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Biomedical subjects

G Laskaris

Publications and source records attributed to G Laskaris.

At least 19 recordsLinked to original sources

Leukoplakia and intraoral malignancies: female cases increase in Greece.

UNLABELLED: In the developed world, intraoral malignancies are more frequent in males than females. Recent observations from Greece suggest that the number of females is increasing. AIM: The present study investigates gender and age statistics among subjects with cancers of the mouth or leukoplakia. METHODS: Five hundred and twelve subjects of Greek origin participated in this analysis. Chi-square and logistic regression statistics were used to compare if there are differences in participants' gender and age, stratified by histological type. RESULTS: Epithelial cancers and leukoplakia exhibited equal distributions among men and women. Men were diagnosed at a much younger age than women. Our data also indicates a progression in the process of epithelial cancer development, as benign leukoplakia was diagnosed 2-4 years earlier than epithelial dysplasia and 8 years earlier than squamous cell carcinoma (SSC). The same age difference was observed in non-Hodgkin's lymphoma, although the male to female ratio was 3:1. In regards to anatomy, 47% of SSC appeared in the tongue. The most prevalent site for the development of non-Hodgkin's lymphoma was the gingival (50%), followed by the palate (40%). CONCLUSION: Although oral cancer occurs earlier in men than women, the risk of females tends to be similar to that of males.

Age Factors↗

Factors associated with delay in the diagnosis of oral cancer.

Early detection and treatment improve the prognosis for oral cancer. Delays from the onset of symptoms to clinical diagnosis are common. Our aim is to identify factors associated with this delay. Between 1995 and 1998, we interviewed 105 consecutive patients with histologically confirmed oral cancer in Greece. If 21 or more days elapsed from the time the patient noticed major symptoms to a definitive diagnosis, we called it a delay (52% of cases). We used logistic and linear regression to estimate odds ratios of delayed diagnosis and to identify correlates of length of delay, respectively. Former smokers had a 4.3 times greater risk of delayed diagnosis compared with current smokers (95% confidence interval: 1.1-17.1). The length of delay was greater among single patients, non-smokers, or those with stage IV tumors. Clinicians should be advised that delay in the diagnosis of oral cancer occurs frequently, even in individuals who do not smoke heavily.

Adult↗

Smoking and alcohol in the etiology of oral cancer: gender-specific risk profiles in the south of Greece.

Oral and pharyngeal cancer (OC) mortality is very low in Greece, especially among men, compared to other European countries. We conducted a case-control study of OC in Athens, and obtained information on tobacco, alcohol use and other potential risk factors and confounding variables for 110 incident cases and 115 hospital-based controls. We used multivariate logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Tobacco smoking (pack years, P(trend)=0.01) and alcohol use (drinks/week, P(trend)=0.07) were independent risk factors, with a multiplicative effect for combined exposures (OR, 8.3; 95% CI, 2.4-29.1, for >28 alcohol drinks/week and >50 pack years of cigarette smoking). The type of alcoholic beverage also seemed important: drinking ouzo and tsipouro (liquors of high ethanol concentration) was associated with greater increased OC risk than drinking comparable amounts of wine, beer or dark spirits. While alcohol drinking is more common for male cases versus controls, few men reported regularly consuming large quantities of ethanol associated with highest risk of OC in other studies. This may partially explain the low rates of male OC mortality in Greece. Among the 38% of our cases who were women, however, neither smoking nor alcohol drinking frequencies were significantly elevated compared to controls, and so the etiology of OC risk in females requires further investigation.

Adult↗

Purification and partial characterisation of geranylgeranyl diphosphate synthase, from Taxus baccata cell cultures. An enzyme that regulates taxane biosynthesis.

Geranylgeranyl diphosphate (GGPP) synthase, an enzyme that regulates taxane biosynthesis, was purified to homogeneity from cell cultures of Taxus baccata. The molecular weight of the native protein was estimated to be 76+/-2 kDa, resulting from the association of two apparently identical subunits having a molecular weight of 38 kDa. Farnesyl diphosphate (K(m) 2.46 µM) in combination with isopentenyl diphosphate (K(m) 1.5 µM) was the most effective substrate. Dimethyl allyl diphosphate was a poorer substrate (K(m) 12.7 µM). Mn(2+) ion at 4 mM in combination with Mg(2+) of 2 mM gave the greatest stimulation of activity. The pI of the enzyme was lower than 4 and the pH optimum was between 6.9 and 7.2. The enzyme activity was found in the 20000xg (centrifugal force) pellet and a non-ionic detergent was used for its extraction. The inclusion of detergent was not necessary during subsequent chromatographic steps.

Journal Article↗

"High risk" HPV types are frequently detected in potentially malignant and malignant oral lesions, but not in normal oral mucosa.

Studies on the involvement of the human papillomavirus (HPV) in initiation and progression of oral neoplasia have generated conflicting results. The observed discrepancy is attributable mainly to the varying sensitivity of the applied methodologies and to epidemiologic factors of the examined patient groups. To evaluate the role of HPV in oral carcinogenesis, we analyzed 53 potentially neoplastic and neoplastic oral lesions consisting of 29 cases of hyperplasia, 5 cases of dysplasia, and 19 cases of squamous cell carcinomas, as well as 16 oral specimens derived from healthy individuals. A highly sensitive nested polymerase chain reaction (PCR) assay was used, along with type-specific PCR, restriction fragment length polymorphism analysis, dot blotting, and nonisotopic in situ hybridization. Nested PCR revealed the presence of HPV DNA in 48 of the 53 (91%) pathologic samples analyzed, whereas none (0%) of the normal specimens was found to be infected. Positivity for HPV was independent of histology and the smoking habits of the analyzed group of patients. At least one "high risk" type, such as HPV 16, 18, and 33, was detected by type-specific PCR in 47 (98%) infected specimens, whereas only 1 (2%) squamous cell carcinoma was solely infected by a "low risk" type (HPV 6). HPV 16 was the prevailing viral type, being present in 71% of infected cases. Single HPV 16 and HPV 18 infections were confirmed by restriction fragment length polymorphism. HPV 58 was detected by dot blotting in three hyperplastic lesions. HPV positivity and genotyping were further confirmed, and the physical status of this virus was evaluated by nonisotopic in situ hybridization. Diffuse and punctate signals, indicative of the episomal and integrative pattern of HPV infection, were observed for low- and high-risk types, respectively. Our findings are suggestive of an early involvement of high-risk HPV types in oral carcinogenesis.

Adult↗

Epithelioid hemangioma (angiolymphoid hyperplasia with eosinophilia) in the oral mucosa. A case report and review of the literature.

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a benign uncommon entity whose aetiology and pathogenesis is under debate. Clinically, it is characterised by cutaneous papules or nodules. Cases of this entity reported in the oral mucosa are very rare. We describe such a case, discuss the problems of histological differential diagnosis between ALHE and other diseases of the region and review the literature.

Adult↗

Oral histoplasmosis as an indicator of HIV infection.

Histoplasmosis as a serious opportunistic infection in association with AIDS has assumed considerable importance. We have gathered 20 case reports from the literature of oral histoplasmosis in HIV-infected patients. In some cases, oral lesions appear to be the primary or only manifestation of disease. We report one such case of oral histoplasmosis in a bisexual man who was seen with ulcerations on the palate and proved to be infected by HIV.

AIDS-Related Opportunistic Infections↗

Paraneoplastic pemphigus: a review.

Paraneoplastic pemphigus (PNP) is a relatively recently described autoimmune disorder, distinguished from pemphigus vulgaris or foliaceus by specific clinical, histologic and immunologic criteria. In the present review, 18 cases of paraneoplastic pemphigus reported so far are discussed. The polymorphism, extent and persistence of skin and mucosal lesions are discussed while the problems of differential diagnosis and the significance of the associated neoplasms are also stressed. The underlying malignancy in the majority of the cases has been of lymphoid origin and has preceded the clinical presentation of pemphigus. All patients have had oral and cutaneous lesions. In 66.6% of the patients there was a poor response to therapy.

Aged↗

Oral manifestations of infectious diseases.

The oral manifestations of infectious diseases is a major topic since the prevalence rate has increased, and usually poses diagnostic and therapeutic dilemmas to the oral clinician. The clinical features of the most common and important oral infectious diseases are discussed.

Actinomycosis, Cervicofacial↗

Oral hairy leukoplakia in a child with AIDS.

A case of a 9-year-old boy with AIDS and severe hairy leukoplakia on the tongue is reported. Clinically it appears as a bilateral whitish-grey, nonremovable lesion on the lateral margins of the tongue with characteristic vertical corrugations. The lesion failed to respond to topical and systemic antifungal treatment. In contrast, it completely disappeared after treatment with 600 mg acyclovir per day for 1 month. During the hairy leukoplakia development the CD4-lymphocytes count was 95/microL.

AIDS-Related Opportunistic Infections↗

Oral manifestations in glycogen storage disease type 1b.

Glycogen storage disease type 1b is a rare metabolic disorder which affects the transport system of glucose-6-phosphatase metabolism. As a result, hepatomegaly, failure to thrive, renal dysfunction and recurrent infections occur in affected patients. In this paper, the oral complications in three children with glycogen storage disease type 1b are discussed. Oral ulcers were a common finding, probably due to severe neutropenia and impaired neutrophil migration which characterises the onset of this rare disorder.

Child, Preschool↗

Unpigmented intramucosal nevus of palate. An unusual clinical presentation.

A case of unpigmented intramucosal nevus occurring in the palatal mucosa is described. It presented as a nodule and was diagnosed clinically as fibroma. The correct diagnosis was established histologically and immunohistochemically; the importance of this lesion is that it should be considered in the differential diagnosis of oral soft-tissue tumors.

Diagnosis, Differential↗

Histocompatibility antigens and geographic tongue.

The HLA-A, B and HLA-DR antigens were investigated in 50 unrelated Greek persons with geographic tongue and in 380 healthy control persons. An increased incidence of DR5 and DRW6 antigens was observed in the blood of persons with geographic tongue. Ten (20%) of them had the DRW6 antigen, and it was significantly increased compared with 29 (7.6%) of the controls (p < 0.01, RR = 3.32). Twenty-seven (54%) of the experimental group showed DR5 antigen compared with 136 (35.7%) of the controls (p < 0.025, RR = 2.18). On the contrary, only 12% (5) of the experimental group had the B51 antigen in comparison with the controls (26.3%) (p < 0.05, RR = 0.37). A decrease of the DR2 antigen was also found in the persons with geographic tongue (24%) in comparison with the controls (39.2%) (p < 0.05, RR = 0.58).

Adolescent↗

Benign cartilaginous tumor of the gingiva. A case report.

Benign cartilaginous tumors of the intraoral soft tissues are rare and are typically seen in the tongue, buccal mucosa, or soft palate. They comprise a diverse group of lesions that are usually defined as cartilaginous choristomas or chondromas. The case reported was located on the palatal maxillary gingiva of the first premolar of a 56-year-old white woman. It appeared as a small firm tumor covered by normal mucosa, with the underlying bone intact on radiographic examination. Histologic examination of the excised lesion revealed a circumscribed mass of cartilaginous tissue with occasional cells presenting atypical nuclear features. Two years after initial presentation, the patient is free of recurrence.

Chondroma↗