Mycobacterium kansasii and human immunodeficiency virus co-infection in London

In a sample of 627 healthy German children and adolescents between the age of 1 and 18 years the intake of macronutrients (protein, fat, carbohydrates) and their specific subgroups (animal protein, saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), cholesterol, added sugars, dietary fiber) were assessed from 3d weighed diet records. The medians of the nutrient intake (% of energy) were 13% protein (2/3 animal), 38% fat, 49% carbohydrates, 17% SFA, 16% MUFA, 5% PUFA, 12% added sugars and (per MJ) 34 mg cholesterol, 1.9 g dietary fiber. The macronutrient patterns were almost uniform across the age and sex groups with the exception of lower fat, PUFA, and sugar intakes in the 1 year olds. The findings were almost in accordance with former and current dietary surveys in Germany and neighboring countries. Several findings, particularly the high SFA and low fiber intake, differed considerably from the diet for the prevention of the chronic diseases related to nutrition in western societies which is recommended for this age range. Based on the findings of this study, a preventive dietary concept for German children and adolescents was proposed.     

Modulation of the activity of RNase E in vitro by RNA sequences and secondary structures 5' to cleavage sites

The endoribonuclease RNase E is believed to initiate the degradation of many mRNAs in Escherichia coli, yet the mechanism by which it recognizes cleavage sites is poorly understood. We have prepared derivatives of the mRNA encoding ribosomal protein S20 which contain a single major RNase E cleavage site at residues 300/301 preceded by variable 5' extensions. Three of these RNAs are cleaved in vitro with significantly reduced efficiencies relative to the intact S20 mRNA by both crude RNase E and pure Rne protein (endonuclease component of RNase E). In all three substrates as well as in the full-length mRNA the major cleavage site itself remains single-stranded. One such substrate (t84D) contains a 5' stem-loop structure characterized by three noncanonical A-G pairs. Removal or denaturation of the stem restores efficient cleavage at the major RNase E site. The other two contain single-stranded 5'-termini but apparently lack cleavage sites near the termini. Our data show that sensitivity to RNase E can be influenced by distant structural motifs in the RNA and also suggest a model in which the initial recognition and cleavage of a substrate near its 5' end facilitates sequential cleavages at more distal sites. The model implies that RNase E contains at least a dimer of the Rne subunit and that the products of the first cleavage are retained by Rne prior to the second cleavage.     

Activity wheel running blunts increased plasma adrenocorticotrophin (ACTH) after footshock and cage-switch stress

N'-(3'-Monophospho-deoxyguanosin-8-yl)-N-acetylbenzidine (dGp-ABZ) is thought to play an important role in initiation of benzidine-induced bladder cancer in humans. This report assesses the possible formation of this adduct by peroxidatic activation of N-acetylbenzidine (ABZ). Adduct formation was measured by 32P-post-labeling. Ram seminal vesicle microsomes were used as a source of prostaglandin H synthase (PHS). The peroxidatic activity of PHS was compared with that for horseradish peroxidase. Both peroxidases converted ABZ to dGp-ABZ whether DNA or 2'-deoxyguanosine 3'-monophosphate (dGp) was present. Following 32P-post-labeling, the enzymatic and synthetic adduct were extracted from PEI-cellulose plates and were shown to have the same HPLC elution profiles for the bisphosphate adduct (32P-dpGp-ABZ). Treatment of the enzymatic and synthetic bisphosphate adduct with nuclease P1 yielded a product that eluted at the same time from the HPLC (32P-dpG-ABZ). Additional experiments demonstrated that the PHS-derived 5'-monophosphate (dpG-ABZ) and 3'-monophosphate (dGp-ABZ) adducts were also identical to their corresponding synthetic standard. With comparable amounts of total ABZ metabolism, PHS produced approximately 40-fold more dGp-ABZ than horseradish peroxidase (1943 +/- 339 versus 49 +/- 7.8 fmol/mg dGp). Adduct formation was dependent upon the presence of peroxidase and the specific substrate, i.e. arachidonic acid or H2O2. Adduct formation by PHS was inhibited by indomethacin (0.1 mM), ascorbic acid (1 mM) and glutathione (10 mM), but not by 5,5-dimethyl-1-pyrroline N-oxide (DMPO) (100 mM), a radical scavenger. Horseradish peroxidase adduct formation was also inhibited by ascorbic acid and glutathione. In addition, DMPO elicited greater than a 96% inhibition. Results demonstrate peroxidatic metabolism of ABZ to form dGp-ABZ. The mechanism of dGp-ABZ formation by PHS and horseradish peroxidase may be different.     

Effect of rHuEpo therapy in dialysis patients on endogenous erythropoietin synthesis after renal transplantation

BACKGROUND: Pertussis is a highly contagious respiratory disease and the most serious effects occur in young infants. Recently it has been shown that rapid and highly specific PCR can be a useful diagnostic tool for detection of pertussis infection. To our knowledge there are no previous studies concerning the disappearance of Bordetella pertussis DNA from the nasopharynx during antimicrobial treatment. METHODS: We studied prospectively how rapidly live B. pertussis organisms and DNA of these bacteria disappear from the nasopharynx during erythromycin therapy in unvaccinated infants. Eighty-five nasopharyngeal swabs obtained from nine erythromycin-treated infants with pertussis on consecutive days during hospitalization were tested by PCR and culture. The PCR products were further analyzed by Southern hybridization. RESULTS: On the fourth day of treatment 56% of the samples were positive by culture and 89% by PCR, whereas after 7 days the rates were 0 and 56%, respectively. In seven of nine patients PCR remained positive for 1 to 7 days longer than culture. The follow-up study also showed the semiquantitative nature of the PCR assay. The intensity of the PCR products in agarose gel usually weakened with time during erythromycin therapy. CONCLUSIONS: The results of this study show that PCR assay can achieve the specific diagnosis of pertussis infection in a large proportion of infants even when antimicrobial treatment has killed the organisms and culture is no longer positive.     

Coronary artery perforation with rotational coronary atherectomy]

We tried to determine whether women with a urinary tract infection (UTI) were more likely to have had a recent pelvic examination than were women seen for other reasons. We compared 56 women who were diagnosed as having a UTI with 49 controls who had an unrelated complaint (sinusitis). Significantly more women with UTIs had received a pelvic examination within the preceding 2 months (43% vs 16%, P = .01). We conclude that having a pelvic examination is associated with an increased risk of a UTI developing within the following 2 months. This may be due to physical factors related to the examination or to risk factors related to the patients' reasons for obtaining a pelvic examination. Further study is needed to determine if the pelvic examination is an independent risk factor. If so, established preventive measures could reduce this risk.     

Interpretation of intraocular and serum antibody levels in necrotizing retinitis

BACKGROUND: Intraocular antibodies have been measured as a diagnostic aid in necrotizing retinitis but interpretation of results may be difficult. METHODS: Vitreous or aqueous and serum immunoglobulin G antibodies to toxoplasmosis, cytomegalovirus, herpes simplex virus I and II, and varicella zoster virus were subjected to enzyme-linked immunosorbent assay in 27 patients with necrotizing retinitis and 15 control patients. A quotient was derived quantitating the amount of excess antibody in the eye compared to serum. Different interpretative rules were analyzed to determine which yielded the highest sensitivity and specificity. RESULTS: The highest intraocular antibody relative to serum among the 4 antibodies correctly predicted the final clinical diagnosis in 21 of 27 patients, for a sensitivity of 78% and a specificity of 90%. Interpretive rules that relied on a high numeric value of the antibody quotient or did not consider the relative ranking of the four antibody quotients were less sensitive and specific because multiple antibodies were detected in most eyes. The technique was safe and rapid. CONCLUSION: Interpretation of antibody titers in intraocular fluids is facilitated by testing several relevant antibodies and comparing the results. The technique may be helpful to diagnose necrotizing retinitis and to ascertain viral cause in acute retinal necrosis.     

Binding of anti-CD23 monoclonal antibody to the leucine zipper motif of FcepsilonRII/CD23 on B cell membrane promotes its proteolytic cleavage. Evidence for an effect on the oligomer/monomer equilibrium

In the present study we have compared the binding of two monoclonal antibodies to CD23, EBVCS1 and mAb25, which recognize the stalk and the lectin domain, respectively, on the CD23 molecule. At 4 degreesC, EBVCS1 binds to about 10% of the receptors recognized by mAb25 on the B cell surface. At 37 degreesC, whereas mAb25 reaches its maximal binding within a few seconds, EBVCS1 requires 60 min to bind to the same extent. Stabilization of the oligomeric structure of CD23 with IgE strongly affects in a dose-dependent fashion the number of binding sites seen by EBVCS1 but not the t1/2 to reach them, suggesting that EBVCS1 binds to the coiled coil region through an allosteric mechanism. EBVCS1 rapidly down-modulates the membrane CD23 expression with a coincident increase of CD23-soluble fragments in the culture medium, an effect that is inhibited by IgE. In contrast, mAb25, as well as IgE, protects CD23 from proteolytic cleavage and stimulates its endocytosis. These results suggest that EBVCS1 unravels the coiled coil structure of CD23, rendering it more susceptible to proteolytic attack. This supports the oligomeric model proposed previously (Gould, H., Sutton, B., Edmeades, R., and Beavil, A. (1991) Monogr. Allergy 29, 28-49). The biological significance of these observations is discussed.     

Cellular vaccines

This project is devoted to the development of novel cellular vaccines designed to treat cancer patients. These cellular vaccines present and enhance immunogens, which will elicit a potent immune response. The goal is to achieve safe and effective immune reaction against the patient's own tumour. (1) Autologous cellular vaccines are prepared by processing circulating blood mononuclear cells outside of the patient's body (ex vivo) to differentiate them into antigen-presenting cells (APCs). Monocyte-derived APCs (MD-APCs) are then grown in the presence of exogenous target antigens (tumour cell debris, or apoptotic bodies) to become fully mature APCs. (2) Functionality for antigen presentation to T cells of ex vivo MD-APCs is evaluated in vivo. (3) Cellular vaccines are tested in selected rodent animal models. Efficiency and immune response are monitored in pertinent experimental systems for cancer. Pharmacological data are generated for clinical investigation. Tolerance and biologic effects are documented in primates. (4) The first clinical trials on cancer patients are taking place in 1998 on melanoma and prostate cancer to validate the concept. Specialized cell processors with dedicated software and standardized controls are being developed and used for the preparation of cellular vaccines. (5) The evaluation of new non-viral vectors and the validation of new non-viral transfection methods of mononuclear cells with marker genes is in progress and will lead to the ex vivo transfection of genes coding for immunostimulating cytokines or for tumour antigens in MD-APCs. Efficiency will be validated in vitro and in animal models. The ex vivo and animal model studies validate the clinical relevance of this new cellular immunotechnology. Clinical validation of individual autologous cellular vaccines in specific indications for which no treatment is presently available will allow the development of cellular and gene immunotherapy for other types of cancers.