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H Saxén

Publications and source records attributed to H Saxén.

At least 19 recordsLinked to original sources
PubMed2002

Recurrent urinary tract infections in infancy: relapses or reinfections?

Seventeen infants with an index episode of pyelonephritis caused by Escherichia coli were monitored for 18 months for recurrent urinary tract infections (UTIs). All the infants had at least 1 recurrent UTI caused by the same pathogen. Twenty-six recurrent UTI episodes were recorded. The 40 E. coli strains available were analyzed by multiplex polymerase chain reaction for 3 alleles (classes I-III) of the papG gene and by pulsed-field gel electrophoresis (PFGE) after genomial digestion by XbaI. Of the 17 index strains, 12 (71%) carried the papG gene; 67% of these strains had class II alleles. In recurrent UTI isolates, the papG-positive E. coli appeared in 16 (70%) of 23 isolates. The proportion of all recurrent isolates available that represented a strain previously encountered (indistinguishable or highly similar in PFGE) in the same infant was 65%. Our results suggest that most recurrent UTIs in infants are endogenous relapses rather than reinfections caused by new organisms.

Adhesins, Escherichia coli↗
PubMed2001

Predictive factors associated with significant urinary tract abnormalities in infants with pyelonephritis.

BACKGROUND: Major urinary tract abnormalities are detected in 20 to 40% of infants with acute pyelonephritis (APN). Early detection of structural defects is essential for protecting the kidneys from reinfection and subsequent scarring. The purpose of this study was to investigate whether any factors present during the acute phase of infection could predict the presence of existing significant urinary tract abnormalities in infants. METHODS: A prospective study of 180 infants, aged 1 to 24 months, with APN was conducted. Blood and urine samples were collected. Renal ultrasound (US) was performed within 0 to 6 days from admission. Final diagnosis of the urinary tract anatomy was elucidated using the results of two or more radiologic imaging studies. RESULTS: Risk factors for the presence of significant urinary tract abnormalities in infants were pathogens other than Escherichia coli in urine [relative risk (RR) 3.4, 95% confidence interval (CI) 2.2 to 5.3; P = 0.001], positive blood culture (RR 2.3, 95% CI 1.3 to 4.0; P = 0.039), young age (1 to 6 months) (RR 2.2, 95% CI 1.3 to 3.9; P = 0.004), lack of papG adhesin genes of E. coli in urine (RR 2.1, 95% CI 1.2 to 3.9; P = 0.016) and abnormal renal US (RR 2.0, 95% CI 1.2 to 3.4; P = 0.008). CONCLUSIONS: Infants 1 to 6 months of age with APN caused by bacteria other than E. coli or by papG-negative E. coli strain, positive blood culture and abnormal renal US carry an increased risk for significant urinary tract abnormalities and need enforced follow-up.

Acute Disease↗
PubMed2001

Genomic identity of pyelonephritogenic Escherichia coli isolated from blood, urine and faeces of children with urosepsis.

Chromosomal genotypes of Escherichia coli isolates from blood, urine and faeces of infants with urosepsis were studied to find possible clonality of the isolates. The isolates were analysed by PCR for class I, II and III alleles of the pyelonephritis-associated adhesin gene papG. The macrorestriction profiles of the papG-positive isolates were analysed by pulsed-field gel electrophoresis and their O serogroups were determined. Genetically identical E. coli isolates from the blood, urine and faeces of the same infant were found in 8 of 10 infants. This finding confirmed the results of previous phenotypic studies that the reservoir of pyelonephritogenic E. coli is indeed the colon.

Adhesins, Escherichia coli↗
PubMed2000

Predominance of class II papG allele of Escherichia coli in pyelonephritis in infants with normal urinary tract anatomy.

P-fimbrial genotypes of Escherichia coli strains and their possible association with urinary tract abnormalities were studied in infants with pyelonephritis. A total of 153 urinary E. coli strains were analyzed by polymerase chain reaction for class I, II, and III alleles of the pyelonephritis-associated adhesin gene papG. Strains with any class II papG alleles were found significantly more often in infants with normal anatomy and function or in infants with clinically insignificant abnormalities than they were in infants with significant abnormalities (90 of 119 vs. 14 of 34 infants; P<. 001). On the other hand, strains without any papG alleles were found significantly more often in infants with major urinary tract abnormalities (11 of 34 vs. 17 of 119 infants; P=.016). Our genotypic findings indicate that, especially in infants with a normal urinary tract, infection is caused by more-virulent E. coli than is present in infants without a normal urinary tract. This virulence could be due to expression of pyelonephritogenic P fimbriae by an infecting E. coli strain.

Adhesins, Escherichia coli↗
PubMed2000

Bacteriology of histopathologically defined appendicitis in children.

BACKGROUND: Acute appendicitis is the most common surgical emergency in childhood. However, the pathogenesis and detailed microbiology are obscure. OBJECTIVE: To determine in detail the bacterial etiology of appendicitis in children in relation to the histologic tissue pathology. STUDY DESIGN: Tissue samples obtained at surgery from 41 children with suspected acute appendicitis were examined histologically and by culture for aerobic and anaerobic bacteria. The patients were analyzed according to histopathologic and clinical findings. RESULTS: Aerobic and anaerobic species were isolated from 40 of 41 (98%) samples; on average, 14.1 isolates per specimen (10.4 anaerobes and 3.7 aerobes). Specimens from patients with gangrenous appendices yielded significantly higher numbers of anaerobic isolates per specimen than did specimens from patients with healthy appendices (11.7 vs. 7.7; P < 0.01). Bacteria belonging to the Bacteroides fragilis group were the most frequently isolated anaerobic microorganisms (95%). Other organisms frequently isolated in all histology groups were Peptostreptococcus micros (66%), Bilophila wadsworthia (63%), Fusobacterium nucleatum (44%), Eggerthella lenta (44%) and a hitherto undescribed bile-resistant, pigment-producing Gram-negative rod (41%). Of the aerobes Escherichia coli (88%) and Streptococcus anginosus group (former Streptococcus "milleri" group) organisms (61%) were the most frequent findings. CONCLUSIONS: The shift from histologically normal toward gangrenous appendices was clearly associated with markedly elevated anaerobic bacterial counts in terms of species. The unusually high frequencies of B. wadsworthia (75%) and the hitherto undescribed bile-resistant, pigment-producing Gram-negative rod (56%) in gangrenous appendices represent unique and different findings from those reported in adults.

Adolescent↗
PubMed1999

Oral prednisolone is an effective adjuvant therapy for acute otitis media with discharge through tympanostomy tubes.

OBJECTIVE: To determine the efficacy of a short course of oral prednisolone as an adjuvant therapy for acute otitis media draining through tympanostomy tubes. STUDY DESIGN: In a randomized, double-blind, placebo-controlled study, children with acute discharge (<48 hours) through tympanostomy tubes received either prednisolone (2 mg/kg/d; n = 23) or placebo (n = 27) for 3 days. All children received amoxicillin/clavulanate (40/10 mg/kg/d) for 7 days. The children were examined daily at the study clinic until the drainage ceased. RESULTS: The median duration of otorrhea in the prednisolone group was 1.0 days (25% to 75% range, 1.0 to 2.0 days), compared with 3.0 days (25% to 75% range, 2.0 to 4.0 days) in the children receiving placebo (P <.001). The duration of otorrhea was </=2 days in 21 (91%) children in the prednisolone group, compared with 8 (30%) children in the placebo group (P <.001). CONCLUSIONS: Oral prednisolone appears to be modestly effective adjuvant therapy for acute otitis media with discharge through tympanostomy tubes in children. Further studies seem warranted to determine whether short-term use of steroids early during the course of acute otitis media would also reduce the duration of middle ear effusion in children with intact tympanic membranes.

Acute Disease↗
PubMed1999

Randomized, placebo-controlled double blind study on the efficacy of influenza immunization on absenteeism of health care workers.

BACKGROUND: In healthy adults influenza immunization reduces absenteeism caused by respiratory infections, but data on its efficacy among health care workers are scarce. OBJECTIVE: To determine the effect of the conventional inactivated influenza A vaccine on reducing absenteeism related to respiratory infections among pediatric health care providers. STUDY DESIGN: A randomized, placebo-controlled, double blind study on vaccine efficacy was conducted in two pediatric hospitals during the winter season 1996 to 1997. The primary endpoint was days of work lost from the hospital because of respiratory infections. The documentation of absenteeism was based on personal sickness logs. RESULTS: Of the 547 randomized vaccinees 427 (78%) persons completed the 4-month follow-up and returned the sickness logs. Immunization failed to reduce episodes of respiratory infections (1.8 episodes/study period among vaccinees vs. 2.0 among controls). Similarly the vaccine failed to affect the total number of days the vaccinees suffered from respiratory infections (13.5 days vs. 14.6 days, respectively). However, days of work lost because of respiratory infections (1.0 days vs. 1.4 days, respectively, P = 0.02) and especially total numbers of days the study persons felt themselves unable to work when either on or off duty (2.5 days vs. 3.5 days, P 0.02) were significantly decreased. CONCLUSION: Influenza vaccination reduced absenteeism related to respiratory infections by 28%. We therefore believe that routine annual influenza immunizations should be recommended to health care providers working in pediatric settings.

Absenteeism↗
PubMed1999

[Tetanus].

Explore the source record for details and available documents.

Clostridium tetani↗
PubMed1998

Single-dose and steady-state pharmacokinetics of a new oral suspension of ciprofloxacin in children.

OBJECTIVE: Quinolones are used ever increasingly in pediatrics, although officially they are still contraindicated. Lack of evidence of arthropathic effects in human offspring favors their use, but little is known about the pharmacokinetics of oral or parenteral ciprofloxacin in children, especially those without cystic fibrosis. DESIGN: We studied 16 non-cystic fibrosis patients ranging in age from 0.3 to 7.1 years to whom the new suspension formulation of ciprofloxacin (10 mg/kg body weight) was given orally three times daily. Single-dose and steady-state pharmacokinetic parameters were elucidated. RESULTS: Ciprofloxacin was rapidly absorbed. The maximum plasma concentrations, with the means varying from 1.7 to 3.6 mg/L, were reached within 1 hour, almost regardless of whether single-dose administration or steady state. The mean oral clearance was lower in children <6 years of age than in those >/=6 years. Terminal half-life values, with the means varying only between 4.2 and 5.1, suggest that dosing recommendations based on body weight are pertinent, although caution should be exercised in small infants. No arthropathic or other adverse events attributable to ciprofloxacin suspension were observed. CONCLUSION: A dose of the suspension form of ciprofloxacin of 10 mg/kg body weight given orally three times daily seems appropriate in children, provided the drug is clearly indicated.

Administration, Oral↗
PubMed1997

Group A streptococcal outbreak of perianal infection in a day-care centre.

Within 9 days in a day-care centre of 20 children 3 cases and 2 suspected cases of perianal infection (PAI) were revealed. The causative agent for PAI was confirmed to be beta-haemolytic group A streptococcus (GAS). The isolates were further characterized by T- and M-serotyping, conventional restriction endonuclease analysis (REA) and pulsed field gel electrophoresis (PFGE). The typing methods revealed that all outbreak isolates were of same T28R28-serotype and genetically identical. Unrelated, control GAS isolates of the same serotype differed genetically from the outbreak isolates indicating that a single clone had caused the perianal infections.

Anus Diseases↗
PubMed1997

Characteristics of an unusual anaerobic pigmented gram-negative rod isolated from normal and inflamed appendices.

During our studies of the bacterial etiology of appendicitis, we often isolated a previously undescribed anaerobic gram-negative rod. This organism resembled the Bacteroides fragilis group because it was resistant to bile and because of its special-potency-disk pattern (resistant to vancomycin, kanamycin, and colistin), but unlike the B. fragilis group, this bacterium produced brown pigment on media containing hemolysed blood. The cellular fatty acid pattern, with iso-C15:0 being the predominant acid, was most closely related to the fatty acid profile of Porphyromonas species; however, this organism differed from Porphyromonas species by being bile-resistant and by not producing butyrate as a metabolic endproduct. Enzymatic activities of 31 isolates were determined with use of the API ZYM system and Rosco diagnostic tablets. These profiles were different from those of Prevotella, Porphyromonas, and related species. This organism was isolated from 40% of appendiceal tissue samples; no obvious qualitative or quantitative difference in rates of isolation from patients with inflamed or normal appendices was observed.

Adolescent↗
PubMed1996

Escherichia coli and appendicitis: phenotypic characteristics of E. coli isolates from inflamed and noninflamed appendices.

Two hundred four appendiceal isolates for Escherichia coli from 146 patients with either inflamed appendices (IA) (110 patients) or noninflamed appendices (NA) (36 patients) were characterized. Strains with P fimbriae were detected in 27% of IA and 31% of NA whereas type 1C-fimbriated strains were found only in IA (13%). Four serotypes, three with K5 antigens (O18:K5, O25:K5:H1, and O75:K5:H-) and one with K1 antigen (O75:K1:H7), were isolated only from IA (20 [18%] of 110); O25:K5:H1 was the most common serotype (isolated from 11 IA [10%]). Fecal isolates from the patients with IA resembled their corresponding appendiceal isolates rather than fecal isolates from patients with NA; this finding suggests that colonization of the gut by virulent E. coli--such as a hemolysin-producing, type 1C-fimbriated, P-fimbriated O25:K5:H1 serotype--may be a prerequisite for the development of appendicitis.

Adolescent↗
PubMed1996

Biological characterization of Campylobacter fetus lipopolysaccharides.

Lipopolysaccharides (LPS) of three strains of Campylobacter fetus (subspp. fetus and venerealis, and serotypes A and B), a bacterium of veterinary importance but also a cause of various infections in humans, were assessed for their ability to induce mitogenicity, gelation of Limulus amebocyte lysate, lethal toxicity in mice, and pyrogenicity in rabbits. All C. fetus LPS exhibited activities lower than those of Salmonella typhimurium LPS. LPS of C. fetus subsp. fetus serotype A had the lowest activity in all assays. Since the majority of C. fetus subsp. fetus isolates from humans are serotype A, the lower biological activities of this LPS may aid the pathogenesis of such strains. The lower activities of C. fetus LPS compared with those of S. typhimurium LPS may reflect the presence of longer fatty acid chains in the lipid A of C. fetus LPS, whereas interstrain differences in C. fetus LPS bioactivities may be related to some property influenced by composition of the saccharide moiety.

Animals↗
PubMed1996

Nonlinear time series analysis by neural networks: a case study.

This paper presents a neural network approach to time-series analysis of a univariate nonlinear system. Feedforward networks are studied, and an appropriate network size is determined by different criteria computed on the basis of the performance of the models on the training and test sets. The analysis and conclusions drawn are supported by studies of the phase portraits of the models. By a proper choice of network size, the problems of over-parameterization are demonstrated to be avoided. The overfitting observed for larger networks is analyzed and the underlying reasons for their worse generalization capabilities are explained. Finally, some observations are made on the approximation provided by an oversized network with weights determined by an incomplete (interrupted) training and that of the optimal-sized network.

Cybernetics↗
PubMed1995

Persistence of a multiresistant clone of Staphylococcus epidermidis in a neonatal intensive-care unit for a four-year period.

A cluster of cases of Staphylococcus epidermidis bacteremia in a neonatal intensive-care unit (NICU) during 1991 raised the question of whether these infections were caused by a single strain. Sixty-seven isolates of S. epidermidis from blood cultures of 56 neonates treated in the NICU between 1986 and 1992 and 54 control strains from other patients with bacteremia were characterized by three typing methods: antibiogram, plasmid profile, and ribotype. Plasmid profiles and ribotype patterns indicated that 11 (16%) of the 67 episodes of S. epidermidis bacteremia in the NICU were caused by a single strain. Although this epidemic strain did not account entirely for the increase in the incidence of bacteremia in the NICU, it did persist for 4 years during the study period. Other clones responsible for smaller outbreaks were also found. These results suggest that S. epidermidis cross-infections are very common in the NICU setting.

Bacteremia↗