Helicobacter pylori eradication using a 7-day regimen of low-dose clarithromycin, lansoprazole and amoxycillin

AIM

To evaluate the efficacy of a 7-day regimen of clarithromycin 250 mg b.d., amoxycillin 1 g b.d., and lansoprazole 30 mg b.d. as a treatment for Helicobacter pylori infection.

METHODS

H. pylori status of dyspeptic patients was assessed by 13C-urea breath test and at endoscopy by histology, culture and rapid urease testing of gastric biopsies. Fifty-one H. pylori-positive patients were treated with the above regimen. H. pylori status was reassessed by 13C-urea breath test not less than 28 days after completing treatment. Adverse events and compliance were evaluated.

RESULTS

On an intention-to-treat basis. H. pylori infection was cured in 77% (95% CI: 65-88%) of patients. Minor side-effects including diarrhoea, nausea and taste disturbance were reported by 64% of patients. Ninety-five per cent of patients consumed > 95% of tablets. Metronidazole resistance was 29% but all cultures were sensitive to amoxycillin and clarithromycin.

CONCLUSION

This 7-day treatment with low-dose clarithromycin was moderately effective in curing H. pylori infection. Although compliance was excellent, there was a high frequency of minor adverse events.

Restriction Analysis of PCR-Amplified Internal Transcribed Spacers of Ribosomal DNA as a Tool for Species Identification in Different Genera of the Order Glomales

A technique combining PCR and restriction fragment length polymorphism analysis was used to generate specific DNA fragment patterns from spore extracts of arbuscular mycorrhizal fungi. With the universal primers ITS1 and ITS4, DNA fragments were amplified from species of Scutellospora and Gigaspora that were approximately 500 bp long. The apparent lengths of the corresponding fragments from Glomus spp. varied between 580 and 600 bp. Within the genus Glomus, the restriction enzymes MboI, HinfI, and TaqI were useful for distinguishing species. Depending on the restriction enzyme used, groups of species with common fragment patterns could be found. Five tropical and subtropical isolates identified as Glomus manihotis and G. clarum could not be distinguished by their restriction patterns, corresponding to the morphological similarity of the spores. The variation of internal transcribed spacer sequences among the Gigaspora species under study was low. Fragment patterns of Scutellospora spp. showed their phylogenetic relationship with Gigaspora and revealed only a slightly higher degree of variation.

Weight changes and serum sodium concentrations after an ultradistance multisport triathlon

OBJECTIVE

This study describes the incidence of hyponatremia and the weight changes during an ultradistance multisport triathlon.

DESIGN

Descriptive research.

SETTING

A 1-day triathlon in which each athlete kayaks 67 km, cycles 148 km, and runs 23.8 km.

PARTICIPANTS

Forty-eight athletes competing in the race were studied.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

All subjects were weighed before the race and on completion of the race. A blood sample for serum sodium was taken at the finish of the race.

RESULTS

The mean weight change over the course of the race was a loss of 2.5 kg (SD +/- 1.7, n = 48), or a mean percentage loss of body weight of 3.1% (SD +/- 2.07). This was highly statistically significant (p < 0.0001) using the Student paired t test. No athletes gained weight, and six athletes maintained their same weight. Only one athlete was hyponatremic (Na = 134 mEq/L). This athlete maintained his weight over the course of the race and he did not seek medical attention. The mean serum sodium concentration at the end of the race was 139.3 mEq/L (SD = 2.28, n = 47). There was a significant correlation (r = 0.30, p = 0.04) between sodium levels and weight change during the race: the greater the weight loss, the higher the serum sodium concentration. There was no significant correlation between the degree of weight loss and athletes' finishing times (r = 0.11, p = 0.45).

CONCLUSIONS

Symptomatic hyponatremia did not occur in the 1996 Coast to Coast multisport triathlon, although one athlete had borderline hyponatremia. Athletes lose significant amounts of weight over the course of this multisport event, but nevertheless manage to complete the race.

Evidence for genetic control of changes in f-actin polymerization caused by pathogenic microorganisms: in vitro assessment using gingival fibroblasts from human twins

Attachment to and migration upon a substratum, as well as other functions of connective tissue cells, are regulated mainly by cytoplasmic structural proteins, particularly filamentous actin (f-actin). Pathogenic microorganisms exert negative effects on cytoskeletal proteins. In the present study, normal gingival fibroblasts from 10 sets of human twins (6 fraternal, DZ; 4 identical, MZ) were exposed to soluble extracts from Porphyromonas gingivalis or Fusobacterium nucleatum, then f-actin was stained using FITC-labeled phalloidin. Cells were examined under fluorescence, and a computer-assisted image analyzer quantitated f-actin polymerization as fluorescence intensity on a per-cell basis. Intraclass correlation coefficients for f-actin in MZ/MZ vis-a-vis DZ/DZ paired cell cultures were determined to assess the possible heritability of responses to the microorganism preparations. F-actin labeling was significantly different between control cultures and those exposed to the extracts. Both F. nucleatum and P. gingivalis effected f-actin and fibroblast morphology. When the data were adjusted for gender and age effects, and for differences in control f-actin levels, fibroblasts from MZ twin pairs were moderately similar in both absolute and relative responses to bacterial challenges; cells from DZ twins showed little similarity when response was measured on the absolute scale, and moderate similarity using the relative scale.

Development of a novel TNF alpha ligand-receptor binding assay for screening NATCHEM Libraries

The TNF alpha receptor is a major therapeutic target since over production of TNF alpha plays a key role in the development of septic shock following bacterial infection and has been implicated in the pathogenesis of many inflammatory disorders such as rheumatoid arthritis. To screen our NATCHEM Libraries for novel natural product inhibitors of this target we have developed a sensitive immobilised TNF alpha receptor binding assay based on a commercially available recombinant soluble TNF alpha receptor (p55) and [125I]-TNF alpha.

Leukaemia inhibitory factor: induction in the early phase of allergic contact dermatitis

It has been suggested that leukaemia inhibitory factor (LIF), may be involved in the pathogenesis of cutaneous inflammation. In 5 patients with previously proven contact allergy to nickel, LIF mRNA and protein expression were assessed by reverse transcription-polymerase chain reaction and immunohistochemistry in 5% nickel sulfate patch test biopsies 24 h after application of the patch. Control specimens were obtained from non-tested and vehicle-tested skin from the same individuals. LIF mRNA expression was significantly increased in nickel-tested skin compared with both vehicle-tested (p = 0.045) and non-tested skin (p = 0.041). All biopsies showed similar patterns of LIF immunoreactivity, with no significant differences between nickel-tested, vehicle-tested and non-tested skin. Immunostaining was cytoplasmic and was present in the epidermis and hair follicles. No dermal staining was observed. This study suggests that LIF may play a role in the early phase of allergic contact dermatitis.

Identification of selected gamma-ray induced deficiencies in zebrafish using multiplex polymerase chain reaction

The ease with which mutations can be generated in zebrafish makes this vertebrate an important resource for developmental genetics and genome studies. We have developed a PCR-based screening method that allows the efficient identification of gamma-ray induced deficiencies targeted to selected sequences. We describe three mutants characteristic of our findings and show that these mutations include deletions and translocations that can affect as much as 1% of the genome. These deficiencies provide a basis for analyzing the functions of cloned zebrafish genes using noncomplementation screens for point mutations induced by high-efficiency chemical mutagenesis.

Oral diseases, mycology and periodontal microbiology of HIV-1-infected women

HIV-1 infection is increasing more rapidly among heterosexual women. Relatively limited information is available on HIV-related oral pathoses in these individuals. To gain insight into the type and occurrence of oral lesions in this population, 25 HIV-1 infected women including asymptomatic, symptomatic and AIDS patients were examined clinically and sampled for detection of oral yeast and characterization of their subgingival microbial flora. Sixty percent of the subjects were African-American, with 80% infected via heterosexual contact. Oral candidiasis was the most common nonperiodontal oral lesion, observed in 44% of the patients. Oral yeast was cultured from all women with candidiasis and 76% of the total subjects. Oral hairy leukoplakia was clinically diagnosed in 16% of the subjects. Clinically mild to moderate gingivitis and periodontitis were observed in 84% and 52% of the patients, respectively. Candidiasis and the presence of cultivable yeast were observed in patients with low, intermediate, and high CD4+ T lymphocyte numbers. Plaque samples were collected from each subject and enumerated by predominant cultivable methods, selective media and microscopy. No differences were detected in the microflora associated with seropositive women with existing periodontitis relative to those without periodontitis or to seronegative women with periodontitis. Candidiasis was the most notable oral clinical manifestation in the HIV-1-infected women and may be a useful clinical indicator of early immune dysfunction mediated by HIV-1.

Inhibition of estrogen-stimulated growth of uterine leiomyomas by selective estrogen receptor modulators

Uterine leiomyoma is the most frequent gynecologic neoplasm in women. By using a panel of cell lines derived from spontaneous Eker rat leiomyomas, we examined the estrogen-responsive phenotype of these tumor cells. Leiomyoma-derived ELT cell lines proliferated in response to estrogen, and estrogen-induced cell proliferation could be inhibited by the estrogen antagonist ICI 182780 and the selective estrogen-receptor modulators (SERMs) raloxifene and tamoxifen. In addition to inhibiting cell growth, these antagonists also inhibited estrogen-induced increases in progesterone-receptor expression. These data indicate that SERMs such as raloxifene and tamoxifen act as estrogen antagonists in uterine myometrial cells and suggest that this class of compounds may be effective for treatment of this important gynecologic neoplasm.

Inflammatory determinants of asthma severity: mediator and cellular changes in bronchoalveolar lavage fluid of patients with severe asthma

Cellular and mediator profiles in bronchoalveolar lavage have not been compared systematically between patients with asthma of different severities, mainly because the patients with more severe asthma have an increased need for antiinflammatory medication. Information is limited to comparisons of allergic and intrinsic asthma, which can be distinguished clinically. When patients from these two groups with similar degrees of bronchial hyperresponsiveness were compared, both groups showed increased numbers of activated T-helper lymphocytes; those in the allergic group expressed the IL-2 receptor (CD25+), whereas in patients with intrinsic asthma there was also an increased number of T-suppressor cells with the activation markers CD25, class II histocompatibility antigen, and very late activation antigen-I, as well as T-helper cells class II histocompatibility antigen and very late activation antigen-I. This pattern is compatible with a more chronic T-cell activation in patients with intrinsic asthma. In patients with allergic asthma the cytokine pattern is compatible with a pure TH2 response (elevated IL-4 and IL-5); however, intrinsic asthma is characterized by elevated IL-5 and IL-2 but not IL-4. Our own findings show similar concentrations of IL-1, IL-8, and granulocyte-macrophage colony-stimulating factor in bronchoalveolar lavage fluid of patients with allergic and intrinsic asthma, whereas IL-6 and interferon-gamma tended to be higher in patients with intrinsic asthma. There are probably fundamental differences in the pathogenesis of allergic and intrinsic asthma. These findings suggest that asthma does not depend on the presence of IgE or IL-4, although both may contribute to the pathogenesis of atopic asthma. The only common pathway in the different presentations of asthma that has been related to clinical symptoms appears to be IL-5-mediated activation of eosinophils; therapies aimed at this mechanism may be promising.

Differential expression of alpha E beta 7 integrins on bronchoalveolar lavage T lymphocyte subsets: regulation by alpha 4 beta 1-integrin crosslinking and TGF-beta

T lymphocytes expressing the alpha E beta 7 integrin are localized and selectively retained in mucosal tissues. To investigate a potential relationship between alpha E beta 7 expression and pulmonary inflammation, the distribution of alpha E beta 7-bearing CD4+ and CD8+ T cells in peripheral blood and bronchoalveolar lavage (BAL) fluids obtained from patients with allergic asthma, sarcoidosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis (IPF) was determined. In contrast to the distribution in peripheral blood, BAL fluid from these patients contained high number of cells expressing alpha E beta 7 with markedly different expression patterns on CD4 or CD8 cells as well as among the various diseases. Despite similar numbers of activated CD4 cells, alpha E beta 7+CD4+ T cells ranged from 15% in asthmatics to 70% in IPF. In contrast, even in normal individuals, 60% to 90% of BAL fluid CD8+ T cells express alpha E beta 7, suggesting differential induction mechanisms on CD4 and CD8 cells. In vitro experiments revealed that a substantial proportion of peripheral blood CD+ T cells express alpha E beta 7 after stimulation with anti-CD3 antibodies, and up to 80% positive cells were found after the addition of TGF-beta. In contrast, less than 10% of CD4 cells express this particular integrin after in vitro stimulation, and the presence of TGF-beta only increased the number to 30%. Supernatants from in vitro-activated BAL cells as well as concentrated BAL fluid from patients with high alpha E beta 7 expression had no further enhancing effect. However, crosslinking of alpha 4 beta 1-, but not beta 2-integrins, significantly increased the number of alpha E beta 7 expressing CD4+ and CD8+ T cells, even in the absence of TGF-beta. These data indicate that in addition to TGF-beta, the interaction of particular T-cell subsets with specific endothelial cell and extracellular matrix proteins may upregulate alpha E beta 7 integrin expression and thereby contribute to the selective accumulation of these cells in inflammatory lung diseases.

Presence of an insulin-like growth factor I autocrine loop predicts uterine fibroid responsiveness to tamoxifen

Uterine leiomyoma is an estrogen-responsive tumor, and the present studies examine the ability of the antiestrogen tamoxifen to modulate leiomyoma cell growth. Tamoxifen is an effective form of hormonal therapy for breast cancer, although the mechanism by which tamoxifen inhibits tumor growth is not well understood and may involve mechanisms other than the action of tamoxifen as an estrogen antagonist. Tamoxifen was found to inhibit the proliferation of three of five leiomyoma-derived cell lines (ELT cell lines) in vitro, including an estrogen receptor-negative cell line. The ability of tamoxifen to decrease leiomyoma growth was found to correlate with expression of insulin-like growth factor I (IGF-I) by the tumor cells, suggesting that the inhibitory effects of tamoxifen were associated with expression of this growth factor. The existence of an IGF-I autocrine loop in the cells was investigated, because transcripts for both IGF-I and its cognate receptor were expressed in the tamoxifen-responsive cell lines. An IGF-I RIA demonstrated secreted IGF-I protein in serum-free medium conditioned by the IGF-I-expressing cell line ELT 3, and this same medium supported the growth of IGF-requiring MCF-10A cells, indicating the presence of biologically active IGF-I in the conditioned medium. Exogenous IGF-I stimulated ELT 3 cell proliferation, confirming that this growth factor is mitogenic for leiomyoma cells. IGF-I neutralizing antibody inhibited ELT 3 growth, indicating that the levels of IGF-I produced by the leiomyoma cells were physiologically significant. These data demonstrate the existence of an IGF-I autocrine loop in tamoxifen-sensitive leiomyoma cells, supporting the hypothesis that the presence of an IGF-I autocrine loop predicts uterine fibroid responsiveness to tamoxifen.

Radiation-induced genomic instability and persisting oxidative stress in primary bone marrow cultures

There is accumulating evidence that cells exposed to low and often environmentally relevant doses of ionizing radiation survive the initial insult, but transmit genomic instability to their progeny. The underlying mechanism of radiation-induced genomic instability is unknown. We present bio-chemical evidence consistent with the hypothesis that enhanced and persistent oxy-radical activity may be responsible.

A longitudinal study of lymphocyte subsets in a cohort of cats naturally-infected with feline immunodeficiency virus

Despite the potential of feline immunodeficiency virus (FIV) as an animal model for human immunodeficiency virus (HIV) studies, the long term effects of naturally-occurring infection have not been determined. HIV infection causes an ongoing deterioration in immune function which directly correlates with disease, in particular acquired immunodeficiency syndrome (AIDS). However, it is not known whether FIV-induced immunosuppression is progressive or related to the clinical condition. This study examined changes in lymphocyte subset numbers of serial samples, taken from cohorts of FIV-positive and FIV-negative cats over and 18-month period. FIV-positive cats were clinically staged as asymptomatic carriers (AC) or cats with AIDS-related complex (ARC), and FIV-negative cats matched and staged on the basis of similar diseases. During the course of the study, 4 FIV-positive cats developed AIDS, classed as the terminal stage of infection. There were no significant differences in the mean absolute numbers of any lymphocyte subset between the onset (t0) and the completion (t18) of the study. Similarly there were no significant changes in subset numbers during the 18 months preceding the development of AIDS. While the study period was brief and the sample sizes small, it is postulated that FIV infection in Australia may not necessarily cause progressive immunodeficiency and that FIV-induced immunosuppression (as measured by subset analysis) may not be well correlated with the clinical status of the infected cat.

True identity of control Staphylococcus aureus strains and their performance in the tube coagulase test

One hundred laboratories were asked to submit their control Staphylococcus aureus strains to determine the true identity of strains presumed to be S. aureus NCTC 6571, and also to evaluate the performance of those strains being used as controls in the tube coagulase test (TCT). Of the 60 who replied, 55 laboratories sent at least one strain labelled as S. aureus NCTC 6571 (total of 64 strains). Of these, 84% were identified as S. aureus, and were indistinguishable from a fresh type strain by a combination of phenotypic methods including biotyping, antibiotic susceptibility testing and phage typing. Six-to-ten strains (9-16%), depending on the degree of stringency, were not identifiable as S. aureus NCTC 6571. The time since last retrieval from storage ranged from daily to > or = 3 years, but there was no correlation between this duration and the likelihood of differing from S. aureus NCTC 6571. Forty-seven laboratories submitted 51 strains used as controls in the TCT; these included 31 strains labelled as S. aureus NCTC 6571, eight wild strains, three other NCTC strains and nine strains of uncertain origin. Generally, the S. aureus NCTC 6571 strains produced weaker clots than the remainder. None of the S. aureus NCTC 6571 strains was found to be inoculum dependent but four of the other control strains were. The study demonstrates that some laboratories must improve procedures for ensuring that control S. aureus strains retain their true identity, particularly by avoiding repeated subcultures. Laboratories are divided in their use of strong or weak (S. aureus NCTC 6571) positive controls for the TCT. S. aureus NCTC 6571 is a more stringent control for the TCT than other control strains presently being used and is, therefore, to be preferred.

The chinless mutation and neural crest cell interactions in zebrafish jaw development

During vertebrate development, neural crest cells are thought to pattern many aspects of head organization, including the segmented skeleton and musculature of the jaw and gills. Here we describe mutations at the gene chinless, chn, that disrupt the skeletal fates of neural crest cells in the head of the zebrafish and their interactions with muscle precursors. chn mutants lack neural-crest-derived cartilage and mesoderm-derived muscles in all seven pharyngeal arches. Fate mapping and gene expression studies demonstrate the presence of both undifferentiated cartilage and muscle precursors in mutants. However, chn blocks differentiation directly in neural crest, and not in mesoderm, as revealed by mosaic analyses. Neural crest cells taken from wild-type donor embryos can form cartilage when transplanted into chn mutant hosts and rescue some of the patterning defects of mutant pharyngeal arches. In these cases, cartilage only forms if neural crest is transplanted at least one hour before its migration, suggesting that interactions occur transiently in early jaw precursors. In contrast, transplanted cells in paraxial mesoderm behave according to the host genotype; mutant cells form jaw muscles in a wild-type environment. These results suggest that chn is required for the development of pharyngeal cartilages from cranial neural crest cells and subsequent crest signals that pattern mesodermally derived myocytes.

Electromagnetic field induced changes in lipid second messengers

Initial studies with a human hematopoietic cell line, TF-1, suggest multifarious effects of electromagnetic fields on lipid signal transduction. We have examined the effects of pulsed magnetic fields (2 T, 84 microseconds zero-to-peak haversine, 91 V/m induced electric field) on the cell cycle by flow cytometry. A 31% increase of cells in the G1 phase occurred concurrently with a 35% decrease of cells in S-phase, which suggests that doses of 30 or 40 pulses have an anti-proliferative effect. Changes in the lipid second messengers, diacylglycerol (DAG) and phosphatidic acid (PA) with stimuli of 2 T intensity were also dependent on the number of pulses. DAG production doubled with 30 pulses and tripled with 40 pulses, and PA levels were reduced to one third and one tenth of the original levels. Phospholipase D (PLD) up-regulation was assessed directly by the capacity of PLD to catalyze transphosphatidylation in the presence of alcohol. [3H]Phosphatidylethanol formed rapidly and continued to increase with concomitant decreases in [3H]PA and parallel generation of [3H]DAG. Propranolol, an inhibitor of PA phosphohydrolase, inhibited the formation of DAG in a dose-dependent manner with a marked increase in PA production. Examination of the kinetics of formation of [3H]choline and [3H]phosphocholine at different times after stimulation showed a rapid and consistent increase in [3H]choline, whereas [3H]phosphocholine increase was evident only 60 min after stimulation. Magnetic exposure also caused a shift in some molecular species patterns of DAG and PA which could be correlated with phosphatidylinositol, phosphatidylethanolamine and phosphatidylcholine molecular species decreases. Therefore, we propose that the PC-PLC pathway may be temporarily inactivated for a short period of time by exposure to pulsed stimuli, and the PC-PLD pathway is up-regulated based on: (1) cellular release of [3H]choline; (2) rapid intracellular formation of [3H]PA followed by [3H]DAG; (3)active transphosphatidylation; and (4) blockade of DAG formation by propranolol.

A Combined Model for Growth and Subsequent Thermal Inactivation of Brochothrix thermosphacta

A mathematical technique for integrating growth and thermal inactivation models of microorganisms into a smooth combined model that can be applied to circumstances under which the temperature gradually rises from growth to inactivation regions is described. For the death part of the model, a correction term is introduced to allow for additional resistance of the cells gained during slow heating. The model was validated with Brochothrix thermosphacta heated in broth at rising temperatures.

Administration of chlorhexidine to persons with mental retardation residing in an institution: patient acceptance and staff compliance

Chlorhexidine is beneficial in maintaining the oral health of persons diagnosed with mental retardation. Proper daily oral administration, however, depends upon the compliance of caregivers as well as patient acceptance. If caregivers are noncompliant or if patients are overly resistant to daily applications of chlorhexidine, its proven benefits will not be realized. This study evaluated two methods of chlorhexidine administration for patient acceptance and direct-care staff compliance among 44 institutionalized individuals diagnosed with mental retardation.