Titanium osseointegrated implants combined with hyperbaric oxygen therapy in previously irradiated mandibles.

Statement Of Problem: Treatment for head and neck malignancies commonly involves radiation therapy. As a result of this therapy the vascular supply to irradiated structures is altered and results in decreased tissue perfusion. In addition to vascular changes, bony structures undergo a reduction in osteoblastic and osteoclastic activity.

Energetic consequences of coordinating wingbeat and respiratory rhythms in birds.

The coordination of ventilatory and locomotor rhythms has been documented in many birds and mammals. It has been suggested that the physiological significance of such coordination is a reduction in the cost of ventilation which confers an energetic advantage to the animal. We tested this hypothesis by measuring the external work required to ventilate birds mechanically during simulated flight.

Impression technique for nonosseous free-tissue transfer reconstruction after cranioorbitomaxillary resection: A clinical report.

The use of vascularized free-tissue transfers has given the head and neck surgeon the ability to offer enhanced oncologic therapy with less risk of exposing vital structures to the aerodigestive tract. Resulting free-flap tissue consistencies and contours inhibit the successful use of routine impression techniques. The technique described in this clinical report uses a previously reported procedure to obtain an accurate impression of residual palatal and free-flap structures.

Risk factors for advanced-stage oral cavity cancer.

Objective: To assess the association between risk factors for inadequate surveillance of oral cavity cancer and stage of disease (localized, T1, T2/N0 vs advanced, T1, T2/N1-3, T3, T4/N0 or N1-3).

Design: Convenience sample from a case series.

Setting: Otolaryngology clinic in a tertiary care hospital.

The communicating vein and its use in the radial forearm free flap.

Thrombosis is the most frequent cause of failure in microvascular free-tissue transfer. The large communicating vein of the cubital fossa connects the deep and superficial venous drainage of the radial forearm free flap (RFFF). This vein allows the surgeon to simultaneously drain both systems by means of the large veins of the cubital fossa.

Chondroid syringoma of the head and neck: clinical management and literature review.

This report describes the case of a chondroid syringoma occurring in the nasofacial groove of a 60-year-old woman. This benign, mixed epithelial tumor is infrequently seen by the otolaryngologist-head and neck surgeon, and therefore may not be included in the differential diagnosis of a nodular lesion on the skin of the head and neck. However, the most frequent site of occurrence for these relatively rare cutaneous lesions is the head and neck region.

Microvascular replantation of a traumatically amputated ear.

We describe the replantation of a traumatically severed auricle using microvascular anastomosis to reestablish blood flow to the ear. Microvascular reattachment of the severed auricle occurred 10 hours after the trauma. Postoperatively, adjunctive measures, including anticoagulation and the use of medicinal leeches, were used to relieve venous congestion of the replanted auricle.

Rhythmical oral-motor activity recorded in an in vitro brainstem preparation.

The present study employed the neonatal rat isolated brainstem preparation to determine whether oral-motor rhythmical activity, a substrate for the complex behaviors of suckling and chewing, could be elicited in vitro by path application of excitatory amino acids (EAAs). Bath application of EAA agonists (kainate [KA], [+/-]-a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid [AMPA], N-methyl-D, L-aspartate [NMA]), in conjunction with the gamma-aminobutyric acid antagonist bicuculline, either failed to induce rhythmic activity (n = 17 preparations) or induced a low-amplitude, low-frequency burst discharge (< 1 Hz, n = 10 preparations) from the motor branches of the trigeminal nerves when the brainstem was contiguous from the spinomedullary junction to the superior colliculus. Burst activity was in most cases bilaterally synchronous.

Generation of respiratory rhythm and pattern in mammals: insights from developmental studies.

Our understanding of the cellular, synaptic and network mechanisms underlying respiratory rhythm generation in mammals is progressing rapidly as researchers focus on a site hypothesized as the source of rhythm generation, the preBötzinger complex, in the rostral ventrolateral medulla. Furthermore, ontogenetic and modulatory factors affecting respiratory neuronal circuits are receiving considerable attention, as postnatal development of motor systems becomes increasingly apparent.

Liver function studies in the assessment of head and neck cancer patients.

Background: Serum liver function tests (LFTs) are used in the initial evaluation of patients with head and neck squamous cell carcinoma (SCC) to evaluate hepatic function and to screen for liver metastases.

Methods: One hundred forty patients initially seen with SCC between 1988 and 1991 were followed for a minimum of 2 years to determine the significance of abnormal LFTs at presentation.

Results: Abnormal values were found in 69 patients (49%), including elevated alkaline phosphatase in 37 (26%) and lactic dehydrogenase in 25 (18%).

The role of magnetic resonance angiography in head and neck surgery.

Magnetic resonance angiography (MRA) is a recently developed, noninvasive vascular imaging technique. The authors of this investigation assessed the diagnostic value of MRA, along with its influence on therapeutic decisions, in 11 patients with a variety of head and neck disorders. In 5 patients, MRA diagnosed or ruled out an intrinsic vascular lesion.

Anomalies of forearm vascular anatomy encountered during elevation of the radial forearm flap.

Background: The radial forearm flap has gained considerable popularity over the past 10 years. With the increasing number of forearm flaps being used in head and neck reconstruction, it is likely that anomalous forearm vascular anatomy will be encountered by more head and neck surgeons performing this procedure.

Methods: We reviewed our experience with 52 forearm flaps; four different anomalies of forearm vascular anatomy were encountered in four patients.

Modulation of neural network activity in vitro by cyclothiazide, a drug that blocks desensitization of AMPA receptors.

To determine whether AMPA receptor channel desensitization has a physiological role in shaping network activity by modulating signal transmission through excitatory circuits, we examined the effects of cyclothiazide (CYT), the most potent known blocker of AMPA receptor desensitization, on the behavior of an endogenously active neural system in vitro, the brainstem network generating rhythmic respiratory oscillations in neonatal rat medullary slices. Bath application of 100 microM CYT significantly increased the frequency of endogenously generated rhythm and increased the amplitude of the circuit output [i.e.

Induction of a hepatic toxic syndrome in the Dutch-belted rabbit by a quinoxalinone anxiolytic.

The non-benzodiazepine anxiolytic, panadiplon, was discontinued from clinical development due to evidence of hepatic toxicity in human volunteers that was not predicted by rat or monkey preclinical development studies. The present study was conducted to examine potential toxicity in the rabbit. Three groups of female rabbits were administered vehicle, 10 mg/kg per day or 20 mg/kg per day of panadiplon by oral gavage for 14 days.

Free-tissue transfer reconstruction of midfacial and cranio-orbito-facial defects.

Objective: To review our results using free-tissue transfer to reconstruct midfacial and cranio-orbito-facial defects.

Design: Case series.

Setting: The University of Iowa Hospitals and Clinics, Iowa City.

Pacemaker behavior of respiratory neurons in medullary slices from neonatal rat.

1. We have hypothesized that pacemaker neurons in the pre-Bötzinger complex (pre-BötC) form the kernel for respiratory rhythm generation. A prediction of this hypothesis is that oscillatory behavior in some respiratory neurons could persist in the absence of synaptic transmission.

Development of thyrotropin-releasing hormone and norepinephrine potentiation of inspiratory-related hypoglossal motoneuron discharge in neonatal and juvenile mice in vitro.

1. The ontogeny of thyrotropin-releasing hormone (TRH) and norepinephrine (NE) potentiation of inspiratory-related hypoglossal (XII) motor nerve discharge was studied in medullary slices from P0-3, P7, and P11-14 mice that retain functional networks for respiration. 2.

Acute airway compromise secondary to traumatic thyroid hemorrhage.

Hemorrhage into cystic thyroid nodules is a relatively frequent event. Most cases are mild, causing only pain and discomfort, and rarely cause significant neck swelling. Even more rarely, however, massive hemorrhage into a thyroid nodule can result in a rapidly expanding hematoma with airway compromise.

Motion observed across maxillary continuity defects stabilized with plates and screws.

The stability of fixation obtained with internal fixation devices (plates and screws) under functional loading of maxillary continuity defects was studied using fresh cadaver skulls. Micromotion (deformation) was recorded in the model across the level of the LeFort I osteotomies even when fixation was thought to be grossly stable. Deformation in this biologically static model proved to be mostly elastic in nature, and the amount of deformation in each skull appeared to be predictable from the average stability of all screws used in each plate.

Generation and transmission of respiratory oscillations in medullary slices: role of excitatory amino acids.

1. The involvement of excitatory amino acid (EAA) receptors in the generation of respiratory rhythm and transmission of inspiratory drive to hypoglossal (XII) motoneurons was examined in an in vitro neonatal rat medullary slice preparation. Slices generated rhythmic inspiratory activity in XII nerves.

Osseointegrated implants: a comparative study of bone thickness in four vascularized bone flaps.

Primary and secondary reconstruction of mandibular continuity defects with vascularized bone is currently the standard of care at many institutions. The most commonly utilized donor sites for such bone flaps include the scapula, iliac crest, fibula, and radius. Recently, interest has grown in the placement of osseointegrated implants into these flaps to facilitate functional dental rehabilitation.

Special considerations in the management of malignant skin lesions about the eye.

The periocular midface is a complex anatomic region in which the spread of cutaneous malignancies is determined not only by the tumor pathology but also by adjacent natural anatomic barriers. The resulting management considerations when treating malignancies in this region are discussed in this article.

Dietary polyunsaturated to saturated fatty acid ratio alters hepatic LDL transport in cynomolgus macaques fed low cholesterol diets.

To determine effect of interaction between dietary cholesterol and triglyceride, i.e., polyunsaturated to saturated (P:S) fatty acid ratio, on LDL metabolism, male cynomolgus macaques were fed purified diets for 83 wk with cholesterol levels of 0.

Coordination of wingbeat and respiration in birds. II. "Fictive" flight.

To determine whether an interaction between central respiratory and locomotor networks may be involved in the observed coordination of wingbeat and respiratory rhythms during free flight in birds, we examined the relationship between wingbeat and respiratory activity in decerebrate Canada geese and Pekin ducks before and after paralysis. Locomotor activity was induced through electrical stimulation of brain stem locomotor regions. Respiratory frequency (fv) was monitored via pneumotachography and intercostal electromyogram recordings before paralysis and via intercostal and cranial nerve IX electroneurogram recordings after paralysis.