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Biomedical subjects

G Nicolis

Publications and source records attributed to G Nicolis.

At least 55 records · Page 3Linked to original sources
PubMed1985

Some further features for differential diagnosis between squamous cell carcinomas and basal cell epitheliomas.

Two further methods for the characterization of epidermal skin tumors are described: the antinuclear antibody (ANA) immunofluorescent test, which consists of indirect immunofluorescence with known high titer sera containing homogenous ANAs on epidermal skin tumors, and the ammoniacal-silver cytochemical method, which specifically stains nuclear histones. Squamous cell carcinomas (SCCs), basal cell epitheliomas (BCEs) as well as control specimens from normal skin and benign epidermal hyperplasias were studied. The ANA immunofluorescent test was positive for most SCCs, mixed SCC and basal cell carcinomas and metatypical BCEs. The ammoniacal-silver method gave a characteristic staining pattern shared among SCCs, mixed carcinomas and metatypical BCEs. BCEs, besides metatypical ones, were always negative by the ANA immunofluorescent test and the same applied for the control specimens. The ammoniacal-silver method gave a characteristic staining pattern for BCEs and control sections quite different from the staining pattern of the more aggressive forms of epidermal tumors. The two methods usually yielded parallel results.

Antibodies, Antinuclear↗
PubMed1985

The dermal cellular infiltrate and cell-mediated immunity in skin carcinomas.

The cell-mediated immunity in nonmelanotic skin cancer was studied in 115 patients. The diagnosis and type of skin cancer was histologically evaluated. The T cell levels and leukocyte migration test in preoperative patients with squamous cell skin carcinoma (SCSC) and metatypical basal cell epithelioma were significantly lower than in the noncancer control population. The immunocompetence was not impaired in patients with basal cell epithelioma (BCE) and even in those with BCE that showed deep invasiveness and paucity of lymphocytic infiltration. There was a direct correlation between cell-mediated immunity and the lymphocytic infiltration and differentiation of the cells in SCSC.

Adult↗
PubMed1984

Hypoglycemia associated with carcinoid tumors. A case report and review of the literature.

The authors report a 73-year-old man with a jejunal carcinoid tumor and spontaneous hypoglycemia. Plasma insulin was suppressed (insulin/glucose ratio, 0.2), and nonsuppressible insulin-like proteins (NSILP) were elevated. Seven other patients with carcinoid or related tumors associated with hypoglycemia were found in the literature. Nonsuppressible insulin-like proteins were not measured in these patients.

Aged↗
PubMed1984

Histocompatibility antigens HLA-A, -B, -DR in Greek patients with Kaposi's sarcoma.

Thirty-two Greek patients with histologically documented Kaposi's sarcoma, aged 46 to 82 years, were typed for HLA-A, B and DR antigens. None of them was homosexual and they had not been subjected to any immunosuppressive therapy. The study revealed a significant increase of HLA-DR5 (53.1% vs. 21.4%, R.R. 4.1) and a decreased frequency of HLA-DR1 (3.3% vs. 16.6%, R.R. 0.16). An increased frequency of HLA-B18 was also noted (43.7% vs. 20.7% R.R. 2.96). These results indicate that the same positive association with HLA-DR5 antigen is observed in Greek patients as in other patients of Mediterranean origin and support the view that HLA linked factor(s) may have a role in the development of the disease.

Aged↗
PubMed1981

Oral submucous fibrosis in a Greek female.

Submucous fibrosis of the oral cavity is a disease affecting almost exclusively the Indian race, although sporadic cases have been described in non-Indians. Its aetiology is unknown and dietary factors have been incriminated in its pathogenesis, such as chilli ingestion. In this paper we present a case of oral submucous fibrosis in a 67-year-old Greek female, who two years after initial diagnosis developed squamous cell carcinoma of the tongue. The clinical course and histological findings are described and the potential of this disease as a predisposing factor for the development of malignancies of the oral mucosa is discussed.

Aged↗
PubMed1981

Symmetry breaking and pattern selection in far-from-equilibrium systems.

A mechanism enabling nonequilibrium systems to select spatially asymmetric solutions is outlined. It operates when a macroscopic mode undergoing a symmetry-breaking bifurcation can interact with a polar or a chiral field not explicitly involved in the bifurcation. The perturbation of the bifurcation induced by the field allows the system to capture the external asymmetry and build patterns of preferred polarity or preferred chirality. The chemical and biological implications of forming such an asymmetric medium are discussed.

Journal Article↗
PubMed1980

Antigenic alterations in tumors of epidermal origin.

One hundred tumors of epidermal origin were studied by means of indirect immunofluorescence technique with sera from patients with proven pemphigus and bullous pemphigoid. We found that in tumors of epidermal origin, there was a loss of antigenicity of the intercellular substance and basement membrane; this was minimal for benign tumors, greater for premalignant tumors, and very clear for malignant tumors. We also found a gross correlation between the histologically proven malignancy of squamous cell carcinoma and the grade of antigenic loss; both for the intercellular substances and for the basement membrane antigens. However, this did not yeild definite results in the group with basal cell carcinoma. With regard, especially, to the intercellular substance antigen, it seemed to be completely independent of histologic type of basal cell carcinoma. We found that the duration of the epidermal tumor did not correlate with the percentage of intercellular substance and basement membrane antigenic loss. This suggested that the antigenic loss was an early feature of neoplastic behavior. The deeper parts of the malignant tumors in the dermis showed a lower percentage of antigenicity for both antigens.

Antigens, Neoplasm↗
PubMed1980

Immunological study of keratoacanthomas.

Twelve patients with keratoacanthoma were studied to assess the role and importance of immunological factors in tumor regression. Direct immunofluorescence was determined with immunoglobulins, complement (C3), and fibrin to estimate the deposition of these factors in the lesion area. Indirect immunofluorescence was also undertaken using pemphigus and bullous pemphigoid sera against the keratoacanthoma lesion to study the presence or absence of tissue-specific antigens (T.S.A.) in intercellular substance and basement membrane. Finally, the cell-mediated immunity was studied using two in vitro parameters: (a) The estimation of T-lymphocytes through the formation of E-rosettes and (b) the estimation of the leukocyte migration inhibition factor (LIF). Our findings show that specific humoral immune mechanisms are apparently not involved in the spontaneous regression of keratoacanthoma. Cell-mediated immune mechanisms are evidently not responsible for the resolution of the tumor.

Adult↗
PubMed1980

Immunopathology of oral mucosa in bullous pemphigoid.

The immunopathology of the oral mucosa was studied in twenty-nine patients with bullous pemphigoid. The 14 patients with simultaneous involvement of the skin and oral mucosa had positive oral mucosa biopsies by direct immunofluorescence, whereas 85.7 percent had positive skin biopsies. Of the fifteen patients with only skin lesions, 80 percent had positive oral mucosa biopsies by direct immunofluorescence, although the oral cavity was clinically free of disease. A total of 89.6 percent of the patients had positive oral mucosa biopsies, and an equal percentage had positive skin biopsies. IgG was present in the immune deposits in all positive biopsies, and in eight cases C'3 was detected as well. Circulating antibasement membrane zone antibodies were detected in 79.3 percent of the cases when a compound animal substrate was used and in 82.7 percent of the cases when healthy human oral mucosa was used as substrate.

Adult↗
PubMed1980

Epidemiology of cutaneous leishmaniasis in Greece.

Cutaneous leishmaniasis is a disease endemic in Greece. Cases collected between the years 1975 and 1979 are analyzed from a clinico-epidemiologic point of view. Prevalence is highest in the Ionian islands and Crete. The disease most commonly affects individuals 10 to 20 years of age. The exposed parts of the body are most commonly involved, particularly the face. The period of highest incidence is mid-winter.

Adolescent↗
PubMed1980

Immunohistochemical study on 70 human embryos concerning the epidermal binding of pemphigus and pemphigoid antibodies.

In the present study, the development of pemphigus and bullous pemphigoid antigens was investigated by means of the indirect immunofluorescence technique using sera of pemphigus and bullous pemphigoid patients, respectively, on human foetus skin antigenic substrate. Seventy skin specimens from embryos of 9-38 weeks of gestation were studied. Both pemphigus and bullous pemphigoid antigens were observed for the first time at about 16 weeks of gestation. Pemphigus antigen has a slower rate of evolution. Between 30 and 38 weeks both antigens were detected as strongly positive.

Antigens, Surface↗
PubMed1976

Sustained oscillations and threshold phenomena in an operon control circuit.

A genetic regulatory model involving a positive feedback (via induction) and a negative feedback (via catabolite repression) is analyzed and applied to the problem of the lac operon regulation in E. coli. Damped and sustained oscillations of the limit cycle type are found along with threshold phenomena corresponding to multiple limit cycles or to multiple steady states, for values of the parameters compatible with experimental data. A comparison with the observations of Knorre and Goodwin is outlined.

Escherichia coli↗