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Biomedical subjects

R Lange

Publications and source records attributed to R Lange.

At least 235 records · Page 13Linked to original sources

The violence management team. An approach to aggressive behaviour in a general hospital.

OBJECTIVES: To describe the establishment of a violence management team (VMT) to manage patients who exhibit violent behaviour in a general hospital (Flinders Medical Centre), and to review data collected in the first 44 months of operation. METHODS: The VMT consisted of a doctor, a senior nurse and four orderlies. Calls to the team were recorded and audited. Data were collected from patient case notes and supplemented, where necessary, with information from medical and nursing staff. RESULTS: There were 282 calls for the VMT during the study period, most often to patients with organic mental disorders (45%), substance abuse disorders (18%) and personality disorders (15%). In 30% of calls, verbal placation alone was sufficient to manage the patient; however, 62% of patients needed physical restraint (i.e., were physically held by team members) and 53% were administered a sedative medication. CONCLUSIONS: Violent behaviour in patients in a general hospital is an important problem, often caused by organic mental disorders. This, and the need to restrain aggressive patients so that they can receive essential medical care, suggest that such behaviour should be treated as a clinical problem rather than one for security guards or the police. The VMT provides a mechanism for dealing with aggressive patients which ensures good patient management, as well as protecting the health and safety of staff. It is also a monitor for quality assurance purposes, and provides data to determine the causes of patient violence and to implement prevention programs.

Diagnosis-Related Groups↗

The cellular concentration of the sigma S subunit of RNA polymerase in Escherichia coli is controlled at the levels of transcription, translation, and protein stability.

The second vegetative sigma factor sigma S (encoded by the rpoS gene) is the master regulator in a complex regulatory network that governs the expression of many stationary phase-induced and osmotically regulated genes in Escherichia coli. Using a combination of gene-fusion technology and quantitative immunoblot, pulse-labeling, and immunoprecipitation analyses, we demonstrate here that rpoS/sigma S expression is not only transcriptionally controlled, but is also extensively regulated at the levels of translation and protein stability. rpoS transcription is inversely correlated with growth rate and is negatively controlled by cAMP-CRP. In complex medium rpoS transcription is stimulated during entry into stationary phase, whereas in minimal media, it is not significantly induced. rpoS translation is stimulated during transition into stationary phase as well as by an increase in medium osmolarity. A model involving mRNA secondary structure is suggested for this novel type of post-transcriptional growth phase-dependent and osmotic regulation. Furthermore, sigma S is a highly unstable protein in exponentially growing cells (with a half-life of 1.4 min), that is stabilized at the onset of starvation. When cells are grown in minimal glucose medium, translational induction and sigma S stabilization occur in a temporal order with the former being stimulated already in late exponential phase and the latter taking place at the onset of starvation. Although sigma S does not control its own transcription, it is apparently indirectly involved in a negative feedback control that operates on the post-transcriptional level. Our analysis also indicates that at least five different signals [cAMP, a growth rate-related signal (ppGpp?), a cell density signal, an osmotic signal, and a starvation signal] are involved in the control of all these processes that regulate rpoS/sigma S expression.

Base Sequence↗

Inactivation of the N-CAM gene in mice results in size reduction of the olfactory bulb and deficits in spatial learning.

Neural-cell adhesion molecules (N-CAMs) are members of the immunoglobulin superfamily mediating homo- and heterophilic cell-cell interactions. N-CAM exists in various isoforms which are generated by alternative splicing. During embryonic development, N-CAMs are expressed in derivatives of all three germ layers, whereas in the adult animal they are predominantly present in neural tissue. Processes like neurulation, axonal outgrowth, histogenesis of the retina and development of the olfactory system are correlated with the regulated expression of N-CAMs. We show here that N-CAM-deficient mice generated by gene targeting appear healthy and fertile, but adult mutants show a 10% reduction in overall brain weight and a 36% decline in size of the olfactory bulb. N-CAM deficiency coincides with almost total loss of protein-bound alpha-(2,8)-linked polysialic acid, a carbohydrate structure thought to be correlated with neural development and plasticity. The animals showed deficits in spatial learning when tested in the Morris water maze, whereas activity and motor abilities appeared normal.

Animals↗

Overexpression of a cytochrome P-450 of the 2a family (Cyp2a-5) in chemically induced hepatomas from female mice.

Chemical hepatocarcinogenesis in female mice, induced by 5,9-dimethyl(7H)dibenzo[c,g]carbazole, leads to the overexpression of a cytochrome P-450 of the 2a family. This protein was identified as Cyp2a-5, by the use of immunoblots obtained from isoelectric focusing gels. This method allowed the distinction of Cyp2a-5 from Cyp2a-4, another mouse liver cytochrome P-450, by taking advantage of their slightly different pI values. The theoretical pI values, determined from the amino acid sequence, were pI 9.91 for Cyp2a-4 and pI 10.01 for Cyp2a-5. Other structurally related forms were not detected. In hepatomas from female mice, only the Cyp2a-5 form was overexpressed (2-3 fold). Male mice showed a weak expression of Cyp2a-4 and Cyp2a-5 in control liver samples and in hepatomas. The expression of both forms was increased more than fivefold upon castration. Pyrazole induces specifically the Cyp2a-5 form. The Cyp2a-5 overexpression was correlated with enhanced microsomal coumarin-7-hydroxylase and testosterone-15 alpha-hydroxylase activities. An immunohistochemical study showed that Cyp2a-4 and Cyp2a-5 are expressed uniformly in female livers, but centrilobularly in male livers. In hepatomas, this localisation is perturbed; in females we observed a focal cell localisation, and the Cyp2a-containing cells were often hypertrophic and polyploid. In hepatomas from male mice, the Cyp2a-containing cells became dispersed. From a comparison with other studies, the Cyp2a-5 overexpression appears to be a general feature of hepatocarcinogenesis in mice.

Animals↗

Nonparenchymal cell and hepatocellular injury to human liver grafts assessed by enzyme-release into the perfusate.

Experimental studies have demonstrated preferential injury to the sinusoidal endothelium during liver preservation with University of Wisconsin (UW) or Euro-Collins solution. This endothelial cell injury has an unclear pathogenesis, and it has not yet been studied in the human liver. Therefore, we analyzed the effluent of 21 human liver allografts after cold storage. Markers of hepatocellular and nonparenchymal cell injury were assessed. After preservation with UW solution, early effluent samples contained 1823 +/- 1494 U/l lactate dehydrogenase (LDH), 493 +/- 516 U/l alanine aminotransferase (ALT) and 132 +/- 97 U/l creatine kinase (CK; 92 +/- 92 U/l CK-BB). The effluent of livers preserved in histidine-tryptophan-ketoglutarate (HTK) solution contained 3681 +/- 2009 U/l LDH, 1139 +/- 599 U/l ALT and 282 +/- 120 U/l CK (165 +/- 91 U/l CK-BB). Comparison of effluent enzyme activities with liver tissue enzyme activities indicates that the release of the endothelial cell/nonparenchymal cell marker creatine kinase was higher, by a factor of 7-8, than the release of hepatocellular enzymes. Effluent thrombomodulin concentrations were 123 +/- 248 ng/ml (UW) and 604 +/- 299 ng/ml (HTK), and effluent glucose concentrations, 40.3 +/- 27.0 mM (726 +/- 486 mg/dl; UW) and 10.4 +/- 4.5 mM (187 +/- 81 mg/dl; HTK). We conclude that prominent endothelial cell injury also occurs in human liver grafts after preservation with UW solution or HTK solution. This endothelial cell injury is unlikely to be caused by hypoxia-induced energy deficiency, as it affects a cell type with a high glycolytic capacity in the presence of high glucose levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

[The value of duplex sonography after orthotopic liver transplantation. Experience with 44 patients].

In a prospective study, 44 patients (11 women, 33 men) who had received orthotopic liver transplants underwent a total of 196 consecutive duplex Doppler ultrasound examinations. The aim of the study was to evaluate the correlation between the pulsatile flow index (PFI) and the damping index (DI) as far as complications as rejection or cholangitis were concerned. The patients were examined five times each on average. The PFI and DI were measured in the hepatic artery, the portal vein and the hepatic veins. The findings were compared with the clinical course (cholangitis, rejection) and the histomorphological diagnosis as determined in biopsy specimens. In biopsy-proven rejection episodes, the sensitivity of the PFI in the hepatic artery was 69.4%, the specificity 72.2%. The sensitivity of the DI in the hepatic vein was 89.4%, the specificity 89.1%. Combining the two, specificity was more than 90%. PFI and DI in the portal vein bore no apparent relation to clinical course or histomorphological diagnosis. We found duplex Doppler ultrasound extremely beneficial in determining the timing and indication for liver biopsy. In addition, this simple examination, which can be performed as often as desired, accurately shows the transplanted liver's response to measures taken to counter rejection.

Adult↗

Comparison of histidine-tryptophan-ketoglutarate (HTK) solution versus University of Wisconsin (UW) solution for organ preservation in human liver transplantation. A prospective, randomized study.

Over a 30-month period, 60 patients (30 in each group) suffering from end-stage liver disease or primary hepatic malignancy and scheduled for liver transplantation were enrolled in a prospective, randomized study to compare two methods of liver preservation: histidine-tryptophan-ketoglutarate (HTK) solution versus University of Wisconsin (UW) solution. Entry criteria for both groups were: age (18-65 years), elective surgery (transplantable or urgent category of the recipients), first transplantations and harvesting procedure performed by the same team. The parameters under investigation were the clinical and laboratory data pre- and post-transplantation, as well as follow-up data such as complications and survival. There were no significant differences in the two groups as far as the evaluation criteria were concerned, even when cold ischemia time was more than 15 h (n = 7). A slight, yet not significant, increase in late complications of the biliary anastomoses could be seen in the UW group. Hepatocellular injury (SGOT, SGPT, GLDH, lactate) appeared to be more marked in the HTK group. These results suggest that both HTK and UW solutions are appropriate for clinical use in liver transplantation, even if cold ischemia time is more than 15 h.

Adenosine↗

Activation volume and energetic properties of the binding of CO to hemoproteins.

We have investigated the CO binding to various reduced hemoproteins by stopped-flow rapid mixing as a function of pressure (from 0.1 to 200 MPa) and temperature (from 4 to 35 degrees C). In particular, we studied several varieties of cytochrome P-450: CYP11A1 (scc), CYP2B4 (LM2), CYP3A6 (LM3c), and Cyp2a (7 alpha), as well as chloroperoxidase and lactoperoxidase, and compared the results to data reported for other hemoproteins. Whereas the CO binding activation enthalpy delta H++ and entropy delta S++ (correlated through a compensation effect) varied greatly between the hemoproteins, with no apparent relation to structural features, the pressure effect depended on the nature of the proximal axial heme ligand: the activation volume was very small for cysteine (S-) ligand hemoproteins (delta V++ = +1 to +6 ml mol-1), and markedly negative for histidine (N) ligand hemoproteins (delta V++ = -3 to -36 ml mol-1). Furthermore, the transition state volume of the histidine ligand class enzymes, but not that of the cysteine ligand enzymes, depended on the solvent composition. These results suggest that the CO-binding transition state of the S-ligand class has a molecular conformation similar to the ground state. In the histidine class, however, the transition state appears to involve protein conformational changes and/or solvation processes.

Adrenal Cortex↗

Characterization of antisera raised against Treponema denticola (ATCC 33521) whole cell, outer sheath, protoplasmic cylinder, and axial flagella.

In this study we produced polyclonal antisera directed to whole cell, outer sheath, protoplasmic cylinder and axial flagella sonicates of Treponema denticola (ATCC 33521) reference strain. Furthermore, the reactivity of the antisera was determined, using the enzyme-linked immunosorbent assay and immunoblotting techniques. As control antigen, other gram-negative bacteria (Salmonella minnesota, Escherichia coli) and related pathogenic spirochetes (Borrelia burgdorferi and Treponema pallidum) were used. It could be shown that the purified antibodies were specific for Treponema denticola and did not cross-react with the control antigens tested. Interestingly, with one exception, the anti-axial flagella antibody reacted with the flagellin of Treponema pallidum but not with Borrelia burgdorferi flagella. It is intended to use these antisera for the characterization of patient isolates in further studies.

Antibodies, Bacterial↗

Production and characterization of a polyclonal antiserum against Spiroplasma mirum (ATCC 29335).

Spiroplasma mirum (ATCC 29335), an American tick isolate, was cultivated and its purity was controlled using electron microscopy and Tricine-SDS-PAGE. In the SDS-PAGE analysis, the protein pattern of the antigen used revealed a polypeptide profile (35 bands) with an approximate molecular weight of 161 kDa to 10.5 kDa. This strain was used to immunize two rabbits. The produced antisera did not cross-react with Mycoplasma pneumoniae, Salmonella minnesota, Borrelia burgdorferi, Treponema pallidum but did still react in Western blot analysis with Spiroplasma mirum at a dilution of 1:128.000. This specific and sensitive antiserum was used to examine 72 midgut smears of Berlin ticks (lxodes ricinus) individually by direct immunofluorescence. In 26 samples, we could demonstrate fluorescent structures, but we were not able to culture spiroplasmas from these samples.

Animals↗

A new method of veno-venous bypass during human orthotopic liver transplantation.

Veno-venous bypass is commonly used during orthotopic liver transplantation, but there is some controversy as to whether it contributes to a better outcome. Low shunt flows frequently reduce the efficacy of portofemoro-axillary systems and so a percutaneous cannulation technique for the subclavian and femoral vein with large bore catheters was developed in order to facilitate bypass management. This study reports the performance and complications of a portofemoro-subclavian bypass system during the anhepatic phase of human orthotopic liver transplantation in 85 patients. A percutaneous cannulation technique and two 7 mm (subclavian and femoral) catheters, inserted pre-operatively, were used in a pump driven portofemoro-subclavian bypass system. Coagulation profiles, shunt flows, haemodynamic parameters, and peri-operative complications associated with bypass were recorded for each patient. Percutaneous cannulation of the left femoral and subclavian vein was successful in 78 patients (91.8%). Mean femoro-subclavian shunt flow was 1.45 l.min-1 (SD 0.37), and mean portofemoro-subclavian flow was 4.28 l.min-1 (SD 1.03). Although oxygen delivery was not maintained at pre-shunt levels (559.7 (SD 147) vs 506 (SD 107) ml.min-1.m-2, p < 0.05) renal perfusion pressure stayed above 50 mmHg (during shunt it was 56 (SD 9) mmHg). One intra-operative air embolism was observed (1.2%), and in one patient a myocardial infarction occurred during the anhepatic phase; neither complication was considered to be related to the percutaneous cannulation technique. There were no bleeding complications. After operation, all chest X rays were normal and clinical examination revealed no adverse effects of portofemoro-subclavian bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The nlpD gene is located in an operon with rpoS on the Escherichia coli chromosome and encodes a novel lipoprotein with a potential function in cell wall formation.

rpoS is the structural gene for sigma s, which is a second vegetative sigma subunit of RNA polymerase in Escherichia coli and is involved in the expression of many stationary phase-induced genes. Upstream of rpoS is an open reading frame (ORF) whose function and regulation have not been studied. Strong overproduction of its gene product using the IPTG-inducible tac promoter leads to the formation of bulges at the cell septum and the cell poles, and in rapidly growing cells brings about cell lysis, indicating that the gene product has a hydrolytic function in cell wall formation or maintenance. This is corroborated by sequence homology to lysostaphin, a cell wall lytic exoenzyme synthesized by two Staphylococcus strains. Using globomycin, a specific inhibitor of signal peptidase II, we demonstrate that the product of the ORF is a novel lipoprotein (NlpD). Two transcriptional start sites for nlpD have been localized. In contrast to rpoS, nlpD is not induced during entry into stationary phase. Growth-phase-regulated transcription of rpoS is initiated at additional sites within the nlpD ORF, but the nlpD promoters contribute substantially to the basal level of rpoS expression in exponentially growing cells, indicating that nlpD and rpoS form an operon.

Amino Acid Sequence↗

Acute efficacy and chronic follow-up of patients with non-thoracotomy third generation implantable defibrillators.

Non-thoracotomy implantation of implantable cardioverter defibrillators (ICDs) has simplified the process of device insertion, promising to decrease associated procedural complications while providing sudden death protection at least equal to epicardial systems. This study presents the acute and chronic results of 110 patients who underwent attempted non-thoracotomy ICD implantation with the Medtronic Transvene lead system and PCD model 7217 or 7219. Of the 110 patients attempted, 100 (91%) had the system successfully implanted without the need for an epicardial patch. One patient died 1 week postoperatively of septic shock related to the implantation (0.9% perioperative mortality). During follow-up of 16 +/- 11 months, 45% of the patients had an event detected as ventricular tachycardia; 26% of these detections were felt clinically to be due to supraventricular rhythms. Of the remainder, 87% were successfully treated with the first VT therapy, and 98% were terminated by the final therapy; 66% of the patients had at least one episode of ventricular fibrillation, of which 5% were felt to be inappropriate detections; 85% of the appropriate episodes were successfully treated with the first VF therapy, and all were converted by the final therapy. Total mortality at 6, 12, and 24 months was 3%, 11%, and 19% respectively. Only one patient had sudden cardiac death, occurring at 13 months postimplant. Overall, the non-thoracotomy lead system for this ICD displayed infrequent implant complications and proved to be reliable at terminating arrhythmias and maintaining a low rate of sudden cardiac death in this high risk population.

Adult↗

Female pelvis: impact of MR imaging on treatment decisions and net cost analysis.

PURPOSE: To determine the impact of gynecologic magnetic resonance (MR) imaging on treatment decisions and net cost. MATERIALS AND METHODS: Sixty-nine consecutive women were referred for 70 pelvic MR imaging examinations. Diagnosis and treatment plans were obtained from referring physicians before and immediately after they were given verbal reports of MR imaging results. Outcome regarding treatment and symptoms was obtained at a mean follow-up of 10.9 months. RESULTS: Of 49 (71%) patients originally recommended for surgery, 36 (73%) either did not undergo surgery or less invasive surgery was performed. In 58 (84%) patients, the treatment performed was that recommended after performance of MR imaging. Symptoms resolved in 57 (83%) patients. Use of MR imaging resulted in an overall savings of $63 per patient ($1,736 per patient originally recommended for surgery). CONCLUSION: Use of pelvic MR imaging in diagnosis of some gynecologic diseases may alter treatment, decrease the number of invasive surgical procedures performed, and reduce total health care expenditures.

Adolescent↗

[Role of transesophageal echocardiography in tricuspid valve repair].

This paper reviews the role of echocardiography in tricuspid valve repair by analyzing the results of three clinical studies. The first investigation was performed for assessing the outcome of two surgical techniques in two groups of patients who underwent De Vega's suture annuloplasty or Carpentier ring implantation. The patients were studied by color Doppler echocardiography after a mean follow-up of 28.7 +/- 11.1 months. The results showed lower degree of tricuspid valve regurgitation in the group of patients who underwent De Vega annuloplasty. The second study demonstrates a new application of transesophageal echocardiography (TEE) for optimizing tricuspid valve annuloplasty. Twenty-three patients with moderate to severe tricuspid regurgitation underwent De Vega's annuloplasty. After cardiopulmonary bypass the tension on the suture was adjusted until the surgeon could not feel any regurgitant jet by the intraatrial palpation; subsequently, the tension was further adjusted under guidance of TEE. The data obtained by the traditional palpation were compared with the data obtained by TEE. A significant reduction of residual tricuspid regurgitation was obtained by TEE when compared to the data obtained by intraatrial palpation. The results showed that the use of TEE was able to optimize the De Vega's annuloplasty by reducing residual tricuspid regurgitation. The third study investigated tricuspid valve regurgitation commonly observed after orthotopic cardiac transplantation (HTX). Aim of the study was to assess the degree of regurgitation and its etiology. Twenty-five patients undergoing HTX were studied intraoperatively by TEE. The results showed that tricuspid regurgitation occurs in most patients immediately after HTX; it is correlated to the ratio recipient-donor right atrium; surgical techniques which reduce the recipient atrium may decrease the occurrence and the degree of tricuspid regurgitation. The above mentioned clinical investigations showed a many-sided role of TEE in tricuspid valve repair. It provides not only a useful diagnostic tool for evaluating residual regurgitation, but it may actively guide the surgical procedures and contribute to improve the surgical technique.

Adult↗

[The effect of thioglycoside-containing feed on the growth, thyroid hormone and thiocyanate status of swine and poultry].

Feed containing rapeseed meal (RSM) with high glucosinolate content (10 mmol/kg feed) induced a strong increase of thyroid weight in pigs and poultry. Supplementary iodine reduced the antithyroid effect, but, it could not cancel it. Only at a low glucosinolate content (0.7 mmol/kg feed) a normal weight of thyroid was established. As the iodine supplementation increased the serum T4 value increased. The thiocyanate serum level increased irrespective of glucosinolate content of the feed. The urine level was significantly decreased due to lower dietary glucosinolate level. Obviously, the goitrogenic effect of the RSM does not correlate with the increased thiocyanate serum level.

Animal Feed↗

[Liver complications of HELLP syndrome--an indication for emergency liver transplantation?].

Three patients were treated suffering from a severe HELLP-syndrome. The problems as far as the diagnostic and therapy are concerned are discussed. All three patients had to be operated on in an emergency state. The operations were performed due to acute and severe abdominal bleeding. Two of the patients needed liver transplantation as an emergency procedure, one of them died after hepatectomy waiting for a graft. Another one died seven weeks after successful transplantation due to prolonged sepsis. The third patient is more than one year after transplantation alive and doing well.

Adult↗

[Atrioventricular valve insufficiency and atrial geometry in orthotopic heart transplantation].

Tricuspid and mitral valve regurgitation are commonly observed in patients after orthotopic cardiac transplantation (HTX). The etiology is still controversial. Aim of the present study was to assess the degree of regurgitation and its etiology. Twenty-five patients (mean age 47.9 +/- 11.8 years) undergoing HTX were studied intraoperatively by transesophageal echocardiography. The degree of tricuspid and mitral valve regurgitation was assessed by planimetry of maximum systolic area of the regurgitant jet (JA). The cross-sectional area of right and left atrium and the recipient (R) and the donor (D) cross-sectional area of the atria, and their ratio (R/D) were assessed by two-dimensional echocardiography. The following preoperative and perioperative hemodynamic parameters were measured: systemic arterial pressure, cardiac index, pulmonary artery pressure, and pulmonary vascular resistance. Tricuspid regurgitation was found in 21/25 (84%) patients, mitral regurgitation in 12/25 (48%). The degree of mitral regurgitation showed no correlation to any of the studied parameters. Tricuspid regurgitation showed no correlation to the hemodynamic parameters, but showed significant correlation to R/D ratio (JA versus R/D: r = 0.90; SEE = 0.2) and to the dimensions of the recipient atrium (JA versus R: r = 0.89; SEE = 1.9). Three patients who underwent bicaval anastomoses did not show tricuspid regurgitation. In conclusion, tricuspid regurgitation has a higher prevalence than mitral regurgitation and occurs in most patients immediately after HTX; mitral regurgitation was less frequent than tricuspid regurgitation and was not correlated to the hemodynamic parameters or to the distortion of atrial geometry; tricuspid regurgitation was significantly correlated to the ratio of recipient/donor right atrium; surgical techniques reducing the recipient atrium may decrease the occurrence and the degree of tricuspid regurgitation.

Adult↗