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Biomedical subjects

T Lindberg

Publications and source records attributed to T Lindberg.

At least 19 recordsLinked to original sources

Genetic characterization and antibiotic resistance of Campylobacter jejuni isolated from meats, water, and humans in Sweden.

The incidence of Campylobacter jejuni has increased during the last decade, and today it is the leading cause of bacterial enteritis in most developed countries. Still, there is a lack of knowledge about infection routes and to what extent identified sources are responsible for spreading the bacterium to humans. The major objective of this work was to explore the genetic similarity between C. jejuni isolated from different sources. C. jejuni isolated from patients (n = 95), five types of meat (n = 71), and raw water (n = 11) during the year 2000 were subtyped by pulsed-field gel electrophoresis (PFGE). The pulsotypes obtained after digestion with SmaI revealed not only that C. jejuni is genetically diverse but also that specific pulsotypes occur frequently. Five clusters comprising 88 of the 162 SmaI-digested isolates were obtained. After digestion with KpnI most isolates in four of the five clusters were still indistinguishable, while the fifth cluster was strongly dissolved. The clusters comprised high frequencies of human and meat isolates, while only one of nine water isolates belonged to a cluster. The largest cluster comprised 21 human isolates, one raw water isolate, and seven chicken meat isolates, originating from at least six different broiler flocks. Low frequencies of antibiotic resistance were revealed when the meat and water isolates were tested for sensitivity to six antibiotics. Interestingly, the five isolates resistant to quinolones displayed similar or identical pulsotypes. The results showed that PFGE has proved useful in identifying clones and will be used in future work focusing on identification and eradication of the major reservoirs for common clones.

Animals↗

Epidemic of coeliac disease in Swedish children.

Coeliac disease has emerged as a public health problem. The aim of the present study was to analyse trends in the occurrence of symptomatic coeliac disease in Swedish children from 1973 to 1997, and to explore any temporal relationship to changes in infant dietary patterns. We established a population-based prospective incidence register of coeliac disease in 1991, and, in addition, retrospective data from 1973 were collected. A total of 2151 cases fulfilled the diagnostic criteria. Furthermore. We collected national data on a yearly basis on duration of breastfeeding, intake of gluten-containing cereals and recommendations on when and how to introduce gluten into the diet of infants. From 1985 to 1987 the annual incidence rate in children below 2 y of age increased fourfold to 200-240 cases per 100000 person years, followed from 1995 by a sharp decline to the previous level of 50-60 cases per 100000 person years. This epidemic pattern is quite unique for a chronic disease of immunological pathogenesis, suggesting that prevention could be possible. The ecological observations made in this study are compatible with the epidemic being the result, at least in part, of a change in and an interplay among three factors within the area of infant feeding, i.e. amount of gluten given, age at introduction of gluten, and whether breastfeeding was ongoing or not when gluten was introduced. Other factor(s) may also have contributed, and the search for these should be intensified.

Adolescent↗

First week kangaroo care in sick very preterm infants.

The aim was to investigate whether kangaroo care (KC) with and without nasogastric tube feeding (NG) is tolerated by sick preterm infants during the first week of life. Seventeen infants with current or resolving illness received 1 h of KC. The study patients were originally recruited for a study on the response of intestinal peptides to feeding during KC. Median gestational age was 28 wk and median birthweight 1238 g. During KC, eight infants received NG. During KC, oxygen requirements were unchanged or decreased in 15 infants and increased in 2 infants. Changes in arterial blood gases, transcutaneous pO2/pCO2, heart rate and temperature were minimal. One episode of apnoea occurred. In conclusion, KC was well tolerated, as was NG, during KC.

Enteral Nutrition↗

Infantile colic and small intestinal function: a nutritional problem?

Approximately 25% of infants with moderate or severe colic (crying > 3 h d(-1)) have a cow's milk-dependent colic. The author recommends a strict cow's milk-free diet for the mother (with an extra supplement of calcium) in breastfed infants and a casein-hydrolysate formula for formula-fed infants. With this dietary regimen, there will be no nutritional problems. Later in infancy a relatively high proportion of the infants will continue to show an adverse reaction to cow's milk and will also develop allergies to other foods. Several signs (e.g. increased macromolecular absorption, increased motilin levels in serum, increased breath hydrogen excretion, decreased gallbladder contractility) indicate an abnormal intestinal function in colicky infants. The nature of this abnormality is still unknown.

Animals↗

[Proposed criteria for diagnosis of celiac disease in children].

At a seminar arranged in September 1997 by the Swedish Paediatric Working Group for Coeliac Disease, a diagnostic protocol proposed by the working group was approved by a majority of the paediatricians present, representing almost all paediatric units in Sweden. Briefly, a small bowel biopsy is called for in all children, both at presentation and as a control during gluten-free dieting. Subsequent gluten challenge and biopsy are mandatory only in cases of atypical presentation or if the diagnosis is questioned at some future date. Serum antigliadin and anti-endomysial antibody tests are complementary tools. Agreement was also reached regarding the institution of a national coeliac disease registry.

Antibodies↗

In vitro digestion of proteins in human milk fortifiers and in preterm formula.

BACKGROUND: Knowledge about the digestibility of the proteins in new products designed for feeding preterm infants is limited. The purpose of this study was to observe in vitro the hydrolysis of the bovine and human whey proteins in such products. METHODS: Proteins in human milk, in human milk fortifiers (Presemp [Semper AB, Stockholm, Sweden] and Enfamil [Mead Johnson, Evansville, IN, U.S.A.] human milk fortifiers), in preterm formulas (Similac Special Care [Ross, Columbus, OH, U.S.A.] and Enfalac [Mead Johnson]), and whey protein concentrates with varying degrees of denaturation were digested by duodenal juice from healthy preterm infants, from a 3-year-old child, and from adults. Digestion was studied in vitro using polyacrylamide gradient gel electrophoresis, electroimmunoassay, and nonprotein nitrogen analysis. RESULTS: Casein was the protein most rapidly degraded in all products. Human and bovine whey proteins were more slowly digested; as much as 68% of human lactoferrin was still immunoreactive after 40 minutes of digestion. The corresponding figure for bovine serum albumin was 24-69%; for B-lactoglobulin, 20-40%; for bovine alpha-lactalbumin, 20-51%; and for human alpha-lactalbumin, 41%. Contrary to common belief, digestibility of bovine whey proteins decreased with a high degree of denaturation of the proteins. CONCLUSIONS: Bovine whey proteins in human milk fortifiers and in preterm formulas are relatively slowly digested in vitro by normal duodenal juice. The results may have implications for the design of products for feeding preterm infants.

Adult↗

Plasma somatostatin and cholecystokinin levels in response to feeding in preterm infants.

BACKGROUND: The functions of the gut are modulated by the autonomic nervous system and gut peptides, such as somatostatin and cholecystokinin, which have opposite functions. This study reports plasma somatostatin and cholecystokinin levels in response to feeding in preterm infants. METHODS: In 76 infants--gestational age 23 to 36 weeks, birth weight 460 to 2867 g--blood samples were taken on day 1 before the first meal in life, and 30 minutes after the end of the meal. Samples were again taken on days 3 and 4. The infants were fed human milk by nasogastric tube, by breast, or by bottle. In 10 additional infants, (gestational age 27-36 weeks) who were studied at a median postnatal age of 15 days, the response of the peptides to breast-feeding was compared with that of tube-feeding. Plasma somatostatin and cholecystokinin were analyzed by specific radioimmunoassays. RESULTS: On day 1, the median plasma somatostatin level increased after feeding in small-for-gestational-age infants but not in appropriate-for-gestational-age infants. On days 3 and 4, the somatostatin level decreased in infants with a gestational age of 32 weeks or more. On day 1, plasma cholecystokinin levels increased in infants with a gestational age of 32 weeks or more: The response was more pronounced in small-for-gestational-age infants. On days 3 and 4, plasma cholecystokinin levels increased only in breast-feeding infants. In the 10 infants fed by breast and by tube, plasma cholecystokinin levels increased after breast-feeding and tended to increase after tube-feeding. The plasma somatostatin levels were unaffected after feeding. CONCLUSIONS: Plasma somatostatin and cholecystokinin increased after feeding in small-for-gestational-age infants on day 1. On days 3 and 4, the responses to feeding seemed to be dependent on the infant's gestational age. Breast-feeding enhanced the release of cholecystokinin but not that of somatostatin.

Breast Feeding↗

Digestion of proteins in human milk, human milk fortifier, and preterm formula in infant rhesus monkeys.

BACKGROUND: There is limited information in the literature on the capacity of the preterm infant to digest human and bovine milk proteins. We therefore studied in vivo the luminal phase of the hydrolysis of proteins in human milk, human milk fortifier, and preterm formula in preterm rhesus monkeys and in infant rhesus monkeys at 6 weeks and 7 months of age. METHODS: Protein hydrolysis was followed by polyacrylamide gradient gel electrophoresis and electroimmunoassay. The serum level of absorbed unhydrolyzed human alpha-lactalbumin was measured by a radioimmunoassay method. Trypsin and elastase activities in duodenal contents were measured before and after the meal. RESULTS: In 6-week-old monkeys, the enzyme activities decreased by 50% postprandially, whereas they increased in 7-month-old monkeys. In preterm and in 6-week-old monkeys, hydrolysis of human and bovine whey proteins was slow, and in 6-week-old monkeys, 30-50% of the proteins could still be detected immunochemically in duodenal contents after 60 min. At these ages, serum level of absorbed alpha-lactalbumin were high. At 7 months of age, no or small (lactoferrin and bovine serum albumin) amounts of the proteins could be detected in duodenal contents after 15 min. At this age alpha-lactalbumin was not measurable in serum. CONCLUSIONS: The low capacity to digest whey proteins in suckling monkeys may depend upon an immaturity of the exocrine pancreas to respond to secretogogues.

Age Factors↗

Plasma somatostatin and cholecystokinin levels in sick preterm infants during their first six weeks of life.

The present study reports the levels of plasma somatostatin and cholecystokinin in 19 preterm infants with asphyxia [n = 10, GA (median; range) 26; 23-30 weeks] and respiratory distress syndrome (n = 14, GA 27; 23-29 weeks) compared with preterm infants without any of these conditions (reference group, n = 59, GA 33; 25-36 weeks). In the reference group 37 infants received phototherapy and their peptide levels were compared with those not receiving phototherapy (n = 22). Plasma somatostatin and cholecystokinin were analysed by specific radioimmunoassays on day 1, day 3-4 and at 6 weeks of life. Plasma somatostatin levels, but not cholecystokinin levels, of reference infants were inversely related to gestational age on day 1 and day 3-4. Asphyxiated infants and infants with respiratory distress syndrome had significantly higher somatostatin levels than reference infants on day 1 and day 3-4. These differences disappeared when the levels were adjusted for gestational age. Plasma cholecystokinin levels were not influenced by respiratory distress syndrome and asphyxia. Phototherapy did not affect plasma somatostatin and cholecystokinin levels.

Asphyxia Neonatorum↗

Plasma somatostatin and cholecystokinin levels in preterm infants during their first two years of life.

Plasma somatostatin and cholecystokinin are two gut peptides with opposite functions which are regulated by two different parts of the autonomic nervous system. Previously we have shown that plasma somatostatin and cholecystokinin levels are higher in preterm infants during the 1st d of life than in adults or in their mothers, and that plasma somatostatin is negatively correlated to gestational age. We have longitudinally studied these two peptides in 28 preterm infants, 17 boys and 11 girls, up until the age of 2 y. The mean (SD) gestational age was 32.3 (2.8) wk, the mean birth weight was 1877 (515) g, and the mean birth length was 42.8 (3.8) cm. Blood samples were taken on the 1st d of life, at 6 wk, and at 3, 6, 12, and 24 mo of age. Plasma was analyzed by specific somatostatin and cholecystokinin RIAs. The median plasma somatostatin and cholecystokinin levels were lowest at 3 mo (somatostatin = 17.4/cholecystokinin = 10.5 pmol/L) and highest at 6 mo (somatostatin = 37.3/cholecystokinin = 27.1 pmol/L). At 24 mo plasma somatostatin remained at the same level, and cholecystokinin had decreased to half that level. After the 1st d of life plasma somatostatin and cholecystokinin levels were not correlated to gestational age or attained weight or length. The plasma somatostatin level at 3 mo of age was negatively correlated to the increment in knee-heel distance between 3 and 6 mo of age.

Adult↗

Small bowel biopsy in Swedish paediatric clinics.

The capsule technique for small bowel biopsy performed at Swedish paediatric clinics was evaluated using two questionnaires in 1990 and 1993, respectively. Replies were received from all 45 centres which together perform approximately 2300 biopsies per year. Clotting function tests prior to biopsy were carried out in 42% of the centres. The biopsies were performed under intubation anaesthesia in 13% of the centres. The most striking difference between the answers to the two questionnaires was the mode of sedation. The use of intravenous sedatives increased from 40% of the centres in the first questionnaire to 59% in the second one. The use of the oral, rectal and intramuscular routes decreased correspondingly. The most frequently used drugs for intravenous sedation were benzodiazepines, in the first questionnaire diazepam and in the second one midazolam. The failure rate was approximately 5%. In the first questionnaire, no complication was encountered. In the second questionnaire, three cases of intramural duodenal haematoma were reported, one of which led to pancreatitis. We conclude that by focusing on questions of sedation these rather simple questionnaires may have resulted in more effective sedation of children undergoing small bowel biopsy.

Biopsy↗

Plasma somatostatin and cholecystokinin levels in preterm infants during the first day of life.

Our knowledge about regulatory gut peptides in preterm infants is scanty. We therefore began a study of plasma somatostatin (SS) and cholecystokinin (CCK) in preterm infants at birth and during the neonatal period. Plasma SS and CCK levels were assessed in 77 mothers and in 91 preterm infants immediately after birth (umbilical cord) and during the first day of life (1F) (n = 69, median age 5 h). The gestational age ranged from 23 to 36 weeks and the birth weight from 460 to 3,350 g. After Sep-Pak C18 semichromatography of plasma, SS and CCK were analyzed by RIA. Both plasma SS and CCK levels increased significantly during the first hours of life. Plasma SS levels were negatively correlated to gestational age, birth weight and birth length. When the SS-1F levels were adjusted for gestational age in a multivariate analysis there was no independent association with birthweight but a weak association with birth length. Plasma CCK-1F levels were not correlated with any of these variables. Plasma SS-1F levels were lower after cesarean section. Plasma SS and CCK levels during the first day were not correlated to multiple birth, mode of anesthesia, umbilical pH, Apgar score and blood glucose level before first meal.

Adolescent↗