Comparison of MultiMap and TSP/CONCORDE for constructing radiation hybrid maps

Radiation hybrid (RH) map construction allows investigators to locate both type I and type II markers on a given genome map. The process is composed of two steps. The first consists of determining the pattern distribution of a set of markers within the different cell lines of an RH panel. This is mainly done by polymerase chain reaction (PCR) amplification and gel electrophoresis, and results in a series of numbers indicating the presence or the absence of each marker in each cell line. The second step consists of a comparison of these numbers, using various algorithms, to group and then order markers. Because different algorithms may provide (slightly) different orders, we have compared the merits of the MultiMap and TSP/CONCORDE packages using a data set of information currently under analysis for construction of the canine genome RH map.

Effects of space food bar feeding on bone mass and metabolism in normal and unloaded rats

During spaceflights in the shuttle, rats are provided specific food bars. To determine whether this diet allows normal body and skeletal growth, we used four groups of rats fed either standard pellet food or space food bars during a 2-wk unloading experiment. We recorded food intake, body weight, tibial bone mass, and mineral content by ash analyses, cancellous bone volume, and cell activities by histomorphometry. We found that food intake was not different when comparing the two types of food, but that suspended animals had a lower food intake than normal loaded animals. Body weight and bone mass were found lower in suspended animals than in normal loaded animals. Finally, longitudinal growth rate, cancellous bone volume, and bone formation rate were lower in suspended animals, irrespective of the type of food. These results show that space food bar feeding did not affect normal body and skeletal growth, and that body and bone changes due to unloading were not significantly different in animals fed space food bars and standard food.

SHV-16, a beta-lactamase with a pentapeptide duplication in the omega loop

A clinical isolate of Klebsiella pneumoniae was found to be resistant to ampicillin (MIC of 128 microg/ml), ticarcillin (MIC of 512 microg/ml), and ceftazidime (MIC of 128 microg/ml) and susceptible to all other beta-lactams; a synergistic effect between clavulanate and ceftazidime suggested the presence of an extended-spectrum beta-lactamase (ESBL). Transconjugants in Escherichia coli were obtained at low levels (10(-7) per donor cell) and exhibited a similar beta-lactam resistance pattern (resistant to ampicillin, ticarcillin, and ceftazidime at 64 microg/ml). The ESBL, pI 7.6, was encoded by a large plasmid (>100 kb) which did not carry any other resistance determinant. The ESBL-encoding gene was amplified by PCR using bla(SHV)-specific primers and was sequenced. The deduced amino acid sequence of the SHV-16 ESBL showed that it differed from SHV-1 by only a pentapeptide insertion (163DRWET167) corresponding to a tandem duplication in the omega loop. The implication of the 163a-DRWET163b-DRWET sequence in ceftazidime resistance was confirmed by cloning either bla(SHV-1) or bla(SHV-16) in the same vector, subsequently introduced in the same E. coli strain. Under these isogenic conditions, SHV-16 conferred a 32-fold increase in ceftazidime MIC compared to that with SHV-1. Furthermore, site-directed mutagenesis experiments modifying either E166aA or E166bA revealed that the functional glutamic residue was that located in the first copy of the duplicated sequence. But surprisingly, the second E166b also conferred a low-level resistance to ceftazidime. This work is the first description of a class A enzyme exhibiting an extended substrate specificity due to an insertion instead of a nucleotide substitution(s) in a clinical isolate.

Nosocomial outbreak due to a multiresistant strain of Pseudomonas aeruginosa P12: efficacy of cefepime-amikacin therapy and analysis of beta-lactam resistance

Over a 3-year period, 67 patients of the Hospital of Pau (Pau, France), including 64 patients hospitalized in the adult intensive care unit (ICU), were colonized and/or infected by strains of Pseudomonas aeruginosa P12, resistant to all potentially active antibiotics except colistin. Most patients were mechanically ventilated and presented respiratory tract infections. Since cefepime and amikacin were the least inactive antibiotics by MIC determination, all ICU patients were treated with this combination, and most of them benefited. Cefepime-amikacin was found highly synergistic in vitro. Ribotyping and arbitrary primer-PCR analysis confirmed the presence of a single clonal isolate. Isoelectrofocusing revealed that the epidemic strain produced large amounts of the chromosomal cephalosporinase and an additional enzyme with a pI of 5.7, corresponding to PSE-1, as demonstrated by PCR and sequencing. Outer membrane protein profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the absence of a ca. 46-kDa protein, likely to be OprD, and increased production of two ca. 49- and 50-kDa proteins, consistent with the outer membrane components of the efflux systems, MexAB-OprM and MexEF-OprN. Thus, we report here a nosocomial outbreak due to multiresistant P. aeruginosa P12 exhibiting at least four mechanisms of beta-lactam resistance, i.e., production of the penicillinase PSE-1, overproduction of the chromosomal cephalosporinase, loss of OprD, and overexpression of efflux systems, associated with a better activity of cefepime than ceftazidime.

[Antibiotic resistance of Staphylococcus aureus in urban experience: 6 month study in Aquitaine]

Antibiotic resistance of Staphylococcus aureus has been surveyed by eight city laboratories of the Aquitaine area, during a six month-period (january to june 1998). Antibiotic susceptibility testing has been performed by the disk diffusion method, and the results have been collected and analysed using the SIRscan system. After elimination of the redundant strains, a total of 747 isolates has been retained. They were mainly isolated from pus (64%) collected from patients of the community (40%) or hospitalized in 30 private clinics or nursing homes. The percentages of resistant strains (community/institutions) were: benzylpenicillin: 90% (87/92%), oxacillin: 39% (23/50%), kanamycin: 37% (22/47%); gentamicin: 13% (8/16%), tobramycin: 37% (21/47%), amikacin: 21% (13/27%); netilmicin: 6% (5/7%), erythromycin: 33% (30/35%), spiramycin: 72% (77/69%), lincomycin: 24% (17/29%), pristinamycin: 2% (1/2%), tetracycline: 17% (14/19%); pefloxacin: 40% (25/50%), fosfomycin: 9% (6/12%), rifampicin: 10% (7/13%), fusidic acid: 14% (11/15%), cotrimoxazole and vancomycin: 0%. Meticillin-susceptible strains of S. aureus were mostly sensitive to other antibiotics (< or = 6% resistant strains, except for erythromycin: 22%). Among meticillin-resistant S. aureus, heterogeneous strains with a KT phenotype, and various resistance patterns to the remaining antibiotics were predominant (61%), compared to the homogeneous strains with a KTG phenotype and multiresistant to the other antibiotics (32%). The frequencies of resistant strains were highly variable depending on the specimen, the laboratory and the health care institution, except for cotrimoxazole and vancomycin which were always active.

Specific immunotherapy with a standardized latex extract versus placebo in allergic healthcare workers

BACKGROUND

The prevalence of allergy to natural rubber latex proteins has increased over recent years among healthcare professionals but also in children undergoing multiple operations. Exposure to the antigen mainly occurs through the respiratory mucosa and the percutaneous route. Clinical manifestations range from urticaria to angioedema, rhinoconjunctivitis, bronchial asthma, or anaphylactic shock. Preventive measures have been proposed to reduce the risk of sensitization by using only powder-free or synthetic gloves and latex-free material in operating units, but this is not always possible.

OBJECTIVE

The aim of this study was to investigate the efficacy and safety of specific immunotherapy in sensitized workers.

METHODS

Seventeen patients with latex skin allergy and rhinitis (9 of whom also had asthma) were included in this randomized, double-blind, placebo-controlled trial (9 in the active group and 8 in the placebo group) for 1 year. Treatment started with a 2-day course of rush immunotherapy in hospital. Treatment efficacy was assessed after 6 and 12 months by means of symptom and medication scores recorded on diary cards. Conjunctival provocation tests were also performed.

RESULTS

Patients in the active treatment group had a significantly lower total rhinitis score after 6 (P <. 04) and 12 months (P <.05), conjunctivitis score after 6 months (P <. 02), and cutaneous score after 12 months (P <.03) than in the placebo group. Asthma symptoms after 6 or 12 months of treatment were not significantly different between the two groups after adjustment for baseline values. The global medication score was markedly decreased in the latex-treated group. A significant difference in conjunctival reactivity was observed in favor of the active group: the number of patients for whom the threshold dose was increased after 12 months of treatment was significantly greater in the active group than in the placebo group (P <.02). Most injections were well tolerated, but several adverse effects, including hypotension, urticaria, wheezing, and pharyngeal edema, were observed.

CONCLUSION

The clinical benefits observed during the present study included a significant improvement of rhinitis, conjunctivitis, and cutaneous symptoms. Immunotherapy also decreased allergen-specific conjunctival reactivity. Latex-specific immunotherapy may allow sensitized personnel to remain at work, but further trials need to be conducted in a larger number of patients.

Spaceflight inhibits bone formation independent of corticosteroid status in growing rats

Bone formation and structure have been shown repeatedly to be altered after spaceflight. However, it is not known whether these changes are related to a stress-related altered status of the corticosteroid axis. We investigated the role of corticosteroids on spaceflight-induced effects in rat pelvis and thoracic vertebrae. Thirty-six male Sprague-Dawley rats were assigned to a flight, flight control, or vivarium group (n = 12/group). Bilateral adrenalectomy was performed in six rats per group, the additional six rats undergoing sham surgery. Adrenalectomized (ADX) rats were implanted with corticosteroid pellets. On recovery from spaceflight, thoracic vertebrae and the whole pelvis were removed and processed for biochemistry, histomorphometry, or bone cell culture studies. The 17-day spaceflight resulted in decreased bone volume (BV) in the cotyle area of pelvic bones (-12%; p < 0.05) associated with approximately 50% inhibition of bone formation in the cancellous area of pelvic metaphyses and in thoracic vertebral bodies. The latter effect was associated with a decreased number of endosteal bone cells isolated from the bone surface (BS) in these samples (-42%; p < 0.05). This also was associated with a decreased number of alkaline phosphatase positive (ALP+) endosteal bone cells at 2 days and 4 days of culture, indicating decreased osteoblast precursor cell recruitment. Maintaining basal serum corticosterone levels in flight-ADX rats did not counteract the impaired bone formation in vertebral or pelvic bones. Moreover, the decreased ex vivo number of total and ALP+ endosteal bone cells induced by spaceflight occurred independent of endogenous corticosteroid hormone levels. These results indicate that the microgravity-induced inhibition of bone formation and resulting decreased trabecular bone mass in specific areas of weight-bearing skeleton in growing rats occur independently of endogenous glucocorticoid secretion.

Construction and optimization of a dog whole-genome radiation hybrid panel

A dog whole-genome radiation hybrid (WGRH) panel including 126 clones was constructed by fusing dog fibroblasts irradiated at 5000 rads with thymidine kinase-deficient hamster cells. The average retention frequency of the panel designated as RHDF5000 is 21%, and its resolution power is estimated at 600 kb. The data provided by typing 400 markers were used to estimate linkage power changes subsequent to panel reduction. These changes were analyzed by recomputing typing data from five reduced panels. From these simulations, the parameters allowing investigation of the evolution of the linkage power in the course of panel reduction were determined. Guidelines for constructing a WGRH panel are proposed.

[Biology of social phobia]

Until recently, social phobia had not been extensively investigated. Social phobia is a relatively common anxiety disorder and a number of studies reporting efficacy in treatment medication have been reported. Biological studies have used neuroendocrine, naturalistic and chemical challenges, pharmacological probes, neurotransmitter system measures, brain imaging techniques. In summary, these studies provide some neurobiological basis for separating social phobia from others anxiety disorders (specifically panic disorder) and non psychiatric healthy controls.

Expression of inducible nitric oxide synthase during rat brain inflammation: regulation by 1,25-dihydroxyvitamin D3

This study, based on in situ hybridization and immunolabeling experiments, presents the time-course and cellular distribution of inducible NO synthase (iNOS) expression in a rat model of brain inflammation. Both intrahippocampal injection of lipopolysaccharide (LPS) or of buffer (stab lesion) induce an early, transient, and restricted expression of iNOS mRNA and immunoreactivity in the rat CNS. The topographic and phenotypic characteristics of iNOS-producing cells are distinct. After stab lesion, iNOS mRNAs, expressed at 5 h mainly in cells in the interventricular junction and in a few cells in brain parenchyma, were no more detectable from 15 h onwards, whereas the protein was faintly expressed in parenchymal cells at 15 h and 24 h. In contrast, after LPS injection, iNOS-mRNAs were detected from 5 to 24 h. iNOS-immunoreactivity was highly induced and sequentially observed first in choroid plexus and ependymal cells at 5 h, in monocytes and activated/reactive microglia at 15 h and 24 h, and finally in astrocytes at 72 h. In order to investigate potential regulatory effects of 1,25-dihydroxyvitamin D3 (1,25-D3) on iNOS expression, we have delivered this hormone with LPS or buffer into the rat hippocampus. 1,25-D3 significantly inhibits iNOS expression, at both the mRNA and immunoreactive protein levels, 15 h and 24 h after LPS injection, in the cells of the monocyte lineage. Moreover, 72 h after LPS injection, the addition of 1,25-D3 leads to a 6-fold increase in the number of macrophages around the lesion site, that correlates with a decrease in the proportion of apoptotic cells. Since 1,25-D3 can be produced by activated macrophages/microglia and since NO stimulates 1,25-D3 synthesis by macrophages, our results support the hypothesis that this hormone might be synthesized endogenously during CNS inflammatory reactions, thus explaining the transient and restricted iNOS expression observed after LPS intracerebral injection.

TGF-beta2 prevents the impaired chondrocyte proliferation induced by unloading in growth plates of young rats

Growth plate width and cartilage organization are altered during skeletal unloading in growing rats. Immunohistochemical studies have identified TGF-beta in calcified cartilage, and TGF-beta is known to induce mitogenic effects on chondrocytes in vitro. On the other hand, IGF-1 was shown to be expressed in the proximal tibial growth plate and to mediate GH-induced longitudinal bone growth in rats. We therefore investigated the effect of recombinant human (rh) IGF-1 and rhTGF-beta2 infusion on the changes induced by unloading in the cellular organization of the growth plate in growing rats. Hindlimb unloading for 14 days induced a 13% reduction in growth cartilage height in the proximal tibia. This effect was mostly related to a 17% and 14% decrease in the proliferative zone height and chondrocyte number, respectively. In unloaded rats treated with a systemic infusion of rhTGF-beta2 (2microg/kg/day) the number of chondrocytes in the proliferative zone was not different from those of normal loaded animals. In contrast, rhIGF-1 treatment at a 2mg/kg/day dose was not effective in counteracting the effects of unloading on growth plate height and chondrocyte number. These results show that systemic administration of rhTGF-beta2 prevents in large part the reduced growth of chondrocytes in the proliferative zone and the reduced epiphyseal growth plate growth induced by unloading in rats.

Sequencing of the cholesteryl ester transfer protein 5' regulatory region using artificial transposons

We have isolated and sequenced genomic clones encompassing more than 5 kb of the 5' flanking region of the cholesteryl ester transfer protein gene. This region contains multiple Alu repeats, a Mermaid repeat, and an extensive GA repeat, which made sequencing exceedingly difficult. To circumvent the problems that these repeats posed to traditional sequencing methodologies, we employed a novel transposon-facilitated technique, which greatly simplified sequencing of regions that had been difficult to accomplish otherwise. We utilized the artificial transposon, AT-2, a Bluescript derivative containing the dhfr gene and unique primer sites at both ends of the insertion DNA. Integration of the transposon occurred efficiently and covered the entire region of interest. Analysis of the sequence indicates a number of potential regulatory factor binding sites upstream of the previously characterized minimal promoter. The 5.7-kb regulatory region confers significant transcriptional activation in a conditionally transformed mouse hepatocyte line as compared to a minimal 137-bp promoter fragment. In addition, a tetranucleotide repeat of variable length that may provide a useful genetic marker has been identified 2 kb upstream of the CETP transcriptional start site.

Sequence analysis of two genomic regions containing the KIT and the FMS receptor tyrosine kinase genes

The KIT and FMS tyrosine kinase receptors, which are implicated in the control of cell growth and differentiation, stem through duplications from a common ancestor. We have conducted a detailed structural analysis of the two loci containing the KIT and FMS genes. The sequence of the approximately 90-kb KIT locus reveals the position and size of the 21 introns and of the 5' regulatory region of the KIT gene. The introns and the 3'-untranslated parts of KIT and FMS have been analyzed in parallel. Comparison of the two sequences shows that, while introns of both genes have extensively diverged in size and sequence, this divergence is, at least in part, due to intron expansion through internal duplications, as suggested by the discrete extant analogies. Repetitive elements as well as exon predictions obtained using the GRAIL and GENEFINDER programs are described in detail. These programs led us to identify a novel gene, designated SMF, immediately downstream of FMS, in the opposite orientation. This finding emphasizes the gene-rich characteristic of this genomic region.

The PML and PML/RARalpha domains: from autoimmunity to molecular oncology and from retinoic acid to arsenic

Acute promyelocytic leukemia (APL) is specifically associated to a t(15; 17) translocation which fuses a gene encoding a nuclear receptor for retinoic acid, RARalpha, to a previously unknown gene PML. The PML protein is localized in the nucleus on a specific domain of unknown function (PML nuclear bodies, NB) previously detected with autoimmune sera from patients with primary biliary cirrhosis (PBC). These bodies are nuclear matrix-associated and all of their identified components (PML, Sp100, and NDP52) are sharply upregulated by interferons. We show that autoantibodies against both PML and Sp100 are usually associated in sera with multiple nuclear dot anti-nuclear antibodies and demonstrate that PML is an autoantigen, not only in PBC, but also in other autoimmune diseases. In APL, the PML/RARalpha fusion interferes with both the retinoic acid (RA) response and PML localization on nuclear bodies, but the respective contribution of each defect to leukemogenesis is unclear. RA induces the terminal differentiation of APL blasts, yielding to complete remissions, and corrects the localization of NB antigens. Arsenic trioxide (As2O3) also induces remissions in APL, seemingly through induction of apoptosis. We show that in APL, As2O3 leads to the rapid reformation of PML bodies. Thus, both agents correct the defect in NB antigen localization, stressing the role of nuclear bodies in the pathogenesis of APL.

Effects of spaceflight and recovery on rat humeri and vertebrae: histological and cell culture studies

Skeletal changes associated with spaceflight in the rat have been well documented, but few data are available on bone tissue and bone cell metabolism after subsequent on-Earth recovery. We therefore investigated the effects of microgravity and subsequent recovery on trabecular bone morphology and cellular activities in rat humeri and thoracic vertebrae and compared histomorphometric parameters in caudal vertebrae with the behavior of vertebral osteoblastic cells in culture. We report here that humeral weight showed normal growth during the experiment but was unaffected by spaceflight or recovery from spaceflight. However, the 14-day spaceflight resulted in inhibition of static indexes of bone formation in humeral proximal metaphyses and thoracic vertebral bodies. This was associated with a decrease in bone volume in humeral metaphyses. After 14 days of on-Earth recovery, osteoblastic and osteoid surfaces returned toward normal and bone volume was normalized in humeri, whereas the static bone formation parameters were not restored in thoracic vertebrae. In addition, histological indexes of bone formation and osteoblastic cell growth in vitro were not affected by spaceflight in caudal vertebrae. This study shows that rat humeri and thoracic and caudal vertebrae exhibit different patterns of response to spaceflight and subsequent on-Earth recovery, which could be due, at least in part, to the different loading pattern of these bones, and also to differences in bone turnover rate.

Hypervariable microsatellites provide a general source of polymorphic DNA markers for the chloroplast genome

BACKGROUND

The study of plant populations is greatly facilitated by the deployment of chloroplast DNA markers. Asymmetric inheritance, lower effective population sizes and perceived lower mutation rates indicate that the chloroplast genome may have different patterns of genetic diversity compared to nuclear genomes. Convenient assays that would allow intraspecific chloroplast variability to be detected are required.

RESULTS

Eukaryote nuclear genomes contain ubiquitous simple sequence repeat (microsatellite) loci that are highly polymorphic in length; these polymorphisms can be rapidly typed by the polymerase chain reaction (PCR). Using primers flanking simple mononucleotide repeat motifs in the chloroplast DNA of annual and perennial soybean species, we demonstrate that microsatellites in the chloroplast genome also exhibit length variation, and that this polymorphism is due to changes in the repeat region. Furthermore, we have observed a nonrandom geographic distribution of variations at these loci, and have examined the number and location of such repeats within the chloroplast genomes of other species.

CONCLUSIONS

PCR-based analysis of mononucleotide repeats may be used to detect both intraspecific and interspecific variability in the chloroplast genomes of seed plants. The analysis of polymorphic microsatellites thus provides an important experimental tool to examine a range of issues in plant genetics.

Tumor necrosis factor alpha (TNF alpha) downregulates c-kit proto-oncogene product expression in normal and acute myeloid leukemia CD34+ cells via p55 TNF alpha receptors

Tumor necrosis factor alpha (TNF alpha), as a modulator of hematopoiesis, interacts with many growth factor receptors, such as interleukin-3, granulocyte-macrophage colony-stimulating factor (CSF), and granulocyte-CSF receptors. Here, we studied the interactions between TNF alpha and the stem cell factor (SCF) receptor, c-kit, in normal CD34+ hematopoietic progenitors and their leukemic counterpart, ie, acute myeloid leukemic (AML) CD34+ cells coexpressing c-kit antigen. The results showed that (1) incubation of normal bone marrow mononuclear cells with 200 U/mL rhTNF alpha for 20 hours induced a diminution of 31.2% +/- 5.2% of CD34+ cells coexpressing c-kit; (2) the same decrease was observed using purified CD34+ cells and, furthermore, their proliferative response to SCF was inhibited by 31.5% +/- 7.3% after exposure to TNF alpha; (3) similar experiments performed on CD34+ c-kit+ AML cells from 11 patients gave comparable results. Further analysis at the mRNA level indicated that TNF alpha decreased c-kit mRNA transcripts. Moreover, using monoclonal antibodies against the two types of TNF alpha receptors, p75 and p55, we showed that the downregulation of c-kit proto-oncogene product by TNF alpha, on normal and leukemic CD34+ cells, was exclusively mediated by the TNF alpha p55 receptor. Therefore, we conclude that TNF alpha acts as a downregulator of the SCF receptor expression.

Immunological disorders in C virus chronic active hepatitis: a prospective case-control study

Hepatitis C virus-related chronic hepatitis may be associated with various immunological disorders. The aim of this study was to determine prospectively the prevalence of the clinical, biochemical and pathological immunological abnormalities in a series of 61 consecutive patients with chronic hepatitis C, compared with those in 61 age- and sex-matched control subjects without markers of hepatitis C virus and hepatitis B virus infections and with those in 61 patients with chronic hepatitis B. The following investigations were systematically performed before any treatment: detection of serum cryoglobulinemia and rheumatoid factor, detection of a large variety of serum anti-tissue antibodies, biopsy of labial salivary glands, ophthalmological examination, dosage of thyroid-stimulating hormone and in vivo capillary microscopy. Cryoglobulinemia was found in 36% of the hepatitis C virus patients, four of whom had dermatological and/or neurological manifestations of vasculitis, and rheumatoid factor was present in 70%. Serum anti-tissue antibodies were detected in 41% of cases, mostly antinuclear and anti-smooth muscle antibodies. Liver-kidney microsomal and antithyroid antibodies were rare. Salivary gland lesions were found in 49% of the patients: all had lymphocytic capillaritis, sometimes associated with lymphocytic sialadenitis resembling that of Sjögren's syndrome, but without features of sicca syndrome and Ro/SSA antibodies. Five percent of the patients had lichen planus. The prevalences of cryoglobulinemia, rheumatoid factor and anti-tissue antibodies were significantly higher than those in the control group and patients with chronic hepatitis B.(ABSTRACT TRUNCATED AT 250 WORDS)

Lichen planus and hepatitis C virus--related chronic active hepatitis

BACKGROUND AND DESIGN

An increased prevalence of chronic liver disease has been reported in patients with lichen planus (LP). We report six cases of LP associated with chronic active hepatitis and actively replicating hepatitis C virus (HCV).

RESULTS

We studied six patients (three men and three women; mean age, 61 years; age range, 47 to 70 years) with various forms (cutaneous and/or mucosal) of LP and abnormal liver test results. Four patients had severe mucosal lesions. Cutaneous and mucosal lesions had a long-term evolution. Liver disease was discovered 2 to 6 years before LP in three cases and was diagnosed at the same time as LP in the three other cases. Liver biopsy performed in five patients showed chronic active hepatitis without cirrhosis in all five cases. Anti-HCV antibodies were detected in all cases by second-generation enzyme-linked immunosorbent assay and confirmed by second-generation recombinant immunoblot assay. Hepatitis C virus RNA was evidenced by means of polymerase chain reaction in the serum samples from the six patients, proving active viral replication.

CONCLUSIONS

Lichen planus may be associated with HCV-related chronic active hepatitis. As interferon treatment may induce viral inactivation in some patients with HCV-related chronic liver disease, a search for HCV infection should be systematically performed in patients with chronic LP.

The expression of cytokine and cytokine receptor genes in long-term bone marrow culture in congenital and acquired bone marrow hypoplasias

A number of cytokines have been shown to have stimulatory activity on multipotent haematopoietic precursors. These include kit ligand (KL), interleukins (IL) 1, 3 and 6 and granulocyte macrophage-colony stimulating factor (GM-CSF). Using reverse transcriptase/polymerase chain reaction method (RT/PCR) we have examined the expression of these cytokines, the c-kit and IL-6 receptors, in long-term bone marrow culture (LTC) adherent layer cells in human bone marrow hypoplasia syndromes. Disorders studied include Fanconi's anaemia (FA, n = 16), idiopathic aplastic anaemia (AA, n = 11), Seckel's syndrome (n = 2), dyskeratosis congenita (n = 2), Shwachman-Diamond syndrome (n = 1), thrombocytopenia with absent radii syndrome (n = 1), acquired amegakaryocytosis (n = 1), paroxysmal nocturnal haemoglobinuria (n = 1) and acquired agranulocytosis (n = 1). IL-6 and GM-CSF expression appeared reduced in most patients with FA, suggesting that impaired production of these cytokines may contribute to the bone marrow failure seen in most patients with FA. In contrast, abundant IL-6 and GM-CSF expression were seen in most patients with AA when compared with the FA group and controls; these may be mediators of a stromal response in this disorder. No obvious differences were seen between the different patients' groups and controls in expression of the other cytokines or cytokine receptors studied.

Effects of glycerol on the growth, adhesion, and cellulolytic activity of rumen cellulolytic bacteria and anaerobic fungi

The effect of glycerol on the growth, adhesion, and cellulolytic activity of two rumen cellulolytic bacterial species, Ruminococcus flavefaciens and Fibrobacter succinogenes subsp. succinogenes, and of an anaerobic fungal species, Neocallimastix frontalis, was studied. At low concentrations (0.1-1%), glycerol had no effect on the growth, adhesion, and cellulolytic activity of the two bacterial species. However, at a concentration of 5%, it greatly inhibited their growth and cellulolytic activity. Glycerol did not affect the adhesion of bacteria to cellulose. The growth and cellulolytic activity of N. frontalis were inhibited by glycerol, increasingly so at higher concentrations. At a concentration of 5%, glycerol totally inhibited the cellulolytic activity of the fungus. Thus, glycerol can be added to animal feed at low concentrations.

Multiple autoepitope presentation for specific detection of antibodies in primary biliary cirrhosis

Antimitochondrial autoantibodies are present in sera from close to 95% of patients with primary biliary cirrhosis. The so-called primary biliary cirrhosis-specific antigen, named M2, was found to be associated with an enzyme complex of the inner mitochondrial membrane and, more precisely, with the E2 component, dihydrolipoamide acetyltransferase, of the pyruvate dehydrogenase complex. We recently established that an immunodominant epitope recognized in direct enzyme-linked immunosorbent assay by primary biliary cirrhosis M2+ sera, but not by non-primary biliary cirrhosis M2+ sera, could be mimicked by a synthetic peptide encompassing residues 167-184 of the E2 component and associated with lipoic acid. This fragment is present in the natural inner lipoyl-binding site of the human enzyme, and the presence of lipoic acid located on lysine 173 was found to be essential to allow IgG antibody binding. In this study we have improved the enzyme-linked immunosorbent assay test based on the synthetic peptide-lipoic acid conjugate by using a multiple antigen peptide system containing eight copies of the peptide as antigen. This approach avoids the use of a peptide conjugated to a carrier protein and was found to be particularly efficient because 23 of 27 primary biliary cirrhosis M2+ sera (85%) could be identified. A multiple antigen peptide without lipoic acid was not recognized by primary biliary cirrhosis antibodies. The peptide used in the multiple antigen peptide construction was a short 13-mer peptide encompassing a highly conserved sequence present in both the outer (residues 40-52) and the inner (residues 167-179) lipoyl-binding sites of the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-liver microsomes autoantibodies and dihydralazine-induced hepatitis: specificity of autoantibodies and inductive capacity of the drug

Anti-liver microsomes (anti-LM) autoantibodies in patients with dihydralazine-induced hepatitis were found to react specifically with cytochrome P4501A2 (P4501A2) but not with P4501A1 expressed in yeast and bacteria. These results were confirmed by immunoinhibition of methoxyresorufin-O-demethylase activity (supported by the P4501A subfamily); anti-LM antibodies more strongly inhibited this activity in yeast expressing P4501A2 than in yeast expressing P4501A1. Anti-LM were shown to be specific to the disease; in three cases, these autoantibodies were present at high titers during disease, whereas the titers decreased upon recovery and became undetectable a few months after recovery. Thus, there exists a time-dependent relationship between the disease and the autoantibodies, which does not prove that the autoantibodies are causative of the hepatitis; they might only be a marker. The inductive capacity of dihydralazine toward P450 was also studied. In rats treated in vivo and in human hepatocytes treated in vitro with dihydralazine, a 2-fold increase in P4501A2- and P4501A-supported monooxygenase activities was found. The levels of the other P450 isoforms tested were unchanged during treatment, both in vivo in rats and in vitro in cultures of human hepatocytes. In human hepatocytes, dihydralazine produced a dose-dependent increase in the level of P4501A up to 0.1 mM; induction of P4501A was less strong at 0.2 mM and disappeared at 0.5 mM. The same treatment did not change the level of P4503A4, taken as control. The strong heterogeneity in the expression of P4501A enzymes in human liver and the capacity of these enzymes for induction by dihydralazine and by other compounds might be predisposing factors in this autoimmune disease.

Multiple nuclear dots antinuclear antibodies are not specific for primary biliary cirrhosis

Multiple nuclear dots antinuclear antibodies display a specific immunofluorescence pattern on HEp-2 cells. They have been reported to be strongly associated with primary biliary cirrhosis, especially when sicca syndrome was present. To determine whether multiple nuclear dots antinuclear antibodies are specific for primary biliary cirrhosis, we studied the clinical, biochemical, immunological and morphological features of 38 patients between December 1983 and September 1990 who had serum multiple nuclear dots antinuclear antibodies detected in an immunology laboratory of a large medical center. Sufficient information was reliable in 36 patients; the group included 31 women and 5 men (mean age = 57.6 +/- 14.5, range = 30 to 87). Fifteen patients (42%) had primary biliary cirrhosis, 5 patients (14%) had type 1 autoimmune chronic active hepatitis, 4 patients (11%) had liver disease of unknown cause and 12 patients (33%) had various immunological disorders but no liver disease. Two of the patients with primary biliary cirrhosis (13%) had clinical sicca syndrome. Our study demonstrates the following: (a) serum multiple nuclear dots antinuclear antibodies are not specific for liver disease because they can be observed in one third of patients with various immunological disorders without liver involvement, and (b) serum multiple nuclear dots antinuclear antibodies are not specific for PBC because they can also be observed in type 1 autoimmune chronic active hepatitis. Our results also suggest that patent sicca syndrome is abnormally present in patients with primary biliary cirrhosis and multiple nuclear dots antinuclear antibodies.

A lipoyl synthetic octadecapeptide of dihydrolipoamide acetyltransferase specifically recognized by anti-M2 autoantibodies in primary biliary cirrhosis

Close to 95% of patients with established clinical, biochemical and histologic features of primary biliary cirrhosis (PBC) possess antimitochondrial M2 antibodies reacting with the E2 component, dihydrolipoamide acetyltransferase, of the pyruvate dehydrogenase complex. We examined the ability of synthetic peptides of E2 to be recognized in ELISA by sera from patients with PBC and autoimmune-related disorders. Sera from 14 PBC M2+ patients, 1 PBC M2- patient, 5 non-PBC M2+ patients, and 6 patients with chronic active hepatitis were studied. Among the seven E2 synthetic peptides tested (namely peptides 87-119, 167-184, 169-202, 267-302, 456-477, 498-513 and 530-543), only peptide 167-184 used as OVA conjugate and prepared with lipoic acid (LA) located on lysine 173 (natural inner lipoyl-binding site) was recognized in direct ELISA by PBC M2+ sera. The conjugated peptide 167-184 LA was not recognized in direct ELISA by non-PBC M2+ sera or by sera from patients with chronic active hepatitis. The free peptide 167-184 LA inhibited the ELISA reaction of PBC antibodies to PDH and totally abolished the typical immunofluorescence reaction of PBC sera on rat kidney, stomach and liver, or human HEp-2 cell substrates. No inhibition of ELISA or immunofluorescence reaction was found with the other E2 fragments including peptide 167-184 without LA. Our results show that the lipoyl moiety forms an integral part of a dominant conformational epitope recognized by PBC sera. Inasmuch as the peptide 167-184 LA was not recognized by non-PBC sera in direct ELISA, it could be used as a valuable probe for PBC diagnosis.

A lipoyl synthetic octadecapeptide of dihydrolipoamide acetyltransferase specifically recognized by anti-M2 autoantibodies in primary biliary cirrhosis

Close to 95% of patients with established clinical, biochemical and histologic features of primary biliary cirrhosis (PBC) possess antimitochondrial M2 antibodies reacting with the E2 component, dihydrolipoamide acetyltransferase, of the pyruvate dehydrogenase complex. We examined the ability of synthetic peptides of E2 to be recognized in ELISA by sera from patients with PBC and autoimmune-related disorders. Sera from 14 PBC M2+ patients, 1 PBC M2- patient, 5 non-PBC M2+ patients, and 6 patients with chronic active hepatitis were studied. Among the seven E2 synthetic peptides tested (namely peptides 87-119, 167-184, 169-202, 267-302, 456-477, 498-513 and 530-543), only peptide 167-184 used as OVA conjugate and prepared with lipoic acid (LA) located on lysine 173 (natural inner lipoyl-binding site) was recognized in direct ELISA by PBC M2+ sera. The conjugated peptide 167-184 LA was not recognized in direct ELISA by non-PBC M2+ sera or by sera from patients with chronic active hepatitis. The free peptide 167-184 LA inhibited the ELISA reaction of PBC antibodies to PDH and totally abolished the typical immunofluorescence reaction of PBC sera on rat kidney, stomach and liver, or human HEp-2 cell substrates. No inhibition of ELISA or immunofluorescence reaction was found with the other E2 fragments including peptide 167-184 without LA. Our results show that the lipoyl moiety forms an integral part of a dominant conformational epitope recognized by PBC sera. Inasmuch as the peptide 167-184 LA was not recognized by non-PBC sera in direct ELISA, it could be used as a valuable probe for PBC diagnosis.

Digestive permeability to different-sized molecules and to sodium cromoglycate in food allergy

Intestinal absorption of mannitol (used as a marker of normal monomer passage) and intestinal absorption of lactulose (used as a marker of macromolecule exclusion) were measured in 15 healthy subjects and in 20 patients with food allergy. When studied in the fasting state, there was no apparent difference in the absorption of mannitol between control subjects and allergic patients although the absorption of lactulose was more marked, but not significantly, in the latter group. Ingestion of an allergen by these patients led to a significant increase in the absorption of lactulose (intestinal passage increased by a factor of two). Administration of 300 mg cromoglycate 1/4 hour before the provocation test completely averted abnormal intestinal permeability. Digestive absorption of cromoglycate was also studied in the same 15 control subjects and 20 allergic patients. The peak plasma concentration and area under the curve were significantly greater in healthy subjects when the study was carried out in the fasting state. The application of an oral provocation test with an allergen also significantly increased the plasma concentration of cromoglycate in allergic patients. Contact between an allergen and the digestive tract in allergic patients therefore leads to an increased intestinal absorption of macromolecules but also to cromoglycate passage, which inhibits allergic reactions.

Comparison between lactulose-mannitol test and 51Cr-labelled ethylene diamine tetra-acetate test in inflammatory bowel diseases

A direct comparison was made between mannitol-lactulose and EDTA tests in 10 control subjects and in 9 and 19 patients suffering, respectively, from ulcerative colitis or Crohn's disease. The markers were orally administered in a random order and urinary recoveries were measured. At group level, significant differences were only observed in EDTA test results between control subjects and Crohn's disease patients. At the individual level, these tests exhibited poor sensitivity in ulcerative colitis, both in the inactive and active forms of the disease. In contrast, in patients suffering from Crohn's disease, the lactulose and EDTA recoveries and lactulose/mannitol ratios reached interesting figures, particularly in the EDTA 24-hr-test where 63% of the results were abnormal. This percentage climbed to 75% when active forms of the disease were selected. More interestingly, addition of abnormal results obtained with sugar and/or EDTA tests provided a significant increase in sensitivity with figures up to 90% in the entire group and 92% in patients with active forms of the disease. It is suggested that a) Neither the lactulose-mannitol test nor the EDTA test is useful in ulcerative colitis even in the active forms, b) in Crohn's disease, the sensitivity of the EDTA test is greater than that of the sugar test, c) a combination, in the same patient, of the EDTA and sugar tests is able to provide an interesting percentage of sensitivity.

Microscopic Wegener's disease: a particular form of Wegener's granulomatosis

We describe a case of Wegener's granulomatosis in which the disease was manifested with crescentic glomerulonephritis, upper airway ulcerations, and microangiopathic hemolytic anemia with consumptive coagulopathy. No granuloma was identified but antibodies to cytoplasmic components of neutrophils were strongly positive with a diffuse pattern. Because microscopic vessels were predominantly involved (capillaritis), and granuloma were absent, were refer to this particular form of the disease as "microscopic Wegener's disease."

Antinuclear antibodies directed to a 200-kilodalton polypeptide of the nuclear envelope in primary biliary cirrhosis. A clinical and immunological study of a series of 150 patients with primary biliary cirrhosis

Antinuclear antibodies giving a perinuclear fluorescence and directed to a 200-kilodalton polypeptide of the nuclear envelope have been described in primary biliary cirrhosis. The purpose of this study, based on a series of 150 patients with primary biliary cirrhosis, was to ascertain the prevalence of these antibodies and to compare patients with and without these antibodies. Antinuclear antibodies giving a perinuclear fluorescence were demonstrated in 43 of the 150 patients (29%); antibodies directed to the 200-kilodalton polypeptide of the nuclear envelope were found in 40 of these 43 patients. Asthenia, arthralgia, associated extrahepatic diseases, Raynaud's phenomenon, and other antinuclear specificities were significantly less common, and titers of antimitochondrial antibodies were significantly lower in patients with antibodies directed to the 200-kilodalton polypeptide of the nuclear envelope than in patients without these antibodies. Clinical outcome, liver tests, and histological lesions did not significantly differ in patients with and without these antibodies.

[Benign hypertrophic gastritis associated with cytomegalovirus infection]

A new case of benign hypertrophic gastritis associated with cytomegalovirus infection in a 7 year-old boy is reported. The main symptoms were complete digestive intolerance and protein loss, resulting in major hypoalbuminemia and anasarca. The alpha-1-antitrypsin clearance was very increased. Diagnosis was established by upper gastrointestinal x-rays which displayed important thickening of the gastric rugae, and by endoscopic examination with biopsy. A cytomegalovirus infection attested by seroconversion and viruria probably played a role in its origin. Symptomatic treatment and albumin infusions led to recovery within one month. In the last 25 years, 31 cases of benign hypertrophic gastritis have been reported. Vomiting is the main symptom with abdominal pain and G-I bleeding. The protein loss is constant, often severe. In most cases, the disease recedes within a few weeks, unlike the adults' Ménétrier disease which proves to be chronic and severe. The cause remains unknown. In 11 cases, a cytomegalovirus infection was reported and, so, is probably not fortuitous.

A 116,000 Mr nucleolar antigen specific for the dense fibrillar component of the nucleoli

In ATT, a human autoimmune serum, we found anti-nucleolar antibodies that recognized nucleolar antigens confined to a single nucleolar compartment, the dense fibrillar component (DFC). We localized these antigens by immunoelectron microscopy in DFC of HeLa cell nucleoli both on Lowicryl sections and cryoultrathin sections without embedding. The antigens were solubilized by incubation with 2M NaCl but not by RNase or DNase treatment. The ATT serum crossreacted with rat liver nucleoli and PtK1 cell nucleoli in which immunofluorescence labelling displayed a clumpy pattern. During mitosis, the antigens dispersed in the cytoplasm until late telophase, when they gathered in the prenucleolar bodies. In human peripheral lymphocytes, or HeLa cells treated with actinomycin D, the antigens were still present but the fluorescence intensity decreased. By immunoblotting using human nuclear extracts, the ATT serum bound to a 116,000 Mr protein at dilutions up to 1:2000. The reactivity of this band diminished with actinomycin D-treated nuclear extracts. Two minor bands were also observed at 97 and 70K (K = 10(3) Mr). Immunopurification by competition or elution demonstrated that the 116K antigens were at the origin of the nucleolar labelling. This DFC marker appeared to be different from the NOR-silver-stained proteins, which in our preparations exhibited apparent molecular weights of 105, 80 and 38–40K. In addition, these 116K antigens did not exhibit the characteristics described for DNA topoisomerase I, fibrillarin or nucleolin. We propose the 116K antigen as a new marker of the DFC of the nucleoli.

Molecular analysis of glycophorin A and B gene structure and expression in homozygous Miltenberger class V (Mi. V) human erythrocytes

In the Miltenberger class V (Mi. V) condition, red cells lack glycophorin A (GPA) and glycophorin B (GPB) but carry instead an unusual glycoprotein thought to be a hybrid molecule produced by the unequal crossing-over between the closely linked genes encoding for GPA and GPB. By Western blot analysis with rabbit anti-GPA antibodies specific for discrete domains of GPA, it was found that the Mi. V glycoprotein (donor F. M.) contains approximately 60 amino acid residues of GPA at its N-terminus. As a preliminary approach to the molecular analysis of this variant the restriction maps of the GPA and GPB genes were established by Southern blot analysis of genomic DNA and from genomic clones isolated from a human leukocyte library constructed in lambda EMBL4. The GPA and GPB genes cover about 30 kb of DNA and are organized into seven exons (A-1-A-7) and five exons (B-1-B-5), respectively. In addition to the normal genes, a third gene (named inv), closely resembling the GPA and GPB genes, was also identified. In the homozygous Mi. V individual the normal GPA and GPB genes were absent, but an unusual form of gene structure was detected by Southern blot analysis. The Mi. V glycoprotein gene was composed of exon B-1 of the GPB gene followed by exons A-2 and A-3 of the GPA gene and the exons B-3, B-4 and B-5 of the GPB gene. Exon B-1 can be distinguished from exon A-1 of GPA since it is located within a different restriction fragment, but both encode the same amino acid sequence (N-terminal region of the signal peptides). Using the polymerase chain reaction, the junction between exon A-3 and exon B-3 was confirmed by amplification of the DNA region where the putative crossing-over has occurred and it was deduced that the Mi. V glycoprotein is a hybrid molecule composed of amino acid residues 1-58 from GPA fused to amino acid residues 27-72 of GPB. In addition, the finding that part of the signal peptide and the 5'-untranslated region are derived from GPB suggests that the genetic background of the Mi. V variant is rather complex and may involve a cascade of recombination or gene conversion events.

Lymphocytic gastritis versus varioliform gastritis. A historical series revisited

A historical series of varioliform gastritis published in 1978 by Lambert et al. (Digestion 1978; 17: 159-167) was revisited by two pathologists. The histological preparations from 35 patients were reread and interpreted in the light of endoscopic data found in the files. The results demonstrate a strict correlation between clinical diffuse varioliform gastritis and a recently recognized histopathological entity--lymphocytic gastritis, which is characterized by intense lymphocytic infiltration of the surface and foveolar epithelium. The rare discrepancies occur in Crohn's disease and in varioliform gastritis limited to part of the stomach, mostly the antrum.

Influence of hyperlipidic food on the kinetics of slow-release formulations of theophylline

A cross-over study of kinetics has been undertaken in 12 healthy adults volunteers using two sustained-release theophylline products that allow once a day dosing (Theo-Dur tablets and Dilatrane A.P. bead filled capsules) to compare the i.v. pharmacokinetic profiles when taken with an hyperlipidic meal and a balanced standard meal. Each subject took part in four phases in randomised order, corresponding to all possible combinations of the products and the types of meal. Each phase involved a single dose of 9 to 11 mg.kg-1 theophylline administered at 20.00 h, at the beginning of the meal, with 100 ml water. The two formulations were found to be bioequivalent with both types of meal. Taken with a balanced meal, the mean parameters were similar; for Theo-Dur and Dilatrane A.P. they were respectively: Cmax: 11.32 mg.l-1 which plateaued from 8 to 10 h after dosing and 10.9 mg.l-1, which plateaued after 6 to 10 h; AUC 230 mg.h.l-1 and 220 mg.h.l-1; and MRT 18.2 h and 17.7 h. After the hyperlipidic meal the values for Theo-Dur and Dilatrane A.P. respectively, were: Cmax 10.9 mg.l-1 at 12 h and 11.3 mg.l-1 at 10 h; AUC 237 mg.h.l-1 and 227 mg.h.l-1; and MRT 19.2 h and 18.9 h. In spite of a decrease in the absorption rate, which led to a shift to the right of about 2 h of the plasma concentration-time curve, the bioavailability of both formulations were not significantly modified by a hyperlipidic meal as compared to a balanced meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies to 200 kD polypeptide(s) of the nuclear envelope: a new serologic marker of primary biliary cirrhosis

Fifty sera which gave ring-like nuclear staining in immunofluorescence on rat liver tissue sections were characterized. Using immunoprecipitation and Western blotting we showed that 10 of the sera contained antibodies to 200 kD polypeptide(s) of nuclear envelope. Clinical and biological data were available for nine of the patients. Strikingly, all of these patients suffered from primary biliary cirrhosis with eight of them having anti-mitochondrial antibodies. As no control serum displayed such a reactivity, anti-200 kD polypeptide(s) antibodies can be considered as a new marker specific of a subset of primary biliary cirrhosis, being present even when anti-mitochondrial antibodies are absent. The exact identity of the target remains to be established, since several polypeptides of similar molecular weight have been reported to belong to the nuclear envelope.

Antinuclear autoantibodies specific for lamins. Characterization and clinical significance

In 11 patients, sera displaying a ringlike nuclear immunofluorescent staining on sections of rat liver tissue were shown by Western blotting to contain antibodies to lamins. Sera from 8 patients contained autoantibodies reacting with lamin B, whereas sera from the other 3 patients reacted with lamins A and C. All patients (9 women and 2 men) had a chronic autoimmune disorder, which rarely fulfilled the usual criteria for a diagnosis of systemic lupus erythematosus. The disorder was characterized by acute or chronic (active or granulomatous) hepatitis; steroid-responsive blood cytopenia, often associated with a circulating anticoagulant, or anticardiolipin antibodies, or both; and cutaneous leukocytoclastic angiitis or probable brain vasculitis. Eight patients had at least two of these three conditions. Antilamin autoantibodies may thus be a marker for an unusual subset of autoimmune diseases.

Localization of the human c-kit protooncogene on the q11-q12 region of chromosome 4

Using a 166-nucleotide-long DNA synthetic probe corresponding to the v-kit sequence (1458-1623), we have mapped the human c-kit gene to chromosome 4 at the q11-q12 band by in situ hybridization on chromosomes from human lymphocyte preparations.

Assessment of the lactulose-mannitol test in Crohn's disease

The mannitol-lactulose intestinal permeability test was evaluated in 100 healthy controls and 47 patients with Crohn's disease. These patients were further separated into three subgroups of increased activity (Harvey-Bradshaw index) and in two subgroups, with elective colonic lesions and associated ileal and colonic lesions. Results were given as percentages of urinary recoveries for mannitol (M), lactulose (L), and L/M ratio. As a whole, patients with Crohn's disease have lower mean M and higher mean L and mean L/M ratios than controls. The magnitude of alterations in M, L, and L/M increased with activity. The sensitivity of the test, however, reached interesting figures (67%:L and 86%:L/M) only in subgroup III which was composed of relapsing patients. Mean M was lower in patients with associated ileal lesion but, whatever the criterion (M, L, or L/M), the test does not provide any clue for the detection of a possible infraclinical associated ileal localisation.

Measurement of intestinal permeability to mannitol and lactulose as a means of diagnosing food allergy and evaluating therapeutic effectiveness of disodium cromoglycate

Gastrointestinal permeability was evaluated in 90 fasting healthy subjects and 60 patients with food allergy by oral administration to both groups of 5 g of mannitol, a marker of absorption of small molecules, and 5 g of lactulose, a marker of abnormal absorption of large molecules, and subsequent measurement of urinary excretion of mannitol and lactulose. In healthy subjects, mean 5-hour urinary excretion of mannitol was 14.11% and of lactulose 0.26%. In the fasting state, the 60 patients with food allergy exhibited a mean urinary recovery of mannitol of 13.22%, not significantly different from that in healthy subjects. Mean recovery of lactulose in the patients with food allergy was 0.55%, significantly greater than in the healthy patients. After ingestion of food allergens by the patients, mean mannitol recovery fell to 11.57% and mean recovery of lactulose rose to 1.04%, both values being significantly different from those obtained in the fasting patients. On challenging the patients after they had taken sodium cromoglycate, mean mannitol and lactulose recoveries (13.53% and 0.62%, respectively) were not significantly different from those in fasting patients but were significantly different from those obtained on challenging patients unprotected by sodium cromoglycate. Evaluation of intestinal permeability in this way provides an objective means of diagnosing food allergy and assessing the effectiveness of anti-allergic agents such as sodium cromoglycate.

Immunologic mimicry by a monoclonal antibody of the tricyclic anti-depressants' binding site on muscarinic acetylcholine receptors

Inhibition constants of tricyclic anti-depressants and related drugs determined for a monoclonal anti-nortriptyline antibody were close to those previously calculated with the same compounds for the brain acetylcholine muscarinic receptor. A highly significant correlation was found between these two series of inhibition constants when no correlation existed between the inhibition constants for the antibody and those for other receptors. This suggests that the binding site for tricyclic anti-depressants on the antibody mimics the binding site for these ligands on muscarinic receptors. Although nortriptyline reveals a noncompetitive inhibition of N-methyl-scopolamine binding to muscarinic receptors, muscarinic ligands display weak or no binding to the antibody. These findings indicate that the binding site for tricyclic anti-depressants on the receptor is distinct from that for the muscarinic ligands.

Immunologic mimicry by a monoclonal antibody of the tricyclic anti-depressants' binding site on muscarinic acetylcholine receptors

Inhibition constants of tricyclic anti-depressants and related drugs determined for a monoclonal anti-nortriptyline antibody were close to those previously calculated with the same compounds for the brain acetylcholine muscarinic receptor. A highly significant correlation was found between these two series of inhibition constants when no correlation existed between the inhibition constants for the antibody and those for other receptors. This suggests that the binding site for tricyclic anti-depressants on the antibody mimics the binding site for these ligands on muscarinic receptors. Although nortriptyline reveals a noncompetitive inhibition of N-methyl-scopolamine binding to muscarinic receptors, muscarinic ligands display weak or no binding to the antibody. These findings indicate that the binding site for tricyclic anti-depressants on the receptor is distinct from that for the muscarinic ligands.