Infants with congenital limb reduction registered in the Swedish Register of Congenital Malformations

Limb reduction defects reported to the Swedish Register of Congenital Malformations 1965-1979 have been analyzed from a monitoring point of view. The infants were first studied with respect to the site of reduction malformation and the simultaneous presence of more than one such reduction site. Reductions often occurring together were thought to have a common pathogenesis (etiology) and were therefore treated as one unity although some such groups (e.g., radial longitudinal reductions) are probably heterogeneous. The material was therefore divided into 11 subgroups; the eleventh is represented by infants with more than one unrelated reduction. Maternal age distribution was approximately normal. There is a male preponderance of all reduction types. In the whole group, 20% of the infants died perinatally, but this percentage was higher for some groups (e.g., amelia/phocomelia) than for others (e.g., amputations and unspecific hand/foot reductions). In more than 30% of the infants, nonlimb malformations were also present. Such infants showed the highest death rate of all. The infants had a lower than expected birth weight (gestational length was not known). The time trends for the various subgroups differed. Amelia/phocomelia declined in frequency but the unspecific hand/foot reductions showed a marked increase during the last few years, possibly owing to better ascertainment. The significance of monitoring reduction malformations as smaller subgroups is stressed, as marked changes may occur within a subgroup without a noticeable change in the total number of reductions.

P-fimbriae, bacterial adhesion, and pyelonephritis

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Receptors for pyelonephritogenic Escherichia coli in primates

P-fimbriated Escherichia coli adhere to uroepithelial cells of monkeys by binding to receptors which are identical or very similar to those of man. In atraumatic experimental infections of monkeys, a P-fimbriated Escherichia coli strain induced ureteral malfunction with subsequent pyelonephritis. A non-P-fimbriated Escherichia coli strain did not. Thus, P-fimbriation of Escherichia coli represents a true virulence factor in the acquisition of pyelonephritis.

P-fimbriae of pyelonephritogenic Escherichia coli: detection in clinical material by a rapid receptor-specific agglutination test

A slide agglutination test to detect P-fimbriated Escherichia coli was developed by attaching glycosides containing the relevant receptor structure (alpha-D-Galp-(1-4)-beta-D-Galp) to particles. A suspension of these particles agglutinates within ten seconds when mixed with P-fimbriated bacteria. The test is named the P-specific particle agglutination test (PPA test). The PPA test is more sensitive than the haemagglutination assays previously used. The exclusive specificity of the PPA test also allows the detection of P-fimbriae on strains which additionally possess other fimbriae (e.g. X-fimbriae). Using this test, the frequency of P-fimbriated E. coli in children with acute non-obstructive pyelonephritis was shown to exceed 95%. In lower urinary tract infections the frequency of P-fimbriated E. coli was approximately 20%. Moreover, children with acute pyelonephritis were also found to be heavily colonized in both the periurethral area and the intestine with the identical P-fimbriated E. coli strain.

P-fimbriae of pyelonephritogenic Escherichia coli: significance for reflux and renal scarring-a hypothesis

An experimental pyelonephritis model was developed in monkeys (Macaca fascicularis) using P-fimbriated Escherichia coli as the infecting organism. The relevant receptor molecules for P-fimbriae were also shown to be present in Macaca fascicularis. Atraumatic administration of P-fimbriated E. coli into the ureter induced a ureteritis followed by acute and chronic pyelonephritis. The decisive role of P-fimbriae as an adhesive virulence factor was proven by the receptor blockade of P-fimbriae-mediated bacterial adhesion by a synthetic receptor analogue (alpha-D-Galp-(1-4)-beta-D-Galp-1-OMe), which was administered into the ureter together with the challenge bacteria. On the basis of these and other findings, the role of reflux and pyelonephritis in relation to renal scarring is discussed in this paper. It is proposed that minor transitional vesicoureteral reflux together with the adhesive property of P-fimbriated E. coli and their ability to induce ureteritis might constitute an alternative mechanism to gross reflux by which bacteria ascend to the kidney. These findings and the fact that intestinal colonization with P-fimbriated E. coli coincides with the disease have opened up new prophylactic and therapeutic possibilities.

P-fimbriae of pyelonephritogenic Escherichia coli: identification and chemical characterization of receptors

Pyelonephritogenic Escherichia coli isolates were found to be equal in their ability to adhere to uroepithelial cells and to cause agglutination specific for human erythrocytes. This adhesive capacity was not affected by D-mannose and was found to be mediated by a new class of E. coli fimbriae named P-fimbriae. Using human erythrocytes of different blood groups, we found the receptor molecules for P-fimbriae to be associated with the P blood group antigens, i. e. glycosphingolipids corresponding to the P blood group antigens P, P1 and Pk. By agglutination studies of erythrocytes with various set-ups of these antigens as well as by inhibition studies using synthetic saccharide derivatives and by coating non-agglutinable erythrocytes with a synthetic glycolipid, the minimal receptor structure was identified as the alpha-D-Galp-(1-4)-beta-D-Galp moiety of the carbohydrate portion of these glycosphingolipids. Similar experiments on isolated uroepithelial cells proved that these glycosphingolipids also constitute the receptors in the urinary tract.

Rapid identification of P-fimbriated Escherichia coli by a receptor-specific particle agglutination test

Most (greater than 90%) Escherichia coli strains isolated from children with acute non-obstructive pyelonephritis exhibit a specific type of filamentous protein appendage known as P-fimbriae. These fimbriae enable the bacterium to adhere to human uroepithelial cells by the specific recognition of and binding to a particular class of glycosphingolipids correlated to the human P-blood group antigens. In this paper a new method for the rapid and reliable identification of such P-fimbriated pyelonephritogenic bacteria is described. The method is based on particles to which the minimal glycoside receptor structure recognized by P-fimbriae is attached. Mixing these receptor-containing particles with P-fimbriated bacteria results in a strong and immediate agglutination reaction. The specificity and sensitivity of this new particle agglutination test proved to be superior to the haemagglutination assay previously used.

Immunoreactive calcitonin in maternal milk and serum in relation to prolactin and neurotensin

Maternal milk four days post partum contained immunoreactive calcitonin in concentrations which were 22-89 times higher than those noted in concomitantly sampled maternal sera. Neurotensin-like immunoreactivity was barely detectable in milk. It is suggested that calcitonin may be a prerequisite for the concentration of calcium ions in milk but there is also possibility that it acts locally on the intestinal mucosa.

Occurrence of P-fimbriated Escherichia coli in urinary tract infections

The occurrence of Escherichia coli possessing P blood-group-specific adhesins (P-fimbriae) was examined in 97 children with urinary tract infections and 82 healthy controls. P-fimbriae were present in 91% (33/35) of the urinary strains causing acute pyelonephritis. Among strains causing cystitis and asymptomatic bacteriuria P-fimbriae were found in 19% and 14% of cases, respectively. Only 7% of faecal isolates from healthy controls carried P-fimbriae. The results were similar in three different studies. In most of the children with acute pyelonephritis the urinary pathogen was the predominant E. coli strain of the periurethral and faecal flora.

Compensatory kidney growth in children with urinary tract infection and unilateral renal scarring: an epidemiologic study

Compensatory renal growth was estimated from repeated urograms over 8 to 15 years in 26 children with urinary tract infection and unilateral renal scarring. These children were derived from an unselected series of 596 patients followed from their first symptomatic urinary tract infection. Renal size was assessed from the renal area, length, and parenchymal thickness. The renal area proved to be a good measure of the compensatory growth of the unscarred kidney as well as of the loss of substance of the scarred kidney. In this series of children, who had been closely supervised from the time of their first infection, unilateral renal scarring was well compensated for by hypertrophy of the contralateral kidney. Thus, the total renal parenchymal area 8 to 15 years after the first investigation was 98 to 99% of the expected normal area. Interestingly, a conspicuous growth spurt was observed at puberty in some of the scarred kidneys, sometimes a decade after the original damage. Prognosis was not influenced by sex, age at onset, or complications such as vesicoureteric reflux and frequent febrile recurrences. Reflux with dilatation was compatible with compensatory renal growth. We conclude that acute febrile pyelonephritis in childhood carries a good prognosis with regard to preservation of renal parenchyma and level of GFR, if diagnosis and treatment are prompt and long-term supervision is provided.

Structure of carbohydrate part of receptor on human uroepithelial cells for pyelonephritogenic Escherichia coli

The binding of pyelonephritogenic Escherichia coli strains to human uroepithelial cells from patients with and without P blood group antigens was investigated. Uroepithelial cells from p phenotypes bound pyelonephritogenic e. coli to a significantly lesser extent than did cells from P1 and P2 phenotypes. The binding of pyelonephritogenic E. coli to urinary epithelial cells of P1 phenotypes was blocked by the synthetic disaccharide alpha-D-Galp-(1 leads to 4)-beta-D-Galp whose structures is related to that of the P blood group antigens. Coating of P1 cells with a synthetic disaccharide derivative increased the binding of bacteria. None of 30 individuals of p phenotype had had urinary tract infection. The findings show that the disaccharide alpha-D-Galp-(1 leads to 4)-beta-D-Galp, previously shown to be the erythrocyte receptor for the fimbriae of pyelonephritongenic E. coli, is also the receptor structure on uroepithelial cells.

Catecholamine and cortisol excretion patterns in three-year-old children and their parents

Urinary catecholamine and cortisol excretion was studied in a group of three-year-olds, their mothers and fathers during night rest, one day at home and one day at hospital. The stay in the hospital, which was part of a longitudinal study of the families, induced a pronounced rise in adrenaline excretion and a moderate increase in noradrenaline excretion in relation to the at-home level. Although the catecholamine excretion in relation to body weight was much higher in the children, the magnitude of the increase at the hospital was about the same in all the family members. The adrenaline excretion was also affected by the diverse conditions at the hospital and showed, for example, a marked decrease during lunch hour. The cortisol excretion at the hospital tended to be elevated only in fathers. On the average, mothers excreted about the same amount of adrenaline as the fathers at the hospital, but significantly more noradrenaline. In earlier studies males have shown a greater adrenaline output than females during achievement-demanding situations. The findings of this study were interpreted within the context of the specific challenge that the situation represented to the mothers. The mothers also excreted more noradrenaline in the at-home condition. Catecholamine and cortisol excretion levels within family members tended to be positively correlated, but the correlations were generally low.

Early detection of nephropathy in childhood urinary tract infection

Early detection and treatment of nephropathy in childhood urinary tract infection is important for the planning of treatment and supervision. In patients without abnormalities of calyces or defects of kidney outline standardized measurements of the thickness of the parenchyma at three sites on each kidney are more informative in establishing early affection of the kidney than other measurable parameters available. The majority of patients who will develop focal renal scarring can be identified early after their first symptomatic infection from measurement of the appropriate dimensions of the parenchyma.

Chronic renal failure in Swedish children

In a retrospective study covering the years 1974 to 1977 the prevalence of non-terminal renal failure in Swedish children on to 15 years of age was registered as 4.50 per million total population. The mean yearly incidence of terminal renal failure during the same period was registered as 0.94 per million total population. Nephronophthisis was the most common single cause of renal failure. No case of coarse renal scarring due to recurrent urinary tract infections was reported. The Swedish study shows a good agreement with an earlier Swiss one concerning the diseases causing chronic renal failure in children. The frequency of chronic renal failure is expected to be essentially unchanged until breakthroughs occur in research on glomerulonephritis.

In vitro adhesion of uropathogenic Escherichia coli to human periurethral cells

The in vitro adhesion of three uropathogenic strains of Escherichia coli to epithelial cells from the periurethral area (area surrounding the urethral orifice) of women with and without a history of recurrent urinary tract infections was investigated. All strains showed a specific mannose-resistant hemagglutination restricted to human erythrocytes. Since only a few hundred periurethral cells were used in each test, gentle methods were required. Optimal results were obtained with bacteria grown for 16 h at 37 degrees C in nutrient broth without shaking. The binding of bacteria seemed to be irreversible under the conditions studied, since repeated washings of the epithelial cells after incubation did not decrease the number of adhering bacteria. Chloramphenicol was used to control the number of added bacteria in the incubation system. A difference in the adhesive capacity of periurethral cells of infection-prone and healthy individuals was most evident at concentrations of 2.5 x 10(9) bacteria/ml. Electron microscope studies indicated that pili mediated the adhesion. Adhesion was correlated with the mannose-resistant hemagglutination of human erythrocytes, indicating that the pili were not type 1 pili. Day-to-day variations in the adhesiveness of the bacteria were reduced by selecting well-adhering bacteria with the aid of in vitro passage on periurethral cells or human erythrocytes, and by exclusion of bacteria with low hemagglutination ability.

Identification of a carbohydrate receptor recognized by uropathogenic Escherichia coli

Earlier investigations have shown that pyelonephritic Escherichia coli specifically recognize and bind to carbohydrate structures correlated to the P blood group antigens. These findings are confirmed and extended in this study. Twenty-two of 23 nonselected E. coli strains from children with acute febrile pyelonephritis failed to agglutinate human erythrocytes lacking the antigens within the P blood group system. Only one of 32 faecal isolates exhibited this specific agglutinating property. The new informatin in this paper is that P2k erythrocytes, containing only the Pk antigen, were agglutinated to the same extent by pyelonephritic E. coli strains, giving further support to the proposal that the Pk glycosphingolipid is related to the receptor for pyelonephritic E. coli. In addition, the importance of the oligosaccharide moiety of the Pk glycosphingolipid for the binding of E. coli was further investigated. The synthesized disaccharide alpha-D-Galp-(1-4)-beta-D-Galp-1-O-0-NO2 inhibited the agglutination of human erythrocytes caused by two pyelonephritic E. coli strains at concentrations of less than 1 mM. Hence, the minimal receptor structure recognized by these E. coli strains appears to be the alpha-D-Galp-(1-4)-beta-D-Galp structure. How generally valid this observation may be needs further investigation. The findings may open new possibilities for diagnosis and treatment of urinary tract infection.

Periurethral anaerobic microflora of healthy girls

The periurethral anaerobic and aerobic microfloras were investigated in 18 healthy premenarcheal girls, 5 to 14 years of age, by using a quantitative sampling method. Colonization of the female periurethral area with enterobacteria seems to be an important step in the development of urinary tract infections, and the present study was undertaken as a stage in elucidating factors that might control the establishment of urinary tract pathogens periurethrally. The study showed that obligate anaerobic bacteria constituted 95.0% (standard error, +/- 5.8%) of the total colony-forming units per square centimeter of periurethral area. An average of 7.0 different anaerobic and 2.7 different aerobic strains per specimen was obtained. The flora was dominated by anaerobic gram-positive cocci and gram-positive rods, whereas anaerobic gram-negative rods comprised a minor part. The most commonly encountered anaerobic isolates were peptococci and peptostreptococci, propionibacteria, bifidobacteria, eubacteria, and bacteroides in decreasing order of frequency. The aerobic flora consisted most commonly of nonhemolytic streptococci and diphtheroids. The findings suggest that the periurethral microenvironment is a distinctive ecological niche, separate from the fecal and skin biotas, although it has some characteristics in common with the vaginal flora.

Dealing with suspicions of malformation frequency increase. Experience with the Swedish register of congenital malformations

Strategies in dealing with data obtained from malformation monitoring based on experiences with the Swedish monitoring systems, operating since 1965 (Register of Congenital Malformations) and 1973 (Medical Birth Register) are discussed. The importance of checking data that have sounded an alarm is stressed. Experience has shown that false alarms due to artefacts, such as changed diagnostic routines, changed reporting or registration of malformations, or random fluctuations, comprise most suspected changes in incidence. If a true increase in malformation frequency or a local cluster is observed, a hint of possible aetiological factors can be obtained from studies of maternal age distribution, seasonal viriation, geographical distribution, etc. The last step of the analysis consists of a case-control or a cohort study, aimed at revealing a specific teratogen. The importance of locating limited research resources to well-defined problems using high quality data is stressed.