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Biomedical subjects

D Reiter

Publications and source records attributed to D Reiter.

At least 19 recordsLinked to original sources

Toroidal plasma rotation induced by the dynamic ergodic divertor in the TEXTOR tokamak.

The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating in the m/n=3/1 mode configuration, are presented. The deeply penetrating external magnetic field perturbation of this configuration increases the toroidal plasma rotation. Staying below the excitation threshold for the m/n=2/1 tearing mode, this toroidal rotation is always in the direction of the plasma current, even if the toroidal projection of the rotating magnetic field perturbation is in the opposite direction. The observed toroidal rotation direction is consistent with a radial electric field, generated by an enhanced electron transport in the ergodic layers near the resonances of the perturbation. This is an effect different from theoretical predictions, which assume a direct coupling between rotating perturbation and plasma to be the dominant effect of momentum transfer.

Journal Article↗

Prospective evaluation of novel system for jejunal feeding.

BACKGROUND: Enteral nutrition should be restored immediately after trauma, acute lesion, or surgical intervention. Nutrition through nasogastric tubes is often not feasible in patients in the posttraumatic state in medical intensive care units because of recurrent episodes of gastroesophageal reflux and subsequent aspiration due to gastric paresis. Placement of nasojejunal tubes with available techniques is unreliable. METHODS: We developed a new combined catheter system for jejunal delivery and simultaneous drainage of gastric juice (Cath-in-Cath, PreOx-RS, Germany). CONCLUSION: In this article, this new tube system is presented. The safety and excellent efficacy of the novel system for enteral nutrition therapy are reported in the first series of patients worldwide.

Enteral Nutrition↗

Laser resurfacing of silicone-injected skin: the "silicone flash" revisited.

OBJECTIVE: To determine whether prior silicone injection increases the risks associated with carbon dioxide laser resurfacing. DESIGN: Laboratory determination of the effect of laser energy on liquid silicone; histologic evaluation of silicone-injected skin after lasing; and histologic demonstration of silicone deposits in all layers of dermis years after injection of silicone as filler fluid. SETTING: Tertiary care medical center. PATIENT-RELATED DATA: Histologic examination of freshly excised skin injected with microdroplets of liquid silicone and subjected to application of carbon dioxide laser energy; histologic examination of skin excised years after silicone injection. INTERVENTIONS: High-speed clinical photographic imaging of the effect of laser energy on silicone fluid; histologic examination of hematoxylin-eosin-stained sections of skin injected with liquid silicone and subsequently lased. MAIN OUTCOME MEASURES: Response of liquid silicone to application of laser energy; effect of this response on surrounding normal skin. RESULTS: Exposure of microdroplets of liquid silicone to carbon dioxide laser energy produced flaring with frank flame. Flaring of dermal silicone caused collateral skin damage. CONCLUSIONS: Prior injection with liquid silicone is a relative contraindication to cutaneous resurfacing with the carbon dioxide laser. Surgical excision of silicone-injected skin may be preferable for many patients. A strenuous needs assessment should be done, alternatives for skin rejuvenation considered, and comprehensive informed consent obtained from the patient before embarking on laser resurfacing of silicone-injected skin.

Carbon Dioxide↗

Management of vocal fold scar with autologous fat implantation: perceptual results.

Vocal fold scar disrupts the mucosal wave and interferes with glottic closure. Treatment involves a multidisciplinary approach that includes voice therapy, medical management, and sometimes surgery. We reviewed the records of the first eight patients who underwent autologous fat implantation for vocal fold scar. Information on the etiology of scar, physical findings, and prior interventions were collected. Videotapes of videostroboscopic findings and perceptual voice ratings [Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS)] were randomized and analyzed independently by four blinded observers. Etiology of scar included mass excision (7), vocal fold stripping (3), congenital sulcus (2), and hemorrhage (1). Prior surgical procedures performed included thyroplasty (1), autologous fat injection (9), excision of scar (2), and lysis of adhesions (2). Strobovideolaryngoscopy: Statistically significant improvement was found in glottic closure, mucosal wave, and stiffness (P = 0.05). Perceptual ratings (GRBAS): Statistically significant improvement was found in all five parameters, including overall Grade, Roughness, Breathiness, Asthenia, and Strain (P = 0.05). Patients appear to have improved vocal fold function and quality of voice after autologous fat implantation in the vocal fold. Autologous fat implantation is an important adjunctive procedure in the management of vocal fold scar, and a useful addition to the armamentarium of the experienced phonomicrosurgeon.

Adipose Tissue↗

Identification of the stimulated hemiretina in primary school children and adults based on left and right hemifield pattern reversal visual evoked potentials--a comparative study.

OBJECTIVES: The analysis of left and right hemifield pattern-reversal visual evoked potentials (PVEPs) in children and the identification of the stimulated hemiretina testing different identification procedures previously applied to adults. METHODS: Lateral hemifield PVEPs were recorded in 40 children (6-11 years) and 27 adults (25-40 years) from, at least, 19 standard electrodes. Two procedures were tested for the determination of the stimulated hemifield: firstly, the evaluation of the values of instantaneous frequency at the occipital electrodes at P100 latency (determined by the global field power), and secondly, the application of a generalised dynamic neural network (GDNN) using the PVEP time course at selected electrode positions as the external input. RESULTS: P100 latency as well as P100 amplitude over the contralateral occiput in children were significantly greater than in adults. Contrary to the behaviour in adults, instantaneous frequency is not a robust identifier of left and right hemiretina stimulation in children. The best identification performances were achieved when using group trained GDNNs with the bipolar difference signals of electrodes P3/P4 or T5/T6 as the external input. CONCLUSIONS: The PVEPs at electrodes P3/P4 and T5/T6 contain essential information for the determination of the stimulated hemifield. This should be further considered during the development of on-line procedures for automatic PVEP detection in future studies.

Adult↗

Node counts in neck dissection: are they useful in outcomes research?

OBJECTIVES: We studied the unilateral nodal yields for procedures reported as standard or modified radical neck dissection (RND) to determine their applicability in outcomes research. METHODS: We analyzed the unilateral nodal yields for all procedures reported as RND for carcinoma of the oral cavity, pharynx, and larynx at our institution from 1985 to 1997 (n = 64, no prior treatment). These included both standard and modified techniques, encompassing levels I through V of the neck. Each side of a bilateral RND was treated as a separate case. This sample was compared with a similar population from the National Cancer Institute's Surveillance, Epidemiology, and End-Results (SEER) registry. Nodal yield was obtained for RND alone and for unspecified neck dissection with primary excision for the same diseases and time period (n = 1499). RESULTS: The mean nodal yield from 64 RND was 30 vs 27 in the SEER data. The standard deviation was 14.7 compared with 17.2 in the SEER data. Values ranged from 7 to 66 nodes whereas the SEER range was from 1 to 97 nodes. Although the SEER data contain nodal yields from regional or selective neck dissection, we corroborate our findings of large variance in nodal yield from our RND sample. CONCLUSIONS: Large variance in nodal yields from RND may have undefined effects on quality of life, cure rate, and survival. Until correlation of nodal yields with outcomes is examined, we cannot know how to relate RND to outcomes.

Carcinoma, Squamous Cell↗

Ear piercing for individuals with metal hypersensitivity.

OBJECTIVE: To describe and evaluate an ear piercing and earring retention method for individuals with metal hypersensitivity. SETTING: Private facial plastic surgery practice associated with a tertiary care medical center. METHODS: Thirty-one patients with a history of hypersensitivity to metallic jewelry (62 ears) underwent earlobe piercing with an intravenous catheter. RESULTS: None of the patients experienced an infection or hypersensitivity reaction. All patients were able to wear nickel-free earrings for short periods without using the shortened catheter. CONCLUSION: Using the distal shaft of an intravenous catheter as an earring post sheath is a safe and effective technique that allows hypersensitive individuals to wear earrings in pierced ears on a limited basis.

Catheterization↗

Security aspects of teleradiology between the university centre and outlying hospitals in Tyrol.

We assessed a data security system using biometric fingerprint techniques and smartcards to control access to a teleradiology system. Clinical cases were initially discussed between the referring physician and radiologist in Tyrol using a video-phone. Subsequent correspondence, including the transmission of images between the referring physician and the radiologist, was carried out by e-mail using the security system to prevent unauthorized access to patient information. Seventy-eight teleradiology sessions were conducted using this data security system. Speed and stability of data exchange were unaffected by the additional security feature. The average log-on time to the system was 7.8 s. The average training time on how to use the system was 15 min. The radiologist was able to issue a final patient report using the system within 1.5 of the initial contact. The data security feature was user-friendly and did not hinder the normal teleradiology consultation.

Austria↗

Tumefactive cartilage proliferation after rhinoplasty. A newly reported complication.

OBJECTIVE: To describe and document the development of tumoral proliferation of cartilage in 4 patients after nasal surgery, a complication that, to our knowledge, has not been reported before. DESIGN: Similar postoperative nasal masses were excised from 4 patients who underwent rhinoplasty. Histopathologic evaluation was carried out to identify the nature of the lesions and to provide a basis for rational management of similar lesions subsequently encountered. SETTING: Academic tertiary referral center. PARTICIPANTS: Four healthy patients (3 women and 1 man) ranging in age from 21 to 49 years. Two of the patients underwent routine rhinoplasty with resection of cephalic margins of alar cartilages, and 2 underwent augmentation procedures with implantation of auricular cartilage. INTERVENTION: Discrete firm masses were excised from each patient's nose approximately 1 year after the most recent rhinoplastic procedure was performed. Histological evaluation was carried out on each specimen. RESULTS: All 4 masses were found to consist of tumefactive proliferation of cartilage. Clonal proliferation and mild nuclear atypia were observed. CONCLUSIONS: After rhinoplasty, progressive asymmetrical fullness in or adjacent to cartilaginous structures or graft material should suggest the possibility of tumefactive proliferation of cartilage and should be evaluated with surgical exploration. All areas of thickened cartilage should be excised completely, with immediate auricular cartilage reconstruction of resulting anatomical defects. Perichondrium should be completely removed from auricular cartilage implants in the nose, and mechanical injury to the graft should be minimized. We strongly caution against morsellizing dorsal cartilage implants for nasal reconstruction.

Adult↗

Isolated Castleman disease of the neck: MR findings.

Castleman disease in an 11-year-old girl appeared as a neck mass that grew despite antibiotic treatment. MR showed a well-defined solid mass, isointense with muscle on short-repetition-time/short-echo-time images, with a stellate area of central hypointensity on long-repetition-time/long-echo-time images, that did not enhance with gadolinium.

Castleman Disease↗

Methods and materials for wound closure.

Over the years, a number of different modalities have become available to close wounds. Before selecting a method of wound closure, the characteristics of the specific tissues to be closed and the anticipated time for wound healing to occur must be considered. This article reviews the methods available for tissue closure for the head and neck surgeon.

Animals↗

Torn earlobe: a new approach to management with a review of 68 cases.

The torn earlobe is a common problem, yet no objective analysis of causation or management is found in the literature. We present a series of 68 patients with statistical data on earlobe characteristics and cleft-related historical factors. We describe three new methods of repair: two for full clefts and one for partial clefting (ie, elongation of the piercing site without penetration of the inferior rim). We report follow-up from 4 to 10 years, with a 91% success rate for lobe appearance and a 1.2% recurrence of clefting. We offer guidelines for repair and repiercing based on lobe thickness and shape. We make recommendations for earring use based on lobe characteristics and historical development of the defect.

Adolescent↗

Fetal wound healing.

Wound healing research has produced some startling discoveries during the past decade. Foremost among these is the observation that cutaneous wounds created and healed in utero are histologically indistinguishable from intact, unwounded tissue. Observers have documented that the acute inflammatory response and endogenous immunoglobulins that characterize healing in human beings after birth are absent in the fetal wound. Determination of the cellular and biochemical differences between fetal and postdelivery wound healing offers the promise of improved control over the process of tissue repair. Another promise of fetal wound healing research is the option of in utero repair of defects such as cleft lip and palate. We review what is known at present about fetal wound healing.

Extracellular Matrix↗

Methods and materials for wound management.

Rumor, myth, and unsubstantiated opinion have guided wound management since our forebearers achieved upright ambulation. The past decade has seen discovery of specific substances and pathways that initiate, control, and terminate healing. The roles of oxygen, nutrition, and growth factors are rapidly revealing themselves to wound healing researchers, and a scientific basis for wound management is emerging. Although the healing process still harbors much mystery, we know enough to improve our methods of wound management. We can now pick from a variety of tools for surgical incision. Scientific studies help in the choice of sutures, needles, and needle holders, as well as alternative closure methods and materials. Natural and synthetic tissue adhesives vie with staples and tapes for use in wound repair. Dressing materials may be active, passive, selectively interactive, or inert. Wound management can be changed to meet changing wound needs, with dressings as diverse as hydrocolloids, silicone gels, and amino acids. We have new ways of improving hypertrophic scarring and practical hopes for its prevention. This article offers a summary of currently available methods and materials for wound management, along with the scientific information that supports and guides their use.

Bandages↗

Alternatives to packing in septorhinoplasty.

Nasal packing is considered routine by most physicians and patients at the completion of nasal and septal surgery. Yet the rationale for this maneuver is not clearly defined by reported investigation or logical analysis. We discuss 75 consecutive nasal surgical procedures completed without packing. There were two postoperative episodes of bleeding, both from pyriform aperture incisions for lateral osteotomy and both managed in the recovery room with an absorbable gelatin sponge. Technical refinements such as scrupulous preoperative history taking, through-and-through suturing of the entire septal flaps, small-caliber osteotomy, meticulous closure of all intranasal incisions, and proper application of a conforming dressing are essential for hemostasis. We offer specific procedural guidance to minimize the risk of postoperative nasal bleeding.

Adolescent↗

Invasive intramuscular hemangiomas of the head and neck.

Intramuscular hemangiomas make up less than 1% of all hemangiomas [1]. These invasive and aggressive lesions appear to have a predilection for large muscle masses. They can be strikingly aggressive in the head and neck, and persistence despite radical treatment is common. Spontaneous resolution in adults to our knowledge has not been reported in the literature. We present a case report of an invasive intramuscular hemangioma involving the parotid gland, the masseter and pterygoid muscles, and the infratemporal fossa after local resection of an apparently isolated lesion of the lip and the submandibular triangle. We describe a detailed course of treatment and review the literature.

Adult↗