A review of odontogenic keratocysts and the behavior of recurrences.

OBJECTIVE: The purpose of this study is to report experiences of odontogenic keratocysts (OKCs) and analyze information regarding recurrences to better understand the nature of recurrences. STUDY DESIGN: Fifty-one cases of OKC treated at the Faculty of Dentistry, Chulalongkorn University, from 1988 to 2003 were studied retrospectively. Clinicoradiographic features, histologic features, and methods of treatment were reviewed. Recurrences were analyzed and compared with respect to sites of involvement, relationship to the remaining teeth, and methods of treatment. RESULTS: OKCs occurred predominantly in the 11- to 40-year-old age group. The body-angle-ramus area of mandible was the most common site of occurrence. Radiographically, the unilocular to multilocular radiolucency ratio was 2.5:1. Multilocular lesions occurred more frequently in the mandible (P < .05). Most of the lesions were diagnosed histologically as parakeratinized OKC (93.7%). The patients were followed from 1-14.6 years. However, 20 patients were lost to follow-up after a short period of time, and recurrences were found in 7 out of 31 cases (22.6%). The recurrent tumors occurred more frequently in patients who had an OKC associated with the remaining teeth and were treated by enucleation or enucleation with adjuvant therapy. CONCLUSIONS: According to a high recurrent rate of OKCs treated by enucleation, clinicians should give more attention to the dentate area if the enucleation is chosen as the treatment of choice.     

Differential modulation of proliferation, matrix metalloproteinase expression and invasion of human head and neck squamous carcinoma cells by c-erbB ligands

Evidence suggests that there is an association between the abnormal expression of members of the c-erbB receptor tyrosine kinase family and poor prognosis in head and neck squamous cell carcinomas (HNSCC). Until now, the relative contributions of different c-erbB ligands to HNSCC progression have not been clearly defined. In this paper we examined the effects of ligands with different c-erbB receptor specificities in terms of their stimulation of HNSCC proliferation, expression of matrix metalloproteinases (MMPs) and invasion. Heregulin-beta1 (HRG-β1; selective c-erbB3/B4 ligand) was found to stimulate proliferation in the majority of cell lines, whereas epidermal growth factor (EGF; EGFR ligand) and betacellulin (BTC; EGFR/B4 ligand) induced variable responses. All three ligands up-regulated multiple MMPs including collagenases, stromelysins, matrilysin and gelatinase B (MMP-9) but had minimal or no effects on gelatinase A (MMP-2), MT1-MMP and tissue inhibitors of MMPs (TIMPs). MMP-9 mRNA was induced to a higher level than other MMPs, although with slower kinetics. HRG-β1 was less active than EGF and BTC at the optimal concentration (relative potency of EGF:BTC:HRG = 3:4:1). In vitro invasion through Matrigel was also increased by all three ligands in proportion to their MMP up-regulation. A specific anti-EGFR monoclonal antibody (mAb ICR62) inhibited MMP up-regulation, migration and invasion induced by all three ligands, whereas an anti-c-erbB-2 mAb ICR12 inhibited mitogenic and motogenic responses following ligand stimulation but had no effect on MMP expression. These results suggest that c-erbB ligands may differentially potentiate the invasive phenotype of HNSCC via co-operative induction of cell proliferation, migration and proteolysis. The EGFR signalling pathway appears to be the dominant component controlling the proteolytic and invasive phenotype in HNSCC, whereas the c-erbB-2 signalling pathway is responsible, in part, for the mitogenic and motogenic effects of ligands. This revised version was published online in July 2006 with corrections to the Cover Date.     

Informal stroke rehabilitation: what are the main reasons of Thai caregivers?

The aim of this study was to identify the reasons for the provision of informal rehabilitation services at home to stroke relatives by Thai caregivers. Twenty primary informal caregivers were individually interviewed at their homes by using semistructured questions elaborated by the researchers. All interviews were recorded on audiotape. Content analysis was used to determine the reasons for performing informal rehabilitation. Four major reasons, (i) biological, (ii) psychological, (iii) social, and (iv) spiritual, emerged from our content analysis to maintain for the stroke victims the highest possible quality of life. Improvement and prevention of further deterioration were the two main concepts in the biological and psychological reasons expressed by these Thai caregivers, whereas maintaining human relations and usual social activities were the two main considerations in the social reason. The main concepts in the spiritual reason were respecting the religious beliefs, superstitions, and culture of the caregivers or patients, improving patients' empowerment, and improving caregivers' satisfaction. These four reasons encompassed the biological, psychological, social, and spiritual aspects of a holistic approach to the definition of health. The health professional in Thailand should encourage stroke caregivers to continue providing informal rehabilitation services for their stroke relatives, as it might sustain the well being of stroke survivors during their stay at home.     

A synthetic matrix metalloproteinase inhibitor prevents squamous carcinoma cell proliferation by interfering with epidermal growth factor receptor autocrine loops

Head and neck squamous cell carcinoma (HNSCC) is characterized by its capacity to invade adjacent tissues and to metastasize locoregionally. Evidence suggests that matrix metalloproteinases (MMPs) may play a causal role in HNSCC progression. While evaluating the role of MMPs in the invasion process, we made the surprising observation that a broad-spectrum MMP inhibitor, (marimastat, BB2516), inhibited the growth in vitro of some HNSCC cell lines. This inhibitory effect was only found in HNSCC cell lines overexpressing epidermal growth factor receptors. The effects of the MMP inhibitor could be reversed by adding exogenous c-erbB ligands, suggesting that the phenomenon may be related to autocrine ligand processing. This hypothesis was supported by the finding that the growth-inhibitory effect of marimastat was directly related to its ability to prevent the release of major c-erbB ligands including transforming growth factor-alpha, betacellulin and heregulin beta1 from HNSCC. Marimastat was also found to potentiate the cytotoxic effects of cisplatin both in vitro and in vivo. Our results indicate that the cleavage of several c-erbB ligands from membrane-anchored precursors requires MMP activity. We conclude that MMP inhibitors could prevent tumor progression not only by inhibiting invasion and angiogenesis, as previously shown, but also by their ability to inhibit autocrine signaling through the c-erbB receptors. Clinical trials to test this hypothesis in HNSCC should be considered.     

External validation of the SEDAN score: The real world practice of a single center

Background and Purpose:

Symptomatic intracranial hemorrhage (sICH) is the most serious adverse event in stroke patients who received i.v. rt-PA and is usually associated with poor outcomes. The SEDAN score is built up to predict sICH. We aim to externally validate the SEDAN score in Thai patients from single center in the real world practice.

Materials and Methods:

The SEDAN score of stroke patients treated with intravenous rt-PA at Thammasat University Hospital from January 2010 to June 2012 was calculated. Patients were divided into three groups including symptomatic intracranial hemorrhage (sICH), asymptomatic intracranial hemorrhage (AsICH) and no intracerebral hemorrhage (NoICH). The primary outcome of analyses was sICH. Each parameter of the SEDAN score and correlation between score and sICH were analyzed with univariate and multivariate model.

Results:

295 patients (18.6% of stroke admission) were treated with i.v. rt-PA. 13 patients (4.4%) had sICH and 31 patients (10.4%) had AsICH. Baseline blood sugar >12 mmol/l, early infarction, hyperdense cerebral artery, age >75 years-old and NIHSS ≥10(SEDAN) were associated with sICH by univariate analysis (P value = 0.018, <0.001, <0.001, 0.002 and 0.027 respectively). The rate of sICH occurrence was increased in accordance with the increasing of the SEDAN score. By multivariate analysis, odds ratio of baseline blood sugar >12 mmol/l, early infarction, hyperdense cerebral artery, age >75 years-old and NIHSS ≥10 were 1.248, 2.503, 1.107, 1.532 and 1.263 respectively.

Conclusions:

The SEDAN score was practical to use and predictive in Thai population. Each parameter of the SEDAN score was an independent risk factor for sICH after treatment with i.v. rt-PA.     

Assessment of basic seminal characteristics, sperm cryopreservation and heterologous in vitro fertilisation in the fishing cat (Prionailurus viverrinus)

Conservation of the fishing cat, a threatened south-east Asian felid, could benefit from effective ex situ genetic management and breeding programmes, including the use of assisted reproduction. The aims of the present study were to: (1) characterise basal seminal traits of fishing cats in Thailand zoos; and (2) investigate the effect of cryopreservation on sperm motility, acrosomal integrity and in vitro function. Seminal traits were evaluated in electroejaculates collected from eight males. Spermatozoa were diluted in n-tris(hydroxymethyl)-methyl-2-aminoethanesulfonic acid Tris (TEST)-yolk buffer (TYB) without glycerol, then diluted further with TYB with glycerol (4% final concentration) at either 25 degrees C or after slow cooling to 5 degrees C and frozen in straws over liquid nitrogen vapour. After thawing, sperm function was assessed by insemination of viable domestic cat oocytes. Fishing cat ejaculates averaged (+/- s.e.m.) 43.6 +/- 14.2 x 10(6) motile spermatozoa with 33.5 +/- 6.8% normal sperm morphology. Semen processing had a negligible effect (P > 0.05) on sperm motility and acrosomal integrity, but values were reduced (P < 0.05) after thawing. All thawed samples fertilised domestic cat oocytes, with 62.1% (36/58) of mature oocytes cleaving. Glycerol addition at 5 degrees C resulted in higher (P < 0.05) post-thaw motility and intact acrosomes than glycerol addition at 25 degrees C. In conclusion, good-quality ejaculates can be obtained from Thai fishing cats and their spermatozoa exhibit adequate function after cryopreservation for in vitro fertilisation procedures.     

Behavioral and social issues among volunteers in a preventive HIV vaccine trial in Thailand

Behavioral and social issues were investigated in 363 phase I/II preventive HIV-1 vaccine trial volunteers in Thailand. These issues included risk behavior, HIV knowledge, distress, and social consequences of vaccine trial participation. Data were collected at baseline and at 4-, 8-, and 12-month follow-up visits. Volunteers reported relatively low levels of risk behaviors at baseline and at follow-up. Overtly negative reactions from family or friends were reported by 5.9%. No experiences of discrimination in employment, health care, or insurance were reported. Mean levels of distress were low throughout the trial, and HIV-related knowledge was high, although it was common to consider the possibility of HIV transmission through casual contact. Findings add to the evidence that preventive HIV vaccine trials are feasible in Thailand.     

Gene expression profiling allows distinction between primary and metastatic squamous cell carcinomas in the lung

Lung neoplasms commonly develop in patients previously treated for head and neck carcinomas. The derivation of these tumors, either as new primary lung cancers or as metastatic head and neck cancers, is difficult to establish based on clinical or histopathologic criteria since both are squamous cell carcinomas and have identical features under light microscopy. However, this distinction has significant treatment and prognostic implications. Gene expression profiling was performed on a panel of 52 sequentially collected patients with either primary lung (n = 21) or primary head and neck (n = 31) carcinomas using the Affymetrix HG_U95Av2 high-density oligonucleotide microarray. Unsupervised hierarchical clustering with Ward linkage and the Pearson correlation metric was performed. To assess robustness, bootstrap resampling was performed with 1,000 iterations. A t test of the normalized values for each gene was used to determine the genes responsible for segregating head and neck from lung primary carcinomas, and those with the most differential expression were used for later analyses. In the absence of a large "test" set of tumors, we used a supervised leave-one-out cross-validation to test how well we could predict the tumor origin. Once a gene expression profile was established, 12 lung lesions taken from patients with previously treated head and neck cancers were similarly analyzed by gene expression profiling to determine their sites of origin. Unsupervised clustering analysis separated the study cohort into two distinct groups which reliably remained segregated with bootstrap resampling. Group 1 consisted of 30 tongue carcinomas. Group 2 consisted of 21 lung cancers and 1 tongue carcinoma. The clustering was not changed even when normal lung or tongue profiles were subtracted from the corresponding carcinomatous lesions, and a leave-one-out cross-validation showed a 98% correct prediction (see Supplementary Data 1). A minimum set of 500 genes required to distinguish these groups was established. Given the ability to segregate these lesions using molecular profiling, we analyzed the lung tumors of undetermined origin. All cases clearly clustered with either lung or tongue tumor subsets, strongly supporting our hypothesis that this technique could elucidate the tissue of origin of metastatic lesions. Although histologically similar, squamous cell carcinomas have distinct gene expression profiles based on their anatomic sites of origin. Accordingly, the application of gene expression profiling may be useful in identifying the derivation of lung nodules and consequently enhances treatment planning.