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Biomedical subjects

J Heuer

Publications and source records attributed to J Heuer.

At least 19 recordsLinked to original sources
PubMed2006

[LMA CTrach: initial experiences in patients with difficult-to-manage airways].

BACKGROUND: The Intubating LMA was designed to facilitate blind intubation and to provide ventilation between two intubation attempts. However, blind intubation can be associated with a risk of oesophageal penetration, therefore, a flexible bronchoscope is frequently used to assist tracheal intubation. This leads to increased burdens on materials and personal resources and prolongs intubation times. Hence the LMA CTrach laryngeal mask airway (CTrach) was developed with an integrated fibreoptic system which can be connected to a monitor for visualisation of the larynx during intubation. METHODS: We detail the initial experience gained with the practical handling of the CTrach and the application in 10 patients with difficult-to-manage airways. Laryngeal views were graduated in a CTrach-specific classification from grade I (clear view of the arytenoids, glottis and epiglottis) to grade IV (no part of the larynx can be identified). Adjusting manoeuvres were defined to improve the view of laryngeal structures. RESULTS: All patients could be successfully ventilated with the CTrach. Ventilation quality was rated adequate in nine and possible in one patient. The initial distribution of the laryngeal view between grades I-IV was 1/2/1/6 and after adjusting manoeuvres to improve the laryngeal view the grade distribution was 3/5/0/2. Intubation through the CTrach was successful in all patients, nine at first and one at the second attempt. CONCLUSION: In this small sample of patients with difficult-to-manage airways, the CTrach yielded high success rates for both ventilation and tracheal intubation. Adjusting manoeuvres can improve the laryngeal view further.

Anesthesia, Inhalation↗
PubMed2005

[The applicability of the ProSeal laryngeal mask airway for laparotomies].

OBJECTIVE: The ProSeal laryngeal mask airway (PLMA) has some design features, which in contrast to the classic LMA allow separation of the respiration from the gastrointestinal canal, a higher leak pressure and a better position assessment. It can be debated if these instrumental improvements justify the application of the PLMA for elective abdominal surgery in cases without aspiration risk. Insertion of airway instruments and gastric tube with regard to insertion time and difficulties and frequency of side effects were to be compared for the tracheal tube and the PLMA. The pharyngolaryngeal morbidity for both methods was also of interest. It was approached with direct and indirect postoperative interview techniques. METHODS: 65 patients were investigated both at the university hospital and at the hospital Neu-Bethlehem in Goettingen. The surgical intervention was a surgical or gynecological laparotomy. Anaesthesia was performed with a standardized application of propofol, alfentanil and rocuronium. Glycopyrroniumbromide was applied to minimize salivation. A total of 34 patients received the PLMA, 31 were intubated. All of them were provided with a gastric tube. RESULTS: The insertion of the PLMA took 70 seconds (21 - 234) on average, the intubation 57 seconds (35 - 145). Endotracheal intubation was accomplished in a shorter time period, but there was no significant difference in comparison with the PLMA-group (p = 0.1924). Insertion of the PLMA was significantly more difficult than oral intubation (p = 0.0006). The base of the tongue and the dorsal pharyngeal wall, but not the vocal cords or the epiglottis were visible in those cases, where the PLMA could not be positioned at all. Here the tip of the cuff was bended. The time period for positioning of the gastric tube was 38 seconds (15 - 75) in the PLMA- and 57 seconds (22 - 219) in the tracheal tube group. With these results the gastric tube positioning was accomplished in a significantly shorter time period in the PLMA-group (p = 0.0267), but not at a significantly higher level of difficulty for endotracheal intubation (p = 0,6247). In one case there was regurgitation through the drainage tube without aspiration before gastric tube placement. At the direct interview 16 patients in the PLMA-group and 23 of the tube group mentioned postoperative throat symptoms. The most frequent symptom was hoarseness (11 PLMA- and 18 intubated patients). There was no significant difference between PLMA- and tracheal tube application with regard to the total number of patients with pharyngolaryngeal morbidity and the frequency of single symptoms. The same is true for the degree of the symptoms. There was a tendency for a longer prevalence of throat symptoms after intubation, but no significant difference. CONCLUSION: In this investigation the PLMA could be successfully applied for elective laparotomies in cases without the risk of aspiration. Proper patient selection and a deep level of anaesthesia are important. The advantage for patients receiving the PLMA is a smooth recovery without cough, but not so much a reduced amount of pharyngolaryngeal morbidity. From this observation it might be concluded that the invasiveness of the surgical intervention might also influence the tolerance for the airway instrument. The disadvantage in this study was the more difficult insertion of the PLMA compared with the oral intubation. Further studies with a larger number of patients must show if these first results of the "Proseal"-LMA for lararotomies are to be confirmed.

Adolescent↗
PubMed2005

Hemodynamic effects of spontaneous breathing in the post-operative period.

BACKGROUND: During mechanical ventilatory support, spontaneous breathing has been linked to improved hemodynamics. These findings may be explained by a decrease in intrathoracic pressure which may improve venous return to the heart. Such a mechanism should result in a dose-response relation between the amount of spontaneous breathing and an increase in the global end-diastolic volume (GEDV) and cardiac output (Q(t)). METHODS: To test this hypothesis, 15 patients were studied after major elective surgery during weaning from mechanical ventilation using bilevel positive airway pressure (BIPAP). BIPAP allows unrestricted spontaneous breathing during every phase of the respiratory cycle. Thus, ventilatory support was modified by changing the mechanical respiratory rate only, whereas inspiratory airway pressure and PEEP were kept constant. GEDV and Q(t) were measured by transpulmonary thermodilution. RESULTS: GEDV (P = 0.055), stroke volume (P = 0.027) and subsequently also Q(t) (P < 0.001) increased when spontaneous breathing increased. In contrast, no difference was observed for central venous pressure (P = 0.19). CONCLUSION: The beneficial hemodynamic effects of spontaneous breathing during mechanical ventilatory support can partially be explained by improved venous return to the heart which increases stroke volume and Q(t).

Adult↗
PubMed2004

[Blunt chest trauma with total rupture of the right main stem bronchus--a case report].

Tracheo-bronchial lesions in blunt chest trauma are rare--the incidence is about 1%--but potentially life-threatening events. Indirect signs such as pneumothorax, pneumomediastinum, subcutaneous emphysema or an insufficient expansion of the lungs after drainage of a pneumothorax are ominous. The fastest and most reliable method to assess the definite diagnosis of tracheo-bronchial lesion is fibre-optic tracheobronchoscopy. Early surgical treatment is mandatory to prevent major pulmonary resection. This case shows that computer tomography might fail to provide the right diagnosis. Independent lung ventilation is an option to protect the bronchial anastomosis during the early postoperative period. Reported here is the case of a young man who sustained a total traumatic rupture of the right main stem bronchus after being thrown from the passenger seat through the windshield of a motor vehicle. When the emergency doctor arrived on the scene, he found the patient with dyspnoea and massive thoracic subcutaneous emphysema. Reduced breath sounds on the left and no breath sounds on the right side led to an immediate placement of two chest tubes and controlled mechanical ventilation. After primary care in a district hospital, the patient was transferred to our university hospital for further treatment of his head injury. On admission, the patient was making breath sounds on both sides and a CT scan showed no clear sign of a tracheo-bronchial lesion. After neurosurgical intervention, the diagnosis of a rupture of the right main stem bronchus was made with delay by fibre-optic bronchoscopy. The patient was intubated with a left-sided double lumen endotracheal tube followed by surgical end-to-end anastomosis of the lesion. The initial postoperative ventilator support consisted of BIPAP-mode ventilation of the left lung, while the right lung was kept open with positive airway pressure. Forty-eight hours later, synchronised independent lung ventilation with two ventilators was established to protect the surgical result. The ventilation was switched to conventional mode a further 48 hours later. Extubation and the remaining ICU stay were uneventful.

Accidents, Traffic↗
PubMed2003

[Glaucoma in practices of ophthalmologists].

The aim of this study is to describe the prevalence of glaucoma among patients of office-based ophthalmologists on the basis of accounting data. The data can be taken from the so-called Patient-physician-panel for morbidity analysis (ADT panel) that has been developed by the Central Research Institute of Ambulatory Health Care in Germany. In this panel, the treatment data of patients treated by selected office-based physicians in North Rhine and Brandenburg are included. In both regions, 30 ophthalmologists were involved in the survey. The two random samples that have been performed, include the treatment data of nearly 55,000 patients from North-Rhine and of 58,000 patients from Brandenburg. The treatment prevalence of glaucoma with established diagnosis amounts to about 12% of the ophthalmologic patients in North Rhine and to about 13% in Brandenburg. If these figures are secondarily related to the total number of persons older than 39 years who are insured via social health insurance funds in these regions, the rates are 2.8 or 2.9% respectively. The majority of patients suffering from glaucoma (including suspected cases and exclusion diagnoses) underwent tonometry and it can be assumed that most of the patients received medical treatment. With the help of the morbidity panel, glaucoma patients with established diagnosis can be distinguished from those patients for whom this diagnosis has only been excluded and from cases where the suspicion remained unconfirmed. The standardised treatment prevalence of glaucoma almost amounts to the same rate in both regions. Ophthalmologists should use the additional specifications of the ICD-10 code more often (especially for cases of suspicion and exclusion). This would also lead to a higher significance of the ICD-10 terms indicated.

Adult↗
PubMed1998

Adaptive indirectly cooled monochromator crystals at HASYLAB.

The high-heat-load monochromator, based on the HASYLAB (Hamburger Synchrotronstrahlungslabor) 'Torii' design, has been used successfully for 2 years at the BW2 wiggler beamline. The bowing of the reflecting surface induced by the heat load and water pressure is compensated mechanically. This is achieved by mounting the specially shaped crystal in a bending mechanism and by heat transfer from the directly water-cooled crystal. We present the latest step in the development of this design. The piezoceramic-driven actuators are replaced by actuators based on the thermal expansion of copper rods. The direct water cooling of the crystal is replaced by a safer indirect water-cooling scheme. Characterization results of the crystal are presented. The Si(111) rocking-curve width at 9.5 keV was measured to be 8.3 arcsec under 500 W heat load.

Journal Article↗
PubMed1991

T cell receptor alpha and beta gene expression in a murine antigen-specific T suppressor lymphocyte clone with cytolytic potential.

The composition of alpha and beta TCR genes was analyzed in a murine BSA-specific Ts cell clone with cytolytic potential. The isolated poly(A)+ mRNA from Ts cell clone BVI/5 was used to construct a cDNA library in the bacteriophage lambda gt11. Full-length cDNA clones specific for TCR alpha and TCR beta genes have been detected and isolated by hybridization with specific oligonucleotide probes. The functional rearranged TCR alpha gene is composed of a member of the V alpha 1 family, the junctional gene J alpha TT11 and C alpha. The gene segments V beta 13, D beta 2.1, J beta 2.4, and C beta 2 form the functional rearranged TCR beta gene. Furthermore, a nonfunctional TCR alpha gene transcript has been detected, where a V alpha 8 gene is rearranged to a so far not described J alpha gene segment (J alpha BVI). A stop codon in its junctional region is responsible for this non-functional transcript. By using Southern blot analysis, the described rearranged TCR genes can be detected in the J alpha junctional region and in the J beta 2 cluster on the genomic DNA level. Immunoprecipitation studies with the KT3 anti-CD3 mAb and flow microfluorimetry analysis with the H57-597 anti-TCR-alpha/beta mAb show that TCR/CD3 complexes are synthesized and expressed on BVI/5 Ts cells. Taken together, the cDNA sequencing data, the protein studies, and the specificity of Ag recognition demonstrate that the BVI/5 Ts cell clone not only transcribes the TCR alpha and beta genes but also expresses a functional BSA-specific receptor.

Amino Acid Sequence↗
PubMed1990

[Chemosensitivity studies with soft agar culture systems in ovarian cancer].

Since 1982, chemosensitivity studies have been conducted in our laboratory with 181 tumour samples from 132 woman patients suffering from carcinoma of the ovaries, using the colony test and capillary assays. Colonisation rates were 67% and assay rates between 60 and 47%; in 36 cases the in vitro result was compared with the course of the disease observed in vivo. Whereas in 11 of 12 patients it was possible to correctly assess chemoresistance (in vitro growth inhibition less than or equal to 49%) pretherapeutically, chemosensitivity (growth inhibition greater than or equal to 50%) proved more difficult to confirm, 15 predictions being true and 9 false. To assess the prognostic significance of the test results, survival curves were calculated from the data of 33 patients. With a p-value of 0.49, the courses of disease of "in vitro resistant" and "in vitro sensitive" patients differed only slightly from one another. We can conclude from our experiments, that an important indication for performing the colony test in ovarian carcinoma should always be assumed in patients with a poor prognosis, e.g. in women having a large postoperative residual tumour. If, in such cases, the possibility of chemosensitivity testing via the colony test is considered, this examination may offer the chance of sparing the patient additional strain due to the side effects of a treatment with cytostatics if the latter is most likely to be of no significant use.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Specific in vivo suppression of lymph node cell proliferation and humoral immune responses by cloned antigen-specific T suppressor cells.

Two BSA-specific Ts cell clones have been isolated from CBA/J mice tolerized by low doses of BSA. Together with one Ts cell clone isolated from an immune animal, they have recently been characterized with regard to phenotypes and in vitro functions. In the present report the in vivo effector functions of two of them (Ts cell clones BVI/5 and HF1.MS) are described. BSA-primed lymph node cells from CBA/J mice, which had received BVI/5 or HF1.MS Ts cells at the time of immunization, do not respond to a subsequent in vitro antigenic challenge. A human gamma-globulin (HGG)-specific lymph node cell proliferation is not influenced. BVI/5 Ts cells injected into mice at the time of priming with fluorescein (Flu)-conjugated BSA or Flu-HGG inhibit the humoral anti-Flu-response in Flu-BSA-primed animals. The anti-Flu-response in Flu-HGG-primed animals is only marginally affected by BVI/5 Ts cells. The data show that it is possible to induce immunologic unresponsiveness at the humoral level by reexposing in vitro propagated Ts cell clones to their syngenic in vivo environment.

Animals↗
PubMed1988

[Experiences with PAC and PEC polychemotherapy in the treatment of advanced and recurrent breast cancers].

At the department of gynecology of the universities of Lübeck and Bonn 18 in part pretreated patients with advanced or relapsing cancer of the breast were treated with a DDP-containing polychemotherapy. For 14 of the 18 women the PAC or PEC regime was beneficial: 9 had complete or partial remission and 1 patient had a no change situation; 4 women showed no evidence of disease. The time of survival after the chemotherapy treatment was two month in the minimum and more than 50 month in the maximum (20 month in the average). As side effects, in particular leucocyte-depression and nausea as well as vomiting of various degrees were observed; alopecia was seen in every case. The success of DDP-containing chemotherapy in the treatment of breast cancer is of note, but in the future it will be important to define subgroups that would most benefit from PAC- or PEC-treatment without substantial negative side effects.

Adult↗
PubMed1987

An evaluation of the existence of soluble suppressor factors in cloned antigen-specific T suppressor lymphocytes.

The suppressive activity of two bovine serum albumin-specific class II-restricted T suppressor cell clones (BVI/5 and 83/2-D11) was compared to that of a feeder cell-independent, IL 2-dependent subline (HF1.IL-2) of an originally antigen-dependent class II-restricted Ts cell clone (HF1). No soluble suppressor factors can be found in BVI/5 and 83/2-D11 Ts cell extracts or culture supernatants under conditions where an unspecific factor can be derived from HF1.IL-2 cells. This factor, when isolated from cell extracts in the presence of n-octyl-beta-D-glycopyranoside, has a molecular weight of 70-80 kD. In absence of this non-ionic detergent, it has a high affinity to membrane fragments and is associated with a molecular weight of 300 kD or more. The data are discussed in connection with recent findings of direct T suppressor to T helper interaction by cell-cell contact.

Animals↗
PubMed1987

Isolation of a bovine serum albumin-specific T-suppressor cell clone and evaluation of its in vitro functions.

This communication describes a newly isolated T-suppressor (Ts) cell clone, BVI/5, derived from a CBA/J mouse tolerized to low doses of bovine serum albumin (BSA). The cells are Thy-1.2+, Lyt-1.1-, Lyt-2.1+, and express endogenous derived I-Ak and I-Ek molecules. BVI/5 Ts cells show antigen-specific I-Ek-restricted proliferation in the presence of antigen-presenting spleen cells. This proliferation can be inhibited by anti-I-Ek but not by anti-I-Ak monoclonal antibodies. In vitro antigen-specific suppressive capacity has been measured in a primed lymph node cell proliferation assay, and the fine specificity of these suppressor functions has been studied. Broader cross-reactivity in the specificity of this effector function is found if compared to the specificity of antigen-induced proliferation. The data extend previous findings on the expression of I-A and I-E molecules on Ts cells and are discussed with respect to the role of those cells in tolerance induction.

Animals↗
PubMed1986

Selective elimination through a cytolytic mechanism of bovine serum albumin-specific T helper lymphocytes by T suppressor cells with the same antigen specificity.

An antigen-specific T suppressor cell clone isolated from a CBA/J mouse tolerized to low doses of bovine serum albumin (BSA) has previously been analyzed with regard to its effector functions. The T suppressor cell clone HF1 specifically inhibits T helper cell responses to the antigen. It also has characteristic cytolytic activity which can neither be classified as cytotoxic T cell nor as natural killer cell activity. Since this lytic capacity might be of relevance in immunoregulation, it has now been studied in more detail. For that purpose BSA-specific T cell lines have been isolated from immune CBA/J mice in order to test them in 51Cr-release assays as possible targets for HF1 T suppressor cells. Two T cell lines, both BSA specific and restricted to recognition of I-Ek major histocompatibility complex determinants, have been selected for the studies because one is a helper cell (83/1), the other a suppressor cell type (83/2). HF1 T cells are able to lyse cells of line 83/1 but not those of line 83/2. Control experiments show that 83/1 cells are not a natural killer cell target and that on the other hand 83/2 cells are susceptible to lysis in an alloreactive BALB/c anti-CBA/J cytotoxic T cell response. The extent of lysis of 83/1 T cells by HF1 T cells changes with time after antigenic stimulation. The lysis is based on direct effector: target cell interaction and not caused by soluble mediators. The data are discussed with regard to the effector function of a type of T suppressor cells which expresses I-A and I-E molecules and whose proliferation is restricted to the recognition of I-A or I-E determinants.

Animals↗
PubMed1986

Expression of L3T4 molecules on Lyt-2+, class II-restricted antigen-specific T suppressor lymphocytes.

Three bovine serum albumin-specific Lyt-2+ T suppressor (Ts) cell clones from CBA/J mice have been analyzed with regard to expression of L3T4 molecules. All three Ts-cell clones can be stained with monoclonal antibodies (mAb) to L3T4. Tested for the two clones restricted to recognition of Ek determinants, antigen-specific proliferation on antigen-presenting cells, but not the proliferation induced by conditioned medium can be inhibited by L3T4-specific mAb. In a similar way, Ts-cell cytolytic effector functions can be blocked by L3T4-specific mAb. Thus L3T4 structures seem to play a role in Ts-cell functions. Furthermore, the data support the view that L3T4 expression can be a property of class II-restricted T cells irrespective of their Lyt phenotype.

Animals↗
PubMed1985

Functional studies on the role of I-A molecules expressed by the antigen-specific T suppressor cell clone HF1.

The antigen-specific T suppressor (Ts) cell clone HF1 (Thy-1.2+, I-Ak+, I-Ek+) was isolated from a CBA/J mouse tolerized to low doses of bovine serum albumin (BSA), and a subclone was adapted to grow in the absence of antigen-presenting cells. The functional role of the I-Ak molecules endogenously expressed by HF1 Ts cells was analyzed by using anti-I-Ak monoclonal antibodies (mAb) in attempts to block the antigen-induced proliferation of these cells. Among a panel of anti-I-Ak mAb tested, only the H118-49 mAb directed against the private determinant Ia.m1 blocked BSA-induced proliferation. The data presented here suggest a selective regulatory role of membrane-bound I-Ak molecules in the antigen-induced signal transmission.

Animals↗