Biomedical subjects

J Schmidt

Publications and source records attributed to J Schmidt.

At least 1,081 records · Page 60Linked to original sources

PubMedDate not supplied

Mechanism and impact of organ harvesting and ischemia-reperfusion injury within the graft muscularis in rat small bowel transplantation.

INTRODUCTION: Inflammatory events within the gut muscularis contribute to dysmotility. We hypothesized that manipulation during organ harvesting initiated an inflammatory response via muscularis macrophages and that this cascade was amplified during reperfusion. METHODS: Small bowel transplantation was performed in Lewis rats. To investigate the impact of organ harvesting on muscularis inflammation, cold whole-body perfusion was performed after versus prior to organ harvesting. The role of macrophages was investigated by transplantation of the macrophage-depleted gut. Leukocyte infiltration was investigated in muscularis whole mounts. Mediator mRNA expression was determined by real-time reverse transcriptase polymerase chain reaction. Contractility was assessed in a standard organ bath. RESULTS: Organ harvesting and ischemia-reperfusion induced leukocyte recruitment and mRNA upregulation in the muscularis: interleukin-6 12217-fold, monocyte chemoattractant protein-1 62-fold, ICAM-1 12-fold, cyclooxygenase-2: 8-fold, iNOS: 150-fold. Although organ harvesting with cold ischemia prevented early gene expression, peak expression at 3-hour reperfusion was not changed by modification of the harvesting technique. Compared to controls, transplanted animals showed a 63% decrease in smooth muscle contractility. In contrast, transplanted macrophage-depleted gut exhibited significantly fewer leukocytes and only a 16% decrease in contractility. CONCLUSIONS: Gut manipulation during organ harvesting initiates an inflammatory response within the muscularis that is massively intensified during reperfusion. This change contributes to muscular dysfunction. Furthermore, the results suggested that resident macrophages play a key role in initiating this process.

Animals↗

PubMedDate not supplied

Validity and reliability of the dexter hand evaluation and therapy system in hand-injured patients.

This study compares measurements obtained using the Dexter Hand Evaluation and Therapy System with those obtained using manual goniometers and grip and pinch dynamometers. Intrarater and inter-rater reliabilities for each tool were also examined. Repeated digit range of motion and strength measurements were performed on 30 subjects who had prior upper extremity injuries. Three therapists performed all measurements on each subject three times, using both Dexter and manual instruments. Analyses of variance (ANOVAs) and intraclass correlation coefficients (ICCs) were used to assess concurrent validity and therapist reliability. The findings show that the computerized Dexter finger goniometer and grip and pinch dynamometers provide measurements that are statistically similar to those of their manual counterparts. The ANOVA results for concurrent validity showed no significant differences between mean measurement values across therapists for the Dexter tools compared with the manual tools (p> or =0.54). In addition, no significant differences were found among or between the therapists' measurements. The range of ICCs for intrarater and inter-rater reliability for all four tests was 0.86 to 0.99. However, a two-way ANOVA revealed a therapist effect during pinch strength measurements (p< or =0.05), suggesting the need for same-therapist and same-tool measurements until the Dexter pinch dynamometer has been further evaluated.

Adult↗

PubMedDate not supplied

Characterization and reduction of ischemia/reperfusion injury after experimental pancreas transplantation.

Reperfusion injury after pancreas transplantation is a cause of early graft pancreatitis. The aim of this study was to quantify pancreatic microcirculation after pancreas transplantation in correlation with cold ischemia time. In a second step the effect of N-acetylcysteine on reperfusion damage was tested. Pancreas transplantation was performed in three different groups of male Lewis rats. Groups 1 and 2 received no special treatment. Cold ischemia time was 1.5 hours in group 1 and 16 hours in groups 2 and 3. In group 3 donor and recipient were both treated with N-acetylcysteine (300 mg/kg) 1.5 hours after reperfusion graft microcirculation was quantified by means of intravital microscopy. Rhodamine-labeled leukocytes, fluoroscein isothiocyanate-labeled erythrocytes, and fluoroscein isothiocyanate-albumin were used as fluorochromes. After a cold ischemia time of 16 hours, functional capillary density, erythrocyte velocity, and leukocyte-endothelium interaction were reduced significantly compared to a cold ischemia time of 1.5 hours (P<0.05). After 16 hours of cold ischemia, treatment with N-acetylcysteine improved all of these parameters (P</=0.05). Ischemia/reperfusion injury after experimental pancreas transplantation is characterized by a disturbance of the pancreatic microcirculation exhibiting a correlation with the duration of cold ischemia. Treatment of donor and recipient with N-acetylcysteine resulted in prevention of cold ischemia-induced microcirculatory disturbance.

Animals↗

PubMedDate not supplied

[The effects of hook plates on the subacromial space--a clinical and MRT study].

AIM: The analysis of middle- and long-term results after treatment of acromioclavicular joint injuries with a hook plate as a temporary implant and a comparison of the results with those described in literature have been made. METHOD: In a retrospective study we were able to conduct follow-up examinations on 28 out of 39 Tossy III patients (72 %) who received surgical treatment using a hook plate according to Dreithaler. Examinations took place on average 3.0 (1.2-5.6) years after surgery. A special focus of attention was the effect of the hook plate on the subacromial space. Accordingly, physical examination was supplemented by sonography of the shoulder as well as comparative bilateral shoulder MRI. RESULTS: 86 % of our patients expressed satisfaction with the functional outcome of surgery as opposed to 54 % concerning its cosmetic result. In shoulder sonography no patient turned out to have suffered a higher grade rotator cuff lesion, whereas age-related degenerative alterations were found in 46 % of the patients. Instability under load was found in 7 patients (25 %). Among these were 3 with severe instability (11 %). 2 patients (7 %) were found to have a permanent subluxation of the acromioclavicular joint with partial range of motion impairment. All scores monitored (DASH, Taft, Constant-Murley) on average returned good to excellent results. MRI scans displayed no case of higher grade rotator cuff lesion. In accordance with the findings of ultrasound imaging a higher incidence of extraarticular ossification was found as well as, in some cases, arthrosis of the acromioclavicular joint. CONCLUSION: In our opinion, the hook plate designed by Dreithaler is easy to handle and serves as a qualified implant for temporary stabilisation of the acromioclavicular joint with middle- and long-term good to excellent results.

Acromion↗

PubMedDate not supplied

[The hip head-conserving management of traumatic medial cervical hip fractures with big-fragment screws: a biomechanical examination].

AIM: With the growing number of elderly people in the population and the increasing incidence of proximal hip fractures the question of how to manage the medial hip head fracture is of increasing importance. Especially in Hungary and the Scandinavian countries surgeons prefer hip head-conserving therapy although the redislocation of this fracture and necrosis of the hip head opposes this point of view. METHOD: Encouraged by two theoretical and mathematical calculations, we tested two different possibilities to screw hip head fractures. RESULTS: Our results show that the hip head-conserving therapy with two cranial screws and a three-point-supported screw at Adam's arc has essential biomechanical advantages compared with the situation after conventional osteosynthesis. CONCLUSION: This result encourages us to prefer the minimally invasive head-conserving therapy of medial hip head fractures, especially for treatment of Pauwell's I and II injuries.

Adult↗

PubMedDate not supplied

[Optimization of the dynamic compression in angle-plated osteosynthesis by static interfragmentary compression--experimental results].

Osteosynthesis with an angled plate after intertrochanteric osteotomy is mainly a tension-band-osteosynthesis. Because of the lack of interfragmentary compression at the medial corticalis this technique may lead to pseudarthrosis or delayed bone union. On the basis of theoretical considerations and extensive experiments, we found a distinct improvement in interfragmentary compression when the osteotomy-planes are set at an angle of 6 degrees open to the lateral side before external compression with 1000 N. In this way "functional plate-prebending" is achieved. Thus tension-band-osteosynthesis is completed by compression osteosynthesis.

Bone Plates↗

PubMedDate not supplied

[Subacute sclerosing panencephalitis (SSPE) as differential diagnosis in severe personality changes and ataxia--case report and literature review].

An 8 year old girl presented with progressive change of personality and spastic ataxia since 4 weeks. A year before she had developed focal grand-mal-seizures; at this time laboratory and radiologic findings were normal. The EEG on admission demonstrated marked changes with partially focal, partially generalized hypersynchronic activity, but no SSPE-typical Radermecker-complexes. There were no cells in the cerebrospinal fluid (CSF), a slightly increased level of protein and a normal glucose. Isoelectric focusing showed predominantly measles-specific oligoclonal IgG bands in the CSF. In the magnetic resonance tomography multiple focal white matter lesions in the basal ganglia as well as in cortical and occipitoparietal regions could be seen. At the age of two the girl had suffered from measles, the child didn't receive any vaccination. The combination of history, CSF-, MRI-results and EEG lead to the diagnosis of subacute sclerosing panencephalitis (SSPE). After 3 months the clinical and radiological abnormalities had markedly increased. On the background of this history SSPE should be considered as differential diagnosis in patients with changes of personality.

Cerebrospinal Fluid Proteins↗

PubMedDate not supplied

[Modified intracorporeal lithotripsy for cement removal in hip prosthesis exchange operations--experimental principles].

INTRODUCTION: Particularly problematic in total hip revision arthroplasty is the cement removal out of the depth of the femoral canal; it is also costly in time and effort. The extracorporal shock wave lithotripsy proved to be an unsuitable method. With the present paper we proved experimentally a newly developed endoscopically controlled modified intracorporal lithotripter (Swiss Orthoclast) for the removal of bone cement. METHODS: We tested the efficiency on standardized cement specimens of different manufacturers in vitro. We compared both conventional removing techniques with mallet and chisel and a pneumatically powered chisel with formalin fixed human femora. During these experiments we measured the intrafemoral pressure distally to the cement layer. RESULTS: We achieved a high energy (max. 450 mJ) and a very effective fragmentation of the cement (40 mg fragments calculated on the single impulse of 350 mJ). The endoscopic control ensures a safe control of the cement removal even in the depth of the femoral canal. No bone damage occurred macroscopically and radiologically. No heat or toxic products developed. Using the Swiss Orthoclast the intrafemoral pressure was the lowest possible (7 mbar). Even with hammer and chisel or the pneumatically powered chisel the pressure was too low (max. 55 mbar with mallet and chisel) to cause a fat embolic syndrome. CONCLUSION: As a result of these experiments we started with clinical trials (with permission of the Ethic commission) to evaluate the practicability of the modified intracorporal lithotripter (Swiss Orthoclast) for cement removal.

Arthroscopes↗

PubMedDate not supplied

Sustained reduction of exercise perfusion defect extent and severity with isosorbide mononitrate (Imdur) as demonstrated by means of technetium 99m sestamibi.

BACKGROUND: The impact of long-acting nitrates on the extent and severity of stress-induced myocardial ischemia is not well described, especially after long-term treatment. METHODS: Forty patients with chronic stable angina and reversible ischemia on an exercise stress myocardial perfusion single photon emission computed tomography (ex-SPECT) were prospectively studied in a 6-week period. At baseline, rest thallium-201/exercise stress technetium 99m sestamibi SPECT was performed, followed by treatment with extended-release isosorbide 5-mononitrate (5-ISMN, Imdur). Follow-up ex-SPECT was performed 5 days and 6 weeks after the initiation of therapy with extended-release 5-ISMN. The exercise treadmill testing (ETT) protocol and exercise duration of the follow-up studies were the same as that of the baseline ETT. Defect extent and severity were analyzed both by means of an automated quantitative method, with CEqual software, and visually, with a 20-segment scoring system (which was also used to derive a summed stress score [SSS]). RESULTS: In the 6-week study period, significant reductions occurred in both the extent and the severity of exercise-induced ischemia by means of quantitative SPECT (13.8% [P<.0003] and 12.7% [P<.0003], respectively). There was no significant change in these variables between stages 2 (day 5) and 3 (6 weeks), indicating no development of tolerance to the nitrate effect. Similar reductions were noted by means of the visual analysis (SSS reduction of 13.0% [P<.002]) in the entire study period. CONCLUSIONS: Patients with chronic-stable-angina treated with a long-acting nitrate demonstrate improvement in myocardial perfusion defect extent and severity in an extended period by means of both visual and quantitative analysis of sequential exercise testing to the same rate-pressure product end point.

Aged↗

PubMedDate not supplied

[The effect of DL-methionine, N-hydroxymethyl-DL-methionine calcium salt (Mepron) and DL-methionine hydroxy analog calcium salt (MHA) on the N-deposits of calves].

Digestibility and N balance experiments with calves showed that the methionine requirement of the host animal is covered by microbial protein synthesis even in the already ruminant animal. A supplement of the ration with DL methionine is only effective when it is provided in milk replacer. The MHA substitution of the ration has only little influence on N retention, independent of its supply in milk replacer or concentrated feed. MEPRON proved to be the most effective methionine derivative. As supplement both with the fluid feed and with the concentrated feed this compound shows exclusively positive results even in already ruminant calves with regard to live weight gain, N retention and the content of free methionine in the blood serum of the test animals.

Animal Feed↗

PubMedDate not supplied

Planning home care services for people living with AIDS.

As the number of individuals infected with the human immunodeficiency virus (HIV) increases, so does the demand for healthcare services. The debilitating manifestations seen in the later stages of illness, in association with the diagnosis of acquired immune deficiency syndrome (AIDS), often require the assistance of home care providers. Establishing a database of information, not only on the clinical needs of individuals but also on person-specific details, is essential to identify the nursing care needs of this population. The delivery of home care services to people living with AIDS (PLWA) includes the client, the significant other(s), and the community in which the client resides.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Prophylactic dynamic screw fixation of the asymptomatic hip in slipped capital femoral epiphysis.

Prophylactic dynamic screw fixation (DSF) of clinically and radiographically unaffected hips of 34 patients with a contralateral slipped capital femoral epiphysis and no evidence of an endocrinopathy or systemic disorder was performed using a single cannulated screw. Follow-up ranged from 2 to 12 years (average, 5.4 years). There was no case of perioperative complication and no avascular necrosis or chondrolysis occurred. No preslip or slip became apparent. In all 34 hips, no tendency toward premature closure of the epiphysis could be observed, no growth disturbance including greater trochanteric overgrowth, coxa brevis, or coxa vara was noted. This study supports the prophylactic treatment of the asymptomatic hip, using a simple and safe fixation method.

Adolescent↗

PubMedDate not supplied

Attachment of Trypanosoma cruzi epimastigotes to hydrophobic substrates and use of this property to separate stages and promote metacyclogenesis.

In vivo, epimastigotes of Trypanosoma cruzi colonize a lipidic superficial layer of the rectal cuticle of the vector Triatoma infestans. In vitro, epimastigotes of four cultured strains and one strain from reduviids use a terminal area of the flagellum to attach to a variety of artificial hydrophobic substances, such as hydrocarbons and a range of synthetic plastics. Trypomastigotes did not attach to these substrates. Hydrophilic molecules, such as neutral or negatively charged polysaccharides, did not facilitate binding. Epimastigotes and trypomastigotes were artificially bound by electrostatic forces to positively charged chitosan or DEAE-Sephacel over their entire surface. Tween 20 and lipid-binding serum albumin effectively inhibited the hydrophobic attachment. Based on this hydrophobic interaction of epimastigotes, a new chromatography technique has been devised to gently separate trypomastigotes from epimastigotes using octacosane-coated beads. Furthermore, the in vitro transformation of epimastigotes to trypomastigotes was enhanced if epimastigotes were permitted to attach to hydrophobic, wax-coated culture vessels.

Ammonium Chloride↗

PubMedDate not supplied

Using a teaching guide for better postpartum and infant care.

The development and use of a guide for postpartum and infant care teaching is discussed, including the rationale, methods,and advantages of using this tool at two hospitals of different sizes. Also discussed are the preparation of personnel, ongoing development, and extended uses of the guide.

Family↗

PubMedDate not supplied

Peripartum cardiomyopathy.

Peripartum cardiomyopathy is a rare and devastating disease of unknown etiology that manifests between the last trimester of pregnancy and five postpartum months. This disease often is confused with many other illnesses, and even with hemodynamic changes in normal pregnancy. Pathophysiology, signs, and symptoms of this unique cardiomyopathy are presented and case studies offered. Since outcome of this disease is directly related to duration of the illness, nurses must be aware of the symptoms and investigate them immediately. The nurse must support the patient and involve the family and social services in the patient's recovery.

Cardiomyopathy, Dilated↗

PubMedDate not supplied

Influence of anisotropy on local and global measures of potential gradient in computer models of defibrillation.

A heart-torso model including fiber orientation is used to calculate electric field strength in an active-can transvenous defibrillation system and estimate errors due to inadequate description of the anisotropy of the myocardium. Using a minimum potential gradient (5 V/cm) in a critical mass (95%) of the tissue, the estimated defibrillation voltage threshold for a right ventricular transvenous lead placement differs by only 4.5% when using isotropic myocardial conductivity compared to a model with realistic fiber architecture. In addition, pointwise comparisons of the two solutions reveal differences of 10.8% rms in potential gradient strength and 31.6% rms in current density magnitude in the myocardium, resulting in a change in the location of the low gradient regions. These results suggest that if a minimum potential gradient throughout the heart is necessary to avoid reinitiation of fibrillatory wave fronts, then isotropic models are adequate for modeling the electric field in the heart. Alternatively, the model demonstrates the use of physiologically based descriptions of anisotropy and fiber orientation, which will soon allow simulations of shock induced membrane polarization during defibrillation.

Adult↗

PubMedDate not supplied

Metabolic transformation of the brassinosteroid 24-epi-castasterone by the cockroach Periplaneta americana.

After feeding of 24-epi-castasterone to the cockroach Periplaneta americana an organ-specific epimerization of the brassinosteroid to 2,24-diepi-castasterone could be detected in female insects. The metabolite being observed only in the ovaries and not in the testes of the insect was identified by GC/MS in comparison with a synthesized authentic sample. Contrary, 24-epi-brassinolide is not metabolized in the sexual organs of Periplaneta americana. This is the first evidence of a metabolic transformation of a brassinosteroid in insects.

Animals↗

PubMedDate not supplied

Laparoscopic partial pericystectomy of Echinococcus granulosus cysts in the liver.

Laparoscopic partial pericystectomy is a promising new therapeutical approach in surgery of hydatid liver disease. In combination with a review of the published results of laparoscopic therapy for hydatid disease the actual relevance of this technique should be defined. Together with our own experience with this technique we evaluated all patients with hydatid liver disease from Echinococcus granulosus published in literature operated either by pericystectomy or by partial pericystectomy. The review was projected as a search over DIMDI data access. This technique is practicable without increasing the risk of intraabdominal spillage of scolices if well-known security criteria are respected. Additional training is not necessary. Laparoscopic treatment of Echinococcus multilocularis is not possible yet, as complicated liver resections may be required for these patients. Hydatid hepatic cysts of E. granulosus however may be operated upon laparoscopically and do not necessarily require open surgery. While working under visual control minimal invasiveness is achievable and post-operative hospital stay can be reduced. This new technique is a feasible method, especially regarding obese patients, but on the other hand it is limited by a laparoscopically inaccessible intrahepatic localization (Segments IVa, VII, VIII and small centrally located cysts).

Echinococcosis, Hepatic↗