I G Ron

Tel Aviv University, Tel Aviv, Tel Aviv, Israel

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Publications (34)77.76 Total impact

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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. · 2.55 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. · 5.06 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. · 0.78 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. · 2.87 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. · 3.93 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. · 3.93 Impact Factor
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    Branching in Nature: Dynamics and Morphogenesis of Branching Structures, from Cell to River Networks. Springer-Verlag. 04/2000;
  • 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. · 1.18 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; · 0.36 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. · 2.55 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. · 2.55 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. · 1.85 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. · 2.30 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. · 2.65 Impact Factor
  • M J Inbar, I G Ron
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    ABSTRACT: While cancer is a leading cause of death in women of childbearing age, its simultaneous occurrence with pregnancy is uncommon, with a reported incidence of 0.07%-0.1% (1). The malignant neoplasms complicating pregnancy are those most frequently seen in young women: lymphoma, leukemia, melanoma and cancers of the breast, cervix, ovary, thyroid and colon (2, 3). Breast cancer, the most common of them all and, in many areas of the world, the most frequent cause of cancer deaths in women, is also the type of cancer most likely to be seen in pregnancy or lactation (4). This cancer, in association with pregnancy, occurs in three of every 10,000 pregnancies and in 3% of all breast cancer patients (1, 5). Except for delay in diagnosis, no convincing data exist that pregnancy per se adversely influences the prognosis or biology of maternal cancer, and this includes breast cancer as well. There are no firm data which show that there is a greater likelihood of reactivation of cancer during pregnancy. Conversely, there are only a few reports in the literature which indicate that cancer adversely affects pregnancy (6). It is well known, however, that a delay in diagnostic and therapeutic interventions are potentially deleterious to both mother and fetus.
    Acta Obstetricia Et Gynecologica Scandinavica 10/1996; 75(8):765-7. · 1.85 Impact Factor
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    ABSTRACT: The therapeutic performance, effect on quality of life and cost effectiveness of an orally administered medication in a home care setting were examined prospectively in a group of 61 patients presenting with advanced colorectal carcinoma. A regimen of daily ftorafur capsules (370 mg/m2) and leucovorin tablets (20 mg/m2) was offered to 35 symptomatic patients with poor performance status; the standard in-hospital i.v. protocol of 5-fluouracil and leucovorin was given to the remaining 26 patients. Follow-up and survival analysis indicated that there was no compromise in survival associated with home care and oral chemotherapy. There were statistically significant advantages in terms of reduced toxicity and improved Karnofsky performance status in this group. Home care was approximately 70% less expensive. A home treatment program based on oral ftorafur may be the most desirable option for all patients with advanced colorectal carcinoma.
    Anti-Cancer Drugs 09/1996; 7(6):649-54. · 2.23 Impact Factor
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    ABSTRACT: Two patients with Kaposi's sarcoma developing in an area of lymphedematous arm postmastectomy are reported. The Kaposi's sarcoma occurred after latent periods of 26 and 7 years following radical and modified-radical mastectomy, respectively, in the edematous tissue of the ipsilateral arm. The cutaneous nodules were purple in color and ranged in size from a few millimeters to > 1 cm in diameter. The results of routine laboratory tests were all within normal limits. Human immunodeficiency virus (HIV) antibody and cytomegalovirus (CMV) antigen, using enzyme-linked immunosorbent assay (ELISA), were negative.
    American Journal of Clinical Oncology 03/1996; 19(1):87-90. · 2.55 Impact Factor
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    ABSTRACT: Lymphocytic cytoplasm from individuals with malignant disease, and from those without, differ in such a way as to be diagnostic both of malignancy generally and of specific types of cancer. Mitogenic stimulation of lymphocytes by phytohaemagglutinin (PHA) and antigenic stimulation by encephalitogenic factor (EF) and certain specific tumour-associated antigens, provokes changes in the structure of the cytoplasmic matrix (SCM) which are detectable upon fluorescence polarisation. The degree of change is quantifiable both by calculating the polarisation ration (PR, polarisation before and after stimulation) and the relative ratio (RRSCM, the ratio between the polarisation obtained after exposure to EF [PEF] and to the polarisation measured after exposure to PHA [PPHA]). A new tumour-associated antigen specific for breast cancer, CaBr, was tested for its diagnostic efficacy in comparison with that of EF, by prospectively testing blood samples from 138 consecutive women with suspicious breast masses. The previously known discriminatory power (sensitivity 60.7% and specificity 90.7%) of the polarisation-derived RRSCM was reconfirmed. However, the RR'SCM (the new ratio using CaBr instead of EF), was significantly more sensitive (77.4%; P < 0.01) and specific (94.4%) than the RRSCM in detecting breast cancers. The polarisation changes in the cytoplasmic matrix after stimulation by CaBr alone suggest the best discriminatory power (sensitivity 90.5% and specificity 94.4%) between cancerous and non-cancerous patients.
    European Journal of Cancer 06/1995; 31A(6):917-20. · 5.06 Impact Factor
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    ABSTRACT: A case of clear cell chondrosarcoma of the rib in a 30-year-old man is described. The tumor developed at the site of repetitive low-impact trauma (on the arm of a wheelchair) over a period of 24 years. An association between chondrosarcoma and external trauma has not been previously reported. Chondrosarcoma has been described in previously irradiated bone and in Paget's disease. In both these examples there is an increase in new bone formation associated with necrosis of bone and increased resorption of bone, respectively. A possible mechanism in our case is increased new bone formation elicited by repeated microfractures of trabeculae of rib bone.
    American Journal of Clinical Oncology 03/1995; 18(1):87-9. · 2.55 Impact Factor
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    ABSTRACT: Fourteen patients with advanced ovarian cancer who failed chemotherapy received a long-acting LHRH agonist. All the patients had been previously operated on and all had received at least one regimen of chemotherapy. Duration of decapeptyl administration was between 1 month and 28 weeks. There were no complete or partial responses. Eight patients (57%) had disease stabilization with a median progression-free interval of 14 weeks (range 4-28 weeks). All other patients developed a clear progressive cancer after the first injection of LHRH agonist. Three of these patients are still alive and receiving other forms of chemotherapy (median follow-up after the end of LHRH treatment was 11.5 months). The regimen was well tolerated with only mild toxicity observed (hot flushes in 2 patients). Although D-Trp-6-LHRH (Decapeptyl) was well tolerated, it had insignificant activity in treating patients with epithelial cancer that was resistant or relapsed after first-line platinum-based chemotherapy.
    Cancer Investigation 02/1995; 13(3):272-5. · 2.24 Impact Factor