Efficacy of delafloxacin alone and in combination with cefotaxime against cefotaxime non-susceptible invasive isolates of Streptococcus pneumoniae

OBJECTIVE

We assessed the in vitro activity of delafloxacin and the synergy between cefotaxime and delafloxacin among cefotaxime non-susceptible invasive isolates of Streptococcus pneumoniae (CNSSP).

METHODS

A total of 30 CNSSP (cefotaxime MIC > 0.5 mg/L) were studied. Serotyping was performed by the Pneumotest-Latex and Quellung reaction. Minimum inhibitory concentrations (MICs) of delafloxacin, levofloxacin, penicillin, cefotaxime, erythromycin and vancomycin were determined by gradient diffusion strips (GDS). Synergistic activity of delafloxacin plus cefotaxime against clinical S. pneumoniae isolates was evaluated by the GDS cross method.

RESULTS

Delafloxacin showed a higher pneumococcal activity than its comparator levofloxacin (MIC50, 0.004 versus 0.75 mg/L and MIC90, 0.047 versus >32 mg/L). Resistance to delafloxacin was identified in 7/30 (23.3%) isolates, belonging to serotypes 14 and 9V. Synergy between delafloxacin and cefotaxime was detected in 2 strains (serotypes 19A and 9V). Antagonism was not observed. Addition of delafloxacin increased the activity of cefotaxime in all isolates. Delafloxacin susceptibility was restored in 5/7 (71.4%) strains.

CONCLUSIONS

CNSSP showed a susceptibility to delafloxacin of 76.7%. Synergistic interactions between delafloxacin and cefotaxime were observed in vitro among CNSSP by GDS cross method.

Increase of Diversity of Mumps Virus Genotype G SH Variants Circulating Among a Highly Immunized Population: Spain, 2007-2019

MuV caused three epidemic waves in Spain since genotype G emerged in 2005, despite high vaccination coverage. SH gene sequencing according to WHO protocols allowed the identification of seven relevant variants and 88 haplotypes. While the originally imported MuVi/Sheffield.GBR/1.05/-variant prevailed during the first two waves, it was subsequently replaced by other variants originated by either local evolution or importation, according to the additional analysis of hypervariable NCRs. The time of emergence of the MRCA of each MuV variant clade was concordant with the data of the earliest sequence. The analysis of Shannon entropy showed an accumulation of variability on six particular positions as the cause of the increase on the number of circulating SH variants. Consequently, SH gene sequencing needs to be complemented with other more variable markers for mumps surveillance immediately after the emergence of a new genotype, but the subsequent emergence of new SH variants turns it unnecessary.

The demography and characteristics of SARS-CoV-2 seropositive residents and staff of nursing homes for older adults in the Community of Madrid: the SeroSOS study

Background: Nursing homes for older adults have concentrated large numbers of severe cases and deaths for COVID-19.

Methods: Point seroprevalence study of nursing homes to describe the demography and characteristic of SARS-CoV-2 IgG-positive residents and staff.

Results: Clinical information and blood samples were available for 9,332 residents (mean age 86.7 ± 8.1 years, 76.4% women) and 10,614 staff (mean age 45.6 ± 11.5, 86.2% women). Up to 84.4% of residents had frailty, 84.9% co-morbidity and 69.3% cognitive impairment; 65.2% of workers were health-aides.

COVID-19 seroprevalence was 55.4% (95% CI, 54.4–56.4) for older adults and 31.5% (30.6–32.4) for staff. In multivariable analysis frailty of residents was related with seropositivity (OR: 1.19, p = 0.02). In the case of staff, age > 50 years (2.10, p < 0.001), obesity (1.19, p = 0.01), being a health-aide (1.94, p < 0.001), working in a center with high seroprevalence in residents (3.49, p < 0.001), and contact with external cases of COVID-19 (1.52, p < 0.001) were factors associated with seropositivity. Past symptoms of COVID-19 were good predictors of seropositivity for residents (5.41, p < 0.001) and staff (2.52, p < 0.001).

Conclusions: Level of dependency influences risk of COVID-19 among residents. Individual and work factors, and contacts outside the nursing home are associated with COVID-19 exposure in staff members. It is key to strengthen control measures to prevent the introduction of COVID-19 into care facilities from the community.

Effectiveness of different vaccine schedules for heptavalent and 13-valent conjugate vaccines against pneumococcal disease in the Community of Madrid

INTRODUCTION

The heptavalent pneumococcal conjugate vaccine (PCV-7) was added to the childhood routine vaccination program in the Community of Madrid in November of 2006 with 3+1 recommended doses and a catch-up for those under 2years old. In June 2010, PCV-7 was replaced by 13-valent vaccine (PCV-13) with 2+1 recommended doses. In July of 2012, the PCV-13 was removed from the funded program and reintroduced again (2+1 recommended doses) in December 2014. In between, children were vaccinated privately with 3+1 recommended doses of PCV-13. The aim of this study was to evaluate the effectiveness of each vaccination schedule used in the Community of Madrid.

METHODS

We included all cases of invasive pneumococcal disease (IPD) reported between 2007 and 2015 to the Notifiable Diseases Surveillance System. Vaccination information was obtained from the Immunization Registry. Vaccine effectiveness (VE) was estimated using the indirect cohort design for cases with serotype information.

RESULTS

A total 779 cases were included in the study. Among them 47.6% of the cases were primo-vaccinated with booster, 20% primo-vaccinated, 15.9% incompletely primo-vaccinated and 16.5% not vaccinated. The VE for ≥1 doses of any PCV was 82% (CI 95%: 67.8-89.9%): 91.9% (CI 95%: 76.5-97.2%) for PCV-7 and 77.2% (48.6-89.9%) for PCV-13. VE in those receiving the full 2+1 or 3+1 schedules was 100% for both vaccines.

CONCLUSIONS

A high number of vaccine failures were reported in children before they had the opportunity to receive the booster dose, especially due to PCV-13-non-PCV-7 serotypes. VE was higher for PCV-7 compared to PCV-13, except for those that received the complete schedule with booster that achieved 100% of VE, which shows the relevance of the vaccines and complying with all doses scheduled.

Incidence trends in pertussis in the Autonomous Region of Madrid, Spain: 1982-2005

The objective of this study was to describe the incidence (1982-2005) and epidemiologic characteristics of pertussis cases (1998-2005) in the Autonomous Region of Madrid using data drawn from the epidemiologic surveillance network and computerised hospital discharge data. In the 1990s, the trend in the pertussis incidence in the Autonomous Region of Madrid was clearly falling. The typical seasonal pattern of pertussis remained. A peak in incidence were observed in 2000, and another peak, 2.5 times higher, in 2003. They affected all age groups, but children under one year of age were the most frequent cases, followed by the five to nine year-olds. The greatest increase was seen in the age groups from 10 to 14 and from five to nine. Since 2002, the proportion of cases diagnosed serologically has increased. The incidence of hospital discharges among small children exceeded that of reported cases. More than half of the cases with known vaccination status had received at least three doses of vaccine. The upward trend observed since 2002 could be due to improved case detection, availability of serologic techniques, and a rise in the susceptible population aged five to 14 years. The fact that epidemic peaks continue to occur and that there is a seasonality to the disease seems to indicate that despite the vaccination programme the circulation of the bacteria has not been interrupted. The introduction of the acellular vaccine in 2000 does not appear to have played a significant role in the increase in disease incidence.

Late detection of a shigellosis outbreak in a school in Madrid

Even though shigellosis in Spain is rare, an indigenous outbreak is occasionally detected. We describe an outbreak in a school in Madrid caused by person-to-person transmission of Shigella sonnei. After the detection of Shigella sonnei in a stool sample from a 3 year old girl, an investigation at her school was initiated. Questionnaires were distributed to the parents of 520 pupils attending the school. A case was defined as a school case if it was the first case in a child's household, and as a household case if other members of the household had fallen ill first. We identified 88 cases (60 pupils and 28 of their family members). The attack rate (AR) was 12% in the school and 32% in the families. There was a significant association between higher AR and lower age. The outbreak lasted for two months. The length and the shape of the epidemic curve of the 60 cases in pupils suggests person-to-person transmission. Shigella sonnei isolated from 5 different cases were typed by pulsed field gel electrophoresis (PFGE) and was found to be an identical strain. The prolonged duration of the outbreak was probably due to delayed detection, and stopped as soon as control measures were introduced.

Late detection of a shigellosis outbreak in a school in Madrid

Even though shigellosis in Spain is rare, an indigenous outbreak is occasionally detected. We describe an outbreak in a school in Madrid caused by person-to-person transmission of Shigella sonnei. After the detection of Shigella sonnei in a stool sample from a 3 year old girl, an investigation at her school was initiated. Questionnaires were distributed to the parents of 520 pupils attending the school. A case was defined as a school case if it was the first case in a child’s household, and as a household case if other members of the household had fallen ill first. We identified 88 cases (60 pupils and 28 of their family members). The attack rate (AR) was 12% in the school and 32% in the families. There was a significant association between higher AR and lower age. The outbreak lasted for two months. The length and the shape of the epidemic curve of the 60 cases in pupils suggests person-to-person transmission. Shigella sonnei isolated from 5 different cases were typed by pulsed field gel electrophoresis (PFGE) and was found to be an identical strain. The prolonged duration of the outbreak was probably due to delayed detection, and stopped as soon as control measures were introduced.

New features of rubella in Spain: the evidence of an outbreak

In most of western Europe the rubella vaccine coverage is high. However, prior to the introduction of the vaccine in Latin America, rubella susceptibility in women of childbearing age was 10-25%. Forty one (93%) countries in Latin America have adopted the rubella vaccine since 2002. The adult immigrant population in Spain constitutes a group of susceptibles. In February 2003, the Madrid Community Measles Elimination Plan detected an increase in rubella notifications in women who had been born in Latin America. A descriptive study was undertaken to characterise the outbreak. A confirmed case was a person with fever or rash and a positive IgM serology, and living in Madrid, between 1 December 2002 and 31 March 2003. The secondary attack rate (SAR) per household was calculated. A total of 19 cases of rubella were identified, 15 were confirmed and 4 were probable cases. Fourteen (73.7%) cases were women at childbearing age. The mean age was 25.1 years. One pregnancy was diagnosed with a voluntary termination. Eleven (57.9%) cases were from Ecuador. The mean time of residence in Spain was 41 months. None of the cases or the 54 (78.3%) household contacts had been vaccinated against rubella. The SAR was 9.1%. This study showed the spread of rubella in the susceptible Latin American Community that is resident in Madrid. The interventions proposed were a vaccination programme towards immigrants, a health education campaign to prevent congenital rubella, and a health professional training programme case management.

New features of rubella in Spain: the evidence of an outbreak

In most of western Europe the rubella vaccine coverage is high. However, prior to the introduction of the vaccine in Latin America, rubella susceptibility in women of childbearing age was 10-25%. Forty one (93%) countries in Latin America have adopted the rubella vaccine since 2002. The adult immigrant population in Spain constitutes a group of susceptibles. In February 2003, the Madrid Community Measles Elimination Plan detected an increase in rubella notifications in women who had been born in Latin America. A descriptive study was undertaken to characterise the outbreak. A confirmed case was a person with fever or rash and a positive IgM serology, and living in Madrid, between 1 December 2002 and 31 March 2003. The secondary attack rate (SAR) per household was calculated. A total of 19 cases of rubella were identified, 15 were confirmed and 4 were probable cases. Fourteen (73.7%) cases were women at childbearing age. The mean age was 25.1 years. One pregnancy was diagnosed with a voluntary termination. Eleven (57.9%) cases were from Ecuador. The mean time of residence in Spain was 41 months. None of the cases or the 54 (78.3%) household contacts had been vaccinated against rubella. The SAR was 9.1%. This study showed the spread of rubella in the susceptible Latin American Community that is resident in Madrid. The interventions proposed were a vaccination programme towards immigrants, a health education campaign to prevent congenital rubella, and a health professional training programme case management.

Is there a change in cytomegalovirus seroepidemiology in Spain?

The aim of this paper is to compare the seroprevalence of cytomegalovirus (CMV) in women in the Autonomous Region of Madrid (ARM) obtained in two different years (1993 and 1999), according to age and seroprevalence of a virus transmitted by the faecal-oral route (hepatitis A virus, HAV) and another virus of respiratory transmission (varicella zoster virus, VZV). A total of 1813 serum samples were studied, taken from females aged 2-40 in two different serosurveys which were representative of the general population in the ARM. Of these, 933 were taken in 1993, and 880 in 1999. In each survey the samples were distributed over six groups, according to age group (2-5, 6-10, 11-15, 16-20, 21-30 and 31-40 years). CMV- and VZV-specific IgG was tested by indirect ELISA (Dade-Behring, Germany); and HAV-IgG by ImX (Abbott, USA) in the 1993 samples, or by Vidas (BioMérieux, France) in the case of those taken in 1999. A significant age-related rise in CMV seroprevalence was observed in both serosurveys. The seroprevalence obtained was lower in all age groups in 1999 than in 1993. The differences were statistically significant in two age groups: 6-10 years old (43.7 vs. 56.7%) and 31-40 years old (79.1 vs. 90.3%). In the younger age groups concurrent seroprevalence of CMV and VZV was significant lower in 1999. In older age groups a significant decrease in concurrent seroprevalence of both CMV and HAV was also seen. Agreement between serological results for CMV-HAV, CMV-VZV and HAV-VVZ during the two time periods and in every age group was poor or fair (kappa index < or = 0.2 or between 0.21 and 0.4) in all age groups. To conclude, a change in CMV epidemiology seems to be taking place in Madrid. The increase in the proportion of CMV seronegative women of childbearing age may have some impact on the incidence of congenital diseases related to vertical transmission of CMV. Apparently, such a change, among children, could be related to a lower close contact transmission rate (as in VZV), and among adults to improvements in standards of public health (as in HAV). However, due to the poor or fair agreement between serological results for CMV-HAV, CMV-VZV and HAV-VVZ, other independent factors may affect the fall in CMV seroprevalence.

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.

Prevalence of CagA and VacA antibodies in children with Helicobacter pylori-associated peptic ulcer compared to prevalence in pediatric patients with active or nonactive chronic gastritis

VacA and CagA serological responses were detected in pediatric patients: 44 and 56%, respectively, in peptic ulcer (PU) patients, 33.3 and 44.4% in active chronic gastritis (ACG) patients, and 23.2 and 39.2% in non-ACG patients. Higher seroprevalence to CagA+VacA and to CagA+VacA+35-kDa antigen was found among PU patients. However, a low level of sensitivity and specificity was found for indirect detection of PU patients.

[Tension pneumoperitoneum as complication in a case of perioperative barotrauma]

Tension pneumoperitoneum is rare complication that causes severe changes in respiratory and cardiocirculatory function. We report the case of an 84 year old woman who developed tension pneumoperitoneum soon after cholecystectomy by subcostal laparotomy. Tension pneumoperitoneum presented with barotrauma, bilateral pneumothorax, extensive subcutaneous and pneumomediastinum and was accompanied by severe worsening of hemodynamic variables and gas exchange. After confirming the diagnosis by emergency CT scan, the first therapeutic action was decompression of the peritoneal. This fast, simple maneuver was followed by rapid hemodynamic and respiratory improvement. Tension pneumoperitoneum similar to the case we report has been described as a complication of mechanical ventilation and barotrauma; however, the possibility that the clinical picture might be caused by perforation of a hollow viscera has given rise to a variety of suggested therapeutic alternatives, including exploratory laparotomy, which has sometimes later proven to have been unnecessary. In the light of the case we report and the literature, we suggest a therapeutic sequence starting with emergency abdominal decompression and to fulfill two objectives: a) to remove the threat to life, and b) to limit the practice of emergency exploratory laparotomy to cases in which that technique is truly indicated.

[The Helicobacter pylori adhesion gene: relation with the origin of the isolates and associated disease]

BACKGROUND

The adhesion gene (hpaA) of Helicobacter pylori isolates from different Spanish regions was studied by PCR-RFLP in order to group the strains according to the origin of the strains and to relate it with ulcer or gastritis production.

METHODS

One hundred and forty three Helicobacter pylori clinical isolates were obtained from the culture of gastric biopsies (29 from Ibiza, 39 from Madrid, 36 from Almería and 39 from Avilés). After DNA extraction, a PCR was performed to amplify a 375 pb fragment of the hpaA gene which was digested with Hinfi and SauIIIa.

RESULTS

The gene was detected in all of the strains studied. After digestion with Hinfi and SauIIIa, three and four patterns called 1, 2 and 3 and A, B, C and D were obtained, respectively. Strains from Madrid and Almería showed the highest hpaA genetic variability. In the relationship with the pathology, patterns 1 and A were the most prevalent in strains obtained from patients with ulcer and with gastritis.

CONCLUSIONS

The results of hpaA gene study show the genetic variability of Helicobacter pylori and slight differences according to the origin were found.

High-level mupirocin resistance among Spanish methicillin-resistant Staphylococcus aureus

Twelve strains of methicillin-resistant Staphylococcus aureus with high-level resistance to mupirocin were studied. The MIC of methicillin was 16 to 128 mg/l and the MIC of mupirocin > or = 512 mg/l. All of the isolates carried a plasmid of about 30 MDa, and one strain lost resistance to mupirocin when the plasmid was cured. Three different resistance patterns were found: six strains were resistant to ciprofloxacin, kanamycin, and 10 mg/l of cadmium sulfate; two strains were resistant to these agents as well as to gentamicin, erythromycin, clindamycin, mercury chloride, and ethidium bromide; and four strains were resistant to the previously named agents as well as to rifampicin and tetracycline. The use of this valuable topical antibiotic, especially in long-term-care facilities, should be monitored to avoid dissemination of resistance.

[Use of the polymerase chain reaction (PCR) for the diagnosis of Helicobacter pylori infection in pediatric patients]

BACKGROUND

Several direct or non direct methods may be used to detect H. pylori infection. A molecular method, PCR with ureA primers, was used in this study in 43 gastric biopsies obtained from paediatric patients with digestive symptomatology and the results were compared with those obtained by histology and culture.

METHODS

Culture and histological stain were performed from gastric biopsies taken at routine endoscopy following standard methodology. A PCR with specific primers for the ureA gene was applied and the 411 pb fragment detected by agarose gel electrophoresis.

RESULTS

From the 43 gastric biopsies, 21 were positive by culture (48.8%), 25 by histology (58.1%) and 29 by PCR (67.4%). In 30 biopsies (69.7%) PCR results were in good agreement with the reference method (histology and/or culture). In 7 biopsies the PCR was positive (16.3%), although the reference method was negative and in 6 (13.9%) the PCR was negative being positive the histology (5 samples) or histology and culture (1 sample).

CONCLUSIONS

PCR shows the highest positive percentage among the methods used. The use of as many methods as possible in the H. pylori infection, increases the diagnosis of the infection.

[Bacterial meningitis in emergency medicine. Factors associated with delay of antimicrobial therapy]

BACKGROUND

Bacterial meningitis is a severe infection. Outcome might be improved if diagnosis and therapy are achieved promptly. We studied the time elapsed until antimicrobial therapy and analyzed factors associated to delay.

METHODS

We performed a retrospective study of bacterial meningitis diagnosed in a hospital emergency medicine department in two consecutive years. Dependent variable was time since admission to antimicrobial therapy; delay was defined as time to administration longer than 2 h. The relationship between clinical variables and delay was studied with bivariate analysis. Significative variables were included in a multivariate analysis using multiple logistic regression.

RESULTS

We studied 40 cases of bacterial meningitis (67.5% female, mean age 25.2 years). The mean time to antibiotic therapy was 127 min; in 16 patients (40%; 95% confidence interval: 25-56%) delay was 2 h or more. In bivariate analysis differences were observed for age (15.5 +/- 24.2 vs 39.7 +/- 28.7 years; p < 0.01), temperature (38.7 +/- 1 vs 38 +/- 1.1 degrees C; p < 0.05), mean blood pressure (77 +/- 14 vs 91 +/- 20 mmHg; p < 0.05), headache (29% vs 75%; p < 0.01), meningeal signs (63% vs 19%; p < 0.01), skin lesions (60% vs 13%; p < 0.01), "sick" presentation (67% vs 19%; p < 0.01), performance of CT scan (8% vs 38%; p < 0.05) and appropriateness of management (96% vs 44%; p < 0.001). In multivariate analysis only absence of skin lesions and inappropriate management remained significative. Mortality was higher when there was a delay of more than 2 h in antimicrobial therapy (25% vs 0%; p < 0.05).

CONCLUSIONS

Factors associated with delay of antimicrobial therapy were the absence of skin lesions and inappropriate management.

[Evaluation of a western blot technique (Helicoblot 2.0) fpr the detection of specific Heliocobacter pylori antigens in children)]

BACKGROUND

The aim of this study was to evaluate the diagnosis usefulness of antibodies detection against different specific antigens of H. pylori (Hp) in children by a Western-blot commercially available (Helicoblot 2.0).

MATERIAL AND METHODS

96 symptomatic paediatric patients in two groups were studied. Group 1: 48 patients Hp positive by culture and/or histology (mean age, 10.19 +/- 3.40 years; 27 boys and 21 girls) and group 2: 48 patients Hp negative by both culture and histology (mean age, 9.31 +/- 3.15 years; 34 boys and 14 girls). Qualitative IgG detection against the protein antigens of 19.5 kD (urease E), 26.5 kD (urease D), 30 kD (urease H), 35 kD, 89 kD (vacuolating toxin VacA) and 116 kD (cagA protein) was determined by a Western-blot assay (Helicoblot 2.0, Genelabs, Singapore).

RESULTS

A specificity of 100% was obtained when reactivity against 19.5 kD protein (urease E) was considered alone. However, the best accuracy levels were observed with 26.5 kD (urease A) and 30 kD (urease H) antigens. An accuracy of 88.5% was observed when the manufacturer's recommended criteria was used (positivity of at least 116, 89 or 35 kD single bands or positivity of at least 2 bands of the 30, 26.5 or 19.5 kD).

CONCLUSIONS

Helicoblot 2.0 is a good method to diagnosis Hp infection in children. A criteria combining IgG against 2 urease antigens (preferentially urease A) or one urease antigen and a virulence associated protein (CagA o VacA) is recommended.

In vitro activity of ebrotidine, ranitidine, omeprazole, lansoprazole, and bismuth citrate against clinical isolates of Helicobacter pylori

The aim of this study was to determine the in vitro activity of ranitidine, ebrotidine, bismuth citrate, omeprazole, and lansoprazole against 113 clinical isolates of Helicobacter pylori cultured from gastric biopsies. An agar dilution method using Mueller-Hinton agar plus 7%, horse blood, an inoculum of 10(6) cfu/spot, and incubation in a CO2 incubator for 2 to 5 days was used. The minimum inhibitory concentrations for 50 and 90% of the isolates tested, respectively, were as follows: ranitidine, 1024 and 1024 mg/l; ebrotidine, 64 and 256 mg/l; bismuth citrate, 1 and 4 mg/l; omeprazole, 16 and 16 mg/l; and lansoprazole, 1 and 1 mg/l. Ebrotidine was more active than ranitidine, and lansoprazole was the most active compound against the Helicobacter pylori isolates tested.

Measurement of mechanical warpage in CR-39 lenses

The warpage of CR-39 ophthalmic spherical lenses of a variety of powers and compressed in the radial direction is measured as a function of the applied tangential force. The lenses are cut with circular shape and then mounted on a frame specially designed to measure the tangential force by means of a calibrated coil spring. The measurements are performed with a high resolution micrometer at different points on the lens surfaces. The warpage of the two surfaces of each lens is calculated and then a quantitative value of surface power variation is given. From these data, vertex power and oblique astigmatism variation are shown. Departure of the surfaces from sphere as a function of the applied tangential force is analysed.

Optical flow computation using extended constraints

Several approaches for optical flow estimation use partial differential equations to model changes in image brightness throughout time. A commonly used equation is the so-called optical flow constraint (OFC), which assumes that the image brightness is stationary with respect to time. More recently, a different constraint referred to as the extended optical flow constraint (EOFC) has been introduced, which also contains the divergence of the flow field of image brightness. There is no agreement in the literature about which of these constraints provides the best estimation of the velocity field. Two new solutions for optical flow computation are proposed, which are based on an approximation of the constraint equations. The two techniques have been used with both EOFC and OFC constraint equations. Results achieved by using these solutions have been compared with several well-known computational methods for optical flow estimation in different motion conditions. Estimation errors have also been measured and compared for different types of motion.

Periodic quasi-orthogonal spline bases and applications to least-squares curve fitting of digital images

Presents a new covariant basis, dubbed the quasi-orthogonal Q-spline basis, for the space of n-degree periodic uniform splines with k knots. This basis is obtained analogously to the B-spline basis by scaling and periodically translating a single spline function of bounded support. The construction hinges on an important theorem involving the asymptotic behavior (in the dimension) of the inverse of banded Toeplitz matrices. The authors show that the Gram matrix for this basis is nearly diagonal, hence, the name "quasi-orthogonal". The new basis is applied to the problem of approximating closed digital curves in 2D images by least-squares fitting. Since the new spline basis is almost orthogonal, the least-squares solution can be approximated by decimating a convolution between a resolution-dependent kernel and the given data. The approximating curve is expressed as a linear combination of the new spline functions and new "control points". Another convolution maps these control points to the classical B-spline control points. A generalization of the result has relevance to the solution of regularized fitting problems.

Analysis of optical flow constraints

Different constraint equations have been proposed in the literature for the derivation of optical flow. Despite of the large number of papers dealing with computational techniques to estimate optical flow, only a few authors have investigated conditions under which these constraints exactly model the velocity field, that is, the perspective projection on the image plane of the true 3-D velocity. These conditions are analyzed under different hypotheses, and the departures of the constraint equations in modeling the velocity field are derived for different motion conditions. Experiments are also presented giving measures of these departures and of the induced errors in the estimation of the velocity field.

Nosocomial septicemia caused by Serratia plymuthica

We report a case of nosocomial septicemia in a 79-year-old patient caused by Serratia plymuthica with no evident focus of infection. The patient was treated with gentamicin (40 mg every 8 h) during 10 days; clinical resolution of the infection was obtained after the 10-day treatment period.

Investigation of an outbreak of Salmonella typhi in a public school in Madrid

A typhoid fever outbreak affecting 54 school students occurred in a Public School of Móstoles, Madrid. The date of onset was 11 June 1991 and the last detected case was 8 July 1991. Salmonella typhi was cultured from blood and/or stool samples corresponding to 54 patients and one food-handler. There were no secondary cases detected. Epidemiological investigation suggested a salad or a custard as the common source. Patients and the food-handler were treated with ampicillin/amoxicillin for up to three weeks. There were seven relapses that were also treated with the same antibiotics with success. None were found to be excreting the organisms when tested after four months. All the Salmonella typhi isolated strains were phagetype 34, biotype Xylose +, Tetrationate Reductase + and harboured a similar 22 Mdal plasmid, they were also susceptible to the antibiotics tested.

[Follow-up of the quantitative serological response to the treatment of Helicobacter pylori infection in children]

BACKGROUND

The aim of the present study was to know the usefulness of a enzyme immunoanalysis (EIA) technique for the monitorization of the serologic to treatment of infection by Helicobacter pylori in Spanish children.

METHODS

17 children with digestive symptomatology in whom the diagnosis of infection by Helicobacter pylori was confirmed and eradication was objectified following a month of treatment with amoxycillin, metronidazole and Bismuth subcitrate were studied. In each patient a biopsy of the gastric mucosa was performed and a sample of serum was withdrawn for initial diagnosis and for control of eradication once treatment had finished (mean time between diagnosis and confirmation of eradication was 79.6 +/- 33.5 days). The samples of gastric mucosa were processed by standard methodology (histologic and/or culture). Serologic determinations (IgG and IgA) were carried out using a EIA technique (Pyloriset EIA-G and EIA-A; Orion Diagnostica).

RESULTS

In 12 of the 17 patients resolution of the clinical symptomatology was produced. A decrease in the levels of IgG was observed in 15 (88.2%) and of IgA in 14 (82.3%) of all the children studied. A significant difference was found between the mean values of the levels of IgG (p < 0.01) and IgA (p < 0.05) in the 17 patients at the time of diagnosis and following eradication.

CONCLUSIONS

In agreement with the present results the series study of the quantitative level of antibodies IgG and IgA versus Helicobacter pylori is shown as an adequate instrument for evaluating the response to treatment in pediatric patients.

Gliadin gene location and C-banding identification of Aegilops longissima chromosomes added to wheat

Gliadin protein components from Aegilops longissima were separated by two-dimensional electrophoresis. No equivalents for α-gliadin were noted. Addition and substitution lines of Ae. longissima in Triticum aestivum 'Chinese Spring' allowed the identification of homoeologous Gli-1 and Gli-2 loci in Ae. longissima chromosomes 1S1 and 6S1. The chromosomal constitution of the alien addition lines was ascertained by C-banding. In addition, C-banding analysis revealed that the Ae. longissima addition set was incomplete as only six distinct addition lines were identified. No evidence for structural modifications between the alien chromosomes in the lines and their Ae. longissima counterparts was found.Key words: gliadins, C-banding, gene location, Aegilops longissima, wheat.

Genetic mapping between Gli-B1 locus and a telomeric C-heterochromatin band in wheat

Using C-banding it has been possible to prove that the bread wheat varieties 'Holdfast' and 'CapelleDesprez' shows an intense band of telomeric heterochromatin on the short arm of chromosome 1B, while the variety 'Pané-247' presents a very thin band. Gliadin study using pH-acid electrophoresis revealed the existence of differences in the Gli-B1 locus in the three varieties. Analysis of the progeny of the (P x H) x CD hybrid revealed recombination between the heterochromatin C-band and locus Gli-B1, and allowed the genetic distance between the two markers to be calculated as 6.55±3.16 cMorgan. This is the first time the genetic distance from a locus to the chromosome telomere has been directly obtained in wheat. The heterochromatin C-band studied here gives us a cytological marker on chromosome 1B that can be used as a reference point in the localization of other genes.

[Corynebacterium jeikeium septicemia]

An adult male with non-Hodgkin lymphoma, who had been admitted to the hospital for more than one month and had received previous antibiotic therapy, developed Corynebacterium jeikeium septicemia. The organism was isolated in four blood cultures and it was multirresistant, being only sensitive to vancomycin, ciprofloxacin, norfloxacin and rifampin. The patient improved clinically and was bacteriologically cured with intravenous vancomycin therapy.

Chromosomal location by F1 monosomic analysis of endosperm proteins in bread wheat : 2. Two-dimensional fractionation of gliadins

The gliadin components from four bread wheat cultivars: Chinese Spring, Capelle Desprez, Holdfast and Pane-247 and their monosomic F1s for the chromosomes of homoeologous groups 1 and 6 have been analyzed by two-dimensional (2-pH) polyacrylamide gel electrophoresis. Chromosomal location of gliadin genes and the allelic differences were well established by analyzing the different F1 monosomic hybrids, electrophoretical patterns and differences in relative staining intensity. A new gliadin encoded by a gene located on chromosome 6B in Chinese Spring is described. The two-dimensional patterns of gliadin in the other three varieties and the chromosomal location of their genes are reported for the first time. Relationships between gliadins in the two-dimensional patterns and the traditional system for their nomenclature are discussed.

Chromosomal location by F1 monosomic analysis of endosperm proteins in bread wheat : 1. One-dimensional electrophoresis of glutenins and gliadins

A new methodology to determine the chromosomal location and allelic differences of endosperm proteins in common wheat cultivars by analysis of monosomic intervarietal hybrids is reported. Endosperm proteins from the common wheats Chinese Spring, Capelle Desprez, Holdfast and Pane 247 are studied using monosomic F1 for the chromosomes of homoeologous groups 1 and 6. The proteins were fractionated by two electrophoretical techniques, SDS- and A-PAGE. The use of monosomic offers a remarkable advantage over the utilization of intervarietal substitution lines, because it permits a quicker characterization and earlier evaluation of basic material to be used in breeding programmes.