[Pyomyositis of the M. quadriceps femoris in an 8-month-old boy following pneumococcal meningitis]

An 8-month-old boy developed pyomyositis of the M. quadriceps femoris following meningitis caused by Streptococcus pneumoniae. The child had no underlying immune defect. Conservative treatment with antibiotics led to complete clinical and radiological resolution of the infection. In Europe, pyomyositis is rarely seen in children. Pyomyositis should be considered in the differential diagnosis in children with fever and complaints of joint pain or myalgia. Ultrasound and MRI are helpful techniques for establishing the diagnosis and for differentiating pyomyositis from other pathological conditions. Treatment consists of adequate antibiotics and in some cases drainage.

[Diagnostic methods for Helicobacter pylori infection in children]

A Helicobacter pylori infection is usually acquired during early childhood. Poor socioeconomic circumstances form an important risk factor for this. An untreated infection may lead to peptic ulceration and, particularly in adults, to gastric cancer and mucosa associated lymphoid tissue (MALT) lymphoma. The gold standard for the diagnosis of H. pylori infection is gastroscopy with histology and culture of biopsy specimens. Non-invasive tests are serology, 13C-urea breath test and stool antigen test. The sensitivity and specificity of serology tests are low in children, but for both the 13C-urea breath test and the stool antigen test the sensitivity and specificity are high. A 'test and treat' approach is advised with due consideration for possible symptoms and the risk for peptic ulcers and gastric cancer at a more advanced age. The treatment results must be evaluated. If necessary, young children can be treated at a later age.

Hepatoblastoma in a girl with biliary atresia: coincidence or co-incidence

Hepatoblastoma (HB) and biliary atresia (BA) are both rare conditions that occurred in the patient described. This is the second such case in the literature. An explanation for this apparent coincidence could possibly be found in the existance of pluripotent liver stem cells. In humans, small epithelial cells (SEC) behave as pluripotent stem cells. These are cells that can develop as biliary epithelial cells or as liver parenchymal cells, and are thought to be the precursor cell of HB. They are present in a much higher concentration in the livers of patients with BA, which may make them prone to develop HB.

[Dientamoeba fragilis: possibly an important cause of persistent abdominal pain in children]

OBJECTIVE

To determine the effect of an antiprotozoic treatment on children with persistent abdominal pain and infection with Dientamoeba fragilis.

DESIGN

Retrospective.

METHOD

A total of 43 children with D. fragilis infection and persistent gastrointestinal complaints were included in the study. Of these 27 were treated with clioquinol and 16 with a nitroimidazole drug: metronidazole or tinidazole. The parasitological and clinical effects of the treatment were assessed.

RESULTS

In 33 of the 43 (77%) children, no parasites were detected during follow-up with a triple faeces test: 22/27 following treatment with clioquinol and 11/16 following treatment with a nitroimidazole drug. In 27 of the 33 (82%) children with a negative follow-up result, gastrointestinal complaints were considerably less or had completely disappeared. In 2 of the 10 (20%) children in which D. fragilis had not disappeared in the follow-up period, the complaints were less or had disappeared.

CONCLUSION

Effective treatment of D. fragilis infection in children with longstanding gastrointestinal complaints often resulted in a reduction or disappearance of the complaints.

Sphenoethmoidal encephalocele: a case report

OBJECTIVE

This article documents the characteristics and treatment of an infant patient with a sphenoethmoidal encephalocele. An extracranial, transpalatal approach was used to eliminate the encephalocele.

Choledochal cysts: age of presentation, symptoms, and late complications related to Todani's classification

PURPOSE

The aim of this study was to compare presentation, complications, diagnosis, and treatment of choledochal cysts in pediatric and adult patients.

METHODS

Forty-two patients were analyzed after subdivision into 3 groups: group A, less than 2 years (n = 10); group B, 2 to 16 years (n = 11); group C, greater than 16 years (n = 21).

RESULTS

The cysts were classified as extrahepatic (n = 33), intrahepatic (n = 5), and combined (n = 4). Seventy-six percent of patients presented with abdominal pain, (20 of 21 group C), and 57% with jaundice, (10 of 10 group A). Cholangiocarcinoma occurred in 6 patients, 4 of whom had previously undergone internal drainage procedures. Excision of the extrahepatic cyst was performed in 27 of 37 patients. Five patients, of whom, 4 had cholangiocarcinoma, were beyond curative treatment at the time of diagnosis. Six patients had died at the closure of this study, 5 of them had carcinoma.

CONCLUSIONS

Presenting symptoms are age dependent with jaundice prevailing in children and abdominal pain in adults. In view of the high risk of cholangiocarcinoma, early resection and not internal drainage is the appropriate treatment of extrahepatic cysts. Patients who had undergone internal drainage in the past still should undergo resection of the cyst.

[Microvillus inclusion disease, a rare cause of severe congenital diarrhea]

To date, microvillus inclusion disease (MID) has been diagnosed in six Dutch patients. It is a rare autosomal recessive hereditary intestinal disorder mostly presenting with malabsorption and severe secretory diarrhoea from birth. The diagnosis is confirmed by electron microscopy of intestinal mucosal biopsies, which show characteristic intracytoplasmic vesicles containing clearly recognisable microvilli and irregularly distributed microvilli in the brush border. The two clinical forms of the disease that have been recognised internationally, a 'congenital' and a 'late-onset' form of MID, have also been observed in the Dutch patients. At the last follow-up five patients had died, the sixth was 17 years old and alive. The pathogenesis and genetics of MID are, as yet, unknown. Eventually, all patients die from complications of the disease, notably from the total parenteral nutrition. The only chance of survival is intestinal or combined liver-intestinal transplantation.

Helicobacter pylori Stool Antigen test: a reliable non-invasive test for the diagnosis of Helicobacter pylori infection in children

OBJECTIVE

To evaluate the Helicobacter pylori Stool Antigen (HpSA) test for the diagnosis of H. pylori infection in children.

DESIGN AND SETTING

Prospective cohort study in an academic medical centre.

PATIENTS AND METHODS

A total of 106 consecutive children who underwent gastroscopy were included. Biopsy specimens were sampled from the gastric antrum and corpus for the assessment of H. pylori infection by culture and histology. A patient was defined to be H. pylori positive if the results of culture and/or histology proved to be H. pylori positive; a patient was defined to be negative if both test results were negative. All children provided a stool sample within 2 days of gastroscopy. H. pylori antigens in faeces were assessed by an enzyme immunoassay (Premier HpSA, Meridian Diagnostics, Inc., Cincinnati, OH, USA).

RESULTS

The mean age of included patients was 8.5 years (range 1-18.5). Thirty patients were H. pylori positive and 76 patients were H. pylori negative. Using the recommended cut-off values of 0.140 optical density (OD) and 0.159 OD, sensitivity and specificity of 100% and 92% were found. The positive and negative predicting values were 83% (30/36) and 100% (70/70), respectively.

CONCLUSION

The HpSA test is an accurate test for the diagnosis of H. pylori infection in children, and might therefore be a good alternative for diagnostic tests such as the 13C-urea breath test (UBT).

[Fabry's disease; towards a treatment]

Fabry's disease, deficiency of the enzyme alpha-galactosidase A, is an X-linked lysosomal storage disorder. Clinical symptoms are caused by continuous deposition of specific glycolipids in endothelial cells, neural cells, skin and cornea. These depositions give rise to skin (angiokeratoma) and eye abnormalities (cornea verticillata), acroparaesthesias and anhidrosis and later in life cause renal insufficiency and cardiovascular complications. Hemizygous males suffer from Fabry's disease, whereas female carriers (heterozygotes) are usually asymptomatic. Recently, an atypical presentation of Fabry's disease was described in males who only presented with cardiac involvement. Therefore, the actual number of Fabry patients in the Netherlands could be higher than the predicted 300. Diagnosis in males can be established by measuring alpha-galactosidase enzyme activity in plasma, leukocytes or fibroblasts. Apart from kidney transplantation only symptomatic therapy is available today. Enzyme supplementation therapy (as shown in Gaucher's disease) and substrate deprivation are possible ways of treatment in the future.

[Percutaneous endoscopic gastrostomy in children with psychomotor retardation; less complaints and not as stressful]

OBJECTIVE

To evaluate the effects of percutaneous endoscopic gastrostomy (PEG) in children with psychomotor retardation.

DESIGN

Prospective.

METHOD

Data on symptoms, pros and cons and complications were collected by means of questionnaires from the parents of children with psychomotor retardation and severe nutritional problems in whom a PEG tube had been introduced between August 1995 and March 1998 in the department of Children's Gastroenterology and Nutrition of the Emma Children's Hospital/Academic Medical Centre in Amsterdam, the Netherlands, comparing the situations before the introduction and 6 and 18 months afterward.

RESULTS

The patient group consisted of 17 boys and 23 girls with a mean age of 6 years and 3 months (range 8 months-10 years and 1 month). The frequency of vomiting and of airway infections decreased and the general nutritional condition improved. Restlessness and pain occurred less often in over half the children. The disadvantages most often reported were the logistics concerning the feeding (n = 11) and the reduced contact with the child (n = 10). Thirteen children displayed mild side effects such as skin irritation and proud flesh. Technical problems consisted of leakage (n = 11) and obstruction of the tube (n = 2). In one child, introduction of the tube was followed by a major complication.

CONCLUSION

The PEG tube in this patient group reduced the frequency of complaints about nutrition and constituted a patient-friendly alternative to the nasal tube.

[Immunology in medical practice. XXII. T-cells and strategies for tolerance induction]

Up to the present, aspecific immunosuppressive medication is still required to prevent rejection of transplanted allogeneic tissues and to treat autoimmune disorders. These drugs are associated with numerous adverse effects. Therefore, alternative forms of immunomodulation are being extensively studied. T-cells play a central role in regulating the immune system. Expanding insight into the cellular mechanisms involved in immune recognition and activation led to the development of new tolerance-inducing strategies. Potential sites for tolerance induction are situated centrally in the thymus as well as in the peripheral T-cell population. Explicitly mentioned tolerance strategies are (a) allogeneic bone marrow transplantation and intrathymic tolerance induction (central tolerance induction), (b) peripheral T-cell clonal deletion, induction of anergy and immune deviation (all three are examples of peripheral tolerance induction).

The effect of extrahepatic cholestasis on liver regeneration after partial hepatectomy in the rat

Liver regeneration after partial hepatectomy was studied in four groups of rats: control rats (n = 12), rats with 1 week of common bile duct obstruction (n = 11), rats with restoration of bile flow after 1 week of obstruction (n = 9) and a sham-operated group (n = 7). Parameters of DNA synthesis--thymidine kinase activity and in vivo bromodeoxyuridine incorporation--were measured at partial hepatectomy (T = 0), and 24 and 48 h after partial hepatectomy. During common bile duct obstruction, DNA synthesis was already stimulated at T = 0, but partial hepatectomy in common bile duct obstruction rats induced a delayed DNA synthesis. After 1 week of restoration of bile flow, normal DNA synthesis had returned at T = 0, but DNA synthesis after partial hepatectomy was still delayed. The sham-operated rats showed a normal regeneration response after partial hepatectomy assessed by bromodeoxyuridine incorporation but delayed as assessed by thymidine kinase activity, partly due to the impaired physical condition of the animals. The present data support the hypothesis that during cholestasis, regeneration promoting, and inhibitory factors accumulate in the liver, their balance determining whether regeneration after partial hepatectomy will occur in a normal, enhanced or delayed way.

Neocortical dialysate monoamines of rats after acute, subacute, and chronic liver shunt

Intracerebral microdialysis was applied to monitor the neocortical extracellular levels of the aromatic amino acids phenylalanine, tyrosine, and tryptophan, the neurotransmitters dopamine (DA), noradrenaline (NA), and serotonin (5-HT), and the metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole-3-acetic acid (5-HIAA) in rats with various forms of experimental hepatic encephalopathy (HE). The extracellular aromatic amino acid levels were clearly increased in acute, subacute, and chronic HE. No changes compared with controls in the neocortical DA release could be detected in the three experimental HE rat models investigated. The NA release showed a significant increase only in the subacute HE group. These data suggest that HE may not be associated with any major reduction of neocortical DA or NA release as previously suggested. In acute and subacute HE, decreased extracellular DOPAC but elevated 5-HIAA concentrations were seen. In chronic HE, elevations of both DOPAC and 5-HIAA were observed. Neocortical 5-HT release did not change in subacute and chronic HE, whereas it decreased in acute HE compared with control values. Significant increase in extracellular concentrations of 5-HIAA and of the 5-HIAA/5-HT ratio in the present study are in agreement with previously reported increases in 5-HT turnover in experimental HE. However, a substantially increased 5-HT turnover in experimental HE does not appear to be related to an increase in neuronal neocortical 5-HT release.

Three different hepatocyte transplantation techniques for enzyme deficiency disease and acute hepatic failure

The effects of three different techniques of hepatocyte transplantation were investigated: transplantation of free hepatocytes into the spleen and intraperitoneal transplantation of microcarrier-attached hepatocytes or of microencapsulated hepatocytes. The liver-supportive functions of these transplanted hepatocytes were analyzed using either the Gunn rat (hyperbilirubinemia) or rats with acute liver failure. In the Gunn rat intraperitoneal transplantation of microcarrier-attached hepatocytes resulted in a significant reduction of plasma bilirubin for 28 days whereas intraperitoneal transplantation of microencapsulated hepatocytes was ineffective notwithstanding immunosuppression by cyclosporin A. Intrasplenic hepatocyte transplantation was only effective in reducing plasma bilirubin for 14 days. During acute liver failure, liver support was achieved temporarily by hepatocyte transplantation in the spleen, by intraperitoneally transplanted microcarrier-attached hepatocytes, and by microencapsulated hepatocytes to equal extents, the microencapsulated hepatocytes being the least effective after 8 h of liver ischemia.

Amino acid release from cerebral cortex in experimental acute liver failure, studied by in vivo cerebral cortex microdialysis

Both increased gamma-aminobutyric acid (GABA)-ergic and decreased glutamatergic neurotransmission have been suggested relative to the pathophysiology of hepatic encephalopathy. This proposed disturbance in neurotransmitter balance, however, is based mainly on brain tissue analysis. Because the approach of whole tissue analysis is of limited value with regard to in vivo neurotransmission, we have studied the extracellular concentrations in the cerebral cortex of several neuroactive amino acids by application of the in vivo microdialysis technique. During acute hepatic encephalopathy induced in rats by complete liver ischemia, increased extracellular concentrations of the neuroactive amino acids glutamate, taurine, and glycine were observed, whereas extracellular concentrations of aspartate and GABA were unaltered and glutamine decreased. It is therefore suggested that hepatic encephalopathy is associated with glycine potentiated glutamate neurotoxicity rather than with a shortage of the neurotransmitter glutamate. In addition, increased extracellular concentration of taurine might contribute to the disturbed neurotransmitter balance. The observation of decreasing glutamine concentrations, after an initial increase, points to a possible astrocytic dysfunction involved in the pathophysiology of hepatic encephalopathy.

A localized in vivo detection method for lactate using zero quantum coherence techniques

A method is described to selectively measure lactate in vivo using proton zero quantum coherence techniques. The signal from lipids is eliminated. A surface coil and additionally slice selective localization are used. The resulting spectra demonstrate the good performance of the method.

The effects of benzodiazepine-receptor antagonists and partial inverse agonists on acute hepatic encephalopathy in the rat

Two benzodiazepine-receptor partial inverse agonists (Ro 15-4513, Ro 15-3505) and one benzodiazepine-receptor antagonist (flumazenil) were administered to rats with hepatic encephalopathy due to acute liver ischemia. Significant improvement (P less than 0.002) of both the clinical grade of hepatic encephalopathy and the electroencephalographic abnormalities was observed after administration of the benzodiazepine-receptor partial inverse agonists: comatose rats with no spontaneous righting reflex regained consciousness immediately after injection of the drug. Only slight improvement in clinical hepatic encephalopathy grade was seen after administration of 25 mg/kg of flumazenil. The present data strongly support a role of increased gamma-aminobutyric acid-ergic tone in the pathogenesis of acute hepatic encephalopathy and provide a rationale for trials of benzodiazepine-receptor partial inverse agonists to restore consciousness in hepatic encephalopathy in humans in the near future.

Liver regeneration after partial hepatectomy in rats with defective bilirubin conjugation or biliary excretion

The role of conjugated bilirubin in liver regeneration after partial hepatectomy (PH) was studied in Gunn rats, in transport-mutant (TR-) rats, and in rats with extrahepatic biliary obstruction. Ornithine decarboxylase (ODC) and thymidine kinase (TK) activities in liver homogenates and immunohistochemistry of in vivo bromodeoxyuridine (BrdU) incorporation in hepatic DNA were followed as regeneration parameters at 24 and 48 hr after PH. The results relative to TK activity and BrdU incorporation were consistent with significantly delayed hepatic DNA synthesis in Gunn rats in comparison to control Wistar and TR- rats. This delay in DNA synthesis was not reflected in the hepatic ODC activity. After one week of complete common bile duct obstruction (CBO), an increased TK activity and BrdU incorporation was seen. PH following CBO resulted in a further increase in ODC activity and BrdU incorporation. TK activity did not change, however. These data relative to the regulation of hepatic DNA synthesis after PH in Gunn rats and in rats with extrahepatic biliary obstruction suggest a possible stimulatory role for conjugated bilirubin in hepatic regeneration; however, the normal hepatic DNA synthesis in TR- rats studied before PH and the subnormal DNA synthesis seen 24 hr after PH in TR- rats and in rats with CBO indicate that conjugated bilirubin does not stimulate hepatic DNA synthesis.

The relationship between plasma free fatty acids and experimentally induced hepatic encephalopathy in the rat

Two experimental models of hepatic encephalopathy in the rat have been investigated in order to study the postulated relationship between plasma free fatty acids concentration (C6 - C22:0) and the degree of hepatic encephalopathy. As a model of chronic hepatic encephalopathy, porta caval shunted rats were studied for 15 weeks, whereas rats with acute liver ischemia were used as a model for acute hepatic encephalopathy. In porta caval shunted rats only a minor degree of hepatic encephalopathy developed, whereas plasma ammonia concentration increased significantly (82 +/- 8 to +/- 440 +/- 32 mumol/l). Acute liver ischemia induced severe grades of hepatic encephalopathy associated with high levels of plasma ammonia (+/- 1 200 mumol/l). Since no significant changes in plasma free fatty acids were observed during both chronic and acute hepatic encephalopathy no correlation between plasma free fatty acids and the stage of hepatic encephalopathy was found. Our data do not support an important role of free fatty acids in the pathogenesis of acute or chronic hepatic encephalopathy in the rat.

Changes in brain metabolism during hyperammonemia and acute liver failure: results of a comparative 1H-NMR spectroscopy and biochemical investigation

The effects of hyperammonemia on brain function have been studied in three different experimental models in the rat: acute liver ischemia, urease-treated animals and methionine sulfoximine-treated animals. To quantify the development of encephalopathy, clinical grading and electroencephalographic spectral analysis were used as indicators. In all three experimental models brain ammonia concentrations increased remarkably associated with comparable increases in severity of encephalopathy. Furthermore, in vivo 1H-nuclear magnetic resonance spectroscopy of a localized cerebral cortex region showed a decrease in glutamate concentration in each of the aforementioned experimental models. This decreased cerebral cortex glutamate concentration was confirmed by biochemical analysis of cerebral cortex tissue post mortem. Furthermore, an increase in cerebral cortex glutamine and lactate concentration was observed in urease-treated rats and acute liver ischemia rats. As expected, no increase in cerebral cortex glutamine was observed in methionine sulfoximine-treated rats. These data support the hypothesis that ammonia is of key importance in the pathogenesis of acute hepatic encephalopathy. Decreased availability of cerebral cortex glutamate for neurotransmission might be a contributing factor to the pathogenesis of hyperammonemic encephalopathy. A surprising new finding revealed by 1H-nuclear magnetic resonance spectroscopy was a decrease of cerebral cortex phosphocholine compounds in all three experimental models. The significance of this finding, however, remains speculative.

Metabolic activity of microcarrier attached liver cells after intraperitoneal transplantation during severe liver insufficiency in the rat

Short- and long-term effects of intraperitoneally transplanted microcarrier attached liver cells (MAL) have been studied in two experimental models of severe liver insufficiency in the rat: subtotal hepatectomy (HX) and acute liver ischemia. Intraperitoneal transplantation of MAL immediately after subtotal hepatectomy resulted in a significantly lower plasma ammonia level, a higher caffeine clearance, a higher urea production and a significantly smaller loss in body weight in comparison to sham transplanted control rats. Since thymidine kinase activity in the regenerating host liver was only significantly stimulated at t = 48 h it is concluded that the observed metabolic effects are mainly due to the metabolic activity of the transplanted MAL, although a small stimulative effect of MAL-TX on host liver regeneration cannot be excluded. In the course of acute liver ischemia, MAL transplantation results in delayed development of acute hepatic encephalopathy (HE), judged by clinical grading, EEG spectral analysis and Visual Evoked Response (VER) parameters. Furthermore, MAL transplantation is associated with less increased levels of plasma ammonia during acute liver ischemia.

Liver regeneration

Despite great advances in analysing hemodynamic, morphological and biochemical changes during the process of liver regeneration, the exact (patho)physiological mechanism is still unknown. A short survey of literature is given of the kinetics of liver regeneration and the significance of different hepatotrophic factors. A distinction is made between factors promoting cell hypertrophy and factors stimulating hyperplasia. Loss of cell-cell contact inhibition, metabolic overload or elimination of inhibitory substance are discussed as trigger mechanisms for cell proliferation after partial hepatectomy (PH). Trophic factors like insulin may create optimal conditions for cell growth. The Hepatic Stimulatory Substance (HSS) of LaBrecque is probably the most purified proliferation factor at present, but there are several claims for other hepatotrophic factors too.