Effect of lymph node retrieval rates on the utilization of adjuvant chemotherapy in stage II colon cancer

BACKGROUND

Failing to meet the benchmark of 12 lymph nodes in resection specimens is an indication for adjuvant chemotherapy in stage II colon cancer.

METHODS

Among consecutive eligible patients with pathologic stage II colon cancer treated at eight NCI-designated comprehensive cancer centers between September 1, 2005 and February 19, 2008, we analyzed receipt of adjuvant chemotherapy, with less than 12 versus 12+ lymph nodes removed and examined the primary explanatory variable of interest.

RESULTS

Among 258 patients, 46% received adjuvant chemotherapy. An oxaliplatin-containing regimen was used 67% of the time. Younger age (<50 years, P < 0.001), presence of lymphovascular invasion (P = 0.007), and higher T stage (P = 0.007) were independently associated with adjuvant chemotherapy use. There was significant inter-institutional variability in practice with the proportion receiving treatment ranging from 17% to 64% (P < 0.05). Notably, presence of less than 12 lymph nodes in the surgical specimen was a strong predictor of treatment (P = 0.008).

CONCLUSIONS

Adjuvant chemotherapy use after resection of stage II colon cancer is common, but by no means standard practice at National Comprehensive Cancer Network (NCCN) institutions. More attention to achieving the recommended benchmark for lymph node dissection has the potential to decrease exposure to the toxicity of adjuvant treatment.

Radiochemical study on the mechanism of target fragmentation of Cu, Nb, Pr and Au targets induced by 12C and 40Ar projectiles

A thick-target thick-catcher experiment was performed to measure the formation cross sections and recoil momenta of products from target fragmentation of Cu, Nb, Pr, and Au by using gamma-ray spectrometry. Bombardments of C ions (180, 290, and 400 MeV/u) and Ar ions (290 and 650 MeV/u) were performed at the HIMAC facility in Japan. The results were discussed in comparison with systematics of fragmentation and used to deduce the prefragments in fragmentation process of the measured systems.

Photofission of209Bi at intermediate energies

The reaction yields of 63 radionuclides with the mass numberA= 56 − 135 produced in the photofission of209Bi by bremsstrahlung of end-point energies (E0) from 450 to 1100 MeV have been measured using a catcher foil technique with the aid of intensive chemical separation. The charge distribution was well reproduced by a Gaussian function with the most probable charge (Zp) expressed by a linear function ofA,i.e.,Zp=RA+S, and with theA-independent full width at half maximum (FWHMCD). The charge distribution parametersR,Sand FWHMCDwere independent ofE0above 600 MeV, reflecting the resonance nature in photonuclear reactions at intermediate energies. The weighted mean values atE0≥ 600 MeV wereR= 0.421 ± 0.001,S= 0.6 ± 0.1 and FWHMCD= 2.1 ± 0.1 charge unit (c.u.). The numbers of pre- and post-fission neutrons were deduced to be νpre= 12 ± 1 and νpost= 1.4 ± 0.3, respectively, assuming the Unchanged Charge Distribution (UCD). Based on the charge distribution parameters, the symmetric mass yield distributions with the most probable massApof 96 ± 1 mass unit (m.u.) and the width FWHMMDof 33 ± 1 m.u. were also obtained. The characteristics of the charge and mass yield distributions are discussed by referring to those for197Au based on the results of calculations using the Photon-induced Intranuclear Cascade Analysis code combined with the Generalized Evaporation Model (PICA3/GEM).

Target-dependence of light fragment production in photonuclear reactions at intermediate energies

Yields of7Be,10Be,22Na,24Na and28Mg produced fromnatB,natC,natO,23Na,27Al,natSi,natS,natCl,natK,natCa,natV,55Mn,natFe,59Co,natNi,natCu,89Y,natAg,natIn,141Pr,159Tb,165Ho and197Au in irradiations with bremsstrahlung having maximum end-point energies up to 1200 MeV were measured by γ-ray spectrometry (7Be,22Na,24Na and28Mg) and accelerator mass spectrometry (10Be). The yields of heavier fragments,39Cl,43, 44m, 44g, 46, 47, 48Sc,59Fe, and56, 57, 58, 60Co, were also measured by γ-ray spectrometry in order to survey the relative contribution of fragmentation to spallation and/or fission in the mass yield curves. A distinct difference of the target mass-dependence of these yields has made it possible to disentangle the contributions of photospallation and photofragmentation processes. It was found that the neutron-to-proton ratios of targets strongly affect the formation of the nuclei by fragmentation as revealed in the yields of the isotopic pairs as well as of the single isotopes. The photon results were compared with those of proton-induced reactions, and no clear effect due to the difference of the initial interactions of photons and protons with nuclei was found in the fragment yields.

Nephritogenic Glycoprotein X

When triglycosyl glycopeptide ( nephritogenoside ) was contaminated with glucosyl, galactosyl, mannosyl, and heteropolysaccharide glycopeptide, a mixed lesion of proliferative glomerulonephritis ( PGN ) with immunofluorescent mesangial pattern and membranous glomerulonephritis (MG) with immunofluorescent granular pattern resulted. It was concluded that PGN was caused by the presence of nephritogenoside and MG by the presence of the heteropolysaccharide glycopeptide in the crude nephritogenic glycopeptide mixtures derived from various solubilization steps used to treat the kidney extracts. Trichloroacetic acid treatment of crude nephritogenic glycopeptide mixtures precipitated the heteropolysaccharide glycopeptide of the MG-inducing factor, thus permitting the separation of nephritogenoside from the heteropolysaccharide glycopeptide by a rather simple technique. Both the heteropolysaccharide glycopeptide and Heymann's antigen (so-called tubular antigen) have a common antigenic substance, but we cannot conclude, at the present state, that both substances are chemically the same. The degree of contamination of pure nephritogenoside by this substance that is antigenically the same as Heymann's antigen (in pure nephritogenoside ) can be chemically and accurately determined, based on the evidence that pure nephritogenoside is a glycopeptide having only three glucose residues as the sugar moiety, that is, by estimating the amount of contaminated monosaccharide components such as galactose, mannose, and N-acetylglucosamine.

Nickel-63 production in copper samples exposed to the Hiroshima atomic bomb: estimation based on an excitation function obtained by neutron irradiation experiments

The upper and lower limits of the excitation function of the (63)Cu(n,p)(63)Ni reaction were experimentally determined, and the number of (63)Ni nuclei produced in copper samples exposed to atomic bomb neutrons in Hiroshima was estimated by using the experimental excitation functions and the neutron fluences given in the DS02 dosimetry system. The estimated number of (63)Ni nuclei was compared with that measured and with that calculated using the DS02 dosimetry system and the corresponding ENDF/B-VI cross section. In comparison with DS02, there is about a 60% maximum difference in (63)Ni production at the hypocenter when the experimental upper cross section values are used. The difference becomes smaller at greater distances from the hypocenter and decreases, for example, to less than 30 and 5% when using the upper and lower experimental cross sections at 1,000 m, respectively.

X chromosome inactivation in nuclear transfer ES cells

Nuclear transfer ES (ntES) cells are established from cloned blastocysts generated by somatic cell nuclear transfer and are expected to be an important resource for regenerative medicine. However, cloned mammals, generated by similar methods, show various abnormalities, which suggest disordered gene regulation. Random X chromosome inactivation (XCI) has been observed to take place in cloned female mouse embryos, but XCI does not necessarily occur according to Xce strength, a genetic element that determines the likelihood of each X chromosome to be inactivated. This observation suggests incomplete reprogramming of epigenetic marks related to XCI. Here, we investigated XCI in ntES cell lines, which were established using differentiated embryoid bodies that originated from a female mouse ES cell line. We examined Xist RNA localization, histone modifications in the Xist locus, and XCI choice. We did not find substantial differences between the ntES lines and their parental ES line. This suggests that the Xist locus and the epigenetic marks involved in XCI are reprogrammed by nuclear transfer and subsequent ntES cell establishment. In contrast to skewed XCI in cloned mice, our observations indicate that normal XCI choice takes place in ntES cells, which supports the goal of safe therapeutic cloning for clinical use.

Excitation function for 63Cu(n,p)63Ni reaction in neutron energy range up to 15 MeV

The excitation function for the (63)Cu(n,p)(63)Ni reaction has been measured by activation method using the 4.5 MV Dynamitron accelerator of the Fast Neutron Laboratory of Tohoku University. Copper plates and hollow spherical copper shells were irradiated by neutrons of various energy up to 14.9 MeV produced by the T(p,n), D(d,n), and T(d,n) reactions. The (63)Ni produced in the irradiated copper target was chemically separated. The beta-rays emitted from the extracted (63)Ni were measured by a liquid scintillation method. The cross sections obtained were compared with the evaluated data files of JENDL-3.3, ENDF/B-VI and FENDL/A-2.0. Consequently, it is found that FENDL/A-2.0 is consistent with our experimental data in the energy range studied in this work. The effect of proton shell appeared in the excitation function obtained is also discussed.

Insulin-like growth factor I regulates apoptosis in condylar cartilage

Endogenous insulin-like growth factor-I (IGF-I) is known to affect the growth and development of condylar cartilage. However, the critical effect of IGF-I on cell survival is still unknown. We hypothesized that endogenous IGF-I could regulate the survival of cells of the mandibular condylar cartilage. Mandibular condyles dissected from 12-day-old rats were cultured for 1, 3, and 5 days in medium containing antisense oligodeoxynucleotide (AS-ODN) for IGF-I. Real-time RT-PCR analysis showed that the levels of IGF-I and IGF binding protein (IGFBP)3 mRNAs in the AS-ODN group were significantly decreased. After 3 days' culture, the number of necrotic cells was observed in the undifferentiated mesenchymal cell layer. These cells were TUNEL-positive and confirmed to be apoptotic by electron microscopic observation. Immunoblotting revealed that expression of cleaved caspase3 was increased with AS-ODN. These results may suggest that the cells in the undifferentiated mesenchymal cell layer of the mandibular condyle require IGF-I for survival.

Gene expression of secretory carbonic anhydrase isozymes in striated ducts of canine salivary glands using laser microdissection system

To clarify whether striated duct cells in canine salivary glands synthesize secretory carbonic anhydrase (CA-VI), as is the case with serous acinar cells, the present study utilized laser microdissection to harvest striated duct cells from canine parotid and submandibular glands, and total RNA extracted from these cells was then amplified by reverse transcription-polymerase chain reaction to assess CA-VI gene expression. The results confirmed the local expression of CA-VI mRNA in striated duct cells. This clarified that, in canine salivary glands, CA-VI is synthesized in not only serous acinar cells, but also striated duct cells.

Meeting the 12 lymph nodes (LN) benchmark in colorectal cancer surgery: A comparison of NCCN and SEER data

4015

Background: The American College of Pathology has suggested that 12 or more LN be examined from colorectal cancer surgical specimen. Both ASCO and NCCN have considered adopting the 12 LN threshold as a quality metric. The purpose of this study was to determine whether the 12 LN benchmark is achieved at NCCN specialty centers. Methods: Patients with newly diagnosed stage I-III colon or rectal cancer, who had primary surgery at NCCN centers in 2005–6 were selected (n=345). Similarly, data from 14,019 stage I-III colorectal patients diagnosed in 2002 in a SEER region were obtained to determine the extent to which this goal was met in a population-based sample. Patient characteristics of age, gender, location, stage and number of positive nodes were compared for NCCN and SEER data in regards to number of nodes evaluated. Univariate logistic regression models were developed to identify factors associated with the 12 LN target at the NCCN. Factors evaluated were number of positive nodes, age, gender, comorbidity score, ECOG performance status, insurance, location, stage, surgery technique, and NCCN center. Results: As detailed in the Table , 89% of the 2005–6 NCCN sample and 45% of the SEER sample had at least 12 LN evaluated. For patients treated at NCCN centers, stage I compared to stage III (OR=0.20; 95% CI=0.08 to 0.48, p<0.0001) and rectal cancer (OR=0.44; 95% CI=0.22 to 0.88, p=0.02) were each less likely to achieve the 12 LN target. Conclusions: For patients operated on at NCCN centers, at least 12 LN are almost always removed and examined as part of an oncologic resection. In population based samples, this target is achieved in less than half of cases. With longer follow-up we will be able to link this potential quality metric directly to outcomes and thereby better inform whether increasing the number of nodes evaluated is an important priority for cancer control. Table 1 . Characteristics of CRC patients who did and did not have 12 or more LN evaluated at primary resection.

[Table: see text]

No significant financial relationships to disclose.

Incidence of minimally invasive colorectal cancer (CRC) surgery in patients treated at NCCN institutions

6575

Background: In May 2004 the Clinical Outcomes of Surgical Therapy Study Group published the results of the North American randomized trial demonstrating that oncologic outcome is similar for laparoscopic assisted and open surgery for CRC. This and other studies have shown quicker recovery with laparoscopic CRC surgery including earlier resolution of postoperative ileus, less discomfort, and earlier discharge from the hospital. The extent to which surgeons have adopted the minimally invasive surgical (MIS) approach in CRC is unknown. Methods: Using the NCCN Colon/Rectal Cancer Outcomes Project Database, 715 patients were identified who underwent CRC resection in 2005–6. The distribution of lesions included right colon (39%), left colon (31%), and rectum (30%). The incidence of MIS for CRC and clinicopathologic features associated with this approach were analyzed by logistic regression; results are reported as odd ratio (OR) with 95% confidence intervals (CI), and significance defined at p<0.05 level. Results: A total of 167 (23%) patients underwent MIS colorectal surgery (laparoscopy in 98% and robotic in 2%). Conversion to open surgery was noted in 33 cases (20%). Surgery was performed in outside institutions in 21% of cases prior to patients presenting to NCCN institutions for further treatment. The MIS approach was more common in colon than rectal cancer (30% vs.12%, OR 2.96, CI 1.94–4.51, p<0.0001). Within the colon cancer cohort, right sided lesions were more likely to be approached with MIS techniques rather than left sided lesions (32% vs. 25%; OR 1.42, CI 1.96–2.21, p<0.0001). Stage I tumors were also more likely to be managed with the less invasive approach: Stage I-41%; II-20%; III-21%; IV-19% (Stage I vs. IV, OR=3.00, CI 1.74–5.16 p<0.0001). No differences in surgical approach were noted based on age, gender, race, Charlson comorbidity score, insurance type, or location of surgery (NCCN vs outside facility). Conclusion: The majority of CRC surgery for patients presenting to NCCN institutions is performed by open techniques. Right sided and early stage CRCs were more likely treated with MIS, possibly related to the less demanding nature of the procedure. The adoption of MIS is expected to rise as surgeons become trained in MIS techniques for CRC.

No significant financial relationships to disclose.

Radical surgery is not necessary following neoadjuvant chemotherapy in stage III-IV resectable, non-laryngeal head and neck cancer (NLHNC)

16501

Background: Traditionally, following neoadjuvant chemotherapy (NC), head and neck surgeons have insisted in performing radical surgery regardless of the response to NC. This prospective study evaluates the results of conservative surgery following NC in resectable stage III-IV non-laryngeal head and neck cancer (NLHNC). Methods: Between 1993 and 2003, 70 patients with NLHNC were treated with one of the following NC: Cisplatin and 5FU (17.1%); Cisplatin, 5FU, Leucovorin, and Taxotere (58.6%); Cisplatin, 5FU, and Taxol (24.3%). After three courses of NC, patients were reevaluated to determine the need for local therapy. Local excision or biopsy was performed for patients with near-complete pathological response (n-CPR) or patients with a complete pathological response (CPR). Radical surgery was reserved for patients with partial response (PPR). All patients received radiation to the primary and neck. Results: The median follow up was 35 months, median disease-free survival was 33.4 months and 3-year overall survival was 71.4% for the entire group. Thirty-five patients (50.0%) had a complete pathological response (CPR), 11 (15.7%) had a complete clinical response (CCR) and no pathological staging, 5 patients (7.1%) had a n-CPR, and 19 patients (27.1%) had a partial pathological response (PPR). Primary surgery is shown in the following table : At the time of the last follow up, 1/35 (2.9%) patients with CPR had a local recurrence (LR) at the primary and 5/11 (45.5%) patients with CCR and no pathological staging had a LR; in 3/6 (50%) patients with LR the primary was controlled with salvage surgery. Seven of eleven (63.6%) patients with PPR had a LR, only one achieved local control with salvage surgery. Conclusions: Complete pathological response at the primary site is a good predictor of long term local control in NLHNC. Radical surgery, is not necessary in non-laryngeal head and neck cancers following a complete pathological response at the primary site.

[Table: see text]

No significant financial relationships to disclose.

Phase II trial of carboplatin and infusional cyclosporine with alpha-interferon in recurrent ovarian cancer: a California Cancer Consortium Trial

The purpose of this study was to estimate the response rate of 26-h continuous infusion cyclosporine A (CSA) combined with carboplatin (CBDCA) and subcutaneous alpha-interferon (IFN), in recurrent ovarian cancer (OC), and to measure their effects on CBDCA pharmacokinetics. OC patients relapsing following platinum-based chemotherapy received CBDCA area under the curve (AUC 3) with CSA and IFN, every 3 weeks. The pharmacokinetics of CSA and CBDCA were determined in a subset of patients. Thirty patients received 84 courses of therapy. Three partial responses were observed. Nine patients were stable for >4 months. Toxicity was similar to that observed in our previously reported phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean end of infusion CSA level (high-performance liquid chromatographic assay [HPLC]) was 1109 +/- 291 microg/mL (mean +/- SD). CBDCA pharmacokinetics revealed a measured AUC of 3.61 versus a targeted AUC of 3, suggesting a possible effect of IFN on CBDCA levels versus errors in the estimation of CBDCA clearance using measured creatinine clearance. Steady-state levels of >1 microg/mL CSA (HPLC assay) are achievable in vivo. Insufficient clinical resistance reversal was observed in this study to warrant further investigation of this combination.

Laser burn wound healing in naso-labial region of fetal and neonatal mice

OBJECTIVE

To investigate the characteristics of wound healing in the mouse naso-labial region in both the fetal and neonatal stages, histological and immunohistochemical analyses were performed using a newly established laser burn wound healing system.

MATERIALS AND METHODS

Fetal mice at embryonic day 14 (E 14) were wounded as a model of fetal wound healing. To compare it, neonatal mice at day 5 after birth (d 5) were adopted as a model of neonatal wound healing. The healing process was examined by van Gieson staining and immunohistochemistry for fibronectin and tenascin.

RESULTS

Relatively large damage remained after wound healing even in fetal mice. In both types of wound healing, rapid regeneration of muscle tissues were observed. Fibronectin and tenascin immunostaining was detected not only in wound healing region, but also in the endomysium of regenerating muscle tissues. Especially, tenascin showed a restricted expression pattern.

CONCLUSIONS

Rapid regeneration of muscle tissues in the naso-labial region in both the fetal and neonatal mice seemed to leave relatively large damage even in the fetal wound healing. Contracted force exerted by muscle tissues may be a reason for this phenomenon. Fibronectin and tenascin were closely related to the wound healing process including muscle regeneration in this region.

The Time Course of Lymphatic Routes Emanating from the Peritoneal Cavity in Rats

The lymph drainage routes from the abdominal cavity in rats were observed at 3 min, 1, 2 and 4 h after India ink was administered intraperitoneally. Four systems of lymph drainage routes from the peritoneal cavity were observed. Three minutes after injection, the drainage route travelled via the intrathoracic lymph vessels located along the internal thoracic artery and returned to the anterior mediastinal lymph nodes. One hour after injection, the drainage route travelled via the lymph vessel located along the left phrenic nerve in addition to the drainage route observed at 3 min. Two and four hours after injection, in addition to the above-mentioned routes, the drainage that had travelled via the thoracic duct continued along the right side of the aorta and was also observed in the lateral lymph vessel located on the vertebra. These findings suggest that lymph or cells absorbed into the peritoneal cavity at first travel towards the anterior mediastinal lymph nodes in the thorax via the ventral lymphatic channels, and then gradually course through the dorsal lymphatic channels. These routes may serve as a route for transporting cancer cells and other cells from the peritoneal cavity.

Immunohistolocalization and Gene Expression of the Secretory Carbonic Anhydrase Isozymes (CA-VI) in Canine Oral Mucosa, Salivary Glands and Oesophagus

The immunohistolocalization of secretory carbonic anhydrase isoenzymes (CA-VI) in canine salivary glands, parotid, submandibular, sublingual and zygomatic glands, oral and oesophageal mucosa was studied using a specific antiserum against a canine CA-VI. In addition, the gene expression of CA-VI from the same tissue was studied using a real-time reverse-transcriptase polymerase chain reaction. In all salivary glands and oesophageal gland, immunostaining intensely localized CA-VI antiserum throughout the cytoplasm of serous acinar cells, including serous demilune and ductal epithelial cells. In contrast, no immunoreaction localized CA-VI in the mucous acinar cells of the gland. CA-VI gene transcripts were also detected in the same areas. The physiological significance of secretory CA-VI in the oral and oesophageal cavity is thought to play a highly specialized role in the maintenance of bicarbonate level in saliva and to protect mucosa from acid injury. It is shown that the major sites of the CA-VI secretion in dogs were in serous (demilune) secretory cells in all four major salivary glands and oesophageal glands in particular.

Development of Reformative Surgery Method Using Partial Freezing for the Liver

To minimize surgical stresses including blood loss and operation time to the patients during hepatic resection, we studied the feasibility of a combination of a partial liver freezing technique and shape-memory alloy, which also enables a free-designed resection curve. In this surgical procedure, the region surrounding a tumor in the liver is frozen to excise and prevent hemorrhage. The liver was frozen by a Peltier module. The effects of cooling rate and freezing temperature on the excision force that arise between a scalpel and the liver are carried out experimentally as a basic research for partial freezing surgical procedures. A porcine liver was used as a liver sample. The physical properties were estimated by using the finite element method based on the heat transfer characteristics of the liver. Isolation of the liver was conducted using a scalpel attached to the end-effector of a 3 degrees of freedom robot. In the experiments, the minimum excision force was obtained at a temperature between 272K and 275K; therefore, it is preferable that the liver be excised within this temperature range. Lowering of the cooling rate decreases the excision force even if the temperature of the liver remains unchanged. The lower the temperature of the liver is, the larger the increment rate of excision force is with regard to the cooling rate.

Target preparation by the precipitation method for nuclear reactions

A technique for preparing nuclear reaction targets of various thicknesses was developed by using common filtration technique of hydroxide precipitates with a porous Al(2)O(3) membrane filter. Uniformity was found to be within a few % in each thickness. Durability for beam irradiation was also confirmed. The preparation procedure is convenient and the method is appropriate for several target materials, including not only precious materials but also radioactive materials with low contamination.

Phase I trial of bortezomib in combination with topotecan in advanced solid tumor malignancies

12004

Background: Bortezomib (B) and topotecan (T) have been shown in pre-clinical testing to be synergistic. Based on this data we have performed a phase I study to determine the maximally tolerated dose and toxicities (tox) of B and T delivered sequentially. Methods: 24 pts (KPS<ECOG 3) with advanced malignancies were treated with T (2.0, 2.5, 3.0 or 3.5 mg/m2 in sequential cohorts) IV on days 1 and 8 of each three week cycle. B 1.3 mg/m2 iv was administered six hours following T on days 1 and 8, and alone on days 4 and 12. Pts were treated in cohorts of 3, the MTD dose was expanded to include 10 additional pts for PK analysis. There was no limit on prior therapies. DLT was defined as any gr 3 or 4 non-hematologic toxicity not reversible in 48h or any gr 3 thrombocytopenia lasting >7 days or associated with bleeding or any gr 4. Results: Tumor types included: breast (4), ovary (5), lung (3), others (12). 24 pts were entered (11M 13F). The median age was 55 (range: 34–83). DLT was thrombocytopenia, observed in two pts at 3.5 mg/m2 and one pt at 3.0 mg/m2 (MTD). Other grade 3 or 4 tox included fatigue, lymphopenia, hypomagnesemia, and hypertriglyceridemia. Of the 24 enrolled pts, stable disease was observed in 4 (4 or 5 cycles), 9 progressed, 5 were inevaluable and 6 are too early. PK analysis is pending. Conclusions: T and B delivered sequentially are well tolerated on a weekly schedule. DLT is thrombocytopenia. PK will be presented.(Supported by NCI Grant CA33572).

[Table: see text]

A randomized phase II non-comparative study of Ispinesib given weekly or every three weeks in metastatic colorectal cancer. A California Cancer Consortium Study (CCC-P)

3595

Background: Ispinesib(SB-715992) is a polycyclic, nitrogen-containing heterocycle that inhibits the mitotic kinesin spindle protein (KSP). KSP is essential for mitotic spindle assembly and function during mitosis, and is a rational target of anti-cancer therapy. This phase II study used two different dosing schedules; the primary objective was to determine the response rate (RR) and the secondary objectives were to determine time to tumor progression (TTP), progression free survival (PFS), overall survival (OS) and toxicity. Methods: Patients (pts) were randomized to receive (Arm A) ispinesib 7 mg/m2 every week for 3 weeks, every 28 days or (Arm B) 18 mg/m2 every 21 days. Response was assessed every 6 weeks. Chemotherapy was administered until disease progression or intolerance. Results: A total of 64 pts were accrued. The median number of cycles was 2 for both arms. Five pts had stable disease and 48 had progressive disease. PFS was 49 days in Arm A (44 to 51) and 37 days in Arm B (35 to 42 days). The most common grade 3/4 toxicities in arms A and B respectively included neutropenia (3 and 20), nausea and vomiting (3 and 1), neurologic (1 and 2). Of these, only 1 pt had febrile neutropenia and 1 pt had peripheral sensory neuropathy. The toxicity data is not available on 2 patients. Eleven pts are not evaluable for response yet. Conclusions: Ispinesib did not demonstrate significant activity in heavily pretreated patients with advanced/metastatic colorectal cancer at the dose and schedule employed in this trial. Correlative studies are in progress. Supported by NO1 CM17101

[Table: see text]

No significant financial relationships to disclose.

Phase II study of hydroxyurea and gemcitabine in recurrent or persistent squamous cell cancer of the head and neck

15524

Background: Preclinical studies demonstrate increased activity when hydroxyurea (HU) is given prior to gemcitabine (G). Clinical feasibility was demonstrated in a phase I trial (Yen, et. al. Cancer Chemother Pharmacol. 2002 ). We performed a phase II trial treating patients (pts) with squamous cell head and neck cancers (SCCHN). Methods: Pts had metastatic or incurable locally recurrent SCCHN. Prior chemotherapy was allowed, but not required. Serum creatinine ≤2.0 mg/dl, bilirubin <3.0 gm/dl, AST/ALT <5× ULN and KPS ≥60% were required. HU 500 mg orally every 6 hours for 4 doses was given on day 1 of a 21-day cycle. On day 2, 6 hours after HU, G 750 mg/m2 was given over 30 minutes. This sequence was repeated on day 8 and 9. After 8 pts, G was given at 500 mg/m2. G-CSF was given on day 10 and until the WBC count was >10k/μl. The primary endpoint was response rate (RR), with an early stopping rule for <3 objective responders among the first 18 pts. Results: 22 pts (17 M) were accrued, 16 with prior chemotherapy and 19 with prior radiation. The first 8 pts received G 750 mg/m2. Two pts died of neutropenic fever (NF) during course 1. Subsequently 14 pts received G 500 mg/m2. 18 pts were evaluable for response, with 1 still in follow-up. Partial response was seen in 1 pt, stable disease in 9, and progressive disease in 8. The overall median survival of the 22 pts was 6 months and the median progression free survival (PFS) was 2 months. The primary toxicity was hematologic. Grade 4 neutropenia was seen in 7/22 pts during the 1st cycle (5 at G 750 mg/m2) with 5 cases of NF. Grade 4 thrombocytopenia occurred in 1 pt at G 750 mg/m2. Conclusions: The RR and PFS of treated pts treated were not promising and further accrual is not planned. Analysis of biopsy materials is planned to see if responsive pts can be selected. (Supported by NCI Grant CA33572).

No significant financial relationships to disclose.

Temporary restorative resins using non-phthalate ester plasticizers

OBJECTIVE

This study examined temporary restorative resins that use non-phthalate ester plasticizers.

METHODS

Three non-phthalate plasticizers were tested: tri-ethyl citrate (TEC), tri-butyl citrate (TBC), and di-butyl sebacate (DBS). The experimental resins were compared with resins that use a phthalate ester plasticizer (di-butyl phthalate, DBP) and commercial products (Dura Seal, Plast Seal, and Fit Seal). For the experimental resins, the ratio of plasticizer to PMMA/MMA resin was varied from 30 to 60% (wt). The mechanical properties of the experimental resins were evaluated using a modified diametral compressive strength and the resistance to explorer insertion.

RESULTS

The strengths of the experimental resins with plasticizer concentrations ranging from 40 to 50% (TEC, TBC, and DBP) or from 30 to 40% (DBS), by weight, were equivalent to the strengths of commercial temporary restorative resins. A similar tendency was seen for the resistance to explorer insertion.

CONCLUSIONS

The results suggest that new temporary restorative resins can be prepared by choosing the appropriate proportions of resin monomer and non-phthalate ester plasticizer.

Portal flow into the liver through veins at the site of biliary-enteric anastomosis

The aim of this study was to establish the role played by jejunal veins in hepatopetal flow after biliary-enteric anastomosis and to evaluate the helical CT features of hepatopetal flow through the anastomosis. We retrospectively analyzed helical CT images of the liver in 31 patients with biliary-enteric anastomosis who underwent hepatic angiography with (n=13) or without (n=18) CT arterial portography within 2 weeks of the CT examination during the last 4 years. Arterial portography showed hepatopetal flow through small vessels located (communicating veins) between the elevated jejunal veins and the intrahepatic portal branches in two (9%) of 22 patients with a normal portal system. Helical CT showed focal parenchymal enhancement around the anastomosis in these two patients. All nine patients with extrahepatic portal vein occlusion (100%) had hepatopetal flow through the anastomosis, and four of the nine had decreased portal flow. CT revealed small communicating veins in two of these four patients. In five patients with normal portal perfusion despite extrahepatic portal vein occlusion, CT detected dilated communicating veins and elevated jejunal veins. The presence of communicating veins and/or focal parenchymal enhancement around the anastomosis indicates hepatopetal flow through the elevated jejunal veins.

Protease susceptibility of the Caulobacter crescentus flagellar hook–basal body: a possible mechanism of flagellar ejection during cell differentiation

When motile swarmer cells of Caulobacter crescentus differentiate into sessile stalked cells, the flagellum is ejected. To elucidate the molecular mechanism of the flagellar ejection, flagellar hook–basal body (HBB) complexes from C. crescentus were purified and characterized. The purified HBBs were less stable against acidic pH or protease treatment than HBBs of Salmonella typhimurium, supporting the view that flagellar ejection from C. crescentus is initiated by destruction of the fragile basal structures. In addition, protease treatment of the purified flagella resulted in the specific digestion of the MS ring complex, revealing for the first time the intact structure of the whole rod.