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Biomedical subjects

H Becker

Publications and source records attributed to H Becker.

At least 217 records · Page 12Linked to original sources

Analysis of proteins that interact with the IL-2 regulatory region in patients with rheumatic diseases.

In order to investigate transcriptional regulation of lymphokine genes in rheumatic diseases, peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) were analysed for expression of DNA-binding proteins. Nuclear extracts prepared from unstimulated and mitogen-activated cells were studied for their ability to bind to 32P-labelled oligonucleotides containing the AP-1, NF-AT, NF-B and CD28RC sites of the IL-2 promoter. Using gel mobility-shift assay, detection of protein binding to the AP-1 site was reduced in SLE compared with controls. NF-AT binding activity was enhanced in all groups of patients, and was associated with measures of disease activity in RA. In addition, SSc patients showed increased NF-kappa B binding activity. Altered patterns of DNA-binding proteins suggest disturbed intracellular signalling which may contribute to abnormal lymphokine production in rheumatic diseases.

Adult↗

Intrathoracic pressure changes and cardiovascular effects induced by nCPAP and nBiPAP in sleep apnoea patients.

The effect of nasal continuous positive airway pressure (nCPAP) and nasal bi-level positive airway pressure (nBiPAP) on intrathoracic pressure and haemodynamics during wakefulness was studied in a group of nine patients with severe sleep apnoea. No patient took cardiovascular medication. Patients were studied with a Swan Ganz catheter, an arterial line and an oesophageal balloon. nCPAP and nBiPAP were applied in the following pressure sequence: 5, 10 and 15 cm H2O of CPAP and 10/5 and 15/10 cm H2O of nBiPAP. Measurements were made at the end of a 5-min period at each pressure level. Intrathoracic pressure was noted to increase to a level of approximately 50% of the pressure delivered at the mask. At a CPAP of 10 cm H2O and above, as well as at BiPAP of 10/5 or higher, there was a decrease in cardiac output (CO) and cardiac index (CI). CI fell below the normal value in two of the patients. Transmural pulmonary artery pressure (PPAtm) decreased at a CPAP of 15 cm H2O and at both BiPAP levels. Transmural right atrial pressure (PRAtm) decreased at both BiPAP levels. There were no differences in CO, CI, PPAtm and PRAtm between nCPAP and nBiPAP at equal inspiratory pressures. SaO2 increased during BiPAP 15/10 cm H2O, whereas heart rate and arterial blood pressure did not change significantly. The data presented here are consistent with the literature on positive end-expiratory pressure (PEEP) applied via intratracheal tube and are likely to be due to a reduced venous return. It is concluded that nasally applied positive pressure may have acute negative effects on cardiac function in patients with sleep apnoea.

Journal Article↗

Ventilatory response to isocapnic hyperoxia.

Breathing O2 for up to 1 h has been shown to either not influence or slightly increase (6-13%) minute ventilation. However, end-tidal PCO2 was not kept constant in these experiments. In nine healthy men, we studied the ventilatory, blood pressure, and heart rate responses to 30 min of normobaric hyperoxia (50% O2) at isocapnic conditions. Hyperoxia led to a 60% increase in mean minute ventilation (P = 0.002), largely due to an increase in mean tidal volume from 0.66 +/- 0.04 (SE) to 0.88 +/- 0.05 liter (P = 0.007). Fifteen minutes after the termination of hyperoxia, minute ventilation was still increased (P = 0.02) compared with baseline, although it was reduced compared with hyperoxia (P = 0.02). Arterial blood gas analyses in six subjects before and during hyperoxia showed an increase in arterial PO2 and O2 saturation but no change in arterial PCO2 or pH. Hyperoxia induced no changes in arterial blood pressure or heart rate. We conclude that 1) isocapnic hyperoxia stimulates respiration markedly, an effect that is approximately five times higher than previously measured; 2) the increase in ventilation induced by hyperoxia does not affect arterial blood pressure and heart rate; and 3) in experiments using hyperoxia, its effect on breathing and subsequently on PCO2 has to be taken into account.

Adult↗

Evaluation of liver function tests to predict operative risk in liver surgery.

Despite numerous studies in the past it is not possible yet to predict postoperative liver failure and safe limits for hepatectomy. In this study the following liver function tests ICG-ER (indocyaninegreen elimination rate), GEC (galactose elimination capacity) and MEGX-F (monoethylglycinexylidid formation) are examined with regard to loss of liver tissue and prediction of operative risk. Liver function tests were assessed in 20 patients prior to liver resection and on the 10th. postoperative day. Liver and tumor volume were measured by ultrasound and pathologic specimen and the parenchymal resection rate was calculated. In patients without cirrhosis (n = 10) ICG-ER and MEGX-F remained unchanged after resection, GEC was reduced but did not correspond to the resection rate. Patients with cirrhosis (n = 10) had a significantly lower ICG-ER and GEC before resection than patients without cirrhosis. After resection these tests were unchanged. Patients with liver related complications and cirrhosis (n = 5) had lower ICG-ER and GEC than patients with cirrhosis and no complications. In the postoperative course all liver function tests in these patients were significantly lower compared to preoperative results. Comparing liver function tests ICG serves best to indicate postoperative liver failure. Liver function tests do not correspond with loss of liver tissue.

Galactose↗

Reversal of sinus arrest and atrioventricular conduction block in patients with sleep apnea during nasal continuous positive airway pressure.

Sinus arrest and atrioventricular (AV) block have been demonstrated in as much as 30% of patients with sleep apnea (SA). The reversal of heart block after tracheostomy has been shown. Nasal continuous positive airway pressure (nCPAP) now is widely used as the treatment of SA, but little data are available on the effect of nCPAP on heart block in patients with SA. During a 17-mo period 239 patients were found to have SA in an ambulatory study. Heart block was identified in 17 (16 male, one female) of these patients. Standard polysomnography and two-channel long-term ECG before and during nCPAP therapy were performed in order to assess the effect of nCPAP on SA and heart block. Mean age of the 17 patients was 50.7 yr (range, 27 to 78 yr), mean respiratory disturbance index (RDI) was 90/h (SD +/- 36.1) before nCPAP and 6/h (SD +/- 6.2) on the second treatment night. The number of episodes of heart block during sleep decreased significantly (p < 0.001) from 1,575 before therapy to 165 during nCPAP. In 12 patients (70.6%) heart block was totally prevented by nCPAP. In another three patients, there was a 71 to 97% reduction in the number of episodes of heart block on the second treatment night, and in two of them a complete reversal occurred thereafter. Two patients exhibited an increase in block frequency during nCPAP, which was reversed after 4 wk of nCPAP in one but persisted in the other.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[The value of 3D video endoscopy for surgical procedures].

We discuss the problems of spatial perception that arise by the transmission of endoscopic surgery by traditional video systems and analyse the improvements that can be achieved by two- und three-dimensional systems. Starting with a description of the physics of vision and the principles of two- and three-dimensional imaging, we demonstrate the importance of optimal adaptation of technology to the natural perception processes of the observer. In this context we review critically the technology that is presently available. Only stereoscopic video technology with 'shutter glasses' provides the observer with the spatial information that is of such decisive importance for minimally invasive surgery. Finally we discuss new technical developments that further improve three-dimensional vision in endoscopy, such as a 3D video module that is small enough to be used intracorporally.

Computer Peripherals↗

[Errors and risks in administration of nasal respiratory therapy of obstructive sleep apnea].

Over a period of 1 year we observed in our sleep laboratory in 502 patients with sleep related breathing disorders several side effects of positive airway pressure treatment, furthermore we observed in 5 patients unexpected dangerous complications due to the application of CPAP and BIPAP. We observed mask leakages which lead to insufficient positive airway pressure-therapy and an occurence of short central apnoeas during NREM sleep after arousal or wakefulness periods. Finally we observed in 5 patients during treatment with CPAP and BIPAP an unexpected appearance of long central apnoeas up to 110s and central hypoventilations up to 5 min accompanied by excessive hypoxaemia (SaO2 < 20%) and cardiac arrhythmias. We conclude that in the treatment of obstructive sleep apnoeas we have to expect in 1-2% complications of the positive airway pressure treatment itself. To avoid life endangered complications the first night application should be done only in conventional sleep laboratories.

Equipment Failure↗

[Parameters for determining the effective treatment pressure in nCPAP therapy of sleep apnea].

We evaluated the accuracy of single parameters from the polysomnography in establishing the effective nCPAP treatment pressure in order to possibly economize pressure adjustment. In four patients (pts) a standard polysomnography was performed. 67 segments of 30-60s in duration, showing different typical types of breathing disturbances or normal breathing were selected. The segments were divided into 5 horizontal parts consisting of only one of the following signals: SaO2, snoring, mask pressure, esophageal pressure (Poes) and respiratory movements (RC + Abd). A second investigator then classified these 335 one lead recordings without knowing the complete segment. The classification based on the complete segment compared to that based on only one parameter gave an identical result in 44.8% (SaO2), 61.2% (Poes), 64.2% (RC + Abd), 80.6% (sonoring) and 82.1% (mask pressure) respectively. 97% of the complete segments were classified identically by both investigators. Each of the studied parameters alone was not adequate in establishing the correct pressure level. SaO2 corresponds least, mask pressure and snoring best to the classification based on all parameters.

Air Pressure↗

[Machine-assisted detection of individually effective minimal CPAP pressure using the Vitalog HMS 5000 monitor].

UNLABELLED: Continuous positive airway pressure ventilation (CPAP) has been proven to be highly effective in the elimination of sleep-related breathing disorders (SRBD) in the last couple of years. The titration of the effective airway pressure should be carried out under continuous polysomnographic supervision in the sleep laboratory. The CPAP ventilation may result in potential hazards through the positive airway pressure and each patient needs an individually adjusted pressure for therapy. In a prospective study we investigated under polysomnographic supervision the effectivity and the hazards of a machine-controlled CPAP calibration in 22 male patients (pts) (age: 53.6 +/- 8.9 years, BMI: 29.9 +/- 5.0 kg/m2) with obstructive SRBD (RDI: 50.6 +/- 1/h). Automatic CPAP-calibrations were carried out using the Vitalog HMS-5000 monitor and the Respironics BiPAP-STD ventilator. An algorithm determined the cyclical changes of the airway pressure. The following night we controlled the assessed pressure through manual adjustment during conventional polysomnography. RESULTS: The CPAP-levels assessed through the automatic calibrations (8.36 +/- 2.36 cmH2O) showed in 19 pts a good agreement with the CPAP-levels of the control nights (8.15 +/- 2.36 cmH2O), the difference was statistically nonsignificant (p < 0.5). The CPAP-levels of the automatic titrations and the control nights agreed exactly in 12 pts (63%). 3 pts of the 22 failed the automatic CPAP-titration process because of functional or psychical reasons. 14 pts (64% of 22 pts) showed a good functional tolerance to the cyclical changes of the airway pressure. 3 pts were unable to fall asleep under the increasing airway pressure, but after falling asleep at a constant pressure of 2 or 4 cmH2O they could tolerate the automatic pressure titration. A reset of the actual pressure to the baseline was necessary in 13 pts to enable them falling asleep, in 2 pts because of increase of the airway pressure due to movement artifacts, in 2 pts because of central apneas and in one patient because of ventricular extrasystoles. 35 increases of the baseline level (48% of altogether 73 increases) occurred due to clinically irrelevant desaturations. We found a direct hazardous effect of the machine-controlled CPAP-titration (central apneas, secondary alveolar hypoventilation, ventricular extrasystole) in 7 pts with chronic obstructive pulmonary disease and/or cardiovascular disorder. CONCLUSION: The machine-controlled CPAP-titration should be carried out only in a selected group of patients. Nevertheless, despite of the good agreement of the assessed pressure levels with the polysomnographic controls, this method seems to be not suitable for the clinical routine because of its potential hazards and contraindications in high risk patients.

Adult↗

[Continuous single layer anastomosis as the standard procedure in the gastrointestinal tract].

The continuous suture by single layer technique is suitable for all anastomoses in the gastrointestinal tract. Anastomotic dehiscence rate has been examined and amounts 1.7% for anastomoses in the stomach 0.3% in the small intestine and 2.8% in the colon. In comparison with other techniques the anastomosis is safe and easy to learn. Costs and time of surgery can be reduced significantly.

Anastomosis, Surgical↗

Transhiatal oesophagectomy compared with transthoracic resection and systematic lymphadenectomy for the treatment of oesophageal cancer.

OBJECTIVE: To compare the results of transhiatal oesophagectomy with those of transthoracic resection with systematic two field en bloc lymphadenectomy in the treatment of carcinoma of the oesophagus. DESIGN: Prospective open (non-random) study. SETTING: University hospital, Germany. SUBJECTS: 87 patients with carcinoma of the oesophagus of whom 46 underwent transhiatal, and 41 transthoracic resection. MAIN OUTCOME MEASURES: Morbidity and short and long term mortality. RESULTS: The type of operation was chosen on clinical grounds, and the groups were comparable except for site and type of tumour, and nodal stage. The hospital mortality was 7/46 (15%) in the transhiatal group and 4/41 (10%) in the transthoracic group. The most common complication was anastomotic leak (23/46, 50%, compared with 10/41, 24%, p = 0.014), followed by major pulmonary complications (16/46, 35%, compared with 12/41, 29%), and cardiac complications (12/46, 26% compared with 11/41, 27%). Median survival was 350 days in the transhiatal group and 378 days in the transthoracic group. The percentage survival after one, two, and three years in the two groups was 48 and 55, 26 and 18, and 21 and 17, respectively. There were no significant differences in short or long term mortality. CONCLUSION: We have been unable to show that the oncologically more radical procedure (transthoracic resection with systematic two field en bloc lymphadenectomy) results in longer survival, but we have shown that it can be done with similar morbidity and short term mortality. Because it is possible to stage the disease exactly with a transthoracic resection, and because published reports from other centres have hinted at improved prognosis after it, we shall continue to do the operation for suitable patients.

Adult↗

[The most frequent depressive disorders. Diagnosis, classification, symptoms and prognosis].

The most frequent depressive disorders--anxiety and panic syndrome, dysthymic (neurotic) illnesses and reactive depressive adjustment disorders--were classified according to the new international codes. It was also explained that theoretical aetiological assessment principles had to be replaced by duration and symptomatology as operational criteria. Further, a table was elaborated for diagnosing depressive syndromes from an intrapsychic, social and somatic standpoint. Epidemiological aspects of both German and international studies were discussed and prognostic factors highlighted.

Cross-Sectional Studies↗

[Effect of resection or duct drainage on glucose stimulated beta cell function in chronic pancreatitis].

Chronic pancreatitis (CP) leads to deterioration of the endocrine pancreatic function by fibrotic destruction. The aim of the present study was to investigate whether resection or duct drainage in patients with CP would have a direct impact on the pancreatic beta cell function. An intravenous glucose tolerance test (IVGTT) was performed before, after and in some cases 3 months after operation in ten patients each of whom had been treated by either resection or duct drainage. Three patients undergoing pancreatic resection for cancer served as controls. Beta cell function was assessed by glucose elimination (K-values), insulin and C-peptide response. K-Values in patients with CP were not significantly influenced after resection (1.93 +/- 0.78/2.13 +/- 0.72; n.s.) or drainage (1.26 +/- 0.47/1.54 +/- 0.58; n.s.) but reduced in all three tumor patients (2.23 +/- 0.55/1.23 +/- 0.43). The initial insulin response [microU/ml] in CP patients was also not altered after resection (19.7 +/- 17.3/16.0 +/- 18.2; n.s.) or after drainage (16.7 +/- 16.5/13.0 +/- 9.0; n.s.), whereas all three resected tumor patients showed reduced values (42.9 +/- 15.7/17.5 +/- 3.8). Stimulated C-peptide synthesis [ngmin/ml] was not substantially lowered in patients resected for CP (90.5 +/- 85.6/73.8 +/- 48.9; n.s.) or in the drainage group (121.3 +/- 67.5/98.0 +/- 57.2; n.s.), but this parameter was decreased in every tumor patient postoperatively (157.8 +/- 66.9/125.1 +/- 69.6). Resection in patients with chronic pancreatitis did not inevitably result in loss of beta cell function. Parenchyma-preserving drainage procedures had no measurable advantage in this respect.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗

Patterns of skull base fracture: a three-dimensional computed tomographic study.

Three-dimensional (3D) computed tomographic (CT) reconstructions were studied retrospectively in 14 patients with skull base fractures. Our aim was to assess the clarity of visualisation and pattern of these fractures. The reformations were obtained from 3 mm thick two-dimensional (2D) CT images. The 2D data stored on optical discs were retrieved and reformatted using the scanner's software. The 3D technique could demonstrate the presence of fractures as well as 2D images. It was of special value in defining the depth and extent of fractures in the floor of the cranial fossae. Undisplaced and displaced fractures could both be demonstrated. Fractures in the anterior fossa run diagonally towards the midline and then cross the cribriform plate of the ethmoid bone. Fractures of the middle fossa run obliquely anteroposterior. Fractures in the lamina papyracea and cribriform plate were difficult to reconstruct due to the thinness of these bones and threshold definitions. The volume of the 3D block determines the angles suitable for viewing the fractures. In spite of present technical difficulties, the 3D images are of greater anatomical and diagnostic value, particularly in anterior fossa fractures. There is no additional radiation risk to the patient, since reconstructions are made from routine 2D images.

Adolescent↗

Bacillus cereus in infant foods and dried milk products.

Dried milk products and infant food are known to be frequently contaminated with Bacillus cereus. Sources of the organism and its behaviour in the product and in the equipment during processing are discussed. With regard to the incidence of B. cereus in infant food, 261 samples distributed in 17 countries were collected and examined for its B. cereus content. Fifty-four percent of the samples were contaminated with B. cereus reaching levels from 0.3 to 600/g. Counts higher than 10/g were found in only 27 samples (10%). Most of the positive samples (44%) contained 0.3 to 10 B. cereus/g. Four samples (1.5%) were contaminated with more than 100 organisms/g reaching a maximum level of 600 B. cereus/g. When classified into different types of products about 50% of the infant formulae based on milk, the follow-on formulae and the weaning foods were contaminated with B. cereus as well as 69% of those based on soy protein and 92% of the special dietetic foods. Compared to our earlier studies from 1982/83, the percentage of contaminated samples from Germany increased from 31% to 70% in the case of infant formulae, from 28% to 55% in the case of follow-on formulae, and from 40% to 100% in the case of special dietetic food. The percentage of weaning food contaminated with B. cereus remained nearly unchanged. It should be stressed, however, that the numbers of B. cereus were almost the same in both studies with the highest count in 1982/83 being 460 and in 1992 600/g. Samples naturally contaminated with counts of about 100 B. cereus/g were reconstituted and incubated at a room temperature of 27 degrees C. Levels of 10(5) B. cereus/g were reached after 7-9 h. Toxigenicity of B. cereus in dried milk products and infant food as well as food poisoning outbreaks attributed to B. cereus are discussed.

Animals↗