The effect of protein intake on the lifelong changes in renal function of rats with a solitary kidney damaged at young age

Changes in renal function were followed lifelong in male rats with only 1 kidney either intact or damaged by ureteral obstruction or ischemia. After surgery the rats were given a low (12%) or a high (36%) protein diet. After a period with a stable glomerular filtration rate, which was longer on the low protein diet, there was a linear decline in rats with an intact single kidney. The rate of decline was highest on the high protein diet, resulting in a shorter survival time. A decrease in urine osmolality and an increase in protein excretion preceded the decrease in filtration rate, while it was followed by an increase in blood pressure. The glomerular filtration rate of the rats with a single damaged kidney initially recovered to 75 to 80% of that of rats with an intact single kidney on the same diet. There was a linear decrease in the glomerular filtration rate, with the highest rate of decrease on the high protein diet. The mean survival time was less than that of rats with a single intact kidney. Proteinuria preceded the decrease in filtration rate, while hypertension was observed later. We conclude that in rats with a solitary kidney renal failure eventually develops. A low protein diet postpones and attenuates this development but it does not prevent it.

Formation and malformation of the enteric nervous system in mice: an organ culture study

Despite some progress in the treatment of congenital malformations of the enteric nervous system, there is no knowledge about the pathogenesis. The study of the normal formation of the enteric nervous system is hampered by the difficulty of manipulating and culturing mammalian embryos and their organs. Three methods to culture bowel explants of murine embryos, (chorioallantoic membrane grafting, organotypic tissue culture, and renal subcapsular space grafting) were compared. The three-dimensional cytoarchitecture of the bowel developed almost normally in the renal subcapsular space cultures. Using this culture system, it was found that neural crest cells colonize the murine bowel in distinct phases. The distal bowel was colonized at the 13th day of development. In a spontaneous mouse mutant model for intestinal aganglionosis, the lethal spotted mouse, the colonization of the distal 2 mm of the bowel did not occur at E13.

Carnitine deficiency in surgical neonates receiving total parenteral nutrition

Carnitine plays a key role in the oxidation of fatty acids. Most solutions for parenteral nutrition do not contain carnitine. Because endogenous carnitine synthesis is insufficient in newborns, they are prone to developing a carnitine deficiency when they are dependent on total parenteral nutrition (TPN). Stimulated by the clinical observation of manifest clinical symptoms of carnitine deficiency in one patient, a study of 13 consecutive neonates who received TPN for over 2 weeks was begun. Their plasma carnitine levels before and during carnitine supplementation were determined. All patients had a carnitine intake far below the recommended minimal need of 11 mumol/kg per day. Although only three of them clearly showed clinical symptoms described as carnitine deficiency, carnitine supplementation for all neonates receiving TPN for over 2 weeks is recommended.

Experimentally induced congenital diaphragmatic hernia in rats

Experiments to induce congenital diaphragmatic hernia (CDH) in rats, by means of administering a single dose of 2,4-dichlorophenyl-P-nitrophenyl (Nitrofen) on the 10th day of gestation, are reported here. Previously, congenital diaphragmatic hernia has been induced in sheep late in fetal development, and in mice early in gestation. The rat model, including a control group, was used to evaluate lung development and the presence of lung hypoplasia by morphometrical analysis. It was found that the single dose of Nitrofen, given 5 days before the normal closure of the diaphragm in the rat, leads to a high incidence of diaphragmatic hernia, mainly on the right side, and highly abnormal lung development (hypoplasia) comparable to the human situation. Both the lung weight/body weight index as well as the radial alveolar count were significantly lower in animals with CDH (P less than .05). This animal model offers a good opportunity to study abnormal lung development in relation to ventilatory capacity and pulmonary vascular reactivity.

Total parenteral nutrition associated cholestasis: a predisposing factor for sepsis in surgical neonates?

Of 496 neonates and infants less than 1 year of age admitted to the paediatric surgical intensive care unit (PSICU) over a 5 year period (1983-1987), 94 required total parenteral nutrition (TPN) for more than 14 consecutive days, generally due to congenital anomalies of the digestive tract. Cholestasis occurred in 15 of them and 12 of these patients developed sepsis. In contrast, of the 79 patients on TPN that remained free from cholestasis, only 23 developed sepsis. The mortality rate for the TPNAC-group was substantially higher than for the group without TPNAC. It is suggested that development of TPNAC might lead to impairment of non-specific cellular immunity in neonates.

Long-term follow-up of renal function in rats with unilateral hydronephrosis

In order to obtain more information on the long-term changes in renal function of hydronephrotic kidneys, we have measured the glomerular filtration rate (GFR) in rats with a congenital or an experimental unilateral hydronephrotic kidney (HK). In Brown Norway rats, with congenital hydronephrosis, the presence of an HK affected neither the total GFR nor the contribution of that kidney to the total GFR, during a follow-up of 70 weeks. In Wistar rats with experimental unilateral hydronephrosis two groups could be distinguished on the basis of the contribution of the HK to the total GFR. In the first, the contribution of the HK to the total GFR was not different from that of controls. This contribution as well as the total GFR remained similar to that of controls during the follow-up. In the second group, the contribution of the HK to the total GFR was reduced to 25%. In these rats the total GFR was slightly less than that of controls. The contribution of the HK to the total GFR remained unchanged for the next 56 weeks. It is concluded that the long lasting presence of unilateral hydronephrosis in rats does not necessarily result in a progressive loss of renal function with time.

[Psychosocial aspects of the so-called short-bowel syndrome in children]

In a retrospective study of 16 patients with (congenital) bowel pathology, aged 2 to 12, attention was paid to the psychosocial aspects of the short bowel syndrome. Parents were interviewed and parents' and teachers' reports of children's behavioural and emotional problems were obtained. Parents as well as children appeared to have reached a reasonable level of adjustment. Parents' emotions concerning the period of hospitalisation still appeared to be strikingly strong. Although most children did not show obvious psychopathology, problems were observed in the areas of behaviour and attention, interfering with optimal school functioning in the case of some children.

Sinusitis: hidden source of sepsis in postoperative pediatric intensive care patients

Paranasal sinusitis is reported as a complication of prolonged nasal intubation and the source of sepsis in adult intensive care patients. In surgical neonates with congenital malformations, prolonged intubation with a nasotracheal (NT) or NG tube is often necessary, but sinusitis with complicating sepsis is seldom reported. Sinus x-rays may confirm the diagnosis; in infancy, prolonged nasal intubation delays the pneumatization of the sinuses and the mastoids, resulting in additional diagnostic problems. In a 1-yr period, we saw three patients with multiple septic episodes in which the source of sepsis was undetectable. Despite the absence of clinical symptoms and radiologic evidence of sinusitis or mastoiditis, surgical drainage revealed pus and led to the disappearance of septic episodes and ear, nose, and throat problems. There is an association between prolonged NT and NG intubation, and sinusitis or mastoiditis as an unrecognized source of sepsis in young infants. Absence of radiologic evidence of sinusitis or mastoiditis causes pitfalls in diagnosis and is related to delayed pneumatization of the sinuses and the mastoid in prolonged nasal intubation in young infants.

Proteinuria is an early marker in the development of progressive renal failure in hypertensive fawn-hooded rats

Male spontaneously hypertensive fawn-hooded (FH) rats can be divided into two classes on the basis of their proteinuria. We investigated the relationship between early proteinuria and the impairment of renal function later in life. Urinary protein excretion (UpV), systolic blood pressure (SBP) and parameters of renal function were sequentially determined in male FH rats. A significant difference in UpV was already present from the age of 10 weeks. Class I rats excreted less protein than class II animals. Initially, the glomerular filtration rate (GFR) of class II animals was somewhat higher than that of class I rats, but from week 50 onwards a decrease in GFR of class II rats was noted and from then on rats died due to uraemia. The GFR of class I animals fell from week 75. The fall in GFR was preceded by a concomitant increase in UpV and SBP. The increase occurred earlier and the rate of increase was higher in class II rats. We conclude that a number of hypertensive FH rats die prematurely from end-stage renal failure. The presence of an increased UpV at an early age is an early marker for the development of renal failure.

Potentiated nephrotoxicity of cisplatin when combined with amikacin comparing young and adult rats

We compared the nephrotoxic interaction between cisplatin (CP) and amikacin (AM) in young and adult rats, using different dosage combinations. Following a single i.v. dose of CP, AM was administered s.c. for 14 days. The dose of CP was chosen to cause a 20%-50% fall in the glomerular filtration rate (GFR), while a dose of AM was chosen that had only a minimal effect on GFR. In adult rats, a decrease in GFR to 60% of the control value after CP alone was seriously aggravated by a non-toxic AM course given during 2 weeks after CP. In this combination, the GFR per 100 g body weight was reduced to 30% of control at week 2, which rose to 40% of control at week 15. In young rats, a non-toxic AM course did not aggravate the CP-induced impairment in GFR. However, when the dose of AM was increased to cause a 20% reduction in the GFR, the nephrotoxicity was potentiated. When measured at week 2, the GFR per 100 g body weight was 40% of control after the combined treatment compared with 80% of control after CP alone. As in adult rats, there was only a partial recovery of the GFR. In conclusion, in both adult and young rats, a course of AM following a single injection of CP potentiated CP-induced nephrotoxicity.

Bowel resection in the neonatal phase of life: short-term and long-term consequences

Bowel resection during the neonatal phase of life may be associated with considerable morbidity, both short- and long-term. A retrospective evaluation is reported, concerning 74 patients who underwent bowel resection over a ten-year-period, due to necrotising enterocolitis, atresia, volvulus or Hirschsprung's disease. The cause of death of 15 non-survivors was investigated and the pattern of morbidity of 59 surviving patients was evaluated regarding growth, nutrition and defaecation. It was concluded that the ultimate prognosis for most patients is good, despite considerable morbidity during the first year of life, involving serious losses of fluids and electrolytes, cholestasis, and recurrent sepsis due to central venous catheters.

A model for aganglionosis in the chicken embryo

We investigated the ability of neural crest (NC) cells to colonize hindgut, which had remained aneuronal due to bowel transection in ovo at an early stage. The fact that the bowel remained aneuronal proved that the "sacral" NC does not provide precursor cells for enteric neurons in the hindgut. HNK-1 immunostaining of aneuronal hindgut revealed cell-free, ganglionic structures at the site of the myenteric plexus and a sub-population of mesenchymal cells in the submucosa. We cocultured this particular type of aneuronal bowel with the vagal neural anlage of either quail or chick embryos on the chick chorioallantoic membrane. After 1 week coculture, it appeared that NC cell colonisation of the hindgut had taken place, although there was a difference between the quail-chick and chick-chick model. Quail NC cells had given rise to submucous plexuses and some myenteric plexuses. Chick NC cells had only colonised the submucous region. These findings indicate that the cell-free ganglionic structures hamper neural crest cell colonization in the myenteric region.

Pre-operative stabilisation with delayed repair in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) remains one of the major challenges for paediatric surgeons and paediatric intensive care specialists. Death in patients with CDH is 30-60% worldwide due to severe pulmonary hypoplasia or pulmonary hypoplasia associated with persistent pulmonary hypertension, secondary to hypoxia, metabolic acidosis or myocardial insufficiency. Pre-operative stabilisation of CDH patients might reduce the risks of these complications. In a two-year period 16 high-risk patients with CDH (respiratory insufficiency less than 6 hrs after birth) underwent delayed surgery following a stabilisation period (mean 14 hrs). Continuous suctioning on a nasogastric tube resulted in total resolution of the mediastinal shift on repeat x-rays. The use of the ventilation parameters arterial alveolar oxygen gradient (A-aDO2), oxygenation index (OI) and mean airway pressure (MAP) revealed three different groups of patients: I consisting of 6 survivors, II two preventable deaths and III eight non-survivors. In this way selection of patients with CDH is possible. In patients who do not improve during the stabilisation period alternative ways of treatment have to be evaluated such as extracorporeal membrane oxygenation (ECMO), high frequency oscillation (HFO) or high frequency jet ventilation (HFJV). Application of the ventilation parameters in prospective trials of patients with CDH enables comparison between different ways of treatment in the future.

Total colectomy and ileorectal anastomosis in the treatment of total colonic aganglionosis: a long-term follow-up study of six patients

Six patients with total colonic aganglionosis (TCA) with ileal involvement were treated with a total colectomy and ileorectal anastomosis according to Rehbein. Follow-up lasted from 1 to 7 years and showed no mortality. Postoperative management consisted of total parenteral nutrition initially, followed by gradual introduction of oral feeding beginning with a low-osmolarity low-residue diet, the use of loperamide, an adequate oral intake of salt, and regular bowel deflation. Major postoperative complications disappeared and all patients demonstrated weight gain by the end of the first postoperative year, with normal feeding and two to three soft stools per day.

Urogenital tract abnormalities associated with esophageal atresia and tracheoesophageal fistula

The medical records were reviewed of 127 consecutive patients with esophageal atresia alone and with tracheoesophageal fistula. Systematical genitourinary tract examination in 112 patients showed anomalies in 24 (21.4 per cent). A survey of the literature on this subject is given. Of 8 patients with the VATER association renal involvement was found in 6. The results of urinary tract imaging by excretory urography and ultrasonography are compared to each other. Prompt and appropriate genitourinary tract examination by physical examination, urinalysis, serum creatinine levels and ultrasonography or excretory urography is recommended as a standard in all children with esophageal atresia, with further investigations ordered if indicated by the results of the studies.

Diagnosis of innervation-related motility disorders of the gut and basic aspects of enteric nervous system development

Motility disorders of the gut in children have become a matter of increasing concern for the pediatric surgeon. Infantile hypertrophic pyloric stenosis is the most common disease requiring surgery in early infancy. While this entity was first described as early as 1888 by Hirschsprung, its etiology and pathogenesis are still an enigma. Fortunately, its surgical treatment is simple and safe, which cannot be said of all other motility disorders of the infantile gut. Dysmotility in small bowel atresia and in gastroschisis is related to damaged smooth muscle cells caused by concomitant ischemia of the bowel wall. In contrast, the temporarily adynamic bowel of the prematurely born child, as well as Hirschsprung's disease and related disorders, is the result of anomalies of the intestinal innervation. The pathogenesis of congenital malformations of the enteric nervous system is still a mystery to surgeons and physicians alike. With his pressure studies of the colon, Swenson first recognized Hirschsprung's disease for what it was. This led to the resection of the manometrically diagnosed abnormal colon, which was found to be aganglionic. Histological investigation of the bowel wall became the decisive tool, replacing manometry, in the diagnosis of Hirschsprung's disease. Histochemical investigation of the bowel wall is not conclusive in other malformations of the enteric nervous system, since the presence or absence of enteric neurons is not the definitive factor discriminating between normally and abnormally functioning bowel. Monoclonal antibodies raised against neuron-specific markers may become important tools for differentiation within the spectrum of congenital malformations of the enteric nervous system. The immunocytochemical technique, however, does not provide sufficient information to explain the cause of innervation disorders of the gut in infancy and childhood. Primary migration disturbances or selective disappearance of enteric neurons following ischemia are highly unlikely to cause aganglionosis of the gut. With respect to the pathogenesis and etiology of Hirschsprung's disease, current research is focused on the embryonic bowel (target organ) in plexus formation. The enteric nervous system is still an enigma, although its origin is known, at least in birds. Why neural crest cells travel, along what paths, how they reach their destination, and what may go wrong during the migratory process, are questions that must be answered. There is increasing knowledge concerning the way in which neural crest cells aggregate and form plexuses in the gut. It is largely unknown why neural crest cells settle, in the bowel, at the sites of the myenteric and submucous plexus.(ABSTRACT TRUNCATED AT 400 WORDS)

Renal function in single-kidney rats

Can a single kidney survive for a normal life span? This is the type of question frequently asked by patients and especially by parents of children who lose one kidney in early childhood. Based on our wide experience with single-kidney rats, we will try to give an answer to this question. After the removal of its counterpart, the single remaining kidney will rapidly adapt to the new situation by a compensatory increase in the glomerular filtration rate (GFR) and renal mass. This is true not only for intact kidneys but also for damaged ones. The GFR level obtained by damaged kidneys will be less than that of intact single kidneys, however, depending on the degree of initial damage. The GFR is stable for a certain period of time, which is longer for intact single kidneys than for damaged kidneys and also depends on the daily protein intake; after that renal function will deteriorate. This decline in GFR is preceded by a marked increase in urinary protein excretion. Although the follow-up period is not completed yet, the survival time of single intact kidneys in rats on a normal diet is expected to be 15%-20% less than the normal rat life span. In rats on a lifelong high protein intake the kidney survival time drops to 40% below the normal rat life span. In rats on a moderately reduced protein intake, however, single intact kidneys may survive for a normal life span. The situation is worse for single damaged kidneys. Depending on the severity of the initial damage, kidney survival time will be much less than a normal life span. We studied rats with an initial recovery to 75% of renal function. Despite this initial recovery, the animals died of renal failure within 50% of the expected life span. A low-protein diet prolonged the renal survival by about 12%, a high-protein diet shortened it by the same percentage.

Congenital diaphragmatic hernia: impact of preoperative stabilization. A prospective pilot study in 13 patients

In case of congenital diaphragmatic hernia (CDH), survival generally depends not on prenatal diagnosis, planned delivery, and immediate postnatal operation, but on the gravity of pulmonary hypoplasia and persistent hypertension (PPH). Many vasoactive drugs have become available for lowering PPH, but the mortality rate for CDH still amounts to 40% to 70%. Preoperative stabilization might prevent or at least reduce the risk of PPH. This method was evaluated in a pilot study lasting 15 months and involving 13 patients. All were admitted to the pediatric surgical intensive care unit within six hours of birth, all requiring mechanical ventilation. Continuous suction of the stomach and bowel proved successful in reducing the mediastinal shift. Study parameters were alveolar-arterial oxygenation differences ((A-a)DO2), mean airway pressure (MAP), oxygenation index (OI), and ventilation index (VI), measured on admission and at set times before and after surgery. Eight patients did not survive, but in two cases death was not directly related to CDH. The following conclusions were reached: (1) satisfactory ventilation parameters on admission will remain good during the preoperative stabilization phase and will not be affected by its duration or by subsequent surgery, spelling survival; (2) unsatisfactory ventilation parameters on admission may improve with preoperative stabilization, giving these patients a better chance of survival; and (3) poor ventilation parameters on admission that fail to improve with preoperative stabilization will not improve with surgery or postoperatively, spelling death.