AZGP1 deficiency promotes angiogenesis in prostate cancer

BACKGROUND

Loss of AZGP1 expression is a biomarker associated with progression to castration resistance, development of metastasis, and poor disease-specific survival in prostate cancer. However, high expression of AZGP1 cells in prostate cancer has been reported to increase proliferation and invasion. The exact role of AZGP1 in prostate cancer progression remains elusive.

METHOD

AZGP1 knockout and overexpressing prostate cancer cells were generated using a lentiviral system. The effects of AZGP1 under- or over-expression in prostate cancer cells were evaluated by in vitro cell proliferation, migration, and invasion assays. Heterozygous AZGP1± mice were obtained from European Mouse Mutant Archive (EMMA), and prostate tissues from homozygous knockout male mice were collected at 2, 6 and 10 months for histological analysis. In vivo xenografts generated from AZGP1 under- or over-expressing prostate cancer cells were used to determine the role of AZGP1 in prostate cancer tumor growth, and subsequent proteomics analysis was conducted to elucidate the mechanisms of AZGP1 action in prostate cancer progression. AZGP1 expression and microvessel density were measured in human prostate cancer samples on a tissue microarray of 215 independent patient samples.

RESULT

Neither the knockout nor overexpression of AZGP1 exhibited significant effects on prostate cancer cell proliferation, clonal growth, migration, or invasion in vitro. The prostates of AZGP1-/- mice initially appeared to have grossly normal morphology; however, we observed fibrosis in the periglandular stroma and higher blood vessel density in the mouse prostate by 6 months. In PC3 and DU145 mouse xenografts, over-expression of AZGP1 did not affect tumor growth. Instead, these tumors displayed decreased microvessel density compared to xenografts derived from PC3 and DU145 control cells, suggesting that AZGP1 functions to inhibit angiogenesis in prostate cancer. Proteomics profiling further indicated that, compared to control xenografts, AZGP1 overexpressing PC3 xenografts are enriched with angiogenesis pathway proteins, including YWHAZ, EPHA2, SERPINE1, and PDCD6, MMP9, GPX1, HSPB1, COL18A1, RNH1, and ANXA1. In vitro functional studies show that AZGP1 inhibits human umbilical vein endothelial cell proliferation, migration, tubular formation and branching. Additionally, tumor microarray analysis shows that AZGP1 expression is negatively correlated with blood vessel density in human prostate cancer tissues.

CONCLUSION

AZGP1 is a negative regulator of angiogenesis, such that loss of AZGP1 promotes angiogenesis in prostate cancer. AZGP1 likely exerts heterotypical effects on cells in the tumor microenvironment, such as stromal and endothelial cells. This study sheds light on the anti-angiogenic characteristics of AZGP1 in the prostate and provides a rationale to target AZGP1 to inhibit prostate cancer progression.

NUSAP1 Binds ILF2 to Modulate R-Loop Accumulation and DNA Damage in Prostate Cancer

Increased expression of NUSAP1 has been identified as a robust prognostic biomarker in prostate cancer and other malignancies. We have previously shown that NUSAP1 is positively regulated by E2F1 and promotes cancer invasion and metastasis. To further understand the biological function of NUSAP1, we used affinity purification and mass spectrometry proteomic analysis to identify NUSAP1 interactors. We identified 85 unique proteins in the NUSAP1 interactome, including ILF2, DHX9, and other RNA-binding proteins. Using proteomic approaches, we uncovered a function for NUSAP1 in maintaining R-loops and in DNA damage response through its interaction with ILF2. Co-immunoprecipitation and colocalization using confocal microscopy verified the interactions of NUSAP1 with ILF2 and DHX9, and RNA/DNA hybrids. We showed that the microtubule and charged helical domains of NUSAP1 were necessary for the protein-protein interactions. Depletion of ILF2 alone further increased camptothecin-induced R-loop accumulation and DNA damage, and NUSAP1 depletion abolished this effect. In human prostate adenocarcinoma, NUSAP1 and ILF2 mRNA expression levels are positively correlated, elevated, and associated with poor clinical outcomes. Our study identifies a novel role for NUSAP1 in regulating R-loop formation and accumulation in response to DNA damage through its interactions with ILF2 and hence provides a potential therapeutic target.

Hyperactivity of Mek in TNS1 knockouts leads to potential treatments for cystic kidney diseases

Cystic kidney disease is the progressive development of multiple fluid-filled cysts that may severely compromise kidney functions and lead to renal failure. TNS1 (tensin-1) knockout mice develop cystic kidneys and die from renal failure. Here, we have established TNS1-knockout MDCK cells and applied 3D culture system to investigate the mechanism leading to cyst formation. Unlike wild-type MDCK cells, which form cysts with a single lumen, TNS1-knockout cysts contain multiple lumens and upregulated Mek/Erk activities. The multiple lumen phenotype and Mek/Erk hyperactivities are rescued by re-expression of wild-type TNS1 but not the TNS1 mutant lacking a fragment essential for its cell–cell junction localization. Furthermore, Mek inhibitor treatments restore the multiple lumens back to single lumen cysts. Mek/Erk hyperactivities are also detected in TNS1-knockout mouse kidneys. Treatment with the Mek inhibitor trametinib significantly reduces the levels of interstitial infiltrates, fibrosis and dilated tubules in TNS1-knockout kidneys. These studies establish a critical role of subcellular localization of TNS1 in suppressing Mek/Erk signaling and maintaining lumenogenesis, and provide potential therapeutic strategies by targeting the Mek/Erk pathway for cystic kidney diseases.

An Evaluation of the Modified Airway Management Device

This is a preliminary report on the use of the modified Airway Management Device in 50 spontaneously breathing patients undergoing elective day care surgery.

We were successful in establishing a clear airway in all 50 patients, 46 of these patients had a patent airway on the first attempt. All patients were successfully managed with the Airway Management Device throughout the surgery.

Partial airway obstruction during maintenance of anaesthesia occurred in three cases requiring only minor manipulations. Our result showed that the Airway Management Device may be used as an alternative airway management in anaesthesia.

Randomized Double-blind Comparison of Ketamine-Propofol, Fentanyl-Propofol and Propofol-Saline on Haemodynamics and Laryngeal Mask Airway Insertion Conditions

The aim of this prospective, double-blind, randomized, placebo-controlled clinical trial was to investigate whether the administration of ketamine before induction with propofol improves its associated haemodynamic profile and laryngeal mask airway (LMA) insertion conditions. Ninety adult patients were randomly allocated to receive either ketamine 0.5 mg.kg-1 (n=30), fentanyl 1 μg.kg-1 (n=30) or normal saline (n=30), before induction of anaesthesia with propofol 2.5 mg.kg-1. Insertion of the LMA was performed 60s after injection of propofol. Arterial blood pressure and heart rate were measured before induction (baseline), immediately after induction, immediately before LMA insertion, immediately after LMA insertion and every minute for three minutes after LMA insertion. Following LMA insertion, the following six subjective endpoints were graded by a blinded anaesthestist using ordinal scales graded 1 to 3: mouth opening, gagging, swallowing, movement, laryngospasm and ease of insertion. Systolic blood pressure was significantly higher following ketamine than either fentanyl (P=0.010) or saline (P=0.0001). The median (interquartile range) summed score describing the overall insertion conditions were similar in the ketamine [median 7.0, interquartile range (6.0–8.0)] and fentanyl groups [median 7.0, interquartile range (6.0–8.0)]. Both appeared significantly better than the saline group [median 8.0, interquartile range (6.75–9.25); P=0.024]. The incidence of prolonged apnoea (>120s) was higher in the fentanyl group [23.1% (7/30)] compared with the ketamine [6.3% (2/30)] and saline groups [3.3% (1/30)]. We conclude that the addition of ketamine 0.5 mg.kg–1 improves haemo-dynamics when compared to fentanyl 1 μg.kg–1, with less prolonged apnoea, and is associated with better LMA insertion conditions than placebo (saline).

Polygonum multiflorum Decreases Airway Allergic Symptoms in a Murine Model of Asthma

The root of Polygonum multiflorum (also called He-Shou-Wu in Chinese) is a common herb and medicinal food in Asia used for its anti-aging properties. Our study investigated the therapeutic potential of an extract of the root of Polygonum multiflorum (PME) in allergic asthma by using a mouse model. Feeding of 0.5 and 1 mg/mouse PME inhibited ovalbumin (OVA)-induced allergic asthma symptoms, including airway inflammation, mucus production, and airway hyper-responsiveness (AHR), in a dose-dependent manner. To discern PME's mechanism of action, we examined the profile and cytokine production of inflammatory cells in bronchial alveolar lavage fluid (BALF). We found that eosinophils, the main inflammatory cell infiltrate in the lung of OVA-immunized mice, significantly decreased after PME treatment. Th2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13, eotaxin, and the proinflammatory cytokine tumor necrosis factor (TNF)-[Formula: see text], decreased in PME-treated mice. Elevated mRNA expression of Th2 transcription factor GATA-3 in the lung tissue was also inhibited after oral feeding of PME in OVA-immunized mice. Thus, we conclude that PME produces anti-asthma activity through the inhibition of Th2 cell activation.

Targeting myristoylated alanine-rich C kinase substrate phosphorylation site domain in lung cancer. Mechanisms and therapeutic implications

RATIONALE

Phosphorylation of myristoylated alanine-rich C kinase substrate (phospho-MARCKS) at the phosphorylation site domain (PSD) is crucial for mucus granule secretion and cell motility, but little is known concerning its function in lung cancer.

OBJECTIVES

We aimed to determine if MARCKS PSD activity can serve as a therapeutic target and to elucidate the molecular basis of this potential.

METHODS

The clinical relevance of phospho-MARCKS was first confirmed. Next, we used genetic approaches to verify the functionality and molecular mechanism of phospho-MARCKS. Finally, cancer cells were pharmacologically inhibited for MARCKS activity and subjected to functional bioassays.

MEASUREMENTS AND MAIN RESULTS

We demonstrated that higher phospho-MARCKS levels were correlated with shorter overall survival of lung cancer patients. Using shRNA silencing and ectopic expression of wild-type and PSD-mutated (S159/163A) MARCKS, we showed that elevated phospho-MARCKS promoted cancer growth and erlotinib resistance. Further studies demonstrated an interaction of phosphoinositide 3-kinase with MARCKS, but not with phospho-MARCKS. Interestingly, phospho-MARCKS acted in parallel with increased phosphatidylinositol (3,4,5)-triphosphate pools and AKT activation in cells. Through treatment with a 25-mer peptide targeting the MARCKS PSD motif (MPS peptide), we were able to suppress tumor growth and metastasis in vivo, and reduced levels of phospho-MARCKS, phosphatidylinositol (3,4,5)-triphosphate, and AKT activity. This peptide also enhanced the sensitivity of lung cancer cells to erlotinib treatment, especially those with sustained activation of phosphoinositide 3-kinase/AKT signaling.

CONCLUSIONS

These results suggest a key role for MARCKS PSD in cancer disease and provide a unique strategy for inhibiting the activity of MARCKS PSD as a treatment for lung cancer.

The expression of placental soluble fms-like tyrosine kinase 1 in mouse placenta varies significantly across different litters from normal pregnant mice

OBJECTIVE

Gene expression studies often pool tissues from multiple placentas when using animal models of preeclampsia without accounting for the potential confounders of litter origin or pup sex. We aimed to determine whether placental gene expression differs based on sex or litter.

METHODS

We examined the differential expression of soluble fms-like tyrosine kinase 1 (Flt-1) using 35 pups from six normal pregnant mice.

RESULTS

Expression of sFlt-1 (p = 0.003) was significantly different between litters but not between sexes (p = 0.17).

CONCLUSIONS

These findings highlight the importance of adequate sampling from multiple litters in expression studies when using animal models in clinical research.

OS055. Sex-dependent differences in expression of FLT-1 variants andJMJD6 in mouse placenta

INTRODUCTION

There is evidence for fetal sex-dependent differences in the way in which preeclamptic pregnancies proceed, and in maternal and neonatal outcomes. Mouse models are common in the study of preeclampsia and pooled tissue from multiple placentae is often used to obtain samples for expression studies. Potential concerns regarding this practice are the sex-dependent differences in placental expression of candidate factors. One biomolecule of interest is soluble fms-like tyrosine kinase 1 (sFLT-1) which is a known marker of preeclampsia and commonly used to determine the severity of the induced preeclampsia-like syndrome in rodent models.

OBJECTIVES

It was the aim of this preliminary study to determine whether variation exists in the expression of different genes in murine placenta based on pup sex in C57BL/6JArc mice. A novel gene, Jumonji domain-containing protein 6 (Jmjd6) that may prove to have a role in the pathogenesis of preeclampsia, mFLT-1 and sFLT-1 were selected as targets.

METHODS

Seventeen pups were retrieved from three normal pregnant female mice euthanized via cervical dislocation (CD) on day 17.5 or 18.5. Tails and corresponding placentas were collected from the pups, snap frozen in liquid nitrogen and stored at -80°C. Tails were used to accurately determine pup sex via PCR amplification of sex chromosome-specific sequences and revealed the presence of 3 females and 14 males. Quantitative PCR was used to determine the relative expression of the FLT-1 and Jmjd6 transcripts in each placenta. The placenta collected from the first pup of the first pregnant female served as the reference sample and transcript expression in the remaining samples was expressed relative to this sample. General linear modelling using linear regression with categorical variables was used to evaluate the difference in transcript expression between the sexes and Pearson's correlation coefficient used to examine relationships between variables.

RESULTS

Pup sex was found to have a significant effect on the relative expression of sFLT-1 after controlling for litter, pup weight and gestational age (p=0.013), with 1.5 times more expression in the placentas of female pups. The expression of sFLT-1 was highly correlated with mFLT-1 (r=0.690,p=0.002). The relative expression of Jmjd6 was not significantly different in male and female placentas and sFlt-1 was not correlated with Jmjd6.

CONCLUSION

This is the first study to demonstrate a link between fetal sex and placental sFLT-1 expression in mice, finding increased levels of this gene in the placentas of female pups. It is possible that in normal pregnancies, female placentas produce more sFLT-1 which acts to condition them and offer some protection during the sFLT-1 spike seen in preeclampsia. The findings of this study also highlight a possible need to consider sex as a variable in placental expression studies using mice to ensure the accuracy of results.

Impact of bispectral index monitoring on propofol administration in patients undergoing cardiopulmonary bypass

Propofol anaesthesia using target control infusion during cardiac surgery has become more popular recently. However, without depth of anaesthesia monitoring, the standard target concentration used may be higher than necessary to maintain adequate hypnosis during hypothermic cardiopulmonary bypass. The purpose of this study was to evaluate the effect of bispectral index monitoring on propofol administration during hypothermic cardiopulmonary bypass. After ethics committee approval and written informed consent, 20 New York Heart Association class I-III patients scheduled for elective cardiac surgery requiring hypothermic cardiopulmonary bypass were studied in this prospective randomised controlled trial. In group C, routine anaesthesia was practised, where patients received propofol at target concentration between 1.5 to 2.5 microg/ml during cardiopulmonary bypass. In group B, the target concentration was titrated to a bispectral index value of 40 to 50. Mean arterial pressure and bispectral index were recorded at various time intervals. The use of propofol, phenylephrine, sodium nitroprusside and adrenaline were recorded. The median propofol administration in group B was significantly less than that in group C (2.9 mg/kg/h compared to 6.0 mg/kg/h). The bispectral index value during bypass was significantly lower in group C than in group B, reflecting a deeper state of anaesthesia. There was no difference in the use of inotropes, vasoconstrictors or vasodilators. Bispectral index monitoring enables a 50% reduction in propofol administration at this standard dose during hypothermic cardiopulmonary bypass.

The contents and forms of solid-phase species of radioactive strontium and cesium in Taiwan soils

This study was to investigate the activities and contents of (137)Cs in the profiles of selected arable and forest soils in Taiwan and various solid-phase species of (85)Sr and (137)Cs in selected arable soils in Taiwan. The gamma (gamma) ray spectra of the collected soil samples and some of the soils amended with (85)Sr and (137)Cs were measured. The data indicate that the arable soils from Sanhsing series, Sanhsing Township and Chuangwei series, Chuangwei Township, Ilan County, and from Tunglochuan series, Pinglin Township, Taipei County shows significantly higher radioactivity of (137)Cs (ND - 11.0 +/- 0.2 Bq kg(-1)). Furthermore, the radioactivity of (137)Cs in the mountain soils (1.24 +/- 0.07 - 42 +/- 1 Bq kg(-1)) from Yuanyang Lake Nature Preserve among Ilan, Taoyuan, and Hsinchu Counties is the highest among the investigated mountain forest soils. This may be mainly attributed to the fact that Ilan County is located in the northeastern part of Taiwan and faces the northeastern and northern seasonal winds with lots of precipitation annually from mid-autumn through mid-spring next year and is receiving greater amount of fallouts yearly. Due to longer reaction period (>or=3 y) of (137)Cs with soil components, (137)Cs was mainly in the forms bound to oxides and to organic matter in the soil amended with (137)Cs and in the soil contaminated with (137)Cs. On the contrary, due to shorter reaction period (<60 d) of (85)Sr with soil components, (85)Sr was mainly in exchangeable form and partially in the forms bound to carbonates and oxides in the soils amended with (85)Sr.

Temporary cardiopulmonary bypass and isolated lung ventilation for tracheal stenosis and reconstruction

A 27-yr-old lady with a past history of prolonged ventilation presented with worsening respiratory distress caused by tracheal stenosis. She required urgent tracheal resection and reconstruction. Because of the risk of an acute respiratory obstruction, spinal anaesthesia was used to establish cardiopulmonary bypass by cannulating the femoral artery and femoral vein. Adequate gas exchange was possible with full flow rate. Thoracotomy was then carried out to mobilize the left main bronchus. After successfully securing an airway by intubation of the left main bronchus, cardiopulmonary bypass was discontinued and tracheal resection and anastomosis was done under conventional one lung anaesthesia.

The use of modified VBM laryngeal tube compared to Laryngeal Mask Airway during spontaneous ventilation

We have compared the use of the laryngeal mask airway with the new modified laryngeal tube in a prospective randomized controlled study. Sixty ASA 1 or 2 patients, aged 18 to 65 years, scheduled for elective surgery and breathing spontaneously under general anaesthesia, were studied. After preoxygenation, anaesthesia was induced with fentanyl and propofol. The patients were randomized to receive either a laryngeal mask airway or a laryngeal tube. Anaesthesia was maintained with nitrous oxide, oxygen and isoflurane. We recorded the speed and the ease of insertion, the number of attempts needed to successfully secure the airway and intraoperative complications, such as partial airway obstruction needing airway manipulation. The airway devices were removed with the patients fully awake at the end of surgery. Systolic arterial blood pressure, heart rate and end-tidal CO2 were recorded at various time intervals. Postoperative complications were recorded. We found that the incidence of partial airway obstruction needing intraoperative airway manipulation was higher with the laryngeal tube than with the laryngeal mask airway. We conclude that during spontaneous ventilation the modified laryngeal tube is not as reliable in providing a satisfactory airway and we consider it is not a suitable alternative to the laryngeal mask airway.

Retrospective review of spinal versus epidural anaesthesia for caesarean section in preeclamptic patients

A 5-year retrospective survey of anaesthesia for caesarean section for mild/moderate and severe preeclampsia was performed, covering the period between 1 January 1996 and 31 December 2000. One hundred and twenty-one cases of non-labouring preeclamptic patients receiving spinal or epidural anaesthesia for caesarean section were included for analysis. Comparisons were made of the lowest blood pressures recorded before induction of anaesthesia, during the period from induction to delivery and the period from delivery to the end of operation. The decreases in blood pressure were similar after spinal and epidural anaesthesia. The use of intravenous fluids and ephedrine were also comparable in the two anaesthetic groups. There was no difference in maternal or neonatal outcome. Our result supports the use of spinal anaesthesia in preeclamptic women.

A comparative study of sevoflurane sedation with nitrous oxide sedation for dental surgery

This study compares the use of inhalation sedation using sevoflurane (group S) with inhalation sedation using nitrous oxide (group N) in patients undergoing bilateral extraction of third molar teeth under local anaesthesia. The study was designed as a cross-over study. Seventeen ASA I, day surgery patients were studied. Patients were randomly allocated to receive either 8 l/min 50% nitrous oxide in oxygen (group N) or same flow of 1% sevoflurane (group S) for the first procedure. Each patient then had the alternate method of sedation for the second procedure. There were no significant differences between the methods in patient co-operation and surgeon's satisfaction with sedation. Psychomotor tests were comparable in both groups. The patients were significantly more sedated in the group S compared to group N (P=0.004). Significantly more patients complained of an unpleasant odour group S (P<0.01) but none withdrew from the study for this reason. No adverse cardiorespiratory effects resulted from sevoflurane or nitrous oxide sedation. Both methods gave good amnesia during the procedure. There was high acceptance of both methods and the patients rated the technique as equally satisfactory. We conclude that inhalation sedation with sevoflurane is a suitable alternative method to nitrous oxide sedation.

Trends in obstetric anaesthesia and analgesia over a ten year period in the University Malaya Medical Centre, Kuala Lumpur

Available data for obstetric care in the University Malaya Medical Centre, Kuala Lumpur from 1987 to 1999 were reviewed. Despite incomplete data, we were able to determine fairly well the practice of obstetric anaesthesia and analgesia in the unit, and the changes over the years. There was a decline in the use of general anaesthesia for both elective and emergency caesarean sections from 41.3% and 69.4% respectively in 1995 to 21.6% and 26.9% respectively in 1999. By 1999, regional anaesthesia had become the most common method of anaesthesia administered in both elective (14.3% epidural and 63.5% spinal) and emergency (30.2% epidural and 42.6% spinal) caesarean sections. The percentage of patients delivering vaginally who received epidural analgesia appeared to have stabilised at about 8 to 9% in the last few years, with a gradual decline in the total instrumental delivery rate from a high of about 12% to the pre-epidural rate of 7%.

The effect of prophylactic metaraminol on systemic hypotension caused by induction of anaesthesia with propofol in patients over 55 years old

We conducted a double-blind, randomised, placebo-controlled study evaluating the efficacy of prophylactic metaraminol for preventing propofol-induced hypotension. Thirty patients aged 55-75 years undergoing general anaesthesia were randomly allocated to receive either metaraminol 0.5 mg or saline before administration of fentanyl 1 microg.kg(-1) and propofol 2 mg.kg(-1). Induction of anaesthesia was associated with a decrease in mean and systolic arterial pressure in both groups (p = 0.0001). However, there was no significant difference between the two groups. These results show that prophylactic use of metaraminol 0.5 mg does not prevent the decrease in blood pressure following fentanyl and propofol induction in older patients.

Fatal hepatorenal failure associated with hydrazine sulfate

BACKGROUND

The Internet has revolutionized the manner in which patients obtain information about health care. This technology has also allowed patients to obtain directly both prescription and nonprescription therapies.

OBJECTIVE

To report a case of fulminant hepatorenal failure associated with the use of hydrazine sulfate, an unregulated alternative remedy for cancer marketed on the Internet.

DESIGN

Case report.

SETTING

Academic medical center.

PATIENT

A 55-year-old man with maxillary sinus cancer.

INTERVENTION

Self-medication with hydrazine sulfate.

MEASUREMENTS

Serum liver and renal function tests; histologic evaluation of liver and kidney tissue.

RESULTS

The patient developed hepatic encephalopathy, renal failure, and profound coagulopathy. He died after severe gastrointestinal hemorrhage developed. Autopsy revealed autolysis of the kidneys and submassive bridging necrosis of the liver.

CONCLUSION

Fatal hepatorenal failure may occur after the use of hydrazine sulfate. This fatal complication must be considered in anyone taking or contemplating the use of hydrazine sulfate.

A comparison of the maintenance and recovery charcateristic of sevoflurane-nitrous oxide against isoflurane-nitrous oxide anaesthesia

BACKGROUND

To compare the maintenance and recovery characteristics of sevoflurane and isoflurane anaesthesia in Malaysian patients.

METHOD

This is a prospective, open labelled, randomized, controlled study. Sixty unpremedicated ASA I or II patients (aged 18-50 years), scheduled for elective breast lump excision were randomly allocated to receive either isoflurane or sevoflurane for the maintenance of anaesthesia following fentanyl and propofol intravenous induction. The systolic, diastolic, mean arterial blood pressure and heart rate were measured. The speed of recovery was measured by time to eye opening, time to following simple command, and time to correctly giving own names and address. The incidence of postoperative complication was also recorded.

RESULTS

The trend of systolic blood pressure was significantly higher in the isoflurane group as compared to the sevoflurane group for the duration of anaesthesia (p < 0.001, by ANOVA for repeated measurement) but the trend of heart rate was similar for both groups. The recovery time was faster in the isoflurane group. [mean time of eye opening (SD) = 6.8 (2.2) vs 10.7 (4.4) min, p < 0.001; mean time of sticking tongue out (SD) = 7.9 (2.9) vs 11.5 (4.7) min, p < 0.01; mean time of giving own name (SD) = 7.8 (2.7) vs 11.8 (4.8) min, p < 0.001, mean time of giving own address (SD) = 8.4 (2.9) vs 12.0 (4.7) min, p < 0.01]. No major adverse effects were encountered postoperatively and the incidences of minor adverse effects were low in both groups.

CONCLUSION

We concluded that sevoflurane is a safe alternative to isoflurane but in these short procedures, awakening time was surprisingly slower than after isoflurane.

Which and what headache were we treating? Epidural blood patch for atypical headache following obstetric epidural anaesthesia

We present a case of headache following epidural anaesthesia for caesarean section. The patient did not exhibit the classical features of post dural puncture headache and the cause was uncertain. The headache was complicated by post partum seizure and a history of pregnancy-induced hypertension. A diagnostic lumbar puncture had to be done to exclude meningitis as she had a raised white blood count. An epidural blood patch performed 12 days post partum resolved the headache immediately.

Assessing the implant/bone interface by using natural frequency analysis

OBJECTIVE

A number of techniques have been proposed for detecting the stability of dental implants. However, the clinical applicability of those methods is still limited. The purpose of this study was to evaluate a new innovative, noninvasive, minimum-contact method for the stability assessment of dental implants.

STUDY DESIGN

Natural frequency is a physical property of a structure, which is strongly related to its boundary conditions. In this study, a modal testing technique was carried out to measure the natural frequency of dental implants. The implants were fixed by a metal clamp stand and were excited to vibrate by an impulse hammer. A noncontact piezoelectric microphone then acoustically acquired the vibration responses of the implants. Natural frequencies of the tested implants were recorded under various clamping forces and clamping levels.

RESULTS

Natural frequencies of the tested implants were concentrated from 8 to 19 kHz under different boundary conditions. On the other hand, the natural frequency values decreased when boundary levels and boundary force were reduced. Linear relationships (P <.005) were found between response frequencies and the degree of implant stability.

CONCLUSIONS

Our results show that the boundary status of an implant can be monitored by detecting its natural frequency. A noncontact transducer used in this study can also serve as a useful tool for future clinical investigations.

Treatment of chronic urticaria with thyroxine in an euthyroid patient with thyroglobulin and microsomal antibodies

INTRODUCTION

The association of chronic urticaria and thyroid autoimmunity is not well recognised and the potential use of thyroxine in the treatment of chronic urticaria in patients with thyroid autoimmunity is even less well known.

CLINICAL PICTURE

We report a case of chronic urticaria in an euthyroid patient with evidence of significantly elevated levels of thyroglobulin and microsomal antibodies.

TREATMENT AND OUTCOME

Treatment with thyroxine has brought about clinical remission of the chronic urticaria but no change in the thyroid antibody levels could be demonstrated.

CONCLUSION

Patients with chronic urticaria should be screened for evidence of thyroid autoimmunity. A closely monitored trial of thyroxine therapy for those who have thyroid autoimmunity can be rewarding.

Subcutaneous emphysema and pneumomediastinum after endotracheal anaesthesia

INTRODUCTION

We report a case of subcutaneous emphysema and pneumomediastinum that presented postoperatively after tracheal extubation.

CLINICAL PICTURE

A 51-year-old man had an uneventful anaesthesia lasting about 6.5 hours. Intubation was performed by a very junior medical officer and was considered difficult. He developed sore throat, chest pain, numbness of both hands and palpable crepitus around the neck postoperatively. Chest X-ray revealed diffuse subcutaneous emphysema, pneumomediastinum and possible pneumopericardium.

TREATMENT

He was treated conservatively with bed rest, oxygen, analgesia, antibiotic prophylaxis, reassurance and close monitoring.

OUTCOME

The patient made an uneventful recovery.

CONCLUSIONS

We discussed the possible causes.

A comparison of the induction and emergence characteristics of sevoflurane and halothane in children

This open labelled, randomised, controlled study was designed to compare the induction and recovery characteristics of sevoflurane and halothane anaesthesia in children. Forty American Society of Anaesthesiologist (ASA) physical status class 1 or 2 children (aged 1-10 year, weighed less than 25 kg) scheduled for elective urological procedure lasting less than one hour were allocated randomly to receive either sevoflurane (group S, n = 20) or halothane (group H, n = 20). The induction time in children receiving sevoflurane was significantly shorter than in those receiving halothane (mean (SD) 46 (13.6) second vs 69 (19.4) seconds, p < 0.005). The emergence from anaesthesia was also faster in children receiving sevoflurane than in those receiving halothane (mean (SD) 9 min (4.3 min) vs 21 min (8.9 min), p < 0.001). No major adverse effects were encountered in each group. We concluded that sevoflurane is comparable to halothane in Malaysian children.

Sevoflurane for dental extraction in children with Tetralogy of Fallot

Two children with Tetralogy of Fallot presented for dental extraction. Anaesthesia was induced rapidly and smoothly by inhalation of sevoflurane. We discussed the advantages of sevoflurane as an induction agent as compared to halothane in these children.

Effect of rocuronium compared with succinylcholine on intraocular pressure during rapid sequence induction of anaesthesia

We have compared the effect of rocuronium and succinylcholine on intraocular pressure (IOP) during rapid sequence induction of anaesthesia using propofol and fentanyl, in a randomized double-blind study. We studied 30 adult patients, allocated to one of two groups. Anaesthesia was induced with fentanyl 2 micrograms kg-1 and propofol until loss of verbal response. This was followed by succinylcholine 1.5 mg kg-1 (group S; n = 15) or rocuronium 0.9 mg kg-1 (group R; n = 15). Laryngoscopy was performed 60 s later. IOP, mean arterial pressure (MAP) and heart rate (HR) were measured before induction, immediately before intubation and every minute after intubation for 5 min. A Keeler Pulsair air impulse tonometer was used to measure IOP and the mean of two readings obtained in the right eye at each measurement time was recorded. Intubating conditions were evaluated according to a simple scoring system. IOP in the succinylcholine group was significantly greater than that in the rocuronium group (mean 21.6 (SEM 1.4) mm Hg vs 13.3 (1.4) mm Hg; P < 0.001). Intubating conditions were equally good in both groups. We conclude that with rapid sequence induction of anaesthesia using propofol and fentanyl, rocuronium did not cause as great an increase in IOP as succinylcholine and may be an alternative in open eye injury cases.

The effect of mivacurium pretreatment on intra-ocular pressure changes induced by suxamethonium

Forty patients without eye disease, undergoing elective nonophthalmic surgery, were studied in a double-blind, randomised, placebo-controlled study evaluating the efficacy of mivacurium pretreatment in attenuating the rise in intra-ocular pressure in response to suxamethonium administration, laryngoscopy and intubation. The patients were randomly allocated to receive either mivacurium 0.02 mg.kg-1 or normal saline as pretreatment 3 min before a rapid sequence induction technique using alfentanil, propofol and suxamethonium. Suxamethonium induced a significant increase in intra-ocular pressure in the control group but not in the mivacurium pretreatment group (mean (SEM) increase = 3.5 (1.2) mmHg vs. 0.4 (0.8) mmHg, p < 0.05). There was a decrease in intra-ocular pressure in both groups after laryngoscopy and intubation with no significant difference between the two groups. These results show that mivacurium pretreatment is effective in preventing the increase in intra-ocular pressure after suxamethonium administration.

Endotracheal tube ignition during CO2 laser surgery of the larynx

We report a case of endotracheal tube fire occurring during CO2 laser surgery of the larynx. The ignition of an endotracheal tube was thought to be caused by laser penetration of an unprotected portion of the tube during resection of vocal cord tumour. Fire hazard is inevitable when a laser is used in the path of combustible gases and in the presence of flammable objects. We discuss the methods of prevention that were used.

Correlated light scattering by a dense distribution of condensation droplets on a window pane

An analytical model of the scattering structure factor for an assembly of noninteracting hard disks has recently appeared in the literature [Phys. Rev. A 42, 5978-5989 (1990)]. We employ this model to calculate correlated light scattering by monodispersions and binary mixtures of condensation droplets on a window pane. We find that an area fraction of ƒ ≥ 0.6 is required for producing the near-forward direction scattering suppression and that a moderately wide polydispersion of droplet sizes is capable of producing the experimentally observed bright ring of colored light.

Individualized computer tomography of the skull with the EMI scanner using the 160 X 160 matrix

The individualized approach to the performance of computerized tomography of the skull is described. With the use of the 160X160 matrix it is possible to look at the initial scans almost immediately after their completion. If necessary, unsatisfactory scans can be repeated, the position of the head can be changed and artifacts due to motion can be minimized or eliminated. Lesions can be revealed or enhanced with intravenously injected contrast material if desired. The individualized approach has eliminated the need to recall patients and has improved the diagnostic capability of the method.

Coronary angiographic and scintigraphic findings in experimental cardiac contusion

Clinical, angiographic, scintigraphic and pathologic observations in myocardial contusion were correlated. Radionuclide imaging of the injured heart with 99mTc-Sn-polyphosphate provides an accurate diagnosis in acute, even mild, myocardial contusion. The study can be carried out without danger to the critically ill patient. The coronary angiographic findings in this study explain what is occurring pathologically in the heart. Since arteriography is a more invasive technique than radionuclide imaging, its use is recommended only when the image is negative if it is neccessary to establish the clinical diagnosis for treatment or when more than one week has elapsed since the injury.

A new method of diagnosing myocardial contusion in man by radionuclide imaging

A new method of diagnosing myocardial contusion was studied in 8 patients in whom the injured mycardium was visualized as an abnormal area of increased activity in the region of the heart one hour after intravenous injection of 10 mCi of 99m-Tc-Sn-polyphosphate or pyrophosphate. Serum enzymes in these patients were elevated, but electrocardiograms were nonspecific for myocardial injury. It is hoped that this new technique of imaging the injured myocardium will provide specific and confirmatory diagnosis of myocardial contusion associated with closed chest injuries.

Cardiac trauma: Clinical and experimental correlations of myocardial contusion

Clinical and experimental observations in myocardial contusion have been correlated. Cardiac arrhythmia is always an important consequence and may be fatal. Reduction in cardiac output often accompanies significant cardiac injury. The coronary arterial circulation is not interrupted and is generally enhanced to the area of injury. Healing of the injury under these circulatory conditions may result in patchy scarring and peculiar adynamic areas of myocardium. Early diagnosis of myocardial contusion may be aided using radionuclide imaging with (99m)Tc-Sn-polyphosphate.