On the halt of spontaneous capillary flows in diverging open channels

Due to their compactness and independence of exterior energy sources, capillary microsystems are increasingly used in many different scientific domains, from biotechnology to medicine and biology, chemistry, energy and space. Obtaining a capillary flow depends on channel geometry and contact angle. A general condition for the establishment of a spontaneous capillary flow in a uniform cross section channel has already been derived from Gibbs free energy. In this work, we consider spontaneous capillary flows (SCF) in diverging open rectangular channels and suspended channels, and we show that they do not flow indefinitely but stop at some location in the channel. In the case of linearly diverging open channels, we derive the expression that determines the location where the flow stops. The theoretical approach is verified by using the Surface Evolver numerical program and is checked by experiments. The approach is extended to sudden enlargements, and it is shown that the enlargements can act as stop and trigger valves.

Concentration of soluble intercellular adhesion molecule-1 in serum samples from patients with endometriosis collected during the luteal phase of the menstrual cycle

BACKGROUND

Soluble intercellular adhesion molecule-1 (sICAM-1), released by endometriotic lesions, is involved in the regulation of cytotoxic processes. Altered levels of sICAM-1 in the circulation could parallel its deregulation in the peritoneal cavity. We therefore investigated whether sICAM-1 could represent a serum marker for endometriosis.

METHODS

sICAM-1 levels were measured by enzyme-linked immunosorbent assay in serum samples from 176 subjects with surgically confirmed endometriosis (134 patients with stage I-II and 42 patients with stage III-IV) and 198 controls with no surgical evidence of the disease. All serum samples were collected during the luteal phase of the menstrual cycle. Detailed information about demographics, symptoms and clinical profile were collected.

RESULTS

Mean levels of sICAM-1 appeared significantly reduced in patients with stage III-IV endometriosis in a crude comparison of means. However, when means were adjusted for potential confounders such as the pre-operative indication or fertility status, no significant difference between cases with stage III-IV disease and controls was observed.

CONCLUSIONS

Serum levels of sICAM-1 during the luteal phase of the cycle are not able to discriminate women suffering from endometriosis from controls when confounders are taken into account. These results underline the importance of careful identification of confounders, based on patients' demographic and clinical data in studies aiming at discovering diagnostic markers for endometriosis.

Large scale validation of human N-myc Downstream-Regulated Gene (NDRG)-1 expression in endometrium during the menstrual cycle

A major challenge in the comprehension of the endometrial transformations leading to the completion of each menstrual cycle in humans is in the identification of specific molecular pathways underlying these monthly turnovers. Towards this goal we compared, by the differential display technique, the relative expression of mRNA in endometrial biopsies harvested in individuals (n = 48) either at the proliferative or the secretory phase of the menstrual cycle. We isolated a cDNA fragment homologous to NDRG1 (N-myc Downstream-Regulated Gene-1) that is present in markedly higher amounts in the secretory phase. Northern blot analysis and quantitative real time PCR experiments confirmed this result in distinct cohorts of individuals (44 and 560 respectively). A closer examination of data showed that the highest mRNA levels were found during the range of 25-28 days of the uterine cycle. Consistent with the mRNA data, the temporal profile of the NDRG1 protein showed a 15-fold increase during the secretory phase, as demonstrated by using semi-quantitative dot blot analyses (n = 92). Immunohistochemical localization revealed that NDRG1 was expressed both in epithelial and stromal cells. This large scale validation of the NDRG1 mRNA and protein increase in endometrium during the secretory phase is consistent with its differentiation-related function described in other tissues and its potential involvement in the window of implantation of the human endometrium, as suggested by previous chip-based evidence.

Levels of vascular endothelial growth factor (VEGF) in serum of patients with endometriosis

BACKGROUND

Elevated concentrations of vascular endothelial growth factor (VEGF) have been detected in the peritoneal fluid of patients with endometriosis. Furthermore, it was postulated that VEGF is involved in the development of endometriotic lesions. The present study is aimed at determining whether high levels of VEGF could also be found in the serum of patients with endometriosis.

METHODS

VEGF levels were measured by enzyme-linked immunosorbent assay (ELISA) in serum from 131 subjects with surgically confirmed endometriosis and 146 controls with no clinical evidence of the disease or detectable endometriotic lesions at the time of surgical examination. Parameters such as demographics, personal habits, menstrual characteristics and clinical profile were collected from each subject included in this study.

RESULTS

The mean VEGF levels were not significantly modulated in serum samples of cases compared with controls in a crude general linear model and in a model adjusted for possible confounders. VEGF serum levels did not correlate with the score, stage of endometriosis or the presence of benign gynaecological disorders. However, a correlation was found between circulating concentrations of VEGF and body mass index.

CONCLUSION

Although VEGF seems to play a pivotal role locally in the implantation and development of endometriotic lesions, the disease is not associated with a significant modulation in the levels of circulating VEGF.

Impaired ability of Cftr knockout mice to control lung infection with Pseudomonas aeruginosa

The present study was aimed at investigating the innate susceptibility of C57BL/6-Cftrunc/Cftrunc knockout [B6-Cftr (-/-)] mice to pulmonary infection with Pseudomonas aeruginosa. Our results indicate that 58.4% of B6-Cftr (-/-) mice died within 6 d following lung infection with 10(5) P. aeruginosa entrapped in agar beads, whereas only 12.1% of B6-Cftr (+/+) mice died over the same period of time. Moreover, the number of bacteria recovered from the lungs of B6-Cftr (-/-) mice 3 and 6 d after infection was significantly higher than that observed in their littermate controls. No correlation was found between the weight or age of the animals and the number of viable bacteria recovered from the lungs of mice. Histopathological examination of lung sections from P. aeruginosa-infected mice revealed that the infection results in a severe bronchopneumonia. Both B6-Cftr (-/-) knockout mice and their littermate controls developed similar lung pathology during the course of infection. Overall, results reported in the present study suggest that a defect at the Cftr locus leads to an exacerbation of P. aeruginosa lung infection resulting in a dramatically increased mortality rate and higher bacterial load.

Lung disease in mice with cystic fibrosis

The leading cause of mortality and morbidity in humans with cystic fibrosis is lung disease. Advances in our understanding of the pathogenesis of the lung disease of cystic fibrosis, as well as development of innovative therapeutic interventions, have been compromised by the lack of a natural animal model. The utility of the CFTR-knockout mouse in studying the pathogenesis of cystic fibrosis has been limited because of their failure, despite the presence of severe intestinal disease, to develop lung disease. Herein, we describe the phenotype of an inbred congenic strain of CFTR-knockout mouse that develops spontaneous and progressive lung disease of early onset. The major features of the lung disease include failure of effective mucociliary transport, postbronchiolar over inflation of alveoli and parenchymal interstitial thickening, with evidence of fibrosis and inflammatory cell recruitment. We speculate that the basis for development of lung disease in the congenic CFTR-knockout mice is their observed lack of a non-CFTR chloride channel normally found in CFTR-knockout mice of mixed genetic background.

Mucociliary clearance in cystic fibrosis knockout mice infected with Pseudomonas aeruginosa

In this study, we examined whether mucociliary clearance differed between cystic fibrosis (CF) knockout mice and wildtype controls. Additionally, we investigated whether infection with Pseudomonas aeruginosa, a common pathogen in the CF lung, affected this important host defence mechanism. Ciliary beat frequency (fcb) and particle transport (PT) were recorded using an in vitro lung explant preparation. Measurements were made from uninfected cystic fibrosis transmembrane conductance regulator (CFTR) knockout (-/-) mice and littermate controls (+/+) and compared to measurements from infected animals. While there were no differences detectable in fcb between CFTR -/- mice and their +/+ controls either in the presence or absence of P. aeruginosa, PT rates were different between these groups; interestingly, PT rates appeared dependent on both CFTR and infection status, with uninfected CFTR +/+ animals demonstrating higher rates of PT than their -/- littermates, while CFTR +/+ P. aeruginosa-infected mice demonstrated lower PT than knockout mice. These data demonstrate differences in mucociliary clearance between cystic fibrosis transmembrane conductance regulator knockout mice and controls, and further that Pseudomonas aeruginosa infection affects mucociliary clearance in the peripheral airways of mice. Additionally, the observed differences in particle transport suggest that cystic fibrosis transmembrane conductance regulator knockout mice demonstrate different mucociliary responses to infection.

Phenotypic characterization of two cell populations involved in the acquisition of suppressor activity by cultured spleen cells from Mycobacterium lepraemurium-infected mice

The impairment of cellular immunity in mice infected with Mycobacterium lepraemurium was shown to correlate with the development of suppressor cells. We have previously reported that before suppressor activity is detectable in freshly harvested cell suspensions, suppressor cell precursors accumulate in the spleen of infected mice. Upon overnight culture in the presence of a regulatory cell subset, these precursor cells acquire the capacity to impair the concanavalin A (Con A)-induced proliferation of normal spleen cells. The purpose of this study was to determine the phenotype of the cells involved in this phenomenon. This was done by following the development of suppressor activity in spleen cell suspensions depleted of defined cell subsets of the adherent or the non-adherent cell fractions with selected MoAbs and immunomagnetic beads or by in vivo treatment. Our results indicate that the acquisition of suppressor activity requires the interaction of Ia+CD11b+Fc gamma R+IgG- asialo GM1- adherent cells with Thy1-CD4-CD8-IgG-Ia- asialo GM1-Fc gamma R+CD11b+ non-adherent cells. It is also shown that the development of suppressor activity is impaired by preventing cell-cell contact between these two cell subsets through coculture in 'Transwell chambers'. These observations support the conclusion that the in vitro acquisition of suppressor activity is a consequence of the maturation of suppressor cell precursors of the monocytic lineage induced by a receptor-ligand type interaction with a non-adherent cell subset that is clearly distinct from mature T, B and natural killer (NK) cells.

Role of tumor necrosis factor alpha in innate resistance to mouse pulmonary infection with Pseudomonas aeruginosa

In the present study, we have investigated the mechanisms underlying mouse resistance to endobronchial infection with Pseudomonas aeruginosa enmeshed in agar beads. This was done by monitoring macrophage activation-associated gene expression in lung and alveolar cells harvested from resistant (BALB/c) and susceptible (DBA/2, C57BL/6, and A/J) strains of mice over the course of infection with P. aeruginosa. Interleukin-1 alpha, interleukin-1 beta, macrophage inflammatory protein-1 alpha, JE, and tumor necrosis factor alpha (TNF-alpha) mRNA expression levels were up-regulated in all strains of mice during the early phase of the infection. The level of TNF-alpha mRNA expression was increased to a greater extent in resistant BALB/c mice than in susceptible DBA/2, C57BL/6, and A/J strains of mice. This observation paralleled a higher secretion of TNF-alpha into the alveolar space of BALB/c mice at 3 and 6 h postinfection. The concentration of TNF-alpha released in alveoli returned to basal levels within 24 h of infection in mice of all strains, even though the TNF-alpha mRNA expression remained high until 3 days after infection. In vivo treatments with either anti-murine TNF-alpha monoclonal antibodies or with aminoguanidine significantly increased the number of P. aeruginosa bacteria detected in the lungs of resistant mice at 3 days postinfection. Overall, these findings indicate that both TNF-alpha and nitric oxide exert a protective role in response to pulmonary infection with P. aeruginosa.

Cellular target of in vitro-induced suppressor cells derived from the spleen of Mycobacterium lepraemurium-infected mice and role of IFN-gamma in their development

Unfractionated spleen cells from C3H mice infected a few weeks before with Mycobacterium lepraemurium developed a suppressor activity after overnight culture. This requires contact of plastic adherent cells with nonadherent cells distinct from T, B, or natural killer cells. The present study demonstrates that anti-interferon-gamma (IFN-gamma) monoclonal antibody and indomethacin totally abrogate the expression, although not the induction, of this activity. Furthermore, culture-induced suppressor cells selectively inhibit T lymphocyte proliferation, probably by altering the generation of interleukin-2 (IL-2) responsiveness through reduction of the affinity and density of high-affinity IL-2 receptors on activated cells. These and other previously determined properties of culture-induced suppressor cells, similar to those of adherent suppressor cells detected in freshly harvested spleen cells at a later stage of M. lepraemurium infection, suggest a common precursor. If so, the present observations should help in defining a strategy to prevent the impairment of cell-mediated immunity in infected mice.

Influence of the Ity/Lsh/Bcg gene on the development of suppressor cell precursors in the early phase of the infection of mice with Mycobacterium lepraemurium

In vitro inducible suppressor cell precursors were detected in the spleen of BALB/c but not in DBA/2 mice infected intraperitoneally with 10(8) Mycobacterium lepraemurium bacilli, thus suggesting that their development is genetically controlled. Two pairs of mouse strains congenic at the Ity/Lsh/Bcg locus (BALB/c-C.D2 and B10.A-B10.A.Bcgr) were used to investigate whether this phenomenon is influenced by this gene known to control the relative susceptibility of mice to Myco. lepraemurium infection. This seems likely, as the detection of culture-induced suppressor activity was delayed for 5-6 weeks in C.D2 and B10.A.Bcgr mice infected intravenously with 10(4) Myco. lepraemurium bacilli. However, despite the retardation in the detection of suppressor cell precursors, the level of in vitro induced suppressor activity at onset in spleen cell suspensions of mice carrying the resistant allele was higher than in cell cultures derived from susceptible mice. As the resistant allele has a different effect when found on BALB/c or DBA/2 background, other genetic factors are apparently involved in the development of suppressor cell precursors. We finally observed that, in spleen cell cultures from intravenously infected Ity/Lsh/Bcg congenic mice on the BALB/c background, adherent and non-adherent cells were required in the inductive phase of suppressor cell development, whereas in vitro induced suppressor activity was found exclusively in the adherent cell fraction. Given these properties, we thus conclude that suppressor cell precursors detected in the spleen of these intravenously infected mice are similar to those previously observed in C3H mice infected intraperitoneally with a thousand times more bacilli.

Cyclophosphamide treatment antagonizes the in vitro development of Mycobacterium lepraemurium-induced suppressor cell precursors

The in vitro-inducible maturation of splenic suppressor cell precursors detected during the early phase of Mycobacterium lepraemurium infection can be abrogated when a high dose of cyclophosphamide (Cy) is inoculated to infected mice 2 days before assay. The drug does not act directly on adherent suppressor cell precursors, but rather inhibits their activation by a non-adherent cell subset whose phenotype has not yet been elucidated. It was established by flow cytometry analyses, that despite a marked increase in the total number of splenic non-adherent cells following M. lepraemurium infection, the effect of Cy on Ia+, Thy-1+, CD4+ and CD8+ cells in infected mice was comparable to that observed in normal controls. It was not possible to determine the duration of the inhibiting effect of Cy on non-adherent regulatory cells, because the drug was itself inducing suppressor cells from 7 days after inoculation. By the time spleen cell suspensions were totally free of Cy-induced suppressor cells, infection-dependent suppressor cell precursors were once again detected, indicating that Cy treatment did not prevent their in vivo accumulation. Therefore, even though M. lepraemurium-induced adherent suppressor cell precursors are themselves fully resistant to Cy, their development is transiently abrogated by the drug, most probably through the impairment of a non-adherent cell subset regulating their maturation.

Early accumulation of suppressor cell precursors in the spleen of Mycobacterium lepraemurium-infected mice and analysis of their in vitro-induced maturation

Spleen cells harvested from mice infected intraperitoneally with M. lepraemurium 11-17 weeks prior to harvest acquired the capacity to inhibit concanavalin A (Con A) induced proliferation of normal spleen cells when precultured for up to 24 h in mitogen-free medium. The in vivo induced suppressor activity correlated with the length of the preculture period, the time post-infection and the infecting dose. These findings were interpreted as an indication that suppressor cell precursors accumulated in the spleen of infected mice during the early phase of the disease. The interaction of infection-dependent adherent suppressor cell precursors and infection-independent, non-adherent regulatory cells is necessary for the suppressor activity to develop. Both the cells which transmit the inductive signal and the precursor cells which mature into active suppressor cells are radiosensitive, whereas suppressor activity itself is a function of radioresistant adherent cells. Preculture of cells for a short period, before they were cocultured with Con A-stimulated normal spleen cells, allowed the detection of suppressor cells before they were deleterious to the infected host and also turned out to be a relevant in vitro model for characterization of suppressor cell development during M. lepraemurium infection.

Surgical removal of the fully impacted mandibular third molar. The influence of flap design and alveolar bone height on the periodontal status of the second molar

This study was carried out because a great deal of uncertainty exists as to he effect of the surgical removal of the fully impacted third molar on the periodontal status of the second molar. The objectives were to determine the effect of surgical removal of the third molar on the periodontal status of the second molar; the influence of flap design on these results; the influence of the initial height of the alveolar bone on the distal of the second molar on subsequent changes in attachment level. The study included 30 patients with bilateral mandibular impactions. A split-mouth experimental design was used, with one side of the mandible being randomly allocated to one of two flap design groups. Plaque level, gingival inflammation, probing depth and attachment level measurements around the second molar were taken at baseline and then at monthly intervals for a period of 6 months. Alveolar bone height was measured from panoramic radiographs. Six months postsurgically, both flap design groups exhibited a statistically significant loss of attachment level on the distal surface of the second molar with no difference between the two flap groups. The initial height of the alveolar bone on the distal of the second molar had no influence on the loss of attachment. It was concluded that the surgical removal of the fully impacted mandibular third molar led to the loss of attachment on the distal of the second molar; flap design had no influence on the degree of attachment loss; the initial height of the alveolar bone on the distal of the second molar had no influence on the loss of attachment.

Effect of ranitidine on healing of peptic ulcer: a 2-month study

A multicenter trial of oral ranitidine 150 mg bid was conducted in 41 patients with duodenal and 30 with gastric ulcers. Patients were randomly allocated in double-blind fashion to 4 wk treatment with either ranitidine or placebo, after which all unhealed patients were given 4 wk on the active drug without breaking the original allocation code. After 4 wk of treatment the healing rate associated with ranitidine was significantly superior to that of placebo in both duodenal and gastric ulcer patients. Further improvement in cumulative healing rates was observed after the 2nd month of the study. After the allocation code was broken and all patients had had the opportunity of up to 8 wk on the active drug, there remained only a single unhealed pyloric ulcer. No serious adverse effects or biochemical abnormalities were observed. Ranitidine is a potent and well-tolerated H2 antagonist. Therapy for 4 or 8 wk is highly effective in the treatment of uncomplicated gastroduodenal ulcer.

Evaluation of Duogastrome (carbenoxolone sodium) for the treatment of duodenal ulcer: a multicentre study

A double-blind study was carried out in 152 Canadian patients, 76 given Duogastrone (carbenoxolone sodium) capsules, 50 mg qid, and 76 given placebo capsules qid for 6 weeks. All patients had a duodenal ulcer diagnosed by roentgenography or endoscopy, or both. Evaluation of the efficacy of Duogastrone therapy was based on data from the 119 patients (59 treated with Duogastrone and 60 with placebo) who met all the strict requirements of the protocol. The ulcers healed completely in 75% (44/59) of the patients treated with Duogastrone and in 48% (29/60) of those treated with placebo; this difference is significant (P less than 0.01). The proportions were similar in the patients assessed only endoscopically: 76% (32/42) and 55% (26/47), respectively. In the group treated with Duogastrone the following side effects were noted: weight gain, edema, mild hypokalemia, increase in blood pressure and slight increases in serum concentrations of lactic dehydrogenase and alkaline phosphatase. None was serious. However, close clinical monitoring by weekly visits to their physician is recommended for every patient undergoing Duogastrone therapy, at least during the 1st month.