Dentine hypersensitivity - Australian dentists' perspective

BACKGROUND

Dentine hypersensitivity is a frequent clinical presentation though inadequately comprehended by dentists. The objective of this study was to describe Australian dentists' perception on the occurrence, predisposing factors, triggers, diagnosis and management of dentine hypersensitivity.

METHODS

Eight hundred dentists were randomly selected using the Australian Dental Association membership list and invited to participate in a questionnaire-based survey.

RESULTS

Out of 295 responding dentists, 284 private practitioners were included in the final analysis. Most dentists perceived that the occurrence of dentine hypersensitivity was <20% and commonest among 30-49 year olds. According to them, abrasion and gingival recession were the main predisposing factors whilst cold stimuli were the commonest trigger. A differential diagnosis-based approach was adopted by a majority to diagnose dentine hypersensitivity although routine screening was resorted to by a few. Most dentists were aware of the current mechanisms underlying dentine hypersensitivity whereas the majority perceived that ongoing predisposing factors was the main reason for dentine tubules to remain exposed. The commonest management strategy employed by most dentists was to prescribe desensitizing agents for home use.

CONCLUSIONS

Australian dentists' perception of dentine hypersensitivity is generally consistent with the current scientific consensus on this subject.

Recombinant varicella vaccines induce neutralizing antibodies and cellular immune responses to SIV and reduce viral loads in immunized rhesus macaques

The development of an effective AIDS vaccine remains one of the highest priorities in HIV research. The live, attenuated varicella-zoster virus (VZV) Oka vaccine, safe and effective for prevention of chickenpox and zoster, also has potential as a recombinant vaccine against other pathogens, including human immunodeficiency virus (HIV). The simian varicella model, utilizing simian varicella virus (SVV), offers an approach to evaluate recombinant varicella vaccine candidates. Recombinant SVV (rSVV) vaccine viruses expressing simian immunodeficiency virus (SIV) env and gag antigens were constructed. The hypothesis tested was that a live, attenuated rSVV-SIV vaccine will induce immune responses against SIV in the rhesus macaques and provide protection against SIV challenge. The results demonstrated that rSVV-SIV vaccination induced low levels of neutralizing antibodies and cellular immune responses to SIV in immunized rhesus macaques and significantly reduced viral loads following intravenous challenge with pathogenic SIVmac251-CX-1.

Effect and mechanism of andrographolide on the recovery of Pseudomonas aeruginosa susceptibility to several antibiotics

Effectiveness and mechanism of action of andrographolide on the recovery of Pseudomonas aeruginosa susceptibility to antibiotics was investigated. In the presence of andrographolide, the Mueller-Hinton broth dilution method measured minimal inhibitory concentrations (MIC) of ceftazidine, cefpirome, chloramphenicol, L-ofloxacin, kanamycin, imipenem and meropenem. Real-time fluorescence quantitative polymerase chain reaction was used to determine mexB mRNA expressions in P. aeruginosa PAO1 strain and MexAB-OprM overexpressing strain. Relative mexB mRNA expression was detected in both strains incubated for 3 and 9 h. When andrographolide-treated groups were compared with controls, the MIC of ceftazidine, cefpirome, L-ofloxacin and meropenem for both strains decreased, and the relative mexB mRNA expression was significantly lower, although between andrographolide groups there were no significant differences. Compared with the inactivated quorum-sensing system, relative amounts of mexB mRNA in the PAO1 strain and MexAB-OprM overexpressing strain in the activated quorum-sensing system increased 10- and 30-fold, respectively. Andrographolide recovered P. aeruginosa susceptibility to antibiotics and reduced the MexAB-OprM efflux pump expression level.

Species dependent expression of intestinal smooth muscle mechanosensitive sodium channels

A mechanosensitive Na(+) current carried by Na(v)1.5 is present in human intestinal circular smooth muscle and contributes to regulation of intestinal motor function. Expression of this channel in different species is unknown. Our aim was to determine if Na(+) currents and message for the alpha subunit of the Na(+) channel (SCN5A) are found in circular smooth muscle cells of human, dog, pig, mouse and guinea pig jejunum. Currents were recorded using patch clamp techniques. Message for SCN5A was investigated using laser capture microdissection and reverse transcription polymerase chain reaction (RT-PCR). Na(+) currents were identified consistently in human and dog smooth muscle cells; however, Na(+) current was not found in pig (0/20) or guinea pig smooth muscle cells (0/21) and found only one mouse cell (1/21). SCN5A mRNA was found in circular muscle of human, dog, and mouse, but not in pig or guinea pig, and not in mouse longitudinal or mucosal layers. In summary, SCN5A message is expressed in, and Na(+) current recorded from, circular muscle layer of human and dog but not from pig and guinea pig. These data show that there are species differences in expression of the SCN5A-encoded Na(v)1.5 channel, suggesting species-specific differences in the electrophysiological response to mechanical and depolarizing stimuli.

Simian varicella virus gene 61 encodes a viral transactivator but is non-essential for in vitro replication

Simian varicella virus (SVV) is closely related to varicella-zoster virus (VZV), the causative agent of chickenpox and shingles. The SVV and VZV gene 61 polypeptides are homologs of the HSV-1 ICP0, a viral transactivator which appears to play a role in viral latency and reactivation. In this study, the molecular properties of the SVV 61 were characterized. The SVV open reading frame (ORF) 61 encodes a 54.1-kDa polypeptide with 37% amino acid identity to the VZV 61. Homology to the HSV-1 ICP-0 is limited to a conserved RING finger motif at the amino terminus of the protein. A nuclear localization sequence (nls) at the carboxy-terminus directs the SVV 61 to the cell nucleus, while a SVV 61nls(-) mutant is confined to the cell cytoplasm. The SVV 61 transactivates its own promoter as well as SVV immediate early (IE, ORF 62), early (ORFs 28 and 29), and late (ORF 68) gene promoters in transfected Vero cells. The RING finger and nls motifs are required for efficient SVV 61 transactivation. The SVV 61 has no effect on the ability of the major SVV transactivator (IE62) to induce SVV promoters. Generation and propagation of a SVV gene 61 deletion mutant demonstrated that the SVV 61 is non-essential for in vitro replication. SVV gene 61 is expressed in liver, lung, and neural ganglia of infected monkeys during acute simian varicella.

The nuclear pore complex protein Tpr is a common autoantigen in sera that demonstrate nuclear envelope staining by indirect immunofluorescence

We studied the autoantigen targets of 75 human sera that had antibodies to the nuclear envelope (NE) as identified by indirect immunofluorescence (IIF) on HEp-2 cells. Several different IIF staining patterns could be identified when antibodies to different components of the nuclear membrane (NM) and nuclear pore complexes (NuPC) were identified: a smooth membrane pattern characteristic of antibodies to nuclear lamins, a punctate pattern typical of antibodies to the nuclear pore complex and more complex patterns that included antibodies to nuclear and cytoplasmic organelles. Western immunoblotting of isolated nuclear and NE proteins and immunoprecipitation of radiolabelled recombinant proteins prepared by using the full-length cDNAs of the Translocated promoter region (Tpr), gp210 and p62 were used to identify specific autoantibody targets. Fifty-two of the 75 (70%) sera bound to Tpr, 25 (33%) bound to lamins A, B or C, 15 (20%) reacted with gp210 and none reacted with p62. Sixteen (21%) did not react with any of the NE components tested in our assays. The clinical features of 37 patients with anti-NE showed that there were 34 females and three males with an age range of 16-88 years (mean 59 years). The most frequent clinical diagnosis (9/37 = 24%) was autoimmune liver disease (ALD; two with primary biliary cirrhosis), followed by seven (19%) with systemic lupus erythematosus (SLE), four (11%) with a motor and/or sensory neuropathy, three (8%) with anti-phospholipid syndrome (APS), two with systemic sclerosis (SSc), two with Sjögren's syndrome (SjS), and others with a variety of diagnoses. This report indicates that Tpr, a component of the NuPC, is a common target of human autoantibodies that react with the NE.

Autoantigens of the nuclear pore complex

The nuclear envelope (NE) is one of many intracellular targets of the autoimmune response in patients with autoimmune liver disease, systemic lupus erythematosus, and related conditions. In eukaryotic organisms the NE consists of five interconnected regions: an outer nuclear membrane (ONM) that is continuous with the endoplasmic reticulum, an intermembrane or perinuclear space, an inner nuclear membrane (INM) with a unique set of integral membrane proteins, the underlying nuclear lamina, and the pore domains that are regions where the ONM and INM come together. The pore domains are sites of regulated continuity between the cytoplasm and nucleus that are occupied by supramolecular structures, termed nuclear pore complexes (NPCs). Human autoantibodies identified to date bind to specific components in three of the five NE compartments. Autoantigen targets include the lamins A, B, and C of the nuclear lamina, gp210, p62 complex proteins, Nup153, and Tpr within the NPC, and LBR, MAN1, LAP1, and LAP2 that are integral proteins of the INM. Autoantibodies to these NE targets have been shown to be correlated with various autoimmune diseases such as primary biliary cirrhosis, other autoimmune liver diseases and systemic rheumatic diseases. Now that the proteome of the NE is more clearly defined, other autoantibodies to components in this cell compartment are likely to be defined.

Paraneoplastic limbic encephalitis masquerading as chronic behavioural disturbance in an adolescent girl

AIM

To describe an unusual but treatable cause of behavioural disturbance in adolescence.

METHODS

The case is reported of a 15-y-old girl presenting with acute confusion, memory problems and psychotic symptoms following an 18-mo history of change in personality, school failure and running away from home. A review of the literature is also presented.

RESULTS

Microbiology, toxicology, computed tomography and magnetic resonance imaging did not show any pathology of the central nervous system. Bilateral ovarian immature teratomas were eventually diagnosed and removed. The rapid improvement in the patient's mental and cognitive functions after corticosteroid treatment and the abnormality shown on the single photon emission computed tomography suggested a diagnosis of paraneoplastic limbic encephalitis.

CONCLUSION

Paediatricians and neurologists should be aware of this rare disease entity among the more common conditions of behavioural problems and substance abuse in adolescents.

SCN5A is expressed in human jejunal circular smooth muscle cells

Tetrodotoxin-resistant Na+currents are expressed in a variety of muscle cells including human jejunal circular smooth muscle (HJCSM) cells. The aim of this study was to determine the molecular identity of the pore-forming alpha-subunit of the HJCSM Na+ channel. Degenerate primers identified a cDNA fragment of 1.5 kb with 99% nucleotide homology with human cardiac SCN5A. The identified clone was also amplified from single smooth muscle cells by reverse transcriptase-polymerase chain reaction (RT-PCR). Northern blot analysis showed expression of full-length SCN5A. Laser capture microdissection was used to obtain highly purified populations of HJCSM cells. RT-PCR on the harvested cells showed that SCN5A was present in circular but not in longitudinal muscle. A similar result was obtained using a pan-Na+ channel antibody. The full-length sequence for SCN5A was obtained by combining standard polymerase chain reaction with 5' and 3' rapid amplification of cDNA end techniques. The intestinal SCN5A was nearly identical to the cardiac SCN5A. The data indicate that SCN5A is more widely distributed than previously thought and encodes the pore-forming alpha-subunit of the tetrodotoxin-resistant Na+ current in HJCSM cells.

Non-accidental carbon monoxide poisoning from burning charcoal in attempted combined homicide-suicide

OBJECTIVE

To describe an emerging form of serious child abuse in combined homicide-suicide in Hong Kong.

METHOD

This is a retrospective hospital chart review in a regional hospital in Hong Kong from January to December 2000.

RESULTS

Eight children, with a mean age of 7.8 years (range 0.5-11 years), from four families were admitted to hospital because of non-accidental exposure to carbon monoxide when their parents attempted suicide by burning charcoal. A 7-year-old boy died on arrival. His 5.6-year-old sister and another 6-month-old boy had cerebral hypoxia on admission. Hyperbaric oxygen therapy was used in both cases, with rapid improvement, although there were persistent neurological deficits in the girl. The other children in the present study were asymptomatic and none had delayed neurological sequelae. Concomitant use of sedatives was also detected in three of the surviving patients.

CONCLUSIONS

Non-accidental poisoning with carbon monoxide appears to be a new means of child abuse with potentially serious consequences. Concomitant intoxication with psychotropic drugs is common in such cases. The reason for parents killing their own children under such circumstances was unclear, but a desire to exact revenge on an estranged partner was suggested.

[Experimental study of interleukin-12 gene vaccines in the treatment of low-load malignant lymphoma (EL4)]

OBJECTIVE

Two kinds of murine interleukin-12 (mIL-12) fusion gene vaccines were used to treat the murine low-load malignant T cell lymphoma EL4 as minimal residual disease (MRD) model.

METHODS

C57BL/6 synergistical mice were subcutaneously inoculated with 1 x 10(6) wild-type (wt) EL4 tumor cells as low-load lymphoma model treated with two mIL-12 gene vaccines. Package cell line PA317/12 producing mIL-12 retrovirus (RV) was used as in vivo vaccine and EL4 tumor cells transferred with mIL-12 gene as ex vivo vaccine.

RESULTS

In both mIL-12 gene vaccine-treated groups, there was no tumor growth in 50% mice 60 days after inoculation. Nine of these no tumor growth mice were re-challenged with 5 x 10(5) wt EL4 cells, and 5 of them survived without tumors in another 60 days. All control mice died with tumors within one month after inoculation. Among those developed tumors in both vaccine-treated groups, the development of tumors was delayed, the survival period prolonged (P < 0.01), and the tumors size at death smaller (P < 0.05) as compared with the controls. In the long-survived vaccine-treated mice, no residual tumor cells were found by morphological examination.

CONCLUSION

Both IL-12 gene vaccines can efficiently eliminate wt EL4 MRD in C57BL/6 mice.

[Clinical analysis of 62 cases laryngeal papilloma in children]

OBJECTIVE

To investigate the clinical features of laryngeal papilloma in children.

METHOD

In a group of 62 patients with laryngeal papilloma in children, the tumors of 28 patients were cut under the direct laryngoscope, 34 patients were treated with laryngeal micro-laser operation.

RESULT

The post-operation followup ranged from 2 to 5 years, the cure rate of 2 years was 51.61%.

CONCLUSION

The clinical features of this disease include rapid development, a large lesion, and it is often found in the infraglottic cavity. Furthermore, we believe that in order to eliminate the tumors more accurately and decrease recurrence, micro-laser surgery and the use of interferon is very necessary.

[Correlation of the metabolism of oxygen free radical in ovary, uterine muscle and vein blood with the pathogenesis of endometriosis or endometrioma]

OBJECTIVE

To investigate the correlation of metabolism disturbance of oxygen free radical (OFR) with endometriosis and endometrioma, to provide an evidence for the diagnosis and treatment.

METHODS

(1) The lipid peroxide (LPO), selenium (Se), superoxide dismutase (SOD) and vitamin E (VE) levels were respectively in the vein blood, ovary tissue of the chocolate cyst wall and chocolate cyst fluid in 32 operated patients with endometriosis (endometriosis group). (2) The levels above were determined separately in 23 operated patients with endometrioma (endometrioma group) and 30 cases of hysteroma (control group).

RESULTS

(1) The LPO levels in vein blood and ovary tissue of endometriosis group were (6.357 +/- 1.251) mumol/L and (3.735 +/- 1.546) nmol/g protein. Which significantly higher than those of control group (P < 0.01). On the other hand, the Se. SOD. VE levels in endometriosis group were significantly lower than those in control group (P < 0.01-< 0.05). (2) The LPO level in ovary chocolate cyst fluid was higher than that in vein blood itself and control group. (P < 0.01). (3) The LPO levels in vein blood and uterine muscle of endometrioma was (5.882 +/- 1.711) mumol/L and (2.937 +/- 1.577) nmol/g protein, they were higher-than these in control group (3.547 +/- 1.640) mumol/L, (1.754 +/- 0.833) nmol/g protein, (P < 0.01). While, the Se. VE. SOD level tween the SOD level in uterine muscle tissue of endometriomin vein blood is significantly higher than those in control group (P < 0.01). There is no difference bea and control group (P > 0.05).

CONCLUSION

The endome triosis and endometrioma is related to the produce or metabolistic imbalance of oxygen free radical, and so to the increasing of lipid peroxide.

SeO(2) induces apoptosis with down-regulation of Bcl-2 and up-regulation of P53 expression in both immortal human hepatic cell line and hepatoma cell line

An immortal human hepatic cell line HL-7702 and human hepatoma cell line SMMC-7721 were treated with 3-30 microM SeO(2). SeO(2) at 30 microM markedly inhibited cell proliferation and viability, and prompted apoptosis of both normal hepatic and hepatoma cells after 48h treatment. SeO(2) could also down-regulate the Bcl-2 level, greatly in HL-7702 and slightly in SMMC-7721 cells, but up-regulate wild type P53 level a little in HL-7702 and significantly in SMMC-7721 cells. The Bcl-2/P53 value was closely correlated with the apoptotic rate as well as SeO(2) concentrations.