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Biomedical subjects

S Hansson

Publications and source records attributed to S Hansson.

At least 73 records · Page 4Linked to original sources
PubMed1993

Surface analysis of four dental implant systems.

Dental implants obtained from four suppliers were analyzed by electron spectroscopy for chemical analysis and scanning electron microscopy. Three of the implants were delivered in a sterilized condition, while the fourth implant was delivered in a plasma-sprayed condition. The covering oxide layer consisted mainly of TiO2. Divalent and trivalent states of titanium were also detected, showing that TiO and Ti2O3 layers occurred. The thickness of the oxide formed on the plasma-sprayed implant was 3.4 nm. The oxide thicknesses of the sterilized implants were 4.6 +/- 0.4 nm. The surfaces of all samples were covered with organic contaminants. A strong fluorine signal was obtained from one sample, indicating that the supplier etches the implants in hydrofluoric acid. Calcium and zinc were found on the surfaces of all samples from one supplier, while calcium and silicon were found on the surfaces of the implants from another supplier. It is suggested that inorganic contaminants should be avoided because these species can possibly provoke the dissolution of titanium.

Calcium↗
PubMed1992

Pronounced detrusor hypercontractility in infants with gross bilateral reflux.

In this study the prevalence of bladder dysfunction in 18 children with gross bilateral reflux was investigated via cystometric recordings. In all except 1 infant maximal voiding detrusor pressure was 100 cm. or greater water (range 86 to 244). Pronounced instability during filling (overt instability) with pressure waves above baseline (mean 65 cm. water, range 42 to 194) was found in 9 infants. Another 5 children had evidence to suggest an uninhibited bladder, not manifested as unstable contractions during filling but as covert instability, meaning that the first unstable contraction was transformed into a premature and forceful voiding contraction. The high detrusor pressures found in 18 children with gross bilateral reflux during the voiding phase but also during the filling phase in half of the children suggest that a hypercontractile detrusor may be a contributory factor for the development of reflux even in this age group.

Female↗
PubMed1992

Characteristics and prognosis of hospital-treated obstructive bronchitis in children aged less than two years.

In a prospective study 101 children aged less than 2 years (median age 10 months), were examined the first time they were admitted to a paediatric ward for asthmatic symptoms. Two-thirds were boys and 58 had parents or siblings with allergic symptoms. During winter-spring, respiratory syncytial (RS) virus was verified in 50% of children. Other viral agents were adenovirus, parainfluenza 3, coxsackie B 2, ECHO 6 and rotavirus. At the acute stage, 54% of the children displayed changes on pulmonary X-ray. The total IgE value was greater than or equal to +2 SD score units in 14 children. At reinvestigation after 3-4.5 years, when the children were aged 3.3-6.3 years, 53% were free from asthmatic symptoms; the median age for the last episode was 2 years. A total of 33% had mild asthma, 8% moderate and 6% severe asthma. The factors which correlated significantly with persistent asthma were: (1) The need for daily medication for at least 6 months. (2) A young age in conjunction with the first wheezing episode and on the first admission to a paediatric ward because of asthmatic symptoms. (3) Other past or present atopic symptoms. Heredity, tobacco smoking at home, having a furry pet, RS virus infection, or high total IgE at the time of the first admission did not correlate significantly with the persistence of asthma 3-4.5 years later. The results emphasize the good overall prognosis of wheezing in early childhood, even when the wheezing is severe enough to lead to inpatient treatment.

Age Factors↗
PubMed1992

Urinary incontinence in children and associated problems.

Urinary tract infections are common during childhood. The association to bladder dysfunction was studied in two different populations of children. First, the prevalence of UTI in 3553 7-year-old schoolchildren with and without incontinence was assessed. Isolated bed wetting was not associated with UTI. In combined night and day wetting or day wetting alone there was a strong correlation to previous UTI. Secondly, the majority of girls with covert bacteriuria had clinical and urodynamic evidence of bladder dysfunction.

Child↗
PubMed1991

Association between urinary symptoms at 7 years old and previous urinary tract infection.

The association between current micturition habits and previous urinary tract infection was analysed among 3553 school entrants aged 7 years by means of a questionnaire. A high incidence of urinary infection, confirmed by urine culture, was found (145 (8.4%) in the 1719 girls and 32 (1.7%) in the 1834 boys). There was a significant association between current symptoms that were suggestive of disturbed bladder function and previous urinary tract infection, but only among girls who were over 3 years of age at the time the first episode was diagnosed.

Age Factors↗
PubMed1990

Micturition habits and incontinence in 7-year-old Swedish school entrants.

The prevalence of incontinence in children has been extensively studied, but knowledge of other bladder symptoms is lacking in a healthy child population. The micturition habits of 3556 7-year-old school entrants were surveyed by a questionnaire supplemented by telephone interviews. One or more symptoms of a disturbed bladder function was reported in 26%, but most of these had moderate urgency as a sign of incomplete voluntary bladder control. Isolated bedwetting occurred in 2.8% of the girls and 7.0% of the boys, whereas nocturnal incontinence combined with daytime wetting was equally common in both sexes, 2.3% and 2.0% respectively. Diurnal incontinence was reported in 6.0% of the girls and 3.8% of the boys and was usually combined with other symptoms. The frequency of micturition in children without symptoms of bladder disturbance and with no previous urinary tract infection was 3-7 times per day.

Child↗
PubMed1990

Follicular cystitis in girls with untreated asymptomatic or covert bacteriuria.

Nodular changes of the bladder mucosa, that is cystitis follicularis or cystitis cystica, are found in 2 to 9% of all children with urinary tract infections. The nodules are composed of lymphoid aggregates, resembling Peyer's patches in the intestine. Children with this finding are considered to have a poor short-term prognosis with a marked tendency for recurrent infections. Screening programs for bacteriuria have revealed that a few per cent of the female population are bacteriuric without symptoms of overt disease. Of 59 girls followed with untreated asymptomatic bacteriuria 52 had nodular changes of the bladder mucosa at cystoscopy. Biopsy was performed in 22 girls, and revealed lymphocytic infiltration in 19 and follicular formation in 11. The nodular changes persisted when bacteriuria continued but disappeared in patients who became abacteriuric. This finding demonstrates the reversibility of the changes, and supports the assumption that they are secondary to the presence of bacteria and not a primary lesion.

Bacteriuria↗
PubMed1990

Lower urinary tract dysfunction in girls with untreated asymptomatic or covert bacteriuria.

A total of 50 to 80% of all girls with asymptomatic or covert bacteriuria will have recurrences after antibacterial treatment. Deficient bladder emptying is an important factor predisposing to urinary infections. We investigated lower urinary tract function in 57 girls with untreated so-called asymptomatic bacteriuria. Detailed questioning revealed a high frequency of symptoms, such as urgency and incontinence. The symptoms were not acute and no patient had dysuria. The urinary flow curve pattern indicated bladder emptying problems in 42% of the girls and residual urine of greater than 5 ml. was seen in 71%. Cystometry revealed consistent detrusor instability in 75% of the patients. Lower urinary tract dysfunction may explain the marked tendency for recurrent infection after treatment of asymptomatic bacteriuria. With a detailed history, and noninvasive determination of urinary flow and residual urine, these abnormalities are easily detected. Bladder rehabilitation may offer a new method of treatment for these patients.

Bacteriuria↗
PubMed1989

Untreated asymptomatic bacteriuria in girls: I--Stability of urinary isolates.

OBJECTIVE: To assess the frequency of spontaneous changes of bacterial strains in patients with untreated asymptomatic bacteriuria. DESIGN: Retrospective analysis of samples from all patients with renal scarring and random sample of patients with normal kidneys. SETTING: Outpatient clinic for children with urinary tract infections. PATIENTS: 54 Girls aged 3.3-15.5 years with untreated asymptomatic bacteriuria caused by Escherichia coli. INTERVENTION: None. END POINT: Change in bacterial strain. MEASUREMENTS AND RESULTS: Serotyping and electrophoretic analysis of sequential bacterial isolates, representing 151 patient years of untreated asymptomatic bacteriuria. A total of 24 changes of strain were identified. Eleven were related to medical interference such as treatment of other infections with antibiotics. CONCLUSIONS: Spontaneous changes of strain were uncommon, one change in 11.6 patient years, and thus are not a characteristic feature of the course of asymptomatic bacteriuria.

Adolescent↗
PubMed1989

Untreated asymptomatic bacteriuria in girls: II--Effect of phenoxymethylpenicillin and erythromycin given for intercurrent infections.

OBJECTIVE: To investigate the effects of phenoxymethylpenicillin and erythromycin on urinary isolates from patients with untreated asymptomatic bacteriuria. DESIGN: Retrospective study of subgroup of patients from cohort followed up till the end of 1986. SETTING: Outpatient clinic for children with urinary tract infections. PATIENTS: 51 Girls aged under 15 with untreated asymptomatic bacteriuria. INTERVENTIONS: Before 1982 intercurrent infections (mostly tonsillitis or otitis) were treated with phenoxymethylpenicillin; after 1982 erythromycin treatment was preferred. END POINTS: Change of bacterial strain in urinary tract and symptomatic recurrences of disease. MEASUREMENTS AND MAIN RESULTS: Bacteria identified by serotype and electrophoretic type and compared before and after antibiotic treatment. Bacteriuria eradicated and replaced by new strains in most patients treated with phenoxymethylpenicillin, leading to symptomatic recurrences in about 15%. Conversely, patients given erythromycin rarely showed change in bacteriuria and none suffered symptomatic recurrence. CONCLUSIONS: In girls with untreated asymptomatic bacteriuria the use of phenoxymethylpenicillin for intercurrent infections may lead to a change of urinary bacteria and leave them at substantial risk of acute pyelonephritis. With erythromycin this risk is small (2/20 courses in this series).

Adolescent↗
PubMed1989

Pivmecillinam in long-term prophylaxis to girls with recurrent urinary tract infection.

Pivmecillinam in a single bed-time dose of 5-10 mg/kg was given as long-term prophylaxis to 20 girls with recurrent bacteriuria for a total of 228 months. Symptomatic recurrences occurred in 4 girls, i.e. 1.8 infections/100 months as compared to 17/100 months during the year preceding the study. The frequency of positive urine cultures during prophylaxis was 11%. 10 of the 15 isolates were enterococci, resistant to mecillinam. In rectal swabs examined for the presence of aerobic gram-negative bacteria, enterobacteria were isolated in 78% with a low rate of resistance to mecillinam (11%). Thus pivmecillinam offered effective protection against recurrent urinary tract infections, and did not tend to select resistant enterobacteria in the bowel, but allowed resistant enterococci to cause a few symptomatic infections.

Adolescent↗
PubMed1989

Trimethoprim-sulphadiazine prophylaxis in children with vesico-ureteric reflux.

The efficacy of long-term low-dose prophylaxis with co-trimazine (1-2 mg trimethoprim and 4.5-9 mg sulphadiazine per kg body weight) was studied in 55 children with dilated vesico-ureteric reflux. Of 44 girls, there were 13 with break-through urinary tract infection, all caused by resistant bacteria and in all but one case of pyelonephritic type. The recurrence rate was 1.5/100 treatment months. In 11 boys, there were no break-through infections in 311 treatment months. Co-trimazine was thus an effective drug for prevention of urinary tract infection in this high-risk population.

Anti-Infective Agents, Urinary↗
PubMed1989

Untreated bacteriuria in asymptomatic girls with renal scarring.

Recurrences of bacteriuria after treatment occur in 50% to 80% of asymptomatic patients. Previous experience with short-term treatment as well as long-term prophylaxis has been disappointing, with a significant risk of infections, ie, development of symptoms after treatment. Results with nontreatment are described in this report with reference to clinical course, renal growth, and glomerular filtration rate in 26 asymptomatic girls with established renal scarring and bacteriuria. Acute pyelonephritis was not seen in those with continuing bacteriuria or spontaneous clearance. Neither in scarred nor in unscarred kidneys did the duration of bacteriuria influence renal growth or glomerular filtration rate. Asymptomatic patients with bacteriuria may gain from nontreatment and may have a reduced risk of pyelonephritic attacks.

Adolescent↗
PubMed1985

Accelerated oxide growth on titanium implants during autoclaving caused by fluorine contamination.

Titanium implants were occasionally found to be strongly discoloured after autoclaving. The discolouration is shown to be due to an accelerated growth of the surface oxide that covers the implants. Oxide thicknesses up to 650 A have been observed, i.e. more than ten times thicker than on normal implants. By applying surface sensitive spectroscopies (SIMS and XPS or ESCA) it is also shown that these oxide films contain considerable amounts of fluorine, alkali metals and silicon. Screening tests with alkali-halide solutions identify fluorine as the impurity responsible for the accelerated oxide growth. Discolouration after autoclaving can be observed for fluorine contaminations down to the ppm level. In those cases where discolouration was observed in the clinical situation, the source of fluorine was the textile cloths in which the titanium implant storage box had been wrapped during the autoclaving procedure. The cloths contained residual Na2SiF6 which had been used as an additive to the rinsing water used in the last step of the cloth laundry procedure. Since the biocompatibility of titanium implants is closely related to their surface oxides it is advisable to avoid all sources of fluorine in the implant preparation procedures.

Color↗
PubMed1985

Autonomic dysfunction in experimental allergic neuritis.

Beat-to-beat variation (R-R variation) in the electrocardiogram was studied in experimental allergic neuritis in the Sprague-Dawley rat. Reduced R-R variations were found in 2 of 10 animals, probably as a sign of autonomic dysfunction. The vagal nerves from these two animals, studied in vitro, showed disturbed conduction. In one animal prolonged conduction latencies to supramaximal electrical stimuli were found. Vagal nerves from controls and from animals without clinical symptoms showed normal conduction. Histologically, the vagal nerves from affected animals showed a slight inflammatory cell infiltration and signs of demyelination but there was no evidence of involvement of the brainstem vasomotor nuclei. Thus, we suggest that the autonomic dysfunction in experimental allergic neuritis, measured as reduced R-R variations, is caused by a peripheral vagal neuropathy.

Animals↗