Interlimb conditioning of lumbosacral spinally evoked motor responses after spinal cord injury.

OBJECTIVE: The importance of subcortical pathways to functional motor recovery after spinal cord injury (SCI) has been demonstrated in multiple animal models. The current study evaluated descending interlimb influence on lumbosacral motor excitability after chronic SCI in humans. METHODS: Ulnar nerve stimulation and transcutaneous electrical spinal stimulation were used in a condition-test paradigm to evaluate the presence of interlimb connections linking the cervical and lumbosacral spinal segments in non-injured (n=15) and spinal cord injured (SCI) (n=18) participants. RESULTS: Potentiation of spinally evoked motor responses (sEMRs) by ulnar nerve conditioning was observed in 7/7 SCI participants with volitional leg muscle activation, and in 6/11 SCI participants with no volitional activation. Of these six, conditioning of sEMRs was present only when the neurological level of injury was rostral to the ulnar innervation entry zones. CONCLUSIONS: Descending modulation of lumbosacral motor pools via interlimb projections may exist in SCI participants despite the absence of volitional leg muscle activation. SIGNIFICANCE: Evaluation of sub-clinical, spared pathways within the spinal cord after SCI may provide an improved understanding of both the contributions of different pathways to residual function, and the mechanisms of plasticity and functional motor recovery following rehabilitation..

Large-scale evaluation of multimodal biometric authentication using state-of-the-art systems.

We examine the performance of multimodal biometric authentication systems using state-of-the-art Commercial Off-the-Shelf (COTS) fingerprint and face biometric systems on a population approaching 1,000 individuals. The majority of prior studies of multimodal biometrics have been limited to relatively low accuracy non-COTS systems and populations of a few hundred users. Our work is the first to demonstrate that multimodal fingerprint and face biometric systems can achieve significant accuracy gains over either biometric alone, even when using highly accurate COTS systems on a relatively large-scale population. In addition to examining well-known multimodal methods, we introduce new methods of normalization and fusion that further improve the accuracy.

Quantum key distribution with 1.25 Gbps clock synchronization.

We have demonstrated the exchange of sifted quantum cryptographic key over a 730 meter free-space link at rates of up to 1.0 Mbps, two orders of magnitude faster than previously reported results. A classical channel at 1550 nm operates in parallel with a quantum channel at 845 nm. Clock recovery techniques on the classical channel at 1.25 Gbps enable quantum transmission at up to the clock rate. System performance is currently limited by the timing resolution of our silicon avalanche photodiode detectors. With improved detector resolution, our technique will yield another order of magnitude increase in performance, with existing technology.

[Healing process of cartilage attached to a polydioxanone implant]. / Heilungsprozess des Knorpels in Verbindung mit PDS-Folie.

BACKGROUND AND OBJECTIVE: To correct severe septal deformities, it is often necessary to perform an extracorporal septoplasty with temporary removal of the deviated septal cartilage, followed by straightening and reimplantation into the nose as free graft. The utilization of a compound graft, which sutures the cartilage fragments to a resorbable polydioxanon (PDS) foil, facilitates this technique immediately while simultaneously ensuring support of the nasal dorsum. PATIENTS/METHODS: On account of the good clinical experiences (during the past 3 years 71 patients have been treated using this method), we investigated the biological properties of the foil and its degradation products in connection with cartilage in an animal model from a histological point of view. In five rabbits, a 0.15-mm-thick PDS foil was implanted in combination with the cartilage into the outer ear. The follow-up period was between 2 and 25 weeks. RESULTS: The results showed the following: (1) Up to the tenth week, the foil maintains the original structure; (2) The foil will be completely resorbed after 25 weeks; (3) The cartilage underneath the foil is protected from necrosis; (4) The degradation products of the polydioxanon do not interfere with the healing process; (5) Concerning the regeneration of cartilage, the foil acts as a guarding splint; (6) After resorption, almost no scar tissue remains. CONCLUSIONS: Due to the fact that the PDS foil endonasal implant means no additional risk to the patient, we can recommend the compound graft for simplification of extracorporal septoplasty.

Clinical and histological results of septoplasty with a resorbable implant.

BACKGROUND: The use of a resorbable implant connected with septal cartilage would facilitate external septoplasty, offering mechanical stability until the cartilage fragments heal. OBJECTIVE: To study the histological and clinical results of septoplasty with a resorbable implant (polydioxanone [PDS; Ethicon, Norderstedt, Germany]) in conjunction with cartilage. DESIGN: To provide histological information in 5 rabbits, PDS foil was implanted into the outer ear in conjunction with an artificial cartilage defect. Observations were made at 2, 5, 10, 15, and 25 weeks. Resorption of the implant was investigated, including the time to complete elimination. In addition, septoplasty with PDS foil was performed on 71 patients with severe septal deformities. Surgery consisted of excision of the quadrilateral cartilage and division into straight fragments, which were sutured to the PDS foil and replaced as a free graft. SETTING: Ear, nose, and throat department of the General District Hospital Steyr, Steyr, Austria. RESULTS: Histological examination showed that the foil remained unchanged for at least 10 weeks and was completely resorbed after 25 weeks with minimal remaining scar tissue. Newly formed cartilage developed bordering the cartilage defect. In the clinical study, all patients experienced varying degrees of improvement in nasal blockage. No immediate or long-term complications occurred. CONCLUSIONS: The use of PDS foil in connection with cartilage facilitates surgical correction of severe septal deformities, additionally providing support for the nasal dorsum. The histological examination showed that no inflammatory or foreign body reaction occurred. Cartilage regeneration was even found. The foil was completely resorbed within 25 weeks, avoiding the long-term complications that occur with other artificial implants.

[Septum reconstruction with PDS implant]. / Septumrekonstruktion mit PDS-Folie.

To achieve septoplasty without compromising the surgical goal of attaining a straight and solid septum, even in cases of marked deviations or severe post-traumatic deformities, we now use a new technique in which the septal reconstruction includes the placement of a resorbable implant as a "compound graft." For this purpose the entire septal cartilage is removed, and the severely deviated part is divided into straight sections that are reconnected to each other to form a straight and solid plate. As connecting material we use a polydioxanon (PDS) foil. The sections of cartilage are sutured to the foil with PDS suture material. The compound graft thus constructed consists of the septal cartilage and resorbable alloplastic material and is reimplanted into the nose. The PDS and suture material are usually resorbed within 8 months, excluding long-term complications. During the past 2 years this method was used in treating 38 patients. The surgical goal was attained in every case, and no immediate or long-term complications occurred. This method of combining septal cartilage with a resorbable implant leads to a better, significant correction of even severe septal deviations.

Tubomanometry. Values in ears with traumatic and chronic perforations.

The tubal function of 68 patients with a unilateral traumatic perforation of the tympanic membrane and 116 ears of 94 patients with chronic otitis media were examined by equalization manometry. The values obtained in the traumatic group are regarded as being characteristic of normal tubal function: the patients were able to equalize +/- 30 hPa difference in pressure with between three and seven swallows. Only 25% of the ears with a dry central perforation and none with an infected central perforation were able to fulfil this requirement.

Manometric determinations of pressure changes in the external auditory meatus caused by a patulous eustachian tube.

The pressure changes developing in the nasopharynx and in the external auditory canal during breathing at rest were examined by means of manometry in patients with patulous eustachian tubes and in healthy control subjects who were able to keep their eustachian tubes opened for prolonged periods of time. Findings demonstrated that pressure changes in the nasopharynx in both groups were practically the same, but pressure changes in the external auditory meatuses of the patients with patulous tubes were about one order greater than in the control group. This occurrence might be caused either by relaxation of the fibers of the tympanic membrane or by different degrees of opening of the eustachian tubes.

[Nasolith removal with ultrasound lithotripsy]. / Nasensteinentfernung mittels Ultraschallithotriptor.

We report a rhinolith that caused total nasal obstruction and that could not be removed simply. It was reduced in size by a lithotripter, as used for stone disintegration in urology, and then removed. This method is suggested in all cases where removal of the rhinolith cannot be performed non-invasively and the rhinolith can be seen by the endoscope.

[Tubal manometry: the question of normal values, values in chronic mesotympanic purulent middle ear infections]. / Tubenmanometrie: Frage der Normalwerte, Werte bei chronischen mesotympanalen Mittelohreiterungen.

We investigated tubal function by equalization manometry in 68 patients with unilateral traumatic perforation of the tympanic membrane, and in 116 patients with chronic mesotympanic suppuration (85 dry and 31 discharging ears). Our criterion of normal tubal function is the ability to equalize a difference in pressure of +/- 30 hPa by means of at most 7 swallowings. This result was achieved in only 25% of the dry perforations and in none of the patients with discharging ears. Normal tubal function may only be expected in 25% of patients with chronic otitis media.