Biomedical subjects

N Ewald

Publications and source records attributed to N Ewald.

10 recordsLinked to original sources

PubMed2005

[Pyruvate kinase M2 (tumor M2-PK) as a screening tool for colorectal cancer (CRC). A review of current published data].

INTRODUCTION: Colonoscopy is currently supposed to be the best screening tool for colorectal cancer. However, the acceptance of the population is very poor although it has been included in screening programs in the German health system since 2002. Therefore, evaluation of additional screening tools seems to be of great interest. Recently testing for fecal occult blood (FOBT), genetic alterations or alterations in tumor metabolism (e.g., tumor M2-PK) are under investigation. METHODS: The use of M2-PK measurement in the feces has been reported in 6 studies until today. The data of these studies were analyzed and critically reviewed. RESULTS: The overall sensitivity of M2-PK is 77.9% concerning CRC. Specificity ranges from 74.3-83.3%. Overall sensitivity for adenomas is 45.9%, increasing to 61.1% for adenomas > 1 cm. A high percentage of positive results (90.4%) was also observed in patients with chronic inflammatory bowel disease. CONCLUSIONS: Compared to FOBT or genetic testing the M2-PK test seems to be superior for CRC screening. Concerning handling, effectiveness and analysis, M2-PK seems to be a good possibility for large scale-screening of colorectal carcinoma. It might even be used to detect larger adenomas. Elevated levels of M2-PK in patients with acute and/or chronic inflammatory bowel diseases are probably due to proliferation of epithelial cells and leucocytes in the inflammatory area.

Biomarkers, Tumor↗

PubMed2003

Role of redox signaling in the autonomous proliferative response of endothelial cells to hypoxia.

Endothelial cells exhibit an autonomous proliferative response to hypoxia, independent of paracrine effectors. In cultured endothelial cells of porcine aorta, we analyzed the signaling of this response, with a focus on the roles of redox signaling and the MEK/ERK pathway. Transient hypoxia (1 hour) stimulated proliferation by 61+/-4% (n=16; P<0.05 versus control), quantified after 24 hours normoxic postincubation. Hypoxia induced an activation of ERK2 and of NAD(P)H oxidase and a burst of reactive oxygen species (ROS), determined by DCF fluorescence. To inhibit the MEK/ERK pathway, we used PD 98059 (PD, 20 micromol/L); to downregulate NAD(P)H oxidase, we applied p22phox antisense oligonucleotides; and to inhibit mitochondrial ROS generation, we used the ubiquinone derivate mitoQ (MQ, 10 micromol/L). All three inhibitions suppressed the proliferative response: PD inhibited NAD(P)H oxidase activation; p22phox antisense transfection did not inhibit ERK2 activation, but suppressed ROS production; and MQ inhibited ERK2 activation and ROS production. The autonomous proliferative response depends on the MEK/ERK pathway and redox signaling steps upstream and downstream of ERK. Located upstream is ROS generation by mitochondria, downstream is NAD(P)H oxidase.

Animals↗

PubMed2003

Signaling of hypoxia-induced autonomous proliferation of endothelial cells.

Endothelial cells exhibit an autonomous proliferative response to hypoxia, independent of paracrine effectors. In cultured endothelial cells of porcine aorta, we analyzed the signaling and compared hypoxia with mitochondrial inhibition by rotenone. Particularly, roles of the mitogen-activated protein kinase (MAPK) kinase (MEK)/MAPK pathway and cytosolic Ca2+ were studied. Hypoxia resulted in increased proliferation by 65+/-2%. Hypoxia induced transient activation of p42 MAPK (phosphorylation rose from 11+/-5 to 51+/-7%), followed by translocation of p42 MAPK into the nucleus. The proliferative response was diminished after inhibition of the MEK/MAPK pathway by PD 98059 (20 microM) or UO 126 (10 microM) but not sensitive to 8-phenyl-theophillin (10 microM), an adenosine receptor blocker, nor to a neutralizing antibody for vascular endothelial growth factor (VEGF). Inhibition of intracellular Ca2+ release, capacitive Ca2+ influx, or removal of extracellular Ca2+ prevented hypoxic Ca2+ overload and the proliferative response. Suppression of cytosolic Ca2+ rise did not interfere with activation of p42 MAPK but abolished its nuclear translocation. Effects of hypoxia were mimicked by rotenone (10 microM. Transient hypoxic inhibition of mitochondria induces a proliferative endothelial response mediated through Ca2+-independent activation and Ca2+-dependent nuclear translocation of p42 MAPK. This proliferative response is independent of adenosine or VEGF.

Active Transport, Cell Nucleus↗

PubMed1987

[Surgical complications of renal transplantation in children. Retrospective study of 372 cases].

On the basis of a personal series of 372 cases of renal transplantation performed in children, half of whom presented congenital urinary tract malformations, the authors report 110 complications (29.6%). The most frequent complications were urological (14.2%), consisting essentially of fistulae (8.9%) and stenoses (3%). These were followed by vascular complications (6.4%) generally in the form of stenoses (4.8%) and rarely thromboses (1.1%). The authors also report the various local complications which were infectious (wall abscess, suppuration of the renal compartment), haemorrhagic (haematomas) or stones (stones forming on non-resorbable sutures) as well as 5 cases of lymphocele. The prophylaxis of these complications depends on the care taken in collection of the graft (en bloc removal of both kidneys), the restoration of the continuity of the urinary tract (as much as possible Lich-Gregoire extravesical uretero-vesical reimplantation), the vascular anastomoses (vascular dissection limited to a strict minimum), the choice of suture material (resorbable synthetic suture material) and the prevention of infection by systematic pre-, intra- and post-operative antibiotic therapy.

Child↗

PubMed1987

[Urinary diversions and intestinal grafts in renal transplantation in children. Report of 8 cases].

In a series of 400 transplantations, 8 children presented a severe lesion of the lower urinary tract requiring an intestinal graft to divert the urine or to replace the useless bladder: 4 cases of posterior urethral valves and 4 cases of neurogenic bladder. Four permanent urinary diversions and 4 bladder enlargements, including 3 temporary diversions, were performed. The sigmoid colon was used in 5 cases and the ileum was used in 3 cases. The preparation of the intestinal graft was always performed prior to the transplantation. The uretero-intestinal anastomosis included an antireflux device in 3 of the 8 cases. There were no deaths in this series. Three occlusions and 2 lymphoceles occurred in the immediate post-transplantation period, but were corrected by re-operation. Two cases of calculi occurred in the long term, one of which required operation. Moderate stenosis of the renal artery in one case resulted in systemic hypertension which was well controlled by medical treatment. An episode of acute pyelonephritis resolved rapidly with antibiotic treatment. Two cases of acidosis were corrected by salt supplementation. There was one case of early graft rejection on the 15th day and a delayed rejection after 18 months, leading to removal of the transplant. At the present time, 6 renal grafts function normally (75%) with a follow-up of 1 to 8 years.

Adolescent↗

PubMed1986

[Use of the intestinal graft in renal transplantation in children and adults].

Intestinal grafts as a means to external shunting of urine during renal transplant operation were described by W.D. Kelly as early as 1966. Since then 80 cases have been reported in the Anglo-Saxon literature. A total of 68 well-documented cases showed functional kidneys in 52%, complications in 42% and a 13% mortality rate. Between 1973 and 1985, of 400 renal transplant operations in children, an intestinal graft was used in 8 cases (2%) to provide 4 definitive external diversions and 4 enlargements or replacements of bladder. Indications for use were neurological bladder and posterior urethra valves. In all cases the graft was prepared before transplant operation. Enlargement of bladder requires good cervico-urethral function determined by previous study of a generally nonfunctioning bladder distal to an cutaneous ureterostomy. To avoid post-transplant urological effects the graft for enlargement or replacement is opened temporarily on to skin and closed several months after grafting. Follow up for 2 to 8 years showed 6 kidneys functioning normally, and 3 enlarged or replaced bladders out of 4 currently closed functioning satisfactorily. The 2 lost kidneys were rejected 2 weeks and 2 years respectively after the graft operation. There was no mortality or urological complication. The only surgical complications related to the intestinal graft were 3 early-onset occlusions treated successfully. Calculi formed in 2 cases, one being eliminated spontaneously at an early stage and the other, of late onset, requiring two operations. Metabolic or infectious complications were benign.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1982

[Diagnosis, prevalence, prognosis and treatment of the trophoblastic component in germinal tumours of the testis in the adult].

The authors report a series of 97 germinal tumours of the testis in the adult, studied first in terms of conventional histological data. Of 33 seminomas, 2 secreted HCG. The 5-year actuarial survival at stage I was 93%, and at stage II 75%. Stage II deaths revealed the existence of not purely seminomatous tumours. Amongst dysembryomas, half secreted HCG, with 3 histological groups: predominant choriocarcinomas, tumours with a trophoblastic component and "apparently pure" dysembryomas. The 3-year actuarial survival for dysembryomas was 90% at stage I and 58% at stage II. 51 patients of the series were studied retrospectively by sections with HCG peroxidase, a technique which reveals the intracytoplasmic synthesis of the hormone. Two types of cells have proved capable of such synthesis: syncytial cells, of syncytial-trophoblastic type, and small mononuclear cells. One third of seminomas and 90% of dysembryomas proved to have a trophoblastic component as demonstrated by HCG immunoperoxidases. All patients secreting HCG were HCG peroxidase positive. This equally applied to all patients with syncytial cells. Furthermore, all the indications are that HCG secretion is above all by the syncytial cells. From a diagnostic standpoint, any rise in beta HCG is synonymous with an HCG immunoperoxidase trophoblastic component. Detection of such a component using immunoperoxidase would seem to be essential for non-secreting tumours. From a prognostic standpoint, seminomas with a trophoblastic component are in fact dysembryomas and lymph node dissection should be performed, this being the only way of not missing a non-seminomatous metastasis. Therapeutically, pure seminomas are distinguished by the possibility of cure by radiotherapy. For all other tumours, orchidectomy must be followed by lymph node dissection. Subsequent treatment is decided on the basis of the results of the latter, with the exception of tumours with visceral metastases where chemotherapy must come first.

Adult↗

PubMed1982

[Teratoma of the renal sinus. Apropos of a Case].

The authors report a new case of teratoma of the renal fossa. Such tumours are rare. The case reported is unusual since it involved an older child and because the small lesion was located in the renal sinus and not in the parenchyma.

Child↗

PubMed1981

[Intraperitoneal bladder rupture (author's transl)].

On-duty radiologists should keep in mind some peculiar circumstances leading to intraperitoneale bladder rupture without fracture of pelvic bones. It is thus possible to identify the classical pattern of dog's ears topping the bladder, on the abdomen plain film, and the diagnosis may be confirmed by intravenous urography. An illustration is given by the reported case: a young man, after drinking too much, received a kick into the lap, followed by a severe pain and total urinary retention with a flat bladder.

Adult↗

PubMed1978

[The treatment of abdominal evisceration using the wire technique (author's transl)].

The insertion of wires in the preventive and curative treatment of abdominal evisceration is a variety of atraumatic open full-thickness sutures which are easy to carry out and particularly effective. In preventive treatment, they facilitate abdominal closure and avoid the risk of evisceration when large areas of skin are involved. In curative treatment, they form an abdominal "buckle" with the equal distribution of increased pressure over a large area, avoiding pulling on the sutures.

Humans↗