Biomedical subjects

G Sakellaropoulos

Publications and source records attributed to G Sakellaropoulos.

At least 19 recordsLinked to original sources

PubMed2006

Ecotoxicological properties of wastewater treated using tertiary methods.

The objective of this work was the examination of the efficiency of coagulation and ozonation processes for the production of reclaimed wastewater with low toxicity. Municipal secondary effluents were treated by FeCl3, Al2(SO4)3 (alum), and a commercial substance at metal ion concentrations of 0.5 and 1 mmol/L. Alternatively, the effluents were treated by ozonation in a semibatch ozone reactor. The feed gas was introduced at a flowrate of 3 L/min containing ozone at various concentrations, ranging between 2.5 and 8 mg/L; ozone residence times were 2, 5, 15, and 30 min. The toxic effects of the advanced treated effluents were examined by a battery of tests using the marine bacteria Vibrio fischeri, the freshwater crustaceans Daphnia magna, Daphnia pulex, and Thamnocephalus platyurus, and the rotifers Brachionus calyciflorus. The addition of alum decreased the toxic effect of reclaimed wastewater on immobilization of D. pulex, from 90 to 60%. Ozonation was also effective for toxicity removal, which decreased to 25% effect on D. pulex after treatment by 2.5 mg O3/L for 2 min. However, acute toxic effects after ozonation, were observed on V. fischeri and were related to ozone gas concentration and contact time. At the highest ozone dosage, the toxicity reached almost 100% inhibition of bioluminescence after 15 min. The toxicity of the ozonated effluents to bacteria decreased with sample storage time and was almost negligible after 48 h, indicating that the potential adverse effect of reclaimed wastewaters on receiving waters might be reduced by storage for a certain time.

Aliivibrio fischeri↗

PubMed2006

Bioavailability and toxicity of heavy metals in the presence of natural organic matter.

The effect of humic acids (HA) on the toxicity of copper, zinc and lead was investigated in this study, using the photobacterium Vibrio fischeri (Microtox test) as a test organism. The metal species and the complexation capacity of HA were predicted using model WinHumicV for speciation modeling. The toxicities of copper and lead were generally comparable, while the toxicity of zinc was lower than the ones of the other two method. The toxicity of copper decreased with the addition of HA, while the toxicity of zinc remained almost constant. The complexation of Zn with HA was low. Thus the presence of HA did not significantly influence the toxicity of Zn. For Cu and Zn, the free metal ion species showed to be basically responsible for the toxicity of these metals, while for Pb the chlorocomplexes and Pb-HA complexes contributed to the toxicity of Pb, indicating that the toxicity of heavy metals depends not only on the free metal ion species concentration but on different metal species that may be bioavailable.

Aliivibrio fischeri↗

PubMed2005

Interactive toxic effects of heavy metals and humic acids on Vibrio fischeri.

The effect of humic acids (HAs) on the toxicity of copper, zinc, and lead was investigated using the photobacterium Vibrio fischeri (Microtox test) as a test organism. The effects of HAs on metal toxicity were evaluated as functions of time and concentration in pure compound solutions. The toxicities of copper and lead were generally comparable, while the toxicity of zinc was lower than those of the other two metals. The toxicity of copper decreased with the addition of HAs, while the toxicity of zinc remained almost constant. On the other hand, the toxicity of lead increased, depending on the concentration of HAs. The interactive effects between copper and zinc and between lead and zinc were synergistic, while the interactive effect between copper and lead on the bioluminescence of V. fischeri was additive. The presence of HAs caused relatively high toxicity reduction in the binary mixtures of zinc and copper or zinc and lead, while the toxicity reduction in the case of the binary mixture of copper and lead was negligible.

Aliivibrio fischeri↗

PubMed2004

Valgus impacted proximal humeral fractures and their blood supply after transosseous suturing.

We treated 16 patients (11 women and five men, average age 45 years), all having four-part valgus impacted fractures of the proximal humerus, with transosseous suturing. All had preoperative angiography performed 6-12 h after admission. The average impaction angle was 43 degrees , and the mean lateral displacement of the humeral head was 1.4 mm. Postoperative angiography was performed 8-10 weeks after the operation followed by digital image processing using the segmentation technique. No statistically important reduction in the length and area of large (>0.5 mm) vessels was seen. Union was confirmed by the reduction in the length and area of small vessels (<0.5 mm). At a mean follow-up of 40 months, avascular necrosis was only found in one patient. The average Constant-Murley score was 87 (67-100) points, whereas the functional score in comparison with the unaffected shoulder was 94% (89-100%). Despite the small number of patients, transosseous fixation seems to preserve the remaining blood supply of the humeral head.

Adult↗

PubMed2003

Prevalence of hepatitis B and C virus infection in the general population and selected groups in South-Western Greece.

Greece is a country of intermediate endemicity for hepatitis B and low endemecity for hepatitis C with a downward trend during the last years. In the present study we investigated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in the region of South-Western Greece and tried to identify the most important risk factors of transmission. This is a unique epidemiological study, as it is the first community based study in the general population of Greece, with a methodological approach based on multi-staged random sampling. The prevalence of HBV infection seems to be decreasing with a 22.6% rate of HBV markers and a 2.1% rate of chronic HBV carriers. We found male sex, old age and intrafamiliar exposure as the major independent risk factors of HBV transmission, while sexual contact, absence of condom prophylaxis and living in rural areas seem to have also a significant impact for HBV infection. No relation was found between HBV transmission and working in health care facilities, pre-existing hospital admissions and history of transfusion. The prevalence of anti-bodies to the HCV was found 0.5%, even lower than the rate reported in the Mediterranean region. Parenteral exposure was the main risk factor for the transmission of HCV infection.

Adolescent↗

PubMed2003

Improvement of iodine deficiency after iodine supplementation in schoolchildren of Azerbaijan was accompanied by hypo and hyperthyrotropinemia and increased title of thyroid autoantibodies.

OBJECTIVE: In the mountainous areas of Azerbaijan the schoolchildren suffer from severe Iodine Deficiency (ID) with median Urinary iodine excretion (UIE) 36 mcg/l and prevalence of goiter 99% (estimated by US). In a population of 293,000 schoolchildren aged 8-14 y.o. we administered capsules containing 190 mg of iodized oil (Lipiodol-Guerbet, Cedex, France) twice yearly in 6 months apart (total 380 mg). The aim of the present study was to evaluate the efficacy, the benefits, as well as the possible side-effects in a follow-up period of 6 and 12 months after the initial administration of iodized oil. METHODS: Six and 12 months after the initial administration of iodide, two representative samples of 391 and 326 children respectively were examined. The evaluation included: estimation of goiter by US, determination of UIE and serum measurements of T3, T4, TSH, Tg, autoantibodies against thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg). RESULTS: There was an improvement in median UIE which increased from 36 mcg/l to 68 and 81 mcg/l after 6 and 12 months of treatment respectively. The prevalence of goiter decreased from 99% to 54% and 26% respectively. Tg was decreased at 6 and 12 months from the first administration, whereas TSH remained unchanged at 6 months and decreased at 12 months when compared to the latter value. Hypothyroidism was detected in 7% of children after iodide administration both at 6 and 12 months, but overt hypothyroidism was observed only in 0.5% at 12 months. Subclinical hyperthyroidism was detected in 2% and 6% after iodide administration both at 6 and 12 months. There was a significant increase in the title of thyroid auto antibodies in 6 months which was retained and increased in 12 months. There was no relation between the appearance of thyroid dysfunction and the positive thyroid auto antibodies. CONCLUSION: The dose of 190 mg iodide administered twice yearly, improved iodine deficiency and endemic goiter in schoolchildren. The increase of UIE resulted from iodide administration, was accompanied by an increased title of thyroid auto-antibodies and an increased prevalence of hyper- and hypothyrotropinemia apparently of no autoimmune etiology.

Adolescent↗

PubMed2002

Treating intraepithelial lesions of the uterine cervix by laser CO2. Evaluation of the past, appraisal for the future.

BACKGROUND AND OBJECTIVE: Carbon dioxide laser (CO2) has been widely used in the past for the treatment of squamous intraepithelial lesions (SIL) of the uterine cervix. We present our 10-year experience of using this modality while evaluating its current and future use. MATERIALS AND METHODS: From 1988 to 1998, 3,078 women were treated for an intraepithelial lesion of the uterine cervix (SIL) by laser CO2 either by vaporization or conization. The procedure was performed on an outpatient basis and was well tolerated by the great majority of patients. The mean age of the women treated by vaporization was 27.5 years whereas of those managed by conization, 34.8 years. RESULTS: From the 3,078 women, 750 (24.4%) underwent laser vaporization and the remaining 2,328 (75.6%), conization of the cervix. Complications were minimal and consisted of intraoperative and postoperative bleeding (0.56%), pelvic infections (0.04%) and cervical stenosis (1.1%). Mean follow-up time was 83 months (range 24-142). Relapsing disease (either persistent or recurrent) was detected in 5.6% of the vaporization and 3.9% of the conization group. CONCLUSIONS: The management of SIL of the uterine cervix by laser CO2 offers excellent success rates with minor complications. The preservation of the anatomical integrity of the cervical tissue offers a better follow-up of these patients and the potential for repeat treatment. Although other treatment modalities are available, we believe that laser CO2 represents an excellent surgical tool for the management of intraepithelial lesions of the uterine cervix.

Adult↗

PubMed2000

Immunohistochemical detection of retinoic acid receptor-alpha in prostate carcinoma: correlation with proliferative activity and tumor grade.

BACKGROUND: The use of retinoids as differentiation therapy is a novel approach to prostate cancer. Retinoids act via their own nuclear receptors, RARs and RXRs, modulating gene activity, cell growth and differentiation. This study provides new data on the content and cellular distribution of RARalpha protein in prostate cancer specimens, in correlation to tumor grade and proliferative activity. MATERIAL AND METHODS: A total of 84 cases of primary prostate carcinoma, divided into 3 subgroups according to tumor grade, were immunohistochemically evaluated for retinoic acid receptor-alpha (RARalpha) and Ki67 using the streptavidin/peroxidase method on formalin fixed, paraffin embedded tissues. RESULTS: RARalpha positivity was detected in all cases of prostatic carcinoma, with a more profound expression in well differentiated cancers. A statistically significant correlation between RARalpha staining and tumor grade was found (ANOVA, p < 0.031). Ki67 immunoreactivity was present in 35.7% of cases, but no correlation with tumor grade was found. When RARalpha staining was correlated with Ki67 positivity, a statistically significant correlation was present (unpaired t-test, p < 0.003). CONCLUSIONS: These findings indicate that RARalpha expression is correlated to some extent with tumor grade and its presence is more profound in highly proliferative tumors. Further studies are needed to establish the possible clinical value of the immunohistochemical evaluation of RARalpha content in tumor specimens.

Aged↗

PubMed2000

The role of antibiotics after dilatation and curettage in women with metrorrhagia in the prevention of pelvic inflammatory disease.

A follow-up study was carried out in 67 healthy women with negative vaginal-cervical cultures after an endometrial curettage for metrorrhagia. The women were separated into two treatment groups and clinically followed for one month after the operation. The first group included 33 women (aged 23-67, mean 43) who received doxycycline 200 mg daily for a period of one week after the procedure. The second group included 34 women (aged 28-70, mean 43.5) who did not receive any antibiotic regimen after the dilatation and curettage. Four and three women from the 1st and 2nd group, respectively, developed PID during follow-up; a difference not statistically significant.

Adult↗

PubMed1999

Treatment results of liquid nitrogen cryotherapy on selected pathologic changes of the uterine cervix.

One hundred and eighty-two women treated with cryotherapy were included in the study. In cases of chronic cervical inflammation full recovery was observed in 86% of subjects. In cases of Naboth cysts full recovery was observed within 6 to 8 weeks in 89% of women. In cases of cervical erosions full recovery was observed within 6 to 9 weeks in 84.9% of women. In women, with cervical epithelium dysplasia full recovery was observed within 7 to 11 weeks in treated subjects. Renewal of the pathology was observed in 15% of the women with treated cervicitis and in one of the women with cervical dysplasia within 2 to 5 years of follow-up.

Colposcopy↗

PubMed1999

Anogenital intraepithelial lesions in HIV positive patients. Report of 3 cases with 3-year follow-up.

Three cases of HIV-positive immunocompromised women, complicated by anogenital intraepithelial lesions are presented in the present paper. Two patients, aged 42 and 33, had a combination of cervical intraepithelial neoplasia grade 3 (CIN 3) and anal intraepithelial neoplasia grade 2 (AIN 2). The other one, aged 26, presented an association of CIN 2 and AIN 1. All lesions were HPV-associated and proved by colposcopically-guided biopsies.

Adult↗

PubMed1999

The management of breech presentation in the last three decades.

In order to evaluate the changes in management of breech presentation during the last three decades, a retrospective analysis of the "Alexandra" Hospital records was undertaken. The years, 1965, 1975, 1985, 1995 and finally 1997 were used as pilot years for this purpose. The cesarean section, breech presentation and breech cesarean section rates were calculated for each year. Specific breech cesarean section rates in respect to birth weight and parity as well as perinatal mortality rates were also recorded for each pilot year. The overall cesarean section rate rose from 8.0% in 1965 to 25.2% in 1995 and 25.1% in 1997 while the breech cesarean rate climbed from 16.9% in 1965 to 74.1% in 1995 and 72.3% in 1997, irrespective of birth weight. A trend towards vaginal delivery of breeches in multiparous women till 1985 became less apparent in later years. During the same period, a marked decrease of the perinatal mortality rate was observed from 70.1/1000 in 1965 to 36.6/1000 in 1997. In conclusion, a more than four-fold increase of the breech cesarean section rate was apparently rewarded by a two-fold decrease in perinatal mortality.

Breech Presentation↗

PubMed1998

Estimation of artifacts induced by the Ilizarov device in quantitative computed tomographic analysis of tibiae.

This study concerns the estimation of the artifacts introduced by the metallic frame of an Ilizarov apparatus during quantitative computed tomography for the assessment of neoosteogenesis. Ten cadaver tibiae were tomographed before and after the mounting of an Ilizarov device. The increase in mean density and in the relative number of pixels were used as indicators of the artifacts induced by the apparatus. No significant influence by the device was recorded in regions corresponding to a corticotomy site. In regions close to the metallic rings of the Ilizarov apparatus, measurements are distorted significantly, but with no influence on the assessment of neoosteogenesis.

Artifacts↗

PubMed1998

Gynecologic cancer and surgical infectious morbidity.

The purpose of this study was to evaluate retrospectively the surgical infectious morbidity in gynecologic cancer. We examined 1,180 gynecologic oncology patients: 608 women had carcinoma of the endometrium, 510 cancer of the cervix, 48 ovarian cancer and 14 vulvar cancer. Thirty-five (6%), 92 (18%), 7 (15%) and 2 (14%) were complicated by infection in carcinoma of the endometrium, cancer of the cervix, ovarian cancer and vulvar cancer, respectively. Our conclusion is that the highest surgical infectious morbidity occurs in patients with cervical cancer and the lowest in patients with carcinoma of the endometrium.

Adult↗

PubMed1997

Postmenopausal uterine bleeding.

The purpose of this study was to evaluate the incidence of the etiologic factors of postmenopausal uterine bleeding and the recurrence rate of uterine bleeding before total hysterectomy. Six hundred and twenty-eight patients (mean age 52.2) with postmenopausal uterine bleeding were studied. Atrophic endometrium was found in 522 cases (83.1%), carcinoma of the endometrium in 70 cases (11.1%), proliferative endometrium in 29 cases (4.6%) and secretory endometrium in 7 cases (1.1%). The recurrence rate of uterine bleeding was very high in carcinoma of the endometrium, moderate in proliferative endometrium and low in secretory and atrophic endometrium.

Atrophy↗

PubMed1996

Properties of K+ and Cl- channels and their involvement in proliferation of rat microglial cells.

Essentially pure (>95%) cultures of microglia were established from neopallia of newborn rats and used for whole-cell patch-clamp recording of electrophysiological properties and for proliferation studies. Two types of cultures were examined: 1) "Primary" cultures were grown in culture medium with serum and used within 3 weeks of isolation; 2) and "Colony-stimulating factor (CSF)-1-stimulated" cultures were derived from 3-week-old "primary" cultures by passaging and culturing them for several weeks longer in the presence of conditioned medium enriched in CSF-1. Microglia in the "primary" cultures expressed: 1) an inwardly rectifying K+ current (Kir) that was inhibited by Ba2+; 2) an outwardly rectifying K+ current (Kv) with many similarities to the cloned Kv1.3 channel of lymphocytes, including block by nanomolar concentrations of charybdotoxin (ChTX) and margatoxin (MgTX); and 3) an outwardly rectifying anion current with time- and voltage-independent gating. The anion current is activated reversibly under cell swelling conditions, i.e., after exposure to a hypo-osmotic bathing medium. The anion channels are highly permeable to Cl-, measurably permeable to gluconate (P(gluconate)/ PCl = 0.34), and blocked by flufenamic acid, 4-nitro-2-(3-phenylpropylamino)- benzoic acid (NPPB), and 6, 7-dichloro-2-cyclopentyl-2, 3-dihydro-2-methyl-1-oxo-1H-inden-5-yl (oxy) acetic acid (IAA-94). Microglia in the "CSF-1-stimulated" cultures expressed Kir and Cl- current, but not Kv current. Proliferation in the latter type of cultures could be slowed by omission of the CSF-1 enriched supernatant for 2 days and stimulated by adding back the conditioned medium. This "CSF-1-stimulated" proliferation was inhibited by Ba2+ (Kir blocker), and the Cl(-)-channel blockers flufenamic acid, NPPB, and IAA-94, whereas the Kv blockers ChTX and MgTX had no effect. Thus, Kir and Cl- channels appear to be necessary for "CSF-1-stimulated" proliferation of rat microglia, and there is no evidence that even a transient activation of Kv is necessary.

Animals↗

PubMed1996

Conservative management of vaginal intraepithelial neoplasia (VAIN) by laser CO2.

Carbon Dioxide Laser ablation therapy was originally offered to 25 women with Vaginal Intraepithelial Neoplasia (VAIN). The disease was primary in 12 and secondary after a previous hysterectomy in 13 cases. Treatment was accomplished under local anesthesia in 22 cases and was well-tolerated by all patients. The age of the patients ranged from 19 to 68 with a mean age of 44 years. All women were followed-up by cytology and colposcopy within a time period of 35 to 82 months (mean 49 months). Eight patients relapsed resulting in a failure rate of 32%. A second Laser CO2 treatment was offered to these patients with a final cure rate of 84% (21/25). The four cases in which the disease reappeared, after the 2nd treatment, were managed by upper colpectomy (3 cases) and follow-up (1 case). Laser CO2 ablation is an acceptable treatment modality for VAIN considering the promising cure rates and the preservation of the anatomic integrity of the vagina. Close colposcopic follow-up of these patients is necessary for early detection of disease relapses.

Adult↗

PubMed1995

Small-conductance chloride channels in human peripheral T lymphocytes.

During whole-cell patch-clamp recording from normal (nontransformed) human T lymphocytes a chloride current spontaneously activated in > 98% of cells (n > 200) in the absence of applied osmotic or pressure gradients. However, some volume sensitivity was observed, as negative pressure pulses reduced the current. With iso-osmotic bath and pipette solutions the peak amplitude built up (time constant approximately 23 sec at room temperature), a variable-duration plateau phase followed, then the current ran down spontaneously (time constant approximately 280 sec). The anion permeability sequence, calculated from reversal potentials was I-, Br- > NO3-, Cl- > CH3SO3-, HCO3- > CH3COO- > F- > aspartate, gluconate, SO4(2-) and there was no measurable monovalent cation permeability. The Cl- current was independent of time during long voltage steps and there was no evidence of voltage-dependent gating; however, the current showed intrinsic outward rectification in symmetrical Cl- solutions. The conductance of the channels underlying the whole-cell current was calculated from fluctuation analysis, using power-spectral density and variance-vs.-mean analysis. Both methods yielded a single channel conductance of about 0.6 pS at -70 mV (close to the normal resting potential of T lymphocytes). The power spectral density function was best fit by the sum of two Lorentzian functions, with corner frequencies of 30 and 295 Hz, corresponding to mean open times of 0.54 and 5.13 msec. The pharmacological profile included rapid block by external application of flufenamic acid (50 microM), 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB, 100 microM), [6,7-dichloro-2-cyclopentyl-2,3- dihydro-2-methyl-1-oxo-1H-inden-5-yl)oxy] acetic acid (IAA-94, 250 microM) or 100 microM 1,9-dideoxyforskolin. The stilbene derivatives DIDS (4,4'-diisothiocyano-2,2' disulphonic acid stilbene, 500 microM) and SITS (4-acetamido-4'-isothiocyano-2,2'-disulphonic acid stilbene, 500 microM) prevented buildup of Cl- current after a 30-min preincubation at 500 microM. When tested in a mitogenic assay, DIDS, flufenamic acid, NPPB and IAA-94 all inhibited T-cell proliferation, suggesting a physiological function in addition to the observed volume sensitivity.

Biophysical Phenomena↗