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Biomedical subjects

W Lambrecht

Publications and source records attributed to W Lambrecht.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Results of treating patients with pleural empyema in relation to time of diagnosis].

Results of surgical treatment of 182 patients with pleural empyema were assessed. Patients were divided into 2 groups according to the length of time between the beginning of illness and the start of treatment at the thoracosurgical department. The first group consisted of 36 patients in whom the draining of empyema's chamber was applied no later than 7 days after the onset of illness. This treatment was effective in 31 (86%) of patients. The remaining, 14% of patients required operative treatment. The second group consisted of 146 patients who were admitted to surgical department later than 7 days from the beginning of disease. 33% of them required operative treatment. The results achieved in both groups of patients proved that the time lapse between, the beginning of disease and the confirmation of suppurative character of exudation, had a decisive influence on the surgical procedure and the final results of treatment.

Adolescent↗
PubMed1995

Bleeding esophageal duplication detected in utero.

Peptic complications in duplications of the alimentary tract may occur when the duplication is lined by gastric mucosa. These complications commonly develop in the first year of life. We report a case of a bleeding esophageal duplication in a fetus.

Adult↗
PubMed1995

The principles of normal and abnormal hindgut development.

In the past, several theories have been proposed to explain the occurrence of anorectal malformations. Most investigators believe that these malformations are the result of an impaired process of septation. However, in 1986 vd Putte challenged all theories that tried to explain anorectal malformations by a faulty fusion of lateral ridges of the cloaca. To elucidate the principles of normal and abnormal cloacal development, the authors studied the morphology of this region in normal embryos of rats and abnormal embryos of SD mice, which often have abnormal cloacas. Using scanning electron microscopy (SEM), 245 normal rat embryos and 80 abnormal SD-mice embryos were observed. The results were as follows. (1) In normal embryos the region of the future anal opening can be identified soon after the establishment of the cloacal membrane. This part is a fixed point in cloacal development. (2) In abnormal embryos the cloacal membrane is too short. The region of the future anal opening is missing. (3) In abnormal embryos a spectrum of malformed cloacas can be observed. This is in accordance with the spectrum of anorectal malformations clinically observed in humans. (4) The authors' observations support recent findings that the "fistula" in anorectal malformations resembles a normal anus at an ectopic position.

Allantois↗
PubMed1995

Rotation of the gut: fact or fantasy?

Clinicians, as well as embryologists, believe that normally a process of rotation of the midgut takes place that can be hampered at any stage resulting in the different types of "malrotations." However, a "malrotated" gut has never been observed in normal embryos. Therefore all theories on the normal and abnormal development of the gut are still highly hypothetical. In an attempt to elucidate more clearly which events occur during the development of the gut, the authors studied its embryology in 58 normal rat embryos between the 13th and 20th day of gestation using scanning electron microscopy. In 13 day old rat embryos, the midgut has already formed a loop. It can be subdivided into three parts: the central part with its connections to the stomach and leading to the straight part, with the colorectum on the left and the "small bowel" on the right, and the tip of the loop inside the umbilical cord. These three parts show no signs of developmental synchronization. Each part develops according to its own developmental blueprint: the duodenal and umbilical parts of the midgut show much developmental activity, whereas gross changes of the straight part of the midgut are not seen. This finding is surprising because a process of rotation, if occurring, should result in notable morphological changes especially in this region. Furthermore, the coecum never achieved a position in the upper left abdomen, as is often outlined in schematic drawings. After the return of the bowel into the abdominal cavity, the coecum lies exclusively on the right side of the midline close to the ventral abdominal wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

[Successful operation of a symptomatic aneurysm of the superior mesenteric artery in a child with Ehlers-Danlos syndrome].

Bleeding of an aneurysm--especially of a great vessel--represents a complication of Ehlers-Danlos syndrome that is often lethal. A successful operation of a symptomatic aneurysm of the superior mesenteric artery in a 12-year old girl with an Ehlers-Danlos syndrome type VI is reported. The aneurysm was resected and replaced by a venous graft. Four years postoperatively the artery is perfectly patent; a new aneurysm did not develop.

Aneurysm↗
PubMed1995

[Rotation of the intestine--an illusion or reality?].

Disorders of intestinal rotation present with a wide spectrum of abnormalities. This variety is attributed to the puzzling embryology of the midgut. Clinicians, as well as embryologists, believe that normally a process of rotation of the midgut takes place which can be hampered at any stage resulting in the different types of "malrotations". However, a "malrotated" gut has never been observed in normal embryos. Therefore all theories on the normal and abnormal development of the gut are still highly hypothetical. In an attempt to elucidate more clearly which events occur during the development of the gut, we studied its embryology in 58 normal rat embryos between the 13th and 20th day of gestation using scanning electron microscopy. In 13 day old rat embryos, the midgut already forms a loop. It can be subdivided into three parts: the central part (with its connections to rectum and stomach), the straight part (with the colorectum on the left and the "small bowel" on the right) and the tip of the loop (inside the umbilical cord). Obviously, these three parts show no signs of developmental synchronization. Each part develops according to its own developmental blue print: the duodenal and umbilical parts of the midgut show much developmental activity, while gross changes of the straight part of the midgut are missing. This finding is surprising because a process of rotation, if occurring, should result in notable morphological changes especially in this region. Further more, the coecum never achieved a position in the upper left abdomen, as it is often outlined by schematic drawings.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Esophageal atresia: a new anatomic variant with gasless abdomen.

Until this study, 20 pathological-anatomic variants of esophageal atresia with a blind upper pouch and a distal tracheoesophageal fistula (type IIIb according to Vogt) had been described. The authors observed another variant, with the following characteristics: (1) an abnormally long lower segment that entered the trachea in the region of the upper thoracic aperture, (2) a long atretic proximal portion of the lower segment, and (3) an additional membrane in the lower segment. After resection of the atretic part of the lower segment and excision of the membrane, a primary anastomosis could be performed. This variant of type IIIb is characterized by a gasless abdomen.

Air↗
PubMed1993

The natural history of congenital diaphragmatic hernia and pulmonary hypoplasia in the embryo.

Up to now, descriptions of the natural history of congenital diaphragmatic hernia (CDH) associated with pulmonary hypoplasia (PH) are based exclusively on observations made in the fetal period. However, nothing is known about the events that take place in an embryo with CDH. Recently, an animal model of CDH and PH has been established in rat embryos to study the embryology and natural history of this lesion. We exposed 36 pregnant Sprague-Dawley rats to a single dose of 100 mg nitrofen on day 11 of pregnancy. A total of 356 staged embryos and fetuses from day 13 to day 21 were studied by light and scanning electronmicroscopy. The litters of 9 untreated rats (124 normal age-matched embryos and fetuses) served as controls. The abnormal development of the diaphragmatic anlage was first seen in embryos aged 13 to 14 days. A defect appeared in the dorsal part of the diaphragm, normally on the right side. The liver grew through this defect early on. Gut was found in an intrathoracic position only in the very late stages (day 21/22) and newborns. Compared to controls, lungs of nitrofen-embryos with CDH were smaller, depending on the size of liver found in the thoracic cavity. Histologically, compression of lung was absent at these stages. Most authors speculate that CDH results because the pleuroperitoneal canals fail to close at the end of the embryonic period (ie, week 8 to 10 in human development) leading to a defect in the dorsolateral region of the diaphragm. However, contradictory to this assumption, our findings indicate that diaphragmatic defects develop in early embryonic life.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Infectious risks of Broviac catheters in children with neoplastic diseases: a matched pairs analysis.

In the present study the complication rate of Broviac catheters in the therapy of children with cancer was determined. Of special interest was the question of to what extent the incidence of bacteremias is increased by the implant. For this reason the method of matched pairs analysis was chosen comparing 55 patients with 61 catheters to 1 child each who received the therapy via peripheral veins. Apart from having the same disease, the same therapy protocol and the same age group the partners had a similar number of leukocytopenic days (leukocyte counts, < 1000/microliters) in the study period. The observation time was 9671 days in the catheter group and 9666 days in the control group. During this time 167 fever episodes (17.7 episodes/1000 days) were recorded in the patients with implant but only 133 episodes (14.0/1000 days) in the control patients. Study and control groups had similar frequencies of fever of unknown origin with leukocyte counts > or = 1000/microliters and fever with a known focus. However, 29 bacteremias (2.9 episodes/1000 days) represented a 4 times higher complication rate with the use of Broviac catheters than in the control group (7 bacteremias, 0.7 episode/1000 days). Episodes of fever of unknown origin with leukocytopenia were 1.5 times more common in the catheter group than in the control group. Although it is not possible to prove that the catheter played a role as focus of bacterial infection, an increased risk of infection must be supposed. The Broviac catheter meets with broad approval by the patients, parents and medical staff.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗
PubMed1991

SD-mice--an animal model for complex anorectal malformations.

Animal models for morphological investigations of anorectal malformations are barely known to pediatric surgeons. In this study the morphological characteristics of a spontaneous mutation of the house mouse, the so-called SD-mouse, are described. The semidominant gene SD exerts its influence on the anorectum, the urogenital system and the axial skeleton. Many heterozygous (SD/+) and all homozygous (SD/SD) animals die shortly after birth due to their malformations. Surviving heterozygotes, identified by their short and deformed tails, may be used for breeding purposes. According to Mendel's laws, mating of such heterozygous yields 75% more or less malformed animals which may be used for morphological investigations. The morphological features of these animals were investigated in 61 neonatal SD-mice (33 SD/SD, 28 SD/+) and in 10 normal controls by microdissection and in 49 animals (25 SD/SD, 20 SD/+ and four normal controls) by serial sections. Of these, all homozygous and 10 heterozygous SD mice had anorectal malformations. The spectrum of these malformations is wide: very complex malformations in SD/SD mice and high anorectal malformations in SD/+ mice. These are comparable to morphological features found in humans and piglets. Hence the SD mouse represents an animal model for morphologic and embryonic investigations of complex anorectal malformations.

Anal Canal↗
PubMed1990

Nitrofen-induced diaphragmatic hernias in rats: an animal model.

In embryological terms, pathogenesis of congenital diaphragmatic hernia (CDH) associated with pulmonary hypoplasia is still unclear. However, it is known since 1971 that Nitrofen (2,4-dichloro-phenyl-p-nitrophenyl ether) can induce anatomical malformations in rats including diaphragmatic hernias. On order to establish an animal model of the embryogenesis of CDH, the effect of Nitrofen on the developing diaphragm was studied. Thirty-three pregnant female rats were exposed to Nitrofen. Five unexposed pregnant rats served as controls. In the first set of experiments, single doses of Nitrofen were given between the 9th and 13th day of pregnancy. In the second set of experiments, dosages of 50, 100, and 150 mg per animal were given on day 11 of pregnancy only. Postnatally the litters (469 newborn rats) were dissected to record the incidence of diaphragmatic malformations. The results were: (1) most hernias occurred after administration of 100 mg Nitrofen on day 9 (42%) and 11 (59%); (2) left-sided hernias were observed only after exposure to Nitrofen on day 9; (3) after exposure on day 10 or later all hernias were on the right side; and (4) Fifty-nine percent of the newborn rats exposed on day 11 had CDH. These results show that this model is suitable for further embryological investigations on the development of CDH.

Animals↗
PubMed1989

[Epithelium and anal glands in rectal pouches and fistula. Histologic studies of swine with congenital anal atresia].

The epithelial coating of the rectal pouch and fistula was studied morphologically in 33 newborn piglets with high and low forms of anal atresia and was found to be similar to the epithelial coating of the anal canal in normal piglets: the typical epithelium of the rectum changed its character into transitional epithelium at the region of the internal sphincter which surrounded the fistulae in all animals. In the caudal part of the fistula the transitional epithelium was followed by squamous epithelium. Only in male piglets with deformities and recto-urethral fistulae no squamous epithelium was found. In these cases transitional epithelium covered all parts of the fistula and the region of the internal sphincter. Anal glands were found in all animals, with or without anorectal malformations. They always invaded the internal sphincter. According to our morphological studies the fistula in anorectal malformations represents an ectopic anal canal.

Anal Canal↗
PubMed1988

Pathogenesis of hypospadias--more questions than answers.

Most researchers believe that hypospadias arises from malformation of the penile urethra. However, this concept has been recently rejected, and it has been suggested that the opening of the urethra is "pushed forward" by growth of the perineum. In order to obtain more information on the development of the urethra, late stages of phallic development were studied in 220 rat embryos with scanning electron microscopy (SEM). In our study, signs of rupture of the urogenital membrane or fusion of the urethral folds could not be found. Therefore, we could not confirm the traditional concept for the development of the phallic urethra. A new concept of urethral development is suggested and the pathogenesis of hypospadias is discussed.

Animals↗
PubMed1987

The internal sphincter in anorectal malformations: morphologic investigations in neonatal pigs.

The knowledge of sphincter anatomy in anorectal malformations is still inadequate and contradictory. Therefore, morphologic investigations were carried out in 33 neonatal piglets with congenital anal atresias. Of the 24 male animals 12 had high anomalies with a rectourethral fistula. The remaining 12 piglets had low anomalies; in nine cases we were able to demonstrate an anocutaneous fistula. Of the nine female animals, six had high anomalies with a rectovaginal fistula. The three female piglets with low anomalies had an anovestibular or an anocutaneous fistula. In all animals we could demonstrate a normal internal sphincter, which surrounded the proximal part of the fistulae. The position of the internal sphincter therefore depended on the localization of the fistula orifice into the rectal pouch. This differed greatly. The form of the internal sphincter also differed greatly. Sometimes the muscle had the form of a tube or an acute-angled funnel as in healthy piglets. However, mostly the internal sphincter was spread out wide and had the form of a disc or a flat dish. The proximal region of the fistulae in anal atresias has most features of a normal anal opening: (1) it is surrounded by an internal sphincter, (2) the rectal pouch in the region of the internal sphincter as well as the fistulae are hypoganglionotic, (3) the proximal fistula region is lined by transitional epithelium, and (4) it contains anal glands. We, therefore, consider that the fistula should be designated as an ectopic anal canal. The most important result was the demonstration of a normal internal sphincter even in high and intermediate anomalies of anal atresias.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Canal↗
PubMed1987

[Morphologic studies in swine with anal atresia].

33 piglets with anorectal malformations were investigated histologically. 24 animals were male, 9 female. 18 piglets had high deformities with recto-urethral, respectively recto-vaginal fistulas. 15 animals had low deformities. In all animals we were able to demonstrate a sphincter internus muscle and a sphincter externus muscle. The sphincter internus muscle was localised around the fistula. These fistulas also had other characteristics of a normal anal opening.

Anal Canal↗
PubMed1986

[Vascular supply of the rectum in anal atresia. Angiography studies in newborn swine].

In 15 piglets with anorectal malformations (high and low anomalies) we performed angiographies of the pelvic arterial system. 3 healthy animals were used as control group. None of the animals had isolated rectal atresia which is assumed to be due to vascular disorders. In all animals we could demonstrate normal superior and inferior rectal arteries. Thus our results support the hypothesis that anorectal malformations, with the exception of isolated rectal atresia, are not associated with vascular malperfusion during embryogenesis.

Angiography↗