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Biomedical subjects

G Schubiger

Publications and source records attributed to G Schubiger.

At least 73 records · Page 4Linked to original sources
PubMed1985

Liver pathology in a new congenital disorder of urea synthesis: N-acetylglutamate synthetase deficiency.

Detoxification through the urea cycle is the means by which mammalian organisms dispose of their excess ammonia. Within this cycle, N-acetylglutamate (NAG) is the most important cofactor for optimal enzyme activity. It is formed from acetyl CoA and glutamate through the action of N-acetylglutamate synthetase (NAGS). Recently, a congenital deficiency of NAGS has been reported. In this communication, we present results of structural investigations on liver tissue of the index patient with NAGS defect. Light microscopy revealed small, eosinophilic inclusions in some of the hepatocytes. Electron microscopy showed vesicular SER and fibrillar material in expanded cisterns of the RER, presumably corresponding to the inclusions seen in light microscopy. Immunofluorescence of liver tissue uncovered a discrete distribution of intracellular albumin in the form of small deposits. We suggest that in NAGS deficiency, some secretory proteins might be incompletely processed due to the lack of a protease activator, NAG.

Acetyltransferases↗
PubMed1985

Dissociation and sorting out of Drosophila imaginal disc cells.

Previous attempts to study sorting out of Drosophila imaginal disc cells have been hampered by an inability to thoroughly dissociate these cells and the need to use cuticular markers which require several days of in vivo culture. This study overcomes these limitations by using a new dissociation procedure and a genetic marker for undifferentiated cells, the succinate dehydrogenase8 (sdh8) mutation. Dissociated and reaggregated cells from wing and leg imaginal discs segregated or "sorted out" from one another after only 24 hr of in vivo culture. It was also found that leg cells from different body segments may sort out, but to a lesser degree than wing and leg cells. Mixtures of wing and haltere cells did not sort out, in contrast to previous reports. These results constitute the first unambiguous study of sorting out with Drosophila imaginal disc cells and indicate that dorsally situated imaginal cells share a recognition specificity which is different from that of ventral imaginal cells.

Animals↗
PubMed1985

Cell proliferation changes during pattern regulation in imaginal leg discs of Drosophila melanogaster.

Upon fragmentation of a leg imaginal disc, cells near parts of the wounded surface are reprogrammed and form a blastema. This occurs without a change in fate and without the direct contact of the two wounded surfaces (G. H. Karpen and G. Schubiger, Nature (London) 294, 744-747, 1981). Two phases of the cell cycle have now been analyzed for several areas of disc fragments prior to and during wound healing. A mitotic index was used to compare the location of cell division, and autoradiography was used to reveal patterns of DNA synthesis. In contrast to the uniform division pattern in noncultured fragments, more dividing cells were observed near the two wound surfaces after 1 day of in vivo culture. During the second day, wound healing began and mitotic activity increased dramatically near both wound areas, and decreased in distant areas. Three and a half days of culture led to more complete wound closure and only cells on one site continued to show the highest frequency of labeled cells. It is concluded that changes in patterns of DNA synthesis and an increase in cell division begin prior to wound closure. This proliferation is consistent with the morphological changes and regulative behavior observed. In addition, the role of compartmental identity during regulation was tested. After wound closure began an increase in mitotic activity near wounds in the anterior compartment was observed whereas such an increase in division level was not seen in posterior cells near a wound.

Animals↗
PubMed1985

Prenatal sonographic diagnosis of Jeune syndrome.

Asphyxiating thoracic dysplasia (Jeune syndrome) is characterized by a narrow thoracic cage, which causes severe respiratory failure with frequent perinatal death; brachymelia, predominantly of the rhizomelic type; renal anomalies; and characteristic radiographic findings of ribs, pelvis, and long tubular bones. Inheritance is autosomal recessive. Prenatal sonographic examination was performed at 17 and 19 weeks of a fetus of parents whose first child had died of Jeune syndrome. The length of the humeri, femora, and tibiae was short (below the mean) for gestational age, and the thorax was abnormally flat and narrow. The iliac wings were square-shaped. We concluded that the fetus had Jeune syndrome. The characteristic skeletal changes of Jeune syndrome are distinct enough at 17 weeks of fetal age to permit sonographic diagnosis.

Adult↗
PubMed1985

Feeding of very-low-birth-weight infants with breast-milk enriched by energy, nitrogen and minerals: FM85.

Although human milk is the best tolerated nutrition for very-low-birth-weight infants, it does not cover the special requirements of premature babies. The protein content does not allow a growth rate comparable to the intrauterine weight gain, and the calcium and phosphorus supply is by far too small for a full mineralization of the growing skeleton. If a sufficient caloric supply should be achieved, the low energy/water ratio leads to a high volume load for stomach and circulation. We therefore searched for a solution with an enriched human milk. As main energy carrier, polydextrose (dextrinmaltose) is added; the protein content is raised to 2.5 g/100 kcal by the addition of amino acids and small peptides and the mineral content is supplemented by calcium salts and phosphates. These ingredients are premixed; addition of 5 g% of this mixture results in a human milk with 85 kcal/100 ml and an optimal concentration of calcium, phosphate, sodium, potassium, chloride and magnesium. This feeding procedure is simple, safe, and without any practical difficulties.

Calcium↗
PubMed1984

[Perinatal and neonatal mortality and morbidity in central Switzerland in 1982. An analysis of all newborns in a geographically circumscribed region].

In assessment of the perinatal situation in Central Switzerland, all 5616 infants born in the geographically surrounding areas of the Children's Hospital Lucerne have been statistically evaluated, according to birth place, birth weight, gestational age, perinatal condition, and postnatal development. 76 infants (1.4%) were born at home, 417 births (7.5%) took place before the completed 37th gestational week. Only 5.8% of our newborns had weights below the 10th percentile according to the Winterthur percentile curves used in Switzerland. The perinatal mortality was 12.9%, the neonatal mortality 7.1%. 2/3 of the deaths concern either extremely premature babies or infants with severe congenital malformations. The recorded malformations coincide with the known incidence, with the exception of trisomy 21, which marked an incidence of 1:1400. 8% of all live-born babies (499) needed special neonatal care. Among the preterm infants, every 2nd, and among the full-term babies every 12th had to be transferred to the neonatal care unit. Most of the transferrals were due to simple disturbances of adaptation (6% of all live-borns), whereas 1% required intensive care because of severe disorders. In 50 babies (1% of all live-borns), the neonatal diagnosis allows to anticipate a reduction of the quality of life.

Birth Weight↗
PubMed1983

Immobilisation hypercalciuria after limb fractures in children.

Immobilisation hypercalciuria and hypercalcaemia following limb fractures or paralysis is a frequent occurrence in children. Assessment of calcium metabolism should be performed in such patients, since the formation of kidney stones is possible. The beneficial effect of hydrochlorothiazide (HCT) in the prevention of renal stones is most likely due to a reduction of calcium concentration in urine and a significant decrease of crystalluria. Thus, its administration is recommended for children with hypercalciuria following prolonged immobilisation especially due to fracture treatment or paralysis.

Adolescent↗
PubMed1982

[Superior sagittal sinus thrombosis is the newborn--diagnosis by computerized tomography].

The case of a newborn with a superior sagittal sinus thrombosis is reported. The clinical symptoms are difficult to differentiate from other cerebral conditions in the neonatal period. Sudden appearance of signs of raised intracranial pressure, however, is characteristic. Main predisposing factors are infection, dehydration and polycythemia. Before computed tomography (CT) became available, the diagnosis could be made only by means of invasive examination techniques. Today CT, in many cases, allows a rapid diagnosis of this condition.

Cerebrospinal Fluid Shunts↗
PubMed1982

[Transcutaneous bilirubin determination in the newborn infant. Recommendations of the Swiss Neonatology Group].

The clinical usefulness of transcutaneous bilirubinometry with the Minolta-Air Shield bilirubinometer was evaluated at four obstetrical neonatology units (Basle, Berne, Lucerne and Zurich). Transcutaneous bilirubin (TcB), expressed as bilirubin index, was compared with simultaneous serum bilirubin estimations in healthy Caucasians babies born at term with a birth weight of more than 2500 g. TcB measured over the forehead: 926 determinations in 629 newborns. TcB measured over the sternum: 404 estimations in 260 newborns. TcB estimations over the sternum produced a closer correlation (r = 0.93) with serum bilirubin than estimations over the forehead (r = 0.81). Mean serum bilirubin value as well as the corresponding 5th and 95th percentiles were calculated for each TcB index. From the data obtained the following practical conclusions can be drawn: TcB estimations are reliable for giving the indication to perform serum bilirubin determinations. In patients with risk factors for kernikterus serum bilirubin should be determined at a TcB index of greater than or equal to 18, in babies without risk factors at a TcB index of greater than or equal to 21.

Bilirubin↗