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Biomedical subjects

F Rypens

Publications and source records attributed to F Rypens.

10 recordsLinked to original sources
PubMed1992

A hypothesis for the higher incidence of vesico-ureteral reflux and primary megaureters in male babies.

The authors propose a new explanation for the male preponderance in cases with prenatally diagnosed vesico-ureteral reflux and primary megaureters. The theory is based on conclusions drawn from the characteristics of 4 patients (3 perinatal cases and 1 occurring in a 14-year-old boy) presenting with unusual anomalies of the lower urinary tract. In this hypothesis, the male preponderance could be related to an abnormal dilatation of the posterior urethra occurring during the embryological development of the male urethra. The dilatation leads to a flap valve mechanism and to a functional obstruction of the bladder outlet and finally to secondary dilatation of the upper urinary tract. This obstruction may be transitory; reflux and megaureters found in utero or after birth could be considered as sequellae of this phenomenon.

Adolescent↗
PubMed1992

Unusual splenic complication of acute pancreatitis.

Splenic complications of acute pancreatitis are rare. We describe a spontaneous subcapsular splenic laceration during an episode of acute pancreatitis, without any evidence of one of the currently reported predisposing factors. Its spontaneous resolution suggests that conservative therapy can be proposed in such complications.

Acute Disease↗
PubMed1992

Abdominal muscle use during breathing in patients with chronic airflow obstruction.

To assess the pattern of abdominal muscle contraction in stable patients with chronic obstructive pulmonary disease (COPD), we studied electromyograms of the rectus abdominis, external oblique, and transversus abdominis muscles in 40 patients with variable degrees of chronic airflow obstruction (FEV1 between 17 and 82% of predicted); 12 control subjects with normal pulmonary function tests were studied for comparison. The subjects were studied during resting breathing in the supine posture, and the electromyograms were recorded with concentric needle electrodes implanted with the aid of a high-resolution ultrasound. The rectus abdominis and external oblique were silent in virtually all patients. In contrast, 17 patients had invariable phasic expiratory activity in the transversus abdominis, and 11 additional patients had intermittent transversus expiratory activity. Expiratory contraction of the transversus was related to the degree of airflow obstruction (p less than 0.005), and when present, it persisted in the seated posture. We conclude that (1) when breathing at rest, many stable patients with severe chronic airflow obstruction contract the abdominal muscles during expiration, and (2) this expiratory contraction is usually confined to the transversus muscle. These observations also indicate that the physiology of dynamic hyperinflation and intrinsic positive end-expiratory pressure (PEEP) in such patients should be reevaluated.

Abdominal Muscles↗
PubMed1992

The ureterovesical junction in children: sonographic findings after surgical or endoscopic treatment.

We retrospectively analyzed pre- and postoperative sonographic and medical records of 335 children who had surgical or endoscopic treatment at the ureterovesical junction, in order to determine normal and atypical sonographic appearances. Normal sonographic findings after ureteral reimplantation include thickening of the posterior bladder wall, pseudodiverticular sacculations, bladder asymmetry, and transitory hydroureteronephrosis. Short-term or persistent (lasting more than 1 month) hydroureteronephrosis, urinoma, hematoma, bladder lithiasis, and diverticula were abnormal findings, occurring in 17% of the patients. After partial ureteronephrectomies, visualization of the residual ureter on sonograms was not possible in cases without complications; in one patient, reflux of fluid dilated the residual ureter and made the ureter visible on sonograms. After endoscopic incisions, the masslike appearance of a collapsed ureterocele was observed. Submucosally injected Teflon always appeared as a curvilinear hyperechoic area with an acoustic shadow. Marked acute or persistent hydroureteronephrosis or ectopic intracavitary Teflon particles were observed in 2% of patients. Granuloma formation was considered likely in 5% of the patients when the area of injected Teflon material was longer than 12 mm on sonograms. Submucosally injected collagen appeared less echogenic than Teflon and showed no acoustic shadowing. The various normal sonographic appearances after treatment must be known in order to distinguish them from significant abnormalities. In patients with anatomic anomalies, such as short-term or persistent hydroureteronephrosis, urinoma, hematoma, and lithiasis, complementary uroradiologic examinations may be necessary to clarify the diagnosis.

Adolescent↗
PubMed1991

Peri-cholecystic hyper-echogenicities in necrotizing enterocolitis: a specific sonographic sign?

The authors report a new sonographic pattern found in association with neonatal necrotizing enterocolitis in 5 newborns: hyperechogenicities around the gallbladder. The pattern probably corresponds to extension of the disease to the perivesicular space. The most probable hypothesis for that extension is diffusion by contiguity through the lesser sac and/or the right gutter. The hyperechogenicities could be related to the foamy infiltrate typical of NEC. Air within the pericholecystic vascular system similar to portal air could be another (less probable) explanation.

Enterocolitis, Pseudomembranous↗
PubMed1991

[The value of current imagery techniques in dentistry and stomatology].

Computed tomography, ultrasonography and magnetic resonance imaging are currently used in stomatology and dentistry. These recent imaging modalities have suppressed or reduced classic examinations (by example: conventional tomography and sialography). Efficient, exact and fast, they improve the diagnostic capacities and optimize the choice of the treatments. After some technical considerations, their applications in various stomatology and dentistry problems are evoked.

Diagnostic Imaging↗
PubMed1989

[Cervical ectopic thymus].

Two cases of cervical aberrant thymus in infants are reported; it's important to identify such ectopia because thymic tissue involutes spontaneously later on; neither surgery nor other treatment is needed. Ultrasonography is a method of choice for tissue characterization of ectopic thymus and differential diagnosis with other cervical masses.

Diagnosis, Differential↗
PubMed1988

Epithelial and neuronal calbindin in avian intestine. An immunohistochemical study.

It is well known that calbindin immunoreactivity is highly concentrated in the duodenal absorptive cells of young birds. We have shown that in the adult intestine of three avian species, calbindin content is much more variable. In addition to absorptive cells, we have detected throughout the gut of both sexes of the domestic fowl and in the large intestine of the Japanese quail a second type of calbindin-positive epithelial cell which has the shape of a typical endocrine cell. These cells were particularly abundant in the large intestine, in contrast to the usual distribution of endocrine cells along the gut. Calbindin was also detected in the nervous system of the intestine. Calbindin-positive nerve fibres were rare in the duodenum and ileum, numerous in plexuses and nerve processes in both muscular layers and lamina propria of the large intestine in domestic fowl and Japanese quail. In the mallard, nerve fibres were rarely calbindin positive while definitively positive for VIP. Calbindin of the peripheral nervous system of the domestic fowl and Japanese quail comigrates with the duodenal calbindin (27,000 dalton) in SDS gel electrophoresis.

Animals↗
PubMed1987

Calbindin in vertebrate classes: immunohistochemical localization and Western blot analysis.

Calbindin immunoreactivity was investigated in various vertebrates. Positive labeling was observed in the absorptive cells of the duodenum of all birds and reptiles but not in mammals, amphibia, or fish. Staining was present in the kidney distal convoluted tubule from amphibia and higher vertebrates. Fish kidney was negative. In the central nervous system of all species investigated, cellular bodies and fibers were Calbindin positive. Their distribution was quite broad and correlates well with the previously reported mapping for chick and rat. Western blot analysis revealed two Calbindins in brain from mammals, birds, reptiles, and amphibia (27,000 and 29,000 Da). Only one band was detected in fish. We conclude that Calbindin from the evolutionary point of view is primarily a neuronal protein, with a highly conservative character.

Amphibians↗