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Biomedical subjects

P Daniel

Publications and source records attributed to P Daniel.

At least 37 records · Page 2Linked to original sources
PubMed1995

Role of subunit-9 of mitochondrial ATP synthase in Batten disease.

The role of subunit-9 of mitochondrial ATP synthase in Batten disease was defined by characterizing the expression of genes encoding this protein in human tissues. Two genetically distinct neuronal ceroid-lipofuscinoses (NCL) comprise Batten disease: the late-infantile (LINCL) and juvenile (JNCL) types. We tested cell lines and tissues from both types of patients, along with normal controls. Differences in expression between diseased and normal samples were found for both mRNA and protein. Antibody staining of subunit-9 protein was detected in LINCL and JNCL tissues, and in 6 LINCL and 4 of 5 JNCL fibroblast lines. No immunoreactivity was seen in fibroblasts from obligate carriers, normal controls, and 6 other storage disease controls, with the exception of faint staining in Niemann-Pick, type C cells. There was an appreciable difference in staining pattern in both tissue sections and fibroblasts between LINCL and JNCL. Three subunit-9 transcripts (Hum1, Hum2, and Hum3) were specifically detected in NCL and normal human tissue from heart, liver, brain, muscle, and pancreas. Transcriptional regulation of subunit-9 genes was found to be altered in Batten disease. Pseudogenes related to each of the subunit-9 genes were isolated. Sequence analysis of cDNAs spanning the protein-coding regions of the Hum1, Hum2, and Hum3 genes showed conclusively that the primary defect(s) causing NCL are not mutations in the protein-coding regions of the 3 known subunit-9 genes.

Adult↗
PubMed1994

Regulation of apoptosis in the immune system.

Apoptosis in T and B lymphocytes is involved in all fundamental processes in the immune system. It is a mechanism to regulate the course of an immune response and to establish immunological memory as well as central and peripheral tolerance. Apoptosis in lymphocytes is regulated by gene products that induce or block this process. Elucidating the molecular basis for sensitivity and resistance towards induction of apoptosis is the key to the understanding of the development of the immune system, basic immune reactions and the pathogenesis of autoimmune diseases, AIDS and cancer.

Animals↗
PubMed1992

Substrate specificity of human liver neutral alpha-mannosidase.

The digestion of radiolabelled natural oligosaccharide substrates by human liver neutral alpha-mannosidase has been studied by h.p.l.c. and h.p.t.l.c. The high-mannose oligosaccharides Man9GlcNAc and Man8GlcNAc are hydrolysed by the enzyme by two distinct non-random routes to a common product of composition Man6GlcNAc, which is then slowly converted into a unique Man5GlcNAc oligosaccharide, Man alpha(1----2)Man alpha(1----2)Man alpha(1----3)[Man alpha (1----6)] Man beta(1----4)GlcNAc. These pathways are different from the processing and lysosomal catabolic pathways for these structures. In particular, the alpha(1----2)-linked mannose residues attached to the core alpha(1----3)-linked mannose residue are resistant to hydrolysis. The key processing intermediate, Man alpha(1----3)[Man alpha(1----6)]Man alpha(1----6)[Man alpha(1----3)] Man beta(1----4)GlcNAc, is not produced in the digestion of high-mannose glycans by the neutral alpha-mannosidase, but it is hydrolysed by the enzyme by a non-random route to Man beta(1----4)GlcNAc via the core structure Man alpha(1----3)[Man alpha(1----6)]Man beta(1----4)GlcNAc. In contrast with its ready hydrolysis by lysosomal alpha-mannosidase, the core alpha(1----3)-mannosidic linkage is quite resistant to hydrolysis by neutral alpha-mannosidase. The precise specificity of neutral alpha-mannosidase towards high-mannose oligosaccharides suggests that it has a role in the modification of such structures in the cytosol.

Carbohydrate Conformation↗
PubMed1991

The substrate-specificity of human lysosomal alpha-D-mannosidase in relation to genetic alpha-mannosidosis.

The specificity of human liver lysosomal alpha-mannosidase (EC 3.2.1.24) towards a series of oligosaccharide substrates derived from high-mannose, complex and hybrid asparagine-linked glycans and from the storage products in alpha-mannosidosis was investigated. The enzyme hydrolyses all alpha(1-2)-, alpha(1-3)- and alpha(1-6)-mannosidic linkages in these glycans without a requirement for added Zn2+, albeit at different rates. A major finding of this study is that all the substrates are hydrolysed by non-random pathways. These pathways were established by determining the structures of intermediates in the digestion mixtures by a combination of h.p.t.l.c. and h.p.l.c. before and after acetolysis. The catabolic pathway for a particular substrate appears to be determined by its structure, raising the possibility that degradation occurs by an uninterrupted sequence of steps within one active site. The structures of the digestion intermediates are compared with the published structures of the storage products in mannosidosis and of intact asparagine-linked glycans. Most but not all of the digestion intermediates derived from high-mannose glycans have structures found in intact asparagine-linked glycans of human glycoproteins or among the storage products in the urine of patients with mannosidosis. However, the relative abundances of these structures suggests that the catabolic pathway is not the same as the processing pathway. In contrast, the intermediates formed from the digestion of oligosaccharides derived from hybrid and complex N-glycans are completely different from any processing intermediates and also from the oligosaccharides of composition Man2-4GlcNAc that account for 80-90% of the storage products in alpha-mannosidosis. It is postulated that the structures of these major storage products arise from the action of an exo/endo-alpha(1-6)-mannosidase on the partially catabolized oligomannosides that accumulate in the absence of the main lysosomal alpha-mannosidase.

Chromatography, High Pressure Liquid↗
PubMed1990

[Treatment strategy and results in large covered and perforated omphaloceles and gastroschisis in newborn infants].

The primary abdominal wall closing together with complete lining of the reconstructed abdominal cavity with peritoneum has been proved optimal in gastroschisis and omphalocele therapy. Otherwise a separate replacement of each abdominal wall layer should be tried. So autologous amnion tissue can be used to replace the peritoneum as homo- and heterologous lyophilised dura tissue can serve as fascia and even further as skin. In this way infections, respiratory and circulatory insufficiency can be easier prevented.

Abdominal Muscles↗
PubMed1990

[Fundamental research in ultrasonic surgery. IX. Splenic surgery using cavitation ultrasound--an experimental animal study of aspiration and sealing technics with ligament FIMOMED].

A farther alternative for the conservation of the spleen represents the ultrasonic aspiration and sealing technique by means of the monomeric tissue adhesive Ligament Fimomed. The effectiveness of the method was proved by histomorphologic investigations in animal experiment with the porcine spleen. The method was effective in nearly all injuries across to the longitudinal axle of the organ even with a larger parenchymal defect and also in case of splenic tumor. The control of hemorrhage succeeded promptly and surely. Not any postoperative complication appeared.

Animals↗
PubMed1990

[A new technique for intestinal anastomosis in surgery of newborn infants].

Through a cuff-like resection of different intestinal wall layers an intramural step-like and edge-to-edge-sutured anastomosis can be performed without any tendency of narrowing. In segments with different lumen, in combination with a lobed resection from the distal segment this technique has a good advantage because the sutures are not lying upon each other.

Adolescent↗
PubMed1990

[Liver and spleen surgery using cavitating ultrasound].

Liver and spleen can be selectively skeletized by means of ultrasonosurgery (10-200 W/cm2, 20-40 kHz). These are technological solutions which have provided major prerequisites for low-risk oncosurgery. The technique (ultrasonic sealing) can as well be used in conjunction with monomeric tissue glues to safely and hermetically seal areas of resection of injuries in parenchymatous organs. It has yielded good clinical results in liver and spleen surgery. Based on stringent indication, ultrasonosurgery can provide benefits to patient and surgeon in both oncosurgery and traumatology of liver and spleen.

Adolescent↗
PubMed1990

[Congenital secondary acute pleuroperitoneal prolapse].

In a case of a infant with congenital secondary acute enterothorax will represented, that congenital diaphragm defect must not be in evidence clinical directly postnatal. Dyspnoea, tachypnoea, cyanosis and intercostal drawing are the cardinal symptoms of the acute enterothorax. Clinical examination and X-ray technique of the thorax secure the diagnosis. Transthoracal and transabdominal surgical-entrance will weighed against one another, in which we recommended the abdominal surgical-entrance.

Hernia, Diaphragmatic↗
PubMed1989

Pharmacokinetic study of butyric acid administered in vivo as sodium and arginine butyrate salts.

Considering that butyrate-treated malignant cells can recover in a transitory fashion a non-cancerous phenotype, the authors carried out a pharmacokinetics study of butyric acid injected as sodium or arginine salts for possible antitumor therapies. In the case of 1-14C-labelled butyrate, the appearance of radioactivity in the blood of injected mice is rapid and some of it is maintained for relatively long periods in different organs, mainly the liver. However, no precision can be given about the structure of radioactive compounds in blood and tissues. Using gas-liquid chromatography, the authors studied the metabolism of butyrate in both animals and man. In mice and rabbits, the half-life is less than 5 min. In man, the butyric acid elimination curve can be divided into two parts corresponding to two half-lives: for the first (0.5 min), the slope suggests an accelerated excretion, while for the following (13.7 min), a slow plateau is observed. The rapid elimination of butyrate is a limiting factor for practical applications. However, the lack of toxicity supports its use in human therapy.

Adult↗
PubMed1989

[Basic studies of ultrasound surgery. VIII. Experimental animal studies of power ultrasound surgery of the swine pancreas].

The technique of the power ultrasound was tested in vitro and in vivo in 20 porcine pancreas. Simultaneous temperature measurements and laboratory tests do not produce any restriction. Enzymatic disorders were provable adequate to the clinical course. The ultrasonic effect guarantees a nearly riskless dissection in the layer. Joining processes, by adding Ligament-FIMOMED, produced a waterproof occlusion of parenchymal wounds. The cross-section of the pancreas with the pancreatic duct was sealed sufficiently. Also the jointed pancreato-jejunostomy remained sufficient. The reaction of the pancreatic parenchyma to the power ultrasound was small. A scarred metaplasia evolved immediately at the adhesive as a chronic atrophic interstitial pancreatitis. Only in case of occlusion of the pancreatic duct this alteration comprehended the whole pancreas.

Animals↗