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Biomedical subjects

J Winberg

Publications and source records attributed to J Winberg.

At least 37 records · Page 2Linked to original sources
PubMed1996

Attractiveness of amniotic fluid odor: evidence of prenatal olfactory learning?

Human infants are responsive to maternal odors beginning shortly after birth. In several non-human mammals, the fetus is capable of olfactory learning and in some species neonates are attracted to the odor of amniotic fluid (AF). The present study examined the responses of newborn babies to AF in a biologically relevant context, i.e. during their initial attempt to locate the mother's nipple/areola. We observed newborns' spontaneous choice between a breast with the nipple/areola moistened with AF and an untreated breast; 23 of 30 infants chose the AF-treated breast. All babies had been washed before the observations, and only 12/30 sucked their hands/fingers prior to approaching the nipple/ areola. In a previous study with unwashed newborns, the corresponding proportion was 27/30 (p < 0.001). We tentatively suggest that the observed attraction to AF odor may reflect fetal exposure to that substance (i.e. prenatal olfactory learning). Because of the salience of biological odors for neonates, products that eliminate or mask such cues should be avoided during the perinatal period.

Amniotic Fluid↗
PubMed1995

The PapG-adhesin at the tip of P-fimbriae provides Escherichia coli with a competitive edge in experimental bladder infections of cynomolgus monkeys.

Human urinary tract infection is an infectious disease that depends on a series of host-microbial interactions. The bacteria first colonize the colon and then the periurethral/vaginal areas; they ascend to and infect first the bladder and then the kidneys. Expression of Escherichia coli P-fimbriae constitutes the strongest correlation to renal pathogenicity, but is also related to first-time cystitis in children. The role of P-fimbriae in the preceding steps in the infectious process is unknown. To examine this, we constructed, from a P-fimbriated E. coli strain with a class II G-adhesin preferentially binding to globoside, one isogenic mutant lacking the G-adhesin and another isogenic mutant in which we replaced the papG class II allele with a class III adhesin preferentially binding to the Forssman antigen. We report here the comparison of the adhesin knockout mutant (DS17-8) and the class-switch mutant (DS17-1) with the wild-type (DS17) for in vivo colonization of the gut, vagina, and bladder of cynomolgus monkeys. It was recently shown that the class II tip G-adhesin is a prerequisite for acute pyelonephritis to occur in the monkey model in the absence of other kidney-specific adhesins or obstruction of the urinary flow. Here we show that it is not required for bladder infection but gives a competitive advantage in mixed infections. In the vagina and colon, the G-adhesin gives no competitive advantage.

Adhesins, Escherichia coli↗
PubMed1995

Separation distress call in the human neonate in the absence of maternal body contact.

Few studies have used the baby's cry as a means of evaluating the quality of neonatal care. In this randomized trial the newborn's cry was registered during the first 90 min after birth when infants were cared for either: (a) skin-to-skin with the mother; (b) in a cot; or (c) in a cot for the first 45 min of the 90-min observation period and then skin-to-skin with the mother. The results suggested that human infants recognize physical separation from their mothers and start to cry in pulses. Crying stops at reunion. The observed postnatal cry may be a human counterpart to the "separation distress call" which is a general phenomenon among several mammalian species, and serves to restore proximity to the mother. Our results suggest that in human newborns this cry is not dependent on earlier social experience and may be a genetically encoded reaction to separation. The findings are compatible with the opinion that the most appropriate position of the healthy full-term newborn baby after birth is in close body contact with the mother.

Crying↗
PubMed1994

The Gal(alpha 1-4)Gal-specific tip adhesin of Escherichia coli P-fimbriae is needed for pyelonephritis to occur in the normal urinary tract.

Nonobstructive acute pyelonephritis in humans is most often caused by P-fimbriated Escherichia coli. P-fimbriae are heteropolymeric fibers carrying a Gal(alpha 1-4)Gal-specific PapG adhesin at its distal end. The pyelonephritic strain DS17 expresses P-fimbriae from a single gene cluster. A mutant strain, DS17-8, which expresses P-fimbriae tacking the PapG adhesin, was constructed by allelic replacement introducing a 1-bp deletion early in the papG gene. In cynomolgus monkeys, DS17 and DS17-8 were equally able to cause bladder infection, whereas only the wild-type strain DS17 could cause pyelonephritis as monitored by bacteriological, functional, and histopathological criteria. Since DS17, but not DS17-8, adheres to renal tissue, these data underscore the critical role of microbial adherence to host tissues in infectious disease and strongly suggest that the PapG tip adhesin of P-fimbriae is essential in the pathogenesis of human kidney infection.

Adhesins, Escherichia coli↗
PubMed1994

Does the newborn baby find the nipple by smell?

We studied the involvement of naturally occurring odours in guiding the baby to the nipple. One breast of each participating mother was washed immediately after delivery. The newborn infant was placed prone between the breasts. Of 30 infants, 22 spontaneously selected the unwashed breast. The washing procedure had no effect on breast temperature. We concluded that the infants responded to olfactory differences between the washed and unwashed breasts.

Breast Feeding↗
PubMed1994

Management of primary vesico-ureteric reflux in children--operation ineffective in preventing progressive renal damage.

Four studies comprising 606 children and with a follow-up of 4-5 years have shown that operation and long-term antibiotic prophylaxis are equally ineffective in preventing post-infectious, progressive renal damage in children with grade III-IV reflux. To consider only the grade of reflux in the choice of management is too simple an approach. Other aspects of the complex biology of UTI should also be considered. Another important aspect concerns the organization of the care. Efficient and robust routines for a thorough follow-up and measures to guarantee immediate diagnosis and treatment of recurrent infections in children known to be at risk may be more important for the preservation of the kidneys than a stereotyped policy of operation or "endless" antibiotic prophylaxis. Specialized teams should be used as in the treatment of other long-term diseases. Parents should be educated and made active participants in the supervision of children at risk. Controlled multicentre studies are powerful scientific instruments, but appear to have too little impact on clinical practice. The responsibility of clinical scientists to make important results known and understood among those concerned is discussed from the ethical point of view.

Anti-Bacterial Agents↗
PubMed1993

Pathogenesis of urinary tract infection--experimental studies of vaginal resistance to colonization.

The review summarizes studies of vaginal colonization resistance against Escherichia coli in a primate model. The genital flora surrounding the urethral orifice exerts a strong colonization resistance. Amoxicillin profoundly disturbs the normal vaginal microflora, reduces its adherence to vaginal epithelial cells in vivo and promotes a persistent vaginal E. coli colonization. Certain cephalosporins may have a similar effect. The induced ecological changes mimic those seen in patients with recurrent urinary tract infections (UTI). Amoxicillin also promotes the spread of E. coli from rectum to vagina, which may be of clinical significance. Trimethoprim and nitrofurantoin do not have these effects. The natural colonization resistance could not clearly be correlated with the presence of lactobacilli, which were only transiently reduced by amoxicillin. The colonization resistance against E. coli could only partly be restored by vaginal instillation of lactobacilli, but was fully restored by flushing of the whole vaginal flora from a healthy monkey. Clinical observations suggest that accumulation of E. coli around the urethral orifice increases the risk of UTI. We conclude that antibiotics and other compounds that interfere with the normal genital flora may increase the risk of UTI. This should influence the choice of antibiotics in the treatment of UTI.

Animals↗
PubMed1993

Lower body temperatures in infants delivered by caesarean section than in vaginally delivered infants.

Clinical experience suggests that infants delivered by caesarean section have difficulties maintaining normal body temperature during the first hours after birth. To test this hypothesis, body and skin temperatures were measured and compared in healthy full-term caesarean section and vaginally delivered newborn infants. The babies were studied during the first 90 min after birth. Axillary and skin temperatures were significantly higher in the vaginally delivered group than in infants delivered by caesarean section. Infants born by non-elective caesarean section were slightly warmer during the first 90 min after birth compared to infants born by elective caesarean section. There were no significant differences in temperatures between infants cared for in a cot as compared to those cared for in an incubator. An incubator creates a physical barrier between babies and parents and incubator care might cause parental anxiety. Thus the routine of putting healthy, full-term caesarean section infants in incubators can be abandoned from a thermoregulatory point of view.

Axilla↗
PubMed1993

Plasma cholecystokinin concentrations after breast feeding in healthy 4 day old infants.

The aim of the present study was to characterise plasma concentrations of cholecystokinin (CCK) after breast feeding in newborn infants. Fifty eight healthy full term exclusively breast fed infants were investigated at 4 (1) (2-6) days of age. Each infant contributed one blood sample collected just before, immediately after, or 10, 30, and 60 minutes after breast feeding. Plasma concentrations of CCK were measured with a technique consisting of high pressure liquid chromatography separation of gastrins and CCKs and consequent analysis with radioimmunoassay. Mean (SD) preprandial plasma concentrations of CCK (CCK8+CCK-33,39) were 68 (17) pmol/l. A significant increase was seen immediately after breast feeding, which was followed by a decline at 10 minutes and a secondary rise was seen at 30 and 60 minutes. The first peak is likely to be due to a suckling related activation of the vagal nerve and the second to a stimulatory effect of food on CCK-producing cells. An inverse relationship between basal concentrations of CCK and age of the infant was found. In rats peripheral injections of CCK reduce food intake and cause postprandial sedation and sleepiness via activation of an afferent vagal mechanism. CCK release in response to breast feeding may therefore in addition to exerting stimulatory effects on digestion and metabolism contribute to relaxation and sleepiness seen after breast feeding. The high CCK concentrations seen in younger infants may help the infant to remain satiated and calm despite receiving very little food during the first days of life.

Birth Weight↗
PubMed1992

Long-term prognosis of post-infectious renal scarring in relation to radiological findings in childhood--a 27-year follow-up.

In a previous report the long-term prognosis of 30 patients with renal scarring after pyelonephritis in childhood was described. In this study, we have related the extent of renal scarring present in childhood to the conditions in early adulthood. A radiological progression of scarring from childhood to adulthood was seen in one-third of the kidneys. The 7 patients with bilateral scarring in childhood had a smaller renal area, lower glomerular filtration rate and higher plasma vasopressin at follow-up than 13 healthy controls. The 20 patients who had unilateral scarring in childhood had a smaller renal area, lower glomerular filtration rate, higher diastolic blood pressure and higher plasma renin at follow-up than controls; 4 had hypertension. The most important finding was that children with unilateral disease are at risk of serious long-term complications. Filtration fraction at follow-up was higher in patients with extensive renal scarring in childhood compared with those with a normal renal area or small scars in childhood (r = -0.43, P less than 0.05). This may indicate glomerular hyperfiltration by remnant glomeruli. This paper emphasizes t the potential seriousness of childhood urinary tract infections especially when early infantile infections are overlooked. A follow-up of more than 4 decades may be necessary before the ultimate prognosis can be established, especially in patients with unilateral renal disease. It is advised that most patients with post-infectious renal scars are followed as high-risk patients, and that treatment continuity is established between paediatricians, nephrologists and, when required, obstetricians.

Adolescent↗
PubMed1992

The effect of amoxycillin on vaginal colonization resistance and normal vaginal flora in monkeys.

Previous studies have shown that vaginal colonization resistance in monkeys can be eliminated by amoxycillin and restored by flushing vaginal flora from a healthy monkey into the vagina of a monkey colonized with Escherichia coli. The hypothesis that the effect of amoxycillin resulted from elimination of parts of the normal flora was tested in the present study. Nine monkeys were flushed vaginally with amoxycillin daily for six days. The number of anaerobic bacteria decreased during amoxycillin administration, as did the number of species isolated. The most obvious effects were observed among the genera Bacteroides and Peptostreptococcus, while Lactobacillus spp. were less affected. Restoration of the flora after amoxycillin administration was slow in most of the monkeys. During amoxycillin administration, all monkeys became colonized spontaneously with E. coli. This was not, however, associated with increased adherence in vitro. The colonization persisted throughout the study period (29 days). It was concluded that amoxycillin disturbs vaginal colonization resistance by eliminating at least part of the normal vaginal flora, thereby promoting periurethral colonization with enterobacteria.

Amoxicillin↗