Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0262471 (ENT)
 5,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Optimal growth conditions have been established for production of heat-labile enterotoxin (LT) by both porcine and human strains of enterotoxigenic (ENT(+)) Escherichia coli. There were no unusual growth factor requirements, and some strains produced fairly high levels of LT in a basal salts medium containing 0.5% glucose if the pH was carefully controlled. Several amino acids markedly stimulated LT synthesis when added to the basal salts-glucose medium. Methionine and lysine were the most stimulatory for both human and porcine strains. Either aspartic acid or glutamic acid further enhanced LT synthesis in the presence of methionine and lysine, with aspartic acid being more stimulatory for porcine strains and glutamic acid more stimulatory for human strains. There were no apparent vitamin requirements and no unusual cations needed for toxin synthesis except that Fe(3+) was slightly stimulatory for porcine strains. The stimulation by Fe(3+) was observed only in the presence of the three amino acids, suggesting that the effect was indirect rather than on toxin synthesis. The carbon source also influenced the yield of LT. Glucose supported maximal synthesis, but other carbon sources which exhibit a high degree of catabolite repression also supported high levels of synthesis. Little or no LT was released below pH 7.0; therefore, because the pH drops during growth from 7.5 to 6.8, even in highly buffered media, it was necessary to adjust the pH to 8.0 to effect complete release of cell-associated toxin. The defined medium containing three amino acids reduced the amount of UV-absorbing material in culture supernatants about fivefold and increased LT activity for various strains from two- to fivefold over a complex Casamino Acids-yeast extract medium. Conditions found to be optimal for synthesis of LT were inhibitory for the heat-stable enterotoxin.
 ...
PMID:Nutritional requirements for synthesis of heat-labile enterotoxin by enterotoxigenic strains of Escherichia coli. 3

Formerly (1969) we have been able to demonstrate that during a lengthy inhibition of the DNA synthesis with 5-fluoro-uracil (FU), cells assemble just before, at the outset of, and within the S-phase. By taking off the inhibition, these cells start off together for the rest of the life cycle and pass the S, G2 and M phase like a wave. By the experimental condition given, the time required for passing the S phase was rather constant for all tissues. It generally took about 8 h. The sensitivity of cells to radiation depends on the current phase of their life cycle. Normally they are highly radiosensitive during the transition from G1 to S phase and within the G2 phase. Therefore we tried to improve the effectiveness of radiotherapy by radiating the synchronized cell population in the G2 phase. In clinical treatment we give an infusion with 1 g FU in 1000 ml 5.4% Glucose for 12 h. 8--9 h after the end of the infusion radiation will be applied (Betatron, individual doses: 500 rad). This treatment will be repeated until a total dose of 5000--6000 rad. Until now nearly 300 cases of patients treated in this way have been published. The 5 year-results show only in about 60% of the patients a fast reduction of the tumor. The long term results are unsatisfactory. Beside many other points the most important reason for these clinical results might be the individual length of the S phase of the tumors which prevents that radiation can be given exactly in G2 phase in each case. With mitotic-index determination, with cytophotometric investigations and the double labelling technique (3H- and 14C-Thymidine) we therefore tried to find an answer to the following questions: 1. How long is the DNA synthesis time in the individual case of human ENT tumors? 2. Does the application of FU influence the length of the S phase? 3. Will the synchronization-degree become higher by using other methods of cell cycle inhibition? With the above mentioned experimental methods we found that the length of the S phase in human tumor spreads from about 8--16 h in the individual case. The application of FU has no influence on DNA synthesis time. By using FU the degree of synchronization is about 2.5 in according to former experimental work and that of other authors. These results will be discussed in detail as well as the conclusion we draw from our experiments: to give radiation not in G2 but in G1/S of the cell cycle. Long-term observation of the patients and further animal experiments shall demonstrate whether this technique of synchronization therapy will improve the clinical results.
 ...
PMID:[Critical reflections to the problem of timing in the synchronization therapy of human malignant tumors. Mitotic-index determination, cytophotometric and radioautographic studies (author's transl)]. 57 2

The distribution of specific radiolabeled biological compounds in tumor tissues can be imaged by positron emission tomography (PET). The substance used is fluorodeoxyglucose, labeled with the positron emitter fluorine-18. This substance is partly trapped in tumor cells with increased glucose metabolism. This noninvasive imaging technique allows to assess quantitatively and in three dimensions the extent of metastatic disease in ENT cancer. The case presented illustrates the important value we foresee for this new imaging modality in the presurgical staging of cervical metastatic disease of ENT tumors. Sensitivity and specificity of the PET-FDG imaging technique for the loco-regional staging of ENT cancer are, according to preliminary results of an ongoing, prospective clinical study, very high.
 ...
PMID:[Positron emission tomography (PET) in the preoperative evaluation of cervical lymph node metastasis of ORL cancer]. 829 Aug 39

Disposable-type microbial sensors were prepared for the determination of biochemical oxygen demand (BOD). The yeast, Trichosporon cutaneum, was directly immobilized on the surface of miniature oxygen electrodes using an ultraviolet crosslinking resin (ENT-3400). The oxygen electrodes (15 mm x 2 mm x 0.4 mm) were made on silicon substrates using micromachining techniques. They were Clark-type two-electrode systems with-1021 mV applied to the working electrode. Typical response times of the BOD sensors were in the range of 7-20 min. At 20 degrees C, the sensors' dynamic range was from 0 to 18 mg/1 BOD when a glucose/glutamate BOD standard solution was used. The lower limit of detection was 0.2 mg/l BOD. This value was one order of magnitude lower than that of sensors previously reported. The sensors' operational lifetime of 3 days was satisfactory for a disposable type. The sensors' responses were reproducible to within 8% relative standard deviation. The BOD sensors' were applied to untreated and treated waste waters from industrial effluents and municipal sewage. BOD values determined using these sensors correlated well with those determined by the conventional 5-day BOD determination method.
 ...
PMID:Disposable sensor for biochemical oxygen demand. 898 29

A 6-year-old boy with a rare mitochondrial disease (MELAS: mitochondrial encephalopathy, lactic acidosis, stroke-like episodes) was presented to undergo adenoid resection and bilateral paracentesis. ENT surgery was performed without complications under general anaesthesia using propofol, fentanyl, and ventilation with nitrous oxide and oxygen. Routine intraoperative monitoring (ECG, noninvasive blood pressure, oxymetry and capnometry) was supplemented by frequent body temperature measurements and repeated laboratory analysis of venous blood gases, lactate, and glucose. Clinically, the postoperative course was uneventful and the boy was discharged from hospital on the first postoperative day. Signs or symptoms of malignant hyperthermia never occurred. Laboratory analysis only showed a remarkable serum lactate elevation postoperatively (6 mmol/l) which decreased on the first postoperative day (3.7 mmol/l). The present anaesthesiologic experiences with MELAS-syndrome are limited, and recommendations are mainly based on case reports. Careful preoperative physical examination with special regard to all available medical records, and anaesthetic management comparable with that in malignant hyperthermia susceptible resulted in an uneventful course in our patient. Pathogenetic aspects of mitochondrial diseases focussing on anaesthetic considerations are briefly discussed.
 ...
PMID:[Anesthesia in mitochondrial encephalomyopathies]. 1149 20

In alcohol-dependent in-patients, an adequate drug prophylaxis should be made in order to lower the degree of a developing alcohol withdrawal syndrome (AWS) or to prevent a life-threatening delirium tremens. Pre-condition of successful therapy is a precise diagnosis. In patients, the beginning of whose abstinence is known, carefully-targeted pharmacological interventions can prevent severe imbalances of neurotransmitters. Typical time courses of destabilisation of neural balances should be considered. Since there is no single drug which is able to influence various transmitter systems, normally the use of drug combinations is necessary. In ENT-patients, traumatologic patients and patients from the department of maxillo-facial surgery, screening methods based on a simply-structured questionnaire relating to information from the patient and his surroundings and selected laboratory parameters should be used. High-risk patients who could get an AWS or delirium tremens should be treated prophylactically during their oral premedication period. Important drugs for successful prophylaxis of an AWS are benzodiazepines, clonidin, magnesium and vitamin B 1. A close-meshed control of the glucose metabolism, electrolyte and acid-base balance should be performed. Neuroleptica can be used if there is any indication for their adjuvant use. In severe cases that require deep sedation or hypnosis, propofol or gamma-hydroxy-butyric acid should be used. Perioperative infusion of alcohol as a prophylactic agent against delirium tremens is regarded as an obsolete therapeutic measure for ethical reasons and because equally good or better results can be achieved by carefully-targeted drug therapy. Due to its easy use, however, the application of alcohol has not yet completely disappeared from the therapeutic spectrum.
 ...
PMID:[Can alcoholic withdrawal delirium be prevented?]. 1266 7

Significance for ENT-tumors. Molecular imaging with PET is based on the use of specific radioactive molecules as source of image contrast. In ENT-tumors mostly glucose and occasionally amino acid/protein metabolism were assessed with PET for tumor diagnosis. Thymidine salvage pathway and proliferation as well as tissue hypoxia are tested already in clinical studies and bear considerable potential for modulation of radiation ports and therapeutic response of cytoreductive regimens. This short review summarises actual clinical indications and potential of PET in ENT-tumors. For both nodal staging as well as detection of recurrent disease, sensitivity and specifity of FDG-PET were 80 - 100 %. FDG-PET proved to be superior to conventional imaging in most published studies. In CUP-syndrome the primary could be detected in 25 - 50 % of patients. Acquisition of PET and CT images in a combined scanner allow versatile PET based metabolic imaging in combination with high resolution and anatomical precise CT-based morphological imaging and thus combines advantages of both imaging modalities. Clinical as well as scientific potential of this functional metabolic and high resolution morphological imaging approach is high.
 ...
PMID:[Significance of PET for ENT-tumors]. 1519 80

The etiology of the atherosclerosis that occurs in diabetes mellitus is unclear. Adenosine has been shown to inhibit growth of rat aortic smooth muscle cells. Nucleoside transporters play an integral role in adenosine function by regulating adenosine levels in the vicinity of adenosine receptors. Therefore, we studied the effect of 25 mM d-glucose, which mimics hyperglycemia of diabetes, on adenosine transport in cultured human aortic smooth muscle cells (HASMCs). Although RT-PCR demonstrated the presence of equilibrative nucleoside transporter-1 (ENT-1) and ENT-2 mRNA, functional studies revealed that adenosine transport in HASMCs was predominantly mediated by ENT-1 and inhibited by nitrobenzylmercaptopurine riboside (NBMPR, IC(50) = 0.69 +/- 0.05 nM). Adenosine transport in HASMCs was increased by >30% after treatment for 48 h with 25 mM d-glucose, but not with equimolar d-mannitol and l-glucose. Kinetic studies showed that d-glucose increased V(max) of adenosine transport without affecting K(m). Similarly, d-glucose increased B(max) of high-affinity [(3)H]NBMPR binding, while the dissociation constant (K(d)) was not changed. Consistent with these observations, 25 mM d-glucose increased mRNA and protein expression of ENT-1. Treatment of serum-starved cells with the selective inhibitors of MAPK/ERK, PD-98059 (40 microM) and U-0126 (10 microM), abolished the effect of d-glucose on ENT-1. We conclude that d-glucose upregulates the protein and message expression and functional activity of ENT-1 in HASMCs, possibly via MAPK/ERK-dependent pathways. Pathologically, the increase in ENT-1 activity in diabetes may affect the availability of adenosine in the vicinity of adenosine receptors and, thus, alter vascular functions in diabetes.
 ...
PMID:D-Glucose upregulates adenosine transport in cultured human aortic smooth muscle cells. 1569 55

Central diabetes insipidus with an onset in adulthood is very rare. Unlike in children, central diabetes insipidus in adults is more frequently caused by inflammatory processes and neoplastic infiltrations that do not originate from the neuronal tissue than primary neuronal tissue tumours. Rare histiocytic neoplasias (Langerhans cell histiocytosis, xanthogranulomatosis and Erdheim-Chester disease) have a specific affinity to hypothalamus and the pituitary stalk not only in paediatric patients but also when occurring in adults. We describe 3 cases of central diabetes insipidus with an onset in adulthood. Diabetes insipidus was the first sign of Langerhans cell histiocytosis in 2 patients, and it was the first sign of Erdheim-Chester disease in one patient. MR imaging showed pathological infiltration and dilated pituitary stalks in all 3 patients. PET-CT proved useful in differential diagnosis, showing further extracranial pathological changes either on the basis of significant glucose accumulation or on the basis of CT imaging. The Langerhans cell histiocytosis in the first patient has also manifested itself as an infiltration of the perianal area with intensive accumulation of fluorodeoxyglucose (FDG) - SUV 8.6 and gingival inflammation indistinguishable from parodontosis. Histology of the perianal infiltrate confirmed Langerhans cell histiocytosis. Infiltration of the pituitary stalk disappeared from the MR image after 4 cycles of 2-chlordeoxyadenosin (5 mg/m2 5 consecutive days). The PET-CT of the 2nd patient showed only borderline accumulation of FDG in the ENT area, while simultaneously performed CT imaging showed cystic restructuring of the pulmonary parenchyma and nodulations consistent with pulmonary Langerhans cell histiocytosis. Bronchoalveolar lavage identified higher number of CD1 and S100 positive elements, consistent, once again, with pulmonary LCH also affecting pituitary stalk and ear canal. The PET-CT of the third patient showed increased activity in the long bones and ilium near the sacroiliac joint. Biopsy of the focus in the ilium confirmed foam histiocyte infiltration immunochemically corresponding to Erdheim-Chester disease. Additional imaging assessments revealed the presence of further signs of the disease. Pituitary infiltrate biopsy in this patient did not elucidate the diagnosis but resulted in complete panhypopituarism. Central diabetes insipidus in adulthood might be the first sign of so far undiagnosed extracranial disease, in our case of histiocytic neoplasias, and PET-CT has an excellent potential to detect extracranial symptoms of these conditions. Therefore, the high-risk pituitary stalk infiltrate biopsy should always be preceded by comprehensive examination aimed at identification of extracranial manifestations of the pituitary gland diseases.
 ...
PMID:[Central diabetes insipidus in adult patients--the first sign of Langerhans cell histiocytosis and Erdheim-Chester disease. Three case studies and literature review]. 2032 85

Taste is a chemical sense responding to chemical stimuli. In our daily practice as ENT practitioners or Neurologists we do come across patients complaining of taste disturbances. Tests for taste have to be performed regularly in the clinical centres as well as in neurological labs as a part of complete work up for neurotology cases. Assessment of taste sensation can be easily done in a neurological clinic by chemogustometry as described by Claussen. The stimuli used are chemicals, representative substances for the four qualities of sweet, salty, sour and bitter, in graded solutions. These semi-quantitative results are plotted on a pentagon scheme devised by Claussen. The points of the best results for glucose, sodium chloride, citric acid, phenylthio-urea and quinine then are connected with a coloured line. That gives a linked graphic structure, which can be read by the physician at one glance. Different patterns are obtained for normal taste, taste-blindness for phenylthio-urea, ageusia, partial ageusias for glucose, or sodium chloride or citric acid or quinine or their combinations and parageusias. In this article we present different patterns of taste disturbances depicted on the pentagon chart highlighting the easy interpretation of chemogustometry.
 ...
PMID:Qualitative and quantitative representation of taste disturbances: how we do it by pentagon chart. 2231 96


1 2 Next >>