Antiviral activity of arbidol against influenza A virus, respiratory syncytial virus, rhinovirus, coxsackie virus and adenovirus in vitro and in vivo

Arbidol, ethyl-6-bromo-4-[(dimethylamino)-methyl]-5-hydroxy-1-methyl-2-[(phenylthio)methyl]-in dole-3-carboxylate hydrochloride monohydrate, is an antiviral chemical agent. In this report, we studied the antiviral activity of arbidol against a panel of human respiratory viruses, namely influenza A virus (FLU-A, A/PR/8/34 H1N1), respiratory syncytial virus (RSV), human rhinovirus type 14 (HRV 14), coxsackie virus B3 (CVB3) and adenovirus type 7 (AdV-7) in vitro in cell culture. Arbidol was found to present potent inhibitory activity against enveloped and non-enveloped RNA viruses, including FLU-A, RSV, HRV 14 and CVB3 when added before, during, or after viral infection, with 50% inhibitory concentration (IC50) ranging from 2.7 to 13.8 microg/ml. However, arbidol showed selective antiviral activity against AdV-7, a DNA virus, only when added after infection (therapeutic index (TI) = 5.5). Orally administered arbidol at 50 or 100 mg/kg/day beginning 24 h pre-virus exposure for 6 days significantly reduced mean pulmonary virus yields and the rate of mortality in mice infected with FLU-A (A/PR/8/34 H1N1). Our results suggest that arbidol has the ability to elicit protective broad-spectrum antiviral activity against a number of human pathogenic respiratory viruses.

Fc dependent mechanisms are necessary for ADCC and effective depletion of murine B cells by humanized anti-CD19 mAb. (131.27)

B cell depletion is an effective treatment for autoimmune diseases and B cell malignancies. Successful B cell depletion may be limited by the surface expression of the target antigen. CD19 represents an attractive molecular target that is expressed on the surface of early B cell progenitors through the latter stages of B cell differentiation. In this study we developed a fully humanized CD19 monoclonal antibody mAb 19-1 and two variants with either reduced (19-2) or enhanced (19-3) Fc-FcR binding and evaluated their potential to deplete B cells. In vitro antibody-dependent cellular-mediated cytotoxicity (ADCC) activity of 19-3>19-1>19-2 on human peripheral blood B cells as well as B cell lines (Raji, Daudi, and Ramos) by LDH release or Granzyme B assays. We evaluated in vivo depletion in human CD19 transgenic mice using 19-1, 19-2, and 19-3. 19-1 at 50 ug/mouse i.v. depleted most B cells in blood, spleen, and bone marrow after 7 days following treatment. 19-2 showed little depletion of B cells at a high dose, whereas 19-3 efficiently eliminated B cells in the spleen and blood at low dose. These data demonstrate that transgenic mice expressing human antigens provide an excellent model for testing humanized antibodies in depletion studies, and that Fc-FcR interactions represent the most important mechanism. Targeting B cells with anti-CD19 mAb may be a more effective strategy than existing B cell depletion protocols.

OCT4: biological functions and clinical applications as a marker of germ cell neoplasia

Germ cell tumours (GCTs) are a heterogeneous group of neoplasms, which develop in the gonads as well as in extragonadal sites, that share morphological patterns and an overall good prognosis, owing to their responsiveness to current surgical, chemotherapeutic, and radiotherapeutic measures. GCTs demonstrate extremely interesting biological features because of their close relationships with normal embryonal development as demonstrated by the pluripotentiality of some undifferentiated GCT variants. The similarities between GCTs and normal germ cell development have made it possible to identify possible pathogenetic pathways in neoplastic transformation and progression of GCTs. Genotypic and immunophenotypic profiles of these tumours are also useful in establishing and narrowing the differential diagnosis in cases of suspected GCTs. Recently, OCT4 (also known as OCT3 or POU5F1), a transcription factor that has been recognized as fundamental in the maintenance of pluripotency in embryonic stem cells and primordial germ cells, has been proposed as a useful marker for GCTs that exhibit features of pluripotentiality, specifically seminoma/dysgerminoma/germinoma and embryonal carcinoma. The development of commercially available OCT4-specific antibodies suitable for immunohistochemistry on paraffin-embedded specimens has generated increasing numbers of reports of OCT4 expression in a wide variety of gonadal and extragonadal GCTs. OCT4 immunostaining has been shown to be a sensitive and specific marker for seminomatous/(dys)germinomatous tumours and in embryonal carcinoma variants of non-seminomatous GCTs, whether in primary gonadal or extragonadal sites or in metastatic lesions. Therefore, OCT4 immunohistochemistry is an additional helpful marker both in the differential diagnosis of specific histological subtypes of GCTs and in establishing a germ cell origin for some metastatic tumours of uncertain primary. OCT4 expression has also been reported in pre-invasive conditions such as intratubular germ cell neoplasia, unclassified (IGCNU) and the germ cell component of gonadoblastoma. Additionally, OCT4 immunostaining shows promise as a useful tool in managing patients known to be at high risk for the development of invasive GCTs.

Low relaxation rate in epitaxial vanadium-doped ultrathin iron films

The longest relaxation time and sharpest frequency content in ferromagnetic precession is determined by the intrinsic (Gilbert) relaxation rate G. For many years, pure iron (Fe) has had the lowest known value of G = 57 MHz for all pure ferromagnetic metals or binary alloys. We show that an epitaxial iron alloy with vanadium (V) possesses values of G which are significantly reduced to 35 +/- 5 MHz at 27% V. The result can be understood as the role of spin-orbit coupling in generating relaxation, reduced through the atomic number Z.

Construction of patient specific geometries suitable for the inverse problem of electrocardiography

The ability to accurately construct a geometric representation of the heart and torso is a critical component for electrocardiographic inverse algorithms. Typically geometric models have been constructed using data acquired from imaging modalities such as MRI and CT. We propose a system where the torso surface geometry is obtained using a laser scanning device and the heart geometry is obtained using three-dimensional ultrasound.

Histogenesis of sarcomatoid urothelial carcinoma of the urinary bladder: evidence for a common clonal origin with divergent differentiation

The histogenesis of sarcomatoid urothelial carcinoma, a rare neoplasm with bidirectional epithelial and mesenchymal differentiation, has been a matter of controversy. To clarify its origin, we analysed the status of X-chromosome inactivation in sarcomatoid urothelial carcinomas from 10 female patients and examined losses of heterozygosity (LOH) in these specimens and in additional 20 tumours from male patients. Six polymorphic microsatellite markers where genetic alterations occur frequently in early or advanced stages of urothelial carcinomas, including D3S3050, D8S261, IFNA, D9S177, D11S569 and TP53, were investigated in the current study. The identical pattern of non-random X-chromosome inactivation in both carcinomatous and sarcomatous components was identified in five of eight informative female patients, and the remaining three informative cases showed a random, but concordant, pattern of X-chromosome inactivation. The concordant X-chromosome inactivation results in all eight informative cases support the concept of a monoclonal origin of both components of this biphasic neoplasm. Among the tumours demonstrating loss of heterozygosity, high incidences of an identical pattern of allelic loss between carcinomatous and sarcomatous components were identified in genetic alterations associated with early carcinogenesis: 86% at D8S261, 78% at D11S569, 75% at D9S177 and 57% at IFNA. In contrast, concordant LOH patterns were less frequently observed for microsatellites related to advanced carcinogenesis: only 40% at D3S3050 and 40% at TP53. The significant overlap of loss of heterozygosity supports a monoclonal cell origin and suggests that clonal divergence may occur during tumour progression and differentiation. Divergent patterns of discordant allelic loss of microsatellite markers imply that heterogeneous pathogenetic pathways may exist in the evolution of this enigmatic neoplasm.

Identification of B cell epitopes at the C-terminus of latency-associated nuclear protein of the kaposi's sarcoma-associated herpesvirus

The latency-associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV) plays a key role in the induction of cell transformation, maintenance of viral episome, and modulation of immune response in human. To identify the presence of B cell epitopes within C-terminus of LANA and to characterize the monoclonal antibodies (MAbs) against this protein, we expressed the C-terminal region at aa 794-1000 of LANA (pLANA-C) in Escherichia coli as a fusion protein. KSHV-positive human sera were able to recognize the recombinant LANA-C in the Western blot analysis and ELISA. Mapping of antigenic epitopes of pLANA-C by KSHV-positive human sera revealed two B cell antigenic epitopes located at aa 846-854 and aa 794-822. The MAb 3F11 recognized a region between at aa 840 to 846 of LANA and exhibited a strong and specific binding to both pLANA-C and native viral LANA. These findings showed that pLANA-C and MAb 3F11 could be used for the detection of KSHV antibodies in human sera and for the advanced study of biological functions of LANA.

Effect of lysed Enterococcus faecalis FK-23 on allergen-induced immune responses and intestinal microflora in antibiotic-treated weaning mice

BACKGROUND

Recent epidemiological studies have indicated that early life receipt of antibiotics may be associated with an increased risk of developing atopic disorder. Lysed Enterococcus faecalis FK-23 (LFK), a probiotic product of E faecalis, has been shown to have inhibitory effects on allergen-induced immune responses in mice.

OBJECTIVE

The purpose of this study was to evaluate the effects of LFK on immune responses and intestinal microflora in antibiotic-treated, and allergen-sensitized weaning mice.

METHODS

Three-week-old BALB/c mice were sensitized with cedar pollen allergen to establish the experimental model. The allergen-induced peritoneal accumulation of eosinophils, serum levels of total and allergen-specific immunoglobulin (Ig) E and IgG2a, and the intestinal bacterial flora were determined in the control, antibiotic, LFK and antibiotic-LFK groups (n = 7 in all groups). Orally administered erythromycin, one kind of macrolide antibiotic, was used for the experiments.

RESULTS

There was no significant difference in the allergen-induced peritoneal accumulation of eosinophils and serum specific IgE and IgG2a levels in erythromycin-treated mice compared to a control group. However, the ratio of serum total IgE to IgG2a levels was significantly increased in erythromycin-treated mice relative to that found either in LFK-treated mice or in erythromycin-treated mice with LFK supplementation. The total aerobes, total anaerobes and Enterococcus species of intestinal microflora were not significantly different among all groups. Lactobacillus species were distinctly eliminated in the mice exposed to erythromycin on day 7 and totally recovered in erythromycin-treated mice with LFK intervention on day 28, but could not be recovered in the erythromycin-treated mice without LFK intervention.

CONCLUSIONS

Our results suggest that LFK may improve the intestinal ecosystem disturbed by antibiotic use, and thereby prevent subsequent development of atopy. However, whether different antibiotics have different effects on immune responses needs to be addressed further.

Electronic structures and chemical bonding in 4d transition metal monohalides

Bond distances, vibrational frequencies, dipole moments, dissociation energies, electron affinities, and ionization potentials of MX (XM = Y-Cd, X = F, Cl, Br, I) molecules in neutral, positively, and negatively charged ions were studied by density functional method, B3LYP. The bonding patterns were analyzed and compared with both the available data and across the series. It was found that besides ionic component, covalent bonds are formed between the 4d transition metal s, d orbitals, and the p orbital of halogen. For both neutral and charged molecules, the fluorides have the shortest bond distance, iodides the longest. Although the opposite situation is observed for vibrational frequency, that is, fluorides have the largest value, iodides the smallest. For neutral and anionic species, the dissociation energy tends to decrease with the increasing atomic number from Y to Cd, suggesting the decreasing or weakening of the bond strength. For cationic species, the trend is observed from Y to Ag.

The molecular basis of "curlicue": a sperm motility abnormality linked to the sterility of t haplotype homozygous male mice

The t complex, a variant region of chromatin occupying approximately 40-million base pairs of proximal chromosome 17, exists in natural populations of wild mice of the Mus musculus species as a family of homologues called t haplotypes (t). Relative to wild-type (+) homologues, all t haplotypes share four large non-overlapping inversions, spanning 95% of the region, leading to intra-inversion recombination suppression in +/t heterozygotes. Non-lethal t homozygous males or complementing recessive lethal t doubly heterozygous males (hereafter both abbreviated "t/t males") are invariably and completely sterile, due to expression of several sperm function abnormalities. One of these traits, "curlicue", describes a condition in which spermatozoa from t/t males fail to reach the site of fertilization in vivo because they exhibit a severe loss of vigorous forward motility due to the chronic negative curvature of their flagella. Current data indicate that "curlicue" is the complex phenotypic reflection of the expression of three or more mutations clustered in the distal one-third of the largest and most-distal t complex inversion, In(17)4. From proximal to distal, candidates include Dnahc8, Tsga2 and Tctex5. Interestingly, new results from high-resolution intra-inversion genetic mapping and protein localization studies suggest that the products of the distal two candidates, Tsga2 and Tctex5, might play synergic roles in the expression of both the "curlicue" motility abnormality and the "stop" sperm-egg interaction aberration, regarded as functionally unrelated traits.

Hospital and community surveys reveal the severe public health problem and socio-economic impact of human echinococcosis in Ningxia Hui Autonomous Region, China

A comprehensive study of human echinococcosis (caused by Echinococcus granulosus or E. multilocularis), including assessment of hospital records, community surveys and patient follow-up, was conducted in Ningxia Hui Autonomous Region (NHAR), China. In contrast to hospital records that showed 96% of echinococcosis cases were caused by cystic echinococcosis (CE), 56% of cases detected in active community surveys were caused by alveolar echinococcosis (AE). The AE and CE cases co-existed frequently in the same village, even occurring in the same patient. A serious public health problem caused by echinococcosis was evident in southern NHAR, typified by: a long diagnostic history for both AE and CE (7.5 years) compared with a shorter treatment history (4.7 years); a significant mortality rate (39%) caused by AE in one surveyed village, where patients had no previous access to treatment; family aggregation of CE and AE cases; a high proportion of both AE (62.5%) and CE (58%) in females; a high rate of recurrent surgery (30%) for CE demonstrated by surgical records; and frequent symptomatic recurrences (51%) because of discontinuous or sporadic access to chemotherapy for AE. The disease burden for both human AE and CE is thus very severe among these rural communities in NHAR, and this study provides the first attempt to determine the costs of morbidity and surgical intervention of human CE and AE cases both at the hospital and community level in this setting. This information may be useful for assessing the cost effectiveness of designing effective public health programs to control echinococcosis in this and other endemic areas in China and elsewhere.

Looking for new targets for prostate cancer therapy: Nuclear factor kappa B and CXCR4 co-expression in prostate specimens from RTOG-8610

14578

Background: The transcription factor Nuclear Factor-kappa B (NFκB) promotes the production of angiogenic, anti-apoptotic and prometastatic factors that are involved in carcinogenesis. The chemokine receptor CXCR4, which is under the control of NFκB, has been implicated in regulating metastasis of breast, pancreatic, and prostate cancer. This retrospective cohort study evaluated the frequency and co-expression of NFκB and CXCR4 in human prostate cancer specimens. Methods: Paraffin embedded samples from a subset of patients in the RTOG 8610 trial underwent immunohistochemical staining for NFκB and CXCR4. This study compared radiotherapy plus hormonal therapy to radiation therapy alone. The amount of NFκB and CXCR4 was scored by a blinded pathologist for the percentage of cells stained (0 to 100%) and staining intensity (0 to 3+). Results: NFκB and CXCR4 status was determined for 55 and 63 patients, respectively. Both NFκB and CXCR4 status were available for 51 of these patients. Of these, 51% were 2/3+ for NFκB and 61% were 2/3+ for CXCR4. There was a trend towards correlation between CXCR4 and NFκB staining as 18 of the 36 patients who were 2/3+ positive for NFκB were 2/3+ for CXCR4. 10 of the 11 pts with 3+ NFκB had 2/3+ CXCR4. This was consistent with the understanding that CXCR4 is regulated by NFκB, but did not reach statistical significance (p = 0.1298). Neither NFκB or CXCR4 were statistically significantly prognostic factors in this small subset of patients. Conclusion: NFκB and CXCR4 are expressed in a significant number of patients with organ confined prostate cancer. Neither predicted outcomes in this analysis, which may be due to the small sample size. This data supports the notion that NFκB regulates CXCR4 expression in prostate cancer and that one or both may be potential new targets for therapeutic intervention. Studies in larger prospective studies to determine the utility of NFκB and CXCR4 as predictive biomarkers and/or therapeutic targets is warranted. [Table: see text]

No significant financial relationships to disclose.

Phase I clinical trial results of verteporfin enhanced feeder vessel therapy in subfoveal choroidal neovascularisation in age related macular degeneration

AIMS

To investigate the safety and effectiveness of extrafoveal photodynamic therapy (PDT) occlusion of feeder vessels (FVs) in patients with subfoveal choroidal neovascularisation (CNV) as a result of age related macular degeneration.

METHODS

FVs were identified using dynamic fluorescein and indocyanine green angiography with scanning laser ophthalmoscope. The standard doses of verteporfin and laser wavelength were used. The light dose was escalated by increasing the duration of the light dose so the light regimen was 50 J/cm2 for patients 1 and 2; 100 J/cm2 for patients 3, 4, 5; 125 J/cm2 for patients 6 and 7; and 150 J/cm2 for patients 8 and 9. Patients were examined at weeks 1, 4, and 12.

RESULTS

The mean improvement on EDTRS chart 3 months after treatment was an increase of 2.1 lines (p = 0.07). Closure of the FV was achieved angiographically in three eyes at various light doses, in three eyes the FV was hypoperfused, and in three eyes the vessels were were neither closed nor hypoperfused. At the last follow up all FVs were reperfused. There was no evidence of retinal damage.

CONCLUSION

Verteporfin enhanced FV therapy does not cause subfoveal retinal damage and may have potential to improve central vision in subfoveal CNV caused by exudative macular degeneration. It is not recommended as a monotherapy for CNV.

Toxicity of subretinal ribozyme to the proliferating cell nuclear antigen and 5-fluorouracil in rat eyes

PURPOSE

To investigate the subretinal toxicity profile of the ribozyme to the proliferating cell nuclear antigen (PCNA-Rz) and 5-fluorouracil (5-FU), as well as the highest nontoxic subretinal dose of the mixture of the two agents in rat eyes.

METHODS

Brown-Norway rats received subretinal injections of 1 microg, 10 microg, and 100 microg/microl PCNA-Rz and 0.06 microg/microl, 0.3 microg/microl, and 1.5 microg/microl 5-FU in the right eyes, and the left eyes were injected with H-BSS as control. Each dose was tested on 5 eyes in a 5 microl volume. In a second study, a combination of 5-FU (1.5 microg/microL) with varying 10-30-50 microg/microl doses of PCNA-Rz was tested in a regimen of four sequential subretinal injections. Toxicity was monitored by biomicroscopy, indirect ophthalmoscopy, electroretinography (ERG), and histology.

RESULTS

The highest nontoxic dose for subretinal PCNA-Rz was 10 microg/microl, whereas 100 microg/microl showed disturbance of pigmentation with corresponding histological changes of retinal photoreceptor loss and retinal pigment epithelium proliferation or irregularities. Subretinal injection of all three doses of 5-FU did not show any toxicity. Serial injections of a mixture of 1.5 microg/microl 5-FU with 10 microg/microl of PCNA-Rz was found to be safe in rat eyes.

CONCLUSIONS

Subretinal injections of the combination of PCNA-Rz (10 microg/microl) and 5-FU (1.5 microg/microl) demonstrated to be safe in rat eyes during the course of this study, even with a multiple administration of four injections.

A new recombinant mosquito salivary allergen, rAed a 2: allergenicity, clinical relevance, and cross-reactivity

BACKGROUND

Mosquito salivary proteins cause allergic reactions in humans. The allergenicity, clinical relevance, and species cross-reactivity of a new 37-kDa recombinant mosquito (Aedes aegypti) salivary allergen, rAed a 2, were evaluated.

METHODS

rAed a 2 was expressed using a baculovirus/insect cell system and purified. Its allergenicity was examined using an enzyme-linked immunosorbent assay (ELISA), ELISA inhibition tests, immunoblots, and skin tests. Epicutaneous tests with the allergen, mosquito whole body extracts, and mosquito bite tests were performed on 48 volunteers. Serum rAed a 2-specific immunoglobulin E (IgE) was measured in individuals with positive mosquito saliva-specific IgE and negative controls.

RESULTS

Both immunoblots and ELISAs demonstrated that rAed a 2 bound to the IgE of mosquito-allergic individuals. The binding could be inhibited by the addition of a natural mosquito preparation. Furthermore, rAed a 2 induced immediate and delayed skin reactions. Ten per cent of 31 participants with a positive mosquito bite test had positive skin reactions to rAed a 2, compared with 32% for mosquito whole body extract. None of the participants with a negative bite test showed positive reactions to either of the two extracts. Forty-three per cent of individuals with positive saliva-IgE had positive rAed a 2-IgE. rAed a 2 was a species-shared allergen, being present in the saliva of the 11 species studied.

CONCLUSIONS

rAed a 2 has identical antigenicity and biologic activity to its native form. It can be used in the diagnosis of mosquito allergy, and is an important species-shared antigen.

Photographic estimation of the duration of high dose intravitreal triamcinolone in the vitrectomised eye

AIM

To determine the duration of residence of triamcinolone in the vitrectomised eye.

METHODS

23 eyes of 23 patients underwent intravitreal injection of high dose (20 mg) decanted triamcinolone acetonide (Kenalog) at the conclusion of vitrectomy surgery or in previously vitrectomised eyes with macular oedema from diabetes, uveitis, cataract surgery, or other surgery.

RESULTS

The median time to disappearance of triamcinolone in the vitrectomised eye was 113 days (95% confidence interval (CI) 85 to 191). In the phakic eyes the median time to disappearance was 191 days (95% CI 148 to 191). In the pseudophakic eyes the median time to disappearance was 102 days (95% CI 85 to 113). This difference was not significant (p = 0.12). There were no cases of endophthalmitis or severe inflammatory reaction. Five eyes (22%) experienced intraocular pressure rise >/=10 mm Hg.

CONCLUSIONS

High dose decanted intravitreal triamcinolone has a median residence time of 113 days in the vitrectomised eye. Although this appears to be shorter than in the non-vitrectomised eye, this study suggests that a sufficient duration of action will be present to be clinically useful.

Overexpression of Pim-1 during progression of prostatic adenocarcinoma

AIMS

Pim-1 is a serine/threonine kinase that has been shown to play an integral role in the development of a number of human cancers, such as haematolymphoid malignancies. Recently, evidence has shown Pim-1 to be important in prostatic carcinogenesis. In order to further our understanding of its role in prostate cancer, we investigated Pim-1 expression in normal, premalignant, and malignant prostate tissue.

METHODS

Using immunohistochemistry, Pim-1 expression was analysed in prostate tissue from 120 radical prostatectomy specimens. In each case, Pim-1 staining was evaluated in benign prostatic epithelium, high grade prostatic intraepithelial neoplasia (PIN), and prostatic adenocarcinoma. The number of positively staining cells was estimated, and the intensity of staining was scored on a scale of 0 to 3+.

RESULTS

Pim-1 immunoreactivity was identified in 120 cases (100%) of adenocarcinoma, 120 cases (100%) of high grade PIN, and 62 cases (52%) of benign glands. The number of cells staining in benign epithelium (mean 34%) was much lower than that in high grade PIN (mean 80%; p<0.0001) or adenocarcinoma (mean, 84%; p<0.0001). There was no significant difference between high grade PIN and adenocarcinoma in the percentage of cells staining positively for Pim-1 (p = 0.34). The staining intensity for Pim-1 was significantly lower in benign prostatic epithelium than in PIN and adenocarcinoma (p<0.001). There was no statistically significant correlation between the level of Pim-1 expression and Gleason score, patient age, tumour stage, lymph node metastasis, perineural invasion, vascular invasion, surgical margin status, extraprostatic extension, or seminal vesicle invasion.

CONCLUSIONS

Pim-1 expression is elevated in PIN and prostatic adenocarcinoma compared with benign prostatic epithelium. This finding suggests that upregulation of Pim-1 may play a role in prostatic neoplasia.

Zn2+ and Sr2+ adsorption at the TiO2 (110)–electrolyte interface: Influence of ionic strength, coverage, and anions

The X-ray standing wave technique was used to probe the sensitivity of Zn2+ and Sr2+ ion adsorption to changes in both the adsorbed ion coverage and the background electrolyte species and concentrations at the rutile (alpha-TiO2) (110)-aqueous interface. Measurements were made with various background electrolytes (NaCl, NaTr, RbCl, NaBr) at concentrations as high as 1 m. The results demonstrate that Zn2+ and Sr2+ reside primarily in the condensed layer and that the ion heights above the Ti-O surface plane are insensitive to ionic strength and the choice of background electrolyte (with <0.1 A changes over the full compositional range). The lack of any specific anion coadsorption upon probing with Br-, coupled with the insensitivity of Zn2+ and Sr2+ cation heights to changes in the background electrolyte, implies that anions do not play a significant role in the adsorption of these divalent metal ions to the rutile (110) surface. Absolute ion coverage measurements for Zn2+ and Sr2+ show a maximum Stern-layer coverage of approximately 0.5 monolayer, with no significant variation in height as a function of Stern-layer coverage. These observations are discussed in the context of Gouy-Chapman-Stern models of the electrical double layer developed from macroscopic sorption and pH-titration studies of rutile powder suspensions. Direct comparison between these experimental observations and the MUltiSIte Complexation (MUSIC) model predictions of cation surface coverage as a function of ionic strength revealed good agreement between measured and predicted surface coverages with no adjustable parameters.

Molecular evidence supporting the neoplastic nature of odontogenic keratocyst: a laser capture microdissection study of 15 cases

AIMS

The bland histology of odontogenic keratocyst (OKC) belies its capacity for aggressive behaviour. Genetic alterations of OKC have not been well studied. We examined the frequency and pattern of allelic imbalance on five different chromosome regions from 15 patients with OKC.

METHODS AND RESULTS

Laser-assisted microdissection was performed on formalin-fixed paraffin-embedded tissue. Polymerase chain reaction analysis of extracted DNA targeted five polymorphic DNA markers (D3S1285, D9S161, D11S1316, D13S290, and TP53) representing chromosome regions 3p14, 9p21, 11q23, 13q12.1 and 17p13, respectively. All 15 cases of OKC were informative at a minimum of three of five loci, with 11 informative on all five loci. Twelve of 15 cases (80%) demonstrated loss of heterozygosity (LOH). Seven cases (47%) showed LOH at more than two DNA loci. The frequency of LOH was 5/11 (45%) at D3S1285, 3/15 (20%) at D9S161, 4/14 (29%) at D11S1316, 8/14 (57%) at D13S290 and 3/15 (20%) at TP53.

CONCLUSIONS

The majority of OKCs harbour chromosomal abnormalities. This finding supports the supposition that OKCs are neoplastic. Furthermore, OKCs harbour allelic loss at some of the same loci identified in squamous cell carcinoma. This may aid in explaining the rare occurrence of squamous cell carcinoma arising in OKC.