Search PubMed⌕ Search

Biomedical subjects

J Scharf

Publications and source records attributed to J Scharf.

At least 19 recordsLinked to original sources
PubMed2005

Ascending arterial blood flow velocities during cardiac diastole in critical care patients--a characteristic flow pattern with a bad prognosis.

AIM: Pulsed Doppler ultrasound is a standard noninvasive investigation to measure the velocity and pulsatility of blood flow within the major intracranial and organ-supplying arteries in critical care patients. The normal arterial flow pattern in organ-supplying vessels is characterised by a systolic-diastolic forward flow which is caused by the aortic "Windkessel" function and the low peripheral resistance of the parenchymatous organs. A variety of well known pathological conditions may cause a change of the vascular characteristics within the perfused organs which are diagnosed by the typical changes of the flow pattern in the supplying arteries. In the cardiac diastole, however, there is always a slow decrease of the flow velocity which is terminated by the onset of the following systole. METHOD AND RESULTS: We report on 11 patients investigated by Doppler ultrasound during their stay in our intensive care unit. All these patients presented a markedly different flow pattern measured in their intra- and/or extracerebral vessels. This very distinctive flow pattern is characterised by a diastolic ascent of the arterial flow velocity and is caused by an excessively increased venous pressure within the draining veins of the affected organs. All patients died due to (multiple) organ failure. CONCLUSION: It is of major importance to be aware of the rare but very characteristic flow pattern described here because of the poor prognosis associated with it.

Arteries↗
PubMed2004

Thyrohyoid approach to cidofovir injection: a case study.

Various techniques for injection into the larynx have been well described, including transoral injection with indirect laryngoscopy or direct laryngoscopy and transcutaneous injection through the thyroid cartilage or cricothyroid membrane. We describe a case not amenable to these techniques, in which entry through the thyrohyoid membrane for injection of cidofovir was successfully performed with a thyrohyoid approach. This technique is described, and comparisons are made with currently available techniques.

Antineoplastic Agents↗
PubMed2001

Intravenous immunoglobulin therapy for resistant ocular Behçet's disease.

AIMS: The present report was aimed at finding out whether gammaglobulin could have a role in treating ocular Behçet's disease (BD) refractory to accepted medical therapy. METHODS: Six eyes of four patients with ocular BD refractory to steroids and cyclosporin A were treated with a course of intravenous gammaglobulin and followed up for their response to treatment. RESULTS: All six eyes of all four patients showed good response to gammaglobulin therapy. CONCLUSION: Gamma globulin may have a role in treating refractory ocular BD. A wide range of controlled studies with longer follow up is needed to substantiate this impression.

Adolescent↗
PubMed2000

Multiple retinal arteriolar occlusions associated with coexisting primary antiphospholipid syndrome and factor V Leiden mutation.

PURPOSE: To investigate a case of a young woman with both primary antiphospholipid syndrome and factor V Leiden mutation who developed multiple retinal arteriolar occlusions. METHOD: Case report of a 25-year-old woman with history and laboratory tests confirming the diagnosis of both primary antiphospholipid syndrome and factor V Leiden mutation who presented with blurred vision in both eyes. RESULTS: Multiple retinal arteriolar occlusions were observed in both of her eyes. The patient was treated first with heparin and then with warfarin. CONCLUSIONS: Primary antiphospholipid syndrome and factor V Leiden mutation, as well as other forms of thrombophilia, should be considered in the differential diagnosis of unexplained retinal vascular occlusions. The coexistence of several thrombophilic disorders may carry a particularly high risk for thrombotic manifestations.

Activated Protein C Resistance↗
PubMed1999

Assessment of hepatic perfusion in pigs by pharmacokinetic analysis of dynamic MR images.

The purpose of this study was to evaluate a new method based on magnetic resonance imaging for the characterization of hepatic perfusion. In nine pigs dynamic MRI was performed before and after partial occlusion of the portal vein. The pharmacokinetic analysis of the contrast enhancement resulted in a set of parameters (amplitude, A; perfusion rate, kp; elimination rate, kappa(e1); lag time, t(lag)) of which kp was expected to correlate with hepatic perfusion. Reference measurements were done with ultrasound flow-meters and with a thermal diffusion probe (TDP). MR perfusion rate kp significantly dropped under partial portal vein occlusion from an average of 11.3 to 4.9 min(-1) (P < 0.001), while the difference in amplitude A was not significant. The correlation between kp and the TDP measurement was r = 0.89 (P < 0.001). Pharmacokinetic analysis of MRI contrast enhancement provides a non-invasive assessment of hepatic perfusion.

Animals↗
PubMed1999

Reduced rates of catheter-associated infection by use of a new silver-impregnated central venous catheter.

A central venous catheter with a new form of silver impregnation of the internal and external surfaces was investigated for antimicrobial activity and tolerance in patients in a controlled comparative, prospective and randomized clinical study. Commercially available catheters with no antimicrobial activity were used as controls. One hundred sixty-five catheters were included in the final evaluation. All catheters were percutaneously inserted for the first time with a duration of > or = 5 days and a microbiological examination of the catheter tip. Catheter location (> 90% internal jugular vein), mean duration of catheterization (8-9 days), patients' age and diagnosis were comparable in both groups. Silver-impregnated catheter tips showed an incidence of colonization in 14.2/1000 catheter days and control catheters in 22.8/1000 catheter days. This represents a reduction of 37.7%. Catheter-associated infections were diagnosed in the silver group in 5.26/1000 catheter days and 18.34/1000 catheter days in the control group, indicating a reduction rate of 71.3% (P < 0.05, chi 2-test). No complications or side effects were documented in either group.

Anti-Infective Agents↗
PubMed1999

[Follow-up of TIPSS by color-coded duplex sonography using an ultrasonic signal enhancer. First results].

A study was performed to determine the visualization of the transjugular intrahepatic portosystemic stent shunt (TIPSS) and the detection of stenosis by the use of a capillary transversing signal enhancer. In 37 patients 37 colour-coded duplex sonographies were performed before and after intravenous injection of the ultrasound signal enhancer Levovist (Schering, Berlin). The examinations were evaluated using a four-category score. Special attention was paid to the detection of stenoses in the TIPSS. Transjugular portal venograms of the same day were used as gold standard. The use of Levovist provided better colour and flow signals for the portal vein end of the shunt in only 9 of 37 sonograms and for the hepatic vein end of the shunt in 37 of 39 sonograms. Eleven of 13 stenoses requiring reintervention in portal venography could be correctly identified with signal enhancer. Eleven of these 13 stenoses were located in the hepatic vein end of the shunt. Ultrasound signal enhancer can significantly improve the sonomorphological visualization especially of the hepatic vein end of TIPSS in colour-coded duplex sonography. Stenoses which usually occur in the hepatic vein end of the shunt may be better detected.

Constriction, Pathologic↗
PubMed1999

Pharmacokinetic and clinical evaluation of serious infections in premature and newborn infants under therapy with imipenem/cilastatin.

Efficacy and pharmacokinetic parameters of imipenem/cilastatin (I/C) were investigated in a retrospective evaluation in 104 premature and newborn infants. Patients enrolled in this investigation constituted a particularly high risk group with extreme prematurity, perinatal asphyxia and amnion infection as well as various malformations. In 15 of the 104 infants serum concentrations were measured for drug monitoring and determination of optimal total daily dosage. A total daily dose of 50 mg/kg birth weight for premature and newborn infants divided into two doses led to imipenem peak concentrations of 17.7 mg/l +/- 9.2 mg/l (range: 1.95-38.05) and trough levels were 2.35 mg/l +/-1.02 (range 2.34-10.88) in premature infants. Imipenem peak concentrations of 20.6 +/- 10.8 (range 3.94-32.3) and trough levels of 0.43 +/- 0.17 (range 0.16-0.94) were measured in newborns. The half-life of elimination was 3.3 h and 1.86 h, respectively. Six of the 104 treated patients died, five of them of causes unrelated to infection. Seizures occurred in 8.9% of patients during therapy with I/C compared with 5.8% of a large survey of premature and newborn infants in our intensive care unit (ICU). However, the severity of illness of these two groups cannot be compared. I/C can be expected to constitute effective therapy in premature and newborn infants with serious nosocomial infections even after failure of other broad spectrum antibiotics.

Bacteremia↗
PubMed1998

[Use of the ultrasound contrast medium levovist in after-care of liver transplant patients. Improved vascular imaging in color Doppler ultrasound].

INTRODUCTION: A study was carried out to determine whether an improvement in the detection of vascular signals in patients after orthotopic liver transplantation can be achieved by the use of ultrasound contrast medium in colour Doppler sonography. MATERIAL AND METHODS: In the early postoperative follow-up of liver transplant recipients, 31 colour Doppler sonograms were obtained in 21 patients before and after intravenous injection of the ultrasound contrast agent Levovist (Schering, Berlin). A grading score with four categories was used to evaluate the sonograms with special regard to the visibility of colour and flow signals in the hepatic artery and also in the portal vein and the hepatic veins. The arterial and portal venous signals were evaluated in the hepatic portal and in the left and right lobe. RESULTS: With contrast enhancement significantly better arterial signals were seen in 20 of 31 sonograms for the hepatic portal, in 22 for the right lobe and in 26 for the left lobe. Better portal vein signals were obtained in 17 of 31 examinations for the right lobe and in 16 for the left lobe; only little improvement was obtained for the main stem of the portal vein. For the hepatic veins there was no significant improvement. CONCLUSIONS: Early vascular complications after liver transplantation usually occur in the hepatic arteries. With the use of contrast-enhanced colour Doppler sonography, better detection of arterial and peripheral portal signals can be achieved; peripheral portal vein branches can be helpful in finding small arteries.

Adult↗
PubMed1998

[TIPSS: 10 years of clinical experience].

UNLABELLED: To demonstrate and document 10 years of clinical experience gathered by us with TIPSS and to discuss achievements, problems and outlook. MATERIAL AND METHODS: The analysis is based on the following parameters: portosystemic gradient; morphological delineation of the portal circulation; determination of the portal perfusion fraction (PPF) and the total liver perfusion (GLP); arterial flow changes; hepatic encephalopathy; incidence of restenotic shunt occlusion and recurrent variceal bleeding. RESULTS: Variceal filling was widely reduced by TIPSS, and significantly reduced portal liver perfusion as assessed morphologically and rheologically. However, there was an immediate onset of compensated liver perfusion by increased arterial inflow. Total liver perfusion did not change significantly. In TIPSS portal decompression was readily achieved, the portosystemic gradient dropping from an average of 24 mm Hg to 10.5 mm Hg. In our series we could not demonstrate an increased incidence of hepatic encephalopathy during the 30-day post-TIPSS period. Early mortality was 4% and early rebleeding rate 3%. The 12-month re-intervention rate based on an invasive portography follow-up protocol was 76%, and the 24-month re-intervention rate was 90%. The definite occlusion rate was below 5%. Beyond a follow-up time span of 24-months the necessity for re-intervention dropped significantly: less than one-third of our patients required some sort of re-intervention. CONCLUSION: The concept of TIPSS represents an individually calibrated H-shunt. The significant reduction of post-TIPSS portal perfusion appears to be compensated by increased arterial inflow. This is reflected by an invasive flow measurement results and by the clinical results. Lethality of TIPSS is low mostly as a result of a refined technique, careful patient selection, follow-up care and meticulous shunt surveillance.

Hepatic Encephalopathy↗
PubMed1998

Pseudolesions at T1-weighted gradient-echo imaging after administration of superparamagnetic iron oxide: comparison with portal perfusion abnormalities at CT during arterial portography.

PURPOSE: To compare specific findings at T1-weighted gradient-echo (GRE) magnetic resonance (MR) imaging performed after administration of superparamagnetic iron oxide (SPIO) with nontumorous regional portal perfusion abnormalities seen at computed tomography (CT) during arterial portography (CTAP). MATERIALS AND METHODS: The results of CTAP, MR imaging, and surgery were compared in 19 patients with liver metastases and five with benign liver tumors. MR imaging was performed by using turbo spin-echo (SE) sequences and a GRE sequence before and after infusion of SPIO. RESULTS: At CTAP, 34 nontumorous portal perfusion defects ("straight line sign," pseudolesions) were seen. After intravenous administration of SPIO, 18 nontumorous signal intensity differences were seen on T1-weighted GRE images in corresponding locations. No corresponding nontumorous signal intensity differences were seen on unenhanced MR images. The mean signal-to-noise ratio on the SPIO-enhanced GRE images was reduced from 26.3 to 16.6 in the areas of nontumorous signal intensity differences, whereas that in areas of normal portal perfusion (normal CTAP findings) was reduced to 10.2. CONCLUSION: Impaired portal perfusion decreased the uptake of SPIO in histopathologically normal regions of liver parenchyma. Resultant differences in signal intensity were better visualized on GRE than on turbo SE images.

Adolescent↗
PubMed1998

[Experimental evaluation of dynamic MRI for quantifying liver perfusion].

Gadolinium-DTPA enhanced dynamic MR imaging is a new method for the quantification of portal bloodflow and liver perfusion. In this study we evaluated the validity of this method comparing it with thermodiffusion and dopplerflowmetry in pigs. We found a significant correlation of tissue perfusion between dMRI and thermodiffusion and of portal bloodflow between dMRI and dopplerflowmetry. Partial occlusion of the portal vene was accurately detected by dMRI. Dynamic MRI could become a valuable diagnostic method for the quantification of liver perfusion.

Animals↗
PubMed1998

Severe pulmonary hypertension in a neonate caused by premature closure of the ductus arteriosus following maternal treatment with diclofenac: a case report.

The administration of non-steroidal antiinflammatory drugs (NSAID) has occasionally been related to fetal and neonatal cardiopulmonary, gastrointestinal, cerebral and renal complications. This report describes a term newborn with severe persistent pulmonary hypertension due to premature closure of the ductus arteriosus following a 5 day maternal treatment with diclofenac two weeks before delivery. Pulmonary hypertension only responded to unusually high doses of inhaled NO. The treatment was necessary for 22 days suggesting structural alteration of pulmonary vasculature. The child recovered, but tricuspid regurgitation persisted, presumably because of irreversible ischemic damage of one papillary muscle. This is the first reported case of persistent pulmonary hypertension of the newborn (PPHN) in association with maternal diclofenac treatment and represents a most severe form of PPHN induced by NSAID.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

Intermittent administration of furosemide versus continuous infusion in the postoperative management of children following open heart surgery.

OBJECTIVE: To compare the amount of furosemide needed to fulfil defined criteria for renal output if given intermittently or as a continuous infusion and to compare the effect of these two regimens on hemodynamic variables and urine electrolyte concentrations. DESIGN: Prospective randomized study of postoperative hemodynamically stable pediatric cardiac patients. The patients were given furosemide according to the urine output, either as an intermittent bolus injection or as a continuous infusion. SETTING: Pediatric intensive care unit in a university hospital. PATIENTS: The patients were randomly assigned before admission to either the intermittent i.v. or the continuous furosemide i.v. infusion group. MEASUREMENTS AND RESULTS: Demographic and hemodynamic data were recorded for a maximum of 72 h, as were furosemide dose, urine output, and fluid and inotropic drug requirements. Forty-six patients completed the study. Maximal hourly urine output was significantly higher in the intermittent group. A significantly lower dose of furosemide in the intermittent group produced the same 24-h urine volume as in the continuous infusion group. CONCLUSIONS: Intermittent furosemide administration may be recommended in hemodynamically stable postoperative pediatric cardiac patients because of less drug requirement. However, the high maximal urine output may cause hemodynamic problems in patients who depend on high inotropic support.

Child, Preschool↗
PubMed1997

Continuous plasma resin perfusion for detoxification of methotrexate.

UNLABELLED: Acute renal failure is a rare but very severe side-effect of methotrexate (MTX) treatment requiring extracorporeal detoxification. A new detoxification regime, consisting of a haemodiafiltration (HDF) and continuous plasma resin perfusion (PRP) over anion exchange resin column with high affinity for MTX, was used for treatment of MTX-induced acute renal failure in a 2-year-old boy with medulloblastoma. More than 99% of MTX was removed from plasma by perfusion over the resin column resulting in a marked decrease of MTX plasma half-life. No haematological complications occurred. CONCLUSION: The use of PRP alone or in combination with HDF is a new and effective treatment strategy for extracorporeal detoxification of MTX.

Acute Kidney Injury↗
PubMed1997

Retinal arterial occlusion in a child with factor V Leiden and thermolabile methylene tetrahydrofolate reductase mutations.

PURPOSE: To analyze the potential cause of retinal arterial occlusion in a 9-year-old child. METHODS: Case report. Antithrombin III, protein C, free protein S, activated protein C resistance, and antiphospholipid antibodies in plasma were determined. Determination of factor V R506Q (Leiden mutation), thermolabile methylene tetrahydrofolate reductase by polymerase chain reaction, and restriction enzyme analysis were performed. RESULTS: The patient was found to be heterozygous for factor V R506Q (Leiden mutation) and homozygous for thermolabile methylene tetrahydrofolate reductase. CONCLUSION: Coexistence of two mild hereditary thrombophilic states may result in severe thrombotic manifestations in young people.

Child↗