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Biomedical subjects

F Collier

Publications and source records attributed to F Collier.

At least 19 recordsLinked to original sources

How to interpret a deterioration of split function?

OBJECTIVE: A drop of split renal function often constitutes a criterion for pyeloplasty in hydronephrosis since it is considered as representing deterioration of the affected kidney. The aim of this work was to determine, in a selected population of patients with a drop of split function of at least 5%, if the evolution of single kidney glomerular filtration rate (SKGFR) was parallel to the one of split renal function. METHODS: From a large data basis, we found retrospectively only 29 children (10 below and 19 above two years of age at first examination) having had at least two Tc-99m mertiatide (Tc-99m MAG3) renographic explorations for various urological diseases, with a decrease of split function of at least 5% between the two examinations. Evolution of split function was compared to evolution of SKGFR obtained by means of the combination of Tc-99m MAG3 split function and overall glomerular filtration rate as given by the chromium Cr 51 ethylenediamine tetraacetic acid (EDTA) clearance. RESULTS: For the group above two years of age, SKGFR increased or remained stable in 63% of the cases, while in the children less than 2 years of age, a decrease of SKGFR was never observed, according to the maturation of overall GFR in this age group. Thus, the decrease of split function was not necessarily associated with a similar decrease of SKGFR. CONCLUSION: In patients with unilateral or bilateral urological disorders, deterioration of split renal function does not necessary correspond to a loss of function of the affected kidney. SKGFR often modifies the interpretation of split function.

Chelating Agents↗

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.

Child↗

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.

Adult↗

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.

Cytoskeletal Proteins↗

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)

Animals↗

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.

Adult↗

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.

Congenital Abnormalities↗

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.

Clinical Protocols↗

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.

Animals↗

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.

Adolescent↗

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%.

Animals↗