Plasma osteopontin velocity differentiates lung cancers from controls in a CT screening population

INTRODUCTION

As CT screening is integrated into non-small cell lung cancer (NSCLC) care, additional parameters are needed to help distinguish cancers from benign nodules. Osteopontin (OPN), a secreted phosphoprotein, has elevated plasma levels in NSCLC. We hypothesize that changes in plasma OPN over time (i.e., OPN velocity [OPNV]) can differentiate NSCLC patients from those without cancer in a CT screening population.

METHODS

A nested case-control study was conducted within a NSCLC CT screening trial. Incident cancers with serial plasma were matched to controls. OPN was measured by ELISA. Demographic, OPN, and OPNV were compared between cancers and controls using Wilcoxon Signed Rank tests.

RESULTS

Ten incident cancers were identified. The pack years distributions were similar, but cancers were older (median of the paired difference: 5.35 years; p=0.002) and their surveillance intervals were shorter (median of the paired difference: -2 months; p=0. 03) than matched controls. Baseline OPN was similar (median of the paired difference: -5.15 ng/ml, p=0.50), but OPNV in the cancers was significantly greater than that of matched controls, (median of the paired difference: 1.06 ng/ml/month, p=0.01). Accuracy rate for prediction of disease status based on OPNV (adjusted for age and surveillance) was 83%.

CONCLUSIONS

These are early evidence for utility of monitoring plasma OPN during CT screening to assist in identification of NSCLCs.

Abstract 3444: Exon 4 of osteopontin: A unique target to reduce malignant behavior in non-small cell lung cancer

INTRODUCTION: Osteopontin (OPN) is a ubiquitous protein associated with a wide range of normal and pathologic functions. It is a central regulator of malignant phenotype in non-small cell lung cancer (NSCLC). OPNa, the full length isoform, is disproportionately expressed in NSCLC tumors and cell lines, and increases malignant behavior when over expressed. OPNc, the shortest isoform, does not induce malignant properties when expressed in NSCLC. The only structural difference between OPNa and OPNc is the transcription of exon 4. The hypothesis of this project is that a small interfering peptide to OPN exon 4 will reduce in vitro malignant activity in NSCLC. METHODS: A 16-amino acid peptide which mimics the central sequence in OPN exon 4 and a scrambled sham were constructed and florescent labeled. Three NSCLC cell lines, H358 (low), A549 (moderate), and H460 (high endogenous OPN) were used in binding, proliferation, and invasion assays in presence of exon 4 mimic or sham. Cisplatin sensitivity was performed with peptides in A549. RESULTS: There was florescent evidence for cell surface binding of the exon 4 mimic in all of the NSCLC cell lines without binding of the sham. The exon 4 mimic significantly decreased in vitro invasion and proliferation in the A549 and H460 cell lines, with a lesser effect in H358 with low endogenous OPN. (Table) The exon 4 mimic increased cisplatin sensitivity, decreasing cell viability 2-fold compared to sham and control at cisplatin concentrations 0.1-0.8 uM/ml. CONCLUSIONS: Exon 4 of OPN has not previously been identified as a regulatory region essential for OPN's effect on malignant behavior. We have evidence for an un-described cell surface receptor to this region. A small mimicking peptide to OPN exon 4 significantly decreased in vitro malignant behavior, suggesting interference with important regulatory pathways. This novel binding site could serve as an ideal for target for antibody or small molecule therapies in NSCLC.

Nicotine and estrogen synergistically exacerbate cerebral ischemic injury

The greater incidence of myocardial infarction, cardiac arrest, and ischemic stroke among women who smoke and use oral contraception (OC) compared to women who do not smoke and who do or do not use OC may be due in part to how nicotine influences endocrine function in women. For example, we recently demonstrated that chronic exposure to nicotine, the addictive agent in tobacco smoke responsible for the elevated risk of cardiac arrest, abolishes the endogenous or exogenous 17β-estradiol-conferred protection of the hippocampus against global cerebral ischemia (a potential outcome of cardiac arrest) in naive or ovariectomized female rats. In the current study we examined the hypotheses that (1) a synergistic deleterious effect of nicotine plus oral contraceptives exacerbates post-ischemic hippocampal damage in female rats, and (2) nicotine directly inhibits estrogen-mediated intracellular signaling in the hippocampus. To test first hypothesis and to simulate smoking behavior-induced nicotine levels in the human body, we implanted osmotic pumps containing nicotine in the female rats for 16 days. Furthermore, we mimicked the use of oral contraceptives in females by administering oral contraceptives orally to the rat. Rats exposed to either nicotine alone or in combination with oral contraceptives were subjected to an episode of cerebral ischemia and the resultant brain damage was quantified. These results showed for the first time that nicotine with oral contraceptives did indeed exacerbate post-ischemic CA1 damage as compared to nicotine alone in naive female rats. In ex vivo hippocampal slice cultures, we found that nicotine alone or with 17β-estradiol directly hinders estrogen receptors-mediated phosphorylation of cyclic-AMP element binding protein, a process required for neuronal survival and also exacerbates ischemic damage. Thus, nicotine can affect the outcome of cerebral ischemia by influencing brain endocrine function directly rather than through indirect systemic effects.

Abstract 3193: EPHB2 expression parallels malignant behavior in mesothelioma

Purpose: Erythropoietin-producing hepatocellular (EPH) receptors and their Ephrin (EFN) ligands are members of the transmembrane receptor tyrosine kinase (RTK) family. EPHB2 is a RTK, promotes uncontrolled cell growth, migration and tumor progression. Preliminary gene array data indicate EPHB2 overexpression in malignant pleural mesothelioma (MPM). Here, we aim to verify EPHB2 overexpression in MPM tumors and cell lines and hypothesize that EPHB2 silencing decreases malignant behavior in MPM cell lines.

Methods: EPHB2 mRNA expression was evaluated by RT-PCR in eight MPM and three benign mesothelial cell lines, and seven pairs of MPM tumors and matched normal tissue. Functional significance of EPHB2 was evaluated by transfecting EPHB2-shRNA and empty vector controls into two MPM cell lines, HP-1 and H2595. Expression of EPHB2, BCL2L1, survivin, Caspase2, Caspase8, matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) were evaluated by RT-PCR following silencing. Pooled populations of transfected cells were evaluated in scratch closure, cell proliferation by CellTitre BlueTM, MatrigelTM Invasion and colorimetric TUNELTM apoptotic assays. Comparisons were made between EPHB2 silenced and control cell lines.

Results: EPHB2 was overexpressed in all MPM cell lines, but not in the benign mesothelial cell lines and in all tumors compared to matched normal tissue. Targeted knockdown of EPHB2 in MPM cell lines reduced its expression and subsequently reduced MMP-2, VEGF, BCL2L1 and survivin expression, and increased Caspase2 and Caspase8 expression. Inhibition of EPHB2 significantly decreased scratch closure, proliferation and invasion compared to the controls, and significantly increased apoptotic cells, likely related to Caspase2 and Caspase8 mediated cell death.

Conclusion: Silencing of EPHB2 reduced the malignant behavior in MPM cell lines. EPHB2 appears to play an important role in MPM pathogenesis and could potentially serve as a novel therapeutic target for MPM treatment.Results of Functional AssaysAssayHP-1 ControlHP-1 EPHB2shRNAp ValueH2595 ControlH2595 EPHB2shRNAp ValueScratch Assay (% closure)69.237.6<0.00556.945.7<0.03Cell Proliferation Assay (OD value)9.56.4<0.058.75.7<0.05Matrigel Invasion Assay (cells invaded)14678<0.0057643<0.005TUNEL Apoptotic Assay (% apoptotic cells)074n/a088.5n/a       

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3193.

Lymphocyte contamination of laryngoscope blades - a possible vector for transmission of variant Creutzfeldt-Jakob disease

Variant Creutzfeldt-Jakob disease (vCJD) is associated with extensive prion infection of lymphoreticular tissues during the prolonged asymptomatic incubation period. Instruments exposed to infected tissues of preclinically infected individuals during medical or surgical procedures represent a potential risk of iatrogenic transmission of vCJD prions. We assessed the frequency of contamination with lymphoid tissue of single-use laryngoscope blades used for tracheal intubation for general anaesthesia. Using a cyto-centrifugation technique, lymphocytes were detected from 30% of laryngoscope blades studied. As prions resist routine sterilisation procedures, the use of non-disposable laryngoscope blades poses a risk of transmitting vCJD from patient to patient. The use of such instruments should be abandoned and disposable alternatives used.

Outcome of ventilatory support for acute respiratory failure in motor neurone disease

OBJECTIVES

To review the outcome of acute ventilatory support in patients presenting acutely with respiratory failure, either with an established diagnosis of motor neurone disease (MND) or with a clinical event where the diagnosis of MND has not yet been established.

METHODS

Outcome was reviewed in 24 patients with respiratory failure due to MND who received endotracheal intubation and intermittent positive pressure ventilation either at presentation or as a result of the unexpected development of respiratory failure. Patients presenting to local hospitals with acute respiratory insufficiency and requiring tracheal intubation, ventilatory support, and admission to an intensive therapy unit (ITU) before transfer to a regional respiratory care unit were selected. Clinical features of presentation, management, and outcome were studied.

RESULTS

24 patients with MND were identified, all being intubated and ventilated acutely within hours of presentation. 17 patients (71%) were admitted in respiratory failure before the diagnosis of MND had been made; the remaining seven patients (29%) were already known to have MND but deteriorated rapidly such that intubation and ventilation were initiated acutely. Seven patients (29%) died on ITU (between seven and 54 days after admission). 17 patients (71%) were discharged from ITU. 16 patients (67%) received long term respiratory support and one patient required no respiratory support following tracheal extubation. The daily duration of support that was required increased gradually with time.

CONCLUSION

When a patient with MND is ventilated acutely, with or without an established diagnosis, independence from the ventilator is rarely achieved. Almost all of these patients need long term ventilatory support and the degree of respiratory support increases with time as the disease progresses. The aim of management should be weaning the patient to the minimum support compatible with symptomatic relief and comfort. Respiratory failure should be anticipated in patients with MND when the diagnosis has been established.

[Early maladaptive processes, depression and alexithymia in suicidal hospitalized adolescents]

Alexithymia characterizes people having important difficulties in putting their feelings and moods into words. Adolescents' depression shows some peculiarities: one of them, which is often observed, is the equal difficulty of imparting one's feelings to others. This research concerns adolescents who attempted suicide. We study classical factors: depression and hopelessness. But our main objective is at first to study the relationship between attempted suicide, depression, hopelessness and alexithymia. The second objective of our study deals with the the prominent part of early schematas in this complex inter-relation. Maladaptative early schematas are no doubt involved in dysfunctional schematas found in depression and hopelessness. As a consequence, we would like to verify the following hypothesis: maladaptative early schematas are very numerous and specific among adolescents who attempted suicide. These schematas are the core of the complex inter-relation between attempted suicide, depression, hopelessness, suicide risk, suicide relapse and alexithymia. We have compared a group of normal subjects (who did not try to take their owns lives) and a group of people who did. First, we have found that the latter are more prone to alexithymia: a large majority of these subjects exceeds by far the accepted norm of the Toronto Alexithymia Scale. We have proved that the subjects who have attempted suicide also accumulate maladaptative early schematas. The qualitative analyse of these schematas leads to a possible explanation of the tendency to self destruction. Moreover there are apparently important differences between subjects who, in the past-experienced or did not experience a major depressive episode. The analysis of the relationships between the various factors of our study brings us to the conclusion that there is an unmistakable causal link between maladaptative early schematas and the interactive set (depression-hopelessness-major depressive episode-alexithymia) all these being part of attempted suicide and forming an integrant part of a whole which is the vulnerability to the suicide. Studying the various steps of early schematas seems to be quite promising as far as depression and suicide are concerned.

The development of Xenopus tropicalis transgenic lines and their use in studying lens developmental timing in living embryos

The generation of reporter lines for observing lens differentiation in vivo demonstrates a new strategy for embryological manipulation and allows us to address a long-standing question concerning the timing of the onset of differentiation. Xenopus tropicalis was used to make GFP reporter lines with (gamma)1-crystallin promoter elements directing GFP expression within the early lens. X. tropicalis is a close relative of X. laevis that shares the same ease of tissue manipulation with the added benefits of a diploid genome and faster life cycle. The efficiency of the Xenopus transgenic technique was improved in order to generate greater numbers of normal, adult transgenic animals and to facilitate in vivo analysis of the crystallin promoter. This transgene is transmitted through the germline, providing an accurate and consistent way to monitor lens differentiation. This line permitted us to distinguish models for how the onset of differentiation is controlled: by a process intrinsic to differentiating tissue or one dependent on external cues. This experiment would not have been feasible without the sensitivity and accuracy provided by the in vivo reporter. We find that, in specified lens ectoderm transplanted from neural tube stage donors to younger neural-plate-stage hosts, the onset of differentiation, as measured by expression of the crystallin/GFP transgene, is delayed by an average of 4.4 hours. When specified lens ectoderm is explanted into culture, the delay was an average of 16.3 hours relative to control embryos. These data suggest that the onset of differentiation in specified ectoderm can be altered by the environment and imply that this onset is normally controlled by external cues rather than by an intrinsic mechanism.

Respiratory insufficiency due to high anterior cervical cord infarction

OBJECTS AND METHODS

Respiratory dysfunction may occur as a result of lesions in the upper cervical spinal cord disturbing the descending pathways subserving automatic and volitional ventilatory control. Four patients are described who presented with acute respiratory insufficiency caused by infarction of the anterior portion of the upper cervical cord due to presumed anterior spinal artery occlusion.

RESULTS

Two patients presented after respiratory arrests; they were ventilated and there was no automatic or volitional respiratory effort. Both had signs of an extensive anterior spinal cord lesion at the C2 level and this was confirmed by MRI. One patient presented with a C4 infarction and required ventilation for three months. Ventilatory recovery was characterised by the development of an automatic respiratory pattern. The fourth patient required ventilation for two months after infarction at the C3 level. On attempted weaning he had prolonged periods of hypoventilation and apnoea during inattention and sleep indicating impairment of automatic respiratory control.

CONCLUSION

Infarction of the spinal cord at high cervical levels may be due to fibrocartilaginous embolism and involvement of the descending respiratory pathways may occur. Extensive lesions at C1/2 cause complete interruption of descending respiratory control leading to apnoea. Partial lesions at C3/4 cause selective interruption of automatic or voluntary pathways and give rise to characteristic respiratory patterns. The prognosis depends on the level and extent of the lesion.

Xenopus Brn-3.0, a POU-domain gene expressed in the developing retina and tectum. Not regulated by innervation

PURPOSE

To study the effect of denervation on the expression of the POU-domain gene Brn-3.0 in the Xenopus visual system.

METHODS

An oligonucleotide probe was used to identify homologs of the murine gene Brn-3.0 in the retina. In situ hybridization was used to determine the spatial distribution of the mRNA within the developing embryo. To study the effects of denervation on Brn-3.0 expression and cell fate, embryonic eyes were transplanted to an ectopic location on the animal (the flank) before the onset of retinal ganglion cell (RGC) axonogenesis. Gene expression in ectopic eyes and denervated tecta was analyzed over time using in situ hybridization.

RESULTS

The deduced, partial amino acid sequence for Xenopus Brn-3.0 shows 100% identity with the mouse Brn-3.0 and the human Brn-3a gene products. It is expressed during early embryonic development in distinct populations of the neural crest and later in specific cranial ganglia. It also is expressed in RGCs and in the optic tectum, beginning before the first RGC axons have reached the tectum and continuing without interruption throughout the period when retino-tectal connections are established and refined. If the retino-tectal projection is kept from forming by transplanting one eye to an ectopic location, Brn-3.0 expression is unaffected in both the ectopic eye and the denervated side of the tectum.

CONCLUSIONS

Coordinate expression of Brn-3.0 in afferent and efferent pathways suggests mutual regulation. However, the authors' evidence shows that expression in the retina is not regulated by target-derived factors nor is expression in the tectum regulated by retinal innervation.

Xenopus Pax-6 and retinal development

We have cloned a homolog of Pax-6 in Xenopus laevis. Its deduced amino acid sequence has a 95% overall identity with Pax-6 homologs in other vertebrates. It is expressed early in development in cells fated to form the eye and parts of the forebrain, hindbrain, and spinal cord. It has two phases of expression in the eye. In the early phase, from stage 12.5 to stage 33/34, Xenopus Pax-6 is expressed throughout the developing retina. In the late phase, after stage 33/34, it is excluded from mature cells in the outer half of the retina and from cells in the ciliary marginal zone, remaining only in amacrine and ganglion cells. Misexpression of Pax-6 early in development results in axial defects, but no specific eye phenotype is observed. Targeted misexpression in the retina at later stages does not result in any significant bias toward formation of amacrine or ganglion cells or away from photoreceptors. Ectopic expression of the proneural gene NeuroD alters the pattern of Pax-6, substantially reducing its expression in the eye field and later reducing or eliminating the eye itself. Our results show that Pax-6 expression appears to be necessary, but not sufficient, for eye formation in Xenopus.

Distinguishing cerebrospinal fluid from saline used to identify the extradural space

Because of the potential seriousness of unrecognized dural puncture during the performance of extradural analgesia and the widespread use of normal saline for the "loss of resistance" technique, it is important to differentiate between cerebrospinal fluid (CSF) and saline dripping from the extradural needle. During insertion of lumbar drains in 10 neurosurgical patients, we first identified the extradural space using saline for loss of resistance. Temperature (using the back of the gloved hand), pH, glucose and protein (using urine testing sticks) were tested by a blinded observer for ability to distinguish saline aspirated from the extradural space from CSF aspirated on establishing the dural puncture. Temperature, glucose and protein were independently 100% accurate in distinguishing saline from CSF. One saline sample had a pH value greater than 7 compared with nine CSF samples. We conclude that simple bedside testing for temperature, glucose, protein and pH accurately distinguished between CSF and saline used to identify the extradural space.

The evolution of heart, lung and liver transplantation services in Australia

The introduction and operation of heart, lung and liver transplantation services in Australia have been assisted by a Nationally Funded Centres policy adopted by health ministers. Assessment for eligibility for support under the program has been undertaken by the Australian Health Technology Advisory Committee. Outcomes/survival rates at transplantation centres have compared favourably with results from other countries. As in other countries, shortage of donor organs has limited the number of procedures undertaken. Some concern remains regarding the viability of newer transplantation programs which are now being established in smaller centres of population.

Comparison of direct blood pressure measurement at the radial and dorsalis pedis arteries during surgery in the horizontal and reverse Trendelenburg positions

The differences in simultaneous arterial pressure measurements from the radial and dorsalis pedis arteries were studied in anaesthetised adult patients in either the horizontal or reverse Trendelenburg position. Significantly higher pressures were measured from the dorsalis pedis artery than from the radial artery in both positions, even allowing for the hydrostatic effect on the dorsalis pedis arterial pressure in the non-horizontal group. If the dorsalis pedis artery is to be used to measure direct arterial blood pressure, we recommend that readings be compared with an arm sphygmomanometer to avoid potentially dangerous hypotension being missed.

Acute and chronic effects of winter swimming on LH, FSH, prolactin, growth hormone, TSH, cortisol, serum glucose and insulin

The present investigation is based on a 2.5 months selbstversuch (self-experiment) of the authors, between October 21 1992, and January 6 1993. 11 healthy students, five females and six males, age 24 to 29 years, and their teachers underwent regular winter swimming at least once a week, for 2 to 10 minutes, at the natural water temperature (6.8 degrees C (October 1992) to 2.0 degrees C (January 1993)) in the southern Baltic Sea. Blood samples were drawn before and 30 and 60 minutes after the cold bath, both at the first and the last day of the swimming season. TSH increased from 0.96 mU/l to 1.42 mU/l (p < 0.01) in the untrained, and from 0.93 mU/l to 1.43 mU/l (p < 0.01) in the cold-trained persons, and decreased thereafter (p < 0.01). Similar changes occurred in cortisol serum concentrations, though psychological stress seemed to interfere with cold stress. Cortisol increased from 99 ng/ml to 133 ng/ml in the untrained, and from 101 ng/ml to 137 ng/ml (p < 0.05) in the cold-trained persons within 30 minutes after cold water immersion, and decreased thereafter (p < 0.01). There were mild decreases in prolactin serum levels after cold stress, whereas FSH, LH and growth hormone remained unaltered. There was a mild initial elevation of serum glucose after cold stress (plus 12 mg/dl, (p < 0.01)) which disappeared after training. There were long term training effects besides the effects on glucose: Basal prolactin levels increased by almost the factor two, and insulin serum levels dropped by almost 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

The evolution of laparoscopic surgery in routine health care

While laparoscopic cholecystectomy is now widely used, diffusion of other laparoscopic surgical methods has been more modest. Uptake of most laparoscopic methods has been influenced by considerations of effectiveness compared with open surgery, competing minimally invasive therapies, and the inconvenience and cost of technical change.

The status of laparoscopic surgery in Australia

Laparoscopic surgery continues to evolve and to offer major potential for achieving benefits to patients and to health care providers because of decreased morbidity. Laparoscopic cholecystectomy has diffused rapidly and widely. However, the spread of other minimal access surgery methods has been more gradual, reflecting uncertainties as to the degree of benefit and rate of change of technology. Firm evidence of efficacy and costs of the new methods is still limited, and a number of organisational issues continue to demand attention.

[HLA typing in high risk keratoplasty]

Improved microsurgical techniques and better immunosuppressive treatment have led to an increase in the number of corneal transplantations. However, graft rejection due to a disparity between donor and recipient major histocompatibility antigens remains the major complication. The risk of graft rejection is further increased in patients with vascularized graft beds and in presensitized persons. Well-designed experimental studies and clinical experience have clearly shown the importance of class-I-antigens. However, class-II antigens have not yet been studied to the same extent.

METHODS

Multiorgan donors and corneal graft recipients were HLA typed using the lymphocytotoxicity test previously described by Terasaki. The recipients were typed retrospectively. Cadaver corneal graft donors were typed using a novel HLA typing technique on retinal pigment epithelial cells, as previously described by us. Postoperatively, all recipients were routinely examined for rejection over a period of 2 years.

RESULTS

Graft rejection was observed in 25% of the 133 high-risk patients. Of the 13 class-I-typed patients who showed a rejection 9 persons had two or more major histocompatibility mismatches. Of the 12 patients without rejection problems only 5 had two or more HLA class-I-mismatches. Of the patients with one or two matches at the HLA-DR locus there were only 4 out of 9 patients with at least one graft rejection; 5 out of 6 patients showed no signs of rejection.

CONCLUSIONS

Mismatches at either class-I- or class-II- gene loci lead to a higher frequency in corneal graft rejection. Apart from the major histocompatibility mismatches, other factors also influence graft rejection, such as the distance between the corneal transplant and corneal vessels, presensitization, and the indication for corneal grafting. If we are to define the factors influencing graft rejection better and further increase our knowledge on the role the major histocompatibility antigens play in corneal graft rejection in a larger patient group, then cooperation with other transplantation centers will be required.

Pipecuronium versus high dose vecuronium

The onset time and tendency to cumulation of pipecuronium and high-dose vecuronium were compared during nitrous oxide anaesthesia supplemented with a propofol infusion. Pipecuronium 0.06 mg.kg-1 had a similar duration of action to vecuronium 0.2 mg.kg-1 (49 vs 43). Patients who received vecuronium had a shorter onset time of neuromuscular blockade (p less than 0.01). Neither pipecuronium nor vecuronium showed marked cumulation.

Superior sagittal sinus thrombosis after internal jugular vein cannulation

A case of cerebral venous sinus thrombosis after central venous cannulation is presented. This occurred after a catheter had been in place for 5 days. The patient presented with thrombosis of the left internal jugular vein 4 days after removal of the catheter. Despite anticoagulation, the patient developed symptoms of increased intracranial pressure. Subsequently, a diagnosis of superior sagittal sinus thrombosis was made. The aetiology, diagnosis and management of this uncommon complication of central venous cannulation are discussed.

Effect of arterial carbon dioxide tension on the duration of action of atracurium

The duration of action of atracurium was studied in two groups of patients. In group I (n = 15), patients' lungs were hyperventilated to a mean PaCO2 of 3.3 kPa and in group II (n = 15) lungs were ventilated to maintain a mean PaCO2 of 5.3 kPa. Anaesthesia was maintained using an infusion of propofol. The time taken to return to a T1 twitch height of 10% of control was measured following each incremental dose of atracurium 0.15 mg kg-1. It was found that the duration of action of atracurium was significantly (P less than 0.0005) shorter in the hypocapnic group.

An unusual complication of tracheal intubation

We report a previously undescribed complication of tracheal intubation. The complication arose as a result of tracheal intubation performed as an emergency procedure in a patient with an abnormal anteriorly placed larynx. Subsequent corrective laryngeal surgery was required after a temporary tracheostomy had been performed.

Diaphragmatic weakness in hereditary motor and sensory neuropathy

Six patients severely affected by hereditary motor and sensory neuropathy (HMSN), four type I and two type II, had clinical evidence of diaphragmatic weakness. One presented with cardiorespiratory failure secondary to nocturnal hypoventilation, and three others were unable to lie flat because of dyspnoea. Diaphragmatic paralysis should be considered as a cause of respiratory or cardiac failure in cases of HMSN.

Prevalence of mandibular dysfunction in 10-18 year old Israeli schoolchildren

The prevalence of mandibular dysfunction in a sample of 369 Israeli schoolchildren was found to be 56.4%, indicating that one or more of the cardinal symptoms were present. It increased with age from about 51% in the 10-13 year old group to 67.8% in the 16-18 year olds. The most common cardinal sign of dysfunction was joint sounds (35.8%), which increased with age from 28% in the youngest group to 44.3% in the oldest group. The second most common sign was joint sensitivity to palpation (30.4%), which showed a slight increase in the oldest group. Sensitivity of the superficial muscles was recorded third, with 20%. Joint pain and restriction of mandibular movement appeared infrequently. Two of the more common cardinal symptoms, namely joint sounds and muscle sensitivity, were statistically related to several possible aetiological factors and to age and sex. Analysis of association showed that the probability of muscle sensitivity increased in the presence of malocclusion and/or joint sensitivity to palpation. It also showed that age, occlusal wear, locking of the jaw and joint sensitivity to palpation increased the probability of joint sounds.