Psychogenic coma after dental surgery under general anaesthesia.

Delayed awakening after general anaesthesia due to psychogenic coma is a phenomenon that rarely presents to the oral and maxillofacial surgeon. A case of psychogenic coma following general anaesthesia for dental extractions is presented here. It is recommended that patients at risk of conversion disorder should be counselled about the risks of psychogenic coma. Early diagnosis of this condition could lead to better patient management.

A comparison of dabigatran and warfarin for stroke prevention in elderly Asian population with nonvalvular atrial fibrillation: An audit of current practice in Malaysia.

INTRODUCTION: Atrial fibrillation (AF) is the most common cardiac arrhythmia with significant morbidity and mortality in relation to thromboembolic stroke. Our study aimed to evaluate the safety and efficacy of dabigatran in stroke prevention in elderly patient with nonvalvular AF with regard to the risk of ischemic stroke and intracranial haemorrhage (ICH) in real-world setting. METHODS: A retrospective cohort study of 200 patients on dabigatran and warfarin from January 2009 till September 2016 was carried out. Data were collected for 100 patients on dabigatran and 100 patients on warfarin. RESULTS: The mean follow-up period was 340.7±322.3 days for dabigatran group and 410.5±321.2 days for warfarin group. The mean time in therapeutic range (TTR) was 52±18.7%. The mean CHA2DS2 -VASc score for dabigatran group was 4.4±1.1 while 5.0±1.5 for warfarin group. None in dabigatran group experienced ischemic stroke compared to one patient in warfarin group (p=0.316). There was one patient in dabigatran group suffered from ICH compared to none in warfarin group (p=0.316). Four patients in warfarin group experienced minor bleeding, while none from dabigatran group (p=0.043). CONCLUSION: Overall bleeding events were significantly lower in dabigatran group compared to warfarin group. In the presence of suboptimal TTR rates and inconveniences with warfarin therapy, non-vitamin-K antagonist oral anticoagulants (NOAC) are the preferred agents for stroke prevention in elderly Asian patients for nonvalvular AF.

Management and Clinical Outcome of Children with Transfusion-Dependent Thalassaemia in Hospital Tuanku Ja'afar Seremban.

The aim of this study was to evaluate the management and clinical outcome of transfusion-dependent thalassaemia children receiving care in the Paediatric Ambulatory Care Centre, Hospital Tuanku Ja'afar Seremban in comparison to The Malaysian Clinical Practice Guidelines. The demography, management and clinical outcome of the patients were documented using a checklist. Information on compliance to chelation agents was obtained through interview. There were twenty-six patients recruited in this study out of thirty seven patients registered in the centre. This study showed that more effort and vigilance should be given to ensure that the management of these patients adheres to the guidelines and clinical outcome of these patients monitored closely.

Management and Clinical Outcome of Children with Transfusion-Dependent Thalassaemia in Hospital Tuanku Ja'afar Seremban

The aim of this study was to evaluate the management and clinical outcome of transfusion-dependent thalassaemia children receiving care in the Paediatric Ambulatory Care Centre, Hospital Tuanku Ja'afar Seremban in comparison to The Malaysian Clinical Practice Guidelines. The demography, management and clinical outcome of the patients were documented using a checklist. Information on compliance to chelation agents was obtained through interview. There were twenty-six patients recruited in this study out of thirty seven patients registered in the centre. This study showed that more effort and vigilance should be given to ensure that the management of these patients adheres to the guidelines and clinical outcome of these patients monitored closely.

Are Indians and females less tolerant to pain? An observational study using a laboratory pain model.

In Malaysia, it is a common belief among health care workers that females and Indians have lower pain threshold. This experience, although based on anecdotal experience in the healthcare setting, does not allow differentiation between pain tolerance, and pain expression. To determine whether there is a difference in the tolerance to pain between the three main ethnic groups, namely the Malays, Chinese and Indians as well as between males and females. This was a prospective study, using a laboratory pain model (ischaemic pain tolerance) to determine the pain tolerance of 152 IMU medical students. The mean age of the students was 21.8 years (range 18-29 years). All of them were unmarried. The median of ischaemic pain tolerance for Malays, Chinese and Indians were 639s, 695s and 613s respectively (p = 0.779). However, statistically significant difference in ischaemic pain tolerance for males and females Indian students were observed. Possible ethnic difference in pain tolerance in casual observation is not verified by this laboratory pain model. Difference in pain tolerance between genders is shown only for Indians.

Finishing/polishing of composite and compomer restoratives: effectiveness of one-step systems.

This study investigated the surface texture of composite (Z100, 3M ESPE) and compomer (F2000, 3M ESPE) restoratives after treatment with different one-step finishing/polishing systems (One-Gloss [OG], Shofu; PoGo [PG], Dentsply; Sof-Lex Brush [SB], 3M ESPE). The surface roughness obtained was compared to that using a matrix strip [MS], a two-step rubber abrasive (CompoSite [CS], Shofu) and a graded abrasive disk (Super Snap [SS], Shofu) system. Eight specimens (3-mm long x 3-mm wide x 2-mm deep) of each material were made according to manufacturer's instructions. With exception of the MS group, all groups were roughened with 320 grit grinding paper using a lapping device prior to finishing/polishing with the different systems. The mean surface roughness (microm) was measured with a profilometer. Data was subjected to ANOVA/Scheffe's tests and independent samples t-test at significance level 0.05. Mean Ra ranged from 0.22 to 0.32 microm for Z100 and 0.45 to 0.68 for F2000. For both materials, the smoothest surfaces were obtained with MS. The roughest surfaces were observed after treatment with SS and OG for Z100 and F2000, respectively. The effectiveness of the finishing/polishing systems was material dependent. The surface finish produced by PG and SB was superior or comparable to that obtained with CS, SS and OG.

Surface finish of resin-modified and highly viscous glass ionomer cements produced by new one-step systems.

This study investigated the surface finish of resin-modified (Fuji II LC, GC) and highly viscous (Fuji IX GP Fast, GC) glass ionomer cements after treatment with three one-step finishing/polishing systems (One-Gloss [OG], Shofu; Pogo [PG], Dentsply; Sof-Lex Brush [SB], 3M-ESPE). The surface roughness obtained was compared to that using a matrix strip [MS], a two-step rubber abrasive (CompoSite [CS], Shofu) and a graded abrasive disk (Super Snap [SS], Shofu) system. Eight specimens (3-mm long x 3-mm wide x 2-mm deep) of each material were made for the various treatment groups. With the exception of the MS group, all groups were roughened with 320 grit grinding paper using a lapping device prior to finishing/polishing with the different systems. The mean surface roughness (microm) was measured with a profilometer. Data was subjected to ANOVA/Scheffe's tests at significance level 0.05. Mean Ra ranged from 0.13 to 1.04 microm for Fuji II LC and 0.14 to 0.81 for Fuji IX GP. For both materials, the smoothest surface was obtained with MS and the roughest with OG. Depending on the materials, the surface finish produced by PG and SB was superior or comparable to that obtained with CS and SS. The effectiveness of one-step systems, when used to finish/polish resin-modified and highly viscous glass ionomer cements, is product dependent.

Comparison of surface finish of new aesthetic restorative materials.

This study compared the surface finish of eight different types of aesthetic restorative materials. The materials included resin-modified (Fuji II LC [FL], GC) and highly viscous (Fuji IX GP Fast [FN], GC) glass ionomer cements, a compomer (F2000 [FT], 3M-ESPE), minifilled (Z100 [ZO], 3M-ESPE) and microfilled (A110 [AO], 3M-ESPE) composites and materials based on recently introduced ormocer (Admira [AM], Voco), nanomer (Filtek Supreme Translucent [FST], 3M-ESPE) and nanocluster technology (Filtek Supreme [FS], 3M-ESPE). Sixteen specimens (3-mm long x 3-mm wide x 2-mm deep) of each material were divided into two equal groups. Specimens in Group 1 received no further treatment after polymerization against a matrix strip, while the specimens in Group 2 were roughened with 320 grit grinding paper using a lapping device and were finished/polished with a graded abrasive disk system (Super-Snap, Shofu). The mean roughness (Ra, microm) of materials was determined using a surface profilometry. Data was analyzed by ANOVA/Scheffe's test at significance level 0.05. Mean Ra values ranged from 0.04 to 0.16 microm for Group 1 specimens and 0.15 to 0.68 microm for Group 2 specimens. Results of statistical analysis were as follows: Group 1-FS, FST, FL, FN, AM > FT, AO, ZO; Group 2-FN, FT, FL > AO, FS, ZO, AM, FST (> indicates significantly greater Ra values). For the finished/polished composite materials, Ra values observed for AM and FST were significantly lower than for AO and FS. The surface finish of glass ionomers and compomer was significantly poorer than composites. Composite materials based on ormocer and nanomer technology were significantly smoother than those based on microfillers and nanoclusters.

Microwave drying of high strength dental stone: effects on dimensional accuracy.

High-strength dental stone is widely used to produce dies for the fabrication of restorations with the lost-wax technique. It is normal to wait at least 24 hours for casts to dry and gain sufficient strength prior to initiating laboratory procedures. This waiting time may be greatly reduced by using microwave drying. This study determined the optimum microwave energy density for preserving working die accuracy of a Type IV high-strength dental stone (Silky Rock; Whipmix). Cylindrical die specimens were fabricated according to manufacturer's instructions and allowed to set for one hour. The specimens were subsequently treated as follows: Group I (Control group)--air dried; Group II--microwaved at 700W for 40 seconds; Group III--microwaved at 490W for 60 seconds. The percentage weight loss of cylindrical specimens (n = 6) and the percentage dimensional change (n = 7) of die specimens in three axes (x, y and z) were determined at 30 minutes, 1 hour and 24 hours after air drying/microwaving. Weight loss was measured using an electronic digital balance, while dimensional changes were assessed using image analysis software. Data was subject to ANOVA/Scheffe's tests at significance level 0.05. No significant difference in percentage weight loss was observed between air drying for 24 hours and microwaved specimens at all time intervals. Although no significant difference in percentage dimensional changes was observed between specimens microwaved at 490W for 60 seconds and specimens air dried for 24 hours, significant changes in x, y and z dimensions were observed after microwaving at 700W for 40 seconds at various time intervals. Microwave radiation at 490W for 60 seconds is recommended for drying Type IV high-strength dental stone. Further investigations are required to determine changes in physical properties associated with the aforementioned microwave power density.

Avoiding painful blood sampling in neonates by transcutaneous bilirubinometry.

BACKGROUND: Transcutaneous bilirubinometry, Bilicheck (kindly provided by Oxygen Care Company, Dublin) is a non-invasive, screening method for determining bilirubin levels in neonates. It has not previously been validated in Irish babies. AIMS: To determine the clinical accuracy and precision of Bilicheck measurements in comparison to total serum bilirubin (TSB) measurements in Irish neonates, and to determine whether Bilicheck is a useful non-invasive screening method of avoiding blood tests in neonates. METHODS: Correlation data were obtained from 53 neonates between simultaneous TSB and Bilicheck readings. Bilicheck was used to screen 100 neonates who were assessed as requiring serum bilirubin measurement. TSB was only performed on neonates whose Bilicheck was above the phototherapy line of a recognised serum bilirubin chart. RESULTS: Bilicheck and TSB were significantly correlated (r=0.890). Bland and Altman analysis showed that on average, Bilicheck read 30 micromol/l lower than TSB. Of 100 jaundiced neonates screened by Bilicheck, blood sampling was avoided in 70 because Bilicheck did not meet phototherapy guidelines. CONCLUSIONS: There is a good correlation between TSB and Bilicheck, although the latter tends to under-read by 30 micromol/l. Bilicheck may be a useful screening device to decrease the risks and discomfort associated with blood sampling in neonates.

HVR1 quasispecies analysis from a long-term culture of hepatitis C virus in Hep G2 derived cells grown in a haemodialysis cartridge.

Studies on the in vitro hepatitis C virus (HCV) infection are hampered by the lack of an appropriate system to culture permissive cells to be continuously infected with HCV. Trypsinization required for cell passage can lead to possible temporary loss of permissiveness for infection, whereas refreshment of the medium can result in loss of infectious particles necessary for perpetuation of the infection; it is therefore very difficult to maintain a continuous HCV infection in cell cultures. A new infection method was designed and evaluated in order to prevent these unfavourable circumstances. A cell line derived from the human hepatoblastoma cell line Hep G2 was grown in the extracapillary space of a haemodialysis cartridge, in the presence of a HCV-positive inoculum, while the culture medium was recirculated through the intracapillary space, supplying the cells with nutrients and oxygen. HCV RNA could continuously be detected in the cells up to 77 days of culture. Sequence analysis of the HCV hypervariable region 1 (HVR1) revealed that 56% and 75%, respectively, of the clones obtained from the cells at day 20 and 40 after start of the infection were different from the clones obtained from the original inoculum and that certain nucleotide positions in this region were more susceptible to mutations, leading to an alteration in amino acid sequence. As none of these sequences were present in the clones from the inoculum, it is suggested that new HCV quasispecies have emerged as a result of viral replication in the hepatocytes in vitro. This system seems a valuable tool for the in vitro evaluation of antiviral drugs.

An improved model of acute liver failure based on transient ischemia of the liver.

HYPOTHESIS: A reproducible and potentially reversible model of acute liver failure in the pig is feasible based on transient ischemia of the liver. DESIGN: To determine the shortest period of liver ischemia sufficient to cause 100% mortality, ischemia of the liver was induced for different lengths of time, starting with 6 hours. If the pig survived, ischemia time was prolonged for 2 hours in the next animal. In the first group, the common bile duct was not tightened. In the second group, the common bile duct was tightened. SETTING: The Laboratory for Hepatopathophysiology, Catholic University, Leuven, Belgium. PARTICIPANTS: Female stress-negative Belgian Landrace pigs weighing 18 to 22 kg. INTERVENTIONS: During preparatory surgery, all ligaments around the liver and connective tissue around the liver hilum were transected and an end-to-side portacaval shunt was made. Vessel loops were placed around the branches of the hepatic artery and bile duct. Three days later, in fully awake pigs, the loops were tightened. MAIN OUTCOME MEASURES: Mortality. Development of acute liver failure was determined based on neurologic, biochemical, and pathological variables. RESULTS: When occluded for 10 hours, all pigs in group 2 (n = 5) [corrected] died between 12 and 17 hours after the induction of ischemia. All pigs developed typical acute liver failure. Tissue specimens showed 90% necrosis of the liver parenchyma. CONCLUSION: A highly reproducible and potentially reversible model of acute liver failure in the large animal has been established.

Influence of the administration of human annexin V on in vitro binding of small hepatitis B surface antigen to human and to rat hepatocytes and on in vitro hepatitis B virus infection.

Previously, we have determined that human annexin V (hAV), a Ca2+-dependent phospholipid-binding protein, and not rat AV, binds specifically to small hepatitis B surface antigen (SHBsAg), and that transfection of a rat hepatoma cell line with a construct containing the hAV gene led to hAV expression and conferred susceptibility to hepatitis B virus (HBV) infection. In this work, we have examined the effect of administration of hAV on in vitro binding of SHBsAg to human and to rat hepatocytes and on in vitro HBV infection. The results showed that hAV could bind to human as well as to rat hepatocytes. Because of this property, excess hAV was unable to prevent HBV infection in primary cultures of human hepatocytes. On the other hand, it enabled rat hepatocytes to specifically bind SHBsAg and conferred susceptibility to HBV infection. After infection of primary cultures of rat hepatocytes in the presence of hAV, HBV mRNA, covalently closed circular (ccc) DNA, replicative intermediates, hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg) and secreted HBV DNA were detected. After infection in the absence of hAV, no markers of HBV replication were detected. Hence, from the present study we conclude that hAV is involved in facilitating HBV entry, leading to successful HBV infection in primary cultures of rat hepatocytes, while it is not effective in preventing HBV infection in primary cultures of human hepatocytes.

Equally potent inhibitors of cholesterol synthesis in human hepatocytes have distinguishable effects on different cytochrome P450 enzymes.

Six 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (the present cholesterol-lowering drugs known as statins), lovastatin (L), simvastatin (S), pravastatin (P), fluvastatin (F), atorvastatin (A) and cerivastatin (C) are shown to be potent inhibitors of cholesterol synthesis in human hepatocytes, the target tissue for these drugs in man. All six inhibited in the nM range (IC(50) values: 0.2-8.0 nM). As daily used cholesterol-lowering drugs they are likely coadministered with other drugs. While several cytochrome P450 (CYP) enzymes are involved in drug metabolism in the liver and thus play an important role in drug-drug interaction it was investigated which of these enzymes are influenced by the active forms of the six statins. These enzyme activities were studied in human liver microsomal preparations, and in simian and human hepatocytes in primary culture. The following CYP reactions were used: nifedipine aromatization (CYP3A4), testosterone 6beta-hydroxylation (CYP3A4), tolbutamide methylhydroxylation (CYP2C9), S-mephenytoin 4-hydroxylation (CYP2C19), bufuralol 1'-hydroxylation (CYP2D6), aniline 4-hydroxylation (CYP2E1), coumarin 7-hydroxylation (CYP2A6) and 7-ethoxyresorufin O-dealkylation (CYP1A1/2). In the human liver microsomes the statins (concentrations up to 400 microM) did not influence the CYP1A1/2 activity and hardly the CYP2A6 and CYP2E1 activities. Except P, the other five statins were stronger inhibitors of the CYP2C19 activity with IC(50) values around 200 microM and the same holds for the effect of A, C and F on the CYP2D6 activity. L and S were weaker inhibitors of the latter enzyme activity, whereas P did not influence both activities. About the same was observed for the statin effect on CYP2C9 activity, except that F was a strong inhibitor of this activity (IC(50) value: 4 microM). Using the assay of testosterone 6beta-hydroxylation the CYP3A4 activity was decreased by L, S and F with IC(50) values of about 200 microM and a little more by C and A (IC(50) around 100 microM). P had hardly an effect on this activity. To a somewhat less extent the same trend was seen when CYP3A4 activity was measured using nifedipine as substrate. The inhibitory effects observed in microsomes were verified in suspension culture of freshly isolated hepatocytes from Cynomolgus monkey (as a readily available model) and of human hepatocytes. In general the same trends were seen as in the human microsomes, except that in some cases the inhibition of the CYP activity was less, possibly by the induction of the particular CYP enzyme by incubation of the cells with a particular statin. F remained a strong inhibitor of CYP2C9 activity in human and monkey hepatocytes. A induced the CYP2C9 in monkey hepatocytes but was an inhibitor of the CYP2C9 in human hepatocytes. A, S, L and C were moderate inhibitors in both cellular systems of CYP3A4. P was not affecting any of the CYP activities in the three systems studied. It is concluded that different CYP enzymes interact with different statins and therefore differences in between these drugs are to be expected when drug-drug interaction is considered.