The role of MR imaging for the assessment of complicated duplex kidneys in children: preliminary report

OBJECTIVE

To determine whether MR imaging, including MR urography, is able to assess complicated duplex kidneys and to determine the possible role of MRI compared to other imaging techniques in such uropathies.

MATERIAL AND METHODS

Twenty consecutive patients (age 1 month-11 years) presenting with a suspicion of a complicated duplex kidney were prospectively studied with MRI and MR urography. The examinations were performed on a 0.5-T machine using routinely available sequences that were optimised to the patient's age and size. MR images were reviewed separately by two observers blinded to the patient history. They were asked to assess the presence of a duplex kidney, the presence of an abnormality that may require surgery and to indicate the type of the inferior ureteric insertion. A qualitative gradation of these results was performed on the basis of the final diagnosis provided at endoscopy (n = 6) or surgery (n = 14). MR results were compared to those provided by US examinations and excretory urography, when available, and a non-parametric statistical analysis was performed.

RESULTS

MRI differentiated well between the upper and the lower poles of the kidneys and correctly answered the three questions in all 20 patients. The two observers agreed completely in all the 20 patients. MR was statistically superior to both US and excretory urography in the evaluation of the distal ureter (P < 0.05).

CONCLUSIONS

MRI provides a precise assessment of the complications associated with duplex kidneys. Its optimal role seems to be the assessment of ectopic extra-vesical ureteric insertions and whenever an occult upper pole is suspected.

Molecular mapping of a Yq deletion in a patient with normal stature

The proximal long arm of the Y chromosome probably contains a gene (GCY) involved in stature determination. Recent reports have proposed the critical region extends from interval 4B to interval 5G (or 5E). In the present study, the deletion breakpoint in a male adult patient of normal height with a 46,X,del(Yq) karyotype was defined by the use of sequence-tagged site markers. The breakpoint was found between sY78 (interval 4B) and sY79 (interval 5A). The existence of a normal stature in this patient suggests that the growth determinant is proximal to sY79, therefore probably located in interval 4B or in proximal interval 5A of the Y chromosome.

Effect of hyperfiltration on long-term follow-up of glomerular filtration rate in male Wistar rats

It has been suggested that a prolonged course of hyperfiltration could lead to progressive deterioration of renal function. In order to test this hypothesis, the following protocol was applied to 60 male Wistar rats. At 12 weeks of life, the rats were submitted to a surgical procedure: sham operation (25 rats), unilateral nephrectomy (25 rats) or 3/4 nephrectomy (10 rats). The three groups were again divided into two subgroups: one with high-protein intake (36%) and one with a low-protein intake (12%). In order to avoid any additional traumatic procedure which could shorten the animal's life, the glomerular filtration rate (GFR) was measured without blood sampling, using a previously validated technique based on an image recorded by a gamma camera between the 9th and the 10th min after intravenous injection of 99m technetium diethylenetriaminepentaacetate (DPTA). The sum of both kidneys and bladder activity was expressed as a percentage of the injected dose. The test was performed before surgery and every month thereafter. Six weeks after surgery, the highest filtration rate was found in the rats with "two kidneys/high-protein diet", followed by the "two kidneys/low-protein diet", the "one kidney/high-protein diet", the "one kidney/low-protein diet" and the "1/2 kidney". The overall GFR in the one kidney/high-protein diet rat and in the 1/2 kidney rat was respectively 80% and 55% of the pre-operative values. Until 109 weeks of age, the survival rate was comparable in the five groups of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Pectoralis major muscle rupture in windsurfing

Board sailing (windsurfing) has become a popular water recreational activity. However, there is little in the medical literature concerning musculoskeletal complications resulting from participation in this sport. We present the first reported case of pectoralis major rupture sustained during board sailing. The patient was initially misdiagnosed, which happens commonly when this muscle ruptures. Only after conservative management failed was the correct diagnosis made and appropriate surgical intervention provided. Proper technique in board sailing requires sustained isometric contraction of the pectoralis major, deltoid and scapular stabilizers to maintain appropriate pull of the sail against wind resistance. Sharp increases in wind speed underly the mechanism of injury. Ruptures of the pectoralis major are usually complete, occur at or near the humeral insertion, and can be associated with misleading physical signs. Therefore, anatomy, clinical findings, surgical technique, and the postoperative rehabilitation program are stressed as to expedite diagnosis and maximize functional outcome.

Abnormal expression of protein 4.1 in spermatozoa of infertile men with teratospermia

Molecular defects responsible for morphologically abnormal spermatozoa (teratospermia) associated with male sterility are largely unknown. We report defective expression of protein 4.1, a cytoskeletal protein initially recognised in red cells. In some patients with severely amorphous sperm heads, protein 4.1 had an abnormal sub-cellular localisation (tail instead of head) and appeared as high-molecular-weight isoforms, especially a 135 kDa species instead of the 82 kDa isoform seen in fertile sperm. Because the 135 kDa isoform is characteristic of immature germ cells from testis, its presence in teratospermia suggests profoundly disturbed sperm differentiation.

Air medical transport of patients from offshore oil and gas facilities. Historical accident data and initial experience

The offshore petroleum exploration and production industry (OSI) is isolated from traditional means of access to emergent health care and may benefit from the unique attributes of helicopter air medical transport. This study was undertaken to review the incidence of OSI-related incidents, injuries and deaths, and report the initial experience of a civilian hospital-based helicopter air transport program in the evacuation of offshore patients. It was learned that the mean annual incidence of major OSI accidents from 1980 to 1986 was 19.1 (+/- 7.0). Mean annual mortality and reported injury were 14.7 (+/- 7.6) and 36.7 (+/- 25.4) patients respectively. Fires and explosions were the most frequently reported events at 62 per year (+/- 11.5/year). Nine OSI patients were evacuated by helicopter during the study's eight-month pilot period (seven for trauma and two for medical illness). One of the nine patients had been exposed to a potentially hazardous substance, requiring changes in the air medical team's operations, aircraft and equipment. The study shows that the offshore petroleum environment is ideally suited for air medical transport, as injuries are common and medical illnesses are to be expected. However, air medical programs operating offshore must deal with additional regulatory requirements and develop operational procedures to ensure safety during these flights.

Renal duplications: the impact of perinatal ultrasound on diagnosis and management

Perinatal urology is a rapidly expanding field in pediatric urology bringing significant changes in the diagnosis and management of congenital uropathies. Renal duplication was detected by antenatal and perinatal ultrasound in 19 cases (22 duplicated systems). In most cases, no precise diagnosis could be established in utero (4 of 13), but this lack of accuracy is of little clinical significance since all newborns with suspected uropathies undergo complete urological investigations in the perinatal period. Voiding cystogram demonstrated reflux in 11 of 22 cases. On postnatal urography a functioning upper pole was demonstrated in 11 of 22 kidneys. There were 12 ureteroceles: in 8 a nonfunctioning upper pole was removed, while 3 were endoscopically incised with good functional improvement and 1 was reimplanted. Early recognition of congenital uropathies in association with duplication by prenatal ultrasound significantly improves patient care allowing early postnatal relief of obstruction by less invasive methods and before infection or persistent obstruction worsens the prognosis.

Prospective management of neonates with pelviureteric junction stenosis. Therapeutic strategy based on 99m Tc-DPTA studies

A prospective therapeutic strategy based on separate glomerular filtration rate (SGFR) was evaluated in 14 prenatally detected asymptomatic neonates, suspected of having pelviureteric junction obstruction. The patients with low SGFR were referred for pyeloplasty with the hope to improve the renal function. A marked improvement occurred in only one patient, although the drainage function (furosemide test) did improve in all cases. A conservative attitude was adopted for those children with normal SGFR. In 6 of them, a progressive increase of SGFR was noted, related to the normal maturation of the function, followed by a stabilization in the normal range. In 1 patient, a sudden decrease of SGFR was observed around 1 year and the patient was shifted into the surgical group. In this patient, an initial partial response of the kidney to a furosemide injection changed into a persistent non-response, whereas in the other non-operated patients, partial or good response was always recorded, although the responses were essentially variable on successive tests. On the basis of these data, the protocol was slightly modified, the patients with persistent non-response to furosemide after 6 months of life being shifted to the surgical group.

Long-term follow-up of separate glomerular filtration rate in partially obstructed kidneys. Experimental study

An often encountered assumption is that non-relieved renal obstruction will lead soon or late to progressive deterioration of the renal function. The effect of non-relieved partial ureteral obstruction on the separate glomerular filtration rate (SGFR) was studied throughout the whole life of a series of rats, who were submitted at the age of 3 months to partial obstruction of the left ureter. An initial and variable postoperative SGFR decrease was gradually observed, but after this period, SGFR remained stable until the natural death of the animal.

99Tcm-DMSA uptake in obstructed kidneys. How inaccurate are the 5 h measurements?

Partial obstruction of the left ureter was created in 19 rats and a relative 99Tcm-DMSA uptake was obtained 5 and 24 h after intravenous injection of the tracer. A systematic and variable overestimation of the left to right uptake ratio was found at 5 h, with a mean error of 15.8% (S.D. = 12.2).

Radioisotopic evaluation of the renal parenchymal function in children with ureteropelvic junction obstruction. A retrospective study

Separate glomerular filtration rates were evaluated in 21 children with uni- or bilateral ureteropelvic junction stenosis, using the Tc-99m DTPA complex and the scintillation camera. The grade of alteration seen on urograms has influenced the surgeon in his decision to use a conservative or a surgical treatment, whereas the type of intervention (pyeloplasty or nephrectomy) was mainly based on the scintigraphic quantitation. The morphological data provided by an excretory urogram could not predict the degree of functional impairment. The scintigraphic evaluation of single kidney clearance was useful in the evaluation of the effects of medical and surgical treatment.

Technetium-99m DMSA imaging and the obstructed kidney

Although several authors have claimed that the function of an obstructed kidney could be overestimated on Tc-99m DMSA imaging, the clinical importance of such an overestimation has not been well documented. Partial obstruction of one ureter was created in a rat, and a relative Tc-99m DMSA uptake was obtained 4 hours after intravenous injection. By puncture of the isolated obstructed kidney, it was shown that the function of that kidney was overestimated by at least 17%.

Effect of retinoids on the growth, ultrastructure, and cytoskeletal structures of malignant rat osteoblasts

A clonal rat osteogenic sarcoma cell line, UMR 106-06, was used to study the effects of retinoic acid (RA) on its growth and morphology. Retinoic acid caused a reversible, time and dose-dependent inhibition of growth. RA-treated cells were larger, were more adherent to the substratum, and contained fewer mitotic figures. Half-maximal growth inhibition was observed at 10(-8) M. Among the naturally occurring retinoids, RA was clearly the most potent while the arotinoids, Ro 13-7410 and Ro 13-6298, were approximately 50 times more potent than was RA. A similar range of potencies was observed in the cloning efficiencies of the cells in soft agar. Fluorescence microscopy revealed that RA treatment increased the cellular content and organization of F-actin fibers. Ultrastructural changes include decreased chromatin dispersion and increased number of nucleoli per nucleus, decreased rough endoplasmic reticulum, decreased electron density and number of mitochondria, and increased formation of microfilaments and microtubules. These results identify this clonal cell line, which has been extensively characterized as the malignant counterpart of the normal osteoblast, as a target for vitamin A action.

Sensitivity of cortical transit and furosemide response in the diagnosis of renal obstruction. An experimental model

Several radionuclide parameters are routinely used for the diagnosis of renal obstruction. In order to evaluate the sensitivity of those parameters, an experimental model of partial ureteral obstruction in rats was used. Neither the cortical transit time, nor the response to furosemide could serve to discriminate between obstructive and nonobstructive kidneys. These parameters were, however, more or less related to the degree of impairment of the single kidney glomerular filtration rate and should probably be considered as functional parameters reflecting the grade of the obstructive phenomenon.

[Evaluation of medical and surgical treatment of intussusception in children apropos of a review of 100 consecutive cases]

Evaluation of medical and surgical treatment of intussusception in children (a revue of 100 consecutive cases). The authors analysed 100 consecutive cases of intussusception hospitalized in the Department of Paediatric Surgery of the Brugmann University Hospital in Brussels. 90 baryum enemas were performed, 43 of which were curative, 57 children were operated upon. Their age varied from 3 months to 10 years, but 77% of the children were less than 2 years old. The authors paid particular attention to the observations of children who had surgical treatment. This study points out the importance of early diagnosis and treatment. After a delay of 24 hours, 81% patients needed surgery compared to 41% of those who presented earlier.

[Bochdalek's congenital diaphragmatic hernia: a clinical review of 114 cases]

During a retrospective multicentric study of the encountered congenital pathology of the diaphragmatic domes, we focused our special attention on the prevalence of the congenital Bochdalek hernia. 140 charts were statistically analysed. The seriousness of the medical and surgical emergency situation enticed the authors to examine the most important prognostic clinical features. The interval between diagnosis and surgical therapy should be as short as possible. Respiratory acidosis and resuscitation were a common denomination in all infants who succumbed in the post-operative period. The early occurrence (less than 6 hrs) of respiratory distress disclosed the seriousness of the associated pulmonary hypoplasia. Surgical technical problems were rare. This in contrast to the struggle against pulmonary arterial and capillary hypertension. Pulmonary vasodilator drugs have not convinced those who initiated their use.