Treatment of visceral leishmaniasis with pentavalent antimony and interferon gamma

Acute visceral leishmaniasis is associated with an antigen-specific immunosuppression of mononuclear cells as evidenced by defective in vitro production of interferon gamma. We evaluated treatment with recombinant human interferon gamma in combination with conventional pentavalent antimony therapy in patients with visceral leishmaniasis. Six of eight patients with visceral leishmaniasis (mean duration, 17 months) that had been unresponsive to multiple courses of pentavalent antimony responded to treatment with recombinant human interferon gamma (100 to 400 micrograms per square meter of body-surface area per day) in addition to pentavalent antimony (20 mg per kilogram of body weight per day) for 10 to 40 days. The other two patients improved initially but then relapsed and required treatment with amphotericin B. Eight of nine additional patients with previously untreated severe visceral leishmaniasis were also successfully treated with the combination of interferon gamma and pentavalent antimony. The 14 patients who responded to this regimen had marked improvement in symptoms and in measures of anemia and leukopenia, as well as weight gain, a decrease in spleen size, and an absence or reduction of leishmanias in splenic aspirates. These patients had no recurrence of illness after a mean (+/- SE) follow-up of 8 +/- 1 months. Fever was the only major side effect of interferon gamma. We conclude that the combination of interferon gamma and pentavalent antimony is effective in treating seriously ill patients with refractory or previously untreated visceral leishmaniasis.

The C677T polymorphism in the MTHFR gene is associated with the toxicity of methotrexate in a Spanish rheumatoid arthritis population

OBJECTIVE

Methotrexate (MTX) is the first-choice drug for the treatment of rheumatoid arthritis (RA) patients. However, 30% of RA patients discontinue therapy within 1 year, usually because of adverse effects. Previous studies have reported conflicting results on the association of polymorphisms in the MTHFR gene with the toxicity of MTX in RA. The aim of this study was to assess the involvement of the C677T and A1298C polymorphisms in the MTHFR gene in the toxicity of MTX in a Spanish RA population.

METHODS

The study included retrospectively 468 Spanish RA patients treated with MTX. Single nucleotide polymorphism (SNP) genotyping was performed using the oligonucleotide microarray technique. Allele and genotype association analyses with regard to MTX toxicity and a haplotype association test were also performed.

RESULTS

Eighty-four out of the 468 patients (18%) had to discontinue therapy due to adverse effects or MTX toxicity. The C677T polymorphism (rs1801133) was associated with increased MTX toxicity [odds ratio (OR) 1.42, 95% confidence interval (CI) 1.01-1.98, p = 0.0428], and the strongest association was shown in the recessive model (OR 1.95, 95% CI 1.08-3.53, p = 0.0246). The A1298C polymorphism (rs1801131) was not associated with increased MTX toxicity (OR 0.94, 95% CI 0.65-1.38, p = 0.761). A borderline significant risk haplotype was found: 677T-1298A (OR 1.40, 95% CI 1.00-1.96, p = 0.0518).

CONCLUSION

These results demonstrate that the C677T polymorphism in the MTHFR gene is associated with MTX toxicity in a Spanish RA population.

Sentinel lymph node biopsy in multicentric breast cancer. The experience of the European Institute of Oncology

AIM

To present our experience with sentinel lymph node biopsy (SLNB) performed in patients with multicentric breast cancer.

METHODS

Between May 2001 and May 2004, 42 patients with multicentric breast cancer and a clinically negative axilla underwent lymphatic mapping either by a single subareolar (n = 25) or a double peritumoral/subdermal injection (n = 17) of 99Tc-HSA nanocolloids. The sentinel lymph node (SLN) was evaluated by intraoperative frozen section and axillary dissection was performed only in case of positive SLN.

RESULTS

Mean age was 49 years (range 25-78). Mean number of SLNs identified by lymphoscintigraphy was 1.36 (range 1-5) and mean number of SLNs removed at surgery was 1.55 (range 1-5), with an identification rate of 100%. The mean number of hot spots identified by lymphoscintigraphy was similar in patients who underwent single or double injections (1.36 and 1.35, respectively). In 21 of 42 patients the SLN was positive, and in seven of these 21 patients the SLN was the only positive node. After a median follow-up of 24 months no overt axillary metastases occurred in patients with negative SLN.

CONCLUSIONS

The number of SLNs is not dependent on the number and site of injections. SLNB is our standard procedure for nodal staging in patients with multicentric breast cancer and a clinically negative axilla.

Polyploidy and microsatellite variation in the relict tree Prunus lusitanica L.: how effective are refugia in preserving genotypic diversity of clonal taxa?

Refugia are expected to preserve genetic variation of relict taxa, especially in polyploids, because high gene dosages could prevent genetic erosion in small isolated populations. However, other attributes linked to polyploidy, such as asexual reproduction, may strongly limit the levels of genetic variability in relict populations. Here, ploidy levels and patterns of genetic variation at nuclear microsatellite loci were analysed in Prunus lusitanica, a polyploid species with clonal reproduction that is considered a paradigmatic example of a Tertiary relict. Sampling in this study considered a total of 20 populations of three subspecies: mainland lusitanica (Iberian Peninsula and Morocco), and island azorica (Azores) and hixa (Canary Islands and Madeira). Flow cytometry results supported an octoploid genome for lusitanica and hixa, whereas a 16-ploid level was inferred for azorica. Fixed heterozygosity of a few allele variants at most microsatellite loci resulted in levels of allelic diversity much lower than those expected for a high-order polyploid. Islands as a whole did not contain higher levels of genetic variation (allelic or genotypic) than mainland refuges, but island populations displayed more private alleles and higher genotypic diversity in old volcanic areas. Patterns of microsatellite variation were compatible with the occurrence of clonal individuals in all but two island populations, and the incidence of clonality within populations negatively correlated with the estimated timing of colonization. Our results also suggest that gene flow has been very rare among populations, and thus population growth following founder events was apparently mediated by clonality rather than seed recruitment, especially in mainland areas. This study extends to clonal taxa the idea of oceanic islands as important refugia for biodiversity, since the conditions for generation and maintenance of clonal diversity (i.e. occasional events of sexual reproduction, mutation and/or seed immigration) appear to have been more frequent in these enclaves than in mainland areas.

A controlled trial of pulse cyclophosphamide versus pulse methylprednisolone in severe lupus nephritis

We carried out a prospective randomized trial comparing pulse cyclophosphamide and pulse methylprednisolone in 29 patients with severe lupus nephritis in activity. Patients were assigned to one of two regimens: monthly pulse cyclophosphamide (0.5-1.0 g/m2 body surface area) for 4 months, followed by bimonthly doses for 4 months and quarterly doses for 6 months (14 patients) or pulse methylprednisolone (10-20 mg/kg weight) initially for 3 consecutive days and thereafter in the same intervals as the alternative regimen (15 patients). The mean follow-up was 15 months. Two patients in the cyclophosphamide group and three in the methylprednisolone group died. Renal failure (doubling of serum creatinine) developed in four patients in the cyclophosphamide group compared with five patients in the methylprednisolone group. Cumulative probability of not doubling serum creatinine was similar for cyclophosphamide and methylprednisolone groups (0.66 vs 0.69, respectively, P > 0.20, after 18 months). Cumulative probability of survival without renal failure was also not significantly different (0.61 and 0.63, respectively, P > 0.20, after 18 months). These results suggest that pulse cyclophosphamide is as effective as pulse methylprednisolone in preserving renal function in patients with severe lupus nephritis.

The feasibility of hand-assisted laparoscopic aortic bypass using a low transverse incision

BACKGROUND

Hand-assisted laparoscopy can be used to perform aortoiliac reconstructive procedures. This study aimed to evaluate the safety and feasibility of a hand-assisted aortofemoral bypass in patients with occlusive disease using a low abdominal transverse incision to reduce postoperative respiratory problems.

METHODS

In 18 patients, a modified Pfannenstiel incision was performed. A hand-assist device was inserted, and the aorta was exposed using transperitoneal laparoscopy. Tunneling was performed under laparoscopic control. The anastomosis was always performed proximally to the inferior mesenteric artery. In three patients, the proximal anastomosis had to be performed laparoscopically. The indication for surgery was occlusive disease in 16 patients and a combination of an aneurysm and aortoiliac occlusion in 2 patients.

RESULTS

Conversion was required in one patient (1/18). In 13 patients (13/18), the total operating time did not exceed 180 min, and 61% of the patients (11/18) could be discharged by postoperative day 5. None of the patients died perioperatively (0/18). Complications were observed in six patients (6/18). Only one of these patients had respiratory problems (1/18). The remaining five patients had local complications such as wound healing problems. The anastomosis was sutured laparoscopically in three patients (3/18).

CONCLUSIONS

Hand-assisted laparoscopy can be performed safely using a low transverse abdominal incision. In our experience this laparoscopic access can reduce the incidence of postoperative respiratory problems and incision-related complications.

Acute sporadic non-A, non-B hepatitis in Northeastern Brazil: etiology and natural history

In a 4-year follow-up study, patients with acute sporadic non-A, non-B (NANB) hepatitis were evaluated to determine the etiology and natural history of the disease. Acute hepatitis C virus (HCV) was detected in 13 of 43 (30%) of patients, anti-hepatitis E virus (HEV) IgG in 5 (12%), and 25 (58%) were considered non-A-E. The HCV RNA was detected in all HCV patients but none of the non-A-E cases. The initial clinical and biochemical presentation of the HCV and non-A-E cases was quite similar, although 2 of the non-A-E patients had severe disease. The 5 patients who were found to be anti-HEV IgG-reactive recovered within 6 months of follow-up. Of the 13 HCV cases, alanine transaminase (ALT) levels returned to normal in 7 (53. 8%), while 6 (46.2%) continued to show abnormal ALT after 6 months of follow-up. However, 9 (69.2%) of them remained HCV-RNA-positive, denoting virological/biochemical dissociation. Long-term follow-up showed a reappearance of HCV RNA in 2 of the 4 patients who were in virological remission performing 84% of chronicity rate. Acute non-A-E hepatitis patients were less likely to evolve toward chronicity, as compared with acute HCV cases (16% vs. 84%; P =.0001). Only 4 (16%) of the non-A-E patients were hepatitis G virus (HGV)-RNA-positive. Concerning risk factors for acquiring parenterally transmitted viruses, tattooing was the only one that could be associated with HCV transmission (P =.002). No risk factors could be identified for putative non-A-E virus transmission. Liver biopsies performed for chronic HCV patients showed a variable degree of inflammation, while the non-A-E patients presented less severe histological disease.

Accuracy of physical examination in subacromial impingement syndrome

OBJECTIVE

Shoulder pain is a common complaint, frequently caused by subacromial impingement syndrome (SIS). There are a number of physical examination (PE) manoeuvres that explore the subacromial space. MRI provides an accurate anatomic image of the subacromial space, being the current gold standard in the diagnosis of SIS. The aim of this study is to evaluate the accuracy of the PE in the diagnosis of SIS and/or subacromial-subdeltoid bursitis (SSB) confirmed by MRI.

METHODS

Consecutive outpatients with an episode of shoulder pain were prospectively included in the study. They were examined by a rheumatologist and, within 3 days, an MRI was done. Sensitivity, specificity, positive and negative predictive values, and accuracy of PE manoeuvres were calculated using a 2 x 2 table.

RESULTS

Fourteen males and 16 females were included. All the tests exhibited acceptable sensitivity. As a result Yocum manoeuvre was considered the most sensitive and most accurate for SIS. With regard to SSB, the Gerber test was the most sensitive. The majority of the PE manoeuvres showed low specificity.

CONCLUSIONS

Most PE manoeuvres identify reasonably well subacromial impingement of the shoulder, although, in general, they have low specificity. The Yocum test has the best sensitivity and precision. Our data suggest that imaging techniques should be recommended to better define shoulder lesions.

Outbreaks of cholera-like diarrhoea caused by enterotoxigenic Escherichia coli in the Brazilian Amazon Rainforest

The relationship between enteropathogens and severe diarrhoea in the Brazilian Amazon is poorly understood. In 1998, outbreaks of acute diarrhoea clinically diagnosed as cholera occurred in two small villages localized far from the main cholera route in the Brazilian rainforest. PCR was performed on some enteropathogens and heat-labile (LT) and/or heat-stable (STh) toxin genes, the virulence determinants of enterotoxigenic Escherichia coli (ETEC), were detected. Further characterization of ETEC isolates revealed the presence of two clones, one from each outbreak. One presenting serotype O167:H5 harboured LT-I and STh toxin genes and expressed the CS5CS6 colonization factor. The other, a non-typeable serotype, was positive for the LT-I gene and expressed the CS7 colonization factor. The current study demonstrates the importance of molecular diagnosis in regions such as the Amazon basin, where the enormous distances and local support conditions make standard laboratory diagnosis difficult. Here we also show that the mis-identified cholera cases were in fact associated with ETEC strains. This is the first report of ETEC, molecularly characterized as the aetiological agent of severe diarrhoea in children and adults in the Brazilian Amazon Rainforest.

Prevention of group B streptococcus early-onset neonatal sepsis: comparison of the Center for Disease Control and prevention screening-based protocol to a risk-based protocol in infants at greater than 37 weeks' gestation

OBJECTIVE

To compare the Center for Disease Control consensus guidelines' screening-based strategy to a risk-based strategy as regards the incidence of early-onset group B streptococcus (GBS) infection among term infants.

STUDY DESIGN

A cohort of university hospital prenatal clinic mother-infant pairs who were screened for GBS at 35 to 37 weeks' gestation were compared to a matched control group of unscreened mother-infant pairs from the outreach satellite prenatal clinics who delivered at the same institution during the same time period. GBS screening was carried out with rectovaginal cultures plated on selective media. GBS-positive women received antimicrobial prophylaxis in labor whereas women of unknown GBS status were only treated intrapartum if they had a risk factor for GBS infection. Principal outcome variables included incidence of cases of neonatal early-onset GBS sepsis (blood, urine, or cerebrospinal fluid positive for GBS), incidence of cases of strongly suspected GBS sepsis (culture negative), and incidence of neonatal sepsis with non-GBS organisms.

RESULTS

There were 3164 screened mother-infant pairs who were compared to 2684 unscreened pairs. The incidence of GBS carriage was 13.3%. A random sample of 420 screened women were compared to a matched sample of 407 women of unknown GBS carrier status for characterization of demographics and risk factors. No cases of documented GBS sepsis occurred in the infants of the screened women, but four cases occurred among the infants of the women who did not undergo screening (incidence 1.5/1000) (p = 0.04), only one of whom had a risk factor for GBS infection. Cases of suspected but culture negative sepsis were not more common in the screened population when compared to the unscreened. There was one case of Escherichia coli sepsis in an infant of a mother in the unscreened group.

CONCLUSIONS

GBS screening at 35 to 37 weeks, with intrapartum antimicrobial prophylaxis of carriers, decreased the incidence of neonatal early-onset GBS sepsis and appears to have advantages over treatment based on risk factors alone in term infants.

Termination of obligate anoestrus and induction of fertile ovarian cycles in dogs by administration of purified pig LH

The potential role of LH in the initiation of the follicular phase in dogs was investigated by treating anoestrous bitches with highly purified pig LH (n = 16) or saline (n = 8) three times a day for 7 days, beginning in either early anoestrus (days 94-116 of the cycle) or mid-anoestrus (days 124-145). Treatment with LH induced pro-oestrus within 7 days (n = 16), and oestrus (n = 12) and fertile ovulations (n = 7) at 16 + 3 days, while pro-oestrus in bitches treated with saline did not occur until 46-166 days after the start of treatment. Six of the seven ovulating bitches whelped normal litters. The bitches in which pro-oestrus but not oestrus occurred were all treated in early anoestrus. During treatment, plasma oestradiol in bitches treated with LH increased from 8 + 2 pg ml-1 to 20 + 5 pg ml-1 within 1 day, and reached higher peak values (45 + 7 pg ml-1) (P < 0.05) than those observed in saline-treated controls (9 + 3 ng ml-1). These results demonstrate that LH treatment alone can terminate anoestrus by inducing a normal follicular phase in dogs. The results also suggest that, in normal cyclic bitches, anoestrus is the result of insufficient LH secretion, and that spontaneous pro-oestrus could be the result of increased LH secretion in the presence of already adequate concentrations of FSH.

[Evaluation of a social and environmental indicator used in the identification of lymphatic filariasis transmission in urban centers]

The concept of a "socially organized space" supported by new analytical techniques and mapping of health events has guided innovative methodological developments in public health interventions. This study aimed to evaluate a social/environmental indicator constructed with a scoring methodology to stratify areas in the city of Olinda by different levels of risk for Bancroftian filariasis transmission. The study mapped areas and the location of sample households and identified all residents ages 5 to 65 years as part of the parasitological survey. Among the 3,232 individuals who had blood samples taken, 42 were microfilaremic (1.3% prevalence). Global statistical analysis of filarial case distribution has suggested spatial clustering. Some 85.7% of positive individuals resided in the two strata with the highest transmission risk. The high sensitivity of the proposed indicator for predicting the places where the vast majority of filariasis cases occurred justifies its use in planning and implementing interventions.

Light ray tracing through a leaf cross section

A light ray, incident at about 5 degrees to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are air, cell sap, chloroplast, and cell wall. The above ray is also drawn through the same leaf cross section considering cell wall and air as the only optical mediums. The values of the reflection and transmission found from ray tracing agree closely with the experimental results obtained using a Beckman DK-2A spectroreflectometer.

[Practice guidelines of the Spanish Society of Cardiology. Cardiac and heart-lung transplants]

Cardiac transplantation is the only therapy that is able to substantially modify the natural evolution of patients with severe heart failure, along with angiotensin converting enzyme inhibitors. Nevertheless, because of the limited number of donors, its impact is scarce compared to the magnitude of the problem. Up to the end of 1998, 48,541 orthotopic cardiac transplantations and about 2,510 heart and both lung transplantations have been registered throughout the world. In Spain 2,780 procedures have been performed in the last 15 years. The survival expectations for a transplanted patient is 75% after the first year and 60% the following 5 years. The average duration of the graft is 8 years and 6 months. Cardiac transplantation is indicated for young and middle-age patients with irreversible cardiac process in bad clinical condition, with no other possibility of medical or surgical management and with a limited life expectancy. The major debate when choosing this therapy appears with the critical patients, patients older than 65 years, and some patients with systemic diseases. The great demand of transplantation obliges the teams to enlarge the criteria for donors' acceptance. At the same time, the increase of the knowledge about the transmission of some infections, mainly viral, forces to review those criteria day-to-day. The use of different immunosuppressive strategies pursues the control of rejection. The most commonly used is the so-called triple therapy (cyclosporine-azathioprine and steroids). The use of antilymphocytic antibodies such as cytolytic induction treatment is not unanimously accepted. Some of the new immunosuppressive agents such as myphenolate-mofetil and tacrolimus seem to offer advantages mainly due to their greater potency. Since transplantation is a limited procedure, of which its practise has an effect on the whole health system of a country, a perfect planning and adequacy of the Centers is compulsory, as well as the setting-up of clear rules for the use of donors and priority of transplantation. Finally, the patient must be informed clearly and comprehensively at length of the risks, limitations and expectations of these complex procedures.

Ewe effect: endocrine and testicular changes in experienced adult and inexperienced young Corriedale rams used for the ram effect

Changes in LH, FSH, and testosterone concentrations, testicular firmness and resilience, and scrotal circumference were monitored in 16 Corriedale rams (8 experienced adult and 8 inexperienced young) for 20 days during which they were used to stimulate ewes. The experiment was conducted during November (mid-non-breeding season). Increases (P<0.05) were observed in LH and testosterone concentrations and in testicular firmness and resilience during the first 4 days when rams were in permanent contact with estrual ewes. During the following 13 days, when rams were in contact with non-estrual ewes (i.e. initially estrual ewes were no longer in estrus), LH and testosterone concentrations decreased. When initially anestrous ewes exhibited estrus 17 to 20 days later, concentrations of testosterone increased. Testicular firmness and resilience remained high throughout the period. We conclude that: (1) rams used to stimulate anestrous ewes show an increase in LH and testosterone concentrations beginning at 12 h after joining, and greater concentrations are maintained while estrual ewes and mating are allowed; and (2) estrous and mating activity are probably the most important stimuli for the increase in hormone concentrations.

Allograft loss in renal transplant recipients with Fabry's disease and activated protein C resistance

INTRODUCTION

Fabry's disease is associated with an increased incidence of thrombotic events and rejection. Spontaneous thrombosis of a functioning cadaveric renal allograft in a recipient with Fabry's disease prompted prospective evaluation of all transplant candidates with Fabry's disease for hypercoagulability.

MATERIALS AND METHODS

Transplant candidates with Fabry's disease were tested for hypercoagulability, analyzed for HLA-type and ABO group, and comorbid conditions suggestive of hypercoagulability.

RESULTS

A unique association of Fabry's disease with activated protein C Resistance was documented in a cohort of Caucasian male renal transplant recipients with Fabry's disease. Four of five patients were blood group A and had no significant comorbid conditions suggestive of hypercoagulability. The resistance to activation of protein C (APCR)(+) patients shared HLA loci-B8 and Dr3, although the APCR(-) patients shared HLA loci-B27 and -B38.

CONCLUSIONS

Due to the observed increase in the incidence of APCR in our Fabry's cohort, we suggest screening all patients with Fabry's disease for APCR. Because factor V and factor Va receptors are found on vascular endothelium and peripheral blood monocytes, APCR in the presence of Fabry's disease may be a nonimmunological stimulus for rejection. Analysis of HLA typing in patients with Fabry's disease may further elucidate HLA-based association of Fabry's disease and resistance to activated protein C with the risk of thrombosis and rejection.

Analysis of air temperature changes on blood pressure and heart rate and performance of undergraduate students

BACKGROUND

The increase in air temperature has been associated with human deaths, some of which are related to cardiovascular dysfunctions, and with the reduction of physical and cognitive performance in humans.

OBJECTIVE

To analyze the relationship between blood pressure (BP) and heart rate (HR) and the cognitive performance of students who were submitted to temperature changes in classrooms.

METHODS

The university students answered a survey that was adapted from the Battery of Reasoning Tests over 3 consecutive days at different air temperatures while their thermal state and HR were measured. During those 3 days, BP and HR were evaluated before and after the cognitive test.

RESULTS

The average and final HR increased at high temperatures; the tests execution time was reduced at high temperatures; and the cognitive tests was related to Mean BP at the beginning of the test, the maximum HR during the test and the air temperature.

CONCLUSIONS

The cognitive performance of undergraduate students in the field of engineering and technology will increase while performing activities in a learning environment with an air temperature of approximately 23.3°C (according to their thermal perception), if students have an initial MBP of 93.33 mmHg and a 60 bpm HRmax.

Radioactivity in the environment around past radium and uranium mining sites of Portugal

Measurements of ambient radiation doses and determination of radionuclide concentrations in mining waste and soils were performed in 60 areas of former radium and uranium mining. In several places, mining waste and low-grade uranium ore left on the surface contain radioactivity above regional background. Most of the former mining sites present no enhanced radionuclide concentrations. However, in the mining facilities where the radioactive ore was chemically extracted, mill tailings contain materials with elevated levels of radioactivity, up to 200 times the levels in unaffected soils of the region. Mud from neutralization ponds used to treat acid mine waters contains also elevated radionuclide concentrations. Furthermore, depending on the type of waste, the radioelement composition varies. Environmental rehabilitation measures shall take these differences into account in order to prevent in the long term the radioactive contamination of agriculture soils and water resources, and to ensure adequate radiological protection to the public and to the environment.

Temperature increase at the light guide tip of 15 contemporary LED units and thermal variation at the pulpal floor of cavities: an infrared thermographic analysis

In this study, a comprehensive investigation on the temperature increase at the light guide tip of several commercial light-emitting diode (LED) light-curing units (LCUs) and the associated thermal variation (ΔT) at the pulpal floor of dental cavities was carried out. In total, 15 LEDs from all generations were investigated, testing a quartz-tungsten-halogen (QTH) unit as a reference. The irradiance level was measured with a power meter, and spectral distribution was analyzed using a spectrometer. Temperature increase at the tip was measured with a type-K thermocouple connected to a thermometer, while ΔT at the pulpal floor was measured by an infrared photodetector in class V cavities, with a 1-mm-thick dentin pulpal floor. The relationship among measured irradiance, ΔT at the tip, and ΔT at the pulpal floor was investigated using regression analyses. Large discrepancies between the expected and measured irradiances were detected for some LCUs. Most of the LCUs showed an emission spectrum narrower than the QTH unit, with emission peaks usually between 450 and 470 nm. The temperature increase at the tip followed a logarithmic growth for LCUs with irradiance ≥1000 mW/cm(2), with ΔT at the tip following the measured irradiance linearly (R(2)=0.67). Linear temperature increase at the pulpal floor over the 40-second exposure time was observed for several LCUs, with linear association between ΔT at the pulpal floor and measured irradiance (R(2)=0.39) or ΔT at the tip (R(2)=0.28). In conclusion, contemporary LED units show varied irradiance levels that affect the temperature increase at the light guide tip and, as a consequence, the thermal variation at the pulpal floor of dental cavities.

Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- into π- π- π+

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190  GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1  GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66  GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0))  MeV/c2 and a width of (269±21(-64)(+42))  MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.

Evidence for an involvement of vitellogenin in the steroidogenic activity of rainbow trout (Oncorhynchus mykiss) vitellogenic oocytes

In vivo and in vitro the concentration of vitellogenin (VTG) inside the oocyte can alter VTG production by the liver, modulating the synthesis of 17beta-estradiol (E(2)) by the ovary. To gain a greater insight into this mechanism, the in vitro production of free and conjugated testosterone (T), E(2), and androstenedione (A) by rainbow trout oocytes from the early and middle vitellogenic stage was measured by radioimmunoassay. There was a decreased E(2) production that was greater in September (40%) than October (30%), by the oocytes incubated with the vitellogenic fraction. The production of E(2) conjugated as glucuronide was lower than sulfate (P < 0.05), but similar in control and VTG-incubated oocytes. Levels of free T increased from September to October, and conjugates were both produced at low levels, and no differences were detected between control and incubated VTG oocytes. The decreased synthesis of E(2) by oocytes incubated with VTG was not followed by an increase in the amount of T or conjugated E(2), because there were no differences under the two circumstances. However, there was a reduced synthesis of A with oocytes producing low levels of E(2). These results suggest that the presence of high levels of VTG in the oocyte suppresses the synthesis of A and E(2), affecting the activities of the enzymes C17,20 lyase and aromatase and probably interfering with the heme protein cytochrome P450 which in the ovary catalyses C 17,20 lyase (P450 c17) and aromatase (P450 arom).

The influence of particle size on radionuclide activity concentrations in Tejo River sediments

Sediment samples from Tejo River were analyzed for (228)Ra, (226)Ra, (137)Cs and (40)K by HPGe gamma spectrometry. The activity concentration data were statistically analyzed. The activity concentrations values were in the range of about two orders of magnitude for each radionuclide. The influence of the particle size on the radionuclide concentrations was observed. The different environmental origins of the radionuclides (228)Ra, (226)Ra, (137)Cs and (40)K, in the sediments were demonstrated through correlation analysis. Cluster analysis showed a close relationship between (228)Ra and (226)Ra and a different behavior for (40)K. The data obtained in this study provides useful information on the background radioactivity of the studied area and can be further used for radiological mapping of the Tejo River.