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Biomedical subjects

T Gil

Publications and source records attributed to T Gil.

At least 19 recordsLinked to original sources

Theoretical analysis of protein organization in lipid membranes.

The fundamental physical principles of the lateral organization of trans-membrane proteins and peptides as well as peripheral membrane proteins and enzymes are considered from the point of view of the lipid-bilayer membrane, its structure, dynamics, and cooperative phenomena. Based on a variety of theoretical considerations and model calculations, the nature of lipid-protein interactions is considered both for a single protein and an assembly of proteins that can lead to aggregation and protein crystallization in the plane of the membrane. Phenomena discussed include lipid sorting and selectivity at protein surfaces, protein-lipid phase equilibria, lipid-mediated protein-protein interactions, wetting and capillary condensation as means of protein organization, mechanisms of two-dimensional protein crystallization, as well as non-equilibrium organization of active proteins in membranes. The theoretical findings are compared with a variety of experimental data.

Animals

Characteristics of calls to Israeli hotlines during the Gulf War.

The current study presents results of a survey of 3,215 calls received at seven centers of telephone emergency services (TES) in Israel during the Gulf War, when citizens of Israel experienced severe stress resulting from SCUD missile attacks. Whereas former surveys have shown that characteristics of calls to TES in Israel are generally not affected by external stressogenic events, a remarkable change was recorded in both the quantity and quality of calls received in TES centers in Israel during the Gulf War. The relative frequencies of problem categories presented by callers during the Gulf War revealed a significant increase in "environmental pressures," a category that reflected the stressful situation of the war, as opposed to intra- or interpersonal problems typical of peacetime calls. A comparison between this group of "war calls" and a control group of "nonwar calls," revealed that the two groups represented populations of callers differing in sociodemographic characteristics, expectations, and benefits from the calls. Results are discussed in reference to the unique role of TES as a source of psychological first-aid in a community crisis situation.

Demography

Increase of large granular lymphocytes in human ejaculate containing antisperm antibodies.

Using flow cytometry, we studied the expression of the CD16 antigen by lymphocytes present in human semen samples from three groups of patients: 60 fertile men attending for vasectomy, 60 sterile patients without antisperm antibodies (ASA) and 18 immunological sterile patients with ASA in their ejaculate. No significant difference was found in the concentration of leukocytes or subpopulations of these cells (monocytes, lymphocytes and granulocytes) between fertile, sterile without ASA and immunological sterile groups. However, we detected a predominance of macrophages/monocytes within the population of seminal leukocytes. No statistically significant difference was found in the absolute number of T and B lymphocytes between the three groups studied. However, a significant increase in the number of CD16+ lymphocytes was observed in the ejaculate of sterile patients with ASA as compared to the other groups. This finding might establish an important parameter in the follow-up and prognosis of patients with immunological sterility.

Adult

Oxaliplatin combined to 5-fluorouracil and folinic acid: an effective therapy in patients with advanced colorectal cancer.

Patients with colorectal carcinoma progressing after a 5-fluorouracil (5-FU)-containing regimen were eligible. One treatment cycle consisted of repeated administrations of 5-FU combined to folinic acid for six times and to oxaliplatin for three times over 50 days. 5-FU was given at the dose of 2.6 g/m2 as a continuous infusion over 24 h on days 1, 8, 22, 29 and 43 preceded by i.v. folinic acid (FA) at a dose of 500 mg/m2 over 1 h. Oxaliplatin was given 1 h after 5-FU at the dose of 130 mg/m2 over a 2 h infusion on days 1, 22 and 43. A total of 37 patients were treated according to this schedule. The rates of objective responses after the first and second treatment cycles were 28 and 17%, respectively, with rates of tumor growth control, i.e. including the stabilizations, of 55 and 28%. The median duration of response was 10 months and the median duration of stabilizations was 6 months. The median survival time from initiation of oxaliplatin-containing therapy is 10 months (2-28+). The median survival time from the diagnosis of metastatic disease is 24 months (2-40+). The main toxicities were leucopenia, diarrhea, fatigue and paresthesias. The combination of 5-FU/FA/oxaliplatin was well tolerated and appears as a meaningful therapy after failure of a previous 5-FU-containing treatment.

Adult

Improved survival in patients with locally advanced prostate cancer treated with radiotherapy and goserelin.

BACKGROUND: We conducted a randomized, prospective trial comparing external irradiation with external irradiation plus goserelin (an agonist analogue of gonadotropin-releasing hormone that reduces testosterone secretion) in patients with locally advanced prostate cancer. METHODS: From 1987 to 1995, 415 patients with locally advanced prostate cancer were randomly assigned to receive radiotherapy alone or radiotherapy plus immediate treatment with goserelin. The patients had a median age of 71 years (range, 51 to 80). Patients in both groups received 50 Gy of radiation to the pelvis over a period of five weeks and an additional 20 Gy over an additional two weeks as a prostatic boost. Patients in the combined-treatment group received 3.6 mg of goserelin (Zoladex) subcutaneously every four weeks starting on the first day of irradiation and continuing for three years; those patients also received cyproterone acetate (150 mg orally per day) during the first month of treatment to inhibit the transient rise in testosterone associated with the administration of goserelin. RESULTS: Data were available for analysis on 401 patients. The median follow-up was 45 months. Kaplan-Meier estimates of overall survival at five years were 79 percent (95 percent confidence interval, 72 to 86 percent) in the combined-treatment group and 62 percent (95 percent confidence interval, 52 to 72 percent) in the radiotherapy group (P=0.001). The proportion of surviving patients who were free of disease at five years was 85 percent (95 percent confidence interval, 78 to 92 percent) in the combined-treatment group and 48 percent (95 percent confidence interval, 38 to 58 percent) in the radiotherapy group (P<0.001). CONCLUSIONS: Adjuvant treatment with goserelin, when started simultaneously with external irradiation, improves local control and survival in patients with locally advanced prostate cancer.

Adenocarcinoma

Wetting and capillary condensation as means of protein organization in membranes.

Wetting and capillary condensation are thermodynamic phenomena in which the special affinity of interfaces to a thermodynamic phase, relative to the stable bulk phase, leads to the stabilization of a wetting phase at the interfaces. Wetting and capillary condensation are here proposed as mechanisms that in membranes may serve to induce special lipid phases in between integral membrane proteins leading to long-range lipid-mediated joining forces acting between the proteins and hence providing a means of protein organization. The consequences of wetting in terms of protein aggregation and protein clustering are derived both within a simple phenomenological theory as well as within a concrete calculation on a microscopic model of lipid-protein interactions that accounts for the lipid bilayer phase equilibria and direct lipid-protein interactions governed by hydrophobic matching between the lipid bilayer hydrophobic thickness and the length of the hydrophobic membrane domain. The theoretical results are expected to be relevant for optimizing the experimental conditions required for forming protein aggregates and regular protein arrays in membranes.

Biophysical Phenomena

Phase II study of rhizoxin in squamous cell head and neck cancer. The EORTC Early Clinical Trials Group.

To test the anti-tumour activity of rhizoxin in recurrent and/or metastatic squamous cell head and neck cancer, we performed a phase II study. Eligibility required histologically proven squamous cell head and neck cancer. Patients could only have received one prior chemotherapy. Patients were entered if WHO PS was < or = 2 and organ functions were normal. Treatment consisted of rhizoxin 1.5-2.0 mg m-2 i.v. bolus injection once every 3 weeks. Thirty-two patients entered the study. All were eligible, 31 were evaluable for toxicity and 25 for response. Toxicity mainly consisted of pain at the tumour site and leucocytopenia. Mild asthenia and stomatitis were also observed. Two objective partial responses, lasting 7.5 and 3.5 months, were seen. Rhizoxin at this dose and schedule has minor activity in recurrent and/or metastatic squamous cell head and neck cancer.

Adult

CD4+ cells in human ejaculates.

Using flow cytometry, we studied the expression of the CD4 antigen within the different cells present in human ejaculate, both in spermatozoa and round cells. In all, 20 samples of semen were obtained from fertile males; in 11 of these, we detected the presence of leukocytes, using the peroxidase test. Swim-up was performed for the analysis of the spermatozoa. From our results it may be concluded that there is no expression of the CD4 antigen on the surface of human spermatozoa or on CD45- ejaculate cells (epithelial and germinal cells). However, we did detect the presence of the CD4 antigen on the surface of the leukocyte cells (CD45+). A better characterization of these CD45+ cells made it apparent that the CD4+ cells of ejaculate are composed of T lymphocytes (helper/inducer T lymphocytes) and monocytes. Thus we may conclude that human spermatozoa do not express the CD4 antigen, the cell surface receptor for human immunodeficiency virus. However, we did detect CD4+ T lymphocytes and CD4+ monocytes in semen.

CD4 Antigens

Influence of incubation on the chromatin condensation and nuclear stability of human spermatozoa by flow cytometry.

Flow cytometry analysis was used for the accurate and objective evaluation of sperm chromatin condensation and chromatin stability of sperm nuclei. It was also possible to determine the influence of incubation on sperm chromatin. Different types of spermatozoa were studied: unprocessed spermatozoa at 1 and 45 min after ejaculation, after swim-up (migrated), spermatozoa incubated for 6 h in non-capacitating conditions (aged), or in B2 medium (capacitated) or B2 medium followed 1 h later with A23187 (reacted). All types of spermatozoa were analysed before and after treatment with various decondensation agents: sodium dodecyl sulphate (SDS), SDS plus EDTA and SDS plus disulphide-reducing agent [dithiotreitol (DTT)]. Sperm nuclei were enzymatically isolated and stained with propidium iodide. Three flow cytometric parameters were then measured: forward light scatter (cellular size), side light scatter (cellular complexity) and fluorescence (uptake of propidium iodide). Fluorescence was the most suitable parameter to study the degree of condensation and resistance to decondensation of DNA in the spermatozoa. Unprocessed spermatozoa 1 min after ejaculation underwent decondensation by all assessed treatments (anionic detergent, chelating or disulphide-reducing agents). Unprocessed spermatozoa 45 min after ejaculation and migrated spermatozoa did not undergo decondensation with SDS treatment, but decondensation occurred after treatment with SDS+EDTA or SDS+DTT. Spermatozoa incubated for 6 h under both non-capacitating (aged spermatozoa) and capacitating conditions (capacitated spermatozoa) and reacted spermatozoa were decondensed only after treatment with SDS+DTT.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcimycin

Undetectable expression of genomic progesterone receptor in human spermatozoa.

The expression of genomic progesterone receptor in human ejaculated spermatozoa was investigated. Spermatozoa from 10 fertile donors who exhibited normal semen parameters were analysed. Indirect immunofluorescence and an enzyme immunoassay using monoclonal antibodies against genomic progesterone receptor were used. Different types of spermatozoa were studied: fresh, post-swim-up (migrated), capacitated and post-artificial induction of the acrosome reaction by calcium ionophore A23187. Progestin receptor-rich T47D human breast cancer cells were used as a positive control, and progestin receptor-poor MDA-MB-231 human breast carcinoma cells were used as a negative control. Genomic progesterone receptor was not detected in fresh, migrated, capacitated and post-acrosome reaction induction human spermatozoa and MDA-MB-231 cells by either indirect immunofluorescence or enzyme immunoassay. However, in T47D cells a mean concentration of 1043.2 +/- 125.2 fmol genomic progesterone receptor/mg protein was observed by enzyme immunoassay, and indirect immunofluorescence results were positive using both flow cytometry and fluorescence microscopy. These findings suggest that the effect of progesterone on human spermatozoa is not mediated by genomic progesterone receptor.

Antibodies, Monoclonal

Thyroid hormones in fibrocystic breast disease.

This study was undertaken to evaluate the role of thyroid hormones in fibrocystic breast disease. The concentrations of thyroid-stimulating hormone (TSH), thyroxine (T4), free T4 and free triiodothyronine (T3) were determined in serum of 50 women with fibrocystic breast disease without macrocysts (cysts of over 3 mm diameter) and in the serum and breast cyst fluid (BCF) of 60 women with fibrocystic breast disease and macrocysts. Possible relationships between thyroid hormones and estradiol, dehydroepiandrosterone sulfate, testosterone, progesterone and 17-hydroxyprogesterone in the BCF also were analyzed. Serum thyroid hormone levels did not differ between the two groups. Free T3 levels were higher in BCF than in serum (p < 0.001), whereas T4, free T4 and TSH concentrations were lower in BCF as compared to serum (p < 0.001). Cysts were divided according to their K+/Na+ ratio because a ratio above 3 represents a predictor of malignant transformation. Free T3 concentrations were higher in BCF than in serum, in both low K+/Na+ cysts and in cysts with a K+/Na+ ratio above 3; those cysts with a high K+/Na+ ratio had the highest free T3 concentration. Free T3 in cysts correlated positively to the K+/Na+ ratio (r = 0.831; p < 0.001). Multiple linear regression analysis demonstrated that the concentration of free T3 in BCF was predicted statistically by the positive regression coefficient for the estradiol concentration. No candidate variable was included in the model to predict concentrations of TSH, free T4 or T4 in BCF. These data suggest an important role of free T3 in the physiology of fibrocystic breast disease.

17-alpha-Hydroxyprogesterone

[Allergic responses to date palm and pecan pollen in Israel].

Date palm (Phoenix dactylifera) and pecan (Carya illinoensis) trees are commonly planted in Israel for fruit, for shade, or as ornamental plants. Pollen grains of both species are allergenic; however, the extent of exposure to such pollen and the incidence of allergic response have not been studied here. We therefore investigated skin-test responses to pollen extracts of 12 varieties of palm and 9 of pecan in 705 allergic patients living in 3 cities and 19 rural settlements. Sensitivity to the pollen extracts of both species was much higher among residents of rural than of urban communities. Moreover, there was a definite relationship between the abundance of these trees in a region and the incidence of skin responders to their pollen. Sensitivity was frequent in settlements rich in these 2 species, such as those with nearby commercial date or pecan plantations. In general, sensitivity to date pollen extracts was lower than to pecan. However, differences in skin responses to pollen extracts of various clones were substantiated. Air sampling revealed that pollen pollution decreased considerably with distance from the trees. At approximately 100 m from a source concentrations of airborne pollen were low. Since planting of male palm and pecan trees in population centers would increase pollen pollution, it should be avoided.

Demography

Serum CA-125 in the diagnosis of acute pelvic inflammatory disease.

OBJECTIVES: To determine the efficiency of different tumor markers (CA-125, carcinoembryonic antigen, CA-15.3, CA-19.9) and insulin-like growth factor I (IGF-I) measurements as a screening procedure for acute pelvic inflammatory disease (PID). METHODS: Peripheral blood samples were obtained at the time of laparoscopy from three groups of women: (1) 50 women who underwent laparoscopic tubal ligation and had no evidence of PID (control group); (2) 20 women admitted because of suspected PID, but at laparoscopy or laparotomy had no signs of PID; (3) 20 patients who underwent acute PID diagnosed by laparoscopy. Serum levels of: CA-125, carcinoembryonic antigen, CA-15.3 and CA-19.9, and plasma IGF-I, were measured by radioimmunoassay. RESULTS: No differences were observed in the levels of CA-15.3, CA-19.9, carcinoembryonic antigen and IGF-I between the three groups studied. Serum levels of CA-125 were significantly higher in patients who had PID. Analysis of receiver operating characteristic curves showed that only CA-125 was useful in diagnosis of acute PID. The cut-off level was 43.7 U/ml for CA-125. CONCLUSIONS: Measurement of serum CA-125 concentrations is recommended as a useful test for acute PID in patients undergoing laparoscopy for pelvic pain.

Antigens, Tumor-Associated, Carbohydrate

Intracystic lipidic profile in fibrocystic breast disease.

This study was designed to investigate the lipidic profile of fibrocystic breast disease. The study entailed measuring total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein-cholesterol (VLDL-C) and triglyceride levels in the serum of 50 women with fibrocystic breast disease without macrocysts, and in the serum and breast cyst fluid of 60 women with fibrocystic breast disease and macrocysts. The relationships between the lipids analyzed in the cyst fluid and intracystic estradiol, progesterone, dehydroepiandrosterone sulfate, testosterone and 17 alpha-hydroxyprogesterone were studied. No differences were found for serum lipid levels between the two groups of patients. The levels of total cholesterol and HDL-C were found to be significantly higher, and the levels of triglycerides and VLDL-C significantly lower in breast cyst fluid compared to serum. In cysts with high potassium concentrations, we found a higher concentration of cholesterol and HDL-C and a lower concentration of LDL-C than in cysts with a potassium/sodium ratio < 3. No significant differences were found in cystic levels of triglycerides and VLDL-C. Multiple regression analysis showed that the only intracystic variable, which was, in part, positively responsible for the hormone levels measured, was HDL-C. These data suggest that local steroidogenesis in fibrocystic breast disease uses HDL-C as the substrate.

17-alpha-Hydroxyprogesterone

Follicular fluid alpha-fetoprotein, carcinoembryonic antigen, and CA-125 levels in relation to in vitro fertilization and gonadotropin and steroid hormone concentrations.

OBJECTIVE: To investigate the possible role of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and CA-125 in the ovarian follicle. DESIGN: alpha-Fetoprotein, CEA, and CA-125 were measured in human follicular fluid (FF) and correlated to IVF outcome and gonadotropin and gonadal steroid hormones. SETTING: The In Vitro Fertilization Program at Virgen de las Nieves Hospital, Granada, Spain. PATIENTS: Thirty-six FF from 12 infertile women with irreparable tubal damage who underwent treatment for ovarian stimulation with clomiphene citrate, hMG, and hCG. INTERVENTIONS: Laparoscopic follicular aspiration followed 48 hours later by ET. MAIN OUTCOME MEASURE: Serum and FF AFP, CEA, and CA-125 levels. RESULTS: alpha-Fetoprotein, CEA, and CA-125 were detected in all samples of serum and FF. There were no significant differences between the serum and FF levels. Follicular fluid AFP, CEA, and CA-125 of fertilized oocytes were similar to those in the unfertilized oocytes group. There were no significant correlations between the FF AFP, CEA, and CA 125 levels and gonadotropin and gonadal steroid hormone levels. CONCLUSIONS: alpha-Fetoprotein, CEA, and CA-125 are present in FF after ovarian stimulation, but the mean intrafollicular levels do not differ significantly regardless of the outcome of oocyte IVF.

Antigens, Tumor-Associated, Carbohydrate

Distribution of free amino acids in human preovulatory follicles.

The purpose of the present study was to investigate the possible role of intrafollicular amino acids in the human ovarian follicle. Follicular fluid (FF) and oocytes were obtained from 12 women for in vitro fertilization. Follicular development was induced with clomiphene citrate and human menopausal gonadotropin. Thirty-six FF samples, free of visible blood contamination and containing mature oocytes were used to measure free amino acids, steroids and gonadotropins. The FF were divided into three groups: (1) follicles yielding oocytes that were unfertilized (n = 12); (B) follicles containing oocytes that were fertilized and cleaved to less than four cells (n = 12); (C) follicles yielding oocytes that were fertilized and cleaved to four or more cells (n = 12). The concentrations of histidine, phenylalanine and asparagine in FF were significantly greater than those in plasma at the time of follicle aspiration. However, amino acid concentrations in FF did not differ significantly between the three groups studied. No significant relationships were found between intrafollicular levels of amino acids and those of LH, FSH, estradiol, progesterone and testosterone. These results suggest that intrafollicular amino acids are not involved in the regulation of human preovulatory follicle.

Amino Acids

Lack of expression of HLA antigens on immature germ cells from ejaculates with antisperm antibodies.

PROBLEM: The lack of expression of HLA antigen on immature germ cells from ejaculates with antisperm antibodies has been reported. METHOD: The expression of human leukocyte antigens on immature germ cells from ejaculates with antisperm antibodies (ASA) was investigated by indirect immunofluorescence using a panel of monoclonal antibodies (MAb) and automated flow cytometry. Patients were divided into two groups: fertile (prevasectomic; N = 10), and ejaculates with ASA (10 samples with IgG and IgA ASA, and five semen samples with only IgG ASA). ASA were detected on sperm using the direct immunobead test. After centrifuging semen samples on a Ficoll-Hypaque gradient, round cells obtained at the gradient interface were gated by a flow cytometer. The "immature germ cell window" was defined in terms of cellular volume and granularity. RESULTS: The percentage of gated round cells from semen samples that reacted with anti-CD45 was always less than 5%, and with anti-CD44 less than 3%. This lack of reactivity of gated round cells with MAb specific for leukocytes and epithelial cells suggests that they were immature germ cells. Immature germ cells were unreactive with W6/32 and anti-beta-2-microglobulin MAb, which suggests that these cells do not express HLA class I molecules. Similarly, no reactivity of the immature germ cells with the MAb that recognize HLA class II molecules was found. No significant differences were observed in the expression of HLA molecules on immature germ cells between the different semen samples studied: fertile, and ejaculates with ASA. CONCLUSION: The presence of ASA in ejaculate is not associated with abnormal HLA antigen expression on immature germ cells.

Animals