Re-innervation of facial nerve territory using a composite hypoglossal nerve--muscle autograft--facial nerve bridge. An experimental model in sheep

The hypoglossal nerve has been used both entirely and in part to repair the facial nerve. Using the partial technique it may be difficult to obtain sufficient length and a free interposed graft is then required to extend the hypoglossal element. In six sheep the facial nerve was excised between its emergence from the stylomastoid foramen and its bifurcation in the parotid gland. The hypoglossal nerve was exposed and split longitudinally producing a limb which was reflected towards the distal stump of the facial nerve. This left a gap of 4-5 cm which was bridged with a freeze-thawed coaxially aligned skeletal muscle autograft. The sheep were examined at 8 months. Laser doppler blood-flow studies showed the blood-flow distal to the graft to be about 25% of that at an equivalent site on the normal side. Peak nerve conduction velocities were also reduced on the repaired side but stimulation of the proximal hypoglossal nerve was nevertheless capable of causing adequate contraction of both facial and tongue muscles. Histological comparison of the repaired facial nerves with equivalent sites on the normal side showed a reduction in mean axon and fibre diameters with normal myelin sheath thickness for the regenerated axon sizes. All of these features are to be expected in a regenerated nerve and are consistent with a good level of recovery of function.

A family of cyclin D homologs from plants differentially controlled by growth regulators and containing the conserved retinoblastoma protein interaction motif

A new family of three related cyclins has been identified in Arabidopsis by complementation of a yeast strain deficient in G1 cyclins. Individual members show tissue-specific expression and are conserved in other plant species. They form a distinctive group of plant cyclins, which we named delta-type cyclins to indicate their similarities with mammalian D-type cyclins. The sequence relationships between delta and D cyclins include the N-terminal sequence LXCXE. This motif was originally identified in certain viral oncoproteins and is strongly implicated in binding to the retinoblastoma protein pRb. By analogy to mammalian cyclin D, these plant homologs may mediate growth and phytohormonal signals into the plant cell cycle. In support of this hypothesis, we show that, on restimulation of suspension-cultured cells, cyclin delta 3 is rapidly induced by the plant growth regulator cytokinin and cyclin delta 2 is induced by carbon source.

Vasoactive intestinal contractor: localization in the opossum esophagus and effects on motor functions

BACKGROUND/AIMS

Vasoactive intestinal contractor (VIC), an endothelinlike peptide and a putative gastrointestinal hormone, contracts gastrointestinal smooth muscle. The aim was to study VIC in relation to esophageal function.

METHODS

Intramural nerves in opossum esophageal smooth muscle strips were stimulated in the presence of various concentrations of VIC and were stained for VIC immunoreactivity.

RESULTS

VIC caused an atropine-resistant increase in the amplitude of nerve-induced contractions of the circular muscle. VIC alone contracted longitudinal muscle, and this effect was nearly eliminated by 1 mmol/L atropine. VIC caused an atropine-resistant increase in the resting tone of the lower esophageal sphincter muscle, but it did not affect nerve-induced relaxation of that muscle. VIC-immunoreactive nerve fibers occurred in the longitudinal muscle layer, in the muscularis mucosae, and around the ducts of esophageal glands. A few such fibers were found in the circular muscle layer. Nerve fibers and cell bodies of the myenteric plexus showed VIC immunoreactivity. In the stomach, immunoreactive nerve fibers occurred in muscularis mucosae and circular muscle but not in longitudinal muscle.

CONCLUSIONS

VIC is localized in neuronal elements of the opossum esophagus and excites contractions in esophageal smooth muscle.

The effect of fibrin sealant haemostasis on post-operative pain in tonsillectomy

Pain following tonsillectomy is an important problem. It is caused by the surgical trauma of excision and haemostasis. Numerous surgical and pharmacological solutions have been tried, with disappointing results. Fibrin sealant is a widely used atraumatic haemostatic agent. This study aims to determine whether tonsillectomy with fibrin sealant haemostasis results in less post-operative pain than that with the conventional technique of diathermy. Fifty consecutive adult patients undergoing tonsillectomy were prospectively studied. They were randomized to receive either fibrin sealant or diathermy haemostasis. Other pain variables were controlled. Pain was measured by a visual linear analogue scale and inter-incisor distance on both the day of operation and the first post-operative day. The patients and pain measurer were blind to the randomization. The results showed that tonsillectomy with fibrin sealant haemostasis was significantly (P < 0.05) less painful than that with diathermy on both days studied and by both methods of pain measurement.

Roles of Triton X-100 in NADPH-diaphorase histochemistry

Triton X-100 is widely but not universally used in NADPH-diaphorase histochemical staining. We investigated its effect on the staining and examined nitroblue diformazan (NBF) production under the influence of Triton X-100. Exposure of opossum esophagus, intestine, and colon tissues to Triton X-100 before staining enhanced staining of nerve cells and fibers and suppressed staining of non-neural structures. Long exposures and high concentrations nearly abolished the staining of non-neural structures and decreased the staining of nerves. The use of an incubation medium containing Triton X-100 achieved the best staining of nerve cells and fibers. Addition of Triton X-100 to the incubation medium changed its color from yellow to purple; in the presence of tissues, this color change occurred much more quickly. Spectral analysis showed that Triton X-100 increases the rate of NBF formation in the presence of tissue supernatant. Triton X-100 increases it less in the absence of tissue supernatant. Therefore, Triton X-100 improves the histochemical staining, probably by catalyzing the activity of NADPH-diaphorase, by keeping the extracellular NBF in solution and thus suppressing the staining of non-neural structures, and by increasing the permeability of cell membranes.

The Edinburgh facial palsy clinic: a review of three years' activity

Patients with facial palsy can present to almost all medical practitioners. From birth to old age the aetiologies of disease affecting the nerve range from congenital to the more common inflammatory, infective, traumatic and neoplastic. This paper reviews the Edinburgh Facial Palsy Clinic, its structure and function over a three year period. The methods of clinical investigation, special investigation and management strategies are discussed. The diversity of pathology seen over a three year period is presented, confirming the need for a team approach to the management of patients with facial palsy.

Acute and chronic diarrhea. How to keep laboratory testing to a minimum

Diagnosing a cause of diarrhea is a challenging undertaking but can be accomplished if a systematic approach is used for evaluation. Pathophysiologic mechanisms of acute diarrhea (eg, Giardia lamblia infection, antibiotic use) are different from those of chronic diarrhea (eg, secretory dysfunction from thyrotoxicosis, lactose or fructose intolerance), so adequate history taking and physical examination are essential in narrowing the diagnosis. Laboratory investigation can then be directed using the information obtained, and the cause of the diarrhea can be established without subjecting the patient to extensive and expensive testing. Undoubtedly, some functional entities that contribute to diarrhea await discovery.

Comparison of charges related to radiotherapy for soft-tissue sarcomas treated by preoperative external-beam irradiation versus interstitial implantation

BACKGROUND

We compared treatment-related charges associated with external beam irradiation and interstitial implantation for soft-tissue sarcoma of the extremity.

METHODS

Charges related to radiotherapy in 35 patients with soft-tissue sarcoma of the extremity were reviewed. Preoperative external beam irradiation (EB) delivering 50 Gy in 25 fractions with 6 MV photons was administered to 12 of the patients evaluated. The remaining 23 patients were treated with interstitial implantation (IR) as the only radiotherapeutic intervention. The anatomic distribution of the sarcomas treated by IR included 14 lower-extremity (LE) and nine upper-extremity (UE) lesions. The average length of iridium wire used for IR was 78 cm. Because LE lesions tend to be larger, the average length equaled 109.5 cm as compared with the 47 cm for UE implants.

RESULTS

The radiotherapeutic approach represented the only difference in treatment-related charges because the operative procedure of wide local excision was performed in each group. No difference in perioperative complications was observed between the two treatment approaches. Charges were stratified according to hospital-based and professional services. Radiotherapy-based hospital charges for the administration of EB averaged $6,515 compared with $4,050 for IR (p < 0.0001). Professional services also were significantly different, totaling $4,390 for EB and $3,240 for IR (p < 0.0001). The total of these charges for radiotherapy procedures and professional fees equaled $10,905 for EB compared with $7,290 for IR (p < 0.0001). Incorporating the necessary operating-room time for implant placement ($750) and five additional hospital days ($1,800), the costs associated with IR totaled $9,840; using chi-square analysis, the cost for IR remained significantly (p < 0.0001) less expensive than the $10,905 associated with EB. Because a large component of the radiotherapy cost for IR is related to the length of iridium 192 wire required, charges were stratified according to the location of the tumor. The total charge for IR of the UE equaled $9,345 compared with $10,335 for LE implants. Chi-square comparison for both UE and LE implants continued to show significant differences (p < 0.0001) when related to EB therapy.

CONCLUSION

Cost-analysis comparison of brachytherapy versus external beam irradiation found lower charges for patients undergoing adjuvant irradiation with brachytherapy for soft-tissue sarcoma. To optimize the cost-benefit ratio, prospective studies are necessary to define the application of these radiotherapeutic approaches based on clinical criteria.

Minimal cross-sectional areas, nasal peak flow and patients' satisfaction in septoplasty and inferior turbinectomy

Changes in minimal cross-sectional areas, measured by acoustic rhinometry as well as nasal peak flow fractions and linear analogue patients' satisfaction scores, were measured in two groups of eight patients each, undergoing septoplasty alone and septoplasty combined with trimming of the inferior turbinates, respectively. Patients who had both procedures performed showed the greatest increase in both minimal cross-sectional areas and peak flow fractions, and both of these parameters were closely correlated with patients' satisfaction, whether the patient was satisfied or not. Pre-operative nasal obstruction was worse in the dual-procedure group, but post-operative satisfaction was significantly greater in these patients. Both acoustic rhinometry and nasal peak flow fractions can be recommended as accurate and easy to perform pre-operative measurements in patients undergoing surgery for nasal obstruction.

The prognostic value of facial electroneurography in Bell's palsy

Twenty six patients with Bell's palsy were studied at presentation using electroneurography. Ninety-four per cent of those who recovered completely could have been predicted by ENoG within 10 days of onset. Of the 18 patients who recovered completely, 13 had a total palsy at presentation.

An out-patient review of facial palsy in the community

The true psychological morbidity of facial palsy, including Bell's palsy, is not fully understood. This study addresses this problem by a voluntary questionnaire of ENT out-patients. It is not a representative study but indicates that the long-term sequelae of facial palsy is under-estimated by clinicians.

A comparison of glue and a tube as an anastomotic agent to repair the divided buccal branch of the rat facial nerve

The best anastomotic agent to join nerve ends is controversial. This paper describes a controlled trial between a collagen tube wrap and a tissue glue to anastomose the rat facial nerve. There was no difference in the results using photographic, histological and electrophysiological techniques.

Characterization of nitric oxide synthase in the opossum esophagus

BACKGROUND/AIMS

Nitric oxide mediates the nonadrenergic, noncholinergic neural control of esophageal motor function. The purpose of this study was to characterize the NO synthase found in the muscularis propria of the opossum esophagus and determine its distribution along the esophagus.

METHODS

Esophageal muscle was homogenized in HEPES buffer and ultracentrifuged. The supernatant was exposed to [3H]L-arginine. The [3H]L-citrulline produced by NO synthase was separated from [3H]L-arginine with a Dowex AG 50 W-X8 column (Biorad, Hercules, CA). Assays were performed in the presence and absence of Ca2+ or reduced nicotinamide adenine dinucleotide phosphate (NADPH). The distribution of NO synthase activity along the esophagus was determined.

RESULTS

The apparent Michaelis constant and maximum velocity of NO synthase were 7.5 +/- 1.4 mumol/L L-arginine and 76.0 +/- 17.3 pmol.mg protein-1.min-1, respectively. The enzyme required both Ca2+ and NADPH for activity. Smooth muscle tissue from the lower esophageal sphincter and the esophageal body 1-2 cm or 5-6 cm above the lower esophageal sphincter differed little in enzymatic activity, ranging from 0.97 to 1.27 pmol.mg wet wt-1.min-1. Striated muscle had less activity with 0.40 pmol.mg wet wt-1.min-1.

CONCLUSIONS

These data indicate the presence of a constitutive NO synthase in the esophagus of the opossum.

A comparison of epineurial and perineurial sutures for the repair of a divided rat sciatic nerve

Whether epineurial or perineurial nerve repair is superior remains debatable. This paper describes a controlled trial comparing these suture techniques. Both have identical results.

Frequency as a releaser in the courtship song of two crickets, Gryllus bimaculatus (de Geer) and Teleogryllus oceanicus: a neuroethological analysis

1. The courtship behavior of male field crickets, Gryllus bimaculatus (De Geer) and Teleogryllus oceanicus, is a complex, multimodal behavioral act that involves acoustic signals (a courtship song; Fig. 1A, B). The dominant frequency is 4.5 kHz for T. oceanicus song (Fig. 1A) and 13.5 kHz for G. bimaculatus (Fig. 1B). 2. When courting males are deprived of their courtship song by wing amputation, their courtship success declines markedly but is restored when courting is accompanied by tape-recordings of their courtship songs or a synthetic courtship song with only the dominant frequency of the natural song; other naturally occurring frequency components are ineffective for restoring mating success (Figs. 4, 5). 3. It has been suggested that an identified auditory interneuron, AN2, plays a critical role in courtship success. Chronic recordings of AN2 in an intact, tethered female show that AN2's response to the natural courtship song and synthesized songs at 4.5 and 13.5 kHz is similar in T. oceanicus. By contrast, in G. bimaculatus, AN2's response to the natural courtship song and synthesized song at 13.5 kHz, but not at 4.5 kHz, is similar (Fig. 2,3). 4. In behavioral experiments, playback of a 30 kHz synthetic courtship song in G. bimaculatus does not restore courtship success, yet this same stimulus elicits as strong a response from AN2 as does the normal courtship song (Fig. 6). Thus, contrary to earlier work by others, we conclude AN2 is not, by itself, a critical neural link in the courtship behavior of these two species of crickets.

A comparison of absorbable and non-absorbable 10-0 sutures for the repair of a divided rat facial nerve

The use of absorbable sutures to anastomose nerves is controversial. This paper reports on a controlled trial comparing absorbable and non-absorbable sutures for this purpose. No difference between the sutures was found.

Giant solitary synovial chondromatosis

The purpose of this report is to describe giant solitary synovial chondromatosis, a previously unrecognized feature of synovial chondromatosis that may histologically and radiographically mimic a malignant neoplasm. Giant solitary synovial chondroma is an intra- and/or extraarticular lesion measuring over 1 cm in size and sometimes as large as 20 cm. The radiographic appearance is that of a large, well-marginated mass either of irregular feathery calcification from coalescence of multiple small synovial chondromas, or a rounded calcified mass from the growth of a single synovial chondroma. Radiographically, giant solitary synovial chondromatosis may appear similar to chondrosarcoma and parosteal osteosarcoma.