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Biomedical subjects

T Mewes

Publications and source records attributed to T Mewes.

13 recordsLinked to original sources
PubMed2005

Rapid Rhino: A new pneumatic nasal tamponade for posterior epistaxis.

OBJECTIVES: Some of these measures to control posterior epistaxis cause loss of nasal respiration and put the patient on those related risks. STUDY DESIGN AND METHODS: The efficiency of a new pneumatic nasal tamponade (Rapid Rhino) was compared with a choanal balloon tamponade that has been used in our department for years in a prospective randomized study in patients with posterior epistaxis. The new pneumatic tamponade was used on the affected side only and nasal ventilation of the contralateral side was possible. RESULTS: Because of the successful use of the new pneumatic tamponade in most of the patients, epistaxis could be controlled without bilateral obstruction of nasal respiration. The use of the new pneumatic tamponade was evaluated to be less painful by the patients than choanal balloon tamponade. CONCLUSION: In an adapted therapeutic regime, the new pneumatic tamponade seems to have its place before using bilateral nasal respiration obstructing measures.

Aged↗
PubMed2005

The effects of short-term immunotherapy using molecular standardized grass and rye allergens compared with symptomatic drug treatment on rhinoconjunctivitis symptoms, skin sensitivity, and specific nasal reactivity.

BACKGROUND: The efficacy and safety of short-term immunotherapy with molecular standardized allergens (STI) has been demonstrated by double-blind placebo-controlled clinical trials. The aim of this study was to compare STI with symptomatic drug treatment. METHODS: Forty-eight patients with rhinoconjunctivitis to grass and/or rye pollen were treated either with STI (ALK(7), n = 24) plus anti-allergic drugs or anti-allergic drugs, alone (n = 24) in a prospective, randomized study. Symptoms and use of drugs were reported in patient diaries and titrated nasal provocation and skin prick tests were performed at baseline, before, and after season. RESULTS: Median overall symptom (P = 0.022, U test) and medication scores (P = 0.003) were significantly lower in the STI group, as was the result for a simultaneous analysis of conjunctival, nasal, and bronchial symptom scores and medication (P = 0.005). Sensitivity in the nasal provocation test decreased in the STI group but not in the drug-treated group. These differences became significant directly after STI (P = 0.027) as well as after the grass pollen season (P < 0.001). Skin sensitivity did not change in the STI group but increased in the drug-treated group after season, with a significant difference between the two groups for the erythema (P < 0.001). CONCLUSIONS: STI reduces grass pollen-induced rhinoconjunctivitis symptoms and drug use, and specific nasal reactivity and skin sensitivity, more efficiently than a standard symptomatic treatment.

Adolescent↗
PubMed2003

[Percutaneous dilatative tracheostomy versus conventional surgical tracheostomy: a retrospective trial].

BACKGROUND: In this retrospective study we compared endoscopically controlled percutaneous dilatative tracheostomies (PDT) with conventional surgical tracheostomies as a bedside procedure and in the operating theatre. PATIENTS: Between 1998 and 2000 we performed 360 tracheostomies electively, 152 in PDT-technique (42 %) and 208 (58 %) with the conventional procedure. Referring to the PDT-technique 74 % (n = 112) were performed at the bedside and 26 % in the operating theatre. The conventional tracheostomies took place at bedside in 53 % (n = 110) and in the operating theatre in 47 % (n = 98) of the cases. The complications were divided in 5 groups with special interest if the operation took place in the operating theatre or as a bedside procedure. RESULTS: In general the rate of complications in the PDT group was 33 % (50/152) versus 22 % (46/208) referring to the conventional group. Referring to the PDT group the rate of complications were 35 % (39/112) at the bed site procedure and 28 % (11/40) in the operating theatre. The complication rate for the conventional group was 27 % (30/110) as a bedside procedure versus 16 % (16/98) in the operating theatre. Significant differences were found for the PDT with an increase of tubal obstructions (p = 0.007). For the conventional tracheostomy we found a significant increase of wound infections (p = 0.006). There was significantly higher postoperative hemorrhage if the procedure was done at bed site. CONCLUSION: PDT and conventional tracheostomies have different complications. The higher risk of postoperative hemorrhage for bed site procedure has to be considered.

Adolescent↗
PubMed1999

The effect of short-term immunotherapy with molecular standardized grass and rye allergens on eosinophil cationic protein and tryptase in nasal secretions.

BACKGROUND: Activation of mast cells and eosinophils under pollen exposure can be inhibited by specific immunotherapy. OBJECTIVE: The effect of short-term immunotherapy with 7 preseasonal injections of molecular standardized allergens from grass and rye pollen on eosinophil cationic protein (ECP) and tryptase levels in nasal secretions has been compared with symptomatic drug treatment in an open, randomized study with 48 patients. METHODS: Nasal reactivity and mediator levels in nasal secretions were measured at baseline, before season, in season, and after season. RESULTS: Symptom scores in the immunotherapy group were 134.5 (95% CI, 65 to 336) versus 386. 0 (95% CI, 185 to 563), significantly lower as in the drug-treated group. ECP and tryptase levels increased significantly during natural allergen exposition. The seasonal levels in the immunotherapy group were significantly lower than in the drug-treated group with 272.1 ng/mL (252.0 to 293.9 ng/mL; immunotherapy) versus 470.4 ng/mL (SEM, 435.6 to 508.0 ng/mL; drugs) for ECP and with 8.73 ng/mL (SEM, 8.20 to 9.29 ng/mL) versus 17.47 ng/mL (16.42 to 18.60 ng/mL) for tryptase (all, P <.001). The ECP level induced by nasal provocation was 105.6 ng/mL (99.0 to 112.6 ng/mL) versus 180.4 ng/mL (169.2 to 192.4 ng/mL), significantly lower (P <.001) in the immunotherapy group, as was the tryptase level with 12.12 ng/mL (11.53 to 12.75 ng/mL) versus 8.19 ng/mL (7. 79 to 8.62 ng/mL; P <.001) at the after-season visit. CONCLUSION: Short-term immunotherapy is able to reduce tryptase and ECP in nasal secretions more effectively than drug treatment in patients with allergic rhinitis.

Adolescent↗
PubMed1998

[Function of the eustachian tube in epitympanic retraction pockets].

There are different hypotheses for the development of epitympanic retraction pockets. These can occur as the result of an inflammatory process and negative pressure in the middle ear spaces. Anatomic bottlenecks in the middle ear favor diminished inflation of the epitympanic space. The eustachian tube provides pressure equilibration in the middle ear. Its dysfunction involving tubal opening or closing is thought to be the main reason for a permanent negative pressure in the middle ear. A patulous eustachian tube is now claimed for prolonged negative pressure in the middle ear and is caused by a so-called "sniffing" habit. The purpose of this study was to elucidate objectively the frequency of patulous eustachian tubes in ears with epitympanic retraction pockets. We examined passive tubal function in 41 patients with 50 epitympanic retraction pockets by using dual impedance in a pressure chamber. We identified three stages of epitympanic retraction pockets. Stage 1 involved a mobile and controllable retraction pocket; stage 2 corresponded with a fixed but controllable pocket, whereas stage 3 described a fixed pocket that was developing into a cholesteatoma. Results were compared with the function tests of 100 healthy ears in 50 normal individuals. We found 27 patulous eustachian tubes in patients with epitympanic retraction pockets, 22 of which occurred in affected ears while only 2 patulous tubes were found in the group of the healthy ears. Tubal opening pressure (P < 0.001) and tubal closing pressure (P < 0.01) were significantly lower in ears with epitympanic retraction pockets than in healthy ears.

Adult↗
PubMed1998

[Arachnoid cyst of the sphenoid sinus].

BACKGROUND: Arachnoid cysts of the paranasal sinus are rare. They have not been described yet in the sphenoid sinus. PATIENT AND METHOD: Microscopic-endoscopic endonasal surgery of the sphenoid sinus was performed on a 34-year-old female with a history of chronic headaches and a suspected mucocele of the sphenoid sinus in computed tomography (CT) and magnetic resonance imaging (MRI) studies. An extended arachnoid cyst was found in the enlarged sphenoid sinus, which was obliterated with collagen, fibrin glue, and abdominal fat. RESULTS: There were no complications after the operation, and 12 months later the patient is still free of symptoms. CONCLUSION: Arachnoidal cysts present in CT and MRI as fluid dense lesions that can imitate a mucocele.

Adult↗
PubMed1997

[Reproducibility and seasonal dependence of specific intranasal provocation tests in birch pollen allergy patients].

BACKGROUND: The intranasal allergen Provocation test (INT) is the standard procedure to verify the effect of an allergen when a nasal allergy is suspected. It may be especially useful if results from skin tests or in vitro tests conflict with those from the history. In the clinical and research setting, INT may be used to study the efficacy of different treatment modalities such as pharmacotherapy or immunotherapy. The technique of INT has not been well standardized in the past. Variations exist in planning the optimum time for testing, especially in seasonal allergies. METHODS: We examined influences of different test dates with regard to the pollen season on the result of INT. A total of 19 patients (eight females, 11 males, aged 26.1 +/- 4.8 years) with a history of at least two years of allergic rhinitis to birch pollen, positive skin prick test, and RAST (> or = CAP class II) to birch pollen. INT was performed during the winter-period after approximately six months without natural pollen exposition (V1), during the birch pollen season (V2) and six weeks after the birch pollen season (V3). Allergens were applied using a pump spray (0.1 ml) in concentrations of 10, 50, 100, 500, 1000, 5000, 10,000, 50,000, and 100,000 SQ units per ml (SQ/ml). RESULTS: The threshold concentrations were significantly lower at V2 (100 SQ/ml) and V3 (500 SQ/ml) if compared to V1 (1000 SQ/ ml). CONCLUSIONS: Seasonal influences should be taken into account when performing INT in birch pollen allergy.

Adolescent↗
PubMed1996

Increased in vitro cysteinyl leukotriene release from blood leukocytes in patients with asthma, nasal polyps, and aspirin intolerance.

In vitro cysteinyl leukotriene (cLT) release from blood leukocytes was measured in eight normal individuals (NI), nine patients with nasal polyps (NP) without aspirin intolerance, and eight patients with NP, asthma, and aspirin intolerance (AI). Blood leukocytes were prestimulated with interleukin-3 (IL-3) and incubated with acetylsalicylic acid (ASA) (10 and 100 micrograms/ml) together with C5a (10(-8) mol/l) for 18 h. cLT release (LTC4, LTD4 and LTE4) from blood leukocytes was measured with a competitive enzyme-linked immunoassay. Background cLT release was 259 +/- 66 pg/ml (mean +/- SEM) in the NI group, 185 +/- 33 pg/ml in the NP group, and 578 +/- 136 pg/ml in the AI group (P = 0.1). After incubation with 10 micrograms/ml ASA, cLT concentration was lower in normal subjects (346 +/- 72 pg/ml) and in patients with NP (209 +/- 53) than in patients with AI (686 +/- 75 pg/ml, P = 0.002). After incubation with 100 micrograms/ml ASA, cLT concentrations were 285 +/- 72 pg/ml in the NI group, 313 +/- 77 pg/ml in the NP group, and 654 +/- 121 pg/ml in the AI group (P = 0.04), respectively. Simultaneous incubation with ASA 10 micrograms/ml and C5a (10(-8)mol/l) resulted in a cLT concentration of 751 +/- 171 pg/ml in the NI group, 343 +/- 102 pg/ml in the NP group, and 2196 +/- 480 pg/ml in patients with AI (P = 0.0006), whereas simultaneous incubation with ASA 100 g/ml and C5a (10(-8)mol/l) resulted in 268 +/- 51 pg/ml in the NI group, 412 +/- 97 pg/ml in the NP group, and 1701 +/- 368 pg/ml in the AI group (P = 0.005). In patients with AI, cLT release from blood leukocytes is altered when compared with normals and patients with NP. The presented cLT-release assay could be of potential use in the in vitro diagnosis of AI.

Adult↗
PubMed1996

Electrophysiology of ion channels of the heart.

The contribution of Na+, Ca2+, and various K+ currents to the shape of the cardiac action potential is outlined based on the relation between electrophysiological properties and structure of channel molecules. These currents have also been found in human ventricular myocytes, where the most prominent K+ current is a transient outward current that is not influenced by methylsulfonanilide antiarrhythmic drugs. Combined knowledge of electrophysiological and molecular properties of ion channels is likely to form the basis for rational design of future drugs.

Action Potentials↗
PubMed1994

L-type calcium currents of human myocytes from ventricle of non-failing and failing hearts and from atrium.

L-type calcium currents were studied in ventricular myocytes isolated from non-failing hearts, i.e. donor hearts not suitable for transplantation, and from severely failing hearts, i.e. explanted hearts of organ recipients, in order to identify possible alterations of the currents in cardiomyopathy. Human atrial myocytes were investigated for comparative purposes. As deficient production of cyclic AMP might contribute to the development of cardiac failure, the responses to forskolin, a direct stimulator of adenylyl cyclase, were also studied. The patch-clamp technique was applied in the single electrode whole-cell mode. Calcium currents were similar in myocytes from non-failing and failing hearts: Maximum current-densities were 3.8 v 3.1 pA/pF, and 2.2 pA/pF in atrial cells. In human ventricular cells, threshold was at -33 mV, maximum at +6 mV and reversal potential at about +50 mV, potentials of half-maximum steady-state inactivation -24 mV and -18 mV. The slopes of steady-state inactivation curves were +4.1 mV in myopathic and +5.5 mV in non-failing cells. In all myocytes the current inactivated with two time constants, a fast one with weak and a slow one with pronounced potential dependency. Ventricular or atrial myocytes from patients pretreated with calcium antagonists and untreated did not differ in current density or steady-state inactivation. Forskolin (0.5 microM) increased calcium currents in myocytes from non-failing and failing hearts to the same extent (by 143 and 150%). While beta-adrenoceptor numbers are reported to decline in severely failing myocardium, our data do not suggest that alterations of the properties of calcium currents contribute to the pathophysiology of heart failure, though the number of investigated hearts is limited due to restricted access to non-failing cardiac tissue. No evidence for impairment of the signal transduction cascade beyond the level of GTP binding proteins was found.

Adenylyl Cyclases↗
PubMed1993

Activation of calcium currents in cardiac myocytes by empty beta-adrenoceptors.

BACKGROUND: The cardiac calcium channel is known to be modulated by catecholamines via beta-adrenoceptors acting through intermediary GTP-binding regulatory proteins (G proteins). In biochemical studies on isolated membranes and reconstituted systems, it has been demonstrated that various G protein-coupled receptors, including beta-adrenoceptors, can activate G proteins and also intracellular second messengers like cyclic AMP (cAMP) even in the absence of an agonist and that antagonists can block this empty receptor action. We examined electrophysiologically whether agonist-free beta-adrenoceptors can modulate L-type calcium currents (ICa) in intact cardiac myocytes. METHODS AND RESULTS: Cardiomyocytes were isolated from ventricles of guinea pig and human hearts and from human right atrial appendage. The patch-clamp technique was applied in the single electrode mode to measure whole-cell ICa. Modulation of calcium currents by beta-adrenoceptor antagonists, without addition of an agonist, was studied in the absence and presence of the direct adenylyl cyclase activator forskolin and the cAMP analog adenosine cyclic 3',5'-monophosphorothioate (Sp-cAMPS). In the presence of forskolin (0.5 mumol/L), an agent known to sensitize the adenylyl cyclase signal transduction system for receptor regulation, addition of the beta 1-selective antagonist atenolol and the nonselective antagonist propranolol (but not of the beta 2-selective antagonist ICI 118,551) caused a marked reduction of ICa in a concentration-dependent and stereoselective manner. The inhibitory effect of atenolol was reversible after washing out and was found to be half maximal and maximal (50% reduction) at about 50 and 300 nmol/L, respectively. In the absence of forskolin, inhibition of ICa by atenolol was markedly less (18% at 10 mumol/L atenolol). Finally, in contrast to forskolin-stimulated currents, atenolol (1 mumol/L) did not reduce calcium currents activated by the protein kinase A activator Sp-cAMPS (0.1 mmol/L), causing by itself a similar increase in calcium currents as forskolin. CONCLUSIONS: In isolated guinea pig and human cardiomyocytes, agonist-free beta-adrenoceptors are functionally active and can stimulate L-type calcium currents, an effect blocked by receptor-specific antagonists.

Animals↗
PubMed1989

The Kasabach-Merritt syndrome: severe bleeding disorder caused by celiac arteriography--reversal by heparin treatment.

Studies are presented on a 62-yr-old woman with extreme hepatomegaly due to a giant hemangioma with alterations in the clotting system indicating a consumption coagulopathy. There was a fall of hemoglobin, fibrinogen, antithrombin III, and platelet number after arteriography of the truncus celiacus. Furthermore, there was sustained bleeding in the patient's right thigh caused by puncture of the arteria femoralis. Continuous administration of iv heparin corrected the clotting disorder including a rise in platelets from 95,000/microliters to 148,000/microliters, permitting surgical removement of the hematoma. Celiacography is a useful tool for the diagnosis of hepatic hemangiomata, as well as ultrasound, computed tomography, and magnetic resonance imaging. Being an invasive technique, it requires testing for possible consumption coagulopathy if used in patients with hemangiomatosis. Its application should be restricted to cases in which exact diagnosis cannot be established by other means.

Angiography↗