Engineering dynamics of growth factors and other therapeutic ligands

Peptide growth factors and other receptor-binding cytokine ligands are of interest in contemporary molecular health care approaches in applications such as wound healing, tissue regeneration, and gene therapy. Development of effective technologies based on operation of these regulatory molecules requires an ability to deliver the ligands to target cells in a reliable and well-characterizable manner. Quantitative information concerning the fate of peptide ligands within tissues is necessary for adequate interpretation of experimental observations at the tissue level and for truly rational engineering design of ligand-based therapies. To address this need, we are undertaking efforts to elucidate effects of key molecular and cellular parameters on temporal and spatial distribution of cytokines in cell population and cell/matrix systems. In this article we summarize some of our recent findings on dynamics of growth factor depletion by cellular endocytic trafficking, growth factor transport through cellular matrices, and growth factor production and release by autocrine cell systems. (c) 1996 John Wiley & Sons, Inc.

An unusual case of left main coronary artery aneurysm with right ventricle fistula

A 4-year-old boy presented with repeated respiratory tract infections. Echocardiography showed dilation of the left main coronary artery with flow into the Right Ventricular Outflow Tract (RVOT). Diagnosis of Left Coronary Artery Aneurysm (LMCA) with RVOT fistula was made. A surgical repair of LMCA aneurysm by two-patch technique was performed. The patient had an excellent outcome postoperatively and is asymptomatic on follow-up.

Varietal differences in accumulation of aflatoxin B1 in Indian rice cultivars

Rice (paddy) seeds are known to be colonised by Aspergillus flavus in the field or under storage conditions and contaminated with aflatoxins which have impact on human and animal health. In this study, we investigated the varietal differences in 30 Indian healthy rice cultivars used for human consumption (15 normal and 15 basmati) for accumulation of aflatoxin B1 (AFB1) after inoculation with aflatoxin-producing A. flavus (DRAf 009). Significant varietal differences in AFB1 accumulation were observed in normal and basmati rice cultivars. Comparatively, the accumulation of AFB1 is higher in normal cultivars, ranging from 3-628 µg/kg, than in basmati cultivars, ranging from 0.2-7.2 µg/kg. The highest accumulation of AFB1 in normal cultivars was observed in PR 106 (628 µg/kg) and the lowest in IR 64 (3 µg/kg). In basmati rice cultivars, the highest accumulation of AFB1 was observed in Ranbir basmati (7.2 µg/kg) and the lowest in Vasumati (0.2 µg/kg). All these cultivars were evaluated for their total phenolic content (TPC) in rice bran using the Folin-Ciocalteau method. The results indicated that the TPC of normal and basmati cultivars was in the range of 1.96-2.45 and 2.13-2.65 mg gallic acid equivalent (mg/g of bran), respectively. This study may be used as a basis to develop A. flavus resistant rice cultivars and proper storage structures to produce aflatoxin-free rice. This is the first report on the evaluation of various rice cultivars for accumulation of AFB1 after inoculation with A. flavus.

Fluoroscopically guided percutaneous peritoneal dialysis catheter placement: single center experience and review of the literature

Experiences with minimally invasive techniques for peritoneal dialysis (PD) catheter placement are being increasingly described. Percutaneous placement of catheters using ultrasound and fluoroscopic guidance has reduced the risk of complications and has led to successful long-term catheter function. An interventional radiology catheter placement capability was established at our facility and it serves as the basis for this report. We performed a retrospective analysis of patients in a tertiary care center in Northern California who required PD between July 2005 and October 2008. Patients underwent PD catheter placement in an interventional radiology suite by the radiologist using a percutaneous Seldinger technique that was guided by fluoroscopy. Sixty-four patients between the ages of 25 and 90 were referred for fluoroscopic PD catheter placement by an interventional radiologist. If clinically indicated, PD was initiated within days of catheter placement. Minor complications were noted: four with minor bleeding, three with catheter migration, and one with temporary exit-site leakage. No bowel or bladder perforations were encountered. Fluoroscopically guided PD catheter placement by interventional radiologists can be a safe and cost-effective strategy to initiate acute or chronic PD. This approach could reduce the need for temporary vascular access and expedite the initiation of PD therapy by eliminating the delays in catheter placement often associated with surgical consultation and operating room scheduling.

Molecular characterization and experimental host range of an isolate of Wissadula golden mosaic St. Thomas virus

Partial genome segments of a begomovirus were previously amplified from Wissadula amplissima exhibiting yellow-mosaic and leaf-curl symptoms in the parish of St. Thomas, Jamaica and this isolate assigned to a tentative begomovirus species, Wissadula golden mosaic St. Thomas virus. To clone the complete genome of this isolate of Wissadula golden mosaic St. Thomas virus, abutting primers were designed to PCR amplify its full-length DNA-A and DNA-B components. Sequence analysis of the complete begomovirus genome obtained, confirmed that it belongs to a distinct begomovirus species and this isolate was named Wissadula golden mosaic St. Thomas virus-[Jamaica:Albion:2005] (WGMSTV-[JM:Alb:05]). The genome of WGMSTV-[JM:Alb:05] is organized similar to that of other bipartite Western Hemisphere begomoviruses. Phylogenetic analyses placed the genome components of WGMSTV-[JM:Alb:05] in the Abutilon mosaic virus clade and showed that the DNA-A component is most closely related to four begomovirus species from Cuba, Tobacco leaf curl Cuba virus, Tobacco leaf rugose virus, Tobacco mottle leaf curl virus, and Tomato yellow distortion leaf virus. The putative Rep-binding-site motif in the common region of WGMSTV-[JM:Alb:05] was observed to be identical to that of Chino del tomate virus-Tomato [Mexico:Sinaloa:1983], Sida yellow mosaic Yucatan virus-[Mexico:Yucatan:2005], and Tomato leaf curl Sinaloa virus-[Nicaragua:Santa Lucia], suggesting that WGMSTV-[JM:Alb:05] is capable of forming viable pseudo-recombinants with these begomoviruses, but not with other members of the Abutilon mosaic virus clade. Biolistic inoculation of test plant species with partial dimers of the WGMSTV-[JM:Alb:05] DNA-A and DNA-B components showed that the virus was infectious to Nicotiana benthamiana and W. amplissima and the cultivated species Phaseolus vulgaris (kidney bean) and Lycopersicon esculentum (tomato). Infected W. amplissima plants developed symptoms similar to symptoms observed under field conditions, confirming that this virus is a causal agent of Wissadula yellow mosaic disease in W. amplissima.

A phase I/II trial of gefitinib given concurrently with radiotherapy in patients with nonmetastatic prostate cancer

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Background: We estimated the safety and tolerability of 250 mg gefitinib q.d. given concurrently with three- dimensional conformal radiotherapy (3D-CRT) in patients with non-metastatic prostate cancer (PC). Methods: 42 patients with T2/T3N0M0 PC were treated in a single centre, non-randomized study (study code ZD1839/IL0118). PSA<20 and good performance status (WHO 0–1) were required. Adjuvant or neo-adjuvant hormonal treatments were not allowed. 250 mg gefitinib q.d. was started one week before and lasted for the duration of radiation therapy. 50.4 Gy (1.8 Gy/day) of 3D-CRT was administered to the tumor, prostate and seminal vesicles, followed by a 22 Gy booster (2 Gy/day) for a 72.4 Gy total dose. EGFR expression, presence of EGFRvIII and activated pEGFR were studied. Levels of serum TNF, IL-1 α and IL-6 were also evaluated. Results: Maximum tolerated dose was not reached in phase I (12 patients) and 30 additional patients were treated in phase II. Thirty (71.4%) patients completed trial medication and 12 (28.6%) prematurely discontinued because of adverse events. Dose-limiting toxicities were recorded in 16 (38.1%) patients, the most common of which was grade 3–4 transaminase increase (6 patients). After median follow-up of 38 months nobody had died of PC. The estimated PSA-free survival rate at 4 years (Kaplan-Meier) was 97%, hormone-free survival 91% and overall survival 87%. These figures compared favourably with matched, non-randomized patients treated with radiation only. Data on biochemical analyses will be presented. Conclusions: The combination of gefitinib and radiation is reasonably well tolerated and has promising activity in non-metastatic PC. A randomized study is being discussed for evaluating the efficacy of the approach.

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Use of PET SUV for primary tumor to predict outcome in locally advanced esophageal cancer treated with trimodality therapy

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Background: To assess the value of the primary tumor's SUVmax (PT-SUVmax) from the staging FDG-PET as a predictor of clinical and pathologic outcomes in patients undergoing trimodality therapy for locally advanced esophageal cancer. Methods: A retrospective chart review was conducted on patients with T3/4 and/or node positive esophageal carcinoma treated at the Cleveland Clinic between 7/1/03 and 5/31/06. All patients were managed with an institutional regimen consisting of preoperative radiotherapy [30 Gy @ 1.5 Gy twice daily over two weeks] with concurrent cisplatin and 5-fluorouracil during the first week. Following resection, an identical postoperative course of concurrent chemoradiotherapy (CRT) was delivered. Pretreatment patient and tumor characteristics including PT-SUVmax were analyzed with respect to response and survival. Results: 141 patients completed preoperative CRT: 125 (88.7%) were male, median age was 60 years, 73.8% had adenocarcinoma, 79.4% had N1 disease, 81.6% underwent surgery and 63.8% completed the full regimen. Median follow-up was 17.2 months [range 0.7–75.1]. Median PT-SUVmax was 9.43 [range 0 to 47.7]. Increasing clinical stage was associated with increasing PT-SUVmaxs: for cT2 vs. cT3 and cN0 vs. cN1, PT-SUVmax cutoffs were 8 (p=0.03) and 11 (p=0.02), respectively. Median (MST) and 5-year overall survivals were 20.7 months and 27.4%, respectively. A PT-SUVmax of < vs. > 7 was a significant predictor for T downstaging (p=0.0502) and N downstaging (p=0.0467). A PT-SUVmax cutoff of 7.6 was associated with a significant difference in MST, at 29.1 and 13.0 months for PT-SUVmax< 7.6 and >7.6, respectively (p=0.0158, HR=1.82, 95%CI=1.19–2.94). On multivariate analysis, PT-SUVmax was the only significant factor associated with survival (p=0.0.314, HR=1.71, 95%CI=1.05–2.79). Conclusions: The pretreatment SUVmax of a primary esophageal cancer appears to correlate with clinical stage, pathologic response to therapy and survival. This finding could play a role in the design of clinical trials and in adapting treatment strategies.

No significant financial relationships to disclose.

A Phase II study of the sterilising activities of ofloxacin, gatifloxacin and moxifloxacin in pulmonary tuberculosis

SETTING

Current treatment for pulmonary tuberculosis (TB) might be shortened by the incorporation of fluoroquinolones (FQs).

OBJECTIVES

A Phase II study aimed to assess the sterilising activities of three novel regimens containing FQs before a Phase III trial of a 4-month regimen containing gatifloxacin (GFX).

DESIGN

A total of 217 newly diagnosed smear-positive patients were randomly allocated to one of four regimens: isoniazid (INH), pyrazinamide and rifampicin (RMP) with either ethambutol, GFX, moxifloxacin (MFX) or ofloxacin (OFX) for 2 months. At the end of the study, RMP and INH were given for 4 months. The rates of elimination of Mycobacterium tuberculosis were compared in the regimens using non-linear mixed effects modelling of the serial sputum colony counts (SSCC) during the first 8 weeks.

RESULTS

After adjustment for covariates, MFX substitution appeared superior during the early phase of a bi-exponential fall in colony counts, but significant and similar acceleration of bacillary elimination during the late phase occurred with both GFX and MFX (P = 0.002). Substitution of OFX had no effect. These findings were supported by estimates of time to conversion, using Cox regression, but there were no significant differences in proportions culture-negative at 8 weeks.

CONCLUSIONS

GFX and MFX improve the sterilising activity of regimens and might shorten treatment; their progression into Phase III trials therefore seems warranted.