N-acetyltransferase in human urothelium and bladder cell lines.
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Arylamine N-Acetyltransferase↗
Biomedical subjects
E Sim
Publications and source records attributed to E Sim.
Expression of N-acetyl transferase in a human monocytic cell-line, U937.
1. N-acetyl transferase (NAT) catalyses the acetylation of arylamine and hydrazine drugs and other xenobiotics. The activity of one isozyme (polymorphic NAT) varies amongst individuals but the other (monomorphic NAT) does not. 2. The human monocytic cell-line U937 transcribes the gene for monomorphic N-acetyl transferase. 3. Although the gene for polymorphic N-acetyl transferase is present in these cells, its expression is not detected. 4. It is concluded that U937 cells are a useful model for studying the metabolism of arylamines and hydrazines by human monomorphic N-acetyl transferase.
Acetyltransferases↗
[Personal construction of equipment for rapid change of roentgen cassettes in hip prosthesis interventions].
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Equipment Design↗
[Reposition of dislocated dorsal vertebral wall fragments in fractures of the thoracolumbar transition and the lumbar spine. Experience with 35 cases].
Pre- and postoperative CT scans of 35 patients with fractures of the thoracolumbar and lumbar spine (20 men and 15 women, with a mean age of 35 years), were evaluated with reference to the extent and shape of spinal stenosis. There were 24 patients with wedge-shaped fragments compressing the canal, the wedge being intact in 14 and broken in 10; 3 had fragmented wedges; and in 5, pedicular or arch fragmentation was combined with the dorsal vertebral fractures mentioned. Spinal stenosis was due to flexion-distraction injuries with angulation 3 patients, 1 of whom showed signs of dislocation and compaction. Fixation was done with the fixateur interne (F.I.) in 28 patients (combined with remodeling in 2), while 7 patients underwent plating with Teinturier plates and screws from the USI program. Burst fractures were most commonly encountered (25 patients) followed by flexion-distraction injuries of different types (10 patients). Instrumented reduction of the vertebral fragments was done in 24 patients. The effects of ligamentotaxis alone were relied upon in only 2 patients. Mean spinal canal narrowing amounted to slightly more than 50% (0.56) preoperatively. Residual narrowing postoperatively was just over 25% (0.26). In the patients followed up there was no evidence of secondary dislocation since the postoperative findings had been recorded. (ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Endoscopic management of bleeding peptic ulcers in Singapore: a multimodality approach.
Endoscopic haemostasis is becoming increasingly important in the management of bleeding peptic ulcers. In this study, rather than being confined to one modality of treatment, the endoscopist was allowed to customize the treatment according to the configuration of the ulcer, accessibility, and rate of bleeding in any particular patient. Fifty patients with actively bleeding peptic ulcers or stigmata of recent haemorrhage were treated endoscopically. Initial haemostasis was achieved in 48 (96%) patients. Eleven patients rebled of whom eight underwent repeat endoscopic treatment. Of these eight patients, three rebled of whom two required surgery. Permanent haemostasis was achieved in 43 of 50 patients (86%). The rate of surgery in the endoscopically treated group was 10%. There was one death due to causes not related to bleeding. The multimodality approach is a useful method of treatment in bleeding peptic ulcers, giving flexibility to the endoscopist in deciding on the best way to deal with the problem.
Adolescent↗
A multimodality approach to endoscopic treatment of bleeding peptic ulcers.
The role of endoscopic haemostasis in the treatment of bleeding peptic ulcers is widely studied. Many trials to date have compared one or more modalities against a medical control with variable results. To date, no single modality has been shown conclusively to be superior to others. As such, in this study we have not confined the endoscopist to one modality of treatment but allowed him to customize the method of endoscopic haemostasis according to the configuration, accessibility and rate of bleeding in any particular patient. Seventy-three patients with non-variceal upper gastrointestinal (GI) bleeding were admitted to the National University Hospital in Singapore between May 1, 1988 and April 30, 1989. All were gastroscoped and 48 were found to have chronic peptic ulcer. Twenty-nine (60%) with actively bleeding peptic ulcer or stigmata of recent haemorrhage (SRH) were treated endoscopically. Initial haemostasis was achieved in 27 (93%) patients. Seven patients rebled (26%) of which four underwent repeat endoscopic treatment. Of these four patients only one rebled again and required surgery. Permanent haemostasis was achieved in 23 of 29 patients (79%). The multimodality approach for the treatment of bleeding peptic ulcers gives the endoscopist flexibility in deciding on the best way to deal with a bleeding gastric or duodenal ulcer. Each instrument has its strengths and weaknesses and the right choice of instrument is often a critical factor especially in treating a bleeding ulcer in a situation where access poses a problem.
Adult↗
[Computerized tomography after surgical management of scaphoid fractures and pseudarthroses with implants in place. Method and results in 15 cases].
Fifteen patients having undergone open reduction and internal fixation for scaphoid fractures were later examined by computer tomography. Herbert-screws were used in nine cases and Ender-plates in four. In two cases, Ender-plates replaced a small fragment AO-screw as well as one Herbert-screw. Computer tomography of the wrist is not indicated on a routine basis, but whenever standard X-rays are unable to determine whether surgically treated fractures have healed or nonunion has been established. Patient cooperation is of utmost importance, if artifacts due to patient movement are to be avoided. To minimize implant artifacts, axial and radio-ulnar sections are employed; palmar-dorsal sections are advantageous whenever Ender-plates are involved.
Adolescent↗
Arylamine N-acetyltransferase from fast (C57BL6) and slow (A/J) N-acetylating strains of mice.
Many drugs and xenobiotics which are arylamines or hydrazines are metabolized by N-acetyltransferase. The enzyme is polymorphically expressed in humans and inbred strains of laboratory animals can be classified as fast or slow acetylating strains. N-Acetyltransferase has been partially purified from livers from a fast acetylator, C57BL6, and a slow acetylator, A/J, strain of mouse. The enzyme has been purified 1900- and 955-fold, respectively from the two strains, but still represents less than 20% of the total protein. These studies show that at least 5000-fold purification is required to isolate mouse liver N-acetyltransferase from either strain. During purification, N-acetyltransferase from both strains of mice elute identically as a single peak on ion exchange chromatography. Sucrose density gradient centrifugation of N-acetyltransferase shows partial separation of the activity from A/J mice into two peaks whilst the enzyme from C57BL6 mice migrates as one peak which is distinct from both the major and minor types of N-acetyltransferase in A/J mouse liver. The hydrodynamic parameters of N-acetyltransferase from C57BL6 mice and the major peak of N-acetyltransferase from A/J mice show that these enzymes are likely to be monomers of apparent molecular weights 33,000 +/- 1000 and 30,000 +/- 2000, respectively. These results indicate that the N-acetyltransferase isozymes in liver of these two strains of mice are not identical.
Acetyltransferases↗
[Hip tumor prosthesis--indication in a trauma center and results].
This is a report about six cases of replacement of the proximal femur by a cementless special prosthesis in modular system done in the Unfallkrankenhaus Wien-Meidling. One of the patients suffered by a lymphoma, three others had fractures caused by bone metastasis. One was a pertrochanteric fracture complicated by osteoporosis, and finally one fracture of the femur preceded by an insufficient implantation of a semitotal hip replacement. The hipsocket was supplied four times by a cementfree Polyäthylensocket, in one case a CLW-ring was implanted. Investigation showed that after a little more than two months the stump of femur became porous and by an average of eleven months the prosthesis was covered by bone. The complications were in one case an incomplete fracture of the diaphysis and in another case a luxation for three times. There are several indications for a tumor prosthesis: 1. Primary and secondary malignant tumors. 2. Bone metastasis with or without fractures. 3. Comminuted fractures complicated by various factors, e.g. osteoporosis. 4. Loosening of prosthesis with poor bone conditions or failed implantation of a standard prosthesis. Although the successes seem to be quite promisingly, this method should be applied in a quite differentiated way, as any retreat is nearly impossible, once started.
Aged↗
An optimal control model for maximum-height human jumping.
To understand how intermuscular control, inertial interactions among body segments, and musculotendon dynamics coordinate human movement, we have chosen to study maximum-height jumping. Because this activity presents a relatively unambiguous performance criterion, it fits well into the framework of optimal control theory. The human body is modeled as a four-segment, planar, articulated linkage, with adjacent links joined together by frictionless revolutes. Driving the skeletal system are eight musculotendon actuators, each muscle modeled as a three-element, lumped-parameter entity, in series with tendon. Tendon is assumed to be elastic, and its properties are defined by a stress-strain curve. The mechanical behavior of muscle is described by a Hill-type contractile element, including both series and parallel elasticity. Driving the musculotendon model is a first-order representation of excitation-contraction (activation) dynamics. The optimal control problem is to maximize the height reached by the center of mass of the body subject to body-segmental, musculotendon, and activation dynamics, a zero vertical ground reaction force at lift-off, and constraints which limit the magnitude of the incoming neural control signals to lie between zero (no excitation) and one (full excitation). A computational solution to this problem was found on the basis of a Mayne-Polak dynamic optimization algorithm. Qualitative comparisons between the predictions of the model and previously reported experimental findings indicate that the model reproduces the major features of a maximum-height squat jump (i.e. limb-segmental angular displacements, vertical and horizontal ground reaction forces, sequence of muscular activity, overall jump height, and final lift-off time).
Biomechanical Phenomena↗
[Dislocation of the thumb saddle joint as a rare sports injury].
This report deals with 4 dislocations of the carpometacarpal joint of the thumb during the period 1957-1983 as an injury caused by sports. 3 dislocations could be found in boxing, one was caused by a fall from a horizontal bar. All of them were closed: two times the dislocation was to the dorsal, one to the dorso-ulnar and one to the dorso-radial side. Closed dislocations do not require operative treatment. Reduction and immobilisation for four weeks in a plaster splint with inclusion of the thumb were sufficient, recurrence of the dislocation did not occur. Correct bandage and the use of effective boxing gloves are of great importance.
Adolescent↗
[Augmentation surgery of the anterior cruciate ligament using a carbon fiber band. Results of follow-up studies of 21 cases. I. (clinical aspects)].
Clinic and radiological follow-ups after implanting unidirectional carbon fibres in 21 cases (17 recent traumas, 1 older trauma and 3 chronic instabilities) approximately 34 months after operation. With the recent traumas we only found intraligamental ruptures or longitudinal fraying with ruptures of the femoral or tibial insertion. Postoperative plaster cast fixation for 6 weeks. Stability was examined by the "Arthrostress" (19 kp). In 11 cases no instability of clinical importance could be found, in 6 cases there was a +, in 3 cases a ++ and in 1 case a 3-plus instability.
Adolescent↗
[Results of magnetic resonance and computerized tomography studies of augmentation plastic surgery of the anterior cruciate ligament using carbon fibers. II].
19 patients out of those described in part I were examined by MRI and CT. We quote MRI as an excellent new mean of imaging without exposure to ionising radiation which renders sufficient information about the internal knee-structures without surgical invasion. The signal density for the neoligament as well intraarticular as in the "over the top"-position gives evidence for the ingrowth of mesenchymal structures. The MRI diagnosis was proved by histological examination in 2 cases. Very good correspondence between clinic examination and the CT-images could be found. On top of that the tibial drilling holes could be shown in an excellent way. The CT-scan is a fine instrument to judge the postoperative state of the anterior cruciate ligament. The density measurement inside and outside the bone gives evidence for mesenchymal growth inside the carbon fibre structure and the existence of a new natural ligament.
Anterior Cruciate Ligament↗
[Femoral fractures in osteodystrophy deformans (Paget's disease). Treatment results].
Between 1958 and 1986 21 fractures of the femur in Osteodystrophia deformans (Paget's disease) were treated at the accident hospital Meidling; of these 13 patients were female and 8 of male. The average age was 73.4 years. In two cases the basic illness was known, in 19 cases the fracture was the first manifestation of the illness. In 7 cases a polyostotic manifestation was evident. The fractures were localized as follows: 7 in the proximal, 7 in the middle, 1 in the distal third of the shaft, 5 subtrochanteric, 1 supracondylar. Apart from one subtrochanteric torsion fracture, all were flexure fractures without splinters. 19 fractures were stabilized by an operation: 17 by intramedullary nailing (with cerclage), 1 steep plate, 1 Ender nail. One case was treated by an extension, whereas in one case no operation was performed. The following complications were observed: one fracture of the steep plate, one delayed healing of the fracture after intramedullary nailing. No infections could be observed. In general, healing of the fracture in Osteodystrophia deformans does not seem to be delayed. The different possibilities of intramedullary nailing of the femur - possibly together with osteotomies to eliminate curvature - can be recommended for fractures in Osteodystrophia deformans.
Adult↗
[Indications for and technic in the surgical treatment of tibial shaft fractures with open epiphyseal grooves. A report of 63 cases].
The documentation relating to 63 surgically treated fractures sustained to the shaft of the tibia while epiphyseal growth plates were still in evidence (9 in isolation, 54 as fractures of the lower leg) between 1958 and 1983 was examined with respect to indications for the operation and the method selected. The average age of the patients was 12.9 years. There were 41 closed fractures and 22 open fractures varying in the degree of severity. Bending fractures predominated, with 42 cases, while the other 21 were spiral fractures. The causes were as follow: 32 traffic accidents, 28 sports accidents and 3 of other kinds. Stabilization was achieved either exclusively by wiring of the medulla or cerclage, or by a combination of both methods. Postoperative immobilization was ensured by means of a thigh cast for an average of 12 weeks. In 2 cases, intramedullary nailing was performed. The osteosynthetic material was removed early. Serious complications recorded were infection observed in 2 cases in connection with open fractures. Osseous union occurred in all fractures; no pseudarthroses developed. Absolute surgical indications, in our opinion, are third-degree open fractures, malreduction or instability of second- and first-degree open fractures, secondary dislocations after conservative initial treatment, soft-tissue damage and interposition. Relative indications are first and second-degree open fractures of the tibia and multiple trauma. Pathologic fractures were not considered in the follow up study, in which only 18 patients were examined: their average age was 13.7 (11-16) years.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Inhibition of the covalent binding reaction of complement component C4 by penicillamine, an anti-rheumatic agent.
D(-)-Penicillamine [D(-)-beta beta-dimethylcysteine] is an anti-arthritic drug, but its use is limited by adverse side effects, which include problems in immune-complex clearance. Complement is important as a source of inflammatory mediators in rheumatoid arthritis and is also involved in immune-complex clearance. Thus inhibition of the complement cascade would be likely to contribute to both the therapeutic and the toxic effects of penicillamine. It is shown that penicillamine and cysteine are potent inhibitors of the covalent binding of activated complement component C4 to immune complexes. [35S]Cysteine itself becomes covalently bound to C4b through the thioester site. Penicillamine and cysteine are more reactive with the C4A isotype than with the C4B isotype of the HLA class III protein C4. The limited amino acid sequence differences between C4A and C4B include a cysteine/serine interchange, and it is suggested that the cysteine residue in C4A contributes to the increased rate of reaction of C4A with the alpha-amino-beta-thiol compounds.
Anaphylatoxins↗
The epidemiology of the acute flank pain syndrome from suprofen.
Suprofen, a new nonsteroidal anti-inflammatory drug, was marketed in early 1986 as an analgesic agent. Until physicians began reporting an unusual acute flank pain syndrome to the spontaneous reporting system, 700,000 persons used the drug in the United States. Through August 1986, a total of 163 cases of this syndrome were reported. To elucidate the epidemiology of the syndrome, a case-control study was performed, comparing 62 of the case patients who had been reported to the spontaneous reporting system to 185 suprofen-exposed control subjects who did not have the syndrome. Case patients were more likely to be men (odds ratio, 3.8; 95% confidence interval, 1.2-12.1), suffer from hay fever and asthma (odds ratio, 3.4; 95% confidence interval, 1.0-11.9); to participate in regular exercise (odds ratio, 5.9; 95% confidence interval, 1.1-30.7), especially in the use of Nautilus equipment (p = 0.02); and to use alcohol (odds ratio, 4.4; 95% confidence interval, 1.1-17.5). Possible risk factors included young age, concurrent use of other analgesic agents (especially ibuprofen), preexisting renal disease, a history of kidney stones, a history of gout, a recent increase in activity, a recent increase in sun exposure, and residence in the Sunbelt. These were findings that were suggestive but did not reach conventional statistical significance. These findings are consistent with the postulated mechanism for this unusual syndrome: acute diffuse crystallization of uric acid in renal tubules.
Acute Kidney Injury↗
Endoscopic Nd-YAG laser in the palliative management of gastrointestinal malignancies in Singapore.
Thirty-five cases of advanced gastrointestinal malignancies were treated with the Nd-YAG laser for palliation of symptoms. Of the 35, 34 experienced good relief of their symptom. There were no major complications and minor complications occurred in four. The Nd-YAG laser was an efficacious means of providing symptomatic relief for such patients.
Aged↗