Unexpected photochemical reactivity of ruthenium(II) polypyridine complexes induced by a bis(bidentate) phosphine.
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Journal Article↗
Biomedical subjects
R Gutmann
Publications and source records attributed to R Gutmann.
[Extracranial schwannoma of the ENT region. Review of the literature with a case report of benign schwannoma of the base of the tongue].
BACKGROUND: Schwannomas are benign, usually solitary, encapsulated neoplasms which arise from the Schwann cells of the nerve sheath. They often originate from the VIIIth cranial nerve. Extracranially, about 25% of all Schwannomas are located in the head and neck. The lateral cervical region and the mouth are the most common sites. Schwannomas arising from the base of the tongue are very rare, and only a few cases have been reported so far. CASE REPORT: We add the case of a 31-year-old woman who had been suffering from slowly increasing dysphagia for about 4 years. Examination revealed a firm, smooth-shaped, nodular swelling about 3.0 cm in diameter arising from the base of the tongue. SYMPTOMS AND DIAGNOSIS: The symptoms of Schwannomas are nonspecific, and depend on size and location. Sonography, CT or MRI may be helpful for estimation of the tumor margins and infiltration of surrounding structures. To confirm the diagnosis, however, microscopic examination is necessary. Characteristic histological signs are the palisading of the spindle-shaped Schwann cells around the central acellular area (so-called Verocay bodies). THERAPY AND PROGNOSIS: The therapy of choice consists of surgical removal of the tumor; Schwannomas do not recur if they are completely removed. In contrast to multiple neurofibromas (von Recklingshausen's disease) Schwannomas almost never undergo malignant transformation.
Adult↗
[Initial results with MRI-controlled laser-induced interstitial thermotherapy of head and neck tumors].
Laser-induced interstitial thermo-therapy (LITT) was introduced as a minimally invasive form of therapy for tumors in different anatomic regions. However, in the orofacial region, it has not been used so far for inoperable T4 carcinomas. Since vascular and neural structures are often close to the tumor or are even involved, online monitoring of LITT is necessary. The aim of our study was to establish a method of monitoring LITT with MRI (magnetic resonance imaging) in the orofacial region. Five patients with T4 carcinomas of the orofacial region underwent LITT under anesthesia. A 1.5 T whole-body imager with a circular polarized head coil was used. Before and after the intervention, the region of interest was studied using T1- and T2-weighted sequences in axial and coronal planes, with and without contrast enhancement (intravenous Gd-DTPA). Temperature distribution was monitored with a T1-weighted 2D-FLASH (fast low angle shot) sequence. The positioning of the optical fibers was monitored with MRI. Nd:YAG laser equipment was used for laser application. The necrosis was best seen on contrast-enhanced MRI. Immediately after LITT, the outcome could be determined by MRI. We proposed that MRI-guided LITT be used for neoplasms in the orofacial region at advanced stages.
Aged↗
Fluorescence imaging and spectroscopy of 5-aminolevulinic acid induced protoporphyrin IX for the detection of neoplastic lesions in the oral cavity.
BACKGROUND: Semiquantitative fluorescence measurements following topical application of 5-aminolevulinic acid (5-ALA) in 16 patients with neoplastic lesions of the oral cavity were performed. METHODS: Time course and type of porphyrin accumulation were analyzed in neoplastic and surrounding healthy tissue by measuring emission spectra of 5-ALA-induced protoporphyrin IX fluorescence. Fluorescence images in the red and green spectral range from the tumor tissue were recorded with a charge-coupled device camera. RESULTS: Protoporphyrin IX fluorescence was detected in the oral mucosa of all patients after local application of 5-ALA. Protoporphyrin IX in neoplastic tissue accumulated earlier in comparison with the surrounding normal tissue. The maximum fluorescence contrast of 10:1 between tumor and host tissue was generally seen 1-2 hours after application, allowing a demarcation of tumor tissue even with the naked eye. CONCLUSION: Labeling of mucosal lesions of the oral cavity with Protoporphyrin IX fluorescence induced by the local application of 5-ALA seems to be a promising diagnostic procedure for neoplastic lesions that are difficult to visualize under white light examination. It is the aim of further investigations to evaluate the relevance of this new diagnostic procedure as a noninvasive and sensitive method for patients with oral cancer.
Administration, Topical↗
MRI-guided laser interstitial thermal therapy (LITT) of head and neck tumors: progress with a new method.
A less invasive method for treatment of tumors is being tested based on interstitial photothermal ablation via infrared Nd:YAG laser fiber optics. The technique can be applied safely and effectively for therapy of common tumors in humans. In the current study five patients were treated by interstitial laser palliation with the Nd:YAG laser using special fiberoptic applicator tips, which distribute laser energy efficiently throughout the tumor volume. Magnetic resonance imaging (MRI) scanning was employed to locate the tumor, position the fibers correctly, and monitor the development of thermal necrosis in the tumors. Two patients were diagnosed with adenoid cystic carcinoma of the paranasal sinuses, one with a recurrent carcinoma of the tongue and oropharynx, one with a recurrent carcinoma limited to the oropharynx, and one patient with a carcinoma of the epi- and oropharynx. The maximum follow-up without recurrence was 2 years in a patient with an adenoid cystic carcinoma tumor of the paranasal sinuses. There were no immediate or delayed complications. Anatomical structures including eyes, brain, and important vessels were recognized by MRI during laser therapy. MRI-guided interstitial laser photothermal ablation appears to be a safe and effective method for treatment of selected tumors of the head and neck region with particular applications in palliation of inoperable tumor recurrences.
Aged↗
[Piracetam infusions in acute tinnitus and sudden deafness].
In a prospective randomised clinical study on 39 patients with tinnitus and sudden hearing loss the therapeutic efficacy of piracetam/HAES 6% was compared with that of naftidrofuryl/HAES 6%. The two groups of patients were comparable in terms of demographic and audiological baseline data. The parameters evaluated were hearing improvement and the reduction in intensity of tinnitus. Improvement in hearing was 15 dB (piracetam) versus 18.5 dB (naftidrofuryl). The improvement in tinnitus amounted 27 dB (piracetam) and 19.9 dB (naftidrofuryl). Both differences were not significant. Tolerability was very good in both groups. Piracetam, which improves rheology and has a positive effect on metabolism, would appear of particular interest for the treatment of acute tinnitus.
Acute Disease↗
[Photodynamic diagnosis and therapy of neoplasms of the facial skin after topical administration of 5-aminolevulinic acid].
Topical application of 5-aminolevulinic acid (5-ALA) is a useful instrument for photodynamic diagnosis and therapy of skin tumours. Diagnostic fluorescence imaging after laser light irradiation (410 nm) revealed a high, tumour-specific fluorescence even in tumour areas not apparent prior to this examination technique. This demonstrates the possibility of photodynamic diagnosis to detect skin tumours. In the therapeutic group 8 patients with 6 solar keratoses and 12 basal cell carcinomas underwent laser light irradiation using a wavelength of 635 nm (dosage 100 J/cm2) 6 hours after topical application of 5-ALA in W/O emulsion. 2-12 hours after laser application we observed reddened tumour tissue with mild oedema, subsequently followed by a crust and epithelised within 4-6 weeks. 2 months after PDT a complete response was observed for all solar keratoses and for 10 of 12 basal cell carcinomas. Photodynamic therapy following topical application of 5-ALA may be an alternative treatment modality for skin tumours.
Administration, Topical↗
[Clinical and electron microscopy study of sudden deafness treatment with the 10% HES 200/0.5 and pentoxifylline combination].
The incidence of sudden hearing loss has increased. The pathogenetic mechanisms are still unknown, but viral infections and vascular phenomena with acute impairment of microvascular perfusion are thought to play a major role. Infusion of hydroxyethyl starch (HES) is used as a regimen to treat sudden hearing loss. In our clinic, anaphylactic reactions due to HES have not been observed so far. However, the use of HES is still discussed controversially due to long-term storage of HES molecules in tissue and due to high incidence of long-lasting pruritus. In a retrospective analysis of 118 patients treated with HES for sudden hearing loss, we observed pruritus starting in 64% of patients one to three weeks after therapy. This symptom with a duration between two weeks and four months was refractory to medical interventions. During therapy with HES improvement of hearing was observed in 75% of patients, in 62% improvement of hearing persisted still at the end of the observation period (7 months post infusionem). Light and electron microscopic assessment of human skin biopsies of one patient after treatment with HES showed storage of HES especially within dermal macrophages. Pathogenetically a pathway independent of histamin seems responsible for the induction of pruritus. Accordingly, classic antihistaminic drugs had no therapeutic effect in our patients. Dextran is used as an alternative to hydroxyethyl starch. In contrast to HES, the often mentioned higher incidence of severe anaphylactic reactions due to dextran has dramatically decreased with hapten inhibition (after preinjection of monovalent haptendextran Promit).(ABSTRACT TRUNCATED AT 250 WORDS)
Auditory Threshold↗
[Endoscopic and extracorporeal shock wave lithotripsy of salivary calculi].
Shock wave lithotripsy of salivary gland stones has become more and more efficient in the treatment of sialolithiasis during the last years. We use two different methods in our hospital: Extracorporeal shock wave lithotripsy (ESWL) and endoscopically intracorporeal lithotripsy (EISL). The results of both therapies are compatible; 60-70% could be successfully treated. The indication is different due to the localisation of the salivary gland stone. Stones that are located in the glandula or very proximal in the duct should be fragmented by extracorporeal lithotripsy. Stones located in the duct and multiple intraductal stones should be treated by the intracorporeal method. Clinical experiments showed that some salivary stones do not fragment easily. The reason is still unknown. We examined the ability of fragmentation in relation to the physicochemical analysis of the stone. The stones were examined by infrared spectroscopy. This study revealed that pure carbonate apatite stones are more difficult to destroy than stones containing some protein.
Combined Modality Therapy↗
[Rare complications of soft tissue infections in the head and neck area: deep neck phlegmona, thrombophlebitis and mediastinitis with pericardial effusion].
Cervical phlegmona is a rare occurrence associated with infections of the ENT region. Spreading of the infection can cause thrombophlebitis, mediastinitis and cardiac tamponade. Three recently treated patients are reported who showed serious complications due to harmless primary infections of the oral cavity, oropharynx or throat. The clinical course of the diseases with the sometimes difficult examinations undertaken and the performed treatment are outlined. Computed tomography and radiography of the lung were useful in confirming the diagnosis, establishing that the infection had spread into deep neck spaces and into the mediastinum. Surgical therapy including extensive surgical drainage of the deep neck spaces and of the mediastinum, multiple antibiotic therapy, and intensive care, resulted in survival of the patients.
Adult↗
[Photodynamic laser therapy in the field of otorhinolaryngology].
A clinical study was conducted on the application of photodynamic therapy on tumours in the head and neck region to assess the value of this new modality for superficial cancer (Tis-T2). Patients with recurrent laryngeal papillomatosis were included in a photodynamic treatment pilot study. 2 mg/kg body weight of haematoporphyrin-derivative (Photosan-3) was administered 48 hours prior to laser irradiation intravenously. The patients rooms were advised to avoid daylight for two to three weeks. Tumours of the facial skin were irradiated homogeneously by means of an optical bench. Directly after laser application we observed an extensive extravasation of the tumour tissue, whereas the surrounding normal tissue showed mild erythema. A dry crust formed subsequently, which disappeared within two weeks associated with re-epithelisation. Mucous membrane tumours showed fibrin layers in the tumour area 24 hours after laser application with selective tumour necrosis. These lesions also epithelised completely within three weeks. Scarring never occurred. Laryngeal tumours as well as laryngeal papillomas were treated by a cylindrical light applicator system and the patients admitted to intensive care unit for 24 hours after laryngoscopy because of risk of laryngeal oedema. 94 patients with tumours of the head and neck with different histological origins were treated photodynamically, as well as 21 patients with laryngeal papillomatosis. Two months after photodynamic laser treatment, controlled biopsies of the former tumour area were performed. 5 patients had a relapse during a maximum follow-up of 4.5 years. This signified a histologically confirmed full response rate of 95%, accompanied by good plastic and functional results.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Importance of increased interstitial fluid pressure in therapy of malignant tumors of the head-neck area].
Animal experiments showed that elevated interstitial fluid pressure (IFP) is associated with poor blood supply and inadequate supply of drugs to solid tumours. IFP is approximately 0 mmHg in most normal tissues. Up to now there have been only few studies showing elevated interstitial pressure in human tumours in situ: Mammary carcinomas, cervical carcinomas and colorectal cancers have an elevated IFP. We measured IFP in squamous cell carcinomas of the head and neck region in humans using the "wick-in-needle" technique. In all lesions (n = 25), the IFP was elevated (4-39 mmHg). The IFP increased with tumour size. The highest IFP was 39 mmHg in a 26 ml tumour. These results show that squamous cell carcinomas of the head and neck region in humans have an elevated interstitial fluid pressure. The elevation of IFP associated with inadequate delivery of drugs to the interstitium of malign tumours may reduce the response to therapy.
Carcinoma, Squamous Cell↗
[Incidence of Doppler ultrasound detectable stenoses of cervical arteries in patients with cochlear-vestibular symptoms].
Doppler ultrasound examination is an easy and non-invasive examination technique to image the anatomical and functional situation of cervical vessels. An increasing number of ENT-specialists has been using Doppler sonography in the diagnosis of cochlear and vestibular disorders. We analysed the frequency of pathological Doppler examination results of 150 patients with vertigo, hearing loss and tinnitus. Especially patients with vertigo bear a greater risk for stenosis of the extracranial arteries (28%) compared to an asymptomatical population (1%). Patients with hearing loss and tinnitus showed a different degree of artery disorders (23% of the patients with hearing loss; 18% of the patients with tinnitus). Patients bearing no risk for atherosclerosis showed in 13% (vertigo) and 8% (hearing loss and tinnitus) stenosis of the cervical arteries. Thus we found by Doppler ultrasound examination more stenoses in patients with cochlear or vestibular symptoms than in an asymptomatical population. The early attribution of stenosis to a malfunction of the inner ear helps to avoid invasive examinations of cervical vessels. In addition to this, imminent cerebral ischaemia can be revealed at an early stage.
Aged↗
Interstitial hypertension in head and neck tumors in patients: correlation with tumor size.
Elevated interstitial fluid pressure (IFP) is associated with poor blood supply and inadequate delivery of drugs to solid tumors. IFP was measured in squamous cell carcinomas of the head and neck region in humans using the wick-in-needle technique. In all lesions (n = 19), the IFP was elevated (4-33 mm Hg). Furthermore, the IFP increased with tumor size. The highest IFP was 33 mm Hg in a 24-ml tumor. In one tumor, the IFP was found to be negative (-2.6 mm Hg), which is comparable to that in human skin or subcutaneous tissue. The histopathology of this tumor was benign. If this pressure difference between malignant and benign lesions can be confirmed in a large number of tumors, then the IFP could be used to aid tumor detection during needle biopsy. The value of IFP as a predictor of response to radiotherapy, photodynamic therapy, hyperthermia, and chemotherapy should be assessed prospectively.
Aged↗
[Does the otorhinolaryngologist need Doppler sonography?].
Doppler sonography has not only proved to be a non invasive but also a highly sensitive diagnostic tool for imaging of functional vascular disorders. The otorhinolaryngologist who in future will have to deal with an increasing number of neurootological problems, such as tinnitus, vertigo and hearing loss, should cover the Doppler sonographic examination of the vertebral and carotid artery and its branches. Ultrasound examination of these vessels should be performed in all patients suffering from cochlear or vestibular disorders and bearing risks for arteriostenosis. Early diagnosis does not only point out causative vascular changes but also helps to prevent the patients from invalidising or lethal cerebral events. The combination of (Doppler- and B-mode-sonography Duplex sonography) enables the ENT specialist not only to rule out functional vessel disorders but also to look for morphological vascular changes. Duplex scan imaging is far less risky than angiographic procedures and in many cases it is superior to these invasive techniques too.
Blood Flow Velocity↗
Heparin reversal by protamine in humans--complement, prostaglandins, blood cells, and hemodynamics.
Fourteen noncardiac surgical patients received heparin (10,000 IU), which was neutralized by 100 mg protamine injected within 2 min during steady-state anesthesia. After protamine application, plasma complement C3a, thromboxane B2 (TxB2), prostaglandin F2 alpha (PGF2 alpha) and KH2PGF2 alpha increased significantly, whereas prostacyclin (6-keto-PGF2 alpha) levels did not change. This mediator response was associated with transient leukopenia and thrombocytopenia. Arterial pressure, pulmonary arterial pressure, and transpulmonary pressure gradient increased significantly. Heart rate, cardiac output, pulmonary capillary wedge pressure, and arterial PO2 remained constant. Positive correlations of plasma C3a were observed with pulmonary leukosequestration and plasma TxB2. Inverse correlations of C3a were noted with the counts of leukocytes and of platelets. A positive correlation was found between TxB2 and pulmonary arterial pressure. Our results indicate that marked activation of the complement system and the cyclooxygenase pathway is common after heparin reversal by protamine in anesthetized patients. This is in contrast to previous human studies performed after cardiopulmonary bypass but agrees well with results obtained in animal experiments. The mediator response in our patients, however, was not accompanied by hemodynamic instability, suggesting appropriate compensatory mechanisms.
Aged↗
Pulmonary hypertension after heparin-protamine: roles of left-sided infusion, histamine, and platelet-activating factor.
Severe pulmonary hypertension after protamine neutralization of heparin is an infrequent but life-threatening event following cardiopulmonary bypass. The effect of left ventricular infusion of protamine on pulmonary hypertension as well as a possible role of platelet-activating factor (PAF) or histamine in the heparin-protamine reaction was investigated in 30 pigs in four different groups during general anesthesia. Group 1 animals received 250 IU/kg heparin, followed by 100 mg protamine intravenously after 15 min. In group 2 protamine was infused into the left ventricle. Group 3 animals received the histamine H1- and H2-antagonists clemastine and ranitidine 5 min before protamine infusion. In group 4 the PAF receptor blocker WEB 2086 was given 5 min before protamine. Platelet-activating factor was measured by a bioassay in serum samples of group 1 and group 4 animals. In all four groups protamine caused severe pulmonary hypertension, thromboxane A2 release, and a transient decrease in leukocyte counts. No PAF release was detected after protamine infusion. Neither left ventricular infusion of protamine nor histamine or PAF antagonists prevented or attenuated the reactions after protamine infusion. The authors conclude that left ventricular infusion of protamine provides no protection from pulmonary hypertension, and that histamine and PAF are not involved in the acute pulmonary vasoconstriction after protamine neutralization of heparin.
Animals↗
Thromboxane mediation of pulmonary hemodynamic responses after neutralization of heparin by protamine in pigs.
Protamine neutralization of heparin is often associated with severe hemodynamic side-effects, including pulmonary hypertension and systemic hypotension. Because prostanoids may be involved, the authors studied the role of arachidonic acid metabolites, especially thromboxane A2, in this process. During anesthesia with enflurane and fentanyl, four groups of pigs were studied: Group 1 (n = 10) received heparin (250 IU/kg), followed by protamine (100 mg) after 15 minutes to neutralize the heparin. The same protocol was used in group 2 (n = 11), except that the thromboxane A2 receptor antagonist BM 13.177 (10 mg/kg) was infused 5 minutes before the protamine. The protocol for group 1 was also used for group 3 (n = 7) except that these animals were pretreated with indomethacin (10 mg/kg). Animals in group 4 (n = 10) were given protamine only (100 mg). Pulmonary artery pressure and pulmonary vascular resistance increased significantly in group 1 after protamine neutralization of heparin. This was accompanied by significant increases in plasma concentrations of the cyclooxygenase products thromboxane B2, 6-keto-prostaglandin F1 alpha, and prostaglandin F2 alpha. Cyclooxygenase products increased to comparable degrees in group 2, but without hemodynamic effects. Leukocyte counts decreased comparably in both groups. Hemodynamic reactions, as well as changes in plasma prostanoid levels were absent in group 3, and group 4, but leukocyte counts were less affected in animals that received protamine alone. The results indicate that the hemodynamic side-effects of protamine are mediated by prostanoids and that thromboxane A2 release is the pivotal step, because side effects were effectively prevented by pretreatment with a thromboxane receptor antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗