Domain wall propagation and pinning induced by current pulses in cylindrical modulated nanowires

The future developments in 3D magnetic nanotechnology require the control of domain wall dynamics by means of current pulses. While this has been extensively studied in 2D magnetic strips (planar nanowires), few reports on this exist in cylindrical geometry, where Bloch point domain walls are expected to have intriguing properties. Here, we report an investigation on cylindrical magnetic Ni nanowires with geometrical notches. An experimental work based on synchrotron X-ray magnetic circular dichroism (XMCD) combined with photoemission electron microscopy (PEEM) indicates that large current densities induce domain wall nucleation, while smaller currents move domain walls preferably antiparallel to the current direction. In the region where no pinning centers are present, we found a domain wall velocity of about 1 km s^-1. Thermal modelling indicates that large current densities temporarily raise the temperature in the nanowire above the Curie temperature, leading to nucleation of domain walls during the system cooling. Micromagnetic modelling with a spin-torque effect shows that for intermediate current densities, Bloch point domain walls with chirality parallel to the Oersted field propagate antiparallel to the current direction. In other cases, domain walls can be bounced from the notches and/or get pinned outside their positions. We thus found that current is not only responsible for domain wall propagation, but also is a source of pinning due to the Oersted field action.

P–708 Comparison of reproductive outcomes after progestin-primed ovarian stimulation with dydrogesterone versus cetrorelix to inhibit spontaneous ovulation in oocyte donation

Study question

Is dydrogesterone (DYG) equivalent compared to cetrorelix with respect to clinical pregnancy rate, ongoing pregnancy rate and live birth rate in oocyte donation (OD) cycles?

Summary answer

DYG is comparable to cetrorelix in terms of clinical pregnancy, but higher rates of ongoing pregnancy and live birth were observed in the DYG group

What is known already

Progestin-primed ovarian stimulation (PPOS) is an ovarian stimulation regimen based on a freeze-all strategy using progestin as an alternative to GnRH analog for suppressing a premature LH surge. DYG is an oral progestin that has been studied in PPOS protocols.

Published reports indicate that length of ovarian stimulation, dose of gonadotrophin needed and number of MII retrieved from PPOS cycles are comparable to short protocol of GnRH agonists during OD cycles. However, while some studies noted no differences in terms of live births, worse pregnancy rates have been reported in recipients of oocytes from PPOS cycles compared to GnRH antagonists.

Study design, size, duration

Prospective controlled study to assess the reproductive outcomes of OD recipients in which the donors were subjected to the DYG protocol (20mg/day) compared with those subjected to the short protocol with cetrorelix (0.25 mg/day) from Day 7 or since a leading follicle reached 14 mm. The OD cycles were triggered with triptoreline acetate and the trigger criterion was ≥3 follicles of diameter >18mm.

Participants/materials, setting, methods

202 oocyte donors were included, 92 under DYG and 110 under cetrorelix. The study was performed in a private infertility center between January 2017 and December 2020.

The main outcome included the rates of clinical pregnancy, ongoing pregnancy and live births. Secondary outcomes included the number of oocytes retrieved, number of MII, fertilization rate, length of stimulation and total gonadotropin dose. Differences were tested using a Student’s t-test or a Chi2 test, as appropriate.

Main results and the role of chance

Compared to antagonist cycles, cycles under DYG had fewer days of stimulation (9.9 ± 0.9 vs. 10.8 ± 1.1, p<.001) and a lower total gonadotropin dose (1654 ± 402.4 IU vs. 1844 ± 422 IU, p<.001). The number of MII retrieved was no different: 16.9 (SD 6.2) with DYG and 15.4 (SD 5.8) with cetrorelix (p = 0.072). Recipients and embryo transfer (ET) characteristics were also similar between groups. The mean number of MII assigned to each recipients was 6.7 (SD 1.8) in DYG and 6.6 (SD 1.7) in cetrorelix (P = 0.446). The fertilization rate was 66.2% in DYG versus 67.6% in cetrorelix (P = 0.68). Regarding the reproductive outcomes, the overall clinical pregnancy rate in DYG group (65/87: 74.7%) and cetrorelix group (66/104: 63.4%) (p = 0.118) was similar. Meanwhile, the DYG group compared to cetrorelix group had higher rates of ongoing pregnancy (63.2% vs 45.1%; p = 0.014) and live births (54,9% vs 37.8%; p = 0.040).

Limitations, reasons for caution

These results should be evaluated with caution. The limitations of this study include the limited number of participants enrolled and the limited data on pregnancy outcomes. A randomized controlled trial is necessary to provide more evidence on the efficacy of the DYG protocol.

Wider implications of the findings: The efficacy of PPOS protocol compared to GnRH-antagonist protocol in terms of reproductive outcomes has been little studied. PPOS using DYG yields comparable clinical pregnancy rates compared to cetrorelix in OD cycles. The differences found regarding the rates of ongoing pregnancy and live births should be further investigated.

Trial registration number

Not applicable

POS0394 NAD+ BOOSTERS REESTABLISH THE ALTERED NAD+ METABOLISM OF LEUKOCYTES FROM RHEUMATOID ARTHRITIS PATIENTS IMPROVING THEIR OXIDATIVE, APOPTOTIC AND INFLAMMATORY STATUS

Background:

NAD+ is an important cofactor and second messenger for multiple cellular processes that exhibits antioxidant, anti-apoptotic and anti-inflammatory properties. Pre-clinical studies in animal models of Rheumatoid Arthritis (RA) have demonstrated the therapeutic potential of NAD+ boosters in the control of the disease activity. However, to date no studies have been set up to evaluate the NAD+ metabolism and the therapeutic effects of NAD+ boosters in RA patients.

Objectives:

1- To study the NAD+ metabolism in RA patients and its association with key clinical features. 2- To evaluate the effect of anti-TNF therapy in the NAD+ metabolism.

3- To analyze the beneficial effects of NAD+ boosters in leukocytes from active RA patients.

Methods:

Plasma and PBMCs were purified from 100 RA patients and 50 healthy donors (HDs). Moreover, an additional cohort of 50 RA patients treated with Anti-TNF therapy was analyzed before and after 6 months of treatment. NAD+ levels were determined by using the NAD/NADH-Glo Assay. NAD+-consuming genes expression were analyzed by RT-PCR. In parallel, PBMCs from eight HDs and eight active RA patients were treated ex vivo with 1 mM of NAD+ boosters including nicotinamide (NAM), nicotinamide riboside (NR), and nicotinamide mononucleotide (NMN). After 24 hours, intracellular reactive oxygen species (ROS) levels (DFCHDA) and the percentage of apoptotic PBMCs (annnexin V/PI) were assessed by flow cytometry. Lastly, a panel of key pro-inflammatory genes were evaluated by RT-PCR.

Results:

NAD+ and NADH levels were significantly reduced in plasma and PBMCs of RA patients compared with HDs and directly related to disease activity (DAS28, CDAI, SDAI). Accordingly, the expression levels of genes involved in the consumption of NAD+ such as SIRT-1, CD38 and PARP-1 were found up-regulated in PBMCs from RA patients. Anti-TNF therapy for 6 months restored the altered NAD+ levels towards those showed by HDs. Furthermore, the clinical response promoted by Anti-TNF therapy (changes in DAS28) correlated with changes in NAD+ levels. The in vitro treatments of PBMCs isolated from active RA patients with NAD+ boosters significantly increased the NAD+ levels and promoted a deep reduction of intracellular ROS levels, the percentage of apoptotic cells and the expression levels of key inflammatory mediators, such as IL-6, IL-8, IL-1ß, TNF-α, CCL2, IL-23, and STAT-3.

Conclusion:

1. NAD+ metabolism is altered and associated with the disease activity of RA patients, involving both, reduced NAD+ levels and increased expression of NAD+-consuming genes. 2. Anti-TNF therapy restored NAD+ levels, which were directly linked to the clinical effectiveness. 3. NAD+ boosters reduced the oxidative, apoptotic and inflammatory profiles of RA leukocytes through the parallel increase of intracellular NAD+ levels. Thus, NAD+ boosters might be considered novel therapeutic tools for RA patients.

Acknowledgements:

Supported by PI18/00837, RIER RD16/0012/0015, RTI2018-100695-B-I00, P18-RT-4264 and CVI276, co-funded with FEDER.

Disclosure of Interests:

None declared

Hematotoxicity of magnetite nanoparticles coated with polyethylene glycol: in vitro and in vivo studies

Hematotoxicity of magnetite nanoparticles with different coatings has been evaluated by determining their safety in vitro and in vivo in a rat model up to 30 days.

Application of super-twisting observers to the estimation of state and unknown inputs in an anaerobic digestion system

This paper presents the estimation of the unknown states and inputs of an anaerobic digestion system characterized by a two-step reaction model. The estimation is based on the measurement of the two substrate concentrations and of the outflow rate of biogas and relies on the use of an observer, consisting of three parts. The first is a generalized super-twisting observer, which estimates a linear combination of the two input concentrations. The second is an asymptotic observer, which provides one of the two biomass concentrations, whereas the third is a super-twisting observer for one of the input concentrations and the second biomass concentration.

A single oral dose of fructose induces some features of metabolic syndrome in rats: role of oxidative stress

BACKGROUND AND AIMS

To determine if a single oral dose of fructose to rats reproduces some features of metabolic syndrome observed after chronic administration and if so, to investigate its mechanisms.

METHODS AND RESULTS

Systolic blood pressure was measured in rats before and after oral administration of fructose, and in animals pretreated with lipoic acid, methyldopa, losartan or streptozotocin. In other rats, glucose, insulin, uric acid, and insulin sensitivity index, were determined before and after fructose or lipoic acid plus fructose. Glutathione was measured in liver before and after fructose administration. In aortic rings from other rats, incubation with mannitol, fructose, or fructose plus lipoic acid was evaluated on the relaxation by acetylcholine. Fructose produced a moderate increase in blood pressure, which was prevented by lipoic acid or streptozotocin. Methyldopa and losartan decreased the pressor response minimally. Fructose increased oxidized glutathione, plasma glucose, insulin and uric acid, and diminished the insulin sensitivity index, and the reduced glutathione. Lipoic acid prevented hyperglycemia and hyperuricemia, and improved the insulin sensitivity index. Finally, endothelial dysfunction was prevented by lipoic acid.

CONCLUSION

A single dose of fructose reproduces some of the features of metabolic syndrome, most changes were caused by oxidative stress and insulin resistance.

Long-term bladder function, fertility and sexual function in patients with posterior urethral valves treated in infancy

OBJECTIVE

To address the issue of sexual function and fertility in PUV patients.

PATIENTS AND METHODS

Of 47 patients (age > 18 years) treated for PUV in infancy 28 were contactable. They were sent a standard questionnaire requesting details on voiding dysfunction symptoms, and experience of erection, orgasm and ejaculation.

RESULTS

Of the 28, 16 (mean age 24 years) returned the questionnaire. Voiding frequency ranged from 3 to 10 times per day (mean = 5). Two patients had occasional mild diurnal incontinence but none had symptoms of overactivity. Three patients had a weak urinary stream. Renal function was normal in 9, 4 had a glomerular filtration rate <80 ml/min/1.73 m(2), and 3 had undergone renal transplant. Erections and orgasm were experienced by the 15 patients who responded to these questions, with 4 reporting mild or medium erectile dysfunction and 1, on dialysis, reporting slow ejaculation. Post-masturbation samples of semen and urine were collected from 6 patients. One had an alkaline pH, high percentage of immotile sperm and low sperm count. Another had a high concentration of abnormal forms, and seminal fluid was present in the urine of 3 patients.

CONCLUSIONS

In long-term follow-up, 44% of PUV patients develop chronic renal failure or end-stage renal disease, but bladder dysfunction symptoms are infrequent. Sexual function is mostly normal. Total semen counts and motility are compatible with paternity in most patients.

Does mixing affect the setting of injectable bone cement? An ultrasound study

Experimental calcium sulphate bone cement has been tested by ultrasounds to characterise its progressive setting through the evolution of several acoustic properties. The acoustic impedance z(t), the density rho (t) and the speed of sound c(t) versus the curing time have been monitored during the viscous-to-solid transition of the cement as a function of different mixing conditions. Injectability tests were also performed and the results have been related to the acoustic properties measured previously. It has been observed that further mixing after cement's constituency, and before the initial setting time of the cement, drastically affects both the characteristic setting times and the injectability of the cement.

Evaluation of an optimal fill strategy to biodegrade inhibitory wastewater using an industrial prototype discontinuous reactor

This work presents the results and discussions of the application of an optimally controlled influent flow rate strategy to biodegrade, in a discontinuous reactor, a synthetic wastewater constituted by 4-chlorophenol. An aerobic automated discontinuous reactor system of 1.3 m3, with a useful volume of 0.75 m3 and an exchange volume of 60% was used. As part of the control strategy influent is fed into the reactor in such a way as to obtain the maximal degradation rate avoiding inhibition of microorganisms. Such an optimal strategy was able to manage increments of 4-chlorophenol concentrations in the influent between 250 and 1000 mg/L. it was shown that the optimally controlled influent flow rate strategy brings savings in reaction time and flexibility in treating high concentrations of an influent with toxic characteristics.

Gene polimorphisms and biological factors as possible predictors for patients with pleural metastatic breast cancer

10671

Background: Pronosis of breast cancer varies widely in patients with similar clinical features. Therefore, we investigated other factors with possible prognostic value. The CYP17 gene has a polimorphism related to a increased susceptibility to breast cancer (single T; A1 allele to C; A2 allele). ( Mitrunen et al. Cancer Epidemiol Biomarkers Prev 2000,9;12;1343–8). On the other hand, it has been found in the MTHFR gene a common C-T substitution at nucleotide 677 that is associated with reduced enzyme activity and increased risk of breast cancer (Capmbell et al., Breast Cancer Research 2002;4,6:R14). Other genes such as GSTT1 and GSTM1 variant genotypes have a controversial association to breast cancer. We have analyzed the genotype and biological factors in a group of patients with pleural metastatic cancer of the breast and compared it to a control group of women with no cancer. Methods: Forty-six patients with breast cancer and forty women as controls were includes in the study. Age at diagnosis of the primary tumor, TNM staging, interval free of disease, estrogen and progesteron receptors, Ki67, p53 and Her-2neu expression were recorded, as well as survival from the time of diagnosis and polimorphism of CYP17, MTHFR, GSTT1 and GSTM1 genes. Results: Mean survival differed significantly between patients having pleural effusion as the first site of relapse as compared to those with other sites of relapse (28’9 vs 11’9 months, p = 0’004). A high Ki67 expression correlated best with longer survival after talc pleurodesis. We detected a high frequency in the CYP17 A2 variant genotype in patients with metastatic breast cancer compared to the control group. As for MTFHR gene, we found a high frequency for the T/T genotypes variant in breast cancer group. No significant differences between control and cancer group were found in either GSTT1 and GSTM1 gene variations. Conclusions: Genotype and biological factors, such as factors investigated in this study, play an important role as predictors for patients with pleural metastatic breast cancer.

No significant financial relationships to disclose.

Hypoacusis detector for evaluation of scholars in field

Hypoacusis on scholars has become not only a problem but also an indicator when attention disorders or misunderstood instructions from teachers are observed. A primary detection of hypoacusis, in particular in speech range, can help scholars, parents and teachers to improve or correct the learning process. A hypoacusis detector has been developed to be applied in field. This device is based on the generation of three tones and three sound level pressures in the speech range. Both the laboratory evaluation and a case of study results are reported in this document.

Optimal biodegradation of phenol and municipal wastewater using a controlled sequencing batch reactor

This work presents the results of the application of an optimally controlled influent flow rate strategy to biodegrade, in a discontinuous reactor, a mixture of municipal wastewater and different concentrations of phenol when used as a toxic compound model. The influent is fed into the reactor in such a way to obtain the maximal degradation rate avoiding the inhibition of the microorganisms. Such an optimal strategy was able to manage increments of phenol concentrations in the influent up to 7000 mg/L without any problem. It was shown that the optimally controlled influent flow rate strategy is a good and reliable tool when a discontinuous reactor is applied to degrade an industrial wastewater.

Biodegradation of high 4-chlorophenol concentrations in a discontinuous reactor fed with an optimally controlled influent flow rate

This work presents the results of the application of an optimally controlled influent flow rate strategy to biodegrade, in a discontinuous reactor, high concentrations of 4-chlorophenol used as toxic compound model. The influent is fed into the reactor in such a way as to obtain the maximal degradation rate, thus avoiding the inhibition of the microorganisms. The optimal strategy was able to manage increments of toxic concentrations in the influent up to 7,000 mg 4CP/L without any problem. It was shown not only that higher concentrations of toxic could be treated, but also that a reduction in degradation time (around 52%) and in the supplied air volume was obtained.

Docetaxel and high-dose epirubicin as neoadjuvant chemotherapy in locally advanced breast cancer

PURPOSE

Epirubicin and docetaxel are two of the most active drugs against breast carcinoma. As the achievement of a pathological complete response (pCR) is important for survival of patients with locally advanced disease, we used both drugs as neoadjuvant chemotherapy.

PATIENTS AND METHODS

Women with locally advanced or inflammatory breast cancer received epirubicin 120 mg/m2 followed by docetaxel 75 mg/m2, both on day 1, every 21 days for four cycles. Lenograstim was administered for 10 days in all cycles.

RESULTS

Of 51 patients included, 50 received a total of 188 cycles, with a median of 4 per patient. The median age was 47 years, tumour stage was IIIA in 14 patients and IIIB in 36. Oestrogen receptors were positive in 65% of tumours. There were 10 clinical complete responses (20%) and 29 partial responses (58%). Surgery consisted of mastectomy in 40 patients and tumorectomy in 6. After surgery, 9 pCR were recorded (18%). One patient progressed and died soon after the end of chemotherapy. After a median follow-up of 22 months, the median disease-free survival was 33.7 months. Grade 3/4 neutropenia was observed in 32% of patients, anaemia in 6%, and thrombocytopenia in 4%. Five patients had febrile neutropenia. There were no toxic deaths or grade 4 nonhaematological toxicities.

CONCLUSIONS

Docetaxel plus high-dose epirubicin showed promising activity in patients with locally advanced and inflammatory breast cancer, at the cost of moderate toxicity.

Tissue factor expression is decreased in monocytes obtained from blood during Mediterranean or high carbohydrate diets

BACKGROUND

Mediterranean and high carbohydrate diets play a dominant role in the prevention of atherosclerosis as a result of their lipid lowering effect. However, diets can also have a protective effect in other ways, such as modulating tissue factor expression in circulating monocytes.

METHODS AND RESULTS

Forty-one subjects participated in this randomised crossover study consisting of three dietary periods: a saturated fat enriched diet (SFA), a low fat and high carbohydrate diet (CHO), and a Mediterranean diet. Plasma levels of total cholesterol, triglycerides, low density lipoprotein (LDL-C) and high density lipoprotein (HDL-C) were determined at the end of each dietary period, as was the expression of tissue factor (TF) in circulating monocytes isolated from blood samples. Total cholesterol, LDL-C, HDL-C and TF expression were lower after the Mediterranean and high carbohydrate diets than after the SFA diet, and there was a positive correlation between LDL-C levels and monocyte TF expression.

CONCLUSIONS

High carbohydrate and Mediterranean diets reduce the expression of TF in circulating monocytes.

Postprandial lipemia is modified by the presence of the polymorphism present in the exon 1 variant at the SR-BI gene locus

It has recently been reported that carriers of the less common allele at the scavenger receptor class B type I (SR-BI) exon 1 polymorphism are more susceptible to the presence of saturated fatty acid in the diet because of a greater increase in LDL cholesterol. Our aim was to determine if this polymorphism could also influence postprandial lipoprotein metabolism, because the SR-BI has been described as a possible mediator in the intestinal absorption of triacylglycerols. Forty-seven normolipidemic volunteers who were homozygous for the E3 allele at the APOE gene were selected [37 homozygous for the common genotype (1/1) at the SR-BI exon 1 polymorphism and 10 heterozygous (1/2)]. They were given a fat-rich meal containing 1 g fat and 7 mg cholesterol per kg body weight and vitamin A 60,000 IU/m2 body surface. Fat accounted for 60% of calories, and protein and carbohydrates accounted for 15% and 25% of energy respectively. Blood samples were taken at time 0, every 1 h until 6 h, and every 2.5 h until 11 h. Total cholesterol and triacylglycerols in plasma, and cholesterol, triacylglycerols and retinyl palmitate in triacylglycerol-rich lipoproteins (large and small triacylglycerol-rich lipoproteins) were determined. Postprandial responses for triacylglycerols and retinyl palmitate in small triacylglycerol-rich lipoproteins were higher in 1/1 individuals than in 1/2 individuals. No other significant differences were noted. Our data show that the presence of the genotype 1/2 is associated with a lower postprandial lipemic response.

The SstI polymorphism of the apo C-III gene is associated with insulin sensitivity in young men

AIMS/HYPOTHESIS

Insulin resistance is considered to be a risk factor for diabetes and coronary heart disease and is determined by the interaction between genetic and environmental factors. The SstI polymorphism in the apolipoprotein C-III gene has been related to the presence of different features of the insulin resistance syndrome. We investigate if this mutation influences the peripheral effect of insulin in healthy young subjects (30 men and 29 women) eating a westernised diet.

METHODS

We investigated peripheral insulin sensitivity with the insulin suppression test after a 28-day westernised high-saturated fat diet (38% total fat and 18% saturated fat with 115 mg of cholesterol per 1000 Ju).

RESULTS

Steady state plasma glucose values were lower in S1-S1 compared with S1-S2 men (p=0.018 by ANOVA), but not in women (p=0.723).

CONCLUSION/INTERPRETATION

There was no difference between carriers and non-carriers of the S2 allele in relation to incidence and sensitivity; although on subgroup analysis there was an effect in men but not in women.

Cerivastatin improves insulin sensitivity and insulin secretion in early-state obese type 2 diabetes

In a double-blind, placebo-controlled, randomized crossover study, 15 stable mild hyperglycemic patients without treatment and with features of metabolic syndrome were treated with cerivastatin (0.4 mg/day) or placebo for 3 months. The insulin sensitivity index during the euglycemic-hyperinsulinemic clamp (EHC; 5.4 mmol/l; 80 mU x m(-2) x min(-1)) was increased by cerivastatin treatment (66.39 +/- 3.9 nmol x lean body mass [LBM](-1) x min(-1) x pmol(-1) x l(-1)) as compared with placebo (58.37 +/- 3.69 nmol x LBM(-1) x min(-1) x pmol(-1) x l(- 1); P < 0.01) by 13.7%. Glucose oxidation during EHC was significantly higher with statin treatment (16.1 +/- 1.37 micromol x LBM(-1) x min(-1)) as compared with placebo (14.58 +/- 1.48 micromol x LBM(-1) x min(-1); P < 0.05). During hyperinsulinemia (approximately 800 pmol/l) in EHC steady-state, lipid oxidation was significantly decreased and respiratory quotient was significantly increased with statin treatment (0.33 +/- 0.05 mg x LBM(-1) x min(- 1), 0.94 +/- 0.01) as compared with placebo (0.48 +/- 0.06 mg x LBM(-1) x min(-1), 0.91 +/- 0.01; P < 0.01 and P < 0.05, respectively). During statin treatment, the first-phase insulin response increased from 2.07 +/- 0.28 to 2.82 +/- 0.38 pmol x l(-1) x pmol(-1) (P < 0.05). The second phase of insulin responses examined by C-peptide and insulin levels averaged during the hyperglycemic clamp (20 mmol/l) was unchanged. In conclusion, this study demonstrates that 0.4 mg cerivastatin therapy improves first-phase insulin secretion and increases insulin-mediated glucose uptake and respiratory quotient in the early state of obese type 2 diabetes.

Molecular detection of respiratory syncytial virus in postmortem lung tissue samples from Mexican children deceased with pneumonia

BACKGROUND

Respiratory syncytial virus (RSV) is the major viral cause of severe respiratory infections in children younger than 2 years of age. Nevertheless there are not enough epidemiologic data about the role of RSV as a cause of infantile mortality from pneumonia, mainly in young children from developing countries Aim. To determine the frequency of RSV infection in lung tissue samples from Mexican children deceased with pneumonia, by reverse transcription (RT) and PCR.

METHODS

Postmortem lung tissue samples from 98 children younger than 2 years of age who died of pneumonia during the period of 1989 to 1997 were studied. Paraffin was removed with xylene from 10-microm lung sections, the total RNA was extracted and complementary DNA was obtained by RT reaction. A nested PCR with the use of oligonucleotides specific for the F glycoprotein gene was developed. Samples negatives for RSV were tested for the absence of polymerase inhibitors and for complementary DNA integrity.

RESULTS

Twenty-nine of the 98 (30%) children deceased with pneumonia were positive for RSV by RT-PCR; 8 were detected from 13 (62%) children with histopathologic diagnosis of viral pneumonia and 21 from 85 (25%) children with histopathologic diagnosis of bacterial pneumonia (P = 0.018). There was no significant difference in RSV infection according to age groups or seasonal pattern.

CONCLUSIONS

RSV infection is frequent in Mexican children younger than 2 years of age who died of pneumonia. Although RSV was more common in viral pneumonia, mixed infections with RSV and bacterial pneumonia were also common.

Zinc uptake by human erythrocytes with and without serum albumins in the medium

Different mechanisms of Zn uptake are present in mammalian cells. The variations in the Zn uptake by human erythrocytes in the absence and presence of albumins, bovine and human, as well as the differences of Zn uptake with and without 4-4'-diidothiocyanatostilbene-2,2'-disulfonic acid have been analyzed in this study. The results show a significantly greater rate of Zn uptake in the absence rather than in the presence of albumins in the extracellular medium and being significantly greater with bovine than with human serum albumin when the experiments were performed in media with equimolar concentrations of Zn. However, when comparing Zn uptake in a medium without albumin with similar free-Zn concentration to Zn ultrafiltrable (20%) of other one with albumin, a significantly greater Zn uptake on the latter was observed. The DIDS inhibition on Zn uptake is higher if the albumin is also present in the medium. These results suggest that in Zn uptake by erythrocytes the albumin directly or indirectly would be involved, facilitating the well-known processes of passive transport and anionic exchanger.

Plant activation of aromatic amines mediated by cytochromes P450 and flavin-containing monooxygenases

To know the mechanisms involved in the activation of promutagenic aromatic amines mediated by plants, we used Persea americana S117 system (S117) for the activation of 2-aminofluorene (2-AF) and m-phenylenediamine (m-PDA) in Ames assays. In these assays, the effect of the diphenylene iodonium (DPI), an inhibitor of flavin-containing monooxygenases (FMOs), of the 1-aminobenzotriazole (1-ABT), an inhibitor of cytochromes P450 (cyt-P450s) and of the methimazole, a high-affinity substrate for FMOs, was studied. The efficacy of both inhibitors and of the methimazole was verified to find that they did partially inhibit the mutagenesis of both aromatic amines, activated with rat liver S9. Similarly, both inhibitors and methimazole did produce a significant decrease in 2-AF and m-PDA mutagenesis, when the activation system was S117, indicating that, similar to what occurs in mammalian systems, plant FMOs and cyt-P450s can metabolize aromatic amines to mutagenic product(s). However, the affinity of both FMOs and cyt-P450s of plant for 2-AF and m-PDA was different. Data obtained indicate that the activities of plant FMOs must be the main enzymatic system of m-PDA activation while, in 2-AF activation, plant cyt-P450s have the most relevant activities. In addition, peroxidases of the S117 system must contribute to 2-AF activation and some isoforms of FMOs and/or cyt-P450s of the S117 system, uninhibited by the inhibitors used, must be the responsible for a partial activation of m-PDA.

Eradication and follow-up of Helicobacter pylori infection in hemodialysis patients

It is currently accepted that Helicobacter pylori (Hp) infection is crucial in the pathogenesis of peptic ulcer. Therefore, we developed a prospective study to assess the prevalence of Hp infection by the 13C Urea Breath Test (13C UBT) in 52 hemodialysis patients, and we evaluated the efficacy of two consecutive eradication regimens in 23 positive patients with dyspepsia and/or on a transplantation list. The correlation between anti-Hp serology and 13C UBT results was also analyzed in 34 patients who were followed up during 18 months. The Hp prevalence by 13C UBT was 63.5% (33/52). The eradication rate after the first cycle of therapy (amoxicillin 500 mg/8 h and omeprazole 20 mg/12 h, 14 days) was 60.8% (14/23). After the second cycle (clarithromycin 500 mg/12 h plus omeprazole 20 mg/12 h, 14 days), the eradication rate reached 82.6% (19/23). The serological procedure showed a good correlation with 13C UBT (about 80% sensitive and specific) when very restrictive diagnostic and eradication criteria were adopted. We conclude that an eradication rate higher than 80% can be reached after two consecutive cycles of dual therapy in hemodialysis patients. Anti-Hp serological tests must be cautiously interpreted in these patients.

Hemorheological profile in chronic venous insufficiency after surgery

In recent years, there have been rheological abnormalities reported in chronic venous insufficiency (CVI), mainly an increase of erythrocyte aggregability (EA), which probably take part in the pathophysiology of the disease. The aim of this study was to analyze the hemorheological profile after stripping in 45 patients suffering from CVI. Follow-up included laboratory tests on the 7th, 60th and 180th day after surgery. EA was assessed with a photometric aggregometer (MA1, Myrenne) in stasis and low shear (3 s(-1)). The results show an increase of EA on the 7th day after surgery (p<0.001). Two and 6 months later, EA values returned to those found prior to surgery. The plasma fibrinogen level changes in a way parallel to EA. The association between rheological disturbances and thrombogenesis is well known, so the hyperaggregability found supports the antithrombotic prophylaxis in the early postsurgical period. On the other hand, the hemorheological abnormalities persist after stripping, so postsurgical treatment to inhibit EA may be beneficial.

Interferon alfa-2b plus ribavirin for chronic hepatitis C patients who have not responded to interferon monotherapy

BACKGROUND

The role of combination therapy is poorly defined in chronic hepatitis C patients who are non-responders to interferon.

AIM

To assess the efficacy, safety and tolerance of interferon alfa-2b plus ribavirin in chronic hepatitis C patients who do not respond to interferon monotherapy.

METHODS

A total of 127 non-responder patients with chronic hepatitis C received 3 mU t.i.w. of interferon alfa-2b plus 1000-1200 mg ribavirin daily for 48 weeks. Effects of therapy were evaluated by serum aminotransferases and hepatitis C virus (HCV) RNA levels.

RESULTS

Twenty-nine (23%) patients had an end-of-treatment response. Six months after treatment, 20 (16%) patients were sustained responders. Early loss of HCV RNA was the strongest predictor of a sustained response (P < 0.0001). Remission was also more frequent in patients with genotype 1b (P < 0.02), elevated alanine aminotransferase (P < 0.03) and low gamma glutamiltranspeptidase (P < 0.002). Treatment was discontinued in 21 (17%) patients: in 14 for intolerance and in seven due to side-effects.

CONCLUSIONS

Combination therapy with interferon plus ribavirin produced a sustained response in 16% of chronic hepatitis C patients who were non-responders to interferon. This combination was safe and well tolerated.

Evaluating the outcome of severe head injury with transcranial Doppler ultrasonography

The authors conducted a study to determine the value of transcranial Doppler (TCD) ultrasonography in evaluating the outcome of severely head injured patients and to correlate the TCD values with those obtained from intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring. The authors conducted a prospective study of 125 patients with severe head injury (Glascow Coma Scale scores of less than 9) who underwent TCD ultrasonography according to the standard technique of insonating the middle cerebral artery (MCA) and measuring the mean blood flow velocity and pulsatility index within the first 24 hours of admission. The ICP and CPP values, as well as other clinical, analytical, and neuroimaging data, were also recorded. After 6 months, outcome was evaluated using the Glasgow Outcome Scale. Moderate disability and complete recovery were considered "good" outcome; death, vegetative state, and severe disability were considered "poor." In 67 patients (54%) good outcome was demonstrated whereas in 58 (46%) it was poor. The mean blood flow velocity of the MCA in patients with good outcome was 44 cm/second; in those with poor outcomes it was 36 cm/second (p < 0.003). The mean PI in cases of good outcome was 1 whereas in poor outcome was 1.56 (p < 0.0001). The correlations of ICP and CPP to PI were statistically significant (r2 = 0.6; p < 0.0001). When performed in the first 24 hours of severe head injury, TCD ultrasonography is valid in predicting the patient's outcome at 6 months and correlates significantly with ICP and CPP values.

Haemorheological Proælein Chronic Venous Insufæciency

Background:

In recent years, pathophysiological studies and treatment approaches of chronic venous insufficiency (CVI) have focused on haemorheology.

Objective:

To analyse erythrocyte aggregation (EA) and blood viscosity (BV) in mild and severe stages of CVI.

Methods:

In 147 patients (three severity stages), EA was measured with a photometric aggregometer, and BV with a cone-plate viscosimeter. Patients with concomitant pathologies affecting haemorheology were excluded.

Results:

EA was higher in patients (mean EA 10M: 16.4 vs 14.5 control), increasing progressively with the evolution of CVI ( p<0.001). Greatest differences were found for stage III (mean EA 10M: 17.6) vs stage II (15.7) and stage 0 (14.5) respectively ( p<0.001), but rheological abnormalities exist in early grades (I: 16.7) ( p<0.01). Fibrinogen and age had a strong influence on EA ( p<0.003 and p<0.001 respectively). When a covariance analysis avoided their effect, significant global differences between CVI groups persisted. BV at high shear rate was increased at advanced stages (III: mean 3.3 centipoise (cp); I: 3.1 cp) ( p<0.05).

Conclusions:

We found progressive impairment of the haemorheological profile with the worsening stages of CVI, related to age, severity stage and fibrinogen. Rheological impairment is likely to play a part in the pathophysiology of CVI, and perhaps may be useful in its management.

Spontaneous non-typhoidal Salmonella peritonitis in patients with serious underlying disorders

Non-typhoidal Salmonella is a rare cause of spontaneous bacterial peritonitis (SBP). Non-typhoidal Salmonella SBP has been reported in patients with relatively normal ascitic fluid protein levels. Five patients with non-typhoidal Salmonella SBP and a review of the literature are reported. These patients had chronic underlying disorders, such as malignancy, or other conditions causing immunosuppression. In previous reports, an ascitic fluid protein level above 1.5 g/dl was present in six patients, and under 1.5 g/dl in two. In the present report, ascitic fluid protein is above 2.5 g/dl in three patients and under 1.5 g/dl in one. Immunosuppression and the virulence of the organism seem to play a major role in non-typhoidal Salmonella SBP. Physicians should be alert to the possibility of non-typhoidal Salmonella infection in patients with SBP and normal protein levels in ascitic fluid.

Hypercoagulability state in hip and knee surgery: influence of ABO antigenic system and allogenic transfusion

It is well know that people with blood group O have a lower risk for venous thromboembolic disease (VTED) than does the general population. Moreover blood transfusion has been identified as a risk factor for VTED in patients with major trauma. The aim of this work is to investigate the behaviour of several markers of hypercoagulability before and after substitutive surgery of hip and knee in order to evaluate the relationship between the plasmatic levels of these markers, the ABO antigenic system and the allogenic blood transfusion. The plasmatic levels of D dimer (D-D), thrombin-antithrombin complex (TAT), and fragment 1 + 2 of prothrombin (F1 + 2) have been determined by the ELISA method in 79 patients subject to substitutive surgery of hip or knee one day before and one day after surgery. The 41 patients with blood groups different from O had presurgical levels of F1 + 2 higher than those of group O (p = 0.004), while no differences could be found for D-D and TAT. The 28 patients who received allogenic blood presented higher levels of D-D one day after surgery than non-transfused patients (p = 0.043); the practice of transfusion did not modify significantly the levels of TAT and F1 + 2 after surgery. In accordance with these results we suggest that blood group and transfusion are risk factors for hypercoagulability, and therefore we advise for a restrictive policy of transfusion practice. New therapies such as aprotinin should be assayed in order to minimize blood loss.

A phase II study of gemcitabine in platinum pre-treated patients with advanced epithelial ovarian cancer

BACKGROUND

Most patients with advanced ovarian cancer will relapse following platinum-based combination chemotherapy and be considered for second-line treatment. Gemcitabine, a nucleoside analogue, is active against a range of solid tumors. This phase II study investigated the activity of single-agent gemcitabine in patients with recurrent ovarian cancer.

PATIENTS AND METHODS

Thirty-eight patients with FIGO stage III (34%) or IV (64%) ovarian cancer who were previously treated with platinum-containing regimens were enrolled. Patients received 1200 mg/m2 gemcitabine on days 1, 8 and 15 of a 28-day cycle.

RESULTS

Patients completed an average of 3.6 cycles. Two complete and three partial responses were seen in 36 evaluable patients, for an overall response rate of 13.9% (95% CI: 4.7%-29.5%). The median survival time was 6.7 months. Toxicities were generally mild. The most common were grade 3-4 neutropenia and grade 3 leukopenia reported in 23.7% and 10.5% of patients, respectively. One patient had grade 4 pulmonary toxicity.

CONCLUSION

Single-agent gemcitabine is active and well tolerated in patients with recurrent ovarian cancer.

[Hypercoagulability status previous to total hip and knee arthroplasty: the contribution of rheumatoid arthritis]

PURPOSE

Starting from a status hypercoagulability previous to substitutive hip and knee surgery, the aim of this work was to investigate the influence of different osteoarthropatic pictures for which arthroplasty is indicated in the activation of the clotting cascade, rheumatoid arthritis (RA) being one of such pictures.

PATIENTS AND METHODS

Of 79 patients suitable for prosthetic surgery of hip (53) and knee (26), the preoperative values of several markers, namely, D dimers (D-D), thrombin-antithrombin (TAT) complex, and F1 + 2 prothrombin fragment (F1 + F2) were assessed by enzymoimmunoasay. The mean age of the patients was 65.5 years, and their sex distribution was 50 women and 29 men. The indications for arthroplasty were as follows: osteoarthrosis (62), aseptic necrosis (11), RA (9), articular gout (2), previous fracture (2), more than one diagnosis overlapped in some cases. The results attained were compared with a control group comprised of 33 subjects (16 women and 17 men) with mean age similar to the patient's group (68.06 years).

RESULTS

The D-D values in the patients suitable for hip arthroplasty and the TAT values in patients suitable for both types of surgery were significantly higher than those found in the control group (p = 0.012 and 0.01, respectively). The preoperative TAT levels of the RA patients were significantly higher (p = 0.025) than those found in the patients with the other surgical indications.

CONCLUSIONS

Previously to the performance of arthroplasty, the patients show hypercoagulative marker values higher than those of age-matched controls. The significant rising of TAT found in RA patients is concordant with the literature, and this fact makes it advisable to include RA among the pathologic situations associated with hypercoagulability, as this is a common indication for substitutive hip and knee surgery with high risk of venous thromboembolic disease.

Activation of arylamines to mutagenic product(s) by two in vitro plant systems

Plant activation of three isomers of phenylenediamine o- m- and p-phenylenediamine, has been studied. Two in vitro plant systems have been used: Persea americana S117 with mixed-function oxidase (MFO) and peroxidase activities, and Zea mays S9 which contains only peroxidase activity. As genetic endpoint, the classical Salmonella tester strains. TA98 and TA100, their derivatives with high O-acetyltransferase levels (YG1024 and YG1029, respectively) and TA98/1.8-DNP6, deficient in this enzyme, have been assayed. Of the three isomers studied, only m-PDA was activated to mutagenic product(s) by both plant systems. This activation required the bacterial O-acetyltransferase activity to give frameshift mutagenic product(s), detected in TA98 and YG1024 strains. In all the assays the P americana system was more potent than the Z. mays system in activating m-PDA. A slight increase of the number of YG1029 revertants was detected when m-PDA was activated by P. americana, suggesting that this compound can be also converted into ultimate mutagenic product(s) that induce base-pair substitutions. m-PDA activation by Z. mays was dependent on the peroxidase activity of this system, but the activation produced by P. americana was totally dependent on MFOs, because a total inhibition of the mutagenic response was found when these activities were inhibited. In addition, the P. americana system was more potent in generating proximal mutagenic forms from m-PDA than S9 from non-induced rat liver, although S9 from Aroclor 1254-induced Sprague-Dawley male rats was the most potent system in the m-PDA activation. These results indicate that the P. americana system can be useful in determining the role of mixed-function oxidases in plant activation of xenobiotics.

[Comparative study of 2 antithrombotic regimens in 75 patients with coronary endoprostheses]

PURPOSE

To compare systemic anticoagulation with antiaggregation in patients with coronary stent, with regard to subacute occlusion, mean hospital staying and haemorrhagic complications.

PATIENTS AND METHODS

Seventy-five patients with coronary stent were treated with one of two different antithrombotic protocols. A group comprised of 34 patients (group A) received sodium heparin and acenocoumarin, plus acetylsalicylic acid (325 mg) and dipyridamole (225 mg). The remaining 41 patients (group B) were given antiplatelet agents, namely ticlopidine (125-250 mg) and aspirin (125 mg).

RESULTS

One case of group A (2.9%) showed thrombosis due to stent occlusion. No thrombotic complications were seen in the patients with antiplatelet drugs. Haemorrhagic complications were present in 11 group A patients (32.3%), and blood transfusion was necessary in 3 of them. Hemorrhage was present in 9 cases of group B (21.8%), and none of them needed blood transfusion. The mean number of days to achieve INR > 2 was 3.06 (1-11) in group and 2.02 (1-5) in group B.

CONCLUSIONS

Antiplatelet regimes appear as a good choice in coronary stent, in spite of the fact that the primary indication seems that of group A.

UFT in combination as adjuvant therapy for breast cancer. Grupo Oncologico de Sevilla Seville, Spain

Between 1989 and 1993, 409 evaluable patients with breast cancer have been treated with tegafur and uracil (UFT) in an adjuvant setting in two different trials. Data from both trials were reviewed in December 1995 after a mean follow-up of 5.09 +/- 1.1 years (range, 2.9 to 7.1 years). The aim of the first trial was to demonstrate the activity of UFT 400 mg/day for 6 months plus prednimustine 60 mg/m2 for 7 consecutive days, every 28 days in 6 cycles given orally (arm B). This scheme was compared with 6 cycles of cyclophosphamide 600 mg/m2, plus methotrexate 40 mg/m2, plus fluorouracil 600 mg/m2, every 4 weeks (arm A). In this study, 187 premenopausal women were evaluable, 96 in arm A and 91 in arm B, all of whom had positive axillary nodes. Although there were more younger patients in arm A than in arm B, prognostic factors were similar in both groups. Disease-free survival and overall survival were similar in both arms. However, some concern is raised by the low disease-free survival rate. The toxicity was mild (mainly nausea and vomiting and alopecia) and slightly worse in arm A. We believe that oral administration could be a useful alternative to the parenteral route. In the second trial, 222 evaluable patients received 20 mg/day of tamoxifen (Nolvadex) for 1 year (arm A), or the same dose of tamoxifen plus UFT 400 mg/day for 6 months. All patients were postmenopausal, and the characteristics of the tumors were the same as those in patients in the first trial. In arm A there were 109 patients and in arm B, 113. The groups were well balanced. The overall survival and the disease-free survival rates were equal in both arms, but were longer in arm B in the subset of patients with five or more axillary-involved nodes. The toxicity was negligible in both arms. We conclude that UFT/tamoxifen might be useful in postmenopausal patients with five or more involved nodes who are unable to follow a more aggressive schedule because of their age or low performance status.

Prevalence and seasonal activity of Ixodes ricinus (Acari:Ixodidae) on domestic ruminants of the Basque country, Spain

Ixodes ricinus on domestic ruminants was sampled through a natural year at several points in the Basque country, north Spain. The sampling points were comprised of the different natural regions, according to climate and vegetation, into which the region is commonly divided. Both the immature and adult stages were collected on cattle and sheep at five of the eight collecting points, namely in areas with a medium elevation, mild summers and a medium to high annual rainfall. The adults of this tick showed a bimodal pattern of activity in some areas, while in others the pattern was unimodal. It was concluded that, because of the adequate climate, I. ricinus is widely distributed in the Basque country, with geographically close populations adapted to different, local, changing conditions.

Significant increase in eradication rates of Helicobacter pylori infection with two consecutive dual therapies (omeprazole and amoxycillin or omeprazole and clarithromycin). A randomized study in 450 Spanish patients

Helicobacter pylori infection is associated with peptic ulcer disease and chronic gastritis, and eradication of the microorganism markedly reduces the recurrence of peptic ulcer. However, a major problem is the choice of a treatment that is effective, has high eradication rate, and is well tolerated by patients. We evaluated the eradication of H. pylori infection in patients with chronic gastritis (CG), duodenal ulcer (DU), and gastric ulcer (GU) after two dual therapies (omeprazole with either amoxycillin or clarithromycin). Of 450 patients initially included in the study, 207 had CG, 187 DU and 56 GU, and all presented with H. pylori infection. Diagnosis was made from endoscope examination, biopsy samples, rapid urease test and 13C-urea breath test (UBT). H. pylori infection was considered to be present when two of the tests had positive results. All patients were randomized to one of two regimens: (A) omeprazole (20 mg b.i.d.) plus amoxycillin (750 mg t.i.d.) or (B) omeprazole (40 mg b.i.d.) plus clarithromycin (500 mg t.i.d.). The duration of each of the regimens was 2 weeks. Fifty-eight patients who showed H. pylori infection after the first treatment (27 with CG, 24 with DU, and 7 with GU) were allocated to a second therapy. H. pylori eradication was assessed by UBT, 6 weeks after the end of the therapies; positive values were those higher than 5 delta units. A second consecutive dual therapy of omeprazole plus an antibiotic (amoxycillin or clarithromycin) not used in the first therapy improved on the eradication rates obtained with the first regimen. The overall eradication rates were also higher, but no significant differences were found between amoxycillin and clarithromycin. The best results were obtained in those patients with GU.

Comparative study of propofol versus midazolam in the sedation of critically ill patients: results of a prospective, randomized, multicenter trial

OBJECTIVES

To compare the effectiveness, characteristics, duration of action, hemodynamic and biochemical effects, and side effects of propofol and midazolam used for continuous intravenous sedation of ventilated critically ill patients.

DESIGN

Multicenter, prospective, randomized, nonblinded study.

SETTING

Nine Spanish general intensive care units (ICUs).

PATIENTS

Ninety-eight patients admitted to the ICU who were mechanically ventilated and required sedation for a minimum of 48 hrs.

INTERVENTIONS

Propofol or midazolam was used for induction and maintenance of continuous intravenous sedation for a maximum of 5 days. The effectiveness of those two regimens was assessed according to their effects on ventilatory management and the presence of agitation.

MEASUREMENTS AND MAIN RESULTS

In 93% of the patients studied, there was a medical cause necessitating mechanical ventilation. The mean (+/-SD) duration of sedation was 81 +/- 25 hrs and 88 +/- 27 hrs for the propofol and midazolam groups, respectively. The induction dose was 2.24 +/- 0.43 mg/kg over 318 +/- 363 secs for propofol, and 0.22 +/-0.07 mg/kg over 33 +/-29 secs for midazolam. The maintenance dose was 2.8 +/-1.1 mg/kg/hr for propofol and 0.14 +/- 0.10 mg/kg/hr for midazolam. There was no difference regarding the opiate and muscle relaxant requirements between the two groups. Sedation with propofol was more effective in achieving patient-ventilator synchrony than that with midazolam after the first hour of treatment (p < .01). Patients sedated with propofol awoke more rapidly and with less variability that those patients sedated with midazolam (23 +/- 16 mins vs. 137 +/- 185 mins, respectively, p < .05), particularly in those patients requiring deep sedation (27 +/- 16 mins vs. 237 +/- 222 mins, respectively, p < .01). No hemodynamic or biochemical changes were detected in any of the treatment groups. During induction, five patients in the propofol group and two patients in the midazolam group had hypotension.

CONCLUSIONS

In this population of critically ill patients, propofol is an effective and safe alternative for sedation, with some advantages, such as short duration of action and high effectiveness over the conventional regimen with benzodiazepines and opiates.

Inhibition of D-amino acid oxidase by alpha-keto acids analogs of amino acids

The inhibition of D-amino acid oxidase by certain alpha-keto acids products of the reaction with D-amino acids, in particular alpha-keto acids that are analogs of the amino acids alanine, valine, leucine, phenylanaline, phenylglycine, tyrosine and tryptophan, is reported. All the alpha-keto acids assayed behaved as substrate competitive inhibitors of the enzyme. The relationship between the degree of inhibition and the structure of the inhibitor is discussed.

Parkinsonism in an HIV-infected patient with hypodense cerebral lesion

A 49-year-old man presented with fever and parkinsonism. Examination of cerebrospinal fluid confirmed tuberculous meningitis. Cerebral computerized tomography scan revealed hypodense lesions and human immunodeficiency virus tests were positive. The patient's clinical picture and parkinsonism were improved with tuberculosis treatment.