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Biomedical subjects

Y Finkel

Publications and source records attributed to Y Finkel.

At least 37 records · Page 2Linked to original sources

Ontogeny of K+ transport in rat distal colon.

Infants need to retain more K+ than adults to avoid growth retardation. Since the K+ requirements are different in infants (I) and in adults (A), the mechanisms regulating K+ homeostasis should also be different. The colon plays an important role for the regulation of K+ homeostasis. Colonic K+ transport is bidirectional. In this study we have examined the development of colonic K+ transport with special reference to the contribution of different K(+)-transporting pathways. The net colonic K+ uptake, as determined by in vivo perfusion studies and by 86Rb uptake, was significantly higher in I than in A rats. In both I and A colon, approximately 80% of total 86Rb uptake was dependent on vanadate-sensitive P-type adenosinetriphosphatases (ATPases), but the contribution of these different ATPases changes during development. The activity of colonic Na(+)-K(+)-ATPase, measured as ouabain-sensitive Na(+)-dependent ATP hydrolysis and as 86Rb uptake, was lower in I than in A rats. In contrast, the activity of K(+)-ATPases located in apical membrane and measured as ouabain insensitive and SCH-28080 sensitive, as ouabain-sensitive Na(+)-independent ATP hydrolysis, and as 86Rb uptake was significantly higher in I than in A rats. The ratio between apically located K(+)-ATPases and basolateral Na(+)-K(+)-ATPase activities was almost 3.2-fold higher in I than in A colon. We identified with Northern blot the expression of the colonic H(+)-K(+)-ATPase and the Na(+)-K(+)-ATPase alpha-subunits. The alpha-mRNA expression of both ATPases was significantly higher in I than in A rats. The pH and K+ sensitivity of the ouabain-insensitive, SCH-28080-sensitive K(+)-ATPase was the same in I and A colons. In conclusion, the relative activity of apical K+ absorbing ATPases is higher in the I than in the A colon, which should aid infants in retaining K+.

Adenosine Triphosphatases↗

Radiographic patterns and viral studies in childhood pneumonia at various ages.

We aimed at evaluating the relationship between microbial etiology and chest radiograph appearance in various types of pneumonia. In a prospective study, the radiographic findings in 479 cases of acute pneumonia in children were compared with viral etiology and growth of potential bacterial pathogens in nasopharyngeal secretion. As the basis for viral etiology was most conclusive, the material was here classified according to the viral findings. The patients were divided into three age groups: 0-2, 3-5 and 6-15 years. The chest radiograms were analyzed blindly for the presence of hyperinflation and interstitial, alveolar and mixed interstitial-alveolar infiltrates. There was a statistically significant relationship between low age and occurrence of hyperinflation and interstitial infiltrates, and between high age and alveolar infiltrates. No unequivocal relationship was found between type of infiltrates or presence of atelectasis and proven viral etiology. We conclude that chest radiographs are not a useful indicator of microbial etiology in childhood pneumonia.

Acute Disease↗

Endogenous dopamine modulates jejunal sodium absorption during high-salt diet in young but not in adult rats.

BACKGROUND/AIMS: This study was designed to investigate the contribution of endogenous catecholamines to the regulation of small intestinal sodium transport during postnatal development. METHODS: Jejunal permeability was determined by a constant perfusion, nonabsorbable marker technique in weanling, adolescent, and adult rats fed either a high-salt diet or normal-salt diet. Tissue catecholamine levels were determined by high-performance liquid chromatography with electrochemical detection. RESULTS: In 20-day-old but not in 40-day-old rats, a significantly lower net sodium absorption was observed during high-salt diet compared with age-matched controls on normal-salt diet. Inhibition of dopamine synthesis significantly increased the net sodium absorption in 20-day-old rats on high-salt diet compared with untreated 20-day-old rats on high-salt diet. The basal levels of dopamine in 20-day-old rats were twofold higher than in 40-day-old rats. During high-salt diet, both age groups responded with an increase in dopamine production. Norepinephrine levels were significantly higher (30-fold) in 20-day-old rats than in 40-day-old rats, but norepinephrine content was not significantly changed during high-salt diet in either groups. CONCLUSIONS: The results indicate that weanling animals have a greater jejunal sodium absorption than older animals, probably because of higher noradrenergic tonus. A challenge with a high-salt diet results in a decrease of the intestinal sodium absorption in weaning rats but not in adult rats; endogenous dopamine appears to play an important role in this regulation.

Absorption↗

Congenital sodium diarrhea with a partial defect in jejunal brush border membrane sodium transport, normal rectal transport, and resolving diarrhea.

Defective jejunal sodium/proton exchange causes severe, congenital secretory diarrhea. We report a boy who presented typically in utero, but in whom diarrhea resolved during the first year of life. Pregnancy was complicated by polyhydramnios, and an ultrasound at 31 weeks showed a distended fetal small intestine. The abdomen was grossly distended at birth, and profuse secretory diarrhea began immediately. He subsequently thrived on breast milk and electrolyte supplements. Studies of jejunal brush border sodium/proton exchange at 6 months showed a partial defect. Nonequilibrium rectal dialysis showed rectal sodium and potassium transport to be intact. Diarrhea lessened after 9 months, and the patient subsequently required occasional laxatives. These observations suggest that there is a spectrum of congenital abnormality in this exchanger, and that in children with incomplete defects normal colonic sodium salvage can subsequently mask net small intestinal secretion.

Biological Transport↗

The adaptive response of rectal electrolyte absorption to impaired sodium balance in young children.

Rectal electrolyte transport was measured in nine children (median age 160 days) with ileostomies, using a nonequilibrium dialysis technique. Rectal sodium absorption and potassium secretion were significantly higher in children with a subnormal sodium balance compared with children with a positive sodium balance. Rectal sodium absorption and potassium secretion were unchanged after ileostomy closure. These data indicate that rectal electrolyte transport in children can adapt to even modestly impaired sodium balance.

Child, Preschool↗

Staff training: a key factor in reducing intravascular catheter sepsis.

A children's hospital nutritional care team prospectively monitored the frequency of sepsis in central venous catheters used for administering parenteral nutrition. During an initial study period of 12 months, 26/58 (45%) of catheters were removed because of proved sepsis. The possible causes of this alarmingly high rate were examined, with catheter care techniques on the wards coming under particular scrutiny. As a result protocols were modified and an intensive staff training programme implemented throughout the hospital, led by the nutritional care sister. Subsequently, the catheter sepsis rate was significantly reduced with only 9/107 (8%) of consecutive catheters becoming infected. These findings emphasise the key role that education of staff plays in controlling central venous catheter sepsis and the importance and cost effectiveness of special nursing staff in implementing such measures.

Asepsis↗

The effects of a pectin-supplemented elemental diet in a boy with short gut syndrome.

The effect of a pectin-supplemented diet in short gut syndrome was investigated in a 3-year-old boy. Nitrogen absorption was higher and stomach-to-anus transit time was prolonged during pectin supplementation of the enteral feed. Pectin supplementation had no adverse effects on electrolyte balance or glucose absorption. These data indicate that pectin supplementation of enteral feed may enhance nitrogen absorption and seems not to adversely affect absorption in short gut syndrome.

Child, Preschool↗

Paralytic ileus, a serious complication in acute diarrhoea disease among infants in developing countries.

Intestinal hypomotility is a common late complication in infants with acute diarrhoeal disease in pakistan. Among the infants admitted to our gastrointestinal unit with a history of acute diarrhoea, 35% developed abdominal distension and 12% developed the full clinical picture of paralytic ileus. The infants with ileus were treated with decompression and total parenteral nutrition; in this group the mortality rate was 25%. We compared 30 infants who developed ileus (group A) with an age-matched control group of infants (group B) who were admitted because of acute diarrhoea but did not develope ileus. The use of antimotility drugs was significantly more frequent in group A. Serum-K was not different in in group A (3.92 +/- 0.22 mmol/l) and group B (4.32 +/- 0.18 mmol/1). However, there were more patients who had serum-K below 3 mmol/l in group A (8/30) than in group B (5/30). We conclude that the use of antimotility drugs predisposes to the development of ileus in infants with acute diarrhoea. Hypokalemia may contribute to ileus in a few cases but is generally not a prerequisite.

Acute Disease↗

Na,K-ATPase activity in rectal mucosa of children with ulcerative colitis and Crohn's disease.

Mucosal Na,K-ATPase activity was studied in rectal biopsy specimens from 19 children with ulcerative colitis (UC) (mean age, 13 years) and 4 children with Crohn's colitis (mean age, 14 years) and compared with biopsy specimens from 12 control children (mean age, 12 years). The Na,K-ATPase activity was significantly decreased in UC with severe rectal inflammation compared with UC in remission or with children with unspecific symptoms and normal mucosa (p less than 0.001, respectively). A higher enzyme activity was shown with age in the group with normal rectal mucosa and no evidence of inflammatory bowel disease (n = 17). The decreased Na,K-ATPase in UC with severe rectal inflammation might contribute to the diarrhoea by impairment of sodium transport.

Adolescent↗