Production of tumor necrosis factor and other cytokines by astrocytes stimulated with lipopolysaccharide or a neurotropic virus.

Rat astrocytes, immunologically competent glial cells of the central nervous system (CNS), released a variety of cytokines after activation. Lipopolysaccharide-stimulated astrocytes produced tumor necrosis factor (TNF) as demonstrated by Northern blot analysis using a mouse TNF probe and by functional assay. Biological activity of rat astrocyte-derived TNF was neutralized by rabbit antiserum against recombinant murine TNF. Stimulation of astrocytes by lipopolysaccharide also activated the interleukin 1 and interleukin 6 genes. We have also investigated whether a neurotropic paramyxovirus, Newcastle disease virus, triggers cytokine production by astrocytes. This virus induced astrocytes to produce TNF, lymphotoxin, interleukin 6, and alpha- and beta-interferons. Thus, stimulation by endotoxin and virus activated distinct, yet overlapping, sets of cytokine genes. We propose that astrocytes and the cytokines they produce may play a significant role in the pathogenesis of immunologically and/or virally mediated CNS disease, in CNS intercellular communication, and in the interactions between the nervous and immune systems.     

Vaterian cancer in siblings

The simultaneous occurrence of Vaterian carcinoma in two siblings suggests a genetic influence in their pathogenesis. Their classic clinical presentation of obstructive jaundice and weight loss required pancreaticoduodenectomy for this neoplasm. Pedigree analysis revealed a third sibling who died from an unresectable periampullary malignancy. Neither of the probands exhibited, as late as the seventh decade, evidence compatible with a diagnosis of familial polyposis coli or Gardner's syndrome. Flow cytometry studies revealed an aneuploid distribution in one tumor and tetraploid in the other. The rarity of this neoplasm, in the absence of contributing epidemiologic factors, suggests that this is a pleotrophic manifestation of a cancer-prone genotype.     

Testosterone in a Cyclodextrin-Containing Formulation: Behavioral and Physiological Effects of Episode-like Pulses in Rats

Testosterone, administered in the form of an inclusion complex with 2-hydroxypropyl--cyclodextrin by subcutaneous injection, enters the circulation in a manner markedly similar to the natural episodic release by the testes. The effects of a regimen of once-a-day administration of complexed testosterone to adult (castrated or intact) rats and to senescent (intact) rats were investigated. Although this procedure left the castrated animals with concentrations of circulatory hormone far below physiological levels for much of the day, a significant improvement in androgen-sensitive behavior and physiology was obtained. Furthermore, the testosterone effects were more pronounced when high doses were used periodically rather than when the same total amount of testosterone was equally divided among doses. The same supplementation to intact rats intensified androgen-sensitive behavior and physiology over normal levels. In senescent rats uniform pulses of the testosterone complex also improved behavior and physiology. Specifically, spermatogenesis was stimulated and, notably, the treatment increased muscle weight without substantial enlargement of the prostate. Since the testosterone–cyclodextrin complex also can be effectively administered as a sublingual tablet, the data suggest that similar regimens may be recommended for elderly men suffering from decreases in muscle mass.     

Carriers for drugs and enzymes based on copolymers of allyl glycidyl ether with acrylamide

Copolymerization of acrylamide with allyl glycidyl ether yielded water soluble polymers containing an epoxy group; addition of a crosslinking agent, N,N′-methylenebis(acrylamide), to the copolymerization mixtures resulted in the formation of similar though water insoluble polymers. Condensation of a potent beta-adrenergic antagonist Alm? H, which contains a reactive amino group, with a polymer containing an epoxy group yeilded a pharmacologically active polymer. The polymer containing the epoxy group was also converted, by reaction with sodium thiosulfate and subsequent reduction, into a mecapto groups containing polymer which was also water soluble. The latter polymer was converted by condensation with a beta-adrenergic antagonist Alm? COCH₂Br, which contains a reactive bromoacetamido group, into a pharmacologically active polymer.     

Differential effect of poly rI.rC and Newcastle disease virus on the expression of interferon and cellular genes in mouse cells

The expression of type I murine interferon (MuIFN) genes and several other cellular genes was examined in poly rI.rC induced and Newcastle disease virus (NDV) infected mouse cells. Northern analysis of RNA from induced L cells revealed that the MuIFN-alpha s are expressed efficiently in NDV infected cells but only at low levels in poly rI.rC induced cells. MuIFN-beta 1, however, is expressed equally well in cells treated with poly rI.rC or infected with NDV. As shown by the use of a probe specific for poly rI.rC, interferon induction correlates with the cellular uptake of poly rI.rC into the cells. The relative levels of alpha and beta 1 mRNAs in the cells reached a maximum at 10 hr after the induction which indicates coordinate expression of alpha and beta 1 interferon genes. The effect of viral infection on the expression of two murine genes coinduced with interferon (pMIF20/11 and pMIF3/10) and several cellular genes was also examined. While pMIF20/11 is an inducible gene, the pMIF3/10 gene is expressed constitutively in mouse L cells. Viral infection, but not poly rI.rC treatment, enhanced the expression of the pMIF3/10 gene, as well as two other cellular genes; H-2 and c-myc, however, the expression of beta-actin gene was unaltered. These data indicate that enhancement of gene expression in virus infected cells in not limited to the interferon system.     

Effect of interferon on the exogenous Friend murine leukemia virus infection

Interferon treatment (600 U/ml) of NIH/3T3 cells induced greater than 90% reduction in the de novo production of Friend MuLV when measured 24 hr postinfection. Early events in viral replication such as the synthesis of proviral DNA and its subsequent integration into the cell genome were not inhibited by interferon treatment indicating that the suppression of virus production by interferon appears to occur after synthesis of proviral DNA. Analysis of viral RNA species present in controls and interferon-treated cells 24 hr after infection show that the same RNA species were present in the presence and absence of interferon. Synthesis of viral polypeptides was reduced but not blocked in interferon-treated cells when measured within 24 hr after infection while processing of gag precursor, Pr65^gag, and glycoprotein precursor, gPr85^env, to viral proteins was not altered. Phosphorylation of viral protein p12 but not that of the precursor, Pr65^gag, was inhibited in newly infected interferon-treated cells. In contrast to the first replicative cycle, interferon did not inhibit synthesis of viral proteins, and phosphorylation of p12 in those cells chronically infected with F-MuLV.     

Diffuse glomerular basement membrane lamellation in renal allografts from pediatric donors to adult recipients

The transplantation of kidneys from pediatric cadaveric donors into adult recipients is performed in many centers. However, some studies indicate that the outcome of such renal transplants may be inferior compared with that of adult donors, particularly if the donor is an infant. Morphologic studies of failed pediatric donor kidneys in adult recipients describe various degrees of segmental or global glomerular sclerosis. The authors have performed ultrastructural examinations on such transplants and have identified six cases with diffuse irregular lamellation of the glomerular basement membrane (GBM), a change that may develop as early as 10 weeks after transplantation. The age of all donors was < or =6 years; three were infants. The incidence of the lesion was 9% at our institution in renal transplant patients who received a graft from donors <10 years old. Diffuse GBM lamellation has not been found in renal transplants from adult donors. Light microscopy showed various degrees of diffuse mesangial expansion, usually with segmental glomerular sclerosis. The patients had severe proteinuria. While recurrent focal segmental glomerular sclerosis (FSGS) has to be excluded, such diffuse GBM lamellation is generally not seen in recurrent FSGS cases. The pathogenesis of the lesion is most likely related to hyperperfusion injury of small pediatric donor kidneys grafted into adult recipients.     

Soluble adhesion molecules and cytokines in patients with myasthenia gravis treated by plasma exchange

Plasma exchange (PE) is an effective therapeutic method used in patients with myasthenia gravis (MG) refractory to common therapy and/or with life-threatening respiratory complications. Except for acetylcholine receptor antibodies (AChRAbs), some other inflammatory mediators possibly activated in MG may also be removed during PE. Serum levels of soluble adhesion molecules (sICAM-1 and sVCAM-1), IL-6 and soluble receptors for IL-2 (sIL-2R), IL-6 (sIL-6R) and TNF alpha (sTNF-R II) were measured in 20 MG patients assigned to treatment with PE. On the basis of the serum levels of AChRAb the patients were subdivided into 2 groups (8 patients with low AChRAb, 12 patients with high AChRAb). Soluble adhesion molecules and cytokines were measured before the first and last PE, at the end of the first PE and in the samples of plasma filtrate obtained during the first PE. Before the first PE patients with MG had higher serum levels of sICAM-1, sVCAM-1, sIL-2R and sTNF-R II than controls. Both after the first PE and during the course of PE, a substantial decrease in serum levels of AChRAb, sICAM-1 and sVCAM-1 was recorded. However, serum levels of sIL-2R and sTNF-R II were not significantly influenced by either a single treatment or during the course of PE. There were high levels of AChRAb, soluble adhesion molecules and soluble cytokine receptors in plasma filtrates too. Patients with high circulating AChRAb had higher serum levels of sICAM-1 and sVCAM-1 than patients with low AChRAb. Increased serum levels of soluble adhesion molecules and soluble cytokine receptors in patients with MG suggest some systemic activation of the immune response which is more pronounced in patients with high circulating AChRAb. PE led to the decrease in serum AChRAb and soluble adhesion molecules due to their effective filtration but, on the other hand, serum levels of soluble cytokine receptors were not influenced by PE, in spite of their effective filtration which is probably counteracted by their increased production, possibly stimulated by the contact of the blood with the synthetic membrane.