Early differences in dynamic uptake of 68Ga-PSMA-11 in primary prostate cancer: A test-retest study.

INTRODUCTION: Dynamic PET/CT allows visualization of pharmacokinetics over the time, in contrast to static whole body PET/CT. The objective of this study was to assess 68Ga-PSMA-11 uptake in pathological lesions and benign tissue, within 30 minutes after injection in primary prostate cancer (PCa) patients in test-retest setting. MATERIALS AND METHODS: Five patients, with biopsy proven PCa, were scanned dynamically in list mode for 30 minutes on a digital PET/CT-scanner directly after an intravenous bolus injection of 100 MBq 68Ga-PSMA-11. Approximately 45 minutes after injection a static whole body scan was acquired, followed by a one bed position scan of the pelvic region. The scans were repeated approximately four weeks later, without any intervention in between. Semi-quantitative assessment was performed using regions-of-interest in the prostate tumor, bladder, gluteal muscle and iliac artery. Time-activity curves were extracted from the counts in these regions and the intra-patient variability between both scans was assessed. RESULTS: The uptake of the iliac artery and gluteal muscle reached a plateau after 5 and 3 minutes, respectively. The population fell apart in two groups with respect to tumor uptake: in some patients the tumor uptake reached a plateau after 5 minutes, whereas in other patients the uptake kept increasing, which correlated with larger tumor volumes on PET/CT scan. Median intra-patient variation between both scans was 12.2% for artery, 9.7% for tumor, 32.7% for the bladder and 14.1% for the gluteal muscle. CONCLUSION: Dynamic 68Ga-PSMA-11 PET/CT scans, with a time interval of four weeks, are reproducible with a 10% variation in uptake in the primary prostate tumor. An uptake plateau was reached for the iliac artery and gluteal muscle within 5 minutes post-injection. A larger tumor volume seems to be related to continued tumor uptake. This information might be relevant for both response monitoring and PSMA-based radionuclide therapies.

Determinants of mild clinical symptoms in cystic fibrosis patients. Residual chloride secretion measured in rectal biopsies in relation to the genotype.

Previous Ussing chamber measurements of secretagogue-provoked changes in short circuit current in rectal suction biopsies of cystic fibrosis (CF) patients showed that in a minority of patients chloride secretion in response to cholinergic agonists is reduced but not completely absent. To assess a possible relationship between this phenomenon and both the genotype and the phenotype, we performed Ussing chamber experiments on rectal suction biopsies of 51 CF patients. The CF mutation was identified in 89 out of 102 CF alleles. No apparent chloride secretion was found in 30 CF patients (group I). Low residual chloride secretion was found in 11 CF patients (group II), while a relatively high residual secretion appeared in 10 CF patients (group III). Pancreatic function was preserved more frequently in CF patients displaying residual secretion: 0% in group I, 27% in group II, and 60% in group III (P < 0.001). The age at diagnosis (mean +/- SEM) in group III (18.4 +/- 6.6) was significantly different from group I (1.2 +/- 0.4, P < 0.01) and group II (3.5 +/- 1.4, P = 0.05). Residual chloride secretion was found in some of the 28 dF508 homozygous patients (three in group II, and one in group III), disclosing that other factors than the CF gene defect itself affect the transepithelial chloride transport. The age at diagnosis correlates significantly with the magnitude of the secretory response, even within the dF508 homozygous patients (r = 0.4, P < 0.05). We conclude that residual chloride secretion in CF is the pathophysiological basis of preserved pancreatic function and delayed presentation of the disease, which is not exclusively determined by the CF genotype.

A newly developed tool for intra-tracheal temperature and humidity assessment in laryngectomized individuals: the Airway Climate Explorer (ACE).

The aim of this study is to develop a postlaryngectomy airway climate explorer (ACE) for assessment of intratracheal temperature and humidity and of influence of heat and moisture exchangers (HMEs). Engineering goals were within-device condensation prevention and fast response time characteristics. The ACE consists of a small diameter, heated air-sampling catheter connected to a heated sensor house, containing a humidity sensor. Air is sucked through the catheter by a controlled-flow pump. Validation was performed in a climate chamber using a calibrated reference sensor and in a two-flow system. Additionally, the analyser was tested in vivo. Over the clinically relevant range of humidity values (5-42 mg H2O/l air) the sensor output highly correlates with the reference sensor readings (R2 > 0.99). The 1-1/e response times are all <0.5 s. A first in vivo pilot measurement was successful. The newly developed, verified, fast-responding ACE is suitable for postlaryngectomy airway climate assessment.

Regulation of chloride transport in cultured normal and cystic fibrosis keratinocytes.

Cultured normal (N) cystic fibrosis (CF) keratinocytes were evaluated for their Cl(-)-transport properties by patch-clamp-, Ussing chamber- and isotopic efflux-measurements. Special attention was paid to a 32 pS outwardly rectifying Cl- channel which has been reported to be activated upon activation of cAMP-dependent pathways in N, but not in CF cells. This depolarization-induced Cl- channel was found with a similar incidence in N and CF apical keratinocyte membranes. However, activation of this channel in excised patches by protein kinase (PK)-A or PK-C was not successful in either N or CF keratinocytes. Forskolin was not able to activate Cl- channels in N and CF cell-attached patches. The Ca(2+)-ionophore A23187 activated in cell-attached patches a linear 17 pS Cl- channel in both N and CF cells. This channel inactivated upon excision. No relationship between the cell-attached 17 pS and the excised 32 pS channel could be demonstrated. Returning to the measurement of Cl- transport at the macroscopic level, we found that a drastic rise in intracellular cAMP induced by forskolin did in N as well as CF cells not result in a change in the short-circuit current (Isc) or the fractional efflux rates of 36Cl- and 125I-. In contrast, addition of A23187 resulted in an increase of the Isc and in the isotopic anion efflux rates in N and CF cells. We conclude that Cl(-)-transport in cultured human keratinocytes can be activated by Ca2+, but not by cAMP-dependent pathways.

Identification of seven novel mutations including the first two genomic rearrangements in SLC26A3 mutated in congenital chloride diarrhea.

Congenital chloride diarrhea (CLD) is an autosomal recessive disorder characterized by defective intestinal electrolyte absorption, resulting in voluminous osmotic diarrhea with high chloride content. A variety of mutations in the solute carrier family 26, member 3 gene (SLC26A3, previously known as CLD or DRA) are responsible for the disease. Since the identification of the SLC26A3 gene and the determination of its genomic structure, altogether three founder and 17 private mutations have been characterized within miscellaneous ethnic groups. We screened for mutations in seven unrelated families with CLD. The diagnoses were confirmed by fecal chloride measurements. The combined PCR-SSCP and sequencing analyses revealed altogether seven novel mutations including two missense mutations (S206P, D468V), two splicing defects (IVS12-1G>C, IVS13-2delA), one nonsense mutation (Q436X), one insertion/deletion mutation (2104-2105delGGins29-bp), and an intragenic deletion of SLC26A3 exons 7 and 8. Two previously identified mutations were also found. This is the first report of rearrangement mutations in SLC26A3. Molecular features predisposing SLC26A3 for the two rearrangements may include repetitive elements and palindromic-like sequences. The increasingly wide diversity of SLC26A3 mutations suggests that mutations in the SLC26A3 gene may not be rare events.

Correction of an inborn error of metabolism by intraportal hepatocyte transplantation in a dog model.

The aims of this study were (1) to assess portal hemodynamics during intraportal hepatocyte transplantation (HTX) in dogs, (2) to evaluate a new method for the detection of transplanted hepatocytes using 5-bromo-2'-deoxyuridine (BrdU) incorporation, and (3) to determine the metabolic effects of HTX on an inborn error of the purine metabolism in dalmatian dogs. HTX was performed by intraportal infusion of freshly isolated allogeneic beagle hepatocytes. Portal flow and pressure were monitored continuously during HTX. For the detection experiments, beagles received hepatocytes that had been exposed to BrdU during regeneration of the donor liver, induced by partial hepatectomy. For metabolic studies, dalmatian dogs were used as recipients. Repetitive HTX was performed. As judged by the portal hemodynamics, the number of hepatocytes that could be infused safely varied from 5 x 1O(8) to 8 x 1O(8) in beagles, to 1 x 10(9) in dalmatians. Transaminase levels showed a 5- to 6-fold increase (P=0.05) after HTX, but normalized within 3 weeks. BrdU-positive cells were identified in the recipient livers 2 weeks after HTX and 5-10% of the total amount of transplanted hepatocytes was retrieved. A significant (P=0.05) decrease in serum uric acid was demonstrated after repeated HTX in dalmatians. In conclusion, (1) intraportal HTX is feasible, but portal hypertension limits the maximum amount of hepatocytes that can be infused in one HTX; (2) BrdU labeling is an attractive method for the detection of transplanted hepatocytes in the recipient liver; and (3) after two consecutive hepatocyte transplantations, a temporary correction of the purine metabolism was accomplished in the dalmatian dog.

Evidence of metabolic activity of adult and fetal rat hepatocytes transplanted into solid supports.

This study was undertaken to assess the metabolic effect of fetal and adult hepatocyte transplantation in the Gunn rat, genetically incapable of bilirubin conjugation. A comparison was made between fetal and adult hepatocytes transplanted into the spleen, and those injected into polytetrafluoroethylene (PTFE) solid supports that had previously been implanted intraperitoneally. Between 4 and 12 weeks after intrasplenic transplantation of adult liver cells, serum bilirubin was significantly decreased when compared with control animals (39.6 +/- 5.6%; P less than 0.01 vs. controls). Intrasplenic transplantation of fetal hepatocytes resulted in a maximal decrease of 33.2 +/- 9.1% at 8 weeks postoperatively (P less than 0.02 vs. controls). Similar declines of serum bilirubin levels were found after transplantation of adult or fetal liver cells into the solid supports. At 12 weeks after transplantation, bilirubin conjugates were detectable in the bile of all animals that underwent intrasplenic hepatocyte transplantation and in 60% of those that underwent the solid support procedure, whereas none could be detected in control animals. Histological evidence of surviving cells was obtained in all but one animal at 12 weeks, and confirmed at 12 months postoperatively. It is concluded that the PTFE solid support technique offers an attractive alternative to the intrasplenic route, and that both fetal and adult hepatocytes, transplanted in either way still exert their conjugating activity after 12 weeks.

Calibration of Pd-porphyrin phosphorescence for oxygen concentration measurements in vivo.

Quantitative measurement of oxygen concentrations in the microvasculature is of prime importance in issues related to oxygen transport to tissue. The introduction of the quenching of the Pd-porphyrin phosphorescence as oxygen sensor in vivo by Wilson et al. (J. Appl. Physiol. 74: 580-589, 1993) has provided in this context a major advance in this area of research. For in vivo application, the dye is coupled to albumin to restrict the dye to the circulation and to measure oxygen in the physiological range. In this study a phosphorimeter with a gated photomultiplier is presented and validated. Furthermore, a nonlinear-fit method using the Marquardt-Levenberg algorithm is used to calculate the decay time. With this new phosphorimeter, calibration measurements were performed to investigate the effects of pH, temperature, and diffusivity. The results present a preparation method for albumin coupling of the dye that eliminates the pH dependency of the quenching kinetics. Furthermore, the decreased oxygen diffusivity of serum was compared with that of water, and it was shown that calibration constants measured in water can be extrapolated to serum.

Nutrition in patients with cystic fibrosis: a European Consensus.

This document is the result of an European Consensus conference which took place in Artimino, Tuscany, Italy, in March 2001 involving 33 experts on nutrition in patients with cystic fibrosis, organised by the European Cystic Fibrosis Society, and sponsored by Axcan-Scandipharm, Baxter, Dr Falk Pharma, Fresenius, Nutricia, SHS International, Solvay Pharmaceuticals (major sponsor). The purpose of the conference was to develop a consensus document on nutrition in patients with cystic fibrosis based on current evidence.

Bleeding as presenting symptom of cholestasis.

Four infants with conjugated hyperbilirubinemia who were brought for treatment primarily because of a hemorrhage are reported. Underlying disorders included extrahepatic biliary atresia, choledochal cysts, and alpha 1-antitrypsin deficiency. Prodromal signs of disturbed coagulation and diminished bile excretion were not recognized. The increased bleeding tendency was probably caused by vitamin K deficiency, resulting from a combination of cholestasis-induced fat malabsorption, absence of vitamin K supplementation after birth, and low vitamin K intake as a result of breast feeding.

Present and future treatment modalities for gastrointestinal diseases in cystic fibrosis.

In recent years knowledge of the basic defect of CF has increased enormously. Many new drugs and treatment strategies are being introduced in the clinic. Nevertheless, there are a number of unsolved problems in the treatment of malabsorption and malnutrition. In spite of innovative technical and pharmacological improvement of pancreatic enzyme preparations maldigestion is still a problem. Better enzymes and coatings are needed. The integrated action of enzymatic digestion, intestinal motility and absorption is not under control. The role of malnutrition in the development of complications and in the outcome of the disease is still under discussion. The importance of a high energy intake is now generally accepted, but the question is how to achieve this. Tube feeding, endoscopic gastrostomy and the use of diets with a high energy content are becoming more popular. In CF the relationship between gastro-oesophageal reflux and lung complications is not well understood, but GER is frequently recognized. In the absence of CF GER is also associated with a number of pulmonary and upper airway diseases. The incidence of liver fibrosis and cholestatic liver disease is increasing with age. The problem is how to identify the patients at risk. The use of choleretic drugs has shown promising results in preliminary studies. Gene therapy in pancreatic and gastrointestinal pathology will be restricted to the liver. The biliary tract could be an interesting target, if patients at risk can be identified. In conclusion, new drugs and new strategies are necessary for the future implementation of the results of new insights in CF.

Relationship between intestinal function and chloride secretion in patients with cystic fibrosis.

Cystic fibrosis (CF) is the most frequent inheritable disease with a lethal course. One of the major problems of the disease is malabsorption and malnutrition, due to pancreatic insufficiency which is already present at birth in more than 85% of the patients. Characteristically the mucoid secretion products of the epithelial tissues in lung, pancreas, liver and intestine have a high viscosity. The pathophysiology is characterized by obstruction of these organs with secondary damage and finally destruction. For a long period intestinal obstruction syndromes in CF were ascribed only to the pancreatic insufficiency. Malabsorption is not only caused by enzyme deficiency but is also related to transport processes to the surface of the enterocytes. This indicates that the intestinal disorders in CF are partly the result of mucoid plugging and not only of pancreatic insufficiency. Recently in vitro studies have shown a blockade of secretion through chloride channels in the mucosal membrane of CF tissues. In vivo measurements of chloride fluxes in the rectum showed a disturbed regulation in CF patients. The high viscosity of the mucus and plugging is directly related to the diminished chloride secretion. So it is postulated that the abnormal chloride secretion is responsible for the intestinal obstruction and partially also for the malabsorption.

Chloride transport in the cystic fibrosis enterocyte.

Molecular mechanisms of intestinal chloride channel regulation and potential abnormalities in electrogenic chloride secretion in intestinal epithelium from cystic fibrosis (CF) patients were investigated by a combination of Ussing chamber, vesicle transport and off-cell patch-clamp analysis. Short circuit current (Isc) measurements in normal and CF rectal biopsies provided evidence for i) a defect in the cAMP-provoked activation of chloride secretion and a (hyper)expression of cAMP-dependent potassium secretion in all CF patients examined (n = 11); ii) a defect in the carbachol-provoked chloride secretion and a (hyper)expression of carbachol-induced potassium secretion in 6/11 patients; iii) a residual (but still impaired) carbachol-induced chloride secretion in 5/11 CF patients (including 2 sibs). The latter class of CF patients appeared to consist genetically of compound heterozygotes for the major delta-F508 deletion, suggesting a correlation between the nature of the mutation in the CF gene and the severity of the chloride secretory defect in CF intestine. In our search for a regulatory function of GTP-binding (G-) proteins detected previously in the luminal membrane of rat and human intestinal epithelial cells, evidence was found for the presence of a GTP[S]-activatable- and GDP[S]-inhibitable chloride conductance in the apical membrane of rat enterocytes and human colonocytes. In excised patches of human colonocyt membranes, this G-proteine-sensitive chloride conductance was identified further as a novel type of chloride channel (20pS; inwardly rectifying) that was different from the 33pS outwardly rectifying chloride channel activatable by cAMP-dependent proteinkinase (PK-A) and voltage depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequential changes in relative liver function assessed by 99mTc-HIDA scintigraphy after auxiliary heterotopic liver transplantation in dogs.

Auxiliary heterotopic liver transplantation (HLT) was used to achieve functional repair in a dog model with an inborn error of metabolism. For the interpretation of the results, information on separate liver function is essential when a normal host liver is also present. We developed a radionuclear method to quantitate the relative contribution of each liver to the total uptake of intravenously (IV) injected 99mTc-HIDA. The HLT was performed between 20 mismatched pairs of dogs from two different strains. Four surgical procedures were used. After autopsy the outcome of the premortem HIDA-scan was compared with the wet weight of the graft and the host liver. A good linear correlation was noted between the relative contribution of the uptake and weight of the graft to the total HIDA uptake and total liver weight. Therefore, the relative contribution of an auxiliary heterotopic liver graft to the total liver function can be quantitated with a 99mTc-HIDA scan. With this technique, changes in relative function after an HLT under various flow conditions can be sequentially followed.

Directing portal flow is essential for graft survival in auxiliary partial heterotopic liver transplantation in the dog.

BACKGROUND/PURPOSE: Auxiliary liver transplantation is an attractive alternative for orthotopic liver transplantation in patients with certain inborn errors of metabolism of the liver in which complete resection of the liver is unnecessary or even contraindicated. Because in these diseases portal hypertension is mostly absent, finding a balance in portal blood distribution between native liver and graft is complicated. The objective of this study was to investigate requirements for long-term (180 days) graft survival in auxiliary partial heterotopic liver transplantation (APHLT) in a dog model. METHODS: A metabolic defect was corrected in 26 dalmation dogs with a 60% beagle heterotopic auxiliary liver graft. Four groups of different portal inflow were studied. In the ligation group the portal vein to the host liver was ligated. In the split-flow group graft and host liver received separate portal inflow. In the banding group the distribution of the portal flow was regulated with an adjustable strapband and in the free-flow group the portal blood was allowed to flow randomly to host or graft liver. RESULTS: Metabolic correction increased in all groups after transplantation from 0.19 +/- 0.02 to 0.70 +/- 0.05 (P< .0001) but remained significantly better in the ligation and split-flow groups (graft survival, 135 +/- 27 and 144 +/- 31 days). In the banding group metabolic correction decreased significantly after 70 days, and although the grafts kept some function for 155 +/- 14 days, in 4 of 6 dogs portal thrombosis was found. In the free-flow group, competition for the portal blood led to reduced correction within 12 days and total loss of function in 96 +/- 14 days. Graft function also was assessed with technetium (Tc) 99m dimethyl-iminodiacetic acid uptake. A good linear association between HIDA uptake and metabolic correction was observed (r = 0.74; P < .0005). Grafts that contributed more than 15% to the total uptake of HIDA showed biochemical correction. This indicates a critical graft mass of about 15% to 20% of the hepatocyte volume to correct this metabolic defect. CONCLUSION: Auxiliary partial heterotopic liver transplantation can be a valuable alternative treatment for inborn errors of hepatic metabolism if the native liver and the graft receive separate portal blood inflow.

Gastroesophageal reflux and ENT disorders in childhood.

Among controversies in pediatric otorhinolaryngology, the role of gastroesophageal reflux (GER) in inflammatory disorders of the upper airway remains of major concern. A laryngeal involvement by GER was demonstrated in adults and a correlation with GER has been found in pediatric populations with recurrent croup. However, although considered statistically significant, these results concern a few patients only and are inconclusive for a causal relationship. In addition, pH monitoring, often considered as the gold standard for the diagnosis of GER disease, has failed in giving normal values in ENT disorders. Eventually, upper pharyngeal and nasal involvements by GER and GER-related otitis media or otalgia have been suggested by some authors. In the 6th International Congress on Pediatric Otolaryngology, the Symposium on GER was designed to help physicians in improving their knowledge of the data from the literature and their understanding of the involved mechanisms. Bearing in mind the potential severity of GER disease, the audience also heard and debated the most up-to-date methods of assessing GER and treating it in patients with possibly related otorhinolaryngological symptoms. Here is the summary of this symposium.

Bile acid clearance and biocompatibility of XAD-4 haemoperfusion.

The clearance of bile acids from human blood or human albumin solutions obtained by perfusion through 100 g XAD-4 at 100 ml/min was (in ml/min): 21 for taurocholic acid, 3 for taurochenodeoxycholic acid, 18 for glycholic acid and 2 for glychenodeoxycholic acid. Saturation effects were absent up to 7 mumole bile acid bound per gram XAD-4. Haemoperfusion (100 g XAD-4, 100 ml/min) of cholestatic dogs resulted in the removal of up to 400 mumole bile acid in 3 hours. The calculated amount of bile acid stored in tissue depots was large with respect to the amount present in the circulation. A steady state between the mobilization of the tissue pool of bile acids and the removal of bile acids from the blood was established during the perfusion. Measurements of electrolytes enzyme activities and cellular elements showed severe losses of thrombocytes and leucocytes only. Contact with XAD-4 was the cause of the platelet loss where as omission of the resin from the perfusion system did not effect the leucocyte loss. The thrombocyte loss was reduced by the addition of citrate. Differentiation of the leucocytes showed that primarily the segmental granulocytes were sequestrated.

[Hepatitis B in children in 4 university centers in The Netherlands]. / Hepatitis B bij kinderen in vier universitaire centra in Nederland.

OBJECTIVE: To evaluate the prevalence and the natural course of hepatitis B infection in children. DESIGN: Retrospective longitudinal. SETTING: Four university pediatric centres. METHOD: To explore the possibility of starting a trial with interferon alpha, data of viral and biochemical tests and biopsies of children younger than 16 years were studied. RESULTS: In a period of 10 years (1980-1990) 145 patients, of whom 74% were not of original Dutch descent, were found positive for HBsAg. The data of 142 patients could be analysed. Seroconversion was seen in 27 patients and 42 were already anti-HBe positive at the time of presentation. Chronic hepatitis, representing the category which could benefit from interferon alpha treatment, was found in 24 patients. Severe complications of the hepatitis were found in 4% of the children, including hepatocellular carcinoma and cirrhosis. Follow-up was insufficient so the seroconversion rate could only be estimated at 12% for the first year following the diagnosis. CONCLUSION: As a result of this study the authors present a proposal for a therapeutic trial with interferon alpha. This is a national protocol under the auspices of the section for pediatric gastroenterology of the Nederlandse Vereniging voor Kindergeneeskunde (Netherlands Pediatric Association).

[An infant with AIDS]. / Een zuigeling met AIDS.

A four-month-old girl was hospitalized with pneumococcal sepsis from which she recovered. Subsequently she developed various other infectious diseases, including chronic diarrhoea caused by Cryptosporidium. After a period with neurological symptoms, later sagittal sinus thrombosis and cerebral atrophy, she died at age 13 months. It was found that the child suffered from AIDS. The mother was seropositive and the virus had probably been transmitted via the placenta. Rapid recognition of infants and young children with AIDS is necessary, for in the near future more cases of this disease will occur. Antiviral treatment may bring about improvement in children as well.

New insights into the pathogenesis of cystic fibrosis.

Cystic fibrosis (CF) is the most frequent inheritable disease with a lethal course during childhood. The characteristic high viscosity of the mucoid secretion products in the lungs, pancreas, and gut cause plugging and secondary damage of these organs. In the past 20 years effective treatment of intestinal obstruction in the neonatal period and the infections of the lungs has improved the prognosis significantly. Many patients will reach adulthood in the near future. In the past 10 years new insights into the cause of the disease changed diagnostic procedures and, it is to be hoped, soon also treatment. The first development was the estimation of brush-border enzymes in amniotic fluid. With this method prenatal diagnosis is possible in the 17th-18th week of pregnancy. The recent discovery of the gene on chromosome 7 and its structure is the most important breakthrough. At the same time the process of Cl- transport across the mucosal membrane of many types of epithelium was subject to investigation by several laboratories. We have studied the transport of ions in the small and large intestines of CF patients. The effect of all three types of intracellular signal transfer is abnormal, although the second messengers themselves (cAMP, cGMP, and Ca2+) are present. Evidence is found for K+ instead of Cl- secretion after addition of secretagogues.