Evaluation of Simultaneous Transmission of Chikungunya Virus and Dengue Virus Type 2 in Infected Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

The simultaneous transmission of chikungunya virus (CHIKV) and dengue viruses (DENV) has been a major public health concern because of their sympatric distribution and shared mosquito vectors. Groups of Aedes aegypti (L.) and Aedes albopictus (Skuse) were orally infected with 1.5 × 10(5) PFU/ml of CHIKV and 3.2 × 10(6) FFU/ml of DENV-2 simultaneously or separately in inverse orders and evaluated for dissemination and transmission by qRT-PCR. Simultaneous dissemination of both viruses was detected for all groups in Ae. aegypti and Ae. albopictus while cotransmission of CHIKV and DENV-2 only occurred at low rates after sequential but not simultaneous infection.

A rodent model of mild traumatic brain blast injury.

One of the criteria defining mild traumatic brain injury (mTBI) in humans is a loss of consciousness lasting for less than 30 min. mTBI can result in long-term impairment of cognition and behavior. In rats, the length of time it takes a rat to right itself after injury is considered to be an analog for human return to consciousness. This study characterized a rat mild brain blast injury (mBBI) model defined by a righting response reflex time (RRRT) of more than 4 min but less than 10 min. Assessments of motor coordination relying on beam-balance and foot-fault assays and reference memory showed significant impairment in animals exposed to mBBI. This study's hypothesis is that there are inflammatory outcomes to mTBI over time that cause its deleterious effects. For example, mBBI significantly increased brain levels of interleukin (IL)-1ß and tumor necrosis factor-α (TNFα) protein. There were significant inflammatory responses in the cortex, hippocampus, thalamus, and amygdala 6 hr after mBBI, as evidenced by increased levels of the inflammatory markers associated with activation of microglia and macrophages, ionized calcium binding adaptor 1 (IBA1), impairment of the blood-brain barrier, and significant neuronal losses. There were significant increases in phosphorylated Tau (p-Tau) levels, a putative precursor to the development of neuroencephalopathy, as early as 6 hr after mBBI in the cortex and the hippocampus but not in the thalamus or the amygdala. There was an apparent correlation between RRRTs and p-Tau protein levels but not IBA1. These results suggest potential therapies for mild blast injuries via blockade of the IL-1ß and TNFα receptors.

DNA dinucleotide evolution in humans: fitting theory to facts.

We examine length distributions of approximately 6000 human dinucleotide microsatellite loci, representing chromosomes 1-22, from the GDB database. Under the stepwise mutation model, results from theory and simulation are compared with the empirical data. In both constant and expanding population scenarios, a simple single-step model with parameters chosen to account for the observed variance of microsatellite lengths produces results inconsistent with the observed heterozygosity and the dispersion of length skewness. Complicating the model by allowing a variable mutation rate accounts for the homozygosity, and introducing a small probability of a large mutation step accounts for the dispersion in skewnesses. We discuss these results in light of the long-term evolution of microsatellites.

The calcium channel blocker used with cyclosporin has an effect on gingival overgrowth.

BACKGROUND/AIMS: To investigate whether the choice of calcium channel blocker, used in conjunction with cyclosporin A, affected the prevalence of gingival overgrowth. METHOD: A cohort of 135 renal transplant recipients who had been medicated with cyclosporin A in combination with either nifedipine (89) or amlodipine (46) since transplant, took part in the study. The inclusion criteria were that eligible subjects had been in receipt of a kidney transplant for at least 12 months, had at least 10 teeth and had not received specialist periodontal treatment. The age, gender, current drug regimen and dosage were recorded for each participant and alginate impressions taken of both arches. The presence and severity of gingival overgrowth were scored from plaster models. RESULTS: A higher proportion (72%) of the amlodipine group were categorised as having gingival overgrowth compared with only 53% of the nifedipine group, chi square=4.5, p<0.05. Logistic regression analysis was used to explore the relationship between the presence or absence of gingival overgrowth (dependent variable) and age, gender, time since transplant, dose of cyclosporin A, centre in which the patient was treated, and the calcium channel blocker used (independent variables). Independent predictors of gingival overgrowth in this multivariate analysis were whether the individual was treated with amlodipine or nifedipine (p=0.01) and whether the individual was young or old (p=0.01). Within the multivariate analysis, the odds ratio for amlodipine to be associated with gingival overgrowth compared with nifedipine was 3.0 (confidence interval 1.3-6.9). CONCLUSIONS: The prevalence of gingival overgrowth in renal transplant recipients maintained on cyclosporin A and nifedipine is lower than those treated with cyclosporin A and amlodipine.

Reduction in gingival overgrowth associated with conversion from cyclosporin A to tacrolimus.

BACKGROUND: Unsightly gingival overgrowth affects many individuals immunosuppressed with cyclosporin A (CsA). Current management involves repeated periodontal surgery and intensive hygienist support. Tacrolimus is an effective alternative immunosuppressive agent for renal transplantation which does not appear to produce gingival enlargement. AIMS: The purpose of the present study was to monitor the gingival response of 4 renal transplant patients (RTPs), with clinically significant CsA-induced gingival overgrowth, after their immunosuppressive therapy was switched to tacrolimus. METHODS: Intra-oral photographs and alginate impressions were taken both prior to the drug conversion and again, 6 to 9 months later. Gingival overgrowth scores were determined, from plaster models on both these occasions. RESULTS: All of the RTPs experienced significant resolution of their gingival enlargement within the time period studied; however, only one had complete regression. CONCLUSION: It is concluded that conversion of RTPs with gingival overgrowth from CsA to tacrolimus may provide an effective management strategy for this clinical problem.

Cyclosporin associated gingival overgrowth in renal transplant recipients.

OBJECTIVES: To investigate the prevalence and severity of gingival overgrowth in a group of renal transplant recipients treated in one centre in Northern Ireland. STUDY DESIGN: A consecutive group of patients who had had a renal transplant for at least 6 months and were attending the Renal Unit in Belfast City Hospital took part in the study. These were divided into a group of 84 subjects treated with cyclosporin since their transplant who were compared with a control group of 36 transplant recipients who had never received cyclosporin. Each subject had a periodontal examination and completed a questionnaire. The severity of gingival overgrowth was scored from plaster models. OUTCOME MEASURES: Clinically significant gingival overgrowth was equated with a score of > or = 30 using the index developed by Seymour et al (1985). RESULTS: 41 (49%) of the cyclosporin group had clinically significant gingival overgrowth compared with none of the controls. A significantly higher proportion of males had overgrowth than females. There were significant correlations between age at transplant, plaque, bleeding, pocketing and the severity of gingival overgrowth. Many patients with clinically significant gingival overgrowth were apparently unconcerned about this condition. CONCLUSIONS: It is concluded that gingival overgrowth is a significant problem for renal transplant patients treated with cyclosporin, particularly if they are also treated with a calcium channel blocker. None of the factors measured, in isolation, explained the variable expression of gingival overgrowth in those at risk.

Immunoreactive trypsin in Shwachman's syndrome.

We studied two infants with Shwachman's syndrome in whom the immunoreactive trypsin concentration was found to be abnormally low. Experience with several hundred assays for immunoreactive trypsin has not shown this low concentration. This finding is probably specific for pancreatic acinar deficiency at this age and strongly suggests Shwachman's syndrome.

Sulfate reduction in peat from a new jersey pinelands cedar swamp.

Microbial sulfate reduction rates in acidic peat from a New Jersey Pine Barrens cedar swamp in 1986 were similar to sulfate reduction rates in freshwater lake sediments. The rates ranged from a low of 1.0 nmol cm day in February at 7.5- to 10.0-cm depth to 173.4 nmol cm day in July at 5.0- to 7.5-cm depth. The presence of living Sphagnum moss at the surface generally resulted in reduced rates of sulfate reduction. Pore water sulfate concentrations and water table height also apparently affected the sulfate reduction rate. Concentrations of sulfate in pore water were nearly always higher than those in surface water and groundwater, ranging from 26 to 522 muM. The elevated pore water sulfate levels did not result from the evapotranspiratory concentration of infiltrating stream water or groundwater, but probably resulted from oxidation of reduced sulfur compounds, hydrolysis of ester sulfates present in the peat, or both. The total sulfur content of peat that had no living moss at the surface was 164.64 +/- 1.5 and 195.8 +/- 21.7 mumol g (dry weight) for peat collected from 2.5 to 5.0 and 7.5 to 10.0 cm, respectively. Organosulfur compounds accounted for 84 to 88% of the total sulfur that was present in the peat. C-bonded sulfur accounted for 91 to 94% of the organic sulfur, with ester sulfate being only a minor constituent. Reduced inorganic sulfur species in peat from 2.5 to 7.5 cm were dominated by H(2)S-FeS (68%), while pyritic sulfide was the predominant inorganic sulfur species in the peat from depths of 7.5 to 10.0 cm (75%).

Human factor IX inhibitors: immunochemical characteristics and treatment with activated concentrate.

Plasma was obtained from two patients with severe factor IX deficiency who had developed specific inhibitors of factor IX. Immunochemical characterization of the inhibitors by coagulation inhibitor neutralization assays and by immunoelectrophoretic methods demonstrated that both were IgG antibodies. One of the antibodies appeared to be monoclonal in origin with IgG subclass 4 heavy chains and lambda light chains. The other appeared to be oligoclonal and contained IgG subclass 1 and subclass 4 heavy chains and kappa and lambda light chains. One of the patients was treated with conventional, non-activated factor IX concentrate and with activated factor IX concentrate (Feiba) for repeated bleeding episodes. Administration of Feiba resulted in a progressive shortening of the kaolin cephalin clotting time and was followed by a good clinical response. Infusion of non-activated factor IX concentrate failed to induce clinical resolution of haemarthroses and had minimal effect on laboratory tests. The presence of circulating immune complexes could not be demonstrated in this patient.

Carbon monoxide metabolism in roadside soils.

Air-dried soils which were equilibrated under relative humidities greater than 93% or moistened with liquid water showed marked increases in their capacities to oxidize CO to CO(2). Liquid water addition in excess of saturation resulted in lower CO oxidation rates, reflecting the limited diffusion of CO through the aqueous phase. After 35 days' storage under 100% relative humidity, the capacity for CO oxidation decreased to 21% of the value observed with a freshly collected sample. Incubation of this stored soil under an atmosphere containing 200 ppm of CO (250 mg/m) for 21 days resulted in a sevenfold increase in CO oxidation. A correlation was noted between the CO oxidative activity and the history of previous exposure of soils to high ambient levels of CO. The organisms responsible for CO oxidation apparently comprise a small fraction of the microbial population in the soils. With a roadside soil the oxidation of CO provided the driving force for the assimilation of CO(2). The stoichiometry of the oxidative and assimilatory reactions in soil was in the range of values reported from laboratory studies with CO chemoautotrophs (carboxydobacteria). It is proposed that the population and activity of CO-oxidizing microorganisms increase in response to increasing levels of CO in the environment.

New concepts in viral gastroenteritis.

The use of negative contrast electronmicroscopy of stool suspension in the investigation of the aetiology of childhood gastroenteritis has led to the recognition of a number of candidate viral agents. There is convincing evidence that rotavirus is the single most important cause of community acquired gastroenteritis, and is responsible for some nosocomial outbreaks. The epidemiology of rotavirus acqusition, differential clinical susceptibilities of young and older infants, pathogenesis of disease, mechanisms of immunity and breast milk protection, and the role of different viral serotypes are aspects as yet poorly understood; and attempts to propagate human rotavirus in tissue culture have met with only limited success. Moreover, the aetiologically unaccountable one third of cases of infantile diarrhoea, and the association of enteritis with up to six other virus-like particles add to the complexity of the problem. This review considers the available data from human and animal studies, and based on the experience of ourselves and others comments on the present state of knowledge and trends in continuing research.