Intra-vaginal prostaglandin E2 versus double-balloon catheter for labor induction in term oligohydramnios.

OBJECTIVE: Compare mechanical and pharmacological ripening for patients with oligohydramnios at term. STUDY DESIGN: Fifty-two patients with oligohydramnios ⩽ 5 cm and Bishop score ⩽ 6 were randomized for labor induction with a vaginal insert containing 10 mg timed-release dinoprostone (PGE2) or double-balloon catheter. The primary outcome was time from induction to active labor. Time to labor, neonatal outcomes and maternal satisfaction were also compared. RESULT: Baseline characteristics were similar. Time from induction to active labor (13 with PGE2 vs 19.5 h with double-balloon catheter; P = 0.243) was comparable, with no differences in cesarean rates (15.4 vs 7.7%; P = 0.668) or neonatal outcomes. The PGE2 group had higher incidence of early device removal (76.9 vs 26.9%; P = 0.0001), mostly because of active labor or non-reassuring fetal heart rate. Fewer PGE2 patients required oxytocin augmentation for labor induction (53.8 vs 84.6% P = 0.034). Time to delivery was significantly shorter with PGE2 (16 vs 20.5 h; P = 0. 045). CONCLUSION: Intravaginal PGE2 and double-balloon catheter are comparable methods for cervical ripening in term pregnancies with oligohydramnios.

Plasmonic control of the shape of the Raman spectrum of a single molecule in a silver nanoparticle dimer.

We study surface-enhanced Raman scattering (SERS) of individual organic molecules embedded in dimers of two metal nanoparticles. The good control of the dimer preparation process, based on the usage of bifunctional molecules, enables us to study quantitatively the effect of the nanoparticle size on the SERS intensity and spectrum at the single molecule level. We find that as the nanoparticle size increases the total Raman intensity increases and the lower energy Raman modes become dominant. We perform an electromagnetic calculation of the Raman enhancement and show that this behavior can be understood in terms of the overlap between the plasmonic modes of the dimer structure and the Raman spectrum. As the nanoparticle size increases, the plasmonic dipolar mode shifts to longer wavelength and thereby its overlap with the Raman spectrum changes. This suggests that the dimer structure can provide an external control of the emission properties of a single molecule. Indeed, clear and systematic differences are observed between Raman spectra of individual molecules adsorbed on small versus large particles.

National prevalence of larval echinococcosis in sheep in slaughtering plants Ovis aries as an indicator in control programmes in Uruguay.

Diagnostic surveys carried out on ovine larval echinococcosis in slaughtering plants at a national level in 1998 made it possible to meet several objectives, i.e. to estimate the existing levels of prevalence, to evaluate the effectiveness of the control actions applied by the Programme against Hydatidosis and to contribute to the improvement of the health information systems for epidemiological surveillance. The work included sheep (Ovis aries), both lambs (2-4 teeth) and adults (6-8 teeth). A random sample was performed among sheep from the plants that slaughter the majority of animals in the country. The sample included 22 animals per herd, and it involved removing their offal (liver, lungs and heart) and processing serial sections at the laboratory. The histopathological studies were performed on the lesions that could not be adequately identified at gross examination, and those that were so small that had to be submitted for confirmation of the diagnosis. Of the 2035 animals that were examined, 1019 were lambs (2-4 teeth) and 1016 were adults (6-8 teeth). The prevalence of larval echinococcosis was 7.7% in lambs and 18.0% in adults. The overall prevalence in the liver was 8.5 and 8.0% in the lungs. As to the characteristics of the morphologic structures of the larvae, in younger animals 29% of the lesions were calcified, and 71.0% were hyaline, while in older animals the proportions were 34.4% calcified versus 65.6% hyaline. Other conditions found in the liver parenchyma included: white stain (0.8%), caseous lymphadenitis (3.0%), abscess (0.4%), larvae of Taenia hydatigena (5.1%), Fasciola hepatica (3.9%). And 1.7% of the animals presented larvae of Taenia ovis in the cardiac muscle. Previous surveys carried out in 1994 using the same methodology showed a prevalence of 15.2% in 2-4 teethed animals and 33.9% in 6-8 teethed animals, thus confirming that rates have decreased by 49.6 and 47.0%, respectively. The data obtained reflect the reduction of areas contaminated with eggs of Echinococcus granulosus, which would cause a loss in immunity against this parasite after a certain time. Prevalence of larvae T. hydatigena and T. ovis could change if more sites were considered, a fact that was confirmed in studies carried out in our country. The species O. aries must be used as an indicator in the control programmes, especially in the category of 2-4 teethed lambs. The fact they are not as frequent in our market must be considered; in 1998 they accounted for only 3.0% of the total numbers of animals.

Slow fluctuations in enhanced Raman scattering and surface roughness relaxation.

We propose an explanation for the recently measured slow fluctuations and "blinking" in the surface-enhanced Raman scattering spectrum of single molecules adsorbed on a silver colloidal particle. We suggest that these fluctuations may be related to the dynamic relaxation of the surface roughness on the nanometer scale and show that there are two classes of roughness with qualitatively different dynamics. The predictions agree with the measurements of surface roughness relaxation. Using a theoretical model for the kinetics of surface roughness relaxation in the presence of charges and optical electrical fields, we predict that the high-frequency electromagnetic field increases both the effective surface tension and the surface diffusion constant and thus accelerates the surface smoothing kinetics and time scale of the Raman fluctuations in a manner that is linear with the laser power intensity, while the addition of salt retards the surface relaxation kinetics and increases the time scale of the fluctuations. These predictions are in qualitative agreement with the Raman experiments.

Control of Echinococcus granulosus in Uruguay: evaluation of different treatment intervals for dogs.

This study attempted control of transmission of Echinococcus granulosus from dogs to sheep in different areas in the Department of Florida, Uruguay, by treating dogs with praziquantel at intervals of 6, 12 and 16 weeks. The 6-week interval was based on the prepatent period of infection with E. granulosus, the 12- and 16-week intervals were based on the rate of reinfection with tapeworms in dogs in the area. Dogs had become reinfected with E. granulosus between 2 and 4 months after treatment, whereas they became reinfected with the Taenia spp. tapeworms within 2 months of treatment. One year after the start of treatments sentinel lambs were born and grazed the farms in the three treatment areas. Approximately, 15 months later when the sentinel lambs were killed and examined for parasites the six weekly treatments had stopped the transmission of E. granulosus to the sentinel lambs. Treatment of dogs at 12- and 16-week intervals failed to stop transmission of E. granulosus but both the numbers of farms and the numbers of sheep infected with E. granulosus were lower where dogs received 12 weekly treatments compared with dogs receiving 16 weekly treatments and a fourth area where dogs had received no treatments (chi(2)P=0.002). Lambs continued to become infected with the Taenia spp. tapeworms in all the areas. Control was complicated by large changes in the dog population. From a starting population of 1164 dogs in the three treated areas, 832 new dogs, most of these adult hunting dogs, entered the population and 793 dogs were lost from the population.

Microenviromental investigation of polymer-bound fluorescent chelator by fluorescence microscopy and optical spectroscopy.

8-Hydroxyquinoline-5-sulfonic acid (HQS) was immobilized onto a strong-base anion-exchange resin AG MP-1 for the purpose of microenvironment investigation, resin characterization, and possibly sensing cadmium. The maximum loading of HQS was found to be 0.9340 mmol/g of AG MP-1. A plateau for Cd complex capacity was already obtained for 0.5500 mmol of HQS/g of AG MP-1. A minicolumn experiment showed an influence of influent Cd concentration on column capacity. IR and Raman spectra proved an electrostatic mode for HQS immobilization and Cd complex formation. UV spectroscopy showed significant differences between solution and solid state for both HQS and Cd complex. A fluorescence microscopy technique was used for fluorescence spectral measurement, microdistribution imaging, and study of photobleaching of HQS and the HQS-Cd complex in the resin phase. The fluorescence of immobilized HQS was found to be red-shifted with regard to the solid-state HQS. The microdistribution of uncomplexed and Cd-complexed AG MP-1-HQS was directly visualized by fluorescence imaging, showing a nonuniform distribution. Cadmium complexation modifies the fluorescence emission of uncomplexed AG MP-1-HQS, exhibiting an increased and red-shifted emission. Significant photobleaching of the fluorescence from the Cd complex was recorded, indicating the occurrence of photochemical reactions within the microenvironment of the resin phase.

Rates of reinfection with Echinococcus granulosus, Taenia hydatigena, taenia ovis and other cestodes in a rural dog population in Uruguay.

A survey was undertaken to determine both the prevalence of, and reinfection rates with Echinococcus granulosus and other cestodes in the Department of Florida, Uruguay. Baseline prevalence was determined in 303 rural dogs which then, in 4 groups, were re-examined 2, 4, 8 or 12 months later. Baseline prevalences for E. granulosus, Taenia hydatigena, Taenia ovis and Dipylidium caninum were 13.2, 13.9, 2.3 and 13.2%, respectively. The frequency distribution of E. granulosus was over-dispersed. Dogs in the population became infected with E. granulosus between 2 and 4 months after treatment (prevalences at 2, 4, 8 and 12 months were 0, 6.8, 18.6 and 27.9%, respectively). There was no indication that there was a predisposition of dogs to infection with the Odds Ratio being 1.0. Dogs were infected with T. hydatigena and D. caninum within 2 months and with T. ovis between 2 and 4 months after treatment. The implications of these different rates of reinfection in the dog population on anthelmintic control strategies against cystic echinococcosis are discussed.

Transmission dynamics of Echinococcus granulosus, Taenia hydatigena and Taenia ovis in sheep in Uruguay.

A base-line survey was carried out on the transmission dynamics of Echinococcus granulosus, Taenia hydatigena and Taenia ovis in sheep in the Department of Florida, Uruguay. Mean life expectancy at birth of the sheep population in this Department was estimated at 3.5 and 4.8 years for male and female sheep, respectively. Both intensity and prevalence of E. granulosus infection increased with age providing no evidence that immunity was acquired in the population. This revealed that E. granulosus was only relatively stable and in an equilibrium endemic steady state with an estimate of the basic reproduction ratio (Ro) of about 1.2. The mature larval population in sheep was over-dispersed with parameter k, from fitting a negative binomial, being 0.199 and 0.556 in 42- and 54-month-old sheep, respectively. The mean number of cysts increased by 1.05 cysts per year and the infection pressure was calculated as 0.174 infections per year, implying that each infection consisted of 693.6 eggs to produce 6.03 cysts. Neither intensity nor prevalence of infection with T. hydatigena or T. ovis increased with age. This indicated that immunity was acquired to reinfection by both parasites and they were in an equilibrium hyperenedemic steady state with an estimated Ro of 4.2-5.8. Viability and fertility of E. granulosus, and viability of T. hydatigena cysts in the older age groups were low. The effects of the different transmission levels of the parasites on potential control strategies are discussed.

Picosecond fluorescence spectroscopy of a single-chain class I major histocompatibility complex encoded protein in its peptide loaded and unloaded states.

The tryptophan fluorescence properties of two different peptide complexes of the single-chain H-2Kd (SC-Kd) were studied by means of the single-photon counting technique. The latter enables time-resolved measurements of fluorescence intensity and anisotropy decay parameters relevant to structural and dynamic properties of proteins. While the isolated SC-Kd molecules in their 'original' purified form represent the unloaded state, i.e., containing endogenous low-affinity peptides, the loaded SC-Kd protein is obtained by introducing well-defined high-affinity peptides that replace the low-affinity ones. These two SC-Kd forms were found to exhibit different time-resolved tryptophan emission patterns; the unloaded complexes show a slightly faster fluorescence intensity decay rate than the loaded one. Three well-resolved time domains were distinguished in the anisotropy decay course of both forms: a short one in the picosecond range, an intermediate one of several nanoseconds, and a long one spanning several dozens to hundreds of nanoseconds. They are assigned to superposition contributions of (short- and long-distance) non-radiative energy transfer processes, to motions of the tryptophans, and to rotation of the whole protein globule. In the loaded SC-Kds, the first two processes were found to be attenuated. It is therefore suggested that upon binding of high-affinity peptides, the SC-Kd structure becomes more compact and certain tryptophans become less accessible to quenchers. The faster anisotropy decay observed in the unloaded form reflects both an enhancement in the energy-transfer between the tryptophans and an acceleration of their motions.(ABSTRACT TRUNCATED AT 250 WORDS)

Transmembrane ammonium sulfate gradients in liposomes produce efficient and stable entrapment of amphipathic weak bases.

Gradients of ammonium sulfate in liposomes [(NH4)2SO4]lip. > [(NH4)2SO4]med. were used to obtain 'active' loading of amphipathic weak bases into the aqueous compartment of liposomes. The loading is a result of the base exchange with the ammonium ions. This approach was applied to encapsulate anthracyclines and acridine orange inside the liposomes at very high efficiency (> 90%). Doxorubicin was accumulated in the aqueous phase of the liposomes where it reached a level as high as 100-fold the doxorubicin concentration in the remote loading medium. Most of the intraliposomal doxorubicin was present in an aggregated state. The active entrapment and loading stability were dependent on liposome lipid composition, lipid quality, medium composition and temperature, as well as on the pKa and hydrophobicity of the base. The ammonium sulfate gradient approach differs from most other chemical approaches used for remote loading of liposomes, since it neither requires preparation of the liposomes in acidic pH, nor to alkalinize the extraliposomal aqueous phase. The stability of the ammonium ion gradient is related to the low permeability of its counterion, the sulfate, which also stabilizes anthracycline accumulation for prolonged storage periods (> 6 months) due to the aggregation and gelation of anthracycline sulfate salt.

Domain motions in phosphoglycerate kinase: determination of interdomain distance distributions by site-specific labeling and time-resolved fluorescence energy transfer.

3-Phosphoglycerate kinase is composed of two globular domains separated by a wide cleft. The substrate binding sites are situated on the inner surfaces of the two domains. By analogy to other kinases, it has been postulated that the catalytic mechanism of phosphoglycerate kinase involves a hinge bending domain motion that brings the substrates together to allow phosphoryl transfer. To characterize this large-scale conformational change, as well as the dynamics of the unliganded enzyme in solution, we have applied site-directed mutagenesis and time-resolved nonradiative energy transfer techniques. Two genetically engineered cysteines (Cys-135 and Cys-290), one in each of the two domains, were covalently labeled with a donor and acceptor pair of fluorescent probes. Analysis of subnanosecond fluorescence decay curves yielded the equilibrium distribution of interdomain distances. In the absence of substrates, the distribution of distances between the two labeled sites was very broad, with a full width at half maximum estimated as 20 A or broader, indicative of a large number of conformational substates in solution. The mean distance, 31.5 +/- 1 A, was 8 A smaller than in the crystal structure. Upon addition of ATP alone or of ATP and 3-phosphoglycerate, the average distance increased to 38 +/- 1 A and the width of the distribution decreased. Addition of 3-phosphoglycerate alone induced a similar but smaller change. The rate of conformational state fluctuations (interconversion between states) was found to be slow on the nanosecond time scale, as expected for a protein with a relatively large interdomain contact area.

Effect of lithium carbonate on lateralized cognitive functions.

The effect of lithium carbonate on lateralized cognitive functions was studied by asking a patient suffering from a manic-depressive disorder to repeatedly recognize a given series of digits delivered dichotically while varying the dosage of lithium carbonate intake. The data showed that, whereas digit recognition from the right ear (left hemisphere) was about the same across tests, recognition from the left ear (right hemisphere) varied systematically with dosage variations. Specifically, it was found that an increase in dosage of lithium carbonate was associated with a decrease in recognition from the left ear. These data might indicate unilateral hemispheric effects of lithium carbonate on the dysfunctional right hemisphere of patients suffering from bipolar affective disorders. Clinical implications of the findings of the present case study are also discussed.

Alteration of T cell subsets and induction of suppressor T cell activity in normal subjects after exposure to sunlight.

The effects of exposure to natural sunlight on the immune system were studied in 15 normal human subjects. Exposure was for 1 hr each day for 12 days over 2 wk and tests were carried out before, on completion, and 2 wk after completion. In comparison to concurrent studies on 13 age- and sex-matched controls, sun-exposed subjects had a significant increase in their circulation of T cells recognized by OKT8 monoclonal antibodies and a decrease in OKT4 positive T cells. Suppressor T cell activity measured in pokeweed mitogen-stimulated cultures of T and B cells was significantly increased against IgG and IgM production. These changes were still evident in many of the subjects 2 weeks after completion of the sun exposure. A trend for depression of natural killer cell activity against a melanoma target cell was noted in the present study, but this did not appear as marked as that noted previously in subjects exposed to radiation in solariums. The differences between the effect of radiation from solariums and natural sunlight on the immune system may result from the higher dosage of UV-A in radiation from solariums. The results suggest that exposure to sunlight may favor the induction of suppressor pathways in response to antigenic stimuli and that this may limit immune responses against tumor cells such as melanoma. They support the idea from animal studies that systemic changes in the immune system may be an important factor in the association of UV radiation with malignancy.

Immunological effects of solarium exposure.

Normal volunteers underwent a standard course of treatment to acquire a suntan in a commercial solarium, and tests of immune function were carried out before, on completion, and 2 weeks after completion of radiation exposure. Compared with age and sex matched concurrent controls, the test subjects had reduced skin test responses to dinitrochlorobenzene (DNCB), slightly reduced blood lymphocyte numbers, and changes in the proportion of lymphocyte subpopulations. This included a relative increase in total (OKT3+) T-cell numbers which was attributable to an increase in the OKT8+ suppressor/cytotoxic subset of T cells. OKT4+ helper T cells were reduced and there was a significant decrease in the OKT4/OKT8 ratio. Other changes included a significant increase in suppressor T-cell activity against IgG production in vitro and depression of natural killer cell activity. These changes were still present in some subjects 2 weeks after solarium exposure.