Search

The onset of mild cognitive impairment (MCI) is an essential outcome in Alzheimer's disease (AD) prevention trials and a compelling milestone for clinically meaningful change. Determining MCI, however, may be variable and subject to disagreement. Adjudication procedures may improve the reliability of these determinations. We report the performance of an adjudication committee for an AD prevention trial.The TOMMORROW prevention trial selected cognitively normal participants at increased genetic risk for AD and randomized them to low-dose pioglitazone or placebo treatment. When adjudication criteria were triggered, a participant's clinical information was randomly assigned to a three-member panel of a six-member independent adjudication committee. Determination of whether or not a participant reached MCI due to AD or AD dementia proceeded through up to three review stages - independent review, collaborative review, and full committee review - requiring a unanimous decision and ratification by the chair.Of 3494 participants randomized, the committee adjudicated on 648 cases from 386 participants, resulting in 96 primary endpoint events. Most participants had cases that were adjudicated once (n = 235, 60.9%); the rest had cases that were adjudicated multiple times. Cases were evenly distributed among the eight possible three-member panels. Most adjudicated cases (485/648, 74.8%) were decided within the independent review (stage 1); 14.0% required broader collaborative review (stage 2), and 11.1% needed full committee discussion (stage 3). The primary endpoint event decision rate was 39/485 (8.0%) for stage 1, 29/91 (31.9%) for stage 2, and 28/72 (38.9%) for stage 3. Agreement between the primary event outcomes supported by investigators' clinical diagnoses and the decisions of the adjudication committee increased from 50% to approximately 93% (after around 100 cases) before settling at 80-90% for the remainder of the study.The adjudication process was designed to provide independent, consistent determinations of the trial endpoints. These outcomes demonstrated the extent of uncertainty among trial investigators and agreement between adjudicators when the transition to MCI due to AD was prospectively assessed. These methods may inform clinical endpoint determination in future AD secondary prevention studies. Reliable, accurate assessment of clinical events is critical for prevention trials and may mean the difference between success and failure.

Additional file 1 : Supplemental Table S1. Primary antibodies for WB. Supplemental Table S2. Autopsy gross parameters. Supplemental Table S3. IHC results. Supplemental Table S4. Mutations in DIPG. Supplemental Table S5. CNVs. Supplemental Figure S1. Radiologic characteristics of DIPG cases. A. F5 MRI: axial (left and center) and coronal (right) T2W-FLAIR images showing hyperintense diffusely infiltrating pontine mass extending posteriorly into the right cerebellum and rostrally into the midbrain and subthalamus. Images were acquired 2.5 months pre-mortem. B-C. F10 MRI at initial diagnosis (B) and 10 months later (C) showing rim-enhancing pontocerebellar mass with initial extension into the left cerebellum (B) and subsequent extension into the right cerebellum and frontal periventricular region (C). Yellow arrows show post-contrast enhancing tumor foci. D. F12 axial and sagittal T2W-FLAIR images acquired 1-month pre-mortem showing the frontal and cerebellar secondary foci with yellow arrows. Supplemental Figure S2. Example of histologic examination for H&E quantified analysis. F12 H&E sections are shown at the levels schematically illustrated on a normal brain coronal section. Higher magnification of areas marked with small blue squares are shown in adjacent pictures with blue borders. Note massive infiltration of periventricular areas, white matter tracts, septum pellucidum, hippocampus, brainstem and cerebellum (red arrow shows the invasive tumor front in the left cerebellum) by neoplastic cells with pleomorphic nuclei resembling glioblastoma. LV, lateral ventricle; R, right; L, left. Supplemental Figure S3. Variable ultrastructural morphology of neoplastic cells in DIPG. A. Variable nuclear morphology of F5 neoplastic cells, showing elongated/fibrillary forms (yellow arrows) admixed with larger forms (blue arrows). The red arrow indicates a myelinated axon “hugged” by a fibrillary neoplastic cell. B. F10 larger neoplastic astrocyte with abundant cytoplasm (blue arrow) dissecting the myelinated axons (red arrow) of the corpus callosum. C. F12 neoplastic astrocytes with nuclear pleomorphism (blue arrows) within the frontal white matter (myelinated axons shown with red arrows and oligodendroglia shown with green arrow). D. F12 large pontine fibrillary neoplastic astrocyte with prominent nucleolus. Supplemental Figure S4. Ganglioglioma-like pontine focus in DIPG. F10 H&E of a focal proliferation of large binucleated dysplastic ganglion cells, interspersed with small astrocytic neoplastic cells, conferring a typical ganglioglioma appearance to a limited pontine area of the tumor. IHC and NGS following microdissection of this area revealed histone H3 K27M mutation in all the neoplastic cells, consistent with DMG/K27M. Supplemental Figure S5. IHC profiles in DIPG. IHC with indicated antibodies of the pontine tumor areas from F5, F10 biopsy and autopsy, and F12. The F10 autopsy focus of dysplastic binucleated ganglion cells (red arrows) is shown. These cells express GFAP but not vimentin, whereas the small neoplastic cells express both types of intermediate filaments. Supplemental Figure S6. Quantitative protein expression analysis in DIPG. A-B. Bar graphs representing the indicated protein levels from various foci of the 3 DIPG autopsies. The quantification of the WB bands was performed by densitometric analysis, as described in Material and Methods. Individual densitometric values were normalized to the corresponding actin values. In (B), the phosphoprotein values were normalized to the corresponding total unphosphorylated protein values, as indicated. Results are expressed as fold-increase or fold-decrease in comparison to normal control. The WBs for each antibody were repeated at least twice, with similar results. The labeling is as in Fig. 4: T, tumor; N, normal; primary pontine (P) foci indicated in red; secondary cerebellar (C) and frontal (Fr) foci, in green. Sample laterality: R, right; L, left. For the tri-methylated histone H3 K27 residue (H3K27Me3) antibody in (A) that showed undetectable expression in both normal and tumor samples, the WB was repeated in the presence of a positive control from an autopsy case of glioblastoma, IDH-mutant, WHO grade IV, known to harbor increased levels of H3 K27 tri-methylation.

Genetics as a discipline is fundamental for the pharmaceutical industry; it contributes to all therapeutic areas and has an impact throughout the research and development continuum, right up to and including clinical practice. Pharmacogenetics is seen as a significant contributor to increasing the efficiency and effectiveness of pharmaceutical R&D, and it enhances the growing interest in personalized medicine. This article discusses some contemporary issues that influence drug development and examines the potential of pharmacogenetics to reduce the risk and uncertainty that are inherent in the drug development process.

E-selectin elicits cell adhesion by binding to the cell surface carbohydrate, sialyl Lewis X (sLe(x)). We evaluated the effects of mutations in the E-selectin lectin domain on the binding of a panel of anti-E-selectin mAbs and on the recognition of immobilized sLe(x) glycolipid. Functional residues were then superimposed onto a three-dimensional model of the E-selectin lectin domain. This analysis demonstrated that the epitopes recognized by blocking mAbs map to a patch near the antiparallel beta sheet derived from the NH2 and COOH termini of the lectin domain and two adjacent loops. Mutations that affect sLe(x) binding map to this same region. These results thus define a small region of the E-selectin lectin domain that is critical for carbohydrate recognition.

To examine the possible involvement of cytokines in reperfusion injury, we have studied production of IL-1 by human vascular cells, including smooth muscle and mononuclear phagocytes. Exposure of cells to hypoxia (pO2 approximately 14 torr) followed by reoxygenation led to significant release of IL-1 only from the mononuclear phagocytes. Elaboration of IL-1 was dependent on the oxygen tension and duration of hypoxia (optimal at lower pO2s, approximately 14-20 torr, and after 9 h), as well as the time in reoxygenation (maximal IL-1 release at 6-9 h). Although a period of hypoxia was necessary for subsequent IL-1 production during reoxygenation of either peripheral blood monocytes or cultured monocyte-derived macrophages, no IL-1 release occurred during the hypoxic exposure. IL-1 released during reoxygenation was newly synthesized, and its production was triggered by the generation of oxygen free radicals, as it could be blocked by the addition of either allopurinol or free radical scavengers to cultures and could be stimulated in part by low concentrations of hydrogen peroxide or xanthine/xanthine oxidase. The potential pathophysiological effects of IL-1-containing supernatants from reoxygenated macrophages was shown by their induction of endothelial tissue factor and enhancement of endothelial adhesiveness for neutrophils, both of which could be blocked by anti-IL-1 antibody. The relevance of IL-1 to hypoxia/reoxygenation in vivo was suggested by the presence of circulating nanogram amounts of this cytokine in the plasma of mice during the reoxygenation period following a hypoxia.

This article surveys common causes and pathologic features of nervous system infections within the general population. Special consideration is given to infections in people with the HIV virus.

To identify the genetic determinants of typical obesity, we performed a genome-wide scan of obesity-related traits using data from the Amish. Multipoint linkage analysis was performed using a variance components procedure on body mass index (BMI), waist circumference, percentage of body fat, and serum leptin concentrations. All 672 individuals were genotyped for 357 markers in 22 autosomes. We observed modest evidence for linkage, with the maximum log odds (lod) scores for linkage for these traits occurring on chromosomes 3p (percentage of body fat: lod = 1.61, near the peroxisome proliferator-activated receptor-alpha gene), 14q (waist: lod = 1.80), and 16p (leptin: lod = 1.72; BMI: lod = 1.68). We also tested for linkage to BMI-adjusted leptin concentrations and observed suggestive evidence for linkage on chromosome 10p (lod = 2.73), approximately 10-20 cM telomeric from obesity loci previously reported in French and German Caucasians. Two additional linkage signals for this trait were observed on chromosomes 7q (lod = 1.77, approximately 20 cM from the leptin gene) and 14q (lod = 2.47). Follow-up studies may be warranted to pursue some of these linkage signals, especially those detected near known obesity candidate genes, and those in regions coinciding with linkage signals reported previously.

Papillary meningioma is a rare subtype of meningioma that often behaves aggressively. In order to characterize factors that may influence this behavior, we chose to compare MIB-1 labeling index (LI) and telomerase RNA localization (hTR) in papillary meningiomas, meningiomas, and atypical meningiomas. LI is now often used to supplement histologic grade in the evaluation of these lesions. More recent studies indicate that increased expression of hTR is detected in many neoplastic cells, and may play an essential role in cell immortalization. The study group consisted of five papillary meningiomas (and a recurrence in one case), 11 conventional meningiomas, and eight atypical meningiomas. Conventional meningiomas showed either negative or 1 + hTR. Atypical meningiomas showed 1 + hTR. Papillary meningiomas showed the highest hTR (five of six, including recurrence, 2-3+ and one 1+). Generally, the LI was very low for conventional meningiomas (2%). The LI of atypical meningiomas ranged from 3-19%, mean 12%, and from 5.5-17.5%, mean 11.75% for papillary meningiomas. LI differentiated between meningiomas, and papillary or atypical meningiomas. hTR further delineated papillary (moderate to high) from atypical meningiomas (low). The combined variable of LI and hTR expression could be a useful independent prognostic indicator in patients with papillary meningioma.

McArdle's disease or myophosphorylase deficiency is one of the most common muscle glycogenoses and typically presents in childhood or adolescence with exercise intolerance, myalgia, myoglobinuria, and cramps in exercising muscle. We describe an elderly man who developed asymmetric proximal arm weakness at age 73. He had no history of exercise-induced cramps, myalgias, or myoglobinuria. Creatine kinase levels were elevated, serum lactate did not rise on ischemic exercise testing, and muscle biopsy showed a vacuolar myopathy with absent myophosphorylase activity. This unusual case demonstrates that McArdle's disease may present with fixed, asymmetric proximal weakness at an advanced age and should be considered in this clinical setting, especially when a history of poor exercise tolerance can be elicited.

A 38-year-old woman with insulin-dependent diabetes mellitus, hypertension, and end-stage renal disease developed digital ischemia, widespread cutaneous necrosis and eschar formation of both lower extremities, and extensive ulceration of the large intestine and cecum resulting in gastrointestinal hemorrhage. A mesenteric arteriogram revealed multiple stenotic areas and filling defects of the superior mesenteric artery and its tributaries, suggestive of vasculitis. A diagnosis of calciphylaxis was suspected, on antemortem skin biopsy, and was later confirmed by postmortem examination. This case further documents the relationship between calciphylaxis and significant visceral injury, and it represents, to our knowledge, the first case of calciphylaxis associated with massive gastrointestinal hemorrhage.

Type 2 diabetes mellitus is a common chronic disease that is thought to have a substantial genetic basis. Identification of the genes responsible has been hampered by the complex nature of the syndrome. Abnormalities in insulin secretion and insulin action predict the development of type 2 diabetes and are, themselves, highly heritable traits. Since fewer genes may contribute to these precursors of type 2 diabetes than to the overall syndrome, such genes may be easier to identify. We, therefore, undertook an autosomal genomic scan to identify loci linked to prediabetic traits in Pima Indians, a population with a high prevalence of type 2 diabetes. 363 nondiabetic Pima Indians were genotyped at 516 polymorphic microsatellite markers on all 22 autosomes. Linkage analyses were performed using three methods (single-marker, nonparametric multipoint [MAPMAKER/SIBS], and variance components multipoint). These analyses provided evidence for linkage at several chromosomal regions, including 3q21-24 linked to fasting plasma insulin concentration and in vivo insulin action, 4p15-q12 linked to fasting plasma insulin concentration, 9q21 linked to 2-h insulin concentration during oral glucose tolerance testing, and 22q12-13 linked to fasting plasma glucose concentration. These results suggest loci that may harbor genes contributing to type 2 diabetes in Pima Indians. None of the linkages exceeded a LOD score of 3.6 (a 5% probability of occurring in a genome-wide scan). These findings must, therefore, be considered tentative until extended in this population or replicated in others.

In order to characterize the endogenous gene product for rad (ras-related protein associated with diabetes), we prepared antibodies to synthetic peptides that correspond to amino acids (109-121, 178-195, 254-271) within the protein. These antibodies were used to analyze the expression, structure, and function of rad. Western analysis with these antibodies revealed that rad was a 46 kDa protein which was expressed during myotube formation. Further, immunolocalization studies showed that rad localized to thin filamentous regions in skeletal muscle. Interestingly, when muscle biopsies from diabetic and control Pima Indians were compared, no differences in rad protein or mRNA expression were observed. Similarly, no differences were observed in protein expression in diabetic and control Zucker diabetic fatty (ZDF) rats. Functional analysis of muscle rad revealed that its GTP-binding activity was inhibited by the addition of N-ethylmaliemide, GTP, GTP gamma S, and GDP beta S but not ATP or dithiothreitol. Moreover, cytosol-dependent rad-GTPase activity was stimulated by the peptide corresponding to amino acids 109-121. Antibodies corresponding to this epitope inhibited cytosol-dependent rad-GTPase activity. Taken together, the results indicate that 1) rad is a 46 kDa GTP-binding protein localized to thin filaments in muscle and its expression increases during myoblast fusion, 2) expression of rad in Pima Indians and ZDF rats does not correlate with diabetes, and 3) the amino acids (109-121) may be involved in regulating rad-GTPase activity, perhaps by interacting with a cytosolic factor(s) regulating nucleotide exchange and/or hydrolysis.

We report a set of triplets, two of whom were monochorionic diamnionic and demonstrated cerebellar hypoplasia and progressive arthrogryposis on an antenatal sonogram. At delivery the infants exhibited a Pena-Shokier phenotype. At autopsy, the twins were concordant for severe disruptive lesions of the cerebrum. The mechanism resulting in the devastating symmetric lesions may have been a transient cerebral vascular compromise associated with placenta vascular anastomoses characteristic of monochorionic twinning. This report accentuates the vulnerability of the monochorionic twin for ischemic cerebral injury.

A variety of adhesion molecules have been identified which mediate the interaction of leukocytes with endothelial cells. In order to define the role of individual molecules in inflammation we have produced lines of mice which are deficient in the synthesis of specific adhesion molecules. Null mutations were introduced into the genes encoding E-selectin or vascular cell adhesion molecule-1 (VCAM-1) in embryonic stem cells and these cells were used to produce lines of mice carrying the mutation. E-selectin-deficient mice were viable and exhibited no developmental defects. The roles of E- and P-selectin in the influx of neutrophils were examined using these mice. The data suggest that the two selectins are functionally redundant in mediating neutrophil emigration in a model of chemically induced peritonitis. VCAM-1-deficient mice are not viable. Analysis of VCAM-1 gene expression in wild-type embryos and phenotypic analysis of VCAM-1 -/- embryos suggests that VCAM-1 is required for development of the extraembryonic circulatory system and the embryonic heart.

E-selectin, also known as endothelial leukocyte adhesion molecule-1 (ELAM-1), is transiently expressed on endothelial cells in response to inflammatory cytokines such as IL-1 and TNF-alpha and mediates adhesion of leukocytes. The genomic structure of E-selectin is highly conserved and includes multiple polyadenylation signals and a number of AUUUA transcript destabilizing elements within the 3'-untranslated region (UTR). Anchored-PCR analysis indicates that all three polyadenylation signals within the human E-selectin 3'-UTR are indeed functional, and three forms of E-selectin transcripts (Types I, II, and III) generated by differential usage of these polyadenylation signals were detected in both cytokine-stimulated primary human endothelial cells and human skin tissue cultures. Although the longest transcript (Type III) is the most abundant form found in cytokine-stimulated human endothelial cells and human skin tissue cultures in vitro, only the shortest transcript (Type I) is detected in human dermal biopsies expressing cell surface E-selectin. Interestingly, the Type I E-selectin transcript lacks six of the mRNA destabilizing elements that are thought to mediate rapid degradation of the corresponding mRNA. In agreement with the absence of these mRNA decay signals, we determined that the Type I E-selectin transcript is more stable than the full-length Type III E-selectin transcript in an in vitro chimeric mRNA stability assay. Therefore, the presence of only the Type I transcript in skin biopsies of chronic inflammatory lesions suggests that differential polyadenylation of E-selectin transcripts may provide the molecular basis for the observed chronic expression of E-selectin in human dermal disorders.

Hypothermia is a frequent occurrence in newborns, and thermoregulatory management is a fundamental part of medical stabilization. Although modest reduction in brain temperature (2-3 degrees C) before ischemia provides neuroprotection in adults, the effect of modest hypothermia on immature brain has not been examined. Nine-day-old swine were exposed to 15 min of incomplete global brain ischemia, with intraischemic rectal temperatures of either 38.3 +/- 0.4 degrees C (n = 10, normothermic) or 35.4 +/- 0.5 degrees C (n = 10, hypothermic). The relationship between rectal and brain temperature was delineated in preliminary experiments on four swine. Animals with intraischemic rectal temperatures maintained at either 39.5 degrees C or 35.5 degrees C were associated with a similar magnitude of difference in brain temperature. Therefore, rectal temperature was used to monitor brain temperature for 20 animals studied subsequently. Ischemia was induced by combining neck compression with hemorrhagic hypotension and resulted in similar group values for mean arterial pressure and changes in pH and blood gases at the completion of ischemia. A clinical overall performance score and brain tissue structure were evaluated after 72 h (or earlier if animals died prematurely). Hypothermic animals had less severe stages of impairment compared with the normothermic group (p = 0.023). Hypothermic piglets had less histologic damage in the neocortex at 0.5 cm beneath the brain surface (p = 0.048), the caudate nucleus (p = 0.038), and the pons/midbrain (p = 0.04) and the same direction of effect in neocortex at 1 cm beneath the surface (p = 0.07) and the cerebellum (p = 0.07) as compared with normothermic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

To study the structural characteristics of E-selectin necessary for mediating cell adhesion, we examined the role of the consensus repeat (CR) domains in E-selectin function. Soluble constructs containing different numbers of CR domains were stably expressed in Chinese hamster ovary cells, purified to homogeneity, and characterized. The minimum functional unit of soluble E-selectin consisted of the lectin (Lec) and epidermal growth factor (EGF) domains alone (Lec-EGF) as indicated by its ability to mediate in vitro HL-60 cell adhesion. However, E-selectin containing all six CR domains (Lec-EGF-CR6) at its COOH terminus was the most potent in blocking neutrophil or HL-60 cell adhesion to either immobilized E-selectin or cytokine-stimulated human umbilical vein endothelial cells. This increased potency of Lec-EGF-CR6 in blocking cell adhesion was not due to CR-mediated oligomerization of the protein. Lec-EGF-CR6 was most likely monomeric in solution, as judged by gel filtration fast protein liquid chromatography, membrane ultrafiltration, and chemical cross-linking analysis. Therefore, although the lectin and EGF domains are necessary and sufficient for mediating cell adhesion, the additional six CR domains, present in native E-selectin, contribute to the enhanced binding of E-selectin to its ligand.

Central nervous system disease has emerged as an important manifestation of acquired immunodeficiency syndrome in both the adult and pediatric populations, with neurologic abnormalities occurring in up to 90% of pediatric patients in some series. Neuropathologic studies, based primarily on the autopsy, have provided valuable insights into the spectrum and pathogenesis of acquired immunodeficiency syndrome-associated neurologic disorders, including primary human immunodeficiency virus encephalopathy and as the spectrum of infectious, neoplastic, and cerebrovascular diseases that may complicate the course of acquired immunodeficiency syndrome. Progressive encephalopathy represents the single most common neurologic disorder in pediatric acquired immunodeficiency syndrome and appears to be caused in most cases by direct infection in brain parenchyma by human immunodeficiency virus. Central nervous system lymphoma and cerebrovascular disease continue to account for most focal central nervous system lesions in the pediatric population. In contrast to adults with acquired immunodeficiency syndrome, opportunistic central nervous system infections remain relatively uncommon in the pediatric population. Our understanding of acquired immunodeficiency syndrome-associated neurologic disease remains far from complete. A plea is made for regular postmortem examination of the central nervous system in all patients dying with human immunodeficiency virus infection.

Although it has been suggested that cytomegalovirus (CMV) infection of the kidney might facilitate the development of human immunodeficiency virus-associated nephropathy (HIVAN) or other morphologic renal changes in patients with AIDS, no systematic study has been performed on kidneys from AIDS patients. We examined 75 autopsy kidneys, two renal biopsy specimens, and a nephrectomy specimen from 78 HIV-infected patients (five with HIVAN) for the presence of CMV. Immunocytochemistry (ICC) utilizing a monoclonal antibody against the late antigen of CMV and in situ hybridization (ISH) with a biotinylated DNA probe for CMV sequences were used. The detection system for both ICC and ISH was streptavidin-conjugated alkaline phosphatase with Fast Red TR chromogen. CMV was detected in only 10 of the 78 kidneys examined (12.8%): eight by both methods, one by ISH only, and another by ICC only. All 10 positive kidneys were obtained from autopsies of patients with AIDS. The average number of positive cells (in approximately 15 x 10 mm sections) was 22 with ICC and 10 with ISH. Glomerular intracapillary cells (possibly endothelial cells) were the most commonly stained, followed by positive cells in the interstitium and peritubular capillaries. Relatively few tubular epithelial cells were stained. The majority of positive cells by either ICC or ISH did not show nuclear or cytoplasmic inclusions; however, only two of the 10 positive kidneys did not contain cells with typical Cowdry type-A intranuclear CMV inclusions. The most frequent pathologic finding in the kidneys positive for CMV by either ICC or ISH was acute tubular necrosis (in six of 10, 60%).(ABSTRACT TRUNCATED AT 250 WORDS)

A number of studies have suggested that HIV infection can be detected in a variety of routinely fixed archival tissues using antibodies to various viral proteins. In order to study this immunocytochemical approach, paraffin sections were examined with a large panel of commercially available monoclonal antibodies against the various HIV proteins (5 antibodies to p24, 1 to p17, 1 to gp41, and 1 to gp120) using a streptavidin-biotin method. A polyclonal antibody against p24 was also tested. Formalin-fixed, paraffin-embedded HIV infected CEM E5 T cells were used as positive controls. Tissues from AIDS patients included 31 kidneys, 8 lymph nodes, 2 spleens and 3 brains. Non-AIDS tissues examined were 6 renal biopsies with focal segmental glomerulosclerosis, 5 with interstitial nephritis, 6 reactive lymph nodes, and a brain with encephalitis, all from patients not known to be at high risk for HIV infection. Additional negative controls included: 1) replacement of primary antibody with a hybridoma derived mouse monoclonal IgG1 standard, 2) omission of the primary antibody, and 3) sections of formalin-fixed paraffin-embedded CEM E5 T cells cultures not infected with HIV. Competition experiments with excess recombinant p24 protein were also performed. False positive staining with the IgG1 standard or with the antibodies to HIV proteins was frequently seen in tissues with pathologic findings (inflammation, hyalin degeneration), particularly following protein digestion. Protein digestion also had a major impact on specific staining. Digestion with proteinase K abolished specific staining for the core proteins of the virus (p17, p24) on the positive control sections.(ABSTRACT TRUNCATED AT 250 WORDS)

Postmortem neuropathologic changes were evaluated in 141 consecutive patients dying with human immunodeficiency virus infection at publicly supported hospitals affiliated with the University of Texas Southwestern Medical Center in Dallas, between August 1984 and September 1990. Morphologic abnormalities were identified in 112 cases (79%). Cytomegalovirus was the most common opportunistic infection encountered, with characteristic viral inclusions identified in 23 patients, and presumptive evidence of infection in six additional patients. Progressive multifocal leukoencephalopathy was present in four patients. Gram-positive bacterial infections were identified in six patients, and mycobacterial infections in three patients. Opportunistic fungal infections included cryptococcosis (13 cases), histoplasmosis (two cases), and coccidioidomycosis (one case). Toxoplasmosis was uncommon, with active or quiescent lesions identified in five patients. Lymphoma was present in nine patients and was primary in the central nervous system in five patients. Multinucleate giant cell (human immunodeficiency virus) encephalitis was identified in 28 patients. In an additional 26 patients, microglial nodules and/or more generalized white-matter abnormalities were encountered in the absence of multinucleate giant cells, cytomegalovirus inclusions, or systemic cytomegalovirus infection. Vacuolar change was present in 21% of spinal cords, and was highly correlated with cytomegalovirus infection in the nervous system. Mixed infections and/or neoplasms were identified in 24 patients. This survey documents a high frequency of neuropathologic abnormalities in human immunodeficiency virus-infected individuals in a geographical region of the United States not represented in previous series. Variations noted in the frequencies of specific central nervous system disorders between this and other study populations reinforce the need for continuing documentation of geographical trends in human immunodeficiency virus-associated disorders.

Ribosomal (r) proteins encoded by polyadenylated RNA were specifically precipitated in vitro from polysomes by using antibodies raised against characterized Drosophila melanogaster r proteins. The immuno-purified mRNA in the polysome complex was used to prepare cDNA with which to probe a D. melanogaster genomic library. Selected recombinant phages were used to hybrid select mRNAs, which were analyzed by in vitro translation. Three clones containing the genes for r proteins 7/8, S18, and L12 were positively identified by electrophoresis of the translation products in one-dimensional and two-dimensional polyacrylamide gels. Sequences encoding r proteins S18 and L12 were found to be present in the genome in single copies. In contrast, the polynucleotide containing the region encoding 7/8 may be repeated or may contain or be flanked by short repeated sequences. The sizes of mRNAs that hybridized to the recombinant clone containing 7/8 were significantly larger than would be expected from the molecular weight of protein 7/8, implying that there were unusually long 5' and 3' noncoding sequences. The mRNAs for r proteins S18 and L12 were however, only about 10% larger. In situ hybridizations to salivary gland polytene chromosomes, using the recombinant phage, revealed that the recombinant clone containing the gene for r protein 7/8 hybridized to 5D on the X chromosome; the recombinant clone containing the gene for S18 hybridized to 15B on the same chromosome, and the recombinant phage containing the gene for L12 hybridized to 62E on chromosome 3L. It is of interest that the genomic locations of all three r protein clones were within the chromosomal intervals known to contain the Minute mutations [M(1)0, M(1)30, and M(3)LS2]. Although each clone contained sequences specifying two to four proteins, none had more than one identifiable r protein gene, suggesting that different D. melanogaster r protein genes may not be closely linked.

[β-14C]Styrene was prepared by the action of [14C]paraformaldehyde on phenylmethylene triphenyl phosphorane; the latter was prepared from benzyl chloride and triphenyl phosphine via phenyl methyl triphenyl phosphonium chloride. No radiochemical impurities were detected in the product. The radiochemical yield was 30.8%.

Polyarteritis nodosa is a multisystem disease that involves the gastrointestinal tract in more than 50% of patients at some time during its course. Clinically apparent ischemic disease of the small bowel is the frequent site of involvement. The colon is less commonly involved, particularly as the initial presentation. We present a patient with polyarteritis nodosa noteworthy for prolonged nonbloody diarrhea, ischemic colitis with perforation, and pseudomembrane formation who had histological documentation of polyarteritis nodosa.

Pigmented neoplasms of the peripheral nervous system are uncommon. Such lesions, while well documented in the para-axial region, are infrequently encountered in more peripheral extra-axial sites. The authors present a case of a melanocytic schwannoma arising in the gastric antrum of a 51-year-old woman. Ultrastructural features attesting to the nerve sheath origin of the neoplasm included the presence of a well-developed basal lamina, complex infoldings of the plasma membrane, and intercellular bundles of long spaced collagen ("Luse bodies"). Premelanosomes and melanosomes in all stages of development were identified within the cytoplasm of many of the neoplastic cells, providing morphologic support for a close relationship between Schwann cells and melanocytes. Immunoperoxidase studies with S-100 protein disclosed intense cytoplasmic staining throughout the tumor. The S-100 protein antigen has been documented in both nerve sheath elements and melanocytes; this shared antigenicity lends further support to the close relationship between melanocytic and schwannian elements suggested by ultrastructural observations. Additional immunoperoxidase studies employing antibody to glial fibrillary acidic protein revealed focal cytoplasmic staining, an uncommon phenomenon in peripheral nerve sheath neoplasms. A review of the literature failed to provide any previous well documented cases of melanocytic schwannoma of the stomach. The patient was treated with en bloc resection of the tumor and gastric antrum, and was free of evidence of recurrent or metastatic disease 22 months postoperatively. Theories regarding the histogenesis of pigmented nerve sheath neoplasms and prognostic implications are discussed, based on experience with this and previously reported pigmented nerve sheath tumors.

Tuberculous aortitis is a rare entity and its association with necrosis and perforation is even more unusual. Our pulmonary medicine service originally evaluated an elderly woman with a right pleural effusion and upper lobe infiltrate thought to be tuberculosis. An abdominal CT scan performed at that time showed extensive periaortic adenopathy. Isoniazid and rifampin were started, but both were stopped by the patient after less than 6 months of therapy. The patient later had night sweats, a left pleural effusion, and a tender abdominal mass thought to be a symptomatic aneurysm. At operation, the aorta was necrotic and had an inflammatory mass and perforation on the left side. Infrarenal aortic ligation and resection were performed to control infection. A previously placed axillofemoral graft obviated the need for concomitant revascularization. The patient was treated postoperatively with isoniazid and rifampin until hyperbilirubinemia developed, which necessitated alternate therapy with ethambutol and streptomycin. The patient died one month after operation of a presumed pulmonary embolus.

The U.K. Health and Safety Executive's (HSE) National Exposure Database (NEDB) enables the storage and selective retrieval of occupational hygiene data. These data are used to inform policy-making and standard-setting bodies, such as the Advisory Committee on Toxic Substances (ACTS), of national trends in exposure to particular substances categorized into the various industries, processes and jobs at which exposures occur. The exposure data currently held are limited to those obtained from inspections and investigations carried out by HSE specialist inspectors. Discussion is under way with industry on how the database can be extended to include validated data provided by industry so as to provide a focal point for exposure data in the U.K. The database will thereby become a valuable source of information for industry. Standardization of the way in which exposure data and qualifying information are presented will assist in fulfilling these aims. The paper describes the structure of the database, the types of information input to it and the information which can be obtained from it. Organizations wishing to establish their own exposure databases, those who may wish to contribute data, and the many who are concerned with the collection and recording of occupational hygiene data, irrespective of the methods of storage and retrieval, are encouraged to use a similar format.

Stress ulceration continues to be a problem in critically ill surgical patients and occasionally occurs even when prophylaxis is attempted with standard agents. Tube feedings protect against ulceration in clinical settings. Many tube feeding formulas and intragastric 25 per cent glucose alone prevent gastric lesions in the rat restraint model. Endogenous cytoprotective prostaglandin release is stimulated by the application of hyperosmolar sugar solutions to the gastric mucosa. To determine whether all or part of the protection afforded by 25 per cent glucose is mediated through stimulation of endogenous prostaglandins, hyperosmolar glucose was tested in restrained rats with and without concurrent cyclo-oxygenase blockade. Intragastric hyperosmolar glucose protected against gross and microscopic gastric lesions, raised the blood glucose level and elevated the gastric mucosal pH. Although cyclo-oxygenase blockade alone worsened the lesions produced by restraint, blocking cyclo-oxygenase in the rats given 25 per cent glucose did not lessen the protective effect of hyperosmolar sugar. We conclude that endogenous prostaglandins are useful in gastric mucosal defense but are not necessary for the protection afforded by 25 per cent glucose. It is likely that providing glucose directly to the stressed gastric mucosa enhances several aspects of gastric mucosal defense.

The rRNA genes (rDNA) in Drosophila melanogaster are found in two clusters, one on the X and one on the Y chromosome. We have compared the ribosomal protein composition of wild-type Oregon-R flies containing both X-linked and Y-linked rDNA with that of flies containing only the Y-linked rDNA by two-dimensional polyacrylamide gel electrophoresis. Four basic proteins (1, 2/3, L4, and L7) normally present in wild-type flies were either electrophoretically not detectable (1, 2/3, and L4) or marginally detectable (L7) in flies with only Y-linked rDNA. No additional proteins were observed in these flies. However, immunodiffusion assays using specific antibodies raised against purified protein L4 confirmed that L4 was present but in relatively lower amounts in these Y-linked rDNA flies. An investigation was carried out to determine whether these electrophoretically undetectable proteins were more readily lost during ribosome preparation and hence were not readily detectable in the 80S particles by gel electrophoresis or whether they had been modified. Thus the proteins in the post-ribosomal cell supernatant and the high salt sucrose gradient were analyzed by two-dimensional gel electrophoresis and immunochemical assays with antibodies raised against protein L4 and total 80S ribosomal proteins. The experimental evidence indicates that there is a small amount of protein L4 and probably proteins 1, 2/3, and L7 in flies with only Y-linked rDNA but significantly less of these proteins than in wild-type flies.