I G Ron

Tel Aviv University, Tel Aviv, Tel Aviv, Israel

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Publications (47)110.61 Total impact

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    ABSTRACT: Carboplatinum was injected into four groups of mice for 5 successive days at one out of four daily equidistant hours. Upon the cessation of these injections, granulocyte colony stimulating factor was injected into half of these mice for 2 days at the same times. The stimulating factor was also injected into groups of untreated mice for 2 days at the same times. In each experiment the rhythms of four variables were monitored after the cessation of all injections: peripheral WBC count, bone marrow and sperm stem cells DNA synthesis, and sperm ribosomal RNA content. The results indicated that in the course of repeated drug administrations, variables' rhythm parameters (phases and periods) were altered. These changes have to be considered in chronotherapeutic schedules when variables which serve for toxicity diagnosis or as drug target are rhythmic in nature.
    Biological Rhythm Research 08/2010; February 1998(1-Vol. 29):98-104. DOI:10.1076/brhm.29.1.98.3039 · 1.22 Impact Factor
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    ABSTRACT: Spontaneous regression of pure seminoma metastases is a rare phenomenon, with only a few cases reported to date. To the best of our knowledge, this is the first report of regression of anaplastic pure seminoma metastases located in the retroperitoneum. We present a 27-year-old man, a marihuana smoker, with metastatic pure anaplastic seminoma in the high retroperitoneal lymph nodes. After orchiectomy, his metastases regressed with no medication. Several mechanisms are suggested to explain this phenomenon, which still remains elusive.
    American Journal of Clinical Oncology 09/2002; 25(4):380-2. DOI:10.1097/00000421-200208000-00012 · 2.61 Impact Factor
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    ABSTRACT: Megestrol acetate (MA) has glucocorticoid activity and can induce significant secondary adrenal suppression. We designed this study to determine the extent of adrenal insufficiency in cancer patients receiving MA by utilising a sensitive low-dose adrenocorticotropin (ACTH) stimulation test. Adrenal function was assessed by a low-dose (0.625 microg) ACTH (1-24) stimulation test in 30 patients receiving MA for metastatic cancer. 10 of the patients who failed this test underwent a standard (250 microg) test on another day. Adrenal function was also evaluated in 15 of the patients by measuring the excretion of free cortisol in 24-h urine samples. Peak serum cortisol levels following stimulation with low-dose (0.625 microg) ACTH (1-24) were <18 microg/dl in 16 of 30 (53%) patients, of whom 9 had a basal serum cortisol level of <5 microg/dl. Five of 16 poor responders to the low-dose test showed normal stimulation with the standard (250 microg) ACTH (1-24) test. Thus, adrenal insufficiency would fail to be detected by the standard high dose test in these patients. Patients who failed the low-dose ACTH (1-24) test had lower 24-h urinary free cortisol excretion (8.7+/-10.3 microg/24 h) than normal responders (35+/-12.7 microg/24 h). Impaired adrenal function is common in cancer patients receiving MA. The low-dose ACTH (1-24) test is apparently capable of revealing adrenal insufficiency undetected by the standard high-dose ACTH test. Patients receiving MA might have inadequate adrenal function during episodes of infection or after withdrawal of MA therapy and this may require prompt corticosteroid treatment.
    European Journal of Cancer 07/2002; 38(11):1490-4. DOI:10.1016/S0959-8049(02)00077-1 · 4.82 Impact Factor
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    ABSTRACT: Various bacterial strains exhibit colonial branching patterns during growth on thin poor substrates. The growth can be either diffusion-limited or kinetic-limited, according to the imposed growth conditions. We present experimental observations of patterns exhibited by the bacterial strains Paenibacillus dendritiformis and Paenibacillus vortex. All manners of branching patterns are observed, the three main being: (1) basic branching; (2) chiral branching; (3) vortex branching. We show that the following biological features can explain the spectrum of observed patterns: (1) Formation of a lubricating fluid. (2) Food chemotactic. (3) Attractive and repulsive chemotactic signaling. (4) Flagella handedness. (5) Transition into pre-spore state. In the theoretical studies we employ knowledge drawn from branching patterning in non-living systems and the mathematical properties of reaction–diffusion models and atomistic models. The above can be used not just to describe existing biological understanding, but also to derive new understanding. For example, reaction–diffusion models that include bacterial density and nutrient concentration, can exhibit branching dynamics if the growth term is a meta-stable fixed point or if the diffusion is state dependent. We show that biologically the growth term has to be an unstable fixed point, but that state-dependent diffusion can represent the lubrication fluid excreted by the bacteria. Copyright © 2001 John Wiley & Sons, Ltd.
    Mathematical Methods in the Applied Sciences 11/2001; 24(17‐18):1429 - 1468. DOI:10.1002/mma.190 · 0.88 Impact Factor
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    ABSTRACT: A multicenter phase III randomized study compared the efficacies of two adjuvant polychemotherapeutic regimens in 145 patients with stage II node-positive breast cancer. The standard chemotherapy combination, CMF (cyclophosphamide, methotrexate, 5-fluorouracil), was administered to 77 women. The experimental protocol, CNF (cyclophosphamide, mitoxantrone, 5-FU), in which mitoxantrone (Novantrone) replaced methotrexate, was given to 68 patients. Follow-up of the 145 patients by six participating hospitals showed no statistically significant difference (p = 0.6) between the two treatment regimens during a median follow-up of 4.5 years in terms of overall survival. There was, however, a significant advantage (p = 0.04) in the disease-free survival for those receiving mitoxantrone (mean survival 4.4 years for CNF versus 2.7 years for CMF). Toxic side effects associated with CNF (particularly alopecia and myelotoxicity) were relatively more frequent but acceptable and did not lead to dose reduction. In light of its association with improved disease-free survival in this study, larger studies should be undertaken on the role of mitoxantrone as adjuvant treatment in stage II breast cancer.
    American Journal of Clinical Oncology 09/2001; 24(4):323-7. DOI:10.1097/00000421-200210000-00020 · 2.61 Impact Factor
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    ABSTRACT: Disagreement persists on the necessity of axillary lymph node dissection for small T1 stage unilateral breast cancers. In this study of 120 women with T1 primary tumors who underwent extensive dissection, better definition of pathological factors that can predict axillary node metastases might have spared 88 (73.3%) who were node negative. We assessed age, tumor size, histology, grade and hormone receptor status as possible indicators of lymph node involvement. As expected, tumor size was a strong predictor of the likelihood of node involvement (p = 0.026 in univariate and p = 0.0024 in multivariate analyses). Progesterone receptor status also correlated significantly (p = 0.0008 in univariate and p = 0.017 in multivariate analyses) with axillary positivity. Tumor grade was found to be significant (p 0.018) only in univariate analysis. These findings contribute to the ongoing search for confident selection of subgroups of patients who will undergo lumpectomy but can safely be spared axillary node dissection.
    Acta Oncologica 02/2001; 40(5):629-32. · 3.71 Impact Factor
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    ABSTRACT: The purpose of this work was to evaluate the ability of testing for high-risk human papillomavirus (HPV) types using the hybrid capture technique to predict the presence of cervical intraepithelial neoplasia (CIN) II,III in patients with repeated atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LGSIL) on Pap smears. Hybrid capture testing and tissue biopsy were performed on 503 consecutive women with ASCUS or LGSIL on repeated Pap smears who were referred for colposcopy. A highly significant association (P < 0.0001) was found between a positive test for high-risk HPV types and CIN II,III, with an 87.0% positive predictive value and a 95.7% negative predictive value. In 226 women with ASCUS on repeated Pap smears, a positive test for high-risk HPV types had a 85.7% sensitivity and a 97% specificity for CIN II,III. In 277 patients with LGSIL on repeated Pap smears, a positive test for high-risk HPV types had an 88.2% sensitivity and a 94.7% specificity for CIN I,II. Reserving colposcopy examination for women who were positive for high-risk HPV types would have reduced the number of referrals for colposcopy to 24.6% and maintained a sensitivity of 87.0% for CIN II,III. A positive hybrid capture test for high-risk HPV types was highly sensitive and specific for the presence of CIN II,III in patients with ASCUS and LGSIL on repeated Pap smears. We believe that improved methodology will eventually enable more selective colposcopy referrals without affecting patient safety among these women.
    Gynecologic Oncology 11/2000; 79(2):177-80. DOI:10.1006/gyno.2000.5929 · 3.69 Impact Factor
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    ABSTRACT: Loop electrosurgical excision of the transformation zone (LEETZ) was recently associated with relatively high failure rates. We evaluated whether the combination of LEETZ with laser vaporization is superior to LEETZ alone in reducing the rates of recurrent abnormal cytology and residual disease. The study population included 426 women with histologic diagnosis of cervical intraepithelial neoplasia (CIN) 2-3, of whom 289 (study group) were treated by LEETZ followed by laser vaporization of the crater base and walls and 137 (control group) were treated by LEETZ alone. All women were followed scrupulously at regular intervals for recurrent abnormal cytology and residual disease. The mean follow-up periods were 43 and 59 months for the study and control groups, respectively. Both groups were derived from the same community and were similar in epidemiologic characteristics and disease severity. Although the incidence of positive surgical margins was similar in both groups (10.4 and 9.5% for the study and control groups, respectively), recurrent abnormal cytology (10.2% vs 5.5%, P = 0.07) and histologic residual disease (21.4% vs 0%, P = 0.05) were more frequent among women in the control group. This applied to women with both negative and positive surgical margins. Both study and control women with positive surgical margins, especially at the endocervix, were at higher risk for recurrence. The addition of laser vaporization to LEETZ may improve outcome of both women with positive margins and women with negative margins. Our results support conservative management for all treated women, regardless of cone margin status.
    Gynecologic Oncology 08/2000; 78(1):47-51. DOI:10.1006/gyno.2000.5825 · 3.69 Impact Factor
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  • I G Ron, H Ron, Y Lerman
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    ABSTRACT: Three cases of fatal extrapulmonary neoplasms among asbestos-exposed power plant workers are described. These cases add to the growing evidence for a causal relationship between asbestos exposures and extrapulmonary neoplasms.
    International journal of occupational and environmental health 10/1999; 5(4):304-6. DOI:10.1179/oeh.1999.5.4.304 · 1.10 Impact Factor
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    ABSTRACT: We study the effect of discreteness on various models for patterning in bacterial colonies (finite-size effect). We present two types of models to describe the growth of the bacterial colonies. The first model we present is the Communicating Walkers model (CWm), a hybrid model composed of both continuous fields and discrete entities -- walkers, which are coarse-graining of the bacteria. The coarse-graining might amplify the discreteness inherent to the biological system. Models of the second type are systems of reaction diffusion equations, where the branching of the pattern is due to non-constant diffusion coefficient of the bacterial field. The diffusion coefficient represents the effect of self-generated lubrication fluid on the bacterial movement. The representation of bacteria by a density field neglect their discreteness altogether. We implement the discreteness of the bacteria by introducing a cutoff in the growth term at low bacterial densities. We demonstrate that...
    Fractals 08/1999; 7(3). DOI:10.1142/S0218348X99000244 · 0.63 Impact Factor
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    ABSTRACT: To evaluate the effectiveness of a multidisciplinary approach to spinal cord compression (SCC) in accordance with prospective protocol, providing a uniform approach to diagnosis, decision making concerning optimal treatment modality in any particular case of SCC, treatment performance and evaluation of treatment results. The SCC patients treated by radiation therapy are described. Patients with SCC were examined and treated by a multidisciplinary team consisting of a neurologist, radiologist, oncologist, orthopedic surgeon, and neurosurgeon. Seventy-nine patients for whom radiation was recommended received a 30 Gy radiation dose to a compression-causing mass and course of high dose dexamethasone. Three fractions of 5 Gy and 5 fractions 3 Gy each were delivered by Co60 or 8 MV photon beam in 12 days. Treatment outcome was essentially evaluated by ambulation capabilities which were considered to be the main problem of SCC. Changes in other neurologic motor, sensory and autonomic disturbances were also evaluated. Seventy-two percent of the patients were already non-ambulatory at diagnosis. The first symptom was motor deficiency in only 33% of them while in all other cases it was pain. Ambulation capability was the main prognosticator of treatment outcome; 90% of patients who were ambulatory before treatment remained so while 33% of the non-ambulatory patients regained their ability to walk. The grade of motor disturbance was also an important variable: among the non-ambulatory patients, 50% of the paretic but only 14% of the plegic ones became ambulatory. Overall, 51% of the study patients were ambulatory after undergoing radiation. The ambulatory state after treatment was the main predictor for survival. Close cooperation of a multidisciplinary team in diagnosis and treatment according to the above protocol enabled the achievement of good results of radiation treatment in SCC. Early diagnosis and early treatment should further enhance therapeutic outcome.
    Journal of Neuro-Oncology 04/1999; 42(1):85-92. DOI:10.1023/A:1006124724858 · 2.79 Impact Factor
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    ABSTRACT: A phase II study of carboplatin and etoposide as salvage polychemotherapy in metastatic, infiltrating breast carcinoma was carried out with 25 multiply pretreated patients. Six of 25 patients (24%) had a partial response that lasted an average of 3.5 months; of the six responders, four had undergone either four or five previous chemotherapeutic treatments. Eight of 25 patients (32%) had stable disease, and 11 (44%) manifested disease progression. The median survival from time of entry to the salvage protocol was 8 months. There were treatment responses in lung, chest wall, liver, and skeleton. The most common side effects were leukopenia (68% of 25 patients), thrombocytopenia (56%), anemia (40%), fever (28%), and weakness (16%). Carboplatin combined with etoposide may be an effective and tolerable salvage regimen in advanced breast cancer.
    American Journal of Clinical Oncology 03/1999; 22(1):35-7. DOI:10.1097/00000421-199902000-00009 · 2.61 Impact Factor
  • T H Vishne, I G Ron
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    ABSTRACT: The authors report the cases of two patients in whom strontium-89 (89Sr) was used to relieve diffuse metastatic bone pain. The type of cancer involved, thymic carcinoid tumor, is itself rare and the risk of its metastasizing to the bone is very low. Both patients showed a measure of response to treatment, suggesting that this analgesic method has value for some patients. The marked benefit of one patient for a total of 9 months was attributable to two 89Sr injections, whereas the other patient improved for only 5 weeks after one injection.
    American Journal of Clinical Oncology 01/1999; 21(6):602-4. DOI:10.1097/00000421-199812000-00014 · 2.61 Impact Factor
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    ABSTRACT: A growing body of data suggests that cancer therapy may be improved and toxicity reduced by administration of antineoplastic agents and cytokines at carefully selected times of the day. The time-dependent effects of each of the drugs have been documented, but not their mutual time dependencies. In the present studies we sought to determine the best time for granulocyte colony-stimulating factor (G-CSF) administration after carboplatin treatment. Carboplatin was injected in different groups of ICR mice at four different circadian stages for 5 consecutive days. Mice were synchronized with an alternation of 12 h of light (from 6:00 a.m. to 6:00 p.m.) and 12 h of darkness. After the last injection, peripheral WBCs of three mice from each group were counted every 4 h over a 24-h period. Bone marrow toxicity was estimated with the mean 24-h WBC count. The most severe leukopenia occurred in the group injected at 3:00 p.m. – 9 h after light onset. The second set of experiments evaluated the time-dependent effect of G-CSF when singly injected or given after carboplatin injections for 5 days only at 3:00 p.m. G-CSF was injected into various groups on days 8 and 9 at the same four different circadian stages. On the 10th day after the first injection, peripheral WBCs of three mice from each group were counted every 4 h over a 24-h period. Time-dependent effects were observed when G-CSF was injected as a single agent. When G-CSF was given at various times to the group with the most severe carboplatin-induced leukopenia, peripheral WBC count recovery was monitored at all injection times; it reached its highest level (exceeding even that of the control) when G-CSF was injected at 3:00 a.m. Dosing times of both chemotherapy and growth factor are relevant for optimization of carboplatin's hematologic tolerability.
    Cancer Chemotherapy and Pharmacology 05/1998; 42(2):135-141. DOI:10.1007/s002800050796 · 2.57 Impact Factor
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    ABSTRACT: BACKGROUND AND METHODS: The cases of 245 patients diagnosed during 1980-1989 with stage I endometrial carcinoma were retrospectively reviewed in order to assess the contribution of lymph node sampling (LNS) to both course of treatment and outcome. The 183 women treated by gyneco-oncologic surgeons had undergone the standard surgical procedure of total abdominal hysterectomy (TAH), bilateral salpingo-oophorectomy (BSO) and pelvic lymph node sampling (LNS). Sixty-two other women, treated by gynecologists, received only TAH and BSO. Of women who had received TAH+BSO+LNS, 105 (57.4%) were referred for adjuvant radiotherapy on the basis of one or any combination of high grade histology (G2 or G3), myometrial invasion to a depth of 50% or more and LNS positivity. Of the group who had not had LNS, 37 (59.7%) likewise received adjuvant radiotherapy but on the bases of histology and/or depth of invasion. RESULTS AND CONCLUSIONS: Recurrence and survival over a mean follow-up period of 7.5 years (range 5-15 years) showed no significant differences between the patients who underwent LNS and those who did not. Of 43 recurrences, six were among 'low risk' women (those with both minimal invasion and low grade histology), suggesting a special need among this group for the additional staging information which LNS may provide.
    Acta Obstetricia Et Gynecologica Scandinavica 03/1998; 77(3):347-50. DOI:10.1080/j.1600-0412.1998.770318.x · 1.99 Impact Factor
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    ABSTRACT: This study provides the first quantitative indication of the limits of sensitivity of a bone scan with technetium (99Tc-MDP) in detecting skeletal metastases and thereby also helps to explain the fact that bone scans may be negative when metastases are present in the bone marrow. Since 99Tc-MDP remains the least noxious and most widely used isotope for bone scanning, these results have direct clinical relevance in the evaluation of patients with solid tumors and possible metastatic spread.
    Oncology Reports 01/1998; 6(1):185-8. DOI:10.3892/or.6.1.185 · 2.19 Impact Factor
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    ABSTRACT: Standard staging and therapeutic approach to endometrial cancer involves lymph node sampling (LNS) at the time of total abdominal hysterectomy (TAH) and bilateral salpingo-oophorectomy (BSO). Lymphadenectomy prolongs time of surgery and increases the risk of morbidity; where other predictors are available, it may not contribute important supplementary information. 185/247 women with stage I endometrial carcinoma underwent the standard surgery while 62 underwent TAH+BSO. Recurrence and survival were monitored for a mean of 6.5 years and retrospectively reviewed: the rates for groups with and without known lymph node status were alike [13.5% (25/185) recurrence for the former and 12.9% (8/62) for the latter, and 5-year survival rates of 75.7% (140/185) for the former and 74.2 (46/62) for the latter]. Myometrial invasion and histological grade appeared to have been highly accurate predictors without lymph node information. Because information on histological grade is available early and is highly predictive, its use could be incorporated into a revised management algorithm for stage I endometrial cancer which would depend upon ensuring lymphadenectomy for women with low grade histopathology and omitting it for those with high grades on the grounds that no further information is necessary to act appropriately.
    Oncology Reports 09/1997; 4(5):1055-8. DOI:10.3892/or.4.5.1055 · 2.19 Impact Factor
  • European Journal of Cancer 07/1997; 33(8):1334-1335. DOI:10.1016/S0959-8049(97)00083-X · 4.82 Impact Factor
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    ABSTRACT: To assess any difference in the incidence of alopecia during treatment and of skull metastases during follow-up among breast cancer patients undergoing scalp cooling during chemotherapy and those treated at ambient temperatures. A series of 35 breast cancer patients receiving adjuvant chemotherapy were consecutively assigned either to a scalp cooling regimen (19 patients) or to an ambient temperature regimen (16 patients). Hypothermia was administered with electrically cooled caps (SCS II: Amit Technology, Jerusalem) for 1 h after treatment. A significant difference (P = 0.014) was detected in the incidence of alopoecia: 48% (9 patients) of those who had undergone cooling suffered alopoecia, while 81% (13 patients) of the group who had not undergone cooling lost scalp hair. Patient comfort levels were high. Follow-up (median time 14 months) has disclosed no scalp metastases. The implementation of routine scalp hypothermia as part of adjuvant chemotherapy treatment, especially in cancers without tendencies to bone metastases, should be seriously considered.
    Supportive Care Cancer 04/1997; 5(2):136-8. DOI:10.1007/BF01262571 · 2.50 Impact Factor

Publication Stats

334 Citations
110.61 Total Impact Points

Institutions

  • 1992–2002
    • Tel Aviv University
      • • Department of Oncology
      • • Department of Human Molecular Genetics and Biochemistry
      Tel Aviv, Tel Aviv, Israel
  • 1985–2002
    • Tel Aviv Sourasky Medical Center
      • Division of Oncology
      Tell Afif, Tel Aviv, Israel
  • 1996–1997
    • Bar Ilan University
      • Department of Physics
      Gan, Tel Aviv, Israel