Biomedical subjects

J Fichtner

Publications and source records attributed to J Fichtner.

51 records · Page 3Linked to original sources

PubMed1994

Ultrafast contrast enhanced magnetic resonance imaging of congenital hydronephrosis in a rat model.

Since new ultrafast magnetic resonance imaging (MRI) might offer unique advantages for evaluating renal blood flow, anatomy and urinary excretion, we used this technique to characterize a rat model with congenital partial ureteropelvic junction obstruction. MRI of 9 rats from an inbred colony with unilateral congenital (nonsurgical) hydronephrosis was compared with the contralateral nonhydronephrotic kidney serving as control. Our new imaging technique consisted of a 1-minute ultrafast gradient recalled imaging sequence during the first minute (64 images per imaging time 960 milliseconds) after contrast bolus injection with gadolinium-diethylenetriaminepentaacetic acid for assessment of renal blood flow followed by a 30-minute period with image acquisition every 30 seconds to study contrast distribution and excretion. Signal intensities were analyzed continuously over selected, different regions of interest. Anatomic analysis of MRI noncontrast studies showed precise delineation of the hydronephrotic pelvis and corticomedullary junction. After contrast gadolinium-diethylenetriaminepentaacetic acid injection signal intensity from the region of interest from hydronephrotic kidneys differed from nonhydronephrotic kidneys by showing less cortical decrease, suggesting decreased blood flow, less medullary decrease and delayed contrast excretion. Clear contrast distribution among the cortex, medulla and collecting system allowed selective estimation of different regions of interest and excellent anatomic evaluation. Renal anatomy and renal pelvic pressures were confirmed after scans were completed. Ultrafast contrast enhanced MRI allows simultaneous assessment of renal morphology, blood flow and function. In hydronephrotic partially obstructed kidneys distinct flow and excretion patterns measured with contrast enhanced MRI allow differentiation between the obstructed and nonobstructed kidney on physiological rather than purely anatomic means. This imaging technique may provide a useful method of evaluating congenital hydronephrosis obviating the need for multiple different diagnostic procedures.

Animals↗

PubMed1993

Pediatric genitourinary tumors.

During the past two decades, highly effective multimodality therapy involving surgery, chemotherapy, and radiation has been developed through consecutive national and international study protocols for childhood genitourinary cancers with the model being Wilms' tumor. These studies represent a landmark achievement in the history of pediatric oncology and mark the success of multi-institutional studies. With the excellent survival rates that have been established, current interest is now directed toward examining survivors for long-term treatment complications and minimizing the side effects while preserving treatment efficacy. In addition, new developments in the molecular biology of Wilms' tumor have made this neoplasm a model for understanding the molecular and genetic aspects of tumorigenesis. This article reviews some of the publications from 1992 on pediatric genitourinary tumors.

Child↗

PubMed1993

Ureterovesicovaginal fistulas.

Our experience with urogenital fistulas are reviewed and three instances of complex ureterovesicovaginal fistulas, which can be mistaken for pure vesicovaginal fistulas because of diagnostic difficulties, are presented. If the ureterovaginal component of these fistulas is overlooked intraoperatively, urinary leakage will persist despite otherwise successful closure of the vesicovaginal component of the fistula. Because of the involvement of the terminal ureter in the fistulous system, operative therapy must combine the closure of the vesicovaginal fistula with reimplantation of the ureter into the bladder and interposition of omentum or a peritoneal patch between the bladder and vagina. Diagnosis and therapy are illustrated by patient reports and literature review.

Female↗

PubMed1993

Primary vesicoureteral reflux in children under one year of age: the case for conservative management?

The natural course of reflux nephropathy was evaluated in children who have been diagnosed for primary vesicoureteral reflux already during the first year of life. The retrospective study in 103 patients (163 refluxive renal units) revealed that 80% of all children in this age group were boys. Scarring at the time of diagnosis was evident in 29% of the cases, compared to a rate of 20% in our whole reflux population. New scarring occurred in 17 patients (18%): 63% of the children had high grade refluxes (IV and V). The rate of spontaneous resolutions was 61% and even grade V refluxes showed a spontaneous cessation in 40% of the cases. These data indicate a high overall spontaneous cure rate in young children, but underline the importance of selecting those patients with already scarred kidneys and recurrent urinary tract infections for an early operation since they are not likely to show a spontaneous resolution of reflux.

Adolescent↗

PubMed1992

[Chromosome abnormalities in hypospadias? An analysis of 131 patients].

We performed chromosome studies in 131 patients presenting with hypospadias, with the aim of detecting any causal connections between chromosomal abnormalities and the induction of hypospadias. Autosomal abnormalities were revealed in 6 and sex chromosomal abnormalities in 10 patients. Although a significant causal relationship between the occurrence of hypospadias and chromosomal abnormalities was seen in this study in only two cases of mixed gonadal dysgenesis (45,X/46,XY and streak gonad), the high incidence of chromosomal abnormalities observed (12.2%) seems noteworthy compared with the incidence of only 0.61% in the normal male population.

Adolescent↗

PubMed1992

[Prognostic parameters of scar progression, new scar formation and maturation in primary vesico-ureteral-renal reflux].

We analysed the data recorded for 901 children (1357 kidneys) treated for primary vesicoureteral reflux between 1973 and 1988 at our institution. The retrospective study showed a rate of 7.3% for new renal scarring and progression; analysis by reflux grade revealed progression and new scarring in reflux, 10.9% of cases with grade IV and 16.5% of cases with grade V whereas low grades (I and II) were followed by no scarring at all. A close correlation of new scarring with urinary tract infection and bladder function was demonstrated. Spontaneous resolution of reflux was observed in 33.6% of all patients and in only 2.6% of patients with grade V reflux, as against a 85.5% resolution rate in patients with grade I or II reflux. A different sex distribution was revealed in the age group under 1 year, in which 80% of the patients were boys and the resolution rate was higher than in any other age group.

Adolescent↗

PubMed1970