Analgesic effects of posthypnotic suggestions and virtual reality distraction on thermal pain.

The individual and combined effects of posthypnotic suggestion (PHS) and virtual reality distraction (VRD) on experimentally induced thermal pain were examined using a 2 x 2, between-groups design. After receiving baseline thermal pain, each participant received hypnosis or no hypnosis, followed by VRD or no VRD during another pain stimulus. Consistent with the hypothesis that hypnosis and VRD work via different mechanisms, results show that posthypnotic analgesia was moderated by hypnotizability but VRD analgesia was not. The impact of PHSs for analgesia was specific to high hypnotizables, whereas VRD was effective independent of hypnotizability. Results also show a nonsignificant but predicted pattern for high hypnotizables: Audio hypnosis combined with VRD reduced worst pain 22% more and pain unpleasantness 25% more than did VRD alone. Theoretical and clinical implications are discussed.

Rapid heating of a strongly coupled plasma near the solid-liquid phase transition.

Between 10(4) and 10(6) 9Be+ ions were trapped in a Penning trap and laser cooled to approximately 1 mK, where they formed a crystalline plasma. We measured the ion temperature as a function of time after turning off the laser cooling and observed a rapid temperature increase as the plasma underwent the solid-liquid phase transition at T approximately 10 mK (Gamma approximately 170). We present evidence that this rapid heating is due to a sudden release of energy from weakly cooled degrees of freedom involving the cyclotron motion of trapped impurity ions. This equilibration of cyclotron motion with motion parallel to the magnetic field is more than 10 orders of magnitude faster than that predicted by currently available theory, which is valid only in the absence of correlations (Gamma<<1).

Expression, purification, and efficacy of the type A botulinum neurotoxin catalytic domain fused to two translocation domain variants.

Clostridial neurotoxins are potent inhibitors of synaptic function, with the zinc-dependent proteolytic light chain (LC) portion of the toxin cleaving one of three neural SNARE proteins. In nature, the LC is expressed as a part of a much larger toxin and hemagglutinin complex, protecting it from environmental degradation and preserving its catalytic activity. We developed forms of the LC of type A botulinum neurotoxin (BoNT-A) with parts of the larger toxin gene, for use as reagents in high-throughput assays to screen for potential LC antagonists, to further elucidate the toxin's mechanism of action, and to study immunological responses to the toxin. Three BoNT-A constructs were engineered and expressed: the LC, LC with translocation region (LC+H(n)), and the LC with the belt portion of the translocation region (LC+Belt). Purification was optimized to a two-step process, with relatively high yields of all three constructs obtained. Activity assays showed all three constructs to be active, with the LC being the most active. Immunogenic protection against native BoNT-A toxin challenge was observed for all three constructs, with the best protection observed with the LC+H(n) and LC+Belt proteins.

Ludwig's angina: report of a case and review of management issues.

Ludwig's angina, although uncommon, remains a potentially life-threatening condition because of the risk of impending airway obstruction. Effective treatment is based on early recognition of the clinical process, with the appropriate use of parenteral antibiotics, airway protection techniques, and formal surgical drainage of the infection. We present a case of Ludwig's angina together with a brief review of the relevant literature.

Cyclin D1 and p16INK4A expression predict reduced survival in carcinoma of the anterior tongue.

Cyclin D1 and p16INK4A are molecules with pivotal roles in cell cycle control and the development of diverse human cancers, and overexpression of cyclin D1 and loss of p16INK4A expression are common genetic events in head and neck squamous cell carcinoma. The prognostic significance of these molecular events at different sites within the head and neck, however, remains controversial. Thus, we sought to determine the relationship between cyclin D1 and/or p16INK4A expression and disease outcome in squamous cell carcinoma of the anterior tongue. Immunohistochemical detection of nuclear proteins cyclin D1, p53, and p16INK4A, and the Ki-67 labeling index was undertaken in tissue sections from 148 tongue cancers treated by surgical resection. Nuclear antigen status was analyzed in relation to pathological variables, tumor recurrence, and patient survival. Statistical significance was assessed using chi2 analysis for pathological variables and the Kaplan-Meier method, log rank test, and the Cox proportional hazards model for survival parameters. Overexpression of cyclin D1 occurred in 68% of tumors (100 of 147) and was associated with increased lymph node stage (P = 0.014), increased tumor grade (P = 0.003), and reduced disease-free (P = 0.006) and overall (P = 0.01) survival. Loss of p16INK4A expression was demonstrated in 55% of tumors (78 of 143) and was associated with reduced disease-free (P = 0.007) and overall (P = 0.014) survival. Multivariate analysis confirmed that in addition to pathological stage and regional lymph node status, cyclin D1 overexpression and loss of p16INK4A expression are independent predictors of death from tongue cancer. Loss of p16INK4A in the presence of cyclin D1 overexpression conferred a significantly worse disease-free (P = 0.011) and overall (P = 0.002) survival at 5 years. p53 nuclear accumulation and the Ki-67 labeling index were not prognostic. These data indicate that cyclin D1 overexpression and loss of p16INK4A expression predict early relapse and reduced survival in squamous cell carcinoma of the anterior tongue. Simultaneous assessment of cyclin D1 and p16INK4A protein levels define subgroups of patients at increased risk of relapse and may be of clinical utility in optimizing therapy.

A model for the membrane topology of the NS3 protein as predicted from the sequence of segment 10 of epizootic haemorrhagic disease virus serotype 1.

Segment 10, encoding nonstructural proteins 3 (NS3) and 3a (NS3a) of epizootic haemorrhagic disease virus serotype 1 (EHDV-1) was sequenced. Computer motif recognition programs were used for interpretation of the sequence data to predict a structure for NS3. Integral membrane protein theories were then applied to produce a general topological model for the EHDV-1 NS3 protein. Homology was observed between EHDV-1 NS3 integral membrane motifs and those similarly observed in the cognate proteins of other orbiviruses.

The smallest gene of the orbivirus, epizootic hemorrhagic disease, is expressed in virus-infected cells as two proteins and the expression differs from that of the cognate gene of bluetongue virus.

The smallest gene (S10) of the virus of epizootic hemorrhagic disease of deer (EHD, serotype 2) is expressed as two proteins in virus-infected cells. By contrast, the non-structural proteins (NS3 and NS3A) encoded in the smallest gene of bluetongue (BT) viruses are difficult to detect in virus-infected cells. The nucleotide sequence of S10 of EHDV-2 contains two in-frame initiation codons which allow for translation of proteins of mol. wt. 25503 and 23921 analogous to NS3 and NS3A of BT viruses. The S10 genes of BT viruses are highly conserved (82%-99%); the nucleotide sequence similarity of S10 of EHDV-2 and BT viruses is about 64%. Some structural features of NS3 and NS3A are conserved in the two viruses, despite the divergence in the amino acid sequences of the proteins. The hydrophobic domains of the proteins and the putative transmembrane sequences are conserved, as are potential glycosylation sites in the proteins. A cluster of proline residues, which is conserved at residues 36-50 in all of the published sequences of NS3 of BT viruses, is conserved exactly in the alignment of the sequence of NS3 of EHDV-2 with that of the BT viruses. An explanation for the differences in expression of NS3/NS3A in EHD and BT viruses was not evident in comparing the nucleotide sequences of S10 of the viruses.

Phenotypic and functional characterization of mouse attenuated and virulent variants of foot-and-mouth disease virus type O1 Campos.

A series of genetically related variants arising from a parental wild-type isolate of O1 Campos and its tissue culture adapted variant were differentiated by various cell culture markers (temperature sensitivity, plaque size, viral yield) and lethality in mice. These isolates were additionally characterized functionally and biochemically by examining poly(C) length, RNA synthesis, protein synthesis, and cell receptor binding. In primary bovine kidney cells, the virulent isolates had greater levels of protein synthesis, whereas in baby hamster kidney cells, the attenuated variant outproduced the wild-type parent. The tissue culture adapted variant had substantially greater ability to attach to cells than the parental wild type. The parental wild-type and the tissue culture-adapted variant were similarly neutralized by various sera against whole virus, but the parental wild type was less effectively neutralized by sera prepared from either full or truncated (variable region) bacterially expressed VP1 polypeptides. The capsid region of the genomes of both these variants was sequenced and a nucleotide substitution resulting in a change in amino acid 56 in VP3 was found. The nucleotide sequence change for the remaining two variants was that of the parental wild-type virus.

Surgical treatment of tumours of the skull base.

OBJECTIVE: To describe the special features of surgical removal of tumours of the skull base and to review a series of patients treated for skull base tumours. DESIGN: A retrospective review of patients followed up for between six months and six years. SETTING: A unit specialising in surgery of the skull base at a tertiary referral centre. PATIENTS: Sixty-six patients with skull base tumours were referred to the unit between February 1984 and December 1989. INTERVENTIONS: Fifty-six of the patients underwent complete or partial surgical removal of the tumour. Radiotherapy was used as primary treatment in 10 patients, for tumour recurrence in four patients and as adjuvant postoperative treatment in 10 patients. RESULTS: In the majority of patients the tumours were benign and have been controlled or are considered cured. Of the seven patients with malignant tumours five have died and two are long-term survivors (one has multiple metastases). Three patients with histologically "benign" tumours died of multiple metastases. There have been a total of 10 deaths in the series but only one occurred in the perioperative period. Cranial nerve palsy was the major postoperative complication. CONCLUSION: Modern microsurgical techniques and modern anaesthesia and intensive care skills lead to a cure in many patients with skull base tumours previously considered inoperable.

Venous drainage of free flaps following radical neck dissection.

Large tissue defects may occur following head and neck surgery. When combined with ipsilateral radical neck dissection the venous drainage of a free flap used to cover the defect may be compromised. Twelve patients having radical neck dissections underwent on-table venography to study the pattern of venous drainage of these flaps. The predominant drainage pattern is initially in a cephalic direction, then across the midline and finally in a caudal direction on the contralateral side of the neck. Venous drainage to the contralateral side of the neck may be a determinant of flap survival. In order to facilitate venous drainage following free flap procedures, patients should be positioned so that the contralateral internal jugular vein is not compressed. Drains should be placed caudal to the microvascular anastomoses in order to minimize interference with the cephalic direction of venous drainage. Any patient having a radical neck dissection requiring a central venous catheter should have it placed ipsilateral to the neck dissection. Thrombosis around a contralaterally placed cannula may significantly increase head and neck venous pressure.

A comparative study of the Seiko P-3 and Varilux 2 progressive addition lenses.

Forty patients were selected to participate in a double-masked comparative study of the Seiko Plax 3 (P-3) and Varilux 2 progressive addition lenses. The study was designed to determine patient preference for either lens design. The patients wore each lens for 1 month. Following each period, a questionnaire relating to the patient's impressions of the lenses was completed. After both wearing periods, the patient's preference was determined. The results show that 89.7% of the patients preferred the Seiko lens over the Varilux. Further, 82.4% chose the Seiko lens and 44.1% chose the Varilux lens over their habitual multifocal design. The results of this study show that, in addition to a preference for the Seiko P-3 design, both progressive addition lenses are viable alternatives to the conventional multifocal lens.

A clinical study of the use of musculocutaneous island flaps for reconstruction in head and neck surgery.

Eleven cases of the musculocutaneous island flap (MCIF) and their use in major reconstructions for head and neck surgery are described. Methods used in investigating the blood supply of these flaps in cadaver specimens are discussed as well as the use of radionuclear scanning of the blood supply of the flaps in postoperative patients.

Intussusception in the adult.

Intussusception in the adult is an uncommon cause of intestinal obstruction. Seventeen cases were seen at two teaching hospitals over a twenty-year period. A local causative lesion was present in all cases; a malignant tumour was present in two out of seven intussusceptions arising in the small intestine and in seven out of ten arising in the large intestine. More than half the cases had a protracted clinical course prior to diagnosis.

Radical resection for osteogenic sarcoma of fibula with preservation of the limb.

This is a report of a 15 year old girl with osteogenic sarcoma of the proximal fibula treated by en bloc radical excision without amputation of the limb. The anatomical individuality of the fibula, vascularization of the leg and effective adjuvant chemotherapy determined the feasibility of the procedure. There is no evidence of tumor recurrence 27 months after surgery.