THERMOREVERSIBLE CROSS-LINKING OF RUBBER COMPOUNDS: FROM PROOF-OF-CONCEPT TOWARD AN INDUSTRIAL PROCESS

It is demonstrated that the concept of thermoreversible cross-linking of functionalized maleic anhydride grafted ethylene–propylene (EPM-g-MA) rubber using Diels–Alder chemistry is limited neither to laboratory scale using a solvent route nor to gum rubber. The use of an internal mixer is the first step toward an industrial process, since it greatly reduces the processing time and allows for a solventless process for the furan-functionalization and subsequent bismaleimide cross-linking of EPM rubber. Practical rubber compounds were prepared by mixing thermoreversibly cross-linked EPM with carbon black and mineral oil in the same batch mixer. This resulted in reinforcement of the rubber without affecting the thermoreversible character of the cross-linking. The pendant furan groups of the (non)cross-linked EPM-g-furan interact with the carbon black filler. Finally, crystalline EPM rubber compounds were prepared, which show excellent material properties and property retention over multiple reprocessing cycles.

Effect of ammonia in cigarette tobacco on nicotine absorption in human smokers

The function of ammonia as tobacco additive is subject of scientific debate. It is argued that ammonia, by increasing the proportion of free nicotine, increases the absorption of nicotine in smokers. As a result of the addition of ammonia to cigarettes, smokers get exposed to higher internal nicotine doses and become more addicted to the product. On two occasions, the nicotine absorption in blood was measured after smoking a commercial cigarette of either brand 1 or brand 2, which differed 3.8-fold in ammonium salt content. Using a standardized smoking regime (six puffs, 30 s puff interval, 7 s breath hold before exhalation), 51 regular smokers smoked brand 1 (Caballero Smooth Flavor; 0.89 mg ammonium per gram tobacco) and brand 2 (Gauloise Brunes; 3.43 mg ammonium per gram tobacco). Puff volumes and cardiovascular parameters were monitored during and following smoking, respectively. Measurement of serum nicotine level in the blood samples collected over time following smoking of the two brands, showed that total amount of nicotine absorbed did not differ between the two brands. Present results demonstrate that smoking tobacco containing a higher amount of the tobacco additive ammonium does not increase the absorption of nicotine in the smoker's body.

Subsurface valleys and geoarcheology of the eastern sahara revealed by shuttle radar

The shuttle imaging radar (SIR-A) carried on the space shuttle Columbia in November 1981 penetrated the extremely dry Selima Sand Sheet, dunes, and drift sand of the eastern Sahara, revealing previously unknown buried valleys, geologic structures, and possible Stone Age occupation sites. Radar responses from bedrock and gravel surfaces beneath windblown sand several centimeters to possibly meters thick delineate sand- and alluvium-filled valleys, some nearly as wide as the Nile Valley and perhaps as old as middle Tertiary. The now-vanished major river systems that carved these large valleys probably accomplished most of the erosional stripping of this extraordinarily flat, hyperarid region. Underfit and incised dry wadis, many superimposed on the large valleys, represent erosion by intermittent running water, probably during Quaternary pluvials. Stone Age artifacts associated with soils in the alluvium suggest that areas near the wadis may have been sites of early human occupation. The presence of old drainage networks beneath the sand sheet provides a geologic explanation for the locations of many playas and present-day oases which have been centers of episodic human habitation. Radar penetration of dry sand and soils varies with the wavelength of the incident signals (24 centimeters for the SIR-A system), incidence angle, and the electrical properties of the materials, which are largely determined by moisture content. The calculated depth of radar penetration of dry sand and granules, based on laboratory measurements of the electrical properties of samples from the Selima Sand Sheet, is at least 5 meters. Recent (September 1982) field studies in Egypt verified SIR-A signal penetration depths of at least 1 meter in the Selima Sand Sheet and in drift sand and 2 or more meters in sand dunes.

Radium-223 in the treatment of metastatic hormone refractory prostate cancer (HRPC): Results from a randomized, placebo-controlled, phase II study

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Background: The alpha emitter radium-223 is a bone-seeking radionuclide studied as a novel treatment for patients with HRPC and bone metastases. Ra-223 showed minimal toxicity in a phase 1 study (Nilsson S, et al., Clin Cancer Res 2005;11 (12): 4451–59). Here we present outcome data from a randomised phase II study. Methods: Patients with HRPC and bone pain requiring external beam radiotherapy were randomized to treatment with 4 injections of either Ra-223 (50 kBq/kg b.w.) or saline (placebo) every 4 weeks. The primary endpoints were change in bone-alkaline phosphatase (ALP) levels from baseline to 4 weeks after last injection (previously reported (Bruland ØS, et al. Clin Cancer Res 2006;12:6250s-57s), and time to occurrence of Skeletal Related Events (SREs). Secondary endpoints included toxicity, PSA progression and overall survival. Results: 33 patients were randomised to Ra-223 and 31 to placebo. The two groups were well balanced with respect to standard prognostic factors. Mild, transient haematological toxicity was seen after Ra-223. Long term toxicity was not observed. SAEs were observed in 8 patients in the Ra-223 group versus 14 in the placebo group. Based on intention to treat analysis, the median time to PSA progression was 26 versus 8 weeks (p=0.047) for Ra-223 versus placebo, respectively. The median time to first SRE was 28 versus 26 weeks (p= 0.164). The median overall survival was 65.3 weeks versus 46.4 weeks (p = 0.066). The hazard ratio for overall survival, adjusted for baseline PSA, albumin, LDH and performance status was 2.11 (95 % CI: 1.08 - 4.13, p=0.029). At 18 months, 15 (45%) versus 8 (26%) patients patients were still alive. Conclusions: Alpharadin was extremely well tolerated, with minimal myelotoxicity, and with encouraging evidence of efficacy. Larger clinical trials are warranted to study the impact of Alpharadin on the prevention of SREs and on overall survival in HRPC. The bone targeting properties of Alpharadin, may also be applicable to the treatment of skeletal metastasis from other primary cancers.

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Long-term follow-up confirms a survival advantage of the paclitaxel-cisplatin regimen over the cyclophosphamide-cisplatin combination in advanced ovarian cancer

Two independent and consecutive randomized clinical trials, conducted by the American Gynecological Oncology Group and by an European-Canadian Intergroup, have shown superiority, in clinical response rate, progression-free survival, and overall survival, of a cisplatin-paclitaxel regimen over cisplatin-cyclophosphamide given as first-line chemotherapy for women with advanced epithelial ovarian cancer. The results of these studies, published with a median follow-up of about 3 years, have been updated with a 6.5-year follow-up: In each case, an 11% absolute gain in survival favoring the paclitaxel arm is shown; this advantage remains both statistically and clinically significant and supports a role for paclitaxel in frontline chemotherapy for advanced ovarian cancer.

Long-term follow-up confirms a survival advantage of the paclitaxel–cisplatin regimen over the cyclophosphamide–cisplatin combination in advanced ovarian cancer

Two independent and consecutive randomized clinical trials, conducted by the American Gynecological Oncology Group and by an European–Canadian Intergroup, have shown superiority, in clinical response rate, progression-free survival, and overall survival, of a cisplatin–paclitaxel regimen over cisplatin–cyclophosphamide given as first-line chemotherapy for women with advanced epithelial ovarian cancer. The results of these studies, published with a median follow-up of about 3 years, have been updated with a 6.5-year follow-up: In each case, an 11% absolute gain in survival favoring the paclitaxel arm is shown; this advantage remains both statistically and clinically significant and supports a role for paclitaxel in frontline chemotherapy for advanced ovarian cancer.

Stem cell factor and interleukin-4 increase responsiveness of mast cells to substance P

The response of mast cells (MC) to non-IgE-mediated stimulation is critically dependent on the population of MC examined. The neuropeptide Substance P (SP) has been reported to activate connective tissue-type MC (CTMC), while mucosal MC (MMC) are not activated by SP. We examined the effect of stem cell factor (SCF) plus interleukin-4 (IL-4) on SP-initiated activation of bone marrow-derived MC (BMMC). Mouse MC, derived from a culture of BM cells with IL-3, were subsequently treated with recombinant SCF plus IL-4 for 6 days. Responsiveness to SP was monitored measuring beta-hexosaminidase and lipid mediator release. Histochemical staining, histamine analysis, and granule protease expression were achieved to characterize the cells. In contrast to IL-3 grown cells, SCF/IL-4-exposed cells showed functional responsiveness to release beta-hexosaminidase (42.25% +/- 1.46% at SP concentration of 100 microM) and produce leukotriene C(4) (LTC(4)) (7.4 +/- 1.5 ng/10(6) cells)/prostaglandin D(2) (PGD(2)) (2.0 +/- 0.3 ng/10(6) cells) upon stimulation by SP. The increase in sensitivity of the cells to SP was not due to differentiation into CTMC, as the cells remained heparin negative. Both SCF and IL-4 were needed because SCF or IL-4 alone were insufficient to keep cells viable after 3 to 4 days post coculture. SP-induced secretion from BMMC cultured in medium containing SCF plus IL-4 (25.76% +/- 1.83%) was higher in comparison with cells cultured with SCF plus IL-3 (8.85% +/- 0.68%).These findings indicate that temporal changes in cytokine expression can influence the sensitivity of MC to non-immunologic stimuli. Local cytokine production leading to an increase in MC responsiveness to SP and inducing secretion of granule content and lipid generation may, therefore, propagate and worsen inflammatory conditions.

Randomized intergroup trial of cisplatin-paclitaxel versus cisplatin-cyclophosphamide in women with advanced epithelial ovarian cancer: three-year results

BACKGROUND

A randomized trial conducted by the Gynecologic Oncology Group (GOG, study #111) in the United States showed a better outcome for patients with advanced ovarian cancer on the paclitaxel-cisplatin regimen than for those on a standard cyclophosphamide-cisplatin regimen. Before considering the paclitaxel-cisplatin regimen as the new "standard," a group of European and Canadian investigators planned a confirmatory phase III trial.

METHODS

This intergroup trial recruited 680 patients with broader selection criteria than the GOG #111 study and administered paclitaxel as a 3-hour instead of a 24-hour infusion; progression-free survival was the primary end point. Patient survival was analyzed by use of the Kaplan-Meier technique. Treatment effects on patient survival were estimated by Cox proportional hazards regression models. All statistical tests were two-sided.

RESULTS

The overall clinical response rate was 59% in the paclitaxel group and 45% in the cyclophosphamide group; the complete clinical remission rates were 41% and 27%, respectively; both differences were statistically significant (P =.01 for both). At a median follow-up of 38.5 months and despite a high rate of crossover (48%) from the cyclophosphamide arm to the paclitaxel arm at first detection of progression of disease, a longer progression-free survival (log-rank P =.0005; median of 15.5 months versus 11.5 months) and a longer overall survival (log-rank P =. 0016; median of 35.6 months versus 25.8 months) were seen in the paclitaxel regimen compared with the cyclophosphamide regimen.

CONCLUSIONS

There is strong and confirmatory evidence from two large randomized phase III trials to support paclitaxel-cisplatin as the new standard regimen for treatment of patients with advanced ovarian cancer.

Endometrial stromal sarcoma of the uterus: a clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 17 cases

Seventeen patients with endometrial stromal sarcoma (ESS) diagnosed between 1970 and 1996 were evaluated according to DNA ploidy, S-phase fraction (SPF), p53, and mdm-2 expression, as well as traditional clinical and pathologic prognostic factors, such as tumor stage, grade, and mitotic index. DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors. Flow cytometric DNA histograms were obtained from 16 patients. The patients ranged in age from 41 to 78 years (median, 57 years). Seven (41%) patients were premenopausal. Thirteen low-grade ESS were DNA diploid and had a low SPF. Of these, two overexpressed p53, while only one was mdm-2 positive. Among the four high-grade ESS we found one (25%) DNA diploid tumor and three (75%) DNA aneuploid tumors. Two (50%) had an SPF greater than 10%, three (75%) were p53-positive, and two (50%) overexpressed mdm-2. During the observation period, nine (53%) patients (five with low-grade and four with high-grade tumors) died of disease. The 5-year survival rate for patients with low-grade ESS was 74%, while all four patients with high-grade ESS died of disease within 14 months of diagnosis. Using the log-rank test, we found a significant correlation between survival and tumor grade (P = 0.007), DNA ploidy (P = 0.026), SPF (P = 0.048), and FIGO surgical stage (P = 0.026). In conclusion, we found that tumor grade was a strong predictor of clinical outcome in ESS. In addition, a worse prognosis was found for those ESS patients with advanced disease, DNA aneuploidy, and a high SPF. There was no difference between the recurrent and nonrecurrent group of early stage (surgical stage I), low-grade ESS with regard to clinicopathological features, DNA ploidy, SPF, p53, and mdm-2 expression. All patients with high-grade ESS died of disease within 14 months of diagnosis. In contrast, only three of the 11 patients with early stage, low-grade ESS died of disease.

Adenosarcoma of the uterus: a clinicopathologic, DNA flow cytometric, p53 and mdm-2 analysis of 11 cases

Eleven patients with uterine adenosarcoma diagnosed between 1970 and 1995 were evaluated according to DNA ploidy, S-phase fraction, p53 and mdm-2 expression, and traditional clinical and pathological prognostic factors, such as tumor stage, grade and mitotic index. DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors. The patients ranged in age from 41 to 90 years (median, 76 years). Only one patient was premenopausal at the time of diagnosis and five (45%) were nulliparous. One patient had received previous pelvic irradiation for anal squamous carcinoma. Six of the tumors (55%) were pure adenosarcoma and five (45%) were adenosarcoma with sarcomatous overgrowth. Nine patients had a stage I tumor and two had a stage II tumor. Among the six adenosarcomas we found three DNA diploid tumors, two DNA aneuploid tumors, and one DNA multiploid tumor. All adenosarcomas had an S-phase fraction less than 10%, except one that was not assessable. None was p53 positive and only one overexpressed mdm-2. All five adenosarcomas with sarcomatous overgrowth were DNA aneuploid, three (60%) had an S-phase fraction > 10%, two (40%) were p53 positive, and one (20%) overexpressed mdm-2. Five of the eleven patients suffered recurrences, and three (60%) of these developed lung metastases. During the observation period four (36%) patients (2 adenosarcomas and 2 adenosarcoma with sarcomatous overgrowth) died of disease, three patients died of intercurrent disease without recurrence, and the remaining four are alive with no evidence of disease. The overall five-year survival rate for all stages was 69%; for patients with AS it was 80%, while for those with adenosarcoma with sarcomatous overgrowth it was 50%. There were no variables which correlated with survival. In conclusion, we found hat the typical adenosarcoma had a tendency to be of low stage, have a lower mitotic rate and an S-phase fraction <10%. On the other hand, adenosarcomas with sarcomatous overgrowth were of high grade, had a high mitotic rate, and were DNA aneuploid with an S-phase fraction >10%. None of the variables studied correlated with survival. Tumors that were p53-positive or overexpressed mdm-2 did not behave worse than their negative counterpart. All patients who recurred with distant metastases died of disease.

Leiomyosarcoma of the uterus: A clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 49 cases

AIM

The authors analyzed in a retrospective manner the prognostic significance of p53 and mdm-2 expression, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathological prognostic factors in patients with uterine leiomyosarcomas.

MATERIAL

Forty-nine patients were diagnosed with uterine leiomyosarcoma (25 stage I, 4 stage II, 8 stage III, and 12 stage IV). DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors.

RESULTS

Of the 49 patients, 35 (71%) died of disease and 2 died of intercurrent disease. The 5-year survival rate was 33%. FIGO surgical stage, DNA ploidy, SPF, mitotic index, cellular atypia, and tumor grade obtained significance (P < 0.05) in a univariate survival analysis of the leiomyosarcomas. In a multivariate analysis with survival as the end point, stage was found to be the most important factor (P = 0.007); DNA ploidy (P = 0. 045) and SPF (P = 0.041) also had independent prognostic significance. For FIGO stage I tumors, DNA ploidy (P = 0.04) and tumor grade (P = 0.01) were statistically significant in a univariate analysis, while only grade had independent prognostic significance (P = 0.01) in a multivariate analysis. In a univariate analysis including only FIGO stage I and II tumors with disease-free survival as the end point, p53 overexpression (P = 0.0016), DNA ploidy (P = 0.042), and tumor grade (P = 0.008) obtained significance. In a multivariate analysis, only p53 had independent statistical significance (P = 0.01). All p53 immunopositive stage I-II tumors recurred within 28 months from diagnosis.

CONCLUSION

This study found that stage represents the most important prognostic factor for uterine leiomyosarcomas. DNA ploidy and SPF had independent prognostic value. DNA flow cytometry is useful in gaining additional prognostic information. In stage I patients, tumor grade gives significant information regarding clinical outcome. In addition, p53 overexpression may predict a higher risk of recurrence in early stage leiomyosarcomas.

Malignant mixed Müllerian tumors of the uterus: a clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 44 cases

AIM

The authors retrospectively analyzed the prognostic significance of p53, mdm-2, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathologic factors in patients with malignant mixed Müllerian tumors (MMMT) of the uterus.

METHODS

Between 1970 and 1995, 44 uterine tumors were diagnosed as MMMT (21 stage I, 2 stage II, 10 stage III, and 11 stage IV). Thirty-two were homologous type and 12 were heterologous type. DNA flow cytometry and immunohistochemical analysis for p53 and mdm-2 overexpression were performed on paraffin-embedded archival tissue.

RESULTS

68% of the tumors were nondiploid and 61% had an SPF greater than 10%. Sixty-one percent overexpressed p53 and 25% were mdm-2-positive. Furthermore, 91% of the tumors had a mitotic count greater than 10/10 hpf and 95% had high-grade cytologic atypia. Twenty-seven (61%) patients died of tumor and 6 (14%) died of intercurrent disease. Eleven (25%) patients are alive with no evidence of disease. The median follow-up for patients still alive was 59 months (range, 28-178 months). The overall 5-year survival rate was 38%. In a univariate analysis that included stage, histologic type, DNA ploidy, SPF, p53, mdm-2, mitotic index, and age, and with survival as the end point, only stage reached statistically prognostic significance.

CONCLUSION

The majority of the tumors had obvious signs of aggressiveness such as high grade, high mitotic count, nondiploid pattern, high SPF, and overexpression of p53. This study found that stage is the most important prognostic factor for survival in MMMTs of the uterus.

Paclitaxel (Taxol) monotherapy in the treatment of progressive and recurrent ovarian carcinoma after platinum-based chemotherapy

This retrospective study evaluates paclitaxel (Taxol) monotherapy in the treatment of advanced ovarian cancer, previously treated with cisplatin. Forty-six patients with FIGO stage IC to IV were given Taxol in doses of 175 mg/m2 and 135 mg/m2 as a 3-h continuous infusion. All patients were given premedication (prednisone, clemastin, cimetidine) to prevent hypersensitivity reactions. One allergic reaction was observed. Thirty-nine patients showed progress of their disease during treatment and seven showed a response (overall response rate 15.2%; 95% c.i. 4.8-25.6%). There were five total (10.9%) and two partial responses. Among 20 patients who had progressed during or within 6 months of prior cisplatin-based therapy two were responders and two showed partial response (10%). Among 26 patients who had responded to cisplatin but suffered recurrence more than 6 months after cisplatin treatment, there were five total responders (19.2%). We conclude that Taxol treatment does not alter the fact that advanced ovarian carcinoma still carries a grave prognosis. Taxol monotherapy treatment of patients not responding to first line platinum treatment or having relapse within six months of completed therapy, seems to have a limited effect. For those patients responding to the first line platinum treatment that lasts for at least six months the effect of Taxol treatment is more encouraging.

Death rate and recurrence pattern among 841 clinical stage I endometrial cancer patients with special reference to uterine papillary serous carcinoma

Eight hundred thirty-nine clinical stage I endometrial carcinoma patients diagnosed between 1979 and 1988 were treated at the University Hospital in Linköping. Forty-two (5%) had uterine papillary serous carcinoma of which 52% died of their disease. The recurrence rate, defined as new evidence of disease 6 months or more after termination of the initial treatment, was 31% among the UPSC patients compared to 6% in the non-UPSC group. The site of recurrence also differed significantly between the two groups, with the abdomen as the most common site among UPSC patients (46%) and the vagina (34%) among the ordinary adenocarcinoma patients. All UPSC patients with recurrence died of their malignancy compared to 61% of the ordinary adenocarcinoma patients. Ninety percent of isolated vaginal recurrences in ordinary adenocarcinoma patients (17) were diagnosed at a scheduled outpatient checkup. Of these, 13 are alive with no known disease after treatment.

Successful hemisterilization in a patient with uterus didelphus

Women with uterine malformations frequently present with reproductive impairment. This case addresses the opposite problem, a woman with uterus didelphus who conceived with ease. Following three consecutive cesarean sections in the left uterine horn, she was offered sterilization for medical reasons, but refused on religious grounds. As a compromise, she accepted unilateral tubal closure in order to force future pregnancies to the right uterine horn. She has now had three pregnancies with two cesarean sections on that side.

Primary hepatic pregnancy

Abdominal pregnancies are a small fraction of ectopic pregnancies. They usually implant on the peritoneal surface after partial disruption of the initial implantation site in the tubes. The pelvic cavity is the preferential site, but they have been reported from all over the peritoneal cavity. In the present case the pregnancy was situated on the surface of the right liver lobe. Abdominal pregnancies usually present with acute hemoperitoneum and the pre-operative diagnosis is extremely difficult. The possible role of IUDs as an etiological factor is briefly discussed.