Biomedical subjects

R Keil

Publications and source records attributed to R Keil.

At least 19 recordsLinked to original sources

PubMed2002

[Emergency ERCP].

Although the effectivity of an urgent ERCP was confirmed, some aspects relating to this method are still discussed. Timing of this procedure has not been established yet. Whereas there is no doubt about indication with decompression of the common bile duct in acute cholangitis, views on the effectiveness of examination incl. papillotomy in case of acute pancreatitis are not uniform. The authors demonstrate a group of 538 patients who had urgent ERCP within the last three years with a successful cannulation rate of 93%. The experience of large centres is confirmed as the great efficiency and effectivity of this procedure when the standard conditions and processes are respected.

Acute Disease↗

PubMed2002

[Gastric carcinoma--the sentinel node concept: initial experience].

Gastric cancer is a serious malignant disease. The only hope for long time survival is radical surgery. It consists of gastrectomy and also resection of adjacent lymphatic tissues. The extent of lymphadenectomy is one of the currently discussed questions. D2 lymphadenectomy is now becoming standard also in our country. This extensive procedure can be quite difficult and needs an experienced surgeon. It is also connected with prolonged operation time and higher costs. According to some authors, this procedure is also associated with a higher morbidity. The question, whether D2 lymphadenectomy should be performed, could be answered by the sentinel node concept, which is the topic of our work.

Adenocarcinoma↗

PubMed2001

Cervico-thoracic disc protrusions in controlled compressed-air diving: clinical and MRI findings.

Prevalence of cervical and thoracic disc protrusions was investigated by MRI in 24 military long-term compressed-air divers and 24 controls. A total of 26 disc protrusions (17 cervical disc protrusions) were detected in 58% of the divers whereas 18 protrusions were detected in 38 % of the controls (13 disc cervical protrusions). There was no significant difference between groups and no correlation with the diving experience. Neurological examination revealed no clinical abnormalities. In contrast to a recent study, our results suggest that long-term divers are at no increased risk for accumulating spinal disc protrusions or intramedullary abnormalities.

Adult↗

PubMed2001

Nonoperative therapy of the posttraumatic biliary fistula in adolescents.

Posttraumatic biliary fistula is one of the complications of major hepatic injury. Conventional treatment has consisted of surgical intervention with hepatic debridement, ductal repair, and controlled drainage. The authors present two boys, 15 and 17 years of age, with biliary fistulas resulting after major hepatic injury. Biliary fistulas were successfully treated nonoperatively with sphincterotomy and endoscopically inserted small-caliber stents. The duration of time between stent placement and closure of the fistulas were 2 and 8 days, respectively.2.5 years after injury, both patients are without problems. These cases demonstrate the effectiveness of nonoperative management of traumatic biliary fistulas in adolescents.

Adolescent↗

PubMed2001

Idiopathic fibrosing pancreatitis presenting with obstructive jaundice in a child.

Idiopathic fibrosing pancreatitis (IFP) is a rare cause of obstructive jaundice in children. The obstruction is caused by circumferential compression of the intrapancreatic portion of the common bile duct (CBD). Various forms of biliary decompression, including surgical sphincteroplasty, choledochoduodenostomy, and Roux-en-Y choledochojejunostomy are employed as a treatment. We report a 14-year-old boy with IFP who was successfully treated by a temporary drainage of compressed CBD with the help of a stent placed by endoscopic retrograde cholangiopancreatography (ERCP). The diagnosis of IFP was confirmed histologically after open surgery. The patient remains well after 3.5 years of follow-up with no evidence of pancreatic insufficiency. This report offers an additional case of IFP causing obstructive jaundice treated by temporary internal drainage of CBD, which is safer and less invasive than biliodigestive surgical decompression.

Adolescent↗

PubMed2001

Biodistribution and radiation dosimetry of the dopamine transporter ligand.

UNLABELLED: 18F-labeled 2 beta-carbomethoxy-3beta-(4-chlorophenyl)-8-(-2-fluoroethyl)nortropane ([18F]FECNT) is a recently developed dopamine transporter ligand with potential applications in patients with Parkinson's disease and cocaine addiction. METHODS: Estimates of the effective dose equivalent and doses for specific organs were made using biodistribution data from 16 Sprague-Dawley rats and nine rhesus monkeys. PET images from two rhesus monkeys were used to calculate the residence time for the basal ganglia. The computer program MIRDOSE3 was used to calculate the dosimetry according to the methodology recommended by MIRD. RESULTS: The basal ganglia were the targeted tissues receiving the highest dose, 0.11 mGy/MBq (0.39 rad/mCi). The effective dose equivalent was 0.018 mSv/MBq (0.065 rem/mCi), and the effective dose was 0.016 mSv/MBq (0.058 rem/mCi). CONCLUSION: Our data show that a 185-MBq (5-mCi) injection of [18F]FECNT leads to an estimated effective dose of 3 mSv (0.3 rem) and an estimated dose to the target organ or tissue of 19.4 mGy (1.93 rad).

Animals↗

PubMed2000

Neurologic outcome of controlled compressed-air diving.

The authors compared the neurologic, neuropsychological, and neuroradiologic status of military compressed-air divers without a history of neurologic decompression illness and controls. No gross differences in the neuropsychometric test results or abnormal neurologic findings were found. There was no correlation between test results, diving experience, and number and size of cerebral MRI lesions. Prevalence of cerebral lesions was not increased in divers. These results suggest that there are no long-term CNS sequelae in military divers if diving is performed under controlled conditions.

Adult↗

PubMed2000

Synthesis, biodistribution, and primate imaging of fluorine-18 labeled 2beta-carbo-1'-fluoro-2-propoxy-3beta-(4-chlorophenyl)tr opanes. Ligands for the imaging of dopamine transporters by positron emission tomography.

2beta-(R)-Carbo-1-fluoro-2-propoxy-3beta-(4-chlorophenyl) tro pane ((R)-FIPCT, R-6) and 2beta-(S)-carbo-1-fluoro-2-propoxy-3beta-(4-chlorophenyl) tro pane ((S)-FIPCT, S-6) were prepared and evaluated in vitro and in vivo for dopamine transporter (DAT) selectivity and specificity. High specific activity [(18)F](R)-FIPCT and [(18)F](S)-FIPCT were synthesized in 5% radiochemical yield (decay-corrected to end of bombardment (EOB)) by preparation of the precursors 2beta-carbo-R-1-mesyloxy-2-propoxy-3beta-(4-chlorop hen yl)tropane (R-12) and 2beta-carbo-S-1-mesyloxy-2-propoxy-3beta-(4-chlorop hen yl)tropane (S-12) followed by treatment with no carrier-added potassium[(18)F]fluoride and kyrptofix K222 in acetonitrile. Competition binding in cells stably expressing the transfected human DAT and serotonin transporter (SERT) labeled by [(3)H]WIN 35428 and [(3)H]citalopram, respectively, demonstrated the following order of DAT affinity (K(i) in nM): GBR 12909 (0.36) > CIT (0.48) > (S)-FIPCT (0.67) >> (R)-FIPCT (3.2). The affinity of (S)-FIPCT and (R)-FIPCT for SERT was 127- and 20-fold lower, respectively, than for DAT. In vivo biodistribution studies were performed in male rats and demonstrated that the brain uptake of [(18)F](R)-FIPCT and [(18)F](S)-FIPCT were selective and specific for DAT rich regions (caudate and putamen). PET brain imaging studies in monkeys demonstrated high [(18)F](R)-FIPCT and [(18)F](S)-FIPCT uptake in the caudate and putamen which resulted in caudate-to-cerebellum and putamen-to-cerebellum ratios of 2.5-3.5 at 115 min. [(18)F](R)-FIPCT uptake in the caudate/putamen achieved transient equilibrium at 75 min. In an imaging experiment with [(18)F](S)-FIPCT in a rhesus monkey with its left hemisphere lesioned with MPTP, radioactivity was reduced to background in the caudate and putamen of the lesioned hemisphere. The high specific activity one-step radiolabeling preparation and high specificity and selectivity of [(18)F](R)-FIPCT and [(18)F](S)-FIPCT for DAT indicate [(18)F](R)-FIPCT and [(18)F](S)-FIPCT are potential radioligands for mapping brain DAT in humans using PET.

Animals↗

PubMed2000

18F-labeled FECNT: a selective radioligand for PET imaging of brain dopamine transporters.

Fluorine-18 labeled 2beta-carbomethoxy-3beta-(4-chlorophenyl)-8-(2-fluoroethyl)nort ropane (FECNT) was synthesized in the development of a dopamine transporter (DAT) imaging ligand for positron emission tomography (PET). The methods of radiolabeling and ligand synthesis of FECNT, and the results of the in vitro characterization and in vivo tissue distribution in rats and in vivo PET imaging in rhesus monkeys of [18F]FECNT are described. Fluorine-18 was introduced into 2beta-carbomethoxy-3beta-(4-chlorophenyl)-8-(2-fluoroethyl)nort ropane (4) by preparation of 1-[18F]fluoro-2-tosyloxyethane (2) followed by alkylation of 2beta-carbomethoxy-3beta-(4-chlorophenyl)nortropane (3) in 21% radiochemical yield (decay corrected to end of bombardment [EOB]). Competition binding in cells stably expressing the transfected human DAT serotonin transporter (SERT) and norepinephrine transporter (NET) labeled by [3H]WIN 35428, [3H]citalopram, and [3H]nisoxetine, respectively, indicated the following order of DAT affinity: GBR 12909 > CIT >> 2beta-carbomethoxy-3beta-(4-chlorophenyl)-8-(3-fluoropropyl) nortropane (FPCT) > FECNT. The affinity of FECNT for SERT and NET was 25- and 156-fold lower, respectively, than for DAT. Blocking studies were performed in rats with a series of transporter-specific agents and demonstrated that the brain uptake of [18F]FECNT was selective and specific for DAT-rich regions. PET brain imaging studies in monkeys demonstrated high [18F]FECNT uptake in the caudate and putamen that resulted in caudate-to-cerebellum and putamen-to-cerebellum ratios of 10.5 at 60 min. [18F]FECNT uptake in the caudate/putamen peaked in less than 75 min and exhibited higher caudate- and putamen-to-cerebellum ratios at transient equilibrium than reported for 11C-WIN 35,428, [11C]CIT/RTI-55, or [18F]beta-CIT-FP. Analysis of monkey arterial plasma samples using high performance liquid chromatography determined that there was no detectable formation of lipophilic radiolabeled metabolites capable of entering the brain. In equilibrium displacement experiments with CIT in rhesus monkeys, radioactivity in the putamen was displaced with an average half-time of 10.2 min. These results indicate that [18F]FECNT is a radioligand that is superior to 11C-WIN 35,428, [11C]CIT/RTI-55, [18F]beta-CIT-FP, and [18F]FPCT for mapping brain DAT in humans using PET.

Animals↗

PubMed2000

[The short bowel syndrome].

The authors demonstrate on case-histories their experience with short-loop syndrome which develops after extensive resections of the small intestine. The clinical picture of the syndrome is characterized by diarrhoea, steatorrhoea, maldigestion and malabsorption with loss of body weight. Non-surgical treatment of the syndrome copies its different stages. The objective of conservative therapy is above all to preserve the nutritional integrity of the organism and gradual adaptation of the gut which will make eventually a change to oral intake possible. This adaptation takes 1 to 2 years. Last not least, treatment should eliminate the diarrhoea. The authors demonstrate on examples that properly conducted treatment prevented the development of malnutrition, contrary to another case where the sequelae of surgery were underestimated and the patient developed cachexia and pernicious anaemia.

Adult↗

PubMed1999

The endoscopic treatment of benign esophageal strictures by balloon dilatation.

Benign strictures of the esophagus are serious illnesses that have a great adverse effect on the quality of life of patients. There are several methods of treatment. In this study the endoscopical balloon dilatation technique was used. All dilatations were performed under analgosedation, and plastic balloons (6-25 mm) were used. Ninety dilatations were performed between 1995 and 1997. Twenty-two patients were diagnosed as having benign stenosis of the esophagus. We evaluated the effectiveness and the complication rate of the method. All patients except two showed immediate improvement: 59% were cured; 18% had at least one recurrence of the stenosis; 9% had improvement but treatment continues; 14% required other treatment. We encountered two cases with major complications, i.e. perforation. Balloon dilatation seems to be an effective and safe method for treatment of the benign esophageal strictures and is well tolerated by patients. Endoscopic control is sufficient, and radiographic control is not required. Randomized prospective studies are needed to establish the role of this method in comparison with other treatments.

Catheterization↗

PubMed1999

[Pancreatic head tumors--preoperative examination and reality].

The authors evaluated in a retrospective study the asset and accuracy of methods of preoperative diagnosis (ultrasonography, endoscopy, computed tomography and endoscopic sonography) in 47 patients with a preoperative finding of a tumour in the region of the head of the pancreas, where during the last three years a radical resection was performed. As compared with objective morphological findings of the resected tissues, endoscopic sonography proved the most sensitive and most reliable method for detection of focal changes in this area. The other compared methods also belong to the indispensible standard of preoperative diagnosis and in clear cases are sufficient for indication of surgery. Evaluation of nodal affection based on the finding of enlarged nodes during preoperative examination is very unreliable and should not influence decisions on indications for surgery.

Biopsy↗

PubMed1999

[Rupture of the pancreas in children--present trends in diagnosis and therapy].

Evaluation of pancreatic injuries is presented in the professional literature in retrospective studies and views on treatment vary. The authors evaluated also in a retrospective study a group of eight child patients with a serious injury of the pancreas. The patients were 3-13 years old and were hospitalized at the Clinic of Paediatric Surgery at the Faculty Hospital Motol in 1985-1999. The group is formed by patients with pancreatic injuries (according to the Japanese classification type II and III). The authors evaluate not only diagnostic but also therapeutic procedures. In the diagnosis they evaluate the ultrasonographic examination (USG) as the examination of first choice which however need not record the extent and severity of the pancreatic injury. Computing tomography (CT) and magnetic resonance (MRI) can make the original suspicion of injury more accurate, ERCP is an examination which reveals in particular type III injuries--i.e. those with affection of the pancreatic duct. Injured children where a serious pancreatic lesion was not diagnosed primarily, had to be subjected to repeated surgical revisions. All children in the presented group recovered, none of the patients died.

Adolescent↗

PubMed1998

[A new method of administering analgesic sedation before gastroscopy--a comparative study of 100 patients].

The authors administered to two groups (56 and 44) patients before gastroscopy analgosedation-5 mg diazepam and local anaesthesia of the throat. To the first group diazepam was administered by the i.v., to the second group by the sublingual route. The objective was to find out whether analgosedation is desirable from the patients aspect and whether the sublingual form of premedication is accepted by the patients. The authors found that 90% of the patients wish to have analgosedation and anaesthesia before the procedure. The sublingual form of administration was accepted by 89% of the patients.

Administration, Sublingual↗

PubMed1997

Central application of a nitric oxide donor activates heat defense in the rabbit.

In chronically instrumented, conscious rabbits at moderately warm ambient thermal conditions, infusion of the NO-donor SIN-1 into the anterio-ventral 3rd cerebral ventricle (1-2 microg/min per kg BW, 2-4 microl/min, 30 min) initiated a co-ordinated activation of autonomic heat loss mechanisms, as indicated by the rise in ear skin temperature and by increases in panting frequency and respiratory evaporative water loss, while oxygen consumption decreased slightly. The heat loss responses were similar to those attributed to NO in studies employing systemic application of NO-donors. Different from NO acting peripherally, which causes arterial hypotension and tachycardia, centrally acting NO induced arterial hypertension and bradycardia. The observation of the same heat loss responses despite opposing circulatory actions suggests that NO is specifically involved in thermoregulation as a central activator of heat defense mechanisms.

Animals↗

PubMed1997

[Vasculitis course of neuroborreliosis with thalamic infarct].

A-20-year-old man without vascular risk factors presented with paraesthesia of the left side of the body with acute onset. Cerebral magnetic resonance imaging showed an infarction in the right thalamus. Intra-arterial digital subtraction angiography revealed stenosis of the right thalamic vessels. Recent infection by Borrelia burgdorferi was demonstrated by typical findings in the cerebrospinal fluid: lymphocytic pleocytosis and intrathecal synthesis of borrelial-specific antibodies. The diagnosis of a borrelial-induced vasculitis with secondary thalamic infarction was made from these findings. After antibiotic treatment with cefrtriaxone, the patient was discharged without residual complaints.

Adult↗

PubMed1997

Nitric oxide increases cutaneous and respiratory heat dissipation in conscious rabbits.

The influence of systemic nitric oxide (NO) donor infusion and NO synthase inhibition on major thermoregulatory mechanisms was investigated under thermoneutral conditions (24 degrees C) in the conscious rabbit. Both low (25 nmol.min-1.kg-1) and high-dose (75 nmol.min-1.kg-1) infusion of the NO donors 3-morpholinosydnonimine-hydrochloride and S-nitroso-N-acetylpenicillamine augmented respiratory heat dissipation due to raised respiratory frequency (RF) and evaporative water loss (REWL). At the higher dose of NO donor, RF and REWL increased (from 107 +/- 16 to 156 +/- 19 breaths/min and from 7.12 +/- 0.97 to 11.29 +/- 1.29 mg.min-1.kg-1; P < 0.05), and, combined with a moderate rise in cutaneous heat dissipation (ear skin temperature increased from 29.03 +/- 1.76 to 33.29 +/- 2.71 degrees C; P < 0.05), deep body temperature was slightly reduced (-0.1 degrees C, P > 0.05) without a change in metabolic heat production. In contrast, blockade of endogenous NO synthesis induced a sustained rise in body temperature (0.2 degrees C, P < 0.05), concomitant with a reduction in both RF and REWL (from 131 +/- 11 to 94 +/- 12 breaths/min and from 10.86 +/- 1.14 to 8.70 +/- 0.88 mg.min-1.kg-1, P < 0.05), whereas metabolic heat production decreased slightly and cutaneous heat dissipation was minimally altered. The data indicate that, under thermoneutral conditions, systemically applied NO primarily influences body temperature in the conscious rabbit by modulating the rate of respiratory heat dissipation, whereas the roles of cutaneous heat dissipation and metabolic heat production are relatively minor.

Animals↗

PubMed1997

Vasodilation and glomerular binding of adrenomedullin in rabbit kidney are not CGRP receptor mediated.

The polypeptide adrenomedullin (ADM) was infused systemically to conscious rabbits to elucidate its actions on overall circulation and especially the renovascular bed and the formation and/or release of hormones important for body fluid homeostasis, including adrenocortical steroids. ADM lowered mean arterial pressure from 71.5 +/- 3.2 to 64.7 +/- 3.2 mmHg only at the highest dose of 25 pmol.min-1.kg-1 infused intravenously for 20 min and concomitantly induced tachycardia, possibly due to both baroreflex activation and direct cardiostimulatory effects. Renal blood flow (RBF) determined in rabbits chronically equipped with a perivascular ultrasonic flow probe increased from 55.4 +/- 2.1 to 67.4 +/- 2.7 and from 58.2 +/- 3.5 to 75.2 +/- 6.0 ml/min at ADM infusions of 5 and 25 pmol.min-1.kg-1, respectively. The elevation in RBF persisted even in the presence of the calcitonin gene-related peptide (CGRP1 receptor antagonist CGRP-(8-37). Of all osmoregulatory hormones tested, only corticosterone (Cort) plasma concentration increased in response to the highest ADM dose from 17.6 +/- 3.1 to 38.9 +/- 6.2 ng/ml, probably due to haroreflex activation. Subdepressor doses of ADM, however, caused a mild reduction in circulating Cort. Expression of functional high-affinity binding sites specific for ADM in vitro could be demonstrated for the renal artery and outer cortical glomeruli using 125I-labeled rat ADM as radioligand and determination of cellular adenosine 3',5'-cyclic monophosphate (cAMP) formation within the glomeruli. The ineffectiveness of CGRP-(8-37) to displace radiolabeled ADM from its binding sites, to inhibit ADM-induced glomerular cAMP formation, and to prevent ADM-induced renal vasodilation supports the hypothesis of ADM altering renal hemodynamics by interacting with ADM- and not CGRP-specific membrane receptors.

Adrenomedullin↗