Experimental Escherichia coli ascending pyelonephritis in rats: changes in bacterial properties and the immune response to surface antigens.

Systemic and urinary antibody responses were examined in rats with experimental ascending pyelonephritis caused by Escherichia coli O6K13H1. During 12-month follow-up of the infections, bacterial characteristics of the urinary and renal isolates were followed: O and K antigenicity, sensitivity to the bactericidal effect of normal human serum, capacity to attach to urinary tract epithelial cells, hemolytic activity, biochemical pattern, and virulence. During the long-term infection, the urinary and renal bacterial isolates changed in O and K antigenicity, serum sensitivity, and virulence. The adhesive capacity of the bacterial isolates did not change, possibly explaining the persistence of the bacteria in the urinary tract. The serum anti-O6 antibody levels remained high during the entire 1-year observation period, especially in the rats with renal involvement. Urinary anti-O6 antibodies were also found. The serum and urinary antibodies could have played a role in bringing about the observed changes in bacterial characteristics. Antibodies to lipid A were recorded in 9 of 16 rats with pyelonephritis and renal scarring and in 1 of 9 rats not having pyelonephritis or renal bacterial growth.     

In vivo treatment with W3/13 (anti-pan T) but not with OX8 (anti-suppressor/cytotoxic T) monoclonal antibodies impedes the development of adjuvant arthritis in rats.

The involvement of phenotypically defined cells in the pathogenesis of adjuvant arthritis in rats has been investigated in two different ways. Firstly, immunohistochemical methods have been used to characterize the cellular composition of the arthritic synovial tissue, in particular the pannus tissue close to the destroyed cartilage. It is shown that T-helper lymphocytes dominate the lymphoid infiltrates, and that large numbers of cells expressing Ia are present in the pannus. Secondly, different anti-T cell monoclonal antibodies have been injected into rats in vivo and disease course and phenotypes of synovial cells investigated after different types of treatment. It is shown that the injection of W3/13 (anti-pan T-cell antibodies) delays the development of adjuvant arthritis, whereas a complete elimination of the suppressor/cytotoxic T-cell subset after injection of OX8 antibodies does not affect the disease course.     

Localization and axonal transport of immunoreactive cholinergic organelles in rat motor neurons—An immunofluorescent study

Antisera produced in rabbits against pure fractions of cholinergic vesicles from Narcine brasiliensis were used to study cholinergic organelles in rat motor neurons. The indirect immunofluorescence method was used on perfusion-fixed material. The rats were surgically sympathectomized to remove sympathetic adrenergic and cholinergic nerves from the sciatic nerve. In the intact animal immunoreactive material, likely to represent cholinergic vesicles, was observed in motor endplates, identified by labelling with rhodamine-conjugated α-bungarotoxin or with subsequent acetylcholinesterase staining. The motor perikarya contained very little immunoreactive material. Non-terminal axons were virtually devoid of immunofluorescence in the intact animal. After crushing the sciatic nerve, immunoreactive material (likely to represent axonal cholinergic organelles) accumulated rapidly on both sides of the crush, indicating a rapid bidirectional transport. The transport was sensitive to local application of mitotic inhibitors.The axons which accumulated immunoreactive organelles were motor axons, as demonstrated by various procedures: (1) Cutting of ventral roots prevented accumulation of immunoreactive material in the nerve. (2) Deafferentation did not notably influence accumulations of immunoreactive material. (3) Ligated axons with immunoreactive material were acetylcholinesterase positive when identification was made on the same section; the intra-axonal distribution of immunoreactive material and acetylcholinesterase was not identical, however, and the Narcine antisera did not cross-react with bovine acetylcholinesterase in a solid phase immunoassay. (4) Most axons in ventral roots, but not in dorsal roots, accumulated strongly fluorescent immunoreactive material, while axons in dorsal roots contained weakly fluorescent material. On the other hand, substance P-like immune reactivity was present in many dorsal root axons, but only very rarely in ventral roots.It is suggested that the antisera against Narcine cholinergic vesicles can be used as a marker for cholinergic organelles in the motor neuron, and may be an important tool for studying the axonal cholinergic vesicles. It cannot, however, be used to identify cholinergic structures in unknown locations because it recognizes common antigenic determinants in transmitter organelles of other nerves e.g. adrenergic nerves. The axonal cholinergic organelles may carry important molecules, other than acetylcholine to the nerve endings.     

Beneficial Role of Human Endogenous Retroviruses: Facts and Hypotheses

Human endogenous retroviruses (HERVs) have recently been suggested as mediators of normal biological processes such as cellular differentiation and regulation of gene expression. Moreover, a direct role for HERVs in pathogenesis and the development of disease is now better appreciated. Elucidation of the mechanisms regulating HERV biology should provide information about fundamental cellular activities and the pathogenesis of multifactorial diseases such as cancer and autoimmune disease. The importance of understanding the roles of HERVs is underscored by the recently obtained insight that activation of endogenous retroviruses poses potential risks following xenotransplantation and in gene therapy using retroviral vectors. Furthermore, HERV-encoded superantigens have recently been implicated as causes of autoimmune disease. This review discusses the established and possible biological roles of HERVs, and proposes hypotheses concerning their involvement as mediators of fundamental cellular responses. We propose that the evolutionary persistence of endogenous retroviruses in the genomes of eukaryotic cells reflects their indispensability in important normal functions in specialized cellular environments. HERVs can also be potentially hazardous through their involvement in the development of disease. In addition, the creation of new retroviruses can occur through recombination, between different HERVs and between HERVs and exogenous retroviruses.     

Gas chromatographic determination of D-arabinitol/L-arabinitol ratios in urine: a potential method for diagnosis of disseminated candidiasis.

A gas chromatographic procedure was developed to determine the relative amounts of D- and L-arabinitol in urine. Samples were filtered, diluted, purified through extractions, evaporated, and treated with trifluoroacetic anhydride; the arabinitol derivatives thus obtained were separated on a chiral stationary phase and registered by using an electron-capture detector. Urine samples from a patient with disseminated candidiasis had higher D-arabinitol/L-arabinitol ratios (referred to as D/L-arabinitol ratios)--up to 19.0--than samples from 96 study individuals with no signs of deep Candida infections (range, 1.1 to 4.5). D/L-Arabinitol ratios in urine samples from hospitalized patients without Candida infections were slightly higher than those in samples from healthy individuals; ratios in urine from children were slightly higher than those in adult urine samples. The D/L-arabinitol ratios in several urine samples culture positive for Candida albicans, but from patients without symptoms of disseminated candidiasis, did not differ from those in the urine of healthy individuals. The described gas chromatographic method is straightforward and can be implemented clinically to determine urine D/L-arabinitol ratios as a means of diagnosing disseminated candidiasis.     

Missense mutations in the human glutathione synthetase gene result in severe metabolic acidosis, 5-oxoprolinuria, hemolytic anemia and neurological dysfunction

Severe glutathione synthetase (GS) deficiency is a rare genetic disorder with neonatal onset. The enzymatic block of the gamma-glutamyl cycle leads to a generalized glutathione deficiency. Clinically affected patients present with severe metabolic acidosis, 5- oxoprolinuria, increased rate of hemolysis and defective function of the central nervous system. The disorder is inherited in an autosomal recessive mode and, until recently, the molecular basis has remained unknown. We have sequenced 18 GS alleles associated with enzyme deficiency and we detected missense mutations by direct sequencing of cDNAs and genomic DNA. In total, 13 different mutations were identified. Four patients were found to be compound heterozygotes and two individuals were apparently homozygous. Reduced enzymatic activities were demonstrated in recombinant protein expressed from cDNAs in four cases with different missense mutations. The results from biochemical analysis of patient specimens, supported by the properties of the expressed mutant proteins, indicate that a residual activity is present in affected individuals. Our results suggest that complete loss of function of both GS alleles is probably lethal. It is postulated that missense mutations will account for the phenotype in the majority of patients with severe GS deficiency.      

Impaired temperature regulation in rats after anosmia induced peripherally or centrally

Bilateral olfactory bulbectomy or destruction of the olfactory epithelium of rats resulted in elevated body temperature in room temperature, and lowered water/food ratio in 30 degrees ambient temperature. The results suggest the involvement of the olfactory system in the thermoregulation.     

Mitochondrial and microsomal peripheral benzodiazepine receptors in human ovarian cancer xenografts

To investigate whether the density of peripheral benzodiazepine receptors (PBR) in human ovarian tumors is related to the degree of histological differentiation and possibly elucidate their pathophysiology, PBR were measured in mitochondrial (m) and microsomal (p) fractions isolated from six different human ovarian carcinomas heterotransplanted into nude mice. A specific ligand PK11195 for PBR was employed and the density of binding sites and binding affinity (KD) were computed from Scatchard analysis. The PBR density in m-fractions was 3- to 4-fold higher than in p-fractions from all tumors. PBR density in both m- and p-fractions was highest in mucinous tumors with mid-high degree of differentiation. The density in serous tumor with mid-high differentiation was significantly lower than the mucinous tumor, but higher than the serous tumor with low degree of differentiation (OVCAR-3) in both m- and p-fractions. However, the PBR density in the undifferentiated tumor (IGROV1) was higher than in OVCAR-3. The KD values for PBR were very low ranging from 5.8 to 14.0 nM in all preparations. The KD values for p-fractions were generally lower than m-fractions and highly significant differences were observed in three of the six tumors. These data suggest two separate classes of PBR pertaining to m- and p-fractions and indicate that there is no clear relationship between PBR density and degree of differentiation.