Droplet motion in microfluidic networks: Hydrodynamic interactions and pressure-drop measurements

We present experimental, numerical, and theoretical studies of droplet flows in hydrodynamic networks. Using both millifluidic and microfluidic devices, we study the partitioning of monodisperse droplets in an asymmetric loop. In both cases, we show that droplet traffic results from the hydrodynamic feedback due to the presence of droplets in the outlet channels. We develop a recently-introduced phenomenological model [W. Engl, Phys. Rev. Lett. 95, 208304 (2005)] and successfully confront its predictions to our experimental results. This approach offers a simple way to measure the excess hydrodynamic resistance of a channel filled with droplets. We discuss the traffic behavior and the variations in the corresponding hydrodynamic resistance length L_{d} and of the droplet mobility beta , as a function of droplet interdistance and confinement for channels having circular or rectangular cross sections.

[Medical disorders and pregnancy. Gastrointestinal, neurological, cardiovascular and dermatological disorders]

A pregnant woman can present medical pathologies similar to a woman who is not pregnant. However, the clinical features of some pathologies and the diagnostic or therapeutic process might be altered due to changes produced by pregnancy and the presence of the foetus. In some cases this can limit the diagnostic methods or the therapies to be applied. This article sets out the digestive and cardiovascular pathologies, pathologies of the nervous system and dermatoses of greatest relevance due to their frequency or severity, which might be encountered in an emergency consultation. It also offers a practical approach for the initial handling and the prognosis for the mother and the foetus.

[Medical disorders and pregnancy. Respiratory, urologic, infectious and endocrinologic disorders]

Pregnancy is a state that changes the physiology of various organs and systems. The occurrence of concomitant diseases, or their presence prior to pregnancy, requires an understanding of such changes and their influence on the disease, the impact of the disease and the diagnostic and therapeutic measures on pregnant women and on the foetus. The aim of this paper is to provide a concise outline of the course of action recommended in dealing with pregnant women who attend the emergency department presenting symptoms of non-specific morbidity of pregnancy. Some of the most frequent pathologies classified by systems are presented.

Supraspinal modulation of pain by cannabinoids: the role of GABA and glutamate

Recent physiological, pharmacological and anatomical studies provide evidence that one of the main roles of the endocannabinoid system in the brain is the regulation of gamma-aminobutyric acid (GABA) and glutamate release. This article aims to review this evidence in the context of its implications for pain. We first provide a brief overview of supraspinal regulation of nociception, followed by a review of the evidence that the brain's endocannabinoid system modulates nociception. We look in detail at regulation of supraspinal GABAergic and glutamatergic neurons by the endocannabinoid system and by exogenously administered cannabinoids. Finally, we review the evidence that cannabinoid-mediated modulation of pain involves modulation of GABAergic and glutamatergic neurotransmission in key brain regions.

Results of all-intraperitoneal carboplatin and paclitaxel regimen shows good tolerability and efficacy for advanced ovarian cancer

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Background: A phase III trial (GOG 172) demonstrated improved survival for patients (pts) with optimally-debulked ovarian cancer treated with intraperitoneal (IP) cisplatin and paclitaxel, as compared with standard IV dosing. Studies to further enhance efficacy and minimize toxicity of IP platinum/taxane regimens are needed. We present the clinical results of a novel IP regimen in follow-up to the pharmacokinetics (pk) results presented last year. Methods: Carboplatin at an AUC 6 on day 1 and paclitaxel 60 mg/m2 on days 1, 8, 15 was given, IV in cycle 1 and IP in the 5 subsequent 21-day cycles. The initial IV cycle was designed to allow for intra-patient IV vs. IP pk comparison. Pts completing 6 cycles with clinical complete response (CCR) underwent second-look operation (SLO). Results: Accrual is complete with 40 evaluable pts, 8 pts remain on trial. Pts came off study for: port-related complications (7), allergy (2), heme tox (2), vaginal leak (2), and infection (4). Toxicity was mild, with grade 3 or 4 toxicity consisting of neutropenia: 10 (25%), plts: 2 (5%), vomiting: 2 (5%), fatigue: 2 (5%) and anemia: 1 (2.5%). There was no grade 3 or 4 peripheral neuropathy or alopecia. Completion rate was good with 82% of pts completing = 4 cycles, as compared with 52% in GOG 172. All pts completing chemotherapy were judged to be in CCR; there was no progressive disease on trial. Of the pts undergoing SLO, 14 pts were negative, 4 pts were positive, for complete pathological response rate of 78%. Conclusions: Pts were able to complete more cycles of therapy on this regimen as compared with GOG 172. The incidence of gastrointestinal, metabolic, and neurotoxicity is very low. Preliminary SLO rate compares favorably to the 57% seen in GOG 172. Previously reported pk results as well as tolerability and efficacy are encouraging and suggest this regimen should be studied in a larger population. Final toxicity and response data will be available.

No significant financial relationships to disclose.

Safety of maintenance bevacizumab after first-line chemotherapy for advanced ovarian and müllerian cancers

5517

Background: Bevacizumab is a recombinant humanized monoclonal antibody that neutralizes VEGF, but is associated with arterial complications and GI perforations in patients with advanced ovarian cancer. Maintenance antiangiogenic therapy is an attractive strategy for patients after first line therapy. However, no data exist on the safety of maintenance bevacizumab in this setting. Methods: An open label phase II clinical trial of carboplatin, paclitaxel and bevacizumab (CPB) in newly diagnosed patients =ECOG 2, with chemotherapy naïve, stage =IC, epithelial müllerian tumors. Patients receive carboplatin AUC 5 IV, paclitaxel 175 mg/m2 IV, and bevacizumab 15 mg/kg IV for 6–8 cycles D1 Q21. Bevacizumab is omitted in the first cycle, and continued as single agent for one year. Results: 58 patients are evaluable. Median age is 58 (18–77), and 39(67%) were ECOG 1. 43(74%) have ovarian, 8(14%) uterine papillary serous (UPSC) tumors, 4(7%) peritoneal, and 3(5%) fallopian tube cancers. 38(65%) were serous, 8(14%) MMMT, 4(7%) clear cell, and 3(5%) endometrioid cancers (5(9%) mixed/other). 36(62%) were stage III and 11(19%) stage IV. Surgery was optimal in 45(80%) patients. 50 patients have completed chemotherapy, associated with 2 PEs, and 2 GI perforations, all occurring during the induction chemotherapy phase of treatment. 43 patients have received 360 cycles of maintenance therapy with mild toxicity. 6(14%) have come off for PD, 4(9%) for toxicity (inc. 1 nasal perforation), 4 withdrew consent, and 3 patients asymptomatic, continue despite a rising CA125. During maintenance there has been no grade IV toxicity, and 13 grade III toxicities (musculoskeletal pain (5), dyspnea, hyperglycemia, hypertension (1 grade III, 4 grade II), infection, lymphopenia, thrombocytopenia, proteinuria, syncope). Radiographic responses were documented in 21 of 28 (75%: CR 11, PR 10). Median PFS is 11(1–21) months at 13 months median FU. Conclusion: Maintenance bevacizumab is feasible and well tolerated with mild myalgias, and hypertension common but treatable side effects.

No significant financial relationships to disclose.

Stage, grade and morphology of tumours of the colon and rectum recorded in the Oxford Cancer Registry, 1995-2003

Data on stage, grade and morphology of 12,761 colorectal cancers registered between 1995 and 2003 by Oxford Cancer Registry are reviewed. Dukes stage is recorded for 81% of colon cancers and for 69% of rectal cancers. Incomplete registry data and changing recording practices may affect future evaluation of bowel cancer screening.

Three sequential chemotherapy doublets for the treatment of newly diagnosed advanced müllerian malignancies: The modified triple doublet regimen

OBJECTIVE

Previously, we reported the use of three sequential doublets (Triple Doublets) in the treatment of women with newly diagnosed and advanced stage müllerian malignancies. The surgically defined negative second look operation (SLO) rate to Triple Doublets was 38%. Modifications were made to this treatment regimen that were predicted to reduce toxicity and possibly increase efficacy.

METHODS

Open label two-cohort study. Patients with a new diagnosis of Stages II-IV müllerian malignancy were eligible. After cytoreductive surgery, patients were treated with three sequential doublets including 3 cycles of carboplatin and gemcitabine, and 3 cycles of carboplatin and paclitaxel, and 3 cycles of doxorubicin and topotecan. After therapy, all women were clinically staged and evaluated at SLO if clinical staging was negative for residual disease. Primary endpoints were toxicity and negative SLO rate with rates of 60% and 40% defined a priori in optimally cytoreduced (cohort 1) and suboptimally cytoreduced or Stage IV (cohort 2), respectively.

RESULTS

Eighty-five eligible patients were enrolled with a median age of 52 years. Forty-seven and thirty-eight women were in cohorts 1 and 2, respectively. 723 cycles of chemotherapy were delivered with no toxic deaths. Grades 3 and 4 toxicities included neutropenia in 75% of patients and thrombocytopenia in 65% of patients during at least one cycle of therapy. Fever and neutropenia were seen in 3.5% of patients. All Grades 3 and 4 non-hematologic toxicities were seen at a frequency of <10%. Seventy women underwent SLO with a negative SLO rate of 53% with an additional 9% having microscopically positive procedures. Negative SLO rate was 74% in cohort 1 and 36% in cohort 2.

CONCLUSIONS

Treatment with the modified triple doublet regimen is tolerable with an encouraging pathologic CR rate.

A case of septic arthritis due to infection with Gemella morbillorum

Gemella morbillorum is a facultatively anaerobic Gram-positive coccus which forms part of the normal flora of the oro-pharynx and the upper respiratory tract. It rarely causes human infection but has been described previously in cases of empyema and lung abscess, septic shock, endocarditis, meningitis, and osteomyelitis. We describe a case of septic arthritis due to G. morbillorum occurring in an otherwise healthy 42-year old man and review previous reports of infection in the literature.

Pharmacokinetic analysis of an all intraperitoneal carboplatin and paclitaxel regimen in ovarian cancer patients demonstrates favorable systemic bioavailability of both agents

5008

Background: A phase III trial (GOG172) demonstrated improved survival for patients with newly diagnosed and optimally debulked ovarian cancer treated with intraperitoneal (ip) cisplatin and paclitaxel (P), given both as a 24 h iv infusion and ip, as compared with standard iv dosing. Studies to further enhance efficacy and minimize toxicity of ip taxane/platinum regimens are needed. Because adequate systemic drug exposure is thought to be essential for maximum therapeutic benefit of ip chemotherapy, the pharmacokinetics (PK) and bioavailability of ip P and carboplatin (C) were determined in this pt population in a phase II trial to evaluate dosing by the ip route alone. Methods: P 60 mg/m2 once a week and C at an AUC 6 every weeks were infused over 1 h, iv in cycle 1 and ip in the 5 subsequent 21-day cycles. Plasma samples were collected during week 1 of cycles 1, 2 and 6. P was measured by LC/MS and free platinum (fPt) was determined by flameless atomic absorption. Results: PK data is available for 14 pts receiving at least 1 cycle of ip therapy and for 7 pts who received all 5 cycles. When given ip, P achieved a peak conc. in plasma (Cmax) of 0.086 ± 0.034 μM (mean ± SD) at 6.4 ± 2.2 h, 22-times lower than Cmax for iv infusion (1.92 ± 0.80 μM). Thereafter, P plasma levels were comparable for both routes and decayed at similar rates with a half-life of 13.9 ± 4.1 h for iv and 13.7 ± 2.2 h for ip dosing. The systemic bioavailability of ip P was 53 ± 19% for the initial dose and 46 ± 10% in cycle 6. P plasma levels exceeded 0.05 μM, the pharmacologic threshold conc., for >20 h upon ip dosing in 67% (10/15) and 71% (5/7) of pts in cycles 2 and 6, respectively. C was rapidly absorbed into systemic circulation when given ip with a Cmax of 83 ± 11 μM for fPt at 1.6 ± 0.2 h in cycle 2. Consistent with prior reports, systemic availability of fPt exceeded 100% (133 ± 22% in cycle 2; 142 ± 47% in cycle 6). Conclusions: Weekly ip P 60 mg/m2 with ip C (AUC 6) every 3 weeks achieved a potentially effective pattern of systemic exposure to both agents in a majority of pts. The cumulative time that P plasma levels are >0.05 μM per cycle of therapy is likely to be longer than provided by the iv/ip dosing regimen for P (135 mg/m2 24 h iv infusion day 1; 60 mg/m2 ip day 8) used in GOG172.

No significant financial relationships to disclose.

Phase II trial of GM-CSF in women with asymptomatic müllerian cancer

5081

Background: GM-CSF is a recombinant human cytokine, which increases the proliferation of granulocytes and monocytes. Experience with this agent, including adjuvant studies in melanoma, vaccine-based studies using autologous tumor vaccines that secrete human GM-CSF, and studies in prostate cancer using GM-CSF have all suggested that GM-CSF might provide anti-tumor activity in a subset of cancer patients. Methods: Open label phase II study performed in asymptomatic patients with recurrent mullerian malignancy without an indication for immediate systemic chemotherapy. Patients could have measurable or evaluable disease (defined as CA-125 >35 U/ml or 2 successively rising values with the most recent 3x the nadir value.) GM-CSF 250 mcg/m2 was administered subcutaneously on days 1–14 of a 28-day cycle. Monthly follow-up included interim history, physical exam and CA-125, with radiologic evaluation q 3 months. Results: Enrollment to this cohort is complete. Thirty-five women with a median age of 60 were enrolled; data are available on 33:30 women with ovarian and 3 with primary peritoneal cancers. To date 31 women are evaluable for response. Best overall response of patients who have completed the study includes 6 patients with stable disease (18%). Median time to treatment termination (TTT) was 76 days. Four patients remain on study, 2 with SD >6 months. Toxicity was generally mild, including injection site reaction, fatigue, and bone pain, however 2 patients experienced excessive toxicity and withdrew consent. There were 3 bowel obstructions thought related to disease but contribution of drug could not be ruled out. After 14 days of GM-CSF, CA-125 dropped in 23 of 33 women (70%) from their baseline on study value (median change -23%, range −48 to +158%). The magnitude of CA-125 drop during the first two weeks of therapy was significantly and positively correlated with day 15 WBC (p = 0.04.) Conclusions: GM-CSF is well tolerated and frequently associated with a decline in CA-125 that is correlated with leukocytosis. Although median TTT for the entire group is modest, a subset of women have had prolonged stable disease. Strategies to maintain and titrate leukocytosis are now being explored in a separate cohort.

No significant financial relationships to disclose.

[Von Meyenburg disease found during laparoscopic surgery: report of two cases]

The authors report two cases of von Meyenburg complexes disease found during laparoscopic surgical procedures. The first patient (41 years old) had multiple gallbladder stones with recurrent hepatic colics. The second patient (45 years old) had gastroesophageal reflux with recurrent peptic esophagitis. In both cases, multiple millimetric and superficial hepatic lesions were found during the exploration of the abdominal cavity. Then, an hepatic biopsy was done because the macroscopic aspect should suspect secondary metastatic lesions. Histological result made the diagnosis of von Meyenburg complexes disease (biliary microhamartomas). It seems to be important to know this anomaly of the ductal plate development and to do a liver biopsy during laparoscopy to affirm the diagnosis and cancel the diagnosis of multiple hepatic metastasis. In fact, this congenital pathology could be associated with increased risk of cholangiocarcinoma of the liver. The modality of radiological monitoring still remains to be defined.