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Biomedical subjects

M Langer

Publications and source records attributed to M Langer.

At least 397 records · Page 22Linked to original sources

[A simple method for imaging disorders of cardiac wall contraction using MRT].

By means of ECG triggering, it is possible to demonstrate various phases of cardiac action. It is then possible to derive a measure for cardiac function. The disadvantage of the method consists of the long measurement period required and the creation of movement artifacts. A method is discussed which would permit the demonstration of normal cardiac movement during a short time span and which reduces artifacts. In order to obtain optimum results, a new sequence of measurements is suggested. This is based on spin-echo sequences and can readily be used with any type of MRT apparatus.

Adult↗

Therapy of cytotoxic mushroom intoxication.

Poisoning by cytotoxic mushrooms (Amanita phalloides and related species) is associated with severe morbidity and a high mortality rate. Due to the difficulty of performing controlled studies and to the poor knowledge of the pharmacodynamics of toxins in human poisoning, there is considerable debate about appropriate treatment, particularly the feasibility and the efficacy of detoxification. Because circulating amatoxins can be detected in the serum of poisoned patients as long as 30 h after ingestion, a detoxification treatment should ideally increase the rate of toxin elimination in order to minimize the toxic exposure of highly susceptible cells, such as hepatocytes. We found forced diuresis to be the most effective procedure for toxin removal. Other techniques, such as plasmapheresis and peritoneal dialysis, proved much less useful for this purpose. The administration of cathartics, adsorbent agents, and gastroduodenal lavage, are indicated for preventing further absorption of toxins from the gut. An important part of therapy is early and vigorous volume replacement, to correct the severe hypovolemia which results from massive fluid loss during the cholera-like phase of intoxication. Use of this therapeutic approach in 53 patients with amatoxin poisoning resulted in a high survival rate and a low incidence of severe liver injury.

Adolescent↗

[Modification of the image quality of i.v. DSA by the iodine concentration of the contrast medium].

In randomised, double-blind clinical trials it could be demonstrated that in iv. DSA the image quality is reduced if the iodine concentration of the nonionic contrast medium iopromide is higher than 370 mgI/ml, the total amount of injected iodine being constant. This effect is due to the increased viscosity of contrast media containing a high iodine concentration per ml solution. The increased viscosity produces a longer transit time of the contrast material from the injection site to the target region. Due to this effect there is an increased dilution of contrast material with blood.

Cerebral Angiography↗

Fat as a factor affecting resolution in diagnostic ultrasound: possibilities for improving picture quality.

Fat and air are the main factors affecting quality by causing interference in ultrasound. Deterioration in resolution with increasing thickness of overlapping fat has been verified experimentally. The following factors have provided better resolution in experimental studies: large aperture transducers; compound technique (good axial resolution compensates for poor lateral resolution); compression of fat and location of the fat in the focus of the transducer; large beam width of the ultrasound signal. In a clinical study with 663 patients the influence of compression and compound technique on visualisation of abdominal structures was tested with a Combison 100 real-time scanner, Combison 202 compound scanner and the Octoson system. The retroperitoneal space was not demonstrated in 66 patients. Compression with the real-time transducer improved demonstration in 50% of studies (33/66), as compared to 20% (19/66) with the compound technique. Resolution was affected by velocity errors and reflection in 30% of cases (19/66) examined with the compound technique.

Adipose Tissue↗

[Pulmonary function during a 10-day successful extracorporeal CO2 elimination in acute respiratory failure. Case report].

Extracorporeal CO2-removal (ECCO2-R) with low-frequency positive-pressure ventilation (LFPPV) may relieve the acutely injured lung from the burden and the risks of excessively high ventilatory minute volumes and airway pressures. It was the purpose of this study to document the evolution of lung function during clinical ECCO2-R with special emphasis on extravascular lung water. ECCO2-R was applied in a 21-year-old female patient suffering from severe post-traumatic infectious adult respiratory distress syndrome. The indication for ECCO2-R was based on the following findings: total static lung compliance 25 cm X cm H2O-1; arterial pO2 50 mm Hg with an inspiratory oxygen concentration of 100%; intrapulmonary right-to-left shunt over 50% of the cardiac output; and extravascular lung water 24 ml X kg-1 (normal 4.5-7 ml X kg-1). ECCO2-R was shown to provide satisfactory conditions for improving the above-mentioned abnormal parameters of pulmonary function. Pressure-limited low-frequency mechanical ventilation allowed successful management of several pneumothoraces with bronchopleural fistulas which occurred during the procedure. It is concluded that these complications of positive airway pressure would have led to the patient's death under the conditions of conventional mechanical ventilation.

Adult↗

Serum thyroglobulin levels in the diagnosis and follow-up of subacute 'painful' thyroiditis. A sequential study.

Serum thyroglobulin (Tg) levels were elevated in 92% of 38 patients with subacute "painful" thyroiditis in the early stage, independent of the extent of the disease and thyroid hormone concentrations. After two months of corticosteroid treatment, serum Tg levels were significantly decreased in 25 patients who could be rechecked, compared with the levels in the acute phase, although higher than those in our normal control subjects. Twelve of 25 patients underwent sequential measurements of Tg for three to four months, during the disease and after recovery. In ten the initially elevated values decreased rapidly to normal and were maintained for approximately 20 days. Then they rose gradually, peaked about 60 days after disease onset, then returned slowly and permanently to normal. In one patient who had a clinical relapse during the plateau phase, the Tg level also increased markedly and abruptly. Therefore, serial measurements of serum Tg can help in diagnosing and monitoring subacute "painful" thyroiditis.

Adolescent↗

[Intravascular rheologic changes following the administration of a contrast medium--animal experiment studies].

An angiographic animal study showed that hyperosmolar, ionic contrast media with a low viscosity produce the greatest increase in blood flow and the shortest diagnostically useful contrasting time of the vessels. The longest vessel contrast time and the smallest secondary increase in blood flow is seen for a nonionic, nearly isotonic contrast medium with a somewhat higher viscosity.

Angiography↗

The main determinants of nitrogen balance during total parenteral nutrition in critically ill injured patients.

Factors influencing nitrogen balance during total parenteral nutrition have been investigated in 34 critically ill injured patients studied during the first 6 days after trauma. Basal nitrogen balance was severely negative (-0.26 +/- 0.12 (SD) g X kg-1), but improved consistently during treatment. Nitrogen intake proved to be the major determinant of a positive, or less negative, nitrogen balance, only secondarily followed by total energy intake corrected to predicted basal energy expenditure, according to multiple regression analysis. The amount of non-protein calories and the non-protein calorie to nitrogen ratio appeared to have little significance on nitrogen balance, when corrected for the two former variables.

Adolescent↗

The role of total static lung compliance in the management of severe ARDS unresponsive to conventional treatment.

A group of 36 patients with severe adult respiratory distress syndrome (ARDS) meeting previously established blood gas criteria (mortality rate 90%) became candidates for possible extracorporeal respiratory support [low frequency positive pressure ventilation with extracorporeal CO2 removal (LFPPV-ECCO2R)]. Before connecting the patients to bypass we first switched the patients from conventional mechanical ventilation with positive end expiratory pressure (PEEP) to pressure controlled inverted ratio ventilation (PC-IRV), and then when feasible, to spontaneous breathing with continuous positive airways pressure (CPAP). Forty eight hours after the patients had entered the treatment protocol, only 19 out of the 36 patients in fact required LFPPV-ECCO2R, while 5 were still on PC-IRV, and 12 were on CPAP. The overall mortality rate of the entire population was 23%. The only predictive value of success or failure of a particular treatment mode was total static lung compliance (TSLC). No patients with a TSLC lower than 25 ml (cm H2O)-1 tolerated either PC-IRV or CPAP, while all patients with a TSLC higher than 30 ml (cm H2O)-1 were successfully treated with CPAP. Borderline patients (TSLC between 25 and 30 ml (cm H2O)-1) had to be treated with PC-IRV for more than 48 h, or were then placed on LFPPV-ECCO2R if Paco2 rose prohibitively. We conclude that TSLC is a most useful measurement in deciding on the best management of patients with severe ARDS, unresponsive to conventional treatment.

Adolescent↗

[Transplant occlusion following aortofemoral bifurcation bypass: causes, therapeutic measures and results].

35 patients with graft thrombosis following aortobifemoral bypass grafting were analysed retrospectively (1971-1983). In 24 of these patients aortobifemoral bypass graft was performed in our own hospital and the thrombosis rate was 9.1%. 40 bypass branches and 54 graft occlusions were involved. Late occlusions were more common (75.9%), occurring after an average time interval of a little more than 5 years. Inadequate peripheral run-off with progression of the atherosclerosis was the cause in 37.5%. In 40.0% the site of occlusion was in the proximal segment of the graft, where kinking related to anastomotic technical problems played a major role. The transfemoral ring or balloon thrombectomy was successful in 45.5%. In 24.2%, however, this had to be combined with a bypass procedure (femoropopliteal or femorocrural). A change of the graft was indicated in 48.5%, but this was considered too risky in 30.3% (extraanatomic bypass: change of graft = 1.7:1). In the case of poor distal run-off a peripheral corrective procedure was a must for graft patency. In every second patient this could be achieved by profunda revascularisation. Occlusions at the central bifurcation segment are better prevented by proper anastomotic techniques. A graft with a short main trunk anastomosed to the high infrarenal aortic segment ensures a safer anastomosis and a proper position of the graft branches with little possibility of kinking. Since the routine use of this method a graft thrombosis caused by central technical problems has not been seen.

Aged↗

Value of computed tomography in the diagnosis of intrapulmonary arteriovenous shunts.

A case of intrapulmonary arteriovenous malformations (AVMs), its diagnosis, and a literature review is presented. We consider the diagnosis of intrapulmonary AVMs by noninvasive methods, such as plain chest radiography, fluoroscopy, computed tomography (CT), and particularly dynamic CT imaging of the thorax. To determine hemodynamic factors, oxygen consumption, oxygen saturation and blood gas analyses of the central pulmonary circulation digital subtraction angiography as well as invasive pulmonary angiography are needed.

Adult↗

[Significance of ovulatory age in the pathogenesis of ovarian cancer].

The impact of several parameters influencing ovulation upon the epidemiology of ovarian cancer was assessed retrospectively on 129 patients. The same number of women with other gynaecological diagnoses was used as controls. "Ovulatory age" was significantly higher in patients than in controls. Relative risk to develop ovarian cancer decreased with the increase of "protected time". Blood-group A was found considerably more frequently, blood-group 0 less frequently in patients than in the normal population.

ABO Blood-Group System↗

[Diagnostic significance of intravenous digital subtraction angiography of the supra-aortic extracranial vascular system. Comparative study of i.v. DSA and plain film angiography].

Digital intravenous subtraction angiography (DSA) and conventional film angiography were used to evaluate the diagnostic reliability of DSA-examinations. In 90% of 650 DSA-angiogramms the image quality was diagnostic. For 124 carotid angiographies a comparison of both methods was possible and gave a sensitivity of 87%, a specificity of 96% and an accuracy of 90% for the DSA examinations. The authors believe that digital subtraction angiography is suitable as a screening method for supraaortal vascular occlusive diseases.

Aged↗

Serum thyroglobulin in patients with autonomous thyroid nodules.

To investigate further the relationship between thyroid hormones and thyroglobulin (TG) secretion, total and free thyroid hormone levels, TSH and its response to TRH and serum TG concentrations were determined in 61 patients with solitary autonomous thyroid nodules. Thyroid function varied widely from euthyroidism to clearcut thyrotoxicosis. Serum TG levels were significantly higher in patients than in normal controls. Individually they were above the normal range (greater than 50 ng/ml) in 95% of the patients, as well as in those with normal total and/or free thyroid hormone levels. Patients with high total and/or free thyroid hormone levels had higher TG concentrations than euthyroid patients. TG concentrations were significantly correlated with FT3 values. They were higher in patients in whom TSH was unresponsive to TRH than in the responsive groups. TG was also slightly higher in patients with hot nodules than in those with warm nodules. These data seem to indicate that TG is secreted along with thyroid hormones in the absence of any stimulatory action. It also is a sensitive index of thyroid hyperfunction. Twenty patients were controlled 6 months after nodulectomy. TG levels, though significantly lower than in the preoperative state, were still higher than in normal subjects. This increase was attributed to persistent hyperthyroidism in two patients only. The observation that the increase in TSH after TRH stimulation in post-operative patients was greater than that found in normal controls led us to believe that in most cases the high TG levels after surgery are due to stimulation of the normal thyroid tissue by rebound TSH secretion.

Adolescent↗