Prenatal karyotyping of choroid plexus cysts

OBJECTIVES

A retrospective, descriptive study of 50 cases with choroid plexus cysts diagnosed by ultrasonography.

METHODS

All case charts were studied and additional information was collected regarding children born outside Uppsala.

RESULTS

All 50 cases were offered a test for chromosome aberrations, 46 accepted and were tested by chorion villi sampling or amniocentesis. In ten cases additional malformations were found, including one trisomy 13 and one trisomy 18. No relationship was found between the diameter, bilaterality or the complexity of the cyst.

CONCLUSIONS

Fetus with choroid plexus cysts should be examined carefully by ultrasonography. Since the complication risk of invasive diagnostic procedures is very small these patients may be offered a test for chromosomal aberrations.

Anaphylactoid reactions and nephrotic syndrome--a considerable risk during factor IX treatment in patients with haemophilia B and inhibitors: a report on the outcome in two brothers

Anaphylaxis/anaphylactoid reactions have recently been reported after few treatments with factor IX concentrates in patients with haemophilia B at the same time as inhibitors to factor IX were demonstrated. In some of these cases nephrotic syndrome has appeared during immune tolerance induction (ITI) with high doses of factor IX concentrates. Gene deletions seem to be associated with a high risk of developing antibodies to factor IX. This report presents two brothers with deletion of 1 bp in exon f of the factor IX gene. Both showed anaphylactoid reactions and they were desensitized using slow i.v. injections of factor IX. At the time of anaphylaxis, inhibitors of factor IX in a low titre could be demonstrated. The elder brother responded well after a short time on ITI and has no spontaneous bleedings on regular prophylaxis although in a somewhat higher dose than expected. On the other hand, in spite of comparable regimens, the younger brother has so far been resistant to ITI. Moreover, during treatment with extremely high doses of factor IX concentrate he developed nephrotic syndrome which only slowly subsided after treatment with corticosteroids and withdrawal of factor IX.

Disappearance of vesicoureteral reflux in children

OBJECTIVE

To describe the disappearance of reflux in children with vesicoureteral reflux, in whom there are presently no population-based long-term studies.

DESIGN

An unselected cohort of children with reflux detected after their first known symptomatic urinary tract infection was followed up prospectively for up to 15 years.

SETTING

A single children's hospital in a distinct geographical area at which most children with symptomatic urinary tract infection were treated.

PATIENTS

Two hundred thirty children--173 girls and 57 boys--with unilateral (n=130) and bilateral (n=100) reflux. Dilated reflux (grades III-V) was found in 54 patients (23.5%). The frequency of reflux was 34% in girls and 31% in boys who were examined after urinary tract infection.

MAIN OUTCOME MEASURE

Disappearance of reflux.

RESULTS

The probability of spontaneous disappearance of reflux was estimated using Kaplan-Meier survival curves based on 164 children who underwent multiple voiding cystourethrographies. There was a marked tendency for disappearance of reflux, with 73% of children with dilated reflux having no or only grade I reflux after 10 years. Shorter persistence of reflux was found in children with undilated reflux at the initial investigation and in boys compared with girls. However, age at first investigation was not related to the rate of disappearance, and there was no difference between children with bilateral compared with unilateral reflux.

CONCLUSIONS

This study of an unselected group of children with urinary tract infection shows a favorable long-term outcome concerning disappearance of reflux. In children with dilated reflux, this tendency was more pronounced than previously reported.

Urodynamic pattern in infants with urinary tract infection

PURPOSE

We studied the urodynamic pattern in infants with urinary tract infection and evaluated the influence of the infection.

MATERIALS AND METHODS

Cystometry was combined with voiding cystourethrography (video cystometry) in 90 male and 68 female infants admitted to the hospital with first time urinary tract infection. Evaluation was performed 1 to 30 days (mean 11) and 32 to 78 days (mean 46) after diagnosis in 93 and 65 infants, respectively.

RESULTS

Bladder instability was found in two-thirds of male and female infants. Compared to older children male infants had high voiding detrusor pressure and low bladder capacity (hypercontractility). Female infants also had increased voiding pressure levels but they were significantly lower than those in male infants. The voiding detrusor pressure was even higher in both sexes when evaluation was delayed after the infection.

CONCLUSIONS

Infants with urinary tract infection have bladder instability and hypercontractility compared to older children. Bladder hypercontractility was less pronounced early after infection, suggesting that the infectious agents inhibit detrusor muscle contractility. Whether hypercontractility is a normal urodynamic pattern in infancy or represents bladder dysfunction can only be addressed by urodynamic studies of healthy infants.

Dopamine produced by the stomach may act as a paracrine/autocrine hormone in the rat

Dopamine (DA) has been suggested to be a protective factor in the gastrointestinal tract but neither a source of DA nor its exact targets of action have been identified. In this study, we demonstrate high levels of DA (and DOPA) which persist after chemical sympathectomy in the gastric juice of rats. Immunostaining and in situ hybridization histochemistry reveal the presence of tyrosine hydroxylase (TH), DA transporter and vesicular monamine transporters in the acid-producing parietal cells. Like DA, TH enzyme activity remains after chemical sympathectomy. We also demonstrate active reuptake and storage of DA that indicates a regulated release of this neurohormone from parietal cells. DA D1b receptor mRNA is the most abundant DA receptor subtype in gastric and duodenal epithelium. Therefore, we suggest that selective DA D1b receptor agonists may be useful adjuncts in the treatment of duodenal and gastric ulcers. Gastric epithelia possess the hallmarks of functional DA neuroendocrine cells, suggesting that DA has an important role in self-protective mechanisms of the gastrointestinal tract. These findings should allow elucidation of DA role in normal and disease states in the stomach and duodenum.

Expression of the CB1 and CB2 receptor messenger RNAs during embryonic development in the rat

We mapped the distribution of CB1 and CB2 receptor messenger RNAs in the developing rat to gain insight into how cannabinoids may affect embryogenesis. In situ hybridization histochemistry studies were done using riboprobes specific for CB1 or CB2 receptor messenger RNAs. We found that CB1 and CB2 receptor messenger RNAs are expressed in the placental cone and in the smooth muscle of the maternal uterus at the earliest gestational periods studied [from eight days of gestation (E8) through E12]. In the embryo, as early as E11, CB1 receptor messenger RNA is expressed in some cells of the neural tube and, at later embryological stages (from E15 to E21), in several distinct structures within the central nervous system. In addition, high levels of CB1 receptor messenger RNA were also found in areas of the peripheral nervous system such as the sympathetic and parasympathetic ganglia, in the retina and in the enteric ganglia of the gastrointestinal tract. In addition to neural structures, high levels of the CB1 receptor messenger RNA were also present in two endocrine organs, the thyroid gland and the adrenal gland. On the other hand, CB2 receptor messenger RNA is expressed exclusively in the liver of the embryo as early as E13. The region-specific expression of CB1 and CB2 receptor messenger RNAs suggests that these receptors have a functional role during embryogenesis.

Low bacterial counts in infants with urinary tract infection

We analyzed the number of colony-forming units in urine cultures obtained by suprapubic aspiration in a group of 366 unselected infants with symptomatic urinary tract infection to relate these findings to factors such as pyuria and vesicoureteric reflux. Seventy-three (20%) of 366 infants had fewer than 100,000 colony-forming units per milliliter. Such low counts were significantly related to low numbers of leukocytes in the urine. Vesicoureteric reflux was equally distributed among children, irrespective of the number of bacteria in quantitative culture. The findings emphasize the importance of sampling technique; in infants, the method of choice is suprapubic aspiration, or catheterization, which eliminates the risk that urinary tract infection is overlooked because of low bacterial counts.

The natural history of bacteriuria in childhood

Urinary tract infections are common during infancy and childhood but are easily overlooked because of the unspecific symptoms. Prevention of renal scarring and its potential long-term consequences is possible but requires an increased awareness of the diagnosis, the imaging revealing anomalies within the urinary tract, and the long-term supervision. This should include any possibility of the child having pyelonephritic recurrences, which should be treated without delay; however, asymptomatic bacteriuria in infants and children is an innocent condition and screening is not recommended.

Epidemiology of chronic renal failure in children: a report from Sweden 1986-1994. Swedish Pediatric Nephrology Association

In a national survey, chronic renal failure (CRF) in Swedish children was studied during the period 1986-1994; 118 children (72 boys, 46 girls) with CRF, defined as a glomerular filtration rate below 30 ml/min per 1.73 m2 body surface area, were identified. The median annual incidence of CRF was 7.7 and that of terminal renal failure (TRF) 6.4 per million children. The prevalence of preterminal renal failure decreased from 29 to 21 per million children over the study period, while the prevalence of TRF increased from 17.8 in 1986 to 38 per million children in 1994. The increase in TRF prevalence was due to a lower incidence of deaths due to uremia and a slightly increased incidence of TRF compared with an earlier study period, 1978-1985. The results point to a more active treatment of uremia in Sweden now than during the period 1978-1985. The congenital causes of CRF (renal malformations, obstructive conditions, and hereditary disorders) accounted for 67.5% of all cases, which is high compared with data from other countries. No child with non-obstructive pyelonephritis as a cause of CRF was identified. Age at detection of CRF and time from detection of CRF to TRF were studied. As a high proportion of children, 42%, reached 16 years of age without entering TRF, the value of presenting time from CRF to TRF for the remaining individuals is questionable. There were only minor differences in primary renal disease, age at presentation, and time from CRF to TRF when the study results were compared with those from 1978-1985.

A novel nonneuronal catecholaminergic system: exocrine pancreas synthesizes and releases dopamine

Cells of the exocrine pancreas produce digestive enzymes potentially harmful to the intestinal mucosa. Dopamine has been reported to protect against mucosal injury. In looking for the source of dopamine in the small intestine, we found that the duodenal juice contains high levels of dopamine and that the pancreas itself has a high dopamine [and dihydroxyphenylalanine (dopa)] content that does not change significantly after chemical sympathectomy. Furthermore, we were able to demonstrate tyrosine hydroxylase (TH) activity in control pancreas as well as in pancreas from rats after chemical sympathectomy. Immunostaining and in situ hybridization histochemistry confirmed both the presence of TH, dopamine, and the dopamine transporter, and the mRNAs encoding TH and dopamine transporter, and the presence of both types of vesicular monoamine transporters in the exocrine cells of the pancreas. Since there are no catecholaminergic enteric ganglia in the pancreas, the above results indicate that pancreatic cells have all the characteristics of dopamine-producing cells. We suggest that the pancreas is an important source of nonneuronal dopamine in the body, and that this dopamine has a role in protecting the intestinal mucosa and suggests that dopamine D1b receptor agonists might be used to help mucosal healing in the gastrointestinal tract.

Video cystometric recording of dilating reflux in infancy

PURPOSE

Bladder hypercontractility has previously been suggested to occur in male infants with gross bilateral reflux, and the causal relationship between hypercontractility and reflux has been questioned.

MATERIALS AND METHODS

In this video urodynamic study of dilating reflux the association between reflux and bladder pressure was evaluated in 16 infants.

RESULTS

In our 11 male patients hypercontractility was noted often, usually with reflux that occurred simultaneously with an increase in detrusor pressure. In the 5 female patients no hypercontractility was noted and reflux occurred without an increase in detrusor pressure.

CONCLUSIONS

Our results further confirm the association between bladder dysfunction and dilating reflux in infants but with different patterns in male and female infants.

Micturition habits and incontinence at age 17--reinvestigation ofa cohort studied at age 7

OBJECTIVE

To study the epidemiology of micturition disturbances in teenagers.

SUBJECTS AND METHODS

A subsample of 1034 teenagers previously evaluated at age 7 years was reinvestigated 10 years later. A postal questionnaire was used and a response rate of 71% (736) obtained. Those who reported bladder symptoms were contacted by telephone for a detailed history concerning imperative urge, daytime incontinence, emptying difficulties and bedwetting.

RESULTS

There was a general decrease in the frequency and intensity of symptoms from 7 to 17 years of age. At age 17 at least one symptom was reported by 5.9% of the girls and 0.9% of the boys. Overall the symptoms were regarded as mild or moderate.

CONCLUSION

At age 17 years, micturition disturbances were reported infrequently and few subjects wanted medical help.

Segmental median nerve conduction measurements discriminate carpal tunnel syndrome from diabetic polyneuropathy

Median nerve conduction has been compared in CTS, with or without diabetes, and diabetic polyneuropathy. Approximately 90% of hands were correctly predicted as CTS or diabetic polyneuropathy by a comparison including the median antidromic sensory nerve conduction velocities in the elbow-to-wrist segment, wrist-to-palm segment, palm-to-finger segment, and the amplitude of the sensory nerve action potential. CTS with diabetes could not be distinguished from CTS without diabetes. The association between proximal and distal nerve conduction velocities was similar in CTS and diabetic polyneuropathy. A study in motor fibers showed that the hands could be classified through a combination of M-wave latency and the more proximal motor nerve conduction velocity measurements. Independent of severity, motor and sensory nerve conduction was influenced to an equal degree in CTS and diabetic polyneuropathy. The hypothesis that both CTS and diabetic polyneuropathy can be associated with neural ischemia is discussed.

Median sensory nerve conduction block during wrist flexion in the carpal tunnel syndrome

A new method for diagnosing the carpal tunnel syndrome (CTS) is introduced. We have determined the time (T50) necessary to reach a 50% reduction in the amplitude of the median antidromic sensory nerve action potential during wrist flexion. Ten patients with anamnestic and neurophysiological evidence of CTS (group CTS) and 20 patients with CTS suspected on clinical grounds (group CTS?) were compared with 10 normal subjects. During wrist flexion the sensory conduction in the median nerve became partially blocked in all patients, and also in 8 out of 10 controls. The T50 value in 8 out of 10 CTS patients and in 14 out of 20 CTS? patients was below the lowest recorded value in the control group. It was shown that ischemia caused the blocking of the median nerve. Determination of T50 of the median nerve SNAP during wrist flexion has the potential to add to the sensitivity and specificity of the electrophysiological diagnosis of CTS.

An in vivo study of the effect of 5-HT and sympathetic nerves on transferrin and transthyretin mRNA expression in rat choroid plexus and meninges

Brain expression of transferrin (Tf) and transthyretin (TTR) mRNA has been demonstrated in different species, TTR being found only in the choroid plexus. We report here that both these mRNAs are also expressed in the meninges. In vitro studies have shown that Tf secretion by the rat choroid plexus is stimulated by 5-hydroxytryptamine (5-HT) while sympathetic nerves regulate different transport functions in the same tissue. We have used various in vivo models to study the neuroendocrine regulation of Tf and TTR mRNA expression in the choroid plexus and meninges. Destruction of the serotonergic nerves in the brain by either raphe nuclei lesion or intraventricular injections of 5,7-dihydroxytryptamine (5,7-DHT), which both decreased brain 5-HT levels significantly, did not affect Tf or TTR mRNA levels in choroid plexus and meninges, but increased TTR mRNA in liver. Intraventricular injection of 10 or 100 pmol 5-HT did not change the expression of these proteins in any of the tissues studied. Removal of the sympathetic innervation to the choroid plexus by cervical sympathectomy did not affect Tf or TTR mRNA levels in choroid plexus and liver, nor the incorporation of radioactive leucine into protein in various parts of the brain. In conclusion, our results do not support a regulatory role in vivo for neuronally derived 5-HT or sympathetic nerve activity on Tf and TTR mRNA expression in rat choroid plexus and meninges.

Reliability of ultrasonography in identification of reflux nephropathy in children

OBJECTIVE

To assess the ability of ultrasonography to identify reflux nephropathy in children after urinary tract infection.

DESIGN

Ten experienced radiologists performed a total of 240 ultrasonographic examinations of kidneys in a one day study. The examiners were unaware of the results of previous radiological and clinical examinations and of the proportions of normal and abnormal kidneys. Urography was used as method of reference, supported by static renal scintigraphy (dimercaptosuccinic acid labelled with technetium-99m) in half of the cases.

SETTING

Outpatient radiology department.

SUBJECTS

25 children aged 2-16 years (20 kidneys with and 30 kidneys without renal scarring).

MAIN OUTCOME MEASURES

Renal scarring. Overall size and length of kidneys. Sensitivity and specificity including receiver operator characteristics and variation between observers.

RESULTS

With renal scarring as the diagnostic criterion and including cases classified as abnormal, probably abnormal, and uncertain the sensitivity of ultrasonography was 54% (specificity 80%). Addition of reduced renal size as a diagnostic criterion increased the sensitivity to 64% (specificity 79%). There were, however, wide variations between observers, with sensitivity ranging between 40% and 90% (specificity 94% to 65%).

CONCLUSIONS

Because of its low sensitivity and specificity and poor agreement between observers, ultrasonography cannot be generally recommended for the detection of reflux nephropathy after urinary tract infection in children.

Does forearm mixed nerve conduction velocity reflect retrograde changes in carpal tunnel syndrome?

The mixed nerve conduction velocity of the median nerve in the forearm diverged from the motor and sensory nerve conduction velocities and correlated poorly with the severity of carpal tunnel syndrome (CTS) in 61 hands. In contrast, the motor and sensory nerve conduction velocities in the forearm correlated well with CTS severity. The mixed nerve conduction velocity in the forearm is probably determined by nonlesioned fibers such as those from the cutaneous palmar branch of the median nerve. The motor and sensory, but not the mixed nerve conduction velocities in the forearm may be used to estimate possible retrograde impairment in CTS.

Surgical treatment of carpal tunnel syndrome in patients exposed to vibration from handheld tools

During 1985 at Sabbatsberg Hospital in Stockholm, carpal tunnel decompression was done for 50 men (58 hands) with carpal tunnel syndrome (CTS). In 1988 2.5 to 3 years after the operations, a questionnaire about their present health was answered by 43 men (50 hands). In 10/17 (59%) hands exposed to vibrations and 26/33 (79%) not exposed, carpal tunnel decompression had resulted in no recurrence of neurological symptoms at follow up. Preoperative signs of neurophysiological dysfunction of the ulnar nerve, which might indicate a more widespread neuropathy, did not correlate with poor postoperative function of the median nerve. We recommend that patients with carpal tunnel syndrome should be operated on, whether or not they have been exposed to vibration.

Staphylococcus saprophyticus urinary tract infections in children

Staphylococcus saprophyticus commonly causes urinary tract infection (UTI) in young women; in males it is found mainly in the elderly. In this study S. saprophyticus UTI occurred in 59 children (45 girls and 14 boys) below 16 years of age, of whom 20 were less than 13 years of age. The common presentation was dysuria and flank or back pain whereas fever > or = 38.5 degrees C was rare. Radiological investigation performed in 63% of the children revealed no anomalies of importance. Children with S. saprophyticus UTI appear to constitute a group with a low frequency of urinary tract anomalies and with a low risk of UTI caused by other bacteria.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.