were RER+. In contrast to typical gland-forming adenocarcinomas of the pancreas, all three RER+ carcinomas were poorly differentiated and had expanding borders and a prominent syncytial growth pattern. Neither a Crohn's-like lymphoid infiltrate nor extracellular mucin production were prominent. Ductal adenocarcinomas of the pancreas typically contain a mutant K-ras gene, yet all three RER+ carcinomas had wild-type K-ras. One of the three RER+ carcinomas was karyotyped and showed a near diploid pattern. All three of the RER+ tumors were removed via Whipple resection. One of the three patients is free of disease 16 months after pancreaticoduodenectomy, one is alive and free of tumor at 52 months but developed two colon carcinomas during this period, and the third died of pancreatic cancer at 4 months. None of the three patients had a family history of colorectal carcinoma. A review of the K-ras wild-type carcinomas in a previously characterized series of pancreatic carcinomas with known K-ras mutational status identified two additional cancers with poor differentiation, a syncytial growth pattern, and pushing borders. Both of the cancers were diploid and both patients were longterm survivors (over 5 years). The inclusion of such patients in previous prognostic studies of pancreas cancer may explain the failure of histological grade to be a predictor of prognosis. These data suggest that DNA replication errors occur in a small percentage of resected carcinomas of the pancreas and that wild-type K-ras gene status and a medullary phenotype characterized by poor differentiation, and expanding pattern of invasion, and syncytial growth should suggest the possibility of DNA replication errors in carcinomas of the pancreas.     

Immunoglobulin G1 enzyme-linked immunosorbent assay for diagnosis of Johne's Disease in red deer (Cervus elaphus)

This study was designed to develop a customized enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Johne's disease (JD) in farmed deer. Two antigens were selected on the basis of their superior diagnostic readouts: denatured purified protein derivative (PPDj) and undenatured protoplasmic antigen (PpAg). ELISA development was based on the antigen reactivity of the immunoglobulin G1 (IgG1) isotype, which is a highly specific marker for mycobacterial disease seroreactivity in deer. Sensitivity estimates and test parameters were established using 102 Mycobacterium paratuberculosis-infected animals from more than 10 deer herds, and specificity estimates were determined using 508 uninfected animals from 5 known disease-free herds. A receiver-operated characteristic analysis determined that at a cut point of 50 ELISA units, there was a specificity of 99.5% and sensitivities of 84.0% with PPDj antigen, 88.0% with PpAg, and 91.0% when the antigens were used serially in a composite test. Estimated sensitivity was further improved using recombinant protein antigens unique for M. paratuberculosis, which identified infected animals that were unreactive to PPDj or PpAg. While 80% of animals that were seropositive in the IgG1 ELISA had detectable histopathology, the assay could also detect animals with subclinical disease. The test was significantly less sensitive (75%) for animals that were culture positive for M. paratuberculosis but with no detectable pathology than for those with pathological evidence of JD (>90%). When the IgG1 ELISA was used annually over a 4-year period in a deer herd with high levels of clinical JD, it eliminated clinical disease, increased production levels, and reduced JD-related mortality.     

Effect of the 21-aminosteroid,U-74389F,on hyperoxic lung injury in rats

Hyperoxia (>95% oxygen) in rats caused an increase in lung weight and an accumulation of fluid in the thorax. The mean lung wet weight of air-breathing controls at 60 h was 1.2±0.01 g, and that of vehicle-treated, oxygen-exposed animals was 2.45±0.05 g. Treatment with the 21-aminosteroid U-74389F, 3, 10, and 30 mg/kg twice daily throughout oxygen exposure, produced 8, 42, and 18% inhibition of the oxygen-induced increase in lung weight, respectively. However, U-74389F did not inhibit the hyperoxia-induced accumulation of neutrophils in bronchoalveolar lavage fluid.

No pleural fluid could be aspirated from the thorax of air-breathing controls. The volume of pleural fluid in oxygen-exposed, vehicle-treated animals and animals treated with 3, 10, and 30 mg/kg U-74389F b.i.d. was 6.5±0.9, 2.6±0.6, 0.8±0.3, and 1.3±0.5 ml, respectively.

U-74389F or its biologs are of potential value for the treatment of lung diseases in which oxidant damage has been implicated.

     

Peak Identification in Visual Evoked Potentials

Waveform patterns evoked by 4 intensities of flash in normal subjects were studied in relation to intersubject variability. Time-frequency distribution curves of all peaks occurring between 11 and 280 msec after flash onset and meeting minimal criteria were obtained from 46 males. These distributions closely corresponded to similar data reported by others for single intensity stimulation. An algorithm was developed which identified in 67 to 100% of instances a single “peak event’ within the time ranges of each of 6 peak distributions. Many peak events appeared and disappeared within the 4 intensity sets of individuals. Latencies were obtained for these peak events. Application of the algorithm to a replicate sample of 29 Ss, which included 8 females, indicated generalizability. Test-retest data on 15 Ss showed its reliability. The data suggest that methodology significantly contributes to the variability of peak identification among subjects. This may be reduced by employing multiple intensities of stimulation.     

Extensive immune-mediated hippocampal damage in mice surviving infection with neuroadapted Sindbis virus

Viral infections of the central nervous system and immune responses to these infections cause a variety of neurological diseases. Infection of weanling mice with Sindbis virus causes acute nonfatal encephalomyelitis followed by clearance of infectious virus, but persistence of viral RNA. Infection with a neuroadapted strain of Sindbis virus (NSV) causes fatal encephalomyelitis, but passive transfer of immune serum after infection protects from fatal disease and infectious virus is cleared. To determine whether persistent NSV RNA is associated with neurological damage, we examined the brains of recovered mice and found progressive loss of the hippocampal gyrus, adjacent white matter, and deep cerebral cortex associated with mononuclear cell infiltration. Mice deficient in CD4(+) T cells showed less tissue loss, while mice lacking CD8(+) T cells showed lesions comparable to those in immunocompetent mice. Mice deficient in both CD4(+) and CD8(+) T cells developed severe tissue loss similar to immunocompetent mice and this was associated with extensive infiltration of macrophages. The number of CD4(+) cells and macrophage/microglial cells, but not CD8(+) cells, infiltrating the hippocampal gyrus was correlated with the number of terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling positive pyramidal neurons. These results suggest that CD4(+) T cells can promote progressive neuronal death and tissue injury, despite clearance of infectious virus.     

Isolation of brain parenchymal lymphocytes for flow cytometric analysis. Application to acute viral encephalitis.

A strategy for the isolation of mononuclear cells from the brain parenchyma of mice with ongoing central nervous system (CNS) inflammation has been developed in order to permit flow cytometric (FCM) analysis of these cell populations. Sindbis virus (SV) encephalitis in mice is characterized morphologically by an infiltration of mononuclear cells into both brain parenchyma and cerebrospinal fluid (CSF). Perfused brain tissue from infected animals is collected, homogenized, and subjected to a mild enzymatic digestion. A sedimentation at unit gravity is performed to remove any large particulate debris, and the remaining tissue is then centrifuged over a modified density gradient which separates intact cells from smaller tissue fragments. Cells collected directly from these gradients can be stained with monoclonal antibodies and analyzed by FCM without further manipulation. Data generated by this method correlates with previous studies of SV encephalitis using immunohistochemical analysis of brain tissue sections to quantify mononuclear cell types. This suggests that representative samples of the cellular infiltrate are obtained using this technique. The approach however, offers the possibility of more sophisticated and quantitative analyses of CNS inflammatory cells which is unobtainable by tissue section staining.     

Changes in neuronal size and neurotransmitter marker in hereditary canine spinal muscular atrophy

Hereditary canine spinal muscular atrophy (HCSMA) is a dominantly inherited motor neuron disease that produces muscle weakness and atrophy. Immunocytochemical and computer-imaging morphometric methods were used to compare early changes that occurred in dogs with HCSMA (n = 4) versus controls (n = 2). The size and number of neurons in the ventral horn and the number of motor neurons expressing choline acetyltransferase were quantitated. The density of all ventral horn neurons per micrometer squared in dogs with HCSMA was greater than controls, and there were more small neurons than in controls. Immunocytochemical methods revealed more small cholinergic neurons and fewer large cholinergic neurons in HCSMA than in controls, suggesting growth arrest in HCSMA or a shift in size class from large cholinergic neurons to small ones. The density of cholinergic neurons per micrometer squared was not significantly different between the two groups. Analysis of predicted distributions of cholinergic and noncholinergic neurons revealed that HCSMA cholinergic neurons were smaller and that, in some size classes, fewer neurons expressed choline acetyltransferase. These observations indicate that in HCSMA the motor neuron fails to achieve normal size and/or undergoes atrophy.     

Purification and characterization of two functionally distinct forms of C1 inhibitor from a patient with angioedema.

A minority of patients with hereditary angioedema (HAE) have normal concentrations of a dysfunctional C1 inhibitor protein (C1INH) in their plasmas. We purified C1INH from the plasmas of one such patient before and during treatment with the anabolic steroid stanozolol. Both the pretreatment plasma and plasma obtained during stanozolol treatment contained varying amounts of two extremely similar C1INH proteins that were functionally distinct. The pretreatment plasma contained primarily (94%) dysfunctional C1INH that did not inactivate or complex with either purified C1s, activated Hageman factor, or kallikrein and small amounts (6%) of functionally normal C1INH. Stanozolol treatment increased the plasma concentrations of both of these proteins as well as the proportion (23%) of functional C1INH in the plasma. The purified dysfunctional and functional C1INHs had identical or nearly identical molecular sizes, charges, amino acid compositions, and amino sugar contents, and could not be distinguished physicochemically from each other or from normal C1INH. From these studies of purified C1INH proteins we concluded that HAE associated with dysfunctional C1INH is due to a defect at the structural locus for one C1INH gene and that both the dysfunctional C1INH gene and the normal C1INH gene products are present in the plasma of the affected subject. Treatment with stanozolol comparably increased the synthesis of both C1INH proteins. The disproportionate rise in the level of the normal C1INH protein is consistent with the view that it is more rapidly catabolized as a consequence of its interaction with the proteases it inactivates.