Phase I-II trial of ONYX-015 in combination with MAP chemotherapy in patients with advanced sarcomas

ONYX-015 is a provisionally replication competent adenovirus with oncolytic activity in cells with malfunctioning p53. Sarcomas represent a rational target for this approach given the high frequency of p53 mutations (40-75%) and MDM-2 amplification (10-30%). We, therefore, undertook a phase I/II study of ONYX-015, days 1-5 every month administered intratumorally under radiographic guidance, in combination with MAP (mitomycin-C, doxorubicin, cisplatin) chemotherapy in patients with advanced sarcoma. Six patients were treated. Injected lesions included liver metastases in four patients and chest wall metastases in two patients. Sarcoma histologies were gastrointestinal stromal tumors (GIST, two patients), leiomyosarcoma (two patients), liposarcoma (one patient), and malignant peripheral nerve sheath tumor (1 patient). Dose escalation was performed from 10(9) plaque forming units (PFU)/dose (total dose of 5 x 10(9) PFU/cycle) to 10(10) PFU/dose (total dose of 5 x 10(10) PFU/cycle) without dose-limiting toxicity being encountered. Immunohistochemistry of the metastatic lesions prior to treatment showed that five out of six patients were positive for p53, while two patients also had mdm-2 overexpression. Adenoviral replication was detected in two out of six patient biopsies on day 5 of the first cycle, by in situ hybridization (ISH). Both patients were treated at the highest dose level. ONYX-015 viral DNA was detected by quantitative PCR in the plasma of 5/6 patients on day 5 of the first cycle, and up to day 12 (7 days after the last viral dose) in one patient who had extended sampling for viral kinetics performed, suggesting viral replication in sarcoma tissue. One patient with p53 mutation and MDM-2 amplification achieved a partial response to treatment that lasted 11 months. In conclusion, intratumoral administration of ONYX-015 in combination with MAP chemotherapy is well tolerated with no significant toxicity due to ONYX-015 being encountered. Detection of viral DNA in post treatment tumor specimens by ISH and detection of the ONYX-015 genome in the peripheral blood by quantitative PCR, up to 7 days after the last viral dose provide evidence for adenoviral replication. There was evidence of antitumor activity in one out of six patients. Further investigation of this approach in patients with recurrent sarcomas is warranted.

Truncated N-terminal mutants of SV40 large T antigen as minimal immortalizing agents for CNS cells

Immortalized central nervous system (CNS) cell lines are useful as in vitro models for innumerable purposes such as elucidating biochemical pathways, studies of effects of drugs, and ultimately, such cells may also be useful for neural transplantation. The SV40 large T (LT) oncoprotein, commonly used for immortalization, interacts with several cell cycle regulatory factors, including binding and inactivating p53 and retinoblastoma family cell-cycle regulators. In an attempt to define the minimal requirements of SV40 T antigen for immortalizing cells of CNS origin, we constructed T155c, encoding the N-terminal 155 amino acids of LT. The p53 binding region is known to reside in the C-terminal region of LT. An additional series of mutants was produced to further narrow the molecular targets for immortalization, and plasmid vectors were constructed for each. In a p53 temperature sensitive cell line model, T64-7B, expression of T155c and all constructs having mutations outside of the first 82 amino acids were capable of overriding cell-cycle block at the non-permissive growth temperature. Several cell lines were produced from fetal rat mesencephalic and cerebral cortical cultures using the T155c construct. The E107K construct contained a mutation in the Rb binding region, but was nonetheless capable of overcoming cell cycle block in T64-7B cell and immortalizing primary cultured cells. Cells immortalized with T155c were often highly dependent on the presence of bFGF for growth. Telomerase activity, telomere length, growth rates, and integrity of the p53 gene in cells immortalized with T155c did not change over 100 population doublings in culture, indicating that cells immortalized with T155c were generally stable during long periods of continuous culture.

Operative Strategies in Aortic Graft Infections: Is Complete Graft Excision Always Necessary?

The classic approach to aortic graft infections involves complete excision of the graft material with remote reconstruction of the distal circulation. Certain patients may not be well suited for this approach for physiologic or anatomic reasons. This study was undertaken to determine the outcome of partial graft excision in selected patients with aortic graft infection who were not felt to be candidates for complete graft excision. Retrospective analysis of 30 consecutive patients treated with infected grafts arising from the aorta over the past 10 years was performed. Mean interval between graft placement and infection was 5.5 years. Complete graft excision with bypass via clean tissue planes was achieved in 15 patients (group A), and partial or complete graft salvage or in situ graft replacement was performed at the discretion of the surgeon in 15 patients (group B). Perioperative mortality occurred in eight subjects (27%), including six in group A (40%) and two in group B (13%; p = NS). Six patients (20%) developed recurrent infection following graft excision, two (13%) in group A and four (27%) in group B (p = NS). Microorganisms were recovered from 24 of 30 (80%) graft cultures: 13 (43%) were gram positive, 4 (13%) were gram negative, and both gram-positive and gram-negative organisms were recovered from 7 (23%). Identification of culture isolates did not influence either perioperative mortality or the development of recurrent infection. Long-term survival was no different between the groups. We conclude that in certain high-risk patients who may not tolerate complete graft excision, local resection of infected graft segments may be preferable and leads to similar short- and long-term outcome.

Surface analysis and depth profiling of corrosion products formed in lead pipes used to supply low alkalinity drinking water

Modern analytical techniques have been applied to investigate the nature of lead pipe corrosion products formed in pH adjusted, orthophosphate-treated, low alkalinity water, under supply conditions. Depth profiling and surface analysis have been carried out on pipe samples obtained from the water distribution system in Glasgow, Scotland, UK. X-ray diffraction spectrometry identified basic lead carbonate, lead oxide and lead phosphate as the principal components. Scanning electron microscopy/energy-dispersive x-ray spectrometry revealed the crystalline structure within the corrosion product and also showed spatial correlations existed between calcium, iron, lead, oxygen and phosphorus. Elemental profiling, conducted by means of secondary ion mass spectrometry (SIMS) and secondary neutrals mass spectrometry (SNMS) indicated that the corrosion product was not uniform with depth. However, no clear stratification was apparent. Indeed, counts obtained for carbonate, phosphate and oxide were well correlated within the depth range probed by SIMS. SNMS showed relationships existed between carbon, calcium, iron, and phosphorus within the bulk of the scale, as well as at the surface. SIMS imaging confirmed the relationship between calcium and lead and suggested there might also be an association between chloride and phosphorus.

Imaging-guided radiofrequency ablation of solid renal tumors

OBJECTIVE

We performed a retrospective review of imaging-guided radiofrequency ablation of solid renal tumors.

MATERIALS AND METHODS

Since May 2000, 35 tumors in 20 patients have been treated with radiofrequency ablation. The size range of treated tumors was 0.9-3.6 cm (mean, 1.7 cm). Reasons for patient referrals were a prior partial or total nephrectomy (nine patients), a comorbidity excluding nephrectomy or partial nephrectomy (10 patients), or a treatment alterative to nephron-sparing surgery (one patient who refused surgery). Tumors were classified as exophytic, intraparenchymal, or central. Sixteen patients had 31 lesions that showed serial growth on CT or MR imaging. Of these 16 patients, four patients with 10 lesions had a history of renal cell carcinoma, and two patients with 11 lesions had a history of von Hippel-Lindau disease. Four patients had incidental solid masses, two of which were biopsied and shown to represent renal cell carcinoma, and the remaining two masses were presumed malignant on the basis of imaging features. Successful ablation was regarded as any lesion showing less than 10 H of contrast enhancement on CT or no qualitative evidence of enhancement after IV gadolinium contrast-enhanced MR imaging.

RESULTS

Of the 35 tumors, 22 were exophytic and 13 were intraparenchymal. Twenty-seven of the 35 were treated percutaneously using either sonography (n = 22) or CT (n = 5). Two patients had eight tumors treated intraoperatively using sonography. Patients were followed up with contrast-enhanced CT (n = 18), MR imaging (n = 5), or both (n = 5) with a follow-up range of 1-23 months (mean, 9 months). No residual or recurrent tumor and no major side effects were seen.

CONCLUSION

Preliminary results with radiofrequency ablation of exophytic and intraparenchymal renal tumors are promising. Radiofrequency ablation is not associated with significant side effects. Further follow-up is necessary to determine the long-term efficacy of radiofrequency ablation.

Ultrasound-guided biopsy and ablation in the neck

Management and therapy of conditions of the thyroid, parathyroid glands, and cervical lymph nodes have evolved rapidly during the past 15 years. The development and continued improvement of high-resolution ultrasound (US) equipment, US-guided biopsy, and image-guided ablative techniques have fueled this change. These technical improvements and the knowledge and experience gained during this time have decreased the rate of unnecessary surgery in patients with thyroid nodules. They have also allowed more limited neck dissection in patients with parathyroid adenomas and have led to the development of US-guided ablative techniques that have eliminated the need for surgery in some cases. This article reviews the rationale and techniques of US-guided biopsy of the thyroid, parathyroid, and cervical lymph nodes. Established and evolving ablative techniques of these structures are also examined.

Percutaneous ethanol injection for treatment of cervical lymph node metastases in patients with papillary thyroid carcinoma

OBJECTIVE

The objective of this study was to evaluate the technique, efficacy, and side effects of percutaneous ethanol injection in patients with limited cervical nodal metastases from papillary thyroid carcinoma.

SUBJECTS AND METHODS

Fourteen patients who had undergone thyroidectomy for papillary thyroid carcinoma presented with limited nodal metastases (one to five involved nodes) in the neck between May 1993 and April 2000. All patients had received previous iodine-131 ablative therapy with a mean total dose per patient of 7,548 MBq. Ten of the patients either were considered poor surgical candidates or preferred not to have surgery, and all were unresponsive to iodine-131 therapy. Each metastatic lymph node was treated with percutaneous ethanol injection, and patients received both clinical and sonographic follow-up.

RESULTS

Twenty-nine metastatic lymph nodes in our 14 patients were injected. Mean sonographic follow-up was 18 months (range, from 2 months to 6 years 5 months). All treated lymph nodes decreased in volume from a mean of 492 mm(3) before percutaneous ethanol injection to a mean volume of 76 mm(3) at 1 year and 20 mm(3) at 2 years after treatment. Six nodes were re-treated 2-12 months after initial percutaneous ethanol injection because of persistent flow on color Doppler sonography (n = 4), stable size (n = 1), or increased size (n = 1). Two patients developed four new metastatic nodes during the follow-up period that were amenable to percutaneous ethanol injection. Two patients developed innumerable metastatic nodes that precluded retreatment with percutaneous ethanol injection. No major complications occurred. All patients experienced long-term local control of metastatic lymph nodes treated by percutaneous ethanol injection. In 12 of 14 patients, percutaneous ethanol injection was successful in controlling all known metastatic adenopathy.

CONCLUSION

Sonographically guided percutaneous ethanol injection is a valuable treatment option for patients with limited cervical nodal metastases from papillary thyroid cancer who are not amenable to further surgical or radioiodine therapy.

Functions of AKT1 and AKT2 potassium channels determined by studies of single and double mutants of Arabidopsis

A reverse genetic strategy was used to isolate Arabidopsis plants containing "knockout" mutations in AKT1 and AKT2, two members of a K+ channel gene family. Comparative studies of growth and membrane properties in wild-type and mutant seedlings were performed to investigate the physiological functions of these two related channels. The growth rates of plants supplied with rate-limiting concentrations of K+ depended on the presence of AKT1 but not AKT2 channels. This result indicates that AKT1 but not AKT2 mediates growth-sustaining uptake of K+ into roots, consistent with the expression patterns of these two genes. K+ -induced membrane depolarizations were measured with microelectrodes to assess the contribution each channel makes to the K+ permeability of the plasma membrane in three different organs. In apical root cells, AKT1 but not AKT2 contributed to the K+ permeability of the plasma membrane. In cotyledons, AKT1 was also the principal contributor to the K+ permeability. However, in the mesophyll cells of leaves, AKT2 accounted for approximately 50% of the K+ permeability, whereas AKT1 unexpectedly accounted for the remainder. The approximately equal contributions of AKT1 and AKT2 in leaves detected by the in vivo functional assay employed here are not in agreement with previous RNA blots and promoter activity studies, which showed AKT2 expression to be much higher than AKT1 expression in leaves. This work demonstrates that comparative functional studies of specific mutants can quantify the relative contributions of particular members of a gene family, and that expression studies alone may not reliably map out distribution of gene functions.

Functions of AKT1 and AKT2 potassium channels determined by studies of single and double mutants of Arabidopsis

A reverse genetic strategy was used to isolate Arabidopsis plants containing "knockout" mutations in AKT1 and AKT2, two members of a K+ channel gene family. Comparative studies of growth and membrane properties in wild-type and mutant seedlings were performed to investigate the physiological functions of these two related channels. The growth rates of plants supplied with rate-limiting concentrations of K+ depended on the presence of AKT1 but not AKT2 channels. This result indicates that AKT1 but not AKT2 mediates growth-sustaining uptake of K+ into roots, consistent with the expression patterns of these two genes. K+ -induced membrane depolarizations were measured with microelectrodes to assess the contribution each channel makes to the K+ permeability of the plasma membrane in three different organs. In apical root cells, AKT1 but not AKT2 contributed to the K+ permeability of the plasma membrane. In cotyledons, AKT1 was also the principal contributor to the K+ permeability. However, in the mesophyll cells of leaves, AKT2 accounted for approximately 50% of the K+ permeability, whereas AKT1 unexpectedly accounted for the remainder. The approximately equal contributions of AKT1 and AKT2 in leaves detected by the in vivo functional assay employed here are not in agreement with previous RNA blots and promoter activity studies, which showed AKT2 expression to be much higher than AKT1 expression in leaves. This work demonstrates that comparative functional studies of specific mutants can quantify the relative contributions of particular members of a gene family, and that expression studies alone may not reliably map out distribution of gene functions.

Radiofrequency treatment of hepatic neoplasms in patients with permanent pacemakers

Clinicians who provide care for patients with implantable devices for rhythm management, ie, pacemakers and internal cardioverter defibrillators, must be aware of sources of interference that could affect device function. Intracardiac radiofrequency is a recognized source of potential interference. However, radiofrequency to extracardiac sites that are relatively close to the implanted device has not been investigated thoroughly. We present 2 patients with permanent pacemakers undergoing intrahepatic radiofrequency for the treatment of metastatic disease. No interference was documented in either patient. Additional in vitro and in vivo studies are needed to determine definite clinical guidelines for such patients.

Fas-induced apoptosis of glioma cells is associated with down-regulation of the hSCO1 protein, a subunit of complex IV

ApoI/Fas belongs to the tumor necrosis factor receptor (TNFR) superfamily and mediates cell death in various cell types. Earlier studies from this laboratory have shown that Fas-mediated cell death of glioma cells occur, in part, through the production of reactive oxygen species (ROS). To further dissect the molecular mechanisms that are involved in Fas-induced cell death, we compared gene expression between Fas-treated and saline-treated human neuroglioma H4 cells by using the technique of mRNA differential display. This approach led to the identification of hSCO1, a component of the inner mitochondrial membrane, which is required for the correct assembly, and catalytic function of cytochrome-c oxidase, as a Fas down-regulated gene. The decrease in hSCO1 mRNA expression was time-dependent, becoming most prominent after 4 h of Fas-treatment. Morphological changes observed by confocal microscopy revealed that after 4 h of Fas-treatment, the cells undergo membrane blebbing and early formation of apoptotic bodies. These observations are discussed in terms of their support for an important role of mitochondrial events in Fas-induced apoptosis.

Intraoperative duplex ultrasound during carotid endarterectomy

The purpose of this study was to examine the technical aspects of intraoperative duplex ultrasound (DUS) following carotid endarterectomy (CEA), suggest criteria to differentiate significant lesions requiring immediate surgical revision from normal or benign defects, and evaluate how frequently intraoperative DUS provides useful or unsuspected information. A retrospective study was performed on all patients who had both CEA and intraoperative carotid DUS between January 1, 1990, and January 1, 1995. A total of 155 DUS examinations were performed in 149 patients. Findings were grouped into three categories: normal; minor/insignificant lesions; and hemodynamically significant lesions based on the presence or absence of elevated peak systolic velocities, visible stenosis/thrombus, or intimal flap/dissection. Postoperative status was correlated with intraoperative DUS findings. Ninety-one (59%) examinations performed on 87 patients produced normal findings. Forty-seven (30%) examinations performed on 45 patients showed minor abnormalities consisting of insignificant residual plaque, residual external carotid artery stenoses, small intimal flaps, elevated velocities with no associated anatomic lesion, or an arterial kink. Fourteen patients (9%) had significant findings requiring immediate surgical revision. These consisted of large intimal flaps or dissection in six patients, marked residual plaque and significant stenosis in five patients, thrombus in two patients, and a kink in one patient. Three additional patients (2%) had significant findings but were not revised for various reasons. No significant difference was identified in morbidity or mortality rates between those patients with normal findings, those patients with minor technical defects, and those patients with significant abnormalities undergoing immediate surgical revision. However, two of three patients who had significant abnormalities within the common carotid artery that were not revised suffered perioperative ipsilateral strokes. Intraoperative DUS is a safe and accurate method to assess the technical adequacy of CEA. Intraoperative DUS showed significant lesions in 11% of patients. Identification and immediate repair of significant technical defects may decrease perioperative complication rate and long-term restenosis rate.

Screening of five drugs for efficacy against Babesia felis in experimentally infected cats

The efficacy of 5 drugs was tested against experimental Babesia felis infection in domestic cats. Two of the drugs, rifampicin and a sulphadiazine-trimethoprim combination, appeared to have an anti-parasitic effect, but were inferior to primaquine. The other 3 drugs, buparvaquone, enrofloxacin and danofloxacin, had no significant anti-babesial effect.

Reliability of water proton chemical shift temperature calibration for focused ultrasound ablation therapy

Our purpose in this work was to assess the reliability of the calibration coefficient for magnetic resonance water proton chemical shift temperature mapping. Over a six month period, the calibration coefficient was measured 15 times in several different phantoms. A highly linear relationship between water proton chemical shift and temperature change was found. The average temperature calibration coefficient determined from all studies was 0.009+/-0.001 ppm/degrees C. Four of the 15 studies were conducted on the same day using the same phantom. The average temperature calibration coefficient of these four studies was 0.0096+/-0.0001 ppm/degrees C.

Immunotherapy of advanced malignancy by direct gene transfer of an interleukin-2 DNA/DMRIE/DOPE lipid complex: phase I/II experience

PURPOSE

We have completed a phase I study, followed by three phase I/II studies, in patients with metastatic melanoma, renal cell carcinoma (RCC), and sarcoma in order to evaluate the safety, toxicity, and antitumor activity of Leuvectin (Vical Inc, San Diego, CA), a gene transfer product containing a plasmid encoding human interleukin (IL)-2 formulated with the cationic lipid 1, 2-dimyristyloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide/dioleyl-phosphatidyl-ethanolamine (DMRIE/DOPE) and administered intratumorally.

PATIENTS AND METHODS

Twenty-four patients were treated in the phase I study. Leuvectin doses were 10 microg, 30 microg, or 300 microg weekly for 6 weeks. In three subsequent phase I/II studies, a total of 52 patients (18 with melanoma, 17 with RCC, and 17 with sarcoma) were treated with further escalating doses of Leuvectin: 300 microg twice a week for 3 weeks, 750 microg weekly for 6 weeks, and 1,500 microg weekly for 6 weeks.

RESULTS

There were no drug-related grade 4 toxicities and only one grade 3 toxicity, but the majority of patients experienced mild constitutional symptoms after treatment. In the phase I/II studies, 45 patients were assessable for response (14 with RCC, 16 with melanoma, and 15 with sarcoma). Two patients with RCC and one with melanoma have achieved partial responses lasting from 16 to 19 months and continuing. In addition, two RCC, three melanoma, and six sarcoma patients had stable disease lasting from 3 to 18 months and continuing. The plasmid was detected by polymerase chain reaction assay in the posttreatment samples of 29 of 46 evaluated patients. Immunohistochemistry studies on serial biopsy specimens showed increased IL-2 expression and CD8(+) infiltration after treatment in the tumor samples of several patients (12 and 16, respectively).

CONCLUSION

Direct intratumoral injection of Leuvectin is a safe and possibly effective immunotherapeutic approach in the treatment of certain tumor types.

Could treatment of pregnant mares prevent abortions due to equine piroplasmosis?

Treatment of pregnant mares to prevent abortions due to equine piroplasmosis is a novel idea practised empirically at some Thoroughbred studs in South Africa. This paper presents the results of an investigation to ascertain whether imidocarb dipropionate crosses the equine placenta. Three pregnant mares were injected intramuscularly with imidocarb and their foetuses were mechanically aborted at varying time intervals thereafter. Imidocarb was found in foetal blood at a level similar to that in the dam's blood, suggesting that imidocarb administered to the dam would be available for anti-parasitic activity in the foetal circulation. Uncertainty concerning the time of treatment to achieve the desired effect currently makes this a questionable exercise.

Potassium uptake supporting plant growth in the absence of AKT1 channel activity: Inhibition by ammonium and stimulation by sodium

A transferred-DNA insertion mutant of Arabidopsis that lacks AKT1 inward-rectifying K+ channel activity in root cells was obtained previously by a reverse-genetic strategy, enabling a dissection of the K+-uptake apparatus of the root into AKT1 and non-AKT1 components. Membrane potential measurements in root cells demonstrated that the AKT1 component of the wild-type K+ permeability was between 55 and 63% when external [K+] was between 10 and 1,000 microM, and NH4+ was absent. NH4+ specifically inhibited the non-AKT1 component, apparently by competing for K+ binding sites on the transporter(s). This inhibition by NH4+ had significant consequences for akt1 plants: K+ permeability, 86Rb+ fluxes into roots, seed germination, and seedling growth rate of the mutant were each similarly inhibited by NH4+. Wild-type plants were much more resistant to NH4+. Thus, AKT1 channels conduct the K+ influx necessary for the growth of Arabidopsis embryos and seedlings in conditions that block the non-AKT1 mechanism. In contrast to the effects of NH4+, Na+ and H+ significantly stimulated the non-AKT1 portion of the K+ permeability. Stimulation of akt1 growth rate by Na+, a predicted consequence of the previous result, was observed when external [K+] was 10 microM. Collectively, these results indicate that the AKT1 channel is an important component of the K+ uptake apparatus supporting growth, even in the "high-affinity" range of K+ concentrations. In the absence of AKT1 channel activity, an NH4+-sensitive, Na+/H+-stimulated mechanism can suffice.

A possible new piroplasm in lions from the Republic of South Africa

A small piroplasm was detected in blood smears from lions (Panthera leo) in the Kruger National Park (KNP; Republic of South Africa) during 1991/1992. The parasite was identified provisionally as Babesia felis, but sera from these lions tested negative to B. felis antigen in the indirect immunofluorescent antibody test (IFAT). Blood from an infected lion was subsequently subinoculated into a domestic cat and two leopards in an attempt to identify the parasite. A lion also was infected with B. felis (from a cat). Serum samples collected from these animals were tested against B. felis, the KNP small piroplasm, and Cytauxzoon felis antigen in the IFAT. The serological results indicate that the KNP small piroplasm isolated from the lion is probably a distinct species from B. felis and C. felis.

MR-guided focused-ultrasound ablation system: determination of precision and accuracy in preparation for clinical trials

The authors analyzed the accuracy and precision of focal-spot placement with a magnetic resonance-guided, focused-ultrasound system. Average absolute accuracy errors ranged from 0.2 to 1.0 mm, and average absolute individual precision errors ranged from 0.2 to 0.3 mm. To prevent damage to vital structures, single sonications and sonication grids should be placed beyond approximately 2 and 1 mm, respectively.

Ultrasound appearance of synovial osteochondromatosis of the shoulder

This case report demonstrates the ultrasound appearance of synovial osteochondromatosis of the shoulder, along with plain film radiographic, computed tomographic, and pathologic correlation. Because of recent renewed interest in the use of ultrasonography in the evaluation of musculoskeletal disease, such as rotator cuff arthropathy or suspected intra-articular loose body, opportunities to diagnose synovial osteochondromatosis with this modality have become more frequent.

Factors affecting clinical outcome following endoscopic perforator vein ablation

BACKGROUND

Despite good outcomes reported with minimally invasive, subfascial endoscopic perforator surgery (SEPS), some patients demonstrate poor healing or recurrence of venous ulcers. The goal of this study was to identify factors that lead to failure of SEPS.

METHODS

Forty-eight consecutive patients who had undergone 57 SEPS procedures were analyzed. Mean follow-up was 17 +/- 2 months (range 2 weeks to 52 months).

RESULTS

All active ulcers (n = 22) at the time of surgery healed in an average of 99 +/- 37 days (range 11 to 670). Eight limbs had poor healing of their ulcer (>40 days); five (9%) new/recurrent ulcers developed postoperatively. Deep venous obstruction was associated with delayed ulcer healing (316 +/- 171 versus 51 +/- 14 days, P < 0.01) and ulcer recurrence (P < 0.0001). Poor ulcer healing and recurrence were not associated with lipodermatosclerosis, edema, ulcer duration >3 months, or previous recurrences. Ulcer size >2 cm (P < 0.05) and combined ilio-femoral and popliteal/tibial reflux were associated with poor ulcer healing (P < 0.05).

CONCLUSIONS

SEPS could not prevent recurrent or new ulceration in 9% of limbs. Venous outflow obstruction was associated with ulcer recurrence and prolonged ulcer healing. Multilevel deep venous reflux and ulcer size >2 cm were also associated with delayed healing.

A role for the AKT1 potassium channel in plant nutrition

In plants, potassium serves an essential role as an osmoticum and charge carrier. Its uptake by roots occurs by poorly defined mechanisms. To determine the role of potassium channels in planta, we performed a reverse genetic screen and identified an Arabidopsis thaliana mutant in which the AKT1 channel gene was disrupted. Roots of this mutant lacked inward-rectifying potassium channels and displayed reduced potassium (rubidium-86) uptake. Compared with wild type, mutant plants grew poorly on media with a potassium concentration of 100 micromolar or less. These results and membrane potential measurements suggest that the AKT1 channel mediates potassium uptake from solutions that contain as little as 10 micromolar potassium.

Nonselective block by La3+ of Arabidopsis ion channels involved in signal transduction

Lanthanide ions such as La3+ are frequently used as blockers to test the involvement of calcium channels in plant and animal signal transduction pathways. For example, the large rise in cytoplasmic Ca2+ concentration triggered by cold shock in Arabidopsis seedlings is effectively blocked by 10 mM La3+ and we show here that the simultaneous large membrane depolarization is similarly blocked. However, a pharmacological tool is only as useful as it is selective and the specificity of La3+ for calcium channels was brought into question by our finding that it also blocked a blue light (BL)-induced depolarization that results from anion channel activation and believed not to involve calcium channels. This unexpected inhibitory effect of La3+ on the BL-induced depolarization is explained by our finding that 10 mM La3+ directly and completely blocked the BL-activated anion channel when applied to excised patches. We have investigated the ability of La3+ to block noncalcium channels in Arabidopsis. In addition to the BL-activated anion channel, 10 mM La3+ blocked a cation channel and a stretch-activated channel in patches of plasma membrane excised from hypocotyl cells. In root cells, 10 mM La3+ inhibited the activity of an outward-rectifying potassium channel at the whole cell and single-channel level by 47% and 58%, respectively. We conclude that La3+ is a nonspecific blocker of multiple ionic conductances in Arabidopsis and may disrupt signal transduction processes independently of any effect on Ca2+ channels.

MR angiographic and sonographic indications for endarterectomy

PURPOSE

Our objective was to determine whether appropriate criteria could be developed for performing an endarterectomy on the basis of sonographic and MR angiographic findings.

METHODS

Fifty patients were examined prospectively with sonography, MR angiography, and conventional angiography. All three imaging studies were performed within 2 weeks of one another, and conventional angiography served as the reference standard.

RESULTS

All 10 carotid occlusions were detected with sonography and MR angiography. Sonography accurately showed flow in two arteries, and MR angiography showed flow in one of three nearly occluded arteries with extremely slow flow. Multislab three-dimensional time-of-flight MR angiographic sequences underestimated the degree of stenosis in 12 arteries, and in two cases this resulted from high T1 signal within the atherosclerotic plaque. With conventional angiography as the reference standard for 70% to 99% stenosis, sonography had a sensitivity of 96%, a specificity of 91%, and a positive predictive value of 90%, while concordant sonographic findings and the presence of a signal void on multislab 3-D time-of-flight sequences had a sensitivity of 72%, a specificity of 98%, and a positive predictive value of 97%.

CONCLUSION

Endarterectomy performed on the basis of sonographic findings of 70% to 99% stenosis and of a signal void on multislab 3-D time-of-flight MR angiographic sequences is appropriate.

Ca(2+)-activated anion channels and membrane depolarizations induced by blue light and cold in Arabidopsis seedlings

The activation of an anion channel in the plasma membrane of Arabidopsis thaliana hypocotyls by blue light (BL) is believed to be a signal-transducing event leading to growth inhibition. Here we report that the open probability of this particular anion channel depends on cytoplasmic Ca2+ ([Ca2+]cyt) within the concentration range of 1 to 10 microM, raising the possibility that BL activates the anion channel by increasing [Ca2+]cyt. Arabidopsis seedlings cytoplasmically expressing aequorin were generated to test this possibility. Aequorin luminescence did not increase during or after BL, providing evidence that Ca2+ does not play a second-messenger role in the activation of anion channels. However, cold shock simultaneously triggered a large increase in [Ca2+]cyt and a 110-mV transient depolarization of the plasma membrane. A blocker of the anion channel, 5-nitro-2-(3-phenylpropylamino)-benzoic acid, blocked 61% of the cold-induced depolarization without affecting the increase in [Ca2+]cyt. These data led us to propose that cold shock opens Ca2+ channels at the plasma membrane, allowing an inward, depolarizing Ca2+ current. The resulting large increase in [Ca2+]cyt activates the anion channel, which further depolarizes the membrane. Although an increase in [Ca2+]cyt may activate anion channels in response to cold, it appears that BL does so via a Ca(2+)-independent pathway.

Phase I study of immunotherapy of hepatic metastases of colorectal carcinoma by direct gene transfer of an allogeneic histocompatibility antigen, HLA-B7

We have completed a phase I study to test feasibility and toxicity of immunotherapy of hepatic metastases from colorectal carcinoma by direct gene transfer of HLA-B7, a MHC class I gene. Eligible patients were HLA-B7 negative, immunocompetent by PHA lymphocyte stimulation and had at least two measurable hepatic lesions on CT scan for measurement of response of the injected lesion, as well as evaluation of possible distant response. Under ultrasonographic guidance the hepatic lesions were injected with Allovectin-7, a liposomal vector containing the combination of the HLA-B7 gene with beta 2-microglobulin formulated with the lipid DMRIE-DOPE. Eligible patients were injected on two schedules. On the first schedule patients received an injection on day 1 and the injected lesion was biopsied to determine transfection every 2 weeks for 8 weeks. Doses were escalated from 10 micrograms to 50 micrograms to 250 micrograms with three patients treated at each level. The second schedule included multiple injections of 10 micrograms. Three patients received injections on days 1 and 15. Three patients received injections on days 1, 15 and 29. A total of 15 patients have completed treatment. The plasmid DNA was detected in 14 of 15 patients (93%) by PCR. In five of 15 patients (33%) mRNA was also detected. The HLA-B7 protein was detected in five of eight patients (63%) by immunohistochemistry and in seven of 14 patients (50%) tested by fluorescence activated cell sorting (FACS) analysis. There has been no serious toxicity directly attributable to allovectin-7. Our results suggest that liposomal gene transfer by direct injection is feasible and non-toxic. Further studies will be necessary in order to establish the therapeutic efficacy.

Intraoperative color-flow duplex ultrasonography following carotid endarterectomy

Intraoperative color-flow duplex ultrasonography represents the state-of-the-art imaging following carotid endarterectomy. At a reasonable cost and at no risk to the patient, it provides a high-resolution image of the operative site and reproducible hemodynamic velocity measurements. Although significant technical abnormalities have been noted in approximately 10% of patients, important lesions are found in only 5% of common or internal carotid arteries. In our opinion, these common and internal carotid artery defects represent the lesions that should be re-explored and corrected prior to leaving the operating room. The most cost-effective way to utilize intraoperative color-flow duplex ultrasonography is to arrange a 15- to 20-minute visit to the operating room by a technologist bringing a duplex scanner from the vascular laboratory or department of radiology. If the surgeon is not experienced in performing duplex ultrasonography, the test should be performed in conjunction with another physician, surgeon, or radiologist who specializes in ultrasound. In our experience, color-flow duplex ultrasonography enhances endarterectomy technique and consequently minimizes postoperative strokes and restenosis.

Isolation of a South African vector-specific strain of Babesia canis

A South African strain of Babesia canis parasites was isolated and shown to be vector-specific to only one of the two vectors in the region, Haemaphysalis leachi. This tick was found to transmit the parasite in its adult instar. When infected as larvae, the ticks would not transmit in the proceeding nymphal instar. The vector-specific strain was named the 'Thomas strain' after one of the dogs involved in isolating it. A survey revealed a prevalence of > 50% of this strain in four widely separated areas of the country. Rhipicephalus sanguineus, which transmits B. canis vogeli elsewhere, has not been shown to be a vector of the South African strain of B. canis.

Sterilisation of Babesia canis infections by imidocarb alone or in combination with diminazene

Babesia canis infections were apparently sterilised by a single dose of imidocarb at 7.5 mg kg-1, as well as by a single dose of diminazene at 3.5 mg kg-1, followed by a single dose of imidocarb at 6 mg kg-1 the following day. This was confirmed by subinoculation of blood from these dogs to splenectomised recipients. Sterilisation of the infection is not recommended in endemic areas; a more rational approach would be to allow a state of premunity to develop in dogs at risk to repeated infections.

Immune responses to South African Babesia canis and the development of a preliminary vaccine

The immune responses of 2 Beagles to live parasites of an isolated B. canis strain were tested. The dogs were infected with live parasites and were carefully treated to allow the parasites to remain in the dogs' bodies for long enough to evoke an immune response. Once recovered from the initial infections, both dogs received 2 separate homologous challenges with live parasites. During the second challenge, neither dog showed clinical signs of disease. An experimental vaccine was developed against the isolated B. canis strain by growing parasites in a micro-aerophilous stationary phase cell culture system to provide (a) antigen-containing supernatant material and (b) pellet material containing dead parasites. Two dogs each were inoculated with the different formulations of the vaccine on 2 separate occasions. Three weeks after the second inoculation, all 4 dogs were challenged with live parasites. Three of the 4 dogs recovered from the challenge without any anti-babesial treatment.

Diagnosis of acute deep venous thrombosis of the lower extremities: prospective evaluation of color Doppler flow imaging versus venography

PURPOSE

To determine the value of color Doppler flow imaging in identification of deep venous thrombosis (DVT) of the femoropopliteal system without use of venous compression.

MATERIALS AND METHODS

Color Doppler flow imaging was compared with venography in 103 lower extremities in 101 patients. Results of each examination were recorded as positive or negative for acute DVT or consistent with chronic DVT.

RESULTS

Color Doppler flow imaging in 97 of 103 cases had a sensitivity of 95%, specificity of 99%, positive and negative predictive values of 95% and 99%, respectively, and accuracy of 98% in detection of acute DVT and was also helpful in differentiation of chronic from acute DVT. Color Doppler flow imaging prospectively identified six of eight patients with chronic DVT and correctly identified acute DVT in two patients with underlying chronic DVT. No results were false-positive for acute DVT in a patient with chronic DVT.

CONCLUSION

Color Doppler flow imaging is complementary to compression ultrasonography in evaluation of suspected acute DVT and may be helpful in evaluation of suspected DVT in patients with previous or chronic DVT.

Neonatal screening for cystic fibrosis using immunoreactive trypsinogen and direct gene analysis: four years' experience

OBJECTIVE

To assess the performance and impact of a two tier neonatal screening programme for cystic fibrosis based on an initial estimation of immunoreactive trypsinogen followed by direct gene analysis.

DESIGN

Four year prospective study of two tier screening strategy. First tier: immunoreactive trypsinogen measured in dried blood spot samples from neonates aged 3-5 days. Second tier: direct gene analysis of cystic fibrosis mutations (delta F508, delta I506, G551D, G542X, and R553X) in samples with immunoreactive trypsinogen concentrations in highest 1% and in all neonates with meconium ileus or family history of cystic fibrosis.

SETTING

South Australian Neonatal Screening Programme, Adelaide.

SUBJECTS

All 88,752 neonates born in South Australia between December 1989 and December 1993.

INTERVENTIONS

Neonates with two identifiable mutations were referred directly for clinical assessment and confirmatory sweat test; infants with only one identifiable mutation were recalled for sweat test at age 3-4 weeks. Parents of neonates identified as carriers of cystic fibrosis mutation were counselled and offered genetic testing.

MAIN OUTCOME MEASURES

Identification of all children with cystic fibrosis in the screened population.

RESULTS

Of 1004 (1.13%) neonates with immunoreactive trypsinogen > or = 99th centile, 912 (90.8%) had no identifiable mutation. 23 neonates were homozygotes or compound heterozygotes; 69 carried one identifiable mutation, of whom six had positive sweat tests. Median age at clinical assessment for the 29 neonates with cystic fibrosis was 3 weeks; six had meconium ileus and two had affected siblings. 63 neonates were identified as carriers of a cystic fibrosis mutation. Extra laboratory costs for measuring immunoreactive trypsinogen and direct gene analysis were $A1.50 per neonate screened.

CONCLUSION

This strategy results in early and accurate diagnosis of cystic fibrosis and performs better than screening strategies based on immunoreactive trypsinogen measurement alone.

Mutation analysis of 28 Gaucher disease patients: the Australasian experience

Gaucher disease is the most common lysosomal storage disease. It is an autosomal recessive disorder that results from a deficiency of beta-glucocerebrosidase. Three clinical phenotypes have been described: non-neuronopathic, acute neuronopathic, and subacute neuronopathic. Genomic DNA from 28 Australasian patients of diverse ethnic origin with Gaucher disease was screened for 3 common mutations (1226G, 1448C and 84GG) using the amplification refractory mutation system (ARMS), and one uncommon mutation (1504T) by restriction enzyme digestion. Thirty-eight of the 56 independent alleles in these patients were characterized, with 1448C present in 42% and 1226G in 28% of the alleles. The 1226G mutation was associated only with the non-neuronopathic phenotype and 7 of the 15 patients who carried the 1448C mutation developed neuronopathic disease. Three infants who died in the neonatal period following a rapidly progressive neurodegenerative course carried no identifiable mutations. The 84GG mutation was carried by 2 Jewish patients and 1504T was present in one patient. It is now possible to rapidly identify the common Gaucher mutations using ARMS and restriction enzyme digestion, and our findings confirm the heterogeneity of mutations in Gaucher disease. It is also possible to predict in part the phenotypic outcome when screening patients for these mutations. We consider mutation analysis to be of most use in prenatal diagnosis and for carrier detection within affected families.

Carotid artery: prospective blinded comparison of two-dimensional time-of-flight MR angiography with conventional angiography and duplex US

A prospective blinded comparison of two-dimensional (2D) time-of-flight (TF) magnetic resonance (MR) angiography and color duplex flow ultrasound (US) with conventional angiography as a standard of reference was performed in 50 patients with hemispheric ischemic symptoms. The guidelines of the North American Symptomatic Carotid Endarterectomy Trial for measuring stenosis of the internal carotid artery were utilized for maximum-intensity-projection (MIP) images and conventional angiograms. While the 2D TF MIP technique overrepresented the degree of stenosis in the internal carotid arteries, it matched the performance of color duplex flow US as measured by means of receiver operating characteristic curves. A signal void on the MIP images corresponded to a 70% or greater internal carotid artery stenosis in 17 of 20 arteries. At its current state of development, the accuracy of 2D TF MR angiography equals that of US in characterizing the degree of carotid stenosis but cannot be considered a replacement for conventional angiography.

Laboratory Evaluation of the GlucocardTM Blood Glucose Test Meter

The Glucocard (Kyoto Daiichi Kagaku) blood glucose meter is designed for self-monitoring of blood glucose concentrations in capillary blood through use of an electrochemical test strip. Evaluated in this laboratory, the Glucocard had CVs of 4.6%, 6.6%, and 3.5% at blood glucose concentrations of 2.4, 4.1, and 18.9 mmol/L, respectively. The meter's response varied linearly with blood glucose concentration between 2.2 and 27.8 mmol/L. Hemolysis, urate, ascorbate, and acetaminophen interfered by &gt; 5%. Different hematocrits, in the range 0.20-0.70, did not affect the measured glucose concentration. Comparison with glucose results measured in whole blood with a NOVA Stat Profile 5 instrument yielded the following: Glucocard = 0.898 NOVA--0.184 (r = 0.995). The main advantages of the Glucocard are its small sample volume (5 microL), wide linear range, and fully automated sample-handling steps, which reduce user-related variability.

Laboratory evaluation of the Glucocard blood glucose test meter

The Glucocard (Kyoto Daiichi Kagaku) blood glucose meter is designed for self-monitoring of blood glucose concentrations in capillary blood through use of an electrochemical test strip. Evaluated in this laboratory, the Glucocard had CVs of 4.6%, 6.6%, and 3.5% at blood glucose concentrations of 2.4, 4.1, and 18.9 mmol/L, respectively. The meter's response varied linearly with blood glucose concentration between 2.2 and 27.8 mmol/L. Hemolysis, urate, ascorbate, and acetaminophen interfered by > 5%. Different hematocrits, in the range 0.20-0.70, did not affect the measured glucose concentration. Comparison with glucose results measured in whole blood with a NOVA Stat Profile 5 instrument yielded the following: Glucocard = 0.898 NOVA--0.184 (r = 0.995). The main advantages of the Glucocard are its small sample volume (5 microL), wide linear range, and fully automated sample-handling steps, which reduce user-related variability.

Wilms' tumor: a new cause for urinary extravasation

We report a case of Wilms' tumor associated with urinary extravasation due to tumor invasion through the renal pelvis and anterior renal capsule. Extravasation of urine exposed to tumor may lead to upstaging of the tumor and the requirement for more intensive therapy.

The efficacy of ultrasonic pest controllers for fleas and ticks

Two ultrasonic pest controllers, a pet-collar unit and a large unit for household use, were tested for their efficacy in repelling fleas and ticks in a choice chamber. Neither unit had any affect on the distribution of fleas or ticks in the choice chamber up to 24 h exposure, and activity of fleas, ticks and cockroaches was unimpaired. The study extends and supports previous findings that ultrasound is ineffective as a means of controlling common pests of households and pets.

Current applications of duplex and color Doppler ultrasound imaging: carotid and peripheral vascular system

Recent advances in ultrasound technology have made possible the development of diagnostic instruments that combine cross-sectional imaging and Doppler analysis. These instruments have expanded the role of diagnostic ultrasonography to the assessment of carotid and peripheral vascular disease. The current applications of duplex Doppler and color Doppler imaging in evaluating the extracranial carotid arteries, vertebral artery, peripheral venous system, and peripheral arterial system are reviewed. The indications for and limitations of these examinations, as well as the potential future uses, are discussed.

Current applications of duplex and color Doppler ultrasound imaging: abdomen

Duplex ultrasound studies and color Doppler imaging have substantially enhanced the diagnostic capabilities of abdominal ultrasonography. The status of the flow in the major abdominal vessels is routinely obtainable along with anatomic information about the organs that they supply. The current applications of duplex and color Doppler imaging in evaluating the hepatic vascular system, hepatic transplants, aorta, splanchnic arterial system, renal artery and vein, renal transplants, and penile arterial system are reviewed. The indications for and limitations of these examinations, as well as the potential future uses, are discussed.

Current applications of color Doppler imaging in the abdomen and extremities

Recent advances in ultrasound technology have resulted in the development of diagnostic instruments that combine cross sectional imaging with spectral and color flow Doppler analysis. These instruments have expanded the role of diagnostic ultrasonography in the assessment of disease states involving the extracranial carotid artery, the peripheral vascular system, and the major abdominal vessels. The current applications of color Doppler imaging (CDI) combined with conventional spectral Doppler are demonstrated.