Angular momentum generation in nuclear fission.

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4-12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18.

Shape Coexistence at Zero Spin in

The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Multifaceted Quadruplet of Low-Lying Spin-Zero States in

A search for shape isomers in the ^{66}Ni nucleus was performed, following old suggestions of various mean-field models and recent ones, based on state-of-the-art Monte Carlo shell model (MCSM), all considering ^{66}Ni as the lightest nuclear system with shape isomerism. By employing the two-neutron transfer reaction induced by an ^{18}O beam on a ^{64}Ni target, at the sub-Coulomb barrier energy of 39 MeV, all three lowest-excited 0^{+} states in ^{66}Ni were populated and their γ decay was observed by γ-coincidence technique. The 0^{+} states lifetimes were assessed with the plunger method, yielding for the 0_{2}^{+}, 0_{3}^{+}, and 0_{4}^{+} decay to the 2_{1}^{+} state the B(E2) values of 4.3, 0.1, and 0.2 Weisskopf units (W.u.), respectively. MCSM calculations correctly predict the existence of all three excited 0^{+} states, pointing to the oblate, spherical, and prolate nature of the consecutive excitations. In addition, they account for the hindrance of the E2 decay from the prolate 0_{4}^{+} to the spherical 2_{1}^{+} state, although overestimating its value. This result makes ^{66}Ni a unique nuclear system, apart from ^{236,238}U, in which a retarded γ transition from a 0^{+} deformed state to a spherical configuration is observed, resembling a shape-isomerlike behavior.

Significance of lymph node sampling in epithelial carcinoma of the ovary.

From 1979 to 1984, 127 patients operated on for ovarian cancer underwent pelvic, para-aortic, or pelvic and para-aortic lymph node sampling. Forty-seven patients proved to be stage I(14 IA and 33 IC), 14 were stage II(3 IIA, 8 IIB, and 3 IIC), 58 were stage III (7 IIIA, 13 IIIB, and 38 IIIC), and 8 were stage IV. Positive lymph nodes were found in 4.2% of patients at stage I, 35.7% at stage II, 41.3% at stage III, and 87.5% at stage IV. With regard to grading, positive lymph nodes were found in 4.4% of G1, in 21.6% of G2, and in 49.1% of G3. A significant increase in survival (P = 0.04) was found for patients classified as stage IIIC only according to lymph node involvement compared to patients in peritoneal stage IIIC with positive lymph nodes (3-year survival: 46% vs 12%). A small increase in survival was observed for N- patients compared to N+ patients, at both stage III and IV, even with same residual tumor size, but the difference is not statistically significant. All other things being equal, because the prevalence of lymph node positivity depends closely on the number of lymph nodes removed and examined (OR = 3.9 for >10 lymph nodes removed compared to 1-5 lymph nodes removed), lymph node sampling does not seem to be a reliable method for evaluating the retroperitoneal status. With regard to the therapeutic role of systematic lymphadenectomy, few data in literature are available and, most important, are not derived from experimental studies. Probably, only randomized studies with a large number of patients will provide useful answers.

Intraperitoneal carboplatin with or without interferon-alpha in advanced ovarian cancer patients with minimal residual disease at second look: a prospective randomized trial of 111 patients. G.O.N.O. Gruppo Oncologic Nord Ovest.

From June 1990 to October 1994, 111 advanced ovarian cancer patients with minimal (less than 2 cm) residual disease after platinum-based front-line chemotherapy and second-look laparotomy entered a cooperative randomized study aimed at evaluating the effectiveness and the toxicity of the addition of interferon-alpha2 to carboplatin, both intraperitoneally (ip) administered. Patients were randomized to receive either 3 courses of ip Carboplatin 400 mg/m2 Day 1 q 28 days (54 pts) (CBDCA) or ip interferon-alpha 25 x 10(6) U Day 1 + ip carboplatin 400 mg/m2 Day 2 q 28 days (57 pts) (CBDCA + IFN). Patients treated with interferon experienced more severe (WHO grade 3-4) leukopenia (28% vs 17.1%) and anemia (14% vs 4.2%). Fever (P = 0.000) and flu-like syndrome (P = 0.02) were significantly more frequent in the combination arm. No difference in gastroenteric, neurologic, or renal toxicity was observed. At a median follow-up time of 13 months (range 1-72) 71 patients showed a disease progression (31 CBDCA, 40 CBDCA + IFN) and 44 patients died (21 CBDCA, 23 CBDCA + IFN). Median progression-free survival was 11 months in the CBDCA group and 10 months in the CBDCA + IFN arm. Median survival was 22 and 29 months in CBDCA and CBDCA + IFN arm, respectively. In conclusion, intraperitoneal interferon-alpha does not seem to improve the results achievable with intraperitoneal carboplatin in this subset of patients, while the toxicity and the costs of the combination are consistently higher than with chemotherapy alone.

High-dose versus low-dose cisplatin in combination with cyclophosphamide and epidoxorubicin in suboptimal ovarian cancer: a randomized study of the Gruppo Oncologico Nord-Ovest.

PURPOSE: The aim of the study was to compare high-versus low-dose cisplatin in combination with cyclophosphamide and epidoxorubicin as primary chemotherapy for suboptimal stage III and IV ovarian cancer. PATIENTS AND METHODS: One hundred forty-five patients were randomized to receive six courses of cisplatin 50 or 100 mg/m2 plus epidoxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2. The two treatment arms were well balanced; all patients had greater than 2 cm and 37.2% had greater than 5 cm of residual disease; 29.6% had stage IV disease. RESULTS: Patients in the high-dose arm received a double dose-intensity and double total dose of cisplatin. The high-dose regimen induced significantly more episodes of leukopenia (47.8% v 32.8%, P = .05), thrombocytopenia (21.7% v 3.2%, P = .003), anemia (37.6% v 12.5%, P = .002), nephrotoxicity (six v one patient), and neurotoxicity (30.4% v 6.3%, P = .002). There were no significant differences in efficacy in terms of clinical response rate (high-dose 57.5% v low-dose 61.1%), pathologic complete response (CR) (9.6% v 18.1%), median survival times (29 v 24 months), and median progression-free survival (18 v 13 months). CONCLUSION: This study shows that doubling the dose-intensity and total dose of cisplatin in combination with epidoxorubicin and cyclophosphamide has significant toxic effects and does not improve clinical outcome in patients with suboptimal ovarian cancer.

The effectiveness of a pendulum swing for the development of leg strength and counter-movement jump performance.

Various training devices have been developed to facilitate 'plyometric' training, one such device being the 'pendulum swing'. To assess the effectiveness of the pendulum swing, the results of a 3 week training programme using a combination of pendulum swing and weight-training exercises were compared to those of a weight-training programme. Subjects were assigned to one of two groups (n = 9) for weight-training only or for combined pendulum and weight-training. Both groups performed the same number of exercise repetitions. Measurements of isometric knee and hip extension-flexion, 1-RM squat weight, maximum jump height and power for a counter-movement jump were taken pre-training, 2 days after the end of the programme and 2 weeks after the end of the programme. The data were analysed using two-way MANOVA and MANCOVA techniques. Both methods showed significant (P < 0.05) increases in knee and hip extension strength. Hip and knee flexion strength increased only for the weight-trained group. Counter-movement jump height increased for both groups (weight-trained, P < 0.05; combined, P < 0.01). Maximum power increased only for the combined group (P < 0.05). When the pre-training scores were used as a covariate, the weight-trained group showed a greater increase in hip flexion and extension strength and knee flexion strength than the combined training group (P < 0.05). The combined group showed the greatest increase in knee extensor strength. It is concluded that the pendulum system induces a training effect which could be used to supplement weight-training for improving vertical jump performance.

Ifosfamide and etoposide salvage treatment in advanced ovarian cancer.

Twelve FIGO stage III-IV ovarian cancer patients progressing or relapsing after primary cisplatin-containing combination chemotherapy were treated with ifosfamide and etoposide. Only patients with clinically evaluable disease entered the trial. The 12 patients received a median number of 3 courses (range 1-6). No complete or partial response and two disease stabilizations were observed. Ten patients progressed on therapy. The combination of ifosfamide and etoposide does not appear to be an effective salvage treatment for advanced ovarian cancer.

Intraperitoneal cytosine arabinoside administered in sequence with systemic cisplatin, doxorubicin, and cyclophosphamide in advanced ovarian cancer.

After standard management of stage III-IV ovarian cancer patients by surgical reduction of tumor mass and subsequent cisplatin-based combination chemotherapy, eradication of residual intraabdominal disease remains a major clinical problem. In an effort to increase response to therapy without adding marrow toxicity, after laparotomy, 21 stage III-IV ovarian cancer patients were treated with systemic chemotherapy comprising cisplatin, doxorubicin, and cyclophosphamide (PAC) on Day 1 followed by intraperitoneal (ip) cytosine arabinoside (Ara-C) on either Day 8 or 14, every 28 days. Ara-C, an S-phase-specific drug, was administered ip to exploit the pharmacologic advantage of an ip regimen at a time when a possible PAC-induced recruitment of cells into the proliferative pool could further maximize cell kill. Kinetic features of ovarian neoplastic cells recovered from peritoneal washings were monitored during treatment by measurement of the thymidine labeling index (TLI): data from four patients indicate that there is an increase in proliferating cells on Days 8 and 14 after PAC treatment. Toxicity of treatment was acceptable. Although 95% of evaluable patients had more than 2 cm of residual disease, response was observed in 47% of patients. The therapeutic potential of this regimen should be tested in patients with small-volume disease after debulking surgery.

The role of induction chemotherapy in inoperable ovarian cancer.

Thirty patients with bulky advanced ovarian cancer surgically not resectable, received combination chemotherapy (median of 4.1 cycles; range, 3-7) including cisplatin or carboplatin, followed by a second surgical effort. Clinical CR + PR was observed in 24/30 (80%) patients after chemotherapy. Our study deals only with these 24 patients, and the 6 patients who did not respond to chemotherapy are not part of this report. At debulking, 7/24 (29.1%) patients had a complete macroscopic resection; 9/24 (37.5%) patients had a partial resection (residual tumor less than 2 cm). These data suggest that debulking is feasible and successful after chemotherapy containing cisplatin or its derivative. Overall median survival from diagnosis was 18.9 months; the 3-year survival rate was 28%. Median progression-free survival from diagnosis was 13.5 months. The results observed in our study indicate that the use of induction chemotherapy can play an important role in increasing the chances of optimal debulking in patients presenting with unresectable ovarian cancer.

[Carcinoma of the breast: information on tumoral disease in hospitalized patients]. / Carcinoma della mammella: l'informazione sulla malattia tumorale nelle pazienti ospedalizzate.

Information on their disease, received from 100 patients hospitalized for breast cancer, is assessed. Through analysis of the replies to a questionnaire on information obtained before and after treatment, it emerges that 60% of the patients had received information about the disease and that 45% knew that the diagnosis was cancer. The study confirms the importance for physicians to use uniform language, consistent with the personality of each patient.

Experimental infections of the musculoskeletal system: evaluation with MR imaging and Tc-99m MDP and Ga-67 scintigraphy.

Acute osteomyelitis, soft-tissue infection, or both were experimentally produced in 38 New Zealand white rabbits, and three-phase technetium-99m methylene diphosphonate, gallium-67, and magnetic resonance (MR) images were obtained 7 or 14 days after infection. There was no significant difference between radionuclide studies and MR images in the detection of osteomyelitis, but MR imaging was significantly more sensitive (100% vs. 69%; P less than .01) in the detection of soft-tissue infection. In addition, cellulitis could not be distinguished from soft-tissue abscess on radionuclide studies, whereas MR imaging was 92% accurate in depicting soft-tissue abscesses. Further research is necessary to determine how to relate these findings to true human clinical situations.

Congenital pleural effusion: prenatal ultrasonic diagnosis and therapeutic management.

A case of fetal pleural effusion detected by ultrasound at 33 weeks of gestation is described.