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Biomedical subjects

W Mann

Publications and source records attributed to W Mann.

At least 127 records · Page 7Linked to original sources
PubMed1990

Identification of precipitable Ca2+ by electron spectroscopic imaging and electron energy loss spectroscopy in the organ of Corti of the guinea pig.

Ca2+ cations were precipitated with potassium antimonate in the cochlea of the guinea pig, and the formed precipitates were localized by electron microscopy using either elastically or inelastically scattered electrons. The elemental composition of the precipitates was determined by electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS). It was found that calcium, antimony and oxygen were the dominating elements in the precipitates formed in different cell types in the inner ear.

Animals↗
PubMed1990

[The Borrelia titer in ENT diseases].

In 139 patients with facial paralysis, sudden hearing loss, vertigo, and lymphadenitis of the head and neck, the prevalence of borrelia burgdorferi serum antibodies was examined with the help of immunofluorescence assays for IgG- and IgM-antibodies, immunofluorescence assays after absorption of cross-reacting antibodies with treponema phagedenis, ELISA, and Western Blot. Six out of 22 patients with facial paralysis, 11 out of 72 with hearing loss, eight out of 45 with vertigo, and five out of 25 with lymphadenitis of the head and neck were seropositive. These patients were compared with a control group of 52 patients without any clinical signs of Lyme disease. The control group consisted of patients admitted for surgery of septal deformities (n = 19), squamous cell carcinomas (n = 27), and pleomorphic adenomas of the salivary glands (n = 6). In nine out of 52 patients in the control group, antibodies against Borrelia burgdorferi were detectable. According to Fisher's exact test, there was no statistical difference between the two groups as regards the prevalence of seropositive patients. Lyme disease is a doubtful major etiologic factor in facial paralysis, sudden hearing loss, or vertigo.

Adult↗
PubMed1990

[Perioperative short-term preventive antibiotics in head-neck surgery].

A prospective perioperative trial with cefotiam and metronidazol was carried out in 114 patients undergoing head and neck surgery. The patients were stratified in one group receiving a single-dose prophylaxis and a second group receiving a 24-hour prophylaxis. The postoperative complication rates were analysed depending on various risk factors and the size and duration of surgery. For operations of similar size the long term prophylaxis had no advantage over the one-dose prophylaxis. It is concluded that a one-dose prophylaxis appears sufficient in major head and neck cases.

Cefotiam↗
PubMed1990

Interactions between group B streptococci and human cord blood lymphocytes.

Group B streptococci (Streptococcus agalactiae) of various serotypes (Ib/c, III/x, III/R, and B variant) and different sources of isolation were analyzed for their to interact with human mononuclear cells (MNC). Type I streptococci were obtained from a neonate dead of an invasive group B streptococcal infection. Examining the attachment of these bacteria to human peripheral lymphocytes and their ability to influence the proliferation of cultured adult and neonatal MNC, the following results were obtained: (1) Type Ib/c, III/x, and B variant strains adhered spontaneously to neonatal cord blood lymphocytes. The bacteria were bound by large lymphoid cells not detectable in the peripheral blood of adults. (2) Addition of group B streptococci to neonatal MNC cultures increased lymphocyte proliferation approximately 8 fold (n = 32) above the background. The reactivity of neonatal lymphocytes was highly reproducible with a mean peak proliferation close to day 5 of culture and a ratio of 60 CFU MNC. The control cell proliferation induced by Pokeweed mitogen (2 micrograms/ml) gave a mean stimulation index of 58. In contrast to cord blood cells, adult MNC responded only slightly with either proliferation of streptococcal binding. Clinical type I strain induced mean peak [3H]thymidine incorporation into neonatal MNC was approximately 16 times higher than into that of adults. Streptococcal adherence and lymphocyte activation did not depend on serotype specificity and clinical origin of the strains investigated. Therefore, the ability to interact with human cord blood lymphocytes seems to be a common property of group B streptococci.

Adult↗
PubMed1990

[Perioperative preventive use of antibiotics in head and neck surgery].

The results of five consecutive prospective trials define the role of perioperative antibiotic prophylaxis in head and neck surgery. For contaminated head and neck cases and for endonasal sinus surgery, a single-dose prophylaxis seems to be sufficient. Most clean cases do not need antibiotic prophylaxis. Risk factors for wound infection include nicotine or alcohol abuse, poor oral hygiene and increasing age. Previous radiotherapy seems to be of minor importance.

Anti-Bacterial Agents↗
PubMed1990

[Therapy of ear hematoma and ear seroma].

Conservative techniques for the treatment of auricular haematomas are unsuccessful. We discuss different operative methods and compare our results with these techniques. In our opinion the method described by Kelleher is a simple and reliable method for the treatment of auricular haematoma and seroma. After incision and evacuation of the fluid, tie-over sutures over wet sponges achieve efficient obliteration of the subperichondrial space. The most important advantages of the technique are that no resection of cartilage is necessary, the obliteration of the subperichondral space is stable, the cosmetic results are good, and the complication rate is low.

Ear, External↗
PubMed1989

Ultracytochemical localization of Ca2(+)-ATPase activity in the middle ear mucosa of the guinea pig.

Ca2(+)-ATPase activity was studied ultra-cytochemically in the middle ear mucosa of the guinea pig. On electron microscopic examination, the most intense reaction was found on the microvilli. Reaction products were also observed on the cilia and around and between the secretory granules on the apical side of the cells in their secretory phase. The basolateral membranes contained few reaction products, while very little or no activity was found on the basal membrane.

Animals↗
PubMed1989

Interactions between Sarcocystis gigantea lectin and toxin-containing fractions in human lymphocyte cultures.

Sarcocystis gigantea extract (SGE) was separated by affinity chromatography into one lectin-containing fraction (SGL) that was mitogenic to mononuclear cells (MNC) and another that lacked this lectin activity. The SGL-depleted Sarcocystis extract (SGTF) contained the so-called Sarcotoxin, inducing only a slight increase in MNC proliferation. Furthermore, preincubation of MNC with SGTF for 60 min suppressed the mitogenic capacity of SGL by 60%-90%. The results presented indicate that SGTF interacts with human MNC differently than SGL, particularly by interfering with the mitogenic lectin. These findings suggest that SGL and SGTF may be involved in different immunomechanisms induced by the parasite.

Animals↗
PubMed1989

The state of the frontal sinus after craniotomy.

In 39 patients, 24 male, 15 female, the frontal sinus was opened during a frontal, a bifrontal or a pterional trephination for neurosurgical treatment of trauma, tumours or aneurysms. In 25 out of 39 patients the frontal sinus subsequently was obliterated, in 11 out of 39 patients the apical half or 2/3 of the sinus were ablated and the remaining caudal part covered with a galea periosteal flap leaving the fronto-nasal duct intact. In 3 out of 39 patients, the periphery of the sinus was ablated and the remaining part covered. All patients were followed over a mean period of 2 years and had a final evaluation using CTs, X-rays, ultrasonography and a complete ENT examination. In 4 out of 25 obliteration was successful and complete, in 16 out of 25 there was a partial or complete re-aeration of the residual sinus and in 5 out of 25 the sinus was infected. In one out of eleven patients where the frontal sinus was bisected with preservation of the lower half, the basal part of the sinus was infected, in 10 out of 11 the residual sinus was aerated and draining well. In one out of three patients where the periphery of the sinus was ablated, there was infection, two of three sinuses were aerated. Evaluating the experience in these 39 patients and our recent experience, obliteration of the sinus with muscle is very unreliable and the use of bone wax is obsolete. Covering a bisected or peripherally opened sinus with fascia or a galea periosteal flap will yield a well aerated and draining sinus, provided the naso-frontal duct is intact.

Adolescent↗
PubMed1989

Isolation of DNA from yeasts.

Methods are described that allow DNA to be prepared from widely different yeasts (Candida utilis, Saccharomyces cerevisiae, and Schizosaccharomyces pombe). The methods are reliably reproducible, and the DNA obtained is of appropriate quality for the construction of gene libraries (upper limit of size range consistently 50-150 kbp). In method A, yeast cells are converted into spheroplasts by treatment with a highly purified mixture of enzymes from Trichoderma harzianum, the spheroplasts are lysed in a lauroylsarcosinate/EDTA buffer, and the lysate is incubated with proteinase K and then directly centrifuged through a cesium trifluoroacetate gradient. DNA is recovered from the appropriate fractions by ethanol precipitation, and the redissolved precipitate is incubated with ribonuclease. For the rest of the isolation, two protocols are given, one avoiding and one including phenol/chloroform extraction. In this way, DNA up to about 150 kbp in size can be obtained. In method B, spheroplasts are not made. Yeast cells are broken by grinding under liquid nitrogen and are then worked up in a manner similar to method A, protocol 2. Subsequent steps depend on the purpose for which the DNA is required. Traditional methods of sucrose or salt density gradient centrifugation or agarose gel electrophoresis are applicable for size selection. A sodium iodide/silica matrix technique allows fast and effective DNA recovery from agarose gels.

Centrifugation, Density Gradient↗
PubMed1989

[Malignant schwannoma of the ENT area].

Malignant schwannomas are uncommon in the head and neck. They are derived from Schwann cells of cranial, cervical or sympathetic nerves and occur as solitary tumours or in association with neurofibromatosis (von Recklinghausen's disease). We present a patient of 30 years of age with a tumour of the right nasal and paranasal sinus system and a 68-year-old woman with the first described intratracheal malignant epitheloid Schwannoma. After the diagnosis of a malignant Schwannoma wide surgical excision is the recommended treatment, depending on the individual case, eventually followed by radiation therapy. As the tumour is more aggressive in patients with neurofibromatosis, the prognosis is better for patients without neurofibromatosis.

Adult↗
PubMed1989

[Paranasal sinus tumors with orbital involvement].

Paranasal sinus tumors frequently extend into the bony orbital contents. In the past, their treatment often resulted in severe visual defects or consisted in enucleation. In an effort to determine whether an effective but more conservative form of therapy, is possible, 40 patients with such lesions were treated over the past 11 years by microsurgical resection followed by radiotherapy and/or chemotherapy. The present paper describes the authors' surgical technique, i.e. the transfrontal extradural approach and the midface-degloving-technique. In addition, the following parameters are evaluated specifically: 1) the effects of conservative resection on overall survival rate, 2) frequency of local disease recurrence and 3) changes in orbital function as a result of the combined therapy.

Aged↗
PubMed1989

[The value of ultrasound-controlled fine-needle biopsy in the diagnosis of possible neck tumors].

From October 1985 to July 1988 we performed a study to examine 106 patients with head and neck tumours, by using ultrasound as a guiding system for fine-needle aspiration biopsy. It could be shown that this method has a high diagnostic significance at the neck with a low rate of risks. In a first step puncture was effected to obtain material for cytology, if necessary also for a bacteriological examination. Normally, in a second step a fine-needle cutting biopsy was done to obtain histological material. The combined use of aspiration and cutting needle biopsy achieved correct tumour status in 91.5%, whereas in 73.6% the correct type of lesion was diagnosed. A false status assessment and errors in identifying the lesions occurred in 2 of 106 cases; there of was one false negative status assessment. In cases of benign neck cysts, neck abscesses and non-specific lymphadenopathy, a cutting neck biopsy is not required, provided the clinical diagnosis is in accordance with the result of aspiration cytology and the further clinical progress. The advantage of the ultrasound-guided puncture compared with palpation-guided puncture is the certainty of locating the region of interest even in deep lesions without an appreciable risk of complications. In our opinion, ultrasound-guided fine needle aspiration biopsy is indicated in all cases of unclear head and neck tumours which could be treated conservatively if the result of the puncture is non-malignant.

Abscess↗
PubMed1989

[Duplication of the auditory canal. A vestige of the 1st branchial cleft].

Anomalies of the first branchial cleft appear as duplicated auditory canals; they are rare clinical entities. Patients will present with a history of recurrent fistulas of the neck or parotid gland close to the angle of the mandible. There are two distinct malformations associated with the first cleft: A simple sinus which is lined with squamous epithelium and runs parallel to the auditory canal (Type I); the Type II anomaly, on the other hand, has a close, though variable relationship to the facial nerve and contains cartilage, a mesodermal derivate, within the wall. Embryologically it appears that the point of time at which the disorder developed dictates whether the malformation is of Type I or II. The authors present six cases of first branchial cleft anomalies, two patients with Type I and four with Type II lesions. The sex distribution was striking: all the patients were female. In case of a Type II defect, three variations of the facial nerve with split main trunks were found. Recurrent operations and infections lead to scar tissue and subsequent surgery is more difficult, with serious hazard to the facial nerve. Where positive identification of the facial nerve is a major problem it is advisable to identify the nerve in the mastoid cavity and trace it to the stylomastoid foramen and parotid gland.

Adolescent↗
PubMed1989

Juvenile angiofibromas: a 40-year surgical experience.

A series of 22 patients with histologically confirmed angiofibroma were treated primarily by surgical removal at the University of Freiburg ENT clinic during the 40-year period, 1946-1986. These tumors were staged according to size and extension on the basis of roentgenographic and surgical findings. Specific analysis of the operative approaches and recurrence rate by stage are included. Recurrent or residual disease was handled by surgical excision, irradiation, embolization, or a combination of these methods. The complication and morbidity rates were extremely low, while the mortality rate was zero. The tumor specimens received from the last 5 patients were evaluated for the presence of sex hormone receptors. No specific estrogen, progesterone or androgen receptors were detected in these tissues.

Adolescent↗