BIOCHAM: an environment for modeling biological systems and formalizing experimental knowledge

BIOCHAM (the BIOCHemical Abstract Machine) is a software environment for modeling biochemical systems. It is based on two aspects: (1) the analysis and simulation of boolean, kinetic and stochastic models and (2) the formalization of biological properties in temporal logic. BIOCHAM provides tools and languages for describing protein networks with a simple and straightforward syntax, and for integrating biological properties into the model. It then becomes possible to analyze, query, verify and maintain the model with respect to those properties. For kinetic models, BIOCHAM can search for appropriate parameter values in order to reproduce a specific behavior observed in experiments and formalized in temporal logic. Coupled with other methods such as bifurcation diagrams, this search assists the modeler/biologist in the modeling process.

AVAILABILITY

BIOCHAM (v. 2.5) is a free software available for download, with example models, at http://contraintes.inria.fr/BIOCHAM/.

The role of luteal phase support in infertility treatment: a meta-analysis of randomized trials

OBJECTIVE

To determine whether the use of luteal phase support improves pregnancy rate (PR) in infertility.

DESIGN

A meta-analysis of randomized trials of luteal phase support. Search of the National Library of Medicine MEDLINE data base from 1971 using the words luteal, pregnancy, human, and comparative. Bibliography of relevant articles, reviews, and abstracts of scientific meetings were hand searched. All randomized controlled trials of luteal phase support in infertility were included. Luteal phase support for recurrent abortion and nonrandomized trials were excluded. The common odds ratio was calculated for each intervention using the Mantel-Haentzel test. Homogeneity of treatment effect was evaluated using the Breslow-Day test.

MAIN OUTCOME MEASURES

Pregnancy per cycle, rate of spontaneous abortion, and ovarian hyperstimulation syndrome rate.

RESULTS

Eighteen trials met the above criteria. Human chorionic gonadotropin improved PRs in IVF when GnRH agonist (GnRH-a) was used (n = 151) and was superior to P (n = 352). Its benefit in all IVF cycles, however, was not established because of significant heterogeneity of treatment effect. Progesterone improved the PR in all IVF cycles (n = 457). No significant reduction in spontaneous abortion was noted with luteal support (n = 200). Ovarian hyperstimulation syndrome occurred in 5% of patients with hCG. Combination of data from trials of luteal support with other infertility therapies was not possible because of the differences in patient populations.

CONCLUSIONS

The meta-analysis supports the routine use of hCG in IVF cycles using a GnRH-a. Progesterone was also beneficial for luteal phase support in IVF. For other infertility therapy, however, further research is needed to evaluate the role of luteal phase support.

Depletion of total antioxidant capacity in type 2 diabetes

The purpose of the study was to examine the relationship between antioxidant depletion, glycemic control, and development of chronic complications in a controlled population of type 2 diabetic patients. Fifty age-matched type 2 diabetic patients receiving sulfonylureas but not insulin treatment were screened and assigned to two groups based on the presence or absence of proteinuria. A third group of normal subjects without diabetes were also enrolled in the study. All subjects in the three groups were Egyptians who were matched for body weight, and the two diabetic groups were also age-matched. Plasma glucose and fructosamine levels were higher in the two groups of diabetic patients versus the control group, but lipid peroxide levels were higher only in the patients with proteinuria. Compared with the control group, the total antioxidant capacity was depleted in the two diabetic groups, but the depletion was more severe in patients with proteinuria. Thus, the mean Trolox equivalent antioxidant capacity (TEAC) of the control group was 2.7+/-0.45, versus 1.7+/-0.5 (P < .001) in the patients without proteinuria. Furthermore, the TEAC measured in patients with proteinuria, who also had more diabetic complications, was lower (1.4+/-0.5, P < .001) than the TEAC in patients without urinary protein. In conclusion, a depletion of the total antioxidant capacity is associated with a higher incidence of diabetic complications.

Forward and reverse selection for longevity in Drosophila is characterized by alteration of antioxidant gene expression and oxidative damage patterns

Patterns of antioxidant gene expression and of oxidative damage were measured throughout the adult life span of a selected long-lived strain (La) of Drosophila melanogaster and compared to that of their normal-lived progenitor strain (Ra). Extended longevity in the La strain is correlated with enhanced antioxidant defense system gene expression, accumulation of CuZnSOD protein, and an increase in ADS enzyme activities. Extended longevity is strongly associated with a significantly increased resistance to oxidative stress. Reverse-selecting this long-lived strain for shortened longevity (RevLa strain) yields a significant decrease in longevity accompanied by reversion to normal levels of its antioxidant defense system gene expression patterns and antioxidant enzyme patterns. The significant effects of forward and reverse selection in these strains seem limited to the ADS enzymes; 11 other enzymes with primarily metabolic functions show no obvious effect of selection on their activity levels whereas six other enzymes postulated to play a role in flux control may actually be involved in NADPH reoxidation and thus support the enhanced activities of the ADS enzymes. Thus, alterations in the longevity of these Drosophila strains are directly correlated with corresponding alterations in; 1) the mRNA levels of certain antioxidant defense system genes; 2) the protein level of at least one antioxidant defense system gene; 3) the activity levels of the corresponding antioxidant defense system enzymes, and 4) the ability of the organism to resist the biological damage arising from oxidative stress.

Comparative biochemical and stress analysis of genetically selected Drosophila strains with different longevities

We have performed a comparative analysis of the effects of age of reproduction on the biochemical (protein, lipid, and glycogen content) and stress resistance (ability to survive starvation, desiccation, and exogenous paraquat) parameters on 10 sister lines of five different Drosophila strains. Four pairs of these sister lines were selected under different regimens for either early or delayed reproduction; the fifth pair was maintained in a nonselected state and served as the baseline strain to which all others were compared. It is generally accepted that the early regimens give rise to short-lived phenotypes, whereas the delayed regimens give rise to long-lived phenotypes. Our results suggest that a mechanism involving lipid and starvation resistance is not operative in our long-lived strains. In addition, a mechanism involving glycogen content and desiccation resistance is only weakly supported. Finally, there is strong support for a mechanism that gives rise to enhanced paraquat resistance and therefore may involve regulatory changes in the pattern of ADS gene expression. In addition, the 15-day early age of reproduction regimen (M type) shows qualitatively similar responses to that of the late age at reproduction regimen (L type). These results suggest that correlations between biochemical traits and longevity must be interpreted with caution. We discuss possible reasons for these results, including the possibility of multiple mechanisms, each leading to a different extended longevity phenotype.

Regional differences in hypoxic depolarization and swelling in hippocampal slices

Pyramidal neurons in the CA1 region of the hippocampus are highly vulnerable to damage from hypoxia-ischemia, whereas neurons in the CA3 region and the dentate gyrus are more resistant. A similar pattern of vulnerability to loss of synaptic and membrane function occurs in the in vitro hippocampal slice preparation, suggesting that intrinsic factors are important in acute neuronal damage. Simultaneous recordings of DC potential and imaging of changes in light transmittance were made in slices from the middle one-third of the hippocampus to characterize the initiation and spread of depolarization and swelling during hypoxia-aglycemia. Hypoxic depolarization (HD) and associated optical changes were initiated simultaneously in the stratum oriens of the CA1 region and thereafter spread to the stratum radiatum of CA1 and later to the upper (inner) blade of the dentate gyrus. A decrease in light transmittance was associated consistently with depolarization in all regions (n = 22 slices). Investigation of the sequence of activation in intact slices showed that activation of the dentate gyrus arose independently of activation of the CA1 region. This was confirmed by recordings made from minislices in which CA1, CA3, and dentate regions were physically separated. HD and optical changes were never observed in the CA3 region, despite exposure to 40-60 min of combined hypoxia and aglycemia. In contrast, exposure to hypoxia after pretreatment of slices with altered tonicity or ion composition, which triggered episodes of spreading depolarization (SD), provoked depolarization and optical changes simultaneously in both CA1 and CA3 regions. Similarly, pretreatment with agents that cause severe metabolic impairment, such as dinitrophenol (DNP), also rendered the CA3 region vulnerable to subsequent hypoxia. This suggests that the CA3 region in hippocampal slices is normally resistant to HD and only becomes vulnerable after severe impairment of metabolic capacity. The similar order of vulnerability of in vitro and in vivo hippocampus to hypoxia-aglycemia supports the use of the hippocampal slice preparation to investigate early changes potentially contributing to hypoxic-ischemic injury.

A general computational method for robustness analysis with applications to synthetic gene networks

Motivation: Robustness is the capacity of a system to maintain a function in the face of perturbations. It is essential for the correct functioning of natural and engineered biological systems. Robustness is generally defined in an ad hoc, problem-dependent manner, thus hampering the fruitful development of a theory of biological robustness, recently advocated by Kitano.

Results: In this article, we propose a general definition of robustness that applies to any biological function expressible in temporal logic LTL (linear temporal logic), and to broad model classes and perturbation types. Moreover, we propose a computational approach and an implementation in BIOCHAM 2.8 for the automated estimation of the robustness of a given behavior with respect to a given set of perturbations. The applicability and biological relevance of our approach is demonstrated by testing and improving the robustness of the timed behavior of a synthetic transcriptional cascade that could be used as a biological timer for synthetic biology applications.

Availability: Version 2.8 of BIOCHAM and the transcriptional cascade model are available at http://contraintes.inria.fr/BIOCHAM/

Contact:gregory.batt@inria.fr

A randomized trial of in vitro fertilization versus conventional treatment for infertility

OBJECTIVE

To evaluate the effectiveness of IVF in couples with infertility.

DESIGN

Two hundred forty-five consecutive couples with infertility were randomized to receive one cycle of IVF treatment (experimental group) or to wait for a period of 6 months before receiving IVF treatment, during which time other infertility treatments could have been undertaken (control group).

SETTING

Patients were referred to the Fertility Clinic at Chedoke-McMaster Hospitals, a university-associated institution in Hamilton, Ontario, Canada, in which IVF has been offered to couples since 1984.

PATIENTS

Couples with infertility (mean duration of 65 months) not corrected by conventional treatment. They came from all socioeconomic classes, and the costs of IVF treatment, except medication, were covered by the Ontario Health Insurance Plan.

MAIN OUTCOME MEASURE

Pregnancy was confirmed by ultrasound documentation of a gestational sac or histologic examination of tissue. Outcomes included livebirth, spontaneous abortion, and ectopic pregnancy. The overall pregnancy rate (PR) and the interval-to-pregnancy duration were compared in each group.

RESULTS

Univariate analysis demonstrated a significant beneficial effect of IVF treatment in patients with bilateral severe tubal disease. Although in other diagnostic categories the crude and cumulative PRs in the experimental group were higher than in the control group, the differences did not reach statistical significance. Among the early IVF group, those with endometriosis had significantly more pregnancies when compared with other diagnostic categories. Although IVF increases the likelihood of pregnancy by 40% with severe tubal disease, the overall 31% increase associated with IVF was not statistically significant.

CONCLUSIONS

There was a significant difference in favor of treatment in patients with severe bilateral tubal disease. For couples with other causes of infertility, the confidence limits around the treatment effect included unity. To reject the null hypothesis of no treatment effect, a larger sample size or a meta-analysis to combine the results of similar trials is required.

A graphical method for reducing and relating models in systems biology

Motivation: In Systems Biology, an increasing collection of models of various biological processes is currently developed and made available in publicly accessible repositories, such as biomodels.net for instance, through common exchange formats such as SBML. To date, however, there is no general method to relate different models to each other by abstraction or reduction relationships, and this task is left to the modeler for re-using and coupling models. In mathematical biology, model reduction techniques have been studied for a long time, mainly in the case where a model exhibits different time scales, or different spatial phases, which can be analyzed separately. These techniques are however far too restrictive to be applied on a large scale in systems biology, and do not take into account abstractions other than time or phase decompositions. Our purpose here is to propose a general computational method for relating models together, by considering primarily the structure of the interactions and abstracting from their dynamics in a first step.

Results: We present a graph-theoretic formalism with node merge and delete operations, in which model reductions can be studied as graph matching problems. From this setting, we derive an algorithm for deciding whether there exists a reduction from one model to another, and evaluate it on the computation of the reduction relations between all SBML models of the biomodels.net repository. In particular, in the case of the numerous models of MAPK signalling, and of the circadian clock, biologically meaningful mappings between models of each class are automatically inferred from the structure of the interactions. We conclude on the generality of our graphical method, on its limits with respect to the representation of the structure of the interactions in SBML, and on some perspectives for dealing with the dynamics.

Availability: The algorithms described in this article are implemented in the open-source software modeling platform BIOCHAM available at http://contraintes.inria.fr/biocham The models used in the experiments are available from http://www.biomodels.net/

Contact:francois.fages@inria.fr

Effect of sex, size, and age of commensal rat hosts on the infestation parameters of their ectoparasites in a rural area of Egypt

The present study was carried out in the Bilbeis area, Sharqiya Governorate, Egypt. A total of 127 male and 115 female black rats Rattus rattus and 124 male and 153 female Norway rats R. norvegicus was collected during the study period. A total of 20,643 and 40,997 ectoparasites was recovered from R. rattus and R. norvegicus, respectively. Three common mite species were recovered from both rat hosts: Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three common flea species were also recovered from both rat hosts: Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis. Polyplax spinulosa was the only louse species that infested both rat hosts. Rats that lived more than 12 mo formed about 24 and 14% of the populations of the black and Norway rats, respectively. The prevalences and general indices of many ectoparasites were significantly higher on males than on females of both rat hosts. Seasonal differences in prevalences and general indices of many ectoparasites were recorded between the 2 sexes of both rat species. Prevalences and general indices of most ectoparasites on both rat species showed a tendency to increase with increasing size and age of rat hosts. The type and degree of correlation between prevalences and general indices on the one hand and each of body size and age on the other hand differed among the species of ectoparasites.

Identical longevity phenotypes are characterized by different patterns of gene expression and oxidative damage

Some years ago we applied simultaneously an identical regime of selection for late-life reproduction to several normal-lived sister lines (Ra and Rb) so as to produce several selected long-lived sister lines (La and Lb). The long-lived La and Lb sister lines had statistically identical longevity phenotypes and paraquat resistance phenotypes; however, we noticed some statistically different responses of the two strains at the biochemical level. Extensive work with the La strain showed that transcriptional alterations in antioxidant gene expression are robustly associated with its extended longevity. We decided to critically test the assumption of phenotypic equivalence by subjecting the Lb strain to the same series of molecular assays as was the La strain. The two sister strains are characterized by significantly different mechanisms and patterns of antioxidant gene expression, antioxidant enzyme activity, and oxidative damage. We find that the Lb strain appears to depend on the transcriptional activation of different genes than does the La strain, and on a post-translational up-regulation of at least one other antioxidant defense gene. The phenotypic equivalence observed at the organism level need not hold at the molecular genetic level. This finding suggests that there is more than one molecular mechanism by which antioxidant defense genes can bring about an increased resistance to oxidative stress. The theoretical and empirical implications of these findings are discussed.

Safety of formoterol by Turbuhaler as reliever medication compared with terbutaline in moderate asthma

The present study compared the safety of 4.5 microg formoterol with 0.5 mg terbutaline, both by Turbuhaler and used as needed, in addition to regular formoterol in moderate asthma. In this double-blind parallel-group study, 357 patients taking a moderate-to-high dose of inhaled corticosteroids and additional terbutaline (2-5 inhalations x day(-1) during run-in) were randomised to either formoterol or terbutaline as needed in addition to formoterol 9 microg b.i.d. over 12 weeks. Adverse events, serum potassium levels, electrocardiogram, vital signs and lung function were assessed monthly; peak expiratory flow and severe asthma exacerbations were recorded daily. Patients used 2.16 (range 0.0-6.3) formoterol and 2.34 (range 0.1-7.5) terbutaline relief inhalations x day(-1). No clinically significant differences in safety variables were found between treatments. Statistically greater increases in cardiac frequency (2.6 beats x min(-1), p=0.03) were found on terbutaline. There were 44 and 52 severe asthma exacerbations with formoterol and terbutaline, respectively, with no significant difference in time to first exacerbation. There was also no difference between treatments for other efficacy measures (peak expiratory flow, forced expiratory volume in one second and morning/evening symptom scores). Formoterol 4.5 microg as needed was at least as safe, well tolerated and effective as terbutaline 0.5 mg in stable patients (requiring up to 6 relief inhalations x day(-1)) taking formoterol plus inhaled corticosteroids regularly over 12 weeks.

Automated inference of Boolean models from molecular interaction maps using CaSQ

Motivation

Molecular interaction maps have emerged as a meaningful way of representing biological mechanisms in a comprehensive and systematic manner. However, their static nature provides limited insights to the emerging behaviour of the described biological system under different conditions. Computational modelling provides the means to study dynamic properties through in silico simulations and perturbations. We aim to bridge the gap between static and dynamic representations of biological systems with CaSQ, a software tool that infers Boolean rules based on the topology and semantics of molecular interaction maps built with CellDesigner.

Results

We developed CaSQ by defining conversion rules and logical formulas for inferred Boolean models according to the topology and the annotations of the starting molecular interaction maps. We used CaSQ to produce executable files of existing molecular maps that differ in size, complexity and the use of Systems Biology Graphical Notation (SBGN) standards. We also compared, where possible, the manually built logical models corresponding to a molecular map to the ones inferred by CaSQ. The tool is able to process large and complex maps built with CellDesigner (either following SBGN standards or not) and produce Boolean models in a standard output format, Systems Biology Marked Up Language-qualitative (SBML-qual), that can be further analyzed using popular modelling tools. References, annotations and layout of the CellDesigner molecular map are retained in the obtained model, facilitating interoperability and model reusability.

Availability and implementation

The present tool is available online: https://lifeware.inria.fr/∼soliman/post/casq/ and distributed as a Python package under the GNU GPLv3 license. The code can be accessed here: https://gitlab.inria.fr/soliman/casq.

Supplementary information

Supplementary data are available at Bioinformatics online.

COVID19 Disease Map, a computational knowledge repository of virus-host interaction mechanisms

We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, bioinformaticians and computational biologists. The diagrams of the C19DMap, curated from the literature, are integrated with relevant interaction and text mining databases. We demonstrate the application of network analysis and modelling approaches by concrete examples to highlight new testable hypotheses. This framework helps to find signatures of SARS-CoV-2 predisposition, treatment response or prioritisation of drug candidates. Such an approach may help deal with new waves of COVID-19 or similar pandemics in the long-term perspective.

Epidemiology of cutaneous leishmaniasis at a focus monitored by the multinational force and observers in the northeastern Sinai Desert of Egypt

A longitudinal epidemiologic study of cutaneous leishmaniasis (CL) transmission was conducted between July 1989 and June 1991 in a 1,200-km2 sector of the northeastern Sinai Desert monitored by the Multinational Force and Observers (MFO), an international peace keeping mission between Egypt and Israel. The occurrence of human cases, sand fly density, rodent collection, and isolations of Leishmania confirmed only one of four surveyed locations as a significant focus of CL transmission. Phlebotomus papatasi, the only anthropophilic sand fly species encountered at this focus, comprised more than 96% of the sand fly population and attained human landing densities exceeding 100 sand flies/person/hr during 1990. Seasonal activity of this species ranged from April to November, with highest densities occurring during the period May-September. A peak promastigote infection rate of 2.4% (13 of 534) was observed in P. papatasi during July 1990. Twelve of the 60 (20%) persons at risk during the six months of intense sand fly activity at this site developed lesions consistent with CL; L. major was isolated from nine (75%) of these cases. Leishmania major infection was acquired by two of 22 (9%) sentinel hamsters used during the same period. More than 97% of the 897 wild rodents trapped at this site were desert gerbil species. Leishmania major was the only Leishmania isolated from human, sand fly, wild rodent (Gerbillus pyramidum), and sentinel hamster infections that originated at site Check point 1-Delta, the focus of CL transmission within jurisdiction of the MFO. The altered ecology of this area, created by construction of a dam, may contribute significantly to the transmission dynamics of CL at this focus.

Formoterol via Turbuhaler gave better protection than terbutaline against repeated exercise challenge for up to 12 hours in children and adolescents

We aimed to compare the protective effect of single doses of 4.5 and 9 microg of formoterol fumarate (F), 0.5 mg terbutaline sulphate (T) and placebo (P), all via Turbuhaler, against exercise-induced bronchoconstriction (EIB) in children. Twenty-seven asthmatic children, showing a fall of > or =20% in FEV1 after a standardized exercise challenge test (ECT) combined with cold air (-10 degrees C) inhalation, were randomized in this cross-over, double-blind study. They had a mean age of 12.6 years (range 8-17 years), mean baseline FEV1 90% (73.9-105.6%) of predicted normal value. Seventeen children used inhaled glucocorticosteroids (120-750 microg day(-1)). ECTs were performed 15 min and 4, 8, and 12 h after drug administration. F significantly reduced the fall in FEV1 after ECT to 5.4% (15 min), 5.2% (4 h), 8.2% (8 h) and 9.3% (12 h) after 4.5 microg, and 2.5%, 3.0%, 5.0% and 5.4% after 9 microg, compared with a fall of 18.4%, 15.7%, 15.6% and 16.5% in FEV1 after P. The fall after T was 3.3%, 11.6%, 14.4% and 19.1% after 15 min, 4, 8 and 12 h respectively. The difference between F and T was statistically significant from 4 h and onward (P-value for all comparisons < 0.05). Children using a single dose of either formoterol Turbuhaler 4.5 or 9 microg had significantly better bronchoprotection against repeated exercise challenge up to 12 h compared with placebo and from 4 h onward compared with terbutaline Turbuhaler 0.5 mg.

A unique transformation from ordinary differential equations to reaction networks

Many models in Systems Biology are described as a system of Ordinary Differential Equations, which allows for transient, steady-state or bifurcation analysis when kinetic information is available. Complementary structure-related qualitative analysis techniques have become increasingly popular in recent years, like qualitative model checking or pathway analysis (elementary modes, invariants, flux balance analysis, graph-based analyses, chemical organization theory, etc.). They do not rely on kinetic information but require a well-defined structure as stochastic analysis techniques equally do. In this article, we look into the structure inference problem for a model described by a system of Ordinary Differential Equations and provide conditions for the uniqueness of its solution. We describe a method to extract a structured reaction network model, represented as a bipartite multigraph, for example, a continuous Petri net (CPN), from a system of Ordinary Differential Equations (ODEs). A CPN uniquely defines an ODE, and each ODE can be transformed into a CPN. However, it is not obvious under which conditions the transformation of an ODE into a CPN is unique, that is, when a given ODE defines exactly one CPN. We provide biochemically relevant sufficient conditions under which the derived structure is unique and counterexamples showing the necessity of each condition. Our method is implemented and available; we illustrate it on some signal transduction models from the BioModels database. A prototype implementation of the method is made available to modellers at http://contraintes.inria.fr/~soliman/ode2pn.html, and the data mentioned in the “Results” section at http://contraintes.inria.fr/~soliman/ode2pn_data/. Our results yield a new recommendation for the import/export feature of tools supporting the SBML exchange format.

The use of long-term defunctionalized bladder in renal transplantation: is it safe?

OBJECTIVE

Evaluation of the use of defunctionalized bladder in renal transplantation, concerning surgical complications.

METHODS

In order to assess the complication rate of ureteral reimplantation in long-term defunctionalized bladder, we compared 20 patients on haemodialysis for more than 15 years (group I) with another 20 patients on haemodialysis for less than 5 years (group II). None of these patients had renal failure due to urological causes or neurogenic bladder. Non-stented extravesical ureteroneocystostomy was done routinely in all patients except 1 in group II who underwent Politano-Leadbetter ureteroneocystostomy and 7 patients in group I who underwent Politano-Leadbetter (3 patients) and pyelo-ureteral anastomosis using the recipient's native ureter (4 patients). The amount of residual urine was insignificant (<100 cm(3)) in both groups.

RESULTS

The mean postoperative bladder catheterization period was 7.8 days in group I and 4.2 days in group II. Postoperative urinary tract infections were observed in 9 cases of group I and in 4 cases of group II. No surgical complications occurred in patients of group II, while there were 6 patients with surgical complications in group I: stenosis after a pyelo-ureteral anastomosis (1 case), stenosis after a ureterovesical anastomosis with Politano-Leadbetter technique (1 case), urinary fistulae (3 cases; 1 with Politano-Leadbetter ureteroneocystostomy and 2 cases with pyelo-ureteral anastomosis), and vesico-ureteral reflux (1 case with Politano-Leadbetter ureteroneocystostomy). These 6 cases had the lowest bladder capacity (30-150 cm(3)) among our 40 patients. Graft losses were comparable between the two groups and were not due to surgical complications.

CONCLUSION

Small defunctionalized bladders can be used in kidney transplantation, but it may represent an increased surgical risk due to difficulty in performing ureteral reimplantation.

Seasonal studies on commensal rats and their ectoparasites in a rural area of Egypt: the relationship of ectoparasites to the species, locality, and relative abundance of the host

The present study was carried out in 3 villages, namely Kafr Ayoub Soliman, Kafr Ibrahim El-Aidi, and El-Sa'adat, Sharqiya Governorate, Egypt. A total of 519 rats was collected from the 3 study sites: 46.6% Rattus rattus, and 53.4% Rattus norvegicus. A total of 20,643 ectoparasites was recovered from R. rattus: 33.3% mites, 33.8% fleas, and 32.9% lice. From R. norvegicus a total of 40,997 ectoparasites was recovered: 28.9% mites, 31% fleas, and 40.1% lice. Three common mite species were recovered from both rat hosts, i.e., Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three common flea species were also recovered from both rat hosts, i.e., Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis. Polyplax spinulosa was the only dominant louse species that infested both rat hosts. Rats did not show a definite breeding season, and the seasonal rat indices were generally low in different study sites. There were no significant differences between the prevalence of each of mites, fleas, and lice in both rat species. The total general indices of mites and fleas, on the other hand, was significantly higher in R. norvegicus. The general index of X. cheopis was high and ranged between 5.9 in R. rattus and 14.5 in R. norvegicus. Season-related changes were observed in the general index of each of L. segnis infesting both rat species and R. ensifera and O. bacoti infesting R. norvegicus. The prevalence and general indices of some ectoparasites showed differences related to the locality of their rat hosts. Seasonal changes in the general indices of some ectoparasites paralleled seasonal changes in the relative abundance of their rat hosts.

Safety and efficacy of a high cumulative dose of salbutamol inhaled via Turbuhaler or via a pressurized metered-dose inhaler in patients with asthma

An open, crossover and randomized study was carried out to compare the safety and efficacy of salbutamol inhaled using the dry-powder inhaler Turbuhaler, and using a pressurized metered-dose inhaler (pMDI). Twelve patients with moderate to severe asthma, aged 47-68 years, were included in the study. On two separate days, patients received a total dose of 1600 micrograms of salbutamol administered in a cumulative dose fashion: 100, 100, 200, 400 and 800 micrograms at 3-min intervals. Salbutamol inhaled via Turbuhaler caused a larger decrease in serum potassium concentration than did salbutamol inhaled via pMDI. The estimated relative dose potency of the hypokalaemic effect of salbutamol Turbuhaler vs salbutamol pMDI was 2.0 with a 95% confidence interval of 1.3-3.6. Turbuhaler caused a small (but statistically significantly greater than with pMDI) increase in heart rate, QTc interval and tremor. Blood pressure was unaffected by the treatments. No adverse events of clinical relevance were reported. The estimated relative dose potency of the bronchodilating effect (FEV1) of salbutamol Turbuhaler vs salbutamol pMDI was 3.0 with a 95% confidence interval of 1.8-5.8. In conclusion, salbutamol inhaled via Turbuhaler was more potent and seemed to have a better therapeutic ratio than salbutamol inhaled via pMDI. Both treatments were equally well tolerated.

Low-dose formoterol Turbuhaler (Oxis) b.i.d., a 3-month placebo-controlled comparison with terbutaline (q.i.d.)

This study compared the efficacy of a low dose of formoterol Turbuhaler 6 micrograms b.i.d. (F) with that of terbutaline 0.5 mg q.i.d. (T), and placebo (P) from Turbuhaler. After a 2-week run-in, 397 adults with mild to moderate asthma were randomly allocated to one of the treatments for 12 weeks. During run-in, the mean morning peak expiratory flow (PEF) was 360 (F), 368 (T) and 367 1 min-1 (P). F was better than T (P = 0.014) and P (P = 0.0001) in improving morning PEF [mean changes from run-in: 20 (F), 9 (T), and 21 min-1 (P)]. F was statistically significantly more effective than either T or P in reducing asthma symptoms. F gave also statistically significantly higher evening PEF and less use of rescue medication than P. Bronchodilator response to study drugs and additional 1.25 mg terbutaline was similar before and after the 12-week treatment period. There were no adverse effects of clinical relevance. In conclusion, formoterol Turbuhaler, 6 micrograms b.i.d. was more effective in improving PEF and offered better asthma control than either terbutaline Turbuhaler, 0.5 mg q.i.d. or placebo. Regular use of formoterol did not reduce the bronchodilator response to additional terbutaline. There were no clinically relevant adverse effects.

A 3-month comparison of formoterol with terbutaline via turbuhaler. A placebo-controlled study

BACKGROUND AND AIM

Oxis Turbuhaler is a new dry powder formulation of long-acting beta2-agonist formoterol. This study compared the efficacy and safety of regular use of the long-acting beta2-agonist formoterol and the short-acting terbutaline for 3 months in patients with asthma.

METHOD

After 1-week run-in, 343 patients received either formoterol 12 microg bid (F) (delivered dose of 9 microg), terbutaline 500 microg qid (T) or placebo qid, in a parallel-group, double-blind, randomized manner. They had a mean of 61% of predicted forced expiratory volume in 1 second (FEV1) and a mean reversibility of 26%. Eighty-nine percent used inhaled corticosteroids.

RESULTS

During run-in mean morning peak expiratory flow (PEF L/min) for F was 366 and 348 for T, and 344 for placebo (P). The F group improved morning PEF significantly compared with P (P = .0022) and T (P = .0001). Changes from run-in were + 18, -1.5, and +5 L/min after F, T, and P, respectively. The F group was statistically significantly better than P and T in increasing evening PEF and in reducing night-time asthma. The F and T statistically significantly reduced the use of rescue medication compared with P. The bronchodilating response to the study drug and to an additional 1.25 mg terbutaline was of the same magnitude before and throughout the study. No statistically significant treatment-by-time interaction was observed (P > .20). There were no adverse effects of clinical relevance.

CONCLUSION

Formoterol Turbuhaler, 12 microg bid, was more effective than terbutaline Turbuhaler, 0.5 mg qid, and placebo. Regular use of formoterol or terbutaline did not significantly influence the response to additional inhalation of terbutaline.

A placebo-controlled dose-finding study with bambuterol in elderly patients with asthma

A new long-acting bronchodilator prodrug, bambuterol hydrochloride, was tested in a randomized, crossover, and double-blind study in elderly asthmatic patients (aged 64 to 82 years). They received placebo and 5-mg, 10-mg, and 20-mg tablets once daily for a week at each dose. The plasma concentration of the active metabolite, terbutaline, increased linearly with the dose of drug (p < 0.001). Peak expiratory flow rate increased with dose in the morning (p < 0.001 for 10-mg and 20-mg doses) and afternoon (p < 0.05 for 10 mg; p < 0.001 for 20 mg) and was different from placebo for the 10-mg/d and 20-mg/d regimens. The use of supplemental inhaled beta 2-adrenergic agonist therapy was reduced during the night for the 10-mg (p < 0.05) and 20-mg (p < 0.01) doses in comparison to placebo. No significant effects of treatment on blood pressure and pulse were demonstrated. Tremor and palpitations were mild and related to the dose. These data suggest that treatment once daily with bambuterol hydrochloride in a dose of 10 or 20 mg improves pulmonary function and is well tolerated as bronchodilator therapy in elderly patients with asthma.