Multiple sclerosis and the workplace: report of an industry-based cluster

Eleven cases of MS occurred within a 10-year period in a zinc-related manufacturing plant. The observed disease incidence was greater than expected from population data, using multiple approaches to statistical analysis (p less than or equal to 0.01). A case-control study, performed to examine several zinc parameters in blood, failed to indicate specific abnormalities among the MS patients, but all subjects (both MS and controls) working in the plant demonstrated higher serum zinc levels than all subjects (MS and controls) not working there.     

The vascular response to tumor infiltration in malignant gliomas

Summary Neo-vascularization and endothelial hyperplasia have been shown to be very active in malignant gliomas. In this contribution the vascularization of the cortex infiltrated by malignant gliomas is morphometrically studied and the endothelial proliferations are immunohistochemically investigated and reconstructed by a three-dimensional computer-assisted procedure. Vessel density increases after tumor infiltration in some cases only. The diameter of vessels increases and so does the number of nuclei/vessel after the complete invasion of the cortex when vascular glomeruli develop. In completely infiltrated cortex with development of glomeruli and circumscribed necroses, vessel density is very low. No neoformation of vessels takes place before the complete infiltration of the cortex by the tumor. The hyperplastic formations, usually arranged parallel to the deep or outer cortical layers, take origin from the radially penetrating vessels from the meninges and their lateral branching. The hyperplasia deforms the vascular network, making it often inadequate to supply tumor cells. Immunohistochemically, the cells composing the hyperplastic structures are variably positive for factor VIII/RAg and, at a lesser extent, for -smooth muscle actin. The poorness of the vascular network in many instances of completely infiltrated cortex is responsible for the development of circumscribed necroses.Supported by Grant 87.01446.44 CNR, Rome and by A. I. R. C., Milan. Presented in part at the 63rd Annual Meeting of the American Association of Neuropathologists, Seattle, Washington, June 11–14, 1987     

Human rotavirus specific T cells: quantification by ELISPOT and expression of homing receptors on CD4+ T cells

Using an intracellular cytokine assay, we recently showed that the frequencies of rotavirus (RV)-specific CD4(+) and CD8(+) T cells secreting INFgamma, circulating in RV infected and healthy adults, are very low compared to the frequencies of circulating cytomegalovirus (CMV) reactive T cells in comparable individuals. In children with acute RV infection, these T cells were barely or not detectable. In the present study, an ELISPOT assay enabled detection of circulating RV-specific INFgamma-secreting cells in children with RV diarrhea but not in children with non-RV diarrhea without evidence of a previous RV infection. Using microbead-enriched CD4(+) and CD8(+) T cell subsets, IFNgamma-secreting RV-specific CD8(+) but not CD4(+) T cells were detected in recently infected children. Using the same approach, both CD4(+) and CD8(+) RV-specific T cells were detected in healthy adults. Furthermore, stimulation of purified subsets of PBMC that express lymphocyte homing receptors demonstrated that RV-specific INFgamma-secreting CD4(+) T cells from adult volunteers preferentially express the intestinal homing receptor alpha4beta7, but not the peripheral lymph node homing receptor L-selectin. In contrast, CMV-specific INFgamma-secreting CD4(+) T cells preferentially express L-selectin but not alpha4beta7. These results suggest that the expression of homing receptors on virus-specific T cells depends on the organ where these cells were originally stimulated and that their capacity to secrete INFgamma is independent of the expression of these homing receptors.     

Diurnal rhythms of leptin and ghrelin in the systemic circulation and in the gastric mucosa are related to food intake in rats

We investigated diurnal changes in leptin and ghrelin levels in the stomach and in the systemic circulation and their relation to food intake rhythms in Wistar rats housed at 22 °C with a 12-h light/dark cycle and free access to food and water. Animals were sacrificed every 3 h over a 24-h period. Leptin and ghrelin levels in serum and in the gastric mucosa were analysed by immunoassay. Leptin mRNA levels were determined in the gastric mucosa by RT-PCR and in different adipose tissue depots (epididymal, retroperitoneal and mesenteric) by Northern blot. Ghrelin mRNA levels were determined by Northern blot. Gastric and serum leptin levels displayed similar diurnal rhythms, rising during the dark phase and decreasing gradually during the light phase. Leptin expression in the different adipose tissue depots correlated positively with circulating leptin levels (P<0.05), although there were some depot-associated differences. Leptin mRNA levels in the mesenteric depot correlated positively with food intake (P<0.05). In blood, ghrelin levels rose sharply just before the onset of the dark phase and dropped suddenly just after. In the stomach, ghrelin levels were high during the fasting period of light and low during the night, and correlated inversely with food intake, gastric contents and serum leptin levels (P<0.05). Leptin and ghrelin in the stomach and in the systemic circulation thus show diurnal variations that are influenced by food intake rhythms. The results agree with a role for ghrelin as a stimulant of meal initiation.     

Cross-reactive antigens and immunity to diseases caused by encapsulated bacteria.

Antigenic structures may be shared among naturally occurring polymers, including proteins and polysaccharides. Proteins are polymers of amino acids. Cross-reactions between proteins are due to similarities in their overall shape rather than their individual amino acid components. Cross-reactions have been demonstrated among proteins with similar evolutionary development and structure, such as serum albumins or immunoglobulins. Polysaccharides are polymers of monosaccharides. In contrast to proteins, antigenic specificities may be conferred by mono-, di-, and trisaccharides. Since there are about 150 known naturally occurring monosaccharides, it is not unexpected that cross-reactions are demonstrable between polysaccharides from widely divergent sources.     

S-100beta protein is upregulated in astrocytes and motor neurons in the spinal cord of patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron loss and astrogliosis. We studied the immunohistochemical expression of S-100beta, a calcium-binding protein with both neurotrophic and neurotoxic activities, in the spinal cord of patients with ALS. Adjacent sections were processed with an in situ end-labeling technique for the demonstration of apoptosis-related DNA fragmentation. In controls, low expression of S-100beta was found in astrocytes but not motor neurons. Compared to controls, S-100beta was overexpressed in ALS. Most stained cells were reactive astrocytes, but a minority of motor neurons was also labeled. Neuronal labeling was unrelated to the presence of signs of atrophy/degeneration. S-100beta expression was also unrelated to neuronal or glial apoptosis. S-100beta upregulation in ALS spinal cord suggests that the protein might be involved in cellular defense mechanisms against oxidative stress.     

An in vivo role for Trypanosoma cruzi calreticulin in antiangiogenesis

Angiogenesis leads to neovascularization from existing blood vessels. It is associated with tumor growth and metastasis and is regulated by pro- and antiangiogenic molecules, some of them currently under clinical trials for cancer treatment. During the last few years we have cloned, sequenced and expressed a Trypanosoma cruzi calreticulin gene (TcCRT). Its product, TcCRT, a 45 kDa protein, is more than 50% identical to human CRT (HuCRT). TcCRT, present on the surface of trypomastigotes, binds both C1q and mannan binding lectin and inhibits the classical activation pathway of human complement. Since TcCRT is highly homologous to a functional antiangiogenic fragment from HuCRT (aa 120–180), recombinant (r) and native (n) TcCRT were tested in their antiangiogenic effects, in the chick embryonic chorioallantoid membrane (CAM) assay. Both proteins mediated highly significant antiangiogenic effects in the in vivo CAM assay. This effect was further substantiated in experiments showing that the plasmid construct pSecTag/TcCRT also displayed significant antiangiogenic properties, as compared to the empty vector. Most likely, the fact that antiangiogenic substances act preferentially on growing neoplasic tissues, but not on already established tumors, is due to their effects on emerging blood vessels. The results shown here indicate that TcCRT, like its human counterpart, has antiangiogenic properties. These properties may explain, at least partly, the reported antineoplasic effect of experimental T. cruzi infection.     

Specific Differentiation between Mycobacterium bovis BCG and Virulent Strains of the Mycobacterium tuberculosis Complex

A PCR procedure based on the intergenic region (IR) separating two genes encoding a recently identified mycobacterial two-component system, named SenX3-RegX3, was developed and was shown to be suitable for identifying Mycobacterium bovis BCG. The senX3-regX3 IR contains a novel type of repetitive sequence, called mycobacterial interspersed repetitive units (MIRUs). All tested BCG strains exclusively contained 77-bp MIRUs within the senX3-regX3 IR, whereas all non-BCG M. tuberculosis complex strains contained a 53-bp MIRU, in addition to the 77-bp MIRUs. All 148 strains analyzed so far could be divided into eight different groups according to the copy numbers of the 77-bp MIRU and to the presence or absence of the 53-bp MIRU. BCG strains contained either one, two, or three 77-bp MIRUs. The other strains contained one to five 77-bp MIRUs invariably followed by a 53-bp MIRU. The consistent absence of the 53-bp MIRU in BCG strains and its presence in virulent strains allowed us to develop an enzyme-linked immunosorbent assay using specific capture oligonucleotide probes to distinguish between BCG and other M. tuberculosis complex strains.     

Multiple sclerosis. The problem of incorrect diagnosis

Various neurologic disorders may be diagnosed incorrectly as multiple sclerosis (MS) since there is no test that is entirely specific for the disease. We report ten patients who met clinical criteria for probable or definite MS and who were given incorrect diagnoses. All of the patients were subsequently shown to have alternative diagnoses, three of which were directly treatable. From these illustrative cases, five characteristics were identified that alerted us to the possibility of an alternative diagnosis. We have called these characteristics "red flags," and suggest that they may be useful as features casting doubt on the diagnosis of MS if used judiciously in conjunction with clinical diagnostic criteria.